JPS6272734A - Antiblocking rubber composition - Google Patents

Abstract

PURPOSE:To obtain a rubber composition capable of giving a rubber product which can be used or stored for a long period in contact with a metal or plastic, etc., without causing the blocking to the metal, etc., by adding a specific bisamide to a rubber component. CONSTITUTION:The objective antiblocking rubber composition can be produced by compounding (A) 100pts.(wt.) of a rubber component such as NBR, SBR, etc., with (B) 0.1-50pts., preferably 0.5-20pts. of a bisamide of formula (n is >=1 and preferably <=3; R and R' are >=10C alkyl), e.g. erucic acid ethylene bisamide, stearic acid ethylene bisamide, etc., and optionally (C) a filler such as carbon black, etc., a vulcanizing agent, a vulcanization accelerator, an antioxidant, etc. The composition is most suitable as a material for the production of a rubber product to be used in contact with metal or plastic, e.g. solenoid valve, diaphragm, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to an anti-sticking rubber composition, and more particularly to a rubber composition capable of producing rubber products that do not stick to metals or plastics.

[Technical background of the invention]

For example, a solenoid valve as shown in FIG. 1 includes a valve 3 that is negatively biased toward the valve seat 2 by a spring
It has an electromagnetic coil 4 for moving in the opposite direction. The gas and fluid conduit 5 is opened and closed by the vertical movement of the valve 3. That is, when the valve 1 is pressed against the valve seat 2 by the negative force of the spring 1, the conduction path 5 is in a closed state, and current flows through the electromagnetic coil 4 to resist the negative force of the spring 1. The structure is such that when the valve 3 is separated from the valve seat 2, the conduction path 5 is opened.

The valve 3 as described above consists of a metal valve body 30 that is attracted to the electromagnetic coil 4 and a rubber part 31 that covers the valve body 30. The rubber part 31 comes into contact with the valve seat 2, and the valve body 3 and the valve seat 2 to ensure airtightness.

In this way, parts such as the valve seat 2 and the rubber part 31 of the valve 3 that come into contact with each other can become stuck due to long-term use or storage, and solenoid valves, etc. A situation may occur where the valve mechanism does not operate.

The above-mentioned sticking of metal and rubber parts is not limited to the above-mentioned solenoid valve, but also occurs in mechanisms in which rubber products are combined with metal parts, such as umbrella check valves, needle valves, and diaphragms, due to malfunction of the mechanism. It is known that this is an important cause of such problems. When such adhesion occurs between the metal and the rubber article, if the rubber article and the metal are forcibly separated, substances such as bloom remain, which impairs the sealing performance of the valve mechanism and causes leakage. There is.

[Summary of the invention]

The present invention was made in view of the above points, and an object of the present invention is to provide a rubber composition that does not adhere to metals or plastics.

Therefore, the anti-sticking rubber composition according to the present invention is characterized in that 0.1 to 50 parts by weight of bisamide of the following general formula is added to 100 parts by weight of the rubber component.

RCONII (CH2)n HNOCR' (in the above formula, n is an integer of 1 or more, and R and R'' represent an alkyl group having 10 or more carbon atoms).

The anti-sticking rubber composition according to the present invention has the advantage that it does not stick to metals or plastics, and is therefore ideal as a material for manufacturing rubber products such as solenoid valves and diaphragms that bring rubber into contact with metals or plastics. There is an advantage to having one.

[Detailed description of the invention]

The anti-sticking rubber composition according to the present invention is prepared by adding 0.1 to 50 parts by weight of a bisamide having the following general formula to 100 ffi parts of the rubber component as described above.

RCON H(CH2) n HN OCR' In the above general formula, R and R' represent an alkyl group having 10 or more carbon atoms, and n represents an integer of 1 or more. As mentioned above, such bisamides have a structure that has higher alkyl groups with a large number of carbon atoms, so a concentration gradient is formed in which the concentration of bisamides decreases from the surface of the rubber product toward the inside. It has the advantage of exhibiting good anti-sticking properties in small amounts. Therefore, the above R and R
The number of carbon atoms must be 10 or more as described above.

The aforementioned n is 1 or more, but preferably n is 3 or less. This is because if n exceeds 3, it is currently difficult to obtain and it is difficult to expect industrial mass production.

Examples include one or more of tyrene bisamide and the like.

The rubber component to which bisamide as described above is added is not fundamentally limited in the present invention. For example, NBR,, SBR,, CR,, lR111R, BR,
NR, ethylene propylene rubber, epichlorohydrin rubber, fluorine rubber, chlorosulfonated polyethylene, acrylic rubber, chlorinated polyethylene, urethane rubber, ethylene-vinyl acetate copolymer, silicone rubber, and mixtures of two or more of these can.

The above-mentioned bisamide is added to such a rubber component, and the amount added is preferably 0.1 to 50 parts by weight. If the amount is less than 0.1 part by weight, the addition effect will not be exhibited, while if it exceeds 50 parts by weight, not only will the anti-sticking property not increase, but there will be problems in roll kneading processability.
Also, welt marks are produced on the surface of manufactured rubber products. For example, when used in a solenoid valve, the sealing performance will be impaired.

Most preferably it is 0.5 to 20 parts by weight.

Such a rubber composition may optionally contain various other substances normally added to rubber, such as a filler such as carbon black, a vulcanizing agent, a vulcanization accelerator, and an anti-aging agent. Needless to say, it is.

Rubber products manufactured from the rubber compositions described above have anti-sticking properties against various objects. Examples of objects to be prevented from sticking include metals such as Fe, Ni-plated Fe, Cu, Al1, and brass, as well as polycarbonate, polyester, and acrylic resin.

Example I NBR100M parts SRF carbon black 50 parts by weight (Geast S, manufactured by Tokai Carbon Co., Ltd.) Stearic acid 5 parts by weight Sulfur
0.5 parts by weight TT (vulcanization accelerator) 1.5 parts by weight CZ (vulcanization accelerator) 1.5 parts by weight
=R'=21, n=2), the adhesion strength of Cu and Aβ was measured by changing the amount added. The results are shown in Figure 2.

As is clear from FIG. 2, in the anti-sticking rubber composition according to the present invention, the sticking strength decreases rapidly when erucic acid ethyleneamide is added, and when the amount added is 0.5
The results show a considerably better value up to around 20 parts by weight than around 20 parts by weight, and then show a slight upward trend. In any case, in the range of 0.1 to 50 parts by weight, better results were obtained than when it was not added.

In addition, the physical properties of rubber articles manufactured from the anti-sticking rubber composition according to the present invention described above were measured. The results are shown in Table 1 below. In the table, the amount added is shown in parts by weight of erucic acid ethylene bisamide based on 10 parts of the rubber component and parts of Oiit.

Table 1. However, Hs is the hardness measured by a spring type hardness tester, TB is the tensile strength (Kgf/cd), and EB is the elongation at break (%).
) is shown.

As is clear from Table 1 and FIG. 2, the rubber composition according to the present invention can reduce the adhesion strength without sacrificing the physical properties of the rubber composition. It is found that the composition is the best for manufacturing rubber products such as valves, pressure-responsive equipment, etc., where metal and rubber products come into contact.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing the structure of a solenoid valve, and FIG. 2 is a diagram showing the adhesion strength of the rubber composition according to the present invention to Aff and Cu by varying the amount of bisamide added. . 1...Spring, 2...Valve seat, 3...Valve, 30
... Valve body, 31 ... Rubber part, 4 ... Electromagnetic coil.

Claims (1)

[Claims] (1) An anti-sticking rubber composition characterized in that 0.1 to 50 parts by weight of bisamide having the following general formula is added to 100 parts by weight of the rubber component. RCONH(CH_2)nHNOCR' (in the above formula, n is an integer of 1 or more, and R and R' represent an alkyl group having 10 or more carbon atoms).