US 3773671 A
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United States Patent [1 1 Hussain Nov. 20, 1973  PRODUCTION OF GRANULAR MIXTURES [7 5] Inventor: Ali Ghalib Mohammed Hussain,
, Elizabeth, NJ. i
 Assignee: Colgate-Palmolive Company, New
22 Filed: Sept. 8, 1971 21 Appl.No.: 178,800
Related U.S. Application Data  Continuation of Ser. No. 828,938, May 29, 1969,-
 U.S. Cl. 252/89, 195/63, 252/135, 252/DIG. 12  Int. Cl Clld 7/42  Field of Search 252/89, 135, 137;
 References Cited UNITED STATES PATENTS 3,451,935 6/1969 Roald 3,519,570 7/1970 McCarty 252/89 FOREIGN PATENTS OR APPLICATIONS 16,501 3/l959 Germany 252/89 Primary ExaminerWilliam E. Schulz Attorney l-lerbert S. Sylvester et al.
 ABSTRACT Process for producing granular enzyme product which comprise mixing an aqueous slurry of powdered enzyme preparation with hydrated pentasodium tripolyphosphate while agitating.
3 Claims, 4 Drawing Figures Imm L PRODUCTION OF GRANULAR MIXTURES This is a continuation of application Ser. No. 828,938 filed May 29, 1969 now. abandoned.
This invention relates to a method of making a granular non dusting detergent composition for use in laundry products.
Powdered enzymes have been employed in presoak and washing detergent compositions since they are particularly effective against various common stains which are fixed to textiles and laundry. In particular; proteolytic enzymes, which possess the ability to digest and degrade protein matter, are effective in removing from textiles and laundry proteinic stains such as blood, sweat, milk, cocoa, gravy and other sauces and the like. The digestion or degradation of proteinmatter facilitates removal of dirt by the detergent. Amylases and lipasos are also useful in detergent cleaning.
However, the use of powdered enzymes in such compositions has resulted in certain problems including the presence of an excessive amount of dust. Some individuals experience allergic reactions to the enzyme dust. Furthermore, detergent compositions containing enzymes have been subject to discoloration, formation of undesirable odor and caking.
It has been suggested to bind variouscompounds which are common builder salts in their hydratable form with enzymes. This may be done by contacting enzyme with an anhydrous or partially hydrated salt and adding water in insufficient amount to fully hydrate the salt. A considerable amount of enzyme dust is still present when the enzyme-hydratable salt composition is used. Discoloration and odor formation may also occur.
One aspect of this invention relates to the production of granules or beads containing the enzyme preparation and pentasodium tripolyphosphate (hereafter termed TPP) by mixing an aqueous slurry of the enzyme preparation with finely divided hydrated TPP. The invention provides a rapid convenient and economical method for producing a granular enzyme product which has good stability. It makes it possible to produce a product in which any dust is much lower in enzyme content than the product itself.
In one embodiment of the process the finely divided TPP is added to the aqueous slurry of powdered enzyme preparation while agitating, so that the slurry coats the surfaces of the hydrated TPP, the amount of water present being such as to provide a total water content (including water of hydration introduced with the TPP) of about 35 to 55 parts of water per 100 parts of TPP, calculated as anhydrous TPP. This proporation of water is in excess of the amount present in TPP hexahydrate, whose water content is'29.4 parts of water per 100 parts of TPP, calculated as anhydrous TPP. During mixing it is found that the mixture forms granules. This may be caused, I believe, by the acceleration of fine particles of the hydrated TPP to larger particles thereof or to agglomerates (of fine particles) produced in earlier stages of mixing. These granules, while more orless dry to the touch, are caky"; that is, the granules can be squeezed together in the hand to form a coherent mass or cake. in contrast, when hydrated sodium sulfate is substituted for the hydrated TPP a mushy mudlike mixture is obtained.
The formation of a slurry and the addition of the'TPP thereto, instead of spraying the slurry onto the granular TPP has many advantages. lt makes it possible to use smallerequipment, less expensive equipment, less manpower and less mechanical power.
The caky granules are then dried,- preferably in a fluidized bed in a stream of heated. air, at a relatively low temperature. Thus, the temperature reached in the bed may be in the range of about 40-60C- preferably about 4555C (e.g. about 50C); the temperature may be measured by simply inserting a thermometer into. the fluidized bed during drying. During drying the total water content is reduced to a level of about 20 to 30- parts of water per 100 parts of TPP (calculated as anhydrous TPP). The particle size distribution is substantially the same before and after the drying in the fluidized bed.
The resulting granular product is free-floating, has a low fines content, and shows good enzyme stability; even to.aging at 100 percent relative humidity at 49C. for one week the loss of enzyme activity is, say, about 25 percent.
In a preferred embodiment of the invention the hydrated TPP used as a starting material is itself a granular product of which over 40 percent (by weight), e.g. 50-70 percent, will be retained on 40 mesh sieve, having 0.42 mm openings; all sieve sizes given herein are U.S.Standard. Preferably substantially none of the material is retained on a 10 mesh sieve (whose openings are 2 mm in diameter). Very good results have been attained using a commercial grade of TPP hexahydrate which has a water. content of about -85 percent of that theoretically present in the hexahydrate; thus one commercial TPP hexahydrate has a water content of 18.3 percent based on the total weight (while pure TPP hexahydrate has a water content of 22.7 percent, based on total weight); a TPP content (calculated as anhydrous TTP) of 76 percent; a pryophosphate content, as Na P O- of 3.5 percent; an orthophosphate content, as Nag-IP0 of 0.3 percent; and a sodium thrimetaphosphate content, as NaPO of 1.9 percent.
The whole process can be effected very rapidly, using relatively inexpensive equipment. Thus the whole step of mixing the enzyme slurry and the hydrated TPP and forming caky granules therefrom can be effected in less than 5 minutes in a simpleRoss mixer and the material can then be delivered directly to the fluidized bed drier in which the drying can be effected in, say 5-l5 minutes, preferably about 10 minutes. I have found that the presence of the enzyme preparation appears to inhibit the rate of hydration of TPP; thus when partly hydrated TPP is used. as the starting material little, if any, hydration thereof occurs during mixing or drying.
The slurry of powdered enzyme preparation can be relatively concentrated, e.g. it may contain 100, 200,
300 or 400 parts of powdered enzyme preparation per parts of water. Especially good results have been obtained with slurries containing about 200 to 300 parts of powdered enzyme preparation per 100 parts of water. Typically the slurry is a mud-like mixture. When the hydrated TPP is added gradually the mixture thickens, then forms relatively large (about 2-5 cm in diameter). but very fragile aggregates which become smaller and smaller as the addition of'hydrated TPP with agitation continues. it is preferred to add the hydrated TPP at such a rate that substantially all the TPP becomes mixed in with the slurry (e.g. the hydrated TPP is added gradually, with. agitation, over a period of at least /2 minute, but less than about 5 minutes, preferably about 1 to 2 minutes).
Particularly good results are obtained using a well known Ross mixer which is of the double planetary type having a pair of mixing blades which rotate in overlapping circular paths about their parallel vertical axes while the axes themselves move in a circular path about the vertical axis of the mixing vessel and close to its cylindrical wall. Also useful are the well known Hobart mixer (which is of a single planetary type) or a ribbon mixer (e.g. a conventional Day mixer).
Preferably the process is carried out in such fashion as to produce granules which pass through a 10 mesh sieve (sieve opening 2 mm), more preferably pass through a 20 mesh sieve (sieve opening 0.84 mm) and are retained on an 80 mesh sieve (sieve opening 0.177 mm); the granules within that size range more preferably constitute a major portion (most preferably being at least about 60 percent, e.g. about 60 to 80 percent) of the total weight of the product.
In the preferred form of the invention the enzyme comprises a proteolytic enzYme which is active upon protein matter and catalyzes digestion or degradation of such matter when present as in linen or fabric stain in a hydrolysis reaction. The enzymes may be effective at a pH range of say about 4-12, and may be effective even at moderately high temperatures so long as the temperature does not degrade them. Some proteolytic enzymes are effective at up to about 80C. and higher. They are also effective at ambient temperature and lower to about 10C. Particular examples of proteolytic enzymes which may be used in the instant invention include pepsin, trypsin, chymotrypsin, papain, bromelin, colleginase, keratinase, carboxylase, amino peptidase, elastase, subtilisia and aspergillopepidase A and B. Preferred enzymes are substilisin enzymes manufactured and cultivated from special strains of spore forming bacteria, particularly bacillus subtilis.
Proteolytic enzymes such as Alcalase, Maxatase, Protease AP, Protease ATP 40, Protease ATP 120, Protease L-252 and Protease L-423 are among those enzymes derived from strains and spore foaming bacillus, such as bacillus subtillis.
Different proteolytic enzymes have different degrees of effectiveness in aiding in the removal of stains from textiles and linen. Particularly preferred as stain removing enzymes are subtilisin enzymes.
Metalloproteases which contain divalent ions such as calcium, magnesium or zine bound to their protein chains are of interest.
The enzyme preparations are generally extremely fine, often substantially impalable, powders. In a typical powdered enzyme preparation the particle diameter is mainly below 0.15 mm, generally above 0.01 mm,
I e.g. about 0.1 mm; for example, as much as 75 percent of the material may pass through a 100 mesh (U.S. Standard) sieve. In contrast, conventional spray dried granules of detergent compositionsare usually of very much larger particle size, with the major portion of the granules being at least about 0.2 mm in diameter, e.g.
about 0.3 or 0.4, or even 05, 1 or 2 mm.
The enzyme preparations are generally extremely diluted with salts such as calcium sulfate and inert materials. Chemically .they are typically stable in the pH range of 5 to and at an alkaline pH of 8.5 to 9. They can withstand temperatures of 49.C. to 77C. with relatively little decomposition for time periods varying from 2 hours at the higher temperatures to more than 1 day at the lower temperatures. Different proteolytic enzymes have different degrees of effectiveness in aiding in the removal of stains from textiles and linen.
Instead of, or in additionto, the proteolytic enzyme, an amylase may be present such as a bacterial amylase of the alpha type (e.g. obtained by fermentation of B. subtilis). One very suitable enzyme mixture contains both a bacterial amylase of the alpha type and an alkaline protease, preferably in proportions to supply about 100,000 to 400,000 Novo alpha-amylase units per Anson unit of said alkaline protease.
The enzyme content of the granules or beads can be varied widely, e.g. in the range of 2 50 percent of powdered enzyme preparation. When the powdered enzyme preparation has an alkaline protease content of 1.5 Anson units per gram, this range of course represents some 3 to Anson units per 100 grams of granules or beads. The invention finds its greatest utility, however, for the manufacture of granules or beads which are relatively rich in enzyme content, containing at least 10 percent of the enzyme preparation (corresponding to say at least 15 Anson units per 100 grams of the granules) and preferably at least 15 percent. In the final washing product, made for example by blending the enzyme containing granules or beads with other granular material (such as spray-dried hollow beads or spongeous low density granules), the content of powdered enzyme preparation is much lower, e.g. in the range of about 0.10 to 4.0 percent, preferably about 0.3 to 2.0 percent.
The amount of the enzyme mixture present in the detergent composition will, of course, depend to some extent on the amount of the detergent composition which is to be added to the wash water. For detergent compositions which are intended for use at concentrations of, say, about 0.15 percent in the wash water of an automatic home laundry machine, one suitable amount of enzyme mixture is such as to provide 1 Anson unit of the alkaline protease for each 100 to 500 (e.g. 200 to 400) grams of the detergent composition.
The enzyme-containing granules or beads produced in accordance with this invention may be added to a wide variety of washing products. Thus, they may be incorporated in a laundry presoak product or in a laundry detergent or in a dishwashing product. A typical presoak product contains a relatively high concentration of builder salt such as about 30 to percent penta-sodium tripolyphosphate (calculated as anhydrous pentasodium tripolyphosphate), about 2 to 10 percent of organic surface active detergent, plus other ingredients such as sodium silicate (which acts as a builder salt and also acts to inhibit corrosion of aluminum surfaces), brightening agents and sodium sulfate. A laundry detergent generally has a lower ratio of builder salt to organic surface active agent (e.g. a ratio in the range of about 5:1 to 15:1). Dishwashing products, designed for use in automatic dishwashers, are on the other hand usually more alkaline, containing a very high proportion of alkaline builder salt, such as a mixture of the pentasodium tripolyphosphate and sodium silicate; they contain little, if any, organic surface active detergent, e.g. about 0.2 to 3 percent and usually also contains a minor proportion (e.g. 0.5 to 5 percent) of an agent to prevent water-spotting such as a dry watersoluble compound which on contact with water, liberates hypochlorite chlorine (e.g. a heterocyclic dichloroisocyanurate); alternatively, a chlorinated phosphate (such as the well known chlorinated trisodium phosphate) may be used to supply both hypochlorite chlorine and some phosphate.
ln formulating the washing products, the watersoluble builder salts may be phosphates and particularly condensed phosphates (e.g. pyrophosphates or tripolyphosphates), silicates, borates and carbonates (including bicarbonates), as well as organic builders such as salts of nitrilotriacetic acid or ethylene diamine tetracetic acid. Sodium and potassium salts are preferred. Specific examples are sodium tripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate, sodium carbonate, sodium bicarbonate, sodium sesquicarbonate, sodium tetraborate, sodium silicate, salts (e.g. Na salt) of methylene diphosphonic acid, disodium diglycollate, trisodium nitrilotriacetate, or mixtures of such builders, including mixtures of pentasodium tripolyphosphate and trisodium nitrilotriacetate in a ratio, of these two builders, of 1:10 to :1, e.g. 1:1.
The organic surface active agent may be an anionic, nonionic or amphoteric surface active agent; mixtures of two or more such agents may be used.
The anionic surface active agents include these surface active or detergent compounds which contain an organic hydrophobic group and an anionic solubilizing group. Typical examples of anionic solubilizing groups are sulfonate, sulfate, carboxylate, phosphonate and phosphate. Examples of suitable anionic detergents which fall within the scope of the invention include the soaps, such as the water-soluble salts of higher fatty acids or resin acids, such as may be derived from fats, oils and waxes of animal, vegetable origin, e.g. the sodium soaps of tallow, grease, coconut oil, tall oil and mixtures thereof; and the sulfated and sulfonated synthetic detergents, particularly those having about 8 to 26, and preferably about 12 to 22, carbon atoms to the molecule.
As examples of suitable synthetic anionic detergents there may be cited the higher alkyl mononuclear aromatic sulfonates such as the higher alkyl benzene sulfonates containing from 10 to 16 carbon atoms in the alkyl group in a straight or branched chain, e.g.', the sodium salts of higher alkyl benzene sulfonates or of the higher alkyl toluene, xylene and phenol sulfonates; alkyl naphthalene sulfonate, ammonium diamyl naphthalene sulfonate, and sodium dinonyl naphthalene sulfonate. In one preferred type of composition there is used a linear alkyl benzene sulfonate having a high content of 3- (or higher) phenyl isomers and a correspondingly low content (well below 50 percent) of 2- (or lower) phenyl isomers; in other terminology, the benzene ring is preferably attached in large part at the 3 or higher (e.g. 4, 5, 6 or 7) position of the alkyl group and the content of isomers in which the benzene ring is attached at the 2 or 1 position is correspondingly low. Particularly preferred materials are set forth in U.S. Pat. No. 3,320,174, May 16, 1967, of J. Rubinfeld.
Other anionic detergents are the olefin sulfonates, including long chain alkene sulfonates, long chain hydroxyalkane sulfonates or mixtures of alkenesulfonates and hydroxylalkane-sulfonates. These olefin sulfonate detergents may be prepared, in known manner, by the reaction of S0 with long chain olefins (of 8-25, preferably 12-21 carbon atoms) of the formula RCH=CHR,, where R is alkyl and R, is alkyl or hydrogen, to produce a mixture of sultones and alkenesulfonic acids, which mixture is then treated to convert the sultones to sulfonates. Examples of other sulfate or sulfonate detergents are paraffin sulfonates having, for example, about 10-20, preferably about 15-20, carbon atoms such as the primary paraffin sulfonates made by reacting long chain alpha olefins and bisulfites (e.g. sodium bisulfite) or paraffin sulfonates having two sulfonate groups distributed along the paraffin chain such as the products made by reacting a long chain paraffin with sulfur dioxide and oxygen under ultraviolet light followed by neutralization with NaOH or other suitable base (as in U.S. Pat. Nos. 2,503,280; 2,507,088; 3,260,741; 3,372,188 and German patent 735,096); sulfates of higher alcohols; salts of a-sulfofatty esters (e.g. of about 10 to 20 carbon atoms, such as methyl a-sulfomyristate or a-sulfotallowate).
Examples of sulfates of higher alcohols are sodium lauryl sulfate, sodium tallow alcohol sulfate, Turkey Red Oil or other sulfated oils, or sulfates of monoor di-glycerides of fatty acids (e.g. stearic monoglyceride monosulfate), alkyl poly (ethenoxy) other sulfates such as the sulfates of the condensation products of ethylene oxide and lauryl alcohol (usually having 1 to 5 ethenoxy groups per molecule); lauryl or other higher alkyl glyceryl ether sulfonates; aromatic poly (ethenoxy) other sulfates such as the sulfates of the condensation products of ethylene oxide and nonyl phenol (usually having 1 to 6 oxethylene groups per molecule).
The suitable anionic detergents include also the acyl sarcosinates (e.g. sodium lauroylsarcosinate) the acyl esters (e.g. oleic acid ester) of isothionates, and the acyl N-methyl taurides (e.g. potassium N-methyl lauroylor oleyl tauridge).
The most highly preferred water soluble anionic detergent compounds are the ammonium and substituted ammonium (such as mono-, diand triethanolamine), alkali metal (such as sodium and potassium) and alkaline earth metal (such as calcium and magnesium) salts of the higher alkyl benzene sulfonates, olefin sufonates, the higher alkyl sulfates, and the higher fatty acid monoglyceride sulfates. The particulsr salt will be suitably selected depending upon the particular formulation and the proportions therein.
Nonionic surface active agents include those surfaces active or detergent compounds which contain an organic hydrophobic group and a hydrophilic group which is a reaction product of a solubilizing group such as carboxylate, hydroxyl, amido or amino with ethylene oxide or with the polyhydration product thereof, polyethylene glycol.
As examples of nonionic surface active agents which may be used there may be noted the condensation products of alkyl phenols with ethylene oxide, e.g., the reaction product of isooctyl phenol with about 6 to 30 ethylene oxide units; condensation products of alkyl thiophenols with 10 to 15 ethylene oxide units; condensation products of higher fatty alcohols such as tridecyl alcohol with ethylene oxide; ethylene oxide addends of monoesters of hexahydric alcohols and inner ethers thereof such as sorbitan monolaurate, sorbitol monooleate and manitan monopalmitate, and the condensation products mannitan polypropylene glycol with ethylene oxide.
A particularly suitable composition, for use as a granular detergent material contains a mixture of a linear alkylbenzenesulfonate, as previously described, soap and a non-ionic detergent, with the soap and nonionic detergent being present in minor portions. The ratios of the amounts of (A) soap, and (B) nonionic detergent, to (C) the total amount of the synthetic anionic sulfate and sulfonate detergent, in this mixture, are preferably as follows: AzC, about 1:10 to 1:2, preferably about 1:4 to 1:6, on an anhydrous basis; B:C about 1:10 to 1:3, e.g. about 1:4 to 1:6, on an anhydrous basis. The component (C) may comprise a blend of the linear alkylbenzenesulfonate detergent with other anionic synthetic sulfate or sulfonate detergents (e.g. olefin sulfonates, paraffin sulfonates having the sulfonate groups distributed along the paraffin chain, or alkyl sulfonates) with the alkylbenzenesulfonate consisting, say, '75, k or 36 of this blend.
Examples of suitable amphoteric detergents are those containing both an anionic and a cationic group and a hydrophobic organic group, which is advantageously a higher aliphatic radical, e.g. of -20 carbon atoms. Among these are the N-long chain alkyl aminocarboxylic acids (e.g. of the formula the N-long chain alkyl iminodicarboxylic acids (e.g. of the formula RN(RCOOM) and the N-long chain alkyl betains (e.g. of the formula where R is a long chain alkyl group, e.g. of about 10-20 carbons, R is a divalent radical joining the amino and carboxyl portions of an amino acid (e.g. an alkylene radical of 1-4 carbon atoms), N is hydrogen or a salt-forming metal, R is a hydrogen or another monovalent substituent (e.g. methyl or other lower alkyl), and R and R are monovalent substituents joined to the nitrogen by carbon-to-nitrogen bonds (e.g. methyl or other lower alkyl substituents). Examples of specific amphoteric detergents are N-alkyl-betaaminopropionic acid, N-a1ky1-beta-iminodipropionic acid, and N-alkyl, N,N-dimethyl glycine; the alkyl group may be, for example, that derived from coco fatty alcohol, lauryl alcohol, myristyl alcohol (or a lauryl-myristyl mixture), hydrogenated tallow alcohol, cetyl, stearyl, or blends of such alcohols. The substituted aminopropionic and iminodipropionic acids are often supplied in the sodium or other salt forms, which may likewise be used in the practice of this invention. Examples of other amphoteric detergents are the fatty imidazolines such as those made by reacting a long chain fatty acid (e.g. of 10 to carbon atoms) with diethyl ene triamine and monohalocarboxylic acids having 2 to 6 carbon atoms, e.g. l-coco-5-hydroxethyl-5-carboxymethylimidazoline; betaines containing a sulfonic group instead of the carboxylic groups; betaines in which the long chain substituent is joined to the carboxylic group without an intervening nitrogen atom, e.g. inner salts of 2-trimethylamino fatty acids such as 2-trimethylaminolauric acid, and compounds of any of the previously mentioned types but in which the nitrogen atoms is replaced by phosphorous.
Various other materials may be present in the granular products. Thus, materials such as the higher fatty acid amides maybe added to improve detergency and modify the foaming properties in a desirable manner. Examples thereof are the higher fatty acid alkanolamides, preferably having 2-3 carbons in each alkanol group and a fatty acyl radical within the range of 10-18 carbons, preferably 10-14 carbons, such as lauric or myristic monothanolamides, diethanolamides and isopropanol-amides. Tertiary higher alkyl amino oxides such as having about l0-18 carbons in one alkyl group, e.g. lauryl of myristyl dimethylamine oxide, may be added also. Fatty alcohols of 10-18 carbons such as lauryl or coconut fatty alcohols, or cetyl alcohol are suitable additives also. A hydrotropic material such as the lower alkyl aryl sulfonates, e.g. sodium toluene or xylene sulfonates, can assist processing also. In general, these materials are added in minor amounts, usually from about k to 10 percent, preferably 1 to 6 percent, based on the total solids.
The mixtures may also contain optical brightening agents or fluorescent dyes (e.g. in amounts in the range of about 1/20 to k percent); germicidal ingredients such as halogenated carbanilides, e.g. trichlorocarbanide, halogenated salicylanilide, e.g. tribromosalicylanilide, halogenated bisphenols, e.g. hexachlorophene, halogenated trifluoromethyldiphenyl urea, zinc salt of 1-hydroxy-2-pyridinethione and the like (e.g. in amounts in the range of about 1/50 to 2 percent); soil-suspending suspending agents such as sodium carboxymethyl cellulose or polyvinyl alcohol, preferably both, or other soluble polymeric materials, such as methyl cellulose (the amount of suspending agent being, for example, in the range of about 1/20 to 2 percent); antioxidants such as 2,6-di-tertbutylphenol, or other phenolic antioxidant materials (e.g. in amounts in the range of about 0.001 to 0.1 percent), coloring agents, bleaching agents and other additives.
The following Examples are given to illustrate this invention further. In these Examples, as in the rest of the application, all proportions are by weight unless otherwise specified. Also, in these Examples, the pressure is atmospheric unless otherwise specified.
EXAMPLE 1 A thin mud-like slurry is prepared in Standard Ross Mixer (of the double planetary type) by mixing at room temperature 24.0 parts of powdered proteolytic subtilisin enzyme preparation (Alcalase, 1.5 Anson Units/g) and 10.8 parts water. Then 65.2 parts of a commercial granular pentasodium tripolyphosphate hexahydrate are added granually, at the rate of about 45 parts per minute; the mixing is continued for about 3 minutes after addition of the pentasodium tripolyphosphate hexahydrate has concluded. in this example, the total weight of the batch is about 90.9 Kg (200 lbs.), the volume of the mixing vessel is about 40 gallons, and the speed of rotation of the double blade about the axis of the vessel is about 26 RPM.
The pentasodium tripolyphosphate hexahydrate used in this Example has the following screen analyses:
Screen Mesh Opening (mm) Remaining on Mesh Fan Total 100.0
The results of another analysis of another portion of the same material are: +10 mesh, 0 percent; +20, 1.5 percent; +30, 26 percent; +60, 83.9 percent, -100 mesh, 2.4 percent. This TPP hexahydrate has a total water content of 18.3 percent, a free water content of 0.55 percent, of pH of 9.87, a bulky density of 0.705 g/cc and a P content averaging 47.16 percent.
The caky granules resulting from the mixing process are fed to a fluidized bed drier where they are fluidized by a stream of heated air and subjected to the drying action of the air for a period of minutes at a bed temperature rising to 50C.
The product is a granular material containing the enzyme distributed thoroughly therein, showing very little if any tendency to dust and showing very good resistance to loss of enzyme activity on aging. Its screen analysis (after removal of a very small portion of material retained on a 10 mesh sieve) is as follows:
Screen Mesh Remaining on Mesh 20 l 1.7 40 47.0 60 26.8 80 8.4 100 2.5 Pan 3.5
The proteolytic subtilisin enzyme preparation used in the foregoing Example has its minimum proteolytic activity at a pH of 8 9. This activity as measured at pH 7.5 on the commercial enzyme preparation available from Novo Industri A/S, Copenhagen, Denmark is about 1.5 Anson Units per gram of the enzyme. The commercial enzyme preparation is a raw extract of bacillus subtillis culture and contains about 6 percent of pure crystallized proteolytic material. The preparation is an extremely fine powder; typically the particle diameter is mainly below 0.15 mm, generally above 0.01
mm, e.g. about 0.1 mm, and as much as 50 percent or even 75 percent of material may pass through a 100 mesh sieve. The preparation contains about 70 percent NaCl and about -18 percent Na SO Its organic content is in the neighborhood of 11 percent.
EXAMPLE 2 Example 1 is repeated except that one starts with an enzyme preparation which is richer in the enzyme. Here there are used 9.0 parts of enzyme preparation having an enzyme content of 4.0 Anson units per gram, 14.0 parts of water and 77 parts of the TPP hexahydrate.
EXAMPLE 3 The products of each of the foregoing Examples are dry blended with spray dried hollow beads ofa mixture of pentasodium tirpolyphosphate, an organic detergent (sodium linear tridecylbenzenesulfonate), sodium silicate (Na- O:SiO ratio 1.012.35), optical brighteners, and sodium sulfate to give, in each case, a composition having the following approximate analysis: total anhydrous phosphate solids 70 percent, organic detergent 6.75 percent, sodium silicate 5.1 percent, brighteners 018 Percent, 1 Qrwr (P or minu 12mm). the enzyme preparation 0.76 percent, and the balance being sodium sulfate.
The resulting granular solid mixture is a highly effective presoak product, which is mixed with water (e.g. to form a 0.19 percent solution of the whole solid mixture) and used for soaking soiled and stained cotton garments or other fabric material (e.g. for l to 24 hours) prior to washing said fabric materials.
The accompanying drawings.are photomicrographs,
with the scale indicated for each picture for the material in the foreground. FIGS. 1, 2 and 3 are made with a conventional scanning electron microscope (in which the specimen is scanned with an electron beam, the electrons reflected from the surface of the specimen are collected and used, through intermediate light signals, to modulate the scanning beam of a cathode ray tube to give a picture like that seen on a television screen); the specimens are pre-coated with a very thin layer of conductive material (e.g. a 50A. thick layer of gold, applied in a vacuum) as is conventional in the use of the instrument, to give a clearer picture. The scanning electron microscope has a much greater depth of field than an ordinary light microscope.
FIG. 1 shows two granules of the hydrated TPP (commercial porous TPP hexahydrate as used in the foregoing Examples). The wormy elements near the bottom of each granule are merely the adhesive used to attach the granules to the base on which they rest in the instrument.
FIG. 2 shows a granule of the product of Example I. It can be seen that the granule includes attached smaller particles agglomerated therewith.
FIG. 3 is a view showing several granules of the product of Example 1.
FIG. 4 is a view of the granules of the product of Example l, taken with a light microscope using transmitted light, with the specimen immersed in oil (a conventional microscope technique). The transparent crystals are believed to be sodium chloride crystals from the enzyme preparation; some of these have apparently been formed by solution in the aqueous medium of the slurry followed by recrystallization.
It will be apparent that variations of the invention may be made and equivalents substituted therefor.
1. Process for producing a granular enzymecontaining product which comprises adding porous granules of hydrated pentasodium tripolyphosphate, whose water content is at least about percent of that of pure pentasodium tripolyphosphate hexahydrate and whose particle size distribution is such that over 40 percent is retained on a 40 mesh sieve and substantially none is retained on a 10 mesh sieve, gradually to an aqueous slurry of protease enzyme fine powder while agitating, substantially all said tripolyphosphate being added to said slurry over a period of at least one half minute but less than five minutes, said slurry containing about 200 to 400 parts of the enzyme powder per parts of water, the amount of water in the slurry being such as to provide in said mixture a total water content (including water of hydration present in said tripolyphosphate) of about 35 to 55 parts of water per 100 parts of pentasodium tripolyphosphate, calculated as anhydrous pentasodium tripolyphosphate, whereby the resulting mixture thickens, then forms fragile aggregates which become smaller as the addition of said by: drated tripolyphosphate with agitation continues, forming caky granules, which if squeezed together in the hand will form a coherent mass, and drying said caky granules to form free-flowing granules by subjecting said caky granules to air having a temperature of up to about 60C. until the total water content is reduced to about 20 to 30 parts of water per 100 parts of pentasodium tripolyphosphate, calculated as anhydrous pentasodium tripolyphosphate.
2. Process as in claim 1 in which said caky granules content about 75-85 percent of that of pure pentasoare dried in a fluidized bed at a temperature in the dium tripolyphosphate hexahydrate and said slurry is a range of about 40-60C.
3. Process as in claim 2 in which the granules of hydrated tripolyphosphate feed material have a water 5 mud-like mixture.
Dedication 3,773,671.-Ali Ghalz'b M ohammwd Husswin, Elizabeth, NJ. PRODUCTION OF GRANULAR MIXTURES. Patent dated Nov. 20, 1973. Dedication filed Mar. 20, 1980, by the assignee, Uolgate-Palmohve Oompwny.
Hereby dedicates to the Public the entire remaining term of said patent.
[Oyficz'al Gazette, M ay 20, 1980.]