JPS60260308A - Manufacture of elastomer sheet - Google Patents

Abstract

PURPOSE:To mold an elastomer sheet with a mirror surface, by injecting a silicone rubber that will set at normal temperatures or will thermally set onto the inner surface of a cylindrical mold followed by setting, and then injecting a liquid elastomer onto the inner surface followed by setting under the influence of a centrifugal force. CONSTITUTION:While a cylindrica mold is rotated, a silicone rubber that would not react with the mold, is free from a solvent and will set at normal temperatures or will thermally set is injected onto the inner surface followed by setting to form a molding surface. The cylindrical mold 9 is attached to a rotating shaft end of a centrifugal molding machine that is housed in a heating jacket in the shape of a box and will be rotated by a motor 7. The ouside of the heating jacket is covered with an insulating layer 5, the heating jacket has a heater 10, and the opening thereof can be closed by a lid 6. An elastomer such as a liquid urethane in a prescribed amount is injected onto the set layer of the silicone rubber, the mold is heated and rotated, and the molded part is removed, is cut longitudinally, and is treated to be hardened by using a planar member to obtain planar sheet body.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing an elastomer sheet used for cleaning blades of electrophotographic copying machines and the like.

<Prior art and its problems> Electronic copying machines, especially so-called P copying machines that use plain paper as recording paper
Cleaning the photoreceptor is an important issue in PC copying machines, and one cleaning method involves bringing an elastic rubber blade such as urethane rubber or neoprene rubber into contact with the electrophotographic photoreceptor to remove residual toner on the photoreceptor. A so-called cleaning blade method for cleaning has been put into practical use.

Additionally, since this method brings the blade into physical contact with the surface of the moving photoreceptor, the surface roughness accuracy (edge accuracy) of the end surface of the blade that comes into contact with the photoreceptor becomes a serious problem. is defined as 10- or less, and 1
If it is less than 0, copying defects such as V ghost images or thread lines appearing on the recording paper will occur.

Conventionally, a fluorine-based, silicone-based, or wax-based solvent-type or emulsion-type mold release agent is used when molding a rubber sheet for the blade described in (1) above.

However, this mold release agent may be transferred to the surface of the blade rubber sheet and contaminate the sheet. Furthermore, there is a problem that the mold release agent is not uniformly coated on the mold. There are types such as Teflon coating that are directly coated on the mold, but since the Teflon coating surface is matte and has a rough surface, the sheet formed by applying it will also have a rough surface. For this reason, the sheet surface covered with the Teflon coating could not be used as a cleaning ridge for the blade. Additionally, since the Teflon coating is bonded to the mold, if the coating is damaged, it requires a lot of time to recoat.

As a prior art, there is Japanese Patent Application Laid-Open No. 58-132775, which uses a solvent type silicone comb as a mold release agent, and as mentioned above, there is a problem of contamination due to transfer.

<Object of the Invention> The object of the present invention is to provide a method for manufacturing an elastomer sheet that can finish both sides of the sheet to a mirror finish without contaminating the cleaning blade sheet by using a solvent-free mold release agent. That's what we're trying to offer.

<Brief Description of the Invention> The present invention involves forming a mold surface by injecting and curing solvent-free room temperature or thermosetting silicone rubber that does not react with the mold onto the inner surface while rotating a cylindrical mold. To provide a method for manufacturing an elastomer sheet, which comprises injecting a liquid elastomer into the sheet, centrifugally molding the sheet until it loses its fluidity, and cutting the obtained cylindrical molded object into a flat plate to complete curing. .

<Specific structure of the invention> Preferred embodiments of the present invention will be described in detail below.

When carrying out the method of the present invention, it is preferable to use a centrifugal molding machine as shown in FIG.

This centrifugal molding machine is covered with a heat insulating layer 5 on the outside, has a heater 10 inside, has a box-shaped heating jacket whose opening can be closed with a lid 6, and has a motor 7 inside the heating jacket. One end of a rotary shaft 8 provided to rotate is made to protrude, and a cylindrical mold 9 is attached to the end of the rotary shaft. First, a release agent is placed in this cylindrical mold 9 to form a release film, and then an elastomer for the sheet is placed to form the sheet.

The mold release agent used in the present invention is a solvent-free liquid room-temperature or thermosetting silicone rubber that does not react with the mold. This reduces the bonding force between the mold release layer and the mold, so that even if the mold release layer is damaged, it can be easily regenerated.

Further, as the elastomer supplied onto the silicone rubber mold release film, there are liquid rubbers and the like, and liquid urethane is most preferable. If the mold release agent and elastomer are selected in this manner, the bonding force between the elastomer sheet and the mold release layer after molding is smaller than the bonding force between the mold release layer and the mold, so that only the elastomer sheet can be peeled off.

The temperature and rotation speed of the mold are determined depending on the mold release agent and sheet elastomer used.

<Example> A cylindrical mold with an inner diameter of 500 am and a length of 300+sm was
Two-component curing silicone rubber (Shin-Etsu Chemical Co., Ltd., 1204A, B) was mixed at a ratio of 1:7 and injected into a cylindrical mold while rotating with an Orpm.
The product was centrifugally molded at room temperature for 0 minutes, then held in an atmosphere at 100°C for 10 to 20 minutes, and cured in a cylindrical mold to form a cured silicone rubber layer.

Next, the cylindrical mold was left in an atmosphere of 90°C and heated to 1100°C.
While rotating with an orp, place it on the cured layer of silicone rubber.
) Liquid urethane 600 blended to 1g700
g was injected and heated and rotated. After the fluidity of the urethane disappeared, the rotation was stopped, and only the urethane sheet was removed from the cylindrical mold. This cylindrical urethane molded body was cut in the axial direction, flattened, and placed on a flat surface plate at 110°C.
The curing was completed by holding for 0 hours. The thickness of the sheet obtained was 4.2 am.

After that, the urethane molded sheet was cut to a width of 30III11, and the cut ridges were examined.
The surface roughness of each ridgeline in c and d is Rwax and is 5IjJl
It was below.

Furthermore, although the above urethane rubber sheet molding was repeated 20 times, no peeling occurred between the cured silicone rubber layer and the cylindrical mold when the molded sheet was released. Thereafter, a test was conducted in which the silicone rubber was peeled off from the cylindrical mold, and it was found that the cured silicone rubber layer could be easily removed from the mold.

The sheet produced by the method of the present invention has the following uses.

(1) Cleaning blade for electrophotographic copying machine As shown in FIG. 2, the sheet obtained by the method of the present invention can be cut and used as a cleaning blade for the photosensitive drum 4. Since this blade has an Rtiax of 5 or less on both the surface 1 that does not come into contact with the mold release agent layer and the surface 2 that does come into contact with the mold release agent layer during molding, all of these ridgelines can be used.

(2) Elastic glass In the sheet molding method according to the present invention, both sides of the sheet can be mirror-finished, so by selecting the raw material for the sheet, it is possible to reduce the haze and produce elastic glass.

(3) By selecting the raw material for the elastic mirror molding sheet, the elastic mirror can be manufactured with reduced haze.

(4) It can be used as a cleaning material for parts of precision optical machines that do not like surface stains, such as the copy glass of scraper PPC and the mounting glass of universal projectors.

(5) Mirror sheet It is possible to produce a mirror sheet other than centrifugally molded by using a centrifugally molded mirror silicone rubber sheet on the flat press mold surface and transfer mold surface.

<Effects of the Invention> In the present invention, since a solvent-free silicone rubber is used as the mold release agent, the sheet surface can be made into a mirror surface without transfer of the mold release agent, which is preferable in terms of safety and health. Moreover, since the bonding force between the mold release agent layer and the molded sheet can be made smaller than the bonding force between the mold release agent layer and the mold, only the molded sheet can be easily peeled off. In addition, the bonding force between the mold release agent layer and the mold is not adhesive, but is held only by adhesion, so it is small and can be easily peeled off, making it easy to recoat when damaged.

The above-mentioned mold release agent layer has a mirror surface, and by injecting an elastomer onto it, the elastomer can be uniformly diffused during molding, and the sheet can be formed with a uniform thickness and fewer trapped air bubbles. A highly transparent sheet with low haze can be obtained.

[Brief explanation of the drawing]

FIG. 3 is a schematic cross-sectional view showing a state in which the blade shown in the figure is applied to an electrophotographic copying machine, and FIG. 3 is a partial cross-sectional view of a centrifugal molding machine used to carry out the method of the present invention. Explanation of symbols 1... Non-mold surface during sheet molding, 2... Mold surface during sheet molding, 3... Cut surface, 4... Photosensitive drum, 5
...Heat insulation layer, 6...Lid, 7...Motor, 8...
Rotating shaft, 9...Cylindrical mold, 10...Heater procedure amendment (salmon) Shosodoya July 7, 2015 Manabu Shiga, Commissioner of the Patent Office 1, Indication of the case 1982 Patent Application No. 117705 No. 2, Name of the invention Method for manufacturing elastomer sheets 3, Person making the amendment Representative frame Column 6, Contents of the amendment As shown in the attached sheet 6, Contents of the amendment (1) Page 2, line 8 of the specification "Surface roughness" is corrected to "edge line roughness." (2) On the 2nd page, line 10, the word ``Daru Toki'' is corrected to ``Naru Toru Toki ni''. (3) On page 3, lines 11-12, “The above…
There is. ' shall be corrected as follows. Since it is a type that adheres to the mold, it has the disadvantage that, like Teflon coating, it takes time to recoat if it gets scratched. (4) "Figure 3" on page 4, line 11 is corrected to "Figure 1." (5) Change “l to 7” on page 5, line 20 to “1 to 1”
I am corrected. (6) "rHs700" on page 6, line 7 of the same page, rHs7
0”J. (7) Change rsoogJ on page 6, line 8 to r2400.
Correct it to gJ. (8) Change “Figure 1” on page 6, line 16 of the same page to “Figure 2 J.
I am corrected. (9) ``Delete surface j'' on page 6, line 17. (lO) Change ``Figure 2'' on page 7, line 8 to ``Figure 3.''
I am corrected. (11) On page 7, line 12, "Surface 2" is corrected to "Surface roughness of surface 2." (12) “Those ridgelines” on page 7, line 13,
``What is the ridge line obtained by cutting those surfaces?'' (13) “Figure 1 is...
It is... ' shall be corrected as follows. "Figure 1 is a partial sectional view of a centrifugal molding machine used to carry out the method of the present invention, Figure 2 is a perspective view of a blade obtained by cutting a sheet molded by the method of the present invention, and Figure 3 is a 2
FIG. 2 is a diagrammatic cross-sectional view showing a state in which the blade shown in the figure is applied to an electrophotographic copying machine. ”

Claims (1)

[Claims] While rotating the cylindrical mold, a solvent-free room-temperature or thermosetting silicone rubber that does not react with the mold is injected into the inner surface and cured to form a mold surface, and a liquid elastomer is injected into the mold surface until it loses its fluidity. A method for producing an elastomer sheet, which comprises performing centrifugal molding, cutting the obtained cylindrical molded product into flat plates, and completing curing.