CS199160B1 - Process for preparing 2-mercaptoimidazoline - Google Patents

Description

The invention relates to a technically and economically advantageous process for the production of technical 2-mercaptoimidazoline (hereinafter referred to as 2-MID), wherein the homogenization with a wetting agent which ensures the dustiness of the final product is carried out in an aqueous suspension.

2-mercaptoimidazoline is used as a vulcanization accelerator for chloroprene rubber. • Its optimal dosage when used alone is 0.5-0.75%. By increasing the accelerator content, higher values of strength, modulus of elasticity and greater vulcanization rate are achieved, but the vulcanization safety is reduced. 2-MID is toxic. More workers are in contact with its production and processing. · With regard to its final form (powdered), it seeks to minimize its harmfulness and ways. For this purpose, admixtures of various substances, e.g. mineral oils, natural and synthetic fatty alcohols, fatty acids, fatty acid esters (solids) and other oily substances. Depending on the desired degree of dustiness of 2-MID, the weight fraction of the additive used is also controlled.

Known processes for adding these ingredients are based on kneading, mixing, fluid mixing the dry product with the ingredient. The most commonly used additives are mineral oils. Technical 2-MID is produced in a non-dusty form by first producing a pulverulent 2-MID and then converting it into a non-dusting form by adding mineral oil in a special device.

The classical method of production has several disadvantages over the invention;

1 / Final processing of untreated 2-MID (drying in cabin dryers and grinding) is accompanied by a significant occurrence of dust in the atmosphere, resulting in a very poor working environment and work hygiene.

2, Before working on the non-dusty form of 2-M1D, this product had to be packaged, tied to mineral oil homogenization, unpacked, and repacked after homogenization.

3 / All these operations are accompanied by loss of the product, consumption of living labor, material and energy, even during documentary work and care.

The above-mentioned disadvantages are eliminated by the method according to the invention, which is based on the fact that the invention is based on the invention

2-MID is produced by condensation of ethylenediamine with carbon disulphide. After condensation prior to crystallization of 2-5113, a product wetting agent is sold into the free solution of the present invention. Mineral oils, carbon-containing fatty alcohols containing ε ^ θ-C ^ q, acids having a carbon number of 10 to 20 or esters thereof are used as non-dusting agents for the product. These compositions are added to the aqueous suspension of 2-MID for isolation at a level of 2-10% by weight to the dry matter of 2-MID.

The aqueous suspension contains about 30% by weight of 2-5%. After crystallization according to flood technology, the crystallized product was isolated, dried, milled, packaged, transported to the homogenization site, unpacked, wetted and repacked. Until tcraz was ready for shipping.

There are no known processes in the literature using the addition of non-dusting additives to the aqueous 2-MID suapens.

In contrast to the flood technology that has been laborious and in poor working environment at finalization, the addition of a composition that provides an adverse effect of 2-10% of 2-10% by weight of the mineral oil will achieve sufficient homogeneity of the final product in the open environment.

Other manufacturing operations. (drying and grinding), the homogeneity is still improved. In addition, manipulation with this non-dusting 2-MID product is essential. In order to obtain the product in a dust-free form, no labor or wage resources, which had to be drawn in the previous case, are needed. In the new method of the invention, energy and material savings are made, and the possibility of using the device and homogenization for other purposes.

There is a significant improvement in the working environment when drying and grinding non-dusting 2-MID. This production method of the invention ensures the production of all 2-MID production in a dust-free form, without any problems and costs in a simple manner. This method of production is of great importance for the rubber industry workers as it improves their working environment and handling of 2-MID.

In the attached figure no. 1 is a diagram showing the production of 2-MID according to the invention. It is a discontinuous method of production.

Condensation 4 is obtained from the basic raw materials ethylenediamine-1-carbon disulphide -2. in aqueous medium, -2 3-mercaptoimidazoline. This is discharged into a crystallization cauldron equipped with a stirrer where crystallization of -5 occurs. Immediately after starting the condensation boiler contents to the crystallizer, mineral oil (26 kg) is added with stirring. 62O pieces of 2-MID are obtained from one batch. After blasting 7.> drying 8? Grinding 9 yielded the final product -10 2-MID las 16o in an undiluted form in an amount of 626 kg. The mineral oil is determined by petroleum ether extraction in an amount of 0.1% by weight relative to 2-MID.

Claims (1)

Preparation of 2-mercaptobenzimidazole not condensed? Iou ethyl? Ndiamínu and carbon disulfide in the water for 'Tred, followed by isolation and drying, 2-nerkaptoimidazolínu using additives providing neprášivost from that of mineral oils, alcohols having a carbon to C _2Q, an organic acid having carbon number of 10 to 20, or esters of said acids and alcohols, characterized in that the non-dusting ingredients of the product are added in an amount of 2 to 10 wt.