GB2336848A

GB2336848A - Liquids release from particulate surface cleaners

Info

Publication number: GB2336848A
Application number: GB9809264A
Authority: GB
Inventors: Mark Phillip Houghton; Gerard James Delay
Original assignee: Robert McBride Ltd
Current assignee: Robert McBride Ltd
Priority date: 1998-04-30
Filing date: 1998-04-30
Publication date: 1999-11-03
Also published as: GB9809264D0

Abstract

Particulate compositions primarily suitable for the domestic cleaning of carpets and upholstery are disclosed in which encapsulated liquids may be selectively retained on the item to be cleaned by means of selecting the particle size of the encapsulate and the ratio of encapsulate to carrier particle size. The cleaning agent is intended for use without a solvent medium, with excess cleaning agent being removed at the end of the cleaning process by vacuum cleaner. This enables perfumes, bactericides and similar liquid materials to be retained on the item being cleaned whilst the cleaning agent removes other liquid soil components such as greases and oils.

Description

1 2336848 LIQUIDS RELEASE FROM PARTICULATE SURFACE CLEANERS

FIELD OF THE 1NTION

The present invention relates to a high surface area particulate cleaning composition intended to clean high surface area objects, wherein the cleaning agent is not dissolved during the process. The cleaning agent is partially removed at the end of the process by suction such that a liquid component is left partially in situ by means of an encapsulate.

BACKGROUND TO THE RWENTION

Detergent compositions are known in many physical forms including powders, liquids, pastes and tablets. Most compositions rely on dissolution of the composition to a working concentration with a suitable solvent, for example, water. Another class of cleaning agents are designed to be spread as solids on the article to be cleaned. By virtue of their contacting soil components on the article they adsorb some of the soil. On subsequent removal by vacuuming a proportion of the soil is therefore removed with the cleaning agent. This type of product is particularly suitable for household cleaning of carpets, upholstery and curtains where the use of water or solvents is impractical. The process primarily acts to freshen the articles, the action of perfiame is therefore central to the perceived efficacy of the product.

In formulating such products with perfume the technologist faces a dilemma. First that a particulate composition must be capable of adsorbing oily soils from articles to be cleaned, for example by capillary action. Yet it must distribute perfume adsorbed in the particulate composition to the article, which is the reverse process. Only if this is achieved is any persistence of the fragrance observed. This is particularly important with deodorising fl-agrances. With current products the perfume is largely left in the particulate composition and what is transferred to the article to be cleaned is largely removed in the vacuum cleaning step. A proposed solution is to utilise micro encapsulated fragrance of such a particle size and composition as to enable it to be retained on the article to be cleaned after the vacuuming process.

It is therefore desirable to have a method of successfully formulating a particulate cleaning composition to be used without dissolution whereby perfume is transferred to the article to be cleaned to enable a persistence of the fragrance so as to maintain the perceived cleanliness of the article and/or any deodorising benefit.

It is an object of the present invention to obviate or mitigate the abovementioned disadvantages.

2 BACKGROUND AR-T

Solid cleaning compositions for use, for example, on carpets have been known for many years. US 2, 165, 586 (Studer) discloses a carpet cleaning composition based on buckwheat flour which is spread over the carpet, rubbed in and then removed using a vacuum cleaner. Micro encapsulated fiagrance treated fabric has been disclosed in US 4 882 220 (Kanebo Ltd). This discloses the use of a resinous binder by which the encapsulates are bound to fibres from the medium of a liquid composition. A large range of encapsulating systems are available and a range of examples are cited in US 4,520,142 (Minnesota mining Co.) which describes the use of encapsulates in aerosol applications.

Encapsulates in combination with a powdered carpet cleaner have been disclosed in the text of US 4,244,834 (Borax Corp). No examples are cited and indication is given as to how they are to be used so that the encapsulate may be preferentially deposited on the items to be cleaned whilst not being removed in the vacuuming step. In addition it discloses a preferential use with antistatic agents which based on comparative results herein described reduce the retention of encapsulate. No disclosure of non odiferous encapsulated materials is made.

None of the art teaches a practicable method of formulating an encapsulated liquid or perfume such that the encapsulate is preferentially retained on the article to be cleaned such that the encapsulated material may be released subsequent to the cleaning process.

SUMMARY OF = INVENTION

The present invention provides a cleaning composition consisting of a carrier powder of average particle size between 100 gm and 1000 ptm in combination with an encapsulate such that the encapsulate has an average primary particle size of between 1 0Optm and 0.01 gm. The encapsulated material may be one of a perfinne, bactericide, insect repellent or a combination thereof. This encapsulate will be of any effective level but more preferably levels of 0.02 to 5% will be used.

DETAILED DESCRIPTION OF THE INVENTION

Thus according to the present invention the cleaning composition is a free flowing powder base composition to which is admixed an encapsulated liquid composition.

The PQwder base cQmposition The powder base composition will typically comprise high surface area particles often of a porous nature. These particulate materials may, for example, be a alkaline earth metal carbonate, clay, alkali metal polyphosphate, an alkali metal carbonate, alkali metal 3 bicarbonate, alkali metal citrate, zeolite or a crystalline or amorphous silicate. Zeolites 4A and A24 are examples. Mixtures of these materials may be used.

The clay may for example be a smectite such as a Laponite, Bentonite, Montmorrillonite, Hectorite or Saponite. For example, the clay may be a Sodium Montmorrillonite, a Sodium Hectorite, a Sodium Saponite, a Calcium Montmorrillonite or a Lithium Hectorite. The particulate mixture may in addition contain dyes, pigments or other coulorants. For practical purposes the materials may be as derived from natural sources, for example, limestones and chalks and may therefore contain levels of impurities associated with these sources, for example quartz.

The particulate mixture will typically comprise from 95% to 99.98% of the composition.

Additional components adsorbed on the base composition A cationic surface active agent may also be employed as a part of a base composition for example as an anti-static agent but is not a preferred embodiment of the invention. The cationic surface active agent is preferably used in an amount of up to 2%, more preferably up to 1 %, even more preferably up to 0.5% by weight of the formulation. Examples of suitable cationic surface active agents include quaternary ammonium salts having three lower (C,-j alkyl groups (preferably methyl groups) and a long chain (C&_20) alkyl group, e.g. coco trimethyl ammonium chloride. Further examples include alkyl pyridinium salts and other compounds in which the nitrogen atom of the pyridine assumes a quaternary form, e.g. as in an alkyl pyridinium bromide. Further examples of cationic surface active agents which may be used include amine and imidazoline salts.

The encapsulate The encapsulating material may be any material which gives a particulate encapsulate where no part of the encapsulated liquid can directly contact its surroundings. Liquids adsorbed in porous or permeable materials are therefore not included. It is recognised that in commercial production some encapsulate material will inevitably remain un-encapsulated and some coating remain unused. This invention does not therefore rely on the success of the encapsulation procedure or of the amount or proportion of any liquid or liquids present that have been encapsulated but on the presence of encapsulated material per se.

Suitable encapsulating materials are illustrated by the following nonlimiting examples:

Organic polymers - Addition polymers - eg Poly Vinyl; ethers, esters, amides, carboxylates, maleates, methacrylates, acrylates, alcohols, acetates and copolymers thereof.

4 - Condensation polymers - eg Poly; esters, and urethanes, gelatin, xanthan gums, guar gum, alginates.

I- The encapsulates will typically consist of largely spherical structures filled at lest in part with the desired liquid, the remainder being either liquid vapour, air, nitrogen, argon or similar. These structures may consist of aggregates of multiples of these primary structures as may typically be produced during the encapsulation process.

The encapsulates may typically be produced by emulsifying the desired liquid in another liquid, the introduction of an amphiphillic polymer or monomer which will reside largely at the interface of the droplets. This emulsion or suspension is then reacted to polymerise and / or cross link to form suspended encapsulate which is then used as such or removed by filtration, centrifugation or other suitable means.

The Encapsulated material In addition an encapsulate or a liquid may be incorporated in the composition for the purposes of substantially segregating a liquid component from the other components of the composition when in a tablet form. As used herein the term encapsulate refers to a particulate material in which comprises a liquid or substantially liquid phase or phases surrounded completely by a barrier or membrane which is impermeable to the said liquid phase material(s).

The encapsulated liquid may be any liquid with a detergent function examples being Perfumes and Odiferous substances Perfume precursors (eg. esters of volatile aldehydes and ketones) Bactericides Bactericidal fragrances Examples of suitable are given in 'Antimicrobial activity of Aroma Chemicals and Essential oils, Morris, Khettry, Seitz; Journal of the American oil chemists society, Vol 56, No 5, pp 595-603, 1979.

EXAMPLES

The invention will be further described with reference to the following non-limiting examples.

EXAMPLES 1

Performance in various base compQ.ition-s Table 1: Comparative-compositions Composition 1 2 3 4 5 6 7 Porous Silica 1.2 1.2 2.4 1.2 1 2 Calcium 97.6 98.8 95.2 Carbonate Sodium so 30 Carbonate Sodium 47.8 47.8 Bicarbonate Sodium 20 Triphosphate Zeolite 98 96 Perfume 1.2 NIL 2.4 1 1 1 2 Porous Silica = Microsil ED ex Crossfield Calcium Carbonate Trucarb 130 ex Tilcon Sodium Carbonate Granular Ash ex Brunner Mond Sodium Bicarbonate = Sodium carbonate ex Brunner Mond Sodium Triphosphate = STP P ex Albright and Wilson Zeolite = Zeolite 4A ex Degussa Perfume = EFF 71012 Alpine Meadow ex European Fragrances

6 Table 2: Compositions Composition AA B c D E F G H Porous Silica 1.2 2.4 2.4 1.2 1 2 1 Calcium 96.6 93.2 93.2 96 Carbonate Sodium 50 30 Carbonate Sodium 46.8 47.8 Bicarbonate Sodium 20 Triphosphate Zeolite 97 95 Perfume 1.0 2.0 2.0 1.0 1.0 1.0 1.0 1 encapsulate C Perfume 1.2 2.4 Nil 1 1 1 2 1.2 Cetyl 1 trimethyl Ammonium Chloride The Perfume encapsulate used in AA contains Perfume at 50% activity. Average particle size 1Ogm. Based on Gelatine polymer. Average particle sizes composition AA = 350gm, composition E = 520gm.

7 The compositions were sprinkled on a wool carpet tile (5mm thick pile) at a rate of 0.5g per square centimetre. The tiles were then left for fifteen minutes and the excess powder removed with a vacuum cleaner. The assessment was carried out by five people using the following sconng system. 5 = Strong fragrance 4 = Fragrance clearly present 3 = Fragrance present 2 = Fragrance present but weak 1 =Fragrance just perceivable 0 = No Fragrance Table 3: Test 1 results Composition AA B c D E F G Initial smell 5 5 1.2 5 5 5 5 Composition 1 2 3 4 5 6 7 Initial smell 5 0 5 5 5 5 5 Table 4: Test 2 results Increase in tile weight per square centimetre (Final tile weight - Initial tile weight) Composition AA B c D E F G Initial smell 0.05g 0.04g 0.08g 0.02g 0.02g 0.20g 0.21g Composition 1 2 3 4 5 6 7 Initial smell 0.06g 0.03g 0.07g 0.01g 0.02g 0.21g 0.23g This demonstrates that the cleaning composition has been substantially removed by the vacuum cleaning process.

The carpet tiles were then left in a ventilated area at room temperature for 5 days and reassessed.

Table 5: Test 3 results Composition AA B c D E F G Initial smell 0.2 0.4 0 0 0 0 0.8 Composition 1 2 3 4 5 6 7 Initial smell 0 0 0.4 0 0 0 0.4 8 The tiles then had a clean steel 1 Okg weight dropped on them from a height of 0. 5m five times to simulate walking on a carpet.

Table 6: Test 4 results Composition A B c D E F G Initial smell 3 4 4 3 3 3 4.2 Composition 1 2 3 4 5 6 7 Initial smell 0 0.4 0 0 0 0 0.4 These results demonstrate the ability to deposit the encapsulate of 1 Ogm diameter on a surface without removing its effect whilst substantially removing the carrier 'base' composition.

The effect Qf Encapsulate 12artiele size The following composition were made according to Composition AA above but in the other cases the encapsulate size was varied as in the table below. The test regimes indicated above for Tests 1,2,3 and 4 were used.

Table 7

Composition Average Result Encapsulate Test 1 Test 2 Test 3 Test 4 Diameter AB 2im 5 0.05g 0.4 3.6 AA 1 Ogm 5 0.05g 0.2 4.0 AC 15gm 5 0.06g 0.2 3.8 AD 20pim 5 0.10g 0.4 2.8 AE 50pt 5 0.05g 0.2 1.2 AF loogm 5 0.05g 0.8 0 AG 230gm 5 0.02g 0 0 H 10PLM 5 0. 1 Og 0.2 2.8 1 Nil 5 0.06 0 0 Nil 5 0.07 0.4 0.4 9 This demonstrates that there is an optimum size for the encapsulate and that there is no advantage of including a cationic anti-static agent.

Examples- including an antibacterial perfume compQnent Example AA-ABP 1 as example AA but with the inclusion of 10% by weight para tert butyl meta cresol. Ex Aldrich chemical Co. Example AA-ABP2 as example AA but with the inclusion of 0.4% by weight Undecyl aldehyde. Ex Aldrich chemical Co.

Table 8

Compostion Average Result Encapsulate Test 1 Test 2 Test 3 Test 4 Diameter AA-ABM 11 PLM 5 0.05g 1 5 AA-ABP2 14gm 5 0.05g 0.2 4.2 AA 1 Ogm 5 0.05g 0.2 4.0 1 Nil 5 0.06 0 0 3 Nil 5 0.07 0.4 0.4 Exm-121es- Ii ing a t" perfwne combinatiQn Example AA-2perf as example AA but with the unencapsulated perfwne being Spring Soft LR 54106 ex Bush Boak Allan and the encapsulated perfume being 79951 Summer Blossom ex European Flavours and Fragrances.

Table 9

Composition Average Result Encapsulate Test 1 Test 3 Test 4 Diameter /Smell AA-2 11 PIM 5 5 Bright Background Floral aldehydic smell summer Spring notes notes This shows a composition where there is a sequential release of fragrance type.

Claims

1) A powder composition for cleaning in the absence of a continuous liquid phase consisting of a carrier powder of average particle size between 100 tm and 1000 vim in combination with encapsulated liquid such that encapsulated materials have an average primary particle size of between 100 gm and 0. 0 1 ptm.

2) A composition according to claim 1 where the ratio of the average particle sizes of the encapsulated materials to the rest of the composition is 1: 10.

3) A composition according to claim 1 where the ratio of the average particle sizes of the encapsulated materials to the rest of the composition is 1:20.

4) A composition according to claim 2 or 3 where the encapsulated materials have an average primary particle size between 2gm and 20gm.

5) A composition according to claims 4 where encapsulated materials are present at between 0.02 to 5% by weight.

6) A composition according to claims 3, 4 or 5 where the encapsulating material or materials are organic polymers.

7) A composition according to claim 4 where the encapsulated material or materials are one or more of a perflune, bactericide, bactericidal perfume, insect repellent or a combination thereof 8) A composition according to any proceeding claim wherein two fragrance materials are chosen such as to give a sequence of hedonic characteristics by using one as a free fragrance and the other as an encapsulated material.

9) A composition according to claim 5 or 6 where the composition is contains greater than 90% water insoluble material and which is substantially free of surface active material.

10) A composition according to claim 6 where the encapsulating material is gelatine and the composition contains greater than 90% calcium carbonate.

11) A composition according to claim 7 where the encapsulated material is a bactericidal perfume or insect repellant.

12) A method of cleaning carpets and upholstery consisting of spreading a particulate mixture 11 according to claim 7, removing the excess by vacuum cleaner such that residual perfume may be detected after 1 week by the application of a compressive force to the fabric so treated.