SU852881A1 - Method of preparing perchlorovinyl resin - Google Patents

Description

The invention relates to the field of producing macromolecular compounds and can be used to produce perchlorovinyl resin.

Industrial methods for producing perchlorovinyl resin include two sequential steps: polymerization of vinyl chloride and chlorination of polyvinyl chloride resin. Polyvinyl chloride resin is obtained by suspension polymerization of chlorovinyl in the aqueous phase in the presence of an initiator, for example porophore, at 49.5 ° C. Reaction time 2U — 24 hours

The resulting polyvinyl chloride resin with a molecular weight of 66666–63606 and an organically bound chlorine content of b7: 7 ° is further chlorinated in an organic solvent in the presence of an initiator.

Chlorination is carried out in tetrachloroethane at 60–100 ° С [1]; in dichloroethane [2] or in chlorobenzene at 80–90 ° С [3].

The resulting solution of perchlorovinyl resin in an organic solvent resulting from chlorination is sent to the planting site where the solvent is removed and regenerated and the planted resin is dried. The perchlorovinyl resin thus obtained contains May 62–63.5. % organically bound chlorine.

. The described method for producing perchlorovinyl resin is characterized by a number of significant disadvantages:

multi-stage process;

the use of an organic solvent, which is associated with a time-consuming and energy-intensive system of its regeneration;

the presence of a large amount of wastewater contaminated with organochlorine products, hydrochloric acid, active chlorine;

significant corrosion of the chlorination process.

The aim of the invention is the intensification of the process for producing the resin and simplification of the technological scheme of its production.

This goal is achieved by the fact that they carry out suspension copolymerization of ₂₀ chlorovinyl with 1,2-dichloroethylene with a molar ratio of chlorovinyl and 1,2-dichloroethylene 3–3.5: 1 at 48–50 ° C in the presence of azodiisobutyronitrile.

To ensure the required dispersion of the resin, polymerization is carried out in the presence of 0.06–0.3 May. % on the aqueous phase of the surfactant, and the dosage of chlorovinyl into the reactor is carried out continuously during the first 10-30 hours of the process, after which it is kept 852881 ka with the stirrer working for 10-20 hours.

At the end of the polymerization, the pressure is vented from the reactor, the resin is filtered off from the mother liquor and dried.

The perchlorovinyl resin thus obtained contains May 62–63.5. % organically bound chlorine and is characterized by the Fikentcher constant 47-60.

Example 1. 1.8 kg of water, 0.47 kg of 1,2-dichloroethylene, 6.0 g of methyl cellulose and 2.8 g of azodiisobutyronitrile are charged into a 4 L polymerization reactor equipped with a stirrer and a heat transfer jacket. The system is deoxygenated by purging with nitrogen and heated. After reaching a temperature of the reaction mixture of 48 ° C, chlorovinyl at a rate of 90 g / h is started to be dosed into the reactor with the stirrer operating. At the end of the dosage 900 g of chlorovinyl (10 h), the reaction mixture is aged at 48 ° С and stirred for another 26 h. After the polymerization reaction (36 h in total), the reactor is cooled and 1294 g of resin, 1.8 g of water are discharged and 72.0 g HYORVYYLAS Conversion of 1,2-dichloroethylene 919.2%. Chlorovinyl 92%. Resin yield 99.2% of theory, assuming loaded 1,2-diA'lor!)

The resin is characterized by the following indicators: Fikkentcher constant 50.2; the content of organically bound chlorine May 62.5. %; solubility in a mixture of solvents according to GOS'1 10004-72 99.9 ^and / o Example 2. 1.8 kg of water, 6.49 kg of 1,2-dichloroethylene are loaded into the reactor (see Example 1); 6.0 g of methyl cellulose and 2.8 g of azodiisobutyronitrile.

After deoxygenation of the system and reaching the temperature of the 4С С reaction mixture, chlorovinyl at a rate of / g / h is started to be dosed into the reactor with the stirrer operating. At the end of the dosage 1100 g of chlorovinyl (16.8 hours), the reaction mixture is aged at 49 ° C and stirred for another 20 hours. After the polymerization reaction (35 hours in total), the reactor is cooled and 14.37 g of resin are discharged, 1.8 kg of water and 158 g of chlorovinyl. The conversion of 1,2-dichloroethylene is 99.1%, of chlorovinyl 95.7%.

The resin yield is 99.1% of theory, based on the loaded 1,2-dichloroethylene. The resin is characterized by the following indicators: Fikkentcher constant 60.0; the content of organically bound chlorine is 62.3%, the solubility in a mixture of organic solvents according to GOST 10004-72 is 99.8%.

Example 3. In the reactor (see example 1), load 1.8 kg of water, 0.49 kg of 1,2-dichloro ethylene, 4.0 g of methyl cellulose and 2.8 g of azodiisobutyronitrile. After deoxygenation and reaching a temperature of the reaction mixture of 50 ° C in the reactor with a working stirrer, chlorovinyl is started to be dosed at a rate of 110.5 g / h. At the end of the dosage 1105 g of chlorovinyl (10 h), the reaction mixture is aged at 50 ° С and stirred for 20 h. After the polymerization reaction (30 h in total), the reactor is cooled and 1436 g of resin, 1.8 kg of water and 159 g are discharged vinyl chloride. The conversion of 1,2-dichloroethylene is 99.6%, of chlorovinyl 85.6%. The resin yield is 99.6% of theory, based on the loaded 1,2-dichloroethylene. The resin is characterized by the following indicators: Fikkentcher constant 47.5; the content of organically bound chlorine 63.2%; solubility according to GOST 10004-72 99.9%.

The proposed method for producing perchlorovinyl resin in comparison with the known method completely excludes from the technological scheme of industrial production of perchlorovinyl resin the following stages:

chlorination of the resin in organic solvents;

solvent regeneration by rectification;

utilization of chlorine and chlorine-containing gases.

The corrosivity of the medium is completely eliminated, the technology is greatly simplified, which generally increases the technical and economic indicators of production.

Thus, the invention will allow to obtain perchlorovinyl resin by a simplified technology and with a higher yield.

Claims (1)

Claim A method for producing perchlorovinyl resin, characterized in that, in order to intensify the process of obtaining resin and simplify the technological scheme of its production, chlorovinyl is suspended in a suspension copolymerization with 1,2-dichloroethylene with a chlorine vinyl and 1,2-dichloroethylene molar ratio of 3: 3.5: 1 at 48-50 ° C in the presence of azodiisobutyronitrile.