WO2002000941A1 - Use of gallic acid for stabilising chrome-iii against oxidation in chrome-tanned leather - Google Patents
Use of gallic acid for stabilising chrome-iii against oxidation in chrome-tanned leather Download PDFInfo
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- WO2002000941A1 WO2002000941A1 PCT/EP2001/006863 EP0106863W WO0200941A1 WO 2002000941 A1 WO2002000941 A1 WO 2002000941A1 EP 0106863 W EP0106863 W EP 0106863W WO 0200941 A1 WO0200941 A1 WO 0200941A1
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- chrome
- leather
- gallic acid
- chromium
- tanned leather
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Classifications
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- 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
- C14C3/06—Mineral tanning using chromium compounds
-
- 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
- the present invention relates to the use of gallic acid for stabilizing chromium III against undesired oxidation in chrome-tanned leather.
- tanning is understood to be a multi-stage process which serves to permanently preserve the unstable, perishable collagen of the animal skin freed from skin and hair, which is subjected to putrefaction and decomposition.
- the tannins used for tanning bring about a cross-linking of the skin's collagen molecules and thus the stabilization of the chain-like structures of the skin protein.
- Each tanning process runs in several phases, some of which are clearly separated from one another, but some of which merge.
- the preparation phase the skin substance is brought into the condition required for the process by soaking, pickling, liming, decalcifying, washing, pickling, pretanning or conditioning.
- the transport phase the tanning agent migrates to the binding sites by diffusion.
- the transport medium is always water, whereby additions of diffusion accelerating chemicals are possible.
- the binding phase usually begins before the transport phase is completed.
- Transport phase and binding phase can be understood in a certain way as "actual" tanning.
- chrome tanning is mainly carried out as so-called chrome tanning, in which salts of trivalent chromium (chromium III), for example chromium sulfate, are used.
- chrome tanning is still the most important tanning agent with a share of 80% and due to its technical advantages and versatility of chrome tanned leather, there is a unanimous opinion among experts that nothing will change in the foreseeable future of the dominant role of chrome tanning.
- Chromium-VI is toxic and therefore an undesirable pollutant
- experts pay special attention to methods for stabilizing Chromium-III against undesired oxidation.
- the object of the present invention was to provide a method for stabilizing chromium-III in chrome-tanned leather. Another object has been to provide substances or compositions which are introduced into the leather during the course of the leather production and which act as stabilizing additives for chromium III.
- gallic acid does an excellent job. It effectively stabilizes Chromium III without negatively affecting the application properties of the leather.
- the present invention firstly relates to the use of gallic acid for stabilizing chromium III against undesired oxidation in chrome-tanned leather.
- Gallic acid has the following chemical structure:
- the gallic acid can be used anywhere in the course of leather production. However, it is preferred to introduce gallic acid into chrome-tanned leather in the course of retanning.
- the amount of gallic acid depends essentially on the amount of chromium present in the leather.
- Gallic acid is preferably used in an amount which is 40 to 50% by weight - total amount of gallic acid based on the trivalent chromium introduced into the leather during tanning, this chromium being calculated as Cr 2 O 3 .
- gallic acid is used in combination with reducing agents.
- Reducing agents are substances that are able to reduce hexavalent chromium to trivalent chromium.
- suitable reducing agents are Na 2 S 2 0 5 , Na 2 S 2 0 3 , layered silicates, Na 2 S0 3 and iron (II) salts.
- the gallic acid is used in combination with radical scavengers.
- Free radical scavengers are substances that are able to bind free radicals. Examples of suitable radical scavengers are vitamin C, vitamin amine E, sterically hindered phenols and the HALS compounds known to the person skilled in the art ("hindered amine light stabilizer).
- Another object of the invention is a method for treating leather, whereby wet blue is treated with gallic acid at any point in the course of further processing to the finished leather - preferably in the course of retanning.
- wet blue familiar to the person skilled in the art is used in the context of the invention for chrome-tanned hides, irrespective of whether one processes these hides directly into ready-to-use leather after their manufacture or whether one obtains commercially available chrome-tanned hides, ie wet blue in the narrower sense processed into ready-to-use leather at a later date.
- the leather thus produced was tested for softness and fullness. The result can be seen in Table 1.
- the leather was aged for 24 hours at 80 ° C and then examined for its chromium VI content.
- the result can also be found in Table 1.
- Example 1 was repeated, but the addition of the gallic acid according to Example 1 was omitted (blank sample). The result can be seen in Table 1.
- Example 1 was repeated, with the following vegetable ones instead of gallic acid
- Tanning agents were used:
- Example 1 according to the invention is - in part very clearly - superior to the comparative examples with regard to the content of chromium VI. Another positive effect is that, with respect to the fullness and softness of the leather, Example 1 according to the invention deviates only insignificantly from Comparison 1, the blank sample.
- the use of vegetable tanning agents (comparisons 2 to 6), on the other hand, shows poorer quality results with the fullness and softness of the leather.
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- 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)
- Fats And Perfumes (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to the use of gallic acid which is suitable for stabilising chrome-III against oxidation in chrome-tanned leather.
Description
"Verwendung von Gallussäure zur Stabilisierung von Chrom-III gegen Oxidation in chromgegerbtem Leder" "Use of Gallic Acid to Stabilize Chromium III Against Oxidation in Chrome Tanned Leather"
Gebiet der ErfindungField of the Invention
Die vorliegende Erfindung betrifft die Verwendung von Gallussäure zur Stabilisierung von Chrom-III gegen unerwünschte Oxidation in chromgegerbtem Leder.The present invention relates to the use of gallic acid for stabilizing chromium III against undesired oxidation in chrome-tanned leather.
Stand der TechnikState of the art
Bekanntlich versteht man unter Gerbung einen mehrere Stufen umfassenden Prozeß, der dazu dient, das instabile, leicht verderbliche, der Fäulnis und Zersetzung unterworfene Kollagen der von Haut und Haaren befreiten tierischen Haut dauerhaft zu konservieren.As is known, tanning is understood to be a multi-stage process which serves to permanently preserve the unstable, perishable collagen of the animal skin freed from skin and hair, which is subjected to putrefaction and decomposition.
Die zur Gerbung verwendeten Gerbstoffe bewirken dabei eine Vernetzung der Kollagenmoleküle der Haut und damit die Stabilisierung der kettenförmigen Strukturen des Hauteiweißes.The tannins used for tanning bring about a cross-linking of the skin's collagen molecules and thus the stabilization of the chain-like structures of the skin protein.
Jede Gerbung verläuft in mehrere Phasen, die zum Teil deutlich voneinander getrennt sind, zum Teil aber auch ineinander übergehen. In der Vorbereitungsphase wird die Hautsubstanz durch Weichen, Beizen, Äschern, Entkalken, Waschen, Pickeln, Vorgerben oder Konditionieren in den für den Prozeß erforderlichen Zustand gebracht. In der Transportphase wandert der Gerbstoff durch Diffusion zu den Bindungsstellen. Dabei ist das Transportmedium stets Wasser, wobei Zusätze von diffusionsbeschleunigenden Chemikalien möglich sind. Die Bindungsphase beginnt meist schon, bevor die Transportphase abgeschlossen ist. Transportphase und Bindungsphase können in gewissen Weise als "eigentliche" Gerbung verstanden werden. Üblicherweise erfolgt nach dem
Einbringen der gerbenden Stoffe auch eine Nachbereitungsphase, die durch Vorgänge wie mechanische Bearbeitung, Neutralisieren, Nachgerbung, ggf. Färben, Fettung, Fixieren und Waschen gekennzeichnet ist.Each tanning process runs in several phases, some of which are clearly separated from one another, but some of which merge. In the preparation phase, the skin substance is brought into the condition required for the process by soaking, pickling, liming, decalcifying, washing, pickling, pretanning or conditioning. In the transport phase, the tanning agent migrates to the binding sites by diffusion. The transport medium is always water, whereby additions of diffusion accelerating chemicals are possible. The binding phase usually begins before the transport phase is completed. Transport phase and binding phase can be understood in a certain way as "actual" tanning. Usually takes place after Introducing the tanning substances also a post-processing phase, which is characterized by processes such as mechanical processing, neutralizing, retanning, possibly dyeing, greasing, fixing and washing.
Die Gerbung wird überwiegend als sogenannte Chromgerbung durchgeführt, bei der Salze des dreiwertigen Chroms (Chrom-III), zum Beispiel Chromsulfat, zum Einsatz kommen. Nach wie vor ist die Chromgerbung mit einem Anteil von übr 80% die wichtigste Gerbart und auf Grund ihrer technischen Vorteile und vielseitigen Verwendbarkeit chromgegerbten Leders herrscht in der Fachwelt einhellig die Auffassung, daß sich in absehbarer Zukunft an der dominierenden Rolle der Chromgerbung nichts ändern wird.The tanning is mainly carried out as so-called chrome tanning, in which salts of trivalent chromium (chromium III), for example chromium sulfate, are used. Chrome tanning is still the most important tanning agent with a share of 80% and due to its technical advantages and versatility of chrome tanned leather, there is a unanimous opinion among experts that nothing will change in the foreseeable future of the dominant role of chrome tanning.
In der Fachwelt entstand in jüngerer Vergangenheit eine Diskussion um eine mögliche Bildung von sechswertigem Chrom (Chrom- VI) in Leder. Anlaß dieser Diskussion waren Publikationen, in denen auf eine Bildung von Chrom- VI bei Einwirkung energiereicher Strahlung oder Wärme hingewiesen wurde:There has been a discussion among experts in the recent past about the possible formation of hexavalent chromium (chromium VI) in leather. This discussion was prompted by publications in which chromium VI was formed when exposed to high-energy radiation or heat:
• C.Hauber, H.P.Germann, "Untersuchungen zur Entstehung und Vermeidung von• C.Hauber, H.P. Germann, "Studies on the emergence and avoidance of
Chromat in Leder", Leder und Häutemarkt 1999, Seite 25-30Chromate in leather ", Leder und Häutemarkt 1999, pages 25-30
• Schill & Seilacher, "Trivalent chromium to hexavalent chromium?", Leather 1999• Schill & Seilacher, "Trivalent chromium to hexavalent chromium?", Leather 1999
(Heft 12), Seite 33-34(Issue 12), pages 33-34
• D.Graf, Dr. Boehme, "The influence of relative humidity of air during storage on the formation lowering of CR(VI) in chrome tanned leathers", World Leather 2000 (Mai), Seite 38-40)• D.Graf, Dr. Boehme, "The influence of relative humidity of air during storage on the formation lowering of CR (VI) in chrome tanned leathers", World Leather 2000 (May), pages 38-40)
Da Chrom- VI toxisch und damit ein unerwünschter Schadstoff ist, widmet die Fachwelt Methoden zur Stabilisierung von Chrom-III gegen unerwünschte Oxidation große Aufmerksamkeit. Es besteht daher ein großes Bedürfnis, Verfahren bereitzustellen, durch die eine solche Stabilisierung gewährleistet ist bzw. Substanzen oder Zusam-
mensetzungen bereitzustellen, die im Zuge der Lederherstellung in das Leder eingebracht werden und als stabilisierende Additive für Chrom-III wirken.Since Chromium-VI is toxic and therefore an undesirable pollutant, experts pay special attention to methods for stabilizing Chromium-III against undesired oxidation. There is therefore a great need to provide processes by means of which such stabilization is ensured or substances or compounds to provide solutions that are incorporated into the leather during the course of leather production and act as stabilizing additives for Chromium III.
Beschreibung der ErfindungDescription of the invention
Die Aufgabe der vorliegenden Erfindung hat darin bestanden, ein Verfahren zur Stabilisierung von Chrom-III in chromgegerbtem Leder bereitzustellen. Eine weitere Aufgabe hat darin bestanden, Substanzen oder Zusammensetzungen bereitzustellen, die im Zuge der Lederherstellung in das Leder eingebracht werden und als stabilisierende Additive für Chrom-III wirken.The object of the present invention was to provide a method for stabilizing chromium-III in chrome-tanned leather. Another object has been to provide substances or compositions which are introduced into the leather during the course of the leather production and which act as stabilizing additives for chromium III.
Es wurde gefunden, dass Gallussäure, die genannte Aufgabe ausgezeichnet löst. Sie bewirkt eine effektive Stabilisierung von Chrom-III, ohne sich negativ auf die Anwendungseigenschaften des Leders auszuwirken.It has been found that gallic acid does an excellent job. It effectively stabilizes Chromium III without negatively affecting the application properties of the leather.
Es soll in diesem Zusammenhang betont werden, daß auch dieser letztgenannte Punkt für den Fachmann überraschend ist, da der Fachmann davon ausgeht, daß jedes Einbringen von Substanzen in das Ledergefüge dessen Eingenschaften - zum Teil sehr nachhaltig - ändert. Nach Untersuchungen der Anmelderin haben beispielsweise vege- tabile Gerbstoffe einen gewissen Effekt im Hinblick auf eine Stabilisierung von Chrom-III, jedoch haben die mit vegetabilen Gerbstoffen nachbehandelten Leder signifikant schlechtere anwendungstechnische Eigenschaften: die so behandelten Leder weisen nämlich - im Vergleich zu Gallussäure - neben der geringeren Wirksamkeit der Chrom-III-Stabilisierung eine geringere Fülle und eine schlechtere Färbbarkeit auf.In this connection it should be emphasized that this last point is also surprising for the person skilled in the art, since the person skilled in the art assumes that every introduction of substances into the leather structure changes its properties - in some cases very sustainably. According to investigations by the applicant, for example, vegetable tannins have a certain effect with regard to stabilizing chromium III, but the leather aftertreated with vegetable tanning agents have significantly poorer application properties: the leather treated in this way has - in comparison to gallic acid - in addition to less effectiveness of the chromium III stabilization, a lower fullness and poorer dyeability.
Gegenstand der vorliegenden Erfindung ist zunächst die Verwendung von Gallussäure zur Stabilisierung von Chrom-III gegen unerwünschte Oxidation in chromgegerbtem Leder.
Gallussäure kommt die folgende chemische Struktur zu:The present invention firstly relates to the use of gallic acid for stabilizing chromium III against undesired oxidation in chrome-tanned leather. Gallic acid has the following chemical structure:
Sie kann im Rahmen der vorliegenden Erfindung als solche oder in Form ihrer Salze eingesetzt werden.In the context of the present invention, it can be used as such or in the form of its salts.
Die Gallussäure kann erfindungsgemäß an beliebiger Stelle im Zuge der Lederherstellung eingesetzt werden. Es ist jedoch bevorzugt, Gallussäure im Zuge der Nachger- bung in chromgegerbtes Leder einzubringen.According to the invention, the gallic acid can be used anywhere in the course of leather production. However, it is preferred to introduce gallic acid into chrome-tanned leather in the course of retanning.
Die Menge der Gallussäure richtet sich im wesentlichen nach der Menge des im Leder vorhandenen Chroms. Vorzugsweise setzt man Gallussäure in einer Menge ein, die 40 bis 50 Gew.% - Gesamtmenge von Gallussäure bezogen auf das bei der Gerbung ins Leder eingebrachte dreiwertige Chrom, wobei dieses Chrom als Cr203 berechnet wird - beträgt.The amount of gallic acid depends essentially on the amount of chromium present in the leather. Gallic acid is preferably used in an amount which is 40 to 50% by weight - total amount of gallic acid based on the trivalent chromium introduced into the leather during tanning, this chromium being calculated as Cr 2 O 3 .
In einer weiteren Ausführungsform setzt man Gallussäure in Kombination mit Reduktionsmitteln ein. Unter Reduktionsmitteln sind Stoffe zu verstehen, die in der Lage sind, hexavalentes Chrom zu trivalentem Chrom zu reduzieren. Beispiele für geeignete Reduktionsmittel sind Na2S205, Na2S203, Schichtsilikate, Na2S03 sowie Eisen-II- Salze.In a further embodiment, gallic acid is used in combination with reducing agents. Reducing agents are substances that are able to reduce hexavalent chromium to trivalent chromium. Examples of suitable reducing agents are Na 2 S 2 0 5 , Na 2 S 2 0 3 , layered silicates, Na 2 S0 3 and iron (II) salts.
In einer weiteren Ausführungsform setzt man die Gallussäure in Kombination mit Radikalfängern ein. Unter Radikalfängern sind Stoffe zu verstehen, die in der Lage sind, freie Radikale zu binden. Beispiele für geeignete Radikalfänger sind Vitamin C, Vit-
amin E, sterisch gehinderte Phenole sowie die dem Fachmann bekannten HALS- Verbindungen ("hindered amine light stabilizer).In a further embodiment, the gallic acid is used in combination with radical scavengers. Free radical scavengers are substances that are able to bind free radicals. Examples of suitable radical scavengers are vitamin C, vitamin amine E, sterically hindered phenols and the HALS compounds known to the person skilled in the art ("hindered amine light stabilizer).
Ein weiterer Erfindungsgegenstand ist ein Verfahren zur Behandlung von Leder, wobei man wet blue an einer beliebigen Stelle im Zuge der weiteren Bearbeitung zum fertigen Leder - vorzugsweise im Zuge der Nachgerbung - mit Gallussäure behandelt. Der dem Fachmann geläufige Ausdruck "wet blue" wird im Rahmen der Erfindung für chromgegerbte Häute verwendet, unabhängig davon, ob man diese Häute nach ihrer Herstellung direkt zum gebrauchsfertigen Leder weiterverarbeitet oder ob man kommerziell erhältliche chromgegerbte Häute, also wet blue im engeren Sinne, zu einem späteren Zeitpunkt zum gebrauchsfertigen Leder weiterverarbeitet.Another object of the invention is a method for treating leather, whereby wet blue is treated with gallic acid at any point in the course of further processing to the finished leather - preferably in the course of retanning. The term "wet blue" familiar to the person skilled in the art is used in the context of the invention for chrome-tanned hides, irrespective of whether one processes these hides directly into ready-to-use leather after their manufacture or whether one obtains commercially available chrome-tanned hides, ie wet blue in the narrower sense processed into ready-to-use leather at a later date.
Im Hinblick auf eine mögliche Mitverwendung von Reduktionsmitteln oder Radikalfängern gilt das bereits oben Gesagte.
With regard to the possible use of reducing agents or radical scavengers, what has already been said above applies.
B e i s p i e l eB e i s p i e l e
Beispiel 1 (Bl)Example 1 (Bl)
1000 g Wet blue (Herkunft: Türkisches Rind, gegerbt mit 8% Chromgerbstoff) wurde mit 20 g Gallussäure nachgegerbt und anschließend mit einem Fischölsulfitat gefettet.1000 g wet blue (origin: Turkish beef, tanned with 8% chrome tanning agent) was retanned with 20 g gallic acid and then greased with a fish oil sulfate.
Das so hergestellte Leder wurde hinsichtlich Weichheit und Fülle geprüft. Das Ergebnis kann Tabelle 1 entnommen werden.The leather thus produced was tested for softness and fullness. The result can be seen in Table 1.
Des weiteren wurde das Leder 24 Stunden bei 80 °C gealtert und anschließend auf seinen Gehalt an Chrom- VI untersucht. Das Ergebnis kann ebenfalls Tabelle 1 entnommen werden.Furthermore, the leather was aged for 24 hours at 80 ° C and then examined for its chromium VI content. The result can also be found in Table 1.
Vergleichsbeispiel 1 (VI)Comparative Example 1 (VI)
Beispiel 1 wurde wiederholt, wobei jedoch auf die Zugabe der Gaallussäure nach Beispiel 1 verzichtet wurde (Blindprobe). Das Ergebnis kann Tabelle 1 entnommen werden.Example 1 was repeated, but the addition of the gallic acid according to Example 1 was omitted (blank sample). The result can be seen in Table 1.
Vergleichsbeispiele 2 bis 6 (V2 bis V6)Comparative Examples 2 to 6 (V2 to V6)
Beispiel 1 wurde wiederholt, wobei anstelle der Gallussäure folgende vegetabilenExample 1 was repeated, with the following vegetable ones instead of gallic acid
Gerbstoffe eingesetzt wurden:Tanning agents were used:
V2) QuebrachoV2) Quebracho
V3) TaraV3) Tara
V4) KastanieV4) chestnut
V5) ValoneaV5) Valonea
V6) MimosaV6) Mimosa
Die Ergebnisse können Tabelle 1 entnommen werden.
Tabelle 1The results can be found in Table 1. Table 1
O ppm Chrom- VI im gealterten Leder (bestimmt gemäß DIN 53314)O ppm chromium VI in aged leather (determined according to DIN 53314)
Aus Tabelle 1 geht hervor, daß das erfindungsgemäße Beispiel 1 im Hinblick auf den Gehalt an Chrom- VI den Vergleichsbeispielen - zum Teil sehr deutlich - überlegen ist. Als weitere positive Wirkung fällt auf, daß hinsichtlich Fülle und Weichheit des Leders das erfindungsgemäße Beispiel 1 nur unwesentlich von Vergleich 1, der Blindprobe, abweicht. Der Einsatz von vegetabilen Gerbstoffen (Vergleiche 2 bis 6) zeigt dagegen qualitativ schlechtere Ergebnisse bei Fülle und Weichheit des Leders.
From Table 1 it can be seen that Example 1 according to the invention is - in part very clearly - superior to the comparative examples with regard to the content of chromium VI. Another positive effect is that, with respect to the fullness and softness of the leather, Example 1 according to the invention deviates only insignificantly from Comparison 1, the blank sample. The use of vegetable tanning agents (comparisons 2 to 6), on the other hand, shows poorer quality results with the fullness and softness of the leather.
Individueller StabilisierungstestIndividual stabilization test
Untersuchungen der Anmelderin haben gezeigt, daß die Wirkung von Additiven zur Stabilisierung von Chrom-III im Leder durch eine in-vitro-Untersuchung simuliert werden kann, bei der man jeweils 0,5 g der zu prüfenden Testsubstanz für 30 Minuten bei 20 °C auf eine wäßrige Lösung, die 25 ppm Chrom- Vl-Ionen enthält (hergestellt durch Lösen von Kaliumdichromat in Wasser), einwirken läßt und anschließend den Gehalt des Systems an Chrom- VI bestimmt. Die Ergebnisse dieses individuellen Stabilisierungstests können Tabelle 2 entnommen werden.Investigations by the applicant have shown that the effect of additives for stabilizing chromium III in leather can be simulated by an in vitro examination in which 0.5 g of the test substance to be tested is applied at 20 ° C. for 30 minutes an aqueous solution which contains 25 ppm chromium VI ions (prepared by dissolving potassium dichromate in water), and then determines the chromium VI content in the system. The results of this individual stabilization test can be found in Table 2.
Tabelle 2Table 2
Claims
1. Verwendung von Gallussäure zur Stabilisierung von Chrom-III gegen Oxidation in chromgegerbtem Leder.1. Use of gallic acid to stabilize chromium III against oxidation in chrome-tanned leather.
2. Verwendung nach Anspruch 1, wobei man die Gallussäure im Zuge der Nachgerbung in chromgegerbtes Leder einbringt.2. Use according to claim 1, wherein the gallic acid is introduced in the course of retanning in chrome-tanned leather.
3. Verwendung nach Anspruch 1 odaer 2, wobei man die Gallussäure in Kombination mit Reduktionsmitteln einsetzt.3. Use according to claim 1 or 2, wherein the gallic acid is used in combination with reducing agents.
4. Verwendung nach einem der Ansprüche 1 bis 3, wobei man die Gallussäure in Kombination mit Radikalfängern einsetzt.4. Use according to one of claims 1 to 3, wherein the gallic acid is used in combination with radical scavengers.
5. Verfahren zur Behandlung von Leder, dadurch gekennzeichnet, daß man wet blue an einer beliebigen Stelle im Zuge der weiteren Bearbeitung zum fertigen Leder mit Gallussäure behandelt.5. Process for the treatment of leather, characterized in that wet blue is treated at any point in the course of further processing to the finished leather with gallic acid.
6. Verfahren zur Behandlung von Leder, dadurch gekennzeichnet, daß man wet blue im Zuge der Nachgerbung Gallussäure behandelt. 6. Process for the treatment of leather, characterized in that gall blue acid is treated in the course of retanning.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE50103652T DE50103652D1 (en) | 2000-06-28 | 2001-06-19 | USE OF GALLIC ACID TO STABILIZE CHROME-III AGAINST OXIDATION IN CHROME TANED LEATHER |
| BR0111931-1A BR0111931A (en) | 2000-06-28 | 2001-06-19 | Use of gallic acid for the stabilization of chromium-iii against oxidation in chrome tanned leather |
| EP01964997A EP1297188B1 (en) | 2000-06-28 | 2001-06-19 | Use of gallic acid for stabilising chrome-iii against oxidation in chrome-tanned leather |
| AT01964997T ATE276376T1 (en) | 2000-06-28 | 2001-06-19 | USE OF GALLIC ACID FOR STABILIZING CHROME-III AGAINST OXIDATION IN CHROME TANNED LEATHER |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE10031548.8 | 2000-06-28 | ||
| DE10031548A DE10031548A1 (en) | 2000-06-28 | 2000-06-28 | Use of gallic acid to stabilize chromium III against oxidation in chrome-tanned leather |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2002000941A1 true WO2002000941A1 (en) | 2002-01-03 |
Family
ID=7647123
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2001/006863 WO2002000941A1 (en) | 2000-06-28 | 2001-06-19 | Use of gallic acid for stabilising chrome-iii against oxidation in chrome-tanned leather |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP1297188B1 (en) |
| AT (1) | ATE276376T1 (en) |
| BR (1) | BR0111931A (en) |
| DE (2) | DE10031548A1 (en) |
| WO (1) | WO2002000941A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016021461A1 (en) * | 2014-08-04 | 2016-02-11 | シチズンホールディングス株式会社 | Leather or leather article and method for producing same, hexavalent chromium treatment agent, method for treating hexavalent chromium in crude leather or crude leather article |
| EP3594304A4 (en) * | 2017-03-10 | 2021-03-17 | Citizen Watch Co., Ltd. | Powdery composition for hexavalent chromium treatment, tablet, and method for producing leather |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3935035A (en) * | 1973-06-05 | 1976-01-27 | Nippon Steel Corporation | Aqueous solution and method for surface treatment of metals |
| DE19860610A1 (en) * | 1998-12-29 | 2000-07-06 | Schill & Seilacher | Chrome-tanned leather for e.g. gloves, shoes, furniture or car seats is treated with dubbing containing antioxidant to reduce hexavalent chromium release potential |
-
2000
- 2000-06-28 DE DE10031548A patent/DE10031548A1/en not_active Withdrawn
-
2001
- 2001-06-19 DE DE50103652T patent/DE50103652D1/en not_active Expired - Lifetime
- 2001-06-19 EP EP01964997A patent/EP1297188B1/en not_active Expired - Lifetime
- 2001-06-19 WO PCT/EP2001/006863 patent/WO2002000941A1/en active IP Right Grant
- 2001-06-19 BR BR0111931-1A patent/BR0111931A/en not_active IP Right Cessation
- 2001-06-19 AT AT01964997T patent/ATE276376T1/en not_active IP Right Cessation
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3935035A (en) * | 1973-06-05 | 1976-01-27 | Nippon Steel Corporation | Aqueous solution and method for surface treatment of metals |
| DE19860610A1 (en) * | 1998-12-29 | 2000-07-06 | Schill & Seilacher | Chrome-tanned leather for e.g. gloves, shoes, furniture or car seats is treated with dubbing containing antioxidant to reduce hexavalent chromium release potential |
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| HAUBER C ET AL: "Untersuchungen zur Entstehung und Vermeidung von Chromat in Leder", LEDER UND HÄUTEMARKT, UMSCHAU ZEITSCHRIFTENVERLAG, FRANKFURT, DE, vol. 9, 1999, pages 25 - 30, XP001024706, ISSN: 0342-7641 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016021461A1 (en) * | 2014-08-04 | 2016-02-11 | シチズンホールディングス株式会社 | Leather or leather article and method for producing same, hexavalent chromium treatment agent, method for treating hexavalent chromium in crude leather or crude leather article |
| US10358686B2 (en) | 2014-08-04 | 2019-07-23 | Citizen Watch Co., Ltd. | Leather or leather article and method for producing same, hexavalent chromium treatment agent, method for treating hexavalent chromium in crude leather or crude leather article |
| EP3594304A4 (en) * | 2017-03-10 | 2021-03-17 | Citizen Watch Co., Ltd. | Powdery composition for hexavalent chromium treatment, tablet, and method for producing leather |
Also Published As
| Publication number | Publication date |
|---|---|
| EP1297188A1 (en) | 2003-04-02 |
| ATE276376T1 (en) | 2004-10-15 |
| DE50103652D1 (en) | 2004-10-21 |
| EP1297188B1 (en) | 2004-09-15 |
| DE10031548A1 (en) | 2002-01-10 |
| BR0111931A (en) | 2003-06-17 |
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