US 3562169 A
Description (OCR text may contain errors)
United States Patent O 3,562,169 DETERGENT COMPOSITIONS CONTAINING OLI- GOMERIC ESTER CHAIN CONDENSATES OF ETHANE 1 HY DROXY 1,1 DIPHOSIHONIC ACID AS BUILDERS James B. Prentice, Batesville, Ind., assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio No Drawing. Filed Dec. 23, 1968, Ser. No. 786,372 Int. Cl. Clld 3/36 US. Cl. 252-152 5 Claims ABSTRACT OF THE DISCLOSURE Built detergent compositions containing an organic syn thetic detergent and a builder which is an oligomeric ester chain condensate of ethane-l-hydroxy-l,l-diphosphonic acid in a proportion of detergent to builder of 5:1 to about 1:20, by weight.
FIELD OF THE INVENTION This invention relates to build detergent compositions which are especially useful in household laundry situations. Built detergent compositions have many uses, however, including dishwashing and other household washing and cleaning applications such as washing soiled walls and floors.
The use of builder compounds as adjuncts to soap and synthetic detergents is widespread. The property of some materials to improve the cleaning levels of detergent compounds is a well-known phenomenon. Not withstanding the fact that this property is widely appreciated in the prior art, the exact behavior and mechanics of how builders perform and function still are not fully understood. A set of criteria does not exist which would permit one to predict which compounds possess significant builder properties.
Builder compounds are thought to have some effect on such diverse aspects of detergency as stabilization of soil suspension, emulsification of soil particles, the surface activity of aqueous solutions, foaming or suds-producing characteristics of washing solutions, peptization of soil agglomerates, neutralization of acid soil, and the inactivation of mineral constituents present in the washing solution (so-called sequestering or water softening). This list is not exclusive since other described properties of builder compounds are known. The point is that no general basis has been found either as regards physical properties or chemical structure by which one might with certainty predict the suitability of chemical materials as builders for detergent compositions.
The known compounds which have been found useful as builders can be described as being of the classes of inorganic and organic alkaline builder salts. An example of the inorganic type is sodium tripolyphosphate which is perhaps the most widely known and commercially used builder. Other examples of inorganic alkaline builder salts are sodium pyrophosphate which is also commercially used as well as other alkali metal carbonates, borates, phosphates, silicates and the like.
Alkali metal salts of nitrilotriacetic acid, ethylenediaminetetraacetic acid, ethane-l-hydroxy 1,1 diphosphonic acid, and ethane-l-hydroxy 1,1,2 triphosphonic acid are examples of known organic alkaline builders.
It is common to employ mixtures of such organic and inorganic compounds in commercially available built detergent compositions. Each of the known builder compounds in both the inorganic and organic classes have certain advantages and disadvantages. The need for and interest in providing suitable alternatives and replacements ICQ for known builders underscores continued research and development for improved builder compounds.
SUMMARY OF THE INVENTION This invention relates to a new class of organophosphorus compounds which are oligomeric ester chain condensates of ethane-l-hydroxy-l,l-diphosphonic acid. More especially, it relates to the use of such materials in combination with organic synthetic detergents to provide effective built detergent compositions. The oligomeric ester chain condensates which are useful in the present invention are believed to be heretofore unknown materials. For this reason, they are the subject of a copending, commonly assigned patent application Ser. No. 786,371 filed Dec. 23, 1968 which is being concurrently filed with the present application by James B. Prentice as Oligomeric Ester Chain Condensates of Ethane 1 Hydroxy-1,1-Diphosphonic Acid. Although condensates of ethane-1- hydroxy-1,1-diphosphonic acid have been previously known, such as those described in US. Pat. 3,387,024 and US. Pat. 3,400,151, it is believed that the oligomeric ester chain condensates described herein are the first condensates which contain ester bonds, C-OP bonds.
It is a primary object of this invention to provide a 5 new and improved class of builder compounds which are oligomeric ester chain condensates of ethane-l-hydroxy- 1,1-diphosphonic acid. The present invention pertains to detergent compositions comprising a water-soluble organic synthetic detergent and a builder selected from the newly discovered class of builder compounds described herein.
DETAILED DESCRIPTION OF THE INVENTION l P OiM2 OM CH3 wherein each M is hydrogen, alkali metal, ammonium, alkylammonium, hydroxyalkyl ammonium, amine, alkylamine, or hydroxyalkylamine; the alkyl and hydroxyalkyl group each having from 1 to about 4 carbons; R is hydrogen or acetyl; and n has a numerical value in the range of l to about 16, the proportion of said detergent to said builder being in the range of from about 5 :1 to about 1:20, by weight. Preferably, the proportion of said organic detergent to the oligomeric ester builder should be in the range of from about 2:1 to about 1:10.
In the preceding formula, suitable alkali metals are sodium, posassium and lithium. Illustrative examples of alkyl ammonium cations are monomethylammoniurn, diethylammonium, tripropylammonium, and tetrabutylammonium. Illustrative examples of hydroxyalkylammonium cations are hydroxymethylammonium, hydroxyethylammonium, 2 hydroxypropylammonium, and 2 hydroxybutylammonium. Illustrative examples of alkylamine are mono-, di-, and trialkylamines including methylamine, diethylamine, and tripropylamine. Illustrative examples of mono(hydroxymethyl)amine are di(hydroxymethyl) amine, tri(hydroxyethyl)amine.
The numerical value for n is preferably in the range of 2 to 12. Due to the complex nature of the oligomeric ester chain condensate, it is difficult to determine exact values for n. This point is discussed below.
Fully neutralized as well as partially neutralized salts are contemplated. As described below, such salts can be prepared by merely neutralizing the acid with an appropriate base compound.
The novel builder compounds can be prepared by any satisfactory process. One satisfactory method is that described in detail in the copending patent application referred to above. That copending patent application is incorporated herein by reference.
The process involves a reaction between phosphorous acid and acetic anhydride. The molar proportion of these reactants should be in the range of from about 1:3 to about 1:20, phosphorous acid to acetic anhydride. An excess of the acetic anhydride has been discovered to enhance the recovery of the oligomeric ester. The oligomeric ester chain condensate formed by the reaction is insoluble in acetic anhydride and therefore readily precipitates out of solution. Recovery is thereby enhanced. Molar proportions in excess of 1:20 phosphorous acid to acetic anhydride can be used but without any apparent advantage.
This reaction can be controlled to prepare oligomeric esters which contain monomeric units in the lower range of the numerical value given above for n or, alternatively, to prepare oligomeric esters containing monomeric units in the upper portion of the range from 1 to 16. In any case, the reaction product comprises a mixture of condensates having different chain lengths. Moreover, it is highly improbable that any molecular weight determination can be obtained with desired preciseness. For this reason, the value for 'n is an estimate determined by applying the best and most accurate analytical means available. The means for controlling this reaction is described more fully below.
The reaction temperature is in the range of about C. to about 80 C. Depending upon whether short chain condensates or longer chain condensates are desired, the temperature should be adjusted as explained below. The reaction generally takes from 5 minutes to about 48 hours. Again, the duration of the reaction must take into consideration the temperature at which the reaction is run and whether shorter or longer chain condensates are desired.
By operating with the above-prescribed reaction conditions, it is possible to control the reaction product which is prepared. For example, by running the reaction at a temperature of about 40 C. for about 30 minutes or about 5 minutes at 80 C., cooling the reaction mixture to a temperature in the range of from about 0 C. to about 30 C. and digesting the reaction mixture at these lower temperatures for about 30 minutes to about 48 hours, a precipitate form which is a relatively longer chain oligomeric esters of ethane-l-hydroxy-l,l-diphosphonic acid. There is no limit to the length of the digestion period. Periods longer than 48 hours can be used if found necessary to precipitate the ester. This again will depend to a large extent upon the reaction temperature employed.
In another process embodiment when the reaction tem perature is held at about 60 C. a precipitate begins to form within about 20 minutes. Under these conditions, the oligomeric ester chain condensate of ethane-l-hydroxy-l, l-diphosphonic acid formed contains relatively fewer monomeric units of ethane-l-hydroxy-l,l-diphosphonic acid.
The reaction product under the prescribed conditions is comprised of a mixture of oligomeric esters having from 2 to about 16 monomeric units. Depending upon the reaction conditions, the reaction product represents a mixture of oligomeric esters. Factors which are involved and which determine the composition of the reaction mixture are the insolubility of the condensate in the reaction medium which hinders growth of long chains and the degradative effects of acetic acid which tends, especially at higher temperatures, to break down the oligomeric ester to other undesired by-products.
The compounds of the present invention are the only condensates of ethane-l-hydroxy-l,l-diphosphonic acid which are known to contain a mixed anhydride (COP) bond. The oligomeric ester chain condensates of this invention are unstable in the reaction mixture, and it is for this reason that a solvent is employed to terminate the reaction with the formation of the desired chain condensates. In the preceding discussion it has been pointed out that a large excess of acetic anhydride should be used. The reason for this is that the acetic anhydride is a suitable solvent for the reaction and, at the same time, the oligomeric ester chain condensates are insoluble in acetic anhydride. As a result, the desired oligomeric esters precipitate out of solution and can readily be recovered.
The stoichiometry of the reaction between phosphorous acid and acetic acid anhydride is 1:1 on a molar basis.
The precipitate which forms during the reaction is an amorphous solid reaction product.
The P MR spectra for the oligomeric ester chain condensates of this invention display multiplet centered at A=-15 to -16 parts per million. This MR spectra eliminates the prospect of a P-OP bonded condensate.
The possibility of branching along the chain is probable but only to a limited extent. For this reason, the oligomeric esters have at times been previously referred to as primarily chain condensates.
The carbon at the end of the chain condensate can contain either a hydroxyl group or an acetyl group as noted in the general formula given above.
As noted above, the oligomeric ester chain condensates of ethane-Lhydroxy-l,l-diphosphonic acid of the present invention are distinguished from previously known condensates in at least two ways. The first is the presence of a mixed anhydride bond (i.e., a C-O-P rather than a CO-C or PO-P bond). Secondly, the compounds of the present invention are the only known condensates of ethane l hydroxy 1,1 diphosphonic acid which are larger than a dimer.
One of the major concerns in practicing the reaction described above is the formation of acetic acid as a natural by-product when acetic anhydride is reacted with phosphorous acid. The acetic acid can extensively degrade the desired oligomeric ester chain condensates. It can be appreciated that higher acetic anhydride ratios are desirable in order to force out of solution the desired oligomeric ester chain condensates and, by the same token, higher acetic acid anhydride ratios dilute and therefore reduce the detrimental acetic acid attack. The reaction conditions should be chosen which best reduce acetic acid attack. Two Ways of doing this as mentioned above is by lowering the reaction temperature and by diluting the acetic acid. An alternative way would be by adding ketone to an acetic anhydride phosphorus reaction mixture which would react with the acetic acid formed from the reaction to make acetic anhydride.
The molecular weights of the builder compounds of the present invention are in the range of from about 500 to about 4000 calculated as the sodium salts. Within the preferred range, the molecular Weights are within a range of about 700 to about 3000. These values are related to the numerical values of it presented above.
The following examples are presented to demonstrate a method for preparing the builder compounds which are an essential part of the present invention.
Example I Phosphorous acid (416 g., 5.0 moles) was dissolved in acetic anhydride (4 1., 42.4 moles) and the reaction mixture heated to C. over a 20 minute period. The reaction temperature of 50 C. was maintained for 20 minutes, at which time a cooling bath was applied and the reaction mixture cooled to 22 C. White solids formed at this point. The slurry was then digested for 20 hours, the solid product recovered by filtration and washed free of mother liquor with ethyl ether and dried. The total yield of product was 400 g. The reaction product was comprised of oligomeric ester chain condensation of ethane-l-hydroxy-l,l-diphosphonic acid having a molecular weight in the range of from about 500 to about 4000.
The acid product was added slowly, and with good stirring, to 280 g. of NaHCO dissolved in 2:5 1. of Water.
The final pH of the solution was about pH 5. The clear aqueous salt solution was then divided by fractional precipitation. Increments of a non-solvent (methanol and iso-propanol) were added and the solids formed were filtered off before the next increment was added. A total of six solid fractions were obtained. Data for the six demonstration described below to show the effect of average molecular weight on the properties of the oligomeric chain condensate of EHDP. Fraction No. 1 corresponds to Oligomer (A) and Fraction No. 6 corresponds to Oligomer (B) in the description below of the Swatch-Dip test. Several of these fractions also were used in the detergency demonstration described below.
Example II Phosphorous acid (100 g., 1.2 moles) was dissolved in acetic anhydride (1 1., 10.6 moles) and the mixture heated to 55 C. The temperature of 55 C. was maintained until a solid precipitate had formed (ca. 20 min.) and for an additional minutes. The slurry was cooled to room temperature, digested 10 minutes, then filtered and washed free of mother liquor with ethyl ether. The yield of by-product was 5 8 g. As judged from thin layer chromatography, this sample was similar to Fraction No. 6 in Example I. It was of a shorter average chain length than the product of Example III.
Example III Phosphorous acid (41 g., 0.5 mole) was dissolved in acetic anhydride (400 cc., 4.2 moles) at room temperature. The clear solution was cooled to C. and-that temperature maintained. After 24 hours a precipitate had formed, which was digested for days at 15 C., then filtered, washed free of mother liquor with ethyl ether, and dried. The yield was 42 g. of solid product. As judged from thin layer chromatography, this product was similar to Fraction No. 1 of Example I. It was of a longer average chain length than the product of Example 11.
The water-soluble organic synthetic detergents with which the builder compounds described herein can be used include anionic, nonionic, ampholytic and zwitterionic detergent compounds, or mixtures of compounds selected from these general classes of detergents. Each of these classes is illustrated below:
(A) Anionic soap and non-soap synthetic detergents- This class of detergents includes ordinary alkali metal soaps such as the sodium, potassium, ammonium and alkylolammonium salts of higher fatty acids containing from about 8 to about 24 carbon atoms and preferably from about 10 to about 20 carbon atoms. Suitable fatty acids can be obtained from natural sources such as, for instance, from plant or animal esters (e.g., palm oil, coconut oil, babassu oil, soybean oil, castor oil, tallow, whale and fish oils, grease, lard, and mixtures thereof). The fatty acids also can be synthetically prepared (e.g., by the oxidation of petroleum, or by hydrogenation of carbon monoxide by the Fischer-Tropsch process). Resin acids are suitable such as rosin and those resin acids in tall oil. Napthenic acids are also suitable. Sodium and potassium soaps can be made by direct saponification of the fats and oils or by the neutralization of the free fatty acids which are prepared in a separate manufacturing process. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium tallow and coconut soap.
This class of detergents also includes water-soluble salts, particularly the alkali metal salts of organic sulfuric reac tion product having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a sulfonic acid or sulfuric acid ester radical. (Included in the term alkyl is the alkyl portion of higher acyl radicals.) Examples of this group of synthetic detergents which form a part of the preferred built detergent compositions of the present invention are the sodium or potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (C C carbon atoms) produced by reducing the glycerides of tallow or coconut oil; sodium or potassium alkyl benzene sulfonates, in which the alkyl group contains from about 9 to about 15 carbon atoms, in straight chain or branched chain configuration, especially those of the type described in United States Letters Patents Nos. 2,220,099 and 2,477,- 383; sodium alkyl glyceryl ether sulfonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates; sodium or potassium salts of sulfuric acid eters of the reaction product of one mole of a higher fatty alcohol (e.g., tallow or coconut oil alcohols) and about 1 to 6 moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate with about 1 to about 10 units of ethylene oxide per molecule and in which the alkyl radicals contains about 8 to about 12 carbon atoms.
Additional examples of anionic non-soap synthetic detergents which come within the terms of the present invention are the reaction product of fatty acids esterified with isethionic acid and neutralized with sodium hydroxide where, for example, the fatty acids are derived from coconut oil; sodium or potassium salts of fatty acid amide or methyl tauride in which the fatty acids, for example, are derived from coconut oil. Other anionic synthetic detergents of this variety are set forth in United States Letters Patents 2,486,921; 2,486,922; and 2,396,278.
Still other anionic synthetic detergents include the class designated as succinamates. This class includes such surface active agents as disodium N-octadecylsulfo succinamate; tetrasodium N (1,2-dicarboxyethyl)-N-octadecylsulfo-succinamate; diamyl ester of sodium sulfosuccinic acid; dihexyl ester of sodium sulfosuccinic acid; dioctyl ester of sodium sulfosuccinic acid.
Anionic phosphate surfactants are also useful in the present invention. These are surface active materials having substantial detergent capability in which the anionic solubilizing group connecting hydrophobic moieties is an oxy acid of phosphorus. The more common solubilizing groups, of course, are SO H, SO H, and CO H. Alkyl phosphate esters such as (RO) PO H and ROPO H in which R represents an alkyl chain contain ing from about 8 to about 20 carbon atoms are useful.
These esters can be modified by including in the molecule from one to about 40 alkylene oxide units, e.g., ethylene oxide units. Formulate for these modified phosphate anionic detergents are in which R represents an alkyl group containing from about 8 to 20 carbon atoms, or an alkylphenyl group in which the alkyl group contains from about 8 to 20 carbon atoms, and M represents a soluble cation such as hydro- 7 gen, sodium, potassium, ammonium or substituted ammonium; and in which n is an integen from 1 to about 40.
A specific anionic detergent which has also been found excellent for use in the present invention is described more fully in the US. patent application of Phillip F. Pilaumer and Adriaan Kessler, Ser. No. 423,364 filed Jan. 4, 1965 now abandoned. This detergent comprises by Weight from about 30% to about 70% of Component A, from about 20% to about 70% of Component B, and from about 2% to about 15% of Component C, wherein:
(a) Said Component A is a quaternary mixture of double-bond positional isomers of Water-soluble salts of alkene-l-sulfonic acids containing from about 10 to about 24 carbon atoms, said mixture of positional isomers including by weight about 10% to about 25% of an alphabeta unsaturated isomer, about 30% to about 70% of a beta-gamma unsaturated isomer, about 5% to about 25% of a gamma-delta unsaturated isomer, and about 5% to about of a delta-epsilon unsaturated isomer;
(b) Said Component B is a mixture of water-soluble salts of bifunctionally-substituted sulfur-containing saturated aliphatic compounds containing from about 10 to about 24 carbon atoms, the functional units being hydroxy and sulfonate radicals and the sulfonate radical always being on the terminal carbon and the hydroxyl radical being attached to a carbon atom at least two carbon atoms removed from the terminal carbon atoms; and
(c) Said Component C is a mixture of water-soluble salts of highly polar saturated aliphatic compounds, each having two sulfur-containing moieties, one of which must be a sulfonate group attached to the terminal carbon atom and the other moiety selected from the group consisting of sulfonate and sulfate radicals attached to a carbon atom at least two carbon atoms removed from the terminal carbon atom, said compounds containing from about 10 to about 24 carbon atoms.
(B) Nonionic synthetic detergents.-Nonionic synthetic detergents may be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a watersoluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.
For example, a well known class of nonionic synthetic detergents is made available on the market under the trade name of Pluronic. These compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule which, of course, exhibits water insolubility, has a molecular weight of from about 1500 to 1800. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a Whole and the liquid character of the product is retained up to the point where polyoxyethylene content is about 50% of the total weight of the condensation product.
Other suitable nonionic synthetic detergents include:
(1) The polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 5 to 25 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octene, or nonene, for example.
(2) Those derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine. For example, cornpounds containing from about 40% to about polyoxyethylene by weight and having a molecular weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight of the order of 2,500 to 3,000, are satisfactory.
(3) The condensation product of aliphatic alcohols having from 8 to 22 carbon atoms, in either straight chain or branched chain configuration, with ethylene oxide, e.g., a coconut alcohol-ethylene oxide condensate having from 5 to 30 moles of ethylene oxide per mole of coconut alcohol, the cconut alcohol fraction having from 10 to 14 carbon atoms.
(4) Nonionic detergents include nonyl phenol condensed with either about 10 or about 30 moles of ethylene oxide per mole of phenol and the condensation products of coconut alcohol with an average of either about 5.5 or about 15 moles of ethylene oxide per mole of alcohol and the condensation product of about 15 moles of ethylene oxide with one mole of tridecanol.
Other examples include dodecylphenol condensed with 12 moles of ethylene oxide per mole of phenol; dinonylphenol condensed with 15 moles of ethylene oxide per mole of phenol; dodecyl mercaptan condensed with 10 moles of ethylene oxide per mole of mercaptan; bis- (N- 2-hydroxyethyl) lauramide; nonyl phenol condensed with 20 moles of ethylene oxide per mole of nonyl phenol; myristyl alcohol condensed with 10 moles of ethylene oxide per mole of myristal alcohol; lauramide condensed with 15 moles of ethylene oxide per mole of lauramide; and di-isooctylphenol condensed with 15 moles of ethylene oxide.
(5) A detergent having the formula R R R N O (amine oxide detergent) wherein R is an alkyl group containing from about 10 to about 28 carbon atoms, from 0 to about 2 hydroxy groups and from O to about 5 ether linkages, there being at least one moiety of R which is an alkyl group containing from about 10 to about 18 carbon atoms and 0 ether linkages, and each R and R are selected from the group consisting of alkyl radicals and hydroxyalkyl radicals containing from 1 to about 3 carbon atoms;
Specific examples of amine oxide detergents include:
dimethyldodecylamine oxide dimethyltetradecylamine oxide ethylmethyltetradecylamine oxide cetyldimethylamine oxide dimethylstearylamine oxide cetylethylpropylamine oxide diethyldodecylamine oxide diethyltetradecylamine oxide dipropyldodecylamine oxide bis- 2-hydroxyethyl dode cylamine oxide bis-(2-hydroxyethyl)-3-dodecoxy-l-hydroxypropyl amine oxide (2-hydroxypropyl)methyltetradecylamine oxide dimethyloleyamine oxide dimethyl- 2-hydroxydodecyl amine oxide and the corresponding decyl, hexadecyl and octadecyl homologs of the above compounds.
(6) A detergent having the formula R R R P 0 (phos phine oxide detergent) wherein R is an alkyl group containing from about 10 to about 28 carbon atoms, from 0 to about 2 hydroxy groups and from 0 to about 5 ether linkages, there being at least one moiety of R which is an alkyl group containing from about 10 to about 18 carbon atoms and 0 ether linkages, and each of R and R are selected from the group consisting of alkyl radicals and hydroxyalkyl radicals containing from 1 to about 3 carbon atoms.
Specific examples of the phosphine oxide detergents include:
dimethyldodecylphosphine oxide dimethyltetradecylphosphine oxide ethylmethyltetradecylphosphine oxide cetyldimethylphosphine oxide dimethylstearylphosphine oxide cetylethylpropylphosphine oxide diethyldodecylphosphine oxide diethyltetradecylphosphine oxide dipropyldodecylphosphine oxide bis- (hydroxymethyl) dodecylphosphine oxide bis- 2-hydroxyethyl dodecylphosphine oxide (Z-hydroxypropyl)methyltetradecylphosphine oxide dimethyloleylphosphine oxide, and
dimethyl- (Z-hydroxydodecyl phosphine oxide and the corresponding decyl, hexadecyl, and octadecyl homologs of the above compounds.
(7) A detergent having the formula T R -S-R=' (sulfoxide detergent) wherein R is an alkyl radical containing from about 10 to about 28 carbon atoms, from 0 to about ether linkages and from 0 to about 2 hydroxyl substituents at least one moiety of R being an alkyl radical containing 0 ether linkages and containing from about to about 18 carbon atoms, and wherein R is an alkyl radical containing from 1 to 3 carbon atoms and from one to two hydroxyl groups.
octadecyl methyl sulfoxide dodecyl methyl sulfoxide tetradecyl methyl sulfoxide 3-hydroxytridecyl methyl sulfoxide 3-methoxytridecyl methyl sulfoxide 3-hydroxy-4-dodecoxybutyl methyl sulfoxide octadecyl 2-hydroxyethyl sulfoxide dodecylethyl sulfoxide (C) Ampholytic synthetic detergents.Ampholytic synthetic detergents can be broadly described as derivatives of aliphatic or aliphatic derivatives of heterocyclic secondary and tertiary amines, in which the aliphatic radical may be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and at least one contains an anionic watersolubilizing group, e.g., carboxy, sulfo, sulfato, phosphato, or phosphono. Examples of compounds falling within this definition are sodium 3-(dodecylamino)-propionate 0 Ci2 I I-CH2CH2( 3 ONa sodium 3- (dodecylamino propanel-sulfonate H C 1211251 1 CN2CH2 OHzS OaWa sodium 2- (dodecylamino) ethyl sulfate H GigHgfilL'CHQCHgO S OaNa sodium 2- (dimethylamino) octadecanoate 0 ClmlImCliC1126) ONa H CNCHs disodium 3 (N-carboxymethyl-dodecylamino)propane-1- sulfonate CH2CH2CH2S OaNa o C En 0 Na disodium 2- (oleylamino ethyl phosphate 0 C 18113515 CHzCIIgO 1i (ONa) 2 disodium 3-(N-methyl-hexadecylamino) propyl-l-phos honate 1 T C1eHs5NCH2CHzCH2P(0Na)2 disodium octadecyl-iminodiacetate ClBH37H (CHfl l ONa) 2 sodium l-carboxymethyI-Z-undecyl-irnidazole disodium 2 [N (2-hydroxyethyl)octadecylamino] ethyl phosphate 1! CH2CH2O P (ONEDZ is sv CHzCHaOH and sodium N,N-bis(Z-hydroxyethyl)-2-sulfato-3-dodecoxypropylamine OSOzNa o 2H2 0omofiommcmomomg (D) Zwitterionic synthetic detergents.-Zwitterionic synthetic detergents can be broadly described as derivatives of aliphatic quaternary ammonium and phosphonium or tertiary sulfonium compounds, in which the cationic atom may be part of a heterocyclic ring, and in which the aliphatic radical may be straight chain or branched, and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms, and at least one aliphatic substituent contains an anionic water-solubilizing group, e.g., carboxy, sulfo, sulfato, phosphato, or phos phono. Examples of compounds falling within this definition are 2-N,N-dimethyl N -heXadecyl-ammonio)-2- hydroxypropane-l-sulfonate CH3 OH CmHnNCH2( JHOH1S 03 3-(N,N-dimethyl N hexadecylammonio)propane-l-sulfonate CH3 o16r-I33N o112o11 oms on 2-(N,N-dimethyl-N-dodecylammonio)acetate E 11 C1zHg NCH2CO 3-(N,N-dimethyl-N-dodecylammonio)propionate E n CrzHz N-CHgCHgC-O 2-(N,N-dimethyl-N-octadecylammonio) -ethyl sulfate 2- (trimethylammonio ethyl dodecylphosphonate 1 1 ethyl 3 (N,N-dimethyl-N-dodecylammonio)propylphosphonate 3-(P,P -dimethyl P dodecylphosphonio) propane-1- sulphonate ClZHQiP-CHgCIIzCHfl s 03 2-(S-methyl S tert hexadecyl-sulfonio)ethane 1 sulfonate 3- S-methyl-S-dodecylsulfonio -propionate CI'Ig I u e 012112568; CHzCI'IzC- 0 sodium 2 (N,N dimethyl N dodecylammonio)ethyl phosphonate CH; O ONa I ll 0121125NCH1GIIQ1 e 0113 0 4-(S-methyl-S-tetradecylsulfonio)butyrate I ll 9 C 4H29eb3CH CHzCH CO 1- 2-hydroxyethyl) -2-undecyl-imidazoliuml-acetate N-oIIzoI-Izo1-I o (Iliad-o 2- (trimethylammonio -octadecanoate O owrrworr i 3o and 3-(N,N bis (2 hydroxyethyl) N octodecylammonio)-2-hydroxy-propane-l-sulfonate.
CHZCH OH 018N37N-0H20H0H2S03 CH CHzOH Some of these detergents are described in the following US. Pats. 2,129,264; 2,178,353; 2,774,786; 2,813,898; and 2,828,332.
A detergent composition prepared according to the present invention contains as essential ingredients (a) a detergent ingredient and (b) a builder ingredient. In simplest terms, a composition can contain a single detergent com pound and a single builder compound. On the other hand, it frequently is desirable to formulate a detergent composition in which the detergent ingredient consists of mixtures of detergent compounds selected from the foregoing classes. Thus, for example, the active ingredient can consist of a mixture of two or more anionic detergents; or a mixture of an anionic detergent and a nonionic detergent; or, by way of anotehr example, the active detergent can be a ternary mixture of two anionic detergents anda zwitterionic detergent.
The part of the complete formulation that functions as a builder can likewise be composed of a mixture of builder compounds. For example, the builder compounds described herein can be mixed together with other watersoluble inorganic alkaline builder salts such as sodium tripolyphosphate or potassium pyrophosphate or potassium pyrophosphates or a water-soluble organic builder salt such as Water-soluble salts of nitrilotriacetic acid, ethylenediaminetetraacetic acid, ethane-l-hydroxy-1,1-diphosphonic acid. Still further, the builder component of a complete formulation can consist of ternary mixtures of these several types of builder compounds.
Water-soluble inorganic alkaline builder salts which can be used in this invention in combination with the novel oligomeric ester chain condensates of ethane-l-hydroxy-1,1-diphosphonates are alkali metal carbonates, borates, phosphates, polyphosphates, bicarbonates and silicates. Ammonium and substituted ammonium salts of these materials can also be used. Specific examples of suitable salts are sodium tripolyphosphate, sodium carbonate, sodium tetraborate, sodium and potassium pyrophosphate, sodium and ammonium bicarbonate, potassium tripolyphosphate, sodium hexametaphosphate sodium sesquicarbonate, sodium orthophosphate and potassium bicarbonate.
Examples of suitable organic water-soluble organic alkaline sequestrant builder salts whichcan be mixed with the ester chain condensates of ethane-1-hydroxy1,1-diphosphonate compounds of this invention are alkali metal (sodium, potassium, lithium), ammonium or substituted ammonium, aminopolycarboxylates, e.g., the above mentioned sodium and potassium ethylenediaminetetraacetate, sodium and potassium N-(2-hydroxyethyl)-ethylenediaminetriacetates, sodium and potassium nitrilotriacetates and sodium, potassium and triethanolammonium N-(2- hydroxyethyl)-nitrilodiacetates. The alkali metal salts of phytic acid, e.g., sodium phytate, are also suitable as organic alkaline sequestrant builder salts. Certain other organic builders which can be used in admixture herewith are water-soluble salts of ethane-l-hydroxy-l,l-diphosphonic acid, methylene diphosphonic acid, and the like.
The builder mixtures taught herein are highly eflicient, and, in general, can be used to permit the attainment of equal detergency with a smaller total quantity of builder in relation to the total quantity of detergent ingredient.
The detergent compositions of the present invention can be formulated and prepared into any of the several commercially desirable solid and liquid forms including, for example, granules, flakes, tablets, and Water-based and alcohol-based liquid detergents, emulsions and the like. According to one embodiment of the present invention, solid detergent compositions are prepared containing a detergent ingredient (single detergent or a mixture of detergents) and a builder ingredient (single builder or a mixture of builders) in the by weight ratio (detergent to builder) of about 2:1 to about 1:10; and preferably from about 1:1 to about 1:6. A special embodiment of this invention is a liquid detergent composition containing a detergent and a builder in the by weight ratio (detergent to builder) of 3:1 to about 1:10; preferably 2:1 to about 1:3. Potassium salts are especially useful in liquid formulations due to the increased solubility characteristics of potassium over sodium.
Liquid detergent compositions containing builders are usually water based or have a mixture of water and al cohol in the liquid vehicle. Such liquid vehicles can be satisfactorily employed in formulating a composition according to the present invention. Accordingly, a sample liquid detergent composition of this invention consists essentially of a detergent ingredient (a single detergent or a mixture of detergents) and an oligomeric ester chain condensate of ethane-l-hydroxy-l,l-diphosphonate containing builder ingredient (either as a single builder or in admixture with other builders), with the balance of the composition to being a liquid vehicle such as Water or a water alcohol mixture, and the like.
The detergent compositions of the present invention provide best results when used in a washing solution which has a pH in the range of from about 8 to about 12.
Within this broad range, it is preferred to operate at a pH of from about 8 to 11. The detergent and the builder can be formulated to provide a pH in this range. Usually the detergent composiiton itself has a pH in the range of 8 to 12. If desired, other alkaline materials can be added to the complete formulation to provide a pH in the required range. A preferred embodiment is to have the detergent composition whether in solid or liquid form provide a pH in the aforementioned ranges at the usual recommended usage levels.
In a finished detergent formulation, other materials can be present which make the product more effective or more aesthetically attractive. The following are mentioned by way of example. A water-soluble sodium carboxymethyl cellulose can be added in minor amounts to inhibit soil redeposition. Tarnish inhibitors such as benzotriazole or ethylenethiourea can also be added in amounts up to about 3%. Fluorescers, and brighteners, enzymes, perfumes, coloring agents, while not per se essential in the compositions of this invention, can be added in minor amounts. As already mentioned, an alkaline material or alkali such as sodium or potassium hydroxide can be added as supplementary pH adjusters. Other usual addi-.
tives include sodium sulfate, sodium carbonate, water, and
the like. Corrosion inhibitors are also frequently used. Water-soluble silicates are highly elfective corrosion inhibitors and can be added if desired at levels of from about 3% to about 8% by weight of the total composition. Alkali metal, preferably potassium and sodium silicates, are preferred having a weight ratio of SiO :M O of from about 1.0:1 to 2.8:1. (M refers to sodium or potassium.) Sodium silicate having a ratio of SiO :Na O of from about 1.611 to 2.45:1 is especially preferred.
In the embodiment of this invention which provides for a liquid detergent containing a builder, a hydrotrope is desirable. Suitable hydrotropes are water-soluble alkali metal salts of toluenesulfonate, benzenesulfonate, and xylenesulfonate. Preferred hydrotropes are potassium or sodium toluenesulfonates. The hydrotrope salt can be added at levels up to about 12%. The hydrotrope functions as a solubilizing agent to produce a product which retains its homogeneity at a low temperature.
The following compositions, in which the percentages are by weight, will serve to illustrate, but not limit, the invention. Each of the compositions in the following examples give in solution a pH within the desired range of from about 8 to about 12.
EXAMPLE A A granular built detergent composition according to this invention has the following formulation:
Percent Sodium alkyl benzene sulfonate in which the alkyl is a straight chain dodecyl radical 18 Sodium oligomeric ester chain condensate of ethane-lhydroxy-l,l-diphosphonic acid having a molecular weight of 1000-3000 50 Sodium sulfate 15 Sodium silicate (ratio of SiO :Na of 2: 1) 7 Water 10 This built detergent composition is especially valuable for laundering heavily soiled clothes.
The straight chain dodecyl benzene sodium sulfonate in the preceding composition can be replaced on an equal Weight basis by either branched chain dodecyl benzene sodium sulfonate, sodium tallow alkyl sulfate, sodium coconut oil alkyl sulfate, sodium olefin sulfonate as de scribed in the specification derived from alpha olefins having an average of 14 carbon atoms in the molecule, or a mixture of straight chain dodecyl benzene sodium sulfonate, and sodium tallow alkyl sulfate on an equal weight basis. Anionic detergents are preferred. The sodium builder salt can be replaced by an ammonium, potassium, or lithium salt; a sodium oligomeric ester chain condensate of ethane-l-hydroxy-l,l-diphosphonic acid having a molecular weight of 800-2500; a 1:1 mixture of sodium triployphosphate and a sodium ester condensate of ethane-l-hydroxy-l,l-diphosphonic acid having a molecular weight of 800-2500; a 1:1:1 ternary mixture of sodium tripolyphosphate, sodium nitrilotriacetate and sodium ester chain condensate of ethane-1-hydroxy-l,1-diphosphonic acid having a molecular weight of 700-2200; potassium ester of chain condensate of ethane-l-hydroxy- 1,1-diphosphonic acid having a molecular weight of 650- 2000; ammonium ester chain condensate of ethane-l-hydroxy-1,l-diphosphonic acid having a molecular weight of 600-1900; or lithium ester chain condensate of ethanel-hydroxy-1,1-diphosphonic acid having a molecular weight of 500-1600.
EXAMPLE B Another effective granular detergent composition has the following formulation:
Percent Straight chain dodecyl benzene sodium sulfonate (anionic detergent) 4 Sodium tallow alkyl sulfate (anionic detergent) 4 Dodecyl methyl sulfoxide 2 Hydrogenated marine oil fatty acid 2 The sodium oligomeric ester chain condensate prepared by Example II above having the general formula given above in which n has a numerical value of 1-16 and a molecular weight of 500-3000 60 Sodium silicate (ratio of SiO :Na O of 1.6:1) 10 Sodium sulfate 14 Water 6 In this example, the total active detergent of 10% can be totally the nonionic species. In addition, the 2% dodecyl methyl sulfoxide can be replaced by the product of a condensation reaction between dodecyl phenol and 5 moles of ethylene oxide per mole of dodecyl phenol, or by 3-(dodecyldimethylamonio)-2-hydroxy propane-1- sulfonate.
The sodium salt of the builder can be added as the salt or it can be present as the free acid neutralized in situ to any salt form ranging from the monosodium or monopotassium salt to the fully neutralized tetrasodium or tetrapotassium salt. The builder can be replaced with a 1:1 equal Weight mixture of potassium-1,2-dicarboxy-2- hydroxy-1,2-diphosphonate and the builder prepared in Example II.
EXAMPLE C Another example of a granular detergent composition of outstanding efficiency:
Percent Straight chain tridecylbenzene sodium sulfonate 1 (anionic detergent) 20 Sodium ester chain condensate of ethane-l-hydroxy- 1,1-diphosphonic acid prepared in Example III having a numerical value for n of 1-16 and a molecular weight of 500-4000 49 Sodium silicate (ratio SiO :Na O of 2: 1) 6 Sodium sulfate 14 Water 11 'lhis detergent compound is also referred to as linear tridecyl benzene sodium sulfonate.
1 EXAMPLE D Toluene sulfonate 1.8 Sodium silicate (ratio of SiO :Na O of 2:1) 8.0 Sodium sulfate 2.0 Diethanolamide of coconut fatty acid 1.9 Benzotriazole .02
Balance to 100% water.
In this composition, the nonionic detergent can be replaced by tetradecyl dimethyl phosphine oxide, sodium-3- dodecylaminopropionate, sodium-3-dodecylaminopropanesulfonate, 3(N,N dimethyl-N-hexadecylammonio)-propane l sulfonate or 3-(N,N dimethyl-N-dodecylammonio)-2hydroxypropane-l-sulfonate. Twenty percent of the builder can be replaced with an equal weight replacement of trisodium ethane-l-hydroxy-1,1-diphosphonate.
As mentioned above, one of the desirable properties of a builder compound is the ability to sequester hardness minerals which may be present in water. The oilgomeric ester chain condensates of the present invention have especially unique sequestering properties. Foremost among these are their sequestering properties both in respect to their efficiency in sequestering and also in respect to how tightly the hardness mineral, e.g., calcium, magnesium, iron and the like is bound by the sequestrant. These notable sequestering properties of the compounds of the present invention are illustrated below by performing a Swatch-Dip test and also be a nephelometric caprate sequestering test.
The Swatch-Dip test demonstrates the relative sequestering ability of a compound in terms of how tightly calcium is bound by the sequestrant. This test involves a procedure employing a fabric-swatch impregnated with soap and an aqueous solution containing a predetermined level of calcium hardness minerals. The procedure involves preparing an aqueous solution containing the hardness ions and dipping or immersing into the solution a fabric-swatch which has been impregnated with a measured amount of soap. The swatch remains in the solution for a predetermined amount of time. A measurement is then made to determine the amount of free calcium which has been adsorbed by the fabric-swatch. The procedure is then repeated but with a predetermined concentration of a sequestrant compound added to the aqueous solution containing the calcium ions. Measurements of calcium adsorbed on the swatch are again made and comparisons drawn. Differences between the amounts of calcium adsorbed in tests with and without sequestrants are attributed to the ability of the sequestrant to sequester the calcium and thereby reduce the amount of free calcium ions available for adsorption by the immersed fabricswatch. A percentage is obtained in this manner which is referred to as percentage hardness retained by sequestrant.
By using this procedure comparisons were made between sodium tripolyphosphate (STP), sodium ethylenediaminetetraacetate (EDTA), and the following compounds which are representative of the compounds to which the present invention pertains:
Oligomer Esters (A) sodium salt of an oligomeric ester chain condensate of ethane-l-hydroxy1,1-diphosphonic acid prepared above in Example 1 as fraction 1; molecular weight of 1000-3000.
Oligomer Ester (B) sodium salt of an oligomeric ester chain condensate of ethane-l-hydroxy-l,l-diphosphonic acid prepared above in Example 1 as fraction 6; molecular weight of 500-1600.
STP is widely recognized as a useful sequestrant compound and builder. EDTA is one of the most eflicient sequestrants known. The demonstration described above revealed surprisingly that the oligomeric ester chain condensates of the present invention are superior to both STP and EDTA in several respects.
In interpreting the results of the Swatch-Dip test, a higher percentage value means that the sequestrant is able to bind calcium ions more tightly than a sequestrant which scores a lower percentage. It was discovered that at an equal concentration of .06% in the solution the oligomeric ester chain condensate (A) above scored a percentage value of about 99%. The oligomeric ester chain condensate (B) above also scored about 99%. EDTA, as expected, received a corresponding high score of about 98-99%. By contrast, STP obtained a percentage value of only about 86%. Both of the representative oligomer ester compounds of the present invention were able to retain their surprisingly high scores even at a concentration range of sequestrant in the test solution of only about 015%. EDTA, however, fell off drastically at a concentration of sequestrant in the test solution below 04%. STP drops off in its sequestering properties rather markedly below a concentration of sequestrant in test solution below .05%.
The useful sequestering properties of the oligomeric ester chain condensates of the present invention are also demonstrable by a nephelornetric caprate sequestering test. The testing procedure employed is that described by Irani and Callis, J. Physical Chemistry, 64, 1398 (1960). The only modification is that caprate was used instead of oxalate as the indicator of the nephelometric endpoint. In this demonstration the same two representative oligomeric ester chain condensates were tested as described in conjunction with the Swatch-Dip demonstration. Comparisons were made with STP. The relative efficiency of each of the sequestrants (in grams of calcium per 100 grams of anhydrous sodium salt were as follows.
The greater efiiciency of the representative compounds of the present invention as sequestering agents over that of ST? is apparent from the results given in the preceding table. It is quite apparent that at pH 8 STP had no measurable sequestering property. By the same token, both of the compounds representative of the present invention were capable of sequestering larger amounts of calcium even at lower pHs of 8-9 than the best score which STP obtained across the full range of pH tested.
The efficiency advantage which the builder compounds of the present invention provide over a standard commercially used builder such as sodium tripolyphosphate is shown by the following demonstration.
A series of detergency tests was conducted which is referred to as a facial swatch test. This test involves a procedure of soiling a cloth swatch with natural soil by attaching a swatch (about 5 inches by 5 inches) to the plunger cup of an electric vibrator massager. Two swatches are soiled from an individual subject by massaging the right and left halves of the face respectively for one minute each. The resulting soiled swatches are randomized into different groups to statistically provide equal numbers of left and right samples. The swatches are then washed, rinsed and graded and the cycle is repeated nine times. The washing step consists of laundering the soiled swatches in an aqueous solution having a temperature of F., a pH of 10, and containing 7 grains hardness.
A mechanical washer is used which is equipped with an agitator and which otherwise simulates an ordinary home washing machine. The detergent compositions tested were comprised of an organic synthetic detergent at a concentration in the wash water of .03% and a builder at a usage concentration of 03%, .04% and, in some cases, .06%. The oligomeric ester chain condensates which were selected as being representative of the present invention for purposes of this demonstration were the following:
Builder No. (l) a sodium oligomeric ester chain condensate prepared as in Example I above and corresponding Fraction No. 1 (average molecular weight 800-2500).
Builder No. (2) a sodium oligomeric ester chain condensate prepared as in Example I above and corresponding to Fraction No. 2 (average molecular weight 800-2500).
Builder No. (3) a sodium oligomeric ester chain condensate prepared as in Example I above and corresponding to Fraction No. 3 (average molecular weight 700-2200).
Builder No. (4) a sodium oligomeric ester chain condensate prepared as in Example I above and correponding to Fraction No. 6 (average molecular weight 500-1600).
Following the washing of the soiled swatches, they were rinsed and dried and then whiteness measurements were made with a commercially available photoelectric reflectometer, i.e., a Hunter Color and Color Difference meter manufactured by Henry A. Gardner Laboratory, Inc. This instrument is designed to distinguish color differences and operates on the tristimulus colorimeter principle. According to this principle, a 45 degree diffuse reflectance of an incident light beam on a test specimen is measured through a combination of green, blue and amber filters. The electrical circuitry of the instrument is so designed that lightness and chromaticity values for the test specimen are read directly. The departure from white (TiO being taken as a standard white) of the test specimen is calculated by introducing the lightness and chromaticity values so obtained into a complex formula supplied by the manufacturer. An evaluation of relative whiteness performance compared to a standard detergent composition is thus obtained for the test formulations. A more comprehensive description of this device and its mode of operation appears in Color in Business, Science and Industry by Deane B. Judd, pages 260-262, published by John Wiley & Sons, New York (1952).
The measurements obtained by the foregoing procedure are given below in the table. The builder efliciency advantage becomes readily apparent from a consideration of these figures.
The synthetic detergent which was used in each of the following evaluations at a concentration in the wash solutions of 03% was sodium dodecylbenzene sulfonate, the dodecyl group being derived from tetrapropylene.
TABLE II .03%, 04%, columnI columln .06%, column Builder compound III In the foregoing table, a statistically significant difference is .68.
It can be seen from Column I headed 03% that the builder compounds of the present invention in each instance surpassed the performance of STP by a significant difference. The builder compound identified under (2) in the table above and which was evaluated at .04% provided a builder performance superior to that of STP at .03% as well as .06%. Moreover, it will be seen that the oligomeric ester chain condensate builder compounds of the present invention all compare favorably with EDTA at 06%.
In addition to the preceding performance evaluations, another demonstration involves measuring cleaning, whiteness and whiteness maintenance properties. For purposes of this invention, these terms have the following meanings. The term cleaning identifies the ability of a built detergent composition to remove soil from soiled fabrics. In part, this applies to the removal of deeply embedded soil deposits such as occurs, for instance, at the collars and cuffs of shirts and blouses. Whiteness is a more general term which identifies or represents a measurement of the ability of a built detergent composition to whiten areas which are only slightly or moderately soiled. Whiteness maintenance is a term which is used to identify the ability of a detergent formulation to prevent the soil which has been removed during a normal washing cycle from being redeposited upon the fabrics during the remainder of the laundering process, e.g., washing and rinsing, etc.
More specifically, the surprising building ability of the oligomeric ester chain condensate builder compounds of the present invention was discovered by Washing naturally soiled white dress shirts with detergent compositions built with dilferent builder materials. Shirts with detachable collars and cuffs were worn by male subjects under ordinary conditions for a certain period of time. The collars and cuffs were then detached and washed in an ordinary agitator type washing machine using solutions of the built detergent compositions being evaluated.
The washed and dried collars and cuffs were graded by means of a visual comparison with other collars and cuffs which had been similarly worn and soiled but which were washed with a standard built detergent composition. The visual comparisons were made by a trained panel of five people who were unfamiliar with any specific details and objectives of the tests. Their judgments were made independently.
Their visual judgments were expressed on a scale ranging from zero to ten. This determination records only the relative cleaning performance grades among the several compositions being evaluated. Zero on the cleaning grade scale represents a cleaning level obtained by washing with water along, i.e., no detergent formulation. A value of ten represents the cleaning level of a specially formulated standardized detergent composition under optimum conditions. For purposes of this evaluation, a value grade of five represents a level of cleaning that is considered satisfactory in household practice. The test described above employed a detergent composition consisting only of an active detergent compound and a builder compound.
For this demonstration the following compounds were selected as being representative of those provided by the present invention: a sodium oligomeric ester described above as No. 1 having a molecular weight 1000-3000; a sodium oligomeric ester described above as No. 2 having a molecular weight 800-2500; and a sodium oligomeric ester described above as No. 4 having a molecular Weight 500-1600.
In this evaluation comparisons were drawn between the builder compounds of the present invention and trisodium methylenedi-phosphonate (MDP), tetrasodium ethylenediaminetetraacetate (EDTA) and pentasodium tripolyphosphate (STP In order to obtain as accurate a measurement as possible of the builder properties of each of the sample compounds, none of the additives usually found in commercial detergent compositions were used in this demonstration. By limiting the compositions to only two ingredients, i.e., a detergent and a builder, there is no interference or masking of the builder function. The concentration of the active detergent in the wash solution was .03% by weight. The concentration of the builders in the wash solution was either .03%, .04% or .06% as indicated in the table below. These percentages correspond to concentrations of .03, .04 and .06 gram per 100 ml. of water. In addition, at washing solutions containing 7 grains per gallon hardness, equivalents (CaCO were adjusted with sodium hydroxide to a pH 10. The temperature of the washing solution was 140 F. The laundering cycle was minutes.
A difference in the cleaning grade scale of one unit represents a significant difference. A housewife readily and consistently can see a cleaning difference between two fabrics which have grades separated by a magnitude of about one unit.
In cleaning performance sodium tripolyphosphate, an excellent builder, when used at a concentration in solution of .06% attains a grade of 5. This same level of cleaning is obtained with only .03% (one-half the concentration) of two of the representative builders of this invention, namely, a sodium oligomeric ester chain condensate of ethane-l-hydroxy-l,l-diphosphonic acid having a molecular weight of 8002500, n=1l6, No. 1 above, and sodium oligomeric ester chain condensate of ethane-l-hydroxy-l,l-diphosphonic acid having a molecular weight of 500-1600, 11:1-16, No. 4 above. In addition, builder No. 1 above, sodium oligomeric ester chain condensate of ethane-l-hydroxy-l,l-diphosphonic acid having a molecular weight of 10003000, at a concentration of only 03%, was graded 7.6 which is far superior to sodium tripolyphosphonate at .03% or .06% concentration.
EDTA, by comparison, at .03% scores only a .4 which is far inferior to the builder compounds described herein. At a concentration of .06%, EDTA did score 7.6 which again was only equal to the compound of the present invention when used at only one-half the concentration, i.e., .03%.
Sodium methylene diphosphonate (MDP) scored only 2.8 at a builder concentration of 06%, again showing the general effectiveness and efficiency of the builder compounds provided by the present invention.
The collar and cuff samples washed in accordance with the preceding discussion were also graded for whiteness performance results.
The whiteness measurements were made on the backs of the cuffs with a commercially available photoelectric reflectometer, i.e., a Hunter Color and Color Difference meter manufactured by Henry A. Gardner Laboratory, Inc. This instrument is designed to distinguish color differences and operates on the tristimulus colorimeter principle. According to this principle, a 45-degree diffuse reflectance of an incident light beam on a test specimen is measured through a combination of green, blue and amber filters. The electrical circuitry of the instrument is so designed that lightness and chromaticity values for the test specimen are read directly. The departure from white (TiO being taken as a standard white) of the test specimen is calculated by introducing the lightness and chromaticity values so obtained into a complex formula supplied by the manufacturer. An evaluation of relative whiteness performance compared to a standard detergent composition is thus obtained for the test formulations and interpolated into a 1l0 scale. A more comprehensive description of this device and its mode of operation appears in Color In Business, Science and Industry by Deane B. Judd, pp. 260262; published by John Wiley & Sons, New York (1952).
In this demonstration also the oligomeric ester chain condensate builder compounds of the present invention were shown to be generally more effective and efficient than the other builders tested and mentioned above.
The evaluation of whiteness maintenance capability of the respective builders was performed by the following method. Unsoiled swatches of cotton terry cloth were washed with the wash solutions obtained from the cleaning tests. In other words, the unsoiled swatches are added to the dirty wash water from the cleaning tests. The swatches are dried and then the whitness thereof is measured by a Hunter Color and Color Difference Meter following the same procedure described above. The soil adhering to the swatches is a relative measure of soil which has been adsorbed from the washing solutions containing the aforementioned representative builders. Factors are involved here other than the anti-redeposition characteristics of the built detergent composition. It is, however, one way of demonstrating this property; and for showing relative performance, the test is valuable.
As with the cleaning and whiteness evaluation, the oligomeric ester chain condensates of this invention were shown to be highly effective and performed on a parity with sodium tripolyphosphate.
The foregoing description of the present invention has been presented describing certain operable and preferred embodiments. It is not intended that the invention should be so limited since variations and modifications thereof will be obvious to those skilled in the art, all of which are within the spirit and scope of this invention.
What is claimed is:
1. A detergent composition consisting essentially of:
(a) an organic synthetic detergent selected from the group consisting of water soluble anionic nonionic, ampholytic and zwitterionic detergents and mixtures thereof, and
(b) an oligomeric ester chain condensate of ethanel-hydroxy-l,l-diphosphonic acid having the formula wherein each M is selected from hydrogen, alkali metal, ammonium, alkylammonium, hydroxyalkylammonium, the alkyl and hydroxyalkyl groups each having 1 to about 4 carbons; R is hydrogen or acetyl; and n has a numerical value in the range of 1 to about 16, the molecular weight of the condensates being in the range of about 500 to about 4000; the proportion of said detergent to said oligomeric ester being in the range of from about 5:1 to about 1:20, by weight.
2. A built detergent composition of claim 1 in which the proportion of said detergent to said oligomeric ester is in the range of from about 2:1 to about 1:10.
6. A detergent composition of claim 1 in which said oligomeric ester is an alkali metal salt.
4. A detergent composition of claim 1 in which the numerical value for n is from 2 to about 12 and the molecular weight is from 700 to about 3000.
5. A detergent composition of claim 1 in which the detergent is an anionic detergent.
References Cited UNITED STATES PATENTS 3,400,148 9/1968 Quimby .252-152X LEON D. ROSDOL, Primary Examiner M. HALPE-RN, Assistant Examiner US. Cl. X.R.