EP1427861A1

EP1427861A1 - Emulsifying agent composition and low-fogging, high-exhaust stuffing agent, the production and utilization thereof

Info

Publication number: EP1427861A1
Application number: EP02777026A
Authority: EP
Inventors: Gunther Pabst; Andreas Seitz; Ralph Lunkwitz
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2001-09-07
Filing date: 2002-09-06
Publication date: 2004-06-16
Also published as: DE10143949A1; AR036417A1; WO2003023069A1; US20040216241A1; CN1551924A; JP2005502458A; CN1238527C; BR0212245A; KR20040044859A

Abstract

The invention relates to an emulsifying agent composition which is particularly suitable for the production of low-fogging, high-exhaust stuffing agents, the stuffing agents thus produced and preferred and the utilization of an emulsifying agent composition and the stuffing agent in the production of leather.

Description

Emulsifier composition and low-fogging, high-exhaustion fatliquoring agents, their production and use.

The present invention relates to an emulsifier composition which is particularly suitable for the production of low-fogging, high-exhaustion fatliquoring agents, the fatliquoring agents thus obtained and the use of the

Emulsifier composition and the fatliquor in the production of leather as well as the manufactured, low-fogging leather.

Greasing agents are used in leather production to soften the leather, to increase its fullness and strength and to protect it from moisture, dirt and chemical influences from outside (see H. Herfeld, "Library of Leather", Vol. 4, (1985), P. 13 ff.).

Commercial greasing agents generally consist of greasing substances, such as chemically modified native fats, fatty oils, waxes, resins and their derivatives and / or petroleum fractions and their derivatives, and wax-like products such as "wool fat", in raw, purified and / or prepared (Lanolin) form, (see H. Herfeld, "Bibliothek des Leders", vol. 4, (1985), pp. 59 ff.) The fatty substances can, if desired, be chemically modified, ie they can be in a modified chemical structure.

Combinations of unmodified greasing substances, so-called neutral fats, and chemically modified greasing substances are mostly used for greasing.

The chemical modification of the fatty substances generally consists in that the double bonds contained in these substances are at least partially subjected to addition reactions and / or oxidation reactions. Frequently carried out modifications consist, for example, in the addition of sulfites, sulfonic acid groups being introduced into the fatty substance, or in air oxidation, with oxygen functions be introduced and some oligomerizations also occur. However, (partial) saponification of the fatty substances, transesterification and the like modification reactions are also possible.

The aim of these chemical modifications is to optimally adapt the application-related properties of the greasing substances, such as, for example, hydrophilicity, hydrophobicity, solubility, dispersibility, penetration and anchoring properties, special uses or the requirements of the users.

In practice, modification by partial sulfite addition (introduction of sulfonic acid groups) and partial oxidation are of particular importance. The combination of at least these modification measures can influence a number of valuable application properties, in particular the hydrophilicity, the penetration capacity and the anchoring properties.

The present invention relates to new leather treatment compositions for the production of leathers with low volatile constituents, in particular for high-quality car upholstery leather, a process for the production of these compositions and their use in the production of low-fogging leather. Car upholstery leather has to meet certain criteria. On the one hand, the softness is essential, on the other hand the fastness to light and heat and finally the so-called fogging behavior. DIN 75201 defines fogging as the condensation of evaporated volatile components from the vehicle interior on the glass panes, especially on the windshield. The same standard also describes a gravimetric and a reflectometric method for characterizing the fogging behavior of leather.

EP 498634 A2 recommends special polymers for the production of so-called low fogging leathers, the aqueous dispersions being essentially free of organic solvents and containing an amphiphilic copolymer which consists of a predominant proportion of at least one hydrophobic monomer and a small proportion of at least one hydrophilic monomer. Treatment of the leather with these dispersions leads to good results in a gravimetric test according to DIN 75201. Reflectometric studies have not been disclosed.

These amphiphilic copolymers are preferably prepared in an aqueous emulsion polymerization. However, due to the different hydrophilicity of the monomers to be used, this naturally results in problems with the copolymerization behavior, which in extreme cases can lead to the monomers in undesirably form homopolymers for themselves. Another consequence of the inherently unfavorable solution ratios is that an expensive post-processing is necessary to destroy residual monomers. In order to achieve good emulsion stability, it is also necessary to add a sufficient amount of an emulsifier (lauryl sulfate was used in the examples given), which can lead to wastewater problems in leather processing.

EP 466 392 B1 describes a process for the preparation of polymers which contain both pendant hydrophobic groups and pendant alkoxylated groups which are obtained by derivatizing polymers after the actual polymerization process using customary processes. For example, polymers are preferably produced from simple monomers such as acrylamide and / or acrylic acid by conventional polymerization and then derivatized with a mixture of primary or hydrophobic amines or primary or secondary alkoxylated amines. The polymers described are used as thickeners and soil release agents.

WO 98/10103 describes a further process for the preparation of polymeric fatliquoring agents by polymerizing acrylic acid and / or methacrylic acid and / or their acid chlorides and / or their anhydrides with further copolymerizable water-soluble monomers and with copolymerizable water-insoluble monomers and subsequent reaction of the polymers with amines. According to DIN 75201 B (gravimetry), fogging values of 1.2 mg and 1.5 mg are found for leather that has been treated with the listed sample products; those with the comparative products (Magnopal ^® SOF, low-fogging

Polymer fat and Chromopol "LFC, low-fogging fat based on fish oils, both Stockhausen GmbH & Co. KG) treated leather achieve fogging values of 3.9 mg and 3.5 mg. The reflectometric values according to DIN 75201 A of the sample products are 51% and 55%, respectively, of the comparison products 34% and 40%.

US Pat. No. 5,348,807 also describes a process in which selected amphiphilic copolymers, consisting of a predominant proportion of hydrophobic and a smaller proportion of hydrophilic assemblies, as low-solvent, low-fogging Fatliquor can be used. To produce these polymers, the hydrophilic monomers used are acid-substituted or basic-substituted esters of unsaturated carboxylic acids, such as, for example, sulfatoethyl (meth) acrylate or dimethylaminoethyl (meth) acrylate: longer-chain alkenes or (meth) acrylic acid ( C -C ₁₂ ) alkyl esters or vinyl esters of C ₄ to C ₁₂ carboxylic acids. The substances give good fogging values; however, there is no information about bath consumption.

In this process too, the amphiphilic copolymers are preferably prepared by aqueous emulsion polymerization. However, due to the different hydrophilicity of the monomers to be used, this again leads to the production problems already mentioned in the discussion of EP-A-498634.

EP 0 753 585 B1 describes a process for producing low-fogging furniture leather, in which specially treated native oils, which have less than 3% of fatty acid components with less than 16 carbon atoms, act as the basis for fatliquoring agents. Native oils used are soybean, lard, safflower and sunflower oil. The said native oils are first distilled to remove the undesirable low molecular weight constituents and then reacted with hydrogen sulfite or hydrogen sulfate in order to improve the emulsifiability. Then the (partially) functionalized oils are emulsified and applied.

For ecological reasons, there is a growing demand for high-fat lipids. In order to meet this requirement, the fat must be absorbed as completely as possible by the collagen. In wet blue semi-finished products, the mostly anionic fatliquor is fixed by the chromium (III) cations. At wet wliite

Semi-finished products that are manufactured without cationic metal salts lack these binding sites. This leads to the fact that when using commercial greasing agents which are produced according to the prior art, the bath consumption is poor, ie the remaining liquor has a high COD value. _, According to the prior art, chemical modification of the fatliquor improves the bath consumption, which is usually done by depositing the fatliquoring components on the leather surface. As a result, the connections are poorly fixed in the leather and leather with high fogging values according to DIN 75201 is thus obtained. It is common to all of the prior art processes described above that either polymers or fatliquors based on chemically modified native oils are used and that these products are special, relatively narrow classes of substances. In addition, all of these processes completely ignore the environmental aspect with regard to the best possible fleet consumption.

An object of the present invention was to find a process for greasing leather or to develop a greasing agent which no longer has these disadvantages of the prior art. Surprisingly, it has been found that the disadvantages of the prior art can be overcome by using a new emulsifier composition or a fatliquor mixture of the composition given below.

Particularly advantageous effects result if the emulsifiers according to the invention are used in combination with specially modified fatliquoring agents described below.

The present invention relates to an emulsifier composition comprising three components A, B and C, component A being a C ₆ to C ₁ alkanol alkoxylated with 4 to 12 AO units, or a mixture of several such alkanols, component B being a 15 up to 40 AO units alkoxylated C ₁₂ -C ₂₄ fatty alcohol mixture and component C is a C ₁₂ to C ₂₄ fatty alcohol mixture alkoxylated with 50 to 100 AO units.

The AO units are expediently alkylene oxide units with 2 to 4, preferably with 2 to 3, carbon atoms. The building blocks of the polyether chains can all be the same or different and - if they are different - they can be arranged randomly or in blocks.

The proportions by weight of the components in the emulsifier composition are for component A: 20 to 60, preferably 25 to 50, in particular 28 to 40% by weight, for component B 20 to 70, preferably 25 to 60, in particular 30 to 45% by weight and for component C 10 up to 50, preferably 15 to 40, in particular 22 to 32% by weight of the total weight of the composition.

The alkoxylated alkanol or the alkoxylated alkanol mixture of component A preferably has an average of 8 to 12 carbon atoms, in particular 10 carbon atoms, and the alkoxylated alkanol mixture of components B and C has an average of 14 to 20 carbon atoms, in particular 16 to 18 carbon atoms -Atoms, on.

Also preferred are emulsifier compositions in which component A has 5 to 10 AO units, component B has 20 to 30 AO units and component C has 50 to 100 AO units.

Alkoxylated longer-chain and long-chain alcohols are known. They are obtained by reacting the corresponding alkanols or alkanol mixtures, as are present in the fatty alcohols, with the desired molar amounts of the alkylene oxides, such as ethylene oxide, propylene oxide or butylene oxide. Depending on how the alkylene oxides are metered into the batches, statistical or block-like polyether chains can be produced in a targeted manner. The reaction can be catalyzed by small amounts of water and / or alkali.

The emulsifier compositions according to the invention are prepared by mixing the components with stirring and optionally with gentle heating. If desired, they can be converted into solutions by adding water, which, depending on the wishes of the users, expediently have a solids content of about 40 to 80% by weight. Of course, other concentrations of the emulsifier compositions according to the invention can also be provided for special purposes.

The invention further relates to oiling agents for oiling leather comprising one or more, optionally modified, native oiling components and / or optionally a synthetic lipid component, in particular a polymeric lipid component, emulsifiers and optionally diluents, especially water, which are characterized in that they contain one of the emulsifier compositions described above.

As a rule, the fatliquoring agents according to the invention contain 2 to 20, preferably 5 to 15% by weight of the emulsifier composition according to the invention.

Particular advantages result when using fatliquoring agents in which the emulsifier composition according to the invention is combined with a fatliquoring component which comprises at least one neutral oil chemically modified by oxidation and sulfitation, a relatively high degree of oxidation being combined with a relatively low degree of sulfitization.

In principle, all usual native oils with a sufficient content of double bonds can be considered as neutral oils. Expediently, fat substances of vegetable or animal origin, in particular glycerides of natural fatty acids with a sufficient proportion of unsaturated acids, serve as native fat components.

Well-suited fatty substances are vegetable and animal fats and oils with an iodine number of approx. 10 to approx. 200. In the lower section of this area you can find e.g. Stearin and tung oil, in the upper section especially the fish oils and the Chaulmoogra oil. The selection of fatty substances depends, among other things, on the special purpose for which the mixture according to the invention is to be used. For example, prohibit the use of fish oils in the manufacture of fine leather goods because of the smell of these fats.

Fatty substances with iodine numbers of approximately 30 to approximately 120, in particular 40 to 85, are preferred. Examples of particularly preferred fatty substances are sebum types of different origins, bone oil, nitro oil, claw oil, lard oil, triolein, rapeseed oil, olive oil, nut oil and castor oil.

The sulfitation or oxidation products of the mono- or polyunsaturated fatty substances are formed by the reaction of the olefinic double bonds present in the fatty substances with the sulfitation and / or oxidation reagents. All double bonds present in the fatty substances or only some of them can react.

Fish and rapeseed oil, for example, are particularly favorable for use in accordance with the invention. A relatively high degree of oxidation in the sense of this invention is present when Δd, the difference in the specific weights of the oil or fat before and after the oxidation, is in the range from 0.01 to 0.1, preferably from 0.03 to 0.05 ,

A relatively low degree of sulfitation within the meaning of this invention is when the neutral oil has been reacted with 2 to 8%, preferably 3 to 5%, of its weight as a sulfite, calculated as sodium bisulfite (Na ₂ S ₂ O ₅ ).

Thus, particularly preferred fatliquoring agents according to the invention include one or more, optionally modified, native fatliquoring components and / or optionally a synthetic, for example a polymeric, fatliquoring component, emulsifiers and optionally diluents, in particular water, which are characterized in that they are one of the emulsifier compositions described above contain and the fatty components comprise a relatively highly oxidized, relatively low sulfited neutral oil.

As a rule, the particularly preferred fatliquoring agents according to the invention contain 80 to 98% by weight, preferably 85 to 95% by weight of fatliquoring components, 20 to 80% by weight, in particular 25 to 75% by weight of the fatliquoring components to be used relatively according to the invention are highly oxidized, relatively low sulfited neutral oils.

The fatliquoring agents according to the invention can also be provided undiluted or, depending on the wishes of the users, in the form of aqueous emulsions, advantageously with solids contents of 40 to 80% by weight.

The components of the preferred fatliquoring agents according to the invention, namely the emulsifier mixtures according to the invention and the relatively highly oxidized, relatively low sulfitated neutral oils, can of course also be added separately to the fatliquoring liquors in any order. The invention thus also relates to a process for oiling leather and hides by treatment with aqueous liquors which contain oiling agents and emulsifiers, which is characterized in that 10 to 90% by weight, preferably 25-75% by weight, of the oiling agents relative highly oxidized, relatively low are sulfited neutral oils and the liquor contains 1 to 10% by weight, preferably 2.5 to 7.5% by weight, of an emulsifier composition according to the invention.

The invention further relates to the use of the described emulsifier composition according to the invention, preferably in combination with relatively highly oxidized, relatively low sulfited neutral oils, in leather production, and the use of the emulsifier composition according to the invention preferably in combination with relatively highly oxidized, relatively low sulfited neutral oils for the production of fat liquors.

The use of the fatliquoring agents according to the invention serves to soften the leather, to increase its fullness and strength and to protect it against moisture, dirt and chemical influences from outside.

The presence of the emulsifier compositions according to the invention in the leather treatment liquors leads to very good bath consumption and thus to particularly low COD values with at the same time good anchoring of the fatliquor inside the leather and thus to low fogging values.

The following embodiments illustrate the invention.

Example 1, Production of an Emulsifier Preparation According to the Invention.

Be in a stirred kettle

180 kg of a C ₁₀ alkanol ethoxylated with 7 AEO units,

200 kg of a C ₁₆ -C ₁₈ fatty alcohol ethoxylated with 25 AEO units and

140 kg of a C ₁₆ -C ₁₈ fatty alcohol ethoxylated with 80 AEO units are stirred at 60 to 80 ° C. until completely homogenized.

The preparation obtained is soluble in water. It can be used either directly or in the form of an aqueous dilution (40-80% by weight is expedient) in leather production. Example 2, leather production without greasing.

100 parts by weight of chrome cowhide with a fold thickness of 2.0 to 2.2 mm are placed in 100 parts by weight of water at 40 ° C. and adjusted to a pH of 4.5 by adding sodium formate and sodium hydrogen carbonate. The leather is drummed at 40 ° C for 60 minutes in a barrel and then washed with 200 parts by weight of water.

100 parts by weight of water at 40 ° C. and 2 parts by weight of commercially available polymer tanning agent, 4 parts by weight of commercially available resin tanning agent and 4 parts by weight of commercially available mimosa are then added. You roll for 90 minutes and then dye the leather in the same liquor with 1 part by weight of a commercially available leather dye. The liquor is drained, 100 parts by weight of water are added and the leather is drummed for 60 minutes at 50 ° C. as usual.

The liquor is then adjusted to a pH of 3.5 to 3.8 using formic acid, the leather briefly rinsed cold and processed further, as is customary. Then a 20 ml sample is taken from the liquor to determine the COD value.

The leather obtained is well colored, of little fullness and hard.

The COD value is determined in the sample taken from the liquor (in accordance with DIN 38409-H43-1) and the fogging value in the leather obtained in accordance with DIN 75201B. The results obtained in these tests are summarized in Table 2.

Example 3, leather production with greasing, conventional.

100 parts by weight of water at 40 ° C. and 2 parts by weight of commercially available polymer tanning agent, 4 parts by weight of commercially available resin tanning agent and 4 parts by weight of commercially available mimosa are then added. You roll for 90 minutes and then dye the leather in the same liquor with 1 part by weight of a commercially available leather dye. The liquor is then drained off and 100 parts by weight of water and either 4 parts by weight of a commercially available lecithin licker or 6 parts by weight of one of the fatliquor mixtures A and B of the composition given in Table 1 are added to the leather, and the leather in this, as usual, at 50 ° C. for 60 minutes Fleet milled. The liquor is then adjusted to a pH of 3.5 to 3.8 using formic acid, the leather briefly rinsed cold and processed further, as is customary. Then a 20 ml sample is taken from the liquor to determine the COD value. A leather is obtained with a very good color, good firm grain, with good fullness and medium softness. The leather surface has a slim handle.

The COD value is determined in the sample taken from the liquor after the end of the greasing period in accordance with DIN 38409-H43-1 and the fog value in the leather obtained in accordance with DIN 75201B. The results obtained in these tests are summarized in Table 2.

Table 1: Composition of Licker A and B

* The extent of air oxidation is characterized by the increase Δ d of the specific weight [g / ml].

Example 4, leather production with greasing, according to the invention.

Example 3 is repeated under the same conditions and using the same tanning agents and the Licker mixtures A and B used there. It will however, 5.2 parts by weight of the emulsifier preparation prepared according to Example 1 were added to the liquor mixtures in the liquor. The greasing and further treatment of the leather is continued exactly as described in Example 3. ^•

The COD values of the liquor sample and the fogging values of the leather produced are then determined as in Examples 2 and 3.

The leather produced has the same quality as that obtained in Example 3.

The measured values for COD and fogging obtained in Examples 2 to 4 are summarized in Table 2.

Table 2

* Gravimetric determination

You can see an enormous improvement in the bath consumption (decrease in the COD value to approx. 25%) with a simultaneous decrease or constant in the foggmg values. This is remarkable because normally a reduction in the COD value increases the fogging values.

Claims

claims

1. Emulsifier composition comprising three components A, B and C, component A being a C ₆ to C ₄ alkanol alkoxylated with 4 to 12 AO units or a mixture of several such alkanols, component B being an alkoxylated having 15 to 30 AO units ₂ -C ₂ fatty alcohol mixture and component C is a C ₁₂ to C ₂₄ fatty alcohol mixture alkoxylated with 40 to 100 AO units.

2. Emulsifier composition according to claim 1, characterized in that the proportion by weight of component A is 20 to 60% by weight, component B is 20 to 70% by weight and component C is 10 to 50% by weight of the total weight of the preparation ,

3. Emulsifier composition according to claims 1 and 2, characterized in that component A is a C ₈ to ₂ alkanol mixture alkoxylated with 4 to 12 AO units, component B is a C ₄ -C ₂₀ fatty alcohol mixture alkoxylated with 15 to 30 AO units and component C is a C ₁ to C ₂₀ alkoxylated with 40 to 100 AO units

Is a fatty alcohol mixture.

4. Fatliquor for fatliquoring leather comprising one or more, optionally modified, native fatliquoring substances and optionally synthetic fatliquors, emulsifiers and optionally diluents, in particular Water, characterized in that it contains an emulsifier composition of claims 1 to 3.

5. Fatliquor according to claim 4, characterized in that the fatliquoring components are a relatively highly oxidized, relatively low sulfitized

Include neutral oil.

6. Use of the emulsifier composition of claims 1 to 3 in leather production.

7. Use of the emulsifier composition of claims 1 to 3 for the production of fatliquoring agents.

8. Use of the emulsifier composition of claims 1 to 3 in combination with relatively highly oxidized, relatively low sulfited neutral oils, in leather production.

9. Use of the emulsifier composition of claims 1 to 3 in combination with relatively highly oxidized, relatively low sulfited neutral oils, for the production of fatliquoring agents.

10. A process for oiling leather and skins by treatment with aqueous liquors which contain oiling agents and emulsifiers, characterized in that 10 to 90% by weight, preferably 25-75% by weight of the oiling agent, are relatively highly oxidized, relatively low sulfitized Are neutral oils and the liquor contains 1 to 10 wt .-%, preferably 2.5 to 7.5 wt .-% of an emulsifier composition of claims 1 to 3.