CS219652B1 - Polypropylene-based mixture with controllable rheological, stabilizing or orientation and crystalline properties - Google Patents

Abstract

The subject of the invention is a method for improving and regulating the rheological, stabilizing, or orientational properties as well as the crystallinity of polypropylene and its mixtures. This method is characterized in that 0.02 to 0.25%, preferably 0.02 to 0.15%, of poly(ethylene) oxide with a molecular weight of 75,000 to 5,000,000, preferably 100,000 to 900,000, with a broad as well as narrow molecular weight distribution, or a mixture of 0.1 to 0.3% of poly(ethylene) oxide with 0.1 to 0.5%, preferably 0.3 to 0.4% zinc stearate, all concentrations calculated per polymer, is added to the polypropylene during mixing into the polypropylene powder before the pigment concentrates are made, preferably using a turbulent high-speed mixer. After good mechanical mixing of the polypropylene with the above-mentioned agents as well as with pigments, and possibly with other ingredients, the mixture is melted in an extruder and spun. In addition to the above-mentioned features of the subject invention, there are also other possible variants. The present invention can be used for the production of polypropylene fibers or silk, as well as for other shaped products.

Description

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SUMMARY OF THE INVENTION The present invention relates to a polypropylene-based composition with controllable theological, stabilizing or orientation crystalline properties which contains small amounts of poly (ethylene) oxide or a mixture of poly (ethylene) oxide with zinc stearate.

The modification of the rheology of polypropylene as well as its, mixtures with pigments and other ingredients is effective for improving the processability of these polymers. The large number of pigments is based on the flow properties of the melt mainly by increasing its viscosity, i.e. as a braking element, which means that higher temperatures are required to obtain the correct viscosity. In the last 10 "15 years a very limited number of washing machines appeared, which points to the greater or lesser influence of microspheres of some of the individual items called; flowability by melting pure polyolefins. This effect was explained as a result of mutual; | the effect of low molecular weight additions with the polymeric superficial structures of the polymers in the melts. The iPodTa of these washings with the addition of structural elemental pure polyolefins is carried out by dissolving the additive-co-polymer with the following; separating it from the solution, but only hard as a result of mechanical mixing, although mixing is; vial and very intense (G. P. Andrian, N. F. Bakeev, p. V. Kozlov, Vysokomolekuljarnyesoedinenija, 1971, A 13, N ° 2, pp. 266-275). The literature, including the patent, lacks data on the modification and control of two or more properties of the polypropylene, such as melt flowability, thermal stability or orientation and crystallinity in the case of small amounts of added substances such as polyethylene ) oxide and a mixture of poly (ethylene) oxide with stearate; zinc. It is known that of all polyolefin polypropylene, it is least resistant to, oxidation and thermode. In thick-walled products and fibers with coarse titers, often; observe non-uniform structural formations. Pretosa adds modifiers that provide a homogeneous structure in the cross-section of the material under investigation. This texture uniformity is particularly needed at higher titers, whereby only by cooling can a different structure be formed between the surface and the center of the fiber. In the preparation of structurally stable and, to some extent, elastic finished fibers and foils, a compromise is required between the obtaining of a high and constant orientation in which the mobility of the molecules is reduced and the elastic properties where mobility is enhanced are sought. In the meantime, small amounts of poly (ethylene) oxide or mixtures of poly (ethylene) oxide with zinc stearate have not been used to improve and control the rheological, stabilizing or orienting properties as well as the crystallinity of polypropylene. and mixtures thereof with ingredients commonly used in the preparation of fibers and other articles.

The proposed polypropylene-based composition of the present invention is characterized in that per 100? 219652 parts by weight of polypropylene comprise: 0.02 to 0.25 parts, preferably 0.02 to 0.15! poly (ethylene) oxide moieties with a molecular weight of 75,000 to 5,000,000, preferably 100,000 to 900,000 with both broad and narrow molecular weight distributions, or a mixture of 0.1 to 1, 0.3 poly (ethylene) oxide moieties with 0, 1 to 0.5; preferably from about 0.3 to about 0.4 portions of zinc stearate. Poly (ethylene) oxide as well as mixtures thereof; zinc stearate in operating conditions is to be added to the polypropylene powder prior to the formation of the pigment end centers using a turbolent mixer. Furthermore, the addition of an additive is possible either before homogenization in the form of a granular concentrate prepared into polypropylene powder, optionally; as a pure substance or before polymer granulation. 1 Mixing the additive with polypropylene and its mixture is tested in the operating mixing devices under normal conditions. Then: the mixture is melted in the melter and shaped. The melting point is 190 to 415 ° C. Melt indexes were determined on a Gotfert plastomer according to the standard. The thermal stability of polypropylene was assessed from the determined degradability index values. The degree of crystallinity was determined by the flotation method and the orientation by the optical birefringence method.

An advantage of the present invention is the use of additives in small amounts of accessible, inexpensive and non-toxic substances such as poly (ethylene oxide) or a mixture of poly (ethylene) oxide with zinc stearate to improve and control melt flow, thermal stability, optionally, orientation and crystallinity of the polypropylene and its mixtures of application importance. In doing so, the aforementioned small amounts of poly (ethylene) oxide or its mixtures with zinc stearate are capable of acting over a wide temperature range, indicating the effect of their effect. Further changes in melt flow, thermal stability and polymer orientation are rapid! and non-additive to added small amounts of poly (ethylene) oxide. For certain small amounts:; poly (ethylene) oxide in the polypropylene of the present invention results in the mutual cooperation of these components, which is greater than the sum of the actions of the individual substances mentioned above. ! Properties. Therefore, in addition to the action of the interstructural and structural plasticization in the composition of the present invention, the novel synergistic effect of poly (ethylene) oxide with the polymer, optionally with other polymer system components, which in turn increases melt non-additivity and thermal stability is improved. optionally increases orientation and changes crystallinity. The significant increase in melt flowability allows for improved spinning process and product molding at all, extending the temperature range of their processing and especially at the desired lower temperatures. As an additional advantage in the use of poly (ethylene) oxide, it is: reducing the necessary spinning energy. Another advantage of the present invention is the accessible, simple and economical procedure

Claims (2)

i using mechanical mixing and smelting - common working steps in the preparation of fibers and plastic products. In this way, a difficult, uneconomical and unhygienic procedure is avoided in which large amounts of solvent are used to dissolve a large amount of polyolefin for; its good mixing with the reagent followed by polymer precipitation. Therefore, for the others already mentioned Advantages, the mixture of the present invention is technically preferred. EXAMPLE 1 The effectiveness of 600,000 (A) poly (ethylene) oxide alone as well as the combination of (A) with zinc stearate (B) was mixed with powdered non-stabilized polypropylene. Table 1: Table 1 Used additions in ratios of Crystalline Grade in% Degradation Index Melt Index of 230 ° C in g / 10 min AB '0.00 0.0 58.19 3.2 32, 6 0.02 0.0 58.93 2.1 64.3 0.03 0.0 58.93 0.04 0.0 58.93 2.1 0.05 0.0 58.93 1.9 73 , 2 0.06 0.0 60.08 0.08 0.0 61.84 0.10 0.0 61.84 1.9 69.8 0.15 0.0 2.0 68.0 0.20 0.0 64.67 2.1 66.1 0.25 0.0 64.67 2.1 65.3 0.20 0.1 58.93 0.20 0.2 58.93 0.20 0 0 3 56.61 0.20 0.4 56.61 The values obtained were compared with the pure Tatren HPF 411 without the addition of Table 1. Mixing of the mixtures was carried out in a TR-400 turbolent at 600 rpm for 5 min. Mechanical mixing of the mixers with a laboratory mixer over 10 min was also [21965? [ satisfying. The mixed sample was melted in extruder with a screw diameter of 16 mm and plasticized. The melting and spinning conditions were: melting zone temperature and spinning head 240 ° C, pressure up to 8 MPa, downstream pressure 2 MPa, 20 g / µg dispensing, spinning speed of 130 µm / min, number of holes in nozzle 20, hole diameter of 0.3 mm, capillary length of 6 mm. It can be seen from Table 1 that with the effect of small amounts of poly (ethylene) oxide, the flowability of the polymer melt and the thermal stability of the polymer can be greatly increased. polypropylene. At the same time, the greatest increase in the flowability of the polymer melt corresponds to its highest thermal stability. The aforementioned changes in the two properties may be associated with an increase in [, degree of crystallinity, e.g., 0.1 to 0.25 µl of poly (ethylene) oxide moieties and no increase in the degree of crystallinity, e.g. poly (ethylene) oxide. Furthermore, it can be seen that, in addition to small amounts of zinc stearate mixtures. The degree of crystallinity of the polymer may be slightly increased by the amount of poly (ethylene) oxide. The abovementioned amounts of reagents act in a wide range of temperatures - from the normal temperatures at which the crystallinity is determined up to the degradation temperature of the assay, 280 ° C and above - Table 1. Example 2 Similar procedure to Example 1. Difference It is appreciated that the efficiency of micro-poly (ethylene) oxide alone with a molecular weight of 600,000 in various concentrations of granulated and stabilized polypropylene Mosten 55.212 -i 0.2 parts by weight of Bayer R-KB-2 4- 0.2 parts trilauryltritio- phosphite and stirred for 5 min more. Mosten 55.212 was once ground on an Apex mill with a mesh diameter of 1.96 mm. The temperature of the melting zones and the spinning head was 300 ° C. This elevated temperature as well as the presence of trilauryltrithiophosphite required the prepolymerization of polypropylene. The values obtained matched the values of this same mixture of poly (ethylene) oxide - Table 2. Table 2 Poly / ethylene / oxide with a molecular weight of 600,000 in proportions 0.00 0.02 0.05 0.10 0.15 0, 20 0,25 Optical birefringence. 103 1.14 1.26 2.31 3.38 3.21 2.87 2.40 Degradability Index 2.3 2.1 2.1 1.9 1.7 2.0 2.1 The above mixture according to the invention it has application importance for optimizing the properties of the preparation of processing polymer systems even in this number of polypropylene fibers and sheathing products. It can be seen from the table that, depending on the concentration of the poly (ethylene) oxide, the orientation of the aforementioned polymer system may increase slightly, to higher and then to high values. Here, the thermal stability of the polymer is slightly increased. SUBJECT MATERIALS A blend based on polypropylene with regulatable, stabilizing, or opacifiers! and crystalline properties, characterized in that, for 100 parts by weight of polypropylene. and 0.02 to 0.15 aliquots of poly (ethylene) oxide with a molecular weight of 75,000 to 5,000,000, preferably 100,000 to 900,000, with both broad and narrow With a molecular weight distribution of 0.1 to 0.3 parts of poly (ethylene) oxide with 0.1 to 0.5 parts, preferably 0.3 to 0.4 parts of zinc stearate.