Anti-yellowing lining cloth with hot melt coating and preparation method of anti-yellowing lining cloth

Abstract

The invention relates to the technical field of anti-yellowing, in particular to anti-yellowing lining cloth with a hot melt coating and a preparation method of the anti-yellowing lining cloth. Composite carbon dots, an anti-yellowing agent and a composite chitosan solution are adopted to prepare finishing liquid for finishing the lining cloth; the preparation method comprises the following steps: selecting furfural and urea as a carbon source and a nitrogen source, performing one-step hydrothermal synthesis to obtain a nitrogen-doped furfural-based carbon dot, and grafting an amino-terminated polyimidazolium salt antibacterial compound to obtain a composite carbon dot; wherein the amino-terminated polyimidazolium salt antibacterial compound is an amino-terminated halogen-free polyimidazolium salt antibacterial compound which is prepared by taking ethylenediamine, butyric acid, glyoxal and formaldehyde as raw materials based on amine-aldehyde polycondensation and has good biocompatibility; the preparation method comprises the following steps: by taking polybutylene adipate, toluene diisocynate and isophorone diisocyanate as main monomers, polypropylene oxide triol as a crosslinking monomer, 2, 2-dimethylolpropionic acid and 4, 4 '-diaminodiphenyl disulfide as chain extenders and composite carbon dots as an end-capping reagent, adding water and emulsifying to obtain the waterborne polyurethane hot melt adhesive.

Description

Technical Field

[0001] The invention relates to the technical field of anti-yellowing, in particular to an anti-yellowing lining cloth with a hot-melt coating and a preparation method thereof. Background Art

[0002] With the improvement of people's living standards, the demand for functional interlinings is growing, especially in the fields of clothing and footwear. Interlinings with hot-melt coatings are generally compounded with fabrics through hot pressing. Traditional interlinings with hot-melt coatings are prone to yellowing when exposed to ultraviolet rays, humidity and heat for a long time, affecting their appearance and service life. At the same time, their poor antibacterial properties also limit the application range of functional interlinings.

[0003] Currently, improving the anti-yellowing properties of interlinings relies heavily on finishing with organic UV absorbers, such as benzotriazole, or inorganic UV absorbers, such as metal oxides. Most organic UV absorbers on the market are fat-soluble compounds that are easily absorbed and penetrate the skin and enter the human body through the food chain. Studies have shown that some organic UV absorbers pose potential health risks. Commonly used inorganic UV absorbers, such as titanium dioxide and zinc oxide nanoparticles, have poor compatibility with textiles, resulting in insufficient durability and migration. Furthermore, conventional antimicrobial agents, such as silver-based and quaternary ammonium salt antimicrobials, suffer from poor washability and biotoxicity. Meanwhile, the introduction of hot-melt coatings into functional interlinings can improve their adhesion, but traditional solvent-based polyurethane hot-melt adhesives also pose environmental risks. Summary of the Invention

[0004] The object of the present invention is to provide an anti-yellowing lining cloth with a hot-melt coating and a preparation method thereof, so as to solve the problems in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A method for preparing an anti-yellowing lining cloth with a hot-melt coating comprises the following steps:

[0007] S1: mixing the composite carbon dots, anti-yellowing agent solution, and composite chitosan solution, and stirring with ultrasound to obtain an anti-yellowing and anti-bacterial finishing solution;

[0008] S2: using an anti-yellowing and anti-bacterial finishing liquid to perform a double-dipping and double-padding treatment on the interlining cloth, and pre-drying the cloth to obtain the finished interlining cloth;

[0009] S3: coating the surface of the finished interlining with a water-based polyurethane hot melt adhesive and drying the adhesive to obtain an anti-yellowing interlining with a hot melt coating.

[0010] Furthermore, the working conditions of the double dipping and double rolling treatment are: dipping time is 50s, and rolling rate is 82%.

[0011] Furthermore, the working conditions of the pre-baking are: temperature of 100° C. and time of 100 s.

[0012] Furthermore, the usage ratio of the composite carbon dots, the anti-yellowing agent solution, and the composite chitosan solution is 1 g: 0.2 g: (40-45) mL.

[0013] Furthermore, the composition of the composite chitosan solution is, by weight, 100 parts of deionized water, 2.1-2.3 parts of citric acid, 0.4-0.6 parts of chitosan, 0.3-0.5 parts of triethanolamine, 0.5-1 parts of sodium hypophosphite, and 0.1 parts of penetrant.

[0014] Furthermore, the mass ratio of polybutylene adipate, polypropylene oxide ether triol, toluene diisocyanate, isophorone diisocyanate, 2,2-dihydroxymethylpropionic acid, 4,4'-diaminodiphenyl disulfide, and composite carbon dots is 32:1:16:4:4:2:1.

[0015] Furthermore, the preparation of the water-based polyurethane hot melt adhesive includes the following steps:

[0016] Mix polybutylene adipate, polypropylene oxide ether triol, toluene diisocyanate, and isophorone diisocyanate, add dibutyltin dilaurate at 58-62°C, raise the temperature to 73-75°C and keep warm for 50-60 minutes, add 2,2-dihydroxymethylpropionic acid and keep warm for 1-2 hours, add 4,4'-diaminodiphenyl disulfide and keep warm for 1-2 hours, add composite carbon dots and acetone, keep warm for 1-2 hours, cool, add ethylenediamine, rotary evaporate, and emulsify with deionized water to obtain a water-based polyurethane hot melt adhesive.

[0017] Furthermore, the preparation of composite carbon dots includes the following steps:

[0018] 1) Furfural, urea, and deionized water were mixed and transferred to a reactor, heated to 198-200° C. and kept warm for 9-10 hours, cooled to 18-25° C., centrifuged, filtered through a 0.22 μm aqueous membrane, and dialyzed for 7 days to obtain nitrogen-doped furfural carbon dots;

[0019] 2) mixing ethylenediamine and deionized water, adding butyric acid, glyoxal, and formaldehyde in an ice bath at 0°C, and adding sodium hydroxide solution to adjust the pH to 6.9-7.1, heating the oil bath to 98-100°C and maintaining the temperature for 34-36 hours, transferring the mixture to a dialysis bag with a molecular weight cutoff of 1000 Da, dialyzing the mixture for 22-24 hours, and freeze-drying to obtain an amino-terminated polyimidazole salt antibacterial compound;

[0020] 3) Mixing the amino-terminated polyimidazole salt antibacterial compound and toluene, adding nitrogen-doped furfural carbon dots, heating in a water bath to 85-95° C., adding glacial acetic acid, keeping the temperature for 3-4 hours, cooling, standing, and filtering under reduced pressure to obtain composite carbon dots.

[0021] Furthermore, the mass ratio of the amino-terminated polyimidazole salt antibacterial compound and the nitrogen-doped furfural carbon dots is 1.2:3.2.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention provides an anti-yellowing lining cloth with a hot-melt coating and a preparation method thereof. Through process and component design, a green, environmentally friendly, antibacterial, and UV-resistant anti-yellowing lining cloth with a self-repairing hot-melt coating is prepared.

[0024] Composite carbon dots are used as UV absorbers, and environmentally friendly antioxidants are combined with composite chitosan solution as anti-yellowing agents to prepare a finishing liquid for finishing the lining cloth. In the composite chitosan solution, triethanolamine is selected as a pH buffer, chitosan is used as a bio-based antibacterial agent, citric acid and sodium hypophosphite are used as acidifiers and catalysts, and a penetrant is added. By controlling the ratio of each raw material, when the lining cloth is finished with the finishing liquid, the lining cloth, composite carbon dots, chitosan, and polyphenol environmentally friendly antioxidant form a complex cross-linked network, constructing a multi-layer protection system, effectively inhibiting the yellowing of the lining cloth under ultraviolet, humid and hot environments, and ensuring that the lining cloth maintains excellent antibacterial and anti-ultraviolet effects for a long time.

[0025] Carbon dots with low toxicity, good biocompatibility and environmental friendliness are selected as anti-ultraviolet agents, and furfural and urea are selected as carbon sources and nitrogen sources to synthesize nitrogen-doped furfural-based carbon dots by one-step hydrothermal synthesis. In order to improve the uniformity of dispersion of nitrogen-doped furfural-based carbon dots in the finishing liquid, the aldehyde groups on the nitrogen-doped furfural-based carbon dots are used to graft amino-terminated polyimidazole salt antibacterial compounds to obtain composite carbon dots containing Schiff base structure, thereby greatly improving the ultraviolet resistance and antibacterial properties of the carbon dots. The introduction of multiple active sites on its surface improves the bonding strength between the composite carbon dots and the lining cloth; among them, the amino-terminated polyimidazole salt antibacterial compound is prepared from ethylenediamine, butyric acid, glyoxal and formaldehyde based on amine-aldehyde condensation to obtain an amino-terminated halogen-free polyimidazole salt antibacterial compound with good biocompatibility. The ultraviolet absorption and antibacterial properties of the Schiff base structure are used to further synergistically improve the ultraviolet absorption and antibacterial properties of the composite carbon dots, achieving broad-spectrum antibacterial and anti-ultraviolet effects.

[0026] In order to solve the environmental pollution problem of traditional solvent-based polyurethane hot melt adhesive, the present invention adopts water-based polyurethane hot melt adhesive to replace traditional solvent-based hot melt adhesive, reduce VOC emissions, and meet green production requirements. Polybutylene adipate, toluene diisocyanate, and isophorone diisocyanate are used as main monomers, polypropylene oxide ether triol is used as a cross-linking monomer, 2,2-dihydroxymethylpropionic acid and 4,4'-diaminodiphenyl disulfide are used as chain extenders, and composite carbon dots are used as end-capping agents. Water is added and emulsified to obtain a water-based polyurethane hot melt adhesive. The addition of composite carbon dots not only enhances the antibacterial and UV resistance, but also the composite carbon dots cooperate with disulfide bonds to convert the absorbed ultraviolet light into heat energy for release, thereby reducing the impact of ultraviolet radiation on the polyurethane structure. At the same time, the Schiff base structure on the composite carbon dots and the disulfide bonds form a dynamic network, giving the coating excellent self-healing properties, thereby improving the durability of the coating's resistance to yellowing, achieving long-lasting antibacterial and UV resistance effects, and extending the service life of the lining cloth. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0029] The technical solutions of the present invention are further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely used to explain the present invention and are not intended to limit the present invention.

[0030] Example 1: A method for preparing an anti-yellowing lining cloth having a hot-melt coating, comprising the following steps:

[0031] S1: mixing the composite carbon dots, anti-yellowing agent solution, and composite chitosan solution, and stirring with ultrasound to obtain an anti-yellowing and anti-bacterial finishing solution;

[0032] The dosage ratio of composite carbon dots, anti-yellowing agent solution, and composite chitosan solution is 1 g: 0.2 g: 45 mL;

[0033] The composition of the composite chitosan solution is as follows, by mass: 100 parts of deionized water, 2.1 parts of citric acid, 0.4 parts of chitosan, 0.3 parts of triethanolamine, 0.5 parts of sodium hypophosphite, and 0.1 parts of penetrant;

[0034] The preparation of composite carbon dots includes the following steps:

[0035] 1) 1 mL of furfural, 60 mg of urea, and 10 mL of deionized water were mixed and transferred to a reactor. The mixture was heated to 198°C and kept for 10 h. The mixture was cooled to 18°C ​​and centrifuged. The mixture was filtered through a 0.22 μm aqueous membrane and dialyzed for 7 days to obtain nitrogen-doped furfural carbon dots.

[0036] 2) 1.4 g of ethylenediamine and 2 mL of deionized water were mixed, and 4 g of butyric acid, 3.3 g of glyoxal, and 1.7 g of formaldehyde were added in an ice bath at 0°C. Sodium hydroxide solution was added to adjust the pH to 6.9, and the oil bath was heated to 98°C for 36 h. The mixture was transferred to a dialysis bag with a molecular weight cutoff of 1000 Da and dialyzed for 22 h. The mixture was freeze-dried to obtain an amino-terminated polyimidazole salt antibacterial compound;

[0037] 3) 1.2 g of an amino-terminated polyimidazole salt antibacterial compound and 30 mL of toluene were mixed, 3.2 g of nitrogen-doped furfural carbon dots were added, and the mixture was heated to 85°C in a water bath. 0.3 mL of glacial acetic acid was added and the mixture was kept warm for 4 h. The mixture was cooled, allowed to stand, and filtered under reduced pressure to obtain composite carbon dots.

[0038] The preparation of the water-based polyurethane hot melt adhesive comprises the following steps:

[0039] 32 g of polybutylene adipate, 1 g of polypropylene oxide ether triol, 16 g of toluene diisocyanate, and 4 g of isophorone diisocyanate were mixed, 4 drops of dibutyltin dilaurate were added at 58°C, the temperature was raised to 73°C and kept warm for 60 min, 4 g of 2,2-dimethylolpropionic acid was added and kept warm for 1 h, 2 g of 4,4'-diaminodiphenyl disulfide was added and kept warm for 1 h, 1 g of composite carbon dots and 5 mL of acetone were added, the temperature was lowered to 35°C, 3 g of ethylenediamine was added, the mixture was rotary evaporated, and deionized water was added to emulsify to obtain a water-based polyurethane hot melt adhesive with a solid content of 40%;

[0040] S2: using an anti-yellowing and anti-bacterial finishing liquid to perform a double-dipping and double-padding treatment on the interlining cloth, and pre-drying the cloth to obtain the finished interlining cloth;

[0041] The working conditions of the double dip and double rolling treatment are: dipping time is 50s, rolling rate is 80%; the working conditions of the pre-baking are: temperature is 100℃, time is 100s;

[0042] S3: coating the surface of the finished interlining with a water-based polyurethane hot melt adhesive and drying the adhesive to obtain an anti-yellowing interlining with a hot melt coating.

[0043] Example 2: A method for preparing an anti-yellowing lining cloth having a hot-melt coating, comprising the following steps:

[0044] S1: mixing the composite carbon dots, anti-yellowing agent solution, and composite chitosan solution, and stirring with ultrasound to obtain an anti-yellowing and anti-bacterial finishing solution;

[0045] The dosage ratio of composite carbon dots, anti-yellowing agent solution, and composite chitosan solution is 1 g: 0.2 g: 43 mL;

[0046] The composition of the composite chitosan solution is as follows, by mass: 100 parts of deionized water, 2.2 parts of citric acid, 0.5 parts of chitosan, 0.4 parts of triethanolamine, 0.6 parts of sodium hypophosphite, and 0.1 parts of penetrant;

[0047] The preparation of composite carbon dots includes the following steps:

[0048] 1) 1 mL of furfural, 60 mg of urea, and 10 mL of deionized water were mixed and transferred to a reactor. The mixture was heated to 199°C and kept for 9.5 h. The mixture was cooled to 20°C and centrifuged. The mixture was filtered through a 0.22 μm aqueous membrane and dialyzed for 7 days to obtain nitrogen-doped furfural carbon dots.

[0049] 2) 1.4 g of ethylenediamine and 2 mL of deionized water were mixed, and 4 g of butyric acid, 3.3 g of glyoxal, and 1.7 g of formaldehyde were added in an ice bath at 0°C. Sodium hydroxide solution was added to adjust the pH to 7, and the oil bath was heated to 99°C for 35 h. The mixture was transferred to a dialysis bag with a molecular weight cutoff of 1000 Da and dialyzed for 23 h. The mixture was freeze-dried to obtain an amino-terminated polyimidazole salt antibacterial compound;

[0050] 3) 1.2 g of an amino-terminated polyimidazole salt antibacterial compound and 30 mL of toluene were mixed, 3.2 g of nitrogen-doped furfural carbon dots were added, and the mixture was heated to 90° C. in a water bath. 0.3 mL of glacial acetic acid was added and the mixture was kept warm for 3.5 h. The mixture was cooled, allowed to stand, and filtered under reduced pressure to obtain composite carbon dots.

[0051] The preparation of the water-based polyurethane hot melt adhesive comprises the following steps:

[0052] 32 g of polybutylene adipate, 1 g of polypropylene oxide ether triol, 16 g of toluene diisocyanate, and 4 g of isophorone diisocyanate were mixed, 4 drops of dibutyltin dilaurate were added at 60°C, the temperature was raised to 74°C and kept warm for 55 min, 4 g of 2,2-dimethylolpropionic acid was added and kept warm for 1.5 h, 2 g of 4,4'-diaminodiphenyl disulfide was added and kept warm for 1.5 h, 1 g of composite carbon dots and 5 mL of acetone were added, the temperature was kept warm for 1.5 h, the temperature was lowered to 35°C, 3 g of ethylenediamine was added, the mixture was rotary evaporated, and deionized water was added for emulsification to obtain a water-based polyurethane hot melt adhesive with a solid content of 40%;

[0053] S2: using an anti-yellowing and anti-bacterial finishing liquid to perform a double-dipping and double-padding treatment on the interlining cloth, and pre-drying the cloth to obtain the finished interlining cloth;

[0054] The working conditions of the double dip and double rolling treatment are: dipping time is 50s, rolling rate is 80%; the working conditions of the pre-baking are: temperature is 100℃, time is 100s;

[0055] S3: coating the surface of the finished interlining with a water-based polyurethane hot melt adhesive and drying the adhesive to obtain an anti-yellowing interlining with a hot melt coating.

[0056] Example 3: A method for preparing an anti-yellowing lining cloth having a hot-melt coating, comprising the following steps:

[0057] S1: mixing the composite carbon dots, anti-yellowing agent solution, and composite chitosan solution, and stirring with ultrasound to obtain an anti-yellowing and anti-bacterial finishing solution;

[0058] The dosage ratio of composite carbon dots, anti-yellowing agent solution, and composite chitosan solution is 1 g: 0.2 g: 40 mL;

[0059] The composition of the composite chitosan solution is as follows, by mass: 100 parts of deionized water, 2.3 parts of citric acid, 0.6 parts of chitosan, 0.5 parts of triethanolamine, 1 part of sodium hypophosphite, and 0.1 parts of penetrant;

[0060] The preparation of composite carbon dots includes the following steps:

[0061] 1) 1 mL of furfural, 60 mg of urea, and 10 mL of deionized water were mixed and transferred to a reactor. The mixture was heated to 200°C and kept for 9 h. The mixture was cooled to 25°C and centrifuged. The mixture was filtered through a 0.22 μm aqueous membrane and dialyzed for 7 days to obtain nitrogen-doped furfural carbon dots.

[0062] 2) 1.4 g of ethylenediamine and 2 mL of deionized water were mixed, and 4 g of butyric acid, 3.3 g of glyoxal, and 1.7 g of formaldehyde were added in an ice bath at 0°C. Sodium hydroxide solution was added to adjust the pH to 7.1, and the oil bath was heated to 100°C for 34 h. The mixture was transferred to a dialysis bag with a molecular weight cutoff of 1000 Da and dialyzed for 24 h. The mixture was freeze-dried to obtain an amino-terminated polyimidazole salt antibacterial compound;

[0063] 3) 1.2 g of an amino-terminated polyimidazole salt antibacterial compound and 30 mL of toluene were mixed, 3.2 g of nitrogen-doped furfural carbon dots were added, and the mixture was heated to 95°C in a water bath. 0.3 mL of glacial acetic acid was added and the mixture was kept warm for 3 h. The mixture was cooled, allowed to stand, and filtered under reduced pressure to obtain composite carbon dots.

[0064] The preparation of the water-based polyurethane hot melt adhesive comprises the following steps:

[0065] 32 g of polybutylene adipate, 1 g of polypropylene oxide ether triol, 16 g of toluene diisocyanate, and 4 g of isophorone diisocyanate were mixed, 4 drops of dibutyltin dilaurate were added at 62°C, the temperature was raised to 75°C and kept warm for 50 min, 4 g of 2,2-dimethylolpropionic acid was added and kept warm for 2 h, 2 g of 4,4'-diaminodiphenyl disulfide was added and kept warm for 2 h, 1 g of composite carbon dots and 5 mL of acetone were added, the temperature was lowered to 35°C, 3 g of ethylenediamine was added, the mixture was rotary evaporated, and deionized water was added to emulsify to obtain a water-based polyurethane hot melt adhesive with a solid content of 40%;

[0066] S2: using an anti-yellowing and anti-bacterial finishing liquid to perform a double-dipping and double-padding treatment on the interlining cloth, and pre-drying the cloth to obtain the finished interlining cloth;

[0067] The working conditions of the double dip and double rolling treatment are: dipping time is 50s, rolling rate is 80%; the working conditions of the pre-baking are: temperature is 100℃, time is 100s;

[0068] S3: coating the surface of the finished interlining with a water-based polyurethane hot melt adhesive and drying the adhesive to obtain an anti-yellowing interlining with a hot melt coating.

[0069] Comparative Example 1: Using Example 3 as the control group, nitrogen-doped furfural carbon dots were used to replace the composite carbon dots, and the other processes were normal;

[0070] A method for preparing an anti-yellowing lining cloth with a hot-melt coating comprises the following steps:

[0071] S1: mixing the composite carbon dots, anti-yellowing agent solution, and composite chitosan solution, and stirring with ultrasound to obtain an anti-yellowing and anti-bacterial finishing solution;

[0072] The dosage ratio of composite carbon dots, anti-yellowing agent solution, and composite chitosan solution is 1 g: 0.2 g: 40 mL;

[0073] The composition of the composite chitosan solution is as follows, by mass: 100 parts of deionized water, 2.3 parts of citric acid, 0.6 parts of chitosan, 0.5 parts of triethanolamine, 1 part of sodium hypophosphite, and 0.1 parts of penetrant;

[0074] The preparation of composite carbon dots includes the following steps:

[0075] 1) 1 mL of furfural, 60 mg of urea, and 10 mL of deionized water were mixed and transferred to a reactor. The mixture was heated to 200°C and kept for 9 h. The mixture was cooled to 25°C and centrifuged. The mixture was filtered through a 0.22 μm aqueous membrane and dialyzed for 7 days to obtain nitrogen-doped furfural carbon dots.

[0076] The preparation of the water-based polyurethane hot melt adhesive comprises the following steps:

[0077] 32 g of polybutylene adipate, 1 g of polypropylene oxide ether triol, 16 g of toluene diisocyanate, and 4 g of isophorone diisocyanate were mixed, 4 drops of dibutyltin dilaurate were added at 62°C, the temperature was raised to 75°C and kept warm for 50 min, 4 g of 2,2-dimethylolpropionic acid was added and kept warm for 2 h, 2 g of 4,4'-diaminodiphenyl disulfide was added and kept warm for 2 h, 1 g of composite carbon dots and 5 mL of acetone were added, the temperature was lowered to 35°C, 3 g of ethylenediamine was added, the mixture was rotary evaporated, and deionized water was added to emulsify to obtain a water-based polyurethane hot melt adhesive with a solid content of 40%;

[0078] S2: using an anti-yellowing and anti-bacterial finishing liquid to perform a double-dipping and double-padding treatment on the interlining cloth, and pre-drying the cloth to obtain the finished interlining cloth;

[0079] The working conditions of the double dip and double rolling treatment are: dipping time is 50s, rolling rate is 80%; the working conditions of the pre-baking are: temperature is 100℃, time is 100s;

[0080] S3: coating the surface of the finished interlining with a water-based polyurethane hot melt adhesive and drying the adhesive to obtain an anti-yellowing interlining with a hot melt coating.

[0081] Comparative Example 2: Using Example 3 as the control group, 4,4'-diaminodiphenyl disulfide was not added during the preparation of the water-based polyurethane hot melt adhesive, and the other steps were normal;

[0082] A method for preparing an anti-yellowing lining cloth with a hot-melt coating comprises the following steps:

[0083] S1: mixing the composite carbon dots, anti-yellowing agent solution, and composite chitosan solution, and stirring with ultrasound to obtain an anti-yellowing and anti-bacterial finishing solution;

[0084] The dosage ratio of composite carbon dots, anti-yellowing agent solution, and composite chitosan solution is 1 g: 0.2 g: 40 mL;

[0085] The composition of the composite chitosan solution is as follows, by mass: 100 parts of deionized water, 2.3 parts of citric acid, 0.6 parts of chitosan, 0.5 parts of triethanolamine, 1 part of sodium hypophosphite, and 0.1 parts of penetrant;

[0086] The preparation of composite carbon dots includes the following steps:

[0087] 1) 1 mL of furfural, 60 mg of urea, and 10 mL of deionized water were mixed and transferred to a reactor. The mixture was heated to 200°C and kept for 9 h. The mixture was cooled to 25°C and centrifuged. The mixture was filtered through a 0.22 μm aqueous membrane and dialyzed for 7 days to obtain nitrogen-doped furfural carbon dots.

[0088] 2) 1.4 g of ethylenediamine and 2 mL of deionized water were mixed, and 4 g of butyric acid, 3.3 g of glyoxal, and 1.7 g of formaldehyde were added in an ice bath at 0°C. Sodium hydroxide solution was added to adjust the pH to 7.1, and the oil bath was heated to 100°C for 34 h. The mixture was transferred to a dialysis bag with a molecular weight cutoff of 1000 Da and dialyzed for 24 h. The mixture was freeze-dried to obtain an amino-terminated polyimidazole salt antibacterial compound;

[0089] 3) 1.2 g of an amino-terminated polyimidazole salt antibacterial compound and 30 mL of toluene were mixed, 3.2 g of nitrogen-doped furfural carbon dots were added, and the mixture was heated to 95°C in a water bath. 0.3 mL of glacial acetic acid was added and the mixture was kept warm for 3 h. The mixture was cooled, allowed to stand, and filtered under reduced pressure to obtain composite carbon dots.

[0090] The preparation of the water-based polyurethane hot melt adhesive comprises the following steps:

[0091] 32 g of polybutylene adipate, 1 g of polypropylene oxide ether triol, 16 g of toluene diisocyanate, and 4 g of isophorone diisocyanate were mixed, 4 drops of dibutyltin dilaurate were added at 62°C, the temperature was raised to 75°C and kept warm for 50 min, 4 g of 2,2-dimethylolpropionic acid was added and kept warm for 2 h, 1 g of composite carbon dots and 5 mL of acetone were added, the temperature was kept warm for 2 h, the temperature was lowered to 35°C, 3 g of ethylenediamine was added, the mixture was rotary evaporated, and deionized water was added to emulsify to obtain a water-based polyurethane hot melt adhesive with a solid content of 40%;

[0092] S2: using an anti-yellowing and anti-bacterial finishing liquid to perform a double-dipping and double-padding treatment on the interlining cloth, and pre-drying the cloth to obtain the finished interlining cloth;

[0093] The working conditions of the double dip and double rolling treatment are: dipping time is 50s, rolling rate is 80%; the working conditions of the pre-baking are: temperature is 100℃, time is 100s;

[0094] S3: coating the surface of the finished interlining with a water-based polyurethane hot melt adhesive and drying the adhesive to obtain an anti-yellowing interlining with a hot melt coating.

[0095] In the examples and comparative examples, a 2 μm thick water-based polyurethane hot melt adhesive was coated on the surface of the lining cloth after finishing.

[0096] The anti-yellowing agent solution in the examples and comparative examples was prepared by compounding the anti-yellowing agent and ethanol in a mass ratio of 1:1.

[0097] Sources of raw materials used (for demonstration purposes only):

[0098] Anti-yellowing agent (environmentally friendly antioxidant DTBHQ) 007: Pascal Pharmaceutical Technology (Shanghai) Co., Ltd.; Penetrant SF: Linyi Guoli Chemical Co., Ltd.; Polypropylene oxide ether triol PPO (Mn 500): Sinopec Tianjin Branch; Interlining (PP, AB303): Zhejiang Runjiang New Materials Technology Co., Ltd.; Citric acid C434175, chitosan C299272, furfural F100546, urea U111897, ethylenediamine E112132, butyric acid B 431361, glyoxal G661982, formaldehyde F111939, polybutylene adipate B302960, toluene diisocyanate T135411, isophorone diisocyanate I109582, dibutyltin dilaurate D100274, 2,2-dihydroxymethylpropionic acid B104539, 4,4'-diaminodiphenyl disulfide A101817: Aladdin reagent; triethanolamine, sodium hypophosphite, toluene, ethanol, acetic acid, acetone, analytical grade, commercially available.

[0099] Performance test: The interlinings prepared in the examples and comparative examples were tested:

[0100] Antibacterial property: Staphylococcus aureus was used as the test bacteria, and the plate method was used to test the washability of the samples with reference to the "Color fastness to household and commercial washing: accelerated method". Each wash lasted 5 minutes, and the antibacterial rate was tested after 20 washes and drying.

[0101] Yellowing resistance level: The samples were tested for water wash resistance with reference to "Color fastness to household and commercial washing: accelerated method". Each wash lasted 5 minutes, and the test was conducted after 20 washes. The test was conducted with reference to GB / T1766-2008. The samples were cut into 50mm squares. The working conditions of the yellowing resistance test chamber were: temperature of 60℃, 300W UV lamp, light source distance of 25cm, and illumination time of 12h. The color difference of the samples was measured using a universal colorimeter, and the color difference value was calculated. 0 is the best, indicating no discoloration.

[0102] Self-healing property: scratch the surface of the sample coating with a depth of 1 μm, a length of 0.5 mm, and a width of 1 μm, keep it at 70 ° C for 24 hours, observe the scratch length with an electron microscope, and calculate the self-healing rate (L 初始划 Scratch length - L existing scratch length) / L initial scratch length × 100%; the results are shown in Table 1;

[0103] Table 1

[0104] Antibacterial activity (%) Yellowing resistance grade Self-healing rate (%) Example 1 99.8 Level 0 99.9 Example 2 99.9 Level 0 99.9 Example 3 99.9 Level 0 100 Comparative Example 1 91.1 Level 1 92.4 Comparative Example 2 98.4 Level 1 95.3

[0105] The present invention provides an anti-yellowing lining cloth with a hot-melt coating and a preparation method thereof. Through process and component design, a green, environmentally friendly, antibacterial, and UV-resistant anti-yellowing lining cloth with a self-repairing hot-melt coating is prepared.

[0106] Comparing Example 3 with Comparative Example 1, it can be seen that carbon dots that are easy to synthesize, have low toxicity, good biocompatibility, and are environmentally friendly are selected as anti-ultraviolet agents, and furfural and urea are selected as carbon sources and nitrogen sources to hydrothermally synthesize nitrogen-doped furfural-based carbon dots in a one-step process. In order to improve the uniformity of dispersion of the nitrogen-doped furfural-based carbon dots in the finishing liquid, the aldehyde groups on the nitrogen-doped furfural-based carbon dots are grafted onto the amino groups on the amino-terminated polyimidazole salt antibacterial compound to obtain composite carbon dots containing a Schiff base structure, thereby greatly improving the ultraviolet resistance and antibacterial properties of the carbon dots. The introduction of multiple active sites on its surface improves the bonding strength between the composite carbon dots and the lining cloth. The amino-terminated polyimidazole salt antibacterial compound is an amino-terminated halogen-free polyimidazole salt antibacterial compound with good biocompatibility prepared by amine-aldehyde polycondensation using ethylenediamine, butyric acid, glyoxal, and formaldehyde as raw materials. The ultraviolet absorption and antibacterial properties of the Schiff base structure further synergistically enhance the ultraviolet absorption and antibacterial properties of the composite carbon dots, achieving broad-spectrum antibacterial and anti-ultraviolet effects.

[0107] By comparing Example 3 with Comparative Example 2, it can be seen that in order to solve the problem of environmental pollution of traditional solvent-based polyurethane hot melt adhesives, the present invention adopts water-based polyurethane hot melt adhesive to replace traditional solvent-based hot melt adhesives, reduce VOC emissions, and meet green production requirements. Polybutylene adipate, toluene diisocyanate, and isophorone diisocyanate are used as main monomers, polypropylene oxide ether triol is used as a cross-linking monomer, 2,2-dimethylolpropionic acid and 4,4'-diaminodiphenyl disulfide are used as chain extenders, and composite carbon dots are used as end-capping agents. Water is added and emulsified to obtain a water-based polyurethane hot melt adhesive. The addition of composite carbon dots not only enhances the antibacterial and UV resistance, but also the composite carbon dots cooperate with disulfide bonds to convert the absorbed ultraviolet light into heat energy for release, thereby reducing the impact of ultraviolet radiation on the polyurethane structure. At the same time, the Schiff base structure on the composite carbon dots and the disulfide bonds form a dynamic network, which gives the coating excellent self-healing properties, thereby improving the durability of the coating's resistance to yellowing, achieving long-lasting antibacterial and UV resistance effects, and extending the service life of the lining cloth.

[0108] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structural transformations made using the present invention specification under the inventive concept of the present invention, or any direct / indirect application in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for preparing an anti-yellowing lining cloth with a hot-melt coating, characterized in that: The following steps are involved: S1: mixing the composite carbon dots, anti-yellowing agent solution, and composite chitosan solution, and stirring with ultrasound to obtain an anti-yellowing and anti-bacterial finishing solution; S2: using an anti-yellowing and anti-bacterial finishing liquid to perform a double-dipping and double-padding treatment on the interlining cloth, and pre-drying the cloth to obtain the finished interlining cloth; S3: coating the surface of the finished interlining with a water-based polyurethane hot melt adhesive and drying the adhesive to obtain an anti-yellowing interlining with a hot melt coating.

2. The method for preparing a yellowing-resistant lining cloth with a hot-melt coating according to claim 1, characterized in that: The working conditions of the double-dipping and double-rolling treatment are: dipping time is 50s, and rolling rate is 82%.

3. The method for preparing an anti-yellowing lining cloth with a hot-melt coating according to claim 1, characterized in that: The working conditions of pre-baking are: temperature 100℃, time 100s.

4. The method for preparing a yellowing-resistant lining cloth with a hot-melt coating according to claim 1, characterized in that: In the anti-yellowing and anti-bacterial finishing liquid, the dosage ratio of the composite carbon dots, the anti-yellowing agent solution, and the composite chitosan solution is 1 g: 0.2 g: (40-45) mL.

5. The method for preparing an anti-yellowing lining cloth with a hot-melt coating according to claim 1, characterized in that: The composition of the composite chitosan solution is as follows, by weight: 100 parts of deionized water, 2.1-2.3 parts of citric acid, 0.4-0.6 parts of chitosan, 0.3-0.5 parts of triethanolamine, 0.5-1 parts of sodium hypophosphite, and 0.1 parts of a penetrant.

6. The method for preparing an anti-yellowing lining cloth with a hot-melt coating according to claim 1, characterized in that: The preparation of the water-based polyurethane hot melt adhesive comprises the following steps: Mix polybutylene adipate, polypropylene oxide ether triol, toluene diisocyanate, and isophorone diisocyanate, add dibutyltin dilaurate at 58-62°C, raise the temperature to 73-75°C and keep warm for 50-60 minutes, add 2,2-dihydroxymethylpropionic acid and keep warm for 1-2 hours, add 4,4'-diaminodiphenyl disulfide and keep warm for 1-2 hours, add composite carbon dots and acetone, keep warm for 1-2 hours, cool, add ethylenediamine, rotary evaporate, and emulsify with deionized water to obtain a water-based polyurethane hot melt adhesive.

7. The method for preparing the anti-yellowing lining cloth with a hot-melt coating according to claim 6, characterized in that: The mass ratio of the polybutylene adipate, polypropylene oxide ether triol, toluene diisocyanate, isophorone diisocyanate, 2,2-dihydroxymethyl propionic acid, 4,4'-diaminodiphenyl disulfide, and composite carbon dots is 32:1:16:4:4:2:

1.

8. The method for preparing an anti-yellowing lining cloth with a hot-melt coating according to claim 1, characterized in that: The preparation of the composite carbon dots comprises the following steps: 1) Furfural, urea, and deionized water are mixed, transferred to a reactor, heated to 198-200° C. and kept warm for 9-10 hours, cooled to 18-25° C., centrifuged, filtered, and dialyzed to obtain nitrogen-doped furfural carbon dots; 2) mixing ethylenediamine and deionized water, adding butyric acid, glyoxal, and formaldehyde in an ice bath at 0°C, and adding sodium hydroxide solution to adjust the pH to 6.9-7.1, heating the oil bath to 98-100°C for 34-36 hours, dialyzing for 22-24 hours, and freeze-drying to obtain an amino-terminated polyimidazole salt antibacterial compound; 3) Under a nitrogen atmosphere, the amino-terminated polyimidazole salt antibacterial compound and toluene are mixed, nitrogen-doped furfural carbon dots are added, the mixture is heated to 85-95° C. in a water bath, glacial acetic acid is added, the mixture is kept warm for 3-4 hours, cooled, allowed to stand, and filtered under reduced pressure to obtain composite carbon dots.

9. The method for preparing the anti-yellowing lining cloth with a hot-melt coating according to claim 8, characterized in that: The mass ratio of amino-terminated polyimidazole salt antibacterial compound and nitrogen-doped furfural carbon dots is 1.2:3.

2. 10.An anti-yellowing lining cloth with a hot-melt coating, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 9.