Use of polyolefin waxes in the field of plastics processing
The invention relates to the use of polyolefin waxes as external lubricants and release agents for plastics. Said polyolefin waxes are produced by using metallocene catalysts, whereby the polyolefin waxes are homopolymerizates of ethylene or are copolymerizates of ethylene with one or more 1-olefins, and linear or branched, substituted or non-substituted olefins having 3–18 C atoms are used as 1-olefins. The processable plastic mixtures produced in this manner have a distinctively longer tack-free time and exhibit an improved behavior with regard to mold release.
1. A method for forming a plastic comprising the step of adding a lubricant to the plastic, wherein the lubricant is at least one polyolefin wax prepared by means of metallocene catalysts, where the at least one polyolefin wax is an ethylene homopolymer wax or an ethylene copolymer wax with one or more 1-olefins which may be linear or branched, substituted or unsubstituted and have 3–18 carbon atoms, wherein the lubricant is present in an amount from 0.1 to 0.3% by weight and wherein the plastic is selected from the group consisting of polyamides, polypropylene and polyvinyl chloride.
2. The method as claimed in claim 1 , wherein the ethylene copolymer wax contains 0.1–30% by weight of one or more 1-olefins having a chain length of from 3 to 18 carbon atoms.
3. The method as claimed in claim 1 , wherein the 1-olefins have a chain length of from 3 to 6 carbon atoms.
4. The method as claimed in claim 2 , wherein the ethylene copolymer wax contains 0.1–30% by weight of propene or 1-butene.
5. The method as claimed in claim 1 wherein the at least one polyolefin wax has a dropping point in the range from 90 to 130° C. and a melt viscosity at 140° C. in the range from 10 to 10,000 mPa s.
6. The method as claimed in claim 1 , wherein the at least one polyolefin wax has been modified in a polar manner.
7. The method as claimed in claim 1 , wherein the at least one polyolefin wax has been micronized.
8. A plastic article made in accordance with the method of claim 1 .
9. A method for forming a plastic comprising the step of adding a release agent to the plastic, wherein the release agent is at least one polyolefin wax prepared by means of metallocene catalysts, where the at least one polyolefin wax is an ethylene homopolymer wax or an ethylene copolymer wax with one or more 1-olefins which may be linear or branched, substituted or unsubstituted and have 3–18 carbon atoms, wherein the release agent is present in an amount from 0.1 to 0.3% by weight and wherein the plastic is selected from the group consisting of polyamides, polypropylene and polyvinyl chloride.
10. The method as claimed in claim 9 , wherein the ethylene copolymer wax contains 0.1–30% by weight of one or more 1-olefins having a chain length of from 3 to 18 carbon atoms.
11. The method as claimed in claim 9 , wherein the 1-olefins have a chain length of from 3 to 6 carbon atoms.
12. The method as claimed in claim 10 , wherein the ethylene copolymer wax contains 0.1–30% by weight of propene or 1-butane.
13. The method as claimed in claim 9 , wherein the at least one polyolefin wax has a dropping point in the range from 90 to 130° C. and a melt viscosity at 140° C. in the range from 10 to 10,000 mPa s.
14. The method as claimed in claim 9 , wherein the at least one polyolefin wax has been modified in a polar manner.
15. The method as claimed in claim 9 , wherein the at least one polyolefin wax has been micronized.
16. A plastic article made in accordance with the method of claim 9 .