JP2000029246A - Toner binder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a toner binder providing a dry toner excellent in both low temp. fixability and anti-hot-offsetting property, having the adequate quantity of electric charges and excellent also in environmental stability by making the dielectric tangent in the specified frequency of a polyester to a specified value or less. SOLUTION: The dielectric tangent (tan δ) of a polyester consisting of a toner binder is normally <=8×10-3, preferably 7×10-3-1×10-4, further preferably 6×10-3-5×10-4, particularly preferably 5×10-3-1×10-3 at 100 kHz measured frequency. In the case of >8×10-3, the quantity of electric charges is insufficient and the environmental stability deteriorates. A dry toner using the toner binder is used as an electrostatic latent image developer optionally after mixing with carrier particles such as iron powder, glass beads, nickel powder, ferrite, magnetite or ferrite whose surface is coated with an acrylic resin or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a toner binder for a dry toner used in electrophotography, electrostatic recording, electrostatic printing, and the like.

[0002]

2. Description of the Related Art Conventionally, as a dry toner used in electrophotography and the like, a toner binder such as styrene acrylic resin or polyester is melt-kneaded together with a coloring agent and the like.
Finely pulverized ones are used. These dry toners are frictionally charged with a carrier such as ferrite powder or a charging member, and developed into an electrostatic latent image formed on a photoreceptor. Then, after transferring to paper or the like, fixing is performed by heating and melting using a hot roll.
In that case, it is necessary to have an appropriate charge amount in order to develop with sufficient image density. In addition, the difference in charge amount is small at any temperature and humidity (environmental stability)
Is required. Further, on the fixing surface, from the viewpoint of energy saving and downsizing of a copying machine or the like, the toner does not fuse to the hot roll even at a higher hot roll temperature than before (hot-offset resistance) and the hot roll temperature is low. However, it is required that the toner can be fixed (low-temperature fixability). In recent years, polyester toner binders have attracted attention because of their excellent low-temperature fixability and hot offset resistance. However, a toner using a polyester-based toner binder has a problem that the environmental stability of charging is insufficient. Further, the magnetic toner containing magnetic powder has a problem that the charge amount is low and a sufficient image density cannot be obtained. In particular, in a small developing device used for a printer or the like, the problem of the shortage of the charge amount is remarkable.

[0003]

In order to solve the problems of the charge amount and the environmental stability of the above-mentioned polyester-based toner binder, a method of compounding a styrene acrylic resin which is superior in charge characteristics with polyester (for example, Japanese Patent Application Laid-Open No. Sho 62-62). −
195682, JP-A-2-881 and JP-A-4-142301) have been proposed. However, although those disclosed in these documents have improved charge amount and environmental stability compared to conventional polyesters,
It has only intermediate properties between polyester and styrene acrylic resin, and is inferior in charging characteristics to styrene acrylic resin. Further, the characteristics of polyester are also reduced by half in terms of low-temperature fixability and hot offset resistance.

[0004]

Means for Solving the Problems The present inventors have developed a toner binder which is excellent in both low-temperature fixability and hot-offset resistance, has a proper charge amount and is excellent in environmental stability, and provides a dry toner. As a result of intensive studies for development, the present invention has been reached. That is, the present invention relates to a toner binder comprising the polyester (A), wherein the dielectric tangent (tan δ) at a measurement frequency of 100 kHz of (A) is 8 × 10 ⁻³ or less.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The dielectric loss tangent (tan δ) of the polyester (A) constituting the toner binder of the present invention is usually 8 × 10 ⁻³ or less, preferably 7 × 10 ^{−3 at a} measurement frequency of 100 kHz.
１1 × 10 ^-4 , more preferably 6 × 10 ^{-3 to} 5 × 10
^-4 , particularly preferably 5 × 10 ⁻³ to 1 × 10 ⁻³ . t
When an δ exceeds 8 × 10 ⁻³ , the charge amount becomes insufficient and the environmental stability deteriorates. The dielectric loss tangent can be measured, for example, by melting and kneading the resin using a Labo Plastomill at 130 ° C. and 70 rpm for 30 minutes, then pulverizing the resin to 20 μm or less, compression molding, and using a commercially available dielectric loss measuring device. .

The glass transition point (Tg) of (A) is usually-
The temperature is 30 ° C. or higher, preferably 0 to 80 ° C., more preferably 25 to 75 ° C., and particularly preferably 35 to 75 ° C. (A) When used alone as a toner binder, the temperature is preferably 35 ° C. or higher from the viewpoint of heat-resistant storage stability.
Even when the temperature is lower than 5 ° C., it can be used as a resin (α) complexed with another resin (B) described later. Even when compounding,
It is preferable that the Tg of (A) is -30 ° C or higher from the viewpoint of heat-resistant storage stability.

The polyester (A) includes an amorphous polyester (A1) and a crystalline polyester (A2). Among these, (A1) is preferable because of excellent powder fluidity and heat-resistant storage stability. Examples of (A) include a polycondensate of a polyol and a polycarboxylic acid. Examples of the polyol include a diol (1) and a trivalent or higher valent polyol (2), and examples of the polycarboxylic acid include a dicarboxylic acid (3) and a trivalent or higher polycarboxylic acid (4). In the present invention, a non-linear polyester using a tri- or higher valent polyol (2) and / or a tri- or higher valent polycarboxylic acid (4) together with the diol (1) and the dicarboxylic acid (3) is preferable.
Polyesters composed of the four components (1), (2), (3) and (4) are particularly preferred. The hot offset resistance is further improved by using both (2) and (4).

As the diol (1), alkylene glycols (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, dodecanediol, etc.); Ether glycols (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, hydrogenated bisphenol F, etc.) Bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.); alkylene oxides of the above alicyclic diols (ethylene oxide, propylene oxide) And alkylene oxides of the above-mentioned bisphenols (such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, and α-olefin oxide). Among these, preferred are alkylene glycols having 6 or more carbon atoms, alkylene oxide adducts of bisphenols, and alicyclic diols, and particularly preferred are propylene oxide, butylene oxide, styrene oxide, and α-olefin oxide of bisphenols. Adducts, alkylene glycols having 8 or more carbon atoms, hydrogenated bisphenol A, hydrogenated bisphenol F, and combinations thereof. As the trivalent or higher polyol (2),
8 or more polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane,
Pentaerythritol, sorbitol, etc .; trisphenols (trisphenol PA, etc.); novolak resins (phenol novolak, cresol novolak, etc.); alkylene oxide adducts of the above trisphenols; alkylene oxide adducts of the above novolak resins. . Preferred of these are:
An alkylene oxide adduct of a polyhydric aliphatic alcohol having 3 to 8 or more valences and a novolak resin,
Particularly preferred are alkylene oxide adducts of novolak resins.

The dicarboxylic acids (3) include alkylenedicarboxylic acids (succinic acid, adipic acid, azelaic acid,
Sebacic acid, dodecane dicarboxylic acid, octadecane dicarboxylic acid, dodecenyl succinic acid, pentadecenyl succinic acid, octadecenyl succinic acid, dimer acid, etc.); alkenylene dicarboxylic acid (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acid ( Phthalic acid, isophthalic acid,
Terephthalic acid, naphthalenedicarboxylic acid, etc.). Among these, preferred are those having 6 to 5 carbon atoms.
0 alkylene dicarboxylic acids, 6 to 50 carbon atoms of alkenylene dicarboxylic acids, 8 to 20 carbon atoms of aromatic dicarboxylic acids, and combinations thereof. More preferred are alkylene dicarboxylic acids of 7 to 50 carbon atoms, and And an aromatic dicarboxylic acid having 8 to 20 carbon atoms. Particularly preferred are alkenyl succinic acids having 16 to 50 carbon atoms, and a combination of these with alkenyl succinic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polycarboxylic acid (4) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid) and vinyl polymers of unsaturated carboxylic acids (styrene / maleic acid copolymerization). Product, styrene / acrylic acid copolymer, α-olefin /
Maleic acid copolymer, styrene / fumaric acid copolymer, etc.). Preferred of these are:
An aromatic polycarboxylic acid having 9 to 20 carbon atoms is particularly preferable, and trimellitic acid is particularly preferable. In addition, as the dicarboxylic acid (3) or the trivalent or higher polycarboxylic acid (4), the above-mentioned acid anhydride or lower alkyl ester (eg, methyl ester, ethyl ester, isopropyl ester) may be used.

The hydroxycarboxylic acid (5) can be copolymerized with (1), (2), (3) and (4). Examples of the hydroxycarboxylic acid (5) include hydroxystearic acid and hydrogenated castor oil fatty acid.

The ratio of the polyol to the polycarboxylic acid is determined by the equivalent ratio [OH] of the hydroxyl group [OH] and the carboxyl group [COOH].
/ [COOH] is usually 2/1 to 1/2, preferably 1.5 / 1 to 1 / 1.5, and more preferably 1.3 / 1.
１ ／ 1 / 1.3. The ratio of the trivalent or higher polyol (2) and the trivalent or higher polycarboxylic acid (4) is such that the sum of the number of moles of (2) and (4) is based on the total number of moles of (1) to (4). Thus, it is usually 0 to 40 mol%, preferably 3 to 25 mol%, and more preferably 5 to 20 mol%. (2)
And the molar ratio of (3) is usually 0/100 to 100/0,
Preferably it is 80/20-20/80, More preferably, it is 70/30-30/70.

The hydroxyl value of (A) is usually 70 mgKOH / g or less, preferably 40 mgKOH / g or less, more preferably 3 mgKOH / g or less.
It is 0 mgKOH / g or less. It is preferable that the hydroxyl value is small from the viewpoint of improving environmental stability and charge amount. The acid value of (A) is usually 0 to 50 mgKOH / g, preferably 5 to 50 mgKOH / g.
/ g, more preferably 8 to 30 mgKOH / g, particularly preferably 8 to 25 mgKOH / g. A smaller acid value improves environmental stability, but a moderate acid value is preferred in that the rise of charging is improved.

As the toner binder of the present invention, the above-mentioned polyester (A) may be used alone, but resin (α) obtained by compounding (A) with another resin (B) may also be used. The combination of (B) having a smaller tan δ than (A) is preferable in that the charge amount and environmental stability are further improved. The tan δ of (B) is usually 5 × 10 ⁻³ or less,
Preferably not more than 2 × 10 ⁻³ , more preferably 1.5 ×
10 ⁻³ to 1 × 10 ⁻⁵ , particularly preferably 1 × 10 ^{−3 to} 5 ×
10 ^-4 . The Tg of (B) is usually 30 to 150 ° C, preferably 45 to 100 ° C, and more preferably 50 to 95 ° C.
° C. Like (A), (B) is more preferably an amorphous resin than a crystalline resin from the viewpoint of powder fluidity and heat-resistant storage stability.

Other resins (B) include addition condensation resins,
Examples include vinyl resins, polyaddition resins, and polycondensation resins.
Of these, vinyl resins and addition condensation resins are preferred, and vinyl resins are particularly preferred. Examples of the addition condensation resin include a xylene resin, phenol novolak, cresol novolak, and the like, and among these, a xylene resin is preferable. Examples of the vinyl resin include a styrene resin, an acrylic resin, a polyolefin, a polycycloalkene, a polyalkenylcycloalkane, and a halogenated vinyl resin. Of these, preferred are styrene resins. As styrene resin,
Examples thereof include a styrene polymer (B1), a styrene and diene copolymer (B2), and a styrene and alkyl (meth) acrylate copolymer (B3). Among these, preferred are (B1) and (B2), copolymers of styrenes and alkyl (meth) acrylates having a C8 to C24 alkyl group, and combinations thereof. (B
The styrenes constituting 1) include styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, p-methoxystyrene, p-hydroxystyrene,
p-acetoxystyrene and the like. Of these, styrene and a combination of styrene and other styrenes are preferred, and styrene is particularly preferred.

The styrenes constituting (B2) include:
The same as the above (B1) are mentioned, and the preferable ones are also the same. Dienes include butadiene, isoprene, chloroprene, hexadiene and octadiene. Preferred among these are butadiene, isoprene and chloroprene, and particularly preferred are butadiene and isoprene. (B
In 2), a small amount of other monomers together with styrenes and dienes can be copolymerized. Other copolymerizable monomers include alkyl (meth) acrylate [methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, Stearyl (meth) acrylate, etc.], substituted alkyl (meth) acrylates [hydroxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, etc.], unsaturated carboxylic acids and their anhydrides [(meth) acrylic acid, maleic acid, Fumaric acid, itaconic acid and anhydrides thereof], alkyl esters of unsaturated dicarboxylic acids [monomethyl maleate, monobutyl maleate, dibutyl maleate, monomethyl itaconate], unsaturated nitriles [(meth) acrylonitrile, etc. , Vinyl esters [vinyl acetate, etc.], [such as butyl vinyl] vinyl ethers, alpha-olefins [hexene, octene, dodecene, etc.] and the like. Among these, preferred are alkyl (meth) acrylates, unsaturated carboxylic acids and their anhydrides, unsaturated dicarboxylic acid alkyl esters, and unsaturated nitriles, and more preferably a long chain having a C8 to C24 alkyl group. Chain alkyl (meth) acrylates, unsaturated carboxylic acids and their anhydrides, and unsaturated dicarboxylic acid alkyl esters. Carboxylic acid-containing monomers such as unsaturated carboxylic acids and their anhydrides, and unsaturated dicarboxylic acid monoalkyl esters, have a large tan δ when copolymerized in large amounts, but a small amount of copolymer has poor pigment dispersibility. It is preferable in terms of improvement. The copolymerization ratio of other monomers copolymerizable with styrenes and dienes is usually 60 to 99% by weight of styrenes, 1 to 40% by weight of dienes, and 0 to 10% by weight of other monomers. %, Preferably 70 to 95% by weight of styrenes, 5 to 30% by weight of dienes, and 0 to 5% by weight of other monomers.

The styrenes constituting (B3) include:
The same as the above (B1) are mentioned, and the preferable ones are also the same. As the alkyl (meth) acrylate,
Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, tetradecyl (meth) acrylate, hexadecyl (meth) acrylate, Examples include stearyl (meth) acrylate and behenyl (meth) acrylate. Among these, preferred are long-chain alkyl (meth) acrylates having an alkyl group of C8 to C24, and more preferred are long-chain alkyl (meth) acrylates having an alkyl group of C12 to C22, and particularly preferred. Those are lauryl (meth) acrylate and stearyl (meth) acrylate. In (B3), other monomers can be copolymerized with styrenes and alkyl (meth) acrylates. Examples of the other copolymerizable monomer include those similar to the above (B2) and dienes. Among these, preferred are dienes, unsaturated carboxylic acids and anhydrides thereof, alkyl esters of unsaturated dicarboxylic acids and unsaturated nitriles, and more preferably diene, unsaturated carboxylic acids and anhydrides thereof, and unsaturated nitriles. It is a saturated dicarboxylic acid alkyl ester. Carboxylic acid-containing monomers such as unsaturated carboxylic acids and their anhydrides, and unsaturated dicarboxylic acid monoalkyl esters, have a large tan δ when copolymerized in large amounts, but a small amount of copolymer has poor pigment dispersibility. It is preferable in terms of improvement. The copolymerization ratio of other monomers copolymerizable with styrenes and alkyl (meth) acrylates is usually 70 to 99% by weight of styrenes, 1 to 30% by weight of alkyl (meth) acrylate, and other monomers. The styrenes are 80 to 95% by weight, the alkyl (meth) acrylate is 5 to 20% by weight,
Other monomers are 0 to 5% by weight.

Polyester (A) and other resin (B)
Is usually 10/90 to 100/0, preferably 10/90 to 90/10, and more preferably 25/90 to 90/10.
/ 75 to 80/20. The higher the ratio of polyester, the better the low-temperature fixability and the resistance to hot offset, and the higher the ratio of other resins, the better the environmental stability and the amount of charge.

In the present invention, (α) may be a mixture of (A) and (B), or (A) and (B) may be chemically bonded. A resin in which at least a part of (A) and (B) is chemically bonded is preferable in that tan δ is reduced, and environmental stability and charge amount are further improved. Examples of the resin in which (A) and (B) are chemically bonded include a block copolymer and a graft copolymer.

The molecular weight of the toner binder of the present invention is G
The PC preferably has a maximum value of a molecular weight of 1,000 to 20,000, more preferably a maximum value of 2
000 to 19000, particularly preferably a maximum value of 3000
１５15000. When it is 1,000 or more, heat-resistant storage stability and powder fluidity are improved, and when it is 20,000 or less, pulverizability is improved. Further, the THF insoluble content is 5-6.
The content is preferably 0% by weight, more preferably 15 to 50%, particularly preferably 20 to 45%. Hot offset resistance is improved by incorporating a THF-insoluble component.

Specific examples of the toner binder of the present invention include the following. Hydrogenated bisphenol A / propylene novolak propylene oxide adduct / dodecenyl succinic acid / adipic acid polycondensate Bisphenol A propylene oxide 2 mol adduct / hydrogenated bisphenol A / phenol novolak propylene oxide adduct / dodecenyl succinic anhydride / trimellitic anhydride Polycondensate Hydrogenated bisphenol A / phenol novolak propylene oxide adduct / adipic acid / sebacic acid polycondensate Bisphenol A propylene oxide 2 mol adduct / hydrogenated bisphenol A / phenol novolak propylene oxide adduct / dodecenyl succinic acid / anhydride Mixture of trimellitic acid polycondensate, styrene polymer and styrene / butadiene copolymer 2 mol of bisphenol A propylene oxide Product / propylene oxide adduct of phenol novolak / dodecenylsuccinic acid / maleic anhydride / trimellitic anhydride polycondensate grafted with styrene bisphenol A propylene oxide 2 mol adduct / hydrogenated bisphenol A / propylene novolak propylene oxide Mixture of adduct / dodecenyl succinic acid / maleic anhydride / trimellitic anhydride polycondensate with styrene and styrene / stearyl methacrylate copolymer Hydrogenated bisphenol A / sebacic acid / trimellitic anhydride polycondensate Of styrene / glycidyl methacrylate copolymer and propylene oxide adduct of hydrogenated bisphenol A / phenol novolak / dodecenyl succinic acid /
(Styrene / monobutyl maleate copolymer) polycondensate

The method for producing the toner binder of the present invention will be exemplified. The polyester (A) is prepared by subjecting a polycarboxylic acid and a polyol to 150-150 in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide.
It is obtained by heating to 280 ° C. and performing dehydration condensation. It is also effective to reduce the pressure in order to improve the reaction rate at the end of the reaction. The vinyl resin is obtained by copolymerizing constituent monomers with a known radical initiator. Examples of the radical initiator include azo initiators (azobisisobutyronitrile, azobisvaleronitrile, etc.) and peroxide initiators (benzoyl peroxide, t-butyl perbenzoate, di-t-butyl peroxide, di- t
-Butyl peroxyhexahydroterephthalate, etc.)
And the like. Known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization can be used as the polymerization method. Solvents used in the solution polymerization include aromatic solvents (toluene, xylene, etc.); ketone solvents (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.); halogen solvents (dichloroethane, etc.); and amide solvents (dimethyl, etc.) Formamide) can be used. When a solvent is used, the solvent is distilled off under normal pressure and reduced pressure after polymerization. When obtained by suspension polymerization, polymerization can be carried out in water using an inorganic dispersant such as calcium carbonate or calcium phosphate or an organic dispersant such as polyvinyl alcohol or methylated cellulose. The polymerization temperature is selected depending on the molecular weight of the radical initiator and the toner binder to be used, but is usually 5 to 200C, preferably 50 to 170C. The polymerization time is usually 1 to 48 hours, preferably 2 to 2 hours.
4 hours. The method for producing the composite resin (α)
In the case of a mixture of (A) and (B), any method such as a polymerization method in the presence, a solution mixing method, a melt mixing method, and a powder mixing method can be used. In the presence polymerization method, it is obtained by polymerizing the other monomer in the presence of (A) or (B). In the solution mixing method, it is obtained by dissolving separately polymerized (A) and (B) in a solvent similar to the solvent usable for the solution polymerization of the vinyl resin, and then distilling off the solvent. In the melt mixing method,
Either a batch type or a continuous type can be applied. In the case of a continuous type, it is obtained by kneading at 100 to 230 ° C. using an extruder or the like. In the case of a batch type, 15
Mix at 0-230 ° C. In the powder mixing method, the powder is obtained by mixing powders of the respective components using a Nauta mixer, a Henschel mixer, or the like. The resin in which (A) and (B) are chemically bonded can be produced by the following known method or the like. A method in which a double bond is introduced into a polyester by using fumaric acid or the like, and the polyester and a monomer constituting the vinyl resin are copolymerized. A method of polycondensing a vinyl-based resin having a carboxyl group or a hydroxyl group (obtained by copolymerizing maleic anhydride, acrylic acid, hydroxymethacrylate, etc.) with a monomer constituting the polyester. A method in which a vinyl-based resin having a hydroxyl group and a carboxyl group of a polyester and a functional group (an acid anhydride group, an epoxy group, an isocyanate group, and the like) capable of reacting with the polyester group is polymerized.

The toner binder of the present invention is used as a dry toner by mixing a colorant and, if necessary, various additives such as a release agent and a charge control agent. Known dyes, pigments, and magnetic powders can be used as the colorant. Specifically, carbon black, Sudan Black SM, Fast Yellow-G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgasin Red, Baranitoaniline Red, Toluidine Red, Carmine FB, Pigment Orange R, Lake Red 2G, Rhodamine FB, Rhodamine B lake, Methyl Violet B lake, phthalocyanine blue, pigment blue, pliant green, phthalocyanine green, oil yellow GG, Kayaset YG, Orazol Brown B, oil pink OP, magnetite, iron black, and the like. The content of the colorant in the toner is usually 2 to 15% by weight when using a dye or a pigment, and usually 20 to 70% by weight when using a magnetic powder.
It is.

Known release agents can be used, for example, polyolefin waxes (polyethylene wax, polypropylene wax, etc.); long-chain hydrocarbons (paraffin wax, sasol wax, etc.); carbonyl group-containing waxes ( Carnauba wax, montan wax, distearyl ketone, etc.). The content of the release agent in the toner is usually 0 to 10% by weight,
Preferably it is 1 to 7% by weight. As charge control agents,
Known ones, such as nigrosine dyes, quaternary ammonium salt compounds, quaternary ammonium base-containing polymers, metal-containing azo dyes, salicylic acid metal salts, sulfonic acid group-containing polymers, fluorine-containing polymers, and halogen-substituted aromatic ring-containing polymers, etc. Can be The content of the charge control agent in the toner is usually 0 to 5% by weight. In addition, fluidizing agents can be used. Known fluidizers such as colloidal silica, alumina powder, titanium oxide powder, and calcium carbonate powder can be used.

As a method for producing a dry toner, a known kneading and pulverizing method can be used. After the above-mentioned toner components are dry-blended, they are melt-kneaded, then finely pulverized using a jet mill or the like, and further subjected to air classification to have a particle size of usually 2 to 2.
Obtained as 0 μm particles.

The dry toner using the toner binder of the present invention may contain iron powder, glass beads, nickel powder,
It is used as a developer for an electric latent image by being mixed with carrier particles such as ferrite, magnetite, and ferrite whose surface is coated with a resin (such as an acrylic resin or a silicone resin). In addition, instead of the carrier particles, friction with a member such as a charging blade can be performed to form an electric latent image. Next, the recording material is fixed on a support (paper, polyester film, etc.) by a known heat roll fixing method or the like.

Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited to these examples. Hereinafter, "part" indicates "part by weight".

【Example】

The methods for measuring the properties of the toner binders obtained in Examples and Comparative Examples are described below. 1. Acid value and hydroxyl value Method specified in JIS K0070. If the sample has solvent-insoluble components due to crosslinking,
A sample after melt-kneading was used as a sample by the following method. Kneading device: Labo Plast Mill manufactured by Toyo Seiki Co., Ltd.
MODEL30R150 Kneading conditions: 130 ° C, 70 rpm for 30 minutes 2. Glass transition point (Tg) The method (DSC) specified in ASTM D3418-82
Law). Apparatus: DSC20, SSC manufactured by Seiko Electronic Industry Co., Ltd.
/ 580 3. Molecular weight The soluble matter in THF was measured by gel permeation chromatography (GPC). The conditions for molecular weight measurement by GPC are as follows. Apparatus: HLC-802A manufactured by Toyo Soda Column: 2 TSK GEL GMH6 (manufactured by Toyo Soda) Measurement temperature: 25 ° C. Sample solution: 0.25 wt% tetrahydrofuran solution Solution injection amount: 200 μl Detector: Refractive index detector The molecular weight calibration curve was created using standard polystyrene. 4. Tetrahydrofuran (THF) insoluble matter 50 ml of THF is added to 0.5 g of a sample, and the mixture is refluxed with stirring for 3 hours. After cooling, the insoluble matter is filtered off with a glass filter and dried under reduced pressure at 80 ° C. for 3 hours. The insoluble content is calculated from the weight ratio of the resin on the glass filter to the weight of the sample. 5. Dielectric loss tangent (tan δ) measurement device: Ando Electric Co., Ltd. TR-1100 dielectric loss measuring device Electrode: Ando Electric Co., Ltd. SE-43 type powder electrode After melting and kneading by the following method, 20 μm The following pulverized material was used as a sample. Kneading device: Labo Plastomill MODEL30R150 manufactured by Toyo Seiki Co., Ltd. Kneading conditions: 130 ° C., 70 rpm for 30 minutes

Example 1 In a reactor equipped with a cooling pipe, a stirrer and a nitrogen introducing pipe,
Bisphenol A propylene oxide 2 mol adduct 1
64 parts, hydrogenated bisphenol A 339 parts, phenol novolak resin (number of nuclei: about 5) propylene oxide 5 mol adduct 40 parts, dodecenyl succinic anhydride 4
90 parts and 2 parts of dibutyltin oxide were added, and reacted at 220 ° C. under normal pressure for 8 hours.
The reaction was performed for 5 hours under reduced pressure. Next, 55 parts of trimellitic anhydride was added thereto and reacted at a reduced pressure of 10 to 15 mmHg to obtain a melt index (180 ° C., 2160 g).
Was taken out of the reaction tank when it became 0.5 g / 10 min,
Thus, the toner binder (1) of the present invention was obtained. The THF-insoluble content of the toner binder (1) is 42%, and the peak molecular weight is 7
800, the glass transition point (Tg) was 59 ° C., and tan δ was 4.6 × 10 ⁻³ .

Example 2 (Synthesis of polyester) In the same manner as in Example 1, bisphenol A propylene oxide 2 mol adduct 506
Parts, 87 parts of hydrogenated bisphenol A, 15 parts of a 5 mol propylene oxide adduct of a phenol novolak resin (about 5 nuclei), 29.5 parts of maleic anhydride, and 394 parts of dodecenyl succinic anhydride in dibutyltin oxide 2 The reaction was carried out at 220 ° C. using the part as a catalyst. Then 18
After cooling to 0 ° C., 28 parts of trimellitic anhydride were added and reacted at 180 ° C. under normal pressure for 2 hours to obtain polyester (A).
1) was obtained. Tg of polyester (A1) is 43 ° C., t
an δ was 4.9 × 10 ⁻³ . (Synthesis of Toner Binder) Put 320 parts of xylene into an autoclave reaction vessel equipped with a thermometer and a stirrer,
After the replacement with nitrogen, a mixed solution of 500 parts of polyester (A1), 500 parts of styrene, and 5 parts of di-t-butyl peroxide was added dropwise at 170 ° C. for 2 hours to polymerize. Next, the resultant was dried under reduced pressure at 200 ° C. to obtain a toner binder (2) of the present invention. The THF-insoluble content of the toner binder (2) is 38%, the peak molecular weight is 11,000, the Tg is 60 ° C.,
tan δ was 1.9 × 10 ⁻³ . Polyester (A
Styrene was similarly polymerized using 500 parts of xylene instead of 1). The polystyrene obtained has a Tg of 78 ° C.
tan δ was 1.1 × 10 ⁻⁴ .

Example 3 (Synthesis of styrene resin) In an autoclave reactor equipped with a thermometer and a stirrer, 2,000 parts of water and 3 parts of polyvinyl alcohol were sufficiently dissolved, and then 850 parts of styrene and 150 parts of butadiene were added thereto. Mixed monomer and di-t-butylperoxyhexahydroterephthalate 2
After nitrogen replacement, the mixture was heated at 85 ° C. for 10 hours,
Suspension polymerization was performed at 3 ° C. for 3 hours. After cooling, the reaction product was separated by filtration, washed with water, and dried at 50 ° C. to obtain a styrene resin (B1). Tg of the styrene resin (B1) is 54 ° C., tan δ
Was 1.0 × 10 ⁻⁴ . (Synthesis of polyester) In the same manner as in Example 1, 501 parts of hydrogenated bisphenol A, 127 parts of sebacic acid,
Maleic anhydride (10.4 parts) and dodecenyl succinic anhydride (371 parts) were mixed with 2 parts of dibutyltin oxide as a catalyst.
The reaction was carried out at 20 ° C. to obtain a polyester (A2). Polyester (A2) has a Tg of 57 ° C. and a tan δ of 5.8 ×.
It was 10 ^-3 . (Synthesis of Toner Binder) Place 250 parts of xylene in an autoclave reaction vessel equipped with a thermometer and a stirrer,
After the replacement with nitrogen, a mixed solution of 400 parts of polyester (A2), 400 parts of styrene, and 12 parts of di-t-butyl peroxide was added dropwise at 170 ° C. for 2 hours to polymerize. Next, 200 parts of styrene resin (B1) and xylene 7
50 parts were added, dissolved and dispersed, and dried under reduced pressure at 200 ° C. to obtain a toner binder (3) of the present invention. The THF-insoluble content of the toner binder (2) is 23%, the peak molecular weight is 7100, the Tg is 63 ° C., and the tan δ is 2.3 × 10 3
^{Was -3} .

Comparative Example 1 In a reactor equipped with a cooling pipe, a stirrer and a nitrogen introducing pipe,
Bisphenol A propylene oxide 2 mol adduct 3
48 parts, bisphenol A ethylene oxide 2 mol adduct 320 parts, terephthalic acid 166 parts, fumaric acid
5 parts, 54 parts of dodecenylsuccinic anhydride, 0.1 part of hydroquinone and 2 parts of dibutyltin oxide were added, and reacted at 230 ° C. under normal pressure for 12 hours.
The reaction was performed under reduced pressure of Hg for 3 hours. Next, 64 parts of trimellitic anhydride was added and reacted at a reduced pressure of 10 to 15 mmHg. When the acid value reached 20, the reaction product was taken out of the reaction vessel.
Polyester (A3) was obtained. (A3) has a THF insoluble content of 32%, a peak molecular weight of 6,200, and a Tg of 59.
° C and tan δ were 1.2 × 10 ^-2 . Polyester (A3) is used as comparative toner binder (1).

Comparative Example 2 (Synthesis of styrenic resin) Styrene 720
Parts and 280 parts of butyl acrylate, and polymerized in the same manner as the styrene resin (B1) of Example 3 to obtain a resin (B
2-1) was obtained. 450 parts of xylene was placed in an autoclave reaction vessel equipped with a thermometer and a stirrer, and after purging with nitrogen, a mixed monomer of 870 parts of styrene, 130 parts of butyl acrylate, and di-t-butyl peroxide 1
A mixture of 5 parts and 120 parts of xylene was added dropwise at 170 ° C. over 3 hours to carry out polymerization. Next, the solvent is removed and the resin (B2-2) is removed.
I got 300 parts of resin (B2-1) and resin (B2-2)
700 parts were added to 1000 parts of xylene and dissolved under reflux. Next, the resultant was dried at 180 ° C. under reduced pressure to obtain a styrene resin (B2). (B2) had a Tg of 61 ° C. and a tan δ of 1.9 × 10 ⁻³ . (Synthesis of Toner Binder) Polyester (A3) 50
0 parts and 500 parts of a styrene resin (B2) were powder-mixed, and then kneaded with a biaxial kneader (PCM-30, manufactured by Ikegai Co., Ltd.) to obtain a comparative toner binder (2). The tan δ of the comparative toner binder (2) was 6.1 × 10 ⁻³ .

Evaluation Examples 1 to 3 and Comparative Evaluation Examples 1 and 2 To 100 parts of the toner binders (1) to (3) and the comparative toner binders (1) and (2) of the present invention, magnetic powder (Toda Kogyo Co., Ltd.) was used. ) EPT-1000), 100 parts of low molecular weight polypropylene (Viscol 550P manufactured by Sanyo Chemical Industries, Ltd.), 4 parts, charge control agent T-77 (Hodogaya Chemical)
(Manufactured)), and the mixture was converted into a toner by the following method. First, a Henschel mixer (FM1 manufactured by Mitsui Miike Kakoki Co., Ltd.)
OB), and kneaded with a twin-screw kneader (PCM-30, manufactured by Ikegai Co., Ltd.). Then supersonic jet crusher Lab Jet (manufactured by Nippon Pneumatic Industries, Ltd.)
After finely pulverizing by using an airflow classifier (MDS-I manufactured by Nippon Pneumatic Industries, Ltd.), the particle size d50 is 8
μm toner particles were obtained. Next, 1 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil) was mixed with 100 parts of the toner particles using a sample mill to obtain toners (1) to (3), comparative toners (1) and (2). Table 1 shows the evaluation results.

[0034]

[Table 1] ---------------------------------------------------------------------------- Toner No Image density (N / N) Image Concentration (H / H) MFT HOT-----------------------------Toner (1) 52 1.24 120 ° C 230 ° C Toner (2) 1.55 1.37 125 ° C 230 ° C Toner (3) 1.54 1.31 125 ° C 220 ° C Comparative toner (1) 0.82 0.64 125 ° C 200 ° C Comparative toner (2) 1.28 0.85 130 ° C 190 ° C ------------------------------------------------- --- [Evaluation method] Image density A black solid image was printed using a commercially available laser printer (LBP-210; manufactured by Canon Inc.), and the image density was measured using a Macbeth densitometer. Develop at room temperature and humidity (23
C., 50% RH) is referred to as image density (N / N), and that performed at high temperature and high humidity (35.degree. C., 85% RH) is referred to as image density (H / H). Minimum fixing temperature (MFT) An unfixed image developed using a commercially available laser printer (LBP-210; manufactured by Canon) is converted to a commercially available copier (SF
(8400A; manufactured by Sharp) was modified and evaluated using a fixing machine having a paper feeding speed of 160 mm / sec and a variable fixing temperature. The minimum fixing temperature was the fixing roll temperature at which the residual ratio of the image density after rubbing the fixed image with a pad was 70% or more. Hot offset occurrence temperature (HOT) The fixing was evaluated in the same manner as in the above MFT, and the presence or absence of hot offset to the fixed image was visually evaluated. The temperature of the fixing roll at which the hot offset occurred was defined as the hot offset occurrence temperature.

[0035]

The toner binder of the present invention has the following effects. 1. When a dry toner is used, the charge amount is appropriate and the environment stability is excellent. In particular, the magnetic toner has a high charge amount and a high image density. 2. Excellent in both low-temperature fixability and hot offset resistance. 3. Excellent durability and little deterioration of image after long-term copying.

Claims (8)

[Claims] 1. A toner binder comprising a polyester (A), wherein a dielectric loss tangent (tan δ) at a measurement frequency of 100 kHz of (A) is 8 × 10 ⁻³ or less. 2. The method according to claim 1, wherein (A) has a glass transition point (Tg) of-
The toner binder according to claim 1, which is an amorphous polyester having a temperature of 30 ° C or higher. 3. A toner binder comprising a resin (α) obtained by combining the polyester (A) according to claim 1 or 2 with another resin (B) having a dielectric loss tangent (tan δ) of 5 × 10 ⁻³ or less. . 4. The toner binder according to claim 3, wherein (α) is a resin in which (A) and at least a part of (B) are chemically bonded. 5. The toner binder according to claim 3, wherein (B) is an amorphous resin having a Tg of 30 to 150 ° C. 6. The content of (A) in (α) is from 10 to 9
The toner binder according to any one of claims 3 to 5, which is 0% by weight. 7. The toner binder according to claim 3, wherein (B) is a vinyl resin. 8. The toner binder according to claim 7, wherein the vinyl resin is a styrene resin.