CA1244740A

CA1244740A - Granular automatic dishwasher detergent compositions

Info

Publication number: CA1244740A
Application number: CA000485878A
Authority: CA
Inventors: William A. Cilley
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1984-08-31
Filing date: 1985-06-28
Publication date: 1988-11-15
Also published as: GB2163769A; GB8519635D0

Abstract

GRANULAR AUTOMATIC DISHWASHER DETERGENT COMPOSITION
Abstract of the Disclosure Granular detergent compositions suitable for use in automatic dishwashing machines are disclosed. The compositions contain detergency builder materials, a chlorine bleach component, a low-foaming nonionic surfactant compatible with the bleach and suds control components comprising an alkyl phosphate ester and a source of calcium ions.

Description

~Z~47~0 GRANULAR AUTOMATIC DISHWASHER DETERC;ENT COMPOSITION
William A. Cilley BACKGP~OUN ~F THE INVENTION
Field of the Invention This invention relates to detergent compositions which are 5 particularly suitable for use in automatic dishwashers. Such compositions are normally alkaline and contain detergency builder materials, relatively low levels of low sudsing surfactants and a source of available chlorine.
SUMMARY OF THE INVENTION
-This invention is based on modifications in conventional, automatic dishwasher detergent compositions that provide surpris-ingly effective cleaning and absence of spotting and filming while maintaining an acceptably low level of sudsing. In particular the invention relates to automatic dishwasher detergent compositions 15 containing a chlorine bleach ingredient, a surfactant compatible with said bleach ingredient and effective suds control components for said surfactant which comprise:
(1 ) from about 20% to about 959~, preferably from about 40%
to about 90%, by weight of a detergency builder materi-al or mixtures thereof on an anhydrous basis;

(2) a chlorine bleach ingredient to provide from about 0.596 to about 5%, preferably from about 1~ to about 8Pg, of available chlorine based on the weight of the detergent composition:
l3) from about t% to about 15%, preferably from about 2% to about 89~, of a low foaming, nonionic ~urfactant which is solid at 35C (95F), preferably an ethoxylated nonionic surfactant derived from the reaction of a monohydroxy alcohol or alkylphenol in which the alkyl ~roup contains from about 8 to about 20 carbon atoms, excluding cyclic carbon atoms, with from about 6 to about 15 moles of ethylene oxide per mole of alcohol or alkylphenol on an average basis;
(4~ from about 1~ to about 50%, preferably from about 2~ to about 20%, based on the weight of the nonionic . ~ ,.

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surfactant, of alkyl phosphate ester or mixtures there-of, preferably mono C18 aikyl phosphate esters and/or di C18 alkyl phosphate esters; and (5) a water-soluble or water-solubilizable calcium-containing material to provide at least about 25~ by weight of the calcium ions which will react with said alkyl phosphate ester to form a more effective suds suppressor.
-- DETAILED DESCRIPTI()N OF THE INVENTION
.
Deteraencv Builder ~laterial , ., _ Compositions of the invention contain from about 20% to about 9596, preferably from about 40~ to about 90%, by weight of a deter-gency builder component or mixtures thereof on an anhydrous basis.
The detergency builder material can be any of the detergent l 5 builder materials known in the art which include trisodium phos-phate, tetrasodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, sodium silicates having SiO2: Na2O
weight ratios of from about 1:1 to about 3.6:1, sodium carbonate, sodium hydroxide, sodium sitrate, borax, sodium ethylenediamine-tetraacetate, sodium nitrilotriacetate, sodium carboxymethyloxy-succinate, sodium carboxymethyloxymalonate, polyphosphonates, polymeric carboxylates such as polyacrylates, and mixtures there-of. Preferably, monomeric organk detergency builder materials comprise not more than about 10% of the composition by weight.
Preferred detergency builder materials have the ability to remove metal ions other than alkali metal ions ~rom washing 50-lutions by sequestration, which as defined herein includes chelation, or by precipitation reactions. Sodium tripolyphosphate is a particularly preferred detergency builder material which is a sequestering agent. Sodium carbonate is a preferred precipitation detergency builder, particularly when it is desirable to reduce the total phosphorus level of the compositions of the invention.
Chlorinated trisodium orthophosphate can act as both a chlorine bleach and a precipitation detergency builder material.

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The inclusion of water-soluble silicates, especially sodium silicates having SiO2: Na2O weight ratios of from about 1:1 to about 3.6:1 is a particularly preferred embodiment of the invention. Such silicates are a source of aikalinity useful in the 5 automatic dishwashing process and also act to inhibit the corro-sion of aluminum, ~31assware and ceramic glazes.
Particularly preferred compositions of the invention contain from about 15% to about 50% sodium tripolyphosphate, from about 5% to about 4096 of sodium silicate solids as described hereinbefore 10 and from 0% to about 25~ sodium carbonate by weight.
Chlorine Bleach Component The compositions of the invention can contain a chlorine bleach ingredient to provide from about 0. 596 to about 5~6, preferably from about 1 . 0% to about 3%, of available chlorine 15 based on the weight of the detergent composition.
An inorganic chlorine bleach ingredient such as chlorinated trisodium phosphate can be utilized, but organic chlorine bleaches such as the chlorocyanurates are preferred. ~IVater-soluble di-chlorocyanurates such as sodium or potassium dichloroisocyanurate 20 dihydrate are particulariy preferred.
Methods of determining "available chlorine" of compositions incorporating chlorine bleach materials such as hypochlorites and chlorocyanurates are well known in the art. Available chlorine is the chlorine which can be liberated by acidification of a solution 25 of hypochlorite ions (or a material that can form hypochlorite ions in solution) and at least a molar equivalent amount of chloride ions. A conventional analytical method of determining available chlorine is addition of an excess of an iodide salt and titration of the liberated free iodine with a reducing agent.
30 The Nonionic Surfactant The compositions of the invention contain from about 19g to about 15%, preferably from about 2~ to about 8~, of a nonionic surfactant. In a preferred embodiment the surfactant is an ethoxylated surfactant derived form the reaction of a monohy-35 droxy alcohol or alkylphenol containing from about ~ to about 20 ~;~4~74C) carbon atoms, excluding cyclic carbon atoms, with from about 6 to about 15 moles of ethylene oxide per mole of alcohol or alkyl-phenol on an average basis.
A particularly preferred ethoxylated nonionic surfactant is derived from a straight chain C16 20 alcohol, preferably a C18 alcohol, condensed with an average of from about 6 to about 15 moles, preferably from about 7 to about 12 moles, and most - preferably from about 8 to about 9 moles of ethylene oxide per mole of aicohol. Preferably the ethoxylated nonionic surfactant so ~derived has a narrow ethoxylate distribution relative to the average .
The ethoxylated nonionic surfactant can optionaily contain propylene oxide in an amount up to about 15~ by weight of the surfactant and retain the advantages hereinafter described.
Preferred surfactants of the invention can be prepared by the processes described in U . S . Patent 4, ~23 ,163, issued September 16, 1980, Guilloty, The preferred surfactants of the invention in combination with the other components of the composition provide excellent cleaning and outstanding performance from the standpoints of absence of residual spotting and filming. In these respects, the preferred surfactants of the invention provide generally superior performance relative to ethoxylated nonionic surfactants with hydrophobic groups other than monohydroxy alcohols and alkyl-phenols, for example, polypropylene oxide or polypropylene oxide in combination with diols, triols and other polyglycols or diami nes .
The surfactants of the invention are those that can be incor-porated in compositions containing alkali metal dichlorocyanurates or other organic chlorine bleaches without an interaction that results in loss of available chlorine. The nature of this problem is disclosed in U.S. Patent 4,309,299 issued January 5, 1982 to Rapisarda et al and in U.S. Patent 3,359,207, issued December 19, 1967, to Kaneko et al, ~az~47gc~

As disclosed herein, the surfactants of the invention require suds control components for utility in the compositions of the invention .
Alkyl Phosphate Ester The compositions of the invention contain from about 1~ to about 5096, preferably from about 2~ to about 20%, based on the weight of ethoxylated nonionic surfactant of alkyl phosphate ester or mixtures thereof.
Suitable alkyl phosphate esters are disclosed in U . S. Patent

3,314,891, issued April t8, 1967, to Schmolka et al~

The preferred alkyl phosphate esters contain from 16-20 carbon atoms. Highly preferred alkyl phosphate esters are monostearyl acid phosphate and monooleyl acid phosphate, or salts 15 thereof, particularly alkali metal salts, or mixtures thereof.
The alkyl phosphate esters of the invention have been used to reduce the sudsing of detergent compositions suitable for use in automatic dishwashing machines. The esters are particularly effective for reducing the su~sing of compositions comprising 20 nonionic surfactants which are heteric ethoxylated-propoxylated or block polymers of ethylene oxide and propylene oxide.
Sudsing of the ethoxylated monohydroxy alcohol or alkyl-phenol nonionics of the present invention is reduced by incor-poration of the alkyl phosphate esters of the invention, but not 25 always sufficiently to prevent a suds overflow or to maintain optimum spray arm speeds under a wide variety of soils, product usage levels, machine types and water conditions.
a!cium-Containin~ Nlaterial The compositions of the invention contain a water-soluble or 30 water-solubilizable calcium-containing material to provide from about . 25 to about 2 . 5 moles, pre~erably from about . 5 to about .5 moles per mole of the alkyl phosphate ester present.
A source of available calcium ions is necessary for consistent control of sudsing in the compositions of the invention. The 35 compositions of the invention incorporate a calcium containing ~L~4~7~

material because calcium from the water supply and soi l is not necessarily sufficient, particularly when a household has a wa-ter-softening unit incorporated in the plumbing.
Convenient calcium-containing materials are the water-soluble salts of calcium such as preferred calcium chloride, calcium acetate, calcium bromide, etc. The calcium-containing material may comprise a calcium salt of components which are otherwise --- essential when incorporated as alkali metal or other monovalent cation salts. Preferably, however, the alkyl phosphate ester should not be totally or even partially present in the composition as a calcium salt. While not wishing to be bound by the theory, it is believed that the in-situ formation of the calcium salts of the alkyl phosphate ester during the washing process constitutes the mechanism by which superior suds control is obtained in the compositions of the invention.
Optional Ingredients China protecting agents including soluble zinc and aluminum salts, aluminosilicates, aluminates, etc., can be present in amounts of from about 0.1% to about 5%, preferably from about 0.5% to about 2~.
Filler materials can also be present including sucrose, sucrose esters, sodium chloride, sodium sulfate, etc., in amsunts from about 0.001% to about 60%, preferably from about 5% to about 3096.
~5 Hydrotrope materials such as sodium benzene sulfonate, sodium toluene sulfonate, sodium cumene sulfonate, etc., can be present in minor amounts.
Dyes, perfumes, crystal modifiers and the like can also be added in minor amounts.
The compositions of the invention can be prepared in any manner that results in formation of a granular product form. The process described in U.S. Patent 2,895,916 issued July 21, 1959, to Milenkevich et al, and variations thereof, are particularly suiiable. Also particularly suitable is the process described in 3~ U.S. Patent 4,~27,417, issued January 24, 1984 to Porasik.

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As used herein, all percentages, parts and ratios are by weight unless otherwise stated.
The following Examples illustrate the invention and facilitate its understanding.
EXAMPLE I
A. 33.1 Parts by weight of powdered anhydrous sodium tripoly-phosphate and 8 . 0 parts by weight of hydrous sodium silicate (82% solids, SiO2:Na2O weight ratio of 2.4) were added to a ribbon mixer. With the mixer in operation the following ingredi-ents were àdded during a cycle time of 180 seconds.
(a) from 0 seconds to 165 seconds A blend of 13,8 parts of an aqueous sodium silicate so-lution containing 47.3% silicate solids with a SiO2: Na2O
weight ratio of 2,0 and 4.7 parts of an aqueous sodium silicate solution containing 37.5~ silicate solids with a SiO2: Na2O weight ratio of 3 . 2 was added as a spray .
This blend also contained minor amounts of perfume and dye .
(b) at 60 seconds 19 . 4 Parts of sodium sulfate and 10 . 0 parts of sodium carbonate were added dry.
~c) from 60 seconds to 165 seconds

4.0 Parts of a polyoxyalkylene nonionic surfactant (con-densation product of C1 8 alcohol with average of 8. 25 moles ethylene oxide) and 0.2 parts of monostearyl acid phosphate were added as a spray.
~d) at 145 seconds

5.0 Parts of sodium chloride having a particle size such that at least 80~ passed through a 100 Tyler mesh screen were added dry.
(el after 180 seconds ~roduct was discharged from mixer.
(f) 2 . 5 Parts of sodium dichlorocyanurate dihydra~e was added and mixed in after product discharged from the mixer at step e) was dried to a water content of about tO per cent and aged for about 24 hours.

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B. The process of A is repeated with the addition of 0.14 parts CaCI2 incorporated in the aqueous sodium silicate solution of step (a) .
Water lost during processing accounts for any excess over lO0 parts in the Compositions A and B.

Detergent compositions were prepared according to Example I
A were tested with varying levels of the surfactant and monostearyl acid phosphate. The CaC12 was added either by dry 10 mixing, or in the suds generator. The suds volume was measured by use of a laboratory suds generator consisting of a graduated cylinder modified to allow connection of a take-off tube through the side wall at the bottom, a small pump, tubing and a pipette tip nozzle. Solution flows out the bottom of the cylinder, 15 through the pump and is squirted through the nozzle onto the top of the water column, generating suds according to a pre-deter-mined flow rate.
Testing done at 130F, 096 hardness.
g6 MSAP % SurfactantSuds Volume ~ml) o 1 110 .2 1 35 ~5 2 200 EXAMPLE l l I
A detergent composition was prepared according to Example I A.
30 Varying levels of CaCI2 ' 2H20 were added, and the suds volume was measured by use of a suds generator.

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% CaCI2 2H2Suds Volume (n l) 0.1 90 0.2 80 0.3 70 0.4 55 0.5 ~0 0.6 ~6 t(~ 0.7 46 0.8 48 0.9 50 1.0 50 EXAMPLE IV
A composition was prepared according to Example I A, and varying percentages of CaCI2 ' 2H2OIMSAP (in t :1 concentrations) were separately added. Suds measurements were made at 1 30F . There was no hardness present prior to addition of the CaC12 and MSAP.
96 CaC12 ' 2H20/MSAP Suds Volume (ml) o 0.1 220 0.2 80 0,3 55 0.4 0.5 32 0.6 30 WHAT IS CLAIMED IS:

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A low sudsing granular detergent composition suitable for use in an automatic dishwashing machine comprising on an anhydrous basis:
(a) from about 20% to about 95% by weight of a detergency builder material or mixtures thereof;
(b) a chlorine bleach ingredient to provide from about .5%
to about 5% of available chlorine based on the weight of the detergent composition;
(c) from about 1% to about 15% of a low-foaming nonionic surfactant which is solid at 35°C (95°F).
(d) from about 5% to about 50%, based on the weight of the ethoxylated nonionic surfactant of an alkyl phosphate ester or mixtures thereof;
(e) from about . 25 moles to about 2 . 5 moles of a water soluble or water solubilizable calcium containing material per mole of alkyl phosphate ester present.

2. The composition of Claim 1 wherein said calcium containing material comprises a water soluble calcium salt.

3. The composition of Claim 1 wherein said water-soluble calcium salt is calcium chloride.

4. The composition of Claim 1 wherein said alkyl phosphate ester comprises an alkyl phosphate ester or diester containing from about 16 to about 20 carbon atoms or the monovalent salts thereof, or mixtures thereof.

5. The composition of Claim 4 wherein said calcium containing material comprises a water-soluble calcium salt.

6. The composition of Claim 4 wherein said water-soluble calcium salt is calcium chloride.

7. A low sudsing granular detergent compositlon suitable for use in an automatic dishwashing machine comprising:
(a) from about 40% to about 90% by weight of a detergency builder material, or mixtures thereof;
(b) an organic chlorine bleach component to provide from about 1% to about 3% of available chlorine based on the weight of the detergent composition;
(c) from about 2% to about 8% of an ethoxylated surfactant derived from the reaction of a monohydroxy alcohol or alkylphenol containing from about 8 to about 20 carbon atoms, exclusive of cyclic carbon atoms with from about 6 to about 15 moles of ethylene oxide per mole of alco-hol or alkylphenol on an average basis.
(d) from about 5% to about 20% based on the weight of the ethoxylated nonionic surfactant of an alkyl phosphate ester selected from the group comprising mono C18 alkyl acid phosphate, a mixture of mono C18 alkyl acid phos-phate and di-C18 alkyl acid phosphate, and hydrates thereof and mixtures thereof;
(e) from about 0.5 moles to about 1.5 moles of water-soluble calcium salt per mole of alkyl phosphate ester present.

8. The composition of Claim 7 wherein the said ethoxylated nonionic surfactant comprises a surfactant derived from a straight chain alcohol contains from about 16 to about 20 carbon atoms exclusive of cyclic carbon atoms condensed with an average of from about 7 to about 12 moles of ethylene oxide per mole of said alcohol.

9. The composition of Claim 7 wherein the said ethoxylated nonionic surfactant comprises a surfactant derived from a straight chain C18 condensed with an average from about 7 to about 9 moles of ethylene oxide per mole of said alcohol.

10. The composition of Claim 8 wherein the detergency builder material or mixtures thereof comprise the material selected from the group consisting of sodium tripolyphosphate, sodium carbonate, sodium silicate and hydrates and mixtures thereof.

11. The composition of Claim 7 wherein the alkali metal dichlorocyanurate comprises sodium diisocyanurate dihydrate, potassium diisocyanurate dihydrate and mixtures thereof.

12. The composition of Claim 8 wherein the water-soluble calcium salt is calcium chloride.

13. The composition of Claim 7 wherein the detergency builder material or mixtures thereof comprise a material selected from the group consisting of sodium tripolyphosphate, sodium carbonate and sodium silicate and hydrates and mixtures thereof.

14. The composition of Claim 7 wherein the organic chlorine bleach ingredient is a sodium dichloroisocyanurate dihydrate potassium dichloroisocyanurate dihydrate and mixtures thereof.

15. The composition of Claim 7 wherein the water-soluble calcium salt is calcium chloride.