CA2155977A1 - Cleaning - Google Patents

Abstract

An aqueous based cleaning composition, e.g. for textiles, comprises in addition to a major part of water, a surface active agent, a base and an organic acid, or a salt of a base and an organic acid, and a dispersed phase of a hydrocarbon. The hydrocarbon is preferably a terpene, most preferably limonene. The composition may be used for cleaning textile articles in a process which involves directing ultrasonic waves at the articles to be cleaned.

Description

WO ~118300 2 J 5S~ 7 7 ~IGB94/00287 , ~

CLEANING
This invention relates to cle~ning. The invention provides a , composition for use in cle~ning, a process for the preparation of the composition and a method of cleAnin~.
Textile materials, for example garments or curtains, are often cleaned using a well-known process of "dry cleAning!'. In dry cle~nin~, an article to be cleaned lS immersed in a cleAni ne fluid and agitated to dislodge particles of d1rt and grease. The cleaning fluid aids remo-~ral of the dirt and grease from the article and subsequently aids dispersion and sequestration of the dirt and grease in Ihe cleaning fluid.
Some probiems with dry cleaning are associated with the clean1ng fluids used. The most widely used cle~ning fluids are highly fl~mmAble hydrocarbons and chlorinated hydrocarbons, particularly tetrachloroethene. The use of sùch highly inf1~mmAble soivents, which .
also have low flash points, presents a significant fire risk and, accordingly, the solvents must be handled very carefully under strictly controlled conditions. Also, the use of the solvents presents an environmental hazard and a health risk to personnel, since they are often carc1nogenic. Furthermore, the solvents are highly volatile and may be absorbed through the skin o, inhaled. Thus, it wouid be preferable to use a less problematic solvent in cleaning.
It is an ob]ec~ of the present invention to alleviate at least some of the aforementioned problems.

According to a first aspect of the present invention there is provided an aqueous based cleaning composition comprising, in addition to a major part of water, a surface active agent, a base and PCrIGB~410~7 215597-7i ~

an organic acid, or a salt of a base and an organic acid, and a dispersed phase of a hydrocarbon.
According to a second aspect of the present invention, there is provided a process for the preparation of the cleP~nin~ composition J
of the first aspect, the process comprising ;~lmi~rin~ a major ~o~o~Lion of water with minor proportions of a surface active agent, a base and an organic acid, or a salt of a base and an organic acid, and a hydrocarbon.
It has been found that the cleaning composition is effective for removing dirt and grease from many articles, for example, from te~ctile materials. The composition is particularlv advantageous in comparison ~o the solvents used in dry cleaning desc, ibed above since a major portion of the composition is water and only a minor portion is comprised by potentlally fl ~mm~ble a~dior toxic hydrocarbon. Thus, the composition may be more environmentaliy and to~icologically acceptable comparec to the known dry cle~nina solvents. The cieaning composition is also effective for cleaning non-textile materiais, for example work surfaces made of wood or plastics material. Other uses of the cleAning~composition are in metal degreasing and wool scouring.
The preferred hydrocarbons for use 1n the cle~nin~ composition of the invention are terpenes which are built up of isoprene (CL H8) units. Terpenes are rl~csified into open chain, monocyclic, bicyclic, , : .
sesqui and polyterpenes and any such form of terpene may be used in the composition OI the invention. Most preferably the terpene is limonene which has the chemical name 4-isopropenyi-1-methylcyclohexene (CloHl6)~ Limonene may be provided by D'limonene which is of citrus origin. D'Limonene generally contains at least 95%
4-isopropenyl-1-methylcyclohexene. ~nother name for D'Limonene is ~/18300 2 PCrlGB~94/~287 stripper oil (see also Food Chemicals Codex, 1981). D'Limonene is mostIy composed of ~mono Terpene Hydrocarbons.
Synonyms for D'Limonene incIude (+)-Carvene, Citrene, Limonene, 1,8-p-Menth~Aiene. The preferred source of D'T.imon~ne is Br5-7iliAn Other terpene hydrocarbons derived form the essential oils extracted from the leaves, blossomc~ fruits and barks belonging to the family Coniferae and Myrtaceae and the genus Citrus may also be used in place of D'Limonene. The essential oils c omprise mixtures of Terpenes which havè the empirical formula (C5H~3)n and oxidation products of these.
Other hydrocarbons which may be used in compositions of the invention include carrotenes, pine oil, white spirit; paraffin (kerosene), iso-paraffins, and petroleum distillates. These products may also be in the form of their odourless alternatives.
White spirit (C.A-.S. No. 80~2-41-3) includes a mixture of saturated and unsaturated hydrocarbons and, optionally, aromatic hydrocarbons and the invention covers the constituents of the mixture singularly or in combination. Where the white spirit includes aromatic hydrocarbons, préferably it co,l,~,ises 15-20~6 of aromatic hydrocarbons.
Aromatic hydrocarbons include C6 -C 12 aromatics. Preferred aromatic hydrocarbons include C7 (toluene), C8 and Cg aromatic hydrocarbons.
Turpentine lS also a mixture of hydrocarbons, for example cyclic terpene hy~irocarbons, primarily a-pinene and the invention of the first aspect covers the` constituents of the mixture singularly or in combin~f iorl It should also be understood that he term 'hydrocarbon' as used herein is also intended to cover substituted hydrocarbons, e.g.
halogenated hydrocarbons such as chlorinated hydrocarbons.

W~14/~ i59 l ~ PCrlGB941W~7 J

~ The amount of hydrocarbon present in the composition is preferably less than 10%, more preferably less than 3% by weight of the total we~ght thereof. Even more preferably the amount of hydrocarbon is less than 39b ~and ideally less than 2~ on the same weight basis.
The composition ~further COIllyf ises an organic acid and a base, or a salt of these two components. The organic acid should be a weak acid. Most preferably the organic acid is a water soluble carboxylic acid, ideally one having b or less carbon atoms. It is also preferred that the organic acid is a monocarboxylic acid. Thus preferred acids include formic acid, propionic acid, butyric acid, valeric acid, and caproic acid. The most preferred acid for use in the composition is ;A1 acetic acid although other commercial grades commonly known as ethanoic acid, technical grade, vinegar acid may also be used. It is however possible to use higher functionality acids, e.g. citric acid.
If free acid is included in the composition then it is preferably incorporated therein in an amount of less than 10%, more preferably less than 5%, and most preferably less than 2~%, by weight of the total weight of the composition.
The base is preferably ammonia used in the form of an aqueous solution (e.g. products known as ammonia solution, aqueous ammonia, ammonia liquor, and ammonium hydroxide. Preferred ammonia solutions are these known as '880 ammonia' having an ammonia content of 33-! 34%. The ammonia solution should be a clear, colourless solution freefrom suspended matter and residual deposits.
Bases other than ammonia may also be used, e.g. alkali metal hydroxides such as sodium or potassium hydroxide. Other bases which may be used include alkanol~mines.

The amount of base used is preferably less than l0g6, more wo94nuoo ~ ~tSS37~ I'CT/G11!~4/1102X7 preferably less than 5% by weight of the co"l~osition, most preferably less ~than 296 by weight. Any amount of base ~relative to acid may be used.
lt is also possible to incorporate in the composition a salt of a base and ~ an organic acid. In this case the salt will generally be added instead of the free acid and base, but may be added as a supplement thereto. Preferred salts are those derived from any of the afo~e~ tioned bases and organic acids. Most preferred are the or-ium salts of organic carboxylic acids, e.g. ammonium acetate.
The salt, if used, is preferably added in an amount of less than 1096, more preferably less than 596i e.g. less than 2%.
The actual acid/base combination or salt used in the composition may be governed by the end use thereof. Thus if the composition for use is cleaning textile materials then the acid is preferably acetic acid ~and the base is preferably ammonia. Alternatively ammonium acetate may be used as salt. For cleaning of leather it is preferred that the acid is formic acid and the base is ammonia. Alternatively ammonium formate may be used as a salt.
Water from any source may be used in the compasition. It is, however, preferred to use soft water or distilled water. The recornmended water type is distilled, although this may be replaced with de-inn;se~l or waters up to a~ Hardness of 30ppm calcium as ~lcillm carbonate. Generally the amount of water present will not be less than 60%, more usually not less than 70% by weight.
The detergent is adapted to disperse the hydrocarbon-cont~ining solvent in $he water. Any anionic and/or a non-ionic surfactant may be used. The detergent is preferably biodegradable. The detergent suitably comprises a ~long chain ~e.g. C8-Cl63 sulphonic acid (or salt WO ~14/18300 ~5~9~rl PCIIGB94/00287 thereof), for eYA~I~rle a long chain alkyl ~ "~e sulphonate such as dodecyl be~ ~ene sulphonate which may be in co~binAtion with a fatty alkyl~mi-l~, Other surfactants inrlurle olefin sulphQr~tes and paraffin sulphorl~t~. ~he amount of surface active agent in the composition is preferably less than 10%, more preferablyi less than 5%, e.g. less t han 2 %.
The surfactant may be added as formlllAtion which contains components other than the surfactants e.g. water and terpene. The surfactant formulation may for example contain at least one surface active agent together with a monoethanolamine. a glycol ether, D'limonene, andjor water. One such form~llAtion (referred to in Example 1 below- as surfactant Fo~mulation A) comprises the following co...~onent8.

PREFERRED % WEIGHT
'T im~nene 18.50 Water 52.00 MonoethAnolAmine (MEA) 3.00 DodecyllJe~ su~phonic acid ~DBSA)16.50 Butyl diglycol ether (8DE) 10.00 ~, .
If such a surfactant formulation, the D'limonene may exist as an ;on in the water, the ~ml~lcified phase having a droplet size of 1 micron or less.
The D'~ i. o ~ é ` ~e,-t in this 'surfactant~ f~rmulation' may provide `part of the total D'limonene for the cG~.~Gs~tion of the invention.
~ he l~lo..oethAnolAmine in the a'oove formulation is preferred but ~_, W0~ PCT/GB94100287 7 ;.~
may be rerl~e~ by any ~lk~nols~mine. The butyl diglycol ether may be repl~ce~ with any suitably commercially available glycol ether such as diethylene glycol Illonolllethyl ether, d;ethylene glycol monobutyl ether, and ethylene glycol monoethyl ether.
Additionally, the 'surfactant formulation' may contain any one or combinations of the following components either in addition to or as at least a partial repl~c~ment for the MEA, DBSA and/or BGE, namely lauryl-myristyl ethoxylates, cetyl-stearyl ethoxylates, cetyl-oleyl alcohol ethoxylates, fatty alcohol ethoxylates, oxo alcohol ethoxylates, branched oxo alcohol ethoxylates, isotridecyl alcohol ethoxylates, 2-ethylehA~nol ethoxylates, nonylphenol ethoxylates, octylphenol ethoxylates, low foaming,~biodegradable aIkoxylates, amine oxides, alkylol~mir~es, alcohol ethoxy sulphates, or castor oil ethoxylates or propoxyIates. However, the total amount of MEA, DBSA and BDGE
present in the formu~ation may be replaced by the same total amount of one or more compounds as listed in the previous sentence.
Formulations in accordance with the invention may contain a perfume or a reodourant, particularly if it is desired to suppress the aroma of the hydrocarbon. A reodourant wilI be particularly desirable in ~the case where the hydrocarbon is D'Limonene.
The~preferred reodourant is a complex blend of essential oils and aromatic plant extract compounded with synthetic aroma chemicals.
Preferably the pH of a cle~nin~ composition for use in f~1e:~ning textile articles is 5.5-6.~. It is however possible to use pH values outside this range, and this may be desirable for other cleaning appli~tione. Thus for example the pH may be greater than 7. The pH
may for example be greater than 9, e.g. in the range 9 to 12.
A preferred composition in accordance with the invention WO ~4/18300 ~; i. ~ `' . PCrIGJ~9V00~*7 ?.~5 8 CO~ ises Carboxylic Acid (e.g. acetic 1-2% by weight or formic) Base (e.g. sm~ ) 1-2% by weight Hydrocarbon 0.5-1.5% by weight Surface Active Agent 1-296 by weight Reo~lo~lrant 0.1-1% by weight Water Balance Generally tha amount of water will-not exceed 95.2~6.
The form~ t~ nc may be mixed together in any suitable apparatus for pro~lvci n~ the emulsified phase of the hydrocarbon, which will typically have a droplet size of 10-30 microns. It is preferred, but not essential, that the components are added to~ the water in the following order, namely acid, base, hydrocarbon, surface active agent, reodourant.
- Formulations of the type exemplified above may be supplied to the end use. It is however also possible for the end user to be supplied with various component of the formulation and to effect the final m~ n~ldilution as re~luired. Thus, for example, it is possible to produce a form~lAtioD comprising.

~Water 85g6 by weight Acid ~ j 5% by weight Base 5% by weight Surface Active Agent 5% by weight ~_, WO 941l8300 ~ S PCIIGB94/01l287 $9~

Such a form~ tinn may be diluted, by the end user, with 80% of water and then 1% by weight of hydrocarbon and re-odourant.
Dispersion of the hydrocar~on may take place in the apparatus in which the rleAning composition is used, e.g. laundry apparatus.
In addition to the co."p~,lents ~iccl~csed above, the composition may incl~le further components selected from the following.
1. Th;~kenin~ agents such as a xanthan polysAc~hAride compounded singly or with synthetic or natural thi ~ ke~ ers such as- cellulose ethers, locust bean gum, starches, ~ sodium alginate etc. Such thirkenin-~ agents would serve as an acid to reduce the effect of me~hAnical damage during use of the composition for wAchin~ textile articles.

2. An optical brightening agent.

3. ~ A cationic surfact:ant for p~rovidi~g softening fabric conditioning.

4. An amphoteric surface active agent for improved cleAning p~ rGl ,lumce.

5. Preservatives.

6. Glycerine.

7. Fat-liquoring agent ~for leather). ~

8. ~n amine for preventing corrosion when the composition is to be used for metal degreasing.
According to a third aspect of the present invention, there is provided a method of rleAnine an article, the methad comprising treating the article with a cleAning compQsition according to the first aspect of the invention.
The method may comprise immersing the article, for example, a textile article, in the cleaning~composition. The method of the third aspect of the invention as applied to the cleAnin~ of textile article ~ ~ 2 15 5 9 7 7 PCrIGB94101~7 has the cif~nifj~nt advantage over conventional w:~chin~e p~-Jc~Cs~c using wàter~ ~e.g. in conjunction with detergent) in that it is found that ~the te:ictile` articles dry ~ ci~erably more rapidly. Preferably agit~tion P~eans~ is provi~ed for aidi~g t~l~An;nf~
~ Accor~ing to a fourth ~aspect of the present -invention, there is provided a method of rle~nir~e a textile article, the~ method comprising arr~n~ine the-textile article in a container which contains a cleaning c~mposition in accordance with the first aspect of the invention and using ultrasonîc waves to clean said article in said container.~
Preferably,- ultrasonic waves are directed at the article in the container.
Preferably, the direction of travel of the ultrasonic waves is varied during said method of Cle5lninf~
The method of the fourth aspect of the invention may provide a method of rle~ninE which is improved over other known methods, in particular the dry cleaning method described above. For example, le:~nin~ is achieved without physically agitating the textile articles.
Such physical agitation may reduce detrimental effects on the shape andjor texture of the articles. The time that the article must spend in said container may ~e significantly less than in the dry cleaning method and, furthermore, the time that must be spent finichinf~ the rleAnetl ar~cle may also be reduced.
The~athod suitably uses a rle~nin~ apparatus (which provides s fifth aspect of the invention) which co,~ ising a treatment fluid container in which a textile article to be ~-le~ne~i may be immersed and ultrasonic cle~n;ne means arranged to direct ultrasonic waves suitably at said te~tile article when in said container, so as -to clean said textile article.

~, WO~83110 ~9 1~IGB94~7 The rl~nine apparatus may inrlllde holrlin~ means for a textile artide. Mov~u.ent means may be provided for moving a textile article held by said ho~ g means from a first position in which it is not S arranged within said container to a secor-~l position in which it is arranged with said container. Said holding means and/or said move.l.el.t means are preferably integral components of said apparatus.
The apparatus may include a plurality of said holding means and/or said movement means. Said plurality are preferably arranged to be selectively positioned adjacent said container so that a selected article to be cleaned may be arranged in said container. Said plurality of hol~lin~e means and/or movement means may be provided on a conveyor system. The conveyor system preferably comprises an en-ll~ss co.,v~yor.
.
The apparatus may include a- plurality of containers each cont~inin~ a ~leanine-composition. The method may include arr~neine the article to be cleaned in each container during ~said method of -leAnine. One of said containers may include a composition arranged to rinse the textile article. When provided, said holding means and/or said movement means are preferably adapted to arrange selectively the article to be cleaned in each container.
Filtration means may be provided for filtering the rleAning colrrocition in one or each container.
The apparatus may include heating means for heating the rlP~nine composition in said bath. Suitably, therefore, the method includes he~tine the cle~nine composition above ambient temperature , but preferably to less than 100C.
The invention is illustrated by the following non-limiting examples.

~WO 94/183110 ~ PCT/G1~9410~7 ~ , lZ

~Am~le 1 A ~le~ co. .l~osition was fortnl~lAte~ by AAmi~rine the following - cff~.L~ Pnt.-Component % by weil2ht Water ~ 95.2 Acetic Acid - 1.25 ~mm~r~iA ~ 1.05 D'T.i mnn~ne~ 0.98 Surfactant Formulation A 1.22 (see above) -Reodourant 0.30 This formulation is designated as 'Invention' in the Tables below.
,..
The composition was used in a converted Spencer dry-cleaning (Model 113) with overnight dlstillat1on (not used). The cage diameter was O.9l metres (3 feet). The following conditions were employed.

WAchin~ Time 6.5 minutes Drying Time 27 minutes Solvent Temperature 35-40C
Spin Time l minute Ambient Temperature 18-22C
Hot A1r in Starts at 40C 7 Hot Air out 33C
Cage Temperature Up to 108C Maximum ~, wo s4ns30~ PCT/GB94/00287 2lss977 The composition was tested on a light fawn 659~ polyester/35~6 viscose fabric which had various stains applied thereto. The results were co~r-red with those obt~ eA using perchloroethylene (standard dry-ele~nine solvent).
The results were as shown in the following Table. In the Table, the ~ieei~n~tion 'Totally' indicates that the stain was totally removed.
Simil~rly 'Partially' indicates partial removal, 'Trace' indicates a trace was removed, 'Almost Totally' indicates almost total ~ ~...oval of the stain, and 'Not' indicates that the stain was not removed.

Results Stain Invention Perchloroethylene Tomato Sauce Totally Not Feltip ~Black) Partially Partially Tipp-ex Partially Partially Red Marker Partially Trace Blue Ink Partially Not Mustard Totally ~iot Gravy Totally Not Beetroot Totally ~iot Curry - Totally Not Red Wine Totally ~ Totally It can be seen from the above that, for many stains, the cle~nine properties of the composltion of the invention were more effective than those of the perchloroethylene.

Claims (27)

1. An aqueous based cleaning composition comprising, in addition to a major part of water, a surface active agent, a base and a water soluble monobasic carboxylic acid, or a salt of a base and an organic acid, and a dispersed phase of a terpene.

2. A composition as claimed in claim 1 wherein the terpene comprises 4-isopropenyl-1-methylcyclohexene.

3. A composition as claimed in claim 2 wherein the terpene is provided by D'limonene.

4. A composition as claimed in any one of claims 1 to 3 wherein the terpene is present in an amount less than 5% by weight of the composition.

5. A composition as claimed in any one of claims 1 to 4 which include the monobasic carboxylic acid and the base.

6 A composition as claimed in claim 5 wherein the acid has 6 or less carbon atoms.

7. A composition as claimed in claim 6 wherein the acid is acetic acid or formic acid.

8. A composition as claimed in any one of claims 6 to 8 wherein the acid is present in the composition in an amount less than 5% by weight.

9. A composition as claimed in any one of claims 5 to 8 wherein the base is ammonia.

10. A composition as claimed in any one of claims 5 to 9 wherein the amount of the base is less than 5% by weight.

11. A composition as claimed in any one of claims 1 to 10 wherein the surface active agent comprises a long chain sulphonic acid or salt thereof.

12. A composition as claimed in claim 11 wherein the surface active agent comprises a dodecyl benzene sulphonate.

13. A composition as claimed in any one of claims 1 to 12 wherein the amount of surface active agent is less than 5% by weight.

14. A composition as claimed in claim 1 comprising a monocarboxylic acid having less than 6 carbon atoms in any amount less than 2%, a base in an amount less than 2%, a surface active agent in an amount less than 2%, a terpene in an amount less than 2%, optional incidental ingredients, and a balance of water.

15. A process for the preparation of the cleaning composition as claimed in claim 1, the process comprising admixing a major proportion of water with minor proportions of a surface active agent, a base and a water soluble monobasic carboxylic acid, or a salt of a base and an organic acid, and a hydrocarbon.

16. A method of cleaning an article comprising treating the article with a cleaning composition according to any one of claims 1 to 14.

17. A method as claimed in claim 16 wherein the article is a textile article.

18. A method as claimed in claim 17 wherein ultrasonic waves are directed at the textile article during the cleaning operation.

19. A method as claimed in claim 16 for cleaning leather.

20. A method as claimed in claim 16 for scouring wool.

21. A method as claimed in claim 16 for degreasing metal.

22. A method of cleaning a textile article, the method comprising arranging the textile article in a container which contains a cleaning compositions as claimed in any one of claims 1 to 14 and using ultrasonic waves to clean said article in said container.

23. A cleaning apparatus comprising a treatment fluid container in which a textile article to be cleaned may be immersed and ultrasonic cleaning means arranged to direct ultrasonic waves at said textile article when in said container.

24. Apparatus as claimed in claim 23 including holding means for a textile article.

25. Apparatus as claimed in claim 24 comprising movement means for moving a textile article held by said holding means first position in which it is not arranged within said container to a second position in which it is arranged within said container.

26. Apparatus as claimed in claim 24 or 25 including a plurality of holding means and/or movement means arranged to be selectively positioned adjacent said container so that a selected article to be cleaned may be arranged in said container.

27. Apparatus as claimed in claim 26 wherein said plurality of holding means and/or movement means are provided on a conveyor system, for example an endless conveyor.