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
  • 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
  • C11D17/003—Colloidal solutions, e.g. gels; Thixotropic solutions or pastes
• • 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
  • C11D3/2075—Carboxylic acids-salts thereof
• • 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
  • C11D3/37—Polymers
  • C11D3/3746—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • C11D3/3757—(Co)polymerised carboxylic acids, -anhydrides, -esters in solid and liquid compositions
  • C11D3/3765—(Co)polymerised carboxylic acids, -anhydrides, -esters in solid and liquid compositions in liquid compositions

Definitions

• Liquid automatic dishwasher detergent compositions both aqueous and nonaqueous, have recently received much attention, and the aqueous products have achieved commercial popularity.
• U.S. Patent 3,720,621 discloses a viscoelastic gel detergent composition characterized by its viscosity under low and high shear conditions, pH, and steady state viscoelastic deformation compliance.
• the composition requires the presence of a polycarboxylate polymeric thickener, preferably a crosslinked polyacrylic acid.
• compositions of this patent also, however, require a trivalent metal containing material, especially an aluminum containing material such as alumina and may further include a structuring chelant which may be a salt of carbonate, pyrophosphate or mixture thereof, and preferably the potassium salts.
• a trivalent metal containing material especially an aluminum containing material such as alumina
• a structuring chelant which may be a salt of carbonate, pyrophosphate or mixture thereof, and preferably the potassium salts.
• the recently issued U.S. Patent 4,859,358 discloses the incorporation of metal salts of long chain hydroxy fatty acids, as anti-tarnishing agents, in thickened aqueous automatic dishwashing detergent compositions.
• the compositions are not described as being linear viscoelastic and as exemplified do not include any potassium salts. Additionally, this patent claims that the hydroxy fatty acid does not have an effect upon the viscosity of the composition.
• an improved aqueous liquid automatic dishwasher detergent composition is characterized not only by its linear viscoelastic behavior, substantially indefinite stability against phase separation or settling of dissolved or suspended particles under high and low temperature conditions, very low levels of bottle residue, relatively high bulk density, and substantial absence of loosely bound water, but also by its overall product consistency from batch to batch and run to run and over a wide range of storage and aging conditions, including superior aesthetics, freedom from fish-eyes, absence of crystal formation and growth, and resistance to cup leakage of less than about 10 wt% as well as improved optical properties; and ease of dispensability from the container in which it is stored wherein the composition contains substantially no free (unbound) water.
• the present invention was accomplished upon the discovery that an improved automatic dishwashing composition having low foam properties and reduced spotting of glassware can be formulated by employing a crosslinked polyacrylic acid thickening agent at a minimum critical concentration of 1.2 weight percent without the need of employing a fatty acid in the composition to obtain a composition which has linear viscoelastic characteristics.
• compositions stabilized using fatty acids have several shortcomings. These include:
• the main objective of the present invention is to develop a stable gel composition, which is free from aforementioned problems, wherein the composition is free from any fatty acid moiety.
• the instant invention described herein is based on a space filling model, i.e. the hydynamic phase volume of the polyacrylate gel particles is sufficiently high enough to generate a three dimensional network having viscoelastic properties.
• the minimum concentration of the crosslinked polyacrylic polymer to achieve such a state is about 1.2% and this concentration window can be varied depending upon the total composition.
• the present invention provides an improved linear viscoelastic aqueous liquid automatic dishwasher detergent composition
• substantially bound water optionally, from 0 to 3% by weight of low-foaming chlorine bleach stable water dispersible or soluble organic detergent, active material, from 10 to 35% by weight of a detergent builder salt, from 3 to 20% by weight of a chlorine bleach compound, from 1.2 to 2.0% of at least one branched chained crosslinked polymeric thickening agent having a molecular weight of at least 1,000,000 optionally from 0 to 5.0% of an organic compound having a carboxylic acid group affixed to a phenyl ring or its salts thereof, and optionally a linear crosslinked polycarboxylate having a molecular weight of 150,000 to 300,000 wherein the compositions preferably have a bulk density of from 1.26 g/cm3 to 1.42 g/cm3.
• the linear viscoelastic aqueous liquid automatic dishwasher detergent comprises, by weight,
• a method for preparing the aqueous linear viscoelastic composition comprises the steps of:
• the pH of the aqueous slurry of the branched chained crosslinked polycarboxylate thickener after the neutralization in step (b) and in each succeeding step is maintained at a value of at least 11.
• compositions of this invention are thickened aqueous liquids containing various cleansing active ingredients, detergent builder salts and other detergent adjuvants, structuring and thickening agents and stabilizing components, although some ingredients may serve more than one of these functions.
• compositions of this invention include improved dispensability from its storage container by having a minimum flow rate of 225 grams/minute dispensed through a 0.375" (8.45 mms) opening under normal gravitational force, wherein the preferred flow rate is 225 grams/minute to 325 grams/minute, improved optical properties, improved flow properties upon aging, reduced foaming, reduced spotting of glassware, physical stability, as manifested by little or no phase separation, solid settling or viscosity changes over time or resulting from exposure to low or high temperatures, low bottle residue, low cup leakage of less than 10 wt%, high cleaning performance, e.g. low spotting and filming, soil residue removal, and consistency in product characteristics and performance, and superior aesthetics.
• % of at least one salt stable branched chained crosslinked polymeric thickening agent and water exemplified by highly branched chained crosslinked polyacrylic acids (2) a product bulk density of at least 1.28 g/cc, especially at least 1.32 g/cc, (3) hydrating crosslinked polymeric thickener with heated water, (4) maintaining the pH of the neutralized polymeric thickener at a pH of at least 11, more preferably at least 11.5, and (5) the inclusion in the formula of an organic compound characterized by the formula R1COOX wherein x represents a hydrogen atom or an alkali metal ion and R1 represents a phenyl group or a substituted phenyl group, wherein especially preferred organic compounds are benzoic acid or sodium benzoate.
• the linear viscoelastic aqueous liquid automatic dishwasher detergent compositions of this invention will, at least in the preferred embodiments, satisfy each of the following stability criteria over the aging temperature-time schedule shown by the following Table A: TABLE A Aging Temperature Duration (Weeks) (°F) (°C) Minimum Preferred 140 60 > 1 > 2 120 49 > 6 > 8 100 38 > 13 > 16 Ambient > 24 >> 24 More specifically, the compositions are considered stable if each of the following stability criteria is satisfied for at least the minimum number of weeks for each aging temperature shown in Table A:
• linear viscoelastic or “linear viscoelasticity” means that the elastic (storage) modulus (G') and the viscous (loss) modulus (G'') are both substantially independent of strain, at least in an applied strain range of from 0-50%, and preferably over an applied strain range of from 0 to 80%.
• a composition is considered to be linear viscoelastic for the purposes of this invention, if over the strain range of 0-50% the elastic module G' has a minimum value of 100 dynes/sq.cm., preferably at least 250 dynes/sq.cm., and varies less than 500 dynes/sq.cm., preferably less than 300 dynes/sq.cm., especially preferably less than 100 dynes/sq.cm.
• the minimum value of G' and maximum variation of G' applies over the strain range of 0 to 80%.
• the variation in loss modulus G'' will be less than that of G'.
• the ratio of G''/G' (tan ⁇ ) is less than 1, preferably less than 0.8, but more than 0.05, preferably more than 0.2, at least over the strain range of 0 to 50%, and preferably over the strain range of 0 to 80%. It should be noted in this regard that % strain is shear strain x100.
• the elastic (storage) modulus G' is a measure of the energy stored and retrieved when a strain is applied to the composition while viscous (loss) modulus G'' is a measure of the amount of energy dissipated as heat when strain is applied. Therefore, a value of tan ⁇ , 0.05 ⁇ tan ⁇ ⁇ 1, preferably 0.2 ⁇ tan ⁇ ⁇ 0.8 means that the compositions will retain sufficient energy, when a stress or strain is applied, at least over the extent expected to be encountered for products of this type, for example, when poured from or shaken in the bottle, or stored in the dishwasher detergent dispenser cup of an automatic dishwashing machine, to return to its previous condition when the stress or strain is removed.
• compositions with tan ⁇ values in these ranges therefore, will also have a high cohesive property, namely, when a shear or strain is applied to a portion of the composition to cause it to flow, the surrounding portions will follow.
• this cohesiveness of the linear viscoelastic characteristic the compositions will readily flow uniformly and homogeneously from a bottle at a flow rate of at least 225 grams/minute through a 0.375 inch (8.45 mms) opening when the bottle is tilted parallel to a vertical axis, thereby contributing to the physical (phase) stability of the formulation and the low bottle residue (low product loss in the bottle) which characterizes the invention compositions.
• linear viscoelastic property also contributes to improved physical stability against phase separation of any undissolved suspended particles by providing a resistance to movement of the particles due to the strain exerted by a particle on the surrounding fluid medium.
• Linear viscoelasticity also contributes to the elimination of dripping of the contents when the product is poured from a bottle and hence reduction of formation of drops around the container mouth at the conclusion of pouring the product from a container.
• a still further attribute of the invention compositions contributing to the overall product stability and low bottle residue is the high water absorption capacity of the at least one branched chained crosslinked polyacrylic acid-type thickening agent.
• the density of the composition should be controlled such that the bulk density of the liquid phase is approximately the same as the bulk density of the entire composition, including the polymeric thickening agent.
• This control and equalization of the densities was achieved, according to our earlier invention, by providing the composition with a bulk density of at least 1.32 g/cc.
• a density of 1.42 g/cc is essentially equivalent to zero air content.
• the product density is preferably selected in the range of 1.28 to 1.42 g/cc, especially 1.32 to 1.40 g/cc, and most preferably from 1.35 to 1.40 g/cc.
• the stabilization of air bubbles which may become incorporated into the compositions during normal processing, such as during various mixing steps, is avoided by post-adding the surface active ingredients as well as the organic compound having the previously defined formula R1COOX to the remainder of the composition, under low shear conditions using mixing devices designed to minimize cavitation and vortex formation.
• the surface active ingredients present in the composition will include the main detergent surface active cleaning agent, and will also preferably include anti-foaming agent (e.g. phosphate ester) and the R1C00X.
• anti-foaming agent e.g. phosphate ester
• R1C00X the anti-foaming agent
• Exemplary of the polycarboxylate type thickening agents are crosslinked polyacrylic acid type thickening agents as sold by B.F. Goodrich under their Carbopol trademark, including both the 900 series resins, especially Carbopol 941, which is the most ion-insensitive of this class of polymers, and Carbopol 940 and Carbopol 934, and the 600 series resins, especially Carbopol 614.
• the Carbopol 600 and 900 series resins are hydrophilic high molecular weight, crosslinked acrylic acid polymers having an average equivalent weight of 76, and the general structure illustrated by the following formula: wherein R can be hydrogen or an alkyl chain.
• Carbopol 941 has a molecular weight of 1,250,000; Carbopol 940 has a molecular weight of approximately 3,000,000.
• the Carbopol 900 series resins are highly branched chained and highly crosslinked with polyalkenyl polyether, e.g. 1% of a polyalkyl ether of sucrose having an average of about 5.8 allyl groups for each molecule of sucrose. The preparation of this class of crosslinked carboxylic polymers is described in U.S. Patent 2,798,053. Further detailed information on the Carbopol 900 series resins is available from B.F. Goodrich, see, for example, the B.F. Goodrich catalog GC-67, CarbopolR Water Soluble Resins.
• these thickening resins are preferably copolymers of a water dispersible copolymer of an alpha-beta monoethylenically unsaturated lower aliphatic carboxylic acid crosslinked with a polyether of a polyol selected from oligo saccharides, reduced derivatives thereof in which the carbonyl group is converted to an alcohol group and pentaerythritol, the hydroxyl groups of the polyol which are modified being etherified with allyl groups, there being preferably at least two such allyl groups per molecule.
• Carbopol 614 which is the most chlorine bleach stable of this class of thickening resins.
• Carbopol 614 is also highly stable in the high alkalinity environment of the preferred liquid automatic dishwasher detergent compositions and is also highly stable to any anticipated storage temperature conditions from below freezing to elevated temperatures as high as 120°F (49°C), preferably 140°F (60°C), and especially 160°F (71°C), for periods of as long as several days to several weeks or months or longer.
• polycarboxylate-type refers to water-soluble carboxyvinyl polymers of alpha, beta monoethylenically unsaturated lower aliphatic carboxylic acids, which may be linear or non-linear, and are exemplified by homopolymers of acrylic acid or methacrylic acid or water-dispersible or water-soluble salts, esters or amides thereof, or water-soluble copolymers of these acids or their salts, esters or amides with each other or with one or more other ethylenically unsaturated monomers, such as, for example, styrene, maleic acid, maleic anhydride, 2-hydroxethylacrylate, acrylonitrile, vinyl acetate, ethylene, propylene
• homopolymers or copolymers are characterized by their high molecular weight, in the range of from 500,000, especially from 1,000,000 to 4,000,000, and by their water solubility, generally at least to an extent of up to about 5% by weight, or more, in water at 25°C.
• At least one thickening agent is preferably used in their crosslinked form.
• the cross-linking may be accomplished by means known in the polymer arts, as by irradiation, or, preferably, by the incorporation into the monomer mixture to be polymerized of known chemical cross-linking monomeric agents, typically polyunsaturated (e.g. diethylenically unsaturated) monomers, such as, for example, divinylbenzene, divinylether of diethyleneglycol, N,N'-methylene-bisacrylamide, polyalkenylpolyethers (such as described above), and the like.
• polyunsaturated e.g. diethylenically unsaturated
• divinylbenzene divinylether of diethyleneglycol
• N,N'-methylene-bisacrylamide polyalkenylpolyethers (such as described above), and the like.
• amounts of cross-linking agent to be incorporated in the final polymer may range from 0.01 to 5 percent, preferably from 0.05 to 2 percent, and especially, preferably from 0.1 to 1.5 percent, by weight of cross-linking agent to weight of total polymer.
• degrees of cross-linking should be sufficient to impart some coiling to the otherwise generally linear or non-linear polymeric compound while maintaining the crosslinked polymer at least water dispersible and highly water-swellable in an ionic aqueous medium.
• the amount of the at least one branched chained crosslinked polymeric acid or other high molecular weight, hydrophilic crosslinked polycarboxylate thickening agent used to impart the desired rheological property of linear viscoelasticity will generally be in the range of from 1.2 to 2.0%, preferably from 1.2 to 1.6%, by weight , based on the weight of the composition, although the amount will depend on the particular cross-linking agent, ionic strength of the composition, hydroxyl donors and the like.
• the alkali metal cation will be present in the compositions as the alkali metal cation of the detergent builder salt(s), as well as alkali metal silicate or alkali metal hydroxide components of the compositions.
• the alkali metal cation may also be present in the compositions as a component of anionic detergent, bleach or other ionizable salt compound additive, e.g. alkali metal carbonate.
• Preferred detergent builder salts are sodium tripolyphosphate potassium tripolyphasphate, sodium pyrophosphate and potassium pyrophosphate and mixtures thereof, wherein potassium tripolyphosphate (hydrated or anhydrous) is preferred.
• the total amount of detergent builder salts is preferably from 10 to 35% by weight, more preferably from 15 to 35%, and most preferably from 18 to 30% by weight of the composition.
• alkali metal detergent builder salts When other alkali metal detergent builder salts are present in the formulation, they will usually be present in amounts less than 5% by weight based on the total composition.
• Other builder salts are illustrated by sodium carbonate, potassium carbonate, alkali metal gluconates, alkali metal phosphonates and alkali metal nitriloacetates, eg nitrilotriacetates.
• polyphosphate free formulations one can employ alternative builders to the polyphosphates such as sodium carbonate, potassium carbonate, zeolite, gluconate or phosphonate.
• Foam inhibition is important to increase dishwasher machine efficiency and minimize destabilizing effects which might occur due to the presence of excess foam within the washer during use. Foam may be reduced by suitable selection of the type and/or amount of detergent active material, the main foam-producing component.
• the degree of foam is also somewhat dependent on the hardness of the wash water in the machine whereby suitable adjustment of the proportions of the builder salts, such as NaTPP which has a water softening effect, may aid in providing a degree of foam inhibition.
• each type of ester may represent independently a C12-C20 ethoxylated alkyl or alkyl group.
• the ethoxylated derivatives of each type of ester for example, the condensation products of one mole of ester with from 1 to 10 moles, preferably 2 to 6 moles, more preferably 3 or 4 moles of ethylene oxide can also be used.
• Some examples of the foregoing are commercially available, such as the products SAP from Hooker and LPKN-158 from Knapsack.
• Mixtures of the two types, or any other chlorine bleach stable types, or mixtures of mono- and diesters of the same type, may be employed.
• a mixture of mono- and di-C16-C18 alkyl acid phosphate esters such as monostearyl/distearyl acid phosphates 1.2/1, and the 3 to 4 mole ethylene oxide condensates thereof.
• proportions of 0 to 1.5 weight percent, preferably 0.1 to 0.5 weight percent, of foam depressant in the composition is typical.
• the weight ratio of detergent active component to foam depressant generally ranges from 10:1 to 1:1 and preferably about 5:1 to 1:1.
• Other defoamers which may be used include, for example, the known silicones, such as available from Dow Chemicals.
• any chlorine bleach compound may be employed in the compositions of this invention, such as dichloroisocyanurate, dichlorodimethyl hydantoin, or chlorinated TSP, alkali metal or alkaline earth metal, e.g. potassium, lithium, magnesium and especially sodium hypochlorite is preferred.
• the composition should contain sufficient amount of chlorine bleach compound to provide 0.2 to 4.0% by weight of available chlorine, as determined, for example, by acidification and iodometric titration with thiosulfate.
• a solution containing 0.2 to 4.0% by weight of sodium hypochlorite contains or provides roughly the same percentage of available chlorine. 0.8 to 1.6% by weight of available chlorine is especially preferred.
• sodium hypochlorite (NaOCl) solution of from 11 to 13% available chlorine in amounts of 3 to 20%, preferably 7 to 12%, can be advantageously used.
• compositions of this invention are essentially total masking of any chlorine bleach odor which is characteristic of, for example, the prior known clay thickened products.
• any chlorine bleach odor which is characteristic of, for example, the prior known clay thickened products.
• the subject compositions can be blended with substantially lower amounts of fragrance, e.g. lemon oil fragrance, to achieve the same or superior sensation of smell for the consumer. For instance, as little as 0.05% of lemon fragrance will have the same effect as .12% in clay thickened products.
• fragrance does not adversely affect the stability criteria as previously defined, such as viscosity or phase stability, of the compositions.
• Detergent active material which are optionally useful herein should be low-foaming and stable in the presence of chlorine bleach, especially hypochlorite bleach, and for this purpose those of the organic anionic, nonionic, amine oxide, phosphine oxide, sulphoxide or betaine water dispersible surfactant types are preferred, wherein anionic surfactants are most preferred.
• Particularly preferred surfactants are the linear or branched alkali metal mono- and/or di-(C8-C14)alkyl diphenyl oxide mono- and/or di-sulphates, commercially available for example as DOWFAX (registered trademark) 3B-2 and DOWFAX 2A-1.
• the surfactant should be compatible with the other ingredients of the composition.
• Suitable organic anionic, non-soap surfactants include the primary alkyl sulphates, alkyl sulphonates, alkyl arylsulphonates and sec.-alkyl sulphates.
• Examples include sodium C10-C18 alkyl sulphates such as sodium dodecyl sulphate and sodium tallow alcohol sulphate; sodium C10-C18 alkane sulphonates such as sodium hexadecylbenzene sulphonates.
• the amine oxide surfactants are typically of the structure R2R1NO, in which each R represents a lower alkyl group, for instance, methyl, and R1 represents a long chain alkyl group having from 8 to 22 carbon atoms, for instance a lauryl, myristyl, palmityl or cetyl group.
• R1 represents a long chain alkyl group having from 8 to 22 carbon atoms, for instance a lauryl, myristyl, palmityl or cetyl group.
• a corresponding surfactant phosphine oxide R2R1PO or sulphoxide RR1SO can be employed.
• Betaine surfactants are typically of the structure R2R1N+R''COO-, in which each R represents a lower alkylene group having from 1 to 5 carbon atoms.
• these surfactants include lauryl-dimethylamine oxide, myristyldimethylamine oxide, the corresponding phosphine oxides and sulphoxides, and the corresponding betaines, including dodecyldimethylammonium acetate, tetradecyldiethylammonium pentanoate, hexadecyldimethylammonium hexanoate and the like.
• the alkyl groups in these surfactants should be linear, and such compounds are preferred.
• the chlorine bleach stable, water dispersible organic detergent-active material will normally be present in the composition in minor amounts, generally about 1% by weight of the composition, although smaller or larger amounts, such as up to 3%, such as from 0.1 to 3%, preferably from 0.1 to 2% by weight of the composition, may be used.
• Alkali metal (e.g. potassium or sodium) silicate which provides alkalinity and protection of hard surfaces, such as fine china glaze and pattern, is generally employed in an amount ranging from 5 to 20 weight percent, preferably 5 to 15 weight percent, more preferably 8 to 12 weight percent in the composition.
• the sodium silicate is generally added in the form of an aqueous solution, preferably having Na2O:SiO2 or K2O:SiO2 ratio of 1:1.3 to 1:2.8, especially preferably 1:2.0 to 1:2.6.
• alkali metal hydroxide and bleach are also often added in the form of a preliminary prepared aqueous dispersion or solution.
• the reference is to an active ingredient basis, i.e. does not include the aqueous carrier.
• the effectiveness of the liquid automatic dishwasher detergent compositions is related to the alkalinity, and particularly to moderate to high alkalinity levels. Accordingly, the compositions of this invention will have pH values of at least 9.5, preferably at least 11 to as high as 14, generally up to 13 or more, and, when added to the aqueous wash bath at a typical concentration level of 10 grams per liter, will provide a pH in the wash bath of at least 9, preferably at least about 10, such as 10.5, 11, 11.5 or 12 or more.
• the alkalinity will be achieved, in part, by the alkali metal ions contributed by the alkali metal detergent builder salts, e.g. sodium tripolyphosphate, and alkali metal silicate, however, it is usually necessary to include alkali metal hydroxide, e.g. NaOH or KOH, to achieve the desired high alkalinity. Amounts of alkali metal hydroxide in the range of from 1.2 to 8%, by weight of the composition will be sufficient to achieve the desired pH level.
• alkali metal hydroxide e.g. NaOH or KOH
• the pH of the composition during processing is highly important for product stability, e.g. viscosity, and bleach stability and phase stability.
• the amount of basic neutralizing agent, preferably NaOH should be sufficient to provide the neutralized thickening agent with a pH of at least 11, preferably at least 11.5.
• these high alkalinity levels should be maintained throughout the product formulation steps, namely, the pH value of at least 11, preferably at least 11.5, should be maintained during the successive additions of the other ingredients of the composition.
• alkali metal salts such as alkali metal carbonate may also be present in the compositions in minor amounts, for example from 0 to 9%, preferably 0 to 6%, by weight of the composition to buffer the pH of the composition.
• inorganic thickening agents such as a finely divided silica, eg Cab-O-Sil from the Cabot Corp. can be used in amounts of 0 to about 8 weight %.
• a relatively low molecular weight, non-crosslinked polyacrylic acid such as the Polymer A3 sold by Rohm and Haas Co., which has a molecular weight of 190,000.
• the low molecular weight polyacrylic acids can provide additional thickening characteristics, but are also introduced for their ability to function as a builder or chelating agent.
• the low molecular weight polyacrylic acids can contribute to reduced spotting or streaking and reduced filming on dishes, glassware, pots, pans and other utensils and appliances.
• a suitable molecular weight range for the non-crosslinked polyacrylic acid is from 150,000 to 300,000, preferably 150,000 to 250,000, more preferably from 175,000 to 250,000.
• the non-crosslinked polyacrylic acid can be used in amounts up to 10% by weight, preferably from 0 to 9% by weight, more preferably 1 to 8% by weight of the composition.
• compositions may be included in small amounts, generally less than 3 weight percent, such as perfume, preservatives, dyestuffs and pigments and the like, all of course being stable to chlorine bleach compound and high alkalinity.
• perfume preservatives, dyestuffs and pigments and the like
• chlorinated phthalocyanines and polysulphides of aluminosilicate which provide, respectively, pleasing green and blue tints.
• the bleach stable mixed dyes C.I. Direct Yellow 28 (C.I. 19555) or C.I. Direct Yellow 29 (C.I. 19556) can be added to the compositions.
• TiO2 may be employed for whitening or neutralizing off-shades.
• the amount of water contained in these compositions should, of course, be neither so high as to produce unduly low viscosity and fluidity, nor so low as to produce unduly high viscosity and low flowability.
• the amount of water is readily determined by routine experimentation and generally will range from 30 to 75 weight percent, preferably 35 to 65 weight percent, and most preferably at least 98 weight percent. At least 90 weight present more preferably at least 95 weight percent of the water present in the composition is bound to the high molecular weight polycarboxylate polymer. Preferably, the water should also be deionized or softened.
• compositions are prepared by forming a dispersion of the polycarboxylate type thickeners in heated water, e.g.
• processing is continued by introducing, while continuing mixing, the detergent builder salts, alkali metal silicates, chlorine bleach compound and remaining detergent additives, including any previously unused alkali metal hydroxide, if any, other than the surface-active compounds.
• All of the additional ingredients can be added simultaneously or sequentially, with mixing continued for from 2 to 10 minutes for each ingredient, although it is not necessary to complete the addition of one ingredient before beginning to add the next ingredient. Furthermore, one or more of these ingredients can be divided into portions and added at different times. These mixing steps should also be performed under moderate to high shear rates to achieve complete and uniform mixing. These additional ingredient mixing steps may be carried out at room temperature, but preferably the elevated temperature of the thickener slurry is maintained. The composition may be allowed to age, if necessary, to cause unintentionally dissolved or dispersed air to dissipate out of the composition.
• the remaining surface active ingredients including the anti-foaming agent, organic detergent compound, and the R1C00X organic compound as previously defined are post-added to the previously formed mixture in the form of an aqueous emulsion (using from 1 to 10%, preferably from 2 to 4% of the total water added to the composition other than water added as carrier for other ingredients or water of hydration) which is pre-heated to a sufficient temperature (120° to 170°F) (49 to 77°C) to form a milky emulsion.
• an aqueous emulsion using from 1 to 10%, preferably from 2 to 4% of the total water added to the composition other than water added as carrier for other ingredients or water of hydration
• the order of addition of the surface active ingredients should be less important.
• the thickened linear viscoelastic aqueous automatic dishwasher detergent composition of this invention includes, on a weight basis:
• compositions will be supplied to the consumer in suitable dispenser containers preferably formed of molded plastic, especially polyolefin plastic, and most preferably polyethylene, for which the invention compositions appear to have particularly favorable slip characteristics.
• the compositions of this invention may also be characterized as pseudoplastic gels which are typically near the borderline between liquid and solid viscoelastic gel, depending, for example, on the amounts and types of the polymeric thickeners.
• the invention compositions can be readily poured from their containers at a rate of at least 225 grams/minute through a 0.375 inch (8.45 mms) opening, when the container is aligned parallel to a vertical axis and without any shaking or squeezing, i.e. have a sufficiently low yield stress value to flow under their own weight (gravity), although squeezable containers are often convenient and accepted by the consumer for gel-like products.
• liquid aqueous linear viscoelastic automatic dishwasher compositions of this invention are readily employed in known manner for washing dishes, other kitchen utensils and the like in an automatic dishwasher, provided with a suitable detergent dispenser, in an aqueous wash bath containing an effective amount of the composition, generally sufficient to fill or partially fill the automatic dispenser cup of the particular machine being used.
• the invention also provides a method for cleaning dishware in an automatic dishwashing machine with an aqueous wash bath containing an effective amount of the liquid linear viscoelastic automatic dishwasher detergent composition as described above.
• the composition can be readily poured from the polyethylene container with little or no squeezing or shaking into the dispensing cup of the automatic dishwashing machine and will be sufficiently viscous and cohesive to remain securely within the dispensing cup until shear forces are again applied thereto, such as by the water spray from the dishwashing machine.
• Formulations A - F are prepared by first forming a uniform dispersion of the Carbopol thickeners in about 97% of the water of the total formula water.
• the Carbopols are slowly added by sprinkling them into the vortex of previously colored deionized water preheated to a temperature of 105°F (41°C) using a mixer equipped with a Premier blade, with agitation set at a medium shear rate, as recommended by the manufacturer. After mixing for about 15 minutes, the dispersion is then neutralized by addition, under the same mixing, of the caustic soda (50% NaOH) component until a thickened product of gel-like consistency is formed (about 10 minutes).
• the caustic soda 50% NaOH
• the silicate sodium tripolyphosphate (NaTPP), the surfactant emulsion (described below), bleach and color, are added sequentially, in the order stated, with the mixing continued at medium shear for several minutes before adding the next ingredient.
• the surfactant emulsion at 160°F) (71°C)
• the mixture is cooled to from 90°-95°F (32-35°C) before the bleach is added.
• the surfactant emulsion of the phosphate anti-foaming agent (LPKN), detergent (Dowfax 3B2) and the organic compound of the formula R1C00X such as sodium benzoate is prepared by adding these ingredients to the remaining 3% of water and heating the resulting mixture to a temperature in the range of 160°F (71°C).
• the Polymer A3 may be added at this stage.
• Ease of dispensability of the formulations was evaluated by the following general procedure.
• a 64 oz. (1.8 kilograms) polyethylene bottle with a cap orifice size of 0.375" (8.45 mms diameter) was filled with 300 gms of test sample and left on the bench top for about 10 minutes.
• the bottle was then suspended perpendicular to the plane of the bench with the cap facing downward.
• the orifice cap was then opened and the product was allowed to drain under gravitational force.
• the flow rate i.e., amount of product dispensed/minute
• the results are summarized in Table III.
• the rate of dispensability of the present invention (B-H) is superior to the prior art example A.
• TI thixotropic index

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• 1992
  • 1992-04-15 NZ NZ24238292A patent/NZ242382A/en unknown
  • 1992-04-20 GR GR920100158A patent/GR1001216B/el unknown
  • 1992-04-20 PT PT100403A patent/PT100403A/pt not_active Application Discontinuation
  • 1992-04-21 NO NO92921533A patent/NO921533L/no unknown
  • 1992-04-21 AU AU15019/92A patent/AU1501992A/en not_active Abandoned
  • 1992-04-21 FI FI921760A patent/FI921760A/fi not_active Application Discontinuation
  • 1992-04-21 CA CA002066536A patent/CA2066536A1/en not_active Abandoned
  • 1992-04-22 IE IE127492A patent/IE921274A1/en unknown
  • 1992-04-22 EP EP92303608A patent/EP0523826A1/de not_active Withdrawn

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