Waterproof leather finishing agent and preparation method thereof

Abstract

The invention relates to the technical field of leather coatings, and particularly discloses a waterproof leather finishing agent which comprises the following components in parts by weight: 30-50 parts of resin, 1.5-3 parts of a thickening leveling agent, 0.5-1.5 parts of a wetting leveling agent, 2-5 parts of an isocyanate curing agent, 0.5-1 part of a wax emulsion, 0.5-0.7 part of a defoaming agent and 70-80 parts of water, the resin comprises anionic carboxylic acid type water-based resin and anionic aliphatic water-based polyurethane resin in a weight ratio of (4-8): 1; the preparation method of the waterproof leather finishing agent comprises the following steps: sequentially adding the anionic carboxylic acid type waterborne resin, the wax emulsion, the defoaming agent, the anionic aliphatic waterborne polyurethane resin, the isocyanate curing agent, the thickening leveling agent and the wetting leveling agent into water under the stirring action, and uniformly stirring to obtain the waterproof leather finishing agent. The waterproof leather finishing agent has good waterproofness, and after a leather material made of the waterproof leather finishing agent is subjected to water cutting, no water stain is left.

Description

TECHNICAL FIELD

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

[0002] In recent years, leather products are widely used in daily life, such as car interior roof, car seats, leather clothing, leather shoes and bags, etc. With the improvement of consumers' living standards and aesthetics, the requirements for leather quality and appearance are also increasing. Leather finishing agent plays a key role in improving leather quality, appearance and durability. It can endow leather with various properties to meet the needs of different consumers and further promote the development of leather industry.

[0003] In the field of leather processing, common leather treatment agents mainly include water-based finishing agents, oil-based finishing agents and natural oil-based finishing agents. Among them, water-based finishing agents are mixed by adding various film-forming substances, additives, etc. with water as solvent, and are uniformly coated on the surface of leather by spraying, brushing, etc. to form a protective film, thereby playing a certain decorative and protective role. Oil-based finishing agents are carried by organic solvents, and by adding resin and other ingredients, they can endow leather with good gloss and texture. Natural oil-based finishing agents, such as animal fat, vegetable fat, etc., can moisturize leather and enhance the flexibility and wear resistance of leather. However, the above-mentioned leather finishing agents still have defects in use. When they are used on the surface of leather, obvious water stain marks will appear on the surface of leather after water cutting, which seriously affects the appearance quality and overall quality of leather products.

[0004] The present application provides a waterproof leather finishing agent and a preparation method thereof to overcome the problem of obvious water stain marks on the surface of leather after water cutting of the leather material prepared by the existing leather finishing agent.

[0005] In the first aspect, the present application provides a waterproof leather finishing agent and a preparation method thereof, which adopts the following technical scheme: a waterproof leather finishing agent and a preparation method thereof, comprising the following components by weight: resin 30-50 parts, thickening and leveling agent 1.5-3 parts, wetting and leveling agent 0.5-1.5 parts, isocyanate curing agent 2-5 parts, wax emulsion 0.5-1 part, defoaming agent 0.5-0.7 part and water 70-80 parts. The resin comprises anionic carboxylic acid type water-based resin and anionic fatty water-based polyurethane resin in a weight ratio of (4-8): 1.

[0006] This application uses resin, thickener, wetting and leveling agent, etc. to prepare a waterproof leather finishing agent. By using anionic carboxylic acid type water-based resin and anionic aliphatic water-based polyurethane resin as the main components, the obtained leather finishing agent has excellent waterproof properties on the one hand, and the leather produced will not have water stains on the surface after water cutting; on the other hand, it also has good wear resistance and can play a good protective role for the leather. Specifically: the anionic carboxylic acid type water-based resin itself has a certain hydrophobicity. When the resin is coated on the leather surface and forms a thin film, this film can effectively block the penetration of water molecules, thereby improving the waterproof performance of the leather. In addition, the anionic carboxylic acid type water-based resin has good dispersibility, which can make the finishing agent evenly distributed on the leather surface. At the same time, its carboxyl group can interact with some groups on the leather surface to enhance the bonding strength between the finishing agent and the leather. The anionic aliphatic water-based polyurethane resin has excellent flexibility, wear resistance and adhesion, and can significantly improve the waterproofness and wear resistance of the leather. This application forms a continuous and dense protective film on the leather surface by mixing anionic carboxylic acid type water-based resin and anionic aliphatic water-based polyurethane resin in a specific ratio. This protective film can not only effectively block the intrusion of water, avoid water stains on the leather surface after water cutting, and improve the appearance quality and overall quality of leather products; on the other hand, it can also give the leather good flexibility and wear resistance, making it more durable. The thickening and leveling agent can adjust the rheological properties of the finishing agent, making it easier to level during construction; the wetting and leveling agent can reduce surface tension and promote better spreading of the finishing agent; the isocyanate curing agent can make the finishing agent form a strong cross-linked structure, enhancing the hardness and wear resistance of the coating; the wax emulsion has excellent anti-adhesion ability, which helps to improve the gloss and waterproof performance of the leather surface; the defoaming agent can eliminate bubbles generated by the finishing agent during production and use, ensuring the uniformity of the finishing effect. In summary, the waterproof leather finishing agent prepared in this application can form a protective film on the surface of the leather finishing agent, which plays a decorative and protective role on the leather, while avoiding water stains on the leather surface after water cutting, thereby improving the appearance quality and overall quality of leather products.

[0007] In some embodiments, the weight ratio of the anionic carboxylic acid type aqueous resin to the anionic aliphatic aqueous polyurethane resin can be (4-5):1, (4-6):1, (4-7):1, (4-8):1, (5-6):1, (5-7):1, (5-8):1, (6-7):1, (6-8):1 or (7-8):1.

[0008] In a specific embodiment, the weight ratio of the anionic carboxylic acid type waterborne resin to the anionic aliphatic waterborne polyurethane resin can also be 4:1, 5:1, 6:1, 8:1 or 9:1.

[0009] Optionally, the waterproof leather finishing agent comprises the following components in parts by weight: 35-45 parts of resin, 1.5-3 parts of thickening and leveling agent, 0.5-1.5 parts of wetting and leveling agent, 3-4 parts of isocyanate curing agent, 0.5-1 part of wax emulsion, 0.5-0.7 part of defoaming agent and 70-80 parts of water.

[0010] In some embodiments, the weight parts of the resin may be 30-35 parts, 30-42 parts, 35-42 parts, 35-50 parts, or 42-50 parts.

[0011] In a specific embodiment, the weight portion of the resin may also be 30 parts, 35 parts, 42 parts or 50 parts.

[0012] Optionally, the weight ratio of the anionic carboxylic acid type water-based resin to the anionic aliphatic water-based polyurethane resin is (5-7):1.

[0013] In some embodiments, the weight ratio of the anionic carboxylic acid type aqueous resin to the anionic aliphatic aqueous polyurethane resin can be (4-5):1, (4-6):1, (4-7):1, (4-8):1, (5-6):1, (5-7):1, (5-8):1, (6-7):1, (6-8):1 or (7-8):1.

[0014] In a specific embodiment, the weight ratio of the anionic carboxylic acid type waterborne resin to the anionic aliphatic waterborne polyurethane resin can also be 4:1, 5:1, 6:1, 7:1 or 8:1.

[0015] Optionally, the isocyanate curing agent is selected from one or more of Uahard BL2002, HW 2100CN, xyh001 and BL-936.

[0016] Optionally, the isocyanate curing agent is a mixture of Uahard BL2002 and xyh001; the weight ratio of Uahard BL2002 to xyh001 is 1:(0.15-0.4).

[0017] In this application, by selecting a mixture of Uahard BL2002 and XYH001 in a specific weight ratio as an isocyanate curing agent, this optimized curing system enables the finishing agent to form a stronger and more stable protective film on the leather surface, greatly enhancing the leather's waterproof ability and significantly reducing the occurrence of water stains on the leather surface after water cutting, thereby ensuring the appearance quality of the leather product. At the same time, it also improves the durability and flexibility of the leather, further enhancing the overall quality of the leather product, meeting consumers' high demands for leather quality and appearance, and promoting the development of the leather industry. In other words, the further selection of the above-mentioned curing system in this application enables the waterproof leather finishing agent to be better cured on the leather surface, thereby better exerting its waterproof and wear-resistant properties.

[0018] In some embodiments, the weight ratio of Uahard BL2002 and xyh001 can be 1:(0.15-0.2), 1:(0.15-0.35), 1:(0.15-0.4), 1:(0.2-0.35), 1:(0.2-0.4) or 1:(0.35-0.4).

[0019] In a specific embodiment, the weight ratio of Uahard BL2002 to xyh001 can also be 1:0.15, 1:0.2, 1:0.35 or 1:0.4.

[0020] In some embodiments, the weight ratio of Uahard BL2002 to xyh001 can be 1:(0.15-0.2), 1:(0.15-0.35), 1:(0.2-0.35), 1:(0.2-0.4), or 1:(0.35-0.4).

[0021] In a specific embodiment, the weight ratio of Uahard BL2002 to xyh001 can also be 1:0.15, 1:0.2, 1:0.35 or 1:0.4.

[0022] Optionally, the thickening and leveling agent is of polyurethane type, selected from one or more of 635TDS, QSC-6410, UH-420, UH-752 and UH-756vf.

[0023] Optionally, the wetting and leveling agent is selected from one or more of YMT-328, HZ-1336, BYK-300, TEGO Glide 410, TEGO Glide 450 and TEGO Glide 100.

[0024] In a second aspect, the present application provides a method for preparing a waterproof leather finishing agent, comprising the following steps: adding anionic carboxylic acid type water-based resin, wax emulsion, defoaming agent, anionic aliphatic water-based polyurethane resin, isocyanate curing agent, thickening and leveling agent, and wetting and leveling agent to water in sequence under stirring, stirring evenly, and obtaining a waterproof leather finishing agent.

[0025] Optionally, the time interval between adding the adjacent components is 5-30 min.

[0026] In summary, this application has the following beneficial effects: 1. This application uses anionic carboxylic acid type water-based resin and anionic aliphatic water-based polyurethane resin in a weight ratio of (4-8): 1 as main components, and uses isocyanate as a curing agent to prepare a waterproof leather finishing agent with excellent wear resistance and waterproof properties. When used on the leather surface, it can effectively prevent water stains on the leather after water cutting, which affects the leather quality.

[0027] 2. The waterproof leather finishing agent provided in this application is used to prepare leather samples. The abrasion resistance of the leather sample coating is 1000-1300 times, and the water contact angle is 124-158°. 3. The present application further controls the weight ratio of the anionic carboxylic acid type water-based resin to the anionic aliphatic water-based polyurethane resin within the range of (5-7):1, and the amount of resin added is controlled between 35-45 parts. The waterproof performance of the obtained waterproof leather finishing agent is better, and the water contact angle of the coating surface can reach more than 130°.

[0028] 4. This application further uses Uahard BL2002 and xyh001 in a weight ratio of 1: (0.15-0.4) as isocyanate curing agents, and the resulting waterproof leather finishing agent has better wear resistance and waterproof properties. The wear resistance of the leather sample coating can reach 1,300 times, and the water contact angle can reach more than 150°. DETAILED DESCRIPTION

[0029] The present application provides a waterproof leather finishing agent, comprising the following components in parts by weight: 30-50 parts of resin, 1.5-3 parts of thickening and leveling agent, 0.5-1.5 parts of wetting and leveling agent, 2-5 parts of isocyanate curing agent, 0.5-1 part of wax emulsion, 0.5-0.7 part of defoaming agent and 70-80 parts of water; further, the waterproof leather finishing agent comprises the following components in parts by weight: 35-45 parts of resin, 1.5-3 parts of thickening and leveling agent, 0.5-1.5 parts of wetting and leveling agent, 3-4 parts of isocyanate curing agent, 0.5-1 part of wax emulsion, 0.5-0.7 part of defoaming agent and 70-80 parts of water.

[0030] The resin comprises an anionic carboxylic acid waterborne resin and an anionic aliphatic waterborne polyurethane resin in a weight ratio of (4-8):1. Furthermore, the weight ratio of the anionic carboxylic acid waterborne resin and the anionic aliphatic waterborne polyurethane resin is (5-7):1.

[0031] The raw materials, reagents, solvents, etc. used in the examples of this application can all be obtained commercially.

[0032] The present application is further described in detail below with reference to embodiments and performance testing.

[0033] Examples 1-8 Examples 1-8 each provide a waterproof leather finishing agent.

[0034] The difference between the above embodiment and embodiment 2 is that the addition amount and weight ratio of the anionic carboxylic acid type waterborne resin and the anionic aliphatic waterborne polyurethane resin are shown in Table 1 below.

[0035] The preparation method of the waterproof leather finishing agent provided in Example 1-8 comprises the following steps: adding anionic carboxylic acid type water-based resin DL1201 to 750g of water under stirring, stirring for 20min; then adding 8g of wax emulsion; 259, 6g of defoamer TSA-630, stirred for 5 minutes; then added anionic aliphatic waterborne polyurethane resin ML-3009-3, stirred for 10 minutes; then added 30g of isocyanate curing agent Uahard BL2002, stirred for 20 minutes; then added 20g of thickening and leveling agent 635TDS and 10g of wetting and leveling agent YMT-328, stirred for 30 minutes to obtain a waterproof leather finishing agent.

[0036] Table 1 Addition amount and weight ratio of resin in the waterproof leather finishing agent provided by Examples 1-8 Examples 9-16 Examples 9-16 each provide a waterproof leather finishing agent.

[0037] The difference between the above embodiment and embodiment 3 is: the type and ratio of the isocyanate curing agent, as shown in Table 2 below.

[0038] Table 2 Types and ratios of isocyanate curing agents in Example 3 and Examples 9-16 Example Types of isocyanate curing agents 3 Uahard BL2002 9 xyh001 10 BL-936 11 Uahard BL2002 and xyh001 with a weight ratio of 1:0.15 12 Uahard BL2002 and xyh001 with a weight ratio of 1:0.2 13 Uahard BL2002 and xyh001 with a weight ratio of 1:0.35 14 Uahard BL2002 and xyh001 with a weight ratio of 1:0.4 15 Uahard BL2002 and BL-936 with a weight ratio of 1:0.2 16 BL-936 and xyh001 with a weight ratio of 1:0.2 Example 17 Example 17 provides a waterproof leather finishing agent.

[0039] The difference between the above embodiment and embodiment 3 is that the added amount of the isocyanate curing agent Uahard BL2002 is 40 g.

[0040] Comparative Example 1 Comparative Example 1 provides a waterproof leather finishing agent.

[0041] The difference between the comparative example and Example 3 is that the addition amount of the anionic carboxylic acid type water-based resin DL1201 is 0, and the addition amount of the anionic aliphatic water-based polyurethane resin ML-3009-3 is 420 g.

[0042] Comparative Example 2 Comparative Example 2 provides a waterproof leather finishing agent.

[0043] The difference between the comparative example and Example 3 is that the addition amount of the anionic aliphatic waterborne polyurethane resin ML-3009-3 is 0, and the addition amount of the anionic carboxylic acid waterborne resin DL1201 is 420 g.

[0044] Comparative Example 3 Comparative Example 3 provides a waterproof leather finishing agent.

[0045] The difference between the comparative example and Example 3 is that the addition amount of the anionic aliphatic waterborne polyurethane resin ML-3009-3 is 210 g, and the addition amount of the anionic carboxylic acid waterborne resin DL1201 is 210 g.

[0046] Comparative Example 4 Comparative Example 4 provides a waterproof leather finishing agent.

[0047] The difference between the comparative example and Example 3 is that the anionic aliphatic waterborne polyurethane resin ML-3009-3 is replaced by the anionic aromatic waterborne polyurethane resin F0415 (Yitian Chemical).

[0048] Comparative Example 5 Comparative Example 5 provides a waterproof leather finishing agent.

[0049] The difference between the comparative example and Example 3 is that the isocyanate curing agent is replaced by the epoxy resin curing agent 593.

[0050] Performance testing The waterproof leather finishing agents obtained in Examples 1-17 and Comparative Examples 1-5 were applied to leather surfaces to prepare leather samples. The wear resistance and waterproofness of the leather samples were tested. The results are shown in Table 3 below.

[0051] (1) The abrasion resistance of the leather finishing surface was tested according to the method described in GB / T 39507-2020 Leather-Physical and mechanical tests-Determination of abrasion resistance-Martin Dawdle abrasion method. After each 100 rubbing tests, the surface changes of the sample were observed, the number of wear points of the finishing surface was recorded, and the rubbing number at the time when 4 or more wear points appeared was recorded.

[0052] (2) Water contact angle: The water contact angle of the leather finishing surface was detected by a contact angle tester.

[0053] Table 3: Detection of use effect of waterproof leather finishing agent obtained in Examples 1-17 and Comparative Examples 1-5 According to the detection results in Table 3, the abrasion resistance of the leather sample prepared by using the waterproof leather finishing agent provided by Examples 1-17 is 1000-1300 times, and the water contact angle of the finishing surface is 124-158°; while the abrasion resistance of the leather sample prepared by using the waterproof leather finishing agent provided by Comparative Examples 1-4 is 900-1100 times, and the water contact angle of the finishing surface is 88-113°. Therefore, it is shown that by using specific weight ratios of anionic carboxylic acid type water-based resin and anionic aliphatic water-based polyurethane resin and isocyanate curing agent and other ingredients, a waterproof leather finishing agent with good abrasion resistance and waterproofness can be prepared, which can be used on the surface of leather to effectively avoid water stains on the leather after water cutting, affecting the quality of the leather.

[0054] According to the detection results of Examples 1-8, the abrasion resistance of the leather sample prepared by using the waterproof leather finishing agent provided by Examples 2-4 and Example 7 is 1100 times, and the water contact angle of the finishing surface is 133-141° (≥130°); while the abrasion resistance of the leather sample prepared by using the waterproof leather finishing agent provided by Examples 1, Examples 5-6 and Example 8 is 1100 times, and the water contact angle of the finishing surface is 124-129°. Therefore, it is shown that by further controlling the weight ratio of anionic carboxylic acid type water-based resin and anionic aliphatic water-based polyurethane resin in the range of (5-7): 1 and adding an amount of 35-45 parts, the waterproof performance of the waterproof leather finishing agent prepared is better.

[0055] The test results of Examples 3 and 9-16 show that the wear resistance of the leather samples prepared using the waterproof leather finishing agents provided in Examples 3 and 9-10 (using Uahard BL2002, xyh001 or BL-936 as a curing agent) is 1000-1100 times, and the water contact angle of the coated surface is 130-141°; the wear resistance of the leather samples prepared using the waterproof leather finishing agents provided in Examples 15-16 (using Uahard BL2002 and BL-936 in a weight ratio of 1:0.2 or BL-936 and xyh001 in a weight ratio of 1:0.2 as a curing agent) is 1100-1200 times, and the water contact angle of the coated surface is 145-147°; and the wear resistance of the leather samples prepared using the waterproof leather finishing agents provided in Examples 11-14 (using Uahard BL2002 and BL-936 in a weight ratio of 1:0.2 or BL-936 and xyh001 in a weight ratio of 1:0.2 as a curing agent) is 145-147°. The leather sample prepared using Uahard BL2002 and XYH001 as curing agents exhibited an abrasion resistance of 1,300 times, and a water contact angle of 152-158° on the coated surface. Therefore, this application demonstrates that the waterproof leather finishing agent produced by further using Uahard BL2002 and XYH001 as curing agents in a weight ratio of 1:1 (0.15-0.4) exhibits even better abrasion resistance and water resistance.

[0056] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A waterproof leather finishing agent, characterized in that: The invention comprises the following components in parts by weight: 30-50 parts of resin, 1.5-3 parts of thickening and leveling agent, 0.5-1.5 parts of wetting and leveling agent, 2-5 parts of isocyanate curing agent, 0.5-1 part of wax emulsion, 0.5-0.7 part of defoaming agent and 70-80 parts of water; The resin comprises an anionic carboxylic acid type waterborne resin and an anionic aliphatic waterborne polyurethane resin in a weight ratio of (4-8):

1.

2. The waterproof leather finishing agent according to claim 1, characterized in that The waterproof leather finishing agent comprises the following components in parts by weight: 35-45 parts of resin, 1.5-3 parts of thickening and leveling agent, 0.5-1.5 parts of wetting and leveling agent, 3-4 parts of isocyanate curing agent, 0.5-1 part of wax emulsion, 0.5-0.7 part of defoaming agent and 70-80 parts of water.

3. The waterproof leather finishing agent according to claim 1, characterized in that The weight ratio of the anionic carboxylic acid type waterborne resin to the anionic aliphatic waterborne polyurethane resin is (5-7):

1.

4. The waterproof leather finishing agent according to claim 1, characterized in that The isocyanate curing agent is selected from one or more of Uahard BL2002, HW 2100 CN, xyh001 and BL-936.

5. The waterproof leather finishing agent according to claim 4, characterized in that The isocyanate curing agent is a mixture of Uahard BL2002 and xyh001; the weight ratio of Uahard BL2002 to xyh001 is 1:(0.15-0.4).

6. The waterproof leather finishing agent according to claim 1, characterized in that The thickening and leveling agent is of polyurethane type and is selected from one or more of 635 TDS, QSC-6410, UH-420, UH-752 and UH-756vf.

7. The waterproof leather finishing agent according to claim 1, characterized in that The wetting and leveling agent is selected from one or more of YMT-328, HZ-1336, BYK-300, TEGO Glide 410, TEGO Glide 450 and TEGO Glide 100.

8. The method for preparing the waterproof leather finishing agent according to any one of claims 1 to 7, characterized in that: The following steps are involved: Under stirring, anionic carboxylic acid type water-based resin, wax emulsion, defoaming agent, anionic aliphatic water-based polyurethane resin, isocyanate curing agent, thickening and leveling agent, and wetting and leveling agent are added to water in sequence, and stirred evenly to obtain a waterproof leather finishing agent.

9. The method for preparing the waterproof leather finishing agent according to claim 8, characterized in that: The time interval for adding the adjacent components is 5-30 minutes.

Images