CA2031289A1 - Automatic dishwasher powder detergent composition - Google Patents

Abstract

AUTOMATIC DISHWASHER POWDER DETERGENT COMPOSITION

ABSTRACT OF THE DISCLOSURE

The application is directed to an automatic dishwasher powder detergent composition with improved anti-filming and anti-spotting properties and to a method of using the detergent composition. The detergent composition comprises silica anti-filming agent, a water soluble polyacrylate anti-spotting agent, inorganic builder salts, chlorine bleach and bleach-stable detergent. The compositions provide reduced filming and spotting on dishware, glassware, china and the like, particularly in hard water at low temperature. The powder compositions are dry, free flowing and are highly soluble and readily dispersed in the wash bath.

Description

~ ~ - ~ 2~031289 IR4 4 22 l ¦ AUTOMATIC DIS~IWASHER POWDER DETE~GENT COMPOSITION

RELATED APPLICATIONS
- - This application is a continuation-in-part of applicants' copending l applications Serial No. 323 ,138 filed March 13, 1989, Serial No. 323,126, ¦ ffled March 10, 1989, Serial No. 323,139, filed March 13, 1989 and Serial No, 323,137, filed Murch 13, 1989 all of which are directed to aqueous automatic dishwasher detergent compositions containing an anti-fflming agent or an anti-filming and anti-spotting agent.
¦ FIELD OF THE INVENTION
¦ The present invention relates to an automatic dishwasher detergent ¦ composition having improved snti-filming properties. The present invention ¦ is particularly directed to a stable dry powder detergent composition ¦ containing an anti-filming agent for use in an automatic dishwasher to clean ¦ dishware, glassware and the like.
¦ The present invention more particularly relates to a powder automatic ¦ dishwsshing detergent composition with improved anti-filming and ¦ anti-spotting properties and to a method of using the detergent composition to- clean dishware, glassware, china and the like. The dishwashing ¦ composition contains an anti-filming agent, or an anti-fflming agent and poly ¦ scrylic acid polymer or salt as anti-filming and anti-spotting agents, inorganic builder s~lts, chlorine bleach and bleach stable detergent.
The detergent dishwashing composition of t~e present invention reduced filming and/or spotting on dishware, glassware, china and the like, particularly in hard water at low temperature.

2 ~ More specifically, the invention relates to the use of a nonabrasive amount of small substantially water insoluble particles, e. g. silica, as an anti-fiIming agent and polyacrylic acid or s~lt polymer as an anti-spotting . ~ 2031289 agent in powder dishwashing detergent compositions to reduce filmlng andlor spotting.
The detergent compositions do not require an added rinse aid, are stable in storage and are readily dispersible in wash bath.
The present invention specifically relates to powder automatic dishwashing detergent compositions having improved anti-filming and anti-spotting properties, which are readily dispersible in the washing medium to provide effective cleaning of dishware, glassware, china and the lilce .
The present invention also relates to an improved powder composition and to a method of using the composition.
Bl~IEF DESCI~IPTION OI~ THE INVENTION
The present invention is directed to a powder automatic dishwasher detergent composition having improved anti-filming and/or anti-spotting properties for cleaning of dishware, glassware, china and the like. The detergent composition contains as an essential ingredient a nonabrasive amount of small substantially water insoluble solid particles as an anti-filming agent. The compositions can additionally contain a polyacrylic acid polymer or salt as an anti-spotting agent.
The present invention specifically relates to powder automatic dishwashing detergent powder compositions having improved anti-filming and/or anti-spotting properties for cleaning of dishware, glassware, china and the like.
The powder compositions are dry, free flowing and readily dispersed in the wash bath.
PRIOR ART
Commercially available household-machine dishwasher detergents provided in powder or liquid form have many disadvantages.
Commercially available powder detergents have the disadvantage8 of non-uniform composition; costly operations necessary in their manufacture;
tendency to cake in storage at high humidities, resulting in the formation of ' . ~ 2031289 lumps which are difficult to disperse; dustiness, a source of particular irrit~tion to users who suffer allergies; and tendency to cake in the dishwasher machine dispenser. Liquid forms of dishwashing compositions, however, generally cannot be used in automatic dishwashers due to high foam levels and unaccept~bly low viscosities.
In addition, the commercially available formulated powder detergents frequently require a separate step of hand towel wiping and drying of the dishware, glassware, china and the lilce to avoid leaving undesirable traces or film. The use of liquid detergent compositions present other problems.
The builder s~lts settle in storage and are not readily redispersed. The compositions also frequently become thicker in storage and are not readily pourable .
For effective use, it is generally recommended that the automatic dishwashing detergent, hereinafter also designated ADD, contain (1) sodium tripolyphosphate (NaTPP) to soften or tie up hard-water minerals and to emulsify and/or peptize soil; (2) sodium silicate to supply the alkalinity necessary for effective detergency and to provide protection for dishware, such as fine china and protection against machine corrosion; (3) sodium carbonate, generally considered to be optional, to enhance alkalinity; (4) a chlorine-releasing agent to aid in cleaning; ~5) a surfactant and (6) a f defoamer to reduce foam, thereby enhancing machine emciency. See, for example, SDA Detergents in Depth, "Formulations Aspects Of Machine Dishwashing," Thomas Oberle (1~79), Cleansers approximating to the afore-described compositions are mostly liquids or powders. Generally, such composition9 omit hypochlorite bleach, since it tends to react with other chemically active ingredients, particularly surfactant, thereby impairing its effectiveness.
Th~ls, U . S . Patent No . 3, 985, 668 describe~ abrasive scouring cleaners of gel-like consistency containing (~) suspending agent, preferably the Smectite and attapulgite type.~ of clay; (2) abrasive, e.g. silica sand or . ~ 2031289 ¦ perlite; and (3) filler comprising light density powdered polymers, expanded perlite and the like. The perlite has a bouyancy and thus stabilizing effect on the composition in addition to serving as a bulking ¦ agent, thereby replacing water otherwise available for undesired ¦ supernatant layer formation due to leaking and phase destabilization. The ¦ foregoing are the essential ingredients. Optional ingredients include hypochlorite bleach, bleach stable surfactnnt and buffer, e. g. silicates, ¦ carbonates, and monophosphates. Builders, such as NaTPP, can be ¦ included as further optional ingredients to supply or supplement building ¦ function not provided by the buffer, the amount of such builder not ¦ exceeding 5% of the total composition, according to the patent. Maintenance ¦ of the desired (greater than) pH 10 levels is achieved by the buffer/builder ¦ components. High pH.is said to minimize decomposition of chlorine bleach ¦ and undesired interaction between surfactant and bleach. When present, ¦ NaTPP is limited to 596, as stated. Foam killer is not disclosed.
¦ U . S . Patent 9, 511, 487 dated April 16, 1985 describes a low-foaming l detergent paste for dishwashers, The composition is based on a mixture of ¦ finely divided hydrated sodium metnsilicate, an active chlorine compound ¦ and a thickening agent which is a foliated silicate of the hectorite type.
¦ Small amount of nonionic tensides and alkali metal carbonates andlor hydroxides may be used.
ADVANTAGES OVER THE PRIOR ART
The powder detergent compositions of the present invention overcome many of the prior art problems associated with powder and liquid 2~ detergents. Because of the addition of a small effective amount of a silica anti-filming agent or silica and polyacrylic acid polymer or salt anti-spotting agent to the composition an added rinse aid is not required to obtain dry sparkling clean dishes, glasses, cups and eating utensils.
. .

. 3 2031289 The powder dctergent composition has the additional ndvantages of being stnbls in storage and readily redispersible in the dishwashing machines. The powder compositions of the present invention are easily pourable, easily measured and easily put into the dishwashing machines.
An additionnl and unexpected advantage of adding the silica anti-filming agent to the detergent formulation is that the silica inhibits brown stain formation in the dishwashing machine. The brown stain is formed by the deposition in the dishwashing machine of iron and/or manganese oxides. The brown stain formation is a particularly serious problem in areas having hard water. The silica in the formulation acts on the iron and/or manganese in the wash water to prevent their deposition in the dishwashing machine as iron and/or manganese oxides.
The powder detergent compositions of the present invention are stable in storage, are readily dispersed and, with the exception of the anti-film agent, are easily soluble in the dishwashing machine.
OBJECTS OF THE PRESENT INVENTION
It is an object of the present invention to provide a powder automatic dishwasher detergent composition that has improved anti-filming and/or anti-spotting properties.
It is another object of the invention to provide a powder detergent composition which is stable in storage, does not degrade or decompose, i8 readily dispersible and is easily soluble in the dishwashing w~ter.
A further object of the invention is to provide a method of washing dishware, glassw~re, china and the like in an automatic dishwashing machine using a powder detergent composition in which a separate rinse aid is not added or needed.
A still further object of the invention is to provide a method of washing dishware, glassware, china and the like in an automatic washing machine using a powder detergent composition by which method the .. ~ 2031289 :

dishware, glassware, china and the like are machine dried with reduced film, and spots.
It is a further object of this invention to provide stable dry powder detergent compositions, especially automatic dishwasher detergent S compositions, by incorporating in the composition a small effective amount of a silica anti-filming agent or silica and polyacrylic acid polymer or salt as anti-filming and anti-spotting agents.
DETAILED DESCRIPTION OF THE INVENTION
These and other objects of the invention which will become more readily understood from the following detsiled description of the invention and preferred embodiments thereof are achieved by incorporating in a powder detergent composition a small but effective amount of a silica anti-filming agent or silica anti-filming agent and polyacrylic acid polymer or salt anti-spotting agent. More particularly, according to a preferred and specific embodiment of the invention, there is provided a powder automatic dishwasher detergent composition in which is incorporated from about 0. 5 to 594 of a silica anti-filming agent or silica anti-filming agent and 1 to 15% of a water soluble polyacrylic acid polymer or salt anti-spotting agent. The silica anti-filming agent has a particle size of about 0.1 to 10 microns. The water soluble polyacrylic acid or salt polymer has a molecular weight of about 1000 to 100,000.
In accordance with the present invention there is provided a dry powder automatic ~ishwasher detergent composition which includes, on a weight basis;
(a) 20 to 70% organic or inorganic builder salt;
(b) S to 4096 sodium silicate;
(c) chlorine bleach compound in an amount to provide 0.5 to 8%
available chlorine;
(d) 0.5 to 5~ silica anti-filming agent;
(e) 1 to 1596 polyacrylic acid polymer or salt;

~ 2031289 (f) 0 to 30% ulkali metal carbonate;
( g) 0 ,1 to 6% chlorine bleach stnble, water dispersible organic detergent active material;
(h) ~ to G% chlorine bleach stable foam depressant; und (i) 0-30~ sodium sulfate.
The present invention also provides a method for cleaning dishware, glassware, china and the like in an automatic dishwashing muchine with an aqueous wash bath contnining an effective amount of the automatic dishwasher detergent (ADD) powder composition us described above.
According to this aspect of the invention, the ADD composition is a dry, free flowing powder and can be readily poured into the dispensing cup of the automatic dishwashing machine and will remain within the dispensing cup until subjected to the water spray from the dishwashing machine.
The invention will now be described in greater detail by wsy of speciSc embodiments thereof.
In accordunce with the present invention un improved uutom4tic dishwasher detergent composition is prepared by incorporating small amounts of a silica anti-filming agent or silica anti-filming agent and polyacrylic acid polymer or salt anti-spotting agent in a dishwasher composition .
The present invention is based upon the discovery that substantially improved anti-filming and/or anti-spotting properties can be obtained by adding to the powder detergent composition a small effective amount of a silica anti-filming agent or silica anti-filming agent and polyacrylic acid polymer or salt anti-spotting agent.
ANTI-FILMlNG AGENTS
The anti-filming agent comprises a nonabrasive amount of small substantially water insoluble particles. The anti-filming agent can be a member selected from the group consisting of silica, alumina and titanium dioxide and mixtures thereof.

....
.

. _ ~ 2031289 Silica The silica nnti-filming agent materials that can be used are fumed or precipitated synthetic or natural silica. The silica may be amorphous or crystalline .
The silica material that is used may contain up to about 0.1 to 5%
alumina (A1203 ), usually up to about 0 . 5 to 396 and more usually about 1%
alumina, based on the weight of silica.
A preferred silica material is Syloid 249 which is amorphous silica, has a particle size of about 4 microns and is provided by W . R . Grace Co .
Another suitable silica material is Silox 15, olso from W.1~. Grace Co., which has a particle size of about ~ microns.
Another preferred silica material is Huber Zeo 49 which i9 amorphous silica and is provided by J . M . Huber Corporation and contains about 1%
alumina (A12O3). The presence of as little as 1% A12O3 is found to help reduce the hydrolysis and subsequent solubility of the silic~ in the highly alkaline automatic dishwashing detergent composition.
The particle size of the silica material that is used is important in achieving the desired anti-filming properties.
The silica particles that are used are finely divided and can have a particle size of about 0.10 to 10 microns, preferably 0.50 to 8 microns and more preferably about 1. 0 to 5 . 0 microns . The silica particles of this size and the amount used herein are not abrasive.
The finely divided silica material particles in the dishwashing wash act to coagulate proteinaceous particulate soils and keeps them in suspension to 2~ prevent them from depositing on the clean glas~ and dishware to form a film.
Alumina The alumina material that can be used as an anti-filming agent is commercially available and i9 insoluble in water and has the formula A12O3.
Suitable materials are available under the tradenames Alumina Oxide C, available from Degussa Comp~ny und C~t~pal D, available from Vist~ Corp.
Preferred aluminu matcrials are fumed alumina and a precipitated alumina.
Titanium Dioxide The titanium dioxide material that cnn be used as an anti-filming agent is insoluble in water and has the formula TiO2. Suitable materials are available under the tradenames Titanium Dioxide P25, available from Degussa Co. Preferred titanium dioxide materials are fumed titanium dioxide and precipitated titanium dioxide.
The particle size of the alumina and titanium dioxide material that are used is importnnt in achieving the desired anti-filming properties.
The alumina or titanium dioxide particles that are used are finely divided nnd can have a particle size of about 0 . 01 to 10 microns, preferably 0 . 01 to 8 microns and more preferably about 0 . 020 to 9 . 0 microns . For example, a suitable particle size is about 0.01 to 0.50 microns. The alumina lS and titanium dioxide particles of this size and in the amount used herein are not abrasive.
The finely divided alumina or titanium dioxide material pnrticles in the dishwashing wash act to coagulate proteinaceous particulate soil~ and keeps them in suspension to prevent them from depositing on the clean glass and 20 - dishware .
Without intending to limit the invention in anyway it is theorized that the alumina and titanium dioxide anti-filming agents function in the following manner. The glnss surface of vitreous glassware contain negative charged on their surface through the Si-O bonds; Usually the oxygen atoms carry these charges. It is postulated that these negatively charged ions will attrsct positively charged particles and thereby will form an "artificial soil"
layer. This protective mono-layer will then repel the regular food soil and will increase the anti-redeposition property of the automatic dishwashing detergent. The alumina and titanium dioxide particles, respectively, will generate positively chnrged particles which will bond themselves to the . - 2031289 :
glassware surface to form the artificial soil layer which will prevent the formation of film.
The arnount of silica, aluminu or titunium dioxide anti-filming agent that can be used to achieve the desired improvement in film will depend on the hardness of the water, detergent active compound, inorganic salts and other ADD ingredients. The silica, alumina or titanium dioxide anti-filming agents are particularly effective in hard wash water of, for example, 300 ppm hardness or more.
The amount of each of the silica, alumina or titanium dioxide anti-film agent that is used can be about 0.5 to 5%, preferably about 1 to 4% and more preferably about 1. 5 to 3% by weight based on the weight of the entire composition.
The silica, alumina and titanium dioxide can each be used alone or one or more of them can be used mixed together. When the anti-filming agents are used mixed together the weight percent amounts mentioned above are the totol for the anti-film agent ingredients used in the mixture.
ANTI-SPOTTING AGENTS
Polyacrylic Acid Polymers And Salts Thereof The polyacrylic acid polymers and salts thereof anti-spotting agents that can be used are generally commercially available ~nd are briefly described as follows.
The polyacrylic acid polymers and salts thereof that can be used comprise water soluble low molecular weight polymers having the formula R3 COOM n wherein the R1, R2 and R3 can be the same or different and can be hydrogen, C1-C4 lower alkyl, or combinations thereof. The value of n is 5 to 1000, preferably, 10 to 500, and more preferably 20 to 100, M

.. - -- 2031289 represents hydrogen, or an alkali metal such as sodium or potassium. The preferred substituent for M is sodium.
The preferred Rl, R2 and R3 groups are hydrogen, methyl, ethyl and propyl. Preferred acrylic ncid monomer is one where R1 to R3 are hydrogen, e. g. ~crylic acid, or where R1 and R3 are hydrogen and R2 is methyl, e.g. methyl ucrylic acid monomer.
The degree of polymerization, i. e . the value of n, is generally determined by the limit compatible with the solubility of the polymer in water. The terminnl or end groups of the polymer are not critical and can be H, OH, CH3 or a low molecular weight hydrocarbon.
The polyacrylic acid polymers and salts thereof can have a molecular weight of 500 or 1,000 to 100,000, preferably 1,500 to 80,000 and especially preferably 2,000 to 50, 000 .
, Specific polyacrylic acid polymers which can be used include the Acrysol LMW acrylic acid polymers from Rohm and Haas, such as the Acrysol LMW-45N, a neutralized sodium salt, which has a molecular weight of about 4, 500 and Acrysol LMW-20NX, a neutralized ~odium salt, which hns a molecular weight of about 2,000. Other polyacrylic acid polymers or salts thereof that can be used are: Alcosperse 199, molecular weight 2000, Alcosperse 123, moleculsr weight 4500, Alcosperse 107, moleculnr weight 3000, Alcosperse 129, molecular weight 2000, and Alcosperse 602N molecular weight 4500, all of which are availnble from Alco Chemical Corp. The low molecular weight acrylic acid polymers can, for example, have n molecular weight of about 1,000 to 10,000. Another polyacrylic acid polymer that can be used is Alcosperse 110 (from Alco) which is a sodium salt of an organic polycarboxylate nnd which hus a molecular weight of about 100,000.
The nbove polyncrylic acid polymers and salts thereof can be made using procedures known in the art, see for example U.S. Patent 4,203,858, The amount of polyacrylic acid polymer or salt that can be used to achieve the desired improvement in anti-filming and anti-spotting properties ~ -- 2031289 will depend on the hardness o the water I detergent active compound, inorganic salts and other ADD ingredients.
The polyacrylic acid or salt anti-spotting agent is particularly effective in reducing spotting in hard water of, for example, 300 ppm hardness or more .
Generally, the amounts of the polyacrylic acid polymer or salt anti-spotting agent that can be used are in the range of from about 1. 0 to 15%, preferubly from about 2 . O to 12%, especially preferably about 4 to 10% .
BVILDER SALTS
Generally, ADD effectiveness is directly related to (a) available chlorine levels; (b) alkalinity; (c) solubility in washing medium; and (d) foam inhibition. It is preferred herein that the pll of the ADD composition be at least about 9 . 5, more preferably from about lO . 5 to 13 . 5 and most preferably st least about 11. 5 .
The amount of alkali metal silicate added and the amount of slkali metal TPP added can be used to obtain the desired alkalinity. The sodium carbonate can be added to act as a buffer to maintain the desired pH level in the wash bath. The sodium carbonate can be added in an amount of 0 to 30 wt.%, preferably 5 to 25 wt.% and typically about 8 to 20 wt.% of the detergent composition. The sodium'carbonate can be added for example in an amount of 15 to 20 wt.g6.
The compositions of the present invention can contain inorganic builder salts such as NaTPP or organic builder salts such as the alkali metal salts of citric and tsrtaric acid.
A preferred solid builder salt is an alkali metal polyphosphate such as sodium tripolyphosphate ("TPP"). In place of all or part of the alkali metal polyphosphate one or more other detergent builder salts can be used.
Suitable other builder salts are alkali metal borates, phosphates and bicarbonates .

. ~ ~ 2031289 Specific examples of such builders are sodium tetraborate, sodium pyrophosphate, potassium pyrophosphate, sodium bicarbonate, sodium hexametaphosphate, sodium sesquicarbonate, sodium mono and diorthophosphate and potassium bicarbonate.
The NaTPP may be employed in the ADD composition in a range of 20 to 70%, preferably about 20 to 60 wt.%, and more preferably about 25 to 45 wt.96, for example 20 to 40%. The NaTPP may be anhydrous or hydrated, including the stable hexahydrate with a degree of hydration of 6 corresponding to about 18~ by weight of watel or more.
Since the compositions of this invention are generally highly concentrated, and, therefore, may be used at relatively low dosages, it is desirable to supplement any phosphate builder (such 8S sodium tripolyphosphate) with an auxiliary builder such as an alkali metal polycarboxylic acid. The NaTPP may be replaced in whole or in part by the alkali metal polycarboxylic acid. Suitable alkali metal polycarboxylic acids are alkali metal salts of citric and tartsric acid, e. g. monosodium and disodium citrate tanhydrous). The sodium salts of citric and tartaric acids are preferred.
Alkali metal sulfates, preferably sodium sulfate is added as an anhydrous filler material. The sodium sulfate can be added in an amount of 0-30%, preferably 5 to 25%, and more preferably 10 to 20% by weight of the composition .
Foam Inhibitors Foam inhibition is important to increase dishwasher machine efficiency and minimize destabilizing effects which might occur due to the presence of excess foam within the washer during use. Foam may be sufficiently reduced by suitable selection of the type and/or amount of detergent active material, the main foam-producing component. The degree of foam is also l3 somewhat dependent on the hardness of the wash wuter in the machine whereby suitable ndjustment of the proportions of NaTPP which has a water softening effect may aid in providing the desired degree of foam inhibition.
However, it is genernlly preferred to include a chlorine bleach stable foam S depressant or inhibitor. Particularly effective are the alkyl phosphonic acid esters of the formula ll OR
available, for example, from BASF-Wyandotte (PCUK-PAE), and especially the alkyl acid phosphate esters of the formula O ' .

HO--P--OR

OR
available, for exsmple, from Hooker (SAP) and Knapsack (LPKN-158), in which one or both R groups in ench type of ester may represent p y a Cl2_20 alkyl group. Mixtures of the two types or any other chlorine bleach stable types, or mixtures of mono- and di-esters of the same type, may be employed. Especially preferred i~ a mixture of mono- and di-C16 18 alkyl acid phosphate esters such as monostearyl/distearyl acid phosphates 1,2/1 (Knapsack). When employed, proportions of O . 01 to 6 wt . %, preferably O .1 to 5 wt . %, especially about O .1 to O . 5 wt . %, of foam depressnnt in the composition is typical. The weight ratio of detergent active component to foam depressant generally ranging from about 15 :1 to 2 :1 and prefernbly about 10 :1 to 4 :1. Other defoamers which may be used include, for example, the known silicones.
Although any chlorine bleach compound may be employed in the compositions of this invention, such as sodium hypochlorite and calclum hypochlorite, sodium dichloro-isocyanurate, dichloro-dimethyl hydantoin, and chlorinated TSP, sodium dichloro-isocyanurate is preferred. The . _ ~ 2031289 composition should contain sufficient chlorine bleach compound to provide about 0 . 5 to 8 . 0% by weight of available chlorine, as determined, for exnmple, by acidification of the composition with surfuric acid. A solution containing about 0.9 to 14,3% by weight of sodium dichloroisocyanurate contains or provides roughly the same percentage of available chlorine.
The composition can preferably contain about 1 to 3% available chlorine.
For example, n solution contnining about 1.8 to 5.4% by weight sodium dichloroisocyanurate dihydrste contains about 1 to 396 by weight of available chlorine and is especial}y preferred.

The sodium silicate, which provides Dlkalinity nnd protection of hnrd surfaces, such as fine china, is employed in an amount ranging from about 5 to 40 wt . %, prefernbly about 8 to 35 wt . ~, and more preferably about 10 to 25 wt . %, in the composition. For example the composition can contain 8 to 25% sodium silicate. The sodium silicate also protects the washing machine from corrosion. The sodium silicate can have a Na20: SiO2 ratio of 1,6/1 to 1/3,2. The sodium silicute can be added in the form of a dry powder or an aqueous solution, preferably having an Na20: SiO2 ratio of from 1/1 to 1/2.8, for example, 1/2,4. Potassium silicates of the same ratios can also be used. The preferred ulkali metal silicates are sodium disilicate and sodium metasilicate.
Most of the other components of the composition, especially calcium hypochlorite and foam depressant can be added in the form of dry powders or aqueous dispersions or solutions.
The detergent active materials used in the present invention are 2 5 selected to be stable in the presence of chlorine bleach . The organic nonionic and anionic detergents can be used.
Liquid Nonionic Surfactant Detergents The liquid nonionic surfactant detergents that can be used in the practice of the present are preferably the low foam nonionic surfactants.

Useful nonioIlics are represented by the low foam Plurafac series from BAS~ Chemicul Company which are the reaction product of a higher linear alcohol and a mixture of ethylene and propylene oxides, contuining a mixed chain of ethylene oxide and propylene oxide, terminated by a hydroxyl group. Examples include a C13-C15 fatty alcohol condensed with 6 moles ethylene oxide and 3 moles propylene oxide, a C13-C15 fatty alcohol condensed with 7 moles propylene oxide and 4 moles ethylene oxide and a C13-C15 fatty alcohol condensed with 5 moles propylene oxide and 10 moles ethylene oxide.
Other useful surfact~nts are Neodol 25-7 and Neodol 25-6.5, which products are made by Shell Chemical Company, Inc. The former is a condensation product of a mixture of higher fatty alcohols averaging about 12 to 15 carbon atoms, with about 7 mols of ethylene oxide and the latter i9 a corresponding mixture wherein the carbon atom content of the higher fatty alcohol is 12 to 13 and the number of ethylene oxide groups present averages about 6, 5 . The higher alcohols are primary alk~nols . Other example~ of such detergents include Tergitol 15-S-7 and Tergitol 15-S-9 (registered trademarks), both of which are linear secondary alcohol ethoxylates made by Union Carbide Corp. The former is mixed ethoxylation product of 11 to 15 carbon atoms linear secondary alkanol with seven mols of ethylene oxide and the latter is a similar product but with nine mols of ethylene oxide being reacted.
A preferred nonionic surfactant is available from Union Carbide Corporation under the trademark Tergitol MDS-42. This nonionic surfactant is a C12-C14 linear alcohol containing 5596 by weight random distributed oxyalkyl groups of which 42% are ethoxy and 58% propoxy groups.
Another nonionic surfactant that can be used in accordance -with the present invention has the following formula R-O-(PO)X-lEOlPO)H

R is an alkyl group having 8 carbon atoms, PO is a propylene oxide polymer attached directly to the oxygen of the alkyl group, x is 8 to 9, EOIPO represents a copolymer of ethylene oxide and propylene oxide in which the ethylene oxide and propylene oxide are randomly mixed. The molnr ratio of EO/PO is about 2 :1 to 5 :1, e. g. about 3 :1. The total number of EO and PO groups in the copolymer ure such that the number of EO and PO groups are 5 to 8 and the cloud point of the nonionic surfactant is about 20 to 30C.
A method of making the nonionic surfactant and a more complete description of the nonionic surfactant i8 given in the EPA published patent application 0086493 dated August 24, 1983 which i9 incorporated herein in its entirety.
Other useful nonionic surfactants are the Poly-Tergent S-LF
surfactants available from Olin Corporation. These surfactants are low foaming, biodegradable linear fatty alcohols. Surfactants of this type sre available under the tradenames Poly-Tergent S-LF 18, Poly-Tergent S-305-LF, Poly-Tergent S-405-LF and Poly-Tergent CS-1 Mixtures of two or more of the liquid nonionic surfactants can be used and in some cases advantages can be obtained by the use of such mixtures.
The detergent active materials used herein must be stable in the presence of chlorine bleach, especially hypochlorite bleach. In addition to the above discussed nonionic surfactants, anionic surfactants can also be used .
Anionic Surfactants The anionic surfactants that can be used are the linear or branched alkali metal mono- and/or di-(C8 14) alkyl diphenyl oxide mono andlor disulphonates, commercially available for example as DOWFAX (Registered Trademark) 3B-2 and DOWFAX 2A-l Other suitable surfactants include the primary alkyl sulphates, alkyl sulphonates, alkylaryl-sulphates and sec. alkyl sulphates. Examples include . -: - 2031289 sodium C10 18 alkyl sulphates such as sodium dodecyl sulphate and sodium tollow alcohol sulphate; sodlum C10 18 alkane sulphonates such as sodium hexadecyl-1-sulphonate and sodium C12 18 alkylbenzene sulphonates such as 80dlum dodecylbenzene sulphonates. The corresponding potassium salts may also be employed.
Surfactants of the foregoing type, all well known in the art, are described, for example, in U.S. Pntents 3,~85,668 and 9,271,030, which are incorporated herein by reference thereto.
The surfnctants are used in amounts of 0.1 to 6%, preferably 0. 5 to 6.0%, and more preferably about 1.0 to 5.0%, for example 2 to 9%.
Various conventional ingredients may be included in these compositions in small amounts, generally less than about 4 wt . ~6, such as perfume, hydrotrop;c agent~ such as the sodium benzene, toluene, xylene and cumene sulphonates, preservatives, dyestuffs and pigments and the like, all of course being stable to chlorine bleach compound and hlgh alkalinity.
Especlally preferred for colorlng are the chlorinated phthalocyanines and polysulphides of aluminosilicate which provide, respectively, pleQsing green and bluc tints.
The powder ADD compositions of this invention are readily employed in known manner for washing dishes, glasses, CUp8, eating utensils and the like in an automatic dishwasher, provided with a suitable detergent dispenser, in an aqueous wash bath containing an effective amount of the composition.
In sn embodiment of the invention a powder autom~tic dishwsshing 2S detergent composition is formulated using the below named ingredients.

Preferred Component Wcight Percent Weight Percent Sodium Tripolyphosphate 20-60 20-gO
Sodium Carbonate 0-30 8-20 Sodium Sulfate 0-30 10-20 Surfactant 0, 5-6 1-5 Sodium Silicate 8-35 8-25 Silica Anti-filming Agent 1-4 1,5-3 Sodium Polyacrylate 1-15 4-10 Anti-spotting Agent Sodium Dichloroisocyanurate 0 . 5 to 5 1. 0 to 3 . 0 (Available Chlorine) Color, Perfume 0.5 to 3.0 1 to 2 Moisturc 2-1~ 8-10 The powder detergent composition can be prepared as a regular strength composition containing sodium carbonate and sodium sulfate or as a concentrate composition in which all or a portion of each of the sodium carbonate and sodium sulfate have been omitted.
The dishwasher detergent compositions of the present invention can contain conventional dishwashing detergent composition additives. The formulations can be prepared with commercially available powder builders, chlorine bleach source compounds and surfactant compounds.
The formulations can be prepared using the conventional dry blending and agglomeration procedures used for the preparntion of dry powder detergent compositions.
In dry the blending procedure, nonionic surfactant is thoroughly mixed with STPP by overspraying it at 120F in a twin-shelled mixer. The STPP beads containing absorbed surfactant are then conditioned, that is allowed to sit overnight. The loaded STPP material is then successively mixed with anti-filming agent or anti-filming agent and polyacrylate acid polymer or salt, sodium carbonate, sodium sulfate and sodium silicate ' . ~ _ 2031289 granules. Finnlly sodium dichloroisocyanurllt~ is ~ldded nnd blended with the rest and mixed thoroughly in the mixer.
Another method for preparing the automatic dishwasher detergent powder compositions of the present invention is the agglomeration procedure. The agglomeration procedure provides better bleach stability by coating the nonionic surfactant with the sodium silicate which separates the nonionic surfactant from the reactive bleach.
In accordance with the agglomeration procedure, about half of the STPP builder salt in the form of powder granules is introduced into a rotary drum and sprayed with the nonionic liquid surfactant at a temperature of about 120F. The STPP granules during the spraying operation are maintained at a temperature of about 100F.
The STPP granules loaded with the nonionic surfactant are dried overnight. The loaded dried STPP is mixed with the remaining STPP, anti-filming agent or unti-filming agent and polyacrylic acid or salt, sodium carbonate and sodium sulfate in an agglomerator.
An aqueous solution of sodium silicate is then sprayed on the mixed powders in the agglomerator.
The mixed agglomerated powders are then added to a granulator in order to sieve out the desired particle size of the agglomerate. From the granulator the powder composition is fed to a fluid bed drying unit to dry the powder. Finally, sodium dichloroisocyanurate is post added and blended with agglomerated granules to complete the process.
One or more ingredients can be omitted or additional ingredients such as perfumes and anti-foam agents can be added to the composition.
The order of adding the solid powder ingredients to the agglomerator is not particularly critical as long as good mixing is achieved.
The term dry powder composition~ as used herein is intended to include free flowing powder compositions containing 0-15% moisture, typically 2-1496 and more typically 4-1296 moisture,- for example 8-10%, The moisture . _ ~ 2031289 can be present in the form of hydrated compounds, for example, sodium tripolyphosphate hexahydrate, hydrated sodium carbonate, hydrated sodium sulfate and dichloroisocynnur~tc dihydrnte ~In(l/or ln tlle form Or unboun~l water. It is preferred that the composition contain less than about 10%
moisture as unbound water.
All amounts and proportions referred to herein are percent by weight of the composition unless otherwise indicated.
The invention may be put into practice in various ways and a number of specific embodiments will be described to illustrate the invention with reference to the accompanying examples.

Example 1 In accordance with the present invention automatie dishwasher powder detergent compositions are formulated using the below named Ingredients in the amounts indicated.
A B
Prior Art . Invention Commercial Ingredient Powder (Wt . ~)Powder (Wt . %) Sodium Tripolyphospate 3q,8 34.8 Sodium Carbonate 19 . 0 19 . 0 Sodium Sulfate 19 . 0 21. 5 Nonionie Surfaetant( ) 3.0 3.0 Sodium Silicate (1:2.4) 12.0 12.0 Siliea Anti-filming Agent 2.5 --Sodium Dichloroisocyanurate Dihydrate(2) 1.8 1,8 Moisture . 7 9 7 9 100, 00 100 . 00 (1) Tergitol MDS-42, from Union Carbide Corporation.
1$ (2) ACl 56, 1% availabIe ehlorine, Monsanto Corporation.
The two above formulations (A) and (B) are tested and eompared for film and spot formation. The formulations are tested in a Kenmore automatie dishwasher using the proeedure described in ASTMD 3566-79, exeept that only four eleaning eyeles are used. The filming and spotting are evaluated aeeording to the following seales:
Film Rating Seale 1. Best, no apparent film a. Filming slight, becoming upparent 3. Notieeable film, increasing 4. Continued increase of signifieant film 5, Filming becoming excessive 6. Filming high, exeessive buildup 7, Continued increase of excessive film.

Spot Ratin~ Scale A. Best - no spots B, Very few spots apparent C. Distinct D. Significant coverage approximntely 50~.
The above compositions are tested cleaning glass tumblers.
The ASTM Method D3556-7~ for the deposition on glassware during mechanical dishwashing, as mentioned above, is used to evaluate the buildup of spots and film on glassware. 50 grams of the invention powder detergent composition (A) and 50 grams of the commercial powder detergent composition (B) detergent are used in each test. All testing reported is done in Kenmore Model 587,1548580 and/or model 587.154G580 Automatic Dishwasher, The water wash temperature is 120F and the water has 300 ppm hardness, The results obtained in the fourth cycle are reported below, Formulation Spot Film .
Invention Formulation (A) B-C 1-2 Commercial Formulation (B) B-C 4-5 The commercial powder gives more film than the invention powder ADD
compositions. There is no difference in the spot scores.

. . 2031289 Example 2 Following the ~eachings of the present invention powder uutomatic dishwasher detergent compositions ure formulated using the below named ingredients in the amounts indicated.
In order to demonstrate the improvement in anti-filming and anti-spotting performance three powder formulations are prepared. The first formulation (A) contains 2.24 wt.~ silica anti-filming agent, the second formulation (B) contains 2.24 wt.% silica anti-filming agent and 8 wt.%
sodium polyacrylate and the third formulation (C) contains no silica and no sodium polyacrylate.
Formulations A B C
Wt.% Wt.% Wt.%
N TPP(1) 34.50 34.50 34.50 Sodium Sulfate 18.86 10.86 21.10 Sodlum Carbonate 17, ~0 17,90 17,90 Sodium Silieate 10.00 10,00 10,00 Nonionie Surfactant 3,10 3,10 3,10 Silica Anti-filrning Agent 2.24 2,24 --Na Polyacrylate(4) -- 8.00 --Sodium Diehloroisocyanurate Dihydrate(5~ 1,80 1.80 1,80 Moisture 11,60 11,60 11,60 ~ 100.00100.00100,00 1. The NaTPP contains a minor amount of Na pyraphosphate and a minor amount of Na orthophosphate.
2. The nonionie surfactant is Tergitol MDS-42.
3. The siliea anti-filming agent is Syloid 244 silica.
4. The water soluble Na polyaerylate agent is Alcosperse 149-D 2000 MW.
5. ACl 56, 1 wt.% available chlorine.

~ ~ ~ 2~ 289 A dose size of 50 grams of cach of formulations (A), (B) and (C) are used to evaluate the efficacy of the anti-filming and anti-spotting agents.
The invention formulations (A) and (B) are evaluated with regard to film and spot against the commercial formulation (C) under 300 ppm water hardness in 4 cycle ASTM runs at 120F water wash temperature in e~ch test .
There are 10 glass tumblers used in each test. All three products are tested in the same GE dishwasher to minimize the machine effect. The results obtuined in each of the tests are reported below.

Performance Profile ASTM Test 300 ppm hard water, 120F
Glass Tumblers Invention Invention Commercial Average Value Formulation (A) Formulation (B) Formulation (C) of 10 Tumblers Spot Film Spot Film Spot Film 15 1 Cycle B 1 A 1 B 3 2 Cycle B 1. 5 A 1. 5 B-C 3 . 5 3 Cycle B-C 2 A-B 2 B-C 4 4 Cycle B-C 2-2.5 A-B 2-2.5 B-C 4-5 The invention formulation (A) performs better than commercial formulation (C) with regard to film formation. The inventive formulation (B ) performs better than invention formulation ~A) with regard to spot formation and better than commercial formulation (C) with regard to spot and film formation.
The above mentioned three products are also tested using 6 Melamine plates in each test.
¦ T results obtatned tn ellch Or the tcuts ere reported below.

1~ 25 . ~ - 2031289 Performance Profile ASTM Test 300 ppm hard water, 120F
Melamine Invention Invention Commercial Plate,s, Average Formulation (A) Formulation (B) Formulation (C) 5Value 6 Plutes Spot Film Spot Film Spot Film 1 Cycle A-B 1 A 1A-B
2 Cycle A-B 1 A 1 B 1 3 Cycle A-B 1 A-B 1B
4 Cycle A-B 1 A-B 1B-C 1 All three of the formulations gave no film. The inventive formulatlons (A) and (B) both performed substantially better against the commercial formulation (C) with regard to spot formation. The invention formulation (A) containing silica did not perform quite as well as invention formulation (B) containing silica and sodium polyacrylute with regard to spot formation.
The above duta show that the add,ition of silica anti-fllming agent or silica and polyacrylate anti-filming agents give improved performance against filming on glassware and dishware.

26' . - - 2031289 Example 3 Following the teachings of the invention a concentrate automatic dishwasher powder detergent composition is formulated using the below named ingredients.
Ingredient Weight Percent Sodium Citrute Builder Salt 50, 0 Sodium Carbonate Sodium Sulfate Nonionic Surfactant 4 . 0 Sodium Silicate (1:2.4) 18,0 Silica Anti-filming Agent( ) 5.0 Na Polyacrylate Anti-filming Agent(2) 16,0 Sodium Dichloroisocyanurate Dihydrate(3) 2.8 Moisture 4 . 2 1~0 (1) Syloid 244 Sil}ca (2) Alcosperse 14~-D
(3) ACl 56, 1,6% available chlorine.
About 28 grams of the above concentruted formulation, i. e . about one half the normal dose, i9 tested in an automatic dishwasher machine to clean 2 0 gluss tumblers .

The tumblers after u normul wash cycle are removed from the dishwasher and are found to be free of spots and to contain only a slight amount of film.

~7 .. - - 2031289 Example 4 Automatic dishwnshing powder detergent compositions are formulated from the following ingredients in the amounts specified.
Invention Comparison Formulation Formulation Alumina No Alumina Anti-film Agent Anti-film Agent Component Wt. % Wt %
NaTPP 34 oo 34 oo Knapsack LPKN-158 Foam Depressant 0.16 0.16 Sodium Carbonate ( anhydrous)15 . 00 15 . 00 Sodium Silicate (l/2,4) 15,00 15.00 Sodium Sulfate 24, 04 26, 04 Alumina Anti-filmin g Agent ( 1)2 . 00 ___ Poly Tergent SLF-18(2) 2 . 00 2 . 00 Sodium Dichloroisocyanurate Dihydrate(3) 1.80 1.80 Moisture 6 . 00 6, 00 100.00 100.00 (1) Aluminum oxide C has a particle size of 0.02 microns and is available from Degussa Co, (2) Nonionic Surfactant, Olin Corp, ~3) ACl 56, 1,0% available chlorine.
The ingredients are added in the order listed and mixed until a homogeneous powder mixture is obtained. The formulations are tested by washing glassware at 120F in hard water (300 ppm hardness).
20The two formulations are tested and compnred. The formulntions nre tested in a Kenmore nutom~tic dishwasher to clean glas~ tumblors usin~ the procedure described in ASTMD 35,66-79, except that only four cleaning cycles are used. The spotting and filming are evaluated as in Example 2 and the results obtained in the fourth cycle are reported in the below 2 5Table .

. - - 2031289 TAB LE;
Performance Rating Spot Film Invention Formulution Silica Anti-filming Agent B-C
Comparison Formulation No Alumina Anti-filming Agent B-C 4 The two formulations perform about the same on spot. The invention formulation performs substantially better on film.

.. ~ ................................ 2031289 Example 5 The above Example 4 is repeated with the difference that 2 . 00 wt . %
titanium dioxide is substituted for the alumina anti-filming agent. The formulations are tested by washing glassware at 130F in hard water (30Q
ppm hardness) as before. The results obtained in the fourth cycle are reported in the below Table.
TAB LE

Performance Rating Spot ~l~ilm Jnvention Formulation (Titanium Dioxide) 1 Comparison Formulation (No Anti-filming Agent) B-C 4 The two formulations perform about the same on spot. The invention formulation performs better on film.
The automatic dishwasher powder detergent compositions of the present invention provide improved film snd/or improved spot properties on glassware and dishware.
15' The invention is not to be limited by the above disclosure and examples which are given as illustrations only. The invention is to be interpreted in accordance with the below claims.

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Claims (20)

1. An automatic dishwashing powder detergent composition having improved film or improved film and spot performance comprising at least one ingredient selected from the group consisting of organic detergent, detergent builder, from inhibitor and mixtures thereof, and a nonabrasive 0.5 to 6.0% amount of small substantially water insoluble particles selected from the group consisting of silica, alumina, titanium dioxide and mixtures thereof as an anti-filming agent.

2. The composition of claim 1 containing a nonabrasive 0.5 to 5%
amount of the anti-filming agent.

3. The composition of claim 1 additionally comprising 1 to 15% of a water soluble polyacrylic acid polymer or salt anti-spotting agent.

4. An automatic dishwasher powder detergent composition comprising approximately by weight:
(a) 20 to 70% inorganic or organic detergent builder;
(b) 5 to 40% sodium silicate;
(c) 0 to 30% alkali metal carbonate;
(d) 0.1 to 6% chlorine bleach stable, water-dispersible organic detergent active material;
(e) 0 to 6% chlorine bleach stable foam depressant;
(f) chlorine bleach compound in an amount sufficient to provide about 0.5 to 8% of available chlorine; and (g) a nonabrasive 0.5 to 5% amount of an anti-filming agent which is a member selected from the group consisting of silica, alumina, titanium dioxide and mixtures thereof having a particle size of 0.01 to 10 microns.

5. The composition of claim 4 wherein the chlorine bleach compound is a member selected from the group of chlorocyanurates, dichloroisocyanurates, trichloroisocyanurates, and alkali and alkaline earth hypochlorites.

6. The composition of claim 4 additionally comprising 2 to 14% of a water soluble polyacrylic acid polymer or salt anti-spotting agent.

7. An automatic dishwasher powder detergent composition comprising approximately by weight:
(a) 20 to 60% alkali metal tripolyphosphate;
(b) 8 to 35% sodium silicate;
(c) 5 to 25% alkali metal carbonate;
(d) 0.5 to 6% chlorine bleach stable, water dispersible organic nonionic detergent active material;
(e) 0.1 to 5% chlorine bleach stable foam depressant;
(f) chlorine bleach compound in an amount sufficient to provide about 0.5 to 5% of available chlorine;
(g) a nonabrssive 1 to 4% amount of an anti-filming agent which is a member selected from the group consisting of silica, alumina, titanium dioxide and mixtures thereof having a particle size of 0.01 to 8 microns;
and (h) 0 to 12% moisture.

8. The composition of claim 7 additionally comprising 2 to 14% of a polyacrylic acid polymer or salt anti-spotting agent which has the formula wherein R1, R2 and R3 can be the same or different and can be hydrogen, C1-C4 lower alkyl, M represents hydrogen, or an alkali metal, n = 5 to 1000 and the polymer has a molecular weight of 1500 to 80,000.

9. The composition of claim 7 wherein the chlorine compound is sodium dichloroisocyanuarate or sodium trichloroisocyanurate or mixtures thereof .

10. The composition of claim 7 wherein the anti-filming agent is silica.

11. The composition of claim 7 wherein the anti-filming agent is alumina.

12. The composition of claim 7 wherein the anti-filming agent is titanium dioxide.

13. An automatic dishwasher powder detergent composition comprising approximately by weight:
(a) 25 to 45% alkali metal tripolyphosphate;
(b) 10 to 25% sodium silicate;
(c) 8 to 20% alkali metal carbonate;
(d) 0.1 to 0.5% chlorine bleach stable foam depressant;
(e) chlorine bleach compound in an amount sufficient to provide 1 to 3% available chlorine;
(f) a nonabrasive 1.5 to 3% amount of an anti-filming agent which is a member selected from the group consisting of silica, alumina, titanium dioxide and mixtures thereof having u particle size of 0.01 to 8.0 microns;
(g) 4 to 10% water soluble polyacrylic acid polymer or salt; and (h) 8 to 10% moisture.

14, The composition of claim 13 wherein the water soluble polyacrylic acid polymer or salt anti-spotting agent has the formula wherein R1 und R3 are hydrogen, and R2 is hydrogen or methyl, M
represents hydrogen, sodium or potassium, n = 10 to 500 and the polymer has a molecular weight of 2000 to 50,000.

15. The composition of claim 13 wherein the polyacrylic acid polymer or salt has a molecular weight of about 2000.

16. The composition of claim 13 wherein the polyacrylic acid polymer or salt has a molecular weight of about 4500.

17. The composition of claim 13 wherein the silica anti-filming agent contains about 0.1 to 5% of alumina, based on weight of silica.

18. The composition of claim 13 wherein the anti-filming agent has a particle size of about 1.0 to 5 microns.

19. A method for cleaning soiled glassware and dishware which comprises contacting the glassware and dishware in an automatic dishwashing machine in an aqueous washbath having dispersed therein an effective amount of the composition of claim 1 to obtain clean glassware and dishware with improved film and/or spot.

20. A method for cleaning soiled glassware and dishware which comprises contacting the soiled glassware and dishware in an automatic dishwashing machine in an aqueous washbath having dispersed therein an effective amount of the composition of claim 7 to obtain clean glassware and dishware with improved film and/or spot.