The present invention relates to phosphorus compounds as stabilizers for polymers with respect to exposure to heat or mechanical stress during processing.
The prior art describes many phosphorus compounds which can be used to stabilize polymeric compounds during processing (see, for example, “Kunststoff-Additive” [Plastics additives]—Gächter and Müller, 3rd Edn., 1990). Mention may be made here in particular of the phosphite and phosphonite classes of compounds, whose use extends to the industrial scale. These stabilizers reduce damage to the polymer through exposure to heat or mechanical stress during processing.
A disadvantage of these compounds is relatively pronounced susceptibility to hydrolysis and the need to use amounts in the range above 500 ppm in order to achieve sufficient stabilizing action. The precise amounts used naturally depend on the application sector envisaged and on the polymer type, and always have to be determined in suitable trials.
Another group of compounds suitable in principle is that of the phosphanes, which unlike the phosphites and phosphonites contain no hydrolysable P—O bonds. No hydrolysis can therefore occur with these compounds. Nevertheless, this class of compound is not in practice used on any commercial scale. However, the patent literature has references to their suitability as stabilizers (e.g. U.S. Pat. No. 3,637,907, U.S. Pat. No. 2,981,716). From the examples given in those references it is possible to see that the concentration range used for the compounds which they describe is the same as that for conventional stabilizers. It is possible to conclude that the structure here gives no substantial advantage in effectiveness over the stabilizers used hitherto.
U.S. Pat. No. 5,852,138 disclsoses stabilizer mixtures and their use in polycarbonates, wherein the stabilzer mixtures comprise the combination of phosphines and silicon compounds. In the examples 1,2-bis-(diphenylphoshino)ethane and 1,4-bis-(diphenylphoshino)butane are applied in 1:4 mixtures with silanes in polycarbonate at a concentration of 0.2 wt %
U.S. Pat. No. 5,627,256 discloses polycarbonates containing aryl phosphines. In the examples 1,2-bis-(diphenylphoshino)ethane and 1,4-bis-(diphenylphoshino)butane are applied in polycarbonate at a concentration of 0.1 wt %.
U.S. Pat. No. 3,637,907 discloses polyolefins stabilized with diphosphines. In column 2, line 8–11 it is stated that “the amount of the alkylene diphosphine necessary to provide effective stabilization is between about 0.1 and 3 pounds of the phosphine per 100 pounds of the polyolefin to which the phosphine is added. In Example 1 of D3 an amount of 0.13 wt % of ethylene bis(diphenylphosphine) is applied in polypropylene, whereas in example 2 of D3 an amount of 0.1 wt % of ethylene bis(diphenylphosphine) is applied in polypropylene.
U.S. Pat. No. 5,488,079 discloses the stabilization of polyolefins with phosphines which are preferably applied in amounts of 0.02 to 1 wt %. In example 6 tris-(4-methyl-phenyl)phosphine is applied in PP in an amount of 0.04 wt %, whereas in example 7 tris-(4-methyl-phenyl)phosphine is applied in PP in an amount of 0.07 wt %.
Surprisingly, it has now been found that compositions which comprise one or more polymers, in particular polyolefins (component a)) and one or more compounds of the formulae (I) to (IV) (component b)) have significantly high stability, even when the concentration range for b) is very low. The criterion for stabilizing action is the maintenance of the initial molecular weight of the polymer in the melt after the polymer has been processed and, respectively, the technical determination of the same by measuring the melt flow index (MFI) and/or measuring the discoloration arising as a result of processing.
On the basis of the experiments carried out it can be assumed that sufficient stabilizing action can be achieved even in the range from 5 to 500 ppm, preferably from 10 to 400 ppm, and in particular from 25 to 350 ppm, based in each case on component a).
The invention therefore provides compositions comprising as component a) one or more polymers and as component b) one or more compounds of the formula (I)
where, independently of one another
Preference is given to compounds of the formula (I) where
Particular preference is given to compounds of the formula (I) where
The compounds
are of very particular importance.
The compounds of the formulae (I) to (IV) may be prepared from known compounds with the aid of known processes. An overview of these preparation processes is given by way of example in G. M. Kosolapoff, Organic Phosphorus Compounds, Volume 1–7, Wiley, New York, 1972 or Houben/Weyl, Methoden der Organischen Chemie [Methods of organic chemistry], Volume 12, 4th Edition, Georg Thieme Verlag, Stuttgart 1963 and the appropriate supplementary volumes. The contents of these are incorporated herein by way of reference.
These compounds are characteristically prepared from organohalogen compounds, such as alkyl or aryl chlorides or alkyl or aryl bromides and PCl3 using a Grignard or modified Wurtz reaction, using a Friedel-Crafts reaction, by adding a P—H-containing compound to multiple bonds, by alkylating or arylating P—H compounds, using the Arbuzov reaction of diorganophosphonites with organohalides, followed by reduction steps, or by derivatizing previously formed phosphanes.
The amount of component b) present in the composition is preferably from 5 to 500 ppm, with preference from 10 to 400 ppm, and in particular from 25 to 350 ppm, based in each case on the weight of the polymer a).
Other additives which may be added to a polymeric formulation of the invention encompass antioxidants, such as sterically hindered phenols, secondary aromatic amines or thioethers (as described in “Kunststoff-Additive” [Plastics additives]—Gächter and Müller, 3rd Edn., 1990, p. 42–50, the content of which is incorporated herein by way of reference); acid scavengers such as sodium stearate, magnesium stearate, zinc stearate and calcium stearate, and sodium lactate, magnesium lactate, zinc lactate and calcium lactate, hydrotalcites or alkoxylated amines; UV stabilizers, and also other sterically hindered amines (such as N-unsubstituted, N-alkyl, N—O-alkyl or N-acyl substituted 2,2,6,6-tetramethylpiperidine compounds) [also known as hindered amine light stabilizers (HALSs)] and UV absorbers (such as 2-(2′-hydroxy-phenyl)benzotriazoles, 2-hydroxybenzophenones, (2-hydroxyphenyl)triazines, 1,3-bis(2′-hydroxybenzoyl)benzosalicylates and -cinnamates and oxamides), UV quenchers, such as nickel complexes, benzoates and substituted benzoates, antistats, flame retardants, lubricants, plasticizers, nucleating agents, metal deactivators, biocides, impact modifiers, fillers, pigments and fungicides.
Component b) may be added to the polymeric material a) prior to, during or following the preparation process, and the addition may use a solid or molten form or a solution or suspension, preferably a liquid concentrate comprising from 10 to 80% by weight of component b) and from 90 to 20% by weight of the solvent, or a solid concentrate composition (masterbatch) comprising from 10 to 80% by weight (in particular from 40 to 70% by weight) of component b) and from 90 to 20% by weight (in particular from 60 to 30% by weight) of a solid polymeric material which is identical or compatible with the material to be stabilized.
Component b) may, moreover, be in the form of mixtures with other additives, e.g. those mentioned above, when it is introduced as described into the polymer. These mixtures, also termed blends, may be prepared by mixing the powders, compacting, extrusion or melt pelletization or a similar method.
Polymeric materials encompass products which can be prepared from monomeric units by polymerization, polycondensation or polyaddition. Examples of these polymers a) are polyolefins (polyethylenes (HDPE, LDPE, LLDPE, VLDPE, etc.), polypropylene, polybutylene, COC etc. and copolymers of these), polystyrene, polyurethanes, polyester (e.g. PET, PBT, PBN, etc.), polyamides and polyacetals. Copolymers of these individual polymers are also included, as are blends of various polymers (e.g. ABS, SAN, etc.).
The examples below illustrate the invention.
A polymeric composition comprising
A polymeric composition is prepared by the method of Example 1 except that instead of 0.005 part, 0.01 part of bis(diphenylphosphino)-2-2-dimethylpropane is used.
A polymeric composition is prepared by the method of Example 1 except that instead of 0.005 part, 0.02 part of bis(diphenylphosphino)-2-2-dimethylpropane is used.
A polymeric composition is prepared by the method of Example 1 except that instead of 0.005 part, 0.04 part of bis(diphenylphosphino)-2-2-dimethylpropane is used.
A polymeric composition is prepared by the method of Example 1, except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.005 part of 1,1,1-tris(diphenylphosphinomethyl)propane (compound (III)) is used.
A polymeric composition is prepared by the method of Example 1, except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.01 part of 1,1,1-tris(diphenylphosphinomethyl)propane (compound (III)) is used.
A polymeric composition is prepared by the method of Example 1, except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.02 part of 1,1,1-tris(diphenylphosphinomethyl)propane (compound (III)) is used.
A polymeric composition is prepared by the method of Example 1, except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.04 part of 1,1,1-tris(diphenylphosphinomethyl)propane (compound (III)) is used.
A polymeric composition is prepared using the method of Example 1 except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.005 part of Sandostab P-EPQ® (producer: Clariant AG) is used.
A polymeric composition is prepared using the method of Example 1 except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.01 part of Sandostab P-EPQ® (producer: Clariant AG) is used.
A polymeric composition is prepared using the method of Example 1 except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.02 part of Sandostab P-EPQ® (producer: Clariant AG) is used.
A polymeric composition is prepared using the method of Example 1 except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.04 part of Sandostab P-EPQ® (producer: Clariant AG) is used.
A polymeric composition is prepared by the method of Example 1, except that no phosphane or Sandostab P-EPQ® was used.
The following conclusions can be drawn from these results of Examples 1 to 13:
A polymeric composition comprising
A polymeric composition is prepared by the method of Example 14 except that instead of 0.005 part, 0.01 part of bis(diphenylphosphino)-2-2-dimethylpropane is used.
A polymeric composition is prepared by the method of Example 14 except that instead of 0.005 part, 0.02 part of bis(diphenylphosphino)-2-2-dimethylpropane is used.
A polymeric composition is prepared by the method of Example 14 except that instead of 0.005 part, 0.04 part of bis(diphenylphosphino)-2-2-dimethylpropane is used.
A polymeric composition is prepared using the method of Example 14 except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.005 part of Sandostab P-EPQ® (producer: Clariant AG) is used.
A polymeric composition is prepared using the method of Example 14 except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.01 part of Sandostab P-EPQ® (producer: Clariant AG) is used.
A polymeric composition is prepared using the method of Example 14 except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.02 part of Sandostab P-EPQ® (producer: Clariant AG) is used.
A polymeric composition is prepared using the method of Example 14 except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.04 part of Sandostab P-EPQ® (producer: Clariant AG) is used.
A polymeric composition is prepared by the method of Example 14, except that no phosphane or Sandostab P-EPQ® was used.
The following conclusions may be drawn from these results of Examples 14 to 22:
A polymeric composition comprising
A polymeric composition is prepared by the method of Example 23 except that instead of 0.005 part, 0.01 part of bis(diphenylphosphino)-2-2-dimethylpropane is used.
A polymeric composition is prepared by the method of Example 23 except that instead of 0.005 part, 0.02 part of bis(diphenylphosphino)-2-2-dimethylpropane is used.
A polymeric composition is prepared by the method of Example 23 except that instead of 0.005 part, 0.04 part of bis(diphenylphosphino)-2-2-dimethylpropane is used.
A polymeric composition is prepared using the method of Example 23 except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.005 part of Sandostab P-EPQ® (producer: Clariant AG) is used.
A polymeric composition is prepared using the method of Example 23 except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.01 part of Sandostab P-EPQ® (producer: Clariant AG) is used.
A polymeric composition is prepared using the method of Example 23 except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.02 part of Sandostab P-EPQ® (producer: Clariant AG) is used.
A polymeric composition is prepared using the method of Example 23 except that instead of 0.005 part of bis(diphenylphosphino)-2,2-dimethylpropane 0.04 part of Sandostab P-EPQ® (producer: Clariant AG) is used.
A polymeric composition is prepared by the method of Example 23, except that no phosphane or Sandostab P-EPQ® was used.
The following conclusions may be drawn from these results of Examples 23 to 31:
Number | Date | Country | Kind |
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1122/01 | Jun 2001 | CH | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB02/02308 | 6/17/2002 | WO | 00 | 12/12/2003 |
Publishing Document | Publishing Date | Country | Kind |
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WO02/102886 | 12/27/2002 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
2981716 | Street et al. | Apr 1961 | A |
3637907 | Mathis et al. | Jan 1972 | A |
5488079 | Staniek | Jan 1996 | A |
5627256 | Meier et al. | May 1997 | A |
5852138 | Meier et al. | Dec 1998 | A |
5969014 | Webster et al. | Oct 1999 | A |
5986098 | Staniek | Nov 1999 | A |
6103796 | Staniek et al. | Aug 2000 | A |
6369140 | Staniek | Apr 2002 | B1 |
20030020048 | Krohnke et al. | Jan 2003 | A1 |
Number | Date | Country |
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19961464 | Jun 2001 | DE |
WO 0206390 | Jan 2002 | WO |
Number | Date | Country | |
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20040171723 A1 | Sep 2004 | US |