JP4348243B2 - Polyester resin for toner and toner composition - Google Patents

Description

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

A polyester resin for an electrostatic charge image developing toner for a thermal fixing system is one in which at least a part of a polyol component is a propylene oxide (hereinafter referred to as PO) adduct of bisphenol A from the viewpoint of charging stability and the like. Often used (see, for example, Patent Documents 1 and 2). A polyester resin composed of a polyol component containing a PO adduct of bisphenol A is generally obtained by polycondensation from a polyol and a polycarboxylic acid or a lower alkyl ester thereof using a tin compound as a catalyst.
Japanese Patent Laid-Open No. 11-72959 JP-A-5-27478

  However, a toner using a polyester resin containing a PO adduct of bisphenol A has not been sufficiently durable. Further, although a polyester resin not containing a tin compound is desired from the viewpoint of environmental problems in recent years, when a catalyst other than a tin compound is used, the durability of the toner tends to be further insufficient. An object of the present invention is to provide a polyester resin for toner excellent in charging stability and durability.

The inventor has intensively studied to solve these problems, and has reached the present invention.
That is, the present invention relates to a polyester resin for toner obtained by polycondensation of a polyol component and a polycarboxylic acid component, wherein at least a part of the polyol component is a bisphenol A having 30 to 100 mol% primary hydroxyl groups in the terminal hydroxyl groups. It comprises a propylene oxide adduct (a), a polyester resin for toner, and a colorant, and optionally comprises at least one additive selected from a mold release agent, a charge control agent, and a fluidizing agent. Toner composition.

  The polyester resin of the present invention is a binder resin for toner that has excellent durability and good charging stability despite containing the PO adduct of bisphenol A. Furthermore, a highly safe toner that does not contain tin, which is a harmful metal, can be provided.

The present invention is described in detail below.
In the polyester resin for toner obtained by polycondensation of the polyol component and the polycarboxylic acid component of the present invention, at least a part of the polyol component is composed of a PO adduct (a) of bisphenol A having a primary hydroxyl group. When the polyol component does not contain (a), the durability of the toner is lowered.

The PO adduct (a) of bisphenol A containing a primary hydroxyl group has a primary hydroxyl group at one or both ends. The average added mole number of PO in (a) is preferably 2.8 to 5.2, more preferably 3 to 4.5. When the average number of added moles is 2.8 to 5.2, the charging stability is better.
From the viewpoint of improving the durability of the toner, the primary hydroxylation rate should be high, preferably 30% or more, more preferably 40% or more, particularly preferably 50%, most preferably 60% or more. When it is 30% or more, the durability of the toner is improved.
Here, the primary hydroxylation rate of the PO adduct of bisphenol A may be calculated from, for example, NMR as the average functional group degree. The primary hydroxylation rate of the terminal hydroxyl group is calculated by measuring the sample in advance by pretreatment for esterification and then measuring by ¹ H-NMR method.

Details of the ¹ H-NMR method used in the present invention will be specifically described below.
<Sample Preparation Method> About 30 mg of a measurement sample is weighed into an NMR sample tube having a diameter of 5 mm, and about 0.5 ml of deuterated solvent is added and dissolved. Thereafter, about 0.1 ml of trifluoroacetic anhydride is added to obtain a sample for analysis. Examples of the deuterated solvent include deuterated chloroform, deuterated toluene, deuterated dimethyl sulfoxide, deuterated dimethylformamide, and the like, and a solvent capable of dissolving the sample is appropriately selected.
<NMR measurement> ¹ H-NMR measurement is performed under normal conditions.

<Calculation Method of Terminal Hydroxyl Group Primary Rate> By the pretreatment method described above, the hydroxyl group at the end of the PO adduct of bisphenol A reacts with the added trifluoroacetic anhydride to become a trifluoroacetic acid ester. As a result, a signal derived from a methylene group to which a primary hydroxyl group is bonded is observed at around 4.3 ppm, and a signal derived from a methine group to which a secondary hydroxyl group is bonded is observed at around 5.2 ppm. The primary hydroxylation rate of the terminal hydroxyl group is calculated by the following formula.
Terminal hydroxyl group primary ratio (%) = [a / (a + 2 × b)] × 100
In the formula, a is an integral value of a signal derived from a methylene group to which a primary hydroxyl group is bonded in the vicinity of 4.3 ppm; b is an integrated value of a signal derived from a methine group to which a secondary hydroxyl group is bonded in the vicinity of 5.2 ppm. .

The method for obtaining the PO adduct (a) of bisphenol A having a terminal primary hydroxyl group is not particularly limited, and examples thereof include a method of adding using a specific catalyst (α). In addition, when a basic catalyst (potassium hydroxide or the like) usually used for the production of a PO adduct is used as a catalyst, a PO adduct having a terminal secondary hydroxyl group and having substantially no primary hydroxyl group can be obtained. .
Examples of (α) include those described in JP-A No. 2000-344881, and specifically, boron or aluminum compounds (trifluoro) bonded with a fluorine atom, a (substituted) phenyl group and / or a tertiary alkyl group. Other than roborane), triphenylborane, diphenyl-t-butylborane, tri (t-butyl) borane, triphenylaluminum, diphenyl-t-butylaluminum, tri (t-butyl) aluminum, tris (pentafluorophenyl) Examples thereof include borane, bis (pentafluorophenyl) -t-butylborane, tris (pentafluorophenyl) aluminum, and bis (pentafluorophenyl) -t-butylaluminum.
Among these, preferred are triphenylborane, triphenylaluminum, tris (pentafluorophenyl) borane and tris (pentafluorophenyl) aluminum, and more preferred are tris (pentafluorophenyl) borane and tris (pentafluoro). Phenyl) aluminum.
(Α) is used at the time of PO addition, but it is not always necessary to use it at all stages of PO addition. After adding a part of PO in the presence of other commonly used catalysts described later, only (α) ) May be used to add the remaining PO.

Other catalysts include basic catalysts such as sodium hydroxide, potassium hydroxide, cesium hydroxide, potassium carbonate and triethylenediamine; acid catalysts such as boron trifluoride, tin chloride, triethylaluminum and heteropolyacid; zinc hexacyano Cobaltate; phosphazene compounds. Of these, basic catalysts are preferred.
The addition condition of PO may be the same as the method described in the above publication. For example, the catalyst is preferably 0.0001 to 10%, more preferably 0.001 to 1% with respect to the ring-opening polymer to be formed. [(Α) or other catalyst] is generally used at 0 to 250 ° C, preferably 20 to 180 ° C. In the above and the following, “%” means “% by weight” unless otherwise specified.

As a polyol component used in combination with the PO adduct (a) of bisphenol A having a primary hydroxyl group as necessary, a dihydric alcohol (diol) used for molecular extension of polyester and / or trivalent or higher used for molecular branching and crosslinking. Of polyhydric alcohols.
Examples of the diol include aliphatic diols having 2 to 36 carbon atoms (such as ethylene glycol, propylene glycol, and dodecane diol); polyalkylene ether glycols having 4 to 36 carbon atoms (such as diethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol). An alkylene oxide having 2 to 4 carbon atoms (hereinafter abbreviated as AO) [ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), butylene oxide, etc. ] Adduct (addition mole number 1.8-30); C6-C36 alicyclic diol (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); C2-C2 of the above alicyclic diol 4 AO adduct (1.8 moles added) 30); (a) other than bisphenols (bisphenol A, bisphenol F and the number 2 or 4 of AO adducts of carbon atoms of bisphenol S, etc.) (number of moles added 1.8 to 30), and the like.

  As the polyhydric alcohol having 3 to 8 or more valences, an aliphatic polyhydric alcohol having 3 to 8 or more carbon atoms having 3 to 36 carbon atoms (glycerin, triethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.) An AO adduct having 2 to 4 carbon atoms of the above aliphatic polyhydric alcohol (addition mole number 2.8 to 30); an AO adduct having 2 to 4 carbon atoms (addition moles) of trisphenols (such as trisphenol PA); 2.8-30); Novolak resins (phenol novolak, cresol novolak, etc .: average polymerization degree 3-60), C2-4 AO adduct (added mole number 2.8-30), and the like.

  Among the polyol components other than (a), preferably, an aliphatic diol having 2 to 36 carbon atoms, a polyalkylene ether glycol having 4 to 36 carbon atoms, an alicyclic diol, and an alicyclic having 6 to 36 carbon atoms. It is an AO adduct having 2 to 4 carbon atoms of a diol, an AO adduct having 2 to 4 carbon atoms of a bisphenol, and an AO adduct having 2 to 4 carbon atoms of a novolac resin, more preferably 2 to 4 carbon atoms. An EO adduct of bisphenols, and an AO (EO and / or PO) adduct of 2 to 3 carbon atoms of a novolak resin.

  The preferred weight ratio of the PO adduct (a) of bisphenol A in the polyol component is 40% or more, more preferably 45% or more, and particularly preferably 50% or more. When it is 40% or more, the charging stability is further improved.

  Examples of polycarboxylic acids include aliphatic (including alicyclic) and / or aromatic dicarboxylic acids used for molecular extension; tri- to hexa- or higher-valent aliphatic (alicyclic) used for molecular branching and crosslinking. (Including) a polycarboxylic acid and / or a tri- or hexavalent or higher aromatic polycarboxylic acid is preferably used in combination.

Aliphatic (including alicyclic) dicarboxylic acids include alkane dicarboxylic acids having 2 to 50 carbon atoms (such as oxalic acid, malonic acid, succinic acid, adipic acid, reparginic acid, and sebacic acid), and 4 to 50 carbon atoms. Alkene dicarboxylic acid (alkenyl succinic acid such as dodecenyl succinic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, and glutaconic acid).
Examples of the aromatic dicarboxylic acid include aromatic dicarboxylic acids having 8 to 36 carbon atoms (such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid).

Among the polycarboxylic acid components, trivalent to hexavalent or higher aliphatic (including alicyclic) polycarboxylic acids include aliphatic tricarboxylic acids having 6 to 36 carbon atoms (such as hexanetricarboxylic acid) and unsaturated carboxylic acids. Examples include acid vinyl polymers [number average molecular weight (hereinafter referred to as Mn, according to gel permeation chromatography (GPC)): 450 to 10,000] (α-olefin / maleic acid copolymer and the like).
Among the polycarboxylic acid components, trivalent to hexavalent or higher aromatic polycarboxylic acids include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid), and unsaturated carboxylic acids. Vinyl polymers [Mn: 450 to 10000] (such as styrene / maleic acid copolymer, styrene / acrylic acid copolymer, and styrene / fumaric acid copolymer).
These polycarboxylic acid anhydrides and lower alkyl (1 to 4 carbon atoms) esters (such as methyl esters) can also be used.

  Among these polycarboxylic acid components, preferred are alkane dicarboxylic acids having 2 to 50 carbon atoms, alkene dicarboxylic acids having 4 to 50 carbon atoms, aromatic dicarboxylic acids having 8 to 20 carbon atoms, and 9 to 20 carbon atoms. An aromatic polycarboxylic acid, more preferably adipic acid, alkenyl succinic acid having 16 to 50 carbon atoms, terephthalic acid, isophthalic acid, maleic acid, fumaric acid, trimellitic acid, pyromellitic acid, and combinations thereof Particularly preferred are fumaric acid, adipic acid, terephthalic acid, trimellitic acid, and combinations thereof. Likewise preferred are anhydrides and lower alkyl esters of these polycarboxylic acids.

  The polycarboxylic acid component preferably contains 60 mol% or more of an aromatic polycarboxylic acid (particularly terephthalic acid) from the viewpoint of the charging characteristics of the toner. More preferably, it is 70 mol% or more, Most preferably, it is 80 mol% or more.

  In the present invention, the polyester resin can be produced in the same manner as in an ordinary polyester production method. For example, the reaction can be carried out in an inert gas (nitrogen gas or the like) atmosphere at a reaction temperature of preferably 150 to 280 ° C, more preferably 160 to 260 ° C, particularly preferably 170 to 240 ° C. The reaction time is preferably 30 minutes or longer, particularly 2 to 40 hours from the viewpoint of reliably performing the polycondensation reaction.

At this time, an esterification catalyst may be used as necessary. Esterification catalysts include tin-containing catalysts (eg, dibutyltin oxide), antimony trioxide, titanium-containing catalysts (eg, titanium alkoxide, potassium oxalate titanate, and titanium terephthalate), zirconium-containing catalysts (eg, zirconyl acetate), and acetic acid Zinc etc. are mentioned. Among these, titanium-containing catalysts, zirconium-containing catalysts, and zinc acetate are preferable from the viewpoint of environmental safety, more preferably titanium-containing catalysts, and particularly preferably titanium alkoxide and potassium oxalate titanate. , And titanium terephthalate.
The amount of the catalyst added is desirably determined as appropriate so as to maximize the reaction rate. The addition amount is preferably 10 ppm to 1.9%, more preferably 100 ppm to 1.7%, based on the polyester resin obtained. It is preferable that the addition amount be 10 ppm or more because the reaction rate is increased.

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 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 component having a molecular weight of 500 or less in the tetrahydrofuran (THF) soluble component of the polyester resin of the present invention is preferably 0.6% or less from the viewpoint of durability. Moreover, 1000 to 20000 is preferable for the Mn of the THF-soluble component. The lower limit is more preferably 1200, particularly preferably 1400, and the upper limit is more preferably 14000, particularly preferably 12000. When Mn is 1000 to 20000, the balance between low-temperature fixability and resin grindability is improved.
Similarly, the peak top molecular weight of the polyester resin soluble in THF (hereinafter referred to as Mp) is preferably 1200 to 50000, more preferably from the viewpoint of the balance of resin strength, low-temperature fixability, and resin grindability. Is 1500-40000.

In the above and the following, the molecular weight and the like of the THF-soluble component of the polyester resin are measured using GPC under the following conditions.
Apparatus: HLC-8120 manufactured by Tosoh Corporation
Column: 2 TSK GEL GMH6 (manufactured by Tosoh Corporation)
Measurement temperature: 40 ° C
Sample solution: 0.25% THF solution Injection volume: 100 μl
Detector: Refractive index detector Reference substance: Standard polystyrene The molecular weight showing the maximum peak height on the obtained chromatogram is referred to as peak top molecular weight (Mp). Furthermore, the abundance ratio of low molecular weight substances is evaluated by the ratio of the peak areas when the molecular weight is divided by 500.

The glass transition point (Tg) of the polyester resin of the present invention is preferably 40 to 90 ° C., more preferably 45 to 85 ° C., and particularly preferably 50 to 80 ° C. from the viewpoints of heat resistant storage stability and low temperature fixability.
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.

The THF insoluble matter in the polyester resin of the present invention is preferably 70% or less from the viewpoint of low-temperature fixability. In the case of black and white toner application, the lower limit is more preferably 1%, particularly preferably 3%, and the upper limit is more preferably 40%, particularly preferably 30%. In the case of color toner use, the lower limit is more preferably 0%, and the upper limit is more preferably 15%, particularly preferably 10%.
The THF insoluble matter was 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.

  The toner composition of the present invention contains the polyester resin for toner of the present invention as a binder resin, a colorant, and, if necessary, one or more additives such as a release agent, a charge control agent, 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, Paranitaniline 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 polyester resin 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%, more preferably 40 to 95%, particularly preferably 45 to 92% of the polyester resin of the present invention based on the toner weight; Preferably 0.05 to 60%, more preferably 0.1 to 55%, particularly preferably 0.5 to 50%; Of the additives, the release agent is preferably 0 to 30%, more preferably 0. 0.5 to 20%, particularly preferably 1 to 10%; charge control agent is preferably 0 to 20%, more preferably 0.1 to 10%, particularly preferably 0.5 to 7.5%; fluidization The agent is preferably 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 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, then melt-kneaded, then coarsely pulverized, and finally atomized using a jet mill pulverizer or the like. Further, by further classifying, the particle size (D50) is preferably made into fine particles of 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 composition 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. Used as a developer for a latent image. 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.

  EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto.

A method for measuring the properties of the polyester resin for toner obtained in Examples and Comparative Examples is shown below.
1. Acid value and hydroxyl value Method defined in JIS K0070 (1992 edition).
When the sample had a solvent-insoluble component accompanying crosslinking, the sample after melt kneading was used as a sample by the following method.
Kneading device: Labo plast mill MODEL30R150 manufactured by Toyo Seiki Co., Ltd.
Kneading conditions: 30 minutes at 130 ° C. and 70 rpm Measurement of softening point Using a flow tester, the temperature was raised at a constant speed under the following conditions, and the temperature at which the outflow amount became 1/2 was taken as the softening point.
Device: Shimadzu Corporation flow tester CFT-500
Load: 20kg
Die: 1mmΦ-1mm
Temperature increase rate: 6 ° C./min.

Production Example 1
[Synthesis of PO Adduct of Primary Hydroxyl-Containing Bisphenol A]
In a SUS autoclave with a stirrer and a temperature controller, 581 parts of PO2 molar adduct of bisphenol A (Newpol BP-2P manufactured by Sanyo Chemical Industries, Ltd.) and 0.1 part of tris (pentafluorophenyl) borane were added. First, 108 parts of propylene oxide was added dropwise at a reaction temperature of 70 to 80 ° C. over 12 hours, followed by aging at 75 ° C. for 6 hours. Next, after neutralizing with an aqueous sodium hydroxide solution, 3.0 g of synthetic silicate (KYOWARD 600, manufactured by Kyowa Chemical Co., Ltd.) and water were added and treated at 60 ° C. for 3 hours. After taking out from the autoclave, it was filtered through a 1-micron filter and dehydrated to obtain a PO3.3 mol adduct (a1) of bisphenol A. The hydroxyl value of (a1) was 133.7, and the ^primary hydroxylation rate of the terminal hydroxyl group was determined from the measurement result of ¹ H-NMR chemical shift δ value (solvent: CDCl ₃ ) and found to be 74%.

Example 1
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 758 parts (11.5 mol) of bisphenol A · PO 3.3 mol adduct (a1) obtained in Production Example 1 and 243 parts of terephthalic acid ( 9.25 mol), 15 parts (0.5 mol) of trimellitic anhydride, and 3 parts of tetrabutoxy titanate as a condensation catalyst, and reacted for 5 hours while distilling off the generated water at 230 ° C. in a nitrogen stream. I let you. Next, the reaction was carried out under reduced pressure of 5 to 20 mmHg, and when the acid value reached 2, it was cooled to 180 ° C., 34 parts (1.1 mol) of trimellitic anhydride was added, and the reaction was taken out after 2 hours under normal pressure sealing. After cooling to room temperature, it was pulverized into particles. This is designated as polyester (1).
The glass transition temperature of (1) was 60 ° C., the acid value was 20, the hydroxyl value was 20, Mp was 7500, Mn was 4100, Mw was 18500, and the component having a molecular weight of 500 or less was 0.5%. The temperature at 10,000 Pa · s was 115 ° C., and the THF-insoluble content was 0%.
In addition, the number of moles in () is described to show the relative molar ratio of each raw material [the same applies hereinafter].

Example 2
Addition of 415 parts (21.0 mol) of 1,2-propylene glycol (hereinafter simply referred to as propylene glycol) and 3.3 mol of bisphenol A / PO in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube 541 parts (5.0 moles) of the product (a1), 442 parts (8.75 moles) of dimethyl terephthalate, 19 parts (0.5 moles) of adipic acid, 25 parts (0.5 moles) of trimellitic anhydride, Then, 3 parts of tetrabutoxy titanate was added as a condensation catalyst, and the mixture was reacted at 180 ° C. for 8 hours while distilling off the produced methanol under a nitrogen stream. Next, while gradually raising the temperature to 230 ° C., the reaction was performed for 4 hours while distilling off propylene glycol and water produced under a nitrogen stream, and further, the reaction was performed for 1 hour under a reduced pressure of 5 to 20 mmHg. The recovered propylene glycol was 297 parts (15.0 mol). Subsequently, it cooled to 180 degreeC, 35 parts (0.7 mol) of trimellitic anhydride was added, it took out after reaction for 2 hours under normal pressure sealing, cooled to room temperature, pulverized and granulated. This is designated as polyester (2).
The glass transition temperature of (2) was 60 ° C., the acid value was 20, the hydroxyl value was 22, Mp was 6500, Mn was 3800, Mw was 15500, and the component having a molecular weight of 500 or less was 0.3%. The temperature at 10,000 Pa · s was 116 ° C., and the THF-insoluble content was 0%.

Comparative Example 1
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 728 parts (11.5 mol) of bisphenol A · PO 2.0 mol adduct (primary hydroxylation rate = 0.04%), terephthalic acid 279 1 part (9.25 mol), trimellitic anhydride 17 parts (0.5 mol), and 3 parts of titanium terephthalate as a condensation catalyst were added under a nitrogen stream at 230 ° C. while distilling off the generated water. Reacted for hours. Next, the reaction was carried out under reduced pressure of 5 to 20 mmHg. When the acid value reached 2, the mixture was cooled to 180 ° C., 27 parts (1.0 mol) of trimellitic anhydride was added, and the reaction was taken out for 2 hours under atmospheric pressure and sealed. After cooling to room temperature, it was pulverized into particles. This is designated as polyester (3).
The glass transition temperature of (3) was 74 ° C., the acid value was 16, the hydroxyl value was 19, Mp was 6700, Mn was 4600, Mw was 18800, and the component having a molecular weight of 500 or less was 1.1%. Further, the temperature at 10,000 Pa · s was 121 ° C., and the THF insoluble content was 0%.

Example 3
To 100 parts of each of the polyester resins (1) and (2) of the present invention and the comparative polyester resin (3), 8 parts of cyanine blue KRO (manufactured by Sanyo Dye) and 5 parts of carnauba wax are added to form a toner by the following method did.
First, after pre-mixing using a Henschel mixer [FM10B manufactured by Mitsui Miike Chemical Co., Ltd.], the mixture was kneaded using a biaxial kneader [PCM-30 manufactured by Ikegai Co., Ltd.]. Then, after finely pulverizing using a supersonic jet pulverizer Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], it is classified by an airflow classifier [MDS-I made by Nippon Pneumatic Industry Co., Ltd.] 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) in a sample mill to obtain toners (T1), (T2) and comparative toner (T3) of the present invention. .
The evaluation results evaluated by the following evaluation methods are shown in Table 1.

  From the results in Table 1, it can be seen that the toner of the present invention has the same or better range of charging from MFT to HOT and superior durability compared to the comparative toner.

[Evaluation methods]
30 parts of toner and 800 parts of ferrite carrier (powdertech, f-150) were uniformly mixed to obtain a two-component developer, and the following evaluation was performed.
[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 fixing roll temperature at which the residual ratio of the image density after rubbing the fixed image with a pad becomes 70% or more was set 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 fixing roll temperature at which hot offset occurred was defined as the hot offset occurrence temperature.
[3] Measurement of saturation charge amount and evaluation of rise of charge amount H. After adjusting the humidity for 8 hours or more, the mixture was frictionally stirred at 50 rpm × 1, 3, 7, 20, 60 and 120 minutes with a tumbler shaker mixer, and the charge amount was measured at each time. For the measurement, a blow-off charge measuring device [manufactured by Toshiba Chemical Co., Ltd.] was used. The amount of charge at the friction time when the increase in charge amount ceased was taken as the saturation charge amount.
The evaluation criteria for the rise of the charge amount were evaluated according to the following criteria based on the charge amount measurement result.
A: Friction time to reach 80% of the charge amount of saturation is less than 7 minutes B: Friction time to reach the charge amount of 80% of the saturation charge is from 7 minutes to less than 20 minutes C: Saturation The friction time to reach 80% of the charge amount is 20 minutes or more and less than 60 minutes D: The friction time to reach the charge amount of 80% of the saturation charge amount is 60 minutes or more [4] Continuous copying test Using the developer, an unfixed image developed using a commercial copying machine [AR5030, manufactured by Sharp Corporation] is used with a fixing unit of a commercially available full color copying machine [LBP-2160, manufactured by Canon Inc.]. Fixing was performed at a process speed of 80 mm / sec.
Evaluation criteria A: Image is good even after 8000 sheets are continuously copied B: Image quality is slightly deteriorated after 8000 sheets are continuously copied C: Image quality is clearly decreased after 8000 sheets are continuously copied D: From the beginning of copying Image defect

  Since the toner of the present invention using the polyester resin of the present invention has excellent charging characteristics and excellent durability, it is useful as a toner for developing an electrostatic image, particularly a color toner.

Claims (8)

In a polyester resin for toner obtained by polycondensation of a polyol component and a polycarboxylic acid component, a propylene oxide adduct of bisphenol A in which at least a part of the polyol component has 30 to 100 mol% primary hydroxyl groups in the terminal hydroxyl groups ( A toner composition comprising a toner polyester resin and a colorant essential as a), and optionally comprising at least one additive selected from a mold release agent, a charge control agent, and a fluidizing agent. 2. The toner composition according to claim 1, wherein the weight ratio of the propylene oxide adduct of bisphenol A (a) in the polyol component of the polyester resin for toner is 40% by weight or more. The propylene oxide adduct (a) of bisphenol A is a boron compound (other than trifluoroborane) bonded with a fluorine atom and / or a (substituted) phenyl group and / or a tertiary alkyl group, and a fluorine atom and / or (substituted) 3. The toner composition according to claim 1, wherein the toner composition is obtained by adding propylene oxide using a catalyst (α) selected from an aluminum compound having a phenyl group and / or a tertiary alkyl group bonded thereto. The toner composition according to any one of claims 1 to 3, wherein the propylene oxide average addition mole number of the propylene oxide adduct (a) of bisphenol A is 2.8 to 5.2. The toner composition according to claim 1, wherein the polyester resin for toner is polycondensed in the presence of a titanium-containing catalyst. The toner composition according to any one of claims 1 to 5, wherein the polyester resin for toner has a tetrahydrofuran-soluble component having a number average molecular weight of 1,000 to 20,000. The toner composition according to any one of claims 1 to 6, wherein the polycarboxylic acid component of the polyester resin for toner comprises 60 mol% or more of aromatic polycarboxylic acid. The toner composition according to claim 1, which is used for color.