Novel polyamide adhesives and method of preparation
AssigneeUnion Camp Corporation
InventorThomas T. Cheng
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Abstract
Novel polyamide hot melt adhesive compositions are disclosed together with a novel method of preparation. The process of the invention comprises condensation of hexamethylene diamine with an acid mixture of specific aliphatic C.sub.19 dicarboxylic acids, aliphatic C.sub.6 -C.sub.10 dicarboxylic acids and a specific class of C.sub.2 -C.sub.27 monocarboxylic acids. The process is carried out initially in aqueous solvent and in the presence of a catalyst selected from phosphoric acid, magnesium oxide and calcium oxide. The adhesive compositions are particularly useful in adhering poromerics such as natural and synthetic leather goods. The compositions of the invention are also useful adhesives for adhering metals.
Claims31
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.
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.degree. C. to about 300.degree. C. in the presence of a catalytic proportion of a catalyst selected from the class consisting of phosphoric acid, magnesium oxide and calcium oxide.
Dependencies are inferred from the claim text.