HUP0200401A2 - Lavatory cleansing block - Google Patents

Description

The invention relates to toilet cleaning blocks which can be used for cleaning and/or purifying the flush water of a toilet or urinal.

It is known to use toilet cleaning blocks to introduce cleaning and/or other components into the flush water of a toilet or urinal. Such compositions may, among other things, be immersed in the flush water of the toilet or may be held under the rim of the toilet in a suitable holder for periodic contact of the solid material with the flush water. For the sake of simplicity, these solutions are referred to in the description as a water tank block and a rim block.

In recent years, the use of halogen releasing agents or other bleaching agents in toilet cleaning blocks has become common. It is known from EP 0 206 725 that halogen releasing agents are by their nature reactive chemical reagents, serving as halogenating or oxidizing agents, and consequently the incorporation of bleach-sensitive components, such as fragrances and dyes, into blocks containing bleaching agents is complicated.

A toilet cleaning block has been disclosed in which two incompatible components are separated by placing them in different phases of the toilet cleaning block (EP 0 101 402).

We have found that in the case of a dual-phase toilet cleaning block, where one phase tends to dissolve faster than the other phase, this leads to an uneven dosage of ingredients in the final flush water of the toilet.

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We have found that an improved toilet cleaning block can be formulated in which the difficulty caused by uneven dissolution between the phases of a multiphase block can be reduced.

Based on the above, the invention is a toilet cleaning block comprising at least 2 phases, wherein a 1st phase comprises a water-insoluble salt as at least 50% by weight of the salt present therein, and a 2nd phase comprises a fragrance and a water-soluble salt, wherein the anion of the salts in the two phases is the same.

The toilet cleaning block of the invention is produced by coextruding the two phases that make up the block.

In order to provide a more complete understanding of the invention, preferred and alternative features of the invention are described below.

Many

The invention preferably relates to a dual-phase cleaning block.

Phase 1 of the block comprises at least 50% by weight of the salt present therein as a water-insoluble salt. In the context of the invention, the term water-insoluble salt denotes salts having a solubility of not more than 0.05 g per ¹⁰⁰ cm3 of water at 25°C.

Phase 2 of the block contains a fragrance and a water-soluble salt. The term water-soluble salt refers to salts having a solubility of at least 0.5 g, preferably >1 g, per 100 cm3 of water ^{at 0} °C. The salts should contain the same anions in both phases.

Other salts containing different anions may be present in each phase. However, it is highly advantageous if phase 1

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PCT/EP00/01184 • · ····· · ·· · · ♦ · ·· does not contain a water-soluble salt whose anion is the same as that of the water-insoluble salt.

The total amount of water-soluble salt containing the same anion as the water-insoluble salt in phase 2 is 1-10% by weight of all components present in phase 2.

Phase 2 preferably further comprises a water-insoluble salt having an anion identical to that of the water-soluble salt. The weight ratio of the water-soluble salt to the water-insoluble salt having the same anion in phase 2 of the toilet cleaning block is more preferably between 5:1 and 1:5. The weight ratio of the water-soluble salt to the water-insoluble salt having the same anion in phase 2 of the toilet cleaning block is most preferably between 3:2 and 2:3.

A preferred water-soluble salt in the practice of the invention is sodium carbonate.

A preferred water-insoluble salt for the purposes of the invention is calcium carbonate.

The total amount of water-insoluble salt in phase 1 is 1-10% by weight based on all components present in phase 1.

The cleaning blocks according to the invention contain 5-50% by weight, preferably 10-30% by weight, of salt, based on the total components of both phases, including the anions present.

Alcohol ethoxylate

The toilet cleaning blocks according to the invention may contain alcohol ethoxylate. The alcohol ethoxylate used according to the invention is preferably ethoxylated with up to 8 moles of alkylene oxide, more preferably up to 5 moles of alkylene oxide.

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- 4 .:.. : ·τ·„· /\z alcohol ethoxylate preferably contains a carbon chain of 8-22 carbon atoms, more preferably 8-16 carbon atoms. The alcohol ethoxylate is preferably branched chain.

The alcohol ethoxylate preferably has a hydrophilic/lipophilic balance value (HLB) of at most 12, more preferably at most 10, most preferably at most 8.

The cloud point of alcohol ethoxylate is less than 65 when measured in a 1% by weight aqueous solution.

The amount of alcohol ethoxylate in the cleaning block is preferably less than 5% by weight of the total block. The alcohol ethoxylate is more preferably in a separate phase (i.e., phase 1) from the fragrance. The amount of alcohol ethoxylate is preferably 0.5-6% by weight of the total composition (i.e., both phases), more preferably 1.5-4% by weight.

Bleaching agents

Cleaning blocks typically contain up to 50% by weight of at least a slightly water-soluble bleach. Bleaches are more typically present in the product in amounts of 2-30% by weight. The term bleach is used herein to mean both bleach and bleach precursor, the latter being understood to mean, unless otherwise indicated, a bleach-forming substance.

Suitable bleaching agents are bleaching agents containing reactive halogen and reactive oxygen, in particular so-called halogen-releasing agents.

Chlorine-containing bleaching agents are preferred. Suitable water-soluble, reactive chlorine-containing bleaching agents according to the invention include:

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A particularly preferred bleaching agent is sodium dichlorocyanurate (NaDCCA). The bleaching agent is typically present in an amount of 10-30% by weight, with a most preferred nominal amount of 25% by weight. A suitable bleaching agent has been found to be the product under the trade name Oxidan DCN/WSG (manufacturer: Sigma).

In a particularly preferred embodiment of the invention, the bleaching agent is in the same phase as the water-insoluble salt (in phase 1).

Anionic surfactants

The composition preferably also contains a surfactant which is anionic in nature. This surfactant provides a cleansing and foaming effect.

Suitable anionic surfactants include alkali metal or ammonium alkylarylsulfonates (especially alkylbenzenesulfonates), alkane sulfonates, alkyl sulfates, and sarcosinates.

It has been found that improved foaming properties are obtained by using a surfactant system comprising a primary alkyl sulfate (PAS) together with other anionic surfactants. According to the invention, a toilet cleaning block preferably comprises 1-15% by weight (more preferably 1-5%) of a primary alkyl sulfate and 15-50% by weight (more preferably 30-50%) of other anionic surfactants. It has been found that the use of such a mixed surfactant system is advantageous,

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- 6 0 · ·*··· « «· · · · · because it reduces the stickiness of the cleaning block during production. Cleaning blocks containing 1-5% by weight of the PAS component show improved wear characteristics.

Said other anionic surfactants are preferably sulfonates. Alkylbenzene sulfonate (ABS) is one suitable sulfonate. It is believed that a relatively small amount of PAS and a larger amount of ABS together promote foaming and the release of the fragrance from the cleaning block.

The total amount of surfactant, if present, may vary widely. In practice, the composition will generally contain from 10 to 70% by weight of surfactant, more preferably from 20 to 50% by weight.

Production aids

As will be described in detail below, the preferred method of manufacture is extrusion. Optionally, the cleaning blocks of the invention also comprise a manufacturing aid to aid in extrusion. Suitable manufacturing aids include oils (including both mineral oils and silicone oils), esters (other than esters derived from unsaturated carboxyl-containing monomers containing olefinic linkages), alcohol ethoxylates and polybutene.

Fragrances

The cleaning blocks preferably contain 2-15% by weight of a hydrophobic, oily, liquid fragrance. The cleaning blocks more preferably contain 2-10% by weight, more preferably 3-6% by weight of fragrance. A nominal fragrance amount of 4% by weight is particularly preferred. This oily fragrance is typically described in EP 167 210

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- 7 '·ί· ·1·* of the type described in the document. It is clear that this oily liquid perfume material must be stable in the presence of the water-soluble, active chlorine-containing bleaching agent. A suitable oily perfume material can be easily selected by testing it together with the water-soluble, active chlorine-containing bleaching agent.

In some cases, the toilet cleaning block may contain two fragrances, in which case it is preferred that the fragrance present in each phase is at least 80% of the total fragrance present in that phase. More preferably, different fragrances are present in each phase.

Suitable examples of bleach-stable fragrances include Verdeo 898, Bonanza 048, Ponderosa 431 (manufactured by IFF) and LB 132 (manufactured by Quest). Particularly preferred fragrances are Icebreaker Super Mod, Oxygen Supra Mod, Motebianco Supra and Lemonfit Supra (manufactured by Givaudan Roure).

Ingredients used in small quantities

Minor ingredients are usually present but are only used where appropriate. These include dyes and/or bleaching agents. These materials should be selected to be compatible with the bleaching agents and not to react significantly with them. Titanium dioxide is an acceptable bleaching agent. The amount of dyes and/or bleaching agents is typically not more than 5% by weight.

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Further improvement of the product can be achieved by adding chelating, complexing or water softening agents, which may be ethylenediaminetetraacetic acid or its derivatives, nitrilotriacetic acid, phosphonates or polyphosphates, metasilicates, boron heptonates, diethylenediaminedisuccinate, dipicolinic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid or lower molecular weight polymeric materials capable of inhibiting crystal growth. Additional reducing agents, such as alkali metal disulphates, may be present to reduce discoloration caused by metals, such as iron.

One phase of the cleaning blocks of the invention typically comprises 1-15% by weight, more preferably 2-10% by weight, of a dye on a support. It is preferred that the other phase of the cleaning block is fully colored. In both cases, it is preferred that the dye is water-soluble.

Polymers

The compositions of the invention may employ water-insoluble, gelling polymers. These polymers are polycarboxylic acids derived from monomers containing one or more olefinic bonds, particularly unsaturated carboxylic acids containing olefinic bonds, such as acrylic acid or maleic acid.

Suitable polymers include polyacrylic acid, polymaleic anhydride and their copolymers with ethylene, styrene and methyl vinyl ester. If polymer is present, it is preferably crosslinked. Polygel DB (manufacturer: 3V Sigma), which is a crosslinked, high molecular weight polyacrylate - nominal amount used is 2-3% by weight, has proven to be a suitable material.

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The compositions of the invention can be prepared by a number of methods. The so-called "hot-melt" method is suitable for preparing the compositions, among others, in which the fusible components of the individual phases of the block are melted, the additional components are added, and then the melt is poured into molds, or it is shaped into the desired final shape by a compression process, i.e. a process is used that includes forming a mixture of the components of the composition and then compressing the mixture into the desired shape. The two phases thus formed are then compressed together.

A particularly preferred process is an extrusion process in which mixtures of the components of each phase are coextruded into a solid rod or block which is then cut into pieces of the desired size.

It is noted that when the compositions of the invention are used as free-standing toilet cleaning blocks, their weight is suitably between 30 and 150 g. When a solid composition is extruded, it is generally advantageous, as mentioned above, to include some lubricant or manufacturing aid to aid extrusion. The weights of the individual phases are preferably approximately the same. (In this context, the term approximately means that the weights of the individual phases differ by no more than 20%, more preferably by no more than 10%.)

The compositions of the invention can also be brought into the desired form by a tabletting process.

In this description, the term block is not intended to limit the shape of the given product. In the case of water tank blocks, the rod

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J , ί τ, ' are cut into pieces whose length is short compared to their diameter.

The invention is illustrated in the following non-limiting examples. Examples according to the invention are indicated by numbers, while comparative examples are indicated by letters.

In the following examples, toilet cleaning blocks are produced by an extrusion process, in which a mixture of the components of the individual phases is co-extruded as a plasticized mass through a die opening into a rod, which is cut into tablets of appropriate size.

The composition of toilet cleaning blocks is shown in the following table.

components % by weight of the total block example The 1. 2. Phase 1 ABS ¹ 15 15 15 PATH ² 6 6 6 NaDCCA 11.25 11.25 11.25 C a C 0 3 4.4 4.4 4.4 _Na2SO4 4.3 4.3 4.3 alcohol ethoxylate 2EO ⁵ - - ³ ingredients used in small quantities Quantity required for 50% by weight

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·*> * · V * ♦ · 4 __> components % by weight of the total block example The 1. 2. Phase 2 ABS ¹ 17.4 17.4 17.4 PATH ² 2.5 2.5 2.5 C a C 0 3 11.3 9.2 5.1 _Na2S04 9.8 9.8 9.8 _Na2CO3 - 2.2 5.3 fragrancing additive 3.5 3.5 3.5 ingredients used in small quantities Quantity required for 50% by weight

ABS ¹ Nansa HS 80/L (manufacturer: Albright and Wilson)

PAS ² PAS-Empicol LZ-V trade name product (manufacturer: Albright and Wilson) colored sodium carbonate granules (manufacturer: Crossfield) alcohol ethoxylate 2EO ⁵ Loradac 2-24 2EO trade name product (manufacturer: DAC)

The service life of each block is determined by placing the blocks in a toilet, flushing them 250 times, and then determining the remaining mass of the block. The test results are shown in the following table.

It can be seen from the reported data that the disproportion between the two phases of the toilet cleaning block is smaller in the case of the cleaning blocks according to the invention.

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Claims (10)

- example phase 1 remaining from original array phase 2 remaining from original array (%) A 0 40 1. 0 35 2. 0 20 Patent claims 1. A toilet cleaning block comprising at least 2 phases, wherein a 1st phase comprises a water-insoluble salt as at least 50% by weight of the salt present therein, and a 2nd phase comprises a fragrance and a water-soluble salt, wherein the anion of the salts in the two phases is the same. 2. The toilet cleaning block of claim 1, wherein phase 2 further comprises a water-insoluble salt having an anion identical to the anion of the water-soluble salt. 3. A toilet cleaning block according to claim 2, wherein the weight ratio of the water-soluble and water-insoluble salt containing the same anion is between 5:1 and 1:5. 4. A toilet cleaning block according to any one of claims 1-3, wherein the second phase further comprises a bleaching agent. 5. A toilet cleaning block according to claim 4, comprising a halogen-releasing agent as a bleaching agent. 6. A toilet cleaning block according to claim 5, comprising sodium dichlorocyanurate as the bleaching agent. 94809-2227C/VO/LZs PCT/EP00/01184 7. A toilet cleaning block according to any one of claims 1-6, comprising sodium carbonate as the water-soluble salt. 8. A toilet cleaning block according to any one of claims 1-7, comprising calcium carbonate as a water-insoluble salt. 9. A toilet cleaning block according to any one of claims 1-8, wherein the amount of water-soluble salt containing the same anion as the water-insoluble salt in phase 2 is 1-10% by weight based on the total ingredients in phase 2. 10. A toilet cleaning block according to any one of claims 1-9, wherein the total amount of water-insoluble salt in phase 1 is 1-10% by weight based on all components in phase 1. UNILEVER N.V. instead of the authorized person: DANUBE Patent and Trademark Office Ltd. Dr. László Vitalis, patent attorney 94809-2227C/VO/LZS PCT/EP00/01184