Urethane (METH) acrylates for use in recycling or delaying process

Abstract

A curable urethane (meth) acrylate oligomer formed by reacting, in the presence of a catalyst, at least: (A) a first isocyanate-reactive component bearing at least one (meth) acrylate group and at least one isocyanate-reactive group; (B) a polyisocyanate component; and (C) a diisocyanate-reactive component bearing at least one acidic group and two isocyanate-reactive groups wherein the urethane (meth) acrylate oligomer has an acid content of at least 5 * 10 <-4 > mol acid / g oligomer wherein some of the acid groups are optionally neutralized. A cured ink or coating prepared from the oligomer, and at least one of a (meth) acrylate monomer or a (meth) acrylate oligomer, and optionally at least one additive, can be easily removed from a substrate by treatment with an aqueous base, allowing recycling of the substrate from which any ink or coating has been removed. A nail gel composition including the oligomer may also be more easily removed from a nail.

Description

Technical Field

[0001] The present invention relates to urethane (meth)acrylates, curable compositions based on said urethane (meth)acrylates, methods of using said urethane (meth)acrylates, and compositions and articles containing said urethane (meth)acrylates in cured form, particularly for use in inks and coatings to allow for easy removal of cured inks and coatings once subjected to recycling, immersion or delaminating conditions. Background Art

[0002] In view of the effects of climate change and the increasing rate of consumption of the natural resources of our planet, the chemical industry has become increasingly interested in ensuring sustainable consumption and production patterns. In the market segment of curable inks and coatings, this need is manifested in the development of technologies that allow for easy and substantially complete delamination of inks and coatings from their substrates. Such technologies would allow for the separate recycling or reuse of the substrates. Efforts have been made to allow for such separation and recycling, including those made by Siegwerk (which recently introduced a sacrificial deinking primer for labels and sleeves).

[0003] Another area of coatings that can benefit from improved ease of separation from their underlying substrate is the curable nail enamel segment. Curable nail coatings are applied to a consumer's bare nail to enhance its appearance and protect it from the stresses of daily life. Nail coatings typically consist of (meth)acrylate-functionalized monomers, (meth)acrylate-functionalized oligomers, non-reactive polymers, photoinitiators (including those for UV-curable nail coatings), and other additives such as pigments and fillers to yield a 100% solids UV-curable nail formulation. Curable nail coatings other than UV-curable nail coatings are common and include peroxide-curable coatings (including two-part curable coatings). Curable nail coatings (also referred to as enamels) can be applied in four coats - a base coat, two color coats, and a top coat. The base coat serves as an adhesive layer, while the color coats serve as cosmetic layers. Finally, the top coat provides durability and scratch resistance and helps prevent removal when the consumer is exposed to certain chemical or physical irritants. Once the nail coating is applied and cured under UV or LED light, the coating forms a durable crosslinked network that can last up to two weeks. However, typical UV-curable nail coatings can be difficult to remove, and in some cases, it can take up to 20 minutes using a solvent-based remover. To speed up the removability time, a nail technician can first abrade the surface of the nail polish with a rough buffer to break the crosslinked film, thus allowing for faster solvent penetration. This process can damage the nail plate and can make the consumer's cuticle and nail surface feel uncomfortable and / or damaged.

[0004] Most of the literature describing the removal of paint coatings or pressure-sensitive adhesive / laminate adhesive labels uses solvents with low vapor pressure or caustic-type solvents, both of which are non-biodegradable, environmentally harmful, and potentially harmful to the person using the solvent. See US2010008952A, WO2010115564A1. None of these removal processes are conducive to use in nail applications. SUMMARY OF THE INVENTION

[0005] In view of the prior art, it would be desirable to develop a system that allows a curable coating or ink to delaminate easily and substantially completely from a substrate without the need for a sacrificial primer layer. Additionally, it is advantageous to incorporate a trigger in the backbone of a UV-curable coating, ink, or nail polish that can undergo removal in the presence of a non-hazardous low-VOC aqueous remover rather than in the presence of water alone. In many applications, delamination of a coating or ink from its substrate in the presence of water alone would be undesirable. Moreover, typical nail polishes should have high water resistance such that the polish is not removed during handwashing, swimming, showering, or dishwashing. Accordingly, it would be desirable to provide a polish that can be removed as needed via an aqueous remover that can interact with the trigger in the backbone of the nail polish and cause the nail polish to be removed from the substrate.

[0006] The presence of the urethane (meth)acrylate of the present invention (also referred to as acidic or acid-functional urethane (meth)acrylate or AUA) in inks, coatings, and nail gels renders such inks, coatings, and nail gels readily removable from the substrates to which they are attached when subjected to the recycling conditions (or soaking conditions) described herein.

[0007] One aspect of the present invention is a curable urethane (meth)acrylate oligomer that does not have a free isocyanate group at the terminus of the oligomer and is formed by reacting at least the following in the presence of a catalyst:

[0008] (A) a first isocyanate-reactive component having at least one (meth)acrylate group and at least one isocyanate-reactive group;

[0009] (B) a polyisocyanate component; and

[0010] (C) a second isocyanate-reactive component having at least one acidic group and two isocyanate-reactive groups,

[0011] wherein the acid content of the urethane (meth)acrylate oligomer is at least 5 x 10 -4 mol acid / g oligomer.

[0012] Another aspect of the present invention is a composition comprising the urethane (meth)acrylate oligomer of the present invention.

[0013] Another aspect of the present invention is a cured composition obtained by curing a composition according to the present invention.

[0014] Another aspect of the present invention is a substrate coated with a cured composition according to the present invention.

[0015] Another aspect of the present invention is a nail coated with a cured composition according to the present invention.

[0016] Another aspect of the present invention is a method for manufacturing an article, comprising: applying a composition according to the present invention to a substrate; and curing the composition, wherein the substrate is metal, glass, plastic, composite material, wood, carbon, glass fiber, non-woven fabric, ceramic, concrete, stone, and their composites.

[0017] Another aspect of the present invention is a method for recycling a substrate coated with a cured composition according to the present invention, wherein the recycling method comprises: contacting the substrate coated with the cured composition with a recycling solution having a pH sufficient to delaminate the cured composition from the substrate; and recovering the substrate free of the cured composition from the recycling solution.

[0018] Another aspect of the present invention is a method for coating nails, comprising: applying a composition according to the present invention to the nails; and curing the composition.

[0019] Another aspect of the present invention is a method for removing a cured nail gel from nails, wherein the method for removing the cured nail gel comprises: immersing a nail coated with a cured composition according to the present invention in a soaking solution having a pH sufficient to delaminate the cured nail gel from the nail partially or completely; wherein, if the immersion step only delaminates the cured nail gel from the nail partially, leaving a part of the cured nail gel from the nail attached to the nail, then the method further comprises: manually removing the part of the cured nail gel attached to the nail from the nail while the nail is still in the soaking solution, or alternatively, after the nail is removed from the soaking solution.

[0020] A technician typically uses a tool to scrape the coating from the nail. By allowing at least partial delamination of the coating, the present invention allows for easier removal of the coating by providing a starting point for the technician to apply the tool. According to the method of the present invention, it is not necessary to chip the coating with a tool to start the removal. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following figures illustrate exemplary embodiments of the present invention and are not intended to otherwise limit the description of the present invention as described herein.

[0022] Figure 1 Photographs of glass plates coated with a control and a coating according to the present invention after being immersed in an aqueous solution (pH = 5) for 20 minutes are shown.

[0023] Figure 2 Shows photographs of glass plates coated with a reference and a coating according to the invention after immersion in an alkaline solution (pH = 9) for 20 minutes.

[0024] Figure 3 Shows photographs of glass plates coated with a reference and a coating according to the invention after immersion in both an aqueous solution (pH = 5) and an alkaline solution (pH = 9) for 20 minutes. Detailed Description

[0025] Definition

[0026] As defined herein, "acid content" is calculated as the total acid content (in mol) of the curable acid-functional urethane (meth)acrylate oligomer of the invention per gram of the compound before any neutralization of the acid groups has occurred (i.e., assuming that 100% of the acid groups are in their free acid (non-salt) form). When determining the acid content of a urethane (meth)acrylate oligomer in which at least some of its acid groups have been neutralized, for the purposes of this calculation, it is assumed that: (1) during the preparation of the oligomer, (2) after the oligomer has been prepared but before formulation with other components, (3) after the oligomer has been formulated with other components (one of which includes a base), and / or (4) in a recycle or immersion solution after the oligomer has been prepared, formulated, and cured, 100% of the acid groups are present as their free acid, whether or not a base is provided. Thus, the acid-functional urethane (meth)acrylate oligomers of the invention having a certain acid content encompass such AUAs in which none of the acid groups are neutralized or in which at least some (including most and up to 100%) of the acid groups are neutralized.

[0027] As defined herein, "acid group" refers to any functional group present in the curable urethane (meth)acrylate oligomer of the invention that contains an acidic hydrogen atom and mainly refers to a carboxylic acid group, but also includes functional groups such as sulfonic acid, phosphoric acid, phosphonic acid, and phosphinic acid.

[0028] As defined herein, "aliphatic compound" or "aliphatic group" or "aliphatic linker" refers to a non-aromatic and acyclic, linear or branched, saturated or unsaturated compound, group, or linker that may contain one or more ether bonds, ester bonds, amide bonds, urethane bonds, urea bonds, and mixtures thereof, and that may be substituted by one or more groups selected from, for example, alkyl, hydroxy, halogen (F, Cl, Br, I), isocyanate, carbonyl, amine, carboxylic acid, and where each R' is independently C 1 -C6 Alkyl group.

[0029] As defined herein, an "alicyclic compound" or "alicyclic group" or "alicyclic linking group" refers to a non-aromatic and cyclic compound, group or linking group, which may contain one or more aliphatic bonds and which may be substituted by one or more aliphatic groups.

[0030] As defined herein, a "C1-C5 group or compound" refers to a group or compound having 1 to 5 carbon atoms.

[0031] As defined herein, "nail" refers to a human fingernail or toenail and includes artificial extensions present on the fingernail or toenail.

[0032] As defined herein, a "recycling solution" or "soaking solution" is a solution that causes a cured composition (such as a film, coating, ink or nail gel) containing an acidic urethane (meth)acrylate of the present invention to peel or delaminate from the substrate to which the composition is attached when contacted therewith. Although the peeling or delamination of the composition containing the acidic urethane (meth)acrylate from the substrate to which it is attached is typically thorough and complete, partial peeling or delamination of the composition may also represent an acceptable or satisfactory result depending on the particular technical field involved, such as in the salon industry for nail treatments. In cases where the delamination is only partial, manual means (such as a cuticle pusher tool or finger pressure or other known suitable means) may be employed to remove the portion of the coating / composition that remains attached to the nail surface.

[0033] Carbamate (meth)acrylate oligomer

[0034] The curable urethane (meth)acrylate oligomers (also referred to herein as acid-functional or acidic urethane (meth)acrylate oligomers) are prepared from components (A), (B), (C) and optionally (D) and / or (E) in the presence of a catalyst. The relative amounts of the components are stoichiometrically determined (driven) to obtain the product as described herein, i.e., a bifunctional urethane (meth)acrylate without free isocyanate groups. More specifically, a second isocyanate-reactive component having at least one acidic group and two isocyanate-reactive groups (e.g., DMPA), a first isocyanate-reactive component having at least one (meth)acrylate group (e.g., caprolactone acrylate), and a polyisocyanate component (e.g., IPDI) can be mixed in the presence of a catalyst and an inhibitor and optionally with a solvent. The ingredients are mixed and allowed to undergo an exothermic reaction, and then heated to a temperature and for a time sufficient to reduce the free isocyanate to a de minimis amount. If a solvent is present, the solvent can be stripped off and replaced with a monomer as a process diluent. The catalyst is not particularly limited and can include tin-containing catalysts such as, but not limited to, tetrabutyltin, tetraoctyltin, and tetraphenyltin. In at least one embodiment, the reaction mixture for forming the acidic urethane (meth)acrylate can also contain other additives such as inhibitors, surfactants, fillers, stabilizers, pigments, solvents, etc.

[0035] The acidic urethane (meth)acrylate of the present invention can be used in curable compositions, preferably for films, coatings, adhesives, sealants, inks, 3D printing applications, electronics, composites, or cosmetics such as nail gels.

[0036] More specifically, the use of the acidic urethane (meth)acrylate of the present invention relates to their presence in curable compositions as coating compositions, more preferably for substrates including human nails (in the beauty salon industry), wood, plastics, metals, glass, fibers, textiles, leather, stone, ceramics, concrete, or composites.

[0037] Component (A)

[0038] Component (A) of the acidic carbamate (meth)acrylate of the present invention represents a first isocyanate-reactive component having at least one (meth)acrylate group and at least one isocyanate-reactive group. The isocyanate-reactive group is preferably a hydroxyl group. Suitable component (A) compounds include, but are not limited to, polyester (meth)acrylates, epoxy (meth)acrylates, polyether (meth)acrylates, urethane (meth)acrylates, (meth)acrylates with hydroxyl groups (which are actually partial (meth)acrylates of alkoxylated alkylene polyols or partial (meth)acrylates of polyols produced from di-polyol ethers of said alkylene polyols), and combinations thereof. Examples of di-polyol ethers include di-trimethylolpropane (diTMP) (tetrol) or di-pentaerythritol (diPE) (hexol: 6 OH). The alkylene polyol or the polyol corresponding to the di-alkylene polyol ether may have 2 to 6 hydroxyl groups.

[0039] According to at least one embodiment, in addition to the at least one (meth)acrylate group, component (A) may further comprise additional non-(meth)acrylate capable of free radical polymerization functional groups such as allyl or vinylic group.

[0040] In at least one embodiment, component (A) may comprise at least one (meth)acrylate functional group, particularly 1 to 5 (meth)acrylate groups, more particularly at least 2 or 3 (meth)acrylate groups. In one embodiment, component (A) is a polyol component comprising a monohydric alcohol having at least 1, preferably 1 to 5 (meth)acrylate groups. In another embodiment, component (A) is a dihydric alcohol having at least 1, preferably 1 to 4 (meth)acrylate groups. For example, component (A) may comprise a monohydric alcohol of formula (1) having 3 (meth)acrylate groups or a dihydric alcohol of formula (2) having two (meth)acrylate groups, the formulas are shown as follows:

[0041]

[0042] Wherein A' and B' represent the residues of the corresponding polyols (tetrols) partially esterified with acrylic acid, and they may be linear, cyclic or branched, substituted or unsubstituted hydrocarbon chains, wherein optional substituents include cyclic groups and / or heteroatoms. The chains A' and B' may include, for example, ester or ether groups.

[0043] Component (A) can be monomeric or oligomeric.

[0044] Suitable polyester (meth)acrylates include, but are not limited to, the reaction products of acrylic acid or methacrylic acid or mixtures thereof with hydroxyl-terminated polyester polyols, where the reaction process is carried out such that a significant concentration of residual hydroxyl groups remains in the polyester (meth)acrylate. The hydroxyl functionality of the polyester polyol can be di-, tri-, tetra-, penta- or higher.

[0045] The polyester polyol can be prepared by the polycondensation reaction of a di- or higher hydroxyl-functional component with a di- or higher functionality carboxylic acid or acid anhydride. The hydroxyl-functional and carboxylic acid components can each have a linear, branched, cycloaliphatic or aromatic structure and can be used individually or as a mixture. Examples of suitable dihydroxy-functional components include: 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,12-dodecanediol, 1,3-butanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, 1,4- and 1,6-dimethylolcyclohexane, C 36 -dimer diol, hydroquinone bis(2-hydroxyethyl) ether (HQEE), hydroxypivaloyl pivalate and ethoxylated and / or propoxylated derivatives of the above. Ethoxylated and / or propoxylated derivatives of bisphenol A or bisphenol F are also suitable. Examples of suitable trihydroxy and higher hydroxyl-functional components include: glycerol, trimethylolpropane, trimethylolethane, pentaerythritol, diglycerol, di-trimethylolpropane, di-pentaerythritol, sorbitol and ethoxylated and / or propoxylated derivatives of the above. Examples of suitable di-functional or higher-functional carboxylic acids include: malonic acid, succinic acid, maleic acid, fumaric acid, itaconic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, dodecanedioic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, dimer fatty acid, trimellitic acid, pyromellitic acid and acid anhydride derivatives of the above. Suitable polyester polyols can also be prepared by the ring-opening polymerization of lactones initiated by hydroxyl-functional initiator molecules such as those described above. Suitable lactones include α,α-dimethyl-β-propiolactone, γ-butyrolactone and ε-caprolactone.

[0046] Examples of epoxy (meth)acrylates include the reaction products of acrylic or methacrylic acid or mixtures thereof with glycidyl ethers or esters. The glycidyl ethers or esters can have aliphatic, cycloaliphatic or aromatic structures and contain from two up to about six epoxy functional groups. Bifunctional epoxy materials are preferred. The glycidyl ethers can be prepared from hydroxy-functional precursors and epoxides such as epichlorohydrin. Many of the hydroxy-functional components listed in the above section are suitable for the preparation of aliphatic glycidyl ethers. Specific examples of precursors of aliphatic glycidyl ethers include: 1,4-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 1,4- and 1,6-dihydroxymethylcyclohexane, poly(ethylene glycol), poly(propylene glycol), poly(tetramethylene glycol), trimethylolpropane, pentaerythritol, glycerol and sorbitol. Specific examples of precursors of aromatic glycidyl ethers include: bisphenol A, bisphenol F and resorcinol.

[0047] Examples of suitable polyether (meth)acrylates include the condensation reaction products of acrylic or methacrylic acid or mixtures thereof with polyether alcohols which are polyether polyols. Suitable polyether alcohols can be linear or branched materials containing ether bonds and terminal hydroxy groups. The polyether alcohols can be prepared by ring-opening polymerization of cyclic ethers such as tetrahydrofuran or alkylene oxides with initiator molecules. Suitable initiator molecules include water, the hydroxy-functional materials described above, polyester polyols and amines. Examples of suitable amines include: ethylenediamine, 4,4'-diaminodiphenylmethane, diethylenetriamine and hydroxyamines such as ethanolamine and diethanolamine. Examples of suitable alkylene oxides include: ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin and glycidol. The polyether (meth)acrylates can be used individually or in combination.

[0048] Examples of polyurethane (meth)acrylates include the addition polymerization products of the di- or polyisocyanates described below as component B with isocyanate-reactive ethylenically unsaturated components such as the polyester-, epoxy- or polyether (meth)acrylates described in the above section or the monomeric hydroxy (meth)acrylates described immediately below.

[0049] Examples of monomeric hydroxy(meth)acrylates are acrylates, methacrylates or mixed esters with simple diols, triols, tetraols or polyols, where the esterification process is carried out such that residual hydroxyl groups remain in the final product. Examples include the following (meth)acrylates: 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,12-dodecanediol, 1,3-butanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, 1,4- and 1,6-dihydroxymethylcyclohexane, glycerol, trimethylolpropane, trimethylolethane, pentaerythritol, diglycerol, di-trimethylolpropane, di-pentaerythritol and sorbitol. The monomeric hydroxy(meth)acrylates can be used individually or as a mixture.

[0050] In a preferred embodiment, component (A) comprises a lactone (meth)acrylate. Such compounds can be represented by the following formula:

[0051]

[0052] where

[0053] R 6 is H or methyl;

[0054] each R 7 is independently H or an alkyl group, preferably H;

[0055] Alk is an optionally alkoxylated alkylene group, especially ethylene, propylene or butylene;

[0056] p is an integer from 2 to 12, preferably from 3 to 6;

[0057] q ranges from 1 to 20.

[0058] Preferably, component (A) comprises a lactone (meth)acrylate selected from β-propiolactone (meth)acrylate, γ-butyrolactone (meth)acrylate, δ-valerolactone (meth)acrylate and ε-caprolactone (meth)acrylate, more preferably ε-caprolactone acrylate.

[0059] Component (B)

[0060] Component (B) comprises a polyisocyanate component, including diisocyanates. In at least one embodiment, component (B) may comprise a diisocyanate having two isocyanate functional groups, such as an aliphatic diisocyanate or an alicyclic diisocyanate (e.g., isophorone diisocyanate). In other embodiments, component (B) may comprise multiple isocyanate groups, such as three or four or more isocyanate groups.

[0061] Non-limiting examples of compounds that may comprise component (B) include diisocyanates or polyisocyanates, such as aliphatic, aromatic, and alicyclic structures having at least two isocyanate functional groups per molecule. Examples of suitable isocyanate components include: isophorone diisocyanate, hexamethylene diisocyanate, 2,3,3-trimethylhexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,5-naphthalene diisocyanate, 2,4- or 2,6-toluene diisocyanate and mixtures of their isomers, 4,4'-diphenylmethane diisocyanate. Polyisocyanates formed by generating isocyanurate or biuret structures are also suitable. Mixtures of isocyanates are also suitable.

[0062] Preferably, the polyisocyanate is an alicyclic diisocyanate having a cycloalkyl ring with at least one C 1 -C 3 alkyl substituent. More preferably, the polyisocyanate is isophorone diisocyanate (IPDI).

[0063] Component (C)

[0064] Component (C) comprises a second isocyanate-reactive component having at least one acidic group and two isocyanate-reactive groups. Without wishing to be bound by theory, it is believed that component (C) contributes to the dissolution of the oligomer in the composition. Thus, in at least one embodiment, the composition may not comprise a surfactant. In other embodiments, a surfactant may be added to aid in the dissolution of the oligomer.

[0065] Component (C) is different from component (A). The at least one acidic group is preferably selected from carboxylic acid groups, sulfonic acid groups, phosphoric acid groups, phosphonic acid groups, phosphinic acid groups, and their salts. The two isocyanate-reactive groups are preferably hydroxyl groups.

[0066] In one embodiment, component (C) may comprise a polyol having an acidic group selected from carboxylic acid groups, sulfonic acid groups, phosphoric acid groups, phosphonic acid groups, and phosphinic acid groups, and their salts. In particular, component (C) may comprise a diol having a carboxylic acid group or a sulfonic acid group, or a salt thereof.

[0067] Examples of component (C) include, but are not limited to, compounds containing at least two isocyanate-reactive functional groups and at least one acidic group, where the acidic group can be ionic or potentially ionic. Different types of combinations can be used. Ionic or potentially ionic groups include carboxylic acid groups, sulfonic acid groups, or phosphoric acid groups, or their alkali metal or quaternary amine salts. If the free acid form is used to prepare the oligomer, the acidic group can be neutralized to the salt form by adding a base before or during dissolution. Suitable bases include inorganic hydroxides, or carbonates, and amines, and combinations thereof. Specific examples of ionic / potentially ionic components with acidic properties include: glycolic acid, lactic acid, malic acid, citric acid, dimethylolpropionic acid (DMPA), dimethylolbutyric acid, 2-sulfo-1,4-butanediol, 2,5-dimethyl-3-sulfo-2,5-hexanediol, 2-aminoethanesulfonic acid, N-(1,1-dimethyl-2-hydroxyethyl)-3-amino-2-hydroxypropanesulfonic acid, 2-aminoethylaminoethanesulfonic acid, and salts of the above substances.

[0068] According to a preferred embodiment, component (C) is a diol with an acidic group selected from carboxylic acid groups, sulfonic acid groups, phosphoric acid groups, phosphonic acid groups, or hypophosphorous acid groups, preferably carboxylic acid groups or sulfonic acid groups, more preferably carboxylic acid groups, where the group is at least partially neutralized by a basic reagent.

[0069] According to a preferred embodiment, component (C) has the following structure:

[0070]

[0071] where A is hydrogen or C 1 -C 5 alkyl; and B is a bond (i.e., nil) or C 1 -C 5 aliphatic linking group; and m and n are independently 1, 2, 3, or 4, provided that component (C) is a C 4 -C 15 compound.

[0072] In a specific embodiment, component (C) comprises or is dimethylolpropionic acid (DMPA).

[0073] Component (D)

[0074] Component (D) is an optional component for forming the acidic carbamate (meth)acrylate oligomer of the present invention. The optional component (D) is a base. Suitable inorganic bases include alkali metal and alkaline earth metal hydroxides, bicarbonates, and carbonates (e.g., sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, calcium bicarbonate, calcium carbonate). Suitable organic bases include ammonia, pyridine, and amines (e.g., isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, diethanolamine, ethanolamine, 2-dimethylaminoethanol, 2-diethylaminoethanol, dicyclohexylamine, etc.).

[0075] Component (D) also includes amine synergists.

[0076] If present, the amount of component (D) can vary from zero to an amount that is stoichiometrically in excess of the amount of base required to neutralize all of the acidic sites of the oligomer. One factor is whether the oligomer is expected to be exposed to a base (e.g., a solution containing a base) after oligomer formation but before curing, or whether the basic solution will be used as a recycle solution or a soak solution. The intended recycle and soak conditions will also affect whether component (D) is included and the extent to which component (D) is included. In the case of a more basic recycle or soak solution and in the case of higher recycle or soak times and temperatures, it may not be necessary to include component (D) or component (D) may be included to a lesser extent.

[0077] Component (E)

[0078] Component (E) is an optional component for forming the acidic carbamate (meth)acrylate oligomer of the present invention. Thus, the oligomer can be formed by reacting a hydroxy-functionalized compound (E) with components (A), (B), and (C) and optionally a base (D). For example, the oligomer can be formed by reacting a polyol (E) with components (A), (B), and (C) and optionally a base (D).

[0079] Component (E) comprises a hydroxy-functionalized compound, such as a monohydric alcohol or a polyol, preferably a polyol. Component (E) is different from components (A) and (C). In embodiments of the acidic carbamate (meth)acrylate oligomer, component (E) is absent. If component (E) is present, then component (E) is preferably a hydrophilic compound, such as a polyether polyol, or component (E) is not present in an amount sufficient to adversely affect the water solubility of the acidic carbamate (meth)acrylate oligomer. In particular, the amount of component (E) can be less than 5 wt%, preferably less than 4 wt%, more preferably less than 2 wt%, even more preferably less than 1 wt% or even 0 wt%, based on the total weight of components (A), (B), (C), (D), and (E).

[0080] In at least one embodiment, component (E) is a polyol. According to at least one embodiment, component (E) can be added to increase the molecular weight of the curable composition of acidic urethane (meth)acrylate or to add additional functional groups to the curable composition of acidic urethane (meth)acrylate.

[0081] Examples of component (E) include, but are not limited to, one or more polyols having from 1 to about 6 isocyanate-reactive groups per molecule and a molecular weight of from about 200 to 5000 daltons. Suitable polyols include polyesters, polyethers, polycarbonates, polycaprolactones, polybutadienes, hydrogenated polybutadienes, polyacrylics, polysiloxanes, and fluorinated polyethers. Physical mixtures of the foregoing or hybrid polyols containing more than one structural type in the same molecule can be used.

[0082] According to at least one embodiment, component (E) can be monomeric or oligomeric.

[0083] In a preferred embodiment, when component (E) is present, component (E) is a polyether polyol, preferably polyethylene glycol.

[0084] Acid content, solubility and molecular weight

[0085] The acid content of the curable urethane (meth)acrylate oligomer of the present invention is at least 5×10 -4 mol acid / g oligomer, preferably at least 5.25×10 -4 mol acid / g oligomer, more preferably at least 5.5×10 -4 mol acid / g oligomer, more preferably at least 6×10 -4 mol acid / g oligomer, more preferably at least 7×10 -4 mol acid / g oligomer, more preferably at least between 6×10 -4 and 9.5×10 -4 mol acid / g oligomer, for example between 6.5×10 -4 and 9.25×10 -4 mol acid / g oligomer, for example between 7×10 -4 and 9×10 -4 mol acid / g oligomer, for example between 7.5×10 -4 and 8.5×10 -4 mol acid / g oligomer. In one embodiment, the upper limit of the acid content is not so high that the cured urethane (meth)acrylate oligomer is undesirably prone to delamination in the presence of water. For example, the acid content can be less than 10×10 -4mol acid / g of oligomer. As used herein, unless otherwise stated, the acid content refers to the number of moles of acid per gram of acidic (or acid-functional) urethane (meth)acrylate oligomer.

[0086] In the curable urethane (meth)acrylate oligomers of the present invention, the percentage of acid groups present in free acid form (i.e., fully protonated) can be from 0% (i.e., all acid groups are in neutralized (salt) form) to 100%. In various embodiments, preferably at least 5%, such as at least 10%, such as at least 15%, such as at least 20%, such as at least 25%, such as at least 30%, such as at least 35%, such as at least 40%, such as at least 45%, such as at least 50%, such as at least 55%, such as at least 60%, such as at least 65%, such as at least 70%, such as at least 75%, such as at least 80%, such as at least 85%, such as at least 90%, such as at least 95% of the acid groups are neutralized (i.e., in salt form). As mentioned above, the degree of neutralization will depend on many factors, including the expected recycling or immersion conditions.

[0087] Due to its acid content, the curable urethane (meth)acrylate oligomers of the present invention are completely or substantially water-soluble, especially at 25 °C. In particular, at least 80% by weight, preferably at least 85% by weight, more preferably at least 90% by weight, even more preferably at least 95% by weight, still more preferably at least 99% by weight of the curable urethane (meth)acrylate oligomers are soluble in water at 25 °C. This property easily distinguishes these oligomers from previously reported aqueous polyurethane dispersions that are insoluble or substantially insoluble in water.

[0088] In fact, aqueous polyurethane dispersions typically contain chain-extended oligomers with relatively high molecular weights. In a preferred embodiment, the curable urethane (meth)acrylate oligomers of the present invention have a number average molecular weight of 500 to 20,000 g / mol, preferably 800 to 10,000 g / mol, more preferably 1,000 to 5,000 g / mol.

[0089] Preferred structures and embodiments

[0090] In a preferred embodiment, the urethane (meth)acrylate oligomers of the present invention do not contain urea bonds.

[0091] In one embodiment, the urethane (meth)acrylate oligomer has the following formula (II):

[0092]

[0093] Wherein:

[0094] Each R 1 、R 2 and R 3 is independently a C 1 -C 12 aliphatic or alicyclic linking group;

[0095] R 4 is a residue of a polyol;

[0096] R 5 is hydrogen or methyl;

[0097] A is hydrogen or C 1 -C 5 alkyl;

[0098] B is a bond or a C 1 -C 5 aliphatic linking group; and

[0099] m and n are independently 1, 2, 3 or 4, provided that the total number of carbon atoms in A, B, m and n combined is an integer from 2 to 13; and

[0100] x and y are independently integers from 0 to 5;

[0101] z is 0 or from 1 to 10, and

[0102] optionally, at least a portion of the carboxylic acid groups are present in salt form rather than free acid form.

[0103] In one specific embodiment, the urethane (meth)acrylate oligomer has the following structure (III):

[0104]

[0105] Composition

[0106] The curable urethane (meth)acrylate oligomer can be incorporated into a composition such as an ink composition, a film composition, or a coating composition, or a nail gel composition. Accordingly, the present invention also relates to a composition (particularly an ink composition, a film composition, a coating composition, or a nail gel composition) comprising a curable urethane (meth)acrylate oligomer as defined above.

[0107] The composition of the present invention may comprise the following amounts of the curable urethane (meth)acrylate oligomer of the present invention: 5 to 100% by weight, particularly 10 to 95% by weight, more particularly 15 to 90% by weight, even more particularly 20 to 85% by weight, still more particularly 25 to 80% by weight, based on the total weight of the composition. In particular, the composition may comprise the following amounts of the curable urethane (meth)acrylate oligomer of the present invention: 5 to 50% by weight, or 10 to 50% by weight, or 15 to 50% by weight, or 20 to 50% by weight, or 25 to 50% by weight, or 30 to 50% by weight, based on the total weight of the composition. Alternatively, the composition may comprise the following amounts of the curable urethane (meth)acrylate oligomer of the present invention: 50 to 100% by weight, or 55 to 100% by weight, or 60 to 100% by weight, or 65 to 100% by weight, or 70 to 100% by weight, based on the total weight of the composition.

[0108] Such a composition is different from the aqueous polyurethane dispersions described in the prior art. In fact, the composition of the present invention is substantially free of water. In addition, the urethane (meth)acrylate oligomer of the present invention is not in the form of a solid dispersed in a liquid phase.

[0109] The composition of the present invention preferably further comprises at least one ethylenically unsaturated compound other than the urethane (meth)acrylate oligomer of the present invention.

[0110] As used herein, the term "ethylenically unsaturated compound" means a compound containing a polymerizable carbon-carbon double bond. A polymerizable carbon-carbon double bond is a carbon-carbon double bond that can react with another carbon-carbon double bond in a polymerization reaction. Polymerizable carbon-carbon double bonds generally are included in the group consisting of acrylate (including cyanoacrylate), methacrylate, acrylamide, methacrylamide, styrene, maleate, fumarate, itaconate, allyl, propenyl, vinyl, and combinations thereof, preferably selected from acrylate, methacrylate, allyl, and vinyl, more preferably selected from acrylate and methacrylate. The carbon-carbon double bonds of a benzene ring are not considered polymerizable carbon-carbon double bonds.

[0111] According to some preferred embodiments, the ethylenically unsaturated compound may comprise at least one of (meth)acrylate monomer or (meth)acrylate oligomer. In particular, the ethylenically unsaturated compound comprises (meth)acrylate monomer.

[0112] As used herein, the term “(meth)acrylate monomer” means a monomer containing a (meth)acrylate group, particularly an acrylate group. The term “(meth)acrylate oligomer” means an oligomer containing a (meth)acrylate group, particularly an acrylate group. The term “(meth)acrylate group” encompasses acrylate groups ( ) and methacrylate groups ( ).

[0113] According to some embodiments, the ethylenically unsaturated compound comprises a (meth)acrylate monomer. The ethylenically unsaturated compound may comprise a mixture of (meth)acrylate monomers.

[0114] The molecular weight of the (meth)acrylate monomer may be less than 600 g / mol, particularly 100 to 550 g / mol, more particularly 200 to 500 g / mol.

[0115] The (meth)acrylate monomer may have 1 to 6 (meth)acrylate groups, particularly 1 to 3 (meth)acrylate groups.

[0116] The (meth)acrylate monomer may comprise a mixture of (meth)acrylate monomers having different functionalities. For example, the (meth)acrylate monomer may comprise a mixture of (meth)acrylate monomers containing a single acrylate or methacrylate group per molecule (referred to herein as “mono-(meth)acrylate compounds”) and (meth)acrylate monomers containing 2 or more, preferably 2 or 3 acrylate and / or methacrylate groups per molecule.

[0117] In one embodiment, the (meth)acrylate monomer includes a mono-(meth)acrylate monomer. The mono-(meth)acrylate monomer may advantageously act as a reactive diluent and reduce the viscosity of the composition.

[0118] Examples of suitable mono(meth)acrylate monomers include, but are not limited to, mono-(meth)acrylates of aliphatic alcohols (wherein the aliphatic alcohol may be straight-chain, branched, or cycloaliphatic, and may be a monohydric alcohol, a dihydric alcohol, or a polyhydric alcohol, provided that only one hydroxyl group is (meth)acrylated); mono-(meth)acrylates of aromatic alcohols (such as phenols, including alkylated phenols); mono-(meth)acrylates of alkylaryl alcohols (such as benzyl alcohol); mono-(meth)acrylates of oligomeric and polymeric diols such as diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, and polypropylene glycol; mono-(meth)acrylates of monoalkyl ethers of diols and oligomeric diols; mono-(meth)acrylates of alkoxylated (such as ethoxylated and / or propoxylated) aliphatic alcohols (wherein the aliphatic alcohol may be straight-chain, branched, or cycloaliphatic, and may be a monohydric alcohol, a dihydric alcohol, or a polyhydric alcohol, provided that only one hydroxyl group of the alkoxylated aliphatic alcohol is (meth)acrylated); mono-(meth)acrylates of alkoxylated (such as ethoxylated and / or propoxylated) aromatic alcohols (such as alkoxylated phenols); caprolactone mono(meth)acrylate; and the like.

[0119] The following compounds are specific examples of mono(meth)acrylate monomers suitable for use in the compositions: methyl (meth)acrylate; ethyl (meth)acrylate; n-propyl (meth)acrylate; n-butyl (meth)acrylate; isobutyl (meth)acrylate; n-hexyl (meth)acrylate; 2-ethylhexyl (meth)acrylate; n-octyl (meth)acrylate; isooctyl (meth)acrylate; n-decyl (meth)acrylate; n-dodecyl (meth)acrylate; tridecyl (meth)acrylate; tetradecyl (meth)acrylate; hexadecyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate; 2- and 3-hydroxypropyl (meth)acrylate; 2-methoxyethyl (meth)acrylate; 2-ethoxyethyl (meth)acrylate; 2- and 3-ethoxypropyl (meth)acrylate; tetrahydrofurfuryl (meth)acrylate; alkoxylated tetrahydrofurfuryl (meth)acrylate; 2-(2-ethoxyethoxy)ethyl (meth)acrylate; cyclohexyl (meth)acrylate; glycidyl (meth)acrylate; isodecyl (meth)acrylate; lauryl (meth)acrylate; 2-phenoxyethyl (meth)acrylate; alkoxylated phenol (meth)acrylate; alkoxylated nonylphenol (meth)acrylate; cyclic trimethylolpropane formal (meth)acrylate; isobornyl (meth)acrylate; tricyclodecanemethanol (meth)acrylate; tert-butylcyclohexanol (meth)acrylate; trimethylcyclohexanol (meth)acrylate; diethylene glycol monomethyl ether (meth)acrylate; diethylene glycol monoethyl ether (meth)acrylate; diethylene glycol monobutyl ether (meth)acrylate; triethylene glycol monoethyl ether (meth)acrylate; ethoxylated lauryl (meth)acrylate; methoxypolyethylene glycol (meth)acrylate; hydroxyethyl-butylcarbamate (meth)acrylate; 3-(2-hydroxyalkyl) oxazolidone (meth)acrylate; and combinations thereof.

[0120] In one embodiment, the (meth)acrylate monomer may comprise a (meth)acrylate monomer having two or more (meth)acrylate groups per molecule.

[0121] Examples of suitable (meth)acrylate monomers having two or more (meth)acrylate groups per molecule include acrylates and methacrylates of polyols. Such polyols may be fully or partially esterified (with (meth)acrylic acid, (meth)acrylic anhydride, (meth)acryloyl chloride, etc.), provided that they have at least two (meth)acrylate functional groups per molecule.

[0122] Exemplary (meth)acrylate monomers containing two or more (meth)acryloxy groups per molecule may include: bisphenol A di(meth)acrylate; hydrogenated bisphenol A di(meth)acrylate; ethylene glycol di(meth)acrylate; diethylene glycol di(meth)acrylate; triethylene glycol di(meth)acrylate; tetraethylene glycol di(meth)acrylate; polyethylene glycol di(meth)acrylate; propylene glycol di(meth)acrylate; dipropylene glycol di(meth)acrylate; tripropylene glycol di(meth)acrylate; tetrapropylene glycol di(meth)acrylate; polypropylene glycol di(meth)acrylate; polytetramethylene glycol di(meth)acrylate; 1,2-butanediol di(meth)acrylate; 2,3-butanediol di(meth)acrylate; 1,3-butanediol di(meth)acrylate; 1,4-butanediol di(meth)acrylate; 1,5-pentanediol di(meth)acrylate; 1,6-hexanediol di(meth)acrylate; 1,8-octanediol di(meth)acrylate; 1,9-nonanediol di(meth)acrylate; 1,10-decanediol di(meth)acrylate; 1,12-dodecanediol di(meth)acrylate; neopentyl glycol di(meth)acrylate; 2-methyl-2,4-pentanediol di(meth)acrylate; polybutadiene di(meth)acrylate; cyclohexane-1,4-dimethanol di(meth)acrylate; tricyclodecane dimethanol di(meth)acrylate; metallic di(meth)acrylate; modified metallic di(meth)acrylate; glycerol di(meth)acrylate; glycerol tri(meth)acrylate; trimethylolethane tri(meth)acrylate; trimethylolethane di(meth)acrylate; trimethylolpropane tri(meth)acrylate; trimethylolpropane di(meth)acrylate; pentaerythritol di(meth)acrylate; pentaerythritol tri(meth)acrylate; pentaerythritol tetra(meth)acrylate; bis(trimethylolpropane) diacrylate; bis(trimethylolpropane) triacrylate; bis(trimethylolpropane) tetraacrylate; sorbitol penta(meth)acrylate; bis(pentaerythritol) tetraacrylate; bis(pentaerythritol) pentaacrylate; bis(pentaerythritol) hexa(meth)acrylate; tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate; and alkoxylated (e.g., ethoxylated and / or propoxylated) derivatives thereof; and combinations thereof.

[0123] The composition of the present invention may comprise the following amounts of (meth)acrylate monomers: 0 to 95% by weight, particularly 5 to 90% by weight, more particularly 10 to 80% by weight, even more particularly 15 to 75% by weight, still more particularly 20 to 70% by weight, based on the total weight of the composition. In particular, the composition may comprise the following amounts of (meth)acrylate monomers: 5 to 50% by weight, or 10 to 50% by weight, or 15 to 50% by weight, or 20 to 50% by weight, or 25 to 50% by weight, or 30 to 50% by weight, based on the total weight of the composition. Alternatively, the composition may comprise the following amounts of (meth)acrylate monomers: 50 to 99.5% by weight, or 55 to 99.5% by weight, or 60 to 99.5% by weight, or 65 to 99.5% by weight, or 70 to 99.5% by weight, based on the total weight of the composition.

[0124] In one embodiment, the ethylenically unsaturated compound comprises a (meth)acrylate oligomer. The ethylenically unsaturated compound may comprise a mixture of (meth)acrylate oligomers.

[0125] The (meth)acrylate oligomer can be selected to enhance flexibility, strength, and / or modulus among other properties of the cured polymer prepared using Composition A.

[0126] (Meth)acrylate oligomers may have 1 to 18 (meth)acrylate groups, particularly 2 to 6 (meth)acrylate groups, more particularly 2 to 6 acrylate groups.

[0127] The number average molecular weight of the (meth)acrylate oligomer may be equal to or greater than 600 g / mol, particularly 800 to 15,000 g / mol, more particularly 1,000 to 5,000 g / mol.

[0128] In particular, the (meth)acrylate oligomer may be selected from urethane (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, polyether (meth)acrylate oligomers, polydiene (meth)acrylate oligomers, polycarbonate (meth)acrylate oligomers, polyester (meth)acrylate oligomers, and mixtures thereof.

[0129] Based on the total weight of the composition, the composition of the present invention may contain 0 to 95% by weight, particularly 5 to 90% by weight, more particularly 10 to 80% by weight, even more particularly 15 to 75% by weight, still more particularly 20 to 70% by weight of (meth)acrylate oligomer. In particular, based on the total weight of the composition, the composition may contain 5 to 50% by weight, or 10 to 50% by weight, or 15 to 50% by weight, or 20 to 50% by weight, or 25 to 50% by weight, or 30 to 50% by weight of (meth)acrylate oligomer. Alternatively, based on the total weight of the composition, the composition may contain 50 to 99.5% by weight, or 55 to 99.5% by weight, or 60 to 99.5% by weight, or 65 to 99.5% by weight, or 70 to 99.5% by weight of (meth)acrylate oligomer.

[0130] The composition may contain one or more additives, including but not limited to antioxidants, UV absorbers, light stabilizers, foam inhibitors, solvents, flow or leveling agents, colorants, adhesion promoters, pigments, dispersants (wetting agents), slip additives, fillers, thixotropic agents, matting agents, thermoplastics such as acrylic resins without any functional groups capable of free radical polymerization, waxes or other various additives, including any additives conventionally used in the fields of coatings, sealants, adhesives, molding or inks.

[0131] In some embodiments of the present invention (including curable compositions intended to be cured by actinic radiation, including UV radiation), the compositions described herein containing curable urethane (meth)acrylate oligomers include at least one photoinitiator. A photoinitiator can be regarded as any type of substance that forms species that initiate the reaction and curing of the organic substances for polymerization present in the curable composition upon exposure to radiation (e.g., actinic radiation).

[0132] A free radical polymerization initiator is a substance that forms free radicals when irradiated. Free radical photoinitiators are particularly preferably used. Non-limiting types of free radical photoinitiators suitable for use in the curable compositions of the present invention include, for example, benzoin, benzoin ethers, acetophenones, benzyls, benzyl ketals, anthraquinones, phosphine oxides, α-hydroxy ketones, phenylglyoxylates, α-amino ketones, benzophenones, thioxanthones, xanthones, acridine derivatives, phenazene derivatives, quinoxaline derivatives and triazine compounds.

[0133] Suitable photoinitiators include those that are capable of generating free radicals when exposed to the necessary radiation, such as UV light. In one exemplary embodiment, the photoinitiator includes acylphosphine oxides (e.g., Irgacure® 819, Lucirin® TPO, and Lucirin® TPO-L); benzoyl ketals (e.g., Irgacure 651); α-hydroxy phenyl ketones such as Irgacure 184 or Darocur 1173), or mixtures thereof.

[0134] The amount of the photoinitiator can be appropriately varied depending on the selected photoinitiator, the amount and type of polymerizable species present in the curable composition, the radiation source and radiation conditions used, and other factors. However, typically, the amount of the photoinitiator can be from 0.05 wt% to 5 wt%, preferably from 0.1 wt% to 2 wt%, based on the total weight of the curable composition.

[0135] Suitable solvents are any solvents that will dissolve all other components in the curable urethane (meth)acrylate oligomer composition and include aliphatic or aromatic hydrocarbons (e.g., hexane, toluene, or xylene), alcohols (e.g., ethanol or propylene glycol), esters (e.g., ethyl acetate, n-butyl acetate), ketones (e.g., acetone, methyl isobutyl ketone, or methyl ethyl ketone), and ethers (e.g., propylene glycol methyl ether or dimethoxyethane). However, in other embodiments, the curable compositions of the present invention can be formulated without solvents, i.e., without any non-reactive volatile substances (substances having a boiling point of 150 °C or lower at atmospheric pressure). For example, the curable urethane (meth)acrylate oligomer composition of the present invention can contain little or no non-reactive solvent, such as less than 10%, or less than 5%, or less than 1%, or even 0% non-reactive solvent, based on the total weight of the curable composition. In a preferred embodiment, the curable urethane (meth)acrylate oligomer composition of the present invention can be substantially free of water, such as less than 10%, or less than 5%, or less than 1%, or even 0% water, based on the total weight of the curable composition. Thus, the curable urethane (meth)acrylate oligomer composition of the present invention may not be in the form of an aqueous curable polyurethane dispersion.

[0136] Any stabilizers known in the art related to (meth)acrylate-functionalized compounds can be used in the present invention. Quinones represent a particularly preferred type of stabilizer that can be used in the context of the present invention. As used herein, the term "quinone" includes both quinones and hydroquinones and their ethers such as monoalkyl, monoaryl, monoaralkyl, and bis(hydroxyalkyl) ethers of hydroquinone. Hydroquinone monomethyl ether is an example of a suitable stabilizer that can be utilized.

[0137] The concentration of the stabilizer in the curable composition will vary depending on the particular stabilizer or combination of stabilizers selected for use, and on the desired degree of stabilization and the sensitivity of the components in the curable composition to degradation in the absence of the stabilizer. However, typically, the curable composition is formulated to contain from 50 to 5000 ppm of the stabilizer.

[0138] The composition can be a film or coating composition comprising the urethane (meth)acrylate oligomer of the present invention and an optional photoinitiator. Such a composition can be particularly useful for forming a film on at least a portion of a substrate surface or coating at least a portion of a substrate surface.

[0139] The composition can be an ink composition comprising the urethane (meth)acrylate oligomer of the present invention and an optional photoinitiator. Such a composition can be particularly useful for printing an image or text on at least a portion of a substrate surface.

[0140] The composition can be a nail gel composition comprising the urethane (meth)acrylate oligomer of the present invention and an optional photoinitiator. Such a composition can be particularly useful for coating at least a portion of a nail surface. The nail gel composition of the present invention, which is intended to be cured by actinic radiation (including UV radiation), includes a photoinitiator. The nail gel composition of the present invention, which is intended to be cured in some other manner, such as peroxide curing (including two-part curing), does not require and typically does not contain a photoinitiator.

[0141] The composition can further comprise at least one of a (meth)acrylate monomer or a (meth)acrylate oligomer; and optionally, at least one additive.

[0142] Cured composition, coated substrate, and method for their preparation

[0143] The composition of the present invention can be used to obtain a cured composition.

[0144] Accordingly, the present invention also relates to a cured composition obtained by curing a composition as defined above.

[0145] The cured composition can be a cured film or coating. Alternatively, the cured composition can be a cured ink. Alternatively, the cured composition can be a cured nail gel.

[0146] The present invention also relates to a substrate coated with a cured composition according to the present invention. The substrate can be referred to as an article.

[0147] The present invention also relates to a method for manufacturing an article, comprising: applying a composition according to the present invention to a substrate; and curing the composition.

[0148] The substrate can be any suitable substrate, such as metal, glass, plastic (e.g., thermoplastic such as polyolefin, polycarbonate, acrylonitrile - butadiene - styrene (ABS), and their blends), composite material, wood, carbon, glass fiber, non - woven fabric, ceramic, concrete, stone, and their composites. In a preferred embodiment, the substrate is plastic.

[0149] Curing of the composition of the present invention can be carried out by any suitable method, such as free - radical, thermal, electron beam, redox, Michael addition, cationic, and / or anionic polymerization. One or more initiators, such as free - radical initiators (e.g., photoinitiators, peroxide initiators), can be present in the composition. Generally, the curing step can include one of the following: (1) exposing the composition to UV light or visible light; (2) exposing the composition to electron beam radiation; (3) initiating polymerization by using groups generated by redox; or (4) initiating polymerization by using groups generated by heat. Curing can be accelerated or facilitated by supplying energy to the composition, such as by exposing the composition to a radiation source, such as visible light or UV energy, and / or electron beam radiation. In an exemplary embodiment, the composition can be cured with UVC, UVB, UVA energy, and / or visible light. In an exemplary embodiment, the composition is cured with a UV light source utilizing UVA / UVB or only UVA, and substantially no UVC radiation is involved. In an exemplary embodiment, the composition is cured with high - energy radiation in the range of 0.01 to 10 W / cm 2 . Possible light sources include, but are not limited to, natural outdoor light, black light, fluorescent, or high - pressure mercury lamps.

[0150] In an exemplary embodiment, the curing is carried out by exposing the composition to ultraviolet radiation provided by one or more UV lamps, the UV lamps delivering an irradiance level of 0.01 to 10 W / cm 2 e.g., 1 to 10 W / cm 2 for a time between 1 second and 30 minutes, e.g., between 1 second and 10 minutes. In another embodiment, the curing is carried out by exposing the composition to electron beam radiation. In another embodiment, the curing is carried out by exposing the composition to heat in the presence of a peroxide initiator (thermal curing). In another embodiment, the curing occurs via redox polymerization, which is a two - part process involving a peroxide initiator (e.g., such as hydrogen peroxide, benzoyl peroxide, or tert - butyl hydroperoxide) as the first part, and a reducing agent (e.g., tertiary amines such as N,N - dimethylaniline, N - (4 - methoxyphenyl)pyrrolidine, and N - phenyldiethanolamine, sodium sulfite, sodium metabisulfite).

[0151] The composition of the energy-curable (meth)acrylate of the present invention is particularly suitable for curing using LED (light-emitting diode) curing (e.g., UV LED curing, using radiation from a UV LED device), and for high-speed applications (e.g., coatings).

[0152] Before curing, the composition containing the curable urethane (meth)acrylate oligomer can be applied to at least a portion of the surface of the substrate in any known conventional manner, such as by spraying, by brushing, by sponging, by scraping, by roll coating, by casting, by drum coating, by dipping, by curtain coating, by screen printing, or by other image transfer methods, by coating transfer, etc., and combinations thereof. Indirect application using a transfer process can also be used.

[0153] In one embodiment, the composition of the energy-curable urethane (meth)acrylate oligomer can be applied directly to the substrate or on one or more of a primer, a basecoat system, or other suitable layers to achieve the desired final appearance and properties. For example, the curable composition can be applied on a waterborne basecoat or a solvent-based basecoat.

[0154] The substrate can be any commercially relevant substrate, such as a high surface energy substrate or a low surface energy substrate, such as a metal substrate or a plastic substrate, respectively. The substrate can include metals, glass, plastics (e.g., thermoplastics such as polyolefins, polycarbonates, acrylonitrile butadiene styrene (ABS), and blends thereof), composites, wood, carbon, glass fibers, non-wovens, ceramics, concrete, stone, and combinations thereof. Depending on the specific application, the suitable dry film thickness range is from 5 to 200 microns. For 3D printing applications or electronic applications, the film can be thicker than 200 microns.

[0155] The present invention also relates to nails coated with the cured composition according to the present invention.

[0156] The present invention also relates to a method for coating nails, comprising: applying the composition according to the present invention to the nails; and curing the composition.

[0157] Curing can be carried out as described above. The nails can be human nails or artificial nails adhered to or intended to be adhered to human nails.

[0158] Method for recycling substrates / removing cured compositions

[0159] The present invention also relates to a method for recycling a substrate coated with a curable composition according to the present invention, wherein the recycling method comprises: contacting the substrate coated with the curable composition with a recycling solution having a pH sufficient to delaminate the curable composition from the substrate; and recovering the substrate free of the curable composition from the recycling solution.

[0160] The present invention also relates to a method for removing a cured nail gel from a nail, wherein the method for removing the cured nail gel comprises: immersing a nail coated with a curable composition according to the present invention in a soaking solution having a pH sufficient to delaminate the cured nail gel from the nail partially or completely; wherein, if the immersion step only delaminates the cured nail gel from the nail partially, leaving a portion of the cured nail gel from the nail attached to the nail, then the method further comprises manually removing the portion of the cured nail gel attached to the nail from the nail while the nail is still in the soaking solution or, alternatively, after the nail is removed from the soaking solution.

[0161] The recycling / soaking solutions described herein cause the cured acidic urethane (meth)acrylates of the present invention (and the compositions, films, etc. in which they are present) to peel (delaminate) from the substrates to which they are attached, resulting in effective recycling of the substrates.

[0162] In an exemplary embodiment, the recycling / soaking solution is an aqueous solution of a base (e.g., an inorganic base or an organic base). Other components may include, but are not limited to, surfactants and defoamers. The amount of the recycling / soaking solution used to effect the peeling (delamination) of the cured acidic urethane (meth)acrylate is not particularly limited and may be present in a large stoichiometric excess relative to the cured acidic urethane (meth)acrylate.

[0163] In one exemplary embodiment, the pH of the recycling solution or the soaking solution is basic, i.e., the pH is greater than 7. In one exemplary embodiment, the pH is greater than 7 and less than 13, such as greater than 7 and less than 12, such as greater than 7 and less than 11, such as greater than 7 and less than 10, such as greater than 7 and less than 9. The pH will depend on the degree to which the free acid groups of the urethane (meth)acrylate backbone have been neutralized by reacting such free acid groups with a base. As the prior neutralization increases, a recycling solution or a soaking solution having a lower pH can be used and it has the same effect on a composition having a urethane (meth)acrylate backbone with a lower degree of neutralization as a recycling solution or a soaking solution having a higher pH.

[0164] As used herein, the phrase "soaking solution" typically refers to a solution that contacts human skin via a finger or toe containing natural human nails or artificial nails (i.e., the human nails or artificial nails are the substrate). As a result, the components of the soaking solution must be compatible with exposure to human skin for a period of time sufficient to release the coating present on the nail surface. In one exemplary embodiment, the maximum pH of the soaking solution is 11 or less, such as 10 or less, such as 9 or less, such as 8 or less, such as greater than 7 and less than 9, such as greater than 7 and less than 8.

[0165] Suitable bases for inclusion in the recycle / soaking solution are not particularly limited and include inorganic bases and organic bases. Suitable inorganic bases include alkali metal and alkaline earth metal bicarbonates or carbonates (e.g., sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, calcium bicarbonate, calcium carbonate). Inorganic bases such as alkali metal and alkaline earth metal hydroxides (e.g., sodium hydroxide, potassium hydroxide, calcium hydroxide) are typically too caustic to be included in a soaking solution that will contact human skin, unless present in a diluted amount (e.g., 2 wt% or less in water). Suitable organic bases include ammonia, pyridine, and amines (e.g., isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, diethanolamine, ethanolamine, 2-dimethylaminoethanol, 2-diethylaminoethanol, dicyclohexylamine, etc.).

[0166] The ease of delamination depends on the ease with which the recycle solution can penetrate the coating or ink or film composition containing the cured urethane (meth)acrylate oligomer, which is affected by the physical properties of the composition, including the degree of crosslinking, glass transition temperature (Tg), and its hydrophilicity. The induced removability of these coatings is affected by four main conditions: 1) the crosslink density of the composition, 2) the number of functional groups initiated within the composition, 3) the removal time, and 4) the removal temperature. Crosslink density is important because if the composition is crosslinked too highly, the remover will not be able to penetrate through the film and initiate removability via a swelling mechanism. Additionally, a certain number of acidic functional groups must be present in the film that allows sufficient swelling. Removal time is important because it allows the water-based remover to penetrate the film, and the temperature of the remover during removal can help soften the film to increase permeability and fluidity. Regardless of the ease of removability of the composition containing the urethane acrylate of the present invention, it has been found that including the urethane acrylate of the present invention in such a composition makes such removability easier.

[0167] In one aspect of the present invention, without attempting to evaluate the percentage of acid groups in free acid form relative to the percentage of acid groups in neutralized form, the following test conditions can be used as a criterion for achieving complete delamination of a coating or film or ink or other composition containing a cured urethane (meth)acrylate oligomer from the substrate to which the coating or film or ink or other composition is attached: Complete delamination of the coating from the substrate occurs when the coated substrate is exposed to a 2% sodium hydroxide (NaOH) solution at 85 °C for 10 minutes. This can be achieved with the urethane acrylates of the present invention in some formulations (e.g., those that do not increase the crosslink density and utilize a sufficient amount of the urethane acrylates of the present invention) as well as in other formulations. Compared to similar formulations without the urethane acrylates of the present invention, the use of the urethane acrylates of the present invention increases the degree of delamination under such conditions.

[0168] Example

[0169] Example 1. Acidic carbamate (meth)acrylate

[0170] 1 mole of dimethylolpropionic acid (DMPA), 1.8 moles of SR495B (caprolactone acrylate), 2 moles of isophorone diisocyanate (IPDI), 0.2 wt% of BHT as an inhibitor, 0.09 wt% of dibutyltin dilaurate (DBTDL) as a catalyst, and 20 wt% of cyclopentanone as a process solvent were mixed well using air sparge and allowed to reach an exothermic temperature of 65 °C, then heated to 110 °C until all DMPA solids disappeared and the intermediate NCO stalled (<0.5%, by FTIR). Then 0.2 moles of the remaining SR495B was added and the reaction was carried out at 110 °C until the NCO% by FTIR (NCO% titration with DMPA interference) < 0.1%. Cyclopentanone was stripped at 100 °C / 10 mmHg with stirring. The acid content of the final product having the structure shown in Structure (III) was 0.0008 mol / gm.

[0171] Example 2. Acidic carbamate (meth)acrylate

[0172] Using air spraying, 1 mole of dimethylolpropionic acid (DMPA), 1.6 moles of PRO13061 (higher molecular weight caprolactone acrylate), 2 moles of isophorone diisocyanate (IPDI), 0.2 wt% of BHT as an inhibitor, and 0.09 wt% of DBTDL as a catalyst were mixed well, and the exothermic temperature was allowed to reach 100 °C, then heated to 110 °C until all DMPA solids disappeared and the intermediate NCO stopped (<1.2%, by FTIR). Then the remaining 0.4 moles of PRO13061 were added, and the reaction was carried out at 110 °C until the NCO% by FTIR (NCO% titration with DMPA interference) <0.1%. Since the viscosity of the neat product is low, no process solvent or monomer diluent is required in this reaction. The acid content of the final product having the structure shown in Structure (IV) is 0.0006 mol / gm.

[0173] Comparative Example 3. Acidic carbamate (meth)acrylate

[0174] Using air spraying, 1.3 moles of dimethylolpropionic acid (DMPA), 6.5 moles of isophorone diisocyanate (IPDI), 0.2 wt% of Irganox 1035 (BASF) as an inhibitor, 0.06 wt% of Reaxis C716 (bismuth carboxylate) as a catalyst, and 10 wt% of acetone as a process solvent were mixed well and heated to 78 °C, then maintained at 78 °C with stirring until all DMPA disappeared. 1 mole of poly(neopentyl adipate) diol polyester polyol with an MW of 500 Da (Fomrez® 55-225), 1 mole of CN104Z (Sartomer, epoxy acrylate), and 1.1 moles of SR356 (Sartomer, acrylate) were added to the mixture, and the exothermic temperature was allowed to reach 80 °C. The reaction was carried out at 80 °C until the intermediate NCO by FTIR <5.5%. Then 5.4 moles of methanol were added, and the reaction was carried out at 80 °C until the NCO% by FTIR <0.1%. Then acetone was stripped at 80 °C / 10 mmHg with stirring. The acid content of the final product is 0.0004 mol / gm. The urethane acrylate of Comparative Example 3 is insoluble in an alkaline aqueous solution. Its solubility is very different from that of the newly proposed acidic urethane (meth)acrylate of Examples 1 and 2 and cannot be used in the removability applications discussed herein.

[0175] Example 4. Cleaning properties of acidic carbamate (meth)acrylate

[0176] 5 g of the acidic urethane (meth)acrylate (AUA) of Example 1 was mixed with 5 g of deionized water. 0.5 g of a 25% NaOH solution was slowly added to neutralize the acid groups. Upon sonication, the mixture became homogeneous as the AUA was neutralized and dissolved in water. 4% of Speedcure KEM photoinitiator was added to this precious mixture and blended together. A film with a thickness of 0.1 - 0.2 mm was prepared on an aluminum plate and placed in a 65 °C oven for 2 minutes to evaporate the water and form a liquid acrylate film. At this stage, in the Impro unit with 400 W / inch 2 the dry liquid film was UV cured at 50 feet per minute. The cured film was hard and very difficult to scrape off the aluminum plate. The aluminum plate was placed in water, and in slightly over 2 minutes, the part of the film exposed to water absorbed water, swelled, and delaminated from the aluminum plate. The swollen film was very soft and easily ruptured.

[0177] Example 5. Formulation properties of acidic carbamate (meth)acrylate

[0178] Before and after the neutralization step of Example 4, the acidic urethane (meth)acrylate (AUA) of Example 1 was blended with SR9003B (which is propoxylated neopentyl glycol diacrylate) and 4% PL 460 photoinitiator in equivalent weights. Using the Impro curing unit with 400 W / inch 2 two different mixtures (one with the unneutralized AUA of Example 1 and one with the neutralized AUA of Examples 1 and 4) were printed on a PET flexible film with a thickness of 0.02 - 0.05 mm at 50 feet per minute. The cured films were cut into strips and placed in a 2% NaOH solution at 80 - 85 °C while stirring. The films were in the alkali solution for 10 minutes.

[0179] The formulated acidic (i.e., unneutralized) urethane (meth)acrylate showed signs of delamination but did not completely remove from the PET film. Standing overnight in the alkali bath at room temperature did show some swelling and overall delamination. This film behavior can be explained by the slow neutralization of the acid groups, followed by the swelling of the film. It is expected that using a more alkaline solution will shorten the delamination time.

[0180] The formulated neutralized acidic urethane (meth)acrylate film did swell and delaminate from the PET film within two minutes of exposure to the alkali bath. While stirring the alkali solution, the cured acrylate film did swell and disintegrate into smaller fragments. This film weakening was anticipated since the original neutralized acidic urethane (meth)acrylate swells and weakens upon exposure to water.

[0181] Example 6. Formulated acidic carbamate (meth)acrylate with amine synergist

[0182] The formulated, neutralized acidic urethane (meth)acrylate of Example 5 was blended with CN383 (an acrylated amine synergist) in a 1 to 1 molar ratio to neutralize the acid groups with a tertiary amine. IR data indicated a shift and reduction in the carbonyl peak of the carbonic acid when neutralized with a tertiary amine. The blend was mixed with 4% PL460 and a 0.02-0.05 mm thick film was prepared on a PET substrate. The films were cured using an Inpro Technologies mercury arc unit with 400 W / inch 2 The film was cured at 50 feet per minute. Similar to the previous examples, the cured film was placed in deinking conditions with an alkaline bath for 10 minutes. The cured film delaminated and disintegrated within 3 minutes. This film formulation did show a slight delay of 30-60 seconds when compared to the inorganic neutralized film.

[0183] Example 7 Coating composition using acidic carbamate methyl (acrylate) oligomer

[0184] A coating composition suitable as a UV-curable nail gel formulation is prepared by adding a primary oligomer (CN1968 or acidic CN1968, both of which are difunctional urethane (meth) acrylate oligomers), a monofunctional monomer (CN147MA) and a photoinitiator (TPO-1), and an acidic urethane acrylate (III) (as shown above) or (IV) (as shown below). The formulated compositions have an acid value of 5 mg KOH / g resin and 90 mg KOH / g resin, respectively, according to ASTM D 974. The acid value of the formulation is measured using a Mettler Toledo G20S AutoTitrator. Depending on the expected acid value, 0.5 g to 5 g of the formulation is added to a 125 mL plastic beaker. Acetone (30 mL) is added and the solution is mixed to dissolve the formulation. Water (1 mL) is added and mixed for 2 minutes. The stirring bar is removed and the electrode is immersed in the beaker. The acid value is measured using a LabX software package. 0.1 N NaOH was added as titrant to the solution by 'AutoTitrator' and an inflection point was visible after titration. The derivative of the pH curve was measured and it corresponded to the specific acid value recorded. The acid content of AUA(III) and AUA(IV) was maintained at 0.0008 mol / gm and 0.0006 mol / gm respectively.

[0185]

[0186] (IV)

[0187] The control formulation contains CN9067, which is a non-acid-functionalized oligomer of AUA(III). The components were added to a Flacktek polypropylene cup and mixed for 2 minutes at 2000 rpm using a Flacktek ® DAC 400.2 VAC high-speed mixer until homogeneous.

[0188] To prepare a UV-curable coating composition (which is suitable as a nail gel composition), the sample was pipetted onto a clean glass plate (4 inches × 4 inches). The sample was drawn down onto the glass using a ByK 3 mil drawdown bar. The coating was placed in a Gelish 18G LED nail lamp for 60 seconds. Once cured, the initial color, haze, and yellowness of the film were measured using a Hunter Lab ColorQuest XE spectrophotometer with the glass as a reference. Other performance characteristics such as surface tack, König hardness, and adhesion were also measured. The König hardness of the coating formulation was measured using ASTM D4366. The surface tack was qualitatively determined by assigning a number from an arbitrary scale between 0 - 5 (0 indicating no tack / 5 indicating very tacky).

[0189] Once cured, the glass plate with the coating was immersed in water or a 5% sodium bicarbonate solution for a specified period of time (5 minutes, 10 minutes, 15 minutes, 20 minutes). The coated plate was removed and the swellability / removability was visually measured.

[0190] A UV-curable coating formulation suitable as a nail gel formulation was prepared, which contains 25% loading of each of the acidic urethane acrylate oligomers (III) and acidic urethane acrylate (IV), and 47% loading of two different major oligomers (CN1968 and the acidic form of CN1968 containing DMPA acid attached to the backbone). All formulations contain 25% loading of a monofunctional monomer diluent (CN147MA) and 3% loading of a photoinitiator (TPO-1). The formulations were mixed, drawn down onto the glass, and cured using a Gelish 18G LED nail lamp. The performance characteristics were tested and are shown in the table below.

[0191]

[0192] The performance characteristics of the nail gel composition containing acidic urethane acrylate (III) and (IV) are very similar to those of the control formulation. For both the inventive and control samples, the initial color (APHA, 10 mm) and yellowness (b*) of the film after photocuring are very low. The initial haze of the inventive samples is lower compared to the control samples. The König hardness of all samples is similar before and after IPA wiping.

[0193] To determine whether the composition according to the present invention provides a triggered removal process, but is not easily delaminated in water alone (which would be undesirable), the removability of a control sample and the composition according to the present invention in an aqueous solution (pH = 5) was compared. Figure 1 Photographs of each glass plate with a nail coating applied thereto after soaking in an aqueous solution (pH = 5) for 20 minutes are shown. Figure 1 It was revealed that all coatings remained intact and adhered to the glass plates after a 20-minute water soaking time. The removability of the nail compositions in a sodium bicarbonate alkaline solution (pH = 9) at room temperature for 20 minutes was also tested. Figure 2 Pictures of the glass plates with nail coatings applied thereto after soaking in the alkaline solution (pH = 9) for 20 minutes are shown. Figure 2 It was revealed that for the compositions of Control 1 and Control 2, after soaking for 20 minutes, the coatings remained intact and adhered to the glass plates, and the compositions of Control 1 and Control 2 each did not contain acidic urethane acrylate. For the compositions 1, 2, 3, and 4 of the present invention (all containing 25% of acidic urethane acrylate III or IV), the film began to be removed from the glass surface and was excessively wrinkled due to swelling. Due to the addition of acidic CN1968, swelling was more obvious in the present invention 2 and the present invention 4 compared to the present invention 1 and the present invention 3, which helped to improve the removability. The alkaline aqueous solution was able to penetrate the film and cause the film to swell and delaminate from the glass plate. This only occurred in the alkaline aqueous solution at pH = 9, rather than in the aqueous solution (pH = 5), which is important for consumers.

[0194] Next, the amounts of acidic urethane acrylate III and IV required to induce removability in the alkaline solution (pH = 9) were evaluated. We chose to use only CN1968 as the main oligomer and did not choose non-acidic CN1968. UV-curable formulations suitable for use as nail gel formulations were prepared, which contained 14.3% and 33.3% loading of each acidic urethane acrylate oligomer (III) and acidic urethane acrylate (IV), and a loading of CN1968 between 42 and 54%. Again, all formulations contained 22 - 29% loading of a monofunctional monomer diluent (CN147MA) and approximately 3% loading of a photoinitiator (TPO-1). The formulations were mixed, pulled down onto the glass, and cured using a Gelish 18G LED nail lamp. The performance characteristics were tested and are shown in the table below.

[0195]

[0196] The performance characteristics of coating compositions containing acidic urethane acrylates (III) and (IV) at 12.5% and 37.5% loadings are very similar. This is important as it allows for the addition of more acidic urethane acrylate without changing the performance characteristics of the composition. As the amount of acidic urethane acrylate III increases, the initial color (APHA, 10 mm) and yellowness (b*) of the film increase slightly. The initial haze of all compositions remains low. The König hardness of all samples is similar before and after IPA wiping and is similar to that of previous compositions 1, 2, 3, and 4 according to the present invention. The removability of the coating composition is measured in both aqueous solution (pH = 5) and alkaline solution (pH = 9) to determine whether changing the amounts of acidic urethane acrylates III and IV has an effect on the swelling of the coating.

[0197] Figure 3 Compositions 5, 6, 7, and 8 of the present invention are shown compared to Control 1 composition. Compositions 7 and 8 of the present invention do show excellent swelling and removability in alkaline solution. Again, no composition shows any swelling / removability in aqueous solution (pH = 5).

[0198] For compositions 5 and 6 of the present invention, no swelling occurs. It is expected that more stringent soaking conditions (e.g., longer soaking times, higher temperatures, and / or higher pH) will result in some swelling. Crosslink density is important as if the composition is crosslinked too highly, the remover will not be able to penetrate through the film and initiate removability via the swelling mechanism. Additionally, a certain number of functional groups must be present in the film that allows for sufficient swelling. The data shows that 12.5% of the lower MW acidic urethane acrylate III with a higher crosslink density does not allow for the initiation of removability after soaking in alkaline solution for 20 minutes. However, 12.5% of the higher MW acidic urethane acrylate IV has much better swelling after soaking in alkaline solution for 20 minutes, and the higher MW acidic urethane acrylate IV has larger channels to allow the solvent to penetrate through the film due to its lower crosslink density.

[0199] In this specification, the embodiments have been described in a manner that enables the specification to be clear and concise, but it is intended and will be understood that the embodiments can be variously combined or separated without departing from the invention. For example, it will be understood that all of the preferred features described herein apply to all aspects of the invention described herein.

[0200] In some embodiments, the invention herein may be construed to exclude any element or process step that does not materially affect the basic and novel characteristics of the compositions and methods described herein. Additionally, in some embodiments, the invention may be construed to exclude any element or process step not specified herein.

[0201] Although the invention has been illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Instead, various modifications may be made in the details within the scope of the equivalents of the claims and without departing from the invention.

Claims

1. A curable urethane (meth)acrylate oligomer that does not have free isocyanate groups at the ends of the oligomer and is formed by reacting at least the following in the presence of a catalyst: (A) A first isocyanate-reactive component having at least one (meth)acrylate group and at least one isocyanate-reactive group; (B) A polyisocyanate component; and (C) A second isocyanate-reactive component having at least one acidic group and two isocyanate-reactive groups, wherein the acid content of the urethane (meth)acrylate oligomer is at least 5x10 -4 mol acid / g oligomer, for example at least 5.25x10 -4 , for example at least 5.5x10 -4 , preferably between 6x10 -4 and 9.5x10 -4 , more preferably between 6.5x10 -4 and 9.25x10 -4 , more preferably between 7x10 -4 and 9x10 -4 , and most preferably between 7.5x10 -4 and 8.5x10 - 4 mol acid / g oligomer.

2. The urethane (meth)acrylate oligomer according to claim 1, wherein the number-average molecular weight of the urethane (meth)acrylate oligomer is 500 to 20,000 g / mol, preferably 800 to 10,000 g / mol, more preferably 1,000 to 5,000 g / mol.

3. The urethane (meth)acrylate oligomer according to claim 1 or 2, wherein at least 80% by weight, preferably at least 85% by weight, more preferably at least 90% by weight, even more preferably at least 95% by weight, still more preferably at least 99% by weight of the curable urethane (meth)acrylate oligomer is soluble in water at 25 °C.

4. The urethane (meth)acrylate oligomer according to any one of claims 1-3, wherein the two isocyanate-reactive groups of component (C) are hydroxyl groups, and wherein the at least one acidic group of component (C) is selected from carboxylic acid groups, sulfonic acid groups, phosphoric acid groups, phosphonic acid groups, phosphinic acid groups, and their salts.

5. The urethane (meth)acrylate oligomer according to any one of claims 1-4, wherein the percentage of acid groups present in free acid form (i.e., fully protonated) is from 0% (i.e., all acid groups are in neutralized (salt) form) to 100%.

6. The urethane (meth)acrylate oligomer according to any one of claims 1-5, wherein the percentage of acid groups present in free acid form is at least 5%, such as at least 10%, such as at least 15%, such as at least 20%, such as at least 25%, such as at least 30%, such as at least 35%, such as at least 40%, such as at least 45%, such as at least 50%, such as at least 55%, such as at least 60%, such as at least 65%, such as at least 70%, such as at least 75%, such as at least 80%, such as at least 85%, such as at least 90%, such as at least 95%.

7. The urethane (meth)acrylate oligomer according to any one of claims 1-6, wherein the percentage of acid groups present in the neutralized (salt) form is at least 5%, for example at least 10%, for example at least 15%, for example at least 20%, for example at least 25%, for example at least 30%, for example at least 35%, for example at least 40%, for example at least 45%, for example at least 50%, for example at least 55%, for example at least 60%, for example at least 65%, for example at least 70%, for example at least 75%, for example at least 80%, for example at least 85%, for example at least 90%, for example at least 95%.

8. The urethane (meth)acrylate oligomer according to any one of claims 1-7, wherein component (C) has the following structure: Wherein: A is hydrogen or C 1 -C 5 alkyl; and B is a bond or C 1 -C 5 an aliphatic linking group; and m and n are independently 1, 2, 3 or 4, provided that component (C) is a C 4 to C 15 compound.

9. The urethane (meth)acrylate oligomer according to any one of claims 1-8, wherein component (C) is dimethylolpropionic acid.

10. The urethane (meth)acrylate oligomer according to any one of claims 1-9, wherein component (A) comprises a lactone (meth)acrylate selected from β-propiolactone (meth)acrylate, γ-butyrolactone (meth)acrylate, δ-valerolactone (meth)acrylate, and ε-caprolactone (meth)acrylate, and is preferably caprolactone acrylate.

11. The urethane (meth)acrylate oligomer according to any one of claims 1-10, wherein the polyisocyanate is an alicyclic diisocyanate having a cycloalkyl ring containing at least one C 1 -C 3 alkyl-substituted group.

12. The urethane (meth)acrylate oligomer according to any one of claims 1-11, wherein the polyisocyanate is isophorone diisocyanate.

13. The urethane (meth)acrylate oligomer according to any one of claims 1-12, wherein the oligomer is formed by reacting a base (D) with components (A), (B), and (C), or alternatively, by reacting the base (D) after the reaction of components (A), (B), and (C), the amount of the base (D) being such that most of the acid groups present in the oligomer are in the salt form rather than in the free acid form.

14. The urethane (meth)acrylate oligomer according to any one of claims 1-13, wherein the oligomer is formed by reacting a polyol (E) with components (A), (B), and (C) and optionally a base (D).

15. The urethane (meth)acrylate oligomer according to any one of claims 1-13, wherein the oligomer does not contain any polyol other than component (C).

16. The urethane (meth)acrylate oligomer according to any one of claims 1-15, having the formula (II): Wherein: Each R 1 , R 2 and R 3 is independently a C 1 -C 12 aliphatic or alicyclic linking group; R 4 is a residue of a polyol; R 5 is hydrogen or methyl; A is hydrogen or C 1 -C 5 alkyl; B is a key or C 1 -C 5 an aliphatic linking group; and m and n are independently 1, 2, 3, or 4, provided that the total number of carbon atoms in A and B, m, and n combined is an integer from 2 to 13; and x and y are independently integers from 0 to 5; z is 0 or from 1 to 10, and Optionally, at least a portion of the carboxylic acid groups are in the salt form rather than in the free acid form.

17. The urethane (meth)acrylate oligomer according to any one of claims 1-13 and 15, having the formula (III): 。 18. The urethane (meth)acrylate oligomer according to any one of claims 1-17, wherein the catalyst is a tin-containing catalyst.

19. A composition comprising the urethane (meth)acrylate oligomer according to any one of claims 1-18.

20. The composition according to claim 19, wherein the composition is not an aqueous polyurethane dispersion.

21. The composition according to claim 19 or 20, wherein the composition further comprises at least one ethylenically unsaturated compound other than the urethane (meth)acrylate oligomer according to any one of claims 1-16, particularly at least one of (meth)acrylate monomers or (meth)acrylate oligomers.

22. The composition according to any one of claims 19-21, wherein the composition further comprises a photoinitiator.

23. The composition according to any one of claims 19-22, wherein the composition is a film or coating composition.

24. The composition according to any one of claims 19-22, wherein the composition is an ink composition.

25. The composition according to any one of claims 19-22, wherein the composition is a nail gel composition.

26. A cured composition obtained by curing the composition according to any one of claims 19-25.

27. The cured composition according to claim 26, wherein the cured composition is a cured film or coating.

28. The cured composition according to claim 26, wherein the cured composition is a cured ink.

29. The cured composition according to claim 26, wherein the cured composition is a cured nail gel.

30. A substrate coated with the cured composition according to any one of claims 26-28.

31. A nail coated with the cured composition according to claim 29.

32. A method for manufacturing an article, comprising: applying the composition according to any one of claims 19-24 to a substrate; and curing the composition, wherein the substrate is metal, glass, plastic, composite material, wood, carbon, glass fiber, non-woven fabric, ceramic, concrete, stone, and their composites.

33. The method according to claim 32, wherein the substrate is plastic.

34. A method for recycling a substrate coated with the cured composition according to any one of claims 26-28, wherein the method for recycling comprises: contacting the substrate coated with the cured composition with a recycling solution having a pH sufficient to delaminate the cured composition from the substrate; and recovering the substrate free of the cured composition from the recycling solution.

35. The method according to claim 34, wherein the substrate is plastic.

36. The method according to claim 34 or 35, wherein the pH of the recycled solution is ≥7, such as greater than 7 and less than 13, such as greater than 7 and less than 12, such as greater than 7 and less than 11, such as greater than 7 and less than 10, such as greater than 7 and less than 9.

37. The method according to any one of claims 34 - 36, wherein delamination occurs within 10 minutes of exposure to the recycled solution.

38. The method according to any one of claims 34 - 37, wherein the pH of the recycled solution corresponds to a 2% NaOH solution, and delamination occurs within 10 minutes of exposure at 85 °C.

39. The method according to any one of claims 34 - 38, wherein the base is an inorganic base selected from sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

40. The method according to any one of claims 34 - 39, wherein the base is an organic base in the form of an amine.

41. A method for coating nails comprising: applying the composition according to any one of claims 19 - 22 and 25 to the nails; and curing the composition.

42. A method for removing a cured nail gel from nails, wherein the method for removing the cured nail gel comprises: immersing the nails coated with the cured composition according to claim 31 in a soaking solution having a pH sufficient to delaminate the cured nail gel from the nails partially or completely; wherein, if the immersion step only delaminates the cured nail gel from the nails partially, leaving a portion of the cured nail gel from the nails attached to the nails, then the method further comprises: manually removing the portion of the cured nail gel attached to the nails from the nails while the nails are still in the soaking solution, or alternatively, after the nails are removed from the soaking solution.

43. The method according to claim 42, wherein the pH of the soaking solution is ≥7.

44. The method according to claim 42 or 43, wherein the pH of the soaking solution is ≥7, such as greater than 7 and less than 11, such as less than 10, such as less than 9, such as greater than 7 and less than 8.

45. The method according to any one of claims 42 - 44, wherein the soaking solution contains a base selected from inorganic bases or organic bases.

46. The method according to any one of claims 42 - 45, wherein the base is an inorganic base selected from sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

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