JPS6323168B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an oral composition containing a pigment concealed by an inorganic powder, and more specifically, the present invention relates to an oral composition containing a pigment concealed by an inorganic powder, and more specifically, a composition obtained by coating particles consisting of a pigment and a water-insoluble or poorly water-soluble polymer substance with an inorganic powder. By blending the particles, the inorganic powder coating layer collapses during brushing to reveal the pigment, thereby changing the color of the oral composition and allowing the user to sense the end of brushing. Regarding the composition. Conventionally, when brushing, it is generally difficult to judge the number of times or time required to clean the teeth.
The reality is that there is no guideline as to how long it is enough to brush, and it usually depends on the feelings and habits of each person brushing their teeth. To this end, conventionally, fine particles containing micro-encapsulated discoloration ingredients are mixed into toothpaste and brushed a certain number of times or for a certain period of time, thereby destroying the microcapsule film and discoloring the toothpaste.
A color-changing toothpaste has been proposed in which the end point of brushing can be detected by this method (Japanese Patent Application Laid-Open No. 1983-1999-
1737), but this type of toothpaste had a problem in that the discoloration in water was unclear, and its effectiveness was not fully demonstrated. In addition, sodium chloride is contained in the oral composition at a level higher than its saturation solubility, and salt-coated grains coated with sodium chloride are added to the discoloration component, so that the chloride that exists in the oral composition in a supersaturated state due to saliva during use is added. By dissolving sodium and sodium chloride that forms the coating layer of salt-coated grains,
An oral composition has also been proposed in which the discoloration component is eluted from the salt grains to discolor the toothpaste, thereby allowing the end point of brushing to be detected (Japanese Patent Application Laid-Open No. 153709/1983), but this method is It has problems such as being applicable only to toothpastes with high sodium chloride concentrations. In view of the above circumstances, the present inventors have conducted extensive research into an oral composition that can be applied to regular tooth brushing and that changes color after a desired period of brushing so that the end point of brushing can be reliably sensed.
The above purpose can be effectively achieved by incorporating into the oral composition a surface-coated pigment obtained by coating particles consisting of a pigment and a specific insoluble or poorly water-soluble polymer substance with an inorganic powder. The inventors have discovered that this can be achieved, and have come up with the present invention. That is, methods for covering the surface of the pigment and hiding the pigment include a method of attaching an inorganic powder to another pigment (core material) in a layered manner, and a method of covering the pigment (core material) with a film of a polymeric material. You could think so. There are various methods for attaching inorganic powder to the surface of the former, but in all of these methods, a film of inorganic powder is not formed, and the purpose is to hide the apparent color due to diffused reflection of light. Even if it is attached, it is difficult to sufficiently hide the color of the dye due to various factors such as the particle size and particle size distribution of the inorganic powder, the micro-uniformity of surface adhesion, and the adhesion strength. For example, the powder bed method, in which a solution or dispersion of a dye is dropped onto an inorganic powder to coat the surface, results in uneven coating and the color of the dye appears in some areas, making it impossible to achieve the purpose of the coating. There is also a method of coating the dye by spraying a solution or dispersion of an inorganic powder, but with this method it is difficult to obtain reproducible operating conditions for uniformly coating the surface. Furthermore, compared to the above-mentioned methods, there are two methods: applying frictional force to the pigment to charge it and attaching an inorganic powder with an opposite charge, or using the surface energy generated when the particles are crushed to attach the inorganic powder. However, it is not easy to uniformly charge individual particles or give them surface energy.
Advanced technology is required to achieve sufficient macroscopic color hiding, and it is difficult to obtain a coating layer that is practically sufficient. On the other hand, the latter method of hiding the color by forming a film of a polymer substance on the surface of the pigment involves dispersing the pigment in a solution of a polymerizable monomer and causing a polymerization reaction on the surface of the pigment to form a film. Using the interfacial polymerization method, pigments are dispersed in gelatin or gum arabic solution.
Phase separation method (coacervation method) in which a film-forming polymer substance is precipitated on the dye surface by adjusting the temperature or pH, and the dye is dispersed in an aqueous solution of a polymer substance that is insolubilized by polyvalent metal ions such as alginic acid. There are methods such as dropping it dropwise into an aqueous solution containing polyvalent metal ions to form a cured film, but the surface coating pigments obtained by these methods all have a surface polymer substance film formed. In addition to being thin, the surface polymeric substance coating layer usually has a weak hiding power, so it only reduces the color tone of the dye.
If particles such as these, in which the color of the pigment is not sufficiently concealed, are added to toothpaste, the aesthetic value of the toothpaste is lost due to color mixing, and the change in color of the toothpaste due to brushing becomes unclear. Furthermore, the surface-coated pigments obtained by these methods have weak adhesion strength of the inorganic powder to the pigment, or the surface coating layer is thin and weak in strength.
Brushing immediately destroys or disintegrates these surface coating layers, resulting in a color change before sufficient brushing is performed. Discoloration toothpaste that causes discoloration during brushing and indicates the end of brushing by this discoloration is characterized by making it possible to sense that the inside of the oral cavity has been sufficiently cleaned. After brushing for 3 minutes, the color should clearly change to signal the end of brushing, but since the discoloration occurs in a short time with the toothpaste containing the above-mentioned surface coating pigment, it is not possible to reliably control the brushing time. It's something that doesn't exist. On the other hand, surface-coated pigments obtained by coating particles consisting of a pigment and a specific water-insoluble or slightly water-soluble polymer substance described below with an inorganic powder,
A coating layer of opaque inorganic powder is reliably formed on the particles, and the color of the pigment is reliably hidden by this inorganic powder layer, and the adhesion of this powder layer to the particles consisting of the pigment and the polymeric substance is improved. It has strong strength, and therefore, oral compositions containing this surface coating pigment sufficiently hide the color of the pigment, so it does not interfere with the appearance of the toothpaste, and the aesthetic value of the toothpaste is maintained. Only after sufficient brushing, the inorganic coating layer collapses and changes color, allowing us to sense the end of brushing, so that the brushing time can be reliably controlled. The present invention will be explained in more detail below. The oral composition according to the present invention contains surface-coated particles in which the surfaces of particles consisting of a pigment and a specific water-insoluble or slightly water-soluble polymer substance to be described later are coated with an inorganic powder. It is used as a toothpaste. Here, as the dye, inorganic and organic dyes that are substantially insoluble in water are used, and examples thereof include the following. (a) Inorganic pigments: zinc white, yellow iron oxide, cobalt green, cobalt violet, cobalt blue, titanium oxide, gypsum, cerulean blue, chalk, red iron oxide, barium sulfate, barium titanate, mica, etc. (b) Organic pigments : Tar-based lake pigments such as Red No. 2 and Blue No. 1, etc. (c) Metallic pigments: Zinc powder, aluminum powder, copper powder,
Nickel powder, brass powder, stainless steel powder, etc. (d) Inorganic colloidal pigments: Partial hydrolysates of various sols such as silica sol, alumina sol, iron sol, nickel sol, hydrous oxides, etc., (e) Vat dyes: Red 226 No., Blue No. 201, Blue No. 204
These dyes may be used alone or in combination of two or more. Further, in the present invention, as the water-insoluble or poorly water-soluble polymeric substance to be mixed with the dye, one or more of the following (A) to (C) are used. (A): Gel-forming polyvinyl alcohol with a saponification degree of 85% or more and a polymerization degree of 500 or more. (B): Solubility parameter value (SP value) is
Ethylcellulose, nitrocellulose, polyacrylic acid esters, polyvinyl acetate, polyvinyl chloride and polyacrylonitrile having a molecular weight of 9.4 or higher. (C): A copolymer of a monomer selected from acrylic esters, vinyl acetate, vinyl chloride, and acrylonitrile and a monomer selected from olefins and styrene, each having a solubility parameter value of 9.5 or more. Here, polyvinyl alcohol with a low degree of saponification or a low degree of polymerization will reduce the hiding power of the dye, and will also reduce the adhesion strength of the inorganic powder layer, causing the inorganic powder layer to easily collapse during brushing. This causes the color of the dye to develop immediately. Further, examples of the copolymer (C) include ethylene-vinyl acetate copolymer, styrene-acrylonitrile copolymer, and the like. Furthermore, as the inorganic powder, one that is substantially insoluble in water is selected. Further, the color of the inorganic powder may be any color as long as it is different from the color of the pigment. Specifically, inorganic powders include titanium oxide, silicon oxide, barium sulfate, barium carbonate, calcium phosphate, calcium carbonate, magnesium phosphate, magnesium carbonate, talc, sericite, kaolin, montmorillonite, acid clay, zirconium silicate, and oxide. One or more of zirconium, red iron oxide, yellow iron oxide, black iron oxide, calamine, etc. can be used. The average particle size of these inorganic powders is 0.01~
It is preferably 50 μm, particularly 0.1 to 5 μm. A method for producing a surface-coated pigment using the above-mentioned pigment, polymeric substance, and inorganic powder involves kneading the pigment and a polymeric substance solution, and pulverizing or pulverizing this kneaded product to a high speed. Preferably, a method is employed in which an inorganic powder is added and mixed, and the surface of the pulverized mixture is coated with the inorganic powder to form an inorganic powder coating layer. In this case, when using gel-forming polyvinyl alcohol as the polymer substance, the polyvinyl alcohol is heated and dissolved in water, and after cooling, the dye is added and thoroughly kneaded, and the inorganic powder is further added to this kneaded mixture. When using a hydrophobic polymer material with water-affinity polar groups as the polymer material, gelling or dissolving it using a non-aqueous polar solvent is effective. An effective method is to further mix a kneaded product obtained by kneading the pigment with an inorganic powder and pulverize the mixture. In the above-mentioned surface-coated pigment, the polymer substance acts as a binder for the pigment and also allows the inorganic powder to adhere uniformly and firmly, so the color of the pigment is reliably hidden by the inorganic powder, and this can be used as an oral composition. The color of the pigment does not appear even when blended into the powder, so the appearance of the composition is not impaired.Also, the inorganic powder layer closely covers the pigment and polymer particles, but it is difficult to maintain adequate physical strength. By applying this, this inorganic powder layer collapses and the color of the pigment is developed. The amounts of pigments, polymeric substances, and inorganic powders used vary depending on the type of each component used and the number of minutes after the start of brushing to collapse the inorganic powder layer and develop the color of the pigment. However, for particles consisting of a dye and a polymeric substance, the mixing ratio of the dye and the polymeric substance is 1:0.01 to 1:5.
(weight ratio), and the ratio of this particle to inorganic powder is
Preferably, the ratio is 100:1 to 1:50 (weight ratio). In addition, the average particle size of the surface-coated pigment is 1 μm to 2 μm.
mm, particularly preferably 10 to 100 μm. The above-mentioned surface coating pigment is uniformly blended into the oral composition, but in this case, the color of the composition may be any color as long as it is different from the color of the pigment.
The composition may also be transparent, translucent, or opaque. Furthermore, the color of the inorganic powder may be the same as or different from the color of the composition. The amount of the surface coating pigment in the oral cavity composition is preferably 0.05 to 5%, particularly 0.1 to 1%. As other components of the present invention, appropriate components are used depending on the type of oral composition. For example, in the case of toothpaste, dicalcium phosphate dihydrate and anhydride, calcium carbonate, calcium pyrophosphate, calcium sulfate, insoluble sodium metaphosphate, amorphous silica, crystalline silica, aluminosilicate, aluminum hydroxide. , aluminum oxide, resin, and other abrasives (compounding amount is usually 20 to 60
%), carboxymethyl cellulose, hydroxyethyl cellulose, alginate, carrageenan,
Binder (0.3-5%) such as gum arabic, polyvinyl alcohol, thickener (10-70%) such as polyethylene glycol, sorbitol, glycerin, propylene glycol, sodium lauryl sulfate, sodium dodecylbenzenesulfonate,
Hydrogenated Coconut Fatty Acid Monoglyceride Sodium Monosulfate, Sodium Lauryl Sulfoacetate,
Foaming agents (0-5
%), and sweeteners such as saccharin sodium, stevioside, neohesperidyl dihydrochalcone, glycyrrhizin, perillartine, p-methoxycinnamic aldehyde, thaumatin, etc.
- Mix ingredients such as menthol, carvone, eugenol, anethole, peppermint oil, spearmint oil and other fragrances and preservatives with water and produce according to a conventional method. The oral composition of the present invention also includes lysozyme chloride, dextranase, lytic enzyme, mutanase,
Chlorhexidine or its salts, sorbic acid, alexidine, hinokitiol, cetylpyridinium chloride, alkylglycine, alkyldiaminoethylglycine salt, allantoin, ε-aminocaproic acid, tranexamic acid, azulene, vitamin E, sodium monofluorophosphate, sodium fluoride, Active ingredients such as stannous fluoride, water-soluble primary or secondary phosphates, quaternary ammonium compounds, and sodium chloride may also be incorporated. The oral composition of the present invention is used by a conventional method depending on the type of composition, but brushing is difficult because the inorganic powder layer collapses after a predetermined time and the color of the pigment is revealed. The end point is clear, the brushing time is reliably controlled, and the oral cavity can be cleaned well. EXAMPLES The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the present invention is not limited to the Examples below. Examples 1 to 8, Comparative Examples 1 to 3 Surface coating pigments were produced by the following method, and were uniformly blended into toothpaste having the following formulation. Method for manufacturing surface coating pigment Polyvinyl alcohol (PVA) was dispersed in water and heated to 90°C to dissolve it. After this solution was cooled to room temperature, the dyes shown in Table 1 were added and thoroughly kneaded using a mortar. Next, this kneaded product is placed in a small pulverizer with a capacity of 75 ml and equipped with a cutter, and while it is pulverized, inorganic powder is added and mixed to form an inorganic powder coating layer on the surface of the kneaded product of the pigment and polyvinyl alcohol. After that, it is dried to a particle size of 10~
A surface coating dye of about 200μ was obtained. Table 1 shows the types and amounts of the pigments, PVA, and inorganic powders used, and the appearance (color) of the surface coating pigments.
The results of visual evaluation are shown. Toothpaste formulation Dicalcium phosphate 50.0% Sorbit 20.0 Sodium lauryl sulfate 2.0 Carboxymethyl cellulose 1.0 Satucharin 0.1 Flavor 1.0 Surface coating pigment 1.0 Purified water Remaining total 100.0% The surface coating pigment was slowly mixed into the toothpaste. Appearance (color) of toothpaste containing surface coating pigment
Table 1 also shows the results of visual evaluation. In this case, the appearance (color) of the toothpaste without the surface coating pigment is white.

【table】

[Table] **: The overall color appears pale due to uneven surface coverage.
Next, 1 to 2 g of the surface-coated toothpaste containing pigment was placed on a toothbrush, and the teeth were brushed for a predetermined period of time, and the degree of coloration at each time period was visually evaluated according to the following evaluation criteria. The results are shown in Table 2. Note that there were 5 people on the panel, and the results were shown as the average score of the 5 people.

【table】

[Table] Evaluation criteria 0 points: No coloration 1 point: Slight coloration 2 points: Coloration 3 points: Extremely coloration According to the results in Table 2, the toothpaste of the example was 2 to 2.5 points.
After a few minutes, the color changed and the end point of brushing could be clearly sensed, so that the brushing time could be controlled correctly. Examples 9 to 20, Comparative Examples 4 to 6 Surface coating pigments were produced using the ingredients shown in Table 3 by the following method, and uniformly applied to toothpastes with the same formulations as those shown in Examples 1 to 8. The degree of color development was evaluated when brushing was performed in the same manner as above. The results are shown in Table 4. Method for manufacturing surface coating pigments The pigments shown in Table 3 and a solution of a polymeric substance are thoroughly kneaded using a mortar, and then this kneaded product is mixed by volume.
Place in a 75ml small crusher with a cutter, add inorganic powder and mix while pulverizing this mixture to form a coating layer of inorganic powder, then dry to a particle size of 10.
A surface coating of pigment on the order of ~200μ was obtained. Table 3 shows the types and amounts of the dyes, polymeric substances, and inorganic powders used, as well as the results of visually evaluating the appearance (color) of the surface coating dyes.

【table】

[Table] *: The overall color appears pale due to uneven surface coverage.

【table】

[Table] The results in Table 4 also show that the oral composition according to the present invention clearly changes color after 2 to 2.5 minutes, indicating the end of brushing.

Claims (1)

[Claims] 1. A dye and one or two of the following polymeric substances (A) to (C).
An oral cavity characterized in that a surface coating pigment is blended in which the surface of particles consisting of seeds or more is coated with an inorganic powder, and the coating layer of the inorganic powder is broken down by brushing to reveal the pigment. Composition for use. (A) Gel-forming polyvinyl alcohol with a saponification degree of 85% or more and a polymerization degree of 500 or more. (B) Ethylcellulose, nitrocellulose, polyacrylic esters, polyvinyl acetate, polyvinyl chloride, and polyacrylonitrile, each having a solubility parameter value of 9.4 or higher. (C) A copolymer of a monomer selected from acrylic esters, vinyl acetate, vinyl chloride, and acrylonitrile and a monomer selected from olefins and styrene, each having a solubility parameter value of 9.5 or more.