Transparent polymer articles of low thickness

Abstract

The novel transparent polyolefin, polyester or polyamide article disclosed is stabilized against the effects of light, oxygen, heat and aggressive chemicals by addition of 0.005-0.30 % by weight the polymeric substrate of a hydroxyphenyl triazine UV absorber, and is characterized by its thickness between 1 and 500 μm. Preferred polyolefin articles thus stabilized are agricultural films containing as further stabilizer a sterically hindered amine. The novel compositions act as selective UV filter especially useful in agriculture.

What is claimed is:  
     
         1 . Transparent polyolefin, polyester or polyamide article having a thickness between 1 and 500 μm, which is stabilized against the effects of light, oxygen, heat and/or agressive chemicals by addition of 0.005-0.30% by weight, based on the polyolefin, polyester or polyamide, of a hydroxyphenyl triazine UV absorber.  
     
     
         2 . Transparent polyolefin article of  claim 1  having a thickness between 1 and 500 μm, which is stabilized against the effects of light, oxygen, heat and agressive chemicals by addition of 0.005-0.30% by weight, based on the polyolefin, of a hydroxyphenyl triazine UV absorber.  
     
     
         3 . Transparent polyolefin, polyester or polyamide article of  claim 1  containing as further stabilizer a sterically hindered amine in an amount of 0.01-6% by weight the polyolefin, polyester or polyamide.  
     
     
         4 . Transparent polyolefin, polyester or polyamide article of  claim 3  wherein the weight ratio sterically hindered amine : hydroxyphenyl triazine UV absorber ranges from 2:1 to 20:1.  
     
     
         5 . Transparent polyolefin, polyester or polyamide article of  claim 3  wherein the sterically hindered amine belongs to the class of hydroxylamine ethers.  
     
     
         6 . Transparent polyolefin, polyester or polyamide article of  claim 1  wherein the hydroxyphenyl triazine UV absorber conforms to the formula I  
       
         
           
           
               
               
           
         
       
       wherein 
 R 1  is H or OR 7 ;  
 R 2  and R 3  independently are H, C 1 -C 8 alkyl,  
                     
 OR 9 ;  
 R 4  and R 5  independently are H, C 1 -C 8 alkyl, OR 10 ;  
 R 6  is H, C 1 -C 18 alkyl, C 5 -C 12 cycloalkyl, C 7 -C 12 phenylalkyl, C 7 -C 12 alkylphenyl, C 3 -C 12 alkenyl, halogen, OH, OR 9 ;  
 R 8  is H; halogen; C 1 -C 12 alkoxy; C 1 -C 12 alkyl; C 3 -C 24 alkyl interrupted by oxygen and/or substituted by OH; or is NH—CO—R 14  or NH—COO—R 12 ;  
 R 7 , R 9  and R 10 O independently are H; C 1 -C 24 alkyl; C 3 -C 12 alkenyl; C 3 -C 24 alkyl interrupted by oxygen and/or substituted by OH; or is C 5 -C 12  cycloalkyl, C 7 -C 12  phenylalkyl, C 7 -C 12 alkylphenyl; CH 2 CH(OH)CH 2 OR 11 ; C 1 -C 12  alkyl substituted by COOR 12 , CONR 13 R 14 , OCOR 15 , OH or halogen; or R 7  is a polymeric hydrocarbon residue of 10 to 1000 carbon atoms;  
 and R 7  also embraces a residue of formula II  
                     
 wherein X is C 2 -C 24 alkylene; —CH 2 CH(OH)CH 2 —; —CH 2 CH(OH)CH 2 O—D—OCH 2 CH(OH)CH 2 ;  
 (C 1 -C 18 alkylene)—CO—O—D—O—CO—(C 1 -C 8 alkylene); CO; CO—(C 2 -C 24 alkylene)—CO;  
 C 3 -C 24 alkylene interrupted by oxygen;  
 D is C 2 -C 12  alkylene; C 4 -C 50 alkylene interrupted by O; phenylene; biphenylene or phenylene-E-phenylene;  
 E is O, S, SO 2 ; CH 2 ; CO or —C(CH 3 ) 2 —;  
 R 11  is H, C 1 -C 12 alkyl; phenyl; phenyl substituted by 1-3 C 1 -C 4 alkyl; C 5 -C 12 cycloalkyl; C 7 -C 12 phenylalkyl; C 3 -C 12 alkenyl;  
 R 12  is H; C 1 -C 24 alkyl; C 3 -C 12 alkenyl; C 3 -C 36 alkyl interrupted by oxygen and/or substituted by OH; or is C 5 -C 12  cycloalkyl, C 7 -C 12  phenylalkyl, C 7 -C 12  alkylphenyl; phenyl;  
 R 13  and R 14  independently are H, C 1 -C 18 alkyl; phenyl; phenyl substituted by 1-3 C 1 -C 4 alkyl and/or C 1 -C 4 alkoxy; C 5 -C 12 cycloalkyl; C 3 -C 12 alkenyl;  
 R 15  is C 1 -C 12 alkyl; phenyl; phenyl substituted by 1-3 C 1 -C 4 alkyl and/or C 1 -C 4 alkoxy; C 5 -C 12 cycloalkyl; C 3 -C 12 alkenyl; C 1 -C 12  alkoxy; or is NR 13 R 14 .  
 
     
     
         7 . Transparent polyolefin, polyester or polyamide article of  claim 6 , wherein in the hydroxyphenyl triazine UV absorber of formula I 
 R 2  and R 3  independently are H, methyl,                          OR 9 ;    R 4  and R 5  independently are H or methyl, especially H;    R 6  is H;    R 8  is H; C 1 -C 8 alkoxy; C 1 -C 8 alkyl;    R 7 , R 9  independently are H; C 1 -C 18 alkyl; C 3 -C 12  alkenyl; C 3 -C 24 alkyl interrupted by oxygen and/or substituted by OH; or is C 5 -C 12 cycloalkyl, C 7 -C 12 phenylalkyl, C 7 -C 12  alkylphenyl; C 1 -C 12 alkyl substituted by COOR 12 , OCOR 15 , OH; or R 7  is a polymeric hydrocarbon residue of 20 to 500 carbon atoms;    and R 7  also embraces a residue of formula II, wherein X is C 2 -C 18 alkylene; —CH 2 CH(OH)CH 2 —; —CH 2 CH(OH)CH 2 O—D—OCH 2 CH(OH)CH 2 ;    (C 1 -C 4 alkylene)—CO—O—D—O—CO—(C 1 -C 4 alkylene); CO; CO—(C 2 -C 18 alkylene)—CO;    C 3 -C 18 alkylene interrupted by oxygen; D is C 2 -C 12 alkylene;    R 12  is H; C 1 -C 24 alkyl; C 3 -C 12 alkenyl; C 3 -C 24 alkyl interrupted by oxygen and/or substituted by OH; or is C 5 -C 12 cycloalkyl, C 7 -C 12 phenylalkyl, C 7 -C 12 alkylphenyl; phenyl;    R 15  is C 1 -C 12 alkyl; C 5 -C 12 cycloalkyl; C 3 -C 12 alkenyl.    
     
     
         8 . Transparent polyolefin, polyester or polyamide article of  claim 1  which is a film, fiber, ribbon or stretched tape, especially a polyolefin agricultural film.  
     
     
         9 . Transparent polyolefin, polyester or polyamide article of  claim 8  having a thickness between 1 and 300 μm, especially between 1 and 200 μm.  
     
     
         10 . Transparent polyolefin article of  claim 1 , wherein the polyolefin is polyethylene or polypropylene.  
     
     
         11 . Transparent polyolefin, polyester or polyamide article of any of  claims 1  to  10  additionally containing a further component selected from the group consisting of processing stabilizers, fillers, clarifiers, modifiers, acid scavengers, flame retardants and, especially, further light stabilizers.  
     
     
         12 . Use of the transparent polyolefin film of  claim 8  for suppressing microbial growth in a protected cultivation.  
     
     
         13 . Process for suppressing microbial growth in a protected environment, which process comprises covering the environment with the transparent polyolefin film of  claim 8 .  
     
     
         14 . Process of  claim 13 , wherein the protected environment is a plant cultivation.  
     
     
         15 . A method for selectively screening solar and/or artificial light radiation to crops contained inside a green house which comprises covering said green house with the polyolefin film of  claim 8 .  
     
     
         16 . A compound of one of the formulae a, b, f, g, h or k  
       
         
           
           
               
               
           
         
       
       wherein X is C 13 -C 24 alkylene; (C 1 -C 18 alkylene)—CO—O—D—O—CO—(C 1 -C 18 alkylene) where D is C 2 -C 12 alkylene; CO—(C 13 -C 24 alkylene)—CO; C 3 -C 24 alkylene interrupted by oxygen, especially (C 1 -C 3 alkylene)—O—(C 1 -C 3 alkylene).