JP5274969B2 - Toner binder and toner composition - Google Patents

Description

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

In the electrophotographic field, a toner that satisfies the demand for higher speed and higher image quality is desired, and from the environmental aspect, it is desired not to use harmful substances such as heavy metals.
In particular, for dibutyltin oxide conventionally used as a catalyst for esterification, the toxicity of residual tributyltin is a problem. Although a method of using a catalyst such as titanium instead of dibutyltin oxide is known (see Patent Documents 1 and 2), the charge amount is likely to decrease under high temperature and high humidity, or the toner binder is likely to be colored. Therefore, the image quality is insufficient.
JP 2005-314686 A JP 2008-15271 A

  An object of the present invention is to provide a toner binder that can be produced without using a tin compound, has no environmental concerns, has excellent charging stability, and provides a high-quality image stably even during continuous printing, and the toner binder It is an object to provide a toner composition containing the toner.

As a result of intensive studies to solve these problems, the present inventors have reached the present invention.
That is, the present invention contains a polyester resin (A) obtained by condensation polymerization of a polyol component (x) containing an aliphatic diol (x1) and a polycarboxylic acid component (y), and the aliphatic diol (x1) It is ethylene glycol and / or 1,2-propylene glycol, and 80 to 100 mol% of the polycarboxylic acid component (y) is terephthalic acid, isophthalic acid, trimellitic acid, lower alkyl thereof (1 to 4 carbon atoms) One or more selected from esters and acid anhydrides thereof, the content of the aliphatic diol (x1) in the polyol component (x) is 70 to 100 mol%, and the polyester resin (A) is titanium. Is a resin obtained by polycondensation in the presence of a polymerization catalyst containing an aliphatic diol (x1) in the polyester resin (A) of 0.3% by weight. A toner binder in which the content of the aliphatic diol (x1) in the toner binder is 0.3% by weight or less; and the toner binder, colorant, and if necessary, a release agent, a charge control agent, magnetic A toner composition containing at least one additive selected from powder and a fluidizing agent.

  According to the present invention, there is provided a toner binder that is free from environmental concerns, has excellent charging stability, and stably provides a high-quality image even during continuous printing, and a toner composition containing the toner binder. It has become possible.

The present invention is described in detail below.
The toner binder of the present invention includes a polyester resin (A) obtained by condensation polymerization of a polyol component (x) containing an aliphatic diol (x1) having 2 to 12 carbon atoms and a polycarboxylic acid component (y). The proportion of the polyester resin (A) in the toner binder of the present invention is arbitrary, but from the viewpoint of transparency and fixability, the content of (A) is preferably 50 to 100% by weight, more preferably 60 to 100% by weight, particularly preferably 70 to 100% by weight.
The resin that can be used in the toner binder of the present invention together with the polyester resin (A) is a polyester resin that does not contain an aliphatic diol (x1) having 2 to 12 carbon atoms in the polyol component [of bisphenol A as the polyol component. Polyester resin using (poly) oxyalkylene, etc.], styrene-acrylic resin, epoxy resin and the like.

The content of the aliphatic diol (x1) having 2 to 12 carbon atoms in the toner binder of the present invention is 1% by weight or less. The content of (x1) is preferably 0.7% by weight or less, more preferably 0.02 to 0.5% by weight, particularly preferably 0.05 to 0.3% by weight. When the aliphatic diol (x1) having 2 to 12 carbon atoms exceeds 1% by weight, the charge amount of the toner is not sufficiently stabilized, and fogging occurs during continuous printing or the image density tends to change. It is in.
The content of the aliphatic diol having 2 to 12 carbon atoms (x1) in the polyester resin (A) is preferably 1% by weight or less, more preferably 0.7% by weight or less, for the same reason as above. Particularly preferred is 0.02 to 0.5% by weight, and most preferred is 0.05 to 0.3% by weight.

  In addition, content of a C2-C12 aliphatic diol (x1) in this invention is measured with the following method by the gas chromatography method.

Dissolve 1 g of resin in 20 ml of chloroform, add 1 g of chloroform solution of internal standard substance (concentration 1% by weight) and analyze by gas chromatography. From the calibration curve of aliphatic diol (x1) and internal standard substance, fat The content of the group diol (x1) was calculated.
-Gas chromatography: GC-17A (manufactured by Shimadzu Corporation)
Column: DB-5 (manufactured by J & W)
-Carrier gas: helium, nitrogen-Carrier linear velocity: 30 cm / sec-Detector: Hydrogen flame ionization detector-Column temperature: 80-250 ° C (temperature increase rate: 10 ° C / min)
• Internal standard substance: 1-hexanol • Calibration curve: Aliphatic diol (x1) and internal standard substance were mixed and measured at five different weight ratios.

  The polyol component (x) constituting the polyester resin (A) used for the toner binder of the present invention includes an aliphatic diol (x1) having 2 to 12 carbon atoms, which is an essential component, and an oil having 6 to 36 carbon atoms. Cyclic diol (x2), (poly) oxyalkylene of bisphenols [alkylene group having 2 to 4 carbon atoms, and the same as the following (poly) oxyalkylene groups] ether (x3), trivalent or more having 3 to 36 carbon atoms Polyol (x4) and the like.

  The aliphatic diol (x1) having 2 to 12 carbon atoms can be used in any proportion in the polyol component (x), but the content of (x1) in (x) is preferably 40 to 100 mol%. More preferably, it is 70-100 mol%, Most preferably, it is 90-100 mol%. When the aliphatic diol (x1) having 2 to 12 carbon atoms is used in an amount of 40 mol% or more, even when a polymerization catalyst containing titanium, zirconium, nickel, aluminum, or the like is used, coloring is hardly caused, and high image quality is achieved. It is advantageous.

  Examples of the aliphatic diol (x1) having 2 to 12 carbon atoms include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, Examples include 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, and the like. Among these, preferred are aliphatic diols having 2 to 4 carbon atoms, more preferred are ethylene glycol and / or 1,2-propylene glycol, and particularly preferred is ethylene glycol.

  Examples of the alicyclic diol (x2) having 6 to 36 carbon atoms include 1,4-cyclohexanedimethanol and hydrogenated bisphenol A.

  Examples of the (poly) oxyalkylene ether (x3) of bisphenols include (poly) oxyalkylene ethers (number of oxyalkylene groups: 1 to 30) such as bisphenol A, bisphenol F, and bisphenol S.

  Examples of the trivalent or higher (3 to 8 or higher) polyol (x4) include aliphatic polyhydric alcohols such as glycerin, pentaerythritol, trimethylolpropane, and sorbitol, and novolak resins (phenol novolak and cresol novolak, etc .: average (Poly) oxyalkylene ether having a polymerization degree of 3 to 60) (number of oxyalkylene groups: 1 to 30).

Examples of the polycarboxylic acid component (y) include dicarboxylic acids and trivalent or higher polycarboxylic acids.
Examples of the dicarboxylic acid include alkane dicarboxylic acids having 4 to 36 carbon atoms (for example, succinic acid, adipine, 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 (for example, alkenyl succinic acids such as dodecenyl succinic acid, malee, fumar, citracone, and mesaconic acid); aromatic dicarboxylic acids having 8 to 36 carbon atoms (phthal, isophthal, terephthalic, and naphthalenedicarboxylic acid) Etc.), and lower alkyls thereof (alkyl group having 1 to 4 carbon atoms: methyl, ethyl, n-propyl, etc.) esters and acid anhydrides];
Examples of the tricarboxylic or higher (3 to 6 or higher) polycarboxylic acid include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid), and lower alkyl esters thereof, and An acid anhydride etc. are mentioned.
Among these, preferred are alkane dicarboxylic acids having 4 to 36 carbon atoms, aromatic dicarboxylic acids having 8 to 20 carbon atoms, and aromatic polycarboxylic acids having 9 to 20 carbon atoms, and lower alkyl esters and acid anhydrides thereof. More preferred are adipic acid, maleic acid, fumaric acid, terephthalic acid, isophthalic acid, trimellitic acid and / or lower alkyl esters thereof.

In the polycarboxylic acid component (y), at least one content selected from terephthalic acid, isophthalic acid, trimellitic acid, lower alkyl (carbon number 1 to 4) ester thereof, and acid anhydride thereof, From the viewpoint of storage stability, it is preferably 80 to 100 mol%, more preferably 85 to 100 mol%.
The molar ratio of terephthalic acid and / or its lower alkyl ester to isophthalic acid and / or its lower alkyl ester is preferably 20:80 to 100: 0, more preferably 25 from the viewpoint of the mechanical strength of the resin. : 75 to 100: 0.

The polycondensation of the polyol component (x) and the polycarboxylic acid component (y) when obtaining the polyester resin (A) used in the present invention can be carried out using a known esterification reaction and transesterification reaction. As a general method, for example, in an inert gas (nitrogen gas or the like) atmosphere, the reaction temperature is preferably 150 to 280 ° C., more preferably 180 to 270 ° C., and particularly preferably 200 to 260 ° C. It can be carried out. The reaction time is preferably 30 minutes or longer, particularly 2 to 40 hours from the viewpoint of reliably performing the condensation polymerization reaction.
It is also effective to reduce the pressure in order to improve the reaction rate at the end of the reaction.
The reaction ratio between the polyol component (x) and the polycarboxylic acid component (y) is preferably 2/1 to 1/2, more preferably 1. as the equivalent ratio [OH] / [COOH] of the hydroxyl group to the carboxyl group. 5/1 to 1 / 1.3, particularly preferably 1.3 / 1 to 1 / 1.2.

In order to reduce the content of the aliphatic diol (x1) having 2 to 12 carbon atoms in the toner binder, which is a feature of the present invention, to 1% by weight or less, for example, the following methods (1) and (2) are used. A polyester resin (A) may be produced using a combination thereof.
(1) A polycondensation reaction between a polyol component (x) containing an aliphatic diol (x1) having 2 to 12 carbon atoms and a polycarboxylic acid (y) is carried out, and then a polycarboxylic acid (y) is further added once. A multi-step reaction technique in which the above is added (preferably 1 to 3 times, more preferably 2 times) and subjected to condensation polymerization.
(2) A method of reacting until the hydroxyl value is 40 or less, more preferably 30 or less, particularly preferably 20 or less, and most preferably 15 or less.

  The hydroxyl value is potassium hydroxide required to neutralize acetic acid bonded to hydroxyl groups when acetylating 1 g of a sample measured according to JIS K0070 or the standard oil analysis method (edited by the Japan Oils and Fats Chemical Society). The number of milligrams.

  When obtaining the polyester resin (A), it is preferable to use a polymerization catalyst containing one or more metals selected from titanium, zirconium, nickel, and aluminum from the viewpoint of the environment, and it is more preferable to use a titanium-containing catalyst. preferable.

Examples of the titanium-containing catalyst include titanium alkoxide, potassium oxalate titanate, titanium terephthalate, and catalysts described in JP-A-2006-243715 [titanium dihydroxybis (triethanolamate), titanium monohydroxytris (triethanolaminate). , And their intramolecular condensates, etc.], and catalysts described in JP-A No. 2007-11307 (titanium tributoxy terephthalate, titanium triisopropoxy terephthalate, titanium diisopropoxy diterephthalate, etc.) and the like.
Zirconyl acetate etc. are mentioned as a zirconium containing catalyst.
Nickel acetylacetonate etc. are mentioned as a nickel containing catalyst.
Examples of the aluminum-containing catalyst include aluminum hydroxide and aluminum triisopropoxide.

  The amount of the catalyst added is desirably determined as appropriate so as to maximize the reaction rate. The amount added is preferably 10 ppm to 1.9% by weight, more preferably 100 ppm to 1.7% by weight, based on all raw materials. The amount added is preferably 10 ppm or more, so that the reaction rate is increased.

  Tetrahydrofuran (THF) soluble content of the polyester resin (A) used in the present invention [A solution in which (A) is adjusted to a concentration of 0.25 wt% with THF. If insolubles are present, they are removed by filtration. The number average molecular weight measured by gel permeation chromatography is preferably 1000 to 12000, more preferably 1500 to 10,000, and particularly preferably 2000 to 8000, from the viewpoints of low-temperature fixability and grindability.

  In the present invention, the polyester resin (A) may be modified to such an extent that its properties are not substantially impaired. Examples of the modified polyester include grafting and blocking with phenol, urethane, epoxy and the like by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, and the like. Polyester

The glass transition temperature (Tg) of the polyester binder (A) used in the present invention and the toner binder of the present invention containing (A) is preferably 45 ° C. or higher from the viewpoint of storage stability. Further, from the viewpoint of low-temperature fixability, it is preferably 75 ° C. or lower, particularly 65 ° C. or lower.
In addition, in the above and below, Tg is measured by the method (DSC method) prescribed | regulated to ASTM D3418-82 using Seiko Denshi Kogyo Co., Ltd. DSC20, SSC / 580.

Further, the softening point of the toner binder of the present invention is preferably 95 to 170 ° C, more preferably 105 to 160 ° C. In this range, the balance between hot offset resistance and low-temperature fixability is good.
The softening point is a value measured as follows.
Using a descending flow tester {for example, CFT-500D, manufactured by Shimadzu Corporation), a load of 1.96 MPa was applied by a plunger while heating a measurement sample of 1 g at a heating rate of 6 ° C./min. Extrude from a nozzle with a diameter of 1 mm and a length of 1 mm, draw a graph of “plunger descent amount (flow value)” and “temperature”, and graph the temperature corresponding to 1/2 of the maximum plunger descent amount And this value (temperature when half of the measurement sample flows out) is taken as the softening point.

  The toner composition of the present invention contains the toner binder of the present invention, a colorant, and, if necessary, one or more additives such as a release agent, a charge control agent, a magnetic powder, and a fluidizing agent.

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.

  The release agent preferably has a softening point of 50 to 170 ° C., and examples thereof include polyolefin wax, natural wax, aliphatic alcohol having 30 to 50 carbon atoms, fatty acid having 30 to 50 carbon atoms, and a mixture thereof. 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 (alkyl 1 to 1 carbon atoms) 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 composition of the present invention is preferably 30 to 97% by weight, more preferably 40 to 95% by weight, particularly preferably 45 to 92% by weight, based on the toner weight. The agent is preferably 0.05 to 60% by weight, more preferably 0.1 to 55% by weight, particularly preferably 0.5 to 50% by weight; among the additives, the release agent is preferably 0 to 30%. % By weight, more preferably 0.5 to 20% by weight, particularly preferably 1 to 10% by weight; the charge control agent is preferably 0 to 20% by weight, more preferably 0.1 to 10% by weight, particularly preferably 0.5 to 7.5% by weight; The fluidizing agent is preferably 0 to 10% by weight, more preferably 0 to 5% by weight, and particularly preferably 0.1 to 4% by weight. In addition, when magnetic powder is added as a charging aid without functioning as a colorant, the addition amount is preferably 0 to 1.0% by weight, more preferably 0.01 to 0.7% by weight, especially. Preferably it is 0.05 to 0.5 weight%. The total content of additives is preferably 3 to 70% by weight, more preferably 4 to 58% by weight, and particularly preferably 5 to 50% by weight. When the composition ratio of the toner is in the above range, a toner having good chargeability can be easily obtained.

The toner composition 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 average particle diameter (D50) is preferably 5 to 20 μm and then mixed with a fluidizing agent. The average particle size (D50) (D50 is the particle size when the number larger than a certain particle size in the volume particle size distribution of powder represents 50% of the total number of powders) is Coulter counter [ For example, it can measure using a brand name: Multisizer III (made 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 composition of the present invention is electrically mixed with carrier particles such as ferrite coated on the surface with iron powder, glass beads, nickel powder, ferrite, magnetite, and resin (acrylic resin, silicone resin, etc.) as necessary. Used as a latent 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 composition of the present invention is fixed on a support (paper, polyester film, etc.) by a copying machine, a printer, or the like to form a recording material. As a method for fixing to the support, a known hot 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.

[Synthesis of titanium-containing catalyst]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube capable of bubbling in the liquid, 126 parts of ethyl acetate and 200 parts of terephthalic acid are placed and gradually heated to 60 ° C. under bubbling in liquid with nitrogen. Then, 1617 parts of titanium tetraisopropoxide was added dropwise to react at 60 ° C. for 4 hours to obtain a slurry-like reaction mixture. The reaction mixture was filtered with a filter paper and dried at 40 ° C./20 kPa · s to obtain a mixture (t) of titanium triisopropoxyterephthalate and unreacted terephthalic acid (titanium triisopropoxyterephthalate concentration 65% by weight). .

Production Example 1
[Synthesis of polyester resin (A1)]
In a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, 415 parts of terephthalic acid, 415 parts of isophthalic acid, 32 parts of adipic acid, 800 parts of ethylene glycol, 0.5 part of (t) as a polymerization catalyst, While distilling off the water produced under a nitrogen stream, the temperature was raised to 210 ° C. and reacted for 6 hours, and then reacted under reduced pressure of 5 to 20 mmHg for 1.5 hours. At this time, the hydroxyl value was 45. Subsequently, 50 parts of trimellitic anhydride was added, and the mixture was reacted for 1 hour under normal pressure, and then reacted for 2 hours under a reduced pressure of 20 to 40 mmHg. Further, 32 parts of trimellitic anhydride was added and reacted under normal pressure for 1 hour, and then reacted under reduced pressure of 20 to 40 mmHg and taken out at a predetermined softening point. The obtained resin was cooled to room temperature and then pulverized into particles. This is designated as polyester resin (A1).
The hydroxyl value of (A1) was 13, the content of ethylene glycol was 0.1% by weight, and the softening point was 140 ° C.

Production Example 2
[Synthesis of polyester resin (A2)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 320 parts of terephthalic acid, 480 parts of isophthalic acid, 10 parts of trimellitic anhydride, dioxy (1,2-propylene) ether of bisphenol A (manufactured by Sanyo Chemical) , Newpol BP-2P) 50 parts, ethylene glycol 800 parts, (t) 0.5 part as a polymerization catalyst, heated to 210 ° C. while distilling off the water produced under a nitrogen stream, reacted for 6 hours Then, the mixture was reacted for 1.5 hours under a reduced pressure of 5 to 20 mmHg. At this time, the hydroxyl value was 41. Next, 63 parts of trimellitic anhydride was added and reacted under normal pressure for 1 hour, and then reacted under reduced pressure of 20 to 40 mmHg and taken out at a predetermined softening point. The obtained resin was cooled to room temperature and then pulverized into particles. This is designated as polyester resin (A2).
(A2) had a hydroxyl value of 11, an ethylene glycol content of 0.3% by weight, and a softening point of 139 ° C.

Production Example 3
[Synthesis of polyester resin (A3)]
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 692 parts of terephthalic acid, 65 parts of adipic acid, 7 parts of trimellitic anhydride, 780 parts of 1,2-propylene glycol, (t) 0 as a polymerization catalyst .5 parts was added, and the reaction was carried out while distilling off the water produced under the conditions of 230 ° C. and 500 kPa until it became transparent and uniform, followed by reaction under reduced pressure of 5 to 20 mmHg for 3 hours. At this time, the hydroxyl value was 42. Subsequently, 44 parts of trimellitic anhydride was added and reacted for 1 hour under normal pressure, and then reacted for 2 hours under reduced pressure of 20 to 40 mmHg. Further, 25 parts of trimellitic anhydride was added and reacted for 1 hour under normal pressure, then reacted under reduced pressure of 20 to 40 mmHg and taken out at a predetermined softening point. The obtained resin was cooled to room temperature and then pulverized into particles. This is designated as polyester resin (A3).
The hydroxyl value of (A2) was 5,1,2-propylene glycol content was 0.2% by weight, and the softening point was 145 ° C.

Production Example 4
[Synthesis of polyester resin (B1)]
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 431 parts of terephthalic acid, 282 parts of dioxy (1,2-propylene) ether of bisphenol A (manufactured by Sanyo Chemical Co., Ltd., Newpol BP-2P), bisphenol A 812 parts of dioxyethylene ether (manufactured by Sanyo Chemical Co., Ltd., Newpol BPE-20) and 0.5 part of (t) as a polymerization catalyst were added and reacted at 230 ° C. under reduced pressure of 5 to 20 mmHg for 10 hours. Next, after cooling to 190 ° C., 64 parts of trimellitic anhydride was added, and the mixture was reacted at normal pressure for 1.5 hours, and then taken out. The obtained resin was cooled to room temperature and then pulverized into particles. This is designated as polyester resin (B1).
Tg of (B1) was 63 ° C., and the softening point was 101 ° C.

Comparative production example 1
[Synthesis of polyester resin (RA1)]
392 parts of terephthalic acid, 392 parts of isophthalic acid, 40 parts of trimellitic anhydride, 800 parts of ethylene glycol and 0.5 part of (t) as a polymerization catalyst in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe The mixture was heated up to 210 ° C. and reacted for 5 hours while distilling off the water produced under a nitrogen stream, and then reacted under a reduced pressure of 5 to 20 mmHg and taken out at a predetermined softening point. The obtained resin was cooled to room temperature and then pulverized into particles. This is designated as a comparative polyester resin (RA1).
(RA1) had a hydroxyl value of 47, an ethylene glycol content of 1.2% by weight, and a softening point of 130 ° C.

Comparative production example 2
[Synthesis of polyester resin (RA2)]
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 680 parts of terephthalic acid, 70 parts of adipic acid, 780 parts of 1,2-propylene glycol, 0.5 part of (t) as a polymerization catalyst were added, and 230 The reaction was carried out while distilling off the water generated under the conditions of 500 ° C. and 500 kPa until it became transparent and uniform, followed by reaction under reduced pressure of 5 to 20 mmHg for 1 hour. At this time, the hydroxyl value was 85. Next, 30 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 softening point. The obtained resin was cooled to room temperature and then pulverized into particles. This is referred to as a comparative polyester resin (RA2).
The hydroxyl value of (A2) was 44, the content of 1,2-propylene glycol was 1.3% by weight, and the softening point was 128 ° C.

Examples 1-4, Comparative Examples 1-3
The polyester resins (A1) to (A3) and the comparative polyester resins (RA1) to (RA2) and the polyester resin (B1) obtained in Production Examples 1 to 4 and Comparative Production Examples 1 to 2 are ratios shown in Table 1. (Part) is melt-mixed using a twin-screw mixer, stirred at 140 ° C. for 5 minutes and melt-mixed, and the toner binders (TB1) to (TB4) of the present invention and the comparative toner binder (RTB1) To (RTB3). For 100 parts of each toner binder, 80 parts of magnetic powder (manufactured by Toda Kogyo Co., EPT-1000), 5 parts of polyethylene wax (manufactured by Sanyo Chemical Industries, Sunwax 171P), charge control agent (manufactured by Hodogaya Chemical Co., Ltd., T -77) 2 parts were added and converted to toner by the following method.
First, after pre-mixing using a Henschel mixer [FM10B manufactured by Mitsui Miike Chemical Co., Ltd.], the mixture was kneaded using a twin-screw kneader [PCM-30 manufactured by Ikegai Co., Ltd.]. Subsequently, the mixture was finely pulverized using a supersonic jet pulverizer, Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], and then classified with an airflow classifier to obtain toner particles having a volume average particle diameter (D50) of 8 to 9 μm. . Next, 100 parts of the toner particles are mixed with 0.5 part of colloidal silica (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) using a small mixer, and the toner compositions (T1) to (T4) of the present invention and a comparative toner composition are mixed. (RT1) to (RT3) were obtained.

The toner composition was evaluated by the following method.
[Saturation charge, charge rise, charge stability]
0.5 g of the toner composition and 20 g of ferrite carrier (F-150, manufactured by Powdertech Co., Ltd.) are placed in a 50 ml glass bottle, which is placed at 23 ° C., 50% R.D. H. After adjusting the humidity for 8 hours or more, the mixture was frictionally stirred at 50 rpm × 1, 3, 5, 10, 20 and 60 minutes using a tumbler shaker mixer, and the charge amount was measured for each time. For the measurement, a blow-off charge measuring device [manufactured by Toshiba Chemical Co., Ltd.] was used.
The amount of charge with a friction time of 10 minutes was taken as the saturation charge amount, and the following criteria were used for evaluation. In addition, “charge amount for 1 minute of friction time / charge amount for 10 minutes of friction time” was calculated, and the rising property of charge was evaluated according to the following criteria. Further, “charge amount of 60 minutes friction time / charge amount of 10 minutes friction time” was calculated, and charging stability was evaluated according to the following criteria.
The evaluation results are shown in Table 1.

[Evaluation criteria for saturation charge]
A: Absolute value of saturation charge amount is 25 μC / g or more. ○: Absolute value of saturation charge amount is 20 μC / g or more and less than 25 μC / g. Δ: Absolute value of saturation charge amount is 15 μC / g or more and less than 20 μC / g. : Absolute value of saturation charge is less than 15 μC / g

[Evaluation criteria for charging rise]
◎: 0.7 or more ○: 0.6 or more, less than 0.7 △: 0.5 or more, less than 0.6 ×: less than 0.5

[Evaluation criteria for charging stability]
◎: 0.8 or more ○: 0.7 or more, less than 0.8 △: 0.6 or more, less than 0.7 ×: less than 0.6

  From the above results, it can be seen that the toner compositions of the examples are superior in charging characteristics as compared with the toner compositions of the comparative examples. Compared with the toner of the comparative example, the saturated charge amount and the charging stability are particularly excellent, and thus a high-quality image can be stably provided even during continuous printing. Furthermore, a catalyst having a low toxicity can be used as a polymerization catalyst when producing polyester, and environmental requirements are met.

  The toner binder and toner composition of the present invention can be suitably used in printing systems such as electrophotography, electrostatic recording, and electrostatic printing.

Claims (2)

  A polyester resin (A) obtained by polycondensation of a polyol component (x) containing an aliphatic diol (x1) and a polycarboxylic acid component (y), wherein the aliphatic diol (x1) is ethylene glycol and / or 1,2-propylene glycol, and 80 to 100 mol% of the polycarboxylic acid component (y) is terephthalic acid, isophthalic acid, trimellitic acid, their lower alkyl (1 to 4 carbon atoms) ester, and these A polymerization catalyst which is one or more selected from acid anhydrides, the content of the aliphatic diol (x1) in the polyol component (x) is 70 to 100 mol%, and the polyester resin (A) contains titanium. In which the content of the aliphatic diol (x1) in the polyester resin (A) is 0.3% by weight or less, and the toner. Toner binder content of the aliphatic diol (x1) in Indah is 0.3 wt% or less.   A toner composition comprising the toner binder according to claim 1, a colorant, and, if necessary, one or more additives selected from a release agent, a charge control agent, a magnetic powder, and a fluidizing agent.