JPS58211763A - Electrophotographic toner - Google Patents

Abstract

PURPOSE:To reduce scattering of the amount of electrification and to elevate type quality, by adding calcium stearate as a charge controller. CONSTITUTION:The present toner comprises at least resin and colorant. Calcium stearate is added to said resin as a charge controller. Said resin has 50-200 deg.C softening point, and an amt. of calcium stearate to be added is 0.5-20pts.wt. per 100pts.wt. resin.

Description

DETAILED DESCRIPTION OF THE INVENTION lal Technical Field of the Invention The present invention relates to improvements in toner used in electrophotographic XK.

(bl) Background of the technology Charges are formed on the surface of an a-image forming medium made of photosemiconductor materials such as selenium (Se) and zinc oxide (ZnO) by corona discharge, and the latent image forming medium in which the sections are formed is Expose a predetermined area to remove the charge and form an electrostatic primary image,
61j static spiral latent image A method for forming electrophotography is already well known, in which a predetermined print is developed by adhering VC toner, and the developed print is transferred and fixed onto paper.

(C1 Prior Art and Problems Conventionally, toner used in such electrophotography is generally prepared by dispersing a coloring agent such as carbon black in an epoxy resin and turning it into starved powder, and then adding a nigrosine dye as a charge control agent. Here, an electrophotographic developer made by mixing the above-mentioned toner with a carrier such as iron powder is rotated by a roller such as a magnetic roll to charge the carrier negatively. , toner is charged to 100% and attached to the surrounding area, and this 100% charged toner is attached to the electrostatic latent image to develop a predetermined print.Here, conventionally, the toner mentioned above is (1iJ). A nigrosine dye was used as a control agent removal agent for charge 1 to be charged to +).

However, when a toner using the aforementioned nigrosine dye as a charge control agent is subjected to dry friction with a carrier, there is a large variation in the amount of charge the toner is charged with. When the toner is used as a toner for electrophotography, the image obtained by development has a drawback that the background portion has a large fog, or the toner scatters a lot and contaminates the inside of the developing material. Furthermore, since the nigrosine dye exhibits a black color, it has the disadvantage that it is impossible to develop colors other than black.

1111 Purpose of the Invention The present invention eliminates the above-mentioned drawbacks, makes the amount of charge applied to the toner uniform, and thereby realizes a single clear image without fogging, and also eliminates the problem of poor print quality even after long-term printing. figure,
Moreover, it is an object of the present invention to provide a new toner for electrophotographic pages, which causes less contamination of the inside of the developing material and which allows color edges other than black to be produced.

In order to achieve the above object, the electrophotographic toner of the present invention contains calcium stearate as the additive in the composition of at least a fat and a 5W coloring agent. It is characterized by the presence of

Further, the resin has a softening point of 50 to 200, and contains 0.5 to 20 parts by weight of the charge control agent, calcium nutearate, per 100 parts by weight of the resin. It is.

That is, the toner of the present invention is characterized by containing calcium stearate in the resin, and if necessary, contains a coloring agent such as a dye or pigment, and a charge control agent other than the calcium stearate.

(Example of f1 @ Ming) When printing the resin used in the toner of the present invention, if the softening point of the resin is too high, it will be difficult to fix it on the recording paper, and if the softening point is too low, there will be gaps between the toner particles. For example, polystyrene, or styrene and acrylate, which have a softening point of about 50 to 2000,
Alternatively, copolymers of styrene and methacrylate, polyester resins, epoxy resins, polyamide resins, etc. are preferable.

In addition, 'lsuf7! J nph tLzV +7 m[:(C1
7H35COO)2Ca2+], a charge control agent such as nigrosine dye or copper phthalocyanine pigment may be used.

Also, carbon black is used to darken the toner to black, Benjison thread yellow pigment is used to make the toner yellow, anthraquinone blue dye is used to make the toner 8 colors blue, and anthraquinone blue dye is used to make the toner red. For coloring, a red pigment is appropriately added to the quinacridone thread and the rhodamine thread, and if this toner is used for printing, each color can be printed in the desired color.

Furthermore, if necessary, a lubricant such as Waknu may be added to each ridge to prevent the toner from becoming sticky during use.

Here is the power of numeric acid used in the toner of the present invention! The content of lesium is determined by various resins such as polystyrene mentioned above.
It is desirable to contain 0.5 to 20 parts per 00 parts. That is, if the content of lesium stearate is more than 0.6 parts by weight per 100 parts by weight of the resin, the toner formed will not have an appropriate charge amount, and if the content of calcium stearate is less than 20 parts by weight, If it is above the weight part, it becomes difficult to uniformly knead the resin and the calcium stearate.

As a result, the toner particles are finely pulverized, and the toner particles start to move, resulting in large variations in the length of each band. Furthermore, the high content of calcium stearate makes it difficult to fix.

As described above, the toner of the present invention contains calcium stearate as an essential component in the above-mentioned (support) resin such as polystyrene, and if necessary, a charge control agent other than the calcium stearate is added, and the toner is black or other than black. 1
8 Coloring agents are added, and if necessary, a lubricant such as Watsuknu is added, the mixture is kneaded using a heated kneader or heated rolls, and after cooling, it is crushed using a super J set core crusher or jet mill, etc. to obtain a toner having an average particle size of 5 to 2 Q p m.

A preferred embodiment of the present invention that further embodies the matters described above will now be described.

As an example of such a polystyrene resin (Esso Kagaku Co., Ltd. [PJ product name 1 Picolastic D-125J) e98
Parts by weight, 8 parts by weight of carbon black (product name 1 Morgan AJ manufactured by Capot Co., Ltd.), nigrosine dye (product name 1 Orient Chemical Company'H++H product name 1 Orient Nigrosine Base B)
After collecting 2 parts by weight of Y, ) and 2 parts of calcium stearate, kneading the materials with a kneader at a temperature of 1 hour, cooling, and using a jet mill. and crushed it. Then, the particles were classified using an air classifier to obtain a particle size distribution of 5 to 20 pm and an average particle size of 10 μm.
A black toner of n was obtained.

Eight parts by weight of the thus obtained toner and 97 overlapping portions of iron powder serving as a carrier were mixed to form a 71-color photographic developer consisting of toner and carrier.

Using this developer, a laser printer <F-6715D
When we conducted a printing test using a printer (manufactured by Fujitsu), clear printing without fogging was obtained even after printing started and even after continuous printing using 10,000 sheets of recording paper.
Further, good results were obtained with very little contamination of the developing material.

Incidentally, calcium stearate was removed from the material constituting the toner of this example, and the toner was formed using this material.
A printing test was conducted using a toner containing no calcium stearate. As a result, fogging occurred in the printing from the beginning of printing, and after printing using 5,000 sheets of recording paper, an undesirable phenomenon occurred in which the inside of the print was contaminated by scattered toner. From this, it was found that a high-quality toner can be obtained by forming an electrophotographic toner using the resin containing calcium stearate of the present invention.

Effects of the Invention As mentioned above, the toner for Naruko I:t, j' (of the present invention) has little variation in color and power, and if such a toner is used to form a developer, a toner with a bright print quality can be obtained. The goal is to provide a long-life developer with less scattering.Moreover, since the toner containing the control agent made of calcium stearate of the present invention is white, it can form toners for color printing other than black. There are advantages to both.

Claims (1)

[Scope of Claims] Ell An electrophotographic toner comprising at least a resin and a colorant, wherein the resin contains calcium stearate as a charge control agent. (2) A patent claim characterized in that the resin has a softening point of 50 to 20 (E) and contains 0.5 to 20 parts by weight of calcium stearate as the charge control agent per 100 parts by weight of the resin. The toner for electrophotography according to item +11 of the range.