JPH0446295B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a silane crosslinkable halogenated polymer composition using and mixing low molecular weight chloroprene as a softening agent. <Prior art> Conventionally, halogenated polymer compositions that can be crosslinked with silane have problems in processability, and in order to improve processability, process oils (e.g., naphthene) are generally used as softeners. Mooney viscosity is adjusted by adding oils such as paraffin-based and paraffin-based oils. <Problems to be Solved by the Invention> However, when the above-mentioned process oil is added, the mechanical strength of the halogenated polymer composition is significantly reduced, which poses a practical problem. <Means for Solving the Problems> The present invention was made in view of the above-mentioned conventional situation, and its characteristic structure is that a type of low molecular weight chloroprene is used in place of the conventional process oil. A halogenated polymer composition is prepared by mixing 5 to 80 parts by weight of this chloroprene and 0.1 to 20 parts by weight of an amino group-containing organosilane compound to enable silane crosslinking to 100 parts by weight of a halogenated polymer. be. Further, if necessary, commonly used fillers, anti-aging agents, lubricants, colorants, etc. can be added to the composition of the present invention. Here, low molecular weight chloroprene refers to one with a viscosity of about 800,000 to 1,200,000 centipoise at 50°C. For example, as a commercially available product, neoprene
Examples include FB and neoprene FC. These low molecular weight chloroprenes are solid at room temperature;
If it is added as a softener to the above-mentioned silane-crosslinkable halogenated polymer composition, it will become liquid at temperatures above 50 degrees Celsius. softens and becomes easier to process. In addition, since the chloroprene becomes solid due to the temperature drop after molding, it does not lose its shape and has good shape retention. The reason for setting the mixed amount of addition to 5 to 80 parts by weight is that if it is less than 5 parts by weight, the effect of improving workability and good shape retention cannot be obtained, whereas if it exceeds 80 parts by weight, the vulcanizate This is because the mechanical strength of the material decreases, which poses a practical problem. Further, examples of the amino group-containing organic silane compound used in the present invention include those represented by the following general formula. RR′ _o SiX _3-o (wherein, R is an organic group having 20 or less carbon atoms bonded to silicon via a silicon body carbon bond, and the R group can also be carbon, hydrogen, nitrogen, and optionally oxygen. and contains at least one amino group, R' is a monovalent hydrocarbon group having 1 to 9 carbon atoms, X is an alkoxy or alkoxyalkoxy group having 1 to 6 carbon atoms, or (oxime group having 14 carbon atoms or less, n is 0 or 1) More specific examples of such amino group-containing organic silane compounds include r-aminopropyltriethoxysilane, r-aminopropyltriethoxysilane, Examples include methoxysilane, N-methylaminopropyltriethoxysilane, and N-phenylaminopropyltrimethoxysilane. The addition amount was set at 0.1 to 20 parts by weight because if it was less than 0.1 part by weight, the crosslinking density of the crosslinked product would be low, resulting in insufficient mechanical strength and practical problems as a rubber-like elastic body. If it exceeds 20 parts by weight, the crosslinking density will increase and the elongation of the crosslinked product will decrease, causing practical problems.
It is also disadvantageous as it increases costs. Further, the halogenated polymer that is the base polymer of the present invention may be any ordinary rubber or plastic containing a halogen element, such as polychloroprene (neoprene W) having a normal molecular weight, chlorosulfonated polyethylene, etc. , epichlorohydrin rubber, etc. can be used. In actual use, the crosslinkable composition is applied by pressing, extrusion, injection, etc.
During shaping, crosslinking is effected by direct contact with moisture in the presence of a silanol catalyst or without the catalyst. This crosslinking can be carried out at normal temperature and pressure. <Function> In the present invention, as mentioned above, low molecular weight chloroprene becomes liquid due to the heat of processing during processing, which increases the fluidity of the base polymer and improves the processability of the entire resin. As the temperature decreases, low molecular weight chloroprene solidifies and
Since it is a crosslinked product, it maintains its shape well, does not lose its shape, and has little decrease in mechanical strength. <Example> Table 1 shows the compounding composition of Example 1 of the present invention and Comparative Example 1, which is a conventional example. Further, Table 2 shows various properties such as tensile strength of the compositions according to each of the above examples.

【table】

[Table] From Tables 1 and 2 above, it can be seen that Example 1 of the present invention, in which low molecular weight chloroprene was used as a softener, had high mechanical strength. On the other hand, it can be seen that the mechanical strength of Comparative Example 1 using process oil is weak. Furthermore, in the case of Example 1 of the present invention, the shape retention after molding was better than that of Comparative Example 1. <Effects of the Invention> According to the present invention, as is clear from the above explanation, since low molecular weight chloroprene is added as a softening agent, it has good processability and good shape retention, and does not lose its shape. An excellent halogenated polymer composition can be obtained.

Claims (1)

[Claims] 1 100 parts by weight of halogenated polymer, low molecular weight (viscosity at 50°C: 800,000 to 1,200,000 centipoise)
A halogenated polymer composition characterized in that it is formed by mixing 5 to 80 parts by weight of chloroprene and 0.1 to 20 parts by weight of an amino group-containing organic silane compound.