JP6227571B2 - Toner binder and toner composition - Google Patents

Description

  The present invention relates to a toner composition and a toner binder used for developing an electrostatic charge image or a magnetic latent image in electrophotography, electrostatic recording method, electrostatic printing method and the like.

  In recent years, with the development of electrophotographic systems, the demand for electrophotographic apparatuses such as copiers and laser printers is rapidly increasing, and the demands for their performance are also increasing. In general, in an electrophotographic system, an electrostatic charge image (latent image) is formed on a photoreceptor, and then the latent image is developed using toner to form a toner image. The toner image is transferred onto a recording medium such as paper and then fixed by a method such as heating.

From the viewpoint of energy saving, that is, reduction in energy consumption in the fixing process as well as promotion of miniaturization, high speed and high image quality of the electrophotographic apparatus, improvement of low temperature fixing property of toner is strongly demanded.
As a means for lowering the toner fixing temperature, a technique for lowering the glass transition point of the binder resin is generally used. However, if the glass transition point is too low, powder aggregation (blocking) is likely to occur and toner storage stability is lowered, so the lower limit of the glass transition point is practically 50 ° C. This glass transition point is a design point of the binder resin, and a toner that can be fixed at a lower temperature cannot be obtained by a method of lowering the glass transition point.
Another means is to reduce the molecular weight. However, if the molecular weight is too small, when the toner image is fixed by the hot roll fixing method, the hot roll and the molten toner are in direct contact at the time of fixing. There is a drawback that a so-called offset phenomenon is likely to occur which pollutes the transferred transfer paper or the like.

As a means for solving such a problem, for example, Patent Document 1 proposes a toner composed of a vinyl polymer that is appropriately crosslinked using a crosslinking agent and a molecular weight regulator. Document 2) proposes a toner having a wide molecular weight distribution so that the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 3.5 to 40. Certainly, although these toners expand the fixable range, that is, the temperature range between the offset generation temperature and the minimum fixing temperature, compared with the conventional uncrosslinked single resin having a narrow molecular weight distribution, it is still not sufficient.

On the other hand, a toner using a reaction product of a mixture of a polymerizing resin and a polyester resin and an isocyanate has been proposed. (Patent Documents 3 to 11)
However, even with this method, even if the offset phenomenon at high temperature can be prevented to some extent, the lower limit fixing temperature also rises at the same time, so that low-temperature fixing becomes difficult, and the demands for speeding up and energy saving have not yet been fully met.

Japanese Patent Publication No.51-2334 Japanese Patent Publication No.55-6805 JP-A 63-56659 Japanese Patent Laid-Open No. 1-154068 Japanese Patent Laid-Open No. 2-166464 JP-A-2-308175 JP-A-4-211272 JP 11-282203 A Japanese Patent Laid-Open No. 11-305481 JP 2000-234011 A JP 2004-258627 A

The present invention provides a toner having excellent fluidity, heat-resistant storage stability, charge stability, pulverization property, image strength, folding resistance and document offset property while maintaining both low-temperature fixability, glossiness and hot offset resistance. An object is to provide a binder and a toner composition.

As a result of intensive studies to solve these problems, the present inventors have reached the present invention.
That is, the present invention relates to a melt mixture of an amorphous polyester resin (A) having a glass transition temperature of −35 ° C. or higher and lower than 45 ° C. and an amorphous polyester resin (B) having a glass transition temperature of 45 ° C. or higher and 80 ° C. or lower. A toner binder comprising a resin composition (C) obtained by mixing and reacting (D) and satisfying the following relational expressions (1) and (2); A toner composition containing a binder and a colorant.

0.02 ≦ X ₁ ≦ 0.08 (1)
0.10 ≦ X ₀ / X ₁ ≦ 0.90 (2)
[X ₀ in the relational expression represents an average crosslinking density of the polyester resin (A) and the polyester resin (B), and X ₁ represents an average crosslinking density of the resin composition (C). ]

According to the present invention, a toner excellent in fluidity, heat-resistant storage stability, charge stability, pulverization property, image strength, folding resistance and document offset property while maintaining both low-temperature fixability, glossiness and hot offset resistance. It has become possible to provide binder and toner compositions.

Hereinafter, the toner binder of the present invention will be described.
The toner binder of the present invention comprises a molten mixture of an amorphous polyester resin (A) having a glass transition temperature of −35 ° C. or higher and lower than 45 ° C. and an amorphous polyester resin (B) having a glass transition temperature of 45 ° C. or higher and 80 ° C. or lower. The resin composition (C) obtained by mixing and reacting the extender (D) is contained, and the following relational expressions (1) and (2) are satisfied.
0.02 ≦ X ₁ ≦ 0.08 (1)
0.10 ≦ X ₀ / X ₁ ≦ 0.90 (2)
Incidentally, the average crosslink density of X ₀ in relation with the polyester resin (A) and the polyester resin (B), X ₁ represents an average crosslink density of the resin composition (C).
The relational expression (1) and the relational expression (2) will be described in detail later.

The resin composition (C) contained in the toner binder of the present invention can be obtained by mixing and reacting a melt mixture of two or more kinds of amorphous polyester resins having different glass transition temperatures with an extender (D).

The amorphous polyester resin (A) and the amorphous polyester resin (B) used in the toner of the present invention are not particularly limited as long as they are amorphous polyesters.
Here, the term “amorphous” means that the ratio of softening temperature (° C.) to the maximum peak temperature of heat of fusion (° C.) (softening temperature / maximum peak temperature of heat of fusion) is greater than 1.55, It indicates that it exhibits a softening property.

The glass transition temperature Tg _A of the amorphous polyester resin (A) must be −35 ° C. or higher and lower than 45 ° C. When Tg _A is 45 ° C. or higher, the low-temperature fixability deteriorates, and when it is lower than −35 ° C., the heat resistant storage stability deteriorates.
The glass transition temperature Tg _B of the amorphous polyester resin (B) must be 45 ° C. or higher and 80 ° C. or lower. When Tg _B exceeds 80 ° C., the low-temperature fixability deteriorates, and when it is lower than 45 ° C., the heat resistant storage stability deteriorates.
In addition, glass transition temperature (Tg) can be measured by the method (DSC method) prescribed | regulated to ASTM D3418-82, for example using Seiko Instruments Co., Ltd. DSC20 and SSC / 580.

The amorphous polyester resin (A) and the amorphous polyester resin (B) are obtained by polycondensing one or more polyol components (x) as raw material components and one or more polycarboxylic acid components (y).
Examples of the polyol component (x) include diols and 3 to 8 or more valent polyols, and examples of the polycarboxylic acid component (y) include dicarboxylic acids and 3 to 6 or more valent polycarboxylic acids. .

Examples of the polyol component (x) of the amorphous polyester resin (A) and the amorphous polyester resin (B) used in the present invention include diols and 3 to 8 or more polyols.
Examples of the diol include alkylene glycols having 2 to 36 carbon atoms (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1, 9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 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-cyclohexane) Dimethanol and hydrogenated bisphenol A, etc.);
(Poly) oxyalkylene of the above alicyclic diol (the same applies to polyoxyalkylene groups having 2 to 4 carbon atoms (oxyethylene, oxypropylene, etc.) of the alkylene group) ether [oxyalkylene unit (hereinafter abbreviated as AO unit)] Formula 1-30];
Divalent phenols [monocyclic divalent phenols (for example, hydroquinone), polyoxyalkylene ethers of bisphenols (number of AO units 2 to 30)], and the like.
Polyoxyalkylene ethers of bisphenols are usually obtained by adding alkylene oxide (hereinafter sometimes abbreviated as AO) to bisphenols. Examples of bisphenols include those represented by the following general formula (1).

OH-Ar-X-Ar-OH (1)
[Wherein X represents an alkylene group having 1 to 3 carbon atoms, —SO ₂ —, —O—, —S—, or a direct bond; Ar represents a halogen atom or an alkyl group having 1 to 30 carbon atoms; Represents an optionally substituted phenylene group. ]

  Specifically, for example, bisphenol A, bisphenol F, bisphenol B, bisphenol AD, bisphenol S, trichlorobisphenol A, tetrachlorobisphenol A, dibromobisphenol F, 2-methylbisphenol A, 2,6-dimethylbisphenol A and 2 , 2′-diethylbisphenol F, and two or more of these may be used in combination.

As AO added to these bisphenols, those having 2 to 4 carbon atoms are preferable. Specifically, ethylene oxide (hereinafter sometimes abbreviated as EO), propylene oxide (hereinafter abbreviated as PO). ), 1,2-, 2,3-, 1,3- or iso-butylene oxide, tetrahydrofuran, and a combination of two or more thereof.
Of these, EO and / or PO are preferred. The added mole number of AO is preferably 2 to 30 moles, more preferably 2 to 10 moles.
Of the polyoxyalkylene ethers of bisphenols, EO and / or PO adducts of bisphenol A (average added mole number of 2 to 4, particularly 2 to 3) are preferable from the viewpoint of toner fixing properties.

As the polyol component (x), the polyol having a valence of 3 to 8 or higher is an aliphatic polyhydric alcohol having 3 to 8 or more carbon atoms (alkane polyol and its intramolecular or intermolecular). Dehydrates such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, polyglycerin and dipentaerythritol);
Sugars and derivatives thereof such as sucrose and methyl glucoside);
(Poly) oxyalkylene ethers of the above aliphatic polyhydric alcohols (number of AO units 1 to 30);
Polyoxyalkylene ethers of trisphenols (such as trisphenol PA) (number of AO units 2 to 30);
Examples thereof include polyoxyalkylene ethers (number of AO units: 2 to 30) of novolak resins (phenol novolac, cresol novolac, etc., average degree of polymerization of 3 to 60).

  Among these polyol components (x), those preferable from the viewpoint of achieving both low-temperature fixability and hot offset resistance are alkylene glycols having 2 to 12 carbon atoms, polyoxyalkylene ethers of bisphenols (number 2 to 2 of AO units). 30), an aliphatic polyhydric alcohol having 3 to 8 valences or more, and a polyoxyalkylene ether of a novolac resin (number of AO units: 2 to 30). More preferable from the viewpoint of storage stability are alkylene glycols having 2 to 10 carbon atoms, polyoxyalkylene ethers of bisphenols (2 to 5 of AO units), polyoxyalkylene ethers of novolac resins (2 of AO units). ~ 30). Particularly preferred are alkylene glycols having 2 to 6 carbon atoms and polyoxyalkylene ethers of bisphenol A (number of AO units 2 to 5), and most preferred are polyoxyalkylene ethers of ethylene glycol, propylene glycol and bisphenol A ( The number of AO units is 2-3).

Examples of the polycarboxylic acid component (y) of the amorphous polyester resin (A) and the amorphous polyester resin (B) used in the present invention include dicarboxylic acids and tri- or hexavalent or higher polycarboxylic acids.
Examples of the dicarboxylic acid 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 alkene dicarboxylic acids having 4 to 50 carbon atoms (alkenyl such as dodecenyl succinic acid). Succinic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, and glutaconic acid), aromatic dicarboxylic acids having 8 to 36 carbon atoms (phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.), Saturated carboxylic 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, etc.) and the like. .

Examples of polycarboxylic acids having 3 to 6 or more valences include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid), and aliphatic tricarboxylic acids having 6 to 36 carbon atoms ( Hexanetricarboxylic acid, etc.), vinyl polymer of unsaturated carboxylic acid [Mn: 450-10,000] (styrene / maleic acid copolymer, styrene / acrylic acid copolymer, styrene / fumaric acid copolymer, etc.) Etc.
As the polycarboxylic acid component (y), anhydrides and lower alkyl (carbon number 1 to 4) esters (methyl esters, ethyl esters, isopropyl esters, etc.) of these polycarboxylic acids may be used. You may use together with carboxylic acid.

  Among these polycarboxylic acid components (y), those preferable from the viewpoint of achieving both low temperature fixability and hot offset resistance are alkanedicarboxylic acids having 2 to 50 carbon atoms, alkenedicarboxylic acids having 4 to 50 carbon atoms, carbon An aromatic dicarboxylic acid having 8 to 20 carbon atoms and an aromatic polycarboxylic acid having 9 to 20 carbon atoms. More preferable from the viewpoint of storage stability are 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 adipic acid, terephthalic acid, trimellitic acid, and combinations thereof. Likewise preferred are anhydrides and lower alkyl esters of these acids.

In the present invention, each of the amorphous polyester resin (A) and the amorphous polyester resin (B) 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 more, particularly preferably 2 to 40 hours, from the viewpoint of reliably performing the polycondensation 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, titanium terephthalate alkoxide, Japanese Patent Application Laid-Open No. 2006-243715. Patent Documents [Titanium dihydroxybis (triethanolamate), titanium monohydroxytris (triethanolamate), titanylbis (triethanolaminate) and their intramolecular polycondensates, etc.], and JP2007- No. 11307 catalyst (titanium tributoxyterephthalate, titanium triisopropoxyterephthalate, titanium diisopropoxyditerephthalate, etc.)], zirconium-containing catalyst (for example, zirconyl acetate), and acetic acid Lead and the like. Among these, a titanium-containing catalyst is preferable. 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 1.4 / 1 to 1 / 1.2.

The amorphous polyester resin (A) having a glass transition temperature of −35 ° C. or higher and lower than 45 ° C. preferably has active hydrogen at the end of the main chain from the viewpoint of hot offset properties.
Examples of the terminal functional group having active hydrogen include an amino group, a hydroxyl group, and a carboxyl group, and a hydroxyl group and a carboxyl group are preferred.

  The acid value of the amorphous polyester resin (A) is preferably 0 to 15 mgKOH / g, more preferably 0 to 10 mgKOH / g, and particularly preferably 0 to 5 mgKOH / g from the viewpoint of chargeability stability.

  The acid value of the amorphous polyester resin (A) represents the amount of all acid groups present in (A). In addition to the proton acid that (A) originally has, the acid value of the acid anhydride group present in (A) is determined by hydrolyzing the acid anhydride group into two protonic acids. It is a numerical value expressed in mg of the weight of potassium hydroxide necessary to neutralize all the protonic acids it has.

The acid value of the amorphous polyester resin (A) can be measured by the following method.
1) About 0.5 g of the pulverized product of (A) is precisely weighed, and its weight is defined as S (g).
2) Put the pulverized product (A) in a 200 ml Erlenmeyer flask, add 25 ml of pyridine, and dissolve at 100 ° C. for 1.5 hours.
3) Add 3 ml of ion exchange water and heat for 10 minutes, then cool to room temperature.
4) Add 50 ml of THF, add several drops of phenolphthalein indicator, and titrate with 0.1 N KOH / THF solution. The amount of the KOH solution at this time is A (ml). At the same time, a blank test is performed, and the amount of KOH solution at this time is defined as B (ml).
5) The acid value of (A) is measured by the following formula.
Acid value of (A) = (A−B) × f × 5.61 ÷ S (f: titer of KOH solution)

The hydroxyl value of the amorphous polyester resin (A) is preferably 10 to 80 mgKOH / g, more preferably 20 to 60 mgKOH / g, and particularly preferably 30 to 40 mgKOH / g. When the hydroxyl value is 80 mgKOH / g or less, the low-temperature fixability and glossiness when used as a toner are improved.
The hydroxyl value of (A) can be measured by a method specified in JIS K0070 (1992 edition).

The acid value of the amorphous polyester resin (B) having a glass transition temperature of 45 ° C. or higher and 80 ° C. or lower is preferably 5 to 30 mgKOH / g, more preferably 10 to 20 mgKOH / g, and particularly preferably 13 to 17 mgKOH / g. . When the acid value is 30 mgKOH / g or less, the charging characteristics when used as a toner are good.

The hydroxyl value of (B) is preferably 0 to 5 mgKOH / g, more preferably 0.001 to 3 mgKOH / g, and particularly preferably 0.01 to 1 mgKOH / g. When the hydroxyl value is 5 mgKOH / g or less, the low-temperature fixability and glossiness when used as a toner are improved.

The acid value and hydroxyl value of (B) can also be measured by the method prescribed in JIS K0070 (1992 version).

In the measurement of acid value and hydroxyl value of amorphous polyester resin (A) and amorphous polyester resin (B), if the sample has a solvent-insoluble component accompanying crosslinking, the sample after melt-kneading by the following method Used as
Kneading device: Labo plast mill MODEL4M150 manufactured by Toyo Seiki Co., Ltd.
Kneading conditions: 130 ° C., 70 rpm, 30 minutes

  The peak top molecular weight of the amorphous polyester resin (A) soluble in tetrahydrofuran (THF) (hereinafter sometimes abbreviated as Mp) is 4,000 from the viewpoint of compatibility between toner durability and low-temperature fixability. -50,000 is preferable, More preferably, it is 8,700-25,000.

  The Mp of the THF-soluble component of the amorphous polyester resin (B) is preferably 2,000 to 15,000, more preferably 3,500 to 10, from the viewpoint of achieving both heat-resistant storage stability and low-temperature fixability of the toner. 000, particularly preferably 5,000 to 6,500.

In the present invention, the molecular weight [Mp, Mn, weight average molecular weight (hereinafter referred to as Mw)] of a resin such as a polyester resin can be measured using GPC under the following conditions.
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 device: Refractive index detector Reference material: Tosoh Co., Ltd. standard polystyrene (TSK standard POLYSTYRENE) 12 points (molecular weight 500 1,050 2,800 5,970 9,100 18,100 37,900 96,400 190,000 355,000 1,090,000 2,890,000)
The molecular weight is measured by dissolving a polyester resin or the like in THF and filtering out the insoluble matter with a glass filter.

  From the viewpoint of hot offset resistance, the THF-insoluble content of the amorphous polyester resin (A) is preferably 0 to 50% by weight, more preferably 1 to 35% by weight, based on the weight of (A).

  From the viewpoint of low-temperature fixability, the THF-insoluble content of the amorphous polyester resin (B) is preferably 0 to 50% by weight, more preferably 0 to 20% by weight based on the weight of (B).

The THF-insoluble content of the amorphous polyester resin (A) and the amorphous polyester resin (B) 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.

The resin composition (C) of the present invention can be obtained by mixing and reacting an elongation agent (D) with a molten mixture of an amorphous polyester resin (A) and an amorphous polyester resin (B). (D) will not be limited if there exists a functional group which reacts with an amorphous polyester resin (A) at least.
As the functional group, an isocyanate group, a vinyl group, an epoxy group, a carboxyl group, a silanol group, or the like is preferably used.

Especially, it is preferable that an extending | stretching agent (D) is a compound (D1) which has an isocyanate group. Further, an extender having three or more functional groups is preferred from the viewpoints of low-temperature fixability, offset resistance, and heat-resistant storage stability.

Examples of the compound (D1) having an isocyanate group that is preferable as the extender (D) include a divalent diisocyanate compound (D12) and a 3-8 valent polyisocyanate compound (D11).

Examples of the divalent diisocyanate compound (D12) include aliphatic diisocyanate compounds, alicyclic diisocyanates, and aromatic diisocyanate compounds.

Examples of the aliphatic diisocyanate compound include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethyl. And hexamethylene diisocyanate.

Examples of the alicyclic diisocyanate compound include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated triisocyanate. Examples include range isocyanate and hydrogenated tetramethylxylylene diisocyanate.

As the aromatic diisocyanate compound, for example, phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2 ′ monodiphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4 ′ -Toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate and the like.

Among the divalent diisocyanate compounds (D12), preferred are aromatic diisocyanates having 6 to 15 carbon atoms, aliphatic diisocyanates having 4 to 12 carbon atoms, and alicyclic diisocyanates having 4 to 15 carbon atoms. TDI, MDI, HDI, hydrogenated MDI, and IPDI.

Although it will not specifically limit as a 3-8 valent polyisocyanate compound (D11) if it is a compound which has 3-8 isocyanate groups, The compound etc. which contain the chemical structure of triisocyanate, tetraisocyanate, isocyanurate, biuret, etc. are mentioned. It is done.

Examples of the triisocyanate compound include a compound represented by the following chemical formula (1).

[Wherein, R ₁ represents an alkyl group, and R ₂ represents an alkylene group. ]

Examples of the tetraisocyanate compound include a compound represented by the following chemical formula (2).

[Wherein R ₂ represents an alkylene group. ]

Examples of the compound having an isocyanurate structure include an isocyanurate trimer and an isocyanurate pentamer, and also an isocyanurate heptamer and a multimer more than a 9-mer.
The isocyanurate trimer is a polyisocyanate composed of three diisocyanate monomers and having an isocyanurate group, and examples thereof include compounds represented by the following chemical formula (3).

  [Wherein R represents a diisocyanate monomer residue. ]

The isocyanurate pentamer is a polyisocyanate having an isocyanurate structure composed of 6 molecules of a diisocyanate monomer, and examples thereof include compounds represented by the following chemical formula (4).

  [Wherein R represents a diisocyanate monomer residue. ]

The compound having a biuret structure is formed from urea and an isocyanate group, and examples thereof include a compound represented by the following chemical formula (5).

[Wherein R represents a diisocyanate monomer residue. ]

Of the above-mentioned compound (D1) having an isocyanate group as the extender (D), a 3- to 8-valent polyisocyanate compound (D11) is preferable from the viewpoints of low-temperature fixability, offset resistance, and heat-resistant storage stability.
Furthermore, 1 or more types of polyisocyanate compounds (D111) chosen from the group which consists of isocyanurate and biuret among 3-8 valent polyisocyanate compounds (D11) are preferable.

The amount of the extender (D) used is preferably 0.2 to 2.0 equivalents as an isocyanate group per equivalent of the amorphous polyester resin (A) and the amorphous polyester resin (B).

The average crosslinking density (X ₀ ) in the relational expression (2) is the crosslinking density of the mixture of the polyester resin (A) and the polyester resin (B), and is a mixture of the polyester resin (A) and the polyester resin (B). Is a value representing the degree of branching, and is defined as follows.
When n types of trivalent or higher raw material components (trivalent or higher polyol component and polycarboxylic acid component) are used among the raw materials of the polyester resin (A), the trivalent or higher raw material components of the polyester resin (A) The k-th mole number is ak, and the k-th valence of the raw material component is αk.
In addition, when a total of m kinds of divalent raw material components (diol component and dicarboxylic acid component) and monofunctional raw material components (monoalcohol component and monocarboxylic acid component) among the raw materials of the polyester resin (A) are used, The j-th mole number of the divalent raw material component and the monofunctional raw material component of the polyester resin (A) is defined as bj.

Here, the amount of the polyester resin (A) (weight) and T _A, the weight ratio of the k-th structural units to the total constituent units of the polyester resin (A) and gk, the formula weight of the k-th structural unit When Mk is set, ak, which is the k-th mole number of the trivalent or higher structural unit among the structural units of the polyester resin (A), is calculated by the following calculation formula.
ak in the case where the k-th structural unit is derived from a polycarboxylic acid or a polyol,

Similarly, when n types of trivalent or higher raw material components (trivalent or higher polyol component and polycarboxylic acid component) are used among the raw materials of the polyester resin (B), the trivalent or higher valence of the polyester resin (A) is used. The k-th mole number of the raw material component is ck, and the k-th valence of the raw material component is βk.
In addition, when a total of m kinds of divalent raw material components (diol component and dicarboxylic acid component) and monofunctional raw material components (monoalcohol component and monocarboxylic acid component) among the raw materials of the polyester resin (B) are used, The j-th mole number of the divalent raw material component and the monofunctional raw material component of the polyester resin (B) is defined as dj.

In the case of the polyester resin (B), similarly, the amount of the polyester resin (B) (weight) and T _B, the weight ratio of the k-th raw component to all the constituent units of the polyester resin (B) and hk, When the formula amount of the k-th structural unit is Mk, ck, which is the k-th mole number of the tri- or higher valent structural unit among the structural units of the polyester resin (B), is calculated by the following formula. The
When the kth structural unit is derived from polycarboxylic acid or polyol, ck is

Based on the above assumption, the crosslinking density (X ₀ ) of the mixture of the polyester resin (A) and the polyester resin (B) is calculated by the following calculation formula.

For example, 10 mol of trivalent trimethylolpropane is used as the raw material component of the polyester resin (A), and 15 mol of divalent adipic acid is used as the raw material component of the polyester resin (B), and 10 mol of trivalent trimethylolpropane is used as the raw material component of the polyester resin (B). When 5 moles of trivalent trimellitic acid, 20 moles of divalent propylene glycol and 15 moles of divalent adipic acid are used,
_{X 0 = {10 × (3-2} ) + 10 × (3-2) + 5 × (3-2)} / {10 + 15 + 10 + 5 + 20 + 15}
= 0.33.

The average crosslinking density (X ₁ ) of the resin composition (C) of the present invention satisfies the following relational expression (1).
0.02 ≦ X ₁ ≦ 0.08 (1)
When the average crosslink density (X ₁ ) is less than 0.02, the offset resistance is deteriorated, and when it is more than 0.08, the low-temperature fixability and the glossiness are deteriorated.

Here, the average crosslink density (X ₁ ) is the average crosslink density of the resin composition (C), which is a value representing the degree of branching of the resin composition (C), and is defined as follows: Can be calculated.
A resin composition (C) is manufactured using a polyester resin (A), a polyester resin (B), and an extender (D).
In calculating the average crosslinking density (X ₁ ) in the relational expression (1) and in the relational expression (2), as described below, each of the polyester resin (A) and the polyester resin (B). The structural unit is decomposed and calculated according to the valence, and the extender is also calculated according to the valence.

When n types of tri- or higher valent extender components are used as the extender (D), the k-th mole number of the tri- or higher valent extender component is ek and the valence is γk.
When a total of m types of divalent extender components and monofunctional extender components in the extender (D) are used, the divalent extender component and monofunctional extension in the extender (D) are used. The j-th mole number of the agent component is defined as fj.

When using one or more as extenders (D), ek is the number of moles of the k-th extenders, k-th amount of extender (D) (weight) and T _Dk, raw When the molecular weight of M is Mk, it is calculated by the following formula.

In addition, ak is the same as the k-th mole number of the trivalent or higher raw material component of the used polyester resin (A) as described in the cross-linking density (X ₀ ).
The k-th mole number ck of the trivalent or higher raw material component of the used polyester resin (B) is the same as that described in the cross-linking density (X ₀ ).

Based on the above assumption, the average crosslink density (X ₁ ) of the resin composition (C) is calculated by the following calculation formula.

Furthermore, the present invention mean the crosslink density (X ₁₎ and the resin (C), the following relation formula showing the relationship between the average crosslink density of the polyester resin (A) and the polyester resin (B) (X ₀₎ to (2) It is essential that the toner binder is satisfied.
0.10 ≦ X ₀ / X ₁ ≦ 0.90 (2)

The value of X ₀ / X ₁ is usually 0.10 to 0.90, preferably 0.15 to 0.85, and more preferably 0.20 to 0.80. When the value of X ₀ / X ₁ is low, the hot offset resistance deteriorates, and when it is high, the low-temperature fixability deteriorates.

The resin composition (C) of the present invention is not particularly limited as long as the resin composition (C) is obtained by mixing and reacting the melted mixture of the amorphous polyester resin (A) and the amorphous polyester resin (B) with the extender (D).
From the viewpoint of low-temperature fixability and offset property, the resin composition (C) has one or more functional groups selected from the group consisting of ester groups, urethane groups, urea groups, biuret groups, and allophanate groups. Further preferred.

The resin composition (C) of the present invention is obtained by mixing and reacting an extender (D) with a molten mixture of an amorphous polyester resin (A) and an amorphous polyester resin (B). The weight ratio (A) / (B) of (A) to the polyester resin (B) is preferably 5/95 to 15/85 from the viewpoint of low-temperature fixability, glossiness, and offset resistance.

The melted mixture of the amorphous polyester resin (A) and the amorphous polyester resin (B) is reacted by mixing the extender (D). It is preferable from the viewpoint of productivity.
Examples thereof include a method of kneading a melt of the amorphous polyester resin (A) and a melt of the amorphous polyester resin (B), adding an extender (D) to the kneaded material, and melt-kneading.
As a specific method for carrying out this melt mixing, a mixture of an amorphous polyester resin (A) and an amorphous polyester resin (B) is injected into a twin-screw extruder at a constant speed, and at the same time, the elongation agent (D) is also constant. There are also methods such as injecting at a constant speed and carrying out the reaction while kneading and conveying at a temperature of 100 to 200 ° C.
At this time, the amorphous polyester resin (A) and the amorphous polyester resin (B), which are reaction raw materials charged or injected into the twin-screw extruder, are directly injected into the extruder as they are without cooling from the resin reaction solution. Alternatively, the resin once produced may be cooled and pulverized and supplied to a twin screw extruder.
However, in the present invention, the method for producing the resin composition (C) is not limited to these specifically exemplified methods, and a temperature at which a raw material is charged in a conventionally known method, for example, a reaction vessel, and becomes a solution state. Of course, it can be performed by an appropriate method such as heating and mixing.

The volatile content of the resin composition (C) obtained by mixing and reacting the extender (D) with the molten mixture of the polyester resin (A) and the polyester resin (B) is 100 ppm or less from the viewpoint of heat resistant storage stability. Preferably there is.

Here, the volatile content of the resin composition (C) is the residual content of the organic solvent used to obtain the polyester resin (A), the raw material component of the polyester resin (B), the extender (D) and / or (C). It means the total amount of volatile components derived from raw materials and organic solvents.

  The volatile components derived from the raw materials include the acid component, alcohol component, and extender (D) described above. The organic solvent is defined by the Industrial Safety and Health Law Enforcement Ordinance (Organic solvent poisoning prevention regulations, Chapter 1, Article 1). And the like (first type organic solvent, second type organic solvent, third type organic solvent).

As a method for reducing the volatile content of the resin composition (C), for example, a method using a process that does not use an organic solvent, a predetermined raw material component amount or a solvent amount at a temperature of 150 to 200 ° C. and a low pressure (for example, 1 kPa or less). The method of continuing devolatilization until the temperature reaches 150 ° C. or 200 ° C. After water or steam is injected so that the pressure becomes 0.1 to 0.5 MPa, the raw material components and the solvent are azeotroped as reduced pressure (for example, 1 kPa or less). And a method of removing the resin in a thin film state at a temperature of 150 to 200 ° C. under a low pressure (for example, 1 kPa or less).

The toner binder of the present invention preferably contains a crystalline resin (E) in addition to the resin composition (C) from the viewpoint of low-temperature fixability.

“Crystallinity” of the crystalline resin in the present invention is the ratio between the softening temperature measured by the Koka flow tester and the maximum peak temperature (melting point) of the heat of fusion measured by a differential scanning calorimeter (DSC). (Softening temperature / Maximum peak temperature of melting heat (melting point)) is preferably 0.80 to 1.55, and is a property of being softened sharply by heat. A resin having this property is referred to as “crystalline resin”. To do.

The weight ratio of the resin composition (C) to the crystalline resin (E) is usually from 95/5 to 50 in terms of toner fluidity, heat-resistant storage stability, grindability, image strength after fixing, low-temperature fixability, and glossiness. / 50, preferably 92/8 to 70/30, more preferably 90/10 to 80/20.
The crystalline resin (E) is not particularly limited in its chemical structure as long as it is compatible with the resin composition (C). Examples thereof include compounds such as crystalline polyester, crystalline polyurethane, crystalline polyurea, crystalline polyamide, and crystalline polyvinyl. Among these, crystalline polyester is preferable from the viewpoint of compatibility. From the viewpoint of crystallinity, a crystalline polyester resin in which the linear aliphatic diol content of the diol component is 80 mol% or more is preferable.

The toner composition of the present invention contains the toner binder of the present invention and a colorant.
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, Orazole Brown B, 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, or nickel or a compound such as magnetite, hematite, or ferrite) can also be included as a colorant.
The content of the colorant is preferably 1 to 40 parts by weight, more preferably 3 to 10 parts by weight with respect to 100 parts by weight of the toner binder of the present invention. In addition, when using magnetic powder, Preferably it is 20-150 weight part, More preferably, it is 40-120 weight part.

In addition to the toner binder and the colorant, the toner of the present invention contains one or more additives selected from a mold release agent, a charge control agent, a fluidizing agent, and the like as necessary.
As the mold release agent, those having a softening point [Tm] of 50 to 170 ° C. by a flow tester are preferable, polyolefin wax, natural wax, aliphatic alcohol having 30 to 50 carbon atoms, fatty acid having 30 to 50 carbon atoms, and these A mixture etc. are mentioned.

  Polyolefin waxes include (co) polymers [obtained by (co) polymerization] of olefins (for example, ethylene, propylene, 1-butene, isobutylene, 1-hexene, 1-dodecene, 1-octadecene, and mixtures thereof). And olefin (co) polymer oxides with oxygen and / or ozone, maleic acid modifications of olefin (co) polymers [eg maleic acid and its derivatives (maleic anhydride, Modified products such as monomethyl maleate, monobutyl maleate and dimethyl maleate), olefins and unsaturated carboxylic acids [such as (meth) acrylic acid, itaconic acid and maleic anhydride] and / or unsaturated carboxylic acid alkyl esters [(meta ) Alkyl acrylate (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 release agent is 0 to 30% by weight, preferably 0.5 to 20% by weight, particularly preferably 1 to 10% by weight, based on the toner weight.
The charge control agent is 0 to 20% by weight, preferably 0.1 to 10% by weight, particularly preferably 0.5 to 7.5% by weight, based on the toner weight.
The fluidizing agent is 0 to 10% by weight, preferably 0 to 5% by weight, particularly preferably 0.1 to 4% by weight, based on the toner weight.
The total amount of additives is 3 to 70% by weight, preferably 4 to 58% by weight, particularly preferably 5 to 50% by weight, based on the toner weight. When the composition ratio of the toner is in the above range, a toner having good chargeability can be easily obtained.

The toner of the present invention may be obtained by any known method such as kneading and pulverization, emulsion phase inversion, and polymerization.
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.

<Production Example 1><Synthesis of Polyester Resin (A-1)>
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 2,854 parts (8.2 moles) of bisphenol A · PO2 mole adduct, 4,838 parts of 3-methyl-1,5-pentanediol (41 parts) (41 0.0 mol), 187.6 parts (1.4 mol) of trimethylolpropane, 8,184 parts (49.3 mol) of terephthalic acid and 20.0 parts of tetrabutoxy titanate as a condensation catalyst, and a nitrogen stream at 220 ° C. Below, it was made to react for 4 hours, distilling off the water to produce | generate. Furthermore, it was made to react under the reduced pressure of 0.5-2.5 kPa for 10 hours. The polyester resin (A-1) was obtained by taking out when the acid value became less than 1. Polyester resin (A-1) had a Tg of 16 ° C., a hydroxyl value of 35, a number average molecular weight of 3,200, and a weight average molecular weight of 9,400.

<Production Examples 2 to 4><Synthesis of polyester resins (A-2) to (A-4)>
A polybasic acid and a polyhydric alcohol described in Table 1 were charged into a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and the reaction was conducted in the same manner as in Production Example 1 except that the polyester resin (A- 2) to (A-4) were obtained.

<Comparative Production Example 1><Synthesis of Polyester Resin (A′-1)>
A polybasic acid and a polyhydric alcohol listed in Table 1 were charged into a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and the reaction was conducted in the same manner as in Production Example 1 except that the polyester resin (A ′ -1) was obtained. The polyester resin (A′-1) has a glass transition temperature of −38 ° C. and does not correspond to the polyester resin (A).

<Production Example 5><Synthesis of polyester resin (B-1)>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 16,079 parts (46.2 moles) of bisphenol A · PO2 mole adduct, 1,659 parts (13.6 moles) of benzoic acid, condensation catalyst Then, 20.0 parts of dibutyltin oxide was added and reacted at 200 ° C. under a nitrogen stream for 4 hours while distilling off generated water. Next, 6,009 parts (36.2 mol) of terephthalic acid and 10.0 parts of dibutyltin oxide as a condensation catalyst were added, and then the temperature was gradually raised to 230 ° C., and the pressure was reduced to 0.5 to 2.5 kPa. The reaction was performed for 4 hours. Next, the mixture was cooled to 180 ° C., 787 parts (4.1 mol) of trimellitic anhydride was added, and after reaction for 2 hours under normal pressure sealing, the reaction was performed at 220 ° C. under normal pressure, and when the hydroxyl value was less than 1. The polyester resin (B-1) was obtained by taking out.
Polyester resin (B-1) had a Tg of 56 ° C., a hydroxyl value of 0, a number average molecular weight of 2,300, and a weight average molecular weight of 7,000.

<Production Examples 6 to 9><Synthesis of polyester resins (B-2) to (B-5)>
A polybasic acid and a polyhydric alcohol shown in Table 2 were charged into a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and the reaction was conducted in the same manner as in Production Example 5 except that the polyester resin ( B-2) to (B-5) were obtained.

<Comparative Production Example 2><Synthesis of Polyester Resin (B′-1)>
A polybasic acid and a polyhydric alcohol shown in Table 2 were charged into a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and the reaction was conducted in the same manner as in Production Example 5 except that the polyester resin (B ′ -1) was obtained. Polyester resin (B′-1) has a glass transition temperature of 81 ° C. and does not correspond to polyester resin (B).

<Example 1><Synthesis of Resin Composition (C-1)>
Supply 90.3 parts of polyester resin (A-1) with a water content of 2,000 ppm and 9.7 parts of polyester resin (B-1) to a twin-screw kneader (Kurimoto Iron Works, S5KRC kneader) at 10 kg / hr. Simultaneously, Duranate TPA-100 (manufactured by Asahi Kasei Chemicals Co., Ltd.) was supplied at 0.34 kg / hr as an extender (D), and a kneading extrusion reaction was carried out at 150 ° C. What was obtained was cooled and the resin composition (C-1) was obtained.

<Examples 2 to 4><Synthesis of Resin Compositions (C-2) to (C-4)>
The polyester resins (A-1) and (A-2) shown in Table 3, polyester resins (B-1) to (B-3), and an extender (D) were charged and reacted according to Example 1. Resin compositions (C-2) to (C-5) were obtained.

<Comparative Examples 1-5><Synthesis of Resin Compositions (C′-1) to (C′-5)>
Polyester resins (A-1), (A-3), (A-4), (A′-1) and polyester resins (B-1), (B-4), (B-5) shown in Table 3 ), (B′-1) and the extender (D) were charged and reacted according to Example 1 to obtain resin compositions (C′-1) to (C′-5).

<Example 5><Creation of toner (T-1)>
6 parts of carbon black MA-100 [manufactured by Mitsubishi Chemical Corporation], 4 parts of carnauba wax, charge control agent T-77 [manufactured by Hodogaya Chemical Co., Ltd.] 4 with respect to 85 parts of the resin composition (C-1) Toner was added 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.]. Next, the mixture was finely pulverized using a supersonic jet crusher lab jet [manufactured by Nippon Pneumatic Industry Co., Ltd.] and then classified by an airflow classifier [MDS-I made by Nippon Pneumatic Industry Co., Ltd.] Toner particles having a D50 of 8 μm were obtained.
Next, 100 parts of toner particles and 1 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil) were mixed in a sample mill to obtain the toner (T1) of the present invention.

<Production Examples 6 to 9><Preparation of Toners (T-2) to (T-5)>
Toners were prepared in the same manner as in Example 5 with reference to Table 4, with reference to Table 4. Toners (T-2) to (T-5) were obtained. Next, evaluation was made in the same manner as in Example 5, and the results are shown in Table 4.
The crystalline resin (E-1) used in Example 9 was Polyester SP170 manufactured by Nippon Synthetic Chemical Co., Ltd., which is a crystalline polyester resin.

<Comparative Examples 6 to 10><Preparation of Toners (T′-1) to (T′-5)>
Toners were produced in the same manner as in Example 5 with reference to Table 4, with reference to Table 4. Toners (T′-1) to (T′-5) were obtained. Next, evaluation was made in the same manner as in Example 5, and the results are shown in Table 4.

[Evaluation method]
Low-temperature fixability, glossiness, hot offset resistance, fluidity, heat-resistant storage stability, charge stability, grindability, image strength, folding resistance, document offset test measurement method, evaluation method, and toner obtained below The criteria will be described.

<Low temperature fixability>
The toner is uniformly placed on the paper so as to be 0.8 mg / cm ² . At this time, as a method of placing the powder on the paper surface, a printer from which the heat fixing machine is removed is used. Other methods may be used as long as the powder can be uniformly loaded with the above-described weight density.
The cold offset generation temperature (MFT) was measured when this paper was passed through a pressure roller under conditions of a fixing speed (heating roller peripheral speed) of 213 mm / sec and a fixing pressure (pressure roller pressure) of 10 kg / cm ² .
The lower the temperature at which cold offset occurs, the better the low-temperature fixability.

<Glossiness>
Fixation evaluation is performed in the same manner as low-temperature fixability. White cardboard was laid under the image, and the glossiness (%) of the printed image was measured at an incident angle of 60 degrees using a gloss meter (“IG-330” manufactured by Horiba, Ltd.). Higher gloss means better gloss.

<Hot offset resistance (hot offset temperature)>
Fixation was evaluated in the same manner as the low-temperature fixability, and the presence or absence of hot offset on the fixed image was visually evaluated.
The temperature at which hot offset occurred after passing through the pressure roller was defined as hot offset resistance (° C.).

<Fluidity>
The toner bulk density (g / 100 ml) was measured with a powder tester manufactured by Hosokawa Micron, and the fluidity was determined according to the following criteria.

[Criteria]
○: 30 or more ×: less than 30

<Heat resistant storage stability>
The toner was allowed to stand in an atmosphere of 50 ° C. for 24 hours, the degree of blocking was judged visually, and the heat resistant storage stability was evaluated according to the following criteria.
[Criteria]
○: Blocking has not occurred.
Δ: Blocking occurs in part.
X: Blocking has occurred throughout.

<Charging stability>
(1) 0.5 g of toner and 20 g of a ferrite carrier (F-150, manufactured by Powdertech) are placed in a 50 ml glass bottle, and the humidity is adjusted at 23 ° C. and a relative humidity of 50% for 8 hours or more.
(2) Friction stirring was performed at 50 rpm × 20 minutes and 60 minutes with a tumbler shaker mixer, and the charge amount at each time was measured.
For the measurement, a blow-off charge measuring device [manufactured by Toshiba Chemical Co., Ltd.] was used.
“Charging amount of 60 minutes of friction time / charging amount of 20 minutes of friction time” was calculated and used as an index of charging stability.

[Criteria]
○: 0.7 or more Δ: 0.6 or more and less than 0.7 ×: less than 0.6

<Crushability>
The coarsely pulverized product kneaded and cooled by a biaxial kneader (8.6 mesh pass to 30 mesh on) was finely pulverized under the following conditions by a supersonic jet pulverizer, Labo Jet [manufactured by Nippon Pneumatic Industry Co., Ltd.]. Crushed.
Crushing pressure: 0.5 MPa
Grinding time: 10 minutes Adjuster ring: 15 mm
Size of louver: The volume average particle size (μm) was measured with Coulter Counter-TAII (manufactured by Coulter Electronics, USA) without classifying the louver, and the grindability was evaluated according to the following criteria.

[Criteria]
◎: Less than 10 ○: 10 or more and less than 11 Δ: 11 or more and less than 12 ×: 12 or more

<Image intensity>
The image fixed in the evaluation of the low temperature fixability was subjected to a scratch test by applying a load of 10 g from right above the pencil fixed at an angle of 45 degrees according to JIS K5600, and the image strength was evaluated from the pencil hardness without scratches. .
Higher pencil hardness means better image strength.

<Bending resistance>
The image fixed in the evaluation of the low-temperature fixability is folded so that the image surface is on the inside, and rubbed three times with a load of 30 g.
The presence or absence of white streaks after the paper was spread and folded on the image was visually judged.
[Criteria]
○: No white streak
Δ: Slight white streak ×: White streak

<Document offset property>
Two sheets of A4 paper on which an image obtained by evaluation of low-temperature fixability is fixed are overlapped with each other on a fixing surface, applied with a weight of 420 g (0.68 g / cm ² ), and left at 60 ° C. for 30 minutes. .
The document offset property was evaluated according to the following criteria for the state when the stacked papers were pulled apart.

[Criteria]
○: No resistance △: Crisp sound but image does not peel off from paper ×: Image peels off from paper

As is apparent from the evaluation results in Table 4, all the toners of Examples 5 to 9 of the present invention were excellent in performance evaluation.
On the other hand, Comparative Example 6 using (A′-1) having a glass transition temperature of −38 ° C., Comparative Example 7 using (B′-1) having a glass transition temperature of 81 ° C., (A′-1 ) And (B′-1), Comparative Example 8, X ₀ / X ₁ of 0.90 (C′-4), Comparative Example 9, X ₁ of 0 (C′-5) In Comparative Example 10 used, some performance items were poor.

The toner binder and toner composition of the present invention are compatible with toner fluidity, heat-resistant storage stability, charging stability, grindability, image strength and anti-folding properties while achieving both low-temperature fixability, glossiness and hot offset resistance. It is excellent and useful as an electrostatic charge image developing toner and toner binder used for electrophotography, electrostatic recording, electrostatic printing and the like.

Claims (10)

A mixture of an amorphous polyester resin (A) having a glass transition temperature of −35 ° C. or higher and lower than 45 ° C., an amorphous polyester resin (B) having a glass transition temperature of 45 ° C. or higher and 80 ° C. or lower, and an extender (D) . A toner binder comprising a resin composition (C) obtained by reaction and satisfying the following relational expressions (1) and (2):
0.02 ≦ X ₁ ≦ 0.08 (1)
0.10 ≦ X ₀ / X ₁ ≦ 0.90 (2)
[X ₀ in the relational expression represents the average crosslinking density of the mixture of the polyester resin (A) and the polyester resin (B), and X ₁ represents the average crosslinking density of the resin composition (C). ] The toner binder according to claim 1, wherein the extender (D) contains at least a 3- to 8-valent polyisocyanate compound (D11). Polyester resin (A) and the polyester resin (B) weight ratio of (A) / (B) is 5 / 95-15 / 85 a toner binder according to claim 1 or 2. The toner binder according to any one of claims 1 to 3, wherein the extender (D) is at least one polyisocyanate compound (D111) selected from the group consisting of isocyanurate and biuret. The toner binder according to claim 1, wherein the polyester resin (A) has active hydrogen at the end of the main chain. The toner binder according to claim 1, wherein the hydroxyl value of the polyester resin (B) is 5 KOH mg / g or less. The toner binder according to claim 1, wherein the resin composition (C) has at least one functional group selected from the group consisting of an ester group, a urethane group, a urea group, a biuret group, and an allophanate group. The toner binder according to any one of claims 1 to 7, wherein a volatile content in the resin composition (C) is 100 ppm or less. The toner binder according to claim 1, further comprising a crystalline resin (E). A toner composition comprising the toner binder and the colorant according to claim 1.