A silane coupling agent modified leather waterproof fatliquoring agent and a preparation method thereof

Abstract

This invention discloses a silane coupling agent modified leather waterproofing fatliquoring agent, which is reacted with the following components in parts by weight: lanolin: 80-120 parts, diolamine: 20-40 parts, acid anhydride compound: 20-60 parts, silane coupling agent: 10-70 parts, sulfonating agent: 25-45 parts, catalyst: 0.1-5 parts. Compared with the prior art, the advantages of this invention are: (1) Multifunctional: It combines waterproof and soft properties, which can make the fatliquoring leather soft and full, improve its mechanical properties, and at the same time have good waterproof performance. (2) Safe and environmentally friendly: No organic solvents are used in the preparation process. Water is used as the main dispersion medium during fatliquoring. The fatliquoring agent does not contain fluorocarbons and does not require chromium powder for fixation. (3) Simple preparation process: The preparation process is simple to operate and easy to promote.

Description

Technical Field

[0001] This invention relates to fatliquoring agents, and more specifically to a silane coupling agent modified leather waterproofing fatliquoring agent. Background Technology

[0002] Fatliquoring is a crucial processing step in leather production, significantly impacting the appearance and quality of the leather. As people's living standards improve, their demands for leather products are increasing, no longer limited to basic functional uses but also focusing on properties such as water resistance, antibacterial properties, and flame retardancy. The collagen fibers in leather contain many hydrophilic groups and numerous pores, making leather highly absorbent. To improve the physical and mechanical properties of leather and impart a certain degree of water resistance, it is necessary to use a waterproof fatliquoring agent with excellent water-repellent effects.

[0003] Currently, while commonly used polyacrylic acid fatliquoring agents offer waterproofing, the fatliquoring process requires the use of chromium powder to fix and seal hydrophilic groups, and hexavalent chromium causes severe environmental pollution. Fluorine-containing fatliquoring agents offer excellent waterproofing, giving leather a "three-proof" (waterproof, anti-fouling, and anti-repellent) effect, but the leather tends to feel stiffer after fatliquoring. Furthermore, fluorocarbons are difficult to degrade, easily polluting the environment and harming human health. In addition, most waterproof fatliquoring agents have complex and costly manufacturing processes, using large amounts of organic solvents, which pollute the environment. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a silane coupling agent-modified leather waterproofing and fatliquoring agent.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A silane coupling agent modified leather waterproofing and fatliquoring agent,

[0007] It is produced by reacting the following components by mass:

[0008] Lanolin: 80-120 parts

[0009] Diolamine: 20-40 parts

[0010] Acid anhydride compounds: 20–60 parts

[0011] Silane coupling agent: 10-70 parts

[0012] Sulfonating agent: 25-60 parts

[0013] Catalyst: 0.1 to 5 parts.

[0014] As a further improvement of the present invention

[0015] The diolamine is diethanolamine.

[0016] As a further improvement of the present invention

[0017] The acid anhydride compound is maleic anhydride.

[0018] As a further improvement of the present invention

[0019] The sulfonating agent is anhydrous sodium sulfite.

[0020] As a further improvement of the present invention

[0021] The catalyst is p-toluenesulfonic acid, phosphoric acid, or boric acid.

[0022] As a further improvement of the present invention

[0023] The silane coupling agent is hexadecyltrimethoxysilane, dodecyltrimethoxysilane, or octyltrimethoxysilane.

[0024] As a further improvement of the present invention

[0025] The lanolin has an acid value of 30–140 mg KOH / g and a saponification value of 100–160 mg KOH / g.

[0026] As another objective of this invention, a method for preparing a fatliquoring agent is provided:

[0027] Step 1: Mix lanolin and diolamine for amidation reaction; reaction conditions: reaction temperature 100-150℃, reaction time 3-6h, vacuum.

[0028] Step 2: After the reaction in Step 1 is completed, maleic anhydride is added and a catalyst is used to carry out the monoesterification reaction; reaction conditions: reaction temperature is 80-100℃, reaction time is 2-4h;

[0029] Step 3: After the reaction in Step 2 is completed, add silane coupling agent and catalyst to carry out the reaction; reaction conditions: reaction temperature is 70-100℃, reaction time is 3-5h, and vacuum is applied.

[0030] Step 4: After the reaction in Step 3 is completed, anhydrous sodium sulfite is added to carry out the sulfonation reaction. During the process, water is added to adjust the solid content to 40% to 60%. Reaction conditions: reaction temperature is 70 to 100℃, and reaction time is 3 to 5 hours.

[0031] In steps one and three, the pressure of the vacuum system is ≤0.02MPa.

[0032] The reaction pathway of this invention is illustrated below:

[0033]

[0034] Compared with the prior art, the advantages of the present invention are:

[0035] (1) Multifunctional: It combines waterproof and soft properties, which can make the fattened leather soft and full, improve its mechanical properties, and at the same time have good waterproof properties.

[0036] (2) Safe and environmentally friendly: No organic solvents are used in the preparation process. Water is the main dispersion medium when adding fat. The fat-adding agent does not contain fluorocarbons and does not require chromium powder for fixation.

[0037] (3) Simple preparation process: The preparation process is simple to operate and easy to promote. Detailed Implementation

[0038] Example 1

[0039] (1): Weigh 100 parts of lanolin (acid value: 133mgKOH / g; saponification value: 153mgKOH / g) and 27 parts of diethanolamine respectively, mix them, heat the system to 135℃, and react under vacuum for 5h;

[0040] (2): After the reaction in step (1) is completed, the system is cooled to 95°C, and 25 parts of maleic anhydride and 0.45 parts of p-toluenesulfonic acid are added and reacted for 3 hours.

[0041] (3): After the reaction in step (2) is completed, keep the system temperature constant, add 44 parts of hexadecyltrimethoxysilane and 0.5 parts of p-toluenesulfonic acid and react under vacuum for 4 hours;

[0042] (4): After the reaction in step (3) is completed, the system is cooled to 80°C, 33 parts of anhydrous sodium sulfite are added and reacted for 1 hour, then 188 parts of distilled water are added and the temperature is kept constant for another 3 hours to obtain a waterproof fatliquoring agent.

[0043] Example 2

[0044] (1): Weigh 100 parts of lanolin (acid value: 32mgKOH / g; saponification value: 107mgKOH / g) and 21 parts of diethanolamine respectively, mix them, heat the system to 130℃, and react under vacuum for 4h;

[0045] (2): After the reaction in step (1) is completed, the system is cooled to 90°C, and 35 parts of maleic anhydride and 0.5 parts of p-toluenesulfonic acid are added and reacted for 2.5 h.

[0046] (3): After the reaction in step (2) is completed, keep the system temperature constant, add 35 parts of dodecyltrimethoxysilane and 0.5 parts of p-toluenesulfonic acid and react under vacuum for 4 hours;

[0047] (4): After the reaction in step (3) is completed, the system is cooled to 80°C, 45 parts of anhydrous sodium sulfite are added and reacted for 1 hour, then 194 parts of distilled water are added and the temperature is kept constant for another 3 hours to obtain a waterproof fatliquoring agent.

[0048] Example 3

[0049] (1): Weigh 80 parts of lanolin (acid value: 133mgKOH / g; saponification value: 153mgKOH / g) and 22 parts of diethanolamine respectively, mix them, heat the system to 140℃, and react under vacuum for 5h;

[0050] (2): After the reaction in step (1) is completed, the system is cooled to 90°C, and 20 parts of maleic anhydride and 0.4 parts of p-toluenesulfonic acid are added and reacted for 3 hours.

[0051] (3): After the reaction in step (2) is completed, the temperature is lowered to 80°C, and 54 parts of hexadecyltrimethoxysilane and 0.4 parts of p-toluenesulfonic acid are added and the reaction is carried out under vacuum for 5 hours.

[0052] (4): After the reaction in step (3) is completed, keep the system temperature constant, add 26 parts of anhydrous sodium sulfite and react for 1 hour, then add 166 parts of distilled water, keep the temperature constant and continue to keep the reaction for 3 hours to obtain a waterproof fatliquoring agent.

[0053] Example 4

[0054] (1): Weigh 120 parts of lanolin (acid value: 32mgKOH / g; saponification value: 107mgKOH / g) and 25 parts of diethanolamine respectively, mix them, heat the system to 140℃, and react under vacuum for 5h;

[0055] (2): After the reaction in step (1) is completed, the system is cooled to 90°C, and 42 parts of maleic anhydride and 0.5 parts of p-toluenesulfonic acid are added and reacted for 3 hours.

[0056] (3): After the reaction in step (2) is completed, the temperature is raised to 100°C, 35 parts of dodecyltrimethoxysilane and 0.5 parts of p-toluenesulfonic acid are added and the reaction is carried out under vacuum for 5 hours.

[0057] (4): After the reaction in step (3) is completed, the system is cooled to 80°C, 54 parts of anhydrous sodium sulfite are added and reacted for 1 hour, then 227 parts of distilled water are added and the temperature is kept constant for another 3 hours to obtain a waterproof fatliquoring agent.

[0058] Comparative example: Lanolin (lanolin fatliquoring agent without silane coupling agent modification)

[0059] Taking the fatliquoring process after chrome tanning of sheepskin as an example:

[0060]

[0061]

[0062] The fatliquoring agents used in the examples and comparative examples were added, and the resulting leather was subjected to surface water contact angle test, thickening rate test, tensile strength test, tear strength test, and elongation at break test in accordance with QB / T2710-2005, QB / T4198-2011, and QB / T2709-2005.

[0063] Leather surface water contact angle test:

[0064] Example 1 128.8 120.6 Example 2 125.6 119.8 Example 3 126.9 120.2 Example 4 128.4 120.4 Comparative Example 103.1 0

[0065] Thickness test, tensile strength test, tear strength test, elongation at break test:

[0066]

[0067] The above tests demonstrate that the fatliquoring agent prepared in this invention, when added to leather, imparts excellent fatliquoring effects and effectively improves the leather's mechanical properties. It also exhibits good water resistance, consistent hydrophobicity, and durability.

[0068] Compared with the prior art, the advantages of the present invention are:

[0069] (1) Multifunctional: It combines waterproof and soft properties, which can make the fattened leather soft and full, improve its mechanical properties, and at the same time have good waterproof properties.

[0070] (2) Safe and environmentally friendly: No organic solvents are used in the preparation process. Water is the main dispersion medium when adding fat. The fat-adding agent does not contain fluorocarbons and does not require chromium powder for fixation.

[0071] (3) Simple preparation process: The preparation process is simple to operate and easy to promote.

[0072] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A silane coupling agent modified leather waterproofing and fatliquoring agent, characterized in that: It is produced by reacting the following components by mass: Lanolin: 80-120 parts Diolamine: 20-40 parts Acid anhydride compounds: 20-60 parts Silane coupling agent: 10-70 parts Sulfonating agent: 25-60 parts Catalyst: 0.1~5 parts; The acid anhydride compound is maleic anhydride; The sulfonating agent is anhydrous sodium sulfite; The catalyst is p-toluenesulfonic acid, phosphoric acid, or boric acid; The silane coupling agent is hexadecyltrimethoxysilane, dodecyltrimethoxysilane, or octyltrimethoxysilane; The preparation method is as follows: Step 1: Mix lanolin and diolamine for amidation reaction; Reaction conditions: reaction temperature 100-150℃, reaction time 3-6h, vacuum; Step 2: After the reaction in Step 1 is completed, maleic anhydride is added and a catalyst is used to carry out the monoesterification reaction; reaction conditions: reaction temperature is 80-100℃, reaction time is 2-4h; Step 3: After the reaction in Step 2 is completed, add silane coupling agent and catalyst to carry out the reaction; reaction conditions: reaction temperature is 70-100℃, reaction time is 3-5h, and vacuum is applied. Step 4: After the reaction in Step 3 is completed, anhydrous sodium sulfite is added to carry out the sulfonation reaction. During the process, water is added to adjust the solid content to 40% to 60%. Reaction conditions: reaction temperature is 70 to 100℃, and reaction time is 3 to 5 hours.

2. The silane coupling agent modified leather waterproofing and fatliquoring agent according to claim 1, characterized in that: The diolamine is diethanolamine.

3. The silane coupling agent modified leather waterproofing and fatliquoring agent according to claim 1, characterized in that: The lanolin has an acid value of 30–140 mg KOH / g and a saponification value of 100–160 mg KOH / g.

4. The silane coupling agent modified leather waterproofing and fatliquoring agent according to claim 1, characterized in that: In steps one and three, the pressure of the vacuum system is ≤0.02MPa.

Images