JP2008122931A - Resin for toner and toner composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner composition excellent in low-temperature fixability and blocking resistance, and a resin for toner used in the same. <P>SOLUTION: The resin for toner comprises a polyester resin (A) comprising a linear polyester (A1) and a nonlinear polyester (A2), wherein an acid number of the linear polyester (A1) is 50-200 mgKOH/g and a glass transition temperature Tg(°C) and a flow softening point Tm(°C) of the linear polyester (A1) satisfy the relationship of Tm-Tg≤38(°C). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

It is conventionally known to use a polyester resin as a binder for the purpose of improving the low-temperature fixing performance of the toner. In addition, for the purpose of improving fixability, a method of containing a high acid value polyester resin has been proposed (Patent Document 1, etc.).
JP 2004-294735 A

However, in recent years, the demand for fixing at a lower temperature has been increased due to the demand for reducing the environmental load, and a resin that has both blocking resistance and low-temperature fixability has been demanded.
An object of the present invention is to provide a toner composition further excellent in low-temperature fixability and blocking resistance, and a toner resin used therefor.

  As a result of intensive studies to solve the above problems, the present inventors have reached the present invention. That is, this invention consists of the polyester resin (A) which consists of linear polyester (A1) and nonlinear polyester (A2), the acid value of (A1) is 50-200 mgKOH / g, and the glass transition temperature of (A1) [ Tg] (° C.) and flow softening point [Tm] (° C.) satisfy the relationship of [Tm] − [Tg] ≦ 38 (° C.); and the toner resin and colorant And, if necessary, a toner composition comprising one or more additives selected from a release agent, a charge control agent, and a flow agent.

  By using the toner resin of the present invention, a toner having excellent low-temperature fixability and hot offset resistance (fixing temperature range) can be obtained, and the toner has good blocking resistance.

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

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

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

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

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

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

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

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

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

  The linear polyester (A1) can be obtained, for example, by polycondensation of the diol (x1) and the dicarboxylic acid (y1). It may be modified with a good anhydride. In these, what modified | denatured the molecular terminal with the anhydride of (y) is preferable. The reaction ratio between the polyol component and the polycarboxylic acid component is preferably 3/1 to 1/3, more preferably 2.5 / 1 to 1/1 / as the equivalent ratio [OH] / [COOH] of the hydroxyl group to the carboxyl group. 2.5, particularly preferably 2/1 to 1/2.

The acid value of the linear polyester (A1) used in the present invention is 50 to 200 (mg KOH / g, the same applies hereinafter). The acid value is preferably 55 to 180, more preferably 60 to 160. When the acid value is less than 50, the low-temperature fixability is insufficient, and when it exceeds 200, the charging characteristics are deteriorated.
The acid value in the present invention is measured by a method specified in JIS K0070.

(A1) has a difference ([Tm] − [Tg]) between the flow softening point [Tm] (° C.) and the glass transition temperature [Tg] (° C.) of 38 ° C. or less. ([Tm] − [Tg]) is preferably 35 ° C. or lower, more preferably 32 ° C. or lower. When ([Tm] − [Tg]) exceeds 38 ° C., the low-temperature fixability deteriorates.
([Tm]-[Tg]) can be adjusted to 38 ° C. or lower by reducing the molecular weight, lowering [Tm], increasing the acid value, etc. (bonds other than covalent bonds (hydrogen bonds, intermolecular forces) Etc.) in which [Tg] is increased without increasing [Tm], crystalline plasticizer (stearic acid, magnesium stearate, etc.) is added, and [Tm] is decreased without decreasing [Tg]. It is done.

The glass transition temperature [Tg] of (A1) is preferably 45 ° C to 75 ° C, more preferably 50 ° C to 70 ° C. When [Tg] is 75 ° C. or lower, the low-temperature fixability is improved. Further, when [Tg] is 45 ° C. or higher, the blocking resistance is good.
Further, the flow softening point [Tm] of (A1) is not particularly limited as long as it satisfies the above relationship ([Tm]-[Tg]), but is preferably 70 ° C to 120 ° C, more preferably. 75 ° C to 100 ° C. When [Tm] is 70 ° C. or higher, the hot offset resistance is good, and when it is 120 ° C. or lower, the fixability is good.

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

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

The hydroxyl value of (A1) is preferably 25 to 125 (mg KOH / g, the same shall apply hereinafter), more preferably 30 to 100. When the hydroxyl value is 25 or more, the compatibility with (A2) is good, and the glossiness (gloss) after fixing is good. Further, when the hydroxyl value is 125 or less, the resistance to hot offset becomes better.
The hydroxyl value in the present invention is measured by a method specified in JIS K0070.
In order to set the acid value and hydroxyl value of (A1) within the above ranges, it is effective to adjust the reaction ratio between the polyol component (x) and the polycarboxylic acid component (y).

The number average molecular weight (hereinafter referred to as Mn) of the tetrahydrofuran (THF) soluble portion of the linear polyester (A1) used in the present invention is preferably 500 to 4000, more preferably 800 to 3000, and particularly preferably 1100 to 2800. It is. When Mn is 500 or more, the resin strength necessary for fixing is expressed, and when it is 4000 or less, the low-temperature fixability is good.
The peak-top molecular weight (hereinafter referred to as Mp) of the THF-soluble component of (A1) is preferably 1000 to 7000, more preferably from the viewpoint of the balance of resin strength, low-temperature fixability, and resin grindability. 1200-5000.

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

The THF insoluble content in the linear polyester (A1) is preferably 5% or less from the viewpoint of low-temperature fixability. More preferably, it is 4% or less, and particularly preferably 3% or less. In the above and the following, “%” means “% by weight” unless otherwise specified.
The THF-insoluble matter in the present invention is determined by the following method.
Add 50 ml of THF to 0.5 g of the sample and stir to reflux for 3 hours. After cooling, the insoluble content is filtered off with a glass filter, and the resin content on the glass filter is dried under reduced pressure at 80 ° C. for 3 hours. The insoluble matter is calculated from the weight of the dried resin content on the glass filter and the weight ratio of the sample. In addition, this filtrate is used for GPC measurement as a THF soluble part.

  The non-linear polyester (A2) used in the present invention is usually the above-mentioned dicarboxylic acid (y1) and diol (x1) together with the above-mentioned 3-6 or higher polycarboxylic acid (y2) and / or trivalent-8 octavalent. Alternatively, it can be obtained by reacting more polyol (x2). The reaction ratio between the polyol component and the polycarboxylic acid component is preferably 2/1 to 1/2, more preferably 1.5 / 1 to 1/1 / as the equivalent ratio [OH] / [COOH] of the hydroxyl group to the carboxyl group. 1.3, particularly preferably 1.3 / 1 to 1 / 1.2.

  The ratio of (y2) and (x2) in the case of obtaining (A2) is preferably such that the sum of the number of moles is the sum of the number of moles of all polyol components (x) and polycarboxylic acid components (y). Is from 0.1 to 40 mol%, more preferably from 1 to 25 mol%, particularly preferably from 3 to 20 mol%.

The glass transition temperature [Tg] of (A2) is preferably 45 ° C to 75 ° C, more preferably 50 ° C to 70 ° C. When [Tg] is 75 ° C. or lower, the low-temperature fixability is improved. Further, when [Tg] is 45 ° C. or higher, the blocking resistance is good.
The flow softening point [Tm] of (A2) is not particularly limited, but is preferably 100 ° C to 180 ° C, more preferably 120 ° C to 170 ° C. When [Tm] is 100 ° C. or higher, the hot offset resistance is good, and when it is 180 ° C. or lower, the fixability is good.

Mn of the THF soluble part of the non-linear polyester (A2) is preferably 2000 to 9500, and more preferably 2500 to 9000. When Mn is 2000 or more, the resin strength necessary for fixing is expressed, and when it is 9500 or less, the low-temperature fixing property and the resin grindability are good.
Moreover, Mp of the THF soluble part of (A2) is preferably 2000 to 50000, more preferably 2500 to 30000, from the viewpoint of the balance of resin strength, low-temperature fixability, and resin grindability.

  The THF insoluble matter in the non-linear polyester (A2) is preferably 3 to 50% from the viewpoint of low-temperature fixability. More preferably, it is 5 to 40%, and particularly preferably 10 to 35%. When the THF-insoluble content is 50% or less, the glossiness (gloss) of the image is good.

The acid value of the non-linear polyester (A2) is preferably 10 to 70, more preferably 15 to 60, and particularly preferably 16 to 50. When the acid value is 10 or more, the difference between the flow softening point [Tm] (° C.) and the glass transition temperature [Tg] (° C.) of (A1) and the melt-kneaded polyester resin (A) ([Tm] − [Tg] ) Is small, and both low-temperature fixability and blocking resistance can be achieved. When the acid value is 70 or less, the charging characteristics are good.
Moreover, the hydroxyl value of (A2) is preferably 0 to 50, more preferably 0 to 45, and particularly preferably 0 to 40. When the hydroxyl value is 50 or less, the hot offset resistance becomes better.

  The weight ratio [(A1) / (A2)] of the linear polyester (A1) to the non-linear polyester (A2) in the polyester resin (A) used for the resin for toner of the present invention is low temperature fixability, hot offset resistance and pulverization. From the viewpoint of compatibility, the ratio is preferably 10/90 to 80/20, more preferably 20/80 to 75/25, and particularly preferably 25/75 to 70/30.

  The toner resin of the present invention may contain, in addition to the polyester resin (A), other resins usually used as a toner resin as long as the properties thereof are not impaired. Examples of other resins include polyester resins other than (A1) and (A2) with Mn of 1,000 to 1,000,000, styrene resins, resins having a structure in which a vinyl resin is grafted on a polyolefin resin, epoxy resins, and polyurethane resins. Can be mentioned. Other resins may be blended with (A1) and (A2) or may be partially reacted. The content of other resins is preferably 10% or less, more preferably 5% or less.

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

  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 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 from 30 to 97%, more preferably from 40 to 95%, particularly preferably from 45 to 92%, based on the toner weight, the toner resin of the present invention; , Preferably 0.05 to 60%, more preferably 0.1 to 55%, particularly preferably 0.5 to 50%; among additives, a release agent is preferably 0 to 30%, more preferably 0.5-20%, particularly preferably 1-10%; charge control agent is preferably 0-20%, more preferably 0.1-10%, particularly preferably 0.5-7.5%; flow The agent is preferably 0 to 10%, more preferably 0 to 5%, particularly preferably 0.1 to 4%. The total content of the 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, and then melt-kneaded, then coarsely pulverized, and finally atomized using a jet mill pulverizer or the like. Further, by further classifying, the volume average particle diameter (D50) is preferably 5 to 20 μm and then mixed with a fluidizing agent. The particle size (D50) is measured using a Coulter counter [for example, trade name: Multisizer III (manufactured by Coulter)].
When the toner is obtained by the emulsion phase inversion method, the components constituting the toner excluding the fluidizing agent are dissolved or dispersed in an organic solvent, and then emulsified by adding water, etc., and then separated and classified. it can. The volume average particle diameter of the toner is preferably 3 to 15 μm.

  The toner 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. Hereinafter, a part shows a weight part.

A method for measuring the properties of the resin obtained in the production example is shown below. Measurement methods other than the following are based on the above methods.
1. Glass transition temperature [Tg]
The method defined in ASTM D3418-82 (DSC method).
Apparatus: Seiko Electronics Co., Ltd. DSC20, SSC / 580
2. Tetrahydrofuran (THF) insoluble matter 50 ml of THF is added to 0.5 g of a sample, and the mixture is stirred and refluxed 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 was calculated from the weight of the resin content on the glass filter and the weight ratio of the sample.
3. Flow softening point [Tm]
Using a flow tester, the temperature was raised at a constant speed under the following conditions, and the temperature at which the outflow amount was halved was defined as the softening point.
Apparatus: Flow tester CFT-500D manufactured by Shimadzu Corporation
Load: 20kg
Die: 1mmΦ-1mm
Temperature increase rate: 6 ° C./min.

Production Example 1 <Synthesis of Linear Polyester>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 2280 parts (30 mol) of 1,2-propylene glycol (hereinafter simply referred to as propylene glycol), 1940 parts (10 mol) of dimethyl terephthalate And 3 parts of tetrabutoxy titanate as a condensation catalyst were allowed to react at 180 ° C. for 8 hours while distilling off the methanol produced under a nitrogen stream. Next, while the temperature was gradually raised to 230 ° C., the reaction was carried out while distilling off propylene glycol produced under a nitrogen stream, and cooling was performed when the softening point reached 45 ° C. When the temperature reached 180 ° C., 787 parts (4.1 mol) of trimellitic anhydride was charged, held at 180 ° C. for 1 hour, and then taken out. The taken out resin was cooled to room temperature and then pulverized into particles. This is designated as linear polyester (A1-1).
The linear polyester (A1-1) has a Tg of 54 ° C., a Tm of 85 ° C. (Tm-Tg: 31 ° C.), an Mp of 2000, an Mn of 1100, an acid value of 140, a hydroxyl value of 81, and a THF insoluble content of 0. %Met. The number of moles in () means a relative molar ratio. (The same applies hereinafter)

Production Example 2 <Synthesis of Linear Polyester>
Bisphenol A / propylene oxide (hereinafter referred to as PO) 3 mol adduct 6834 parts (17 mol), terephthalic acid 1660 parts (10 mol), and condensation in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube 3 parts of tetrabutoxy titanate was added as a catalyst, and the reaction was carried out at 230 ° C. under a nitrogen stream for 5 hours while distilling off the generated water. Next, the reaction was carried out under a reduced pressure of 5 to 20 mmHg. When the acid value became 2 or less, the mixture was cooled to 180 ° C., 1325 parts (6.9 mol) of trimellitic anhydride was added, and the reaction was performed for 1 hour under normal pressure sealing. After taking out and cooling to room temperature, it was pulverized into particles. This is designated as linear polyester (A1-2).
The linear polyester (A1-2) has a Tg of 61 ° C., a Tm of 93 ° C. (Tm-Tg: 32 ° C.), an Mp of 3500, an Mn of 1800, an acid value of 90, a hydroxyl value of 45, and a THF insoluble content of 0. %Met.

Production Example 3 <Synthesis of Linear Polyester>
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen introduction tube, 5916 parts (17 moles) of bisphenol A / PO2 mole adduct, 1577 parts (9.5 moles) of terephthalic acid, 83 parts of isophthalic acid (0.5 parts) Mol) and 3 parts of bistriethanolamine titanate as a condensation catalyst were allowed to react at 230 ° C. in a nitrogen stream while distilling off the water produced. Next, the reaction was carried out under reduced pressure of 5 to 20 mmHg, and when the acid value became 2 or less, the mixture was cooled to 180 ° C., added with 826 parts (4.3 mol) of trimellitic anhydride, and reacted for 1 hour under sealed atmosphere. After taking out and cooling to room temperature, it was pulverized into particles. This is designated as linear polyester (A1-3).
The linear polyester (A1-3) has a Tg of 61 ° C., a Tm of 96 ° C. (Tm-Tg: 35 ° C.), an Mp of 2900, an Mn of 1200, an acid value of 60, a hydroxyl value of 79, and a THF insoluble content of 0. %Met.

Production Example 4 <Synthesis of Nonlinear Polyester>
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen introduction tube, 2280 parts (30 moles) of propylene glycol, 1649 parts (8.5 moles) of dimethyl terephthalate, 219 parts (1.5 moles) of adipic acid, Then, 3 parts of tetrabutoxy titanate was added as a condensation catalyst, and the reaction was allowed to proceed for 8 hours at 180 ° C. while distilling off the methanol produced under a nitrogen stream. Next, while gradually raising the temperature up to 230 ° C., propylene glycol produced in a nitrogen stream and water were allowed to react for 4 hours while distilling off water, and the reaction was further carried out under reduced pressure of 5 to 20 mmHg, and the softening point was 90 ° C. At that time, it was cooled to 180 ° C., 115 parts (0.6 mol) of trimellitic anhydride was added, and the reaction was conducted for 2 hours under sealed at atmospheric pressure, followed by reaction under reduced pressure of 220 ° C. and 5-20 mmHg, and the softening point was 155 ° C. When it became, it took out. The taken out resin was cooled to room temperature and then pulverized into particles. This is designated as nonlinear polyester (A2-1).
The nonlinear polyester (A2-1) had a Tg of 60 ° C., a Tm of 155 ° C., an Mp of 9000, an Mn of 7000, an acid value of 23, a hydroxyl value of 2, and a THF insoluble content of 20%.

Production Example 5 <Synthesis of Nonlinear Polyester>
5025 parts (12.5 moles) of bisphenol A · PO3 mole adduct, 1527 parts (9.2 moles) of terephthalic acid, 93 parts (0.8 moles) of fumaric acid, and 3 parts of tetrabutoxy titanate as a condensation catalyst, The reaction was carried out for 5 hours at 230 ° C. while distilling off the water produced under a nitrogen stream. Next, the reaction was carried out under reduced pressure of 5 to 20 mmHg. When the acid value became 2 or less, the mixture was cooled to 180 ° C., added with 250 parts (1.3 mol) of trimellitic anhydride, and reacted for 2 hours under sealed atmosphere. The reaction was carried out under reduced pressure of 230 ° C. and 5-20 mmHg, and the sample was taken out when the softening point reached 140 ° C. The taken out resin was cooled to room temperature and then pulverized into particles. This is designated as nonlinear polyester (A2-2).
The nonlinear polyester (A2-2) had a Tg of 57 ° C., a Tm of 145 ° C., an Mp of 8300, an Mn of 6200, an acid value of 16, a hydroxyl value of 24, and a THF insoluble content of 30%.

Comparative Production Example 1 <Synthesis of Linear Polyester>
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen introduction tube, 2280 parts (30 moles) of propylene glycol, 1940 parts (10 moles) of dimethyl terephthalate, and 3 parts of tetrabutoxy titanate as a condensation catalyst were added. The reaction was carried out for 8 hours while distilling off the methanol produced under nitrogen flow at ℃. Next, while the temperature was gradually raised to 230 ° C., the reaction was carried out while distilling off propylene glycol produced under a nitrogen stream, and the mixture was taken out when the softening point reached 95 ° C. The taken out resin was cooled to room temperature and then pulverized into particles. This is designated as linear polyester (A1′-1).
The linear polyester (A1′-1) has a Tg of 59 ° C., Tm of 96 ° C. (Tm-Tg: 37 ° C.), Mp of 4000, Mn of 1700, acid value of 2, hydroxyl value of 60, THF insoluble matter 0%.

Comparative Production Example 2 <Synthesis of Linear Polyester>
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet tube, 2280 parts (30 moles) of propylene glycol, 1940 parts (10 moles) of dimethyl terephthalate, and 3 parts of tetrabutoxy titanate as a condensation catalyst were added. The reaction was allowed to proceed for 8 hours while distilling off the methanol produced under nitrogen flow at ℃. Next, while the temperature was gradually raised to 230 ° C., the reaction was carried out while distilling off propylene glycol produced under a nitrogen stream, and the mixture was cooled when the softening point reached 45 ° C. When the temperature reached 180 ° C., 1498 parts (7.8 mol) of trimellitic anhydride was charged, held at 180 ° C. for 1 hour, and then taken out. The taken-out resin was cooled to room temperature and then pulverized into particles. This is designated as linear polyester (A1′-2).
Tg of linear polyester (A1′-2) is 63 ° C., Tm is 98 ° C. (Tm-Tg: 35 ° C.), Mp is 3000, Mn is 1200, acid value is 210, hydroxyl value is 78, THF insoluble matter is 0%.

Comparative Production Example 3 <Synthesis of Linear Polyester>
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen introduction tube, 2280 parts (30 moles) of propylene glycol, 1940 parts (10 moles) of dimethyl terephthalate, and 3 parts of tetrabutoxy titanate as a condensation catalyst were added. The reaction was carried out for 8 hours while distilling off the methanol produced under nitrogen flow at ℃. Next, while the temperature was gradually raised to 230 ° C., the reaction was carried out while distilling off propylene glycol produced under a nitrogen stream, and the mixture was cooled when the softening point reached 55 ° C. When the temperature reached 180 ° C., 562 parts (2.9 mol) of trimellitic anhydride was charged, held at 180 ° C. for 1 hour, and then taken out. The taken out resin was cooled to room temperature and then pulverized into particles. This is designated as linear polyester (A1′-3).
Tg of linear polyester (A1′-3) is 48 ° C., Tm is 89 ° C. (Tm-Tg: 41 ° C.), Mp is 2300, Mn is 900, acid value is 85, hydroxyl value is 90, and THF insoluble matter is 0%.

Production Examples 6 to 12 <Preparation of Resin for Toner>
The linear polyester (A1) and the non-linear polyester (A2) were melt-mixed with a continuous kneader at a jacket temperature of 130 ° C. and a residence time of 3 minutes at the mixing ratio shown in Table 1. The molten resin was cooled to room temperature, then pulverized by a pulverizer and formed into particles to obtain toner resins (C-1) to (C-7) of the present invention.

Comparative Production Examples 4 to 6 <Production of Comparative Toner Resin>
At a blending ratio shown in Table 1, linear polyester and nonlinear polyester were melt-mixed with a continuous kneader at a jacket temperature of 130 ° C. and a residence time of 3 minutes. After the molten resin was cooled to room temperature, it was pulverized by a pulverizer and formed into particles to obtain comparative toner resins (C′-1) to (C′-3).

Examples 1-7 and Comparative Examples 1-3
Cyanine blue KRO (Sanyo) with respect to 100 parts of each of the toner resins (C-1) to (C-7) and the comparative toner resins (C′-1) to (C′-3) of the present invention. 8 parts of pigment) and 5 parts of carnauba wax were added to form a toner by the following method.
First, after premixing 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 crusher lab jet [manufactured by Nippon Pneumatic Industry Co., Ltd.], it is classified by an airflow classifier [MDS-I manufactured by Nippon Pneumatic Industry Co., Ltd.], and the particle size D50 is 8 μm toner particles were obtained. Next, 100 parts of the toner particles were mixed with 0.5 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil Co., Ltd.) using a sample mill, and the toner compositions (T-1) to (T-7) of the present invention and comparison were made. Toner compositions (T′-1) to (T′-3) were obtained.
The evaluation results evaluated by the following evaluation methods are shown in Table 1.

[Evaluation methods]
[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] Blocking resistance 10.0 g of the sample was placed in a 200 ml polycup and left standing in a circulating dryer at 40 ° C. After 5 days, the sample was taken out from the dryer, and the fluidity of the sample was confirmed.
(Judgment)
A: Flows when the cup is tilted.
○: It flows when the cup is tilted and patted with a spatula.
Δ: Flows when the cup is tilted and pucked strongly with a spatula.
X: The cup does not flow even when tilted and spatula strongly.
A judgment of ◯ or more is judged to have good blocking resistance.

  As described above, the toner compositions (Examples 1 to 7) of the present invention using the toner resin of the present invention are all significantly better than the toner compositions of the comparative examples using the comparative toner resin. Results were obtained.

  The toner composition of the present invention using the resin for toner of the present invention is useful as an electrostatic charge image developing toner excellent in low-temperature fixability, hot offset resistance, and blocking resistance, particularly a color toner.

Claims (5)

  It comprises a polyester resin (A) composed of a linear polyester (A1) and a non-linear polyester (A2), the acid value of (A1) is 50 to 200 mgKOH / g, and the glass transition temperature [Tg] (° C.) of (A1) A toner resin, wherein a flow softening point [Tm] (° C.) satisfies a relationship of [Tm] − [Tg] ≦ 38 (° C.).   The resin for toner according to claim 1, wherein the glass transition temperature [Tg] of (A1) is 45 to 75 ° C. and the hydroxyl value is 25 to 125 mgKOH / g.   3. The resin for toner according to claim 1, wherein the tetrahydrofuran (THF) insoluble matter of (A2) is 3 to 50% by weight.   The resin for toner according to claim 1, wherein the weight ratio of (A1) to (A2) is 10/90 to 80/20.   A toner composition comprising the toner resin according to claim 1, a colorant, and, if necessary, one or more additives selected from a release agent, a charge control agent, and a fluidizing agent.