# US 4,391,968 A · Process for preparing polyamides having a modified dye affinity

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- Number: US 4,391,968 A
- Document ID: US4391968A
- Status: Granted
- Kind: A
- Application number: 06/236,512
- Filed: 1981-02-20
- Granted: 1983-07-05
- Earliest claimed: 1980-02-28
- Assignees: Montedison S.p.A.
- Inventors: Gianfranco Merani; Giuseppe Anzuino
- Web page: https://patentgrep.com/patent/US4391968A

## CPC

- C08G 69/42: Polyamides containing atoms other than carbon, hydrogen, oxygen, and nitrogen (C08G69/12, C08G69/32 take precedence)
- C08G 69/26: derived from polyamines and polycarboxylic acids
- C08G 69/265: {from at least two different diamines or at least two different dicarboxylic acids}
- D06M 13/192: Polycarboxylic acids; Anhydrides, halides or salts thereof {(D06M13/1845 takes precedence)}
- D06M 13/256: Sulfonated compounds {esters thereof, e.g. sultones}
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- D06M: TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS

## Abstract

Polyamides having a modified dye affinity are disclosed as prepared by polymerizing polyamide-forming monomers with a mixture consisting or consisting essentially of a dicarboxylic acid having the general formula HOOC--R--COOH, in which R is an aromatic, cyclo-aliphatic or aliphatic radical, and of a salt of a sulphonic dicarboxylic acid having the general formula: ##STR1## in which R has the meaning specified hereinbefore, X is an alkali or alkaline earth metal or ammonium, and n is a whole number from 1 to 4.

## Claims

### Claim 1

A process for preparing a fiber-forming polyamide having a modified dye affinity and no affinity for acid dyes and no affinity for basic dyes, which comprises polymerizing a composition of at least one polyamide-forming monomer and 1-45 millimols/kg monomer of a modifier composition consisting essentially of a mixture of a dicarboxylic acid having the general formula
HOOC--R--COOH (I)
wherein R is a simple or simply substituted aromatic radical having 6 to 18 carbon atoms, cycloaliphatic radical having 4 to 18 carbon atoms, or an alkylene radical having 1 to 12 carbon atoums, and
a salt of a sulphonated dicarboxylic acid having the general formula: ##STR4## wherein R has the meaning specified hereinabove, X is an alkali or alkaline earth metal or ammonium radical, and n is an integer from 1 to 4, in which the molar ratio between the salt of the sulphonated dicarboxylic acid and the dicarboxylic acid, ##STR5## ranges from 0.01 to 1.

### Claim 2 (depends on 1)

A process according to claim 1, wherein the dicarboxylic acid has the general formula (I) in which R is an alkylene radical having 4 to 10 carbon atoms, or an aromatic or cycloaliphatic radical having 6 carbon atoms, and in which the carboxylic groups are linked in ortho-, meta- or para-position.

### Claim 3 (depends on 1, 2)

A process according to claim 1 or 2, wherein the salt of a sulphonated dicarboxylic acid has the general formula (II) in which R is an aromatic radical containing 6 carbon atoms, n is 1, and the carboxylic groups are linked in meta- or para-position.

### Claim 4 (depends on 1, 2)

A process according to claim 1 or 2 wherein the amount of mixture consisting essentially of a dicarboxylic acid having the general formula (I) and a salt of a sulphonated dicarboxylic acid having the general formula (II) ranges from 20 to 35 millimols/kg of monomers.

### Claim 5 (depends on 1, 2)

A process according to claim 1 or 2, wherein the molar ratio between the salt of a sulphonated dicarboxylic acid having the general formula (II) and the dicarboxylic acid having the general formula (I) ranges from 0.1 to 0.5.

### Claim 6 (depends on 1, 2)

A process according to claim 1 or 2, wherein the monomer forming the polyamide is the salt of a dicarboxylic aliphatic acid with a diamine.

### Claim 7 (depends on 1, 2)

A process according to claim 1 or 2, wherein the monomer forming the polyamide is a lactam.

### Claim 8 (depends on 7)

A process according to claim 7, wherein the lactam is caprolactam.

### Claim 9 (depends on 1, 2)

Polyamide having no dye affinity for either acid or basic dyes, prepared according to the process claimed in claim 1 or 2.

### Claim 10 (depends on 9)

A fiber or filament of a polyamide as defined in claim 9.