DE1132716B - Process for the production of finely divided plasticized polyvinyl chloride powder - Google Patents

Description

GERMAN

PATENT OFFICE

C 15411 IVd / 39b

REGISTRATION DATE: AUGUST 31, 1957

NOTICE
THE REGISTRATION
AND ISSUE OF THE
EDITORIAL: JULY 5, 1962

In addition to the processing of plasticizer-free polyvinyl chloride, its processing also plays a role Plasticizers play an important role in the production of molded articles such as foils, artificial leather and hoses and profiles. The mixing of the polyvinyl chloride with the plasticizers is done in kneaders or Mixers. This process takes a fair amount of time and does not lead to a homogeneous one Distribution of the plasticizer on the polyvinyl chloride particles. As a result, it is for some processing purposes often a homogenization with supply of heat, d. H. a gelation before the Further processing necessary. One strives for one especially for processing in injection molding machines ideal distribution of the plasticizer on the polyvinyl chloride particles, since the mixing is no longer too intense during the gelling process in the screw conveyor.

It has been found that finely divided, plasticized polyvinyl chloride powder which can be processed excellently without any further treatment, can be prepared characterized in that aqueous, polyvinyl chloride and liquid plasticizer suspensions containing or emulsions at temperatures of 110 to 180 ^0C to spray drying and the spray drying is followed by a treatment of the polyvinyl chloride with a hot air or inert gas stream at temperatures of 140 to 200 ° C. In this simple way, a completely homogeneous distribution of the plasticizer on the polyvinyl chloride particles is obtained. The aqueous suspensions or emulsions obtained in the suspension or emulsion polymerization of vinyl chloride in which the plasticizer is in the desired ratio to the polyvinyl chloride in a known manner, for. B. has suspended or emulsified by stirring with or without the use of an emulsifier, such as alkyl sulfonates or alkali salts of acidic alkyl sulfuric acid esters. With an emulsifier content of about 2.5%, in an emulsion of polyvinyl chloride obtained by emulsion polymerization, for. B. easily emulsify up to 40% plasticizer. However, suspensions or emulsions which have been produced from finely divided plasticizer-free polyvinyl chloride powder can also be used with the same success. To carry out the process according to the invention, which can be applied to polyvinyl chloride of any degree of polymerization, all liquid plasticizers commonly used for polyvinyl chloride, e.g. B. dioctyl phthalate, dibutyl phthalate, higher esters of adipic acid, the process for production

of finely divided plasticizer-containing

Polyvinyl chloride powder

Applicant:

Chemical works Hüls Aktiengesellschaft, Marl (Kr.Recklinghausen)

Dr. Karl Weißbach, Marl (Kr. Recklinghausen), has been named as the inventor

Sebacic acid, tricresyl phosphate. You can use any amount, for example up to 40%, with the Polyvinyl chloride are mixed.

The subsequent treatment with a hot air or inert gas stream after spray drying, which has a temperature of about 140 to 200 ° C, is obtained from the spray drying more or less sticky polyvinyl chloride is a free-flowing powder.

example 1

20% dioctyl phthalate (based on the solids content of polyvinyl chloride) is stirred into a polyvinyl chloride emulsion obtained by the emulsion process with about 48% polyvinyl chloride with a K value of 70 and about 2.5% sodium alkyl sulfonate as an emulsifier and this mixture is atomized into hot air using a spray-drying system of about 140 ° C. The dry material, which is a snow-white, somewhat sticky powder, is introduced into a vertical tube 100 cm in diameter and 1200 cm in height, ^{which is subjected to a stream of hot air (300 Nm 3} per hour) at 170 ° C. Already after a dwell time of 4 seconds with two passes, the individual particles are almost completely gelled, and the filter material obtained is a finely divided, plasticizer-containing polyvinyl chloride which is ideally free-flowing.

Example 2

The polyvinyl chloride emulsion described in Example 1 is used 40% dioctyl phthalate is obtained by spraying the mixture at

209 618/345

140 ° C, a more sticky polyvinyl chloride, which also results in a finely divided, free-flowing powder at the post-treatment with a hot air current of 170 ⁰ C.

Claims (1)

PATENT CLAIM: Process for the production of finely divided, plasticized polyvinyl chloride powder, characterized in that aqueous suspensions or emulsions containing polyvinyl chloride and liquid plasticizers are subjected to spray drying at temperatures of 110 to 180 ° C. and the spray drying is followed by treatment of the polyvinyl chloride with hot air - or an inert gas stream with temperatures of 140 to 200 ° C follows. Considered publications:
German Patent No. 749 509;
U.S. Patent No. 2,530,852. © 209 618/345 6.62