AU624328B2 - Liquid detergent containing perborate bleach - Google Patents

Description

8th Jun DATED da Signature is) of ApPiliant (a) Se al of Comipany and SignaturesOof itsoOfficer,5 as prescribed by its Artiecca, of Associati n,

BY:

LOUIS C. GEBHARDT Registered Patent Attorney Form COMMONWVEALTH OF AUSTRALIA PATENTS ACT 1952-69 COMPLETE SPECI A1PN (OR IGINAL) Class Int. Class Application Number: Lodged: Complete Specification Lodged: roof r 0 roe 0 .?r~r;tV: 0*00 0 00 a 0 900 00 R~late~j Art: 0 000000 0 0 Accepted: Published: Adrass of Applicant: .Adiii Inventor: Address for Service: THE PROCTER GAMBLE COMPANY One Procter 'Gamble Plaza, Cincinnati., United States of America.

Ohio 45202, JOZEF PHILOMENA RAYMOND GEUDENS and TJAY YONG YAP EDWD. WATERS SONS, QUEEN STREET, MELBOURNE, AUSTRALIA, 3000.

Complete Specificatiop for the invention entitled: LIQUID DETERGENT CONTAINING PERBORATE BLEACH The following statementA Lst full description of this invention, including the best method of performing it known to US 1- 4. The basic application referred to in paragraph 2 of this Declaration first application made in a Convention country in respect of the invention the subject of the application.

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Liquid Detergent Containing Perborate Bleach J. Geudens T.Y. Yap Technical Field The present invention relates to aqueous liquid detergent compositions which contain perborate bleach in the form of small particles, particles having a number average particle diameter of from 0.5 to micrometers. The small particles are formed by in-situ recrystallization, preferably of perborate monohydrate.

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2 Background So-called heavy duty liquid detergent compositions as are commercially available at present typically do not contain a bleach. Dissolved peroxygen compounds, like hydrogen peroxide, interact with other components generally used in liquid detergents, like enzymes and perfumes.

T CInsoluble peroxygen bleach compounds present the problem of poor physical stability of suspensions made therewith.

DE-OS 35 11 515, published October 17, 1985, discloses non-aqueous liquid detergent compositions comprising sodiumperborate monohydrate and an activator for the perborate. FR 2.579.615, published October 3, 1986, discloses similar non-aqueous compositions which further comprise catalase inhibitors. The compositions exemplified in these two patents do not contain anionic surfactants.

J. Dugua and B. Simon, "Crystallization of Sodium Perborate from Aqueous Solutions", Journal of Crystal Growth 44 (1978), 265-286, discusses the role of surfactants on the nucleation and crystal growth of sodium perborate tetrahydrate.

It is an object of the present invention to provide aqueous liquid detergent .compositions containing perborate particles having a number averge particle diameter of from 0.5 micrometer to 20 micromoters. It is a further L 1 3 object of this invention to provide a process by which particles in the desired particle size range are formed i.n itu.

Summary of the Invention According to the present invention there is provided an aqueous liquid detergent composition having a pH of at least 8, comprising: a. from 5% to 60% of an organic, non-soap anionic surfactant; b. from 5% to 15% of a builder selected from dodecenyl succinic acid, tetradecenyl succinic acid; dodecyl succinic acid; an 80:20 mixture of tartrate monosuccinate and tartrate disuccinate; citric acid; and mixtures thereof; nurmbeO\ c. from 1% to 40% of a perborate bleach in the form of particles having a ei average particle diameter of from 0.5 micrometer to 20 micrometers, said particles formed by in situ recrystallization.

The invention also provides a process for preparing the liquid detergent composition described above, comprising: o" 15 a. mixing water with the anionic detergent and the builder; b. adding a perborate compound to said admixture; and Sc. stirring until the required particle diameter is obtained by in situ recrystallization of the perborate compound.

Preferred liquid detergent compositions further comprise from 5% to 70% of a water-miscible organic solvent. The preferred water-miscible organic solvents are the low molecular weight monohydric alcohols; the most preferred of these solvents is ethanol.

B 44 Preferred herein are detergent compositions having a pH of at least 9, more preferably at least 25 Detailed Description of the Invention The present invention addresses the problem of 0 0 t 0 4 i i 'NT O A f 'I i formulating an aqueous liquid detergent composition having suspended therein small particles of a perborate bleach.

For reasons of physical stability it is necessary that the perborate particles have a number average particle diameter of from 0.5 to 20 micrometers. It is not advisable to make such small particles by grinding, because of explosion risks. Moreover, such small particles in a dry state would pose serious industrial hygiene and safety problems.

It has now been discovered that the required small perborate particles can be formed by in situ recrystallization in the presence of at least 5% of an organic, non-soap, anionic surfactant and at least 5% of a detergent builder.

t tt t I Percentages as used herein are percentages by weight Sof the liquid detergent composition. Weight percentages of the perborate are calculated as perborate monohydrate, even through the particles may be different in composition the tetrahydrate).

The term "in situ recrystallization" relates to processes whereby perborate particles are formed from larger particles in the presence of the water/anionic surfactant/detergent builder matrix. This term therefore encompasses processes involving chemical reactions, as when sodium perborate is formed by reacting stoichiometric amounts of hydrogen peroxide and sodium metaborate.

In one embodiment of the invention, a perborate compound, sodium perborate tetrahydrate or sodium perborate monohydrate, is added to an aqueous liquid comprising the anionic surfactant and the detergent builder. The resulting slurry is stirred. During this stirring the perborate compound undergoes a process of Ill i dissolution/recrystallization. Due to the presence of the anionic surfactant and the detergent builder this dissolution/recrystallization process results in particles having the desired particle diameter.

As the monohydrate is more susceptible to recrystallization, the monohydrate is preferred for this embodiment of the invention. Particle diameters herein are number average particle diameters, unless otherwise specified. Number average particle size diameters may be determined using well-known techniques, e.g. the Coulter counter method.

S4 1 C In a second embodiment of the invention the perborate compounds is formed in situ by chemical reaction. For example, sodium metaborate is added to an aqueous liquid comprising the anionic surfactant and the detergent builder. Then a stoichiometric amount of hydrogen peroxide is added while stirring. Stirring is continued until the chemical reaction is complete.

iPreferred liquid detergent compositions contain, in S addition to water, a water-miscible organic solvent. The solvent reduces the solubility of perborate in the liquid phase and thereby enhances the chemical stability of the composition.

<Ii 'It is not necessary that the organic solvent be fully miscible with water, provided that enough of the solvent mixes with the water of the composition to affect the solubility of the perborate compound in the liquid phase.

The water-miscible organic solvent must, or course, be compatible ith the perboracompi ith t p ompound at the pH that is used. Therefore, polyalcohols having vicinal hydroxy groups 1,2-propanediol and glycerol) are less desirable.

6 Examples of suitable water-miscible organic solvents include the lower aliphatic monoalcohols, and ethers of diethylene glycol and lower monoaliphatic monoalcohols.

Preferred solvents are ethanol, iso-propanol, 1-methoxy 2-propanol and butyldiglycolether.

Although the presence or absence of other ingredients plays a role, the amount of available oxygen in solution is largely determined by the ratio water organic solvent. The smaller this ratio the more organic solvent is used in the solvent system), the lower the amount of available oxygen in solution. Although this is good for stability of the bleach system, it is less desirable for a good solubility of other components (e.g.

electrolyte, anionic surfactants).

@0*00 o In practical terms, the ratio water organic solvent is, for most systems, in the range from 3:1 to 1:3, preferably from 2:1 to 1:2.

S 0 4 As it is believed that the ionic strength of the composition affects the dissolution/recrystallization process, preferred compositions have an ionic strength of at least 0.8 moles/liter, preferably from 2 to moles/liter.

Ionic strengths are calculated on the assumption that all ionic materials present in the composition are fully Sdissociated.

The liquid detergent compositions herein contain from to 60% eo thC liquid deCtorzgnt comp4ition, preferably from 15% to 40%, of an organic surface-active agent selected from nonionic, anionic, and zwitterionic surface-active agents and mixtures thereof. At least of the detergent composition must be anionic surfactant.

i 7 Synthetic anionic surfactants can be represented by the general formula R SO M wherein R represents a hydrocarbon group selected from the group consisting of straight or branched alkyl radicals containing from about 8 to about 24 carbon atoms and alkyl phenyl radicals containing from about 9 to about 15 carbon atoms in the Salkyl group. M is a salt forming cation which typically is selected from the group consisting of sodium, potassium, ammonium and mixtures thereof.

A preferred synthetic anionic surfactant is a water-soluble salt of an alkylbenzene sulfonic acid containing from 9 to 15 carbon atoms in the alkyl group.

o"o Another preferred synthetic anionic surfactant is a 0 o- water-soluble salt of an alkyl sulfate or an alkyl polyethoxylate ether sulfate wherein the alkyl group "o contains from about 8 to about 24, preferably from about 0 10 to about 18 carbon atoms and there are from 0 to about preferably from 0 to about 12 ethoxy groups. Other suitable anionic surfactants are disclosed in U.S. Patent 4,170,565, Flesher et al., issued October 9, 1979.

o The nonionic surfactants are conventionally produced 0 by condensing ethylene oxide with a hydrocarbon having a reactive hydrogen atom, a hydroxyl, carboxyl, or amido group, in the presence of an acidic or basic catalyst, and include compounds having the general formula

RA(CH

2 CH 0) H wherein R represents the hydrophobic moiety, A represents the group carrying the reactive hydrogen atom and n represents the average number of ethylene oxide moieties. R typically contains from about 8 to 22 carbon atoms. They can also be formed by the condensation of propylene oxide with a lower molecular weight compound. n usually varies from about 2 to about 24.

i i I r 1 -f -8- The hydrophobic moiety of the nonionic compound is preferably a primary or secondary, straight or branched, aliphatic alcohol having from about 8 to about 24, preferably from about 12 to about 20 carbon atoms. A more complete disclosure of suitable nonionic surfactants can be found in U.S. Patent 4,111,855. Mixtures of nonionic surfactants can be desirable.

Zwitterionic surfactants include derivatives of aliphatic quaternary ammonoum, phosphonium, and sulphonium compounds in which the aliphatic moiety can be straight or branched chain and wherein one of the aliphatic S*o substituents contains from about 8 to about 24 carbon So atoms and another substituent contains, at least, an anionic water-solubilizing group. Particularly preferred zwitterionic materials are the ethoxylated ammonium sulfonates and sulfates disclosed in U.S. Patents 3,925,262, Laughlin et al., issued December 9, 1975 and o *O 3,929,678, Laughlin et al., issued December 30, 1975.

o Semi-polar nonioni.c surfactants include water-soluble S, amine oxides containing one alkyl or hydroxy alkyl moiety of from about 8 to about 28 carbon atoms and two moieties selected from the group consisting of alkyl groups and hydroxy alkyl groups, containing from 1 to about 3 carbon i atoms which can optionally be joined into ring structures.

Suitable anionic synthetic surface-active salts are selected from the group of sulfonates and sulfates. The like anionic detergents are well-known in the detergent arts and have found wide-spread application in commercial detergents. Preferred anionic synthetic water-soluble sulfonate or sulfate salts have in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms.

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i -9- Examples of such preferred anionic surfactant salts are the reaction products obtained by sulfating C8-C18 8 18 fatty alcohols derived from tallow and coconut oil; alkylbenzene sulfonates wherein the alkyl group contains from about 9 to about 15 carbon atoms; sodium alkylglyceryl ether sulfonates; ether sulfates of fatty alcohols derived from tallow and coconut oils; coconut fatty acid monoglyceride sulfates and sulfonates; and 'water-soluble salts of paraffin sulfonates having from about 8 to about 22 carbon atoms in the alkyl chain.

Sulfonated olefin surfactants as more fully described in t id W e.g. U.S. Patent Specification 3,332,880 can also be S used. The neutralizing cation for the anionic sunthetic ~sulfonates and/or sulfates is represented by conventional cations which are widely used in detergent technology such S as sodium and potassium.

A particularly preferred anionic synthetic surfactant Scomponent herein is represented by the water-soluble salts of an alkylbenzene sulfonic acid, preferably sodium alkylbenzene sulfonic acid, preferably sodium alkylbenzene Ssulfonates having from about 10 to 13 carbon atoms in the alkyl group.

Oc( A preferred class of nonionic ethoxylates is represented by the condensation product of a fatty alcohol having from 12 to 15 carbon atoms and from about 4 to moles of ethylene oxide per mole of fatty alcohol.

Suitable species of this class of ethoxylates include the condensation product of C 12 -C15 oxo-alcohols and 10 7 or 9 moles of ethylene oxide per mole of alcohol; the condensation product of narrow cut C oxo-alcohols and 7 or 9 moles of ethylene oxide per mole of fatty(oxo)alcohol; the condensation product of a narrow cut C 12

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13 fatty(oxo)alcohol and 6,5 moles of ethylene oxide per mole of fatty alcohol; and the condensation products of a C 0-C14 coconut fatty alcohol with a degree of ethoxylation (moles EO/mole fatty alcohol) in the range from 5 to 8. The fatty oxo alcohols while mainly linear can have, depending upon the processing conditions and raw material olefins, a certain degree of branching, particularly short chain such as methyl branching.

e o A degree of branching in the range from 15% to o o (weight%) is frequently found in commercial oxo alcohols.

oe 0 0 o 00 Preferred nonionic ethoxylated components can also be o represented by a mixture of 2 separately ethoxylated nonionic surfactants having a different degree of ethoxylation. For example, the nonionic ethoxylate S0 surfactant containing from 3 to 7 moles of ethylene oxide 0 per mole of hydrophobic moiety and a second ethoxylated species having from 8 to 14 moles of ethylene oxide per mole of hydrophobic moiety. A preferred nonionic ethoxylated mixture contains a lower ethoxylate which is the condensation product of a C 12

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15 oxo-alcohol, with up to 50% (wt) branching, and from about 3 to 7 moles of ethylene oxide per mole of fatty oxo-alcohol, and a Shigher ethoxylate which is the condensation product of a S6 C 16

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19 oxo-alcohol with more than 50% (wt) branching and from about 8 to 14 moles of ethylene oxide per mole of branched oxo-alcohol.

The liquid detergent.compositions herein optionally contain a fatty acid component. Preferred saturated fatty acids have from 10 to 16. more preferably 12 to 14 carbon

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Detergent enzymes can be used in the liquid detergent compositions of this invention. In fact, one of the desirable features of the present compositions is that they are compatible with such detergent enzymes. Suitable enzymes include the detergent proteases, amylases, lipases and cellulases. Enzymatic stabilizing agents for use in aqueous liquid detergents are well known. Preferred herein is a salt of formic acid, sodium formate.

The amount of this stabilizing agent typically rances from .o 0.5% to 2%.

o 09 0. c The S0-Peeerred compositions contain an inorganic or organic oo a builder. Examples of inorganic builders include the 0o0 o phosphorous-based builders, sodium tripolyphosphate.

sodium pyrophosphate, and aluminosilicates (zeolites).

Examples of organic builders are represented by 0o polyacids such as citric acid, nitrilotriacetic acid, and mixtures of tartrate monosuccinate with tartrate Sdiscuccinate. Preferred builders for use herein are citric acid and alk(en)yl-substituted succinic acid compounds, wherein alk(en)yl contains from 10 to 16 carbon atoms. An example of this group of compounds is dodecenyl succinic acid. Polymeric carboxylate builders inclusive 0 Sof polyacrylates, polyhydroxy acrylates and Spolyacrylates/polymaleates copolymers can also be used.

The compositions herein can contain a series of further optional ingredients which are mostly used in additive levels, usually below about Examples of the like additives include polyacids, enzymes and enzymatic stabilizing agents, suds regulants, opcifiers, agents to improve the machine compatibility in relation to Senamel-coated surfaces, bactericides, dyes, perfumes, Sbrighteners and the like.

il f i: r 1:i i. S12 The liquid compositions herein can contain further additives of a level from 0.05 to 2%.

These additives include polyaminocarboxylates such as ethylenediaminotetracetic acid, diethylenetriaminopentacetic acid, ethylenediamino disuccinic acid or the water-soluble alkali metal salts thereof. Other additives include organo-phosphonic acids; particularly preferred are ethylenediamino tetramethylenephosphonic acid, hexamethylenediamino tetramethylenephosphonic acid, diethylenetriamino ooo pentamethylenephosphonic acid and @DOO aminotrimethylenephosphonic acid.

0 Go 0, i Bleach stabilizers such as ascorbic acid, dispicolinic 0° acid, sodium stannates and 8-hydroxyquinoline can also be 0o o000 ooooo included in these compositions, at levels between 0.01 and 1%.

The beneficial utilization of the claimed compositions i *0 under various usage conditions can require the utilization of a suds regulant. While generally all detergent suds regulants can be utilized preferred for use herein are alkylated polysiloxanes such as dimethylpolysiloxane also frequently termed silicones. The silicones are frequently used in a level not exceeding most preferably between 0.1% and It can also be desirable to utilize opacifiers inasmuch as they contribute to create a uniform appearance of the concentrated liquid detergent compositions.

Examples of suitable opacifiers include polystyrene commercially known as LYTRON 621 manufactured by MONSANTO CHEMICAL CORPORATION. The opacifiers are frequently used in an amount from 0.3% to 13 The liquid detergent compositions of this invention further can comprise an agent to improve the washing machine compatibility, particularly in relation to enamel-coated surfaces.

It can further be desirable to add from 0.1% to 5% of known antiredeposition and/or compatibilizing agents.

Examples of the like additives include sodium carboxymethylcellulose; hydroxy-C -alkylcellulose; 1-6 polycarboxylic homo- or copolymeric ingredients, such as polymaleic acid, a copolymer of maleic anhydride and methylvinylether in a molar ratio of 2:1 to 1:2; and a copolymer of an ethylenically unsaturated monocarboxylic acid monomer, having not more than preferably 3 or 4 f c carbon atoms, for example (methy)-acrylic acid, and an S ethylenically unsaturated dicarboxylic acid monomer having not more than 6, preferably 4 carbon atoms, whereby the molar ratio of the monomers is in the range from 1:4 to 4:1, said copolymer being described in more detail in EUROPEAN Patent Application 0 066 915, filed May 17, 1982.

The following examples illustrate the invention and S. facilitates its understanding.

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t a i i t *'K aS The following statement ;s full description of this invention, including the best method of performing it known to us

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14 Liquid detergent compositions are prepared by mixing th. listed ingredients in the stated proportions: Ingredients Composition (weight) I II III IV U (If C r ret

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c~'ttC C C 4 4 1 I It 4 1 1 It Ct

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C (CC C t C C I C C CCtt(I C I Water Ethanol Linear dlodecylbenzene sulf'onic acid Condensation product of 1 mole of C 1- Cisoxo alcohol and 7 moles of ethylene oxide Sodium cocoyl. sulfate Dodlecenyl succinic acid Citric acid Oleic acid Protease Diethylenetriamine pentamethylene phosphonic acid Sodium formate Sodium perborate monohydrate Sodium hydroxide (to adjust to) pH Perfum~e, minors it) sodium perbotrate f~rh1r~ 33 32 26 23 34 14 15 18 22 1 1 12 10 8 8 12 7 2 13 0.8 3. 3 0.3 0.05 0.9 10 9.

3 10 1 4 0.5 0.85 1 10 0 8 4 2 2 15 1 0.8 2 o 7 2 13 0.8 3 .3 0.05 0.05 0.05 1 12 10 9 10 9 11 8.2 balance.-.

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It The sodium perborate compound is added after all the other ingredients have been mixed. The composition is stirred overnight.

The resulting recrystallized perborate particles have a number average particle diameter of about 7 micrometers.

The following compositions are prepared in the same manner Ingredients Composition (weight Water Ethanol -Methoxy-2-propanol Isopropanol Butyldiglycolether Linear dodecylbenzene sulfonic acid Nonionic surfactant Sodium cocosulfate

TMS/TDS*

Dodecenyl succinic acid Tetradecenylsuccinic acid Coconut fatty i,.id Oleic acid Citric acid Ethylene diamine tetraacetic acid Sodium tripolyphosphate Sodium perborate tetrahydrate Sodium perborate monohydrate Sodium formate Protease Sodium hydroxide to pH Perfume, minors VI VII 28 27 -7 14 3.5 VIII IX X 28 22 7 8 7 7 12 7 2.5 9 4 3.6 0.9 0.5 7 2.5 16 4.0 0.5 0.5 13 3 .5 3.0 2.0 10 9 8 7 3,0 6. 5 8. 5 2.0 0.8 1 15.0 10.4 0.8 0.6 10 9 1.0 0.8 13 1.0 0.5 I1I 13 0.5 0.5 10, 5 19 0.6 10.5 *80:20 mixture of tartrate monosuccinate and tartrate disciiccinatp *Diethyletetriamino pentamethylene phosphonic acid I 0itify thlwt tViN and the preceding pagen Mr E, ttrua ao 0 ut L. copy of pages (Of~I th SpOO11aikoOroIgnaIIy lodged.

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Claims (7)

1. An aqueous liquid detergent composition having a pH of at least 8, comprising: a. from 5% to 60% of an organic, non-soap anionic surfactant; b. from 5% to 15% of a builder selected from dodecenyl succinic acid, tetradecenyl succinic acid; dodecyl succinic acid; an 80:20 mixture of tartrate monosuccinate and tartrate disuccinate; citric acid; and mixtures thereof; c. from 1% to 40% of a perborate bleach in the form of particles having a weigt average particle diameter of from 0.5 micrometer to 20 micrometers, said d. optionally from 5% to 70% of a water-miscible organic solvent

2. A process for preparing the liquid detergent composition of claim 1 comprising: a. mixing water with the anionic detergent and the builder; 4, Sb. adding a perborate compound to said admixture; and 9, c. stirring until the required particle diameter is obtained by in situ recrystallizatioi of the perborate compound. te *e

3. A process according to claim 2 wherein the perborate is selected from sodium perborate tetrahydrate and monohydrate.

4. A process for preparing the liquid detergent composition of claim 1 comprising adding sodium metaborate to an aqueous liquid comprising the anionic surfactant and the l builder, and then adding a stoichiometric amount of a peroxide, while stirring until completion of the reaction.

A process according to claim 4 wherein the perioxide is hydrogen peroxide or Ssodium peroxide.

6. A process according to any one of the preceding claims, wherein a water-miscible organic solvent is also added. e WIN 2 Ii 17

7. A process according to claim 6 wherein said water-miscible organic solvent is ethanol. DTDthis 25th day of March, 1992 THE PROCTER GAMBLE COMRANY WATERMARK PATENT TRADEMARK ATTORNEYS THE ATRIUM 290 BURWOOD ROAD HAffrHORN VICTORIA 3122 AUSTRAUA 9tt* S 0@ 0 0 S., 0 4 4 S 9,4.44 S. S S S. 94Sf 44 5* 4 4* SI 4 44 0 4* 0 a 4 44 AUl 756083 .WPC(DOC.O1 3) LCG:EK