Cyanuric triallyl(TAC) production process

- Nov 23, 2018 -

 Cyanuric triallyl(TAC)production process, by an organic solvent under conditions other than the absence of allyl chloride, cyanuric acid tri-sodium allyl chloride and the reaction of allyl chloride was removed by cryogenic distillation in vacuo, with micro filtration membrane separating and removing salts formed, trisodium cyanurate per mole of allyl chloride using 3.9 to 6.0mol, and reacted at _5 ° C to a temperature in the range + intrinsic of 50 ° C or more stages for the reaction.

The reaction is preferably carried out in two stages, the first stage holding the O to + 20 ° C, the conversion rate of 90 to 95%, maintaining a temperature of 30 to 40 ° C in the second stage, the conversion rate reached 100% .

Cyanuric triallyl allyl chloride production process used in an amount of 99-100% by weight of pure allyl chloride. Total reaction time limit of not more than 3 hours total reaction time is the time of the reactants and subsequent reaction of allyl chloride was added to the time.

According to the invention, per mole of allyl chloride using trisodium cyanurate 3.9 to 6.0mol of. However, per mole of trisodium cyanurate used is preferably 4.9 to 5.2 mo I of allyl chloride.

The reaction between the selected temperature range _5 ° C and + 50 ° C, preferably between O and 40 ° C. The method preferably two stages: Here, the first stage counter `should preferably carried out at a low temperature +5 to + 10 ° C, the conversion was 90 to 95%; in the second stage, the reaction is preferably +30 + 40 ° C under continued to a conversion of substantially 100%.

In order to suppress the decomposition reaction (which reduces yields), the reaction was mixed rapidly, so that the addition time corresponding to the largest portion of the total reaction time kept to a minimum. Total reaction time (i.e., after the reaction and the reaction mix was used time) is preferably not more than 3 hours, and preferably less than 2 hours, especially I to 1.5 hours.

Given the high reaction enthalpy, in order to achieve shorter reaction times, it requires strong cooling, for example, industrial cooling with a cooling brine. On an industrial scale, it is particularly effective removal of heat by external cooling circuit having a suitable heat exchanger and circulation pump.

After completion of the reaction, after addition of a suitable polymerization inhibitor (hydroquinone derivative typically is) in the reaction mixture, the volatile components at 40 to 50 ° C and gently distilled off under reduced pressure. After distillation TAC 40 as the liquid to 50 ° C, solid sodium chloride, and the insoluble sodium chloride TAC, TAC give a clear and transparent film centrifuge filtration through a membrane tetrafluoroethylene. Yield significantly more than 95%, TAC was obtained with purity of at least 99.5%, APHA number of O to 10, and greater than or equal to a freezing point of 27 ° C a clear liquid.

The material selection: selection of highly toxic chemicals in place of allyl chloride allyl alcohol, allyl chloride and allyl alcohol having a boiling point lower than can be realized low-temperature vacuum distillation to recover, to avoid discoloration at high temperatures. Trisodium cyanurate selected instead of cyanuric chloride, cyanuric chloride is unstable in air, volatile, corrosive and irritant, it is a strong lachrymator; and trisodium cyanurate, as a stable sodium salt, non-corrosive and irritating. Changes in raw material production workers improved operating environment, reduce the harm to the environment.

Solvent-free salt-forming: the kettle was added a slight excess of allyl chloride, allyl chloride in a slight excess to ensure complete reaction of cyanuric acid trisodium, was slowly added via the vibrating feeder trisodium cyanurate, cyanuric acid generating three and allyl chloride. Allyl chloride is liquid at room temperature, trisodium cyanurate powder solid at room temperature, a solid-liquid direct sufficient reaction, an organic reagent or avoid the use of water as a solvent, reducing the post-liquid separation step.

The low-temperature vacuum distillation process: the trisodium cyanurate, allyl chloride and the reaction sufficiently proceeds cryogenic distillation kettle vacuum distillation, distillation temperature control 35-40 ° C, so that the unreacted allyl chloride was distilled out be recycled, avoiding cyanuric acid at elevated temperature triallyl yellow, improved purity and yield triallyl cyanuric acid.

Continuous membrane filtration purification process: triallyl cyanuric acid is a liquid at 35_40 ° C, solid sodium chloride, and sodium chloride is insoluble cyanuric acid triallyl. The remaining cyanuric chloride and triallyl mixture in the still pot, into a continuous centrifuge tetrafluoroethylene membrane, triallyl cyanuric acid filtration membrane through 0.1 micron tetrafluoroethylene becomes clear and transparent isolated by passing cyanuric chloride, triallyl and industrial crude, reduced water washing step, avoiding the use of water and wastewater treatment, to achieve energy saving.

Compared with the prior art, the beneficial effects of the present invention are:

(1) in the reaction was removed using an acid acceptor in the reaction can be carried out within a short time, and temperature control is not critical to the presently desired, additional APHA color number can be obtained relatively low (i.e., 10 or less) which makes TAC  purity of over 99%, a yield of over 95%.After the reaction and distillation, the TAC-containing solid salts quickly separated from each other, without causing any problems, and recovered allyl chloride can be reused without reducing the quality of the TAC;

(2) as compared to the currently known methods, the method according to the invention is technically easy to implement, with low level of technical complexity of the requirements, because the problem without phase separation and water washing step;

(3) improved product yield, reduced raw material consumption, reducing the production steps employed in the multi-step approach during recycling, saving energy and resources, reduce waste discharge.