HALS as antimicrobial additive in free radical systems

Abstract

The present invention relates to a method for protecting the surface of a substrate by providing a curable composition comprising a compound functionalized with a (meth) acrylate and HALS, applying the composition to the surface of a substrate, curing the composition, and converting HALS into halamine by treatment with a halogenating agent. Furthermore, the present invention relates to a curable composition comprising HALS, to a cured composition comprising halamine, and to the use of HALS to obtain an antimicrobial covering on the surface of a substrate.

Description

Technical Field

[0001] The present invention relates to a method for protecting the surface of a substrate by providing a curable composition comprising a (meth)acrylate functionalized compound and a HALS, applying the composition to the surface of the substrate, curing the composition, and converting the HALS to a halamine by treatment with a halogenating agent. The present invention also relates to a curable composition comprising a HALS, to a cured composition comprising a halamine, and to the use of a HALS to obtain an antimicrobial covering on the surface of a substrate. Background Art

[0002] Hindered amine light stabilizers (HALS) are low-cost, low-toxicity light stabilizers and heat stabilizers used in a wide range of commercially available materials, such as thermoplastic polymers, emulsions, and paints, and they can be further chemically modified to achieve different functions. In the presence of a halogenating agent, HALS can be converted into N-halogen-hindered amines (halamines) (Macromolecules 2005, 38, 8116-8119, Chem. Rev. 2017, 117, 4806-4862), which exhibit antimicrobial properties against both Gram-negative and Gram-positive bacteria. For example, hindered amine light stabilizer bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, which is reacted with sodium dichloroisocyanurate, has been described. N-chlorination of the obtained N-chlorinated compound and introducing the obtained N-chlorinated compound into a polyester-based paint (Progress in Organic Coatings 99 (2016) 330-336). US7,998,886 describes a fabric product comprising a plurality of yarns, wherein the yarns comprise HALS or halamine compounds arranged on their outer surfaces and / or dispersed in the inner portions of the yarns. US7,399,793 describes a UV-curable resin mixture containing HALS, which is sprayed onto a panel and cured to provide a protective clearcoat composition, but does not disclose the antimicrobial activity of the covering made therefrom.

[0003] There is a need for a simple and cost-effective method of providing an antimicrobial surface, wherein the antimicrobial properties of the surface can be replenished as needed, especially if the surface is also resistant to weathering (e.g., a light-resistant and heat-resistant surface). The present invention accomplishes these objects by providing a curable composition comprising a (meth)acrylate-functionalized compound and a HALS, applying the composition to a substrate surface, curing the composition, and converting the HALS to a halamine. Summary of the invention

[0004] One aspect of the present invention is a method for protecting the surface of a substrate, the method comprising:

[0005] - applying a curable composition comprising a (meth)acrylate-functional compound and a hindered amine light stabilizer (HALS) onto the surface of the substrate;

[0006] - curing the curable composition to provide a cured composition;

[0007] - treating the cured composition with a halogenating agent to halogenate the HALS present in the cured composition; and

[0008] - Optionally removing any residual halogenating agent.

[0009] Another aspect of the invention is a method of treating the cured composition with a halogenating agent to halogenate the HALS present in the cured composition, wherein the cured composition comprises the cured product of a curable composition comprising a HALS and a (meth)acrylate functionalized compound.

[0010] Another aspect of the invention is a curable composition comprising a (meth)acrylate-functional compound and a HALS, wherein the total amount of HALS in the composition is at least 3 wt%, preferably at least 6 wt%, based on the weight of the composition.

[0011] Another aspect of the present invention is a cured composition comprising an N-halo-hindered amine, wherein the cured composition is obtained by: (a) curing a curable composition according to the present invention; and (b) then converting the HALS into the N-halo-hindered amine by treating the HALS with a halogenating agent.

[0012] Another aspect of the present invention is the use of at least one HALS, at least one (meth)acrylate-functionalized compound and at least one halogenating agent for obtaining an antimicrobial covering on the surface of a substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings provided herein are illustrative of embodiments of the present invention and are not intended to limit the scope of the invention as described herein.

[0014] Figure 1 The results observed when a cotton swab soaked with ZnI / starch solution was swept over the surface of each of the cured samples 1, 2 and 3 after the cured samples were treated with bleach are shown as a test for the presence of halamines, wherein the color purple indicates the presence of halamines. No purple was observed on the cotton swab for sample 1 (PRO14589) as a control. No purple was observed on the cotton swab for sample 2 (PRO14589 and 2% Tinuvin A slight purple color was observed on the cotton swab used for sample 3 (PRO14589 and 5% Tinuvin ) was observed on the cotton swab. DETAILED DESCRIPTION

[0015] Curable composition

[0016] The present invention relates to a curable composition which can be applied to the surface of a substrate, subsequently cured and subsequently treated with a halogenating agent.

[0017] The curable composition comprises a (meth)acrylate functionalized compound and a hindered amine light stabilizer (HALS) as described in detail below. The curable composition may further comprise one or more additives as described in detail below.

[0018] (Meth)acrylate functionalized compounds

[0019] The curable composition comprises a (meth)acrylate functionalized compound.The curable composition may comprise a mixture of (meth)acrylate functionalized compounds.

[0020] The (meth)acrylate functionalized compound is different from a HALS. Accordingly, the (meth)acrylate functionalized compound may not have a hindered amine moiety. Preferably, the curable composition is substantially free of (meth)acrylate functionalized compounds having secondary amino groups other than HALS. Even more preferably, the curable composition is substantially free of (meth)acrylate functionalized compounds having amino groups other than HALS.

[0021] (Meth)acrylate functionalized compounds can be described as compounds with one or more (meth)acrylate functional groups per molecule. As used herein, "(meth)acrylate" refers to both methacrylate (-OC(=O)-C(CH3)=CH2) and acrylate (-OC(=O)-CH=CH2) functional groups. (Meth)acrylate functionalized compounds suitable for use in the present invention can be generally described as ethylenically unsaturated compounds (compounds containing at least one α,β-saturated ester moiety) containing at least one carbon-carbon double bond alpha to the ester group, particularly carbon-carbon double bonds that are capable of participating in free radical reactions or anionic reactions, particularly reactions initiated by exposure to UV energy, visible light, or electron beams. Such reactions can result in polymerization or curing, whereby the (meth)acrylate functionalized compound becomes part of a polymerized matrix or polymer chain. In various embodiments of the present invention, the (meth)acrylate functionalized compound can contain one, two, three, four, five or more (meth)acrylate functional groups per molecule. Combinations of various (meth)acrylate functionalized compounds containing different numbers of (meth)acrylate groups may be utilized in the curable compositions of the present invention.

[0022] The curable compositions of the present invention thus contain one or more (meth)acrylate functionalized compounds capable of free radical and / or anionic polymerization (curing), for example by exposure to UV energy, visible light or electron beams, to provide a cured composition.

[0023] The (meth)acrylate functionalized compound may be an oligomer or a monomer or a combination of oligomer(s) and monomer(s).

[0024] The curable composition may include a (meth)acrylate functionalized monomer.The curable composition may include a mixture of (meth)acrylate functionalized monomers.

[0025] The (meth)acrylate-functionalized monomer may have a molecular weight of less than 600 g / mol, specifically from 100 to 550 g / mol, more specifically 200 to 500 g / mol.

[0026] The (meth)acrylate-functional monomer may have 1 to 6 (meth)acrylate groups, in particular 1 to 3 (meth)acrylate groups.

[0027] The (meth)acrylate functionalized monomer may comprise a mixture of (meth)acrylate functionalized monomers having different functional groups. For example, the (meth)acrylate functionalized monomer may comprise a mixture of (meth)acrylate functionalized monomers containing a single acrylate or methacrylate group per molecule (referred to herein as "mono (meth)acrylate functionalized compounds") and (meth)acrylate functionalized monomers containing 2 or more, preferably 2 or 3, acrylate and / or methacrylate groups per molecule.

[0028] The curable composition may include a mono(meth)acrylate functionalized monomer. The mono(meth)acrylate functionalized monomer may advantageously act as a reactive diluent and reduce the viscosity of the composition.

[0029] Examples of suitable mono(meth)acrylate functionalized monomers include, but are not limited to, mono(meth)acrylates of aliphatic alcohols (wherein the aliphatic alcohol may be linear or branched and may be a monool, diol or polyol, provided that only one hydroxyl group is (meth)acrylated); mono(meth)acrylates of alicyclic or heterocyclic alcohols; mono(meth)acrylates of aromatic alcohols (such as phenols, including alkylated phenols); mono(meth)acrylates of alkylaryl alcohols (such as phenyl alcohol); mono(meth)acrylates of oligomeric and polymeric glycols such as diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol and polypropylene glycol; mono(meth)acrylates of monoalkyl ethers of diols or oligomeric glycols; caprolactone mono(meth)acrylates; and alkoxylated (i.e., ethoxylated and / or propoxylated) derivatives thereof; and combinations thereof.

[0030] The following compounds are specific examples of mono(meth)acrylate-functionalized monomers suitable for use in the curable composition: methyl(meth)acrylate; ethyl(meth)acrylate; n-propyl(meth)acrylate; isopropyl(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; isodecyl(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; 4-hydroxybutyl(meth)acrylate; 2-methoxyethyl(meth)acrylate; 2-ethoxyethyl(meth)acrylate; 2- and 3-ethoxy Propyl (meth) acrylate; Tetrahydrofurfuryl (meth) acrylate; 2-(2-ethoxyethoxy)ethyl (meth) acrylate; Cyclohexyl (meth) acrylate; Glycidyl (meth) acrylate; 2-phenoxyethyl (meth) acrylate; Benzyl (meth) acrylate; Phenol (meth) acrylate; Nonylphenol (meth) acrylate; Cyclic trimethylolpropane formal (meth) acrylate; Isobornyl (meth) acrylate; Tricyclodecane methanol (meth) acrylate; T-butyl cyclohexyl (meth) acrylate; Trimethyl cyclohexyl (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; Polyethylene glycol monomethyl ether (meth) acrylate; Hydroxyethyl-butyl carbamate (meth) acrylate; 3-(2-hydroxyalkyl) Oxazolidinone (meth) acrylate; (2,2-dimethyl-1,3-dioxolan-4-yl) methyl (meth) acrylate; (2-ethyl-2-methyl-1,3-dioxolan-4-yl) methyl (meth) acrylate; 1,3-dioxolan-5-yl (meth) acrylate; (1,3-dioxolan-4-yl) methyl (meth) acrylate; glycerol carbonate (meth) acrylate and its alkoxylated (i.e., ethoxylated and / or propoxylated) derivatives; and combinations thereof.

[0031] The curable composition may include a (meth)acrylate-functionalized monomer containing two or more (meth)acrylate-functional groups per molecule.

[0032] Examples of suitable (meth)acrylate functionalized monomers containing two or more (meth)acrylate groups per molecule include acrylate and methacrylate esters of polyols (organic compounds containing two or more, e.g., 2 to 6, hydroxyl groups per molecule). Specific examples of suitable polyols include ethylene glycol, 1,2- or 1,3-propylene glycol, 1,2-, 1,3-, or 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 3-methyl-1,5 -pentanediol, 3,3-dimethyl-1,5-pentanediol, neopentyl glycol, 2,4-diethyl-1,5-pentanediol, cyclohexanediol, cyclohexane-1,4-dimethanol, norbornene dimethanol, norbornene dimethanol, tricyclodecanediol, tricyclodecane dimethanol, bisphenol A, B, F, or S, hydrogenated bisphenol A, B, F, or S, trimethylolmethane, trimethylolethane, trimethylolpropane, di(trihydroxymethyl)propane propylene glycol), trihydroxyethyl propane, pentaerythritol, di(pentaerythritol), glycerol, di-, tri- or tetraglycerol, polyglycerol, di-, tri- or tetraethylene glycol, di-, tri- or tetrapropylene glycol, di-, tri- or tetrabutylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly(ethylene glycol-co-propylene glycol), sugar alcohols (i.e., erythritol, threitol, arabitol, xylitol, ribitol, mannitol, sorbitol, dulcitol, fucitol or aloesin), dextrin), dianhydrohexitol (i.e. isosorbide, isomannide or isoidide), tris(2-hydroxyethyl)isocyanurate, polybutadiene polyols, and alkoxylated (i.e. ethoxylated and / or propoxylated) derivatives thereof, derivatives obtained by ring-opening polymerization of lactones (e.g. laε-caprolactone) initiated by one of the above-mentioned polyols; and combinations thereof. Such polyols may be fully or partially esterified (by (meth)acrylic acid, (meth)acrylic anhydride, (meth)acryloyl chloride, etc.), provided that they contain at least two (meth)acrylate functional groups per molecule.

[0033] Exemplary (meth)acrylate functionalized monomers containing two or more (meth)acryloyloxy 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; 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 Acid esters; 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; metal di(meth)acrylate; modified metal 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 esters; pentaerythritol di(meth)acrylate; pentaerythritol tri(meth)acrylate; pentaerythritol tetra(meth)acrylate, di(trimethylolpropane) diacrylate; di(trimethylolpropane) triacrylate; di(trimethylolpropane) tetraacrylate, sorbitol penta(meth)acrylate; di(pentaerythritol) tetraacrylate; di(pentaerythritol) pentaacrylate; di(pentaerythritol) hexa(meth)acrylate; tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate; and alkoxylated (e.g., ethoxylated and / or propoxylated) derivatives thereof; and combinations thereof.

[0034] The total amount of (meth)acrylate-functionalized monomers in the curable composition can be from 0.1 to 97 wt %, from 1 to 95 wt %, from 5 to 93 wt %, from 10 to 90 wt %, from 15 to 85 wt %, from 20 to 80 wt %, from 25 to 75 wt %, based on the weight of the curable composition. In one embodiment, the total amount of (meth)acrylate-functionalized monomers in the curable composition may be from 10 to 97 wt%, from 15 to 97 wt%, from 20 to 97 wt%, from 25 to 97 wt%, from 30 to 97 wt%, from 35 to 97 wt%, from 40 to 97 wt%, from 45 to 97 wt%, from 50 to 97 wt%, from 55 to 97 wt%, from 60 to 97 wt%, from 65 to 97 wt%, from 70 to 97 wt%, from 75 to 97 wt%, from 80 to 97 wt%, from 85 to 97 wt%, or from 90 to 97 wt%, based on the weight of the curable composition. Alternatively, the total amount of (meth)acrylate-functionalized monomers in the curable composition can be from 0.1 to 50 wt%, from 1 to 50 wt%, from 5 to 50 wt%, from 10 to 50 wt%, from 15 to 50 wt%, from 20 to 50 wt%, from 25 to 50 wt%, from 30 to 50 wt%, based on the weight of the curable composition.

[0035] The curable composition may include a (meth)acrylate functionalized oligomer.The curable composition may include a mixture of (meth)acrylate functionalized oligomers.

[0036] The (meth)acrylate functionalized oligomer may be selected to enhance other properties such as flexibility, strength, and / or modulus of a cured polymer prepared using the curable composition.

[0037] The (meth)acrylate-functionalized oligomer may have 1 to 18 (meth)acrylate groups, specifically 2 to 6 (meth)acrylate groups, more specifically 2 to 6 acrylate groups.

[0038] The (meth)acrylate functionalized oligomer may have a number average molecular weight equal to or greater than 600 g / mol, specifically 800 to 15,000 g / mol, more specifically 1,000 to 5,000 g / mol.

[0039] In particular, the (meth)acrylate-functionalized oligomer may be selected from a (meth)acrylate-functionalized urethane oligomer (sometimes also referred to as "urethane (meth)acrylate oligomer", "polyurethane (meth)acrylate oligomer" or "carbamate (meth)acrylate oligomer"), a (meth)acrylate-functionalized epoxy oligomer (sometimes also referred to as "epoxy (meth)acrylate oligomer"), a (meth)acrylate-functionalized polyether oligomer (sometimes also referred to as "polyether (meth)acrylate"), or a (meth)acrylate-functionalized polyether oligomer. The present invention relates to (meth)acrylate-functionalized polydiene oligomers (sometimes also referred to as "polydiene (meth)acrylate oligomers"), (meth)acrylate-functionalized polycarbonate oligomers (sometimes also referred to as "polycarbonate (meth)acrylate oligomers"), (meth)acrylate-functionalized polyester oligomers (sometimes also referred to as "polyester (meth)acrylate oligomers"), and (meth)acrylate-functionalized (meth)acrylic oligomers (sometimes also referred to as "(meth)acrylic (meth)acrylate oligomers"), and mixtures thereof.

[0040] Preferably, the curable composition comprises a (meth)acrylate functionalized oligomer selected from the group consisting of (meth)acrylate functionalized urethane oligomers, (meth)acrylate functionalized epoxy oligomers, (meth)acrylate functionalized polyether oligomers, (meth)acrylate functionalized polyester oligomers, and mixtures thereof. More preferably, the curable composition comprises a (meth)acrylate functionalized urethane oligomer, even more preferably an acrylate functionalized urethane oligomer.

[0041] Advantageously, the curable composition comprises a (meth)acrylate functionalized urethane oligomer having two (meth)acrylate groups, more preferably an acrylate functionalized urethane oligomer having two acrylate groups.

[0042] Exemplary polyester (meth)acrylate oligomers include the reaction products of (meth)acrylic acid (or its synthetic equivalents such as (meth)acryloyl chloride, (meth)acrylic anhydride, or (meth)acrylate) and a polyester polyol terminated with hydroxyl groups. The reaction process may be carried out so that all or substantially all of the hydroxyl groups of the polyester polyol are (meth)acrylated, particularly where the polyester polyol is difunctional. The polyester polyol may be made by the polycondensation reaction of a polyhydroxyl-functional component (particularly a diol) and a poly(carboxylic acid)-functional compound (particularly a dicarboxylic acid and anhydride). The polyhydroxyl-functional compound and the poly(carboxylic acid)-functional compound may each have a linear, branched, alicyclic or aromatic structure and may be used alone or as a mixture.

[0043] Examples of suitable epoxy (meth)acrylates include the reaction products of (meth)acrylic acid (or its synthetic equivalents such as (meth)acryloyl chloride or (meth)acrylic anhydride) and an epoxy resin comprising at least one epoxide group, in particular at least one group selected from glycidyl ethers, glycidyl esters, and mixtures thereof. The epoxy resin may in particular be selected from bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, brominated bisphenol S diglycidyl ether, epoxy novolac resins ... resin), hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3,4-epoxycyclohexyl methyl-3',4'-epoxycyclohexanecarboxylate, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-1,4-dioxane, bis(3,4-epoxycyclohexylmethyl)adipate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, 3,4-epoxy-6-methylcyclohexyl-3',4'-epoxy-6'-methylcyclohexanecarboxylate, methylene bis(3,4-epoxycyclohexane), dicyclopentadiene diepoxide, ethylene glycol bis(3,4-epoxycyclohexylmethyl) ether, ethylene bis(3, 4-epoxycyclohexanecarboxylate), 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polyglycidyl ether of polyether polyol obtained by adding one or more alkylene oxides to an aliphatic polyol such as ethylene glycol, propylene glycol, and glycerol, diglycidyl esters of aliphatic long-chain dibasic acids, monoglycidyl ethers of aliphatic higher alcohols, monoglycidyl ethers of phenol, cresol, butylphenol, or polyether alcohols obtained by adding alkylene oxides to these compounds, glycidyl esters of higher fatty acids, epoxidized soybean oil, epoxybutyl stearic acid, epoxyoctyl stearic acid, epoxidized linseed oil, epoxidized polybutadiene, and the like.

[0044] Suitable polyether (meth) acrylate oligomers include, but are not limited to, condensation products of (meth) acrylic acid (or its synthetic equivalents such as (meth) acryloyl chloride, (meth) acrylic anhydride or (meth) acrylate) and hydroxyl group-terminated polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol and copolymers thereof. Suitable polyether polyols may be linear or branched materials containing ether bonds and terminal hydroxyl groups. Polyether polyols may be prepared by ring-opening polymerization of cyclic ethers such as tetrahydrofuran and / or alkylene oxides (e.g., ethylene oxide and / or propylene oxide) with initiator molecules. Suitable initiator molecules include water, polyhydroxyl-functionalized materials, polyester polyols and amines.

[0045] Suitable urethane (meth)acrylate oligomers include, but are not limited to, urethanes based on at least one polyol, at least one polyisocyanate, and at least one hydroxyl-functional (meth)acrylate.

[0046] Urethane (meth) acrylate oligomers can be prepared by reacting a polyisocyanate (e.g., an aliphatic, alicyclic and / or aromatic diisocyanate or triisocyanate) with a polyol (e.g., a polyester polyol, a polyether polyol, a polycarbonate polyol, a polycaprolactone polyol, a polyorganosiloxane polyol, or a polydiene polyol such as a polybutadiene polyol or a combination thereof) to form an isocyanate-functionalized oligomer, which is then reacted with a hydroxyl-functionalized (meth) acrylate (e.g., hydroxyethyl (meth) acrylate) to provide a terminal (meth) acrylate group. For example, the polyurethane (meth) acrylate oligomer may contain two, three, four or more (meth) acrylate functional groups per molecule. As is known in the art, other orders of addition may also be used to prepare polyurethane (meth) acrylates. For example, a hydroxyl-functionalized (meth) acrylate may first be reacted with a polyisocyanate to obtain an isocyanate-functionalized (meth) acrylate, which may then be reacted with a polyol. Alternatively, all components may be combined and reacted simultaneously.

[0047] Suitable acrylic (meth)acrylate oligomers include oligomers that can be described as materials having an oligomeric acrylic backbone functionalized with one or more (meth)acrylate groups (the one or more (meth)acrylate groups can be located at the end of the oligomer or pendant to the acrylic backbone). The acrylic backbone can be a homopolymer, a random copolymer, or a block copolymer composed of repeating units of acrylic monomers. The acrylic monomers can be any monomeric (meth)acrylate, such as C1-C6 alkyl (meth)acrylates and functionalized (meth)acrylates such as (meth)acrylates with hydroxyl, carboxylic acid and / or epoxy groups. Acrylic (meth)acrylate oligomers can be prepared using any procedure known in the art, such as by oligomerizing a monomer, at least a portion of which is functionalized with hydroxyl, carboxylic acid and / or epoxy groups (e.g., hydroxyalkyl (meth)acrylates, (meth)acrylic acid, glycidyl (meth)acrylates) to obtain a functionalized oligomer intermediate, which is then reacted with one or more (meth)acrylate-containing reactants to introduce the desired (meth)acrylate functional groups.

[0048] The total amount of (meth)acrylate functionalized oligomers in the curable composition can be from 0.1 to 97 wt %, from 1 to 95 wt %, from 5 to 93 wt %, from 10 to 90 wt %, from 15 to 85 wt %, from 20 to 80 wt %, from 25 to 75 wt %, based on the weight of the curable composition. In one embodiment, the total amount of (meth)acrylate functionalized oligomers in the curable composition may be from 10 to 97 wt%, from 15 to 97 wt%, from 20 to 97 wt%, from 25 to 97 wt%, from 30 to 97 wt%, from 35 to 97 wt%, from 40 to 97 wt%, from 45 to 97 wt%, from 50 to 97 wt%, from 55 to 97 wt%, from 60 to 97 wt%, from 65 to 97 wt%, from 70 to 97 wt%, from 75 to 97 wt%, from 80 to 97 wt%, from 85 to 97 wt%, or from 90 to 97 wt%, based on the weight of the curable composition. Alternatively, the total amount of (meth)acrylate functionalized oligomers in the curable composition can be from 0.1 to 50 wt%, from 1 to 50 wt%, from 5 to 50 wt%, from 10 to 50 wt%, from 15 to 50 wt%, from 20 to 50 wt%, from 25 to 50 wt%, from 30 to 50 wt%, based on the weight of the curable composition.

[0049] In one embodiment, the curable composition comprises an amine-modified acrylate or a thiol-modified acrylate. The ethylenically unsaturated compound may comprise a mixture of amine-modified acrylates or thiol-modified acrylates. Alternatively, the curable composition may be substantially free of amine-modified acrylates or thiol-modified acrylates.

[0050] Amine-modified acrylates or thiol-modified acrylates are obtained by reacting an acrylate-functional compound with an amine-containing compound or a thiol-containing compound. Amine-modified acrylates or thiol-modified acrylates contain at least one residual acrylate group (i.e., an acrylate group that has not reacted with an amine-containing compound or a thiol-containing compound) and / or at least one (meth)acrylate group (which may be non-reactive toward primary or secondary amines or thiols).

[0051] The acrylate functional compound may be an acrylate functional monomer and / or an acrylate functional oligomer as defined above.

[0052] The amine-containing compound comprises a primary or secondary amino group and optionally a tertiary amino group. The thiol-containing compound comprises a thiol group (—SH). The amine-containing compound may comprise more than one primary and / or secondary amino group. The thiol-containing compound may comprise more than one thiol group. The amine-containing compound may be selected from monoethanolamine (2-aminoethanol), 2-ethylhexylamine, octylamine, cyclohexylamine, sec-butylamine, isopropylamine, diethylamine, diethanolamine, dipropylamine, dibutylamine, 2-(methylamino)ethanol-1,2-methoxyethylamine, bis(2-hydroxypropyl)amine, diisopropylamine, diamylamine, dihexylamine, bis(2-ethylhexyl)amine, 1,2,3,4-tetrahydroisoquinoline, N-benzylmethylamine, morpholine, piperidine, dioctylamine, and di-coconutamine, dimethylaminopropylamine, dimethylaminopropylaminopropylamine, 1,4-bis(3-aminopropyl)piperazine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(3-aminopropyl)piperazine, aniline, and optionally substituted benzocaine (ethyl-4-aminobenzoate).

[0053] Examples of commercially available amine-modified acrylates include CN3705, CN3715, CN3755, CN381 and CN386, all available from Arkema. Polymeric or polyamino forms are also suitable.

[0054] The curable composition may contain from 0 to 25 wt %, specifically 2.5 to 20 wt %, more specifically 5 to 15 wt % of the amine-modified acrylate, based on the total weight of the composition.

[0055] In particularly preferred embodiments, the (meth)acrylate-functionalized compounds of the curable composition comprise one or more (meth)acrylate-functionalized monomers having from 1 to 6 (meth)acrylate groups per molecule, optionally in combination with one or more (meth)acrylate-functionalized oligomers containing two or more (meth)acrylate groups per molecule, the (meth)acrylate-functionalized oligomers being selected from the group consisting of (meth)acrylate-functionalized urethane oligomers, (meth)acrylate-functionalized epoxy oligomers, (meth)acrylate-functionalized polyether oligomers, (meth)acrylate-functionalized polyester oligomers, and mixtures thereof.

[0056] Preferably, the total amount of (meth)acrylate-functionalized compounds in the curable composition may be from 0.1 to 97 wt %, from 1 to 95 wt %, from 5 to 93 wt %, from 10 to 90 wt %, from 15 to 85 wt %, from 20 to 80 wt %, from 25 to 75 wt %, based on the weight of the curable composition. In one embodiment, the total amount of (meth)acrylate-functionalized compounds in the curable composition may be from 10 to 97 wt%, from 15 to 97 wt%, from 20 to 97 wt%, from 25 to 97 wt%, from 30 to 97 wt%, from 35 to 97 wt%, from 40 to 97 wt%, from 45 to 97 wt%, from 50 to 97 wt%, from 55 to 97 wt%, from 60 to 97 wt%, from 65 to 97 wt%, from 70 to 97 wt%, from 75 to 97 wt%, from 80 to 97 wt%, from 85 to 97 wt%, or from 90 to 97 wt%, based on the weight of the curable composition. Alternatively, the total amount of (meth)acrylate-functionalized compounds in the curable composition can be from 0.1 to 50 wt %, from 1 to 50 wt %, from 5 to 50 wt %, from 10 to 50 wt %, from 15 to 50 wt %, from 20 to 50 wt %, from 25 to 50 wt %, from 30 to 50 wt %, based on the weight of the curable composition.

[0057] The curable composition may contain ethylenically unsaturated compounds other than (meth)acrylate functionalized compounds. Examples of such compounds include allyl functionalized compounds, vinyl functionalized compounds, olefins (such as 1,1-diester-1-olefins, 1,1-diketone-1-olefins, 1-ester-1-keto-1-olefins, 1,1-diamide-1-olefins, 1-amide-1-keto-1-olefins, 1-amide-1-ester-1-olefins and / or itaconates) and combinations thereof.

[0058] The relative proportions of the ethylenically unsaturated compounds other than the (meth)acrylate functionalized compounds and the (meth)acrylate functionalized compounds may be appropriately varied depending on the specific components selected and the curable composition and the desired properties of the cured composition obtained therefrom. For example, the total weight of the ethylenically unsaturated compounds (including the (meth)acrylate functionalized compounds) in the curable composition may be from 0.1 to 97 wt %, from 1 to 95 wt %, from 5 to 93 wt %, from 10 to 90 wt %, from 15 to 85 wt %, from 20 to 80 wt %, from 25 to 75 wt %, based on the weight of the curable composition. In particular, the total weight of ethylenically unsaturated compounds (including (meth)acrylate-functionalized compounds) in the curable composition can be from 10 to 97 wt%, from 15 to 97 wt%, from 20 to 97 wt%, from 25 to 97 wt%, from 30 to 97 wt%, from 35 to 97 wt%, from 40 to 97 wt%, from 45 to 97 wt%, from 50 to 97 wt%, from 55 to 97 wt%, from 60 to 97 wt%, from 65 to 97 wt%, from 70 to 97 wt%, from 75 to 97 wt%, from 80 to 97 wt%, from 85 to 97 wt%, or from 90 to 97 wt%, based on the weight of the curable composition.

[0059] HALS

[0060] The curable composition of the present invention further comprises a hindered amine light stabilizer (also referred to as HALS). The curable composition may comprise a mixture of HALS.

[0061] The HALS of the curable compositions described herein can be used to provide an antimicrobial covering on a substrate via curing of the composition followed by conversion of the HALS to an N-halo-hindered amine (halamine).

[0062] Conventional technology has focused on the use of halamines as monomers that can be pre-reacted onto polymers, rather than the use of HALS as "non-reactive" additives. In exemplary embodiments, the HALS used in the present invention is an established additive in photocurable resins for improving weatherability and UV degradation. However, for purposes of the present invention, the HALS is not pre-reacted with the curable composition prior to polymerization, and the halamine is formed during the halogenation step after curing has occurred.

[0063] The HALS may be any suitable secondary hindered amine compound (i.e., a hindered amine compound having a hydrogen atom bonded to the nitrogen atom of the amine group). As utilized herein, the term "hindered amine" refers to a compound or moiety in which a carbon atom adjacent to the nitrogen atom of the amine group has no hydrogen atom directly attached thereto. Accordingly, the HALS has at least one nitrogen atom bonded to one hydrogen atom and two carbon atoms, and the carbon atom has no hydrogen atom directly attached thereto. Preferably, the carbon atom adjacent to the nitrogen atom of the hindered amine compound or moiety is not a carbonyl carbon (i.e., a carbon atom having an oxygen atom double bonded thereto).

[0064] The halamine may be a hindered amine as defined above, wherein the amine group is substituted by a halogen atom, in particular a chlorine, bromine or iodine atom. The halamine may be obtained by replacing a hydrogen atom attached to the amine group of the HALS with a halogen atom, for example by a halogenation reaction.

[0065] HALS and halamines can have any suitable molecular weight. Typically, HALS and halamines have a molecular weight of about 2,500 atomic mass units or less, preferably about 2,000 atomic mass units or less, or about 1,000 atomic mass units or less, or about 500 atomic mass units or less.

[0066] In the curable composition of the present invention (i.e. before the curing step), the HALS and the halamine are preferably not in polymerized form, i.e. they do not contain a plurality of repeating units derived from the polymerization of a HALS or halamine containing polymerizable carbon-carbon double bonds. More preferably, the HALS and the halamine each contain a single hindered amine moiety per molecule.

[0067] In one exemplary embodiment, the HALS contains functional groups that cause the HALS to react during the curing process. In another exemplary embodiment, the HALS does not contain functional groups that cause the HALS to crosslink during the curing process.

[0068] In one exemplary embodiment, the HALS may be added to a monomer, oligomer, or a combination of both, and the resulting composition is then shipped off-site for curing to provide an antimicrobial resin, such as an antimicrobial resin for a covering.

[0069] Suitable HALS include, but are not limited to, the hindered amines disclosed in WO2007 / 050245, which is incorporated by reference in its entirety. An exemplary chemical structure of the hindered amines disclosed in WO2007 / 050245 is shown below:

[0070]

[0071]

[0072] Wherein: R1, R2, R3 and R4 are independently selected from C1-C4 alkyl groups; R5 is selected from hydrogen atoms, alkyl groups, alkylamino groups, cyclic amine groups, amide groups, cyclic amide groups, isocyanate groups, hydroxyl groups, ether groups, ester groups, and combinations thereof; R6 and R7 are independently selected from hydrogen atoms, alkyl groups, aryl groups, amine groups, amide groups, and combinations thereof; R9, R 11 , R 12 and R 14 independently selected from C1-C4 alkyl groups; R 10 and R 13 is independently selected from an alkyl group, an aryl group, an amine group, an amide group, and combinations thereof; R 15 and R 16 independently selected from C1-C4 alkyl groups; R 17 is selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, an amine group, an amide group, and combinations thereof; R 18 , R 19 , R 20 and R 21 independently selected from C1-C4 alkyl groups; R 22 is selected from a hydrogen atom, an alkyl group, an aryl group, an amine group, an amide group; R 44 C 11 -C 20 An alkyl group; X is a hydrogen atom.

[0073] In various exemplary embodiments, suitable HALS include, but are not limited to, 2,2,6,6-tetramethylpiperidine; 4-chloro-2,2,6,6-tetramethylpiperidine; 4-bromo-2,2,6,6-tetramethylpiperidine; 2,2,6,6-tetramethylpiperidin-4-ol; 4-isocyanato-2,2,6,6-tetramethylpiperidine; N-butyl-2,2,6,6-tetramethylpiperidin-4-amine; 4,4-bis[(tert-butyl)dioxy]-2,2,6,6-tetramethylpiperidine; N,N-bis-(2,2,6,6-tetramethyl-piperidin-4-yl)-propane-1,3-diamine; N,N-bis-(2,2,6,6-tetramethyl-piperidin-4-yl)-hexane-1,6-diamine; N 1-(2,2,6,6-tetramethyl-piperidin-4-yl)-hexane-1,6-diamine; 2,2,6,6-tetramethylpiperidin-4-yl benzoate; bis(2,2,6,6-tetramethyl-4-piperidinyl)succinate; 3-dodecyl-1-(2,2,6,6-tetramethyl-piperidin-4-yl)-pyrrolidine-2,5-dione; 1,5-dioxa-spiro[5.5]undecane-3,3-dicarboxylic acid bis(2,2,6,6-tetramethyl-piperidin-4-yl) ester ; 2,6-Bis-(2,2,6,6-tetramethyl-piperidin-4-yl)-hexahydro-2,3a,4a,6,7a,8a-hexaaza-cyclopenta[difluoro-4,8-dione; N,N'-Bis(2,2,6,6-tetramethylpiperidin-4-yl)-N,N'-diformyl-1,6-diaminohexane; 2,2,6,6-tetramethyl-4-piperidin-4-ylcarboxylic acid-1,4-cyclohexanediylbis(methylene)ester; 2,2,6,6-tetramethylpiperidin-4-ylmethacrylic acid ester; methyl-[3-(2,2,6,6-tetramethyl-piperidin-4-yloxy)-propyl]-silanediol; N-(2,2,6,6-tetramethyl-piperidin-4-yl) stearamide; bis(2,2,6,6-tetramethyl-piperidin-4-yl) sebacate; bis(1,2,2,6,6-pentamethyl-piperidin-4-yl) sebacate; methyl-1,2,2,6,6-pentamethyl-piperidin-4-yl sebacate; 4-hydroxy-2,2,6,6-tetramethyl-piperidin-4-yl 4-piperidin-4-yl heptadecanoic acid; 2,2,6,6-tetramethyl-piperidin-4-yl ester; N,N'-1,6-hexanediylbis[N-(2,2,6,6-tetramethyl-piperidin-4-yl)-carboxamide; N,N'-bis(1,1,3,3-tetramethylbutyl)-2,9,15,22-tetrakis(2,2,6,6-tetramethyl-piperidin-4-yl)-2,9,11,13,15,22,24,26,27,28-decaazatricyclo[21.3.1.1 10,14 ]octacosyl-1(27),10,12,14(28),23,25-hexaene-12,25-diamine; poly[(6-morpholine-s-triazine-2,4-diyl)[(2,2,6,6-tetramethyl-piperidin-4-yl)imino]-hexamethylene[(2,2,6,6-tetramethyl-piperidin-4-yl)imino)]]; UV-3853; poly[(6-morpholine-s-triazine-2,4-diyl)[(2,2,6,6-tetramethyl-piperidin-4-yl)imino]-hexamethylene[(2,2,6,6-tetramethyl-piperidin-4-yl)imino)]]; N-phenylnaphthalene-1-amine; N-phenylnaphthalene-2-amine; bis-[4-(1-phenyl-ethyl)-phenyl]-amine; N-(1,3-dimethylbutyl)-N'-phenylbenzene-1,4-diamine; 4-methylphenyl(4-anilinophenyl)amide sulfite; 2,2-dimethyl-1,2-dihydroquinoline, 2,2,4-trimethyl-1,2-dihydroquinoline, 2,2,3,3-tetramethyl-1,2,3,4-tetrahydroquinoline, 2,2,3,3,4-pentamethyl-1,2,3,4-tetrahydroquinoline; and combinations thereof.

[0074] Preferred HALS are sold by BASF 770 (bis(2,2,6,6,-tetramethyl-4-piperidinyl) sebacate).

[0075] In an exemplary embodiment, the HALS is present in the curable composition in an amount such that when the HALS is converted to an N-halogeno-hindered amine by treatment with a halogenating agent, such as by treatment with a chlorinating agent to an N-chloro-hindered amine (NCHA), or such as by treatment with a brominating agent to an N-bromo-hindered amine, or such as by treatment with an iodinating agent to an N-iodo-hindered amine, the cured resin composition exhibits antimicrobial properties. In an exemplary embodiment, the halogenating agent is an aqueous solution of a hypohalite (e.g., an aqueous solution containing a hypochlorite such as sodium hypochlorite containing from about 0.001 wt % to about 1 wt % hypochlorite) or other dilute oxidative halogenated solution.

[0076] In exemplary embodiments, the total amount of HALS in the curable composition is at least 3 wt%, specifically at least 4 wt%, at least 5 wt%, at least 6 wt%, at least 7 wt%, or at least 8 wt%, based on the total weight of the curable composition. In exemplary embodiments, the total amount of HALS in the curable composition is from 3 to 30 wt. %, in particular from 3 to 25 wt. %, from 3 to 20 wt. %, from 3 to 15 wt. %, from 3 to 10 wt. %, from 4 to 30 wt. %, from 4 to 25 wt. %, from 4 to 20 wt. %, from 4 to 15 wt. %, from 4 to 10 wt. %, from 5 to 30 wt. %, from 5 to 25 wt. %, from 5 to 20 wt. %, from 5 to 15 wt. %, from 5 to 10 wt. %, from 6 to 30 wt. %, from 6 to 25 wt. %, from 6 to 20 wt. %, from 6 to 15 wt. %, from 6 to 10 wt. %, from 7 to 30 wt. %, from 7 to 25 wt. %, from 7 to 20 wt. %, from 7 to 15 wt. %, or from 7 to 10 wt. %, based on the total weight of the curable composition.

[0077] In embodiments of the present invention, the HALS may be capable of forming covalent bonds within the cured composition (in other words, the HALS may be capable of reacting with the (meth)acrylate functionalized compound during curing of the composition). In particular, the HALS may be an ethylenically unsaturated HALS.

[0078] In another embodiment, the HALS may not be capable of forming covalent bonds within the cured composition (in other words, the HALS may not be capable of reacting with the (meth)acrylate functionalized compound during curing of the composition). In particular, the HALS may be a non-ethylenically unsaturated HALS.

[0079] In an embodiment of the present invention, the HALS is capable of forming covalent bonds within the cured composition, and the total amount of HALS in the curable composition is from 10 to 30 wt%, from 12.5 to 30 wt%, from 15 to 30 wt%, or from 20 to 30 wt%, based on the total weight of the curable composition. In another embodiment, the HALS is not capable of forming covalent bonds within the cured composition, and the total amount of HALS in the curable composition is from 3 to 15 wt%, from 3 to 12 wt%, from 3 to 10 wt%, or from 4 to 10 wt%, based on the total weight of the curable composition. In another embodiment, the HALS is not capable of forming covalent bonds within the cured composition, and the total amount of HALS in the curable composition is from 6 to 15 wt%, from 6 to 12 wt%, or from 6 to 10 wt%, based on the total weight of the curable composition.

[0080] In embodiments of the present invention, the HALS may be capable of crosslinking into the cured composition. In particular, the HALS may be a multi-ethylenically unsaturated HALS, i.e. a HALS comprising more than one ethylenically unsaturated functional group such as vinyl, allyl and (meth)acrylate. More particularly, the HALS may be a multi-(meth)acrylate containing HALS.

[0081] The total amount of multi-(meth)acrylate-containing HALS in the curable composition may be at least 10 wt %, in particular from 10 to 30 wt %, from 12.5 to 30 wt %, from 15 to 30 wt %, or from 20 to 30 wt %, based on the total weight of the curable composition.

[0082] In embodiments of the present invention, the HALS may be capable of forming covalent bonds within the cured composition, preferably without crosslinking into the cured composition. For example, the coating may be crosslinked but not by the HALS compound, which only reacts in the coating and becomes part of the coating. In particular, the HALS may be a monoethylenically unsaturated HALS, i.e. a HALS comprising a single ethylenically unsaturated functional group such as vinyl, allyl and (meth)acrylate. More particularly, the HALS may be a HALS containing a mono(meth)acrylate. An example of a suitable HALS containing a mono(meth)acrylate is 2,2,6,6-tetramethyl-4-piperidinyl (meth)acrylate. Even more particularly, the HALS containing a mono(meth)acrylate is 2,2,6,6-tetramethyl-4-piperidinyl methacrylate.

[0083] The total amount of mono(meth)acrylate-containing HALS in the curable composition may be at least 10 wt %, in particular from 10 to 30 wt %, from 12.5 to 30 wt %, from 15 to 30 wt %, or from 20 to 30 wt %, based on the total weight of the curable composition.

[0084] In embodiments of the present invention, the HALS may not be able to form covalent bonds within the cured composition. In particular, the HALS may be a non-ethylenically unsaturated HALS, i.e., a HALS that does not contain any ethylenically unsaturated functional groups such as vinyl, allyl, and (meth)acrylate. More particularly, the non-ethylenically unsaturated HALS may be bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate.

[0085] The total amount of non-ethylenically unsaturated HALS in the curable composition may be at least 3 wt%, specifically from 3 to 15 wt%, from 3 to 12 wt%, from 3 to 10 wt%, or from 4 to 10 wt%, based on the total weight of the curable composition.

[0086] additive

[0087] The curable composition may further comprise one or more additives, including but not limited to photoinitiators, antioxidants, ultraviolet absorbers, light stabilizers, foam inhibitors, solvents, flow agents or leveling agents, colorants, adhesion promoters, pigments, dispersants (wetting agents), slip additives, fillers, thixotropic agents, matting agents, thermoplastics such as acrylic resins that do not contain any free radical polymerizable functional groups, waxes or other various additives, including any additives conventionally utilized in the fields of coatings, sealants, adhesives, molding or inks.

[0088] In certain embodiments of the present invention, the curable compositions described herein include at least one photoinitiator. A photoinitiator can be considered to be any type of substance that, when exposed to radiation (e.g., actinic radiation), forms a substance that initiates the reaction and curing of the polymeric organic substances present in the curable composition.

[0089] Free radical polymerization initiators are substances that form free radicals when exposed to radiation. The use of free radical photoinitiators is particularly preferred. Non-limiting types of free radical photoinitiators suitable for use in the curable composition of the present invention include, for example, benzoin, benzoin ethers, acetophenones, benzyl, benzyl ketals, anthraquinones, phosphine oxides, α-hydroxy ketones, phenylglyoxylic acid esters, α-aminoketones, benzophenones, thioxanthones, xanthone, acridine derivatives, phenazine derivatives, quinoxaline derivatives and triazine compounds.

[0090] Suitable photoinitiators include those that are capable of generating free radicals upon exposure to desired radiation, such as UV energy. In an exemplary embodiment, the photoinitiator includes an acylphosphine oxide (e.g., 819, TPO and TPO-L); benzil ketal (e.g., Irgacure 651); α-hydroxyphenyl ketone, e.g., Irgacure 184 or Darocur 173) or a mixture thereof.

[0091] The amount of the photoinitiator may be appropriately varied depending on other factors such as the selected photoinitiator(s), the amount and type of polymerizable material present in the curable composition, the radiation source used and the radiation conditions, etc. However, typically, the amount of the photoinitiator may be from 0.05 wt % to 5 wt %, preferably 0.1 wt % to 2 wt %, based on the total weight of the curable composition.

[0092] Suitable solvents are any solvents that will dissolve all other components in the curable 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 composition of the present invention may be formulated to be solvent-free, i.e., free of any non-reactive volatile materials (materials having a boiling point of 150° C. or less at atmospheric pressure). For example, the curable composition of the present invention may contain little or no non-reactive solvent, such as less than 10%, or less than 5%, or less than 1%, or even 0% of non-reactive solvent, based on the total weight of the curable composition.

[0093] Suitable adhesion promoters include silanes, titanates, zirconates and polyolefins.

[0094] Suitable wetting agents include alkoxylated surfactants, silicone surfactants, sulfonated succinates and fluorinated polyacrylates.

[0095] Suitable UV absorbers include benzophenones (such as benzophenone and hydroxybenzophenone), benzotriazoles (such as hydroxyphenylbenzotriazole), hydroxyphenyltriazines (such as oxanilide), and thioxanthones.

[0096] In general, if the curable compositions of the present invention are to be stored for a long period of time before use, it is desirable to include one or more stabilizers to provide adequate storage stability and shelf life. As used herein, the term "stabilizer" refers to a compound or substance that retards or prevents the reaction or curing of (meth)acrylate functional groups present in the composition in the absence of actinic radiation. However, it will be advantageous to select an amount and type of stabilizer so that the composition remains capable of being cured when exposed to actinic radiation (i.e., the stabilizer does not prevent radiation curing of the composition). Typically, effective stabilizers for the purposes of the present invention will be classified as free radical stabilizers (i.e., stabilizers that function by inhibiting free radical reactions).

[0097] Any stabilizer known in the art involving compounds functionalized with (meth)acrylates may be utilized in the present invention. Quinones represent a particularly preferred type of stabilizer that may be employed in the context of the present invention. As used herein, the term "quinone" includes both quinone and hydroquinone as well as ethers thereof such as monoalkyl, monoaryl, monoaralkyl and bis(hydroxyalkyl) ethers of hydroquinone. Hydroquinone monomethyl ether is an example of a suitable stabilizer that may be utilized.

[0098] The concentration of the stabilizer in the curable composition will vary depending on the particular stabilizer or combination of stabilizers selected for use, and the degree of stabilization desired and the susceptibility of the components of the curable composition to degradation in the absence of the stabilizer. Typically, however, the curable composition is formulated to contain from 50 to 5000 ppm of the stabilizer.

[0099] Method for protecting the surface of a substrate

[0100] The present invention relates to a method for protecting the surface of a substrate. The method of the present invention comprises an application step, a curing step and a halogenation step as described below. The method of the present invention may further comprise an optional step of removing any residual halogenating agent.

[0101] In an embodiment of the present invention, the applying step, the curing step, and the halogenating step may be repeated such that the substrate contains two or more layers of the cured composition.

[0102] The method of the present invention can be used to provide a protective covering on the surface of a substrate. The protective covering can advantageously exhibit one or more (or two or more, or three or more, or four or more) of the following properties: resistance to microorganisms (in other words antimicrobial), light resistance, heat resistance, impact resistance, scratch resistance and chemical resistance. Preferably, the protective covering is a microorganism-resistant (or antimicrobial) protective covering.

[0103] The protective covering may be a transparent covering.

[0104] The protective cover may have a thickness in the range of 5 to 250 μm, such as 5 to 225 μm, such as 5 to 200 μm, such as 5 to 175 μm, such as 5 to 150 μm.

[0105] Application steps

[0106] The method of the present invention comprises the step of applying a curable composition as described above to the surface of a substrate.

[0107] The curable composition can be applied to the substrate surface in any known conventional manner, for example by spraying, by brush, by sponge, by knife coating, by roller coating, by casting, by drum coating, by dipping, by shower coating, by screen printing, or by other methods of image transfer, by coating transfer, etc. and combinations thereof. Indirect application using a transfer process can also be employed.

[0108] In an embodiment, the curable composition can be applied directly to a substrate or one or more of a primer, basecoat system or other suitable layer to achieve the desired final appearance and properties. For example, the curable composition can be applied to a waterborne basecoat or a solventborne basecoat. Preferably, the curable composition is not grafted onto the substrate (i.e., there is no covalent bond or ionic bond between the substrate and the curable composition). Accordingly, the substrate does not need to be pre-treated to produce grafting sites before the curable composition is applied to the substrate.

[0109] The substrate may be any commercially available 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 may comprise one or more of metal, paper, paperboard, cardboard, glass, plastic (e.g., thermoplastics such as polyolefins, polycarbonates, acrylonitrile butadiene styrene (ABS), and blends thereof), composites, wood, leather, carbon fiber glass, non-textiles, ceramics (e.g., granite, marble), colored coverings, concrete, and combinations thereof. Preferably, the substrate comprises one or more of metal, paper, paperboard, cardboard, glass, plastic (e.g., thermoplastics such as polyolefins, polycarbonates, acrylonitrile butadiene styrene (ABS), and blends thereof), composites, wood, leather, carbon fiber glass, ceramics (e.g., granite, marble), colored coverings, concrete, and combinations thereof. More preferably, the substrate comprises one or more of metal, glass, plastic (e.g., thermoplastics such as polyolefins, polycarbonates, acrylonitrile butadiene styrene (ABS), and blends thereof), composites, carbon fiber glass, ceramic (e.g., granite, marble), a pigmented covering, concrete, and combinations thereof. Even more preferably, the substrate is a non-cellulosic substrate.

[0110] In embodiments of the invention, the curable composition may be applied to the surface of the substrate to provide a dry film thickness in the range of 5 to 250 μm, such as 5 to 225 μm, such as 5 to 200 μm, such as 5 to 175 μm, such as 5 to 150 μm.

[0111] Curing steps

[0112] The method of the present invention comprises the step of curing the curable composition as described above to provide a cured composition.

[0113] The curing of the curable composition according to the present invention can be carried out by any suitable method such as free radical polymerization, cationic polymerization and / or anionic polymerization, preferably free radical polymerization. One or more initiators such as free radical initiators (e.g., photoinitiators or peroxide initiators) may be present in the curable composition.

[0114] Curing can be accelerated or promoted by supplying energy to the curable composition, such as by exposing the composition to a radiation source such as visible light, UV energy and / or an electron beam. Thus, the cured composition can be considered to be the reaction product of the curable composition formed by curing.

[0115] The curing step of the method of the present invention may include one of the following: (1) exposing the curable composition to UV energy and / or visible light; (2) exposing the curable composition to an electron beam, (3) initiating polymerization by using radicals generated by redox; (4) initiating polymerization by using radicals generated thermally, or a combination thereof. Preferably, the curing step of the method of the present invention includes one of the following: (1) exposing the curable composition to UV energy and / or visible light; or (2) exposing the curable composition to an electron beam.

[0116] The curable compositions of the present invention are particularly well suited for curing using LED (light emitting diode) curing (eg UV LED curing, using radiation from a UV LED device) and for high speed applications such as mulch.

[0117] Multiple layers of the composition according to the invention may be applied to a substrate surface; the multiple layers may be cured simultaneously (eg by exposure to a single dose of radiation) or each layer may be cured sequentially prior to application of additional layers of the composition.

[0118] The curable composition can be cured by exposing the composition to actinic radiation, particularly UV energy and / or visible light.

[0119] In particular, the curable composition can be cured by exposing the curable composition to UV energy. The UV energy can be in the range of 200 to 400 nm. The UV energy can be provided by one or more UV lamps that generate 0.01 to 10 W / cm 2 Such as 1 to 10W / cm 2 The radiation level lasts for a time between 1 second and 30 minutes, such as between 1 second and 10 minutes.

[0120] More specifically, the curable composition can be cured by exposing the curable composition to UVC energy, UVB energy, UVA energy and / or visible light. In an exemplary embodiment, the curable composition is cured by utilizing UV energy of UVA / UVB energy or only UVA energy and substantially without involving UVC energy. In an exemplary embodiment, the curable composition is cured by a range of from 0.01 to 10 W / cm 2 The curable composition can be cured by high energy radiation. Possible light sources include, but are not limited to, natural outdoor light, black light, fluorescent lamp, LED, or high pressure mercury lamp.

[0121] The curable composition may be cured by exposing the curable composition to an electron beam. In one embodiment, the electron beam may be provided by an E-BEAM Services device that produces 2 Mrads of energy.

[0122] The curable composition may be cured by free radical polymerization.

[0123] In particular, the curable composition can be cured by initiating polymerization through the use of groups generated in a thermal manner (also referred to as thermal curing). For example, the curable composition may include a free radical initiator, such as a peroxide initiator, which is activated by heating. Examples of suitable peroxide initiators include, but are not limited to, hydrogen peroxide, benzoyl peroxide, or tert-butyl hydroperoxide.

[0124] Alternatively, the curable composition can be cured by initiating polymerization through the use of redox generated groups (also referred to as two-step redox curing). For example, the curable composition can include a free radical initiator (such as a peroxide as described above) and a reducing agent (e.g., a tertiary amine such as N,N-dimethylaniline, N-(4-methoxyphenyl)pyrrolidine, and N-phenyldiethanolamine, sodium sulfite, sodium metabisulfite). The free radical initiator can be activated by a reducing agent.

[0125] Preferably, the curable composition is not cured by thermal curing.

[0126] In an embodiment of the invention, the cured composition is present as a covering either alone or as a component in a coating composition on a substrate having a thickness in the range of 5 to 250 μm, such as 5 to 225 μm, such as 5 to 200 μm, such as 5 to 175 μm, such as 5 to 150 μm.

[0127] In an embodiment of the present invention, the cured composition is a transparent covering on the surface of the substrate.

[0128] Halogenation step

[0129] The process of the present invention comprises the step of treating the cured composition as defined above with a halogenating agent in order to halogenate the HALS present in the cured composition.

[0130] Halogenation of HALS results in the formation of N-halo-hindered amines (halamines) in the cured composition. The presence of haloamines in the cured composition can advantageously impart antimicrobial properties to the cured composition.

[0131] Two methods can typically be used to generate halamines from HALS: halogenating the HALS before incorporating it into the curable composition, or halogenating the HALS present in the cured composition (in other words, the HALS is present in the curable composition prior to curing).

[0132] In the method of the present invention, the HALS is present in the cured composition, and the halogenation can be carried out by any suitable means, such as by spraying, immersing, or wiping the surface of the cured composition with the halogenating agent (optionally in the form of a desired dilution). In the method of the present invention, the HALS is preferably not halogenated before it is introduced into the curable composition.

[0133] Suitable halogenating agents include, but are not limited to, chlorinating agents such as hypochlorites (e.g., calcium hypochlorite, lithium hypochlorite, and sodium hypochlorite), trichloroisocyanuric acid and dichloroisocyanurates (e.g., potassium dichloroisocyanurate and sodium dichloroisocyanurate), and iodinating agents such as povidone iodine. In embodiments, the halogenating agent is used in a stoichiometric excess as measured by the amount of HALS present in the curable composition, such as at least 10% molar excess, at least 30% molar excess, at least 50% molar excess, at least 100% molar excess, or at least 200% molar excess.

[0134] In an embodiment of the present invention, the halogenating agent is a chlorinating agent, in particular sodium hypochlorite, more particularly a sodium hypochlorite solution (also conventionally referred to as bleach), even more particularly a 5.25-8.25% w / w sodium hypochlorite aqueous solution, which can be prepared by Commercially available.

[0135] In embodiments of the invention, the sodium hypochlorite is further diluted from its original commercial form, such as by adding water. In embodiments, the sodium hypochlorite is present as a household bleach (5.25-8.25% w / w sodium hypochlorite in water) which has been diluted with at least 10% water, such as with at least 20% water, such as with at least 30% water, such as with at least 40% water, such as with at least 50% water.

[0136] In another embodiment, the halogenating agent is an iodinating agent such as (Povidone-iodine).

[0137] In an exemplary embodiment, after treating the composition with a halogenating agent, the method may include an optional step of removing any residual halogenating agent. For example, the cured composition may be contacted with water either directly (e.g., sprayed) or indirectly (e.g., wiped with a wet cloth or sponge) in an amount sufficient to remove any residual halogenating agent.

[0138] In an exemplary embodiment, after treating the composition with a halogenating agent, a zinc iodide (ZnI) / starch indicator is used to detect the presence of halamines in the cured composition. In an exemplary embodiment, a cotton swab is saturated with the ZnI / starch indicator and wiped on the treated surface. The solution on the swab changes from transparent to dark blue / purple in the presence of chlorine. Other methods of detection of halamines known in the art, such as detection by titration techniques, are also suitable.

[0139] A wide variety of hindered amines can be evaluated for their antimicrobial activity and the concentrations required to promote said activity. 10 The data is used to characterize the antimicrobial properties of cured compositions containing halamines and to identify compositions suitable for antimicrobial applications. In an exemplary embodiment, JIS Z 2801:2010 is used to quantify the Log 10 Reduction. In embodiments, at least a 1,000-fold reduction in the number of at least one of Staphylococcus aureus and E. Coli (ie, a 3 log-10 reduction) is observed.

[0140] In an embodiment of the present invention, depending on the application, the substrate surface is treated with a halogenating agent periodically as needed (such as once or more per day, or once a week, or once a month or once every two months) to restore and / or enhance the antimicrobial activity of the surface on which the cured composition is present.

[0141] In embodiments of the present invention, the surface of a substrate comprising the cured composition exhibits substantially improved antimicrobial properties compared to the surface of a substrate coated with the same curable composition without the HALS.

[0142] In an embodiment of the invention, after the step of treating the cured composition with a halogenating agent, the surface of the substrate retains greater than 50% of its antimicrobial properties (based on the concentration of the remaining halogen in the covering present as halogenated HALS) for up to 3 weeks, or up to 4 weeks, or up to 5 weeks, or up to 6 weeks.

[0143] Other methods, compositions and uses

[0144] The present invention also relates to a method of treating a cured composition with a halogenating agent to halogenate a HALS present in the cured composition, wherein the cured composition comprises the cured product of a curable composition comprising a HALS and a (meth)acrylate functionalized compound. The curable composition may be as defined above.

[0145] The present invention relates to a cured composition comprising an N-halo-hindered amine, wherein the cured composition is obtained by: (a) curing a curable composition as defined above; and (b) then converting the HALS into an N-halo-hindered amine by treating the HALS with a halogenating agent.

[0146] The present invention also relates to the use of at least one HALS, at least one (meth)acrylate functionalized compound, and at least one halogenating agent for obtaining an antimicrobial covering on the surface of a substrate. The antimicrobial properties of the covering can be determined according to JIS Z 2801:2010 as detailed above. For example, the antimicrobial covering can show at least a 1,000-fold reduction in the number of at least one Staphylococcus aureus and Escherichia coli (E. Coli) compared to a covering that does not contain any HALS or halamine (i.e., a 3 log-10 reduction).

[0147] Aspects of the Invention

[0148] Exemplary, non-limiting embodiments of the present invention can be summarized as follows:

[0149] Aspect 1: A method for protecting a surface of a substrate, the method comprising:

[0150] - applying a curable composition comprising a (meth)acrylate-functional compound and a hindered amine light stabilizer (HALS) onto the surface of the substrate;

[0151] - curing the curable composition to provide a cured composition;

[0152] - treating the cured composition with a halogenating agent to halogenate the HALS present in the cured composition; and

[0153] - Optionally removing any residual halogenating agent.

[0154] Aspect 2: The method according to aspect 1, wherein the cured composition treated with the halogenating agent provides a protective covering on the surface of the substrate.

[0155] Aspect 3: A method according to Aspect 2, wherein the protective covering exhibits one or more (or two or more, or three or more, or four or more) of the following properties: resistance to microorganisms, light resistance, heat resistance, impact resistance, scratch resistance and chemical resistance; preferably, the protective covering is a microorganism-resistant (or antimicrobial) protective covering.

[0156] Aspect 4: The method according to aspect 2 or 3, wherein the protective cover is a transparent cover.

[0157] Aspect 5: The method according to any of aspects 2-4, wherein the protective cover has a thickness in the range of 5 to 250 μm, such as 5 to 225 μm, such as 5 to 200 μm, such as 5 to 175 μm, such as 5 to 150 μm.

[0158] Aspect 6: A method according to any one of Aspects 1-5, wherein curing comprises one of the following: (1) exposing the curable composition to UV energy and / or visible light; (2) exposing the curable composition to an electron beam, (3) initiating polymerization by using radicals generated by redox; or (4) initiating polymerization by using radicals generated thermally.

[0159] Aspect 7: The method according to any one of aspects 1-6, wherein the curable composition is cured by exposing the curable composition to UV energy.

[0160] Aspect 8: The method according to any one of aspects 1 to 7, wherein the curable composition is cured by exposing the curable composition to visible light.

[0161] Aspect 9: The method according to any one of aspects 1 to 6, wherein the curable composition is cured by exposing the curable composition to an electron beam.

[0162] Aspect 10: The method according to any one of aspects 1 to 6, wherein the curable composition is cured by initiating polymerization using redox generated groups.

[0163] Aspect 11: The method according to any one of aspects 1 to 6, wherein the curable composition is cured by initiating polymerization using thermally generated radicals.

[0164] Aspect 12: The method according to any one of aspects 1 to 10, wherein the curable composition is cured without initiating polymerization using thermally generated radicals.

[0165] Aspect 13: The method according to any one of aspects 1 to 12, wherein the halogenating agent is selected from chlorinating agents such as hypochlorites (e.g., calcium hypochlorite, lithium hypochlorite, and sodium hypochlorite), trichloroisocyanuric acid and dichloroisocyanurates (e.g., potassium dichloroisocyanurate and sodium dichloroisocyanurate), and iodinating agents such as povidone iodine.

[0166] Aspect 14: The method according to any one of aspects 1 to 13, wherein the halogenating agent is a chlorinating agent, in particular sodium hypochlorite, more particularly a sodium hypochlorite solution.

[0167] Aspect 15: The method according to any of aspects 1-14, wherein the HALS has at least one nitrogen atom bonded to one hydrogen atom and two carbon atoms, wherein the carbon atoms have no hydrogen atoms directly attached thereto.

[0168] Aspect 16: The method according to any one of aspects 1-15, wherein the HALS has at least one nitrogen atom bonded to one hydrogen atom and two carbon atoms, wherein the carbon atoms are not carbonyl carbons.

[0169] Aspect 17: The method of any of aspects 1-16, wherein the curable composition comprises a HALS that can be crosslinked into the cured composition.

[0170] Aspect 18: The method of any of aspects 1-16, wherein the curable composition comprises a HALS capable of forming covalent bonds within the cured composition, preferably without crosslinking into the cured composition.

[0171] Aspect 19: The method according to aspect 18, wherein the HALS is an ethylenically unsaturated HALS, in particular 2,2,6,6-tetramethyl-4-piperidinyl (meth)acrylate.

[0172] Aspect 20: The method of any of aspects 1-16, wherein the curable composition comprises a HALS that is incapable of forming covalent bonds within the cured composition.

[0173] Aspect 21: The method according to aspect 20, wherein the HALS is a non-ethylenically unsaturated HALS, in particular bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate.

[0174] Aspect 22: The method according to any one of aspects 1 to 21, wherein the total amount of HALS in the curable composition is at least 3 wt%, particularly from 3 to 30 wt%, from 3 to 25 wt%, from 3 to 20 wt%, from 3 to 15 wt%, from 3 to 10 wt%, from 4 to 30 wt%, from 4 to 25 wt%, from 4 to 20 wt%, from 4 to 15 wt%, from 4 to 10 wt%, from 5 to 30 wt%, from 5 to 25 wt%, from 5 to 20 wt%, from 5 to 15 wt%, from 5 to 10 wt%, from 6 to 30 wt%, from 6 to 25 wt%, from 6 to 20 wt%, from 6 to 15 wt%, from 6 to 10 wt%, from 7 to 30 wt%, from 7 to 25 wt%, from 7 to 20 wt%, from 7 to 15 wt%, or from 7 to 10 wt%, based on the total weight of the composition.

[0175] Aspect 23: The method according to any one of Aspects 1-16, wherein the curable composition comprises a HALS capable of forming covalent bonds within the cured composition, and the total amount of HALS in the curable composition is from 10 to 30 wt%, in particular from 12.5 to 30 wt%, from 15 to 30 wt%, or from 20 to 30 wt%, based on the total weight of the curable composition.

[0176] Aspect 24: The method according to any one of Aspects 1-16, wherein the curable composition comprises a HALS that is not capable of forming covalent bonds within the cured composition, and the total amount of HALS in the curable composition is from 3 to 15 wt %, in particular from 3 to 12 wt %, from 3 to 10 wt %, or from 4 to 10 wt %, based on the total weight of the curable composition.

[0177] Aspect 25: A method according to any one of Aspects 1-16, wherein the curable composition comprises a HALS that is not capable of forming covalent bonds within the cured composition, and the total amount of HALS in the curable composition is from 6 to 15 wt %, in particular from 6 to 12 wt %, or from 6 to 10 wt %, based on the total weight of the curable composition.

[0178] Aspect 26: The method of any of aspects 1-25, wherein the curable composition comprises a (meth)acrylate-functionalized monomer.

[0179] Aspect 27: The method of aspect 26, wherein the (meth)acrylate-functionalized monomer has 1 to 6 (meth)acrylate groups, specifically 1 to 3 (meth)acrylate groups.

[0180] Aspect 28: The method of any of aspects 1-27, wherein the curable composition comprises a mono(meth)acrylate-functionalized monomer.

[0181] Aspect 29: The method of any of aspects 1-28, wherein the curable composition comprises a (meth)acrylate-functionalized monomer comprising two or more (meth)acrylate-functional groups per molecule.

[0182] Aspect 30: The method of any of aspects 1-29, wherein the curable composition comprises a (meth)acrylate-functionalized oligomer.

[0183] Aspect 31: The method according to aspect 30, wherein the (meth)acrylate-functionalized oligomer has 1 to 18 (meth)acrylate groups, in particular 2 to 6 (meth)acrylate groups,

[0184] Aspect 32: A method according to any one of Aspects 1-31, wherein the curable composition comprises a (meth)acrylate-functionalized oligomer selected from the group consisting of: a (meth)acrylate-functionalized urethane oligomer, a (meth)acrylate-functionalized epoxy oligomer, a (meth)acrylate-functionalized polyether oligomer, a (meth)acrylate-functionalized polydiene oligomer, a (meth)acrylate-functionalized polycarbonate oligomer, a (meth)acrylate-functionalized polyester oligomer, a (meth)acrylate-functionalized (meth)acrylic oligomer, and mixtures thereof.

[0185] Aspect 33: A method according to any one of Aspects 1-32, wherein the (meth)acrylate-functionalized compound of the curable composition comprises one or more (meth)acrylate-functionalized monomers having from 1 to 6 (meth)acrylate groups per molecule, optionally in combination with one or more (meth)acrylate-functionalized oligomers containing two or more (meth)acrylate groups per molecule, wherein the (meth)acrylate-functionalized oligomer is selected from the group consisting of (meth)acrylate-functionalized urethane oligomers, (meth)acrylate-functionalized epoxy oligomers, (meth)acrylate-functionalized polyether oligomers, (meth)acrylate-functionalized polyester oligomers, and mixtures thereof.

[0186] Aspect 34: A method according to any one of Aspects 1-33, wherein the total amount of (meth)acrylate-functionalized compounds in the curable composition is from 0.1 to 97 weight %, in particular from 1 to 95 weight %, from 5 to 93 weight %, from 10 to 90 weight %, from 15 to 85 weight %, from 20 to 80 weight %, from 25 to 75 weight %, based on the weight of the curable composition.

[0187] Aspect 35: A method according to any one of Aspects 1-34, wherein the curable composition further comprises one or more additives, including but not limited to photoinitiators, antioxidants, ultraviolet absorbers, light stabilizers, foam inhibitors, solvents, flow agents or leveling agents, colorants, pigments, dispersants (wetting agents), slip additives, fillers, thixotropic agents, matting agents, thermoplastics such as acrylic resins that do not contain any free radical polymerizable functional groups, waxes or other various additives, including any additives conventionally used in the fields of coatings, sealants, adhesives, molding or inks.

[0188] Aspect 36: A method according to any of Aspects 1-35, wherein the substrate to which the curable composition is applied comprises one or more of the following: metal, paper, paperboard, cardboard, glass, plastic (e.g., thermoplastics such as polyolefins, polycarbonates, acrylonitrile butadiene styrene (ABS), and blends thereof), composites, wood, leather, carbon fiber glass, non-textiles, ceramics (e.g., granite, marble), colored coverings, concrete, and combinations thereof.

[0189] Aspect 37: The method of any of aspects 1-36, wherein the substrate surface is periodically treated with a halogenating agent to restore and / or enhance the antimicrobial resistance of the surface on which the cured composition is present.

[0190] Aspect 38: The method of any of aspects 1-37, wherein the covering, curing, and treating steps are repeated such that the substrate contains two or more layers of the cured composition.

[0191] Aspect 39: The method of any of Aspects 1-38, wherein the surface of the substrate containing the cured composition exhibits substantially improved antimicrobial properties compared to a cured composition not containing the HALS.

[0192] Aspect 40: According to any of Aspects 1-39, after the step of treating the cured composition with a chlorinating agent, the surface of the substrate retains more than 50% of its antimicrobial properties (based on the concentration of the remaining halogen in the covering present as halogenated HALS) for up to 3 weeks, or up to 4 weeks, or up to 5 weeks, or up to 6 weeks.

[0193] Aspect 41: The method according to any of aspects 1-39, wherein the antimicrobial properties of the surface of the substrate are reactivated or enhanced by periodically contacting the surface with a halogenated agent such as sodium hypochlorite or povidone-iodine.

[0194] Aspect 42: A method of treating a cured composition with a halogenating agent to halogenate a HALS present in the cured composition, wherein the cured composition comprises the cured product of a curable composition comprising a HALS and a (meth)acrylate-functionalized compound.

[0195] Aspect 43: The method according to aspect 42, wherein the halogenating agent is sodium hypochlorite or (Povidone-iodine).

[0196] Aspect 44: A curable composition comprising a (meth)acrylate functionalized compound and a HALS, wherein the total amount of HALS in the composition is at least 3 wt%, preferably at least 6 wt%, based on the weight of the composition.

[0197] Aspect 45: The curable composition of aspect 44, wherein the HALS is a hindered amine compound having a hydrogen atom bonded to a nitrogen atom of an amine group.

[0198] Aspect 46: The curable composition of aspect 44 or 45, wherein the carbon atom adjacent to the nitrogen atom of the HALS is not a carbonyl carbon.

[0199] Aspect 47: The curable composition of any one of Aspects 44 to 46, wherein the curable composition comprises a HALS that can be crosslinked into the cured composition.

[0200] Aspect 48: The curable composition of any one of Aspects 44 to 46, wherein the curable composition comprises a HALS capable of forming covalent bonds within the cured composition, preferably without crosslinking into the cured composition.

[0201] Aspect 49: The curable composition according to aspect 48, wherein the HALS is an ethylenically unsaturated HALS, in particular 2,2,6,6-tetramethyl-4-piperidinyl (meth)acrylate.

[0202] Aspect 50: The curable composition of any one of Aspects 44 to 46, wherein the curable composition comprises a HALS that is incapable of forming covalent bonds within the cured composition.

[0203] Aspect 51: The curable composition according to aspect 50, wherein the HALS is a non-ethylenically unsaturated HALS, in particular bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate.

[0204] Aspect 52: The curable composition according to any one of aspects 44-51, wherein the total amount of HALS in the curable composition is at least 3 wt%, in particular from 3 to 30 wt%, from 3 to 25 wt%, from 3 to 20 wt%, from 3 to 15 wt%, from 3 to 10 wt%, from 4 to 30 wt%, from 4 to 25 wt%, from 4 to 20 wt%, from 4 to 15 wt%, from 4 to %, from 5 to 30 wt %, from 5 to 25 wt %, from 5 to 20 wt %, from 5 to 15 wt %, from 5 to 10 wt %, from 6 to 30 wt %, from 6 to 25 wt %, from 6 to 20 wt %, from 6 to 15 wt %, from 6 to 10 wt %, from 7 to 30 wt %, from 7 to 25 wt %, from 7 to 20 wt %, from 7 to 15 wt %, or from 7 to 10 wt %, based on the total weight of the composition.

[0205] Aspect 53: A curable composition according to any one of Aspects 44 to 46, wherein the curable composition comprises a HALS capable of forming covalent bonds within the cured composition, and the total amount of HALS in the curable composition is from 10 to 30 wt %, in particular from 12.5 to 30 wt %, from 15 to 30 wt %, or from 20 to 30 wt %, based on the total weight of the curable composition.

[0206] Aspect 54: A curable composition according to any one of Aspects 44 to 46, wherein the curable composition comprises a HALS that is not capable of forming covalent bonds within the cured composition, and the total amount of HALS in the curable composition is from 3 to 15 wt %, in particular from 3 to 12 wt %, from 3 to 10 wt %, or from 4 to 10 wt %, based on the total weight of the curable composition.

[0207] Aspect 55: A curable composition according to any one of Aspects 44 to 46, wherein the curable composition comprises a HALS that is not capable of forming covalent bonds within the cured composition, and the total amount of HALS in the curable composition is from 6 to 15 wt%, in particular from 6 to 12 wt%, or from 6 to 10 wt%, based on the total weight of the curable composition.

[0208] Aspect 56: The curable composition of any of aspects 44-55, wherein the curable composition comprises a (meth)acrylate-functionalized monomer.

[0209] Aspect 57: The curable composition of aspect 56, wherein the (meth)acrylate-functionalized monomer has 1 to 6 (meth)acrylate groups, specifically 1 to 3 (meth)acrylate groups.

[0210] Aspect 58: The curable composition of any of Aspects 44-57, wherein the curable composition comprises a mono (meth)acrylate functionalized monomer.

[0211] Aspect 59: The curable composition of any of aspects 44-58, wherein the curable composition comprises a (meth)acrylate-functionalized monomer comprising two or more (meth)acrylate-functional groups per molecule.

[0212] Aspect 60: The curable composition of any of Aspects 44-59, wherein the curable composition comprises a (meth)acrylate functionalized oligomer.

[0213] Aspect 61: The curable composition according to aspect 60, wherein the (meth)acrylate functionalized oligomer has 1 to 18 (meth)acrylate groups, in particular 2 to 6 (meth)acrylate groups,

[0214] Aspect 62: A curable composition according to any one of Aspects 44-61, wherein the curable composition comprises a (meth)acrylate functionalized oligomer selected from the group consisting of: a (meth)acrylate functionalized urethane oligomer, a (meth)acrylate functionalized epoxy oligomer, a (meth)acrylate functionalized polyether oligomer, a (meth)acrylate functionalized polydiene oligomer, a (meth)acrylate functionalized polycarbonate oligomer, a (meth)acrylate functionalized polyester oligomer, a (meth)acrylate functionalized (meth)acrylate oligomer, and mixtures thereof.

[0215] Aspect 63: A curable composition according to any one of Aspects 44-62, wherein the (meth)acrylate-functionalized compound of the curable composition comprises one or more (meth)acrylate-functionalized monomers having from 1 to 6 (meth)acrylate groups per molecule, optionally in combination with one or more (meth)acrylate-functionalized oligomers having two or more (meth)acrylate groups per molecule, the (meth)acrylate-functionalized oligomers being selected from (meth)acrylate-functionalized urethane oligomers, (meth)acrylate-functionalized epoxy oligomers, (meth)acrylate-functionalized polyether oligomers, (meth)acrylate-functionalized polyester oligomers, and mixtures thereof.

[0216] Aspect 64: A curable composition according to any one of Aspects 44-63, wherein the total amount of (meth)acrylate-functionalized compounds in the curable composition is from 0.1 to 97 weight %, in particular from 1 to 95 weight %, from 5 to 93 weight %, from 10 to 90 weight %, from 15 to 85 weight %, from 20 to 80 weight %, from 25 to 75 weight %, based on the weight of the curable composition.

[0217] Aspect 65: A curable composition according to any one of Aspects 44-64, wherein the curable composition further comprises one or more additives, including but not limited to photoinitiators, antioxidants, ultraviolet absorbers, light stabilizers, foam inhibitors, solvents, flow agents or leveling agents, colorants, pigments, dispersants (wetting agents), slip additives, fillers, thixotropic agents, matting agents, thermoplastics such as acrylic resins that do not contain any free radical polymerizable functional groups, waxes or other various additives, including any additives conventionally used in the fields of coatings, sealants, adhesives, molding or inks.

[0218] Aspect 66: A cured composition comprising an N-halo-hindered amine, wherein the cured composition is obtained by: (a) curing the curable composition according to any one of Aspects 44-65; and (b) then converting the HALS into the N-halo-hindered amine by treating the cured composition with a halogenating agent.

[0219] Aspect 67: The cured composition according to aspect 66, wherein the halogenating agent is a chlorinating agent, in particular sodium hypochlorite.

[0220] Aspect 68: A cured composition according to Aspect 66 or 67, wherein curing comprises one of the following: (1) exposing the curable composition to UV energy and / or visible light; (2) exposing the curable composition to an electron beam, (3) initiating polymerization by using radicals generated by redox; or (4) initiating polymerization by using radicals generated thermally.

[0221] Aspect 69: Use of at least one HALS, at least one (meth)acrylate functionalized compound, and at least one halogenating agent for obtaining an antimicrobial covering on a surface of a substrate.

[0222] In this specification, the embodiments have been described in a manner that enables a clear and concise description to be written, but it is intended and will be understood that the embodiments can be combined or separated in various ways without departing from the present invention. For example, it will be understood that all preferred features described herein are applicable to all aspects of the invention described herein.

[0223] In some embodiments, the present invention may be interpreted herein as excluding any element or process step that does not substantially affect the basic and novel features of the compositions and methods described herein. Additionally, in some embodiments, the present invention may be interpreted as excluding any element or process step not specified herein.

[0224] Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made to the details within the scope and range of equivalents of the claims and without departing from the invention.

[0225] Example

[0226] Preparation of Cured Acrylate Compositions

[0227] The curable composition was applied to an aluminum test panel at a thickness of 1 mil and heated with a medium pressure mercury arc lamp at 500 mJ / cm 2 The cured samples were then conditioned at 72°F / 50% RH for 24 hours.

[0228] Chlorination step

[0229] The test plate covered with solidified acrylic resin was immersed in the 50 / 50 bleach / DI ​​aqueous solution for 1.5 minutes. The DI water rinse was subsequently used to continue 1.5 minutes (twice) to remove residual bleach and allow drying to continue 24 hours. The presence of halamine was confirmed by using ZnI / starch solution (Sigma-Aldrich) as the indicator on "active" surface. Cotton swab was soaked with the solution and repeatedly wiped on the treated surface. The color change from transparent to purple of the cotton swab soaked in indicated the presence of halamine.

[0230] Testing of cured resin coverings for antimicrobial activity

[0231] Example 1. The seven covered samples (1A-1H) listed in the table below were tested using the method described in JIS Z 2801:2010 (or ISO 22196:2011). The formulation of the covering contains PRO14589, which is a blend of a multifunctional urethane acrylate oligomer and an acrylate monomer with a range of functionalities that provides a good balance of flexibility and hardness. The % of HALS indicated is based on the weight of HALS compared to the total weight of the uncured formulation.

[0232]

[0233] The samples were tested against Staphylococcus aureus and Escherichia coli with a contact time of 24 hours. The table below shows the results of the testing.

[0234]

[0235] It was observed that when no HALS was present in the samples, no reduction in the levels of S. aureus or E. coli was detected, regardless of whether the samples were chlorinated (Samples 1A and 1B). Sample 1C, which was HALS, showed a significant reduction in the levels of these two microorganisms while containing 5%, 7.5% and 10% of Samples 1D, 1E and 1F with 770 as the HALS showed almost complete reduction. In contrast, Sample G containing 7.5% TEMPO methacrylate as the HALS showed slightly less reduction of S. aureus (compared to sample 1E) and significantly less reduction of E. coli (compared to sample 1E).

Claims

1. A method for protecting the surface of a substrate, the method comprising: - applying a curable composition comprising a (meth)acrylate-functional compound and a hindered amine light stabilizer (HALS) onto the surface of the substrate; - curing the curable composition to provide a cured composition; - treating the cured composition with a halogenating agent to halogenate the HALS present in the cured composition; and - Optionally removing any residual halogenating agent.

2. The method according to claim 1, wherein the curing is carried out by free radical polymerization, cationic polymerization and / or anionic polymerization, preferably by free radical polymerization.

3. The method according to claim 1, wherein the curing comprises one of the following: (1) exposing the curable composition to UV energy and / or visible light; (2) exposing the curable composition to an electron beam, (3) initiating polymerization by using radicals generated by redox; or (4) initiating polymerization by using radicals generated thermally. Preferably, the curing comprises one of the following: (1) exposing the curable composition to UV energy and / or visible light; or (2) exposing the curable composition to an electron beam.

4. The method according to any one of claims 1 to 3, wherein the halogenating agent is a chlorinating agent, in particular sodium hypochlorite, more in particular a sodium hypochlorite solution.

5. The method of any one of claims 1 to 4, wherein the HALS has at least one nitrogen atom bonded to one hydrogen atom and two carbon atoms, wherein the carbon atoms have no hydrogen atoms directly attached thereto.

6. The method according to any one of claims 1 to 5, wherein the HALS has at least one nitrogen atom bonded to one hydrogen atom and two carbon atoms, wherein the carbon atoms are not carbonyl carbons.

7. A method according to any one of claims 1 to 6, wherein the HALS is capable of forming covalent bonds within the cured composition, preferably without being crosslinked into the cured composition.

8. The method of claim 7, wherein the HALS is 2,2,6,6-tetramethyl-4-piperidinyl (meth)acrylate.

9. The method of any one of claims 1 to 6, wherein the HALS is not capable of forming covalent bonds within the cured composition.

10. The method of claim 9, wherein the HALS is bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate.

11. The method according to any one of claims 1 to 10, wherein the total amount of HALS in the curable composition is at least 3 wt.-%, based on the total weight of the composition, in particular from 3 to 30 wt.-%, from 3 to 25 wt.-%, from 3 to 20 wt.-%, from 3 to 15 wt.-%, from 3 to 10 wt.-%, from 4 to 30 wt.-%, from 4 to 25 wt.-%, from 4 to 20 wt.-%, from 4 to 15 wt.-%, from 4 to 10 wt.-%, from 5 to 30 wt.-%, from 5 to 25 wt.-%, from 5 to 20 wt.-%, from 5 to 15 wt.-%, from 5 to 10 wt.-%, based on the total weight of the composition.

12. The method of any one of claims 1 to 11, wherein the (meth)acrylate functionalized compound of the curable composition comprises one or more (meth)acrylate functionalized monomers having from 1 to 6 (meth)acrylate groups per molecule, optionally in combination with one or more (meth)acrylate functionalized oligomers containing two or more (meth)acrylate groups per molecule, the (meth)acrylate functionalized oligomers being selected from the group consisting of (meth)acrylate functionalized urethane oligomers, (meth)acrylate functionalized epoxy oligomers, (meth)acrylate functionalized polyether oligomers, (meth)acrylate functionalized polyester oligomers, and mixtures thereof.

13. The method according to any one of claims 1 to 12, wherein the total amount of (meth)acrylate-functionalized compounds in the curable composition is from 0.1 to 97 wt. %, in particular from 1 to 95 wt. %, from 5 to 93 wt. %, from 10 to 90 wt. %, from 15 to 85 wt. %, from 20 to 80 wt. %, or from 25 to 75 wt. %, based on the weight of the curable composition.

14. The method according to any one of claims 1 to 13, wherein the substrate comprises one or more of the following: metal, paper, paperboard, cardboard, glass, plastic, composite, wood, leather, carbon fiber glass, non-textile, ceramic (e.g. granite, marble), pigmented coverings, concrete, and combinations thereof, preferably one or more of the following: metal, paper, paperboard, cardboard, glass, plastic, composite, wood, leather, carbon fiber glass, ceramic (e.g. granite, marble), pigmented coverings, concrete, and combinations thereof, more preferably a non-cellulosic substrate.

15. A method of treating a cured composition with a halogenating agent to halogenate a HALS present in the cured composition, wherein the cured composition comprises the cured product of a curable composition comprising a HALS and a (meth)acrylate functionalized compound.

16. A curable composition comprising a (meth)acrylate-functional compound and a HALS, wherein the total amount of HALS in the composition is at least 3 wt%, preferably at least 6 wt%, based on the weight of the composition.

17. A cured composition comprising an N-halo-hindered amine, wherein the cured composition is obtained by: (a) curing the curable composition defined in claim 16; and (b) then converting the HALS into an N-halo-hindered amine by treating the HALS with a halogenating agent.

18. Use of at least one HALS, at least one (meth)acrylate-functionalized compound, and at least one halogenating agent for obtaining an antimicrobial covering on the surface of a substrate.

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