EP1115838A1 - Compositions de detergent granulaires presentant des profils de solubilite ameliores - Google Patents

Compositions de detergent granulaires presentant des profils de solubilite ameliores

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Publication number
EP1115838A1
EP1115838A1 EP99949920A EP99949920A EP1115838A1 EP 1115838 A1 EP1115838 A1 EP 1115838A1 EP 99949920 A EP99949920 A EP 99949920A EP 99949920 A EP99949920 A EP 99949920A EP 1115838 A1 EP1115838 A1 EP 1115838A1
Authority
EP
European Patent Office
Prior art keywords
less
value
detergent
time
surfactant
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP99949920A
Other languages
German (de)
English (en)
Inventor
Scott William Capeci
Kevin Todd Norwood
Paul R. Mort, Iii
Kristin Nicole Perkis
George Burgess
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Procter and Gamble Co
Original Assignee
Procter and Gamble Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Procter and Gamble Co filed Critical Procter and Gamble Co
Priority claimed from PCT/US1999/022396 external-priority patent/WO2000018878A1/fr
Publication of EP1115838A1 publication Critical patent/EP1115838A1/fr
Withdrawn legal-status Critical Current

Links

Definitions

  • the present invention relates to granular detergent compositions having improved solubility profiles and in particular, to granular detergent compositions that match or exceed the cleaning performance of liquid detergents while avoiding the negative attributes associated with granular products.
  • this clumping phenomenon can contribute to the incomplete dispensing of detergent in washing machines equipped with dispenser drawers or in other dispensing devices, such as a granulette.
  • the undesired result is undissolved detergent residue in the dispensing device.
  • inorganic salts In addition to the viscous surfactant "bridging" effect, inorganic salts have a tendency to hydrate which can also cause “bridging” of particles which linked together via hydration. In particular, inorganic salts hydrate with one another to form a cage structure which exhibits poor dissolution and ultimately ends up as a "clump" after the washing cycle. It would therefore be desirable to have a detergent composition which does not experience the dissolution problems identified above so as to result in improved cleaning performance.
  • a granular detergent composition having an average bulk density of at least about 400 g/L and characterized by a rate of dispersion as defined by the equation:
  • R is the residual undispersedv detergent at any point in time
  • t is any single point in time
  • m is a stretching exponent having a value of less than about 2
  • DT is dispersion time having a value of less than about 0.5 and is the time of the wash cycle.
  • at least 90% of the insoluble particulate residues of said granular detergent composition having a particles size of less than 15 ⁇ m are provided and/or the detergent composition has a rate of dissolution as defined by the equation:
  • U is the fraction of undissolved surfactant at any point in time
  • t is any single point in time
  • n is a stretching exponent having a value of less than about 2
  • RT dissolution time having a value of less than about 0.5
  • t ⁇ ash is the time of the wash cycle.
  • particles means the entire size range of a detergent final product or component or the entire size range of discrete particles, agglomerates, or granules in a final detergent product or component admixture. It specifically does not refer to a size fraction (i.e., representing less than 100% of the entire size range) of any of these types of particles unless the size fraction represents 100% of a discrete particle in an admixture of particles. For each type of particle component in an admixture, the entire size range of discrete particles of that type have the same or substantially similar composition regardless of whether the particles are in contact with other particles.
  • the agglomerates themselves are considered as discrete particles and each discrete particle may be comprised of a composite of smaller primary particles and binder compositions.
  • geometric mean particle diameter means the geometric mass median diameter of a set of discrete particles as measured by any standard mass-based particle size measurement technique, preferably by dry sieving.
  • the phrase "geometric standard deviation" or “span” of a particle size distribution means the geometric breadth of the best- fitted log-normal function to the above-mentioned particle size data which can be accomplished by the ratio of the diameter of the 84.13 percentile divided by the diameter of the 50 th percentile of the cumulative distribution (D 84 13 /D 50 ); See Gotoh et al, Powder Technology Handbook, pp. 6-1 1, Meral Dekker 1997. .
  • the phrase “builder” means any inorganic material having “builder” performance in the detergency context, and specifically, organic or inorganic material capable of removing water hardness from washing solutions.
  • the term “bulk density” refers to the uncompressed, untapped powder bulk density, as measured by pouring an excess of powder sample through a funnel into a smooth metal vessel (e.g., a 500 ml volume cylinder), scraping off the excess from the heap above the rim of the vessel, measuring the remaining mass of powder and dividing the mass by the volume of the vessel.
  • the granular detergents of the present invention satisfy the desired performance characteristics of solubility and dispersion via the optimal selection of a series of parameters that allow the design of superior performing granular detergents.
  • a series of transitions may be employed to describe the solubility of a granular detergent from the point in time at which the powder is first wetted by the wash solution to the point in time at which the powder as reach its end point of dissolution into the wash solution.
  • the series of transitions starts with the rate of dispersion of the bulk mass of the powder, typically made up of millions of particles per dose, into well- dispersed single particles within the wash solution. Once dispersed, the individual particles are free to dissolve.
  • proper dispersion of particles is important to the design of a superior performing powdered detergent.
  • a poor dispersion of powder will tend to form the aforementioned lump-gels that are slow to dissolve and prone to leave consumer undesirable residues on fabrics.
  • the second of the transitions which may be employed to describe the solubility of powdered detergent is the rate of dissolution of the particles into the wash solution. Dissolution of dispersed particles continues after dispersion of the granules is complete.
  • the key parameter of a superior performing granular detergent is that the well-dispersed particles dissolve relatively quickly as compared to the length of the wash cycle. The earlier in time during the wash cycle that the powdered detergent is dissolved, the earlier detergent active ingredients are delivered to the wash providing a longer exposure of soiled fabrics to cleaning agents and providing for improved cleaning performance.
  • the last of the transitions employed to describe the solubility of the powdered detergent is the amount of powder which will not dissolve given a reasonable length of time in which to do it, otherwise known as insoluble particles.
  • Insoluble particles result in visible residues on fabrics as these insoluble particles are filtered from the wash solution by the fabrics themselves. Minimization of the particle size of these insoluble particles present in a powdered detergent leads to improve performance from high levels of active agents in the wash solution and to higher consumer acceptance from fewer visible residues on fabrics.
  • the rate of dispersion as employed herein is a measure of the speed at which particles disperse throughout a wash solution.
  • the rate of dispersion is a complex phenomena that is due in large part to interparticle interaction. However, this phenomena may be accurately described via the general stretched-exponential equation:
  • R is the residual at any point in time
  • t R* is the long term residual, i.e. undispersed particles
  • t is any single point in time
  • m is a stretching exponent that describes how the powder acts at the initial point in time, i.e the effect of initial wetting on its dispersion.
  • DT is dispersion time and t ⁇ ⁇ is the time of the wash cycle.
  • the dispersion time, DT is defined by the equation:
  • ⁇ disperse is a time constant that is characteristic of the exponential decay of the bulk mass of powder.
  • ⁇ disperse is the time at which -63% of the net amount of dispersible powder will be dispersed, i.e. bulk powder added minus insoluble residues, has dispersed.
  • the dispersion time is a dimensionless value which measures the relative dispersion over various wash cycles which vary considerably across load types and regions.
  • the stretching exponent, m is a value to describe how the powder acts at its initial point of wetting, i.e., is it a slow or fast dispersing powder.
  • R* is a value that describes how well the powder disperses completely.
  • the lower the value of R* the larger the amount of the powder that is dispersed in a reasonable amount of time, such as one hour.
  • ⁇ disperse is a value that describes the kinetics of dispersion.. The lower the value of ⁇ disperse the faster the detergent disperses. Thus, it takes all three values to accurately describe the dispersion of a detergent powder.
  • a powder may initially disperse very quickly and have a low m value but have a high residue mass (R*) because of lump-gel formation. Conversely, the powder may disperse completely but only at a slow rate, i.e. a high ⁇ disperse . Accordingly, it is the inter-relation of all three variables that are needed to accurately describe the dispersability of a granular detergent.
  • a powdered detergent composition may be fit against this equation by measuring the amount of residual detergent, R, as a function of time, i.e. at multiple times, over the course of a wash cycle and curve fitting these values to generate a value for R*, m and x diSperse .
  • the curve fitting may be performed via the use of various commercially available curve fitting software, such as for example, Excel Solver® with the constraint that R* must be some value greater than or equal to 0.
  • a superior performing detergent composition according to the present invention will have values for the long time residue, R*, of less than about 20%, more preferably less about 15% and most preferably less than about 5%, values of the dispersion time, DT, of less than about 0.5, preferably less than about 0.25 and most preferably less than about 0.12 and values of the stretching exponent, m, of less than about 2, more preferably less than about 1.5 and most preferably less than about 1. Meanwhile, values of R are preferably less than 25%, more preferably less than 18% and most preferably less than about 10% by weight of the composition.
  • the test employed to measure this residual detergent is the wire basket test, WBT which conforms to United States Pharmacopoeia Test 71 1 .
  • the WBT consists of a 1 litre vessel of stainless steel, plastic, or (preferably) borosilicate glass having a stainless steel stirrer approximately 4 mm thick.
  • a 20 mesh stationary basket (appprox. 4mm X 25mm) is made of stainless steel, being supported atop the one liter vessel by a plexiglas.
  • One liter of distilled water at about 4.44C (40F) is placed in the dissolution vessel and circulated continuously through the vessel.
  • a volume of granular detergent material is weighed into the stationary wire basket.
  • the basket is then suspended midway between the agitator shaft and side wall of the apparatus.
  • the agitator is then ran at 200 rpm.
  • the basket is then removed from the apparatus at periodic times, with the residue transferred to a weighing dish and dried to a constant weight.
  • the rate of dissolution, ROD, according to the present invention is a measure of the dissolution rate of the surfactant chemistry itself as it is delivered in the granular detergent particles.
  • the rate of dissolution is gauged as a percentage of total surfactant dissolved, as measured by chemical assay of the surfactant from filtered washwater.
  • the key is to dissolve well dispersed particles quickly relative to the length of the wash cycle.
  • the ROD predicts how quickly a detergent composition delivers its surfactant to the wash.
  • the ROD can be modeled using the expression:
  • U is the fraction of undissolved surfactant at any point in time
  • t is the long term surfactant residual, i.e. insoluble surfactant particles and/or precipitates
  • t is any single point in time
  • n is a stretching exponent that describes how the surfactant acts, i.e. dissolves, at the early stages of wetting in the test.
  • RT is dissolution time and 1 ⁇ ⁇ is the time of the wash cycle.
  • the dissolution time, RT is defined by the equation:
  • t ⁇ is the time of the wash cycle and ⁇ R0D is a time constant that is characteristic of the dissolution of surfactant.
  • ⁇ R0D is the time at which -63% of the net amount of soluble surfactant will dissolve, i.e. total surfactant added minus insoluble surfactant residues, has dissolved.
  • the dissolution time is a dimensionless value which measures the relative dissolution over various wash cycles which vary considerably across load types and regions.
  • RT provides for an accurate prediction of the dissolution of a powdered detergent in differing wash conditions and cycles.
  • the stretching exponent, m is a value to describe how the surfactant acts at its initial point of wetting, i.e., is it a slow or fast wetting surfactant.
  • U* is a value that describes how well the surfactant dissolves completely.
  • ⁇ R0D is a value that describes how long the surfactant takes to ultimately dissolve.
  • the lower the value of ⁇ R0D the faster the surfactant dissolves.
  • a powdered detergent composition may be fit against this equation by measuring the amount of residual surfactant, U, as a function of time, i.e. at multiple times, over the course of a wash cycle and curve fitting these values to generate a value for U*, n and ⁇ R0D .
  • the curve fitting may be performed as in the dispersion calculations via the use of various commercially available curve fitting software, such as for example, Excel Solver® with the constraint that U* must be some value greater than or equal to 0.
  • a superior performing detergent composition according to the present invention will have values for the long time residue, U*, of less than about 14%, more preferably less about 7% and most preferably less than about 3.5%, values of the dispersion time, RT, of less than about 0.5, preferably less than about 0.25 and most preferably less than about 0.12 and values of the stretching exponent, n, of less than about 2, more preferably less than about 1.5 and most preferably less than about 1. Meanwhile values for U are typically greater than 30% in 2 minutes and 70 % in 5 minutes, more preferably greater than 40% in 2 minutes and 80% in 5 minutes and most preferably greater than 50% in 2 minutes and 90% in 5 minutes.
  • test employed to measure the residual surfactant is described by the following procedure which conforms to United States Pharmacopoeia test 71 1.
  • a 1 liter vessel of stainless steel, plastic, or (preferably) borosilicate glass having a stainless steel stirrer approximately 4 mm thick is provided.
  • One liter of distilled water at about 10°C (50°F) is placed in the dissolution vessel and circulated continuously through the vessel.
  • a 10.0 gram (+/- 0.1 gram) sample is decanted into the water with the agitator turning at 200 rpm.
  • time intervals (30 seconds, 1, 2.5 and 5 minutes), a 10 cc sample is extracted and immediately filtered through 0.45 micron filter paper.
  • Insoluble Residues is a measure of the amount of particles in the granular detergent which will not dissolve in a reasonable period of time such as the length of the wash cycle. Insoluble residues larger than a certain size will wind up as visible specks or particles on fabrics as they are filtered from the wash water by the fabrics. The insoluble residues can be measured in the washwater before they are filtered through the fabrics. The measurements may be performed by conventional light scattering devices that use Fraunhoffer light scattering principles, such as for example Malvern or Horiba particle size analyzers. The unfiltered washwater is passed through a diffraction cell where dispersed particles scatter light passed through the cell. The degree of scattering is proportional to the size of the dispersed particles.
  • a superior performing detergent composition will have a D90 of insoluble residues of less than about 15 ⁇ m and more preferably a D90 of less than about lO ⁇ m. That is at least 90% of the insoluble residues in the washwater have a particle size of less than about 15 ⁇ m and more preferably less than about lO ⁇ m.
  • Detergent compositions which satisfy the transition profiles as disclosed above may be formulated with a varying array of ingredients and properties to achieve the overall superior solubility profile as defined by the transitions discussed above.
  • the granular detergent composition may achieve the desired benefits of solubility, improved aesthetics and flowability via optimal selection of the geometric mean particle diameter of certain levels of particles in the composition.
  • improved aesthetics it is meant that the consumer views a granular detergent product which has a more uniform appearance of particles as opposed to past granular detergent products which contained particles of varying size and composition.
  • at least about 50%, more preferably at least about 75%, even more preferably at least about 90%, and most preferably at least about 95%, by weight of the total particles in the detergent product have the selected mean particle size diameter. In this way, a substantial portion of the granular detergent product will have the uniform size so as to provide the aesthetic appearance desired by consumers.
  • the geometric mean particle diameter of the particles is from about 500 microns to about 1500 microns, more preferably from about 600 microns to about 1200 microns, and most preferably from about 700 microns to about 1000 microns.
  • the particle size distribution is defined by a relative tight geometric standard deviation or "span" so as not to have too many particles outside of the target size.
  • the geometric standard deviation is preferably is from about 1 to about 2, more preferably is from about 1.0 to about 1.7, even more preferably is from about 1.0 to about 1.4, and most preferably is from about 1.0 to about 1.2.
  • the average bulk density of the particles is preferably at least about 450 g/1, more preferably at least about 550 g/1, and most preferably at least about 650 g/1.
  • solubility is enhanced as a result of the particles in the detergent composition being more of the same size.
  • the actual "contact points" among the particles in the detergent composition is reduced which, in turn, reduces the "bridging effect" commonly associated with the "lump-gel” dissolution difficulties of granular detergent compositions.
  • Previous granular detergent compositions contained particles of varying sizes which leads to more contact points among the particles. For example, a large particle could have many smaller particles in contact with it rendering the particle site ripe for lump-gel formation. The level and uniform size of the particles in the granular detergent composition of the present invention avoids such problems.
  • the detergent composition will contain from about 1% to about 50% by weight of a detersive surfactant and from about 1% to about 75% by weight of a detergent builder.
  • the transition profile of the present invention may be satisfied via a more standard or uniform shape of the individual particles of the granular detergent.
  • a more uniform shape leads to more uniform dispersion and a reduction in the contact points between particles as discussed above.
  • Shape can be measured in a number of different ways known to those of ordinary skill in the art. One such method is using optical microscopy with Optimus (V5.0) image analysis software. Important calculated parameters are:
  • each of these attributes is important and can be averaged over the bulk granular detergent composition. Further, the combination of the two parameters as defined by the product of the parameters is important as well (i.e. both must be controlled to get a product with good appearance).
  • the granular detergent compositions of this invention have circularity less than about 50, preferably less than about 30, more preferably less than about 23, most preferably less than about 18. Also preferred are granular detergent compositions with aspect ratios less than about 2, preferably less than about 1.5, more preferably less than about 1.3 most preferably less than about 1.2.
  • the granular detergent compositions of this invention have a standard deviation of the number distribution of circularity less than about 20, that is preferably less than about 10, more preferably less than about 7 most preferably less than about 4.
  • the standard deviation of the number distribution of aspect ratios is preferably less than about 1 , more preferably less than about 0.5, even more preferably less than about 0.3, most preferably less than about 0.2.
  • granular detergent compositions are produced wherein the product of circularity and aspect ratio is less than about 100, preferably less than about 50, more preferably less than about 30, and most preferably less than about 20. Also preferred are granular detergent compositions with the standard deviation of the number distribution of the product of circularity and aspect ratio of less than about 45, preferably less than about 20, more preferably less than about 7 most preferably less than about 2.
  • Yet another detergent design method for achieving granular detergents satisfying the aforementioned transition profile involves the use of homogeneous detergents compositions wherein the homogeneous detergent contributes to the aforementioned benefits.
  • the homogeneity number describes the distribution of ingredients within a specific particles and between particles in a composition.
  • key ingredients such as surfactant both within the particle and between particles was optimal.
  • detergent composition would consist of a uniform particle of the same ingredients, such as spray-dried detergent ingredients and have significant solubility drawbacks.
  • detergent compositions have consisted of differing particles of dual particle systems. However, these particles where differ composition and form, e.g. spray-dried granules and agglomerates. These detergent products also experience solubility drawbacks.
  • a detergent composition that has a homogeneity number of less than about 0.5 or greater than about 1.0, more preferably, greater than 1.25 and most preferably greater than about 1.5 have superior solubility profiles per the present invention.
  • the homogeneity number is represented by the formula:
  • X bulk is the ratio of the concentration of the selected ingredient in the particle with the lowest levels of that ingredient to the concentration of the selected ingredient in the particle with the highest levels of the selected ingredient
  • X part is the ratio of the concentration in the discrete area with the lowest amount of the selected ingredient to the concentration in the discrete area of the particle having the highest amounts of the selected ingredient, of less than about 0.5 or greater than about 1 , preferably greater than about 1.25 and more preferably greater than about 1.5.
  • X bulk is the ratio of the concentration of a selected detergent ingredient such as surfactant, builder, etc. in the particles in the composition with the lowest levels of the selected ingredient to the concentration of the selected ingredient in the particles with the highest level of the selected ingredient. This provides the homogeneity between particles in the composition.
  • X bu]k is represent by the formula:
  • X min is the concentration of the selected ingredient in the particles in the composition with the lowest levels of the selected ingredient and X max concentration of a selected detergent ingredient in the particles in the composition with the highest levels of the selected ingredient.
  • X bulk would be equal to one (1) or 0.25/0.25.
  • a composition which comprises a spray dried granule of 20% active surfactant and a detergent agglomerate of 30% detergent active X buIk would be equal to 0.67 or 0.2/0.3.
  • X partk is the ratio of the concentration of a selected detergent ingredient such as surfactant, builder, etc. in the same particle, or in other words a measure of the homogeneity of the individual particle.
  • X part is the ratio of the selected ingredient in discrete areas of the particle.
  • X part is the ratio of the concentration in the discrete with the lowest concentration of the ingredient to the concentration of the selected ingredient in the discrete area with the highest concentration within the same particle.
  • X part is represent by the formula:
  • a discrete area of the present invention is one in which the is a clear morphological difference between the areas and is typically an area that accounts for more than 1%, preferably, 5% the volume of the particle.
  • a particle that is homogeneous throughout the particle has only one (1) discrete are.
  • a particles which has the same concentration throughout such as a spray-dried granule with a active concentration of 25% surfactant, X part would be equal to one (1) or 0.25/0.25 as the particle contains only one discrete area.
  • X bul in a particle, which is agglomerated from two different starting ingredients such as spray-dried granules having 5% active surfactant and dry detergent agglomerates having 50% active surfactant to form mixed agglomerates as defined herein, X bul would be equal to 0.1 or 0.05/0.5.
  • the homogeneity number of the present invention is to be calculated on particles which comprise the bulk of the detergent composition.
  • particles which individually or collectively account for less than about 10% by weight of the finished composition should not be employed in the calculation of homogeneity number.
  • the ingredient typically include admix ingredients such for example, enzymes, bleach ingredients, perfumes ingredients, and various other minor additions.
  • a fully formulated detergent composition which comprises a surfactant system having an electrolyte rich surfactant zone and an electrolyte poor surfactant zone may be employed to provide a granular detergent with improved solubility.
  • the composition may be in the form of a single particle with separate discrete surfactant zones or may be in the form of multiple particles wherein each surfactant zone is represented by a separate particle.
  • the electrolyte poor surfactant zone comprises less than about 20%, more preferably less than about 10%, even more preferably less than about 2% and most preferably about 0% electrolyte in conjunction with a surfactant or blend of surfactants selected from the class of alcohol sulfate surfactants.
  • the electrolyte rich surfactant zone comprises more than about 20%, more preferably more than about 35% and most preferably more than about 45% electrolyte in conjunction with a surfactant or blend of surfactants selected from the class of alkyl benzene sulfonate surfactants.
  • zone separation wherein the electrolyte is separated from the proximity of the alcohol sulfate surfactants, the formation of lump-gel residues is minimized and/or reduced resulting in both superior dissolution and dispersion profiles for the granular detergent of the present invention.
  • Yet another method of improving solubility of granular detergent compositions is to selectively coat with a coating agent the particles and in particular particles that include ingredients that are sticky in nature such as surfactants.
  • a coating agent the particles and in particular particles that include ingredients that are sticky in nature such as surfactants.
  • Such coating methods are well known to those of ordinary skill in the art, for example spray drums.
  • Granular compositions are typically designed to provide an in the wash pH of from about 7.5 to about 1 1.5, more preferably from about 9.5 to about 10.5.
  • Low density compositions can be prepared by standard spray-drying processes.
  • Various means and equipment are available to prepare high density compositions.
  • Current commercial practice in the field employs spray-drying towers to manufacture compositions which have a density less than about 500 g/1. Accordingly, if spray-drying is used as part of the overall process, the resulting spray-dried particles must be further densified using the means and equipment described hereinafter.
  • the formulator can eliminate spray-drying by using mixing, densifying and granulating equipment that is commercially available. The following is a nonlimiting description of such equipment suitable for use herein.
  • high density i.e., greater than about 500, preferably greater than about 600, grams/liter or "g/1"
  • high solubility, free-flowing, granular detergent compositions according to the present invention.
  • Current commercial practice in the field employs spray-drying towers to manufacture granular laundry detergents which often have a density less than about 500 g/1.
  • an aqueous slurry of various heat-stable ingredients in the final detergent composition are formed into homogeneous granules by passage through a spray-drying tower, using conventional techniques, at temperatures of about 175°C to about 225°C.
  • additional process steps as described hereinafter must be used to obtain the level of density (i.e., > 600 g/1) required by modern compact, low dosage detergent products.
  • spray-dried granules from a tower can be densified further by loading a liquid such as water or a nonionic surfactant into the pores of the granules and/or subjecting them to one or more high speed mixer/densifiers.
  • a suitable high speed mixer/densifier for this process is a device marketed under the tradename "Lodige CB 30" or "L ⁇ dige CB 30 Recycler” which comprises a static cylindrical mixing drum having a central rotating shaft with mixing/cutting blades mounted thereon.
  • the ingredients for the detergent composition are introduced into the drum and the shaft/blade assembly is rotated at speeds in the range of 100-2500 rpm to provide thorough mixing/densification.
  • the preferred residence time in the high speed mixer/densifier is from about 1 to 60 seconds.
  • Other such apparatus includes the devices marketed under the tradename “Shugi Granulator” and under the tradename “Drais K-TTP 80).
  • Another process step which can be used to densify further spray-dried granules involves grinding and agglomerating or deforming the spray-dried granules in a moderate speed mixer/densifier so as to obtain particles having lower intraparticle porosity.
  • Equipment such as that marketed under the tradename "Lodige KM” (Series 300 or 600) or “Lodige Ploughshare” mixer/densifiers are suitable for this process step. Such equipment is typically operated at 40- 160 rpm.
  • the residence time of the detergent ingredients in the moderate speed mixer/densifier is from about 0.1 to 12 minutes.
  • Other useful equipment includes the device which is available under the tradename "Drais K-T 160".
  • This process step which employs a moderate speed mixer/densifier can be used by itself or sequentially with the aforementioned high speed mixer/densifier (e.g. Lodige CB) to achieve the desired density.
  • a moderate speed mixer/densifier e.g. Lodige KM
  • the aforementioned high speed mixer/densifier e.g. Lodige CB
  • Other types of granules manufacturing apparatus useful herein include the apparatus disclosed in U.S. Patent 2,306,898, to G. L. Heller, December 29, 1942.
  • the reverse sequential mixer/densifier configuration is also contemplated by the invention.
  • One or a combination of various parameters including residence times in the mixer/densifiers, operating temperatures of the equipment, temperature and/or composition of the granules, the use of adjunct ingredients such as liquid binders and flow aids, can be used to optimize densification of the spray-dried granules in the process of the invention.
  • adjunct ingredients such as liquid binders and flow aids
  • Patent 4,637,891 issued January 20, 1987 (granulating spray-dried granules with a liquid binder and aluminosilicate); Kruse et al, U.S. Patent 4,726,908, issued February 23, 1988 (granulating spray-dried granules with a liquid binder and aluminosilicate); and, Bortolotti et al, U.S. Patent 5,160,657, issued November 3, 1992 (coating densified granules with a liquid binder and aluminosilicate).
  • the formulator can eliminate the spray-drying step by feeding, in either a continuous or batch mode, starting detergent ingredients directly into mixing/densifying equipment that is commercially available.
  • One particularly preferred embodiment involves charging a surfactant paste and an anhydrous builder material into a high speed mixer/densifier (e.g. Lodige CB) followed by a moderate speed mixer/densifier (e.g. Lodige KM) to form high density detergent agglomerates.
  • a high speed mixer/densifier e.g. Lodige CB
  • a moderate speed mixer/densifier e.g. Lodige KM
  • the liquid/solids ratio of the starting detergent ingredients in such a process can be selected to obtain high density agglomerates that are more free flowing and crisp.
  • the process may include one or more recycle streams of undersized particles produced by the process which are fed back to the mixer/densifiers for further agglomeration or build-up.
  • the oversized particles produced by this process can be sent to grinding apparatus and then fed back to the mixing/densifying equipment.
  • These additional recycle process steps facilitate build-up agglomeration of the starting detergent ingredients resulting in a finished composition having a uniform distribution of the desired particle size (400-700 microns) and density (> 550 g/1). See Capeci et al, U.S. Patent 5,516,448, issued May 14, 1996 and Capeci et al, U.S. Patent 5,489,392, issued February 6, 1996.
  • the high density detergent composition of the invention can be produced using a fluidized bed mixer.
  • the various ingredients of the finished composition are combined in an aqueous slurry (typically 80% solids content) and sprayed into a fluidized bed to provide the finished detergent granules.
  • this process can optionally include the step of mixing the slurry using the aforementioned Lodige CB mixer/densifier or a "Flexomix 160" mixer/densifier, available from Shugi. Fluidized bed or moving beds of the type available under the tradename "Escher Wyss" can be used in such processes.
  • Another suitable process which can be used herein involves feeding a liquid acid precursor of an anionic surfactant, an alkaline inorganic material (e.g. sodium carbonate) and optionally other detergent ingredients into a high speed mixer/densifier (residence time 5-30 seconds) so as to form agglomerates containing a partially or totally neutralized anionic surfactant salt and the other starting detergent ingredients.
  • a high speed mixer/densifier e.g. Lodige KM
  • a moderate speed mixer/densifier e.g. Lodige KM
  • high density detergent compositions according to the invention can be produced by blending conventional or densified spray-dried detergent granules with detergent agglomerates in various proportions (e.g. a 60:40 weight ratio of granules to agglomerates) produced by one or a combination of the processes discussed herein.
  • Additional adjunct ingredients such as enzymes, perfumes, brighteners and the like can be sprayed or admixed with the agglomerates, granules or mixtures thereof produced by the processes discussed herein.
  • Bleaching compositions in granular form typically limit water content, for example, to less than about 7% free water, for best storage stability.
  • starting ingredients comprising spray-dried granules and agglomerates formed as described above may be combined, optionally with other starting ingredients, such as carbonate, etc, and liquid binder material in a high, moderate or low speed mixer and agglomerated into a single mixed agglomerate particle to provide a detergent with a uniform size and distribution.
  • the mixed agglomerate may be formed in a single mixer or series of mixers including moderate speed mixer/densifiers in combination with fluid bed granulators.
  • the surfactant system of the detergent composition may include anionic, nonionic, zwitterionic, ampholytic and cationic classes and compatible mixtures thereof.
  • Detergent surfactants are described in U.S. Patent 3,664,961, Norris, issued May 23, 1972, and in U.S. Patent 3,919,678, Laughlin et al., issued December 30, 1975, both of which are incorporated herein by reference.
  • Cationic surfactants include those described in U.S. Patent 4,222,905, Cockrell, issued September 16, 1980, and in U.S. Patent 4,239,659, Murphy, issued December 16, 1980, both of which are also incorporated herein by reference.
  • Nonlimiting examples of surfactant systems include the conventional Ci ]-C] g alkyl benzene sulfonates ("LAS") and primary, branched-chain and random Ci 0-C20 alkyl sulfates ("AS”), the C ⁇ 0 -C ⁇ 8 secondary (2,3) alkyl sulfates of the formula CH (CH 2 ) x (CHOS03 " M + ) CH3 and CH3 (CH 2 ) y (CHOS0 3 " M + ) CH 2 CH 3 where x and (y + 1) are integers of at least about 7, preferably at least about 9, and M is a water-solubilizing cation, especially sodium, unsaturated sulfates such as oleyl sulfate, the Ci Q-Ci g alkyl alkoxy sulfates ("AE X S”; especially EO 1-7 ethoxy sulfates), Ci Q-C I 8 alkyl alkoxy carboxylates (especially the EO 1-5
  • the conventional nonionic and amphoteric surfactants such as the C12-C18 alkyl ethoxylates ("AE") including the so-called narrow peaked alkyl ethoxylates and C6-C12 alkyl phenol alkoxylates (especially ethoxylates and mixed ethoxy/propoxy), C12-C1 g betaines and sulfobetaines ("sultaines"), C I Q-C I amine oxides, and the like, can also be included in the surfactant system.
  • AE C12-C18 alkyl ethoxylates
  • C6-C12 alkyl phenol alkoxylates especially ethoxylates and mixed ethoxy/propoxy
  • C12-C1 g betaines and sulfobetaines sultaines
  • C I Q-C I amine oxides and the like
  • the Ci Q-C J g N-alkyl polyhydroxy fatty acid amides can also
  • sugar- derived surfactants include the N-alkoxy polyhydroxy fatty acid amides, such as C J Q-C I 8 N-(3- methoxypropyl) glucamide.
  • the N-propyl through N-hexyl Ci 2-C1 glucamides can be used for low sudsing.
  • C ] ⁇ -C20 conventional soaps may also be used. If high sudsing is desired, the branched-chain Ci o-Ci g soaps may be used. Mixtures of anionic and nonionic surfactants are especially useful. Other conventional useful surfactants are listed in standard texts.
  • the detergent composition can, and preferably does, include a detergent builder.
  • Builders are generally selected from the various water-soluble, alkali metal, ammonium or substituted ammonium phosphates, polyphosphates, phosphonates, polyphosphonates, carbonates, silicates, borates, polyhydroxy sulfonates, polyacetates, carboxylates, and polycarboxylates.
  • the alkali metal especially sodium, salts of the above.
  • Preferred for use herein are the phosphates, carbonates, silicates, C. hopefully , careful fatty acids, polycarboxylates, and mixtures thereof. More preferred are sodium tripolyphosphate, tetrasodium pyrophosphate, citrate, tartrate mono- and di-succinates, sodium silicate, and mixtures thereof (see below).
  • inorganic phosphate builders are sodium and potassium tripolyphosphate, pyrophosphate, polymeric metaphosphate having a degree of polymerization of from about 6 to 21, and orthophosphates.
  • polyphosphonate builders are the sodium and potassium salts of ethylene diphosphonic acid, the sodium and potassium salts of ethane 1 -hydroxy- 1 , 1 -diphosphonic acid and the sodium and potassium salts of ethane, 1 , 1 ,2-triphosphonic acid.
  • Other phosphorus builder compounds are disclosed in U.S. Patents 3,159,581; 3,213,030; 3,422,021; 3,422,137; 3,400,176 and 3,400,148, all of which are incorporated herein by reference.
  • nonphosphorus, inorganic builders are sodium and potassium carbonate, bicarbonate, sesquicarbonate, tetraborate decahydrate, and silicates having a weight ratio of SiOfact to alkali metal oxide of from about 0.5 to about 4.0, preferably from about 1.0 to about 2.4.
  • Water-soluble, nonphosphorus organic builders useful herein include the various alkali metal, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates and polyhydroxy sulfonates.
  • polyacetate and polycarboxylate builders are the sodium, potassium, lithium, ammonium and substituted ammonium salts of ethylene diamine tetraacetic acid, nitrilotriacetic acid, oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, and citric acid.
  • Polymeric polycarboxylate builders are set forth in U.S. Patent 3,308,067, Diehl, issued March 7, 1967, the disclosure of which is incorporated herein by reference.
  • Such materials include the water-soluble salts of homo- and copolymers of aliphatic carboxylic acids such as maleic acid, itaconic acid, mesaconic acid, fumaric acid, aconitic acid, citraconic acid and methylenemalonic acid.
  • Some of these materials are useful as the water-soluble anionic polymer as hereinafter described, but only if in intimate admixture with the nonsoap anionic surfactant.
  • polyacetal carboxylates for use herein are the polyacetal carboxylates described in U.S. Patent 4,144,226, issued March 13, 1979 to Crutchfield et al, and U.S. Patent 4,246,495, issued March 27, 1979 to Crutchfield et al., both of which are incorporated herein by reference.
  • These polyacetal carboxylates can be prepared by bringing together under polymerization conditions an ester of glyoxylic acid and a polymerization initiator. The resulting polyacetal carboxylate ester is then attached to chemically stable end groups to stabilize the polyacetal carboxylate against rapid depolymerization in alkaline solution, converted to the corresponding salt, and added to a detergent composition.
  • Particularly preferred polycarboxylate builders are the ether carboxylate builder compositions comprising a combination of tartrate monosuccinate and tartrate disuccinate described in U.S. Patent 4,663,071, Bush et al., issued May 5, 1987, the disclosure of which is incorporated herein by reference.
  • Water-soluble silicate solids represented by the formula SiO ⁇ »M Thread0, M being an alkali metal, and having a SiO «:M_O weight ratio of from about 0.5 to about 4.0, are useful salts in the detergent granules of the invention at levels of from about 2% to about 15% on an anhydrous weight basis, preferably from about 3% to about 8%.
  • Anhydrous or hydrated particulate silicate can be utilized, as well. Any number of additional ingredients can also be included as components in the granular detergent composition.
  • Bleaching agents and activators are described in U.S. Patent 4,412,934, Chung et al., issued November 1, 1983, and in U.S. Patent 4,483,781 , Hartman, issued November 20, 1984, both of which are incorporated herein by reference.
  • Chelating agents are also described in U.S. Patent 4,663,071, Bush et al., from Column 17, line 54 through Column 18, line 68, incorporated herein by reference.
  • Suds modifiers are also optional ingredients and are described in U.S. Patents 3,933,672, issued January 20, 1976 to Bartoletta et al., and 4,136,045, issued January 23, 1979 to Gault et al., both incorporated herein by reference.
  • Suitable smectite clays for use herein are described in U.S. Patent 4,762,645, Tucker et al., issued August 9, 1988, Column 6, line 3 through Column 7, line 24, incorporated herein by reference.
  • Suitable additional detergency builders for use herein are enumerated in the Baskerville patent, Column 13, line 54 through Column 16, line 16, and in U.S. Patent 4,663,071, Bush et al., issued May 5, 1987, both incorporated herein by reference.
  • TAS Sodium tallow alkyl sulfate
  • Nal2(A102Si02)12.27H20 having a primary particle size in the range from 0.1 to 10 micrometers (weight expressed on an anhydrous basis)
  • Bicarbonate Anhydrous sodium bicarbonate with a particle size distribution between
  • Amylase Amylolytic enzyme having 1.6% by weight of active enzyme, sold by
  • Lipase Lipolytic enzyme having 2.0% by weight of active enzyme, sold by
  • NAC-OBS (6-nonamidocaproyl) oxybenzene sulfonate
  • EDDS Ethylenediamine-N,N'-disuccinic acid, (S,S) isomer in the form of its sodium salt.
  • Photoactivated Sulfonated zinc phthlocyanine encapsulated in bleach (1) dextrin soluble polymer
  • HEDP 1 , 1 -hydroxyethane diphosphonic acid PEGx Polyethylene glycol, with a molecular weight of x (typically 4,000) QEA bis((C2H50)(C2H4O)n)(CH3) -N+-C6H12-N+-(CH3) bis((C2H50)-
  • Example I The following compositions are in accordance with the invention.
  • compositions exemplified above have at least 90% by weight of particles having a geometric mean particle diameter of from about 850 microns with a geometric standard deviation of from about 1.2.
  • the compositions have improved aesthetics, flowability and solubility.
  • formula I has a dispersion wherein R* is less than 1%, m is 0.86, t disperse is 2.5 minutes and a ROD of U* of 11.9%, t R0D of 2.23 and n is 1.15.

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Abstract

L'invention concerne une composition de détergent granulaire présentant une densité apparente d'au moins environ 400 g/l, et qui est caractérisée par un taux de dispersion dans des conditions de contrainte d'eau froide définies par l'équation (1), dans laquelle R représente le détergent non dispersé résiduel à n'importe quel moment donné t; R* est le détergent non dispersé résiduel à long terme qui présente une valeur inférieure à environ 14 % de la quantité totale d'un dosage initial de détergent; t représente n'importe quel moment donné; m est un exposant d'étirement présentant une valeur inférieure à environ 2; DT représente le temps de dispersion présentant une valeur inférieure à environ 0,5; et tlavage est la durée du cycle de lavage; et au moins 90 % des résidus particulaires insolubles de ladite composition de détergent granulaire présente des dimensions de particules inférieures à 15 νm. Dans des modes de réalisation préférés, la composition de détergent présente un taux de dissolution dans des conditions de contrainte d'eau froide définies par l'équation (2), dans laquelle U représente la fraction de tensioactif non dissous à n'importe quel moment donné t; U* est le tensioactif non dissous résiduel à long terme présentant une valeur inférieure à environ 14 % de la quantité totale d'un dosage initial de tensioactif; t représente n'importe quel moment donné; n est un exposant d'étirement présentant une valeur inférieure à environ 2, RT représente le temps de dissolution présentant une valeur inférieure à environ 0,5; et tlavage est la durée du cycle de lavage.
EP99949920A 1998-09-25 1999-09-24 Compositions de detergent granulaires presentant des profils de solubilite ameliores Withdrawn EP1115838A1 (fr)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
WOPCT/US98/00202 1998-09-25
US9800202 1998-09-25
US14825899P 1999-08-11 1999-08-11
US148258P 1999-08-11
PCT/US1999/022396 WO2000018878A1 (fr) 1998-09-25 1999-09-24 Compositions de detergent granulaires presentant des profils de solubilite ameliores

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