[0001] This invention relates to formulations for manually washing dishes.
[0002] Light-duty liquid detergent formulations for kitchen surfaces are well known. Kitchen
surfaces include counter tops, stove tops, dishes and any other hard surface commonly
found in kitchen environments. The term "dishes" includes any utensils involved in
food preparation or consumption. Kitchen surfaces, particularly dishes, must be washed
free of food residues, grease, proteins, starches, gums, dyes, oils and burnt organic
residues.
[0003] Most of the consumer accepted formulations in use include anionic synthetic surfactants
with or without a nonionic surfactant. Many of such formulations contain a sulphonate-type
anionic surfactant, for example, an alkylbenzene sulphonate or an alkane sulfonate,
in conjunction with a sulphate or alkyl ether sulphate, or a nonionic surfactant,
for example, an alcohol ethoxylate, an alkyl phenol ethoxylate, a mono- or diethanolamide
or an amine oxide. The sulphonate material generally predominates.
[0004] It is the anionic surfactant that provides the typical high foaming (suds) characteristics
generally associated with dish washing formulations. Foam (suds) is the cleaning efficacy
signal relied on by consumers. Nonionic surfactants generally do not provide good
foaming characteristics.
[0005] It is known from US-A-2,746,928 that it is not possible to mix anionic surface-active
agents with quaternary ammonium germicides. The cationic quaternary ammonium germicide
reacts with the anionic surface-active agent resulting in a reduction in germicidal
and detergent activity.
[0006] Thus anionic surfactants are incompatible with cationic quaternary antimicrobial
surfactants and nonionic surfactants do not normally provide significant foaming capability
to liquid formulations. Therefore current dish washing formulations can only mechanically
eliminate bacteria from kitchen hard surfaces. They are not effective in killing or
controlling the spread of germs throughout the kitchen environment. Thus dish washing
liquids combining good foaming and antimicrobial activities are not available to the
consumer.
[0007] The present invention provides an aqueous disinfecting liquid formulation for cleaning
hard surfaces, particularly dishes, in a kitchen environment; wherein said formulation
is free of anionic surfactants and consisting essentially of:
a) 0.5 to 15 weight percent of a quaternary disinfecting compound;
b) 0.5 to 20, preferably 13 to 14, weight percent of a C₁₂-C₁₃ alcohol ethoxylate
nonionic surfactant;
c) 0.0 to 20, preferably 3 .0 to 5, weight percent of a C₁₃- C₁₅ alcohol ethoxylate
nonionic surfactant;
d) 0.5 to 20.0, preferably 2, weight percent of a nonionic surfactant selected from
the group consisting of cocomonoethanolamide, cocodiethanolamide and combinations
thereof;
e) 0.5 to 12, preferably 3.0 to 9.0, weight percent cocoamidopropyl betaine nonionic
surfactant;
f) 0 to 2.0, preferably 1.0, weight percent of the sodium salts of EDTA.
[0008] This formulation of this invention will control the presence and spread of bacteria
on hard surfaces in the kitchen environment, especially dishes. This invention contains
a microbiologically active quaternary ingredient homogeneously incorporated into a
nonionic aqueous surfactant system. Unexpectedly the formulation has good flash foaming
and residual foaming capability although no anionic surfactants are included. Moreover,
the formulation has excellent viscosity and color stability.
[0009] Optional ingredients can include fragrances, dyes and stabilizers.
[0010] The purpose of the quaternary ammmonium disinfectants is to kill on contact gram
positive and gram negative organisms the organisms encountered in kitchen environments.
Useful disinfectants include BTC 8358 which is N- Alkyl (50% C₁₄, 40% C₁₂, and 10%
C₁₆) dimethyl benzyl ammonium chloride. Other quaternary ammonium salt may be any
of the well-known class of quaternary ammonium germicides characterized by the formula:

wherein at least one of the radicals R₁, R₂, R₃ and R₄ is a hydrophobic, aliphatic,
aryl aliphatic, or aliphatic aryl radical of from 6 to 26 carbon atoms and the entire
cation portion of the molecule has a molecular weight of at least 165. The hydrophobic
radicals may be long-chain alkyl, long-chain alkoxy aryl, long-chain alkyl aryl, halogen-substituted
long-chain alkyl aryl, long-chain alkyl phenoxy alkyl, aryl alkyl, and so forth, in
nature. The remaining radicals on the nitrogen atom other than the hydrophobic radicals
are substituents of hydrocarbon structure usually containing a total of no more than
12 carbon atoms. The radical X in the above formula is any salt-forming anionic radical.
[0011] Suitable quaternary ammonium salts within the above description include the alkyl
ammonium halides such as cetyl trimethyl ammonium bromide, alkyl aryl ammonium halides
such as octadecyl dimethyl benzyl ammonium bromide, N-alkyl pyridinium halides such
as N-cetyl pyridinium bromide, and the like. Other suitable types of quaternary ammonium
salts include those in which the molecule contains either, amide or ester linkages
such as octyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride, N-(laurylcocoaminoformylmethyl)
- pyridinium chloride, and so forth. Other very effective types of quaternary ammonium
germicides are those in which the hydrophobic radical is characterized by a substituted
aromatic nucleus as in the case of lauryloxyphenyltrimethyl ammonium chloride, cetylaminophenyltrimethyl
ammonium methosulfate, dodecylphenyltrimethyl ammonium methosulfate, dodecylbenzyltrimethyl
ammonium chloride, chlorinated dodecylbenzyltrimethyl ammonium chloride, and the like.
[0012] Preferred quaternary ammonium germicides of the above general types are the long-chain
alkyl dimethylbenzyl quaternary ammonium salts, the alkyl phenoxy alkoxy alkyl dimethyl
benzyl quaternary ammonium salts, the N-(acylcocoaminoformylmethyl)pyridinium halides,
the long-chain alkyl trimethyl ammonium halides, the long-chain alkyl benzyl dimethyl
benzyl ammonium halides, and the long-chain alkyl benzyl diethyl ethanol ammonium
halides in which the alkyl radical contains from 8-18 carbon atoms.
[0013] The mechanism of this nonionic system for cleaning standard food and kitchen soils
is through emulsification of the soils. Current anionic light duty liquids solubilize
most food soils. When soil is emulsified within a system, it will affect the type,
density and amount of foam that can be generated. In general, emulsified fatty soils
will reduce the amount of foam that can be generated as further cleaning takes place.
Since anionic systems solubilize soils, the effect on the foam is not as great as
with nonionic systems. Therefore, foam generated from anionic systems is of greater
volume and more stable throughout the cleaning process.
[0014] In general, anionic surfactant systems such as those found in the current light duty
liquids are classified as high foamers. Conversely, nonionic surfactant systems are
classified as low foamers.
[0015] The challenge was to achieve disinfection activity while producing consumer acceptable
foam using a nonionic and cationic surfactant combination. By careful selection and
great experimentation, we have identified a surfactant mixture, expressed in Example
1, Table 1, that produce consumer acceptable foam comparable to commercial dish washing
liquids using anionic detergents. The useful nonionic surfactants have various chain
lengths and degrees of ethoxylation that allow the dish washing liquid to be effective
on a wide range of food soils while providing good flash foam volume as well as moderate
foam stability. This system provides the consumer with effective cleaning on, but
not limited to, greasy food soils, fatty food soils, and oily food soils while maintaining
disinfection.
Example 1-3
[0016] The unexpected foaming properties of the formulations of the invention are illustrated
in these examples. The foaming properties are due to the carefully balanced mix of
nonionic surfactants. The formulations of examples 1-3 are presented in Table 1.
Table I
INGREDIENTS |
Content in the Weight Percent |
|
Example 1 |
Example 2 |
Example 3 |
WATER, D.I |
62.95% |
64.05% |
61.95% |
DISODIUM EDTA |
1.00% |
1.00% |
1.00% |
NEODOL 25-12 |
------ |
4.00% |
3.00% |
NEODOL 23-6.5 |
14.00% |
13.00% |
13.00% |
MACKAM DZ (30%) |
16.70% |
13.60% |
16.70% |
MACKAMIDE C |
3.00% |
------ |
------ |
MONAMID CMA |
------ |
2.00% |
2.00% |
BTC 8358 (80%) |
2.00% |
2.00% |
2.00% |
FRAGRANCE |
0.35% |
0.35% |
0.35% |
24 HR. *VISCOSITY |
610 CPS |
712 CPS |
766 CPS |
6 WEEKS ROOM TEMP. *VISCOSITY |
618 CPS |
728 CPS |
734 CPS |
*Brookfield Model LVT, spindle 3 at 60 rpm |
[0017] The formulations were prepared by adding the ingredients to ambient temperature water
in the order described and mixed until dissolved. Alternatively, if Monamid CMA is
used (examples 2 & 3 above), the mixture is warmed to about 100 °F before the addition
of Monamid CMA to aid dissolution. Other known methods may be used know to those skilled
in the art. The batch can then be cooled down to add any volatile components.
[0018] The chemical name and function of each ingredient in Table I is presented below in
Table II.
Table II
TRADENAME |
CHEMICAL NAME |
FUNCTION |
D.I. WATER |
DEIONIZED WATER |
DILUENT |
MACKAMIDE C |
COCOAMIDE DEA (cocodiethanol amide) |
NONIONIC SURFACTANT |
MONAMID CMA |
COCOAMIDE MEA (cocomonoethanol amide) |
NONIONIC SURFACTANT |
NEOPOL 25-12 |
C₁₃-C₁₅ ALCOHOL ETHOXYLATE |
NONIONIC SURFACTANT |
NEOPOL 23-6.5 |
C₁₂-C₁₃ ALCOHOL ETHOXYLATE |
NONIONIC SURFACTANT |
MACKAM DZ (30-35%) |
COCOAMIDOPROPYL BETAINE |
NONIONIC SURFACTANT |
DISODIUM EDTA |
DISODIUM EDTA |
CHELATOR |
BTC 8358 (80%) |
N-ALKYL DIMETHYL BENZYL AMMONIUM CHLORIDE |
GERMICIDE |
The good foaming capability is established by measuring foam height according to the
Standard Test method for Foaming Properties of Surface-Active Agents, ASTM D1173-53 (Reapproved 1986). The method was modified by using a 500 mL cylinder
as the foam receiver. Foam heights in the foam receiver were taken initially after
the dropping of the solution and at various time intervals thereafter. Foam height
was determined in both unloaded and loaded systems. A loaded system refers to water
in which oil has been added to simulate oils encountered during dish washing. An unloaded
system refers to water to which no oil has been added.
[0019] A second method for measuring foam heights was also utilized. This method, designed
by the Shell Development Co., is entitled
Soil Titration Test for Determination of Foam Performance of Dish washing Detergents. It was published January 1987 as SC:967-87. The method is a procedure to evaluate
the foam performance of detergent formulations in the presence of dish washing soils.
Foam heights are measured as a percent of a standard formulation.

[0020] The formulations of this invention were compared to commercial anionic based dish
washing liquids using the modified ASTM D1173-53 method. In an unloaded soil system,
foam heights ranged from 16 - 19 cm. In a loaded soil system, foam heights ranged
from 13.5 - 15.5 cm. Our invention of a non-ionic compared quite favorably.
Examples 4-6
[0021] The formulation of example 3 was tested using various levels of active BTC 8358 for
antimicrobial activity against
Staphyloccus aureus (ATTC 6538) and
Kleb pneumoniae (ATTC 4352) by a quantitative suspension test. The test was carried out at dilution
of one part formulation to 256 parts of deionized water at room temperature for a
30 second contact time. The test protocol was as follows.
1. Sample Inoculation
[0022]
A. Inoculate 1.0 ml of the test culture into each sample tube. Repeat for organism.
B. Subculture 1.0 ml of the sample after 1-minute and 1.0 ml after 5 minute contact
time.
C. Subculture the sample into 9.0 ml of DIFCO AOAC Letheen Broth. This the 10⁻¹ sample
dilution.
2. Sample Dilutions and Plating
[0023]
A. Plate the 10⁻¹, 10⁻³, and 10⁻⁵ dilutions for each sample/organism/contact time
combination.
1. From the 10⁻¹ dilution:
a. Plate 1.0 ml = 10⁻¹ plate.
b. Pipet and transfer 0.1 ml into 9.9 ml of Letheen Broth = 10⁻³ sample dilution.
2. From the 10⁻³ sample dilution:
a. Plate 1.0 ml = 10⁻³ plate.
b. Pipet and transfer 0.1 ml into 9.9 ml of Letheen Broth = 10⁻⁵ sample dilution.
B. Pour each plate with Tryptic Soy Agar containing polysorbate 80 and lecithin (either
DIFCO or BBL).
C. Incubate the plates for 48hr at 35C.
3. Control Counts: Dilutions and Plating
[0024]
A. Inoculate 1.0 ml of culture into 9.0 ml Letheen Broth.
B. Subculture 1.0 ml of that Letheen tube into 9.0 ml Letheen Broth at 1 minute and
5 minutes exposure. These are the 10⁻¹ dilution tubes for the 1-minute and 5-minute
contact time controls.
C. Plate the 10⁻⁴ and 10⁻⁵ dilutions for each contact time.
1. Pipet 0.1 ml of the 10⁻¹ dilution into 9.9 ml Letheen Broth = 10⁻³.
2. Plate 0.1 ml of the 10⁻³ dilution = 10⁻⁴ plate.
3. Pipet 0.1 ml of the 10⁻³ dilution into 9.9 ml of Letheen Broth = 10⁻⁵ dilution.
4. Plate 1.0 ml of the 10⁻⁵ dilution = 10⁻⁵ plate.
D. Pour the plates with Tryptic Soy Agar containing polysorbate 80 and lecithin.
E. Incubate at 35°C for 48hr.
4. Log Reduction Calculations
[0025]
A. Determine the number of bacteria survivors at each contact time for both the controls
and test samples.
1. Count the number of colonies on the petri dish. The plate is acceptable for counting
with a colony count between 25 and 250.
2. Multiply the number of colonies by the plate dilution factor = the number of surviving
bacteria.
B. Determine the Log Reduction in bacteria for each sample/organism/contact time combination.
Log₁₀ Control Count - Log₁₀ Survivor Count = # Logs of bacteria reduced by the sample.
[0026] The results obtained are presented in Table IV.
TABLE IV
PERCENT OF BACTERIAL REDUCTION AT 30 SECOND CONTACT TIME |
MICROBIOLOGY TEST NUMBER |
% BTC 8358 IN FORMULA (ACTIVE) |
DILUTION |
Percent Reduction of S. Aureus |
Percent Reduction of Kleb. Pneumoniae |
(Control) |
0.00 |
1:256 |
83.1818 |
47.6623 |
1 |
0.50 |
1:256 |
85.4545 |
77.9220 |
2 |
1.00 |
1:256 |
87.2727 |
76.6233 |
3 |
1.50 |
1:256 |
95.0909 |
88.9610 |
4 |
2.00 |
1:256 |
94.1818 |
94.1558 |
5 |
2.50 |
1:256 |
97.6818 |
97.3766 |
7 |
3.00 |
1:256 |
99.4363 |
98.9090 |
8 |
3.50 |
1:256 |
99.8772 |
99.7441 |
9 |
4.00 |
1:256 |
99.992 |
99.8481 |
1. An aqueous disinfecting liquid formulation for cleaning hard surfaces in a kitchen
environment; wherein the formulation is free of anionic surfactants and consisting
essentially of:
a) 0.5 to 15 weight percent of a quaternary disinfecting compound;
b) 0.5 to 20 weight percent of a C₁₂-C₁₃ alcohol ethoxylate nonionic surfactant;
c) 0.0 to 20 weight percent of a C₁₃- C₁₅ alcohol ethoxylate nonionic surfactant;
d) 0.5 to 20.0 weight percent of a nonionic surfactant selected from the group consisting
of cocomonoethanolamide, cocodiethanolamide and combinations thereof;
e) 0.5 to 12 weight percent cocoamidopropyl betaine nonionic surfactant;
f) 0 to 2.0 weight percent of the sodium salts of EDTA.
2. The formulation of claim 1 consisting essentially of
a) 2 weight percent of a quaternary disinfecting compound;
b) 13 to 14 weight percent of a C₁₂-C₁₃ alcohol ethoxylate nonionic surfactant;
c) 3.0 to 5 weight percent of a C₁₃- C₁₅ alcohol ethoxylate nonionic surfactant;
d) 2 weight percent of a nonionic surfactant selected from the group consisting of
cocomonoethanolamide, cocodiethanolamide and combinations thereof;
e) 3.0 to 9.0 weight percent cocoamidopropyl betaine nonionic surfactant;
f) 1.0 weight percent of the sodium salts of EDTA.
3. The formulation of claim 1 or 2 wherein the quaternary disinfecting compound is alkyl
(50% C¹⁴, 40% C₁₂ and 10% C₁₆) dimethyl benzyl ammonium chloride.
4. The formulation of any one of the preceding claims having a viscosity of 250 to 1000
CPS.
5. The formulation of any one of the preceding claims having a viscosity of 250 to 800
CPS.
6. A method of manually washing hard surfaces in a kitchen environment, comprising the
steps of:
a) providing a disinfecting liquid according to any one of the preceding claims;
b) diluting the liquid with water; and
c) contacting the surfaces with the diluted formulation.