GB1380972A - Manufacture of polymers containing n-silyl groups which can be shaped - Google Patents

Abstract

1380972 Silylated polyamides and polyamideacids CIBA-GEIGY AG 25 Feb 1972 [26 Feb 1971] 8837/72 Heading C3R Polymers containing N-silyl groups which are soluble in methylene chloride, cyclohexanone, tetrahydrofurane, N,N-dimethyl-form- or acetamide, dimethyl sulphoxide and N-methylpyrrolidone, have an inherent viscosity of 0À1 to 4À0 (0À5 g./100 ml. in dimethylacetamide/25‹ C.) and consisting substantially of identical or different recurring units where A is a divalent organic radical; R is a radical containing a 5- or 6-membered ring with the carbonyl groups attached to different C atoms, each of X 1 and X 2 is H or (and at least one in at least one unit is) -SiR 1 R 2 R 3 ; each of R 1 to R 3 is a substituted or unsubstituted C 1-4 alkyl, cycloalkyl, aryl or aralkyl radical; M 1 and M 2 are each adjacent to a carbonamide group and are the same or different COOX 3 groups; X 3 is SiR 1 <SP>1</SP>.R 2 <SP>1</SP>.R 3 <SP>1</SP>; each of R 1 <SP>1</SP> to R 3 <SP>1</SP> is a substituted or unsubstituted C 1-12 alkyl, cycloalkyl, aryl aralkyl, C 1-4 alkoxy or aryloxy radical; and n 1 and n 2 are each 1 or 2, or such polymers wherein at least one of n 1 and n 2 is 2 and at least some units are cyclized to the corresponding imide, are obtained by reacting a polymer of the same formula wherein X 1 and X 2 are H and M 1 and M 2 are COOH and which has an I.V. of 0À2 to 4À0 with one of 6 defined classes of silylating agents in an amount sufficient to introduce -SiR 1 .R 2 .R 3 radicals into at least some of the -CONH 1 groups as well as all the COOH groups. In a modification a silylating agent introducing -SiR 1 <SP>1</SP>.R 2 <SP>1</SP>.R 3 <SP>1</SP> into the COOH group may be used in a preliminary reaction. The 6 classes of silylating agents, which are more precisely defined in the Specification, are (i) amides such as bis-trimethylsilyl acetamide and bis-trimethylsilyl-p-methoxy-benzamide; (ii) amines such as trimethylsilylamine, hexamethyldisilazane and N,N-bis-(trimethylsilyl)aniline; (iii) diamines such as 1,4-bis-(N- methyl - N - trimethylsilylamino) - benzene; (iv) O-substituted hydroxylamines such as N- methyl - N - ethoxy - trimethylsilylamine; (v) oxamides such as tetrakis-(triethylsilyl)- oxamide; and (vi) sulphates such as bis-(triphenylsilyl)sulphate. Further classes of silylating agents which may be used in the preliminary step of the modification are also defined. The silylated polyamide-acids are stated to be more soluble and of lower viscosity, and thus more readily processable that the unsilylated polyamide acids; they can, if desired, be disilylated after processing. Extensive lists are given of polyamide-acid forming reactants and silylating agents and also of possible additives and applications (being in general those conventional for polyamide-acids). Reference is made to Specification 1,380,973.