Fluorine-containing cage-type silsesquioxane nano-tanning agent and preparation method thereof

Abstract

The invention discloses a preparation method of a fluorine-containing cage-type silsesquioxane nano-tanning agent. The method comprises the following steps: 1. adding 0.32 to 0.64 parts of sodium lauryl sulfate and 24 to 48 parts of distilled water into a flask, then heating the water bath to 50° C. to 70° C., and stirring at a rotation speed of 300 to 400 r / min until dissolved; then weighing 0.16 to 0.32 parts of vinyl cage-type silsesquioxane, dissolving it in 1.6 to 3.2 parts of tetrahydrofuran, pouring the mixture into a flask, and stirring for 15 to 20 minutes; weighing 6 to 25 parts of a methacrylic acid aqueous solution and 20 to 30 parts of an initiator aqueous solution, adding the mixture to the flask in three times, and reacting at a constant temperature; and 2.5 to 12 parts of trifluoroethyl methacrylate in 5 to 24 parts of tetrahydrofuran, slowly adding the mixture dropwise into the flask obtained in step 1, and reacting at a constant temperature for 2 to 3 hours to obtain the fluorine-containing cage-type silsesquioxane nano-tanning agent.

Description

Technical Field

[0001] The invention belongs to the technical field of synthetic methods for leather tanning agents, and in particular relates to a fluorine-containing cage-type silsesquioxane nano-tanning agent, and also relates to a preparation method of the fluorine-containing cage-type silsesquioxane nano-tanning agent. Background Art

[0002] The leather industry is closely linked to human life and the development of the national economy. Tanning agents are key ingredients in the leather processing process, reacting chemically with the collagen fibers of raw hides to transform them into leather. Chrome tanning agents are the most widely used, endowing leather with excellent physical and chemical properties. However, studies have shown that Cr(III) used in the leather-making process is easily oxidized to Cr(VI), a potentially carcinogenic substance, posing a health hazard. Furthermore, chrome tanning agents have a low absorption rate, resulting in large amounts of chromium-containing waste that is difficult to discharge and dispose of, causing serious environmental pollution. Therefore, the development of environmentally friendly, chrome-free tanning agents is imperative.

[0003] Polyhedral oligomeric silsesquioxanes (POSS) are a class of organic-inorganic hybrid materials with a highly symmetrical nanoscale cubic cage framework. The inorganic framework of their core is composed of Si-O-Si, which exhibits excellent stability, mechanical properties, and oxidation resistance. Each vertex of the periphery possesses active sites that can be freely modified, allowing for flexible design of the molecular structure to impart reactivity and functionality as needed. Previous studies have modified POSS with carboxyl groups to design a series of polycarboxyl POSS composite tanning agents for leather cleaning. These compounds possess a unique multi-side chain structure that significantly increases the number of active side chain groups, increasing the number of binding sites with leather collagen and enhancing the tanning effect. However, the large number of carboxyl groups also makes the composite tanning agent too hydrophilic, making it prone to surface over-tanning, resulting in a stiff feel for the finished leather and reducing its commercial value. Summary of the Invention

[0004] The first object of the present invention is to provide a method for preparing a fluorine-containing cage-type silsesquioxane nano-tanning agent, so as to solve the problem that the existing method uses a large amount of carboxyl groups to make the composite tanning agent too hydrophilic, resulting in the surface of the finished leather being easily over-tanned and having a stiff feel, thereby reducing its commercial value.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: a method for preparing a fluorine-containing cage-type silsesquioxane nano-tanning agent, which is specifically implemented according to the following steps:

[0006] Step 1: First, add 0.32 parts to 0.64 parts of sodium lauryl sulfate and 24 parts to 48 parts of distilled water to a flask by weight, then raise the water bath to 50°C-70°C and stir at a speed of 300 r / min-400 r / min until dissolved; then weigh 0.16 parts to 0.32 parts of vinyl cage silsesquioxane and dissolve it in 1.6 parts to 3.2 parts of tetrahydrofuran, pour it into the flask and stir for 15 min-20 min; finally, weigh 6 parts to 25 parts of methacrylic acid aqueous solution and 20 parts to 30 parts of initiator aqueous solution and add them to the flask in three times, and react at a constant temperature of 50°C-70°C for 2 h-3 h;

[0007] Step 2: dissolve 2.5 to 12 parts of trifluoroethyl methacrylate in 5 to 24 parts of tetrahydrofuran and slowly add the solution dropwise to the flask obtained in step 1. After constant temperature reaction for 2 to 3 hours, the mixture is naturally cooled to room temperature to obtain a fluorine-containing cage-type silsesquioxane nano-tanning agent.

[0008] As a preferred technical solution of the present invention, in step 1, the flask is a three-necked flask.

[0009] As a preferred technical solution of the present invention, in step 2, the mass fraction of the methacrylic acid aqueous solution is 45%.

[0010] As a preferred technical solution of the present invention, in step 2, the slow dropwise addition is specifically 5 mL / h to 8 mL / h.

[0011] The second object of the present invention is to provide a fluorine-containing cage-type silsesquioxane nano-tanning agent to solve the problem that the existing method uses a large amount of carboxyl groups to make the composite tanning agent too hydrophilic, resulting in the leather surface being easily over-tanned and having a stiff feel, thereby reducing its commercial value.

[0012] In order to achieve the above object, the technical solution adopted by the present invention is: the fluorine-containing cage-type silsesquioxane nano-tanning agent is prepared by the preparation method of the above-mentioned fluorine-containing cage-type silsesquioxane nano-tanning agent.

[0013] The beneficial effects of the present invention are as follows: the fluorinated caged silsesquioxane nanotanning agent prepared by the preparation method of the fluorinated caged silsesquioxane nanotanning agent of the present invention greatly improves the surface activity of the composite system due to the introduction of the hydrophobic short fluorocarbon chain monomer trifluoroethyl methacrylate, thereby significantly enhancing the permeability of the polycarboxyl POSS composite tanning agent, improving its filling property, making the finished leather fuller and firmer, and the shrinkage temperature of the single tanning can reach 75.3°C. DETAILED DESCRIPTION

[0014] The technical solution of the present invention is further described in detail below with reference to specific embodiments.

[0015] Studies have shown that this problem can be improved by introducing hydrophobic monomers into the polymer, thereby improving the softness and hydrophobicity of the leather.

[0016] Fluorinated polymers have excellent chemical stability, thermal stability and low surface energy. At the same time, studies have found that short fluorocarbon chain materials with less than or equal to four carbon atoms have minimal bioaccumulation and also have high surface activity. Therefore, the use of short fluorocarbon chain materials is more in line with the original intention of being environmentally friendly. The present invention reacts methacrylic acid with a vinyl-containing POSS monomer and then introduces a hydrophobic monomer trifluoroethyl methacrylate to prepare a fluorine-containing cage-type silsesquioxane nanotanning agent. The introduction of fluorine-containing monomers greatly improves the surface activity of the composite system, enhances its permeability, reduces problems such as surface over-tanning, and makes the finished leather softer, fuller and firmer.

[0017] The preparation method of the fluorine-containing cage-type silsesquioxane nano-tanning agent of the present invention is specifically implemented according to the following steps:

[0018] Step 1: First, add 0.32 to 0.64 parts of sodium lauryl sulfate and 24 to 48 parts of distilled water to a three-necked flask according to mass parts, then raise the water bath to 50°C-70°C and stir at a speed of 300 r / min-400 r / min until dissolved; then weigh 0.16 to 0.32 parts of vinyl cage silsesquioxane (i.e., POSS-Vi, prepared by hydrolysis and condensation reaction of vinyltrimethoxysilane as raw material) and dissolve it in 1.6 to 3.2 parts of tetrahydrofuran, and pour it into the three-necked flask and stir for 15 min-20 min; finally, weigh 6 to 25 parts of methacrylic acid aqueous solution and 20 to 30 parts of initiator aqueous solution (the initiator aqueous solution is prepared by dissolving 1.6 parts of ammonium persulfate APS and 0.4 parts of sodium bisulfite RH with 10 times the mass parts of distilled water, respectively) and add them to the flask three times, and react at a constant temperature of 50°C-70°C for 2 h-3 h;

[0019] Step 2: dissolve 2.5 to 12 parts of trifluoroethyl methacrylate in 5 to 24 parts of tetrahydrofuran and add the solution dropwise to the three-necked flask obtained in step 1 at a rate of 5 mL / h to 8 mL / h. After the reaction is carried out at a constant temperature for 2 to 3 hours, the solution is naturally cooled to room temperature to obtain a fluorine-containing cage-type silsesquioxane nano-tanning agent.

[0020] The fluorinated caged silsesquioxane nanotanning agent prepared by the preparation method of the fluorinated caged silsesquioxane nanotanning agent of the present invention greatly improves the surface activity of the composite system due to the introduction of the hydrophobic short fluorocarbon chain monomer trifluoroethyl methacrylate, thereby significantly enhancing the permeability of the polycarboxyl POSS composite tanning agent and improving its filling property, making the finished leather fuller and firmer, and the shrinkage temperature of the single tanning can reach 75.3°C.

[0021] Example 1

[0022] The preparation method of the fluorine-containing cage-type silsesquioxane nano-tanning agent of the present invention is specifically implemented according to the following steps:

[0023] Step 1: First, add 0.32 parts of sodium lauryl sulfate and 24 parts of distilled water to a three-necked flask according to mass parts, then raise the water bath to 50 ° C and stir at 300 r / min until dissolved; then weigh 0.16 parts of vinyl cage silsesquioxane and dissolve it in 1.6 parts of tetrahydrofuran, pour it into the three-necked flask and stir for 15 minutes; finally, weigh 6 parts of 45% methacrylic acid aqueous solution and 20 parts of initiator aqueous solution and add them to the flask in three times, and react at a constant temperature of 50 ° C for 2 hours;

[0024] Step 2: dissolve 2.5 parts of trifluoroethyl methacrylate in 5 parts of tetrahydrofuran and add dropwise to the three-necked flask obtained in step 1 at a rate of 5 mL / h. After constant temperature reaction for 2 hours, cool naturally to room temperature to obtain a fluorine-containing cage-type silsesquioxane nano-tanning agent.

[0025] When used in leather tanning process, the shrinkage temperature of tanning alone can reach 72 ℃.

[0026] Example 2

[0027] The preparation method of the fluorine-containing cage-type silsesquioxane nano-tanning agent of the present invention is specifically implemented according to the following steps:

[0028] Step 1: First, add 0.64 parts of sodium lauryl sulfate and 48 parts of distilled water to a three-necked flask according to mass parts, then heat the water bath to 70°C and stir at 400 r / min until dissolved; then weigh 0.32 parts of vinyl cage silsesquioxane and dissolve it in 3.2 parts of tetrahydrofuran, pour it into the three-necked flask and stir for 20 minutes; finally, weigh 25 parts of 45% methacrylic acid aqueous solution and 30 parts of initiator aqueous solution and add them to the flask in three times, and react at a constant temperature of 70°C for 3 hours;

[0029] Step 2: dissolve 12 parts of trifluoroethyl methacrylate in 24 parts of tetrahydrofuran and add the solution dropwise to the three-necked flask obtained in step 1 at a rate of 8 mL / h. After the reaction is carried out at a constant temperature for 3 hours, the mixture is naturally cooled to room temperature to obtain a fluorine-containing cage-type silsesquioxane nano-tanning agent.

[0030] When used in leather tanning process, the shrinkage temperature of tanning alone can reach 73.1 ℃.

[0031] Example 3

[0032] The preparation method of the fluorine-containing cage-type silsesquioxane nano-tanning agent of the present invention is specifically implemented according to the following steps:

[0033] Step 1: First, add 0.48 parts of sodium lauryl sulfate and 36 parts of distilled water to a three-necked flask according to mass parts, then heat the water bath to 60°C and stir at 350 r / min until dissolved; then weigh 0.24 parts of vinyl cage silsesquioxane and dissolve it in 2.5 parts of tetrahydrofuran, pour it into the three-necked flask and stir for 18 minutes; finally, weigh 15 parts of 45% methacrylic acid aqueous solution and 25 parts of initiator aqueous solution and add them to the flask in three times, and react at a constant temperature of 60°C for 2.5 hours;

[0034] Step 2: dissolve 11 parts of trifluoroethyl methacrylate in 14 parts of tetrahydrofuran and add dropwise to the three-necked flask obtained in step 1 at a rate of 7 mL / h. After constant temperature reaction for 2.5 hours, cool naturally to room temperature to obtain a fluorine-containing cage-type silsesquioxane nano-tanning agent.

[0035] When used in leather tanning process, the shrinkage temperature of tanning alone can reach 75.3 ℃.

[0036] Example 4

[0037] The preparation method of the fluorine-containing cage-type silsesquioxane nano-tanning agent of the present invention is specifically implemented according to the following steps:

[0038] Step 1: First, add 0.55 parts of sodium lauryl sulfate and 29 parts of distilled water to a three-necked flask according to mass parts, then heat the water bath to 55 ° C and stir at 330 r / min until dissolved; then weigh 0.22 parts of vinyl cage silsesquioxane and dissolve it in 2.3 parts of tetrahydrofuran, pour it into the three-necked flask and stir for 17 minutes; finally, weigh 10 parts of 45% methacrylic acid aqueous solution and 22 parts of initiator aqueous solution and add them to the flask in three times, and react at a constant temperature of 55 ° C for 3 hours;

[0039] Step 2: dissolve 4 parts of trifluoroethyl methacrylate in 10 parts of tetrahydrofuran and add dropwise to the three-necked flask obtained in step 1 at a rate of 6 mL / h. After constant temperature reaction for 3 hours, naturally cool to room temperature to obtain a fluorine-containing cage-type silsesquioxane nano-tanning agent.

[0040] When used in leather tanning process, the shrinkage temperature of tanning alone can reach 71.7 ℃.

[0041] Example 5

[0042] The preparation method of the fluorine-containing cage-type silsesquioxane nano-tanning agent of the present invention is specifically implemented according to the following steps:

[0043] Step 1: First, add 0.6 parts of sodium lauryl sulfate and 40 parts of distilled water to a three-necked flask according to mass parts, then heat the water bath to 65 ° C and stir at 380 r / min until dissolved; then weigh 0.3 parts of vinyl cage silsesquioxane and dissolve it in 2.9 parts of tetrahydrofuran, pour it into the three-necked flask and stir for 19 minutes; finally, weigh 23 parts of 45% methacrylic acid aqueous solution and 28 parts of initiator aqueous solution and add them to the flask in three times, and react at a constant temperature of 65 ° C for 3 hours;

[0044] Step 2: dissolve 11 parts of trifluoroethyl methacrylate in 22 parts of tetrahydrofuran and add dropwise to the three-necked flask obtained in step 1 at a rate of 7 mL / h. After constant temperature reaction for 3 hours, cool naturally to room temperature to obtain a fluorine-containing cage-type silsesquioxane nano-tanning agent.

[0045] When used in leather tanning process, the shrinkage temperature of tanning alone can reach 73.6 ℃.

[0046] The foregoing description shows and describes several preferred embodiments of the invention. However, as previously stated, it should be understood that the invention is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Rather, the invention is applicable to various other combinations, modifications, and environments and is capable of modification within the scope of the inventive concept described herein, through the teachings above, or through techniques or knowledge in the relevant art. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the invention are intended to be within the scope of the appended claims.

Claims

1. A method for preparing a fluorine-containing cage-type silsesquioxane nano-tanning agent, characterized in that: Please follow the steps below to implement it: Step 1: First, add 0.32 parts to 0.64 parts of sodium lauryl sulfate and 24 parts to 48 parts of distilled water to a flask by weight, then raise the water bath to 50°C-70°C and stir at a speed of 300 r / min-400 r / min until dissolved; then weigh 0.16 parts to 0.32 parts of vinyl cage silsesquioxane and dissolve it in 1.6 parts to 3.2 parts of tetrahydrofuran, pour it into the flask and stir for 15 min-20 min; finally, weigh 6 parts to 25 parts of methacrylic acid aqueous solution and 20 parts to 30 parts of initiator aqueous solution and add them to the flask in three times, and react at a constant temperature of 50°C-70°C for 2 h-3 h; Step 2: dissolve 2.5 to 12 parts of trifluoroethyl methacrylate in 5 to 24 parts of tetrahydrofuran and slowly add the solution dropwise to the flask obtained in step 1. After constant temperature reaction for 2 to 3 hours, the mixture is naturally cooled to room temperature to obtain a fluorine-containing cage-type silsesquioxane nano-tanning agent.

2. The method for preparing the fluorine-containing cage-type silsesquioxane nano-tanning agent according to claim 1, wherein In step 1, the flask is a three-necked flask.

3. The preparation method of the fluorine-containing cage-type silsesquioxane nano-tanning agent according to claim 1, characterized in that, In step 1, the mass fraction of the methacrylic acid aqueous solution is 45%.

4. The method for preparing the fluorine-containing cage-type silsesquioxane nano-tanning agent according to claim 1, wherein In the step 2, the slow dropwise addition is specifically 5 mL / h to 8 mL / h.

5. Fluorine-containing cage-type silsesquioxane nano-tanning agent, characterized in that: The fluorine-containing cage-type silsesquioxane nano-tanning agent is prepared using the preparation method of any one of claims 1 to 4.