JPH0430607Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] The present invention relates to a pressure roller.

[Prior Art] Conventionally, a heat fixing method has been adopted as an image fixing means in electrophotographic copying machines and the like. A thermal fixing device that fixes an image is composed of a heat fixing roller (heat roller) that fixes the image, and a pressure roller (press roller) that rotates while being in contact with this roller on its circumferential surface. . The pressure roller is required to have excellent heat resistance, flexibility, and mold release properties. Thus, when the object to be fixed passes between the pressure roller and the heat fixing roller, a predetermined image is fixed under a constant load.

[Problems to be solved by the invention] The surface coating layer of the pressure roller is formed of a silicone rubber layer, silicone oil is applied as an offset prevention liquid to one of the pressure roller or the heat fixing roller, and both are coated with silicone oil as an anti-offset liquid. It is designed to improve the releasability of the fixing object from the roller.

However, even if an anti-offset liquid is used, as the number of sheets printed increases, the surface releasability of the pressure roller deteriorates. As a result, there was a problem in that toner adhered to the surface of the pressure roller and accidents occurred due to entanglement of the copy paper as the fixing object.

[Means for solving the problem] The present invention provides a roller core with a surface coating layer made of a silicone rubber layer containing crosslinked silicone resin fine powder with a particle size of 10 μm or less and a methyl group on the particle surface. This is a pressure roller provided on gold.

Here, the silicone resin fine powder may be hardened in fine powder form, or it may be hardened silicone resin and then ground into fine powder.

The particle size of the silicone resin fine powder is 10 μm or less, and preferably 5 μm or less in order to obtain a higher effect. If it exceeds 10 μm, the dispersibility in the silicone rubber layer will deteriorate, and the surface coating layer will not be able to fully exhibit its mold release effect.

The proportion of the silicone resin fine powder to the silicone rubber layer is in the range of 1 to 50 parts by weight, more preferably 1 to 30 parts by weight, based on 100 parts by weight of the silicone rubber layer. If it exceeds 50 parts by weight, the surface coating layer becomes hard and loses flexibility, making it unsuitable as a pressure roller. If the amount is less than 1 part by weight, the surface coating layer will have poor releasability, making it unsuitable as a pressure roller.

As the material for the silicone rubber layer, it is desirable to use room temperature curable silicone rubber (RTV), addition reaction silicone rubber (LTV), high temperature curable silicone rubber (HTV), or the like.

[Function] According to the pressure roller of the present invention, the surface coating layer provided on the roller core metal is formed of a silicone rubber layer containing the above-mentioned silicone resin fine powder, so that methyl on the particle surface is The surface energy can be lowered by the group, and the releasability from the toner can be significantly improved.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of an embodiment of the present invention, and FIG. 2 is a sectional view taken along the - line of the embodiment. A silicone rubber composition having the following composition was applied to the circumferential surface of a roller core bar 1 with a diameter of 50 mm, press vulcanized at a temperature of 150°C for 3 minutes, and then polished to obtain a shape as shown in the figure. A pressure roller 10 having a diameter of 60 mm and having a predetermined surface coating layer 2 was obtained. When the obtained pressure roller 10 was used to make copies using the heat fixing device of an electrophotographic copying machine NP500RE (product name of Canon Inc.), even after copying 100,000 sheets of copy paper, the copy paper became tangled. No accidents occurred due to this.

Parts by weight Silicone rubber 100 (TSE221-4u, Toshiba Silicone Corporation trade name) Silicone resin fine powder 25 (XC-99-501, Toshiba Silicone Corporation trade name) Crosslinking agent 1 (Dicumyl peroxide) Coloring agent 0.5 (Red Garla) [Comparative Example] Next, a comparative example conducted for comparison with the above-mentioned example will be described.

A pressure roller was made using the silicone rubber composition shown below in the same manner as in the example, and when a copying test was conducted using this roller in a similar heat fixing device, approximately 40,000 sheets of copy paper were copied. However, an accident occurred where copy paper got tangled in the pressure roller, making it unusable.

Parts by weight Silicone rubber 100 (TES221-4u, Toshiba Silicone Co., Ltd. trade name) Crosslinking agent 1 (Dicumyl peroxide) Coloring agent 0.5 (Red iron oxide) [Effects of the invention] As explained above, the pressurization according to the invention According to the roller, the releasing effect of the surface coating layer on the roller core metal is significantly improved, and it is possible to prevent accidents caused by copy paper getting tangled in the heat fixing device.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an embodiment of the present invention, and FIG. 2 is a sectional view taken along the - line of the embodiment. DESCRIPTION OF SYMBOLS 1...Roller core metal, 3...Surface coating layer, 10...
...Pressure roller.

Claims (1)

[Scope of utility model registration request] A pressure roller comprising a surface coating layer made of a silicone rubber layer containing fine crosslinked silicone resin powder having a particle size of 10 μm or less and having a methyl group on the particle surface, on a roller core metal. .