AU613338B2 - Biologically stabilized and untanned hides and process for obtaining these hides - Google Patents

Abstract

These hides, completely free from chromium, have a moisture content of between 15 and 20%, a maximum inorganic matter content of 10 +/- 2%, an aluminium oxide content of 0.7 +/- 0.2% and an acrylic derivatives content of approximately 2%. Their pH is in the region of 4.0% and their dermic substance content is approximately 85 +/- 3%. They are capable of being rewetted in less than an hour. The process for obtaining them, of the type consisting in subjecting the completely delimed and bated hides to a pickling treatment in the presence of acrylic resin and then, after a rest, to a pretanning treatment with the aid of aluminium salts, is characterised in that there is introduced at any stage of the treatment a chemical agent facilitating the rewetting and enabling the hide to retain, after drying, a residual moisture close to 20% and in that the hide thus treated is subjected to drying. This chemical agent is chosen from the group consisting of polyalcohols, condensates of fatty alcohols with ethylene oxide and condensates of alkylphenols with ethylene oxide.

Description

ZAXM~ismd~mi~HO D Form COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952-69 COMPLETE SPECIFICATION

(ORIGINAL)

013338 Class I t. Class Application Number: Lodged: goiliplete Specification Lodged.

Accepted: Published: Pri ofity; ReI3j4ted Art: ii Ti

IT

Narmeof Applicant: CENTRE TECHNIQUE CUIR CHAUSSURE MAROQUINERIE Address of Applicant; 9 avenue JulesCarteret, 69007 Lyon, France Actual Inventor: Address for Service: GERARD GAVEND, BERNARD VULLIERMET, RAYMOND GERVAIS and JEAN PORE EDWD. WATERS SONS, 50 QUEEN STREET, MELBOURNE, AUSTRALIA, 3000.

HARAN, MICHELE Complete Specification for the invention entitled: BIOLOGICALLY STABILIZED AND U',ANNED HIDES AND PROCESS FOR 013TAINING THESE HIDES The following statement is a full description of this Invention, Including the best method of performing it known to noun" agents with a hyprosco 00 iL EdWd. WJteIrs Sons.

MelboUne.

i Itt, I I t1 I 4* I Ir *t I I It BIOLOGICALLY STABILIZED AND UNTANNED HIDES AND PROCESS FOR OBTAINING THESE HIDES Field of the Invention This invention relates to biologically stabilized and untanned hides and the process for obtaining these hides.

Background of the Invention It is known that hides, and particularly hides for tanneries, are now marketed under different forms depending sn their state of processing.

Thus, these hides can be delivered in the raw state, having undergone a simple treatment intended to prevent or stop microbial development, such as salting, salting and drying, drying and the like. They can be delivered in the pickled state, after having undergone a simple preparation by treatment with a strong acid solution in the presence of salt, or also after having been chrome tanned (wet blue treatment) or otherwise; finally, the hides can be delivered in the semiworked state (crust) or finished state.

One of the important problems that now arises in the leather industry is to be able to detect defects existing in hides as early as possible in the course of leather transformation to allow a better orientation of the hides, depending on their quality and the needs of the market. This information is also essential to specialists of different preparation stages to enable them possibly to modify their mode of treatment.

Now, with each state and with each form of presentation is associated a group of advantages and drawbacks. As a general rule, any orientation of the raw state to the finished state is accompanied by an i improvement of the possibilities of appreciation of the quality of the material, of an increase of its stability l -and its life, an optimizing of the material balance in production; on the other hand, the field of diversification becomes increasingly narrow.

tr2 S4 I; The main advantages and drawbacks linked to the presentation of most frequently marketed leathers and hides are summarized in the following table: Advantages Drawbacks ti t t 15 t I t f r t t I~ I DRIED HIDES Shipping Storage and preservation SALTED HIDES Preservation Diversification PICKLED HIDES Diversification Difficulty in rewetting Accident on hair side Salt pollution Irregularity Hydrolysis and fatigue Shipping Irreversible chrome Nonrewettability Background color No possibility of diversification Cost WET BLUE Ease in sorting Stability Adding of pollution No secondary products Shipping Transparency of market

CRUST

Therefore after the pickling stage it should be possible to have hides that could be oriented according to the needs of the market, since at this stage these hides have not undergone irreversible chemical treatments; however, they are relatively fragile.

Hides, called Wet Stabilized White (WSW), have been developed which partly meet these requirements; they are hides which have been subjected to a pretanning treatment in the presence of alumina sulfate after pickling in the presence of acrylic resins.

3 n. aI These wet hides with Fa clear tint contain about 60% water, 1 to 10% mineral materials, less than 1% aluminum oxide, the level of hide substance coming to 85-90%.

The behavior of these hides during storage is satisfactory for periods that can go up to six months and more.

However, the WSW hides have certain drawbacks, especially in regard to their considerable water content, which makes them difficult to handle and J au greatly increases their shipping cost.

°o°o Therefore it might be thought that the best oa,. solution would be to subject the WSW hides to a. drying to eliminate excess water. But experience has shown *that then very stiff, even brittle, parchment type j hides, therefore very difficult to store, would be obtained. On the other hand, the hides thus dried would be practically impossible to rewet. The:efore, it was j l advisable to find a means enabling the dried hide to preserve a sufficient level of moisture, which tests have shown should be between 18 and 20%, without there'y i losing the qualities imparted to Wet Stabilized White treated hides; it was also advisable to enable the dried hide to be easily integrated into the cycle of later 2*l" 5 fabrications, for it to be able to be easily rewetted in °a reasonable period, which should be less than an hour.

The applicant therefore established criteria for selection of the numerous chemical wetting agents to make it possible to determine those that were capable of meeting these requirements. These criteria are the following: These agents should exhibit a good stability in a pH range going from 2.5 to 4 They should be compatible both with aluminum salts and with acrylic derivatives used, as will be seen below, in special pickling and pretanning treatments, or any others used for this purpose.

They should be capable of exerting an action of solubilizing and distributing mineral salts, so that, during drying, no crystallization occurs under the grain which would risk giving the hide a granular appearance.

They should be compatible with the products used later for tanning, whether it be vegetable tanning, mixed tanning (vegetable--synthetic) or mineral tanning (chromium, zirconium, titanium).

They should enable the hide to retain r t sufficient residual moisture to give it the flexibility rft* essential for handling and storage, while maintaining 0" the structural moisture of the collagen fiber.

They should permit an easy drying of the hide, and rewetting to the core in less than an hour, the retraction temperature of the wetted form being as high as possible.

Their presence should not constitute an obstacle to the performance, after rewetting, of a dry degreasing treatment, and the aptitude for rewetting should not be modified by this degreasing treatment.

2 5 Finally, their price should be low enough not to modify the price of the hide notably.

i Summary of the Invention A selection made of numerous products, according to the above criteria, enabled the inventors to determine that the best performing products were in the group consisting of polyalcohols, condensates of fatty alcohols on ethylene oxide and condensates of alkylphenols on ethylene oxide.

5 Thus, this invention relates to clear hides, biologically stabilized and untanned and which will be called "Dry Stabilized White," which are characterized in that, totally free of chrome, they exhibit a moisture content between 15 and 20%, a maximum content of mineral materials of 1 to 12%, aluminum oxide content of 0.7 a possible content of acrylic derivatives of in that their pH is in the vicinity of and in that their level of hide substance is at about 85 3%m and in that they can be rewetted in less than an hour. The hides also contain a small amount of a product selected from the group consisting of polyalcohols, condensates of fatty alcohols with ethylene oxide, and condensates of alkylphenols with ethylene oxide.

10 This last property, quite decisive to enable the hides according to the invention to be subjected, even after a long storage period, to the sequence of standard treatments, and particularly tanning, is obtained thanks to the presence in the dry stabilized white of a small amount of the specially selected chemical agents mentioned above.

The invention makes it possible to produce, after the pickling stage where the ,hide Is still diversiflable but relatively fragile, a hide which can be described as biologically preserved which exhibits the following advantages: ease of storage and shipping, partially because of its low moisture ,content; inertia In regard to aging; reasonable production cost; very broad capability for diversification (including grain and flesh split for different destinations); better integration In the environment (reduced water pollution and obtaining of chrome free solid wastes); aptitude of later undergoing all the subsequent tanning treatments.

-j LT- IY~m~ The invention also has as its object a process for obtaining hides known as Dry Stabilized White described above.

This process is of the type consisting in subjecting the skins, unlimed cold and bated, to a pickling treatment optionally in the presence of acrylic resins and then, after standing, to a pretanning treatment with aluminum salts and it is characterized in that there is introduced, in any phase of the treatment, a chemical agent facilitating rewetting and enabling the hide to preserve, after drying, a residual moisture close to 20%, and in that the hide thus treated is subjected to a drying.

According to one embodiment of the invention, the chemical agent facilitating the rewetting is introduced in the pickling stage.

According to another embodiment, said chemical agent is introduced in the pretanning stage.

According to another embodiment, said chemical agent is deposited on the wet hides by any process of spraying, projection or coating, flesh side and/or hair side.

Alternately, said chemical agent is introduced during a later step, after pickling and pretanning.

Detailed Description of the Invention The chemical agent facilitating rewetting is selected, as indicated above, from the group consisting of polyalcohols, condensates of fatty alcohols on ethylene oxide and condensates of alkylphenols on ethylene oxide.

The inventors also determined that it was especially important to allow later rewetting and degreasing of the hides thus treated to incorporate in them a mixture of a hygroscopic compound and an emulsifier as well as a cosurfactant able to promote 7 putting into microemulsion the natural fats present in the native hide, to improve the qualities, the appearance and the market value thereof.

Thus, according to one embodiment of this invention, there is incorporated into the hides a certain amount of an emulsifier exhibiting a hydrophilic lipophilic balance (HLB) determined to be identical with the required HLB (RHLB) of natural fatty materials, with addition of a cosurfactant to allow their dispersion in the form of microemulsions during rinsings performed at a temperature greater than melting point of these fatty materials in the presence of salts, avoiding acid swelling if necessary.

Besides the emulsifying power of the compounds with surface activity relative to the fats under operating conditions of acidity and/or salification, there are also imparted to the hides a good hygroscopic power, improved ease in rewetting associated with lubricating properties, antifungal and antibacterial properties and an absence of crystallization.

The relative proportions of the compounds to be used are the following: emulsifier 30 to hygroscopic product 20 to cosurfactant 5 to fungicide or bactericide i to lubricant 5 to According to the invention, the cosurfactants can be defined as hydrophilic products (alcohols, glycols or polyglycols, amines, amino alcohols, for example) which, added to the surfactants, assure the obtaining of microemulsions by increasing their HLB.

The emulsifiers are selected from the oxyethylene compounds resulting from the condensation of ethylene oxide or propylene oxide with long chain compounds, such as octylphenol or nonylphenol, polyols, 8 i N~ r~a~Mn~ alcohols having a chain between C 8 and C 1 8 and exhibiting an HLB between 6 and 18, or a mixture of two or more compounds of this type.

The hygroscopic product is selected from the following compounds: glycerol, polyglycerol, sorbitol, trimethylolpropane, polyethylene glycol alone or in mixture, hygroscopic or deliquescent alkaline or alkaline-':rth salts, and especially chlorides of this type.

The fungicides and bactericides are preferably quaternary ammonium salts such as trimethyl cetyl ammonium chloride or other salt of this type uniting antiseptic properties with wetting properties.

Finally, the lubricant is advantageously selected from aliphatic hydrocarbons with a chain between C 1 5 and C 3 0 The mixtures of these compounds are used at a rate of 0.5 to 6% by weight of the pelt, as a function of their nature, the dry state to which it is desired to bring the hides in dry stabilized white form or dry white, to allow their rewetting and/or their degreasing under the best conditions.

Moreover, similar compositions can be added after rewetting on the hides, after emptying of the bath, to permit their degreasing, if the amounts used during preparation of the DSW were insufficient.

The invention will be better understood and its advantages will come out from the following examples which illustrate it -thout limiting it any way.

Example 1: Production of a Wet Stabilized White hide A start is made with small skins (sheep, goats) basically unlimed and bated (colorless section with phenolphthalein).

9 1 c- ~C L- They are then subjected to a treatment in the following baths (the percentages are calculated on the pelt weight). All the treatments are performed in the same equipment.

Pickling: treatment is first in a bath containing: cold water sea salt rotation 15 minutes.

A LEUKOTANR type acrylic resin, marketed by ROHM and HAAS, is added at rate of 1% (diluted in 3% water) rotation 30 minutes.

1.3% of sulfuric acid (diluted 1/10) is added rotation 45 minutes.

Finally, 0.7% of sodium formate is added.

rotation 3 hours.

The pH of the bath is close to 3.2-3.3.

Stabilization: It is allowed to stand overnight, then there are added 3.5% of basic aluminum sulfate, 0.05% of a suitable fungicide, type BUSAN 30 L, marketed by

BUCKMAN

At rotation 3 hours.

Finally, the pH of the bath is adjusted to about 4.2 with the help of two times 0.5% sodium bicarbonate.

Then, there is drained the resulting "Wet Stabilized White" which contains about 60% water, 7 to of mineral materials and less than 1% aluminum oxide, the level of the dermal substance amounting to 85-90% of dry weight.

The resulting hides can be easily sorted and be stored at least six months before being subjected to the latter treatments of tanning and finishing.

However, it should be noted that the high amount of water that they contain makes them very heavy, and they are difficult to handle and ship.

10 r

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A drying test of the hide obtained in example 1 led to a stiff, brittle hide which is difficult to store by stacks and, which, moreover, cannot be easily rewetted.

The following exampl.-s illustrate different mode-s of production of Dry Stabilized White (DSW) hides from WSW hide,3.

Example 2 Preparation of DSW, without prior degreasing of the hide; this process more partially is intended for raw materials containing little natural fatty materials and easily rewettable (flesh split of veal or cow, hide of maximum thickness of 0.8 mm).

A start is made with hides completely unlimed and optionally bated (colorless reaction with phenolphthale in).

Then they are subjected to a treatment in a bath prepared as follows (the amounts of products added are evaluated in percentage of the pelt weight): a) preparation, of a water bath (temperature to 201C) in a fuller, paddle or other equipment normally used in tanning sheepskins whose volume is between 20 and 100% of the value of the weight of the pelts.

In this bath, an amount of soluble mineral agents is added making it possible to obtain an ionic force suited to the optimal conditions of acidification or pickling of the hides: sodium chloride or sulfate potassiuml chloride or sulfate calcium chloride mixture of acid salts, of aromatic or aliphatic acids.

Stirring of the hides in this bath for 10 to minutes.

b) progressive acidification by successive additions of amounts of previously diluted mineral or 11 organic acids (sulfuric, hydrochloric, acetic, formic acids) and soluble organic complexing salts (sodium formate, sodium acetate, sodium tartrate, sodium citrate, sodium sulfophthalate). The amounts of acids, depending on their chemical nature, are between 0.5 and and those of the complexing agents between 0 and The reactions between the hides and the chemical products incorporated in the bath should make it possible, after contact of 1 to C hours, to obtain pHs between 2,0 and c) incorporation of a stabilization agent with a slightly tanning character whose essential ingredient Sis a more or less complex salt resulting from the combination of a mineral or organic acid and aluminum.

The amounts of stabilization products used and the physicochemical conditions of the reaction (concentration, temperature, pH) should lead to o0.° Oobtaining a stabilized material whose retraction temperature is at a minimum 55°C and the pH is between and

S,

4 J 12 ii Preparation Water 16-18°C: Sodium chloride: 4% rotation of drum, 10 minutes dispersing agent: 0.8% (acrylic preparation) or other rotation of drum, 20 minutes sulfuric acid diluted 10 times: 1% rotation of drum, 60 minutes sodium formate: 0.6% rotation of drum, 4 hours 3.1 pH bath 3.3 aluminum complex salt: 3% (containing 10% A1 2 0 3 S 15 rotation of drum, 3 hours for fixing by correction of pH to have a value of 4.3-4.4 with sodium bicarbonate.

Storage on horse, 24 hours Draining under slight pressure (5 x 105 Pa) However, this draining is not essential; in 2 5 some cases, stacking in a pile or a good draining of the hides is sufficivnt.

At this stage, there is incorporated in the stabilized white materia Ln the wet state a preparation making possible both a drying without secondary effects of the migration type of adjuvant prodicts or unwanted recrystallizations, an excellent rewettig for the hide put into further production and a preparation for the dogreasing operation essential to the success of production of a quality leather from the DSW.

The preparation contains a mixture of: emulsifying and wetting agents of the nonionic type (products of oxyethylation of amines, amides, alkylphenols and alkylnaphthols, fatty acidd or alcohols); 13 It '1 4

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agents with a hygroscopic character of the glycerol, glycol and/or sorbitol or alcohol type.

Preparation recipe: Octylphenol with 12 moles of ethylene oxide 60 parts 30 parts Hexylene parts The hides, brought to the wet stabilized white state, are drummed for 15 minutes with an amount of 4% calculated relative to the weight of the merchandise to be treated with the above preparation. They are then stored for 24 hours then dried.

Example 3: Preparation of DSW, without degreasing of the hide; this process is more particularly intended for raw materials with an average content of natural fatty materials (3 to (goats, calves, bull calves).

A start is made with hides completely unlimed and optionally bated (colorless reaction with phenolphthalein).

The course of stages a) and b) is identical with that of example 2, as is the course of stage c).

Between stage b) and stage and according to the invention, is added a compound of the tawing paste oil or auxiliary type with a cationic character (hydroxyethyl derivative of fatty amines) in amounts between 0.2% and Example 4: Preparation of DSW, without degreasing of the hide, more particularly intended for raw materials with a high content of natural fatty material (greater than (lambs, sheep, hybrids, hogs).

In this case, the operation in a first period is similar to that of example 2, up to the storage and draining stages. At this level, thero is incorporated in the stabilized white material in the wet state a 14 preparation making possible both a dying without secondary effects of the migration type of adjuvant products or unwanted recrystallizations, an excellent rewetting for the hide put into further production and a preparation for the degreasing operation essential to the success of production of a quality leather from the

DSW.

The preparation contain,- a mixture of: emulsifying and wetting agents of the nonionic type (products of oxyet:hylation of amines, amides, alkylphenols and alkylnaphthols, fatty acids or alcohols); agents with a hygroscopic character of the glycerol, glycol and/or sorbitol or alcohol type.

In this example, this mixture is the following: Octylphenol with 12 moles of ethylene oxide 60 parts 30 parts Butyl glycol..... 10 parts The hides, brcught to the wet stabilized white state, are drummed for 15 minutes with an amount of 4% of thi mixture calculated relative to the weight of the merchandise to be treated with the preparation described above. They are then stored for 24 hours then dried, as in example 2.

Example 5: Preparation of DSW, with prior degreasing of the hide, more particularly intended for raw materials with a high content of natura.l fatty materials.

Starting stage A start is made with hides completely unlimed and, optionally, bated (colorless reaction with phenolphthalein).

15 2 The hides are first fulled in a moderate bath containing an emulsifier and a solvent of natural fatty materials or a commercial preparation whose composition is obtained from these basic agents.

For particularly fatty origins, the degreasing is performed in two, even three successive stages, interrupted by rinsings.

The degreased wet hides are then drained, then a mode of operation of the type of that in. example 2 is followed.

Example 6: Preparation of DSW, with prior I degreasing of the hide, more particularly intended for raw materials with a high content of natural fatty j materials.

Starting stage: A start is made with hides completely unlimed and, optionally, bated (colorless reaction with phenolphthalein).

The hides are first drummed in a moderate bath containing an emulsifier and a solvent of natural fatty I materials or a commercial preparation whose composition I is obtained from these basic agents.

For particularly fatty origins, the degreasing is performed in two, even three successive stages, interrupted by rinsings.

The degreased wet hides are then drained.

Then the hides undergo the pickling and pretanning operation; at this stage, the bath is emptied. On these well-drained hides is then introduced 3 to 4% (as a function of the fatty material content of the hides) of a preparation containing a mixture of emulsifiers of the nonionic type (products of oxyethylenation of amines, amides, alkylphenols, and/or alkylnaphthols, fatty acids, fatty alcohols) and cosurfactant. (amino alcohols, alcohols, glycols).

16 I In this example, the mixture is the following: Alkylphenol with 10 moles of ethylene oxide 95 parts Butanol 5 parts After stirring for thirty minutes, two successive rinsings of the hides are performed, in hot water or brine (30 to 45°C): 50 to 100% by weight of the-hides for thirty or forty five minutes.

After degreasing, the bath is emptied and there is applied to the hides the preparation used in example 4, by using only 2 to 3% of the composition described. The hides are then stored and dried according to the mode of operation described in example 2.

The hides obtained by using the processes described in examples 2 to 6 preserve a moisture level of about 18 to 20% which allows them easily to be integrated into the cycle of later fabrications. They are easily wetted at least one hour. After the pickling stage, therefore there is available a biologically preserved hide with all the advantages described above.

The process according to the invention applies to the preparation of WSW and DSW of all hides, unhaired or not, such as cattle, sheep, goats, hogs, reptiles, birds, fish, batrachia, waterfowl.

While the invention is described above in relation to certain specific embodiments, it will be understood that many variations are possible, and that alternative materials and reagents can be used without departing from the invention. In some cases such variations and substitutions may require some experimentation, but such will only involve routine testing.

17 The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and therefore such adaptations and modifications are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation.

ia St 4 #44 .444< t44t..

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Claims (13)

1. Biologically stabilized, chrome-free, and untanned clear hides having a moisture content of from 15% to 20%, an inorganic content of from 1% to 12%, an aluminum oxide content of from 0.5% to a pH of about 4.0, a level of dermal substance of from 82% to 88%, and a small amount of z product selected from the group consisting of polyalcohols, condensates of fatty alcohols with ethylene oxide, and condensates of alkylphenols with ethylene oxide, and which can be rewetted in at j least one hour.

2. The hides according to claim 1 further including about 2% acrylic derivatives.

3. A process for obtaining hides according to claim 1 comprising: pickling totally unlimed and bated hides; allowing the hides to stand; pretanning the hides with aluminum salts; wherein a chemical agent facilitating rewetting and preservation of the hide to preserve, after drying, a residual moisture of about 20%, selected from the group consisting of polyalcohols, condensates of fatty alcohols with ethylene oxide, and condensates of alkylphenols with ethylene oxide, is introducod at any one of the above steps; and drying the hides,

4. The process of claim 3 wherein the pickling is conducted in the presence of acrylic resin, The process according to claim 3 wherein the chemical agent facilitating rewetting is introduced in the pickling step.

6. The process according to claim 3 herein the chemical agent facilitating rewetting is introduced in the pretanning step. I

7. The process according to claim 3 wherein the chemical agent facilitating rewetting is introduced after pickling and pretanning.

8. The process according to claim 3 wherein the chemical agent facilitating rewetting is introduced at a rate of from 1% to 10% by weight.

9. The process according to claim 3 further comprising incorporating in the hides an effective amount of an emulsifier exhibiting a hydrophilic lipophilic balance which is determined to be identical with the required hydrophilic lipophilic balance of natural fatty materials, and further including a cosurfactant to permit the tdispersion of said fatty materials in the form of microemulsions during rinsings performed at a temperature above the melting point of said fatty materials in the «i presence of salts. The process according to claim 9 wherein the relative proportions of the compounds to be used are as follows: from 30% to hygroscopic product...... from 20% to 5% to fungicide or bactericide.,,,..........ifrom 1% to from 5% to

11. The process according to claim 10 wherein the emulsifiers are selected from the group consisting of oxyethlene compounds prepared by condensing ethyleneoxide or propylene oxide with an organic compound selected from the group consisting of octylphenol, nonylphenol, polyols, alcohols having a chain length of from eight to 18 carbon atoms exhibiting a hydrophilic lipophilic balance between 6 and 18, and mixtures thereof. 12, The process according to claim 10 wherein the hygroscopic product Is se icted form the group consisting of glycerol, polyglycerol, and mixtures thereof, and hygroscopic and deliquescent alkaline and alkaline-earth salts, P: 1' I 21

13. The process according to claim 10 wherein the cosurfactant is selected from the group consisting of alcohols, amines, glycols, and amino alcohols.

14. The process according to claim 10 wherein the fungicidal and bactericidal product is selected from the consisting of quaternary ammonium salts of the trimethylcetyl ammonium type. The process according to claim 10 wherein the lubricant is selected from the group consisting of aliphatic hydrocarbons having a chain length of from 15 carbon atoms to 30 carbon atoms. S "i 16. The process according to claim 9 wherein the mixture of compounds is introduced at a rate of from 0.5% to 6% weight of the pelts.

17. A method of degreasing pickled or pretannd hides comprising the method according to claim 8 further Including rinsing the hides in brine or hot water at a temperature greater than 20 0 C.

18. The process of claim 3 wherein the hides are selected from the group consisting of cattle, sheep, goats, hogs, reptiles, birds, fish, batrachia, and waterfowl, I DATED this 14th day of May 1991, CENTRE TECHNIQUE CUIR CHAUSSURE MAROQUINERIE WATERMARK PATENT TRADEMARK ATTORNEYS THE ATRIUM 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA LCG/DV