Novel polyamide adhesives and method of preparation

Claim 1

The polyamide obtained on condensation of substantially equivalent proportions of hexamethylene diamine and a mixture of acids, said mixture comprising aliphatic dicarboxylic acids of the formula: ##STR2##wherein X and Z are integers of from 0 to 15, inclusive, y is an integer of from 0 to 1 and the sum of X + y + Z is 15; aliphatic dicarboxylic acids of the formula: HOOC--R--COOH (II) wherein R represents alkylene of 4 to 8 carbon atoms, inclusive and monocarboxylic acids of the formula: R'--COOH (III) wherein R' is selected from the group consisting of alkyl having 1 to 21 carbon atoms, inclusive, phenyl and hydroxy-substituted phenyl; the ratio of the moles of the acid of formula (I) to the moles of acid of formula (II) in said mixture being in the range of from 1-2:1 and the ratio of the sum of the moles of acids of formulae (I) and (II) to the moles of formula (III) being from 1:0.0-0.08; said condensation being carried out in the presence of a catalytic proportion of a catalyst selected from the group consisting of phosphoric acid, magnesium oxide and calcium oxide and in the presence of an excess of an aqueous solvent.

Claim 21

A method of preparing a polyamide hot-melt adhesive, which comprises; reacting, in the presence of an excess of an aqueous solvent, substantially equivalent proportions of hexamethylene diamine and a mixture of acids, said mixture comprising aliphatic dicarboxylic acids of the formula: ##STR3## wherein X and Z are integers of from 0 to 15, inclusive, y is an integer of from 0 to 1 and the sum of X + y + Z is 15; aliphatic dicarboxylic acids of the formula: HOOC--R--COOH (II) wherein R represents alkylene of 4 to 8 carbon atoms, inclusive and monocarboxylic acids of the formula: R'--COOH (III) wherein R' is selected from the group consisting of alkyl having 1 to 21 carbon atoms, inclusive, phenyl and hydroxy-substituted phenyl; the ratio of moles of acid of formula (I) to the moles of acid of formula (II) in said mixture being in the range of from 1-2:1 and the ratio of the sum of the moles of acids of formulae (I) and (II) to the moles of formula (III) being from 1.0:0.0-0.08; and polymerizing the product of said reacting at a temperature within the range of from about 250° C. to about 300° C. in the presence of a catalytic proportion of a catalyst selected from the class consisting of phosphoric acid, magnesium oxide and calcium oxide.

Claim 22

A method of preparing a polyamide hot-melt adhesive, which comprises; reacting, in the presence of an excess of an aqueous solvent, substantially equivalent proportions of hexamethylene diamine and a mixture of acids, said mixture comprising aliphatic dicarboxylic acids of the formula: ##STR3## wherein X and Z are integers of from 0 to 15, inclusive, y is an integer of from 0 to 1 and the sum of X + y + Z is 15; aliphatic dicarboxylic acids of the formula: HOOC--R--COOH (II) wherein R represents alkylene of 4 to 8 carbon atoms, inclusive and monocarboxylic acids of the formula: R'--COOH (III) wherein R' is selected from the group consisting of alkyl having 1 to 21 carbon atoms, inclusive, phenyl and hydroxy-substituted phenyl; the ratio of moles of acid of formula (I) to the moles of acid of formula (II) in said mixture being in the range of from 1-2:1 and the ratio of the sum of the moles of acids of formulae (I) and (II) to the moles of formula (III) being from 1.0:0.0-0.08; and polymerizing the product of said reacting at a temperature within the range of from about 250° C. to about 300° C. in the presence of a catalytic proportion of a catalyst selected from the class consisting of phosphoric acid, magnesium oxide and calcium oxide.