JPS62100542A - Vulcanizing accelerator for rubber - Google Patents

Abstract

PURPOSE:A vulcanizing accelerator suitable for tire, tube, etc., effective in vulcanization with a sulfur or organic sulfur-containing compound, having improved dispersibility into rubber, bloom-resistant heat aging characteristics and low vulcanization return, having a specific structure. CONSTITUTION:100pts.wt. rubber (e.g., natural rubber, isoprene rubber, etc.,) is blended with 0.1-10pts.wt. sulfur or organic sulfur-containing compound as a vulcanizing agent and 0.1-10pts.wt., preferably 0.5-5pts.wt. compound [e.g., poly(1,13-dithia-4,7,10-trioxatridecane)-bis-(2-thiabenzothiazole), etc.,] shown by the formula (X is 1-3; n is 1-5) as a vulcanizing accelerator and vulcanized. A weight ratio of the vulcanizing agent/vulcanizing accelerator is 0.1/10-10/0.1, preferably 0.1-5/0.5.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a novel vulcanization accelerator for rubber.

[Prior Art] When vulcanizing natural or synthetic rubber with sulfur or organic sulfur-containing compounds, various vulcanization accelerators are usually used. However, when sulfur or organic sulfur-containing compounds and known vulcanization accelerators are used to vulcanize rubber, blooming and reversion may occur, and dispersibility and heat aging resistance may be poor. Some shortcomings are recognized, such as:

The vulcanization accelerator that overcomes all of these drawbacks at the same time is
It has not been discovered yet.

On the other hand, the present inventors have developed an f-stage that overcomes some of the drawbacks such as bloom and heat aging resistance in the vulcanization of rubber using sulfur, etc. as shown in "-".
We have previously proposed a method in which a polysulfide polymer represented by CH24:H2-53~6+5~1G is used as a vulcanizing agent in combination with a specific vulcanization accelerator (JP-A-57-170939
No. 58-IEi7834, No. 59-213745
(Refer to Japanese Patent Publications, etc.) and the rubber vulcanization performance of the combination of such polysulfide polymer vulcanizing agents and various vulcanization accelerators in the Polymer 11.l Conference (October 2, 1981).
0kuchi, reported by Ona Fortune-ya). At that time, it was reported that a compound having a skeleton structure similar to that of the polysulfide polymer described above was not found to be effective at all as a rubber vulcanizing agent.

[Problems to be Solved by the Invention] In view of the current state of the prior art, an object of the present invention is to provide a vulcanization accelerator which is effective as a vulcanization accelerator during vulcanization with sulfur or an organic sulfur-containing compound, and which is effective in vulcanization in rubber. Excellent dispersibility into
Another object of the present invention is to provide a vulcanization accelerator that simultaneously satisfies the properties of bloom resistance, heat aging resistance, and little reversion of vulcanization.

[First Step to Solve the Problems] In order to achieve the above object, the inventors of the present invention have conducted intensive research and have obtained the following interesting findings. That is, poly(lj3-dithia-4,?,101-oxatridecane)-bis-(2-thiabenzothiazole), poly(1,10-dithia-4, 7-dioxadecane)-bis-(2-thiabenzodeazole), poly(l,
? -Dithia-4-oxahebutane)-bis-(2-thiabenzothiazole) and other compounds represented by the general formula are not found to be effective as rubber vulcanizing agents, but surprisingly, compounds such as sulfur etc. It has been discovered that the present invention can exhibit excellent effects as a vulcanization accelerator that meets the above objectives in the vulcanization of rubber as a vulcanizing agent.

The present invention was completed based on the above findings, and is based on the compound represented by the general formula (wherein, X is a g number of 1 to 3, and n is an integer of 1 to 5). The present invention provides a new rubber vulcanization accelerator consisting of one or more types.

The compound represented by the above general formula of the present invention is used in combination with a vulcanizing agent such as sulfur or an organic sulfur-containing compound as a vulcanization accelerator for rubber. Various examples can be given as the vulcanizing agent to be used in combination with the specific vulcanization accelerator of the present invention, but sulfur or an organic sulfur-containing compound, particularly sulfur, is usually preferred.For example, as sulfur, ordinary powdered sulfur , insoluble sulfur, etc., and organic sulfur-containing compounds include tetramethylthiuram disulfide, tetraethylthiuram disulfide,
dipentamethylenethiuram tetrasulfide, 4.4
'-dithiodimorpholine, 2-(4-morpholinyldithio)-benzothiazole, and the like. Other examples include polysulfide polymer vulcanizing agents disclosed in JP-A-58-187834 and the like.

The vulcanization accelerator of the present invention can be obtained by various synthetic routes, but can usually be easily synthesized according to the following reaction formula.

In this way, for example, in the case of poly(1,7-dithia-4-oxaheptane)-bis-(2-thiabenzothiazole) [hereinafter abbreviated as 0HBT] where X=1, n
A product containing each component of =1 to 5 and other components is synthesized. Also, ! =2 poly(1,10-dithia-4
, Futhioxadecane)-bis-(2-thiabenzothiazole) [hereinafter abbreviated as DODi3T] and poly(1,13-dithia-4,7°10-trioxatridecane)-bis- with x=3 (2-Thiabenzothiazole) [hereinafter abbreviated as TOTDBT] is also synthesized containing each component of n=1 to 5 and other components. These 0HBT, DODBT or TOTDB
All Ts are viscous liquids of reddish-brown to brownish-brown color, and the analysis results by gel permeation chromatography (GPC) are as shown in Table 1 below.

Table 1 (values are area percentages) Notes (1) Nidibenzothiazolyl disulfide The vulcanization accelerator of the present invention is used by being blended into rubber in combination with a vulcanizing agent such as sulfur. In this case, in the vulcanization accelerator of the present invention, X and n can of course be used as a single type of compound, and also as a mixture of two or more different types of X and n. , usually a mixture of two or more types in which n is different, such as 0HBT, DO, as shown in -1-.
DBT, used as 70708 guns. Therefore, the compounding value of the vulcanization accelerator of the present invention in rubber is 100 weight tons of rubber.
: 0.1 to 1070 parts by weight, preferably 0.
It can be selected from a range of 5 to 5.0 parts by weight. In addition, the amount of vulcanizing agent such as sulfur can be selected as appropriate, and rubber 10
0.1 to 10.0 parts by weight of the vulcanizing agent. The amount of Oi is preferably about 0.1 to 5.0 parts by weight. In addition,
The ratio of the vulcanization accelerator of the present invention to the vulcanizing agent, such as sulfur, can vary over a wide range and is usually a vulcanizing agent/accelerator weight ratio of 0.1/10.0-10. 01
0.1 degree, preferably 0.115.0 to 5.010.
5 or so may be adopted.

The types of rubber that contain uninvented vulcanization accelerators include:
A wide range of conventionally known and well-known natural rubbers and synthetic rubbers are exemplified, and synthetic rubbers include imprene rubber (IR), butadiene rubber (BR), and butyl rubber (
IIR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene terpolymer (EPDM), chloroprene rubber (OR), etc.
It may be a blend of more than one type of rubber.

Furthermore, when manufacturing rubber products using the vulcanization accelerator of the present invention, zinc oxide, magnesium oxide, lead oxide, fatty acids, and existing fillers and reinforcing agents are usually used as vulcanization activators and auxiliaries. , a softener, etc., and in some cases, a known vulcanization accelerator may also be used in combination.

Depending on the purpose, anti-foaming agents such as N-isopropyl-H'-phenyl-P-phenylenediamine (IPPD) may also be used.
), N-ctyl-N'-phenyl-p-phenylenediamine (OPPD), 2,2,4-trimethyl-1
, 2-dihydroquinoline compound (TMDQ), 8-ethoxy-2,2°4-trimethyl-1,2-dihydroquinoline (ETMDQ).

Resin-like condensate of acetonate and diphenylamine (ADPA)
R), t Kuchi) L, Kashifuz = Lua Mi7 (OD
PA).

2.6-di-tert-butyl-4-methylphenol (DT
BMP).

Styrenated phenol (SP), 2,2-methylenebis(4-methyl-et-butylphenol 4,4'
-Use together with one or more of -butylidene bis(3-methyl-6-t-butylphenol) [BBMTBP], nickel dibutyldithiocarbamate (NiDBC), 2-mercabutobenzimitazole (MHI), etc. You can also do it.

To vulcanize rubber using the vulcanization accelerator of the present invention, a vulcanization operation similar to that for vulcanization of a rubber composition containing a conventional sulfur- or organic 4i & yellow compound and a vulcanization accelerator is carried out.・
Articles +1-, etc. may be adopted.

[Examples] Examples of the present invention will be described in more detail below, but it goes without saying that the present invention is not limited by such explanations. Incidentally, the blending ratios are in parts by weight unless otherwise specified.

Examples 1 to 3 and Comparative Example 1 The formulation table is shown in Table 2. The blending method, procedure, and conditions are 5RIS
-3604, O, D, R, to 5RIS-3105,
The results are shown in Table 3.

Table 2 Note (2): Octylated diphenylamine (ODPA) Table 3 Note (3) Nidibenzothiazolyl disulfide (MBTS
) From the results in Table 3, it can be seen that all of the compounds of the present invention are effective as vulcanization accelerators, and moreover, the vulcanization recovery is significantly improved compared to conventional vulcanization accelerators.

Table 4 shows the formulations of Examples 4 to 6 and Comparative Examples 2 to 4. The blending method and f order 1 conditions are as in Example 1~
3, and the physical test method for unvulcanized rubber is JISK.
8300. The procedure for making vulcanized rubber is 5RIS 3804
Physical tests for the vulcanized rubber were conducted in accordance with J15K6301. The results are shown in Table 5.

Table 4 From the results in Table 5, the compound of the present invention is effective as a vulcanization accelerator, has less vulcanization recovery than existing vulcanization accelerators, and
It can be seen that the heat aging resistance is also good, particularly in Example 6, the heat aging resistance is extremely good and there is very little reversion of vulcanization.

Examples 7 to 9 and Comparative Example 5 The compounding table is shown in Table 6, and the compounding method, procedure, and procedure for making vulcanized rubber are based on Examples 4 to 6, and the bloom state of the unvulcanized and vulcanized rubber surfaces is The results are shown in Table 7.

Table 6 Table 7 Note (6); After 3 months left indoors Note (7) After 3 months left indoors, vulcanization condition 140℃ x 30
From the test results in Table 7, it can be seen that no bloom phenomenon is observed in rubbers containing the compound of the present invention, regardless of whether they are unvulcanized or vulcanized.

[Effects of the Invention] Because the vulcanization accelerator of the present invention is liquid, it has excellent dispersibility in rubber, and there is no bloom, and the vulcanized rubber products have good vulcanized physical properties and excellent heat aging resistance. This property, in which there is extremely little reversion of vulcanization, makes the rubber composition vulcanized using the vulcanization accelerator of the present invention valuable for rubber products such as tires, tubes, anti-vibration rubber, belts, and hoses. This indicates that the rubber composition has a high

Claims (1)

[Claims] 1. General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, x in the formula is an integer from 1 to 3, and n is an integer from 1 to 5. A vulcanization accelerator for rubber comprising one or more compounds represented by (integer).