Fortifying base coat composition

Abstract

The invention relates to a nail base coat composition with photocurable properties characterized in that it comprises between 0.04 and 0.1 wt.% of vitamin C, between 0.04 and 0.1 wt.% vitamin E and between 0.08 and 0.12 wt.% hexanal, based on the total weight of the composition, and at least one monomer-free resin, preferably methacrylate monomer-free resin, the said monomer-free resin contains one or more oligomers coupled with one or more photo-initiators.. The invention also provides a method for manufacturing the composition and a method for applying the nail base coat composition to a user's nail curing it using UV or LED light, is disclosed.

Description

Fortifying Base Coat Composition Technical field

[0001] The present invention pertains to the field of cosmetic nail care products, specifically to a fortifying nail base coat that is photocurable. This invention provides a novel formulation of a photocurable nail base coat composition, a method of manufacturing and an application method for the photocurable base coat composition that enhances adhesion, durability, and overall nail health. Technical background

[0002] A nail base coat composition is a clear or tinted nail polish composition that is applied to the nails before the colored nail polish. Its primary purpose is to create a smooth surface for the colored nail polish composition to adhere to, promoting better adhesion and longevity of the manicure. Base coats also help protect the natural nails from staining that may occur when using dark or vibrant nail polish colors.

[0003] When applying a base coat, it's typically used as the first step in a three-step nail polish application process, which includes the base coat, colored polish, and a top coat for added shine and durability. Using a base coat not only enhances the appearance of the manicure but also contributes to the overall health and strength of the nails.

[0004] Using a base coat is a common step in the process of a professional or at-home manicure. It helps create a more even and polished look and can contribute to the overall health of the nails by providing a protective barrier between the natural nail and the colored polish.

[0005] Because the base coat is applied as the first layer followed by one or several other layers of nail polish the drying rate of the base coat is a crucial factor as it influences the overall application process and the time required for a manicure. Therefore, the use of traditional air-dry base coats is more and more replaced by the use of base coats having a higher drying rate, such as quick-dry base coats, photocurable base coats, spray-on base coats and heat-activated base coats.

[0006] Photocurable nail base coat compositions represent a cutting-edge innovation in nail care, designed for quick drying and enhanced performance. These formulations typically include a blend of advanced photocurable polymers, adhesion enhancers,and flexibility modifiers. The photocurable polymers enable rapid curing under ultraviolet (UV) or LED light, ensuring a fast-drying process. Adhesion enhancers contribute to a strong bond between the base coat and the natural nail, providing a durable foundation for colored nail polishes.

[0007] Presently, the use of photocurable nail compositions is almost ubiquitous in nail salons, but their use at home has also become very popular due to the development of devices used for curing (UV or LED technology).

[0008] Despite their efficiency, photocurable nail base coats have potential drawbacks, including brittleness, adhesion challenges, sensitivity to application conditions, the effects on the quality of the nail and a risk of allergic reactions. When trying to mitigate these drawbacks, different ingredients are added. However, incorporating diverse ingredients into photocurable nail compositions can pose a challenge due to the intricate balance required for effective curing, where the photochemical reactions must harmonize with the diverse functional properties of additives without compromising the overall integrity of the formulation by minimizing the risk of allergies.

[0009] The present invention is made in view of the above-mentioned drawbacks. Summary of the invention

[0010] According to a first aspect, the invention relates to a novel photocurable base coat composition. According to the invention, the terms “ photocurable base coat composition” is for a nail base composition with photocurable properties, that is to say with a light curing properties based on the present of one or more photoinitiators. The novel photocurable base coat composition comprises as active ingredients vitamin C, vitamin E and hexanal. The inventors of the present invention surprisingly have determined that a photocurable base coat composition comprising vitamin C, vitamin E and hexanal results in a stable formulation that improves the hold of the cross-linking system and the quality of the nail. More specifically, the nail polish lasts more without chipping, without the risk of allergies for the nail and after removal of the nail polish the nail aspect is healthy and the nails are not fragile. Furthermore, the nail polish applied on the base coat and / or the base coat can be easily removed using an acetone-free nail polish remover which prevents injuring the nail.

[0011] Vitamin C (Ascorbic Acid) is a potent antioxidant that helps protect the nails from oxidative stress caused by free radicals. This property contributes to maintainingthe overall health and strength of the nails. It also plays a role in collagen synthesis, which is crucial for maintaining the structural integrity of the nails. This can lead to improved nail flexibility and resilience.

[0012] Vitamin E (Tocopherol) is an antioxidant that helps protect the nails from free radical damage, preventing issues such as brittleness and peeling. It also aids in retaining moisture, promoting nail hydration. Hydrated nails are less prone to breakage and splitting.

[0013] Hexanal can contribute to the formation of a durable and resilient surface, reducing the likelihood of chipping. Hexanal can also enhance the hardness of the nails, providing a protective barrier against external stressors.

[0014] While the use of any of the above-mentioned components alone is beneficial for increasing the protection and the strength of the nail, it is crucial to exercise caution regarding the quantity added. Specifically, each of these components should be incorporated in an amount that preserves the intended properties of a nail base coat composition, and further ensures stability and effectiveness of the overall formulation.

[0015] It has been demonstrated by the inventors of the present invention that when using a composition comprising a combination of vitamin C, vitamin E and hexanal in the photocurable base coat, each of the components may be used in small amounts, ensuring increased stability of the overall product, but at the same time acting in a synergistic way in terms of benefits like improved nail quality or healthier nails post- removal. This creates a holistic approach to nail care, addressing antioxidant protection, collagen synthesis, moisture retention, and strengthening due to this synergistic effect, by limiting the allergic reactions for the users by used a minimum effective quantity of each component. According to the invention, the terms “ a minimum effective quantity “ refers to the minimum necessary amount of each component to allows the synergic effect between each of them to take kept the stability of the nails composition and have a nail composition, without risk of allergies, able to take care of the nails.

[0016] In a more specific way, a composition according to the present invention provides:

[0017] Improved Cross-Linking: The combination of vitamin C, vitamin E, and hexanal in an effective quantity to care nails in the photocurable base coat likely enhances the cross-linking of polymers in the formulation. This results in a more robust and resilient coating on the nails.

[0018] Extended Nail Polish Lifespan: The strengthened cross-linking system, combined with the individual properties of these components, contributes to a longer- lasting nail polish application. The manicure is less prone to chipping or peeling.

[0019] Post-Removal Nail Health: After removing the nail polish, the nails exhibit a healthier appearance. The antioxidant properties of vitamin C and vitamin E, along with the strengthening effects of hexanal, may contribute to nails that are not only aesthetically pleasing but also resilient and less fragile.

[0020] Limit the allergic reactions risks: The origin of each component is the most simple as possible and without component identified as causative agents for allergic side effect. Furthermore, each component, particularly active ingredients, is in the composition in the lowest amount as possible to keep the stability and the light curing properties of the nails base composition.

[0021] It has been determined that the specific contents in specific amount ensure the effect for the whole shelf life of the nail product which can be up to two years Furthermore, the specific contents ensure the easy formulation of the product hence the manufacture of the nail product can be done in common equipment without the need of using specialized equipment. Also the stability of the product is maintained for the whole shelf life, without the appearance of sediments or other modifications.

[0022] In a preferred embodiment of the present invention, the content of vitamin C is comprised between 0.04 and 0.1 wt.%, the content of vitamin E is comprised between 0.04 and 0.1 wt.%, and the content of hexanal is comprised between 0.08 and 0.12 wt.%, based on the total weight of the composition.

[0023] In another embodiment the photocurable nail base coat composition comprises at least one solvent, at least one film-forming agent, at least one plasticizer, at least one resin and optionally a rheology agent.

[0024] In a preferred embodiment the at least one solvent may be an organic solvent, preferably ethyl acetate and / or butyl acetate and / or at least one alcohol chosen from ethanol, isopropanol and butanol. In a more preferred embodiment, at least one solvent is from a vegan source.

[0025] In another preferred embodiment the at least one film-forming agent is polyvinyl butyral.

[0026] In another preferred embodiment the at least one plasticizer is tributyl citrate.

[0027] In another preferred embodiment the at least one resin is chosen from elemi resins, polyester resins; tosylamide / epoxy resins; epoxy resins; sucrose benzoate;tosylamide / formaldehyde resins, toluenesulfonamide / formaldehyde resins, or polymers and / or copolymers of these various resins. In a preferred embodiment the resin is obtained from a vegan source.

[0028] In a further preferred embodiment, the resin comprises one or more oligomers and one or more photoinitiators. In a more preferred embodiment the resin is monomer free, preferably methacrylate monomer frees.

[0029] In another embodiment the composition is colorless. In another embodiment the composition further comprises a pigment or a dye.

[0030] In a second aspect, the invention relates to a method of manufacturing the photocurable nail base coat composition according to the present invention, the method comprising the step of adding a mixture of vitamin C, vitamin E and hexanal to a composition for a base coat comprising at least one solvent, at least one film- forming agent, at least one plasticizer and at least one resin.

[0031] The manufacturing process is designed for simplicity and scalability. Utilizing common mixing equipment ensures accessibility and ease of production, making the formulation process straightforward and adaptable to different manufacturing environments.

[0032] The mixing device can be any common mixing equipment for example a stainless still bowl provided with any mixing means including but not limited to blades, impellers, or agitators. The simplicity and scalability of the manufacturing process contribute to cost-effectiveness and ease of production at various scales.

[0033] In a preferred embodiment the manufacturing process is performed at a at a temperature of less than 35ºC, preferably at room temperature to avoid breakdown of vitamin C.

[0034] In another preferred embodiment the mixing device is a stainless steel device.

[0035] In a third aspect the invention relates to a method for applying the nail care product composition according of the present invention, the method comprising the following steps: a) applying the photocurable nail base coat composition to the nail; b) curing the nail base coat composition using UV or LED light; and c) optionally applying at least one layer of another nail product.

[0036] In another aspect the invention provides a method for removing a nail care product composition according to the present invention form the nail, comprising the steps of:

[0037] Soaking each nail with an acetone-free nail polish remover composition for at least 1 min;

[0038] Rubbing sideways and away from the cuticle to remove the residues from the nail.

[0039] The composition is removed from the nails without the need of using acetone and / or drilling the nail composition. After soaking with an acetone-free nail polish remover composition for at least 1 min the nail base coat forms a loose film which shrinks in sizes and can be easily removed from the nail buy gentle rubbing. Detailed description

[0040] For the disclosure, the following definitions are given:

[0041] The terms "comprising", "comprises" and "comprised of" as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. The terms "comprising”, "comprises" and "comprised of" also include the term “consisting of”.

[0042] The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g.1 to 5 can include 1, 2, 3, 4, 5 when referring to, for example, a number of elements, and can also include 1.5, 2, 2.75 and 3.80, when referring to, for example, measurements). The recitation of endpoints also includes the recited endpoint values themselves (e.g. from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

[0043] The present invention provides a novel formulation of a photocurable nail base coat composition, a method of manufacturing and an application method for the photocurable base coat composition that enhances adhesion, durability, and overall nail health.

[0044] With reference to the first aspect, the disclosure relates to a novel photocurable base coat composition. The novel photocurable base coat composition comprises as active ingredients vitamin C, vitamin E and hexanal. The following detailed explanation highlights the synergistic effects and the resulting positive outcomes for nail health:

[0045] Improved Cross-Linking: The combination of vitamin C, vitamin E, and hexanal in an effective quantity to care nails in the photocurable base coat is designed toenhance the cross-linking of polymers within the formulation. Cross-linking refers to the formation of bonds between polymer chains, creating a more intricate and robust network. This increased cross-linking leads to a resilient coating on the nails, providing a durable and protective layer.

[0046] Extended Nail Polish Lifespan: The strengthened cross-linking system, a result of the synergistic interaction between vitamin C, vitamin E, and hexanal, contributes significantly to the longevity of the nail polish application. The enhanced durability of the coating, combined with the individual properties of each component, results in a manicure that is less susceptible to common issues such as chipping or peeling. Users can enjoy an extended lifespan of their nail polish, maintaining a polished and well- manicured appearance for an extended period.

[0047] Post-Removal Nail Health: Beyond the duration of the manicure, the holistic benefits of the synergistic composition become evident even after the nail polish is removed. The antioxidant properties of vitamin C and vitamin E play a crucial role in protecting the nails from oxidative stress, contributing to a healthier appearance. Additionally, the strengthening effects of hexanal may reduce the fragility of the nails post-removal, enhancing overall resilience.

[0048] Limit the allergic reactions risks: The origin of each component is the most simple as possible and without component identified as causative agents for allergic side effect. Furthermore, each component, particularly active ingredients, is in the composition in the lowest amount as possible to keep the stability and the light curing properties of the nails base composition.

[0049] In summary, the synergistic combination of vitamin C, vitamin E, and hexanal, in a specific amount in the photocurable base coat with monomer-free resin results in a multifaceted approach to nail care. This approach not only improves the quality of the nails during the application but also extends the lifespan of the manicure and promotes healthier nails even after removal. The formulation addresses both aesthetic and structural aspects, offering users a comprehensive solution for maintaining beautiful and resilient nails without any risk of allergic reactions.

[0050] Vitamin C (Ascorbic Acid) is a potent antioxidant that helps protect the nails from oxidative stress caused by free radicals. Vitamin C is a water-soluble vitamin and can be used as such or as a derivative due to its stability and compatibility with the formulation. For example, a skilled person may choose between a water-soluble derivative and an oil soluble derivative. Examples of water-soluble vitamin Cderivatives are, without limitation, ascorbic acid, sodium ascorbil phosphate and magnesium ascorbil phosphate. Examples of oil soluble vitamin C derivatives are, without limitation, ascorbil palmitate, ascorbil tetraisopalmitate.

[0051] Vitamin E, also known as tocopherol, is a fat-soluble vitamin with potent antioxidant properties. Vitamin E is a powerful antioxidant that helps neutralize free radicals. Free radicals can damage cells, including those in the nails, leading to issues like brittleness and peeling. It also contributes to the retention of moisture in the nails. Well-hydrated nails are more flexible and less prone to breakage and splitting. Vitamin E can be incorporated into a photocurable composition as vitamin E oil extracted from natural sources. Alternatively, it can be incorporated as a vitamin E derivate. Examples of vitamin E derivatives are, without limitation, tocopheryl acetate, tocopherol succinate, tocopheryl linoleate, tocopheryl nicotinate and tocopheryl phosphate.

[0052] Hexanal is known for its strengthening effects on the nails. It can contribute to the formation of a durable and resilient surface, reducing the likelihood of chipping. Hexanal has been shown to enhance the hardness of the nails, providing a protective barrier against external stressors.

[0053] In a preferred embodiment of the present invention, the content of vitamin C is comprised between 0.04 and 0.1 wt. %, the content of vitamin E is comprised between 0.04 and 0.1 wt. %, and the content of hexanal is comprised between 0.08 and 0.12 wt. %, based on the total weight of the composition. The combination of 0.04 to 0.1 wt. % vitamin C, 0.04 to 0.1 wt.% vitamin E, and 0.08 to 0.12 wt. % hexanal is designed to work synergistically to enhance the overall performance of the nail product. This combination addresses antioxidant protection, collagen synthesis, moisture retention, and strengthening, providing comprehensive nail care.

[0054] The specified concentrations have been determined to ensure the effectiveness of the nail product throughout its entire shelf life, which can extend up to two years and to minimize as possible the amount of components. Also they play a crucial role in maintaining the stability of the product over its entire shelf life. The formulation is designed to prevent the occurrence of sediments or any other undesirable modifications like yellowing, microbial contamination or light curing decrease. This stability ensures that the product remains consistent in quality and appearance from the time of production until its expiration date. This longevity is crucial for maintaining the product's efficacy and delivering consistent benefits to users over an extended period.

[0055] The chosen concentrations not only optimize the product's performance but also simplify the formulation process. The ease of formulation is highlighted, emphasizing that common equipment can be used without the need for specialized machinery. This streamlines the manufacturing process, making it accessible and cost-effective.

[0056] The photocurable nail base coat composition comprises at least one solvent, at least one film-forming agent, at least one plasticizer, at least one resin and optionally a rheology agent.

[0057] In a preferred embodiment the at least one solvent may be an organic solvent. The organic solvent can comprise one or more solvents chosen from: short-chain esters having from 3 to 8 carbon atoms in total, such as ethyl acetate, methyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isopentyl acetate, methoxypropyl acetate or butyl lactate, ketones which are liquid at ambient temperature, alcohols, such as ethanol, isopropanol, butanol or diacetone alcohol, linear or branched aliphatic hydrocarbons which are saturated, such as alkanes, or unsaturated, and liquid at ambient temperature, aromatic hydrocarbons, such as toluene or xylene, and their mixtures.

[0058] Preferably the organic solvent is ethyl acetate and / or butyl acetate and / or at least one alcohol chosen from ethanol, isopropanol and butanol. Ethyl acetate and butyl acetate are fast-evaporating solvents. This property allows the nail product to dry quickly upon application, reducing the waiting time for users. Alcohols also contribute to rapid evaporation. This is particularly important for nail products like base coats and top coats where quick drying is desirable. Ethyl acetate and butyl acetate are effective solvents for many nail polish resins and ingredients, providing good solubility for pigments, polymers, and additives. Alcohols can enhance solubility as well. This ensures a homogeneous formulation and even distribution of components. These solvents contribute to the smooth application of the nail product. They help in spreading the formulation evenly, facilitating a uniform coating on the nails. This is crucial for achieving a polished and professional finish. In a more preferred embodiment the organic solvent is form a vegan source. Non limitative examples include ethyl acetate from sugar cane extract and butyl acetate cassava extract.

[0059] According to the present invention the at least one film-forming agent may be a cellulose film-forming agent, preferably chosen from nitrocellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, celluloseacetate butyrate and / or cellulose acetate propionate or polyvinyl butyral. They contribute to the adhesion, wear resistance, and overall durability of nail products, ensuring a smooth and protective coating on the nails. These agents play essential roles in creating a resilient film that enhances both the aesthetic and functional aspects of nail formulations. In a more preferred embodiment, the at least one film-forming agent can be from a vegan source. Non limitative examples include nitrocellulose from cotton extract.

[0060] Among them polyvinyl butyral is preferred as a film-forming agent. It brings advantages such as strong adhesion, flexibility, clarity, chemical resistance, durability, UV stability, versatility, and efficient film formation. These characteristics collectively contribute to the overall quality and performance of nail coatings, enhancing both aesthetic and functional aspects.

[0061] Plasticizers are additives commonly used in nail polish and other coatings to impart flexibility, durability, and ease of application. They work by reducing the brittleness of the film-forming agents, allowing the film to bend and flex without cracking. In the context of nail products, plasticizers play a crucial role in enhancing the overall performance and appearance of the polish. Examples of plasticizers, without limitation, are dibutyl phthalate, dioctyl phthalate, triphenyl phosphate, camphor, and tributyl citrate. Preferably, the plasticizer is tributyl citrate (TBC). TBC is a non-phthalate plasticizer known for its low toxicity, making it a preferred choice for formulations that aim to minimize potential health risks associated with certain plasticizers. It is biodegradable, contributing to sustainability in product formulations. TBC is often odorless and colorless and is compatible with various resins and solvents commonly used in nail polish formulations. This compatibility allows for a smooth and homogeneous mixture, contributing to the overall stability of the nail product. As a plasticizer, TBC effectively enhances the flexibility of the nail polish film, reducing the likelihood of cracking or chipping. This ensures a longer-lasting and more resilient manicure.

[0062] Preferably the plasticizer is from a vegan source. Non limitative examples of plasticizer from a vegan source includes

[0063] The at least one resin may be chosen from elemi resins, tosylamide / epoxy resins; epoxy resins;; sucrose benzoate; tosylamide / formaldehyde resins, toluenesulfonamide / formaldehyde resins, or polymers and / or copolymers of these various resins. The selection of resins is a critical aspect of nail product formulations,contributing significantly to the performance, appearance, and durability of the final product. Each type of resins has its own advantages. Elemi resins, sourced from trees, offer flexibility and adherence. They contribute to the overall strength of the nail coating while enhancing its application properties. Tosylamide / epoxy resins are known for their toughness and adhesion, these resins are often used in nail products to create a strong, chip-resistant film. Epoxy resins contribute to the hardness and durability of the nail coating. They are valued for their ability to create a robust film that withstands daily wear. Polyurethane resins are known for their flexibility and durability, polyurethane resins enhance the overall resilience of nail coatings, contributing to long-lasting manicures. Sucrose benzoate is often employed for its film-forming and adhesion properties. It contributes to the overall structure and wear resistance of the nail product. Tosylamide / formaldehyde resins and toluenesulfonamide / formaldehyde resins are valued for their adhesion and toughness, providing a sturdy foundation for nail coatings. In a more preferred embodiment, the resin is from a vegan source.

[0064] According to the invention, in the nail base composition, there are the incorporation of resins that contain one or more oligomers, coupled with the addition of photoinitiators. This sophisticated combination is designed to leverage the benefits of photopolymerization or photocuring processes, introducing several advantages that enhance the overall performance and user experience of nail products.

[0065] Oligomers are intermediate-sized molecules, often composed of a small number of monomer units. Their inclusion contributes to the formulation's viscosity, aiding in the application and adherence of the product. All oligomers, preferably oligomers of natural origin, known to that skilled person, for nail composition, are possible in this present invention, in particular dimer, trimer, tetramer, and pentamer molecule.

[0066] Photoinitiators are compounds that facilitate the initiation of the photopolymerization process. When exposed to light, photoinitiators generate reactive species that initiate the cross-linking of monomers and oligomers, leading to the formation of a cured film. The quick curing associated with photoinitiators helps minimize the risk of smudging or denting the freshly applied nail product. Examples of photoinitiators include, without limitation, Benzoin Methyl Ether (BME), Benzoin Ethyl Ether (BEE), Benzoin Isobutyl Ether (BIE), Benzoin Benzyl Ether (BBE), Camphorquinone (CQ), Irgacure 819™ (Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide), Irgacure 184™ (1-Hydroxycyclohexyl phenyl ketone), Darocur 1173™ (2-Hydroxy-2-methyl-1-phenyl-propan-1-one), Lucirin TPO™ (2,4,6-Trimethylbenzoyl- diphenyl-phosphine oxide), Darocur 4265™ (Tris(2-hydroxyethyl) isocyanurate triacrylate), Thioxanthone, Benzoin O-ethyl Ether (BOEE), Ethyl 4- dimethylaminobenzoate (EDMAB) and Ethyl Trimethylbenzoylphenylphosphinate (TPO). Preferably the photoinitiator is ethyl trimethylbenzoylphenylphosphinate

[0067] The incorporation of oligomers, and photoinitiators enhances the efficiency of the application process. Users can experience a faster and more convenient application, reducing the time required for drying. The advanced formulation contributes to the creation of a cured film with enhanced hardness and durability. This results in a longer-lasting manicure, reducing the frequency of touch-ups or reapplications.

[0068] According to the invention, the resin is monomer-free, with a particular preference for being methacrylate monomer-free. Monomers, and particularly methacrylate monomers, have been identified as causative agents for allergic side effects associated with the use of curable compositions. Allergic reactions, ranging from mild irritation to more severe responses, have been linked to the presence of these monomers in various curable formulations.

[0069] Methacrylate monomers, commonly used in the synthesis of resins and polymers, have been recognized as potential allergens, triggering adverse skin reactions and sensitivities. In the context of curable compositions, these monomers may come into direct contact with the skin during application and curing processes, leading to undesirable health effects.

[0070] To address this concern and enhance user safety, the formulation in this embodiment excludes monomers, specifically targeting the elimination of methacrylate monomers. This not only reduces the risk of allergic reactions but also contributes to the overall biocompatibility of the curable composition and improve the synergic effect of the active principles of vitamin A, vitamin E and hexanal without impact the light curing properties. By opting for a methacrylate monomer-free resin, the formulation aims to provide a safer and more user-friendly product, minimizing the potential for skin sensitivities and adverse health effects associated with traditional curable compositions containing such monomers.

[0071] In another embodiment, the composition is colorless. According to the invention, the term “colorless” refers to a composition without pigment or dye. In another embodiment the composition further comprises a pigment or a dye.

[0072] With reference to the second aspect of the invention which relates to a method of manufacturing the photocurable nail base coat composition according to the present invention, wherein the method comprises the step of adding a mixture which comprises between 0.04 and 0.1 wt.% of vitamin C, between 0.04 and 0.1 wt.% vitamin E and between 0.08 and 0.12 wt.% hexanal, based on the total weight of the mixture, and at least one monomer-free resin that contains one or more oligomers coupled with one or more photo- initiators to a composition for a base coat comprising at least one solvent, at least one film-forming agent, and at least one plasticizer. The manufacturing process is designed for simplicity and scalability. Utilizing common mixing equipment ensures accessibility and ease of production, making the formulation process straightforward and adaptable to different manufacturing environments.

[0073] To begin the manufacturing process, the components of the nail product composition, including solvents, film-forming agents, plasticizers, and other optional ingredients, are carefully measured and added to the mixing equipment in the corresponding step. The order of addition and mixing duration are optimized to ensure homogeneity and uniform distribution of ingredients.

[0074] The mixing device, such as a stainless-steel bowl equipped with mixing means, facilitates the thorough blending of the components. The choice of mixing equipment allows for flexibility in adapting to different production volumes while maintaining consistent product quality.

[0075] Once all components are added, the mixing process is initiated, ensuring that the ingredients are uniformly dispersed, and that the formulation achieves the desired consistency.

[0076] After the mixing process is complete, the resulting formulation is ready for further processing. The formulation is then dispensed into appropriate packaging, such as bottles or tubes, ready for distribution and use.

[0077] The simplicity of the manufacturing process, combined with the use of common mixing equipment, not only streamlines production but also makes it feasible for manufacturers of various scales to produce the nail product composition. This adaptability allows for efficient manufacturing in both small batches and large-scale production settings.

[0078] The mixing device can be any common mixing equipment for example a stainless still bowl provided with any mixing means including but not limited to blades,impellers, or agitators. The simplicity and scalability of the manufacturing process contribute to cost-effectiveness and ease of production at various scales.

[0079] In a preferred embodiment the manufacturing process is performed at a at a temperature of less than 35ºC, preferably at room temperature to avoid breakdown of vitamin C, to avoid denaturation or destructuring of vitamin E, haxanal and others components.

[0080] In another preferred embodiment the mixing device is a stainless steel device.

[0081] With reference to the third aspect the present invention relates to a method for applying the nail base coat composition with photocurable properties of the present invention, the method comprising the following steps: a) applying the nail base coat composition with photocurable properties to the nail; b) curing the nail base coat composition using UV or LED light; and c) optionally applying at least one layer of another nail product.

[0082] This method is designed to provide a systematic and effective approach to achieving optimal results in nail care.

[0083] With reference to step a) Applying the Nail Base Coat Composition with photocurable properties to the Nail

[0084] The base coat is applied to the nail with the use of a brush in a thin and uniform layer to cover essentially all the nail surface. Careful and precise application of the photocurable nail base coat is crucial for optimal results. Even coverage ensures uniform curing and fortification of the nails.

[0085] Before applying the base coat, the step may encompass that firstly the nails are prepared ensuring they are clean and dry. The application of a layer of treatment to the nail surface is also envisaged.

[0086] With reference to step b) Curing the Nail Base Coat Composition using UV or LED Light:

[0087] Following the application of the photocurable nail base coat, the next step involves the curing process. This is achieved by exposing the coated nails to UV or LED light sources. The exposure to UV or LED light triggers the photopolymerization process, leading to the formation of a durable and resilient film on the nails.

[0088] UV curing involves the use of ultraviolet light, typically in the UVA spectrum (320–400 nm). Traditional UV lamps emit a broad spectrum of UV light, with a significant portion falling within the UVA range. The optimal wavelength for UV curing in the nail industry is around 365 nm. UV curing may take longer compared to LEDcuring, typically ranging from 2 to 4 minutes. However, advancements in UV lamp technology have led to quicker curing times in some cases.

[0089] LED curing utilizes light-emitting diodes that emit a specific wavelength of light. In the context of nail care, LED lamps primarily emit light in the UVA range, typically around 365 nm, similar to UV lamps. LED lamps used for nail care are designed to emit light at the specific wavelength required for the curing of photopolymerizable nail products. LED curing is known for its rapid curing times. The process is significantly quicker compared to traditional UV curing, with typical curing times ranging from 30 seconds to 1 minute. LED lamps are more energy-efficient than traditional UV lamps, consuming less power and producing less heat during the curing process. LED lamps have a longer lifespan compared to traditional UV lamps, making them a durable and cost-effective choice.

[0090] In a more preferred embodiment, the curing is made using LED light. Preferred examples of voltages and times are using a 24 W LED lamp for 2 minutes, using a 36 W LED lamp for 1 minute or using 36 W LED lamp for 1 minute. The nail composition is strengthened enough to remain on the nails for at least 2 weeks, without chirping.

[0091] With reference to step c) Optionally Applying at Least One Layer of Another Nail Product:

[0092] This step allows for further customization and creativity in nail styling. After curing the base coat, users have the option to apply additional layers of different nail products. Users may choose to apply colored nail polish, nail art designs, or additional protective layers, depending on their preferences. The cured base coat provides a stable foundation for the application of other nail products.

[0093] The method outlined in the third aspect of the invention provides a systematic approach to nail care, emphasizing fortification, durability, and creative expression. Through the application of the photocurable nail base coat and optional additional layers, users can achieve enhanced nail aesthetics while benefiting from the protective and fortifying features of the formulated base coat.

[0094] With reference to the fourth aspect of the invention, namely a method for gently and efficiently removing a nail care product composition according to the present invention form the nail, comprising the steps of:

[0095] Soaking each nail with an acetone-free nail polish remover composition for at least 1 min;

[0096] Rubbing sideways and away from the cuticle to remove the residues from the nail.

[0097] The acetone-free nail polish remover composition can be any known acetone- free removal composition suitable for removing cured compositions. Non limitative examples include compositions based on ethyl acetate, alcohol or a combination thereof. In a further preferred embodiment the acetone-free nail polish remover composition is enriched with castor oil.

[0098] In a further embodiment the soaking is made by applying a material impregnated with the acetone-free nail polish remover composition. The material can be a textile material, for example cotton. In a further preferred embodiment the impregnated material is fixed to the nail plate, preferably using pliers. Experimental section

[0099] To assess the stability of the nail base coat composition with photocurable properties of the invention, the applicant tests different compositions indicated in table 1, based on a reference control composition named Green Flash TM that were added different components.

[0100] The Green Flash™ base is a base coat composition comprising: ethyl acetate, butyl acetate, polyvinyl butyral, bis-hema poly(1,4-butanediol)-9 / ipdi copolymer, tosylamide / epoxy resin, styrene / acrylates copolymer, ethyl trimethylbenzoyl phenylphosphinate, tributyl citrate, isopropyl alcohol, phosphoric acid, bht. In this Green Flash ™ base coat composition, ethyl trimethylbenzoyl phenylphosphinate correspond to the photo- initiators,

[0101] Hereinafter, table 1, show for each composition tested, the amount of other components added in the Green Flash™ base coat composition, expressed wt% based on the total weight of the final composition.

[0102] Table 1 Name Additional compound added in Green Flash TM (wt. %)Function in Test1NothingGreen Flash™ base coat composition:reference Control composition 2 0.05 wt. % of vitamin E Control Vit E 3 0,05 wt.% of vitamin C Control Vit C 4 0,01 wt. % of hexanal Control hexanal5 0.05 wt. % of vitamin E and 0,05 wt.% of vitamin CControl Vit E + C6 0,05 wt.% of vitamin C and 0,01 wt. % of hexanal Control Vit C + hexanal 7 0.05 wt. % of vitamin E and 0,01 wt. % of hexanal Control Vit E + hexanal 8 0,05 wt.% of vitamin C and 0,01 wt. % of hexanal and 0.05 wt. % of vitamin E Composition according to the invention

[0103] In others words, for this experimental test, to a Green Flash™ base coat composition comprising: ethyl acetate, butyl acetate, polyvinyl butyral, bis-hema poly(1,4-butanediol)-9 / ipdi copolymer, tosylamide / epoxy resin, styrene / acrylates copolymer, ethyl trimethylbenzoyl phenylphosphinate, tributyl citrate, isopropyl alcohol, phosphoric acid, bht, vitamin C, vitamin E and hexanal were added in an amount of 0.05 wt. %, 0.05 wt. %and 0,1 wt. %, respectively, based on the total weight of the final composition to obtain a composition according to the present invention.

[0104] More particularly, the following tests can be used to assess the stability of the product of this invention:

[0105] To test the general stability: Each of compositions 1 to 8 mentioned in table 1 was packaged in glass bottles and stored in an oven at 50° C for a month. The color of each composition is subsequently compared with the reference control (composition 1 of table 1) of Green Flash™ base coat composition that does not contain the active principle.

[0106] In the condition of the trial, after a month in a oven at 50°C, the colors of each composition 2 to 7 has a significant change to compare to the reference control. As used herein, the term a “significant change” refers to a visible color change of the composition, combined for example with a turbid visual appearance. On the contrary, the composition 8, according to the invention does not present any suitable transformation to compare to the Green flash™ base coat composition. Therefore, the general stability of the composition according to the invention is similar to the stability of the reference control.

[0107] To test Yellowing stability: Each of compositions 1 to 8 mentioned in table 1 was packaged in glass bottles are left in an oven at 50° C and at ambient temperature (20° C.) for a month for a comparative study of the stability. This stability is evaluated visually (color / yellowing). In the condition of the trial, the color andyellowing of each composition, 2 to 7 has a significant change to compare to the reference control composition 1. The results show that the composition 8, according to the invention, does not present any significant color or yellowing transformation in comparison with the Green flash™ base coat composition 1. In fact, a significant yellowing is visible in compositions 2 to 7, particularly in composition, which contains vitamin C and / or E. Therefore, the yellowing of the composition according to the invention, which comprises vitamin C, vitamin E, hexanal and a monomer-free resin contains oligomer(s) coupled with photo- initiator(s), does not occur in the condition of the trial.

[0108] To test Stability to sedimentation: The products packaged in glass bottles are left in an oven at 50° C. and at ambient temperature (20° C.) for a month for a comparative study of the stability. This stability is evaluated visually (presence of particles at the bottom of the bottle). The pearly shade is particularly suitable for this type of monitoring. In the end of trial, each composition 1 to 7 has many particles in the bottle, contrary to the composition 8 of the invention. Therefore, the composition of the invention is stable and does not present sedimentation instability.

[0109] When compared to the Green flash™ base coat composition the composition according to the invention is stable and does not undergo any unsuitable transformation.

[0110] The same experiments are carried out with component quantities outside the % range of vitamin C, vitamin E and hexanal. The results showed that for percentages outside the range, the formulation balance was modified causing instability of the composition over time..

[0111] With quantities of vitamin C, vitamin E and haxanal outside of these ranges, in the condition of the above-mentioned trial, the compositions have many sedimentation particles, yellowing, and loss of the photocurable effect.

[0112] This experimental results shows that the specific components of vitamin C, vitamin E , hexanal in the specific weight %, with a monomer-free resin that contains oligomers coupled with one or more photo initiators is a stable nail care base coat composition, with photocurable properties, without risk of allergies significant for users.

[0113] Furthermore, the active principles in the specific amount allow to take care of the nails while increasing the stability of the composition.

[0114] The nail base coat composition with photocurable properties of this invention provided fortifying, stable, allergies-free risks, care nail composition, and is a good alternative of existed nail photocurable compositions.

Claims

Claims 1. A nail base coat composition with photocurable properties characterized in that it comprises, as active principle, between 0.04 and 0.1 wt.% of vitamin C, between 0.04 and 0.1 wt.% vitamin E and between 0.08 and 0.12 wt.% hexanal, based on the total weight of the composition; and; at least one monomer-free resin, preferably methacrylate monomer-free resin, the said monomer-free resin contains one or more oligomers coupled with one or more photo- initiators.

2. The composition, according to claim 1, wherein the content of vitamin C is 0.05 wt.%, the content of vitamin E is 0.05 wt.%, and the content of hexanal is 0.1 wt.%, based on the total weight of the composition.

3. The composition, according to any of claims 1or 2, wherein the composition comprises at least one solvent, at least one film-forming agent, at least one plasticizer, at least one resin and optionally a rheology agent.

4. The composition, according to claim 3, wherein the at least one solvent is an organic solvent, preferably ethyl acetate and / or butyl acetate and / or at least one alcohol chosen from ethanol, isopropanol and butanol.

5. The composition, according to any of claims 3 or 4, wherein the at least one film-forming agent is a cellulose film-forming agent, preferably chosen from nitrocellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, cellulose acetate butyrate and / or cellulose acetate propionate or polyvynyl butyral.

6. The composition, according to any of claims 3 to 5, wherein the at least one plasticizer is tributyl citrate.

7. The composition, according to any of claims 3 to 6, wherein the at least one monomer-free resin is chosen from polyvinyl butyral resins, shellac resins, elemi resins, alkyd resins, polyester resins; tosylamide / epoxy resins; epoxy resins; acrylate resins; styrene-acrylate resins; polyurethane resins; sucrose benzoate; tosylamide / formaldehyde resins, toluenesulfonamide / formaldehyde resins, or polymers and / or copolymers of these various resins.

8. The composition, according to any one of the previous claims, wherein the photo- initiators is selected from the group comprising Benzoin Methyl Ether(BME), Benzoin Ethyl Ether (BEE), Benzoin Isobutyl Ether (BIE), Benzoin Benzyl Ether (BBE), Camphorquinone (CQ), Irgacure 819™ (Phenylbis(2,4,6- trimethylbenzoyl)phosphine oxide), Irgacure 184™ (1-Hydroxycyclohexyl phenyl ketone), Darocur 1173™ (2-Hydroxy-2-methyl-1-phenyl-propan-1-one), Lucirin TPO™ (2,4,6-Trimethylbenzoyl-diphenyl-phosphine oxide), Darocur 4265™ (Tris(2-hydroxyethyl) isocyanurate triacrylate), Thioxanthone, Benzoin O-ethyl Ether (BOEE), Ethyl 4-dimethylaminobenzoate (EDMAB) and Ethyl Trimethylbenzoylphenylphosphinate (TPO) or a mixed therefore.

9. The composition, according to any of the previous claims, wherein the composition further comprises a pigment or a dye.

10. The composition, according to any of claims 1 to 9, wherein the composition is without any pigment or dye.

11. Method for manufacturing the nail base coat composition according to any of the previous claims, comprising the step of adding a mixture which comprises between 0.04 and 0.1 wt.% of vitamin C, between 0.04 and 0.1 wt.% vitamin E and between 0.08 and 0.12 wt.% hexanal, based on the total weight of the mixture, and at least one monomer-free resin that contains one or more oligomers coupled with one or more photo- initiators ,to a composition for a base coat comprising at least one solvent, at least one film-forming agent, and at least one plasticizer.

12. The method, according to claim 12, which is performed at a temperature of less than 35ºC, preferably at room temperature.

13. A method for applying a nail base coat composition according to any of claims 1 to 11 to a nail of a user, the method comprising the following steps: a) applying the nail base coat composition to the nail; b) curing the nail base coat composition using UV or LED light; and c) optionally applying at least one layer of another nail product.

14. A method of removing a nail care product composition according to any of claims 1-11 from the nail, comprising the steps of: a) soaking each nail with an acetone-free nail polish remover composition for at least 1 min;b) rubbing sideways and away from the cuticle to remove the residues from the nail.