KR100839454B1 - Developing roller and thereof manufacturing method for laser printer - Google Patents

Abstract

The present invention relates to a developing roller for a laser printer capable of increasing the sharpness of an image in a toner by lowering the hardness of the roller, wherein the developing roller shaft forms the center of rotation of the developing roller, and the outer peripheral surface of the shaft is formed of nitrile rubber. Rubber, NBR) and a tube made of a mixture of Epichloro Hydrio Rubber (ECO) and a Shore A type with conductivity between the developing roller shaft and the tube. Provided are a developing roller for a laser printer and a method of manufacturing the same, comprising a conductive urethane layer in which urethane is injected to form a foamed or unfoamed urethane layer.

Developing roller, developing roller shaft, tube, conductive urethane layer

Description

Developing roller and manufacturing method for laser printer

1 is a cross-sectional view of a conventional developing roller.

2 is a cross-sectional view of a developing roller for a laser printer according to the present invention.

Figure 3 is a flow chart of a developing roller manufacturing method for a laser printer according to the present invention.

** SIGNS FOR MAIN PARTS OF THE DRAWINGS **

10: developing roller shaft 20: conductive urethane layer

30 tube

The present invention relates to a developing roller for a laser printer that can increase the sharpness of the image by lowering the hardness of the roller used in the toner cartridge of the laser printer, and more particularly, nitrile rubber (Acrylonitrile Butadiene Rubber, NBR) and epichlorohydr It forms a tube by mixing the chloro rubber (Epichloro Hydrio Rubber, ECO) and inserts a developing roller shaft into the tube. It relates to a developing roller for a laser printer formed by injection.

In general, the developing apparatus includes a developing roller, a toner supply roller for supplying toner to the developing roller, and a regulating blade for forming a thin layer of toner by regulating the toner moved to the developing roller to a certain thickness.

The developing roller plays an important role of moving the toner to the electrostatic latent image on the photosensitive drum to form a visible image. The developing roller should be formed to have certain characteristics in order to smoothly apply the toner to the photosensitive drum in an appropriate amount. In addition, the developing roller is classified into a polymer roller and a metal roller according to the base material. Polymer rollers are further divided into ion conduction and electron conduction. A common one of the ion conductive polymer rollers is an ion conductive elastic rubber roller based on rubber having a strong polarity or a large number of substituents. Ion-conductive elastic rubber rollers are universal because they are advantageous in terms of price and the like. However, such an ion-conductive elastic rubber roller has a disadvantage in that the image quality is poor due to the inferior sharpness.

1 is a cross-sectional view of a conventional developing roller.

As shown in FIG. 1, the conventional developing roller is formed by mixing a nitrile rubber (Nrylonitrile Butadiene Rubber, NBR) and Epichloro Hydrio Rubber (ECO) and applying a developing roller shaft coated with an adhesive to form a roller. Make The roller formed as described above was made by roughing, roughing and finishing.

The conventional developing roller has a resistance in the range of 1E5Ω to 1E10Ω, and the hardness is a Shore A type, which can no longer lower the hardness to 40 degrees to 100 degrees. There was a problem of shortening the service life.

The present invention has been made to solve the above problems to form a tube by mixing Nitrile rubber (Acrylonitrile Butadiene Rubber, NBR) and Epichloro Hydrio Rubber (ECO) to insert a developing roller shaft in the tube It is an object of the present invention to provide a developing roller for a low hardness type laser printer and a method of manufacturing the same by injecting a conductive urethane capable of varying the hardness range in the space between the tube and the developing roller shaft, as compared with a conventional developing roller. .

In addition, it is another object to provide a developing roller for a laser printer and a method of manufacturing the same, which can reduce the stress on the toner due to the low hardness, the image sharpness is good.

The present invention provides a developing roller for a laser printer which can lower the hardness of the roller and increase the sharpness of the image in the toner.

A developing roller shaft forming a center of rotation of the developing roller;

A tube made of a rubber formed on the outer circumferential surface of the shaft to mix Acrylonitrile Butadiene Rubber (NBR) and Epichloro Hydrio Rubber (ECO);

It characterized by consisting of a conductive urethane layer to form a foamed or unfoamed urethane layer by injecting a conductive urethane of low hardness of 10 degrees to 100 degrees in the conductive Shore A type between the developing roller shaft and the tube.

In addition, the conductive urethane layer is characterized by using a surfactant or carbon black, conductive fillers of metal powder, and ion complex antistatic agent alone or in combination to impart conductivity.

The conductive urethane layer is a conductive Shore A type, characterized in that it can be formed of low hardness silicon of 10 degrees to 100 degrees.

In addition, the present invention provides a method of manufacturing a developing roller for a laser printer, which can lower the hardness of the roller and increase the sharpness of the image in the toner.

An extrusion process of mixing a nitrile rubber (Nryl) and epichloro hydrio rubber (ECO) to make a tube;

A vulcanization step of vulcanizing the tube formed in the extrusion process by a constant temperature;
(The constant temperature applied in the vulcanization process according to the present invention refers to a temperature that can be obvious to those skilled in the art, the temperature range may be 100 ℃ to 200 ℃, the constant temperature as a preferred embodiment of the present invention May be applied at 150 ° C.)

A press fitting step of inserting the shaft into the tube vulcanized in the vulcanizing step;

A first polishing step of roughing the tube into which the shaft is inserted in the indentation process and separating the tube and the shaft;

Inserting a developing roller shaft coated with an adhesive into the roughing tube in the first polishing step and injecting a low hardness conductive urethane of 10 to 100 degrees in Shore A type between the tube and the developing roller shaft;

And a second polishing step in which the developing roller formed by discharging the conductive urethane in the discharging step is subjected to a medium cutting process and a finishing process.

Hereinafter, with reference to the accompanying drawings to describe the present invention in detail.

2 is a cross-sectional view of a developing roller for a laser printer according to the present invention.

As shown in FIG. 2, a developing roller shaft 10, which forms a rotation center of the developing roller, and a nitrile rubber (Acrylonitrile Butadiene Rubber, NBR) and epichloro hydrio rubber (ECO) are mixed. It consists of a tube 30 configured to surround the outer circumferential surface of the developing roller, and a conductive urethane layer 20 for injecting conductive low hardness conductive urethane between the developing roller shaft 10 and the tube 30. . The developing roller having the above configuration can be formed into a low hardness type by forming a hardness range between 10 degrees and 100 degrees as a Shore A type, and having a resistance of 1E2Ω to 1E12Ω. The developing roller can be made low in hardness, thereby reducing stress on the toner, thereby improving image clarity, and can be used in rollers such as high speed printers and color printers. The conductive urethane layer 20 may be formed of a conductive low-hardness silicon, not a urethane-based. At this time, the conductive urethane layer may be used any foamed or unfoamed.

A tube configured to mix the nitrile rubber (Nryl) and epichloro hydrio rubber (ECO) to surround the outer circumferential surface of the developing roller is made of a conductive rubber, a heat shrink tube made of a conventional conductive plastic Compared with general tubes, precise dimensional safety such as roughness, coefficient of friction, and outer diameter can be obtained.

In the case of the conductive urethane of various hardness ranges of the present invention, various additives and reactive conductive additives may be used to impart conductivity, which is an essential requirement as a developing roller. Examples include various known surfactants, conductive fillers such as carbon black, metal powders, and ion complex antistatic agents, all of which may be used alone or in combination. In particular, in the case of the ion complex antistatic agent, compatibility with urethane and various conductivity ranges can be realized.

The ion complex antistatic agent is heated to 100 ° C. to 200 ° C. with vigorous stirring so that a metal salt is placed in a cationic conductive organic compound and a coordination binding compound is formed. The reaction time is from 12 hours to 24 hours. When the reaction is completed, the anion conducting organic compound is added to the reaction product and heated again at 100 ° C. to 200 ° C. with vigorous stirring for 12 to 24 hours. The coordination reaction is then completed at 40 ° C. to 60 ° C. under reduced pressure for 1 to 4 hours to obtain the final solution. After the reaction mixture has cooled to room temperature, an unreacted metal salt is removed using a filter. An ion complex antistatic agent prepared as described above is prepared and the antistatic agent is added to urethane or silicone, which is a thermoplastic resin, to form a conductive urethane or a conductive silicone.

The metal salt of the ion complex antistatic agent includes alkali metal salts, that is, all salts of Li, Na, and K. More specifically, LiPF6, LiBF4, LiSbF6, LiClO4, LiCF3SO3, LiAsF6, LiC (CF3SO3) 3, LiN ( CF3SO3) 2, LiI, LiBr, LiCl, LiF, NaPF6, NaClO4, NaI, NaSCN, KSCN, KPF6, KClO4, and the like, and transition metal salts include all metal salts including Fe, Ni, Cu, Zn, and more specifically, FeCl3, FeCl2, FeBr3, FeBr2, FeI2, FeI3, Fe (CH3COO) 3, Fe (SCN) 3, CuCl, CuBr, CuI, CuCN, CuCl2, CuBr2, CuI2, Cu (NO3) 2, Cu (CH3COO) 2, Cu (SCN) 2, ZnCl2, ZnBr2, ZnI2, Zn (CH3COO) 3 and the like are used alone or as a mixture. In general, the amount of metal salt used is 5 to 40% by weight of the total antistatic agent. Most preferably, it is 5 to 35 weight%.

In addition, the cationic conducting organic compound uses a cationic conducting organic compound having a boiling point of 140 ° C. or higher. Examples of the cationic conducting organic compound include carbonate, ketone, sulfone, and amide. , An organic compound having an ether, a polyol, a nitrile, a nitrite, a phosphonate, and an acetate group. In addition, as the anion conducting organic compound, anion conducting organic compounds having a boiling point of 140 ° C. or more are used. Examples of the anion conducting organic compound include sulfoxide, ester, sulfate, phosphate, and phosphate. Compounds having phosphite, imide groups are used.

2 is a flowchart illustrating a method of manufacturing a developing roller for a laser printer according to the present invention.

Referring to Figure 2 in detail, the manufacturing method of the developing roller is an extrusion step (S1), a vulcanization step (S2), a pressing step (S3), a first polishing step (S4), a discharge step (S5), It consists of two polishing processes (S6).

The extrusion process (S1) is made of a tube 30 through a rubber mixed with nitrile rubber (Acrylonitrile Butadiene Rubber, NBR) and epichloro hydrio rubber (ECO). The tube 30 formed in the extrusion step (S1) is applied to sulfur in the rubber in the vulcanization step (S2) is heated to a constant temperature to change the elasticity, the tube 30 vulcanized in the vulcanization step (S2) is press-fitted The shaft is inserted into the tube 30 in step S3.
The constant temperature applied in the vulcanization process according to the present invention refers to a temperature that can be apparent to those skilled in the art, the temperature range may be 100 ℃ to 200 ℃, the constant temperature as a preferred embodiment of the present invention It can be applied at 150 ℃.
The tube 30 inserted into the shaft in the indentation process (S3) is subjected to rough machining in the first polishing process (S4), and separated in the discharge process (S5) by separating the shaft and the tube (30). Inserting the developing roller shaft 10 coated with an adhesive to the tube, and between the tube 30 and the developing roller shaft 10, various surfactants, conductive fillers such as carbon black, metal powder, ion complex type antistatic agent, etc. Is added to the urethane alone or in combination with a conductive low hardness conductive urethane formed. The discharging step (S5) may inject a low hardness silicon of 10 degrees to 100 degrees as a conductive Shore A type, not a urethane-based. The developing roller formed by injecting a low hardness conductive urethane of 10 degrees to 100 degrees into the conductive Shore A type by the discharging step S5 is smoothly processed by the medium grinding process and the finishing process by the second polishing process S6.

The developing roller completed through the process as described above can be made low in hardness to give less toner to give a clear image and can be used for rollers such as high speed printers, color printers.

As described above, preferred embodiments according to the present invention have been described, but the present invention is not limited to the above-described embodiments, and the present invention is not limited to the scope of the present invention as claimed in the following claims. Anyone with knowledge of the present invention will have the technical spirit of the present invention to the extent that various modifications can be made.

The present invention is to inject a low-temperature conductive urethane into the space between the tube and the development roller axis mixed with nitrile rubber (Nryl) and epichloro hydrio rubber (ECO) due to the low hardness The stress on the toner can be reduced, thereby improving the image sharpness.

In addition, since the tube is made of a conductive rubber, a conductive urethane or silicone is cast on the tube, and the surface of the roller is polished to obtain safety of precise dimensions such as roughness, friction coefficient, and outer diameter.

Claims (4)

In a developing roller for a laser printer, in which the hardness of the roller is lowered to increase the sharpness of the image on the toner, A developing roller shaft forming a center of rotation of the developing roller; A tube made of a rubber formed on the outer circumferential surface of the shaft to mix Acrylonitrile Butadiene Rubber (NBR) and Epichloro Hydrio Rubber (ECO); A developing roller for a laser printer, comprising: a conductive urethane layer formed by injecting a conductive urethane having a low hardness of 10 degrees to 100 degrees into an electrically conductive Shore A type between the developing roller shaft and the tube. The method of claim 1, The conductive urethane layer is a development roller for a laser printer, characterized in that the use of a surfactant, carbon black, conductive fillers of metal powders, and ion complex antistatic agents alone or in combination to impart conductivity. The method of claim 1, The conductive urethane layer is a conductive roller for a laser printer, characterized in that the Shore A type can be formed of a low hardness silicon of 10 degrees to 100 degrees. delete

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