Polyolefin composition providing marking by fluorescence

Abstract

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 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 polyolefin composition 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. 
     
     
         3 . The polyolefin composition according to  claim 1 , wherein the ethylene copolymer is a copolymer of ethylene and a C 3 -C 12 -alpha-olefin. 
     
     
         4 . The polyolefin composition according to  claim 1 , wherein the propylene copolymer is a copolymer of propylene and ethylene and/or a C 4 -C 12 -alpha-olefin. 
     
     
         5 . The polyolefin composition according to  claim 1 , wherein the polyolefin is high density polyethylene (HDPE). 
     
     
         6 . The polyolefin composition according to  claim 1 , wherein the polyolefin is polypropylene. 
     
     
         7 . The polyolefin composition according to  claim 1 , wherein the amount of carbon black is 0.25-0.75 wt %, preferably 0.25-0.5 wt %, based on the weight of the polyolefin composition. 
     
     
         8 . The polyolefin composition according to  claim 1 , wherein the amount of the optical brightener is 0.001 to 0.05 wt %, preferably 0.003 to 0.03 wt %, based on the weight of the polyolefin composition. 
     
     
         9 . The polyolefin composition according to  claim 1 , wherein the optical brightener is 2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole). 
     
     
         10 . The polyolefin composition 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. 
     
     
         11 . A molded article comprising, preferably consisting of, a polyolefin composition according to  claim 1 . 
     
     
         12 . The molded article according to  claim 11 , wherein the article is an outer layer of a cable. 
     
     
         13 . A cable comprising an outer layer comprising, preferably consisting of, the polyolefin composition according to  claim 1 . 
     
     
         14 . A method for detection of a polyolefin composition by UV light comprising the following steps
 providing a polyolefin composition according to  claim 1 ,   irradiating the polyolefin composition with UV light,   detecting fluorescence emitted from the polyolefin composition.   
     
     
         15 . A method for detection of a molded article or a cable by UV light comprising the following steps
 providing a molded article or a cable according to  claim 11 ,   irradiating the molded article or the cable with UV light,   detecting fluorescence emitted from the molded article or the cable.   
     
     
         16 . A method for detection of a molded article or a cable by UV light comprising the following steps
 providing a molded article or a cable according to  claim 13 ,   irradiating the molded article or the cable with UV light,   detecting fluorescence emitted from the molded article or the cable.