Novel yellowing-resistant leather fatliquor as well as preparation method and application thereof

Abstract

The invention discloses a novel yellowing-resistant leather fatliquor as well as a preparation method and application thereof. The novel yellowing-resistant leather greasing agent provided by the invention is prepared from the following raw materials: long-chain fatty alcohol polyoxypropylene ether, the long-chain fatty alcohol polyoxypropylene ether is used for preparing a sulfonated substance and an esterified substance, and then the sulfonated substance, the esterified substance, a nonionic emulsifier, mineral oil and water are compounded, so that the leather greasing agent with a relatively high yellowing-resistant grade can be obtained. The long-chain fatty alcohol polyoxypropylene ether can provide a good fat-liquoring soft structure basis from the aspect of molecules, meanwhile, the product molecules do not contain double bonds, and the long-chain fatty alcohol polyoxypropylene ether has high anti-oxidation stability and can enable leather to have excellent yellowing resistance when being used as a fat-liquoring material.

Description

Technical Field

[0001] The invention relates to the technical field of leather, in particular to a novel yellowing-resistant leather fatliquor and a preparation method and application thereof. Background Art

[0002] Fatliquor is one of the most widely used specialized chemicals in the leather industry. It can make leather products soft and elastic. Fatliquor mainly consists of emulsifier and emulsified components. According to the difference of each component, leather fatliquor products with different performances can be derived. The final fatliquor effect can give leathers of different styles. With the changes in the market, white leather and light-colored leather products are increasingly used in people's daily lives and are deeply loved by people. In order to maintain the color tone of white leather and light-colored leather products, it is necessary to improve the ability of the oil components in the fatliquor to resist damage from heat and light, that is, the yellowing resistance of the fatliquor product.

[0003] Among the patents that have been published in China, patents for leather fatliquors with yellowing resistance as an advantage have been reported. Lv Bin et al. disclosed a succinate sulfonated prickly ash seed oil / nano perovskite oxide composite yellowing-resistant fatliquor and its preparation method (Lv Bin, Guo Xu, Gao Dangge, et al. A succinate sulfonated prickly ash seed oil / nano perovskite oxide composite yellowing-resistant fatliquor and its preparation method [P]. Shaanxi Province: CN201910920739.7, 2021-08-17). The zirconium-aluminum dual-doped perovskite oxide cited in the invention has excellent ultraviolet absorption ability and certain tanning properties, which increases the absorption and binding of the fatliquor while making the leather have higher yellowing resistance. Zhang Yuehong et al. disclosed a yellowing-resistant titanium dioxide / fatty acid-based leather fatliquor and a preparation method thereof (Zhang Yuehong, Liu Chenyang, Ma Jianzhong. A yellowing-resistant titanium dioxide / fatty acid-based leather fatliquor and a preparation method thereof [P]. Shaanxi Province: CN202110797467.3, 2022-05-24). They introduced TiO2COOH UV shielding agent into the fatty acid-based fatliquor by a blending method, thereby solving the problem of easy aging and yellowing of leather after fatliquor. Huo Yueqing et al. disclosed a yellowing-resistant leather fatliquor with modified sulfonated oil as the main agent and a preparation method thereof (Huo Yueqing, Liu Xiaochen, Cao Shengti, et al. Yellowing-resistant leather fatliquor with modified sulfonated oil as the main agent and a preparation method thereof [P]. Shanxi Province: CN202311817349.X, 2024-04-05). They introduced polyoxyethylene (EO) groups into the modified sulfonated oil. The introduction of EO groups increased the molecular weight of the sulfonated oil, thereby reducing the active groups in the fatliquor at the same addition amount, thereby giving the fatliquor good yellowing resistance and reducing costs. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a novel yellowing-resistant leather fatliquor and its preparation method and application.

[0005] The present invention provides a novel yellowing-resistant leather fatliquor, the preparation raw materials of which include: long-chain fatty alcohol polyoxypropylene ether, the structural formula of which is as follows:

[0006]

[0007] In the above formula, R is a straight-chain C16-C18 straight-chain alkane, n is the degree of polymerization of propylene oxide, and n=5-10.

[0008] The present invention also provides a method for preparing the novel anti-yellowing leather fatliquor, comprising the following steps: mixing and stirring long-chain fatty alcohol polyoxypropylene ether sulfate, long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate, nonionic emulsifier and mineral oil at 50-60° C. for 30 minutes, adding water to a solid content of 50-60%, and stirring for another hour to obtain the novel anti-yellowing leather fatliquor;

[0009] Preferably, based on 100% solid content, the amount of the long-chain fatty alcohol polyoxypropylene ether sulfate is 20 to 30 parts;

[0010] Preferably, based on 100% solid content, the amount of the long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate is 30 to 40 parts;

[0011] Preferably, the nonionic emulsifier is used in an amount of 10 to 20 parts;

[0012] Preferably, the amount of the mineral oil is 20 to 30 parts.

[0013] The invention also provides application of the novel yellowing-resistant leather fatliquor in leather processing.

[0014] The present invention has the following beneficial effects:

[0015] The present invention provides a novel anti-yellowing leather fatliquor and a preparation method and application thereof. The novel anti-yellowing leather fatliquor provided by the present invention comprises: long-chain fatty alcohol polyoxypropylene ether. Long-chain fatty alcohol polyoxypropylene ether is used as the preparation raw material. Compared with conventional long-chain fatty alcohol polyoxyethylene ether, it contains a certain amount of methyl in the polyether side chain. The raw material has a very low freezing point and is in a liquid state at room temperature, so it is conducive to sulfonation reaction and esterification reaction; at the same time, due to the hydrophobicity of the polypropylene ether chain, it can not only provide good softness and oiliness to the sulfonate and esterify, but also keep the product in good flowability. At the same time, it does not contain double bonds in the molecule, has strong antioxidant stability, and can be used as a fatliquor material to make the leather have a higher yellowing resistance grade. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 Schematic diagram of the method for dividing the first layer of yellow cattle shaved blue wet leather. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0019] The following is a detailed description of a novel yellowing-resistant leather fatliquor provided by an embodiment of the present invention, and its preparation method and application.

[0020] In the first aspect, an embodiment of the present invention provides a novel yellowing-resistant leather fatliquor, wherein the raw materials for its preparation include: long-chain fatty alcohol polyoxypropylene ether, and the structural formula of the long-chain fatty alcohol polyoxypropylene ether is as follows:

[0021]

[0022] In the above formula, R is a straight-chain C16-C18 straight-chain alkane, n is the degree of polymerization of propylene oxide, and n=5-10.

[0023] The embodiment of the present invention provides a novel anti-yellowing leather fatliquor, and its preparation raw materials include: long-chain fatty alcohol polyoxypropylene ether, which is a hydrophobic material based on a long alkane chain and a polyoxypropylene (PO) group, does not contain a double bond in its molecule, has strong antioxidant properties, is an excellent fatliquor raw material, and can give leather a higher yellowing resistance grade. At the same time, due to the PO segment with -CH3 side chain characteristics, the solidification point of the long-chain fatty alcohol polyoxypropylene ether molecule can be significantly reduced, and it is the main component of the fatliquor, which can not only improve the softness and oiliness of the fatliquor to leather fibers, but also can increase the fluidity of the fatliquor product appearance, which is convenient for the use of the leather making process.

[0024] In some optional embodiments, the main components of the novel yellowing-resistant leather fatliquor include: long-chain fatty alcohol polyoxypropylene ether sulfate and long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate prepared using long-chain fatty alcohol polyoxypropylene ether, as well as nonionic emulsifier, mineral oil and water.

[0025] In some optional embodiments, the long-chain fatty alcohol polyoxypropylene ether sulfate is obtained by subjecting the long-chain fatty alcohol polyoxypropylene ether to a sulfonation reaction and then a neutralization reaction, and the long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate is obtained by subjecting the long-chain fatty alcohol polyoxypropylene ether to a succinic acid sulfonation reaction.

[0026] In some optional embodiments, the long-chain fatty alcohol polyoxypropylene ether sulfate is prepared by the following method: after the long-chain fatty alcohol polyoxypropylene ether is subjected to a gas-liquid sulfonation reaction with a SO3 component through a membrane sulfonation reactor, the long-chain fatty alcohol polyoxypropylene ether is subjected to a neutralization reaction to obtain the long-chain fatty alcohol polyoxypropylene ether sulfate;

[0027] Preferably, the structural formula of long-chain fatty alcohol polyoxypropylene ether is as follows:

[0028]

[0029] In the above formula, R is a straight-chain C16-C18 straight-chain alkane, n is the degree of polymerization of propylene oxide, n=5-10;

[0030] Preferably, the temperature of the long-chain fatty alcohol polyoxypropylene ether entering the membrane sulfonation reactor is 10 to 50° C.;

[0031] Preferably, the jacket water bath circulation temperature of the membrane sulfonation reactor is 30 to 80°C;

[0032] Preferably, the SO3 component is a mixed gas of SO3 / air, wherein the volume percentage of SO3 in the mixed gas is 3% to 7%, and the temperature of the SO3 component entering the membrane sulfonation reactor is 40 to 60°C;

[0033] Preferably, the molar ratio of the SO3 component to the long-chain fatty alcohol polyoxypropylene ether is 0.80-1.10:1, and the structural formula of the long-chain fatty alcohol polyoxypropylene ether sulfate obtained by the gas-liquid sulfonation reaction is as follows:

[0034]

[0035] Preferably, the alkaline solution used for the neutralization reaction includes one of a NaOH solution with a mass concentration of 30%, a KOH solution with a mass concentration of 50%, and an NH4OH solution with a mass concentration of 28%, wherein: the neutralization reaction temperature is 40-60°C, the time is 0.5-2h, the pH is 7.5-9.0, and the long-chain fatty alcohol polyoxypropylene ether sulfate obtained by the reaction of the long-chain fatty alcohol polyoxypropylene ether sulfate with the alkaline solution has the following structural formula:

[0036]

[0037] In the above formula, M is at least one of Na, K, and NH4;

[0038] Preferably, the long-chain fatty alcohol polyoxypropylene ether sulfate needs to be decolorized, and the decolorization is carried out under weakly alkaline conditions, wherein: the pH of the decolorization is 8.0-8.5, the temperature is 50-70°C, the time is 1-3h, and the decolorizing agent includes any one of hydrogen peroxide, thiourea dioxide, and sodium bisulfite.

[0039] The embodiment of the present invention provides a novel anti-yellowing leather fatliquor, comprising the following components: long-chain fatty alcohol polyoxypropylene ether sulfate, long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate, nonionic emulsifier and mineral oil. The preparation of long-chain fatty alcohol polyoxypropylene ether sulfate comprises the following steps: long-chain fatty alcohol polyoxypropylene ether enters from the top of the membrane sulfonation reactor, and forms a thin liquid film along the inner wall of the sulfonation tube. At the same time, the SO3-containing component is filtered through a filter according to a ratio and enters the top of the membrane sulfonation reactor. The two flow down in parallel, and the SO3 component quickly completes the gas-liquid reaction on the liquid film. The jacket of the membrane sulfonation reactor is connected to circulating water to ensure a suitable reaction temperature. The sulfonic acid product flows out from the lower part of the sulfonation tube and is neutralized to weak alkalinity with an alkaline solution, and then decolorized to obtain the long-chain fatty alcohol polyoxypropylene ether sulfate product.

[0040] In the above process, the preparation of long-chain fatty alcohol polyoxypropylene ether sulfate does not adopt sulfonyl chloride sulfonation, but adopts SO3 sulfonation process. The process control can realize continuous automatic control, does not use dangerous chlorine raw materials, does not produce a large amount of waste hydrogen chloride gas, and does not contain organic chlorine in the product. The preparation reaction adopts the gas phase SO3 membrane sulfonation reaction principle, the contact area between the reactants is large, and the reaction can be completed by cyclic action under high concentration SO3. The reaction efficiency is high, it is an "atom economic reaction", does not produce a large amount of three wastes, and is a synthetic method actively advocated in green industrial production.

[0041] In some optional embodiments, the long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate is prepared by the following method: esterifying the long-chain fatty alcohol polyoxypropylene ether with maleic anhydride to obtain the long-chain fatty alcohol polyoxypropylene ether succinic acid monoester; then sulfiting the long-chain fatty alcohol polyoxypropylene ether succinic acid monoester with sodium sulfite to obtain the long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate;

[0042] Preferably, the molar ratio of the long-chain fatty alcohol polyoxypropylene ether to maleic anhydride is 1-1.2:1, the esterification reaction temperature is 90-105° C., and the esterification reaction time is 2.5-3.5 h.

[0043] Preferably, the molar ratio of long-chain fatty alcohol polyoxypropylene ether succinic acid monoester to sodium sulfite is 1-1.2:1, the sulfitation reaction temperature is 75-85° C., and the sulfitation reaction time is 2.5-3.5 h.

[0044] In some optional embodiments, the nonionic emulsifier includes at least one of O-15 and O-20, and the mineral oil includes at least one of 32# white oil and 36# white oil.

[0045] In a second aspect, an embodiment of the present invention provides a method for preparing the above-mentioned novel anti-yellowing leather fatliquor, comprising the following steps: mixing long-chain fatty alcohol polyoxypropylene ether sulfate, long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate, non-ionic emulsifier and mineral oil at 50-60° C. for 30 minutes, adding water to a solid content of 50-60%, and stirring for another hour to obtain a novel anti-yellowing leather fatliquor;

[0046] Preferably, based on 100% solid content, the amount of long-chain fatty alcohol polyoxypropylene ether sulfate is 20 to 30 parts;

[0047] Preferably, based on 100% content, the amount of long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate is 30 to 40 parts;

[0048] Preferably, the amount of nonionic emulsifier is 10 to 20 parts;

[0049] Preferably, the amount of mineral oil is 20 to 30 parts;

[0050] In some optional implementations, the pH value of the new anti-yellowing leather fatliquor emulsion with a mass percentage of 10% is 6.0-7.0; the viscosity of the new anti-yellowing leather fatliquor emulsion at 40° C. is 0.2-0.4 Pa·s.

[0051] In a third aspect, an embodiment of the present invention provides an application of the novel yellowing-resistant leather fatliquor mentioned above or the novel yellowing-resistant leather fatliquor prepared by the above preparation method in leather processing.

[0052] The present invention will be further described below in conjunction with the embodiments.

[0053] The preparation method of long-chain fatty alcohol polyoxypropylene ether sulfate is as follows:

[0054] Test Example 1:

[0055] (1) Sulfonation reaction

[0056] Take 1kg of long-chain fatty alcohol polyoxypropylene ether RO (CH (CH3) CH2) n OH (n=5, R is a straight-chain C16~C18 straight-chain alkane), the feed temperature is set at 20°C, the SO3 component is prepared by sulfur combustion method, and the temperature of the SO3 / air mixed gas is 50°C, the volume percentage is 4%, the molar ratio of the SO3 component to the long-chain fatty alcohol polyoxypropylene ether is 1.05:1, the long-chain fatty alcohol polyoxypropylene ether and the SO3 component enter the sulfonator from the top of the sulfonator to undergo sulfonation reaction, the water bath temperature of the sulfonation tube jacket is 65°C, the long-chain fatty alcohol polyoxypropylene ether sulfate is taken out, and then neutralization and decolorization reactions are carried out.

[0057] (2) Neutralization reaction

[0058] Long-chain fatty alcohol polyoxypropylene ether sulfate was neutralized with 30% NaOH solution (the dosage was 30% of the sulfate) at 50° C. The neutralization time was 1 hour, and the pH was adjusted to 8.5.

[0059] (3) Decolorization reaction

[0060] 2% (in terms of sulfate) of hydrogen peroxide was added to the neutralized long-chain fatty alcohol polyoxypropylene ether sulfate solution, the temperature was controlled at 55°C, pH 8.5, the reaction was carried out for 1.5 hours, and then citric acid monohydrate was added to adjust the pH (10%) of the final product to 7.5. The solid content of the product was 75%, and the sulfonation degree of the long-chain fatty alcohol polyoxypropylene ether sulfate was detected to be 60% (the sulfonation degree of the product was determined in accordance with the national standard GB / T 5173-2018).

[0061] Test Example 2:

[0062] (1) Sulfonation reaction

[0063] Take 2kg of long-chain fatty alcohol polyoxypropylene ether RO (CH (CH3) CH2) nOH (n=8, R is a straight-chain C16~C18 straight-chain alkane), the feed temperature is set at 35°C, the SO3 component is prepared by sulfur combustion method, and the temperature of the SO3 / air mixed gas is 60°C, the volume percentage is 5%, the molar ratio of the SO3 component to the long-chain fatty alcohol polyoxypropylene ether is 1:1, the long-chain fatty alcohol polyoxypropylene ether and SO3 / process air mixed gas enter the sulfonator from the top of the sulfonator to undergo sulfonation reaction, the water bath temperature of the sulfonation tube jacket is 45°C, the long-chain fatty alcohol polyoxypropylene ether sulfate is taken out, and then neutralization and decolorization reactions are carried out.

[0064] (2) Neutralization reaction

[0065] Long-chain fatty alcohol polyoxypropylene ether sulfate was neutralized with 50% KOH solution (25% of sulfate) at 40°C for 2 hours, and the pH was adjusted to 9.0.

[0066] (3) Decolorization reaction

[0067] Add 0.5% (in terms of sulfate) of thiourea dioxide to the neutralized long-chain fatty alcohol polyoxypropylene ether sulfate solution, control the temperature at 60°C and pH at 8.2, and react for 3 hours. Then, add citric acid monohydrate to adjust the pH (10%) of the final product to 7.5. The solid content of the product is 75%. The sulfonation degree of the long-chain fatty alcohol polyoxypropylene ether sulfate is 71%.

[0068] Test Example 3:

[0069] (1) Sulfonation reaction

[0070] Take 1.5kg of long-chain fatty alcohol polyoxypropylene ether RO (CH (CH3) CH2) n OH (n=10, R is a straight-chain C16~C18 straight-chain alkane), the feed temperature is 45°C, the SO3 component is prepared by liquid SO3 evaporation method, and the temperature of the SO3 / air mixed gas is 45°C, the volume percentage is 7%, the molar ratio of the SO3 component to the long-chain fatty alcohol polyoxypropylene ether is 0.85:1, the long-chain fatty alcohol polyoxypropylene ether and the SO3 component enter the sulfonator from the top of the sulfonator to undergo sulfonation reaction, the water bath temperature of the sulfonation tube jacket is 55°C, the long-chain fatty alcohol polyoxypropylene ether sulfate is taken out, and then neutralization and decolorization reactions are carried out.

[0071] (2) Neutralization reaction

[0072] Long-chain fatty alcohol polyoxypropylene ether sulfate was neutralized with 28% NH4OH solution (30% of the sulfate) at 50°C for 1.5 h, and the pH was adjusted to 8.0.

[0073] (3) Decolorization reaction

[0074] Add 1% (calculated as sulfate) of sodium bisulfite to the neutralized long-chain fatty alcohol polyoxypropylene ether sulfate solution, control the temperature at 65°C and pH at 8.5, react for 2 hours, then add citric acid monohydrate to adjust the pH (10%) of the final product to 7.5, the solid content of the product is 75%, and the sulfonation degree of the long-chain fatty alcohol polyoxypropylene ether sulfate is 64%.

[0075] The preparation method of long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate is as follows:

[0076] Test example 4:

[0077] (1) Esterification reaction

[0078] In a 1000 mL four-necked flask with stirring, add 254 g of long-chain fatty alcohol polyoxypropylene ether RO (CH (CH3) CH2) n OH (n=5, R is a straight-chain C16-C18 straight-chain alkane) and 49g of maleic anhydride (the molar ratio of long-chain fatty alcohol polyoxypropylene ether to maleic anhydride is controlled to be 1.1:1), the temperature is controlled to be 95°C, and the reaction is carried out for 3h to obtain long-chain fatty alcohol polyoxypropylene ether succinic acid monoester.

[0079] (2) Sulfitation reaction

[0080] First, prepare a sodium sulfite solution: dissolve 57.3 g of sodium sulfite in 210 g of water in a 500 mL four-necked flask with stirring (control the molar ratio of esterification product to sodium sulfite to be 1.1:1), stir at 33°C for 20 min, then adjust the solution pH to 7.5 with monoethanolamine, stir at 33°C for 10 min and set aside.

[0081] Slowly add the sodium sulfite solution into a four-necked flask containing long-chain fatty alcohol polyoxypropylene ether succinic acid monoester, control the temperature to 80°C, and add the solution for 30 minutes. After the addition is completed, react for 3 hours, add water to a solid content of 60% and stir evenly to obtain long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate.

[0082] Test Example 5:

[0083] (1) Esterification reaction

[0084] In a 1000 mL four-necked flask with stirring, 348.5 g of long-chain fatty alcohol polyoxypropylene ether RO (CH (CH3) CH2) was added. n OH (n=8, R is a straight-chain C16-C18 straight-chain alkane) and 49g of maleic anhydride (the molar ratio of long-chain fatty alcohol polyoxypropylene ether to maleic anhydride is controlled to be 1.15:1), the temperature is controlled to be 105°C, and the reaction is carried out for 2.5h to obtain long-chain fatty alcohol polyoxypropylene ether succinic acid monoester.

[0085] (2) Sulfitation reaction

[0086] First, prepare a sodium sulfite solution: dissolve 63 g of sodium sulfite in 285 g of water in a 500 mL four-necked flask with stirring (control the molar ratio of esterification product to sodium sulfite to be 1:1), stir at 33°C for 20 min, then adjust the solution pH to 7.5 with monoethanolamine, stir at 33°C for 10 min and set aside.

[0087] Slowly add the sodium sulfite solution into a four-necked flask containing long-chain fatty alcohol polyoxypropylene ether succinic acid monoester, control the temperature to 75°C, and add the solution for 30 minutes. After the addition is completed, react for 3.5 hours, add water to a solid content of 60% and stir evenly to obtain long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate.

[0088] Test Example 6:

[0089] (1) Esterification reaction

[0090] In a 1000 mL four-necked flask with stirring, add 351 g of long-chain fatty alcohol polyoxypropylene ether RO (CH (CH3) CH2) n OH (n=10, R is a straight-chain C16-C18 straight-chain alkane) and 49g of maleic anhydride (the molar ratio of long-chain fatty alcohol polyoxypropylene ether to maleic anhydride is controlled to be 1:1), the temperature is controlled to be 90°C, and the reaction is carried out for 3.5h to obtain long-chain fatty alcohol polyoxypropylene ether succinic acid monoester.

[0091] (2) Sulfitation reaction

[0092] First, prepare a sodium sulfite solution: dissolve 54.8 g of sodium sulfite in 200 g of water in a 500 mL four-necked flask with stirring (control the molar ratio of esterification product to sodium sulfite to be 1.15:1), stir at 33°C for 20 min, then adjust the solution pH to 7.5 with monoethanolamine, stir at 33°C for 10 min and set aside.

[0093] Slowly add the sodium sulfite solution into a four-necked flask containing long-chain fatty alcohol polyoxypropylene ether succinic acid monoester, control the temperature to 85°C, and add the solution for 30 minutes. After the addition is completed, react for 2.5 hours, add water to a solid content of 60% and stir evenly to obtain long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate.

[0094] The preparation method of the new type of yellowing-resistant fatliquor is as follows:

[0095] Embodiment 1:

[0096] In a mixing reactor, 20 parts of the long-chain fatty alcohol polyoxypropylene ether (n=5) sulfate prepared in Test Example 1, 40 parts of the long-chain fatty alcohol polyoxypropylene ether (n=8) succinic acid monoester sulfonate prepared in Test Example 5, 15 parts of O-15 emulsifier, and 25 parts of 32# white oil (all by mass fraction) were added, and the mixing temperature was controlled to be 50°C. After stirring for 30 minutes, water was added to the solid content of 50%, and then stirred for 1 hour. After uniform mixing, a new type of yellowing-resistant fatliquor was obtained, which was a yellow transparent liquid in appearance, and the viscosity at 40°C was 0.31 Pa·s. The pH of the new type of yellowing-resistant fatliquor emulsion with a mass percentage of 10% was 6.4.

[0097] Embodiment 2:

[0098] In the reaction kettle, 30 parts of the long-chain fatty alcohol polyoxypropylene ether (n=10) sulfate prepared in Test Example 3, 35 parts of the long-chain fatty alcohol polyoxypropylene ether (n=5) succinic acid monoester sulfonate prepared in Test Example 4, 12 parts of O-20 emulsifier, and 23 parts of 36# white oil (all by mass fraction) were added, and the mixing temperature was controlled to be 55°C. After stirring for 30 minutes, water was added to the solid content of 55%, and then stirred for 1 hour. After uniform mixing, a new type of yellowing-resistant fatliquor was obtained, which was a yellow transparent liquid in appearance, and the viscosity at 40°C was 0.34 Pa·s. The pH of the new type of yellowing-resistant fatliquor emulsion with a mass percentage of 10% was 6.5.

[0099] Embodiment 3:

[0100] In the reaction kettle, 22 parts of the long-chain fatty alcohol polyoxypropylene ether (n=8) sulfate prepared in Test Example 2, 32 parts of the long-chain fatty alcohol polyoxypropylene ether (n=10) succinic acid monoester sulfonate prepared in Test Example 6, 20 parts of O-15 emulsifier, and 26 parts of 36# white oil (all of the above are calculated by mass fraction) are added, and the mixing temperature is controlled to be 60°C. After stirring for 30 minutes, water is added to the solid content of 60%, and then stirred for 1 hour. After uniform mixing, the new anti-yellowing fatliquor is obtained, which has a yellow transparent liquid appearance, a viscosity of 0.35 Pa·s at 40°C, and a pH of 10% of the new anti-yellowing fatliquor emulsion is 6.8.

[0101] Embodiment 4:

[0102] In the reaction kettle, 25 parts of the long-chain fatty alcohol polyoxypropylene ether (n=5) sulfate prepared in Test Example 1, 38 parts of the long-chain fatty alcohol polyoxypropylene ether (n=10) succinic acid monoester sulfonate prepared in Test Example 6, 17 parts of O-20 emulsifier, and 20 parts of 32# white oil (all of the above are calculated by mass fraction) are added, and the mixing temperature is controlled to be 60°C. After stirring for 30 minutes, water is added to the solid content of 55%, and then stirred for 1 hour. After uniform mixing, the new anti-yellowing fatliquor is obtained, which has a yellow transparent liquid appearance, a viscosity of 0.27 Pa·s at 40°C, and a pH of 10% of the new anti-yellowing fatliquor emulsion is 6.7.

[0103] Comparative Example 1

[0104] HFK-N fatliquor was used, and the manufacturer was Brother Technology Co., Ltd.

[0105] Comparative Example 2

[0106] The steps are similar to those in Example 1, except that the long-chain fatty alcohol polyoxypropylene ether (n=5, R is a straight-chain C16-C18 straight-chain alkane) sulfate prepared in Test Example 1 is adjusted to 10 parts, and the long-chain fatty alcohol polyoxypropylene ether (n=8) succinic acid monoester sulfonate prepared in Test Example 5 is adjusted to 50 parts. A new type of yellowing-resistant fatliquor is obtained, which is a yellow translucent liquid in appearance, has a viscosity of 0.66 Pa·s at 40°C, and a pH of 10% by mass of the new type of yellowing-resistant fatliquor emulsion is 6.5.

[0107] Comparative Example 3

[0108] The steps are similar to those in Example 1, except that the long-chain fatty alcohol polyoxypropylene ether (n=5, R is a straight-chain C16-C18 straight-chain alkane) sulfate prepared in Test Example 1 is adjusted to 40 parts, and the long-chain fatty alcohol polyoxypropylene ether (n=8) succinic acid monoester sulfonate prepared in Test Example 5 is adjusted to 20 parts. A new type of yellowing-resistant fatliquor is obtained, which is a yellow translucent liquid in appearance, has a viscosity of 0.58 Pa·s at 40°C, and a pH of 10% by mass of the new type of yellowing-resistant fatliquor emulsion is 6.4.

[0109] Comparative Example 4

[0110] The steps are similar to those in Example 1, except that the O-15 emulsifier is adjusted to 5 parts, and the 32# white oil is adjusted to 35 parts. A new type of yellowing-resistant fatliquor is obtained, which has a light yellow paste appearance, a viscosity of 2.42 Pa·s at 40°C, and a pH of 10% by mass of the new type of yellowing-resistant fatliquor emulsion is 6.5.

[0111] Comparative Example 5

[0112] The steps are similar to those in Example 1, except that the O-15 emulsifier is adjusted to 30 parts, and the 32# white oil is adjusted to 10 parts. A new type of yellowing-resistant fatliquor is obtained, which has a light yellow paste appearance, a viscosity of 1.47 Pa·s at 40°C, and a pH of 6.3 for a 10% by mass new type of yellowing-resistant fatliquor emulsion.

[0113] Comparative Example 6

[0114] The steps are similar to those in Example 1, except that the mixing temperature is controlled at 80°C. A new type of yellowing-resistant fatliquor is obtained, which is a yellow transparent liquid with a viscosity of 0.29 Pa·s at 40°C. The pH of the 10% by mass new type of yellowing-resistant fatliquor emulsion is 6.4. However, a small amount of floating oil will appear in the product after being left for a period of time, which may be due to the decomposition of some materials caused by the excessively high compounding temperature.

[0115] Comparative Example 7

[0116] The steps are similar to those in Example 1, except that the mixing temperature is controlled at 30° C. A new type of yellowing-resistant fatliquor is obtained, which is a yellow transparent liquid in appearance, has a viscosity of 0.32 Pa·s at 40° C., and a pH of 10% by mass of the new type of yellowing-resistant fatliquor emulsion is 6.4. However, the product needs to extend the mixing time during compounding, otherwise the materials are difficult to fully dissolve and mix evenly, and the emulsification of the system may be insufficient.

[0117] Comparative Example 8

[0118] The steps are similar to those in Example 1, except that the solid content is adjusted to 30% during water replenishment. A pale yellow gel product is obtained, which is not suitable for use as a finished fatliquor.

[0119] Comparative Example 9

[0120] The steps are similar to those in Example 1, except that the solid content is adjusted to 80% when adding water. A new type of yellowing-resistant fatliquor is obtained, which is a light yellow viscous paste with almost no fluidity and is not suitable for use as a finished fatliquor.

[0121] Analysis of anti-yellowing fatliquor products:

[0122] The yellow cattle top layer shaved blue wet leather (1.8mm thickness) was used as the test material. Figure 1 The products of Examples 1, 2, 3, and 4 and Comparative Examples 1, 2, 3, 4, and 5 in the preparation of the yellowing-resistant fatliquor were divided and subjected to fatliquor performance tests according to the application process in Table 1, and a sensory evaluation was performed.

[0123] Table 1

[0124]

[0125]

[0126]

[0127] The yellowing resistance (sunlight resistance and UV resistance) of fatliquored leather was analyzed according to the national standard HG / T3689-2001.

[0128] The heat resistance and heat and humidity yellowing resistance of fatliquored leather were analyzed according to the following methods:

[0129] (1) Heat resistance test method:

[0130] ① Sample preparation

[0131] Shape and specification of the sample: Use scissors to cut a rectangular leather blank with a size of 62±2mm*12±2mm, and the thickness of the test piece shall not exceed 50±2mm (the shape and specification of special samples can be determined according to actual conditions). Number of samples: Determined according to the number of test items, and there shall be no less than three valid samples for each test.

[0132] ②Set parameters and install samples

[0133] Set the temperature in the test chamber to 120±2℃. Cover the sample with a light shielding sheet at 20mm from both ends, and place the sample on a tray.

[0134] ③Detection

[0135] Place the tray into the test chamber, turn on the switch, and let the test piece dry for 4 hours. After the specified time is up, take the test piece out of the test chamber and remove the light shielding sheet on the test piece.

[0136] ④Result determination

[0137] Use a gray sample card to directly visually evaluate the yellowing level corresponding to the covered part of the sample under a standard multi-light source color matching light box, and select the worst result as the final result.

[0138] (2) Test method for moisture and heat resistance:

[0139] ① Sample preparation

[0140] Shape and specification of the sample: Use scissors to cut a rectangular leather blank with a size of 62±2mm*12±2mm, and the thickness of the test piece shall not exceed 50±2mm (the shape and specification of special samples can be determined according to actual conditions). Number of samples: Determined according to the number of test items, and there shall be no less than three valid samples for each test.

[0141] ②Set parameters and install samples

[0142] Use a constant temperature and humidity box, set the humidity to 95% RH, cover the sample with a shading sheet at 20 mm on both ends, and place the sample on a tray.

[0143] ③Detection

[0144] Place the dryer in a constant temperature and humidity chamber, turn on the switch (set the temperature to 60°C), and store the sample for 36 hours. After the specified time is up, remove the test piece from the test chamber.

[0145] ④Result determination

[0146] Use a gray sample card to directly visually evaluate the yellowing level corresponding to the covered part of the sample under a standard multi-light source color matching light box, and select the worst result as the final result.

[0147] The application performance evaluation results of the new yellowing-resistant leather fatliquor emulsion are shown in Table 2 below.

[0148] Table 2

[0149]

[0150]

[0151] It can be seen from the above results that choosing a suitable compounding ratio can better coordinate the state, stability and application performance of the fatliquor. The fatliquor compounded in the scheme provided by the present invention is transparent and stable, has excellent application performance, and has good yellowing resistance. When it is applied to leather fatliquor, it can not only make the leather soft and plump, but also give the leather a higher yellowing resistance grade; while the fatliquor in the comparative example is difficult to maintain coordination between appearance state, stability and application performance.

[0152] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A novel yellowing-resistant leather fatliquor, characterized in that: The raw materials for its preparation include: long-chain fatty alcohol polyoxypropylene ether, and the structural formula of the long-chain fatty alcohol polyoxypropylene ether is as follows: In the above formula, R is a straight-chain C16-C18 straight-chain alkane, n is the degree of polymerization of propylene oxide, and n=5-10.

2. The novel yellowing-resistant leather fatliquor according to claim 1, characterized in that The main components of the novel yellowing-resistant leather fatliquor include: long-chain fatty alcohol polyoxypropylene ether sulfate and long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate prepared by using long-chain fatty alcohol polyoxypropylene ether, as well as nonionic emulsifier, mineral oil and water.

3. The novel yellowing-resistant leather fatliquor according to claim 2, characterized in that, The long-chain fatty alcohol polyoxypropylene ether sulfate is prepared by subjecting the long-chain fatty alcohol polyoxypropylene ether to a sulfonation reaction and then a neutralization reaction.

4. The novel yellowing-resistant leather fatliquor according to claim 3, characterized in that: The long-chain fatty alcohol polyoxypropylene ether sulfate is prepared by the following method: the long-chain fatty alcohol polyoxypropylene ether is subjected to a gas-liquid sulfonation reaction with a SO3 component through a membrane sulfonation reactor, and then subjected to a neutralization reaction to obtain the long-chain fatty alcohol polyoxypropylene ether sulfate; Preferably, the structural formula of the long-chain fatty alcohol polyoxypropylene ether is as follows: In the above formula, R is a straight-chain C16-C18 straight-chain alkane, n is the degree of polymerization of propylene oxide, n=5-10; Preferably, the temperature of the long-chain fatty alcohol polyoxypropylene ether entering the membrane sulfonation reactor is 10 to 50° C.; Preferably, the jacket water bath circulation temperature of the membrane sulfonation reactor is 30 to 80°C; Preferably, the SO3 component is a mixed gas of SO3 / air, wherein the volume percentage of SO3 in the mixed gas is 3% to 7%, and the temperature of the SO3 component entering the membrane sulfonation reactor is 40 to 60°C; Preferably, the molar ratio of the SO3 component to the long-chain fatty alcohol polyoxypropylene ether is 0.80-1.10:1, and the structural formula of the long-chain fatty alcohol polyoxypropylene ether sulfate obtained by the gas-liquid sulfonation reaction is as follows: Preferably, the alkaline solution used in the neutralization reaction includes one of a NaOH solution with a mass concentration of 30%, a KOH solution with a mass concentration of 50%, and an NH4OH solution with a mass concentration of 28%, wherein: the neutralization reaction temperature is 40-60°C, the time is 0.5-2h, the pH is 7.5-9.0, and the long-chain fatty alcohol polyoxypropylene ether sulfate obtained by the reaction of the long-chain fatty alcohol polyoxypropylene ether sulfate with the alkaline solution has the following structural formula: In the above formula, M is at least one of Na, K, and NH4; Preferably, the long-chain fatty alcohol polyoxypropylene ether sulfate needs to be decolorized, and the decolorization is carried out under weakly alkaline conditions, wherein: the pH of the decolorization is 8.0-8.5, the temperature is 50-70°C, the time is 1-3h, and the decolorizing agent includes any one of hydrogen peroxide, thiourea dioxide, and sodium bisulfite.

5. The novel yellowing-resistant leather fatliquor according to claim 2, characterized in that, The long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate is prepared by subjecting long-chain fatty alcohol polyoxypropylene ether to succinic acid sulfonation reaction.

6. The novel yellowing-resistant leather fatliquor according to claim 5, characterized in that: The long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate is prepared by the following method: esterifying long-chain fatty alcohol polyoxypropylene ether with maleic anhydride to obtain long-chain fatty alcohol polyoxypropylene ether succinic acid monoester; then sulfiting the long-chain fatty alcohol polyoxypropylene ether succinic acid monoester with sodium sulfite to obtain long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate; Preferably, the molar ratio of the long-chain fatty alcohol polyoxypropylene ether to maleic anhydride is 1-1.2:1, the esterification reaction temperature is 90-105° C., and the esterification reaction time is 2.5-3.5 h. Preferably, the molar ratio of long-chain fatty alcohol polyoxypropylene ether succinic acid monoester to sodium sulfite is 1-1.2:1, the sulfitation reaction temperature is 75-85° C., and the sulfitation reaction time is 2.5-3.5 h.

7. The novel yellowing-resistant leather fatliquor according to claim 2, characterized in that: The nonionic emulsifier includes at least one of O-15 and O-20, and the mineral oil includes at least one of 32# white oil and 36# white oil.

8. A method for preparing a novel yellowing-resistant leather fatliquor according to any one of claims 1 to 7, characterized in that: The following steps are involved: Long-chain fatty alcohol polyoxypropylene ether sulfate, long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate, nonionic emulsifier and mineral oil are mixed and stirred at 50-60° C. for 30 minutes, water is added to a solid content of 50-60%, and stirred for another hour to obtain the novel yellowing-resistant leather fatliquor; Preferably, based on 100% solid content, the amount of the long-chain fatty alcohol polyoxypropylene ether sulfate is 20 to 30 parts; Preferably, based on 100% solid content, the amount of the long-chain fatty alcohol polyoxypropylene ether succinic acid monoester sulfonate is 30 to 40 parts; Preferably, the nonionic emulsifier is used in an amount of 10 to 20 parts; Preferably, the amount of the mineral oil is 20 to 30 parts.

9. The preparation method according to claim 8, characterized in that: The viscosity of the novel anti-yellowing leather fatliquor at 40° C. is 0.2-0.4 Pa·s; the pH value of the novel anti-yellowing leather fatliquor with a mass percentage of 10% is 6.0-7.

0.

10. Use of the novel yellowing-resistant leather fatliquor according to any one of claims 1 to 7 or the novel yellowing-resistant leather fatliquor prepared by the preparation method according to any one of claims 8 to 9 in leather processing.

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