JPS6142508A - Crosslinking of halogenated rubber - Google Patents

Abstract

PURPOSE:To crosslink a halogenated rubber extremely smoothly at a high reaction rate under a condition of normal temperature and normal pressure, by adding an aminosilane coupling agent of a specified secondary amine structure. CONSTITUTION:A crosslinkable mixture is obtained by mixing 100pts.wt. halogenated rubber with 0.1-20pts.wt. aminosilane coupling agent having a structure of the formula (wherein R is alkyl or phenyl, R' is alkylene, R'' is 1-6C alkoxy, alkoxyalkoxy and n is 0 or 1) and 0-5pts.wt. silanol catalyst. This mixture is contacted with water to crosslink the rubber.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for crosslinking halogenated rubber by silane crosslinking.

<Prior art> Various types of cross-linked structures using silane cuff pulling agents for halogenated rubber have been proposed. For example, methods for cross-linking vinyl silane with DCP (dicumyl peroxide), There are a method of crosslinking a halogenated rubber with a mercaptosilane, a method of crosslinking a halogenated rubber with a primary aminosilane, etc.

(Problem to be solved by the invention) However, in the case of the above DCP, high temperature treatment (100
℃ or higher), and when considering high-temperature processing equipment, heat management costs, etc., it is not practical. In addition, when using mercaptosilane, the mercaptosilane reacts with halogenated rubber, so it is necessary to use diamine compounds, amine salt compounds, etc. in combination, and it is difficult to react sufficiently with the polymer at room temperature, and at the same time, the crosslinking speed is There are problems such as slow speed and poor productivity. Furthermore, in the case of primary aminosilanes, although some crosslinked products can be obtained, although the overall reaction rate is rather slow, crosslinking takes place particularly quickly, so once mixed with halogenated rubber, The admixture has a short shelf life, and during extrusion processing,
It has problems such as easy scorch (early crosslinking).

(Means for Solving the Problems) The present invention was developed in view of the conventional circumstances as described above.
1 = something. The main feature of this method is that, among the silane coupling agents for halogenated rubber, it was found that those with a secondary amine structure are the most preferable, and the use of an aminosilane coupling agent with the specific structure. be.

The specific configuration of the present invention is as follows: halogenated rubber 10
0 parts by weight, and the specific structure of RHNR' Si (OR') 5-11 (wherein, R is an alkyl group or a phenyl group, R' is an alkylene group, and R# is an alkoxy group having 1 to 6 carbon atoms or alkoxyalkoxy group, n is 0 or 1).
This is a crosslinking method for halogenated rubber, in which a crosslinkable mixture is prepared by mixing 1 to 20 parts by weight of a silanol catalyst and 0 to 5 parts by weight of a silanol catalyst, and the mixture is brought into contact with water to be crosslinked. Furthermore, in the crosslinking method of the present invention, commonly used fillers, anti-aging agents, lubricants, colorants, etc. can be added as needed.

Examples of the halogenated rubber used in the present invention include polychloroprene, chlorosulfonated polyethylene, epichlorohydrin rubber, halogenated butyl rubber, and halogenated ethylene propylene rubber.

Further, as the aminosilane coupling agent, for example, N
-phenylaminopropyltrimethoxysilane, N-phenylaminopropyltriethoxysilane, N-methylaminopropyltrimethoxysilane, N-ethylaminopropyltriethoxysilane, and the like. Through actual research by the present inventors, this secondary aminosilane coupling agent is not particularly fast at the start of the reaction compared to the same type of primary agent, but once the reaction starts It has been found that once started, the overall reaction rate is greatly improved. and,
The amount added is 111 parts by weight of 0.1 to 20 parts and 1 to 2 parts by weight.
．． If the amount is less than 0.1 part by weight, the desired 54゛ double bridge effect cannot be obtained, and if it exceeds 20 parts by weight, the desired 54゛ double bridge effect will not be obtained. This is because the elongation of 5'fh is so small that it cannot be put to practical use.

Mano, 2. It is preferable to add the above silanol catalyst in terms of the crosslinking reaction promotion effect, but in the 4th invention, 5. Addition of an aminosilane coupling agent.
Since the halogenated rubber can take a crosslinkable state, it may not be added. When added, it is sufficient to add 5 parts by weight or less in view of the effect; if the amount is more than this, it becomes uneconomical and scorch occurs.

For actual crosslinking, a mixture of halogenated rubber and an aminosilane coupling agent (with a silanol catalyst added if necessary) is mixed at a temperature of 100°C or lower, extruded at a temperature of 100°C or lower, molded, and then molded at room temperature. Either leave it in the air or immerse it in warm water.

Effect> In the present invention, as described above, by adding the aminosilane coupling agent having a specific secondary amine structure, the halogenated rubber is crosslinked at a fast reaction rate and extremely smoothly at room temperature and pressure.

<Example> A mixture was prepared at a temperature of 100° C. or lower according to the first combination ratio, and an extrusion molded product was obtained from this mixture at a temperature of 100° C. or lower.

Table 1 (Blending ratio) When we investigated the physical properties of the molded product obtained with this blend, we found that:
The results shown in Table 2 below were obtained.

From this Table 2, the crosslinking power of the present invention'? It can be seen that the crosslinked product according to A satisfies the required characteristics for coverings of electric wires and cables, other molded products, and even hoses, and is therefore practical.

(Effects of the Invention) According to the present invention, as is clear from the above explanation, a silane coupling agent for halogenated rubber and 1-1. Among aminosilanes, those with a secondary amine structure can be used. Therefore, the overall reaction rate is fast, and unlike primary amines, crosslinking does not occur too quickly, and even after being mixed with halogenated rubber, it can be stored for about half a day to one day. It is possible to provide an excellent method for crosslinking halogenated rubber, which has advantages such as no problems such as overuse, and less scorch (early crosslinking) during processing.

Claims (1)

[Claims] 100 parts by weight of halogenated rubber and the structure of RHNR'Si(OR'')_3_-_n (however,
R is an alkyl group or a phenyl group, R' is an alkylene group, R'' is an alkoxy group or an alkoxyalkoxy group having 1 to 6 carbon atoms, and n is 0 or 1). A method for crosslinking halogenated rubber, comprising mixing 1 to 20 parts by weight of silanol catalyst and 0 to 5 parts by weight of a silanol catalyst to form a crosslinkable mixture, and crosslinking the mixture by contacting it with water.