GB2164560A - Lavatory cleansing - Google Patents

Abstract

A lavatory bowl is cleansed by adding to the water in the bowl an aqueous solution of (a) a hypochlorite bleach and (b) a dyestuff which is Acid Blue 7. A device for cleaning lavatories and adapted to be located in the cistern of a lavatory comprises a pair of dispensing compartments, one containing a hypochlorite bleach in solid form and the other containing a solid composition containing a dyestuff which is Acid Blue 7.

Description

SPECIFICATION Lavatory cleansing This invention is concerned with improvements in and relating to lavatory cleansing and to devices for use therein.

The use of hypochlorite bleaches to cleanse and sanitize lavatory bowls is well-established. One method by which a hypochlorite bleach may be introduced into the flush water of a lavatory is by means of a dispensing device which is placed in the water cistern of the lavatory and which is so arranged as to release a more or less metered dose of hypochlorite bleach solution into the cistern on flushing of the cistern.

It is also known to aid the cleaning of lavatory bowls by introducing into the flush water a surface active agent and this may be added by the use of a similar dispensing device to that used for dispensing hypochlorite bleach into the flush water or by means of a free-standing block of a slow dissolving composition comprising the surface active agent. In either case, it is common practice to include a dye, generally a blue dye, in the composition from which the surface active agent is released and, of recent years, presence of a colouration, particularly a blue colouration, in a lavatory bowl has come to indicate that the user of the lavatory takes care over the sanitation of the lavatory. The dye also serves the purpose of indicating that the particular cleaning system is in operation, i.e. has not been exhausted.

It is desirable to devise a system for cleaning lavatory bowls which releases both the dye and a hypochlorite bleach into the flush water. The problem is that hypochlorite bleaches, even in low concentrations, are powerful oxidising agents. As a result, if a dye and a hypochlorite bleach are together introduced into the flush water the bleach, will, in the vast majority of cases, rapidly oxidise the dyestuff to a colourless state, often via an unacceptably unpleasanatly coloured transient intermediate.

It has now been found, in accordance with the present invention, that a certain dyestuff, as hereinafter noted, have sufficient resistance to the action of hypochlorite bleaches, at least in the concentrations commonly encountered in the cleansing of lavatory bowls, to render it effective for use with hypochlorite bleaches in such cleansing in that it will gradually fade to a colourless state, under the action of bleach, but not via unacceptably unpleasant transient intermediates.

Accordingly, one embodiment of the invention provides a method of cleansing a lavatory bowl which comprises adding to the water in the bowl an aqueous solution of (a) a hypochlorite bleach and (b) a dyestuff which is Acid Blue 7.

As noted above, Acid Blue 7 is such that on contact with a hypochlorite bleach it generally fades in colour without passing through unpleasantly coloured intermediates. However, if the relative level of dye to bleach is sufficiently high this may not occur to an appreciable extent, i.e. the dye will retain its colour. Generally we prefer to employ such levels of dye that the dye does fade, thus indicating to the user the fact that the bleach is "working".

The bleach and dye are most conveniently added to the water by means of a dispensing device located in the cistern.

Accordingly, another embodiment of the invention provides a device for cleaning lavatories and adapted to be located in the cistern of a lavatory, which device comprises a pair of dispensing compartments, one containing a hypochlorite bleach in a solid form and the other containing a solid composition containing a dyestuff which is Acid Blue 7.

The term "dispensing compartment" as used herein is intended to refer to a compartment having ports or vents such that when the cistern in which the compartment is located is filled with water, after flushing, water enters the compartment so that some of the contents thereof (bleach or dyecontaining composition) are dissolved therein, and when water empties from the cistern, on flushing, some at least of the solution in the compartment is dispensed into the cistern. In its simplest form such a compartment comprises a closed compartment having two apertures, one, the lower, located at a position intermediate the top and bottom of the compartment and the other, the upper, located at or near the top of the compartment; the solid material being located in the compartment generally below the level of the lower aperture.Thus, in operation, on filling of the cistern, water flows into the compartment via the lower aperture, the upper aperture serving as a vent, and on emptying of the cistern water (containing dissolved solids) is dispensed into the cistern from the lower aperture.

A variety of devices of this type have been proposed and are described for example in British Patent Specifications Nos. 1,035,2101,193,063 and 1,219,200.

In a modification of the device generally described above, the water is siphoned from the dispensing compartment and in this connection reference may be made to United States Patent Specifications Nos.

1,175,032 and 4,028,747.

An essential feature of the present invention is the dyestuff employed. Acid Blue 7 (C.l. No. 42080) is commercially available from a variety of suppliers.

The composition containing the dyestuff, in the apparatus of the invention, will generally comprise a surface active agent optionally together with one or more of inertfillers and dissolution retardants. A wide variety of compositions, particularly those containing dissolution retardants have been proposed and are discussed at length in British Patent Specification No.2089830. Further, the dyestuff-containing composition may contain other ingredients such as perfumes.

The hypochlorite bleach may be any that supplies hypochlorite ion (-OCI') or hypochlorous acid (Hocl) in aqueous solution. Examples of such material include alkali metal and alkaline earth metal hypochlorites, such as sodium hypochlorite or calcium hypochlorite; chlorinated cyanuric acid derivatives, such as trichloroisocyanuric acid and sodium dichlorisocyanurate; and other N chlorinated organic compounds such as N-chlorosuccinimide.

Claims (6)

1. Amethod of cleansing a lavatory block which comprises adding to the water in the bowl an aqueous solution (a) a hypochlorite bleach and (b) a dyestuff which is Acid Blue 7.

2. A method as claimed in claim 1 in which the bleach and dye are added to the water by means of a dispensing device located in the system.

3. A device for cleaning lavatories and adapted to be located in the cistern of a lavatory, which device comprises a pair of dispensing compartments, one containing a hypochlorite bleach in solid form and the other containing a solid composition containing a dyestuff which is Acid Blue 7.

4. A device as claimed in claim 3 in which the composition containing the dyestuff also contains a surface active agent, optionally together with one or more of inert fillers, dissolution retardants and perfumes.

5. A method as claimed in claim 1 substantially as hereinbefore described.

6. A device as claimed in claim 3 substantially as hereinbefore described.