Polyolefin composition providing marking by fluorescence
The present invention is directed to a polyolefin composition comprising carbon black which shows fluorescence when irradiated with UV light. The polyolefin composition of the present invention comprises a polyolefin, carbon black in an amount of 0.25 to 1.0 wt %, an optical brightener in an amount of 0.001 to 0.1 wt %, and a UV agent. The present invention is further directed to a molded article comprising the polyolefin composition of the present invention. The present invention is further directed to a wire or cable comprising an outer layer comprising the polyolefin composition of the present invention. Finally, the present invention is directed to a method for detection of a polyolefin composition by UV light and to a method for detection of a molded article or a wire or cable by UV light.
1. A method for detection of a cable by UV light comprising the following steps:
providing a cable,
irradiating the cable with UV light,
detecting fluorescence emitted from the cable,
the cable comprising an outer layer comprising a polyolefin composition comprising:
(A) a polyolefin,
(B) carbon black in an amount of 0.25 to 1.0 wt % based on the weight of the polyolefin composition,
(C) an optical brightener in an amount of 0.001 to 0.1 wt % based on the weight of the polyolefin composition, and
(D) a UV agent.
2. The method according to claim 1 , wherein the outer layer of the cable consists of the polyolefin composition.
3. The method according to claim 1 , wherein the polyolefin is selected from the group consisting of an ethylene homopolymer, an ethylene copolymer, a propylene homopolymer, a propylene copolymer, a blend of an ethylene homopolymer and an ethylene copolymer, and a blend of a propylene homopolymer and a propylene copolymer.
4. The method according to claim 3 , wherein the ethylene copolymer is a copolymer of ethylene and a C 3 -C 12 -alpha-olefin.
5. The method according to claim 3 , wherein the propylene copolymer is a copolymer of propylene and ethylene and/or a C 4 -C 12 -alpha-olefin.
6. The method according to claim 1 , wherein the polyolefin is high density polyethylene (HDPE).
7. The method according to claim 1 , wherein the polyolefin is polypropylene.
8. The method according to claim 1 , wherein the amount of carbon black is 0.25 to 0.75 wt % based on the weight of the polyolefin composition.
9. The method according to claim 1 , wherein the amount of carbon black is 0.25 to 0.5 wt % based on the weight of the polyolefin composition.
10. The method according to claim 1 , wherein the amount of the optical brightener is 0.001 to 0.05 wt % based on the weight of the polyolefin composition.
11. The method according to claim 1 , wherein the amount of the optical brightener is 0.003 to 0.03 wt % based on the weight of the polyolefin composition.
12. The method according to claim 1 , wherein the optical brightener is 2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole).
13. The method according to claim 1 , wherein the amount of the UV agent is 0.1 to 1.0 wt % based on the weight of the polyolefin composition.
14. The method according to claim 1 , wherein the content of the polyolefin (A) in the polyolefin composition is at least 90 wt %.
15. The method according to claim 1 , wherein the sum of the contents of polyolefin (A), carbon black (B), optical brightener (C), and UV agent (D) is at least 95 wt % based on the weight of the polyolefin composition.
16. The method according to claim 1 , wherein the cable is a fiber optic micro cable.