KR20130106517A - Titanium dioxide powder and preparation method thereof - Google Patents

Abstract

PURPOSE: Titanium dioxide powder is provided to block ultraviolet A and B at the same time, and to remove the harmfulness to human body by removing titanium dioxide with the particle diameter smaller than 100 nm. CONSTITUTION: A production method of titanium dioxide powder comprises the following steps: mixing 1 part by weight of titanium dioxide powder with the single particle diameter of 5-300 nm with 5-50 parts by weight of water and 5-50 parts by weight of alcohol to obtain a reactant; stirring the reactant with 0.01-0.5 parts by weight of polymer coagulant; adjusting the pH of the reactant from the previous step into 10-12, and increasing the reaction temperature of the reactant to 55°C before stirring; adding 0.1-10 parts by weight of silicon alkoxide to the reactant from the previous step, and increasing the temperature to 60-65°C before stirring; coating the reactant from the previous step; and dehydrating and drying the reactant from the previous step, and removing titanium dioxide particles with the particle diameter smaller than 100 nm.

Description

Titanium dioxide powder and its manufacturing method {TITANIUM DIOXIDE POWDER AND PREPARATION METHOD THEREOF}

The present invention relates to a titanium dioxide powder and a method for manufacturing the same, and more particularly, since the particle diameter of a single particle exceeds 100 nm, it contains a large amount of titanium dioxide powder without any concern for human hazards due to particle size. It has a wide range of UV blocking areas not only in the UV B area but also in the UV A area, and also shows a significantly improved feeling compared to the conventional nano-sized ultrafine titanium dioxide, which can be useful for cosmetics used for UV protection. It relates to a titanium dioxide powder and a preparation method thereof.

Nano-size ultra-fine titanium dioxide powder has been widely used as a raw material for sunscreen cosmetics due to its high coverage and excellent UV protection and safety. However, the ultrafine titanium dioxide powder, which is used as a cosmetic raw material, exhibits a strong UV blocking ability in the ultraviolet B region, and a relatively weak UV blocking ability in the ultraviolet A region. The controversy is not over.

Thus, in order to supplement the blocking ability to the ultraviolet A region, a zinc oxide / titanium dioxide composite particle is used by using a zinc oxide powder having excellent blocking ability in the ultraviolet A region but low UV blocking ability in the ultraviolet B region. It has been used in the cosmetic composition for sun protection, but the zinc oxide has a disadvantage in that the feeling of use when applied to the cosmetic and the use is limited in Europe.

Therefore, the object of the present invention is that since the particle diameter of a single particle is greater than 100 nm, there is no concern about the harmful effects of the human body due to the particle size, and has a wide range of ultraviolet blocking regions not only in the ultraviolet B region but also in the ultraviolet A region, thereby providing ultraviolet protection. It is to provide a titanium dioxide powder and a method for producing the same that can be usefully used in cosmetics used for the purpose.

In addition, another object of the present invention is to provide a dispersion containing the titanium dioxide powder, and a sunscreen composition exhibiting excellent usability and ultraviolet ray blocking ability compared to conventional nano-sized ultrafine titanium dioxide.

In order to achieve the above object,

(1) preparing a reactant by mixing water and alcohols at 5-50 parts by weight and 5-50 parts by weight with respect to 1 part by weight of titanium dioxide powder having a single particle diameter of 5-300 nm;

(2) adding a polymer flocculant to the reactant in an amount of 0.01 to 0.5 parts by weight based on 1 part by weight of the titanium dioxide and stirring the reactant;

(3) adjusting the pH of the reactant of step (2) to 10 to 12 and raising the reaction temperature to 55 ° C and stirring;

(4) 0.1-10 parts of silicon alkoxide to 1 part by weight of the titanium dioxide in the reactant of step (3) Putting in an amount of parts by weight and raising the temperature to 60-65 ° C. and stirring;

(5) performing a coating for imparting hydrophobicity to the reactants of step (4); And

(6) dehydrating and drying the reactant of step (5) and removing titanium dioxide particles having a single particle diameter of 100 nm or less;

It provides a method for producing a titanium dioxide powder comprising a.

The present invention also provides a titanium dioxide powder produced by the above production method.

The present invention also provides a dispersion and a sunscreen composition comprising the titanium dioxide powder produced by the above production method.

Titanium dioxide powder according to the present invention, unlike the ultra-fine nano-sized titanium dioxide used for UV protection in conventional cosmetics, since the particle diameter of the single particles are all more than 100 nm, there is no concern about the human body harmfulness of the nanoparticles In addition, when applying cosmetics, both the Sun Protection Factor (SPF) and Protection Factor for UVA (PFA) are high, which can simultaneously block ultraviolet rays A and B. In addition, the content of titanium dioxide powder is higher than that of the conventional sunscreen cosmetics, so the UV protection ability is excellent, and when applied as a cosmetic composition, the effect of silica agglomerated in multiple layers on the surface of titanium dioxide improves the stiff feeling unique to titanium dioxide, thereby providing a soft feeling. Indicates.

1 to 3 is a graph showing the results of measuring the SPF and PFA of the cosmetic composition of Example 3 (Fig. 1) and Comparative Examples 1 (Fig. 2) and 2 (Fig. 3) according to the present invention.
4 to 6 are photographs showing the results of measuring in vivo SPF of the cosmetic compositions of Example 3 and Comparative Examples 1 and 2 according to the present invention.
Figure 7 is a photograph measuring the turbidity of the cosmetic composition of Example 3 and Comparative Example 1 according to the present invention.
8 is a graph showing the results of measuring the UV transmittance of the cosmetic preparation prepared in Example 3 and Comparative Example 1.
Figure 9a is a graph showing the results of measuring the volume% of the total particles of the titanium dioxide powder of Example 3 according to the present invention.
9B is a graph showing the results of observing the presence or absence of particles having a particle diameter of 100 nm or less for the titanium dioxide powder of Example 3 according to the present invention.

As used herein, the term "powder" refers to a particle group consisting of one or more particles, and the term "titanium dioxide powder" in the present invention refers to a particle group consisting of one or more titanium dioxide particles.

In addition, in this specification, the "single particle diameter" means the particle diameter when it measured using the laser diffraction particle size analyzer (MASTER SIZER 2000, the Malvern company make) with respect to the single particle | grain which comprises the said titanium dioxide powder. do.

As used herein, "alkyl" refers to an alkyl group having 1 to 20 carbon atoms, and specific examples thereof include methyl, ethyl, isopropyl, and the like, but are not limited thereto.

The present invention has no concern for human hazards through the process of removing particles having a particle diameter of 100 nm or less and has a high titanium dioxide content, and has a wide range of ultraviolet blocking regions not only in the ultraviolet B region but also in the ultraviolet A region. Compared with the markedly improved feeling of use, it is characterized in that the production of titanium dioxide powder having a single particle diameter of more than 100 nm all can be useful in cosmetics used for the purpose of blocking UV rays.

That is, the manufacturing method according to the present invention

(1) preparing a reactant by mixing water and alcohols at 5-50 parts by weight and 5-50 parts by weight with respect to 1 part by weight of titanium dioxide powder having a single particle diameter of 5-300 nm;

(2) adding a polymer flocculant to the reactant in an amount of 0.01 to 0.5 parts by weight based on 1 part by weight of the titanium dioxide and stirring the reactant;

(3) adjusting the pH of the reactant of step (2) to 10 to 12 and raising the reaction temperature to 55 ° C and stirring;

(4) Silicon alkoxide is added to the reactant of step (3) based on 1 part by weight of the titanium dioxide. 0.1-10 Putting in an amount of parts by weight and raising the temperature to 60-65 ° C. and stirring;

(5) performing a coating for imparting hydrophobicity to the reactants of step (4); And

(6) dehydrating and drying the reactant of step (5) and removing titanium dioxide particles having a single particle diameter of 100 nm or less;

And a control unit.

Hereinafter, the present invention will be described in more detail.

(1) reactant preparation

This step is to prepare a reactant by mixing nano-sized titanium dioxide powder with water and alcohols.

The nano-sized titanium dioxide may be used as an inorganic UV blocking material, a conventional titanium dioxide used in the art for UV protection, preferably a particle size of 5-300 nm, preferably 20-50 use nm.

The water may be stable water, distilled water and the like when applied to the human skin.

The alcohol may be a low alcohol having 1 to 5 carbon atoms, preferably ethanol, methanol, isopropyl alcohol, and the like.

When the nano-sized titanium dioxide powder is mixed with water and alcohol, it is important to adjust the addition ratio together with the silicon alkoxide added in the subsequent step. Preferably, 5-50 parts by weight and 5-50 parts by weight of water and alcohol are used with respect to 1 part by weight of the nano-sized titanium dioxide, and more preferably 10 parts by weight and 12 parts by weight, respectively. good.

The reason why the mixing ratio is important when preparing the reactants as described above is that, when the concentration of water and alcohol is appropriate, silica particles in short distribution can be obtained when silica particles are produced through hydrolysis of silicon alkoxide in a subsequent process, and as a result, This is because the silica particles are evenly surfaced in multiple layers for each particle of nano-sized titanium dioxide, which is an important parameter for removing particles having a single particle diameter of 100 nm or less.

(2) Polymer coagulant input

This step is a step of adding the polymer flocculant to the reactant of step (1).

In detail, a polymer coagulant, an anionic, cationic or nonionic polymer is added to the reactant of step (1), and it is not particularly limited as long as titanium dioxide can be aggregated. Preference is given to stirring and stirring for 2 hours. The polymer coagulant preferably has a molecular weight of 1,000,000 to 20,000,000, an aqueous solution viscosity of 50 to 300, and a pH of 6 to 9, more preferably a molecular weight of 15,000,000 to 17,000,000, an aqueous solution viscosity of 170 to 220, and a pH It is preferable that it is a moderate anionic polymer flocculant which is 6-8.

The anionic polymer flocculant is preferably used in an amount of 0.01 to 0.5 parts by weight based on 1 part by weight of the nano-sized titanium dioxide.

(3) pH and temperature control

This step is to adjust the pH and temperature of the reactants of step (2) before the addition of the silicon alkoxide in the subsequent process.

Specifically, it is preferable to use the basic compound in the amount of the reactant of step (2) in an amount such that pH is 10-12, preferably 10, and the basic compound is not particularly limited as long as it shows basicity. Preferably, a hydroxide of an alkali metal such as NaOH, KOH, or NH ₄ OH may be used, and the temperature of the reactant may be increased to 55 to 60 ° C. and stirred.

(4) multilayer surface treatment of silica particles on titanium dioxide

In this step, the silicon alkoxide is added to the reactant of step (3) to hydrolyze the silicon alkoxide, thereby multi-coating silica particles on the surface of the titanium dioxide particles.

Specifically, when silicon alkoxide is added, silica particles are generated by a hydrolysis reaction, and the silica particles are evenly surface-treated in a multi-layer on nano-sized titanium dioxide.

As the silicon alkoxide, tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), or the like may be used, and a commercially available basic colloidal silica sol may also be used.

The silicon alkoxide is preferably used in an amount of 0.1-10 parts by weight, more preferably 0.5-0.7, based on 1 part by weight of the nano-sized titanium dioxide. It is good to be used in parts by weight.

Although the silicon alkoxide injection method is not particularly limited, it is preferable to use an aerosol, a dropping method, or the like in that the silicon alkoxide injection rate is appropriately adjusted to obtain a short distribution of silica particles.

The faster the silicon alkoxide injection rate is, the lower the induction time of the silica particles is. As a result, the concentration of the silicon alkoxide which cannot be converted into silica in the reactant increases, making it difficult to obtain silica particles having a short distribution. Therefore, the addition of the silicon alkoxide should be made over a long time, preferably it is added over a period of 1 to 10 hours at a rate of 0.01 to 0.5% by weight relative to 100% by weight of the total amount of silicon alkoxide.

After the addition, it is preferable to stir for 8 to 24 hours while maintaining the reaction temperature at 60 to 65 ℃.

(5) coating for imparting hydrophobicity

In this step, the silica surface-treated titanium dioxide powder obtained as a result of the above step (4) is substituted with alkylsilanes and aminosilanes having 1 to 20 carbon atoms in order to make the silica-treated titanium dioxide powder lipophilic and have a smooth feeling. Silane-based compounds such as TES (triethoxysilane) and Z6020 silane (Dow Corning); Silicone oils such as dimethicone and methicone; Or fatty acids such as stearic acid; ester oils; An optional step of surface treatment with one or more surface treatment compounds such as lauroyl lysine.

In detail, the surface treatment compound is preferably surface treated at 0.5-20% by weight based on the total weight of the silica surface treated titanium dioxide.

(6) dehydration, drying and sieving

This step is a step of removing titanium dioxide particles having a single particle diameter of 100 nm or less after dehydration and drying of the reactant obtained as a result of step (5). As a method of removing titanium dioxide particles having a single particle diameter of 100 nm or less, a method of passing an air classifier or a sieve filter may be used.

Specifically, the reactant obtained as a result of the step (5) is dehydrated in a slurry state using a centrifugal dehydrator, etc., and then the precipitate is dispersed in water again and the pH is adjusted to 7 to 8, which is then dehydrated again. The precipitate is obtained, and the precipitate is dried using a vacuum drier or the like at 80-120 ° C. so as to have a water content of 2.0 wt% or less. The dried powder is treated with an atomizer and passed through a sieve of 100 to 300 mesh to remove powder having a particle size of over size, for example, micrometers (tens of micrometers), Passing through a classifier or sieve filter removes titanium dioxide particles having a single particle diameter of 100 nm or less contained in the powder.

The silica surface-treated titanium dioxide powder prepared by the above production method has a single particle diameter of more than 100 nm, preferably 300 nm or more and 10 μm or less. Accordingly, there is no concern about the human harmfulness of the nanoparticles, and it has a wide range of UV blocking regions not only in the ultraviolet B region but also in the ultraviolet A region, and also shows a significantly improved feeling compared to the conventional nano-sized ultrafine titanium dioxide, According to the silica surface-treated titanium dioxide can be usefully used for the purpose of UV protection, for example can be used in cosmetics.

In another aspect, the present invention provides a dispersion containing a silica surface treatment titanium dioxide powder prepared by the above method. The dispersion may include a residual amount of the dispersion medium in 60 to 70% by weight of the silica surface treatment titanium dioxide powder produced by the method according to the present invention, the dispersion medium can be used by appropriately selecting a dispersion medium commonly used Of course. In addition, the dispersion according to the present invention includes a content of titanium dioxide powder in the range of 60 to 70% by weight, preferably 62 to 67% by weight, compared to the content of titanium dioxide is less than 60% by weight of the dispersion used in the conventional sunscreen When applied to ultraviolet cosmetics as compared to the conventional dispersion can exhibit a more excellent UV blocking effect.

In another aspect, the present invention provides a sunscreen composition comprising a silica surface treatment titanium dioxide powder prepared by the above method.

In this case, when the sunscreen composition is used as a cosmetic, the silica surface treatment titanium dioxide is arbitrarily controllable, and considering the sunscreen effect, skin irritation, miscibility with other sunscreen ingredients and formulation formation, It is preferably included in the amount of 0.1-20% by weight relative to the total weight of the sunscreen composition.

In addition, the sunscreen composition may include components commonly used in cosmetic compositions such as antioxidants, stabilizers, solubilizers, pigments, fragrances in addition to silica surface treatment titanium dioxide powder.

The sunscreen composition according to the present invention can contain a larger amount of titanium dioxide powder by using the titanium dioxide powder according to the present invention, compared to the conventional sunscreen composition, it is more excellent in the sunscreen ability.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Example 1

After putting 6000 g of distilled water and 6000 g of ethanol into a 20 L reaction tube, 700 g of titanium dioxide (X205, manufactured by KEMIRA) having an average particle diameter of 20 nm as an inorganic ultraviolet ray shielding material was added thereto, and the suspension was carried out at 20 ° C. Stir for 30 minutes at 100 rpm until it becomes.

1 g of anionic polymer flocculant (Aronfurk A101, Sejin, Korea) was added to the suspension, followed by stirring for 2 hours.

Ammonia (NH ₄ OH) was added until the pH of the reactant was 10.0 to 12.0, and the reaction temperature was raised to 55 ° C., followed by stirring at a speed of 150 rpm for 30 minutes.

Then, 280 g of tetraethoxysilane (TEOS) was dripped over about 3 hours at the speed of 1.6 g / min, stirring at 250 rpm. After the addition of the tetraethoxysilane was completed, the temperature of the reaction was maintained at 60 to 65 ℃ or more, left for 8 hours, then stirred at a speed of 100 rpm for 24 hours, the silica particles surface-treated in a multilayer Titanium was produced.

To the resultant reaction, 70 g of TES (triethoxysilane) and 0.7 g of Z6020 silane (Dow Corning) were added and stirred at a speed of 200 rpm at 65 ° C. for 24 hours.

The reaction was dehydrated using a centrifugal dehydrator, and then the collected precipitate was dispersed in 2000 g of water, washed with HCl, adjusting the pH to 7-8, and dewatered secondly using a centrifugal dehydrator. The collected precipitate was dried at 100 DEG C for 30 hours so that the water content in the powder was 2.0% by weight or less, then treated with an atomizer and passed through an airflow classifier or a sieve filter (200 mesh) in the powder. Titanium dioxide particles having a single particle diameter of 100 nm or less and several tens of um of large particles were removed.

As a result of checking the% of each particle of the prepared silica surface-treated titanium dioxide powder by using a laser diffraction particle size analyzer, it was confirmed that the size of each single particle was more than 100 nm.

[Example 2]

3 kg of emulsifier PHS-8 was added to 37 kg of C _12-15 alkyl benzoate, followed by primary stirring for about 10 minutes in a stirrer. 60 kg of titanium dioxide powder prepared in Example 1 was added thereto, followed by secondary stirring in a stirrer for about 10 minutes, followed by 3 Disperse over time.

[Example 3]

A cosmetic containing 20.0 wt% of the titanium dioxide dispersion prepared in Example 2 was prepared by mixing according to the composition shown in Table 1 below.

ingredient content Distilled water 50.15 P.G 4.0 Carbopol 940 2% 8.0 Arlacel 60 0.5 Tween 60 2.7 Kalcohol 8670 1.0 TCG-M 8.0 Myristic acid 2.5 Arlacel 165 2.0 TEA 0.2 Phenoxyethanol 0.8 Fragrance 0.15 Dispersion of Example 2 20.0

Comparative Example 1

In Example 3, a cosmetic was prepared in the same manner as in Example 3, except that Sunveil XT-100 of Croda was used instead of the titanium dioxide dispersion prepared in Example 2.

Comparative Example 2

In Example 3, a cosmetic was prepared in the same manner as in Example 3, except that Sunveil CT-100 of Croda was used instead of the titanium dioxide dispersion prepared in Example 2.

[Test Example 1]

The titanium dioxide dispersion of Example 2 and Crove's Sunveil XT-100 used in Comparative Example 1 according to the present invention by using an optical device (Optometrics 290, Optoometrics, Inc.) The PFA and the critical wavelength, which are the degree of blocking of SPF and ultraviolet rays A, were measured 7 times, and the average values thereof were expressed. The results are shown in Table 2 below.

result Example 2 Comparative Example 1 SPF 33.87 27.66 PFA 13.8 13.59 SPF / PFA 2.45 2.04 Critical wavelength 372 378.4

As shown in Table 2, the dispersion containing the titanium dioxide powder according to the present invention showed excellent SPF and PFA compared to the conventional UV protection dispersion, the SPF / PFA ratio is 3 or less and the critical wavelength is 370 nm As such, it can be seen that it has excellent performance that satisfies the EU's UVA Directive.

[Test Example 2]

For the cosmetics prepared in Example 3 and Comparative Examples 1 and 2, the same experiment as Test Example 1 was repeated and the results are shown in Table 3 and FIGS. 1 to 3.

In addition, the panel was measured in vivo SPF using a Multi-port Solar simulator 601-300W (Solar Light, USA) for 20 people, the results are shown in Table 3 and Figures 4 to 6 below.

result Example 2 Comparative Example 1 Comparative Example 2 in vivo SPF 25 21 16 in vitro SPF 33.29 25.62 10.95 in vitro PFA 15.47 15.05 3.6 in vivo SPF / in vitro PFA 1.62 1.40 4.44 Critical wavelength 377 381 363.3

As shown in Table 3, the cosmetic containing titanium dioxide powder according to the present invention showed a high SPF and PFA compared to Comparative Examples 1 and 2, the in vivo SPF / PFA ratio is 3 or less and the critical wavelength is 370 nm It can be seen that it has an excellent performance that satisfies the EU's UVA Directive.

[Test Example 3]

The turbidity was measured using a NIPPON DENSHOKU COLOR METER ZE 2000 after applying 0.1 g of the cosmetics prepared in Example 3 and Comparative Example 1 and then applying a 12.5 μm thickness using a baker applicator. The results are shown in FIG.

As shown in Figure 7, it can be seen that the cosmetic composition containing the titanium dioxide powder according to the present invention is less transparent than the comparative example 1 has a lower turbidity.

[Test Example 4]

The UV transmittance of the cosmetics prepared in Example 3 and Comparative Example 1 was measured in the UV wavelength range of 260 nm to 400 nm using a UV / VIS spectrometer and is shown in FIG. 8.

As shown in FIG. 8, the cosmetic containing titanium dioxide powder according to the present invention exhibited UV transmittance of about 55%, whereas the cosmetic of Comparative Example 1 exhibited UV transmittance of about 35%, the cosmetic according to the present invention. It can be seen that the UV transmission ability of the is better.

[Test Example 5]

The cosmetic of Example 3 was subjected to particle size analysis using a laser diffraction particle size analyzer (LASER Particle Size Analyser, manufactured by MALVERN), and the total particle size and single particle size were measured, respectively. At this time, the size of the whole particles was measured in volume% (volume%), and in order to confirm the existence of a single particle of 100 nm or less, it is not the volume% but the number (number%) representing the actual number of particles. Measured. The results are shown in Figures 9a and 9b.

As shown in Figure 9a and 9b, in the cosmetic of Example 3 comprising a titanium dioxide powder according to the present invention particles having a diameter of 100 nm or less in both the volume% of the total particles and the measurement of the number of percent of single particles Was not observed at all.

Claims (11)

(1) preparing a reactant by mixing 5-50 parts by weight of water and alcohols with respect to 1 part by weight of titanium dioxide powder having a single particle diameter of 5-300 nm;
(2) adding a polymer flocculant to the reactant in an amount of 0.01 to 0.5 parts by weight based on 1 part by weight of the titanium dioxide and stirring the reactant;
(3) adjusting the pH of the reactant of step (2) to 10 to 12 and raising the reaction temperature to 55 ° C and stirring;
(4) 0.1-10 parts of silicon alkoxide to 1 part by weight of the titanium dioxide in the reactant of step (3) Adding in parts by weight and raising the temperature to 60-65 ° C. and stirring;
(5) performing a coating for imparting hydrophobicity to the reactants of step (4); And
(6) dehydrating and drying the reactant of step (5) and removing titanium dioxide particles having a single particle diameter of 100 nm or less;
Method for producing a titanium dioxide powder comprising a. The method of claim 1,
Method for producing a titanium dioxide powder, characterized in that the molecular weight of the polymer flocculant is 1,000,000 to 20,000,000. The method of claim 1,
In step (3), the pH is adjusted to a basic compound selected from the group consisting of NH ₄ OH, NaOH and mixtures thereof. The method of claim 1,
In the step (4), the silicon alkoxide is selected from the group consisting of tetramethoxysilane, tetraethoxysilane and mixtures thereof. The method of claim 1,
Method of producing a titanium dioxide powder, characterized in that the silicon alkoxide addition step in the step (5) is carried out by aerosol or dropping method. The method of claim 1,
The hydrophobic treatment process in the step (6), the silica surface treatment titanium dioxide powder is silane-based compound, silicone oil, fatty acid, ester-based oil, lauroyl lysine and A method for producing a titanium dioxide powder, characterized by performing surface treatment with a surface treatment compound from the group consisting of these mixtures. The method according to claim 6,
The surface treatment compound is a method for producing titanium dioxide powder, characterized in that the surface treatment is 0.5-20% by weight relative to the total weight of the titanium dioxide surface-treated silica. Titanium dioxide powder comprising particles having a single particle diameter of at least 100 nm, which is produced by the process according to any one of claims 1 to 7. Titanium dioxide powder according to claim 8; And
Distribution dealer
Dispersion comprising a. 10. The method of claim 9,
60-70 wt% of the titanium dioxide powder; And
Residual amount of dispersion medium
Dispersion comprising a. A sunscreen cosmetic composition comprising the titanium dioxide powder of claim 8.

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