A PROCESS FOR FORMING A FABRIC CONDITIONING COMPOSITION FROM A FABRIC CONDITIONING CONCENTRATE

Abstract: A process for forming a fabric conditioning composition includes the steps of providing a fabric conditioning concentrate; providing water; and providing preneutralized 1,1-hydroxyethane diphosphonic acid. The fabric conditioning concentrate, water, and the pre-neutralized 1,1-hydroxyethane diphosphonic acid are combined in a mixer to form a fabric conditioning composition having a conductivity of from about 700 theta S/cm to about 3,000 theta S/cm. The fabric conditioning concentrate includes a hydrolyzable fabric conditioning active, while the pre-neutralized 1,1-hydroxyethane diphosphonic acid is pre-neutralized to a pH of from about 2.1 to about 2.4. The fabric conditioning composition formed by this process possesses significantly improved viscosity and phase stability.

Description: A PROCESS FOR FORMING A FABRIC CONDITIONING COMPOSITION FROM A FABRIC CONDITIONING CONCENTRATE FIELD OF THE INVENTION The present invention relates to a process for forming a fabric conditioning composition. Specifically, the present invention relates to a process for forming a fabric conditioning composition from a fabric conditioning concentrate. BACKGROUND OF THE INVENTION Fabric conditioning compositions and processes for forming them are known, and typically involve mixing the ingredients in a mixer, and homogenizing them to a finished fabric conditioning composition. Typically in the past, the finished fabric conditioning composition is then bottled, packed, and shipped to the store and/or distributors in a ready-for sale form. However, as the world market has increased, it has been found that it is no longer cost-effective to ship completed products, such as a fabric conditioning composition, to all locales. This is especially true when certain raw materials, such as a solvent, dye, perfume, etc., are readily available at a location near the final point of sale. In short, it may make fiscal sense to ship a concentrated composition, such as a fabric conditioning concentrate, to a local production site, add the loGal raw materials, and then bottle, pack, and ship the finished product to the store and/or distributor for sale. As a finished fabric conditioning composition will typically be in the form of an aqueous solution or an aqueous suspension, it has been found that shipping a fabric conditioning concentrate which lacks only minor ingredients and water, is an effective and cost-effective production method which reduces the costs of the finished product. Since a solvent such as water is readily available, and yet can make up 50% or more of a fabric conditioning composition, it has been found that the total production costs plus shipping costs are significantly reduced by forming and shipping a fabric conditioning concentrate, which is then diluted with water and/or another solvent at a location closer to the point of sale. This can effectively cut shipping costs by 50% or more, which in turn significantly reduces the cost of the product to the consumer. However, it has now been found that in certain conditions, such as when a fabric conditioning concentrate is diluted with water and a chelant such as 1 ,1- hydroxyethane diphosphonic acid, the physical stability and/or performance of the final fabric conditioning composition may be impaired. Specifically, it has been found that the viscosity may increase to a point where the composition is unacceptable to a consumer, the final fabric conditioning composition may exhibit phase separation, and/or the final fabric conditioning composition may possess impaired performance. Accordingly, the need exists for a process which forms a fabric conditioning composition from a fabric conditioning concentrate, and yet reduces and/or solves the physical stability problems, such as described above. The need also exists for a fabric conditioning composition which has improved physical stability. SUMMARY OF THE INVENTION The present invention relates to a process for forming a fabric conditioning composition includes the steps of providing a fabric conditioning concentrate; providing water; and providing pre-neutralized 1 ,1-hydroxyethane diphosphonic acid. The fabric conditioning concentrate, water, and the pre-neutralized 1 ,1- hydroxyethane diphosphonic acid are combined in a mixer to form a fabric conditioning composition having a conductivity of from about 700 μS/cm to about 3,000 μS/cm. The fabric conditioning concentrate includes a hydrolyzable fabric conditioning active, while the pre-neutralized 1 ,1-hydroxyethane diphosphonic acid is pre-neutralized to a pH of from about 2.1 to about 2.4. The present invention also relates to a fabric conditioning composition as formed by this process. It has now been found that a fabric conditioning composition which is formed by this process possesses significantly improved physical properties, such as improved viscosity and phase stability. In addition, it has been found that the present process provides a fabric conditioning composition which has performance which is comparable to a fabric conditioning composition which is not made from a fabric conditioning concentrate. These and other features, aspects, advantages, and variations of the present invention, and the embodiments described herein, will become evident to those skilled in the art from a reading of the present disclosure with the appended claims, and are covered within the scope of these claims. DETAILED DESCRIPTION OF THE INVENTION All percentages, ratios and proportions herein are by weight of the final fabric conditioning composition, unless otherwise specified. All temperatures are in degrees Celsius (°C) unless otherwise specified. All documents cited are incorporated herein by reference in their entireties. Citation of any reference is not an admission regarding any determination as to its availability as prior art to the claimed invention. As used herein, the term "alkyl" means a hydrocarbyl moiety which is straight, cyclic or branched, saturated or unsaturated. Unless otherwise specified, alkyl moieties are preferably saturated or unsaturated with double bonds, preferably with one or two double bonds. Included in the term "alkyl" is the alkyl portion of acyl groups. Fabric Conditioning Concentrate The fabric conditioning concentrate useful herein is pre-formed in a first manufacturing and/or production facility, and is intended to be shipped, and/or transported to one or more other manufacturing and/or production facilities for further processing to form a fabric conditioning composition. In an alternate embodiment, the fabric conditioning concentrate need not necessarily be shipped and/or transported, but may be pre-formed and then stored for a period of time, prior to being further processed to form a fabric conditioning composition. The pre-forming of a fabric conditioning concentrate provides many advantages, such as economies of scale, centralized production, storage stability, ease of transport, reduced transportation costs, and the easy production of a base formulation. The fabric conditioning concentrate useful herein typically includes a hydrolyzable fabric conditioning agent in addition to one or more ingredients common in a fabric conditioning composition, such as for example, a suds suppressor, a soil release agent, an antimicrobial agent, an optical brightener, a thickener, a solvent, a dye, a perfume, and a mixture thereof, and preferably a silicone suds suppressor, a soil release agent, an antimicrobial agent, an optical brightener, a solvent, and a mixture thereof. While ingredients which modify the aesthetics of the final fabric conditioning composition may be included in the fabric conditioning concentrate, such ingredients are preferably not present. This is especially preferred, as it allows the formulator the flexibility to provide a single base fabric conditioning concentrate for many locales and regions, while also being able to tailor the final fabric conditioning composition to local tastes by adding locally preferred dyes, perfumes, etc., at the final processing step. The levels of the ingredients in the fabric conditioning concentrate are adjusted to take into account factors such as the desired ingredient levels in the final fabric conditioning composition, the amount of dilution which will take place during additional processing, the stability of the ingredients in a fabric conditioning concentrate, etc. For example, if the final fabric conditioning composition is to contain 10% by weight of a hydrolyzable fabric conditioning active, and if the fabric conditioning concentrate will be diluted with an equal weight of other ingredients (solvent, dye, etc.) during the additional processing steps, then the fabric conditioning concentrate should contain 20% by weight of a hydrolyzable fabric conditioning active. As a general rule, the fabric conditioning concentrate will typically range from about 10% to about 70%, preferably from about 15% to about 60%, and more preferably from about 25% to about 50% of the fabric conditioning composition. Since the amount of dilution, the ingredients, and the final concentrations of these ingredients will vary widely from case-to- case and between different fabric conditioning compositions, the weight ranges and/or levels of ingredients useful herein are provided with respect to the final conditioning composition, unless specifically stated otherwise. When placed in contact with a fabric, the hydrolyzable fabric conditioning composition useful herein provides one or more benefits such consumer- desirable benefits such as softness, skin comfort, reduced static, increased fluffiness, improved fiber and color maintenance, reduced wrinkling, reduced tangling, reduced surface friction, etc. The fabric conditioning concentrate takes into account the dilution which occurs during further processing, and contains a sufficient amount of a hydrolyzable fabric conditioning active so as to provide the final fabric conditioning composition with a level of the hydrolyzable fabric conditioning active of from about 0.1 % to about 90%, preferably from about 0.5% to about 70%, more preferably from about 1 % to about 40%, and even more preferably from about 4% to about 15%, by weight of the fabric conditioning composition. The hydrolyzable fabric conditioning active herein is typically a fabric conditioning active which contains one or more alkoxylated moieties, ester moieties, ether moieties, and/or fatty acid moieties, which is hydrolyzable under acidic conditions. Without intending to be limited by theory, it is believed that a hydrolyzable fabric conditioning active is generally desirable from a cost, effectiveness, and biodegradability standpoint; however, it has also been found that a hydrolyzable fabric conditioning active may be easily hydrolyze when combined with 1 ,1-hydroxyethane diphosphonic acid (HEDP), if the HEDP is not pre-neutralized and combined with the fabric conditioning concentrate according to the method described herein. Specifically, it has been found that when HEDP is not pre-neutralized to within the pH range described, the acid moieties thereof may react with the fatty acid ester and/or alkoxylate groups to release the fatty acid and/or alkoxylate group. Furthermore, it has also been found that if the ionic strength of the final fabric conditioning composition is outside of the range described herein, then the HEDP may still hydrolyze the hydrolyzable fabric conditioning active during processing and/or storage. When hydrolyzed, the fatty acid/alkoxylate/etc. moiety may separate from the rest of the molecule and cause noticeable phase separation, a viscosity change, and/or reduced fabric conditioning effectiveness. Such a phase-separated, viscous and/or reduced efficacy fabric conditioning composition is unacceptable to a consumer. Accordingly, the problems addressed by the present invention are especially acute with such a hydrolyzable fabric conditioning active. Preferably the hydrolyzable fabric conditioning active is a quaternary ammonium compound having one or more ethoxylated moieties and/or fatty acid moieties, which is susceptible to acid-catalyzed hydrolysis. An example of a highly preferred fabric conditioning active useful herein is ditallow or dipalmityl dimethylammonium chloride or methyl sulfate; dihydrogenated tallow (palm) dimethylammonium chloride; dihydrogenated tallow (palm) dimethylammonium methylsulfate; distearyl dimethylammonium chloride; dioleyl dimethylammonium chloride or methyl sulfate; dipalmityl hydroxyethyl methylammonium chloride or methyl sulfate; stearyl benzyl dimethylammonium chloride or methyl sulfate; tallow (palm) trimethylammonium chloride or methyl sulfate; hydrogenated tallow (palm) trimethylammonium chloride or methyl sulfate; C12-2O alkyl ethoxy hydroxyethyl or hydroxyethyl dimethylammonium chloride or methyl sulfate; di-C-| 2-20 a ' dihydroxyethyl or diethoxyhydroxyethyl methylammonium chloride or methyl sulfate; di(stearoyloxyethyl) dimethylammonium chloride or methyl sulfate; di(tallow-oxy-ethyl) or di(palm-oxy-ethyl) dimethylammonium chloride or methyl sulfate; monotallow-oxy-ethyl or monopalm-oxy-ethyl, dihydroxyethyl, monomethyl, ammonium chloride or methyl sulfate, ditallow (dipalm) imidazolinium methylsulfate or chloride; ditallow-ethoxy-ethyl or di-palm- ethoxy-ethyl di-ethyl, mono-ethoxy-ethyl methyl ammonium chloride or methyl sulfate, 1-(2-tallowylamidoethyl)-2-tallowyl imidazolinium methylsulfate, 1-(2- palmitylamidoethyl)-2-palmityl imadazolinium chloride or methyl sulfate, dimethyl bis (stearoyl oxyethyl) ammonium chloride, and a mixture thereof. The suds suppressor useful herein is typically a silicone suds suppressor, for example, a polyorganosiloxane oil, such as polydimethylsiloxane, dispersions or emulsions of a polyorganosiloxane oil or resin, and combinations of polyorganosiloxane with silica particles, wherein the polyorganosiloxane is chemisorbed or fused onto the silica. Silicone suds suppressors are well known in the art and are, for example, disclosed in U.S. Patent 4,265,779, issued May 5, 1981 to Gandolfo et al and European Patent Application No. 89307851.9, published February 7, 1990, by Starch. Other silicone suds suppressors are disclosed in U.S. Patent 3,455,839 to Rauner, issued July 15, 1969 which relates to compositions and processes for defoaming aqueous solutions by incorporating therein small amounts of polydimethylsiloxane fluids. Mixtures of silicone and silanated silica suds suppressors are described, for instance, in German Patent Application DOS 2,124,526 to Bartolotta and Eymery, issued June 28, 1979. Silicone defoamers and suds controlling agents in granular detergent compositions are disclosed in U.S. Patent 3,933,672, to Bartolotta, et al., issued January 20, 1976 and in U.S. Patent 4,652,392, to Baginski, et al., issued March 24, 1987. If present, the suds suppressor will typically be present in the fabric conditioning composition at a level of from about 0.0001 to about 1 %, preferably from about 0.001 to about 0.1 %, by weight. Optionally, the fabric conditioning concentrate herein may contain a soil release agent. Typically, this will be at a level so as to provide from 0.01 % to about 10%, preferably from about 0.1 % to about 5%, more preferably from about 0.1 % to about 2% by weight, of a soil release agent in the final fabric conditioning composition. Preferably, such a soil release agent is a polymer, such as copolymeric blocks of terephthalate and polyethylene oxide or polypropylene oxide, and the like. A preferred soil release agent is a copolymer having blocks of terephthalate and polyethylene oxide. More specifically, these polymers are comprised of repeating units of ethylene and/or propylene terephthalate and polyethylene oxide terephthalate at a molar ratio of ethylene terephthalate units to polyethylene oxide terephthalate units of from about 25:75 to about 35:65, said polyethylene oxide terephthalate containing polyethylene oxide blocks having molecular weights of from about 300 to about 2,000 g/mol. The molecular weight of this polymeric soil release agent is in the range of from about 5,000 to about 55,000 g/mol. Another preferred polymeric soil release agent is a crystallizable polyester with repeat units of ethylene terephthalate units containing from about 10% to about 15% by weight of ethylene terephthalate units together with from about 10% to about 50%) by weight of polyoxyethylene terephthalate units, derived from a polyoxyethylene glycol of average molecular weight of from about 300 to about 6,000 g/mol, and the molar ratio of ethylene terephthalate units to polyoxyethylene terephthalate units in the crystallizable polymeric compound is between 2:1 and 6:1. Examples of this polymer include the commercially available materials Zelcon® 4780 (from DuPont) and Milease® T (from ICI). A more complete disclosure of these highly preferred soil release agents is contained in European Patent Application 185,427 to Gosselink, published June 25, 1986. Also useful herein are the soil release agents disclosed in U.S. Patent No. 4,976,879 to Maldonado, et al., issued December 11 , 1990, which describes a soil release agent which may also provide improved antistatic benefits. The soil release agent of U.S. Patent No. 4,956,447 to Gosselink, et al., issued September 11 , 1990, is also useful herein; this patent describes specific preferred soil release agents which contain cationic functionalities. The antimicrobial agent useful herein prevents the growth of bacteria, fungus, and/or mold in the fabric conditioning concentrate and the fabric conditioning composition during storage. As an additional benefit, antimicrobial agents may also provide a disinfecting benefit on the fabric to be treated. The antimicrobial agents useful herein include benzalkonium chloride, glutaraldehyde, and mixtures thereof. These are commonly available from, for example, Alkaquat DMB-451 -50 from Rhone-Poulenc Inc., North American Chemicals, Surfactants & Specialties of Cranbury, New Jersey, U.S.A.; and AQUCAR® Microbiocides from Union Carbide Corporation, of Danbury, Connecticut, U.S.A. An especially preferred antimicrobial agent is KATHON® by Rohm and Haas, Philadelphia, Pennsylvania, U.S.A. This antimicrobial agent is available as either KATHON CG or KATHON CG II. The optical brightener useful herein is commercially available, and may be classified into subgroups, which include, but are not necessarily limited to, derivatives of stilbene, pyrazoline, coumarin, carboxylic acid, methinecyanines, dibenzothiphene-5,5-dioxide, azoles, 5- and 6-membered-ring heterocycles, and other miscellaneous agents. Examples of such optical brighteners are disclosed in "The Production and Application of Fluorescent Brightening Agents", M. Zahradnik, published by John Wiley & Sons, New York (1982). Specific examples of useful optical brighteners are those identified in U.S. Patent 4,790,856, issued to Wixon on December 13, 1988. These optical brighteners include the PHORWHITE™ series of brighteners from Verona. Other optical brighteners disclosed in this reference include: Tinopal UNPA, Tinopal CBS and Tinopal 5BM; available from Ciba-Geigy; Artie White CC and Artie White CWD, available from Hilton-Davis, located in Italy; the 2-(4-stryl-phenyl)-2H-napthol[1 ,2- d]thazoles; 4,4'-bis- (1 ,2,3-triazol-2-yl)-stilbenes; 4,4'-bis(stryl)bisphenyls; and the aminocoumarins. Specific examples of these brighteners include 4-methyl-7- diethyl- amino coumarin; 1 ,2-bis(-venzimidazol-2-yl)ethylene; 1 ,3-diphenyl- phrazolines; 2,5-bis(benzoxazol-2-yl)thiophene; 2-stryl-napth-[1 ,2-d]oxazole; and 2-(stilbene-4-yl)-2H-naphtho- [1 ,2-d]triazole. See also U.S. Patent 3,646,015 to Hamilton, issued February 29, 1972. Anionic optical brighteners are preferred herein. The solvent useful herein lowers the viscosity of the fabric conditioning concentrate, thereby providing it with liquidity and pourability so that it is easier to process, pump, etc. However, the solvent level must be balanced so as to keep the solvent level limited, so as to decrease transportation costs, and yet to provide enough solvent to ensure easy processing. The solvent useful herein is typically water, preferably deionized water or purified water, due to its relatively low cost, availability, safety, and environmental compatibility, but may also be an organic solvent, or preferably is a mixture of water and an organic solvent. A preferred organic solvent includes a low molecular weight alcohol, such as ethanol, propanol, isopropanol or butanol; propylene carbonate; and/or a glycol ether. Useful low molecular weight alcohols also include dihyd c alcohols (e.g., glycol), trihydhc alcohols (e.g., glycerol), and polyhyd c (polyol) alcohols, such as a C2-6 polyhydric alcohol. The solvent is useful in the final fabric conditioning composition at a total level from about 30% to about 95%, preferably from about 50% to about 90%, more preferably from about 65% to about 90%. Water is preferably present in at a level of from about 30% to about 85%, and more preferably from about 50% to about 75% of the fabric conditioning composition. Examples of preferred fabric conditioning actives, and other ingredients useful in fabric conditioning compositions include those disclosed in U.S. Patent 4,062,647 to Storm and Nirschl, issued December 13, 1977; U.S. Patent 4,375,416 to Crisp, et al., issued March 1 , 1983; U.S. Patent 4,291 ,071 to Harris, et al., issued September 22, 1981 ; and PCT Patent Application U.S. 99/15056 to Bryant, et al., filed on July 1 , 1999. In a highly preferred embodiment, the fabric conditioning composition here is a clear, transparent, or translucent fabric conditioning composition. Specific examples of which include those disclosed in U.S. Patent 5,747,443 to Wahl, et al., issued May 5, 1998, and in U.S. Patent Application numbers 08/621 ,019; 08/620,627; 08/620,767; 08/620,513; 08/621 ,285; 08/621 ,299; 08/621 ,298; 08/620,626; 08/620,625; 08/620,772; 08/621 ,281 ; 08/620,514; and 08/620,958, all filed March 22, 1996, and all having the title "CONCENTRATED, STABLE, PREFERABLY CLEAR, FABRIC CONDITIONING COMPOSITION". Such fabric conditioning compositions may be prepared as the fabric conditioning concentrate herein, by decreasing the levels of solvents and by not including such ingredients as chelants, perfumes, etc. For improved stability, the fabric conditioning concentrate typically has a pH (of a 3% solution) of from about 2 to about 5, preferably from about 2 to about 4. Pre-neutralized 1 J-hvdroxyethane diphosphonic acid The pre-neutralized 1 ,1-hydroxyethane diphosphonic acid (pre-neutralized HEDP) is formed by neutralizing 1 ,1-hydroxyethane diphosphonic acid (HEDP; also known as etidronic acid and 1-hydroxyethane-1 J -diphosphonic acid; Chemical Abstracts Registry No. 2809-21-4) with a base or an acid, preferably a strong base or a strong acid, and more preferably with sodium hydroxide or hydrochloric acid, to a (neat) pH of from about 2.0 to about 2.4, preferably from about 2Λ to about 2.4, and more preferably from about 2.2 to about 2.3. Typically, the pH of commercially-available HEDP is about 1.7, but may range to about 7, depending upon the form (e.g., sodium salt) obtained. The pH of the HEDP is then adjusted by adding a base or an acid, until it is within the appropriate range. HEDP has the following structure: OH I O=P— OH I CH 3 C-OH O=P— OH OH The pKi = 1.35 (± 0.08), pK 2 = 2.87 (± 0.01 ), pK 3 = 7.03 (± 0.01 ), and pK 4 = 11.3, while the molecular weight = 206 g/mol. HEDP is available in a variety of forms, such as liquid solution, the di-sodium salt form, the tri-sodium salt form, etc., from, for example, Sigma-Aldrich Japan K.K., Tokyo, Japan, see also the Sigma- Aldrich webpage at: www.sigma-aldrich.com, product no. H 6773; and Albright & Wilson Americas, Richmond, Virginia, U.S.A. Without intending to be limited by theory, it is believed that pre-neutralizing the HEDP adjusts the equilibria between the trisodium and disodium forms. When pre-neutralized to this pH range, the HEDP also serves as a pH buffer which helps maintain the pH of the fabric conditioning composition. This in turn further reduces hydrolysis of the hydrolyzable fabric conditioning active, and significantly reduces phase separation, especially where a hydrolyzable fabric conditioning active contains a fatty acid moiety therein. The pre-neutralized HEDP is typically present at a level of from about 0.05%) to about 5%, preferably from about 0.075% to about 4% of the fabric conditioning composition. Thickener The fabric conditioning composition herein may also contain an optional thickener, which helps to modify the viscosity of the fabric conditioning composition, and may further help to keep the fabric conditioner vesicles (if present) in suspension. The thickener herein is typically a polymeric thickener, preferably a copolymeric thickener. Examples of the thickener useful herein include high molecular weight polyethylene glycols, preferably PEG 4050, and the ACUSOL™ series from Rohm & Haas Company (Philadelphia, Pennsylvania, USA), especially ACUSOL™ 882. The thickener useful herein is typically present in the fabric conditioning composition at a level of from about 0.001 % to about 1 %, preferably form about 0.03%) to about 0.8%. Dye The fabric conditioning composition herein may also contain an optional dye which modifies the aesthetics of the fabric conditioning composition. Dyes useful herein are known in the art, and are easily determined by the formulator. The dye useful herein is typically present in the fabric conditioning composition at a level of from about 0.01 % to about 2%, preferably from about 0.05% to about 1 %. Perfume The fabric conditioning composition herein may also contain an optional perfume which modifies the odor of the fabric conditioning composition. Perfumes useful herein are known in the art, and are easily determined by the formulator. The perfume useful herein is typically present in the fabric conditioning composition at a level of from about 0.01 % to about 10%, preferably from about 0.05% to about 5%. The fabric conditioning concentrate, water, any optional ingredients, and the pre-neutralized HEDP are combined in a mixer to form the fabric conditioning composition. The mixer useful herein is known in the art for agitating and/or mixing liquids until they are homogenized, and/or until a suspension and/or emulsion is formed. The mixer herein may be either a batch mixer, or a continuous mixer, as desired. As no particular mixing conditions are required, any mixer which combines and agitates the fabric conditioning concentrate, water, and the pre-neutralized HEDP, together with any other optional ingredients, is useful herein. The order of addition of the fabric conditioning concentrate, water, and pre-neutralized HEDP useful herein is variable; however, typically water will be added to the mixer first. Furthermore, it is preferred that the pre-neutralized HEDP be added to the water prior to the fabric conditioning concentrate, as this seems to ensure even dispersion of the pre-neutralized HEDP and improved fabric conditioning composition stability. If a thickener is present, it is preferred that the thickener be added to the water before the fabric conditioning concentrate and/or before the pre-neutralized 1 ,1-hydroxyethane diphosphonic acid, and more preferably before the fabric conditioning concentrate and before the pre-neutralized 1 ,1-hydroxyethane diphosphonic acid. The conductivity of the fabric conditioning composition is measured after the fabric conditioning concentrate, water, and the pre-neutralized HEDP are combined and mixed together. Preferably, the conductivity measurement of the fabric conditioning composition is taken as a (neat) conductivity measurement which is conducted after all processing is completed, and immediately prior to the bottling and/or packaging of the fabric conditioning composition. The conductivity may be measured with standard commercially-available ionic strength meters and reference solutions. A highly preferred ionic strength meter is the MPC 227 pH/Conductivity Meter available from Mettler Toledo Company (Switzerland). Typically, about 3 conductivity measurements will be made from each batch or lot of fabric conditioning composition, and the results averaged to find the conductivity. The conductivity of the fabric conditioning composition is from about 700 μS/cm to about 3,000 μS/cm, preferably from about 800 μS/cm to about 2,600 μS/cm, and more preferably from about 900 μS/cm to about 2,500 μS/cm. Without intending to be limited by theory, it is believed that fabric conditioning compositions having a conductivity within these ranges are more stable than products having a conductivity outside of these ranges. Specifically, it is believed that the conductivity of the fabric conditioning composition provides a measurement of the relative amounts of ions inside of softener vesicles, and outside of softener vesicles. Products with conductivities in the ranges described possess an appropriate balance of ions within the softener vesicles to stabilize the fabric conditioning composition and to significantly reduce acid-catalyzed hydrolysis of the hydrolyzable fabric conditioning active. This in turn reduces phase separation caused by release of a fatty acid or alkoxy moiety. The viscosity of the fabric conditioning composition will typically be in the range of less than about 200 cps, preferably from about 10 cps to about 100 cps, as measured at 25 °C, by means of a glass capillary viscometer as set forth in Dow Corning Corporate Test Method CTM0004, dated July 20, 1970. Examples of the invention are set forth hereinafter by way of illustration and are not intended to be in any way limiting of the invention. EXAMPLE 1 A fabric conditioning concentrate having the formula below is prepared in a first manufacturin lant. The fabric conditioning concentrate is shipped to a second manufacturing plant, and stored; this transportation and storage lasts 2 months. 100 g of HEDP (20% active HEDP in solution) having an original pH of 1.7 is pre-neutralized to a pH of 2.2 by the addition of 9.4 g of 32% sodium hydroxide solution. To make the final fabric conditioning composition, water, a thickener, the pre-neutralized HEDP, the fabric conditioning concentrate, perfume, a dye and an antimicrobial agent are then added to a mixer. The weight percentage of each ingredient relative to the fabric conditioning composition, order of addition, and the process ste s are: The fabric conditioning composition (Example 1 ) has a conductivity of about 1700 mS/cm and a pH of 2.5, as measured immediately after being produced. The fabric conditioning composition also has an acceptable viscosity of about 20-22 cps, even after 1 month of storage. No phase separation is noticed. After 3 months of storage, the fabric conditioning composition has no noticeable phase separation, a stable pH, and an acceptable viscosity. In contrast, comparative fabric conditioning composition A is formed. Composition A is identical to Example 1 , except that Composition A adds 0.2% thickener, and HEDP which is not pre-neutralized (i.e., has a pH of 1.7) as the final step. The composition has an ionic strength of 731 μS/cm. Composition A has an initial viscosity of 114 cps, which rises to 400-1225 cps (depending upon storage temperature), after 2 weeks. The initial pH is 2.2, and drops to 1.9-2.1 (depending upon storage temperature), after 2 weeks. EXAMPLE 2 The fabric conditioning composition of Example 1 is formed with preneutralized HEDP, except that 0.1 % thickener is added, and the pH of the fabric conditioning composition is 2.2. The fabric conditioning composition has an acceptable viscosity, even after 3 months of storage. After 6 months of storage, no phase separation is noticed.

Claims: WHAT IS CLAIMED IS: 1. A process for forming a fabric conditioning composition comprising the steps of: A. providing a fabric conditioning concentrate comprising a hydrolyzable fabric conditioning active; B. providing water; C. providing pre-neutralized 1 ,1-hydroxyethane diphosphonic acid preneutralized to a pH of from about 2.0 to about 2.4; and D. combining the fabric conditioning concentrate, water, and the preneutralized 1 ,1-hydroxyethane diphosphonic acid in a mixer to form a fabric conditioning composition, wherein the conductivity of the fabric conditioning composition is from about 700 μS/cm to about 3,000 μS/cm. 2. The process of Claim 1 , further comprising the steps of providing a thickener, and combining the thickener, the fabric conditioning concentrate, water, and the pre-neutralized 1 ,1-hydroxyethane diphosphonic acid in a mixer to form a fabric conditioning composition. 3. The process of Claim 1 , wherein the hydrolyzable fabric conditioning active comprises a fatty acid moiety. 4. The process of Claim 1 , wherein the pH of the pre-neutralized 1 ,1- hydroxyethane diphosphonic acid is from about 2.1 to about 2.4. 5. The process of Claim 1 , wherein the conductivity is from about 800 μS/cm to about 2,600 μS/cm. 6. The process of Claim 1 , wherein the pre-neutralized 1 ,1-hydroxyethane diphosphonic acid is added to the water before the fabric conditioning concentrate. 7. The process of Claim 2, wherein the thickener is added to the water before the fabric conditioning concentrate and before the pre-neutralized 1 ,1-hydroxyethane diphosphonic acid. 8. The process of Claim 6, wherein the pre-neutralized 1 ,1-hydroxyethane diphosphonic acid is added to the water before the fabric conditioning concentrate. 9. A fabric conditioning composition as formed by the process of Claim 1. 0. The composition of Claim 9, wherein the fabric conditioning concentrate is from about 10% to about 70% of the fabric conditioning composition, wherein the water is from about 30% to about 85% of the fabric conditioning composition, and wherein the pre-neutralized 1 ,1- hydroxyethane diphosphonic acid is from about 0.05% to about 5% of the fabric conditioning composition.

Inventors: DY AIMEE GO, FORD FRANCIS CORNELIO, MIRASOL MARIA AMELITA GONZALES, PORDAN MARIA VICTORIA TAN, DY, AIMEE, GO, FORD, FRANCIS, CORNELIO, MIRASOL, MARIA, AMELITA, GONZALES, PORDAN, MARIA, VICTORIA, TAN
Applicants: DY AIMEE GO, FORD FRANCIS CORNELIO, MIRASOL MARIA AMELITA GONZALES, PORDAN MARIA VICTORIA TAN, PROCTER & GAMBLE, DY, AIMEE, GO, FORD, FRANCIS, CORNELIO, MIRASOL, MARIA, AMELITA, GONZALES, PORDAN, MARIA, VICTORIA, TAN, THE PROCTER AND GAMBLE COMPANY
Application year: 2000
Main classification: C11D11
IPC codes: C11D3, C11D11