JP2002072538A - Electrostatic latent image developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic latent image developing toner, which will not impair properties related to forming on a photoreceptor, fixing property and offset property and which shows good fixing property of a black solid image against rubbing; after being fixed and which can form proper copied images without crests. SOLUTION: The electrostatic latent image developing toner, comprising essentially polyester resin prepared by the reaction of polybasic acid dicarboxylic acids and polyhydric alcohol diols, contains nonoxidizing polypropylene and oxidizing polyethylene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic latent image developing toner used for electrophotography and the like.

[0002]

2. Description of the Related Art Polyester resins have the advantage of being excellent in low-temperature fixing properties, having appropriate triboelectric charging properties, and capable of preventing filming in the case of a transfer system using a photoreceptor. However, during heating and fixing, there is a disadvantage that a so-called offset phenomenon occurs in which the toner adheres to the fixing roll. Therefore, an anti-offset agent such as a low molecular weight polyolefin resin, a Teflon (registered trademark) resin, or paraffin is generally added to the polyester resin. However, all of the conventional anti-offset agents have low compatibility with the polyester resin and cannot sufficiently prevent the offset phenomenon. In addition, the anti-offset agent is present in the toner as fine particles, and a part of the anti-offset agent is exposed to light. There is a disadvantage that the advantage of preventing filming provided by the polyester resin is adversely affected, such as fusing to a body or coating of a carrier to make charging uneven.

For this reason, JP-A-59-129863 discloses an oxidized polyolefin as a toner capable of sufficiently improving the fixing offset preventing effect without lowering the filming preventing effect of the polyester resin. Has been proposed in which the oxidized polyolefin has an acid value of 1 or more. In other words, in this toner, as the anti-offset agent, an oxidized polyolefin having a polarity is used instead of the conventional non-polar one, and the oxidized polyolefin is added to an inherently polar polyester resin. The compatibility between the two becomes good, the added oxidized polyolefin can be reliably prevented from being fused to the photoreceptor or coated on the carrier, and the filming prevention effect of the polyester resin can be exhibited well. In addition, there is an effect that the occurrence of the offset phenomenon can be favorably prevented.

[0004]

However, in a combination of an acid-modified polyolefin and a general polyester resin, the compatibility is too good and the polyolefin is too finely dispersed. There is a problem in that the releasability of the paper becomes insufficient, and particularly when a solid black image is present at the leading end of the image, a paper jam occurs remarkably. In addition, although the effect of the offset phenomenon is recognized to some extent, the binding property between the toner and paper is good, but the smoothness of the black solid image surface after fixing, the so-called rubbing fixability, is inferior, and multiple copies are repeated. In the combined business materials and the like, when browsing the materials by turning over the papers, papers rub against each other, causing problems such as toner set-off and back stains. Further, in an experiment by the present inventors, the acid value of oxidized polyethylene, which is an oxidized polyolefin, was 1.0 mgKOH /
If the amount is not less than 15 gKOH / g and less than 15 mgKOH / g, the compatibility with the polyester resin can be improved to some extent. ) Occurs. Although the cause is still unclear, it does not occur in non-oxidized polypropylene, and the acid value of non-oxidized polyethylene and oxidized polyethylene is 15 mg.
It is considered to be caused by free polyethylene having a specific particle diameter from the toner or a very charged polyethylene-rich toner, since it is significantly generated at a KOH / g lower than that.

Therefore, according to the present invention, a toner capable of forming a good copy image without crests, without impairing filming, fixing properties and offset properties on a photoreceptor, having a good black solid image fixability after fixing, and a good crest-free image. The task is to provide

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above-mentioned circumstances, and as a result, have found that a polyester resin produced by reacting a polycarboxylic acid dicarboxylic acid with a polyhydric alcohol diol is a main component. In the toner for developing an electrostatic latent image, a non-oxidized polypropylene and an acid value of 15 mg
It has been found that a good toner can be obtained by incorporating oxidized polyethylene having a KOH / g or more, and the present invention has been completed.

That is, the present invention resides in (1) to (12). (1) In an electrostatic latent image developing toner mainly composed of a polyester resin formed by reacting a dicarboxylic acid of a polybasic acid with a diol of a polyhydric alcohol, a non-oxidized polypropylene and an acid value of 15 mgKOH / g. or more of an oxidized polyethylene. (2) The electrostatic latent image developing toner according to (1), wherein the non-oxidized polypropylene is contained in an amount of 0.5 to 5% by weight based on the total weight of the toner. (3) The toner for developing an electrostatic latent image according to (1) or (2), wherein the non-oxidized polypropylene has a loose apparent specific gravity AD of 0.6 g / cc or less. (4) The electrostatic latent image development as described in any of (1) to (3) above, wherein the oxidized polyethylene is contained in an amount of 0.5 to 5.0% by weight based on the total weight of the toner. For toner. (5) The acid value of the polyester resin is 15 to 35 m
The toner for developing an electrostatic latent image according to any one of the above (1) to (4), wherein the toner is gKOH / g. (6) The softening point Tm of the polyester resin is 110
The toner for developing an electrostatic latent image according to any one of the above (1) to (5), wherein the toner temperature is from 140 to 140 ° C. (flow tester constant temperature heating method). (7) The glass transition temperature (T
g) is 45 to 70 ° C., the toner for developing an electrostatic latent image according to any one of the above (1) to (6). (8) The polyester resin has an average particle size (D ₅₀ )
(1) wherein the thickness is 200 to 600 μm.
The toner for developing an electrostatic latent image according to any one of (7) to (7). (9) The toner for developing an electrostatic latent image according to any one of (1) to (8), wherein fluidizing agent particles are added to and mixed with the toner surface. (10) The toner for developing an electrostatic latent image according to any one of (1) to (9), wherein the fluidizing agent particles are silica having a specific surface area of 90 to 240 m ² / g. (11) The fluidizer particles are contained in an amount of 0.1 to the total weight of the toner.
Above (1) to (1)
0) The electrostatic latent image developing toner according to any one of the above items. (12) An image forming apparatus using the toner for developing an electrostatic latent image according to any one of (1) to (11).

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The toner for developing an electrostatic latent image of the present invention contains a polyester resin as a main component. The polyester resin used in the present invention is a polymer in which a polybasic acid and a polyhydric alcohol are linked by a polycondensed ester bond, and may be either saturated or unsaturated. The type of the polyester resin is not particularly limited, and examples thereof include various types such as an unsaturated polyester resin, an alkyd resin, polyethylene terephthalate, polybutylene terephthalate, and polyarylate, and an unsaturated polyester resin is particularly preferable.

The polybasic acid constituting the polyester resin is not particularly limited. Examples of the carboxylic acids include aliphatic dicarboxylic acids (eg, maleic acid, fumaric acid, succinic acid, adipic acid, sebacine). Acid, malonic acid, azelaic acid, mesaconic acid, citraconic acid, etc.), aromatic dicarboxylic acid (eg, phthalic acid, isophthalic acid, terephthalic acid, etc.), alkyl or alkenyl succinic acid (eg, dodecenyl succinic acid, pentadodecenyl) Succinic acid, etc.), and anhydrides and lower alkyl esters of these dicarboxylic acids are preferably used. Maleic acid, fumaric acid, isophthalic acid, terephthalic acid, trimellitic acid, dodecenyl succinic acid and the like are more preferred. The polyhydric alcohol is not particularly limited, but for example, diols such as alkylene glycol (eg, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,5-pentanediol, 1,6-pentanediol, etc., alkylene ether glycols (eg, diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene) Glycol, etc.), alicyclic diols (eg, hydrogenated bisphenol A, etc.), and bisphenols (eg, bisphenol A, bisphenol F, bisphenol S, etc.). These polybasic acids and polyhydric alcohols may be used alone or in combination of two or more.

The polyester resin used in the present invention comprises 1
An acid value of 5-35 mgKOH / g (JIS K0070-
1966). Here, the acid value is an index of the number of carboxyl residues at the terminal of the polyester resin. The acid value of the polyester resin is 15mgKOH
If the amount is less than / g, the superiority of the original negative charge property of the polyester cannot be sufficiently exhibited, and the fixing property and the offset resistance may be inferior. If the amount is more than 35 mgKOH / g, the polyester may have poor water resistance under a high temperature and high humidity environment. This is because a problem may occur during actual copying such as inferiority, background fog and toner scattering.

The acid value of the polyester resin is determined by, for example, increasing the proportion of a polybasic acid (for example, trimellitic anhydride, terephthalic acid, fumaric acid, alkenyl succinic acid, etc.) used rather than the dibasic acid in the polyester resin. Can be bigger. For example, about 1-5% of fumaric acid,
The acid value can be increased by adding 1-5% of trimellitic anhydride.

Further, in the present invention, a polyester resin using a polybasic acid having an aromatic ring and a polyhydric alcohol comprises:
It is preferable because the blocking resistance is good. Particularly, a polyester resin obtained by reacting a carboxylic acid containing an aromatic dicarboxylic acid or a derivative thereof with a diol is preferable.

The polyester resin of the present invention has a softening point (T
m) is preferably 110 to 140 ° C. (flow tester constant temperature heating method 6 ° C./min, load 20 kg,
Die 1mm × 0.5mmφ CFT500 manufactured by Shimadzu Corporation). By setting the Tm value in this range, the fixing property and / or the offset resistance can be improved.

The polyester resin of the present invention has a glass transition temperature (Tg) of 45 to 70 ° C. (ASTM D 3
418-82). By setting the Tg value within this range, the blocking resistance and / or the offset resistance can be improved.

The average particle size (D) of the polyester resin of the present invention
₅₀ ) is preferably 200 to 600 μm. D ₅₀
By setting the value within this range, the dispersibility of the oxidized polyethylene wax is appropriately improved, and furthermore, the fixing property of the oxidized polyethylene wax and the occurrence of crest can be suppressed. That is, regarding the dispersion of the toner, in the pre-mixing step of the toner manufacturing process, the binder resin is used as a core and various raw materials are adhered therearound (by electrostatic adhesion, van der Waals force, slimy adhesion force, etc.). )) And has important significance in controlling dispersibility. Therefore, the particle size of the binder resin is a great influence on toner dispersibility is less than D ₅₀ value is 200 [mu] m, it can not be exhibited the original wax performance oxidized polyethylene wax is too fine particle dispersion, the rubs fixability Problems may occur. Further, in the 600μm than D ₅₀ value, large particles of polyethylene wax occurs and free polyethylene, or toner polyethylene excess occurs, the generation of minute charged toner, and by extension may cause the occurrence of crest.

The polyester resin of the present invention is usually obtained by performing a dehydration condensation reaction or an ester conversion reaction using the above-mentioned raw material components in an organic solvent in the presence of a catalyst.
The reaction temperature at this time is, for example, 150 to 300 ° C. When performing the above reaction, for the purpose of promoting the reaction, an esterification catalyst or an ester conversion catalyst, for example, magnesium acetate,
Zinc acetate, lead acetate, antimony trioxide and the like can be used. More specifically, for example, a diol having a main skeleton, a dicarboxylic acid, and an alcohol crosslinking agent and an acid crosslinking agent are subjected to a dehydration esterification reaction in the presence of a catalyst to synthesize a finely crosslinked polyester. Next, an OH group terminal blocking agent for dicarboxylic acids (eg, dimethyl terephthalate) is added, and the hydroxyl value is adjusted by demethanol transesterification. Further, an acid crosslinking agent is added to cause an acid value imparting reaction,
The polyester resin can be obtained by thickening (crosslinking). In the present invention, for example, by increasing the amount of fumaric acid and trimellitic anhydride and using a polyester resin having a relatively large acid value, the offset resistance can be improved and the negative chargeability can be improved. .

In the toner for developing an electrostatic latent image of the present invention, the polyester resin is used in an amount of 80 to 80% based on the total weight of the toner.
About 95% by weight is preferable, and about 85 to 90% by weight is more preferable.

Oxidized polypropylene is certainly compatible with general polyester resins, can disperse fine particles, and is effective in offset phenomenon and photoconductor fusion. However, when the compatibility is too good and there is a black solid image at the image tip, a remarkable paper JAM occurs. However, in the present invention, the above problem does not occur because non-oxidized polypropylene is used.

In the present invention, the apparent apparent specific gravity AD of the oxidized polypropylene is loose (based on JIS K5101).
Is preferably 0.6 g / cc or less. In other words, in the present invention, in order to appropriately disperse the fine particles of the polypropylene into the toner, the non-oxidized polypropylene is pulverized and melt-kneaded into the toner, thereby improving the lubricity of the polypropylene, that is, the so-called slipperiness of the black solid image surface. Thus, the releasability between the fixing roller and the paper can be increased without causing an offset phenomenon or fusion of the photosensitive member.
The apparent apparent specific gravity AD of the non-oxidized polypropylene is 0.
If it exceeds 6 g / cc, it is difficult to disperse the fine particles in the toner, and it is possible to appropriately disperse the fine particles in the polyester resin by pulverizing the fine particles to 0.6 g / cc or less in advance. Also, when grinding non-oxidized polypropylene,
Any machine having a pulverizing function, such as a commercially available air jet mill, Henschel mixer, super mixer, or Q-type mixer, can be used without any particular limitation. The non-oxidized polypropylene can be contained in an amount of about 0.5 to 5.0% by weight based on the total weight of the toner.

The oxidized polyethylene used in the present invention preferably has an acid value of 15 mgKOH / g or more. When the acid value of the oxidized polyethylene is less than 15 mgKOH / g, the fixing property of the rust is inferior, the transfer of the black solid image to the paper or the back stain occurs, and the crest is formed at the tip of the black solid or the large area character portion. appear.

The amount of the oxidized polyethylene relative to the total amount of the toner can be 0.5 to 5.0% by weight.
More preferably, it is 0 to 3.0% by weight. The blending amount is 0.
When the amount is less than 5% by weight, the fixing property of the image is poor, and the transfer of the solid black image to the paper or the stain on the back may occur. On the other hand, if the compounding amount is more than 5.0% by weight, the amount is too large, so that polyethylene wax of large particles is generated, and crests may be generated at a black solid or at the tip of a large area character portion. In the toner for developing an electrostatic latent image of the present invention, it is preferable to carry fluidizing agent particles on the toner surface. Examples of the fluidizing agent particles include silica and the like.

The fluidizing agent particles are based on the total weight of the toner.
It is preferable to mix about 0.1 to 3.0% by weight,
More preferably, it is 0.3 to 1.0% by weight. The specific surface area of the fluidizing agent particles is 90 to 240 m ² / g (BE
T method) is preferred. The imparting of fluidity to the toner is due to the spacer effect, and it is preferable that air is interposed between the toner particles. Therefore, by setting the above specific surface area, a further spacer effect can be obtained. The above range is a range that does not impair the fluidity at the time of copying, and if it is less than this range, there is little air intervention and a sufficient spacer effect may not be obtained.
Aggregation between silicas is liable to occur, and free silica is generated, which may cause a white spot on a copied image and adversely affect it.

The charge control agent that can be blended with the toner of the present invention is not particularly limited, but a preferred example is a chromium complex compound represented by the following formula.

[0024]

Embedded image(Wherein X is chlorine atom, bromine atom, group SO_TwoNH_Two, Group S
O_TwoCH_Three, Group SO_TwoC_TwoH _FiveAnd A⁺Has 8 to 16 carbon atoms
Even if interrupted by a straight-chain or one heteroatom
Good branched alkyl ammonium. )

Here, the "hetero atom" includes, for example, a nitrogen atom, an oxygen atom, a sulfur atom and the like, and an oxygen atom is particularly preferable. Examples of the “linear alkyl ammonium having 8 to 16 carbon atoms” include, for example, NH ₃ C ₁₂ H
₂₅ ⁺ , NH ₃ C ₁₄ H ₂₉ ^{+ and the} like. Furthermore, the "one alkyl ammonium may also branches be interrupted by a heteroatom 8-16 carbon atoms", for _{example, NH 3 C 3 H 6 OC} (C 2 H 5) HC 4 H 9 +, NH ₃ C ₃ O
_{CH 2 C (C 2 H 5} ) HC 4 H 9 + , and the like.

The charge control agent is based on the total weight of the toner.
It is preferable to add about 0.5 to 5% by weight,
It is more preferable that the amount is about weight%.

The toner for developing an electrostatic latent image of the present invention may further contain a positive charge control agent. Preferred examples of the positive charge control agent include a nigrosine dye, a pyridinium salt, an ammonium salt, and a lake compound thereof. The positive charge control agent is used in an amount of about 0.05 to 0.5% by weight, particularly about 0.1% by weight, based on the total weight of the toner.
It is preferable to add about 1 to 0.3% by weight.

The toner for developing an electrostatic latent image of the present invention contains additives such as a fixing release agent, a colorant, a dispersant, and a magnetic powder which can be generally used for the toner, in addition to the above components. It may be. Further, a resin other than the polyester resin may be used in combination.

Examples of the fixing release agent include natural waxes such as montanic acid ester wax and carnauba wax, polyolefin waxes such as high pressure polyethylene and polypropylene, silicone waxes and fluorine waxes.

Examples of the colorant include carbon black, magnetic powder, nitro, stilbene azo, diphenylmethane, triphenylmethane, methine, thiazole, anthraquinone, imidamine, azine, oxaazine, and thiazine. Organic dyes and pigments such as organic dyes, sulfur dyes, indigoids, and phthalocyanines.

Examples of the dispersant include metal soap, polyethylene glycol and the like. As magnetic powder,
For example, iron, cobalt, nickel, chromium, metals such as manganese or alloys thereof, chromium dioxide, iron sesquioxide,
Metal oxides such as ferrite are exemplified.

Examples of the resin include a styrene resin, a styrene-acryl copolymer resin, a styrene-acrylonitrile copolymer resin, an acrylic resin, a styrene-maleic anhydride copolymer resin, and a styrene-acryl-maleic anhydride copolymer. Examples include a coalescing resin, a polyvinyl chloride resin, a polyvinyl acetate resin, a polyolefin resin, a polyurethane resin, a urethane-modified polyester resin, and an epoxy resin.

The toner for developing an electrostatic latent image of the present invention can be manufactured by a known method. For example, Henschel mixer,
The above components are mixed by a mixable device such as an airflow mixer such as a super mixer, a mechano mill, or a Q-type mixer,
With a device such as a twin-screw kneader or a single-screw kneader, 70 to 180
Melt and knead at a temperature of about ° C. The obtained kneaded product can be manufactured by cooling and solidifying, and then pulverizing the solidified product with an air-type pulverizer such as a jet mill. The pulverization is preferably performed so that the toner particles have a particle size of about 5 to 25 μm, and more preferably about 7 to 10 μm.

[0034]

Next, the present invention will be described in more detail with reference to examples and the like, but the present invention is not limited by these examples. Example 1 (Components) (Blending amount) 100 parts by weight of polyester resin 1 (acid value 28, glass transition point Tg 57 ° C, softening point Tm 119 ° C, manufactured by Kao) Non-oxidized polypropylene 2 parts by weight (viscol 550P loose apparent specific gravity AD0. 45 g / cc Sanyo Chemical Industries) Oxidized polyethylene 2 parts by weight (Hoe-WaxPED153 Clariant Japan) 1.5 parts by weight negative charge control agent (Aizen Spiron Black TRH Hodogaya Chemical Industry) carbon black 5 parts by weight (MA- 77 Mitsubishi Chemical Corporation) The above components were dry-mixed, melted and kneaded with a twin-screw extruder, and then cooled and pulverized to obtain an 8 μm toner. To the toner was added 0.5 parts by weight of a fluidizing agent particle silica (Aerosil R976S manufactured by Nippon Aerosil) to obtain a toner.

Example 2 (Components) (Blending amount) 100 parts by weight of polyester resin 2 (acid value 15, glass transition point Tg 68 ° C., softening point Tm 140 ° C., manufactured by Kao) Non-oxidized polypropylene 2 parts by weight (high wax NP505 slack) Apparent specific gravity AD 0.58 g / cc Mitsui Chemicals) Oxidized polyethylene 2 parts by weight (Hoe-Wax PED 136 Clariant Japan) Superplasticizer particles 0.5 parts by weight (Aerosil R974 Nippon Aerosil) In the same manner as in Example 1, a toner was obtained.

Example 3 (Components) (Blending Amount) 100 parts by weight of polyester resin 3 (acid value 33, glass transition point Tg 47 ° C., softening point Tm 112 ° C., manufactured by Kao) Non-oxidized polypropylene 2 parts by weight (Himer TP32 loose appearance) Specific gravity AD 0.21 g / cc manufactured by Sanyo Kasei Kogyo) Oxidized polyethylene 2 parts by weight (Hoe-Wax PED Clariant Japan) Superplasticizer particles 0.3 part by weight (Aerosil R812S Nippon Aerosil) Similarly, a toner was obtained.

Example 4 (Components) (Blending amount) Non-oxidized polypropylene 0.5 parts by weight (Viscol 550P loose apparent specific gravity AD 0.45 g / cc manufactured by Sanyo Chemical Industries) Oxidized polyethylene 0.5 parts by weight (High wax) 4052E (manufactured by Mitsui Chemicals) A toner was obtained in the same manner as in Example 1, except that 1.0 part by weight of fluidizing agent particles (manufactured by HDK H2000 PACKER) was used.

Example 5 (Components) (Blending Amount) Non-oxidized polypropylene 4 parts by weight (Viscol 550P loose apparent specific gravity AD 0.45 g / cc manufactured by Sanyo Chemical Industries) Oxidized polyethylene 4 parts by weight (High Wax 4052E manufactured by Mitsui Chemicals) A toner was obtained in the same manner as in Example 1, except that 0.7 parts by weight of fluidizing agent particles (manufactured by HDK H3004 WORKER) was used.

Comparative Example 1 (Components) (Blending amount) Polyester resin 1 100 parts by weight Oxidized polyethylene 2 parts by weight (Sunwax LEL-400P manufactured by Sanyo Chemical Industries) Superplasticizer particles 4.0 parts by weight (RX50 Nippon Aerosil) A toner was obtained in the same manner as in Example 1 except that

Comparative Example 2 (Component) (Blending Amount) 100 parts by weight of polyester resin 2 2 parts by weight of non-oxidized polypropylene (HIWAX NP505 loose apparent specific gravity AD 0.58 g / cc manufactured by Mitsui Chemicals) Fluidizing agent particles 0.1 A toner was obtained in the same manner as in Example 1 except that the weight part (300 manufactured by Nippon Aerosil Co., Ltd.) was used.

Comparative Example 3 (Ingredient) (Blending amount) Polyester resin 3 100 parts by weight Non-oxidized polypropylene 2 parts by weight (Himer TP32 loose apparent specific gravity AD 0.21 g / cc manufactured by Sanyo Chemical Industries) Oxidized polyethylene 2 parts by weight ( High Wax 4051E (manufactured by Mitsui Chemicals) A toner was obtained in the same manner as in Example 1 except that 0.3 parts by weight of fluidizing agent particles (R812 manufactured by Nippon Aerosil) was used.

Comparative Example 4 (Ingredients) (Blending amount) Polyester resin 1 100 parts by weight Non-oxidized polypropylene 0.3 parts by weight (Viscol 550P loose apparent specific gravity AD 0.68 g / cc manufactured by Sanyo Chemical Industries) Oxidized polyethylene 0. A toner was obtained in the same manner as in Example 1 except that 3 parts by weight (Sunwax LEL-400P manufactured by Sanyo Chemical Industries) was used and 1.0 part by weight of fluidizing agent particles (MOX80 manufactured by Nippon Aerosil) was used.

Comparative Example 5 (Component) (Blending amount) Polyester resin 1 100 parts by weight Non-oxidized polypropylene 6 parts by weight (Viscol 550P loose apparent specific gravity AD 0.89 g / cc manufactured by Sanyo Chemical Industries) Oxidized polyethylene 6 parts by weight ( High Wax 4051E (manufactured by Mitsui Chemicals) A toner was obtained in the same manner as in Example 1, except that 1.0 part by weight of fluidizer particles (R976S manufactured by Nippon Aerosil) was used.

Test Examples The following items were tested for the toners obtained in the above examples. 1. Evaluation of fixing offset resistance: A real copying test was performed using a digital copier AR-405 whose fixing section was modified so as to be variable in temperature and evaluated. The paper passing was 8.5 inch x 11 inch cat paper. <Evaluation criteria> Low-temperature side offset occurrence temperature: 140 ° C or less was evaluated as ◎. High-temperature-side offset occurrence temperature: 220 ° C. or higher was evaluated as ◎.

2. Actual photo test result: Crest (black solid, toner leading edge phenomenon of large area characters): A real photo test was performed using a digital copying machine AR-405 manufactured by Sharp to evaluate. The paper passing was 8.5 inch x 11 inch cat paper. <Evaluation criteria> Crest evaluation No occurrence: ◎ Slight occurrence: ○ Occurrence: △

Black solid toner fixing rate: (a) Using a digital copying machine AR-405 manufactured by Sharp, a 30 mm square black solid image is sampled, and the image density is measured (image density A). The paper passing was 8.5 inch x 11 inch cat paper. (B) As shown in FIG. 1, the above-mentioned black solid image of 30 mm square was 5
After rubbing back and forth, the image density is measured (image density B). (C) The black solid waste fixing rate was calculated according to the following equation. Black solid waste fixing rate (%) = Image density B ÷ Image density A ×
100 <Evaluation Criteria> Rust fixing rate (%) Evaluation 80% or more: 60% or more and less than 80%: ○ Less than 60%: △

Solid black paper JAM property: Using a digital copying machine AR-405 made by Sharp, 50 continuous solid black images were continuously copied, and the paper JAM occurrence rate was calculated out of 50 sheets. The paper passing was 8.5 inch x 11 inch cat paper. <Evaluation criteria> Paper JAM occurrence rate (%) Evaluation 0% (no occurrence): ◎ Less than 10%: ○ 10% or more: △

Evaluation of image density and background fog: Using a digital copying machine AR-405 manufactured by Sharp, at room temperature and normal humidity (2
(0 ° C .; 65%) An evaluation was performed by performing a real-life test in an environment.
The paper passing was 8.5 inch x 11 inch cat paper. A) Image density Through a real-image test (using 6% original) of 80,000 sheets, 1.35 or more was evaluated as ◎, and less than 1.35 was evaluated as x. For measurement, a PROCESS MEASUREMENTS RD914 manufactured by Macbeth was used. B) Background fog 80,000 sheets through a real-life test (using 6% original), ◎ for less than 0.50, ○ for 0.50 to 0.70,
A value exceeding 0.70 was defined as Δ. For the measurement, COLOR METER ZE2000 type manufactured by NIPPON DENSHOKU was used.

3. Comprehensive evaluation A comprehensive evaluation was performed according to the following criteria.

Table 1 shows the characteristics of the toner used in the above test.
Table 2 shows the test results.

[Table 1]

[0051]

[Table 2]

[0052]

EFFECT OF THE INVENTION The toner of the present invention does not impair filming, fixing property and offset property on the photoreceptor, has good solid black image fixability after fixing, and forms a good copy image without crest. You can do it. In the present invention, the polyester resin has a high glass transition point Tg,
It itself has offset resistance, blocking resistance, and photoreceptor filming resistance, and has an acid value of 15 to 35 (mg).
By using a material having high negative charge stability (KOH / g), better characteristics can be realized. Further, by containing a non-oxidized polypropylene having a loose apparent specific gravity AD of 0.6 (g / cc) or less, it has appropriate dispersibility, and can avoid fixing property, offset resistance, and paper JAM. Furthermore, by containing an oxidized polyethylene having an acid value of 15 (mgKOH / g) or more, it is possible to obtain a good toner which has extremely good compatibility with the polyethylene resin, and has no rusting property and no crest. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the outline of a black solid waste fixing rate test.

[Explanation of symbols]

1 ... 400G weight (φ50mm) with catosa paper stuck on the bottom surface 2 ... ... 30mm square black solid 3 ... 8.5 inch x 11 inch catosa paper 4・ ・ ・ ・ ・ ・ 5 reciprocating directions

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Katsuaki Sumida 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka F-term (reference) 2H005 AA01 AA06 AA08 CA08 CA13 CB13 EA03 EA05 EA07 EA10

Claims (12)

[Claims] 1. An electrostatic latent image developing toner mainly comprising a polyester resin formed by reacting a dicarboxylic acid of a polybasic acid with a diol of a polyhydric alcohol. An electrostatic latent image developing toner comprising: an oxidized polyethylene of 15 mgKOH / g or more. 2. The electrostatic latent image developing toner according to claim 1, wherein the non-oxidized polypropylene is contained in an amount of 0.5 to 5.0% by weight based on the total weight of the toner. 3. The electrostatic latent image developing toner according to claim 1, wherein the non-oxidized polypropylene has a loose apparent specific gravity AD of 0.6 g / cc or less. 4. The electrostatic latent image developing device according to claim 1, wherein the oxidized polyethylene is contained in an amount of 0.5 to 5% by weight based on the total weight of the toner. toner. 5. The polyester resin having an acid value of 15 to 15.
5. The toner for developing an electrostatic latent image according to claim 1, wherein the toner is 35 mgKOH / g. 6. The softening point (Tm) of the polyester resin.
The toner for developing an electrostatic latent image according to claim 1, wherein the temperature of the toner is 110 to 140 ° C. (flow tester constant temperature heating method). 7. The electrostatic latent image developing toner according to claim 1, wherein the polyester resin has a glass transition temperature (Tg) of 45 to 70 ° C. 8. The electrostatic latent image developing toner according to claim 1, wherein the polyester resin has an average particle diameter (D ₅₀ ) of 200 to 600 μm. 9. The electrostatic latent image developing toner according to claim 1, wherein fluidizing agent particles are added to and mixed with the toner surface. 10. The superplasticizer particles have a particle size of 90 to 240 m ² /
The toner for developing an electrostatic latent image according to any one of claims 1 to 9, wherein the toner is silica having a specific surface area of g. 11. The method according to claim 11, wherein the fluidizing agent particles are based on the total weight of the toner.
2. The composition of claim 1, wherein 0.1 to 3.0% by weight is added and mixed.
0. The toner for developing an electrostatic latent image according to any one of items 0. 12. An image forming apparatus using the electrostatic latent image developing toner according to claim 1. Description: