Antibacterial finishing agent and application method thereof and antibacterial pure cotton towel

Abstract

The present invention belongs to the technical field of fabric treatment, and specifically relates to an antibacterial finishing agent, an application method thereof and an antibacterial pure cotton towel. The antibacterial finishing agent is obtained by reacting methylphenyldichlorosilane with p-hydroxyphenylhydantoin and 2,4-dihydroxybenzophenone to obtain solution A and solution B, and then mixing the two and evaporating the solvent to obtain. The application method is to prepare a finishing liquid with an antibacterial finishing agent and sodium hydroxide, apply the finishing liquid to a pure cotton fabric for finishing, and then directly or after drying the finished pure cotton fabric, treat it with an aqueous solution of hypochlorous acid, and finally obtain an antibacterial pure cotton fabric; the antibacterial pure cotton towel is one of the specific application methods. The antibacterial finishing agent in the present invention is simple to prepare and low in cost; in particular, an antibacterial pure cotton towel is obtained after finishing the pure cotton fabric, and the antibacterial and soft anti-wrinkle effects are good; and the antibacterial performance is less affected by ultraviolet rays and strong sunlight.

Description

Technical Field

[0001] The invention belongs to the technical field of fabric treatment, and particularly relates to an antibacterial finishing agent and an application method thereof, and an antibacterial pure cotton towel. Background Art

[0002] The survival and reproduction of bacteria in textiles can cause odor and even the spread of disease, so many textiles need to be given antibacterial properties; during the finishing process, antibacterial ingredients, especially organic antibacterial ingredients, are combined with the fiber surface of the textiles, and the resulting textile products have antibacterial properties.

[0003] The main types of organic antimicrobial agents include quaternary ammonium salts, biguanides (PHMB), and halogenamine compounds, among which halogenamine compounds have all the characteristics of ideal antimicrobial agents: excellent inhibition, sterilization, disinfection and deodorization functions, broad-spectrum antimicrobial effects on bacteria and fungi, and the effects are long-lasting and renewable; almost no toxic side effects on human skin, no environmental pollution; basically no effect on the quality of the textile itself; and relatively easy to use in combination with other finishing agents. The molecular structure of the halogenamine compound contains an NX group (X can be Cl, Br), which can be obtained by halogenating the amino group, amide group, and imide group in the halogenamine compound precursor with a hypohalite solution; the halogen cations dissociated from the NX group have strong oxidizing properties, which can kill bacteria, viruses and other microorganisms, and its antimicrobial properties are regenerative, and the used halogenamine compound can be restored by contacting it with a hypohalite aqueous solution for re-halogenation.

[0004] When preparing antibacterial cotton fabrics, reactive halamine compound precursors such as triazine derivatives, siloxane hydantoins, alkenyl hydantoins and hydroxymethyl hydantoins can be brought into contact with cotton fabrics. Some of them can directly react with the hydroxyl groups in the molecular structure of cotton fibers and be incorporated into the cotton fabrics, while others can react with the hydroxyl groups in the molecular structure of cotton fibers through, for example, 3-mercaptopropyltriethoxysilane and thiol-olefin Click reactions and be incorporated into the cotton fabrics.

[0005] Chinese patent CN108976213A discloses a halamine antibacterial agent containing a double active group, and a preparation method and application thereof. The structure of the halamine antibacterial agent is shown in the general formula (1) (R1 and R2 are each independently represented by Cl or Br). The preparation method of the halamine antibacterial agent comprises the following steps: (1) dissolving 5,5-dimethylhydantoin and 2-chloroethylamine hydrochloride in water or an organic solvent, then adding alkali, stirring and refluxing at 60-70°C for 12-16 hours, and after the reaction is completed, distilling off the solvent under reduced pressure, washing the initial product with acetone or ethanol, filtering, and distilling off the acetone or ethanol in the filtrate by reduced pressure distillation to obtain to aminoethyl hydantoin; (2) adding the suspension of p-(sodium β-ethylsulfone sulfate) aniline dropwise into water or an organic solvent containing cyanuric chloride, reacting at 0-5°C for 2-4 hours, and then adding the aqueous solution of aminoethyl hydantoin obtained in step (1), reacting at 30-50°C for 3-5 hours; adding an acid-binding agent dropwise to adjust the pH to 5.0-6.0, salting out and filtering after the reaction, purifying and drying to obtain a halamine antibacterial precursor (II); (3) placing the halamine antibacterial precursor (II) in an aqueous sodium hypochlorite solution, standing at 20-40°C for 0.5-4 hours, filtering after the reaction, and drying to obtain the halamine antibacterial agent. In step (1), the base is one or a mixture of sodium hydroxide and potassium hydroxide; the molar ratio of 5,5-dimethylhydantoin, 2-chloroethylamine hydrochloride and the base is 1:1:2; the organic solvent is one or more of ethanol, N,N-dimethylformamide and acetone, and the amount thereof is such that the concentration of the reaction raw materials in the solvent reaches 1-10w / v%. In step (2), the molar ratio of cyanuric chloride, p-(sodium β-ethylsulfone sulfate)aniline and aminoethylhydantoin is 1:1:1; the organic solvent is one or more of acetone, carbon tetrachloride, ether, ethanol, dioxane and chloroform; the concentration of cyanuric chloride in water or organic solvent is 1-20w / v%; the acid binding agent is one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate and sodium bicarbonate.

[0006] .

[0007] The application of the halamine antibacterial agent is a method for antibacterial finishing of textiles, comprising the following steps: (1) dissolving a halamine antibacterial precursor and a metal salt in water to obtain an antibacterial finishing solution, and immersing the textile to be treated in the finishing solution at room temperature for 10 to 60 minutes; (2) adding a solid alkali agent, immersing at 60 to 80° C. for 2 to 5 hours, taking out the textile, washing it with water, and drying it; (3) finally immersing the textile in a sodium hypochlorite solution with a concentration of 0.1 to 1 wt% for a halogenation reaction, taking it out and drying it to obtain an antibacterial textile. In step (1), the concentration of the halamine antibacterial agent precursor is 0.1 to 5% (w / v), and the metal salt is one or more of sodium sulfate, magnesium sulfate, zinc sulfate, sodium chloride, magnesium chloride, and calcium chloride, and the final concentration is 50 to 200 g / L; in step (2), the solid alkali agent is one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, and sodium bicarbonate, and the final concentration is 1 to 5 g / L.

[0008] Chinese patent CN106632259A discloses a triazine quaternary ammonium salt halogenamine antibacterial agent and its preparation method and salt-free antibacterial finishing method. The antibacterial agent is a compound of the structure shown in formula (I) (wherein R represents F or Cl; R1 and R2 each independently represent Cl or Br or H); the preparation method comprises the following steps: (1) dropping an organic solution of 2,2,6,6-tetramethyl-4-piperidinamine into a water or organic solution of cyanuric chloride or cyanuric fluoride, and reacting at 0-10°C for 1-4 hours; (2) pouring an aqueous solution of N-(2-ethylamino)-pyridine chloride into the solution; The mixture is added thereto, reacted at 30-60°C for 2-6 hours, and an acid binding agent is added dropwise during the entire reaction process to adjust the pH value to 5.0-8.0; (3) after the reaction is completed, the mixture is filtered, purified and dried to obtain a triazine quaternary ammonium salt halamine antibacterial precursor; (4) the triazine quaternary ammonium salt halamine antibacterial precursor is placed in a halogenated solution, allowed to stand at room temperature for 0.5-1.5 hours, filtered and dried to obtain a quaternary ammonium salt halamine antibacterial agent finished product; wherein the molar ratio of cyanuric chloride or cyanuric fluoride, 2,2,6,6-tetramethyl-4-piperidinamine and N-(2-ethylamino)-pyridine chloride is 1:1:1. The organic solvent for dissolving 2,2,6,6-tetramethyl-4-piperidinamine includes acetone, methanol, ethanol or chloroform, and the concentration of the organic solution of 2,2,6,6-tetramethyl-4-piperidinamine is 10-20% by w / v; the organic solvent for dissolving cyanuric chloride or cyanuric fluoride includes chloroform, acetone, carbon tetrachloride, ethanol, ether or dioxane, and the concentration of the water or organic solution of cyanuric chloride or cyanuric fluoride is 1-10% by w / v; the concentration of the aqueous solution of N-(2-ethylamino)-pyridine chloride is 20-40% by w / v; the acid binding agent is one of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate and sodium bicarbonate or a mixture thereof.

[0009] .

[0010] The salt-free antibacterial finishing method is applied in the antibacterial finishing of textiles, and comprises the following steps: (1) dissolving a triazine quaternary ammonium salt halamine antibacterial agent in water to prepare a finishing solution, immersing the to-be-treated fabric in the finishing solution, and treating at room temperature for 10-30 minutes, wherein the final concentration of the halamine antibacterial agent is w / v: 0.1-1%; (2) adding an alkali agent, immersing at 40-80°C for 2-6 hours, taking out the fabric, washing it with water and drying it, wherein the alkali agent is selected from one or a mixture of several of sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate and sodium bicarbonate, and the final concentration is 1-5 g / L; (3) finally immersing the fabric in a sodium hypochlorite solution or a trichloroisocyanuric acid solution with a concentration of 0.01-1 wt% to carry out a halogenation reaction, taking it out and drying it, thereby obtaining the antibacterial textile.

[0011] Chinese patent CN116283912A discloses an aminohydantoin Schiff base 4-pyridine quaternary ammonium salt precursor compound and its preparation method and application, which is prepared from aminohydantoin hydrochloride, 4-pyridine formaldehyde and propylene bromide as raw materials; the preparation method comprises the following steps: 1) adding aminohydantoin hydrochloride to water, adjusting the pH value to 6-7, and drying the water to obtain a mixture A; 2) dissolving the mixture A in hot ethanol, filtering, and obtaining a mixed solution B; 3) adding an acidic solution and 4-pyridine formaldehyde to the mixed solution B, and refluxing with ethanol to obtain a mixed solution C; filtering, and obtaining a compound D, which is aminohydantoin pyridine Schiff base; wherein 4-pyridine The amount of formaldehyde added is calculated based on the molar ratio of 4-pyridine formaldehyde to aminohydantoin hydrochloride being 1:1.1-1.2; 4) aminohydantoin pyridine Schiff base and allyl bromide are added to dimethyl sulfoxide, the molar concentration of aminohydantoin pyridine Schiff base is controlled to be 0.5-2 mol / L, and a mixture E is obtained; the mixture is washed with ethanol or ethyl acetate, filtered, and dried; deionized water is used as a solvent, and the product 1-(4-methyliminopyridine-1-allyl bromide)hydantoin is recrystallized to obtain an aminohydantoin Schiff base 4-pyridine quaternary ammonium salt precursor compound; wherein the amount of allyl bromide added is calculated based on the molar ratio of aminohydantoin pyridine Schiff base to allyl bromide being 1:1.2. In step 1), sodium hydroxide is used to adjust the pH value, and the molar ratio of aminohydantoin hydrochloride to sodium hydroxide is 1:1; in step 3), the acidic solution is a weak acid solution, preferably a glacial acetic acid solution; in step 3), ethanol is refluxed at 60-80° C. for 18 hours; in step 4), the reaction is carried out at 60-85° C. for 24 hours. The application of the aminohydantoin Schiff base 4-pyridine quaternary ammonium salt precursor compound is to prepare an antibacterial material, which includes the following steps: (1) soaking a material to be treated, such as cotton fabric, in a pretreatment solution and drying to obtain a pretreatment material; (2) immersing the pretreatment material in the antibacterial treatment solution at a bath ratio of 1:20-100, irradiating the pretreatment material with ultraviolet light for 60 minutes, washing, and drying to obtain an antibacterial finishing material; wherein the preparation method of the antibacterial finishing solution includes: dissolving the aminohydantoin Schiff base 4-pyridine quaternary ammonium salt precursor compound and a water-soluble photoinitiator 2,2-dihydroxymethylpropionic acid in water to form an aqueous solution, wherein the content of the photoinitiator in the aqueous solution is 1wt%; and (3) immersing the antibacterial finishing material in a halogenation reaction solution, reacting, washing, and drying to obtain an antibacterial material. In step (1), the preparation method of the pretreatment liquid is: ethanol and pure water are mixed in a volume ratio of 4:1, 3-mercaptopropyltriethoxysilane is added in an amount of 5%, the pH is adjusted to 3.5 with glacial acetic acid, and stirred with a magnetic stirrer for 30 minutes; in step (3), the preparation method of the halogenation reaction liquid is: glacial acetic acid is added to a sodium hypochlorite solution or a sodium hypobromite solution with a mass fraction of 10wt%, and the pH is adjusted to neutral.

[0012] The antimicrobial agents disclosed in the above-mentioned prior art and the finishing and application methods thereof in fabrics, especially pure cotton fabrics, basically realize and exert the effects and advantages of chloramine antimicrobial agents or chloramine-containing composite antimicrobial agents, but their application is limited by the following technical problems: (1) the preparation of antimicrobial agents is difficult, the production cost is high, the molecular structure of the effective antimicrobial components is relatively complex, and the yield is difficult to exceed 60%; (2) the antimicrobial properties of fabrics, especially pure cotton fabrics, applied with the antimicrobial agents, decrease significantly (by more than 20% or even more than 35%) after being dried under sunlight conditions, especially strong sunlight exposure such as 8 hours, that is, the antimicrobial properties are inconsistent with the commonly used sunlight disinfection and sterilization methods; (3) the finishing and application process is technically difficult.

[0013] Therefore, it is necessary to develop a chloramine antibacterial agent, which has a simple preparation process, low production cost, relatively simple molecular structure of effective antibacterial components, and a yield of more than 80%; cotton-containing fabrics, especially pure cotton fabrics, to which the antibacterial agent is applied, have a small decrease in antibacterial properties (within 10%) after being dried under sunlight, especially strong sunlight exposure such as 8 hours, and the antibacterial properties are not inconsistent with the sunlight disinfection and sterilization method; and conventional finishing and application processes can be used. Summary of the invention

[0014] To solve the above technical problems, the purpose of the present invention is to provide an antibacterial finishing agent and an application method thereof, which can be used for cotton-containing fabrics, especially pure cotton fabrics. The present invention also provides an antibacterial pure cotton towel.

[0015] To achieve the above object, the technical solution adopted by the present invention is:

[0016] The antibacterial finishing agent of the present invention is prepared by using methylphenyldichlorosilane, p-hydroxyphenylhydantoin and 2,4-dihydroxybenzophenone as synthetic reaction raw materials through the following steps:

[0017] (1) subjecting a stirred reactor A and its attached condenser A to dehydration and nitrogen replacement; injecting a tetrahydrofuran solution containing 25-35 wt% of p-hydroxyphenyl hydantoin into the reactor A, stirring continuously, heating the solution to a slight boiling temperature, and continuously injecting a tetrahydrofuran solution containing 30-40 wt% of methylphenyl dichlorosilane under the slight boiling condition, and controlling the injection time to be 5-7.5 h, and then continuing the reaction of the solution under the slight boiling condition for 0.5-1 h, cooling, and obtaining a solution A; wherein the molar ratio of p-hydroxyphenyl hydantoin to methylphenyl dichlorosilane is 1:(1.1-1.2);

[0018] (2) The stirred reactor B and its attached condenser B are subjected to anhydrous treatment and nitrogen replacement; a tetrahydrofuran solution containing 10-15 wt% of 2,4-dihydroxybenzophenone is injected into the reactor B, and stirring is continued. The solution is heated to a slight boiling temperature, and a tetrahydrofuran solution containing 30-40 wt% of methylphenyldichlorosilane is continuously injected under the slight boiling condition, and the injection time is controlled to be 5-8 hours. Thereafter, the solution is continued to react for 0.5-1 hour under the slight boiling condition, and the temperature is lowered to obtain a solution B; wherein the molar ratio of 2,4-dihydroxybenzophenone to methylphenyldichlorosilane is 1:(1.1-1.2);

[0019] (3) mixing solution A and solution B at a weight ratio of 100:(8-12) and evaporating the mixture to remove the tetrahydrofuran solvent and obtain an antibacterial finishing agent;

[0020] In steps (1)-(2), the condensation temperature of the condensers A and B is controlled at 10-25°C; during the slight boiling reaction of the solutions in reactors A and B, tetrahydrofuran is intermittently or continuously injected to maintain the volume and concentration of the solutions in reactors A and B unchanged; tetrahydrofuran vapor containing hydrogen chloride is continuously discharged from reactors A and B, which is condensed in condensers A and B respectively and then collected to obtain condensate A and condensate B, which are then sealed and stored in anoxic and anhydrous conditions respectively.

[0021] in:

[0022] The tetrahydrofuran solution containing 25-35 wt% of p-hydroxyphenylhydrazine in step (1) and the tetrahydrofuran solution containing 10-15 wt% of 2,4-dihydroxybenzophenone in step (2) are both pre-dehydrated with anhydrous calcium chloride or anhydrous sodium sulfate.

[0023] In the steps (1) and (2), the tetrahydrofuran vapor containing hydrogen chloride is condensed and collected by condensers A and B respectively, and stored in a closed manner under oxygen-free and water-free conditions. The hydrogen chloride is then removed by distillation to obtain a tetrahydrofuran solution containing methylphenyldichlorosilane, which is used to prepare a tetrahydrofuran solution containing 30-40 wt% of methylphenyldichlorosilane.

[0024] In the step (3), the tetrahydrofuran solvent is condensed, collected, and stored in a closed environment under oxygen-free and water-free conditions, and then used to prepare a tetrahydrofuran solution containing 25-35 wt% of p-hydroxyphenylhydrazine and a tetrahydrofuran solution containing 10-15 wt% of 2,4-dihydroxybenzophenone.

[0025] In the step (3), the solid phase obtained during evaporation is an antibacterial finishing agent solid material. The antibacterial finishing agent solid material is cooled, crushed, mixed, and sealed to obtain an antibacterial finishing agent.

[0026] The application method of the antibacterial finishing agent of the present invention comprises the following steps: adding the antibacterial finishing agent and sodium hydroxide into water to dissolve to obtain a finishing liquid, applying the finishing liquid to pure cotton fabric, heat-treating at 50-60°C for 2-3h to carry out a grafting reaction, then washing and dehydrating to obtain the finished pure cotton fabric; directly or after drying the finished pure cotton fabric, treating it with an aqueous solution containing 0.45-0.6wt% of hypochlorous acid for 1-3h to carry out an amine chlorination reaction, washing and drying to obtain the antibacterial pure cotton fabric; wherein the amount of the antibacterial finishing agent is 2-3% of the dry weight of the pure cotton fabric, the amount of the sodium hydroxide is 10-12% of the amount of the antibacterial finishing agent, and the units of the amount of the antibacterial finishing agent and the amount of sodium hydroxide added are g.

[0027] in:

[0028] The application amount of the finishing liquid is 80-300% of the dry weight of the pure cotton fabric, and the application amount unit is mL.

[0029] When the finishing liquid is applied to the pure cotton fabric, it is applied by spraying, spray rolling or dipping.

[0030] The aqueous solution containing 0.45-0.6 wt % of hypochlorous acid is prepared by adding hydrochloric acid or acetic acid to an aqueous solution of sodium hypochlorite or calcium hypochlorite.

[0031] The antibacterial pure cotton towel of the invention is prepared by the application method of the antibacterial finishing agent.

[0032] The main reaction equations in the preparation steps (1) and (2) of the antibacterial finishing agent of the present invention are as follows:

[0033]

[0034] The beneficial effects of the present invention are as follows:

[0035] The preparation process of the antibacterial finishing agent is relatively simple compared with the prior art, and the production cost is low; when used, conventional processes are used to finish cotton-containing fabrics, especially pure cotton fabrics. The antibacterial pure cotton fabrics prepared by using the antibacterial finishing agent, such as antibacterial pure cotton towels, can have a chlorine content of more than 0.2wt%, have good antibacterial properties and soft and wrinkle-resistant effects, and can be repeatedly chloraminated and maintain the antibacterial properties and soft and wrinkle-resistant effects for a long time; the antibacterial properties are less affected by ultraviolet radiation and strong sunlight exposure, and the antibacterial properties are not inconsistent with the solar light disinfection and sterilization method. Therefore, the present invention has certain application prospects.

[0036] From the effects of the following embodiments, comparative examples, and test examples, it is believed that the main principles of the antibacterial finishing agent of the present invention are as follows, and the above beneficial effects are also the result of the combined effects of the following principles and factors:

[0037] 1. The main and target reactions in steps (1) and (2) are that one of the chlorine groups in the methylphenyldichlorosilane molecule reacts with the 4-hydroxyl group of the benzene ring of p-hydroxyphenylhydantoin and 2,4-dihydroxybenzophenone, respectively, to form a strong connection between the Si-O-benzene ring. Under the reaction conditions, both reactions are easy to carry out, the molecular structures of the products are relatively simple, and the yield is over 97% (based on p-hydroxyphenylhydantoin and 2,4-dihydroxybenzophenone, respectively). The other chlorine group in the methylphenyldichlorosilane molecule does not react substantially because the chlorine group has low activity under the reaction conditions (step 1). After one chlorine group participates in the reaction, the reactivity of the second chlorine group decreases), the benzene ring in the product after the reaction has steric hindrance to the unreacted chlorine group, and the addition of methylphenyldichlorosilane is slow, the reaction is fast, and a small amount of volatilization is carried over but the excess is small; the 2-hydroxyl group on the other benzene ring in the 2,4-dihydroxybenzophenone molecule in step (2) does not react with methylphenyldichlorosilane because the carbonyl group and the 2-hydroxyl group form an internal hydrogen bond to form a chelate ring with a stable conjugated structure, which is also the physical basis for the hydroxybenzophenone group to continue to exert its ultraviolet absorption effect. Under the anhydrous conditions in steps (1) and (2), neither water is generated nor polymerization reaction between silanes occurs. Solution A, solution B and the antibacterial finishing agent obtained by mixing the two are also relatively stable under the condition of isolating air and moisture. The purpose of reacting the feed liquid under slightly boiling conditions is, firstly, to better control the reaction temperature, and secondly, to use the evaporated tetrahydrofuran vapor to remove the hydrogen chloride generated in the reaction so that the reaction proceeds normally.

[0038] 2. During the slight boiling reaction in steps (1) and (2), a small amount of methylphenyldichlorosilane is volatilized along with the gasification and escape of tetrahydrofuran solvent and hydrogen chloride and enters the condensate. After the addition of methylphenyldichlorosilane is completed, except for the reacted part, the rest continues to volatilize and enters the condensate. Therefore, the solution A and solution B obtained in steps (1) and (2) substantially do not contain methylphenyldichlorosilane, which is the condition for the stable storage of the antibacterial finishing agent obtained by mixing solution A and solution B in the above ratio in step (3).

[0039] 3. In the antimicrobial finishing agent of the present invention, the silicon (one silicon) in the silane molecule is connected to three groups: phenyl, methyl and phenoxy. These three groups are firmly and stably combined with the silicon as a whole (this is the reason why the reaction in steps (1) and (2) can be well realized), which has a significant improvement and promotion effect on improving the reaction activity between the second chlorine group in the silane molecule and the hydroxyl group on the surface of the cotton fabric (generating HCl). Under the alkaline aqueous solution finishing conditions, the problem of low activity and large steric hindrance of the second chlorine group in the silane molecule is overcome, and the carbon-oxygen bond formed by the grafting of the antimicrobial finishing agent molecule on the surface of the cotton fabric is relatively firm and stable. The grafting reaction is completed by generating hydrogen chloride. The grafting rate under the application conditions is very high, and the grafted product is relatively stable and is not easy to break or fall off during the chloramination, use, repeated washing and sun exposure of the cotton fabric. During the grafting reaction, sodium hydroxide plays a catalytic role and maintains the alkaline conditions required for the reaction.

[0040] 4. It is foreseeable that the antibacterial pure cotton fabrics such as antibacterial pure cotton towels prepared by using the antibacterial finishing agent of the present invention have good antibacterial properties; but it is unexpected that they have significant softness and wrinkle resistance effects. Hydrogen bonds are formed between the hydantoin group and the 2-hydroxybenzophenone group in the groups grafted on the surface of the cotton fiber. The effective ingredients of the antibacterial finishing agent of the present invention are all grafted on the surface of the cotton fiber in the form of small molecules (molecular weight less than 500) and single-bond connection, while the effective ingredients of conventional softness and wrinkle resistance agents are usually grafted on the surface of the cotton fiber in the form of long-chain macromolecules (molecular weight generally higher than 3000) and multi-bond connection, so the softness and wrinkle resistance effects are insufficient compared with the present invention.

[0041] 5. Among the raw materials used in the preparation of the antibacterial finishing agent of the present invention, methylphenyldichlorosilane is a common raw material in the field of organic silicon, which is widely used in the preparation of various silane coupling agents, silicone resins, silicone oils and other products; p-hydroxyphenylhydantoin (also known as 5-p-hydroxyphenylhydantoin) is a common raw material for producing the important intermediate L-p-hydroxyphenylglycine; 2,4-dihydroxybenzophenone is a UV absorber with a large amount and good performance; these three raw materials are of stable quality, easy to purchase, and relatively low price. The preparation and application process of the antibacterial finishing agent are also relatively simple, the utilization rate of raw materials is very high, and high-concentration organic wastewater is not generated. The post-treatment is relatively simple, so the comprehensive cost is not high and it is competitive. DETAILED DESCRIPTION

[0042] The present invention is specifically described and illustrated below in conjunction with embodiments.

[0043] Example 1

[0044] The antibacterial finishing agent of this embodiment is prepared by the following steps in a fume hood using methylphenyldichlorosilane, p-hydroxyphenylhydantoin and 2,4-dihydroxybenzophenone as synthetic reaction raw materials:

[0045] (1) A 500 mL glass reactor A (a three-necked flask fixed on an iron stand and an electromagnetic stirring heater) and its attached condenser A (the condensate A is discharged through a U-shaped liquid seal, and the non-condensable gas is fully absorbed and discharged through a bubbling absorption bottle filled with a sufficient and quantitative 0.1 mol / L sodium hydroxide aqueous solution and ten drops of phenolphthalein indicator solution. After the red color becomes lighter, 0.1 mol / L sodium hydroxide aqueous solution is quantitatively added) are subjected to anhydrous treatment and replaced with high-purity nitrogen (99.9%); 30 wt % p-hydroxyphenyl hydroxyethyl is injected into the reactor A. % tetrahydrofuran solution (preliminarily dehydrated with anhydrous sodium sulfate desiccant) 150g, install a thermometer, put in a stirrer and start stirring and heating, the solution is heated to a slight boil and 147g of a tetrahydrofuran solution containing 35wt% methylphenyldichlorosilane is continuously injected under a slight boiling condition (steam temperature is about 66°C) and the injection time is controlled to be 5.3h, after which the solution continues to react for 45min under a slight boiling condition, the temperature is naturally lowered and an appropriate amount of high-purity nitrogen is charged for protection, the solution is transferred into a nitrogen-substituted sealable container to obtain 290g of solution A and sealed and stored under anaerobic and anhydrous conditions for standby use; wherein the molar ratio of p-hydroxyphenylhydantoin to methylphenyldichlorosilane is 1:1.15;

[0046] (2) A 500 mL glass reactor B (a three-necked flask fixed on an iron stand and an electromagnetic stirring heater) and its attached condenser B (the condensate B is discharged through a U-shaped liquid seal, and the non-condensable gas flows through a bubbling absorption bottle filled with a sufficient amount of a quantitative standard 0.05 mol / L sodium hydroxide aqueous solution and ten drops of phenolphthalein solution to be fully absorbed and discharged. After the red color becomes lighter, 0.1 mol / L sodium hydroxide aqueous solution is quantitatively added) are subjected to anhydrous treatment and replaced with high-purity nitrogen; a solution containing 12.5 wt% 2,4-dihydroxybenzophenone is injected into the reactor B. % tetrahydrofuran solution (preliminarily dehydrated with anhydrous calcium chloride desiccant) 160g, install a thermometer, put in a stirrer and start stirring and heating, the solution is heated to a slight boil and 58.7g of a tetrahydrofuran solution containing 35wt% methylphenyldichlorosilane is continuously injected under a slight boiling condition (steam temperature is about 66°C) and the injection time is controlled to be 5.5h, after which the solution continues to react for 45min under a slight boiling condition, the temperature is naturally lowered and an appropriate amount of high-purity nitrogen is charged for protection, the solution is transferred into a nitrogen-substituted sealable container to obtain 215g of solution B and sealed and stored under anaerobic and anhydrous conditions for standby use; wherein the molar ratio of 2,4-dihydroxybenzophenone to methylphenyldichlorosilane is 1:1.1;

[0047] (3) Take 50 g of solution A and 5.0 g of solution B, respectively, and transfer them into a 200 mL single-necked flask (fixed on an iron stand and an electromagnetic stirring heater) replaced with high-purity nitrogen. Add a stirrer and start stirring and heating. The solution is heated to a slight boiling point and continuously distilled to dryness under the slight boiling condition (the material temperature is measured by an infrared thermometer and the heating load is controlled to control the solution not to exceed 80° C.). The solution is cooled naturally and an appropriate amount of high-purity nitrogen is charged for protection to obtain an antibacterial finishing agent, which is then stoppered and stored for later use.

[0048] In steps (1) and (2), the condensation temperature of the condensers A and B is controlled to be 25°C; during the slight boiling reaction in the reactors A and B, tetrahydrofuran is continuously injected to maintain the volume and concentration of the solution in the reactors A and B unchanged; the reactors A and B continuously discharge tetrahydrofuran vapor containing hydrogen chloride, which is condensed in the condensers A and B and then collected to obtain condensate A and condensate B, which are stored in a sealed manner under anaerobic and anhydrous conditions; the total weight of the collected condensates A and B is 226 g.

[0049] In steps (1) and (2), the pH values ​​of the condensates A and B (discharged through the U-shaped liquid seal) are regularly detected using precision pH test paper to track and judge the reaction progress of the feed liquid in the reactors A and B respectively; during the injection of the tetrahydrofuran solution of methylphenyldichlorosilane, the pH values ​​of the condensates A and B are both lower than 3; and 15-20 minutes after the injection of the tetrahydrofuran solution of methylphenyldichlorosilane is completed, the condensates are no longer acidic (i.e., no hydrogen chloride is generated and the reaction is completed).

[0050] The residual sodium hydroxide concentration in the sodium hydroxide aqueous solution in the two bubbling absorption bottles is measured by sampling, and the corresponding hydrogen chloride absorption amount is calculated; the condensate A and B are sampled to determine the hydrogen chloride content and the total chlorine content; and according to the volume, weight and the absorption amount and content of the four solutions, combined with the feed amount of p-hydroxyphenyl hydantoin, 2,4-dihydroxybenzophenone and methylphenyl dichlorosilane, it can be judged that: in the reaction of steps (1) and (2), one methylphenyl dichlorosilane has only reacted with one p-hydroxyphenyl hydantoin molecule or one 2,4-dihydroxybenzophenone molecule to release hydrogen chloride, and the p-hydroxyphenyl hydantoin, 2,4-dihydroxybenzophenone and methylphenyl dichlorosilane in solutions A and B have all been reacted and converted. The hydrogen chloride content of the condensate A and B is measured by acid-base titration with a tetrahydrofuran standard solution of triethylamine; the total chlorine content is determined by silver nitrate titration. The total chlorine content determination process is to take a sample from the condensate A or condensate B, first quantitatively add 0.5 mol / L sodium hydroxide aqueous solution and phenolphthalein indicator solution, boil for 1 hour, then add enough 20wt% nitric acid aqueous solution and continue to boil for 1 hour, close the container and keep it at 90-95°C for 2 hours, filter it, add a little potassium chromate as an indicator, and then titrate with 0.1 mol / L silver nitrate standard solution. The phenolphthalein indicator solution is a tetrahydrofuran solution containing 0.1% phenolphthalein.

[0051] Example 2

[0052] The antibacterial finishing agent of Example 2 was prepared by operating substantially according to steps (1) to (3) of Example 1, except that the injection rate of the tetrahydrofuran solution containing 35 wt% of methylphenyldichlorosilane in steps (1) and (2) of Example 1 was reduced to 7.4 h and 7.9 h, respectively, and the molar ratio of the two feeds was changed to 1:1.2.

[0053] Results In steps (1) and (2), during the reaction process of continuously injecting a tetrahydrofuran solution containing 35 wt% of methylphenyldichlorosilane under slightly boiling conditions, the pH values ​​of the condensates A and B were both lower than 3 when regularly detected by precise pH test paper. The condensates were no longer acidic within 20 minutes after the injection of the tetrahydrofuran solution of methylphenyldichlorosilane.

[0054] The other tests in Example 1 were carried out; based on the test results, the same conclusion can be drawn: in the reactions of steps (1) and (2), one methylphenyldichlorosilane reacted with only one p-hydroxyphenylhydantoin molecule or one 2,4-dihydroxybenzophenone molecule to release hydrogen chloride, and all p-hydroxyphenylhydantoin, 2,4-dihydroxybenzophenone and methylphenyldichlorosilane in solution A and solution B were completely reacted and converted.

[0055] Example 3

[0056] The antibacterial finishing agent of this embodiment was prepared by operating substantially according to steps (1) to (3) of Example 1; except that the injection rate of the tetrahydrofuran solution containing 35 wt % of methylphenyldichlorosilane in steps (1) and (2) of Example 1 was increased to 5 h and 5 h, respectively, and the molar ratio of p-hydroxyphenylhydantoin to methylphenyldichlorosilane was 1:1.1; and the molar ratio of 2,4-dihydroxybenzophenone to methylphenyldichlorosilane was 1:1.15.

[0057] Example 4

[0058] The antibacterial finishing agent of this embodiment is prepared by basically following the steps (1) to (3) of Example 1; the difference is that in step (1), a tetrahydrofuran solution containing 25 wt% of p-hydroxyphenyl hydroxylamine and a tetrahydrofuran solution containing 30 wt% of methylphenyl dichlorosilane are used instead; the solution is continued to react for 0.5 h under a slightly boiling condition, and the temperature is lowered to obtain solution A; in step (2), a tetrahydrofuran solution containing 15% of 2,4-dihydroxybenzophenone and a tetrahydrofuran solution containing 40 wt% of methylphenyl dichlorosilane are used instead; the solution is continued to react for 1 h under a slightly boiling condition, and the temperature is lowered to obtain solution B. In steps (1) and (2), the condensation temperature of the condensers A and B is controlled to be 20°C.

[0059] Example 5

[0060] The antibacterial finishing agent of this embodiment is prepared by basically following the steps (1) to (3) of Example 1; the difference is that in step (1), a tetrahydrofuran solution containing 35 wt% of p-hydroxyphenyl hydroxylamine and a tetrahydrofuran solution containing 40 wt% of methylphenyl dichlorosilane are used instead; the solution is continued to react for 1 hour under a slightly boiling condition, and the temperature is lowered to obtain solution A; in step (2), a tetrahydrofuran solution containing 10% of 2,4-dihydroxybenzophenone and a tetrahydrofuran solution containing 30 wt% of methylphenyl dichlorosilane are used instead; the solution is continued to react for 0.5 hour under a slightly boiling condition, and the temperature is lowered to obtain solution B. In steps (1) and (2), the condensation temperature of the condensers A and B is controlled to be 10°C.

[0061] Example 6

[0062] Take 50 g and 4.0 g of solution A obtained in step (1) of Example 1 and solution B obtained in step (2), respectively, and operate according to step (3) of Example 1, mix, evaporate to dryness, and seal with a stopper to obtain the antibacterial finishing agent of this example.

[0063] Example 7

[0064] Take 50 g and 6.0 g of solution A obtained in step (1) of Example 1 and solution B obtained in step (2), respectively, and operate according to step (3) of Example 1, mix, evaporate to dryness, and seal with a stopper to obtain the antibacterial finishing agent of this example.

[0065] Comparative Example 1

[0066] An appropriate amount of the solution A obtained in step (1) of Example 1 is taken as the antibacterial finishing agent of this comparative example 1.

[0067] Comparative Example 2

[0068] The antibacterial finishing agent of Comparative Example 2 was prepared by substantially following steps (1) to (3) of Example 1, except that the tetrahydrofuran solution containing 35 wt % of methylphenyldichlorosilane used in steps (1) and (2) of Example 1 was replaced by a tetrahydrofuran solution containing 35 wt % of diphenyldichlorosilane.

[0069] Results In steps (1) and (2), during the reaction process of continuously injecting a tetrahydrofuran solution containing 35 wt% diphenyldichlorosilane under slightly boiling conditions, the pH values ​​of the condensates A and B were both lower than 3 when measured regularly with precision pH test paper; and the condensates were no longer acidic 20 minutes after the injection of the tetrahydrofuran solution containing 35 wt% diphenyldichlorosilane, indicating that both p-hydroxyphenylhydantoin and 2,4-dihydroxybenzophenone could react stably with diphenyldichlorosilane and the reaction was complete.

[0070] Comparative Example 3

[0071] The antibacterial finishing agent of Comparative Example 3 was prepared by substantially following steps (1) to (3) of Example 1, except that the tetrahydrofuran solution containing 35 wt % of methylphenyldichlorosilane used in steps (1) and (2) of Example 1 was replaced by a tetrahydrofuran solution containing 35 wt % of dimethyldichlorosilane.

[0072] Results In steps (1) and (2), during the reaction process of continuously injecting a tetrahydrofuran solution containing 35 wt% of dimethyldichlorosilane under slightly boiling conditions, the pH values ​​of the condensates A and B were both lower than 3 when measured regularly with precision pH test paper; the condensates were no longer acidic 35 minutes after the injection of the tetrahydrofuran solution containing 35 wt% of dimethyldichlorosilane, indicating that both p-hydroxyphenylhydantoin and 2,4-dihydroxybenzophenone could react stably with dimethyldichlorosilane and the reaction was complete.

[0073] Comparative Example 4

[0074] The antibacterial finishing agent of Comparative Example 4 was prepared by substantially following steps (1) to (3) of Example 1, except that the tetrahydrofuran solution containing 35 wt % of methylphenyldichlorosilane used in steps (1) and (2) of Example 1 was replaced by a tetrahydrofuran solution containing 35 wt % of cyanuric chloride.

[0075] Results In steps (1) and (2), during the reaction process of continuously injecting a tetrahydrofuran solution containing 35 wt% of cyanuric chloride under slightly boiling conditions, the pH values ​​of the condensates A and B were both lower than 3 when measured regularly with precision pH test paper. The condensates were no longer acidic 17 minutes after the injection of the tetrahydrofuran solution containing 35 wt% of cyanuric chloride, indicating that both p-hydroxyphenylhydrazine and 2,4-dihydroxybenzophenone could react stably with cyanuric chloride and the reaction was complete.

[0076] The reactions in steps (1) and (2) of this comparative example 4 are respectively the 4-position phenylhydroxyl groups of the phenylhydroxyl groups of p-hydroxyphenyl hydantoin and 2,4-dihydroxybenzophenone and one chlorine of cyanuric chloride to produce a synthesis reaction to release hydrogen chloride, and the reaction conditions are similar to those of the reaction with dimethyldichlorosilane.

[0077] Example 8

[0078] Fully bleached, natural color cotton plain fabric (172g / m 2 ), as the antibacterial treated fabric of this embodiment. 88 rectangular pieces of cloth with a single weight of 2.0g were cut from the pure cotton plain weave cloth, and plastic number tags were added to each piece. After drying in an oven at 100°C for 2 hours, they were moved into a glass dryer (with sufficient blue silica gel placed at the bottom) while hot and cooled to obtain a pure cotton plain weave cloth test piece; the test piece was folded in half, divided into transparent sample bags of polyethylene material of equivalent size, and sealed for standby use, with one test piece in each bag. The antibacterial finishing agents of Examples 1-7 and Comparative Examples 1-4 were each tested for application and effect using 8 test pieces (88 pieces in total) of the test pieces.

[0079] Each antibacterial finishing agent was applied as follows: 1.0 g of the antibacterial finishing agent powder was accurately weighed and placed in a 50 mL clean test tube with a ground stopper, which was preheated in a 60°C oven for more than 20 min, and 32 mL of a 60°C, 0.32 wt% sodium hydroxide aqueous solution (prepared with pure water) was injected, and then returned to the 60°C oven to dissolve for 10 min (shaken every 2 min). All the powders in each case were dissolved to obtain a finishing liquid, which was applied to the test piece through a 2 mL transparent plastic syringe within 10 min. The injection volume of each bag of test piece was 1.6 mL. The liquid was sprayed roughly and evenly onto the folded test piece through a stainless steel fine needle, and most of the air in the sample bag was driven out and then sealed. The sample bag was squeezed to make the finishing liquid evenly distributed in the test piece, and the sample bag was placed horizontally in a 50°C oven for 2 h for grafting reaction (the amount of antibacterial finishing agent was 2.0% of the weight of the test piece, and the amount of sodium hydroxide was 1.6%. The dosage is 10% of the antibacterial finishing agent, and the application amount of the finishing liquid is 80% of the weight of the test piece); then, each test piece is taken out, and 8 pieces corresponding to each antibacterial finishing agent are grouped together, centrifuged and dried, fully washed with tap water, and centrifuged and dried; the centrifuged and dried test pieces are still grouped together with 7 pieces (1 piece is reserved for testing) of the 8 pieces (test pieces after finishing) corresponding to each antibacterial finishing agent, and each is placed in a transparent sample bag made of polyethylene material, and 20 mL of a room temperature aqueous solution containing 0.60 wt% of hypochlorous acid (chlorinated liquid, prepared by adding tap water and dilute hydrochloric acid to a commercially available sodium hypochlorite solution 84 disinfectant) is injected through a 50 mL transparent plastic syringe, and the sample bag is squeezed to make the chlorinated liquid evenly distributed in the test piece, and the test piece is placed horizontally for 1.5 hours for amine chlorination reaction. The test piece is taken out, centrifuged and dried, fully washed with tap water, centrifuged and dried, and then air-dried to obtain an antibacterial pure cotton plain fabric test piece (7 pieces).

[0080] Example 9

[0081] Fully bleached, natural color cotton terry cloth (246g / m 2 ), as the antibacterial treated fabric of this embodiment. 56 square pieces of cloth with a single weight of 2.0g were cut from the pure cotton terry cloth, and plastic number tags were attached to each piece. After drying in an oven at 100°C for 2h, they were moved into a glass dryer (with sufficient blue silica gel placed at the bottom) while hot and cooled to obtain pure cotton terry cloth test pieces; the test pieces were divided into transparent sample bags of polyethylene material of equivalent size, sealed for standby use, and each bag contained one test piece. The antibacterial finishing agents of Examples 1-7 were used with 8 test pieces for application and effect testing.

[0082] Each antibacterial finishing agent was applied as follows: 1.0 g of the antibacterial finishing agent powder was accurately weighed and placed in a 100 mL clean test tube with a ground stopper, and 64 mL of a 60°C, 0.19 wt% sodium hydroxide aqueous solution was injected, and the tube was placed in a 60°C oven for heating and dissolving for 10 min (shaken every 2 min). All the powders were dissolved to obtain a finishing liquid, and applied to the test piece through a 2 mL transparent plastic syringe within 10 min. The injection volume of each bag of test piece was 3.2 mL. The liquid was sprayed onto the test piece roughly evenly through a stainless steel fine needle, and most of the air in the sample bag was driven out and then sealed. The sample bag was squeezed to make the finishing liquid evenly distributed in the test piece, and the sample bag was placed horizontally in a 60°C oven for 2.5 h for grafting reaction (the amount of antibacterial finishing agent was 2.5% of the weight of the test piece, the amount of sodium hydroxide was 12% of the weight of the antibacterial finishing agent, and the whole bag was placed horizontally in a 60°C oven for 2.5 h for grafting reaction (the amount of antibacterial finishing agent was 2.5% of the weight of the test piece, the amount of sodium hydroxide was 12% of the weight of the antibacterial finishing agent, and the amount of sodium hydroxide was 12% of the weight of the whole bag). The amount of the treatment liquid applied is about 160% of the weight of the test piece); then, each test piece is taken out, and 8 pieces corresponding to each antibacterial finishing agent are grouped together, centrifuged and dried, fully washed with tap water, and centrifuged and dried; the centrifuged and dried test pieces are still grouped together with 7 pieces (1 piece is reserved for testing) out of the 8 pieces (test pieces after finishing) corresponding to each antibacterial finishing agent, and each is placed in a transparent sample bag made of polyethylene, and 30 mL of a room temperature aqueous solution containing 0.51 wt% hypochlorous acid (chlorinated liquid, prepared by adding tap water and white vinegar to a commercially available sodium hypochlorite solution 84 disinfectant) is injected through a 50 mL transparent plastic syringe, the sample bag is squeezed to evenly distribute the chlorinated liquid in the test piece, and the test piece is placed horizontally for 3 hours to perform amine chlorination reaction, and the test piece is taken out, centrifuged and dried, fully washed with tap water, centrifuged and dried, and then dried in an oven at 80°C for 1 hour to obtain an antibacterial pure cotton towel cloth test piece.

[0083] Example 10

[0084] Fully bleached, natural color cotton terry cloth (198g / m 2 ), as the antibacterial treated fabric of this embodiment. 56 square pieces of cloth with a single weight of 2.0g were cut from the pure cotton terry cloth, and plastic number tags were attached to each piece. After drying in an oven at 100°C for 2h, they were moved into a glass dryer (with sufficient blue silica gel placed at the bottom) while hot and cooled to obtain pure cotton terry cloth test pieces; the test pieces were divided into transparent sample bags of polyethylene material of equivalent size, sealed for standby use, and each bag contained one test piece. The antibacterial finishing agents of Examples 1-7 were used with 8 test pieces for application and effect testing.

[0085] Each antibacterial finishing agent was applied as follows: 1.8 g of the antibacterial finishing agent powder was accurately weighed and placed in a 100 mL clean test tube with a ground stopper, 120 mL of a 60°C, 0.165 wt% sodium hydroxide aqueous solution was injected, and the tube was placed in a 60°C oven for heating and dissolving for 10 min (shaken every 2 min). All the powders were dissolved to obtain a finishing liquid, which was applied to the test piece through a 2 mL transparent plastic syringe within 10 min. The injection volume of each bag of test piece was 6 mL. The liquid was sprayed onto the test piece roughly evenly through a stainless steel fine needle, and most of the air in the sample bag was driven out and then sealed. The sample bag was squeezed to make the finishing liquid evenly distributed in the test piece. The sample bag was placed horizontally in a 60°C oven for 2.5 h for grafting reaction (the amount of antibacterial finishing agent was 3% of the weight of the test piece, the amount of sodium hydroxide was 11% of the weight of the antibacterial finishing agent, and the amount of finishing liquid applied was about 300% of the weight of the test piece); then each test piece was taken out and the corresponding amount of each antibacterial finishing agent was 0.5 mL. The 8 pieces were grouped as a group, centrifuged and dried, washed thoroughly with tap water, and centrifuged and dried; the centrifuged and dried test pieces were still grouped with 7 pieces (1 piece was kept for testing) of the 8 pieces (test pieces after finishing) corresponding to each antibacterial finishing agent as a group, each of which was packed in a transparent sample bag made of polyethylene, and 30 mL of a room temperature aqueous solution containing 0.45 wt% of hypochlorous acid (chlorinated liquid, prepared by adding tap water and white vinegar to a commercially available sodium hypochlorite solution 84 disinfectant) was injected through a 50 mL transparent plastic syringe, the sample bag was squeezed to make the chlorinated liquid evenly distributed in the test piece, and the test piece was placed horizontally for 1 hour for amine chlorination reaction. The test piece was taken out, centrifuged and dried, washed thoroughly with tap water, centrifuged and dried, and then dried in an oven at 80°C for 1 hour to obtain an antibacterial pure cotton towel cloth test piece.

[0086] The test pieces prepared by applying the antibacterial finishing agents of Examples 1-7 in the above examples have almost no odor and are softer and wrinkle-resistant than the pure cotton fabric test pieces before finishing; the antibacterial pure cotton fabric test pieces obtained have no odor at all, and the softness and wrinkle-resistant effect are equivalent to those of the test pieces after finishing.

[0087] Test Example 1

[0088] The antibacterial pure cotton fabric test pieces obtained in Examples 8-10 and using the antibacterial finishing agents of Examples 1-7 were subjected to the following tests: active chlorine content (sodium thiosulfate / iodine method); breaking strength (GB / T3923.1-2013); active chlorine ultraviolet stability (GB / T18830-2009, wavelength 290-400 nm, power 0.80 W / m 2 , temperature 60℃, irradiation time 24 h) and resistance to strong sunlight exposure; active chlorine water washing stability (washing method according to GB / T12490-2014, using B1M program and standard detergent WOB).

[0089] The antibacterial pure cotton fabric test pieces using the antibacterial finishing agents of Comparative Examples 1-4 were subjected to one or more of the above tests as required.

[0090] The active chlorine content of the test pieces after finishing with the antibacterial finishing agent of Examples 1-7 was also measured as a control.

[0091] The main test results include: the active chlorine content of the antibacterial pure cotton cloth test pieces using the antibacterial finishing agent of Examples 1-7 is higher than 0.24wt%; the active chlorine retention rate after the active chlorine ultraviolet stability test is higher than 78%, and the active chlorine retention rate after exposure to room temperature and strong sunlight for 8 hours is higher than 96%, indicating that the antibacterial performance is less affected by ultraviolet radiation; compared with the pure cotton cloth test pieces before finishing, the strong retention rate of the antibacterial pure cotton cloth test pieces is higher than 80%; the active chlorine retention rate after 25 simulated water washings is higher than 50% (that is, the active chlorine content is higher than 0.12wt%), and still has good antibacterial performance. The antibacterial pure cotton cloth test piece after the active chlorine ultraviolet stability test and the antibacterial pure cotton cloth test piece after simulated water washing 25 times were subjected to secondary chloramination treatment (each test piece was respectively placed in a transparent sample bag made of polyethylene material, and 3 mL of a room temperature aqueous solution containing 0.51 wt% hypochlorous acid used in Example 9 was injected through a 5 mL transparent plastic syringe, and the sample bag was squeezed to make the chlorinated liquid evenly distributed in the test piece, and the test piece was placed horizontally for 1.5 hours for amine chlorination reaction. The test piece was taken out, washed thoroughly with tap water, centrifuged and dried, and then dried in an oven at 80°C for 1 hour until dry), and the active chlorine content was detected to be still higher than 0.24 wt%, and the strength retention rate compared with the pure cotton cloth test piece before finishing was more than 76%, and the soft and wrinkle-resistant effect was still comparable to that of the test piece after finishing, indicating that repeated amine chlorination reaction had little effect on the performance of the antibacterial pure cotton cloth test piece.

[0092] The antibacterial pure cotton fabric test piece using the antibacterial finishing agent of comparative example 1 (not containing the ultraviolet light absorbing component 2-hydroxybenzophenone group of step (2)) also has an active chlorine content higher than 0.24wt%; the active chlorine retention rate after the active chlorine ultraviolet stability test is lower than 45%, and the active chlorine retention rate after exposure to normal temperature and strong sunlight for 8 hours is lower than 83%, indicating that the antibacterial performance is greatly affected by ultraviolet radiation.

[0093] The antibacterial pure cotton cloth test pieces using the antibacterial finishing agents of Comparative Examples 2 and 3 have active chlorine contents of 0.10wt% and 0.11wt%, respectively; the active chlorine contents after the active chlorine ultraviolet stability test are both lower than 0.06wt%, and the active chlorine contents after exposure to sunlight for 8 hours at room temperature and strong sunlight are both lower than 0.09wt%, indicating that the grafting reaction rate of the dehydrochlorination reaction products of p-hydroxyphenyl hydantoin and 2,4-dihydroxybenzophenone with diphenyldichlorosilane or dimethyldichlorosilane and the cotton fiber surface is lower than half of that in Example 1 using methylphenyldichlorosilane, and the effect is poor.

[0094] The antibacterial pure cotton cloth test piece using the antibacterial finishing agent of Comparative Example 4 has an active chlorine content of 0.26wt%; the active chlorine retention rate after the active chlorine ultraviolet stability test is 42%, and the active chlorine retention rate after exposure to sunlight for 8 hours at room temperature and strong sunlight is 84%, indicating that the dehydrochlorination reaction product of 2,4-dihydroxybenzophenone and cyanuric chloride has a poor anti-ultraviolet effect after grafting on the cotton fiber surface (the grafting amount on the cotton fiber surface should not be low), which is significantly lower than the effect when methylphenyldichlorosilane is used in Example 1.

[0095] According to the method of Examples 8-10, the antibacterial cotton plain fabric test piece and the antibacterial cotton terry cloth test piece using the antibacterial finishing agent of Example 1 were repeatedly prepared, and the antibacterial performance test was respectively carried out, and the test method was GB / T20944.2-2008, using Escherichia coli ATCC25922 and Staphylococcus aureus ATCC25923 (purchased from the Clinical Laboratory Center of the National Health Commission). The results showed that both test pieces had good antibacterial performance, and the killing logarithm value of the two bacteria (inoculation concentration was (1.0-1.1)×107CFU / sample) at 10 minutes was more than 6.8.

[0096] Although the present invention is described in detail by way of embodiments, the present invention is not limited thereto. Without departing from the spirit and substance of the present invention, those skilled in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions should all be within the scope of the present invention.

Claims

1. An antibacterial finishing agent, characterized in that: Methylphenyldichlorosilane, p-hydroxyphenylhydantoin and 2,4-dihydroxybenzophenone are used as the raw materials for the synthesis reaction and are prepared by the following steps: (1) subjecting a stirred reactor A and its attached condenser A to dehydration and nitrogen replacement; injecting a tetrahydrofuran solution containing 25-35 wt% of p-hydroxyphenyl hydantoin into the reactor A, stirring continuously, heating the solution to a slight boiling temperature, and continuously injecting a tetrahydrofuran solution containing 30-40 wt% of methylphenyl dichlorosilane under the slight boiling condition, and controlling the injection time to be 5-7.5 h, and then continuing the reaction of the solution under the slight boiling condition for 0.5-1 h, cooling, and obtaining a solution A; wherein the molar ratio of p-hydroxyphenyl hydantoin to methylphenyl dichlorosilane is 1:(1.1-1.2); (2) The stirred reactor B and its attached condenser B are subjected to anhydrous treatment and nitrogen replacement; a tetrahydrofuran solution containing 10-15 wt% of 2,4-dihydroxybenzophenone is injected into the reactor B, and stirring is continued. The solution is heated to a slight boiling temperature, and a tetrahydrofuran solution containing 30-40 wt% of methylphenyldichlorosilane is continuously injected under the slight boiling condition, and the injection time is controlled to be 5-8 hours. Thereafter, the solution is continued to react for 0.5-1 hour under the slight boiling condition, and the temperature is lowered to obtain a solution B; wherein the molar ratio of 2,4-dihydroxybenzophenone to methylphenyldichlorosilane is 1:(1.1-1.2); (3) mixing solution A and solution B at a weight ratio of 100:(8-12) and evaporating the mixture to remove the tetrahydrofuran solvent and obtain an antibacterial finishing agent; In steps (1)-(2), the condensation temperature of the condensers A and B is controlled at 10-25°C; during the slight boiling reaction of the solutions in reactors A and B, tetrahydrofuran is intermittently or continuously injected to maintain the volume and concentration of the solutions in reactors A and B unchanged; tetrahydrofuran vapor containing hydrogen chloride is continuously discharged from reactors A and B, which is condensed in condensers A and B respectively and then collected to obtain condensate A and condensate B, which are then sealed and stored in anoxic and anhydrous conditions respectively.

2. The antibacterial finishing agent according to claim 1, characterized in that The tetrahydrofuran solution containing 25-35 wt% of p-hydroxyphenylhydrazine in step (1) and the tetrahydrofuran solution containing 10-15 wt% of 2,4-dihydroxybenzophenone in step (2) are both pre-dehydrated with anhydrous calcium chloride or anhydrous sodium sulfate.

3. The antibacterial finishing agent according to claim 1, characterized in that In steps (1)-(2), the tetrahydrofuran vapor containing hydrogen chloride is condensed and collected by condensers A and B, respectively, and stored in a closed manner under oxygen-free and water-free conditions. After that, the hydrogen chloride is removed by distillation to obtain a tetrahydrofuran solution containing methylphenyldichlorosilane, which is used to prepare a tetrahydrofuran solution containing 30-40wt% of methylphenyldichlorosilane.

4. The antibacterial finishing agent according to claim 1, characterized in that In step (3), the tetrahydrofuran solvent is condensed, collected, and stored in a sealed manner under oxygen-free and water-free conditions, and then used to prepare a tetrahydrofuran solution containing 25-35wt% of p-hydroxyphenylhydrazine and a tetrahydrofuran solution containing 10-15wt% of 2,4-dihydroxybenzophenone.

5. The antibacterial finishing agent according to claim 1, characterized in that In step (3), the solid phase obtained during evaporation is an antibacterial finishing agent solid material. The antibacterial finishing agent solid material is cooled, crushed, mixed, and sealed to obtain an antibacterial finishing agent.

6. A method for applying the antibacterial finishing agent according to any one of claims 1 to 5, characterized in that: The following steps are involved: An antibacterial finishing agent and sodium hydroxide are added into water to dissolve to obtain a finishing solution, the finishing solution is applied to pure cotton fabric, and the fabric is heat-treated at 50-60°C for 2-3 hours for grafting reaction, followed by washing and dehydration to obtain the finished pure cotton fabric; at room temperature, the finished pure cotton fabric is directly or after being dried, treated with an aqueous solution containing 0.45-0.6wt% of hypochlorous acid for 1-3 hours for amine chlorination reaction, washed and dried to obtain the antibacterial pure cotton fabric; wherein the amount of the antibacterial finishing agent is 2-3% of the dry weight of the pure cotton fabric, the amount of sodium hydroxide added is 10-12% of the amount of the antibacterial finishing agent, and the units of the amount of the antibacterial finishing agent and the amount of sodium hydroxide added are g.

7. The application method according to claim 6, characterized in that: The application amount of the finishing liquid is 80-300% of the dry weight of the pure cotton fabric, and the application amount unit is mL.

8. The application method according to claim 6, characterized in that: When the finishing solution is applied to pure cotton fabrics, it is applied by spraying, spray padding or padding.

9. The application method according to claim 6, characterized in that: The aqueous solution containing 0.45-0.6 wt% of hypochlorous acid is prepared by adding hydrochloric acid or acetic acid to an aqueous solution of sodium hypochlorite or calcium hypochlorite.

10. An antibacterial pure cotton towel, characterized in that: Prepared by any application method of claims 6-9.

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