CS243560B1 - Method of waste material stabilization from polypropyle fibres preparation - Google Patents

Abstract

The method of stabilization is that k waste material either cut with advantageously pre-washed and centrifuged, or agglomerated or crushed, or regranulated, either cable with a melt index of 3.5 to 17, p preferably 3.5 to 11 g / 10 min or staple with a melt index of 5 to 70, preferably 6 to 25 g / 10 min for use as a secondary raw material is used as a stabilizer a compound of formula ABOUT ABOUT RO - p r-0 '-0 P-OR WITH / wherein R is as described herein. The stabilizer is added at 0.04 up to 1.2, preferably 0.1 to 0.4% by weight. In addition to the subject features listed There are other possible variants of the invention. The invention can be used in the production of polypropylene fibers.

Description

(54) Method of stabilizing waste material from the preparation of polypropylene fibers

2

The stabilization method consists in adding to the waste material either cut, preferably pre-washed and centrifuged, or agglomerated, or crushed, or regranulated, either with a cable having a melt index of 3.5 to 17, preferably 3.5 to 11 g / 10 min. or staple with a melt index of 5 to 70, preferably up to 25 g / 10 min for its use as secondary raw material, a compound of the formula

RO - p

r-0 '-0

P-OR wherein R is as described herein.

The stabilizer is added in an amount of 0.04 to 1.2%, preferably 0.1 to 0.4% by weight. In addition to the above features of the invention, there are other possible variants.

The invention is applicable to the production of polypropylene fibers.

The invention solves the use of aralkylphenylphosphites and mixed pentaerythritol-based phosphites as multifunctional stabilizers in the preparation of polypropylene fibers from their wastes, which may be hard (from compact to stringed), soft stringed, undetected and partially drawn.

The spinning waste has the following disadvantages:

When the polymer is recovered from the waste by melting without the use of stabilizers, fibers with impaired long-term thermal, process and light stability, strength, ductility and dispersing properties are prepared.

The non-weighed fibers produced from the waste thus prepared are more than doubled: twice for the preparation of fibers - in conventional production and from waste; in addition for recycling - either crushing hard and stringed waste or agglomeration and regranulation of unstretched and shallow stringed waste.

As a result of the reaction mechanism with oxygen and the high temperatures, friction, durability and other conditions of the processing and use of waste fibers, the content of stabilizers used decreases more than conventional fibers. For undrawn and partially debrised fibrous wastes, preparation from the fiber surface proceeds to a certain degree upon remelting in the polymer volume. It is known that some components (especially silicone formulations) impair the dispersion of pigments even when they are in small amounts in polypropylene, and therefore the waste can be used as a raw material for fiber preparation with some risk.

The literature, including the patent, lacks data on the multifunctional deposition of organic phosphite stabilizers to improve the properties of the secondary raw material, which has been impaired during fiber production and waste recycling. It is the multifunctional action of additives that is practically important for the desired improvement of the complete set of properties in polymer systems with a deteriorated prehistory, such as waste. The present invention achieves an improvement in long-term thermal and processing stability as well as dispersing properties.

This procedure for the use of additives consists of the following. For waste either crushed (hard-compact and string-like), or cut, preferably pre-spun and centrifuged or even agglomerated (unstretched, partially drawn and softly string-like) or regranulated, either with a cable with a melt index of 3.5 to 17, preferably 3 , 5 to 11 g / 10 min, or a staple fiber with a melt index of 5 to 70, preferably 6 to 25 g / 10 min, a compound of the formula I is used as a stabilizer.

RO-P '* Y OR _Z-0- P ^ ^x -O where R is H or represents a trisubstituted phenyl group of formula

where

R 1 is methyl, tert-butyl, 1,1'-dimethylbenzyl or cyclohexyl

R @ 2 is hydrogen, methyl, tert-butyl or 1,1'-dimethylbenzyl;

R 3 is hydrogen, methyl, isopropyl or cyclohexyl in an amount of 0.04 to 1.2, preferably 0.1 to 0.4% by weight, preferably 4,9-di [2-tert-butyl-4- (1,1'-Dimethylbenzylphenoxy) -3,5,8,10-tetraoxa-4,9-diphosphiro [5,5] hendecane.

The stabilizer may, in addition to the usual state, also be in the form of 1 to 30, preferably 5 to 15% by weight in the masterbatch of the polymer, preferably powdered or regranulated. The waste with added stabilizer is used as raw material in this state or is remelted in a melter at 170-310, preferably 175-230 ° C, and filtered through a filter with 80-1,600 or more holes per cm ² .

The regranulate or agglomerate or pulp can be used either as a 100% raw material without the use (or only for the doping) of the pigment for fiber preparation or in a mixture: with each other, with finely cut fiber waste, with common raw materials . Optionally, a finely cut, non-crosslinked fiber may be used which is mixed with the color concentrates and the stabilizer is added with stirring. In this case, it is suitable to homogenize the polymeric raw material from the waste in a conical mixer or other suitable device for 8 to 50 minutes before remelting and spinning.

If an unstable polymeric feedstock is used, it is also possible to add a stabilizer during spinning. The thus-homogenized melange, preferably mono-shade feedstock is melted in the basic melt screw at temperatures of 190 to 390 ° C or at the same time in the side screw at these heat243560 t. It is fiberized at temperatures of 200 to 330, preferably 210 to 230 ° C. The weaning time of the uninitiated fiber is 1 to 60 h. The fiber is then rinsed at a speed of 70 to 1,800, preferably 100 to 1,400 m / min and a ratio of 1: 2 to 1: 1.5, preferably 1: 2.8. to 1: 3.5.

As a further possibility, the waste in the form of either agglomerate or regranulate or pulp or finely cut from fibers or a mixture of these forms is added to each other in an amount of up to 40, preferably up to 5% polymer-based and mixed in a conical mixer. , preferably 20 to 30 minutes, optionally in another suitable mixing device with either the float polypropylene or the pigment concentrate, or part of the above amount is mixed with the polymer and another part with the pigment concentrate.

The content of the added polypropylene as well as the pigment in the batch decreases in proportion to the added polymer and the pigment in the form of waste. In addition to the waste, the stabilizers according to Table 1 can be added, either in the normal state or in the form 1 to 30. preferably 5 to 15% by weight of a stabilizer in the masterbatch of either a polymer, preferably powdered or regranulated.

The homogenized melange, preferably mono-shade feedstock is melted either in the basic melt screw at temperatures of 190 to 390 ° C, or in the side - at 200 to 380 ° C, or simultaneously in both screws at these temperatures. The spinning, decommissioning and quenching take place under the above conditions as with 100% w / w waste material.

The economic advantage of the proposed use of organic phosphite stabilizers is that, in the production of polypropylene fibers, wastes while improving several of the required properties are utilized separately or in small quantities as polymer raw material, colored or possibly tinted to a final color shade. This saves polypropylene and expensive pigments. The stabilizers used in the present invention do not stain the polymer and have low volatility.

Furthermore, the stabilizer C used in an amount of 0.25% (Table 1) is cheaper than the stabilizer used in waste treatment in the author's certificate No. 197 657 of 07.12.

1981 and No. 198,682 of April 15, 1982.

Further advantages in this process of using the stabilizers listed in Table 1 appear to be lower temperatures of 5 to 110 ° C in the hot melt screws compared to conventional production and improved operational reliability of spinning and dredging and thus the possibility of waste reduction. Example

Waste from the production of cable fibers was used to assess efficiency. These fibers are made by spinning polypropylene under the trade mark Tiplen H531F. The polypropylene cable produced contained 1.2728% by weight of pigments under the trademark Cromophtal gelb GR (1.0177% by weight), Cromophtal rot BR (0.1767% by weight), Nylophil schwarz BLN (0.0784% by weight).

Said waste with moisture and other volatiles was centrifuged to a moisture content of 1.73 to 2.47%, cut and then evenly sprayed with the amounts of individual and stabilizer mixtures listed in Table 1. This was followed by remelting at temperatures of 220 to 260 ° C and a melting time of 2 to 2.5 minutes in a fusing mono with a diameter of 80 to 125 millimeters and filtering through a filter with 624 holes per cm ² .

A portion of the prepared regranulate containing 0.25% C (Table 1) was remelted and a second regranulate was obtained at temperatures of 170 to 240 ° C, a melting time of 80 to 100 and a rotation speed of 280 rpm in a melting bipolar of 53 mm and filtering through a filter with 1600 holes per cm ² . The regranulates of all samples of Table 1 were homogenized in a food mixer over 10 min. The homogenized individual samples were melted in an extruder with a screw diameter of 90 mm and spun.

The melting and spinning conditions were: 240 ° C melting zone temperature, 260 ° C spinning temperature, 7 MPa pre-pump pressure, 9 MPa downstream pump, 15 to 20 min melting time, 300 g / min single spinning station, 435 spinning speed m / min, number of Y-holes in the nozzle 100, diameter of the nozzle hole cross-section 0.346 mm, nozzle capillary length 2 mm.

The melt indices were determined on a Gottfert plastomer according to standard. The degree of dispersion and maximum agglomeration were evaluated microscopically, similar to that described in the Catalog of Analytical-Physical Methods, published by the Research Institute of Chemical Fibers in Svit, 1977, pp. 79-82. Other determinations were made according to conventional methodologies.

After standing, the undiluted fiber was stretched at a mean spill speed of 280 m / min at a ratio of 1: 3.154. The temperature of the lower galet was 112 ° C and the upper galet was 117 ° C. The efficacy of small amounts of stabilizers alone and their combination in waste was monitored. The values obtained were compared with the values, in particular waste without addition (Oj.

It can be seen from Table 1 that by adding small amounts of individual and stabilizer mixtures, several properties of the polypropylene fibers are improved at the same time, unlike sample O. The addition of 0.25% C wastes to the feedstock and the regranulation and spinning processing steps is observed. higher thermal stability of the waste polymer considering the reduced degradability index and / or the degradation index, respectively the melt index, under the die compared to the other samples (Table 1) as well as the flood raw material (Table 2). The melt index at 230 ° C, the cutoff below the die, is the lowest and the limit viscosity number of the non-runnable fiber is highest when the stabilizer is treated with 0.25 ° / o C in the waste polymeric material compared to the other samples and in particular with sample O (Table 1j).

Improvement of degradation index and degradation index on the spinneret (Table 1) after a long remelting time (2 to 2.5 min in a 80-125 mm diameter melt screw + 15 to 20 min in a 90 mm worm diameter extruder 15 min (degradation of the sample in the plastomer (--4 min to determine the melt index of the degraded sample)) indicates an increased long-term thermal and process stability with a 0.25% C effect. The increased long-term thermal stability of the waste polymeric material enables color changes to be avoided.

Thus, the 0.25% C stabilizer has a greater effect on increasing the long-term thermal and processing stability (at the regranulation and spinning stages) of the polypropylene fibers prepared from their wastes compared to the 0.25% A stabilizer, the effect of which has been reported in CSSR AO No. 197,657 and AO No. 198,682.

The above small amounts of reagents will work over a wide temperature range - from ordinary temperatures at which dispersion and maximum agglomeration are determined to degradation index temperatures of 280 ° C and above (Table 1j.

It can be seen from Table 1 that by adding small amounts of said stabilizers, an improvement in the new set of properties of the polymeric raw material from the waste and its fibers compared to the waste without additions is obtained at the same time.

Furthermore, with the aforementioned stabilizers, there is the possibility of increasing the quality of some concentrates to some extent, improving the recoverability, abrasion, compressibility, workability of difficult-to-use shades, including pale and reducing the number of streaks and wastes. raw materials.

To improve in particular the light fastness of the wastes instead of the above stabilizers and in their presence either 0.03 to 0.3% 2-hydroxy-4-n-octyloxybenzophenone or 0.03 to 0.3% 2- (2) may be added. '-hydroxy-3', 5'-di-tert-butylphenyl; -5-chlorobenzotriazole or other substituted hydroxybenzothiazoles or spherically hindered amines and organic Ni complexes.

Shavings under the nozzle

Melting index Index to Index at 230 ° C, degradation, degradability g / 10 min g / 10 min Bulk 1

Undrawn thread

Limit Grade Maximum viscosity dispersions agglomeration, number mkm

Waste without addition (O)

21.77 75.11 3.45 140.00 2.90 51

0,25% tetrakis- (2,4-di-tert-butylphenyl) -4,4‘-biphenylenediphosphonite (A) * j

12.17 41.35 3.40 1.90

0.25% trls (1-phenylethylphenyl) phosphite (B) * j

0.15% A + 0.10% B

12.86 43.25 3.36 144.19 40

0,25% 4,9-di [2-tert-butyl-4- (1,1 ') -dimethylbenzyl) phenoxy] -3,5,8,10-tetraoxa-4,9-diphosphaspiro-4-imidecane ( C) * j

9.64 22.67 2.35 147.86 2.40

0,25% 4,9-di [2-tert-butyl-4- (1,1'-dimethylbenzyl (phenoxy) -3,5,8,10-tetraoxa-4,9-diphosphaspiro- [5,5] '] hendecan (C'j * j')

11.12 26.24 2.36

Explanatory notes:

*) A, B, C, C ‘- abbreviations of the relevant substances **) C‘ - it is substance C, but the regranulate was remelted a second time

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Table 2

Indigenous raw material - waste centrifuged and not cut from unreinforced and partially crumbled fibers

Fusible index at 230 ° C, g / 10min Index after degradation, g / 10 min Index degra- dability Limitně visko- zité number Degree disp- gácie Maxi- málna aglome- rácia, mkm Prepa- race, % Withhold Content Volatile Shares % 10,09 40.46 4.02 169.67 3.55 67 2.76 0.48 1.73

The aforementioned invention is of application importance for optimizing properties in the preparation of processing polymer systems in this issue of polypropylene fibers and plastics products from their various types of waste. The present invention can be used in the manufacture of cable and staple polypropylene fibers from their wastes. The invention has been tested under operating conditions and achieves normal production performance and quality indicators.

Claims (2)

SUBJECT A method of stabilizing waste material from the preparation of polypropylene fibers either cut, preferably prewashed and centrifuged, or agglomerated, or crushed, or regranulated, either cable having a melt index of 3.5 to 17, preferably 3.5 to 11 g / 10 min or staple with a melt index of 5 to 70, preferably 6 to 25 g / 10 min, for its use as a secondary raw material, characterized in that a compound of the formula I is used as a stabilizer O- \ / O \ RO-- Y _{X 0} P ~ _7 OR '-O wherein R is H or represents a trisubstituted formula V Y N ALEZU where it represents R 1 is methyl, tert-butyl, 1,1'-dimethylbenzyl or cyclohexyl R 2 is hydrogen, methyl, tert-butyl or 1,1‘-dimethylbenzyl; R 3 is hydrogen, methyl, isopropyl or cyclohexyl in an amount of 0.04 to 1.2%, preferably 0.1 to 0.4% by weight. 2. A process according to claim 1, wherein the stabilizer used is 4,9-di [2-tert-butyl-4- (1,1'-dimethylbenzyl-phenyloxy) -3,5,8,10-tetraoxa- 4,9-diphosphaspiro [5.5] hendecan.