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
  • C11D1/02—Anionic compounds
  • C11D1/04—Carboxylic acids or 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
  • 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
  • C11D3/2079—Monocarboxylic 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
• • 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
  • C11D3/395—Bleaching agents
  • C11D3/3956—Liquid compositions

Definitions

• Liquid automatic dishwashing detergent compositions have recently received much attention, and the aqueous products have achieved commercial popularity.
• U.S. Patent 4,836,948 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 cross-linked polyacrylic acid.
• the compositions of this patent also, however, require a trivalent metal containing material, especially an aluminum containing material such as alumina.
• the compositions may further include 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, which do not affect the viscosity of the compositions in thickened aqueous automatic dishwasher detergent compositions.
• the thickeners for these compositions may be a high molecular weight polycarboxylate polymer, such as those sold under the Carbopol trade name, and specific 600 and 900 series resins are mentioned. It is also disclosed that the compositions include entrained gas, e.g. air bubbles to further ensure stability.
• the specific gravity of the composition was stated to be 1.32 g/cm3.
• the compositions are not described as being linear viscoelastic and as exemplified do not include any potassium salts.
• the finished product not only may be perceived as unaesthetic but, more importantly, the product viscosity is often lowered which in turn may lead to cup leakage and corresponding degradation in cleaning performance.
• the present invention related to an improved aqueous liquid automatic dishwashing detergent composition (abbreviated LADD) which is characterized by its linear viscoelastic behavior, excellent stability against phase separation, excellent stability against settling of dissolved or suspended particles under high and low temperature conditions, low levels of bottle residue, relatively high bulk density, substantial absence of loosely bound water, superior aesthetics, improved optical properties, freedom from fish-eyes, absence of crystal formation and growth, and resistance to cup leakage of less than 10 wt%.
• LADD aqueous liquid automatic dishwashing detergent composition
• the present invention relates to an automatic dishwashing composition which contains a cross-linked, methyl vinyl ether/maleic anhydride polymeric thickening agent (referred to as cross-linked Gantrez) that is exceptionally stable to the high bleach, salt, and alkali levels found in automatic dishwashing detergent.
• the composition formed is temperature-stable. Furthermore, by controlling the conditions of mixing the ingredients of the compositions, and by controlling the method of dispersion, and by controlling the pH and temperature of the aqueous solution of the polymeric thickener, the formation of fish-eyes and loss of viscosity with time can be minimized.
• a dilute solution (0.05%) of cross-linked Gantrez shows a lower surface tension, by 4 dynes/cm, than a solution of Carbopol 614 under the same circumstances.
• these groups do not contribute to loss of available chlorine, but rather compositions containing them show the same chlorine stability as those without.
• the present invention provides an improved linear viscoelastic aqueous liquid automatic dishwashing detergent composition
• water up to about 2% by weight of long chain fatty acid or salt thereof; from 0 to 5% by weight of low foaming, chlorine bleach stable surfactant; from 0 to 3% by weight of a chlorine bleach-stable foam depressant; from about 10 to 35% by weight of alkali metal detergent builder salt; from 0 to 20% by weight of a chlorine bleach compound; and from .1 to 5% by weight of a cross-linked polymeric thickening agent, wherein the compositions preferably have a bulk density of from 1.28 g/cm3 to 1.42 g/cm3.
• the linear viscoelastic aqueous LADD comprises, approximately, by weight,
• 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: 1) improved optical properties, 2) physical stability such as manifested by little or no phase separation, solid settling or viscosity change over time, 3) little or no settling and/or viscosity change resulting from temperature variations, 4) low bottle residue, 5) low cup leakage of less than 10 wt%, 6) high cleaning performance, e.g. low spotting and filming, low dirt residue, 7) consistency in product characteristics performance, 8) superior aesthetics, 9) easier manufacturing process conditions than compositions made with Carbopol resins, and 10) improved biodegradability. These characteristics are believed to be attributable to several interrelated factors such as low undissolved particulate content, product density and linear viscoelastic rheology.
• compositional components and processing conditions of the formulations namely, (1) the inclusion of a cross-linked polymeric thickening agent that is stable to alkali, bleach and salt, in an amount effective for thickening and that has a high water absorption capacity, exemplified by a copolymer of methyl vinyl ether/maleic anhydride which is cross-linked with a diene such as Octadiene (2) inclusion of a physical stabilizing amount of a long chain fatty acid or salt thereof, and (3) a product bulk density of at least 1.28 g/cc, especially at least 1.32 g/cc and (4) maintaining the pH of the neutralized polymeric thickener at a pH of at least 11, more preferably at least 11.5.
• a cross-linked polymeric thickening agent that is stable to alkali, bleach and salt, in an amount effective for thickening and that has a high water absorption capacity
• a copolymer of methyl vinyl ether/maleic anhydride which is cross-linked with a diene such
• the linear viscoelastic aqueous liquid automatic dishwashing 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 I: 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 I:
• compositions of this invention are further characterized by their low bottle residue and cup leakage.
• bottle residues under the usual use conditions, will be no more than about 6 to 8%, preferably no more than about 4 to 5%, of the original bottle contents, on a weight basis.
• 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 purposes of this invention, if over the strain range of 0-50% the elastic modulus G′ has a minimum value of 100 dynes/sq.cm., preferably at least 250 dynes/sq.cm., and varies less than about 500 dynes/sq.cm., preferably less than 300 dynes/sq.cm., especially 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 x 100%.
• 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 compositions to cause it to flow, the surrounding portions will follow.
• the 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 means for further improving the structuring of the gel formulations of the instant invention in order to obtain improved viscosity as well as G′ and G ⁇ values is to form an aqueous polymeric solution of a crosslinked methyl vinyl ether/maleic anhydride copolymer which functions as a thickening agent at about 75°C to about 80°C with mixing and subsequently with mixing neutralizing the carboxylic acid groups from the anhydride by the addition of an excess basic material such as caustic soda to form an alkali metal neutralized crosslinked copolymer having a molecular weight of about 60,000 to about 10,000,000.
• aqueous solution of the alkali metal neutralized crosslinked copolymer containing excess caustic soda is added with mixing a fatty acid or a metal salt of a fatty acid.
• the fatty acid reacts "in situ" with the excess caustic soda to form an alkali metal salt of the fatty acid.
• the alkali metal crosslinked copolymer in combination with the metal salt of the fatty acid provides improved G′ and G ⁇ values as well as improved viscosification of the aqueous polymeric solution having a pH of about 7 to 14 as compared to the use of the alkali metal neutralized crosslinked copolymer alone as a viscosification agent.
• the improvement in viscosification results from an increase in solid content and from the association of the alkali metal salt of the fatty acid and the alkali metal neutralized crosslinked copolymer in the water, wherein the anionic groups of the fatty acid and the anionic groups of the copolymer are repulsive to each other thereby causing an uncoiling of the polymeric chain of the alkali metal neutralized copolmer which provides a further building of the polymeric structure within the water.
• water and metal salt of the fatty acid can be added detergent builder salts, silicates, surfacants, foam depressants and bleachants without significantly damaging the polymeric structure to form a gel like automatic dishwashing composition.
• Other commercial and industrial compositions can be formed for a variety of applications such as toothpastes, creams or a toothpaste gels, cosmetics, fabric cleaners, shampoos, floor cleaners, cleaning paste, tile cleaners, thickened bleach compositions, ointments, oven cleaners, pharmaceutical suspensions, concentrated coal slurries, oil drilling muds, cleaning prestoppers and aqueous based paints.
• compositions can be formulated by adding the appropriate chemicals to the aqueous polymeric solution of alkali metal neutralized copolymer, caustic soda and a metal salt of a fatty acid to form the desired composition.
• the polymeric aqueous solution of water, caustic soda, alkali metal neutralized copolymer and the metal salt of the fatty acid has a complex viscosity at room temperature at 10 radians/second of about 2 to about 800 dyne seconds/sq.cm., more preferably about 20 to about 700 dyne seconds/sq.cm..
• the polymeric solution comprises about 0.02 to about 2.0 weight %, more preferably 0.04 to 1.0 weight % of a metal salt of a fatty acid, about 0.1 to about 4.0 weight %, more preferably 0.2 to about 3.0 weight % of an alkali metal neutralized crosslinked copolymer such as a crosslinked copolymer of methyl vinyl ether/maleic anhydride and water, wherein the aqueous polymeric solution has a G′ value of at least about 80 dynes/sq. cm at a frequency of 10 radians/second, a G ⁇ value of at least about 10 dynes/sq. cm at a frequency of 10 radians/second, a ratio of G ⁇ /G′ is less than 1 and G′ is substantial constant over a frequency range of 0.01 to 50.0 radians/second.
• the polymeric solution has a G′ value of at least about 80 dynes/sq. cm. at a frequency of 10 radians/second and the G ⁇ valve is at least about 10 dynes/sq. cm at a frequency of 10 radians/second, wherein G′ is substantially constant over a frequency range of 0.01 to 50 radians/second and a ratio of G ⁇ /G′ is less than 1 and a yield stress of at least about 2, more preferably about 2 to about 1200 dynes/sq. cm.
• the polymeric solution will be a gel which can function as a suspension medium for a plurality of solid particles, immiscible liquid droplets or gaseous bubbles.
• the solid particles, liquid droplets or gaseous bubbles can be inorganic, organic or polymeric.
• the solid material, liquid droplets or gaseous bubbles which are not soluble in the water phase, should not decompose in an aqueous solution or react with the carboxylic groups of the copolymer or the carboxylate groups of the fatty acid.
• the concentration of the solid particles, liquid droplets or gaseous bubbles in the suspension medium is about 0.1 to about 70 weight percent, more preferably about 1 to about 50 weight %.
• the surface active ingredients are post-added 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 higher fatty acid or salt thereof as a physical stabilizer.
• anti-foaming agent e.g. phosphate ester
• higher fatty acid or salt thereof e.g. phosphate ester
• Certain classes of polymers can be lightly cross-linked to give gels in aqueous system. These gels have strong elastic character, are able to suspend solids, resist syneresis on aging, and have other desirable physical properties for use in consumer products. Desirable properties for an automatic dishwasher detergent include: 1) ease of dispensing from a bottle (easily shear-thinned) 2) high yield value (so the product will not run out of the detergent dispenser cup in the door of the dishwasher 3) good maintenance of viscosity on aging, especially in the presence of a high concentration of inorganic salts and 4) resistance to oxidation by components of the formula containing available chlorine.
• the preferred polymers to impart these properties are lightly cross-linked so that they tend to swell and form strong three-dimensional networks in aqueous system.
• One such class of bleach stable polymers is based on an alkyl vinyl ether/maleic anhydride or an alkyl vinyl ether/substituted maleic anhydride such as a methyl vinyl ether/maleic anhydride copolymers and terpolymers.
• useful polymers are: methyl vinyl ether, maleic anhydride, acrylic acid, cross-linked; methyl vinyl ether, maleic anhydride, vinyl pyrrolidone, cross-linked; and methyl vinyl ether, maleic anhydride, isobutene, cross-linked.
• the cross-linking agent is essential to establish the kind of polymer network useful in this invention.
• the cross-linking agent can be any hydrocarbon with a chain length of four or more carbon atom containing at least two carbon-carbon double bonds.
• the cross-linking agent is mainly a hydrocarbon with optional halogen and oxygen-containing substituents and linkages such as ester, ether and OH groups. These cross-linking agents can vary in amount from 0.01 to 30% by weight of the total quantity of polymer used. Examples of cross-linking agents are 1,7-Octadiene, 1,9 Decadiene, non-terminal dienes, Divinyl Glycol, Butane Divinylether, polyallyl pentaerythritol and polyallyl sucrose. Cross-linking can also be achieved through the maleic anhydride after the polymer is formed, via ester or amide formation using polyols and polyamines such as 1,4 butane diol and polyethylene glycols.
• the most useful polymers of these inventions are the Gantrez AN cross-linked with aliphatic dienes such as 1,7 octadiene and 1,9 decadiene.
• Gantrez AN polymers cross-linked from .01 to 10% by weight of 1,7 octadiene were shaken overnight in order to hydrolyze the maleic anhydride ring.
• the polymer solutions were neutralized to pH 7 to fully ionize the carboxyl groups. The results show that 5% by weight of cross-linking agent is necessary before a gel is formed. If Gantrez AN is cross-linked with 1,9 decadiene then a gel is formed at 3-4% cross-linking.
• cross-linking causes the formation of a polymer that disperses in water to form a gel with a yield point.
• Table II gives typical yield points for the polymer cross-linked with 1,9 decadiene.
• the bleach stable copolymer of the instant invention is wherein x and y are about 50 moles percent, R1 represents a hydrogen atom or an alkyl group having about 1 to about 10 carbon atoms, more preferably about 1 to about 6, R4 represents an alkyl group having about 1 to about 10 carbon atoms, more preferably about 1 to 6 carbon atoms, R2 represents a hydrogen atom or a halogen atom such as bromo or chloro or alkaryl group such as benzyl, an alkyl aliphatic group having about 1 to 10 carbon atoms such as methyl or propyl, an aryl group such as phyenyl or p-methylphenyl, or a cycloaliphatic group having about 1 to 10 carbon atoms such as cyclohexyl, wherein maleic an hydride is preferred and vinyl methyl ether is preferred.
• the maleic anhydride ring opens to form wherein Y+ a metal on selected from the group consisting of IA, IIA, IIIA, IB, IIB and IIIB of the Periodic Table of Elements.
• the aqueous solution of the metal neutralized alkyl vinyl ether/maleic acid copolymer forms a gel structure having a yield point, Pa of at leat 30 Pa at a concentration of polymer of 0.125 weight percent.
• the copolymer is preferably cross-linked with 0.5 to 20.0 wt% of a diene monomer having about 6 to 20 carbon atoms, more preferably 7 to 16 and most preferably 8 to 12, wherein preferred diene monomers are 1,7 Octadiene and 1,9 decadiene.
• diene monomers having about 6 to 20 carbon atoms, more preferably 7 to 16 and most preferably 8 to 12, wherein preferred diene monomers are 1,7 Octadiene and 1,9 decadiene.
• the amount of the cross-linked polymeric thickening agent or other high molecular weight, hydrophilic cross-linked polycarboxylate thickening agent to impart the desired rheological property of linear viscoelasticity will generally be in the range of from 1.5 to 5%, preferably from .5 to 2.5, 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 inorganic detergent builder salts that are employed in the compositions of the instant invention are selected from the group consisting of sodium and potassium salts of polyphosphates, orthophosphates, carbonates, bicarbonates, sesquicarbonates and borates and aluminosilicates, wherein sodium tripolyphosphate (NaTPP) and potassium tripolypolyphosphate (KTPP) are especially preferred.
• NaTPP sodium tripolyphosphate
• KTPP potassium tripolypolyphosphate
• Organic detergent builders maybe used alone or in combination with the inorganic builder salts, wherein the organic builder salts are selected from the group consisting of sodium and potassium salts of citrates, nitrilotriacetates, oxydiacetates, carboxymethoxysuccinates, tetracarboxylates, and starch.
• the detergent builder salts will be preferably comprised of mixtures of at least potassium tripolyphosphate (KTPP) and sodium tripolyphosphate (NaTPP). Typical ratios (based upon weight) of KTPP to NaTPP are from about 1.4:1 to 10:1, especially from about 2:1 to 8:1.
• 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 15 to 30% by weight of the composition. Of this total amount of the detergent builders at least 50% by weight (preferably at least 8% by weight of the composition) will be KTPP and preferably at least 5% by weight (preferably at least 2% by weight of the composition) will be NaTPP.
• the alkali metal detergent builder salt will be comprised of from 65 to 95% by weight of KTPP, especially 75 to 90% of KTPP and from 5 to 35% of NaTPP, especially 10 to 25% of NaTPP.
• the amount of KTPP will be in the range of from 8 to 25% by weight, preferably 15 to 22%
• the amount of NaTPP will be in the range of from 2 to 10% by weight, preferably 3 to 8%.
• 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 and, in any case, preferably in amounts to maintain the K/Na ratios to within the above described range.
• the linear viscoelastic compositions of this invention may, and preferably will, contain a small, but effective, amount of a long chain fatty acid or monovalent or polyvalent salt thereof to stabilize the composition.
• a long chain fatty acid or monovalent or polyvalent salt thereof may function as a hydrogen bonding agent or cross -linking agent for the polymeric thickener.
• the preferred long chain fatty acids are the higher aliphatic fatty acids having from 10 to 50 carbon atoms, more preferably from about 12 to 40 carbon atoms, and especially preferably from 14 to 40 carbon atoms, inclusive of the carbon atom of the carboxyl group of the fatty acid.
• the aliphatic radical may be saturated or unsaturated and may be straight or branched, wherein the aliphatic radical can have functional groups can be attached to the aliphatic radical, wherein the functional groups are selected from the group consisting of hydroxyl, ester, tertiary amines and dialkyl substituted amide groups.
• Straight chain saturated fatty acids are preferred.
• Mixtures of fatty acids may be used, such as those derived from natural sources, such as tallow fatty acid, coco fatty acid, soya fatty acid, etc., or from synthetic sources available from industrial manufacturing processes.
• examples of the fatty acids include, for example, decanoic acid, dodecanoic acid, palmitic acid, myristic acid, stearic acid, isostearic acid, behenic acid, oleic acid, eicosanoic acid, tallow fatty acid, coco fatty acid, soya fatty acid, mixtures of these acids, etc.
• Stearic acid and mixed fatty acids e.g. stearic acid/palmitic acid, are preferred.
• phase stability particularly under elevated temperature storage conditions, and maintenance of product viscosity levels can be obtained by using longer chain length fatty acids in the range of from C18 to C40.
• Either individual or mixtures of these longer chain length fatty acids can be used, however, the average chain length should be in the range of from 20 to 32 carbon atoms, especially 24 to 30 carbon atoms and mixture of fatty acids encompassing this range are preferred.
• Suitable mixed fatty acids are commercially available, for instance those sold under the trade name Syncrowax by Croda.
• the free acid form of the fatty acid When used directly it will generally associate with the potassium and sodium ions in the aqueous phase to form the corresponding alkali metal fatty acid soap.
• the fatty acid salts may be directly added to the composition as sodium salt or potassium salt, or as a polyvalent metal salt, although the alkali metal salts of the fatty acids are preferred fatty acid salts.
• the preferred polyvalent metals are the di- and trivalent metals of Groups IIA, IIB and IIIB, such as magnesium, calcium, aluminum and zinc, although other polyvalent metals, including those of Groups IIIA, IVA, VA, IB, IVB, VB, VIB, VIIB and VIII of the Periodic Table of the Elements can also be used.
• such other polyvalent metals include Ti, Zr, V, Nb, Mn, Fe, Co, Ni, Cd, Sn, Sb, Bi, etc.
• the metals may be present in the divalent to pentavalent state.
• the metal salts are used in their higher oxidation states.
• the metal salt should be selected by taking into consideration the toxicity of the metal.
• the alkali metal and calcium and magnesium salts are especially preferred since they are generally safe food additives.
• the amount of the fatty acid or fatty acid salt stabilizer to achieve the desired enhancement of physical stability will depend on such factors as the nature of the fatty acid or its salt, the nature and amount of the thickening agent, detergent active compound, inorganic salts, other ingredients, as well as the anticipated storage and shipping conditions.
• amounts of the fatty acid or fatty acid salt stabilizing agents in the range of from 0.02 to 2% by weight, preferably 0.04 to 1%, more preferably from 0.06 to 0.8%, most preferably from 0.08 to 0.4%, provide a long term stability and absence of phase separation upon standing or during transport at both low and elevated temperatures as are required for a commercially acceptable product.
• proportions and types of fatty acid physical stabilizers and polycarboxylate thickening agents the addition of the fatty acid or salt not only increases physical stability, but also provides a simultaneous increase in apparent viscosity. From 0.08-0.4 weight percent of the metal salt of the fatty acid salt or the fatty acid and from 0.4-1.5 weight percent of the polymeric thickening agent is usually sufficient to provide these simultaneous benefits and, therefore, the use of these ingredients in these amounts is most preferred.
• the fatty acid or salt is preferably post-added to the formulation, preferably together with the other surface active ingredients, including detergent active compound and anti-foaming agent, when present.
• These surface active ingredients are preferably added as an emulsion in water, wherein the emulsified oily or fatty materials are finely and homogeneously dispersed throughout the aqueous phase.
• the emulsion or preheat the water
• an elevated temperature near the melting temperature of the fatty acid or its salt.
• stearic acid having a melting point of 68°-69°C a temperature in the range of between 50°C and 71°C will be used.
• an elevated temperature of 35° to 50°C can be used.
• the fatty acid or salt and other surface active ingredients can be more readily and uniformly dispersed (emulsified) in the form of fine droplets throughout the composition.
• 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 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 alkyl or ethoxylated 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, 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 diethers 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 0.05 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 5:1 to 1:1.
• many of the stabilizing salts, such as the stearate salts, when included, are also effective as foam depressants.
• any chlorine bleach compound may be employed in the compositions of this invention, such as dichloroisocyanurate, dichloro-dimethyl 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. 0.8 to 1.6% by weight of available chlorine is especially preferred.
• sodium hypochlorite (NaOCl) solution of from about 11 to about 13% available chlorine in amounts of 3 to 20%, preferably 7 to 12%, can be advantageously used.
• Detergent active material useful herein should be low-foaming and stable in the presence of chlorine bleach, especially hypochlorite bleach.
• those of the organic aromatic anionic, organic aliphatic 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.
• surfactant should be compatible with the other ingredients of the composition.
• suitable organic anionic, non-soap surfactants include the primary alkylsulphates, alkylsulphonates, alkylarylsulphonates and sec.- alkylsulphates. Examples include sodium C10-C18 alkylsulphates such as sodium dodecylsulphate and sodium tallow alcoholsulphate; sodium C10-C18 alkanesulphonates such as sodium hexadecylbenzenesulphonates. The corresponding potassium salts may also be employed.
• the amine oxide surfactants are typically of the structure R2R′NO, in which each R represents a lower alkyl group, for instance, methyl, and R′ represents a long chain alkyl group having from 8 to 22 carbon atoms, for instance a lauryl, myristyl, palmityl or cetyl group.
• R′ 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 R2R′PO or sulphoxide RR′SO can be employed.
• Betaine surfactants are typically of the structure R2R′N+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 or water soluble organic detergent-active material will normally be present in minor amounts, generally 1% by weight of the composition, although smaller or larger amounts, such as up to 5%, such as from 0 to 5%, preferably from 0.3 or 0.4 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 or potassium 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 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, potassium 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.
• alkali metal hydroxide e.g. NaOH or KOH
• Amounts of alkali metal hydroxide in the range of from 0 to 8%, preferably from 1 to 6%, more preferably from 1.2 to 4%, by weight of the composition will be sufficient to achieve the desired pH level and/or to adjust the K/Na weight ratio.
• alkali metal salts such as alkali metal carbonate may also be present in the compositions in minor amounts, for example from 0 to 4%, preferably 0 to 2%, by weight of the composition.
• the low polyacrylic acids can provide additional thickening characteristics but are primarily introduced for their ability to function as a builder or chelating agent. In this capacity, 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 ranges for the non-crosslinked polyacrylic acid is from 800 to 200,000, preferably 1000 to 150,000, and more preferably from 2,000 to 100,000.
• the non-crosslinked polyacrylic acid can be used in amounts up to 10% by weight, preferably from 0 to 8% by weight, especially 2 to 6% by weight of the composition.
• compositions may be included in small amounts, generally less than 3 weight percent, such as perfume, hydrotropic agents such as sodium benzene sulfonate, toluene sulfonate, xylene sulfonate and cumene sulfonate, preservatives, dyestuffs and pigments and the like, all of course being stable to chlorine bleach compound and high alkalinity.
• hydrotropic agents such as sodium benzene sulfonate, toluene sulfonate, xylene sulfonate and cumene sulfonate
• preservatives dyestuffs and pigments and the like
• dyestuffs and pigments and the like all of course being stable to chlorine bleach compound and high alkalinity.
• 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
• incorporation of small amounts of finely divided air bubbles can be incorporated to adjust the visual appearance, product density and flowability.
• the incorporated air bubbles should be finely divided, such as up to about 100 microns in diameter, preferably from about 20 to 40 microns in diameter.
• Other inert gases can also be used, such as nitrogen, helium, argon, etc.
• 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, linear viscoelastic properties in either case being diminished or destroyed by increasing Tan ⁇ .
• 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.
• the water should also be deionized or softened.
• 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.
• 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 (nonthixotropic) which are typically near the borderline between liquid and solid viscoelastic gel, depending, for example, on the amount of the polymeric thickener.
• the invention compositions can be readily poured from their containers 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.
• a typical synthesis of cross-linked Gantrez is set forth as follows: In a one liter pressure reactor charge the following (all parts by weight): 404.4 parts cyclohexane, 269.6 parts ethyl acetate, 6 parts 1,7 octadiene. The initiator t-butylperoxypivalate, is added at 58°C in three increments of 0.1 part each. Each portion is added all at once, not over a period of time. Initiator is added as 0.1 part at times: 0, 60, and 120 minutes of the reaction. Seventy-five parts of molten maleic anhydride and 49.0 parts of methyl vinyl ether are mixed together and added to the reaction vessel at 58°C and 65 psi.
• Formulations A-F were prepared by first forming a uniform dispersion of the crosslinked Gantrez AN polymer from Example 1 in about 90% of the water to be added as water in the formula.
• the Gantrez AN was added to deionized water with agitation.
• the dispersion was then neutralized by addition of the caustic soda (50% NaOH) component until a thickened product of gel-like consistency was formed.
• the silicate sodium tripolyphosphate (NaTPP), potassium tripolyphosphate (KTPP), the surfactant emulsion (described below), bleach and color, were 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 was cooled to 90°F (32°C) from 90°-110°F (32-43°C) before the bleach was added.
• the surfactant emulsion of the phosphate anti-foaming agent (LPKN), stearic acid or fatty acid mixture and detergent (Dowfax 3B2) was prepared separately by adding these ingredients to the remaining 3% of water (that was not used to disperse the polymer) and heating the resulting mixture to a temperature of about 160°F (71°C).
• Table VI contains a summary of available chlorine data of LADD with cross-linked Gantrez.
• Formula E (most stable against separation per wt of polymer used) exhibits only a 20% loss in available chlorine after 6 weeks at room temperature, and a 30% loss after 3 weeks at 100°F (38°C).
• Viscosity measurements of the various LADD formulas are summarized in Table VII as a function of time. Viscosity of the cross-linked Gantrez formulas show little or no viscosity loss experienced as a function of aging.
• Table VIII contains data on the amount of bottle residue obtained for liquid automatic dishwashing detergent with cross-linked Gantrez and two different versions of a standard commercial automatic dishwashing detergent.
• the residue left for samples C and D is considerably more (2 times and 1.4 times, respectively) than that of the cross-linked Gantrez when no force is used to dispense the product.
• the method for determining the bottle residue was to put test samples in 50 oz Polyethylene bottles. All samples were shaken before being left to equilibrate overnight. Eighty grams is dispensed repeatedly with 2 min rests between doses. The sample is capped and stood upright during the rest periods. No excess force is used until the point when no more product can be dispensed easily. At this time the bottle is shaken and the product is forced out. Grams of bottle residue is reported a) without force and b) with force.

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• 1992
  • 1992-04-22 AT AT92303607T patent/ATE165112T1/de not_active IP Right Cessation
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