Auxiliary agents with non-swelling capacity used in pickling-tanning processes - Part 3 / Agusti Marsal in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 88, N° 5 (09-10/2004)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 88, N° 5 (09-10/2004) . - p. 191-196 Titre : Auxiliary agents with non-swelling capacity used in pickling-tanning processes - Part 3 Type de document : texte imprimé Auteurs : Agusti Marsal, Auteur ; Ramón Palop, Auteur ; V. Frias, Auteur ; Joaquim Font, Auteur ; J. Cot, Auteur ; Albert M. Manich, Auteur Année de publication : 2004 Article en page(s) : p. 191-196 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Agents anti-gonflement Bains de trempe -- Analyse Cuirs et peaux -- Epaisseur Eaux usées -- Analyse Epaisseur -- Mesure Naphtalène sulfonique, Acide L'acide naphtalènesulfonique est un composé aromatique de formule brute C10H8O3S, constitué d'un noyau naphtyle substitué par un groupe sulfo. Comme tous les dérivés monosubstitués du naphtalène, il existe sous la forme de deux isomères, selon que le substituant soit en position 1 ("α", ou péri) ou 2 ("β" ou amphi). Synthèse : Au plan commercial, l'acide naphtalènesulfonique est produit par sulfonation du naphtalène, effectuée par la méthode classique à base d'acide sulfurique. Les réacteurs modernes sont revêtus de verre ; les équipements plus anciens étaient en fonte ou recouverts d'émail. En général, la sulfonation du naphtalène conduit à un mélange de produits. La sulfonation du naphtalène à moins de ~100 °C est sous contrôle cinématique et produit principalement de l'acide 1-naphtalènesulfonique. La sulfonation du naphtalène à plus de ~150 °C permet un contrôle thermodynamique de la réaction et l'acide 2-naphtalènesulfonique est alors le produit principal. Dérivés : On appelle "acides naphtalènesulfoniques" les dérivés substitués de l'acide naphtalènesulfonique. Ce sont d'importants précurseur et intermédiaires chimiques, notamment dans la production de colorants, d'agents mouillants, de dispersants, de naphtols et d'entraîneurs d'air pour béton et ciment1. La production de nombreux intermédiaires pour former des colorants azoïques ou de triphénylméthane implique la sulfonation du naphtalène suivie d'une autre opération, par exemple la nitration, la réduction ou l'amination. Picklage Le picklage consiste à faire absorber à la peau en tripe une quantité importante d'acide, en présence de sel neutre (NaCl) pour réprimer le gonflement que provoquerait l'acidité du milieu. Tannage au chrome Température de retrait Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : In the last ten years, the use of various types of aromatic sulphonic acids in the pickling process to prevent swelling has been suggested by many authors. In previous papers, we studied the capacity of four commercial products to prevent acid swelling of hides during pickling: polyacrylic acid, naphthol 3-6-disulphonic acid, p-hydroxydiphenyl sulphonic acid and a blend of naphthalene and naphthol sulphonic acids. It was found that the best results were obtained using the blend of naphthalene and naphthol sulphonic acids. This process yielded leathers that could be acceptable as far as physical properties and handle are concerned. However ; this process, which also reduced the chloride content and conductivity of the residual bath when compared with a standard pickling process, presented some disadvantages such as an irregular stratigraphic distribution of chromium and a marked difference of colour between the dyed grain and flesh layers after shaving, when using a conventional chromium tanning salt. This was due to the thickness of the hides (3.0 mm) which caused problems of penetration of the chemicals. In order to solve these disadvantages, the joint use of a mixture of a blend of naphthalene and naphthol sulphonic acids with a chromium salt of low basicity and high masking capacity was recommended. Note de contenu : - INTRODUCTION : Aim of the work - EXPERIMENTAL PROCEDURE : Starting material - Non-swelling Products - Sodium chloride offer - RESULTS : Thickness after pickling - Thickness and shrinkage temperature after tannage - Analyses of the residual baths of pickling and tanning processes - Table 1 : Treatments with the studied products - Table 2 : Thickness variation (%) after pickling as a function of both salinity and type and offer of the auxiliary agents - Table 3 : Thickness variation (%) after tanning as a function of both salinity and type and offer of the auxiliary agents - Table 4 : Shrinkage temperature (°C) as a function of both salinity and type and offer of the auxiliary agents - Table 5 : Conductivity of the pickling bath (μS/cm) as a function of both salinity and type and offer of the auxiliary agents - Table 6 : Conductivity of the tanning bath (μS/cm) as a function of both salinity and type and offer of the auxiliary agents - Table 7 : Chemical Oxygen Demand (COD) of the pickling bath as a function of both salinity and type and offer of the auxiliary agents En ligne : https://drive.google.com/file/d/1-1SfLAzYNbmtFc5VZ6JlvEw9olv6rDCd/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39623 [article]

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Auxiliary agents with non-swelling capacity used in pickling-tanning processes - Part 4 / Agusti Marsal in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 88, N° 6 (11-12/2004)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 88, N° 6 (11-12/2004) Titre : Auxiliary agents with non-swelling capacity used in pickling-tanning processes - Part 4 Type de document : texte imprimé Auteurs : Agusti Marsal, Auteur ; Ramón Palop, Auteur ; V. Frias, Auteur ; M. D. de Castellar, Auteur ; Pedro J. Celma, Auteur ; Albert M. Manich, Auteur Année de publication : 2004 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Agents anti-gonflement Cuirs et peaux -- Analyse Cuirs et peaux -- Propriétés mécaniques Cuirs et peaux de moutons Picklage Le picklage consiste à faire absorber à la peau en tripe une quantité importante d'acide, en présence de sel neutre (NaCl) pour réprimer le gonflement que provoquerait l'acidité du milieu. Post-tannage Résistance à la déchirure Résistance à la traction Tannage au chrome Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The reduction in the use of salt in pickling due to the application of different chemicals with non-swelling capacity - polyacrylic acid, naphthol 3-6-disulphonic acid, p-hydroxydiphenyl sulphonic acid and a blend of naphthalene and naphthol sulphonic acids- has been studied in previous papers.1-3 These chemicals were applied in the pickling process either alone or with small amount of salt. In Part I1, it was confirmed that the blend of naphthalene and naphthol sulphonic acids at an offer of 3% (on pelt weight) and at a salinity of 2°Bé could be a valid alternative since it adequately prevented the swelling of hides. Tanning treatments with conventional chromium salts yielded the correct shrinkage temperatures. In Part II2 it was observed that the conventional tanning process of hides pickled with sulphuric acid and 3% (on pelt weight) of the blend of naphthalene and naphthol sulphonic acids at a salinity of 2°Bé yielded leathers that could be acceptable as far as physical properties and handle were concerned. However; these leathers showed an irregular stratigraphic distribution of Cr2O3 and a marked colour difference between grain and flesh sides. Optimization of the tanning process of these hides confirmed that the best results were obtained with a strongly masked chromium salt with a very low basicity. In Part III3, the possible application of chemicals with non-swelling capacity to reduce the use of salt in the pickling process of sheepskins was studied. In this case, the use of a strongly masked chromium salt with a very low basicity in the tanning process was not necessary since conventional tanning salts were adequate. The best results in terms of non-swelling capacity, shrinkage temperature of the tanned hides, conductivity and Chemical Oxygen Demand of the residual baths were achieved under the following conditions: 2% p-hydroxydiphenyl sulphonic acid (salinity 2°Bé); 2% naphthol 3-6-disulphonic acid (salinity 2°Bé) and 4% polyacrylic acid (salinity 2°Bé). Note de contenu : - AIM OF THE WORK - EXPERIMENTAL PROCEDURE : Pickle and tannage - Process evaluation - RESULTS : Swelling of the pickled/tanned skins - Evaluation of the pickling and tanning residual baths - Leather characteristics - APPENDIX : Chemicals utilized in this work - Table 1 : Comparative study between pickling processes - Table 2 : Post-tanning processes - Table 3 : Thickness variation (%) after pickling/tanning in relation to bating - Table 4 : Evaluation of the pickling and tanning residual baths - Table 5 : Leather characteristics as a function of the pickling process - Table 6 : Tensile strength (IUP 6) - Table 7 : Tear Resistance (IUP 8) - Table 8 : Measurement of distension and strength of the grain by the Ball Burst Test (IUP 9) En ligne : https://drive.google.com/file/d/1KGJNb1N6N3BJ-enzwHjtuzRzbeI92kqw/view?usp=shari [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39617 [article]

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