CN116139034A - Triazine sun-proof microcapsule and preparation method and application thereof - Google Patents

Abstract

The invention belongs to the technical field of fine chemicals, and discloses a triazine sun-proof microcapsule and a preparation method thereof. Dissolving diethyl hexoxyphenol methoxyphenyl triazine and octyl triazinone in an organic solvent, adding an emulsifying agent and a gelatin solution for homogenizing and emulsifying, and performing rotary evaporation on an emulsifying system at 40-60 ℃ and negative pressure of minus 0.2-0.5 MPa to obtain submicron-level sun-screening particle dispersion; and mixing gelatin solution, sodium alginate solution and submicron-sized sun-screening particle dispersion, regulating the pH value of a mixed system to be 4.0-4.5, carrying out complex coacervation at 40-50 ℃, adding calcium chloride solution into a gel system, carrying out crosslinking at 5-10 ℃, regulating the pH value of the system to be 6.0-6.5, and drying to obtain the triazine sun-screening microcapsule. The microcapsule has good ultraviolet absorption, and can reduce penetration of chemical ultraviolet absorbent into skin, and cause skin irritation such as photo-allergy and phototoxic reaction.

Description

Triazine sun-proof microcapsule and preparation method and application thereof

Technical Field

The invention belongs to the technical field of fine chemicals, and particularly relates to a triazine sun-proof microcapsule, and a preparation method and application thereof.

Technical Field

The spectrum of solar rays is wide and can be divided into ultraviolet radiation (200-400 nm), visible light (400-700 nm) and infrared radiation (700-3000 nm), and although the ultraviolet radiation only accounts for 5% of all the radiation, the ultraviolet radiation plays an important role in photoaging and skin cancer. The international commission on illumination divides ultraviolet light into three specific bands, wherein 100-280nm ultraviolet light is short wave Ultraviolet (UVC), 280-315nm ultraviolet light is medium wave Ultraviolet (UVB), and 315-400nm ultraviolet light is long wave Ultraviolet (UVA). In general, UVC cannot reach the earth's surface due to absorption by the atmosphere, and only medium-wave Ultraviolet (UVB) and long-wave Ultraviolet (UVA) remain to reach the earth's surface. UVB penetrates into the stratum corneum of human skin, and a small amount of UVB irradiation can promote metabolism and vitamin D formation in the body, but long-term irradiation can tan skin to form sunburn and erythema; the UVA can penetrate the epidermis of the skin to reach the dermis layer, and after the epidermis is irradiated by the UVA for a long time, elastic fibers and collagen fibers of the skin are seriously damaged, so that melanin precipitation is caused, the skin is blackened and roughened, and pigments are accumulated to form black spots over time. The International cancer research institute has pointed out that there is sufficient evidence that ultraviolet radiation is a human carcinogen (Gallagher R P, lee T K. Adverse effects of ultraviolet radiation: a brief review [ J ]. Progress in Biophysics and Molecular Biology,2006,92 (1): 119-131).

As people slowly realize that ultraviolet radiation is harmful to skin, more and more people can use sun protection products to be smeared on the skin to protect the skin from ultraviolet radiation when going out, such as sun protection cream, sun protection spray and the like. However, the national health sector strictly prescribes the types and dosages of organic ultraviolet absorbers that can be added to sunscreen products, and numerous studies have shown that the safety and skin penetration of organic ultraviolet absorbers remain a concern for consumers, and the European Commission's consumer product science Committee indicates that many sunscreen molecules are able to penetrate the skin, cause photosensitization, phototoxic reactions and skin irritation (Gonzalez H.Percutaneous absorption with emphasis on sunscreens [ J ]. Photochemical & Photobiological Sciences,2010,9 (4): 482-488).

The diethyl hexoxyphenol methoxyphenyl triazine is a novel oil-soluble Jiang Anpu sun-screening agent, can absorb UVA and UVB simultaneously, has good UVA absorption effect, but has general UVB absorption effect; octyl triazone is an oil soluble UVB sunscreen with very strong absorption of UVB, but little absorption of UVA. Therefore, the two components can well make up the respective defects, and the strong spectrum absorption capability of the sunscreen cream is endowed. However, since both are insoluble in water, they are used with oils of strong polarity such as C _12～15 The compound use of alkanol benzoate, caprylic/capric triglyceride, dioctyl carbonate and the like can reduce the refreshing property of a sun-screening product, and simultaneously oily raw materials can permeate into skin together with a chemical ultraviolet absorbent to cause adverse reactions such as skin allergy, phototoxicity, skin irritation and the like. There have been some studies to date that bisethylhexyl oxyphenoxyphenyl triazine (Tinosorb S) causes allergic contact dermatitis (Eric Chatelain, bernard Gabard "Photostabilization of Butyl methoxydibenzoylmethane (Avobenzone) and Ethylhexyl methoxycinnamate by Bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb S), a New UV Broadband Filter," Photochemistry and Photobiology,74 (3), 401-406, (1 September 2001)).

The appearance of the capsule technology just meets the pursuit of people for food of pursuit of nature, advocate health, convenient requirement and chong of delicacy. The microcapsule has many preparation methods, such as a coacervation method, a phase separation method in an organic phase system, an interfacial polymerization method, an emulsion polymerization method and the like, and the phase separation method of the organic phase system needs a large amount of organic solvents, is not friendly to the environment, and the interfacial polymerization method and the emulsion polymerization method need semi-synthetic polymers or synthetic polymer materials, and have certain toxicity and poor biocompatibility. Therefore, the organic ultraviolet absorbent is smeared on the surface of a human body, the skin is protected from being injured, and the sun cream has good refreshing property, so that the sun cream has become a difficult problem in the research and development of the sun cream products at present.

Disclosure of Invention

In order to solve the defects and shortcomings of the prior art, the invention aims to provide a preparation method of triazine sun-screening microcapsules. The method prepares submicron-sized sun-screening particle dispersion by a solvent volatilization method, and then mixes high molecular wall material gelatin with better biocompatibility with sodium alginate to carry out complex coacervation coating on sun-screening particles to form triazine sun-screening microcapsules with core-shell structures. The invention solves the problems that (1) most triazine organic ultraviolet light absorber needs to be dissolved in grease for use in use, and the greasy feeling is felt in the use process; (2) The triazine organic ultraviolet absorbent has poor dispersibility and non-uniformity in water and fresh cream, and the organic ultraviolet absorbent directly contacts with the skin to cause damage to the skin; (3) The chemical ultraviolet absorber of the sun-screening products on the market causes skin allergy and other problems.

It is another object of the present invention to provide triazine sunscreen microcapsules prepared by the above method. The triazine sun-proof microcapsule has excellent safety, sun-proof performance, high dispersibility and stability, and can be absorbed in a wide ultraviolet wave band.

It is a further object of the present invention to provide the use of the triazine sunscreen microcapsules described above.

The aim of the invention is achieved by the following technical scheme:

a preparation method of triazine sun-proof microcapsules comprises the following steps:

s1, adding gelatin into deionized water, stirring, heating and dissolving at 40 ℃ to obtain a clear gelatin solution; adding sodium alginate powder into deionized water, stirring at 40deg.C, heating for dissolving to obtain clarified sodium alginate solution.

S2, dissolving the sun-screening agents of diethyl hexoxyphenol methoxyphenyl triazine and octyl triazone in an organic solvent, adding an emulsifying agent and 1-10wt% of gelatin solution for homogenizing and emulsifying to obtain an emulsifying system;

s3, performing rotary evaporation on the emulsifying system at the temperature of 40-60 ℃ and the negative pressure of-0.2-0.5 MPa to obtain submicron-level sun-screening particle dispersion;

s4, mixing a gelatin solution, a sodium alginate solution and a submicron-sized sun-screening particle dispersion, regulating the pH value of a mixed system to be 4.0-4.5, and performing complex coacervation at 40-50 ℃ to obtain a gel system;

s5, adding a calcium chloride solution into the gel system, crosslinking for 30-60 min at the temperature of 5-10 ℃, adjusting the pH value of the system to 6.0-6.5 after the crosslinking is finished, and drying to obtain the triazine sun-proof microcapsule.

Preferably, the mass ratio of the bisethylhexyloxyphenol methoxyphenyl triazine to the octyl triazone in the sunscreen in the step S1 is 1: (0.1 to 0.3); the mass ratio of the sun-screening agent to the organic solvent is 1 (2-5); the organic solvent is dichloromethane, petroleum ether, n-hexane or ethyl acetate; the emulsifier is more than one of span 20, tween-80 or hexadecyl phosphate potassium salt, and the emulsifier is 0.7-1.3wt% of the organic solvent; the gelatin is type B gelatin.

Preferably, the rate of the homogenizing emulsification in the step S1 is 6000-18000 rpm, and the time of the homogenizing emulsification is 3-10 min.

Preferably, the rotating speed of the rotary steaming in the step S2 is 50-200 revolutions/min, and the rotary steaming time is 50-100 min.

Preferably, the submicron-sized sunscreen particle dispersion in step S2 has a particle size of 400nm to 4 μm.

Preferably, the concentration of the gelatin solution in the step S3 is 0.5-1 wt%, and the concentration of the sodium alginate solution is 0.1-1 wt%; the mass ratio of the gelatin solution to the sodium alginate solution to the submicron-sized sun-screening particle dispersion is (1-10) 1 (1-2); the gelatin solution and the sodium alginate solution are 0.5-1 wt% of the total mass of the gelatin solution, the sodium alginate solution and the submicron-sized sun-screening particle dispersion.

Preferably, the calcium chloride in the calcium chloride solution in step S4 is 0.1 to 0.5wt% of the gel system.

Preferably, the drying in step S4 is freeze-drying or spray-drying.

A triazine sun-screening microcapsule is prepared by the method.

The triazine sun-proof microcapsule has high dispersibility and broad-spectrum protection, hydrophobic and oil-soluble diethyl hexyloxy phenol methoxy phenyl triazine and octyl triazone are compressed into submicron-level particle dispersion with better dispersibility in water by a solvent volatilization method, and then are wrapped by natural materials. The bisethylhexyl oxyphenol methoxy phenyl triazine and the octyl triazone are coated with the gelatin-sodium alginate with good hydrophilicity and biocompatibility, so that the stability, the dispersity and the hydrophilicity of the bisethylhexyl oxyphenol methoxy phenyl triazine and the octyl triazone are greatly improved, the skin and the triazine sun-screening agent can be effectively isolated, and the irritation of the organic ultraviolet absorber to the skin is reduced. Therefore, the application prospect of the p-diethyl hexyloxy phenol methoxy phenyl triazine and octyl triazone microcapsule is wide, the operability is strong, and the novel sunscreen agent with high stability and safety is easier to obtain.

The working principle of the invention is as follows:

conventional sunscreen formulations are formulated with polar oils and fats to dissolve (e.g., C _12～15 Alcohol benzoate, caprylic/capric triglyceride, dioctyl carbonate, etc.), can be added into water to be emulsified and dispersed uniformly. When a small portion of the non-polar organic solvent is dispersed in water, the non-polar organic solvent is the internal phase and water is the continuous external phase, an oil-in-water (O/W) emulsion can be formed, but this mixture is unstable and the oil-in-water emulsion will normally phase completely in a few seconds if no emulsifier is present. The surface active protein with the hydrophilic group and the lipophilic group can be used as an emulsifier to stabilize an oil-water interface so as to prevent emulsion phase separation, but the emulsification effect of the gelatin colloid as the emulsifier is not very good, and generally, large-particle-size emulsion tends to be formed, and a small amount of emulsifier (such as span 20 or span 80) is added so as to obtain emulsion with smaller particle size. When the sun-screening agent diethyl hexyloxy phenol methoxy phenyl triazine and octyl triazone are dissolved in an organic solvent to form emulsion, the organic solvent is volatilized continuously in the rotary evaporation process, the emulsion is heated uniformly during the rotary evaporation, spherical emulsion drops are reduced uniformly continuously, and the amount of the organic solvent is volatilized to be insufficient to dissolve the sun-screening agent, so that the sun-screening agent is prevented from being dissolvedThe sun-screening agent can be separated out to gradually form spherical micro-nano particles (namely particle dispersion), and compared with the common irregular sun-screening agent particles, the micro-nano particles have smaller particle size and better dispersion performance in water.

Gelatin is an amphoteric polymer material, and has a plurality of groups on the molecular chain, wherein the change of the charge quantity on amino and carboxyl is the most influenced in the whole complex coacervation process. The isoelectric point of the type B gelatin is between 4.5 and 6.0, when the pH is higher than the isoelectric point, the amino group is changed into-NH ₂ While the carboxyl group becomes negatively charged-COO ^- The gelatin solution of type B at this time is negatively charged. Formation of-NH due to the deprotonation effect of amino groups in type B gelatin ⁺ The carboxyl protonation effect forms-COOH, which positively charges the gelatin as the pH gradually decreases. At the same time, due to the carboxyl groups of the alpha-L-guluronic acid and the beta-D-mannuronic acid and Na in the sodium alginate ⁺ Ionization makes the molecular chain segment of sodium alginate negatively charged, at this time, the electrostatic interaction induction can be produced between gelatin and sodium alginate, and complex coacervation action can be implemented (coacervation means that one substance is coacervated in solution due to environmental change, and complex coacervation means that two substances are coacervated in solution due to interaction).

Gelatin has both hydrophilic and hydrophobic groups, and thus has good emulsifying and foaming properties. Homogenizing and emulsifying a sun-screening agent and a gelatin solution, forming an oil/gelatin solution (O/W emulsion) by gelatin molecules and an organic solvent dissolved with the sun-screening agent, rotating to remove the organic solvent to obtain a submicron sun-screening particle dispersion, adding sodium alginate, adjusting pH value to ensure that the gelatin is positively charged, adsorbing the gelatin by the sodium alginate to form spherical microcapsules, and adding Ca ²⁺ Complexing with sodium alginate to form an egg box structure, solidifying the capsule wall of the microcapsule, improving the compactness of the microcapsule and enhancing the strength of the capsule wall.

The triazine sun-screening agent molecule contains an intramolecular hydrogen bond participated by a hydroxyl or amino group and forms a six-membered ring with N atoms, the six-membered ring and surrounding structures form a conjugated system, the optical band gap of the conjugated system is similar to the ultraviolet light energy in the UVA and UVB ranges, after the molecule itself absorbs ultraviolet light, the molecular energy is increased, N-H bonds in the conjugated system are broken, the structure becomes unstable after the hydrogen bond is broken, the absorbed ultraviolet light energy is easily converted into harmless heat energy, fluorescence, phosphorescence and other forms to be released, and meanwhile, the molecular structure is restored to the original structure, so that the effect of absorbing ultraviolet light is achieved. The diethyl hexoxyphenol methoxyphenyl triazine has phenolic hydroxyl and extremely strong hydrogen bond action, so that the diethyl hexoxyphenol methoxyphenyl triazine has very good UVA absorption capacity; the octyl triazinone has N-H hydrogen bond action, weak UVA absorption capacity but excellent UVB absorption capacity, and can have excellent UVA and UVB absorption capacity when being compounded, and meanwhile, the octyl triazinone has similar chemical structures and good compatibility.

Wherein, the chemical structural formula of the bisethylhexyloxyphenol methoxyphenyl triazine sun-screening agent is as follows:

the chemical structural formula of the octyl triazinone sun-screening agent is as follows:

compared with the prior art, the invention has the following beneficial effects:

1. according to the invention, the natural polymer material is adopted to prepare the microcapsule by adopting a complex coacervation method, the biopolymer is natural and nontoxic and degradable, the biocompatibility is good, the solvent volatilization method is adopted to compress the sun-screening agent to submicron level, the dispersibility in water is greatly increased, and because the sun-screening agent is hydrophobic, if the sun-screening agent is directly coated by the natural polymer material, the sun-screening agent can be directly and uniformly dispersed in water without dissolving grease, and the defects of fresh skin feel, greasy feel and the like of the existing high SPF sun-screening cream are overcome by reducing the addition of oily raw materials in the sun-screening cream.

2. According to the triazine sun-screening microcapsule disclosed by the invention, the oil-soluble diethyl hexoxyphenol methoxyphenyl triazine and octyl triazone sun-screening agent is coated by the gelatin-sodium alginate, so that the triazine sun-screening microcapsule can be well dispersed in water, does not delaminate after long-term placement, and has a good embedding rate for the triazine sun-screening agent.

3. The triazine sun-proof microcapsule has excellent safety, sun-proof performance, dispersibility and stability, ultraviolet broad-spectrum protection, good protection effect on UVA and UVB, and good biocompatibility, and the capsule wall is made of natural polymer materials.

4. The preparation raw materials of the invention exist in a large amount in the nature, the operation of the production process is simple, the particle size of the microcapsule can be regulated by the homogenization speed and the homogenization time, the particle size distribution of the microcapsule can be controlled, the quality control is simple, the organic solvent used in the preparation process can be recycled by a rotary evaporation method, and the production process is environment-friendly and does not pollute the environment.

Drawings

FIG. 1 is a standard curve of the bis-ethylhexyloxyphenol methoxyphenyl triazine sunscreen and the octyl triazone of the present invention dissolved in ethyl acetate, respectively;

FIG. 2 is a graph showing particle size distribution of particle dispersions in microcapsules prepared in examples 7-9;

FIG. 3 is an optical microscopic image of the triazine microcapsules of examples 4 and 7;

FIG. 4 is a graph showing the particle size distribution of triazine microcapsules of examples 4 and 7;

FIG. 5 shows dispersion stability of microcapsules prepared in example 7;

FIG. 6 is an ultraviolet absorption diagram of the triazine sunscreen microcapsules of example 7;

FIG. 7 is an infrared comparison of triazine microcapsules, blank microcapsules, bis-ethylhexyloxyphenol methoxyphenyl triazine and octyl triazone sunscreens of example 7.

Detailed Description

The present invention is further illustrated below in conjunction with specific examples, but should not be construed as limiting the invention. The technical means used in the examples are conventional means well known to those skilled in the art unless otherwise indicated. Unless specifically stated otherwise, the reagents, methods and apparatus employed in the present invention are those conventional in the art.

Examples

1. Adding 1g of gelatin into 100g of deionized water, stirring, heating and dissolving at 40 ℃ to obtain a clear 1% gelatin solution; adding 1g of sodium alginate powder into 200g of deionized water, stirring, heating and dissolving at 40 ℃ to obtain 0.5% sodium alginate solution; different gelatin-sodium alginate solutions were prepared according to the mass ratios of gelatin to sodium alginate in table 1.

2. The mass ratio is 1: (0.1-0.3) 1g of bisethylhexyloxyphenol methoxyphenyl triazine and octyl triazone are dissolved in 5g of dichloromethane to obtain yellow clear solution, then 100g of 1% gelatin solution and 0.05g of tween-80 are added, the mixture is homogenized and emulsified to obtain O/W emulsion (the mixture of milky white and pale yellow, the O/W emulsion is put into a rotary evaporator to be subjected to rotary evaporation for 50-100 min at the temperature of 50 ℃ and the negative pressure of minus 0.4MPa and the rotating speed of 50-200 r/min, and after the dichloromethane is volatilized, the organic solvent in the rotary evaporation device is collected to wait for repeated use, so as to obtain the triazine sun-screening particle dispersion.

2. Preparing a triazine sun-screening particle dispersion and a gelatin-sodium alginate solution into a 1% gelatin-sodium alginate solution, stirring the gelatin-sodium alginate solution at 400-600 r/min, regulating the pH value in the system to 4.2, performing complex coacervation reaction for 10min under water bath stirring at 40 ℃ to obtain a gel system, adding 100mL of distilled water into the gel system for dilution, adding 3g/30mL of calcium chloride aqueous solution for crosslinking and curing, water bath for 30min at 5-10 ℃, regulating the pH value to 5.8-6.5 after the crosslinking is finished, and performing spray drying or freeze drying to obtain the triazine sun-screening microcapsule.

Because the microcapsule cannot be 100% wrapped, the embedding rate can be changed under different conditions, and some microcapsules are possibly damaged in the wrapping process due to different process conditions, so that the contact between the capsule core and the outside is caused in the using process, and the contact between the capsule core and the surface of a human body can cause allergy or penetration into the human body; the higher the embedding rate, the better the wrapping of the raw materials by the condition is proved, the smaller the raw material loss is, and the less the generated harm is. Microcapsule embedding rate (%) = (m) ₁ -m ₂ )/m _1* 100% of formula (1), wherein m ₂ Is the total mass of the bisethylhexyloxyphenol methoxyphenyl triazine and the octyl triazone contained in the triazine sun-proof microcapsule, and m ₁ The total mass of the sunscreen particle dispersion added in step 2.

Adding 10mL of ethyl acetate into 20mg of triazine sun-screening microcapsule powder, taking 0.1mL of ethyl acetate solution of triazine sun-screening microcapsule from the ethyl acetate solution, carrying out constant volume in a constant volume bottle of 10mL to prepare 20mg/L microcapsule-ethyl acetate solution, washing sun-screening agent on the surface of the microcapsule by ethyl acetate, filtering the microcapsule solution by an organic filter membrane to obtain ethyl acetate clear liquid, and measuring absorbance A of lambda=350 nm and lambda=307 by using a double-beam ultraviolet spectrophotometer _350nm 、A _307nm Obtaining the mass m of the bisethylhexyloxyphenol methoxyphenyl triazine and the octyl triazone in the microcapsule by comparing the standard curves of the bisethylhexyloxyphenol methoxyphenyl triazine and the octyl triazone in the FIG. 1 (b) and the FIG. 1 (d) ₂ And m is ₁ The total mass of the dispersion of sunscreen particles added in example step 2.

Table 1 different raw material ratios and process conditions and embedding rate and dispersibility in the sunscreen microcapsules of examples 1 to 10

Standard detection environmental conditions: temperature: (23+ -2) deg.C, relative humidity: (50.+ -. 5)%.

1. Particle size testing: the particle size and particle size distribution of submicron-order sun-screening particles and sun-screening microcapsules are determined by using a Markov Mastersizer 3000 laser diffraction particle sizer. The dispersed sample is put into a sample cell equipped with an instrument, the measurement temperature is 25 ℃, the dispersion system is water, the lower limit of the shading degree is 10%, and the upper limit is 15%. Wherein the refractive index of the sunscreen microcapsules was set to 1.35 and the refractive index of the submicron sunscreen particles was set to 1.56.

2. Ultraviolet absorbance test:

(1) Aqueous ultraviolet absorbance test: dispersing a trace amount of sun-screening microcapsules in a water solution with the mass ratio of 100 times, shaking manually until the sun-screening microcapsules are completely dispersed, taking 2mL of the water solution of the sun-screening microcapsules in a glass slide with the mass ratio of 2cm x 5cm by using a pipette, and testing an ultraviolet absorption spectrum of the water solution of the sun-screening microcapsules by using an ultraviolet-visible spectrophotometer.

(2) Powder ultraviolet absorption test: and (3) dispersing a proper amount of solid sun-proof microcapsule powder in the center of the sample vessel, covering the sample vessel with dry barium sulfate, screwing the sample vessel, and directly testing a solid ultraviolet absorption spectrum by using an ultraviolet visible near infrared spectrophotometer.

3. Dispersibility test: and (5) re-dispersing a proper amount of solid sun-screening microcapsule powder into water, observing the sedimentation condition of the sun-screening microcapsule powder at intervals, and recording.

4. Infrared absorption spectrum test: and (3) adding KBr into a small amount of sun-proof microcapsule solid powder and control group powder for grinding, tabletting, and directly placing on a sample frame for measuring infrared absorption broad spectrum. The scanning range of FTIR is set to 500-4000 cm ^-1 Resolution of 4cm ^-1 。

Table 1 shows the entrapment and dispersion properties of triazine sunscreen microcapsules according to different ratios of raw materials and process conditions in examples 1 to 10. As can be seen from Table 1, when the mass ratio of gelatin to sodium alginate is 1:1, the embedding rate of the diethyl hexoxyphenol methoxyphenyl triazine microcapsule is 88.63% at the highest, and when the content of sodium alginate is too high, the sun-proof microcapsule is adhered, the dispersibility is extremely poor, and the sun-proof microcapsule is easy to settle. When the mass ratio of gelatin to sodium alginate is 5:1, the homogenization speed is 16000 r/min, the homogenization time is 10min, and the wall core mass ratio is 1:1 (the wall is gelatin/sodium alginate, the core is diethyl hexoxyphenol methoxyphenyl triazine and octyl triazone), the embedding rate of the obtained triazine sun-proof microcapsule is 85.68% at the highest, and the dispersibility is the best. As the homogenization time and rate increase, the particle size of the sunscreen microcapsules gradually decreases, and the smaller the particle size, the better the dispersibility. Therefore, the optimal condition is that the mass ratio of gelatin to sodium alginate is 5:1, the mass ratio of wall core is 1:1, the homogenization time is 10min, and the homogenization rotating speed is 16000 revolutions/min.

FIG. 1 is a standard curve of the bis-ethylhexyloxyphenol methoxyphenyl triazine and octyl triazone of the present invention; wherein, (a) is the ultraviolet absorption spectrum of 10-30 mg/L of diethyl hexoxyphenol methoxyphenyl triazine, (b) is the standard curve graph of diethyl hexoxyphenol methoxyphenyl triazine, (c) is the ultraviolet absorption spectrum of 10-30 mg/L of octyl triazone, and (d) is the standard curve graph of octyl triazone. (e) Ultraviolet absorption spectra of bisethylhexyloxyphenol methoxyphenyl triazine, octyl triazone and bisethylhexyloxyphenol methoxyphenyl triazine and octyl triazone. As can be seen from fig. 1, the bisethylhexyloxyphenol methoxyphenyl triazine has a certain absorption intensity in a wavelength range of 300-375nm, but the absorption intensity at about 300nm is not as high as that of the octyl triazone, and after the bisethylhexyloxyphenol methoxyphenyl triazine and the octyl triazone are compounded, the absorption intensity of the UVA and the UVB is stronger than that of the bisethylhexyloxyphenol methoxyphenyl triazine and the octyl triazone when the bisethylhexyloxyphenol methoxyphenyl triazone and the octyl triazone are singly used, because the N-H bond in the octyl triazone participates in enhancing the hydrogen bond effect of the octyl triazone after the chelate ring formed by the hydrogen bond effect of the bisethylhexyloxyphenol methoxyphenyl triazone contacts with the octyl triazone with a similar chemical structure, the ring opening energy of the chelate ring is enhanced, the absorption intensity of the bisethylhexyloxyphenol methoxyphenyl triazone and the octyl triazone is increased, the sun-proof effect is enhanced, and the synergistic effect of the compounding of the bisethylhexyloxyphenol methoxyphenyl triazone and the octyl triazone is proved to lead the sun-proof microcapsule to have a better broad-spectrum protection effect.

Fig. 2 is a particle size distribution of the particle dispersion in the triazine sunscreen capsules of examples 7-9. As can be seen from fig. 2, the particle size of the dispersion of sun-protecting particles prepared by the homogeneous conditions of examples 7 to 9, in which the particle size of the dispersion of triazine sun-protecting particles was 400nm to 4um, exhibited a normal distribution, a single and narrow distribution curve. Since examples 1 to 6 had a short homogenization time and a slow homogenization time, the emulsion droplets formed had a large particle size, and the precipitated particles were also large, and the particle size of the microcapsules formed was also increased, and the homogenization conditions affected the particle size of the dispersion of sun-protecting particles, and thus the particle size of the microcapsules.

Fig. 3 is an optical micrograph of triazine sunscreen microcapsules of examples 4 and 7. As can be seen from fig. 3, the triazine sunscreen microcapsules of example 4 have a core-shell structure, and the triazine sunscreen agent is successfully encapsulated in the microcapsule wall, so as to avoid touching contact with the outside, avoid direct contact of the triazine sunscreen agent with the surface of the human body, and the triazine sunscreen microcapsules adhere to the surface of the skin of the human body to form a protective effect. The triazine sunscreen microcapsules of example 4 show semitransparent walls, so the triazine sunscreen microcapsules of examples 4 and 7 increase refraction and diffusion of ultraviolet light between the microcapsule core and the capsule cavity, thereby improving sunscreen performance.

Fig. 4 is a particle size distribution diagram of triazine sunscreen microcapsules of example 4 and example 7. As can be seen from fig. 4, the average particle size of the triazine sunscreen microcapsules of example 4 is 56um, and the average particle size of the triazine sunscreen microcapsules of example 7 is 5.6um, which indicates that the triazine sunscreen microcapsules with different particle sizes (1-100 um) can be prepared by controlling different parameters of homogeneous emulsification, and the regulation of the particle sizes of the microcapsules is realized.

Fig. 5 shows the dispersion stability of the triazine sunscreen microcapsules of example 7 in water, wherein (a) shows the sedimentation effect of the sunscreen microcapsules of example 7 in water for 24 hours, and (b) shows the dispersion effect of the bis-ethylhexyloxyphenol methoxyphenyl triazine and octyl triazone of example 7 in water at a mass ratio of 0.75:0.25, respectively, to the non-microencapsulated sunscreen microcapsules. As can be seen from fig. 5 (a), the triazine sunscreen microcapsules did not exhibit any sedimentation behavior in the aqueous solution for 4 hours, the sunscreen microcapsules exhibited slight sedimentation behavior at 8 hours, the solution was slightly less turbid, after 12 hours, a clear sedimentation behavior was observed, and after 24 hours the solution became clear. The smaller the particle size of the microcapsule, the longer the sedimentation time, and the better the dispersion in water. As can be seen from fig. 5 (b), the triazine sunscreen microcapsules can achieve a good dispersion effect after being stirred in deionized water for 1min, but the bis-ethylhexyloxyphenol methoxyphenyl triazine and octyl triazone which are not subjected to microencapsulation have a mass ratio of 0.75:0.25, and even if being subjected to ultrasonic treatment in a 100W ultrasonic microwave cleaner for 5min, the triazine sunscreen microcapsules still cannot be dispersed on the water surface, which indicates that the bis-ethylhexyloxyphenol methoxyphenyl triazine and octyl triazone can be endowed with a good dispersion effect in water through microencapsulation.

FIG. 6 is an ultraviolet absorption diagram of the triazine sunscreen microcapsule solution and powder of example 7, wherein (a) the triazine sunscreen microcapsule of example 7 (bis-ethylhexyloxyphenol methoxyphenyl triazine: octyltriazone in a mass ratio of 0.75:0.25) is dissolved in C _12～15 Alkanol benzoate (TS-T150), triazine sunscreen microcapsule aqueous solution and blank microcapsule aqueous solution. (b) The triazine sunscreen microcapsule powder of example 7, and blank microcapsule powder. As can be seen from FIG. 6, the aqueous solution of triazine sunscreen microcapsules of example 7 and C _12～15 The alkanol benzoate solution has ultraviolet absorption peak in the wavelength range of 300-400 nm, and the ultraviolet absorption effect of the aqueous solution of the triazine sun-proof microcapsule is better than that of the triazine sun-proof microcapsule dissolved in C _12～15 The ultraviolet absorption effect in alkanol benzoate, while the blank microcapsule (example 10) does not have the ultraviolet absorption effect, the ultraviolet absorption capability of the triazine sunscreen microcapsule in the wavelength of 200-400nm is even better than that of the triazine sunscreen agent which is not subjected to microencapsulation, so that the triazine sunscreen microcapsule is proved to successfully wrap the triazine sunscreen agent and enhance the ultraviolet absorption capability.

FIG. 7 is a graph comparing IR analysis of triazine based sunscreens, blank microcapsules, unencapsulated bis-ethylhexyloxyphenol methoxyphenyl triazine and octyl triazone sunscreens of example 7. As can be seen from FIG. 7, there is 3500cm characteristic peak of bisethylhexyloxyphenol methoxyphenyl triazine ^-1 Stretching vibration of phenolic hydroxyl group 1371cm ^-1 Flexural vibration in phenolic hydroxyl basal plane of 1109cm ^-1 Ar-O-C ether linkage stretching vibration 1270cm ^-1 Is C-N carbon nitrogen single bond telescopic vibration of 1628cm ^-1 Stretching and vibrating for C=N double bond, and simultaneously, octyl triazinone at 1720cm ^-1 The characteristic peak of the stretching vibration of the ester group c=o was found. Triazine sun-proof microcapsule is 1270cm ^-1 There is a similar C-N single bond stretching vibration strong absorption peak at 1628cm ^-1 The C=N double bond stretching vibration characteristic peak is found to be 1109cm ^-1 Diethylhexyloxyphenol is also presentMethoxyphenyl triazine (wherein the labeled sun-screening agent T-S is referred to as diethyl hexoxyphenol methoxyphenyl triazine for short) Ar-O-C ether bond telescopic vibration absorption peak, 1720cm ^-1 There is also octyl triazinone ester group C=O stretching vibration, and the infrared spectrogram of the blank microcapsule has no obvious sharp characteristic absorption peak at the three positions, which proves that the triazine sun-proof microcapsule contains diethyl hexyloxyphenol methoxyphenyl triazine and octyl triazinone, and the method can effectively wrap the sun-proof agent.

The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, and the embodiments are included in the protection scope of the present invention.

Claims (10)

1. A preparation method of triazine sun-proof microcapsules comprises the following steps:

s1, dissolving a sun-screening agent of diethyl hexoxyphenol methoxyphenyl triazine and octyl triazone in an organic solvent, adding an emulsifying agent and 1-10wt% of gelatin solution for homogenizing and emulsifying to obtain an emulsifying system;

s2, performing rotary evaporation on the emulsifying system at the temperature of 40-60 ℃ and the negative pressure of minus 0.2-minus 0.5MPa to obtain submicron-level sun-screening particle dispersion;

s3, mixing a gelatin solution, a sodium alginate solution and a submicron-sized sun-screening particle dispersion, regulating the pH value of a mixed system to be 4.0-4.5, and performing complex coacervation at 40-50 ℃ to obtain a gel system;

s4, adding a calcium chloride solution into the gel system, crosslinking for 30-60 min at 5-10 ℃, then adjusting the pH value of the system to 6.0-6.5, and drying to obtain the triazine sun-proof microcapsule.

2. The preparation method of the triazine sun-screening microcapsule according to claim 1, wherein the mass ratio of the bisethylhexyloxyphenol methoxyphenyl triazine to the octyl triazone in the sun-screening agent in the step S1 is 1: (0.1 to 0.3); the mass ratio of the sun-screening agent to the organic solvent is 1 (2-5); the organic solvent is dichloromethane, petroleum ether, n-hexane or ethyl acetate; the emulsifier is more than one of span 20, tween-80 or hexadecyl phosphate potassium salt, and the emulsifier is 0.7-1.3wt% of the organic solvent; the gelatin is type B gelatin.

3. The method for preparing triazine sun-protection microcapsules according to claim 1, wherein the rate of homogeneous emulsification in step S1 is 6000-18000 rpm, and the time of homogeneous emulsification is 3-10 min.

4. The method for preparing triazine sun-screening microcapsules according to claim 1, wherein the particle size of the submicron sun-screening particle dispersion in step S2 is 400nm to 4 μm.

5. The preparation method of the triazine sun-protection microcapsules according to claim 1, wherein the rotational speed of the rotary steaming in the step S2 is 50-200 rpm, and the rotary steaming time is 50-100 min.

6. The preparation method of the triazine sun-protection microcapsules according to claim 1, wherein the concentration of the gelatin solution in the step S3 is 0.5-1 wt%, and the concentration of the sodium alginate solution is 0.1-1 wt%; the mass ratio of the gelatin solution to the sodium alginate solution to the submicron-sized sun-screening particle dispersion is (1-10) 1 (1-2); the gelatin solution and the sodium alginate solution are 0.5-1 wt% of the total mass of the gelatin solution, the sodium alginate solution and the submicron-sized sun-screening particle dispersion particles.

7. The method for preparing triazine sun-protection microcapsules according to claim 1, wherein the calcium chloride in the calcium chloride solution in step S4 is 0.1-0.5 wt% of the gel system.

8. The method for preparing triazine sun-protection microcapsules according to claim 1, wherein the drying in step S4 is freeze-drying or spray-drying.

9. A triazine sunscreen microcapsule prepared by the method of any one of claims 1 to 8.

10. Use of the triazine sunscreen microcapsules of claim 9 in the field of fine chemicals.

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