Antimicrobial dental varnishes based on cationic polymer dispersions

Abstract

It is an object of the present invention to provide antimicrobial dental varnishes based on cationic polymer dispersions.SOLUTION: A cationic polymer dispersion is provided which comprises at least one copolymer, water and at least one surfactant. The dispersion comprises at least one antimicrobial agent and is essentially free of low boiling organic solvents. The dispersion is suitable for antimicrobial dental varnishes or coatings.SELECTED DRAWING: None

Description

[Technical Field]

[0001] Technical Field The present invention relates to copolymer compositions that are particularly suitable as dental materials for the production of dental varnishes, lacquers or coatings. In particular, the present invention relates to anti-caries materials with antimicrobial properties. [Background technology]

[0002] background Dental varnishes containing antimicrobial compounds are used to combat plaque, caries, and periodontitis. They are typically applied to tooth surfaces by dentists, dental hygienists, or other health care professionals.

[0003] Most antimicrobial dental varnishes consist of a resin, such as a colophony or polyurethane-based resin, an antimicrobial agent, and a solvent. Solvents, such as ethanol and other alcohols, are used to keep the varnish fluid for ease of application. A common antimicrobial agent is chlorhexidine. When the varnish comes into contact with air, the solvent evaporates, allowing the varnish to adhere to the tooth surface, increasing the duration of antimicrobial activity. They can remain on the surface for several hours up to several days after application, but are not intended to remain permanently on the tooth.

[0004] U.S. Patent No. 5,213,615 A ​​discloses a dental varnish for controlling caries and periodontitis, containing a combination of thymol and / or carvacrol with chlorhexidine as the active antibacterial ingredients, and a carrier, which may be a solution of colophony in an organic solvent such as ethanol, propanol, amyl acetate, and 1,2-dichloroethylene.

[0005] German Patent Application Publication No. 102 42 476 A1 discloses a composition comprising one or more poorly water-soluble antibiotic salts, optionally a water-soluble antibiotic, and one or more excipients, suspended in a homogeneous polymer blend consisting of one or more hydrophobic, nonionic polymers selected from PVC, chlorinated PVC, poly(vinylidene chloride), poly(vinyl fluoride), poly(vinylidene fluoride), copolymers of vinyl chloride with one or more nonionic monomers, and one or more hydrophilic polymers selected from the group consisting of polyethers. The composition is suitable for coating, for example, plastic tubing and plastic bodies suitable for medical implants, and is described as releasing the antibiotic over several days in an aqueous environment.

[0006] WO 2010 / 043606A1 discloses a coating composition comprising an organic microbicidal compound, such as chlorhexidine, and a condensate of at least one hydrolyzable silicon compound containing at least one organic group that is not hydrolyzed.The composition can be used to produce a silver-free microbicidal coating, which is described as having high microbicidal activity and significantly preventing biofilm formation.To achieve anti-adhesion properties, the composition can contain fluorosilanes.

[0007] European Patent Application Publication No. 2 705 825 A1 discloses a fluoride-containing varnish for application to tooth surfaces, containing 25 to 87.5% by weight of an organic solvent, 2 to 50% by weight of water, 5 to 50% by weight of a water-insoluble film-forming agent, 0.5 to 10% by weight of a dissolved inorganic fluoride source, preferably 5 to 25% by weight of a plasticizer, and optionally an antimicrobial agent. The varnish is particularly suitable for use in treating sensitive teeth and / or the cervical area, preventing caries, treating early caries lesions, and inhibiting demineralization and / or tooth erosion. The combined use of organic solvent and water achieves good film-forming properties and fluoride release.

[0008] WO 2015 / 084315A1 is RSiO3 / 2 The present invention discloses an oral care composition comprising 30 to 90% by weight of a silsesquioxane silicone resin containing a hydroxypropyl methyl group unit and 10 to 50% by weight of a solvent, such as ethanol. The composition may further comprise an oral care active agent selected from one or more fluoride ion sources, desensitizing agents, tooth whitening agents, tooth bleaching agents, antibacterial agents, anti-tartar agents, and mixtures thereof. The composition preferably contains less than 3% by weight of water. The combination of the solvent and the silsesquioxane silicone resin is said to result in an oral care composition capable of forming a film that visually brightens tooth enamel surfaces.

[0009] DE-OS 10 2007 040 569 A1 discloses a varnish for preventing dental caries and for protecting teeth and gums, based on a photopolymerizable composition containing 10 to 70% by weight of a photopolymerizable monomer, 29.5 to 70% by weight of a water-miscible organic solvent, 0.4 to 3% by weight of a photoinitiator and activator, and 0.1 to 3.0% by weight of an antibiotic agent, such as chlorhexidine, alexidine, polyhexanide, or an amine fluoride.

[0010] The above-mentioned dental varnishes contain an organic solvent, most often ethanol. Organic solvents often have a strong, unpleasant odor or taste. Furthermore, they can cause a burning sensation, which is particularly undesirable for treating children. On the other hand, dental varnishes usually contain organic solvents because they must be water-insoluble to prevent premature dissolution by saliva and dry quickly under oral conditions. However, low water solubility is often associated with low water resistance, which can hinder the formation of an adhesive film. This is because it is difficult to keep teeth completely dry during intraoral application of the varnish, and residual water on the teeth can cause varnish components to deposit. Additionally, known fluoride varnishes tend to form strings when applied.

[0011] U.S. Patent Application Publication No. 2008 / 0194753A1 discloses aqueous dispersions of water-soluble and / or water-swellable anionic polymers obtainable by free-radical polymerization of ethylenically unsaturated, anionic monomers, such as acrylic or methacrylic acid, crotonic acid, maleic acid, fumaric acid, vinyl sulfonic acid, styrene sulfonic acid, or vinylphosphonic acid, in an aqueous medium in the presence of at least one stabilizer selected from water-soluble polymers. The purpose of this U.S. patent application is to avoid the use of stabilizing inorganic salts in the preparation of the dispersion. The composition is described as being suitable as a thickener for paper coating slips, pigment printing pastes, dental compounds, etc. Dental varnishes are not disclosed.

[0012] Chinese Patent Application Publication No. 110591008A discloses a process for preparing cationic alkyl core-shell emulsion polymers. In this process, a strongly hydrophilic cationic monomer, such as N-octadecyl acrylamide or octadecyl vinyl ether, is reacted with a long-alkyl-chain hydrophobic monomer, such as cyclopentyl acrylate or cyclohexyl methacrylate, in the presence of an emulsifier, such as tetramethylammonium fluoride or tetramethylammonium chloride, an initiator, such as dilauroyl peroxide or tert-butyl peroxypivalate, and a chain transfer agent, such as sodium hypophosphite or sodium methallylsulfonate. The resulting polymers are described as suitable for coating concrete structures with waterproof coatings with good mechanical properties.

[0013] European Patent Application Publication No. 0 286 009 A2 discloses cationic polymer dispersions containing quaternary organic ammonium compounds with biocidal cationic surface activity. They are described as being useful as antifungal, antibacterial, or antialgal treatments for wood preservation, emulsion paint coatings, polymer plasters, and synthetic resin plasters. The polymer dispersions can be obtained by emulsion polymerization, for example, by azodinitrile-initiated aqueous polymerization of butyl acrylate, methyl methacrylate, and 2-hydroxyethyl methacrylate in the presence of 1-dodecylpyridinium chloride. Chinese Patent Application Publication No. 110627963A discloses a process for preparing quaternary ammonium salt and quaternary phosphonium salt cationic core-shell emulsion polymers. In this process, a strongly hydrophilic cationic monomer is reacted with a small hydrophobic monomer containing a benzene ring via emulsion polymerization. The polymers are described as being suitable for coating cement surfaces with waterproofing coatings that are more environmentally friendly than oil-based coatings, adhere more strongly to surfaces than anionic coatings, and provide better and longer-lasting waterproofing. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] U.S. Patent No. 5,213,615A [Patent Document 2] DE 102 42 476 A1 [Patent Document 3] International Publication No. 2010 / 043606A1 [Patent Document 4] European Patent Application Publication No. 2 705 825 A1 [Patent Document 5] International Publication No. 2015 / 084315A1 [Patent Document 6] US Patent Application Publication No. 2008 / 0194753A1 [Patent Document 7] Chinese Patent Application Publication No. 110591008A [Patent Document 8] European Patent Application Publication No. 0 286 009 A2 [Patent Document 9] Chinese Patent Application Publication No. 110627963A Summary of the Invention [Means for solving the problem]

[0015] overview The object of the present invention is to provide antimicrobial dental varnishes that do not have the above disadvantages. They should be easy to handle and have a mild or pleasant odor and taste. In addition, they should be low in toxicity and form a smooth, colorless, water-resistant, non-corrosive film that adheres well to tooth surfaces (enamel and dentin). Furthermore, the compositions should not be stringy or cause a burning sensation upon application.

[0016] It is a further object of the present invention to provide a dental composition capable of delivering active ingredients such as antimicrobial compounds, desensitizing compounds, bleaching agents, and fluoride to the teeth. A specific object of the present invention is to provide a dental varnish for professional use.

[0017] The present invention provides, for example, the following: (Item 1) (a) 5 to 41 wt. %, preferably 7 to 35 wt. %, more preferably 15 to 30 wt. % of at least one copolymer; (b) 50 to 94 wt. %, preferably 60 to 92 wt. %, more preferably 65 to 84 wt. % water, and (c) 0.5 to 6.0 wt. %, preferably 0.6 to 5.5 wt. %, more preferably 0.7 to 5.0 wt. % of at least one surfactant A cationic polymer dispersion comprising: the dispersion is characterized by comprising at least one antimicrobial compound and being essentially free of low-boiling organic solvents; A cationic polymer dispersion, wherein all weight percentages are based on the total weight of the dispersion. (Item 2) 2. The dispersion according to item 1, comprising 0.001 to 3.0 wt. %, preferably 0.01 to 2.0 wt. %, more preferably 0.1 to 1.5 wt. % of at least one low molecular weight antimicrobial compound (d). (Item 3) said at least one copolymer (a) (a1) 5 to 70 mol %, preferably 10 to 65 mol %, more preferably 15 to 60 mol % of at least one hard (meth)acrylate or vinyl monomer, and (a2) 30 to 95 mol %, preferably 35 to 90 mol %, more preferably 40 to 85 mol % of at least one flexible (meth)acrylate or vinyl monomer is a copolymer obtainable by free radical copolymerization of a monomer mixture comprising The at least one hard monomer has a glass transition temperature (T G ) from 30°C to 130°C, and the at least one flexible monomer is a (meth)acrylate monomer or a vinyl monomer that forms a homopolymer having a glass transition temperature (T G 2. The dispersion of claim 1, wherein the (meth)acrylate or vinyl monomer forms a homopolymer having a Tc of -70°C to 20°C, and all mole percentages are based on the total molar amount of monomers. (Item 4) The monomer (a1) is methyl methacrylate, phenyl(meth)acrylate, naphthyl(meth)acrylate, benzyl(meth)acrylate, adamantyl(meth)acrylate, isobornyl(meth)acrylate, 2-[(methoxycarbonyl)amino]ethyl(meth)acrylate, 2-[(propoxycarbonyl)amino]ethyl(meth)acrylate, 2-[(isopropoxycarbonyl)amino]ethyl(meth)acrylate, 2-[(butoxycarbonyl)amino]ethyl(meth)acrylate, 2-[(hexyloxycarbonyl)amino]ethyl(meth)acrylate, 2-[(cyclohexyloxycarbonyl)amino]ethyl (meth)acrylate, 2-[(cyclohexyloxycarbonyl)amino]ethyl (meth)acrylate, 2-[(benzyloxycarbonyl)amino]ethyl (meth)acrylate, 2-[(ethylcarbamoyl)oxy]ethyl (meth)acrylate, 2-[(propylcarbamoyl)oxy]ethyl (meth)acrylate, 2-[(isopropylcarbamoyl)oxy]ethyl (meth)acrylate, 2-[(hexylcarbamoyl)oxy]ethyl (meth)acrylate, 2-[(benzylcarbamoyl)oxy]ethyl (Meth)acrylate, 2-[(2-tetrahydrofurfuryloxycarbonyl)amino]ethyl (meth)acrylate, 2-[(2-oxo-1,3-dioxolan-4-yl)methoxycarbonylamino]ethyl (meth)acrylate, (meth)acrylic acid 2-(furan-2-yl-methoxycarbonylamino)ethyl ester, (1,3-dioxolan-2-one-4-yl)methyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, 2-(o-biphenyloxy)ethyl (meth)acrylate, 2-hydroxy-3-phenoxy and / or selected from 2-(p-cumylphenoxy)ethyl (meth)acrylate, 2-(p-dimethylphenoxy)ethyl (meth)acrylate, tricyclo(tricylo)decane (meth)acrylate, tricyclodecanemethyl (meth)acrylate and 1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl (meth)acrylate, styrene, p-methylstyrene, p-ethylstyrene, p-methoxystyrene, α-methylstyrene, divinylbenzene, acrylonitrile or mixtures thereof; and / or 4. Dispersion according to item 3, wherein the monomer (a2) is selected from alkyl (meth)acrylates or cycloalkyl (meth)acrylates, n-butyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-dodecyl methacrylate, tetradecyl methacrylate, hexadecyl methacrylate, the corresponding acrylates, hydroxyalkyl (meth)acrylates, 2-hydroxyethyl acrylate, 2-octyl acrylate, 2-hydroxypropyl acrylate, vinyl acetate, vinyl esters of saturated monocarboxylic acids having a highly branched structure and having 5 to 12, preferably 9 or 10, carbon atoms, vinyl esters of neodecanoic and neononanoic acid, or mixtures thereof. (Item 5) 5. The dispersion according to item 4, wherein the monomer (a1) is selected from methyl methacrylate, benzyl methacrylate, styrene, or mixtures thereof, and the monomer (a2) is selected from n-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, or mixtures thereof. (Item 6) 4. The dispersion according to item 3, wherein the monomer mixture comprises, in addition to monomer (a1) and monomer (a2), at least one additional radically polymerizable monomer selected from basic nitrogen-containing monomers, cationic monomers, zwitterionic monomers, antimicrobial monomers and / or adhesive monomers. (Item 7) The weight average molar mass (M W 2. The dispersion according to item 1, wherein the molecular weight of the polymer is 100 to 18000 kDa, preferably 200 to 5000 kDa, more preferably 250 to 3000 kDa. (Item 8) 2. The dispersion according to item 1, wherein the number average particle size of the copolymer (a) is in the range of 5 nm to 900 nm, preferably 30 to 300 nm. (Item 9) The copolymer (a) is (I) Free radical emulsion polymerization of a mixture of monomers (a1) and (a2) in the presence of a cationic surfactant. (II) Free radical emulsion polymerization of monomer (a1) and monomer (a2) using a radical initiator having a cationic group in the presence of a cationic surfactant or preferably a nonionic surfactant. (III) free radical emulsion polymerization of a mixture of monomer (a1), monomer (a2) and at least one cationic monomer in the presence of a cationic surfactant or preferably a nonionic surfactant; or (IV) free radical emulsion polymerization of a mixture of monomer (a1), monomer (a2) and at least one basic nitrogen-containing monomer in the presence of a cationic surfactant or preferably a nonionic surfactant, followed by protonation of the nitrogen-containing monomer units with an acid. Item 1, wherein the copolymer is a copolymer obtainable from (Item 10) 2. The dispersion according to item 1, wherein the at least one surfactant is selected from the group consisting of nonionic surfactants, cationic surfactants, amphoteric surfactants, and polymeric surfactants, preferably nonionic surfactants, and mixtures of cationic surfactants, amphoteric surfactants, and polymeric surfactants with nonionic surfactants. (Item 11) Item 1. The dispersion according to item 1, comprising at least one surfactant having antimicrobial activity selected from cetylpyridinium tetrachlorozinc salt, octenidine dihydrochloride, cetylamine hydrofluoride (Hetaflur), cetylamine hydrochloride, dodecyltrimethylammonium chloride, and cetylpyridinium chloride, and / or at least one low molecular weight antimicrobial agent selected from octenidine, chlorhexidine and salts thereof, chlorhexidine digluconate, and chlorhexidine diacetate. (Item 12) 2. The dispersion of claim 1, further comprising at least one additional ingredient selected from organic or inorganic fluoride sources, humectants, oxidizing agents, sweeteners, colorants, flavors, pH adjusters, soothing agents, and thickeners. (Item 13) (a) 5 to 41 wt. %, preferably 7 to 35 wt. %, more preferably 15 to 30 wt. % of at least one copolymer; (b) 50 to 94 wt. %, preferably 60 to 92 wt. %, more preferably 65 to 84 wt. % water; (c) 0.5 to 6.0 wt. %, preferably 0.6 to 5.5 wt. %, and more preferably 0.7 to 5.0 wt. % of at least one surfactant; (d) 0.001 to 3.0 wt. %, preferably 0.01 to 2.0 wt. %, and more preferably 0.1 to 1.5 wt. % of one or more low molecular weight antimicrobial compounds; (e) 0 to 3.0 wt. %, preferably 0.3 to 3.0 wt. %, more preferably 0.5 to 2.5 wt. %, and most preferably 1.0 to 2.0 wt. % of at least one inorganic or organic fluoride source (F - ), (f) 0 to 30% by weight, preferably 0 to 25% by weight, more preferably 0 to 20% by weight, of one or more humectants; (g) 0 to 16 wt. %, preferably 1 to 16 wt. %, more preferably 3 to 13 wt. % of one or more oxidizing agents, and (h) 0.01 to 10% by weight, preferably 0.1 to 8.0% by weight, more preferably 0.2 to 6.0% by weight of at least one additive selected from sweeteners, colorants, flavors, pH adjusters, soothing agents, thickeners, or mixtures thereof. Including, All weight percentages are based on the total weight of the dispersion. Item 13. The dispersion according to item 12. (Item 14) 14. The dispersion according to any one of items 1 to 13 for use in a method for the treatment or prevention of dental plaque, caries, incipient caries lesions (early caries) gum disease, periodontal disease, periodontitis, peri-implantitis and / or gingivitis. (Item 15) 14. A composition comprising a dispersion according to any one of items 1 to 13 for use in a method for therapeutic or non-therapeutic dental treatment, said method comprising: (i) cleaning the tooth or teeth to remove tartar or other deposits, as needed; (ii) optionally drying the tooth or teeth; (iii) applying the dispersion to at least one tooth surface; and (iv) drying the applied dispersion A composition comprising:

[0018] A cationic polymer dispersion comprising at least one copolymer, water, and at least one surfactant, the dispersion containing at least one antimicrobial agent and essentially free of low-boiling organic solvents, is suitable for use in antimicrobial dental varnishes or coatings. DETAILED DESCRIPTION OF THE INVENTION

[0019] Detailed Description According to the present invention, the object is to provide a method for producing a liquid crystal display device which does not contain a low-boiling organic solvent, (a) 5 to 41 wt. %, preferably 7 to 35 wt. %, more preferably 15 to 30 wt. % of at least one copolymer; (b) 50 to 94 wt. %, preferably 60 to 92 wt. %, more preferably 65 to 84 wt. % water, and (c) 0.5 to 6.0 wt. %, preferably 0.6 to 5.5 wt. %, more preferably 0.7 to 5.0 wt. % of at least one surfactant This is achieved by a cationic polymer dispersion comprising:

[0020] The polymer dispersions of the present invention contain at least one low molecular weight antimicrobial compound, which may be an antimicrobial surfactant (c) or a separate compound.

[0021] The cationic polymer dispersion of the present invention is essentially free of low-boiling organic solvents. The term "dispersion essentially free of low-boiling solvents" is understood to mean that the content of said solvents is less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight.

[0022] According to the present invention, a low-boiling organic solvent is an organic solvent having a boiling point below 100°C, preferably below 160°C, more preferably below 180°C, and most preferably below 205°C. The boiling point is measured at atmospheric pressure. In particular, the cationic polymer dispersion of the present invention does not contain methylene chloride, methyl t-butyl ether, acetone, 1,2-dimethoxyethane, methanol, ethanol, ethyl acetate, 1-propanol, 2-propanol, 2-butanone, t-butanol, and 2-butanol, more preferably does not contain dimethylformamide and 1,4-dioxane, and most preferably does not contain N-methyl-2-pyrrolidone.

[0023] The at least one copolymer (a) is preferably (a1) 5 to 70 mol %, preferably 10 to 65 mol %, more preferably 15 to 60 mol % of at least one hard (meth)acrylate or vinyl monomer, and (a2) 30 to 95 mol %, preferably 35 to 90 mol %, more preferably 40 to 85 mol % of at least one flexible (meth)acrylate or vinyl monomer It is a copolymer obtainable by free radical copolymerization of a monomer mixture comprising:

[0024] Unless otherwise stated, all mole percentages herein relate to the total molar amount of all monomers.

[0025] Monomer (a1) is a hard (meth)acrylate or vinyl monomer or a mixture thereof. According to the invention, the hard monomer has a glass transition temperature (T G ) is a monomer that forms a homopolymer having a temperature of 30°C to 130°C, preferably 50°C to 120°C. Particularly preferred are hard monomers having a water solubility of less than 0.1 g / L at room temperature (22°C).

[0026] Preferred hard (meth)acrylate monomers are methyl methacrylate, phenyl (meth)acrylate, naphthyl (meth)acrylate, benzyl (meth)acrylate, adamantyl (meth)acrylate or isobornyl (meth)acrylate, 2-[(methoxycarbonyl)amino]ethyl (meth)acrylate, 2-[(propoxycarbonyl)amino]ethyl (meth)acrylate, 2-[(isopropoxycarbonyl)amino]ethyl (meth)acrylate. ) acrylate, 2-[(butoxycarbonyl)amino]ethyl (meth)acrylate, 2-[(hexyloxycarbonyl)amino]ethyl (meth)acrylate, 2-[(cyclohexyloxycarbonyl)amino]ethyl (meth)acrylate, 2-[(benzyloxycarbonyl)amino]ethyl (meth)acrylate, 2-[(ethylcarbamoyl)oxy]ethyl (meth)acrylate, 2-[(propylcarbamoyl)oxy]ethyl (meth)acrylate Acrylate, 2-[(isopropylcarbamoyl)oxy]ethyl (meth)acrylate, 2-[(hexylcarbamoyl)oxy]ethyl (meth)acrylate, 2-[(benzylcarbamoyl)oxy]ethyl (meth)acrylate, 2-[(2-tetrahydrofurfuryloxycarbonyl)amino]ethyl (meth)acrylate, 2-[(2-oxo-1,3-dioxolan-4-yl)methoxycarbonylamino]ethyl (meth)acrylate, (meth ) acrylic acid 2-(furan-2-yl-methoxycarbonylamino)ethyl ester, (1,3-dioxolan-2-one-4-yl)methyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, 2-(o-biphenyloxy)ethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-phenoxypropyl (meth)acrylate, 2-(p-cumylphenoxy)ethyl (meth)acrylate. Tricyclodecane (meth)acrylate, tricyclodecane methyl (meth)acrylate, and 1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl (meth)acrylate are the most preferred (meth)acrylate monomers.

[0027] Preferred hard vinyl monomers are styrene and styrene derivatives such as p-methylstyrene, p-ethylstyrene, p-methoxystyrene, α-methylstyrene, divinylbenzene and acrylonitrile.

[0028] The most preferred hard monomers are methyl methacrylate and styrene.

[0029] The monomer mixture comprises from 5 to 70 mol %, preferably from 10 to 65 mol %, more preferably from 15 to 60 mol % of at least one hard (meth)acrylate or vinyl monomer or mixtures thereof.

[0030] Monomer (a2) is a flexible (meth)acrylate or vinyl monomer or a mixture thereof. According to the present invention, the flexible monomer has a glass transition temperature (T G ) are monomers that form homopolymers with a temperature of -70°C to 20°C, preferably -65°C to 0°C, and most preferably -60°C to -20°C. Flexible monomers with a water solubility of less than 0.1 g / L at room temperature (22°C) are preferred.

[0031] Preferred flexible (meth)acrylate monomers are alkyl (meth)acrylates or cycloalkyl (meth)acrylates, such as n-butyl methacrylate (T G : 20°C), n-pentyl methacrylate (T G : 10℃), n-hexyl methacrylate (T G : -5℃), 2-ethylhexyl methacrylate (T G : -10℃), n-octyl methacrylate (T G : -20℃), n-dodecyl methacrylate (T G :-65℃), tetradecyl methacrylate (T G : -9℃) or hexadecyl methacrylate (T G : 16°C) and the corresponding acrylates, and hydroxyalkyl (meth)acrylates, such as 2-hydroxyethyl acrylate (T G: -14℃), 2-octyl acrylate (T G : -44°C) and 2-hydroxypropyl acrylate.

[0032] Preferred flexible vinyl monomers are vinyl acetate, vinyl esters of saturated monocarboxylic acids having a highly branched structure and having 5 to 12, preferably 9 or 10, carbon atoms. The vinyl esters of neodecanoic and neononanoic acids, i.e., vinyl neodecanoate and vinyl neononanoate, are particularly preferred.

[0033] The most preferred flexible monomer is n-butyl acrylate (T G : -54℃), n-hexyl acrylate (T G : -57℃) and 2-ethylhexyl acrylate (T G :-50℃).

[0034] The monomer mixture comprises 30 to 95 mol %, preferably 35 to 90 mol %, more preferably 40 to 85 mol % of at least one soft monomer, most preferably at least one (meth)acrylate monomer.

[0035] According to the present invention, the glass transition temperature (T G ) is measured by a differential scanning calorimeter, preferably at an amplitude of 2°C for 60 seconds, with a heating rate of 10°C min -1 The samples were measured by a TA Instruments differential scanning calorimeter DSC Q2000 (TA Instruments, New Castle) in the controlled mode of T G The sample is cooled to below, for example, -50°C, and two thermal scans are performed up to 150°C and the average value calculated.

[0036] The monomer mixture may further comprise one or more additional radically polymerizable monomers selected from basic nitrogen-containing monomers, zwitterionic monomers, antimicrobial monomers, preferably cationic monomers and / or adhesive monomers, and mixtures thereof. According to the present invention, the basic nitrogen-containing monomers are monomers containing one or more primary, secondary and / or tertiary amino groups.

[0037] Basic nitrogen-containing monomers can be used to introduce cationic groups into the copolymer by subsequently adding an acid that leads to protonation of the amino group. Preferred nitrogen-containing monomers are (meth)acrylates, especially N,N-dialkylaminoalkyl (meth)acrylates, such as 2-(dimethylamino)ethyl (meth)acrylate, 2-(diethylamino)ethyl (meth)acrylate, 3-(dimethylamino)propyl (meth)acrylate, and 3-(diethylamino)propyl (meth)acrylate, as well as N,N-dialkylaminoalkyl (meth)acrylamides, such as dialkylaminoethyl (meth)acrylamide or dialkylaminopropyl (meth)acrylamide. 2-(dimethylamino)ethyl methacrylamide and 2-(dimethylamino)ethyl acrylamide are particularly preferred.

[0038] The monomer mixture may contain from 0 to 15 mol %, preferably from 0.1 to 15 mol %, more preferably from 0.1 to 10 mol %, and most preferably from 0.1 to 5 mol % of one or more basic nitrogen-containing monomers.

[0039] Preferred cationic monomers are (meth)acryloyloxyalkyltrialkylammonium halides, such as [2-(methacryloyloxy)ethyl]trimethylammonium chloride, [2-(acryloyloxy)ethyl]trimethylammonium chloride, [2-(methacryloyloxy)ethyl]trimethylammonium bromide, [2-(acryloyloxy)ethyl]trimethylammonium bromide, [3-(methacryloyloxy)propyl]trimethylammonium chloride, [4-(methacryloyloxy)butyl]trimethylammonium chloride, [2-(methacryloyloxy)ethyl]triethylammonium chloride and [2-(acryloyloxy)ethyl]triethylammonium chloride.

[0040] Furthermore, polymerizable quaternary ammonium salts, in particular (3-methacryloyloxypropyl)dimethyldodecylammonium bromide, N-(2-methacryloyloxyethyl)-N,N-dimethylcetylammonium chloride, dimethyl-(4-vinylbenzyl)hexadecylammonium chloride, dimethyl-(4-vinylbenzyl)dodecylammonium chloride and 2-dimethyl-2-dodecyl-1-methacryloxyethylammonium iodine are preferred as cationic monomers. Pyridinium monomers such as 12-(methacryloyloxy)dodecyl)pyridinium bromide, 11-(methacryloyloxy)undecyl)pyridinium bromide, 10-(methacryloyloxy)decylpyridinium bromide, 8-(methacryloyloxy)octylpyridinium bromide, 6-(methacryloyloxy)hexyl)pyridinium bromide, and 4-(methacryloyloxy)-2,2-dimethylpropyl)pyridinium bromide are also preferred.

[0041] Further preferred cationic monomers are N-4-(2-methacryloyloxyethyl)-phenyl-N'-4-chlorophenylbiguanide hydrochloride, 1-vinyl-3-octylimidazolium tetrafluoroborate, 1-vinyl-3-butyl-imidazolium hexafluorophosphate, 1-vinyl-3-hexylimidazolium hexafluorophosphate, 1-vinyl-3-octyl-imidazolium hexafluorophosphate and imidazolium compounds such as 1-methylacrylamide. and 1-(2-(((2-(methacryloyloxy)ethyl)carbamoyl)oxy)ethyl)-3-decyl-imidazolium bromide, 1-(2-(((2-(methacryloyloxy)ethyl)carbamoyl)oxy)ethyl)-3-dodecyl-imidazolium bromide, or 1-(2-(((2-(methacryloyloxy)ethyl)carbamoyl)oxy)ethyl)-3-decyl-imidazolium bromide.

[0042] Particularly preferred cationic monomers are [2-(methacryloyloxy)ethyl]trimethylammonium chloride, [2-(methacryloyloxy)ethyl]triethylammonium chloride, methacryloyloxydodecylpyridinium bromide, methacryloxyethylhexadecylmethylammonium bromide, 12-(methacryloyloxy)dodecyl)pyridinium bromide, 11-(methacryloyloxy)undecyl)pyridinium bromide, and 10-(methacryloyloxy)decylpyridinium bromide.

[0043] The monomer mixture may contain from 0 to 15 mol %, preferably from 0.1 to 15 mol %, more preferably from 0.1 to 10 mol %, and most preferably from 1 to 5 mol % of one or more cationic monomers.

[0044] Zwitterionic monomers contain both cationic and anionic groups in the same molecule. Preferred zwitterionic monomers are sulfobetaine monomers, such as 3-{[2-(methacryloyloxy)ethyl]dimethylammonio}propane-1-sulfonate, 4-[[2-methacryloyloxy)ethyl]dimethylammonio]butane-1-sulfonate, 4-[[2-acryloyloxy)ethyl]dimethylammonio]butane-1-sulfonate, 3-[bis[methacryloyloxy)ethyl](methylammonio]propane-1-sulfonate, 3-[(3-methacrylamidopropyl)dimethylammonio]propane-1-sulfonate, 4-[(3-methacrylamidopropyl)dimethylammonio]butane-1-sulfonate, and 3-[(3-acrylamidopropyl)dimethylammonio]propane-1-sulfonate.

[0045] Furthermore, carboxybetaine monomers such as 2-[[2-(methacryloyloxy)ethyl]dimethylammonio]acetate, 3-[[2-(methacryloyloxy)ethyl]dimethylammonio]propionate or 3-[(3-acrylamidopropyl)dimethylammonio]propionate, and phosphobetaine monomers such as 2-methacryloyloxyethylphosphorylcholine and 2-acryloyloxyethylphosphorylcholine are preferred as zwitterionic monomers.

[0046] A particularly preferred zwitterionic monomer is 3-[[2-(methacryloyloxy)ethyl]dimethylammonio]propane-1-sulfonate.

[0047] The monomer mixture may contain from 0 to 15 mol %, preferably from 0 to 10 mol %, more preferably from 0 to 5 mol % of one or more zwitterionic monomers.

[0048] Preferred antimicrobial monomers are nonionic monomers such as 2-(meth)acryloyloxyethyl p-hydroxybenzoate, eugenyl(meth)acrylate (4-allyl-2-methoxyphenyl(meth)acrylate), 2-(4-allyl-2-methoxyphenoxy)-1-hydroxyethyl(meth)acrylate, thymol(meth)acrylate (2-isopropyl-5-methylphenyl(meth)acrylate), 2-(((thiazol-5-ylmethoxy)carbonyl)amino)ethyl(meth)acrylate, (((2-(benzo[d]thiazol-2-ylthio)ethoxy)carbonyl)amino)methyl(meth)acrylate, and 2-((3,4-dichloro-5-oxo-2,5-dihydrofuran-2-yl)oxy)ethyl(meth)acrylate. Further preferred antimicrobial monomers are cationic monomers, especially cationic monomers having quaternary ammonium groups, such as the polymerizable quaternary ammonium salts described above.

[0049] The monomer mixture may contain from 0 to 10 mole %, preferably from 0 to 8 mole %, more preferably from 0 to 5 mole % of one or more nonionic antimicrobial monomers.

[0050] When applied to teeth, the cationic copolymer dispersions of the present invention form smooth films that adhere well to tooth enamel. If desired, adhesion can be improved by using adhesive monomers to prepare the copolymers. Adhesive monomers are monomers that can interact with dental hard tissues (enamel and dentin) to form ionic or covalent bonds. For example, monomers containing one or more acidic or chelating groups can react with calcium ions. In this way, adhesive monomers can improve adhesion to enamel.

[0051] Preferred adhesive monomers are radically polymerizable monomers having at least one acid group, preferably a carboxylic acid group, a phosphate ester group, and / or a phosphonic acid group, more preferably a carboxylic acid group or a phosphate ester group, and most preferably a monohydrogen phosphate group or a dihydrogen phosphate group. In this specification, adhesive monomers are also referred to as acidic monomers. Preferred radically polymerizable groups are acrylate groups, especially methacrylate groups. Thus, monomers containing at least one (meth)acrylate group and at least one carboxylic acid group, phosphonic acid group, or phosphate ester group are particularly preferred. Polymerizable carboxylic acids and dihydrogen phosphates are most preferred.

[0052] Preferred acidic monomers containing a COOH group are (meth)acrylic acid, 4-(meth)acryloyloxyethyl trimellitic acid, 10-methacryloyloxydecylmalonic acid, N-(2-hydroxy-3-methacryloyloxypropyl)-N-phenylglycine, and 2-carboxyethyl acrylate (CEA).

[0053] The preferred radically polymerizable phosphonic acid is 2-[4-(dihydroxyphosphoryl)-2-oxa-butyl]acrylic acid and its esters, such as ethyl 2-[4-(dihydroxyphosphoryl)-2-oxa-butyl]acrylate (EDOBA) and 2,4,6-trimethylphenyl 2-[4-(dihydroxyphosphoryl)-2-oxa-butyl]acrylate. EDOBA is the most preferred.

[0054] Preferred radically polymerizable dihydrogen phosphates are 2-methacryloyloxyethylphenyl hydrogen phosphate, 10-methacryloyloxydecyl dihydrogen phosphate (MDP), glycerin dimethacrylate dihydrogen phosphate, and dipentaerythritol pentamethacryloyloxydihydrogen phosphate. In most cases, MDP is preferred.

[0055] The monomer mixture may contain from 0 to 10 mol %, preferably from 0 to 7 mol %, more preferably from 0.1 to 5 mol %, and most preferably from 1 to 5 mol % of one or more acidic monomers.

[0056] Preferred chelating monomers are those containing one or more chelating groups capable of interacting with calcium ions. Preferred examples are β-ketones, β-ketoesters, and monomers containing chelating alkylenediamine diacetate, triacetate, or tetraacetate groups. A preferred chelating monomer is the commercially available β-ketoester 2-acetoacetoxyethyl methacrylate. Suitable styryl-group-containing polymerizable β-diketones are described in Chinese Patent No. 102079693B. Further examples of chelating monomers are reaction products of ethylenediaminediacetic acid or ethylenediaminetriacetic acid with glycidyl (meth)acrylate, particularly the compounds described in International Patent Application No. 2013 / 066927. 2-acetoacetoxyethyl methacrylate is the most preferred chelating monomer.

[0057] The monomer mixture may contain 0 to 10 mole %, preferably 0 to 7 mole %, more preferably 0 to 5 mole % of one or more chelating monomers.

[0058] The weight average molar mass of copolymer (a) is preferably between 100 and 18000 kilodaltons (1 Dalton = 1 Da = 1 g / mol), more preferably between 200 and 5000 kDa, most preferably between 250 and 3000 kDa.

[0059] Weight average molar mass (M W) is measured by asymmetric flow field fractionation (AF4) combined with multi-angle light scattering (MALS) and refractive index (RI) detectors (AF4 / MALS / RI). Separation is performed in a 27.5 cm trapezoidal channel mounted on upper and lower blocks made of PEEK (polyetheretherketone) with stainless steel frits. A channel thickness spacer with a thickness of 490 μm is used. The accumulation wall is a regenerated cellulose membrane with a molar mass cutoff of 10,000 Da. AF4 flow control can be performed using a Wyatt Eclipse 3 AF4 Separation System Controller (Wyatt Technology, USA). The preferred MALS detector is the Dawn Heleos II detector (Wyatt Technology, USA), and the preferred RI detector is the Optilab Rex detector (Wyatt Technology, USA). The dn·dc used -1 The value is chosen according to the respective polymer (for PMMA it is 0.084 ml g -1 , and 0.064 ml·g for PBA. -1 ) The initial cross-flow rate was 3.0 ml min -1 is used, but 0.05 ml min over 42 minutes -1 The AF4 / MALS / RI data were analyzed using ASTRA software version 6.1 (Wyatt Technology, USA). Absolute molar masses were calculated from the MALS / RI data using a Debye plot (in first-order Zimm format).

[0060] If necessary, a transfer agent can be used to control the molecular weight of copolymer (a). Preferred transfer agents are sulfur compounds such as thiodiglycol, thioethanol, di-n-butyl sulfide, 2-mercaptoethanol, 1,3-mercaptopropanol, 3-mercaptopropane-1,2-diol, 1,4-mercaptobutanol, and thioglycolic acid. More preferred chain transfer agents are aldehydes, organic acids such as formic acid, sodium formate, or ammonium formate, and phosphorus compounds such as sodium hypophosphite. If necessary, the transfer agent is used in an amount of 0.01 to 0.5% by weight based on the total amount of monomers.

[0061] The composition of the present invention comprises at least one copolymer (a) in dispersed form. Preferably, the at least one copolymer (a) is in the form of particles whose size can vary from a few nanometers to a few micrometers. Preferably, the number-average particle size of the copolymer is 5 to 900 nm, more preferably 30 to 300 nm. Polymer particles having a particle size of less than about 50 nm result in highly transparent copolymer dispersions. Dispersions containing polymer particles with a diameter of a few micrometers appear translucent, cloudy, or white.

[0062] Particle size is measured by dynamic light scattering, preferably using a Malvern Zetasizer (Nano Series, Malvern). For analysis, a sample of the dispersion is diluted to 1:10 with pure water (milli-Q water) so that unswollen particles are measured. -3 The sample is diluted to a concentration of less than 100% by weight. The analysis is carried out at 25°C. Each sample is analyzed in triplicate and the average value is calculated. The particle size is calculated according to the Stokes-Einstein equation.

[0063] Polymer dispersions, also called latexes, are colloidal dispersions of polymer particles in an aqueous phase (b). They are stable for long periods of time and do not settle. Synthetic polymer dispersions can be prepared by emulsion, miniemulsion, microemulsion, dispersion, or suspension polymerization of the corresponding monomers in the presence of a dispersing agent (emulsifier or suspending agent). Depending on the charge of the polymer particles and the type of dispersing agent, a distinction is made between cationically stabilized and anionically stabilized polymer dispersions. In cationic polymer dispersions, the dispersed polymer particles have a positive charge. For example, the polymer may contain cationic groups, such as quaternary ammonium groups, and dispersions containing polymers with basic nitrogen-containing monomers may be stabilized by the addition of acid. Alternatively, cationic dispersions can be prepared using cationic dispersing agents.

[0064] Polymerization is initiated by a radical polymerization initiator, preferably a thermal initiator or redox initiator. Preferred thermal initiators are water-soluble peroxides, hydroperoxides, and azo compounds, such as 2,2'-azobis(isobutylamidine) dihydrochloride or 2,2'-azobis(N,N-dimethyleneisobutylamidine) dihydrochloride (both manufactured by Wako Chemical GmbH), which are radical initiators having cationic groups, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) and 2,2-azobis(2,4-dimethylvaleronitrile). More preferred thermal initiators are hydrogen peroxide and sodium or potassium persulfate.

[0065] The redox initiator system includes an oxidizing agent in combination with a reducing agent. Preferred oxidizing agents are the thermal initiators described above and alkyl hydroperoxides, such as t-butyl hydroperoxide. Preferred reducing agents are ascorbic acid and its derivatives and salts, barbituric acid and its derivatives and salts, thiourea and its derivatives, and sulfinic acid and its salts and derivatives.

[0066] Highly preferred initiators are 2,2'-azobis(isobutylamidine) dihydrochloride and sodium or potassium persulfate.

[0067] The at least one initiator or initiator system is preferably used in an amount of 0.01 to 1.0 mol %, preferably 0.03 to 0.8 mol %, more preferably 0.04 to 0.5 mol %, based on the total amount of monomers.

[0068] The initiator may be added to the monomer mixture before it is emulsified in the aqueous phase, or preferably, the initiator is first dissolved or dispersed in water and then the initiator solution or dispersion is added to the emulsion of the monomer mixture in water.

[0069] Preferably, the dispersion of copolymer (a) is prepared by one of the following synthetic methods: (I) Free radical emulsion polymerization of a mixture of monomers (a1) and (a2) in the presence of a cationic surfactant. (II) Free radical emulsion polymerization of monomer (a1) and monomer (a2) using a radical initiator having a cationic group in the presence of a cationic surfactant or preferably a nonionic surfactant. (III) free-radical emulsion polymerization of a mixture of monomer (a1), monomer (a2) and at least one cationic monomer in the presence of a cationic surfactant or, preferably, a nonionic surfactant. (IV) Free radical emulsion polymerization of a mixture of monomer (a1), monomer (a2) and at least one basic nitrogen-containing monomer in the presence of a cationic surfactant or preferably a nonionic surfactant, followed by protonation of the nitrogen-containing monomer units with an acid, preferably with HCl.

[0070] In all cases, an antimicrobial monomer can be added if desired. Acidic monomers react with the basic monomers used in Method (IV) and must be treated according to Methods (I) to (III). Methods (I) to (III) are preferred, with Methods (I) and (II) being more preferred. Zwitterionic monomers are treated according to Method (III), using zwitterionic monomers instead of cationic monomers.

[0071] In method (I), it is preferred to use a cationic surfactant in an amount of preferably 0.01 to 1.0% by weight based on the total amount of monomers.

[0072] In method (II), it is preferred to use nonionic surfactants in amounts of preferably 0.01 to 2.0% by weight, and radical initiators having cationic groups in amounts of preferably 0.01 to 0.5% by weight, based in each case on the total amount of monomers.

[0073] In method (III), it is preferred to use a nonionic surfactant in an amount of preferably 0.01 to 1.0% by weight, and at least one cationic monomer in an amount of 0.1 to 15 mol %, in each case based on the total amount of monomers.

[0074] In method (IV), it is preferred to use a nonionic surfactant in an amount of preferably 0.01 to 1.0 wt % based on the total amount of monomers, and it is preferred to use at least one basic nitrogen-containing monomer in an amount of 0.1 to 15 mol % based on the total amount of monomers. After the copolymerization step, the nitrogen-containing monomer units of the polymer are protonated by adding 10 to 100 mol % of an acid, preferably HCl, HBr or HNO3, based on the amount of basic nitrogen-containing monomer units.

[0075] Thus, the (meth)acrylic copolymer dispersion (latex) is preferably synthesized by free-radical emulsion polymerization of a mixture of monomers emulsified in water using a water-soluble or oil-soluble initiator and an emulsifier and / or surfactant. The emulsion polymerization process can be carried out as a batch polymerization, in which all raw materials are added to the reaction vessel at the start of the reaction, or as a semi-continuous or semi-batch polymerization, in which the monomers are added continuously or in stages in solvent-free or emulsion form. The polymerization can also be carried out as a continuous process, in which all raw materials are added continuously to one point in the reaction system and the latex is continuously removed from another point.

[0076] In all cases, the emulsion polymerization process preferably includes a particle nucleation stage and a particle growth stage. These stages can be performed sequentially or simultaneously. A seed latex can be used to avoid the particle nucleation stage. The seed latex can be prepared by in situ polymerization or, preferably, in a separate reaction. The use of a separately prepared seed latex results in improved batch-to-batch reproducibility.

[0077] Preferably, the polymerization is carried out in a batch or semi-batch process in which a mixture of monomer, surfactant, and a sufficient amount of water is stirred in a reactor equipped with a condenser, a nitrogen inlet, and a mechanical stirrer, followed by the addition of a radical initiator. The polymerization mixture is preferably stirred under a nitrogen atmosphere, for example, at 50 to 1000 rpm (revolutions per minute), and may be further heated if a thermal initiator is used. In process (IV), after the polymerization step is completed, an appropriate amount of acid is added.

[0078] The composition of the copolymer is determined by the type and ratio of the monomers used and by the copolymerization parameters. The amount of water determines the final solids content of the latex. The water content of the final latex is preferably adjusted to within the range of 5 to 50% by weight, more preferably 10 to 45% by weight, and most preferably 15 to 40% by weight, based on the total weight of the dispersion. The polymerization time depends on the polymerization conditions and is preferably within the range of 0.2 to 20 hours, more preferably 0.5 to 15 hours, and most preferably 1 to 10 hours. It is selected to achieve the highest possible monomer conversion. To optimize the monomer conversion, it may be advantageous to perform a post-polymerization step, for example by adding an additional amount of initiator and / or increasing the polymerization temperature.

[0079] Overall Monomer Conversion X overall is determined by gravimetrically measuring the non-volatile fraction of the dispersion. The overall monomer conversion is the amount of polymer (m pol (t); t = end point of reaction) mon,total ) and dividing by: X overall =m pol (t) / m mon,total

[0080] Residual monomers can be measured by gas chromatography (GC), for example, using a GC-14A chromatograph (Shimadzu) equipped with a flame ionization detector and a polar PEG-column modified with nitroterephthalic acid (BP21 FFAP (free fatty acid phase) column from SGE Analytical Science; length 25 m, internal diameter 0.53 mm, film thickness 0.5 μm).

[0081] The cationic polymer dispersions of the present invention exhibit high colloidal stability, i.e., they do not settle or aggregate. An indicator of colloidal stability is the zeta potential of the copolymer particles. The zeta potential can be measured using a Zetasizer Nano instrument (Malvern). For analysis, a sample of the copolymer dispersion is diluted with pure water (milli-Q water) to 1:10 so that unswollen particles are measured. -3 The sample is diluted to a concentration of less than 100% by weight. The analysis is carried out at 25°C. Each sample is analyzed in triplicate and the average value is calculated.

[0082] The glass transition temperature of the dispersed copolymer particles of the present invention is preferably -20 to 55°C, more preferably -10 to 50°C, and most preferably -5 to 40°C. The glass transition temperature of the copolymer particles is important for the film-forming properties of the copolymer dispersion. The ability of polymer dispersions to form thin, continuous films after evaporation of water (drying) is important for their application as varnishes or coatings. The so-called minimum film-forming temperature (MFFT) is the lowest temperature at which a transparent film is formed by a polymer dispersion. The MFFT depends on the glass transition temperature of the copolymer particles in the dispersion. The MFFT is preferably measured using an MFFT Bar instrument (MFFT-90, Rhopoint Instruments Ltd., St. Leonards-on-Sea, UK). For measurement, a wet layer of the dispersion, 90 μm thick, is placed on a temperature gradient bar with a temperature range of 5 to 85°C. The MFFT of membranes prepared using the copolymer dispersions of the present invention is preferably in the range of 0 to 60°C, more preferably 2.5 to 50°C, and most preferably 5 to 40°C.

[0083] The copolymer dispersion according to the present invention contains at least one surfactant (c). The surfactant (c) colloidally stabilizes the monomer emulsion and the final copolymer dispersion. Colloidal stabilization of copolymer particles can be achieved by ionic and nonionic surfactants. The surfactant molecules can be physically or chemically bonded to the surface of the copolymer particles. For example, polymerization of nonionic monomer (a1) with monomer (a2) results in the formation of nonionic copolymer particles. The chemical or physical bond of the cationic surfactant confers a positive charge on these particles, causing cationic stabilization. For cationic copolymer particles, nonionic surfactants can be used, which primarily act as emulsifiers.

[0084] The at least one surfactant is selected from the group consisting of nonionic surfactants, cationic surfactants, amphoteric surfactants, and polymeric surfactants. Nonionic surfactants, as well as mixtures of cationic surfactants, amphoteric surfactants, and polymeric surfactants with nonionic surfactants, are preferred. For nonionic copolymers, the use of cationic surfactants is essential.

[0085] Preferred nonionic surfactants are alkyl ethoxylates, ethylene oxide-propylene oxide block copolymers, and polysorbates. Preferred alkyl ethoxylates are those of the formula (i) CH3(CH2) n O(CH2CH2O) x H, where n=8 to 71, more preferably 10 to 35, and x=5 to 200, more preferably 10 to 40, and (ii) an ethoxylated fatty alcohol of the formula CH(CH) n COO(CH2CH2O) xH, where n=8 to 71, more preferably 10 to 35, and x=5 to 200, more preferably 10 to 40. Preferred ethylene oxide-propylene oxide block copolymers are those with a molecular weight of 1000 to 15000 g / mol. Polysorbates are esters of polyethoxylated sorbitan with fatty acids, preferably with dodecanoic acid, oleic acid, or hexadecanoic acid.

[0086] Preferred cationic surfactants are alkyltrimethyl, dialkyldimethyl or alkylaryldimethylammonium compounds with various counterions, such as dimethyldioctadecylammonium bromide, hexadecyltrimethylammonium bromide, octenidine dihydrochloride and other salts of octenidine, cetyltrimethylammonium bromide, cetylamine hydrofluoride (Hetaflur), cetylamine hydrochloride, cetylpyridinium chloride (CPC), dodecyltrimethylammonium chloride, dimethyldidodecylammonium bromide or benzyldimethylhexadecylammonium chloride.Further preferred cationic surfactants are fatty amine salts, fatty diamine salts and imidazolium salts.

[0087] Preferred amphoteric (zwitterionic) surfactants are alkyl betaines and alkylamido betaines. Preferred alkyl betaines are cetyl betaine, lauryl betaine, oleyl betaine, and stearyl betaine. Preferred alkylamido betaines are cocamidopropyl betaine, oleamidopropyl betaine, and laurylamidopropyl betaine.

[0088] Polymeric surfactants or surface-active oligomers can also be used. These are random or block copolymers of hydrophobic monomers and monomers containing carboxylic acid moieties. Preferred hydrophobic monomers are methylstyrene, styrene, and methyl methacrylate, and preferred carboxylic acid group-containing monomers are acrylic acid and methacrylic acid. The molecular weight of the polymeric surfactants is preferably in the range of 4,000 to 40,000 g / mol, more preferably 5,000 to 20,000 g / mol.

[0089] Preferred polymeric nonionic surfactants are polyethylene oxide-polypropylene oxide block copolymers.

[0090] The surfactant may contain one or more, preferably one, olefinically unsaturated group capable of participating in free radical polymerization. The surfactant may be chemically linked to the surface of the copolymer particle. Polymerizable surfactants are also called surfmers. Surfmers may have ionic or nonionic moieties, with nonionic surfmers being preferred according to the present invention.

[0091] Preferred nonionic surfmers are vinyl polyoxyethylene glycol ethers and allyl polyoxyethylene glycol ethers or allyl polyoxypropylene glycol ethers having 10 to 30, preferably 20, oxyalkylene (EO or PO) units, and allyl phenyl polyol ether sulfates and allyl phenyl polyol ether ammonium salts having 10 to 30 EO or PO units, respectively.

[0092] To achieve a uniform dispersion of the monomer mixture in the aqueous phase, it is preferred to add at least one surfactant (c) to the aqueous phase (b) along with the monomer mixture (a). After the emulsion polymerization is complete, additional amounts of one or more surfactants may be added. Preferably, one or more nonionic surfactants are added during or after the addition of additional components as required to stabilize the dispersion. The total amount of surfactant is within the range specified above, which is 0.5 to 6.0 wt. %, preferably 0.6 to 5.5 wt. %, and more preferably 0.7 to 5.0 wt. %, based on the total weight of the dispersion.

[0093] The composition of the present invention comprises at least one antimicrobial compound. The antimicrobial compound may be an antimicrobial surfactant. Preferred antimicrobial surfactants (c) are cetylpyridinium tetrachlorozinc salt, octenidine dihydrochloride, cetylamine hydrofluoride (Hetaflur), cetylamine hydrochloride, more preferably dodecyltrimethylammonium chloride, most preferably cetylpyridinium chloride, and mixtures thereof. The antimicrobial surfactant is preferably used in an amount of at least 0.001% by weight, more preferably at least 0.01% by weight, and most preferably at least 0.1% by weight, with the total amount of surfactant being within the above range.

[0094] If the surfactant (c) does not have antimicrobial activity, at least one low molecular weight antimicrobial agent (d) must be added. However, the polymer dispersion according to the present invention may further contain both a surfactant having antimicrobial activity and an antimicrobial agent (d). The antimicrobial agent (d) is not a surfactant. According to the present invention, a low molecular weight antimicrobial agent is a compound having a molecular weight of <1500 g / mol, preferably <1250 g / mol, more preferably <1000 g / mol.

[0095] Preferred low molecular weight antimicrobial compounds (d) are quaternary ammonium compounds such as octenidine, benzalkonium chloride and benzethonium chloride; biguanides such as chlorhexidine (and its salts), chlorhexidine digluconate, chlorhexidine diacetate, chlorhexidine dihydrochloride, alexidine and its salts; azole antifungals such as clotrimazole, fluconazole, irtraconazole, ketoconazole, miconazole, voloconazole, posaconazole and oteseconazole; parabens (esters of p-hydroxybenzoic acid), such as methylparaben, ethylparaben, propylparaben, and butylparaben, and their salts, and other antimicrobial agents, such as sorbic acid and its salts, glyoxal, glutaraldehyde, diazolidinyl urea, imidazolinyl urea, ethacridine lactate, piroctone olamine, hexetidine, triclosan, and essential oils such as thymol or eugenol. Additional antimicrobial agents include drug antibiotics, such as aminoglycosides, e.g., amikacin, gentamicin, kanamycin, neomycin, netilmicin, tobramycin, paromomycin, streptomycin, and spectinomycin (Bs); ansamycins, e.g., geldanamycin, herbimycin, and rifaximin; carbapenems, e.g., ertapenem, doripenem, imipenem / cilastatin, and meropenem; glycolpeptides, e.g., teicoplanin, vancomycin, telavancin, dalbavancin, and oritavancin; lincosamides, e.g., clindamycin, isin and lincomycin; macrolides such as azithromycin, clarithromycin, erythromycin, roxithromycin, telithromycin, spiramycin, and fidaxomicin; nitrofurans such as furazolidone and nitrofurantoin; oxazolidinones such as linezolid, pocizolid, radezolid, or torezolid; penicillins such as amoxicillin, ampicillin, azlocillin, dicloxacillin, flucloxacillin, mezlocillin, methicillin, nafcillin, oxacillin, penicillin, piperacillin, temocillin, and ticarcillin;Quinolones / fluoroquinolones, such as ciprofloxacin, enoxacin, gatifloxacin, gemifloxacin, levofloxacin, lomefloxacin, moxifloxacin, nadifloxacin, nalidixic acid, norfloxacin, ofloxacin, trovafloxacin, grepafloxacin, sparfloxacin, and temafloxacin; sulfonamides, such as mafenide, sulfacetamide, sulfadiazine, silver sulfadiazine, sulfadimethoxine, sulfamethizole, sulfamethoxazole, sulfasalazine, and sulfisoxazole; tetracyclines, such as demeclocycline, doxycycline, thiazolinone ... antimycobacterial drugs such as clofazimine, dapsone, capreomycin, cycloserine, ethambutol, ethionamide, isoniazid, pyrazinamide, rifampicin, rifabutin, rifapentine, and streptomycin; and other compounds such as arsphenamine, chloramphenicol, fosfomycin, fusidic acid, metronidazole, mupirocin, platensimycin, quinupristin / dalfopristin, thiamphenicol, tigecycline (Bs), and tinidazole.

[0096] Particularly preferred low molecular weight antimicrobial agents (d) are octenidine, chlorhexidine and their salts, chlorhexidine digluconate, chlorhexidine diacetate, phthalimidoperoxycaproic acid (PAP) and mixtures thereof. Most preferred antimicrobial agents are chlorhexidine and its salts, chlorhexidine digluconate, chlorhexidine diacetate, and mixtures thereof. One or more antimicrobial compounds may be used.

[0097] The compositions of the present invention preferably comprise from 0.001 to 3.0% by weight, more preferably from 0.01 to 2.0% by weight, most preferably from 0.1 to 1.5% by weight of one or more low molecular weight antimicrobial compounds (d).

[0098] The compositions of the present invention may further contain an organic or inorganic fluoride source, if desired. Preferred fluorides are sodium fluoride, potassium fluoride, ammonium fluoride, ammonium difluoride, sodium monofluorophosphate, potassium monofluorophosphate, ammonium hexafluorosilicate, magnesium hexafluorosilicate, potassium hexafluorosilicate, ammonium hexafluorotitanate, ammonium hexafluoroaluminate, zirconium fluoride, tetra-n-butylammonium dihydrogen trifluoride (TBAF-3), rubidium fluoride, cesium fluoride, potassium bifluoride (KHF2), silver(I) fluoride, tin(II) fluoride, and the fluorinated amines Olaflur (N,N,N'-tris(2-hydroxyethyl)-N'-octadecyl-1,3-diaminopropane dihydrogen fluoride) and Dectaflur (9-octadecenylamine bifluoride). Particularly preferred fluorides are ammonium fluoride, ammonium difluoride, sodium fluoride, potassium fluoride, and tetra-n-butylammonium dihydrogen trifluoride (TBAF-3). The fluoride is preferably added to the dispersion after polymerization is complete. The composition of the present invention may contain one or more fluorides.

[0099] The compositions of the present invention preferably contain from 0 to 3.0 wt. %, more preferably from 0.16 to 3.0 wt. %, even more preferably from 0.5 to 2.5 wt. %, and most preferably from 1.0 to 2.0 wt. % of one or more organic and / or inorganic fluoride sources (F - (calculated as

[0100] Fluoride ions have been known to reduce the stability of aqueous polymer dispersions. This effect is concentration-dependent, making it difficult to prepare stable dispersions without using organic solvents with high fluoride content, which is especially required for professional use. According to the present invention, it has surprisingly been found that stable dental varnishes with high fluoride content can be prepared by using cationic polymer dispersions comprising dispersed copolymers as defined above.

[0101] The compositions of the present invention may contain one or more additional ingredients, preferably selected from humectants, oxidizing agents and other additives, such as sweeteners, colorants, flavors, pH adjusters, soothing agents, and thickeners, which are preferably added while stirring the copolymer dispersion after the polymerization is complete.

[0102] Preferred humectants are 1,2-propylene glycol, ethylene glycol, diethylene glycol, more preferably polyethylene glycol, most preferably xylitol, sorbitol, glycerol, and mixtures thereof.

[0103] Although many humectants are liquid organic compounds, they are not considered organic solvents within the meaning of the present invention and are not excluded from the claimed compositions. Unlike organic solvents, they are low-volatility, viscous liquids that do not readily evaporate at room temperature and are therefore not typically used in the preparation of dental varnishes.

[0104] Compositions of the present invention may preferably comprise from 0 to 30% by weight, more preferably from 0 to 25% by weight, most preferably from 0 to 20% by weight of one or more humectants.

[0105] Preferred oxidizing agents are hydrogen peroxide, carbamide peroxide, chloramine T (N-chloro-4-methylbenzolsulfonamide sodium), sodium chlorate, and phthalimidoperoxycaproic acid (PAP). While certain oxidizing agents, such as hydrogen peroxide, have antimicrobial effects, they are added primarily for their bleaching effect. Preferred oxidizing agents are hydrogen peroxide and carbamide peroxide.

[0106] The compositions of the present invention may preferably comprise from 0 to 30% by weight of one or more oxidizing agents, more preferably from 0 to 25% by weight, most preferably from 0 to 20% by weight.

[0107] According to a particularly preferred embodiment, the compositions of the present invention may comprise 0 to 16% by weight of one or more oxidizing agents, preferably they contain 1 to 16% by weight, more preferably 3 to 13% by weight, even more preferably 4 to 12% by weight, and most preferably 4 to 6% by weight of one or more oxidizing agents.

[0108] Preferred sweeteners are acesulfame K, advantame, aspartame, cyclamate, isomalt, saccharin, sucralose, thaumatin, neohesperidin DC, steviol glycosides, neotame, aspartame, and salts of acesulfame.

[0109] Preferred colorants are those listed in the food additives section of REGULATION (EC) No. 1333 / 2008 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 16 December 2008, numbers E100 to E180, and substances listed with the function "colorant" in INCI (International Nomenclature of Cosmetic Ingredients).

[0110] Preferred flavors are natural and artificial flavors or flavor extracts having the smell / flavor of peppermint, orange, strawberry, vanilla, melon, etc. Suitable flavors are listed in the "COMMISSION DECISION of 23 Feb. 1999 adopting a register of flavoring substances used in or on foodstuffs", made in application of Regulation (EC) No. 2232 / 96 of the European Parliament and of the Council of 28 October 1996 (1999 / 217 / EC).

[0111] Preferred pH adjusting agents are those listed in the INCI (International Nomenclature of Cosmetic Ingredients) for "buffering" function.

[0112] Preferred soothing agents are D-panthenol, bisabolol, or allantoin, and preferred thickening agents are water-soluble anionic cellulose ethers such as hydroxypropyl cellulose and hydroxyethyl cellulose.

[0113] The compositions of the present invention preferably contain one or more additives (sweeteners, colorants, flavors, pH adjusters, soothing agents, or thickeners) in a total amount of 0.01 to 10% by weight, more preferably 0.1 to 8.0% by weight, and most preferably 0.2 to 6.0% by weight.

[0114] The copolymer dispersions of the present invention are particularly suitable as dental materials, in particular for the production of therapeutic and non-therapeutic dental varnishes or coatings, specifically for reducing bacterial activity and combating biofilms on tooth surfaces. They are particularly suitable for use in methods for the treatment or prevention of dental plaque, caries, incipient caries lesions (initial caries), gum disease, periodontitis, periodontitis, peri-implantitis and / or gingivitis. The copolymer dispersions of the present invention may also be used for non-therapeutic, e.g. cosmetic, treatment or prevention of dental plaque.

[0115] For use, it is preferred to clean the tooth or areas of the teeth to be treated before applying the varnish. This removes dental tartar (calculus) and other deposits. Professional tooth cleaning is particularly preferred.

[0116] It is then preferable to dry the tooth or teeth to be treated. This can be done with cotton rolls, absorbent cotton, and, if necessary, a saliva aspirator or air syringe. Creating a dry working area can be facilitated by using a buccal retractor, which allows for free access to the tooth surface.

[0117] Next, a dental varnish is applied to the surface of at least one tooth. Preferably, the varnish is applied to the entire natural dentition to achieve full tooth treatment. However, the varnish can also be easily applied only to the specific area to be treated, especially if a professional dental cleaning has not been performed beforehand.

[0118] To apply the dental varnish, it is preferable to place a small amount in a suitable container, such as a dappen dish or similar container. Then, use a brush to apply a thin layer of dental varnish to the tooth surface, and allow it to dry, preferably for one to several minutes. Drying can be accelerated by using an air syringe. Once the varnish has dried, cotton rolls and cheek retractors, if used, may be removed. Patients are preferably advised not to eat or drink for one hour after the procedure.

[0119] The copolymer dispersions according to the invention, which also contain a fluoride source, are particularly suitable for tooth remineralization and for the treatment or prevention of caries. They are particularly suitable for use by dentists for therapeutic purposes, in particular for the treatment and prevention of white spots, dental caries and incipient caries lesions (initial caries), for hardening damaged teeth, and for the reconstruction of hard dental tissues. However, dental varnishes according to the invention can also be used for non-therapeutic dental treatment.

[0120] The composition for use as a dental varnish or coating preferably comprises: (a) 5 to 41 wt. %, preferably 7 to 35 wt. %, more preferably 15 to 30 wt. % of at least one copolymer (a) as defined above, (b) 50 to 94 wt. %, preferably 60 to 92 wt. %, more preferably 65 to 84 wt. % water; (c) 0.5 to 6.0 wt. %, preferably 0.6 to 5.5 wt. %, and more preferably 0.7 to 5.0 wt. % of at least one surfactant; (d) optionally, 0.001 to 3.0 wt %, preferably 0.01 to 2.0 wt %, more preferably 0.1 to 1.5 wt % of one or more low molecular weight antimicrobial compounds; (e) 0 to 3.0 wt. %, preferably 0.3 to 3.0 wt. %, more preferably 0.5 to 2.5 wt. %, and most preferably 1.0 to 2.0 wt. % of at least one inorganic or organic fluoride source (F - ), (f) 0 to 30% by weight, preferably 0 to 25% by weight, more preferably 0 to 20% by weight, of one or more humectants; (g) 0 to 16 wt. %, preferably 1 to 16 wt. %, more preferably 3 to 13 wt. % of one or more oxidizing agents, and (h) optionally, 0.01 to 10% by weight, preferably 0.1 to 8.0% by weight, more preferably 0.2 to 6.0% by weight of at least one additive selected from sweeteners, colorants, flavors, pH adjusters, soothing agents, thickeners, or mixtures thereof; in each case relative to the total weight of the varnish.

[0121] In a particularly preferred embodiment of the invention, the amounts of components (a) to (h) total 100%.

[0122] The invention will now be explained in more detail with reference to examples. [Example]

[0123] Example 1 General procedure for preparing copolymer dispersions by emulsion polymerization using a two-step seeded method. Step 1 (Seed Polymer Preparation): In a flask, 300 ml of water was purged with nitrogen, and 0.50 g of the ionic surfactant cetylpyridinium chloride (CPC, corresponding to 0.125 wt% of the final dispersion) and 8.40 g of a nonionic surfactant (Disponil® AFX3070; modified fatty alcohol ethoxylate; BASF SE, Ludwigshafen, Germany; corresponding to 2.0 wt% of the final dispersion) were added and stirred for 10 minutes. Next, 4.63 g of n-butyl acrylate (BuA) and 3.82 g of methyl methacrylate (MMA) were added to the solution under stirring (500 rpm). The resulting white emulsion was heated to 70° C. and stirred for 15 minutes. An initiator solution (0.60 g of 2,2'-azobisisobutylamidinium chloride (AIBA) dissolved in 12 mL of water) was added dropwise to the emulsion, and the mixture was stirred at 70°C for 30 minutes.

[0124] Step 2 (Growth Stage): A monomer mixture of 44.60 g BuA and 36.74 g MMA was added to the seed polymer through a dropping funnel under stirring (500 rpm) at 70°C over 3 hours. After addition was complete, the mixture was heated to 80°C and stirred (500 rpm) for an additional hour to yield the final (meth)acrylate copolymer latex as a white, slightly transparent dispersion D1 with the following characteristics: particle size: 50 nm, zeta potential: 23 mV, and dispersion pH: 3.5. The molar ratio of MMA to n-BuA in the copolymer was 51:49. The glass transition temperature of the copolymer with this monomer ratio was measured to be -3°C. Example 2 Preparation of a dispersion of n-butyl acrylate / methyl methacrylate copolymer particles containing cationic and nonionic surfactants (Dispersion D2)

[0125] Following the general procedure of Example 1, a seed polymer was prepared from 0.50 g of CPC (0.125 wt % of the final dispersion), 8.40 g of Tween® 20 (polyethylene glycol sorbitan monolaurate: Merck, 2.0 wt % of the final dispersion), 4.63 g of BuA, 3.82 g of MMA, 0.60 g of AIBA, and 312 mL of water.

[0126] Following the general procedure, particle growth was induced by adding a mixture of 44.60 g BuA and 36.74 g MMA. The final (meth)acrylate copolymer latex was obtained as a white, slightly transparent dispersion D2 with the following characteristics: particle size: 50 nm, zeta potential: 40 mV. The molar ratio of MMA to n-BuA was 51:49 in the copolymer. Example 3 Preparation of a dispersion of n-butyl acrylate / methyl methacrylate copolymer particles containing cationic and nonionic surfactants (Dispersion D3)

[0127] Following the general procedure of Example 1, a seed polymer was prepared from 0.50 g of CPC (0.125 wt% of the final dispersion), 16.80 g of Tween® 20 (4.0 wt% of the final dispersion), 6.22 g of BuA, 2.61 g of MMA, 0.60 g of AIBA, and 312 mL of water.

[0128] Following the general procedure, particle growth was induced by adding a mixture of 59.65 g BuA and 25.01 g MMA. The final (meth)acrylate copolymer latex was obtained as a white, slightly transparent dispersion D3 with the following characteristics: particle size: 46 nm, zeta potential: 30 mV. The molar ratio of MMA to n-BuA in the copolymer was 35:65. The glass transition temperature of the copolymer with this monomer ratio was measured to be -20°C. Example 4 Preparation of a dispersion of n-butyl acrylate / methyl methacrylate / methacrylic acid copolymer particles (Dispersion D4)

[0129] Following the general procedure of Example 1, a seed polymer was prepared from 0.50 g of CPC (0.125 wt% of the final dispersion), 8.40 g of Disponil® AFX3070 (2.0 wt% of the final dispersion), 6.54 g of BuA, 2.62 g of MMA, 0.14 g of methacrylic acid, 0.60 g of AIBA, and 312 mL of water.

[0130] Following the general procedure, particle growth was induced by adding a mixture of 59.15 g BuA, 23.49 g MMA, and 1.25 g methacrylic acid (MAA). The final (meth)acrylate copolymer latex was obtained as a white, slightly transparent dispersion D4 with a pH value of 3.7. Example 5 Preparation of a dispersion of n-butyl acrylate / styrene copolymer particles (Dispersion D5)

[0131] Following the general procedure of Example 1, a seed polymer was prepared from 0.50 g of CPC (0.125 wt% of the final dispersion), 8.40 g of Disponil® AFX3070 (2.0 wt% of the final dispersion), 4.80 g of BuA, 3.90 g of styrene, 0.60 g of AIBA, and 312 mL of water.

[0132] Following the general procedure, particle growth was induced by adding a mixture of 45.77 g of n-BuA and 37.20 g of styrene. The final acrylate / styrene copolymer latex was obtained as a white, slightly transparent dispersion D5 with the following characteristics: particle size: 40 nm. The molar ratio of styrene to n-BuA was 50:50 in the copolymer. Example 6 Preparation of dispersions of n-butyl acrylate / methyl methacrylate / ([2-(methacryloyloxy)ethyl]trimethylammonium chloride copolymer particles

[0133] Following the general procedure of Example 1, a seed polymer was prepared from 8.40 g of Disponil® AFX3070, 4.54 g of BuA, 3.96 g of MMA, 1.91 g of MATMAC solution ([2-(methacryloyloxy)ethyl]trimethylammonium chloride, 75% aqueous solution), 0.60 g of AIBA, and 225 mL of water.

[0134] Following the general procedure, particle growth was induced by adding a mixture of 40.96 g BuA and 35.59 g MMA. This monomer mixture was added simultaneously with a solution of 9.03 g MATMAC solution in 75 mL water (75% aqueous solution) over 75 minutes. The final (meth)acrylate copolymer was obtained as a white, slightly transparent dispersion. Example 7 Preparation and properties of varnishes containing the antimicrobial agent CHX.

[0135] To 9.65 g of each of Dispersions D1, D3 and D4, 0.35 g of a 20 wt % aqueous solution of chlorhexidine digluconate (CHX) (corresponding to 0.7 wt % CHX) was added with stirring.

[0136] The adhesion of films formed from the prepared varnishes to enamel was tested on bovine teeth. The bovine teeth were embedded in polymer blocks and then ground to expose the enamel. Before applying the varnish, the tooth surface was polished with sandpaper (4000 grit). A thin layer of varnish was applied with a brush (VivaBrush G, Ivoclar Vivadent AG) and then dried in a gentle airflow. The prepared test specimens were stored in water (containing a small amount of rose bengal as a pigment) for 4 hours. After drying the test specimens in a gentle airflow, the quality of the film was evaluated and the adhesion to enamel was measured semiquantitatively. For this purpose, adhesive tape (tesafilm®, tesa SE, Norderstedt, Germany) was applied to the test specimens with the exposed tooth surface. The tape was then slowly peeled off at an acute angle to the tooth. A visual evaluation of adhesion was performed. All of the prepared varnishes showed excellent adhesion to enamel. That means that little or no film could be peeled or scratched off with a metal spatula.

[0137] To examine the antimicrobial performance of CHX varnish, a zone of inhibition test was performed using Streptococcus mutans. Cultures were grown from cryobank stock cultures in 10 ml of BHI (brain heart infusion) medium. 100 μl of the culture was inoculated once into 10 ml of fresh medium. Next, 100 μl of the culture was spread onto a 9 cm diameter BHI agar plate. One side of a cylindrical ceramic test specimen with a diameter of 12.1 mm was coated with the dispersion varnish using a brush and allowed to dry for 15 minutes. The test specimen was then carefully placed, coated side down, onto the agar plate and gently pressed down. For the negative control, a ceramic test specimen was placed directly onto an uncoated agar plate. The results of the zone of inhibition test are shown in Table 1. They demonstrate a significant improvement in the antimicrobial performance of the CHX-containing varnish compared to varnishes without any added antimicrobial agents. Example 8 Preparation and antimicrobial properties of varnishes containing the antimicrobial surfactant CPC

[0138] Dispersions D1, D3, and D4 contain 0.125% by weight of the antimicrobial surfactant cetylpyridinium chloride (CPC). The antimicrobial activity of these varnishes was tested as described in Example 7.

[0139] Additional amounts of CPC were then added to Dispersions D1, D3, and D4. To 9.90 g of each of Dispersions D1, D3, and D4, 0.10 g of cetylpyridinium chloride (CPC) was added with stirring until the CPC was completely dissolved. The antimicrobial activity of varnishes containing additional amounts of CPC was also tested as described in Example 7.

[0140] The results of the zone of inhibition tests are shown in Table 1. They show that the antimicrobial activity performance of varnishes containing additional amounts of CPC was significantly improved. [Table 1]

Claims

1. (a) from 5 to 41 wt. %, preferably from 7 to 35 wt. %, more preferably from 15 to 30 wt. % of at least one copolymer; (b) 50 to 94 wt. %, preferably 60 to 92 wt. %, more preferably 65 to 84 wt. % water, and (c) 0.5 to 6.0 wt. %, preferably 0.6 to 5.5 wt. %, more preferably 0.7 to 5.0 wt. % of at least one surfactant A cationic polymer dispersion comprising: the dispersion is characterized by comprising at least one antimicrobial compound and being essentially free of low-boiling organic solvents; A cationic polymer dispersion, wherein all weight percentages are based on the total weight of the dispersion.

2. 2. The dispersion of claim 1, comprising 0.001 to 3.0 wt. %, preferably 0.01 to 2.0 wt. %, more preferably 0.1 to 1.5 wt. % of at least one low molecular weight antimicrobial compound (d).

3. The at least one copolymer (a) (a1) 5 to 70 mol %, preferably 10 to 65 mol %, more preferably 15 to 60 mol % of at least one hard (meth)acrylate or vinyl monomer, and (a2) 30 to 95 mol %, preferably 35 to 90 mol %, more preferably 40 to 85 mol % of at least one flexible (meth)acrylate or vinyl monomer; is a copolymer obtainable by free radical copolymerization of a monomer mixture comprising The at least one hard monomer has a glass transition temperature (T Ｇ ) from 30°C to 130°C, and the at least one flexible monomer is a (meth)acrylate monomer or a vinyl monomer that forms a homopolymer having a glass transition temperature (T Ｇ 2. The dispersion of claim 1, wherein the (meth)acrylate or vinyl monomer forms a homopolymer having a temperature of from -70°C to 20°C, and all mole percentages are based on the total molar amount of monomers.

4. The monomer (a1) is methyl methacrylate, phenyl(meth)acrylate, naphthyl(meth)acrylate, benzyl(meth)acrylate, adamantyl(meth)acrylate, isobornyl(meth)acrylate, 2-[(methoxycarbonyl)amino]ethyl(meth)acrylate, 2-[(propoxycarbonyl)amino]ethyl(meth)acrylate, 2-[(isopropoxycarbonyl)amino]ethyl(meth)acrylate, 2-[(butoxycarbonyl)amino]ethyl(meth)acrylate, 2-[(hexyloxycarbonyl)amino]ethyl(meth)acrylate, 2-[(cyclohexyloxycarbonyl)amino]ethyl (meth)acrylate, 2-[(benzyloxycarbonyl)amino]ethyl (meth)acrylate, 2-[(ethylcarbamoyl)oxy]ethyl (meth)acrylate, 2-[(propylcarbamoyl)oxy]ethyl (meth)acrylate, 2-[(isopropylcarbamoyl)oxy]ethyl (meth)acrylate, 2-[(hexylcarbamoyl)oxy]ethyl (meth)acrylate, 2-[(benzylcarbamoyl)oxy ]ethyl (meth)acrylate, 2-[(2-tetrahydrofurfuryloxycarbonyl)amino]ethyl (meth)acrylate, 2-[(2-oxo-1,3-dioxolan-4-yl)methoxycarbonylamino]ethyl (meth)acrylate, (meth)acrylic acid 2-(furan-2-yl-methoxycarbonylamino)ethyl ester, (1,3-dioxolan-2-one-4-yl)methyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, 2-(o-biphenyloxy)ethyl (meth)acrylate, 2-hydroxy -3-phenoxypropyl (meth)acrylate, 2-phenoxypropyl (meth)acrylate, 2-(p-cumylphenoxy)ethyl (meth)acrylate, tricyclodecane (meth)acrylate, tricyclodecane methyl (meth)acrylate and 1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl (meth)acrylate, styrene, p-methylstyrene, p-ethylstyrene, p-methoxystyrene, α-methylstyrene, divinylbenzene, acrylonitrile or mixtures thereof; and / or 4. Dispersion according to claim 3, wherein the monomer (a2) is selected from alkyl (meth)acrylates or cycloalkyl (meth)acrylates, n-butyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-dodecyl methacrylate, tetradecyl methacrylate, hexadecyl methacrylate, the corresponding acrylates, hydroxyalkyl (meth)acrylates, 2-hydroxyethyl acrylate, 2-octyl acrylate, 2-hydroxypropyl acrylate, vinyl acetate, vinyl esters of saturated monocarboxylic acids having a highly branched structure and having 5 to 12, preferably 9 or 10, carbon atoms, vinyl esters of neodecanoic and neononanoic acid, or mixtures thereof.

5. 5. The dispersion of claim 4, wherein the monomer (a1) is selected from methyl methacrylate, benzyl methacrylate, styrene, or a mixture thereof, and the monomer (a2) is selected from n-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, or a mixture thereof.

6. 4. The dispersion of claim 3, wherein the monomer mixture comprises, in addition to monomer (a1) and monomer (a2), at least one additional radically polymerizable monomer selected from basic nitrogen-containing monomers, cationic monomers, zwitterionic monomers, antimicrobial monomers and / or adhesive monomers.

7. The weight average molar mass (M Ｗ 2. The dispersion of claim 1, wherein the molecular weight of the polymer is from 100 to 18,000 kDa, preferably from 200 to 5,000 kDa, more preferably from 250 to 3,000 kDa.

8. 2. The dispersion of claim 1, wherein the number average particle size of the copolymer (a) is in the range of 5 nm to 900 nm, preferably 30 to 300 nm.

9. The copolymer (a) is (I) Free radical emulsion polymerization of a mixture of monomers (a1) and (a2) in the presence of a cationic surfactant. (II) Free radical emulsion polymerization of monomer (a1) and monomer (a2) using a radical initiator having a cationic group in the presence of a cationic surfactant or preferably a nonionic surfactant. (III) free radical emulsion polymerization of a mixture of monomer (a1), monomer (a2) and at least one cationic monomer in the presence of a cationic surfactant or preferably a nonionic surfactant, or (IV) free radical emulsion polymerization of a mixture of monomer (a1), monomer (a2) and at least one basic nitrogen-containing monomer in the presence of a cationic surfactant or preferably a nonionic surfactant, followed by protonation of the nitrogen-containing monomer units with an acid.

2. The dispersion of claim 1, wherein the copolymer is obtainable from

10. 2. The dispersion of claim 1, wherein the at least one surfactant is selected from the group consisting of nonionic surfactants, cationic surfactants, amphoteric surfactants, and polymeric surfactants, preferably nonionic surfactants, and mixtures of cationic surfactants, amphoteric surfactants, and polymeric surfactants with nonionic surfactants.

11. 10. The dispersion of claim 1, comprising at least one antimicrobial surfactant selected from cetylpyridinium tetrachlorozinc salt, octenidine dihydrochloride, cetylamine hydrofluoride (Hetaflur), cetylamine hydrochloride, dodecyltrimethylammonium chloride, and cetylpyridinium chloride, and / or at least one low molecular weight antimicrobial agent selected from octenidine, chlorhexidine and salts thereof, chlorhexidine digluconate, and chlorhexidine diacetate.

12. 10. The dispersion of claim 1, further comprising at least one additional ingredient selected from an organic or inorganic fluoride source, a humectant, an oxidizing agent, a sweetener, a colorant, a flavor, a pH adjuster, a soothing agent, and a thickener.

13. (a) from 5 to 41 wt. %, preferably from 7 to 35 wt. %, more preferably from 15 to 30 wt. % of at least one copolymer; (b) 50 to 94 wt. %, preferably 60 to 92 wt. %, more preferably 65 to 84 wt. % water; (c) 0.5 to 6.0 wt. %, preferably 0.6 to 5.5 wt. %, and more preferably 0.7 to 5.0 wt. % of at least one surfactant; (d) 0.001 to 3.0 wt. %, preferably 0.01 to 2.0 wt. %, more preferably 0.1 to 1.5 wt. % of one or more low molecular weight antimicrobial compounds; (e) 0 to 3.0 wt. %, preferably 0.3 to 3.0 wt. %, more preferably 0.5 to 2.5 wt. %, and most preferably 1.0 to 2.0 wt. % of at least one inorganic or organic fluoride source (F － (calculated as) (f) 0 to 30% by weight, preferably 0 to 25% by weight, more preferably 0 to 20% by weight, of one or more humectants; (g) 0 to 16 wt. %, preferably 1 to 16 wt. %, more preferably 3 to 13 wt. % of one or more oxidizing agents; and (h) 0.01 to 10% by weight, preferably 0.1 to 8.0% by weight, more preferably 0.2 to 6.0% by weight of at least one additive selected from sweeteners, colorants, flavors, pH adjusters, soothing agents, thickeners, or mixtures thereof. Including, All weight percentages are based on the total weight of the dispersion. The dispersion of claim 12.

14. 14. A dispersion according to any one of claims 1 to 13 for use in a method for the treatment or prevention of dental plaque, caries, incipient caries lesions (early caries) gum disease, periodontal disease, periodontitis, peri-implantitis and / or gingivitis.

15. 14. A composition comprising a dispersion according to any one of claims 1 to 13 for use in a method of therapeutic or non-therapeutic dental treatment, said method comprising: (i) optionally cleaning the tooth or teeth to remove tartar or other deposits; (ii) optionally drying the tooth or teeth; (iii) applying the dispersion to at least one tooth surface; and (iv) drying the applied dispersion A composition comprising:

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