CA2034393C

CA2034393C - Stabilisation of dyeings on polyamide fibres

Info

Publication number: CA2034393C
Application number: CA002034393A
Authority: CA
Inventors: Gerhard Reinert; Francesco Fuso
Original assignee: Ciba Spezialitaetenchemie Holding AG
Current assignee: BASF Schweiz AG
Priority date: 1990-01-19
Filing date: 1991-01-17
Publication date: 2002-01-08
Anticipated expiration: 2011-01-17
Also published as: JPH04214483A; DE59105066D1; EP0438381B1; US5096456A; CA2034393A1; JP3051461B2; EP0438381A1

Abstract

A process for improving the thermal and/or photochemical stability of dyeings on polyamide fibres by applying to said fibres, from an aqueous medium, water-soluble phenolic antioxidants of formula (A-Y-)n Z(-W)m, wherein A, Y, Z, W, m and n are as defined in claim 1.

Description

~~~~e~~~

1-17923 +
Stabilisation of dyeings on~olyamide fibres The present invention relates to a process for improving the thermal and/or photochemical stability of dyeings on polyamide fibres and to the polyamide fibre material so treated.
It is taught in US patent specification 3 665 031 to protect undyed polymers such as polyamides against the action of heat and/or oxygen (atmospheric oxgyen) with the aid of water-soluble phenolic antioxidants.
Dyeings on polyamide fibres which are dyed with disperse, acid or 1:2 metal complex dyes tend to be thermally and photochemically instable. This tendency is especially marked when polyamide fibres are dyed with a red dye or with a dye mixture containing at least one red component.
It has now been found that this shortcoming can be entirely or at least substantially eliminated by treating the dyed polyamide material with phenolic water-soluble antioxidants.
The invention therefore relates to a process for improving the thermal and/or photochemical stability of dyeings on polyamide fibres, which process comprises applying to said polyamide fibres, from an aqueous medium, a compound of formula (1) ( 1 ) (A-Y-)aZ(-~r~
wherein A is the radical of a sterically hindered phenol of the benzene series, Y is a radical of formula (2) or (3) 12 ~ 13 (2) -(X)x N Y -N _(X~)x,-- 2 - ~03~39~3 (3) _(X>)x.-N-C Y (X)x-wherein X and X' are each independently of the other alkylene, oxaalkylene or thiaalkylene, R2 and Rg are each independently of the other hydrogen or an unsubstituted or substituted alkyl group, and x, x' and y are each independently of the other 0 or 1, Z is an aliphatic or a carbocyclic aromatic radical, which last mentioned radical contains not more than two mono- or bicyclic nuclei, W is a sulfo group, and m and n are each independently of the other 1 or 2, and the water-soluble salts thereof.
A in formula (1) may be a monohydroxyphenyl radical which is substituted in at least one ortho-position to the hydroxyl group by an alkyl, cycloalkyl or aralkyl group and which may carry additional substituents.
Alkyl groups in ortho-position to the hydroxyl group in A may be straight-chain or branched and contain 1 to 12, preferably 4 to 8, carbon atoms. a-Branched alkyl groups are preferred. Such groups are typically methyl, ethyl, isopropyl, tert-butyl, isoamyl, octyl, tert-octyl and dodecyl. Tert-butyl is particularly preferred.
Cycloalkyl groups in o-position to the hydroxyl group in A contain 6 to 10, preferably 6 to 8, carbon atoms. Illustrative examples of such groups are cyclohexyl, methylcyclohexyl and cyclooctyl.
Aralkyl groups in o-position to the hydroxyl group in A contain 7 to 10, preferably 8 to 9, carbon atoms. Illustrative examples of such groups are the a-methyl and a,a-dimethyl-benzyl group.
The radical A may be substituted by further alkyl, cycloalkyl or aralkyl groups as defined above, which groups are preferably in o'- or p-position to the hydroxyl group, provided these positions are not occupied by the bond to Y. In addition, the radical A
is preferably unsubstituted in at least one m-position to the hydroxyl group, whereas the other may be substituted by lower alkyl groups such as the methyl group.

~0~43~~
Owing to the ease with which they can be obtained and to their good stabilising action, compounds of formula (1) are especially preferred in which A is a radical of formula (4) R
R~
wherein R and Rt a.~-e each independently of the other hydrogen, methyl or tert-butyl, and the sum of the carbon atoms of R and Rt is not less than 2.
X and X' in formulae (2) and (3) may be straight-chain or branched and contain 1 to 8, preferably 1 to 5, carbon atoms. Illustrative examples are the methylene, ethylene, trimethylene, propylene, 2-thiatrimethylene or the 2-oxapentamethylene radical.
Especially preferred are compounds in which two hetero atoms in the radicals X
and X' are not attached to the same saturated, i.e. tetrahedral, carbon atom.
R2 or R3 in formulae (2) and (3) as alkyl groups may be straight-chain or branched and contain 1 to 18, preferably 1 to 8, carbon atoms. Such groups are typically methyl, ethyl, isopropyl, pentyl, octyl, dodecyl and octadecyl.
A substituted alkyl group R2 or R3 is typically a hydroxyalkyl, alkoxyalkyl, aminoalkyl, alkylaminoalkyl group or a dialkylaminoalkyl group containing a total of 2 to 10, preferably 2 to 5, carbon atoms. Illustrative examples of such groups are the ~i-hydroxy-ethyl, (3-methoxyethyl, ~3-aminoethyl, ~i,~i'-diethylaminoethyl or ~3-butylaminoethyl group.
R2 or R3 may also be an aryl group, preferably the phenyl group.
Particularly preferred compounds of formula (1) are those wherein Y is a radical of formula (5) (s) _x"_~_~_ wherein R4 is hydrogen or Cl-C4alkyl and X" is Ct-C4alkylene.
Z in formula (1) is, for example, the radical of an unsubstituted or carboxy-substituted lower alkane of at least two carbon atoms, the radical of an unsubstituted benzene nucleus or of a benzene nucleus which is substituted by chlorine or bromine, Cl-C4alkyl, Ct-C4alkoxy, Ct-C4alkoxycarbonylamino, hydroxy, carboxy, phenylethyl, styryl, phenyl, phenoxy, phenylthio, phenylsulfonyl or acylamino, and the group W may be attached direct to said benzene nucleus or to a monocyclic aryl radical of one of the substituents thereof, or is a radical of a naphthalene or tetraline nucleus.
Z as radical of a lower alkane may be straight-chain or branched and contain 2 to 5, preferably 2, carbon atoms. Said radical may therefore be ethylene, propylene, trimethylene or pentamethylene. This radical may be substituted by carboxyl groups and is, for example, the carboxyethylene radical.
Z in formula (1) as a radical of a benzene nucleus may be further substituted and contain, for example, straight-chain or branched Ct-C4alkyl groups such as methyl, ethyl or isopropyl. The preferred substituent is the methyl group. Ct-C4Alkoxy groups as substituents of a benzene nucleus Z are, for example, methoxy, ethoxy or butoxy. If Z as a radical of a benzene nucleus is substituted by an acylamino group, then its acyl radical is derived preferably from a C2-C6aliphatic or from a monocarbocyclic aromatic carboxylic acid. Illustrative examples are the radical of acetic, propionic, (3-methoxypropionic, benzoic, aminobenzoic or methylbenzoic acid. Exemplary of Ct-C4alkoxycarbonylamino groups as substituents of a benzene nucleus Z are methoxycarbonylamino, ethoxycarbonylamino or butoxycarbonylamino.
If the radical Z contains as substituents phenylethyl, styryl, phenyl, phenoxy, phenylthio-or phenylsulfonyl groups, then said substituents may be substituted by chlorine or bromine, Ct-C~alkyl groups such as the methyl or ethyl group, Ct-C4alkoxy groups such as methoxy, acylamino groups such as the acetyl or benzoylamino group, or alkoxy-carbonylamino groups such as methoxycarbonylamino or ethoxycarbonylamino.

~U3~:393 Optionally, also several of the substituents of the benzene nucleus Z
mentioned above or of its substituents containing aryl groups can be present simultaneously.
These may be identical or different.
Z as a radical of a naphthalene nucleus may additionally be substituted by Cl-C4alkyl or alkoxy groups such as methyl or methoxy.
The sulfo group W in formula (1) is preferably free, but may also be in the form of its alkali metal or alkaline earth metal salts, of the ammonium salt or of the salts of organic bases. Owing to the sparing water-solubility of certain calcium, strontium and barium salts in aqueous media, and also for economic reasons, compounds of formula (1) are preferred in which the group W is in the form of its lithium, sodium, potassium, magnesium or ammonium salt, or of the ammonium salt of an organic nitrogen base whose cation has the formula (6) (6) NR'R"R"'R""
wherein R', R", R"', R"" are each independently of one another hydrogen, a Ct-C4alkyl or (3-hydroxy-Ct-C4alkyl radical or a cyclohexyl radical, with the proviso that at least two of these radicals are able to form with each other a carbocyclic or heterocyclic ring system.
Exemplary of organic nitrogen bases which, with the group W, are able to form such ammonium salts are: trimethylamine, triethylamine, triethanolamine, diethanolamine, ethanolamine, cyclohexylamine, dicyclohexylamine, hexamethyleneimine or morpholine.
Compounds having a particularly good stablising action are compounds of formula (7) R

II
H ~ ~ X"-C-N Z-W
R~
n - 6 - ~(~;~~~.393 wherein R and Rt are each independently of the other methyl or tert-butyl, R4 is hydrogen or Cl-C4alkyl, X" is Ct-C4alkylene, Z is ethylene, a divalent or trivalent radical of benzene or naphthalene or is a divalent radical of diphenyl ether, W is the sulfo group, and nislor2.
The group W in these compounds may be in the free form or also in the form of its salts as defined above.
The water-soluble compounds of formula (1) are known, for example from US
patent specification 3 665 031, and can be prepared by methods which are known per se, for example by reacting n mol of a compound of formula (81 (8) A-(X)x-P
with 1 mol of a compound of formula (9) (9) ~ W~ Z'--~(X ~ )x,_Q~n in which formulae one of P and Q is the group -NH-R3 and the other is the group ~2 y COV, V, where y = 1, is the -OAr group and, where y = 0, is a chlorine or bromine atom or a reactive amino group, and Ar is an aromatic radical of the benzene or naphthalene series, and A, Z, W, R2, X, X', x, m, n and y are as defined hereinbefore with the elimination of HV.
Representative examples of starting compounds of formula (10) ~03~39~
(10) A_(X)X NH_R3 wherein A, X, x and R3 are as defined above, which compounds fall under formula (8) and are suitable for the preparation of the water-soluble compounds of this invention, are:
4-hydroxy-3,5-di-tart-butylaniline, 4-hydroxy-3,5-di-tart-butylbenzylamine, y-(4-hydroxy-3,5-di-tart-butylphenyl)propylamine, 4-hydroxy-3-tart-butyl-5-methylaniline, 4-hydroxy-3,5-dicyclohexylaniline, 4-hydroxy-3,5-di-tart-amylaniline, 4-hydroxy-3,5-di-cyclohexylbenzylamine, 4-hydroxy-3-methylcyclohexyl-5-methylaniline, 2-hydroxy-a,a-dimethylbenzyl-5-methylbenzylamine, 4-hydroxy-3,5-dibenzylaniline, Y-(4-hydroxy-3,5-dibenzylphenyl)propylamine, 2-hydroxy-3-tart-butyl-5-dodecylaniline, 4-hydroxy-3-tart-octyl-5-methylbenzylamine, 4-hydroxy-3,5-diisopropylbenzylamine, 4-hydroxy-3-tart-butyl-b-methylbenzylamine, 4-hydroxy-3,5-di-tart-amylbenzylamine, 2-hydroxy-3,5-dimethylaniline and 2-hydroxy-3-tent-butyl-5-methylbenzylamine.
Representative examples of starting compounds of formula (11) ~2 ( 11 ) A-(X x N y COV
wherein A, X, x, R2, y and V are as defined above, which compounds fall under formula (8) are:
(3-(4-hydroxy-3,5-di-tart-butylphenyl)propionyl chloride, 4-hydroxy-3,5-di-tart-butyl-phenylacetyl chloride, 4-hydroxy-3,5-di-tart-butylbenzoyl chloride, 4-hydroxy-3-tert-butyl-5-methylphenylacetyl chloride, 2-hydroxy-3,5-dimethylbenzoyl chloride, 2-hydroxy-3-ten-butyl-5-methylbenzoyl chloride, S-(4-hydroxy-3-tart-butyl-5-methyl-benzyl)thioglycolyl chloride, 4-hydroxy-5-tart-butylphenylacetyl chloride, (i-(4-hydroxy-3,5-dicyclohexylphenyl)propionyl bromide, (4-hydroxy-3,5-dicyclohexylphenyl)acetyl chloride, (3-(4-hydroxy-3-benzyl-5-methylphenyl)propionyl chloride, (4-hydroxy-3-benzyl-5-methylphenyl)acetyl chloride, 4-hydroxy-3,5-diisopropylphenylacetyl chloride, S-(4-hydroxy-3,5-diisopropylbenzyl)thioglycolyl chloride, (3-(w-(4-hydroxy-3,5-di-tart-butylphenyl)propoxy]propionyl chloride, [co-(4-hydroxy-3,5-di-tart-butylphenyl)propoxy]acetyl chloride, (3-methyl-[i-(4-hydroxy-3,5-di-tart-butyl-phenyl)propionyl chloride, 4-hydroxy-3,5-di-tart-amylbenzyloxyacetyl chloride, and 4-hydroxy-5-tart-butyl-3-ethylbenzyloxyacetyl chloride.
Representative examples of starting compounds of formula (12) (12) ~'~m Z~'~')x'-NH-R3]n wherein W, m, Z, X', x', R3 and n are as defined above, which compounds fall under formula (9), are:
2-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 4-aminobenzenesulfonic acid, 5-chloro-2-aminobenzenesulfonic acid, 5-methyl-4-chloro-2-aminobenzenesulfonic acid, 2-chloro-5-aminobenzenesulfonic acid, 4-chloro-3-aminobenzenesulfonic acid, 5-chloro-3-methyl-3-aminobenzenesulfonic acid, 2,5-dichloro-4-aminobenzenesulfonic acid, 3-bromo-6-aminobenzenesulfonic acid, 3,4-dichloro-6-aminobenzenesulfonic acid, 1-aminotetraline-4-sulfonic acid, 1-aminobenzene-2,5-disulfonic acid, 1-aminobenzene-2,4-disulfonic acid, 1,3-diaminobenzene-4-sulfonic acid, 1,4-diaminobenzene-2-sulfonic acid, 2-amino-5-methyl-benzenesulfonic acid, 5-amino-2,4-dimethylbenzenesulfonic acid, 4-amino-2-methylbenzenesulfonic acid, 3-amino-5-isopropyl-2-methylbenzenesulfonic acid, 2-amino-4,5-dimethylbenzene-sulfonic acid, 2-amino-4,5-dimethoxybenzenesulfonic acid, 5-amino-2-methylhenzene-sulfonic acid, 2-amino-5-ethylbenzenesulfonic acid, 1-aminonaphthalene-3-sulfonic acid, 1-aminonaphthalene-4-sulfonic acid, 1-aminonaphthalene-5-sulfonic acid, 1-amino-naphthalene-6-sulfonic acid, 1-aminonaphthalene-7-sulfonic acid, 1-aminonaphthalene-8-sulfonic acid, 2-aminonaphthalene-1-sulfonic acid, 2-aminonaphthalene-5-sulfonic acid, 2-aminonaphthalene-6-sulfonic acid, 1-aminonaphthalene-3,6-disulfonic acid, 1-amino-naphthalene-3,8-disulfonic acid, 2-aminonaphthalene-4,8-disulfonic acid 1,4-diamino-naphthalene-6-sulfonic acid, 3-amino-4-methoxybenzenesulfonic acid, 1-amino-2-methoxynaphthalene-6-sulfonic acid, 3-amino-4-hydroxybenzenesulfonic acid, 3-amino-6-hydroxy-benzene-1,5-disulfonic acid, 2-amino-5-hydroxynaphthalene-7-sulfonic acid, 2-acetamido-5-aminobenzcnesulfonic acid, 2-amino-5-(p-aminobenzoylamino)benzenesulfonic acid, 2-amino-naphthalene-5,7-disulfonic acid, 2-aminonaphthalene-6,8-disulfonic acid, 2-amino-5-benz-amido-benzenesulfonic acid, 4,4'-diaminothiodiphenylether-2,2'-disulfonic acid, Z-amino-4-carboxy-5-chloro-benzenesulfonic acid, 4-amino-3-carboxy-benzenesulfonic acid, 5-amino-3-sulfosalicylic acid, 2-((3-phenylethyl)-5-aminobenzenesulfonic acid, 1,2-bis[4-amino-2-sulfophenyl]ethane, 4,4'-diaminostilbene-2,2'-disulfonic acid, 4-aminostilbene-2-sulfonic acid, 4,4'-diamino-2'-methoxystilbene-2-sulfonic acid,4-aminodiphenylether-3-sulfonic acid,2-aminodiphenylther-4-sulfonic acid, 2-amino-2'-methyldiphenylether-4-sulfonic acid, 2-amino-4-chloro-4'-amyldiphenylether-5-sulfonic acid, 2-amino-4,4'-di-chlorodiphenylether-2'-sulfonic acid, 2-amino-4'-methyldiphenylsulfone-4-sulfonic acid, ~~~3~~93 2,5-diamino-2'-methyldiphenylether-4-sulfonic acid, benzidine-2,2'-disulfonic acid, 3,3'-dimethylbenzidine-6-sulfonic acid, benzidine-2-sulfonic acid, 2'-aminodiphenyl-sulfone-3-sulfonic acid, 5'-amino-2'-methyldiphenylsulfone-3-sulfonic acid, 2',5'-diamino-4-methyldiphenylsulfone-3-sulfonic acid, 3'-amino-4'-hydroxy-di-phenylsulfone-3-sulfonic acid, 3,3'-diaminodiphenylsulfone-4,4'-disulfonic acid, N-ethyl-aniline-4-sulfonic acid, N-methyl-2-naphthylamine-7-sulfonic acid, 2-aminoethanesulfonic acid, N-methyl-, N-ethyl-, N-propyl-, N-isopropyl-, N-amyl-, N-hexyl-, N-cyclohexyl-, N-octyl-, N-phenyl-, N-dodecyl- or N-stearyl-2-aminoethanesulfonic acid, 2-methyl-2-aminoethanesulfonic acid, cu-aminopropanesulfonic acid, w-aminobutanesulfonic acid, c~aminopentanesulfonic acid, N-methyl-y-amino-propanesulfonic acid, 1,2-diaminoethanesulfonic acid, 2-methylaminopropanesulfonic acid, and 2-amino-2-carboxyethanesulfonic acid.
Representative examples of starting compounds of formula (13) R
(13) ~~Z-'f-~')x OV]n Y
wherein W, m, Z, X', x', R2, y, V and n are as defined above, which compounds fall under formula (9), are:
2-sulfobenzoyl chloride, 3-sulfobenzoyl chloride, 4-sulfobenzoyl chloride, 3,5-disulfo-benzoyl chloride, 3-sulfophthaloyl chloride, 3,4-disulfophthaloyl chloride, 4-sulfophenyl-acetyl chloride, ~i-(4-sulfophenyl)propionyl chloride, 3-sulfo-6-methylbenzoyl chloride.
Some of the above starting compounds are known and can be prepared by methods which are known per se.
The preparation of the eligible compounds of formula (1) is described in more detail in US patent specification 3 665 031, Representative examples of compounds of formula (1) which are eligible for use in the practice of this invention are compounds of formula - to -R

(14) H ~ ~ X-C-N Z- (S03Mm R~
n ~~;39~3~3 wherein R, RI, R4 X, Z, M, m and n have the following meanings.

_ 203433 N N N N N
U

a. N
n x z x z x x I ~ I r r r °
o w y. I w I w I r ~J
x x x x x x x~ x x x x~
CSC CSC CS, CSC U U
x x x x x x U U U U U U
x °,,3 ~ °~,' :3 U
' c .a ~ ~ ~ N M ~ ~ ~D
U ~.

~:03~3~3 N N
U

Ci.
r, z x z x z x U
cn / ~ / ~ / / \
/
O O \ ~ ~ ~ ~ cpr~ U
N
p / ~ / ~ O O O U
/ \ \ / / ~
O \ ( ~ ~ ~ ~ ~ ~ \
O O
U U
v x x x x x x x ~ ~' x x~ x~
CSC CSC U U CSC CSC
x x x x x x U U U U U U
v a .'., x~

:~ ::
c~ oo Q\
E-. U a, ;~o;~~~:~~

oo ~ C N N N

U

N
n .w .-r x z x z x i ~ o ( o ~ ~ ~

w ~ ~ ~ ( ~ w ~o N

v x x x x x x~ ~' x~ x' x~.

U CSC U CS, ..

N

x x x x U U U U

a a w ..

O _N

C~

U

w M Wit' ~ ~O t'~

.-r .-r rr .-.v ,-r F.U a.

i~~..~~~~~
N N N
G
O_O O O
p" N N N N
N /~ /~ A
a w w w w w ~ w .~ rr ..~ .~ .--mr x z x x z x x x i /
~ / ~ \
O O ~ / / / \
x x \ \ ~ \ ~ \ ~ / \
p N N v U U
M M
v v x x x x x x ~' cxS' ~' ~ x x U U CSC
x x x x x x x x U U~ U U U U U U
Id IA IJ 1.~ 1.1 Ir V N
CV

v .r ... ~., .J .r ., .r NO N N N N N
E~ U °a, 20:~43~3 - is -U

N N
w w ~ w v N
r x x x z i ~ / ° ~ ~ \
O
\ \ ~ / ~ x \ /
M
o \ I / x N U
x x x x N
n N
n x x x x U~ U U U~ U
a a v c _O N
a p b N N N N

_ 2034a~~3 U

n x x x x U
O
/ ~ \) \ ~ / z v / \ \
O Z ~ U
O ~ / p cpn N Z /
/ V
O \
v x x x x ~' x x~
U CSC C~ U
o~ o.
U U
a ..

~ C ~~ N M
M M M M
U °a.

;~o~~~s;~

n ° n N
x = x x x Z
N
O
O O ~~ c~
/ ~ \ cn / \ / \
U U
O U U \ / \ / \
N
M
v x x x x U U U
x x x x x U U~ U U U
a ...
c a a~
M M M M M
U a.

2~3~3~~
~ c U

~;, o ~ o_ N N
x x x x z a o / ~ ~ , ~ ~ i w ~ i w i \ i o ( ~
N ~ c~
x x v x x x x x x '' x ~: U U~ U x U
U

n x ad ~' ~' ~' U

,b H U ~.

203~~03 as well as the compounds of formulae SO ~ ~C2H5)3 H
(45) HO ~ ~ NH- C ~ ~ ~d 7~m~ 284 nm OH
(46) / \ C~ NH ~ ~ S03H

m.p. 190°C
The compounds of formula (1) are applied from an aqueous bath which contains the compounds in an amount of 0.01 to 10 % by weight, preferably 0.25 to 3 % by weight.
The application of the water-soluble phenolic antioxidant can be made during or after dyeing by an exhaust or continuous process. Application during dyeing is preferred.
In the exhaust process, the liquor to goods ratio may be chosen within a wide range, typically from 1:3 to 1:100, preferably from 1:10 to 1:40. The process is conveniently carried out in the temperature range from 30 to 130°C, preferably from 50 to 95°C.
In the continuous process the pick-up is conveniently 40-700 % by weight, preferably 40-500 % by weight. The fabric is then subjected to a heat treatment to fix the dyes and the antioxidant. Fixation can also be effected by the cold pad-batch process.
The heat treatment is preferably made by steaming in a steamer with steam or superheated steam in the temperature range from 98 to 105°C for typically 1 to 7, preferably 1 to 5, minutes. Dye fixation by the cold pad-batch process can be effected by storing the impregnated fabric, which is preferably rolled up, at room temperature (15 to 30°C) for typically 3 to 24 hours. It is common knowledge that the batching time depends on the dye.

~0;~~~9~

Upon completion of the dyeing process and fixation, the dyeings are washed and dried in conventional manner.
The dyeings obtained in the process of this invention have good thermal and/or photochemical stability.
Dyeings to be stabilised by the process of this invention are suitably those obtained with disperse, acid or metal complex dyes, preferably with azo dyes or 1,2-metal complex dyes such as 1:2-chronnium complex dyes, 1:2-cobalt complex dyes or copper complex dyes.
Preferred dyeings, but without implying any restriction thereto, are those obtained with red dyes or with dye mixtures containing a red component. Examples of such dyes are listed in the Colour Index, 3rd edition, 1971, Volume 4.
Polyamide material will be understood as meaning synthetic polyamide such as polyamide 6, polyamide 66 or polyamide 12, as well as modified polyamide, for example basic dyeable polyamide. In addition to pure polyamide, blends of polyurethane and polyamide are also particularly suitable, for example tricot fabric of polyamide/polyurethane in the ratio of 70:30. In principle, the pure or blended polyamide material can be in any form of presentation, for example fibres, yarn, woven and knitted goods, nonwovens or pile fabric.
Especially suitable for treatment by the process of this invention are dyeings on polyamide material which is exposed to light and/or heat, for example carpets or automotive fabric.
The process is also suitable for heat stabilising dyed polyamide material intended for the "moulding" process. In this process the fabric is moulded briefly at elevated temperature (for example in brassiere manufacture) The invention is illustrated by the following Examples, in which parts and percentages are by weight.
Example 1: Two polyamide 6 knitwear samples, each weighing 10 g, are dyed in an ~AHIBA dyeing machine at a liquor to goods ratio of 1:30. For dyeing, two liquors are prepared comprising 0.5 g/1 of monosodium phosphate and 1.5 g/1 of disodium phosphate (= pH 7) and 0.2 % of the dye of formula 203~39~

so,N~
H N - Sp2 ( 100) cH3 (red) N N
NHZ
in dissolved form.
Liquor (1) contains no further ingredients, but liquor (2 contains) 1 % of the compound of formula (lOl) CHZ CHZ CONH

Dyeing is commenced at 30°C and this temperature is kept for 10 minutes and then raised by 2~°/min to 95°C. After a dyeing time of 20 minutes at 95°C, 2 % of acetic acid ($0 %) is added and dyeing is continued for 20 minutes. After cooling to 50°C, the fabric samples are rinsed, centrifuged and dried.
The dyeings are tested for their lightfastness according to SN-ISO 105-B02 (Xenon) and DIN 75 202 (Fakra) and also for their shade stability in a heat test for 60 seconds at 130°C
in a circulating air drier.
Results:
Lightfastness Beat test Dyeing XENON 130C; 60 h FAKRA

h 1 -7 -4 dull brownish pale red 2 7 -6-7 brilliant pale red ;~o~~~o~

It is evident from these results that compound (101) affards the dyeing photochemical as well as thermal protection.
Example 2: The procedure of Example 1 is repeated, using in place of the dye of formula ( 100) 0.4 % of the dye of formula (2~) ~ ~ N = N N = N ~ ~ NH ~ ~ (navy blue) S03Na ~ S03Na Testing gives the following results:
Dyeing Lightfastness Heat test XENON 130C; 60 h FAKRA

h 3 4 < 4 grey*

4 4-5 4 blue;trace greyer than origina *dye destroyed It is evident that compound (101) affords the dyeing in particular thermal protection.
Example 3: The procedue of Example 1 is repeated, using in place of the dye of formula (100) 0.15 % of the dye of formula HO
OH
(300) ~ N = N ~ ~ 1:2 Co complex (bordeaux) The tests for lightfastness and heat stability gives the following results:

2U~3~:~~3~~

Lightfastness Heat test Dyeing XENON 130C; 60 FAKRA h h S 7-8 4 *light brown 6 7-8 -7 almost unchange *dye destroyed Here too a stabilisation of the dye against light and heat is observed.
Example 4: Two polyamide 6 knitwear samples, each weighing 10 g, are dyed beige in an ~AHIBA dyeing machine at a liquor to goods ratio of 1:30. For dyeing, two liquors are prepared comprising 0.5 g/1 of monosodium phosphate and 1.5 g/1 of disodium phosphate (= pH 7) and 0.2 % of the mixture of dyes, in dissolved form, comprising U.04 % of the dye of formula (100) as indicated in Example 1, 0.08 % of the dye of formula 0) ~ N=N ~ ~ N:N ~ ~ OCH3 (yellOW) S03Na 0.08 % of the dye of formula O NHZ
~sNa (401 ) (blue) O NH ~ ~ CH3 SOZ NHCHZCHZOH
Liquor (1) contains no further ingredients, but liquor (2) contains 1 % of the compound of formula ;~o~~~o~

(402) CHZ CH2 CONH ~ ~ SO3H
The test results are as follows:
Dyeing Lightfastness Heat test XENON 130C; 60 FAKRA h h 7 5-6 1-2 - olive green 8 ~ ~ -unaltered 5-6 2-3 beige The results show that the addition of compound (402) effects in addition to a hot light stabilisation in particular a heat stabilisation of the red dye of formula (100).
Example 5: Five polyamide knitwear samples, each weighing 10 g, are each dyed separately as described in Example 1 with the following combination of 0.002 %
of the dye of formula (300) as indicated in Example 3 and 0.04 % of the mixture of dyes of formulae (402) and (403), and of 81 pans of the dye of formula OH HO OH HO
(500) Na03S ~ ~ N-N ~ --~ + OCH3 ~ ~ N=N
N~N
1:2 Cr complex and 12 parts of the dye of formula ~0~~;~9~

(501) ~ ~ N=N ~ ~ 1:2 Co complex.

Dyebath 1 contains no further ingredients, whereas baths 2-6 each contain 1 %
of the compounds of formulae (502)-(506) in dissolved form.
S03Na (502) H ~ ~ CH2-CH2-CONH
O
(503) H / \ CONH ~ ~ S03Na (504) H ~ ~ CH2- CH2- CONH ~ ~ S03Na ~34393 (505) CH2-CH2-CON-CH2-CH2-S03Na (506) H ~ ~ CHZ- CH2- CONH- CHZ ~ ~ S03Na The dyeings are tested for their lightfastness properties according to DIN 75 (FAKRA), for their loss of mechanical properties (test according to SN
198.461), and for their heat stability. The following results are obtained.
Dye- Lightfastness* tensile Heat test strength/elong-ation bath FAKRA in % 130C, 60 h FAKRA

72 after h 216 144 h Fakra h 1. 2 H 1 H 2.9 22.4** change in shade from grey -~ beige 2. 4-5 3 62.4 77.0 3. 3-4 1-2 46.2 63.8 all grey dyeings a 4. 4-5 3-4 64.2 79.4 trace more yellow 5. 4-5 3 62.0 77.1 no destruction of 6. 4-5 3-4 52.3 72.5 dye *evaluation against Grey Scale: **material spoiled It is evident from the results that the grey dyeings are markedly improved by the compounds (502)-(506) with respect to their photochemical and thermal stability.

~U3~393 Example 6: Two polyamide 66 tricot samples are dyed violet as described in Example 1 with the following amounts of dye: 0.15 % of the dye of formula (100) as indicated in Example l and O.U75 % of the dye of formula (401) as indicated in Example 4.
Dyebath 1 contains no further ingredients, whereas dyebath 2 additionally contains 1.5 %
of the compound of (402) as indicated in Example 4.
The thoroughly rinsed and dried tricot material is subsequently subjected to a heat treatment under "moulding" conditions (i.e. a heat moulding process used e.g.
for making brassieres). This is done by heating the material under controlled conditions on a precision ironing press "System BASF" (sold by K. Schroder KG, D-Weinheim / Bergstr.).
The test results are as follows:
Press Shade compared with original Temp./Time dyeing 1 dyeing 2 190C; 1 min a trzce dullerno change 200C; 1 min markedly dullerno change 210C; 30 duller no change sec.

210C; 1 min much duller a trace duller The results of the accelerated contact heat treatment show that the dyeing containing compound (402) exhibits no or only an insignificant tendency to changes in shade (= dye deswction).

Claims

1. A process for improving the thermal and/or photochemical stability of dyeings on polyamide fibres, which process comprises applying to said polyamide fibres, from an aqueous medium, a compound of formula (1) (1) (A-Y-)n Z(-W)m wherein A is the radical of a sterically hindered phenol of the benzene series;

Y is a radical of formula (2) or (3) wherein X and X' are each independently of the other alkylene, oxaalkylene or thiaalkylene;

R2 and R3 are each independently of the other hydrogen or an unsubstituted or substituted alkyl group containing 1 to 18 carbon atoms, and x, x' and y are each independently of the other 0 or 1;

Z is an aliphatic or a carbocyclic aromatic radical, which last mentioned radical contains not more than two mono-or bicyclic nuclei;

W is a sulfa group; and m and n are each independently of the other 1 or 2, or a water-soluble salt thereof, wherein the compound of formula (1) goes on to the fibres by an exhaust or continuous dyeing process.

2. A process according to claim 1, which comprises the use of a compound of formula (1);

wherein A is a monohydroxyphenyl radical which is substituted in one or both of the ortho-positions to the hydroxyl group by alkyl of 1 to 12 carbon atoms, cycloalkyl of 6 to 10 carbon atoms or aralkyl of 7 to 10 carbon atoms, and which may carry additional substituents.

3. A process according to either claim 1 or claim 2, which comprises the use of a compound of formula (1), wherein A
is a radical of formula (4) wherein R and R1 are each independently of the other hydrogen, methyl or tert-butyl, .and the sum of the carbon atoms of R and R1 is not less than 2.

4. A process according to any one of claims 1 to 3, wherein X and X' in the compounds of formulae (2) and (3) are straight-chain or branched alkylene of 1 to 8 carbon atoms.

29a

5. A process according to any one of claims 1 to 4, wherein R2 and R3 in the compounds of formulae (2) and (3) are straight-chain or branched C1-C8alkyl.

6. A process according to any one of claims 1 to 4, wherein R2 and R3 in the compounds of formulae (2) and (3) are hydroxyalkyl, alkoxalkyl, aminoalkyl, alkylaminoalkyl or dialkylaminoalkyl, each containing a total of 2 to 10 carbon atoms, or are phenyl.

7. A process according to claim 1, wherein Y in formula (1) is a radical of formula (5) wherein R4 is hydrogen or C1-C4alkyl and X" is C1-C4alkylene.

8. A process according to any one of claims 1 to 7, wherein Z in formula (1) is the radical of an unsubstituted or carboxy-substituted lower alkane of 2 to 5 carbon atoms, the radical of an unsubstituted benzene nucleus or of a benzene nucleus which is substituted by chlorine or bromine, C1-C4alkyl, C1-C4alkoxy, C1-C4alkoxycarbonylamino, hydroxy, carboxy, phenylethyl, styryl, phenyl, phenoxy, phenylthio, phenylsulfonyl or acylamino, and the group W may be attached direct to said benzene nucleus or to a monocyclic aryl radical of one of the substituents thereof, or is a radical of a naphthalene or tetraline nucleus.

9. A process according to claim 1, which comprises the use of a compound of formula (7) wherein R and R1 are each independently of the other methyl or tert-butyl, R4 is hydrogen or C1-C4alkyl, X" is C1-C4alkylene, Z is ethylene, a divalent or trivalent radical of benzene or naphthalene or is a divalent radical of diphenyl ether, W is the sulfo group, and n is 1 or 2.

10. A process according to claim 9, which comprises the use of a compound of formula (7), wherein R and R1 are tert-butyl, X" is methylene or ethylene, R4 is hydrogen, methyl or ethyl, and Z is ethylene, o-, m- or p-phenylene, 1,4-naphthylene, 1,8-naphthylene, 2-methoxy-1,6-naphthylene, 1,5-naphthylene, 2,5-naphthylene, 2,6-naphthylene, 1,4,6-naphthalenetriyl or the radicals and wherein the sulfo group W may also be in the form of its alkali meal salts or ammonium salts.

11. A process according to any one of claims 1 to 10 for improving the thermal and/or photochemical stability of polyamide fibres dyed with acid or metal complex dyes.

12. A process according to claim 11 for improving the thermal and/or photochemical stability of polyamide fibres dyed with red acid or 1:2 metal complex dyes or with a mixture of dyes containing a red component.

13. Dyeings on polyamide fibres treated by the process as claimed in any one of claims 1 to 12.