JP2936643B2 - Toner for developing electrostatic images - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like.

[Prior Art] Electrophotography generally uses a photoconductive substance, forms an electrostatic image on a photoreceptor by various means, develops the electrostatic image with toner, and then transfers the image to paper or the like. Settled on the material.

On the other hand, in the rapid development of the information society in recent years, in the field of electrophotography such as copiers and printers, higher speed of recording copy and clarity of image quality are required, and as a binder resin used for toner, A resin having excellent fixing performance is desired.

Generally, as such a binder resin, for example, Japanese Patent Publication No. 55-68
Styrene acrylic resin found in JP-A-95, JP-A-62
Epoxy resins and the like described in JP-A-67562 are used, and polyester resins are particularly suitable for high-speed copying because of their excellent fixing properties as seen in JP-A-60-112052. However, when a polyester resin is used as a binder resin for a toner, heat accumulation and thermal aggregation tend to occur due to friction between the toner and a carrier or a magnetic powder during continuous copying, and improvement thereof is desired. In the heat roll fixing method, toner development transferred to paper or the like directly contacts the surface of the heat roll, and the toner is melted and fixed on paper or the like by the heat and pressure of the heat roll. Is transferred to the surface of the roller, and this transferred material is transferred again to the next transfer material such as paper. This may cause a so-called offset phenomenon, which may cause a copy trouble. Is desired.

[Problems to be Solved by the Invention] The present invention is to provide a toner having improved fixability, heat aggregation resistance and offset resistance by using a specific polyester resin as a binder resin.

[Means for Solving the Problems] The present invention has reached the present invention particularly by using cyclohexanedimethanol as an essential component as an alcohol component constituting a polyester resin.

As the polybasic acid component constituting the polyester resin in the present invention, for example, succinic acid, adipic acid, sebacic acid, azelaic acid, dozenenylsuccinic acid, n-dodecylsuccinic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, Dibasic acids such as itaconic acid, glutaconic acid, cyclohexanedicarboxylic acid, orthophthalic acid, isophthalic acid, and terephthalic acid; tribasic acids or more such as trimellitic acid, trimetic acid, and pyromellitic acid; and anhydrides and lower alkyl esters thereof These are used alone or as a mixture, but aromatic polybasic acids are preferred from the viewpoint of heat cohesion, and terephthalic acid is particularly preferred.

As a polyhydric alcohol component constituting the present invention, cyclohexane dimethanol is an essential component, and other polyhydric alcohols are ethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, and 1,4-propylene glycol. Butanediol, 1,3-butanediol, 1,4-butenediol, 1,5-pentanediol,
6-hexanediol, hydrogenated bisphenol A, dihydric alcohols such as hydrogenated bisphenol A alkylene oxide adduct, bisphenol A alkylene oxide adduct, glycerin, trimethylolethane, trimethylolpropane, trishydroxyethyl isocyanurate, pentaerythritol And the like are used singly or as a mixture, and bisphenol A alkylene oxide adduct is preferable, and bisphenol A ethylene oxide adduct is particularly preferable from the viewpoint of heat cohesion.

As described above, the polyhydric alcohol component is preferably a combination of cyclohexane dimethanol and a bisphenol A ethylene oxide adduct as a polyhydric alcohol component from the viewpoint of heat cohesion, but the combination ratio is preferably cyclohexane dimethanol in all polyhydric alcohol components of 5 to 5. 80 mol%, more preferably 10
It is in the range of ~ 70 mol%. When the amount of cyclohexanedimethanol is in this range, particularly good image quality is obtained, and the effect of improving heat cohesion is great.

The physical property value of the polyester resin in the present invention is not particularly limited, but it is suitable for use as a toner, and has a ring-ball method softening point of 80 to 160 ° C., a melt viscosity of 5 × 10 ⁴ poise or more at 100 ° C., and 120 ° C. Those having a Tg of 1 × 10 ⁷ poise or less and a Tg in the range of 50 to 80 ° C. are preferred. Further, the acid value of the polyester resin in the present invention is preferably 30 mg · KOH / g or less, and the hydroxyl value is preferably 60 mg · KOH / g or less. Within this range, the environment dependency of the chargeability is particularly good.

The production of the toner using the polyester resin and the formulation of the toner in the present invention will be described.

First, the binder resin according to the present invention is crushed, a colorant,
A charge control agent for adjusting the triboelectric chargeability, a lubricant for preventing offset and imparting fluidity of the toner powder, etc. are added, premixed, melt-kneaded with an extruder, a pressure kneader, etc., and then pulverized and classified to form a toner Is what you get.

Examples of colorants include black pigments such as channel black, furnace black, and thermal black, and color pigments such as cadmium yellow, Hanza yellow G, naphthol yellow S, and pyrazolone red.
Permanent Red 4R, Molybdenum Orange, Fast Bio Red B, Phthalocyanine Blue B, Furnest Sky Blue, Phthalocyanine Green, Malachite Green, Naphthol Green B, etc.
Further, as a magnetic powder of a one-component toner using a magnetic powder as a component of the toner, for example, iron, cobalt, powder of a ferromagnetic metal such as nickel or magnetite, hematite,
Powders of alloys and compounds such as ferrite are also used as colorants and magnetic materials. Nigrosine dyes, alkoxylated amines, quaternary ammonium salts, alkylamides, phosphorus and tungsten alone or in compounds, molybdate chelate pigments, fluorine-based activators, hydrophobic Silica or the like is used,
As a substance giving a negative charge, a metal complex salt of a monoazo dye,
Electron-accepting organic complexes, chlorinated polyolefins, chlorinated polyesters and the like are used. As the lubricant, colloidal silica, silicone varnish, metal soap, low molecular weight polyethylene, low molecular weight polypropylene, carnauba wax and the like are used.

[Examples] Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.
The parts in the examples are on a weight basis.

(Synthesis Example 1) stirrer, a thermometer, N ₂ gas inlet, cyclohexanedimethanol 1544 parts to a flask with a packed column with reflux condenser (10.7 mol equivalent), 1660 parts of isophthalic acid (10 mol equivalent), FASCAT 3.2 parts of 4100 (monobutyltin oxide manufactured by Dainippon Ink and Chemicals, Inc.)
_A dehydration-condensation reaction was carried out at 240 ° C. under stirring and heating under a gas stream of ₂ to carry out the reaction until the acid value reached 3 mg · KOH / g, and a solid polyester resin was obtained.

(Synthesis Examples 2 to 8, Comparative Synthesis Examples 1 to 3) A polyester resin was synthesized in the same manner as in Synthesis Example 1. Table 1 shows the raw material compositions used in Synthesis Examples 2 to 8 and Comparative Synthesis Examples 1 to 3, and Table 2 shows the physical property values of the obtained polyester resins.

(Examples 1 to 8, Comparative Examples 1 to 3) Using the polyester resins obtained in Synthetic Examples 1 to 8 and Comparative Synthetic Examples 1 to 3, toners were prepared by the following method.

100 parts binder resin, 5 parts carbon black, 5 biscol
50-P (Low molecular weight polypropylene wax manufactured by Sanyo Chemical)
4 parts and 2 parts of Bontron S-34 (a chromium complex-based charge control agent manufactured by Orient Chemical Co.) are mixed and melt-kneaded with a pressure kneader, then pulverized with a jet mill, and classified and collected with a particle diameter of 5 to 15 μm to obtain an average particle diameter of 12 μm. Was obtained.

The obtained toner (7 parts) and iron powder carrier (93 parts) were mixed, the developer was adjusted, and an image was formed using a commercial electrophotographic copying machine.
A fixing test was performed with a heat roller fixing device having a speed of m / sec. Table 3 shows the results.

[Effects of the Invention] By using the polyester resin of the present invention as a binder resin, it is possible to obtain a toner having excellent heat aggregation resistance, fixability and offset resistance.

Continuation of the front page (72) Inventor Hiroshi Utsumi 1013-3 Miyako-cho, Chiba City, Chiba Prefecture (56) References JP-A-3-31858 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB (Name) G03G 9/08

Claims (6)

(57) [Claims] 1. A toner for developing an electrostatic charge image comprising a polyester resin containing cyclohexanedimethanol as an essential component as a polyhydric alcohol component as a binder resin. 2. The toner according to claim 1, wherein the polyester resin contains an aromatic polybasic acid as an essential component as the polybasic acid component. 3. An electrostatic charge image developing toner using a polyester resin containing cyclohexane dimethanol and bisphenol A alkylene oxide adduct as essential components as polyhydric alcohol components as a binder resin. 4. An electrostatic image formed by using a polyester resin comprising terephthalic acid as an essential component as a polybasic acid component and cyclohexanedimethanol and an adduct of bisphenol A alkylene oxide as polyhydric alcohol components as a binder resin. Development toner. 5. The toner according to claim 4, wherein the content of cyclohexanedimethanol is 5 to 80 mol% in all polyhydric alcohols. 6. A polyester resin having a polybasic acid component of 3%.
2. The toner according to claim 1, wherein a polybasic acid having a functionality of at least one is used.