CS256709B1 - Stabilization mixture for polyvinyl chloride - Google Patents

Abstract

The solution relates to a stabilization system for polyvinyl chloride suitable for technical purposes. According to the solution, the stabilization mixture contains 0.5 parts by weight of tribasic lead sulfate, 2 to 6 parts by weight of calcium oxide, 1 part by weight of stearic acid and 0.5 parts by weight of phthalic acid-based wax with a saponification number of 140 to 160, a pouring point of 76 to 81 °C and a solidification point of 70 to 74 °C. The stabilization mixture may also contain 1 part by weight of calcium stearate.

Description

256709

The invention relates to a stabilizing mixture of polyvinyl chloride suitable for technical purposes. Nowadays, industrially produced polyvinyl chloride (PVC) cannot be processed without effective stabilizing systems, since it is deprived of its effectiveness. The main requirements for a quality stabilization system are: high thermal stability, at least a color change in the heat stress of the stabilized polymer, satisfactory mechanical properties of the products, availability of stabilizing system components on the domestic market and their relatively low cost .

For technical purposes, one of the main components of stabilizing compositions is currently the lead tribasic sulfate stabilizer (NS 5012). It is industrially used in 4 parts per 100 parts PVC and these samples exhibit high thermal stability values of up to 150 min. and faulty changes of the film monitored on stabilizer PVV 03 at 180 ° C observed after 60 minutes. The disadvantage of this stabilizer is its carcinogenicity and the economic desirability of having foreign exchange cover for it, which adversely affects the cost of the stabilization mixture.

The above-mentioned disadvantages are largely solved by the stabilizing composition according to the invention, which consists in that it contains 0.5 wt. of tribasic lead sulfate, 2 to 6 wt. parts of calcium oxide, 1 wt. parts of stearic acid and 0.5 wt. a wax-based wax-based wax having a saponification number of 140 to 160, a melting point of 76 to 81 ° C and a freezing point of 70 to 74 centipoise.

The mixture of the invention may also contain 1 wt. Polyvinyl chloride samples stabilized with this stabilizing mixture retain high thermal stability and color stability over thermal stress at 180 ° C. The reduction in the amount of tribasic lead sulfate in the stabilizing mixture is of great importance in terms of health. and it means saving foreign currency for the national economy.

The invention is illustrated by the following examples: EXAMPLE 1 100 wt. parts of suspension polyvinyl chloride (Slovinyl S-621) are mixed with 0.5 wt. violet wax-based wax (HOECHST-WACHSE E wax is a montanic acid ester wax, with a freezing point of 70 to 74 ° C, a saponification number of 140 to 160, an acid number of 15 to 20, a drop of 76 to 81 ° C and density at 20%: 1.01 to 1.03 gm -3), 0.5 wt. stearic acid and 4 wt. parts of CaO food]. The whole mixture is calendered at 180 ° C for 3 minutes to form a 0.15 mm thick film. The sample from the obtained foil is thermally degraded at 180 ° C in the air. According to ČSN 640751 the thermal stability time was 128 minutes. The color changes reported on PVC 03 were detectable at 180 ° C for 30 minutes and at 170 ° C for 60 minutes. Example 2

The sample is prepared similarly to Example 1 with the composition: 100 wt. parts of polyvinyl chloride (S-621), 0.5 wt. waxy violet base (physico-chemical characteristics as in Example 1), 0.5 wt. of tribasic lead sulfate (NS 5012), 1 wt. part of stearic acid and 6 wt. parts of CaO. The mixture was calendered for 3 minutes at 180 ° C to give a 0.15 mm film. Under the same experimental conditions, a thermal stability value of 190 minutes, a color stability of 180 ° C for 50 minutes and a temperature of 170 ° C for 80 minutes were found. Example 3

The sample is prepared similar to Example 1 with the composition: 100 wt. parts of polyvinyl chloride (S-621), 0.5 wt. Wax works are violet (physico-chemical characteristics as in Example 1), 0.5 wt. NS 5012, 1 wt. part stearic acid, 3 wt. parts of CaO, 1 wt. part stearate calcium. The calendering time at 180 ° C was 3 minutes and the film thickness was 0.15 mm. The thermal stability of 130 minutes, the color stability at 170 ° C is 80 minutes and at 180 ° C it is 64 minutes. Example 4

A sample was prepared similar to Example 1 with the composition: 100 wt. parts of polyvinyl chloride (S-621), 0.5 wt. violet wax-based waxes (physico-chemical characteristics as in Example 1), 0.5 wt. of tribasic lead sulfate (NS 5012), 1 wt. part of stearic acid, 2 wt. parts of CaO, 1 wt. part stearate. The calendering time at 180 ° C is 3 minutes and the film thickness is 0.15 mm. The thermostability is 115 minutes, the color stability at 180 ° C is 30 and at 170 ° C it is 90 minutes.

Claims (2)

SUBJECT A stabilizing composition for polyvinyl chloride suitable for technical purposes, characterized in that it contains 0.5 wt. parts of tribasic lead sulfate, 2 to 6 wt. parts by weight of calcium oxide, 1 wt. % of stearic acid and 0.5 wt. work based wax kyseVYNALEZU Tench phthalic saponification number of 140-160, a melting skvapuutia 76 to 81 ° ^C and pour point 70-74 C. ^C 2. A stabilizing mixture for polyvinyl chloride according to claim 1, characterized in that it comprises 1 wt. % of calcium stearate.