Leather finishing agent, preparation method and application thereof

Abstract

The present invention provides a leather finishing agent and a preparation method and application thereof, belonging to the field of leather finishing technology. The leather finishing agent provided by the present invention is specifically compounded by poly-α-olefin synthetic oil, mineral oil and vegetable oil, overcoming the problems of odor, poor finishing performance and poor storage stability of leather finishing agents in the prior art, and can effectively inhibit the oxidation reaction of oil and fat in the product. When used in the field of leather finishing, it can effectively reduce the risk of coating odor deterioration; the leather finishing agent provided by the present invention achieves the effect of adjusting the touch of leather to a dry, smooth and dense effect, making the leather dense, smooth, and rich in moisturizing feeling, which is closer to the feel of animal skin itself; it has good thermal stability, low temperature resistance and other properties, is easy to self-emulsify and disperse in the aqueous phase, and can be used as an additive to be better compounded with other leather finishing materials.

Description

Technical Field

[0001] The present invention relates to the technical field of leather finishing, in particular to a leather finishing agent and a preparation method and application thereof. Background Art

[0002] Finished leather is made from animal hides through a complex process involving preparation, tanning, finishing, and coating. The final finishing step imparts a variety of colors, sheens, and styles to the leather surface, while also imparting a certain tactile feel, stain resistance, and ease of care. Leather finishing materials typically use water as a liquid carrier, with synthetic resin film-forming agents as their primary active ingredient. Once the synthetic resin film forms and cures, it imparts a plastic feel, which is generally undesirable. Leather products require the addition of oils and fats to improve their processing properties. Finishing oils can reduce the plastic feel introduced by the film-forming resin and enhance the overall brightness, fullness, moisturization, and tactile feel of the coating. Currently, finishing oils in the leather industry primarily utilize emulsified natural oils that have been emulsified with water. These oils offer a relatively simple tactile quality, primarily focusing on moisturizing and slippery textures, lacking the multi-dimensional tactile qualities of dryness, smoothness, and silkiness.

[0003] Chemicals are involved in every step of leather production, so the leather's odor is not only due to the characteristic smell of the leather itself, but also due to the deterioration and aging of the chemicals. The stability of the leather coating during storage is poor, and the odor may be generated, which reduces the leather's quality.

[0004] Various leather finishing agents are currently available. For example, Chinese Patent CN114181592A discloses a water-based leather finishing agent, its application, and a leather treatment method. This water-based leather finishing agent comprises, among other components, a bisphenol A epoxy resin aqueous emulsion, a plasticizer, and castor oil. However, this product cannot prevent the leather from developing an odor after finishing. Furthermore, as a water-based leather finishing agent, its storage stability is poor. Over time, the water and oil phases in the product will separate to some extent, thus affecting its performance. Summary of the Invention

[0005] The object of the present invention is to provide a leather finishing agent to solve the problems of the leather finishing agent in the prior art, such as odor, poor finishing performance and poor storage stability.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a leather finishing agent comprising the following components in parts by weight:

[0008] 30-50 parts of vegetable oil, 20-30 parts of polyalphaolefin synthetic oil, 10-20 parts of mineral oil, 10-20 parts of emulsifier and 0.2-2 parts of antioxidant;

[0009] The iodine value of the vegetable oil is in the range of ≤110g / 100g.

[0010] In the present invention, "iodine value" refers to the amount of iodine (g) required when 100 g of a lipid sample is fully halogenated.

[0011] Preferably, the vegetable oil is selected from one or more of peanut oil, olive oil, palm oil, tea oil, castor oil, coconut oil or cocoa butter.

[0012] Preferably, the mineral oil is refined white oil.

[0013] Preferably, the emulsifier is selected from one or more of fatty alcohol polyoxyethylene ether, polyol polyoxyethylene ether, alkylphenol polyoxyethylene ether, polyol polyoxyethylene ether fatty acid ester or sorbitan ester.

[0014] Preferably, the antioxidant is selected from one or more of 2,6-di-tert-butyl-4-methylphenol, butylated hydroxyanisole, and synthetic vitamin E.

[0015] The present invention also provides a method for preparing the leather finishing agent, comprising the following steps:

[0016] S1, mixing the vegetable oil, emulsifier and antioxidant for 50 to 150 minutes to obtain a first mixture;

[0017] S2. Mixing the first mixture with poly-α-olefin synthetic oil and mineral oil for 50 to 120 minutes to obtain a leather finishing agent.

[0018] Preferably, in S1, the mixing temperature is 50-70°C;

[0019] The mixing is accompanied by stirring, and the stirring rate is 100 to 500 r / min.

[0020] Preferably, in S2, the mixing temperature is 50-70°C;

[0021] The mixing is accompanied by stirring, and the stirring rate is 100 to 500 r / min.

[0022] Preferably, after the first mixture is mixed with the poly-α-olefin synthetic oil and the mineral oil, the temperature is cooled to 5-40°C.

[0023] The present invention also provides the leather finishing agent and the use of the leather finishing agent obtained by the preparation method in improving the brightness, fullness, moistness or touch of leather.

[0024] Beneficial effects of the present invention:

[0025] The leather finishing agent provided by the present invention is specifically compounded by poly-α-olefin synthetic oil, mineral oil and vegetable oil, which can effectively inhibit the oxidation reaction of oil in the product. When used in the leather finishing field, it can effectively reduce the risk of coating odor deterioration; when the coated leather material is used in a car, it can effectively alleviate the odor in the car, and has good application prospects.

[0026] The leather finishing agent provided by the present invention can adjust the touch of leather to a dry, smooth and dense effect, making the leather dense, smooth, rich in moisturizing feeling, and closer to the feel of animal skin itself.

[0027] The leather finishing agent provided by the present invention does not contain water, has good thermal stability, low-temperature resistance and other properties, can inhibit the unsaturated fatty acid free radical chain reaction occurring in the product, and improve the oxidative stability of the product; it is easy to self-emulsify and disperse in the aqueous phase, and can be used as an additive to be better compounded with other leather finishing materials. DETAILED DESCRIPTION

[0028] The invention provides a leather finishing agent, which comprises the following components in parts by weight: 30-50 parts of vegetable oil, 20-30 parts of polyalphaolefin synthetic oil, 10-20 parts of mineral oil, 10-20 parts of emulsifier and 0.2-2 parts of antioxidant.

[0029] In the present invention, the leather finishing agent comprises 30 to 50 parts of vegetable oil, more preferably 35 to 45 parts, and the iodine value of the vegetable oil is ≤110 g / 100 g, more preferably ≤60 g / 100 g;

[0030] The vegetable oil is preferably selected from one or more of peanut oil, olive oil, palm oil, tea oil, castor oil, coconut oil or cocoa butter, and is further preferably peanut oil or olive oil. The vegetable oil is in the form of a translucent, clear liquid with a bland odor. When compounded with the poly-α-olefin synthetic oil and mineral oil in the leather finishing agent, it can enhance the moisturizing feeling and optimize the touch of the leather. When the amount of vegetable oil added is too much, the leather will feel "greasy", and when too little, the moisturizing requirements cannot be met. Therefore, the vegetable oil can achieve the best effect within the weight range provided by the present invention.

[0031] In the present invention, the components of the leather finishing agent include 20 to 30 parts of polyα-olefin synthetic oil, and more preferably 23 to 28 parts. The polyα-olefin synthetic oil, also known as PAO, is a saturated olefin oligomer with strong low-temperature fluidity. When compounded with the vegetable oil and mineral oil in the leather finishing agent in a specific proportion, it can improve the product's oxidative stability and optimize the leather's touch, adjust the "slippery feel" of the leather to the optimal state, and achieve the best effect within the weight ratio range provided by the present invention.

[0032] In the present invention, the components of the leather finishing agent include 10 to 20 parts of mineral oil, more preferably 13 to 18 parts. The mineral oil is preferably refined white oil with a molecular weight in the range of 250 to 450, and is colorless and odorless. It can be selected from one or more of conventional commercially available products such as 26# white oil, 32# white oil, and 100# white oil.

[0033] In the present invention, the components of the leather finishing agent include 10 to 20 parts of an emulsifier, more preferably 13 to 18 parts, and the emulsifier is preferably one or more selected from fatty alcohol polyoxyethylene ether, polyol polyoxyethylene ether, alkylphenol polyoxyethylene ether, polyol polyoxyethylene ether fatty acid ester or sorbitan ester.

[0034] In the present invention, the components of the leather finishing agent include 0.2 to 2 parts of antioxidant, more preferably 0.5 to 1.5 parts, and the antioxidant is preferably one or more selected from 2,6-di-tert-butyl-4-methylphenol, butylated hydroxyanisole, and synthetic vitamin E.

[0035] The present invention also provides a method for preparing the leather finishing agent, comprising the following steps:

[0036] S1. Mixing the vegetable oil, emulsifier, and antioxidant for 50 to 150 minutes to obtain a first mixture, wherein the mixing temperature is preferably 50 to 70° C., and the mixing is accompanied by stirring at a rate of preferably 100 to 500 rpm;

[0037] S2. Mix the first mixture with polyα-olefin synthetic oil and mineral oil for 50 to 120 minutes to obtain a leather finishing agent. The mixing temperature is preferably 50 to 70°C, and the mixing is accompanied by stirring at a rate of preferably 100 to 500 r / min. The method for preparing the leather finishing agent is also preferably to cool the first mixture with the polyα-olefin synthetic oil and mineral oil to a temperature of 5 to 40°C, more preferably to room temperature. The room temperature range of the present invention is 16 to 25°C.

[0038] The present invention also provides the leather finishing agent and the use of the leather finishing agent obtained by the preparation method in improving the brightness, fullness, moistness or touch of leather.

[0039] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0040] Example 1

[0041] Take 42kg peanut oil, 27kg poly-α-olefin synthetic oil, 18kg 100# white oil, 12.5kg isomeric tridecanol polyoxyethylene ether (1303), and 0.5kg 2,6-di-tert-butyl-4-methylphenol and set aside;

[0042] Peanut oil, isomeric tridecanol polyoxyethylene ether (1303) and 2,6-di-tert-butyl-4-methylphenol emulsifier were added to a dispersion kettle at 60°C and dispersed at a stirring speed of 350 r / min for 70 minutes.

[0043] Add polyalphaolefin synthetic oil and 100# white oil, maintain the temperature, continue stirring for 72 minutes, then reduce the stirring rate to 200 r / min, add circulating water to cool down to room temperature (26° C.) to obtain the leather finishing agent.

[0044] Example 2

[0045] Take 42 kg of peanut oil, 27 kg of poly-α-olefin synthetic oil, 18 kg of 26# white oil, 12.5 kg of fatty alcohol polyoxyethylene ether (AEO-3), and 0.5 kg of 2,6-di-tert-butyl-4-methylphenol and set aside;

[0046] Peanut oil, fatty alcohol polyoxyethylene ether (AEO-3) and 2,6-di-tert-butyl-4-methylphenol emulsifier were added to a dispersion kettle at 60°C and dispersed at a stirring rate of 400 r / min for 60 minutes;

[0047] Add polyalphaolefin synthetic oil and 26# white oil, maintain the temperature, continue stirring for 60 minutes, then reduce the stirring rate to 200 r / min, add circulating water to cool down to room temperature (30° C.) to obtain the leather finishing agent.

[0048] Example 3

[0049] Take 42 kg of olive oil, 27 kg of poly-α-olefin synthetic oil, 18 kg of 26# white oil, 12.5 kg of fatty alcohol polyoxyethylene ether (AEO-3), and 0.5 kg of 2,6-di-tert-butyl-4-methylphenol and set aside;

[0050] Olive oil, fatty alcohol polyoxyethylene ether (AEO-3) and 2,6-di-tert-butyl-4-methylphenol emulsifier were added to a dispersion kettle at 60°C and dispersed at a stirring rate of 400 r / min for 60 minutes;

[0051] Add polyalphaolefin synthetic oil and 26# white oil, maintain the temperature, continue stirring for 60 minutes, then reduce the stirring rate to 200 r / min, add circulating water to cool down to room temperature (26° C.) to obtain the leather finishing agent.

[0052] Example 4

[0053] Take 42kg of coconut oil, 27kg of poly-α-olefin synthetic oil, 18kg of 26# white oil, 12.5kg of fatty alcohol polyoxyethylene ether (AEO-3), and 0.5kg of butylated hydroxyanisole, and set aside;

[0054] Coconut oil, fatty alcohol polyoxyethylene ether (AEO-3) and butylated hydroxyanisole emulsifier were added to a dispersion kettle at 60°C and dispersed at a stirring rate of 400 r / min for 60 minutes;

[0055] Add polyalphaolefin synthetic oil and 26# white oil, maintain the temperature, continue stirring for 60 minutes, then reduce the stirring rate to 200 r / min, add circulating water to cool down to room temperature (26° C.) to obtain the leather finishing agent.

[0056] Comparative Example 1

[0057] The only difference from Example 1 is that the poly-α-olefin synthetic oil is replaced by silicone oil.

[0058] Comparative Example 2

[0059] The only difference from Example 1 is that peanut oil is replaced by sunflower oil.

[0060] Comparative Example 3

[0061] The only difference from Example 1 is that the amount of poly-α-olefin synthetic oil added is changed to 45 kg.

[0062] Experimental Example 1 Measurement of leather feel after coating

[0063] The leather finishing agents of Examples 1 to 4 and Comparative Examples 1 to 3 were applied to leather:

[0064] Leather finishing oil is mainly used together with the composite resin of primer / midcoat. The finishing oil is added to the composite resin and dispersed at high speed. Self-emulsification of the finishing oil occurs during the high-speed stirring and dispersion process. The amount of finishing oil used is 2.5% of the composite resin system. Due to the high viscosity of the composite resin, the construction method is roller coating, and the number of roller coatings is 2. The first roller coating amount is 7-8g / sf; the second roller coating amount is 4-5g / sf.

[0065] The leather type is cowhide.

[0066] After finishing, experienced evaluators were selected to measure the leather feel. The leather was graded from 1 to 5 based on human sensory touch, with 1 being the worst and 5 being the highest. The grading standards are as follows:

[0067] Level 1: rough, no oily feeling;

[0068] Level 2: slightly rough and slightly oily;

[0069] Level 3: Oily, smooth, slightly dry;

[0070] Level 4: oily, smooth, slightly oily;

[0071] Level 5: oily and smooth;

[0072] The results are shown in the following table:

[0073] Table 1 Test results of leather feel after coating

[0074] Scoring result 1 Scoring result 2 Scoring result 3 Comprehensive Assessment Example 1 Level 5 Level 5 Level 4 4.6 magnitude Example 2 Level 4 Level 4 Level 5 4.3 Example 3 Level 5 Level 4 Level 4 4.3 Example 4 Level 4 Level 4 Level 4 Level 4 Comparative Example 1 Level 2 Level 3 Level 3 2.6 Comparative Example 2 Level 3 Level 4 Level 3 Level 3.3 Comparative Example 3 Level 3 Level 4 Level 2 Level 3

[0075] Experimental Example 2

[0076] The performance of the leather finishing agents of Examples 1 to 4 and Comparative Examples 1 to 3 was measured. The results are shown in Table 2 below:

[0077] Table 2 Performance test results

[0078]

[0079]

[0080] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A leather finishing agent, characterized in that: It is composed of the following components in parts by weight: 30-50 parts of vegetable oil, 20-30 parts of polyalphaolefin synthetic oil, 10-20 parts of mineral oil, 10-20 parts of emulsifier and 0.2-2 parts of antioxidant; The iodine value of the vegetable oil is in the range of ≤110g / 100g; The vegetable oil is selected from one or more of peanut oil, olive oil, tea oil, castor oil, coconut oil or cocoa butter; The mineral oil is refined white oil; The molecular weight of the refined white oil is 250-450.

2. The leather finishing agent according to claim 1, characterized in that The emulsifier is selected from one or more of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, polyol polyoxyethylene ether fatty acid ester or sorbitan ester.

3. The leather finishing agent according to claim 1, characterized in that The antioxidant is selected from one or more of 2,6-di-tert-butyl-4-methylphenol, butylated hydroxyanisole, and synthetic vitamin E.

4. The method for preparing the leather finishing agent according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1, mixing the vegetable oil, emulsifier and antioxidant for 50 to 150 minutes to obtain a first mixture; S2. Mixing the first mixture with poly-α-olefin synthetic oil and mineral oil for 50 to 120 minutes to obtain a leather finishing agent.

5. The method for preparing the leather finishing agent according to claim 4, wherein In S1, the mixing temperature is 50-70°C; The mixing is accompanied by stirring, and the stirring rate is 100 to 500 r / min.

6. The method for preparing the leather finishing agent according to claim 4, wherein In S2, the mixing temperature is 50-70°C; The mixing is accompanied by stirring, and the stirring rate is 100 to 500 r / min.

7. The method for preparing the leather finishing agent according to claim 6, wherein: After the first mixture is mixed with poly-α-olefin synthetic oil and mineral oil, the temperature is cooled to 5-40°C.

8. Use of the leather finishing agent according to any one of claims 1 to 3 or the leather finishing agent obtained by the preparation method according to any one of claims 4 to 7 for improving the brightness, fullness, moistness or touch of leather.

Images