JPS59189357A - Toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To enlarge fixing temp. range and to render offset occurrence temp. to a suitable height by using a binder made of a polyester contg. substd. aminopolycarboxylic acid represented by a specified general formula as monomer units. CONSTITUTION:A binder uses a polyester obtained by reacting a polyol with a substd. aminopolycarboxylic acid monomer represented by formula I in which R1-R4 are each H, OH, alkyl, aryl, carboxyalkyl, or carboxyaryl, and at least 2 of them have carboxylic groups, and R6 is an org. linking bond. The polyester contains a component insoluble in chloroform. Said substd. aminopolycarboxylic acid is exemplified by ones having structural formulae II, III. As said polyol, diols, etherified bisphenopls, and other diol monomers can be enumerated. A content of said polycarboxylic acid in the polyester can be changed in a wide range.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a toner for developing electrostatic images formed in electrophotography, electrostatic printing, electrostatic recording, and the like.

(Prior art) In the process of developing an electrostatic image, charged fine particles are attracted by electrostatic attraction and attached to the surface of an electrostatic image support.
This is the process of visualizing the electrostatic charge image.

The specific method for carrying out such a developing process is as follows:
A wet development method using a liquid developer in which pigments or dyes are finely dispersed in an insulating organic liquid, and a powder consisting of a toner in which a coloring agent such as carbon black is dispersed in a binder made of a natural or synthetic resin. There are dry developing methods such as the cascade method, the bristle brush method, the magnetic brush method, the impression method, and the powder cloud method, which use a body developer.

The image visualized in the developing step may be fixed as is on the support, but usually it is transferred to another image carrier such as transfer paper and then fixed. In this way, the toner is not only subjected to the development process, but also to the subsequent processes, that is, the transfer process and the fixing process, so the toner has not only good developability but also the following processes: It is required to have good transfer and fixing properties. Among these, the conditions related to fixing properties are the most severe, and many studies and results have been published in the past on improving the fixing properties of this toner.

It is generally advantageous to use a heat fixing method to fix the toner image formed in the developing process or the image transferred thereto.This heat fixing method includes a non-contact heat fixing method such as oven fixing, and a heat roller fixing method. There are contact heating fixing methods such as The contact heat fixing method is excellent in that it has high thermal efficiency, and is particularly capable of high-speed fixing and is suitable for fixing in high-speed copying machines. Furthermore, since a relatively low-temperature heat source can be used, this method requires less power consumption, making it possible to downsize the copying machine and save energy. Further, even if paper accumulates in the fixing device, there is no risk of fire, which is also preferable.

Although the contact heat fixing method is preferable in various respects as described above, this method has a serious problem of occurrence of the offset phenomenon. This is a phenomenon in which a portion of the toner constituting the image is transferred to the surface of the heat roller during fixing, and this is transferred again to the transfer paper or the like that is fed next, staining the image. In order to prevent this offset phenomenon, various proposals have been made in the past, and some of them have been put into practical use. One is to perform fixing while applying a release oil such as silicone oil to the surface of a heated roller, and the other is to provide the toner itself with anti-offset performance. The latter method is superior in that the structure of the fixing device is simple because a silicone oil application mechanism and the like are not required, and maintenance such as replenishment of silicone oil is not required.

The offset phenomenon occurs when the temperature of the heat roller increases, and therefore, the higher the minimum temperature at which the offset phenomenon occurs (hereinafter referred to as "offset occurrence temperature"), the better the non-offset properties of the toner. However, in order to fix the toner, it is necessary to heat it to a temperature above its softening point. Therefore, in an actual heat roller fixing device, the temperature of the heat roller is set at a temperature higher than the softening point of the toner. The temperature is set to a specific temperature within the fixable temperature range that is higher than the offset temperature and lower than the offset generation temperature.

However, in reality, it is not possible to maintain the temperature of the heat roller completely uniformly at the set temperature, and there are other temperature-related circumstances that must be taken into consideration. It is desirable to have a toner that does not impair the advantages of the contact heat fixing method.

Vinyl polymers have traditionally been widely used as binders for toners, and in order to obtain non-offset properties in toners using vinyl polymers as binders, it is desirable to use polymers with high molecular weight. Although it has been proposed, high molecular weight vinyl polymers have a high softening point, and therefore it is difficult to obtain a wide fixing temperature range even if the offset and toner generation temperature is high, making it impossible to obtain a suitable toner. .

On the other hand, polyester resin can be relatively easily obtained in the form of a low molecular weight material, so it is possible to use it as a binder to obtain a toner with a low softening point. Compared to toners made from vinyl polymers, which have a softening point approximately equal to 1, they "wet" well to image carriers such as transfer paper when melted, and perform sufficient fixing at lower temperatures. This is preferable because it can be done.

Furthermore, since toner is attached to an electrostatically charged image carrier using electrostatic attraction, or is further transferred to another image carrier, it is generally necessary to have uniform and stable triboelectric charging properties. be. The general method of imparting triboelectricity to toner is to include a charge control agent such as a dye in the resin particles constituting the toner, or to provide the resin itself with an appropriate amount of triboelectricity. , $). When a polyester resin is used as a binder, the polyester resin itself has negative chargeability, and therefore, in order to use it as a positively chargeable toner, it is necessary to contain a charge control agent.

Conventional charge control agents for imparting positive chargeability to toner include, for example, nigrosine dyes, quaternary ammonium compounds (Japanese Unexamined Patent Publication No. 49-51951), amine compounds (
JP-A-49-12F126, JP-A-51-53628), triphenylmethane basic dyes (JP-A-51-1986)
No. 11455), lake pigment (JP-A-52-113)
No. 738, No. 52-113739) are known, and the nigrosine dye is particularly preferred.
It is put into practical use.

However, these charge control agents are easily decomposed or altered by mechanical friction or impact, changes in temperature and humidity conditions, electric shock or light irradiation, melt kneading, etc., or are difficult to disperse uniformly in the inder resin. The amount of triboelectric charge of the toner obtained by the process is insufficient, or it is difficult to stably obtain a uniform positive charge on the surface of the toner particles, resulting in capri and trailing phenomena during development, making it impossible to obtain clear images, etc. There are some drawbacks.

(Object of the Invention) The present invention has been made based on the above-mentioned circumstances. The resin is used as a binder, and the toner itself has positive triboelectric charging properties. Therefore, it is not necessary to add organic dyes or the like to impart good triboelectrification properties, or the amount added is significantly reduced, and as a result, The object of the present invention is to provide a toner for developing electrostatic images with positive triboelectrification properties that does not cause fluctuations in triboelectrification properties or deterioration of image forming properties due to poor dispersion of organic dyes, decomposition and alteration, etc. .

The present invention has been completed as a result of intensive research to achieve this objective.

(Structure of the Invention) The present invention provides a toner for developing electrostatic images containing a binder resin and a colorant, in which the binder resin is a polyester containing a substituted amine polycarboxylic acid represented by the following general formula as a monomer. A toner for developing an electrostatic image, characterized in that:

In the general formula, R, , R, , R, and R4 are each selected from a hydrogen atom, a hydroxyl group, an alkyl group, an aryl group, a carboxylalkyl group, or a carboxylaryl group, and all groups are the same. However, at least two of R1j R2p R31R4 have a carboxyl group.

Horse also represents an organic linking group.

The alkyl group is a lower alkyl group having 1 to 4 carbon atoms which may have a substituent, and is preferably a methyl group or an ethyl group. The aryl group is an aryl group which may have a substituent, and is preferably a 9-phenyl group. Preferably, the carboxyl alkyl group has 1 to 4 carbon atoms, and methyl and ethyl groups are particularly preferable. Preferred among the carboxylaryl groups are carboxylphenyl and carboxylbenzyl groups.

The organic linking group represented by R2 is -Cfi-CH
Examples include t-1. Here, R6 is the above-mentioned R1v k
t A group selected from the same range as Rs and R6.

Specific examples of substituted amine polycarboxylic acids useful in the present invention represented by the above general formula include those having the following structural formula, but the substituted amine polycarboxylic acids of the present invention are limited by this: isn't it.

Exemplary compound 10- 01) 02) 03) 04) (8) σ9) 13- @) 31) cm3 HOCOCH, -N-C1(CH, -N-COOH]
I H1 ■) CH2OH3 @) HOCOCH, -N-CH, CH, -N-CH, C0O
HI C, H, C, H.

2) 14- (Support)) (C) The polyester according to the present invention is a monomer of polycarboxylic acids such as other di- or tricarboxylic acids in combination with the substituted amine polycarboxylic acid represented by the above general formula. It may be contained as

Examples of the dicarboxylic acid used in combination with the substituted amine polycarboxylic acid include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, co/- Examples include phosphoric acid, adipic acid, sepatic acid, malonic acid, anhydrides of these acids, dimers of lower alkyl esters and liluic acid, and other bicyclic organic acid monomers.

Furthermore, examples of polycarboxylic acid monomers having tribasic acids or higher include 1,2,4-benzene) IJ carboxylic acid, 1,2
．． 5-benzenetricarboxylic acid, 1°2.4-cyclohexanetricarboxylic acid, 2,5°7-naphthalenetricarboxylic acid, 1. ．． 2,4-1'phthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2.5-
Hexanetricarboxylic acid, 1,3-dicarboxyl-2
-Methyl-2-methylenecarboxylpropane, tetra(methylenecarboxyl)methane, 1,2,7.8-octanetetracarboxylic acid, Empol trimer acid, acid anhydrides thereof, and others.

The polyester resin used as a binder in the present invention is obtained by condensation of polyhydric alcohol and polycarboxylic acid 7, but the alcohol used is
For example, diols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, ], 4-butanediol, neopentyl glycol, 1,4-butynediol, 1,4-bis(hydroxymethyl)
Cyclohexane and bisphenol A, hydrogenated bisphenol A, polyoxyethylated bisphenol A,
Examples include etherified bisphenols such as polyoxypropylenated bisphenol A, and other dihydric alcohol monomers.

Furthermore, it is also suitable to use a polymer containing not only the above-mentioned difunctional polyhydric alcohol monomer but also a trifunctional or higher polyfunctional monomer.

Examples of such polyfunctional monomers, such as trivalent or higher polyhydric alcohol monomers, include sorbitol, 1°2.3.6
-hexanetetrol, 1,4-sorbitan, pentaerythritol, cichentaerythritol, tripentaerythritol, sucrose, 1゜2.4-butanetriol,
1,2,5-, pentanetriol, glycerol, 2
-Methylpropanetriol, 2-methyl-1,2,4
-butanetriol, trimethylolethane, trimethylol-17-propane, 1,3.5-)lyhydroxymethylbenzene, and others.

In the present invention, a polyester resin obtained by reacting a substituted amine polycarboxylic acid monomer having a structure represented by the above general formula with a polyhydric alcohol monomer is used as a binder. The content of the substituted amine polycarboxylic acid in the polyester according to the invention can vary over a wide range, but is generally about 1% of the total polycarboxylic acid component used when the substituted amine polycarboxylic acid is a dicarboxylic acid. mol % or more, in the case of tricarboxylic acids, from about 1 to about mol % of the total polycarboxylic acid components used, in the case of tetra or more polycarboxylic acids, from about 1 to about 70 mol % of the total polycarboxylic acid components used The content is preferably 3 to 50 mol% for dicarboxylic acids, 3 to 40 mol% for tricarboxylic acids, and 3 to 35 mol% for polycarboxylic acids of tetra or more.

If a polyester resin 18- in which the content of substituted amine polycarboxylic acid is less than 1 mol% of the total polycarboxylic acid components is used, the resulting toner will not have stable positive triboelectric chargeability, and if the polyester resin exceeds the above range If used, the toner has a high softening point, making it impossible to ensure good fixing.

Furthermore, the polyester resin used in the present invention preferably has a chloroform-insoluble content of 5 to 25% by weight. The chloroform-insoluble content herein refers to the content that does not pass through a filter paper when a sample is dissolved in chloroform, and is determined by K as follows.

Finely pulverize the resin sample, collect 5.00 g of sample powder that passed through a 40 mesh sieve, and add the filter aid Radiolye) #=
700 (manufactured by Showa Chemical Industries) 5.00g and capacity 15
Place in a 0M container and add 100g of chloroform in this container.
was injected, placed on a ball mill stand, and rotated for 5 hours or more to sufficiently dissolve the sample in chloroform.

On the other hand, place a 7-diameter filter paper (A2 size) in the pressure filter, pre-coat it with 5.0 ([7] Radiolite evenly, add a small amount of chloroform, and tightly seal the filter paper to the filter. After that, the contents of the container are poured into a filter.The container 19- is thoroughly washed with 100M chloroform and poured into a filter to prevent any deposits from remaining on the walls of the container. After that, close the top lid of the filter and perform filtration.Filtration is performed under pressure of 4 kg/ffl or less, and after the outflow of chloroform has stopped, add 100 ml of chloroform.
is added to wash the residue on the filter paper, and pressure filtration is performed again.

After the above operations are completed, the filter paper, the residue on it, and the radiolite are all placed on aluminum foil and placed in a vacuum dryer at a temperature of 80-100'C.

The mixture was dried under a pressure of 100 mmHg for 10 hours, the total weight of the dried product thus obtained was measured, and the chloroform-insoluble content X (wt%) was determined from the following formula.

X (wt%) The chloroform-insoluble content determined in this way is a high molecular weight polymer component or a crosslinked polymer component in the polyester resin, and its molecular weight is approximately 200,000 or more. it is conceivable that.

The proportion of the above-mentioned chloroform-insoluble components can be controlled to a considerable extent by appropriately selecting the reaction conditions or by allowing an appropriate crosslinking agent to exist in the reaction system in the polymerization reaction between alcohol and carboxylic acid mentioned above. can be formed with.

In the present invention, the binder is preferably a polyester resin having a chloroform-insoluble content of 5 to 25% by weight. However, when a polyester resin having a chloroform-insoluble content of less than 5% by weight is used, the resulting toner has a low offset generation temperature. In addition, if more than 5% by weight of polyester resin is used, the toner may have a high softening point, and in such cases it may not be possible to obtain a wide fixable temperature range, or It is not possible to ensure proper fixation.

The toner of the present invention uses the above-mentioned polyester resin as a binder, and contains a colorant and a property improver added as necessary, and is used together with the colorant or in the case of forming a magnetic toner. Instead, a magnetic substance is contained.

Coloring agents include carbon bra, lye, and nicrosine dye (
C, I, Ya50415B), Aniline Blue (C, 1
, A30405), Calco Oil Blue (C, LAaz
OEC Blue 3), Chrome Yellow (C, 1,
A14090), Ultramarine Blue (C01,A
77103), DuPont Oil Red (C, 1,
A26105), quinoline yellow (C, I, flat 47
005), methylene blue chloride)” (C,1,A
! 52015), Phthalocyanine Blue (C.

I.A 74160), malachite green off-salate (C,1,A42000), lamp black (C,I.A 77266), rose bengal (C,
1, A45435), mixtures thereof, and others. These colorants need to be contained in a sufficient proportion to form a visible image with sufficient concentration, and are usually 1 to 40 parts by weight per 100 parts by weight of the binder. . .

The magnetic material may be a ferromagnetic metal or alloy such as ferrite, magnetite, iron, cobalt, nickel, or a compound containing these elements, or a material that does not contain a ferromagnetic element but is subjected to appropriate heat treatment. Alloys that exhibit ferromagnetic properties, such as manganese-copper-
Aluminum, a type of alloy called Heusler alloy containing manganese and copper such as manganese-copper-tin, chromium dioxide, and others may be mentioned. These magnetic substances are uniformly dispersed in the binder in the form of fine powder with an average particle size of 0.1 to 1 micron. The content thereof is 20 to 70 parts by weight, preferably 40 parts by weight, per 100 parts by weight of toner.
~70 parts by weight.

In addition, the property improving agent improves toner fluidity, non-filming property, that is, property that does not cause filming caused by a part of toner adhering to the surface of a carrier or an electrostatic image, pulverizability, charging property, etc. These substances include resins. Preferably used resins are, for example, uncrosslinked polymers that do not contain chloroform-insoluble components, such as styrenes such as styrene and parachlorostyrene, vinylnaphthalene, evaporated vinyl chloride, vinyl bromide, and fluorinated resins. Vinyl esters such as vinyl, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, e.g. methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate ,
2-chloroethyl acrylate, phenyl acrylate, α
- Methylene aliphatic carboxylic acid esters such as methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, such as vinyl methyl ether, vinyl imbutyl ether, vinyl ethyl ether Vinyl ethers, such as vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, etc., such as N-vinylpyrrole, N-vinylcarbasol, N-
Homopolymers obtained by polymerizing vinyl indole, N-vinyl compounds with N-vinylindole, and other monomers, or copolymers obtained by copolymerizing two or more of these monomers, or the like. or a mixture of, for example, a rosin-modified phenol-formalin resin,
Examples include non-vinyl resins such as non-vinyl thermoplastic resins such as oil-modified epoxy resins, polyurethane resins, cellulose resins, and polyether resins, or mixtures thereof with the above-mentioned vinyl resins.

These resins can be contained in a content ratio of not more than % of the weight of the binder as long as the effects of the present invention are not impaired.

(Examples) Examples of the present invention will be described below, but the present invention is not limited thereto.

Before describing Examples, the synthesis of polyester resins related to the present invention and comparative polyester resins used in Examples will be described.

Synthesis Example 1 Terephthalic acid 166g, Exemplary Compound (1) 1179,
Polyoxypropylene 2,2-2,2-bis(4-
211 g of (hydroxyphenyl)propane and 829 g of pentaerythritol were placed in a round-bottomed flask equipped with a thermometer, a Steffles steel stirrer, a glass nitrogen gas inlet tube, and a flow-down condenser, and the flask was placed in a mantle heater. The flask was set, and nitrogen gas was introduced from the 91J-1j gas inlet tube to raise the temperature while keeping the inside of the flask in an inert atmosphere. and 0.05. ! Diptyltin oxide of ii' was added, and the reaction was allowed to proceed at 200° C. while monitoring the reaction at the softening point, thereby producing polyester resin A having a chloroform-insoluble content of 17% by weight. °The ring and ball softening point of this polyester resin A (JISK2531
- According to the method of 1960.

The same applies below. ) was 130°C.

Synthesis Example 2 Isophthalic acid 166g, Exemplary Compound (1,) 117
fl, polyoxypropylene 2.2-2.2-bis(4
-Hydroxyphenyl)furopane211. ! i' and 74 g of glycerol were reacted at a temperature of 180° C. in the same manner as in Synthesis Example 1 to produce polyester resin B having a chloroform-insoluble content weight % and a ring and ball softening point of 134° C.

Synthesis Example 3 270 g of 26-1,4-butanediol, 150 g of terephthalic acid
9. Using 321 g of Exemplified Compound (2), the reaction was carried out in the same manner as in Synthesis Example 1 at a temperature of 200°C to produce a polyester resin C having a chloroform-insoluble content of 11% by weight and a ring and ball softening point of 127°C.

Synthesis Example 4 Triethylene glycol 300g, inphthalic acid 182g
g, exemplified compound (41,201 g was used and reacted at a temperature of 200°C in the same manner as in Synthesis Example 1, and the chloroform-insoluble matter 1
A polyester resin containing 5% by weight and having a ring and ball softening point of 128°C was produced.

Synthesis Example 5 Terephthalic acid 133g, Exemplary Compound (16) 176
g, polyoxypropylene 2.2-2.2-bis(4-
Using 211 g of hydroxyphenylfuropane and 82 g of pentaeryth IJ)-ru, the reaction was carried out at a temperature of 200°C in the same manner as in Synthesis Example 1 to produce polyester resin E having a chloroform insoluble content of 14% by weight and a ring and ball softening point of 128°C. did.

Synthesis Example 6 1,4-butanediol 270g, Exemplary Compound (20)
271 g of benzene-1,2,4-)licarboxylic acid anhydride, and the same procedure as in Synthesis Example 1 was carried out at a temperature of 200 g.
A polyester resin F having a chloroform insoluble content of 13% by weight and a ring and ball softening point of 130'C was produced by reaction at 1-.

Synthesis Example 7 1,4-butanediol 270g, terephthalic acid 150g
Synthesis Example 1 using 303 g of Exemplified Compound (5)
The reaction was carried out in the same manner as above at a temperature of 200°C to produce polyester resin G having a chloroform insoluble content of 15% by weight and a ring and ball softening point of 132°C.

Synthesis Example 8 Triethylene glycol 300g, inphthalic acid 182g
9, 51 g of benzene-1,2,4-)licarboxylic acid and 117 g of Exemplary Compound (12) were reacted in the same manner as in Synthesis Example 1 at a temperature of 200°C, resulting in a chloroform insoluble content of 16% by weight and a ring and ball softening point of 129. Polyester resin H at °C
was manufactured.

Synthesis example 9 1,4-butanediol isog, terephthalic acid 224
g, 133 g of Exemplified Compound (6) was reacted in the same manner as in Synthesis Example 1, and the chloroform insoluble content was 10% by weight,
A polyester resin material having a ring and ball softening point of 129°C was produced.

Comparative Synthesis Example 1. 270 g of 4-butanediol, 15 g of terephthalic acid
0g, benzene-1,2,4-)licarboxylic anhydride 2
Using 31 g, the reaction was carried out in the same manner as in Synthesis Example 1 to produce polyester resin J having a chloroform-insoluble content of 12% by weight and a ring and ball softening point of 128°C.

Example 1 Carbon black (
10 parts by weight of Regal 660R (manufactured by Cavo, Inc.) were melt-kneaded in a roll mill, cooled, and pulverized in a jet mill.The resulting fine powder was classified with a zigzag classifier to obtain an average particle size of 1.
A 0μ toner of the present invention was produced.

This is referred to as 1 sample 1.

Examples 2 to 9 A total of 8 types of toners of the present invention were produced in the same manner as in Example 1 using each of the polyester resins B to ①. These are respectively "sample 2", "sample 3", "sample 4",
They are referred to as "Sample 5,""Sample6,""Sample7,""Sample8," and "Sample 9."

Example 10 The weight ratio of polyester resin A and styrene-acrylic resin (manufactured by Sanyo Chemical Industries, Ltd., Hymer SBM73) was 8:2.
A toner of the present invention was produced in the same manner as in Example 1 using resins mixed in the following proportions.

This will be referred to as "sample 10."

Example 11 The weight ratio of polyester resin B and styrene-acrylic resin (manufactured by Sanyo Chemical Industries, Ltd., Hymer SBM73) was 9:1.
A toner of the present invention was produced in the same manner as in Example 1 using resins mixed in the following proportions.

This is referred to as 1 sample 11.

Comparative Example 1 A comparative toner was produced in the same manner as in Example 1 using Polyester Resin J. This will be referred to as "comparative sample 1."

Comparative Example 2 5100 parts by weight of polyester resin, carbon black (
Regal 660 R (manufactured by Capoato) 10 parts by weight,
Nigrosine dye (Orient Chemical, Oil Bra, Ri S
A comparative toner was produced in the same manner as in Example 1 using 2 parts by weight of O). This will be referred to as "comparative sample 2."

Comparative Example 3 Comparison was made in the same manner as in Example 1, using 100 parts by weight of polyester resin J, 10 parts by weight of carbon bran resin (manufactured by Cabo To Co., Ltd., Reinol 660 R), 2 parts by weight of ethylenediaminetetraacetic acid and thorium zinc. A toner for use was manufactured. This is referred to as [Comparative Sample 3].

Comparative Example 4 A comparative toner was produced in the same manner as in Example 1 using the holder. This will be referred to as "comparative sample 4."

Example A styrene-methyl methacrylate copolymer was synthesized by reacting styrene and methyl methacrylate at a weight ratio of 30 to 0, and 12 g of this copolymer was used to prepare spherical iron powder with an average particle size of 100 μm (manufactured by Dowa Iron Powder Industries Co., Ltd.). , DSP135C) 1kFI
A carrier was manufactured by forming a coating layer with a thickness of about 2 μm using the fluidization method.

2 parts by weight of each of Samples 1 to 11 produced in Examples 1 to 11 and Comparative Samples 1 to 4 produced in Comparative Examples 1 to 4 were mixed with 98 parts by weight of this carrier to develop a total of 15 types. A toner was prepared, and the charge amount of the toner was measured by a conventional blow-off method.

As shown in Table 1, the substituted aminopolycarbodies 2 to 4 of the present invention
All of them showed positive triboelectric charging properties, but Comparative Sample 1 using a normal polyester resin showed negative triboelectrification properties.

Table 1 Next, we used a heated roller whose surface layer was made of Teflon (manufactured by DuPont, polytetrafluoroethylene).

33- Silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd., KE-13,0
Equipped with a fixing device consisting of a pressure roller formed by ORTV), it has a negatively chargeable two-layer structure using an anthrone pigment as the CGM (carrier generation layer) and a carbazole derivative as the C'l'M (carrier transport layer). An electrostatic charge image was formed by a normal electrophotographic method by applying each of the 14 types of developers having a positive toner charge amount by the blow-off method to a U-Bix 3000 modified machine equipped with an OPC photoreceptor. Develop the toner image, transfer the formed toner image onto plain paper, fix it in a fixing device, then send a blank sheet of paper to the fixing device under the same conditions and observe whether or not toner stains occur on it. The temperature at which the offset occurred was determined by repeatedly changing the set temperature of the heat roller of the fixing device in various ways.

The results are shown in Table 2 together with the evaluation of fixing properties, and Samples 1 to 11 and Comparative Samples 2 to 3 in which polyester resin was used as a binder all had high offset generation temperatures and good fixing properties. On the other hand, sample 4 of hl [Sample 4], which uses styrene-acrylic resin as a binder, had an extremely low offset generation temperature and could not be practically fixed.

Table 2 In the table, "insoluble matter" represents the chloroformin insoluble matter, and "softening point" represents the ring and ball softening point.

Further, when 20,000 sheets were continuously copied using 13 types of developers containing the polyester resin as a binder, 20,000 sheets were copied in each case when Samples 1 to 11, which are toners of the present invention, were used. Clear images with no fog were obtained even after the test, there was no developer fatigue, no toner scattering, and no equipment contamination. On the other hand, when comparative samples 2 and 3 were used, s, ooo
After copying and copying 6,000 sheets, soil burri occurs,
Moreover, toner scattering occurred.

As is clear from the above results, Samples 1 to 11, which are toners of the present invention, all have stable positive chargeability, high offset generation temperature, and good fixing properties.

On the other hand, Comparative Sample 1, which uses the polyester resin of the present invention that does not contain a carboxylic acid-substituted amine, has negative triboelectrostatic properties. Comparative samples 2 and 3 containing and dispersing zinc exhibited sufficient positive triboelectric chargeability initially, but fogging occurred after continuous copying and did not exhibit stable positive chargeability.

Furthermore, Comparative Sample 4, which uses styrene-acrylic resin as a binder, had an extremely low offset generation temperature and could not be practically fixed.

(Effects of the Invention) The toner of the present invention can be obtained by incorporating a polyester resin whose binder has a specific structure represented by the above general formula and a polyester resin having recarboxylic acid as a monomer. As is clear from the explanations of Examples and Comparative Examples, the toner itself has stable positive triboelectric charging properties, a low softening point and a high offset generation temperature, and furthermore, these temperature points are at an appropriate high temperature. Therefore, a wide and high suitable fixing temperature range can be obtained. As a result, the conditions for controlling the temperature of the heat roller of the fixing device in order to achieve sufficient fixing without causing offset phenomenon are greatly relaxed, and the offset phenomenon caused by unevenness of the temperature of the heat roller can be prevented. This makes it possible to always achieve good fixing without any imperfections.

-Haichi

Claims (1)

[Claims] (1) A toner for developing electrostatic images containing a binder resin and a colorant, characterized in that the binder resin is a polyester containing a substituted amine polycarboxylic acid represented by the following general formula as a monomer. Toner for developing electrostatic images. General formula (wherein R1t R2+ R3 and R4 are each selected from a hydrogen atom, a hydroxyl group, an alkyl group, an aryl group, a carboxyl alkyl group, or a carboxyl aryl group, and all groups may be the same or different. However, at least two of R,, R2゜RIl, and R4 have a carboxyl group. Also, R5 represents an organic linking group.) (2) When the substituted aminopolycarboxylic acid is used as a monomer, The toner for developing an electrostatic image according to claim 1, wherein the polyester contains 5 to 25% by weight of chloroform-insoluble matter.