A coating composition with light absorption and depth enhancement function

Abstract

The invention discloses a coating composition with a light absorption deepening function, and relates to the technical field of textile coating printing. The invention discloses a coating composition with a light absorption deepening function, including a cationic deepening agent; the cationic deepening agent accounts for 50-60% of the total weight of the coating composition; the preparation method of the cationic deepening agent comprises the following steps: after prepolymerizing PEG1000 and isophorone diisocyanate, using N-methyldiethanolamine as a hydrophilic chain extender to react, then using butanone oxime to protect the remaining isocyanate groups, and using amino-modified silica to cationize the components to obtain a reaction solution 2; finally, using the reaction solution 2 to cross-link with an acrylate resin to obtain a cationic deepening agent. The cationic deepening agent prepared in the present application is used as a deepening agent to finish the fabric, and has a good deepening effect on the fabric, and the treated fabric is soft and skin-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of textile coating printing, and in particular to a coating composition with a light absorption and depth enhancement function. Background Art

[0002] The depth of fabric dyeing is restricted by the fiber dyeing balance and dye fastness, and sometimes it is difficult to meet the requirements. For dark products whose dyeing depth does not meet the requirements or the amount of dye used is large, the darkening agent has a good practical value. According to the method of use, the darkening agent can be divided into two categories: the darkening agent used in the dyeing process and the darkening agent used after dyeing. The darkening principle of the former is actually to modify the fiber surface, thereby changing or improving the fiber surface properties, improving the fiber's affinity for dyes and coatings, and allowing the coloring material to be better absorbed and fixed; in addition, the dyeing performance can also be improved by changing the solubility of the dye in the solution or slightly changing the dye structure. The darkening principle of the latter is to cover a layer of low refractive index film on the surface of the fabric to change the fiber's reflection and refraction of light, so as to obtain a better apparent dark effect. The more commonly used film-forming substances are organic fluorine, organic silicon and acrylic resin; organic fluorine resin has a low refractive index (below 1.4) and a good dark effect, but the price is high; organic silicon resin has good softness but poor darkening effect; polyacrylate resin has a good darkening effect, but it is easy to make the fabric feel hard, affecting the use of the fabric. Summary of the invention

[0003] The purpose of the present invention is to provide a coating composition with light absorption enhancement function to solve the following technical problems:

[0004] The film-forming substance silicone resin added to the existing darkening agent has good softness but poor darkening effect; polyacrylate resin has good darkening effect, but it is easy to make the fabric feel hard, affecting the use of the fabric.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A coating composition with light absorption and depth enhancement function, the coating composition comprises a cationic depth enhancer; the cationic depth enhancer accounts for 50-60% of the total weight of the coating composition;

[0007] The preparation method of the cationic darkening agent comprises the following steps:

[0008] S1: Add polyethylene glycol, isophorone diisocyanate and N-methylpyrrolidone into reactor A, control the temperature at 60-70°C, and keep the temperature for reaction for 1-3h; add N-methyldiethanolamine, control the temperature at 60-70°C, and keep the temperature for reaction for 1-3h; continue to add butanone oxime, control the temperature at 40-50°C, and keep the temperature for reaction for 3-6h to obtain reaction solution 1;

[0009] S2: Add amino-modified silica to reactor A, control the temperature at 60-70°C, and keep the temperature for reaction for 1-3 hours; control the temperature at 50-60°C, add glacial acetic acid, keep the temperature for reaction for 0.5-1 hour, and add deionized water to obtain reaction solution 2;

[0010] S3: Add azobisisobutylamidine hydrochloride component 1, methyl methacrylate, isobutyl methacrylate, propyl methacrylate, deionized water and emulsifier into reactor B and disperse them evenly, add dioxane, control the temperature at 80-90°C, keep the temperature for reaction for 1-3h, add azobisisobutylamidine hydrochloride component 2, continue to keep the temperature for reaction for 2-4h, control the temperature at 40-50°C, add glacial acetic acid for neutralization, and obtain acrylate resin;

[0011] S4: Add reaction solution 2 and acrylic resin into reaction kettle C, control the temperature at 50-60°C, and keep the temperature for 3-6 hours to obtain a cationic darkening agent.

[0012] As a further solution of the present invention: the coating composition also includes: a binder, a thickener and water; the binder accounts for 20-30% of the total weight of the coating composition; the thickener accounts for 3-5% of the total weight of the coating composition; the balance is water, and the sum of the weight percentages of each component is 100%.

[0013] As a further embodiment of the present invention, the addition ratio of polyethylene glycol, isophorone diisocyanate, N-methylpyrrolidone, N-methyldiethanolamine, amino-modified dioxide, and glacial acetic acid in the materials of S1 and S2 is 10g: 5-8g: 100-200mL: 2-3.5g: 1.5-2g: 10-30g: 0.5-1g.

[0014] As a further scheme of the present invention: the emulsifier in S3 is obtained by mixing AEO-9 and OP-10 in a ratio of 1:1-2; the mass ratios of azobisisobutylamidine hydrochloride component one, methyl methacrylate, isobutyl methacrylate, propyl methacrylate, deionized water, emulsifier, dioxane, and azobisisobutylamidine hydrochloride component two are 0.04-0.1g: 10-25g: 1-2g: 5-8g: 150-250g: 1-1.5g: 2g: 0.04-0.1g.

[0015] As a further solution of the present invention: the mass ratio of the reaction solution 2 to the acrylate resin in S4 is 1:0.5-1.5.

[0016] As a further scheme of the present invention: the preparation method of the amino-modified silica comprises the following steps: adding anhydrous ethanol, ethyl orthosilicate, and γ-aminopropyltriethoxysilane into a reaction bottle and dispersing them evenly, controlling the temperature at 50-60°C, adding an ammonia solution, keeping the temperature for reaction for 6-9 hours, centrifuging, washing, and drying to obtain the amino-modified silica.

[0017] As a further scheme of the present invention: the ammonia solution is obtained by mixing deionized water, 25-30wt% ammonia water and anhydrous ethanol in a volume ratio of 1:0.8-1.2:3; the volume ratio of anhydrous ethanol, tetraethyl orthosilicate, γ-aminopropyltriethoxysilane and ammonia solution is 100-150mL:10mL:0.4-2.2mL:50-75mL.

[0018] As a further embodiment of the present invention: the binder is a cationic binder.

[0019] As a further embodiment of the present invention: the thickener is a non-ionic thickener.

[0020] As a further solution of the present invention: a method for preparing a coating composition having a light absorption enhancement function comprises the following steps:

[0021] A1: Add the binder, cationic darkening agent and water into a dispersion tank, stir at 400-500 rpm for 10 minutes to obtain a premix;

[0022] A2: Add a thickener and stir at 600-800 rpm for 20 min to obtain a coating composition.

[0023] As a further embodiment of the present invention: use of any of the above coating compositions in fabric darkening finishing.

[0024] As a further solution of the present invention: the fabric comprises natural fiber fabric, synthetic fiber fabric and natural fiber and synthetic fiber blended fabric.

[0025] As a further embodiment of the present invention, the natural fibers include one or more of plant fibers, animal fibers and mineral fibers blended in any ratio.

[0026] As a further solution of the present invention: the synthetic fiber includes one or more of polyester fiber, nylon fiber, acrylic fiber, chloroprene fiber, vinylon fiber, spandex fiber, and polyolefin stretch yarn, which are blended in any ratio.

[0027] As a further solution of the present invention, the coating composition having the function of light absorption and darkening is used to darken the fabric, which comprises the following steps:

[0028] B1: Use any of the above-mentioned coating compositions with light absorption and deepening function as deepening paste, and print with 100% deepening paste (mesh: 800-1000 mesh);

[0029] B2: Dry at 100-120°C for 5-10 minutes, and bake at 150-160°C for 2-3 minutes to obtain a fabric with light absorption enhancement effect.

[0030] Beneficial effects of the present invention:

[0031] The present application firstly prepolymerizes polyethylene glycol and isophorone diisocyanate to obtain a molecular chain with an isocyanate group as the terminal group, and uses N-methyldiethanolamine as a hydrophilic chain extender for reaction; and uses butanone oxime to protect the remaining isocyanate group of the above product to obtain a reaction solution 1; then uses amino-modified silica to react with the above product to obtain a cationic group on this basis. The present application combines silicone with polyurethane to prepare a silica-crosslinked polyurethane resin substance, which not only has a darkening effect, but also can improve the water washability of the darkening effect; the present application obtains an acrylate resin by reacting an initiator, a monomer, and an emulsifier; finally, the silica-crosslinked polyurethane resin substance is used to graft the acrylate resin to obtain a cation-modified polyurethane cross-linked acrylate resin as a cationic darkening agent.

[0032] The coating composition prepared in the present application can be adsorbed on the surface of the fabric in large quantities, forming a deposit on the fiber surface. The silicon dioxide in the darkening agent forms a rough structure on the fiber surface, which helps to give the fabric a good darkening effect. The positively charged cationic darkening agent is easily adsorbed on the negatively charged surface of the fabric fiber and can produce good softness. The silicone-containing cationic darkening agent can chemically bond with the fabric and adhere to the surface of the fabric to have a wash-resistant effect. The darkening slurry is used to form a dense, uneven film on the surface of the fabric in the printed area, thereby enhancing the absorption and reflection of light on the fiber surface, reducing reflected light, and making the fabric look darker. This effect is because the darkening slurry can change the degree of absorption, reflection and scattering of light by the fiber, thereby obtaining a better apparent dark effect, thereby enhancing the color depth and gloss of the fabric.

[0033] The present application utilizes the darkening agent to treat dyed fabrics, and the darkening effect is very obvious. The darkening agent prepared in the present application and the fabric attract each other, which increases the thickness of the film of the silicone emulsion on the fabric surface, thereby reducing the refractive index of the treated fabric and obtaining a better surface darkening effect. The darkening agent forms a film on the fiber surface, and has a regular directional arrangement. The film energy is low, and the orderly arranged molecules enable the residual valence bonds on the fiber surface to be better saturated; at the same time, the darkening agent has a softening and smoothing effect, improves the feel of the fabric after treatment, and increases the darkening effect of the fabric. The present application forms a uniform thin film of low-refractive-index resin on the surface of the dyed fabric, which correspondingly reduces the refractive index of the fabric and darkens the apparent color of the fabric. DETAILED DESCRIPTION

[0034] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0035] Embodiment 1 The preparation method of the cationic darkening agent comprises the following steps:

[0036] S1: 10 mL of deionized water, 8 mL of 25 wt% ammonia water, and 30 mL of anhydrous ethanol were mixed to obtain an ammonia solution; 100 mL of anhydrous ethanol, 10 mL of ethyl orthosilicate, and 2 mL of γ-aminopropyltriethoxysilane were added to a reaction bottle and dispersed evenly, the temperature was controlled at 50°C, 50 mL of an ammonia solution was added, the reaction was kept warm for 6 hours, centrifuged, washed, and dried to obtain amino-modified silica;

[0037] S2: Add 10 g PEG1000, 5 g isophorone diisocyanate, and 100 mL N-methylpyrrolidone into reactor A, control the temperature at 60°C, and keep the temperature for reaction for 1 hour; add 2 g N-methyldiethanolamine, control the temperature at 60°C, and keep the temperature for reaction for 1 hour; continue to add 3.5 g butanone oxime, control the temperature at 40°C, and keep the temperature for reaction for 3 hours to obtain reaction solution 1;

[0038] S3: Add 30g of amino-modified silica to reactor A, control the temperature at 60°C, and keep the temperature for reaction for 1h; control the temperature at 50°C, add 0.5g of glacial acetic acid, keep the temperature for reaction for 0.5h, and add deionized water to obtain reaction solution 2;

[0039] S4: 0.04 g of azobisisobutylamidine hydrochloride, 10 g of methyl methacrylate, 1 g of isobutyl methacrylate, 5 g of propyl methacrylate, 150 g of deionized water, 0.5 g of AEO-9 and 1 g of OP-10 were added to reactor B and dispersed evenly, 2 g of dioxane was added, the temperature was controlled at 80°C, and the reaction was kept warm for 1 h, 0.04 g of azobisisobutylamidine hydrochloride was added, the reaction was kept warm for 2 h, the temperature was controlled at 40°C, and glacial acetic acid was added for neutralization to obtain an acrylate resin;

[0040] S5: Add 100 g of reaction solution 2 and 150 g of acrylic resin into reactor C, control the temperature to 50-60° C., and keep the temperature to react for 3 hours to obtain a cationic darkening agent.

[0041] Embodiment 2 The preparation method of cationic darkening agent comprises the following steps:

[0042] S1: 10 mL of deionized water, 8 mL of 25 wt% ammonia water, and 30 mL of anhydrous ethanol were mixed to obtain an ammonia solution; 100 mL of anhydrous ethanol, 10 mL of ethyl orthosilicate, and 2 mL of γ-aminopropyltriethoxysilane were added to a reaction bottle and dispersed evenly, the temperature was controlled at 50°C, 50 mL of an ammonia solution was added, the reaction was kept warm for 6 hours, centrifuged, washed, and dried to obtain amino-modified silica;

[0043] S2: Add 10 g PEG1000, 6 g isophorone diisocyanate, and 100 mL N-methylpyrrolidone into reactor A, control the temperature at 65°C, and keep the temperature for 2 h; add 2 g N-methyldiethanolamine, control the temperature at 65°C, and keep the temperature for 2 h; continue to add 3.5 g butanone oxime, control the temperature at 45°C, and keep the temperature for 4 h to obtain reaction solution 1;

[0044] S3: Add 30g of amino-modified silica to reactor A, control the temperature to 65°C, and keep the temperature for reaction for 2h; control the temperature to 55°C, add 0.5g of glacial acetic acid, keep the temperature for reaction for 0.5h, and add deionized water to obtain reaction solution 2;

[0045] S4: 0.04 g of azobisisobutylamidine hydrochloride, 20 g of methyl methacrylate, 1 g of isobutyl methacrylate, 6 g of propyl methacrylate, 150 g of deionized water, 0.5 g of AEO-9 and 1 g of OP-10 were added to reactor B and dispersed evenly, 2 g of dioxane was added, the temperature was controlled at 85°C, and the reaction was kept warm for 2 h, 0.04 g of azobisisobutylamidine hydrochloride was added, the reaction was continued for 3 h, the temperature was controlled at 45°C, and glacial acetic acid was added for neutralization to obtain an acrylate resin;

[0046] S5: Add 100 g of reaction solution 2 and 150 g of acrylic resin into reactor C, control the temperature to 55° C., and keep the temperature to react for 4 hours to obtain a cationic darkening agent.

[0047] The preparation method of the cationic darkening agent of embodiment 3 comprises the following steps:

[0048] S1: 10 mL of deionized water, 8 mL of 25 wt% ammonia water, and 30 mL of anhydrous ethanol were mixed to obtain an ammonia solution; 100 mL of anhydrous ethanol, 10 mL of ethyl orthosilicate, and 2 mL of γ-aminopropyltriethoxysilane were added to a reaction bottle and dispersed evenly, the temperature was controlled at 50°C, 50 mL of an ammonia solution was added, the reaction was kept warm for 6 hours, centrifuged, washed, and dried to obtain amino-modified silica;

[0049] S2: Add 10 g PEG1000, 8 g isophorone diisocyanate, and 100 mL N-methylpyrrolidone into reactor A, control the temperature at 70°C, and keep the temperature for 3 h; add 2 g N-methyldiethanolamine, control the temperature at 70°C, and keep the temperature for 3 h; continue to add 3.5 g butanone oxime, control the temperature at 50°C, and keep the temperature for 6 h to obtain reaction solution 1;

[0050] S3: Add 30g of amino-modified silica to reactor A, control the temperature to 70°C, and keep the temperature for reaction for 3h; control the temperature to 60°C, add 1g of glacial acetic acid, keep the temperature for reaction for 1h, and add deionized water to obtain reaction solution 2;

[0051] S4: 0.04 g of azobisisobutylamidine hydrochloride, 25 g of methyl methacrylate, 2 g of isobutyl methacrylate, 8 g of propyl methacrylate, 150 g of deionized water, 0.5 g of AEO-9 and 1 g of OP-10 were added to reactor B and dispersed evenly, 2 g of dioxane was added, the temperature was controlled at 90°C, and the reaction was kept warm for 3 h, 0.04 g of azobisisobutylamidine hydrochloride was added, the reaction was continued at a temperature of 50°C, and glacial acetic acid was added for neutralization to obtain an acrylate resin;

[0052] S5: Add 100 g of reaction solution 2 and 150 g of acrylic resin into reactor C, control the temperature to 60° C., and keep the temperature to react for 6 hours to obtain a cationic darkening agent.

[0053] Embodiment 4 A method for preparing a coating composition having a light absorption enhancement function comprises the following steps:

[0054] A1: 20 g of adhesive (EM-500CONC produced by Foshan Yimei Kete Chemical Co., Ltd.), 50 g of the cationic darkening agent prepared in Example 1, and 25 mL of water were added to a dispersion tank and stirred at 400 rpm for 10 min to obtain a premix;

[0055] A2: Add 5 g of a thickener (a water-soluble nonionic polyurethane thickener of model VISCODISTM 1588 produced by ARCHROMA), stir at 600 rpm for 20 min to obtain a coating composition.

[0056] Embodiment 5 The preparation method of the coating composition having the function of enhancing light absorption depth comprises the following steps:

[0057] A1: 20 g of adhesive (EM-500CONC produced by Foshan Yimei Kete Chemical Co., Ltd.), 50 g of the cationic darkening agent prepared in Example 2, and 25 mL of water were added to a dispersion tank, and stirred at 400 rpm for 10 min to obtain a premix;

[0058] A2: Add 5 g of a thickener (a water-soluble nonionic polyurethane thickener of model VISCODISTM 1588 produced by ARCHROMA), stir at 600 rpm for 20 min to obtain a coating composition.

[0059] Embodiment 6 The method for preparing a coating composition having a light absorption enhancement function comprises the following steps:

[0060] A1: 20 g of adhesive (EM-500CONC produced by Foshan Yimei Kete Chemical Co., Ltd.), 50 g of the cationic darkening agent prepared in Example 3, and 25 mL of water were added to a dispersion tank, and stirred at 400 rpm for 10 min to obtain a premix;

[0061] A2: Add 5 g of a thickener (a water-soluble nonionic polyurethane thickener of model VISCODISTM 1588 produced by ARCHROMA), stir at 600 rpm for 20 min to obtain a coating composition.

[0062] Embodiment 7 The coating composition having the function of light absorption and darkening is used to darken fabrics, comprising the following steps:

[0063] B1: Using the coating composition with light absorption and deepening function prepared in Example 4 as a deepening paste, a black polyester fabric (152cm 50D / 48F 150 strands / 10cm×110 strands / 10cm) was treated, and 100% deepening paste printing (mesh: 800 mesh);

[0064] B2: Dry at 100°C for 10 minutes and bake at 150°C for 3 minutes to obtain a fabric with enhanced light absorption effect.

[0065] Embodiment 8 The coating composition with light absorption and darkening function is used to darken fabrics, comprising the following steps:

[0066] B1: Using the coating composition with light absorption and deepening function prepared in Example 5 as a deepening paste, a black polyester fabric (152cm 50D / 48F 150 strands / 10cm×110 strands / 10cm) was treated, and 100% deepening paste was used for printing (mesh: 800 mesh);

[0067] B2: Dry at 100°C for 10 minutes and bake at 150°C for 3 minutes to obtain a fabric with enhanced light absorption effect.

[0068] Example 9 A coating composition having a light absorption and darkening function is used to darken fabrics, comprising the following steps:

[0069] B1: Using the coating composition with light absorption and deepening function prepared in Example 6 as a deepening paste, a black polyester fabric (152cm 50D / 48F 150 strands / 10cm×110 strands / 10cm) was treated, and 100% deepening paste printing (mesh: 800 mesh);

[0070] B2: Dry at 100°C for 10 minutes and bake at 150°C for 3 minutes to obtain a fabric with enhanced light absorption effect.

[0071] The preparation method of the darkening agent of comparative example 1 comprises the following steps:

[0072] S1: 10 mL of deionized water, 8 mL of 25 wt% ammonia water, and 30 mL of anhydrous ethanol were mixed to obtain an ammonia solution; 100 mL of anhydrous ethanol, 10 mL of ethyl orthosilicate, and 2 mL of γ-aminopropyltriethoxysilane were added to a reaction bottle and dispersed evenly, the temperature was controlled at 50°C, 50 mL of an ammonia solution was added, the reaction was kept warm for 6 hours, centrifuged, washed, and dried to obtain amino-modified silica;

[0073] S2: Add 10 g PEG1000, 5 g isophorone diisocyanate, and 100 mL N-methylpyrrolidone into reactor A, control the temperature at 60°C, and keep the temperature for reaction for 1 hour; add 2 g N-methyldiethanolamine, control the temperature at 60°C, and keep the temperature for reaction for 1 hour; continue to add 3.5 g butanone oxime, control the temperature at 40°C, and keep the temperature for reaction for 3 hours to obtain reaction solution 1;

[0074] S3: adding 30 g of amino-modified silica into the reaction kettle A to obtain reaction solution 2;

[0075] S4: 0.04 g of azobisisobutylamidine hydrochloride, 10 g of methyl methacrylate, 1 g of isobutyl methacrylate, 5 g of propyl methacrylate, 150 g of deionized water, 0.5 g of AEO-9 and 1 g of OP-10 were added to reactor B and dispersed evenly, 2 g of dioxane was added, the temperature was controlled at 80°C, and the reaction was kept warm for 1 h, 0.04 g of azobisisobutylamidine hydrochloride was added, the reaction was kept warm for 2 h, the temperature was controlled at 40°C, and glacial acetic acid was added for neutralization to obtain an acrylate resin;

[0076] S5: Add 100 g of reaction solution 2 and 150 g of acrylic resin into reactor C, control the temperature to 50-60° C., and keep the temperature to react for 3-6 hours to obtain a darkening agent.

[0077] The preparation method of the darkening agent of comparative example 2 comprises the following steps:

[0078] S1: 10 mL of deionized water, 8 mL of 25 wt% ammonia water, and 30 mL of anhydrous ethanol were mixed to obtain an ammonia solution; 100 mL of anhydrous ethanol, 10 mL of ethyl orthosilicate, and 2 mL of γ-aminopropyltriethoxysilane were added to a reaction bottle and dispersed evenly, the temperature was controlled at 50°C, 50 mL of an ammonia solution was added, the reaction was kept warm for 6 hours, centrifuged, washed, and dried to obtain amino-modified silica;

[0079] S2: Add 10g PEG1000, 5g isophorone diisocyanate, and 100mL N-methylpyrrolidone into reactor A, control the temperature at 60°C, and keep the temperature for reaction for 1h; add 2g N-methyldiethanolamine, control the temperature at 60°C, and keep the temperature for reaction for 1h; add 30g amino-modified silica into reactor A, control the temperature at 60°C, and keep the temperature for reaction for 1h; control the temperature at 50°C, add 0.5g glacial acetic acid, keep the temperature for reaction for 0.5h, and add deionized water to obtain reaction solution 2;

[0080] S3: 0.04 g of azobisisobutylamidine hydrochloride, 10 g of methyl methacrylate, 1 g of isobutyl methacrylate, 5 g of propyl methacrylate, 150 g of deionized water, 0.5 g of AEO-9 and 1 g of OP-10 were added to reactor B and dispersed evenly, 2 g of dioxane was added, the temperature was controlled at 80°C, the reaction was kept warm for 1 h, 0.04 g of azobisisobutylamidine hydrochloride was added, the reaction was kept warm for 2 h, the temperature was controlled at 40°C, glacial acetic acid was added for neutralization, and acrylate resin was obtained;

[0081] S4: Add 100 g of reaction solution 2 and 150 g of acrylic resin into reactor C, control the temperature to 50-60° C., and keep the temperature to react for 3-6 hours to obtain a darkening agent.

[0082] The preparation method of the darkening agent of comparative example 3 comprises the following steps:

[0083] S1: Add 10g PEG1000, 5g isophorone diisocyanate and 100mL N-methylpyrrolidone into reactor A, control the temperature at 60°C, and keep the temperature for reaction for 1h; add 2g N-methyldiethanolamine, control the temperature at 60°C, and keep the temperature for reaction for 1h; continue to add 3.5g butanone oxime, control the temperature at 40°C, and keep the temperature for reaction for 3h to obtain reaction solution 1;

[0084] S2: Add 10 g of γ-aminopropyltriethoxysilane to reactor A, control the temperature to 60°C, and keep the temperature for reaction for 1 hour; control the temperature to 50°C, add 0.5 g of glacial acetic acid, keep the temperature for reaction for 0.5 hour, and add deionized water to obtain reaction solution 2;

[0085] S3: 0.04 g of azobisisobutylamidine hydrochloride, 10 g of methyl methacrylate, 1 g of isobutyl methacrylate, 5 g of propyl methacrylate, 150 g of deionized water, 0.5 g of AEO-9 and 1 g of OP-10 were added to reactor B and dispersed evenly, 2 g of dioxane was added, the temperature was controlled at 80°C, the reaction was kept warm for 1 h, 0.04 g of azobisisobutylamidine hydrochloride was added, the reaction was kept warm for 2 h, the temperature was controlled at 40°C, glacial acetic acid was added for neutralization, and acrylate resin was obtained;

[0086] S4: Add 100 g of reaction solution 2 and 150 g of acrylic resin into reactor C, control the temperature to 50-60° C., and keep the temperature to react for 3-6 hours to obtain a darkening agent.

[0087] Comparative Example 4

[0088] Compared with Example 4, Comparative Example 4 only replaces the cationic darkening agent prepared in Example 1 added in Example 4 with an equal amount of the darkening agent prepared in Comparative Example 1, and the other components are completely consistent with Example 4.

[0089] Comparative Example 5

[0090] Compared with Example 4, Comparative Example 5 only replaces the cationic darkening agent prepared in Example 1 added in Example 4 with an equal amount of the darkening agent prepared in Comparative Example 2, and the remaining components are completely consistent with Example 4.

[0091] Comparative Example 6

[0092] Compared with Example 4, Comparative Example 6 only replaces the cationic darkening agent prepared in Example 1 added in Example 4 with an equal amount of the darkening agent prepared in Comparative Example 3, and the other components are completely consistent with Example 4.

[0093] Comparative Example 7

[0094] Compared with Example 7, Comparative Example 7 only replaces the coating composition with light absorption deepening function prepared in Example 6 used in Example 7 with an equal amount of the coating composition with light absorption deepening function prepared in Comparative Example 4, and the remaining components and preparation methods are exactly the same as those of Example 7.

[0095] Comparative Example 8

[0096] Compared with Example 7, Comparative Example 8 only replaces the coating composition with light absorption depth enhancement function prepared in Example 6 used in Example 7 with an equal amount of the coating composition with light absorption depth enhancement function prepared in Comparative Example 5, and the remaining components and preparation method are exactly the same as those in Example 7.

[0097] Comparative Example 9

[0098] Compared with Example 7, Comparative Example 9 only replaces an equal amount of the coating composition with light absorption deepening function prepared in Example 6 used in Example 7 with the coating composition with light absorption deepening function prepared in Comparative Example 6, and the remaining components and preparation methods are exactly the same as those in Example 7.

[0099] Performance Testing

[0100] (1) Sublimation fastness: Tested in accordance with GB / T 5718-1997 “Textiles - Tests for colour fastness - Colour fastness to dry heat (excluding hot pressing)”, treated at 180°C for 30s on a sublimation fastness meter, and rated according to GB 250-1995 “Grey Scale for Assessment of Change in Colour” and GB251-1995 “Grey Scale for Assessment of Staining”; the test results are shown in Table 1;

[0101] (2) K / S and ΔE: According to GB / T 6529-2008 "Standard atmosphere for conditioning and testing of textiles", the tested fabrics were conditioned for 24 hours and then tested at multiple points using an UltraScanXE computer colorimeter with an aperture of 20 mm, a D65 light source, and a viewing angle of 10°, with the original sample as the standard sample and the finished sample as the batch sample. The color difference ΔE and K / S were calculated using the following formulas. The test results are shown in Table 1.

[0102] Table 1: Statistical table of sublimation fastness test data of Examples 7-9 and Comparative Examples 7-9

[0103]

[0104]

[0105] The coating of the present application is used to darken the fabric, and a layer of low refractive index film is covered on the surface of the fabric, which reduces the reflectivity of the fabric surface and increases the dyeing depth of the fabric. After the fabric is darkened, the K / S value of the finished fabric is significantly improved, and the sublimation fastness is improved, but the absorption wavelength and color light are not changed.

[0106] (3) Washing fastness test: GB / T 12490-2007 "Textiles - Tests for colour fastness - Colour fastness to domestic and commercial washing" A2S test is carried out to test the colour depth of the fabric before and after washing, recorded as (K / S)1 and (K / S)2 respectively, and the colour reduction of the fabric η is calculated according to the following formula:

[0107] η={[(K / S)1-(K / S)2] / [(K / S)1-(K / S)0]}×100%

[0108] Wherein, (K / S)2-apparent color depth of the finished fabric after washing; (K / S)1-apparent color depth of the finished fabric; the test results are shown in Table 2;

[0109] (4) Color fastness to rubbing: Tested according to GB / T 3920-2008 “Textiles - Tests for Color Fastness - Color Fastness to Rubbing” and rated according to GB251-1995 “Grey Scale for Staining”. The test results are shown in Table 2.

[0110] Table 2: Statistical table of color fastness test data of Examples 7-9 and Comparative Examples 7-9

[0111]

[0112]

[0113] As can be seen from Table 2, the coating composition prepared in the present application is used for darkening finishing of dyed fabrics. The fabrics after darkening finishing have excellent water resistance and friction resistance, so that the fabrics continue to maintain a good darkening effect in practical applications.

[0114] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A coating composition having a light absorption enhancement function, characterized in that: The coating composition includes a cationic darkening agent; the cationic darkening agent accounts for 50-60% of the total weight of the coating composition; The preparation method of the cationic darkening agent comprises the following steps: S1: Add polyethylene glycol, isophorone diisocyanate and N-methylpyrrolidone into reactor A, control the temperature at 60-70°C, and keep the temperature for reaction for 1-3h; add N-methyldiethanolamine, control the temperature at 60-70°C, and keep the temperature for reaction for 1-3h; continue to add butanone oxime, control the temperature at 40-50°C, and keep the temperature for reaction for 3-6h to obtain reaction solution 1; S2: Add amino-modified silica to reactor A, control the temperature at 60-70°C, and keep the temperature for reaction for 1-3 hours; control the temperature at 50-60°C, add glacial acetic acid, keep the temperature for reaction for 0.5-1 hour, and add deionized water to obtain reaction solution 2; S3: Add azobisisobutylamidine hydrochloride component 1, methyl methacrylate, isobutyl methacrylate, propyl methacrylate, deionized water and emulsifier into reactor B and disperse them evenly, add dioxane, control the temperature at 80-90°C, keep the temperature for reaction for 1-3h, add azobisisobutylamidine hydrochloride component 2, continue to keep the temperature for reaction for 2-4h, control the temperature at 40-50°C, add glacial acetic acid for neutralization, and obtain acrylate resin; S4: Add the reaction solution 2 and the acrylic resin into the reaction kettle C, control the temperature to 50-60°C, and keep the temperature to react for 3-6 hours to obtain a cationic darkening agent; The preparation method of amino-modified silica comprises the following steps: adding anhydrous ethanol, ethyl orthosilicate and γ-aminopropyltriethoxysilane into a reaction bottle and dispersing them uniformly, controlling the temperature at 50-60° C., adding an ammonia solution, keeping the temperature for reaction for 6-9 hours, centrifuging, washing and drying to obtain amino-modified silica.

2. A coating composition having a light absorption enhancement function according to claim 1, characterized in that: The coating composition further comprises: a binder, a thickener and water; the binder accounts for 20-30% of the total weight of the coating composition; the thickener accounts for 3-5% of the total weight of the coating composition; the balance is water, and the sum of the weight percentages of each component is 100%.

3. The coating composition having light absorption enhancement function according to claim 1, characterized in that: The addition ratio of polyethylene glycol, isophorone diisocyanate, N-methylpyrrolidone, N-methyldiethanolamine, butanone oxime, amino-modified silica, and glacial acetic acid in the materials of S1 and S2 is 10g: 5-8g: 100-200mL: 2-3.5g: 1.5-2g: 10-30g: 0.5-1g.

4. The coating composition having light absorption enhancement function according to claim 1, characterized in that: The emulsifier in S3 is obtained by mixing AEO-9 and OP-10 in a ratio of 1:1-2; the mass ratios of azobisisobutylamidine hydrochloride component one, methyl methacrylate, isobutyl methacrylate, propyl methacrylate, deionized water, emulsifier, dioxane, and azobisisobutylamidine hydrochloride component two are 0.04-0.1g: 10-25g: 1-2g: 5-8g: 150-250g: 1-1.5g: 2g: 0.04-0.1g.

5. The coating composition having light absorption enhancement function according to claim 1, characterized in that: The mass ratio of reaction solution 2 to acrylate resin in S4 is 1:0.5-1.

5.

6. The coating composition having light absorption enhancement function according to claim 1, characterized in that: The ammonia solution is obtained by mixing deionized water, 25-30wt% ammonia water and anhydrous ethanol in a volume ratio of 1:0.8-1.2:3; the volume ratio of anhydrous ethanol, ethyl orthosilicate, γ-aminopropyltriethoxysilane and ammonia solution is 100-150mL:10mL:0.4-2.2mL:50-75mL.

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