[article]
| Titre : |
Some thoughts on standardisation of synthetic tanning materials |
| Type de document : |
texte imprimé |
| Auteurs : |
Samir Das Gupta, Auteur |
| Année de publication : |
1980 |
| Article en page(s) : |
p. 16-23 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Cuirs et peaux
Syntans
Tannage synthétique
|
| Index. décimale : |
675.2 Préparation du cuir naturel. Tannage |
| Résumé : |
Syntans are in general condensation products of aromatic substances (cresol, phenol, naphthol and naphthalene), formaldehyde and sulphuric acid. There are, however, many variations in the ingredients, the relative quantities used and the technique of production. The chemistry of syntans is extensively discussed and evaluated by Otto, Kuntzel and Gustavson. In general, the bigger the molecules of the tan and the higher the proportion of secondary valencies it possesses relative to sulphonic groups, the fuller the leather it will produce. The secondary valencies are a function of the dipole moments and phenolic OH groups in the molecule and can lead to H-bonds on the protein structure. On the other hand the presence of highly ionised sulphonic groups in the mole-cule can inhibit this effect. By carefully manipulating these two main factors, the final leather-forming character of the syntan is obtained. In fact innumerable opportunities exist for the manufacture of syntan having varying product characteristics.
Resin tanning materials on the other hand are either condensation products of aminoplasts like urea, melamine–formaldehyde, dicyandiamide–formaldehyde, or copolymers of styrene–maleic anhydride or polyamide or polymerisation products of acrylic monomers. Mostly they are used as retanning agents. The point worth considering is whether such a big range, presently manufactured by each manufacturer, is absolutely required by a tanner. An attempt has therefore been made in this paper to analyse the reasons for such a wide range of syntans and to suggest an approach for standardisation of these synthetic tanning materials. |
| Note de contenu : |
- Why so many syntans ?
- Historical development of syntans
- Classifications and grouping of synthetic tanning materials
- Parameters for specification : Identification - Parameters
- Proposed specifications : Auxiliary syntans - General - Neutral levelling and dispersing syntans - Chrome syntans - Resin tanning materials - Aldehydes and miscellaneous products
- Table 1 : Requirements for auxiliary syntans
- Table 2 : Requirements for replacement syntans
- Table 3 : Requirements for levelling syntans
- Table 4 : Requirements for chrome syntans
- Table 5a : Requirements for resins, type 1
- Table 5b : Requirements for resins, type 2
- table 5c : Requirements for resisn, type 4
- Table 5d : Requirements for resins, type 3 |
| En ligne : |
https://drive.google.com/file/d/18aqlzuS9tJrnABGD_TwYd4BR4zd3Ew6k/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34133 |
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 64, N° 1 (01-02/1980) . - p. 16-23
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Some thoughts on standardisation of synthetic tanning materials in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 64, N° 1 (01-02/1980)
