SU492091A3 - The method of producing copolymers - Google Patents

Description

minor styrene, which is required in the present invention, is obtained by maintaining a constant ratio of acryloyitrile and styrene monomers in the polymerization medium, in any case, but without permanent retention of the free styrene in the polymerization medium until the majority of the monomers are transformed into polymer. They can be obtained by continuously adding styrene or a mixture of acrnonitrile and styrene to the freezing medium during the polymerization reaction or, at least, until about 70 wt. % monomers do not disturb in the polymer. Then a component of the diene monomer is added, containing sonrea double bonds, and sometimes a small amount of acrylonitrile, styrene, or their mixtures and polyE. The conversion is carried out up to 80-100% of monomers are converted.

The copolymers of this invention are prepared by a polymerization reaction in which a relatively high molar ratio of acryloiitrile to styrene is maintained, and the copolymers are homogeneous and contain more than equimolar to othiochene of polymerization of acryloyitrile to polymerized styrene. The final resins of this invention have excellent properties when compared with compositions of the same monomers prepared by conventional methods.

The polymerization process can be carried out in an aqueous medium, preferably in an aqueous emulsion, in the absence of oxygen and at a temperature of about -100 ° C, at atmospheric, vacuum, or superbarometric pressure.

A conventional polymerization catalyst that creates free radicals as well as radiation — ultraviolet, rep-hept, and nuclear — can be used to initiate polymerization.

To emulsify monomers and polymers in water, MOZHIO use conventional emulsifying and disnergents.

Modifiers with appropriate molecular weights, such as alkyl and aryl mercantanes, can be used in the polymerization process, including l-dodedemal mercaptan, gret-dodecyl mercaptan, and polymeric captans, such as limone-imidmercapta and tetraether of pentaerythritol and | 3-mercantoironionic acid and m. up to 10%, based on the total weight of the monomers.

The product is usually obtained in the form of latex. The finite EPO resin can be regenerated from latex by any suitable means, for example by coagulation with electrolytes or solvents, by freezing.

Other modifiers, including plasticizers, anticoagulants, lubricants, dyes, pigments and solvents, can be added during the polymerization process, so that they do not react chemically.

and did not affect the reaction mixture components.

The resinous products obtained by the method have many ideal properties of thermoplastic resins and at the same time have excellent protective properties against gas and steam, very high deformation temperatures, high tenacity, high bending strength, high hardness, high toughness, resistance to most solvents and low degree of creep.

In addition, they are perfectly processed: they can be extruded, calcined, molded, stretched, shaped, machined and otherwise processed, resulting in colorless, transparent, tough, shock-resistant products and products that have an excellent balance of good chemical, physical and electrical properties.

The products obtained by the proposed method can be successfully used to obtain all types of pressed or molded (injection or compression) products, such as sheets, rods, etc., that can be subjected to subsequent molding with vacuum draw extrusion, etc. They can be expanded, including blowing agents and heating them.

Expanded and unstretched sheets may laminate. These compounds can be used to produce machine parts, such as gears and cams, parts for textile machinery, iaimer of bobbins, shuttles, scuttling machines, as well as containers and pipes, especially for chemical and similar operations that require resistance to corrosive substances, such as for example, in filter presses, electric components, portable boxes, pallets, in radio cabinets, furniture manufacturing, phonograph registration.

Due to their protective properties against gas, these resins are suitable for the production of bottles, boxes, films, sheets, etc., for food packaging.

In the following examples, the number of components is expressed in parts by weight.

Example 1. The resin was obtained in an aqueous emulsion of the following components, (h):

Water 250

Emulsifier1,5

(NH4) 2Si080.05

Acrylonitrile75

Styrene25

Limonendimercaptan 0.7

First, only 10% of the mixture of acrylonitrile, styrene and limonepdimercaptan is included in the polymerization mixture. The polymerization is carried out in the absence of molecular oxygen (before the start - flushing with nitrogen) at 60 ° C, when placed. In the polymerization process, more