JPH0581425B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention provides a method for manufacturing a silicone rubber roller,
In particular, silicone rubber and core metal adhere firmly even without the use of adhesion aids such as primers.
The present invention relates to a method for easily and continuously producing silicone rubber rolls at low cost by extrusion molding. (Conventional technology) Silicone rubber rollers have been widely used for platen rollers, reading rollers, fusing rollers, etc. used in facsimile machines, copiers, various printers, etc. due to their excellent heat resistance and quality stability. However, in order to improve the adhesion between the core metal and the silicone rubber, this silicone rubber roller first processes the surface of the core metal made of stainless steel, aluminum, nickel-plated iron, etc. with sandpaper, shot blasting, sandblasting, etc. After roughening the surface, an adhesion aid called a primer is applied with a brush or spray, and then compression molding or injection molding of silicone rubber is performed using a special mold. It is being However, in order to roughen only the required bonding surface of this core metal, masking or batch processing of one to several pieces is required, which is time-consuming, inefficient, and costly. Also, when applying the primer, it is difficult to maintain stable quality because the primer is sensitive to moisture and loses its adhesive strength when hydrolyzed, and the rubber does not harden quickly after application. There is a problem in that poor adhesion occurs. In addition, since the silicone rubber molding process is performed using a batch method such as compression molding or injection molding using a special mold, the production efficiency is low and the cost is high. death,
In terms of quality, due to the difference in the flow of rubber at the joint between the top and bottom of the mold, the hardness of the rubber in this part is higher than in other parts, and the rubber is extremely prone to chipping due to overcure. There was a problem. (Structure of the Invention) The present invention relates to a method for manufacturing a silicone rubber roller that solves the above problems.
This is a process in which an addition reaction type organosiloxane composition consisting of a vinyl group-containing organopolysiloxane, an organohydrodiene polysiloxane, and a platinum-based catalyst is continuously coextruded onto a core metal using an extruder and cured by heating. It is characterized by: That is, as a result of various studies conducted by the present inventors on methods for easily and continuously producing silicone rubber rollers, the organosiloxane composition used here was selected from vinyl group-containing organopolysiloxane, organohydrodiene polyester, etc. If the so-called addition reaction type is made of siloxane and a platinum-based catalyst, the silicone rubber obtained by heating and curing this organosiloxane composition and the core metal will be strong without using an adhesion aid such as a primer. In addition, molding using this organosiloxane composition can be done by continuously extruding this uncured organosiloxane composition onto a core metal using an extruder and then heating and curing it, making it easy to compress. The present invention was completed after discovering that the production capacity can be increased several times compared to molding or injection molding, and that a product with extremely stable quality without any local change in physical properties of rubber can be obtained. This will be explained in more detail below. The organopolysiloxane composition used in the method of the present invention consists of 1) a vinyl group-containing organopolysiloxane, 2) an organohydrodiene polysiloxane, and 3) a platinum-based catalyst. The vinyl group in the siloxane and the hydrogen atom (≡SiH) bonded to the silicon atom contained in the organohydrodiene polysiloxane as the second component are
Reacted in the presence of a platinum-based catalyst as a component≡
It is a so-called addition reaction type in which Si(CH=CH ₂ )+≡SiH→≡Si−CH ₂ −CH ₂ . The vinyl group-containing organopolysiloxane as the first component may contain 0.05 to 3.0 mol% of vinyl groups, and this vinyl group may be located anywhere in the molecule, but is preferably expressed by the following formula:

[Chemical formula], R ¹ is a methyl group, an ethyl group, a vinyl group,
It is preferable to use the same or different monovalent hydrocarbon groups selected from phenyl groups, where l is an integer of 100 to 10,000, and both ends of the molecular chain are blocked with diorganovinylsilyl groups. In addition, the organohydrodiene polysiloxane as the second component has the formula

[Chemical formula] and contains in the molecule at least two silicon-bonded hydrogen atoms (≡SiH) that undergo an addition reaction with the vinyl group in the vinyl group-containing organopolysiloxane as the first component. ^R2 may be a hydrogen atom, an atom selected from a methyl group, an ethyl group, a phenyl group, or a monovalent hydrocarbon group, and m may be an integer from 10 to 1000. The amount of this organohydrodiene polysiloxane is based on the above-mentioned vinyl group-containing organopolysiloxane as the first component.
If the amount is less than 0.5 parts by weight, the composition will be difficult to cure even when heated, and the silicone rubber obtained will not have the desired physical properties; if the amount is more than 30 parts by weight, the silicone rubber obtained by heating will be hard to cure. Since the rubber becomes very brittle, the amount is preferably in the range of 0.5 to 30 parts by weight. Next, the platinum-based catalyst as the third component is platinum black, platinum such as platinum sponge, platinum chloride, chloroplatinic acid, a reaction product of chloroplatinic acid and a monohydric alcohol, a reaction product of chloroplatinic acid and an olefin, or vinyl. The platinum compound may be selected from platinum compounds such as complexes with siloxanes, but the amount may be a catalytic amount, so this is usually 100 parts by weight of the vinyl group-containing organopolysiloxane as the first component. It may be within the range of 50-2000ppm. In addition, since the silicone rubber obtained by heat curing this organosiloxane composition has excellent mechanical strength, a reinforcing filler is often added.
Examples of this include dry-processed silica, wet-processed silica, diatomaceous earth, or those treated with hydrophobic treatment using organosilane, organosiloxane, etc., but if the amount is less than 10 parts by weight, the rubber roller will not work. 120 because the rubber strength could not be obtained when
If the amount exceeds 1 part by weight, the silicone rubber will lose its rubber elasticity, so it is preferably in the range of 10 to 120 parts by weight. Regarding silicone rubber rolls, conductive silicone rubber rolls made of conductive silicone rubber are also required, but in this case, it is sufficient to add carbon black such as acetylene black, furnace black, butthorn black, etc. If the amount added is less than 2 parts by weight based on 100 parts by weight of the vinyl group-containing organopolysiloxane as the first component, conductivity cannot be obtained, and if it is more than 60 parts by weight, the silicone rubber will lose its rubber elasticity. The amount is preferably in the range of 2 to 60 parts by weight, and according to this, it is possible to obtain a silicone rubber that exhibits good conductivity without curing failure even when cured using an organic peroxide or the like. I can do it. In order to adjust the addition reaction rate of this organosiloxane composition, it is optional to add an addition reaction rate retardant such as an organic nitrogen compound, an alkyne compound, or a tin compound. A silicone rubber roller can be manufactured from this organosiloxane composition by continuously extruding it onto a core metal using an extruder, molding it, and then heating and curing it. A conventionally known material such as aluminum or nickel plated iron may be used. However, the organosiloxane composition used in this core metal is of the addition reaction type mentioned above, and the cured silicone rubber adheres strongly to the core metal, but this adhesive surface must be shot blasted beforehand. It may be roughened by sandblasting or the like, or it may be coated with a primer or the like. The organopolysiloxane composition after extrusion molding can be cured by heating, but this can be done using an ordinary oven, an infrared heated conveyor drying oven, etc. Since it cures at low temperature and in a short time, it is possible to easily and inexpensively obtain the desired silicone rubber roller. Next, examples of the present invention will be given, and parts in the examples indicate parts by weight. Example 1 100 parts of addition reaction type silicone rubber compound KE153u [trade name manufactured by Shin-Etsu Chemical Co., Ltd.] was cured for addition reaction on an area of 25 x 25 mm in the center of a stainless metal plate with width of 25 mm x length of 60 mm. Agent/C-153A [Shin-Etsu Chemical Co., Ltd. trade name] 2.5 parts, platinum catalyst/Cat-
PL-2 [trade name manufactured by Shin-Etsu Chemical Co., Ltd.] 5 pieces of rubber material to which 0.03 part of rubber material was extruded into 3 mm thick sheets using an extruder were placed in an oven at 200°C for 30 minutes. Heat to harden, then
When a peel test was conducted in accordance with JIS K6301, this product showed the adhesive strength shown below, even though the metal plate was not primed.

[Table] Example 2 Addition reaction type silicone rubber compound KE941u [Shin-Etsu Chemical Co., Ltd.] using the rubber material in Example 1
Co., Ltd. product name] 100 parts, curing agent for addition reaction, C-
Example 1: 2.0 parts of 153A (mentioned above), 0.05 parts of platinum catalyst Cat-PL-2 [mentioned above] and 10 parts of carbon black Ketchen Black [trade name manufactured by Lion Akzo Co., Ltd.] were added. Five samples were prepared in the same manner as above, and the adhesive strength with these metal plates was examined. All of them were cut at the rubber layer, and the adhesive strength results were as shown in Table 2. Ta.

[Table] In addition, this rubber material was continuously extruded from an extruder together with a stainless steel core material for rubber rolls with an outer diameter of 10 mm and a length of 300 mm to make a rubber roller with a diameter of 18 mm, and this was placed in an oven at 200°C for 30 minutes. After heating and curing, the rubber hardness as a roller was measured using a JIS A-type rubber hardness tester at 20 arbitrary points per piece, n = 50, and the rubber hardness was as shown in Table 3 below. The results showed very little variation, and the adhesive properties of this product were all good.

【table】

Claims (1)

[Claims] 1. An addition reaction type organosiloxane composition consisting of a vinyl group-containing organopolysiloxane, an organohydrodiene polysiloxane, and a platinum-based catalyst is continuously coextruded onto a core metal using an extruder and cured by heating. A method for manufacturing a silicone rubber roller.