Silane coupling agent modified leather waterproof fatliquor and preparation method thereof

Abstract

The invention discloses a silane coupling agent modified leather waterproof fatliquor. The leather waterproof fatliquor is prepared from the following components in parts by mass through reaction: 80 to 120 parts of wool fat, 20 to 40 parts of diol amine, 20 to 60 parts of anhydride compounds, 10 to 70 parts of a silane coupling agent, 25 to 45 parts of a sulfonating agent and 0.1 to 5 parts of a catalyst. Compared with the prior art, the leather fatliquor has the advantages that (1) the leather fatliquor has multiple functions: the leather fatliquor integrates waterproof and soft properties, so that the fatliquor leather is soft and plump, the mechanical property of the leather is improved, and meanwhile, the leather fatliquor has good waterproof performance; (2) safety and environmental protection: no organic solvent is used in the preparation process, water is used as a main dispersion medium during fat liquoring, and the fat liquoring agent does not contain fluorocarbon and does not need chromium powder for fixation; (3) the preparation process is simple, and the preparation process is simple to operate and easy to popularize.

Description

Technical Field

[0001] The invention relates to a fatliquor, and more particularly to a leather waterproof fatliquor modified by a silane coupling agent. Background Art

[0002] Fatliquoring is a very important processing step in the leather production process, which has a great impact on the appearance and quality of leather. With the improvement of people's living standards, the requirements for leather products are getting higher and higher. It is no longer limited to the basic use functions of leather, but also pays attention to the waterproof, antibacterial and flame retardant properties of leather during use. The collagen fibers in leather have many hydrophilic groups and a large number of pores, which makes the leather easy to absorb water. In order to improve the physical and mechanical properties of leather and give leather a certain waterproof property, it is necessary to use a waterproof fatliquoring agent with good waterproof effect for fatliquoring.

[0003] At present, although the commonly used polyacrylic acid fatliquor has a waterproof function, chromium powder needs to be used to fix and seal the hydrophilic group during the fatliquor process, and hexavalent chromium seriously pollutes the environment. Fluorinated fatliquors have excellent waterproof effect, and the leather has a "three-proof" effect after treatment, but the leather has a hard feel after fatliquor. At the same time, fluorocarbon compounds are difficult to degrade, easily pollute the ecological environment, and endanger human health. In addition, most waterproof fatliquors have complex preparation processes and high costs, and a large amount of organic solvents are used in the preparation process, which pollutes the environment. Summary of the invention

[0004] In view of the shortcomings of the prior art, the object of the present invention is to provide a leather waterproof fatliquor modified by a silane coupling agent.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A silane coupling agent modified leather waterproof fatliquor,

[0007] It comprises the following mass parts:

[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 to 140 mgKOH / g and a saponification value of 100 to 160 mgKOH / g.

[0026] As another object of the present invention, a method for preparing a fatliquor is provided:

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

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

[0029] Step 3: After the reaction of step 2 is completed, add silane coupling agent and catalyst to react; reaction conditions: reaction temperature is 70-100°C, reaction time is 3-5h, and vacuum is drawn;

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

[0031] In the steps 1 and 3, the pressure of the vacuum system is ≤ 0.02 MPa.

[0032] The reaction schematic route of the present invention is as follows:

[0033]

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

[0035] (1) Multifunctional: It combines waterproof and soft properties in one, which can make the leather soft and plump after fat addition, improve its mechanical properties, and at the same time have good waterproof properties.

[0036] (2) Safety and environmental protection: No organic solvents are used in the preparation process, water is used as the main dispersion medium during greasing, the greasing agent does not contain fluorocarbons, and chromium powder is not required for fixation.

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

[0038] Embodiment 1

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

[0040] (2): After the reaction in step (1) is completed, the system is cooled to 95°C, 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 unchanged, add 44 parts of hexadecyltrimethoxysilane and 0.5 parts of p-toluenesulfonic acid, and conduct vacuum reaction 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 is added and reacted for 1 hour, and then 188 parts of distilled water are added. The temperature is kept constant and the reaction is continued for 3 hours to obtain a waterproof fatliquor.

[0043] Embodiment 2

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

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

[0046] (3): After the reaction in step (2) is completed, keep the system temperature unchanged, add 35 parts of dodecyltrimethoxysilane and 0.5 parts of p-toluenesulfonic acid, and conduct vacuum reaction 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, and then 194 parts of distilled water are added. The temperature is kept constant and the reaction is continued for 3 hours to obtain a waterproof fatliquor.

[0048] Embodiment 3

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

[0050] (2): After the reaction in step (1) is completed, the system is cooled to 90°C, 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, 54 parts of hexadecyltrimethoxysilane and 0.4 parts of p-toluenesulfonic acid are added, and the reaction is carried out in a vacuum for 5 hours;

[0052] (4): After the reaction of step (3) is completed, the system temperature is kept unchanged, 26 parts of anhydrous sodium sulfite is added and reacted for 1 hour, and then 166 parts of distilled water are added. The temperature is controlled unchanged and the reaction is continued for 3 hours to obtain a waterproof fatliquor.

[0053] Embodiment 4

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

[0055] (2): After the reaction in step (1) is completed, the system is cooled to 90°C, 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 mixture is vacuumed and reacted 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, and then 227 parts of distilled water are added. The temperature is kept constant and the reaction is continued for 3 hours to obtain a waterproof fatliquor.

[0058] Comparative Example: Lanolin (lanolin fatliquor not modified with silane coupling agent)

[0059] Take the post-fat-liquoring process of sheepskin chrome-tanned leather as an example:

[0060]

[0061]

[0062] The fatliquor of the embodiment and comparative example was added, and the obtained leather was tested for leather surface water contact angle, thickening rate, tensile strength, tear strength and elongation at break according to QB / T2710-2005, QB / T4198-2011 and QB / T2709-2005.

[0063] Water contact angle test on leather surface:

[0064] Water contact angle on leather surface after fatliquor Contact angle after 30 minutes Embodiment 1 128.8 120.6 Embodiment 2 125.6 119.8 Embodiment 3 126.9 120.2 Embodiment 4 128.4 120.4 Comparative Example 103.1 0

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

[0066]

[0067] The above tests show that the fatliquor prepared by the present invention has a good fatliquor effect on leather after being added to leather, and can effectively improve the mechanical properties of leather. At the same time, it has a good waterproof effect and has hydrophobic consistency and durability.

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

[0069] (1) Multifunctional: It combines waterproof and soft properties in one, which can make the leather soft and plump after fat addition, improve its mechanical properties, and at the same time have good waterproof properties.

[0070] (2) Safety and environmental protection: No organic solvents are used in the preparation process, water is used as the main dispersion medium during greasing, the greasing agent does not contain fluorocarbons, and chromium powder is not required for fixation.

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

[0072] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A silane coupling agent modified leather waterproof fatliquor, characterized in that: It comprises the following mass parts: 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 to 5 parts.

2. The leather waterproof fatliquor modified by a silane coupling agent according to claim 1, characterized in that: The diolamine is diethanolamine.

3. The leather waterproof fatliquor modified by a silane coupling agent according to claim 1, characterized in that: The acid anhydride compound is maleic anhydride.

4. The leather waterproof fatliquor modified by a silane coupling agent according to claim 1, characterized in that: The sulfonating agent is anhydrous sodium sulfite.

5. The leather waterproof fatliquor modified by a silane coupling agent according to claim 1, characterized in that: The catalyst is p-toluenesulfonic acid, phosphoric acid or boric acid.

6. The leather waterproof fatliquor modified by a silane coupling agent according to claim 1, characterized in that: The silane coupling agent is hexadecyltrimethoxysilane, dodecyltrimethoxysilane or octyltrimethoxysilane.

7. The leather waterproof fatliquor modified by a silane coupling agent according to claim 1, characterized in that: The acid value of the lanolin is 30 to 140 mgKOH / g, and the saponification value is 100 to 160 mgKOH / g.

8. The method for preparing a waterproof leather fatliquor according to any one of claims 1 to 7, characterized in that: Step 1: Mix lanolin and diolamine for amidation reaction; reaction conditions: reaction temperature is 100-150°C, reaction time is 3-6h, and vacuum is applied. Step 2: After the reaction of step 1 is completed, maleic anhydride is added as a catalyst to carry out a monoesterification reaction; reaction conditions: reaction temperature is 80-100°C, and reaction time is 2-4h; Step 3: After the reaction of step 2 is completed, add silane coupling agent and catalyst to react; reaction conditions: reaction temperature is 70-100°C, reaction time is 3-5h, and vacuum is drawn; Step 4: After the reaction in step 3 is completed, anhydrous sodium sulfite is added to carry out sulfonation reaction, and water is added during the process to adjust the solid content to 40% to 60%; reaction conditions: reaction temperature is 70 to 100° C., and reaction time is 3 to 5 hours.

9. The method for preparing a silane coupling agent-modified leather waterproof fatliquor according to claim 8, characterized in that: In the steps 1 and 3, the pressure of the vacuum system is ≤ 0.02 MPa.

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