Alkaline liquid hard-surface cleaning composition containing a quaternary ammonium disinfectant and selected dicarboxylate sequestrants

Disclosed is a alkaline liquid hard-surface cleaning and disinfecting composition. The composition comprises from about 0.001% to about 5% by weight of a C.sub.4 -C.sub.7 dicarboxylate or hydroxydicarboxylate, from about 0.005% to about 5% by weight of a quaternary ammonium disinfectant, from about 0.001% to about 15% by weight of a detergent surfactant, a pH of from about 7.5 to about 13, from about 15% to 98% by weight of water, and from 0 to about 60% by weight of an organic solvent having a hydrogen bonding parameter of less than about 7.7. The composition can be used to provide streak-free cleaning and disinfecting of hard surfaces. Moreover, in the presence of the selected dicarboxylates, the quaternary ammonium disinfectant retains its disinfectancy properties and does not precipitate out of solution. The composition can be prepared as a dry formulation.

FIELD OF THE INVENTION
 This invention relates to a stable, alkaline liquid hard-surface cleaning
 composition which contains a quaternary ammonium disinfectant and selected
 dicarboxylate sequestrants.
 BACKGROUND OF THE INVENTION
 Alkaline liquid hard-surface cleaning compositions, including those which
 contain hard water sequestrants, are well known. The alkalinity provides
 improved grease cleaning properties but often necessitates the use of
 sequestrants. In alkaline compositions, divalent cations, e.g., Mg.sup.++,
 Ca.sup.++, react with carbonates and other anionic species in hard water
 and form solid precipitates. These precipitates can form on hard surfaces
 thus appearing as a visible film, or within alkaline concentrates when
 diluted with hard tap water prior to use. Sequestrants (e.g., phosphates,
 EDTA, polycarboxylates) are incorporated into alkaline hard-surface
 cleaning compositions to help prevent formation of these insoluble salts.
 The sequestrants bind to the hard water cations to thus prevent the
 formation of insoluble hard water precipitates.
 Acidic, liquid, hard-surface cleaning and disinfecting compositions are
 also well known. These compositions are commonly used to clean and
 disinfect hard bathroom surfaces. Unlike alkaline compositions, these
 acidic compositions can contain quaternary ammonium disinfectants.
 Quaternary ammonium disinfectants are not typically compatible with hard
 water sequestrants in alkaline compositions. Acidic compositions do not
 require a sequestrant since divalent hard water cations do not readily
 form solid precipitates in acidic environments, e.g., there are
 insufficient amounts of anionic species in the acidic compositions to
 react with the divalent cations to form solid precipitates. Without
 sequestrants in the compositions, quaternary ammonium disinfectants can be
 more easily incorporated into the acidic hard-surface cleaning
 compositions. However, the quaternary ammonium disinfectant contributes to
 filming and streaking, and acidic compositions are less effective than
 alkaline compositions in cleaning greasy dirt.
 Given the foregoing, there is a need to provide a stable, alkaline liquid
 hard-surface cleaning composition which contains both a quaternary
 ammonium disinfectant and a sequestrant. It is therefore an object of the
 present invention to provide such a composition. It is a further object to
 provide such a composition which also does not cause filming or streaking
 on hard surfaces.
 SUMMARY OF THE INVENTION
 The present invention relates to an alkaline liquid hard-surface cleaning
 composition comprising (1) from about 0.001% to about 15%, preferably from
 about 0.005% to about 10% by weight of a C.sub.4 to C.sub.7 dicarboxylate
 sequestrant, which has at least one hydroxyl group; (2) from about 0.005%
 to about 10%, preferably from about 0.005% to about 5% by weight of a
 quaternary ammonium disinfectant; (3) from about 0.001% to about 15% by
 weight of a zwitterionic or nonionic detergent surfactant, or a mixture
 thereof; a pH of from about 8.5 to about 13; (4) from about 15% to about
 98% by weight of water; and (5) from 0 to about 60%, preferably from about
 5% to about 20%, by weight of an organic solvent having a hydrogen bonding
 parameter of less than about 7.7. The composition can be used to provide
 streak-free cleaning and disinfecting of hard surfaces. The quaternary
 ammonium disinfectant is neither inactivated nor precipitated by the
 selected dicarboxylate sequestrants. It is well known that quaternary
 ammonium disinfectants are not normally compatible with sequestrants in
 alkaline hard-surface cleaners and that such disinfectants and
 sequestrants cause excessive filming and streaking of hard surfaces.
 All ratios, parts and percentages herein are based on weight unless
 otherwise specified.
 DETAILED DESCRIPTION OF THE INVENTION
 The alkaline liquid hard-surface cleaning composition of the present
 invention contains a unique combination of a quaternary ammonium
 disinfectant and a selected dicarboxylate sequestrant.
 Sequestrant
 Surprisingly, the selected dicarboxylate sequestrants for use in the
 alkaline liquid composition of the present invention do not precipitate or
 inactivate quaternary ammonium disinfectants. We tested mono-, di- and
 tricarboxylates, and well-known sequestrants (e.g., phosphates, EDTA,
 DTPA, polycarboxylate polymers) for sequestering ability and compatibility
 with quaternary ammonium disinfectants in alkaline compositions. Only the
 C.sub.4 -C.sub.7 dicarboxylates having at least one hydroxyl group,
 described herein, exhibited good sequestering properties and good filming
 and streaking properties and were chemically stable in the presence of a
 quaternary ammonium disinfectant in an alkaline composition.
 To demonstrate the compatibility of the selected dicarboxylate sequestrants
 herein with quaternary ammonium disinfectants, the following tests were
 conducted. Several alkaline solutions (pH 9.8) were prepared, each having
 the following formula but a different "Test Material" (see Table 1 for
 description of Test Materials).

EXAMPLES
 The hard-surface cleaning compositions of the present invention are
 illustrated by the following example. Values are weight percents unless
 otherwise specified.

Formula A Formula B Formula C Formula D
 Ingredient (control) (dilute) (concentrate) (dry)
 Isopropanol 6.00 6.00 30.00 00
 Butoxypropanol 3.00 3.00 15.00 00
 Monoethanolamine 0.50 0.50 2.5 00
 VarionCAS 0.16 0.16 0.80 55
 Sulfobetaine
 *Quaternary 0.0 0.10 0.50 15
 ammonium
 disinfectant
 Tartaric acid 0.0 0.50 2.5 30
 Added water Balance Balance Balance 00
 pH 10.8 10.8 9.8 --
 *mixture of n-alkyl dimethyl ethylbenzyl ammonium chloride and n-alkyl
 dimethyl benzyl ammonium chloride
 Formulas B, C, and D are dilute, concentrate and dry compositions,
 respectively, of the present invention. Formula A is a typical alkaline
 hard surface cleaning composition. The following tests were used to
 evaluate the performance of Formulas A, B and C.
 Preparation of Soiled Panels
 Enamel splash panes are selected and cleaned with a mild, light duty liquid
 cleanser, then cleaned with isopropanol, and rinsed with distilled or
 deionized water. A specified amount (0.05-0.75 gm/plate) of greasy
 particulate soil is weighed out and placed on a sheet of aluminum foil.
 The greasy-particulate soil is a mixture of about 77.8% by weight of
 commercial vegetable oils and about 22.2% by weight of particulate soil
 composed of humus, fine cement, clay, ferrous oxide, and carbon black. The
 soil is spread out with a spatula and rolled to uniformity with a standard
 3-inch wide, one quarter inch nap, paint roller. The uniform soil is then
 rolled onto the clean enamel panels until an even coating is achieved. The
 panels are then placed in a preheated oven and baked at
 130.degree.-150.degree. C. (266.degree. to 302.degree. F.) for 35-90
 minutes. Panels are allowed to cool to room temperature and can either be
 used immediately, or aged for one or more days. The aging produces a
 tougher soil that typically requires more cleaning effort to remove.
 Soil Removal
 A Gardner Straight Line Washability Machine is used to perform the soil
 removal. The machine is fitted with a carriage which holds a weighted
 cleaning implement. The cleaning implements are clean cut sponges. Excess
 water is wrung out from the sponge and 1-10 grams of product are uniformly
 applied to one surface of the sponge. The sponge is fitted into the
 carriage on the Gardner Machine and the cleaning test is run.
 Cleaning Scale
 This method evaluates the cleaning efficiency of test products and compares
 them to that of a reference product. The number of strokes (Gardner
 Machine) necessary to remove 95-99% of the soil is obtained. Then the
 following formula is used to rate cleaning performance {"Soil Removal"
 Scale Rating=[1/#strokes for test product].times.100.times.# strokes for
 reference product}. This yields a value of 100 for the reference product.
 If the test product requires fewer strokes than the reference product, the
 test product will have a Scale Rating value &gt;100. If the test product
 requires more strokes than the standard it will have a Scale Rating value
 &lt;100. Formula A was used as the reference product.

Soil Removal Scale Rating Data
 Formula Mean Rating *
 A 100
 B 170
 C 170
 4 test repetitions, soiled panels aged 2 days
 The difference between mean ratings of 100 and 170 is statistically
 significant at 95% confidence. Therefore, formulas B and C, which contain
 both tartaric acid and a quaternary ammonium disinfectant, are clearly
 better than Formula A, which contains neither tartaric acid nor a
 quaternary ammonium disinfectant, in removing soil.
 Filming/Streaking Test on Glass Panels
 A glass window pane approximately 18.times.23 inches is cleaned with a mild
 detergent to remove any accumulated soil. It is then cleaned repeatedly
 with a blend of isopropanol and propylene glycol monobutylether until no
 visible residue remains on the glass. The glass is then divided into four
 equal sized quadrants with masking tape. Two milliliters of each test
 product are uniformly applied to a quartered paper towel and applied to a
 specified quadrant. The wet paper towel is rubbed uniformly throughout the
 quadrant and the residue is allowed to evaporate.
 Panelists are then called upon to grade filming/streaking of each glass
 panel on the following absolute numerical (0-7) scale.
 0: none (no visible filming/streaking)
 1: mild-none
 2: mild
 3: mild-moderate
 4: moderate
 5: moderate-heavy
 6: heavy (heavy filming/streaking)

Filming/Streaking on Glass Panels
 Panel Score Unit (psu) Ratings
 Formula pair Mean psu Rating*
 A 3.0
 B 0.7
 C 0.75**
 *based on 3 test repetitions
 **diluted with 14 gpg water to a Formula A/B concentration
 The difference between mean psu ratings of 3.0 and 0.7 (and between 3.0 and
 0.75) is statistically significant at 95% confidence. Therefore, formulas
 B and C, which contain both tartaric acid and a quaternary ammonium
 disinfectant, are clearly better than Formula A, which contains neither
 tartaric acid nor a quaternary ammonium disinfectant, in minimizing
 filming/streaking on glass surfaces.
 Germicidal Effectiveness
 The germicidal effectiveness of Formula B against the organisms
 Staphylococcus aureus, Pseudomonas Aeruginosa and Salmonella chloreasuis
 was determined according to the method described in "Official Methods of
 Analysis of the Association of Official Analytical Chemists (AOAC), 12th
 Ed. (1975), pages 59-60. The evaluation was performed on a use dilution of
 1 part of Formula B diluted with 64 parts of water. Formula B received a
 "Germicidal" rating as to each of the above described organisms. Thus, the
 disinfectancy properties of the quaternary ammonium compound in Formula B
 were not "inactivated" by the tartaric acid in the composition.
 Example 2
 The following compounds were tried as builders in the formulation provided
 below. After making the solution, 100 g of the solution was diluted with
 14 gpg water (4:1). These solutions were then stored in a 120.degree. F.
 constant temperature room for 72 hours. The solutions were checked for
 precipitation and for separation and then they were tested for filming and
 streaking.