JPH04246557A - Rubber roll - Google Patents

Abstract

PURPOSE:To offer a rubber roll which is used as a paper feed roll, a platen roll and others and is easy to control the friction coefficient. CONSTITUTION:The rubber composition of a rubber roll is a blend of butadiene type rubber such as styrene butadiene rubber, nitrile butadiene rubber, etc., and isoprene containing rubber such as isoprene rubber, etc., and the friction coefficient is controlled by the blending ratio of those types of rubber.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber roll used as a platen roll, paper feed roll, etc. in printers, copying machines, etc.

0002

[Prior Art and Problems to be Solved by the Invention] In electronic equipment such as printers, typewriters, facsimile machines, and copying machines, paper feeding is required to convey and process paper and plastic sheets that are recording media. Various rubber rolls such as rolls and platen rolls are used.

[0003] In this case, the friction coefficient of these rubber rolls is important for performance, and conventionally, the friction coefficient has been adjusted by adjusting the hardness of the rubber or by changing the roughness of the surface finish by physically processing the surface. This was done through adjustment.

However, there are problems in that it is difficult to obtain a friction coefficient suitable for the usage conditions by adjusting the rubber hardness, and that physical processing of the surface requires a large number of man-hours.

[0005] The present invention has been made in view of the above circumstances.
To provide a rubber roll whose friction coefficient is easily and reliably adjusted to suit the conditions of use without adjusting the rubber hardness or physically processing the surface.

[0006]

[Means and Effects for Solving the Problems] As a result of intensive studies to achieve the above object, the present inventor has developed a method for forming the surface rubber layer using butadiene rubber such as styrene butadiene rubber, nitrile butadiene rubber, isoprene rubber, butyl rubber, etc. ,
When a rubber having an isoprene group as a chemical structure such as natural rubber is blended, the friction coefficient of the rubber layer can be adjusted arbitrarily by simply changing the blending ratio of the butadiene rubber and the isoprene group-containing rubber, making it possible to adjust the friction coefficient. Therefore, the inventors have discovered that it is not necessarily necessary to adjust the rubber hardness or perform physical processing, and that the coefficient of friction can be easily and reliably controlled to a desired value, leading to the present invention.

Accordingly, the present invention provides a rubber roll having a rubber layer on its surface that comes into contact with objects to be conveyed, wherein the rubber layer is formed of a rubber component that is a mixture of butadiene rubber and a rubber having an isoprene group in its chemical structure. To provide a rubber roll characterized by:

[0008] The present invention will be described in more detail below. The rubber roll according to the present invention is used as a printer, typewriter, facsimile machine, copying machine, other paper feed roll, platen roll, etc. A rubber layer is formed that comes into contact with conveyed objects such as printer paper and plastic sheets.

In this case, in the rubber composition constituting the surface rubber layer, the rubber component is a butadiene rubber containing an isoprene group (-CH2-C(CH3)=CH-CH
2-) A blend with rubber having the chemical structure is used. Examples of butadiene rubber include styrene butadiene rubber (SBR), nitrile butadiene rubber (NBR), etc., and examples of isoprene group-containing rubber include isoprene rubber (IR), butyl rubber (IIR), natural rubber, etc. The friction coefficient of the rubber layer can be adjusted as desired by simply changing the blending ratio of the butadiene rubber and the isoprene group-containing rubber. The blending ratio of the isoprene group-containing rubber to the butadiene rubber is selected as appropriate; the greater the amount of the isoprene group-containing rubber, the higher the friction coefficient becomes. and the isoprene group-containing rubber in a weight ratio of 95:5 to 5:95, particularly 80:20 to 60:40.
It is best to set it within the range of .

[0010] The rubber composition may contain conventional additives such as fillers, vulcanizing agents, vulcanization accelerators, plasticizers, dispersants, processing aids, etc. By blending carbon black with code N356 or lower, a decrease in the coefficient of friction at the initial stage of use can be prevented, and fluctuations in the coefficient of friction of the rubber layer can be prevented as much as possible.

[0011] Here, as the carbon black of ASTM code N356 or lower, 356 to 330 (generally called HAF grade) is particularly preferably used. The blending amount of the carbon black is preferably 50 parts by weight or more, particularly 60 to 80 parts by weight, based on 100 parts by weight of the rubber component when the plasticizer is 5 to 10 parts by weight. If the amount is less than 50 parts by weight, the reduction in the coefficient of friction from the initial stage of use may increase or the impact resistance and abrasion resistance may be poor. Note that if the amount is more than 100 parts by weight, processability tends to deteriorate.

[0012] The rubber roll constructed as described above prevents a decrease in the coefficient of friction at the initial stage of use, and prevents fluctuations in the coefficient of friction from the initial stage of use to after long-term use.
If necessary, the surface rubber layer, preferably the rubber layer obtained from the above rubber composition, can be surface-treated with a chlorinated solvent or treated with ultraviolet irradiation.

In this case, a pseudohalogen compound is suitable as the chlorinated solvent, and the pseudohalogen compound is added in an amount of 0.1 to 5% by weight in a solvent such as acetone, methanol, or ethanol.
, especially those dissolved at a concentration of 0.5 to 1% by weight can be used. The treatment can be carried out by applying this to the rubber layer, but the treatment conditions are 20
Preferably, the heating time is within 1 minute at ~30°C.

On the other hand, for ultraviolet irradiation treatment, it is recommended to use an ultraviolet generating source such as a high-pressure mercury lamp with a lamp power of 80 to 120 W, and to irradiate ultraviolet rays for 30 seconds or more, particularly 30 to 300 seconds.

[0015]

[Examples] The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example 1] A rubber composition having the formulation shown in Table 1 was used, and a platen roll for a dot printer (JI
S-A hardness of 96°) was prepared, and then an actual machine test was conducted using the method described below to evaluate the variation in friction coefficient depending on the number of prints. The results are shown in Table 2 and Figure 1.

As a reference example, Table 2 shows the test results when the above roll was surface treated by applying a 1% by weight acetone solution of a pseudohalogen compound at 25°C for 0.5 seconds.
Also listed in Actual machine test method A string with a weight of 100 g was passed around the platen roll, and evaluation was made from the force (dyne) applied to the load cell when the platen roll was rotated at 5 rpm.

[0018]

[Table 1]

[0019]

[Table 2]

From the results shown in Table 2 and FIG. 1, it was confirmed that the friction coefficient could be controlled simply by changing the blending ratio of SBR and IR.

[0021]

According to the present invention, the coefficient of friction can be easily and reliably controlled, unlike the troublesome methods of adjusting rubber hardness or performing physical processing.

[Brief explanation of the drawing]

FIG. 1 is a graph showing variations in the coefficient of friction depending on the number of prints on rubber rolls with different blending ratios of SBR and IR.

Claims (1)

[Claims] 1. A rubber roll having a rubber layer on its surface that comes into contact with an object to be conveyed, characterized in that the rubber layer is formed of a rubber component that is a mixture of butadiene-based rubber and rubber having an isoprene group as a chemical structure. rubber roll.