Abstract Linear polyamide-imides having recurring units of the formula ##STR1## in which A is an aromatic radical; R and R' are araliphatic, aliphatic, or cycloaliphatic radicals; and R" is H, or an aliphatic, araliphatic, or cycloaliphatic radical; and a process for their preparation are disclosed. The process involves three steps (1) condensation of a diamine and an aromatic tricarboxylic acid anhydride to form an intermediate diimide-diacid; (2) converting the diimide-diacid to the diacid chloride, e.g. by reaction with SOCl 2 ; and (3) reaction of the diacid chloride with further diamine to produce the amide linkages in the desired polyamide-imide. This method avoids a final step of imide formation by cyclodehydration, necessary in the prior art processes, which step causes some crosslinking undesirable in polymers intended for molding applications.
A process for preparing a linear polyamideimide consisting essentially of recurring units having the formula ##STR7## in which A is an aromatic radical; R and R' are araliphatic, aliphatic or cycloaliphatic radicals in which the carbon atoms attached to N are aliphatic carbon atoms; R" is H, or an araliphatic, aliphatic or cycloaliphatic radical; or both R" radicals together form a divalent aliphatic radical; comprising the steps of
Claim 2
Dependent Claim
68 words
A process for preparing a linear polyamideimide consisting essentially of recurring units having the formula ##STR7## in which A is an aromatic radical; R and R' are araliphatic, aliphatic or cycloaliphatic radicals in which the carbon atoms attached to N are aliphatic carbon atoms; R" is H, or an araliphatic, aliphatic or cycloaliphatic radical; or both R" radicals together form a divalent aliphatic radical; comprising the steps of
Claim 3
Dependent Claim
62 words
reacting an aromatic tricarboxylic acid anhydride having the formula ##STR8## with a diamine of the formula H.sub.2 N--R--NH.sub.2 to form a diacid imide of the formula ##STR9## forming the corresponding acid halide derivative by converting the carboxyl groups in the diacid imide to halocarbonyl groups; and then polycondensing said acid halide derivative of the imide with an amine of the formula HR"N--R'--N--R"H.
Claim 4
Dependent Claim
62 words
reacting an aromatic tricarboxylic acid anhydride having the formula ##STR8## with a diamine of the formula H.sub.2 N--R--NH.sub.2 to form a diacid imide of the formula ##STR9## forming the corresponding acid halide derivative by converting the carboxyl groups in the diacid imide to halocarbonyl groups; and then polycondensing said acid halide derivative of the imide with an amine of the formula HR"N--R'--N--R"H.
Claim 5
Dependent Claim
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The process of claim 1 in which said aromatic tricarboxylic acid anhydride is trimellitic anhydride.
Claim 6
Dependent Claim
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The process of claim 1 in which R is alkylene having 2 to 18 carbon atoms.
Claim 7
Dependent Claim
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The process of claim 1 in which R' is alkylene having 2 to 18 carbon atoms and R" is H.
Claim 8
Dependent Claim
37 words
The process of claim 2 in which said aromatic tricarboxylic acid anhydride is trimellitic anhyhdride; R is alkylene having 2 to 18 carbon atoms; R' is alkylene having 2 to 18 carbon atoms and R" is H.