JPS59126444A - Vulcanization promotor for chlorine-containing rubber - Google Patents

Abstract

PURPOSE:The titled vulcanization promotor having stability to scorching properties, extremely high vulcanization speed, and improved physical properties such as heat resistance, etc., comprising 2-methyl-4,6-bis(dimethylaminomethyl)phenol as an active ingredient. CONSTITUTION:The desired vulcanization promotor comprising 2-methyl-4,6- bis(dimethylaminomethyl)phenol obtained by reacting 2-methylphenol with formaldehyde as an active ingredient. 100pts.wt. chlorine-containing rubber is blended with 0.5-3pts.wt. vulcanization promotor.

Description

[Detailed description of the invention] The present invention relates to a vulcanization accelerator for chlorine-containing rubber.

Chlorine-containing rubbers such as chloroprene rubber and chlorosulfonated polyethylene rubber have various characteristics such as excellent ozone resistance and weather resistance, and are flame retardant.
It is used in many applications such as electric wires, industrial supplies, and automobile parts.

Conventionally, the mainstream method for vulcanizing chlorine-containing rubber has been to use 2-mercaptoimidacillin as a vulcanization accelerator, but it has the disadvantage of being prone to scorch, which is a major problem in the processing of rubber. Even if the amount used was reduced, the scorch was not improved, and there were problems such as a delay in the normal vulcanization rate and poor physical properties of the vulcanized rubber.

For this reason, various methods have been investigated, such as methods using thiourea compounds, catechol derivatives, etc. as vulcanization accelerators, but these methods are still not satisfactory.

For example, as a vulcanization accelerator for chlorine-containing rubber, 2,6-disubstituted-4-dimethylaminomethylphenol (JP-A-5
0-151289) and 2.4.6-tris(dimethylaminomethyl)phenol (JP-A-50-1519)
No. 51) has been studied, but although all of these have stable scorch properties, the vulcanization rate is also slow, which poses a problem for practical use.

For this reason, the present inventors investigated various compounds in order to accelerate the vulcanization rate in the above-mentioned phenolic manninhibases, and found that 2-methyl-4,6-
Not only is bis(dimethylaminomethyl)phenol stable against scorch, but it also has a uniquely fast vulcanization rate, and the resulting vulcanized rubber has excellent physical properties such as heat resistance. The present invention was based on this discovery.

That is, the present invention provides a material that has stable scorch properties, has a fast vulcanization rate, and has excellent physical properties such as heat resistance, which uses 2-methyl-4,6-bis(dimethylaminomethyl)phenol as an active ingredient. The object of the present invention is to provide a chlorine-containing rubber vulcanization accelerator capable of producing vulcanized rubber.

2-Methyl-4,6-bis(dimethylaminomethyl)phenol in the present invention can be easily produced, for example, by reaction of 2-methylphenol, dimethylamino, and formaldehyde.

In addition, the chlorine-containing rubbers targeted in the present invention, chlorine-containing rubber, chlorosulfonated polyethylene rubber,
These include epichlorohydrin rubber and chlorinated polyethylene, but it is particularly effective against chloroprene rubber.

2-Methyl-4,6-bis(dimethylaminomethyl)phenol can be prepared by conventional methods such as Banbury mixer,
Mixed with chlorine-containing rubber in a mixer such as an open roll,
The amount used is usually 0.3 to 5 parts per 100 parts by weight of rubber.
Parts by weight, preferably 0.5 to 3 parts by weight.

In addition, when using the vulcanization accelerator of the present invention, other commonly used additives such as magnesium oxide,
Metal oxides such as zinc oxide, carbon black, silicas, various reinforcing agents such as clay, sulfur, anti-aging agents, etc. may be used, and if necessary, other vulcanization accelerators may be used. Good too.

Thus, when the vulcanization accelerator of the present invention is used as a vulcanization accelerator for chlorine-containing rubber, the scorch property is stable, the vulcanization rate is fast, and the resulting vulcanized rubber has excellent physical properties. Shows excellent effects as a vulcanization accelerator.

The present invention will now be explained with reference to Examples.

Example 1 According to a conventional method, a rubber compound was prepared by mixing the following compounding ratios using an open roll.

(Composition) Chloroprene rubber (W type) 100 parts by weight Zinc oxide 5 Magnesium oxide 4 Kestearic acid 1 //SAF black
4o Process oil
1o 〃 Vulcanization accelerator (listed in Table 1) j ''The obtained rubber compound was subjected to a Mooney scorch test in accordance with JISK-6300 and a rheometer vulcanization test to examine the vulcanization rate. Further, press vulcanization was performed at a temperature of 160° C. for 40 minutes at the vulcanized portion, and the physical properties of the vulcanized rubber were measured according to JIS K-6801.

The heat aging was performed at 120° C. for 4 days using a test tube heat aging machine.

These results are shown in Table-1.

Example 2 (Blend) Chloroprene rubber (G type 1007iii parts Zinc oxide 5 Magnesium oxide 4 Stearic acid 1 / Light calcium carbonate
7o 7/process oil IQ,
.

Titanium oxide 20,, Vulcanization accelerator (listed in Table 2) ■.

Claims (1)

[Claims] A chlorine-containing vulcanization accelerator for rubber containing 2-methyl-4,6-bis(dimethylaminomethyl)phenol as an active ingredient.