US3600317A

US3600317A - Noncaking dishwashing detergent

Info

Publication number: US3600317A
Application number: US6319A
Authority: US
Inventors: Anthony Ethelbert Lintner
Original assignee: Anthony Ethelbert Lintner
Current assignee: Calgon Corp
Priority date: 1970-01-27
Filing date: 1970-01-27
Publication date: 1971-08-17
Anticipated expiration: 1988-08-17

Abstract

A METHOD OF MAKING A CHEMICALLY STABLE DOMESTIC DISHWASHING DETERGENT IS DISCLOSED IN WHICH EXCELLENT CLEANING PROPERTIES ARE COMBINED WITH THE ABILITY TO RESIST CAKING BY THE CONTROLLED ADDITION OF, TYPICALLY, ABOUT 2% WATER TO ANHYDROUS SODIUM TRIPOLYPHOSPHATE.

Description

AU 1535 L 6 crates ratent 015cc 3,600,317 Patented Aug. 17, 1971 3,600,317 NONCAKING DISHWASHING DETERGENT Anthony Ethelbert Lintner, 920 Berkshire Ave., Pittsburgh, Pa. 15226 No Drawing. Continuation-impart of application Ser. No. 608,505, Jan. 11, 1967. This application Jan. 27, 1970,

Ser. No. 6,319

Int. Cl. Clld 7/56 US. Cl. 252-99 7 Claims ABSTRACT OF THE DISCLOSURE A method of making a chemically stable domestic dishwashing detergent is disclosed in which excellent cleaning properties are combined with the ability to resist caking by the controlled addition of, typically, about 2% water to anhydrous sodium tripolyphosphate.

RELATED CASES This is a continuation-in-part of my application of the same title, Ser. No. 608,505, filed Jan. 11, 1967, now abandoned.

BACKGROUND OF THE INVENTION This invention relates to detergents and methods of making them. More particularly, it relates to alkaline detergents intended for use in domestic dishwashing machines. The detergents of this invention are inhibited 30 against caking.

A common problem in the art of detergents for household dishwashing machines is that they tend to cake. Detergents which are generally in hydrated form, e.g.,

as an ingredient, tend to cake in the package particularly under elevated and variable temperature conditions and become difficult to remove and place in the dishwasher dispenser. Those which employ anhydrous ingredients such as anhydrous sodium tripolyphosphate have a great afiinity for water so that even a very short exposure to relatively small amount of water or a moist atmosphere at the beginning of the wash cycle may tend to cause cake formation (agglomeration) in the dispenser. As a result, the dispenser becomes clogged and unable to function as it should, while the detergent loses its free flowing and otherwise usually highly soluble characteristics. Compositions which employ hydrated ingredients have the additional disadvantages of marginal chlorine stability over long periods unde'r variable temperatures and a lower content of active ingredients per unit of weight.

Many attempts have been made to overcome the disadvantages of the hydrated and the anhydrous forms, but the problems still persist.

SUMMARY OF THE INVENTION I have found a method of combining more or less conventional mechanical dishwashing detergent ingredients in conventional mixing equipment by which a product is made having surprisingly beneficial properties with respect to hydration.

The more or less conventional ingredients used in my detergent composition are as follows:

Percent by weight 7 Preierred Ingredient concentration Range Anhy. sodium tripolyphosphate 53. 955 42-58. Aluminum acetate 1.0 0.5-2. Anhy. sodium metasilicat-e 16.0 12-25. Soda ash or trisodium orthophosphate 22. 920 -25. Potassium dichlorisocyauurate 1. 0 0.52.0 Low sudsing, nonionic wetting agent (100 percent active) 4. 0 1-5. 10 Water 1.080 0. 75-5. 0.

Dye (optional) 0.005 Up to 0.2. Perfume (optional) 0. 040 Up to 0.4.

The low sudsing nonionic wetting agents are well known in the art. Some of the better known ones are the Pluronic series of ethylene oxide-propylene oxide block polymers. We prefer to use alkyl aryl polyethers such as Triton CF-lO and amine polyglycol condensates such as Triton CF-32. Any of the low sudsing nonionic wet- 0 ting agents known-to be useful in mechanical dishwashing (see McCutcheons Detergents and Emulsifiers Annual, 1966) may be used. Combinations of such wetting agents are also of use.

A preferred low sudsing nonionic wetting agent is 5 Triton CF-lO," of the formula Surfactants which may be employed in the compositions of this invention are generally the polyoxyalkylene adducts of hydrophobic bases wherein the oxygen/carbon atom ratio in the oxyalkylene portion of the molecule is at least about 0.5. Those compositions which are condensed with hydrophobic bases to provide a polyoxyalkylene porthose which employ sodium tripolyphosphate hexahydrate tion having an Oxygen/Carbon atom ratio of at least 0- include ethylene oxide, butadiene dioxide and glycidol and the like. Ethylene oxide, for example, is condensed with the hydrophobic base in an amount suflicient to impart water solubility and surface active properties to the molecule being prepared. The exact amount of ethylene oxide condensed with the hydrophobic base will depend upon the chemical characteristics of the base employed and is readily apparent to those of ordinary skill in the art relating to the synthesis of oxyalkylene surfactant condensates.

Typical hydrophobic bases which can be condensed with ethylene oxide in order to prepare nonionic surface active agents include monoand polyalkyl phenols, polyoxypropylene condensed with a base having from about one to six carbon atoms and at least one reactive hydrogen atom,

fatty acids, fatty amines, fatty amides, alkyl mercaptans and fatty alcohols. The hydrocarbon ethers such as the benzyl or lower alkyl ether of the polyoxyethylene surfactant condensates are also advantageously employed in the compositions of the invention.

ene radical. The alkyl substituent on the aromatic nucleus may be octyl, diamyl, polymerized propylene such as propylene tetramer and trimer, isooctyl and nonyl. The benzyl ethers of the polyoxyethylene condensates of monoalkyl phenols impart good properties to the compositions of the invention. A typical product corresponds to the formula:

n-Q-ownmmmcmon where R is an alkyl group, and n is from about 5 to 30.

Other suitable water-soluble nonionic surfactants are cogeneric mixtures of conjugated polyoxyalkylene compounds containing in their structure at least one hydrophobic oxyalkylene chain in which the oxygen/carbon atom ratio does not exceed about 0.33 and at least one hydrophilic oxyalkylene chain in which the oxygen/carbon atom ratio is not less than about 0.5. Propylene oxide, butylene oxide, amylene oxide and styrene oxide are illustrative of oxyalkylene compounds having an oxygen/ carbon atom ratio not exceeding about 0.33 while ethylene oxide, butadiene dioxide and glycidol, as previously pointed out are illustrative of oxyalkylene compounds having an oxygen/carbon atom ratio of at least about 0.5. Although the hydrophobic chain has an oxygen/ carbon atom ratio not exceeding about 0.33, it is often advantageous to include in this chain a small amount of ethylene oxide, that is, up to about fifteen weight percent, and likewise in the hydrophilic chain which has an oxygen/ carbon atom ratio not less than about 0.5, it is often advantageous to include a small amount of propylene oxide or butylene oxide, that is, up to about fifteen weight percent, and the oxygen/carbon atom ratios described herein and in the claims are not intended to preclude such mixtures.

Among the conjugated polyoxyalkylene compounds which can be used in the compositions of the invention are those which correspond to the formula:

wherein Y is the residue of an organic compound having from about one to six carbon atoms and one reactive hydrogen atom, 11 has an average value of at least about 6.4 as determined by hydroxyl number and m has a value such that the oxyethylene portion constitutes about to 90 weight percent of the molecule. Most of the surface active agents are more particularly described in US. Pat. No. 2,677,700. They are sold under the trademark Pluronic.

Other conjugated polyoxyalkylene surface active agents which are most advantageously used in the compositions of the invention correspond to the formula:

wherein Y is the residue of an organic compound having from about two to six carbon atoms and containing x reactive hydrogen atoms in which x has a value of at least about two, n has a value such that the molecular weight of the polyoxypropylene hydrophobic base is at least about 900 and m has a value such that the oxyethylene content of the molecule is from about 10 to 90 weight percent. Compounds falling within the scope of the definition for Y include, for example, propylene glycol, glycerine, pentaerythritol, trimethylolpropane, ethylenediamine, triethylenetetramine, triisopropanolamine and butylamine. Where Y is ethylenediamine, the compounds may be represented by the formula:

H( :H4o)y( 3 6O):

N-Cm-CH N H(CIH4O)Y(C3HGO); 3H6Olx(CgH4O);H

wherein x and y are integers. Products of this type are sold under the trademark Tetronic. As already noted, the oxypropylene chains optionally, but advantageously, contain small amounts of ethylene oxide and the oxyethylene chains also optionally, but advantageously, contain small amounts of alkylene oxides having an oxygen/ carbon atom ratio of not more than about 0.33 such as propylene oxide and butylene oxide. Most of these compounds are more particularly described in US. Pat. Nos. 2,674,619 and 2,979,528.

Other suitable polyoxyethylene nonionic surface active agents are the ethylene oxide adducts of higher aliphatic alcohols having from about 8 to 22 carbon atoms in the aliphatic portion, and about 3 to 30 ethenoxy units in the oxyethylene portion. Typical products are blends of linear fatty alcohols containing an even number of carbon atoms condensed with about three to nineteen moles of ethylene oxide.

Other suitable nonionic surface active agents are the propylene oxide adducts of condensates of ethylene oxide and higher aliphatic alcohols having from about 8 to 22 carbon atoms in the aliphatic portion. Various ratios of ethylene oxide and propylene oxide may be used.

Other suitable nonionic surfactants are the products prepared by condensing a mixture of ethylene oxide and propylene oxide with aliphatic alcohols having from about 8 to 22 carbon atoms in the aliphatic portion of the alcohol. Various ratios of oxides may be employed.

Other suitable surface active agents are the polyoxyalkylene surface active agents having heteric polyoxyethylene solubilizing chains. These polyoxyalkylene compounds conform to the following generic formula:

wherein Y is the nucleus of an organic reactive hydrogen compound containing x reactive hydrogen atoms and having up to six, inclusive, carbon atoms, x is an integer, P is a hydrophobic polyoxyalkylene chain having an oxygen/carbon atom ratio of not more than 0.40, the molecular weight of P and the value of at being such that the molecule, excluding E, has a molecular weight of at least about 400 to 900 and up to about 25,000, and E is a hydrophilic heteric polyoxyalkylene chain which (1) contains oxyethylene groups and at least five percent by weight of higher molecular weight oxyalkylene groups having at least three carbon atoms in their structure, and (2) has an average oxygen/carbon atom ratio of greater than 0.40, E being present in the composition to the extent that it constitutes from 5 to 90 weight percent of the total composition. These compositions are more particularly described in US. Pat. No. 3,101,374. Mixtures of these compositions and fatty acid phosphates may also be used.

Any of the above surfactants may be referred to as low sudsing nonionic wetting agents.

An example of a suitable dye is Lanasyn Brilliant Green B.L., having the formula:

NMIMS Any of the common commercial detergent dyes and perfumes may be used. Pine fragrance oil is an acceptable perfume.

The sodium tripolyphosphate, which is anhydrous, should preferably have a particle size such that at least by weight of the particles pass through a U.S. screen number 20 and only about 5% will pass through a US. screen number 80. The amount of water used is always less than 10% of the weight of anhydrous sodium tripolyphosphate and preferably calculated to be about 7% of it. A preferred amount of the sodium tripolyphosphate is 54% by weight. The hydration step is carried out in a particular manner. The low sudsing nonionic wetting agents (typically Triton CF-32 or Triton CF-l O) are dissolved along with the optional dye and perfume in the water, which is then sprayed onto the sodium tripolyphosphate with continuous and simultaneous mixing or agitation. The surfaces of the granules of the sodium tripoly= phosphate are thus made immediately and evenly wet by the small quantity of water containing the wetting agents, dye and perfume. In this manner, a surface layer of sodium tripolyphosphate hexahydrate is formed on the granules of sodium tripolyphosphate, while the sodium tripolyphosphate in the interior of the granule remains in.

the anhydrous form. As the aqueous solution is added. the added water becomes part of the sodium tripolyphosphate molecule. The other ingredients are then added to the mixture and a free flowing, non-sticking. noncaking chemically stable product is formed. When the detergent is placed in the dishwasher dispenser, its major surface component, hydrated sodium tripolyphosphate, is no longer reactive to water because it is already hydrated and therefore does not readily absorb moisture which prematurely enters the dispenser. The major mechanism by which caking occurs is thus averted; e.g. formation of hydrate bridges is retarded.

Laboratory and field tests have shown that the incidence of caking of my new partially hydrated product is far less than that with an anhydrous product of similar composition.

I do not intend to be bound by the above specific examples and illustrations of my invention. It may be otherwise practiced within the scope of the following claims.

I claim:

1. Method of making a noncaking mechanical dishwashing composition comprising (a) preparing a premix consisting essentially of, in percent by weight, about 15% low sudsing nonionic wetting agent, about 0.755.0% water, and small amounts of dye and perfume, (b) spraying the premix onto about 42-58% anhydrous sodium tripolyphosphate having a particle size distribution such that no more than about 15% is retained on a US. screen number 20 and no more than about 5% is passed through a U.S. screen number 80, while agitating the sodium tripolyphosphate whereby the surface of the sodium tripolyphosphate particles is hydrated, and (c) mixing the hydrated sodium tripolyphosphate with about 0.52% aluminum acetate, about 12-25% sodium metasilicate anhydrous, about 20-25% of a compound of the group consisting of soda ash and trisodium orthophosphate and about 0.5-2.0% potassium dichloroisocyanurate, whereby a free flowing, noncaking product is obtained.

2. Composition made by the process of claim 1.

3. Method of claim 1 in which about 1.0% potassium dichloroisocyanurate is used.

4. Method of claim 1 in which about 16.0% anhydrous sodium metasilicate is used.

5. Method of claim 1 in which the low sudsing nonionic wetting agent is of the group consisting of ethylene oxide-propylene oxide block polymers and amine polyglycol condensates.

6. Method of claim 1 in which the water used is about 7% by weight of the anhydrous sodium tripolyphosphate.

7. Method of making a noncaking mechanical dishwashing composition comprising (a) preparing a premix consisting essentially of, by weight, about 4% low sudsing nonionic wetting agent, about 1.08% water, and small amounts of dye and perfume, (b) spraying the premix onto about 54% anhydrous sodium tripolyphosphate having a particle size distribution such that no more than about 15% is retained on a US. screen number 20 and no more than about 5% is passed through a US. screen number 80, While agitating the sodium tripolyphosphate whereby the surface of the sodium tripolyphosphate particles is hydrated, and (c) mixing the hydrated sodium tripolyphosphate with about 0.52% aluminum acetate, about 12-25% sodium metasilicate anhydrous, about 20- 25% soda ash or trisodium phosphate, and about 0.5- 20% potassium dichloroisocyanurate, whereby a free flowing, noncaking product is obtained.

References Cited UNITED STATES PATENTS 3,306,808 2/1967 Oberle 282-99 3,350,318 10/1967 Green 252-99X 3,359,207 12/1967 ,Kaneko et al. 2S299 3,361,675 1/1968 Fuchs et al 2S299 MAYER WEINBLATT, Primary Examiner UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,500,317 Dated August 17, 1971 Anthony Ethelbert Lintner Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, after line 4, insert assignor to Calgon Corporation, Pittsburgh, Pa.

Signed and sealed this 25th day of July 1972.

(SEAL) Attest:

EDWARD M. FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents RM PC4050 (L691 USCOMM-DC 60376-F'69 n U S GQVERNMENT PRH'TING OFFICE: I! -J-Jll