Environment-friendly shoemaking industry offset printing material treating agent and preparation method thereof
By using polysiloxane-polyurethane copolymer and modified nano-silica in offset printing materials, the problem of poor matching between offset printing materials and adhesives is solved, high peel strength and self-healing performance are achieved, and environmental pollution is reduced.
Patent Information
- Application Number
- CN202511171554.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-21
- Publication Date
- 2025-09-26
AI Technical Summary
Existing offset printing materials for the footwear industry are not well matched with adhesives, resulting in decreased peel strength, and traditional solvent-based treatment agents are harmful to the environment and human health.
Polysiloxane-polyurethane copolymer is used as the main component, which contains borate bonds and disulfide bonds. Modified nano-silica is used to improve the bonding strength and durability of the material through dynamic cross-linking and self-healing mechanisms.
It improves the matching degree between offset printing materials and adhesives, enhances the peel strength, and improves the tensile strength, compressive strength and durability of the material through the self-repair mechanism, reducing pollution to the environment.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of surface treatment agents, in particular to an environmentally friendly shoemaking offset printing material treatment agent and a preparation method thereof. Background Art
[0002] Shoe upper offset printing materials are the core material for upper decoration and brand logo printing. Primarily composed of adhesive, adhesive is used through the screen printing process to create a soft, crack-resistant printed layer on the shoe upper. Available in a wide variety of types with varying performance characteristics, adhesive is widely used in a variety of footwear, including athletic shoes, casual shoes, and running shoes. Adhesive is a specialized screen printing ink, based on polyurethane resin as its core ingredient, combined with acrylic thickeners and film-forming agents. Its molecular chains are activated by heat, penetrating the shoe material to form chemical bonds, ensuring a secure bond.
[0003] Polyurethane adhesives are widely used in packaging, construction, automotive, and other fields due to their excellent bonding properties, weather resistance, and chemical resistance. However, polyurethane adhesives, especially water-based ones, have high surface tension and poor wetting ability with hydrophobic shoe uppers, making it difficult to form a good bonding interface and resulting in insufficient bond strength.
[0004] Footwear offset printing material treatment agents are primarily applied to the surface of shoe upper offset printing materials to enhance the bond strength of the polyurethane adhesive to the offset printing material. Existing footwear material treatment agents are typically formulated with organic solvents (such as toluene, butanone, and acetone). These solvents are highly volatile and easily release volatile organic compounds (VOCs), posing a threat to the environment and human health. Therefore, there is a need for an environmentally friendly, water-based footwear offset printing material treatment agent. To date, the development of water-based footwear offset printing material treatment agents is still in its early stages, and few are available on the market. Furthermore, the compatibility between footwear offset printing materials, adhesives, and printing materials is poor, resulting in reduced peel strength. Summary of the Invention
[0005] The invention provides an environmentally friendly shoemaking offset printing material treating agent and a preparation method thereof, which can solve the problem in the prior art that the shoemaking offset printing material has a low matching degree with the adhesive and the offset printing, resulting in a decrease in peeling strength.
[0006] The purpose of the present invention can be achieved through the following technical solutions: An environmentally friendly shoemaking offset printing material treating agent comprises the following raw materials in parts by weight: 70-90 parts of waterborne polyurethane resin 6-10 parts of polysiloxane-polyurethane copolymer PDA@Nano-silica 2-5 parts 15-30 parts deionized water 1-3 parts defoaming agent 1-3 parts wetting agent 3-5 parts water-based polyurethane thickener The chain segments of the polysiloxane-polyurethane copolymer contain borate bonds and disulfide bonds.
[0007] Furthermore, the preparation method of the polysiloxane-polyurethane copolymer is: Isophorone isocyanate, polyether 210, bis(4-hydroxyphenyl) disulfide and hydroxypropyl-terminated polydimethylsiloxane are fully stirred at 40°C, heated to 70°C, dibutyltin dilaurate is added, and the reaction is carried out for 2-4 hours. Then, dimethylolpropionic acid and a chain extender containing a borate bond are added, and the reaction is carried out for 1-3 hours. Then, 1,4-butanediol and trimethylolpropane are added, and the reaction is continued for 100 minutes. The temperature is lowered to 40°C, triethylamine is added for neutralization for 30 minutes, and the temperature is lowered to 25°C. Finally, the polysiloxane-polyurethane copolymer is obtained by filtration, washing and drying.
[0008] Among them, the mass ratio of isophorone isocyanate, polyether 210, bis(4-hydroxyphenyl) disulfide, dihydroxy-terminated polysiloxane, and dibutyltin dilaurate is 10:22:(2-4):(2-4):(0.02-0.04):(1-3):(1-3):2:2.
[0009] The above steps use isophorone isocyanate and polyether 210 as raw materials, bis(4-hydroxyphenyl) disulfide and double-terminated hydroxyl polysiloxane as modifiers, dimethylolpropionic acid (DMPA) as a hydrophilic chain extender monomer, a chain extender containing a borate bond as a modifier, 1,4-butanediol (BDO) as a linear chain extender monomer, and trimethylolpropane (TMP) as a cross-linking chain extender monomer to obtain a polysiloxane-polyurethane copolymer.
[0010] Furthermore, the preparation method of the borate ester bond-containing chain extender is: 4-Hydroxyphenylboric acid was dissolved in tetrahydrofuran, and then glycerol and anhydrous magnesium sulfate were added. After mixing, the temperature was raised to 60° C., condensed and refluxed for 24 hours, and then cooled to 25° C., filtered, and vacuum distilled, washed, and dried to obtain a chain extender containing a borate ester bond.
[0011] The usage ratio of 4-hydroxyphenylboric acid, tetrahydrofuran and glycerol is 13.8 g:50-60 mL:18.6 g.
[0012] Furthermore, the preparation method of the PDA@ nano-silica is: Dopamine was dissolved in Tris buffer, nano-silica was added, and the mixture was stirred at room temperature for 7-10 hours. Finally, PDA@nano-silica was obtained by centrifugation, washing, and drying.
[0013] The dosage ratio of dopamine, Tris buffer and nano-silica is 2-4 g:50 mL:2 g.
[0014] Furthermore, the defoaming agent is a nonionic polyurethane defoaming agent, preferably a nonionic polyurethane defoaming agent including one or a combination of two or more of dihydroxypropyl octadecanoate, Span-60, dodecyl glycoside and polyether modified silicone defoaming agent.
[0015] Furthermore, the wetting agent is an organosilicon wetting agent, preferably BYK-154.
[0016] A method for preparing an environmentally friendly shoemaking offset printing material treating agent comprises the following steps: Adding a polysiloxane-polyurethane copolymer to deionized water and stirring to obtain a polysiloxane-polyurethane copolymer solution; dispersing PDA@nano-silica in deionized water to obtain a PDA@nano-silica dispersion; then adding the polysiloxane-polyurethane copolymer solution to an aqueous polyurethane resin, stirring for 30-50 minutes, adding the PDA@nano-silica dispersion, stirring for 40-60 minutes, and then adding a defoamer, a wetting agent and an aqueous polyurethane thickener. After stirring and mixing, filtering and packaging are performed to obtain a shoe offset printing material treating agent.
[0017] Beneficial effects of the present invention: 1. This invention innovatively incorporates a polysiloxane-polyurethane copolymer into the raw materials of the footwear offset printing material treatment agent. The polysiloxane-polyurethane copolymer's chain segments contain borate and disulfide bonds. This copolymer, which contains both hydrophilic segments (derived from the polar portion of the polyurethane and borate groups) and hydrophobic segments (derived from the polysiloxane), serves as a good medium between the water-based polyurethane adhesive and the footwear offset printing material, seamlessly integrating the two and improving peel strength. Both disulfide and borate bonds form a crosslinked network between polymer chains. The crosslinked network formed by the borate bonds enhances the material's strength and hardness, while the dynamic exchange reaction of the disulfide bonds improves the material's flexibility and enhances its tensile and compressive properties. The synergistic effect of these two bonds allows the material to not only repair its microstructure through bond reorganization after damage, but also restore its mechanical properties at a macroscopic level, effectively enhancing its self-healing ability and durability, thereby improving peel strength.
[0018] 2. The present invention also modifies nano-silica with polydopamine (PDA). The dopamine group can form dynamic cross-links with borate bonds through its catechol structure, giving the material self-healing properties and improving peel strength. After the nano-silica is modified with polydopamine, PDA@nano-silica can be more evenly dispersed in the raw material, which is conducive to the reinforcing effect of nano-silica. DETAILED DESCRIPTION
[0019] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.
[0020] The hydroxypropyl-terminated polydimethylsiloxane in the present invention was purchased from Shanghai MacLean Biochemical Technology Co., Ltd. with a CAS number of 104780-66-7.
[0021] Preparation Example 1 The preparation method of polysiloxane-polyurethane copolymer is: 10g of isophorone isocyanate, 22g of polyether 210, 2g of bis(4-hydroxyphenyl) disulfide, and 2g of hydroxypropyl-terminated polydimethylsiloxane were fully stirred at 40°C, heated to 70°C, added with 0.02g of dibutyltin dilaurate, and reacted for 2h. Then, 1g of dihydroxymethylpropionic acid and 1g of a borate-containing chain extender were added. After reacting for 1h, 2g of 1,4-butanediol and 2g of trimethylolpropane were added, and the reaction was continued for 100min. The mixture was cooled to 40°C, neutralized with triethylamine for 30min, cooled to 25°C, and finally filtered, washed, and dried to obtain a polysiloxane-polyurethane copolymer.
[0022] The preparation method of the chain extender containing borate ester bond is as follows: 13.8 g of 4-hydroxyphenylboronic acid was dissolved in 50 mL of tetrahydrofuran, and then 18.6 g of glycerol and anhydrous magnesium sulfate were added. After mixing, the temperature was raised to 60° C. and refluxed for 24 h. The mixture was then cooled to 25° C., filtered, and distilled under reduced pressure, washed, and dried to obtain a chain extender containing a borate ester bond.
[0023] Preparation Example 2 The preparation method of polysiloxane-polyurethane copolymer is: 10g of isophorone isocyanate, 22g of polyether 210, 3g of bis(4-hydroxyphenyl) disulfide, and 3g of hydroxypropyl-terminated polydimethylsiloxane were fully stirred at 40°C, heated to 70°C, added with 0.03g of dibutyltin dilaurate, and reacted for h. Then, 2g of dihydroxymethylpropionic acid and 2g of a borate-containing chain extender were added and reacted for 3h. Then, 2g of 1,4-butanediol and 2g of trimethylolpropane were added and the reaction was continued for 100min. The mixture was cooled to 40°C, neutralized with triethylamine for 30min, cooled to 25°C, and filtered, washed, and dried to obtain a polysiloxane-polyurethane copolymer.
[0024] The preparation method of the chain extender containing borate ester bond is the same as that of Preparation Example 1.
[0025] Preparation Example 3 The preparation method of polysiloxane-polyurethane copolymer is: 10g of isophorone isocyanate, 22g of polyether 210, 4g of bis(4-hydroxyphenyl)disulfide, and 4g of hydroxypropyl-terminated polydimethylsiloxane were fully stirred at 40°C, heated to 70°C, added with 0.04g of dibutyltin dilaurate, and reacted for 4h. Then, 3g of dihydroxymethylpropionic acid and 3g of a borate-containing chain extender were added. After reacting for 3h, 2g of 1,4-butanediol and 2g of trimethylolpropane were added, and the reaction was continued for 100min. The temperature was lowered to 40°C, triethylamine was added for neutralization for 30min, and the temperature was lowered to 25°C. Finally, the polysiloxane-polyurethane copolymer was obtained by filtration, washing, and drying.
[0026] The preparation method of the chain extender containing borate ester bond is the same as that of Preparation Example 1.
[0027] Comparative Example 1 This comparative example differs from Preparation Example 1 only in that bis(4-hydroxyphenyl)disulfide is omitted. The specific steps are as follows: 10g of isophorone isocyanate, 22g of polyether 210 and 2g of hydroxypropyl-terminated polydimethylsiloxane were fully stirred at 40°C, heated to 70°C, 0.02g of dibutyltin dilaurate was added, and the reaction was carried out for 2h. Then, 1g of dihydroxymethylpropionic acid and 1g of a chain extender containing a borate bond were added. After the reaction was carried out for 1h, 2g of 1,4-butanediol and 2g of trimethylolpropane were added, and the reaction was continued for 100min. The temperature was lowered to 40°C, triethylamine was added for neutralization for 30min, and the temperature was lowered to 25°C. Finally, the polysiloxane-polyurethane copolymer was obtained by filtration, washing and drying.
[0028] Comparative Example 2 The only difference between this comparative example and Preparation Example 1 is that the chain extender containing a borate ester bond is omitted. The specific steps are as follows: 10g of isophorone isocyanate, 22g of polyether 210, 2g of bis(4-hydroxyphenyl) disulfide, and 2g of hydroxypropyl-terminated polydimethylsiloxane were fully stirred at 40°C, heated to 70°C, added with 0.02g of dibutyltin dilaurate, and reacted for 2h. Then, 1g of dihydroxymethylpropionic acid was added and reacted for 1h. Then, 2g of 1,4-butanediol and 2g of trimethylolpropane were added and the reaction was continued for 100min. The temperature was lowered to 40°C, triethylamine was added for neutralization for 30min, and the temperature was lowered to 25°C. Finally, the polysiloxane-polyurethane copolymer was obtained by filtration, washing, and drying.
[0029] Comparative Example 3 The only difference between this comparative example and Preparation Example 1 is that bis(4-hydroxyphenyl) disulfide and the chain extender containing a borate ester bond are omitted. The specific steps are as follows: 10g of isophorone isocyanate, 22g of polyether 210 and 2g of hydroxypropyl-terminated polydimethylsiloxane were fully stirred at 40°C, heated to 70°C, 0.02g of dibutyltin dilaurate was added, and the reaction was carried out for 2h. Then, 1g of dihydroxymethylpropionic acid was added and the reaction was continued for 1h. Then, 2g of 1,4-butanediol and 2g of trimethylolpropane were added and the reaction was continued for 100min. The temperature was lowered to 40°C, triethylamine was added for neutralization for 30min, and the temperature was lowered to 25°C. Finally, the polysiloxane-polyurethane copolymer was obtained by filtration, washing and drying.
[0030] Comparative Example 4 The only difference between this comparative example and comparative example 3 is that the hydroxypropyl-terminated polydimethylsiloxane is omitted. The specific steps are as follows: 10 g of isophorone isocyanate and 22 g of polyether 210 were fully stirred at 40 ° C, heated to 70 ° C, added with 0.02 g of dibutyltin dilaurate, and reacted for 2 h. Then, 1 g of dimethylolpropionic acid was added and reacted for 1 h. Then, 2 g of 1,4-butanediol and 2 g of trimethylolpropane were added and the reaction was continued for 100 min. The temperature was lowered to 40 ° C, triethylamine was added for neutralization for 30 min, and the temperature was lowered to 25 ° C. Finally, the polyurethane copolymer was obtained by filtration, washing and drying.
[0031] Preparation Example 4 The preparation method of PDA@ nano-silica is: 2 g of dopamine was dissolved in 50 mL of Tris buffer, 2 g of nano-silica was added, and the mixture was stirred at room temperature for 7 h. Finally, PDA@nano-silica was obtained by centrifugation, washing, and drying.
[0032] Preparation Example 5 The preparation method of PDA@ nano-silica is: 4 g dopamine was dissolved in 50 mL Tris buffer, 2 g nano-silica was added, and the mixture was stirred at room temperature for 10 h. Finally, PDA@nano-silica was obtained by centrifugation, washing, and drying.
[0033] Example 1 An environmentally friendly shoemaking offset printing material treating agent comprises the following raw materials in parts by weight: 70 parts of waterborne polyurethane resin 6 parts of the polysiloxane-polyurethane copolymer prepared in Preparation Example 1 2 parts of PDA@ nano-silica prepared in Preparation Example 4 15 parts deionized water 1 part of defoaming agent Span-60 1 part of wetting agent BYK-154 3 parts water-based polyurethane thickener Its preparation method is: Adding a polysiloxane-polyurethane copolymer to deionized water and stirring to obtain a polysiloxane-polyurethane copolymer solution; dispersing PDA@nano-silica in deionized water to obtain a PDA@nano-silica dispersion; then adding the polysiloxane-polyurethane copolymer solution to an aqueous polyurethane resin, stirring for 30 minutes, adding the PDA@nano-silica dispersion, stirring for 40 minutes, and then adding a defoamer, a wetting agent and an aqueous polyurethane thickener. After stirring and mixing, filtering and packaging are performed to obtain a shoe offset printing material treating agent.
[0034] Example 2 An environmentally friendly shoemaking offset printing material treating agent comprises the following raw materials in parts by weight: 80 parts of waterborne polyurethane resin 8 parts of the polysiloxane-polyurethane copolymer prepared in Preparation Example 1 3.5 parts of PDA@ nano-silica prepared in Preparation Example 4 22.5 parts deionized water 3 parts of defoaming agent Span-60 3 parts of wetting agent BYK-154 5 parts water-based polyurethane thickener Its preparation method is: Adding a polysiloxane-polyurethane copolymer to deionized water and stirring to obtain a polysiloxane-polyurethane copolymer solution; dispersing PDA@nano-silica in deionized water to obtain a PDA@nano-silica dispersion; then adding the polysiloxane-polyurethane copolymer solution to an aqueous polyurethane resin, stirring for 30 minutes, adding the PDA@nano-silica dispersion, stirring for 40 minutes, and then adding a defoamer, a wetting agent and an aqueous polyurethane thickener. After stirring and mixing, filtering and packaging are performed to obtain a shoe offset printing material treating agent.
[0035] Example 3 An environmentally friendly shoemaking offset printing material treating agent comprises the following raw materials in parts by weight: 90 parts of waterborne polyurethane resin 10 parts of the polysiloxane-polyurethane copolymer prepared in Preparation Example 1 5 parts of PDA@ nano-silica prepared in Preparation Example 4 30 parts deionized water 3 parts of defoaming agent Span-60 3 parts of wetting agent BYK-154 4 parts water-based polyurethane thickener Its preparation method is: Adding a polysiloxane-polyurethane copolymer to deionized water and stirring to obtain a polysiloxane-polyurethane copolymer solution; dispersing PDA@nano-silica in deionized water to obtain a PDA@nano-silica dispersion; then adding the polysiloxane-polyurethane copolymer solution to an aqueous polyurethane resin, stirring for 30 minutes, adding the PDA@nano-silica dispersion, stirring for 40 minutes, and then adding a defoamer, a wetting agent and an aqueous polyurethane thickener. After stirring and mixing, filtering and packaging are performed to obtain a shoe offset printing material treating agent.
[0036] Example 4 An environmentally friendly shoemaking offset printing material treating agent comprises the following raw materials in parts by weight: 90 parts of waterborne polyurethane resin 10 parts of the polysiloxane-polyurethane copolymer prepared in Preparation Example 2 5 parts of PDA@ nano-silica prepared in Preparation Example 4 30 parts deionized water 3 parts of defoaming agent Span-60 3 parts of wetting agent BYK-154 4 parts water-based polyurethane thickener Its preparation method is: A polysiloxane-polyurethane copolymer is added to deionized water and stirred to obtain a polysiloxane-polyurethane copolymer solution; PDA@nanosilica is dispersed in deionized water to obtain a PDA@nanosilica dispersion; the polysiloxane-polyurethane copolymer solution is then added to an aqueous polyurethane resin and stirred for 50 minutes, followed by the addition of the PDA@nanosilica dispersion and stirring for 60 minutes. A defoamer, a wetting agent and an aqueous polyurethane thickener are then added, the mixture is stirred, filtered and packaged to obtain a shoe offset printing material treating agent.
[0037] Example 5 An environmentally friendly shoemaking offset printing material treating agent comprises the following raw materials in parts by weight: 90 parts of waterborne polyurethane resin 10 parts of the polysiloxane-polyurethane copolymer prepared in Preparation Example 3 5 parts of PDA@ nano-silica prepared in Preparation Example 5 30 parts deionized water 3 parts of defoaming agent Span-60 3 parts of wetting agent BYK-154 4 parts water-based polyurethane thickener Its preparation method is: Adding a polysiloxane-polyurethane copolymer to deionized water and stirring to obtain a polysiloxane-polyurethane copolymer solution; dispersing PDA@nano-silica in deionized water to obtain a PDA@nano-silica dispersion; then adding the polysiloxane-polyurethane copolymer solution to an aqueous polyurethane resin, stirring for 30 minutes, adding the PDA@nano-silica dispersion, stirring for 40 minutes, and then adding a defoamer, a wetting agent and an aqueous polyurethane thickener. After stirring and mixing, filtering and packaging are performed to obtain a shoe offset printing material treating agent.
[0038] Comparative Example 1 The only difference between this comparative example and Example 1 is that the polysiloxane-polyurethane copolymer prepared in Preparation Example 1 is replaced by an equal amount of the polysiloxane-polyurethane copolymer prepared in Comparative Example 1.
[0039] Comparative Example 2 The only difference between this comparative example and Example 1 is that the polysiloxane-polyurethane copolymer prepared in Preparation Example 1 is replaced by an equal amount of the polysiloxane-polyurethane copolymer prepared in Comparative Example 2.
[0040] Comparative Example 3 The only difference between this comparative example and Example 1 is that the polysiloxane-polyurethane copolymer prepared in Preparation Example 1 is replaced by an equal amount of the polysiloxane-polyurethane copolymer prepared in Comparative Example 3.
[0041] Comparative Example 4 The only difference between this comparative example and Example 1 is that the polyurethane copolymer prepared in Preparation Example 1 is replaced by an equal amount of the polyurethane copolymer prepared in Comparative Example 4.
[0042] Comparative Example 5 The only difference between this comparative example and Example 1 is that the PDA@nanosilica prepared in Preparation Example 4 is replaced by an equal amount of nanosilica.
[0043] The offset printing material was treated with the treating agents prepared in Examples 1-5 and Comparative Examples 1-5 and the water-based polyurethane adhesive. The initial peel strength (1 minute) and the later peel strength (3 days) of the finished substrate were tested in accordance with the provisions of "GB / T 19340-2014 Adhesives for Shoes and Bags". The test results are shown in Table 1.
[0044] Table 1 As can be seen from Table 1, the peel strength of the treatment agent prepared in the embodiment is higher than that of the comparative example. The peel strength of the treatment agents obtained in comparative examples 1-3 is lower than that of Example 1, indicating that both disulfide bonds and borate bonds can form a cross-linked network between polymer molecular chains. The cross-linked network formed by borate bonds can enhance the strength and hardness of the material, while the dynamic exchange reaction of disulfide bonds can make the material have better flexibility and improve its tensile and compressive properties. The synergistic effect of the two enables the material to not only repair the microstructure through bond reorganization after damage, but also restore the mechanical properties of the material on a macro scale, effectively enhancing the self-repair ability and durability of the material, thereby improving the peel strength.
[0045] Comparative Example 4 does not contain polysiloxane, and its peel strength is lower than that of Example 1, indicating that the hydrophobic segment (derived from polysiloxane) can serve as a good medium between the water-based polyurethane adhesive and the offset printing material of the shoemaking industry, perfectly integrating the two into one and improving the peel strength.
[0046] Comparative Example 5 does not contain PDA, and its peel strength is lower than that of Example 1, indicating that the dopamine group can form dynamic crosslinks with the borate bond through its catechol structure, giving the material self-healing properties and improving the peel strength. After the nano-silica is modified with polydopamine, PDA@nano-silica can be more evenly dispersed in the raw material, which is beneficial to the reinforcing effect of nano-silica.
[0047] The above disclosures are only a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.
Claims
1. An environmentally friendly shoemaking offset printing material treating agent, characterized in that: It includes the following raw materials in parts by weight: 70-90 parts of waterborne polyurethane resin 6-10 parts of polysiloxane-polyurethane copolymer PDA@Nano-silica 2-5 parts 15-30 parts deionized water 1-3 parts defoaming agent 1-3 parts wetting agent 3-5 parts water-based polyurethane thickener The chain segments of the polysiloxane-polyurethane copolymer contain borate bonds and disulfide bonds.
2. The environmentally friendly shoemaking offset printing material treating agent according to claim 1, characterized in that: The preparation method of the polysiloxane-polyurethane copolymer is: Isophorone isocyanate, polyether 210, bis(4-hydroxyphenyl) disulfide, and hydroxypropyl-terminated polydimethylsiloxane are fully stirred at 40°C, heated to 70°C, and dibutyltin dilaurate is added. The mixture is reacted for 2-4 hours. Dimethylolpropionic acid and a chain extender containing a borate bond are then added. The mixture is reacted for 1-3 hours, and then 1,4-butanediol and trimethylolpropane are added. The reaction is continued for 100 minutes, the mixture is cooled to 40°C, and triethylamine is added for neutralization for 30 minutes. The mixture is cooled to 25°C, and finally filtered, washed, and dried to obtain a polysiloxane-polyurethane copolymer.
3. The environmentally friendly shoemaking offset printing material treating agent according to claim 2, characterized in that: The mass ratio of isophorone isocyanate, polyether 210, bis(4-hydroxyphenyl) disulfide, dihydroxy-terminated polysiloxane, and dibutyltin dilaurate is 10:22:(2-4):(2-4):(0.02-0.04):(1-3):(1-3):2:
2.
4. The environmentally friendly shoemaking offset printing material treating agent according to claim 2, characterized in that: The preparation method of the borate ester bond-containing chain extender is: 4-Hydroxyphenylboric acid was dissolved in tetrahydrofuran, and then glycerol and anhydrous magnesium sulfate were added. After mixing, the temperature was raised to 60° C., condensed and refluxed for 24 hours, and then cooled to 25° C., filtered, and vacuum distilled, washed, and dried to obtain a chain extender containing a borate ester bond.
5. The environmentally friendly shoemaking offset printing material treating agent according to claim 4, characterized in that: The usage ratio of 4-hydroxyphenylboric acid, tetrahydrofuran and glycerol is 13.8 g:50-60 mL:18.6 g.
6. The environmentally friendly shoemaking offset printing material treating agent according to claim 1, characterized in that: The preparation method of the PDA@ nano-silica is: Dopamine was dissolved in Tris buffer, nano-silica was added, and the mixture was stirred at room temperature for 7-10 hours. Finally, PDA@nano-silica was obtained by centrifugation, washing, and drying.
7. The environmentally friendly shoemaking offset printing material treating agent according to claim 6, characterized in that: The usage ratio of dopamine, Tris buffer and nano-silica is 2-4 g:50 mL:2 g.
8. The environmentally friendly shoemaking offset printing material treating agent according to claim 1, characterized in that: The defoamer is a nonionic polyurethane defoamer.
9. The environmentally friendly shoemaking offset printing material treating agent according to claim 1, characterized in that: The wetting agent is an organosilicon wetting agent.
10. A method for preparing an environmentally friendly treatment agent for offset printing materials in the shoe industry, for preparing the treatment agent for offset printing materials in the shoe industry according to any one of claims 1 to 9, characterized in that: The following steps are involved: Adding a polysiloxane-polyurethane copolymer to deionized water and stirring to obtain a polysiloxane-polyurethane copolymer solution; dispersing PDA@nano-silica in deionized water to obtain a PDA@nano-silica dispersion; then adding the polysiloxane-polyurethane copolymer solution to an aqueous polyurethane resin, stirring for 30-50 minutes, adding the PDA@nano-silica dispersion, stirring for 40-60 minutes, and then adding a defoamer, a wetting agent and an aqueous polyurethane thickener. After stirring and mixing, filtering and packaging are performed to obtain a shoe offset printing material treating agent.