Stilbene biphenyl whitening composition and preparation method thereof

Abstract

The invention relates to the field of fluorescent whitening, and discloses a stilbene biphenyl whitening composition and a preparation method thereof, the stilbene biphenyl whitening composition comprises the following components by weight: 40-60 parts of a fluorescent whitening agent, 10-20 parts of modified montmorillonite, 3-8 parts of polyvinyl alcohol, 2-5 parts of a cosolvent, and 30-45 parts of deionized water; the modified montmorillonite is prepared by performing a grafting reaction on aminated nano montmorillonite and a polymer by utilizing a chemical reaction, and the polymer is prepared by mixing a quaternary ammonium salt antibacterial monomer, modified nano titanium dioxide, methyl methacrylate, butyl acrylate and maleic anhydride, and performing extrusion molding. According to the invention, the cotton fabric is endowed with excellent whitening effect, antibacterial property and washable effect by adding the fluorescent whitening agent and the modified montmorillonite, and the ultraviolet protection effect is good.

Description

Technical Field

[0001] The invention belongs to the technical field of fluorescent whitening, and in particular relates to a distyryl biphenyl whitening composition and a preparation method thereof. Background Art

[0002] Fluorescent whitening agents are organic compounds with a special structure that contains conjugated double bonds and has good planarity. Under sunlight, it can absorb ultraviolet rays (wavelength of 300-400nm) to excite the molecules. When it returns to the ground state, part of the ultraviolet energy disappears and is converted into blue-violet light with lower energy (wavelength of 420-480nm) for emission. In this way, the amount of blue-violet light reflected on the object is increased, thereby offsetting the yellow sense caused by the large amount of yellow light reflected on the original object, and visually producing a white and dazzling effect. Fluorescent whitening agents are divided into diphenylethylene type, naphthalimide type, coumarin type, quaternary ammonium salt type, pyrazoline type, benzoxazole type, etc. according to their structure. Among them, diphenylethylene type fluorescent whitening agents are the most commonly used, occupying the vast majority of the market share.

[0003] The color and stability of textile yarns and fabrics are one of the most important factors affecting consumers' daily lives, and directly determine the visual effects and product added value of textiles. However, many textile fabrics have color defects due to various factors, so that their use value is limited to a certain extent. In particular, the most commonly used cotton fabrics, when not processed, cause serious yellowing due to the presence of substances such as protein and certain natural pigments. Therefore, cotton fabrics are usually subjected to special processing to meet consumers' requirements for their whiteness. Among many treatment methods, whitening with fluorescent whitening agents is considered to be the most direct and effective method. In the existing research field of textile whitening agents, diphenylethylene fluorescent whitening agents have the disadvantages of poor water solubility, weak fiber binding ability, poor washability, unstable whiteness, etc., and cotton fabrics are easily contaminated by external liquids and human secretions, which leads to the growth and spread of microorganisms. The microorganisms growing on textiles will destroy the fabric morphology and cause the fabric to fade. In severe cases, they will also cause allergic reactions in the human body and even affect health. Summary of the invention

[0004] In order to solve the deficiencies mentioned in the above background technology, the purpose of the present invention is to provide a distyryl biphenyl whitening composition and a preparation method thereof, which gives cotton fabrics excellent whitening effect, antibacterial property and water washability by adding fluorescent brightener and modified montmorillonite, and has good UV protection effect.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A distyryl biphenyl whitening composition comprises the following components in parts by weight: 40-60 parts of a fluorescent whitening agent, 10-20 parts of modified montmorillonite, 3-8 parts of polyvinyl alcohol, 2-5 parts of a cosolvent, and 30-45 parts of deionized water; The modified montmorillonite is a modified montmorillonite prepared by grafting an amination nano-montmorillonite with a polymer by chemical reaction, wherein the polymer is a polymer prepared by mixing a quaternary ammonium salt antibacterial monomer, modified nano-titanium dioxide, methyl methacrylate, butyl acrylate and maleic anhydride under the action of an initiator azobisisobutyronitrile; The quaternary ammonium salt antibacterial monomer is a quaternary ammonium salt antibacterial monomer synthesized by using 2-hydroxymethyl pyridine, dodecane bromide and isocyanoethyl methacrylate; the modified nano titanium dioxide is a modified nano titanium dioxide synthesized by using isophorone diisocyanate and hydroxyethyl methacrylate to react and then graft nano titanium dioxide.

[0006] Preferably, the preparation method of the modified montmorillonite comprises the following steps: A. Put 2-hydroxymethylpyridine and dodecane bromide into a reactor containing 1,4-dioxane, and stir the reaction at 95-120° C. for 42-48 hours. After the reaction is completed, the mixture is subjected to rotary evaporation, washing, suction filtration, and drying to prepare 1-dodecyl-2-(hydroxymethyl)pyridinium bromide quaternary ammonium salt; B. Take 1-dodecyl-2-(hydroxymethyl)pyridinium bromide quaternary ammonium salt in a reactor, add dibutyltin dilaurate, hydroquinone and dichloromethane, stir at 25-30°C until completely dissolved, then heat to 35-45°C, add isocyanoethyl methacrylate, stir and react for 4-6 hours, and after the reaction is completed, perform rotary evaporation, wash and dry to prepare a quaternary ammonium salt antibacterial monomer; C. Place quaternary ammonium salt antibacterial monomer, modified nano titanium dioxide, methyl methacrylate, butyl acrylate and maleic anhydride in a reactor, add N,N-dimethylformamide solvent, heat to 60-75° C., add azobisisobutyronitrile solution dissolved in N,N-dimethylformamide, stir and reflux for 8-10 hours to prepare a polymer solution; D. Ultrasonic dispersion of nano-montmorillonite in a mixed solution of ethanol and deionized water, add γ-aminopropyltriethoxysilane, adjust the pH value to 4-5.5 with glacial acetic acid, and then place it at 60-85°C for stirring and reacting for 2-4 hours. After the reaction is completed, wash, centrifuge and dry to obtain amino-modified nano-montmorillonite. Ultrasonic dispersion of the amino-modified nano-montmorillonite in the polymer solution, stir at room temperature for 4-5 hours, and then filter, wash and dry to prepare modified montmorillonite.

[0007] Preferably, in step A, the molar ratio of 2-hydroxymethylpyridine to dodecane bromide is 1:1.8-2.3.

[0008] Preferably, in step B, the molar ratio of 1-dodecyl-2-(hydroxymethyl)pyridinium bromide quaternary ammonium salt to isocyanoethyl methacrylate is 1:1-1.2.

[0009] Preferably, in step C, the mass ratio of the quaternary ammonium salt antibacterial monomer, modified nano titanium dioxide, methyl methacrylate, butyl acrylate and maleic anhydride is 3.5-4:3-4:0.5-1:0.6-1.3:1-2.

[0010] Preferably, the preparation method of modified nano titanium dioxide in step C comprises the following steps: C1. Put isophorone diisocyanate in a reactor, add anhydrous butyl acetate solvent and stir to mix, then add dibutyltin dilaurate, raise the temperature to 40-50°C, add hydroxyethyl methacrylate and stir to react for 5-6 hours to obtain modified isophorone diisocyanate; C2. Ultrasonic dispersion of nano titanium dioxide in anhydrous butyl acetate, heating to 65-75°C, adding dibutyltin dilaurate to obtain a dispersion, mixing modified isophorone diisocyanate and anhydrous butyl acetate evenly and adding them to the dispersion, stirring to react for 10-12 hours, and after the reaction is completed, filtering, washing and drying to prepare modified nano titanium dioxide.

[0011] Preferably, in the step C1, the mass ratio of isophorone diisocyanate to hydroxyethyl methacrylate is 1:0.55-0.8; and in the step C2, the mass ratio of nano-titanium dioxide to modified isophorone diisocyanate is 1:5-7.

[0012] Preferably, the preparation method of the fluorescent whitening agent comprises the following steps: (1) Take biphenyl dichloride in a reactor, place it at 110-120°C, stir and dissolve, add trimethyl phosphite, reflux for 4-6 hours, distill under reduced pressure after the reaction is completed, cool to 98-105°C, add toluene and stir evenly, cool to room temperature for crystallization, filter and dry the precipitated solid to prepare 4,4′-bis(dimethoxyphosphonomethyl)biphenyl; (2) Place 4,4′-bis(dimethoxyphosphonomethyl)biphenyl in a reactor, add dimethyl sulfoxide and sodium benzaldehyde-2,4-disulfonate, stir and mix at 35-45°C, then add sodium methoxide and stir to react for 5-6 hours, pour the reaction solution into a mixture of ethanol and deionized water, cool and crystallize, filter, and vacuum dry to prepare a fluorescent whitening agent.

[0013] Preferably, the co-solvent is one of isopropanol, ethylene glycol and ethanol.

[0014] The preparation method of the distyryl biphenyl whitening composition as described above comprises the following steps: weighing each component by weight, stirring and mixing the fluorescent whitening agent, modified montmorillonite, polyvinyl alcohol, a cosolvent and deionized water, and obtaining the distyryl biphenyl whitening composition after stirring.

[0015] Beneficial effects of the present invention: The invention uses 4,4'-bis(dimethoxyphosphonomethyl)biphenyl and sodium benzaldehyde-2,4-disulfonate to synthesize a fluorescent whitening agent containing four -SO3Na water-soluble groups, thereby improving the water solubility of the fluorescent whitening agent and increasing the bonding strength between the fluorescent whitening agent and fabric fibers. In addition, the invention uses isophorone diisocyanate and hydroxyethyl methacrylate to react to obtain semi-enclosed modified isophorone diisocyanate, and then uses the isocyanate in the modified isophorone diisocyanate structure to undergo a grafting reaction with the hydroxyl group on the surface of nano titanium dioxide to obtain modified nano titanium dioxide containing a double bond structure.

[0016] The invention uses 2-hydroxymethylpyridine and dodecane bromide to react to synthesize 1-dodecyl-2-(hydroxymethyl)pyridinium bromide quaternary ammonium salt, then the hydroxyl group in the structure of the 1-dodecyl-2-(hydroxymethyl)pyridinium bromide quaternary ammonium salt is subjected to grafting reaction with the isocyanate group in the structure of isocyanoethyl methacrylate under the action of a catalyst, dibutyltin dilaurate, and a polymerization inhibitor, hydroquinone, to synthesize a quaternary ammonium salt antibacterial monomer containing a double bond structure, then the quaternary ammonium salt antibacterial monomer, modified nano titanium dioxide, methyl methacrylate, butyl acrylate and maleic anhydride are mixed, and a polymer solution is obtained under the action of an initiator, azobisisobutyronitrile, and at the same time, the invention uses gamma-aminopropyltriethoxysilane to prepare aminoated nano-montmorillonite, then the aminoated nano-montmorillonite reacts with the polymer solution to graft the polymer onto the surface of the nano-montmorillonite, and the modified nano-montmorillonite is prepared. Wherein nano-montmorillonite has good affinity with fabric fiber, the effective ingredient of brightener enters between the layers of nano-montmorillonite, so that brightener stability is excellent, fabric whitening performance is good, and there are a large amount of active groups between the nano-montmorillonite layers and layers that can react with the hydroxyl on the fabric, so that the fabric washability after whitening is good, nano titanium dioxide whiteness is high, tinting power is strong, it is as conventional inorganic ultraviolet screening agent, has antibacterial, deodorizing, mildew-proof and other effects, can absorb and scatter ultraviolet rays, effectively resist the harm of ultraviolet rays, quaternary ammonium salt functional group has broad-spectrum antibacterial effect in addition, can give cotton fabric good antibacterial effect, and due to the firm combination of chemical bond, avoid the precipitation problem of quaternary ammonium salt antibacterial monomer. The present invention is added with polyvinyl alcohol in addition, polyvinyl alcohol is a kind of water-soluble polymer, has good film-forming property and elasticity, and the hydroxyl in the polyvinyl alcohol structure can react with the amino group on the amination nano-montmorillonite surface to form the hydrogen bond of interpenetrating polymer network. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe 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.

[0018] Example 1 A method for preparing modified montmorillonite comprises the following steps: A. Take 5.457g 2-hydroxymethylpyridine and 24.923g dodecane bromide and put them into a reactor containing 100mL 1,4-dioxane, place it at 105°C and stir for 45h. After the reaction is completed, it is rotary evaporated, washed, filtered and dried to prepare 1-dodecyl-2-(hydroxymethyl)pyridinium bromide quaternary ammonium salt; B. Take 3.58g of 1-dodecyl-2-(hydroxymethyl)pyridinium bromide quaternary ammonium salt in a reactor, add 0.001g of dibutyltin dilaurate, 0.024g of hydroquinone and 10mL of dichloromethane, stir at 30°C until completely dissolved, then heat to 45°C, add 1.56g of isocyanoethyl methacrylate, stir and react for 6h, after the reaction is completed, rotary evaporate, wash and dry to prepare a quaternary ammonium salt antibacterial monomer; C. Take 3.584g of quaternary ammonium salt antibacterial monomer, 3.2g of modified nano titanium dioxide, 0.65g of methyl methacrylate, 0.74g of butyl acrylate and 1.2g of maleic anhydride in a reactor, add 120mL of N,N-dimethylformamide solvent, heat to 70°C, add 0.2g of azobisisobutyronitrile solution dissolved in 40mL of N,N-dimethylformamide, stir and reflux for 10h to prepare a polymer solution; D. Take 5g of nano-montmorillonite and ultrasonically disperse it in a mixed solution of 180mL of ethanol and 20mL of deionized water, add 3g of γ-aminopropyltriethoxysilane, adjust the pH value to 5 with glacial acetic acid, and then place it at 75°C for stirring and reacting for 4h. After the reaction is completed, wash, centrifuge and dry to obtain amino-modified nano-montmorillonite. Ultrasonic disperse the amino-modified nano-montmorillonite in 150g of polymer solution, stir at room temperature for 5h, and then filter, wash and dry to prepare modified montmorillonite.

[0019] A method for preparing modified nano titanium dioxide comprises the following steps: C1. Take 10 g of isophorone diisocyanate in a reactor, add 40 mL of anhydrous butyl acetate solvent and stir to mix, then add 0.2 g of dibutyltin dilaurate, raise the temperature to 45° C., add 7.5 g of hydroxyethyl methacrylate and stir to react for 6 h to obtain modified isophorone diisocyanate; C2. Take 2g of nano-titanium dioxide and ultrasonically disperse it in 80mL of anhydrous butyl acetate. Heat it to 75°C, add 0.03g of dibutyltin dilaurate to obtain a dispersion, take 12.7g of modified isophorone diisocyanate and 40mL of anhydrous butyl acetate, mix them evenly and add them to the dispersion, stir and react for 12h, and after the reaction is completed, filter, wash and dry to prepare modified nano-titanium dioxide.

[0020] Example 2 A method for preparing a fluorescent whitening agent comprises the following steps: (1) 25.1 g of dichlorobiphenyl was placed in a reactor, stirred and dissolved at 115°C, 38 mL of trimethyl phosphite was added, and the reaction was refluxed for 6 h. After the reaction was completed, the reaction was distilled under reduced pressure, cooled to 100°C, 60 mL of toluene was added, and stirred evenly. The reaction was cooled to room temperature for crystallization, and the precipitated solid was filtered and dried to prepare 4,4′-bis(dimethoxyphosphonomethyl)biphenyl; (2) Take 32g of 4,4′-bis(dimethoxyphosphonomethyl)biphenyl in a reactor, add 150mL of dimethyl sulfoxide and 48g of sodium benzaldehyde-2,4-disulfonate, stir and mix at 40°C, then add 9g of sodium methoxide and stir to react for 5h, pour the reaction solution into a mixture of ethanol and deionized water, cool and crystallize, filter, and vacuum dry to prepare a fluorescent whitening agent.

[0021] Example 3 A distyryl biphenyl whitening composition comprises the following components in parts by weight: 42 parts of the fluorescent whitening agent prepared in Example 2, 10 parts of the modified montmorillonite prepared in Example 1, 3 parts of polyvinyl alcohol, 2 parts of co-solvent isopropyl alcohol, and 34 parts of deionized water.

[0022] The preparation method of the above-mentioned distyryl biphenyl whitening composition comprises the following steps: The components are weighed in parts by weight, and the fluorescent brightener, modified montmorillonite, polyvinyl alcohol, a cosolvent and deionized water are stirred and mixed. After the stirring is completed, the distyryl biphenyl whitening composition is obtained.

[0023] Example 4 A distyryl biphenyl whitening composition comprises the following components in parts by weight: 48 parts of the fluorescent whitening agent prepared in Example 2, 15 parts of the modified montmorillonite prepared in Example 1, 5 parts of polyvinyl alcohol, 4 parts of co-solvent isopropanol, and 40 parts of deionized water.

[0024] The preparation method of the above-mentioned distyryl biphenyl whitening composition is the same as that of Example 3.

[0025] Example 5 A distyryl biphenyl whitening composition comprises the following components in parts by weight: 55 parts of the fluorescent whitening agent prepared in Example 2, 20 parts of the modified montmorillonite prepared in Example 1, 8 parts of polyvinyl alcohol, 5 parts of co-solvent isopropyl alcohol, and 42 parts of deionized water.

[0026] The preparation method of the above-mentioned distyryl biphenyl whitening composition is the same as that of Example 3.

[0027] Comparative Example 1 A method for preparing modified montmorillonite. Compared with Example 1, the method for preparing modified montmorillonite in Comparative Example 1 does not add modified nano titanium dioxide component, and the remaining components and steps are completely consistent with those in Example 1.

[0028] Comparative Example 2 A method for preparing modified montmorillonite. Compared with Example 1, the method for preparing modified montmorillonite in Comparative Example 2 does not add a quaternary ammonium salt antibacterial monomer component, and the remaining components and steps are completely consistent with Example 1.

[0029] Comparative Example 3 A distyryl biphenyl whitening composition comprises the following components in parts by weight: 55 parts of the fluorescent whitening agent prepared in Example 2, 20 parts of the modified montmorillonite prepared in Comparative Example 1, 8 parts of polyvinyl alcohol, 5 parts of co-solvent isopropyl alcohol, and 42 parts of deionized water.

[0030] The preparation method of the above-mentioned distyryl biphenyl whitening composition is the same as that of Example 3.

[0031] Comparative Example 4 A distyryl biphenyl whitening composition comprises the following components in parts by weight: 55 parts of the fluorescent whitening agent prepared in Example 2, 20 parts of the modified montmorillonite prepared in Comparative Example 2, 8 parts of polyvinyl alcohol, 5 parts of co-solvent isopropyl alcohol, and 42 parts of deionized water.

[0032] The preparation method of the above-mentioned distyryl biphenyl whitening composition is the same as that of Example 3.

[0033] Performance Testing A cotton fabric sample (4 cm × 4 cm, whiteness 104) was washed and dried to remove impurities, and then immersed in the whitening composition prepared in Example 3-5 and Comparative Example 3-4. The cotton fabric was impregnated and the solution was stirred for 15 minutes, ultrasonically dispersed for 30 minutes to ensure uniform distribution, and then pre-dried at 80°C for 5 minutes, and high-temperature cured at 160°C for 2 minutes to obtain cotton fabric treated with the whitening composition, and performance testing was performed.

[0034] (1) Determination of whiteness: The whiteness of the fabric was tested using a DF-100 spectrophotometer. The data results are shown in Table 1.

[0035] (2) Color fastness to washing with soap: With reference to GB / T 3921-2008 “Textiles - Tests for color fastness - Color fastness to washing with soap”, the test was carried out using a washing color fastness tester. The data results are shown in Table 1.

[0036] (3) Color fastness to sunlight: Refer to GB / T 8427-2019 "Textiles - Tests for color fastness - Color fastness to artificial light: Xenon arc fading lamp" Method 3, and use a sunlight fastness climate tester for testing. The data results are shown in Table 1.

[0037] (4) Color fastness to perspiration: With reference to GB / T 3922-2013 “Textiles - Tests for color fastness - Color fastness to perspiration”, the test was carried out using a perspiration fastness meter. The data results are shown in Table 1.

[0038] Table 1 Test results of sample performance

[0039] It can be seen from the data in Table 1 that the cotton fabrics treated with the whitening compositions prepared in Examples 3-5 of the present invention have high whiteness, and their color fastness to soaping, sunlight and perspiration all reach level 4-5.

[0040] (5) Antibacterial property test: According to the test method in GB / T 20944.3-2008 “Evaluation of antibacterial properties of textiles Part 3: Oscillation method”, Staphylococcus aureus and Escherichia coli were used to test the antibacterial properties of cotton fabrics. The data results are shown in Table 2.

[0041] (6) UV protection effect test: Referring to GB / T 18830-2009, the UPF value was determined using a textile UV protection performance tester. The test wavelength range was 280~400nm, the test temperature was 20±2℃, and the relative humidity was 65±4%. The data results are shown in Table 2.

[0042] Table 2 Test results of antibacterial properties and UV protection effects of samples

[0043] From the data in Table 2, it can be seen that the cotton fabric treated with the whitening composition prepared in Examples 3-5 of the present invention has excellent antibacterial and water-resistant effects, and has good ultraviolet protection effects. In Comparative Example 3, no modified nano titanium dioxide component was added, and the antibacterial rate measured was slightly worse than that of Examples 3-5, and the ultraviolet protection effect was significantly reduced. In Comparative Example 4, no quaternary ammonium salt antibacterial monomer component was added, and the antibacterial rate measured was significantly reduced compared with Examples 3-5.

[0044] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0045] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A distyryl biphenyl whitening composition, characterized in that: The invention comprises the following components in parts by weight: 40-60 parts of fluorescent whitening agent, 10-20 parts of modified montmorillonite, 3-8 parts of polyvinyl alcohol, 2-5 parts of cosolvent and 30-45 parts of deionized water; The modified montmorillonite is a modified montmorillonite prepared by grafting an amination nano-montmorillonite with a polymer by chemical reaction, wherein the polymer is a polymer prepared by mixing a quaternary ammonium salt antibacterial monomer, modified nano-titanium dioxide, methyl methacrylate, butyl acrylate and maleic anhydride under the action of an initiator azobisisobutyronitrile; The quaternary ammonium salt antibacterial monomer is a quaternary ammonium salt antibacterial monomer synthesized by using 2-hydroxymethyl pyridine, dodecane bromide and isocyanoethyl methacrylate; the modified nano titanium dioxide is a modified nano titanium dioxide synthesized by using isophorone diisocyanate and hydroxyethyl methacrylate to react and then graft nano titanium dioxide.

2. The distyryl biphenyl whitening composition according to claim 1, characterized in that: The preparation method of the modified montmorillonite comprises the following steps: A. Put 2-hydroxymethylpyridine and dodecane bromide into a reactor containing 1,4-dioxane, and stir the reaction at 95-120° C. for 42-48 hours. After the reaction is completed, the mixture is subjected to rotary evaporation, washing, suction filtration, and drying to prepare 1-dodecyl-2-(hydroxymethyl)pyridinium bromide quaternary ammonium salt; B. Take 1-dodecyl-2-(hydroxymethyl)pyridinium bromide quaternary ammonium salt in a reactor, add dibutyltin dilaurate, hydroquinone and dichloromethane, stir at 25-30°C until completely dissolved, then heat to 35-45°C, add isocyanoethyl methacrylate, stir and react for 4-6 hours, and after the reaction is completed, perform rotary evaporation, wash and dry to prepare a quaternary ammonium salt antibacterial monomer; C. Place quaternary ammonium salt antibacterial monomer, modified nano titanium dioxide, methyl methacrylate, butyl acrylate and maleic anhydride in a reactor, add N,N-dimethylformamide solvent, heat to 60-75° C., add azobisisobutyronitrile solution dissolved in N,N-dimethylformamide, stir and reflux for 8-10 hours to prepare a polymer solution; D. Ultrasonic dispersion of nano-montmorillonite in a mixed solution of ethanol and deionized water, add γ-aminopropyltriethoxysilane, adjust the pH value to 4-5.5 with glacial acetic acid, and then place it at 60-85°C for stirring and reacting for 2-4 hours. After the reaction is completed, wash, centrifuge and dry to obtain amino-modified nano-montmorillonite. Ultrasonic dispersion of the amino-modified nano-montmorillonite in the polymer solution, stir at room temperature for 4-5 hours, and then filter, wash and dry to prepare modified montmorillonite.

3. The distyryl biphenyl whitening composition according to claim 2, characterized in that: The molar ratio of 2-hydroxymethylpyridine to dodecane bromide in step A is 1:1.8-2.

3.

4. The distyryl biphenyl whitening composition according to claim 2, characterized in that: In the step B, the molar ratio of 1-dodecyl-2-(hydroxymethyl)pyridinium bromide quaternary ammonium salt to isocyanoethyl methacrylate is 1:1-1.

2.

5. The distyryl biphenyl whitening composition according to claim 2, characterized in that: In the step C, the mass ratio of the quaternary ammonium salt antibacterial monomer, the modified nano titanium dioxide, methyl methacrylate, butyl acrylate and maleic anhydride is 3.5-4:3-4:0.5-1:0.6-1.3:1-2.

6. The distyryl biphenyl whitening composition according to claim 2, characterized in that: The preparation method of modified nano titanium dioxide in step C comprises the following steps: C1. Put isophorone diisocyanate in a reactor, add anhydrous butyl acetate solvent and stir to mix, then add dibutyltin dilaurate, raise the temperature to 40-50°C, add hydroxyethyl methacrylate and stir to react for 5-6 hours to obtain modified isophorone diisocyanate; C2. Ultrasonic dispersion of nano titanium dioxide in anhydrous butyl acetate, heating to 65-75°C, adding dibutyltin dilaurate to obtain a dispersion, mixing modified isophorone diisocyanate and anhydrous butyl acetate evenly and adding them to the dispersion, stirring to react for 10-12 hours, and after the reaction is completed, filtering, washing and drying to prepare modified nano titanium dioxide.

7. The distyryl biphenyl whitening composition according to claim 6, characterized in that: The mass ratio of isophorone diisocyanate to hydroxyethyl methacrylate in step C1 is 1:0.55-0.8; the mass ratio of nano titanium dioxide to modified isophorone diisocyanate in step C2 is 1:5-7.

8. The distyryl biphenyl whitening composition according to claim 1, characterized in that: The preparation method of the fluorescent whitening agent comprises the following steps: (1) Take biphenyl dichloride in a reactor, place it at 110-120°C, stir and dissolve, add trimethyl phosphite, reflux for 4-6 hours, distill under reduced pressure after the reaction is completed, cool to 98-105°C, add toluene and stir evenly, cool to room temperature for crystallization, filter and dry the precipitated solid to prepare 4,4′-bis(dimethoxyphosphonomethyl)biphenyl; (2) Place 4,4′-bis(dimethoxyphosphonomethyl)biphenyl in a reactor, add dimethyl sulfoxide and sodium benzaldehyde-2,4-disulfonate, stir and mix at 35-45°C, then add sodium methoxide and stir to react for 5-6 hours, pour the reaction solution into a mixture of ethanol and deionized water, cool and crystallize, filter, and vacuum dry to prepare a fluorescent whitening agent.

9. The distyryl biphenyl whitening composition according to claim 1, characterized in that: The co-solvent is one of isopropanol, ethylene glycol and ethanol.

10. The method for preparing the distyryl biphenyl whitening composition according to claim 1, characterized in that: The following steps are involved: The components are weighed in parts by weight, and the fluorescent brightener, modified montmorillonite, polyvinyl alcohol, a cosolvent and deionized water are stirred and mixed. After the stirring is completed, the distyryl biphenyl whitening composition is obtained.

Images