US2025618A - Dyeing leather - Google Patents

Description

Patented Dec. 24, 1935 UNITED STATES PATENT OFFICE DYEING LEATHER.

No Drawing. Application November 22, 1934,

Serial No. 754,870. In Germany December 3, 1

4 Claims.

This invention is an improvement in or modification of that described in the specification of a patent application Ser. No. 754,369 filed by the same inventor on the same day. That specifica- 5 tion relates to the application of a certain group of amino-azobenzene-dyestuifs for dyeing leather, especially chrome leather, throughout.

According to the present invention, leather, especially chrome leather, can be through-dyed to a substantial degree or even completely by using instead of the dyestuffs used in the aforesaid specification amino-azobenzene sulphonic acids containing in the residue of the coupling component an amino-group substituted by a monoor poly- 15 hydroxyalkyl group. Hitherto N-hydroxyalkylated acid azo-dyestuifs have been used only for dyeing textile fibres.

The yellow azo-dyestufis hitherto used for dyeing leather, such as Orange II from diazotized sulphanilic acid and B-naphthol (Schultz Farbstofftabellen, 6th edition, No. 139) or Metanil Yellow Extra from diazotized metanilic acid and diphenylamine (Schultz, No. 134) or thenitrated azo-dyestufi from diazo-sulphanilic acid and diphenylamine (Schultz, No. 141) are capable of dyeing chrome leather only superficially. In contrast thereto the dyestuffs used in accordance with the invention penetrate deeply into the leather and in most cases they dye it completely through. Leather, especially chrome leather, which has been dyed in accordance with the invention has great advantages. Its section is dyed throughout so that undyed portions are not exposed by damage to the surface or by wear during use.

Only a few dyestuffs which are capable of penetrating deeply into the interior of the hide or of dyeing chrome leather throughout have hitherto been known; for example, the yellow mono-azodyestuffs which are obtained from diazotized 2- chloro-4-amino l methylbenzene 6 sulphonic acid and resorcinal or a substitution product or homologue thereof dye chrome leather completely through. By the provision of a whole series of dyestuffs which are capable of penetrating into the interior of the leather without the addition of alkali and of dyeing it through to a substantial Dyeing prescription 55 The neutralized hides are dyed in the cask with 150-200 per cent of water at a temperature of 65 C. The cask is set in motion and a solution of the dyestuff is introduced through the hollow axle of the cask. After 45 minutes the fat liquor is added and the cask isthen kept in motion for a further 45 minutes. In the case of particularly heavy hides the duration of the dyeing must be suitably prolonged. In general a quantity of dyestuff amounting to 1-2 per cent of the weight of the material sufiices for producing powerful through-dyeings.

The dyestuffs used in accordance with the invention may be made by the usual method, which is illustrated in the following examples. In these examples and in the table are described the production, composition and dyeing properties of a number of representatives of the group of dyestuffs of the amino-azobenzene series, but it will be understood that this does not exhaust all the possibilities within the scope of the invention.

In the following examples the parts are by weight:-

Example 1 173 parts of 3-aminobenzene-1-sulphonic acid are diazotized in the usual manner and the diazosolution is combined at 0-3 C. with 181 parts of dihydroxy-ethyl-aminobenzene which has previously beendissolved by means of the quantity of hydrochloric acid required to produce a solution which is faintly acid to Congo. The reaction is maintained 'faintly acid to Congo by addition of a solution of sodium acetate. When the formation of the dyestufi is finished the solution is made weakly alkaline by the addition of sodium carbonate, heated and the dyestuff precipitated by salting out. The dyestuff is a yellow crystalline powder which dyes leather, especially chrome leather, according to the foregoing prescription a powerful yellow throughout. The dyestufi of this example has the following formula:

' (EH40 H S 03 Example 2 127.5 parts of Z-chloro-l-aminobenzene are diazotized in the usual manner and the diazocompound is coupled in a medium acid with acetic acid with 261 parts of 3-dihydroxy-ethylaminobenzene-l-sulphonic acid. When coupling is finished the dyestufi is isolated by salting out after the solution has been made alkaline with sodium carbonate. The dyestufi is a yellow powder which dyes chrome leather a powerful yellow both on the surface and in the interior. The dyestufl of this example has the following formula:

0 1 so. Gin H Example 3 CgHgOH The dyestufl of mula Example 4 218 parts of 5-nitro-2-aminobenzene-l-sulphonic acid are diazotized with the required quantity of nitrite and hydrochloric acid and the diazo-compound is coupled with 215.5 parts of 3-chloro-1-dihydroxyethylamincbenzene in a solution which is faintly acid to Congo. addition of sodium acetate the reaction is maintained faintly acid to Congo throughout the coupling. When the formation of the dyestufi" is finished the solution is rendered alkaline by the addition of sodium carbonate and the dyestufl is isolated in the usual manner. It is obtained in the form of a dark red powder which dyes chrome leather deep Bordeaux red shades on the surface and dark red-violet shades in the interior. The dystuff of this example has the following for- By the Table Dyestufl. Dyeing on leather Diem-component ,Azo-component 0n the surface In the interior 2 chloro- 1 aminobenzene 3 dioxyethylamino benzene 1 sulphonic P werful yellow. Powerful yellow, 2:5 dichloro 1 aminobenzene; 3 P dio xyethylemino benzene l sulphonic Deep orange Deep orange.

3:4 dlchloro l eminobenzene..

Z-nitro-l-eminobenzene 3-nitro-l-aminobenzene 4-nitro-l-eminobenzen 4-nitro-l-aminobenzene. l-chloio-Z-nitro-l-aminobenzene...

2:6 dichloro -4 nitro l amino benzene. 2:4-dinitro-1-eminobenune 3-nitro-4-emino-1-methylbenzene l-nitro-Z-amino-l-methoxybenzene. 4-nitro-2-amino-1-oxyetbyloxybenzene. 3-nitro-4-amino-1-ethoxybenune.

6-nitro-3-amlno-4-methoxy-1- methyl-benzen e. 3-eminobenzene-lm1lphonio acida amihobenzene-l-eolphonio mid. Hminobenzene-l-sulphonlo acid- 4-emlnobenzene-l-sulphonio acid. 4-ehloro-2-aminobenune- 1- mlphonlc acid. o-ohioro-3-aminobenune- 1- mlphonic acid. 2:5-dichloro-4eminobenzene-lml honio aicd. 2' hloro -3- aminobenune leulphonic acid. 3-nitro-4-eminobennene l sulphonic acid. 4-nitro-2-eminobenune 1 eulphonio b-nitro-z-eminobenzene 1 sulphonic acid.

Powerful orange-yellow.

Brownish-orenge--- Orange-yellow Powerful yellow Pele Bordeaux red Powerful brownish-red Brown-orange Pale yellow-brown 3 {:liidxyethyhmino benzene 1 sulphonic Red-violet--- s dloxyetbylemino-benzene-l-sulphonic acid..- Reddish-yellow 3-dioxyethyleminobenzene-l-sulphonic acid. Brownish-orange 3-dioxyethylamino-benzene-l-sulphonic acid.-. Brownish-orenge B-dioxyethylemino-benzene-l-mlphonic acid--. Orange-brown a-dioxyethylemino-benzene-l-sulphonic acid--- Dark red-brown Dloxyethylemino-benzene Pure yellow admin? 2%,?mei-miltttreu::: nfiddfih ififi lx:::::::::::

Di-(p: -dioxy)-propyleminobenzene Powerful reddish-yellow 3-di g c-yggioxy) ethylaminobenzene -1 sul- Pale brownish-orange -(p= y-dioxy) etbylamfn'obenzene 1 sul- Brownian-orange D 25 m yypropyleminobenzeneh Brownorange a-N-ethyloxy-ethylamino-benzene-l-eulphonio Brownish yeilowoi'fieeyfmm Dull yellow a-oxyethylamino-bmethylbenzene Brown-yellow a-dioxyethylemino-l-methyl-benzene Orange-brown f-ehloro-Z-dloxy-ethylemino-l-methoxybenzene Brown-yellow 3-dloryethylamino-l-oxy-benzene; Powerful brownish-yellow...

3-m-hyloxyethylamlnobenzene -l sulphonio Deep Bordeaux red Oxyethylamin- Violet-bro" Powerful orange-yellow Powerful brownish orange. Orange-yellow.

ow. Orange-brown.

pure yel- Brownish-orange.

Powerful brownorange.

Powerful brownish yellow.

Brownish yellow.

Powerful brownorenge.

Deep orange-brown.

Brown-yellow.

Powerful brownish yellow.

Deepredviolet.

Violet-brown.

aeeaere 3 Dyestufi Dyeing on leather Diem-component Azo-component 0n the surface in the interior 2.4 5 nitro 2- aminobenzeuo 1 Dioxyethjriaminohenaene- Pure Bordeaux red i-Poweriui Bordeaux sulphonic acid. red. 35 5 nitrg 2 ernnobenzene 1 fl-oxyethyiamino-l-methylbenzene Bordeaux red Bordeaux red.

su p omc ac: E5 5 nitro 2 aminobenzene 1 3-11ioxyethyiamino-l-methyibenzene Bordeaux red Deep dark-violet.

suiphonic acid. 1, Q 37 5-111i1tro -2-an1inobenzene-1 -suia-di-(fi: -dioxy)-px-opylamino-1-methyihen- Pele Bordeaux red r- Bordeaux red.

p onic aci cane. 38 5-nli tro;2-a 1(1 1inobenzene-1-sn1- 3 chiorodioxyethyi-aminobenzene Deep Bordeaux red" Dark red-violet.

p omc 801 39 fi-ngtro-Z-arafinobenzenml-sui- 3-ch1orodi-(fl: 'y-dioxy)-propyi-aminobenzene Bordeaux red Deep Bordeaux red.

p 01110 e01 40 5-nlgtroflerginobenzene-i-snili-oxyethylemino-e-methoxy-1-methyibenzone Violet-brown Deep violet-brown. W1 5 p 01.110 801 v .i 11 5-nitro-2-aminobenzene- 1- sul- 3-dioxyethyiamino-4-methoxy-1-methy1ben- Grey-brown Grey phonic acid. zone. 42 5-nitro-2-aminobenzene-i-sul- 3-di-(fi: v-dioxy) -propylamino-4 -methoxy-1- Red-brown. Rod-brown.

phonic acid. methylbenzene. 43 5 nitro 2 aminobenzene i sul- 2-dioxyethyiamino-iz-dimethylbenzene Yellow-brown. Brown-violet.

phonic acid.

What 1 claim is:-

1. A process for dyeing leather, wherein the leather is dyed with an amino-azoioenzene sulphonic acid dyestufi of the following general formula:

wherein X1 represents H or SOaH; X2 represents H, N02, Cl, CH3 or OR (R being methyl, ethyl or hydroxyethyl) X3 represents H, N02, C1 or CH3; X4 represents H or N02, with the restriction that at least one of said X1, X2, Ya and m must be other than hydrogen; Y1 represents H or SOsH; Y2 represents H, CH3, C1 or OH; Y3 represents H, CH3 or OCHa; R1 represents H, ethyl, hydroxyethyl or dihydrozypropyi; and R2 represents hydroxyethyl or o'lihydroxypropyl.

2. A process for dyeing leather, wherein the leather is dyed with a. dyestuff from diazotized 4-nitro-2-aminobenzene-1-su1ph0nic acid and 3- hydroxyethyiamino-l-methylbenzene, having the formula:

3. A process for dyeing leather, wherein the ieather is dyed with a dyestufi from diazotized 3-aminohenzene-i=suiphonic acid and dihydroxy= ethyiaminohenzene, having the formula:

25 canon NN P \\-N/ CalhOH e0 4. A process for dyeing leather, wherein the leather is dyed with a dyestuff from diazotized 3- aminobenzene-i-suiphonic acid and di- (pw-dihydroxy) -propy1aminobenzene, having the formula:

5 /on,.onon.cmon u GH:.CHOH.CH2OH 0:11

mm- SENN.