Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
GEL COMPOSITIONS
Document Type and Number:
WIPO Patent Application WO/2017/215890
Kind Code:
A1
Abstract:
The present invention provides a gel composition, comprising at least 15 wt.% of a polyamide-based thickener. Suitably, the gel composition comprises an active ingredient, and the gel composition is suitable for delivering said active ingredient.

Inventors:
SMITH CHRISTOPHER FRANCIS (GB)
Application Number:
PCT/EP2017/062460
Publication Date:
December 21, 2017
Filing Date:
May 23, 2017
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
UNILEVER PLC (GB)
UNILEVER NV (NL)
CONOPCO INC DBA UNILEVER (US)
International Classes:
A61Q1/02; A61K8/04; A61K8/88; A61Q1/14; A61Q17/04; A61Q19/00; A61Q19/10
Domestic Patent References:
WO2002059181A22002-08-01
Foreign References:
US20030162938A12003-08-28
Other References:
CRODA ET AL: "THE USE OF ODOUR ABSORBING MATERIALS SUCH AS FORESTALL (TM) IN A (POLYAMIDE) GEL TO IMPROVE ODOUR ABSORPTION IN AN AIR FRESHENER OR DEODORANT", RESEARCH DISCLOSURE, vol. 613, no. 7, 1 May 2015 (2015-05-01), MASON PUBLICATIONS, HAMPSHIRE, GB, pages 1 - 5, XP007144049, ISSN: 0374-4353
ANONYMOUS: "SAFETY DATA SHEET OF FORESTALL-LQ-(MH) (Version 1.3)", 28 September 2016 (2016-09-28), pages 1 - 9, XP002771789, Retrieved from the Internet [retrieved on 20170705]
Attorney, Agent or Firm:
HARDY, Susan, Margaret (GB)
Download PDF:
Claims:
CLAIMS:

1. A gel composition, comprising an active ingredient and at least 15 wt.% of a polyamide-based thickener, wherein the water content of the gel composition is greater than 50%

2. A gel composition according claim 1 , wherein the gel composition is an aqueous gel composition.

3. A gel composition according to claim 1 or 2, wherein the polyamide-based thickener is a polyalkyleneoxy-terminated polyamide thickener.

4. A gel composition according to claim 3, wherein the polyalkyleneoxy-terminated polyamide thickener comprises a block copolymer of the following formula:

wherein, independently at each occurrence, R1 is selected from C1-22 hydrocarbon radicals; R2 is selected from C2-6 alkylene diradicals; R3 is selected from C2-52

hydrocarbon diradicals; where at least 50% of the R3 radicals have at least 34 carbons; R4 is selected from C2-36 hydrocarbon diradicals and C4-100 polyether diradicals; Z is selected from O and NH; x is an integer from 2 to 100; y is an integer from 1 to 10; z is an integer from 2 to 100.

5. A gel composition according to claim 4, wherein R1 is selected from C1-12 alkyl; R2 is selected from C2-6 alkylene, R3 is selected from C30-42 hydrocarbon groups where at least 50 mol% are C34 groups; and R4 is selected from C1-20 alkylene groups.

6. A gel composition according to claim 4, wherein R1 is selected from C1-4 alkyl; R2 is selected from -CH2CH(R2a)- where R2a is hydrogen, methyl or ethyl; R3 is selected from C30-42 hydrocarbon groups where at least 50 mol% are C34 groups; and R4 is -CH2CH2-.

7. A gel composition according to any one of the preceding claims, wherein the polyamide-based thickener has a weight average molecular weight of 15,000 to 25,000. 8. A gel composition according to any one of the preceding claims, wherein the polyamide-based thickener has a weight average molecular weight of 18,500 to 20,000.

9. A gel composition according to any one of the preceding claims, wherein the polyamide-based thickener has a softening point of 75°C to 125°C.

10. A gel composition according to any one of the preceding claims, wherein the active ingredient is 0.01 to 10 wt.% of a surfactant.

1 1 . A gel composition of claim 10, wherein the surfactant is a non-ionic surfactant.

12. A homecare product, comprising a gel composition according to any one of claims 1 to 1 1 .

13. A personal care product, comprising a gel composition according to any one of claims 1 to 1 1.

14. A method of making a gel composition according to any one of claims 1 to 1 1 , comprising: adding said polyamide-based thickener to a carrier composition. 15. A method of making a gel composition according to claim 13, wherein the polyamide-based thickener is a polyalkyleneoxy-terminated polyamide having a weight average molecular weight of 18,500 to 20,000, a softening point of 80°C to 100°C, an acid number of less than 15 and an amine number of less than 3.

Description:
GEL COMPOSITIONS

Technical field

The present invention relates to gel compositions, in particular gel compositions for use in homecare and personal care applications.

Background

It is known to provide homecare and personal care products in a gel format which releases an active ingredient (e.g. perfume, detergent) over time, or upon exposure to mechanical or chemical stimuli. For example, it is known to provide a cleaning gel which sticks to the bowl of a toilet and gradually dissolves with each flush, thereby releasing a cleaning agent. It is also known to provide an air freshening gel, which sits within a housing (e.g. cage) and gradually releases a fragrance by evaporation.

However, successful formation of gel compositions suitable for controlled delivery of active ingredients is not straightforward. To make such gels, it is common to modify the rheology of a carrier composition using a suitable thickening (gelling) agent. However, the gelling effect of the thickening agents can be sensitive to the particular active ingredient(s), and other components in the carrier composition. Conversely, the performance of the components in the carrier composition can be negatively impacted by the particular thickening agent used. Thus, it is common for the type and amount of thickening agent to be tailored to the specific carrier composition, in order to achieve the desired mechanical and chemical properties. Once formed, the mechanical and chemical properties must remain storage stable so as to allow the gel to be transported, stored, handled and subsequently used. For example, the gel must not display unwanted syneresis during storage (that is, expulsion or "bleeding" of liquid from the gel during storage), nor display unwanted changes in mechanical properties (such as changes in strength, rigidity and friability) over time or with changes in temperature, humidity or other environmental conditions. In view of this, the range of homecare and personal care products based on such gel compositions is relatively limited, and there remains a need to develop further gels with improved properties. Summary of the invention

In view of the above, it is an aim of the present invention to provide gel compositions which are suitable for delivering a range of active ingredients. In particular, it is an aim of the present invention to provide active-ingredient-containing gel compositions which are convenient for consumers to handle and use. To this end, the present inventors have sought to develop self-supporting gels which are sufficiently chemically and mechanically stable to be handled by consumers. Of particular interest are gels which can be smoothly spread or squashed, without requiring excessive force or crumbling.

For convenience, it is also an aim of the present invention to provide such gels in the form of a unit dose, such as a tablet or bolus, to allow precise "controlled" delivery of a desired amount of active ingredient, and avoid waste and spillage.

Accordingly, in a first aspect, the present invention provides a gel composition, comprising at least 15 wt.% of a polyamide-based thickener. Suitably, the gel composition comprises an active ingredient, and the gel composition is suitable for delivering said active ingredient.

The present inventors have found that compositions incorporating polyamide-based thickeners at levels of at least 15 wt.% can form solid, dry self-supporting gels suitable for being smoothly spread or squashed on a surface and delivering an active ingredient. Advantageously, the formation of these solid, dry gels is relatively insensitive to the nature of the active ingredient and other components in the composition, and can tolerate, for example, both non-ionic and cationic surfactants as active ingredients. In addition to versatility in the range of ingredients which can be tolerated, gel formation can also occur over a broad pH range. Given the challenging set of properties required for producing unit doses of self- supporting gels capable of being spread on surfaces, it was surprising that the gel compositions displayed suitable properties with a range of other components at a range of pH values. In this regard, the results observed with the polyamide-based thickener are in contrast to those observed for gels formed with other thickening technology. For example, compositions thickened with xanthan gum, gellan gum or acrylate copolymers were found to produce gels with insufficient solidity. Gels thickened with carrageenan were found to be incompatible with a range of carrier composition components (in particular surfactants) and pH conditions.

The upper limit for the amount of polyamide-based thickener may be, for example, 60 wt.%, 50 wt.%, 40 wt.%, 35 wt.%, 30 wt.% or 25 wt.%. Below 15 wt.% the resulting gels have insufficient structure and are broken down too easily to allow them to be spread on a surface.

Preferably, the polyamide-based thickener may be incorporated in the composition at a level of 15 to 25 wt.%. For example, the polyamide-based thickener may be incorporated into the composition at between 16 to 24 wt.%, 17 to 23 wt.%, 18 to 22 wt.%, or 19 to 21 wt.%. Advantageously, the present inventors have found that thickener incorporated in an amount of 20 wt.% leads to formation of gels which show particularly good

spreadability, and other mechanical properties. In particular, the gels may be solid and dry, and are not prone to breaking into small fragments when a spreading force is applied.

Thickener

The polyamide-based thickener is preferably an end-capped polyamide. Preferably, the polyamide-based thickener is a polyaklyleneoxy-terminated polyamide thickener. The polyalkyleneoxy-terminated polyamide thickener comprises or consists of a block copolymer of the formula hydrocarbon-polyalkyleneoxy-polyamide- polyalkyleneoxy- hydrocarbon. The "polyalkyleneoxy" group is a polyether group based on repeated alkyleneoxy units, such as -CH 2 CH 2 0-, -CH 2 CH2(CH 3 )0-. The block copolymer may have the following formula: wherein, independently at each occurrence, R 1 is selected from C1-22 hydrocarbon radicals; R 2 is selected from C2-6 alkylene diradicals; R 3 is selected from C2-52

hydrocarbon diradicals (preferably where at least 50 mol% of the R 3 radicals have at least 34 carbons); R 4 is selected from C2-36 hydrocarbon diradicals and C4-100 polyether diradicals; Z is selected from O and NH; x is an integer from 2 to 100; y is an integer from 1 to 10; and z is an integer from 2 to 100. The term "hydrocarbon group" is intended to refer to groups containing only carbon and hydrogen atoms. Suitable hydrocarbon groups are formed from one or more of aliphatic and aromatic moieties. Suitable aliphatic moieties are alkyl, alkylene, alkenyl, alkenylene, alkynyl, alkynylene, cylocalkyl, cycloalkylene, cycloalkenyl, cycloalkenylene, cycloalkynyl, and cycloalkynylene moieties. Exemplary alkyl moieties are methyl, ethyl, propyl, hexyl, and 2-ethylhexyl; while exemplary alkylene groups are monoradials such as methylidene (=CH2) and diradicals such as methylene (-CH2-), and ethylene (-CH2CH2-). Suitable aromatic moieties include, for example, phenyl, and naphthyl, and combinations thereof such as biphenyl. The hydrocarbon groups may be a combination of aromatic and aliphatic groups, such as benzyl, tolyl or xylyl.

The R 1 groups may be alkyl, such as C1-12 alkyl, in particular C1-4 alkyl. Optionally, each R 1 group is methyl.

The R 2 groups are C2-6 alkylene, in particular C2-4 alkylene. Optionally, each R 2 group is - CH2CH(R 2a )- wherein R 2a is selected from hydrogen, methyl and ethyl.

The R 3 groups may have at least 30 carbons, such as 30-42 carbons. Preferably, at least 50 mol% of the R 3 groups are C34 groups. For example, C34 groups may constitute at least 60 mol%, at least 70 mol%, at least 80 mol%, at least 90 mol% or at least 95 mol% of the R 3 groups. The R 4 groups may be hydrocarbon groups having, for example, 1-20 carbons, in particular 1 -10 carbons. For example, the R 4 groups may be C1-20 alkylene groups, C1-10 alkylene groups, or C2-6 alkylene groups. Optionally, at least 50% of the R 4 groups have 2 carbons. Preferably, the R 4 groups are ethylene groups (-CH2CH2-).

Alternatively, the R 4 groups may be polyether groups, i.e. groups having blocks containing the repeating formula -O-R 2 -, where R 2 is as defined above. Optionally, the block copolymer may have R 1 selected from C1-12 alkyl; R 2 selected from C2-6 alkylene, R 3 selected from C30-42 hydrocarbon groups where at least 50 mol% are C34 groups; and R 4 selected from C1-20 alkylene groups.

Optionally, the block copolymer may have R 1 selected from C1-4 alkyl; R 2 selected from -CH2CH(R 2a )- where R 2a is hydrogen, methyl or ethyl; R 3 selected from C30-42 hydrocarbon groups where at least 50 mol% are C34 groups; and R 4 groups which are -CH2CH2-.

The above block copolymers may be made by reacting together reactants comprising dimer acid, diamine, and a polyether having both hydrocarbon termination and

termination selected from amine, hydroxyl and carboxyl, according to the methods discussed in WO 02/059181.

The polyamide-based thickener may have a weight average molecular weight (M w ) of greater than 10,000, greater than 12,000, greater than 15,000; greater than 17,000, greater than 18,000, or greater than 18,500. The upper limit for the weight average molecular weight may be, for example, 25,000; 24,000; 23,000; 22,000; 21 ,000 or 20,000.

For example, the weight average molecular weight may be 15,000 to 25,000; 17,000 to

23,000; 18,000 to 22,000; 18,000 to 21 ,000; or 18,000 to 20,000; or 18,500 to 20,000.

Weight average molecular weights within these ranges are preferred, since the resulting gels are found to be dry and have good mechanical properties with comparatively low sensitivity to the other components and pH of the gel. A particularly good balance of properties is observed for polyalkyleneoxy-terminated polyamide polymers having a M w of -19,000, and hence ranges of 17,000 to 23,000; 18,000 to 22,000 and, in particular 18,500 to 20,000 are preferred. In particular, polymers having this range of molecular weights produced solid gels which displayed particularly good dryness, making them suitable for attaching to surfaces. These advantageous properties allow the gel compositions formed from polymers having this molecular weight range to be used in a variety of products and applications. In particular, it offers a possible general route to thickening known homecare and personal care products, so as to produce gelled compositions which can be used in new ways.

The weight average molecular weight is measured by preparing a solution of the copolymer or composition in a suitable solvent, e. g., tetrahydrofuran (THF) and identifying the retention time of the copolymer by gel permeation chromatography, and comparing that retention time to the retention times of solutions of polystyrene having known molecular weight characterizations.

The polyamide-based thickener may have a softening point of 50°C to 150°C, preferably 75°C to 125°C, more preferably 80°C to 100°C, most preferably 90°C to 100°C. The softening point may be determined by a Ring and Ball method, such as ISO 4625.

The polyamide-based thickener used in the gel compositions may have an acid number of less than 25, less than 20, preferably less than 15, more preferably less than 10. The skilled reader understands that the acid number corresponds to the mass of potassium hydroxide in milligrams required to neutralise one gram of the polyamide-based thickener. In instances where the polyamide-based thickener comprises a polyalkylkeneoxy- terminated polyamide copolymer of the formhydrocarbon-polyether-polyamide-polyether- hydrocarbon, the copolymer does not have any free carboxylic acid groups, and accordingly has an acid number of zero. However, when prepared from diacid, diamine and hydrocarbon-terminated polyether, some of the diacid may not react with the diamine and/or polyether, and accordingly the final product may have some unreacted carboxylic acid that will be responsible for the final product having an acid number greater than zero. Preferably, the product has a minor amount of this unreacted diacid, and thus only a small acid number. Esterification catalysts may be used to encourage all of the diacid to react with hydroxyl groups, so as to minimise the amount of free acid.

The polyamide-based thickener used in the gel compositions may have an amine number of less than 25, less than 20, less than 15, less than 10, less than 5, less than 3, less than 2 or less than 1 . The skilled reader understands that the amine number is determined by titration of amine acetate from the polyamide thickener by a dilute, typically 1 N, HCI solution, and is calculated according to (A N 56.1 )/g sample, where A is mL of HCI titrant consumed, N is the normality of HCI titrant and g is the sample weight in grams. In instances where the polyamide-based thickener comprises a polyalkylkeneoxy-terminated polyamide copolymer of the form hydrocarbon-polyether-polyamide-polyether- hydrocarbon, the copolymer does not have any free amine groups, and accordingly has an acid number of zero. However, when prepared from diacid, diamine and hydrocarbon- terminated polyether, some of the diamine may not react with the diacid and/or polyether, and accordingly the final product may have some unreacted amine groups that will be responsible for the final product having an amine number greater than zero. Preferably, the product has a minor amount of this unreacted diamine, and thus only a small amine number. Amidification catalysts may be used to encourage all of the diamine to react with carboxyl groups, so as to minimise the amount of free amine.

Optionally, the polyamide-based thickener is a polyalkyleneoxy-terminated polyamide thickener having a weight average molecular weight of 15,000 to 25,000, and a softening point of 75°C to 125°C. Preferably, the polyamide-based thickener is a polyalkyleneoxy- terminated polyamide thickener having a weight average molecular weight of 18,500 to 20,000, and a softening point of 80°C to 100°C. Thickeners having these properties were found to produce gels with particularly good properties with comparatively low sensitivity to the other components and pH of the gel. A particularly preferred polyalkyleneoxy- terminated polyamide thickener is Crystasense HP5, marketed by Croda.

Carrier compositions

Preferably, the gel is an aqueous gel (that is, a gel containing water). In other words, the carrier composition is an aqueous composition (e.g. aqueous solution), such that the gel contains water as a solvent. Advantageously, this can allow a range of water-soluble ingredients to be held within the gels.

The water content of the gel composition is greater than 50 wt.%, preferably greater than 60 wt.%, greater than 70 wt.%, or greater than 80 wt.%, the weight percentage being as a percentage of the total weight of the gel composition. The upper limit for water content is 85 wt.%, in view of the lower limit of 15 wt.% for the thickener.

Suitably, the water is dispersed within the gelled polyamide-based thickener. This is in contrast to the situation where an alternative solvent is dispersed in the gelled thickener, and the gel is subsequently diluted in water to form an emulsion of gel in water.

The gel composition may comprise solvents other than water, e.g. it may comprise polar solvents more generally. Optionally, water is the only solvent in the gel composition.

Active ingredients

Suitably, the gel composition includes an active ingredient. The active ingredient is a constituent which imparts a specific activity to the gel composition which makes the gel suited to a particular application. The active ingredient achieves an effect beyond formation of the gel itself, and may be deliverable from the gel to achieve that effect.

The active ingredient may be a homecare active ingredient or a personal care active ingredient. The active ingredient may be one or more actives selected from a cleaning active, care active, cosmetic active, fragrance active, or a corrosive active.

The active ingredient may be a cleaning active, such as a surface cleaning active (e.g. hard surface cleaning active), a fabric cleaning active, a body cleaning active, or a makeup removal active. The active ingredient may be a care active, such as a conditioning active (e.g. a fabric conditioning active), a softening active, a skincare active (e.g. moisturiser or sunscreen), a medical active, an anti-corrosion active, or a polish active. The active ingredient may be a cosmetic active, such as a make-up colorant.

The active ingredient may be a fragrance active, such as a perfume.

The active ingredient may be a corrosive active, such as a paint stripper.

Surfactant

Suitable cleaning actives include surfactants.

The surfactant may be present in an amount of 50 wt.% or less, 40 wt.% or less, 30 wt.% or less, 20 wt.% or less, or 10 wt.% or less. The surfactant may be present in an amount of 0.001 wt.% or more, 0.01 wt.% or more, 0.05 wt.% or more, or 0.1 wt.% or more.

Preferably, the surfactant is present in an amount of 0.01 to 10 wt.% of the composition.

In particular, the surfactant can increase the viscosity of the gel compositions, and compositions incorporating 0.01 to 10 wt.% surfactant and at least 15 wt.% of the polyamide-based thickener can have good mechanical properties and be capable of attaching to surfaces. For the avoidance of doubt, the above ranges refer to the total amount of surfactant in the gel composition.

The surfactant may be selected form the group consisting of anionic, non-ionic, cationic, amphoteric/zwitterionic surfactants and mixtures thereof.

Preferably, the surfactant is or includes a non-ionic surfactant, or mixture of non-ionic surfactants. Nonionic surfactants include primary and secondary alcohol ethoxylates, especially Cs- C20 aliphatic alcohol ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and more especially the C10-C15 primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to 10 moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionic surfactants include alkyi polyglycosides, glycerol monoethers and polyhydroxy amides (glucamide). For example, the nonionic surfactant may be alcohol ethoxylate, nonylphenol ethoxylate, alkylpolyglycoside,

alkyldimethylamineoxide, ethoxylated fatty acid monoethanolamide, fatty acid

monoethanolamide, polyhydroxy alkyi fatty acid amide, or N-acyl N-alkyl derivatives of glucosamine ("glucamides"). Mixtures of nonionic surfactant may be used.

Nonionic surfactants that may preferably be used include the primary and secondary alcohol ethoxylates, especially the C8-C20 aliphatic alcohols ethoxylated with an average of from 1 to 35 moles of ethylene oxide per mole of alcohol, and more especially the

C9-C15 primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to 10 moles of ethylene oxide per mole of alcohol.

Suitable anionic surfactants include alkyi sulphonates, such as alkylbenzene sulphonates, particularly linear alkylbenzene sulphonates having an alkyi chain length of Cs-C-is. The counter ion for anionic surfactants is generally an alkali metal, typically sodium, although other counter-ions for example MEA, TEA or ammonium can be used. Suitable linear alkyi benzene sulphonate surfactants include Detal LAS with an alkyi chain length of from 8 to 15, more preferably 12 to 14.

Other examples of suitable anionic surfactants include linear carbon chain sulfates, alcohol ether sulfates, alcohol sulfates, alkyi- and alkylaryl-alkyoxylated carboxylic acid, and the acid forms of these anionic surfactants. For example, the composition may comprise an alkyi polyethoxylate sulphate anionic surfactant of the formula: where R is an alkyi chain having from 10 to 22 carbon atoms, saturated or unsaturated, M is a cation which makes the compound water-soluble, especially an alkali metal, ammonium or substituted ammonium cation, and x averages from 1 to 15. Preferably R is an alkyi chain having from 12 to 16 carbon atoms, M is sodium and x averages from 1 to 3, preferably x is 3; This is the anionic surfactant sodium lauryl ether sulphate (SLES). It is the sodium salt of lauryl ether sulphonic acid in which the predominantly C12 lauryl alkyl group has been ethoxylated with an average of 3 moles of ethylene oxide per mole.

Suitable cationic surfactants include quaternary ammonium salts having the formula:

R a R b R c R d N + X " where R a , R b , R c , and R d are each C1-24 alkyl, aryl or aralkyl groups, and X is a suitable counterion such as F, CI, Br, I or an alkyl sulfate.

Suitable zwitterionic surfactants include, for example, betaines, sultaines and glycines. QH

Advantageously, the formation of the gel compositions of the present invention may be relatively insensitive to pH. Therefore, the pH of the gel composition is chosen depending on the other ingredients of the composition, and the intended application. The pH may be at least 0.1 , at least 0.5, at least 1 , at least 2, at least 3, at least 4, or at least 5. The upper limit for the pH may be, for example, 13; 12; 1 1 ; 10; 9; or 8. For example, the pH may be in the range of about 2 to about 1 1 .

The pH may be adjusted using an acid pH adjuster such as citric acid, or an alkali pH adjuster such as sodium or potassium hydroxide.

Methods of producing the compositions

The present invention also relates to methods of producing gel compositions according to the first aspect of the invention, comprising adding a polyamide-based thickener as defined above to a carrier composition. The polyamide-based thickener is added so that it makes up at least 15 wt.% of the gel composition. Suitably, the carrier composition comprises the active ingredient.

Suitably, the method of production involves melting the polyamide-based thickener (by heating to above the thickener's softening point), and adding the molten thickener to a carrier composition. Optionally, the carrier composition is heated prior to addition of the molten thickener, and the thickened carrier composition is cooled to form a gel. For example, the carrier composition may be heated to a temperature within 50°C/40°C/30°C of the softening point of the thickener but below the boiling point of the carrier

composition. Suitable temperatures may be, for example, between 50°C to 100°C; 60°C to 100°C; or 70°C to 100°C.

The method may involve the additional step of forming the carrier composition. For example, a carrier composition may be obtained by heating a solvent (e.g. water), and adding said active ingredient and other formulation ingredients to the solvent under stirring.

In the above method, the polyamide-based thickener is preferably a polyalkyleneoxy- terminated polyamide thickener. The polyalkyleneoxy-terminated polyamide thickener preferably has a weight average molecular weight of 15,000 to 25,000, a softening point of 75°C to 125°C, and optionally one or more of: an acid number of less than 20 and an amine number of less than 5. Most preferably, the polyalkyleneoxy-terminated polyamide thickener has a weight average molecular weight of 18,500 to 20,000, a softening point of 80°C to 100°C, and optionally one or more of: an acid number of less than 15 and an amine number of less than 3. As noted above, the inventors have found that thickeners having these properties produce gels having particularly beneficial physical properties, including the ability to attach to a surface. A particularly preferred polyalkyleneoxy- terminated polyamide thickener is Crystasense HP5, marketed by Croda.

Product forms

The gel composition may be in the form of a ball or tablet. For example, the gel composition may be a ball of a surface cleaning composition which can be spread onto a cloth, or a tablet of cosmetic material which can be spread directly onto the skin.

The gel composition may be in the form of a unit dose, containing a pre-determined amount of said active ingredient.

The gel composition may be in the form of unit dose provided on a substrate. For example, the gel composition may be a film on a substrate. The film may have a thickness of, for example, 0.25 mm or more, 0.5 mm or more, 0.75 mm or more, 1 mm or more, 1 .5 mm or more, 2 mm or more, 3 mm or more, 4 mm or more, 5 mm or more, 7.5 mm or more, 10 mm or more, or 20 mm or more. A further aspect of the present invention provides a homecare product comprising a gel composition according to the first aspect. The homecare product may be, for example, a cleaning gel tablet or bolus for spreading on a surface, comprising a gel composition according to the first aspect. A further aspect of the present invention provides a personal care product comprising a gel composition according to the first aspect.

A further aspect of the present invention provides an aqueous gel composition comprising at least 15 wt.% of a polyamide-based thickener. This composition may have any of the preferred and optional features discussed in relation to the gel composition of the first aspect.

EXAMPLES

Experiments were carried out to demonstrate the advantageous characteristics of the gel compositions of the present invention.

Several gel samples were prepared by adding a commercially available polyamide-based thickener (Crystasense HP5, from Croda - a polymer having a M w -19,000, softening point of 93°C, acid number of less than 15 and amine number of less than 3) to water- based carrier compositions. Details of these compositions are given in Table 1 below. The gel compositions were formed by:

1. melting pastilles of the thickener at 95°C;

2. heating the water to 70°C;

3. adding the carrier composition components to the water and stirring for 1-2

minutes at 150-300 rpm using a Heidolph RZR 1 overhead stirrer, until uniformly dispersed;

4. slowly adding the molten thickener to the carrier composition and stirring for 5 minutes until fully dispersed and uniform; and cooling the composition to produce a solid

Table 1 - Sample compositions (amount values given in wt.%)

( b) Neodol 91 -8 (Shell), which corresponds to ethoxylated C9-11 alcohols having -69-7% EO groups, EO/OH 8.3, M w of 524 and HLB of 13.9.

(c) Dehyquart A-CA, which corresponds to cetrimonium chloride.

(d) pH was adjusted using citric acid or sodium hydroxide. The behaviour of each sample under applied force was evaluated, to assess whether the formulations could be worked and spread, without crumbling. To carry out this test, a 5 cm wide steel spatula was manually pushed down on a 50 g quantity of each sample. A sample was deemed acceptable if the force being applied resulted in the gel spreading uniformly. If the sample broke into smaller particles or resisted spreading to the point of requiring a lot of force, it was deemed unsuitable.

The hardness was scored 1 -10 based on perceived force to breakdown the sample.

1 = too low. This meant very little force was required and the structure broke down too easily.

5 = medium. This meant a reasonable amount of force was required but the sample did not resist too much.

10 = too high. This meant a lot of force was required, to the extent we felt it was too much. Table 2 - Composition spreading data

The data in Table 2 demonstrate that compositions of the present invention are capable of forming hard, dry unit doses suitable for easy handling by a consumer, which can be smoothly spread onto a surface.