JPH05323647A - Additive for developer and developer composition - Google Patents

Abstract

PURPOSE:To improve fixing property of a toner (low temp. fixing property, offset resistance, etc.,) and pulverizing property by incorporating an additive consisting of a specified compd., binder resin and coloring agent. CONSTITUTION:The developer contains an additive consisting of a compd. expressed by formula I, binder resin, and coloring agent. In formula I, A1 and A2 are alkyl groups, alkenyl groups or arylalkyl groups, n is 0 or 1, and X is one group expressed by formula II. In formula II, R1 and R2 are H or alkyl groups of <=4C. In the compd. expressed by formula I, the carbon number of A1 and A2 is not limited, but 6 to 18 carbon number is preferable. If the carbon number of A1 and A2 is <6, the effect to improve fixing property is little, and if the number of carbons exceeds 18, compatibility of the additive with the resin decreases to impair fluidity, electrification property, blocking resistance, etc., of the toner. A1 and A2 are concretely straight-chain alkyl groups such as n-hexyl groups, branched alkyl groups such as 2-hexyldecyl groups, or arylalkyl groups.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to electrophotography, electronic recording,
The present invention relates to a developer additive and a developer composition for developing a blue charge image in electrophotographic printing or the like. More specifically, the present invention relates to an additive for a developer and a developer composition which are improved in toner fixing performance (low temperature fixing property, offset resistance) and pulverizability by being used in an electrophotographic system.

[0002]

2. Description of the Related Art Conventionally, in electrophotography, as described in US Pat. Nos. 2,297,691 and 2,357,809, a photoconductive insulating layer is uniformly charged, and then the layer is exposed. , An electric latent image is formed by dissipating the electric charge of the exposed portion, and further visualized by adhering a fine powder having a colored electric charge called toner to the latent image (developing step) ,
After the obtained visible image is transferred onto a transfer material such as transfer paper (transfer step), it is permanently fixed by heating, pressure or other suitable fixing method (fixing step).
As described above, the toner must have the functions required not only in the developing process but also in the transferring process and the fixing process.

By the way, in recent years, in electrophotographic copying machines, printers and the like, it is strongly desired to provide printed matter of higher speed and higher image quality. Various methods and devices have been developed for fixing a toner image to meet this demand, but the most general method at present is a so-called heat roller fixing method in which heat and pressure are simultaneously applied. In a high-speed copying machine having this fixing method, continuous fixing is performed many times, so a considerable amount of heat from the heat roller is lost to the image support, and heat supply cannot be done in time, resulting in a decrease in the temperature of the heat roller. Then, fixing failure is likely to occur.
Therefore, it is desired to develop a toner that can be fixed at a lower temperature in a high speed copying machine or the like.

The polyester resin has inherently good fixing property, and is sufficiently fixed even in a non-contact fixing system as described in US Pat. No. 3,590,000, but when it is used in the above heat roller fixing system, an offset occurs. The phenomenon was likely to occur and it was difficult to use. The offset phenomenon means that the toner comes into contact with the surface of the heat roller in a molten state at the time of fixing the heat roller, and a part of the melted toner is transferred and adhered to the surface of the heat roller, which is then sent to the image support. It is a phenomenon that re-transfers to the body and stains the image.

Therefore, in a high-speed copying machine or the like having a heat roller fixing system, development of A: toner having excellent offset resistance and B: toner having excellent low temperature fixing property is strongly desired. Conventionally, it has been proposed to use a crosslinked resin as a method for improving offset resistance (Japanese Patent Publication No. 51-23354 and Japanese Patent Laid-Open No. 59-908).
No. 66, Japanese Patent Publication No. 59-11902, etc.). Further, as a method of improving low-temperature fixability while satisfying offset resistance, it has been proposed to introduce a soft segment into a side chain (Japanese Patent Laid-Open Nos. 57-109825 and 59-7960). etc). In addition, a method of adding a low molecular weight polyolefin wax to the toner in order to impart releasability to the fixing roller has also been carried out (Japanese Patent Laid-Open Nos. 49-65232 and 50-28840). Furthermore, it is proposed to use both aromatic bisamide having a molecular weight of 500 to 1500 as a fixing property improving aid to improve the thermal responsiveness of the fixing heat roller so that both fixing property on paper and releasability from the fixing roller can be achieved. (JP-A-2-
986).

[0006]

However, in the above-mentioned technique, the fixing temperature rises only by using a cross-linked resin, and an unfixed portion is generated under normal fixing conditions, which causes problems such as image stains. Occur. In addition, although the above-mentioned technology certainly improves the fixing,
Since the toughness of the resin is improved, the pulverizability of the resin, which is related to the productivity of the toner, is deteriorated, and the productivity of the toner is deteriorated. Further, although the above-mentioned technique is effective in preventing offset, addition of a large amount thereof causes deterioration of charging characteristics due to deterioration of fluidity of the toner. Further, if the added amount is small, it is ineffective. Further, although the above-mentioned technique is effective in improving the fixing property, the aromatic bisamide may reduce the polymerization degree of the binder resin having a functional group such as an ester group and an amide group, and therefore, the developer composition Lot fluctuations occur in the melt viscosity, making it difficult to manufacture a stable developer composition.

The present invention has been made based on the above circumstances, and an object of the present invention is to improve the fixing performance (low temperature fixing property, anti-offset property) and pulverizability of a toner, and an additive for a developer. And to provide a developer composition.

[0008]

The present inventors have completed the present invention as a result of earnest research to achieve the above object. That is, the present invention provides a developer additive characterized by comprising a compound represented by the general formula (1).

[0009]

[Chemical 4]

(Wherein A ₁ and A ₂ are alkyl groups, alkenyl groups or arylalkyl groups, n is 0 or 1, and X is

[0011]

[Chemical 5]

One of the above. Where R ₁ , R ₂
Represents H or an alkyl group having 4 or less carbon atoms. The present invention also provides a developer composition containing an additive comprising a compound represented by the general formula (1), a binder resin and a colorant.

In the compound represented by the general formula (1) according to the present invention, the carbon numbers of A ₁ and A ₂ can be arbitrarily selected. However, it preferably has 6 to 18 carbon atoms. If the carbon number of A ₁ or A ₂ is less than 6, it is less effective in improving fixability.
If it exceeds the range, the compatibility with the resin deteriorates, and the fluidity, chargeability, blocking resistance, etc. of the toner are impaired, which is not preferable. Specific examples of A ₁ and A ₂ include linear alkyl groups such as n-hexyl group, n-octyl group, n-dodecyl group, and n-octadecyl group, and 2-hexyldecyl group and methyl-branched octadecyl group. Branched alkyl group or benzyl group, 2
An arylalkyl group such as a phenylethyl group. The compound represented by the general formula (1) according to the present invention is
General formula (3)

[0014]

[Chemical 6]

(Wherein X and n have the same meanings as described above), NaOH and KOH are added to the aromatic glycol represented by
It can be easily obtained by reacting an alkyl halide and / or an arylalkyl halide under an alkaline catalyst such as. Specific examples of the compound represented by the general formula (1) according to the present invention are as follows.

[0016]

[Chemical 7]

[0017]

[Chemical 8]

The compound represented by the general formula (1) according to the present invention is preferably added in an amount of 0.1 to 10.0% by weight with respect to the binder resin in order to exert its intended performance. .. It is more preferably 0.5 to 8.0% by weight, and even more preferably 1.0 to 5.0% by weight. If the addition amount of the compound represented by the general formula (1) is less than 0.1% by weight based on the binder resin, the effect of improving the fixing property is weak. On the other hand, 10.0% by weight
If it exceeds, the fluidity, chargeability, blocking resistance, etc. of the toner are likely to be impaired, and the offset resistance tends to be deteriorated.

The compound represented by the general formula (1) according to the present invention may be added to the electrophotographic developer composition during or after the production of the binder resin.
When the binder resin, the colorant and, if necessary, the additives used are kneaded, they may be melt mixed.

The compound represented by the general formula (1) according to the present invention is a thermally stable compound which does not emit smoke or color even when it is exposed to a high temperature during the production of the binder resin. At the same time, it is not only a compound that is chemically stable with respect to the esterification catalyst and radical polymerization initiator used in the production of the binder resin, but also with respect to the functional groups such as the ester group and the amide group of the binder resin. Since it does not have any influence, it has an excellent feature that it does not contribute to the decrease of the polymerization degree of the resin and the formation of the low molecular weight component.

The compound represented by the general formula (1) according to the present invention has an alkyl group and the like and an aromatic ring having a large cohesive force in the molecule, and as a result, releasability from a heat roller fixing device is improved. Therefore, it is considered that the toner has the ability to impart the cohesive force of the toner. Further, since the compound has an effect of lowering the melt viscosity of the binder resin, it is considered that the compound also has an effect of lowering the melt viscosity of the toner when passing through the heat roller fixing device and assisting the transfer onto a transfer paper or the like.

As the binder resin used in the present invention, polyester, polyester polyamide or polyamide resin obtained by polycondensation reaction, vinyl resin obtained by addition polymerization reaction and the like are used. Polyester is obtained by using polyhydric alcohol and polyhydric carboxylic acid, polyhydric carboxylic acid ester, polyhydric carboxylic acid anhydride or the like as a raw material monomer, and as a divalent alcohol component of the polyhydric alcohol, The bisphenol A alkylene oxide adduct represented by the following general formula (2) is effective.

[0023]

[Chemical 9]

(In the formula, R ₃ is an alkylene group having 2 to 4 carbon atoms, x and y are positive integers, and the average value of the sum is 2
~ 16. ) Specific examples of the bisphenol A alkylene oxide adduct include, for example, polyoxypropylene (2.2) -2,
2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,
2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.5) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6.0)-
2,2-bis (4-hydroxyphenyl) propane etc. can be mentioned.

As the dihydric alcohol component, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentane. Diol, 1,6
It is also possible to use aliphatic diols such as -hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol and polytetramethylene glycol, and other divalent alcohols.

When the bisphenol A alkylene oxide adduct represented by the above general formula (2) is used as a constituent monomer, a polyester resin having a relatively high glass transition point is obtained due to the properties of the bisphenol A skeleton, and blocking resistance is obtained. It will be good. Also, the bisphenol A skeleton is
Since the molecular weight is large, it contributes to increasing the molecular weight of the polymer and is effective in anti-offset.

Among the monomers constituting the polyester resin in the present invention, examples of the divalent carboxylic acid component include maleic acid, fumaric acid, citraconic acid,
Itaconic acid, glutaconic acid, phthalic acid, isophthalic acid,
Terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, and the following general formula (4) or (5)

[0028]

[Chemical 10]

(Wherein R ₄ and R ₅ are saturated or unsaturated hydrocarbon groups having 4 to 20 carbon atoms), for example, n-dodecylsuccinic acid, n- Dodecenyl succinic acid, n-octyl succinic acid, isododecyl succinic acid, isododecenyl succinic acid, n-octenyl succinic acid, anhydrides or lower alkyl esters of these divalent carboxylic acids, and other divalent carboxylic acids Can be mentioned.

In the developer composition for electrophotography, when offset resistance is particularly required, it is effective to partially crosslink the molecule of the binder resin. Crosslinking can be achieved by using a polyfunctional compound having a valence of 3 or more.
Examples of trivalent or higher polyols as a cross-linking agent include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,
2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,3.
5-trihydroxymethylbenzene or the like can be used.

Examples of tricarboxylic or higher polycarboxylic acids as the cross-linking agent include trimellitic acid, 2,5,5
7-naphthalene tricarboxylic acid, 1,2,4-naphthalene tricarboxylic acid, 1,2,4-butane tricarboxylic acid, 1,2,5-hexane tricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylene Carboxylpropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,
7,8-octanetetracarboxylic acid, pyromellitic acid,
Empor trimer acids, anhydrides or lower alkyl esters of these acids and the like can be used. Trimellitic anhydride is mentioned as a particularly preferable trivalent or higher polycarboxylic acid.

The polyfunctional compound having a valence of 3 or more is 0.5 mol% or more and less than 15.0 mol% of the total amount of monomers, preferably 1.5 mol% or more and less than 12.0 mol%, more preferably 2.5 mol% or more.
Less than 10.0 mol% can be used. The trivalent or higher valent polyols and the trivalent or higher valent polycarboxylic acids can be used either alone or in combination, but if the total amount exceeds 15.0 mol%, the production stability of the polyester resin is deteriorated, which is not preferable. When a polyfunctional compound having a valence of 3 or more is used, if it is used in an amount of less than 0.5 mol% of the total amount of monomers, the effect of offset resistance is scarce.

The polyester resin used in the present invention can be produced by polycondensing a polycarboxylic acid component and a polyol component at a temperature of 180 to 250 ° C. in an inert gas atmosphere. At this time, in order to accelerate the reaction, a commonly used esterification catalyst such as zinc oxide, stannous oxide, dibutyltin oxide, dibutyltin dilaurate or the like can be used. Moreover, it can manufacture under reduced pressure for the same purpose.

As the polyester polyamide or polyamide used in the present invention, a generally known one can be used. Among the raw material monomers for forming the polyester polyamide or the amide component in the polyamide, as the polyamine, for example, ethylenediamine, pentamethylenediamine, hexamethylenediamine, diethylenetriamine, iminobispropylamine, phenylenediamine, xylylenediamine, triethylenetetramine, etc. , Polyamino acid, 6-aminocaproic acid, aminocarboxylic acids such as ε-caprolactam, and amino alcohols such as propanolamine.

As the vinyl resin used in the present invention, a generally known resin can be used. Typical monomers used to form the vinyl resin include, for example, styrene, o-methylstyrene, m-methylstyrene,
Styrene-based monomers such as p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-chlorostyrene and vinylnaphthalene, for example, ethylene-based such as ethylene, propylene, butylene and isobutylene. Unsaturated monoolefins such as vinyl esters such as vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl formate, vinyl caproate, such as acrylic acid, methyl acrylate,
Ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, amyl acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, acrylic acid Decyl, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methoxyethyl acrylate, 2-hydroxyethyl acrylate, glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-
Methyl chloroacrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, N-octyl methacrylate, isooctyl methacrylate, decyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methoxyethyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, phenyl methacrylate, methacrylic acid. Ethylenic monocarboxylic acids such as dimethylaminoethyl, diethylaminoethyl methacrylate, etc. and their esters, eg acrylonitrile, methacrylonitrile , Ethylenic monocarboxylic acid substitution products such as acrylamide, ethylenic dicarboxylic acids such as dimethyl maleate and substitution products thereof, vinyl ketones such as vinyl methyl ketone, vinyl ethers such as vinyl methyl ether, eg vinylidene. There are vinylidene halides such as chloride, and N-vinyl compounds such as N-vinylpyrrole and N-vinylpyrrolidone.

When a crosslinking agent is added, for example, divinylbenzene, divinylnaphthalene, polyethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate,
1,3-butylene glycol dimethacrylate, 1,6
-Hexylene glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4-methacryloxydiethoxyphenyl) propane, 2,2'-bis (4- Acryloxydiethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, dibromoneopentyl glycol dimethacrylate, diallyl phthalate, etc. Two or more kinds can be used in combination). When the amount of these cross-linking agents used is large, the toner is less likely to be melted by heat, resulting in poor heat fixing property or heat pressure fixing property. Further, when the amount used is small, it is difficult to prevent the offset phenomenon in which a part of the toner adheres to the roller surface without being completely fixed to the paper and is transferred to the next paper during heat roller fixing. Therefore, the amount of these crosslinking agents used is preferably 0.001 to 15% by weight (more preferably 0.1 to 10% by weight) based on the polymerizable monomer.

Further, as the polymerization initiator used in producing the vinyl resin, 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1 , 1'-Asobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-
2,4-dimethylvaleronitrile, other azo or diazo polymerization initiators, benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxy carbonate, cumene hydroperoxide, 2,
Examples thereof include peroxide polymerization initiators such as 4-dichlorobenzoyl peroxide, lauroyl peroxide, and dicumyl peroxide. Two or more polymerization initiators may be mixed and used for the purpose of controlling the molecular weight and molecular weight distribution of the polymer, the reaction time or the like. The amount of the polymerization initiator used is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerizable monomer.

The binder resin used in the present invention preferably has a softening point of 95.0 ° C. or higher and 160.0 ° C. or lower as measured by a Koka type flow tester. When the softening point is less than 95.0 ° C, the offset resistance and blocking resistance are impaired, and 160.
If the temperature exceeds 0 ° C, the low temperature fixability will be impaired. The softening point of the binder resin in the present invention by the high-performance flow tester is:
It is defined as follows. That is, using a Koka type flow tester (CFT-500) (manufactured by Shimadzu Corporation),
Die pore diameter 1 mm, pressure 20 kg / cm ² , temperature rising rate 6 ° C / m
The softening point is defined as the temperature corresponding to 1/2 of the height from the outflow start point to the outflow end point when a 1 cm ³ sample is melted out under the in condition.

As another physical property of the binder resin used in the present invention, it is preferable that the glass transition temperature by DSC (Differential Scanning Calorimeter) is 50.0 ° C. or higher and 80.0 ° C. or lower. 50.0
If the temperature is lower than 0 ° C, blocking resistance will be impaired, and if it exceeds 80.0 ° C, low-temperature fixability will be impaired.

As the colorant which can be used in the present invention, for example, in the case of black toner, various carbons produced by the thermal black method, acetylene black method, channel black method, furnace black method, lamp black method, etc. For black and color toners, copper phthalocyanine, monoazo pigments (CIPigme
nt Red 5, CIPigment Orange 36, CIPigment Red 2
2), disazo pigment (CIPigment Yellow 83), anthraquinone pigment (CIPigment Blue 60), disazo pigment (Solvent Red 19), rhodamine dye (Solvent Red 4)
9) etc., and these are used as a binder resin and the above general formula (1).
After sufficiently uniformly dispersed by a ball mill etc. together with a compound represented by, and a positive or negative charge control agent in some cases,
Melt and knead with a kneader, cool and pulverize, average particle size 5 ~
Used as a 15 μm colored powder or toner. As a dry two-component developer, the toner is an amorphous carrier,
It is used as a developer by blending an appropriate amount with magnetic powder such as a ferrite-based carrier and a spherical coating carrier.

The positive charge control agent that can be used in the present invention is not particularly limited from low molecular weight compounds to high molecular weight compounds (including polymers). For example, nigrosine-based dyes “Nigrosine Base EX”, “Oil Black BS”, “Oil Black SO” (above,
Orient Chemical Co., Ltd.), triphenylmethane dye,
Examples thereof include quaternary ammonium compounds and amino group-containing vinyl polymers. Further, as the negative charge control agent that can be used in the present invention, metal complex salts of monoazo dyes, nitrohumic acid and its salts, substances having a nitro group or a halogen element, sulfonated copper phthalocyanine,
Examples thereof include maleic anhydride copolymers.

Further, the magnetic fine powder may be contained in the toner for the purpose of improving the developing mechanism or the image. The magnetic powder may be an alloy or compound containing an element exhibiting ferromagnetism such as ferrite and magnetite. The magnetic powder is in the form of fine powder having an average particle size of 0.05 to 1 μm in the binder resin. An amount of up to 70% by weight can be dispersed and used.

Further, known property improvers contained in the toner according to the present invention include an anti-offset agent, a fluidizing agent, and a heat property improver (eg, 3,5-di-tertiarybutylsalicylic acid chromium complex). There are metal complexes and metal oxides such as zinc oxide), etc., but their use does not impede the present invention.

[0044]

EXAMPLES Examples of the present invention will be described below.
The invention is in no way limited to these examples. The parts in the examples are based on weight.

Production Example 1 (Binder Resin-1) Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 5.0 mol, ethylene glycol 5.0 mol, terephthalic acid 8.0 mol, 1,2,4 -Benzenetricarboxylic acid anhydride (trimellitic anhydride) 1.0
Mol and 5.0 g of dibutyltin oxide in glass
Put in a one-necked flask, attach a thermometer, a stainless stir bar, a down-flow condenser and a nitrogen introduction tube, and under a nitrogen stream in a mantle heater at 190 ° C for 3 hours at 220 ° C.
For 3 hours, at 240 ℃ for 3 hours, and at the same temperature for 60 mmHg
The reaction was terminated under reduced pressure for 1 hour to complete the reaction. The obtained resin was a pale yellow solid, and the softening point by a flow tester was 128 ° C and the glass transition temperature by DSC was 67 ° C. The obtained resin is referred to as Binder Resin-1.

Production Examples 2 to 4 (Binder Resins-2 to 4) Binder resins-2 to 4 were produced in the same manner as in Production Example 1 with the raw material compositions shown in Table 1. Table 1 shows the softening point of the obtained resin by a flow tester and the glass transition temperature by DSC.

[0047]

[Table 1]

Production Example 5 (Binder Resin-5) 550 g of xylene was placed in a 2-liter glass four-necked flask equipped with a thermometer, a stainless stir bar, a downflow condenser, a dropping funnel and a nitrogen introducing tube. After purging with nitrogen, the temperature was raised to 135 ° C. 700 g of styrene, 300 g of butyl methacrylate and 50 g of dicumyl peroxide were placed in a dropping funnel, added dropwise over 4 hours, and aged at 135 ° C for 5 hours. Then, the temperature was raised to 200 ° C., xylene was distilled off under reduced pressure, the mixture was extracted into a vat, cooled, and then pulverized. The softening point by a flow tester was 120 ° C, and the glass transition temperature by DSC was 66 ° C. The obtained resin is referred to as Binder Resin-5.

Production Example 6 (Binder Resin-6) 700 g of styrene and 300 g of butyl methacrylate as monomers of vinyl resin and 50 g of dicumyl peroxide as a polymerization initiator are placed in a dropping funnel. 390 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 120 g of terephthalic acid, 38 g of 1,2,5-benzenetricarboxylic acid and 1 g of dibutyltin oxide were added to 4 g of 5 liters of glass. Put in a two-necked flask, attach a thermometer, a stainless stir bar, a downflow condenser, and a nitrogen introduction tube, and stir at a temperature of 135 ° C under a nitrogen stream in a mantle heater while stirring from the dropping funnel. The vinyl resin monomer and the polymerization initiator were added dropwise over 4 hours. The mixture was aged for 5 hours while maintaining the temperature at 135 ° C, heated, and then reacted at 220 ° C. The degree of polymerization is ASTM E28-67
Followed from the softening point according to the above, when the softening point reached 128 ℃, the reaction was terminated. The resin thus obtained was a pale yellow solid and had a softening point of 125 ° C by a flow tester and a DS
The glass transition temperature by C was 63 ° C. The obtained resin is referred to as Binder Resin-6.

Example 1 Materials having the following compositions were mixed in a Henschel mixer, melt-mixed in a twin-screw extruder, cooled, and then subjected to a usual pulverizing / classifying process to prepare a toner having an average particle size of 10 μm. <Composition> Binder resin-1 100 parts Carbon black (# 44) (manufactured by Mitsubishi Kasei Co., Ltd.) 7 parts Negatively chargeable charge control agent (Bontron S-34, manufactured by Orient Chemical Co., Ltd.) 2 parts Compound of the present invention 2 parts Obtained 39 parts of the toner thus prepared and 1261 parts of iron powder coated with resin were mixed to prepare a developer, and a commercially available electrophotographic copying machine (photoreceptor was amorphous selenium, and the rotation speed of the fixing roller was 255 m).
m / sec, variable the heat roller temperature in the fixing device,
The image was printed using the one with the oil application device removed.
Table 3 shows the results of evaluation of the fixing property of the image, the offset property, the storage stability and the pulverizability of the toner, while controlling the fixing temperature at 120 ° C to 220 ° C.

The minimum fixing temperature here means that the bottom surface is 15 mm ×
A load of 500 g was placed on a 7.5 mm sand eraser, the image fixed through the fixing device was rubbed 5 times back and forth, and the optical reflection density was measured with a reflection densitometer of Macbeth Co. before and after rubbing. The temperature of the fixing roller when the fixing rate exceeds 70%.

[0052]

[Equation 1]

The high temperature offset generation temperature was visually evaluated. For storage stability, see Toner 50
g was evaluated by the degree of aggregation when left for 24 hours at 50 ° C. and 40% relative humidity. That is, when the amount remaining on the 42-mesh screen was less than 3 g, the storage stability was good (good), and when it was 3 g or more, it was bad.

The pulverizability of the toner was evaluated by a simple pulverization test. That is, after melt mixing and cooling with a twin-screw extruder,
Filter the coarsely pulverized toner with a Rotoplex etc.,
A toner powder is obtained which passes 16 mesh and not 20 mesh. 20.00 g of the classified toner powder is precisely weighed, and a coffee mill (HR-2170 type manufactured by PHLIPS)
After crushing for 10 seconds, the powder is passed through a 32 mesh sieve, and the weight (A) g of the toner that does not pass is precisely weighed. The residual rate is calculated by the following formula, and the above operation is performed three times and averaged. The average residual rate is 0 to 15.0% [◎], 15.1 to 20.0% is [○], and 20.1 to 10%.
0% is displayed as [x].

[0055]

[Equation 2]

Examples 2 to 10 and Comparative Example 1 Using the materials having the compositions shown in Table 2, the carbon black used in Example 1, and the negatively chargeable charge control agent, the same operation as in Example 1 was carried out, and the toner and A developer was prepared and its physical properties were evaluated in the same manner. The results are shown in Table 3.

[0057]

[Table 2]

[0058]

[Table 3]

As is clear from Table 3, Examples 1-10
The developer composition of the present invention obtained in 1. had a low minimum fixing temperature, good storage stability, and good pulverizability of the toner. However, in the developer composition obtained in Comparative Example 1, since the compound of the present invention was not added, the pulverizability of the toner was poor and the minimum fixing temperature was also high.

[0060]

The developer composition for electrophotography of the present invention contains a thermally and chemically stable compound represented by the general formula (1). Therefore, due to the effect of the compound, the toner fixing performance ( It has excellent properties such as low-temperature fixability and anti-offset property, and further improves toner pulverizability.

Claims (6)

[Claims] 1. An additive for a developer, which comprises a compound represented by the general formula (1). [Chemical 1] (In the formula, A ₁ and A ₂ are alkyl groups, alkenyl groups or arylalkyl groups, n is 0 or 1, and X is Is one of: Here, R ₁ and R ₂ represent H or an alkyl group having 4 or less carbon atoms. ) 2. A developer composition comprising the additive according to claim 1, a binder resin, and a colorant. 3. The developer composition according to claim 2, wherein the ratio of the additive according to claim 1 to the binder resin is 0.1 to 10.0% by weight. 4. The developer composition according to claim 2, wherein the binder resin is at least one selected from polyester, polyester polyamide, and polyamide. 5. The developer composition according to claim 4, wherein the binder resin is a polyester having a diol component represented by the general formula (2) as a constituent unit monomer. [Chemical 3] (In the formula, R ₃ is an alkylene group having 2 to 4 carbon atoms, x,
y is a positive integer, and the average value of the sum is 2-16. ) 6. The developer composition according to claim 2, wherein the binder resin is a vinyl resin.