EP0187473B1 - Verfahren zur Gerbung von Häuten - Google Patents

Verfahren zur Gerbung von Häuten Download PDF

Info

Publication number
EP0187473B1
EP0187473B1 EP85308779A EP85308779A EP0187473B1 EP 0187473 B1 EP0187473 B1 EP 0187473B1 EP 85308779 A EP85308779 A EP 85308779A EP 85308779 A EP85308779 A EP 85308779A EP 0187473 B1 EP0187473 B1 EP 0187473B1
Authority
EP
European Patent Office
Prior art keywords
hides
tanning
hide
titanyl sulphate
bath
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP85308779A
Other languages
English (en)
French (fr)
Other versions
EP0187473A1 (de
Inventor
Sergio Vanni
Loris Guidi
Paolo Vallini
Renato Casimiro Pace
Domenico Camaioni
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Montedison SpA
Original Assignee
Montedison SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Montedison SpA filed Critical Montedison SpA
Publication of EP0187473A1 publication Critical patent/EP0187473A1/de
Application granted granted Critical
Publication of EP0187473B1 publication Critical patent/EP0187473B1/de
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C14—SKINS; HIDES; PELTS; LEATHER
    • C14C—CHEMICAL TREATMENT OF HIDES, SKINS OR LEATHER, e.g. TANNING, IMPREGNATING, FINISHING; APPARATUS THEREFOR; COMPOSITIONS FOR TANNING
    • C14C3/00—Tanning; Compositions for tanning
    • C14C3/02—Chemical tanning
    • C14C3/04—Mineral tanning
    • C—CHEMISTRY; METALLURGY
    • C14—SKINS; HIDES; PELTS; LEATHER
    • C14C—CHEMICAL TREATMENT OF HIDES, SKINS OR LEATHER, e.g. TANNING, IMPREGNATING, FINISHING; APPARATUS THEREFOR; COMPOSITIONS FOR TANNING
    • C14C3/00—Tanning; Compositions for tanning
    • C14C3/02—Chemical tanning
    • C14C3/28—Multi-step processes

Definitions

  • This invention relates to a process for tanning hides. More particularly, the invention relates to a process for tanning hides for vamps and peltry, by means of ammonium titanyl sulphate.
  • ammonium titanyl sulphate can be utilized as a tanning agent for hides. It has been proposed to subject delimed hides to a pretreatment with an activating substance, for example phthalic anhydride; tanning follows, with the ammonium titanyl sulphate, and alkaline substances are then added to the bath, and tanning can be completed with synthetic organic tanning agents.
  • an activating substance for example phthalic anhydride
  • tanning causes in the hides an acid swelling, which is irreversible and renders the tanned hide brittle.
  • the ammonium titanyl sulphate tends to precipitate in the form of titanium hydroxide, which adversely affects the qualitative constancy of the article and gives rise to losses of the tanning agent.
  • the present invention aims to provide a process for tanning hides, particularly for vamps and peltry by using ammonium titanyl sulphate, which process avoids acid swelling of the hides, thus imparting to the tanned leather a higher tearing resistance.
  • the invention also aims to provide a process in which the ammonium titanyl sulphate is practically fully absorbed by the hides, with consequent both economical and ecological advantages, as practically no titanium compounds are discharged along with the residual waters.
  • a further aim of the invention is to provide a process capable of producing a tanned hide having a high compactness (hide of closed texture), with good stretch recovery (firm hide) and free from blowings (loose grain).
  • the present invention provides a process for tanning hides, in particular a process for the tanning of hides for vamps and peltry by means of ammonium titanyl sulphate.
  • This process comprises the consecutive steps that delimed hides are treated, in the presence of water, with ammonium sulphate and naphthalene sulphonic acid; ammonium titanyl sulphate is added to the bath, while maintaining the temperature at not more than 40°C; a complexing agent for tetravalent titanium ion is optionally added, maintaining the temperature at not more than 40°C; the bath is graudally made alkaline by repeatedly adding (adding batchwise) sodium sulphite and hexamethylenetetramine until there is obtained a pH value in the hide of from 4.0 to 5.0, while maintaining the temperature at not more than 40°C; the hides are removed from the bath and are allowed to rest; the hides are pressed, sheared (shaved) and washed with water; the
  • the final titanium content of the bath is very low, and does not normally exceed about 0.3 g/liter (calculated as Ti0 2 ), so that tanning agent losses do not practically occur and the discharging of the bath does not practically give rise to ecological problems deriving from the presence of titanium.
  • ammonium titanyl sulphate and a method of preparing the same are described in French patent No. 2,042,206. Another preparation method is described in Italian patent application No. 20571 A/83.
  • the ammonium titanyl sulphate utilized in the present invention is not subjected to the stabilizing treatment described in French patent No. 2,042,206.
  • the naphthalene sulphonic acid utilized in the first step of the process of the invention may be the alpha-naphthalene sulphonic acid or beta-naphthalene sulphonic acid, or mixtures thereof.
  • the tanning drum is generally rotated until the reagents have passed through the hide section before adding the ammonium titanyl sulphate.
  • ammonium titanyl sulphate calculated as TiO z , are preferably used, more preferably from 2% to 4% thereof. If no complexing agent is added, the tanning drum is rotated, after addition of ammonium titanyl sulphate, for a time generally ranging from 3 to 7 hours.
  • the tetravalent titanium ion complexing agent is preferably an alkali metal citrate or tartrate, for example of sodium or of potassium. As already explained hereinbefore, it can be added either after the ammonium titanyl sulphate or during the deacidification step or in both steps.
  • the total amount of alkali metal citrate utilized in one step or in both steps is preferably from 0.05 to 0.4 mole per mole of Ti0 2 contained in the ammonium titanyl sulphate; in the case of the alkali metal tartrate, such amount is preferably from 0.07 to 0.6 mole per mole of Ti0 2 .
  • the complexing agent is used in both steps, about 50-80% of such amounts are preferably added after the ammonium titanyl sulphate, the remaining amount being added during the deacidification step.
  • the complexing agent When the complexing agent is added during the tanning step with the ammonium titanyl sulphate, it is usually added when the tanning agent has substantially passed through the hide section, after about 2-4 hours. After addition of the complexing agent, the drum is usually rotated for 1 to 3 hours.
  • the alkalinisation step follows. Sodium sulphite and hexamethylenetetramine are gradually added batchwise to the bath, until there is obtained a pH value in the hide of from 4.0 to 5.0. Preferably, such pH is from 4.0 to 4.5. Usually, the addition of sodium sulphite and of hexamethylenetetramine occurs in 3-4 batches, for example at constant time intervals totally lasting about 6 hours.
  • the sodium sulphite:hexamethylenetetramine weight ratio is usually about 1: 1.
  • the alkali metal substance used in the deacidification step is preferably sodium bicarbonate or sodium sulphite. Deacidification is continued until there is obtained, in the hide, a pH value of from 5.0 to 6.5, preferably from 5.0 to 6.0. When a tetravalent titanium ion complexing agent is used during the deacidification step, it is usually added together with the alkaline substance.
  • the hides are then washed with water, after which there follows the step of completing the tanning with one or more synthetic tannins and/or a suitable polymeric material.
  • the synthetic tannin is preferably selected from phenol and formaldehyde sulphonated condensates and from naphthalene and formaldehyde sulphonated condensates.
  • the polymeric material for completing the tanning is preferably selected from polyurethane polymers, acrylic polymers and styrene-maleic polymers.
  • the bath is then discharged and the hides are dyed and greased according to conventional techniques.
  • the hides previously subjected to the usual liming, fleshing and delim- ing treatments, are introduced into a drum. All the amounts referred to below are indicated in per cent by weight with respect to the pelt weight of the hides, unless otherwise specified.
  • the temperature generally ranges from 20 to 25°C.
  • the drum is generally rotated until the reagents have passed through the hide section, which requires generally from 2 to 4 hours.
  • the pH of the bath generally ranges from 4.0 to 4.5.
  • ammonium titanyl sulphate calculated as Ti0 2
  • the drum is usually rotated during 3 to 7 hours. If the complexing agent is added, the drum is generally rotated, before introducing said agent, until the tanning agent has passed through the hide section, which takes generally 2 to 4 hours; when the complexing agent is added, in the case of alkali metal citrate, from 0.05 to 0.3 mole of citrate for each mole of Ti0 2 is generally used at this stage. After the complexing agent has been added, the drum is generally rotated during 1 to 3 hours.
  • the alkalinisation step terminates when the pH, in the whole section of the hide, is from 4.0 to 4.5. This generally takes 6 to 8 hours.
  • the bath is practically free from tetravalent titanium: its maximum residual concentration does not exceed 0.3 g of Ti0 2 per liter.
  • the temperature must not exceed 40°C.
  • the hides are taken out from the bath and are allowed to rest during a period of time generally varying from 24 to 28 hours.
  • the hides are then pressed, sheared and subsequently washed with about 300% of water at 30-35°C.
  • the deacidification treatment is generally carried on until the hide, in its entire section, has reached a pH value of from 5.0 to 6.0; this generally takes from 1 to 3 hours.
  • the drum is generally rotated until the reagent or the reagents has/have passed through the section of the hide; this generally takes from 2 to 3 hours.
  • the bath is discharged and the hides are dyed and greased according to conventional techniques.
  • the hides tanned by the process of the present invention exhibit a good tearing resistance. They are very compact, with good stretch recovery and free from blowings.
  • the delimed hides of 3 calves were placed into a tanning vessel (rotative drum).
  • the hides were treated with 120% of water' at 25°C, 3% of (NH 4 ) 2 S0 4 and 3% of commercial-grade naphthalene sulphonic acid. After a 3-hour rotation, the pH in the whole section of the hides was equal to 4.5.
  • the drum was discharged and the hides were allowed to rest during 48 hours.
  • the hides were pressed, sheared and washed with 300% of water at 30°C, whereafter deacidification was accomplished.
  • the hides were introduced again into the drum (sheared weight: 12 kg), and 200% of water at 35°C, 2% of sodium citrate and 2% of sodium bicarbonate were added.
  • the drum was rotated for 90 minutes; after which the pH value of the bath and of the whole section of the hide was equal to 6.0.
  • the bath was discharged, and the hides were washed with 300% of water at 35°C.
  • the complementary tanning step was then commenced. To this purpose, 150% of water at 30°C and 8% of a mixture of synthetic tannins, consisting of a naphthalene - formaldehyde sulphonated polycondensate and of a phenol - formaldehyde sulphonated polycondensate, was added. The drum was rotated during 2 hours. The hides were checked and a complete penetration was ascertained.
  • the bath was discharged and the hides were dyed and greased.
  • the resulting leathers were compact and relatively soft, not elastic, and did not give rise to blowings. They were suitable for vamps.
  • the delimed hides of 3 calves (pelt weight: 25 kg) were placed into a tanning drum and were treated as in Example 1 until completion of the tanning step with the ammonium titanyl sulphate. 8 kg of sheared hides were then deacidified by addition of 200% of water at 30°C and of 1.8% of sodium sulphite. The drum was rotated for 2 hours. The bath and the whole section of the hides exhibited a pH value of 5.8.
  • the complementary tanning step was carried out. To this purpose, 150% of water at 30°C, 5% of a synthetic tannin consisting of a sulphonated polycondensate of naphthalene and formaldehyde, and 4% of acrylic resin were added.
  • the resulting leathers were compact and soft and did not give rise to blowings. They were suitable for vamps and soft bag articles.
  • the delimed hides of 4 calves were placed into a tanning drum.
  • the hides were treated with 120% of water at 25°C, 2.5% of (NH 4 ) 2 S0 4 and 2.5% of commercial-grade naphthalene sulphonic acid. After a 3-hour rotation the pH of the bath and of the entire section of the hides was equal to 4.3.
  • the resulting leathers were compact, not elastic and did not give rise to blowings. They were suitable for the manufacture of suit-cases and bags.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Treatment And Processing Of Natural Fur Or Leather (AREA)

Claims (13)

1. Verfahren zur Gerbung von Häuten, umfassend die aufeinanderfolgenden Stufen der Behandlung der entkalkten Häute in Anwesenheit von Wasser mitAmmoniumsulfat und Naphthalinsulfonsäure; der Zugabe von Ammoniumtitanylsulfate, wobei die Temperatur auf nicht höher als 40°C gehalten wird; gegebenenfalls der Zugabe eines Komplexierungsmittels für das 4-wertige Titanion, wobei die Temperatur auf nicht höher als 40°C gehalten wird; der schrittweisen alkalisch-Machung des Bades durch absatzweise Zugabe von Natriumsulfit und Hexamethylentetramin, bis in der Haut ein pH von 4,0 bis 5,0 erhalten wird, während die Temperatur auf nicht höher als 40°C gehalten wird; der Entfernung der Häute aus dem Bad und dem Stehenlassen derselben; dem Pressen, Scheren und Waschen der Häute mit Wasser; der Entsäuerungsbehandlung der Häute mit einer alkalischen Substanz in Anwesenheit von Wasser und gegebenenfalls in Anwesenheit eines Komplexierungsmittels für das 4-wertige Titanion, wobei eine derartige Behandlung fortgesetzt wird, bis in der Haut ein pH von 5,0 bis 6,5 erhalten wird; des Waschens der Häute mit Wasser; der Vervollständigung der Gerbung in Anwesenheit von Wasser mit einem oder mehreren synthetischen Tanninen und/oder einem polymeren Material für die Vervollständigung der Gerbung; und des Ausleerens des Bades und der Färbung und Einfettung der Häute; wobei das Komplexierungsmittel für das 4-wertige Titanion in wenigstens einer der zwei Stufen, in denen es erwähnte wurde, zugegeben wird.
2. Verfahren nach Anspruch 1, gekennzeichnet durch die Zugabe von 1 bis 4% Ammoniumtitanylsulfat, berechnet als Ti02, bezogen auf das Fellgewicht der Häute.
3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß das Komplexierungsmittel für das 4-wertige Titanion ausgewählt wird aus Alkalimetallcitraten und -tartraten.
4. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß die Menge des Alkalimetallcitrats, das während der Gerbungsstufe mit dem Ammoniumtitanylsulfat und/oder während der Entsäuerungsstufe eingeführt wird, insgesamt 0,05 bis 0,4 Mol Citrat/Mol des im Ammoniumtitanylsulfat enthaltenen Ti02 beträgt.
5. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß die Menge des Alkalimetalltartrats, das während der Gerbungsstufe mit dem Ammoniumtitanylsulfat und/oder während der Entsäuerungsstufe eingeführt wird, insgesamt 0,07 bis 0,6 Mol Tartrat/Mol des im Ammoniumtitanylsulfat enthaltenen Ti02 beträgt.
6. Verfahren nach irgendeinem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß, wenn das Komplexierungsmittel für das 4-wertige Titanion in der Gerbungsstufe mit dem Ammoniumtitanylsulfat zugegeben wird, dieses Komplexierungsmittel zugegeben wird, wenn das Ammoniumtitanylsulfat im wesentlichen durch den Hautabschnitt durchgegangen ist.
7. Verfahren nach irgendeinem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß die Naphthalinsulfonsäure ausgewählt wird aus alpha - Naphthalinsulfonsäure, beta - Naphthalinsulfonsäure und Mischungen davon.
8. Verfahren nach irgendeinem der Ansprüche 1 bis 7, gekennzeichnet durch die Zugabe von 1 bis 4% Naphthalinsulfonsäure und von 2 bis 4% Ammoniumsulfat, bezogen auf das Fellgewicht der Häute.
9. Verfahren nach irgendeinem der Ansprüche 1 bis 8, gekennzeichnet durch die Zugabe von Natriumsulfit und Hexamethylentetramin bis ein pH von 4,0 bis 4,5 in der Haut erhalten wird.
10. Verfahren nach irgendeinem der Ansprüche 1 bis 9, dadurch gekennzeichnet, daß die alkalische Substanz, die für die Entsäuerungsstufe verwendet wird, Natriumbicarbonat oder Natriumsulfit ist.
11. Verfahren nach irgendeinem der Ansprüche 1 bis 10, dadurch gekennzeichnet, daß die Entsäuerungsstufe fortgesetzt wird, bis in der Haut ein pH von 5,0 bis 6,0 erhalten wird.
12. Verfahren nach irgendeinem der Ansprüche 1 bis 11, dadurch gekennzeichnet, daß das synthetische Tannin ausgewählt wird aus sulfonierten Kondensaten von Phenol und Formaldehyd und sulfonierten Kondensaten von Naphthalin und Formaldehyd.
13. Verfahren nach irgendeinem der Ansprüche 1 bis 12, dadurch gekennzeichnet, daß das polymere Material zur Vervollständigung der Gerbung ausgewählt wird aus Polyurethanpolymeren, Acrylpolymeren und Styrol - Malein - Polymeren.
EP85308779A 1984-12-03 1985-12-03 Verfahren zur Gerbung von Häuten Expired EP0187473B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT23870/84A IT1178688B (it) 1984-12-03 1984-12-03 Procedimento per la concia delle pelli
IT2387084 1984-12-03

Publications (2)

Publication Number Publication Date
EP0187473A1 EP0187473A1 (de) 1986-07-16
EP0187473B1 true EP0187473B1 (de) 1989-03-15

Family

ID=11210538

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85308779A Expired EP0187473B1 (de) 1984-12-03 1985-12-03 Verfahren zur Gerbung von Häuten

Country Status (6)

Country Link
EP (1) EP0187473B1 (de)
BR (1) BR8505963A (de)
DE (1) DE3568799D1 (de)
ES (1) ES8704548A1 (de)
IT (1) IT1178688B (de)
TR (1) TR23452A (de)

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4314975A (en) * 1979-11-11 1982-02-09 Motov David L Method for preparing titanium tanning agent
IT1163492B (it) * 1983-06-10 1987-04-08 Loris Guidi Procedimento per la concia delle pelli

Also Published As

Publication number Publication date
IT8423870A1 (it) 1986-06-03
IT8423870A0 (it) 1984-12-03
ES8704548A1 (es) 1987-04-01
ES549493A0 (es) 1987-04-01
IT1178688B (it) 1987-09-16
TR23452A (tr) 1989-12-29
BR8505963A (pt) 1986-08-19
DE3568799D1 (en) 1989-04-20
EP0187473A1 (de) 1986-07-16

Similar Documents

Publication Publication Date Title
EP2607500A1 (de) Lederherstellungsverfahren unter Verwendung eines löslichen, oxidierten, von Stärke abgeleiteten Polysaccharids und Zusammensetzungen damit
EP3469104B1 (de) Verfahren zur herstellung von leder
CA1232708A (en) Process for tanning hides
EP0187473B1 (de) Verfahren zur Gerbung von Häuten
US4875900A (en) Method of treating leather
US7033402B2 (en) Transposed process for making leather
JP3027480B2 (ja) クロム皮革を製造する方法
US3888625A (en) Method of chrome-retanning leather
KR920007576B1 (ko) 크롬을 사용하지 않은 가죽 무두질 방법
US7063728B2 (en) Process for making chrome tanned leathers
US3938951A (en) Method of obtaining titanium tanning agent and its application for tanning hides, pelts and fur skins
US2942930A (en) Alum tannage
US3960481A (en) Process for tanning leather
US3253879A (en) Chrome-syntan pretannage followed by dry chrome tannage
US4314803A (en) Tanning method
US3482925A (en) Process for the rapid tanning of leather
US4211529A (en) Chrome-tanning
US2707667A (en) Tanning limed skins
GB2057497A (en) Tanning Process
US1541819A (en) Method of and liquor for producing tanned leather
US3114589A (en) Rapid tanning sole leather using polyoxysaccharide bisulfites
JPS61133300A (ja) 皮なめし方法
US3521990A (en) Process for the rapid tanning of leather
US2019568A (en) Process of tanning
EP0064761B1 (de) Gerb- und Pickelverfahren und Pickelzusammnesetzungen

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB

17P Request for examination filed

Effective date: 19861120

17Q First examination report despatched

Effective date: 19870806

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REF Corresponds to:

Ref document number: 3568799

Country of ref document: DE

Date of ref document: 19890420

ET Fr: translation filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19891130

Year of fee payment: 5

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19891211

Year of fee payment: 5

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19900131

Year of fee payment: 5

26N No opposition filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19901203

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19910830

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19910903

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST