Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/66—Non-ionic compounds
  • C11D1/72—Ethers of polyoxyalkylene glycols
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
  • C11D17/0008—Detergent materials or soaps characterised by their shape or physical properties aqueous liquid non soap compositions
  • C11D17/0017—Multi-phase liquid compositions
  • C11D17/0021—Aqueous microemulsions
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/16—Organic compounds
  • C11D3/18—Hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/16—Organic compounds
  • C11D3/20—Organic compounds containing oxygen
  • C11D3/2003—Alcohols; Phenols
  • C11D3/2006—Monohydric alcohols
  • C11D3/201—Monohydric alcohols linear
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/16—Organic compounds
  • C11D3/20—Organic compounds containing oxygen
  • C11D3/2068—Ethers
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/16—Organic compounds
  • C11D3/20—Organic compounds containing oxygen
  • C11D3/2093—Esters; Carbonates
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/43—Solvents

Definitions

• the present invention relates to surfactant-oil microemulsion concentrates, especially those suitable for use both neat and diluted as cleaning compositions, and to a method of cleaning using the said concentrates.
• Aqueous cleaning compositions generally comprise at least one surfactant component.
• Many known cleaning compositions further comprise water-immiscible components, such as oils, fatty alcohols and/or terpenes. It is known that systems comprising a surfactant, water and these water immiscible components can assume different phase structures.
• phase which comprise surfactant and water are generally recognised: the rod-phase, the lamellar phase and the spherical micellar phase.
• surfactant molecules align in spheres having a diameter approximately twice the molecular length.
• these structures are less than lOnm in diameter.
• Systems exhibiting this phase structure are clear, have a viscosity similar to water and cannot suspend particles.
• the rod phase can be considered as a spherical phase which has been encouraged to grow along one dimension. It is known that this can be achieved by the addition of oils. Typically, the rods grow to relatively large length as compared with the diameter, resulting in highly viscous, often opaque solutions. Although the viscosity of these systems is relatively high as compared with spherical micellar solutions, any suspended particles will eventually phase separate.
• the lamellar phase is believed to be characterised by the presence of extensive bi-layers of aligned surfactant molecules separated by water layers. These systems are generally of lower viscosity than the rod phase systems, are often opaque and can suspend particles.
• 'microemulsions' are believed to be oil-in-water emulsions wherein the oil droplets are sufficiently small that a visibly clear system results.
• the term 'microemulsion' is restricted to those systems in which particle size measurements reveal a particle size range of 10-lOOnm. These systems have a low viscosity and will not suspend particles, but differ from spherical micelles in that they exhibit low interfacial tensions in the presence of other oily materials such as are common in fatty soils.
• microemulsions have a similar overall composition to the rod micellar systems which can be obtained by adding oil to a spherical micellar system but have a completely different phase structure and distinct physical properties. It is believed that in the microemulsions the oil phase is segregated into discrete droplets stabilised by a surfactant shell whereas in the rod phase, the oil phase is mixed with the surfactant to form a mixed micellar structure.
• liquid surfactant compositions should be as concentrated as is convenient given the mode of use. This not only reduces the energy cost in transport but also reduces the packaging requirement for a given quantity of product.
• GB 2190681 (Colgate: 1987) and EP 316726 (Colgate: 1987) relate to systems which comprise both anionic and nonionic surfactant, together with a cosurfactant, a water- immiscible hydrocarbon such as an oily perfume and water.
• Surfactants may comprise solely anionic surfactants although mixtures of anionics and nonionics are preferred. According to these texts, (see page 5, lines 31ff. of the GB specification) the cosurfactant is essential in that in the absence of this component the surfactants and the hydrocarbon will form a non-microemulsion phase structure.
• Suitable cosurfactants are said to include glycol ether solvents such as Butyl Carbitol (RTM) which is miscible with water and Butyl Cellosolve (RTM) which is highly water soluble. These systems are very sensitive to the type of surfactant present and it appears difficult to reproduce these systems without using the precise components specified.
• glycol ether solvents such as Butyl Carbitol (RTM) which is miscible with water and Butyl Cellosolve (RTM) which is highly water soluble.
• GB 2144763 (P&G: 1983) relates to microemulsion systems which contain magnesium salts. Examples demonstrate that aqueous liquid compositions can be prepared with anionic surfactants alone and with mixtures of anionic and nonionic surfactants.
• US 4511488 (Penetone: 1985) relates to compositions which are described as clear, flowable compositions and which comprise 10-60wt% of d-limonene (a citrus oil) , 10-30wt% surfactant, and, 20-70wt% water, in the presence of a coupling agent such as a glycol ether solvent, in particular Butyl Carbitol. It has been found by experiment that high nonionic compositions such as are described in example 7 of this patent are not stable and phase separate rapidly on standing both in neat form and at x4 dilution.
• microemulsions generally comprise water, a surfactant mixture, an oil and a solvent.
• the surfactants are typically mixtures of anionic and nonionic surfactant.
• the oil is generally a perfume oil.
• the solvent is often referred to as a 'cosurfactant' or a 'coupling agent' and is generally a glycol ether.
• a concentrated microemulsion is a composition which can be diluted with water to produce a microemulsion as defined above. Accordingly, the present invention provides an aqueous cleaning composition which upon aqueous dilution by a factor of at least two produces a stable emulsion, said emulsion having a measured dispersed phase particle size of 10-100 nanometeres, said composition including:
• a surfactant system comprising at least one alkoxylated alcohol nonionic surfactant and not more than 20wt% on surfactant of anionic, cationic, amphoteric or zwitterionic surfactant,
• composition having a measured dispersed phase particle size of greater than lOOnm prior to dilution.
• compositions according to the invention are of relatively high viscosity and exhibit the property of clinging to a sloping surface, while, on dilution, they form mobile microemulsions.
• compositions of the present invention in their undiluted form, generally exhibit the property of bi ⁇ refringence, thereby indicating that a lamellar phase structure is present. Upon dilution, the bi-refringent property is lost, indicating that the lamellar phase structure is no longer present.
• compositions should form a microemulsion over a range of dilution.
• dilution takes the composition into a rod phase it is possible that the resulting increase in viscosity will hinder further dilution.
• dilution takes the composition into the spherical phase the advantages of a microemulsion are lost, especially if physical separation of the oil phase occurs.
• Preferred compositions according to the present invention form microemulsions when diluted with water to any dilution in the range x2-xl6.
• compositions of the present invention have a particle size of above lOOnm in the neat (i.e. concentrated) form.
• microemulsions are characterised by a measured particle size of 10-100 run.
• the products of the present invention will be viscous liquids or gels which dilute to thin liquids on addition of at least an equal volume of water.
• the compositions according to the invention are not microemulsions in their neat form.
• the invention also extends to a process for cleaning a surface which comprises the step of treating the surface with a composition according to claim 1.
• compositions of the invention comprise alkoxylated alcohol nonionic surfactant.
• Suitable alkoxylated alcohol nonionic surfactants can be broadly described as compounds produced by the condensation of alkylene oxide groups, which are hydrophilic in nature, with an organic hydrophobic compound which may be aliphatic or alkyl aromatic in nature.
• the length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.
• Particular examples include the condensation product of aliphatic alcohols having from 8 to 22 carbon atoms in either straight or branched chain configuration with ethylene oxide, such as a fatty alcohol ethylene oxide condensate having from 2 to 15 moles of ethylene oxide per mole of fatty alcohol.
• ethylene oxide such as a fatty alcohol ethylene oxide condensate having from 2 to 15 moles of ethylene oxide per mole of fatty alcohol.
• Particularly preferred nonionic surfactants are those wherein the average composition conforms to the general formula:
• Particularly preferred surfactants include the C 8-13 E 4 _ 8 (average) alcohol ethoxylates .
• examples of these materials include IMBENTIN 91-35 OFA (RTM) and DOBANOL 23- 6.5 (RTM) .
• alkylphenols whose alkyl group contains from 6 to 12 carbon atoms with 5 to 25 moles of ethylene oxide per mole of alkylphenol.
• the alkyl nonionics are preferred over the alkylphenyl nonionics for environmental and ease of formulation reasons.
• the nonionics have a monomodal distribution of EO chain lengths, i.e. mixtures of different ethoxylates are not preferred.
• the amount of nonionic detergent active to be employed in the detergent composition of the invention will generally be from 15 to 30%, preferably from 20 to 30% by weight.
• compositions are essentially free of anionic surfactants and preferably essentially free of any charged surfactants.
• level of anionic is below 2%wt of the level of nonionic surfactant present.
• aqueous solubility should lie in the range 4-11%. Solubility can be determined by experimental methods known to the skilled worker.
• Solvents which have an aqueous solubility above ll%w/w in water such as ethanol (miscible) , 2-butanol (solubility >20%), isopropyl alcohol (miscible), ethylene glycol derivatives (including butoxy ethanol [available as Butyl Cellosolve (TM) ] : miscibility >20%) , Butyl Digol (miscible) and diethylene glycol (miscible) do not give good results as the products become thin. It is preferred that the compositions according to the invention are essentially free of these solvents.
• the preferred alcoholic solvents include n-Butanol (soluble to 8%wt in water) and iso-butanol (soluble to 10%wt in water) . '
• Relatively insoluble glycol ethers are particularly preferred. We have determined that excellent performance is attained when the solvent has a solubility in water of from 5-10%. Solvents which are particularly preferred are those selected from the group comprising n-butoxy propanol (available as Dowanol PnB (RTM): soluble to 6%), di- propylene glycol monobutyl ether ' (available as Dowanol DPnB (RTM) : soluble to 5%) and mixtures thereof.
• Solvents which are particularly preferred are those selected from the group comprising n-butoxy propanol (available as Dowanol PnB (RTM): soluble to 6%), di- propylene glycol monobutyl ether ' (available as Dowanol DPnB (RTM) : soluble to 5%) and mixtures thereof.
• solvents having an aqueous solubility in the range 4-11% with other, more highly water-soluble solvents having an aqueous solubility above 12% are not excluded, but is preferred that the more highly water- soluble solvents are absent.
• the preferred level of solvent lies in the range 8-15%wt on product.
• composition of the invention is intended to remove fatty soil it is believed that the oil must be a good solvent for fatty matter, especially those containing triglyceride.
• the rate at which any particular fatty soil dissolves in an oil can be simply determined by experiment.
• oils have a miscibility with water of less than 1% w/w.
• Preferred oils are either:
• Preferred cyclic hydrocarbon oils are limonene and para- cymene.
• Preferred ethers include di-butyl ether.
• Preferred esters include butyl butyrate and amyl acetate. These are all hydrophobic liquids which can rapidly dissolve >20% of their own weight of triglyceride.
• Longer chain esters such as ethyl decanoate are less preferred. These will dissolve sufficient quantity of fat but are believed to do so too slowly for effective cleaning.
• Non-cyclic hydrocarbon oils such as dodecane and hexadecane, and branched species such as citral (polar acyclic terpene) and the ISOPAR (TM) series (branched chain hydrocarbons) and water insoluble alcohols such as n-decanol, which dissolve less than 15%w/w of fat over a long period (several hours) and are considered less suitable for use in those embodiments of the present invention where fatty soil removal from hard surfaces is important.
• TM branched chain hydrocarbons
• the ratio between the weight percentages of the solvent (c) and the oil (d) is such that (c) : (d) ⁇ 1.5:1. In the most preferred embodiments of the invention the ratio is 0.9-0.4:1 as solvent:oil. We have determined that the presence of significantly larger quantities of solvent than oil leads to a product which is not stable over a range of temperatures or does not form a viscous lamellar phase.
• the important properties of the oil can extend beyond an ability to dissolve fatty soil. It is envisaged that by choice of a suitable oil embodiments of the invention might ensure delivery of a persistent perfume a sunscreen or an insect repellant.
• Typical levels of oil on product range from 6-18%wt, levels of 8-16%wt are particularly preferred.
• compositions of the present invention where these are adapted to particular uses.
• optional components can be selected from the usual components employed such as perfumes, preservatives, colouring agents, antifoaming components, polymers, pH modifiers and the like, providing that the composition retains its non-microemulsion form, of particle size >100nm when these components are added and can still be diluted to give a microemulsion.
• the level of hydrotrope should preferably not exceed 2% of the weight of nonionic surfactant present. More preferably, the level of hydrotrope should be lower than the amount effective to destabilise the lamellar phase as indicated by a removal of the property of birefringence from the neat product.
• Compositions according to the present invention are preferably essentially free of hydrotropes.
• Hydrotropes include: aromatic sulphonates such as cumene, xylene and toluene sulphonate, urea, C1-C5 alcohols particularly ethanol an isopropyl alcohol, C2-C5 glycols, particularly ethylene glycol.
• compositions according to the present invention include:
• ethoxylated nonionic surfactant selected from the group comprising: the condensation products ethylene oxide with aliphatic alcohols having from 8 to 22 carbon atoms in either straight or branched chain configuration; the condensation products of ethylene oxide with alkylphenols whose alkyl group contains from 6 to 12 carbon atoms; and mixtures thereof;
• compositions being essentially free of anionic surfactant, essentially free of hydrotrope and comprises a weight excess of oil(c) over solvent (b).
• compositions according to the invention are clear and dilute to form clear solutions.
• the 'NONIONIC surfactant was Imbentin 91-35 OFA (RTM) a 5EO, 9-11 carbon alcohol ethoxylate.
• 'SOLVENT' was DOWANOL PnB (RTM, ex. DOW) and 'OIL' is limonene.
• 'Score (a) ' is representative of extent of the spontaneous emulsification which the product exhibits on triglyceride samples on a glass microscope slide.
• Commercially available lard - 'Silver Cloud Fat' (TM) was spread onto the slide using a cotton bud to give a streaky but fairly uniform fat film.
• the glass slide was then mounted onto a microscope, a drop of test solution placed onto the fat film and the interaction between the liquor and the fat monitored over a few minutes at RT (no mechanical input) .
• the interaction could also be recorded by means of a video camera. Performance was scored on the following scale:
• 'Score (b) ' is representative of the extent of cleaning using a 'spot test', in which clean Decamel (RTM) tiles are sprayed with a model kitchen soil (a mix of triglycerides, fatty acid, clay and carbon) and allowed to stand at room temperature overnight before use.
• RTM Decamel
• a model kitchen soil a mix of triglycerides, fatty acid, clay and carbon
• Samples of liquors were applied to the soiled tiles at room temperature and the drops allowed to spread and remain in contact with the soil for about 20/30 seconds (up to about 4 minutes in the case of particularly ineffective solutions) .
• the spots of liquid were then rinsed under the tap (hard water) or with a wash bottle (demin water).
• 'Spontaneous Cleaning' was assessed on the following scale according to the amount of visible soil remaining on the tile after rinsing. 5 Excellent - complete soil removal,
• Particle size was determined by use of a Malvern 4700 (TM) photon correlation spectrophotometer using the method given in the operating handbook.
• TM Malvern 4700
• NONIONIC 24 24 24 24 24 24 24 24
• examples la and 2a are embodiments of the invention.
• examples lb and lc illustrate the effects of diluting the composition of example la by factors of 8 and 16 respectively, whereas examples 2b, 2c and 2d illustrate the effects of dilution on the composition of example 2a by 4, 8 and 16 respectively.
• Examples Id and le are comparative examples which demonstrate the cleaning behaviour of compositions which are similar to la but which have components absent.
• both examples la and 2a provide non-microemulsions, having a particle size above the lOOnm limit. These compositions both exhibit bi ⁇ refringence.
• microemulsions are believed to be produced as the products obtained are thin, clear, have a particle size consistent with icroemeulsions and do not exhibit bi-refingence. It can be seen, particularly from example 2, that cleaning performance is maintained at up to 16 times dilution.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Emergency Medicine (AREA)
• Detergent Compositions (AREA)
• Edible Oils And Fats (AREA)

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• 1994
  • 1994-07-06 GB GB9413612A patent/GB9413612D0/en active Pending
• 1995
  • 1995-06-29 CA CA 2191857 patent/CA2191857A1/en not_active Abandoned
  • 1995-06-29 EP EP95925789A patent/EP0769043B1/de not_active Revoked
  • 1995-06-29 AU AU29790/95A patent/AU704076B2/en not_active Ceased
  • 1995-06-29 ES ES95925789T patent/ES2136867T3/es not_active Expired - Lifetime
  • 1995-06-29 BR BR9508238A patent/BR9508238A/pt not_active Application Discontinuation
  • 1995-06-29 DE DE69511555T patent/DE69511555T2/de not_active Revoked
  • 1995-06-29 WO PCT/EP1995/002533 patent/WO1996001305A1/en not_active Application Discontinuation

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