[0001] The invention relates to machine ware washing compositions, and particularly to such
compositions having high levels of alkali-metal carbonate as the sole builder.
[0002] Automatic dishwashing detergents (ADWDs) typically include a variety of specialized
components for specific purposes during the multi-step wash cycle. Surfactants may
be present for detergency and/or as rinse aids. Silicates act to provide alkalinity
and to prevent corrosion. Bleaches are often included for oxidizing power. Abrasives
may be included to provide scouring action. Builders are important to improve washing
performance, and must be selected to avoid precipitation of calcium salts on wares.
Typically, silicates, carbonates, phosphates or mixtures thereof are employed as builders.
For ware washing applications, the builder materials may provide alkalinity and buffering
capacity, prevent flocculation, maintain ionic strength, extract metals from soils
and remove alkaline-earth metal ions from washing solutions. Phosphates are extremely
effective in these applications, however, there is a relatively high cost associated
with their use. Additionally, phosphates are disfavored owing to their eutrophication
effect on lakes and streams, and may be regulated in some states. Silicates are not
preferred as the sole, or primary builder because they are costly, and at the generally
high levels required, are potentially toxic. High levels of alkali-metal carbonates
have been found to be very effective in ware washing applications, and have proven
to be superior in performance to phosphates in the removal of starchy soils, one of
the principal soils found on tablewares. A drawback associated with such high carbonate
levels, however, is that calcium ions present in the washing water readily form precipitates
with the carbonates. Various approaches have been employed to combat the formation
of calcium precipitates. Complexing agents such as zeolites can be added and can be
effective at removing calcium. These have limited use in ware washing compositions,
however, as these zeolites are substantially insoluble, and may themselves deposit
on tablewares. Polymeric sequestering agents such as polyacrylates and polyether carboxylates
can also be employed, but since these also act to complex the calcium, generally high
levels are required. Sequestering and complexing agents tend to be expensive, adding
significantly to the overall cost.
Schroeder, DE 3001937, discloses a granular ADWD with 50-70% sodium carbonate, a poly (alpha-hydroxy
acrylic acid), phosphonate threshold inhibitors and alkyl phosphate esters.
Becker et al, GB 1536136, describes a laundry detergent including a phosphonic or polyacrylic acid
sequestrant, a protective colloid and a maximum of 30% phosphate builder, with an
optional carbonate builder.
[0003] Unsubstituted polyacrylic acids used with 20-60% sodium carbonate are described in
US 3579455 issued to
Sabatelli and US 3627686 issued to
Brungs.
Brungs and
Sabatelli use relatively high levels of NTA and hexametaphosphate, respectively, to complex
calcium Sabatelli includes pyrophosphate as part of the complexing system US 4539144,
to
de Ridder et al describes ADWDs with no or low phosphates and with 5-50% of a sequestrant, 0.05-5%
of poly (maleic acid) and may have a sodium carbonate builder. Low molecular weight
polyacrylates without other chelating agents are used to inhibit calcium carbonate
deposition by ADWDs in
Chakrabarti, US 4203858.
[0004] In EP 266904 (
Frankena) sodium carbonate is combined with polyacrylate, phosphonates, and a dipicolinic
acid complexing agent. Similarly, in US 3850852 issued to
Neillie et al sodium carbonate can be combined with polyacrylates, phosphonates, and a calcium
sequestering agent.
[0005] US 4687592 to
Collins et al describes carbonate, polyacrylate, phosphonates, and a calcium sequestering agent
which is an ether polycarboxylate and comprises a major part of the formula. The polyacrylate
is added to disperse soils and the phosphonate is added to chelate iron and manganese.
Phosphonates and polyacrylates are also mentioned as possible co-builders in GB 2194546
to
Laitem et al and US 4588515 to
Schuh et al. In both patents, STPP is the preferred builder.
[0006] In US-A-4608188, there is described a low phosphate machine dishwashing composition
consisting essentially of a maleic acid-acrylic acid copolymer, an alkaline condensed
phosphate salt, a blend of non-ionic surfactants, an alkaline carbonate compound within
the range of 20-40 percent, the balance being conventional machine dishwashing composition
additives in normal amounts.
[0007] In EP-A-0289312 there is described the preparation of a granular detergent composition
in which separate slurries of a crystal-growth modified carbonate-based structurant
salt and of a main detergent composition are prepared in different vessels, then mixed
and spray dried. The maximum proportion of sodium carbonate salts is 35%.
[0008] In US-3579455 also mentioned above there is described a machine dishwashing composition
containing 20-60 parts by weight of an alkali metal carbonate and a ternary calcium
salt precipitation system made up of a tetra-alkali metal pyrophosphate, an alkali
metal hexametaphosphate and a water soluble polymer which may be a polyacrylic acid.
[0009] In US-3627686 there is also described a machine dishwashing composition containing
20 to 60 parts by weight of an alkali metal carbonate and a ternary calcium salt precipitation
system made up of a tetra-alkali metal pyrophosphate, an alkali metal nitrilotriacetate
and a water soluble polymer which may be a polyacrylic acid.
[0010] In EP-A-0353562 and WO 90/01534 there is disclosed a builder salt composition which
is primarily silicate based and contains washing soda, as well as sodium tripolyphosphate
and an acrylic or methacrylic acid polymer or copolymer.
[0011] Generally, high carbonate detergents are not preferred in the art. When high carbonate
levels are used, relatively high levels of complexing agents are used to prevent the
formation of calcium carbonate precipitates. Often the complexing agents themselves
offset any advantages gained by use of carbonates as builders.
[0012] In view of the art, there remains a need for an alkali-metal carbonate based ware
washing composition which prevents the deposition of calcium salts by inhibiting the
formation of calcium precipitates, rather than by sequestering or complexing.
[0013] It is therefore an object of the present invention to provide a high carbonate ware
washing composition having acceptably low levels of calcium precipitates.
[0014] It is another object of the present invention to provide a ware washing composition
which is superior in performance in removing starchy soils.
[0015] It is another object of the present invention to provide a highly effective dishwashing
detergent which avoids the use of potentially toxic materials.
[0016] It is another object of the present invention to provide a ware washing composition
which does not utilize high levels of phosphate builders.
[0017] It is yet another object of the present invention to provide a highly cost-effective
detergent composition.
SUMMARY OF THE PRESENT INVENTION
[0018] In one embodiment, the invention provides a dry detergent composition for use in
an automatic dishwasher comprising
(a) 40-80% of an alkali-metal carbonate as the sole builder;
(b) 2-10% of an alkali-metal silicate, having a SiO₂/M₂O ratio of between 1 and 4;
(c) a low-foaming surfactant; and
(d) a calcium crystal growth-inhibiting amount of an inhibitor system, comprising
0.1-10% of a polycarboxylic acid or salt selected from the group consisting of polyacrylic
or polymethacrylic acids having a molecular weight of between 1,000 and 10,000 g/mole;
and 0.1-5% of a threshold inhibiting agent selected from the group consisting of polyphosphonates/carboxylates
of mono-, di, and trialkylamines having at least one phosphonate group; 1-hydroxyethylidene-1,
1-diphosphonic acid; aminotri(methylenephosphonic acid); 2-phosphonobutane-1,2,4-
tricarboxylic acid; phosphonohydroxy acetic acid; and mixtures thereof.
[0019] Optionally, a halogen or peroxygen bleaching species can be included for oxidizing
power.
[0020] The automatic dishwashing detergent of the present invention is primarily comprised
of sodium or potassium carbonates and silicates, low levels of an inhibition system
comprising a low molecular weight polycarboxylic acid and a threshold inhibition agent,
and a low foaming surfactant. Polyacrylic an polymethacrylic acids with weight average
molecular weights between 1,000 and 10,000 are used as polycarboxylic acids. Suitable
threshold inhibition agents (TIAs) include the monomeric phosphonate-containing organic
compounds specified above, and mixtures thereof. Preferred TIAs include polyphosphonates
such as the Monsanto Company's trademarked DEQUEST series, phosphonated polycarboxylic
acids such as Mobay Chemicals trademarked BAYHIBIT series, and phosphonocarboxylic
acids. No other calcium complexing agents or builders such as sodium tripolyphosphate
are present in the detergent.
[0021] It is another advantage of the composition of the present invention that the carbonate
builder provides superior starchy soil removal without appreciable precipitation of
calcium salts.
[0022] It is a further advantage of the present invention that the composition is more cost-effective
than other builder systems.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Alkali-Metal Carbonate
[0023] The alkali-metal carbonate is the sole builder material of the composition of the
present invention. Alkali-metal carbonates, sesquicarbonates and bicarbonates are
suitable, and preferred are sodium and/or potassium carbonates. At least 40%, preferably
60% carbonate is needed. As used herein unless otherwise stated all percentages are
weight percentages. Higher levels of carbonates will function, however, at levels
greater than 80% there is insufficient room for the other ingredients which contribute
to the overall effectiveness of the composition. The carbonate acts as a builder to
remove calcium and additionally provides alkalinity and aids in soil removal. At the
high levels disclosed herein, the alkali-metal carbonate provides superior starchy
soil removal compared to other builders such as phosphates.
Alkali-Metal Silicate
[0024] One component of the present invention is an alkali-metal silicate, specifically
one having the formula: M₂O(SiO₂)n where M represents an alkali-metal, and n is between
1 and 4. Preferred alkali-metal silicates are sodium, potassium and lithium silicates,
with sodium silicate being the most preferred, and with a preferred n value of 2.0-2.4.
A most preferred maximum value for n is 3.2 in order to minimize insoluble silicates
during storage. It is further preferred that at least 10% of the total silicates have
an n value of greater than 1.6 to impart suitable anti-corrosive properties. Examples
of other suitable silicates include sodium or potassium orthosilicates and metasilicates.
As used hereinafter, the term "silicate" will be taken to mean any of these alkali-metal
silicates, individually or combined.
[0025] Mixtures of any of the foregoing alkali-metal silicates are also suitable. The alkali-metal
silicate is present in an amount of from 2% to 10%. A minimum of 2% silicate is necessary
to provide adequate corrosion resistance. Preferred commercially available sodium
silicates are sold by the Philadelphia Quartz Corporation under the Trademarks RU,
as a 47% solution, and D, as a 44.1% solution. In addition to their anti-corrosive
effects, the silicates provide alkalinity and serve as granulating aids to increase
particle size of the agglomerates. Sodium silicates are known to be very effective
at cleaning, especially when used on oil and grease stains.
Inhibitor System
[0026] The inhibitor system, comprising a polycarboxylic acid, or salt, in conjunction with
low levels of a threshold inhibition agent, acts to inhibit significant calcium precipitates,
resulting in aesthetically pleasing tablewares. The polycarboxylic acid is a polyacrylic
or polymethacrylic acid having a weight average molecular weight range of 1000-10,000
g/mole, preferably 2000-5000 g/mole.
[0027] It is preferred to add the polycarboxylic acid in fully neutralized form, e.g. as
a sodium or potassium salt, however, the acid form is equally effective in preventing
the deposition of calcium salts. It is noted that for the purpose of the present invention
the acid forms are equivalent to the salt forms except where the acid has limited
solubility. It is also noted that except where explicitly stated or implied from the
context, the acid and salt forms are used interchangeably. It is further noted that
if added as salt, the required weight percentage range will be higher than that of
the acid, owing to the presence of the counterion. For example a 30% greater weight
percentage of sodium polyacrylate is needed compared to the acid form. An example
of a commercial source of the polycarboxylic acids is the Rohm and Haas Company's
ACRYSOL polyacrylates. Preferred are ACRYSOL LMW-20N and LMW-45N, fully neutralized
polyacrylic acids, sodium salts, having weight average molecular weights of 2,000
and 4,500 g/mole, respectively. 0.1-10% polycarboxylic acid is present, preferably
3-8%. Higher levels of polycarboxylic can be added, but they do not appear to correspondingly
improve inhibition of calcium precipitates.
[0028] The other component of the inhibitor system is the threshold inhibition agent, (TIA),
which at the low levels, i.e. 0.1-5 percent present in the composition, synergistically
acts with the polycarboxylate to prevent the formation of calcium precipitates on
wares washed with the composition. The TIAs are poly phosphonates/carboxylates of
mono-, di-, and tri- alkylamines having at least one phosphonate group;1-hydroxyethylidene-1,
1-diphosphonic acid (HEDP); aminotri-(methylenephosphonic acid) (ATMP); 2-phosphonobutane-1,2,4-tricarboxylic
-tricarboxylic acid (PBTC); phosphonohydroxy acetic acid, and mixtures thereof. TIAs
are most preferably HEDP, ATMP, PBTC, and mixtures thereof. A preferred level for
TIA is 0.1-3.5%, and more preferred is 0.3-2.0%. The TIA generally should be kept
at low levels for to minimize the amount of phosphorus in the system and to minimize
cost. Two percent TIA corresponds to a level in the wash (assuming 10 L of wash water)
of 60 ppm. Generally, increasing TIA levels in the main wash above 60 ppm does not
yield a corresponding increase in effectiveness, thus the lower levels are more cost-effective.
Finally, if too much phosphonate is present, it can form a precipitate with calcium.
The TIA/polymer system is effective at preventing observable calcium precipitates
on wares in waters having hardness levels at least to 400 ppm. The TIA may be added
as an acid, or as salt, such as sodium or potassium. The inhibitor system is added
at a level necessary to inhibit the precipitation of calcium salts on the wares. The
exact level will vary with water hardness and type of polycarboxylic acid and TIA.
It is noted that generally, increasing the level of polycarboxylic acid allows for
a decrease in the level of TIA, and vice versa. It is again noted that the acid and
salt forms are equivalent except where the acid has limited solubility. It is also
again noted that the foregoing TIA weight percentage ranges are based on the acid
forms.
Low Foaming Surfactant
[0029] A low-foaming surfactant is included to provide detergency during the wash phase
of the machine wash cycle, and to promote "sheeting" during rinse, i.e. uniform runoff
of the rinse water. The surfactant further acts to emulsify oily soils and suspends
solids to prevent their redeposition. Since machine dishwashers utilize the mechanical
effects of water sprays to remove a significant amount of solids, the surfactant must
not produce foams, which impair this mechanical cleaning action. Preferably the surfactant
will reduce or inhibit foams which are produced by food soils.
[0030] Preferred surfactants are nonionics, especially C₁₋₄ alkoxylated aliphatic alcohols
and C₁₋₄ alkoxylated alkyl phenols. Particularly preferred are ethoxylated/propoxylated
C₈₋₁₄ alcohols. There should be at least ten alkoxy groups per alcohol, preferably
at least twenty. Examples of preferred ethoxylated/propoxylated aliphatic alcohols
are BASF Corporation's trademarked INDUSTROL, and PLURAFAC. Certain C₁₋₄ alkylene
oxide copolymers such as ethylene oxide/propylene oxide copolymers are also preferred
as surfactants. These are exemplified by BASF's trademarked PLURONIC series. Optionally,
the terminal hydroxyls of any of the foregoing can be replaced by an ether, e.g. a
C₁₋₄ alkyl or a benzyl ether, or by a halogen, to further reduce foaming. Other suitable
surfactants are disclosed in US 4306987 and 4272394 both issued to
Kaneko and assigned to BASF Wayandotte Corporation.
[0031] It is also within the scope of the invention herein to utilize a mixture of surfactants
all of which may not be low-foaming as long as the mixture is low-foaming by, e.g.
including a foam suppressant such as monostearyl phosphate or other materials as known
in the art. As used hereinafter, "low-foaming surfactant" will be taken to mean an
individual low-foaming surfactant, or a mixture of two or more surfactants, or surfactants
and foam suppressants, yielding low foaming. The surfactant is added at a level of
up to 10 percent, preferably 1-5 percent.
Optional Ingredients
[0032] Various adjuncts can be added, as known in the art. Examples include fragrances,
dyes or pigments, enzymes such as proteases, lipases and amylases, additional corrosion
inhibitors. Water may be present up to 15%, and can be present as free water or as
water of hydration of the inorganic salts such as sodium carbonate. Some water may
be deliberately added as a filler. Additionally, filler materials include inorganic
salts such as sodium or potassium sulfates, nitrates, borates and chlorides, and organic
materials like sugars.
[0033] It may be desirable to adjust the pH of the wash water by including an electrolyte/buffer.
Generally, these are alkali-metal inorganic acid salts, hydroxides or oxides. It may
also be suitable to use such materials as aluminates and organic materials, such as
gluconates, citrates, succinates, maleates, and their alkali metal salts. The electrolyte/
buffer should maintain the wash pH range within a range of between 8.0 to 13.0, more
preferably 9.0 to 12.0. Sodium hydroxide is preferred as it does not interact adversely
with any other ingredients, and is very cost effective. It is noted that the silicates
and carbonates can also act to keep the wash pH range within the desired limits. The
amount of electrolyte/buffer added solely for purposes of buffering can vary up to
10%.
[0034] A particularly preferred adjunct is a bleach, which may be selected from various
halogen, peroxide or peracid bleaches. The bleach can remove organic stains, aids
in soil removal and helps to prevent spotting and filming. Most bleaches, in fact,
perform well in the relatively high temperatures associated with automatic dishwashers.
Examples of halogen bleaches include the alkali metal and alkaline earth salts of
hypohalite, haloamines, haloimines, haloimides and haloamides. All of these are believed
to produce hypohalous bleaching species
in situ. Hypochlorite and compounds producing hypochlorite in aqueous solution are preferred,
although hypobromite is also suitable. Representative hypochlorite-producing compounds
include sodium, potassium, lithium and calcium hypochlorite, chlorinated trisodium
phosphate, potassium and sodium dicholoroisocyanurate, trichlorocyanuric acid, and
their hydrates. Also suitable are hydantoins, such as dibromo and dichloro dimethyl-hydantoin,
chlorobromodimethyl hydantoin, N-chlorosulfamide (haloamide), chloramine (haloamine),
N-brominated and N-chlorinated succinimide, malonimide, pthalimide and napthalimide.
Peroxygen bleaches also are effective. Sodium perborate is a particularly useful bleach
source, and may be formulated as a mono- or tetrahydrate. Preferred peroxygen bleaches
are available in solid form and include sodium percarbonate, sodium perborate, sodium
phosphate peroxyhydrate, potassium permonosulfates and metal peroxides. Bleach activators,
also known as peracid precursors can be included with the peroxygen compounds. Examples
of activators include tetraacetyl ethylenediamine (TAED), and nonanoyloxy benzenesulfonate
(NOBS). Peracid bleaches (including monoperacids and diperacids) may be advantageous
in terms of bleaching performance. Suitable peracid bleaching species include C₈₋₁₂
alkyl peracids, especially perazelaic and diperazelaic acids, diperoxydodecanedioic
acid (DPDDA), and alkyl monoperoxysuccinic acid. Peracid bleaching species, and a
method for their production, are described in U. S. patent 4,337,213 issued June 29,
1982 to
Marynowski et al DPDDA is particularly preferred for use in the composition of the present invention
as it is relatively storage stable and produces desirable bleaching results. If added,
the bleach is present in an amount sufficient to provide effective bleaching, e.g.,
up to 10% by weight active, more preferably from 0.05 to 5% by weight active and most
preferably from 1 to 3% by weight active depending on the bleaching species chosen.
[0035] The dishwashing detergent composition is prepared by any means known in the art to
yield a dry, free-flowing granular mixture, such as agglomeration or spray drying.
Agglomeration is preferred. An O'Brien rotary drum agglomerator was used in the following
agglomeration example. Sodium carbonate and sodium sulfate filler (if desired) is
initially charged to the agglomerator. Three liquid additions are made during each
batch. Spray rates and atomizing air pressures can be set for each liquid addition
to suit desired finished product properties. The first liquid to be sprayed is the
low-foaming surfactant, sprayed at a rate of 0.227 kgs (0.5 pounds)/min. The second
liquid addition is a preblend consisting of the TIA, polymer, and sodium hydroxide,
and is applied at a preferred rate of 0.453 kg (1.0 pound)/min. The final liquid addition
is sodium silicate, which can be applied at ambient or elevated temperature, and at
a rate of 0.453 kg (1.0 pound)/min. The product may be dried/ conditioned at the completion
of the agglomeration. Static drying, fluid bed drying, and rotary drum conditioning
may all be applied. Static drying typically consists of holding the agglomerated product
at 60°C (140°F) for 24 hours while fluid bed drying may be performed for 30 minutes
at 60°C/(140°F). Finished product densities range between 0.6g/cm³ to 1.0 g/cm³. An
example formula is shown below.
Example I
[0036]
Ingredient |
Wt.% Active |
Alkali metal carbonate |
40-80 |
Low-foaming surfactant |
added up to 10 |
Bleaching agent |
0-10 |
Alkali metal silicate (SiO₂/M₂O = 2-3) |
2-10 |
Filler (sulfate, chloride, nitrate salts) |
0-50 |
Polycarboxylic acid |
0.1-10 |
TIA |
0.1-5 |
Water |
0-15 |
EXPERIMENTAL RESULTS
[0037] The various soils of TABLES I-IV were tested, generally, by the procedure of cooking
the soil, applying it to dishes or glasses, and allowing it to cool and dry. Thus,
the oatmeal and starch soils were prepared in accordance with their package directions
and/or intended use, spread onto plates, and allowed to dry. Milk and pudding soils
were cooked into beakers, and allowed to dry. Soil removal was visually graded, against
photographic standards, on a scale of 1 to 10, with 10 being complete removal of soil.
All soil removal evaluations herein were performed after one wash cycle.
[0038] Machine dishwashing filming and spotting evaluated in Tables I-IV was measured by
ASTM Tentative Method D3556-76T (CSMA DCC-05), the disclosure of which is fully incorporated
by reference herein. To summarize, clean glass tumblers are loaded into an automatic
dishwasher, along with 4 plates, each soiled with 10g of a standard soil comprising
powdered nonfat milk, margarine, and a cereal solution. Thirty grams of detergent
was added to the closed cup for release in the main wash. Typically, the main wash
utilizes 7-12 liters of water, which dissolves the detergent. The wares were washed
in the dishwasher for 5 cycles, with the soils and detergent renewed after each cycle.
The tumblers were rated visually in a light box, on a 5 point scale, for filming and
spotting. The results were scored as follows:
Rating |
Spotting |
Filming |
1 |
glass spotless |
no film |
2 |
spots at random |
barely perceptible |
3 |
1/4 of glass covered with spots |
slight film |
4 |
1/2 of glass covered with spots |
moderate film |
5 |
glass completely covered with spots |
heavy film |
TABLE I compares soil removal of three builders: sodium carbonate, sodium citrate
and an acrylic/maleic copolymer. The effect of high carbonate levels on various soils
is advantageously shown herein. All formulas have 7.5% sodium silicate (SiO₂/Na₂O
= 2.4), 4% low-foaming surfactant (an ethoxylated/propoxylated C₉ aliphatic alcohol),
1% sodium dichloroiscocyanurate, and water. Wash conditions included 30 grams of detergent
added to the main wash, 49°C (120°F) wash water having a 125 ppm water hardness (as
CaCO₃; Ca/Mg = 3).
Tables IIA-B illustrate the beneficial absence of spotting/ filming on wares washed
with the composition herein. The effects of polycarboxylate and TIA on inhibition
of calcium precipitation was measured by evaluating spotting and filming on glassware
washed with two compositions of the present invention. The compositions included Na₂CO₃
(68% in the composition of IIA and 60% in that of II-B), 8% sodium silicate (SiO₂/Na₂O
= 2.4), 4% low-foaming surfactant, 2% sodium dichloroiscocyanurate, with the remainder
water. The Table II-B composition also included 1.4-11.9% Na₂SO₄ filler, and 0.5%
NaOH. Wash conditions were 30 grams of detergent added to the main wash, and 60°C
(140°F)wash water, with the hardness as indicated in each Table. The glasses were
graded after 5 cycles using the ASTM D3556-76T method.
[0039] A comparison of examples 1-4 shows that both polymer and TIA are effective in reducing
filming. Some TIA is, however, necessary to inhibit film formation, as shown by example
7, with no TIA. Example 5 with no polymer, in 100 ppm hardness water, resulted in
a spotting grade of 2.1, not significantly different from the control at the 95% confidence
level. With harder water, however, the absence of polymer results in pronounced spotting,
as seen in example 14. The polymer thus is of greater importance in harder water.
[0040] Table III shows the performance benefit that the high carbonate levels have on soil
removal, with particular emphasis on starch and pudding soil removal, compared to
a phosphorus-containing formula of the art. Also shown is the added soil removal benefit
imparted by the polyacrylate of Formula C on starchy soil removal.
[0042] The formulas of Table V contain about 75% sodium carbonate, 8% sodium silicate (SiO₂/Na₂O
= 2.4), 4% low-foaming surfactant, 2% dichloroisocyanurate, and water. The acrylic
acid polymer had a weight average molecular weight of 2734 g/mole. Water hardness
was 250 ppm as CaCO₃ (Ca/Mg = 3). All solutions were kept at 49°C (120°F) in a heated
water bath.
[0043] Examples 1-4 of Table V, without polymer, resulted in relatively high turbidities,
indicating the presence of calcium precipitates. Example 5, having no TIA, similarly
yielded a high turbidity, while Examples 6-9 resulted in acceptably low turbidities.
[0045] The formulas of Table VI, above, also contain about 8% sodium silicate (SiO₂/Na₂O
= 2.4), 4% low-foaming surfactant, 2% dichloroisocyanurate, and water. Water hardness
was 400 ppm as CaCO₃ (Ca/Mg = 3). All solutions were kept at 60°C (140°F) in a heated
water bath.
Table VII exemplifies an appropriate molecular weight range of effectiveness of the
polymers herein. It can be seen that acceptable turbidities result from the use of
sodium polyacrylate with a molecular weight range of about 2000-5800. At a molecular
weight of 20,000, however, the turbidity increases, indicating observable calcium
precipitation.
1. A dry detergent composition for use in an automatic dishwasher comprising
(a) 40-80% of an alkali-metal carbonate as the sole builder;
(b) 2-10% of an alkali-metal silicate, having a SiO₂/M₂O ratio of between 1 and 4;
(c) a low-foaming surfactant; and
(d) a calcium crystal growth-inhibiting amount of an inhibitor system, comprising
0.1-10% of a polycarboxylic acid or salt selected from the group consisting of polyacrylic
or polymethacrylic acids having a molecular weight of between 1,000 and 10,000 g/mole;
and 0.1-5% of a threshold inhibiting agent selected from the group consisting of poly-phosphonates/carboxylates
of mono-, di, and trialkylamines having at least one phosphonate group; 1- hydroxyethylidene-1,1-diphosphonic
acid; aminotri(methylenephosphonic acid); 2-phosphonobutane-1,2,4- tricarboxylic acid;
phosphonohydroxy acetic acid; and mixtures thereof.
2. A composition as claimed in claim 1 characterized in that the low-foaming surfactant
is selected from the group consisting of C₁₋₄ alkoxylated aliphatic alcohols, C₁₋₄
alkoxylated alkyl phenols, copolymers of C₁₋₄ alkylene oxides and mixtures thereof.
3. A composition as claimed in claim 1 or claim 2 characterized in that it further includes
a bleachingeffective amount of a bleach.
4. A composition as claimed in any of claims 1-3 characterized in that the surfactant
is an ethoxylated or propoxylated C₈₋₁₄ aliphatic alcohol.
5. A composition as claimed in any of claims 1-4 characterized in that the alkali-metal
carbonate is sodium carbonate and the alkali-metal silicate is sodium silicate having
a SiO₂/M₂O ratio of 3.2.
6. An automatic dishwashing detergent composition as claimed in claim 1 consisting essentially
of
(a) 60-80% of a sodium carbonate as the sole builder;
(b) 5-10% of a sodium silicate having a SiO₂/M₂O ratio of between 1 and 4;
(c) 3-8% of a polyacrylic acid selected from the group consisting of polyacrylic or
polymethacrylic acid having a molecular weight of between 2,000-5,000 g/mole;
(d) 0.3-2% of a threshold inhibiting agent selected from the group consisting of polyphosphonates/carboxylates
of mono-, di-, and trialkylamines having at least one phosphonate group; 1-hydroxyethylidene-1,
1-diphosphonic acid; aminotri- (methylenephosphonic acid); 2-phosphonobutane-1,2,4-
tricarboxylic acid; phosphonohydroxy acetic acid; and mixtures thereof; and
(e) 1-5% of a low foaming non-ionic surfactant.
7. A composition as claimed in claim 6 characterized in that the low-foaming surfactant
is selected from the group consisting of C₁₋₄ alkoxylated aliphatic alcohols, C₁₋₄
alkoxylated alkyl phenols, copolymers of C₁₋₄ alkylene oxides and mixtures thereof.
8. A method for washing wares comprising
contacting the wares with a cleaning effective amount of a detergent composition,
in aqueous solution, as claimed in any of claims 1-7.
1. Trockene Detergenzzusammensetzung für die Verwendung in einer automatischen Geschirrspülmaschine
enthaltend
(a) 40 - 80% Alkalimetallcarbonat als einziger Builder;
(b) 2 - 10% Alkalimetallsilicat mit einem SiO₂/M₂O-Verhältnis zwischen 1 und 4;
(c) ein gering schäumendes grenzflächenaktives Mittel; und
(d) eine Calciumkristall-wachstumsinhibitierende Menge eines Inhibitorsystems enthaltend
0,1 - 10% einer Polycarbonsäure oder eines Salzes, ausgewählt aus der Gruppe bestehend
aus Polyacryl- oder Polymethacrylsäuren, mit einem Molekulargewicht zwischen 1.000
und 10.000 g/mol; und 0,1 bis 5% Schwelleninhibitormittel, ausgewählt aus der Gruppe
bestehend aus Polyphosphonaten/Carboxylaten von Mono-, Diund Trialkylaminen, mit mindestens
einer Phosphonatgruppe; 1-Hydroxyethyliden-1,1-diphosphonsäure; Aminotri(methylenphosphonsäure);
2-Phosphonbutan-1,2,4-tricarbonsäure; Phosphonhydroxyessigsäure; und Gemische davon.
2. Zusammensetzung nach Anspruch 1, dadurch gekennzeichnet, daß das gering schäumende grenzflächenaktive Mittel ausgewählt wird aus der Gruppe
bestehend aus C₁₋₄-alkoxylierten aliphatischen Alkoholen, C₁₋₄- alkoxylierten Alkylphenolen,
Copolymeren von C₁₋₄-Alkylenoxiden und deren Gemischen.
3. Zusammensetzung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß sie zusätzlich eine bleichwirksame Menge eines Bleichmittels enthält.
4. Zusammensetzung nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß das grenzflächenaktive Mittel ein ethoxylierter oder propoxylierter C₈₋₁₄- aliphatischer
Alkohol ist.
5. Zusammensetzung nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß das Alkalimetallcarbonat Natriumcarbonat ist und das Alkalimetallsilicat Natriumsilicat
mit einem SiO₂/M₂O-Verhältnis von 3,2 ist.
6. Detergenzzusammensetzung für eine automatische Geschirrspülmaschine nach Anspruch
1, bestehend im wesentlichen aus
(a) 60 - 80% Natriumcarbonat als einziger Builder;
(b) 5 - 10% Natriumsilicat mit einem SiO₂/M₂O-Verhältnis zwischen 1 und 4;
(c) 3 - 8% einer Polyacrylsäure, ausgewählt aus der Gruppe bestehend aus Polyacryl-
oder Polymethacrylsäure mit einem Molekulargewicht zwischen 2.000 - 5.000 g/mol;
(d) 0,3 - 2% eines Schwelleninhibitormittels, ausgewählt aus der Gruppe bestehend
aus Polyphosphonaten/Carboxylaten von Mono-, Di- und Trialkylaminen mit mindestens
einer Phosphonatgruppe; 1-Hydroxyethyliden-1,1-diphosphonsäure; Aminotri(methylenphosphonsäure);
2-Phosphonbutan- 1,2,4-tricarbonsäure; Phosphonhydroxyessigsäure; und Gemischen davon;
und
(e) 1 - 5% eines gering schäumenden nicht-ionischen grenzflächenaktiven Mittels.
7. Zusammensetzung nach Anspruch 6, dadurch gekennzeichnet, daß das gering schäumende grenzflächenaktive Mittel ausgewählt wird aus der Gruppe
bestehend aus C₁₋₄-alkoxylierten aliphatischen Alkoholen, C₁₋₄- alkoxylierten Alkylphenolen,
Copolymeren aus C₁₋₄-Alkylenoxiden und deren Gemischen.
8. Verfahren zum Waschen von Waren durch Behandlung der Waren mit einer für die Reinigung
wirksamen Menge einer Detergenzzusammensetzung in wäßriger Lösung nach einem der Ansprüche
1 bis 7.
1. Composition détergente sèche à utiliser dans un lave-vaisselle automatique, comprenant
(a) 40-80 % d'un carbonate de métal alcalin comme seul adjuvant;
(b) 2-10 % d'un silicate de métal alcalin dont le rapport SiO₂/M₂O est compris entre
1 et 4:
(c) un agent tensioactif peu moussant; et
(d) une quantité inhibitrice de la croissance des cristaux de calcium d'un système
inhibiteur, comprenant 0,1-10 % d'un acide polycarboxyliquc ou d'un de ses sels choisi
dans le groupe constitué par les poly(acides acryliques) ou poly(acides méthacryliques)
ayant une masse moléculaire comprise entre 1 000 et 10 000 g/mole; et 0,1-5 % d'un
agent séquestrant choisi dans le groupe constitué par les polyphosphonates/carboxylates
de mono-, di- et trialkylamines ayant au moins un groupe phosphonate; l'acide 1-hydroxyéthylidène-1,1-diphosphonique;
l'acide aminotri- (méthylènephosphonique); l'acide 2-phosphonobutane-1,2,4-tricarboxylique;
l'acide phosphonohydroxyacétique; et leurs mélanges.
2. Composition selon la revendication 1, caractérisée en ce que l'agent tensioactif peu
moussant est choisi dans le groupe constitué par des alcools aliphatiques substitués
par des groupes alcoxy en C₁-C₄, des alkylphénols substitués par des groupes alcoxy
en C₁-C₄, des copolymères d'oxydes d'alkylène en C₁-C₄ et leurs mélanges.
3. Composition selon la revendication 1 ou la revendication 2, caractérisée en ce qu'elle
contient en outre une quantité efficace pour le blanchiment d'un agent de blanchiment.
4. Composition selon l'une quelconque des revendications 1-3, caractérisée en ce que
l'agent tensioactif est un alcool aliphatique en C₈-C₁₄ éthoxylé ou propoxylé.
5. Composition selon l'une quelconque des revendications 1-4, caractérisée en ce que
le carbonate de métal alcalin est le carbonate de sodium et en ce que le silicate
de métal alcalin est un silicate de sodium dont le rapport SiO₂/M₂O est de 3,2.
6. Composition détergente pour lave-vaisselle automatique selon la revendication 1, constituée
essentiellement de
(a) 60-80 % d'un carbonate de sodium comme seul adjuvant;
(b) 5-10 % d'un silicate de sodium dont le rapport SiO₂/M₂O est compris entre 1 et
4;
(c) 3-8 % d'un poly(acide acrylique) choisi dans le groupe constitué par les poly(acides
acryliques) ou poly(acides méthacryliques) ayant une masse moléculaire comprise entre
2 000 et 5 000 g/mole;
(d) 0,3-2 % d'un agent séquestrant choisi dans le groupe constitué par les polyphosphonates/carboxylates
de mono-, di- et trialkylamines ayant au moins un groupe phosphonate; l'acide 1-hydroxyéthylidène-1,1-diphosphonique;
l'acide aminotri(méthylènephosphonique); l'acide 2-phosphonobutane-1,2,4- tricarboxylique;
l'acide phosphonohydroxyacétique; et leurs mélanges; et
(e) 1-5 % d'un agent tensioactif non ionique peu moussant.
7. Composition selon la revendication 6, caractérisée en ce que l'agent tensioactif peu
moussant est choisi dans le groupe constitué par des alcools aliphatiques substitués
par des groupes alcoxy en C₁-C₄, des alkylphénols substitués par des groupes alcoxy
en C₁-C₄, des copolymères d'oxydes d'alkylène en C₁-C₄ et leurs mélanges.
8. Méthode pour laver la vaisselle comprenant la mise en contact de la vaisselle avec
une quantité efficace pour le nettoyage d'une composition détergente selon l'une quelconque
des revendications 1-7 en solution aqueuse.