RU2028310C1 - Method of polybutadiene synthesis - Google Patents

Abstract

FIELD: industry of synthetic rubber. SUBSTANCE: method involves polymerization of butadiene-1,3 in toluene medium in the presence of n-butyllithium and divinylbenzene in battery of at least 5 reactors. Charge has 15-20% monomer which is divided for two flows at the ratio from 1:2.5 to 1:8 which were fed into the 1-st and 3-d reactor, respectively. Into the first reactor n-butyllithium is added at the molar ratio with monomer from 1:370 to 1:530; into the second reactor divinylbenzene is added at the molar ratio with n-butyllithium from 0.1:1 to 0.4:1. Polymerization into the 1-st and 2-d reactors is carried out at 30-50 C, and in the rest ones - at 50-100 C. EFFECT: improved method of synthesis. 1 tbl

Description

 The invention relates to a technology for producing high molecular weight polybutadiene and can be used in the synthetic rubber industry, and the resulting product is in the tire, rubber and rubber industries, in the production of high impact polystyrene and other industries.

 A known method of producing polybutadiene by polymerization of butadiene-1,3 in hexane in the presence of n-butyl lithium and diethylene glycol dimethyl ether in a tubular reactor with a periodic decrease and increase in the supply of catalyst / 1 /.

In this case, polybutadiene with a polydispersity index / M _w / M _n / 2.55-3.16 but with a high content of vinyl units, unsatisfactory cold flow, milling and sprinkling is obtained.

 Closest to the invention in technical essence and the achieved result is a known method for the polymerization of butadiene-1,3 in toluene under the action of an organolithium initiator, chain reduction with divinylbenzene / 2 / is used to reduce cold flow.

 The disadvantage of this method is the unsatisfactory cold flow, the duration of the cliff stage, which reduces productivity, the inability to obtain macromolecules of the desired branching.

An object of the invention is to obtain polybutadiene with satisfactory properties: molecular weight distribution, microstructure, cold fluidity / or fluidity at 90 ^about C /.

The specified technical result is achieved by the fact that in the method for producing polybutadiene by continuous polymerization of butadiene-1,3 in a battery of reactors in series in the environment of toluene in the presence of n-butyl lithium and divinylbenzene, the process is carried out in a battery consisting of at least five reactors, a mixture containing butadiene -1.3, 15-20 wt.% Is divided into two streams in a mass ratio of 1: 2.5 to 1: 8 and they are fed, respectively, into the first and third reactors, n-butyllithium is introduced into the first reactor at a molar ratio n-butyllithium: utadiene-1.3 from 1: 370, to 1: 530, divinylbenzene is introduced into the second reactor at a molar ratio of divinylbenzene: n-butyl lithium from 0.1: 1 to 0.4: 1, and the polymerization process in the first and second reactor is carried out at 30-50 ^о С, and in other reactors at 50-100 ^о С.

 After the polymerization, the catalyst is deactivated and the polymer is stabilized by introducing into the polymerizate a solution of the antioxidant - agidol-2 / NG-2246 / in an amount of 0.2-0.8 wt.%. Isolation of polybutadiene is carried out by known methods by aqueous degassing and drying on LK-8.

The resulting polymer Mooney viscosity, plastichnoctyu, cold flow or fluidity at ⁹⁰ ° C, microstructure, molecular weight distribution, a weight loss on drying at 105 ° ^C.

The polymerization of butadiene-1,3 is carried out in a battery consisting of at least five reactors with a capacity of 16.6 m ³ , each with a total monomer load of 3.0-3.6 t / h.

 A solution of n-butyllithium and divinylbenzene with concentrations of 0.2-0.3 mol / l and 10-15 g / l, respectively, is introduced into the mixture / polymerizate / by intensive mixing in a volumeless mixer.

 The process temperature is maintained in the reactors by supplying refrigerant (or hot water) to the jacket of the reactor.

 The absolute values of the process conditions are calculated from the data presented in the table, which also shows the characteristics of the polymer.

PRI me R 1 (as known). Cooled to a temperature of (-20) - (- 25) ^о С butadiene-1,3 in the amount of 3 t / h is mixed with toluene based on the concentration of the mixture of 15 wt.% / 17 t / h / in the pipeline and fed to the first battery reactor . Immediately in front of the reactor, a toluene solution of n-butyllithium is fed, based on its molar ratio to monomer 1: 1200. The process of polymerization of 1,3-butadiene is carried out in the five reactors ^at 40 ° C in the first, 50 ^{° C} in the second and 60 ° ^C in the third, fourth and fifth. A solution of divinylbenzene is introduced into the polymerizate after the fourth reactor based on the ratio of divinylbenzene: n-butyl lithium 0.5. The total polymerization time of 3.4 hours

 PRI me R 2. The mixture prepared by mixing 3.6 t / h of butadiene 1.3 and 17.6 t / h of toluene, served in the first and third reactors based on the monomer 0.4 t / h and 3 , 2 t / h, respectively.

 After the first reactor, a divinylbenzene solution is fed into the volumeless mixer based on its molar ratio to n-butyl lithium 0.1.

 The polymerization time of the main stream of the mixture of 1.9 hours

 PRI me R 3. The prepared mixture by mixing 3.5 t / h of butadiene-1.3 and 19.8 t / h of toluene is fed into the first and third reactors based on the monomer 0.7 t / h and 2, 8 t / h, respectively.

 After the first reactor, a solution of divinylbenzene is fed into the volumeless mixer based on its molar ratio to n-butyl lithium 0.2.

 The polymerization time of the main stream of monomer 1.8 hours

 PRI me R 4. The prepared mixture by mixing 3.5 t / h of butadiene-1.3 and 14 t / h of toluene is fed into the first and third reactors based on the monomer 1.0 t / h and 2.5 t / h, respectively.

 After the first reactor, a solution of divinylbenzene is fed into the volumeless mixer based on its molar ratio to n-butyl lithium 0.2.

 The polymerization time of the main stream of monomer 1.8 hours

 PRI me R 5. The prepared mixture by mixing 3.5 t / h of butadiene-1.3 and 14 t / h of toluene is fed into the first and third reactors based on the monomer 1.0 t / h and 2.5 t / h, respectively.

 After the first reactor, a divinylbenzene solution is fed into the volumeless mixer after calculating its molar ratio to n-butyl lithium 0.4.

 The polymerization time of the main flow of the monomer of 2.3 hours

Claims (1)

METHOD FOR PRODUCING POLYBUTADIENE by continuous polymerization of butadiene-1,3 in a battery of reactors arranged in series in the environment of toluene in the presence of n-butyllithium and divinylbenzene, characterized in that the process is carried out in a battery consisting of at least five reactors, a mixture containing 15 to 20 wt. .% butadiene-1,3, is divided into two streams in a mass ratio of from 1: 2.5 to 1: 8.0 and feed them respectively to the first and third reactors, n-butyllithium is introduced into the first reactor at a molar ratio of n-butyllithium : butadiene-1.3 from 1: 370 to 1: 530, in Torah divinylbenzene introduced into the reactor at a molar ratio divinyl benzene: n-butyl lithium of from 0.1: 1 to 0.4: 1, wherein the polymerization process in the first and second reactors is carried out at 30 - 50 ^o C, and the remaining reactors - at 50 - 100 ^o C.

Images