WO2019052842A1

WO2019052842A1 - Shaped toilet cleaner block

Info

Publication number: WO2019052842A1
Application number: PCT/EP2018/073582
Authority: WO
Inventors: Rita Lodola; Olivier LONTOUO TAKEMLON; Ivan Valcarenghi
Original assignee: Unilever N.V.; Unilever Plc; Conopco, Inc., D/B/A Unilever
Priority date: 2017-09-14
Filing date: 2018-09-03
Publication date: 2019-03-21
Also published as: EP3681988B1; PL3681988T3; RS63950B1; EP3681988A1

Abstract

The invention relates to a shaped toilet cleaner block comprising: • a surfactant mix consisting essentially of alkyl benzene sulfonate and nonionic surfactant; • filler; and • colorant; wherein the block comprises from 0 to 3 wt% of other surfactants; wherein the weight ratio of alkyl benzene sulfonate to nonionic surfactant is from 9:1 to 3:1; and the colorant is selected from blue, green, red, orange, violet, pink and yellow.

Description

SHAPED TOILET CLEANER BLOCK

Field of the invention

The present invention relates to toilet cleaner blocks, more particularly to toilet cleaner blocks comprising a surfactant mix consisting of alkyl benzene sulfonate and nonionic surfactant.

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.

Colorants are commonly used in toilet cleaner blocks for aesthetic reasons but may also allow the consumer to asses if the block (still) releases enough actives in the flush water by the colour of said flush water. 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.

EP 3 168 284 A1 (Unilever) describes shaped toilet cleaner blocks comprising nonionic surfactant, alkyl benzene sulfonate, alkyl sulfate, optionally fatty acid

monoethanolamide and filler. The toilet cleaner block of a rim block is thus wetted, i.e. comes into contact with water, by the flush water when a toilet is flushed. If a toilet is not used regularly - or more precisely, not flushed regularly - the block may dry out, starting with the outer layer thereof. As a result, the appearance of the block may change, for example by the formation of drying spots that are visible like discolorations like for example white spots, and may not always be desired. This is more pronounced with coloured blocks, especially darker colours.

There is a need for coloured shaped toilet cleaner blocks that are less susceptible to changes in appearance if the toilet is irregularly flushed.

Summary of the invention

We have found that a shaped toilet block comprising a surfactant mix consisting of alkyl benzene sulfonate and nonionic surfactant having a weight ratio of alkyl benzene sulfonate to nonionic surfactant from 9:1 to 3:1 shows reduced formation of drying spots.

Accordingly, the present invention provides a shaped toilet cleaner block comprising:

• a surfactant mix consisting of alkyl benzene sulfonate and nonionic surfactant;

· filler; and

• colorant;

wherein the weight ratio of alkyl benzene sulfonate to nonionic surfactant is from 9:1 to 3:1 and wherein the block comprises from 0 to 3 wt% of other surfactants. 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 the use of a surfactant mix in a shaped toilet cleaner block according to the present invention to reduce post-flush drying spots. Detailed description of the invention

As used herein the term "comprising" encompasses the terms "consisting essentially of" and "consisting of. Where the term "comprising" is used, the listed steps or options need not be exhaustive. Unless otherwise specified, numerical ranges expressed in the format "from x to y" are understood to include x and y. Weight percentage (wt%) is calculated on total composition unless otherwise specified.

The 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 using an adhesive layer, like e.g. a gel strip, at the back of the toilet cleaner block and placing the toilet cleaner block directly on the inside of the toilet bowl. Alternatively, and preferably, the toilet cleaner block is placed in a suitable holder for placement under the toilet rim of the toilet bowl. The shaped toilet cleaner block according to the invention comprises:

• filler; and

• colorant;

wherein the weight ratio of alkyl benzene sulfonate to nonionic surfactant is from 9:1 to 3:1 and wherein the block comprises from 0 to 3 wt% of other surfactants.

Surfactants

The surfactant mix consists of alkyl benzene sulfonate and nonionic surfactant wherein the weight ratio of alkyl benzene sulfonate to nonionic surfactant is from 9:1 to 3:1. The shaped toilet cleaner block may comprise other surfactants as long as they do not materially affect the surfactant characteristics of said surfactant mix. For example, the shaped toilet cleaner block may comprise some additional anionic surfactant, like for example primary alkyl sulphate (PAS), as a processing aid to make the mix less sticky and allow for improved manufacturing. However, the total amount of other surfactants is from 0 to 3 wt%, preferably from 0 to 2 wt% and more preferably from 0 to 1 wt%. Even more preferably the surfactant mix consists of alkyl benzene sulfonate and nonionic surfactant and no other surfactants are present in the shaped toilet cleaner block. The weight ratio of alkyl benzene sulfonate to nonionic surfactant is from 9:1 to 3:1. So a weight ratio of 8:1 corresponds to a surfactant mix having 8 times more alkyl benzene sulfonate in weight than nonionic surfactant. Preferably the weight ratio of alkyl benzene sulfonate to nonionic surfactant is from 8:1 to 4:1 , and more preferably from 8:1 to 5:1 .

The toilet clear block preferably comprises from 20 to 60 wt% surfactant mix and more preferably from 30 to 50 wt%. Alkyl benzene sulfonate

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 Ce-ie alkyl benzene sulfonate and more preferably C10-14 alkyl benzene sulfonate. Sodium C10-14 alkyl benzene sulfonate is a preferred alkyl benzene sulfonate for use in the surfactant mix.

Nonionic surfactant

Examples of nonionic surfactant that may be employed in the surfactant mix of the present toilet cleaner block include fatty alcohol alkoxylates, ethylene oxide/propylene oxide block polymers, fatty acid alkanolamides, fatty acid polyglycol ethers, alkyl polyglycosides, fatty acid glucamides and combinations thereof. Preferably the nonionic surfactant of the surfactant mix comprises fatty alcohol alkoxylate. More preferably the surfactant mix comprises at least 50 wt% fatty alcohol alkoxylate, even more preferably at least 80 wt%, still more preferably at least 90 wt% and still even more preferably at least 95 wt%. The fatty alcohol alkoxylate preferably is selected from Cs-22 alcohols alkoxylated with ethylene oxide (EO) and/or propylene oxide (PO) with a degree of alkoxylation of 12 to 30. The fatty alcohol alkoxylate employed in the surfactant mix is preferably selected from alkoxylated C12-20 fatty alcohols, more preferably from alkoxylated C16-18 fatty alcohols.

The fatty alcohol alkoxylate in the surfactant mix is preferably selected from

ethoxylated fatty alcohols with a degree of ethoxylation of 16 to 28, even more preferably with a degree of ethoxylation of 20 to 27.

A preferred fatty alcohol alkoxylate is ethoxylated C16-18 fatty alcohol with a degree of ethoxylation of 24 to 26.

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.

Preferably the toilet cleaner block comprises 30 to 70 wt% filler, more preferably 35 to 65 wt% and even more preferably 40 to 60 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.

Colorant

The inclusion of a colorant in the toilet cleaner block not only serves to increase the appeal of the product, but it is also makes it easier to verify how much product is left after repeated flushes. Preferably, the toilet cleaner block comprises at least 10 mg/kg, more preferably at least 30 mg/kg and even more preferably at least 50 mg/kg of colorant.

The colorant is selected from blue, green, red, orange, violet, pink and yellow.

Especially preferred colorants are blue, green and yellow. It will be appreciated that the advantages of the present invention will be more pronounced for toilet cleaner blocks of certain colors than for other colors.

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.

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 perfume, bleaching agents, polymers, corrosion inhibitors, flush regulators, adhesion inhibitors, pH regulators, enzymes and preservatives. 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.

Use of surfactant mix

The present invention further provides for the use of a surfactant mix in the shaped toiled cleaner block of the present invention to reduce post-flush drying spots. The surfactant mix consists essentially of alkyl benzene sulfonate and nonionic surfactant in a weight ratio of alkyl benzene sulfonate to nonionic surfactant from 9:1 to 3:1 .

Preferably the weight ratio of alkyl benzene sulfonate to nonionic surfactant is from 8:1 to 4:1 , and more preferably from 8:1 to 5:1 .

Is was surprisingly found that such a surfactant mix reduces the formation of post-flush drying spots. This is especially noticeable on colored toilet blocks, and especially with colors like for example blue, green and yellow, where such post-flush drying spots are visible as white spots. Such white spots are thus reduced.

The invention is further illustrated by the following non-limiting examples.

Examples

Shaped toilet cleaner blocks (according to the present invention and comparative examples) where made by mixing the ingredients followed by extrusion. Compositional details are provided in Tables 1A to 1 C.

Table 1A - green toilet cleaner blocks

Ingredients (wt%) 1 2 A

Sodium dodecylbenzene sulfonate 29 29 24

Nonionic surfactant: alcohol ethoxylate(#) 4 4 4,5

Sodium Lauryl Sulphate - 1.01 15,03

Water - - 0,22

Green Polymeric colorant 0,028 0,028 0,028

Perfume 3,5 3,5 4

Sodium sulphate To 100 To 100 To 100 (#) An alkyl polyethylene glycol ether made from a linear, saturated C16-18 fatty alcohol having a nominal degree of ethoxylation of 25.

Table 1 B - blue toilet cleaner blocks

(#) An alkyl polyethylene glycol ether made from a linear, saturated C16-18 fatty alcohol having a nominal degree of ethoxylation of 25.

Table 1 C - yellow toilet cleaner blocks

Test conditions

Toilet blocks where made by mixing the ingredients and subsequent extrusion, both under controlled heat process.

Each toilet block was placed in a toilet bowl such that it was wetted when the toilet was flushed.

The toilet was flushed 3 times to make the toilet block wet. The toilet block was then left and allowed to dry.

The temperature and humidity of the room are measured during each assessment stages.

The toilet blocks were then visually assessed for white spots after a specific time interval and graded as low / medium /high.

The results are summarized in Tables 2A and 2B.

Table 2A - results

Table 2B - results

Assessment after 6 days

Example /

Comparative Visual Ranking of Humidity

T (°C)

White Spots (%)

1 low

2 low 22,4° 30

A medium/high

3 low

4 low 22,4° 30

B medium/high

5 low

6 low 22,5° 30

C medium/high

Claims

1. Shaped toilet cleaner block comprising:

• a surfactant mix consisting of alkyl benzene sulfonate and nonionic

surfactant;

• filler; and

• colorant;

wherein the block comprises from 0 to 3 wt% of other surfactants;

wherein the weight ratio of alkyl benzene sulfonate to nonionic surfactant is from

9:1 to 3:1 ; and

2. Toilet cleaner block according to claim 1 wherein the weight ratio of alkyl benzene sulfonate to nonionic surfactant is from 8:1 to 4:1 , and preferably from 8:1 to 5:1.

3. Toilet cleaner block according to claim 1 or 2 comprising 20 to 60 wt%, and

preferably 30 to 50 wt% surfactant mix.

4. Toilet cleaner block according to any one of claims 1 to 3 wherein the alkyl

benzene sulfonate comprises, and preferably is, Cs-is alkyl benzene sulfonate.

5. Toilet cleaner block according to any one of claims 1 to 4 wherein the nonionic surfactant comprises, and preferably is, fatty alcohol alkoxylate selected from Cs-22 alcohols alkoxylated with ethylene oxide (EO) and/or propylene oxide (PO) with a degree of alkoxylation of 12 to 30.

6. Toilet cleaner block according claim 5 wherein the fatty alcohol alkoxylate is

selected from alkoxylated C12-20 fatty alcohols, and preferably from alkoxylated C16- 18 fatty alcohols.

7. Toilet cleaner block according to claims 5 or 6 wherein the fatty alcohol alkoxylate is selected from ethoxylated fatty alcohols with a degree of ethoxylation of 16 to 28, preferably 20 to 27.

8. Toilet cleaner block according to any one of claimsl to 7 comprising 30 to 70 wt% filler, preferably 35 to 65 wt%, and more preferably 40 to 60 wt%.

9. Toilet cleaner block according to any one of claims 1 to 8 wherein the filler is an inorganic salt selected from sulphates, carbonates, halides, phosphates and combinations thereof.

10. Toilet cleaner block according to any one of claims 1 to 8 wherein the filler is

sodium sulphate.

1 1. Toilet cleaner block according to any one of claims 1 to 10 wherein the colorant is a polymeric colorant, pigment dispersion colorant or a combination thereof.

12. Toilet cleaning system comprising at least one toilet cleaner block according to any one of claims 1 to 1 1 and a holder suitable for positioning the toilet cleaner block in a toilet bowl such that it is wetted when the toilet is flushed.

13. Use of a surfactant mix in a shaped toilet cleaner block according to any one of claims 1 to 1 1 to reduce formation of post-flush drying spots.