CA1322705C - Process for making concentrated surfactant granules - Google Patents
Process for making concentrated surfactant granulesInfo
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- CA1322705C CA1322705C CA000604216A CA604216A CA1322705C CA 1322705 C CA1322705 C CA 1322705C CA 000604216 A CA000604216 A CA 000604216A CA 604216 A CA604216 A CA 604216A CA 1322705 C CA1322705 C CA 1322705C
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- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
- C11D17/06—Powder; Flakes; Free-flowing mixtures; Sheets
- C11D17/065—High-density particulate detergent compositions
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- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Wood Science & Technology (AREA)
- Organic Chemistry (AREA)
- Detergent Compositions (AREA)
- Cosmetics (AREA)
Abstract
PROCESS FOR MAKING CONCENTRATED SURFACTANT GRANULES
ABSTRACT OF THE DISCLOSURE
The present invention relates to an energy saving process for preparing concentrated or condensed surfactant granules. High active surfactant paste is chilled and granulated using fine dis-persion mixing. The product surprisingly provides discrete, uniform (200-2,000 micron) granular particles. The granules of the present invention are preferably pure surfactant to be used as an intermediate in a final detergent formulation.
ABSTRACT OF THE DISCLOSURE
The present invention relates to an energy saving process for preparing concentrated or condensed surfactant granules. High active surfactant paste is chilled and granulated using fine dis-persion mixing. The product surprisingly provides discrete, uniform (200-2,000 micron) granular particles. The granules of the present invention are preferably pure surfactant to be used as an intermediate in a final detergent formulation.
Description
~ 32~7~
PROCESS FOR MAKING CONCENTRATED SURFACTANT GRANULES
Daniel L. Strauss Charles L. Stearns Thomas E. Lobaugh FIELD OF INVENTION
The present invention relates to a process for preparing concentrated ~condensed) surfactant granules.
BACKGROUND OF THE INVENTION
Granular surfactant compositions are principally prepared by spray or drum drying. In the spray drying process the surfactant components, plus perhaps salts and builders, are mixed with as much as 35-50% waker to form a slurry. The slurry obtained is heated and spray dried9 which is expensive~
Such spray drying requires 30-40 wt.% of the water to be removed. The spray drying equipment used is expensive. The granule obtained has good solubility but a low bulk density, so the packing volume is large. Th~ particles also may be sticky, particularly when hot, and thus wall buildup is an additional problem. There are other known disadYantages in preparing gran-ular materials by spray drying, such as environmental concerns and heat sensitivity. An agglomeration process, on the other hand, would be cleaner, as well as less expensive, both in terms of equipment and operat~ng costs.
Ther~ are many prior art nonspray-drying processes which produce surfactant granule~. Most, howaver, require mixing of the surfactant with other materials such as inorganic salts or alumi-nosilicate-type materials. Some other processes require use of an acid form of the surfactan~ to work. In most cases, a diluted surfac~ant particle is obtalned. The major problem with the use of a high active surfaotant paste as a starting material in a one step granulation process is its stickiness.
In U.S. Pat. No. 4,515,707, Brooks, issued May 7, 1985;
Japanese laid-open Appln. No. 183540/19B3, Kao Soap Co., Ltd., filed S@pt. 30, 1983; and Japanese Sho. 61-118500, Lion K.K., 227 ~ ~
June 5, 1986, high shear and/or cold mixing processes are dis-closed. Typically, excess carbonate is required (2-10 molar excess) to assure reasonable conversion of the surfactant acids.
Excess carbonate adversely drives up the wash water pH to the very alkaline range which can be undesirable, particularly for some nil-phosphate formulas and formulas containing peracid bleaches.
Such high shear and cold mixing processes are known, but they have drawbacks, e.g., some require an extra grinding step or some other action, as well as the addition of other ingredients, primarily solids. Others use a dry neutrali~ation technique for mixing the acid form of the surfactant with sodium carbonate.
A practlcal problem with the use of a surfactant acid form is that it requires immediate use after it is made, or cool tempera-ture storage, for such highly reactiYe acids, such as the alkyl sulfate acids9 are subject to degradation unless cooled. They also tend to undergo hydrolysis during storage, forming free sulfurie acid and alcohol. In practical terms, such prior art processes require close coupling of surfactant acid production with granulation which requires an additional capital investment.
~n U.S. Pat. No. 4,162,994, Ko~alchuk, issued July 31, 1~7~, it is disclosed that calcium salts are re~uired to overcome problems in process~ng by nonspray drying (i.e.~ mechanical) means ~ormulations based on sodium salts of anionic surfactants and certain nonionic surfactants. A drawback to that process is that insoluble calc~um salts can lower the solubility of the formu-lation, which is of particular importance in stress situations, such as in pouch-type executions.
U.S. Pat. No. 4,427,417, Porasik, issued Jan. 24, 1~84, discloses preparing granular detergent composit;ons from hydrat-~o abl e particul ate detergent salts, etc., under conditlons insuring complete hydration and agglomerating them into storage stable, dry, pourabl e agglomerates.
SUMMARY OF THE INV~NTION
The present invention relates to an economical process for making a dense, concentrated surfactant granule from a high active surfactant paste using fine dispersion cold granulation.
A
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- OBJECTS OF THE_INVENTION
An important object of the present invention is to make a denser and more concentrated surfactant granular product by an agglomeration process without an expensive drying step. Another object is to provide a more concentrated surfactant granule which can be stored and then admixed with other ingredients to provide a final end product. Another object of the process of this inven-tion is to provide a formulated granule containing higher total surfactant levels than typically obtained via other means. Yet another object of the present invention is to prepare a very high active surfactant granule essential free of hydrated inorganic salts. Other objects of the present invention will be apparent in view of the following.
DETAILED DESCRIPTION OF THE INVENTIQN
The process of the present invention comprises fine dis-persion mixing and cooling o~ a high active surfactant paste to provide a very concentrated surfactant granllle. Most high active surfactant pastes are too tacky at normal m;xing temperatures to successfully granulate using fine dispersion mixing. So the high active surfactant paste is cooled as needed to a granulation tem-perature while mixing. Iarge discrete particles (granules) are surprisingly formed right in the mixer. Thus "cold" granulation of a hlgh surfactant past is achleved.
The granulation temperature, according to the present inven-tion9 ranges from about -65-C to 25C using a critical fine dispersion mixing tip speed of from about 5 m/sec. to about 50 m/sec. Dry ice is a preferred cooling means.
A benefit of the present invention is that the preferred 30 granules made according to the present invention are large, essentially pure surfactant granules. They preferably have a bulk density of from about 0.4 to about 1.1 9/CC9 more preferably from about 0.5 to about 0.8 g/cc. The weight aYerage particle size of the preferred particles of th~s invention are from about 200 to about 2,000 mkrons. The more preferred granules have a particle size range of from 300 to 1,200 microns. Yields of 25% to &5% in these ranges can be achie~ed. A second brief mixins increases ~3~27~
y;e!ds of granular particles in these preferred ranges. Oversized and undersized particles can also be recycled.
The more preferred granulation temperatures of the high active surfactant paste ranges from about -40C to about 10C, and most preferably from about -30C to about 0C. More details of the present invention are highlighted below.
The resultant surfactant granules made by the process of the present invention can comprise a combination of all, or substan-tially all, of the ingredients Qf the total composition or th~y can be used as an intermediate. Thus, such granules greatly reduce or even eliminate tha need to admix additional materials for a final detergent formulation. Also, the possibility of segregation of ingredients during shipping, handling or storage is greatly reduced, especially if only minor quantities of other materials of differing particle si~es or densities are to be included.
Separately, the concentrated granule of this invention can be admixed with detergent granules produced by more conventional means to increase the total surfactant level in a final formu-lation.
Methods of CoolinqLthe Hlq~!-Active Surfactant Paste Any suitab1e method of coollng the high active surfactant paste to a granulation temperature can be used. Cooling jackets or coils can be integrated around or into the mixer. Chipped dry ice or liquid CO~ can be added or ~njected into the uniform paste.
The idea is to lower the high active surfactant paste temparature to a granulation temperature so that it can be finely dispersed or "granulated" into discrete particles.
_ste Viscositv and Processinq Two important parameters of the high active surfactant pastes which can affect the parameters of ~he mixing and granulation step of the present invention are the paste temperature and the paste viscosity. The viscosity is a function of surfactant concen-tration and its temperature. The high active surfactants of the present invention have viscosities which range from about 10,000 cps to 10,000,000 cps; preferably, from about 70,000 to about - - -~2~7~
7,000,000 cps; and more preferably from about 100,000 to about 1,000,000 cps. These viscosities are measured at a temperature of about 50'C for the present invention.
The high active surfactant paste can be introduced into the mixer at an initial temperature in the range of about 5-70C, preferably about 2U-30C. Higher temperatures reduce their viscosities but a temperature greater than about 70C can lead to poor initial mixing due to increased product stickiness.
The process of the present invention surprisingly forms large, but usable~ granules, preferably in the 200 to 1200 micron range. Such large granules are preferred, particularly if the surfactant granule is to be admixed with other materials which have a tendency to be dusty. Particles of similar size are preferred to minimize segregation. No extra grinding step is required or desirable. In general, larger particles are less dusty, which is important in many consumer applications, especi-ally those which comprise porous, unitized dose pouch-like products. Such porous products are designed: ~1) to avoid con-sumer contact with the product ilnd (2) to reinforce the con-venience and nonmessiness perceptions of a unit ked pouch form.
- If desired, granules of insufficilent size can be screened after drying and recycled to the fine di<;persion mixer.
The Fine Pisper$lQ~ ~ting and Gran~Jation Unless otherwise specified, the terms "fine dispersion mixing" and/or` "granulation," as used herein are synonymous and mean mixing and granulating of a htgh active surfactant paste in a fine dispersion mixer using a blade tip speed of from about 5 m/sec. to about 50 m/se. The total residence time of the mixing and granulatlon process is preferably in the order of from 0.1 to 10 m1nutes, more pre~erably 0.5-8 and most preferably 1-6 minutes.
The more preferred mixing and granulation tip speeds are about 10-40 m/sec. and about 15-35 m/sec.
The Little~ord Mixer, Model #FM-130-D-12, with internal chopping blades and the Cuisinart~ Faod Processor, Model #DCX-Plus, with 7.75 inch (19.7 c-) blades are two examples of suitable mixers. Any other mixer with fine dispersion mixing and granu-lation capability and which preferably has a residence time in the 132~7~
order of 0.1 to 10 minutes can be used. The i'turbine type"
impeller mixer, having several blades on an axis of rotation, is preferred. The invention can be practiced as a batch or a con-tinuous process.
The mixer must finely disperse the paste and, if desired, the other ingredients. When the contents of the mixer are cooled, the mixing ~ust be conducted at said fine dispersion tip speed in order to granulate the surfactant into discrete particles. Care must be taken not to use too low or too high of a tip speed at the granulation step. While not being bound to a theory, ~Itoo high a shear" is believed to prevent granulation because of a wide variety of str~sses, e.g., a broader particle size distribution caused by the high~r tlp speeds with a higher level of fines generated. Also, too high of a tip speed increases the tempera-ture of the material and additional cooling is required.
Care must be taken not to overload any fine dispersion mixer with two much or too little surfactant paste material. If there is more than one material the results ara poor mixing and unsat-isfactory granulation. Thus, care must be taken to load the mixer with a proper level of paste material so that satisfactory mixing and granulation are achieved. Sim~lar to too low of a tip speed, overloading the mixer results in poor dispersion, reduced uni-formity and large lumps. On the other hand, too high of a tip speed increases the production of undesirable fines.
The work input required for fine d;spersion mixing in the practice of the present invention varies with: (1) the type of fine dispersion mixer used, (2) the mixer loading level, (3) the viscosity of the paste material, and ~4) the amount and the type of dry solids used~ if any. E.g., the Total Work required for mixing and granulation of several preferred paste materials using a laboratory Cuisinart food processor, Model ~DCX-Plus varied from about 7 BTU's to about 16 BTU's per pound of paste material. The rorresponding I~crem~ntal Work varied from about 0.4 BTU's to about 2.6 BTU's per pound of paste material. Tha No Load Work for the Cuisinart food processor ~s about 0.2 BTU's per second. The Cuisinart food processor has a single 19.7 cm flat horizontal ~227~
propeller and is operated at 1800 rpm, which is a tip speed of about 1~.55 m/sec.
The Total Work required to mix and granulate the surfactant paste of the present invention can vary from about 3 BTU's to about 30 BTU's per pound of material depending on viscosity, load, etc. A preferred range is from about S BTU's to about 20 BTU's per pound. These BTU ranges in kilogram of material are, respec-tively, from about 6.6 to 66, and from about 11 to 44 BTU/Kg.
Some benefits of fine dispersion mixing and granulation include: (1) a lower level of granulated fines; (2) a more uniform granular particle size distribution; an~ (3) a hlgher density granule than a granular product made with standard agglomeration-type mixers, such as pan type mixers.
Hiqh Active Surfactant Paste The activity of the aqueous surfactant paste is at least 50%
and can go up to about 98%; preferred activities are: 60-80% and 65-75%. The balance of the paste is primarily water but can include a processing aid such as mineral oil. The resultant con-centrated surfactant granules can be added to dry detergencybuilders or conventionally agglomerated with blnders with these builders or other materials to yield desired finlshed formula compositions.
In the process of the present invention, it is preferable to use higher active surfactant pastes to minlmize the total water level in the system during mixing and granulating~ The benefits of lower water levels are to allow for (1) higher levels of other liquids in the formula without causing stickiness; (2) less cooling, du~ to higher granulation temperatures; and (3) less granular drying to meet final moisture limits.
Tt is important that the mo~stur2 or solvent (hereinafter referred to as "molsture") content of the high activ~ surfactant should not exceed 50%. The total moisture can range from about 2%
to about 50%, but is preferably from about 10% to about 40%, and more preferably from about 15Yo to about 30%. The lower granu-lation temperatures are used for the higher mois~ure-containing ~L322~
pastes. Conversely, the higher granulation temperatures can be used for lower moisture pastes.
Paste compositions which have lower moisture contents of below 5X~ e.g., about 1% to 4,~, can contain an effective amount of an organic liquid solvent or processing aid. Examples of such aids are selected from suitable organic liquid, including ~ineral oil, glycerin, short chain alcohols, and the like, and mixtures thereof. The processing aid preferably can be used at a level of "0.5% to 20~," more preferably about 1-lOYo; most preferably about 2-579 by weight of the paste.
The desired moisture content of the surfactant granules of this inYention can be adjusted by adding other deslred dry ingre-dients prior to cooling and granulation. Thus, additional "drying" is unnecessary in low moisture formulations. ~hen desirable, drying the discrete granules can be accomplished in a standard fluid bed dryer. Tha idea here is to provide a free flowing granule with a desired moisture content of 0.5-10%, preferably 1-5%.
lhe aqueous surfactant paste contains an organic surfactant selected from the group consisiting of anionic, zwitterionic, ampholytic, nonionic and cationic surfactants, and mixtures thereof. Anionic surfactants are preferred. Surfactants useful herein are listed ln U.S. Pat. No. 3,664,961, Norris, issued May 23, 1972, and in U.S. Pat. No. ~919,678, Laughlin et al., issued Dec. 30, 1975.
Useful cationic surfactants also include those described in U.S.
: Pat. ~o. 4,222,905, Cockrell, issued Sept. 16, 19~0, and in U.S.
Pat . No . 4, 2~9, 659, Murphy, i ssued Dec ~ 16, 1980 ~
The following are representative ~0 examples of surfactants useful in the present compositions.
~ater-soluble salts of the higher fatty acids, i.e., "soaps,"
are useful anionic surfactants in ~he compositions herein. This includ~s alkali metal soaps such as the sodium, potassium, ammo-nium, and alkylolammonium salts of higher fatty acids containing from about 8 to about 24 carbon atoms, and preferably from about 12 to about 18 carbon atoms~ Soaps can be made by direct saponi-ficatio~ of fats and oils or by the neutralization of frse fatty acids. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, ..
.. ..
~t~
, . .
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g i.e., sodium or potassium tallo~ and coconut soap.
Useful anionic surfactants also include the water-soluble salts, preferably the alkali metal, ammonium and alkylolammonium salts, of organic sulfuric reaction products having in their molecular structure an alkyl group containing from about 10 to about 20 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 are the sodium and potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (Cg-C1g carbon atoms) such as those produced by reducing the glycerides of tallow or coconut oil; and the sodium and potassium alkyl benzene sulfonates in which the alk~l group contains from about 9 to about 15 carbon atoms, in straight or branched chain configuration, e.g., those of the type described in U.S. Pat. Nos. 2,220,09g and 2,477,383. ~specially valuable are linear straight ~hain alkyl benzene sulfonates in which the average number of carbon atoms in the alkyl yroup is from about 11 to 13, abbreviated ax Cll-C13 LAS.
Other anionic surfactants herein are the sodium alkyl glyc-eryl ether sulfonates, espectally 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 alkyl phenol ethylene oxlde cther sulfates containing from about 1 to about 10 units of ethylene oxide per molecule and wherein the alkyl groups contain from about 8 to about 12 carbon atoms; and sodium or potassium salts of alkyl ethylene oxide ether sulfates cont~ining from about 1 to about 10 units of ethylene oxide per molecule and wherein the alkyl group contains from about 10 to about 20 carbon atoms.
Other useful anionic surfactants herein include the water-soluble salts of esters of alpha-sulfonated fatty acids containing from about 6 to 20 carbon atoms in the fatty acid group and from abnut 1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxy-alkane-1-sulfonic acids containing frQm about 2 to 9 carbon atoms in the acyl group and from about 9 to about 23 carbon atoms in the ~lkane moiety; alkyl ether sulfates containing From about 10 to 20 carbon atoms in the alkyl group and from about 1 to :~322~
30 moles of ethylene oxide; water-soluble salts of olefin sulfo-nates containing from about 12 to 24 carbon ato~s; and beta-alkyloxy alkane sulfonates containing from about 1 to 3 carbon atoms in the alkyl group and from about 8 to about 20 carbon atoms in the alkane moiety.
The preferred anionic surfactant pastes are mixtures of linear or branched alkylbenzene sulfonates having an alkyl of 10-16 carbon atoms and alkyl sulfates having an alkyl of 10-18 carbon atoms. These pastes are usually produced by reacting a liquid organic material with sulfur trioxide to produce a sulfonic or sulfuric acid and then neutralizing the acid to produce a salt of that acid. The salt is the surfactant paste discussed through-out this document. The sodium salt is preferred due to end performance benefits and cost of NaOH vs. other neutralizing agents, but is not required as other agents such as KOH may be used. The neutrali~ation can be performed as part of the fine dispersion mixing step, but preneutralization of the acid in con-junction with the acid production is preferred.
Water-soluble nonionic surfat:tants are also useful as sur-factant in the compositions of thle invention. Many final deter-gent compositions include nonionics or nonionic/anionic surfactant blends. Inclusion of nonlonics in many applications is difficult, particularly if a spray-dry process is used, because of potential degradat~on and environmental concerns. A nonion1c granule can thus be admixed with a spray-dry granule to produce a preferred ~inal formulation. Such nonionic materials include compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may b~
aliphatic or alkyl aromatic în nature. The length of the poly-oxyalkylene group which is condensed with any particular hydro-phobic group can be readily adJusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.
Suitable nonionic surfactants include th~ polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl group containing from about 6 to 16 carbon atoms, in either a straight chain or branched chain con-~322~
figuratiQn, with from about 4 to 25 moles of ethylene oxide per mole of alkyl phenol.
Preferred nonionics are the water-soluble condensation products of aliphatic alcohols containing from 8 to 22 carbon atoms, in either straight chain or branched configuration, with from 4 to 25 moles of ethylene oxide per mole of alcohol. Par-ticularly preferred are the condensation products of alcohols having an alkyl group containing from about 9 to 15 carbon atoms with from about 4 to 25 moles of ethylene oxide per mole of alcohol; and condensation products of propylene glycol with ethylene oxide.
Semi-polar nonionic surfactants include water-soluble amine oxides containing one alkyl moiety of from about 10 to 18 carbon atoms and 2 moieties selected from the group consisting of alkyl groups and hydroxyalkyl groups con$aining from 1 to about 3 carbon atoms; water-soluble phosphine oxides containing one alkyl moiety of about 10 to 18 carbon atoms and 2 moieties selected from the group consisting of alkyl groups and hydroxyalkyl groups con-taining from about 1 to 3 carbon atoms; and water-soluble sul-foxides containing one alkyl moiety of from about 10 to 18 carbonatoms and a moiety selected from thle group consisting of alkyl and hydroxyalkyl moietles of from about 1 to 3 carbon atoms.
Ampholytic surfactants includle derivatives of aliphatic or aliphatic derivat~ves of heterocyclic secondary and tertiary amines in which the aliphatlc moiety can be either straight sr branched ohain and wherein one of the aliphatic substituents oontains from about 8 to 18 carbon atoms and at least one ali-phatic substituent contains an anionic water-solubilizing group.
Zwitterlonic surfactants include derivatives of aliphatic quaternary ammonium phosphonium, and sulfonium compounds in which one of the aliphatic substituents contains from about 8 to 18 carbon atoms.
The h~gh active surfactant paste formulation must be solid at about room temperature unless the granules are kept cool until mixed with other detergent solids.
The terms "LASI' and "QS" as used herein mean, respectively, "sodium lauryl benzene sulfonate" and "alkyl sulfate." The terms 13227~
like "C4s" mean C14 and Cls alkyl, unless otherwise specified.
Some of these AS and LAS surfactants do not require cooling if used at about 20-25~C.
All examples used a Cuisinart food processor, Model #DCX-Plus with 19.7 cm metal blades operating at 1800 rpm. The tip speed is 18.55 m/sec.
DeterqencY Builders The surfactant granules of thP present invention can be made with some detergency builder and/or inorganic, water-soluble salts. So, the surfactant paste can contain such materials at a ratio of salt/builder to surfactant active of from about 0:1 to about 1:1 on a dry weight basis. Any compatible detergency builder or combinatiQn of builders or water-soluble salts can be used in the process to produce desired end products or inter-mediates. However, in most cases the inclusion of such solid material is unnecessary and not desired. The present invPntion is aimed at mak~ng a purer, denser surfactant granule.
The granular detergents of the present invention can contain neutral or alkaline salts which have a pH in solution of seven or greater, and can be either organic or inorganic in nature. ~he builder salt assists in providing the desired density and bulk to the detergent granules herein. While some of the salts are inert, many of them also function as detergency builder materials in the laundering solution.
Examples of neutral water-soluble salts include the alkali metal, ammonium or substituted a~monium chorides, fluorides and sulfates. The alkali metal, and especially sodium, salts of the above ar~ preferred. Sodium sulfate is typically used in deter-gent granules and is a particularly preferred salt.
Other useful water-soluble salts include the compounds commonly known as detergent builder materials. Builders are generally selected from the various water-soluble, alkali metal, ammonium or substituted ammonium phosphates, polyphosphates, phosphonates, pnlyphosphonates, carbonates, silicates, borates, and polyhydroxysulfonates. Preferred are the alkali metal, especially sodium, salts of the above.
~ 2 ~ ~3 Specific examples of inorganic phosphate builders are sodium and potassium tripolyphosphate, pyrophosphate, polymeric meta-phosphate having a degree of polymerization of from about 6 to 21, and orthophosphate. Examples of polyphosphonate builders are the sodium and potassium salts of ethylene diphosphonic acid, the sodium and potassium salts of ethane 1-hydroxy-1,1-diphosphonic acid and the sodium and potassium salts of ethane, 1,1,2-tri-phosphonic acid. Other phosphorus builder compounds are disclosed in U.S. Pat. Nos. 3,159,581; 3,213~030; 3,422,021; 3,422,137 3,400,17S and 3,400,148.
Examples of nanphosphorus, inorganic builders are sodium and potassium carbonate, bicarbonate, sesquicarbonate, tetraborate decahydrate, and silicate having a molar ratio of SiO2 to alkali metal ox~de o~ from about 0.5 to about 4.0, preferably from about 1.0 to about 2.4. The compositions made by the process of the present invention does not require excess carbonate for process-ing, and preferably does not contain ovPr 2Xo finely divided calcium carbonate as disclosed in U.S. Pat. No. 4,196,093, Clarke et al., issued Apr. 1, 1980. and is preferably free of the latter.
It is preferred not to hydrate any hydratable builder salts in the fine dispersion mixer in the process of the present inven-tion.
her ODtionals Other ingredients commonly used in detergent compositions can be included in the compositions of the present invention to produce desired end product laundry products, but are not neces-sary, and are lncluded here to sh~w the breadth of this invention.
These include flow aids, color speckles, bleaching agents and bleach activators, suds boosters or suds suppressurs? antitarnish and anticorrosion agents, soil suspending agents, soil release agents, dyes, fillers, optical brighteners, germicldes, pH ad-justing agents, nonbuilder alkalinity sources, hydrotropes, enzymes, enzyme-stabilizing agents, chelating agents and perfumes.
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EXAMPLES
-The invention will be better understood in v;ew of the following nonlimiting examples. The percentages are on a weight basis, in the mixes prior to any subsequent follow-up drying, unless otherwise specified. The tables are followed with addi-tional processing disclosure in the numbered examples.
The terms "LAS" and "AS" as used herein mean, respectively, "sodium lauryl benzene sulfonate" and "alkyl sulfate." The terms like "C4~" mean C14 and Cls alkyl, unless otherwise specified.
Some of these AS and LAS surfactants do not require cooling if used at about 20-25C.
A Cuisinart food processor, Model #DCX-Plus with 19.7 cm metal blades operating at 1800 rpm is used for all examples. The tip speed is 18.55 m/sec.
The viscositles of LAS and AS are measured using Brookfield HAT Serial No. 74002 as follows:
For S0% and 70%, at 0.5 rpm with spindle T-A at 50C;
For 74% AS, at 0.5 rpm with spindle T-F at 50C;
For 50% AS, at 2.5 rpm with splndle T-A at 50C.
The granulation temperature for each high active surfactant paste is determined on a case by case basis.
EXAMPLF~_l An aqueous anlonic C13LAS sur1factant paste havlng a detergent activity of 70% with tha balance ~eing water, plus a small amount of unreacted and sodium sulfate salt as a reaction by-product, is mixed with dry ice in a Cuisinart food processor. The viscosity o~ the paste is about 800,000 cps 5see note below on viscosity measurement technique). The paste temperature was first about 25~C. The paste temperature drops from 25C to -50CC and sur-factant granules are formed.
The following tables summar ke several examples of the invention.
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TQBLE OF EXAMPLES (Part 1) Example Surfactant % Surf. % Unre- % % Dry No. (Yo~ActivitY~ Active acted Water Builder 1 C13LAS (70) 70 3 27 2 C13LAS (6~) 60 3 37 3 C13LAS (70) 63 3 34 lO(a) 4 C13LAS (93) 60 3 2 35(b) C13LAS/C4sAS 1:1 (70) 70 4 26 6 C4sAS (743 74 5 21 7 C4sAS (50) 50 3 47 8 C4sAS(e) (74) 68.3 4 20 9 Barlox 12(~) (8~3 87 3 10 Barlox 12~C) (87) 55 2 6 37(b) 11 Amphoterge K(d) (70) 70 3 27 TABLE OF EXAMPLES (Part 2) Granulation Example Temperature No. S~rfactant C
2 C13LAS -?0 C13LAS/C4sAS 1:1 -5 6 C4sAS 23 7 C~,5AS -5 8 C4sAS(e) -2 9 Barlox 12(~3 -60 Barlox 12(C) -40 11 Amphoterge K(d3 -52 ~a) Sodium sulfate (b) Sodium carbonate monohydrate used in Examples 4 and 10 at 35% and 37%.
:L~22rl~5 (c) Lauryl (12, 14, 16 blend) dimethyl amine oxide.
Barlox 12 is the trade mark of Lonza~ Inc.
(d) Coconut based imidazoline amphoteric, monocarboxylic.
Amphoterge K is the trademark of Lonza, Inc.
S(e) Ex. 8 is made with 7.7% mineral oil as a processing aid.
.
Example 2 is similar to Example 1, except that a 60% active (vs. 70%) C13LAS is used. The paste viscosity is about 350,000 cps. The temperature at granulation is about -20C.
EXAMP~E_~
Example 3 is simllar to Example 1, except that 10æ sodium sulfate is added to the 7~ active C13LAS. The builder salt to surfactant active ratio is 0.16. The temperature at granulation is about -35-C.
~M_LE 4 Example 4 is similar to Exam~le 3, exce~t 93X active C!3LAS
is used and 35% sodillm carbonatle monohydrate 1s added to the surfactant paste~ The paste vlscosity is >1,000,000 cps. The builder salt to surfactant active ratio is 0.54, The temperature at granulation is about 4'C.
~M~lE 5 Example 5 is simllar to xample 1, except a 1:1 blend of ~ C13LAS and C~sAS is used. Both pastes have an activity level of 7Q%. Th~ viscosity of the C4sLAS is >7,000,~00 cps. The tem-perature at granulation is about -5^C.
~L~
Best MQde: Example 6 is similar to Example 1, except 74~O
active C4sAS (vs. 70YO active C13LAS) is usedO The viscosity of the paste is >790009Q00 cps. The temperature at granula~ion is ab~ut 23'C.
The yield of the~e granules in the 200-2,000 micron particle slze range is about 42%. The granules are set under ambient 1~227~
conditions and placed back in the mixer and mixed for about 15 seconds. The final yield is about 85%; moisture is about 14%.
EXAMPLE ?
Example 7 is similar to Example 6, except 50% active (vs.
74%) C4sAS is used. The viscosity of the paste is 25,000 cps.
The temperature at granulation is about -5C.
Example 8 is similar to Example 6, except 7.7% mineral oil is added as a processing aid. The temperature at granulation is about -2C.
Example 9 is similar to Example 19 except 87% active Barlox 12 (C12 16 dimethyl amine oxide) is used instead of 70% C13LAS.
The viscosity of the paste is about 1,000,000 cps. The tem-perature at granulation is about -60C.
EXAMPL~. 10 Example 10 is similar to Example 9, except 37% sodium car-bonate monohydrate is added to the 87% active Barlox 12. The bu-ilder salt to surfactant active ratio -is 0.65. The temperature at granulation -is about -40C.
Examp1e 11 is similar to Example 1, except 70% Amphoterge K
is used instead of 70% C13LAS. The viscosity of the paste is about 500,000 cps. The temperature at granulation is about -52C.
In the above examples dense, concentrated, highly active surfactant granules are successfully made using the process of the present invention.
PROCESS FOR MAKING CONCENTRATED SURFACTANT GRANULES
Daniel L. Strauss Charles L. Stearns Thomas E. Lobaugh FIELD OF INVENTION
The present invention relates to a process for preparing concentrated ~condensed) surfactant granules.
BACKGROUND OF THE INVENTION
Granular surfactant compositions are principally prepared by spray or drum drying. In the spray drying process the surfactant components, plus perhaps salts and builders, are mixed with as much as 35-50% waker to form a slurry. The slurry obtained is heated and spray dried9 which is expensive~
Such spray drying requires 30-40 wt.% of the water to be removed. The spray drying equipment used is expensive. The granule obtained has good solubility but a low bulk density, so the packing volume is large. Th~ particles also may be sticky, particularly when hot, and thus wall buildup is an additional problem. There are other known disadYantages in preparing gran-ular materials by spray drying, such as environmental concerns and heat sensitivity. An agglomeration process, on the other hand, would be cleaner, as well as less expensive, both in terms of equipment and operat~ng costs.
Ther~ are many prior art nonspray-drying processes which produce surfactant granule~. Most, howaver, require mixing of the surfactant with other materials such as inorganic salts or alumi-nosilicate-type materials. Some other processes require use of an acid form of the surfactan~ to work. In most cases, a diluted surfac~ant particle is obtalned. The major problem with the use of a high active surfaotant paste as a starting material in a one step granulation process is its stickiness.
In U.S. Pat. No. 4,515,707, Brooks, issued May 7, 1985;
Japanese laid-open Appln. No. 183540/19B3, Kao Soap Co., Ltd., filed S@pt. 30, 1983; and Japanese Sho. 61-118500, Lion K.K., 227 ~ ~
June 5, 1986, high shear and/or cold mixing processes are dis-closed. Typically, excess carbonate is required (2-10 molar excess) to assure reasonable conversion of the surfactant acids.
Excess carbonate adversely drives up the wash water pH to the very alkaline range which can be undesirable, particularly for some nil-phosphate formulas and formulas containing peracid bleaches.
Such high shear and cold mixing processes are known, but they have drawbacks, e.g., some require an extra grinding step or some other action, as well as the addition of other ingredients, primarily solids. Others use a dry neutrali~ation technique for mixing the acid form of the surfactant with sodium carbonate.
A practlcal problem with the use of a surfactant acid form is that it requires immediate use after it is made, or cool tempera-ture storage, for such highly reactiYe acids, such as the alkyl sulfate acids9 are subject to degradation unless cooled. They also tend to undergo hydrolysis during storage, forming free sulfurie acid and alcohol. In practical terms, such prior art processes require close coupling of surfactant acid production with granulation which requires an additional capital investment.
~n U.S. Pat. No. 4,162,994, Ko~alchuk, issued July 31, 1~7~, it is disclosed that calcium salts are re~uired to overcome problems in process~ng by nonspray drying (i.e.~ mechanical) means ~ormulations based on sodium salts of anionic surfactants and certain nonionic surfactants. A drawback to that process is that insoluble calc~um salts can lower the solubility of the formu-lation, which is of particular importance in stress situations, such as in pouch-type executions.
U.S. Pat. No. 4,427,417, Porasik, issued Jan. 24, 1~84, discloses preparing granular detergent composit;ons from hydrat-~o abl e particul ate detergent salts, etc., under conditlons insuring complete hydration and agglomerating them into storage stable, dry, pourabl e agglomerates.
SUMMARY OF THE INV~NTION
The present invention relates to an economical process for making a dense, concentrated surfactant granule from a high active surfactant paste using fine dispersion cold granulation.
A
~ 3 2 ,~ r~
- OBJECTS OF THE_INVENTION
An important object of the present invention is to make a denser and more concentrated surfactant granular product by an agglomeration process without an expensive drying step. Another object is to provide a more concentrated surfactant granule which can be stored and then admixed with other ingredients to provide a final end product. Another object of the process of this inven-tion is to provide a formulated granule containing higher total surfactant levels than typically obtained via other means. Yet another object of the present invention is to prepare a very high active surfactant granule essential free of hydrated inorganic salts. Other objects of the present invention will be apparent in view of the following.
DETAILED DESCRIPTION OF THE INVENTIQN
The process of the present invention comprises fine dis-persion mixing and cooling o~ a high active surfactant paste to provide a very concentrated surfactant granllle. Most high active surfactant pastes are too tacky at normal m;xing temperatures to successfully granulate using fine dispersion mixing. So the high active surfactant paste is cooled as needed to a granulation tem-perature while mixing. Iarge discrete particles (granules) are surprisingly formed right in the mixer. Thus "cold" granulation of a hlgh surfactant past is achleved.
The granulation temperature, according to the present inven-tion9 ranges from about -65-C to 25C using a critical fine dispersion mixing tip speed of from about 5 m/sec. to about 50 m/sec. Dry ice is a preferred cooling means.
A benefit of the present invention is that the preferred 30 granules made according to the present invention are large, essentially pure surfactant granules. They preferably have a bulk density of from about 0.4 to about 1.1 9/CC9 more preferably from about 0.5 to about 0.8 g/cc. The weight aYerage particle size of the preferred particles of th~s invention are from about 200 to about 2,000 mkrons. The more preferred granules have a particle size range of from 300 to 1,200 microns. Yields of 25% to &5% in these ranges can be achie~ed. A second brief mixins increases ~3~27~
y;e!ds of granular particles in these preferred ranges. Oversized and undersized particles can also be recycled.
The more preferred granulation temperatures of the high active surfactant paste ranges from about -40C to about 10C, and most preferably from about -30C to about 0C. More details of the present invention are highlighted below.
The resultant surfactant granules made by the process of the present invention can comprise a combination of all, or substan-tially all, of the ingredients Qf the total composition or th~y can be used as an intermediate. Thus, such granules greatly reduce or even eliminate tha need to admix additional materials for a final detergent formulation. Also, the possibility of segregation of ingredients during shipping, handling or storage is greatly reduced, especially if only minor quantities of other materials of differing particle si~es or densities are to be included.
Separately, the concentrated granule of this invention can be admixed with detergent granules produced by more conventional means to increase the total surfactant level in a final formu-lation.
Methods of CoolinqLthe Hlq~!-Active Surfactant Paste Any suitab1e method of coollng the high active surfactant paste to a granulation temperature can be used. Cooling jackets or coils can be integrated around or into the mixer. Chipped dry ice or liquid CO~ can be added or ~njected into the uniform paste.
The idea is to lower the high active surfactant paste temparature to a granulation temperature so that it can be finely dispersed or "granulated" into discrete particles.
_ste Viscositv and Processinq Two important parameters of the high active surfactant pastes which can affect the parameters of ~he mixing and granulation step of the present invention are the paste temperature and the paste viscosity. The viscosity is a function of surfactant concen-tration and its temperature. The high active surfactants of the present invention have viscosities which range from about 10,000 cps to 10,000,000 cps; preferably, from about 70,000 to about - - -~2~7~
7,000,000 cps; and more preferably from about 100,000 to about 1,000,000 cps. These viscosities are measured at a temperature of about 50'C for the present invention.
The high active surfactant paste can be introduced into the mixer at an initial temperature in the range of about 5-70C, preferably about 2U-30C. Higher temperatures reduce their viscosities but a temperature greater than about 70C can lead to poor initial mixing due to increased product stickiness.
The process of the present invention surprisingly forms large, but usable~ granules, preferably in the 200 to 1200 micron range. Such large granules are preferred, particularly if the surfactant granule is to be admixed with other materials which have a tendency to be dusty. Particles of similar size are preferred to minimize segregation. No extra grinding step is required or desirable. In general, larger particles are less dusty, which is important in many consumer applications, especi-ally those which comprise porous, unitized dose pouch-like products. Such porous products are designed: ~1) to avoid con-sumer contact with the product ilnd (2) to reinforce the con-venience and nonmessiness perceptions of a unit ked pouch form.
- If desired, granules of insufficilent size can be screened after drying and recycled to the fine di<;persion mixer.
The Fine Pisper$lQ~ ~ting and Gran~Jation Unless otherwise specified, the terms "fine dispersion mixing" and/or` "granulation," as used herein are synonymous and mean mixing and granulating of a htgh active surfactant paste in a fine dispersion mixer using a blade tip speed of from about 5 m/sec. to about 50 m/se. The total residence time of the mixing and granulatlon process is preferably in the order of from 0.1 to 10 m1nutes, more pre~erably 0.5-8 and most preferably 1-6 minutes.
The more preferred mixing and granulation tip speeds are about 10-40 m/sec. and about 15-35 m/sec.
The Little~ord Mixer, Model #FM-130-D-12, with internal chopping blades and the Cuisinart~ Faod Processor, Model #DCX-Plus, with 7.75 inch (19.7 c-) blades are two examples of suitable mixers. Any other mixer with fine dispersion mixing and granu-lation capability and which preferably has a residence time in the 132~7~
order of 0.1 to 10 minutes can be used. The i'turbine type"
impeller mixer, having several blades on an axis of rotation, is preferred. The invention can be practiced as a batch or a con-tinuous process.
The mixer must finely disperse the paste and, if desired, the other ingredients. When the contents of the mixer are cooled, the mixing ~ust be conducted at said fine dispersion tip speed in order to granulate the surfactant into discrete particles. Care must be taken not to use too low or too high of a tip speed at the granulation step. While not being bound to a theory, ~Itoo high a shear" is believed to prevent granulation because of a wide variety of str~sses, e.g., a broader particle size distribution caused by the high~r tlp speeds with a higher level of fines generated. Also, too high of a tip speed increases the tempera-ture of the material and additional cooling is required.
Care must be taken not to overload any fine dispersion mixer with two much or too little surfactant paste material. If there is more than one material the results ara poor mixing and unsat-isfactory granulation. Thus, care must be taken to load the mixer with a proper level of paste material so that satisfactory mixing and granulation are achieved. Sim~lar to too low of a tip speed, overloading the mixer results in poor dispersion, reduced uni-formity and large lumps. On the other hand, too high of a tip speed increases the production of undesirable fines.
The work input required for fine d;spersion mixing in the practice of the present invention varies with: (1) the type of fine dispersion mixer used, (2) the mixer loading level, (3) the viscosity of the paste material, and ~4) the amount and the type of dry solids used~ if any. E.g., the Total Work required for mixing and granulation of several preferred paste materials using a laboratory Cuisinart food processor, Model ~DCX-Plus varied from about 7 BTU's to about 16 BTU's per pound of paste material. The rorresponding I~crem~ntal Work varied from about 0.4 BTU's to about 2.6 BTU's per pound of paste material. Tha No Load Work for the Cuisinart food processor ~s about 0.2 BTU's per second. The Cuisinart food processor has a single 19.7 cm flat horizontal ~227~
propeller and is operated at 1800 rpm, which is a tip speed of about 1~.55 m/sec.
The Total Work required to mix and granulate the surfactant paste of the present invention can vary from about 3 BTU's to about 30 BTU's per pound of material depending on viscosity, load, etc. A preferred range is from about S BTU's to about 20 BTU's per pound. These BTU ranges in kilogram of material are, respec-tively, from about 6.6 to 66, and from about 11 to 44 BTU/Kg.
Some benefits of fine dispersion mixing and granulation include: (1) a lower level of granulated fines; (2) a more uniform granular particle size distribution; an~ (3) a hlgher density granule than a granular product made with standard agglomeration-type mixers, such as pan type mixers.
Hiqh Active Surfactant Paste The activity of the aqueous surfactant paste is at least 50%
and can go up to about 98%; preferred activities are: 60-80% and 65-75%. The balance of the paste is primarily water but can include a processing aid such as mineral oil. The resultant con-centrated surfactant granules can be added to dry detergencybuilders or conventionally agglomerated with blnders with these builders or other materials to yield desired finlshed formula compositions.
In the process of the present invention, it is preferable to use higher active surfactant pastes to minlmize the total water level in the system during mixing and granulating~ The benefits of lower water levels are to allow for (1) higher levels of other liquids in the formula without causing stickiness; (2) less cooling, du~ to higher granulation temperatures; and (3) less granular drying to meet final moisture limits.
Tt is important that the mo~stur2 or solvent (hereinafter referred to as "molsture") content of the high activ~ surfactant should not exceed 50%. The total moisture can range from about 2%
to about 50%, but is preferably from about 10% to about 40%, and more preferably from about 15Yo to about 30%. The lower granu-lation temperatures are used for the higher mois~ure-containing ~L322~
pastes. Conversely, the higher granulation temperatures can be used for lower moisture pastes.
Paste compositions which have lower moisture contents of below 5X~ e.g., about 1% to 4,~, can contain an effective amount of an organic liquid solvent or processing aid. Examples of such aids are selected from suitable organic liquid, including ~ineral oil, glycerin, short chain alcohols, and the like, and mixtures thereof. The processing aid preferably can be used at a level of "0.5% to 20~," more preferably about 1-lOYo; most preferably about 2-579 by weight of the paste.
The desired moisture content of the surfactant granules of this inYention can be adjusted by adding other deslred dry ingre-dients prior to cooling and granulation. Thus, additional "drying" is unnecessary in low moisture formulations. ~hen desirable, drying the discrete granules can be accomplished in a standard fluid bed dryer. Tha idea here is to provide a free flowing granule with a desired moisture content of 0.5-10%, preferably 1-5%.
lhe aqueous surfactant paste contains an organic surfactant selected from the group consisiting of anionic, zwitterionic, ampholytic, nonionic and cationic surfactants, and mixtures thereof. Anionic surfactants are preferred. Surfactants useful herein are listed ln U.S. Pat. No. 3,664,961, Norris, issued May 23, 1972, and in U.S. Pat. No. ~919,678, Laughlin et al., issued Dec. 30, 1975.
Useful cationic surfactants also include those described in U.S.
: Pat. ~o. 4,222,905, Cockrell, issued Sept. 16, 19~0, and in U.S.
Pat . No . 4, 2~9, 659, Murphy, i ssued Dec ~ 16, 1980 ~
The following are representative ~0 examples of surfactants useful in the present compositions.
~ater-soluble salts of the higher fatty acids, i.e., "soaps,"
are useful anionic surfactants in ~he compositions herein. This includ~s alkali metal soaps such as the sodium, potassium, ammo-nium, and alkylolammonium salts of higher fatty acids containing from about 8 to about 24 carbon atoms, and preferably from about 12 to about 18 carbon atoms~ Soaps can be made by direct saponi-ficatio~ of fats and oils or by the neutralization of frse fatty acids. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, ..
.. ..
~t~
, . .
~ 322~
g i.e., sodium or potassium tallo~ and coconut soap.
Useful anionic surfactants also include the water-soluble salts, preferably the alkali metal, ammonium and alkylolammonium salts, of organic sulfuric reaction products having in their molecular structure an alkyl group containing from about 10 to about 20 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 are the sodium and potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (Cg-C1g carbon atoms) such as those produced by reducing the glycerides of tallow or coconut oil; and the sodium and potassium alkyl benzene sulfonates in which the alk~l group contains from about 9 to about 15 carbon atoms, in straight or branched chain configuration, e.g., those of the type described in U.S. Pat. Nos. 2,220,09g and 2,477,383. ~specially valuable are linear straight ~hain alkyl benzene sulfonates in which the average number of carbon atoms in the alkyl yroup is from about 11 to 13, abbreviated ax Cll-C13 LAS.
Other anionic surfactants herein are the sodium alkyl glyc-eryl ether sulfonates, espectally 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 alkyl phenol ethylene oxlde cther sulfates containing from about 1 to about 10 units of ethylene oxide per molecule and wherein the alkyl groups contain from about 8 to about 12 carbon atoms; and sodium or potassium salts of alkyl ethylene oxide ether sulfates cont~ining from about 1 to about 10 units of ethylene oxide per molecule and wherein the alkyl group contains from about 10 to about 20 carbon atoms.
Other useful anionic surfactants herein include the water-soluble salts of esters of alpha-sulfonated fatty acids containing from about 6 to 20 carbon atoms in the fatty acid group and from abnut 1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxy-alkane-1-sulfonic acids containing frQm about 2 to 9 carbon atoms in the acyl group and from about 9 to about 23 carbon atoms in the ~lkane moiety; alkyl ether sulfates containing From about 10 to 20 carbon atoms in the alkyl group and from about 1 to :~322~
30 moles of ethylene oxide; water-soluble salts of olefin sulfo-nates containing from about 12 to 24 carbon ato~s; and beta-alkyloxy alkane sulfonates containing from about 1 to 3 carbon atoms in the alkyl group and from about 8 to about 20 carbon atoms in the alkane moiety.
The preferred anionic surfactant pastes are mixtures of linear or branched alkylbenzene sulfonates having an alkyl of 10-16 carbon atoms and alkyl sulfates having an alkyl of 10-18 carbon atoms. These pastes are usually produced by reacting a liquid organic material with sulfur trioxide to produce a sulfonic or sulfuric acid and then neutralizing the acid to produce a salt of that acid. The salt is the surfactant paste discussed through-out this document. The sodium salt is preferred due to end performance benefits and cost of NaOH vs. other neutralizing agents, but is not required as other agents such as KOH may be used. The neutrali~ation can be performed as part of the fine dispersion mixing step, but preneutralization of the acid in con-junction with the acid production is preferred.
Water-soluble nonionic surfat:tants are also useful as sur-factant in the compositions of thle invention. Many final deter-gent compositions include nonionics or nonionic/anionic surfactant blends. Inclusion of nonlonics in many applications is difficult, particularly if a spray-dry process is used, because of potential degradat~on and environmental concerns. A nonion1c granule can thus be admixed with a spray-dry granule to produce a preferred ~inal formulation. Such nonionic materials include compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may b~
aliphatic or alkyl aromatic în nature. The length of the poly-oxyalkylene group which is condensed with any particular hydro-phobic group can be readily adJusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.
Suitable nonionic surfactants include th~ polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl group containing from about 6 to 16 carbon atoms, in either a straight chain or branched chain con-~322~
figuratiQn, with from about 4 to 25 moles of ethylene oxide per mole of alkyl phenol.
Preferred nonionics are the water-soluble condensation products of aliphatic alcohols containing from 8 to 22 carbon atoms, in either straight chain or branched configuration, with from 4 to 25 moles of ethylene oxide per mole of alcohol. Par-ticularly preferred are the condensation products of alcohols having an alkyl group containing from about 9 to 15 carbon atoms with from about 4 to 25 moles of ethylene oxide per mole of alcohol; and condensation products of propylene glycol with ethylene oxide.
Semi-polar nonionic surfactants include water-soluble amine oxides containing one alkyl moiety of from about 10 to 18 carbon atoms and 2 moieties selected from the group consisting of alkyl groups and hydroxyalkyl groups con$aining from 1 to about 3 carbon atoms; water-soluble phosphine oxides containing one alkyl moiety of about 10 to 18 carbon atoms and 2 moieties selected from the group consisting of alkyl groups and hydroxyalkyl groups con-taining from about 1 to 3 carbon atoms; and water-soluble sul-foxides containing one alkyl moiety of from about 10 to 18 carbonatoms and a moiety selected from thle group consisting of alkyl and hydroxyalkyl moietles of from about 1 to 3 carbon atoms.
Ampholytic surfactants includle derivatives of aliphatic or aliphatic derivat~ves of heterocyclic secondary and tertiary amines in which the aliphatlc moiety can be either straight sr branched ohain and wherein one of the aliphatic substituents oontains from about 8 to 18 carbon atoms and at least one ali-phatic substituent contains an anionic water-solubilizing group.
Zwitterlonic surfactants include derivatives of aliphatic quaternary ammonium phosphonium, and sulfonium compounds in which one of the aliphatic substituents contains from about 8 to 18 carbon atoms.
The h~gh active surfactant paste formulation must be solid at about room temperature unless the granules are kept cool until mixed with other detergent solids.
The terms "LASI' and "QS" as used herein mean, respectively, "sodium lauryl benzene sulfonate" and "alkyl sulfate." The terms 13227~
like "C4s" mean C14 and Cls alkyl, unless otherwise specified.
Some of these AS and LAS surfactants do not require cooling if used at about 20-25~C.
All examples used a Cuisinart food processor, Model #DCX-Plus with 19.7 cm metal blades operating at 1800 rpm. The tip speed is 18.55 m/sec.
DeterqencY Builders The surfactant granules of thP present invention can be made with some detergency builder and/or inorganic, water-soluble salts. So, the surfactant paste can contain such materials at a ratio of salt/builder to surfactant active of from about 0:1 to about 1:1 on a dry weight basis. Any compatible detergency builder or combinatiQn of builders or water-soluble salts can be used in the process to produce desired end products or inter-mediates. However, in most cases the inclusion of such solid material is unnecessary and not desired. The present invPntion is aimed at mak~ng a purer, denser surfactant granule.
The granular detergents of the present invention can contain neutral or alkaline salts which have a pH in solution of seven or greater, and can be either organic or inorganic in nature. ~he builder salt assists in providing the desired density and bulk to the detergent granules herein. While some of the salts are inert, many of them also function as detergency builder materials in the laundering solution.
Examples of neutral water-soluble salts include the alkali metal, ammonium or substituted a~monium chorides, fluorides and sulfates. The alkali metal, and especially sodium, salts of the above ar~ preferred. Sodium sulfate is typically used in deter-gent granules and is a particularly preferred salt.
Other useful water-soluble salts include the compounds commonly known as detergent builder materials. Builders are generally selected from the various water-soluble, alkali metal, ammonium or substituted ammonium phosphates, polyphosphates, phosphonates, pnlyphosphonates, carbonates, silicates, borates, and polyhydroxysulfonates. Preferred are the alkali metal, especially sodium, salts of the above.
~ 2 ~ ~3 Specific examples of inorganic phosphate builders are sodium and potassium tripolyphosphate, pyrophosphate, polymeric meta-phosphate having a degree of polymerization of from about 6 to 21, and orthophosphate. Examples of polyphosphonate builders are the sodium and potassium salts of ethylene diphosphonic acid, the sodium and potassium salts of ethane 1-hydroxy-1,1-diphosphonic acid and the sodium and potassium salts of ethane, 1,1,2-tri-phosphonic acid. Other phosphorus builder compounds are disclosed in U.S. Pat. Nos. 3,159,581; 3,213~030; 3,422,021; 3,422,137 3,400,17S and 3,400,148.
Examples of nanphosphorus, inorganic builders are sodium and potassium carbonate, bicarbonate, sesquicarbonate, tetraborate decahydrate, and silicate having a molar ratio of SiO2 to alkali metal ox~de o~ from about 0.5 to about 4.0, preferably from about 1.0 to about 2.4. The compositions made by the process of the present invention does not require excess carbonate for process-ing, and preferably does not contain ovPr 2Xo finely divided calcium carbonate as disclosed in U.S. Pat. No. 4,196,093, Clarke et al., issued Apr. 1, 1980. and is preferably free of the latter.
It is preferred not to hydrate any hydratable builder salts in the fine dispersion mixer in the process of the present inven-tion.
her ODtionals Other ingredients commonly used in detergent compositions can be included in the compositions of the present invention to produce desired end product laundry products, but are not neces-sary, and are lncluded here to sh~w the breadth of this invention.
These include flow aids, color speckles, bleaching agents and bleach activators, suds boosters or suds suppressurs? antitarnish and anticorrosion agents, soil suspending agents, soil release agents, dyes, fillers, optical brighteners, germicldes, pH ad-justing agents, nonbuilder alkalinity sources, hydrotropes, enzymes, enzyme-stabilizing agents, chelating agents and perfumes.
~322~ ~
EXAMPLES
-The invention will be better understood in v;ew of the following nonlimiting examples. The percentages are on a weight basis, in the mixes prior to any subsequent follow-up drying, unless otherwise specified. The tables are followed with addi-tional processing disclosure in the numbered examples.
The terms "LAS" and "AS" as used herein mean, respectively, "sodium lauryl benzene sulfonate" and "alkyl sulfate." The terms like "C4~" mean C14 and Cls alkyl, unless otherwise specified.
Some of these AS and LAS surfactants do not require cooling if used at about 20-25C.
A Cuisinart food processor, Model #DCX-Plus with 19.7 cm metal blades operating at 1800 rpm is used for all examples. The tip speed is 18.55 m/sec.
The viscositles of LAS and AS are measured using Brookfield HAT Serial No. 74002 as follows:
For S0% and 70%, at 0.5 rpm with spindle T-A at 50C;
For 74% AS, at 0.5 rpm with spindle T-F at 50C;
For 50% AS, at 2.5 rpm with splndle T-A at 50C.
The granulation temperature for each high active surfactant paste is determined on a case by case basis.
EXAMPLF~_l An aqueous anlonic C13LAS sur1factant paste havlng a detergent activity of 70% with tha balance ~eing water, plus a small amount of unreacted and sodium sulfate salt as a reaction by-product, is mixed with dry ice in a Cuisinart food processor. The viscosity o~ the paste is about 800,000 cps 5see note below on viscosity measurement technique). The paste temperature was first about 25~C. The paste temperature drops from 25C to -50CC and sur-factant granules are formed.
The following tables summar ke several examples of the invention.
~ ~2~'7~
TQBLE OF EXAMPLES (Part 1) Example Surfactant % Surf. % Unre- % % Dry No. (Yo~ActivitY~ Active acted Water Builder 1 C13LAS (70) 70 3 27 2 C13LAS (6~) 60 3 37 3 C13LAS (70) 63 3 34 lO(a) 4 C13LAS (93) 60 3 2 35(b) C13LAS/C4sAS 1:1 (70) 70 4 26 6 C4sAS (743 74 5 21 7 C4sAS (50) 50 3 47 8 C4sAS(e) (74) 68.3 4 20 9 Barlox 12(~) (8~3 87 3 10 Barlox 12~C) (87) 55 2 6 37(b) 11 Amphoterge K(d) (70) 70 3 27 TABLE OF EXAMPLES (Part 2) Granulation Example Temperature No. S~rfactant C
2 C13LAS -?0 C13LAS/C4sAS 1:1 -5 6 C4sAS 23 7 C~,5AS -5 8 C4sAS(e) -2 9 Barlox 12(~3 -60 Barlox 12(C) -40 11 Amphoterge K(d3 -52 ~a) Sodium sulfate (b) Sodium carbonate monohydrate used in Examples 4 and 10 at 35% and 37%.
:L~22rl~5 (c) Lauryl (12, 14, 16 blend) dimethyl amine oxide.
Barlox 12 is the trade mark of Lonza~ Inc.
(d) Coconut based imidazoline amphoteric, monocarboxylic.
Amphoterge K is the trademark of Lonza, Inc.
S(e) Ex. 8 is made with 7.7% mineral oil as a processing aid.
.
Example 2 is similar to Example 1, except that a 60% active (vs. 70%) C13LAS is used. The paste viscosity is about 350,000 cps. The temperature at granulation is about -20C.
EXAMP~E_~
Example 3 is simllar to Example 1, except that 10æ sodium sulfate is added to the 7~ active C13LAS. The builder salt to surfactant active ratio is 0.16. The temperature at granulation is about -35-C.
~M_LE 4 Example 4 is similar to Exam~le 3, exce~t 93X active C!3LAS
is used and 35% sodillm carbonatle monohydrate 1s added to the surfactant paste~ The paste vlscosity is >1,000,000 cps. The builder salt to surfactant active ratio is 0.54, The temperature at granulation is about 4'C.
~M~lE 5 Example 5 is simllar to xample 1, except a 1:1 blend of ~ C13LAS and C~sAS is used. Both pastes have an activity level of 7Q%. Th~ viscosity of the C4sLAS is >7,000,~00 cps. The tem-perature at granulation is about -5^C.
~L~
Best MQde: Example 6 is similar to Example 1, except 74~O
active C4sAS (vs. 70YO active C13LAS) is usedO The viscosity of the paste is >790009Q00 cps. The temperature at granula~ion is ab~ut 23'C.
The yield of the~e granules in the 200-2,000 micron particle slze range is about 42%. The granules are set under ambient 1~227~
conditions and placed back in the mixer and mixed for about 15 seconds. The final yield is about 85%; moisture is about 14%.
EXAMPLE ?
Example 7 is similar to Example 6, except 50% active (vs.
74%) C4sAS is used. The viscosity of the paste is 25,000 cps.
The temperature at granulation is about -5C.
Example 8 is similar to Example 6, except 7.7% mineral oil is added as a processing aid. The temperature at granulation is about -2C.
Example 9 is similar to Example 19 except 87% active Barlox 12 (C12 16 dimethyl amine oxide) is used instead of 70% C13LAS.
The viscosity of the paste is about 1,000,000 cps. The tem-perature at granulation is about -60C.
EXAMPL~. 10 Example 10 is similar to Example 9, except 37% sodium car-bonate monohydrate is added to the 87% active Barlox 12. The bu-ilder salt to surfactant active ratio -is 0.65. The temperature at granulation -is about -40C.
Examp1e 11 is similar to Example 1, except 70% Amphoterge K
is used instead of 70% C13LAS. The viscosity of the paste is about 500,000 cps. The temperature at granulation is about -52C.
In the above examples dense, concentrated, highly active surfactant granules are successfully made using the process of the present invention.
Claims (10)
1. A process for making condensed surfactant granules comprising the steps of:
A. cooling a surfactant paste having a surfactant active level of at least 50% 9 to a granulation temperature of from about -65°C to about 25°C;
B. granulating said cooled paste into discrete detergent granules using fine dispersion mixing at a tip speed of about 5-50 m/sec; and wherein said surfactant is selected from the group consisting of anionic, zwitterionic, ampholytic, nonionic and cationic surfactants and mixtures thereof; and wherein said mixing and granulating are conducted with a mixer residence time offrom about 0.1 to about 10 minutes.
A. cooling a surfactant paste having a surfactant active level of at least 50% 9 to a granulation temperature of from about -65°C to about 25°C;
B. granulating said cooled paste into discrete detergent granules using fine dispersion mixing at a tip speed of about 5-50 m/sec; and wherein said surfactant is selected from the group consisting of anionic, zwitterionic, ampholytic, nonionic and cationic surfactants and mixtures thereof; and wherein said mixing and granulating are conducted with a mixer residence time offrom about 0.1 to about 10 minutes.
2. A process according to Claim 1 wherein said surfactant paste has a surfactant active level up to about 98%; and wherein said paste has a viscosity of from 10,000 to about 10,000,000 cps at about 50°C; and wherein said surfactant paste of Step A has a temperature of from about 5°C to about 70°C.
3. A process according to Claim 2 wherein said condensed surfactant granules have a surfactant active level of at least 50%.
4. A process according to Claim 1 wherein said granulation temperature of saidpaste is about -40°C to about 10°C.
5. A process according to Claim 1 wherein said tip speed is 10-40 m/sec and said residence time is 0.5-8 minutes.
6. A process according to Claim 1 wherein said paste has a surfactant active level of 60-80%; and wherein said paste has a viscosity of from about 70,000 to about 7,000,000 cps; said paste is used at an initial temperature of 20-30°C, and wherein said granulation temperature is about -30°C to about 0°C and wherein said discrete surfactant granules formed from said paste have an average particle size of from about 200 microns to about 2,000 microns and wherein said dried granules have a bulk density of from about 0.4 to about 1.1 g/cc.
7. The process according to Claim 1 wherein the said surfactant active level of said paste is about 65-75%; and wherein the density of said granules is from about 0.5 to about 0.7 g/cc.
8. The process according to Claim 1 wherein said surfactant paste contains a material selected from inorganic salts or builders and mixtures thereof having aweight ratio of said material to surfactant active of from about 0:1 to about 1:1.
9. A process according to Claim 1 wherein the moisture in said discrete granules is reduced by drying in a fluid bed dryer to a moisture content of 1-8%.
10. A product made by the process of Claim 1.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/213,575 US4925585A (en) | 1988-06-29 | 1988-06-29 | Detergent granules from cold dough using fine dispersion granulation |
| US213,575 | 1988-06-29 | ||
| US07/288,759 US5080848A (en) | 1988-12-22 | 1988-12-22 | Process for making concentrated surfactant granules |
| US288,759 | 1988-12-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1322705C true CA1322705C (en) | 1993-10-05 |
Family
ID=26908207
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000604216A Expired - Fee Related CA1322705C (en) | 1988-06-29 | 1989-06-28 | Process for making concentrated surfactant granules |
Country Status (13)
| Country | Link |
|---|---|
| EP (1) | EP0349200B1 (en) |
| JP (1) | JP2845953B2 (en) |
| AR (1) | AR245773A1 (en) |
| AU (1) | AU624155B2 (en) |
| BR (1) | BR8903195A (en) |
| CA (1) | CA1322705C (en) |
| DE (1) | DE68924373T2 (en) |
| DK (1) | DK323989A (en) |
| ES (1) | ES2076963T3 (en) |
| IE (1) | IE892100L (en) |
| MX (1) | MX165307B (en) |
| NZ (1) | NZ229756A (en) |
| TR (1) | TR24383A (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4925585A (en) * | 1988-06-29 | 1990-05-15 | The Procter & Gamble Company | Detergent granules from cold dough using fine dispersion granulation |
| US5045238A (en) * | 1989-06-09 | 1991-09-03 | The Procter & Gamble Company | High active detergent particles which are dispersible in cold water |
| CA2017921C (en) * | 1989-06-09 | 1995-05-16 | John Michael Jolicoeur | Formation of detergent granules by deagglomeration of detergent dough |
| KR0170424B1 (en) * | 1990-07-05 | 1999-01-15 | 호르스트 헤를레,요한 글라슬 | Process for making washing and cleaning active tensile granulates |
| US5494599A (en) * | 1991-04-12 | 1996-02-27 | The Procter & Gamble Company | Agglomeration of high active pastes to form surfactant granules useful in detergent compositions |
| EP0560001B1 (en) * | 1992-03-10 | 1999-05-19 | The Procter & Gamble Company | High active detergent pastes |
| US5486303A (en) * | 1993-08-27 | 1996-01-23 | The Procter & Gamble Company | Process for making high density detergent agglomerates using an anhydrous powder additive |
| US6058623A (en) * | 1993-09-24 | 2000-05-09 | The Chemithon Corporation | Apparatus and process for removing volatile components from a composition |
| US5723433A (en) * | 1993-09-24 | 1998-03-03 | The Chemithon Corporation | Sovent removal process |
| CZ284830B6 (en) * | 1993-11-24 | 1999-03-17 | Unilever Nv | Detergent in the form of particles and process for producing thereof |
| FR2721616A1 (en) | 1994-06-22 | 1995-12-29 | Hoechst France | Compositions of anionic surfactants in powder, pearls or granules, process for their preparation and their use in cleaning and maintenance products |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4115308A (en) * | 1976-12-27 | 1978-09-19 | The Procter & Gamble Company | High-shear process for preparing silicate-containing paste-form detergent compositions |
| IN160448B (en) * | 1982-12-07 | 1987-07-11 | Albright & Wilson | |
| JPS6072998A (en) * | 1983-09-30 | 1985-04-25 | 花王株式会社 | Manufacture of surfactant powder composition with high powder properties |
| GB8505062D0 (en) * | 1985-02-27 | 1985-03-27 | Unilever Plc | Processing granulated solids |
| CA1275019A (en) * | 1985-10-09 | 1990-10-09 | The Procter & Gamble Company | Granular detergent compositions having improved solubility |
| US4925585A (en) * | 1988-06-29 | 1990-05-15 | The Procter & Gamble Company | Detergent granules from cold dough using fine dispersion granulation |
-
1989
- 1989-06-23 ES ES89306335T patent/ES2076963T3/en not_active Expired - Lifetime
- 1989-06-23 DE DE1989624373 patent/DE68924373T2/en not_active Expired - Fee Related
- 1989-06-23 EP EP89306335A patent/EP0349200B1/en not_active Expired - Lifetime
- 1989-06-28 NZ NZ22975689A patent/NZ229756A/en unknown
- 1989-06-28 TR TR51789A patent/TR24383A/en unknown
- 1989-06-28 CA CA000604216A patent/CA1322705C/en not_active Expired - Fee Related
- 1989-06-28 AU AU37135/89A patent/AU624155B2/en not_active Ceased
- 1989-06-28 IE IE210089A patent/IE892100L/en unknown
- 1989-06-29 JP JP1168233A patent/JP2845953B2/en not_active Expired - Lifetime
- 1989-06-29 DK DK323989A patent/DK323989A/en not_active Application Discontinuation
- 1989-06-29 MX MX1665589A patent/MX165307B/en unknown
- 1989-06-29 AR AR89314293A patent/AR245773A1/en active
- 1989-06-29 BR BR898903195A patent/BR8903195A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0481500A (en) | 1992-03-16 |
| TR24383A (en) | 1991-09-23 |
| EP0349200B1 (en) | 1995-09-27 |
| AU624155B2 (en) | 1992-06-04 |
| IE892100L (en) | 1989-12-29 |
| EP0349200A2 (en) | 1990-01-03 |
| AR245773A1 (en) | 1994-02-28 |
| BR8903195A (en) | 1990-02-13 |
| NZ229756A (en) | 1992-04-28 |
| AU3713589A (en) | 1990-01-04 |
| DE68924373D1 (en) | 1995-11-02 |
| DK323989A (en) | 1989-12-30 |
| DK323989D0 (en) | 1989-06-29 |
| ES2076963T3 (en) | 1995-11-16 |
| JP2845953B2 (en) | 1999-01-13 |
| MX165307B (en) | 1992-11-04 |
| DE68924373T2 (en) | 1996-05-15 |
| EP0349200A3 (en) | 1990-06-20 |
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