JPH0653402B2 - Silicone rubber roll - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention eliminates the adhesiveness peculiar to a silicone rubber roll, and particularly silicone rubber roll, and further reduces the resistance to make it suitable for paper feeding and the like. The present invention relates to a silicone rubber roll.

(Prior Art) As a cleaning roll for cleaning toner offset to a fixing roll and / or a backup roll in an electronic copying machine, a silicone rubber roll is conventionally used because of its moderate elasticity and excellent releasability. This silicone rubber roll is commonly used, but when the surface temperature of this silicone rubber roll deviates from the fixing temperature range, toner adheres and an offset phenomenon occurs. It has the disadvantage that it may involve paper.

For this reason, it is usual to apply an oily coating to the surface of this silicone rubber roll with silicone oil, etc., but this has the disadvantage of increasing the cost due to the increase in the number of processes, and this product also produces dust and the like. To make the roll conductive, a conductive filler such as carbon black is blended to make the roll conductive, but this has a limit to the blending amount in terms of formability. However, there is a drawback in that the amount of electricity supplied is limited.

(Structure of the Invention) The present invention relates to a silicone rubber roll that has solved such disadvantages, and is characterized by being formed by processing a silicone rubber composition containing a vulcanized silicone rubber pulverized product. is there.

That is, as a result of various studies on the method of removing the tackiness of the silicone rubber roll, the present inventors have prepared a mixture of the vulcanized silicone rubber pulverized product as the silicone rubber constituting this silicone rubber, It was found that the silicone rubber roll can be made non-adhesive, eliminating the need for coating with silicone oil or the like, and the silicone rubber molded product to which this vulcanized silicone rubber crushed product has been added has No extreme decline,
In addition, it was confirmed that a silicone rubber roll with stable quality can be obtained because the amount of the conductivity-imparting agent added to give a resistance value equivalent to that of the conventional product can be reduced. Types of crushed rubber products,
The present invention has been completed by conducting research on particle size, addition amount, and the like.

The silicone rubber for producing the silicone rubber roll of the present invention may be a conventionally known one, and therefore, one having a general formula And R is an alkyl group such as a methyl group, an ethyl group, a propyl group, an alkenyl group such as a vinyl group or an allyl group, an aryl group such as a phenyl group, or a hydrogen atom bonded to a carbon atom of these groups. A chloromethyl group in which part or all of which is substituted with a halogen atom, a cyano group, etc.,
The same or different unsubstituted or substituted monovalent hydrocarbon group such as 3,3,3-trifluoropropyl group, cyanomethyl group, etc., n is a positive number of 1.9 to 2.05, preferably this The organopolysiloxane in which 50 mol% or more of R is a methyl group is assumed to have a viscosity of 500 to 1,000,000 cS, preferably 1,000 to 500,000 cS. Good.

Although the silicone rubber containing the organopolysiloxane as a main component has an excellent insulating property, the silicone rubber roll of the present invention is mainly used as a fixing roll or a backup roll for an electronic copying machine. Therefore, it is preferable to add carbon black as a conductivity-imparting agent to make it conductive. This carbon black may be commercially available, including acetylene black, ketjen black, harness black,
Thermal black and the like are exemplified, but the amount to be added may be determined according to the conductive property required for the composition of the present application, and this conductive silicone rubber composition has an electric resistance of 3 to 1 KΩ-cm. Therefore, the blending amount of carbon black may be 5 to 50% by weight.

The vulcanized silicone rubber crushed product added to the composition of the present invention is not particularly limited as long as it is obtained by pulverizing vulcanized silicone rubber, and it is heated in the presence of a peroxide catalyst. It may be either sulfurized, obtained by a heat addition reaction in the presence of a platinum-based catalyst, or even cured at room temperature with moisture in air,
It is preferable to use a pulverized product obtained by vulcanizing with a peroxide catalyst. Since this vulcanized silicone rubber is usually a molded product, it may be a cut piece during the production of the molded product, and it is industrially useful to use a recovered product such as this cut piece. However, when the particle size is 0.05 mm or less, the paper is entangled when it is fed, and when the particle size is 3.0 mm or more, the compatibility with silicone rubber,
Since the kneading property becomes poor and the physical properties such as tensile strength, tear strength, and elongation of the rubber roll obtained by mixing the same are deteriorated, 0.05 to 3.0 mm, preferably 0.05 to
It is recommended that it be 1.0 mm. The addition amount of the vulcanized silicone rubber pulverized product may be determined depending on the hardness expected for the silicone rubber roll of the present invention.
This is not effective when the amount is 10 parts or less relative to 100 parts by weight of the silicone rubber base material, and when the amount is 200 parts by weight or more, the kneading property is deteriorated and the physical properties of the obtained silicone rubber roll are deteriorated. The amount may be in the range of up to 200 parts by weight, and within this range, the physical properties of the silicone rubber base material are not significantly impaired. The silicone rubber hardness of the vulcanized material is preferably equal to or higher than the hardness of the silicone rubber material. Specifically, the hardness of the pulverized product is 40 to 70 degrees, preferably 50 to 60 degrees, and the hardness of the material rubber is 30-60 degrees, preferably 30
It is desirable that the hardness difference is in the range of 10 to 30 degrees by setting the hardness to -40 degrees.

In the present invention, the silicone roll is made electrically conductive by blending a predetermined amount of carbon black with the above-mentioned silicone rubber material, if necessary, and then adding the above-mentioned vulcanized pulverized silicone rubber product and thoroughly kneading. To produce a silicone rubber composition, and then press-mold it on a shaft coated with a primer, or roll steam-mold it into a silicone rubber molded body, and then polish it with a polishing machine. Good. The silicone rubber roll obtained in this way is a mixture of vulcanized crushed silicone rubber in the raw material silicone rubber, and the exudation of the silicone oligomer in the pulverized parts is smaller than that of the silicone rubber-based oligomer. ,
Alternatively, the crushed product parts are dispersedly arranged in the silicone rubber-based material, and since the crushed product parts have poor adhesion, the tackiness that a silicone rubber roll of this type has in the past is lost, and therefore the present invention Press the silicone rubber roll with a constant load (24 hours x 1 kg, room temperature),
Then, when the load is released and the roll is picked up, the paper does not stick to it, so it is an advantage that the paper does not get caught when the paper is fed when it is used as a fixing roll or backup roll of an electronic copying machine. In addition to being provided, the amount of carbon black added for imparting conductivity can be reduced, so that color fading on paper is reduced, and the convenience that a roll with stable quality can be obtained is also provided. Given.

Next, examples of the present invention will be given. Parts in the examples are parts by weight.

Example To 100 parts of silicone rubber compound KE951U [trade name of Shin-Etsu Chemical Co., Ltd.], vulcanizing agent C-8 [trade name of the same company] 4.0 and 60 parts of acetylene black were added and mixed uniformly to conduct electricity. -Based silicone rubber material A is made, and then the above-mentioned silicone rubber compound KE9
51U A silicone rubber composition made by mixing 100 parts of vulcanizing agent C-8 (previously described) with 180C at 200 kg
1 mm thick flat plate obtained by vulcanizing for 10 minutes at a pressure of 1 / cm ² and crushed by a roll shear crusher to obtain a vulcanized silicone rubber crushed product having an average particle size of 0.35 mm (hereinafter abbreviated as SWP). Was added in an amount shown in Table 1 to prepare a silicone rubber composition.

Next, this silicone rubber composition was press-molded on a stainless steel / SUS304 shaft having a diameter of 10 mm and a length of 400 mm to form a rubber roll, which was ground with a polishing machine to obtain a black rubber roll having an outer diameter of 30 mm and a length of 360 mm. When the physical properties were examined and the physical properties were as shown in Table 1, none of them had tackiness and no paper was entangled when they were used as a fixing roll.

However, for comparison, the physical properties of the silicone rubber roll obtained by treating in the same manner as above except that the vulcanized silicone rubber pulverized product described above is not added are as shown in Table 1, and the physical properties are shown in Table 1. Therefore, when this was used as a fixing roll, paper was often caught.

Claims (3)

[Claims] 1. A silicone rubber roll formed by molding a silicone rubber composition containing a vulcanized silicone rubber pulverized product. 2. A vulcanized silicone rubber ground product has a particle size of 0.05.
The silicone rubber roll according to claim 1, which has a diameter of about 3.0 mm. 3. The silicone rubber roll according to claim 1, wherein the compounded amount of the vulcanized vulcanized silicone rubber is 10 to 200 parts by weight based on 100 parts by weight of the silicone rubber.