Environment-friendly water-based nylon treating agent for shoemaking industry and preparation method of environment-friendly water-based nylon treating agent

Abstract

The invention discloses an environment-friendly water-based nylon treating agent for the shoe making industry and a preparation method thereof, and belongs to the technical field of treating agents. The invention relates to an environment-friendly water-based nylon treating agent for the shoe making industry. The environment-friendly water-based nylon treating agent comprises the following raw materials in parts by weight: 80-100 parts of water-based polyurethane resin; 30 to 50 parts of polyisocyanate; 10 to 30 parts of waterborne polyurethane gloss oil; 5 to 15 parts of hyperbranched polyester modified nano silicon dioxide; 1-4 parts of a water-based thickening agent; 1-4 parts of a water-based wetting agent; 1-3 parts of a water-based leveling agent; and 15 to 20 parts of deionized water. The hyperbranched polyester modified nano silicon dioxide is added into the raw materials of the water-based nylon treating agent, so that particle aggregation can be effectively prevented, the high temperature resistance and the mechanical strength of the nylon treating agent are improved, and a nylon material is not easy to peel after being treated in a high-temperature environment.

Description

Technical Field

[0001] The present invention relates to the technical field of treating agents, in particular to an environmentally friendly water-based nylon treating agent for the shoemaking industry and a preparation method thereof. Background Art

[0002] Nylon (Polyamide, PA), also known as polyamide fiber, nylon, and nylon, is a general term for thermoplastic resins containing repeating amide groups (-NHCO-) ​​in their molecular chains. Nylon is widely used in footwear, particularly in athletic shoes, hiking shoes, and casual shoes. Nylon's high strength, abrasion resistance, good elasticity, and lightweight properties make it an ideal choice for footwear. For example, nylon elastomers excel in shoe soles, providing excellent support and durability. Nylon is also used in shoe uppers, such as those of athletic and hiking shoes, to enhance durability and comfort.

[0003] Water-based polyurethane adhesives are common shoe adhesives. Both nylon and water-based polyurethane have high polarity, but their polarity matching is not perfect. Nylon has a strong surface polarity, but its surface energy is low, resulting in low bonding strength with polyurethane. Nylon materials that have not been surface-treated are difficult to achieve ideal bonding strength. In order to improve the adhesion of adhesives to nylon, the nylon surface must be pretreated. There is little research on water-based nylon treatment agents in the prior art, and the matching degree between nylon treatment agents and adhesives and substrates is not high, resulting in reduced bonding strength and peel strength of the treatment agents. Summary of the Invention

[0004] The present invention provides an environmentally friendly water-based nylon treating agent for the shoemaking industry and a preparation method thereof, which can solve the problem in the prior art that the nylon treating agent is not well matched with the adhesive and substrate, resulting in reduced bonding strength and peel strength of the treating agent.

[0005] The purpose of the present invention can be achieved through the following technical solutions: In a first aspect, the present invention provides an environmentally friendly water-based nylon treating agent for the shoemaking industry, comprising the following raw materials in parts by weight: 80-100 parts of waterborne polyurethane resin 30-50 parts of polyisocyanate 10-30 parts water-based polyurethane varnish 5-15 parts of hyperbranched polyester modified nanosilica 1-4 parts water-based thickener 1-4 parts of aqueous wetting agent 1-3 parts of water-based leveling agent 15-20 parts of deionized water.

[0006] Furthermore, the water-based thickener is SD-301; the water-based wetting agent is an organosilicon wetting agent; and the water-based leveling agent is one or more of polyacrylic acid copolymer and organosilicon compound.

[0007] Furthermore, the step of modifying the nano-silica with hyperbranched polyester is: S1: Disperse nano-silica in an ethanol aqueous solution, add a disulfide-containing aminosilane coupling agent, react for 4-6 hours, filter the product under reduced pressure, wash, and vacuum dry to obtain modified nano-silica; The dosage ratio of nano-silica, ethanol aqueous solution and disulfide bond-containing aminosilane coupling agent is 1.5g:10-20mL:0.5-0.7g; the volume ratio of anhydrous ethanol to deionized water in the ethanol aqueous solution is 9:1.

[0008] S2: Disperse the modified nano-silica in anhydrous xylene under nitrogen protection, add 3,5-dihydroxybenzoic acid in batches, add p-toluenesulfonic acid as a catalyst, stir and react at reflux temperature for 4-6 hours, filter, wash, and vacuum dry at 60°C for 12-24 hours to obtain hyperbranched polyester modified nano-silica.

[0009] The dosage ratio of modified nano-silica, anhydrous xylene and 3,5-dihydroxybenzoic acid is 6g:240mL:1.5-9.5g; the mass of p-toluenesulfonic acid is 0.3%-1% of the mass of 3,5-dihydroxybenzoic acid.

[0010] Nano-silica has high mechanical strength and heat resistance, which can compensate for the high-temperature intolerance of nylon treatment agents and the poor mechanical strength of the coating, making the treated nylon material difficult to peel. However, nano-silica has strong surface binding energy and is prone to agglomeration. Therefore, the present invention treats the nano-silica with a disulfide-containing aminosilane coupling agent, introducing -NH2 as a reaction nucleus on its surface. This then undergoes a polycondensation reaction with an AB2-type monomer, introducing a hyperbranched polyester on its surface. The hyperbranched polyester is chemically bonded to the silica surface, and its highly branched three-dimensional structure effectively prevents particle agglomeration, thereby effectively exerting its reinforcing effect.

[0011] Furthermore, in step S1, the preparation steps of the disulfide bond-containing aminosilane coupling agent are: Mix γ-chloropropyltriethoxysilane, cystamine, potassium carbonate, potassium iodide and anhydrous toluene, and purge with nitrogen three times in an ice bath under nitrogen protection. React at 80°C for 12-24 hours. After the reaction is completed, filter, rotary evaporate, and vacuum dry for 24 hours to obtain a disulfide bond-containing aminosilane coupling agent.

[0012] The usage ratio of γ-chloropropyltriethoxysilane, cystamine, potassium carbonate, potassium iodide and anhydrous toluene is 1.2 g: 0.9 g: 0.2 g: 0.08 g: 10-15 mL.

[0013] In a second aspect, the present invention provides a method for preparing an environmentally friendly water-based nylon treatment agent for the shoemaking industry, comprising the following steps: Hyperbranched polyester modified nano-silica is added to deionized water, stirred, and ultrasonicated for 10-15 minutes to form a suspension; water-based polyurethane resin and polyisocyanate are added to the suspension, stirred and mixed for 20-30 minutes, and then water-based polyurethane varnish, water-based wetting agent, and water-based leveling agent are added, stirred and mixed for 20-30 minutes, and then a water-based thickener is added and stirred. After reaching the required viscosity, the material is discharged to obtain a water-based nylon treating agent.

[0014] Furthermore, the viscosity reaches 2000-3000 mPa·s at 25°C.

[0015] Beneficial effects of the present invention: 1. The present invention adds hyperbranched polyester modified nano-silica to the raw materials of the water-based nylon treating agent, which can effectively prevent particle agglomeration, improve the high temperature resistance and mechanical strength of the nylon treating agent, and make the nylon material not easy to peel off after being treated in a high temperature environment.

[0016] 2. All components of the present invention are water-based or water-dispersible, which avoids the flammability and toxicity problems of traditional solvent-based treatment agents, facilitates storage and transportation, and improves environmental protection.

[0017] 3. The hyperbranched polyester-modified nanosilica of the present invention contains amide groups, ester groups, and a large number of hydroxyl groups. The amide groups share the same structure as nylon materials and can improve the adhesion of the treatment agent to nylon materials. Because of the hydroxyl groups, the hyperbranched polyester-modified nanosilica can form a three-dimensional crosslinked network with the waterborne polyurethane resin and polyisocyanate, enhancing the coating's cohesion and preventing delamination caused by self-fracture.

[0018] 4. Hyperbranched polyester-modified nanosilica also contains benzene ring structures and disulfide bonds. The benzene ring reduces water molecule penetration through hydrophobic interaction, improving the water resistance of the treatment agent. The rigid structure of the benzene ring restricts molecular chain movement and, together with the cross-linked network, inhibits structural damage at high temperatures, thereby improving heat resistance. The disulfide bond is a reversible covalent bond. The dynamic reversible network formed during the cross-linking process can adapt to the interfacial stress between the nylon and the coating through chain segment adjustment, reducing peeling caused by thermal expansion and contraction or mechanical forces, and especially improving adhesion in humid / high-temperature environments. 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] Preparation Example 1 The steps of modifying nano-silica with hyperbranched polyester are: S1: 1.5 g of nano-silica was dispersed in 20 mL of ethanol-water solution, where the volume ratio of anhydrous ethanol to deionized water was 9:1. 0.5 g of a disulfide-containing aminosilane coupling agent was added and the mixture was reacted for 4 h. The product was filtered under reduced pressure, washed, and dried in vacuo to obtain modified nano-silica. S2: 6 g of modified nano-silica was dispersed in 240 mL of anhydrous xylene under nitrogen protection, 1.5 g of 3,5-dihydroxybenzoic acid was added in batches, and p-toluenesulfonic acid as a catalyst was added, with the mass of p-toluenesulfonic acid being 0.3% of the mass of 3,5-dihydroxybenzoic acid. The mixture was stirred and reacted at reflux temperature for 4 h, filtered, washed, and vacuum dried at 60°C for 12 h to obtain hyperbranched polyester modified nano-silica.

[0021] The preparation steps of the disulfide bond-containing aminosilane coupling agent are as follows: 1.2 g of γ-chloropropyltriethoxysilane, 0.9 g of cystamine, 0.2 g of potassium carbonate, 0.08 g of potassium iodide and 10 mL of anhydrous toluene were mixed, and the mixture was purged with nitrogen three times under ice bath conditions, protected by nitrogen, and reacted at 80°C for 24 h. After the reaction was completed, the mixture was filtered, rotary evaporated, and vacuum dried for 24 h to obtain a disulfide bond-containing aminosilane coupling agent.

[0022] Preparation Example 2 The steps of modifying nano-silica with hyperbranched polyester are: S1: 1.5 g of nano-silica was dispersed in 20 mL of ethanol-water solution, where the volume ratio of anhydrous ethanol to deionized water was 9:1. 0.6 g of a disulfide-containing aminosilane coupling agent was added and the mixture was reacted for 5 h. The product was filtered under reduced pressure, washed, and dried in vacuo to obtain modified nano-silica. S2: 6 g of modified nano-silica was dispersed in 240 mL of anhydrous xylene under nitrogen protection, and 5.5 g of 3,5-dihydroxybenzoic acid was added in batches. A catalyst of p-toluenesulfonic acid was added, and the mass of p-toluenesulfonic acid was 0.6% of the mass of 3,5-dihydroxybenzoic acid. The mixture was stirred and reacted at reflux temperature for 4 h. The mixture was filtered, washed, and vacuum dried at 60°C for 12 h to obtain hyperbranched polyester modified nano-silica.

[0023] The preparation steps of the disulfide bond-containing aminosilane coupling agent are the same as those in Preparation Example 1.

[0024] Preparation Example 3 The steps of modifying nano-silica with hyperbranched polyester are: S1: 1.5 g of nano-silica was dispersed in 20 mL of ethanol-water solution, where the volume ratio of anhydrous ethanol to deionized water was 9:1. 0.7 g of a disulfide-containing aminosilane coupling agent was added and the mixture was reacted for 6 h. The product was filtered under reduced pressure, washed, and dried in vacuo to obtain modified nano-silica. S2: 6 g of modified nano-silica was dispersed in 240 mL of anhydrous xylene under nitrogen protection, and 9.5 g of 3,5-dihydroxybenzoic acid and p-toluenesulfonic acid as a catalyst were added in batches. The mass of p-toluenesulfonic acid was 1% of the mass of 3,5-dihydroxybenzoic acid. The mixture was stirred and reacted at reflux temperature for 6 h. The mixture was filtered, washed, and vacuum dried at 60°C for 24 h to obtain hyperbranched polyester modified nano-silica.

[0025] The preparation steps of the disulfide bond-containing aminosilane coupling agent are the same as those in Preparation Example 1.

[0026] Comparative Example 1 The only difference between this comparative example and Preparation Example 1 is that the disulfide bond is omitted. The specific steps are as follows: S1: 1.5 g of nano-silica was dispersed in 20 mL of ethanol-water solution, where the volume ratio of anhydrous ethanol to deionized water was 9:1. 0.5 g of KH550 was added and the reaction was carried out for 4 h. The product was filtered under reduced pressure, washed, and dried in vacuo to obtain modified nano-silica. S2: 6 g of modified nano-silica was dispersed in 240 mL of anhydrous xylene under nitrogen protection, 1.5 g of 3,5-dihydroxybenzoic acid was added in batches, and p-toluenesulfonic acid as a catalyst was added, with the mass of p-toluenesulfonic acid being 0.3% of the mass of 3,5-dihydroxybenzoic acid. The mixture was stirred and reacted at reflux temperature for 4 h, filtered, washed, and vacuum dried at 60°C for 12 h to obtain hyperbranched polyester modified nano-silica.

[0027] Comparative Example 2 Compared with Preparation Example 1, the only difference in this comparative example is that 3,5-dihydroxybenzoic acid is replaced by dimethylolpropionic acid. The specific steps are as follows: S1: 1.5 g of nano-silica was dispersed in 20 mL of ethanol-water solution, where the volume ratio of anhydrous ethanol to deionized water was 9:1. 0.5 g of a disulfide-containing aminosilane coupling agent was added and the mixture was reacted for 4 h. The product was filtered under reduced pressure, washed, and dried in vacuo to obtain modified nano-silica. S2: 6 g of modified nano-silica was dispersed in 240 mL of anhydrous xylene under nitrogen protection, 1.5 g of dimethylolpropionic acid was added in batches, and a catalyst of p-toluenesulfonic acid was added, the mass of p-toluenesulfonic acid being 0.3% of the dimethylolpropionic acid. The mixture was stirred at reflux temperature for 4 h, filtered, washed, and vacuum dried at 60°C for 12 h to obtain hyperbranched polyester-modified nano-silica.

[0028] Comparative Example 3 This comparative example is nano-silicon dioxide.

[0029] Example 1 An environmentally friendly water-based nylon treating agent for the shoemaking industry comprises the following raw materials in parts by weight: 80 parts of waterborne polyurethane resin 30 parts of polyisocyanate 10 parts water-based polyurethane varnish 5 parts of the hyperbranched polyester modified nano-silica obtained in Preparation Example 1 1 part of water-based thickener SD-301 1 part of water-based wetting agent BYK-154 1 part of water-based leveling agent Wet 270 15 parts of deionized water.

[0030] Its preparation method is: Hyperbranched polyester modified nano-silica is added to deionized water, stirred, and ultrasonicated for 10 minutes to form a suspension; water-based polyurethane resin and polyisocyanate are added to the suspension, stirred and mixed for 20 minutes, and then water-based polyurethane varnish, water-based wetting agent, and water-based leveling agent are added, stirred and mixed for 20 minutes, and then a water-based thickener is added and stirred. After reaching a viscosity of 3000 mPa·s at 25°C, the material is discharged to obtain a water-based nylon treating agent.

[0031] Example 2 An environmentally friendly water-based nylon treating agent for the shoemaking industry comprises the following raw materials in parts by weight: 90 parts of waterborne polyurethane resin 40 parts of polyisocyanate 30 parts water-based polyurethane varnish 10 parts of the hyperbranched polyester modified nano-silica obtained in Preparation Example 1 4 parts of water-based thickener SD-301 4 parts of water-based wetting agent BYK-154 3 parts of water-based leveling agent Wet 270 20 parts of deionized water.

[0032] Its preparation method is: Hyperbranched polyester modified nano-silica is added to deionized water, stirred, and ultrasonicated for 15 minutes to form a suspension; water-based polyurethane resin and polyisocyanate are added to the suspension, stirred and mixed for 30 minutes, and then water-based polyurethane varnish, water-based wetting agent, and water-based leveling agent are added, stirred and mixed for 30 minutes, and then a water-based thickener is added and stirred. After reaching a viscosity of 3000 mPa·s at 25°C, the material is discharged to obtain a water-based nylon treating agent.

[0033] Example 3 An environmentally friendly water-based nylon treating agent for the shoemaking industry comprises the following raw materials in parts by weight: 100 parts of waterborne polyurethane resin 50 parts of polyisocyanate 30 parts water-based polyurethane varnish 15 parts of the hyperbranched polyester modified nano-silica obtained in Preparation Example 1 4 parts of water-based thickener SD-301 4 parts of water-based wetting agent BYK-154 3 parts of water-based leveling agent Wet 270 20 parts of deionized water.

[0034] Its preparation method is: Hyperbranched polyester modified nano-silica is added to deionized water, stirred, and ultrasonicated for 15 minutes to form a suspension; water-based polyurethane resin and polyisocyanate are added to the suspension, stirred and mixed for 0 minutes, and then water-based polyurethane varnish, water-based wetting agent, and water-based leveling agent are added, stirred and mixed for 30 minutes, and then a water-based thickener is added and stirred. After reaching a viscosity of 3000 mPa·s at 25°C, the material is discharged to obtain a water-based nylon treating agent.

[0035] Example 4 The only difference between this embodiment and embodiment 1 is that the hyperbranched polyester-modified nano-silica is the product prepared in preparation example 2.

[0036] Example 5 The only difference between this embodiment and embodiment 1 is that the hyperbranched polyester-modified nano-silica is the product prepared in preparation example 3.

[0037] Comparative Example 1 The only difference between this comparative example and Example 1 is that the hyperbranched polyester-modified nano-silica is replaced by the product in Comparative Example 1.

[0038] Comparative Example 2 The only difference between this comparative example and Example 1 is that the hyperbranched polyester-modified nano-silica is replaced by the product in Control Example 2.

[0039] Comparative Example 3 The only difference between this comparative example and Example 1 is that the hyperbranched polyester-modified nano-silica is replaced by the product in Control Example 3.

[0040] The nylon substrate was treated with the nylon treating agents prepared in Examples 1-5 and Comparative Examples 1-3 and the water-based polyurethane adhesive. The finished substrate was tested for initial peel strength (1 minute) and later peel strength (3 days) in accordance with the provisions of "GB / T 19340-2014 Adhesives for Shoes and Bags". The sample was placed in a sealed environment at a temperature of 70°C and a humidity of 95% for 3 days. The peel strength test is shown in Table 1 below.

[0041] Table 1 As shown in Table 1, the initial peel strength, later peel strength, and peel strength after high-temperature, high-humidity treatment of the treatment agent prepared in the Example are all superior to those of the Comparative Example. Comparative Example 1, which omits the disulfide bond compared to Example 1, exhibits lower peel strength and peel strength after high-temperature, high-humidity treatment than Example 1. This demonstrates that disulfide bonds are reversible covalent bonds. The dynamic, reversible network formed during the crosslinking process can adapt to the interfacial stress between the nylon and coating through segmental adjustments, reducing peeling caused by thermal expansion and contraction or mechanical forces, and particularly improving adhesion in humid / high-temperature environments.

[0042] Compared with Example 1, Comparative Example 2 omits the benzene ring, and the peel strength and the peel strength after high temperature and high humidity treatment are both lower than those of Example 1, indicating that the benzene ring reduces the penetration of water molecules through hydrophobic action, thereby improving the water resistance of the treating agent. The rigid structure of the benzene ring limits the movement of the molecular chain, and together with the cross-linked network, inhibits structural damage at high temperature, thereby improving heat resistance.

[0043] Comparative Example 3 does not contain a hyperbranched structure, and the adhesion of the treating agent to nylon and the water-based polyurethane adhesive becomes poor, and the overall performance is reduced.

[0044] 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 water-based nylon treating agent for the shoemaking industry, characterized in that: It includes the following raw materials in parts by weight: 80-100 parts of waterborne polyurethane resin 30-50 parts of polyisocyanate 10-30 parts water-based polyurethane varnish 5-15 parts of hyperbranched polyester modified nanosilica 1-4 parts water-based thickener 1-4 parts of aqueous wetting agent 1-3 parts of water-based leveling agent 15-20 parts of deionized water.

2. The environmentally friendly water-based nylon treating agent for the shoemaking industry according to claim 1, characterized in that: The water-based thickener is SD-301; the water-based wetting agent is an organosilicon wetting agent; and the water-based leveling agent is one or more of a polyacrylic acid copolymer and an organosilicon compound.

3. The environmentally friendly water-based nylon treating agent for the shoemaking industry according to claim 1, characterized in that: The steps of modifying the nano-silica with hyperbranched polyester are as follows: S1: Disperse nano-silica in an ethanol aqueous solution, add a disulfide-containing aminosilane coupling agent, react for 4-6 hours, filter the product under reduced pressure, wash, and vacuum dry to obtain modified nano-silica; S2: Disperse the modified nano-silica in anhydrous xylene under nitrogen protection, add 3,5-dihydroxybenzoic acid in batches, add p-toluenesulfonic acid as a catalyst, stir and react at reflux temperature for 4-6 hours, filter, wash, and vacuum dry at 60°C for 12-24 hours to obtain hyperbranched polyester modified nano-silica.

4. The environmentally friendly water-based nylon treating agent for the shoemaking industry according to claim 3, characterized in that: In step S1, the usage ratio of nano-silica, ethanol aqueous solution, and disulfide bond-containing aminosilane coupling agent is 1.5 g: 10-20 mL: 0.5-0.7 g.

5. The environmentally friendly water-based nylon treating agent for the shoemaking industry according to claim 3, characterized in that: In step S1, the volume ratio of anhydrous ethanol to deionized water in the ethanol aqueous solution is 9:

1.

6. The environmentally friendly water-based nylon treating agent for the shoemaking industry according to claim 3, characterized in that: In step S2, the usage ratio of modified nano-silica, anhydrous xylene, and 3,5-dihydroxybenzoic acid is 6 g:240 mL:1.5-9.5 g; the mass of p-toluenesulfonic acid is 0.3%-1% of the mass of 3,5-dihydroxybenzoic acid.

7. The environmentally friendly water-based nylon treating agent for the shoemaking industry according to claim 3, characterized in that: In step S1, the preparation steps of the disulfide bond-containing aminosilane coupling agent are as follows: Mix γ-chloropropyltriethoxysilane, cystamine, potassium carbonate, potassium iodide and anhydrous toluene, and purge with nitrogen three times in an ice bath under nitrogen protection. React at 80°C for 12-24 hours. After the reaction is completed, filter, rotary evaporate, and vacuum dry for 24 hours to obtain a disulfide bond-containing aminosilane coupling agent.

8. The environmentally friendly water-based nylon treating agent for the shoemaking industry according to claim 7, characterized in that: The usage ratio of γ-chloropropyltriethoxysilane, cystamine, potassium carbonate, potassium iodide and anhydrous toluene is 1.2 g: 0.9 g: 0.2 g: 0.08 g: 10-15 mL.

9. A method for preparing an environmentally friendly water-based nylon treatment agent for the shoe industry, for preparing the environmentally friendly water-based nylon treatment agent according to any one of claims 1 to 8, characterized in that: The following steps are involved: Add the hyperbranched polyester modified nano-silica into deionized water, stir, and ultrasonicate for 10-15 minutes to form a suspension; Add water-based polyurethane resin and polyisocyanate to the suspension, stir and mix for 20-30 minutes, then add water-based polyurethane varnish, water-based wetting agent, and water-based leveling agent, stir and mix for 20-30 minutes, then add water-based thickener and stir. After reaching the required viscosity, discharge the material to obtain a water-based nylon treatment agent.

10. The method for preparing an environmentally friendly water-based nylon treating agent for the shoe industry according to claim 9, characterized in that: The viscosity reaches 2000-3000 mPa·s at 25°C.

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