CA2006687C

CA2006687C - Hydrated alkali metal phosphate and silicated salt composition

Info

Publication number: CA2006687C
Application number: CA002006687A
Authority: CA
Inventors: Anthony A. Rapisarda; Joseph Romeo
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1988-12-30
Filing date: 1989-12-27
Publication date: 1994-12-27
Anticipated expiration: 2009-12-27
Also published as: CA2006687A1; US4973419A

Abstract

Compositions suitable for use as detergents comprise a non-silicate-coated alkali metal phosphate salt hydrated to at least about 50% by weight, and an inorganic salt selected from alkali metal carbonates and sulfates. The compositions for use in, e.g. dishwashing have improved solubility and dispersion characteristics.

Description

f.00~;687 HYDRATED ALKALI METAL PHOSPHATE AND SILICATED SALT COMPOSITIONS

BACKGROUND OF THE INVENTION
Automatic dishwashing detergent powders typically include substantial amounts of inorganic phosphates, which pro-vide alkalinity and sequester calcium ions. Another importantingredient in powdered autodish detergents i8 silicate, which functions to prevent corrosion and protect overglaze. It is gen-erally preferred to use liquid silicate solution as the silicate source in such compositions since it tends to be less expensive and is a good agglomerating agent.

- There are various types of processes for manufacturing powdered detergent compositions. Among these may be mentioned spray drying, agglomerating, dry blending and hybrids thereof.
The manufacture of automatic dishwashing detergents primarily involves agglomeration or dry blending. Agglomeration processes for preparing automatic dishwashing detergents frequently involve spraying the liquid silicates onto mixtures consisting mainly of dry salt ingre~ients such as sodium tripolyphosphate, chlorinated trisodium phosphate, sodium carbonate, sodium sulfate, sodium chloride, etc.

-l- C6078 20066a7 It is frequently difficult to load the desired amount of liquid silicate onto the salts to be used in the composition.
One reason for this is that it may be desirable that the phos-phates be prehydrated since phosphates lacking moi~turo tend to cake in the dishwasher's dispenser cup. In such case8, the pre8 ence of water in the phosphates l-imits the amount of silicate which can be absorbed. The difficulty in loading silicates onto hydrated phosphates tends to result in an uneven distribution of size and forr,tation of fines which give the product an undesir~ble particle size distribution. In addition, agglomerated products have a tendency to cake in the dispenser cup.

An article by E.J. Schuck and R.E. Temple entitled ~ "Silicated Sodium Carbonate As A Detergent Builder," Proc.
Mid-Year Meet., Chem. Spec. Manufac. Assoc. 1972, 58, 82-85 dis-closes silicated soda ash builders in automatic dishwashing detergents including tripolyphosphate. An example discloses silicated soda ash having a moisture level of 4%. It is not stated that the tripolyphosphate is hydrated. The silicated sodium carbonate is said to give acceptable solubility and good open storage stability.

"Soap/Cosmetics/Chemical Specialties," August, 1987, page 89 discloses a process for making a free-flowing granular non-phosphate machine dishwashing detergent. The process begins by spraying a mixture of surfactant, water and liquid Eilicate onto soda ash, after which sodium metasilicate i8 added and mixed continuously. .

Temple, U.S. Patent No. 3,821,119 disclo~e~ a method o~
preparing a particulate detergent builder which lnclud~ a~x~g liquid sodium silicate with anhydrous soda ash, passing the resultant granules through a screen and rapidly heating the screened material to a temperature in excess of 100C.

SUMM~.RY OF THE INVENTION

The first embodiment of the present invention i8 directed to the discovery that certain levels of phosphate hydra-tion are important in compositions which include silicated sodium carbonate and particular phosphate salts. The first embodiment, therefore, includes compositions comprising alkali metal tripolyphosphate salts hydrated to a specified level and silicated sodium carbonate and/or silicated mixtures of sodium carbonate with sodium sulfate and to a process for preparing such compositions.

In particular, the first embodiment relates to compositions, suitable for use as automatic dishw~hin~
detergents, laundry detergents and for other purposes, which com-prise a non-silicate-coated alkali metal tripolyphosphate salt hydrated to at least about 50% by weight, an inorganic salt selected from the group consisting of i) alkali metal carbonate ~3~ C6078 ~006~i87 and mixtures of alkali metal carbonate and alkali metal sulfate wherein the inorganic salt is admixed with alkali metal silicate.
It has been found that when such compositions are utilized as or in automatic dishwashing formulations, there is i~provod solubility and less tendency to cake in the dispenser cup. The hydrated phosphate may even be used without the silicated non-phosphorus salt.

The-process of the first aspect of the invention involves mixing together the separately prepared or obtained hydrated phosphate and silicated alkali metal salt. The silicate is more completely loaded onto the alkali metal salt than is the case when it is sprayed onto mixtures including phosphate salts.
Moreover, the process effects a substantial savings over those wherein the phosphate is hydrated together with other salts in that excess water is generally?used and absorbed by the other salts. Consequently, these processes require extensive drying operations to remove the excess water.

It has also been discovered that when silicated alkali metal carbonate or mixtures thereof with other non-phosphate alkali metal salts are prepared under specified conditions and/or possess a particular level of moisture, such agglomerates have improved characteristics for use in automatic dishwashing deter-gent and other formulations. In accordance with this second embodiment of the invention, the silicated soda ash is condi-c6078 tioned by exposing the silicated salt to hot air 80 that the silicated salt attains a temperature in the range of 120 to 150F. Conditioning times range from 5 to 25 minutes. It has also been found to be advantageous for the ~ilicated ~lX~ t~l inorganic salt to have a moisture level of at least 5~ ~y ~ght, preferably 6%, and especially at least 7.5%. Preferably, the moisture level does not exceed 12% by weight. Therefore, these second aspects of the invention include processes for preparing silic~ted salts, silicated salts prepared by the proceQseR and silicated salts having the requisite moisture levels. The fluidized bed-treated powder must attain within 5 to 25 minutes, a temperature of at least 120F and the temperature must not exceed 150F before removal from the fluidized bed.

In an especially preferred embodiment of the invention, the first two embodiments are combined such that phosphate having the preferred levels of hydration are utilized together with the preferred silicated salts of the second embodiment.

DETAILED DESCRIPTION OF THE INVENTION

)20 The compositions of the present invention preferablytake the form of automatic dishwashing detergents and processes for their preparation, but may take the form of other types of formulations including laundry detergent and other classes of compositions.

2006Çi87 Automatic dishwashing compositions according to the invention will typically include an alkali metal inorganic phos-phate builder salt which has not been sprayed or otherwise admixed with silicate and when the builder i8 sodium tripolyphosphate, it is preferably hydrated in accordanc- Wlth the first aspect of the invention. The level of hydration of sodium tripolyphosphate is preferably at least 50% by weight, more preferably at least 60% and even more preferably at least 75%.

Total hydrated phosphate builder salt levels in auto-matic dishwashing compositions according to the invention will typically range up to about 90%, preferably from 10 to 70%j still preferably from 20 to 60% by weight. Suitable phosphate builder salts include trisodium phosphate, tetrasodium pyrophosphate, sodium acid pyrophosphate, sodium tripolyphosphate hexahydrate, sodium monobasic phosphate, sodium dibasic phosphate and sodium hexametaphosphate or mixtures thereof. The potassium, lithium, ammonium, methylammonium, diethanolammonium, triethanolammonium, other substituted ammonium, mono-, di- and triethanolamine, methylamine, other amine salts and mixtures thereof may be used ) as well. Of course, if chlorine bleach is used, ammonium and amine-containing compounds should be avoided.

In accordance with the second embodiment of the invention, automatic dishwashing compositions-preferably include 200668~

` up to 80%, preferably from S to 60%, especially 10 to 50% by weight of a silicated alkali metal or ammonium or substituted ammonium inorganic, non-phosphorus salt. Preferably the salt is alkali metal or ammonium carbonate, bicarbonate or sesquicarbonate or mixtures thereof or a mixture thereof wlth other alkali metal inor~anic salts ~uch as sulfate. The weight ratio of alkali metal carbonate, bicarbonate or ses~uicarbonate or mixtures thereof to alkali metal sulfate or other inorganic salt or mixtures thereof is from 10:1 to 1:10, preferably 5:1 to 1:5. Other inorganic, non-phosphorus salts include borax, and limited amounts of alkali metal or ~ ~o~jum chloride and and mix-tures thereof. From 10 to 50% by weight of non-silicated inorganic, non-phosphorus salts including crystalline and amor-phous aluminosilicates, solid silicates and salts mentioned above may be included as well. Preferably, the silicated non-phosphate salt is conditioned to provide about 40 to 70% loss of 8il icate moisture. The product density is preferably in the range of 40-50 lbs/cu ft., especially about 47 lbs/cu ft. Generally, the salt is "silicated" by spraying with an a~ueous silicate -~olution and agglomerated.
) Compositions including silicated inorganic salt in accordance with the second asp~cts of the invention preferably also include alkali metal inorganic phosphate according to the first aspect of the invention.j The hydration level of the phos-phate is most significant when the ratio of silicated inorganic ~7~ C6078 Z006fi~37 salt to non-silicate-coated alkali metal inorganic phosphate i8 not greater than 70:30, particularly not greater than 60:40 and especially not greater than 55:45.

The compositions of this invention generally cont~
sodium or potassium silicate. This material is employed as a cleaning ingredient, source of alkalinity, metal corrosion inhib-itor and protector of glaze on china tableware. Especially effective is sodium silicate having a ratio of SiO2:Na20 of from about 1.0 to about 3.3, preferably from about 2 to about 3.2.

0 The non-phosphate inorganic salt which is to be sprayed with silicate preferably is of a size such that a m~ximl~m of 53 is held on a U.S. 60 mesh.

Automatic dishwashing detergents according to the inven-tion may also include organic builders, preferably at a level of from 0.5 to 30%. These may include water-soluble, i.e., sodium, potassium, ammonium salts of aminopolycarboxylic acids and hydroxycarboxylic acids and mixtures thereof. The acid portion of the salt may be derived from acids such as nitrilotriacetic acid (NTA), N-(2-hydroxyethyl) nitrilodiacetic acid, nitrilodiacetic acid, ethylenediaminetetraacetic acid (EDTA), N-(2-hydroxyethyl) ethylenediamine triacetic acid, 2-hydroxyethyliminodiacetic acid, diethylenetriamine pentaacetic acid, citric acid, etc., and mixtures thereof. Polyacrylate builders and polyacetal carboxylates such as those described in U.S. Patent Nos. 4,144,226 and 4,146,495 may also be used.

Other useful organic detergent builders include sodium and potassium salts of the following: phytates, polyphosphonates, oxydisuccinates, oxydiacetates, carboxymethyloxy succinates, tetracarboxylates, starch and oxi-dized heteropolymeric polysaccharides.

A wide variety of bleaching agents may be employed foruse with these detergent powders. Both haloqen and peroxygen type bleaches are encompassed by this inventicn.

Among the suitable halogen donor bleaches are 0 heterocyclic N-bromo and N-chloro imides such as trichlorocyanuric, tribromocyanuric, dibromo- and dichlorocyanuric acids, and salts thereof with water-solubiling cations such as potassium and sodium. An example of the hydratèd dichlorocyanuric acid is Clearon CDB56, a product manufactured by the FMC Corporation. Such bleaching agents may be employed in admixtures comprising two or more distinct chlorine donors. An example of a commercial mixed system is one available from the Monsanto Chemical Company under the trademark designation "ACL-66" (ACL signifying "available chlorine" and the numerical )20 designation "66", indicating the parts per pound of available chlorine) which comprises a mixture of potassium dichloroisocyanurate (4 parts) and trichloroisocyanurate acid (l part).

Other N-bromo and N-chloro imides may also be used such as N-brominated and N-chlorinated succinimide, malonimide, _9_ C6078 .

phthal imide and naphthalimide. Other compounds include the hydantoins, such as l, 3-dibromo and l,3-dichloro-5,5-dimehtylhydantoin, N-monochloro-C, C-dimentylhydantoin methylene-bis(N-bromo-C,C-dimethylhydantoin);
1,3-dibromo and 1,3-dichloro 5,S-isobutylhydantoin; 1,3-dl~romo and 1,3-dichloro 5-methyl-5-n-amylhydantoin, and the like.
Further useful hypohalite liberating agents comprise tribromomelamine and trichloromelamine.

Dry, particulate, water-soluble anhydrous inorganic salts are likewise suitable for use herein such as lithium, sodium or calcium hypochlorite and hypobromite.

The hypohalite liberating agent, may, if desired, be provided in a form of a stable solid complex or hydrate.
Examples include sodium p-toluene-sulfo-bromoamine-trihydrate, sodium benzene-sulfo-chloroamine-dihydrate, calcium hypobromite tetrahydrate, calcium hypochlorite tetrahydrate, etc. Brominated and chlorinated trisodium phosphate formed by the reaction of the corresponding sodium hypohalite solution with trisodium phosphate (and water if necessary) likewise comprise efficacious materials.
) Preferred chlorinating agents include potassium and sodium dichloroisocyanurate dihydrate, chlorinated trisodium phosphate and calcium hypochlorite. Particularly preferred are sodium or potassium dichloroisocyanurate dihydrate. Preferred concentrations of all of these materials should be such that they provide about 0.2 to about l.5% available chlorine. Hypohalite liberating compounds may generally be employed in automatic dishwashing detergents at a level of from 0.5 to 5% by weight, preferably from 0.5 to 3%.

Suitable chlorine-releasing agents are also disclosed in the ACS monograph entitled "Chlorine--Its Manufacture, Properties and Uses" by Sconce, published by Reinhold in 1962. This book is incorporated by reference. - -Among the oxygen bleaches which may be included in the invention are alkali metal and ammonium salts of inorganic peroxygen compounds such as perborates, percarbonates, persulfates, dipersulfates and the like. Generally the inorganic oxygen compound will be used in conjunction with an activator such as TAED ttetraacetyl ethylene diamine), ~odium benzoyl oxybenzene sulfonate or choline sulfophenyl carbonate or a cata-lyst such as manganese or other transition metal, as is well know~ in the bleaching art. Insoluble organic peroxides such as diperoxydodecanedioic acid (DPDA) or lauroyl peroxide may also be - used. Generally, the peroxygen compounds are present at a level )20 of from 0.5 to 20% by weight, 0.005 to 5% catalyst and l or 0.5 to 30% activator.

The pH of automatic dishwashing compositions in accor-dance with the invention preferably ranges from 9 to 12, espe-cially from lQ to ll. In general, the alkalinity of the -ll- c6078 compo~ition is adjusted by varying the levels of alkaline builder salt.

~ ater-soluble organic detergents may be includod in ~h~
automatic dishwashing compositions according to the inv~nt~n.
They may be included in liquids sprayed onto the inorganic salt or in the water used to hydrate the phosphate or may otherwise be added to the compositions. It is not necessary that the liquid silicate sprayed onto the sodium carbonate or other non-phosphate, inorganic salt in t~e process of the invention include any surfactant. If surfactant is included in one or more liquids to be sprayed onto the inorganic salt, it may be present either together with the silicate in the silicate solution or sprayed on separately.

Generally, the water-soluble organic detergents will be included at a level of from 0 to 15% by weight, preferably 0.5 to S%, especially from 1 to 3%. The detergent may be anionic, nonionic, cationic, zwitterionic, amphoteric or mixtures thereof.
~ow-foaming, nonionic surfactants are preferred.

Nonionic surfactants include those 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 proylene oxide or with a polyhydration product thereof such as polyethylene glycol.

,.-20066~7 Nonionic synthetic detergents can be broadly defined ascompounds produced by the condensation of alkylene oxide ~roups with an organic hydrophobic compound which may be aliphatic or alkyl aromatic in nature. The length of the ~ydrophll~c or polyoxyalkylene radical which is condensed with any particul~r hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements. Illustrative but not lim-iting examples of the various chemical types suitable as nonionic surfactants include:

! (a) polyoxyethylene and/or polyoxypropylene condensates of aliphatic carboxylic acids, whether linear- or branched-chain - and unsaturated or saturated, containin~ from about 8 to about 18 carbon atoms in the aliphatic chain and incorporating from 5 to about 50 ethylene oxide or propylene oxide units. Suitable car-boxylic acids include "coconut" fatty acids (derived from coconut oil) which contain an average of about 12 carbon atoms, "tallow"
fatty acids (derived from tallow-class fats) which contain a myristic acid, stearic acid and lauric acid.

~20 (b) polyoxyethylene and/or polyoxypropylene condensates of aliphatic alcohols, whether linear- or branched-chain and unsaturated or saturated, containing from about 6 to about 24 carbon atoms and incorporating from about 5 to about 50 ethylene oxide or propylene oxide units. Suitable alcohols include the 20066~37 "coconut" fatty alcohol, "tallow" fatty alcohol, lauryl alcohol, myristyl alcohol and oleyl alcohol. Particularly preferred nonionic surfactant compounds in this category are the "Neodo}"
type products, a registered trademark of the Shell Ch~m~cal Company.

Included within this category are nonionic surfactants having the formula:

R0- (CH2CH0)x(CH2CH20)y(CH2CHO)z- H
R' R"
wherein R is a linear, alkyl hydrocarbon having an average of 6 to 10 carbon atoms, R' and R" are each linear alkylhydrocarbons ~ of about 1 to 4 carbon atoms, x is an integer from 1 to 6, y i~
an integer from 4 to 15 and z is an integer from 4 to 25. A par-ticularly preferred example of this category is sold under the registered trademark of Poly-Tergent SLF-18 by the Olin Corporation, New Haven, Conn. Poly-Tergent SLF-18 has a composi-tion of the above formula where R is a C6-Clo linear alkyl mixture, R' and R" are methyl, x averages 3, y averages 12 and z averages 16. Another surfactant from this category has the for mula Cg_loo(cH2cH2o)7~8l(cH2c~o)H
14.45 c~3 (c) polyoxyethylene or polyoxypropylene condensates or alkyl phenols, whether linear-or branched-chain and unsaturated -14- c6078 or saturated, containing from about 6 to about 12 carbon atom~
and incorporating from about 5 to about 25 moles of ethylene oxide or propylene oxide.

(d) polyoxyethylene derivatives of sorbitan mono-, di-, and tri-fatty acid esters wher,ein the fatty acid component has between 12 and 24 carbon atoms. The preferred polyoxyethylene derivatives are of sorbitan monolaurate, sorbitan trilaurate, sorbitan monopalmitate, sorbitan tripalmitate, so~bitan monostearate, sorbitan monoisostearate, sorbitan tristearate, sorbitan monooleate, and sorbitan trioleate. The polyoxyethylene chains may contain between about 4 and 30 ethylene oxide units, preferably about 20. The sorbitan ester derivatives contain 1, 2 or 3 polyoxyethylene chains dependent upon whether they are mono-, di-, or tri-acid esters.

(e) polyoxyethylene-polyoxypropylene block polymers hav-ing the formula:
HO(CH2CH2O)a(cH(cH3)cH2)b(cH2cH2O)cH

wherein a, b and c are integers reflecting the respective polyethylene oxide and polypropylene oxide blocks of said polymer. The polyoxyethylene component of the block polymer con-stitutes at least about 40% of the block polymer. The material preferably has a molecular weight of between about 2,000 and 10,000, more preferably from about 3,000 to about 6,000. These 20066~37 materials are well known in the art. They are available under the trademark "Pluronics", a product of BASF-Wyandotte Corporation.

Examples of other suitable surfactants includo low-foaming anionics such as dodecyl hydrogen phosphate, methyl napthalene sulfonate, sodium 2-acetamido-hexadecane-1-sulfonate and mixtures thereof. Preferred anionics include materials selected from the class of branched alkali metal mono- and di-Cg_l4 alkyl diphenyl oxide mono- and disulfonates and linear alkali metal mono- and di Cg_l4 alkyl diphenyl oxide mono- and -~ disulfonates. Mixtures of any of the foregoing surfactants or of surfactants from any of the enumerated categories may be used.
~ If desired, anti-foaming agents may be utilized as well.
Antifoaming agents typically include a hydrocarbon oil and/or a silicone oil or together with particles such as silica. Mono and distearyl acid phosphates are also preferred suds suppressors.

- Autodish products in accordance with the invention may include enzymes, in particular, protease, amylase and/or lipase.
Enzymes may be present at levels of from about 0.5 to 2% by ) 20 weight, preferably from 0.5 to 1.5%, especially 0.5 to 1%.

The compositions of the invention may also include clays at a level of from 0.1 to 60%, preferably from 0.5% to 25%, and most preferably from 0.5% to 5% by weight.

200~68'7 Other ingredients which may be present in minor amounts include, perfumes, antiredeposition agents, suds builders, dyes, pigments, foam control agents, anti-tarnish agents, 80il suspend-ing agents, other functional additives, and f illers in ~d~tlon5 to those mentioned above.

Laundry detergents according to the invention will include many of the same ingredients me~tioned in connection with the autodish compositions, as will be apparent to one of ordinary skill in the art.

O In general, the laundry detergents will include from lO to 70% by weight of surfactants selected from the group consist-ing of anionic, nonionic, cationic, zwitterionic and amphoteric surfactants, and from 5 to 60% of the builders selected from the group consisting of a) non-silicate-coated inorganic tripolyphosphates hydrated in accordance with the present inven-tion together with silicated alkali metal carbonate, bicarbonate or sesquicarbonate or silicated mixtures thereof with alkali metal sulfate or other nonphosphate, inorganic salts, b) silicated inorganic alkali metal salt selected from the group of ) 20 alkali metal and ammonium carbonate, bicarbonate and sesquicarbonate in accordance with the second aspects of the invention, and c) mixtures of (a) and (b) with each other and/or with other builders such as inorganic phosphates not prepared in accordance with the invention, non-silicate-coated carbonates, : . . - .. .

~:0()6fi87 crystalline and amorphous aluminosilicates, nitrilotriacetic acid and salts thereof, citric acid and saltR thereof, and other builders mentioned above. Generally, the total of a? and b) above will ranqe from S to 60%.

Enzymes, chlorine ble~ch, oxygen b~each, activator~ and catalysts, may be included in the amounts given above for autodish compositions. Other ingredients found in powdered laun-dry detergents may also be included.

In general, processes in accordance with the invention 0 for making automatic dishwashing or other compositions, such as laundry detergent compositions, comprise dry mixing of a non-silicate-coated alkali metal inorganic phosphate, preferably hydrated in accordance with the first aspect of the invention, with a silicated inorganic salt, preferably having the moisture levels of and/or prepared in accordance with the process of the second aspects of the invention.

Typically, the alkali metal or ammonium tripolyphosphate salt, e.g., sodium tripolyphosphate, will be subjected first to hydration by spraying water thereon to achieve at least 50% by )20 weight hydration, preferably at least 60%, especially at least 75%. Then the salt is agglomerated. The hydrated salt is sub-jected to conditioning, sizing, storage and then blending with a silicated inorganic salt, preferably one in accordance with the second aspects of the invention.

2006fi~7 Parallel to the inorganic phosphate processing will occur the processing of the silicated salt or ~alts. First, the salt or salt mixture (e.g., sodium carbonate plu8 sodium sulfate) is sprayed with an aqueous silicate solution (e.g., ~odium silicate) preferably having about 35 to about 50% solids.
Preferably the solution has a temperature of from 40 to 70C.
Optionally, the spraying solution may also include surfactant and other ingredients. The salts are agglomerated in, for example a Schugi or O'Brien agglomerator. Rolling drum agglomerators in general and pan agglomerators may also be used. Then the agglom-erate is conditioned by exposure to heated air, i.e., air heated to a temperature greater than 78F. Generally, the salt is heated such that its moisture content is at least 5%, preferably 6%, especially 7.5%. Preferably, the air i8 at a temperature so that the silicated salt attains a temperature in the range of 120 to 150F.

Powder temperatures of from 125 to 140F and treatment times of from 10 to 15 minutes are especially preferred. Ideally the agglomerate is exposed to the heated air for about 20 320 minutes. Preferably the conditioning occurs on a fluidized bed.
An oven may also be used. However, in the case of oven heating, treatment occurs for from 15 minutes to 1 hour at an oven temper-ature of from 140 to 180F. Preferably, treatment in the oven occurs at from 150 to 170F for from 20 to 40 minutes. 160F

temperatures are preferred. After the conditioning, the agglom-200~.6~7 erated salt is sized, stored and then blended, preferably with the hydrated phosphate.

Unless otherwise indicated, all percentage~ given hereir.
are by weight.

EXAMPLES

Example 1 - Phosphate Hydration The effect of the level of phosphate hydration in compo-sitions including phosphate and silicated soda ash was investi-gated using a Sears Kenmore Automatic Dishwasher. 1:1 mixtures (by weight) of silicated salt and sodium tripolyphosphate hydrated to various levels were used.

The silicated salt was prepared by placing the salt mix-ture in a Schugi agglomerator and spraying with aqueous ~ilicate solution. Two batches were prepared and they had mean particle sizes of 675 microns and 1100 microns, respectively. The compo-sition of the silicated ash mixture was as follows.

Parts Ash A Ash B

Soda ash (grade 100) 30.0 30.0 Sodium sulfate 11.8 11.8 Agueous silicate 2.4 ratio 19.11 19.11 (47.1% solids) Particle size (microns) 675 1100 An initial machine dishwashing test showed that the silicated ash mixture dispensed quite readily when tested alone. The rate of Z00~i687 dispensing of the 1:1 mixture depended on the level of hydration of the phosphate. The product containing anhydrous pho~phate showed a sizeable amount of residue in the cup at the end of the wash. When the level of phosphate hydration exceeded 60 porc~nt, the product's dispensing was clearly acceptable. The re~ult~ fGr mixtures with silicated ash A are given in Table IA and the results for silicated ash B are given in Table IB.

/

2~06fi~3`7 Table lA: Dispenser Cakinq test Silicated Ash and TPP Hydrate Mixtures i Silicated Ash - 10067 PP
TPP Hydrate - Monsanto Dense Lot 95 Mixture Wt. - 45-50 grams (1:1) % Product Removal After Time (secs) 5 10 15 20 30 60_120 End % Hydration of TPP

0 .10 15 15 15 15 2020 40 TPP denotes sodium tripolyphosphate.
-Table lB: Dispenser Caking Test Silicated Ash ~ TPP Hydrate Mixtures % Product Removal After Time (secs) 5 10 15 20 30 60 120 End % Hydration of TPP !

) 31 35 35 35 35 35 40 50 80 Z00668~
-.. . . .. _ . , Example 2-Fluid Bed Drying of Silicated Ash Mixtures Two samples. of agglomerated silicated ash were prepared, one using a Schugi agglomerator (mean particle ~ize o~ th- pa~S1~
equaled 1400 microns) and the other in the laboratory u8in~ a blender (675 micron particles resulted). The agglomerates were conditioned on an Aeromatic fluid bed. The moisture levels and solubilities of samples prepared at various temperatures were measured. The sample prepared usin~ the Schugi agglomerator was initially conditioned whereas the laboratory samples were not, ~o 0 the results are not ~uite comparable. The results are given in Tables 2A and 2B. Solubility is rated on a scale of 0 to 5, with 0 being no residue and 5 heavyjresidue. The data show that higher levels of insolubles are formed as the powder temperature and residence times are increased.
~j 2006fi87 Table 2A: Fluid 8ed Drying Expt.
Silicated Ash (Laboratory Samples) Product weight = 1 kg Fluid Bed Cond. X H20 vl~
Powder Temp. LOB~ at:
Mins. Setting ~C F 70~C 135~C ~ol.
7L 10 80 49 120 7.9 11.2 0 " 52 126 5.2 8.7 0 " 58 136 4.2 7.1 0 " 60 140 2.2 5.2 0 7L-1 10 90 50 122 7.2 9.8 0 " - 58 137 4.4 6.8 0 " 65 149 2.8 5.3 0.25 " 65 14~ 1.8 3.7 2 " 70 158 1.0 2.8 2.5 7L-1 10 100 56 133 6.7 9.0 0 " 62 144 3.5 5.2 0.5 " 70 158 1.7 5.2 1.5 " 70 158 0.7 2.3 3 " 70 158 0.3 1.8 4 The readings at 70C and 135C are taken as indications of the amounts of free and total moisture, respectively.
Solubility: 0 = No residue, 5 = Heavy residue 200668t7 Table 2B: Fluid Bed ~rying Expt.
Silicated Ash (Schugi Samples) Product Wt. = 1 kg Code Fluid Bed Cond. % H2O via Powder Temp. Los~ ~t:
Mins. Setting C F 70C 135~C ~ol.
10067PP10 60 44 112 8.2 12.9 0 122 7.8 12.3 0 S0 122 7.2 10.3 0 56 133 8.6 12.6 0 58 137 7.2 10.8 140 3.0 6.0 2-3 100 52 126 7.2 12.6 0-1 100 60 140 6.5 11.6 100 62 144 5.0 10.3 1-2 100 62 144 4.7 9.4 2-3 100 70 158 4.0 7.2 2-3 Initial H2O Loss @ 70C = 10.0 Loss @ 135C = 14.0 Example 3 - Oven Drying Silicated ash samples which were conditioned via the oven method showed similar results to the samples that were conditioned using the f~luid bed method, i.e., higher levels of insolubles were formed when the powder tempeature and residence time were increased. The results are given in Table 3.

- - . - - . -200668~

Table 3 Parts Composition Soda Ash (Grade 100) Sodium Sulfate 12 Ru Silicate 2.4 r (47.1 % by weight solids) 21.23 Oven Drying Data Oven Temp. (C/F) 70/158 100/212 135/275 Initial H20 (K.~.) 11.7 11.7 11.7 K.~. denotes Rarl Fisher moisture analysis % H20/Solubility After 15 ~ s. ~ 1.0 2.25 30 " 8.1 0 3.0 0.25 0.7 3.0 60 " 7.2 0.25 1.6 - 0.4 3.5 90 " 5.4 1.0 1.1 3.0 - 5.S
2 hrs. 3.9 2.0 1.0 - - -3.25 hrs. 3.2 5.0 - 3.25 - -~ Example 4 The automatic dishwashing composition of Table 4 was blended using premixes of silicated soda ash and STPP which is hydrated to greater than 80% by weight. The silicated soda ash premix was prepared ~ith a Schugi agglomerator while the hydrated STPP pre-mix was prepared with a continuous O'Brien agglomerator.
-~ 20 Nonionic ~as post added to the STPP premix. After six months of storage the product and two premixes showed excellent solubility ratings even for the high temperature conditions. These results were surprisingly better than typical storage data obtained on currently marketed products. Storage data are given in Table 5.

-26- c6078 Z00668'7 Typical storage results for a currently marketed automatic dish-washer detergent (ADD) made via agglomeration are shown in Table 6.

Table 4 "Dry Blended" Formulation - ADD 0149 Soda Ash 20.0~ .
Sodium Sulfate 25.5 ~ AGG 37 (Soda As~ Premix A) Ru silicate 2.4r 9.0 (47.1% sol ids ) STPP (granular)32.0? Phosphate Premix B
Nonionic 2.5 Water 11.OJ

' - .

20~fifi~t7 Table 5 Storage Data for Formulation of Table 4 and Premixes 8.lP Finished Phosphate Soda Ash Product Premix B Pr~mlx ( A

Initial values:
Solubility 0 0-1/0 0 Storage Sol. Flow Sol. Flow Sol. Flow 2 Wee~s - RT 0 ff 0 - ff ff 80/80 0 " 0 " 0 "
95/50 0 " 0 " _ _ 125F 0 " 0 " 0 fr. ck.
1 Month - RT 0 ff 0 ff 0 ff ) 80/80 0 " 0-1 " 0 n 95/50 0 " 0 " _ _ 125F 0 " 0 " 0-1 fr. ck.
- 2 Months - RT 0 ff 0 ff 0 ff 80/80 0 " ~- 2/1 " 0 fr . ck.
(1/2 pkg) 125F 0 1/4 box fr. ck. 0 n 0 fr. ck.
3 Months - RT 0 ff 0 ff 0 ff 80/80 0 " 0 " 0 fr. ck.
- (1/2 pkg) 95/50 0 " 0 "
125F 1 " 1 " 0 fr. ck.
6 Months - RT 0 ff 0 ff 0 fr. ck.
2 0 80/80 0 n 0 n 0 n 95/50 0 " 0-1 "
) 125 F 1-2 " 0-1 " 0 RT = room temperature aff = free flowing bfr; ck. = friable caking -28- c6078

Claims

1. A composition comprising a) at least 10% by weight of a non-silicate-coated alkali metal or ammonium tripolyphosphate salt hydrated to at 1 about 50% by weight, and b) at least 10% by weight of an inorganic salt selected from the group consisting of i)alkali metal and ammonium carbonate, bicarbonate and sesquicarbonate and mixtures thereof and ii) mixtures thereof with alkali metal and ammo-nium chloride or sulfate at a weight ratio of from 10:1 to 1:10 wherein the inorganic salt is prepared by admixing with aqueous alkali metal silicate liquid.

2. The composition of claim 1 wherein the weight ratio of silicated inorganic salt to phosphate salt hydrated to at least 50% is about 70:30 or less.

3. The composition of claim 1 wherein the alkali metal phosphate sale is sodium tripolyphosphate.

4. The composition of claim 1 wherein the alkali metal carbonate is sodium carbonate.

5. The composition of claim 1 wherein the alkali metal sulfate is sodium sulfate.

6. The composition of claim 1 wherein the alkali metal silicate is sodium silicate.

7. The composition of claim 1 wherein the alkali metal tripolyphosphate is hydrated to at least 60% by weiqht.

8. The composition of claim 1 wherein the alkali metal tripolyphosphate is hydrated to at least 75% by weight.

9. The composition of claim 1 further comprising from 0.5 to 70%
by weight of a surfactant selected from the group consisting of anionic, nonionic, cationic, zwitterionic and amphoteric surfac-tants and mixtures thereof.

10. A process for preparing a composition comprising mixing a non-silicate containing alkali metal tripolyphosphate salt hydrated to at least 50% by weight with a silicated alkali metal or ammonium carbonate, bicarbonate or sesquicarbonate or silicated mixture thereof with alkali metal or ammonium sulfate or chloride or with borax.

11. A process for preparing a non-phosphate, inorganic carbonate, bicarbonate or sesquicarbonate salt agglomerated with aqueous alkali metal silicate solution which comprises:

a) in the substantial absence of phosphate salts, admixing the non-phosphate inorganic salt with an alkali metal sili-cate solution having a temperature within the range of 104°F
to 158°F, and b) conditioning the silicated salt with heated air so that the silicated salt has a moisture content by weight of at least 5%.

12. The process of claim 11 wherein the silicated salt is exposed to heated air so that the silicated salt has a moisture content by weight of at least 6%.

13. The process of claim 12 wherein the silicated salt is exposed to heated air so that the silicated salt has a moisture content by weight of at least 7.5%.

14. The process of claim 11 wherein the salt is alkali metal carbonate.

15. The process of claim 11 wherein the salt is a mixture of alkali metal carbonate and alkali metal sulfate.

16. A process for preparing a non-phosphate inorganic salt agglomerated with alkali metal silicate which comprises:

a) in the substantial absence of phosphate salts, admixing a non-phosphate inorganic salt selected from the group consisting of alkali metal or ammonium carbonate, bicarbonate or sesquicarbonate with an aqueous solution of alkali metal silicate and b) conditioning the silicated salt by exposure to air heated for a period of from 5 to 25 minutes such that the temperature of the powder reaches at least 120°F and does not exceed 150°F during the period.

17. The process of claim 16 wherein a temperature of the silicated salt of within the range of between 125 and 140°F is reached during the period.

18. The process of claim 17 wherein the temperature of the silicated salt reaches approximately 140°F and the silicated salt is exposed to the heated air for approximately 20 minutes.

19. The process of claim 16 wherein the salt is alkali metal carbonate.

20. The process of claim 16 wherein the salt is a mixture of alkali metal carbonate and alkali metal sulfate.

21. A composition comprising a) at least 10% by weight of a non-silicate-treated alkali metal phosphate salt, and b) at least 10% of a silicated non-phosphate inorganic salt selected from the group consisting of alkali metal and ammonium carbonates, bicarbonates, and sesquicarbonates and mixtures thereof having a moisture content of at least 5%.

22. The composition of claim 21 wherein the silicated inorganic salt has a moisture content of at least 6%.

23. The composition of claim 21 wherein the silicated inorganic salt has a moisture content of at least 7.5%.

24. The composition of claim 21 wherein the alkali metal phosphate salt is a tripolyphosphate .

25. The composition of claim 21 wherein the inorganic salt is selected from the group consisting of alkali metal carbonate and mixtures thereof with alkali metal sulfate.

26. The composition of claim 21 wherein the phosphate is alkali metal tripolyphosphate and is hydrated to at least 50% by weight.

27. The composition of claim 21 wherein the phosphate is hydrated to at least 60% by weight.

28. The composition of claim 21 wherein the phosphate is hydrated to at least 75% by weight.

29. The composition of claim 21 wherein the weight ratio of silicated salt to hydrated phosphate is not greater than 70:30.

30. The composition of claim 21 further comprising from 0.5-70% by weight of a surfactant selected from the group consisting of anionic, nonionic, cationic, amphoteric and zwitterionic surfactants and mixtures thereof.

31. A composition comprising a) at least 10% by weight of a non-silicate-treated inorganic alkali metal phosphate salt, and b) at least 10% by weight of a silicated inorganic non-phosphate salt prepared by i) agglomerating the inorganic salt with an aqueous sodium silicate solution and ii) conditioning the resulting agglomerate by exposure to heated air for a period of from 5 to 25 minutes and that the powder temperature reaches at least 120°F but does not exceed 150°F during that period.

32. The composition of claim 31 wherein the agglomerate reaches a powder temperature within the range of from 125 to 140°F during the period.

33. The composition of claim 32 wherein the agglomerate is exposed to the heated air for about 20 minutes.

34. The composition of claim 32 wherein the phosphate salt is an alkali metal or ammonium tripolyphosphate and is hydrated to at least 50% by weight.

35. The composition of claim 31 wherein the phosphate salt is an alkali metal or ammonium tripolyphosphate and is hydrated to at least 60% by weight.

36. The composition of claim 31 wherein the phosphate salt is hydrated to at least 75% by weight.

37. The composition of claim 31 wherein the inorganic salt is selected from the group consisting of alkali metal carbonates and mixtures thereof with alkali metal sulfates.

38. The composition of claim 31 further comprising from 0.5 to 70% by weight of a surfactant selected from the group consisting of anionic, nonionic, cationic, zwitterionic and amphoteric surfactants and mixtures thereof.

39. The composition of claim 31 wherein the inorganic salt is conditioned on a fluidized bed.

40. The process according to claim 11 wherein the inorganic salt is conditioned on a fluidized bed.

41. The process according to claim 16 wherein the inorganic salt is conditioned on a fluidized bed.

42. A composition comprising a) at least 10% by weight of a non-silicate-treated inorganic alkali metal phosphate salt, and b) at least 10% by weight of a silicated, inorganic nonphosphate salt prepared by i) agglomerating the inorganic salt with an aqueous sodium silicate solution, and ii) conditioning the resulting agglomerate by heating in an oven for a period of from 15 minutes to an hour such that the oven temperature reaches at least 140°F and does not exceed 180°F during that period.

43. The composition of claim 42 wherein the temperature reaches 150°F and does not exceed 170°F and the period is from 20 to 40 minutes.

44. Process of preparing a silicated inorganic salt comprising:

a) in the substantial absence of phosphate salts, admixing a non-phosphate, inorganic salt selected from the group consisting of alkali metal and ammonium carbonate, bicarbonate and sesquicarbonates with an alkali metal silicate solution having a temperature within the range of 104°F to 158°F, and b) conditioning the silicated salt by heating in an oven for from 15 minutes to one hour so that the oven temperature reaches at least 140°F but does not exceed 180°F.

45. Process of claim 11 wherein the silicated salt is conditioned such that it has a moisture content of no greater than 12% by weight.

46. Process of claim 13 wherein the silicated salt is conditioned such that the silicated salt has moisture content of no greater than 12% by weight.

47. The process according to claim 21 wherein the silicated salt is conditioned such that it has a moisture content of no greater than 12% by weight.