EP4305137B1

EP4305137B1 - Shaped toilet cleaner block

Info

Publication number: EP4305137B1
Application number: EP22711020.2A
Authority: EP
Inventors: Koushik ACHARYA; Olivier LONTOUO TAKEMLON; Michele STEFANONI; Ivan Valcarenghi
Original assignee: Unilever Global IP Ltd; Unilever IP Holdings BV
Current assignee: Unilever Global IP Ltd; Unilever IP Holdings BV
Priority date: 2021-03-08
Filing date: 2022-03-07
Publication date: 2024-10-09
Anticipated expiration: 2042-03-07
Also published as: PL4305137T3; AU2022233243A1; AU2022233243A9; AU2022233243B2; EP4305137A1; EP4305137C0; CN116888247A; ZA202307103B; BR112023018010A2; WO2022189340A1

Description

Field of the invention

The present invention relates to toilet cleaner blocks, more particularly to toilet cleaner blocks comprising a surfactant mix of alkyl benzene sulfonate, primary alcohol sulphate and alkyl poly glycoside.

Background of the invention

Toilet cleaner blocks are commonly used to impart cleansing and/or other components to the flush water of toilets, like lavatories or urinals. Such blocks may be immersed in the water tank (so called in-tank blocks or cistern blocks) or held under the rim of a toilet in a suitable holder for intermittent contact of the toilet cleaner block with flush water (so called rim blocks).
Rim blocks typically contain active ingredients such as surfactants, perfume, acids, bases, salts, thickeners, antimicrobials, preservatives, sequestrants, bleaching agents, corrosion inhibitors, flush regulators, enzymes, microorganisms, active substances for biofilm removal, lime-scale inhibitors, soil-adhesion inhibitors etc. Rim blocks also often contain a substantial amount of filler, such as sodium sulphate or sodium carbonate.
Solid toilet blocks are typically manufactured and shaped by an extrusion process. In case of rim blocks the shaped toilet blocks may be inserted into a suitable holder, like for example a basket, for use in the toilet bowl.
In-use characteristics of a toilet block include:

Lifespan - how long the block lasts, usually measured as number of flushes before the block is completely dissolved;
3D shape - how the 3D shape of the block changes during its lifetime. The block gradually dissolves under the influence of flush water. Ideally the block dissolves symmetrically such that the overall 3D shape of the block is maintained during its lifetime. It may happen that a block dissolves asymmetrically, for example one side erodes excessively, the block develops holes, or may become porous such that part of the block breaks off;
Foam development - how much visible foam develops during a flush as well as how much and how long visible foam is present after a flush. This is usually measured as cm of foam;
Fragrance performance - fragrance development during a flush as well a fragrance perception between flushes.

Existing toilet block formulations may not always address all of the above mentioned in-use characteristics. Usually there is a trade-off between these in-use characteristics. For example, a harder toilet block will have a longer lifespan but may not perform well on foam development.
US2012047640 discloses malleable toilet cleaner compositions comprising a) perfume; b) at least one nonionic surfactant; c) at least one alkyl benzene sulphonate; and d) at least one olefin sulfonate.
WO2019/052842 discloses shaped toilet cleaner blocks comprising a surfactant system consisting of alkyl benzene sulphonate and nonionic surfactant wherein the nonionic surfactant preferably is a fatty alcohol alkoxylate.
EP3168284 A1 , US5759974 A , DE 19817509 A1 , US2016/251840 A1 and US 2010/299818 A1 disclose shaped toilet blocks comprising a surfactant system, wherein the surfactant system comprises a mixture of anionic and nonionic surfactants.
Despite efforts thus far, there is still a need for shaped toilet cleaner blocks with improved in-use characteristics.

Summary of the invention

We have found that shaped toilet cleaner blocks comprising a surfactant system of alkyl benzene sulphonate, primary alcohol sulphate and alkyl poly glycoside allow for improved in-use characteristics.
Accordingly, in a first aspect the invention relates to a shaped toilet cleaner block comprising:

a. a surfactant mix comprising:
- i. 10 to 30 wt% alkyl benzene sulphonate;
- i. 1 to 25 wt% primary alcohol sulphate;
- i. 1 to 15 wt% alkyl poly glycoside;
b. 30 to 85 wt% filler;
c. 0 to 7 wt% polyol with a carbon chain length of 2 to 4;
d. 0 to 2 wt% water;

The invention further provides a toilet cleaning system comprising at least one toilet cleaner block according to the present invention and a holder suitable for positioning the toilet cleaner block in a toilet bowl such that it is wetted when the toilet is flushed.
The invention also provides for a method of making the shaped toilet cleaner block according to the present invention comprising the steps of

a. providing the alkyl poly glycoside as a solid;
b. mixing the ingredients;
c. extruding the mixed ingredients.

Detailed description of the invention

Any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of." In other words, the listed steps or options need not be exhaustive. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about". Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "x to y", it is understood that all ranges combining the different endpoints are also contemplated. Unless specified otherwise, amounts as used herein are expressed in percentage by weight based on total weight of the composition and is abbreviated as "wt%". The use of any and all examples or exemplary language e.g. "such as" provided herein is intended merely to better illuminate the invention and does not in any way limit the scope of the invention otherwise claimed. Room temperature is defined as a temperature of about 20 degrees Celsius.
The shaped toilet cleaner block of the present invention preferably is designed for use as a rim block, where the toilet cleaner block is positioned in the toilet bowl such that it is wetted when the toilet is flushed. This may be achieved by placing the toilet cleaner block directly on the inside of the toilet bowl, optionally with the use of an adhesive layer, like e.g. a gel strip, at the back of the toilet cleaner block. Alternatively, and preferably, the toilet cleaner block is placed in a suitable holder for placement under the toilet rim of the toilet bowl.

Surfactant ratios

The toilet cleaner block comprises a surfactant mix comprising alkyl benzene sulphonate, primary alcohol sulphate and alkyl poly glycoside surfactant. It was surprisingly found that specific weight ratios of these surfactants allow for toilet cleaner blocks with improved and better balanced in-use characteristics, including life span, foam development and retention of 3D shape.
Preferably the toilet cleaner block comprises 12 to 65 wt% surfactant mix, more preferably 15 to 60 wt%, even more preferably 20 to 50 wt% and still even more preferably 25 to 40 wt%.
The weight ratio of (alkyl benzene sulphonate + alkyl poly glycoside)/primary alcohol sulphate is from 0.5:1 to 7:1. Preferably the weight ratio of (alkyl benzene sulphonate + alkyl poly glycoside)/primary alcohol sulphate is from 0.5:1 to 6:1, more preferably 1:1 to 6:1 and even more preferably from 1:1 to 5.5:1.

Alkylbenzene sulphonates (ABS)

Alkylbenzene sulphonates (ABS) and derivatives thereof include water-soluble alkali metal salts of organic sulphonates having alkyl radicals typically containing from about 8 to about 22 carbon atoms, preferably 8 to 18 carbon atoms, still more preferably 12 to 15 carbon atoms and may be saturated or unsaturated. Examples include sodium salt of linear alkylbenzene sulphonate, alkyl toluene sulphonate, alkyl xylene sulphonate, alkyl phenol sulphonate, alkyl naphthalene-sulphonate, ammonium diamylnaphthalene-sulphonate and sodium dinonylnaphthalene-sulphonate and mixtures with olefin sulphonates.
The alkyl benzene sulfonate employed in the surfactant mix preferably is a salt selected from alkali metal salts, earth alkaline metal salts, ammonium salts and combinations thereof. More preferably, the alkyl benzene sulfonate is an alkali metal salt, most preferably a sodium salt.
Preferably the alkyl benzene sulfonate is C_8-18 alkyl benzene sulfonate and more preferably C_10-14 alkyl benzene sulfonate. Sodium C_10-14 alkyl benzene sulfonate is a preferred alkyl benzene sulfonate for use in the surfactant mix.
The surfactant mix comprises 10 to 30 wt% alkyl benzene sulphonate calculated on total weight of toilet cleaner block, preferably 10 to 25 wt% alkyl benzene sulphonate and more preferably 15 to 20 wt%.

Primary alcohol sulphate

The primary alcohol sulphate is a surfactant of the formula (Formula I):

(R₁-O-SO₃ ^-)_xM^x+,

wherein:

R₁ is saturated or unsaturated C8-C16, preferably C12-C14 alkyl chain; preferably, R₁ is a saturated C8-C16, more preferably a saturated C12-C14 alkyl chain;
x is equal to 1 or 2;
Mx+ is a suitable cation which provides charge neutrality selected from sodium, calcium, potassium and magnesium.

Examples of primary alcohol sulphate include sodium lauryl sulphate. Suitable examples include alkyl sulphates from synthetic origin with trade names Safol 23, Dobanol 23A or 23S, Lial 123 S, Alfol 1412S, Empicol LC3, Empicol 075SR. Further suitable examples, and preferred, include alkyl sulphates commercially available from natural sources with trade names Galaxy 689, Galaxy 780, Galaxy 789, Galaxy 799 SP.
The surfactant mix comprises 1 to 25 wt% primary alcohol sulphate calculated on total amount of toilet cleaner block, preferably 5 to 20 wt%, more preferably 5 to 15 wt% and even more preferably 5 to 10 wt%.

Alkyl polyglycoside surfactant

As used herein alkyl poly glycosides are compounds according to the formula (Formula II): R₁O(R₂O)_b(Z)_a, wherein R₁ is a alkyl radical, having from about 1 to about 30 carbon atoms; R₂ is an alkylene radical having from 2 to 4 carbon atoms; Z is a saccharide residue having 5 or 6 carbon atoms; b is a number having a value from 0 to about 12; and a is a number having a value from 1 to about 6 (the degree of polymerization). Due to the method by which they are synthesized, alkyl poly glycosides are generally present as mixtures of alkyl poly glycosides having varying amounts of carbon atoms in the alkyl radical and varying degrees of polymerization. Thus, when referring to alkyl poly glycosides, the alkyl radical is generally referred to as having a range of carbon atoms (e.g. C4/22 referring to a range of alkyl radicals having from 4 to 22 carbon atoms) and the degree of polymerization is generally referred to as the average degree of polymerization of the mixture.
Prefered alkyl poly glycosides suitable for use in the disclosed toilet cleaner block include those having the formula II wherein Z is a glucose residue, b is zero, R₁ is an alkyl group that contains 4 to 22 carbon atoms, and the average value of a is about 1 to 2. Preferably R₁ is an alkyl group that contains 8 to 18 carbon atoms, and more preferred R₁ is an alkyl group that contains 10 to 16 carbon atoms and the average value of a is about 1 to 2. Such alkyl poly glucosides are commercially available, for example, as GLUCOPON branded alkyl poly glucoside compositions from Cognis Corporation.
The surfactant mix comprises 1 to 15 wt% alkyl poly glycoside calculated on total amount of toilet cleaner block, preferably 2 to 12 wt%, more preferably 3 to 10 wt% and even more preferably 4 to 8 wt%.

Further surfactants

The toilet cleaner block may comprise further surfactants in addition to the surfactants making up the defined surfactant mix as above. The total amount of further surfactants is from 0 to 10 wt%, preferably 0.5 to 8 wt% and more preferably 1 to 5 wt%.
Further surfactants may include further anionic surfactants in addition to the alkyl benzene sulphonate and primary alcohol sulphate, further nonionic surfactants in addition to the alkyl poly glycoside, amphoteric surfactants and combinations thereof.
Examples of further anionic surfactants include alkyl sulfoacetate like e.g. sodium lauryl sulfoacetate, alkyl isothionae like e.g. sodium coco-isothionate, alky taurate like e.g. sodium methyl cocoyl taurate, secondary alkane sulphonate and alpha olefin sulphonate like e.g. sodium C14-16 alpha olefin sulphonate. Examples of further nonionic surfactants include cocamide monoethanolamine (CMEA) and alcohol ethoxylates. Examples of amphoteric surfactant include betaines and aminoxide surfactant.

Fillers

Preferably the filler in the toilet cleaner block is an inorganic salt selected from sulphates, carbonates, halides, phosphates and combinations thereof. More preferably, said inorganic salt is selected from sulphates, carbonates and combinations thereof.
The inorganic salt that may be employed as a filler in the toilet cleaner block is preferably selected from alkali metal salts, earth alkaline metal salts, ammonium salts and combinations thereof, even more preferably it is selected from alkali metal salts, most preferably it is selected from sodium salts.
The toilet cleaner block comprises 30 to 85 wt% filler. Preferably the toilet cleaner block comprises 35 to 80 wt% filler, more preferably 40 to 75 wt% and even more preferably 45 to 70 wt%.
In a preferred toilet cleaner block of the present invention the filler contains at least 50 wt%, preferably at least 80 wt%, more preferably at least 90 wt% and even more preferably at least 95 wt% sodium sulphate.

Polyol

The toilet cleaner block comprises from 0 to 7 wt% polyol with a carbon chain length of 2 to 4. The polyol provides for processability on an extrusion line. Suitable polyols include ethylene glycol, propylene glycol, 1,3-propanedio, glycerol, 1,3-butanediol, 1,2-butanediol, 1,4-butanediol, 2,3-butanediol and combinations thereof. Preferably the polyol has a carbon chain length of 3 and more preferably is glycerol.
Preferably, the toilet cleaner block comprises 0.1 to 5 wt% polyol, more preferably 0.2 to 3 wt%, even more preferably 0.25 to 2 wt% and still even more preferably 0.3 to 1 wt%.

Water

To aide processability the toilet cleaner block should not contain more than 2 wt% water. Preferably the amount of water is 0 to 1 wt% and more preferably 0 to 0.5 wt%.

Further ingredients

The toilet cleaner block of the present invention may comprise further ingredients like for example builder.

Builder

Examples of builders that may be included in the toilet cleaner block include low molecular weight polycarboxylic acids and salts thereof, the homopolymeric and copolymeric polycarboxylic acids and salts thereof, citric acid and salts thereof, carbonates, phosphates, silicates, zeolites and combinations thereof.
Preferably, the toilet cleaner block contains 0.5 to 20 wt%, more preferably 0.8 to 15 wt%, and even more preferably 1 to 10 wt.% builder.
A preferred toilet cleaner block contains at least 0.8 wt%, preferably at least 1 wt% of builder selected from phosphate, citrate and combinations thereof.

Other ingredients

Other ingredients that may applied in the toilet cleaner block of the present invention include colorant, perfume, bleaching agents, polymers, corrosion inhibitors, flush regulators, adhesion inhibitors, pH regulators, enzymes and preservatives.
The toilet cleaner block may be colored using any conventional means of coloring in the area of toilet block compositions but preferably the colorant is a polymeric colorant, or pigment dispersion colorant. Preferably the toilet cleaner block comprises 0 to 3 wt% colorant, more preferably 0.01 to 2 wt%.
Perfume or fragrance may be present in an amount of 0 to 7 wt%, preferably 0.1 to 6 wt% and more preferably 0.5 to 5 wt%.
Bleaching agents that may suitably be applied in the toilet cleaner blocks of the present invention include bleach hypo chlorite donors, peroxides, peracids and/or perborates. A bleach activator can also be used in addition to the bleaching agent.
Polymers, such as acrylic polymers, can suitably be incorporated in the toilet cleaner block to reduce formation of lime scale and soil re-deposition.
Flush regulators can be employed in the toilet cleaner block to regulate degradation of the block. Solid long-chain fatty acids, such as stearic acid, are preferred regulators.
Enzymes that may be applied in the toilet cleaner block include proteases, lipases, amylases, hydrolases and/or cellulases.

Toilet cleaning system

The present invention also provides for a toilet cleaning system comprising at least one toilet cleaner block according to present invention and a holder suitable for positioning the toilet cleaner block in a toilet bowl such that it is wetted when the toilet is flushed.
The holder is to be understood as a separate holder that can be attached and removed from the toilet bowl and as such is not an integral part of or the toilet bowl itself.
The holder may be configured such that it is refillable, such that part or all or the blocks can be replaced and the holder re-used.
The toilet cleaning system preferably contains from 1 to 5 toilet cleaner blocks of which at least one is a toilet cleaner block according to the present invention.
A preferred toilet cleaning system comprises:

at least one holder configured to hold said toilet cleaner block;
an inlet opening in the upper portion of said holder, said inlet being configured to allow toilet flush water to enter the container when said system is positioned under the rim of a toilet bowl in the path of toilet flush water and said toilet is flushed;
an outlet opening molded into a lower portion of said holder, said outlet being configured to drain toilet flush water from the holder into said toilet bowl.

Method of making

The present invention further provides for a method of making a shaped toilet cleaner block according to the present invention comprising the steps of:

To allow for the improved in-use characteristics, the current shaped toilet cleaner block comprises a specific surfactant mix. To suitably make the toilet cleaner block the alkyl poly glycoside surfactant is preferably provided as a solid that does not contain a noticeable amount of water.
The invention is further illustrated by the following non-limiting examples.

Examples

Lifespan test protocol

To determine the number of flushes a toilet rim block the following protocol is used.

A 5 chamber toilet rim cage (Domestos Power 5) is filled with 5 extruded hexagonally shaped blocks of 11 gram each.
Three different flush type toilets are used:
- ∘ Laminar water flow type toilet (ex Ideal Standard);
- ∘ Back to front water flow type toilet (ex KOL·O);
- ∘ Turbulent water flow type toilet (ex Villeroy & Boch).
The filled rim cage is placed inside the toilet where the maximum water flow is. Per toilet type 3 tests are done resulting in 9 tests in total (3 tests x 3 toilets).
The toilet is flushed using water having a hardness of 24° F. The water is at room temperature.
The toilet is flushed 15 times at regular intervals during an time period of 14.5 hours followed by 9.5 hours without flushing.
Flushing is repeated until all toilet blocks are completely dissolved.
The average number of flushes is then calculated based on the data of the 9 tests.

Foam profile protocol

To determine the foam profile the following protocol is used.

A filled rim cage is prepared and placed in the toilet as for the lifespan test protocol.
After the toilet is flushed the height of the foam in the toilet is determined by measuring the foam height taking the water line as off set (i.e. zero point).
The foam height is measured at T=0 (i.e. right after flushing) and at T=5 minutes (i.e. 5 minutes after flushing). Average foam height is the average of foam height at T=0 and T=5 minutes.
The foam height is reported in cm.

It will be appreciated that the lifespan test protocol and foam profile protocol can be used as such for a given formulation/product but ideally are used for comparing between different formulations/products such that these formulations/products are subjected to the exact same conditions allowing for a proper comparison and eliminating any influence of variations in temperature in the test room, water temperature, water pressure during flushes, exact position of block inside of toilet and type of toilet.

Example 1

Toilet cleaner blocks according to the present invention were manufactured by means of extrusion on the basis of the formulations shown in Table 1.
The extrusion conditions employed during manufacture were: Extrusion speed:
1 m/minute; Extrusion temperature: 56-60 °C; and Cutting frequency 45 pieces/minute. The shaped toilet blocks had a hexagonal cylindrical shape of 21 mm (height) x 21 mm (widest diameter); and 11 gram in weight.

The lifespan and foam profile of the toilet blocks was determined using the protocols as described above. The results are shown in Table 1.

TABLE 1 (wt% calculated on total product)

Ingredient	1	2	3	4	5	6	7
C10-13 linear alkyl benzene sulphonate ¹	15	15	15	15	15	15	20
C10-C16 alkyl polyglucoside ²	5	5	5	5	5	7.5	7.5
Sodium lauryl sulphate	20	15	10	6.5	5	5	5
Color	0.035	0.035	0.035	0.035	0.035	0.035	0.035
Fragrance	3	3	3	3	3	3	3
Glycerol	0.4	0.4	0.4	0.4	0.4	0.5	0.4
Sodium sulphate	To 100	To 100	To 100	To 100	To 100	To 100	To 100

(ABS+APG):PAS	1	1.33	2	3.08	4	4.5	5.5

Block weight (gram)	5x11	5x11	5x11	5x11	5x11	5x11	5x11
Foam height post flush (cm)	2.55	2.1	1.73	2.05	1.11	0.98	1.96
Foam height after 5 minutes (cm)	1.25	1.1	0.88	0.92	0.72	0.63	1.01
Average foam height (cm)	1.9	1.6	1.3	1.5	0.9	0.8	1.5
Lifespan (number of flushes)	283	296	354	302	465	465	338

¹ Ufaryl^® C3 ex Unger Fabrikker A.S.; ² Glucopon^® 50G ex BASF

Example 2 (comparative)

Toilet cleaner blocks were manufactured by means of extrusion on the basis of the formulations shown in Table 2.

The toilet blocks were manufactured and tested according to the conditions and protocols used for Example 1. The results are shown in Table 2.

TABLE 2 (wt% calculated on total product)

Ingredient	A	B	C	D	E
C10-C13 linear alkyl benzene sulphonate ¹	17.5	15	15	20	24
C10-C16 alkyl polyglucoside ²	11.25	7.5	15	15	-
Sodium lauryl sulphate	2.5	-	-	-	15
C12-C18 fatty acid amido alkyl betaine ³	2.5	-	5	5	-
Alkyl ethoxylate 25EO ⁴	-	-	-	-	5
Color	0.035	0.035	0.035	0.035	0.035
Fragrance	3	3	3	3	3
Glycerol	0.4	0.4	0.4	0.4	0.4
Sodium sulphate	To 100	To 100	To 100	To 100	To 100

(ABS+APG):PAS	11.5	-	-	-	NA

Block weight (gram)	5x11	5x11	5x11	5x11	5x11
Foam height post flush (cm)	0.77	0.55	0.5	0.5	1
Foam height after 5 minutes (cm)	0.48	0.42	0.5	0.5	0.7
Average foam height (cm)	0.63	0.49	0.5	0.5	0.85
Lifespan (number of flushes)	435	521	315	480	270

¹ Ufaryl^® C3 ex Unger Fabrikker A.S.: ² Glucopon^® 50G ex BASF: ³ TEGO^® Betain CK D ex Evonik; ⁴ Lutensol AT 25 ex BASF

Example 3

Toilet cleaner blocks were manufactured by means of extrusion on the basis of the formulations shown in Table 3.
The toilet blocks were manufactured and tested according to the conditions and protocols used for Example 1. The results are shown in Table 3.

The formulation of Comparative F is identical to Comparative E. Example 8 according to the invention uses C10-C16 alkyl polyglucoside instead of the alkyl ethoxylate 25EO in Comparative F.

TABLE 3 (wt% calculated on total product)

Ingredient	F	8
C10-C13 linear alkyl benzene sulphonate ¹	24	24
C10-C16 alkyl polyglucoside ²	-	5
Sodium lauryl sulphate	15	15
Alkyl ethoxylate 25EO ⁴	5	-
Color	0.035	0.035
Fragrance	3	3
Glycerol	0.4	0.4
Sodium sulphate	To 100	To 100

(ABS+APG):PAS	-	1.93

Block weight (gram)	5x11	5x11
Foam height post flush (cm)	1.6	2.51
Foam height after 5 minutes (cm)	0.9	1.28
Average foam height (cm)	1.25	1.89
Lifespan (number of flushes)	232	325

¹ Ufaryl^® C3 ex Unger Fabrikker A.S.; ² Glucopon^® 50G ex BASF; ⁴ Lutensol AT 25 ex BASF

Claims

Shaped toilet cleaner block comprising:
a. a surfactant mix comprising:
i. 10 to 30 wt% alkyl benzene sulphonate;

ii. 1 to 25 wt% primary alcohol sulphate;

iii. 1 to 15 wt% alkyl poly glycoside;

b. 30 to 85 wt% filler;

c. 0 to 7 wt% polyol with a carbon chain length of 2 to 4;

d. 0 to 2 wt% water;
wherein the weight ratio of (alkyl benzene sulphonate + alkyl poly glycoside)/primary alcohol sulphate is from 0.5:1 to 7:1.
Toilet cleaner block according to claim 1 wherein the weight ratio of (alkyl benzene sulphonate + alkyl poly glycoside)/primary alcohol sulphate is from 0.5:1 to 6:1, preferably 1:1 to 6:1 and more preferably from 1:1 to 5.5:1.
Toilet cleaner block according to claim 1 or 2 comprising 12 to 65 wt% surfactant mix, preferably 15 to 60 wt%, more preferably 20 to 50 wt% and even more preferably 25 to 40 wt%.
Toilet cleaner bock according to any one of claims 1 to 3 comprising 10 to 25 wt% alkyl benzene sulphonate, preferably 15 to 20 wt%.
Toilet cleaner according to any one of claims 1 to 4 wherein the wherein the alkyl benzene sulfonate comprises, and preferably is, C8-18 alkyl benzene sulfonate.
Toilet cleaner block according to any one of claims 1 to 5 comprising 5 to 20 wt% primary alcohol sulphate, preferably 5 to 15 wt% and more preferably 5 to 10 wt%.
Toilet cleaner block according to any one of claims 1 to 6 wherein the primary alcohol sulphate is a surfactant of the formula (Formula I):

(R₁-O-SO₃ ^-)_xM^x+,

wherein:
R₁ is saturated or unsaturated C₈-C₁₆ alkyl chain;

x is equal to 1 or 2;

M^x+ is a suitable cation which provides charge neutrality selected from sodium, calcium, potassium and magnesium.
Toilet cleaner block according to any one of claims 1 to 7 comprising 2 to 12 wt% alkyl poly glycoside, preferably 3 to 10 wt% and more preferably 4 to 8 wt%.
Toilet cleaner block according to any one of claims 1 to 8 wherein the alkyl poly glycoside is a surfactant of the formula (Formula II) R₁O(R₂O)_b(Z)_a, wherein Z is a glucose residue, b is zero, R₁ is an alkyl group that contains 4 to 22 carbon atoms, and the average value of a is about 1 to 2.
Toilet cleaner lock according to any one of claims 1 to 9 comprising 35 to 80 wt% filler, preferably 40 to 75 wt% and more preferably 45 to 70 wt%.
Toilet cleaner block according to any one of claims 1 to 10 wherein the filler is an inorganic salt selected from sulphates, carbonates, halides, phosphates and combinations thereof, and preferably is sodium sulphate.
Toilet cleaner block according to any one of claims 1 to 11 comprising 0.1 to 5 wt% polyol, preferably 0.2 to 3 wt%, more preferably 0.25 to 2 wt% and even more preferably 0.3 to 1 wt%.
Toilet cleaner block according to any one of claims 1 to 12 wherein the polyol has a carbon chain length of 3 and preferably is glycerol.
Toilet cleaning system comprising at least one toilet cleaner block according to any one of claims 1 to 13 and a holder suitable for positioning the toilet cleaner block in a toilet bowl such that it is wetted when the toilet is flushed.
Method of making a shaped toilet cleaner block according to any one of claims 1 to 13 comprising the steps of:
a. providing the alkyl poly glycoside as a solid;

b. mixing the ingredients;

c. extruding the mixed ingredients.