PT90724B - PROCESS FOR CURING GROSS SKINS USING AN AQUEOUS SOLUTION OF SYNTHETIC SHAVING AGENTS - Google Patents

Abstract

Aqueous solutions of synthetic tanning agents composed of (A) a lithium salt of a synthetic anionic aromatic tanning agent or its anionic non-condensed precursor and optionally (B) a water-soluble chromium, aluminium, iron or zirconium salt or its mixtures and (C) an alkali metal salt of ethylenediaminetetraacetic acid or of a pyrophosphate are prepared by mixing an aqueous solution of the components (A) and optionally (C) with the component (B) which is optionally present as an aqueous solution, and are used as tanning agents for tanning pelts or for retanning leather of all types. The lithium salts forming the component (A) are new and can be used as anti-staining agents for polyamide fibres or to improve the wet fastness of dyeings on polyamide fibres.

Description

The present invention relates to a process for the tanning of raw hides using an aqueous solution of synthetic tanning agents, their use for tanning hides and leather tanning, as well as the lithium salts of the corresponding tanning agents.

In aqueous solutions, tanning agents are generally in the form of ammonium salts. These salts are bad smelling for the end user and also cause pollution of the effluents that result from their use.

It has now been found that tanning agents in the form of their lithium salts do not have these drawbacks.

Accordingly, the present invention relates to an aqueous solution of a synthetic tanning agent, a solution comprising (A) a lithium salt of a synthetic, anionic, aromatic tanning agent or an anionic, non- condensed, and as optional components, (B) a salt soluble in an aqueous medium of chromium, aluminum, iron or zirconium or a mixture of these and

60,961

Case 1-17054 / + (C) an alkali metal salt of ethylene diaminetetraacetic acid or a pyrophosphate.

tanning agent, aromatic, synthetic, of component (A) is known per se, for example in Ullmanns Enzyklopãdie der technischen Chemie, Vol. 16, (4), pp. 158-140 (1979).

Lithium salts suitable for use in the practice of this invention are new and constitute a further object of the present invention.

The particularly interesting lithium salts are those of synthetic, anionic, aromatic tanning agents (also known as aromatic anionic synthes) as well as their non-condensed, anionic precursors.

Examples of suitable precursors are naphthalene, diphenyl, terphenyl, phenols, cresols, 4,4'-dihydroxydiphenyl sulfone, β-naphthol, dihydroxybenzenes, resorcinol, 2,2'-bis (hydroxyphenyl Jpropane and dialytic ethers as well as ether diphenyl ether and ether ether diphenyl and ether. , compounds that can be sulfonated in non-condensed, anionic precursors, in a manner known per se.

Aromatic, anionic, suitable synthetics are those that can be obtained by condensing the sulfonated precursors alone or in conjunction with more precursors, generally unsulfonated, with formaldehyde and / or urea, for example:

(I) condensates of sulfonated phenol or cresol and formaldehyde, (II) condensates of naphthalenesulfonic acid and formaldehyde, (III) condensates of 4,4'-dihydroxydiphenyl formaldehyde

-260,961

Case 1-17054 / + sulfonates with (hydroxy) aryl sulfonic acids, (IV) formaldehyde condensates of aromatic hydroxy compounds, sulfonates with aralkyl halides, (V) urea / formaldehyde condensates of phenols and phenolsulfonic acids (VI) product of the reaction of genol and a sulfonating agent in which the molecular proportion of (phenol) :( S0 ^) is (1) :( 1,1-2,2) (VII) condensates of sulfonated diaryl ethers and formaldehyde (VIII) condensates of sulfonated diphenyls or terphenols and condensate of 4,4' ^ dihydroxydiphenyl sulfone and 4,4'-dlhydroxydiphenyl sulfonate sulfonated with formaldehyde, and (X) condensates of diaryl ether sulfonic acid and 4,4'-dihydroxidiphenyl sulfone .

Condensates of types (I) - (III), (V) and (VII) - (X) are known, for example, from Ullmanns Enzyklopâdie der technischen Chemie, Vol. 16 (4), 140, 1979 and can be prepared by the methods described in the references cited above.

Type (IV) condensates and their preparation are disclosed in GB 986 621 patent description.

Type (V) condensates and their preparation are disclosed in GB 890 160 and 935 678 patent descriptions.

-3z / ^J 7

60,961

Case 1-17054 / + reaction product of type (VI) and its preparation are reviewed in European patent application 0 245 205. This reaction product can be condensed by methods known per se for type (V) condensates (qv GB 683 084J patent description.

Ready-to-use tanning salts, suitable for use as component (B) are described in the corresponding literature, they are usually chromium, aluminum, iron or zirconium salts. Typical examples of such salts are basic chromium (III) chloride or basic chromium (III) sulfate, a chromium alum, chloride or basic or acid aluminum sulfate, an alum, iron (IB) chloride or iron (III) ), zirconium oxychloride and zirconium sulphate. Mixtures of the chromium and aluminum salts, above, are also very suitable for use as a component (B). Preferred salts are:

/ CrCl ₂ (OH ₂ ) ₄ 7ci-2 H ₂ 0, / ~ Cr (0H ₂ ) ₆ 7C1 ₅ , Cr (0H) SO _{0 4} , Cr ₂ (OH) ₄ SO ₄ , KCr (SO ₄ ) ₂ .12 HgO, AlClyô H ₂ 0, A1 ₂ (SO ₄ ) ₅ «16 h ₂ o, ai ₂ (oh) ₄ so ₄ , ai (oh) ₂ ci, ai (oh) ci ₂ , kai (so ₄ ) ₂ . i2 H ₂ 0, Pe ₂ (S0 ₄ ) ₃ '9 H ₂ 0, Zr (OH) ₂ SO ₄ , ZrOCl ₂ * 8 H ₂ 0 and Zr (SO ₄ ) ₂ -4 H ₂ 0.

The preferred salts are basic chromium sulfates Cr (OH) SO ₄ and Cr ₂ (OH) ₄ SO ₄ that can be obtained from chromium alum and an alkali in an equivalent ratio of 3: 1 to 3: 2.

If the optional component (C) is used concurrently in the composition of this invention, tetrasodium ethylene diamine tetraacetate or piro-4 can be used appropriately! Λ ~ ^ /

- {_

60,961

Case 1-17054 / + sodium, neutral or acid phosphate (Νβ ^ Ι ^ θγ ^or ^ 2 ^ 1/07) · optional component (C) acts as a complexing agent and is preferably added to the composition if an agent is used iron-free tanning, provided that the iron content of the oil used in the preparation of component (A) is relatively high.

As tanning salts of the appropriate type for use as component (B) have very different molecular weights, in the weight ratio of component (A) to 0 component (B), the weights of component (B) are preferably based on metal atom of the appropriate tanning salt.

In addition, when using chromium-based tanning salts as component (C), no more than 0.375 part chromium can be used by component (A). Larger amounts of chromium would cease to be soluble in the composition and lead to non-homogeneous compositions. The preferred compositions thus contain components (A) and (B) in a weight ratio of (A) :( B) to (1) :( 0.03 to 0.5), at the base of the metal atom of the component (B ), in such a way that no more than 0.375 chromium is present, compositions having a tanning salt content as high as possible are preferred, since the tanning salts of component (B) are cheaper than The reaction product of phenol and oil used as component (A), the tanning action of the composition being based on component (A) as well as component (B). Compositions containing components (A) and (B) in a weight ratio of (A) :( B) to (1) :( 0.3 to 0.375) are therefore particularly preferred.

If the optional component (C) was used concurrently, the addition of 0.04 part by weight of component (C) per part, by weight of component (A) is sufficient to obtain the complexing activity of component (C). Thus, com-5 ~ 2

60,961

Case 1-17054 / + positions normally contain components (A) and (C) in a weight ratio of (A) :( C) to (1) :( 0 to 0.04).

A solution of this invention, diluted in 1% water, based on the solids content of component (A) and optional components (B) and (C), has a pH of no more than 5. A 1% aqueous solutions compositions of this invention preferably have a pH in the range of 0 to 3.5.

In general, the compositions of the present invention have a water content of 40 to 80, preferably 45 to 62 weight percent.

The preparation of the composition of the present invention comprises, first of all, mixing an aqueous solution of component (A) and optional component (C) with component (B), which can also be in the form of an aqueous solution . Before being mixed with the optional component (C), the component (A), for safety reasons, must first be diluted with water to give solutions of 50 to 70 weight percent of the component (A). In this case, the optional component (C) is added slowly to the aqueous solution of the component (A).

ONLY in the final stage, component (3) is added to the mixture of component (A) and optional component (C). At this stage, component (C) can be added in solid form with vigorous stirring. This is the case especially when, for example, aluminum-based tanning salts are used as a component (B). When using tanning salts of chromium has been shown, however, particularly advantageous to add the component (3) as an aqueous solution, in which case said aqueous solution is commonly heated from 60 to 90 ^Q C before mix with component (A) and optional component (C).

60,961

Case 1-17054 / +

Before all components are mixed, the composition should normally be diluted with water to the preferred water content of 40 to 80 weight percent. ,

The aqueous solution of synthetic tanning agents of this invention preferably comprises:

60% by weight of component (A), 60% by weight of component (B), 60% by weight of component (C) and water up to 100% by weight.

The compositions resulting from the present invention are fluid and are especially suitable for tanning skins or for re-tanning all types of leather.

tanning is carried out by conventional methods by treating the pre-tanned hides or leather with an aqueous solution containing the aqueous composition of the present invention and subsequently finishing the tanned material in a conventional manner, for example, by neutralization, washing, fat treatment and drying. If desired, a dyeing process can be carried out. Typically, 100 to 200, preferably 140 to 180 parts by weight of water and 5 to 40 parts by weight of the aqueous composition of the invention, per 100 parts by weight of leather or leather are used.

In particular, 100 parts by weight of skins preferably without mucus are tanned with 140 to 160 parts by weight of water and 10 to 20 parts by weight of the composition of the invention, or 100 parts by weight of conventionally tanned leather that have been neutralized, for example, with format or bicarbonate, are post-tanned with 140 to 160 parts by weight of water and 5 to 15 parts by weight of the composition of the invention. The tanned material is washed and, if desired,

-7 /

60,961

Case 1-17054 / +

greased with a conventional greasing agent based on, for example, sulfonated fish oil, sperm oil or cow hand oil. After drying, a shiny, light leather is obtained, having good light-resistant properties and a soft, compact, firm coat, as well as a soft touch.

In addition to communicating the good properties mentioned above to the tanned material, the composition of the present invention also has the considerable advantage of being particularly stable during storage. Even after storage for several months, no turbidity or flocculation of the composition can be observed.

In addition, the lithium salts of this invention can also be used to increase the moisture-resistant properties of pretenses made of polyamide fibers or as stain blockers.

Furthermore, lithium salts can also be used as dispersants, especially for dyes and chemicals.

The new lithium salts are also prepared by neutralizing anionic syntans with lithium hydroxide or lithium hydroxide monohydrate.

In the following preparatory explanation and subsequent examples, parts and percentages are by weight.

Process for preparing component (A)

Instruction A:

136.5 shares of phenol (1.45 mol) are melted at 45 C. ⁹

-860,961

Case 1-17054 / +

Are slowly added to this merger 193.4 shares of 20% oleum (SO ^ 2.08 mol) so that the temperature of the reaction mixture does not rise more than 16O ^Q C. Then the reaction mixture and stirred under reduced pressure at 26 mbar and 160 ^and G for six hours, during which time the reaction water, together with small amounts of molten phenol, is azeotropically removed from the reaction mixture. Subsequently, the reaction mixture is cooled under normal pressure at 40 ⁹ C to give 253 shares of a melt of a mixture of polyhydroxy polifenilsulfono-sulfonic acids containing the disulfonic acid of the formula (1) H0 -. ^ "S0 ₂

as the main component.

Preparative examples

Example 1: 500 parts of molten phenol are added slowly 440 shares of 66% oleum at 609C ^2-70 C and the mixture is subsequently sulfonated for 1 hour at 100 C. ²

The resulting phenolsulfonic acid is then slowly heated to 16O2C-165 ⁹ C under a vacuum of approximately 14-17 mbar, in such a way that only a small amount of phenol is distilled, and is maintained at this temperature until 1 g of the condensate is neutralized. in 35 to 37 cm of Congo red aqueous IN sodium hydroxide. When condensate thus obtained are added to 90-100 parts of phenol and once the phenol has been vigorously stirred, the reaction mass is again heated slowly to 165 C under vacuum ² g of the condensate to neutralize 1 is only 2, 7 to 2.5 cm ⁹ in red

60,961

Case 1-17054 / +

Congo from aqueous sodium hydroxide solution.

Yield: 900-940 pieces.

parts of the above condensate are diluted with 36 parts of water and the solution is neutralized with 16.2 parts of lithium hydroxide monohydrate. After the addition of 13.1 parts of 37% formaldehyde, the condensation is carried out at 1OO, 1O5 ² C ² C until clear a sample, diluted with a small amount of water and then acidification with dilute sulfuric acid (.aproxi . 6 hours). The reaction mass is then diluted with 50 parts of water and the resulting tanning agent is adjusted to pH

3,5 with 13 parts of 40% sulfuric acid and acidified with 14 parts of 85% formic acid.

The tanning agent solution, stable, cleaned so ohtiaa has a total solids content of approx. 47%. This tanning agent is ideally suited to the preparation of white leather.

Example 2: To a solution of 70 parts of the phenol and oleum reaction product, prepared according to Instruction A, 30 parts of water are slowly added and the pH is adjusted to 3.5 with 20 parts of sodium hydroxide monohydrate lithium. The temperature of the reaction mixture should not exceed 7O ² C. The resulting solution is acidified with 10 parts of acetic acid 75% (total solids content approx. 56%). The chrome-tanned leather on the side of the hair treated with this solution of the tanning agent in a conventional manner is fully coated with fur and has a smooth feel.

Example 3: To a solution of 166.5 parts of the phenol and oleum reaction product, prepared according to Instructions A, 100 parts of water and 4 parts of ethylenediamine-10t

60,961

Case 1-17054 / +

tetrasodium tetraacetate 4.5 parts of lithium hydroxide monohydrate are added slowly so that the temperature of the reaction mixture does not exceed 70 ° C. The reaction mixture is kept at 70 ⁹ C for 15 minutes with stirring to form a clear solution. A solution, pre-heated to 7O ² C, 198 parts of Cr (0H) ^ S0 (corresponding to 62.3 parts of chromium) 360.5 shares in water is then added to the reaction solution. Subsequently the reaction solution is kept for 20 minutes at 70 ³ C with stirring, then diluted with 166.5 shares of water and cooled to 20 C. ^and the homogeneous composition is stored after 3 months, ie, does not give no turbidity or flocculation.

Example 4: To a solution of 150 parts of a reaction product obtained by heating 51 parts of a mixture of naphthalenesulfonic acid, 51 parts of 4.4 ^1- dihydroxydiphenyl sulfone, 25 parts of water and 23 parts of a 30% formaldehyde solution are added slowly 1.5 parts of tetrasodium pyrophosphate and 20 parts of water and the pH of the mixture is adjusted to 3.5 with 11.5 parts of lithium hydroxide monohydrate. The temperature of the reaction mixture must not exceed 70 ⁵ C. The resulting solution is acidified with 20.9 parts of 75% acetic acid (total solids content approx. 57%).

The processes described in Examples 1, 2 and 4 are repeated, using condensates (II), (IV), (V) and (VII) to (X) to give the corresponding lithium salts.

Application examples

Example A: 100 parts of calf skin, cleared of mucus, are treated with 150 parts of water and 51 parts of the composition prepared according to Example 1, for 24 hours at

60,961

Case 1-17054 / +

2020 in a rotating drum. The treated skin is washed, treated with grease, stretched, dried, conditioned, stacked and studded to give a tanned, white leather, being completely covered with fur and having a soft touch.

Example B: 100 parts of calf leather, chrome-tanned, shorn, are treated with 150 parts of water and 10 parts of the composition prepared according to Example 3 for two hours in a 5020 rotating drum. After washing, the leather is neutralized in a conventional manner with sodium formate and sodium bicarbonate, washed, dyed with a part of the CI Acid Brown 189 leather dyeing agent and post-treated with a sulfonated fish oil greasing agent. The leather finish as described in Example A gives a shiny, brown, retanned leather that is also completely covered in fur and has a soft feel.

Example C: 100 pieces of a polyamide carpets are tratadaí for 15 minutes at 60 ² C with an aqueous solution which contains 5 parts of lithium salt obtained according to Example 4, 1 part magnesium sulfate, and 5 parts of ammonium acetate, which has been adjusted to pH 2.5 with formic acid. The treated carpet is then wiped with cold, dry water. The treated carpet has no affinity at room temperature for CI FE&C Red 40.

Example D: 100 g of polyamide 66 mesh fabric is placed at 40 ^s C in a solution (ratio of solution to product 1:40) which contains 2 g of a leveling agent, anionic, commercially available and 1.2 g of a dye and which is adjusted with acetic acid to pH 5. With constant circulation of the solution, the dye bath is heated to 98 ° C for 30 minutes and the dyeing is carried out at this temperature for 30 minutes. 0 dyeing bath-1260,961

Case 1-17054 / +

2 ^ -1 is then cooled and the substrate rinsed with water.

The substrate is then placed at 70 ° C in a solution (ratio of solution to article 1:40) containing 5 g of the condensate of 4,4'-dihydroxydiphenyl sulfone and phenol sulfonated with formaldehyde and adjusted with acetic acid to pH

4. 0 substrate ² is treated at 70 C for 15 minutes and then the bath is cooled. The substrate is rinsed and dried. The knitted fabric has strengthened moisture resistance properties.

The first application for the invention described above was filed in Switzerland on 6 June 1988 under ο N9 2137 / 88-0.

Claims (13)

- CLAIM.- Process for tanning raw hides or shortening leather with synthetic tanning agents, characterized in that raw hides or leather are usually treated with an aqueous solution of synthetic tanning agents, which contain (A) a lithium salt of a tanning agent or a pre-product, non-condensed, anionic and optionally (B) a chromium, aluminum, iron or zirconium salt, soluble in aqueous medium, or mixtures thereof (C) an alkali metal salt of ethylene diaminetetraacetic acid or a pyrophosphate. 2. A process according to claim 1, characterized in that component (A) is a lithium salt of a synthetic, anionic, aromatic tanning agent. 60,961 Case 1-17054 / + 5. A process according to claim 2, characterized in that component (A) is a lithium salt of a sulfonated phenol or cresol condensation product and formaldehyde. 4. A process according to claim 2, characterized in that component (A) is a lithium salt of a naphthalene sulfonic acid-formaldehyde condensation product. 5. A process according to claim 2, characterized in that component (A) is a lithium salt of a condensation product of formaldehyde and 4,4'-dihydroxydiphenylsulfone with (hydroxy) arylsulfonic acids. 6. A process according to claim 2, characterized in that component (A) is a lithium salt of a formaldehyde condensation product of aromatic hydroxy compounds, containing sulfo groups with aralkyl halides. 7. A process according to claim 2, characterized in that component (A) is a lithium salt of a urea-formaldehyde condensation product of phenols and phenol-sulfonic acids. 8. A process according to claim 2, characterized in that component (A) is a lithium salt of a condensation product of sulfonated diaryl ethers and formaldehyde. 9. A process according to claim 2, characterized in that component (A) is a lithium salt of a condensation product of sulfonated di- or terphenylenes and formaldehyde. 10 ^ .- Process according to item 2, characterized in that component (A) is a lithium salt of a condensation product of 4,4'-dihydroxydiphenylsulfone and 4,4'-dihydroxydiphenyl- sulphone sulfonated with formaldehyde -14Hi 60,961 Case 1-1754 / + 113. The method of claim 2, wherein component (A) is a lithium salt of a condensation product of diaryl ether sulfonic acid and 4,4'-dihydroxydiphenyl sulfone and formaldehyde. 12. A process according to claim 1, characterized in that component (A) is a lithium salt of a phenol reaction product is a sulfonating agent in which the molecular proportion of (phenol): (S0 ^) is (1) :( 1,1-2,2). 13. The method of claim 1, wherein component (B) is chromium (III) chloride or sulphate, basic, a chromium alum, optionally aluminum chloride or sulphate, basic, an alum, chloride or iron (III) sulfate, zirconium oxychloride or optionally basic zirconium sulfate or mixtures of the mentioned aluminum or chromium salts. ^§ 14 .- The process according to claim 13, wherein component (B) is / CrCl ^ (OH ^) ^ 7C1'2 H20, Z ^_ C'r (OH2) ₆ 7cl _5, Ur (OH) SO ₄ , Cr ^ (OH) SO ^, Kcr (S0 ₄ ) ₂ * 12 H ₂ 0, AÁCl ^ -6 H ₂ 0 A / ₂ (SO ₄ ) ₅ * 16 H ₂ 0, A / ₂ (0H) ₄ S0 ₄ , A £ (OH) ₂ Cl, A / (OH) C1 ₂ , KA% (SO ₄ ) ₂ * 12 H ₂ 0, Fe ₂ (SO ₄ ) y9 H ₂ 0, Zr (0K) ₂ S0 ₄ , ZrOCl ₂ -8 H ₂ 0 and Zr (SO ₄ ) ₂ * 4 H ₂ 0. 15. A process according to claim 1, characterized in that component (C) is a tetra-sodium salt of ethylenediamine-tetra-acetic acid or neutral or acidic sodium pyrophosphate. 169, - Process according to claim 1, characterized in that the aqueous solution used is a mixture from: 5 The 60% in Weight of component (THE), 0 The 60% in Weight of component (3), 0 The 60% in Weight of component (C) and if you add water