EP0324734A1 - Procede pour la production de cuir destine a la confection de tiges de chaussures et produit obtenu. - Google Patents

Procede pour la production de cuir destine a la confection de tiges de chaussures et produit obtenu.

Info

Publication number
EP0324734A1
EP0324734A1 EP87902692A EP87902692A EP0324734A1 EP 0324734 A1 EP0324734 A1 EP 0324734A1 EP 87902692 A EP87902692 A EP 87902692A EP 87902692 A EP87902692 A EP 87902692A EP 0324734 A1 EP0324734 A1 EP 0324734A1
Authority
EP
European Patent Office
Prior art keywords
resin
bath
skins
acrylic ester
skin
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.)
Granted
Application number
EP87902692A
Other languages
German (de)
English (en)
Other versions
EP0324734B1 (fr
Inventor
Antonio Luciani
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to AT87902692T priority Critical patent/ATE62277T1/de
Publication of EP0324734A1 publication Critical patent/EP0324734A1/fr
Application granted granted Critical
Publication of EP0324734B1 publication Critical patent/EP0324734B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

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
    • C14C11/00—Surface finishing of leather
    • 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

Definitions

  • the present invention relates to a process for the production of leather intended for making uppers of footwears as well as to the prod ⁇ ucts thereof. More particularly, the present invention relates to a proc ⁇ ess for treating wool-bearing sheep skins in order to obtain punctured or pierced leather having the compactness and strength features which are needed to employ the same for making footwear uppers having wool on their inner surface, said uppers being intended for footwears to be worn during the spring-summer period-
  • Such process distinguishes with respect to the traditional opera ⁇ tions performed on wool-bearing sheep skins by the operations of treat ⁇ ing said skins with acrylic resins of various compositions, respective ⁇ ly after the retanning and the puncturing steps.
  • Footwears are known at the present time which are suitable for hot months, more particularly for summertime, and employ pierced or punctured uppers obtained from calfskin and unlined on their inside, which uppers have the compactness and strength features required for that specific em ⁇ ployment.
  • the present invention suggests the employment, as the raw material for making uppers of summer foot ⁇ wears of punctured or pierced hides obtained from wool-bearing sheep skins, which are capable because of the presence of a wool layer on their inside surface to form a coating that is suitable because of its very nature to keep a constant inner temperature as well as to assure the circulation of air so avoiding overheating of feet and hence the sweating of the same, and, because of its intrinsic antistatic charac ⁇ ter, to reduce the introduction of dust.
  • the leather sugge ⁇ sted according to the present invention has the characteristic property of giving rise to no compression areas localized at any part of the foot so that a uniform comfort is assured and the leather in question final ⁇ ly shows advantageously suitable as a stimulator of the peripheral cir ⁇ culation of blood and useful as an agent capable of absorbing the elec ⁇ trostatic energy built up in the body.
  • the present invention suggests to per ⁇ form acrylic resin treatment operations at the end of the retanning step and after the puncturing or piercing step.
  • the double object is obtained of: a) giving the skins a higher compactness and strength so that,the skin can be next punctured or pierced with no risks of tearing the same and the upper can be made by adapting the same to the desired model; b) increasing the strength of the skin at the points corresponding to the inner surfaces of the holes so as to avoid the dilation of the same and the tearing of the skin as much as possible at the points cor ⁇ responding to said surfaces during wear.
  • the basis operations of the process according to the present invention consist in the application and the successive polymerization, in two successive steps, of acrylic resins inside the fibrous texture of the skin and at points corresponding to the inner surfaces of the holes or punctures during a tanning treatment with retanning and finishing according to the procedure of the traditional type.
  • Substantially such operations are carried out in the final part of the retanning operation and after the puncturing or piercing operation.
  • the traditional flowsheet of treatment of the skins normally provides different steps of working in a bath as well as different steps of dry working.
  • the dry working of the traditional type is based on the contra ⁇ ry on the operational steps of finishing, puncturing or piercing and the successive finishing.
  • the second operation which is characteristic of the process ac ⁇ cording to the present invention is performed during the dry working, after the piercing or puncturing step and it consists in treating the exposed surface of the hide, inside the holes, with an acrylic type resin which is made up of a mixture of an acrylic acid and an acrylic ester in order to increase the surface strength of the hide at the points corresponding to the inner walls of the holes, so as to avoid as much as possible the risk of dilating and tearing the hide during employment.
  • a process for the production of leather intended for making uppers of footwears to be worn during the spring-summer period said process being characterized in that after the bath working of the sheep skins, said working comprising the steps of soaking, fleshing, washing, pick- ling, tanning, acid removal and retanning, skins are treated with an acrylic ester based resin in water solution, which resin is caused to polymerize so that the original fiber lattice becomes thicker and, during the dry working which consists in a first finishing step, a step in which skins are pierced or punctured, and a second finishing step, a further treatment is carried out with a resin base on acrylic acid and an acrylic ester in a water solution, which resin is poly ⁇ merized at the points corresponding to the inner surfaces of the holes.
  • the melamine and the ureic resins also have to be excluded because of the same reason, though such resins show the advantage of giving the hides quite good properties of feel and softness.
  • the resins of the dicyandiamide type that on the contrary could give the desired properties of strength, are unsuitable to satisfy the objects of the present invention as they spoil at a remarkable extent the characteristics of the chrome tanning step and, above all the adapta ⁇ bility of the hides to the dyeing step.
  • the acrylic ester polymeric compound is added to a neutralization bath consisting of water at 50°C and of an acid removal agent (for instance the CORA- TIL ND mentioned above), in which bath the hides have been dipped and adjusted to a pH of about 6.
  • a neutralization bath consisting of water at 50°C and of an acid removal agent (for instance the CORA- TIL ND mentioned above), in which bath the hides have been dipped and adjusted to a pH of about 6.
  • the acrylic ester resin is added preferably to the neutralization bath after about 1 hour, after the neutralization has occurred com ⁇ pletely, at the concentration of 7 g/1, in order to give the possibil- ility of penetration into the hide fibers at a larger extent at the points where the hide itself is less strong and, more precisely, in the side parts where the structure is less relaxed and the fibers are longer.
  • the acrylic ester resin after a period ranging from 30 minutes to 2 hours, when the resin it ⁇ self has completely gone into the hide, is caused to polymerze first with a slight addition of formic acid, so that the resin becomes bound to the fibers of the hide, and next it is caused to polymerize a second time in the dry state direct on the hides which now are completely dry,
  • the treatment with a resin of acrylic acid and an acrylic ester is carried out according to the procedure disclosed above.
  • said treatment is performed by dipping the pierced hide into a water bath at 50-60°C in which a prepolymerized resin of acrylic acid and acrylic ester has been introduced (for example, DRASIL-ANG available from the Henkel Company) at the concentration of about 4-6 g/1 and making the resin to polymerize definitively with the aid of the addition of formic acid for a period of about 30-45 minutes at a temperature of about 60°C.
  • the resin becomes deposited on the surface of the pierced hide at the points corresponding to the inner walls of the holes, where the resin itself becomes absorbed by the fibers uncovered as an effect of the piercing step, so that the advantageous effect, al ⁇ ready mentioned above, of the increase in the surface strength of the hide is obtained.
  • the object of the present invention concerns also the hides ob ⁇ tained by means of the process mentioned above.
  • Figure 1 is a block diagram of the process according to the pres ⁇ ent invention.
  • Figure 2 is a schematic perspective view of a shoe realized em ⁇ ploying leather obtained according to the present invention.
  • a biological phase of the treatment comprising the soaking step, the fleshing and the washing step, a transition step consisting in the pickling operation and an anabiological step comprising the tanning, acid removal and re ⁇ tanning operations.
  • the dry working (B) comprises the finishing, piercing, treatment with an acrylic polymeric compound which is a feature of the invention, and the successive finishing step.
  • a stock of sheep raw hides bearing wool is dipped into a cold water bath (one hide for each volume of 20 1 of water), said bath con ⁇ taining FORYLL BB, a surface active agent commercially available from the Henkel Company, at the concentration of 1 g/1, and the whole bath is left standing overnight, and in the morning it is next washed with tap running water till water comes out clean, then FORYLL BB (1 g/1) and REVERDASE 120 (0.2 g/1) are added, and the hides are left in the bath for 48 hours (the soaking step); b) after the fleshing step, a bath is prepared consisting of water at 35-38°C and of 1.5 g/1 of perchloroethylene (as the solvent) and 3 g/1 of FORYLL BB (the surface active agent), and the hides are left dipped in such bath at the proportion of one hide for each 20 1;
  • Such pickling operation aims at preparing ' the hides to the chrome tanning step, making them more suitable to be passed through rapidly by the chromium salts which as a result of the acid character of the bath become less reactive so that consequently their penetration is more uniform.
  • the addition of salt is necessary to avoid the swelling of the hides as an effect of the acid present; d) said hides are then treated as follows (the tanning step) : 2 hours in a bath of cold water (one hide for each 20 1) contain ⁇ ing liquid chromium salt, the GRASSAN DHS commercially available form the Henkel Company is added in the proportion of 1.6 g/1, the bath is kept standing for 1 hour, then IMPLENAL AP commercially available from the BASF Company is added and the hides are kept in the bath for an additional hour, and finally 10 g/1 of liquid chromium salt is added keeping the hides in said bath for 2 or 3 hours; finally, 1 g/1 of sodium carbonate and 1 g/1 of sodium bicarbonate are added, keeping the
  • the last addition of an alkaline compound in the final step serves the purpose of making the chromium compound molecule larger and of fixing the same to the hide between its fibers so as to obtain a well tanned hide that shows strong and firm; e) in the acid removal step that is carried out after the matu ⁇ ration of the tanned hides by a rest period of about 48 hours on a beam, a bath of water at 45°C is employed, in which bath said hides are dipped (at the proportion of one hide for each 20 1 of water); then, 2 g/1 of ' CORATIL ND is added, the treatment being performed for 1 hour, then 3 g/1 of GRASSAN DHS is added, the treatment being carried out for an ad ⁇ ditional hour; f) the retanning step is finished, after carrying out the re ⁇ tanning step according to the traditional procedure, by inserting a treatment with an acrylic resin, such treatment being a characteristic feature of the present invention; as a matter of practice, hides are treated in
  • the dry working step is performed; g) after the traditional finishing operation by previously ap ⁇ plying to the hide a water dispersion of an aliphatic polyurethane (Astacin Finish PUD) in the proportion of 80-100 g/hide at 110°C and 150 at . with the consequent formation of a polymeric coating, the puncturing or piercing operation is carried out.
  • Astacin Finish PUD an aliphatic polyurethane
  • the second step which forms a characteristic feature of the present invention occurs by dip ⁇ ping the hide in a bath of water kept at 50-60°C containing DRASIL-ANG available from the Henkel Company, which is a prepolymerized methacrylic resin in water solution, at the concentration of 4-6 g/1. Then, formic acid is added at 60°C over a period of 45 minutes and the polymeriza ⁇ tion is completed with the formation of a deposit on the surface of the pierced or punctured hide at points corresponding to the inner parts of the holes (h) and a further finishing (i) is performed.
  • DRASIL-ANG available from the Henkel Company
  • Figure 2 shows an application of the leather obtained according to the present Invention for the production of the upper of a footwear; the woll layer 1 can be seen on the inner side of the footwear, while the velvet leather or the napped leather 2 provided with holes 3 can be seen on the outer part of the same.
  • the tests performed on a specimen of ram skin after treating the same according to the present Invention (specimen A) and on a specimen (B) of an untreated ram skin are as follows: • determination of the tensile and elongation strength; determination of the tear resistance; determination of the stretching and of the tensile strength of the grain of leather by the method of the ball; determination of wear resistance by repeated continuous folding of light leather and of their surface sizing.
  • the specimens opportunely conditioned undergo a tensile stress to failure on a tensile test device.
  • the tensile strength is obtained dividing the breaking or failure
  • the ultimate elongation is calculated by the difference between the initial length of the specimen and its ultimate length. Such difference is expressed as the percentage with respect to the initial length of the specimen.
  • a rectangular specimen in which a slit has been out of the pre ⁇ scribed shape is hooked on the protruding ends of a pair of specimen holders fastened between the clamps of a tensile test device.
  • the max ⁇ imum elongation stress required for causing said specimen holders to separate is considered as the value of the tearing strength.
  • a steel ball is pressed onto the central part of the flesh side of a leather specimen cut in the shape of a disk which is firmly fas ⁇ tened along its peripheral part.
  • the ball pressure and the consequent stretching of the specimen are recorded at the very moment when the leather grain becomes cracked and bursting of leather (possibly) occurs.
  • Standard procedure UNI 8433/TUP 20 - determination of repeated employment resistance (the employment consisting in continuous folding) of light leather and leather surface sizing.
  • Such determination is performed by clamping each specimen to the two terminals of the testing apparatus.
  • One of the two clamping terminals is kept stationary while the other one is caused to oscillate with 22.5° amplitude at the frequency of 100+5 cycles/minute, so carrying with itself the folded specimen.
  • the specimens undergo after conditioning a tensile stress till failure on a tensile strength test machine.
  • the tensile strength is calculated by dividing the ultimate ten ⁇ sile load by the cross section area of the specimen and is expressed
  • the ultimate elongation is obtained by calculating the difference between the initial length of the specimen and its ultimate length. Such difference is expressed as the percentage with respect to the ini ⁇ tial length of the specimen.
  • a rectangular specimen in which a slit has been cut of the pre- scribed shape is hoocked on the protruding ends of a pair of specimen holders fastened between the clamps of a tensile test machine.
  • the maximum elongation load required for causing the specimen holders to separate is considered as the tearing strength.
  • a steel ball is pressed against the central part of the flesh side of a leather specimen cut in the shape of a disk and firmly fastened along its peripheral part.
  • the pressure of the steel ball and the stretching of the specimen are recorded at the very moment when the leather grain becomes cracked and the bursting (possibly) occurs.
  • Such determination is carried out by fastening each specimen to the two clamps of the testing apparatus.
  • One of the two clamps is kept stationary whereas the other one is made to oscillate with amplitude of 22.5° at the frequency of 100 +_ 5 cycles/minute so carrying with itself the folded leather specimen.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Treatment And Processing Of Natural Fur Or Leather (AREA)
  • Footwear And Its Accessory, Manufacturing Method And Apparatuses (AREA)

Abstract

Procédé pour la production du cuir destiné à la confection de tiges de chaussures se portant à la période printemps-été, dans lequel, après l'étape classique de travail au bain et pendant le travail de séchage, après l'opération de perforation ou de perçage des peaux, deux traitements séparés sont effectués avec des résines acryliques qui, une fois polymérisées, confèrent aux peaux respectivement d'une part une densité et une résistance améliorées et d'autre part, par suite de l'enduction de la surface intérieure de la peau au niveau des points correspondants aux perforations ou trous, une augmentation de la résistance de surface de la peau, ce qui évite les risques de dilatation ou d'allongement et de déchirure des chaussures lorsqu'on les porte.
EP87902692A 1986-11-18 1987-04-13 Procede pour la production de cuir destine a la confection de tiges de chaussures et produit obtenu Expired - Lifetime EP0324734B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT87902692T ATE62277T1 (de) 1986-11-18 1987-04-13 Verfahren zur herstellung von schuhoberleder und produkt daraus.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT4866686 1986-11-18
IT48666/86A IT1199294B (it) 1986-11-18 1986-11-18 Procedimento per la produzione di pelli destinate alla fabbricazione di tomaie per calzature e relativo prodotto

Publications (2)

Publication Number Publication Date
EP0324734A1 true EP0324734A1 (fr) 1989-07-26
EP0324734B1 EP0324734B1 (fr) 1991-04-03

Family

ID=11267929

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87902692A Expired - Lifetime EP0324734B1 (fr) 1986-11-18 1987-04-13 Procede pour la production de cuir destine a la confection de tiges de chaussures et produit obtenu

Country Status (22)

Country Link
EP (1) EP0324734B1 (fr)
JP (1) JPH02500444A (fr)
KR (1) KR890700169A (fr)
CN (1) CN1013205B (fr)
AU (1) AU606059B2 (fr)
BG (1) BG50390A3 (fr)
CS (1) CS275887B6 (fr)
DD (1) DD279691A5 (fr)
FI (1) FI892363A0 (fr)
HU (1) HU203386B (fr)
IL (1) IL84437A (fr)
IT (1) IT1199294B (fr)
MA (1) MA21110A1 (fr)
NZ (1) NZ222559A (fr)
PL (1) PL156512B1 (fr)
PT (1) PT86161B (fr)
RO (1) RO103963B1 (fr)
RU (1) RU1777608C (fr)
TR (1) TR23044A (fr)
WO (1) WO1988003958A1 (fr)
YU (1) YU209087A (fr)
ZA (1) ZA878523B (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5172228B2 (ja) 2007-06-28 2013-03-27 ミドリホクヨー株式会社 革
JP5272478B2 (ja) * 2008-04-02 2013-08-28 トヨタ紡織株式会社 皮革の孔開け加工方法
EP2284285A4 (fr) * 2008-05-16 2013-03-20 Midori Hokuyo Co Ltd Couche de finition
CN105296690B (zh) * 2013-10-21 2018-06-22 晋江市香江皮革有限公司 一种耐曲折皮革的生产方法
CN103866053B (zh) * 2014-04-02 2015-09-30 宁夏盐池美雅滩羊裘皮有限公司 一种鞣制滩羊二毛裘皮的工艺
KR101686896B1 (ko) * 2016-08-31 2016-12-15 허민수 양모섬유를 이용한 신발 및 신발의 제조에 이용되는 갑피의 제조방법

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3843320A (en) * 1972-05-31 1974-10-22 Us Agriculture Graft polymerization of vinyl monomers onto chrome-tanned hides and skins

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8803958A1 *

Also Published As

Publication number Publication date
AU606059B2 (en) 1991-01-31
RO103963B1 (en) 1993-12-22
YU209087A (en) 1988-12-31
FI892363A (fi) 1989-05-17
PT86161B (pt) 1990-11-20
ZA878523B (en) 1988-10-26
HUT50362A (en) 1990-01-29
DD279691A5 (de) 1990-06-13
HU203386B (en) 1991-07-29
KR890700169A (ko) 1989-03-10
PL268885A1 (en) 1988-08-18
FI892363A0 (fi) 1989-05-17
EP0324734B1 (fr) 1991-04-03
CN87107924A (zh) 1988-06-01
IT8648666A0 (it) 1986-11-18
RU1777608C (ru) 1992-11-23
NZ222559A (en) 1990-01-29
PT86161A (en) 1987-12-01
IT1199294B (it) 1988-12-30
PL156512B1 (en) 1992-03-31
JPH02500444A (ja) 1990-02-15
CN1013205B (zh) 1991-07-17
WO1988003958A1 (fr) 1988-06-02
IL84437A0 (en) 1988-04-29
IL84437A (en) 1991-05-12
MA21110A1 (fr) 1988-07-01
BG50390A3 (en) 1992-07-15
CS275887B6 (en) 1992-03-18
JPH0569879B2 (fr) 1993-10-01
TR23044A (tr) 1989-02-13
AU7302587A (en) 1988-06-16

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