JPH029341B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to toners used in electrophotographic development. More specifically, the present invention relates to a toner for dry electrostatic image development that has excellent charge control during development and transfer, excellent fixing properties and offset resistance when fixing using a heated roll fixing method, and has good negative chargeability. . Electrophotography uses inorganic photoconductive materials such as selenium, zinc oxide, cadmium sulfide, or anthracene,
An electrostatic latent image is formed on a photoconductive layer or a photosensitive plate containing an organic photoconductive material such as polyvinylcarbazole in a binder resin as necessary, and this is developed with a developer consisting of toner. ,paper,
It is transferred onto a sheet, etc., and then fixed using a solvent, heat, pressure, etc. This developer is composed of a mixture of a toner and a carrier, and the toner further contains a coloring agent such as carbon black, a charge control agent such as an azo dye, etc., dispersed in a natural or synthetic fixing resin. In electrophotography, the triboelectricity of toner and carrier during development is important. That is, when the amount of charge on the toner is small, the electrostatic attraction between the toner and the carrier is weak, and therefore the toner is released from the carrier by a slight impact, resulting in staining of the background. On the other hand, if the amount of charge on the toner is too large, it becomes difficult for the toner to be released from the carrier during development, which not only requires a strong electric field in the device but also worsens the edge effect. Therefore,
In producing toner, it is necessary to control the amount of charge within a suitable range. In order to control the amount of charge on the toner, a method is generally adopted in which a small amount of a charge control agent mainly consisting of a dye is added to a mixture of a fixing resin and a colorant. It is difficult to uniformly disperse the toner, and the toner itself has the disadvantage of causing unevenness in the amount of charge. Furthermore, in electrophotography, the toner image is fixed after development and transfer. Conventionally, the so-called oven fixing method, in which the transferred toner image is melted and fixed in an oven, has been the mainstream. In recent years, from the viewpoints of downsizing, high-speed copying, and energy saving of copying machines, there has been a shift to a so-called heated roll fixing system in which fixing is performed using a heated roll. In the conventional oven fixing method, a so-called oligomer resin having a molecular weight of 10,000 or less is used as the toner fixing resin because it needs to melt quickly in the oven. However, in the heated roll fixing method, when such oligomers are used as the fixing resin, a portion of the toner adheres to the surface of the fixing roll during fixing and stains other adjacent paper or sheets, resulting in so-called offset. It is extremely impractical. In order to prevent this offset, there is a method of applying a release liquid such as silicone oil to the fixing roll, but it is mechanically difficult to apply it evenly.
Furthermore, there are many problems such as generation of odor due to heating of the mold release liquid. In order to prevent offset from the aspect of fixing resin, it is effective to increase the molecular weight of the resin, and in the case of polystyrene, which is commonly used as a resin, the average molecular weight is 50,000 or more, preferably 100,000 or more, which requires heating. No offset to the roll at all. However, when such a high-molecular-weight resin is used as a fixing resin, there is a drawback that the toner's fixability to paper or sheets is extremely poor, and once the fixed image is It has the disadvantage that it peels off easily. Therefore, a first object of the present invention is to provide a toner for developing electrostatic images that has excellent charge control properties and excellent developability and transferability. A second object of the present invention is to provide a toner for developing electrostatic images with excellent fixing properties and offset properties, which solves the problems that occur in heated roll fixing systems. In particular, in order to achieve the second objective, there are methods of adding oligomers with a molecular weight of about 1000 or less to high molecular weight polystyrene, methods of adding a release agent such as paraffin to relatively low molecular weight polymers, and methods of adding a mold release agent such as paraffin to a relatively low molecular weight polymer. Acrylic polymer has a molecular weight of approximately 10,000
The following methods of adding low molecular weight polyolefins, etc., methods of partially crosslinking with bifunctional monomers, etc. have been proposed. However, the reality is that the first objective mentioned above has not been achieved at the same time. The present inventors have conducted extensive research on toner for developing electrostatic images (hereinafter referred to as the toner of the present invention) that is particularly suitable for heated roll fixing systems and satisfies the above conditions. In the presence of an excellent unsaturated polyester resin, an active vinyl monomer mixture containing an aromatic vinyl monomer and an α,β-disubstituted aliphatic unsaturated dibasic acid diester monomer as essential components is combined. The inventors have discovered that the resin composition obtained by polymerization exhibits excellent properties, and have completed the present invention. That is, the resin composition of the present invention contains 0.2 to 10% by weight of aliphatic unsaturated dibasic acid. The glass transition point (hereinafter referred to as Tg) by DTA is 50~90℃, and the softening point (hereinafter referred to as softening point) is 80~90℃ by the return ball method.
120℃, acid value 5-60mgKOH/g, average molecular weight (hereinafter referred to as average molecular weight) by end group method 500
98 to 50 parts by weight of an active vinyl monomer mixture are copolymerized in the presence of 2 to 50 parts by weight of an unsaturated polyester of ~10,000, and in this monomer mixture at least 50% by weight of aromatics. vinyl monomer and 2~
It is characterized by containing 50% by weight of α,β-disubstituted aliphatic unsaturated dibasic acid diester monomer as an essential component. The present invention will be explained in more detail below. The unsaturated polyester which is the first component of the resin composition of the present invention contains an aliphatic saturated dibasic acid and/or an aromatic dibasic acid, an aliphatic dihydric alcohol and/or an alicyclic dihydric alcohol and/or an aromatic It is obtained by polycondensation reaction with dihydric alcohol, but it contains 0.2% of aliphatic unsaturated dibasic acid as an essential component.
It is necessary to contain ~10% by weight. Examples of the aliphatic unsaturated dibasic acid used in the present invention include maleic acid, fumaric acid, itaconic acid, citraconic acid, and acid anhydrides thereof, and maleic anhydride is industrially most preferred. Other dibasic acids include succinic acid, glutaric acid,
Aliphatic saturated dibasic acids such as adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, phthalic acid and anhydride, isophthalic acid, terephthalic acid , tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 3,3',4,
Examples include aromatic dibasic acids such as 4'-benzophenonetetracarboxylic anhydride. Examples of dihydric alcohols include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-butanediol, 1,4
-butanediol, 1,5-pentanediol,
Aliphatic dihydric alcohols such as 1,6-hexanediol, neopentyl glycol, 3,3,5-trimethyl-2,4-pentanediol, 1,4
- Alicyclic dihydric alcohols such as cyclohexanedimethanol, hydrogenated bisphenol A, bisphenol A ethylene oxide adduct (hereinafter referred to as bisphenol A EO adduct), bisphenol A
Examples include aromatic dihydric alcohols such as propylene oxide adduct (hereinafter referred to as bisphenol A PO adduct). In addition to these ingredients, trimellitic anhydride,
Trifunctional compounds such as glycerin, trimethylolethane, trimethylolpropane, benzoic acid,
Monofunctional compounds such as p-tert-butylbenzoic acid, cyclohexanol, and 2-ethylhexanol can also be used as appropriate for molecular weight adjustment. The aliphatic unsaturated dibasic acid in the above components is an important component in the sense that it serves as an active site during copolymerization, and its content is suitably 0.2 to 10% by weight. If the content of aliphatic unsaturated dibasic acid is less than 0.2% by weight, copolymerization is difficult to occur, and if it is more than 10% by weight, gelation tends to occur during polymerization, making it impractical. The preferred content varies depending on the molecular weight of the unsaturated polyester, but the optimum content is 0.5 to 7% by weight. The Tg and softening point of unsaturated polyester are each 50~
The temperature is preferably 90° C. and 80 to 120° C. If the above-mentioned value is lower or higher than that, it will adversely affect the fixing properties and crushability of the toner, although this will vary depending on the amount of unsaturated polyester used. The acid value of unsaturated polyester is 5 to 60 mgKOH/
g is suitable, but if the acid value is less than 5 mgKOH/g or more than 60 mgKOH/g, the amount of charge will be insufficient or excessive, depending on the amount of unsaturated polyester used, resulting in poor developability and transferability. Adversely affect. The preferred acid value is optimally 10 to 50 mgKOH/g. The molecular weight of the unsaturated polyester is preferably 500 to 10,000, but if the molecular weight exceeds 10,000 and becomes too large, gelation tends to occur during polymerization, making it difficult to obtain a suitable resin composition. The preferred molecular weight varies depending on the amount of unsaturated polyester used, but is 1500
~5000 is optimal. The above unsaturated polyester is manufactured by a conventional method.
The reaction is carried out at a temperature of 150 to 250°C while introducing an inert gas with an OH excess of 0 to 50%, and the desired unsaturated polyester can be obtained by tracking the reaction by measuring the acid value, hydroxyl value, and softening point. Can be done. Further, the acid anhydride may be added for the purpose of adjusting the acid value. A resin composition is obtained by copolymerizing an active vinyl monomer mixture in the presence of the unsaturated polyester thus obtained. The monomer mixture includes, as essential components, aromatic vinyl monomers such as styrene, α-methylstyrene, and o-chlorostyrene, dimethyl maleate, diethyl maleate, dibutyl maleate, and di-2 maleate. α,β-disubstituted aliphatic unsaturated dibasic acid diester monomers such as -ethylhexyl, dimethyl fumarate, diethyl fumarate, dibutyl fumarate, and di-2-ethylhexyl fumarate; As vinyl monomers, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-methacrylate
Examples include ethylhexyl, acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid. The above monomers include, as essential components, at least 50% by weight of an aromatic vinyl monomer and 2 to 50% by weight of an α,β-disubstituted aliphatic unsaturated dibasic acid diester monomer.
Can be used in a range of weight percentages. According to a preferred embodiment of the present invention, the above monomer contains styrene as an aromatic vinyl monomer.
-85% by weight, 40-15% by weight of dibutyl fumarate as the α,β-disubstituted aliphatic unsaturated dibasic acid diester monomer, and 0-25% by weight of 2-ethylhexyl acrylate as other monomers. An optimal fixing resin can be obtained in this case. In copolymerizing the above monomer in the presence of the unsaturated polyester, the monomer is added to 2 to 50 parts by weight, preferably 5 to 40 parts by weight of the unsaturated polyester.
It is optimal to use 98-50 parts by weight, preferably 95-60 parts by weight. Polymerization reaction methods for copolymerizing monomers in the presence of unsaturated polyester include solution polymerization, suspension polymerization, and emulsion polymerization, but suspension polymerization is optimal from an industrial standpoint. The suspension polymerization reaction can be carried out using an unsaturated polyester and a monomer in water in the presence of a polymerization initiator and a dispersant at a temperature of 60 to 90°C according to a conventional method. The molecular weight of the resin composition that is the fixing resin used to obtain the toner of the present invention is 50,000 or less, preferably
5000-30000. When producing the resin composition by suspension polymerization, examples of the polymerization initiator include 2,2'-azobisisobutyronitrile, benzoyl peroxide, benzyl peroxide, t-butylperoxy 2-ethylhexanoate, etc. Can be used alone or in combination. Further, as the dispersant, polyvinyl alcohol, polyvinylpyrrolidone, methyl cellulose, hydroxyethyl cellulose, polyacrylic acid, polymethacrylic acid, magnesium carbonate, lime triphosphate, calcium phosphate, etc., which are used in ordinary suspension polymerization, can be used. The obtained resin composition according to the present invention has a Tg of about 50
-80°C, and a softening point of about 110-170°C is particularly suitable as a fixing resin. That is, when the Tg is about 50°C or less, the fixing performance is excellent, but the toner tends to form lumps due to the cold flow phenomenon, and when the Tg is about 80°C or more, the fixing is insufficient, especially during high-speed copying. . On the other hand, when the softening point is below about 110°C, contamination of the photoconductive layer or photosensitive plate is likely to occur due to toner filming phenomenon, and when the softening point is above about 170°C,
It is difficult to crush when making toner, and furthermore, a large amount of heat is required during fixing, which is not practical. In addition, the resin composition according to the present invention allows the resin fine powder (average particle size of about 10 μm to 20 μm) itself to be mixed with iron powder (average particle size of about 500 μm) by the blow-off method by changing the amount of unsaturated polyester used. The amount of triboelectric charge can be adjusted arbitrarily within the range of approximately -10μc/g to -40μc/g, making it possible to adjust the design of copying machines without using charge control agents such as dyes used in conventional toners. This makes it possible to obtain appropriate charging characteristics. The toner of the present invention can be obtained by using the resin composition according to the present invention as a fixing resin, melting and kneading a colorant by a conventional method, cooling it, and then pulverizing it with a hammer mill, jet mill, etc. When the above-mentioned resin composition is used as a fixing resin in the toner of the present invention, it has excellent developability and transferability, and also has low-temperature fixability when fixing by a heated roll fixing method and so-called offset resistance that is difficult to offset. The traditional problem of balancing work and work can be solved all at once. Although it is not clear why the toner of the present invention is effective in both low-temperature fixing properties and both offset properties, the molecular weight of the resin composition of the present invention is determined by gel permeation chromatography (hereinafter referred to as GPC). When the distribution was measured, the molecular weight distribution of the monomer alone without using the unsaturated polyester was about 2 to 4 in terms of Mw/n, whereas the molecular weight distribution was about 2 to 4 in w/n.
Mn is approximately 5 to 20, and by copolymerizing an active vinyl monomer mixture in the presence of unsaturated polyester, a low molecular weight portion (molecular weight approximately 1000) that contributes to low-temperature fixing properties is used to improve offset resistance. This is thought to be due to the fact that both contributing high molecular weight parts (molecular weight approximately 5 million) are included in the resin composition of the present invention. Further, the α,β-disubstituted aliphatic unsaturated dibasic acid diester monomer in the monomer is an essential component of the resin composition of the present invention, and the monomer excluding this monomer is When the monomer is copolymerized in the presence of the unsaturated polyester, it is difficult to control the molecular weight, Tg, and softening point of the resin composition compared to the case of the resin composition of the present invention using the present monomer. Moreover, the pulverizability of the obtained resin composition when it is made into a toner is very poor. The reason why the present monomer is so effective is thought to be due to its polymerizability and property of softening the resin without reducing its crushability. Colorants that can be used in the toner of the present invention include black pigments such as carbon black, acetylene black, lamp black, and aniline black, yellow pigments such as yellow lead, zinc yellow, yellow iron oxide, nickel titanium yellow, benzidine yellow GR, and molybdenum. Orange pigments such as Orange, Permanent Orange GTR, Benzidine Orange G, Indanthrene Brilliant Orange GK, red pigments such as Red Garla, Permanent Red 4R, Watching Red, calcium salts, Lake Red, Alizarin Lake, Brilliant Carmine 3B, Manganese Violet pigments such as purple, fast violet B, methyl violet lake, blue pigments such as navy blue, cobalt blue, Victoria blue lake, phthalocyanine blue, fast sky blue, indanthrene blue BC, pigment green B, malachite green lake , green pigments such as Fuanal Yellow Green G, white pigments such as zinc white, titanium oxide, antimony white, and zinc sulfide, and various dyes such as nigrosine, methylene blue, rose bengal, giraffe yellow, and ultraman blue. Furthermore, for the purpose of imparting fluidity and releasability to the toner of the present invention, known ones among low molecular weight olefin polymers, fatty acids, and fatty acid metal salts may be added at any stage of producing the toner of the present invention. Also good. As a low molecular olefin polymer, the molecular weight is approximately
The number is preferably 1,000 to 10,000, and examples thereof include polyethylene, polypropylene polymers, ethylene-propylene copolymers, and the like. Fatty acids and fatty acid metal salts include fatty acids having 12 to 18 carbon atoms, such as lauric acid, myristic acid, palmitic acid, stearic acid, zomarinic acid, oleic acid, linoleic acid, and linolenic acid, and their calcium, barium, sodium, lithium, Examples include magnesium, manganese, zinc, nickel, cobalt, iron, and lead salts. Further, the toner of the present invention is effective not only as a toner for a two-component developer but also as a toner for a one-component developer by using a magnetic material.
The magnetic material can be added at any stage of manufacturing the toner of the present invention, such as iron sesquioxide, triiron tetroxide, nickel sesquioxide, and other oxides,
Examples of the magnetic material include fine particles or ultrafine particles of metal such as iron, cobalt, copper, silver, gold, aluminum, and tin. In addition, the particle size of toner for one-component developer is as follows:
1 to 40μ, preferably 10 to 20μ is suitable. The present invention will be explained in more detail in the following examples.
The present invention is not limited to these examples. In addition, "parts" shown in the following examples and comparative examples indicate "parts by weight" unless otherwise specified. Example 1 1660 parts of isophthalic acid, 25.5 parts of maleic anhydride, 3878 parts of bisphenol A PO2 molar adduct, and dibutyltin were placed in a 10-volume four-necked flask equipped with a stirrer, condenser, inert gas inlet tube, and thermometer. Add 27.8 parts of oxide and heat at 220℃ in a nitrogen stream.
The maleic acid content was approximately 0.5% by weight, the acid value was 10mgKOH/g, and the hydroxyl value was 15mgKOH/g.
An unsaturated polyester (hereinafter referred to as polyester) having an average molecular weight of about 4500, a Tg of 70°C by DTA, and a softening point of 100°C was obtained. This polyester was finely pulverized to an average particle size of 12 .mu.m, and the amount of charge determined by the blow-off method was -32 .mu.c/g. A polymerizable solution was prepared by dissolving 200 parts of this polyester in 225 parts of styrene and 75 parts of dibutyl fumarate. In a 2-volume polymerization reaction vessel equipped with a stirrer, condenser, nitrogen gas blowing tube, and thermometer, add 1000 parts of water and polyvinyl alcohol (Poval manufactured by Kuraray).
217) After charging 0.5 part of 2,2'-azobisisobutylene and raising the temperature to 70°C with stirring at 150 rpm, the system was flushed with nitrogen gas and 500 parts of the polymerizable solution containing 40% by weight of the above polyester and 2,2'-azobisisobutylene were added. 5.0 parts of lonitrile was added dropwise over 1 hour. After reaction at 70°C for 1 hour, the temperature was raised to 80°C in 30 minutes, and the polymerization was completed in 10 hours. After the polymerization was completed, the suspension was cooled, filtered, and taken out, and the dispersant was washed away with water. After drying, a bead-shaped resin composition (hereinafter referred to as resin) was obtained. The number average molecular weight (hereinafter referred to as number average molecular weight) of this resin by GPC was 7800, the Tg was 67°C, and the softening point was 155°C. 90 parts of this resin and 10 parts of carbon black (Morgan A manufactured by Kayabot Corporation) were melt-kneaded at 180°C.
After cooling, it is roughly pulverized in a hammer mill to several hundred microns, and then finely pulverized in a jet mill to produce toner with an average particle size of 12 microns.
I got (A). Example 2 A method similar to the method for producing polyester in Example 1 from 1660 parts of isophthalic acid, 57 parts of maleic anhydride, 4190 parts of bisphenol A PO2 molar adduct and 29.5 parts of dibutyltin oxide was used to reduce the maleic acid content to approx.
1.0% by weight, acid value 15mgKOH/g, hydroxyl value 36mg
A polyester having KOH/g, average molecular weight of about 2200, Tg of 73°C and softening point of 115°C was obtained. The amount of charge of this polyester fine powder (12μ) was -24μc/g. From a polymerizable solution consisting of 100 parts of this polyester, 220 parts of styrene and 180 parts of di-2-ethylhexyl fumarate and 3.75 parts of AiBN, a number average molecular weight of 8500, a Tg of 65°C and a softening point of 3.75 parts of AiBN were prepared in the same manner as in Example 1.
A resin at 150°C was obtained. 90 parts of this resin and 10 parts of carbon black (Morgan A) were melt-kneaded at 180°C, cooled, and then pulverized to obtain a toner (B) having an average particle size of 12 μm. Example 3 50 parts of polyester obtained in Example 2, styrene
296 parts, 115.5 parts of dibutyl fumarate, and 38.5 parts of 2-ethylhexyl acrylate, and 2,2'-azobisisobutyronitrile.
From 6.25 parts, a resin having a number average molecular weight of 14,600, a Tg of 56°C and a softening point of 130°C was obtained in the same manner as in Example 1. 90 parts of this resin and 10 parts of carbon black (Morgan A) were melt-kneaded at 170°C, cooled, and then pulverized to obtain a toner (C) having an average particle size of 12 μm. Example 4 1660 parts of terephthalic acid, 1368 parts of 2,2-dimethyl 1,3-propanediol, and 16 parts of dibutyltin oxide were placed in a 5-volume four-necked flask equipped with a stirrer, condenser, inert gas inlet tube, and thermometer.
The temperature was raised from 150°C to 240°C over 6 hours in a nitrogen stream, and after further reaction at 240°C for 6 hours, the temperature was lowered to 180°C, and 203 parts of maleic anhydride was added.
Reacted at 180℃ for 2 hours, maleic acid content approximately 7
Weight%, acid value 11mgKOH/g, hydroxyl value 45mg
KOH/g, average molecular weight approximately 2000, Tg65℃, softening point
A polyester at 95°C was obtained. The amount of charge of this fine polyester powder (12μ) was -16μc/g. A polymerizable solution consisting of 25 parts of this polyester, 295 parts of styrene, and 180 parts of dibutyl fumarate;
From 5.0 parts of 2'-azobisisobutyronitrile, a number average molecular weight of 17600 and Tg59 was prepared in the same manner as in Example 1.
℃, a resin with a softening point of 125℃ was obtained. 90 parts of this resin and carbon black (manufactured by Mitsubishi Kasei)
10 parts of MA-8) were melt-kneaded at 170° C., cooled, and then finely pulverized to obtain a toner (D) having an average particle size of 12 μm. Example 5 75 parts of polyester obtained in Example 1, styrene
276 parts of dibutyl fumarate and 149 parts of dibutyl fumarate and 2,2'-azobisisobutyronitrile
A resin having a number average molecular weight of 10,500, a Tg of 58°C, and a softening point of 152°C was obtained from 2.5 parts of t-butylperoxy 2-ethylhexanoate and 3.3 parts of t-butylperoxy 2-ethylhexanoate in the same manner as in Example 1. 92 parts of this resin and carbon black (MA-8)
8 parts were melt-kneaded at 180° C., cooled, and then finely pulverized to obtain a toner (E) with an average particle size of 12 μm. Example 6 1000 parts of the polyester obtained in Example 2 and 83 parts of phthalic anhydride were charged into a 2-volume four-necked flask equipped with a stirrer, a condenser, an inert gas introduction tube, and a thermometer, and the mixture was heated in a nitrogen stream for 1 hour. 160℃
The temperature was increased to 160°C for an additional 3 hours, and the maleic acid content was approximately 0.9% by weight, the acid value was 44mgKOH/g,
Hydroxyl value 8mgKOH/g, average molecular weight approximately 2300,
A polyester with a Tg of 63°C and a softening point of 100°C was obtained.
The amount of charge of this polyester fine powder (12μ) is -
It was 24μc/g. A polymerizable solution consisting of 100 parts of this polyester, 270 parts of styrene, 100 parts of di-2-ethylhexyl fumarate and 30 parts of 2-ethylhexyl acrylate, and 2.5 parts of 2,2'-azobisisobutyronitrile,
The number average molecular weight was 12,000 using the same method as in Example 1.
A resin with a Tg of 60°C and a softening point of 153°C was obtained. 45 parts of this resin, 5 parts of carbon black (Mitsubishi Kasei #44) and 50 parts of triiron tetroxide (Magnetite EPT-500, manufactured by Toda Kogyo) were melted and kneaded at 180°C.
One-component toner (F) that is finely pulverized after cooling and has an average particle size of 13μ.
I got it. Comparative Example 1 In Example 1, a number average molecular weight of 30,700 was obtained in the same manner as in Example 1 without using polyester.
A comparative styrene-dibutyl fumarate copolymer resin having a Tg of 76°C and a softening point of 134°C was obtained. 90 parts of this resin and 10 parts of carbon black (Morgan A) were heated to 160°C.
The mixture was melt-kneaded, cooled, and then finely pulverized to obtain a comparative toner (a) having an average particle size of 12 μm. Comparative Example 2 50 parts of polyester obtained in Example 2, styrene
382.5 parts and 2-ethylhexyl acrylate 67.5 parts
2,2'-azobisisobutyronitrile and 6.25 parts of 2,2'-azobisisobutyronitrile, a number average molecular weight of 15,500, a Tg of 64°C and a softening point of 152
A comparative resin was obtained at . When 90 parts of this resin and 10 parts of carbon black (Morgan A) were melt-kneaded at 180°C, cooled, and then finely pulverized, only a comparative toner (b) with an average particle size of 32 μm and very poor pulverizability was obtained. Ta. Comparative Example 3 In the polyester of Example 1, only maleic anhydride was used as the dibasic acid, and 980 parts of maleic anhydride,
Polyester obtained from 3780 parts of bisphenol A PO2 molar adduct and 23.8 parts of dibutyltin oxide (maleic acid content approximately 22% by weight, acid value 13.5 mg)
A resin was obtained in the same manner as in Example 2, except that KOH/g, hydroxyl value 22 mgKOH/g, average molecular weight approximately 3200, Tg 65°C, softening point 115°C) were used. This resin is insoluble in THF for GPC measurements, and this suggests that the resin has a crosslinked structure.Also, we tried to produce a two-component comparison toner (c) by adding carbon black, but the temperature was 220°C. Even on the roll, it did not melt and could not be kneaded. Comparative Example 4 300 parts of polyester obtained in Example 1, styrene
120 parts of dibutyl fumarate and 80 parts of dibutyl fumarate and 2,2'-azobisisobutyronitrile
A comparative resin having a number average molecular weight of about 5400, a Tg of 60°C and a softening point of 162°C was obtained from 2.5 parts in the same manner as in Example 1. 90 parts of this resin and carbon black (MA-8)
10 parts were melt-kneaded at 190° C., cooled, and finely pulverized to obtain a comparative toner (d) with an average particle size of 12 μm. Comparative Example 5 From 1660 parts of isophthalic acid, 52 parts of maleic anhydride, 3626.5 parts of bisphenol A EO 2 molar adduct and 26.7 parts of dibutyltin oxide, a maleic acid content of about 1.1 was prepared in the same manner as the polyester manufacturing method of Example 1. Weight%, acid value 15mgKOH/g, hydroxyl value 22
A comparative polyester having mgKOH/g, average molecular weight of about 3000, Tg of 95°C and softening point of 125°C was obtained. The amount of charge of this polyester fine powder (12μ) is -20μc/
It was hot at g. 50 parts of polyester for this comparison, 275 parts of styrene,
107.5 parts of dibutyl fumarate and di-fumarate
From a polymerizable solution consisting of 67.5 parts of 2-ethylhexyl and 5 parts of 2,2'-azobisisobutyronitrile, a number average molecular weight of 15,300 was prepared in the same manner as in Example 1.
A comparative resin with a Tg of 58°C and a softening point of 172°C was obtained. 90 parts of this resin and carbon black (MA-8)
10 parts were solution-kneaded at 190°C, cooled, and then finely pulverized to obtain a comparative toner (e) having an average particle size of 13 μm. Comparative Example 6 A maleic acid content of about 1.0 was prepared using 1660 parts of isophthalic acid, 66 parts of maleic anhydride, 5186 parts of bisphenol A PO2 molar adduct, and 34.6 parts of dibutyltin oxide in the same manner as the polyester production method of Example 1. Weight%, acid value 8mgKOH/g, hydroxyl value 66mg
A polyester having KOH/g and an average molecular weight of about 1500 was obtained. Further, 196 parts of phthalic anhydride was added to 1000 parts of this polyester in the same manner as in Example 6, resulting in a maleic acid content of about 0.8% by weight, an acid value of 70mgKOH/g,
Hydroxyl value approximately 4.5mgKOH/g, average molecular weight approximately 1600,
A comparative polyester having a Tg of 52°C and a softening point of 86°C was obtained. The amount of charge of this fine polyester powder (12μ) was -22μc/g. A polymerizable solution consisting of 50 parts of this comparative polyester, 305 parts of styrene, and 145 parts of dibutyl fumarate and 3.75 parts of 2,2'-azobisisobutyronitrile were prepared in the same manner as in Example 1 to obtain a number average molecular weight of 20,800.
A comparative resin with a Tg of 57°C and a softening point of 146°C was obtained. 90 parts of this resin and carbon black (MA-8)
10 parts were melt-kneaded at 170° C., cooled, and then finely pulverized to obtain a comparative toner (f) with an average particle size of 12 μm. Comparative Example 7 1660 parts of isophthalic acid, 444.5 parts of maleic anhydride,
Bisphenol A PO2 molar adduct 4846 parts, propylene glycol 93 parts and dibutyltin oxide
32.2 parts were reacted in a nitrogen stream at 220°C for about 10 hours in the same manner as the polyester production method of Example 1, and then further reacted at 220°C for about 6 hours under 1 mgHg reduced pressure to obtain a maleic acid content of about 6.7. Weight%, acid value 5
A comparative polyester having a hydroxyl value of about 4 mgKOH/g, an average molecular weight of about 12,500, a Tg of 76°C, and a softening point of 120°C was obtained. The amount of charge of this polyester fine powder (13μ) was -25μc/g. Comparative Example A polymerizable solution consisting of 100 parts of polyester, 280 parts of styrene and 120 parts of dibutyl fumarate and 5 parts of 2,2'-azobisisobutyronitrile were prepared in the same manner as in Example 1, partially insoluble in THF. Number average molecular weight 29800, Tg 58℃ and softening point
A comparative resin was obtained at 173°C. 45 parts of this resin, 5 parts of carbon black (#44), and 50 parts of triiron tetroxide were melt-kneaded at 200°C, cooled, and then pulverized to obtain a one-component comparative toner with an average particle size of 16 μm. Ta. Test Methods Various characteristics of the toners obtained in the above Examples and Comparative Examples other than Comparative Example 3 were evaluated by the following methods. (Frictional charge amount) Except for the one-component toner of Example 6 and Comparative Example 7, iron powder carrier (DSP128B manufactured by Dowa Iron Powder Industries)
The amount of charge was measured by the blow-off method. In the case of the above-mentioned one-component toner, measurements were made in the same manner except for the system excluding magnetite. (Fixing properties, offset properties) Copy paper and toner (thickness 0.5
~1.0mm), silicone rubber (KE− manufactured by Shin-Etsu Chemical)
1300RTV) or Teflon rubber (DuPont FEP)
Stack them one after another and place a 100g weight on top. After the heat plate was held at 1770° C. for 5 minutes, the fixation of the toner onto copy paper (cellophane tape removability) and the offset performance onto silicone rubber or Teflon rubber were examined. Regarding the fixing property, the case where 90% or more of the toner was not removed from the copy paper by the cellophane tape was judged as ○, the case where 50% or more was removed was judged as ×, and the case where 50 to 90% was removed was judged as Δ. Regarding the offset property, a state in which the toner was not fused to the silicone rubber or Teflon rubber was rated as ○, a state in which the toner was fused to the entire surface was rated as ×, and a state in which some fusion was observed was rated as Δ. (Developability, transferability) An image was formed on a zinc oxide photosensitive plate, transfer paper was placed on top of the image, and a corona AC voltage was applied using a corotron to transfer the image to the transfer paper. Depending on the state of fog in the resulting image, those with no fog were evaluated as ○, those with fog on the entire surface were evaluated as ×, and those with fog on some areas were evaluated as Δ. (Image density) Measured with a reflection densitometer after fixing. An image density of 1.20 or higher was judged to be good. (Crushability) The yield (%) of particles having a particle diameter of 5 to 15 μm was measured by pulverization during toner production. A crushability of 70% or more was judged to be good. (Blocking property) After the toner was left in a constant temperature and humidity bath at 60° C. and 60% RH (relative humidity) for one week, the state in which the toner did not block was evaluated as ○, and the state in which blocking was observed was evaluated as ×. Regarding the various toner characteristics obtained by the above test method,
The results are shown in Tables 1 and 2. From Tables 1 and 2, it can be seen that the toners of the present invention, Examples 1 to 6, exhibited good developability, transferability, fixing properties, offset resistance, pulverization resistance, and blocking resistance, and Comparative Examples -1 to It can be seen that the toner has characteristics as a toner that cannot be obtained with Comparative Example-7. In other words, the reason why such good properties as a toner are given is that an aromatic vinyl monomer is an essential component in the presence of a specific polyester containing 0.2 to 10% by weight of an aliphatic unsaturated dibasic acid. at least
A resin composition obtained by copolymerizing an active vinyl monomer mixture consisting of 50% by weight and 2 to 50% by weight of an α,β-disubstituted aliphatic unsaturated dibasic acid diester monomer is used as a fixing resin. This can be achieved by using it as

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Claims (1)

[Claims] 1. An aliphatic unsaturated dibasic acid as a fixing resin.
Contains 0.2-10% by weight, glass transition point is 50-90
℃, softening point by ring and ball method is 80-120℃, acid value is 5
~60mgKOH/g, average molecular weight by end group method
500-10,000 unsaturated polyester in the presence of 2-50 parts by weight of at least 50% by weight of aromatic vinyl monomer and 2-50% by weight of α,β-disubstituted resin unsaturated dibasic acid as essential components A toner for electrostatic image development used in a heated roll fixing system, characterized in that it uses a resin composition obtained by copolymerizing 98 to 50 parts by weight of a monomer containing a diester monomer. 2. The toner according to claim 1, wherein the resin composition is negatively chargeable.