Titanium dioxide aqueous dispersion as well as preparation method and application thereof

Abstract

The invention provides a titanium dioxide aqueous dispersion as well as a preparation method and application thereof, and belongs to the technical field of cosmetics. The titanium dioxide aqueous dispersion is prepared from the following components in parts by weight: 60 to 75 parts of nano titanium dioxide, 10 to 25 parts of polyhydric alcohol, 1 to 5 parts of polysaccharide polymer and 10 to 20 parts of water, wherein the polysaccharide polymer comprises propylene glycol alginate. According to the invention, the polyol and the polysaccharide polymer are added into the titanium dioxide aqueous dispersion, so that the dispersity of the nano titanium dioxide is improved, and the stability of cosmetics containing the nano titanium dioxide aqueous dispersion, especially the stability, skin feeling and sunscreen effect of oil-in-water sunscreen products, is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of cosmetics, and specifically relates to a titanium dioxide aqueous dispersion and a preparation method and application thereof. Background Art

[0002] As an inorganic sunscreen, nano titanium dioxide not only has the ability to absorb ultraviolet rays, but also can scatter and refract ultraviolet rays. Nano titanium dioxide has a shielding effect on ultraviolet rays of all bands. At the same time, titanium dioxide has excellent light stability and thermal stability, and is non-toxic and odorless. Therefore, it is widely used in sunscreen skin care products.

[0003] However, the following problems may occur during the use of nano titanium dioxide: for example, adding a high dose of nano titanium dioxide to oil-in-water sunscreen products will cause the oil-in-water sunscreen products to appear fake white during the application process, and nano titanium dioxide has a high surface energy, and it is easy to aggregate powders in cosmetics, resulting in a rough surface and poor stability of the oil-in-water sunscreen products. In order to improve this phenomenon, a surface modifier is usually used to coat the titanium dioxide to improve the dispersibility of nano titanium dioxide in water and oil media, so that titanium dioxide can be evenly dispersed in water and oil media. The pH value of oil-in-water sunscreen products is 6-7. In a weakly acidic environment, the negative charge on the surface of the surface-modified titanium dioxide is reduced, resulting in a thinning of the double electric layer, a reduction in the repulsion between particles, and agglomeration of the surface-modified titanium dioxide. As time goes by, the aggregation degree of the surface-modified titanium dioxide increases, resulting in the instability of the oil-in-water sunscreen products such as rough surface and jelly-like. Summary of the invention

[0004] The purpose of the present disclosure is to overcome the deficiencies of the prior art and provide a titanium dioxide aqueous dispersion and a preparation method and application thereof, wherein the titanium dioxide aqueous dispersion has high dispersibility.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present disclosure is as follows: The present invention provides a titanium dioxide aqueous dispersion, comprising the following components in parts by weight: 60-75 parts of nano titanium dioxide, 10-25 parts of polyols, 1-5 parts of polysaccharide polymers, and 10-20 parts of water; wherein the polysaccharide polymer includes propylene glycol alginate.

[0006] In some embodiments, the polysaccharide polymer further comprises at least one of Chondrus crispus extract, sodium carrageenan, acacia gum, karaya gum, and carboxymethyl chitosan.

[0007] In some embodiments, the polysaccharide polymer is propylene glycol alginate and Chondrus crispus extract, and the mass ratio of propylene glycol alginate to Chondrus crispus extract is 7:1-1:3.

[0008] In some embodiments, the polyol is at least one of glycerol, ethylene glycol, propylene glycol, butylene glycol, dipropylene glycol, pentylene glycol, hexylene glycol, and methylpropylene glycol.

[0009] In some embodiments, the polyol is dipropylene glycol and methyl propylene glycol, and the mass ratio of dipropylene glycol to methyl propylene glycol is 1.5-4.

[0010] In some embodiments, the nano-titanium dioxide is modified by a surface treatment agent, and the surface treatment agent is at least one of a silane coupling agent, hydrogenated polydimethylsiloxane, silicon dioxide, aluminum hydroxide, and amino acid.

[0011] In the second aspect, a method for preparing the titanium dioxide aqueous dispersion is provided, comprising the following steps: after uniformly mixing the polyol and the polysaccharide polymer, adding water, heating to 60-80°C and stirring until transparent, then adding nano-titanium dioxide, homogenizing at a speed of 5000-8000 r / min for 3-5 minutes, stirring and cooling to room temperature to obtain a titanium dioxide aqueous dispersion.

[0012] In a third aspect, a use of the titanium dioxide dispersion in cosmetics is provided.

[0013] In a fourth aspect, a cosmetic is provided, comprising the titanium dioxide aqueous dispersion, wherein the mass percentage of the titanium dioxide aqueous dispersion in the cosmetic is 6-15%.

[0014] In some embodiments, the cosmetic is a sunscreen lotion, and the sunscreen lotion includes the following components in percentage by weight: 6-15% titanium dioxide aqueous dispersion, 5-15% organic sunscreen, 5-30% oil, 0.5-5% emulsifier, 0.1-5% skin conditioner, 0.1-20% moisturizer, 0.05-5% rheology regulator, 0.05-3% antioxidant, 0.1-0.6% preservative, 0.05-5% pH adjuster, 0.01-1% fragrance, and the remainder water.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: in the present invention, polyols and polysaccharide polymers are added to the titanium dioxide aqueous dispersion, and the hydroxyl groups on the surface of nano-titanium dioxide interact with the hydroxyl groups of the polysaccharide polymer through van der Waals forces, so that the nano-titanium dioxide is adsorbed on the surface of the polysaccharide polymer, the repulsion between the nano-titanium dioxide particles is enhanced, and the aggregation of the nano-titanium dioxide is reduced; in addition, the polyols and the polysaccharide polymers form supramolecules that interact with each other through hydrogen bonds and van der Waals forces in the presence of water, which significantly increases the repulsion between the nano-titanium dioxide particles and further increases the dispersibility of the nano-titanium dioxide, thereby improving the stability of cosmetics containing the nano-titanium dioxide aqueous dispersion, especially the stability, skin feel and sunscreen effect of water-in-oil sunscreen products. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a diagram showing the dispersion effect of the titanium dioxide aqueous dispersion in water according to Example 1 of the present invention;

[0017] Figure 2 This is a diagram showing the dispersion effect of titanium dioxide aqueous dispersion in oil according to Example 1 of the present invention;

[0018] Figure 3 This is a diagram showing the appearance stability of the titanium dioxide aqueous dispersion in Example 1 of the present invention;

[0019] Figure 4 This is a diagram showing the appearance stability of the titanium dioxide aqueous dispersion of Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0020] In order to facilitate understanding of the present disclosure, the present disclosure will be described more fully below. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present disclosure more thorough and comprehensive.

[0021] As used herein:

[0022] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0023] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0024] When amount, concentration or other value or parameter is represented by range, preferred range or a series of upper preferred value and lower preferred value, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value and any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when disclosing range "1-5", described range should be interpreted as including range "1-4", "1-3", "1-2", "1-2 and 4-5", "1-3 and 5" etc. When numerical range is described in this article, unless otherwise stated, the range is intended to include its end value and all integers and fractions within the range.

[0025] In these examples, parts and percentages are by mass unless otherwise indicated.

[0026] "Parts by mass" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass of all components is not limited to 100 parts.

[0027] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0028] In order to solve the problem in the prior art that high-dose nano titanium dioxide is easily aggregated in oil-in-water sunscreen products and leads to reduced stability of the oil-in-water sunscreen products.

[0029] The invention provides a titanium dioxide aqueous dispersion, comprising the following components in parts by weight: 60-75 parts of nano titanium dioxide, 10-25 parts of polyol, 1-5 parts of polysaccharide polymer, and 10-20 parts of water; wherein the polysaccharide polymer comprises propylene glycol alginate.

[0030] For example, in different embodiments, the weight portion of the nano titanium dioxide may be, but is not limited to, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75 parts;

[0031] For example, in different embodiments, the weight parts of the polyol may be, but are not limited to, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 25 parts;

[0032] For example, in different embodiments, the weight proportion of the polysaccharide polymer may be, but is not limited to, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts;

[0033] For example, in different embodiments, the weight proportion of the water may be, but is not limited to, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, or 20 parts.

[0034] The present invention adds polyols and polysaccharide polymers to a titanium dioxide aqueous dispersion, and the hydroxyl groups on the surface of nano titanium dioxide interact with the hydroxyl groups of the polysaccharide polymer through van der Waals force, so that the nano titanium dioxide is adsorbed on the surface of the polysaccharide polymer, the repulsion between the nano titanium dioxide particles is enhanced, and the aggregation of the nano titanium dioxide is reduced. In addition, the polyols and the polysaccharide polymer form supramolecules that interact with each other through hydrogen bonds and van der Waals forces in the presence of water, which significantly increases the repulsion between the nano titanium dioxide particles and further increases the dispersibility of the nano titanium dioxide, thereby improving the stability of cosmetics containing the nano titanium dioxide aqueous dispersion, especially the stability, skin feel and sunscreen effect of water-in-oil sunscreen products.

[0035] In some embodiments, the polysaccharide polymer further comprises at least one of Chondrus crispus extract, sodium carrageenan, acacia gum, karaya gum, and carboxymethyl chitosan.

[0036] In the present invention, when the polysaccharide polymer further comprises the above components, the dispersibility of the titanium dioxide aqueous dispersion and the stability and sunscreen effect of the oil-in-water sunscreen product can be further improved.

[0037] In some embodiments, the polysaccharide polymer is propylene glycol alginate and Chondrus crispus extract, and the mass ratio of propylene glycol alginate and Chondrus crispus extract is 7:1-1:3, for example but not limited to 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3.

[0038] In the present invention, when the polysaccharide polymer is propylene glycol alginate and Chondrus crispus extract, the dispersibility of the titanium dioxide aqueous dispersion and the stability and sunscreen effect of the oil-in-water sunscreen product are better.

[0039] In some embodiments, the polyol is at least one of glycerol, ethylene glycol, propylene glycol, butylene glycol, dipropylene glycol, pentylene glycol, hexylene glycol, and methylpropylene glycol.

[0040] In some embodiments, the polyol is dipropylene glycol and methyl propylene glycol, and the mass ratio of dipropylene glycol to methyl propylene glycol is 1.5-4, for example, but not limited to 1.5, 2, 2.5, 3, 3.5, 4.

[0041] In the present invention, when the polyol is dipropylene glycol and methyl propylene glycol, the dispersibility of the titanium dioxide aqueous dispersion and the stability and sunscreen effect of the oil-in-water sunscreen product are better.

[0042] In some embodiments, the nano-titanium dioxide is modified by a surface treatment agent, and the surface treatment agent is at least one of a silane coupling agent, hydrogenated polydimethylsiloxane, silicon dioxide, aluminum hydroxide, and amino acid.

[0043] The surface modifier performs surface coating treatment on titanium dioxide, which can improve the dispersibility of nano titanium dioxide in water and oil media, and can make titanium dioxide evenly dispersed in water and oil media.

[0044] The shape of the titanium dioxide particles is not particularly limited, and particles having any shape, such as spherical particles, rod-shaped particles, needle-shaped particles, spindle-shaped particles, and plate-shaped particles, can be used. For the average primary particle size of particles having a shape other than a sphere, in the case of rod-shaped particles, needle-shaped particles, and spindle-shaped particles, the average primary particle size is defined by the average value of the length of the minor axis side, and in the case of plate-shaped particles, the average primary particle size is defined by the average value of the length of the diagonal line on the surface.

[0045] The ratio of the major axis diameter to the minor axis diameter of the titanium dioxide particles is called the aspect ratio. The aspect ratio is preferably 3 or less, and more preferably 1 to 2. The aspect ratio of the titanium dioxide particles is calculated as the average value of the major axis diameter to the minor axis diameter of 200 particles randomly selected under an electron microscope.

[0046] The crystal structure of the titanium dioxide particles is not particularly limited, and for example, anatase type, rutile type or brookite type may be used. From the viewpoint of suppressing photocatalytic activity, rutile type is preferably used. In addition to titanium dioxide (TiO2), the titanium dioxide particles may also be a compound represented by metatitanate (TiO2·nH2O) and orthotitanate (Ti(OH)4).

[0047] Titanium dioxide particles can be prepared by a variety of well-known methods. As a method for preparing the above-mentioned titanium dioxide particles with a smaller average primary particle size, for example, the following method can be adopted: a method in which a titanium tetrachloride aqueous solution is hydrolyzed by neutralization using an alkali and the obtained hydrous titanium dioxide is calcined (this is also referred to as a "calcination method" in this application), and a method in which a titanium tetrachloride aqueous solution is hydrolyzed by neutralization using an alkali, the obtained hydrous titanium dioxide is heat-treated with sodium hydroxide, and the obtained reaction product is heated and matured with an acid (this is also referred to as a "wet method" in this application). In general, spherical titanium dioxide particles can be obtained by the above calcination method, and spindle-shaped titanium dioxide particles can be obtained by the above wet method. In addition, rutile titanium dioxide particles can be obtained by calcination and wet method. In addition, the titanium dioxide particles obtained by the calcination method have an aspect ratio of about 3 or less. Preferably, spherical particles with an aspect ratio of 1 to 2 can be obtained.

[0048] In the spherical titanium dioxide particles obtained by the calcination method, the crystallinity is increased by the calcination, and thus the photocatalytic activity is highly suppressed. Therefore, in cosmetics, it is preferable to use the spherical titanium dioxide particles obtained by the calcination method.

[0049] The average particle size of nano titanium dioxide is 10-40 nm, for example, it can be but not limited to 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, and the testing method is GB / T 19077-2016.

[0050] In the second aspect, a method for preparing the titanium dioxide aqueous dispersion is provided, comprising the following steps: after uniformly mixing the polyol and the polysaccharide polymer, adding water, heating to 60-80°C and stirring until transparent, then adding nano-titanium dioxide, homogenizing at a speed of 5000-8000 r / min for 3-5 minutes, stirring and cooling to room temperature to obtain a titanium dioxide aqueous dispersion.

[0051] For example, in different embodiments, the homogenizing rotation speed may be, but is not limited to, 5000 r / min, 5500 r / min, 6000 r / min, 6500 r / min, 7000 r / min, 7500 r / min, or 8000 r / min.

[0052] In the present invention, the titanium dioxide aqueous dispersion prepared by the above method has better dispersibility.

[0053] In a third aspect, a use of the titanium dioxide dispersion in cosmetics is provided.

[0054] In a fourth aspect, a cosmetic is provided, comprising the titanium dioxide aqueous dispersion, wherein the mass percentage of the titanium dioxide aqueous dispersion in the cosmetic is 6-15%, for example, it can be but not limited to 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%.

[0055] The cosmetics prepared by using the titanium dioxide aqueous dispersion of the present invention can be prepared by mixing the aqueous dispersion with the optional raw materials for cosmetics. As the optional raw materials for cosmetics, components such as the following can be used: oils, surfactants, wetting agents, higher alcohols, metal ion chelating agents, natural and synthetic polymers, water-soluble and oil-soluble polymers, ultraviolet shielding agents, various extracts, colorants including pigments and organic dyes, preservatives, antioxidants, dyes, thickeners, pH regulators, spices, cooling agents, antiperspirants, fungicides, skin activators and various powders. The mixture of these components can be prepared as various forms, such as creams, pastes, sticks, emulsions.

[0056] In some embodiments, the cosmetic is a sunscreen lotion, and the sunscreen lotion includes the following components in percentage by weight: 6-15% titanium dioxide aqueous dispersion, 5-15% organic sunscreen, 5-30% oil, 0.5-5% emulsifier, 0.1-5% skin conditioner, 0.1-20% moisturizer, 0.05-5% rheology regulator, 0.05-3% antioxidant, 0.1-0.6% preservative, 0.05-5% pH adjuster, 0.01-1% fragrance, and the remainder water.

[0057] The sunscreen lotion of the present invention contains a titanium dioxide aqueous dispersion (inorganic sunscreen) and an organic sunscreen. The two different types of sunscreens are used in combination, and the high-dose titanium dioxide aqueous dispersion is contained to reduce the stimulation of the organic sunscreen to the skin, and can effectively prevent the damage of ultraviolet rays to the skin, thereby improving the sunscreen effect of the sunscreen lotion. In addition, the titanium dioxide aqueous dispersion has good dispersibility in the sunscreen lotion, can effectively reduce the aggregation of titanium dioxide, so that the sunscreen lotion does not turn white after being applied, the skin feels fresh, and has good air permeability and sunscreen effect.

[0058] For example, in different embodiments, the weight percentage of the titanium dioxide aqueous dispersion may be, but is not limited to, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%;

[0059] For example, in different embodiments, the weight percentage of the organic sunscreen agent may be, but is not limited to, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%;

[0060] For example, in different embodiments, the weight percentage of the oil may be, but is not limited to, 5%, 7%, 9%, 11%, 13%, 15%, 17%, 19%, 21%, 23%, 25%, 28%, 30%;

[0061] For example, in different embodiments, the weight percentage of the emulsifier may be, but is not limited to, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%;

[0062] For example, in different embodiments, the weight percentage of the skin conditioning agent may be, but is not limited to, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%;

[0063] For example, in different embodiments, the weight percentage of the moisturizer may be, but is not limited to, 0.1%, 1%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%;

[0064] For example, in different embodiments, the weight percentage of the rheology modifier may be, but is not limited to, 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%;

[0065] For example, in different embodiments, the weight percentage of the antioxidant may be, but is not limited to, 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%;

[0066] For example, in different embodiments, the weight percentage of the preservative may be, but is not limited to, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%;

[0067] For example, in different embodiments, the weight percentage of the pH adjuster may be, but is not limited to, 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%;

[0068] For example, in different embodiments, the weight percentage of the flavor may be, but is not limited to, 0.01%, 0.05%, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, or 1%.

[0069] For example, in different embodiments, the organic sunscreen agent is one or more of bis-ethylhexyloxyphenol methoxyphenyl triazine, butyl methoxydibenzoylmethane, diethylaminohydroxybenzoyl hexyl benzoate, diethylhexyl butyramido triazone, disodium phenyl diimidazole tetrasulfonate, ethylhexyl methoxycinnamate, ethylhexyl salicylate, ethylhexyl triazone, homosalate, isopentyl p-methoxycinnamate, methylene bis-benzotriazolyl tetramethylbutylphenol, octocrylene, and phenylbenzimidazole sulfonic acid.

[0070] For example, in different embodiments, the oil is one or more of ethylhexyl palmitate, dicaprylyl carbonate, hydrogenated polyisobutene, butylene glycol cocoate, propylheptyl caprylate, isopropyl palmitate, isostearyl isostearate, C12-13 alcohol malate, caprylic / capric triglyceride, propylene glycol dicaprylate / dicaprate, glyceryl tri(ethylhexanoate), hydrogenated polydecene, diisostearyl malate, isopentyl laurate, C12-15 alcohol benzoate, isohexadecane, coconut oil-caprylate / caprate, butyloctanol salicylate, isopropyl lauroyl sarcosine, and polydimethicone.

[0071] For example, in different embodiments, the emulsifier is one or more of potassium cetyl phosphate, cetyl phosphate, sodium stearoyl glutamate, glyceryl stearate / PEG-100 stearate, tri(laureth-4) phosphate, steareth-21, polyglyceryl-2 dipolyhydroxystearate, and polyglyceryl-3 diisostearate.

[0072] For example, in different embodiments, the skin conditioning agent is one or more of allantoin, niacinamide, panthenol, β-glucan, inositol, madecassoside, bisabolol, erythritol, and tocopherol acetate.

[0073] For example, in different embodiments, the moisturizer is one or more of glycerin, polyethylene glycol-8, betaine, trehalose, sodium polyglutamate, methyl gluceth-10, methyl gluceth-20, PPG-24-glycerol polyether-24, and PEG / PPG-17 / 6 copolymer.

[0074] For example, in different embodiments, the rheology regulator is one or more of ammonium acryloyldimethyltaurate / VP copolymer, acrylic acid (ester) copolymer, carbomer, sodium carbomer, acrylic acid (ester) / C10-30 alkyl acrylate crosspolymer, acrylic acid (ester) / behenyl alcohol polyether-25 methacrylate copolymer, acrylic acid (ester) / palmitoleyl alcohol polyether-25 acrylate copolymer, PEG-240 / HDI copolymer bis-decyltetradecyl alcohol polyether-20 ether, acrylic acid (ester) / vinyl isodecanol crosspolymer, ammonium acryloyldimethyltaurate / behenyl alcohol polyether-25 methacrylate crosspolymer, hydroxyethyl acrylate / sodium acryloyldimethyltaurate copolymer, sodium polyacrylate, hydroxyethyl cellulose, and polyacrylate crosspolymer-6.

[0075] For example, in different embodiments, the antioxidant is one or more of p-hydroxyacetophenone, tocopherol acetate, butylated hydroxytoluene, pentaerythritol tetrakis (di-tert-butyl hydroxyhydrocinnamate), and tert-butyl hydroquinone.

[0076] For example, in different embodiments, the preservative is one or more of methylparaben, phenoxyethanol, chlorphenesin, propylparaben, DMDM ​​hydantoin, and sodium benzoate.

[0077] For example, in different embodiments, the pH adjuster is one or more of triethanolamine, aminomethyl propanol, sodium hydroxide, arginine, sodium citrate, and tromethamine.

[0078] The cosmetics of the present invention can be prepared by any suitable method known in the art. For example, the cosmetics can be prepared using equipment such as a dissolving tank, an emulsifying pot, a disperser, and a delivery pump commonly used in the cosmetics field according to processes known in the art. For example, a water-soluble substance can be first put into an aqueous phase dissolving pot, and an oil-soluble substance (such as a sunscreen, grease) can be put into an oil phase dissolving pot, and the temperature of the two pots can be heated to about 80°C, respectively. For raw materials that are easy to agglomerate, they can be pre-dispersed with a disperser; such as powder-containing substances (such as zinc oxide and titanium dioxide), they can be dispersed with a suitable solvent and a dispersant and homogenized for 5-10 minutes, and the oil phase is added and homogenized again for 5-10 minutes; after homogenization is completed, the oil phase and the water phase are delivered to the emulsifying pot for homogenization and emulsification for about 5-15 minutes; after emulsification is completed, the temperature of the material body is reduced to room temperature, and optionally, flavors, preservatives, etc. are added, and the pH of the product is adjusted as needed; after the relevant test indicators are qualified, the material can be filled and discharged.

[0079] The above preparation process is merely exemplary, and those skilled in the art may increase, decrease or adjust it according to the dosage form requirements, thereby preparing various dosage forms such as spray, emulsion, gel / jelly, cream, cushion / foundation, etc.

[0080] In order to further illustrate the present invention, the titanium dioxide aqueous dispersion provided by the present invention and its preparation method and application are described in detail below in conjunction with the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.

[0081] Examples and Comparative Examples

[0082] The present invention provides a titanium dioxide aqueous dispersion according to the embodiment and comparative example. The components and weight parts of the titanium dioxide aqueous dispersion are shown in Table 1 and Table 2.

[0083] The preparation method of the titanium dioxide aqueous dispersion of the embodiment and the comparative example is as follows:

[0084] Weigh each component according to the weight parts in Table 1 and Table 2, mix the polyol and polysaccharide polymer evenly, add water, heat to 70°C and stir until transparent, then add nano titanium dioxide with an average particle size of 25 nm, homogenize at a speed of 6000 r / min for 3 minutes, homogenize 3 times in total, stir and cool to room temperature to obtain a titanium dioxide aqueous dispersion.

[0085] Table 1

[0086]

[0087] Table 2

[0088]

[0089] Application examples 1-16, comparative application examples 1-6 and blank application examples

[0090] The application examples, comparative application examples and blank application examples of the present invention provide an oil-in-water sunscreen lotion, the components (mass percentage) of the oil-in-water sunscreen lotion are shown in Table 3; wherein the titanium dioxide aqueous dispersions used in application examples 1-12 are the titanium dioxide aqueous dispersions prepared in embodiments 1-12, respectively, and the titanium dioxide aqueous dispersions used in comparative application examples 1-6 are the titanium dioxide aqueous dispersions prepared in comparative examples 1-6, respectively; the titanium dioxide aqueous dispersions used in application examples 15-16 are the titanium dioxide aqueous dispersions prepared in embodiment 1;

[0091] The preparation method of the oil-in-water sunscreen lotion of the application example, comparative application example and blank application example is:

[0092] Prepare the aqueous phase: mix water, skin conditioning agent, moisturizer, rheology regulator and preservative evenly to prepare the aqueous phase;

[0093] Prepare the oil phase: mix the oil and emulsifier evenly, stir and heat to 80-90°C to prepare the oil phase;

[0094] Preparation of emulsion: heating the oil phase and the water phase to 80-90° C. respectively, then adding the oil phase to the water phase, and performing emulsification and homogenization at a rotation speed of 5000 rpm for 3 minutes to obtain an emulsion;

[0095] Preparation of oil-in-water sunscreen lotion: cooling the emulsion to room temperature, then adding the titanium dioxide aqueous dispersion and the remaining components, stirring evenly, to obtain the oil-in-water sunscreen lotion.

[0096] Table 3

[0097]

[0098]

[0099] Effect Example 1

[0100] This effect example tests the appearance, dispersibility, pH and viscosity of the titanium dioxide aqueous dispersion obtained in the examples and comparative examples.

[0101] The specific steps are as follows:

[0102] (1) Appearance: visual inspection;

[0103] (2) Dispersibility: The titanium dioxide aqueous dispersions obtained in the examples and comparative examples were added to water and oil, respectively, stirred for 1 min, and the dispersion of the titanium dioxide aqueous dispersions was visually observed;

[0104] (3) pH value: Tested using the dilution method in accordance with the Technical Specification for Safety of Cosmetics (2015 edition).

[0105] (4) Viscosity: The test was conducted at room temperature using an IKA ROTAVISC ME-VI, 8#, 15 rpm.

[0106] (5) Appearance stability: The oil-in-water sunscreen lotion was placed at 25°C for 90 days and the appearance of the oil-in-water sunscreen lotion was visually observed.

[0107] The test results are as follows Figure 1-4 And as shown in Table 4.

[0108] Table 4

[0109]

[0110]

[0111] like Figure 1-2 As shown, visual observation of the titanium dioxide aqueous dispersions of Examples 1-14 and Comparative Examples 1-6 shows that they are all white and uniform dispersions; and are easily dispersed in water but not easily dispersed in oil.

[0112] It can be seen from the experimental data in Table 4 that the pH value of the titanium dioxide aqueous dispersion of the present invention is 5.5-6, and the viscosity is 500-1850 mPa.s.

[0113] Effect Example 2

[0114] This effect example tests the stability of the oil-in-water sunscreen lotion obtained from the application example, comparative application example and blank application example.

[0115] The specific steps are as follows:

[0116] (1) Instability index (normal temperature stability): at 25°C, using a dispersion analyzer The 651 test quantifies the dispersion by dividing the clarity by the clarity at a given separation time; the clarity quantifies the increase in transmittance (reduction in particle concentration) due to phase separation caused by sedimentation or creaming; where the instability index is a value between 0 and 1. "0" means that the particle concentration has not changed (very stable) and "1" means that the dispersion has separated (very unstable).

[0117] (2) Particle size: tested using an optical microscope.

[0118] The test results are shown in Table 5.

[0119] Table 5

[0120]

[0121] From the experimental data in Table 5, it can be seen that the instability index of the sunscreen lotion of the present invention is ≤0.17, the average particle size is ≤35 μm, the average particle size after being placed at a temperature of 45°C for 24 hours is ≤35 μm, and the average particle size after being placed at a temperature of 45°C for 90 days is ≤45 μm, indicating that the sunscreen lotion of the present invention has high stability.

[0122] By comparing Application Example 1 with Application Examples 4-9, it can be seen that when the polysaccharide polymer is propylene glycol alginate and Chondrus crispus extract, the instability index of the obtained sunscreen lotion is ≤0.102, the average particle size is ≤22.5 μm, the average particle size after being placed at a temperature of 45°C for 24 hours is ≤22.5 μm, and the average particle size after being placed at a temperature of 45°C for 90 days is ≤31.5 μm, indicating that when the polysaccharide polymer is propylene glycol alginate and Chondrus crispus extract, the stability of the obtained sunscreen lotion is better. High; when the mass ratio of propylene glycol alginate and Chondrus crispus extract is 7:1-1:3, the instability index of the obtained sunscreen lotion is ≤0.092, the average particle size is ≤21.5μm, the average particle size after being placed at a temperature of 45°C for 24h is ≤21.5μm, and the average particle size after being placed at a temperature of 45°C for 90 days is ≤31.5μm, indicating that when the mass ratio of propylene glycol alginate and Chondrus crispus extract is 7:1-1:3, the obtained sunscreen lotion has higher stability.

[0123] Comparing Application Example 1 with Application Examples 10-14, when the polyols are dipropylene glycol and methyl propylene glycol, the instability index of the obtained sunscreen lotion is ≤0.135, the average particle size is ≤29μm, the average particle size after being placed at a temperature of 45°C for 24 hours is ≤29μm, and the average particle size after being placed at a temperature of 45°C for 90 days is ≤40μm, indicating that when the polyols are dipropylene glycol and methyl propylene glycol, the obtained sunscreen lotion has higher stability; when the mass ratio of dipropylene glycol to methyl propylene glycol is 1.5-4, the instability index of the obtained sunscreen lotion is ≤0.12, the average particle size is ≤26μm, the average particle size after being placed at a temperature of 45°C for 24 hours is ≤26μm, and the average particle size after being placed at a temperature of 45°C for 90 days is ≤36μm, indicating that when the mass ratio of dipropylene glycol to methyl propylene glycol is 1.5-4, the obtained sunscreen lotion has higher stability.

[0124] It can be seen from Comparative Application Examples 1 and 1-6 that the lack of at least one of the polysaccharide polymer and the polyol, or the use of monohydric alcohol to replace the polyol, or excessive addition of the polysaccharide polymer will lead to a significant increase in the instability index and average particle size of the sunscreen.

[0125] Effect Example 3

[0126] This effect example tests the skin feel and sun protection effect of the oil-in-water sunscreen lotion obtained from the application example, comparative application example and blank application example.

[0127] The specific steps are as follows:

[0128] The testing method for skin feel scoring is as follows: Refer to T / GDCA 003-2020T / GDCA General Rules for Sensory Evaluation of Cosmetics, recruit 30 volunteers, and evaluate from five dimensions: ease of application (0-5 points correspond to difficult to apply to easy to apply), water feel (0-5 points correspond to weak water feel to strong water feel), skin smoothness (0-5 points correspond to astringent to smooth), skin stickiness (0-5 points correspond to sticky to non-sticky), and overall absorption speed (0-5 points correspond to slow to fast). The comprehensive score is the average of the sum of the five scores. The higher the score, the better the skin feel.

[0129] The test method for instant sun protection effect is: refer to SN / T 5150-2019 In vitro determination method for UVA light protection effect of sunscreen cosmetics, and test the prepared sunscreen lotion on the UV-2000S equipment;

[0130] The calculation formula of SPF is:

[0131]

[0132] In formula 1, E(λ)——erythema effect coefficient;

[0133] I(λ)——Radiation intensity of UV light source;

[0134] A0——average monochromatic absorbance of each sample before UV irradiation;

[0135] d(λ)——wavelength step size (nm).

[0136] The calculation formula of PA is:

[0137]

[0138] In formula 2, P(λ)——PPD spectral index;

[0139] I(λ)——spectral irradiance of UVA light source;

[0140] A0 – monochromatic light absorbance of the test slide before exposure to UV;

[0141] C——Adjustment coefficient;

[0142] dλ——measurement wave step length (nm).

[0143] The test method for the long-term sun protection effect is: place the sunscreen lotions of the application example and the comparative application example at a temperature of 45°C for 90 days, and then test the SPF value and PA value of the sunscreen lotions according to the test method for the sun protection effect.

[0144] The test results are shown in Table 6.

[0145] Table 6

[0146]

[0147]

[0148] From the experimental data in Table 6, it can be seen that the SPA value of the sunscreen lotion of the present invention is ≥39.7, and the PA value is ≥8.4. After being placed at a temperature of 45°C for 90 days, the SPA value is ≥33.4, and the PA value is ≥6.2, indicating that the sunscreen lotion of the present invention has good immediate sunscreen effect and long-term sunscreen effect.

[0149] By comparing Application Example 1 and Application Examples 4-9, it can be seen that when the polysaccharide polymer is propylene glycol alginate and Chondrus crispus extract, the SPA value of the obtained sunscreen lotion is ≥53, the PA value is ≥12.8, and the SPA value after being placed at a temperature of 45°C for 90 days is ≥44, and the PA value is ≥9, indicating that when the polysaccharide polymer is propylene glycol alginate and Chondrus crispus extract, the instant sunscreen effect and long-term sunscreen effect of the obtained sunscreen lotion are better and higher; when the mass ratio of propylene glycol alginate and Chondrus crispus extract is 7:1-1:3, the SPA value of the obtained sunscreen lotion is ≥53.5, the PA value is ≥13, and the SPA value after being placed at a temperature of 45°C for 90 days is ≥45, and the PA value is ≥9.5, indicating that when the polysaccharide polymer is propylene glycol alginate and Chondrus crispus extract, the instant sunscreen effect and long-term sunscreen effect of the obtained sunscreen lotion are higher;

[0150] Comparing Application Example 1 with Application Examples 10-14, when the polyols are dipropylene glycol and methyl propylene glycol, the SPA value of the resulting sunscreen lotion is ≥51, and the PA value is ≥12.5. After being placed at a temperature of 45°C for 90 days, the SPA value is ≥42, and the PA value is ≥9, indicating that when the polyols are dipropylene glycol and methyl propylene glycol, the instant sunscreen effect and the long-term sunscreen effect of the resulting sunscreen are higher; when the mass ratio of dipropylene glycol and methyl propylene glycol is 1.5-4, the SPA value of the resulting sunscreen lotion is ≥55, and the PA value is ≥13.5. After being placed at a temperature of 45°C for 90 days, the SPA value is ≥47, and the PA value is ≥10, indicating that when the mass ratio of dipropylene glycol and methyl propylene glycol is 1.5-4, the instant sunscreen effect and the long-term sunscreen effect of the resulting sunscreen are higher.

[0151] It can be seen from Comparative Application Examples 1 and 1-6 that the lack of at least one of the polysaccharide polymer and the polyol, or the use of monohydric alcohol to replace the polyol, or excessive addition of the polysaccharide polymer will lead to a significant decrease in the immediate and long-term sunscreen effects of the sunscreen lotion.

[0152] Finally, it should be noted that the above embodiments are used to illustrate the technical solution of the present disclosure rather than to limit the protection scope of the present disclosure. Although the present disclosure has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present disclosure can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present disclosure.

Claims

1. A titanium dioxide aqueous dispersion, characterized in that: The invention comprises the following components in parts by weight: 60-75 parts of nano titanium dioxide, 10-25 parts of polyol, 1-5 parts of polysaccharide polymer and 10-20 parts of water; wherein the polysaccharide polymer comprises propylene glycol alginate.

2. The titanium dioxide aqueous dispersion according to claim 1, characterized in that The polysaccharide polymer further comprises at least one of Chondrus crispus extract, sodium carrageenan, acacia gum, karaya gum, and carboxymethyl chitosan.

3. The titanium dioxide aqueous dispersion according to claim 2, characterized in that The polysaccharide polymer is propylene glycol alginate and Chondrus crispus extract, and the mass ratio of propylene glycol alginate to Chondrus crispus extract is 7:1-1:

3.

4. The titanium dioxide aqueous dispersion according to claim 1, characterized in that The polyol is at least one of glycerol, ethylene glycol, propylene glycol, butylene glycol, dipropylene glycol, pentylene glycol, hexylene glycol, and methylpropylene glycol.

5. The titanium dioxide aqueous dispersion according to claim 4, characterized in that The polyols are dipropylene glycol and methyl propylene glycol, and the mass ratio of dipropylene glycol to methyl propylene glycol is 1.5-4.

6. The aqueous titanium dioxide dispersion according to claim 1, characterized in that The nano titanium dioxide is modified by a surface treatment agent, and the surface treatment agent is at least one of a silane coupling agent, hydrogenated polydimethylsiloxane, silicon dioxide, aluminum hydroxide, and amino acid.

7. The method for preparing the titanium dioxide aqueous dispersion according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: after uniformly mixing the polyol and the polysaccharide polymer, adding water, heating to 60-80°C and stirring until transparent, then adding nano titanium dioxide, homogenizing at a speed of 5000-8000 r / min for 3-5 minutes, stirring and cooling to room temperature to obtain titanium dioxide water dispersion.

8. Use of the titanium dioxide dispersion according to any one of claims 1 to 6 in cosmetics.

9. A cosmetic, characterized in that: The titanium dioxide aqueous dispersion comprises the titanium dioxide aqueous dispersion as claimed in any one of claims 1 to 6, wherein the mass percentage of the titanium dioxide aqueous dispersion in the cosmetic is 6-15%.

10. The cosmetic according to claim 8, characterized in that The cosmetic is a sunscreen lotion, and the sunscreen lotion comprises the following components in percentage by mass: 6-15% titanium dioxide aqueous dispersion, 5-15% organic sunscreen, 5-30% oil, 0.5-5% emulsifier, 0.1-5% skin conditioner, 0.1-20% moisturizer, 0.05-5% rheology regulator, 0.05-3% antioxidant, 0.1-0.6% preservative, 0.05-5% pH regulator, 0.01-1% fragrance, and the balance water.

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