| PATENT ASSIGNEE'S COUNTRY | Japan |
| UPDATE | 04.00 |
| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | 11.04.00 |
| PATENT TITLE |
Coating composition for teeth |
| PATENT ABSTRACT |
The present invention relates to a dental coating composition comprising a polymer which has in its molecule one or more phosphorus series acid residues selected from the group consisting of phosphoric acid, phosphonic acid and phosphinic acid and halides and salts thereof and has a weight-average molecular weight of 10,000 to 5,000,000, and water or a lower alcohol. The composition is a dental coating agent which does not easily peel off when drinking or eating, can be removed easily if necessary and does not have a safety problem. |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | 17.08.98 |
| PATENT CT FILE DATE | 10.12.97 |
| PATENT CT NUMBER | This data is not available for free |
| PATENT CT PUB NUMBER | This data is not available for free |
| PATENT CT PUB DATE | 25.06.98 |
| PATENT FOREIGN APPLICATION PRIORITY DATA | This data is not available for free |
| PATENT REFERENCES CITED | This data is not available for free |
| PATENT CLAIMS |
We claim: 1. A dental coating composition, comprising (a) a polymer of polymerized vinyl monomers which has in a molecule thereof one or more phosphorus series acid residues selected from the group consisting of phosphoric acid, phosphonic acid and phosphinic acid, and halides and salts thereof and has a weight-average molecular weight of 10,000 to 5,000,000; and (b) a saturated C.sub.1-5 alcohol or a mixture of water and a saturated C.sub.1-5 alcohol, wherein the amount of said polymer (a) soluble in 100 g of anhydrous ethanol at 20.degree. C. is at least 1 g, and wherein said polymer (a) is a homopolymer or copolymer having a structural unit represented by the following formula (11): ##STR19## wherein R.sup.1 represents a hydrogen atom or a hydrocarbon group which may be substituted by a fluorine atom, X represents an alkylene, COOR.sup.1 --, CON(R)R.sup.1 -- or COO((CH.sub.2).sub.m O).sub.n R.sup.3 -- group, in which R.sup.2 represents a hydrogen atom or a C.sub.1-5 hydrocarbon group, m is 1 to 10, n is 1 to 30 and R.sup.3 represents a C.sub.1-20 divalent hydrocarbon group which may be substituted by a hydroxy, alkoxy or aryloxy group, and Y represents a phosphorus series acid residue selected from the group consisting of phosphoric acid, phosphonic acid and phosphinic acid. 2. A composition according to claim 1, wherein said polymer (a) is a polymer having a residue of phosphoric acid or a salt thereof. 3. A composition according to claim 1, wherein said polymer (a) has, as a main chain, a chain obtained by polymerization of a polymerizable vinyl group and, as a side chain, one or more phosphorus series acid residues selected from the group consisting of phosphoric acid, phosphonic acid and phosphinic acid, and halides and salts thereof. 4. A composition according to claim 1, wherein the phosphorus atom content in said polymer (a) is 0.0001 to 35 wt. %. 5. A composition according to claim 1, which has a viscosity of 2 to 200 cp. 6. A composition according to claim 1, wherein said polymer (a) is a copolymer of a polymerizable monomer containing in a molecule thereof one or more phosphorus series acid residues selected from the group consisting of phosphoric acid, phosphonic acid and phosphinic acid, and halides and salts thereof; and a polymerizable monomer free from said phosphorus series acid residue. 7. A composition according to claim 1, wherein said polymer (a) is a homopolymer or copolymer having a structural unit represented by the following formula (12): ##STR20## wherein R.sup.4 represents a hydrogen atom or a methyl group and l stands for an integer of 1 to 15. 8. A composition according to claim 1, further comprising a pigment selected from the group consisting of titanium on mica, fish scale leaves and shell powders. 9. A composition according to claim 8, wherein the pigment content is 0.01 to 10 wt. %. 10. A dental coating method, which comprises applying a composition as claimed in claim 1 to a tooth. 11. A composition according to claim 1, consisting essentially of defined components (a) and (b). -------------------------------------------------------------------------------- |
| PATENT DESCRIPTION |
TECHNICAL FIELD The present invention relates to a dental coating composition, particularly a coating composition used for beautifying teeth. BACKGROUND ART Manicure and pedicure, as for cosmetic care of hands and fingernails and feet, are widely enjoyed by females. In recent years, cosmetic care of teeth has also become popular. This kind of dental care is generally carried out by applying a dye- or pigment-containing composition to teeth. Use of a dental adhesive is one example of a technique for applying a composition to teeth. Specifically, a monomer or the like is applied to the teeth, followed by polymerization in a short time by ultraviolet irradiation or heating (ex. Japanese Patent Application Laid-Open No. SHO 53-69494 and Japanese Patent Application Laid-Open No. SHO 52-113089). Considering the use, the above-described dental adhesive has a high adhesion strength such that it does not peel off from the teeth for a long period of time. For the purpose of dental beautification, on the other hand, the composition must have a proper adhesion strength such that it does not peel off easily during drinking or eating, but it can be removed easily if necessary. Since the above-described dental adhesive is polymerized in a short time using ultraviolet irradiation or the like, it impossible to control the adhesion strength or coating degree. In addition, the above-described monomer involves a safety problem so it is often inappropriate to use the monomer for dental care at home. An object of the present invention is therefore to provide a dental coating composition which does not peel off easily when drinking or eating, has a proper adhesion strength such that it can be removed easily if necessary and is highly safe in use. DISCLOSURE OF THE INVENTION In view of the forgoing circumstances, the present inventors have carried out an extensive investigation. As a result, it has been found that a dental coating composition comprising a polymer which has in its molecule a phosphorus series acid residue such as phosphoric acid and has a pre-determined weight-average molecular weight; and a specific solvent has an appropriate adhesion strength when applied to teeth, beautifies the teeth by imparting gloss or the like and is excellent in safety, leading to the completion of the invention. In one aspect of the present invention, there is thus provided a dental coating composition comprising (a) a polymer which has in its molecule one or more phosphorus series acid residues selected from the group consisting of phosphoric acid, phosphonic acid and phosphinic acid, and halides and salts thereof and has a weight-average molecular weight of from 10,000 to 5,000,000; and (b) water or a C.sub.1-5 alcohol. In another aspect of the present invention, there is also provided a dental coating process, which comprises applying the above dental coating composition to teeth. In a further aspect of the present invention, there is also provided the use of the above-described polymer (a) for the dental coating. BEST MODES FOR CARRYING OUT THE INVENTION The polymer (a) usable in the present invention has, in its molecule, one or more phosphorus series acid residues selected from the group consisting of phosphoric acid, phosphonic acid and phosphinic acid, and halides and salts thereof and has a weight-average molecular weight of 10,000 to 5,000,000. Examples of the phosphoric acid residue contained in the polymer (a) include phosphate and diphosphate groups, each having at least one hydroxyl group, such as a phosphoric acid residue (1), phosphoric acid monoester residue (2), diphosphoric acid residue, (3) diphosphoric acid monoester residue (4) and diphosphoric acid diester residue (8) (each of the bonds in the below-described formulas (1) to (10) is bound to an atom other than oxygen, preferably, a carbon, nitrogen or sulfur atom, more preferably a carbon atom). ##STR1## Examples of the phosphonic acid residue include phosphonate or diphosphonate groups each having at least one hydroxyl group, such as a phosphonic acid residue (6), phosphonic acid monoester residue (7), diphosphonic acid residue (8) and diphosphonic acid monoester residue (9). ##STR2## Examples of the phosphinic acid residue include a phosphinic acid series residue (phosphinate group) (10). ##STR3## As the salt of such a residue, preferred are alkali metal salts such as sodium and potassium salts. Examples of the halide of such a residue include the groups of the above-described formulas (1) to (10) each of which has one or more hydroxyl groups substituted by a like number of chlorine atoms, bromine atoms, fluorine atoms or the like. Among the groups of the above formulas (1) to (10), phosphoric acid residues [(1)-(5)] and salts thereof are more preferred from the viewpoints of appropriate adhesion strength and safety, with the phosphoric acid residue of the formula (1) and salt thereof are particularly preferred. As the polymer (a), particularly preferred are those which have as a main chain a chain obtained by the polymerization of a polymerizable vinyl group and as a side chain the above-described phosphoric acid residue. The polymer (a) may has as the side chain a group other than the above-described phosphoric acid residue. Described specifically, it may have as a side chain one or more of a carboxyl group and salts thereof, a sulfonic acid group and salts thereof, and saturated or unsaturated hydrocarbon groups which may be substituted by a hydroxyl group, amide group or fluorine. The polymer (a) is preferred to have a phosphorus atom content of 0.0001 to 35 wt. %, particularly 0.1 to 10 wt. %. By incorporating the phosphorus series acid residue to give a phosphorus atom content in the polymer (a) to 0.0001 to 35 wt. %, a dental coating composition having more appropriate adhesion strength is available. Phosphorus atom contents less than 0.0001 wt. % do not bring about sufficient adhesion strength. When the content exceeds 35 wt. %, on the other hand, the composition happens to soften in the oral cavity. As the polymer (a) used in the present invention, preferred is a homopolymer or copolymer having a structural unit represented by the following formula (11): ##STR4## wherein R.sup.1 represents a hydrogen atom or a hydrocarbon group which may be substituted by a fluorine atom, X represents an alkylene, COOR.sup.3 --, CON(R.sup.2)R.sup.3 -- or COO [(CH.sub.2).sub.m O].sub.n R.sup.3 -- group, in which R.sup.2 representing a hydrogen atom or a C.sub.1-5 hydrocarbon group, m standing for 1 to 10, n standing for 1 to 30, R.sup.3 representing a divalent C.sub.1-20 hydrocarbon group which may be substituted by a hydroxy, alkoxy or aryloxy group, and Y represents the above-described phosphorus series acid residue. In the above formula (11), COOR-- and COO[(CH.sub.2).sub.m O].sub.n R.sup.3 -- groups are preferred as X. Examples of the divalent hydrocarbon group represented by R.sup.3 include linear or branched alkylene groups, divalent cycloalkyl groups and phenylene groups and combinations thereof. The phosphorus series acid residue represented by Y in the above formula (11) may be esterified with a C.sub.1-20 hydrocarbon group (ex. alkyl, phenyl or the like). As the polymer (a), particularly preferred is a homopolymer or copolymer having a structural unit represented by the following formula (12): ##STR5## wherein R.sup.4 represents a hydrogen atom or a methyl group and l stands for an integer of 1 to 15. The weight-average molecular weight of the polymer (a) used in the present invention is 10,000 to 5,000,000, preferably 10,000 to 2,000,000, more preferably 15,000 to 1,000,000 and particularly preferably 20,000 to 1,000,000. When the weight-average molecular weight is less than 10,000, the strength of the formed film becomes low. When it exceeds 5,000,000, the polymer has poor solubility in a solvent and too high viscosity, which makes it difficult to treat the polymer. Furthermore, the amount of the polymer (a) soluble in 100 g of anhydrous ethanol at 20.degree. C. is preferably 1 g or greater, more preferably 5 g or greater and particularly preferably 10 g or greater. When the amount of the polymer soluble in 100 g of anhydrous ethanol at 20.degree. C. is 1 g or greater, it becomes possible to prepare an easily applicable composition. The polymer (a) can be obtained by polymerizing one or more monomers which contain the above-described phosphorus series acid residue or said monomer(s) and a monomer free from such a phosphorus series acid residue (said monomer will hereinafter be called "non-phosphorus series monomer"). The polymerization process differs depending on the monomer to be employed, but ordinary radical polymerization can be adopted. Although no particular limitation is imposed on the above-described phosphorus-series-acid-residue-containing monomer insofar as it contains a polymerizable vinyl group as the main chain and the phosphorus series acid residue as the side chain, a monomer [CH.sub.2 .dbd.C(R.sup.1)--X--Y] forming a structural unit of the above formula (11) is more preferred, with a (meth)acrylate having the phosphorus series acid residue as the side chain being particularly preferred. As the above-described phosphorus-series-acid-residue-containing monomer, particularly preferred ones will be exemplified below: ##STR6## wherein R.sup.4 represents a hydrogen atom or a methyl group, a stands for an integer of 2 to 40 and Z represents a halogen atom. Among these monomers, those represented by the following formula (13): ##STR7## wherein R.sup.2 represents a hydrogen atom or a methyl group and l stands for an integer of 1 to 15 are most preferred. Examples of the non-phosphorus series monomer copolymerizable with any one of the above-exemplified phosphorus-series-acid-residue-containing monomers include (meth)acrylic acid, (meth)acrylate, (meth)acrylamide, vinyl carboxylate, styrene monomer, vinylpyridine, vinylpyrrolidone, maleimide monomer and unsaturated fatty acid monomer. In addition, 2-methacryloyloxyethyltrimethylammonium chloride and 2-acryloyloxypropylhydrogen phthalate can also be given as examples. Among the above-described non-phosphorus series monomers, preferably employed are one or more of (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isobornyl (meth)acrylate, cetyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, dodecyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, (meth)acrylic diethylene glycol ethoxylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, phenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dimethylacrylamide, N-[3-(dimethylamino)propyl]acrylamide, diacetone acrylamide, cyclohexyl (meth)acrylate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl caproate, vinyl octylate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl neodecanoate, styrene, 2-methylstyrene, .alpha.-methylstyrene dimer, 2-vinylpyridine, 4-vinylpyridine, N-vinyl-2-pyrrolidone, N-phenylmaleimide, N-(2-chlorophenyl)maleimide, N-laurmaleimide and N-cyclohexylmaleimide. Although no particular limitation is imposed on the mixing ratio of phosphorus-series-acid-residue-containing monomer to non-phosphorus series monomer in the copolymer used in the invention, the former monomer is preferably added in an amount of 0.01 to 40 mol %, particularly 0.1 to 20 mol %. Water or a C.sub.1-5 alcohol (b) to be incorporated in the composition of the present invention is a solvent having good affinity with the above-described polymer. Examples of the alcohol include linear or branched saturated alcohols having 1 to 5 carbon atoms. Among them, ethanol and isopropyl alcohol are preferred, with ethanol being particularly preferred. At least two of the solvents selected from water and C.sub.1-5 alcohols may be used in combination. It is preferred that the solvent be added in an amount of 30 to 98 wt. %, particularly 50 to 95 wt. % in the whole composition. The dental coating composition of the present invention is preferred to have a viscosity of 2 to 200 cp, particularly 5 to 50 cp when it is applied to teeth. If the viscosity is less than 2 cp, there is a possibility of the composition dripping in or outside the mouth. If the viscosity is greater than 200 cp, on the other hand, the composition does not spread well, which makes it difficult to apply the composition uniformly to the surface of the teeth. The viscosity of the composition as used herein is measured by a Brookfield type viscometer at 20.degree. C. To the dental coating composition of the present invention, a pigment can be added in order to make teeth look white, color the teeth or impart it with gloss. Examples of the pigment include titanium mica, fish scale leaves and shell powders. Among them, titanium mica is preferred because it imparts teeth with aesthetic appearance and gloss, flattens the coating unevenness and color can be changed by controlling the film thickness of the titanium on mica. Such a pigment is preferred to be added in the powdery form so that it can be uniformly dispersed in the dental coating composition easily. The pigment is added to the coating composition preferably in an amount of 0.1 to 10 wt. %, more preferably 0.2 to 5 wt. %. To the composition of the present invention, various powders can be added further as needed. Examples include .alpha.-quartz, silica, alumina, hydroxyapatite, calcium carbonate, fluoroaluminosilicate glass, barium sulfate, titanium oxide, zirconia, glass and ultra-fine-particle silica and organic complex powder containing both organic and inorganic components. Examples of the glass include, silica glass, sodium quartz silicate glass, borosilicate glass, barium glass, strontium glass, zinc glass, lanthanum glass, yttrium glass, barium boroaluminosilicate glass, alumina silicate glass, strontium boroaluminosiliate glass, synthetic silica and titanium silicate glass. To the composition of the present invention, a copolymer between polymethyl methacrylate or methyl methacrylate and a crosslinkable monomer, or a powdery polymer such as polystyrene or polyvinyl chloride is also added as needed. To the dental coating composition of the present invention, orally usable various components can be added within an extent not impairing the advantages of the present invention. Examples of such components include tooth quality reinforcing agents such as sodium monofluorophosphate, tin fluoride and sodium fluoride; bactericides such as chlorhexidine and salts thereof, triclosan, cetylpyridinium chloride, isopropylmethylphenol, benzethonium chloride and benzalkonium chloride; pH regulators such as sodium phosphate, KOH and NaOH; enzyme preparations such as dextranase, amylase, protease, lysozyme and mutanase; anti-inflammatory agent blood circulation accelerator such as sodium chloride, hinokitiol, .epsilon.-aminocaproic acid, tranexamic acid, allantoin derivatives, tocopherol derivatives, octyl phthalide, nicotinic acid esters, dihydrocholesterol, glycyrrhetic acid, glycyrrhizic acid and salts thereof, glycerophosphate, chlorophyll, water-soluble inorganic phosphoric acid compounds, azulene derivatives, matricaria, Japanese green gentian, toki, cnidii rhizoma and other herbal and crude drugs; sweeteners such as saccharin sodium, stevioside, thaumatin and aspartylphenylalanine methyl ester; antiseptics such as p-hydroxybenzoic acid, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butyl p-hydroxybenzoate and sodium benzoate; colorants.multidot. coloring matters such as titanium dioxide; flavoring agents such as peppermint oil, spearmint oil, menthol, carvone, anethole, eugenol, methyl salicylate, limonene, ocimene, n-decyl alcohol, citronellol, .alpha.-terpineol, methyl acetate, citronellyl? acetate, methyl eugenol, ceneole, linalool, ethyl linalool, vanillin, thymol, anise oil, lemon oil, orange oil, sage oil, rosemary oil, cinnamon oil, pimento oil, laurel oil, beefsteak plant oil, methyl salicylate, clove oil and eucalyptus oil. The dental coating composition of the present invention can be prepared, for example, by mixing the above-described polymer (a) and solvent (b) and, in addition, a thickener such as ethyl cellulose, hydroxypropylcellulose or carboxyvinyl polymer and a pigment such as titanium mica, fish scale leaves or shell powders as needed. It is necessary to select the thickener or pigment which is not harmful to the human body even when mistakenly ingested. The dental coating composition of the present invention can be adhered to teeth by applying it to the teeth and then evaporating the solvent component from the composition. The composition adhered to the teeth can be removed easily by ethanol or the like. |
| PATENT EXAMPLES | This data is not available for free |
| PATENT PHOTOCOPY | Available on request |
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