Weatherability of flame retardant polyolefin

Abstract

Stabilized thermoplastic polymer, especially polyolefin compositions comprising a flame retardant selected from b1) melamin based flame retardants, or one of the compounds b2) bis-(hexachlorocyclopentadieno) cyclooctane, b3) tris-(2,3-dibromopropyl)-isocyanurate, b4) ethylene-bis-tetrabromophthalimide; b5) 1,2,5,6,9,10-hexabromo-cyclo-dodecan, b6) ethane-1,2-bis(pentabromophenyl); and c) a sterically hindered amine light stabilizer of the hydrocarbyloxyamine or hydroxyhydrocarbyloxyamine class and optional further components combine optimum outdoor weathering stability and good flame retardant properties.

1 . A process for imparting weathering stability, light stability and flame retardancy to a thermoplastic polymer (a) by addition of a flame retardant (b) and a sterically hindered amine (c), which process is characterized in that the flame retardant (b) is selected from the group consisting of 
 b1) melamine based flame retardants and/or ammonium polyphosphate,    b2) bis-(hexachlorocyclopentadieno) cyclooctane,    b3) tris-(2,3-dibromopropyl)-isocyanurate,    b4) ethylene-bis-tetrabromophthalimide,    b5) 1,2,5,6,9,10-hexabromo-cyclo-dodecane and    b6) ]1,2-bis(pentabromophenyl)ethane;    and the sterically hindered amine (c) is selected from the group consisting o hydrocarbyloxyamine and of the hydroxyhydrocarbyloxyamine sterically hindered amine light stabilizers.    provided that the flame retardant is not (b4) if the sterically hindered amine is hydroxyhydrocarbyloxyamines.    
     
     
         2 . Process of  claim 1  for imparting outdoor weathering stability and flame retardancy to a thermoplastic polymer, which is a polyolefin.  
     
     
         3 . Process of  claim 1  wherein the sterically hindered amine light stabilizer of component (c) is a cyclic sterically hindered amine conforming to the formula  
       
         
           
           
               
               
           
         
       
       wherein 
 G 1  and G 2  are independently alkyl of 1 to 4 carbon atoms or are together pentamethylene, and E 1  is C 1 -C 18 alkyl, C 5 -C 12 cycloalkyl or C 7 -C 15 aralkyl; or E 1  is C 1 -C 18 alkyl, C 5 -C 12 cyclo-alkyl or C 7 -C 15 aralkyl each of which is substituted in the aliphatic part by 1-3 OH groups; T is a divalent organic radical required to complete formula (I) to form, together with the hindered amine nitrogen atom and the two quaternary carbon atoms substituted by G 1  and G 2 , a five- or six-membered aliphatic ring structure;  
 or component (c) is an oligomeric or polymeric hindered amine molecule made from the reaction of a dialkyl ester or isocyanate with a compound of the formula (I) wherein E 1  contains 1 OH group and T is —CH 2 —CH(OH)—CH 2 —;  
 or component (c) is a simple diester or urethane derivative of a compound of the formula (I) wherein E 1  contains 1 OH group and T is —CH 2 —CH(OH)—CH 2 —.  
 
     
     
         4 . Process of  claim 1 , wherein component (c) is added in an amount of 0.01 to 10% by weight, based on the weight of the polymer (a).  
     
     
         5 . Process of  claim 1 , wherein component b1) is added in an amount from 1 to 50% by weight, or one or more of components b2), b3), b4), b5), b6) in a total amount from 0.5 to 20% by weight, each amount based on the weight of the polymer (a).  
     
     
         6 . Process of  claim 1  for imparting both weathering stability and flame retardancy to a polyethylene, polypropylene, or copolymer or blend thereof.  
     
     
         7 . Process of  claim 1  wherein one or more further components selected from the group consisting of pigments, dyes, plasticizers, antioxidants, thixotropic agents, levelling assistants, basic costabilizers, further light stabilizers, metal passivators, metal oxides, organophosphorus compounds, hydroxylamines, and mixtures thereof, are also added.  
     
     
         8 . Process of  claim 7 , wherein the further component is selected from the group consisting of pigments, phenolic antioxidants, calcium stearate, zinc stearate, sterically hindered amines and UV absorbers.  
     
     
         9 . Process of  claim 8 , wherein the further component is selected from the group consisting of the 2-(2′-hydroxyphenyl)benzotriazole, 2-(2-hydroxyphenyl)-1,3,5-triazine and the 2-hydroxyphenylbenzophenone UV absorbers.  
     
     
         10 . (canceled)  
     
     
         11 . A flame retardant and light stabilized composition comprising 
 (a) a polyolefin, and    b) a flame retardant selected from the group consisting of 
 b1) melamine based flame retardants and/or ammonium polyphosphate,  
 b2) bis-(hexachlorocyclopentadieno) cyclooctane,  
 b3) tris-(2,3-dibromopropyl)-isocyanurate,  
 b5) 1,2,5,6,9,10-hexabromo-cyclo-dodecane and  
 b6) 1,2-bis(pentabromophenyl)ethane; and  
   c) a hydroxyhydrocarbyloxyamine sterically hindered amine light stabilizer.    
     
     
         12 . A flame retardant and light stabilized composition according to  claim 11  wherein the sterically hindered amine light stabilizer of component (c) a compound of the formula  
       
         
           
           
               
               
           
         
       
       wherein 
 G 1  and G 2  are independently alkyl of 1 to 4 carbon atoms or are together pentamethylene, and E 1  is C 1 -C 1 8alkyl, C 5 -C 12 cycloalkyl or C 7 -C 15 aralkyl each of which is substituted in the aliphatic part by 1-3 OH groups;  
 T is a divalent organic radical required to complete formula (I) to form, together with the hindered amine nitrogen atom and the two quaternary carbon atoms substituted by G 1  and G 2 , a five- or six-membered aliphatic ring structure;  
 or component (c) is an oligomeric or polymeric hindered amine molecule made from the reaction of a dialkyl ester or isocyanate with a compound of the formula (I) wherein E 1  contains 1 OH group and T is —CH 2 —CH(OH)—CH 2 —;  
 or component (c) is a simple diester or urethane derivative of a compound of the formula (I) wherein E 1  contains 1 OH group and T is —CH 2 —CH(OH)—CH 2 —.  
 
     
     
         13 . A flame retardant and light stabilized composition according to  claim 11  wherein component (c) 1-(2-hydroxy-2-methylpropoxy)-4-octadecanoyloxy-2,2,6,6-tetramethylpiperidine.  
     
     
         14 - 18 . (canceled)  
     
     
         19 . Composition according to  claim 11  containing component (b) in an amount from 0.5 to 50% by weight, and component (c) in an amount of 0.01 to 10% by weight, each based on the weight of component (a).  
     
     
         20 . Composition according to  claim 11  additionally containing one or more further components selected from the group consisting of pigments, dyes, plasticizers, antioxidants, thixotropic agents, levelling assistants, basic costabilizers, metal passivators, metal oxides, organophosphorus compounds, hydroxylamines, further light stabilizers and mixtures thereof.  
     
     
         21 . Composition according to  claim 11  additionally containing one or more further components selected from the group consisting of pigments, phenolic antioxidants, calcium stearate, zinc stearate, sterically hindered amines and 2-hydroxy-benzophenone, 2-(2′-hydroxyphenyl)-1,3,5-triazine UV absorbers.  
     
     
         22 . Molded or extruded article comprising a composition according to  claim 11.