Patent Application
20170121654
The present invention relates to methods of cleaning dishware comprising a direct-foam cleaning product.
Hand dishwashing is typically performed by applying dishwashing detergent to a sponge or cleaning implement and scrubbing dishware with the implement; or adding the detergent to a water bath in a sink and soaking/scrubbing the dishware in the detergent water bath. Such conventional methods but may take the consumer longer periods of time than necessary to clean dishware when it is not heavily soiled or when there are only a few items to clean (e.g. knife, spatulas, soup ladles, etc used briefly to prepare food). Such conventional methods may also result in wasted dishwashing detergent product (i.e. dosed amount may be more than needed to clean the dishware).
Finding efficient ways of cleaning dishware may be desired by many consumers. One approach to quicker cleaning is direct application of dishwashing detergent onto the soiled dishware followed by an optional light scrub and then a water rinse. One attempt in the art of direct-foam cleaning is “Method Power Foam Dish Soap” dishwashing detergent sold by Methods Products (San Francisco, Calif., U.S.A.). The Method product provides a dishwashing composition in a spray bottle. Current direct-foam dishwashing products, however, may not effectively clean dishware and may not provide good surface area foam coverage and/or lasting foam coverage for efficient cleaning. To compensate for the lack of coverage and non-lasting coverage, multiple spray actions are needed which can negatively affect user experience, lead to overconsumption of the cleaning product, and may also increase product bounce back from surfaces when spraying. Such bounce back can cause wasted product and possible product inhalation risks.
As such, it is desirable to improve cleaning efficiency by providing good coverage on surfaces per dose of the direct-foam cleaning product with minimal bounce back and without compromising tough food cleaning.
The invention comprises a method of cleaning dishware comprising the steps of:
providing a sprayer having a cleaning composition contained therein, wherein said cleaning composition comprises from about 5% to about 15%, by weight of said composition, of a surfactant system and an effective amount of a grease cleaning organic solvent;
spraying said cleaning composition onto a dishware to form a direct-foam cleaning product on said dishware, wherein said direct-foam comprises a compression force from about 2.4 gf*mm to about 4.3 gf*mm; and
rinsing or wiping said direct-foam cleaning product from said dishware.
The invention also comprises a method of cleaning dishware comprising the steps of:
providing a spray dispenser having a cleaning composition contained therein, wherein said cleaning composition comprises from about 5% to about 15%, by weight of said composition, of a surfactant system;
spraying said cleaning composition onto a dishware to form a direct-foam cleaning product on said dishware, wherein said direct-foam comprises a compression force from about 2.4 gf*mm to about 4.3 gf*mm, a foam density from about 0.08 g/ml to about 0.3 g/ml, and wherein said foam defines an overall area from about 50 cm2 to about 75 cm2 and a central area from about 30 cm2 to about 45 cm2;
rinsing or wiping said direct-foam cleaning product from said dishware.
Further features of the invention are set forth in the following detailed description of the invention and in the drawing figures.
The direct-foam cleaning product of the present invention includes a cleaning composition dispensed from a spray dispenser to form a direct-foam. A “direct-foam” or “direct-product”, as used herein, is a product that forms a foam on the surface to which it is applied, without requiring additional physical, chemical, or like interventions. For example, manual rubbing of a product on a surface to produce a foam once the product is dispensed from its container is not a direct-foam product. The direct foam product is applied to the surface directly from the container in which it was stored.
The cleaning composition can be dispensed from a pre-compression sprayer or an aerosol sprayer with a pressure control valve, both commercially available in the art. Suitable pre-compression sprayers in which a buffer mechanism to control the maximum pressure can be added include the Flairosol® spray dispenser, manufactured and sold by Afa Dispensing Group (The Netherlands) and the pre-compression trigger sprayers described in U.S. Patent Publication Nos. 2013/0112766 and 2012/0048959. A “pre-compression sprayer”, as used herein, is a sprayer with a pre-compression valve to control the minimum pressure required for liquid to release from the trigger sprayer and a buffer mechanism to control the maximum pressure of liquid being pumped to the buffer chamber. It is also contemplated that the cleaning composition may be dispensed from a conventional trigger sprayer. When the composition is dispensed from a pre-compression sprayer, the cleaning composition provides a direct-foam product having a wide ring-like foam pattern. While
Referring to
The pre-compression sprayer 1 may include an actuation element, such as a trigger 14 as shown in
When the trigger 14 is actuated or pulled in by a user, it creates a down stroke in the compression chamber 20. The piston 22 moves down and pushes liquid into the buffer chamber 30 towards the pre-compression valve 40. The inlet valve 16 closes and the outlet valve 36 opens, thus letting the liquid composition 100 pass to the buffer chamber 30 and to the pre-compression valve 40 (pressure moves it downwards into its open position). When the trigger 14 is actuated, the inlet valve 16 closes, preventing the liquid from the compression chamber 20 being pushed back into the bottle/reservoir (pressure moves it downwards into closed position).
The pressure of the liquid composition 100 in the buffer chamber 30 pushes down on the buffer piston 32, and the buffer spring 34 underneath the buffer piston 32 is thereby compressed, thus allowing liquid composition temporarily to be stored under pressure (pressurized) in the buffer chamber 30. There is an overflow valve (not shown) at a certain depth of the buffer chamber 30. This is done to prevent too much build up of liquid pressure and, thus, is a kind of outlet at a certain defined point beyond which the buffer piston 32 cannot travel downward. Thus, when the buffer piston 32 moves beyond a certain point (at maximum desired pressure/spring force), liquid will flow back into the reservoir through an overflow valve in the buffer chamber 30. The liquid overflow valve can be set for a maximum buffer spring 34 pressure in the buffer chamber 30 of, for example, 0.5 to 3.0, or 0.5 to 1.0 bar, above the preset opening pressure of the pre-compression valve 40. In exemplary embodiments of the present invention, such pre-compression valve opening pressure can be, for example, 1.5, 2.5, 3.5 or even 6 bar or more. It is noted that in exemplary embodiments of the present invention, the pre-compression valve 40 has a lower opening pressure than the maximum pressure that can develop in the buffer chamber 30. In this way, the pre-compression valve 40 will open and spray can occur well before the buffer chamber 30 is fully filled with liquid and thus reaching its maximum pressure. This allows for continuous spray conditions. More particularly, when more liquid is available in the sprayer than the nozzle 50 can spray (the nozzle is restricted by the maximum flow rate through the nozzle), the remaining liquid is stored in the buffer chamber 30 and is gradually released over a certain time until the pressure drops below the pre-compression valve closing pressure which will shut off the liquid flow. This allows for long duration spraying with a single actuation and continuous spraying with multiple actuations at certain actuation intervals. For instance, if the nozzle 50 can only spray 1 ml/s and 1.4 ml of liquid is pumped in one actuation, the spray will continue for 1.4 seconds. If three actuations of 1.4 ml of liquid will be pumped in 2 seconds, the sprayer will continue spraying for 4.2 seconds.
The pre-compression valve 40 controls the spray action from the nozzle 50. The pre-compression valve 40 has a defined pressure; when the pressure of the liquid exceeds such defined pressure, the pre-compression valve opens and a spray results. When the pressure falls below the defined closing pressure of pre-compression valve 40, the pre-compression valve closes, thereby insuring that only properly pressurized liquids can proceed to the nozzle 50 an insure a continuous spray. The pre-compression valve 40 opens because of the liquid pressure in the buffer chamber 30, and the liquid composition 100 thus passes towards the nozzle 50 creating a desired spray.
When the trigger 14 is actuated, the inlet valve 16 also closes, preventing the liquid from the compression chamber 20 being pushed back into the bottle/reservoir (pressure moves it downwards into closed position). Although the pre-compression sprayer 1 may be in a subsequent trigger release and liquid intake step, liquid composition 100 can still pass by the pre-compression valve 40 and through the orifice 60 to continue the spray. It is in this manner that a user can cause a continuous spray—as long as the user continues to pump the trigger 14 such that the liquid intake strokes keeps up with the spray, liquid composition 100 continues to be drawn up and sent to the pressure chamber and the pre-compression valve. In this context, it is noted that by varying the relative volumes of the compression chamber 20 and the buffer chamber 30, various speeds of pumping can be designed.
Referring now to
Referring to
The spin grooves 54 can vary in shape, width and depth and can taper from wide to narrow to accommodate the best acceleration of the flow of the liquid with the least resistance and pressure drop. The inner cone 56 may have an angle of about 20° to about 120° and defines how much the spinning liquid is further accelerated before the orifice 60 and, as such, the spread or how wide the spray comes out of the orifice 60. The spin grooves 54 accelerate and swirl the liquid under pressure into the inner cone 56 where the gradual reduction in diameter compresses and accelerates the liquid further to spray it out under high pressure through the narrow orifice 60. The sudden pressure drop at the exit of the orifice 60 allows the compressed highly energized liquid to expand and breaks up the liquid into small droplets. The velocity, direction, and spray width of the sprayed droplets is defined by the energy and the trajectory introduced by the spin grooves 54 and the angle on the inner cone 56. The short cylindrical path in the orifice 60 should be kept as short as technically possible to not impact the width of the spray.
On the outside of the orifice 60 or downstream of the orifice, an external cone 58 is provided which guides the spray angle of liquid droplets exiting the orifice. This external cone 58 may have an angle of about 20° to about 120°, or about 100°. The sudden pressure drop at the exit generates an under pressure in the center of the spray. This under pressure will suck in air from the environment into the spray and the small droplets being formed at the exit turn into small foam bubbles. This effect is further enhanced by the external cone 58 which also guides the liquid stream outwards to further break up the spray into a wide foam spray pattern. The foam particles can be further tuned by introducing more air through additional venting holes in the external cone positioned close to the zone with the highest under pressure. Via the venturi effect this under pressure will suck in more air into the stream of droplets generating thicker, more pronounced foam.
The orifice 60 may be of constant diameter or may taper in the axial direction, widening in diameter as the spray travels from a proximal end (i.e. closest to the orifice 60 and the flow path 200) to a distal end of the nozzle 50. A constant orifice diameter may be about 0.10 mm to about 0.60 mm, or about 0.30 mm to about 0.40 mm, or about 0.32 mm to about 0.37 mm, or about 0.36 mm. When tapered, the orifice 60 may taper from a proximal end diameter of about 0.13 mm to a distal end diameter of about 1 mm to about 5 mm to a distal end diameter of about 0.10 mm to about 0.60 mm, or about 0.30 mm to about 0.40 mm.
Exemplary nozzle configurations are provided in Table 1.
Although particular aspects of the pre-compression sprayer 1 and nozzle 50 of the invention have been described above, it should be understood that other modifications and variations could be made to the trigger sprayer and nozzle without departing from the scope of the invention defined by the claims.
The direct-foam cleaning product of the present invention comprises a cleaning composition comprising a surfactant system and, optionally, an organic grease cleaning solvent. The suds generated when spraying the cleaning composition of the invention are strong enough to withstand the impact force when the direct-foam cleaning product contacts the article to be washed (i.e. minimizes bounce back, inhalation, and product waste), but at the same time are easy to rinse. The direct-foam cleaning product of the invention provides good cleaning, including cleaning of tough food soils such as cooked-, baked- and burnt-on soils and good cleaning of light oily soils. The direct-foam cleaning product of the invention also provides good detergent spreading, requiring reduced scrubbing by the consumer.
Surfactant System
The cleaning composition comprises from about 5% to about 15%, or from about 6% to about 14%, or from about 7% to about 12%, by weight of the composition, of a surfactant system. The surfactant system may comprise an anionic surfactant. The surfactant system may also comprise a co-surfactant selected from the group consisting of amphoteric surfactants, zwitterionic surfactants, and mixtures thereof. The surfactant system can optionally comprise a non-ionic surfactant and/or a cationic surfactant.
The presence of small droplets (and therefore the risk of inhalation) is minimized when the surfactant system contains an anionic surfactant. Anionic surfactants include, but are not limited to, those surface-active compounds that contain an organic hydrophobic group containing generally 8 to 22 carbon atoms or generally 8 to 18 carbon atoms in their molecular structure and at least one water-solubilizing group that may be selected from sulfonate, sulfate, and carboxylate so as to form a water-soluble compound. Usually, the hydrophobic group will comprise a linear or branched C8-C22 alkyl, or acyl group. Such surfactants are employed in the form of water-soluble salts and the salt-forming cation usually is selected from sodium, potassium, ammonium, magnesium and mono-, di- or tri-alkanolammonium.
The anionic surfactant may be a sulfate anionic surfactant. The sulfate anionic surfactant may be an alkoxylated sulfate anionic surfactant or an alkoxylated sulfate anionic surfactant having an average alkoxylation degree from about 2 to about 5, or about 3. It has been found that alkyl ethoxy sulfate with an average degree of ethoxylation from about 2 to about 4, or from about 3, performs well in terms of cleaning and speed of cleaning. When the sulfate anionic surfactant is a mixture of sulfate anionic surfactants, the average alkoxylation degree is the weight average alkoxylation degree of all the components of the mixture. In the weight average alkoxylation degree calculation, the weight of sulfated anionic surfactant components not having alkoxylate groups should also be included.
Weight average alkoxylation degree=(x1*alkoxylation degree of surfactant 1+x2*alkoxylation degree of surfactant 2+ . . . )/(x1+x2+ . . . )
If the sulfate anionic surfactant is branched, the branching group is an alkyl. Typically, the alkyl is selected from methyl, ethyl, propyl, butyl, pentyl, cyclic alkyl groups and mixtures thereof. Single or multiple alkyl branches could be present on the main hydrocarbyl chain of the starting alcohol(s) used to produce the sulfate anionic surfactant used in the present direct-foam product. The branched sulfate anionic surfactant can be a single anionic surfactant or a mixture of anionic surfactants. In the case of a single surfactant, the percentage of branching refers to the weight percentage of the hydrocarbyl chains that are branched in the original alcohol from which the surfactant is derived. In the case of a surfactant mixture, the percentage of branching is the weight average, and it is defined according to the following formula:
Weight average of branching (%)=[(x1*wt % branched alcohol 1 in alcohol 1+x2*wt % branched alcohol 2 in alcohol 2+ . . . )/(x1+x2+ . . . )]*100
Suitable sulfate surfactants for use herein include water-soluble salts of C8-C18 alkyl, preferably C8-C18 alkyl comprising more than 50% by weight of the C8 to C18 alkyl of C12 to C14 alkyl or hydroxyalkyl, sulfate and/or ether sulfate. Suitable counterions include alkali metal cation, earth alkali metal cation, alkanolammonium or ammonium or substituted ammonium, or sodium. The sulfate surfactants may be selected from C8-C18 alkyl alkoxy sulfates (AExS) wherein x is from 1-30 in which the alkoxy group could be selected from ethoxy, propoxy, butoxy or even higher alkoxy groups and mixtures thereof. The sulfate surfactants may be C12-C14 alkyl ethoxy sulfate with an average degree of ethoxylation from about 2 to about 5, or about 3. Alkyl alkoxy sulfates are commercially available with a variety of chain lengths, ethoxylation and branching degrees. Commercially available sulfates include, those based on Neodol alcohols ex the Shell company, Lial-Isalchem and Safol ex the Sasol company, natural alcohols ex The Procter & Gamble Chemicals company.
If the anionic surfactant is branched, it is preferred that the branched anionic surfactant comprises at least 50%, or at least 60% or at least 70% of a sulfate surfactant, by weight of the branched anionic surfactant. From a cleaning view point, the anionic surfactants are those branched surfactants in which the branched anionic surfactant comprises more than 50%, or at least 60% or at least 70% by weight thereof of sulfate surfactant and the sulfate surfactant is selected from the group consisting of alkyl sulfate, alkyl ethoxy sulfates and mixtures thereof. Even more preferred are those in which the branched anionic surfactant has an average degree of ethoxylation of from about 2 to about 5, more preferably about 3 and even more preferably when the anionic surfactant has an average level of branching of from about 10% to about 35%, or from about 20% to 30%.
Another anionic sulfate surfactant are branched short chain alkyl sulfates. Such anionic sulfate surfactant have a linear alkyl sulfate backbone, the backbone comprising from 4 to 8, or from 5 to 7 carbon atoms, substituted with one or more C1-C5 or C1-C3 alkyl branching groups in the C1, C2 or C3, or C2 position on the linear alkyl sulfate backbone. This type of anionic surfactant has been found to deliver strong grease cleaning as well as good foaming performance, especially immediate foaming performance upon spraying when the composition comprises amine oxide or betaine, as a co-surfactant. The sulfate group within the branched short chain alkyl sulfate surfactant is bonded directly to said C4-C8 linear backbone in terminal position. The linear alkyl sulfate backbone may comprise from 5 to 7 carbon atoms. The one or more alkyl branching groups are selected from methyl, ethyl, propyl or isopropyl. The branched short chain alkyl sulfate surfactant has only one branching group substituted on its linear backbone chain. The alkyl branching group may be on the C2 position in the linear alkyl sulfate backbone.
The branched short chain alkyl sulfate according to the current invention may have a linear alkyl backbone comprising from 5 to 7 carbons, substituted on the C2 position in the linear alkyl sulfate backbone with one alkyl branching group selected from methyl, ethyl, propyl. The branched short chain alkyl sulfate surfactant may be 2-ethylhexylsulfate. This compound is commercially available under the Syntapon EH tradename from Enaspol and Empicol 0585U from Huntsman. The branched short chain alkyl sulfate surfactant will be formulated from about 3% to about 10%, or from about 4% to about 8%, by weight of the composition. The branched short chain alkyl sulfate surfactant will be formulated from about 50% to about 100%, or from about 55% to about 75%, by weight of the total surfactant composition.
Co-Surfactant
The surfactant system may also comprise a co-surfactant selected from the group consisting of amphoteric surfactants, zwitterionic surfactants, and mixtures thereof. The amphoteric surfactant may be an amine oxide. “Co-surfactant” as used herein means a surfactant that is present in the composition in an amount lower than the main surfactant. “Main surfactant” as used herein means the surfactant that is present in the composition in the highest amount. The co-surfactant seems to help with the sudsing of the product.
Suitable amine oxides are alkyl dimethyl amine oxide, alkyl amido propyl dimethyl amine oxide, and coco dimethyl amino oxide. Amine oxide may have a linear or mid-branched alkyl moiety. Typical linear amine oxides include water-soluble amine oxides containing one R1 C8-18 alkyl moiety and 2 R2 and R3 moieties selected from the group consisting of C1-3 alkyl groups and C1-3 hydroxyalkyl groups. Preferably amine oxide is characterized by the formula R1-N(R2)(R3)O wherein R1 is a C8-18 alkyl and R2 and R3 are selected from the group consisting of methyl, ethyl, propyl, isopropyl, 2-hydroxethyl, 2-hydroxypropyl and 3-hydroxypropyl. The linear amine oxide surfactants in particular may include linear C10-C18 alkyl dimethyl amine oxides and linear C8-C12 alkoxy ethyl dihydroxy ethyl amine oxides. Preferred amine oxides include linear C10, linear C10-C12, and linear C12-C14 alkyl dimethyl amine oxides. As used herein “mid-branched” means that the amine oxide has one alkyl moiety having n1 carbon atoms with one alkyl branch on the alkyl moiety having n2 carbon atoms. The alkyl branch is located on the a carbon from the nitrogen on the alkyl moiety. This type of branching for the amine oxide is also known in the art as an internal amine oxide. The total sum of n1 and n2 is from 10 to 24 carbon atoms, preferably from 12 to 20, and more preferably from 10 to 16. The number of carbon atoms for the one alkyl moiety (n1) should be approximately the same number of carbon atoms as the one alkyl branch (n2) such that the one alkyl moiety and the one alkyl branch are symmetric. As used herein “symmetric” means that |n1−n2| is less than or equal to 5, preferably 4, most preferably from 0 to 4 carbon atoms in at least 50 wt %, more preferably at least 75 wt % to 100 wt % of the mid-branched amine oxides for use herein. The amine oxide further comprises two moieties, independently selected from a C1-3 alkyl, a C1-3 hydroxyalkyl group, or a polyethylene oxide group containing an average of from about 1 to about 3 ethylene oxide groups. Preferably the two moieties are selected from a C1-3 alkyl, more preferably both are selected as a C1 alkyl.
Other suitable co-surfactants are zwitterionic surfactants. The zwitteronic surfactant may be a betaine surfactant, including alkyl betaine, alkyl amido propyl betaine, sulfo betaine, amido sulfo betaine, or more particularly, cocoamidopropylbetaine.
The anionic surfactant and the co-surfactant may be present in the composition of the present invention in a weight ratio from about 4:1 to about 1:1, or from about 3:1 to about 1:1, or from about 2.8:1 to about 1.3:1. An exemplary surfactant system may comprise: (1) about 4% to about 10%, or about 5% to about 8%, by weight of the composition, of an anionic surfactant, or an alkyl alkoxy sulfate surfactant, or a branched short chain alkyl sulfate; (2) about 1% to about 5%, or about 1% to about 4%, by weight of the composition, of a surfactant selected from the group consisting of amphoteric surfactant, zwitterionic surfactant, and mixtures thereof, or an amine oxide surfactant. It has been found that such surfactant system in combination with the grease cleaning organic solvent of the present invention provides excellent cleaning and a desirable foaming profile.
The surfactant system may optionally comprise commercially available non-ionic surfactants. Suitable nonionic surfactants include the condensation products of alcohols, including guerbet alcohols and guerbet alcohols comprising from 9 to 16 carbon atoms in its alkyl chain and from 2 to 18 moles, or from 2 to 15 moles, or from 5 to 12 of alkylene oxide or ethylene oxide per mole of alcohol. Nonionic surfactants, when present, are comprised in a typical amount of from about 0.1% to about 10%, or about 0.2% to about 8%, or about 0.5% to about 6%, by weight of the composition.
The surfactant system may optionally comprise commercially available cationic surfactants.
Solvent
The composition suitable for the invention may include an organic grease cleaning solvent. An organic grease cleaning solvent, according to the invention, is an organic solvent which, when added to a nil solvent detergent composition comprising between 5 wt. % and 15 wt. % of a surfactant system, improves the oil breakthrough time (vs. the nil solvent detergent composition alone), per the test method described below. A nil solvent detergent composition base matrix may be formulated as shown in Table 2 below.
Oil preparation is carried out at ambient temperature of 21° C.+−2° C. All used products should be acclimatized within this temperature range.
Oil 1: A blend of vegetable based cooking oils is achieved by mixing corn oil (Supplier: Vandemoortele—Item: #1001928), peanut oil (Supplier: Vandemoortele—Item: #1002974) and sunflower oil (Supplier: Vandemoortele—Item: #1001926) in equal weight amounts. While mixing, 0.05 wt. % of red dye (Waxoline Red, red dye pigment supplied by Avecia) is added on top. Mixing is continued for 1 hour to achieve a homogeneous dye distribution over the oil sample.
Oil 2: Olive oil (Supplier: Bertoli—Item: #L5313R HO756 MI0002) is mixed with 0.05% of red dye (Waxoline Red, red dye pigment supplied by Avecia) for 1 hour to achieve a homogeneous dye distribution over the oil sample.
Oil 3: Baked oil mix is made by further mixing the resulting oil from Oil 1 with 1% of black dye (Supplier: Sigma-Aldrich. Item: Sudan black B lot MKBQ9075V) for 1 hour to achieve a homogeneous dye distribution. 20 g of the resulting oil mixture is poured homogeneously distributed as a thin layer over a Pyrex™ glass oven tray (from Carrefour Lx1=30×24 cm). The tray is oven-baked for 16 hours at 135° C. After baking, the oven tray is put overnight in a humidity cabinet at 25° C. and 70% humidity level. The liquid polymerized oil fraction is then collected in a glass vial and ready for testing.
35 grams of a water solution containing 0.15% of xanthan gum (keltrol RD from CP-kelco) is poured onto a glossy white ceramic dish plate (Supplier: Ikea—Item: S.Pryle #13781 diameter 26.5 cm). Then, 2.5 grams of the oil to test is delicately deposited in the middle onto the water surface using a Pasteur pipette (Supplier: VWR—Item: 5 ml #612-1684), thus forming a thin disk of oil layer. The oil disk diameter shall not exceed a variation amongst replicates of more than 20% from the average value. One drop of the detergent sample to test is delicately deposited from a height of less than 5 mm on the middle of the oil disk, using a Pasteur pipette (Supplier: VWR—Item: 5 ml #612-1684). The breakthrough time is the time recorded from the deposition of the solution drop to the opening of the oil disk identified by the apparition of the water layer in the middle of the oil disk. Eight replicates are required per sample (solution type and oil type) to calculate the average breakthrough time for that specific sample/oil combination. The average breakthrough time across the three oil systems (Oil 1, 2, and 3) is calculated and reported for the different test compositions. The lower the breakthrough time the better the cleaning.
The grease cleaning solvent may comprise glycol ethers selected from the group consisting glycol ethers of Formula I, Formula II, and mixtures thereof.
Formula I=R1O(R2O)nR3
Formula II=R4O(R5O)nR6
Suitable glycol ether solvents can be purchased from The Dow Chemical Company, more particularly from the E-series (ethylene glycol based) Glycol Ethers and the P-series (propylene glycol based) Glycol Ethers line-ups. Suitable glycol ether solvents include Butyl Carbitol, Hexyl Carbitol, Butyl Cellosolve, Hexyl Cellosolve, Butoxytriglycol, Dowanol Eph, Dowanol PnP, Dowanol DPnP, Dowanol PnB, Dowanol DPnB, Dowanol TPnB, Dowanol PPh, and mixtures thereof.
The glycol ether of the product of the invention can boost foaming. The glycol ether solvent typically is present from about 1% to about 10%, or from about 2% to about 8%, or from about 3% to about 7%, by weight of the composition.
An exemplary cleaning composition of the present invention may comprise:
The surfactant system and the solvent are in a weight ratio from about 5:1 to about 1:1, or from about 3:1 to about 1:1. Compositions having a surfactant:solvent weight ratio lower than 1:1 do not seem to be able to foam and/or tend to phase separate, creating physical instability in the product. Compositions having a surfactant:solvent weight ratio higher than 5:1 are difficult to spray and are prone to gelling when in contact with greasy soils in the presence of the low levels of water typically present when the product of the invention is used. Gel formation may inhibit the spreading of the composition, impairing cleaning.
Other Optional Ingredients
The composition suitable for the present invention may also comprise other ingredients typically found in cleaning compositions including aminophosphonate or aminocarboxylate chelant, including MGDA or GLDA, builders, and rheology modifying agents such as xanthan gum. The aminocarboxylate chelant not only act as a chelant but also contributes to the reserve alkalinity. This seems to help with the cleaning of cooked-, baked- and burnt-on soils. The composition may also comprise bicarbonate and/or monoethanol and/or carboxylate builders, including citrate builder, that may also contribute to the reserve alkalinity. Other optional ingredients include perfumes, coloring agents, preservatives, solvents, viscosity and pH trimming agents.
The composition for use in the invention may have a pH greater than 8, or from 10 to 12, or from 10.5 to 11.5, as measured at 10% concentration in distilled water at 20° C. The reserve alkalinity of the composition is from about 0.1 to about 1, or from about 0.1 to about 0.5. Reserve alkalinity is herein expressed as grams of NaOH per 100 ml of composition required to titrate the composition at pH 10 to arrive at the pH of the finished composition. The reserve alkalinity for a solution is determined in the following manner. A pH meter (for example an Orion Model 720A) with an Ag/AgCl electrode (for example an Orion sure flow Electrode model 9172BN) is calibrated using standardized pH 7 and pH 10 buffers. A 100 g of a 10% solution in distilled water at 20° C. of the composition to be tested is prepared. The pH of the 10% solution is measured and the 100 g solution is titrated down to pH 10 using a standardized solution of 0.1 N of HCl. The volume of 0.1N HCl required is recorded in ml. The reserve alkalinity is calculated as follows:
Reserve Alkalinity=ml 0.1N HCl×0.1 (equivalent/liter)×Equivalent weight NaOH (g/equivalent)×10.
The pH and reserve alkalinity contribute to the cleaning of tough food soils.
An exemplary composition suitable for the present invention has a pH from 10 to 11.5 as measured in a 10% solution in distilled water at 20° C., a reserve alkalinity from 0.1 to 0.3 expressed as g NAOH/100 ml of composition at a pH of 10, the composition comprising:
Another composition suitable for the present invention has a pH of from 10 to 11.5 as measured in a 10% solution in distilled water at 20° C., a reserve alkalinity of from 0.1 to 0.3 expressed as g NAOH/100 ml of composition at a pH of 10, the composition comprising:
Another exemplary composition has a pH of from 10 to 11.5 as measured in a 10% solution in distilled water at 20° C., a reserve alkalinity of from 0.1 to 0.3 expressed as g NAOH/100 ml of composition at a pH of 10, the composition comprising:
Another exemplary composition has a pH of from 10 to 11.5 as measured in a 10% solution in distilled water at 20° C., a reserve alkalinity of from 0.1 to 0.3 expressed as g NAOH/100 ml of composition at a pH of 10, the composition comprising:
The described levels of surfactants, specific solvents, and the surfactant:solvent weight ratio provide flash suds and long lasting suds. This also provides a direct-foam product with good surface area coverage, especially when combined with a suitable dispenser system, preferably a pre-compression trigger sprayer according to the sprayer disclosed herein, thereby improving cleaning efficiency. The physical characteristics of the direct-foam of the present invention include a certain compression force, central and ring area size, and foam density. The direct-foam cleaning product of the present invention comprises a foam compression force that provides an optimum balance of surface area coverage for efficient cleaning and minimal bounce back for minimal lost chemistry. The compression force of the direct-foam cleaning product of the present invention is about 2.4 gf*mm to about 4.3 gf*mm, alternatively about 2.5 gf*mm to about 4.0 gf*mm, or about 3.0 gf*mm to about 4.0 gf*mm, or about 3.1 to 3.8 gf*mm “gf*mm”, as used herein, is gram-force multiplied by millimeter. The direct-foam product has longevity compression force wherein at least 90%, or at least 95%, of the initial foam compression force is maintained for 5 minutes. While not wishing to be bound by theory, a compression force higher than about 4.3 gf*mm results in a consumer unacceptable dense/sticky foam that covers a small surface area requiring multiple spray strokes by the user for good product coverage on a target surface. The foam density of the direct-foam product may have an average foam density from about 0.08 g/ml to about 0.3 g/ml, or from about 0.09 g/ml to about 0.2 g/ml, or from about 0.10 g/ml to about 0.15 g/ml. A low compression value results in a consumer unacceptable watery/airy foam which leads to higher bounce back levels (i.e. when the foam product hits the target surface, it bounces back and, as such, a certain amount of chemistry is lost from the cleaning area, spoiling the surrounding area and potentially contributing to inhalation risk). The bounce back level of the direct-foam product, when sprayed from a spray dispenser, may be less than about 500 mg, or less than about 200 mg, or less than about 80 mg. The direct-foam product comprises a plurality of bubbles having a mean bubble size from about 200 μm to about 400 μm. Using the Mean Bubble Size test method described herein, the Method product provides a mean bubble size of about 171 μm. The Test Product, according to the present invention, using the Test Product composition described herein in Table 5 and the Spray Dispenser Type 2 described in Table 6, provides a mean bubble size of about 245 μm.
The direct-foam product of the present invention has a foam pattern that is defined by the central area, ring, area, and/or overall area as determined in the Foam Pattern Test Method outlined below. The central area of the foam pattern measures from about 30 cm2 to about 60 cm2, or from about 30 cm2 to about 45 cm2, or from about 35 cm2 to about 45 cm2; and an overall or total area of foam measuring from about 20 cm2 to about 90 cm2, or from about 60 cm2 to about 80 cm2, or from about 50 cm2 to about 75 cm2. The foam in the ring area covers about 1 cm2 to about 20 cm2, or about 10 cm2 to about 20 cm2.
For the purposes of testing to determine characteristics of the composition, such as: Compression Force, Longevity Compression Force, Foam Density, Foam Pattern (includes Ring Area and Central Area), Bounce Back, and Spray Particle Distribution in specified areas, the targeted product (i.e. composition and accompanying spray device) is used to spray the composition to generate direct-foam samples to be tested.
Compression Force Test Method
The characteristic defined herein as the Compression Force is measured on samples of foam generated from the cleaning composition and spray device being tested. The compression force of a direct-foam composition may be measured by the following test method.
The Compression Force test method is conducted in triplicate for each product being tested, in a room having an air temperature of 23+/−2° C. and 50%+/−10% relative humidity (“RH”), while being protected from air currents. The reported Compression Force of a product is the average value from the replicate samples tested.
Longevity Compression Force Test Method:
The characteristic defined herein as “Longevity Compression Force” is measured on samples of foam generated from the cleaning product being tested. This test is conducted following all the instructions provided above for the Compression Force test method, with the following modification: an additional 5 minute time interval is inserted between the time points of immediately after the foam is generated and 5 minutes after the foam is generated. The end result is reported as the Longevity Compression Force.
Foam Density Test Method
The characteristic defined herein as the “Foam Density” is measured on samples of foam generated from the cleaning product being tested.
Foam Pattern Test Method
The Foam Pattern test method measures the reflection of light through the specific area where foam is sprayed. A grayscale light reflection image is obtained using a flatbed scanner (A suitable scanner is Epson™ Scanner Perfection V370) with document scan model. Distilled water (fresh prepared by water purifier, resistivity as 18.2 MΩ·cm at 25° C., e.g. prepared by Milli-Q® Integral with Q-POD® and E-POD® dispensers, Merck KGaA, Germany) is used to calibrate the light reflection. This enables the boundary of the foam pattern to be identified for the area calculations. The Ring Area and the Central Area are used to define the foam pattern
Bounce Back Test Method:
Bounce Back is assessed by means of gravimetrical measurement of captured foam product. Referring to
Mean Bubble Size Test Method
The characteristic defined herein as “Mean Bubble Size” is measured on samples of foam generated from the cleaning composition being tested. Mean bubble size is defined as the average diameter of individual bubbles, calculated by the frequency weighted mean. A microscopy system called Olympus™ BX51 is used to take the foam image. Image-Pro Plus 5.0 (from Media Cybernetics) is used to measure the diameter of bubbles. JMP® Pro 11 (from SAS) is used for statistic analysis on the data.
A glass slide without any coating (Corning® Micro slide, 2949-75×50, thickness: 0.96 to to 1.06 mm) is used for sample prep, as normally used for microscopy. The distance from the sprayer nozzle to the glass slide is around 5 cm to 10 cm. For every spray, five different locations are randomly picked to take the microscopy images. For each sample, five sprays are conducted to get collective images for bubble size measurement and analysis. Four times of magnitude is used. For every single bubble, the inner diameter is used for the calculation. The foam film thickness is not included in the calculation. For one product, the average of bubble sizes and its distribution are based on the data collection on twenty-five images.
Certain physical parameters (e.g. compression force, foam density, central area and ring area and bounce back measurements) were taken on two comparative products and one test product according to Table 5.
Spray Dispenser Types 1 and 2 are constructed per the descriptions in Table 6.
Results are tabulated in Table 7.
Comparative Product 1 has a compression force below the desired compression force range, suffering from a high amount of bounce back product upon spraying and leading to product loss, messiness around the work space. This may also create product inhalation concerns with the consumer.
Comparative Product 2 has a compression force above the desired compression force range and suffers from a too low surface area coverage per spray, requiring consumers to spray multiple times to cover the desired surface area.
The Test Product according to the present invention has compression value within the desired range and demonstrates large surface area coverage with minimal product bounce back levels. Without wishing to be bound by theory, products with high compression force possess a very solid sticky foam pattern, inhibiting the foam to separate over the desired surface area, leading to a small area covered accordingly. Due to this solid sticky nature these foams tend to demonstrate very slow collapsing behavior upon spraying, as demonstrated by their low foam density value, i.e. limited sprays required to achieve 200 ml total product volume in foam density test. Products with a very low compression force possess a more airy and watery and less sticky foam pattern, leading to parts of the foam to be easily bounced back from the surface and the remainder of the foam, as demonstrated by their high foam density values, i.e. due to the low sticky nature of these foams they tend to collapse easily upon spraying, leading to a higher number of sprays requirement to meet a fixed product volume, and as such to a higher foam density value within the foam density test described herein.
All percentages stated herein are by weight unless otherwise specified. The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm” Further, it should be understood that every maximum numerical limitation given throughout this specification will include every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Likewise, every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.
Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015/093324 | Oct 2015 | CN | national |
