MOLD REMOVER PRODUCT

Abstract: A mold remover product is composed of (A) hydrogen peroxide or a peroxide that can generate hydrogen peroxide in an aqueous solution at the concentration of 0.5-60 wt.% as hydrogen peroxide generated and (B) an alkali metal salt of cyanic acid or amonium salt of cyanic acid at the concentration of 0.2-30 wt.% in an aqueous solution, characterized by a pH of 7-13. This invention offers a mold remover product with excellent bleaching activity on mold on the surfaces of household walls or furnishings, especially on kitchen sinks, bathrooms walls and ceilings and on tile joints without an irritating or offensive odor.

Description: DESCRIPTION Mold Remover Product Technical Field This invention is concerned with a mold remover product of peroxide type with excellent effects without an irritating odor and exhibiting excellent mold-removing and cleansing activities. The mold remover product of this invention is used to bleach mold that grows on the surfaces of household walls or furnishings. Background Art In bleaching mold that grows on household walls or furnishings, chlorine-type bleach has been used with the main component of sodium hypochlorite. However, the chlorine-type bleach is fraught with problems such as inducing unpleasant sensation to the user because of the specific odor of molecular chlorine generated and also the danger of poisoning the user by chlorine gas even if an excellent bleach activity is shown. Furthermore, there is a possibility of the production of organic chlorine compounds from the chlorine-type bleach. Therefore, there has been demand to develop bleach without using chlorine- type compounds from the viewpoint of prevention of environmental pollution. In order to remove stains from household walls or furnishings, particularly on the washbasin in the kitchen, on bathroom walls and on ceilings or tile joints [sic; grout], it is necessary to use a product with excellent activity of removing or bleaching mold, because stains at such places are composed of mold. However, mold exhibits strong resistance to bleaches that are generally used and it is extremely difficult to carry out complete bleaching on mold compared to the ease of bleaching fibers and others. Only weak bleaching activity is exerted on mold by bleaches of the peroxide type such as hydrogen peroxide, inorganic peroxides and organic peroxides. The complete bleaching of mold has been impossible by the use of such products. Various proposals have been made to improve the bleaching activity of peroxide-type bleach products. Japanese Patent Application Laid-open No. [Sho]-61-42600 described how peroxide- type bleaches can be used with activating agents such as glucose pentaacetate, tetraacetylethylenediamine, tetraacetylglycoluril and cyanamide. However, there are problems with the use of such activators in that the products were not sufficiently strong in bleaching mold and in that products with an irritating odor were produced by reaction with hydrogen peroxide. Japanese Patent Application Laid-open No. [Sho]-52-110287 described a bleach product composed of peroxide and cyanamide and/or a metal cyanamide to be used for bleaching fiber material, but the bleaching activity is not sufficient with mold. U.S. Patent No. 3,756,774 described a bleach product composed of peroxide and organic cyanide at pH 4-7 to be used for bleaching fiber material, but the bleaching activity is not sufficient with mold. Japanese Patent Application Laid-open No. [Sho]-62-1790 described a mold-removing product composed of peroxide and silicone oil and/or an emulsion thereof, but the bleaching activity is not sufficient with mold. Japanese Patent Application Laid-open No. [Sho]-62-149800 described the use of an alkali metal salt of cyanic acid as the activator of peroxide, but there is no description on the bleaching of mold. Disclosure of Invention This invention offers a mold-removing product with excellent bleaching activity on mold that grows on household walls or furnishings, especially mold on the washbasin in the kitchen, on the bathroom walls and ceilings and on tile joints without an irritating odor. Also, a method is offered for the bleaching of mold. After intensive studies, we discovered that a markedly enhanced bleaching activity was achieved on mold by the product containing a salt of cyanic acid and hydrogen peroxide at a specific pH without being accompanied by an irritating odor. The present invention is the result of this discovery. As component (A) of this invention, we use hydrogen peroxide or a peroxide that produces hydrogen peroxide in aqueous solution. In particular, an aqueous solution of hydrogen peroxide is preferably used. In the product of this invention, components (A) is used at 0.5-60 wt% in general, preferably at 0.5-30 wt%, most preferably at 0.5-10 wt%, or practically at 1-6 wt% in terms of hydrogen peroxide. As a peroxide to produce hydrogen peroxide in water, one can use a compound that is an adduct of hydrogen peroxide. As the compound that is an adduct of hydrogen peroxide, one can cite the sodium carbonate adduct of hydrogen peroxide at the molar ratio of 2:3 or sodium perborate hydrate or tetrahydrate. When a compound that is an adduct of hydrogen peroxide is used, the amount used must be such that the hydrogen peroxide produced therefrom is within the range of concentration cited above. As the alkali metal salt of cyanic acid or ammonium salt of cyanic acid as component (B), one can cite potassium cyanate, sodium cyanate and ammonium cyanate, and one can use one or more such compounds. The content of component (B) in the product of this invention is 0.2-30 wt%, preferably 0.5-10 wt%, or most preferably 0.5-5 wt%. A commercially available salt of cyanic acid in solid form can be used. The content of peroxide as component (A) in the mold remover product of this invention is 0.5-60 wt% in general, preferably 0.5-30 wt%, or more preferably 0.5-10 wt%, or most preferably in practice 1-6 wt%. The content of the salt of cyanic acid as component (B) is 0.2-30 wt%, preferably 0.5-10 wt%, or most preferably 0.5-5 wt%. If the content of component (A) or (B) is less than these ranges, the bleaching activity becomes too low. If the content of component (A) or (B) is more than these ranges, the handling becomes difficult as the product for mold remover. The pH is important in the mold remover product of this invention to achieve excellent bleaching activity. The pH is usually 7-13, or preferably 8-13, or most preferably 9.0-12.4. If pH of the product is less than this range, the bleaching activity becomes weak. If it is more than this range, the peroxide compound becomes unstable, so that it is difficult to handle as a mold-removing product. It is preferable to use alkali metal hydroxide or alkali metal silicate salt in order to adjust pH of the mold remover product of this invention within the aforementioned range. As the alkali metal hydroxide or alkali metal silicate salt, one can use the hydroxide of an alkali metal, such as lithium hydroxide, sodium hydroxide and potassium hydroxide, and the silicate salt of an alkali metal, such as sodium silicate and potassium silicate. It is preferable to use an alkali metal silicate salt such as sodium silicate or potassium silicate, as the bleaching activity is markedly improved. The content of alkali metal hydroxide or alkali metal silicate salt is in the range of 0.01-10 wt%, so that the pH of the mold remover product lies within the aforementioned range. If the sodium carbonate adduct of hydrogen peroxide or sodium perborate is used as the source of hydrogen peroxide, the aqueous solution of these compounds are alkaline by themselves, so that the amount of the alkali metal hydroxide or alkali metal silicate salt used can be reduced. The mold remover product of this invention is prepared by dissolving (A) hydrogen peroxide or a compound that is an adduct of hydrogen peroxide and (B) an alkali metal salt of cyanic acid or ammonium salt of cyanic acid in water. The mold remover product of this invention can be a homogeneous aqueous solution or a slurry. The water content in the mold remover product of this invention is 40-99 wt%, preferably 50-98 wt%, or most preferably 60-97 wt% with respect to the whole product. It is preferable to add surfactant as well to the mold remover product of this invention. As such a surfactant, one can cite polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters and amine oxides as nonionic surfactants, or soaps, alkyl sulfate salts and alkylbenzenesulfonate salts as anionic surfactants. It is preferable to add the surfactant at 0.1-5 wt% in the mold remover product. By the addition of surfactant, permeation of the mold remover product into the mold is accelerated, resulting in enhanced effectiveness in the bleaching, washing and removal of mold. The mold remover product of this invention is used as a solution or as a slurry to be applied by spraying or by coating on the surface of household walls or furnishings that have mold. By this method, it is possible to bleach mold effectively. Description of Preferred Embodiments The invention is explained with application examples, but the invention is not limited by these examples. Application Example 1 An aqueous solution of hydrogen peroxide, potassium cyanate and an aqueous solution of sodium etasilicate were added to water and mixed to attain the concentration of hydrogen peroxide at 3.0 wt%, of potassium cyanate at 5.0 wt% and of sodium metasilicate at 0.1 wt% to prepare a mold remover product. Its pH was 9.0. Using the mold remover product thus obtained, the test for mold bleaching and the odor evaluation were performed as follows. The results are shown in Table I. (Test method and evaluation of bleaching of mold) 1) Mold culture method An autoclaved agar culture medium was poured into a sterile petri dish to be inoculated with black mold (Aureobasidiu pullulans) . and the dish was incubated in an incubator at 350' C for 10 days. 2) Test method of mold bleaching A glass tube was placed over the agar plate on which mold had grown and the test solution was placed in the glass tube. Thirty minutes later, the degree of bleaching of the black mold was determined. 3) Evaluation method The degree of bleaching effect was classified in 3 stages described below by macroscopic observation. Degree of bleach [sic; III]: Completely bleached Degree of bleach [sic; II]: Bleached to some degree Degree of bleach [sic; I]: Almost or completed unbleached (Test method and evaluation of odor) 1 ) Test method of odor Ten panel members were asked to sniff the bleach product for sensory evaluation. 2) Evaluation of odor Odor was classified as follows: o: No irritating odor or offensive odor was sensed by almost all or all panel members. Δ: About a half of the panel members sensed irritating odor or offensive odor. X: Almost all or all panel members sensed irritating odor or offensive odor. Application Examples 2-10 Mold remover products were prepared with altered components and contents as shown in Table I, where the term % indicated wt%. The pH of solution is shown in Table I. As above, the mold bleaching test and the evaluation of odor were done with the results listed in Table I. Application Examples 11-12 Mold remover products were prepared by using hydrogen peroxide adducts of sodium carbonate and sodium perborate hydrate instead of hydrogen peroxide. The content of the hydrogen peroxide adduct of sodium carbonate or sodium perborate hydrate was expressed in terms of the hydrogen peroxide contained in these substances. Table II shows the results of the mold bleaching test and the evaluation of odor using these products. Comparative Example 1 A bleach product was prepared using sodium hypochlorite as shown in Table III. In the table, the term % indicates wt%. Table III shows the results of the mold bleaching test and the evaluation of odor carried out with the bleach products obtained. The pH of the products is also shown. The bleaching activity was excellent, but offensive odor of chlorine was marked. Comparative Example 2 Bleach products were prepared as in Application Example 2, except for omitting a salt of cyanic acid. Table III shows the results; the bleaching activity was reduced. Comparative Example 3 Bleach products were prepared as in Application Example 2, except for using tetraacetylethylenediamine instead of a salt of cyanic acid. Table III shows the results. The bleaching activity was somewhat reduced, and the strong odor of organic acid was perceived. Comparative Example 4 Bleach products were prepared as in Application Example 4, except for using sodium hydroxide at 10%. Table III shows the results. The pH of solution was 13.7, and the bleaching activity was reduced. Comparative Example 5 Bleach products were prepared similar to Application Example 10, except for omitting the use of a salt of cyanic acid. Table III shows the results. The bleaching activity was reduced. Table ] Appln. Example 1 2 3 4 5 6 7 8 9 10 Hydrgn. perox. 3% 3% 3% 3% 3% 3% 3% 3% 1% 20% Potass. cyanate 5% 5% 5% 5% 5% 5% 1% 5% 10% Sodium cyanate 5% Sodium metasil. 0.1% 2.5% 0.5% 0.5% 3% Sodium orthosil, 0.5% 0.1% 0.1% 0.1% Sodium hydrox. 0.5% 0.5% 0.5% 0.5% oH 9.2 11.0 9.6 9.7 10.5 10.1 9.7 10.0 10.9 9-2 Mold bleach III III III III III III III III III III Odor 0 0 0 0 0 0 0 0 0 0 Table II Application Example 11 12 SPC* 3% PB** 2% Potassium cyanate 5% 5% Sodium orthosilicate 0.1% 0.1% pH 9.8 10.1 Mold bleaching test III III Evaluation of odor o 0 SPC*: Hydrogen peroxide sodium carbonate adduct (concentration expressed as the concentration of hydrogen peroxide) PB**: Sodium perborate (concentration expressed as the concentration of hydrogen peroxide) Table III Comparative Example 1 2_ Hydrogen peroxide 3% 3% 3% SPC* 3% Sodium hypochlorite 3.5% Potassium cyanate 5% TAED*** 3% Sodium metasilicate 2.5% 2.5% Sodium hydroxide 10% pϋ 13.1 11.0 10.8 13.7 9.6 Mold bleaching test Evaluation of odor Q X. Q 0_ SPC*: Hydrogen peroxide sodium carbonate adduct (concentration expressed as the concentration of hydrogen peroxide) . TAED***: Tetraacetylethylenediamine This invention offers a mold remover product with an excellent bleaching activity on mold on the surface of household walls or furnishings, especially on kitchen sinks, bathroom walls and ceilings and on tile joints without an irritating or offensive odor.

Claims: CLAIMS 1. Mold remover product, characterized as an aqueous solution containing (A) hydrogen peroxide or peroxide compounds which generate hydrogen peroxide in aqueous solution at the concentration of 0.5-60 wt% as hydrogen peroxide and (B) an alkali metal salt of cyanic acid or ammonium salt of cyanic acid at the concentration of 0.2-30 wt% with the pH of the aqueous solution being 7-13.

Inventors: HIRO YASUO, KOBAYASHI TSUNEO, KOKUBU JUN, KURIYAMA YASUHISA, MIKAMI MASAHITO, NAKAMURA SHUZO, TSUJI YOSHIKO, HIRO, YASUO, KOBAYASHI, TSUNEO, KOKUBU, JUN, KURIYAMA, YASUHISA, MIKAMI, MASAHITO, NAKAMURA, SHUZO, TSUJI, YOSHIKO
Applicants: HIRO YASUO, JOHNSON CO LTD, KOBAYASHI TSUNEO, KOKUBU JUN, KURIYAMA YASUHISA, MIKAMI MASAHITO, NAKAMURA SHUZO, TSUJI YOSHIKO, HIRO, YASUO, JOHNSON CO., LTD., KOBAYASHI, TSUNEO, KOKUBU, JUN, KURIYAMA, YASUHISA, MIKAMI, MASAHITO, NAKAMURA, SHUZO, TSUJI, YOSHIKO
Application year: 1996
Main classification: C11D3
IPC codes: C11D3, C11D7