Polyester and polyamide compositions of low residual aldehyde content

Abstract

A mixture of a polyester, such as poly(ethylene terephthalate) PET, or a polyamide, and a suitable stabilizer selected from the group consisting of hydroxylamine stabilizers, substituted hydroxylamine stabilizers, nitrone stabilizers and amine oxide stabilizers, when extrusion compounded exhibits a lower residual acetaldehyde content than does polyester or polyamide alone when similarly treated. The invention pertains to any polyester or polyamide used in the manufacture of molded articles, fibers or films, for instance bottles or containers which are used to store consumer materials, for example food, beverages and water.

1 - 21 . (canceled)  
   
   
       22 . A mono- or multi-layered plastic container or film, stabilized against the formation of aldehydic contaminants during melt processing of said container or film, comprising at least one layer which comprises 
 an extrusion blend comprising    (a) a polyester and    (b) an effective stabilizing amount of at least one compound selected from the group consisting of 
 iv.) amine oxide stabilizers,  
   wherein in the polyester    the dicarboxylic acid repeat units are selected from the group consisting of terephthalic acid, isophthalic acid, o-phthalic acid, naphthalene dicarboxylic acid, cyclohexane dicarboxylic acid, cyclohexanediacetic acid, diphenyl-4,4′-dicarboxylic acid, succinic acid, glutaric acid, adipic acid, sebacic acid and mixtures thereof; and the diol portion is derived from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, propane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, 1,4-cyclohexanedimethanol, 3-methylpentane-2,4-diol, 2-methylpentane1,4-diol, 2,2-diethylpropane-1,3-diol, 1,4-di-(hydroxyethoxy)benzene, 2,2-bis(4-hydroxycyclohexyl)-propane, 2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane, 2,2-bis-(3-hydroxy-ethoxyphenyl)propane, 2,2-bis-(4-hydroxypropoxyphenyl)ethane and mixtures thereof.    
   
   
       23 . A plastic container according to  claim 22  which is a rigid bottle.  
   
   
       24 - 28 . (canceled)  
   
   
       29 . A container or film according to  claim 22  wherein component (a) is 95-99.99% by weight and the stabilizers of component (b), in total, are 5 to 0.01% by weight, based on the total weight of (a) and (b).  
   
   
       30 . A container or film according to  claim 22  wherein component (a) is 98-99.99% by weight and component (b) is 2 to 0.01% by weight, based on the total weight of (a) and (b).  
   
   
       31 . A container or film according to  claim 22  wherein component (a) is 99-99.97% by weight and component (b) is 1 to 0.03% by weight, based on the total weight of (a) and (b).  
   
   
       32 . A container or film according to  claim 22  where component (a) is poly(ethylene terephthalate) or poly(ethylene 2,6-naphthalene-2,6-dicarboxylate).  
   
   
       33 . A container or film according to  claim 22  where component (a) is poly(ethylene terephthalate).  
   
   
       34 . A container or film according to  claim 22  wherein component (b) is at least one amine oxide stabilizer of the formula (VI)  
     
       
         
         
             
             
         
       
       wherein  
       G 1  and G 2  are independently a straight or branched chain alkyl of 6 to 36 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to 36 carbon atoms, alkaryl of 7 to 36 carbon atoms, cycloalkyl of 5 to 36 carbon atoms, alkcycloalkyl of 6 to 36 carbon atoms or cycloalkylalkyl of 6 to 36 carbon atoms;  
       G 3  is a straight or branched chain alkyl of 1 to 36 carbon atoms, aryl of 6 to 12 carbon atoms, aralkyl of 7 to 36 carbon atoms, alkaryl of 7 to 36 carbon atoms, cycloalkyl of 5 to 36 carbon atoms, alkcycloalkyl of 6 to 36 carbon atoms or cycloalkylalkyl of 6 to 36 carbon atoms; with the proviso that at least one of G 1 , G 2  and G 3  contains a b carbon-hydrogen bond; and  
       wherein said aryl groups may be substituted by one to three halogen, alkyl of 1 to 8 carbon atoms, alkoxy of 1 to 8 carbon atoms or combinations thereof; and  
       wherein said alkyl, aralkyl, alkaryl, cycloalkyl, alkcycloalkyl and cycloalkylalkyl groups may be interrupted by one to sixteen —O—, —S—, —SO—, —SO 2 —, —COO—, —OCO—, —CO—, —NG 4 -, —CONG 4 - and —NG 4 CO— groups, or wherein said alkyl, aralkyl, alkaryl, cycloalkyl, alkcycloalkyl and cycloalkylalkyl groups may be substituted by one to sixteen groups selected from —OG 4 , —SG 4 , —COOG 4 , —OCOG 4 , —COG 4 , —N(G 4 ) 2 , —CON(G 4 ) 2 , —NG 4 COG 4  and 5- and 6-membered rings containing the —C(CH 3 )(CH 2 R x )NL(CH 2 R x )(CH 3 )C— group or wherein said alkyl, aralkyl, alkaryl, cycloalkyl, alkcycloalkyl and cycloalkylalkyl groups are both interrupted and substituted by the groups mentioned above; and  
       wherein  
       G 4  is independently hydrogen or alkyl of 1 to 8 carbon atoms;  
       R x  is hydrogen or methyl;  
       L is hydrogen, hydroxy, C 1-30  straight or branched chain alkyl moiety, a —C(O)R moiety where R is a C 1-30  straight or branched chain alkyl group, or a —OR y  moiety; and  
       R y  is C 1-30  straight or branched chain alkyl, C 2 -C 30  alkenyl, C 2 -C 30  alkynyl, C 5 -C 12  cycloalkyl, C 6 -C 10  bicycloalkyl, C 5 -C 8  cycloalkenyl, C 6 -C 10  aryl, C 7 -C 9  aralkyl, C 7 -C 9  aralkyl substituted by alkyl or aryl, or —CO(D), where D is C 1 -C 18  alkyl, C 1 -C 18  alkoxy, phenyl, phenyl substituted by hydroxy, alkyl or alkoxy, or amino or amino mono- or di-substituted by alkyl or phenyl.  
     
   
   
       35 . A container or film according to  claim 34  in which in the amine oxide stabilizers of formula (VI), G 1  and G 2  are independently alkyl groups of 8 to 26 carbon atoms and G 3  is methyl.  
   
   
       36 . A container or film according to  claim 22  further comprising (c) an effective stabilizing amount of poly(vinyl alcohol) or an ethylene/vinyl alcohol copolymer.  
   
   
       37 . A container or film according to  claim 22  further comprising (d) an effective stabilizing amount of a polyhydric alcohol of the formula E-(OH) n    where    n is 2 to 4000, and    E is a hydrocarbyl moiety.    
   
   
       38 . A container or film according to  claim 22  further comprising (e) an effective stabilizing amount of a polymer which is polyacrylamide, polymethacrylamide or an acrylamide or methacrylamide copolymer with at least one ethylenically unsaturated comonomer.  
   
   
       39 . A container or film according to  claim 22  further comprising trimethylolpentane, pentaerythritol or dipentaerythritol.  
   
   
       40 . A container or film according to  claim 22  further comprising one or more colorants selected from the group consisting of pigments and dyes.