CN1310589C - Method for preparing superfine composite inorganic antimicrobial agent - Google Patents

Abstract

The present invention discloses a method for preparing superfine composite inorganic antimicrobial agents, which comprises the following technical steps: using silver ions as precipitating crystal nuclei, and using urea as a precipitating agent for precipitating titanium ions and other metallic ions and coating the precipitating crystal nuclei; then, adding phosphate to form secondary layer coatings and successively adding a compounded surface modifying agent; dewatering and drying the composition, calcining the dried composition at the temperature between 700 DEG C and 1100 DEG C for 2 to 10h to obtain superfine grade antimicrobial powder. The antimicrobial powder prepared by the method of the present invention has stronger effect on killing bacteria and fungi, and overcomes the defects that the antimicrobial agents of silver series have no excellent effect on killing fungi and easily change color, the antimicrobial agents of titanium series need illumination to perform the efficiency of sterilization, etc. An inorganic antibacterial agent prepared by the present invention can be widely applied to the fields of processing textiles, plastics, coatings, paint, enamel, ceramics, etc., and the field of treating water, etc.

Description

A kind of preparation method of superfine composite inorganic antibacterial agent

technical field

The invention relates to a preparation method of an inorganic antibacterial agent, belonging to the technical field of inorganic antibacterial agent preparation.

Background technique

Human anti-disease health care is inseparable from antibacterial agents, which can be divided into organic antibacterial agents and inorganic antibacterial agents according to their components. Organic antibacterial agents are traditional antibacterial agents, which have been widely used at present, but they generally have defects such as volatile, easy to decompose, poor heat resistance, and bacteria are prone to drug resistance.

Due to the advantages of non-volatility, good heat resistance, low drug resistance and high safety, inorganic antibacterial agents have become one of the hot spots in the development of antibacterial agents. Inorganic antibacterial agents are generally solid powders, which are mainly used in the form of additives to prepare various antibacterial functional products by combining with the main material of the application.

Among the inorganic antibacterial ingredients, because silver ions have strong broad-spectrum antibacterial properties, the preparation method of combining silver ions with inorganic carriers has become an important direction of current research on inorganic antibacterial agents. However, there are also some problems with silver-based antibacterial agents. The silver ions in this type of material tend to turn gray or brown after being irradiated by sunlight or heated to a certain temperature, which affects the color of the product; in addition, its antifungal effect is relatively poor. These have all hindered the application of silver-based antimicrobials to a certain extent. Ultrafine TiO ₂ has strong ultraviolet absorption and shielding ability, high surface catalytic activity and broad-spectrum bactericidal function, etc. Among them, the bactericidal function has attracted people's attention, and it has antibacterial and antifungal effects at the same time. However, ultrafine TiO ₂ must be sterilized by light (mainly ultraviolet light), which limits its application range.

Experiments show that: as the particle size of the antibacterial agent decreases, the antibacterial rate gradually increases. This is because the particle size decreases and the number of antibacterial powder particles per unit weight increases, thereby increasing the contact area with bacteria and improving the antibacterial effect. Therefore, when using the antibacterial rate as an indicator, in addition to focusing on the influence of the material ratio on it, the particle size is also a factor that must be considered in the preparation process of inorganic antibacterial agents.

Most of the inorganic antibacterial agents currently on the market use silver ions as the main antibacterial component. Natural or artificial raw materials such as silicate, zeolite, etc. are used as carriers to prepare them through adsorption, ion exchange and other processes. Parts in the carrier are unstable, easy to change color and other shortcomings, which cannot well meet the requirements of practical applications.

Contents of the invention

The object of the present invention is to provide a preparation method of a multi-component composite inorganic antibacterial agent with ultra-fine grade, stable physical properties and strong broad-spectrum bactericidal effect.

In order to achieve the above-mentioned purpose, the present invention uses silver ion precipitates as sedimentation crystal nuclei, externally wraps metal compounds such as titanium, and phosphate precipitates as the second layer of wrapping. After solid-liquid separation, heat treatment can obtain composite antibacterial powder. The diameter is uniform and ultra-fine.

A kind of preparation method of superfine composite inorganic antibacterial agent, its preparation process comprises the following steps successively:

a. Add AgNO ₃ solution to the mixed solution of titanium liquid and chloride with a pH value of 1-3, and stir for 0.5-1h;

b. Then add urea and react at 50-130°C for 1-4 hours;

c. Add soluble phosphate dropwise and react for 0.5-1 hour;

d. Add the compounded surface modifier and react for 0.3~1h;

e. Solid-liquid separation, dehydration and drying, and calcining at 700-1100°C for 2-10 hours to obtain the product;

The material molar ratio of the above preparation method is Ti ⁴⁺ : Ag ⁺ : PO ₄ ^3- = 5-15: 0.5-1: 2-10; Ag ^{+ : Cl-} = 1: 1.2-10; Ti ^{4+ :} CO( NH ₂ ) ₂ =1:2~8.

The aforementioned titanium solution refers to a solution of soluble titanium salt, such as an aqueous solution of Ti(SO ₄ ) ₂ , TiOSO ₄ , TiCl ₄ , etc.

Chloride refers to MCl, M=Na, K, H or NH ₄ ;

or MCl ₂ , M=Zn, Sn or Cu;

Or MCl ₄ , M=any one of Sn or Zr or a mixture thereof.

The addition of chloride MCl mainly combines with silver ions to form AgCl precipitation crystal nuclei. Obviously, if Ag ⁺ is to be completely precipitated to form crystal nuclei, the molar amount of Cl ^- added should be at least equivalent to that of Ag ⁺ ; at the same time, the addition of chloride is also necessary. Indispensably, if there is no chloride present, the subsequent addition of urea hydrolyzes to release ammonia, which will cause Ag ⁺ to form Ag(OH) ₂ precipitates, and then transform into Ag ₂ O precipitates. The appearance of Ag ₂ O is not conducive to the subsequent secondary reaction. The final product is not superfine, and the product also has the problem of easy discoloration when exposed to light. The purpose of adding the chloride MCl ₂ or MCl ₄ is to provide Cl ^- , and to provide metal ions in Zn, Sn, Cu, Sn or Zr to increase the overall performance of the product. Therefore, it is better to control the molar ratio of Ag ⁺ : Cl ^- at 1:1.2-10.

In the above preparation process, urea is used as a precipitating agent for metal ions because the ^OH- concentration in the solution gradually increases with the continuous production of ammonia during the hydrolysis of urea, forming a uniform precipitation coating in the entire solution. The reaction temperature should not be too high, otherwise urea will undergo isomerization condensation, so the reaction temperature should not be higher than 130°C; in order to ensure that the metal ions can be completely precipitated, the appropriate amount of urea is 1 to 4 times the theoretical amount; considering the reaction The liquid should have a higher concentration, and urea can be added in a solid state.

Soluble phosphate refers to M ₂ HPO ₄ or MH ₂ PO ₄ , M=K or Na. Considering the effect and price, it is better to choose Na ₂ HPO ₄ .

The compound surface modifier refers to the compound system of non-ionic and anionic surfactants. The non-ionic surfactants can be AEO-9, 6501, OP-10, TX-10, Tween-85, One or more of Tween-65, Span-80, polyethylene glycol-2000; the anionic surfactant can be AES, LAS, FAS-12, SDS, diffusing agent NNO, pull-open powder BX-78, One or several kinds of sodium polyacrylate. In the invention, the compounded surface modifier is directly added into the reaction system to modify the surface of solid particles, which can prevent the agglomeration of primary primary particles. The weight ratio of non-ionic and anionic surfactants is 1:0.2-2.0. The suitable dosage of the compounded surface modifier is 0.05-0.4 times of the weight of the product.

Because trivalent silver has a stronger bactericidal ability than monovalent silver, the product obtained above is further oxidized in potassium persulfate or sodium persulfate solution to obtain a trivalent silver ultrafine composite inorganic antibacterial agent, and the reaction temperature is 30 ~ 85 ℃, treatment for 3 to 8 hours, can further improve the antibacterial effect of antibacterial agents.

A certain concentration of titanium liquid is prepared from industrial-grade metatitanic acid through acidolysis, leaching, separation and purification, and a little excess sulfuric acid is used for acidolysis to increase the yield of acidolysis; the amount of leaching water should be moderate, too little leaching Incomplete, if it is too large, the stability of the titanium solution will be poor; the leaching temperature should also be moderate, if it is too low, it will affect the leaching rate and degree of leaching, if it is too high, the stability of the titanium solution will drop sharply, the content of colloids will increase, and premature hydrolysis will occur .

One of the following two methods is used for solid-liquid separation and dehydration drying:

a) Centrifuge to separate the liquid-solid system, wash the filter cake fully with water and then soak it with organic alcohol, and dry it at 60-110°C for 2-8 hours;

b) centrifuging the liquid-solid system, washing the filter cake fully with water, and dehydrating by azeotropic distillation in n-butanol.

Compared with the prior art, the present invention has the following advantages:

(1) The composite inorganic antibacterial agent of the present invention uses the silver ion precipitate as the sedimentation crystal nucleus, and the metal compound precipitation such as titanium and the phosphate precipitate are wrapped outside, and it exerts a long-acting antibacterial effect by slow-release antibacterial components. Its particle size is uniform, reaching ultra-fine level, and has a strong bactericidal effect; due to the effect of encapsulation, the antibacterial components are stable in the phosphate double salt crystals, which overcomes the poor killing effect of existing silver-based antibacterial agents on fungi, easy discoloration and Titanium antibacterial agents need light to exert their bactericidal effect and other disadvantages.

(2) Metal compounds such as silver and titanium, zirconium, tin and zinc are all antibacterial components, and phosphate and antibacterial components are combined and then dried and treated at high temperature to obtain a phosphate double salt crystal antibacterial agent. This type of double salt has a Nasicon-type crystal structure or a layered crystal structure with good ion exchange performance and strong ion exchange capacity. It has a durable antibacterial effect through slow release of antibacterial components or generation of active oxygen.

(3) The ultrafine inorganic antibacterial agent of the present invention can be widely used in fields such as processing such as textiles, plastics, paint, ceramic enamel and water treatment as additive; Its production cost is low, has good market prospect.

Detailed ways

Surfactant for short:

AEO-9 C12 fatty alcohol polyoxyethylene (9) ether

6501 Diethanolamine cocoate condensate

OP-10 Octylphenol polyoxyethylene (10) ether

TX-10 Nonylphenol polyoxyethylene (10) ether

Tween-85 Polyoxyethylene Sorbitan Trioleate

Tween-65 Polyoxyethylene Sorbitan Tristearate

Span-80 Sorbitan Oleate

AES Sodium fatty alcohol polyoxyethylene ether sulfate

LAS Linear Alkylbenzene Sulfonate

FAS-12 C12 Fatty Alcohol Sulfate

SDS Sodium Dodecyl Sulfate

Diffusion agent NNO Sodium methylene dinaphthalene sulfonate

Example 1:

Weigh the materials respectively according to the ratio of metatitanic acid: 98% sulfuric acid (wt)=1: 2.0～3.0, first dilute 98% sulfuric acid with deionized water to 70～90%, and place it in the reactor. Finely ground, sieved through a 325-400 mesh sieve, and then added to sulfuric acid; start the mixer to carry out acidolysis reaction. The reaction temperature is controlled between 70 and 130°C, and the reaction time is controlled between 10 and 40 minutes; deionized water is measured according to the ratio of metatitanic acid: deionized water (wt) = 1:3 to 5, and added to the reactor for leaching Acid hydrolysis product, the temperature is controlled between 40 ~ 70 ° C; filter out the insoluble matter to obtain titanium solution, the concentration of which is 80 ~ 210g/L (calculated as TiO ₂ , the same below), and calibrate for future use.

Measure titanium liquid 80ml (concentration is 180g/L) prepared by the above-mentioned method and add in the reactor, then add 4.52g anhydrous SnCl and _0.50g sodium chloride solution 20ml altogether, start agitator, add dropwise _10mlAgNO Solution ( containing AgNO ₃ 1.60g); then add 35.22g urea (in solid form, the same below), and react for 2h; then add dropwise 80ml of Na ₂ HPO ₄ solution (containing 20.17gNa ₂ HPO ₄ ·12H ₂ O), and stir for 1h ; Add 2 g of compounded surface modification (composed of AEO-9 and sodium polyacrylate, the weight ratio of which is 1:0.8) to the reaction system, and react for 0.5 h. After the reaction, the solid and liquid were separated by centrifugation to obtain a filter cake, which was fully washed with water, soaked twice with the same volume of absolute ethanol as the filter cake, and dried at 110° C. for 2 hours. The dried material was dispersed and calcined at 800° C. for 5 hours to obtain the product with an average particle size of 50 nm.

Antibacterial effect experiment, with reference to " Ministry of Health of the People's Republic of China Disinfection Technical Specifications (2002) " regulation, experimental procedure is as follows:

1. Accurately weigh a certain amount of antibacterial agent in a liquid medium, prepare a suspension with a predetermined concentration, place it in a conical flask, and sterilize it with saturated steam at 120°C for 25 minutes.

2. Add the prepared strains into sterile PBS, and control the concentration of the strains at 10 ⁵ -10 ⁶ cfu/ml.

3. Fix the Erlenmeyer flask on an oscillating shaker, keep the temperature at 37°C, oscillate at a speed of 200r/min, and start the contact sterilization.

4. After oscillating for a certain period of time, take out the sample solution from the conical flask, dilute it step by step, inoculate it on a plate with the agar pouring method, place it upside down in a 37°C incubator and cultivate it for 24-48 hours, and use the colony counting method to determine the concentration of the sample solution. bacteria content. Simultaneously, a blank experiment was performed as a control sample.

5. Calculation of the antibacterial efficiency of the antibacterial agent: bactericidal rate=1-(the number of colonies of the antibacterial sample/the number of colonies of the control sample).

Experimental result shows, concentration 100mg/L, when there is no light, the antibacterial agent prepared according to embodiment 1 reaches 98.5% in 30min killing rate to three kinds of bacteria such as Staphylococcus aureus, Escherichia coli and Candida albicans, 40min killing rate reaches 98.5%. 100%.

The antibacterial powder does not change color when exposed to sunlight and air for 72 hours.

Example 2:

Get 1g of the antibacterial agent prepared in Example 1, add it to 100ml of 0.05M potassium persulfate solution and react at 50°C for 6h, then filter, wash, and dry to obtain the antibacterial agent containing trivalent silver.

Antibacterial experiment result shows, concentration 100mg/L, when there is no light, the antibacterial agent prepared by embodiment 2 reaches 100% to the three kinds of bacteria described in example 1 20min killing rate.

Example 3:

Measure 55ml of titanium solution prepared according to the method of Example 1 (concentration is 150g/L), weigh ZrOCl ₂ 8H ₂ O 7.55g, dissolve it in 20ml deionized water, add it to the reactor, start the mixer, add 10ml AgNO ₃ solution (containing AgNO ₃ 1.00g); then add 47.07g urea and react for 3h; finally add dropwise 80ml of Na ₂ HPO ₄ solution (containing Na ₂ HPO ₄ ·12H ₂ O2 3.60g), react for 0.5h, add complex Prepared surface modifier (composed of OP-10 and pull-off powder BX-78, the weight ratio of the two is 1:0.4) 1.5g, reacted for 1h, after the reaction, centrifuged, and the filter cake was fully washed before use The filter cake was soaked three times with the same volume of 95% ethanol, and dried at 80°C for 10 hours. The dried material is dispersed and calcined at 1000°C for 3 hours to obtain the product with an average particle size of 90nm.

Antibacterial test results show that when the concentration is 100mg/L, when there is no light, the killing rate of the three bacteria described in Example 1 reaches 100% within 30 minutes.

The antibacterial powder does not change color when exposed to sunlight and air for 72 hours.

Example 4:

Measure 200ml of titanium liquid (concentration: 80g/L) prepared by the method in Example 1, weigh _{ZrOCl 2} 8H ₂ O 3.80g, anhydrous SnCl 2.68g, AgNO ₃ 1.50g, dissolve in 50, 10, 20ml Add deionized water, ZrOCl ₂ and SnCl ₄ solution into the reactor, start the mixer, drop AgNO ₃ solution; then add 47.88g urea, react for 4h; finally add 120ml Na ₂ HPO ₄ solution dropwise (containing 23.60gNa ₂ HPO ₄ ·12H ₂ O), reacted for 0.5h, added 1.8g of compounded surface modifier (composed of polyethylene glycol-2000 and FAS-12, the weight ratio of the two was 1:1), reacted for 1h. After the reaction finishes, centrifuge, after the filter cake is fully washed with water, drop into n-butanol and azeotropic distillation dehydration (n-butanol addition: water content in the filter cake=2: 3, weight ratio), the material after drying at 120 DEG C Break up and calcined at 1000°C for 3 hours to obtain the product with an average particle size of 180nm.

Antibacterial experiment result shows, concentration 100mg/L, when there is no light, the killing rate of three kinds of bacteria described in example 1 reaches 100% in 30min.

The antibacterial powder does not change color when exposed to sunlight and air for 72 hours.

Claims (8)

1, a kind of preparation method of superfine composite inorganic antimicrobial agent, its preparation process in turn includes the following steps:

A, be to add AgNO in 1～3 titanium liquid and the muriatic mixed solution to the pH value ₃Solution, stirring reaction 0.5～1h;

B, add urea then, at 50～130 ℃ of reaction 1～4h;

C, dropping soluble phosphate, reaction 0.5～1h;

D, the composite surface modifier of adding, reaction 0.3～1h;

E, Separation of Solid and Liquid, the drying that dewaters gets product at 700～1100 ℃ of calcining 2～10h;

Above-mentioned preparation method's molar ratio of material is Ti ⁴⁺: Ag ⁺: PO ₄ ^3-=5～15: 0.5～1: 2～10; Ag ⁺: Cl ^-=1: 1.2～10; Ti ⁴⁺: CO (NH ₂) ₂=1: 2～8, composite surface modifier is meant the compound system of the surfactant of nonionic and anionic, the surfactant weight ratio of nonionic and anionic is 1: 0.2～2.0, and the consumption of composite surface modifier is 0.05～0.4 times of product weight.

2, the preparation method of superfine composite inorganic antimicrobial agent according to claim 1 is characterized in that: the product that obtains further oxidation processes in persulfate solution can obtain trivalent silver superfine composite inorganic antimicrobial agent, and described persulfate is M ₂S ₂O ₈, M=NH wherein ₄, Na or K.

3, the preparation method of superfine composite inorganic antimicrobial agent according to claim 1 is characterized in that: titanium liquid is solubility titanium salt Ti (SO ₄) ₂, TiOSO ₄Or TiCl ₄Solution.

4, the preparation method of superfine composite inorganic antimicrobial agent according to claim 1 is characterized in that: titanium liquid obtains by the metatitanic acid sulfuric acid solution.

5, the preparation method of superfine composite inorganic antimicrobial agent according to claim 1 and 2, it is characterized in that: chloride is meant MCl, M=Na, K, H or NH ₄

Or MCl ₂, M=Zn, Sn or Cu;

Or MCl ₄, M=Sn or Zr, one of any or its mixture.

6, the preparation method of superfine composite inorganic antimicrobial agent according to claim 1 is characterized in that: nonionic surface active agent is one or more in AEO-9,6501, OP-10, TX-10, Tween-85, Tween-65, Span-80, the polyethylene glycol-2000; Anionic surfactant can be one or more in AES, LAS, FAS-12, SDS, dispersing agent NNO, Nekal BX-78, the Sodium Polyacrylate.

7, the preparation method of superfine composite inorganic antimicrobial agent according to claim 1 and 2, it is characterized in that: soluble phosphate is meant M ₂HPO ₄Or MH ₂PO ₄, M=K or Na.

8, the preparation method of superfine composite inorganic antimicrobial agent according to claim 7 is characterized in that: soluble phosphate is Na ₂HPO ₄