Denture cleanser composition

Abstract

To provide a denture washing composition that protects dentures from staining.SOLUTION: A denture washing composition contains, as a cationic surfactant, a compound having a nitrogen atom bonded with one C6-18 carbon chain.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to denture cleanser compositions. More particularly, the present invention relates to liquid cleanser compositions, especially concentrated liquid cleanser compositions. [Background technology]

[0002] In recent years, concentrated liquid denture cleansers that eliminate the need for dissolving in water have been proposed as denture cleansers that can be used in a short time. However, the types of dirt that adhere to dentures include denture plaque, food residue, stains (colored deposits), and tartar, and these must be cleaned and removed effectively in a short time. In particular, the adhesion of stains to dentures is undesirable from both a hygienic and aesthetic standpoint, and stain removal is a major challenge for denture cleansers.

[0003] For this reason, various liquid denture cleansers have been proposed that are effective in disinfecting Candida and removing stains. For example, a concentrated liquid denture cleanser composition containing a combination of (A) hydroxyethanediphosphonic acid, (B) an alkylamine oxide, and (C) benzoic acid or a derivative thereof (see Patent Document 1), and a liquid denture cleanser composition containing (A) hydroxyethanediphosphonic acid and (B) one or more surfactants selected from anionic surfactants and amphoteric surfactants, and having a pH of 5 to 9 at 20°C (see Patent Document 2) have been proposed. These compositions are said to be able to effectively remove stains without containing peroxides or bleaching agents. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-90501 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-90499 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a denture cleanser composition that has a disinfecting effect against Candida and also inhibits stain adhesion (coloring) to dentures. [Means for solving the problem]

[0006] In the course of conducting research to achieve the above-mentioned object, the inventors discovered that dentures cleaned with a denture cleanser containing a cationic surfactant that exhibits excellent antibacterial effects against Candida bacteria are prone to stain adhesion with use, which accumulates and makes them prone to discoloration. Through extensive research aimed at solving this problem, the inventors discovered that the use of a cationic surfactant, a compound in which a nitrogen atom is bonded to a linear carbon chain having 6 to 18 carbon atoms, particularly a quaternary ammonium salt, significantly inhibits stain adhesion to dentures and prevents discoloration of the dentures.

[0007] The present invention was completed after further investigation based on the discovery of the problems caused by the cationic surfactants and the means for solving them, and includes the following embodiments.

[0008] (I) Denture cleanser composition (I-1) A denture cleanser composition containing, as a cationic surfactant, a compound in which a group having an open carbon chain with 6 to 18 carbon atoms is bonded to one nitrogen atom. (I-2) A denture cleanser composition according to (I-1), wherein the compound is a quaternary ammonium salt. (I-3) A denture cleanser composition according to (I-1) or (I-2), which is a liquid composition, preferably a concentrated liquid composition.

[0009] (II) Method of using cationic surfactants (II-1) A method for using the cationic surfactant, characterized in that a compound having a group having an open carbon chain of 6 to 18 carbon atoms bonded to a nitrogen atom is blended into a denture cleanser composition, thereby imparting to the denture cleanser composition a disinfecting function and a function to inhibit stain adhesion to dentures. (II-2) The method of use according to (II-1), wherein the compound is a quaternary ammonium salt. (II-3) The method of use according to (II-1) or (II-2), wherein the denture cleanser composition is a liquid composition, preferably a concentrated liquid composition. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a liquid denture cleanser composition that has a disinfecting effect on dentures and also inhibits stain deposition. Specifically, the denture cleanser composition of the present invention exhibits an excellent disinfecting effect against Candida due to the disinfecting action of the cationic surfactant, while at the same time inhibiting stain deposition on dentures caused by the cationic surfactant. Therefore, according to the present invention, discoloration of dentures due to stain deposition when using a liquid denture cleanser, which is a problem with liquid denture cleanser compositions containing a cationic surfactant, can be effectively prevented. Furthermore, because the denture cleanser composition of the present invention can be provided in liquid form, it does not require the effort of dissolving a solid agent such as a tablet or granule, and can be used immediately to clean dentures either as is or after a simple procedure such as dilution. DETAILED DESCRIPTION OF THE INVENTION

[0011] (I) Denture cleanser composition The denture cleanser composition of the present invention is characterized by containing, as a cationic surfactant, a compound in which a group having an open carbon chain with 6 to 18 carbon atoms is bonded to a nitrogen atom (hereinafter, this will be referred to as "the compound").

[0012] The open carbon chain having 6 to 18 carbon atoms (hereinafter simply referred to as "C6-18 open carbon chain") in the present compound specifically includes an open hydrocarbon group (acyclic hydrocarbon group). The open hydrocarbon group includes an open saturated hydrocarbon group (alkyl group) and an open unsaturated hydrocarbon group (alkenyl group, alkynyl group). A open saturated hydrocarbon group is preferred. The open saturated hydrocarbon group may be a linear alkyl group or a branched alkyl group, but is preferably a linear alkyl group.

[0013] The number of carbon atoms in the linear carbon chain can be selected from the above-mentioned range of 6 to 18, and although not limited, it is preferably 8 to 18 carbon atoms, more preferably 12 to 18 carbon atoms. Specific examples include capryl group (octyl group), lauryl group (dodecyl group), myristyl group (tetradecyl group), cetyl group (hexadecyl group), and stearyl group (octadecyl group). Lauryl group, cetyl group, and stearyl group are preferred, and lauryl group is more preferred.

[0014] The group having a C6-18 open carbon chain may be the C6-18 open hydrocarbon group itself, or may be a group having the C6-18 open hydrocarbon group as a portion thereof. The group having a C6-18 open hydrocarbon group as a portion thereof is not limited, but includes groups in which a C6-18 open hydrocarbon group is bonded to an atom other than a carbon atom, such as an oxygen atom (e.g., alkoxy groups), and alkyl groups having such alkoxy groups (alkoxyalkyl groups). Specific examples include alkoxyalkyl groups in which an alkyl group having 1 to 6 carbon atoms, preferably 2 to 3 carbon atoms, is bonded to an alkoxy group having 6 to 18 carbon atoms.

[0015] The present compound is a compound in which one group having a C6-18 linear carbon chain is bonded to a nitrogen atom, and is preferably a quaternary ammonium compound. The other group bonded to the nitrogen atom is desirably an atom or group other than the group having a C6-18 linear carbon chain, or an acyclic group, such as a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms. Preferred is an alkyl group such as a methyl group or an ethyl group, and more preferably a methyl group. The present compound is preferably a trimethyl-type quaternary ammonium compound in which a nitrogen atom is bonded to a group having a C6-18 linear carbon chain and three methyl groups. Specific examples include lauryltrimethylammonium (dodecyltrimethylammonium), cetyltrimethylammonium (hexadecyltrimethylammonium), stearyltrimethylammonium (octadecyltrimethylammonium), coconut alkyltrimethylammonium, tallow alkyltrimethylammonium, octadecyloxypropyltrimethylammonium, and salts thereof. Lauryltrimethylammonium and its salts are preferred. Examples of salts include, but are not limited to, chlorides.

[0016] As shown in the experimental examples described below, these cationic surfactants have the advantage of not only exhibiting an effective antibacterial effect against Candida but also being less likely to induce stain deposition on denture materials. In contrast, dialkyl (C6-20) dimethyl ammonium salts and alkyl (C6-20) dimethyl benzyl ammonium salts, which are also quaternary ammonium compounds, also exhibit an effective antibacterial effect against Candida, but have the disadvantage of being more likely to induce stain deposition on denture materials. For this reason, it is preferable that the denture cleanser composition of the present invention contains only the present compounds as the cationic surfactant, either alone or in combination of two or more types, and does not contain any other cationic surfactants (for example, the above-mentioned quaternary ammonium compounds).

[0017] The amount of cationic surfactant (the present compound) in the denture cleanser composition of the present invention may be any amount that imparts a disinfecting effect to the denture cleanser composition. When the denture cleanser composition of the present invention is a liquid denture cleanser composition that is used without dilution (this may be referred to as a "concentrated liquid denture cleanser composition"), the proportion of the present compound can be appropriately selected from the range of 0.1 to 50% by mass of the total denture cleanser composition. It is preferably 0.5 to 30% by mass, and more preferably 1 to 20% by mass. When the denture cleanser composition of the present invention is a liquid denture cleanser composition that is used by diluting it with tap water (this may be referred to as a "concentrated liquid denture cleanser composition"), for example, when the dilution rate is 10 times, the proportion of the present compound can be appropriately selected from the range of 0.01 to 5% by mass of the total denture cleanser composition. It is preferably 0.05 to 3% by mass, and more preferably 0.1 to 2% by mass.

[0018] In addition to the above components, the denture cleanser composition of the present invention may contain other known components as needed, such as, but not limited to, surfactants (anionic surfactants, amphoteric surfactants, nonionic surfactants), solvents, fragrances, colorants, buffers, pH adjusters, disinfectants, stabilizers, and rust inhibitors.

[0019] Examples of anionic surfactants include, but are not limited to, alkyl sulfates, α-olefin sulfonates, acylamino acid salts, and alkyl phosphates. Among them, from the viewpoint of stain removal power, alkyl sulfates having 8 to 18 carbon atoms (e.g., lauryl sulfate), α-olefin sulfonates having 8 to 18 carbon atoms, and acylamino acid salts having an acyl group with 8 to 18 carbon atoms are preferred, and the above-mentioned acylamino acid salts are more preferred. As the salt, alkali metal salts such as sodium salts and potassium salts are preferred, and sodium salts are particularly preferred.

[0020] Examples of amphoteric surfactants include alkylamine oxides and betaine-type amphoteric surfactants. As the alkylamine oxide, alkyldimethylamine oxides can be used, preferably those in which the alkyl group has 12 to 18 carbon atoms, particularly 12 to 16 carbon atoms, such as lauryldimethylamine oxide.

[0021] Examples of betaine-type amphoteric surfactants include 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, fatty acid amidopropyl betaines such as coconut oil fatty acid amidopropyl betaine, and lauryl dimethylaminoacetic acid betaine. Of these, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine and fatty acid amidopropyl betaine are preferred, with fatty acid amidopropyl betaine being particularly preferred.

[0022] As the nonionic surfactant, polyethylene glycol type surfactants, particularly polyoxyethylene alkyl ether and polyoxyethylene hydrogenated castor oil, are preferred, and more preferred are polyoxyethylene alkyl ethers having an alkyl group with 12 to 20 carbon atoms and an average added mole number of ethylene oxide (hereinafter abbreviated as EO added mole number) of 10 to 20 moles and / or polyoxyethylene hydrogenated castor oil having an EO added mole number of 5 to 60 moles.

[0023] These surfactants can be used alone or in any combination of two or more. The amount of these surfactants (anionic surfactants, amphoteric surfactants, nonionic surfactants) in the denture cleanser composition of the present invention is not limited, but can be appropriately selected from the range of 0.1 to 50% by mass of the total amount in the case of a concentrate-type liquid denture cleanser composition, for example. It is preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass.

[0024] As the solvent, water (ion-exchanged water) is usually used, but lower alcohols such as ethanol and polyhydric alcohols such as glycerin can also be added in an amount of, for example, about 1 to 30% by mass.

[0025] Since the cationic surfactants described above exert a disinfecting effect, it is not necessary to incorporate a disinfectant, but a nonionic disinfectant such as isopropylmethylphenol can also be incorporated. In the present invention, oxidizing agents and bleaching agents such as peroxides (e.g., sodium percarbonate and sodium perborate), hypochlorous acid or its salts, and sulfites, which are used as denture cleanser components, are poorly stable, particularly in liquid compositions, and therefore should not be incorporated (0% inclusion amount). Even if they are incorporated, it is preferable to limit the amount incorporated to a small amount, such as 0.03% or less, and especially 0.01% or less, of the total undiluted denture cleanser composition.

[0026] The denture cleanser composition of the present invention is preferably adjusted so that the pH at 20°C upon use (when diluted with tap water) is 5 to 9. The preferred pH is 5.3 to 8. The pH may be adjusted spontaneously, or may be adjusted by adding a pH adjuster as appropriate.

[0027] The denture cleanser composition of the present invention is prepared in liquid form using the solvent described above. This liquid denture cleanser composition may be one that can be used as is without dilution at the time of use (undiluted liquid denture cleanser composition), but if necessary, dentures may be immersed in a diluted solution prepared by diluting a concentrated liquid denture cleanser composition with water. After immersion and cleaning, the dentures can be used by rinsing with water as necessary. When preparing a concentrated liquid denture cleanser composition, it is preferable to design the concentration of the formulation so that when the composition is diluted with water 10 to 100 times, particularly 10 to 50 times, from the standpoints of usability and solubility, the concentration of the cationic surfactant falls within the range of concentrations in the undiluted liquid denture cleanser composition.

[0028] The denture immersion time is preferably 5 minutes or more, more preferably 10 minutes or more. There is no particular upper limit to the immersion time, but it is usually 8 hours or less, and particularly 6 hours or less. It is even more effective to immerse the denture in the liquid denture cleanser composition of the present invention after lightly removing stains with a toothbrush or the like. Furthermore, since the liquid denture cleanser composition of the present invention is liquid and highly dispersible, it may be diluted with a detergent solution and cleaned in combination with a known ultrasonic cleaner. In this case, the denture immersion time is preferably 15 minutes or less, and particularly about 5 minutes. Using a toothbrush or ultrasonic cleaner, denture stains can be removed more efficiently.

[0029] (II) Method of using cationic surfactants The present invention provides a method for using a denture cleanser composition, characterized in that the denture cleanser composition is imparted with a disinfecting function and a function to inhibit stain adhesion to dentures by incorporating a compound comprising a nitrogen atom and an open carbon chain having 6 to 18 carbon atoms as a cationic surfactant into the denture cleanser composition. The type of the present compound used as the cationic surfactant and its ratio relative to the denture cleanser composition are as explained in (I) above, and the description therein can be incorporated by reference in this section. As described above, in this specification, the terms "comprise" and "contain" encompass the meanings of "consist of" and "consist essentially of." [Example]

[0030] The present invention will be explained below using experimental examples to aid in understanding the configuration and effects of the present invention. However, the present invention is not limited by these experimental examples. Unless otherwise specified, the following experiments were carried out at room temperature (25±5°C) and atmospheric pressure. Unless otherwise specified, "%" and "parts" in the following descriptions mean "% by mass" and "parts by mass," respectively.

[0031] Experimental Example 1: Evaluation of the disinfecting effect of aqueous solutions containing cationic surfactants and stain adhesion to dentures (Part 1) Concentrated liquid denture cleanser compositions (Examples 1 to 3, Comparative Examples 1 to 4) were prepared by dissolving various cationic surfactants listed in Table 1 in purified water. Using these, the following tests (disinfection test, stain adhesion [coloring] test) were carried out to evaluate the disinfecting effect and stain adhesion.

[0032] (1) Experimental method (1-1) Stain adhesion test The following operations were carried out: 1) Each concentrated liquid denture cleanser composition (Examples 1 to 3, Comparative Examples 1 to 4) was diluted 15-fold with tap water to prepare 2 mL of cleaning solution, which was then placed in a 6-well plate. Additionally, as a reference example, purified water was similarly diluted 15-fold with tap water to prepare 2 mL of cleaning solution, which was then placed in a 6-well plate. 2) Resin (manufactured by Wada Precision Dental Research Co., Ltd.) (size: 20mm x 20mm x 1.5mm square) that has been immersed in artificial saliva for 5 seconds is placed in 2mL of the above cleaning solution and immersed. 3) Leave to stand at room temperature for 30 minutes. 4) After leaving it to stand, remove the resin from the cleaning solution and remove any cleaning solution adhering to the surface with a Kimtowel (manufactured by Nippon Paper Crecia Co., Ltd.). 5) Immerse the resin in an artificial stain solution (add two tea bags to 600 mL of distilled water, boil for 10 minutes, add instant coffee, stir to dissolve, and then cool to room temperature) and leave to stand for 30 minutes. 6) After leaving it to stand, remove the resin from the stain solution and dry it in a constant temperature bath at 50°C. 7) The above steps 1) to 6) were repeated three times, and the degree of coloration of the resin was visually observed.

[0033] (1-2) Sterilization test Using Candida albicans (NBRC1595) (purchased from the National Institute of Technology and Evaluation), an evaluation test of the antibacterial effect was conducted according to the following procedure. Candida is known to adhere to dentures and cause odor and stains.

[0034] (1) Cultivation of Candida albicans NBRC1595 strain The strain was cultured overnight at 35°C on potato dextrose agar medium (Kohjin Bio) and suspended in a medium (5% sucrose TSB medium) containing 5% sucrose (Trypticase Soy Broth, BD). The suspension was then diluted appropriately using a spectrophotometer to a turbidity of 0.150 at 600 nm (OD600). Next, a 3 x 3 cm PMMA resin plate treated with 100 μg / mL albumin was placed in each well of a 6-well plate. Five mL of the diluted bacterial solution was added, and the plate was incubated at 35°C for 18 hours to form a biofilm on the resin plate.

[0035] (2) Sterilization test After incubation, the resin plate was slowly removed from the well and then immersed in each concentrated liquid denture cleanser composition (Examples 1 to 3, Comparative Examples 1 to 4) diluted 30 times with purified water for 5 minutes (n=6 for each composition).The resin plate was then slowly removed and washed with sterilized purified water. Next, the washed resin plate was placed in SCDLP liquid medium (Soybean-Casein Digest Broth with Lecithin & Polysorbate 8, manufactured by Daigo Co., Ltd.), and the biofilm was removed from the resin plate using a cell lifter (manufactured by Bioramo Co., Ltd.) and suspended. A 10-fold dilution series was prepared using the resulting suspension, and 100 μL each of the 10-fold, 100-fold, and 1000-fold diluted solutions was smeared on GPLP agar medium (Glucose Peptone Agar with Lecithin & Polysorbate 80, manufactured by Daigo Co., Ltd.). After culturing at 35 ° C. for 24 hours, the number of grown colonies (number of colonies per 1 mL of the suspension) was counted. This was designated as the "number of colonies after washing" in the following formula.

[0036] The sterilization rate was calculated using the following formula: Specifically, first, the sterilization rate A for each resin plate was calculated, and the average value of the sterilization rates A for a total of six resin plates was taken as the sterilization rate (%) of the sterilization test. [formula] Elimination rate A (%) = {1-(number of colonies after washing / number of colonies before washing)} x 100

[0037] In this formula, the "unwashed colony count" refers to the number of colonies counted in the same manner as the number of colonies after washing, except for the step of immersing the specimens for 5 minutes in each concentrated liquid denture cleanser composition diluted 30 times with purified water in (2) above.

[0038] (2) Experimental results The experimental results are summarized in Table 1. The test results were evaluated according to the following criteria.

[0039] (2-1) Stain adhesion (coloring) ○: The degree of coloring is almost the same as that of the resin treated with the cleaning solution of the reference example (reference resin). ×: The degree of coloring is clearly darker than the degree of coloring of the reference resin.

[0040] (2-2) Disinfection effect The sterilization rate calculated by the above method was evaluated according to the following criteria, where a higher value indicates a higher sterilization rate. ○: Elimination rate is 99% or more ×: Sterilization rate is less than 99% [Table 1]

[0041] As shown in Table 1, it was confirmed that an effective disinfecting effect can be obtained by adding a cationic surfactant to a denture cleanser, and that depending on the type of cationic surfactant used, stains can accumulate on the denture material (Comparative Examples 1 to 4). .mosquito Thione surfactants include lauryl chloride Bird It has been confirmed that by using a compound such as methylammonium, in which a nitrogen atom is bonded to a linear carbon chain with 6 to 18 carbon atoms, an effective disinfecting effect can be obtained, and the accumulation of stains on denture materials can also be suppressed or prevented. A similar trend was also observed in compounds in which a single open carbon chain with 6 to 18 carbon atoms is bonded to a nitrogen atom, such as cetyltrimethylammonium chloride and stearyltrimethylammonium chloride.

[0042] Experimental Example 2: Evaluation of the disinfecting effect of aqueous solutions containing cationic surfactants and stain adhesion to dentures (Part 2) Concentrated liquid denture cleanser compositions (Examples 4 and 5, Comparative Examples 5 and 6) were prepared by dissolving various cationic surfactants and other ingredients listed in Table 2 in purified water. Using these, a sterilization test and a stain adhesion (coloring) test were carried out in the same manner as in Experimental Example 1, and the sterilization effect and stain adhesion were evaluated.

[0043] The results are also shown in Table 2. [Table 2]

[0044] As shown in Table 2, lauryl chloride was used as a cationic surfactant. Bird It has been confirmed that the use of compounds in which one linear carbon chain with 6 to 18 carbon atoms is bonded to a nitrogen atom, such as methylammonium, particularly quaternary ammonium salts, provides an effective disinfecting effect and also inhibits or prevents the accumulation of stains on denture materials.On the other hand, cationic surfactants such as didecyldimethylammonium sulfate, in which two linear carbon chains with 6 to 18 carbon atoms are bonded to a nitrogen atom, and quaternary ammonium salts with a cyclic carbon chain with 6 to 18 carbon atoms, such as benzalkonium chloride, provide effective disinfecting effects, but cause stains to accumulate on denture materials and discoloration with use.

[0045] Concentrated liquid denture cleanser compositions of the present invention were prepared according to the formulations shown in the table below. These can be diluted 10 to 50 times with tap water before use and used for immersion cleaning of dentures. [Table 3]

Claims

1. A liquid denture cleanser composition containing 0.1 to 50% by mass of at least one cationic surfactant selected from the group consisting of lauryltrimethylammonium, cetyltrimethylammonium, stearyltrimethylammonium, and salts thereof: However, the following compositions (1) and (2) are excluded: (1) General formula (1) (wherein R 1 is an alkyl group having 6 or more carbon atoms, R 2 and R 3 may be the same or different, each being an alkyl group having 1 to 6 carbon atoms, R 4 is an alkylene group having 1 to 6 carbon atoms, R 5 , R 6 and R 7 may be the same or different, each being an alkyl group or alkoxy group having 1 to 6 carbon atoms, and X is a halogen ion or an organic carbonyloxy ion), and Cationic surfactants (excluding the above silicon-containing compounds) A cleaning composition comprising (2) (A) Citral 0.002% by mass or more and 0.1% by mass or less (B) Cationic disinfectant: 0.001% by mass or more and 0.1% by mass or less (C) Fragrance components other than component (A): 0.35% by mass or less Contains An oral composition containing no ethanol or containing 12% by mass or less of ethanol and 0.2% by mass or more and 1.5% by mass or less of polyoxyethylene hydrogenated castor oil, The oral composition, wherein the cationic antiseptic is at least one selected from the group consisting of lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, and stearyltrimethylammonium chloride.

2. 2. The denture cleanser composition according to claim 1, which has a pH of 5 to 9 at 20° C. when diluted with tap water.

3. does not contain dialkyl (C6-C20) dimethyl ammonium salts and alkyl (C6-C20) dimethyl benzyl ammonium salts, and / or the content of at least one compound selected from the group consisting of sodium percarbonate, sodium perborate, hypochlorous acid or a salt thereof, and a sulfite is 0 to 0.03% by mass; 3. A denture cleanser composition according to claim 1 or 2.

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