CS258625B1 - A method of coloring polypropylene fibers in a mass using a thermally low-stability pigment based on monoazopigments - Google Patents

Abstract

Method of dyeing polypropylene fibers in mass using thermally less stable varnishes derived from monoazopigments. The method of dyeing consists in dyeing polypropylene with pre-adjusted melt flow properties with a color pigment dispersion prepared by kneading a mixture containing 0.5 to 30% by mass. pigment with powdered polyolefin modified with the addition of 0.5 to 15% by mass. water-insoluble copolymer of propylene oxide and ethylene oxide, or with the addition of an effective thermostabilizer.

Description

258625

The present invention provides a method for coloring polypropylene fibers using thermally-stable monoazoic lacquers.

The dyeing of polypropylene fibers is carried out by various methods, but mostly by high-concentrated color dispersions, which are metered into the base polymer either by injection in the concentrate melt into the base polymer melt or to the granulated polymer prior to melting. They require high temperatures above the polymer melting temperature in comparison with other polymers in the production of the fibers. Thus, the flow properties of the polymer melt are adjusted so as to be suitable for fiber formation under spinning and post-processing conditions, i.e., stretching and shaping. The higher melting points and the 260-300 ° C melting point also increase the need for pigments in terms of their thermal stability. It goes without saying that such pigments are expensive, the cost of dyeing is high, and the application of fibers due to the inequality of their price and application compared to other synthetic fibers is also narrowed. However, if the flow properties of the polymer are adjusted either by polymerization using a suitable catalyst system or by polymer degradation by polymerization, lower temperatures can be used in the processing to reduce the thermal stability of the pigments. Also, the pigments are cheaper and the cost of dyeing decreases.

Cheaper pigments are usually also more sensitive to temperature, and their shade and color fastness are altered by their thermal stress. This results in fluctuations in the color shade and in the color stability of the processing conditions and the fluctuations in the quality of the other components, especially the polymer.

However, it has been shown that some of the pigment can be treated with suitable additives in the process of dispersing them so that they can be applied with great utility to the stated purpose. Meanwhile, these pigments include strontium lacquer odonoazopigment with Cl P. Red 48: 3.

In its normal application, the color shade is difficult to reproduce. According to the present invention, the pigment can be applied at temperatures up to 250 ° C and the discoloration of demanding products such as polypropylene fibers, if the rheological properties of the polymers have been modified by the process and when the color dispersion is added to the mixture as an additive with water-immiscible propylene oxide copolymer or in combination with a phenol or phosphite-based thermostabilizer.

The rheological properties of the polypropylene melt must be adjusted to index pseudoplasticity n, expressed in relation D == k. τη, (where D - shear rate, k - coefficient, τ - shear stress) was less than 1.5. The conditions for determining the pseudoplasticity index are identical to those of the flow index according to ČSN 640861 by shear stress in the range of 20 to 80 N.

The pseudoplasticity index n is a dimensionless number and expresses the melt flow deviation from Newton's. It is also related to the molecular weight distribution of the polymer. Pseudoplasmic fluids, which also include polypropylene melt, have n> 1. For commercially available polypropylene types, these values are higher than those of polyamides or polyesters and are often above 1.5, which is the polymer of the polymer. reduced workability. The value of k is related to the viscosity of the polymer and takes into account the melt index shown in the following description.

It is possible to process polypropylene on a wide range of fibers (kj by type of fiber).

SUMMARY OF THE INVENTION The present invention relates to a process for coloring polypropylene fibers in a mass using a thermally poorly stable pigment coating of monoazopigens, characterized in that the pre-treated pseudoplasticity polypropylene is below 1.5% of the color pigment dispersion prepared by kneading the blend of 0.5 to 0.5% by weight. 30pere. wt. % of a pigment with a polyolefin powder treated with 0.5 to 15 wt. water-insoluble copolymer-propylene oxide and ethylene oxide, optionally with the addition of an effective thermostabilizer, and other additives. Přikladl

In powdered polypropylene IT 18 g for 10 min. 0.08% 2,5-dimethyl-2,5- (3,5-di-tert-butyl-5-hydroxybenzyl isocyanurate (Goodrite 3 114), 0.2% Chima-sorb 944 was mixed to adjust the flow properties. Nitrogen (tert-butylperoxy) hexane, 0.1% tris-granulated at 200 [deg.] C. The 12 g / 10 min. The polymer pseudoplasty index was 1.47.

For IT 11 g polypropylene powder for 10 min. 7% of ethylene oxide / propylene oxide copolymer was mixed in a high-speed mixer, then 15% of pigment C. I. Pigment Red 48: 3 was added and, after mixing, assembled on a two-spindle extruder, extruded into strings and cut into granules.

The above polymer was melted in extruder at 230 ° C. A melt of said concentrate extruder concentrate was metered into the polymer melt, heated to 230 ° C in a ratio such that the resulting pigment concentration in the fiber was 1%. The tissues were homogenized in the mixer and extruded into fibers.

In the same way, 12 g / 10 min of propylene IT was prepared, prepared by

Claims (1)

SUBJECT Method for dyeing polypropylene fibers with a mass using a thermally unstable monoazopigment lacquer pigment, characterized in that the polypropylene having a pretreated pseudo plasticity index below 1.5 is colored with a color pigment dispersion prepared by kneading a mixture containing 0.5 to 30% by weight. % of pigment with polyolefin powder treated by addition of 0.5 to 15 wt. a water-insoluble copolymer of propylene oxide and ethylene oxide, optionally with the addition of an effective thermostabilizer, and other additives.