Nail coatings based on photocurable compositions

Abstract

A photocurable composition useful for forming a durable impact-resistant coating on nails comprising: a). at least one (meth)acrylate functionalized monomer; b). at least one (meth)acrylate functionalized oligomer; c). at least one particle of a core / shell copolymer; and d). at least one photoinitiator.

Description

Technical Field

[0001] The present invention relates to nail coatings obtained from certain photocurable compositions comprising impact-modified core / shell copolymers and having enhanced mechanical properties and durability, methods of forming nail coatings from such photocurable compositions, articles comprising containers and such photocurable compositions contained therein, and kits comprising packaged photocurable compositions and instructions for preparing nail coatings therefrom. Background Art

[0002] Acrylic nail formulations are well known and can help enhance the appearance of nails (e.g., human fingernails and toenails) by allowing the user to shape the formulation into various configurations. Traditional acrylic nail formulations consist of two parts: 1) a photocrosslinkable liquid monomer and 2) an acrylic polymer powder containing an activator / initiator. These two components are mixed together and applied to the nails for shaping and sculpting by a manicurist using various tools. Acrylic nails made from such traditional formulations can be brittle and suffer from low impact strength. Impact resistance is important in the context of nail grooming because consumers expect acrylic nails to be durable and able to withstand external forces for extended periods of time without cracking, breaking, chipping, or otherwise deteriorating in appearance.

[0003] In recent years, new nail formulations have been developed that are one-part systems comprising photocurable oligomers, photocurable monomers, pigments and possibly one or more other additives. Such formulations will typically have a viscosity similar to that of conventional nail polish and can be applied to the nail surface in much the same manner as conventional nail polish and then cured in situ using ultraviolet (UV) radiation to obtain a protective / decorative coating that can typically last up to fourteen days. Such formulations may be referred to as "UV gel nail polishes" and are described in, for example, U.S. Patent Nos. 8901199B2; 8367742B2; and 9084738B2. Hybrid variants based on UV gel nail polishes and conventional acrylic nail formulations have been disclosed, in which the UV gel nail polish formulation is supplemented with a polymer powder, such as a powder based on polymethyl methacrylate (PMMA). Such a powder has a particle size of at least 1 micron (i.e., at least 1000nm). See, e.g., U.S. Patent No. 6,244,274 B2; U.S. Patent Publication No. 2018 / 0092827 A1; and WO 2017 / 217983 A1.

[0004] Despite such advances in nail coating technology, there remains a need for improved formulations that, when cured, provide nail coatings having increased durability and resistance to external forces, such as impact forces. Summary of the invention

[0005] The present invention utilizes a photocurable composition comprising at least the following components:

[0006] a). at least one (meth)acrylate functionalized monomer;

[0007] b). at least one (meth)acrylate functionalized oligomer;

[0008] c) particles of at least one core / shell copolymer; and

[0009] d). At least one photoinitiator.

[0010] Such compositions can be clear or pigmented and are formulated to be useful as a one-way system, i.e., a formulation that can be applied to a nail surface and then cured by exposure to actinic radiation (e.g., UV or visible light) without first being admixed with a second component. By including core / shell copolymer particles in a photocurable composition, the mechanical properties and durability of the resulting nail coating can be significantly improved compared to a cured nail coating prepared using a similar formulation that does not include such core / shell copolymer particles. Additionally, due to their small size, these impact-modified core / shell copolymer particles can have little to no effect on the optical clarity of the cured product, which is not the case for PMMA-based particles that are larger than 1 micron in size.

[0011] The photocurable compositions may be formulated to have the following further attributes or properties:

[0012] 1). Relatively high viscosity and liquid consistency, which allows the composition to be easily applied to the nail surface and molded into a desired configuration of significant thickness without running or dripping before light curing;

[0013] 2). No need to mix with other components before application and curing;

[0014] 3). A high degree of homogeneity and physical stability (e.g., little or no tendency for the components of the composition to separate, even during long-term storage);

[0015] 4) Long open time (allowing for extended nail shaping period);

[0016] 5). Low odor;

[0017] 6). Low shrinkage during curing;

[0018] 7). High transparency after curing (when cured); and / or

[0019] 8). Low volatile content (ie, little or no non-reactive solvents).

[0020] The present invention provides a coating on a nail, wherein the coating is a photocured product of such a photocurable composition.

[0021] The present invention also provides a method for forming a coating on a nail, comprising the steps of:

[0022] a) placing a photocurable composition as described herein on the nail surface; and

[0023] b) exposing the photocurable composition to actinic radiation, in particular UV or visible light.

[0024] The present invention also provides a packaged product (kit), wherein the packaged product comprises a container and a photocurable composition as described herein disposed within the container, wherein the packaged product has a dispensing member capable of dispensing the photocurable composition from the container.

[0025] The present invention further provides a kit comprising: a packaged article comprising a container and a photocurable composition as described herein disposed within the container, at least one application device, and instructions for dispensing, applying and curing the photocurable composition to provide a nail coating. DETAILED DESCRIPTION

[0026] The present invention employs a photocurable composition comprising, consisting essentially of, or consisting of:

[0027] a). at least one (meth)acrylate functionalized monomer;

[0028] b). at least one (meth)acrylate functionalized oligomer;

[0029] c) particles of at least one core / shell copolymer; and

[0030] d). At least one photoinitiator.

[0031] One or more additional components may additionally be present, in particular pigments and / or colorants and possibly (meth)acrylic polymers, as described in more detail below. The photocurable composition is used to form a cosmetic nail coating and may be a liquid having a relatively high viscosity at room temperature, which allows the photocurable composition to be applied to a nail surface (i.e., nail plate) and then easily shaped (shaped) by a nail technician or other operator into a desired configuration on the nail surface, followed by exposure to ultraviolet (UV) light or other actinic radiation to photopolymerize the shaped photocurable composition to form a hard, durable, impact-resistant nail coating. Alternatively, the photocurable composition may be a liquid having a relatively low viscosity at room temperature, which allows the photocurable composition to be easily applied to a nail surface (i.e., nail plate) as a thin layer, followed by exposure to ultraviolet (UV) light or other actinic radiation to photopolymerize the thin layer of the photocurable composition to form a hard, durable, impact-resistant nail coating. In particular, the presence of the core / shell copolymer particles helps to significantly improve the impact properties (ie, resistance to chipping, cracking, scratching) of the cured coating while maintaining good optical clarity and high gloss over time.

[0032] Core / Shell Copolymers

[0033] The core / shell copolymers useful in the context of the present invention can be generally described as polymeric substances, which are typically in particulate form (granular form), which include a core (interior) comprising a first polymer ("core polymer") and at least one shell (exterior) comprising a second polymer ("shell polymer") substantially or completely surrounding the core. Typically, the shell polymer has a glass transition temperature that is higher than the glass transition temperature of the core polymer. The glass transition temperature of the polymers of the core / shell copolymer can be measured according to standard ISO 11357-2:199. Generally speaking, the glass transition temperature of the core polymer is preferentially less than 20°C, less than 10°C or less than 0°C, for example between -140°C and 0°C. Preferentially, the glass transition temperature of the shell polymer is greater than 20°C or greater than 30°C, for example between 30°C and 250°C. According to various embodiments of the present invention, the difference between the glass transition temperatures of the core polymer and the shell polymer may be at least 10°C, at least 20°C or at least 30°C. Thus, the core polymer can be considered a "soft" polymer (and can be elastic or rubbery in nature), while the shell polymer can be considered a "hard" (non-elastic) polymer.

[0034] The shell portion of the core / shell copolymer may preferably include in polymerized form: alkyl methacrylates such as methyl methacrylate wherein the alkyl chain comprises 1 to 12 carbon atoms (i.e., C1-C12 alkyl methacrylates) and preferably 1 to 4 carbon atoms; and / or vinyl aromatic organic compounds such as styrene comprising 6 to 12 carbon atoms; and / or acrylonitrile. The shell portion of the core / shell copolymer may or may not be crosslinked.

[0035] The core of the core / shell copolymer advantageously comprises in polymerized form a conjugated diene (e.g. butadiene) comprising 4 to 12 and preferably 4 to 8 carbon atoms; or an alkyl acrylate (e.g. butyl acrylate) wherein the alkyl chain comprises 1 to 12 and preferably 1 to 8 carbon atoms. The alkyl chain may be a linear alkyl chain or a branched alkyl chain.

[0036] The core / shell copolymer may be selected, for example, from: a core comprising butadiene (in polymerized form) and a shell comprising methyl methacrylate, ethyl acrylate, butyl acrylate, methacrylic acid and / or styrene (in polymerized form); a core comprising butyl acrylate, n-octyl acrylate and / or 2-ethylhexyl acrylate (in polymerized form) and a shell comprising methyl methacrylate (in polymerized form); or a core comprising butadiene (in polymerized form) and a shell comprising a mixture of acrylonitrile and styrene (in polymerized form). In the aforementioned embodiment, the butadiene constituting the core may be copolymerized with styrene.

[0037] The following types of core / shell copolymers are examples of core / shell copolymers that are particularly suitable for use in the present invention:

[0038] a). a core / shell copolymer comprising, consisting essentially of, or consisting of a core comprising, consisting essentially of, or consisting of butyl acrylate in polymerized form (e.g., a homopolymer of butyl acrylate or a copolymer of butyl acrylate and at least one comonomer, wherein the copolymer comprises at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% by weight of butyl acrylate in polymerized form) and a shell comprising, consisting essentially of, or consisting of methyl methacrylate in polymerized form (e.g., a homopolymer of methyl methacrylate or a copolymer of methyl methacrylate and at least one comonomer, wherein the copolymer comprises at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% by weight of methyl methacrylate in polymerized form); and

[0039] b). a core / shell copolymer comprising, consisting essentially of, or consisting of a core and a shell, wherein the core comprises, consists essentially of, or consists of styrene and butadiene in copolymerized form (e.g., a copolymer of butadiene and styrene, optionally copolymerized with at least one additional comonomer in an amount of up to 10 wt. %, based on the weight of the copolymer), and the shell comprises, consists essentially of, or consists of methyl methacrylate in polymerized form (e.g., a homopolymer of methyl methacrylate or a copolymer of methyl methacrylate and at least one comonomer, wherein the copolymer contains at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% by weight of methyl methacrylate in polymerized form).

[0040] The mass amount of the core is advantageously in the range of 10% to 99%, for example 60% to 95%, of the total mass of the core / shell copolymer. The particle size of the core / shell copolymer is less than 1000 nm, advantageously between 10 and 900 nm, between 25 and 700 nm or between 40 and 600 nm.

[0041] Examples of core polymers that may be mentioned include rubbers; polysiloxanes; homopolymers and copolymers of butadiene, butyl acrylate, methyl methacrylate, ethyl acrylate, 2-ethylhexyl acrylate and / or butyl acrylate; isoprene homopolymers; isoprene-butadiene copolymers; copolymers of isoprene with not more than 98% by weight of vinyl monomers; and copolymers of butadiene with not more than 98% by weight of vinyl monomers. The vinyl monomer may be styrene, alkylstyrene, acrylonitrile, alkyl (meth)acrylate, alkyl acrylate, butadiene or isoprene. The core polymer may also include siloxanes, which are optionally copolymerized with alkyl acrylates. The core of the core / shell copolymer may be completely or partially crosslinked. To achieve crosslinking, at least difunctional monomers may be added during the preparation of the core, and these monomers may be selected from poly (meth)acrylates of polyols, such as di (meth)acrylate butanediol and trimethylolpropane trimethacrylate. Other polyfunctional monomers are, for example, divinylbenzene, trivinylbenzene, vinyl acrylate and vinyl methacrylate, and triallyl cyanurate. The core can also be crosslinked by introducing unsaturated functional monomers such as unsaturated carboxylic anhydrides, unsaturated carboxylic acids and unsaturated epoxides therein via grafting or as comonomers during polymerization. Examples that may be mentioned include maleic anhydride, (meth)acrylic acid and glycidyl methacrylate. Crosslinking can also be carried out by utilizing the inherent reactivity of monomers such as dienes.

[0042] The core / shell copolymer may comprise a single shell or multiple shells (i.e., two or more shells), wherein the shells may differ in their monomer composition, molecular weight, degree of crosslinking or other characteristics. The shell of the core / shell copolymer may be, for example, a homopolymer or copolymer of styrene, alkylstyrene, (meth) acrylic acid C1-C4 alkyl ester, methyl methacrylate, butyl acrylate, ethyl acrylate, or a copolymer comprising at least 70% by weight of one of the aforementioned monomers and at least one comonomer selected from the other aforementioned monomers, other (meth) acrylic acid alkyl esters, vinyl acetate and acrylonitrile. The shell may be functionalized by introducing unsaturated functional monomers (e.g., unsaturated carboxylic acid anhydride, unsaturated carboxylic acid and unsaturated epoxide) therein as comonomers via grafting or during polymerization. Examples that may be mentioned include maleic anhydride, (meth) acrylic acid, glycidyl methacrylate, hydroxyethyl methacrylate and alkyl (meth) acrylamide. Examples that may be mentioned include core / shell copolymers with shells made of polystyrene and core / shell copolymers with shells made of PMMA. The shell may also contain imide functional groups (by copolymerization with maleimide or by chemically modifying PMMA with primary amines). Advantageously, the molar percentage of imide functional groups is 30% to 60% (relative to the shell as a whole). A core / shell copolymer comprising two shells may also be used, wherein one shell is made of polystyrene and the other shell on the outside is made of PMMA. Examples of core / shell copolymers and processes for preparing them are described in the following patents, each of which is incorporated herein by reference in its entirety for all purposes: U.S. Patent Nos. 4,180,494, 3,808,180, 4,096,202, 4,260,693, 3,287,443, 3,657,391, 4,299,928, 3,985,704, 5,773,520.

[0043] According to certain embodiments, the core may be 5% to 95%, 50% to 95%, or 60% to 90% by mass of the core / shell copolymer, and the shell may be 95% to 5%, 50% to 5%, or 40% to 10% by mass of the core / shell copolymer.

[0044] Polymers referred to in the art as "multistage polymers" may also be used as the core / shell copolymer component of the photocurable composition of the present invention. Multistage polymers are described, for example, in the following published applications, each of which is incorporated herein by reference in its entirety for all purposes: WO 2016 / 102666; US 2017 / 0369696; WO 2017 / 121749; WO 2017 / 121750; WO 2017 / 220791; WO 2018 / 002259; WO 2018 / 002260; WO 2018 / 002273; FR 1756649; and FR 1756647.

[0045] The amount of the core / shell copolymer included in the photocurable composition may be changed as desired depending on the type of core / shell copolymer used, the target properties of the cured nail coating, and the type of polymerized organic substance (polymerized organic substance) used, and possibly other factors. According to aspects of the present invention, the photocurable composition may include at least 1%, at least 5%, or at least 10% of the core / shell copolymer by weight, based on the total weight of the photocurable composition. In other aspects, the photocurable composition may include no more than 50%, no more than 45%, or no more than 40% of the core / shell copolymer by weight, based on the total weight of the photocurable composition. Therefore, the photocurable composition may, for example, include 1 to 50%, 5 to 45%, or 10 to 40% of particles of at least one core / shell copolymer by weight, based on the total weight of the photocurable composition.

[0046] According to certain embodiments, the photocurable composition may include 1 to 200, 5 to 100, or 15 to 70 parts by weight of the core / shell copolymer per 100 parts by weight of the total weight of the polymerized organic substance (e.g., the total weight of polymerized monomers (polymerized monomers) + polymerized oligomers (polymerized oligomers)).

[0047] Core / shell copolymers suitable for use in the present invention include those sold by Arkema under the trade name and Core / shell copolymers for sale.

[0048] An important advantage achieved by using the core / shell copolymers described above is that such core / shell copolymers exhibit little or no tendency to impart haze to cured nail coatings prepared from the photocurable compositions according to the present invention. Thus, photocurable compositions containing such core / shell copolymer particles can be formulated that are capable of providing highly transparent cured nail coatings after photocuring, even at relatively high loadings of the core / shell copolymer.

[0049] (Meth)acrylic polymer

[0050] The photocurable compositions of the present invention may optionally include one or more (meth)acrylic polymers. However, such (meth)acrylic polymers are not required and the present invention also contemplates photocurable compositions that do not contain any (meth)acrylic polymers. As used herein, the term "(meth)acrylic polymer" means a polymer that does not have a core / shell structure and includes one or more (meth)acrylic monomers (in polymerized form), wherein the (meth)acrylic monomers constitute 50 wt % or more of the (meth)acrylic polymer. As used herein, the term "(meth)acrylic monomer" means any type of polymerizable monomer containing one or more acrylic and / or methacrylic functional groups.

[0051] The presence of a (meth) acrylic polymer in a photocurable composition can help promote the dispersion and stabilization of the core / shell copolymer in both the photocurable composition and the cured article prepared therefrom. In the absence of a (meth) acrylic polymer, the core / shell copolymer, typically in the form of particles, can tend to aggregate and settle out of the photocurable composition (making the photocurable composition heterogeneous). Therefore, including a (meth) acrylic polymer can result in a homogeneous dispersion of the core / shell copolymer in the photocurable composition, which promotes the formation of a homogeneous cured article prepared by curing the photocurable composition. An ideal homogeneous dispersion of the core / shell copolymer in the matrix has no aggregates after the core / shell copolymer is combined with monomers and oligomers (which can be collectively referred to as "polymerized organic substances"). Therefore, a liquid photocurable composition comprising a (meth) acrylic polymer, a core / shell copolymer, and a polymerized organic substance can have or present a better dispersion of the core / shell copolymer than a similar composition not including a (meth) acrylic polymer. Further, a liquid photocurable composition including a (meth)acrylic polymer, a core / shell copolymer, and a polymeric organic material may be less viscous than a similar composition not including a (meth)acrylic polymer.

[0052] The molecular weight of the (meth)acrylic polymer is not particularly limited and may be varied as needed or desired to impart certain characteristics or properties to the photocurable composition and / or the cured article prepared therefrom. The (meth)acrylic polymer may, for example, have a weight average molecular weight of 2000 g / mol to 1,000,000 g / mol.

[0053] In a first embodiment, the (meth)acrylic polymer may have a weight average molecular weight (Mw) of at least 100,000 g / mol, greater than 100,000 g / mol, greater than 105,000 g / mol, greater than 110,000 g / mol, greater than 120,000 g / mol, greater than 130,000 g / mol, or greater than 140,000 g / mol.

[0054] The (meth)acrylic polymer may have a weight average molecular weight (MW) of 1,000,000 g / mol or less, 900,000 g / mol or less, 800,000 g / mol or less, 700,000 g / mol or less, 600,000 g / mol or less, 550,000 g / mol or less, 500,000 g / mol or less, or 450,000 g / mol or less. w ).

[0055] For example, according to a first preferred embodiment, the weight average molecular weight (Mw) of the (meth)acrylic polymer (PI) is preferably between 100,000 g / mol and 1,000,000 g / mol, preferably between 105,000 g / mol and 900,000 g / mol, more preferably between 110,000 g / mol and 800,000 g / mol, advantageously between 120,000 g / mol and 700,000 g / mol, more advantageously between 130,000 g / mol and 600,000 g / mol, and most advantageously between 140,000 g / mol and 500,000 g / mol.

[0056] In a second embodiment, the (meth)acrylic polymer has a weight average molecular weight M of less than 100,000 g / mol, less than 90,000 g / mol, less than 80,000 g / mol, less than 70,000 g / mol, less than 60,000 g / mol, less than 50,000 g / mol, or less than 40,000 g / mol. w .

[0057] In a second embodiment, the (meth)acrylic polymer may have a weight average molecular weight (MW) of 2000 g / mol or more, 3000 g / mol or more, 4000 g / mol or more, 5000 g / mol or more, 6000 g / mol or more, 6500 g / mol or more, 7000 g / mol or more, 10,000 g / mol or more, or 12,000 g / mol or more. w ).

[0058] The weight average molecular weight (M) of the (meth)acrylic polymer in the second embodiment w) may be between 2000 g / mol and 100,000 g / mol, between 3000 g / mol and 90,000 g / mol, between 4000 g / mol and 80,000 g / mol, between 5000 g / mol and 70,000 g / mol, between 6000 g / mol and 50,000 g / mol, or between 10,000 g / mol and 40,000 g / mol.

[0059] According to certain embodiments of the present invention, the (meth) acrylic polymer may include at least 50 wt%, at least 60 wt%, or at least 70 wt% of one or more monomers selected from C1 to C12 alkyl (meth) acrylic acid esters. For example, the (meth) acrylic polymer may include at least 50 wt%, at least 60 wt%, at least 70 wt%, or at least 80% of one or more monomers selected from C1 to C4 alkyl methacrylate monomers, C1 to C8 alkyl acrylate monomers, and mixtures thereof.

[0060] In certain embodiments, the glass transition temperature (Tg) of the (meth)acrylic polymer is 30° C. or higher, for example, between 30° C. and 150° C. The glass transition temperature of the (meth)acrylic polymer (PI) may be, for example, between 40° C. and 150° C., between 45° C. and 150° C., or between 50° C. and 150° C.

[0061] According to certain embodiments, the (meth)acrylic polymer is not cross-linked. According to other embodiments, the (meth)acrylic polymer is a thermoplastic polymer. The (meth)acrylic polymer may be a homopolymer or a copolymer, wherein "copolymer" refers to a polymer comprising two or more different monomers in polymerized form. The term "thermoplastic polymer" as used herein means a polymer that becomes liquid or becomes more liquid or less viscous when heated and can take on a new shape by applying heat and pressure. In certain embodiments, the (meth)acrylic polymer is not grafted onto any other polymer or polymers or at least a portion of the (meth)acrylic polymer is not grafted onto any other polymer or polymers.

[0062] In a first embodiment, the (meth) acrylic polymer comprises (in polymerized form) 50 wt % to 100 wt % of methyl methacrylate, 80 wt % to 100 wt % of methyl methacrylate or 80 wt % to 99.8 wt % of methyl methacrylate and 0.2 wt % to 20 wt % of C1 to C8 alkyl acrylate monomers. According to certain non-limiting embodiments, the C1 to C8 alkyl acrylate monomers may be selected from methyl acrylate, ethyl acrylate and butyl acrylate.

[0063] In a second embodiment, the (meth)acrylic polymer comprises (in polymerized form) between 0 wt% and 50 wt% of one or more functional monomers. For example, the (meth)acrylic polymer may comprise between 0 wt% and 30 wt%, between 1 wt% and 30 wt%, between 2 wt% and 30 wt%, between 3 wt% and 30 wt%, between 5 wt% and 30 wt%, or between 5 wt% and 30 wt% of functional monomers.

[0064] The functional monomer of the second preferred embodiment may be a (meth)acrylic monomer. The functional monomer may have formula (1) or (2):

[0065]

[0066]

[0067] In both formulas (1) and (2), R 1 Selected from H or CH 3 ; and in formula (1), Y is O, R 5 is H or an aliphatic or aromatic radical having at least one atom other than C or H; and in formula (2), Y is N and R 4 and R 3 Independently selected from H or aliphatic or aromatic radicals.

[0068] Preferably, the functional monomer is selected from glycidyl (meth)acrylate; (meth)acrylic acid; (meth)acrylamide such as, for example, dimethylacrylamide; 2-methoxyethyl (meth)acrylate; 2-aminoethyl (meth)acrylate (optionally quaternized); (meth)acrylate monomers containing phosphonate or phosphate groups; alkyl imidazolidinone (meth)acrylates and polyethylene glycol (meth)acrylates and combinations thereof. Preferably, the polyethylene glycol group of the polyethylene glycol (meth)acrylate has a number average molecular weight ranging from 400 g / mol to 10,000 g / mol.

[0069] According to certain embodiments of the present invention, the (meth)acrylic polymer does not contain any functional groups capable of participating in the curing / polymerization that occurs when the photocurable composition is cured. In such embodiments, the (meth)acrylic polymer may be considered non-reactive.

[0070] According to certain embodiments of the present invention, the (meth)acrylic polymer may be soluble in the organic polymeric substance (a mixture of monomers and oligomers present in the photocurable composition) at 25°C. That is, the organic polymeric substance acts as a solvent for the (meth)acrylic polymer. Therefore, the combination of the (meth)acrylic polymer, monomers and oligomers may be a homogeneous (single-phase) liquid at 25°C. "Soluble" means that the (meth)acrylic polymer dissolves when in contact with the polymeric organic substance within a certain time and a solution of the (meth)acrylic polymer in the polymeric organic substance is obtained. The solubility of the (meth)acrylic polymer in the polymeric organic substance can be easily tested by mixing the materials at 25°C under agitation and visually inspecting the mixture.

[0071] If present in the photocurable composition, the (meth)acrylic polymer can be included in any suitable amount, for example up to 80%, up to 70%, up to 60%, up to 50%, up to 40%, up to 30%, up to 20%, up to 10%, or up to 5% by weight, based on the total weight of the photocurable composition.

[0072] Polymeric organic matter

[0073] The photocurable composition used in the present invention includes polymeric organic substances. As used herein, the term "polymerization" means being able to participate in polymerization or curing reactions to form a polymeric structure. The polymeric organic substance can be monomeric and / or oligomeric in structure and can be characterized by comprising one, two, three or more polymeric functional groups per molecule. Suitable polymeric functional groups particularly include functional groups that can participate in chain growth and ring-opening polymerization mechanisms, such as olefinic and acetylenic unsaturated functional groups (such as (meth) acryloyl, vinyl, olefin and alkyne functional groups) and heterocyclic-functional groups (such as epoxide and oxetane functional groups). The polymeric functional groups polymerized via free radicals and / or cationic mechanisms are particularly preferred. The polymeric organic substance can include more than one type of polymeric functional groups. The molecular weight of suitable polymeric organic substances is not particularly limited and may be, for example, 120 to 50,000 g / mol or 150 to 25,000 g / mol (in the case where the polymeric organic substance is an oligomer, "molecular weight" refers to the number average molecular weight determined by gel permeation chromatography using polystyrene calibration standards). Combinations of different polymeric organic substances are used in the photocurable composition of the present invention. In particular, the photocurable composition includes at least one polymerized monomer and at least one polymerized oligomer.

[0074] According to certain embodiments, the total weight of oligomers in the photocurable composition is at least as much as the total weight of monomers. For example, the weight ratio of polymerized oligomers: polymerized monomers may be 50:50 to 90:10.

[0075] According to other embodiments, the total weight of monomers in the photocurable composition is at least as much as the total weight of oligomers. For example, the weight ratio of polymerized monomers:polymerized oligomers may be 50:50 to 90:10.

[0076] Preferably, the polymeric organic substance is selected such that when present in combination in the photocurable composition the combination is liquid at least in the temperature range between 0°C and 60°C.

[0077] Suitable illustrative types of polymeric organic materials that may be mentioned include, but are not limited to, epoxides (oxirane), oxetanes, oxolanes, cyclic acetals and other cyclic ethers, cyclic lactones, vinyl compounds (both aliphatic and aromatic), cyanoacrylates, (meth)acrylamides, and (meth)acrylates (which are particularly preferred). As used herein, the term "(meth)acrylate" refers to acrylate (-OC(=O)-CH=CH 2 ) and methacrylate (-OC(=O)-C(CH 3 )=CH 2 ) two functional groups.

[0078] The polymeric organic substance comprises at least one such moiety: it is capable of participating in a polymerization or curing reaction, whereupon a plurality of polymeric organic substance molecules become covalently bonded to each other to form a polymeric structure. Suitable reactive moieties include ethylenically unsaturated sites (i.e., carbon-carbon double bonds, C=C). Such ethylenically unsaturated sites may be provided, for example, by (meth)acryloyl, maleoyl, allyl, propenyl, and / or vinyl groups. As used herein, the term "(meth)acryloyl" is intended to include both methacryloyl and acryl groups as found in (meth)acrylates and (meth)acrylamides.

[0079] As mentioned previously, ethylenically unsaturated functional groups in polymeric organic materials suitable for use in photocurable compositions include groups containing at least one carbon-carbon double bond, particularly a carbon-carbon double bond capable of participating in a reaction (e.g., a free radical reaction) in which at least one carbon of the carbon-carbon double bond becomes covalently bonded to an atom, particularly a carbon atom, in a second molecule. Such a reaction may result in polymerization or curing, whereupon the organic material containing one or more ethylenically unsaturated functional groups becomes part of a polymeric matrix or polymer chain. The carbon-carbon double bond may, for example, be present as an α,β-unsaturated carbonyl moiety, such as an α,β-unsaturated ester moiety such as an acrylate functional group (H 2 C=CH-C(=O)O-) or methacrylate functional group (H 2 C=C(CH 3 )-C(=O)O-). A carbon-carbon double bond may also be present in a vinyl group -CH=CH 2or an allyl group -CH 2 -CH=CH 2 In the form of ethylenically unsaturated functional groups.

[0080] In certain embodiments, the photocurable composition used in the present invention is characterized by including at least one (meth)acrylate-functionalized organic material. (Meth)acrylate-functionalized organic materials can be described as organic materials carrying one or more (meth)acrylate functional groups per molecule. As used herein, the term "(meth)acrylate" refers to both acrylate and methacrylate functional groups. (Meth)acrylate-functionalized organic materials suitable for use in the present invention can generally be described as ethylenically unsaturated organic materials: they contain at least one carbon-carbon double bond in the alpha position relative to the ester group (compounds containing at least one α,β-unsaturated ester portion), in particular carbon-carbon double bonds that are capable of participating in free radical reactions, in particular reactions initiated by ultraviolet radiation or electron beam radiation. Such reactions can result in polymerization or curing, whereupon the (meth)acrylate-functionalized organic material becomes part of a polymeric matrix or polymer chain. In various embodiments of the present invention, the (meth)acrylate-functionalized organic material can contain one, two, three, four, five or more (meth)acrylate functional groups per molecule. Combinations of various (meth)acrylate-functional organic materials containing different numbers of (meth)acrylate groups may be used in the photocurable compositions of the present invention.

[0081] The photocurable composition used in the present invention may therefore comprise one or more (meth)acrylate-functionalized organic materials capable of undergoing free radical polymerization (curing) initiated by exposure to actinic radiation (e.g., ultraviolet light) or electron beam radiation. The (meth)acrylate-functionalized organic material may be an oligomer or a monomer, or preferably a combination of an oligomer and a monomer.

[0082] For example, any of the following types of (meth)acrylate-functionalized organic materials may be used in the photocurable compositions of the present invention, possibly or optionally in combination with one or more other types of polymeric organic materials as co-reactants: monomers, such as (meth)acrylates of aliphatic monoalcohols, alkoxylated (meth)acrylates of aliphatic monoalcohols, (meth)acrylates of aliphatic polyols, alkoxylated (meth)acrylates of aliphatic polyols, (meth)acrylates of aromatic ring-containing alcohols, and alkoxylated (meth)acrylates of aromatic ring-containing alcohols; and oligomers, such as epoxy (meth)acrylates, polyether (meth)acrylates, urethane (meth)acrylates, polyester (meth)acrylates (including amine- and sulfide-modified derivatives thereof); and combinations thereof.

[0083] According to one aspect of the present invention, the photocurable composition comprises at least one hydroxyalkyl (meth) acrylate, such as hydroxyethyl methacrylate and / or hydroxypropyl methacrylate. For example, the photocurable composition may comprise a total of 5 to 30 wt % of hydroxyalkyl (meth) acrylate, based on the total weight of polymerized organic matter in the photocurable composition. However, in other embodiments, the photocurable composition may comprise little or no hydroxyalkyl (meth) acrylate (e.g., less than 5 wt % or 0 wt %, based on the total weight of polymerized organic matter), because at least some hydroxyalkyl (meth) acrylates have sensitizing properties.

[0084] According to another aspect of the invention, the photocurable composition comprises at least one cycloalkyl (meth)acrylate, in particular isobornyl (meth)acrylate. For example, the photocurable composition may comprise 1 to 25 or 5 to 15 weight percent of a cycloalkyl (meth)acrylate, such as isobornyl methacrylate, based on the total weight of polymerized organic matter in the photocurable composition. Cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and cyclic trimethylolpropane formal (meth)acrylate represent other types of cycloalkyl (meth)acrylates that can be used in the present invention.

[0085] According to another aspect of the present invention, the photocurable composition comprises at least one ethylene glycol- or poly(ethylene glycol)-based (meth)acrylate, such as poly(ethylene glycol) di(meth)acrylate. Such materials can be described as (meth)acrylates of ethylene glycol and poly(ethylene glycol), wherein the polyethylene glycol can contain two or more oxyethylene units derived from ethylene oxide per molecule. In certain embodiments, the material includes an ethylene glycol segment or a polyethylene glycol segment having a number average molecular weight of about 100 g / mol to about 1000 g / mol. Such a segment can correspond to the structural formula –(CH 2 CH 2 O) n-, wherein n is on average 2 to 25. For example, the photocurable composition may contain 1 to 80 or 5 to 60 weight percent of poly(ethylene glycol) di(meth)acrylate, based on the total weight of polymerized organic matter in the photocurable composition. Ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, PEG-9 di(meth)acrylate (containing an average of about 9 oxyethylene units per molecule), PEG200 di(meth)acrylate (containing a polyethylene glycol segment having a number average molecular weight of about 200 g / mol), and PEG600 di(meth)acrylate (containing a polyethylene glycol segment having a number average molecular weight of about 600 g / mol) represent other types of ethylene glycol- or poly(ethylene glycol)-based (meth)acrylates that can be used in the present invention. An advantage of using such ethylene glycol- or poly(ethylene glycol)-based (meth)acrylates in photocurable compositions is that, unlike certain other types of (meth)acrylate-functional monomers, such materials are generally hypoallergenic to nonallergenic.

[0086] In yet another aspect of the invention, the photocurable composition comprises at least one (meth)acrylate functionalized monomer containing three or more (meth)acrylate functional groups per molecule, in particular (meth)acrylates of polyols containing three or more hydroxyl groups per molecule and alkoxylated derivatives thereof, such as glycerol, trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, triethylolpropane and ethoxylated and / or propoxylated derivatives thereof, wherein the polyol is reacted with 1 to 10 moles of ethylene oxide and / or propylene oxide per mole of polyol. For example, the photocurable composition may comprise a total of 0.1 to 20 or 0.5 to 10 wt. % of such (meth)acrylate functionalized monomers containing three or more (meth)acrylate functional groups per molecule, such as trimethylolpropane trimethacrylate.

[0087] Suitable (meth)acrylate functionalized oligomers include, for example, polyester (meth)acrylates, epoxy (meth)acrylates, polyether (meth)acrylates, urethane (meth)acrylates (sometimes also referred to as polyurethane (meth)acrylates or urethane (meth)acrylate oligomers), and combinations thereof, as well as amine-modified and sulfide-modified variants thereof. Certain of these (meth)acrylate functionalized oligomers can act as toughening agents in cured articles obtained by curing the photocurable composition, i.e., their inclusion helps increase the flexibility of the cured article prepared therefrom.

[0088] Exemplary polyester (meth) acrylates include the reaction products of acrylic acid or methacrylic acid or mixtures thereof with hydroxyl group-terminated polyester polyols. The reaction process may be carried out to such an extent that a significant concentration of residual hydroxyl groups remain in the polyester (meth) acrylate, or may be carried out to such an extent that all or substantially all of the hydroxyl groups of the polyester polyol have been (meth) acrylated. The polyester polyol may be made by polycondensation of a polyhydroxyl functional component (particularly a diol) and a polycarboxylic acid functional compound (particularly a dicarboxylic acid and anhydride). To prepare the polyester (meth) acrylate, the hydroxyl groups of the polyester polyol are then partially or completely esterified by reaction with (meth) acrylic acid, (meth) acryloyl chloride, (meth) acrylic anhydride, and the like. The polyester (meth) acrylate may also be synthesized by reacting a hydroxyl-containing (meth) acrylate, such as a hydroxyalkyl (meth) acrylate (e.g., hydroxyethyl acrylate) with a polycarboxylic acid. The polyhydroxyl functional and polycarboxylic acid functional components may each have a linear, branched, cyclic aliphatic or aromatic structure and may be used alone or as a mixture.

[0089] Examples of suitable epoxy (meth)acrylates include the reaction products of acrylic acid or methacrylic acid, or mixtures thereof, with glycidyl ethers or esters.

[0090] Exemplary polyether (meth) acrylate oligomers include, but are not limited to, condensation products of acrylic acid or methacrylic acid or mixtures thereof with polyether alcohols as polyether polyols. Suitable polyether alcohols may be linear or branched substances containing ether bonds and terminal hydroxyl groups. Polyether alcohols may be prepared by ring-opening polymerization of epoxides and other oxygen-containing heterocyclic compounds (e.g., ethylene oxide, 1,2-propylene oxide, butylene oxide, tetrahydrofuran, and combinations thereof) with starter molecules. Suitable starter molecules include water, hydroxyl-functional materials, polyester polyols, and amines. Polyether alcohols may also be obtained by condensation of glycols such as ethylene glycol.

[0091] Urethane (meth)acrylates (sometimes also referred to as "polyurethane (meth)acrylates" or "urethane (meth)acrylate oligomers") that can be used in the photocurable composition of the present invention include urethanes based on aliphatic and / or aromatic polyester polyols, polyether polyols and polycarbonate polyols, as well as aliphatic and / or aromatic polyester diisocyanates and polyether diisocyanates blocked with (meth)acrylate end-groups.

[0092] In various embodiments, urethane (meth) acrylates can be prepared by reacting aliphatic and / or aromatic polyisocyanates (e.g., diisocyanates, triisocyanates) with OH-group terminated polyester polyols (including aromatic, aliphatic and mixed aliphatic / aromatic polyester polyols), polyether polyols, polycarbonate polyols, polycaprolactone polyols, polydimethylsiloxane polyols, or polybutadiene polyols, or combinations thereof, to form isocyanate-functionalized oligomers, which are then reacted with hydroxyl-functionalized (meth) acrylates, such as hydroxyethyl (meth) acrylate or hydroxypropyl (meth) acrylate, to provide terminal (meth) acrylate groups. For example, urethane (meth) acrylates can contain two, three, four, or more (meth) acrylate functional groups per molecule. Other addition orders can also be used in practice to prepare polyurethane (meth) acrylates, as known in the art. For example, a hydroxyl-functional (meth) acrylate may first be reacted with a polyisocyanate to obtain an isocyanate-functional (meth) acrylate, which may then be reacted with an OH-group terminated polyester polyol, polyether polyol, polycarbonate polyol, polycaprolactone polyol, polydimethylsiloxane polyol, polybutadiene polyol, or a combination thereof. In yet another embodiment, a polyisocyanate may first be reacted with a polyol (including any of the aforementioned types of polyols) to obtain an isocyanate-functional polyol, which may then be reacted with a hydroxyl-functional (meth) acrylate to produce a polyurethane (meth) acrylate. Alternatively, all components may be combined and reacted simultaneously.

[0093] Any of the foregoing types of oligomers may be modified with amines or sulfides (e.g., thiols) following procedures known in the art. Such amine- and sulfide-modified oligomers may be prepared, for example, by reacting a relatively small portion (e.g., 2-15%) of the (meth)acrylate functional groups present in the base oligomer with an amine (e.g., a secondary amine) or a sulfide (e.g., a thiol), wherein the modifying compound is added to the carbon-carbon double bond of the (meth)acrylate in a Michael addition reaction.

[0094] Illustrative examples of suitable monomeric (meth)acrylate-functionalized organic materials include (meth)acrylated mono- and polyols (polyols) and (meth)acrylated alkoxylated mono- and polyols. The mono- and polyols may be aliphatic (including one or more cycloaliphatic rings) or may contain one or more aromatic rings (such as in the case of phenol or bisphenol A). "Alkoxylated" means that, prior to esterification for the introduction of one or more (meth)acrylate functional groups, the base mono- or polyol has been reacted with one or more epoxides, such as ethylene oxide and / or propylene oxide, to remove one or more ether moieties (e.g., -CH 2 CH 2-O-) is introduced into one or more hydroxyl groups of a monoalcohol or a polyol. For example, the amount of epoxide reacted with a monoalcohol or a polyol may be about 1 to about 30 moles of epoxide per mole of monoalcohol or polyol. Examples of suitable monoalcohols include, but are not limited to, straight chain, branched, and cyclic C1-C54 monoalcohols (may be primary, secondary, or tertiary alcohols). For example, a monoalcohol may be a C1-C7 aliphatic monoalcohol. In other embodiments, a monoalcohol may be a C8-C24 aliphatic monoalcohol (e.g., lauryl alcohol, stearyl alcohol). Examples of suitable polyols include organic compounds such as glycols (glycols) such as ethylene glycol, 1,2- or 1,3-propylene glycol, or 1,2-, 1,3- or 1,4-butanediol, neopentyl glycol, trimethylolpropane, triethylolpropane, pentaerythritol, glycerol, etc., containing two, three, four or more hydroxyl groups per molecule.

[0095] Representative but non-limiting examples of suitable monomeric (meth)acrylate-functionalized compounds include: 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, longer chain aliphatic di(meth)acrylates (e.g., generally corresponding to formula H 2 C=CRC(=O)-O-(CH 2 ) m -OC(=O)CR'=CH 2those wherein R and R' are independently H or methyl and m is an integer from 8 to 24), alkoxylated (e.g. ethoxylated, propoxylated) hexanediol di(meth)acrylate, alkoxylated (e.g. ethoxylated, propoxylated) neopentyl glycol di(meth)acrylate, dodecyl di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, alkoxylated (e.g. ethoxylated, propoxylated) bisphenol A di(meth)acrylate, ethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tricyclodecane dimethanol diacrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate alcohol di(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, alkoxylated (e.g. ethoxylated, propoxylated) pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, pentaerythritol tetra(meth)acrylate, alkoxylated (e.g. ethoxylated, propoxylated) trimethylolpropane tri(meth)acrylate, alkoxylated (e.g. ethoxylated, propoxylated) glycerol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tri(2-hydroxyethyl)isocyanurate tri(meth)acrylate, 2(2-ethoxyethoxy)ethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, alkoxylated lauryl (meth)acrylate, alkoxylated phenol (meth)acrylate, alkoxylated tetrahydrofurfuryl (meth)acrylate, caprolactone (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, dicyclopentadienyl (meth)acrylate, diethylene glycol methyl ether (meth)acrylate, alkoxylated (e.g. ethoxylated, propoxylated) nonylphenol (meth)acrylate, isobornyl (meth)acrylate, isodecyl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, octyldecyl (meth)acrylate (also known as stearyl (meth)acrylate), tetrahydrofurfuryl (meth)acrylate, tridecyl (meth)acrylate, triethylene glycol ethyl ether (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, di(meth)acrylate (meth)acrylate, dicyclopentadienyl (meth)acrylate, phenoxyethanol (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tetradecyl (meth)acrylate, cetyl (meth)acrylate, hexadecyl (meth)acrylate, behenyl (meth)acrylate, diethylene glycol ethyl ether (meth)acrylate, diethylene glycol butyl ether (meth)acrylate, triethylene glycol methyl ether (meth)acrylate, dodecanediol di(meth)acrylate, dipentaerythritol penta / hexa(meth)acrylate, pentaerythritol tetra(meth)acrylate, alkoxylated (e.g., ethoxylated, propoxylated) pentaerythritol tetra(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, alkoxylated (e.g., ethoxylated, propoxylated) glycerol tri(meth)acrylate and tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate and combinations thereof.

[0096] Other types of polymeric organic materials containing ethylenically unsaturated functional groups suitable for use in the photocurable compositions of the present invention include cyanoacrylates, vinyl esters, 1,1-diester-1-olefins, 1,1-diketone-1-olefins, 1-ester-1-keto-1-olefins, and itaconates, including methylene malonate and / or methylene β-diketone.

[0097] The amount of the (meth)acrylate functionalized oligomer may vary based on the viscosity of the oligomer or the desired tensile properties of the photocurable composition after curing. For example, the photocurable composition may include 1 to 80 or 5 to 60 weight percent of the (meth)acrylate functionalized oligomer, based on the total weight of polymerized organic matter in the photocurable composition. A suitable (meth)acrylate functionalized oligomer may be trimethylhexyl diaminoethane (UDMA).

[0098] According to a particularly preferred embodiment of the present invention, the polymeric organic substances constituting components a) and b) of the photocurable composition are selected to be compatible with the core / shell copolymer also present in the photocurable composition. As used herein, the term "compatible" means that when the components of the photocurable composition are combined, the photocurable composition does not gel or the viscosity does not increase to an unacceptable level (that is, the photocurable composition is still workable, i.e., can be applied and molded according to its intended end-use application).

[0099] Photoinitiator

[0100] The photocurable compositions described herein include at least one photoinitiator and can be cured with radiation energy (actinic radiation). A photoinitiator can be considered to be any type of substance that, when exposed to radiation (e.g., actinic radiation), forms a species that initiates the reaction and curing of polymeric organic substances, such as monomeric polymeric organic substances and oligomeric polymeric organic substances, present in the photocurable composition. Suitable photoinitiators include both free radical photoinitiators and cationic photoinitiators and combinations thereof. The photoinitiator should be selected so that it is easily activated by photons of a wavelength associated with the actinic radiation intended to be used to cure the photocurable composition. Preferably, the photoinitiator or combination of photoinitiators should be active at a wavelength of ultraviolet light emitted by a lamp that is commonly or habitually seen in a nail salon.

[0101] Free radical polymerization initiators are substances that form free radicals when irradiated.

[0102] The use of free radical photoinitiators is particularly preferred when the photocurable composition comprises a polymeric organic substance containing polymerizable (reactive) ethylenically unsaturated functional groups such as (meth)acrylate functional groups. Non-limiting types of free radical photoinitiators suitable for use in the photocurable compositions of the present invention include, for example, benzoin, benzoin ether, acetophenone, benzyl, benzyl ketal, anthraquinone, phosphine oxide, α-hydroxy ketone, phenyl glyoxylate, α-aminoketone, benzophenone, thioxanthone, xanthone, acridine derivatives, phenazine (phenazene) derivatives, quinoxaline derivatives and triazine compounds.Examples of particularly suitable free radical photoinitiators include, but are not limited to, 2-methylanthraquinone, 2-ethylanthraquinone, 2-chloroanthraquinone, 2-benzylanthraquinone, 2-tert-butylanthraquinone, 1,2-benzo-9,10-anthraquinone, benzyl, benzoin, benzoin ether, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, α-methylbenzoin, α-phenylbenzoin, Michler's ketone, ketone), acetophenones such as 2,2-dialkoxybenzophenone and 1-hydroxyphenyl ketone, benzophenone, 4,4'-bis-(diethylamino)benzophenone, acetophenone, 2,2-diethoxyacetophenone, diethoxyacetophenone, 2-isopropylthioxanthone, thioxanthone, diethylthioxanthone, 1,5-acetylnaphthalene, ethyl p-dimethylaminobenzoate, benzyl ketone, α-hydroxyketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzyl dimethyl ketal, 2,2-dimethoxy-1,2-diphenylethanone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylmercapto)phenyl]-2-morpholinopropyl 1-Hydroxy-2-methyl-1-phenyl-propanone, oligomeric α-hydroxy ketone, benzoylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl-4-dimethylaminobenzoate, ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate, anisole, anthraquinone, anthraquinone-2-sulfonic acid, sodium salt monohydrate, (benzene)tricarbonylchromium, benzil, benzoin isobutyl ether, 50 / 50 blend of benzophenone / 1-hydroxycyclohexylphenylketone, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4-benzoylbiphenyl, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyryl benzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, camphorquinone, 2-chlorothioxanthen-9-one, dibenzosuberenone, 4,4'-dihydroxybenzophenone, 2,2-dimethoxy-2-phenylacetophenone, 4-(dimethylamino)benzophenone, 4,4'-dimethylbenzil, 2,5-dimethylbenzophenone, 3,4-dimethylbenzophenone, a 50 / 50 blend of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide / 2-hydroxy-2-methylpropiophenone, 4'-ethoxyacetophenone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, phenyl Bis(2,4,6-trimethylbenzoyl)phosphine oxide, ferrocene, 3'-hydroxyacetophenone, 4'-hydroxyacetophenone, 3-hydroxybenzophenone, 4-hydroxybenzophenone, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methylpropiophenone, 2-methylbenzophenone, 3-methylbenzophenone, methylbenzoylformate, 2-methyl-4'-(methylmercapto)-2-morpholinopropiophenone, phenanthrenequinone, 4'-phenoxyacetophenone, (cumene)cyclopentadienyliron(ii) hexafluorophosphate, 9,10-diethoxy and 9,10-dibutoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, thioxanthen-9-one, and combinations thereof.

[0103] Suitable cationic photoinitiators include any type of photoinitiator that, when exposed to radiation, such as actinic radiation, forms a cation (e.g., Bronsted photoinitiator) that initiates a reaction of monomeric and, if present, oligomeric polymeric organic species in the photocurable composition. or Lewis acid). For example, a cationic photoinitiator may include a cationic portion and an anionic portion. The cationic portion of the photoinitiator molecule may be responsible for the absorption of UV radiation while the anionic portion of the molecule becomes a strong acid after UV absorption. Suitable cationic photoinitiators include, for example, onium salts with anions that are weakly nucleophilic, such as halogen onium salts, iodonium salts (e.g., diaryl iodonium salts such as bis(4-tert-butylphenyl)iodonium perfluoro-1-butanesulfonate) or sulfonium salts (e.g., triaryl sulfonium salts such as triaryl sulfonium hexafluoroantimonate); sulfonium oxide salts; and diazonium salts. Metallocene salts are other types of suitable cationic photoinitiators.

[0104] The amount of the photoinitiator may be appropriately changed depending on the selected photoinitiator, the amount and type of polymeric organic substances (monomer type and oligomer type) present in the photocurable composition, the radiation source and radiation conditions used, and other factors. However, typically, the amount of the photoinitiator may be 0.05% to 5%, preferably 0.1% to 2% by weight, based on the total weight of the photocurable composition.

[0105] Other additives / components

[0106] Instead of or in addition to the above ingredients, the photocurable composition of the present invention may optionally contain one or more additives. Such additives include, but are not limited to, antioxidants / light stabilizers, light blockers / absorbers, inhibitors, foam inhibitors, flow or leveling agents, colorants, pigments, dispersants (wetting agents, surfactants), slip additives, fillers, chain transfer agents, thixotropic agents, rheology modifiers, matting agents, impact modifiers (except for the core / shell copolymers and oligomeric polymeric organic substances already mentioned), waxes or other various additives, including any additives conventionally used in the field of nail coatings.

[0107] To prevent premature gelation or curing of the photocurable composition, especially in the presence of oxygen or other oxidants, one or more antioxidants may be included in the photocurable composition. Any antioxidant known in the art may be used, including, for example, phenol-based antioxidants, phosphorus-based antioxidants, quinone-type antioxidants, and combinations thereof.

[0108] Examples of suitable phenol-based antioxidants may include hindered phenol-type antioxidants such as hexamethylenebis[(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid amide], 4,4′-mercaptobis(6-tert-butyl-m-cresol), 2,2′-methylenebis(4-methyl-5-tert-butylphenol), 2,2′-methylenebis(4-ethyl-6-tert-butylphenol), bis[3,3-bis(4-hydroxy-3-tert-butylphenyl)butanoic acid] glycol ester, 2,2′-ethylenebis(4,6-di-tert-butylphenol), 2,2′-ethylenebis(4-sec-butyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, bis[2-tert-butyl-4-methyl-6-(2-hydroxy-3-tert-butyl-5-methylbenzyl)phenyl]terephthalate, 1,3, 5-Tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, 2-tert-butyl-4-methyl-6-(2-acryloyloxy-3-tert-butyl-5- The antioxidants include butylated hydroxytoluene (BHT), butylated hydroxytoluene (BHT), 3,9-bis[1,1-dimethyl-2-{(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, triethylene glycol bis[(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], and n-octadecyl-3-(4′-hydroxy-3′,5′-di-tert-butylphenyl)butane. Butylated hydroxytoluene (BHT) is an example of a preferred antioxidant.

[0109] Examples of suitable phosphorus-based antioxidants may include phosphites (or salts), phosphonites (or salts), and the like, such as trisnonylphenyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris[2-tert-butyl-4-(3-tert-butyl-4-hydroxy-5-methylphenylmercapto)-5-methylphenyl] phosphite, tridecyl phosphite, octyl diphenyl phosphite, di(decyl)monophenyl phosphite, di(tridecyl)pentaerythritol diphosphite, distearylpentaerythritol diphosphite, di(nonylphenyl)pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tri-tert-butyl)pentaerythritol diphosphite diphosphite, tetrakis(tridecyl)-4,4′-n-butylenebis(2-tert-butyl-5-methylphenol)diphosphite, hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane triphosphite, tetrakis(2,4-di-tert-butylphenyl)biphenylene diphosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-ether, 2,2′-methylenebis(4-methyl-6-tert-butylphenyl)-2-ethylhexylphosphite and 4-[3-[(2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphaphenanthrene)-6-yloxy]propyl]-2-methyl-6-tert-butylphenol.

[0110] Quinone type antioxidants such as monomethyl ether of hydroquinone (MEHQ) may also be used. Phenothiazine (RTZ) and vitamin E are examples of other suitable antioxidants that may be used in the present invention.

[0111] Typically, one or more antioxidants may be included in the photocurable composition in a total amount of up to 4 wt %, such as 0.05 to 2 wt %, based on the weight of the photocurable composition.

[0112] Advantageously, the photocurable composition used in the present invention can be formulated to be solvent-free, i.e., free of any non-reactive volatile materials (materials having a boiling point at atmospheric pressure of 150° C. or less). For example, the photocurable composition may contain little or no non-reactive solvent, e.g., less than 10% or less than 5% or less than 1% or even 0% of non-reactive solvent, based on the total weight of the photocurable composition. In the context of the present invention, "non-reactive" refers to materials that do not react when exposed to actinic radiation, i.e., non-polymeric materials. Such solvent-free or low-solvent compositions can be formulated using various components (including, for example, low-viscosity reactive diluents (e.g., monomeric polymeric organic materials)) that are selected to make the viscosity of the photocurable composition low enough to allow the photocurable composition to be easily applied to a substrate surface, such as a subject's nail surface, at a suitable application temperature, even in the absence of a solvent.

[0113] However, in other embodiments, the photocurable composition used contains a certain amount of non-reactive solvent, particularly a certain amount of volatile non-reactive solvent (having a boiling point of no more than 150° C. at atmospheric pressure). As an example, if the photocurable composition is to be formulated as a relatively low viscosity topcoat, basecoat, colorcoat or nail polish, one or more non-reactive solvents may be included. For example, the photocurable composition may include at least 0.5, at least 1, at least 5 or at least 10% by weight of non-reactive solvent, based on the total weight of the photocurable composition. The photocurable composition may include no more than 50, no more than 25 or no more than 15% by weight of non-reactive solvent, based on the total weight of the photocurable composition. The amount of non-reactive solvent can be adjusted to achieve the target viscosity value, because the non-reactive solvent will generally reduce the viscosity of the photocurable composition. Two or more non-reactive solvents can be used in combination. Suitable non-reactive solvents include esters (e.g., ethyl acetate and butyl acetate), ethers, ketones, glycol ethers, alcohols, hydrocarbons and combinations thereof.

[0114] In certain embodiments of the present invention, the photocurable composition is a liquid at 25° C. For example, the photocurable composition may be a flowable and / or self-leveling liquid at 25° C. However, in other embodiments, the photocurable composition may be a gel at 25° C. Such a gel may be non-flowable.

[0115] The viscosity of the photocurable composition at 25°C can vary widely depending on the intended end-use application, as discussed in more detail below. For example, the viscosity of the photocurable composition at 25°C can range from 100 cp to 5,000,000 cp.

[0116] In various embodiments of the present invention (e.g., where the photocurable composition is intended to be used as a UV gel nail polish, basecoat, colorcoat, or topcoat), the photocurable composition described herein is formulated to have a relatively low viscosity at ambient or room temperature. For example, the viscosity of the photocurable composition can be selected or adjusted by varying the components present and their relative ratios to provide a viscosity at 25°C of no more than 100,000 cp, no more than 50,000 cp, no more than 25,000 cp, or no more than 10,000 cp as measured by a Brookfield DV3T cone and plate viscometer, wherein the measurement is performed on a 0.5 mL sample at 25°C using a CPE-52Z cone (spindle). The viscosity at 25°C may be, for example, at least 100 cp or at least 500 cp.

[0117] However, in other embodiments of the present invention, the photocurable compositions described herein are formulated to have a relatively high viscosity at ambient or room temperature. Such high viscosity photocurable compositions may be of interest in the case where they are intended to be applied to the surface of the nail and then shaped (i.e., builder gel, styling gel, or nail extensions). For example, the viscosity of the photocurable composition may be selected or adjusted by changing the components present and their relative ratios to provide a viscosity at 25°C of at least 200,000cp, at least 300,000cp, or at least 400,000cp measured by a Brookfield DV3T cone and plate viscometer, wherein the measurement is performed on a 0.5mL sample at 25°C using a CPE-52Z cone. At the same time, the viscosity should not be so high that the photocurable composition becomes difficult to apply and / or shape on the surface of the nail. The viscosity at 25°C may be, for example, not greater than 5,000,000cp or not greater than 4,000,000cp.

[0118] The viscosity and other rheological properties of the photocurable composition can be selected so that when a portion of the photocurable composition is applied to the nail surface, it does not move easily until it is pushed into the desired shape (molding) by a manicurist tool such as a brush, a pusher and / or a spatula. Pushing and molding the photocurable composition into the desired shape can be done neatly or it can be done with the assistance of a low-viscosity liquid (e.g., a non-reactive solvent and / or a reactive diluent such as a (meth)acrylate-functionalized monomer) that at least partially reduces the viscosity of the photocurable composition. According to a favorable embodiment of the present invention, when the photocurable composition is in neat form or mixed with such a liquid (in a limited amount), the photocurable composition remains firm (but plastic) and does not flow. An operator, such as a nail technician, can optionally control the viscosity by applying such a suitable liquid (which can be done only in selected areas of the photocurable composition portion on the nail surface) until the photocurable composition is cured by exposure to actinic radiation (e.g., UV light).

[0119] Although in one embodiment only a single photocurable composition part is applied to an individual nail prior to the photocuring step, multiple photocurable composition parts may be applied in other embodiments of the invention. For example, a first photocurable composition part may be applied and shaped, followed by a second photocurable composition part (which may be a different color or be differently pigmented than the first photocurable composition, or which may otherwise differ in composition), wherein the second photocurable composition part is shaped prior to photocuring both parts to provide a cured nail coating.

[0120] Formulation of photocurable composition

[0121] The relative weight proportions of component (a) (at least one (meth)acrylate functionalized monomer), component (b) (at least one (meth)acrylate functionalized oligomer), component (c) (at least one particle of a core / shell copolymer), and component (d) (at least one photoinitiator) are not believed to be particularly critical and may be varied as desired based on the specific components selected and the properties sought in the photocurable composition and the cured article obtained therefrom. For example, the photocurable composition in certain embodiments may include 5 to 45 wt% component (a), 5 to 60 wt% component (b), 10 to 60 wt% component (c), and 0.1 to 10 wt% component (d), wherein the weights of (a), (b), (c), and (d) together equal 100% (meaning that the foregoing wt% ranges for each of (a), (b), (c), and (d) are based on the summed weight of those components, not the total weight of the photocurable composition, which may include components other than (a), (b), (c), and (d)).

[0122] According to a preferred embodiment, the components of the photocurable composition are selected such that the photocurable composition is liquid at least in the temperature range between 0° C. and 60° C. As used in this context, the term "liquid" does not exclude the possibility that a certain part of the photocurable composition (in particular, the core / shell copolymer) may be present as small well-dispersed particles in an otherwise liquid matrix.

[0123] Generally speaking, the photocurable composition according to the invention can be prepared by combining the individual components. If the (meth) acrylic polymer is a component of the photocurable composition, the core / shell copolymer and the (meth) acrylic polymer can be supplied to the photocurable composition separately or together as part of a polymer composition obtained, for example, by a core / shell copolymerization process, in which the (meth) acrylic polymer is prepared as one of the stages. The photocurable composition can also be manufactured using a masterbatch approach, wherein a masterbatch comprising a core / shell copolymer, a (meth) acrylic polymer and a relatively small amount of polymeric organic substance is first prepared, which is then combined with further polymeric organic substance and possible other components (e.g. photoinitiator) to produce the final photocurable composition to be used in the manufacture of a cured nail coating.

[0124] Use of photocurable composition in forming nail coating

[0125] The photocurable composition used in the present invention is photocured (i.e., cured by exposure to actinic radiation such as light, particularly visible or UV light). However, such photocuring is not performed until after the photocurable composition is applied to the nail surface and, in certain embodiments, molded into the desired configuration. For example, a method of forming a cosmetic nail coating comprises the steps of placing the above-described photocurable composition on a subject's nail, optionally molding the photocurable composition, and exposing the photocurable composition to UV light.

[0126] The placement of a portion (e.g., a bead) of the photocurable composition can be performed by an operator (who may be a technician or the individual whose nails are to be coated) directly by squeezing it from a tube container or pushing it from a syringe with a piston onto the nail or application tool. Alternatively, the application of the photocurable composition can be accomplished with the help of an application tool such as an acrylic or gel brush, a pusher and / or a spatula or other such tools conventionally used for applying nail coating products.

[0127] After placing the photopolymerizable composition bead on the nail, the operator can manipulate the photocurable composition to move it to the desired position and form it into the desired shape with or without the use of a nail mold. A nail mold can also be used, wherein a portion of the photocurable composition (preferably in the form of a high viscosity liquid or gel) is applied to a nail surface mold, the applied photocurable composition portion is molded in the nail mold, the nail mold containing the molded photocurable composition portion is applied to the subject's nail (the surface with the molded photocurable composition portion is contacted with the nail surface), the photocurable composition is cured by exposure to actinic radiation to provide a cured nail coating, and then the nail mold is separated from the cured nail coating.

[0128] After the photocurable composition is applied to the nail surface and optionally molded or formed, the nail with the photocurable composition arranged thereon is exposed to actinic radiation such as UV light under conditions that effectively cure the photocurable composition. Suitable UV light sources can be UV lamps, such as UV lamps commonly used in nail salons. Such UV lamps can be operated at any wavelength required for curing the photocurable composition, such as at a wavelength between 320nm and 420nm. The exposure time should be long enough to achieve the curing of the photocurable composition. For example, this can be 5 seconds to 6 minutes.

[0129] The term "UV lamp" is intended to be interpreted broadly. It refers to any electromagnetic radiation source that emits light in the range of 320nm to 420nm with an intensity sufficient to cure the photocurable composition used in the present invention. The term "UV lamp" includes traditional UV lamps including fluorescent lamps such as compact fluorescent bulbs, which emit UV light in the above range. The term "UV lamp" also refers to newer light or UV radiation sources such as light emitting diode lamps (often referred to as "LED lamps"), which emit electromagnetic radiation including UV light in the range of 320nm to 420nm with an intensity sufficient to cure the photocurable composition. The term "UV lamp" also refers to any other type of light source including UV light in the range of 320nm to 420nm with an intensity sufficient to cure the photocurable composition.

[0130] After the curing step, the cured nail coating may be subjected to one or more further processing steps, such as trimming, buffing, polishing, buffing, decorating, etc. A multilayer photocured coating may also be formed on the nail surface, wherein a first layer of a photocurable composition is applied to the nail surface, optionally shaped and cured, and thereafter at least one further (additional) layer of a photocurable composition is applied onto the cured first layer, optionally shaped and then also cured.

[0131] Packaged article comprising a photocurable composition

[0132] The above-mentioned photocurable composition can be packaged (packaged, packed, packaged) in a suitable container and stored and / or transported, and then the photocurable composition is used to form a cured nail coating. The packaged product may therefore include a container and a photocurable composition arranged in the container, wherein the packaged product has a dispensing member capable of dispensing the photocurable composition from the container. Suitable types of containers include tubes, bottles (including cylinders or cans) and syringes (equipped with pistons). The container may be rigid or flexible; for example, the container may be a flexible tube or bottle that allows the user to squeeze the container so as to dispense the photocurable composition through the orifice in the container. The container may be equipped with a detachable closure device such as a threaded or compressed cover or flap that allows the contents of the container to be closed to prevent or counteract accidental discharge when not in use. Such a detachable closure device may include an application tool such as a brush. It is generally preferred that the container is opaque to enhance the storage stability of the photocurable composition contained therein. The dispensing member may be, for example, a brush, a foam applicator, a cotton core, a nozzle, a roller, a needle or an orifice (hole) and the like. As an example, the dispensing member can be an orifice configured to deliver a desired portion of the photocurable composition, such as a bead, directly onto the nail surface or to an applicator (application device) such as a brush, pusher or spatula (which is then used to transfer the portion of the photocurable composition onto the nail surface).

[0133] The present invention also contemplates a kit comprising: a packaged product including a container and a photocurable composition disposed in the container, at least one application device, and instructions for dispensing, applying and curing the photocurable composition to provide a nail coating. The packaged product may have the aforementioned dispensing member. The instructions may be provided in the form of an instruction sheet and / or printed on a package containing the kit components.

[0134] Aspects of the Invention

[0135] Certain illustrative, non-limiting inventive aspects can be summarized as follows:

[0136] Aspect 1: A coating on a nail, wherein the coating is a photocured product of a photocurable composition, wherein the photocurable composition comprises:

[0137] a). at least one (meth)acrylate functionalized monomer;

[0138] b). at least one (meth)acrylate functionalized oligomer;

[0139] c) particles of at least one core / shell copolymer; and

[0140] d). At least one photoinitiator.

[0141] Aspect 2: The coating of Aspect 1, wherein the core / shell copolymer comprises a core comprising an elastomeric polymer having a glass transition temperature of less than 0°C and at least one shell comprising a non-elastomeric polymer having a glass transition temperature of at least 30°C.

[0142] Aspect 3: The coating of Aspect 1 or 2, wherein particles of at least one core / shell copolymer are suspended in a liquid matrix comprising a) and b).

[0143] Aspect 4: The coating of any one of Aspects 1 to 3, wherein the particles of at least one core / shell copolymer have an average particle size of 25 to 900 nm.

[0144] Aspect 5: The coating of any one of Aspects 1 to 4, wherein the photocurable composition comprises a total of 0 to 20 wt % of at least one non-reactive solvent, based on the weight of the photocurable composition.

[0145] Aspect 6: The coating of any of Aspects 1 to 5, wherein the photocurable composition comprises 1 to 60%, 5 to 55%, or 10 to 50% by weight of particles of at least one core / shell copolymer, based on the total weight of the photocurable composition.

[0146] Aspect 7: The coating of any one of Aspects 1 to 6, wherein at least one shell comprises in polymerized form at least one monomer selected from alkyl methacrylates having a C1-C12 alkyl chain, C6-C12 vinyl aromatic organic compounds, acrylonitrile, and combinations thereof, wherein the shell is optionally cross-linked.

[0147] Aspect 8: The coating of any of Aspects 1 to 7, wherein at least one shell comprises methyl methacrylate in polymerized form, wherein the shell is optionally cross-linked.

[0148] Aspect 9: The coating of any one of Aspects 1 to 8, wherein the core comprises in polymerized form at least one monomer selected from C4-C12 conjugated dienes and C1-C12 alkyl acrylates.

[0149] Aspect 10: The coating of any one of Aspects 1 to 9, wherein the core / shell copolymer is selected from:

[0150] a) a core / shell copolymer comprising a core and a shell, the core comprising butyl acrylate in polymerized form and the shell comprising methyl methacrylate in polymerized form; and

[0151] b) A core / shell copolymer comprising a core comprising styrene and butadiene in copolymerized form and a shell comprising methyl methacrylate in polymerized form.

[0152] Aspect 11: The coating of any one of Aspects 1 to 10, wherein the core is 60% to 95% by mass of the total mass of the core / shell copolymer.

[0153] Aspect 12: The coating of any of Aspects 1 to 11, wherein the at least one (meth)acrylate functionalized monomer comprises at least one monomer selected from hydroxyethyl methacrylate, hydroxypropyl methacrylate, isobornyl methacrylate, polyethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate.

[0154] Aspect 13: The coating of any of Aspects 1 to 12, wherein the at least one (meth)acrylate functionalized oligomer comprises at least one (meth)acrylate functionalized urethane oligomer.

[0155] Aspect 14: The coating of any one of Aspects 1 to 13, wherein the at least one or more photoinitiators are present in a total amount of 0.1-5%, based on the total weight of the photocurable composition.

[0156] Aspect 15: The coating of any one of Aspects 1 to 14, wherein the photocurable composition has a viscosity of 100 to 5,000,000 cp at 25°C.

[0157] Aspect 16: The coating of any one of Aspects 1 to 15, wherein the photocurable composition further comprises at least one (meth)acrylic polymer that is not a core / shell copolymer.

[0158] Aspect 17: The coating of any of Aspects 1 to 16, wherein the coating has an impact strength at 25°C measured by energy loss per unit area of ​​at least 15 J / m or at least 20 J / m.

[0159] Aspect 18: The coating of any one of Aspects 1 to 17, wherein the nail is a human fingernail or toenail.

[0160] Aspect 19: A method for forming a coating on a nail, comprising the steps of:

[0161] a) placing a photocurable composition on the surface of the nail; and

[0162] b) exposing the photocurable composition to ultraviolet or visible light;

[0163] The photocurable composition comprises at least one (meth)acrylate functionalized monomer, at least one (meth)acrylate functionalized oligomer, at least one core / shell copolymer particle and at least one photoinitiator, or is a photocurable composition according to any one of aspects 1 to 18.

[0164] Aspect 20: The method of Aspect 19, wherein the photocurable composition is placed on the nail surface and formed into a continuous layer, followed by photocuring.

[0165] Aspect 21: A packaged article comprising a container and a photocurable composition disposed in the container, wherein the packaged article has a dispensing member capable of dispensing the photocurable composition from the container, and the photocurable composition comprises at least one (meth)acrylate functionalized monomer, at least one (meth)acrylate functionalized oligomer, at least one core / shell copolymer particle and at least one photoinitiator, or is a photocurable composition according to any one of Aspects 1 to 18.

[0166] Aspect 22: The packaged product of Aspect 21, wherein the container is a tube, a bottle or a syringe.

[0167] Aspect 23: The packaged article of Aspect 21 or 22, wherein the dispensing member is a brush, a foam applicator, a wick, a nozzle, a roller, a needle, or an orifice.

[0168] Aspect 24: A kit comprising: a packaged article including a container and a photocurable composition disposed within the container, at least one application device, and instructions for dispensing, applying, and curing the photocurable composition to provide a nail coating, wherein the photocurable composition comprises at least one (meth)acrylate functionalized monomer, at least one (meth)acrylate functionalized oligomer, at least one core / shell copolymer particle, and at least one photoinitiator, or is a photocurable composition according to any one of Aspects 1 to 18.

[0169] Aspect 25: The kit of Aspect 24, wherein the at least one application device comprises at least one of a brush, a pusher, or a spatula.

[0170] In this specification, the embodiments have been described in a manner that enables a clear and concise description to be written, but it is desired and will be appreciated that the embodiments may be variously combined or separated without departing from the invention. For example, it will be appreciated that all preferred features described herein may apply to all aspects of the invention described herein.

[0171] In some embodiments, the invention herein may be interpreted as not including any element or process step that does not substantially affect the basic and novel characteristics of the invention. In addition, in some embodiments, the invention may be interpreted as not including any element or process step not specified herein.

[0172] Although the invention has been illustrated and described herein with reference to particular embodiments, it is intended that the invention not be limited to the details shown. Rather, various changes may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.

[0173] Example

[0174] Two base photocurable compositions (base formulations 1 and 2) were prepared using the components listed in Table 1. The amounts listed are in parts by weight. All components (except the urethane oligomer) were added to a 4 ounce amber glass jar and then mixed on a roller at 60°C for 30 minutes. The urethane oligomer was then added to the jar and the formulation was further mixed on a roller at 60°C for another 1.5 hours to obtain a clear viscous solution.

[0175] Table 1.

[0176]

[0177] Six different polymer powders were blended into each of Base Formulations 1 and 2 in different percentages (10-40 wt. %, based on the total weight of base formulation + polymer powders).

[0178] The polymer powders used were as shown in Table 2. and All are registered trademarks of Arkema.

[0179] Table 2.

[0180]

[0181] The curable composition was prepared from the base formulation and the polymer powder according to the following procedure. The high-speed mixer cup was charged with 20 g of base formulation 1 or base formulation 2. Five grams of the specified polymer powder was added and the mixture was mixed at 3000 RPM for 4 minutes. In some cases, a slightly turbid low-viscosity liquid was obtained, while in other cases a slightly turbid high-viscosity gel was obtained. The difference in consistency depends on the amount of monomer and oligomer and / or the amount and type of core / shell particles.

[0182] The viscosity of each of the resulting photocurable compositions was measured using a Brookfield DV3T cone and plate viscometer. All measurements were performed on 0.5 mL samples at 25°C using a CPE-52Z cone. The shear rate was measured and the data was collected and analyzed using Rheocalc software. The measured viscosities are reported in Table 3. By way of comparison, a commercially available acrylic nail building / styling gel product was found to have a viscosity of 2,500,000 cp.

[0183] Table 3.

[0184]

[0185] The impact test of the photocurable composition was carried out according to the following procedure. Three samples of each photocurable composition were warmed in a 60°C oven, applied to a silicone mold, and cured using a Phoseon LED curing lamp at 395nm and 30fpm. The resulting cured block was cut and its impact strength was measured after allowing it to equilibrate overnight at 50% RH. The impact strength of the block was measured using a Zwick / Roell HIT5.5P cantilever beam impact tester. The results obtained are shown in Table 4. If a high molecular weight polymer powder comprising an acrylic copolymer (Polymer A) is used, the impact strength is very low (8.8J / m). However, a core / shell acrylic impact modifier ( 440) exhibited a two- to three-fold increase in the impact strength of the cured material (19.6 and 28.7 J / m, depending on the base formulation). 350 and The difference between 440 is the size of the rubber-like core. 440 achieves higher impact strength than using The impact strength observed in the case of 350. In the two base formulations containing The photocurable compositions of XT-100 had impact strengths of 29.8 J / m and 39.3 J / m respectively after curing. In contrast, a commercially available acrylic nail building / styling gel product was found to have an average energy loss per unit area of ​​12.7 J / m when cured and tested in the same manner.

[0186] Table 4.

[0187]

Claims

1. A coating on a nail, wherein the coating is a photocured product of a photocurable composition, wherein the photocurable composition comprises: a). at least one (meth)acrylate functionalized monomer; b). at least one (meth)acrylate functionalized oligomer; c) particles of at least one core / shell copolymer, wherein the at least one core / shell copolymer comprises a core comprising styrene and butadiene in copolymerized form and a shell comprising methyl methacrylate in polymerized form; and d). at least one photoinitiator, wherein the photocurable composition comprises 10 to 60% by weight of particles of the at least one core / shell copolymer, based on the total weight of the photocurable composition, wherein the particles of the at least one core / shell copolymer have an average particle size of 25 to 900 nm, and wherein the photocurable composition has a viscosity at 25°C of at least 200,000 cp.

2. The coating of claim 1, wherein the core / shell copolymer comprises a core comprising an elastomeric polymer having a glass transition temperature of less than 0°C and at least one shell comprising a non-elastomeric polymer having a glass transition temperature of at least 30°C.

3. The coating of claim 1 or 2, wherein particles of the at least one core / shell copolymer are suspended in a liquid matrix comprising a) and b).

4. The coating according to any one of claims 1 to 3, wherein the particles of the at least one core / shell copolymer have an average particle size of 40 to 600 nm.

5. The coating of any one of claims 1 to 4, wherein the photocurable composition comprises a total of 0 to 20% by weight of at least one non-reactive solvent, based on the weight of the photocurable composition.

6. The coating of any one of claims 1 to 5, wherein the photocurable composition comprises 10 to 55% or 10 to 50% by weight of particles of the at least one core / shell copolymer, based on the total weight of the photocurable composition.

7. The coating of any one of claims 1 to 6, wherein the at least one shell comprises in polymerized form at least one monomer selected from alkyl methacrylates having a C1-C12 alkyl chain, C6-C12 vinyl aromatic organic compounds, acrylonitrile and combinations thereof, wherein the shell is optionally crosslinked.

8. The coating of any one of claims 1 to 7, wherein the at least one shell comprises methyl methacrylate in polymerized form, wherein the shell is optionally cross-linked.

9. The coating of any one of claims 1 to 8, wherein the core comprises in polymerized form at least one monomer selected from C4-C12 conjugated dienes and C1-C12 alkyl acrylates.

10. The coating of any one of claims 1 to 9, wherein the photocurable composition further comprises a core / shell copolymer comprising a core comprising butyl acrylate in polymerized form and a shell comprising methyl methacrylate in polymerized form.

11. A coating as claimed in any one of claims 1 to 10, wherein the core is 60% to 95% by mass of the total mass of the core / shell copolymer.

12. The coating of any one of claims 1 to 11, wherein the at least one (meth)acrylate functionalized monomer comprises at least one monomer selected from hydroxyethyl methacrylate, hydroxypropyl methacrylate, isobornyl methacrylate, polyethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate.

13. The coating of any one of claims 1 to 12, wherein the at least one (meth)acrylate functionalized oligomer comprises at least one (meth)acrylate functionalized urethane oligomer.

14. The coating of any one of claims 1 to 13, wherein the at least one or more photoinitiators are present in a total amount of 0.1 - 5%, based on the total weight of the photocurable composition.

15. The coating according to any one of claims 1 to 14, wherein the photocurable composition has a viscosity at 25°C of 200,000 to 5,000,000 cp.

16. The coating of any one of claims 1 to 15, wherein the photocurable composition additionally comprises at least one (meth)acrylic polymer which is not a core / shell copolymer.

17. A coating according to any one of claims 1 to 16, wherein the coating has an impact strength measured by energy loss per unit area of ​​at least 15 J / m at 25°C.

18. A coating as claimed in any one of claims 1 to 17, wherein the nail is a human fingernail or toe nail.

19. A method for forming a coating on a nail, comprising the steps of: a) placing a photocurable composition on the surface of the nail; and b) exposing the photocurable composition to ultraviolet or visible light; The photocurable composition is as defined in any one of claims 1 to 18.

20. The method of claim 19, wherein the photocurable composition is placed on the nail surface and formed into a continuous layer and then photocured.

21. A packaged product comprising a container and a photocurable composition disposed within the container, wherein the packaged product has a dispensing member capable of dispensing the photocurable composition from the container, and the photocurable composition is as defined in any one of claims 1 to 18.

22. The packaged article of claim 21, wherein the container is a tube, a bottle or a syringe.

23. A packaged article as claimed in claim 21 or 22, wherein the dispensing member is a brush, a foam applicator, a wick, a nozzle, a roller, a needle or an orifice.

24. A set comprising: A packaged article comprising a container and a photocurable composition disposed within the container, at least one application device, and instructions for dispensing, applying and curing the photocurable composition to provide a nail coating, wherein the photocurable composition is as defined in any one of claims 1 to 18.

25. The kit of claim 24, wherein the at least one application device comprises at least one of a brush, a pusher, or a spatula.

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