JP2012098386A - Toner binder and toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner binder excellent in achieving both of low temperature fixability and hot offset resistance (namely a sufficient fixing temperature range) and excellent in storage stability.SOLUTION: The toner binder contains a polyester resin composition (H) which comprises: a polyester resin (A) comprising a nonlinear polyester resin (A1) having a monomer having a valence of 3 or more in a structural unit, and if necessary, a linear polyester resin (A2); and an inorganic filler (F) having an average particle diameter of 0.001 to 1.5 μm. In the resin composition, a difference in thermal conductivity between the polyester resin (A) and the inorganic filler (F) at 20°C is 25 to 350 W/m K, and the inorganic filler (F) is dispersed in the polyester resin (A).

Description

  The present invention relates to a toner binder and a toner.

  The toner binder for electrophotography, which is commonly used as an image fixing method in copying machines, printers, etc., does not fuse the toner to the heat roll even at a high fixing temperature (hot offset resistance), fixing. Toners can be fixed even at low temperatures (low temperature fixability) and storage stability is required.

  As the colorization / fixing process speeds up, a toner binder having both low-temperature fixability and hot offset resistance is required. Two molecular weights, a high-elasticity type resin effective in hot offset resistance and a low-viscosity type resin effective in low-temperature fixability, aiming to improve both low-temperature fixability and hot offset resistance Techniques for mixing toner binder resins having different distributions have been proposed (Patent Documents 1 and 2).

  As a toner excellent in balance between hot offset resistance and low-temperature fixability, a toner containing two kinds of polyester resins having different glass transition temperatures as a toner binder is disclosed (Patent Document 3).

  However, although the toner proposed in the above-mentioned patent document is excellent in the balance between hot offset resistance and low temperature fixability to some extent, in terms of both hot offset resistance and low temperature fixability at higher speed and energy saving. There is a need to improve.

JP-A-11-327210 JP 2001-356527 A Japanese Patent Laid-Open No. 2005-221986

  An object of the present invention is to provide a toner binder and a toner excellent in both low-temperature fixability and hot offset resistance (fixing temperature range) and excellent storage stability.

As a result of intensive studies to solve these problems, the present inventor has reached the present invention.
That is, the present invention provides a polyester resin (A) composed of a non-linear polyester resin (A1) containing a trivalent or higher monomer in the structural unit and, if necessary, a linear polyester resin (A2), and an average particle size of 0.1. 001-1.5 μm inorganic filler (F), the difference in thermal conductivity at 20 ° C. between the polyester resin (A) and the inorganic filler (F) is 25 to 350 W / m · K, and the polyester resin (A A toner binder containing a polyester resin composition (H) in which an inorganic filler (F) is dispersed; and a toner binder and a colorant, and if necessary, a release agent, a charge control agent, and a fluidizing agent. A toner containing one or more selected additives.

  The toner for electrophotography using the toner binder of the present invention has an excellent balance between low-temperature fixability and hot offset resistance (fixing temperature range) and excellent storage stability. In addition, a stable image density can be obtained.

The present invention is described in detail below.
The polyester resin (A) in the present invention is obtained, for example, by polycondensation of one or more types of polyol component (x) and one or more types of polycarboxylic acid component (y). As the polyol component (x), Examples include diol (x1) and / or polyol (x2) having 3 to 8 or more valences. Examples of the polycarboxylic acid component (y) include a dicarboxylic acid (y1) and / or a polycarboxylic acid (y2) having 3 to 6 or more valences.

  Examples of the diol (x1) include alkylene glycols having 2 to 36 carbon atoms (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, and 1,6-hexane. Diol etc.); C4-C36 alkylene ether glycol (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol etc.); C6-C36 alicyclic diol ( 1,4-cyclohexanedimethanol and hydrogenated bisphenol A, etc.) (poly) oxyalkylene of the above alicyclic diol (alkylene group having 2 to 4 carbon atoms, the same applies to the following polyoxyalkylene groups) ether [o Polyalkylenes of cycloalkylene units (hereinafter abbreviated as AO units) 1 to 30]; and dihydric phenols [monocyclic dihydric phenols (eg, hydroquinone) and bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.)] Examples include alkylene ethers (number of AO units 2 to 30).

  Among these (x1), preferred are alkylene glycols having 2 to 12 carbon atoms, polyoxyalkylene ethers of bisphenols (2 to 30 AO units), and combinations thereof. More preferred are polyoxyalkylene ethers of bisphenols (particularly bisphenol A) (2 and / or 3 carbon atoms of the alkylene group, 2 to 8 AO units), alkylene glycols of 2 to 12 carbon atoms (particularly ethylene glycol). , 1,2-propylene glycol), and combinations thereof (weight ratio 100: 0 to 20:80).

  Examples of the trivalent to octavalent or higher polyol (x2) include trihydric to octavalent or higher aliphatic polyhydric alcohols having 3 to 36 carbon atoms (alkane polyol and intramolecular or intermolecular dehydrates such as Glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, polyglycerin, and dipentaerythritol; sugars and derivatives thereof such as sucrose and methylglucoside); (poly) oxyalkylenes of the above aliphatic polyhydric alcohols Ether (number of AO units 1-30); polyoxyalkylene ether of trisphenols (trisphenol PA, etc.) (number of AO units 2-30); novolak resin (phenol novolak, cresol novolac, etc.) average degree of polymerization 3 60) Etc. (the number 2 to 30 of AO units) polyoxyalkylene ether.

  Among these (x2), preferred are 3 to 8 or higher aliphatic polyhydric alcohols and polyoxyalkylene ethers of novolac resins (number of AO units: 2 to 30), and particularly preferred are novolak resins. It is a polyoxyalkylene ether (number of AO units 2 to 30).

  Examples of the dicarboxylic acid (y1) include alkane dicarboxylic acids having 4 to 36 carbon atoms (for example, succinic acid, adipic acid, and sebacic acid); alicyclic dicarboxylic acids having 6 to 40 carbon atoms [for example, dimer acid (dimerized linoleic acid) )]; Alkene dicarboxylic acids having 4 to 36 carbon atoms (alkenyl succinic acid such as dodecenyl succinic acid, maleic acid, fumaric acid, citraconic acid, and mesaconic acid); aromatic dicarboxylic acids having 8 to 36 carbon atoms (phthalic acid, Isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, etc.); and ester-forming derivatives thereof (for example, anhydrides, lower alkyl (carbon number 1-4) esters (methyl esters, ethyl esters, isopropyl esters, etc.), The same applies to ester-forming derivatives]; Among these (y1), preferred are alkene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms and ester-forming derivatives thereof.

Examples of the tricarboxylic acid having a valence of 3 to 6 or more (y2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (trimellitic, pyromellitic acid, etc.), and aliphatics having 6 to 36 carbon atoms (alicyclic rings). And polycarboxylic acids (including hexanetricarboxylic acid and decanetricarboxylic acid), and ester-forming derivatives thereof.
Of these (y2), trimellitic acid and pyromellitic acid, and ester-forming derivatives thereof are preferred.

The polyester resin (A) in the present invention can be produced in the same manner as in an ordinary polyester production method. For example, the reaction can be performed in an inert gas (nitrogen gas or the like) atmosphere at a reaction temperature of preferably 150 to 280 ° C, more preferably 160 to 250 ° C, and particularly preferably 170 to 235 ° C. The reaction time is preferably 30 minutes or longer, particularly 2 to 40 hours from the viewpoint of reliably performing the polycondensation reaction. It is also effective to reduce the pressure in order to improve the reaction rate at the end of the reaction.
At this time, an esterification catalyst can be used as needed. Examples of the esterification catalyst include a tin-containing catalyst (for example, dibutyltin oxide), antimony trioxide, and a titanium-containing catalyst [for example, titanium alkoxide, potassium oxalate titanate, titanium terephthalate, a catalyst described in JP 2006-243715 A [Titanium dihydroxybis (triethanolaminate), titanium monohydroxytris (triethanolaminate), and intramolecular polycondensates thereof], and catalysts described in JP-A No. 2007-11307 (titanium tributoxyterephthalate) , Titanium triisopropoxy terephthalate, titanium diisopropoxy diterephthalate, etc.)], zirconium-containing catalysts (for example, zirconyl acetate), zinc acetate, and the like. Among these, a titanium-containing catalyst is preferable.

  The polyester resin (A) used in the present invention is composed of a non-linear polyester resin (A1) and, if necessary, a linear polyester resin (A2) from the viewpoint of achieving both low-temperature fixability and offset resistance.

  The non-linear polyester resin (A1) used in the present invention is usually a trivalent or higher monomer, that is, the above 3-6 or higher polycarboxylic acid (y2) together with the dicarboxylic acid (y1) and the diol (x1). And / or obtained by reacting a trivalent to octavalent or higher polyol (x2). The reaction ratio between the polyol component and the polycarboxylic acid component is preferably 2/1 to 1/2, more preferably 1.5 / 1 to 1/1 / as the equivalent ratio [OH] / [COOH] of the hydroxyl group to the carboxyl group. 1.3, particularly preferably 1.3 / 1 to 1 / 1.2.

  The ratio of (y2) and (x2) when obtaining (A1) is preferably such that the sum of the number of moles is the sum of the number of moles of all polyol components (x) and polycarboxylic acid components (y). Is from 0.1 to 40 mol%, more preferably from 1 to 25 mol%, particularly preferably from 3 to 20 mol%.

  The glass transition temperature [Tg] of (A1) is preferably 45 ° C to 75 ° C, more preferably 50 ° C to 70 ° C. When [Tg] is 75 ° C. or lower, the low-temperature fixability is improved. Further, when [Tg] is 45 ° C. or higher, the blocking resistance is good.

  Moreover, in the above and below, glass transition temperature [Tg] is measured by the method (DSC method) prescribed | regulated to ASTM D3418-82 using Seiko Denshi Kogyo Co., Ltd. DSC20, SSC / 580.

  The flow softening point [Tm] of (A1) is not particularly limited, but is preferably 100 ° C to 180 ° C, more preferably 120 ° C to 170 ° C. When [Tm] is 100 ° C. or higher, the hot offset resistance is good, and when it is 180 ° C. or lower, the fixability is good.

In the above and the following, the flow softening point [Tm] is a temperature at which the flow rate is raised at a constant speed under the following conditions using a flow tester, and the outflow amount becomes 1/2.
Apparatus: Flow tester CFT-500D manufactured by Shimadzu Corporation
Load: 20kg
Die: 1mmΦ-1mm
Temperature increase rate: 6 ° C./min.

The number average molecular weight (hereinafter referred to as Mn) of the tetrahydrofuran (THF) soluble part of the nonlinear polyester resin (A1) is preferably 2000 to 9500, and more preferably 2500 to 9000. When Mn is 2000 or more, the resin strength necessary for fixing is expressed, and when it is 9500 or less, the low-temperature fixing property and the resin grindability are good.
Further, the peak top molecular weight (hereinafter referred to as Mp) of the THF-soluble component of (A1) is preferably 2000 to 50000, more preferably from the viewpoint of the balance of resin strength, low-temperature fixability, and resin grindability. 2500 to 30000.

In the above and below, the Mp of the THF soluble content of the toner resin is measured under the following conditions using gel permeation chromatography (GPC).
Device (example): HLC-8120 manufactured by Tosoh Corporation
Column (example): TSK GEL GMH6 2 [Tosoh Corp.]
Measurement temperature: 40 ° C
Sample solution: 0.25% THF solution Injection volume: 100 μl
Detection apparatus: Refractive index detector Reference material: Tosoh standard polystyrene (TSK standard POLYSYRENE) 12 points (molecular weight 500 1050 2800 5970 9100 18100 37900 96400 190000 355000 1090000 2890000)
The molecular weight showing the maximum peak height on the obtained chromatogram is referred to as peak top molecular weight (Mp).
In the above and the following, “%” means “% by weight” unless otherwise specified.

The THF insoluble content in the nonlinear polyester resin (A1) is preferably 3 to 50% from the viewpoint of glossiness of the image and the dispersibility of the inorganic filler (F). More preferably, it is 5 to 40%, and particularly preferably 10 to 35%. When the THF-insoluble content is 50% or less, the glossiness (gloss) of the image and the dispersion state of the inorganic filler (F) are good.
The THF-insoluble matter in the present invention is determined by the following method.
Add 50 ml of THF to 0.5 g of the sample and stir to reflux for 3 hours. After cooling, the insoluble content is filtered off with a glass filter, and the resin content on the glass filter is dried under reduced pressure at 80 ° C. for 3 hours. The insoluble matter is calculated from the weight of the dried resin content on the glass filter and the weight ratio of the sample. In addition, this filtrate is used for GPC measurement as a THF soluble part.

The acid value of the non-linear polyester resin (A1) is preferably 10 to 70 (mg KOH / g, the same shall apply hereinafter), more preferably 13 to 60, and particularly preferably 15 to 50. When the acid value is 70 or less, the charging characteristics are good.
Further, the hydroxyl value of (A1) (mgKOH / g, the same shall apply hereinafter) is preferably 0 to 50, more preferably 0 to 45, and particularly preferably 0 to 40. When the hydroxyl value is 50 or less, the hot offset resistance becomes better.
The acid value and hydroxyl value in the present invention are measured by the method defined in JIS K0070.

  The polyester resin (A) used in the toner binder of the present invention may contain a linear polyester resin (A2) in addition to the nonlinear polyester resin (A1). When (A2) is contained, the low-temperature fixability becomes better.

  The linear polyester resin (A2) used if necessary in the present invention can be obtained, for example, by polycondensation of the diol (x1) and the dicarboxylic acid (y1), and the molecular terminal is further changed to the polycarboxylic acid component (y). It may be modified with an anhydride (which may be trivalent or higher). In these, what modified the molecular terminal with the anhydride of (y) is preferable. The reaction ratio between the polyol component and the polycarboxylic acid component is preferably 3/1 to 1/3, more preferably 2.5 / 1 to 1/1 / as the equivalent ratio [OH] / [COOH] of the hydroxyl group to the carboxyl group. 2.5, particularly preferably 2/1 to 1/2.

  The glass transition temperature [Tg] of (A2) is preferably 45 ° C to 75 ° C, more preferably 50 ° C to 70 ° C. When [Tg] is 75 ° C. or lower, the low-temperature fixability is improved. Further, when [Tg] is 45 ° C. or higher, the blocking resistance is good.

  The flow softening point [Tm] of (A2) is not particularly limited, but is preferably 70 ° C to 120 ° C, more preferably 75 ° C to 110 ° C. When [Tm] is 70 ° C. or higher, the hot offset resistance is good, and when it is 120 ° C. or lower, the fixability is good.

Mn of the THF soluble part of the linear polyester resin (A2) is preferably 1000 to 4000, and more preferably 1100 to 3000. When Mn is 1000 or more, the resin strength necessary for fixing is expressed, and when it is 4000 or less, the low-temperature fixability is good.
Further, Mp of the THF-soluble component of (A2) is preferably 1600 to 8000, and more preferably 1700 to 7000, from the viewpoint of the balance of resin strength, low-temperature fixability, and resin grindability.

  The THF insoluble content in the linear polyester resin (A2) is preferably 5% or less from the viewpoint of low-temperature fixability. More preferably, it is 4% or less, and particularly preferably 3% or less.

  The acid value of the linear polyester resin (A2) is preferably 5 to 100. The acid value is more preferably from 10 to 80, particularly preferably from 25 to 60. When the acid value is 5 or more, the low-temperature fixability is better, and when it is 100 or less, the charging characteristics are good.

  The hydroxyl value of (A2) is preferably 5 to 125, more preferably 10 to 100. When the hydroxyl value is 5 or more, the compatibility with (A1) is good, and the glossiness (gloss) after fixing is good. Further, when the hydroxyl value is 125 or less, the storage stability becomes better.

The nonlinear polyester resin (A1) and / or the linear polyester resin (A2) is preferably an amorphous polyester resin from the viewpoints of storage stability and chargeability.
In the present invention, the “non-crystalline polyester resin” refers to a polyester having no melting point [Tmp] of 25 ° C. or higher. Tmp is measured by the following method.
<Melting point [Tmp]>
Using a differential scanning calorimeter {for example, DSC210, manufactured by Seiko Denshi Kogyo Co., Ltd.], the sample to be measured was heated to 200 ° C., cooled to 0 ° C. at a cooling rate of 10 ° C./min, and then heated to 10 ° C. Measure the endothermic change by raising the temperature at 1 min / min, draw a graph of “endothermic amount” and “temperature”, and let the temperature corresponding to the maximum peak of endothermic amount be the melting point [Tmp].

  The weight ratio [(A1) / (A2)] of the non-linear polyester resin (A1) and the linear polyester resin (A2) in the polyester resin (A) is a point of achieving both low-temperature fixability, hot offset resistance and grindability. And preferably 100/0 to 20/80, more preferably 90/10 to 25/75, and particularly preferably 85/15 to 30/70.

In the present invention, the mixing method of the polyester resins (A1) and (A2) is not particularly limited, and may be a known method that is usually performed, and may be either powder mixing or melt mixing. Further, it may be mixed at the time of toner formation.
Examples of the mixing device in the case of melt mixing include a batch type mixing device such as a reaction tank and a continuous mixing device. In order to mix uniformly in a short time at an appropriate temperature, a continuous mixer is preferable. Examples of the continuous mixing device include an extruder, a continuous kneader, and a three roll.
Examples of the mixing device for powder mixing include a Henschel mixer, a Nauter mixer, and a Banbury mixer. A Henschel mixer is preferable.

Although it does not specifically limit as an inorganic filler (F) contained in a polyester resin composition (H), A metal oxide, carbide, nitride, etc. can be illustrated and 2 or more types may be used together. Among these, boron nitride, aluminum nitride, silicon nitride, boron carbide, silicon carbide, aluminum oxide, or magnesium oxide is preferable.
In addition, the shape of the inorganic filler (F) is not particularly limited, and examples thereof include powder, fiber, scale, and the like, and preferably are fibrous. The average particle diameter calculated as the average value of the long axis and the short axis is preferably 0.001 to 1.5 μm, more preferably 0.01 to 0.5 μm. When it is less than 0.001 μm, there is an adverse effect on low-temperature fixability when used in toner, and when it exceeds 1.5 μm, an excellent effect on hot offset resistance is hardly exhibited.

  In this invention, the average particle diameter of an inorganic filler (F) is calculated by the average value of an average minor axis and an average major axis. The average minor axis and the average major axis are measured, for example, by directly observing particles with a transmission electron microscope. 50 particles are sampled indiscriminately, the minor axis and the major axis are counted individually, and the average value is taken as the average minor axis and the average major axis.

As the inorganic filler (F), one having higher thermal conductivity than the polyester resin (A) is selected from the viewpoint of low-temperature fixability, and the difference in thermal conductivity at 20 ° C. between (F) and (A) is 25 to 25 ° C. 350 W / m · K, preferably 30 to 300 W / m · K. If the difference in thermal conductivity between (F) and (A) is less than 25 W / m · K, the contribution to low-temperature fixing performance is poor, and if it exceeds 350 W / m · K, the storage stability is adversely affected.
Even if the inorganic filler (F) has a high thermal conductivity, if the volume resistivity is low, it may adversely affect the charging behavior of the toner and cause a decrease in image density. The volume resistivity by C2141 is preferably 10 ¹² to 10 ¹⁸ Ω / cm, more preferably 10 ¹³ to 10 ¹⁷ Ω / cm.
The content of the inorganic filler (F) in the polyester resin composition (H) is preferably 0.5 to 20%, more preferably 1 to 18%. When the content is 0.5% or more, the effect of improving the thermal conductivity is sufficiently exhibited and the low-temperature fixability is improved. When the content is 20% or less, the thickening due to the inorganic filler (F) is small and the low-temperature fixability is not adversely affected.

  As a method for dispersing the inorganic filler (F) in the polyester resin (A) when preparing the polyester resin composition (H), a commonly known method may be used, and examples thereof include melt mixing. Examples of the apparatus include a batch type mixing apparatus such as a reaction tank and a continuous mixing apparatus. In order to mix uniformly in a short time at an appropriate temperature, a continuous mixer is preferable. Examples of the continuous mixing device include an extruder, a continuous kneader, and a three roll.

  The thermal conductivity at 20 ° C. of the polyester resin composition (H) is preferably 0.17 to 0.3 W / m · K, more preferably 0.19 to 0, from the viewpoint of achieving both low temperature fixability and storage stability. .26 W / m · K.

In the present invention, the value of the thermal conductivity of the inorganic filler (F) is measured by a laser flash method using a value measured with a commercially available thermal conductivity meter (TC7000 manufactured by ULVAC).
The sample is a disk-shaped test piece having a diameter of 10 mm and a thickness of 2 mm, and the measurement is performed under the condition of temperature control at 20 ° C.
Further, the thermal conductivity of the polyester resin (A) and the polyester resin composition (H) is measured by the thermal resistance and thermal conductivity measurement method of JIS A1412-2-Part 2: Heat flow statistics method (HFM method) )by.

  The toner binder of the present invention contains, in addition to the polyester resin composition (H) [polyester resin (A) and inorganic filler (F)], other resins usually used as a toner binder as long as the properties thereof are not impaired. May be. Examples of the other resin include a styrene resin having Mn of 1,000 to 1,000,000, a resin having a structure in which a vinyl resin is grafted on a polyolefin resin, an epoxy resin, and a polyurethane resin. Another resin may be blended with the polyester resin (A) [nonlinear polyester resin (A1) and, if necessary, linear polyester resin (A2)], or may be partially reacted. The content of the other resin in the toner binder is preferably 10% or less, more preferably 5% or less.

  The toner of the present invention contains the toner binder of the present invention, a colorant, and, if necessary, one or more additives selected from a release agent, a charge control agent, a fluidizing agent and the like.

As the colorant, all of dyes and pigments used as toner colorants can be used. Specifically, carbon black, iron black, Sudan Black SM, First Yellow G, Benzidine Yellow, Pigment Yellow, Indian First Orange, Irgasin Red, Paranitroaniline Red, Toluidine Red, Carmine FB, Pigment Orange R, Lake Red 2G, Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalocyanine Blue, Pigment Blue, Brilliant Green, Phthalocyanine Green, Oil Yellow GG, Kayaset YG, Orazol Brown B and Oil Pink OP, etc. Or 2 or more types can be mixed and used. Further, if necessary, magnetic powder (a powder of a ferromagnetic metal such as iron, cobalt, nickel, or a compound such as magnetite, hematite, ferrite) can also be included as a colorant.
The content of the colorant is preferably 1 to 40 parts, more preferably 3 to 10 parts, with respect to 100 parts of the toner binder of the present invention. In addition, when using magnetic powder, Preferably it is 20-150 parts, More preferably, it is 40-120 parts. Above and below, parts mean parts by weight.

As the mold release agent, those having a flow softening point [Tm] of 50 to 170 ° C. are preferable, such as polyolefin wax, natural wax, aliphatic alcohol having 30 to 50 carbon atoms, fatty acid having 30 to 50 carbon atoms, and a mixture thereof. Is mentioned.
Polyolefin waxes include (co) polymers [obtained by (co) polymerization] of olefins (for example, ethylene, propylene, 1-butene, isobutylene, 1-hexene, 1-dodecene, 1-octadecene, and mixtures thereof). And olefin (co) polymer oxides with oxygen and / or ozone, maleic acid modifications of olefin (co) polymers [eg maleic acid and its derivatives (maleic anhydride, Modified products such as monomethyl maleate, monobutyl maleate and dimethyl maleate), olefins and unsaturated carboxylic acids [such as (meth) acrylic acid, itaconic acid and maleic anhydride] and / or unsaturated carboxylic acid alkyl esters [(meta ) Alkyl acrylate (C1-C1 of alkyl 8) esters and maleic acid alkyl (C1-18 alkyl) copolymers of an ester, etc.] or the like, and Sasol wax.

  Examples of natural waxes include carnauba wax, montan wax, paraffin wax, and rice wax. Examples of the aliphatic alcohol having 30 to 50 carbon atoms include triacontanol. Examples of the fatty acid having 30 to 50 carbon atoms include triacontane carboxylic acid.

  As charge control agents, nigrosine dyes, triphenylmethane dyes containing tertiary amines as side chains, quaternary ammonium salts, polyamine resins, imidazole derivatives, quaternary ammonium base-containing polymers, metal-containing azo dyes, copper phthalocyanine dyes , Salicylic acid metal salts, boron complexes of benzylic acid, sulfonic acid group-containing polymers, fluorine-containing polymers, halogen-substituted aromatic ring-containing polymers, and the like.

  Examples of the fluidizing agent include colloidal silica, alumina powder, titanium oxide powder, and calcium carbonate powder.

  The composition ratio of the toner of the present invention is preferably 30 to 97%, more preferably 40 to 95%, particularly preferably 45 to 92%; preferably the colorant, based on the toner weight. 0.05 to 60%, more preferably 0.1 to 55%, particularly preferably 0.5 to 50%; among additives, a release agent is preferably 0 to 30%, more preferably 0.5 ~ 20%, particularly preferably 1-10%; charge control agent, preferably 0-20%, more preferably 0.1-10%, particularly preferably 0.5-7.5%; Preferably, it is 0 to 10%, more preferably 0 to 5%, particularly preferably 0.1 to 4%. The total content of additives is preferably 3 to 70%, more preferably 4 to 58%, and particularly preferably 5 to 50%. When the composition ratio of the toner is in the above range, a toner having good chargeability can be easily obtained.

The toner of the present invention may be obtained by any conventionally known method such as a kneading and pulverizing method, an emulsion phase inversion method, or a polymerization method. For example, when a toner is obtained by a kneading and pulverizing method, the components constituting the toner excluding the fluidizing agent are dry blended, and then melt-kneaded, then coarsely pulverized, and finally atomized using a jet mill pulverizer or the like Further, by further classifying, the volume average particle diameter (D50) is preferably 5 to 20 μm and then mixed with a fluidizing agent. The particle size (D50) is measured using a Coulter counter [for example, trade name: Multisizer III (manufactured by Coulter)].
When the toner is obtained by the emulsion phase inversion method, the components constituting the toner excluding the fluidizing agent are dissolved or dispersed in an organic solvent, and then emulsified by adding water, etc., and then separated and classified. it can. The volume average particle diameter of the toner is preferably 3 to 15 μm.

  The toner of the present invention is mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite, magnetite, and ferrite whose surface is coated with a resin (acrylic resin, silicone resin, etc.) as necessary to cause an electrical latent. Used as an image developer. The weight ratio of toner to carrier particles is usually 1/99 to 100/0. In addition, instead of carrier particles, it can be rubbed with a member such as a charging blade to form an electrical latent image.

  The toner of the present invention is fixed on a support (paper, polyester film, etc.) by a copying machine, a printer or the like to be used as a recording material. As a method for fixing to a support, a known heat roll fixing method, flash fixing method, or the like can be applied.

  Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Production Example 1
[Synthesis of Polyester Resin (A1-1)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube (the reaction vessel used in the following production examples is also the same), 360 parts of terephthalic acid, 570 parts of bisphenol A / propylene oxide 3 mol adduct, oxyphenol of phenol novolac 50 parts of alkylene ether (number of AO units: 8) and 5 parts of tetrabutoxytitanate as a condensation catalyst were added and reacted at 230 ° C. for 5 hours while distilling off the generated water under a nitrogen stream. Subsequently, it was made to react under reduced pressure of 5-20 mmHg, and when the acid value became 1 or less, it cooled to 180 degreeC. Next, 65 parts of trimellitic anhydride was added and reacted under normal pressure for 1 hour, then reacted under reduced pressure of 20 to 40 mmHg, and taken out with a viscosity at which Tm was 140 ° C. The recovered bound water was 50 parts. The taken out resin was cooled to room temperature and then pulverized into particles. This is designated as polyester resin (A1-1).
The polyester resin (A1-1) was amorphous, Tg was 60 ° C., Tm was 140 ° C., Mp was 8000, the acid value was 28, the hydroxyl value was 7, and the THF insoluble content was 20%.

Production Example 2
[Synthesis of Polyester Resin (A1-2)]
In a reaction vessel, 381 parts of terephthalic acid, 381 parts of isophthalic acid, 448 parts of ethylene glycol, and 2 parts of tetrabutoxytitanate as a polymerization catalyst were added while distilling off water and ethylene glycol produced at 210 ° C. in a nitrogen stream. After reacting for a period of time, the reaction was carried out under a reduced pressure of 5 to 20 mmHg, and after reaching a viscosity of 83 ° C. at 1000 Pa, cooling was performed to 180 ° C. Next, 40 parts of trimellitic anhydride was added and reacted under normal pressure for 1 hour, then reacted under reduced pressure of 20 to 40 mmHg, and taken out at a predetermined Tm. The recovered ethylene glycol and bound water mixture was 252 parts. The obtained resin was cooled to room temperature and then pulverized into particles. This is designated as polyester resin (A1-2).
The polyester resin (A1-2) was amorphous, and Tg was 60 ° C., Tm was 150 ° C., Mp was 12600, acid value was 17, hydroxyl value was 8, and THF insoluble matter was 5%.

Production Example 3
[Synthesis of Polyester Resin (A2-1)]
In a reaction vessel, 482 parts of terephthalic acid, 321 parts of isophthalic acid, 600 parts of ethylene glycol, and 2 parts of tetrabutoxytitanate as a polymerization catalyst are allowed to react at 210 ° C. for 5 hours while distilling off the water generated in a nitrogen stream. Thereafter, the reaction was carried out under reduced pressure of 20 to 40 mmHg to normal pressure with a predetermined viscosity. After cooling to 200 ° C., 53 parts of trimellitic anhydride was added, and the mixture was reacted for 1 hour under normal pressure, and then taken out. The recovered ethylene glycol and bound water was 458 parts. The obtained resin was cooled to room temperature and then pulverized into particles. This is designated as polyester resin (A2-1).
The polyester resin (A2-1) was amorphous, Tg was 62 ° C., Mp was 6300, the acid value was 31, and the hydroxyl value was 20.

Production Example 4
[Preparation of inorganic filler (F-2)]
After adding 10 parts of sodium dodecyl sulfate to 790 parts of ion-exchanged water and homogenizing it, boron nitride (hexagonal crystal) fine particles [manufactured by Mizushima Alloy, HP-40, diameter 7.0 μm, thermal conductivity 60 W / m · K , Volume resistivity 10 ¹⁴ ] was added for homogenization. This dispersion was dispersed with Dynomill [Shinmaru Enterprises Co., Ltd.] for 2.5 hours to obtain an aqueous dispersion of inorganic particles. Dynamic light scattering particle size measurement method [The measuring instrument is manufactured by Otsuka Electronics Co., Ltd .: DLS-7000, and the sample was prepared by diluting an inorganic particle aqueous dispersion 400 times with ion-exchanged water. The average particle size of the inorganic particles measured by the above method was 0.4 μm. This inorganic particle aqueous dispersion was dehydrated with a film evaporator at a temperature of 40 ° C., and then dried in a dryer at 40 ° C. for 1 hour to obtain an inorganic filler (F-2).

Production Example 5
[Preparation of inorganic filler (F-3)]
After adding 10 parts of sodium dodecyl sulfate to 790 parts of ion-exchanged water and homogenizing, fine aluminum nitride particles (Tokuyama Soda Co., Ltd., diameter 1.9 μm, thermal conductivity 200 W / m · K, volume resistivity 10 ¹⁴ ) are added. Homogenized. This dispersion was dispersed with Dynomill [manufactured by Shinmaru Enterprises Co., Ltd.] for 15 hours to obtain an aqueous dispersion of inorganic particles. Dynamic light scattering particle size measurement method [The measuring instrument is manufactured by Otsuka Electronics Co., Ltd .: DLS-7000, and the sample was prepared by diluting an inorganic particle aqueous dispersion 400 times with ion-exchanged water. The average particle size of the inorganic particles measured by the above method was 0.5 μm. The inorganic particle aqueous dispersion was dehydrated with a film evaporator at a temperature of 40 ° C., and then dried in a dryer at 40 ° C. for 1 hour to obtain an inorganic filler (F-3).

Production Example 6
[Preparation of inorganic filler (F-4)]
Polyvinylpyrrolidone (PVP) 10 parts is added to a solution of 96 parts of 20% aqueous ammonia and 1600 parts of ethanol to form PVP fibers having an average minor axis of 20 nm, an average major axis of 0.8 μm, and an aspect ratio of 40. In addition to a solution of 96 parts of 20% aqueous ammonia and 1600 parts of ethanol, the mixture was dispersed using a stirrer. To this dispersion, 20 parts of aluminum isopropoxide dissolved in 200 parts of isopropanol was dropped in 24 hours, and allowed to stand for 24 hours after the end of dropping. Subsequently, after filtering a dispersion liquid, it dried at 60 degreeC for 10 hours, and obtained the composite heat conductive filler (FA-4) which formed the heat conductive layer on the cellulose fiber surface. The composite heat conductive filler (FA-4) had an average minor axis of 23 nm, an average major axis of 0.8 μm, an aspect ratio of 35, a thermal conductive layer average thickness of 3 nm, and a density of 1.6 g / cm ³ . This composite heat conductive filler (FA-4) is heated at 1400 ° C. for 1 hour in an ammonia gas atmosphere containing 5% by volume of propane gas, whereby aluminum nitride fibers (heat conductivity 200 W / m · K, volume) Specific resistance 10 ¹⁴ ) A hollow inorganic filler (F-4) which is a hollow body was obtained. (F-4) had an average minor axis of 23 nm, an average major axis of 0.8 μm, and an average particle diameter of 0.4 μm.

As the inorganic filler (F), in addition to those prepared in Production Examples 4 to 6, the following were used.
[Inorganic filler (F-1)]
Aluminum oxide particles [manufactured by Nippon Light Metal Co., Ltd., A32, average particle size 0.5 μm, thermal conductivity 42 W / m · K, volume resistivity 10 ¹⁷ ] were used as the inorganic filler (F-1).
[Inorganic filler (F-5)]
Silicon nitride particles [manufactured by Ube Industries, Ltd., average particle size 0.6 μm, thermal conductivity 45 W / m · K, volume resistivity 10 ¹³ ] were used as the inorganic filler (F-5).
[Inorganic filler (RF-1)]
Aluminum nitride particles [manufactured by Tokuyama Soda Co., Ltd., average particle diameter of 1.9 μm, thermal conductivity of 200 W / m · K, volume resistivity of 10 ¹⁴ ] were used as the inorganic filler (RF-1).
[Inorganic filler (RF-2)]
Copper particles from Sumitomo Metal Mining Co., Ltd., average particle diameter 0.4 .mu.m, the thermal conductivity of 375 W / m · K, a volume resistivity ^10-6] was used as a mineral filler (RF-2).
[Inorganic filler (RF-3)]
Silica particles [amorphous type, manufactured by Nippon Shokubai Co., Ltd., average particle size 0.5 μm, thermal conductivity 1 W / m · K, volume resistivity 10 ¹⁴ ] were used as inorganic fillers (RF-3).

Examples 1-8, Comparative Examples 1-4
Polyester resins (A1-1), (A1-2), (A2-1) obtained in the above production examples, inorganic fillers (F-1) to (F-5), (RF-1) to (RF- 3) The chromatic pigment (copper phthalocyanine pigment) “ECB-301” (manufactured by Dainichi Seika Co., Ltd.), carnauba wax, and charge control agent “T-77” (manufactured by Hodogaya Chemical Co., Ltd.) ) And toner binders (P-1) to (P-8) of the present invention comprising the polyester resin composition (H) by the following methods, and comparative toner binders (RP-1) to (RP-4). ) And toner.
First, after premixing using a Henschel mixer [FM10B manufactured by Mitsui Miike Chemical Co., Ltd.], the mixture was kneaded at 140 ° C. using a biaxial kneader [PCM-30 manufactured by Ikegai Co., Ltd.]. Next, the mixture was finely pulverized using a supersonic jet crusher lab jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], and then classified by an airflow classifier [MDS-I manufactured by Nippon Pneumatic Industry Co., Ltd.], and an average particle diameter D50. To 8 μm toner particles were obtained. Next, 100 parts of toner particles were mixed with 0.5 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil) using a sample mill, and the toners (T-1) to (T-8) of the present invention, and a comparative sample were mixed. Toners (RT-1) to (RT-4) were obtained.

  Table 1 shows the results of evaluation by the following methods using the toners (T-1) to (T-8) and the comparative toners (RT-1) to (RT-4).

[1] Minimum fixing temperature (MFT)
An unfixed image developed using a commercial copying machine (AR5030; manufactured by Sharp) was evaluated using a fixing machine of a commercial copying machine (AR5030; manufactured by Sharp). The lower limit temperature at which the residual ratio of the image density after rubbing the fixed image with a pad becomes 70% or more was defined as the minimum fixing temperature.
[2] Hot offset generation temperature (HOT)
The fixing was evaluated in the same manner as the MFT, and the presence or absence of hot offset on the fixed image was visually evaluated. The upper limit temperature at which hot offset does not occur after passing through the fixing roll was defined as hot offset generation temperature.
[3] Toner storability test The above toner was tested at 50 ° C. and 85% R.V. H. Was conditioned for 48 hours in a high temperature and high humidity environment. Under the same environment, the blocking state of the developer was visually determined, and the image quality when copying with a commercially available copying machine (AR5030: manufactured by Sharp) was observed.
Criteria A: There is no toner blocking, and the image quality after copying 3000 sheets is good.
○: There is no toner blocking, but a slight disturbance is observed in the image quality after copying 3000 sheets.
X: Toner blocking is visible and no image is produced by 3000 sheets [4] Thermal conductivity According to the above method.
[5] Image Density Unfixed solid image developed using a commercially available monochrome copying machine (AR5030, manufactured by Sharp Corporation) and remodeling the fixing unit of a commercially available monochrome copying machine (SF8400A, manufactured by Sharp Corporation) Fixing was performed at a heat roller temperature of 180 ° C. and a process speed of 213 mm / sec using a fixing machine with variable hot roller temperature and variable process speed. The image density of the fixed image was measured using a Macbeth reflection densitometer RD-191 (manufactured by Macbeth).
○: ID1.4 or more △: ID1.3 or more and less than 1.4 ×: ID less than 1.3

  The toner and toner binder of the present invention are excellent in both low temperature fixability and hot offset resistance (fixing temperature range) and excellent storage stability (blocking resistance), and are used for electrophotography, electrostatic recording, electrostatic printing and the like. It is useful as a toner for charge image development and a toner binder.

Claims (7)

  A polyester resin (A) composed of a nonlinear polyester resin (A1) containing a trivalent or higher monomer in the structural unit and, if necessary, a linear polyester resin (A2), and an average particle size of 0.001 to 1.5 μm The difference in thermal conductivity at 20 ° C. between the polyester resin (A) and the inorganic filler (F) is 25 to 350 W / m · K, and the inorganic filler (F) is contained in the polyester resin (A). A toner binder containing a polyester resin composition (H) in which (F) is dispersed.   The toner binder according to claim 1, wherein the content of the inorganic filler (F) in the polyester resin composition (H) is 0.5 to 20% by weight. The toner binder according to claim 1 or 2, wherein the inorganic filler (F) has a volume specific resistance at 20 ° C of 1 × 10 ¹² to 1 × 10 ^18.   The toner binder according to claim 1, wherein the polyester resin composition (H) has a thermal conductivity at 20 ° C. of 0.17 to 0.3 W / m · K.   The toner binder according to claim 1, wherein the inorganic filler (F) is one or more selected from metal oxides, carbides, and nitrides.   The toner binder according to claim 1, wherein the nonlinear polyester resin (A1) and / or the linear polyester resin (A2) is an amorphous polyester resin.   A toner comprising the toner binder according to any one of claims 1 to 6, a colorant, and, if necessary, one or more additives selected from a release agent, a charge control agent, and a fluidizing agent.