Patent GB-1088769-A (GB)
Title: Polyamide-polyimide polymers
IPC: C08G69/42
Filed: 1964-10-15
Abstract: The invention comprises two methods of preparing silicon containing polyamide/polyimides.  In the first method 45-99% of a polyamide/polyimide prepared from (A) 45-55% of an aromatic acid having at least 3 carbonyl groups, 2 of which are ortho to each other, or an ester or anhydride thereof and (B) 45-55% of an aliphatic or aromatic diamine containing at least one primary amino group is treated with 1-55% of a silicon compound of formula <FORM:1088769/C3/1> in which Y is a carboxyl, hydroxyl, aldehyde, amide, amidine, primary amine, anhydride, carbamate, carbodiimide, epoxide, isocyanate, isocyanide, isothiocyanate, isothiourea, ketoxime, lactam, lactide, mercaptan, oxime, ozonide, peroxide, semicarbazide, thiol, thiocyanate or ureido group, Z is a divalent organic radical bonded to Si* by an Si-C bond, R is a hydrocarbon or halohydrocarbon radical bonded to Si* by an Si-C bond, X is a hydrolysable group, G is a silyl, siloxy, silalkenyl, silarylenyl, siloxanoxy, siloxanalkylene, siloxanarylene, cyclosiloxanoxy, cyclosilalkylene, cyclosilarylene or silsequioxanoxy radical joined to Si* by an Si-Si, Si-O-Si, or Si-divalent hydrocarbon-Si bond and g + h=O to 3.  The aromatic acid or derivatives thereof may contain up to 6 reactive groups. Ester derivatives may be derived from C1- 10 alkanols, haloalkanols, cycloalkanols, phenols and halophenols. Acidic compounds specified include pyromellitic acid dianhydride, naphthalene-2,3,6,7-tetracarboxylic acid dianhydride and 3,31,4,41-diphenyltetracarboxylic acid dianhydride. The diamine may be of formula NH2-R1-NH2 or NH2-R1-NHR, where R1 is an organic radical. Amines specified include bis(4-aminophenyl)-ether, benzidine and 1,5-diaminonaphthalene. The acid and amine may be mixed dry or either or both dissolved in a polar solvent prior to mixing. Solvents specified include dimethyl formamide, dimethyl acetamide, N-methyl pyrrolidone and dimethyl sulphone.  These may be mixed with up to 60% of a non-pola solvent.  Non-polar solvents specified includ xylene and b -ethoxy-ethyl acetate.  The reaction temperature may be up to 70 DEG  C.  Water should be absent. The polyamide/polyimide may have 5 to 500,000 repeating units. Silicon containing compounds specified include:  <FORM:1088769/C3/2> <FORM:1088769/C3/3> and a condensate containing the following reactive groups:  <FORM:1088769/C3/4> and <FORM:1088769/C3/5> The silicon containing compounds are added to a clear viscous solution of the polyamide/polyimide. They form pendant groups on the polymer chain.  After the addition the product is heated to above 40 DEG  C. and finally cured at up to 500 DEG  C.  A curing catalyst, e.g. dicyclohexylcarbodiimide may be used.  In the second method 45-55% of an aromatic acid having at least 3 carboxyl groups, 2 of which are ortho to each other, or an ester or anhydride thereof is treated with 45-55% of a diamine of formula <FORM:1088769/C3/6> or <FORM:1088769/C3/7> in which R11 is an organic radical bonded to Si by an Si-C bond.  Diamines of this type specified include:  <FORM:1088769/C3/8> and <FORM:1088769/C3/9> The silicon containing diamine may be mixed with an ordinary diamine as specified for the first method.  The reaction conditions are the same as those for the polyamide/polyimide formation reaction in the first method.  After the reaction the mixture may be heated to above 50 DEG C.  Use.-Films, protective and insulating coatings for wire and glass, glass laminates and impregnating paper.