[article]
| Titre : |
Oxazolidines - A new class of tanning agents |
| Type de document : |
texte imprimé |
| Auteurs : |
Samir Dasgupta, Auteur |
| Année de publication : |
1977 |
| Article en page(s) : |
p. 97-105 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Agents de tannage
Chaleur humide
Croûte (cuir)On entend par "cuir en croûte" des cuirs ayant subi les opérations jusqu'au tannage, à l'exclusion de toute opération de corroyage ou de finissage, mais qui, par opposition aux wet-blue ont été séchés.
Cuir -- Teneur en chrome trivalent
Cuirs et peaux -- Analyse
Cuirs et peaux de moutons
Oxazolidine
Résistance à la déchirure
Résistance à la traction
Tannage au chrome
Tannage combinéLe tannage combiné se dit des tannages qui allient deux familles ou genre de tannage pour obtenir un résultat additionnant les qualités complémentaires des tannins mis en œuvre par exemple Chrome-Végétal ou Chrome-Synthétique
Tannage végétal
Transpiration
|
| Index. décimale : |
675.2 Préparation du cuir naturel. Tannage |
| Résumé : |
Oxazolidines are heterocyclic derivatives obtained by the reaction of aminohydroxy compounds with aldehydes. The bifunctional behaviour of these oxazolidines is responsible for their cross-linking reactions with phenols and proteins. Two typical oxazolidines, namely 4,4-Dimethyl-1,3-oxazolidine and 1-Aza-3,7-dioxabicyclo-5-ethyl (3,3,0) Octane have been studied extensively for their use as tanning agents and it has been found that both these oxazolidines react with hide protein and impart special characteristics to leather when tanned in conjunction with syntan, chrome or vegetable tanning materials.
4,4-Dimethyl-1,3-oxazolidine has been found especially suitable for pretanning of greasy pickled sheepskins, subsequently to be degreased with aqueous degreasing systems. Pickled sheepskin even at 3-5 % level of application gives shrinkage temperatures around 70-75°C within an hour of treatment and unlike glutaraldehyde, the pretanned leather remains natural white and so may be finally tanned with syntan or zirconium for white leather.
1-Aza-3,7-dioxabicyclo-5-ethyl (3,3,0) Octane on the other hand has been found suitable for chrome or vegetable combination tannages of all kinds of leather, especially wool skin tannages where the wool remains spotless white even if the pH of the exhaust chrome liquor moves up to 4.5. Vegetable tanned leather pre-treated with 1-Aza-3,7-dioxabicyclo-5-ethyl (3,3,0) Octane gives higher degree of tannage, higher shrinkage temperature and about 50 % lower water solubles than conventional tannage. Normal vegetable tanned leather when retanned with about 10 % of 1-Aza-3,7-dioxa-bicyclo-5-ethyl (3,3,0) Octane for an hour gives a shrinkage temperature around 100°c. Fuither, it has been found that the use of oxazolidine affords better utilisation of chrome when used in chrome tanning. The reduced chrome content in the exhaust liquors helps in pollution control. |
| Note de contenu : |
- EXPERIMENTAL : Effect of initial pH and time - Effect of concentration - Tannage in combination with chrome - Tannage in combination with vegetable tanning materials - Comparison with glutaraldehyde-chrome combination tannages. Oxazoliding I vs. glutaraldehyde on pretannages of skins - Oxazolidine II vs. Glutaraldehyde on chrome tanning of sheepskins - Oxazolidine II vs. glutaraldehyde on vegetable tannage of sheepskins
- Table 1 : Typical properties of oxazolidines
- Table 2 : Chrome content of finished leather
- Table 3 : Tear strength of finished leather
- Table 4 : Tensile strength of finished leather
- Table 5 : Effect of moist heat on leather
- Table 6 : Effect of perspiration solution on leather
- Table 7 : Tensile strength of vegetable tanned crust leather
- Table 8 : Tear strength of vegetable tanned crust leather
- Table 9 : Chemical analysis of vegetable tanned crust leather
- Table 10 : Effect of moist heat on vegetable leather
- Table 11 : Effect of perspiration solution on vegetable tanned leather |
| En ligne : |
https://drive.google.com/file/d/1G6mpUYSZp3ekgWrtLRMORyPSpD2O_avE/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34125 |
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 61, N° 5 (09-10/1977) . - p. 97-105
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Oxazolidines - A new class of tanning agents in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 61, N° 5 (09-10/1977)
