GB2076011A - Coated white diphenyl and stilbene fabric brighteners - Google Patents

Abstract

Detergent additive compositions are disclosed comprising diphenyl and stilbene fabric brighteners that are normally coloured but which are rendered substantially white by mixture with hydroxyl- containing compounds and coating of the mixture with a normally solid water-soluble organic coating material.

Description

SPECIFICATION Coated white diphenyl and stilbene fabric brighteners TECHNICAL FIELD The present invention is related to the optical whitening of fabrics. In particular it provides for the addition of fabric brightening agents to white granular detergent compositions such that the fabric brightening agent do not discolor the granular compositions.

BACKGROUND The inclusion of fabric brightening agents in granular washing compositions for the optical whitening of fabrics is w911 known in the art. It is also well known in the art that as the level of fabric brightening agents in granular compositions is increased, said agents may impart a yellowish or green yhue to white compositions which give consumers a negative impression about the granular composition.

The manufacturers of fabric whitening agents have sought to minimize the discoloration effect by modification of said agents. For example, U.S. Patent 3,951,960 issued April 20, 1976 to Heath et al.

and assigned to Sterling Drug inc. teaches that the problem of granule discoloration in the use of certain disodium stilbene fabric whitening agents can be minimized by producing said agents in the form of white to light cream colored needle-shaped crystals rather than in the amorphous form or in other crystalline forms. Simiiarly, U.S. Patent 3,994,834 issued November 30, 1976 to Dorlars et al and assigned to Bayer teaches that the white granule discoloration caused by certain stilbene fabric whitening agents can be avoided by producing the dispotassium salt thereof in certain preferred crystal forms.

Detergent composition makers have sought ways of avoiding product yellowing due to fabric brighteners by the inclusion of additives to the composition. Mitsui Toatsu's Japanese Publn. 6687/76, dated March 1, 1 976 discloses that product yellowing due to certain stilbene type fabric brighteners can be avoided by the inclusion of from 1 to 10% of a nonionic surface active agent in the detergent composition. Nippon's Japanese Publication 74000967, dated January 10, 1 974 discloses that product yellowing due to the presence of more than 0.5 parts of certain stilbene type fabric brishteners can be avoided by the inclusion of 0.5-5 parts of one or a mixture of nonionic surfactants.Kao's Japanese Publication 5308/76, dated January 17, 1976 discloses the inclusion of from 0.1-5.0 parts of polyhydric alcohol or saccharide having at least 3 hydroxy radicals in a detergent composition to avoid product yellowing due to 0.25 parts or more of certain stilbene or diphenyl type fabric brighteners.

With regard to the instant invention, it should be mentioned that the simple coating of fabric brighteners is known in the art. U.S. Patent 3,846,324, issued November 5, 1974 to Lohmann et al. and assigned to Ciba-Geigy AG, discloses encasing brighteners in a water-soluble coating agent to improve brightener stability in a detergent composition which contains a chlorine donor which releases hypochlorite ion. B.P. 1,242,689 published August 11, 1 971 and granted to Ciba-Geigy A.G. discloses that slightly water-soluble fabric brighteners can be prevented from aggregating in a detergent composition by coating the fabric brightener with an organic water-soluble protective substance.

The inclusion of fabric brightening agents in detergent compositions provides a real benefit.

Unfortunately, fabric brighteners do tend to have a yellow or yellow-green color which can cause yellowing of a white granular composition. The addition of ingredients in the composition as suggested in the references cited hereinabove may minimize the yellowing of white granular compositions as made but in time (i.e. during storage) the yellowing color reappears.

It is an object of this invention to provide compositions containing fabric brighteners which result in better appearing white granular laundry compositions as made and which do not yellow on standing after extended periods of time.

SUMMARY OF THE INVENTION The present invention is based in part upon the discovery the diphenyl and stilbene brighteners, which normally have a yellow-green or yellowish hue, will combine with a hydroxyl-containing compound and be rendered substantially white. Coating of the white brightener-hydroxyl compound combination protects the combination against loss of the hydroxy-containing compound during storage.

In the detergent additive aspect of the invention there is provided a substantially white detergent additive comprising: ;(a) from 0.1% to 15% of a fabric brightener selected from the group consisting of

wherein X, and X2 represent the radical SO3M or a halogen atom, R1-R4 can be the same or different and represent a C1-C4 alkoxy, alkanolamine, alkylamino, morpholino or aromatic amino group, and M represents a hydrogen atom, alkali metal or ammonium group; (b) from 0.1% to 45% of a hydroxyl-containing compound that combines with the fabric brightener to render it substantially white; and (c) from 40% to 99.8% of a normally solid, water-soluble organic coating material.

In the detergent composition aspect of the invention, there is provided a granular detergent comprising 0.5 to 1 5 parts by weight of a detergent additive defined hereinabove and 85 to 99.5 parts by weight of detergent granules comprising 2% to 35% by weight of a surface-active agent selected from the group consisting of anionic, nonionic, ampholytic, and zwitterionic surface-active materials, and 10% to 65% by weight of a detergent builder salt.

DETAILED DESCRIPTION OF THE INVENTION The detergent additive of this invention comprises relatively water-soluble fabric brighteners of the stilbene or diphenyl type, a hydroxyl-containing compound capable of combining with the brightener to render it substantially white and a normally solid water-soluble organic coating material.

The Fabric Brightener The fabric brightener can be present in the detergent additive in an amount from 0.1% to 1 5%, preferably from 0.3% to 10%, and most preferably from 0.5% to 5%, by weight, of the detergent additive.

The brighteners are selected from the group consisting of:

wherein X,, X2, R1-R4, and M are as defined hereinabove.

A commercially available fabric brightener of the diphenyl type is disodium 4,4'- bis (2-sulfostyryl) diphenyl. It has a solubility in water of 2.5% in water at 250C and a solubility of 30% at 950C. As purchesed it is a yellowish-green powder which is 95% brightener and 5% sodium chloride.

A commercially available stilbene type brightener is one where R1 and R3 are both aniline groups and R2 and R4 are both morpholine groups. It has the name disodium 4,4' bis [(6-anilino-4-morpholino 1,3,5-triazin-2-yl) amino] stilbene-2,2'-disulfonate. It has a 250C water solubility of 0.7% and a 950C water solubility of 5%. As purchased it is a yellowish powder which is 90% brightener and 10% sodium sulfate.

The Hydroxyl-Containing Compound It was surprisingly discovered that the diphenyi and stilbene brighteners combine with hydroxylcontaining compounds to render the brighteners substantially white. The reason for this color change is not understood but is believed to be some kind of a solvent effect which results in a chromatic shift.

The suitable hydroxy-containing compounds include any of the said compounds which when combined with the brighteners herein render the brighteners substantially white.

Specific examples of suitable hydroxyl-containing compounds include water, C1-C6 alcohols, diols (e.g. 1,2-pentanediol), polyhydric alcohols (e.g. 1.2,6-hexanetriol, glycerine) saccharides(e.g.

fructose, lactose), alcohol ethoxylates having from 3 to 8 carbon atoms in the alkyl chain and an average of from 2 to 12 moles of ethylene oxide per mole of alcohol, C3-C8 alkylphenols having an average of from 2 to 12 moles of ethylene oxide per mole of alcohol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, polyethylene and polypropylene glycols having a molecular weight in the range of from about 200 to 3500. Preferred compounds, for ease of handling, availability, and nonvolatility are the polyethylene glycols having a molecular weight in the range of from 300 to about 1500.

The amount of hydroxyl-containing compounds in the detergent additive can be from 0.1% to 45%, preferably 0.3% to 30%, and most preferably from 1% to 1 5%, by weight of the detergent additive.

The Coating Material The third essential ingredient of the detergent additive is the normally solid, water-soluble organic material that is used to coat the brightener/hydroxyl-containing compound mixture. The term "normally solid" means solid at normal ambient temperatures, i.e., below 320C. A wide variety of materials fitting the above criteria and compatible with the fabric brighteners of this invention are useful in the context of the present invention. With regard to water solubility, the coating material should release the fabric brightener within at most 5 minutes and preferably within 2 minutes after the detergent additive is put into an aqueous medium.The preferred coating materials are those that can be melted or softened sufficiently to become fluid between a temperature of 38"C to 93"C, more preferably between 43"C and 79"C, and most preferably between 49"C and 660 C.

Specific examples of solid organic protective materials suitable for use in this invention are: (1) The condensation products of one mole of a saturated or unsaturated, straight or branched chain carboxylic acid having from 10 to 1 8 carbon atoms with from 20 to 50 moles of ethylene oxide, which liquefy between the temperatures of 430C and 930C and are solid at temperatures below 380C.

The acid moiety can consist of mixtures of acids in the above delineated carbon atom range or it can consist of an acid having a specific number of carbon atoms within this range. The condensation product of one mole of coconut fatty acid having the approximate carbon chain length distribution of 2% C10,66% C12,23% C14, and 9% C16 with 35 moles of ethylene oxide is a specific example of a nonionic' containing a mixture of different chain length fatty acid moieties.Other specific examples of nonionics of this type are: the condensation products of one mole of palmitic acid with 40 moles of ethylene oxide; the condensation product of one mole of myristic acid with 35 moles of ethylene oxide; the condensation product of one mole of oieic acid with 45 moles of ethylene oxide; and the condensation product of one mole of stearic acid with 30 moles of ethylene oxide.

(2) The condensation products of one mole of a saturated or unsaturated, straight or branched chain alcohol having from 10 to 24 carbon atoms with from 9 to 50 moles of ethylene oxide, which liquefy between the temperatures of 430C and 930C and are solid at temperatures below 43 OC. The alcohol moiety can consist of mixtures of alcohols in the above-delineated carbon atom range or it can consist of an alcohol having a specific number of carbon atoms within this range. The condensation product of one mole of coconut alcohol having the approximate chain length distribution of 2% C10, 66% C12,23% C14, and 9% C16 with 45 moles of ethylene oxide (CNAE45) is a specific and highly preferred example of a nonionic containing a mixture of different chain length alcohol moieties.Other specific examples of nonionics of this type are the condensation products of one mole of tallow alcohol with 20 moles of ethylene oxide; the condensation products of one or more of lauryl alcohol with 35 moles of ethylene oxide; the condensation, products of one mole of myristyl alcohol with 30 moles of ethylene oxide; and the condensation products of one mole of oleyl alcohol with 40 moles of ethylene oxide.

(3) Two specific examples of nonionic surface active agents suitable for use in this invention and not specifically classified herein are polyoxyethylene glyceride esters having a hydrophilic-lipophilic balance (HLB) of 18.1 and polyoxyethylene lanolin derivatives having an HLB of 17:0. Both nonionics are manufactured by Atlas Chemical Industries, Inc.; the trade name of the former is G-1 300 and the trade name of the latter is G-1 795.

(4) Amides which have a melting point between 380C and 930C are also suitable for use in this invention. Specific examples are propyl amide, N-methyl amides having an acyl chain length of from 1 0 to 15 carbon atoms, pentyl analide and anilides having a carbon chain length of from 7 to 12 carbon atoms, oleamide, amides of racinoleic acid, N-isobutyl amides of pelargonic acid, capric acid, undecanoic acid and it uric acid, N-(2-hydroxyethyl) amides having a carbon chain length of from 6 to 10 carbon atoms, N-cyclopentyllauramide and N-cyclopentylstearamide.

(5) The polyethylene glycols and polypropylene glycols having a molecular weight of from 3500 to 30,000. For example, Dow Chemical Company manufactures these nonionics in molecular weights of 20,000, 9500, 7400, 4500, and 3400. All of these nonionics are waxlike, solids which melt between 380C to 930C.

(6) The condensation products of one mole of alkyl phenol wherein the alkyl chain contains from 8 to 1 8 carbon atoms with from 25 to 50 moles of ethylene oxide. Specific examples of these nonionics are the condensation products of one mole of decyl phenol with 40 moles of ethylene oxide; the condensation products of one mole of dodecyl phenol with 35 moles of ethylene oxide; the condensation products of one mole of tetradecyl phenol with 35 moles of ethylene oxide; the condensation products of one mole of hexadecyl phenol with 30 moles of ethylene oxide.

(7) The alkali metal salts of fatty acids containing from 12 to 30 carbon atoms, preferably from 12 to 1 8 carbon atoms. Specific examples include the sodium salts of lauric acid, myristic acid, plamitic acid, stearic acid, tallow acid or mixtures of tallow acid and coconut acid, arachidic acid, behenic acid and lignoceric acid.

(8) The condensation products of ethylene oxide with a hydrophobic base formed by the condensation product of propylene oxide with propylene glycol. the hydrophobic portion of these compounds has a molecular weight of from 950 to 4000 and of course exhibits water insolubility. The addition of polyoxyethylene moieties to this hydrophibic 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 the polyethylene content is 50% of the total weight of the condensation product. Examples of compounds of this type include certain of the commercially available PluronicB surfactants which are defined in the booklet "The Wonderful World of Pluronic Polyols,B 1971 BASF Wyandote Corporation.

Normaliy solid, water-soluble organic materials other that those listed above can also be used as protective agents in this invention provided they are compatible with the fabric brightener. Preferred organic materials having a low hygroscopicity; for example, polyethylene glycols of molecular weight 4000 to 6000 are reported in Kirk OthmerEncyclopedia of Chemical Technology, 2nd edition, volume 10, page 652, as having a comparative hygroscopicity of 1, relative to 100 for glycerol. This is conveniently measured by means of a hair hygrometer as disclosed in Ibid, volume 2, pages 692 and 693.

Other suitable film forming substances having the required water solubility and compatability have been described by R. L. Davidson and Marshall Siftig in "Water Soluble Resins," Reinhold Publ. Corp., New York, 1962. Coating materials of special value which may be mentioned because they are cheap and readily available commercially are the polyvinylpyrrolidones, polymers of acrylic or methacrylic acid and their ester- and amide-derivatives, styrene-maleic acid copolymers, polyvinyl alcohols, cellulose ethers, water-soluble starches, water-soluble condensates of formaldehyde with urea or melamine, cellulose -sulphuric acid ester, carboxyalkylcelluloses, alginic acid and its salts, and condensates of P- naphthalenesulphonic acid and formaldehyde.

The coated detergent additives of this invention are produced by a process comprising the steps of (a) combining the fabric brightener with the hydroxyl-containing compound to render the fabric brightener substantially white and then (b) adding the mixture to the coating material which has been heated sufficiently to be in a molten state. After thorough mixing the molten mass is then passed over a chill roll to solidify the mass which can then be ground to size. A preferred size is that which approximates the particle size distribution of the detergent granules to which the additive will be added to make the finished detergent composition.

The coated detergent additive can be dry-added to detergent granules as mentioned above or alternatively the molten mass from step (b) can be sprayed directly onto detergent granules in a rotating drum, pan agglomerator, fluidized bed or the like.

In light of the teaching herein it will be appreciated that alternative methods of having decolorized diphenyl- and stilbene-type brighteners in solid detergent compositions are possible. One method is to combine the brighteners with the hydroxyl-containing compound, especially PEG having a molecular weight in the range of from 300 to 1500, to make the brightener colorless and then adding this mixture to a slurry of the detergent composition containing the other ingredients and then drying to form the solid detergent composition.

With regard to the diphenyl-type brighteners, as discovered by this invention, yet another alternative procedure is to add the hydroxyl-containing compound, especially PEG having a molecular weight in the range of 300 to 1 500, directly to a slurry of the detergent composition containing the diphenyl brightener and drying to form the solid detergent composition.

Surfactant In the detergent composition aspect of the invention the coated detergent additive can be incorporated into conventional granular detergent formulations together with a wide range of surfactants and detergent builder salts. The level of additive in the product is normally in the range of 1% to 1 5% by weight of the total composition, preferably from 2% to 5%, and is adjusted to deliver the desired amount of fabric brightener to the product.

From 1% to 50% by weight, preferably 5% to 25% by weight, and most preferably from 10% to 20% by weight of the detergent compositions can comprise an organic surfactant selected from the group consisting of anionic, nonionic, ampholytic, and zwitterionic detergents and mixtures thereof.

Examples of organic surfactants of these types are described in U.S. Patent 3,579,454; column 11, line 45 to column 13, line 64.

Water-soluble salts of the higher fatty acids, i.e., "soaps" are useful as the anionic surfactant herein. This class of surfactants includes ordinary alkali metal soaps such as the sodium, potassium, ammonium, and alkanolammonium slats of higher fatty acids containing from 8 to 24 carbon atoms and preferably from 10 to 20 carbon atoms. Soaps can be made by direct saponification of fats and oils or by the neutralization of free fatty acids. 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 soaps.

Another class of anionic surfactants includes water-soluble salts, particularly the alkali metal, ammonium and alkanolammonium salts or organic sulfuric reaction products having in their molecular structure an alkyl group containing from 8 to 22 carbon atoms and a sulfonic acid or sulfuric acid ester group. (Included in the term "alkyl" is the alkyl portion of acyl groups.) Examples of this group of synthetic surfactants which can be used in the present invention are the sodium and potassium alkyl 'sulfates, especially those obtained by sulfating the higher alcohols (C8-C18 carbon atoms) produced by reducing the glycerides of tallow or coconut oil; and sodium and potassium alkyl benzene sulfonates, in which the alkyl group contains from about 9 to about 1 5 carbon atoms in straight chain or branched chain configuration, e.g., those of the type described in U.S. Patents 2,200,099 and 2,477,383, (especially valuable are linear straight chain alkyl benzene sulfonates in which the average of the alkyl groups is 11.8 carbon atoms and commonly abbreviated as C116 LAS).

Other preferred detergents for use herein are alkyl ether sulfates. These materials have the formula RO (C2H40)xSO3M wherein R is alkyl or alkenyl of 10 to 20 carbon atoms, x is 1 to 30, and M is a water soluble cation such as alkali metal, ammonium, and substituted ammonium. The alkyl ether sulfates useful in the present invention are condensation products of ethylene oxide and monohydric alcohols having 10 to 20 carbon atoms. Preferably, R has 14 to 1 8 carbon atoms. The alcohols can be derived from fats, e.g., coconut oil or tallow, or can be synthetic. Lauryl alcohol and straight chain alcohols derived from tallow are preferred herein.Such alcohols are reacted with 1 to 30, and especially 1 to 6, molar proportions of ethylene oxide and the resulting mixture of molecular species, having, for example, an average of 3 moles of ethylene oxide per mole of alcohol, is sulfated and neutralized.

Specific examples of fat-derived alkyl ether sulfates of the present invention are sodium coconut alkyl ethylene glycol ether sulfate; sodium tallow alkyl trioxyethylene ether sulfate; and sodium tallow alkyl hexaoxyethylene sulfate.

Examples of alkyl ether sulfates of synthetic origin in which the starting alcohol is a narrow-cut olefin feed stock include sodium C,4~15 alkyl trioxyethylene ether sulfate and C,5~,6 alkyl trioxyethylene ether sulfate.

Other anionic surfactant compounds herein include the 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; and sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate containing 1 to 10 units of ethylene oxide per molecule and wherein the alkyl groups contain from 8 to 12 carbon atoms.

Other useful anionic surfactants herein include the water-soluble salts of esters of a-sulfonated fatty acids containing from 6 to 20 carbon atoms in the ester group; water-soluble salts of 2-acyloxyalkane-1-sulfonic acids containing from 2 to 9 carbon atoms in the acyl group and from 9 to 23 carbon atoms in the alkane moiety; alkene sulfonates containing from 10 to 20 carbon atoms in the alkane group; and ,B-alkyloxy alkane sulfonates containing from 1 to 3 carbon atoms in the alkyl group and from 8 to 20 carbon atoms in the alkane moiety.

Other preferred detergents utilizable herein are olefin sulfonates having about 12 to about 24 carbon atoms. The term "olefin sulfonates" is used herein to mean compounds which can be produced by the sulfonation of ct-olefins by means of uncomplexed sulfur trioxide, followed by neutralization of the acid reaction mixture in conditions such that any sultones which have been formed in the reaction are hydrolyzed to give the corresponding hydroxy-alkane sulfonates. The sulfur trioxide can be liquid or gaseous, and is usually, but not necessarily, diluted by inert diluents, for example by liquid SO2, chlorinated hydrocarbons, etc., when used in the liquid form, or by air, nitrogen, gaseous SO2, etc., when used in the gaseous form.

The n-olefins from which the olefin sulfonates are derived are mono-olefins having 1 2 to 24 carbon atoms, preferably 1 4 to 1 6 carbon atoms. Preferably they are straight chain olefins. Examples of suitable 1-olefins include 1 -dodecane, 1 -tetradecene, 1 -hexadecene, 1 -octadecene, 1 -eicosene, and j-tetracosene.

In addition to the true alkene sulfonates and a portion of hydroxy-alkane sulfonates, the olefin sulfonates can contain minor amounts of other materials, such as alkene disulfonates depending upon the reaction conditions proportion of reactants, the nature of the starting olefins and impurities in the olefin stock and side reactions during the sulfonation process.

A specific anionic detergent which is useful in the present invention is described more fully in the U.S. Patent 3,332,880 of Phillip F. Pflaumer and Adrian Kessler, issued July 25, 1 967, titled "Detergent Composition".

Preferred nonionic surfactants useful in the present invention are those obtained by the condensation of one to twelve ethylene oxide moieties with a C10-C18 aliphatic alcohol. The alcohol may be completely linear as occurs in materials derived from natural feedstocks such as vegetable oils and animal fats, or may be slightly branched as occurs in petroleum-derived alcohols made by oxo-type synthesis. Particularly preferred materials are C14-C15 alcohol condensed with an average of seven ethylene oxide groups, C12-C13 alcohol condensed with an average of about four ethylene oxide groups and then subjected to stripping to remove unethoxylated and low ethoxylated materials, to leave an ethoxylate having a mean of 4.5 ethylene oxide groups.

Preferred zwitterionic materials are derivatives of quaternary ammonium compounds containing an aliphatic straight chain group of 14 18 carbon atoms and a sulfate or sulfonate anionic solubilizing group. Specific examples include 3-(N,N-dimethyl-N-hexadecyl ammonio-2-hydroxypropane-1 - sulfonate; 3-(N,N-dimethyl-N-tallowyl am monio)-2-hydroxypropane- 1 -su Ifonate; 3-(N,N-dimethyl-Ntetradecyl ammonio)propane-1 -sulfonate; and 6-(N,N-dimethyl-N-hexadecylammonio)hexanoate.

Detergency Builders Detergent compositions comprising the coated detergent additive of the instant invention normally contain a detergent builder in an amount from 5% to 95% by weight, preferably from 1 5% to 60% by weight of the composition. Useful builders therein include any of the conventional inorganic and organic water-soluble builder salts as well as various water-insoluble and so-called "seeded" builders.

In these compositions these water-soluble builder salts serve to maintain the pH of the laundry solution in the range of from 7 to 12, preferably from 8 to 11.

Furthermore, these builder salts enhance the fabric cleaning performance of the overall compositions while at the same time they serve to suspend particulate soil release from the surface of the fabrics and prevent its redeposition on the fabric surfaces.

Suitable detergent builder salts useful herein can be of the polyvalent inorganic and polyvalent organic types, or mixtures thereof. Non-limiting examples of suitable water-soluble, inorganic alkaline detergent builder salts include the alkali metal carbonates, borates, phosphates, polyphosphates, tripolyphosphates, bicarbonates, silicates, and sulfates. Specific examples of such salts include the sodium and potassium tetraborates, bicarbonates, carbonates, tripolyphosphates, pyrophosphates, and orthophosphates. Of course, mixtures are also useful.

Examples of suitable organic alkaline detergency builder salts are: (1) water-soluble amino polyacetates, e.g., sodium and potassoium ethylenediamine-tetraacetates, nitrilotriacetates, and N-(2hydroxyethyl)nitrilodiacetates; (2) water-soluble salts of phytic acid, e.g., sodium and potassium phytates; (3) water-soluble polyphosphonates, including, sodium, potassium and lithium salts of ethane-1-hydroxy-1, 1-diphosphonic acid; sodium, potassium, and lithium salts of methylenediphosphonic acid and the like.

Additional organic builder salts useful herein include the polycarboxylate materials described in U.S. Patent 2,264,103, including the water-soluble alkali metal salts of mellitic acid. The water-soluble salts of polycarboxylate polymers and copolymers such as are described in U.S. Patent 3,308,067 are also suitable herein. It is to be understood that while the alkali metal salts of the foregoing inorganic and organic polyvalent anionic builder salts are preferred for use herein from an economic standpoint, the ammonium, alkanolammonium, e.g., triethanolammonium, diethanolammonium, and the like, watersoluble salts of any of the foregoing builder anions are useful herein.

Mixtures of organic and/or inorganic builders can be used herein. One such mixture of builders is disclosed in Canadian Patent 755,038, e.g., a ternary mixture of sodium tripolyphosphate, trisodium nitrilotriacetate, and trisodium ethane-1 -hydroxy-1 , 1 -diphosphonate.

Another type of builder useful herein includes various substantially water-insoluble materials which are capable of reducing the hardness content of laundering liquors, e.g., by ion-exchange processes. Examples of such builder materials include the phosphorylated cloths disclosed in U.S.

Patent 3,424,545 to Bauman issued January 28, 1969.

A further class of insoluble builder salts is the alumino silicate type which functions by cation exchange to remove polyvalent mineral hardness and heavy metal ions from solution. A preferred builder of this type has the formulation Naz (AlOz)z (SiO2)v x H20 wherein z andy are integers of at least 6, the molar ration of z toy is in the range of from 1.0 to 0.5 and xis an integer from 15 to 264 said aluminosilicate having a calcium ion exchange capacity of at least 200 mg eq/g; a calcium ion exchange rate of at least 2 grains/minute/gram; and a particle size of from 0.1--1 0 u. Compositions incorporating builder salts of this type are the subject of U.S. Patent 3,985,669 issued to Krummel et al.

on October 12, 1976 and U.S Patent 4,000,094 issued to Fleming et al. on December 28, 1 976.

Another type of detergency material useful in these compositions and processes comprises a water-soluble material capable of forming a water-insoluble reaction product with water hardness cations in combination with a crystallization seed which is capable of providing growth sites for said reaction product. "Seeded builder" compositions of this type are described in Belgian Patent No.

798,856 published on October 1973.

More particularly, the seeded builders useful herein comprise a crystallization seed having a maximum particle dimension of less than 20 microns preferably a particle diameter of from 0.01 microns to 1 micron, in combination with a material capable of forming a water-insolubie reaction product with free metal ions.

A seeded builder comprising a mixture of sodium carbonate and calcium carbonate is especially preferred herein. A highly preferred seeded builder comprises a 30:1 tp 5:1 (wt. Na2CO3:CaCO3) mixture of sodium carbonate and calcium carbonate wherein the calcium carbonate has an average particle diameter from 0.01 micron to 5 microns.

Optional ingredients that may also be incorporated in detergent compositions of the present invention include enzymes for removal of protein-based or carbohydrate-based stains. Enzymes for removing protein-based stains are proteolytic in nature such as those sold under the trade names "Alcalase" and "Esterase" by Novo Industries A/S Denmark or under the trade names "Maxatase" and "AZ Protease" by Gist-Brocades N.V. The Netherlands. These materials are normally incorporated at levels of up to 1% by weight, preferably 0.25% to 0.75% by weight, and are preferably coated or prilled with inert additives to minimize dust formation and improve storage stability. A wide range of enzyme materials and means for their incorporation into synthetic detergent granules is disclosed in U.S.Patent 3,553,139 issued on January 5, 1 971, to McCarty, Roald, DeOude, Blomeyer, and Cracco.

A further ingredient that may be incorporated to improve product performance is a bleaching agent of the halogen or oxygen-containing type or the porphine type. Examples of the hypohalite bleach type include trichloro isocyanuric acid and the sodium and potassium dichloroisocyanurates and Nchloro and N-bromo alkane sulphonamides. Such materials are normally added at 0.5%-1 0% by weight of the finished product, preferably 1 %5% by weight.

The porphine type include zinc or aluminum phthalocyanine sulfonate. They are incorporated in detergent compositions t levels of from 0.003% to 1.5%. This type of bleach works by photoactivation but it also works in the c ark in the presence of oxygen-containing bleach.

Examples of oxygen-containing bleaches include sodium perborate, sodium percarbonate, and potassium nonopersulphate that are incorporated at levels of 530%, preferably 1 0-25% by weight of the final product. The inclusion of organic bleach activators such as phthalic anhydride, tetra acetyl ethylene diamine, tetra acetyl methylene diamine or tetra acetyl glycouril lead to the in situ production during the washing process of the corresponding organic peroxy acids which have enhanced low temperature bleaching performance. Activators of this type are normally used with sodium perborate, at usage levels of 5-1 5% by weight of the final product.

Materials to boost or modify the sudsing pattern of the composition of the present invention may also be included. Examples of suds boosters include coconut and tallow mono- and di-alkanolamides, particularly ethanolamides and C1216 alkyl di-lower alkyl amine oxides. Typical sudsing depressors include long chain fatty acids such as those disclosed in U.S. Patent 2,954,347 issued September 27, 1960, to Wayne St. John and combinations of certain nonionics therewith as disclosed in U.S. Patent 2,954,343 issued September 27, 1960, to Eugene Schwoeppe.

Other optional ingredients in grannular products include hydrotropes and anticaking additives such as salts of lower alkyl-aryl sulphonic acids, salts of a-sulphosuccinic acid, and a-sulphobenzoic acid, and urea, normally utilized at levels of 0.5% to 5% by weight of the final product, preferably at levels of 1 %3% by weight. C12- C18 alkyl acid phosphates and their condensation products with ethylene oxide may also be incorporated at similar levels of control of crutcher mix viscosity. Antiredeposition agents such as carboxymethyl cellulose, hydroxyethyl cellulose, and their derivatives may also be incorporated.

Advantageously, ingredients may also be included to minimize the wrinkling of fabrics that occurs during conventional drying processes. Detergent products incorporating starch and other particulate materials useful as fabric conditioning agents are disclosed in Belgian Patent No.811,082, published August 1 6, 1 974. A non-limiting example of such a fabric conditioning agent is corn starch, which can be added at a level of 0.15.0% by weight of the composition, preferably 0.251.0%.

Anti-tarnish and anti-corrosion agents, perfume and colour may also be included, the last ingredient being conventionally added either as a general colour or in the form of a speckle applied to a separate granule fraction of the entire formulation or to a granulate of one or more of the ingredients.

The pH of detergent formulations in accordance with the present invention can lie anywhere within the range 5-12 but is preferably chosen to fall within the range 8.0-10.5 as this provides a slight particulate soil removal benefit on synthetic fabrics. However, the use of specific optional components such as enzymes may require the selection of a product pH that will permit optimum functioning of the component concerned.

The following examples iliustrate the production, according to this invention, of coated brightener additives and their inclusion in detergent compositions.

EXAMPLE I Following the observation that hydroxyl-containing compounds render the diphenyl and stilbene fabric brighteners substantially white a screening test was devised to rapidly determine which hydroxylcontaining compounds are suitable for this invention. To about 25 ml. of the hydroxyl-containing compound was added 1-2 grams of brightener and the color of the mixture was observed.

Representative results were as follows: Compound Brightener Result Glycerine 1 turns white PEG 400 1,2 Ethylene glycol 1,2 PEG 3500 1 slightly greenish hue Diethylene glycol 1 turns white Propylene glycol 1 Ethanol 1 1 ,2-pentanediol 1 1 ,2,6-hexantriol 1 PEG 1500 1 Dobanol 918* 1 C12E3** 1 Softanol 70 *** 1 PEG 6000 1 no change Lauryl alcohol 1 Water 1 Brightener 1 is disodium 4,41 (2-sulfostyryl) diphenyl.

Brightener 2 is the aniline and morpholine substituted stilbene compound mentioned at page 7 lines 9-10.

* Dobanol 91-8 is an ethoxylated primary alcohol having 9-11 1 carbon atoms and an average of 8 moles of ethylene oxide per mole of alcohol.

** C,2E3 is lauryl alcohol ethoxylated with 3 moles of ethylene oxide per mole of alcohol.

i++ Softanol 70 is a secondary alcohol having about 12 carbon atoms and ethoxylated with 7 moles of ethylene oxide per mole of alcohol.

The surprising result with water was further investigated. It was found that if the fabric brightener was first dispersed in a little molten PEG 6000 and then water was added, the mass wouid turn white.

The mass could then be mixed with additional molten PEG 6000 to make the detergent additive.

EXAMPLE II TO 90 grams of PEG 400 was added 37 grams of the sodium salt of brightener "1 " in Example The mixture changed from a yellow-green color to a substantially white mixture in about 90 minutes.

The mixture was then added to 873 grams of molten PEG 6000 (1650--1850F). Following thorough mixing the molten mass was put through a chill roll to cool and solidify the mass in the form of flakes.

The flakes were then ground to a particle size in the range of from 20 to 60 mesh (Tyler).

The whiteness of the coated detergent additive prepared above can be further enhanced by the addition of a tinting agent such as TiO2 or white compatible compounds such as sodium carbonate, glassy phosphate (e.g. Na23P2,064), etc. in the molten mass just prior to cooling, solidifying and flaking the mass.

EXAMPLE Ill A detergent composition was prepared according to the invention and compared in its ability to brighten cotton fabric against a similar composition wherein all the fabric brightener was added to the slurry containing the detergent components and spray-dried. The compositions and results follow.

Composition Control A Linear C,2 alkylbenzene sulfonate, Na salt 18.0 18.0 Na4P207 13.31 13.31 Hardened tallow fatty acid 2.25 2.25 Silicate solids 12.0 12.0 Aluminosilicate builder 8.0 8.0 Disodium 4,4'-(2-sulfostyryl) diphenyl 0.12 0.09 Na2CO3 15.0 15.0 Na2SO4 23.04 22.87 Moisture 6.5 6.5 PEG 6000/Glass H 1.7 Detergent additive flakes 1.9 Miscellaneous to 100 to 100 The detergent additive flake composition was 0.171 parts PEG 400, .030 parts of the diphenyl brightener, 0.850 parts PEG 6000, and 0.850 parts Glass H(Na23P21064).

Cotton fabrics were washed in solutions of the above compositions and the amount of brightener deposited on the fabrics was compared using a fluorimeter.

Fluorimeter Readings Control CompnA Initial fabric reading 10 9 After 2 wash cycles 173 168 After 3 wash cycles 194 192 The results show that Composition A which is within the scope of the invention is comparable to the control in fabric brightening.

EXAMPLE IV The detergent additive which was used in making Composition A in Example III was stored in an open jar at 90"F to determine if any color developed during storage. Readings were taken with a colorimeter.

Time Period L a b Initial 96.6 -0.08 -4.0 After2 weeks 93.5 +0.72 -4.1 After 4 weeks 93.8 +0.81 -4.6 After 7 weeks 95.4 +0.37 -1.4 Substantially no color change was noticed dung storage of the detergent additive. L represents whiteness (1 00=white 0=black), +a represents a red hue and -a represents a green hue, +b represents a yellow hue and -b represents a blue hue. For comparison, a detergent additive made as for Example Ill but without the hydroxyl-containing compound which renders the brightener white has readings as follows: L=96.9; a=-9.0; b=+14.8.

Composition A of Example Ill was also stored in laminated cartons at 90OF. After 6 weeks the detergent composition showed no essential color change.

Claims (11)

CLAIMS:

1. A detergent additive comprising: (A) from 0.1% to 1 5% of a fabric brightener selected from the group consisting of

wherein X, and X2 represent the radical SO3M or a halogen atom, R1-R4 can be the same or different and represent a C1-C4 alkoxy, alkanolamine, alkylamino, morpholino or aromatic amino group, and M represents a hydrogen atom, alkali metal or ammonium group; (B) from 0.1% to 45% of a hydroxyl-containing compound that combines with the fabric brightener to render it substantially white; and (C) from 40% to 99.8% of a normally solid, water-soluble organic coating material.

2. The detergent additive according to Claim 1 wherein the fabric brightener is selected from disodium 4,4'-bis(2 sulfostyryl) diphenyl, disodium 4,4' bis[(6-anilino-4-morpholino-1 ,3,5-triazin-2- yl)amino]stilbene-2,2'disulfonate, and mixtures thereof.

3. The detergent additive according to either one of Claims 1 and 2 wherein the hydroxylcontaining compound is selected from polyhydric alcohols, saccharides, ethoxylated alcohols having from 3 to 8 carbon atoms in the alkyl chain and an average of from 2 to 12 moles of ethylene oxide per mole of alcohol, polyethylene glycols having a molecular weight in the range of from 200 to 3500, polypropylene glycols having a molecular weight in the range of from 200 to 3500, and mixtures thereof.

4. The detergent additive according to Claim 3 wherein the hydroxyl-containing compound is polyethylene glycol having a molecular weight in the range of from 300 to 1 500.

5. The detergent additive according to any one of Claims 1-4 wherein the normally solid, watersoluble coating material is selected from polyethylene glycols and polypropylene glycols having a molecular weight of from 3500 to 30,000, the alkali metal salts of fatty acids having from 12 to 30 carbon atoms, linear and branched C10-C24 alcohols condensed with 9 to 50 ethylene oxide groups, alphatic carboxylic acids condensed with 20 to 50 ethylene oxide groups, aliphatic, cycioaliphatic and aromatic amides, C6-C18 alkyl phenols condensed with from 25 to 50 moles of ethylene oxide, and ethylene oxide-propylene oxide polymers containing 20% to 90% oxyethylene by weight.

6. The detergent additive according to Claim 5 wherein said coating material is polyethylene glycol having a molecular weight in the range of 3500 to 30,000.

7. The detergent additive according to Claim 6 wherein said coating material is polyethylene glycol having a molecular weight in the range of from 4000 to 8000.

8. A granular detergent composition comprising: (A) 0.5 to 1 5 parts by weight of a detergent additive according to any one of Claims 1-7 and (B) 85 to 99.5 parts by weight of detergent granules comprising: (I) 2% to 35% by weight of a surface-active agent selected from anionic, nonionic, ampholytic and zwitterionic surface-active materials; and (11) 10% to 65% by weight of a detergent builder salt

9. The granular detergent composition according to Claim 8 wherein the detergent builder is a water-soluble builder selected from alkali metal and ammonium tripolyphosphates, pyrophosphates, carbonates, silicates and nitrilotriacetates.

10. The granular detergent composition according to Claim 8 wherein the detergent builder is an insoluble aluminosilicate of the formula Naz(AlO2)z(SiO2)yXH2O wherein z and y are integers of at least 6, the molar ration of z to y is in the range of from 1.0 to 0.5, and x is an integer of from 1 5 to 264, said aluminosilicate having a calcium ion exchange capacity of at least about 200 mg. eqJg; a calcium ion exchange rate of at least about 2 grains/minute/gram; and a particle size of from 0.1 to 10 .

11. The granular detergent composition according to any one of Claims 8-1 0 wherein the surface-active agent is selected from C10-C14 linear alkylbenzene sulfonates, C12C20 linear alkyl sulfates, and condensation products thereof with from 1 to 4 ethylene oxide units, and C,2C,6 aliphatic alcohols condensed with an average of from 4 to 7 ethylene oxide groups.