Classifications

• • 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
  • D06P3/3206—Material containing basic nitrogen containing amide groups leather skins using acid dyes
• • 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
• • 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
  • C14C9/00—Impregnating leather for preserving, waterproofing, making resistant to heat or similar purposes
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06L—DRY-CLEANING, WASHING OR BLEACHING FIBRES, FILAMENTS, THREADS, YARNS, FABRICS, FEATHERS OR MADE-UP FIBROUS GOODS; BLEACHING LEATHER OR FURS
  • D06L1/00—Dry-cleaning or washing fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M23/00—Treatment of fibres, threads, yarns, fabrics or fibrous goods made from such materials, characterised by the process
  • D06M23/10—Processes in which the treating agent is dissolved or dispersed in organic solvents; Processes for the recovery of organic solvents thereof
  • D06M23/105—Processes in which the solvent is in a supercritical state
• • 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
  • D06P1/52—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 synthetic macromolecular substances
  • D06P1/5264—Macromolecular compounds obtained otherwise than by reactions involving only unsaturated carbon-to-carbon bonds
  • D06P1/5292—Macromolecular compounds obtained otherwise than by reactions involving only unsaturated carbon-to-carbon bonds containing Si-atoms
• • 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
  • D06P1/64—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 without sulfate or sulfonate groups
  • D06P1/642—Compounds containing nitrogen
  • D06P1/647—Nitrogen-containing carboxylic acids or their salts
• • 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
  • D06P1/673—Inorganic compounds
  • D06P1/67333—Salts or hydroxides
  • D06P1/67341—Salts or hydroxides of elements different from the alkaline or alkaline-earth metals or with anions containing those elements
• • 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
  • D06P1/673—Inorganic compounds
  • D06P1/67333—Salts or hydroxides
  • D06P1/6735—Salts or hydroxides of alkaline or alkaline-earth metals with anions different from those provided for in D06P1/67341
  • D06P1/67366—Phosphates or polyphosphates
• • 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
  • D06P1/94—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 dyes dissolved in solvents which are in the supercritical state
• • 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
  • D06P3/3206—Material containing basic nitrogen containing amide groups leather skins using acid dyes
  • D06P3/3213—Material containing basic nitrogen containing amide groups leather skins using acid dyes monoazo
• • 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
  • D06P3/3206—Material containing basic nitrogen containing amide groups leather skins using acid dyes
  • D06P3/3213—Material containing basic nitrogen containing amide groups leather skins using acid dyes monoazo
  • D06P3/322—Material containing basic nitrogen containing amide groups leather skins using acid dyes monoazo using monoazo premetallised dyes
• • 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
  • D06P3/3206—Material containing basic nitrogen containing amide groups leather skins using acid dyes
  • D06P3/3226—Material containing basic nitrogen containing amide groups leather skins using acid dyes dis-polyazo
• • 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
  • D06P3/3206—Material containing basic nitrogen containing amide groups leather skins using acid dyes
  • D06P3/3226—Material containing basic nitrogen containing amide groups leather skins using acid dyes dis-polyazo
  • D06P3/3233—Material containing basic nitrogen containing amide groups leather skins using acid dyes dis-polyazo using dis-polyazo premetallised dyes
• • 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
  • D06P3/34—Material containing ester groups
  • D06P3/343—Material containing ester groups using vat or sulfur dyes

Definitions

• the subject of the present invention is a method of treating skins, leather or collagen-containing sheet materials, at different stages of the transformation of skins into leathers, and at different stages of finishing these products.
• the different stages of transformation of skins into leather are in particular the degreasing which consists in removing part of the fats from the skin to facilitate its transformation into leather, and the tanning which transforms the raw putrescible skin into resistant and rot-proof leather; this last operation is considered to be the most important in the chain of transformation of skins into cu rs.
• the different stages of finishing can be retanning, which is an operation to reinforce the mechanical strength of the cui rs, dyeing and water repellency for waterproofing.
• the quantity of mainly aqueous effluents currently discharged by the leather industry around the world is around 400 to 500 million m ⁇ per year, or nearly 40 million equivalent "daily resident".
• the present invention specifically relates to a method of treating skins, leather or collapsible materials containing collagen, which avoids the use of harmful solvents, detrimental to the environment, and limit in a way significant volumes of effluent produced during these treatments.
• the process of the invention applies in particular to the degreasing and tanning of hides and to the finishing treatments (retanning, strengthening of the structure, dyeing and water repellency) of hides, leathers and other sheet materials containing collagen.
• the subject of the invention is a method of degreasing the skins with a view to their transformation into leathers, which comprises the following steps:
• step a) of this process the dense fluid is circulated continuously at the pressure Pi and at the temperature Ti in a treatment enclosure containing the skins, the dense fluid is purified at the outlet of the treatment chamber to separate from it the dissolved fat and the dense purified fluid is recycled at the entrance to the enclosure.
• the dense fluid can be purified by varying its pressure and / or its temperature in order to eliminate the dissolved products in liquid form. To recycle the dense fluid, it is then necessary to bring it back under the conditions of pressure Pi and temperature Ti chosen.
• step b the circulation of the dense fluid under pressure is interrupted and the enclosure is brought back to atmospheric pressure.
• the dense fluid under pressure is used as a solvent to extract the fats of a lipidic nature, but the operation is carried out in such a way that the extraction of the fats is not total in order to keep the skin looking supple.
• the method of the invention therefore makes it possible to carry out the degreasing of the skins in good conditions.
• the invention also relates to a process for treating products consisting of skins, leathers or sheet materials. containing co L agene with a view to their transformation into cui rs or their finishing which comprises the following stages a) bringing the skins, cui rs or sheet materials into contact with a dense fluid containing at least one active substance for the transformation or the finishing of skins, leathers or sheet materials, under a pressure Pi at least equal to the critical pressure Pc of the fluid and at a temperature Ti such that the fluid has a sufficient density to impregnate the skins, leathers or sheet materials of the active substance (s), and b) bring the skins, leathers or sheet materials to atmospheric pressure to remove the dense fluid in the form of gas .
• step a) is carried out ably, by continuously circulating the dense fluid containing the active substance (s) at the pressure Pi and at the temperature Ti in a treatment chamber. containing the skins, leathers or sheet materials, treating the dense fluid at the outlet of the treatment chamber to readjust its content of active substance (s) to the desired value, and recycling the fluid dense thus treated in the treatment enclosure.
• the treatment of the dense fluid leaving the enclosure with a view to readjusting its content of active substance (s) to the desired value can be carried out in gas-liquid or li contactors which, for example, counter-current exchange columns.
• Step b) can be carried out as previously by interrupting the circulation of the fluid dense in the enclosure and reducing it to atmospheric pressure.
• step a) of impregnation with the active substance and / or before step b) decompression it may be advantageous to rinse the products treated in the enclosure with pure dense fluid, before performing step a) of impregnation with the active substance and / or before step b) decompression.
• step a) can be carried out statically (soaking) or dynamically, that is to say with continuous circulation of the dense fluid containing the active substance.
• the expression “dense fluid” means a fluid under a pressure P greater than the critical pressure Pc of this fluid, which is preferably under temperature conditions Ti close to the critical temperature Te of the fluid, this temperature and this pressure being chosen to give the fluid either a high extraction power with respect to grease, or a high dissolution or transport power with respect to the active substance or substances used.
• the dense fluid used is in the form of gas at pressure and at room temperature.
• This dense fluid can be chosen, for example, from carbon dioxide, sulfur hexafluoride, nitrous oxide, ammonia and light alkanes, having for example from 2 to 5 carbon atoms.
• carbon dioxide is used because it is non-toxic, non-flammable, not very reactive and inexpensive.
• the ⁇ ense fluid can be in the subcritical or supercritical state.
• subcritical fluid is meant a fluid at a temperature T lower than the critical temperature Te of the fluid, which in the process of the invention corresponds to the liquid state, since the pressure Pi of the fluid is always greater than the pressure critic Pc.
• supercritical fluid is meant a fluid whose temperature T is higher than the critical temperature, which, in the process of the invention, corresponds to the supercritical state since the pressure Pi of the fluid is always greater than the critical pressure .
• FIG. 1 the state diagram (in dashed lines) of pressure (in MPa) - temperature (in ° C.) of carbon dioxide CO2 is shown.
• the critical point C of CO2 corresponds to a critical temperature Te of 31 ° C and a critical pressure Pc of 7.3 MPa.
• the supercritical fluid in the supercritical state according to the invention corresponds to the hatched area A.
• the subcritical fluid in the liquid state in accordance with the invention corresponds to the hatched zone 3.
• the density of the fluid can be adjusted and therefore its solvent power vis-à-vis the fats to be dissolved or its capacity for dissolution and transportability of substances. active ingredients used, further optimizing its dissolution capacity so that it does not adversely affect the products to be treated.
• the densities obtained under pressure are around 1 kg / cm 3 for the liquid state and adjustable from 0.2 to 1 kg / cm 3 for the supercritical state, ie a solvent power. equivalent to that of traditional liquid solvents for the densest states; moreover, the fact that this solvent power is adjustable by pressure and / or temperature, can be judiciously used in purification and i pregnation operations with the active substance (s), during recycling of dense fluid.
• a dense fluid is used in the supercritical state.
• the dense fluid also has viscosities ten times lower and diffusion coeffi ⁇ cients 10 to 100 times greater than in the liquid state, which is an important advantage for the kinetics of extraction and for impregnation operations.
• the pressure Pi can be chosen, for example in the range from 6 to 50 MPa, and the temperature Ti can be, for example from 10 to 300 ° C.
• the pressure variation ⁇ P can represent around 10% of Pi, for example over a period of 5 to 50 s.
• the active substances used are S
• these active substances are organic materials or organo-mineral complexes, and the dense fluid used is also chosen according to the active substance so as to dissolve this substance or to be able to ensure its transport on the products to be treated in the pregnant.
• the active substance is advantageously chosen from tanning agents, reinforcing agents, coloring agents, water-repellent agents and the precursors of these agents.
• the tanning or reinforcing agents may be aldehyde compounds such as formalin and g lutara Idehyde; condensation products of the acry late-di i socyanate, methyl lol-urea, or methylol-melamine type, of the licked oligomer type or of the precursors of these products, for example polyethylene glycols (PEG) and polytetraethylene glycols (PTEG) or methylene glycols (PTMG) modified in the case of licked oligomers; phenol, naphthol, naphthalene or dihydroxyphenylsulfone products; vegetable tannins for example based on pyrogallic or catechism, or their precursors, tannins of chromium, of aluminum, of zirconium, titanium and iron.
• aldehyde compounds such as formalin and g lutara Idehyde
• nitrated and nitrosated compounds such as mono and polyazo dyes and with metal complexes; sti lbene derivatives; diphenyl and t ri pheny imethane derivatives; oxazine, azine and azine compounds; pyridine, quinoline and acridine; phthalocyanic compounds; anth raqui noni c compounds, sulfur dyes; and their precursors.
• water-repellent agents that can be used in the invention, mention may be made of chromium and fluorinated fatty acid complexes, chromium and aluminum phosphate aky, derivatives of imacidic acid, phosphoric acid esters, poly loxane resins, fluorinated carbon compounds or their precursors.
• the dense fluid can further comprise an additive to modify the solvent or dehydrating power of the dense fluid, or to facilitate the dissolution or the transport of the active substance (s) in the dense fluid.
• the active substance when it is not directly soluble in the dense fluid used, it can be dissolved in an additive playing the role of auxiliary solvent, the whole being soluble or transported in the dense fluid.
• the additive used can also be water, which makes it possible to modulate the drying power of the dense fluid. This possibility of regulating the water content of the products treated by modulating the drying power of the dense fluid constitutes a significant improvement in the chain of transformation of skins into leathers.
• the active substance (s) can be included in the treated products, either by capillary action or direct absorption in these products when they have a particular affinity for this active substance, either by reaction of the active substance with compounds of the treated product, or by means of an appropriate treatment which transforms the active substance into a form retained by the product to be treated.
• the active substance can consist of a precursor of a tanning, reinforcing, coloring or water repellency agent. Treatments capable of modifying the active substance so that it is retained in
• the treated product can consist of a chemical, physicochemical, photochemical treatment, an irradiation, or even a thermal treatment. These treatments can be carried out during or after the operation of bringing the products into contact with the dense fluid.
• the process of the invention is very interesting for the treatment of skins, skins, and other sheet products containing collagen, since it can be implemented at different stages of the processing and finishing chain. these products.
• pressure and temperature conditions adapted to the treatment carried out are used in each stage, and these conditions may be the same or different when passing from from one stage of treatment to another.
• the same dense fluid can be used in all stages or different dense fluids.
• FIG. 1 already described, represents (in phantom lines) the CO2 state diagram and (in solid lines) The lines of CO isoassse volume, and
• FIG. 2 shows a processing installation for implementing the inventive method.
• the installation comprises a treatment enclosure ( 1 ) in which the products (2 ) to be treated can be placed, such as skins, leathers or sheet products containing collagen, on a suitable support to promote the flow of dense fluid in products.
• a treatment enclosure ( 1 ) in which the products (2 ) to be treated can be placed, such as skins, leathers or sheet products containing collagen, on a suitable support to promote the flow of dense fluid in products.
• the dense fluid is introduced into the enclosure (1) by an inlet pipe (3) coming from a storage container (4) after having been brought to the pressure Pi desired by the compressor (5) and to the temperature Ti required by the heat exchanger (7).
• This dense fluid was optionally charged with active substance (s ) and / or additive (s) in contactors such as contactors (9) and (11).
• the contactor (9) in which circulates for example water or an additive such as an alcohol through the lines (13) and (15), can be connected by the line (17) to the inlet pipe (3 ) dense fluid in the enclosure (1).
• the dense fluid introduced by the pipe (17) is evacuated by the pipe (19) then recycled in the inlet pipe (3), either by the pipe (21), or by the pipe ( 23).
• the lines 17, 19, 21 and 23 and the pipe (3) are provided with suitable valves, not shown in the drawing, to allow the dense fluid to follow the desired circuit before entering the enclosure (1).
• the contactor (11) which is parcou ⁇ ru for example by an active substance introduced by a pipe (25) and evacuated by a pipe (27), can be connected to the inlet pipe (3) by a pipe (29).
• the dense fluid loaded with active substance leaving the contactor (11) via the pipe (31) is then recycled into the inlet pipe (3) through the pipe (23).
• the dense fluid which is discharged into the outlet pipe (33) can be recycled without pressure loss other than the pressure losses, at the inlet of the enclosure (1) by line (34), circulator (35), heat exchanger (7) and possibly Contactors (9) and (11 ) .
• the dense fluid is preferably recycled in the enclosure after having purified it from the dissolved products that it contains.
• the dense fluid leaving via the pipe (33) is expanded in the valve (37), then introduced into the enclosure (39) for recovering the dissolved products which are separated from the dense fluid and discharged through the pipe. (41). After this separation, the dense fluid which is in the gaseous state is brought back to the temperature suitable for recycling by the exchanger (43) and conveyed in the storage container (4) to be recycled in the enclosure (1) to the temperature and pressure you want to read.
• a degreasing treatment In the case of a degreasing treatment,
• the contactors 9 and 11 are not connected to the supply pipe (3).
• the contactor (9) can be replaced by a contactor (40) supplied with additive by the lines (42) and (44), which is placed on the dense fluid recycling circuit.
• an additive for example water, can be added in small quantities to the fluid, when it is in the gaseous state after expansion in the valve 37.
• the compressor (5) is stopped and the dense fluid leaving the enclosure (1) is decompressed by the expansion valve (37) in order to evacuate it in gaseous form as previously in the storage container. (4) and bring the treated products to atmospheric pressure.
• the installation can be supplied with treatment fluid through the pipe (45) and drained through the pipe (47).
• Example 1 Degreasing of sheep skin in the pi ck lé state.
• the lipid and water content of the treated skins is determined. We aknowledge as well as the lipid content decreased by 40% and that the water content decreased by 17%.
• Example 2 Degreasing of skins in the White Stabilized Wet state (BSH).
• the lipid and water content of the skins is determined. It is found that the lipid content has decreased by 26% and that the water content has decreased by 21%.
• the skins retain a beautiful supple appearance with a very slight deposit of mineral salts.
• the skins treated in examples 1 and 2 were transformed into finished leather and were compared to skins which had undergone the same treatments but for which the degreasing had been carried out in a conventional fashion in tanning by using white spirit associated with an emulsifying agent consisting of a base alkyl-oxyethylenated.
• the skins degreased according to the conventional route or according to the route of Examples 1 and 2 were tanned with chromium salt (10% basic sulphate at 33% basicity), then wrung, put in the thickness by stripping ; they were then retanned, dyed and fed under the same conditions. During these operations, all the skins were treated in the same material in a single batch.
• Examples 3 to 6 Impregnation of hides and skins.
• the method of the invention is used to impregnate skins and leather by using, as active substance, reinforcing agents constituted by telechelic oligomers of the polyethylene glycol (PEG) type having molecular weights in the range from 200 to 1500.
• PEG polyethylene glycol
• the use of these oligomers is interesting because they are liquid products which can be dissolved in a dense fluid under pressure unlike the high solid polymers generally used for the reinforcement of leather products.
• the conditions of pressure Pi and temperature Ti are chosen to have good solubility of the active substance ( PEG) in the dense fluid consisting of carbon dioxide.
• the impregnation of skins and leathers is carried out under satisfactory conditions to obtain their reinforcement by passing 300 kg of dense fluid loaded with oligomer per kg of treated products.
• Examples 7 to 9 Impregnation of hides and skins.
• Example 10 illustrates the impregnation of an active substance constituted by a nourishing principle in skins and leathers.
• Example 10 In this example, skins and hides are treated using as nourishing product an oil of animal origin sulfitated at 60% content of active materials marketed under the name Lipoderm-Licker PK.
• carbon dioxide is introduced into the treatment enclosure containing the skins and leathers as well as the oil, at a pressure of 25 MPa, at a temperature of 40 ° C. and the operation is carried out under static conditions for 16 hours. .
• the skins and leathers are then brought to atmospheric pressure and their fat content is determined.
• Skins and hides are treated using as active substance the same nourishing product as in Example 10, but in this case performing the impregnation under dynamic conditions as follows.
• Carbon dioxide is passed under a pressure of 25 MPa, at a temperature of 40 ° C, with a flow rate of 15 kg / h in a first autoclave comprising the oil and then in the treatment chamber containing the hides and skins , for 4 hours.
• Example 12 After this treatment, the fat content of the hides and skins is determined. The results obtained are given in Table 2. In view of these results, it is noted that despite the fluxes of CO2 and greater in oil than in Example 10, the fat content is substantially the same.
• Example 12
• Skins and hides are treated using the same active substance as in Examples 10 and 11, operating a dynamic regime as in Example 11, but performing the following 2 steps under the same pressure conditions (25 MPa) , temperature (40 ° C) and CO2 flow rate (15 kg / h): 1) prior treatment with pure CO2 of hides and skins for 5 h, and
• the variation in humidity of the leathers can be limited by humidifying the CO2 beforehand. Water can however modify the impregnation mechanisms and can therefore have a positive as well as a negative aspect.

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• Engineering & Computer Science (AREA)
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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Dispersion Chemistry (AREA)
• Treatment And Processing Of Natural Fur Or Leather (AREA)
• Synthetic Leather, Interior Materials Or Flexible Sheet Materials (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

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• 1992
  • 1992-10-02 FR FR9211703A patent/FR2696477B1/fr not_active Expired - Fee Related
• 1993
  • 1993-10-01 AT AT93921975T patent/ATE154397T1/de active
  • 1993-10-01 US US08/244,206 patent/US5512058A/en not_active Expired - Fee Related
  • 1993-10-01 EP EP93921975A patent/EP0615550B1/de not_active Expired - Lifetime
  • 1993-10-01 DE DE69311532T patent/DE69311532D1/de not_active Expired - Lifetime
  • 1993-10-01 CA CA002124354A patent/CA2124354A1/fr not_active Abandoned
  • 1993-10-01 WO PCT/FR1993/000960 patent/WO1994008054A1/fr active IP Right Grant
  • 1993-10-01 ES ES93921975T patent/ES2105323T3/es not_active Expired - Lifetime
• 1997
  • 1997-08-27 GR GR970402195T patent/GR3024556T3/el unknown

Non-Patent Citations (1)

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