EP0563139B1 - Method for processing hides or leather based on methanesulphonate ions. - Google Patents
Method for processing hides or leather based on methanesulphonate ions. Download PDFInfo
- Publication number
- EP0563139B1 EP0563139B1 EP92901323A EP92901323A EP0563139B1 EP 0563139 B1 EP0563139 B1 EP 0563139B1 EP 92901323 A EP92901323 A EP 92901323A EP 92901323 A EP92901323 A EP 92901323A EP 0563139 B1 EP0563139 B1 EP 0563139B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- hides
- leathers
- methanesulfonic acid
- tanning
- skins
- 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 - Lifetime
Links
- 238000000034 method Methods 0.000 title claims abstract description 33
- -1 methanesulphonate ions Chemical class 0.000 title claims description 19
- 239000010985 leather Substances 0.000 title abstract description 12
- AFVFQIVMOAPDHO-UHFFFAOYSA-N Methanesulfonic acid Chemical compound CS(O)(=O)=O AFVFQIVMOAPDHO-UHFFFAOYSA-N 0.000 claims abstract description 88
- 238000004519 manufacturing process Methods 0.000 claims abstract description 34
- 230000008569 process Effects 0.000 claims abstract description 26
- 238000005554 pickling Methods 0.000 claims abstract description 16
- 239000002253 acid Substances 0.000 claims abstract description 12
- 238000004043 dyeing Methods 0.000 claims abstract description 11
- 238000009826 distribution Methods 0.000 claims abstract description 5
- 239000000835 fiber Substances 0.000 claims abstract description 4
- 229940098779 methanesulfonic acid Drugs 0.000 claims description 40
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 18
- 239000000047 product Substances 0.000 claims description 16
- MURRHPKQJKICNT-UHFFFAOYSA-K chromium(3+) methanesulfonate Chemical compound [Cr+3].CS([O-])(=O)=O.CS([O-])(=O)=O.CS([O-])(=O)=O MURRHPKQJKICNT-UHFFFAOYSA-K 0.000 claims description 14
- 239000003925 fat Substances 0.000 claims description 14
- 239000003795 chemical substances by application Substances 0.000 claims description 13
- 239000002609 medium Substances 0.000 claims description 11
- 238000000265 homogenisation Methods 0.000 claims description 6
- LFWURQXIHGFGSF-UHFFFAOYSA-L barium(2+);methanesulfonate Chemical compound [Ba+2].CS([O-])(=O)=O.CS([O-])(=O)=O LFWURQXIHGFGSF-UHFFFAOYSA-L 0.000 claims description 5
- GRWVQDDAKZFPFI-UHFFFAOYSA-H chromium(III) sulfate Chemical compound [Cr+3].[Cr+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O GRWVQDDAKZFPFI-UHFFFAOYSA-H 0.000 claims description 5
- 230000000694 effects Effects 0.000 claims description 5
- 238000001914 filtration Methods 0.000 claims description 4
- 235000013311 vegetables Nutrition 0.000 claims description 4
- 239000012736 aqueous medium Substances 0.000 claims description 3
- 150000002500 ions Chemical class 0.000 claims description 3
- 239000003960 organic solvent Substances 0.000 claims description 3
- 239000002244 precipitate Substances 0.000 claims description 3
- 150000003839 salts Chemical class 0.000 claims description 3
- 159000000009 barium salts Chemical class 0.000 claims description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 2
- 239000011707 mineral Substances 0.000 claims description 2
- 239000000203 mixture Substances 0.000 claims description 2
- 230000007935 neutral effect Effects 0.000 claims description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 15
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 15
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 12
- 206010013786 Dry skin Diseases 0.000 description 11
- 239000011651 chromium Substances 0.000 description 11
- 230000037336 dry skin Effects 0.000 description 11
- 239000000243 solution Substances 0.000 description 9
- 239000000126 substance Substances 0.000 description 9
- 238000011282 treatment Methods 0.000 description 9
- 229910052804 chromium Inorganic materials 0.000 description 8
- 235000013305 food Nutrition 0.000 description 8
- 230000006872 improvement Effects 0.000 description 8
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 6
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 6
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 6
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 6
- 235000019253 formic acid Nutrition 0.000 description 6
- 239000011780 sodium chloride Substances 0.000 description 6
- 238000003756 stirring Methods 0.000 description 6
- 239000004094 surface-active agent Substances 0.000 description 6
- 241000283903 Ovis aries Species 0.000 description 5
- 238000013019 agitation Methods 0.000 description 5
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 5
- 239000012267 brine Substances 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 5
- AFVFQIVMOAPDHO-UHFFFAOYSA-M methanesulfonate group Chemical class CS(=O)(=O)[O-] AFVFQIVMOAPDHO-UHFFFAOYSA-M 0.000 description 5
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 5
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 4
- 239000000975 dye Substances 0.000 description 4
- 239000000839 emulsion Substances 0.000 description 4
- 150000003871 sulfonates Chemical class 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 239000004280 Sodium formate Substances 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 238000005119 centrifugation Methods 0.000 description 3
- 239000004744 fabric Substances 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 235000017557 sodium bicarbonate Nutrition 0.000 description 3
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 3
- HLBBKKJFGFRGMU-UHFFFAOYSA-M sodium formate Chemical compound [Na+].[O-]C=O HLBBKKJFGFRGMU-UHFFFAOYSA-M 0.000 description 3
- 235000019254 sodium formate Nutrition 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 230000000007 visual effect Effects 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 102000008186 Collagen Human genes 0.000 description 2
- 108010035532 Collagen Proteins 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 241000209504 Poaceae Species 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 125000002091 cationic group Chemical group 0.000 description 2
- 229920001436 collagen Polymers 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 230000001804 emulsifying effect Effects 0.000 description 2
- 150000007524 organic acids Chemical class 0.000 description 2
- 235000006408 oxalic acid Nutrition 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- RILZRCJGXSFXNE-UHFFFAOYSA-N 2-[4-(trifluoromethoxy)phenyl]ethanol Chemical compound OCCC1=CC=C(OC(F)(F)F)C=C1 RILZRCJGXSFXNE-UHFFFAOYSA-N 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- 229910000861 Mg alloy Inorganic materials 0.000 description 1
- 235000017343 Quebracho blanco Nutrition 0.000 description 1
- 229910006069 SO3H Inorganic materials 0.000 description 1
- 241000065615 Schinopsis balansae Species 0.000 description 1
- 240000008042 Zea mays Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000000980 acid dye Substances 0.000 description 1
- 239000002671 adjuvant Substances 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 230000029936 alkylation Effects 0.000 description 1
- 238000005804 alkylation reaction Methods 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 230000001580 bacterial effect Effects 0.000 description 1
- RQPZNWPYLFFXCP-UHFFFAOYSA-L barium dihydroxide Chemical compound [OH-].[OH-].[Ba+2] RQPZNWPYLFFXCP-UHFFFAOYSA-L 0.000 description 1
- 229910001863 barium hydroxide Inorganic materials 0.000 description 1
- 238000004061 bleaching Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 150000001844 chromium Chemical class 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- HQWKKEIVHQXCPI-UHFFFAOYSA-L disodium;phthalate Chemical compound [Na+].[Na+].[O-]C(=O)C1=CC=CC=C1C([O-])=O HQWKKEIVHQXCPI-UHFFFAOYSA-L 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- 230000032050 esterification Effects 0.000 description 1
- 238000005886 esterification reaction Methods 0.000 description 1
- 235000019441 ethanol Nutrition 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000010534 mechanism of action Effects 0.000 description 1
- 229910001510 metal chloride Inorganic materials 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000002480 mineral oil Substances 0.000 description 1
- 230000020477 pH reduction Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000035807 sensation Effects 0.000 description 1
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 description 1
- 235000019345 sodium thiosulphate Nutrition 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- BDHFUVZGWQCTTF-UHFFFAOYSA-M sulfonate Chemical compound [O-]S(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-M 0.000 description 1
- 235000018553 tannin Nutrition 0.000 description 1
- 229920001864 tannin Polymers 0.000 description 1
- 239000001648 tannin Substances 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
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
-
- 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
- C14C1/00—Chemical treatment prior to tanning
- C14C1/08—Deliming; Bating; Pickling; Degreasing
-
- 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
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06P—DYEING OR PRINTING TEXTILES; DYEING LEATHER, FURS OR SOLID MACROMOLECULAR SUBSTANCES IN ANY FORM
- D06P1/00—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed
- D06P1/44—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed using insoluble pigments or auxiliary substances, e.g. binders
- D06P1/62—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed using insoluble pigments or auxiliary substances, e.g. binders using compositions containing low-molecular-weight organic compounds with sulfate, sulfonate, sulfenic or sulfinic groups
- D06P1/621—Compounds without nitrogen
- D06P1/622—Sulfonic acids or their salts
- D06P1/623—Aliphatic, aralophatic or cycloaliphatic
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06P—DYEING OR PRINTING TEXTILES; DYEING LEATHER, FURS OR SOLID MACROMOLECULAR SUBSTANCES IN ANY FORM
- D06P3/00—Special processes of dyeing or printing textiles, or dyeing leather, furs, or solid macromolecular substances in any form, classified according to the material treated
- D06P3/02—Material containing basic nitrogen
- D06P3/04—Material containing basic nitrogen containing amide groups
- D06P3/32—Material containing basic nitrogen containing amide groups leather skins
Definitions
- the invention relates to a method of treating tanneries or tannery made from collagenous fabrics such as skins or leathers, with a view to achieving a loosening effect on the fibers of the fabrics and internal distribution of fats, leading to an increase in surface area. skins and a homogenization of their thickness, and also an improvement in the surface qualities of the articles (feel, appearance, regularity, ...) and their flexibility.
- the existing treatment agents which lead to a certain improvement in the leathers are generally specific to such or such operation (for example acetic acid and adjuvant for the pickling of skins, cationic / anionic products or surfactants for the food of leathers ...) and cannot be used at any other stage of production.
- One of the essential defects of the skins resides in the thickness irregularities which they present: currently, no treatment process is capable of making it possible to obtain a uniform thickness of the skins and to increase the surface thereof, while preserving their integrity. It is important to emphasize that most skins are sold on the surface and that a significant gain in surface area, associated with a more uniform thickness represents a considerable industrial advantage.
- the present invention proposes to provide a new process for the treatment of skins or hides made up of collagenous tissues with a view to homogenizing their thickness and increasing their surface area while preserving their integrity.
- An objective of the invention is to obtain this result without adding an external product to the collagen structure, in particular without adding fat.
- Another objective is to concomitantly improve the surface qualities of the skins (feel, appearance) and their flexibility, and this, in a more pronounced manner than the known methods.
- Another objective is to provide a cost process compatible with the valuation of lower quality skins under good profitability conditions.
- Another objective is to provide a process capable of being implemented at different stages of the manufacture of leather (in particular at the stages which involve a lowering of the pH).
- the process according to the invention for treating tanneries and tanning articles made up of collagenous fabrics such as skins and leather consists in bringing the skins or leathers in contact with methanesulfonic acid CH3 SO3H or methanesulfonate ions CH3 SO3 ⁇ In an acid medium.
- the skins can in particular be brought into contact with methanesulfonic acid in an aqueous medium or a mixed water / organic solvent medium.
- the term "mixed medium” will mean a medium containing one or more organic solvents and water, even if the latter remains in very small proportion).
- the minimum quantity of methanesulfonic acid or of methanesulfonate ions in acid medium necessary to lead to a sensitive result is of the order of 0.05 mol per kg of dry skins or hides. (By a weight of "dry skins”, we mean the weight of the skins at the start of the treatment, minus the weight of bound water).
- the invention was born from the chance observation of an unexpected and remarkable phenomenon: when skins or leathers are brought into contact with methanesulfonic acid or methanesulfonate ions in an acid medium, whatever the stage of manufacture where this contacting is practiced, there is an effect of loosening of the fibers of the collagen tissues and internal distribution of clean fats: the thickness of the skins is made more uniform, while the surface of these is significantly increased (by about 5%). Methanesulfonic acid or methanesulfonate ions are found almost entirely at the end of treatment in the bath, so that no contribution has been made in the skin.
- the mechanism of action is difficult to explain at present: it seems that the methanesulfonate ions temporarily bind to the clean fats of the skin to increase mobility and allow migration of fats from the thickest parts of the skin. (therefore the fatty ones) to produce a spreading effect, leading to an increase in the surface and a homogenization of the thickness; this fixation is then destroyed for reasons that are not well known and the methanesulfonate returns to the bath where it is recovered.
- the total amount of methanesulfonic acid or methanesulfonate ions is preferably between 0.1 and 2 moles per kg of dry skin: this amount therefore remains very small compared to the amount of clean fat of the skin, so that the actions above mentioned are catalytic type.
- methanesulfonic acid or methanesulfonate ions contain a single carbon and are not surfactants: they have properties completely different from those of the long chain sulfonates used to nourish skins thanks to the fats that they bring to these.
- the effects on the skin of the process of the invention are very different from those of a food operation since, in the case of the invention, the compound is almost completely recovered and is not definitively fixed in or on the skin: it acts on its own fats and preserves the integrity of the skins without external material supply in their texture, which is not the case with the above-mentioned surfactants.
- Methanesulfonate ions are closer, by their chemical structure and known properties, to sulfate ions; the latter have been used for a long time in tanning operations for hides and skins without leading to the results provided by the ions of the process targeted by the invention (namely: action on the clean fats of the skin leading to homogenization of thickness and increase in surface).
- the methanesulfonic acid which leads in an aqueous medium to methanesulfonate ions is a strong organic acid, well known in itself.
- US Patent 2,297,722 describes a manufacturing process. It is currently used essentially as a substitute for fluoroboric acid in electroplating baths, as a trapping agent for heavy metals in petroleum derivatives, as a corrosion inhibitor against magnesium alloys, or as a catalyst for certain reactions ( esterification, alkylation, polymerization of olefins ).
- the tests also made it possible to note that the process of the invention made it possible to obtain a reproducible, very significant improvement in the surface condition of the skins and their suppleness.
- all the metallic methanesulfonates being very soluble in water, the process of the invention avoids any risk of precipitation of insoluble salts (calcium sulfate for example) capable of being deposited on or in the skins during the cycle of manufacturing and cause a degradation of their surface qualities or flexibility.
- the leather manufacturing cycle from raw hides generally includes a pickling operation consisting in acidifying these hides. Bringing raw or tripe skins into contact with methanesulfonate ions can be carried out during this pickling operation using methanesulfonic acid optionally combined with another acid (in particular sulfuric acid).
- the manufacturing cycle also includes a tanning operation.
- the contacting can be carried out during this operation by introducing the methanesulfonate ions into the tanning bath.
- the tanning agent for this bath can be of any known type, mineral, vegetable and / or synthetic and the bath then contains a mixture of this agent and methanesulfonic acid or a salt of this acid.
- chromium tanning with a specific agent consisting of chromium methanesulfonate in an aqueous or mixed medium. This compound releases both the metal ions ensuring the tanning and the methanesulfonate ions leading to the abovementioned results.
- the leather manufacturing cycle also includes a dyeing operation, bringing the dye into contact is generally ensured at a pH close to neutral and fixing it at a lower pH.
- the methanesulfonate ions can be brought into contact during this operation by using methanesulfonic acid optionally combined with another organic acid (in particular formic acid or acetic acid).
- the skins can be brought into contact with the methanesulfonate ions several times and in particular at the three aforementioned manufacturing stages: pickling, tanning and dyeing.
- This mode of implementation leads in particular to the following practical advantage: to obtain a given quality, the concentration of methanesulfonate ions is lower at each operation (compared to a single contacting), which avoids too great a reduction pH, which could be detrimental to the quality of the skins.
- the total optimal quantity of methanesulfonate ions which should be brought into contact with the skins in one or more stages during the manufacturing cycle to obtain a marked improvement in their qualities without wasting product , seems to be understood, as already indicated, between 0.1 and 2.0 moles per kg of dry skins or hides.
- This process consists in reacting methanesulfonic acid on a barium salt, then reacting the barium methanesulfonate obtained with chromium sulfate and eliminating the precipitate by centrifugation filtration in order to isolate the chromium methanesulfonate in solution.
- This process can be carried out at room temperature and at atmospheric pressure. When precipitating, barium sulfate shifts the balance and leads to chromium methanesulfonate without any special precautions.
- the chromium content of the chromium methanesulfonate solution thus prepared is determined by atomic absorption: 35 g Cr / l.
- This solution can be used directly in tanning or else the chromium salt can be isolated in crystallized form by precipitation with acetone.
- the quantities of added products are expressed as a percentage by weight of the weight of the pickled skins.
- the skins are removed from the tanning bath and left to stand for 48 hours (extended skins stacked on top of each other).
- the tanned hides obtained are subjected to a visual analysis: the chromium is uniformly distributed and fixed; the hides have a shrinking temperature of more than 100 ° C, which characterizes a good quality of tanning.
- the quantities of products added are given as a percentage by weight of the weight of the tripe skins.
- the two batches of skins a) and b) are fed, then dyed in a conventional manner.
- an industrial pass of one tonne of skins made it possible to quantify the increase in surface area.
- a reference pass measures approximately 8000 ft2 (approximately 743 m2).
- a pass treated with methanesulfonic acid measures approximately 8,400 square feet (approximately 780 m2), a considerable increase in surface area of 5%.
- the quantities of added products are expressed as a percentage by weight of the weight of the pickled skins.
- chromium sulphate (basicity 33 ° chromium content: 26%) is then added to the bath, an operation which is followed by the addition after 1 hour, of 1% of sodium formate and then of 4% of sodium hydrogen carbonate. in four times in three hours; the end of tanning pH is 4.1. Still in the tanning bath, the skins are heated for one hour at 50 ° C.
- the dye is uniformly distributed, as is the chromium, as evidenced by a temperature of this retraction greater than 100 ° C.
- the quantities of products added are given as a percentage by weight of the weight of dry tanned hides.
- the dyed skins are then put in the wind and dried.
- the quantities of added products are given as a percentage by weight of the weight of the pickled skins.
- the skins are placed in a water bath (250%) to which are added 30% of quebracho extract in 3 times in 2 hours. The skins are left in the bath with stirring overnight, then rinsed, bleached and nourished.
- bleaching and nourishment are carried out in the conventional way: it is placed in a bath of 200% water at 50 ° C. to which 1% of oxalic acid is added, then 3% of sodium thiosulfate, and finally 3% food.
- the other two skins undergo the same treatment supplemented by the addition of 1% methanesulfonic acid to 70% in two batches, after the action of oxalic acid (0.21 mole of CH3 SO3 ⁇ ion per kg of dry skin ).
- the three dry skins have a shrink temperature of 80-85 ° C, characteristic of good vegetable tanning and are, as before, subject to the appreciation of professionals.
- the two skins treated with methanesulfonic acid have greater flexibility and above all a particularly silky feel, compared to the skin treated in a conventional manner.
- Tripe lambskins are picked with methanesulfonic acid according to Example 2, chrome tanned in the traditional way, then dyed with fixing of the dye by methanesulfonic acid according to Example 4.
- Example 2 As in Example 2, an increase in surface area of the order of 5% is measured, accompanied by a homogenization of the fat content and therefore of the thickness.
- Example 7 Use of chromium methanesulfonate in mixed medium
- the quantities of products added are expressed as a percentage by weight relative to the weight of the pickled skins.
- Two skins (1000 g) of degreased and pickled lambs are placed in 400% brine bath at 8 ° Baumé (ie 88.24 g / l NaCl) for one hour; by spinning), the humidity of the skins is reduced to 200% of water relative to the dry weight.
- Dry tanned hides are subjected to a visual analysis: the chromium is uniformly distributed and fixed; the hides have a shrinking temperature above 100 ° C, characteristic of good tanning.
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Treatment And Processing Of Natural Fur Or Leather (AREA)
Abstract
Description
L'invention concerne un procédé de traitement d'articles de mégisserie ou tannerie constitués de tissus collagéniques tels que peaux ou cuirs, en vue de réaliser un effet de relâchement des fibres des tissus et de répartition interne des graisses, conduisant à une augmentation de surface des peaux et à une homogénéisation de leur épaisseur, et également à une amélioration des qualités de surface des articles (toucher, aspect, régularité,...) et de leur souplesse.The invention relates to a method of treating tanneries or tannery made from collagenous fabrics such as skins or leathers, with a view to achieving a loosening effect on the fibers of the fabrics and internal distribution of fats, leading to an increase in surface area. skins and a homogenization of their thickness, and also an improvement in the surface qualities of the articles (feel, appearance, regularity, ...) and their flexibility.
De nombreuses études ont été menées pour tenter d'améliorer les procédés de fabrication du cuir, généralement dans le but de limiter les rejets d'effluents polluants ; ces études ont visé à améliorer certaines étapes de fabrication telles que picklage, tannage, teinture ou opérations de finissage. Certains procédés existants peuvent conduire à une certaine amélioration des cuirs obtenus (qualités de surface), mais cette amélioration est insuffisante, surtout lorsque les peaux de départ sont des peaux de qualité dite inférieure ou ayant souffert (par exemple parce qu'ayant subi un délainage à l'échauffe...). Actuellement, la fabrication de cuirs de qualité satisfaisante à partir de certaines peaux de qualité inférieure impose un surcoût très important (dû à l'addition de produits, à la durée du cycle accrue et à la multiplicité des opérations) qui limite l'intérêt des traitements supplémentaires de sorte que ces peaux demeurent généralement cantonnées à la fabrication de produits bas de gamme.Many studies have been carried out to try to improve the leather manufacturing processes, generally with the aim of limiting the discharge of polluting effluents; these studies aimed to improve certain manufacturing steps such as pickling, tanning, dyeing or finishing operations. Certain existing processes can lead to a certain improvement in the leathers obtained (surface qualities), but this improvement is insufficient, especially when the starting skins are skins of so-called lower quality or having suffered (for example because having undergone a stripping. warming up ...). Currently, the production of satisfactory quality leathers from certain inferior skins imposes a very significant additional cost (due to the addition of products, the increased cycle time and the multiplicity of operations) which limits the interest of additional treatments so that these skins generally remain confined to the manufacture of low-end products.
De plus, les agents de traitement existants qui conduisent à une certaine amélioration des cuirs sont en général spécifiques à telle ou telle opération (par exemple acide acétique et adjuvant pour le picklage des peaux, produits cationique/anionique ou tensio-actifs pour la nourriture des cuirs...) et ne peuvent être utilisés à un autre stade de la fabrication.In addition, the existing treatment agents which lead to a certain improvement in the leathers are generally specific to such or such operation (for example acetic acid and adjuvant for the pickling of skins, cationic / anionic products or surfactants for the food of leathers ...) and cannot be used at any other stage of production.
Le problème de l'amélioration des qualités de surface et de souplesse du cuir est donc mal résolu à l'heure actuelle, ce qui s'explique par la nature très spécifique des peaux qui sont constituées de tissus collagéniques très sensibles à l'hydrolyse et aux agents bactériens : la plupart des agents entraîne une dégradation de ces tissus et le nombre de produits chimiques compatibles est très limité. De plus, aucun de ces agents ne permet d'homogénéiser de façon sensible l'épaisseur des peaux et d'obtenir une augmentation significative de leur superficie.The problem of improving the surface qualities and flexibility of leather is therefore poorly resolved at the present time. current, which is explained by the very specific nature of the skins which are made up of collagenous tissues very sensitive to hydrolysis and to bacterial agents: most agents cause degradation of these tissues and the number of compatible chemicals is very limit. In addition, none of these agents makes it possible to substantially homogenize the thickness of the skins and to obtain a significant increase in their surface area.
Par ailleurs, parmi les tensio-actifs qui sont utilisés pour nourrir les peaux, c'est-à-dire apporter à celles-ci une matière grasse on peut citer les huiles minérales du type sulfonates à longue chaîne carbonée, qui sont utilisées en émulsion ; les documents antérieurs suivants évoquent ce type de tensio-actifs et leur application à la nourriture des peaux : Chemical Abstracts, vol. 109, abrégé n° 192 521 j "Study of chrome emulsion tanning using products containing water -and oil- soluble sulfonates, 1", Abdullaev N.I. ; Abrokov, F.A. ; Bekharskii, V.I, ; Ostrovskii, Yu. M. (Kiev.Tekhnol.Legk.Prom-sti) Izv.Vyssh. Uchebn. Zaved., Tekhnol.Legk.Prom-sti, 1988,31(4),63-6 ; Chemical Abstracts, vol. 110, abrégé n° 40746 u, "Study of chrome emulsion tanning using products containing water -and oil- soluble sulfonates, 2", Abdullaev N.I. ; Abrokov, F.A. ; Bekharskii, V.I, ; Ostrovskii, Yu. M. Izv.Vyssh. Uchebn. Zaved., Tekhnol.Legk.Prom-sti, 1988,31(5),74-6 ; Chemical Abstracts, vol. 100, abrégé n° 70309 q "Treatment of sheepskins", Sakiev, B., Iskakov, D.Ch. ; Bulanov, P.P. (Dzhambul Technological Institute of Light and Food Industry) SU A-1 057 544, 30.11.83 ; Chemical Abstracts, vol. 100, abrégé n° 158525t "Non pickling method of tanning and fatliquoring using cationic fatliquoring emulsion" ; Sakiev, A.M. ; Bekezhanov, S.S. ; (Dzhambul Technological Institute of Light and Food Industry) Kozh.-Obuvn.Prom-st. 1984(1) 40-41 ; Chemical Abstracts, vol. 98, abrégé n° 109257p, "Improving the lightfastness of dyed leathers by tanning agents". Nowak,R. ; Rev.Tech.Ind.Cuir 1982, 74(11), 376-80 ; brevet FR-A-2.249.952 "Procédé pour la préparation et l'utilisation d'un agent de tannage au chrome nourrissant". Ces publications visent des composés sulfonés ayant des chaînes d'au moins 8 carbones, préférentiellement entre 20 et 30 carbones, qui présentent des propriétés émulsifiantes.Furthermore, among the surfactants which are used to nourish the skins, that is to say to provide them with a fatty substance, mention may be made of mineral oils of the sulfonate type with a long carbon chain, which are used in emulsion ; the following previous documents mention this type of surfactants and their application to skin food: Chemical Abstracts, vol. 109, abstract no. 192 521 j "Study of chrome emulsion tanning using products containing water -and oil- soluble sulfonates, 1", Abdullaev NI; Abrokov, FA; Bekharskii, VI,; Ostrovskii, Yu. M. (Kiev.Tekhnol.Legk.Prom-sti) Izv.Vyssh. Uchebn. Zaved., Tekhnol.Legk.Prom-sti, 1988,31 (4), 63-6; Chemical Abstracts, vol. 110, abstract no.40746 u, "Study of chrome emulsion tanning using products containing water -and oil- soluble sulfonates, 2", Abdullaev NI; Abrokov, FA; Bekharskii, VI,; Ostrovskii, Yu. M. Izv.Vyssh. Uchebn. Zaved., Tekhnol.Legk.Prom-sti, 1988,31 (5), 74-6; Chemical Abstracts, vol. 100, abstract n ° 70309 q "Treatment of sheepskins", Sakiev, B., Iskakov, D.Ch. ; Bulanov, PP (Dzhambul Technological Institute of Light and Food Industry) SU A-1 057 544, 30.11.83; Chemical Abstracts, vol. 100, abstract n ° 158525t "Non pickling method of tanning and fatliquoring using cationic fatliquoring emulsion"; Sakiev, AM; Bekezhanov, SS; (Dzhambul Technological Institute of Light and Food Industry) Kozh.-Obuvn.Prom-st. 1984 (1) 40-41; Chemical Abstracts, vol. 98, abstract no.109257p, "Improving the lightfastness of dyed leathers by tanning agents". Nowak, R. ; Rev.Tech.Ind.Cuir 1982, 74 (11), 376-80; Patent FR-A-2,249,952 "Process for the preparation and use of a nourishing chromium tanning agent". These publications target sulfonated compounds having chains of at least 8 carbons, preferably between 20 and 30 carbons, which have emulsifying properties.
La fonction de tensio-actif de ces composés sulfonés à longue chaîne carbonée est bien connue et leurs propriétés émulsifiantes permettent une pénétration des graisses qu'ils véhiculent, à l'intérieur des peaux : ils réalisent ainsi un remplissage des peaux, qui conduit à une certaine amélioration de leur qualité de souplesse et de toucher. Cette opération impliquant un apport externe de matière grasse dans la peau est désignée par "opération de nourriture". Toute fois ces produits et leur matière grasse sont définitivement fixés sur et dans la peau : cet apport modifie la structure du cuir et lui fait perdre une partie de ses propriétés originelles. De plus, ces produits ne corrigent pas les irrégularités d'épaisseur de la peau, puisque les graisses propres de celle-ci, dont la répartition hétérogène est la cause desdites irrégularités d'épaisseur, ne sont pas affectées. En outre la superficie de la peau demeure inchangée. Il est à noter que certains sulfonates à longues chaînes sont utilisés comme tannin synthétique mais apportent une coloration brune des cuirs lors du tannage (Chemical Abstracts, vol. 93, n° 8, août 1980, pages 107-108, abrégé n° 73793r, Colombus, Ohio, US ; L.V. TELENKOVA : "New synthetic tanning agent", & KOZH.-OBUVN. PROM-ST. 1980, 22(4), 34-6).The surfactant function of these sulfonated compounds with a long carbon chain is well known and their emulsifying properties allow penetration of the fats which they transport, inside the skins: they thus fill the skins, which leads to a some improvement in their quality of flexibility and touch. This operation involving an external supply of fat in the skin is called "food operation". However, these products and their fat are permanently fixed on and in the skin: this contribution modifies the structure of the leather and causes it to lose some of its original properties. In addition, these products do not correct irregularities in the thickness of the skin, since the own fats thereof, the heterogeneous distribution of which is the cause of said irregularities in thickness, are not affected. In addition, the surface area of the skin remains unchanged. It should be noted that certain long-chain sulfonates are used as synthetic tannin but provide a brown coloration of the leathers during tanning (Chemical Abstracts, vol. 93, n ° 8, August 1980, pages 107-108, abbreviated n ° 73793r, Colombus, Ohio, US; LV TELENKOVA: "New synthetic tanning agent", & KOZH.-OBUVN. PROM-ST. 1980, 22 (4), 34-6).
Un des défauts essentiels des peaux réside dans les irrégularités d'épaisseur qu'elles présentent : actuellement, aucun procédé de traitement n'est apte à permettre d'obtenir une uniformité d'épaisseur des peaux et d'en augmenter la surface, tout en préservant leur intégrité. Il est important de souligner que la plupart des peaux sont vendues à la surface et qu'un gain sensible de superficie, associé à une épaisseur plus uniforme représente un avantage industriel considérable.One of the essential defects of the skins resides in the thickness irregularities which they present: currently, no treatment process is capable of making it possible to obtain a uniform thickness of the skins and to increase the surface thereof, while preserving their integrity. It is important to emphasize that most skins are sold on the surface and that a significant gain in surface area, associated with a more uniform thickness represents a considerable industrial advantage.
La présente invention se propose de fournir un nouveau procédé de traitement de peaux ou cuirs constitués de tissus collagéniques en vue d'en homogénéiser l'épaisseur et d'en augmenter la surface tout en préservant leur intégrité.The present invention proposes to provide a new process for the treatment of skins or hides made up of collagenous tissues with a view to homogenizing their thickness and increasing their surface area while preserving their integrity.
Un objectif de l'invention est d'obtenir ce résultat sans apport d'un produit externe dans la structure collagénique, en particulier sans apport de matière grasse.An objective of the invention is to obtain this result without adding an external product to the collagen structure, in particular without adding fat.
Un autre objectif est d'améliorer concomitamment les qualités de surface des peaux (toucher, aspect) et leur souplesse, et ce, de façon plus prononcée que les procédés connus.Another objective is to concomitantly improve the surface qualities of the skins (feel, appearance) and their flexibility, and this, in a more pronounced manner than the known methods.
Un autre objectif est de fournir un procédé de coût compatible avec une valorisation des peaux de qualité inférieure dans de bonnes conditions de rentabilité.Another objective is to provide a cost process compatible with the valuation of lower quality skins under good profitability conditions.
Un autre objectif est de fournir un procédé susceptible d'être mis en oeuvre à différents stades de la fabrication du cuir (notamment aux stades qui impliquent un abaissement du pH).Another objective is to provide a process capable of being implemented at different stages of the manufacture of leather (in particular at the stages which involve a lowering of the pH).
A cet effet, le procédé conforme à l'invention pour traiter des articles de mégisserie et tannerie constitués de tissus collagéniques tels que peaux et cuir consiste à mettre les peaux ou cuirs au contact d'acide méthanesulfonique CH₃ SO₃H ou d'ions méthanesulfonate CH₃ SO₃⁻ en milieu acide. Les peaux peuvent en particulier être mises au contact d'acide méthanesulfonique en milieu aqueux ou milieu mixte eau/solvant organique. (Par la suite, on désignera par "milieu mixte" un milieu contenant un ou des solvants organiques et de l'eau, même si cette dernière reste en proportion très minoritaire). D'après les expérimentations effectuées, la quantité minimale d'acide méthanesulfonique ou d'ions méthanesulfonate en milieu acide nécessaire pour conduire à un résultat sensible est de l'ordre de 0,05 mole par kg de peaux ou cuirs secs. (Par un poids de "peaux sèches", l'on vise le poids des peaux au début du traitement, déduction faite du poids d'eau liée).To this end, the process according to the invention for treating tanneries and tanning articles made up of collagenous fabrics such as skins and leather consists in bringing the skins or leathers in contact with methanesulfonic acid CH₃ SO₃H or methanesulfonate ions CH₃ SO₃ ⁻ In an acid medium. The skins can in particular be brought into contact with methanesulfonic acid in an aqueous medium or a mixed water / organic solvent medium. (Subsequently, the term "mixed medium" will mean a medium containing one or more organic solvents and water, even if the latter remains in very small proportion). According to the experiments carried out, the minimum quantity of methanesulfonic acid or of methanesulfonate ions in acid medium necessary to lead to a sensitive result is of the order of 0.05 mol per kg of dry skins or hides. (By a weight of "dry skins", we mean the weight of the skins at the start of the treatment, minus the weight of bound water).
L'invention est née de l'observation fortuite d'un phénomène inattendu et remarquable : lorsque des peaux ou cuirs sont mis en contact avec l'acide méthanesulfonique ou les ions méthanesulfonate en milieu acide, quel que soit le stade de la fabrication où cette mise en contact est pratiquée, l'on constate un effet de relâchement des fibres des tissus collagéniques et de répartition interne des graisses propres : l'épaisseur des peaux est rendue plus uniforme, cependant que la surface de celles-ci est notablement augmentée (de 5 % environ). L'acide méthanesulfonique ou les ions méthanesulfonate se retrouvent en quasi-totalité en fin de traitement dans le bain, de sorte qu'aucun apport n'a été effectué dans la peau. Le mécanisme d'action est difficile à expliquer à l'heure actuelle : il semble que les ions méthanesulfonate se fixent temporairement sur les graisses propres de la peau pour en accroître la mobilité et permettre une migration des graisses des parties les plus épaisses de la peau (donc les plus grasses) pour produire un effet d'étalement, conduisant à une augmentation de la surface et une homogénéisation de l'épaisseur ; cette fixation se détruit ensuite pour des raisons mal connues et le méthanesulfonate repasse dans le bain où il est récupéré. La quantité totale d'acide méthanesulfonique ou d'ions méthanesulfonate est préférentiellement comprise entre 0,1 et 2 moles par kg de peaux sèches : cette quantité reste donc très faible par rapport à la quantité de graisse propre des peaux, de sorte que les actions ci-dessus évoquées sont de type catalytique.The invention was born from the chance observation of an unexpected and remarkable phenomenon: when skins or leathers are brought into contact with methanesulfonic acid or methanesulfonate ions in an acid medium, whatever the stage of manufacture where this contacting is practiced, there is an effect of loosening of the fibers of the collagen tissues and internal distribution of clean fats: the thickness of the skins is made more uniform, while the surface of these is significantly increased (by about 5%). Methanesulfonic acid or methanesulfonate ions are found almost entirely at the end of treatment in the bath, so that no contribution has been made in the skin. The mechanism of action is difficult to explain at present: it seems that the methanesulfonate ions temporarily bind to the clean fats of the skin to increase mobility and allow migration of fats from the thickest parts of the skin. (therefore the fatty ones) to produce a spreading effect, leading to an increase in the surface and a homogenization of the thickness; this fixation is then destroyed for reasons that are not well known and the methanesulfonate returns to the bath where it is recovered. The total amount of methanesulfonic acid or methanesulfonate ions is preferably between 0.1 and 2 moles per kg of dry skin: this amount therefore remains very small compared to the amount of clean fat of the skin, so that the actions above mentioned are catalytic type.
Il convient de souligner que l'acide méthanesulfonique ou les ions méthanesulfonate contiennent un seul carbone et ne sont pas des tensio-actifs : ils ont des propriétés totalement différentes de celles des sulfonates à longue chaîne utilisés pour nourrir les peaux grâce aux matières grasses qu'ils apportent à celles-ci. Les effets sur les peaux du procédé de l'invention sont très différents de ceux d'une opération de nourriture puisque, dans le cas de l'invention, le composé est quasi-totalement récupéré et n'est pas fixé définitivement dans ou sur la peau : il agit sur les graisses propres de celle-ci et préserve l'intégrité des peaux sans apport externe de matière dans leur texture, ce qui n'est pas le cas des tensio-actifs sus-visés. Les ions méthanesulfonate se rapprochent davantage, de par leur structure chimique et leurs propriétés connues, des ions sulfate ; ces derniers sont utilisés depuis longtemps dans les opérations de tannage des peaux et cuirs sans conduire aux résultats fournis par les ions du procéde visé par l'invention (à savoir : action sur les graisses propres de la peau conduisant à une homogénéisation d'épaisseur et à une augmentation de surface).It should be emphasized that methanesulfonic acid or methanesulfonate ions contain a single carbon and are not surfactants: they have properties completely different from those of the long chain sulfonates used to nourish skins thanks to the fats that they bring to these. The effects on the skin of the process of the invention are very different from those of a food operation since, in the case of the invention, the compound is almost completely recovered and is not definitively fixed in or on the skin: it acts on its own fats and preserves the integrity of the skins without external material supply in their texture, which is not the case with the above-mentioned surfactants. Methanesulfonate ions are closer, by their chemical structure and known properties, to sulfate ions; the latter have been used for a long time in tanning operations for hides and skins without leading to the results provided by the ions of the process targeted by the invention (namely: action on the clean fats of the skin leading to homogenization of thickness and increase in surface).
L'acide méthanesulfonique qui conduit en milieu aqueux aux ions méthanesulfonate est un acide organique fort, bien connu en soi. Le brevet US-2 297 722 en décrit un procédé de fabrication. Il est actuellement utilisé essentiellement comme substituant de l'acide fluoroborique dans les bains de galvanoplastie, comme agent de piégeage des métaux lourds dans les dérivés pétroliers, comme inhibiteur de corrosion à l'égard des alliages de magnésium, ou comme catalyseur de certaines réactions (estérification, alkylation, polymérisation d'oléfines...).The methanesulfonic acid which leads in an aqueous medium to methanesulfonate ions is a strong organic acid, well known in itself. US Patent 2,297,722 describes a manufacturing process. It is currently used essentially as a substitute for fluoroboric acid in electroplating baths, as a trapping agent for heavy metals in petroleum derivatives, as a corrosion inhibitor against magnesium alloys, or as a catalyst for certain reactions ( esterification, alkylation, polymerization of olefins ...).
Par ailleurs, les essais ont également permis de constater que le procédé de l'invention permettait d'obtenir une amélioration reproductible, très significative de l'état de surface des peaux et de leur souplesse. De plus, tous les méthanesulfonates métalliques étant très solubles dans l'eau, le procédé de l'invention évite tout risque de précipitation de sels insolubles (sulfate de calcium par exemple) susceptibles de se déposer sur ou dans les peaux au cours du cycle de fabrication et de provoquer une dégradation de leurs qualités de surface ou de souplesse.Furthermore, the tests also made it possible to note that the process of the invention made it possible to obtain a reproducible, very significant improvement in the surface condition of the skins and their suppleness. In addition, all the metallic methanesulfonates being very soluble in water, the process of the invention avoids any risk of precipitation of insoluble salts (calcium sulfate for example) capable of being deposited on or in the skins during the cycle of manufacturing and cause a degradation of their surface qualities or flexibility.
De plus, on a pu constater que l'ensemble des résultats sus-évoqués fournis par les ions méthanesulfonate se produisaient quel que soit le stade de fabrication où ils étaient introduits.In addition, it has been observed that all of the above-mentioned results provided by the methanesulfonate ions occur regardless of the stage of manufacture where they were introduced.
Le cycle de fabrication du cuir à partir de peaux brutes comprend généralement une opération de picklage consistant à acidifier ces peaux. La mise en contact des peaux brutes ou en tripes avec les ions méthanesulfonate peut être effectuée lors de cette opération de picklage en utilisant l'acide méthanesulfonique éventuellement combiné à un autre acide (notamment acide sulfurique).The leather manufacturing cycle from raw hides generally includes a pickling operation consisting in acidifying these hides. Bringing raw or tripe skins into contact with methanesulfonate ions can be carried out during this pickling operation using methanesulfonic acid optionally combined with another acid (in particular sulfuric acid).
Le cycle de fabrication comprend également une opération de tannage. La mise au contact peut être effectuée lors de cette opération en introduisant les ions méthanesulfonate dans le bain de tannage. L'agent de tannage de ce bain peut être de tout type connu, minéral, végétal et/ou synthétique et le bain contient alors un mélange de cet agent et d'acide méthanesulfonique ou de sel de cet acide.The manufacturing cycle also includes a tanning operation. The contacting can be carried out during this operation by introducing the methanesulfonate ions into the tanning bath. The tanning agent for this bath can be of any known type, mineral, vegetable and / or synthetic and the bath then contains a mixture of this agent and methanesulfonic acid or a salt of this acid.
Il est également possible d'effectuer un tannage au chrome avec un agent spécifique constitué par du méthanesulfonate de chrome en milieu aqueux ou mixte. Ce composé libère à la fois les ions métalliques assurant le tannage et les ions méthanesulfonate conduisant aux résultats précités.It is also possible to carry out chromium tanning with a specific agent consisting of chromium methanesulfonate in an aqueous or mixed medium. This compound releases both the metal ions ensuring the tanning and the methanesulfonate ions leading to the abovementioned results.
Le cycle de fabrication des cuirs comprend également une opération de teinture, la mise au contact du colorant étant généralement assurée à pH proche de la neutralité et la fixation de celui-ci à pH inférieur. La mise au contact des ions méthanesulfonate peut être effectuée lors de cette opération en utilisant l'acide méthanesulfonique éventuellement combiné à un autre acide organique (notamment acide formique ou acide acétique).The leather manufacturing cycle also includes a dyeing operation, bringing the dye into contact is generally ensured at a pH close to neutral and fixing it at a lower pH. The methanesulfonate ions can be brought into contact during this operation by using methanesulfonic acid optionally combined with another organic acid (in particular formic acid or acetic acid).
Le cas échéant, les peaux peuvent être mises au contact avec les ions méthanesulfonate à plusieurs reprises et notamment aux trois stades de fabrication précités : picklage, tannage et teinture. Ce mode de mise en oeuvre conduit notamment à l'avantage pratique suivant : pour obtenir une qualité donnée, la concentration en ions méthanesulfonate est plus faible à chaque opération (par rapport à une mise en contact unique), ce qui évite une trop forte diminution du pH, qui pourrait être préjudiciable à la qualité des peaux.If necessary, the skins can be brought into contact with the methanesulfonate ions several times and in particular at the three aforementioned manufacturing stages: pickling, tanning and dyeing. This mode of implementation leads in particular to the following practical advantage: to obtain a given quality, the concentration of methanesulfonate ions is lower at each operation (compared to a single contacting), which avoids too great a reduction pH, which could be detrimental to the quality of the skins.
D'après les essais effectués, la quantité optimale totale des ions méthanesulfonate, qu'il y a lieu de mettre au contact des peaux en une ou plusieurs fois au cours du cycle de fabrication pour obtenir une amélioration prononcée de leurs qualités sans gaspillage de produit, semble devoir être comprise, comme déjà indiqué, entre 0,1 et 2,0 moles par kg de peaux ou cuirs secs.According to the tests carried out, the total optimal quantity of methanesulfonate ions, which should be brought into contact with the skins in one or more stages during the manufacturing cycle to obtain a marked improvement in their qualities without wasting product , seems to be understood, as already indicated, between 0.1 and 2.0 moles per kg of dry skins or hides.
Il est à noter que la fabrication d'un méthanesulfonate métallique est connue en soi. La publication "R.C. PAUL et al, Indian Journ. of Chem., vol. 12, Août 74, pages 825-826" décrit en particulier un procédé de fabrication à partir d'acide méthanesulfonique qui consiste à faire réagir cet acide sur un chlorure métallique à 170° C et sous vide poussé. Toutefois, ces conditions sévères obèrent le prix du produit obtenu, d'autant que celui-ci est ensuite difficile à isoler.It should be noted that the manufacture of a metallic methanesulfonate is known per se. The publication "RC PAUL et al, Indian Journ. Of Chem., Vol. 12, August 74, pages 825-826 "describes in particular a manufacturing process from methanesulfonic acid which consists in reacting this acid on a metal chloride at 170 ° C and under high vacuum. However, these severe conditions affect the price of the product obtained, especially since it is then difficult to isolate.
Est également décrit ici un procédé de fabrication de méthanesulfonate de chrome permettant d'obtenir ce composé à un coût considérablement réduit.Also described here is a process for manufacturing chromium methanesulfonate making it possible to obtain this compound at a considerably reduced cost.
Ce procédé consiste à faire réagir l'acide méthanesulfonique sur un sel de baryum, puis à faire réagir le méthanesulfonate de baryum obtenu avec du sulfate de chrome et à éliminer par filtration au centrifugation le précipité afin d'isoler le méthanesulfonate de chrome en solution. Ce procédé peut être mis en oeuvre à température ambiante et à la pression atmosphérique. En précipitant, le sulfate de baryum déplace l'équilibre et conduit au méthanesulfonate de chrome sans précaution particulière.This process consists in reacting methanesulfonic acid on a barium salt, then reacting the barium methanesulfonate obtained with chromium sulfate and eliminating the precipitate by centrifugation filtration in order to isolate the chromium methanesulfonate in solution. This process can be carried out at room temperature and at atmospheric pressure. When precipitating, barium sulfate shifts the balance and leads to chromium methanesulfonate without any special precautions.
L'invention est illustrée dans les exemples de mise en oeuvre qui suivent.The invention is illustrated in the examples of implementation which follow.
Le procédé de fabrication nécessite deux étapes :
- préparation de méthanesulfonate de baryum :
A une solution de 200 g d'hydroxyde de baryum octohydraté dissous dans 280 ml d'eau permutée, on additionne 170 ml d'acide méthanesulfonique à 70 %, goutte à goutte.
Après 1 h 30 d'agitation à 55° C, l'eau est évaporée sous vide jusqu'à précipitation du méthanesulfonate de baryum, qui est isolé sous forme de cristaux blancs par une succession de filtrations et ce lavages à l'alcool éthylique. - fabrication du méthanesulfonate de chrome :
A une solution de 110 g de sulfate de chrome dissous dans 350 ml d'eau permutée, on additionne 176 g de méthanesulfonate de baryum, obtenu lors de la première étape.
Après 30 minutes d'agitation à température ambiante, le précipité de sulfate de baryum formé est éliminé par centrifugation (1 h à 4000 tr/min.)
- barium methanesulfonate preparation:
To a solution of 200 g of barium hydroxide octohydrate dissolved in 280 ml of deionized water, 170 ml of 70% methanesulfonic acid are added dropwise.
After stirring for 1 h 30 at 55 ° C., the water is evaporated in vacuo until precipitation of the barium methanesulfonate, which is isolated in the form of white crystals by a succession of filtrations and this washing with ethyl alcohol. - manufacture of chromium methanesulfonate:
To a solution of 110 g of chromium sulphate dissolved in 350 ml of deionized water, 176 g of barium methanesulphonate, obtained during the first step, are added.
After 30 minutes of stirring at temperature ambient, the precipitate of barium sulfate formed is removed by centrifugation (1 h at 4000 rpm.)
La teneur en chrome de la solution de méthanesulfonate de chrome ainsi préparée est déterminée par absorption atomique : 35 g Cr/l.The chromium content of the chromium methanesulfonate solution thus prepared is determined by atomic absorption: 35 g Cr / l.
Cette solution peut être utilisée directement en tannage ou bien le sel de chrome peut être isolé sous forme cristallisée par précipitation à l'acétone.This solution can be used directly in tanning or else the chromium salt can be isolated in crystallized form by precipitation with acetone.
Les quantités de produits ajoutés sont exprimées en pourcentage pondéral du poids des peaux picklées.The quantities of added products are expressed as a percentage by weight of the weight of the pickled skins.
Quatre peaux (2800 g) d'agneaux de Nouvelle-Zélande humides, dégraissées et picklées sont placées dans 250 % de bain de saumure à 8° Baumé (88,24 g/l de NaCl) pendant 15 minutes.Four skins (2800 g) of wet, defatted and pickled New Zealand lambs are placed in 250% 8 ° Baumé brine bath (88.24 g / l NaCl) for 15 minutes.
1728 ml de solution de méthanesulfonate de chrome obtenue précédemment, soit 60,5 g de Cr, est introduite en une fois (quantité d'ions CH₃ SO₃⁻ égale à 3,56 moles rapportée à 1 kg de peaux sèches). Après une heure d'agitation, on basifie progressivement en ajoutant 1 % de formiate de sodium, puis 4 % d'hydrogénocarbonate de sodium toutes les heures pendant 4 heures. Le pH de fin de tannage est de 3,9.1728 ml of chromium methanesulfonate solution obtained previously, ie 60.5 g of Cr, is introduced at once (quantity of CH₃ SO₃⁻ ions equal to 3.56 moles relative to 1 kg of dry skin). After one hour of stirring, it is gradually basified by adding 1% sodium formate, then 4% sodium hydrogencarbonate every hour for 4 hours. The end of tanning pH is 3.9.
On retire les peaux du bain de tannage et on les laisse au repos pendant 48 heures (peaux étendues empilées les unes sur les autres).The skins are removed from the tanning bath and left to stand for 48 hours (extended skins stacked on top of each other).
Les peaux tannées obtenues font l'objet d'une analyse visuelle : le chrome est uniformément réparti et fixé ; les peaux ont une température de rétraction supérieure à 100° C, ce qui caractérise une bonne qualité de tannage.The tanned hides obtained are subjected to a visual analysis: the chromium is uniformly distributed and fixed; the hides have a shrinking temperature of more than 100 ° C, which characterizes a good quality of tanning.
Ces peaux subissent ensuite une procédure traditionnelle de nourriture, teinture et séchage.These skins then undergo a traditional feeding, dyeing and drying procedure.
Ces cuirs finis ont été appréciés par un panel de professionnels du cuir et caractérisés ainsi : très bon tannage très bonne souplesse excellent toucher soyeux légèrement cireux. Ces qualités étaient significativement meilleures que celles de peaux analogues traitées dans les mêmes conditions, mais avec du sulfate de chrome.These finished leathers were appreciated by a panel of leather professionals and characterized as follows: very good tanning very good flexibility excellent silky touch slightly waxy. These qualities were significantly better than those of similar skins treated under the same conditions, but with chromium sulphate.
Les quantités de produits ajoutés sont données en pourcentage pondéral du poids des peaux en tripes.The quantities of products added are given as a percentage by weight of the weight of the tripe skins.
6 peaux d'agneaux de Nouvelle-Zélande (qualité inférieure) dégraissées, humides, sont divisées en deux parties de façon longitudinale afin de mieux apprécier les améliorations de qualité apportées par l'invention.
- a) 6 demi-peaux sont picklées de façon traditionnelle (50 % de bain de saumure à 8° Baumé (88,24 g/l de NaCl) et 2 % d'acide formique) et tannées de façon classique, après une nuit d'agitation dans le bain de picklage.
- b) 6 demi-peaux sont picklées selon l'invention, c'est-à-dire par addition de 1 % d'acide méthanesulfonique à 70 % en deux fois pendant une heure, puis de 1,5 % d'acide formique en trois fois durant 1 heure 30 (quantité d'ions CH₃ SO₃⁻ égale à 0,36 mole rapportée à 1 kg de peaux sèches).
- a) 6 half-skins are picked in the traditional way (50% brine bath at 8 ° Baumé (88.24 g / l NaCl) and 2% formic acid) and tanned in the conventional way, after one night d agitation in the pickling bath.
- b) 6 half-skins are picked according to the invention, that is to say by adding 1% of 70% methanesulfonic acid in two batches for one hour, then 1.5% of formic acid in three times during 1 hour 30 (quantity of CH₃ SO₃⁻ ions equal to 0.36 mole compared to 1 kg of dry skin).
Après une nuit d'agitation dans le bain de picklage, ces peaux sont tannées de façon classique.After one night of agitation in the pickling bath, these skins are tanned in a conventional manner.
Après 48 heures de repos, les deux lots de peaux a) et b) sont nourris, puis teints de façon classique.After 48 hours of rest, the two batches of skins a) and b) are fed, then dyed in a conventional manner.
Les cuirs ainsi finis ont été appréciés par un panel de professionnels qui les a classés en deux catégories :
- la première (a) correspondant au lot picklé à l'acide formique présente les caractéristiques habituelles de peaux tannées au chrome : bonne résistance thermique et à la déchirure, bonne souplesse, mais qualités de surface très moyennes. L'épaisseur des peaux dans la partie la plus grasse (collet) est d'environ 4 mm et dans la partie la moins grasse (flancs) d'environ 2 mm.
- la seconde (b) correspondant au lot traité à l'acide méthanesulfonique présente ces mêmes caractéristiques de résistance thermique et à la déchirure, accompagnées d'une souplesse accrue, d'une sensation de "plein" et d'un toucher particulièrement soyeux du côté fleur comme du côté chair. On constate une uniformisation de l'épaisseur des peaux qui passe à environ 3 mm pour le collet et à 2,5 mm pour les flancs.
- the first (a), corresponding to the lot formic acid pickled, has the usual characteristics of chrome tanned skins: good thermal and tear resistance, good flexibility, but very average surface qualities. The thickness of the skins in the fattyest part (collar) is approximately 4 mm and in the least fatty part (flanks) approximately 2 mm.
- the second (b) corresponding to the batch treated with methanesulfonic acid has these same characteristics of thermal and tear resistance, accompanied by increased flexibility, a feeling of "fullness" and a particularly silky feel on the side flower like on the flesh side. There is a uniformity of the thickness of the skins which passes to approximately 3 mm for the collar and 2.5 mm for the sides.
Ceci s'explique par le fait que le taux de matières grasses qui est en moyenne pour ces peaux, de 8,3 % (par rapport au poids sec) dans le collet et de 6,5 % (par rapport au poids sec) dans les flancs, passe à 6,75 % dans le collet et reste à 6,5 % dans les flancs.This is explained by the fact that the fat content which is on average for these skins, of 8.3% (relative to the dry weight) in the collar and 6.5% (relative to the dry weight) in flanks, increases to 6.75% in the collar and remains at 6.5% in the flanks.
Les opérations mécaniques de "ponçage" pour égaliser l'épaisseur sont alors éliminées et les qualités de résistance intrinsèque du cuir sont conservées.The mechanical operations of "sanding" to equalize the thickness are then eliminated and the qualities of intrinsic resistance of the leather are preserved.
De plus, une passe industrielle d'une tonne de peaux (100 douzaines) a permis de quantifier l'augmentation de surface. En effet une passe de référence mesure environ 8000 pied² (environ 743 m²). Une passe traitée à l'acide méthanesulfonique mesure environ 8400 pied² (environ 780 m²), soit une augmentation considérable de surface de 5 %.In addition, an industrial pass of one tonne of skins (100 dozen) made it possible to quantify the increase in surface area. Indeed, a reference pass measures approximately 8000 ft² (approximately 743 m²). A pass treated with methanesulfonic acid measures approximately 8,400 square feet (approximately 780 m²), a considerable increase in surface area of 5%.
Les quantités de produits ajoutés sont exprimées en pourcentage pondéral du poids des peaux picklées.The quantities of added products are expressed as a percentage by weight of the weight of the pickled skins.
2 peaux d'agneaux de pays (très bonne qualité) et 2 peaux de Nouvelle-Zélande (qualité moyenne) dégraissées et picklées (3600 g) sont placées dans 100 % de bain de saumure à 8° Baumé (88,24 g/l de NaCl), auquel on ajoute 2,5 % d'acide méthanesulfonique à 70 % en cinq fois en une heure (quantite d'ions CH₃ SO₃⁻ égale à 0,52 mole rapportée à 1 kg de peaux sèches).2 skins of local lambs (very good quality) and 2 skins of New Zealand (medium quality) degreased and pickled (3600 g) are placed in 100% brine bath at 8 ° Baumé (88.24 g / l of NaCl), to which 2.5% of 70% methanesulphonic acid is added in five times in one hour (quantity of CH₃ SO₃⁻ ions equal to 0.52 mole relative to 1 kg of dry skin).
On ajoute ensuite au bain 8 % de sulfate de chrome (basicité 33° teneur en chrome : 26 %) opération qui est suivie de l'addition après une heure, de 1 % de formiate de sodium puis de 4 % d'hydrogénocarbonate de sodium en quatre fois en trois heures ; le pH de fin de tannage est de 4,1. Toujours dans le bain de tannage, les peaux sont chauffées pendant une heure à 50° C.8% of chromium sulphate (basicity 33 ° chromium content: 26%) is then added to the bath, an operation which is followed by the addition after 1 hour, of 1% of sodium formate and then of 4% of sodium hydrogen carbonate. in four times in three hours; the end of tanning pH is 4.1. Still in the tanning bath, the skins are heated for one hour at 50 ° C.
Après 48 heures de repos, elles sont nourries, teintes et séchées. Les cuirs obtenus font l'objet d'une analyse visuelle : le colorant est uniformément réparti, de même que le chrome comme en témoigne une température ce rétraction supérieure à 100° C.After 48 hours of rest, they are fed, dyed and dried. The leathers obtained are subjected to a visual analysis: the dye is uniformly distributed, as is the chromium, as evidenced by a temperature of this retraction greater than 100 ° C.
Leurs qualités sont alors évaluées par un panel de professionnels : très bonne souplesse, beaucoup de plein et excellent toucher soyeux, légèrement cireux.Their qualities are then evaluated by a panel of professionals: very good flexibility, lots of fullness and excellent silky touch, slightly waxy.
Il est à noter qu'après traitement avec ce procédé, on ne fait quasiment plus la différence (souplesse, toucher) entre des peaux de qualités initiales très différentes, ce qui est un résultat remarquable et met en lumière l'intérêt considérable du procédé de l'invention pour traiter et valoriser des peaux bas de gamme.It should be noted that after treatment with this process, we almost no longer make the difference (flexibility, feel) between skins of very different initial qualities, which is a remarkable result and highlights the considerable interest of the the invention to treat and enhance low-end skin.
De plus quelles que soient les peaux, on observe une homogénéisation de leur épaisseur, donc un aplatissement du collet, partie la plus grasse, et une nette augmentation de leur superficie (par rapport à des peaux traitées de façon classique).In addition, whatever the skins, there is a homogenization of their thickness, therefore a flattening of the collar, the fattyest part, and a marked increase in their area (compared to skins treated in the conventional manner).
Les quantités de produits ajoutés sont données en pourcentage pondéral du poids des peaux tannées sèches.The quantities of products added are given as a percentage by weight of the weight of dry tanned hides.
A 2 peaux tannées nourries et séchées, placées dans 100 % d'eau à 55° C, sont additionnés 4 % de nourriture anionique-cationique.To 2 tanned skins fed and dried, placed in 100% of water at 55 ° C, are added 4% of anionic-cationic food.
Après une heure d'agitation, 6 % de colorant acide brun sont introduits. La fixation du colorant se fait, une heure plus tard, par acidification par 2 % d'acide formique et 2 % d'acide méthanesulfonique à 70 % en 2 fois en 2 heures (0,14 mole par kg de peaux tannées sèches).After one hour of stirring, 6% of brown acid dye are introduced. The dye is fixed, one hour later, by acidification with 2% formic acid and 2% methanesulfonic acid to 70% in 2 times in 2 hours (0.14 mole per kg of dry tanned hides).
Les peaux teintes sont alors mises au vent et séchées.The dyed skins are then put in the wind and dried.
L'évaluation de leurs qualités par un panel de professionnels donne les mêmes résultats que dans les exemples précédents : très bonne souplesse, excellent toucher, soyeux légèrement cireux. Un essai comparatif pratiqué en l'absence d'acide méthanesulfonique (4 % d'acide formique) conduit à des qualités de souplesse et toucher inférieures.The evaluation of their qualities by a panel of professionals gives the same results as in the previous examples: very good flexibility, excellent touch, silky slightly waxy. A comparative test carried out in the absence of methanesulfonic acid (4% formic acid) leads to lower flexibility and feel qualities.
Les quantités de produits ajoutés sont données en pourcentage pondéral du poids des peaux picklées.The quantities of added products are given as a percentage by weight of the weight of the pickled skins.
3 peaux (2000 g) d'agneaux dégraissées et picklées sont placées dans 200 % de bain de saumure à 8° Baumé (88,24 g/l de NaCl).3 skins (2000 g) of degreased and pickled lambs are placed in 200% brine bath at 8 ° Baumé (88.24 g / l NaCl).
Après dépicklage, (ajustement au pH à une valeur comprise entre 5,5 et 6), les peaux sont placées dans un bain d'eau (250 %) auquel sont additionnés 30 % d'extrait de québracho en 3 fois en 2 heures. Les peaux sont laissées dans le bain sous agitation pendant une nuit, puis rincées, blanchies et nourries.After depicklage (adjustment to pH to a value between 5.5 and 6), the skins are placed in a water bath (250%) to which are added 30% of quebracho extract in 3 times in 2 hours. The skins are left in the bath with stirring overnight, then rinsed, bleached and nourished.
Pour une peau le blanchiment et la nourriture sont effectués de façon classique : elle est placée dans un bain de 200 % d'eau à 50° C auquel on ajoute 1 % d'acide oxalique, puis 3 % de thiosulfate de sodium, et enfin 3 % de nourriture.For skin, bleaching and nourishment are carried out in the conventional way: it is placed in a bath of 200% water at 50 ° C. to which 1% of oxalic acid is added, then 3% of sodium thiosulfate, and finally 3% food.
Les deux autres peaux subissent le même traitement complété par l'addition de 1 % d'acide méthanesulfonique à 70 % en deux fois, après action de l'acide oxalique (0,21 mole d'ion CH₃ SO₃⁻ par kg de peaux sèches). Les trois peaux sèches ont une température de rétraction de 80-85° C, caractéristique d'un bon tannage végétal et sont, comme précédemment, soumises à l'appréciation de professionnels.The other two skins undergo the same treatment supplemented by the addition of 1% methanesulfonic acid to 70% in two batches, after the action of oxalic acid (0.21 mole of CH₃ SO₃⁻ ion per kg of dry skin ). The three dry skins have a shrink temperature of 80-85 ° C, characteristic of good vegetable tanning and are, as before, subject to the appreciation of professionals.
Les deux peaux traitées à l'acide méthanesulfonique présentent une plus grande souplesse et surtout un toucher particulièrement soyeux, par rapport à la peau traitée de façon classique.The two skins treated with methanesulfonic acid have greater flexibility and above all a particularly silky feel, compared to the skin treated in a conventional manner.
Des peaux d'agneaux en tripes sont picklées par l'acide méthanesulfonique selon l'exemple 2, tannées au chrome de façon traditionnelle, puis teintes avec fixation du colorant par l'acide méthanesulfonique selon l'exemple 4.Tripe lambskins are picked with methanesulfonic acid according to Example 2, chrome tanned in the traditional way, then dyed with fixing of the dye by methanesulfonic acid according to Example 4.
Le panel de professionnels consulté a jugé ces peaux comme étant encore plus souples et comme ayant un toucher encore plus soyeux que les peaux traitées à l'acide méthanesulfonique lors d'une seule étape (picklage ou teinture).The panel of professionals consulted judged these skins to be even more flexible and to have an even more silky feel than skins treated with methanesulfonic acid during a single step (pickling or dyeing).
De même que dans l'exemple 2, on mesure une augmentation de surface de l'ordre de 5 %, accompagnée d'une homogénéisation du taux de matières grasses et donc de l'épaisseur.As in Example 2, an increase in surface area of the order of 5% is measured, accompanied by a homogenization of the fat content and therefore of the thickness.
Les quantités de produits ajoutés sont exprimées en pourcentage pondéral par rapport au poids des peaux picklées.The quantities of products added are expressed as a percentage by weight relative to the weight of the pickled skins.
Deux peaux (1000 g) d'agneaux dégraissées et picklées sont placées dans 400 % de bain de saumure à 8° Baumé (soit 88,24 g/l de NaCl) pendant une heure ; par essorage), l'humidité des peaux est ramenée à 200 % d'eau par rapport au poids sec.Two skins (1000 g) of degreased and pickled lambs are placed in 400% brine bath at 8 ° Baumé (ie 88.24 g / l NaCl) for one hour; by spinning), the humidity of the skins is reduced to 200% of water relative to the dry weight.
Ces peaux sont alors placées dans un bain de 250 % de trichloro-1,1,2 trifluoro-1,2,2 éthane auquel on additionne 308 ml de la solution de méthanesulfonate de chrome décrite dans l'exemple 1 (soit 10,8 g Cr) (quantité d'ions CH₃ SO₃⁻ égale à 1,78 mole rapportée à 1 kg de peaux sèches ; quantité globale d'eau égale à 3000 g rapportée à 1 kg de peaux sèches).These skins are then placed in a bath of 250% trichloro-1,1,2 trifluoro-1,2,2 ethane to which 308 ml of the chromium methanesulfonate solution described in Example 1 are added (i.e. 10.8 g Cr) (amount of CH₃ SO₃⁻ ions equal to 1.78 mole relative to 1 kg of dry skin; overall amount of water equal to 3000 g relative to 1 kg of dry skin).
Après une heure d'agitation on basifie progressivement en ajoutant successivement 1 % de formiate de sodium, 4 % de phtalate de sodium et 3,5 % d'hydrogénocarbonate de sodium en petites fractions sur 8 heures. Le pH de fin de tannage est de 4,3.After one hour of stirring, it is gradually basified by successively adding 1% sodium formate, 4% sodium phthalate and 3.5% sodium hydrogencarbonate in small fractions over 8 hours. The end of tanning pH is 4.3.
Il est à souligner que la teneur en chrome du bain résiduaire est nulle.It should be emphasized that the chromium content of the residual bath is zero.
Après 48 heures de repos, les peaux sont nourries et séchées de façon traditionnelle.After 48 hours of rest, the skins are nourished and dried in the traditional way.
Les peaux tannées sèches font l'objet d'une analyse visuelle : le chrome est uniformément réparti et fixé ; les peaux ont une température de rétraction supérieure à 100° C, caractéristique d'un bon tannage.Dry tanned hides are subjected to a visual analysis: the chromium is uniformly distributed and fixed; the hides have a shrinking temperature above 100 ° C, characteristic of good tanning.
Elles sont ensuite appréciées par un panel de professionnels qui a souligné une fois de plus leur grande souplesse et leur très bon toucher soyeux.They are then appreciated by a panel of professionals who once again emphasized their great flexibility and their very good silky touch.
Claims (10)
- Process for treating tawing or tannery products comprising collagenic tissues such as hides and leathers in order to bring about an effect of tissue- fibre relaxation and internal distribution of fats leading to an increase in the surface of the hides and to homogenisation of their thickness, characterised in that the hides or leathers are brought into contact with methanesulfonic acid CH₃SO₃H or methanesulfonate ion CH₃SO₃⁻ in acid medium, in a quantity of at least 0.05 mol per kg of dry hides or dry leathers.
- Process according to Claim 1, characterised in that the hides or leathers are brought into contact with methanesulfonic acid in aqueous medium or a mixed medium consisting of water and organic solvent.
- Process according to Claim 2 for the production of leathers from raw hides, in which, in the course of the production cycle, the raw hides are subjected to a pickling operation, characterised in that the operation of bringing the hides into contact with the methanesulfonic acid is effected in the course of pickling, use being made, by way of pickling agent, of said methanesulfonic acid, possibly in combination with a different acid.
- Process according to one of Claims 1 or 2 for the production of leathers from hides, in which, in the course of the production cycle, the hides are subjected to a tanning operation, characterised in that the operation of bringing the hides into contact with the methanesulfonic acid or methanesulfonate ions is combined with the tanning operation by introducing said ions into the tanning bath.
- Process according to Claim 4 for the production of leathers, characterised in that use is made of a tanning bath containing a mixture of at least one mineral, vegetable and/or synthetic tanning agent on the one hand, and methanesulfonic acid or a salt of this acid on the other hand.
- Process according to Claim 4 for the production of leathers, characterised in that use is made of an aqueous or mixed tanning bath containing chromium methanesulfonate.
- Process according to Claim 6 for the production of leathers, characterised in that the chromium methanesulfonate admixed to the bath is prepared by causing the methanesulfonic acid to react upon a barium salt, whereupon the barium methanesulfonate obtained is caused to react with chromium sulfate and the precipitate is eliminated by filtration or centrifuging in order to isolate the chromium methanesulfonate present in solution.
- Process according to one of Claims 1 or 2 for the production of leathers from tanned hides, in which, in the course of the production cycle, the tanned hides are subjected to a dyeing operation in the course of which they are brought into contact with a dye having a pH-value close to neutral, whereupon said dye is fixed at a lower pH-value, characterised in that said hides are brought into contact with the methanesulfonic acid in the course of the dyeing operation, use being made of methanesulfonic acid, possibly in combination with a different acid, in order to lower the pH-value.
- Process according to Claims 3, 4 and 8 jointly for the production of leathers, characterised in that the hides are brought into contact with the methanesulfonic acid on at least three occasions: during pickling, during tanning in the tanning bath and during the dyeing operation.
- Process according to one of Claims 3 to 9 for the production of leathers, characterised in that the hides are brought into contact with methanesulfonic acid in such a way that the total quantity of said acid amounts to between 0.1 and 2.0 mol per kg of dry hides.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9016520 | 1990-12-19 | ||
| FR9016520A FR2670800B1 (en) | 1990-12-19 | 1990-12-19 | PROCESS FOR THE TREATMENT OF SKINS OR LEATHERS, TANNING AGENTS AND METHOD OF MANUFACTURE. |
| PCT/FR1991/000979 WO1992011391A1 (en) | 1990-12-19 | 1991-12-06 | Method for processing hides or leather, tanning agents and method for manufacturing same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0563139A1 EP0563139A1 (en) | 1993-10-06 |
| EP0563139B1 true EP0563139B1 (en) | 1995-03-01 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP92901323A Expired - Lifetime EP0563139B1 (en) | 1990-12-19 | 1991-12-06 | Method for processing hides or leather based on methanesulphonate ions. |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0563139B1 (en) |
| CN (1) | CN1063312A (en) |
| AR (1) | AR248051A1 (en) |
| AU (1) | AU9112491A (en) |
| ES (1) | ES2069988T3 (en) |
| FR (1) | FR2670800B1 (en) |
| MA (1) | MA22365A1 (en) |
| PT (1) | PT99843A (en) |
| WO (1) | WO1992011391A1 (en) |
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| EP2607499A3 (en) * | 2013-02-14 | 2013-07-10 | Basf Se | Method for producing leather |
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| US7320793B2 (en) | 2001-01-19 | 2008-01-22 | Cytos Biotechnology Ag | Molecular antigen array |
| KR100556504B1 (en) * | 2002-12-18 | 2006-03-03 | 엘지전자 주식회사 | safety device of electric oven range |
| US10280474B2 (en) * | 2015-07-13 | 2019-05-07 | Council Of Scientific & Industrial Research | Dispersing agent composition for tanning of hides/skins and process for the preparation thereof |
| ES2927983T3 (en) * | 2016-06-14 | 2022-11-14 | Basf Se | A process for producing leather |
| CN106755647B (en) * | 2017-03-16 | 2018-10-30 | 林建武 | A kind of leather manufacture cladding immersion liquid medicine preparation facilities |
| CN114540558A (en) * | 2021-12-14 | 2022-05-27 | 浙江中辉裘革科技有限公司 | Method for removing free formaldehyde from fur by combined capturing, eluting and fixing |
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|---|---|---|---|---|
| IT1002971B (en) * | 1973-11-07 | 1976-05-20 | Schill And Seilacher | PROCEDURE FOR THE PRODUCTION AND USE OF A GREASING CHROME TANNING SUBSTANCE |
| SU1057544A1 (en) * | 1982-07-28 | 1983-11-30 | Джамбулский технологический институт легкой и пищевой промышленности | Method for treating ship blosse |
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- 1990-12-19 FR FR9016520A patent/FR2670800B1/en not_active Expired - Fee Related
-
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- 1991-12-06 ES ES92901323T patent/ES2069988T3/en not_active Expired - Lifetime
- 1991-12-06 WO PCT/FR1991/000979 patent/WO1992011391A1/en active IP Right Grant
- 1991-12-06 AU AU91124/91A patent/AU9112491A/en not_active Abandoned
- 1991-12-06 EP EP92901323A patent/EP0563139B1/en not_active Expired - Lifetime
- 1991-12-10 AR AR32134791A patent/AR248051A1/en active
- 1991-12-16 MA MA22649A patent/MA22365A1/en unknown
- 1991-12-18 PT PT9984391A patent/PT99843A/en not_active Application Discontinuation
- 1991-12-19 CN CN 91112763 patent/CN1063312A/en active Pending
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| R.C. PAUL et al, Indian J. Chem. (12), 825-6 (1974) * |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2607499A3 (en) * | 2013-02-14 | 2013-07-10 | Basf Se | Method for producing leather |
| WO2014124951A1 (en) * | 2013-02-14 | 2014-08-21 | Basf Se | Method for producing leather |
| KR20150119203A (en) * | 2013-02-14 | 2015-10-23 | 바스프 에스이 | Method for producing leather |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0563139A1 (en) | 1993-10-06 |
| PT99843A (en) | 1992-12-31 |
| AU9112491A (en) | 1992-07-22 |
| WO1992011391A1 (en) | 1992-07-09 |
| FR2670800B1 (en) | 1994-05-20 |
| ES2069988T3 (en) | 1995-05-16 |
| FR2670800A1 (en) | 1992-06-26 |
| CN1063312A (en) | 1992-08-05 |
| MA22365A1 (en) | 1992-07-01 |
| AR248051A1 (en) | 1995-05-31 |
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