Novel multifunctional biodegradable micro powder

Abstract

The invention preferably relates to a micropowder having an oil absorption capacity of at least 2.5 g / g, wherein the micropowder is biodegradable. The invention preferably further relates to a biodegradable micro-powder comprising bacterial cellulose particles wherein the bacterial cellulose particles have an average particle size of between 1 [mu] m and 1000 [mu] m and an average crystallinity of between 30% and 80%. The invention also preferably relates to a method for producing a micropowder. The method comprises the steps of: producing bacterial cellulose from a bacterial culture such that the average crystallinity of the produced bacterial cellulose is between 30% and 80%; grinding the bacterial cellulose to form bacterial cellulose particles having an average particle size of 1 [mu] m to 1000 [mu] m; and drying the ground bacterial cellulose particles. The invention also relates to a cosmetic or personal care product comprising said micro powder.

Description

[0001] describe

[0002] The present invention preferably relates to micropowders having an oil absorption capacity of at least 2.5 g / g, wherein the micropowders are biodegradable. The present invention also preferably relates to a biodegradable micropowder comprising bacterial cellulose particles, wherein the average particle size of the bacterial cellulose particles is between 1 μm and 1000 μm, and the average crystallinity of the bacterial cellulose particles is between 30% and 80%. The present invention also preferably relates to a method for producing the micropowder. The method comprises the steps of producing bacterial cellulose from a bacterial culture such that the average crystallinity of the produced bacterial cellulose is between 30% and 80%; grinding the bacterial cellulose to form bacterial cellulose particles having an average particle size of 1 μm to 1000 μm; and drying the ground bacterial cellulose particles. The present invention also relates to a cosmetic or personal care product comprising the micropowder. Background Art

[0003] The present invention relates to the field of micropowders and microbeads, particularly biodegradable micropowders. More specifically, the present invention relates to the field of biodegradable micropowders suitable for use as a solid or in combination with various organic and inorganic media as a rheology modifier, viscosity enhancer, texture enhancer, texturizing agent, sensory enhancer, or opacifier.

[0004] It is known to use micropowders and microbeads to adjust the aesthetics, sensory properties, rheological properties, hydrophobicity, hydrophilicity, oil absorption capacity, UV absorption capacity or other functional properties of solid or liquid products. Such powders and microbeads are currently used in a variety of products, such as personal care, home care, dental care, pharmaceutical products, coatings and paint formulations. They are generally made of non-biodegradable synthetic polymers and minerals and metal oxides.

[0005] In the case of liquid products, sunscreens and foundations can be used as an example. Titanium dioxide (TiO2) particles contribute to opacity and sun protection properties and are usually provided in powder form and suspended in the formulation to adjust its color and solar absorbance. Such formulations are often stored for several months before use, during which time the suspended particles may settle, resulting in inconsistent product color and opacity. To avoid this, the suspended particles are ground to a very small diameter and combined with rheology modifiers to slow down any settling behavior. In addition, the adhesion of the formulation to the skin and the avoidance of unwanted wetness, greasiness or stickiness depend on the absorption capacity of the formulation. Due to the low oil and water absorption capacity of titanium oxide particles, additional microbeads, for example made of talc or plastic, can be added.

[0006] As an example of a solid product, consider pressed powders. Pressed powders are typically based on crushed mineral materials (e.g., talc, silica) or metals (e.g., magnesium). In some cases, microbeads are also an important component of such products. Titanium dioxide and zinc oxide particles are common additives used to adjust the opacity of the product or to obtain sufficient sun protection. Metal, mineral, or plastic powders are also often used to provide the required pigments for such pressed powders. In addition to aesthetic qualities, consumers now have high demands on such products, requiring them to provide a soft, non-greasy finish, fill pores, and / or remain on the skin comfortably for a long time despite the production of sebum. These texture characteristics are typically provided by fine plastic powders containing materials such as polymethyl methacrylate or trimethylol hexyl lactone.

[0007] A major drawback of these known micropowders is their lack of biodegradability, which has become a pressing environmental and public health concern. There is ample evidence that microplastics have been ingested by fish and have entered the market. Such microplastics can rapidly travel through the human body and are suspected of crossing the blood-brain barrier, causing neurological problems and impacting the human immune system. Therefore, there is an urgent need to develop biodegradable and biocompatible alternatives to the currently widely used existing powders.

[0008] Furthermore, concerns have arisen in recent years about the safety of many micronized ingredients commonly used in various consumer products. For example, talc—a common ingredient in pressed powders, deodorants, and baby care products—is suspected of being carcinogenic due to its presence in tumors. Because talc occurs naturally on the Earth's surface, close to other known carcinogenic minerals such as asbestos, there are concerns about cross-contamination during its mining process. This could result in asbestos entering the human body as part of this talc.

[0009] Very fine aluminum particles (10-50 microns) or aluminum salts are also used in deodorants to improve the feeling of dryness and provide an antiperspirant effect by blocking pores. The small size of the particles gives them a high absorption capacity, allowing them to be easily dispersed in sprays and remain unnoticeable to the user. However, their small size allows them to overcome tissue barriers and enter the body. In recent years, a link has been discovered between breast cancer and the use of aluminum-based deodorants. It is thought that the fine aluminum particles can enter the lymph nodes and travel to breast tissue, leading to an increase in tumors observed near the lymph nodes. Because these particles cannot be broken down by the body, they accumulate and pose a risk to surrounding tissue. Therefore, there is a need to replace these powders with safer, more biocompatible alternatives.

[0010] Furthermore, there has recently been a push from both consumers and regulators to replace synthetic ingredients (not only in cosmetics but in all consumer products) with naturally derived raw materials, or to develop formulations composed partially or entirely of natural ingredients. Consequently, there is a need for viable alternatives that are not only biodegradable and safer than existing options, but also meet consumer demands for product aesthetic quality, feel, and functionality. In particular, there is a need for a multifunctional, biodegradable micropowder that can fulfill the functionalities of several powder types—from opacity to oil absorption and a soft texture.

[0011] Consideration has been given to using natural polymers to replace non-biodegradable powders made from non-natural polymers. For example, US2011274629A1 teaches the use of modified xanthan gum and galactomannan as dry powder mixtures for the manufacture of personal care products. While these powder mixtures have been found to provide sufficient thickening for emulsions and other applications, they cannot match the versatility of traditional microplastics. The application of dry powder mixtures to solid (rather than emulsified or liquid) end products has not yet been explored. Consumers currently have high expectations for cosmetics and personal care products applied to the skin. Ideally, they should have a soft, natural-looking texture without drying, caking, or flaking. Skin care products can flake when they do not adhere adequately to the skin or when they are unable to absorb the layer of sebum that accumulates between the product and the skin. This is believed to be due to the limited absorption capacity of known biodegradable alternatives to metal and plastic microbeads. Therefore, there is a need for micropowders that are not only biodegradable but also provide a long-lasting, soft texture and a matte appearance upon application.

[0012] Plant cellulose is also considered a potential alternative to synthetic, non-biodegradable powder materials. Cellulose is typically made from wood pulp and combined with ingredients such as wax, lignin, pectin, and hemicellulose. These additional ingredients and the chemical structure of plant cellulose limit its hydrophilicity and solubility in aqueous media. Therefore, producing smooth emulsions from plant cellulose presents challenges. In addition, its natural off-white color makes it less suitable for use in paints or white products, while metal oxides remain the preferred choice. Furthermore, to date, no products containing plant cellulose-based powders have been found to meet consumer demand for a soft texture and non-greasy feel.

[0013] Surface-modified bacterial cellulose has also found applications beyond the consumer goods sector due to its oil absorption capacity. For example, CN103962105A discloses a PTES (phenyltriethoxysilane) surface-modified bacterial cellulose aerogel oil-absorbing material for use in cleaning up oil spills. The gel is prepared by crushing a bacterial cellulose membrane, mixing the crushed membrane with deionized water, and freeze-drying it for 24 to 72 hours to produce the aerogel. The aerogel is then functionalized in ethanol to increase its hydrophobicity. It is this improved functionality that enables it to achieve the claimed oil absorption capacity of up to 50 g / g. While this demonstrates the existence of natural-based materials with high oil absorption properties, it cannot replace known micropowders and microbeads. Gels are homogeneous structures that rely on the network effect formed between long fibers. On the other hand, micropowders and microbeads are preferably formed as discrete particles. Particle aggregation is generally undesirable. In particular, in the case of scrubs and exfoliants, hardened, distinct particles are required to achieve the scrubbing function.

[0014] The high hydrophobicity and modified chemical structure of the aerogel may be suitable for oil spills, but not for use on skin, where chemical stability, non-stickiness, and non-greasy properties are required. In addition to these limitations, surface modification of cellulose with PTES also makes the resulting gel petroleum-based, so it is no longer biodegradable.

[0015] CN103966700A discloses another example of oil-absorbing aerogel made from bacterial cellulose. The aerogel is formed by growing a bacterial cellulose membrane, grinding and mixing the membrane with deionized water to form a hydrogel, and then freeze-drying the hydrogel to form the aerogel. The aerogel is manufactured in a size range of 1 cm 2 Up to 50cm 2 The aerogel is both hydrophobic and oleophilic, allowing it to absorb oil spills in water. Due to its hydrophobic nature, the aerogel can selectively absorb oil spills in water, completely filling the pores within its fiber network with the unwanted oil.

[0016] Due to its gelling properties, aerogels are not suitable for use as biodegradable micropowders in most consumer products. This is because the discrete pieces of aerogel will swell and lose their distinctive shape as they gradually form a colloidal network with the oily components of the formulation. For aqueous or emulsion-based formulations, aerogels have poor miscibility with the formulation, particularly due to their hydrophobicity, which can lead to phase separation. Therefore, bacterial cellulose aerogels are also not suitable for making micropowders for use in formulations.

[0017] CN104017233A discloses a further example of an oil-absorbing aerogel made from bacterial cellulose. This is manufactured in a similar manner, based on cultivating a bacterial cellulose membrane, grinding and mixing the membrane with deionized water to form a hydrogel, and then freeze-drying the hydrogel to form the aerogel. The aerogel is described as a highly porous, three-dimensional network structure with a high affinity for oil, making it useful for oil-water separation. However, due to its gelling properties, this material is unsuitable for use as a micropowder in most consumer products. In particular, the gel's particle size and dispersibility in formulations do not meet the characteristics of a powder, nor does it provide a texture suitable for scrubbing.

[0018] To avoid the inconvenience associated with transporting and handling large volumes of cellulose gel, CN10935407A discloses an alternative preparation method, in which bacterial cellulose is powdered, which can then be reconstituted into a gel. This powder can be added to food preparations as a thickener. Due to the dry conditions during its manufacturing process, the powder has a loose fiber structure that forms a gel when added to a fluid. In addition, due to the low porosity and density of the powder, its absorption capacity for water and oil is low. In addition, its open fiber structure can lead to high expansion, which can reduce its particle size when added to liquid preparations and may have an adverse effect on the fluidity of the preparation. Therefore, there is a need for a powder that is highly absorbable, biodegradable, and not prone to forming a gel in liquid preparations.

[0019] WO2019004520A1 discloses a bacterial cellulose powder for use in cosmetics. This powder is intended to replace microplastics in cosmetic formulations. To produce bacterial cellulose powder suitable for such cosmetic formulations, WO2019004520A1 teaches that it is important to completely remove the oil and moisture between the individual fibers of the biocellulose to eliminate the powder's absorption capacity. Consequently, bacterial cellulose has little or no absorption properties, such as maintaining its particle size when used in liquid formulations. Due to its lack of absorbency, this powder is unable to provide the soft, matte finish desired in many cosmetics. Furthermore, the powder tends to have a large diameter and does not adhere easily to the skin, particularly due to its lack of oil absorption. Consequently, cosmetics produced using this powder easily flake and are therefore of substandard quality.

[0020] Ideally, microbeads for use on the skin should be fully biodegradable and prevent accumulation in the body. They should also maintain their particle size in fluid suspension and possess sufficient oil absorption. Therefore, there is a need for micropowders with materials and properties suitable for use in a variety of everyday consumer products.

[0021] There is a need for alternative micropowders with diverse properties. Preferably, the micropowder is biodegradable and derived from renewable resources. The micropowder is preferably a good sunscreen, neutral in color, provides favorable rheological properties, and is biosafe. It is particularly preferred that the micropowder does not pose a health hazard to humans if it enters the food chain. To effectively replace synthetic powders used in cosmetics and personal care products, a biodegradable powder is needed that provides a soft, non-sticky, non-greasy feel on the skin. Summary of the Invention

[0022] The object of the present invention is to overcome the disadvantages of the previously known micropowders and microbeads and methods for their production.

[0023] This problem is solved by the features of the independent claim. Preferred embodiments of the invention are given by the dependent claims.

[0024] In one aspect, the present invention relates to a micropowder comprising bacterial cellulose particles. The micropowder has an oil absorption capacity of at least 2.5 g / g and is biodegradable.

[0025] Bacterial cellulose has been found to be a surprisingly versatile and advantageous alternative to materials traditionally used in powdered form as ingredients in many industries. Compared to metals and synthetic polymers, bacterial cellulose is highly biodegradable. In particular, bacterial cellulose in powdered form can reach a biodegradation level of 75% within 28 days. Within 60 days, bacterial cellulose powder can be completely biodegraded. Bacterial cellulose is provided as a micropowder by washing and grinding harvested cellulose, suspending it in deionized water and oven drying it, spray drying it, treating it with supercritical CO2, or freeze drying it to form a non-gelling micropowder. The micropowder can be free of organic solvents while having a large surface area to mass ratio and high porosity. In addition, the micropowder can maintain its particle size when suspended in liquid formulations. The surface of bacterial cellulose is sufficiently amphiphilic that it can be attacked by microorganisms and quickly decomposed.

[0026] These results show that the bacterial cellulose-based micropowder has great potential to replace currently used metals, minerals and microplastics. Because bacterial cellulose is rapidly biodegradable in nature, the risk of it entering the global food chain is much lower. In any case, people's concerns about the accumulation of microplastics in water bodies and food chains can be alleviated because bacterial cellulose is not only a naturally occurring material that can be digested and safely consumed by many organisms, it can also be safely decomposed in water, air or soil. From an environmental perspective, ground and dried bacterial cellulose micropowder without organic solvents is a much more attractive alternative to currently used powders.

[0027] Compared to traditional powders, bacterial cellulose powder has also been found to be surprisingly biocompatible. Unlike known powder additives such as talc and aluminum, bacterial cellulose does not pose any health concerns. In contrast, plant cellulose, which has similar chemical properties, is commonly and safely consumed by humans as dietary fiber. Plant cellulose is also traditionally used in various materials that come into contact with human skin, such as cotton fabrics, bandages, and traditional medicines and cosmetics. It is based on herbs, roots, stems, and leaves. Therefore, it is a particularly safe material.

[0028] Using bacterial cellulose instead of plant cellulose offers further advantages. Bacterial cellulose does not contain the waxes, lignin, pectin, and hemicellulose typically found in cellulose produced from plant sources. Cultivation in a controlled environment ensures a very high purity of the bacterial cellulose. This is particularly useful when the biodegradable powder of the present invention is used in food, pharmaceutical, or healthcare products.

[0029] Compared to plant cellulose, bacterial cellulose tends to have a more crystalline structure and can form characteristic ribbon-like microfibrils. In particular, the microfibrils of bacterial cellulose are much smaller than those of plant cellulose, making bacterial cellulose-based micropowders much more porous when cultured, ground and dried using appropriate techniques. Advantageously, as described in more detail herein, porosity can increase the surface area, thereby increasing the surface interactions of the bacterial cellulose particles, providing a variety of interesting effects. In addition, porosity can reduce the overall density of the bacterial cellulose particles, making them particularly light. It was found that porosity is affected by the crystallinity of the bacterial cellulose. Since bacterial cellulose can achieve a much wider range of crystallinity, it can be adjusted during the production process of the micropowder. It was found that a crystallinity of 30% to 80% provides high porosity and surface irregularities, which increases the surface area of ​​the bacterial cellulose particles, especially when dried. This can be further improved by adjusting the average particle size of the micropowder to maximize the surface area available for molecular interactions with the surrounding medium (such as oil or water). The inventors have discovered that dried bacterial cellulose particles can act as excellent thickeners and rheology modifiers due to their ability to be suspended in large quantities in various fluid media. This allows for extended shelf life of multiphase emulsions, thereby providing high user satisfaction.

[0030] Furthermore, as will be explained further herein, it is believed that the increased porosity of the bacterial cellulose particles, particularly when dried after keratinization, such as by oven drying or spray drying, may contribute to their surprisingly high oil absorption capacity. The oil absorption of the micropowders of the present invention is not only comparable to, but far exceeds, that of other highly absorbent powders. This implication has crucial implications for the production of a wide variety of consumer products. One such implication is that prior art microplastic, metal, and mineral powders can be replaced by the much safer, fully biodegradable powders of the present invention without sacrificing absorption function or reducing consumer satisfaction. Surprisingly, the functionality of conventional powders can be significantly improved.

[0031] For cosmetics and personal care products, the high oil absorption of bacterial cellulose enables products containing the powder of the present invention to absorb sebum from the skin at high capacity over a long period of time. As a result, people can wear the product comfortably for extended periods without experiencing a sticky, greasy, or clumping sensation. The product can provide a very soft, matte appearance and texture, concealing unevenness and pores. Subjects also report that such products leave a pleasant, non-greasy, non-sticky after-feel.

[0032] In addition to its favorable texture, the high oil absorption capacity of bacterial cellulose particles also enables the production of products with high oil content without compromising stability, shelf life, or aesthetics. For example, products can carry higher amounts of essential oils, cocoa butter, or other vegetable oils for fragrance or flavoring, imparting a very high-quality impression. Potential applications include cosmetics, personal care products, and food.

[0033] Bacterial cellulose preferably comprises an ultrafine network of highly uniaxially oriented cellulose fibers. This type of 3D structure can lead to particularly high crystallinity and favorable physicochemical and mechanical properties, particularly when manufactured into the micropowders described herein. This structure facilitates the formation of bacterial cellulose films, which are preferably sheet-like or film-like bacterial cellulose layers. The crystallinity of bacterial cellulose can impart rigidity to the microfibers and can be used to adjust the mechanical properties of the resulting product. These properties include flexibility, elasticity, and tensile strength. Crystallinity also imparts excellent thermal and chemical stability to bacterial cellulose particles. Therefore, bacterial cellulose is a particularly versatile material for use as a biodegradable powder.

[0034] In the sense of the present invention, "micropowder" is preferably a material comprising particles, grains or fragments. At least one spatial dimension of the particles, grains or fragments is preferably in the micrometer range. Preferably, the average length, width, thickness or diameter of the particles, grains or fragments is less than 1000 μm. The micropowder is preferably dry, with a moisture content of less than 5w / w%, preferably less than 1w / w%, more preferably less than 0.5w / w%. The micropowder preferably maintains its particle size in aqueous, oily or emulsified fluid formulations. In addition, the average expansion degree of the micropowder in the fluid formulation is preferably no more than 100 volume %, more preferably no more than 70 volume %, even more preferably no more than 50 volume %, even more preferably no more than 25 volume %, wherein the expansion degree is preferably proportional to the increased volume of the expanded particles divided by the original volume of the particles.

[0035] Micropowders are preferably distinguished from gels because they do not swell in fluids and because they have a high volume fraction of solid material. Thus, when stored in air at ambient conditions or suspended in a liquid formulation, the particles of the micropowder preferably contain at least 5% by mass, more preferably at least 10% by mass, and even more preferably at least 15% by mass solids. Furthermore, micropowders are preferably not suitable for containing fluids to form a substantially uniform colloid. Formulations containing micropowders in a continuous liquid phase at concentrations up to 5% w / w, more preferably up to 10% w / w, are preferably characterized as liquids rather than soft solids or semisolids.

[0036] On the other hand, the term "gel" as used herein preferably refers to a substantially homogeneous material comprising a three-dimensional fiber or polymer network and a fluid dispersed therein, wherein the mass of the fluid is preferably several times greater than the mass of the fiber or polymer network. The three-dimensional fiber or polymer network preferably captures the fluid, in particular the liquid, so as to immobilize it and prevent it from flowing without applying a minimum yield stress. The minimum yield stress of the gel is preferably at least 10 Pa, more preferably at least 50 Pa, even more preferably at least 100 Pa, even more preferably at least 200 Pa, even more preferably at least 500 Pa. The gel is preferably a soft solid or semisolid, in particular because the liquid is trapped in the fiber or polymer network. Preferably, the mass of the fluid in the gel is at least five times greater than the mass of the fiber or polymer network, more preferably at least ten times, even more preferably at least 20 times.

[0037] The gellable material is preferably a solid material that expands when added to a liquid to form a loose fiber or polymer network of the desired gel. When added to a liquid, the gellable material preferably expands to at least two times its volume, preferably at least five times, more preferably at least ten times, and even more preferably at least 20 times.

[0038] In the sense of the present invention, a micropowder is preferably neither a gel nor a gellable material.

[0039] In the sense of the present invention, "oil absorption capacity" is preferably a measure of the mass of oil that can be bound to a single gram of micropowder, expressed in grams. The oil absorption capacity can be determined with reference to any oil, preferably any non-polar material composed primarily of hydrocarbons that is liquid at 25°C. As a reference oil, sunflower oil can be used. Preferably, the oil absorption capacity is determined experimentally using ASTM D281-95 or a modified version thereof.

[0040] In the context of the present invention, "biodegradability" is preferably a measure of the length of time it takes for a material to decompose after exposure to biological elements. The breakdown of cellulose preferably involves the fragmentation of cellulose polymers into dimers or monomers. Biodegradability can be determined using an OxiTop measuring device. A known mass of the material to be tested can be exposed to microorganisms in a test bottle. During the biodegradation of the test material, the microorganisms can convert oxygen (O2) into carbon dioxide (CO2). It is preferably a cap-shaped manometer connected to the test bottle, which measures the biochemical oxygen demand by detecting the degree of decrease in the air pressure in the bottle. After the test bottle is sealed with a cap, it can be incubated in a constant temperature chamber (e.g., IN804, Yamato Scientific, Japan). According to the OECD (Guideline for Testing Chemicals: Ready biodegradability (1992)) and CSCL (Guideline of Chemical Substances Control Law: Biodegradability Test of Chemical Substances by Microorganisms (2018) (Japanese)) guidelines, when the biochemical oxygen demand value during the test reaches 60% of the theoretical oxygen demand of the test chemical (especially in the 301C or 301F test procedures), the test chemical is considered to be completely degraded (the remaining 40% is considered to have been assimilated by microorganisms).

[0041] In the sense of the present invention, "bacterial cellulose" is preferably cellulose synthesized by bacteria and is also referred to as "microbial cellulose" or "biocellulose". Bacterial cellulose is a polysaccharide chain consisting of several β(1→4) linked D-glucose units. Its chemical structure can be represented by the molecular formula (C6H 10 O5) nIn the sense of the present invention, the bacterial cellulose may also have a chemical structure different from the chemical formula, in particular in the case of functionalized bacterial cellulose. The bacteria used to synthesize the bacterial cellulose may preferably belong to the genus Gluconacetobacter, Acetobacter, Aerobacter, Achromobacter, Azotobacter, Rhizobium, Lactobacillus, Agrobacterium, Pseudomonas, Alcaligenes, Salmonella or Sarcinia. Suitable bacterial species known to experts in the field include, but are not limited to, Gluconacetobacter xylinus, Gluconacetobacter hansenii, Acetobacter xylinum, Acetobacter senegalensis, Acetobacter pasteurianum, Acetobacter rancens, Sarcina ventriculi and Lactobacillus Mali. Co-culture of two or more bacteria may also be used. Bacterial cellulose can be cultivated in the culture medium that carbon source, optional nitrogen source and any further think suitable macro or micronutrient are provided.The example of carbon source comprises glucose, fructose, sucrose, maltose, xylose, mannitol, glycerine and molasses.Can preferably use Hestrin-Schramm culture medium to cultivate bacterium.Bacteria can be cultivated in static or agitated environment, and the incubation time can change between 30-300 hours.Bacterial cellulose is preferably produced in the form of one or more thin sheets (also referred to as films (Pellicles), membranes (films) or membranes (membranes)).

[0042] In a preferred embodiment of the invention, the micropowder is biodegradable to 75% within 35 days. Preferably, the micropowder is biodegradable to 75% within 28 days. Unless otherwise stated, percentage biodegradability preferably refers to the w / w percentage of material that has been degraded or absorbed by microorganisms.

[0043] By adjusting the micropowder's biodegradability to 75% within 28 days, it can be rapidly biodegraded, reducing the need for any special disposal measures to prevent it from entering sewers or the food chain. This is due, in particular, to the micropowder's small particle size, high porosity, and high surface area to mass ratio, which increase its contact with air and microorganisms. Products formulated using the micropowder can be highly biodegradable and environmentally friendly. Thus, the micropowder satisfies a long-standing market demand for a micropowder that can be disposed of like other consumer products without creating environmental concerns.

[0044] In a further preferred embodiment of the present invention, the micropowder has an oil absorption capacity of at least 4 g / g, preferably at least 4.5 g / g, and even more preferably at least 5 g / g. By tailoring the properties of the bacterial cellulose particles to achieve this oil absorption capacity, the micropowder of the present invention can perform far better than known micropowders while being fully biodegradable and safe. Preferably, the micropowder exhibits these absorption capacities for a range of oils, including but not limited to: sunflower oil, vegetable oil, canola oil, olive oil, rapeseed oil, neem oil, glycerin, lavender, tea tree oil, essential oils, and jojoba oil.

[0045] This oil-absorbing ability provides a highly sought-after property, particularly in the cosmetics and personal care product sectors. Products intended for use on the skin are in high demand, offering a soft texture, particularly a "blur" or "airbrush" effect. This effect is achieved by absorbing sebum produced beneath the product on the skin, preventing the product from flaking, cracking, or otherwise experiencing a difference in its texture. Manufacturers of such products have resorted to using harmful and non-biodegradable micropowders to package these products. The inventors have discovered that the micropowders of the present invention can be readily formulated to achieve higher oil absorption capacities than those achieved with known micropowders.

[0046] By way of illustration only, the micropowder of the present invention can absorb sunflower oil at a capacity of greater than 5 g / g. Under the same conditions, a micropowder made from kaolin, vinyl dimethylsiloxane crosspolymer, and PMMA (polymethyl methacrylate) can absorb less than 2 g / g of sunflower oil. The oil absorption capacity of the micropowder of the present invention also far exceeds that of talc (which is approximately 1.5 g / g). Subjects treated with formulations containing like-for-like quantities of the micropowder of the present invention and the aforementioned micropowder made from PMMA and silica were significantly more satisfied with the formulation containing the micropowder of the present invention. In particular, they reported a high degree of softness during application and a soft feeling after use. Subjects also reported that the formulation containing the micropowder of the present invention was far less greasy than alternatives and left a much less greasy and sticky feeling after use. These results, which will be explained in more detail herein, demonstrate significant potential for improving the quality of consumer products.

[0047] In further preferred embodiments of the present invention, the oil absorption capacity of the micropowder is at least 7 g / g, at least 10 g / g, at least 12 g / g, at least 15 g / g, at least 20 g / g, at least 25 g / g or more.

[0048] In a further preferred embodiment of the present invention, the micropowder has an oil absorption capacity relative to oleic acid of at least 2.5 g / g, preferably at least 3 g / g, more preferably at least 3.5 g / g, more preferably at least 4 g / g, preferably at least 4.5 g / g, more preferably at least 5 g / g, more preferably at least 5.5 g / g, more preferably at least 6 g / g, more preferably at least 6.5 g / g, more preferably at least 7 g / g, more preferably at least 7.5 g / g, more preferably at least 8 g / g, and even more preferably at least 10 g / g. Using oleic acid as a reference material is particularly advantageous because it is a common reference material in the cosmetic and cosmeceutical industries, allowing for like-for-like comparisons of the oil absorption capacities of different materials. Furthermore, oleic acid is a frequently used ingredient in many cosmetic and personal care products, primarily as an emollient. Therefore, the high absorption rate of oleic acid allows for high loadings of oleic acid in products.

[0049] In a preferred embodiment of the present invention, the average particle size D of the bacterial cellulose particles is 50 Between 1 μm and 1000 μm. However, even more preferably, the average particle size D of the bacterial cellulose particles is 50 The particle size is between 1 μm and 500 μm, preferably between 5 μm and 250 μm, more preferably between 25 μm and 100 μm, and particularly preferably between 30 μm and 75 μm. An average particle size of approximately 65 μm is also preferred. These preferred average diameters offer a balance between lightweight particles and high dispersibility, along with safety. These particles disperse easily, filling pores and sweat glands and concealing skin irregularities. The high absorption capacity and small particle size facilitate good adhesion of the micropowder to the skin, and provide high flexibility when liquid formulations dry on the skin, leaving a film. Consequently, materials comprising the powder can be easily applied to cover diverse and dynamic skin surfaces without cracking or flaking. At particularly preferred particle sizes, bacterial cellulose micropowders also exhibit exceptional light-scattering properties, which contribute to a soft, matte makeup effect. The preferred diameters have also been shown to provide an optimally high porosity within the mesoporous range, enabling rapid fluid absorption through capillary action while maintaining the powder's particle size. This prevents particle swelling while providing efficient and rapid absorption, making the powder particularly comfortable and stable when applied to the skin. At the same time, the risk of penetrating tissue barriers is reduced, making the micropowder particularly biocompatible.

[0050] In a further preferred embodiment of the present invention, the average particle size D of the bacterial cellulose particles is 50 The cellulose particles of this size, obtained through experiments by the present inventors, are between 8 μm and 65 μm and exhibit particularly favorable absorption, adsorption, adhesion and light scattering properties.

[0051] The average particle size D of the bacterial cellulose particles may also be preferably 50The particle size of the micropowder is between 200 μm and 1000 μm, preferably between 400 μm and 1000 μm, even more preferably between 500 μm and 1000 μm, and even more preferably between 500 μm and 800 μm. At these particle sizes, the micropowder can be used in cleansing products, scrubs, and exfoliants, providing the rough texture required in these applications. At the same time, the micropowder is lightweight and easy to disperse. Even at these particle sizes, the micropowder of the present invention has a significantly greater oil absorption capacity than conventional micropowders. This allows for excellent cleansing while leaving a soft after-feel on the user's skin.

[0052] In a further preferred embodiment of the present invention, at least 90% of the bacterial cellulose particles have a diameter of no more than 500 μm, preferably no more than 300 μm, and particularly preferably no more than 200 μm. This micropowder comprises very fine particles with a sufficiently broad particle size distribution. This broad particle size distribution can help provide desirable semi-matte or matte finishes, such as in lipsticks and other cosmetics.

[0053] In a further preferred embodiment of the present invention, the average particle size D of the bacterial cellulose particles is 50 Not greater than the 90th percentile particle size D of the micropowder 90 The value of micronized powder is not more than 40%, preferably not more than 30%, and even more preferably not more than 25%. Therefore, micronized powder can have a large particle size distribution. This can help to provide a much more matte finish in some products. It has also been found to provide a smooth thickening and lengthening effect in mascara liquids.

[0054] In a further preferred embodiment of the present invention, the 90th percentile particle size D 90 The values ​​range from 20 μm to 200 μm. In particular, in the combination of average diameters of 8 μm to 65 μm, the experimentally produced micropowders are suitable for a wide range of purposes, especially cosmetic and cosmeceutical preparations.

[0055] The present inventors have found that the size and crystallinity of bacterial cellulose particles constitute factors that can be advantageously used to achieve a high oil absorption capacity ratio. In this regard, it has been shown that the average particle size D of bacterial cellulose particles is 50 It is particularly advantageous if the bacterial cellulose particles have a diameter between 1 μm and 1000 μm and an average crystallinity between 30% and 80%.

[0056] In a further preferred embodiment of the present invention, the average particle size D of the bacterial cellulose particles is 50 The average crystallinity of bacterial cellulose particles ranged from 30% to 80% between 1 μm and 1000 μm.

[0057] The average diameter of the bacterial cellulose powder is 1 μm to 1000 μm, preferably 1 μm to 500 μm, more preferably between 5 μm and 250 μm, more preferably between 25 μm and 100 μm, and particularly preferably between 30 μm and 75 μm, so that the bacterial cellulose powder can play a variety of functions. At these diameters, bacterial cellulose particles can be easily dispersed in suspensions. Therefore, they can form stable creams, lotions, paints, etc. At the same time, bacterial cellulose powder is suitable for use in dry products (such as loose powder or pressed cosmetic powder). The powder has excellent adhesion to the skin, providing a comfortable, non-sticky, non-greasy texture and a matte makeup effect. It has also been found to be very suitable for filling pores, fine lines and concealing uneven areas of the skin. These properties are highly sought after in the cosmetics field.

[0058] Within the selected average diameter range, bacterial cellulose powders exhibit a very high surface area-to-mass ratio. This can be further increased by adjusting the crystallinity and resulting porosity of the bacterial cellulose used. Consequently, bacterial cellulose particles can be made very lightweight while possessing a large surface area for interaction with fluids, particularly through intermolecular forces. Consequently, bacterial cellulose particles can be suspended in aqueous, inorganic, and organic media without settling. This allows the production of emulsions and suspensions with long shelf lives. The high surface area-to-mass ratio provided by the selected average diameter range also helps to increase the water and oil absorption capacity of the biodegradable powder.

[0059] An average crystallinity within the selected range of 30% to 80%, preferably between 40% and 80%, more preferably between 40% and 60%, particularly preferably between 40% and 50%, and even more preferably around 45%, synergistically with the selected average particle size provides optimal material properties and oil absorption capacity. At these crystallinity levels, the bacterial cellulose harvested from the film comprises a mixture of crystalline and amorphous phases. Without being limited by theory, the inventors hypothesize that this mixture of crystalline and amorphous phases results in increased porosity, particularly at the interfaces between the phases. Consequently, the bacterial cellulose material can become lighter and more porous.

[0060] Increased crystallinity increases the tendency of bacterial cellulose to keratinize during drying, which is believed to be due to the dense packing of bacterial cellulose fibers. As a result, the resulting micropowder is essentially solid, and fluid absorption occurs primarily on its surface and within its pores. This is significantly different from the absorption mechanism of gelable cellulose materials, in which fluids are trapped in a loose network of fibers. In particular, the increased crystallinity of the bacterial cellulose of the preferred embodiment of the present invention reduces its swelling behavior when immersed in liquid. Therefore, the preferred crystallinity also allows the micropowder to maintain its particle size and small particle size to fill and smooth pores and fine lines, and provide a scrubbing effect when needed.

[0061] The selected average crystallinity also provides the bacterial cellulose with increased stiffness, particularly compared to plant cellulose and bacterial cellulose in which the crystallinity has not been adjusted or selected accordingly. When bacterial cellulose with a crystallinity of 30% to 80% is ground or pulverized to a selected average particle size of 1 μm to 1000 μm, the resulting particles exhibit a range of irregular shapes, particularly polyhedral and disc-like shapes. The irregular shape helps increase the particle's surface area to mass ratio, which increases its oil absorption capacity.

[0062] Advantageously, the irregular shape created by the mixture of crystalline and amorphous phases in the particles further enhances the powder's light-scattering ability. This allows them to act as excellent sunscreens. When used in paints, makeup, or skincare products, the light scattering helps achieve the desired soft, matte finish.

[0063] To their credit, the inventors discovered that by selecting one or more suitable bacterial species and adjusting culture conditions, the ratio of crystalline to amorphous phases in bacterial cellulose can be finely tuned. They also discovered that the speed, frequency, and duration of agitation, as well as aeration, play a significant role. Combined with a selected drying technique, the degree of crystallinity can be more precisely adjusted. By setting the crystallinity within a defined range, absorption and matte effects can be optimized.

[0064] "Particle size" in the sense of the present invention is preferably the diameter of a theoretical equivalent sphere occupying a volume equal to the volume occupied by the particle. Those skilled in the art are aware of methods for calculating or estimating an equivalent sphere.

[0065] In the sense of the present invention, the "average particle size" is preferably the median diameter of a plurality of particles. Unless otherwise stated, this is preferably D 50 The average particle size is the particle size at which the cumulative percentage of ordered particles reaches 50%. That is, a D of 500 μm 50 The average particle size preferably means that 50% of the particles have a diameter greater than 500 μm and 50% of the particles have a diameter less than 500 μm. 50 The average particle size can be determined by microscopic image analysis, differential sieving, light scattering or other methods. 50 The average particle size is determined by polarized intensity differential scattering, specifically using a ULM standard PIDS instrument.

[0066] In a further preferred embodiment of the present invention, the micropowder is produced by a method comprising grinding a bacterial cellulose film and drying the ground bacterial cellulose. Initially forming bacterial cellulose particles by grinding can produce a homogeneous mixture or powder. The mixture or powder may contain irregularly shaped particles due to breakage in the grinder, as well as particles of small size. Particle size can be further adjusted by drying.

[0067] In some embodiments, drying may preferably be configured to cause keratinization of the bacterial cellulose.

[0068] For the purposes of the present invention, "keratinization" is preferably a phenomenon that occurs in cellulosic materials during drying or water removal, causing the cellulose microfibrils to aggregate, increasing their density and strength. The hydrogen bonds formed between the aggregated microfibrils are preferably strong enough so that they are not broken by rewetting the cellulose. Consequently, keratinized bacterial cellulose will not swell substantially when immersed in liquid formulations. Furthermore, entanglement of cellulose chains during the drying process may further promote keratinization. At the same time, keratinization blocks chemical groups in the cellulose chains, increasing the hydrophobicity of the produced bacterial cellulose particles.

[0069] Hornification preferably reduces the swelling ability and wet flexibility of bacterial cellulose (Wenxuan Mo, Kefu Chen, Xuan Yang, Fangong Kong, Jiangyan Liu, Bo Li, Elucidating the hornification mechanism of cellulosic fibers during the process of thermal drying, Carbohydrate Polymers, Volume 289, 2022, 119434, ISSN 0144-8617). Hornification is known to prevent substances from gelling (Minor, JL (1994). "Hornification, its origin and meaning," Progress in Paper Recycling 3 (2), 93-95. DO1 10.1007 / s00226-003-0216-2). Therefore, hornified bacterial cellulose is preferably not a gelling material. In addition, hornification can increase the crystallinity of bacterial cellulose, thereby improving its mechanical strength (Newman, RH Carbon-13 NMR evidence for cocrystallization of cellulose as a mechanism for hornification of bleached kraft pulp. Cellulose 11, 45-52 (2004)).

[0070] Drying methods that can induce cornification of bacterial cellulose include oven drying and spray drying. The presence and extent of cornification depends not only on the drying method, but also on the drying temperature, drying duration, and the parameters used to agitate or aerate the dried material (if any).

[0071] In a further embodiment of the present invention, a drying method may be preferably selected to induce and / or increase keratinization. An example of such a method is oven drying. Surprisingly, it has been found that oven drying a fluid suspension containing ground bacterial cellulose can increase the hydrophobicity of the bacterial cellulose particles, resulting in a very high oil absorption capacity. The oil absorption capacity of the micropowder produced by oven drying is higher than that of the micropowder produced using freeze drying. Preferably, the drying temperature is up to 250°C, preferably up to 160°C, preferably 150°C, more preferably up to 120°C, even more preferably up to 100°C, even more preferably up to 80°C, and even more preferably up to 40°C. At these temperatures, keratinization of the bacterial cellulose can be achieved without the risk of thermal decomposition of the bacterial cellulose. The duration of drying can be adjusted so that substantially all of the water is removed from the bacterial cellulose. Oven drying is preferably performed for a period of 12 hours to 10 days, preferably for a period of 12 hours to 72 hours, and more preferably for a period of 20 hours to 28 hours.

[0072] During oven drying, the BC can be arranged horizontally or vertically. The drying temperature and duration can be adjusted to enhance the porosity of the BC powder. Generally, slow oven drying at relatively low temperatures has been found to achieve the optimal level of cornification while also allowing for the development of porosity due to moisture escape.

[0073] In a further embodiment of the present invention, a microwave oven is used to dry the bacterial cellulose. This drying mechanism has been found to effectively increase cornification in a uniform manner while being rapid and energy-efficient. Furthermore, the rapid boiling and release of water from the bacterial cellulose mixture is believed to increase porosity and / or enhance the stiffness of the cellulose.

[0074] In a further preferred embodiment of the present invention, spray drying is used to dry the fluid suspension containing the ground bacterial cellulose. Air flow during the spray drying process can reduce keratinization of the bacterial cellulose fibers and loosen them. To address this issue, it is preferred to use a higher temperature during the spray drying process to dry the bacterial cellulose. Specifically, a temperature of at least 180°C, preferably at least 200°C, and more preferably at least 250°C or higher is preferred.

[0075] In a further preferred embodiment of the present invention, the surface area to mass ratio of the micropowder is at least 2 m 2 / g, preferably at least 5m 2 / g, more preferably at least 10m 2 / g, more preferably at least 20m 2 / g, more preferably at least 25m 2 / g, more preferably at least 30m 2 / g, more preferably at least 35m2 / g, more preferably at least 40m 2 / g, more preferably at least 50m 2 / g, more preferably at least 60m 2 / g, more preferably at least 70m 2 / g, even more preferably at least 80m 2 / g. To limit flammability and reactivity, it may be preferred that the surface area to mass ratio does not exceed 100m 2 / g.

[0076] The surface area to mass ratio not only improves dispersibility by increasing the molecular interactions between the micropowder and the medium in which it is held, but also increases the absorption capacity of oil and water. Furthermore, the surface area to mass ratio increases the ability of the bacterial cellulose particles to adsorb and desorb molecules and living cells. This can accelerate the biodegradation of the micropowder. The surface area to mass ratio can be adjusted by setting the speed and / or duration of the bacterial cellulose grinding step.

[0077] Furthermore, the surface area to mass ratio can be increased by treating bacterial cellulose to increase its porosity. The present inventors have discovered that increasing the number of through and blind pores in bacterial cellulose particles can significantly improve the surface area to mass ratio, thereby increasing oil absorption capacity. It is particularly preferred that the bacterial cellulose particles be mesoporous.

[0078] An example of a process that has been found to increase porosity is the culture process itself, in particular when agitation is applied to the culture medium. By examining the effects of different compositions of the culture medium on the morphology of the synthesized cellulose using SEM scanning microscopy, it was shown that the nutrients contained in the microbial matrix also affect the porosity, which is caused by the density of the cellulose fiber network (Molina-Ramírez, C.; Castro, C.; Zuluaga, R.; P.Physical Characterization ofBacterial Cellulose Produced by Komagataeibacter medellinensis Using FoodSupply Chain Waste and Agricultural By-Products as Alternative Low-CostFeedstocks.J.Polym.Environ.2018,26,830–837). In addition, porosity can be increased by adjusting post-treatment processes such as drying processes (Tang, W.;Jia, S.;Jia, Y.;Yang, H.The influence offermentation conditions and post-treatment methods on porosity of bacterial cellulose membrane.World J.Microbiol.Biotechnol.2010,26,125-13131). For example, it was found that spray drying or oven drying can increase the number of pores in bacterial cellulose, with oven drying being particularly preferred.

[0079] In a further preferred embodiment of the present invention, the bacterial cellulose granules have an average crystallinity of between 40% and 80%, preferably between 40% and 60%, and particularly preferably between 40% and 50%. Surprisingly, bacterial cellulose granules with this crystallinity are particularly lightweight and easy to disperse. At the same time, the granules have high porosity and a large specific surface area. The resulting micropowders achieve very high water and oil absorption capacities.

[0080] Bacterial cellulose produced under static culture conditions typically takes the form of one or more aqueous films comprising a network of interconnected fibrils assembled in numerous dense layers. The crystallinity of cellulose and the mechanical properties it imparts to cellulose are the primary factors influencing the layered bacterial cellulose structure formed during biosynthesis (Ruan et al., 2016). Various key parameters of the bacterial fermentation process can be used to control the structural characteristics of the resulting cellulose fibers. Crystallinity can depend on:

[0081] (i) the selected method for culturing cellulose-synthesizing microorganisms (Czaja, W.; Romanovicz, D.; Brown, R.M. Structural investigations of microbial cellulose produced in stationary and agitated culture. Cellulose 2004, 11, 403-411),

[0082] (ii) the type of carbon source and other components of the culture medium (Yim, SM; Song, JE; Kim, HR Production and characterization of bacterial cellulose fabrics by nitrogen sources of tea and carbon sources of sugar. Process Biochem. 2017, 59, 26-3), where Hestrin-Schramm medium was found to be suitable for providing a crystallinity between 30% and 80%, and

[0083] (iii) Drying method used ( A.; Staroszczyk, H.; Szkodo, M. The effect of dehydration / rehydration of bacterial nanocellulose on its tensile strength and physicochemical properties. Carbohydr. Polym. 2020, 236, 1160235). The present inventors found that the crystallinity of bacterial cellulose was slightly higher in the case of oven-based drying or spray drying than during drying or freeze drying by lyophilization. Therefore, the above-mentioned crystallinity can be achieved by adjusting these factors, with oven drying or spray drying being particularly preferred.

[0084] The crystallinity of bacterial cellulose is related to its degree of polymerization. In a preferred embodiment of the present invention, the degree of polymerization of bacterial cellulose is between 1,000 and 20,000. In contrast, the degree of polymerization of plant cellulose is between 10 and 100, which results in a less versatile range of physical properties. Without wishing to be bound by any particular theory, it is believed that a higher degree of polymerization, i.e., the production of longer polymer chains, causes the chains to pack more tightly in the culture and crystallize more easily. On the other hand, when the culture is stirred or agitated, it is believed that the length and packing of the polymer chains are limited by the shear forces present in the fluid medium. This results in a lower degree of polymerization and crystallinity.

[0085] In the sense of the present invention, the "degree of polymerisation" is preferably the average number of monomer units in the polymer chain.

[0086] The degree of polymerization is also related to the porosity of bacterial cellulose particles. During the polymerization process of bacterial cellulose, various types of pores may be formed. These include through pores, blind pores, and closed pores.

[0087] In the sense of the present invention, a "through-pore" is preferably a channel extending through the particle, wherein the channel is open at two different ends. That is, the through-pore is preferably accessible from two different openings in the surface of the bacterial cellulose particle.

[0088] In the sense of the present invention, a "blind hole" is preferably a channel extending at least partially through the particle, wherein the channel is open at only one end. That is, the blind hole is preferably only accessible from a single opening in the surface of the bacterial cellulose particle.

[0089] In the sense of the present invention, "closed pores" are preferably channels which are enclosed within the bacterial cellulose particle and which are not accessible from anywhere on its surface.

[0090] In the sense of the present invention, “mesopores” are preferably through-going, open or closed pores having a diameter between 1 nm and 50 nm.

[0091] Through-holes significantly contribute to the permeability of bacterial cellulose powders, and therefore their water and oil absorption capacity. The large number of through-holes in bacterial cellulose particles can also increase the particle's surface area to volume ratio and surface area to mass ratio, further improving its absorption capacity.

[0092] Blind pores also help increase the particle's surface area to volume ratio and surface area to mass ratio. Therefore, both through and blind pores contribute to the micropowder's absorption, adsorption, and desorption capabilities. The presence of these pores can also improve the micropowder's biodegradability.

[0093] It was found that through-holes and blind pores are particularly favorable for the absorption of sebum from the skin. The heteroatoms (such as oxygen, carbonyl, sulfur, phosphorus or nitrogen) present in cellulose that form functional groups have a relatively strong electronegativity and are attractive to long-chain fatty acids, esters, proteins, lipids, hydrocarbons or drug molecules. Molecular dynamics simulation studies have confirmed that the dry bacterial cellulose surface has a high affinity for oils. The ΔG calculated for vegetable oils is bindThe value is -300 kcal / mol. Sebum (including esters and fatty acids, etc.) is particularly well attracted and absorbed by these bacterial cellulose pores. A larger number of pores or a larger size distribution can increase absorption capacity and fluid flow through them (Burggraaf, AJ & Cot, L. Fundamentals of organic membrane science and technology. 4, (Elsevier, 1996), Joghataei, M., Semnani, D., Salimpour, M.R., Ashrafi, Z. & Khoeini, D. Comparison of heat transfer coefficient for different fabrics by vapor-compression system. Int. J. Eng. Technol. 5, 11-15 (2016)).

[0094] Although closed cells do not directly contribute to the transport of substances through the undegraded particles, they can increase the strength and flexibility of BC while reducing its density.

[0095] It may be preferred that the bacterial cellulose particles have a high percentage of through pores. It may be preferred that at least 20%, at least 30% or at least 40% of the void volume of the particle is located in through pores.

[0096] It may also be preferred that the bacterial cellulose particles have a high total percentage of through and blind pores. It may also be preferred that at least 50%, at least 60%, or at least 70% of the void volume of the particle is located in blind and through pores. This may increase the absorption and adsorption capacity of the micropowder.

[0097] It may also be preferred that the bacterial cellulose particles have a high total percentage of mesopores. It may be preferred that at least 50%, at least 60% or at least 70% of the void volume of the particle is located in the mesopores.

[0098] In a further preferred embodiment of the present invention, the bacterial cellulose granules have a porosity of at least 3%, preferably at least 5%, more preferably at least 10%, even more preferably at least 20%.

[0099] In a further preferred embodiment of the present invention, the porosity of the micropowder is at least 20%, preferably at least 30%, more preferably at least 40%, even more preferably at least 50%.

[0100] In the sense of the present invention, the "porosity" of a particle is preferably the proportion of the volume of the particle that is pores. The "porosity" of a material such as a micropowder is preferably the proportion of the volume of the material that is void. The porosity is preferably given as a percentage. The formula % Porosity = V V / V T ×100 to calculate the percent porosity, where V V is the pore volume, V T is the total volume.

[0101] The percentage porosity and distribution of pore types in bacterial cellulose depend on the density of the cellulose fiber network. It was found that the density of the cellulose fiber network depends on the bacterial culture conditions and the drying technology used (Tang, W.; Jia, S.; Jia, Y.; Yang, H. The influence of fermentation conditions and post-treatment methods on porosity of bacterial cellulose membrane. World J. Microbiol. Biotechnol. 2010, 26, 125-13131). The morphology of bacterial cellulose cultured in different culture medium components was examined using SEM scanning microscopy, indicating that the nutrients contained in the culture medium can affect the porosity (Molina-Ramírez, C.; Castro, C.; Zuluaga, R.; P. Physical Characterization of Bacterial Cellulose Produced by Komagataeibacter medellinensis Using Food Supply Chain Waste and Agricultural By-Products as Alternative Low-Cost Feedstocks. J. Polym. Environ. 2018, 26, 830-837). Porosity is also affected by media agitation and aeration.

[0102] It has also been found that different drying techniques affect the porosity of bacterial cellulose particles (Bruno Thibault, Cristina Ratti, Seddik Khalloufi A mathematical tool for estimating the efficiency of pore formation during dehydration, Journal of Food Engineering, Vol323 2022, 110981). For example, it has been found that reducing the pressure during freeze drying can increase the porosity of many organic materials (Vasiliki P. Oikonomopoulou, Magdalini K. Krokida, Vaios T. Karathanos, The influence of freeze drying conditions on microstructural changes of food products, Procedia Food Science, Volume 1, 2011, Pages 647-654).

[0103] In a further preferred embodiment of the present invention, the bacterial cellulose particles are mesoporous, with an average pore radius of 1 nm to 50 nm, preferably 10 nm to 30 nm, more preferably 5 nm to 20 nm, even more preferably about 7 nm. Preferably, the surface area to mass ratio of the bacterial cellulose particles is 10 m 2 / g to 100m 2 / g, more preferably 10m 2 / g to 80m 2 / g.

[0104] Surface area is preferably the interface through which a solid interacts with its surroundings (especially liquids and gases). Surface area can be generated by reducing particle size (e.g., grinding and milling) and making the material porous. The surface area of ​​a solid material is typically determined by physical adsorption of gases on the solid surface and calculating the amount of adsorbed gas corresponding to a monolayer on the surface. The results of such analysis will be further described herein.

[0105] In a further preferred embodiment of the present invention, the surface of the bacterial cellulose particles exhibits filamentous protrusions similar to microvilli. Such microvilli-like protrusions are observed in bacterial cellulose particles produced by the preferred methods described herein. It may be preferred that at least 2%, more preferably at least 5%, more preferably at least 10%, and even more preferably at least 20% of the surface area of ​​the bacterial cellulose particles is covered by microvilli. This can be identified and quantified due to the distinct texture of the covered areas within the microvilli, as demonstrated herein with reference to scanning electron microscopy images.

[0106] Without being limited by theory, it is believed that these microvilli-like protrusions increase the oil and water absorption capacity of the bacterial cellulose particles by increasing the surface area to mass ratio. Molecular dynamics simulations have shown that bacterial cellulose fibers have a high affinity for saturated hydrocarbon molecules, especially in dry form, and will be published elsewhere. For common oils such as glycerol and vegetable oil, ΔG was calculated. bind The free binding energy of the microfibrils is between -50 kcal / mol and -300 kcal / mol. It is believed that this characteristic of bacterial cellulose microfibrils can be utilized to significantly improve the oil absorption of the micropowder by exposing such microprotrusions on the surface of bacterial cellulose particles.

[0107] In the sense of the present invention, "microvilli-like protrusions" are preferably elongated protrusions from the surface of the bulk material, preferably comprising fibers arranged approximately parallel to the plane formed by the bulk material surface. The protrusions may, for example, have a diameter significantly smaller than 1 μm, preferably smaller than 100 nm, and an aspect ratio greater than 5, preferably greater than 10.

[0108] In the sense of the present invention, a "particle" is preferably a discrete portion of material with well-defined boundaries in all directions. Preferably, the particle has a mass of less than 1 gram and / or a maximum dimension of at most 5 mm, preferably at most 1000 μm. Particles are preferably distinguished from fibers in that their aspect ratio is less than 50:1, more preferably less than 20:1, and even more preferably less than 10:1. In a further preferred embodiment of the present invention, the average aspect ratio of the bacterial cellulose particles is less than 10:1, preferably less than 5:1, and more preferably less than 2:1.

[0109] In the sense of the present invention, the "aspect ratio" of a particle is preferably the ratio of its largest dimension to its shortest dimension. It may be preferred that the aspect ratio is the Feret's aspect ratio determined based on the Feret's diameter, in particular for polyhedral, spherical, disc-shaped, plate-shaped, ellipsoidal or spherical particles. Preferably, the Feret's aspect ratio is the ratio of the maximum Feret's diameter to the minimum Feret's diameter of the particle. The maximum Feret's diameter is preferably the maximum distance between two parallel tangents of the particle at any possible angle. The minimum Feret's diameter is preferably the minimum distance between two parallel tangents of the particle at any possible angle. The maximum and minimum Feret's diameters can be determined by microscopy and / or using computer-based analysis software.

[0110] At lower aspect ratios, bacterial cellulose particles tend to be more spherical. Such particles have been found to be less likely to aggregate and form networks than needle- or rod-shaped particles. Consequently, despite low residual moisture content, micropowders are more stable and have a longer shelf life. When suspended, bacterial cellulose particles with low aspect ratios form a stable suspension without forming an unnecessary colloidal gel. This allows for the easy spreadability of creams or lotions.

[0111] The aspect ratio of particles also affects their optical scattering properties. It has been found that a low aspect ratio scatters light to a lesser extent, giving the product a shinier appearance. This is particularly observed in micropowders with spherical particles.

[0112] In some preferred embodiments of the present invention, the bacterial cellulose particles are polyhedral in shape. Polyhedral particles have been found to scatter light more strongly than spherical particles, allowing consumer products containing the micropowder of this embodiment to leave a more matte finish. Furthermore, polyhedral particles have a greater surface area to mass ratio than spherical particles, further contributing to the micropowder's absorptive capacity.

[0113] In the sense of the present invention, a "polyhedral" particle shape is preferably a three-dimensional shape having a plurality of planar surfaces, wherein adjacent planar surfaces are preferably at an angle to each other. Preferably, the polyhedral particles have at least six planes, more preferably at least eight. It may be preferred that the polyhedral particles have no more than 30 planes, preferably no more than 20 planes.

[0114] In some preferred embodiments of the present invention, the bacterial cellulose particles are plate-shaped. Plate-shaped particles can be packed very tightly and can therefore be used to formulate products with high coverage. This may be particularly advantageous for paints and cosmetics.

[0115] In the sense of the present invention, the term "plate-like" preferably refers to particles having two flat surfaces, wherein the two flat surfaces are preferably approximately parallel to each other.

[0116] In the sense of the present invention, a micropowder wherein the particles have a particular shape is preferably a micropowder wherein at least 50%, more preferably at least 60%, 70% or more of the particles have said shape.

[0117] In a further preferred embodiment of the present invention, the bacterial cellulose micropowder contains no organic solvents. This allows the micropowder to be highly biocompatible and suitable for use on the skin. Because cellulose fibers are somewhat hydrophobic, volatile organic solvents such as ethanol and acetone are sometimes used as carriers during cellulose processing. By eliminating or avoiding these components, a much more skin-friendly micropowder can be produced without the risk of irritation. The micropowder production process can also be made safer and more environmentally friendly.

[0118] Preferably, the micropowder has a moisture content of less than 10 w / w%, preferably less than 7 w / w%, and particularly preferably less than 5 w / w%. Even more preferably, the moisture content is less than 0.5 w / w%. These low moisture contents provide the micropowder with greater stability and shelf life, preventing unwanted particle aggregation. In addition, low moisture content increases the micropowder's absorption capacity, particularly its oil absorption capacity. As is well known, water and oil tend to be immiscible. Reducing the moisture content improves the contact between the micropowder and the oil. Since the pores and outer surfaces of the bacterial cellulose particles do not absorb water, they can instead attract oil particles and retain them through intermolecular forces. As a result, the resulting micropowder exhibits very high absorption properties.

[0119] In a further preferred embodiment of the present invention, the bacterial cellulose particles are non-functionalized. Non-functionalized bacterial cellulose particles naturally possess a certain degree of hydrophobicity, so they can attract oily components released from the skin. Non-functionalized bacterial cellulose particles have also been found to be particularly effective as micropowders in cleaning products, toothpastes, and the like due to their affinity for oils and proteins. Furthermore, such micropowders require fewer chemical processing steps and can enjoy the status of a natural product.

[0120] In a further preferred embodiment of the present invention, the bacterial cellulose particles comprise functionalized cellulose, wherein the functionalized cellulose is preferably functionalized by adding alkyl, acyl, ester, amine, carboxyl, carboxymethyl, phosphorus and / or sulfur, preferably at the C6 position. The functionalization of the bacterial cellulose particles can impart specific properties to the powder, such as hydrophobicity, polarity, amorphism and solubility in different media. For example, carboxylation at C6 can increase the polarity of the bacterial cellulose and make it partially soluble in aqueous media. Therefore, the functionalized powder can be used as a good rheology modifier in liquid products, providing the desired shear thinning effect. Shear thinning is particularly useful for products that are to be easily spread on a surface but can subsequently remain stable. These products include wall paints, mayonnaise, ketchup and skin creams.

[0121] In a further preferred embodiment of the present invention, the micropowder is configured as a pigment. It may be preferred that the bacterial cellulose particles of the micropowder are coated with a dye. It may be preferred that the bacterial cellulose particles are functionalized before being coated with the dye. For example, the bacterial cellulose particles may be carboxylated so that their surfaces have a negative surface charge. The bacterial cellulose particles may then be coated by adsorbing dye molecules with a positive surface charge. Alternatively, the bacterial cellulose particles may be functionalized so that they have a positive surface charge before being coated with a dye with a negative surface charge. The dye may preferably be an organic dye. This micropowder can not only improve the texture and feel of consumer products, but can also fine-tune their color. In particular, in cosmetics such as foundation creams, it is highly desirable that the product color closely matches the user's skin color. This micropowder can provide this color matching function while maintaining safety and biodegradability.

[0122] In a further preferred embodiment of the present invention, the micropowder is configured as a carrier for pharmacologically active molecules. For example, the pharmacologically active molecules may include drug molecules, urea, lipids, or proteins. Preferably, the pharmacologically active molecules are adsorbed on the surface of the bacterial cellulose particles. Such micropowders can be used in particularly safe and biocompatible medical products (e.g., ointments).

[0123] In a further aspect, the present invention relates to a biodegradable powder comprising bacterial cellulose particles, wherein the average particle size D of the bacterial cellulose particles is 50 The bacterial cellulose particles have a diameter between 1 μm and 1000 μm, preferably between 1 μm and 500 μm, more preferably between 5 μm and 250 μm, and even more preferably between 25 μm and 100 μm, and an average crystallinity between 30-80%, preferably between 40-60%. Surprisingly, it has been found that with this combination of parameters, the bacterial cellulose particles have a very high surface area to mass ratio, high porosity, and very high oil absorption capacity. For example, at 25°C, an oil absorption capacity of greater than 5 g / g for sunflower oil can be achieved.

[0124] In a second aspect, the present invention relates to a method for producing micropowder.

[0125] The method comprises the following steps:

[0126] - producing bacterial cellulose from a bacterial culture such that the average crystallinity of the produced bacterial cellulose is between 30% and 80%,

[0127] - Grind the bacterial cellulose to form an average particle size D 50 bacterial cellulose particles of 1 μm to 1000 μm, and

[0128] - Drying the ground bacterial cellulose particles.

[0129] By producing bacterial cellulose from a culture configured to achieve an average crystallinity of 30% to 80%, the bacterial cellulose bulk material comprises a rich mixture of crystalline and amorphous phases. The crystalline phase preferably comprises ordered cellulose chains, which are preferably tightly packed parallel to each other and held together by hydrogen bonds. However, the cellulose chains of the amorphous phase are preferably disordered and bound by weaker intermolecular forces. Hydrogen bonds make the crystalline phases much stiffer than the amorphous phase, so their rupture preferably results in a flat surface rather than a spherical or ellipsoidal one. The result preferably includes polyhedral or plate-like particles. These offer a high surface area to mass ratio and are highly optically scattering, allowing the micropowder to provide a non-greasy feel and matte appearance. At the same time, the mixture of crystalline and amorphous phases can reduce the packing density of the cellulose microfibrils. This can result in a higher porosity in the bacterial cellulose, increasing its oil absorption capacity.

[0130] By grinding bacterial cellulose to an average particle size of 1 to 1000 μm, a powder or suspension of bacterial cellulose particles with a very high surface area to mass ratio can be provided. As a result, the particles are very easy to disperse, forming a stable suspension. Due to this increased surface area to volume ratio, these particles also have strong oil and water absorption properties.

[0131] Drying the ground bacterial cellulose particles releases fluid from their pores and further increases porosity. The drying step further modulates the shape, morphology, and surface energy of the bacterial cellulose particles. During the drying process, the micropowder preferably acquires a shape that can change from approximately spherical to spherical to distorted disc-shaped. Spherical to distorted disc-shaped particles scatter light differently than spheres, resulting in different light scattering effects relevant to some cosmetic applications, such as creating a shiny appearance.

[0132] It has been discovered that the drying step alters the surface energy of bacterial cellulose particles, thereby improving formulation and sensory experience. Typically, the surface of micropowders and microbeads must be modified to make them compatible with various cosmetic formulations. To aid cosmetic formulation, provide functional properties, and enhance the aesthetic experience, known starch and silica microbeads often undergo various surface treatments. Surprisingly, it has been discovered that drying and grinding bacterial cellulose can increase its hydrophobicity and affinity for oils, making it suitable for use in lotions and oil-based creams. The micropowder also exhibits a surprisingly high oil absorption capacity compared to known micropowders.

[0133] Furthermore, dry-milled bacterial cellulose provides micropowders that are free of organic solvents, have low moisture content, and have a long shelf life.

[0134] Preferably, the drying step is performed under sterile conditions.

[0135] In the sense of the present invention, the average "crystallinity" of a material is preferably a percentage of the total volume of the material that is crystalline.

[0136] In the sense of the present invention, a "grinding" step is preferably a process of breaking up bulk material into particles and is also referred to herein as crushing, milling, pulverizing or homogenizing. Purely by way of example, grinding can be performed in a colloid mill.

[0137] In the sense of the present invention, a "drying" step is preferably a process in which water is separated from a solution, suspension or water-containing solid by applying a change in temperature and / or pressure. Preferably, the temperature change comprises boiling, freezing and / or sublimation of the water. Preferably, the pressure change comprises reducing the pressure in the system, in particular by applying a vacuum to reduce the boiling point or sublimation point of the water.

[0138] In a preferred embodiment of the present invention, during the step of producing bacterial cellulose from the bacterial culture, the bacterial culture is agitated and / or stirred. It has been found that agitating the bacterial cellulose culture limits crystallinity and can therefore be used to adjust the balance of the crystalline and amorphous phases. Agitation can preferably be carried out at 5 rpm to 250 rpm (revolutions per minute), more preferably at 100 rpm to 200 rpm.

[0139] In a preferred embodiment of the present invention, the bacterial cellulose is washed before grinding, and deionized water can be used for washing.

[0140] In a further preferred embodiment of the present invention, the bacterial cellulose is at least partially dried between production and grinding, wherein the partial drying is preferably carried out in an atmosphere with a relative humidity of up to 85%, preferably up to 80%, and a temperature between 20°C and 40°C, preferably between 25°C and 35°C, for a period of 3 to 10 days, preferably 5 to 9 days.

[0141] By at least partially drying the bacterial cellulose, the cultivation process can be terminated and the bacterial cellulose can be ground without a culture medium. The efficiency of the grinding process can be improved.

[0142] In a further preferred embodiment of the present invention, the bacterial cellulose is treated with liquefied gas (preferably liquid nitrogen) prior to grinding. Treatment with liquefied gas rapidly reduces the temperature of the bacterial cellulose, increasing its brittleness and creating cracks in the crystal structure, which is believed to increase the porosity and irregularities of the resulting bacterial cellulose particles. In particular, when grinding is performed within 30 minutes of treatment with liquefied gas, the bacterial cellulose particles adopt a polyhedral shape, which helps increase the surface area to mass ratio of the micropowder.

[0143] It may be preferred that the grinding step comprises multiple grinding cycles. The multiple grinding cycles may correspond to different degrees of roughness, so that the bacterial cellulose particles are gradually reduced in size. This allows the use of different grinders specifically designed to produce different particle sizes, thereby increasing the efficiency of the production process. Preferably, the multiple grinding cycles may be separated by treatment with liquefied gas.

[0144] In a further preferred embodiment of the present invention, the ground bacterial cellulose particles are dried by freeze drying, oven drying, spray drying, supercritical CO treatment or a combination thereof. It has been found that these drying methods are particularly suitable for achieving low moisture content in the bacterial cellulose and provide the bacterial cellulose particles with sufficient surface energy, thereby having strong oil absorption. In addition, it is preferred to increase the keratinization of the bacterial cellulose by methods such as spray drying or especially oven drying. This can provide the desired porosity while preventing the bacterial cellulose particles from expanding in a fluid formulation.

[0145] In a further preferred embodiment of the present invention, the ground bacterial cellulose particles are mixed with deionized water before drying to form a suspension of bacterial cellulose in water having a concentration of 0.5 w / w% to 5 w / w%, more preferably 1.0 w / w% to 3.5 w / w%.

[0146] By suspending ground bacterial cellulose in water, a suspension with high chemical purity can be formed without the use of organic solvents. The resulting micropowder is particularly safe and suitable for use on sensitive skin and in pharmaceutical products. Furthermore, the absence of trace salts in deionized water preserves the micropowder's low polarity and high lipophilicity. At the selected concentration, the suspension is stable and aggregation of suspended particles is avoided, making it particularly suitable for atomization.

[0147] In a further preferred embodiment of the present invention, a suspension of bacterial cellulose in water is spray dried, wherein the spray drying preferably comprises the following steps:

[0148] - atomizing said suspension of bacterial cellulose in water to form droplets suspended in a gas, wherein said atomization is preferably assisted by using a pressurized gas, in particular air or an inert gas, particularly preferably nitrogen,

[0149] - subjecting the suspended droplets to a stream of heated air, such that the water content of the droplets is reduced, the heated air preferably having a temperature between 80° C. and 250° C., particularly preferably between 150° C. and 190° C., and more particularly between 170° C. and 190° C.,

[0150] - Collect the dried granules.

[0151] Spray drying the suspension provides fine particles with a controlled size distribution and high purity. Keratinization, which occurs during drying at higher, preferred temperatures, further enhances the chemical stability of the micropowder and its hydrophobicity, while keeping the interstices in the bacterial cellulose open for absorption and adsorption.

[0152] Spray drying is preferably carried out in a drying chamber. In some preferred embodiments of the present invention, spray drying is carried out by pumping the suspension into a drying chamber, pumping heated air into the drying chamber at a volume flow rate of 500 NL / h to 700 NL / h (standard liters / hour) and sucking the air out of the drying chamber.

[0153] The heated air entering the drying chamber preferably has a relative humidity of up to 30%, more preferably up to 20%. The relative humidity of the inhaled air is preferably 35% or higher. The air flow evaporates the water in the falling droplets, thereby forming solid particles as the droplets traverse their downward trajectory through the drying chamber.

[0154] In a further preferred embodiment of the present invention, the atomization of the bacterial cellulose suspension in water is achieved with the aid of a pressurized gas, in particular nitrogen. Using this atomization method, very fine particles with an average diameter of down to 300 nm can be produced.

[0155] In a further preferred embodiment of the present invention, the dried particles are collected using an electrostatic particle separator. Depending on the functional groups present on their surface, the surface charge of the bacterial cellulose particles can be positive or negative. The magnitude of the charge can depend on the size of the particles. The electrostatic particle separator can be used to collect particles within a predetermined size range, resulting in micropowders with a finely controlled particle size distribution. The electrostatic particle separator can also be used to increase the yield of the drying process. When collecting particles via electrostatic particle separation, yields of up to 90% have been achieved, compared to 60% to 70% using conventional methods.

[0156] In a further preferred embodiment of the present invention, the suspension of bacterial cellulose in water is oven dried. Preferably, the drying temperature is up to 250°C, preferably up to 160°C, preferably 150°C, more preferably up to 120°C, even more preferably up to 100°C, even more preferably up to 80°C, even more preferably up to 40°C. In a preferred embodiment, the suspension is preferably placed in a hot air circulating oven dryer at 80°C to 160°C, preferably 90°C to 120°C, for a period of 12 to 72 hours, preferably 20 to 28 hours.

[0157] In a further preferred embodiment of the present invention, the suspension of bacterial cellulose in water is freeze-dried, wherein the freeze-drying preferably comprises the following steps:

[0158] - freezing the suspension at a temperature between -10°C and -50°C, preferably between -15°C and -25°C,

[0159] - reducing the pressure of the controlled atmosphere surrounding the frozen suspension to less than 50 mbar, preferably less than 1 mbar, more preferably less than 0.5 mbar, even more preferably less than 0.2 mbar, so that ice from the frozen suspension sublimes and the moisture content of the resulting agglomerate is less than 7 w / w%, preferably less than 5 w / w%, particularly preferably less than 1 w / w%.

[0160] Freeze-drying a suspension of bacterial cellulose in water was found to increase porosity and reduce crystallinity, thus providing a promising approach for tailoring the material properties of bacterial cellulose particles after cultivation.

[0161] In a further preferred embodiment of the present invention, the agglomerates resulting from the freeze-drying process are subjected to a further grinding step. The grinding step preferably comprises comminuting the agglomerates into a fine powder, in particular using a mixer-cutter.

[0162] In a further preferred embodiment of the present invention, the dried bacterial cellulose particles are separated according to their particle size by a particle separation module, so that the obtained micropowder comprises an average diameter D 50 Bacterial cellulose particles between 1 μm and 500 μm, preferably between 5 μm and 250 μm, particularly preferably between 25 μm and 100 μm, and at least 90% of the bacterial cellulose particles have a diameter of not more than 500 μm, preferably not more than 300 μm, particularly preferably not more than 200 μm.

[0163] The particle separation module allows for fine-tuning of the average diameter and size distribution of micropowders. At the selected particle size, micropowders exhibit highly favorable absorption properties. These are believed to be at least partially due to the high surface area to mass ratio of micropowders of the selected particle size. Micropowders are also found to have superior texture and coverage qualities, particularly in the cosmetics industry.

[0164] In a further preferred embodiment of the present invention, the particle separation module comprises:

[0165] - one or more vibrating screens,

[0166] - inertial separators, in particular settlers,

[0167] - centrifugal separators, in particular cyclone separators,

[0168] - electrostatic separators,

[0169] or a combination thereof.

[0170] In a further preferred embodiment of the present invention, all equipment is sterilized before being used for producing micropowders.

[0171] Micropowder of the present invention can be preferably used in consumer product compositions, particularly in cosmetics, personal care products, food, cleaning products, paints or coatings.Preferred examples of cosmetics and personal care products that can use micropowder include creams, emulsions, foams, gels, lotions, milk, mousse, solutions, sticks, creams, pastes, powders (in bulk or compressed), cream cosmetics, sprays or suspensions.Cosmetics can preferably be any color cosmetics for skin, hair, eyes or lips, such as concealer sticks, foundation (wet or dry), stage makeup, mascara (block or paste), eye shadow (liquid, paste, powder, stick, compressed or paste), hair dye, lipstick, lip gloss, smoky eyeliner (kohl pencils), eyeliner, blush, eyebrow pencil and powder cream.Other exemplary cosmetic compositions include nail polish, skin gloss sticks, spray hair spray, powder, leg modification cosmetics, insect repellent lotion, nail polish remover, perfume emulsion and all types of shampoo (gel or liquid). In addition, micro powders can also be used in shaving creams (aerosol concentrate, brush-free, foaming), hair care products, cologne sticks, cologne, cologne lotion, bubble bath, body lotion (moisturizing, cleansing, analgesic, astringent), aftershave lotion, after-bath lotion and sunscreen lotion.

[0172] In a further aspect, the present invention relates to a cosmetic or personal care product comprising the micropowder of the present invention. The cosmetic or personal care product is preferably a skin care product, including, for example, anti-aging products, treatment products for oily and acne-prone skin, facial masks, moisturizers, butter creams, lotions, BB creams, primers, glossing serums, day creams, night creams, or sunscreens; color cosmetics, including, for example, foundations, concealer products, loose or pressed powders, mascara, lipstick, or lip gloss; hair care products, including, for example, liquid shampoo, dry shampoo, shampoo bars, hair masks, conditioners, or hair styling products; or toiletries, including, for example, antiperspirants, deodorants, or oral care products.

[0173] The micropowders of the present invention have been found to surprisingly improve the performance, pH insensitivity, viscosity and appearance of the above-mentioned products, in particular cosmetic, cosmeceutical or personal care products such as BB creams, primers, brightening serums, day creams, night creams or sunscreens.

[0174] In the case of cosmetic or personal care products, it may be preferred that the concentration of the micropowder in the formulation is from 0.5 w / w% to 50 w / w%, more preferably from 0.5 w / w% to 30 w / w%.

[0175] Advantageously, the micropowders of the present invention can be used in various standard formulations of cosmetic or personal care products to improve product performance. In particular, the micropowders of the present invention can be used to replace known absorbent powders, texturizing agents, or sensory enhancers, such as synthetic polymers or mineral powders, while still providing significantly improved performance. The micropowders of the present invention can preferably be used to replace known absorbent powders in known formulations in similar or lesser amounts.

[0176] In a preferred embodiment of the present invention, the cosmetic or personal care product comprises a fluid formulation comprising 1 w / w% to 50 w / w% of micropowder, 1 w / w% to 90 w / w% of solvent, 1 w / w% to 10 w / w% of wetting agent, 0.1 w / w% to 10 w / w% of rheology modifier, 0.1 w / w% to 30 w / w% of emollient and 0.1 w / w% to 30 w / w% of emulsifier. It may be preferred that the formulation further comprises an antioxidant, a preservative, a fragrance, a pigment, a structuring agent, a pH adjuster, a stabilizer, a binder, a filler and / or a surfactant.

[0177] In a further preferred embodiment of the present invention, the cosmetic or personal care product comprises a solid formulation, which in turn comprises 1 w / w% to 50 w / w% of micropowder, 1 w / w% to 50 w / w% of binder and 1 w / w% to 90 w / w% of filler. Optionally, the solid formulation may also comprise pigments, fragrances, surfactants, conditioners, emollients, structurants, lake dispersants, pearlescent agents, antioxidants and / or preservatives. In a further preferred embodiment of the present invention, the cosmetic or personal care product is an emulsion for use on the body or face. The emulsion preferably comprises:

[0178] -55 w / w% to 85 w / w% solvent,

[0179] -1 w / w% to 10 w / w% wetting agent,

[0180] - 0.1 w / w% to 1 w / w% thickener,

[0181] - 0.5 w / w% to 5 w / w% of the micropowder of the present invention,

[0182] - 2 w / w% to 20 w / w% of an emollient, in particular comprising one or more oils,

[0183] - 1 w / w% to 10 w / w% emulsifier,

[0184] - 0.1 w / w% to 3 w / w% of antioxidants, especially tocopherol,

[0185] - 0.1 w / w% to 3 w / w% of preservatives, in particular EUXYL PE 9010, and

[0186] - 0.1 w / w% to 3 w / w% of fragrances, especially essential oils,

[0187] The w / w % fractions are related to the total weight of the emulsion and the sum of the w / w % fractions is less than or equal to 100%.

[0188] In a further preferred embodiment of the present invention, the cosmetic or personal care product is an emulsion for use on the body or face. The emulsion preferably comprises approximately:

[0189] -76 w / w% solvent, especially water,

[0190] -5w / w% of a wetting agent, especially glycerol,

[0191] - 0.2 w / w% thickener, especially xanthan gum,

[0192] -1.5w / w% of the micropowder of the present invention,

[0193] - 10 w / w % of an emollient, in particular comprising one or more oils,

[0194] -5.5w / w% emulsifier,

[0195] -0.5w / w% antioxidants, especially tocopherol,

[0196] - 1 w / w% of preservatives, in particular EUXYL PE 9010, and

[0197] -0.25w / w% fragrance, especially essential oils,

[0198] The pH of the emulsion is preferably about 6.9. Preferably, the viscosity of the emulsion is about 24,600 cP, particularly when measured 24 hours after the emulsion is produced and at 26° C. The viscosity of the emulsion of the present invention is significantly higher than an emulsion of the same formulation but using a synthetic petroleum-based polymer powder (17,866 cP) and a silica-based powder (18,567 cP) instead of the powder of the present invention.

[0199] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a mascara. The mascara preferably comprises:

[0200] -1 w / w% to 7 w / w% wetting agent,

[0201] - 0.1 w / w% to 3 w / w% rheology modifier,

[0202] -30 w / w% to 80 w / w% solvent,

[0203] - 3w / w% to 30w / w% pigment,

[0204] - 2 w / w% to 20 w / w% structurant,

[0205] -2w / w% to 20w / w% emulsifier,

[0206] - 0.5 w / w% to 10 w / w% of the micropowder of the present invention,

[0207] - 0.5 w / w% to 3 w / w% of preservatives,

[0208] - 0.01 w / w% to 3 w / w% of antioxidant, and optionally

[0209] - pH adjusters, especially sodium hydroxide,

[0210] The w / w % fractions are related to the total weight of the emulsion and the sum of the w / w % fractions is less than or equal to 100%.

[0211] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a mascara. The mascara preferably comprises approximately:

[0212] - 3 w / w% of a wetting agent, in particular propylene glycol,

[0213] - 0.3 w / w% of rheology modifier, especially xanthan gum,

[0214] -60w / w% solvent, especially water,

[0215] -9w / w% pigments, especially black pigments,

[0216] - 12 w / w % of structurants, in particular comprising 8 w / w % of beeswax and 4 w / w % of carnauba wax relative to the final product,

[0217] - 8 w / w% of emulsifiers, in particular comprising 3 w / w% of cetearyl alcohol and 5 w / w% of stearic acid relative to the final product,

[0218] -2w / w% of the micropowder of the present invention,

[0219] - 1 w / w% of preservatives, in particular EUXYL PE 9010,

[0220] - 0.05 w / w% of antioxidants, in particular tocopherol, and optionally

[0221] - pH adjusters, especially sodium hydroxide.

[0222] The mascara preferably has a pH of about 7 and a viscosity of about 434,000 cP, particularly when measured at 25°C 24 hours after mascara production. It has been found that micropowder significantly enhances the volume and length of the mascara, which is believed to be due, at least in part, to a broad particle size distribution.

[0223] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a loose powder. The loose powder preferably comprises:

[0224] -5w / w% to 40w / w% pigment,

[0225] -1 w / w% to 50 w / w% of the micropowder of the present invention,

[0226] -5w / w% to 35w / w% binder,

[0227] -5 w / w% to 25 w / w% filler, and optionally

[0228] - 0.1 w / w% to 5 w / w% of fragrance,

[0229] wherein the w / w % fractions are relative to the total weight of the emulsion and the sum of the w / w % fractions is less than or equal to 100%.

[0230] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a loose powder. The loose powder preferably comprises approximately:

[0231] - 10 w / w% to 30 w / w% of pigments, especially titanium dioxide,

[0232] -20 w / w% to 50 w / w% of the micropowder of the present invention,

[0233] - 5 w / w% to 35 w / w% of a binder, in particular magnesium stearate,

[0234] - 5 w / w% to 25 w / w% of fillers, especially talc,

[0235] - 5 w / w% to 25 w / w% of additional pigments, and optionally

[0236] -1 to 20 drops of fragrance, especially essential oils.

[0237] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a liquid foundation. The liquid foundation preferably comprises:

[0238] - 1 w / w% to 30 w / w% emulsifier,

[0239] - 1 w / w% to 20 w / w% emollient,

[0240] -1w / w% to 15w / w% pigment,

[0241] - 0.05 w / w% to 5 w / w% thickening wax,

[0242] - 0.5 w / w% to 5 w / w% of stabilizer,

[0243] -1 w / w% to 10 w / w% wetting agent,

[0244] -40 w / w% to 80 w / w% solvent,

[0245] - 0.5 w / w% to 25 w / w% of the micropowder of the present invention,

[0246] - 0.1 w / w% to 5 w / w% antioxidant, and

[0247] - 0.5 w / w% to 3 w / w% of preservatives,

[0248] The w / w % fractions are related to the total weight of the emulsion and the sum of the w / w % fractions is less than or equal to 100%.

[0249] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a liquid foundation. The liquid foundation preferably comprises approximately:

[0250] - 15 w / w% of emulsifiers, in particular 4 w / w% of polyglyceryl-3-polyricinoleate (PGPR) and 8 w / w% of caprylic acid, 2 w / w% of cetearyl alcohol and 1 w / w% of Emulsan II relative to the final product,

[0251] - 10 w / w% emollient, especially sunflower oil,

[0252] - 4.65 w / w% of pigments, in particular 0.35 w / w% of red pigment, 0.10 w / w% of black pigment, 0.70 w / w% of yellow pigment and 3.50 w / w% of titanium dioxide, relative to the final product,

[0253] - 0.75 w / w % of a first thickener wax, in particular carnauba wax,

[0254] - 0.25 w / w% of a second thickener wax, in particular xanthan gum,

[0255] -1.5w / w% stabilizer, especially magnesium sulfate,

[0256] - 3 w / w% of a wetting agent, especially glycerol,

[0257] - 61 w / w % to 63 w / w % of a solvent, in particular water,

[0258] -1.5w / w% of the micropowder of the present invention,

[0259] - 0.5 w / w% of antioxidants, especially tocopherol, and

[0260] - 1 w / w% of preservatives, in particular EUXYL PE 9010.

[0261] It may be preferred that the liquid foundation of the present invention has a pH of about 6.35 and a viscosity of 33,000 cP, especially after 24 hours of production at 26° C. It is noteworthy that the viscosity of the liquid foundation of the present invention is significantly higher than that of the liquid foundation using synthetic petroleum-based polymer powder instead of the powder of the present invention.

[0262] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a butter cream. The butter cream preferably comprises:

[0263] -40 w / w% to 80 w / w% solvent,

[0264] -1 w / w% to 20 w / w% wetting agent,

[0265] - 0.1 w / w% to 20 w / w% of the micropowder of the present invention,

[0266] - 0 w / w% to 5 w / w% rheology modifier,

[0267] -5 w / w% to 20 w / w% emulsifier,

[0268] -5w / w% to 30w / w% emollient,

[0269] - 0.01 w / w% to 5 w / w% of fragrance,

[0270] - 0.5 w / w% to 3 w / w% antioxidants, especially vitamin E, and

[0271] - 0.01 w / w% to 3 w / w% of preservatives, in particular Biogard 221,

[0272] The w / w % fractions are related to the total weight of the emulsion and the sum of the w / w % fractions is less than or equal to 100%.

[0273] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a butter cream. The butter cream preferably comprises approximately:

[0274] - 61 w / w % to 64 w / w % of a solvent, in particular water,

[0275] -5w / w% of a wetting agent, especially glycerol,

[0276] - 0.2 w / w% to 1 w / w% of the micropowder of the present invention,

[0277] - 0 w / w% to 1 w / w% of rheology modifiers, in particular xanthan gum,

[0278] - 10 w / w% of emulsifiers, in particular comprising 4 w / w% of Emulsan II and 6 w / w% of cetearyl alcohol relative to the final product,

[0279] - 20 w / w% emollient, especially sunflower oil,

[0280] -1w / w% of fragrance, especially essential oils,

[0281] -0.5 w / w% antioxidants, especially vitamin E, and

[0282] - 0.2 w / w % of a preservative, in particular Biogard 221.

[0283] The essential oils used preferably include one or more of methyl glucose sesquistearate, lavender essential oil, orange essential oil, dehydroacetic acid and / or benzyl alcohol.

[0284] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a lipstick. The lipstick preferably comprises:

[0285] - 5 w / w% to 50 w / w% of a structurant,

[0286] -4w / w% to 80w / w% emollients,

[0287] -1 w / w% to 20 w / w% of the micropowder of the present invention,

[0288] - 0.5 w / w% to 5 w / w% of lake dispersant,

[0289] - 0.1 w / w% to 3 w / w% pearlescent agent,

[0290] - 1 w / w% to 15 w / w% of one or more pigments,

[0291] - 0.01 w / w% to 3 w / w% of an antioxidant, and

[0292] - 0.01 w / w% to 3 w / w% of preservatives,

[0293] The w / w % fractions are related to the total weight of the emulsion and the sum of the w / w % fractions is less than or equal to 100%.

[0294] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a lipstick. The lipstick preferably comprises approximately:

[0295] - 27.5 w / w % of structurants, in particular comprising 11.5 w / w % of synthetic wax, 2 w / w % of euphorbia cerifera wax and 14 w / w % of tricyclodecyl methyl isononanoate, relative to the final product,

[0296] - 62 to 63 w / w% emollients, in particular including 30.5 w / w% seed oil relative to the final product,

[0297] -4w / w% of the micropowder of the present invention,

[0298] - 2 w / w% of lake dispersants, in particular hydrogenated polydecene and polyhydroxystearic acid,

[0299] -0.7w / w% pearlescent agents, especially mica and iron oxides,

[0300] - 6 w / w% to 7 w / w% of one or more pigments,

[0301] - 0.1 w / w% of antioxidants, especially tocopherol, and

[0302] - 0.75 w / w% of preservatives, specifically caprylyl glycol and phenoxyethanol.

[0303] Using the micropowders of the present invention, it is possible to provide a matte or semi-matte lipstick with soft sensory properties.

[0304] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a hand cream. The hand cream preferably comprises:

[0305] -40 w / w% to 80 w / w% solvent,

[0306] -1 w / w% to 10 w / w% wetting agent,

[0307] - 0.1 w / w% to 3 w / w% thickener,

[0308] - 0.5 w / w% to 10 w / w% of the micropowder of the present invention,

[0309] - 3 w / w% to 10 w / w% emulsifier,

[0310] -5w / w% to 30w / w% emollient,

[0311] - 0.1 w / w% to 10 w / w% of fragrance,

[0312] - 0.1 w / w% to 3 w / w% antioxidant, and

[0313] - 0.1 w / w% to 3 w / w% of preservatives,

[0314] The w / w % fractions are related to the total weight of the emulsion and the sum of the w / w % fractions is less than or equal to 100%.

[0315] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a hand cream. The hand cream preferably comprises approximately:

[0316] - 69 w / w% to 72 w / w% solvent, especially water,

[0317] -5w / w% of a wetting agent, especially glycerol,

[0318] - 0.2 w / w% thickener, especially xanthan gum,

[0319] -1 w / w% to 3 w / w% of the micropowder of the present invention,

[0320] - 6 w / w% of emulsifiers, in particular 1 w / w% of Emulsan II and 5 w / w% of cetearyl alcohol, relative to the final product,

[0321] -15w / w% emollients, especially sunflower oil,

[0322] -1w / w% of fragrance, especially essential oils,

[0323] -0.5w / w% antioxidants, especially vitamin E, and

[0324] - 0.2 w / w% of preservatives, in particular EUXYL PE 9010.

[0325] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a lipstick. The lipstick preferably comprises:

[0326] -40 w / w% to 80 w / w% solvent,

[0327] -1 w / w% to 10 w / w% wetting agent,

[0328] - 1 w / w% to 10 w / w% rheology modifier,

[0329] -1 w / w% to 20 w / w% of the micropowder of the present invention,

[0330] -5w / w% to 30w / w% emulsifier,

[0331] -1w / w% to 10w / w% pigment,

[0332] -0.1w / w% to 10w / w% active ingredient,

[0333] - 1 w / w% to 30 w / w% emollient, and

[0334] - 0.1 w / w% to 3 w / w% of preservatives,

[0335] The w / w % fractions are related to the total weight of the emulsion and the sum of the w / w % fractions is less than or equal to 100%.

[0336] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a lipstick. The lipstick preferably comprises approximately:

[0337] - 66 w / w % to 67 w / w % of a solvent, in particular water,

[0338] - 6 w / w% of a wetting agent, especially glycerol,

[0339] - 2.5 w / w% of rheology modifier, especially tapioca starch,

[0340] -1.5w / w% of the micropowder of the present invention,

[0341] - 13 w / w% of emulsifiers, in particular 11% w / w% of cetearyl alcohol and 2 w / w% of caprylic glyceryl, relative to the final product,

[0342] - 2w / w% of pigments, specifically jojoba oil beads,

[0343] -1.5w / w% of active ingredients, especially D-panthenol,

[0344] - 6.5 w / w% emollients, in particular 0.5 w / w% phytosterol esters (Veganolin), 4 w / w% vegetable oils and 2 w / w% dedraflow 30, relative to the final product,

[0345] -0.25 w / w% preservatives, and

[0346] - 0.2 w / w% tocopherol.

[0347] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a powder shampoo. The powder shampoo preferably comprises:

[0348] - 10 w / w% to 40 w / w% of a surfactant,

[0349] -40w / w% to 65w / w% filler,

[0350] -1 w / w% to 30 w / w% of the micropowder of the present invention,

[0351] - 1 w / w% to 10 w / w% of a texture enhancer other than micropowder,

[0352] - 1 w / w% to 7 w / w% of a conditioning agent,

[0353] - 0.1 w / w% to 3 w / w% emollient, and

[0354] - 0.1 w / w% to 3 w / w% of fragrance,

[0355] The w / w % fractions are related to the total weight of the emulsion and the sum of the w / w % fractions is less than or equal to 100%.

[0356] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a powder shampoo. The powder shampoo preferably comprises approximately:

[0357] - 32 w / w% surfactants, in particular 30 w / w% sodium cocoyl isethionate and 2 w / w% betaine, relative to the final product,

[0358] - 55 w / w% to 56 w / w% filler, in particular tapioca starch,

[0359] -5w / w% of the micropowder of the present invention as a texture enhancer,

[0360] - 5 w / w% of further texture enhancers, in particular isoamyl laurate,

[0361] - 2 w / w % of conditioning agents, in particular hydrolyzed wheat protein (hydrotriticum),

[0362] -0.5w / w% emollient, especially jojoba oil,

[0363] 0.4w / w% fragrance, especially lavender oil.

[0364] A powder shampoo of the present invention (also known as a dry shampoo) was compared to a powder shampoo that used a synthetic petroleum-based polymer micropowder instead of the present invention's micropowder. After using both powder shampoos, users reported that their skin felt better after using the powder shampoo of the present invention.

[0365] In a further preferred embodiment of the present invention, the cosmetic or personal care product is an anti-aging cream. The anti-aging cream preferably comprises approximately:

[0366] - 40 w / w % to 80 w / w % of a first solvent, in particular water,

[0367] -1 w / w% to 10 w / w% wetting agent,

[0368] - 0.1 w / w% to 5 w / w% rheology modifier,

[0369] -0.01w / w% to 2w / w% of complexing agent,

[0370] - 2 w / w% to 10 w / w% emulsifier,

[0371] -5w / w% to 30w / w% emollient,

[0372] - 0.5w / w% to 5w / w% skin soothing agents,

[0373] - 0.1 w / w % to 10 w / w % of a second solvent, in particular an organic solvent,

[0374] - 0.1 w / w% to 3 w / w% tocopherol,

[0375] - 0.5 w / w% to 10 w / w% of the micropowder of the present invention,

[0376] - 0.01 w / w% to 0.5 w / w% of a pH adjuster, and

[0377] - optional spices,

[0378] The w / w % fractions are related to the total weight of the emulsion and the sum of the w / w % fractions is less than or equal to 100%.

[0379] In a further preferred embodiment of the present invention, the cosmetic or personal care product is an anti-aging cream. The anti-aging cream preferably comprises approximately:

[0380] - 63 to 64 w / w % of a first solvent, in particular water,

[0381] - 3 w / w% of a wetting agent, in particular propylene glycol,

[0382] - 1.8 w / w% rheology modifier, especially xanthan gum,

[0383] -0.1w / w% complex agent, especially sodium phytate aqueous solution and alcohol,

[0384] - 6 w / w % of emulsifiers, in particular 4 w / w % of palmitic acid and 2 w / w % of cetearyl alcohol, relative to the final product;

[0385] - 20 w / w% emollients, in particular 3 w / w% shea butter, 2 w / w% squalane, 5 w / w% coco-caprylate and 5 w / w% ethylhexyl stearate, relative to the final product,

[0386] - 1.5 w / w% skin soothing agents, especially dimethicone,

[0387] - 1 w / w % of a second solvent, in particular hexylene glycol,

[0388] -1.2w / w% tocopherol,

[0389] -1w / w% of the micropowder of the present invention,

[0390] - 0.02 w / w% of a pH adjuster, preferably comprising an aqueous solution of sodium hydroxide at a concentration of up to 30 w / w%, and

[0391] - Optional spices.

[0392] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a facial sunscreen. The facial sunscreen preferably comprises approximately:

[0393] - 50 w / w% to 60 w / w% solvent, especially water,

[0394] - 24 w / w % to 34 w / w % of an emulsifier or a mixture of emulsifiers,

[0395] - 3 w / w% to 12 w / w% of a pigment or a mixture of pigments,

[0396] - 0.1w / w% to 1w / w moisturizer,

[0397] - 0.5 w / w% to 6 w / w% emollient,

[0398] - 0.1 w / w% to 5 w / w% rheology modifier,

[0399] - 0.05w / w% to 0.3w / w% antioxidants,

[0400] - 0.2w / w% to 1.5w / w% of preservatives,

[0401] -0.5 w / w% to 1 w / w% of the micropowder of the present invention and

[0402] - optional spices (qs - enough),

[0403] The w / w % fractions are related to the total weight of the cosmetic or personal care product and the sum of the w / w % fractions is less than or equal to 100%.

[0404] The pH of the facial sunscreen is preferably between about 5.87 and 6. The viscosity of the sunscreen is preferably about 17,340 cP, particularly when measured 24 hours after production at 20°C. The viscosity of the sunscreen of the present invention, produced according to the preferred formulation described above, is optimal for spreading and application on the skin. Furthermore, the sunscreen is comfortable to use and adheres well to the skin, allowing for long-term use. Due to the presence of the micropowder, the sunscreen also has a substantially matte finish, which is particularly desirable to avoid unwanted shine or noticeable moisture on the skin. Furthermore, the sunscreen is highly compatible with makeup or other skincare products applied over the skin.

[0405] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a facial sunscreen. The facial sunscreen preferably comprises approximately:

[0406] -56.25 w / w% solvent, especially water,

[0407] - 28w / w% emulsifier, preferably comprising: about 3w / w% of polyglyceryl-3-polyricinoleate, 1w / w% of a mixture of polyglyceryl-3-polyricinoleate, polyglyceryl-4-oleate and propylene glycol, 8w / w% of isopentyl cocoate, 5w / w% of ethylhexyl palmitate, 7w / w% of decyl cocoate, 4w / w% of diisostearyl polyglyceryl-3-dilinoleate,

[0408] - 8.15 w / w % of a pigment, preferably a mixture comprising titanium dioxide, aluminum hydroxide, sodium lauroyl glutamate, lysine and magnesium chloride, one or more iron oxides, sodium lauroyl glutamate, lysine and magnesium chloride,

[0409] - 0.5 w / w % moisturizing cream (w / w %), preferably white beeswax,

[0410] - 3.5 w / w % of an emollient, preferably comprising 0.5 w / w % of hydrogenated castor oil and 3 w / w % of glycerol,

[0411] - 0.25 w / w% of a rheology modifier, preferably xanthan gum,

[0412] - 0.1 w / w% of an antioxidant, preferably tocopherol,

[0413] - 0.75 w / w % of a preservative, preferably comprising phenoxyethanol and ethylhexylglycerin,

[0414] - 0.75 w / w% of the micropowder of the present invention, and

[0415] - optional spices (qs - enough),

[0416] The w / w % fractions are related to the total weight of the cosmetic or personal care product and the sum of the w / w % fractions is less than or equal to 100%.

[0417] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a sebum control cream. The sebum control cream preferably comprises approximately:

[0418] - 65 w / w% to 75 w / w% of a solvent, in particular water,

[0419] -2w / w% to 8w / w% wetting agent,

[0420] - 0.2 w / w% to 2 w / w% rheology modifier,

[0421] - 12 w / w % to 20 w / w % of an emulsifier or a mixture of emulsifiers,

[0422] - 1 w / w% to 7 w / w% emollient,

[0423] - 0.2 w / w % to 5 w / w % of active ingredient or mixture of active ingredients,

[0424] - 0.05w / w% to 0.2w / w% antioxidants,

[0425] - 0.2w / w% to 1.5w / w% of preservatives,

[0426] - 0.5 w / w% to 2 w / w% of the micropowder of the present invention,

[0427] - optionally a complexing agent, and

[0428] - 0.1-2 w / w% of optional fragrance,

[0429] The w / w % fractions are related to the total weight of the cosmetic or personal care product and the sum of the w / w % fractions is less than or equal to 100%.

[0430] The pH of the sebum control cream is preferably about 6. The viscosity of the sebum control cream is preferably about 15,733 cP, particularly when measured at 25°C 24 hours after production. The sebum control cream produced using the preferred formulation described above has the appearance of an ivory or light beige emulsion, making it particularly attractive to consumers as a neutral-colored product that can be used as a base for makeup or layered with other products. The presence of the micropowder synergizes with the presence of one or more active ingredients to both reduce the appearance of oiliness on the skin by providing a matte finish and to reduce sebum production over the long term. Consequently, consumers using the sebum control cream of the present invention can observe both short-term and long-term benefits, leading to increased product satisfaction.

[0431] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a sebum control cream. The sebum control cream preferably comprises approximately:

[0432] - 69.2% w / w% of solvents, especially water,

[0433] - 5w / w% of a wetting agent, preferably propylene glycol,

[0434] - 1 w / w % of a rheology modifier, preferably comprising a mixture of xanthan gum and acacia gum,

[0435] - 16 w / w % of an emulsifier, preferably comprising a mixture of ethylhexyl stearate, isoamyl laurate, cetearyl alcohol, glyceryl behenate, behenyl alcohol and lecithin,

[0436] - 4 w / w % of an emollient, preferably comprising a mixture of squalene, sodium acrylates copolymer and lecithin,

[0437] - 2 w / w% of active ingredient, preferably a mixture comprising propylene glycol, water and fomes officinalis extract,

[0438] - 0.1 w / w% of an antioxidant, preferably tocopherol,

[0439] - 1 w / w % of a preservative, preferably comprising a mixture of phenoxyethanol and ethylhexylglycerin,

[0440] -1.5w / w% of the micropowder of the present invention, and

[0441] -0.2w / w% of spices,

[0442] The w / w % fractions are related to the total weight of the cosmetic or personal care product and the sum of the w / w % fractions is less than or equal to 100%.

[0443] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a restorative night cream. The restorative night cream preferably comprises approximately:

[0444] - 50 w / w% to 60 w / w% of a solvent, in particular water,

[0445] -1 w / w% to 5 w / w% wetting agent,

[0446] - 0.01 w / w% to 0.2 w / w% of complexing agent,

[0447] - 0.5 w / w% to 2.0 w / w% rheology modifier,

[0448] - 20 w / w% to 30 w / w% of an emulsifier or a mixture of emulsifiers,

[0449] -8w / w% to 14w / w% emollients,

[0450] - 0.5 w / w% to 2 w / w% of active ingredients, especially antioxidant wetting agents,

[0451] - 0.05w / w% to 0.2w / w% antioxidants,

[0452] - 0.5 w / w% to 2 w / w% of preservatives,

[0453] - 0.5 w / w% to 3 w / w% of the micropowder of the present invention, and

[0454] - optionally 0.05 w / w% to 0.5 w / w% of fragrance,

[0455] The w / w % fractions are related to the total weight of the cosmetic or personal care product and the sum of the w / w % fractions is less than or equal to 100%.

[0456] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a restorative night cream. The restorative night cream preferably comprises about

[0457] -56.7 w / w% solvent, especially water,

[0458] - 3 w / w % of a wetting agent, preferably propylene glycol,

[0459] - 0.1 w / w% of a complexing agent, in particular comprising sodium phytate, alcohol and water,

[0460] - 1.5 w / w % of a rheology modifier, preferably comprising a mixture of xanthan gum, lecithin, sclerotium gum and pullulan,

[0461] - 24 w / w % of an emulsifier, preferably a mixture comprising 8 w / w % of isoamyl cocoate,

[0462] - 10 w / w% of caprylic or capric triglyceride, 4 w / w% of oleyl erucate and 2 w / w% of pentaerythritol distearate,

[0463] - 11 w / w% of an emollient, preferably comprising 1 w / w% of dimethicone, 6 w / w% of shea butter (butyrospermum parkii (shea) butter), and 4 w / w% of a mixture of glyceryl behenate, behenyl alcohol and lecithin,

[0464] - 1 w / w% active ingredient, preferably cranberry fruit extract,

[0465] - 0.1 w / w% of an antioxidant, preferably tocopherol,

[0466] - 1 w / w % of a preservative, preferably comprising a mixture of phenoxyethanol and ethylhexylglycerin,

[0467] -1.5w / w% of the micropowder of the present invention, and

[0468] -0.1w / w% of spices,

[0469] The w / w % fractions are related to the total weight of the cosmetic or personal care product and the sum of the w / w % fractions is less than or equal to 100%.

[0470] The pH of the restorative night cream is preferably about 6. Preferably, the restorative night cream has a viscosity of about 10,516 cP, particularly when measured at 25°C 24 hours after production. The restorative night cream produced using the preferred formulation has an ivory or light beige emulsion appearance, which is particularly attractive to consumers. The cream adheres well to the skin, providing a comfortable, soft feel.

[0471] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a color correcting primer. The color correcting primer preferably comprises approximately:

[0472] - 65 w / w% to 75 w / w% of a solvent, in particular water,

[0473] - 0.5 w / w% to 5 w / w% thickener,

[0474] - 0.1 w / w% to 5 w / w% of a pigment or combination of pigments,

[0475] - 7 w / w % to 20 w / w % of a wetting agent or a combination of wetting agents,

[0476] - 3 w / w% to 8 w / w% of an emulsifier or a mixture of emulsifiers,

[0477] - 0.5w / w% to 1.5w / w% of preservatives,

[0478] -1 w / w% to 3 w / w% of the micropowder of the present invention, and

[0479] - optional stabilizer (qs),

[0480] wherein the w / w % fractions relate to the total weight of the cosmetic or personal care product and the sum of the w / w % fractions is less than or equal to 100%.

[0481] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a color correcting primer. The color correcting primer preferably comprises approximately:

[0482] -70.9w / w% solvent, especially water,

[0483] -1 w / w% thickener, preferably sodium polyacrylate,

[0484] - 2.6 w / w % of a pigment or combination of pigments, preferably a mixture of titanium dioxide, mica, tin oxide and synthetic fluorphlogopite,

[0485] - 15 w / w % of a wetting agent, preferably propylene glycol and pentylene glycol,

[0486] - 7 w / w% emulsifier, preferably 2 w / w% sucrose laurate and 5 w / w% coco-caprylate,

[0487] - 1 w / w% of a preservative, preferably a mixture of phenoxyethanol and ethylhexylglycerin,

[0488] -1.5w / w% of the micropowder of the present invention, and

[0489] - optional stabilizer (qs), preferably citric acid solution,

[0490] wherein the w / w % fractions relate to the total weight of the cosmetic or personal care product and the sum of the w / w % fractions is less than or equal to 100%.

[0491] The pH value of the color correcting base cream is preferably about 6. Preferably, the viscosity of the color correcting base cream is about 16,760 cP, particularly when measured 24 hours after production of the color correcting base cream at 25° C. The base cream produced using the above preferred formulation has a pink pearlescent cream appearance, allowing for stable application to the skin.

[0492] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a BB (concealer) cream. The BB cream preferably comprises approximately:

[0493] - 65 w / w% to 75 w / w% of a solvent, in particular water,

[0494] -2w / w% to 7w / w% wetting agent,

[0495] - 0.05 w / w% to 2 w / w% of complexing agent,

[0496] - 0.5 w / w% to 2 w / w% rheology modifier,

[0497] - 10 w / w% to 20 w / w% of an emulsifier or a combination of emulsifiers,

[0498] - 2 w / w% to 5 w / w% of a complexing agent or a combination of complexing agents,

[0499] - 3 w / w% to 8 w / w% of a pigment or combination of pigments,

[0500] - 0.05w / w% to 0.2w / w% antioxidants,

[0501] - 0.5 w / w% to 2 w / w% of preservatives,

[0502] - 0.01 w / w% to 0.1 w / w% of stabilizer,

[0503] - 0.25 w / w% to 1.5 w / w% of the micropowder of the present invention, and

[0504] - optional spices (qs),

[0505] wherein the w / w % fractions relate to the total weight of the cosmetic or personal care product and the sum of the w / w % fractions is less than or equal to 100%.

[0506] In a further preferred embodiment of the present invention, the cosmetic or personal care product is a BB (concealer) cream. The BB cream preferably comprises approximately:

[0507] 69.29w / w% solvent, especially water,

[0508] 4w / w% of a wetting agent, preferably propylene glycol,

[0509] 0.1 w / w% of a complexing agent, preferably tetrasodium glutamate diacetate,

[0510] 1w / w% rheology modifier, preferably lysolecithin, microsclerotium gum, xanthan gum and pullulan,

[0511] 15w / w% emulsifier, preferably comprising 3w / w% coco-caprylate, 5w / w% diethylhexyl sebacate and 7w / w% caprylic or capric triglyceride,

[0512] - 3.5 w / w% of a complexing agent, preferably comprising arachidyl alcohol, behenyl alcohol and arachidyl glucoside,

[0513] - 5.23 w / w % of a pigment or combination of pigments, preferably comprising titanium dioxide, aluminum hydroxide, sodium lauroyl glutamate, lysine, magnesium chloride and iron oxides,

[0514] - 0.1 w / w% of an antioxidant, preferably tocopherol,

[0515] - 1 w / w% of a preservative, preferably a combination of phenoxyethanol and ethylhexylglycerin,

[0516] - 0.03 w / w% of a stabilizer, preferably comprising aqueous citric acid solution (50% solution),

[0517] -0.75 w / w% of the weight percentage of the micropowder of the present invention, and

[0518] - optional spices (qs),

[0519] The w / w % fractions are related to the total weight of the cosmetic or personal care product and the sum of the w / w % fractions is less than or equal to 100%.

[0520] The pH of BB cream is preferably about 5.7. Preferably, the viscosity of BB cream is about 2324 cP, particularly when measured at 25°C 24 hours after production. BB cream has the appearance of a colored fluid emulsion and is particularly suitable for use as a BB cream. In particular, BB cream can be made particularly translucent, soft, and oil-absorbing, making it ideal for meeting user needs.

[0521] The products and formulations of the present invention have been extensively tested. It was found that the wide particle size distribution, irregular shape, and high oil and water absorption of the bacterial cellulose particles contribute to improved product sensory properties and user satisfaction. In particular, these products were found to exhibit excellent matte properties.

[0522] Due to its high matte effect, the micropowder can partially or completely replace talc in formulations, making these formulations safer and more user-friendly. The products of the present invention have also been found to provide increased softness, reduced stickiness, and reduced greasiness compared to similar products containing conventional micropowders instead of the micropowder of the present invention. The micropowder can be used as a mild exfoliant, agglomerated by friction. It has also been found to be suitable for use in both hot and cold products, ranging from cosmetics to cleansers used in hot water. By using the micropowder of the present invention, the biocompatibility and sustainability of all products are improved.

[0523] Terms such as substantially, approximately, about, approximately, almost etc. preferably describe a tolerance range of less than ±20%, preferably less than ±10%, particularly preferably less than ±5% and in particular less than ±1% and include the exact value.

[0524] Those skilled in the art will recognize that the technical features, definitions and advantages of the preferred embodiments of the micropowder according to the present invention also apply to the method for its production, the product containing it and vice versa.

[0525] Detailed description and examples of the invention

[0526] It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention.It is intended that the claims of the present invention define the scope of the invention and that methods and apparatus within the scope of these claims and their equivalents be covered thereby.

[0527] Without intending to limit the invention, the invention will be explained in more detail with reference to exemplary embodiments and the following drawings.

[0528] BRIEF DESCRIPTION OF THE DRAWINGS

[0529] Figures 1 to 4 Shown are magnified views of a first micropowder sample according to a preferred embodiment of the present invention, taken at steadily increasing magnifications using a SEM microscope.

[0530] Figure 1 A magnified view of the first sample of micropowder is shown, 2 cm (scale bar) = 100 μm.

[0531] Figure 2 A magnified view of the first sample of micropowder is shown, 2 cm (scale bar) = 30 μm (100x magnification).

[0532] Figure 3 A magnified view of the first sample of micropowder is shown, 2 cm (scale bar) = 10 μm (1000x magnification).

[0533] Figure 4 A magnified view of the first sample of micropowder is shown, 2 cm (scale bar) = 1 μm (10,000x magnification).

[0534] Figures 5 and 6 An enlarged view of a second sample of micropowder according to a further preferred embodiment of the present invention taken using a SEM microscope is shown.

[0535] Figure 5 A magnified view of a second sample of micropowder is shown, 1 cm (scale bar) = 30 μm (100x magnification).

[0536] Figure 6 A magnified view of a second sample of micropowder is shown, 1 cm (scale bar) = 1 μm (10,000x magnification).

[0537] Figure 7 Schematic diagram of the pore types present in micronized sample particles.

[0538] Figure 8 A photographic image of a micropowder according to a preferred embodiment of the present invention is shown.

[0539] Figure 9 The degradation of the micropowder according to the preferred embodiment of the present invention is shown, indicating that the biodegradation rate exceeds 75% within 28 days.

[0540] Figure 10 The oil absorption capacity of a micropowder according to a preferred embodiment of the present invention and a series of prior art micropowders for a range of different oils is shown.

[0541] Figure 11 The oil absorption capacity of various micropowders according to various preferred embodiments of the present invention is shown, wherein the micropowders have different average particle sizes.

[0542] Figure 12 The results of X-ray diffraction analysis of the fine powder of the preferred embodiment are shown.

[0543] Figure 13 The particle size distribution of the micropowder of the preferred embodiment is shown.

[0544] Figure 14 The results of volumetric gas adsorption analysis of the micropowder of the preferred embodiment are shown.

[0545] Figure 15 Shown is a scanning electron microscope image of plant cellulose powder at 10,000x magnification, where 1 cm (scale bar) = 1 μm.

[0546] Figure 16 A scanning electron microscope image of bacterial cellulose powder according to a first preferred embodiment of the present invention is shown, with a magnification of 10,000 times, wherein 1 cm (scale bar) = 1 μm.

[0547] Figure 17 A scanning electron microscope image of bacterial cellulose powder according to a further preferred embodiment of the present invention is shown, with a magnification of 10,000 times, wherein 1 cm (scale bar) = 1 μm.

[0548] Figure 18 The oil absorption capacity for oleic acid of the micropowder according to the preferred embodiment of the present invention and a series of prior art micropowders is shown. DETAILED DESCRIPTION

[0549] The accompanying drawings show the results of various tests conducted on micropowder samples according to a preferred embodiment of the present invention. The micropowder is formed from a large amount of bacterial cellulose film harvested from a culture. After washing, the film is dried at a relative humidity of 80% and at 30°C for one week. The dried film is treated with nitrogen, crushed and ground. The grinding is carried out in steps, including cutting, coarse grinding and fine grinding. The finely ground bacterial cellulose is then mixed with deionized water and stirred to form a suspension with a concentration of about 2w / w% bacterial cellulose. The suspension is then pumped into an atomizer and spray dried. High-purity nitrogen is used to atomize the suspension. Spray drying is carried out in a B-290 Buchi spray dryer, and the dried micropowder is then pumped into a cyclone separator and then collected. Spray drying is carried out at a temperature of about 200°C to ensure the cornification of the bacterial cellulose.

[0550] The powder was then analyzed by scanning electron microscopy. A Gemini SEM 300 (Zeiss) device was used with an accelerating voltage of 0.02kV to 30kV and a resolution of 0.8nm at 15kV. A magnification of up to 2,000,000 times was used to provide high-resolution images of the powder. SEM images were acquired using an InLens detector at an accelerating voltage of 2kV and a probe current of 80pA. A small amount of powder was applied to an aluminum rod with a carbon tape using a scraper. In order to reduce the charging effect, a thin copper foil was applied to the edge of each aluminum rod. Excess powder was blown off with air. The sample was coated with gold using a Polaron SC7640 sputtering machine. A coating sequence of 40 seconds was used at 20mA. Image analysis was performed using image processing software (Olympus GmbH, Germany) to help determine the particle size and its distribution.

[0551] Figure 1-4 The results of the first sample at different magnifications are shown. Figure 1 As shown, bacterial cellulose particles have irregular shapes, including polyhedral and plate-like particles. The particle surface is uneven, which increases the surface area and light diffusion properties.

[0552] exist Figure 2 Various cracks and defects can be seen on the surface of the polyhedral particles. Adsorption testing was used to confirm that these were evidence of the presence of mesopores and mesopores within the bacterial cellulose particles. As described below, the adsorption analysis showed the characteristics of type III and type V isotherms.

[0553] Figure 3 A further zoomed-in image of the first sample of the micropowder is shown, where the irregularities in the particle shape, its layered structure, and surface roughness are even more visible. It is clear from this image that the micropowdered bacterial cellulose particles have a much larger surface area to mass ratio than traditional microbeads, which have relatively regular spherical particles.

[0554] Figure 4 A further magnified image of the first sample of the micropowder is shown, where a matte, fibrous surface quality can be observed. This surface quality further increases the surface area of ​​the particles, which in turn improves their absorption and adsorption qualities.

[0555] Figure 5 A magnified image of a second sample showing micronized powder. Plate-like, layered particles can be observed. They are densely packed to provide high coverage and scatter light to create a matte effect.

[0556] The surface quality of these particles is shown in Figure 6In a further magnified image (the maximum magnification of the SEM microscope images used again in this article). In this image, it can be observed that even the seemingly smooth parts of the bacterial cellulose particles show microvilli. These are visible as lines running through the surface of the particles and are formed by cellulose fibers. Due to the presence of microvilli at the surface of the bacterial cellulose particles, their surface area to volume ratio is significantly increased, thereby improving their absorption properties. In addition, the overlapping and layered arrangement of the cellulose fibers results in a large proportion of through- and blind pores in the bacterial cellulose particles, which have openings at the particle surface. The absorption and adsorption capacity of the micropowder is thereby further improved, contributing to the surprisingly high performance of the micropowder of the present invention compared to the prior art.

[0557] exist Figure 16 and Figure 17 Microvilli can also be observed on the surface of the bacterial cellulose particles shown in the scanning electron microscope image. This demonstrates the bacterial cellulose particles formed in a sample of a further preferred embodiment of the micropowder of the present invention. While the analyzed particles contain pores and a dense solid fiber structure in their core, the surface of the particles has a looser fiber structure, significantly increasing their surface area.

[0558] Visual comparison of the surface quality of particles formed according to the present invention with that of particles produced by other methods can confirm the presence or absence of microvilli on the particle surface. Figure 15 The surface of a powder particle formed from plant cellulose is shown at a magnification of Figure 17 same. Figure 15 A scanning electron microscope image of a plant cellulose particle is provided for comparison only. As can be seen here, the surface is essentially flat, with no loose protruding fibers. Therefore, the absence of microvilli in the particle surface structure can be confirmed by microscopic analysis.

[0559] Figure 7 A schematic diagram shows the various types of pores found in bacterial cellulose particles. Through pores (1) are channels between two openings in the surface of a bacterial cellulose particle. Blind pores (3) are channels with only one opening in the surface of the bacterial cellulose, while closed pores (2) are voids completely enclosed within the bacterial cellulose. Tests have shown that micronized bacterial cellulose particles have a high proportion of through pores, which is believed to increase the micronized powder's oil absorption capacity.

[0560] Figure 8Photographic images of the micropowder are shown. As can be seen, the micropowder is neutral white and has strong light-scattering properties. It is worth noting that the color range of other samples depends on the production method, including white, off-white, pearly white, creamy white, brown, yellow, light or dark yellow, dark brown, or wood color, without the use of pigments or bleaching agents. The neutral color and optical properties of the micropowder provide high versatility for use as an opacifier or pigment in consumer products.

[0561] Figure 9 The results of biodegradability tests performed on samples of micropowder according to a preferred embodiment are shown (as shown in the SEM and photographic images above). During the biodegradation of the samples, microorganisms in the test bottles convert oxygen into carbon dioxide (CO2). It is a cap-shaped manometer attached to the test bottle. It can measure the biochemical oxygen demand without generating any oxygen. It can simply detect the degree of pressure drop in the bottle. After the lid is sealed, the sample is incubated in a thermostatic chamber (IN804, Yamato Scientific, Japan). According to the OECD (Guideline for Testing Chemicals: Ready biodegradability (1992)) and CSCL (Guideline of Chemical Substances Control Law: Biodegradability Test of Chemical Substances by Microorganisms (2018) (Japanese) guidelines, when the biochemical oxygen demand (BOD) value reaches 60% of the theoretical oxygen demand (ThOD) of the sample during the test, the sample is considered to have been completely degraded (the remaining 40% is considered to have been absorbed by microorganisms). In this sample, 75% biodegradability was achieved within 28 days.

[0562] Figure 10 The chart shows the oil absorption test results for a micropowder sample of the preferred embodiment and various different micropowder samples from the prior art. The oil absorption capacity was tested according to the ASTM D281-95 method known to those skilled in the art. The results show that the sample micropowder can absorb approximately 5 g / g of jojoba oil, while the absorption rates for sunflower oil, orange essential oil, and grapefruit essential oil all exceed 5 g / g. These results are more than twice the performance of the most commonly used micropowders from the prior art. As can be seen from the chart, the closest performance is provided by microcrystalline cellulose particles derived from plant cellulose. Due to different material properties, under the same conditions, its oil absorption capacity for sunflower oil is approximately 2 g / g. This is less than 40% of the absorption capacity of the micropowder produced according to the present invention.

[0563] The oil absorption performance of the micropowder of the present invention even surpasses that of metal and plastic micropowders. Combined with the biodegradability demonstrated above, it is clear that the micropowder of the present invention can replace the micropowders of the prior art that have environmental problems without sacrificing consumer satisfaction.

[0564] Further analysis results of the samples used are shown in Table 1 below.

[0565] Table 1: Analysis results of micropowder according to a preferred embodiment of the present invention

[0566]

[0567]

[0568] a Monochromatic breath test ( WTW control and measurement system), b Double-loop diffraction

[0569] Instrument (D5000, Bruker-AXS), c ULM standard PIDS, d KERN DAB 200-3

[0570] (Hygrometer), e Modified ASTM D2819-5 method, f Dynamic vapor adsorption, 20℃,

[0571] 76% humidity, g BET nitrogen adsorption isotherm, h GPC, 8% LiCl in DMAc,

[0572] FM A (0.5% LiCl in DMAc).

[0573] Figure 11 The comparison of the oil absorption capacity of various micropowders produced according to the present invention, wherein the micropowders have different average diameters D 50 The oil absorption capacity of the samples was tested under the same conditions according to ASTM D281-95. It can be seen that for all the samples tested, despite their different particle sizes, the oil absorption capacity is very high, exceeding that of the prior art micropowder shown in the above figure.

[0574] also, Figure 11 It was shown that lower particle size favored higher oil absorption for all oils. A strong correlation between absorption capacity and average particle size was observed for vegetable oils in particular. Therefore, particle size can be used to adjust this property of micropowders, for example by adjusting milling speed and / or duration.

[0575] Figure 18A comparison of the oil absorption capacity of various micropowders produced according to the present invention and prior art micropowders for oleic acid is shown. Oleic acid is commonly used as an ingredient in the cosmetics and cosmeceuticals industries and, in this context, serves as a standard reference oil for measuring oil absorption capacity. According to the present invention, micropowders with varying particle sizes were produced from bacterial cellulose. The first sample, "Micropowder-67_Or," had an average particle size of 67 μm; the second sample, "Micropowder-204_FW," had an average particle size of 204 μm; the third sample, "Micropowder-106_FW," had an average particle size of 106 μm; the fourth sample, "Micropowder-8_HK," had an average particle size of 8 μm; and the fifth sample, "Micropowder-400_FW," had an average particle size of 400 μm. Other micropowders tested included polyvinyl dimethylsiloxane microplastics, microcrystalline cellulose, kaolin, PMMA cosmetic beads (specifically "Covabeads"), talc, and potato starch. The oil absorption capacity of the samples was tested under the same conditions according to ASTM D281-95. The prior art micropowders tested had an absorption capacity of up to 2.27 g / g of oleic acid. On the other hand, all prior art micropowders achieved an absorption capacity of at least 2.65 g / g, with the most absorbent sample achieving an absorption capacity of 5.64, more than double the absorption capacity of the best prior art micropowder studied.

[0576] Figure 12 The results of X-ray diffraction analysis of a micropowder sample of a preferred embodiment are shown (its properties are also listed in Table 1 above). X-ray diffraction analysis was performed using a double-loop diffractometer (D5000, Bruker-AXS), monochromator: Ge (111) main beam monochromator, wavelength: Cu-Kα1; λ = 0.15406 nm, detector: scintillation counter, operation (standard): symmetric transmission. While rotating the sample, the diffraction angles of 5-80 degrees (2θ) were analyzed with a step size of 0.02 degrees and 0.2 seconds per step. Prior to analysis, the sample was ground with ethanol, dispersed on a zero-background silicon sample holder, and placed under a lamp to evaporate the ethanol. The results were used to study the crystallinity of the micropowder.

[0577] Figure 13The particle size distribution analysis results of the micropowder samples of the preferred embodiment are shown. The particle size distribution was measured dryly using laser diffraction using a Mastersizer 3000 (Malvern Panalytical, Ltd, Malvern, Great Britain) with an Aero S accessory. The light scattering data converted to a particle size distribution was analyzed using a Mie scattering model using a non-spherical particle type and MgCCb as the material (i.e., MgCCb was set to a refractive index of (1.717) and an adsorption index of (0.01)). The sample container was thoroughly mixed before adding the sample to the instrument to ensure good sampling. A few grams of powder were used for each measurement and the measurement time was set to 10-30 seconds. The lower limit of the obstruction was set to 0.5%, the upper limit was set to 5%, and the air pressure was set to 1.5 bar. The feed rate was continuously adjusted during the measurement to keep the obstruction between 0.5% and 5%. All measurements were averaged and run at least five times. As shown in Table 1, the average particle size D of the sample was found to be 0.5%. 50 This provides excellent oil absorption, water absorption, mattifying effect and pore coverage while being safe and biocompatible.

[0578] Figure 14 The results of a volumetric gas adsorption analysis performed on a micropowder sample are shown. This was used to perform a Brunauer-Emmett-Teller (BET) analysis of the surface area to mass ratio of the micropowder and draw conclusions about its porosity. The test involved nitrogen adsorption in a liquid nitrogen bath at 77 K. The measurements were performed on a BelsorpMax II surface area and porosity analyzer. Prior to analysis, the sample was degassed in a FlowPrep 060 sample degassing system under nitrogen flow at 105°C for 12 hours. The surface area was determined using the well-established BET equation and thus calculated from the nitrogen adsorption isotherm (Brunauer et al., JACS, 60, 1938, 309-319).

[0579] The data show that the analyzed micropowders follow a Type V isotherm and are mesoporous. A Type V isotherm is typically observed for flat, homogeneous adsorbents. The initial path of this isotherm is similar to that of a Type III isotherm. In this case, because the heat of adsorption is lower than the heat of liquefaction, the adsorbate preferentially interacts with the monolayer rather than the adsorbent surface. Furthermore, the high affinity isotherm is typical of very strong adsorption interactions.

[0580] The average surface area to mass ratio S of the sample was calculated based on the adsorption data. BET 7.8m 2 / g. The ratio of the average surface area to mass of the mesoporous particles S is calculated Meso 42.1m 2 / g, average pore radius r pore It is 5.6nm.

[0581] Table 2 shows the results of user testing of various formulations applied to the skin.

[0582] Table 2 - Sensory evaluation results of micropowder

[0583]

[0584] The micropowder was tested in the form of an emulsion with the formula shown in Table 3 below. 70 μL of the emulsion was applied to the back of the user's hand and spread eight times using three fingers of the other hand. The user was asked to rate the softness and greasiness felt during application. The scale used was from 0 to 10, with 0 representing no softness and no greasiness, and 10 representing very softness and very greasiness.

[0585] The after-use experience of the micropowder was tested using a lotion with the formula described above. 70 μL of the lotion was applied to the back of the user's hand and spread 20 times using three fingers of the other hand. After one minute, the user was asked to rate their after-use experience. The stickiness rating used to evaluate the after-use experience was scaled from 0 to 10, with 0 representing no stickiness and 10 representing very strong stickiness. The stickiness was tested by gently patting the back of the applied lotion with the other hand.

[0586] Users tested the softness they experienced by stroking the back of their hands on a scale from 0 (not soft at all) to 10 (very soft).

[0587] The user runs their index finger and thumb over the back of the lotioned hand to test the greasiness experienced after use. The scale used is from 0 to 10, where 0 represents no greasiness and 10 represents very high greasiness.

[0588] Compared to formulations containing polymethyl methacrylate or silica micropowder, users reported a softer feel during and after application of formulations containing the bacterial cellulose micropowder of the present invention. Users also reported less stickiness and greasiness. Visually, a semi-matte effect was observed when using the micropowder of the preferred embodiment. This is believed to be due to the high surface area to volume ratio, high porosity, and irregular shape of the bacterial cellulose particles, which provide high oil absorption. The particle size distribution was also found to provide good coverage when used in foundations and to provide volume and length to eyelashes when used in mascara. Therefore, this micropowder shows great potential to replace prior art micropowders.

[0589] In addition, the inventors also studied the performance of the bacterial cellulose powder of the present invention compared with the powder based on plant cellulose. The powder samples were prepared from the bacterial cellulose cultured according to the preferred embodiment of the present invention, which were also Figure 17The results are shown in the enlarged image. In addition, a sample of plant cellulose micropowder was provided for comparison. The samples were visually compared and quantitatively analyzed. Table 3 below shows the comparison results:

[0590] Table 3 - Analysis results of plant cellulose powder and bacterial cellulose powder according to a preferred embodiment of the present invention:

[0591]

[0592] from Figure 17 It can be seen that the bacterial cellulose powder produced by the teaching of the present invention has a surface covered with obvious microvilli.

[0593] The collected data also showed that the micropowder samples produced according to the present invention had a much higher void volume and a much higher porosity, particularly mesoporosity, than plant cellulose. Specifically, BJH (Barrett-Joyner-Halenda) porosity analysis showed that the bacterial cellulose micropowder according to the preferred embodiment of the present invention had a mesoporosity approximately 2.4 times higher than that of the plant cellulose powder used for comparison.

[0594] Surprisingly, the oil absorption capacity of the bacterial cellulose powder produced according to the present invention significantly exceeds that of plant cellulose, wherein the absorption capacity is at least doubled.

[0595] The application of micropowders in cosmetics or personal care products has been shown to be particularly advantageous. The following cosmetic formulations are listed in Tables 4-13, but are not limited thereto. Tables 4-13 illustrate the possible applications and extraordinary potential of the micropowders of the present invention in improving the performance of the corresponding products.

[0596] Table 4 - Exemplary formulations of body or facial lotions containing the micronized powders of the present invention as sensory enhancers, compared to equivalent formulations using other powders:

[0597]

[0598] Table 5 - Exemplary formulations of mascaras containing the micronized powders of the present invention:

[0599]

[0600]

[0601] Table 6 - Exemplary formulations and comparisons of four loose powders containing the micropowders of the present invention:

[0602]

[0603] Table 7 - Exemplary formulations of liquid foundations containing the micronized powders of the present invention and comparisons with liquid foundations containing different powders:

[0604]

[0605]

[0606] Table 8 - Exemplary formulations and comparisons of butter cream formulations with and without the micropowders of the present invention Examples 12 to 18:

[0607]

[0608] 1: Glucose methyl sesquistearate, 2: Lavender and orange, 3: Dehydroacetic acid, benzyl alcohol

[0609] Table 9 - Exemplary formulations of lipsticks containing the micronized powders of the present invention:

[0610] Element Material function Preparation (% w / w) synthetic wax Structuring agent 11.5 Euphorbia wax Structuring agent 2 Tricyclodecane methyl isononanoate Structuring agent 14 Emollients Emollients 32.1 seed oil Emollients 30.5 Micro powder (bacterial cellulose) Texturizing Agents / Skin Sensory Enhancers 4 Hydrogenated polydecene, polyhydroxystearic acid Lake dispersants 2 Mica, iron oxide Pearlescent agent 0.7 pigment pigment 6.36 Tocopherol antioxidants 0.1 Caprylyl glycol, phenoxyethanol preservative 0.75

[0611] Table 10 - Exemplary formulations and comparisons of hand creams with and without the micropowders of the present invention:

[0612]

[0613] Table 11 - Exemplary formulations of lip balms containing the micropowders of the present invention:

[0614]

[0615]

[0616] Table 12 - Exemplary formulations of powder shampoos containing the micronized powders of the present invention and comparisons with powder shampoos containing synthetic powders:

[0617]

[0618] Table 13 - Exemplary Formulation Example 28 of an Anti-Aging Cream Containing the Micropowders of the Invention:

[0619]

[0620]

[0621] Table 14 - Exemplary Formulation Example 29 of a Facial Sunscreen Containing the Micropowders of the Invention:

[0622]

[0623] Table 15 - Exemplary Formulation Example 30 of a Sebum Control Cream Containing the Micropowder of the Invention:

[0624]

[0625] Table 16 - Exemplary Formulation Example 31 of a Restorative Night Cream Containing the Micropowders of the Invention:

[0626]

[0627]

[0628] Table 17 - Exemplary Formulation Example 32 of a Color Correcting Primer Containing the Micropowders of the Invention:

[0629]

[0630] Table 18 - Example 33 of the exemplary formulation of a BB cream containing the micropowder of the present invention:

[0631]

[0632]

Claims

1. A micropowder comprising bacterial cellulose particles, characterized in that The micropowder has an oil absorption capacity of at least 2.5 g / g and is biodegradable.

2. The micropowder according to claim 1, characterized in that The micropowder biodegrades to 75% within 35 days, preferably to 75% within 28 days.

3. The micropowder according to any one of the preceding claims, characterized in that The oil absorption capacity of the micropowder is at least 4 g / g, preferably at least 4.5 g / g, even more preferably at least 5 g / g.

4. The micropowder according to any one of the preceding claims, characterized in that The average particle size D of the bacterial cellulose particles 50 The bacterial cellulose particles have a diameter between 1 μm and 1000 μm, and an average crystallinity between 30% and 80%.

5. The micropowder according to any one of the preceding claims, characterized in that The fine powder is produced by a method comprising grinding bacterial cellulose from a culture and drying the ground bacterial cellulose, wherein the drying is preferably configured to keratinize the bacterial cellulose.

6. The micropowder according to any one of the preceding claims, characterized in that The average particle size D of the bacterial cellulose particles 50 Between 1 μm and 500 μm, preferably between 5 μm and 250 μm, particularly preferably between 25 μm and 100 μm, wherein the average aspect ratio of the bacterial cellulose particles is preferably between 10:1 and 1:10, preferably between 5:1 and 1:5, more preferably between 2:1 and 1:

2.

7. The micropowder according to any one of the preceding claims, characterized in that The average crystallinity of the bacterial cellulose particles is between 40% and 80%, preferably between 40% and 60%, and particularly preferably between 40% and 50%.

8. The micropowder according to any one of the preceding claims, characterized in that The bacterial cellulose particles are mesoporous with an average pore radius of 1 nm to 50 nm, preferably 5 nm to 20 nm, even more preferably 7 nm, wherein the surface area to mass ratio of the bacterial cellulose particles is preferably 10 nm to 20 nm. 2 / g to 100m 2 / g, more preferably 10m 2 / g to 80m 2 / g.

9. Method for producing a micropowder according to any one of the preceding claims, characterized in that The method comprises the following steps: - producing bacterial cellulose from a bacterial culture such that the average crystallinity of the produced bacterial cellulose is between 30% and 80%, - grinding the bacterial cellulose to form bacterial cellulose particles having an average particle size of 1 μm to 1000 μm, - Drying of ground bacterial cellulose granules.

10. The method according to the preceding claim, characterized in that The bacterial cellulose is at least partially dried between its production and grinding, wherein the partial drying is preferably carried out in an atmosphere with a relative humidity of up to 85%, preferably up to 80%, and a temperature between 20°C and 40°C, preferably between 25°C and 35°C, for a period of 3 to 10 days, preferably 5 to 9 days.

11. The method according to any one of claims 9 or 10, characterized in that Prior to grinding, the bacterial cellulose is treated with a liquefied gas, preferably liquid nitrogen.

12. The method according to any one of claims 9 to 11, characterized in that Prior to drying, the ground bacterial cellulose particles are mixed with deionized water to form a suspension having a bacterial cellulose concentration in water of 0.5 to 5 w / w%, more preferably 1.0 to 3.5 w / w%.

13. The method according to the preceding claim, characterized in that , The suspension of bacterial cellulose in water is spray-dried, wherein the spray-drying preferably comprises the following steps: - atomizing said suspension of bacterial cellulose in water to form droplets suspended in a gas, wherein said atomization is preferably assisted by using a pressurized gas, in particular air or an inert gas, particularly preferably nitrogen, - subjecting the suspended droplets to a stream of heated air, such that the water content of the droplets is reduced, the temperature of the heated air preferably being between 80° C. and 250° C., particularly preferably between 150° C. and 190° C., - Collect the dried granules.

14. The method according to any one of claims 9 to 13, characterized in that freeze-drying the suspension of bacterial cellulose in water, wherein the freeze-drying preferably comprises the following steps: - freezing the suspension at a temperature between -10°C and -50°C, preferably between -15°C and -25°C, - reducing the pressure of the controlled atmosphere surrounding the frozen suspension to less than 50 mbar, preferably less than 1 mbar, more preferably less than 0.5 mbar, so that ice from the frozen suspension sublimes and the resulting agglomerate has a moisture content of less than 7 w / w%, preferably less than 5 w / w%, particularly preferably less than 1 w / w%.

15. A cosmetic or personal care product comprising the micropowder according to any one of claims 1 to 8, wherein the cosmetic or personal care product is preferably an anti-aging product, a treatment product for oily and acne-prone skin, a face mask, a moisturizer, a butter cream, a lotion, a foundation, a concealer product, a loose or pressed powder, a mascara, a lipstick, a lip gloss, a liquid shampoo, a dry shampoo, a shampoo bar, a hair mask, a conditioner, a hair styling product, an antiperspirant, a deodorant or an oral care product.

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