U.S. patent application number 10/267170 was filed with the patent office on 2003-07-31 for pre-moistened wipe comprising polymeric biguanide for treating a surface.
This patent application is currently assigned to The Procter & Gamble Company. Invention is credited to Barnabas, Mary Vijayarani, Sherry, Alan Edward, Wolff, Ann Margaret.
Application Number | 20030143909 10/267170 |
Document ID | / |
Family ID | 23279099 |
Filed Date | 2003-07-31 |
United States Patent
Application |
20030143909 |
Kind Code |
A1 |
Barnabas, Mary Vijayarani ;
et al. |
July 31, 2003 |
Pre-moistened wipe comprising polymeric biguanide for treating a
surface
Abstract
The present invention relates to a pre-moistened wipe for
treating a surface, said pre-moistened wipe comprising: (a) a
substrate; wherein said substrate is substantially free of a binder
or latex material and said; and (b) a composition applied to said
substrate, said composition having (i) a pH of about 7 or less and
comprising (ii) at least about one surfactant; and (iii) a
polymeric biguanide.
Inventors: |
Barnabas, Mary Vijayarani;
(West Chester, OH) ; Sherry, Alan Edward;
(Cincinnati, OH) ; Wolff, Ann Margaret;
(Cincinnati, OH) |
Correspondence
Address: |
THE PROCTER & GAMBLE COMPANY
INTELLECTUAL PROPERTY DIVISION
WINTON HILL TECHNICAL CENTER - BOX 161
6110 CENTER HILL AVENUE
CINCINNATI
OH
45224
US
|
Assignee: |
The Procter & Gamble
Company
|
Family ID: |
23279099 |
Appl. No.: |
10/267170 |
Filed: |
October 9, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60328008 |
Oct 9, 2001 |
|
|
|
Current U.S.
Class: |
442/123 |
Current CPC
Class: |
C11D 3/3792 20130101;
A47L 13/20 20130101; C11D 3/3723 20130101; B05B 9/0861 20130101;
Y10T 442/689 20150401; C11D 17/049 20130101; A47L 13/51 20130101;
C11D 1/662 20130101; C11D 3/48 20130101; C11D 1/72 20130101; A47L
13/22 20130101; C11D 1/825 20130101; C11D 3/2086 20130101; C11D
3/43 20130101; C11D 3/2082 20130101; B05B 9/0866 20130101; Y10T
442/2525 20150401; C11D 3/323 20130101; Y10T 442/2484 20150401;
Y10T 442/692 20150401; A47L 13/256 20130101 |
Class at
Publication: |
442/123 |
International
Class: |
B32B 005/02; B32B
027/04; B32B 027/12 |
Claims
What is claimed is:
1. A pre-moistened wipe for treating a surface, said pre-moistened
wipe comprising: (a) a substrate; wherein said substrate is
substantially free of a binder or latex material; and (b) an
aqueous composition applied to said substrate, said composition
having a pH of about 7 or less; and comprising: (i) at least one
surfactant; and (ii) a polymeric biguanide.
2. The pre-moistened wipe of claim 1 wherein said substrate is made
by a hydroentangling process.
3. The pre-moistened wipe of claim 1 wherein said surfactant is an
alkyl polyglycoside, wherein said substrate comprises at least
about 50% synthetic fibers by weight and wherein the pH of said
composition is from about 5 to about 7.
4. The pre-moistened wipe of claim 1 wherein said composition
comprises an organic acid.
5. The pre-moistened wipe of claim 4 wherein said organic acid is
selected from the group consisting of citric acid, lactic acid,
tartaric acid and mixtures thereof.
6. The pre-moistened wipe of claim 5 wherein said organic acid is
citric acid.
7. The pre-moistened wipe of claim 1 wherein said surfactant is a
low-residue surfactant.
8. The pre-moistened wipe of claim 7 wherein said low-residue
surfactant is selected from the group consisting of zwitterionic,
amphoteric surfactants, non-ionic surfactants comprising at least
one sugar moiety and mixtures thereof.
9. The pre-moistened wipe of claim 8 wherein said low-residue
surfactant is selected from the group consisting of sulfobetaines,
ampho glycinates, ampho propionates, betaines, poly alkyl
glycosides, sucrose esters and mixtures thereof.
10. The pre-moistened wipe of claim 9 wherein said low-residue
surfactant is selected from the group consisting of sulfobetaines,
poly alkyl glycosides, and mixtures thereof.
11. The pre-moistened wipe of claim 1 wherein said surfactant is
selected from the group consisting of alkyl ethoxylates, capped
alkyl ethoxylates and mixtures thereof, wherein said surfactant
comprises from about 8 to about 18 carbon atoms in the hydrophobic
chain-length, and an average of about 1 to about 15 ethoxy moieties
per surfactant molecule.
12. The pre-moistened wipe of claim 1 wherein said polymeric
biguanide is selected from the group consisting of
oligo-hexamethylene biguanide, poly-hexamethylene biguanide, salts
thereof and a mixture thereof.
13. The pre-moistened wipe of claim 12 wherein said polymeric
biguanide is poly(hexamethylene biguanide) hydrochloride.
14. The pre-moistened wipe of claim 1 wherein the level of said
acidifying agent is from about 0.01% to about 3% by weight; the
level of said surfactant is from about 0.01% to about 1.5% by
weight; the level of said polymeric biguanide is from about 0.01%
to about 2% by weight; and the pH of said composition is from about
0.5 to about 7.
15. The pre-moistened wipe of claim 14 wherein the level of said
acidifying agent is from about 0.05% to about 2% by weight; the
level of said surfactant is from about 0.01% to about 1.0% by
weight; the level of polymeric biguanide is from about 0.01% to
about 1.0% by weight; and the pH of said composition is from about
2.0 to about 5.5.
16. The pre-moistened wipe of claim 15 wherein the level of said
acidifying agent is from about 0.1% to about 1% by weight; the
level of surfactant is from about 0.01% to about 0.5% by weight;
the level of said polymeric biguanide is from about 0.02% to about
0.75% by weight; and the pH of the aqueous composition is from
about 2.5 to about 5.
17. The pre-moistened wipe of claim 1 wherein the total level of
solids does not exceed about 3% by weight of said composition.
18. A pre-moistened wipe according to claim 1 that further
comprising from about 0.5% to about 25% by weight of a solvent.
19. The pre-moistened wipe of claim 18 wherein said solvent has a
vapour pressure of about 6.66 Pa (about 0.05 mm Hg at 25.degree. C.
and atmospheric pressure).
20. The pre-moistened wipe of claim 1 that further comprising an
hydrotrope.
21. The pre-moistened wipe of claim 20 wherein said hydrotrope is
an alkyl ethoxylates comprising from about 8 to about 18 carbon
atoms in the hydrophobic group and at least an average of about 15
ethoxylate groups per hydrophobic group.
22. The pre-moistened wipe of claim 1 wherein said substrate is
loaded at a factor of from about 1 gram of aqueous solution per
gram of substrate to about 10 grams of aqueous solution per gram of
substrate.
23. The pre-moistened wipe of claim 1 wherein said substrate
comprises an homogeneous blend of synthetic and non-synthetic
fibers.
24. The pre-moistened wipe of claim 1 wherein said substrate
comprises a non-homogeneous blend of fibers such that at least one
of the visible surface areas of the substrate has a significantly
higher synthetic content than the overall substrate
composition.
25. The pre-moistened wipe of claim 1 wherein the synthetic content
by weight of the overall substrate is at least about 20% preferably
at least about 30%.
26. The pre-moistened wipe of claim 25 wherein said synthetic
material is selected from the group consisting of polyethylene,
polypropylene, polyester and mixtures thereof.
27. The pre-moistened wipe of claim 1, wherein said composition
provides antimicrobial benefits.
28. A method of cleaning a surface, comprising the steps of:
contacting said surface with a pre-moistened wipe according to
claim 1, and wiping said surface with said wipe.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provision
Application No. 60/328,008, filed on Oct. 9, 2001
FIELD OF INVENTION
[0002] The present invention relates to pre-moistened wipes for
treating a surface, in particular to a pre-moistened wipe for
treating a hard surface. The pre-moistened wipe herein incorporates
a substrate and an aqueous composition comprising a polymeric
biguanide. The pre-moistened wipe according to the present
invention was found to exhibit a superior filming/streaking and
shine retention/enhancement profile, as measured using a standard
gloss-meter, whilst providing excellent disinfecting and/or
antimicrobial benefits.
BACKGROUND OF THE INVENTION
[0003] Wipes for treating surfaces are typically pre-moistened,
disposable towelettes which may be utilised in a variety of
applications both domestic and industrial and perform a variety of
functions. Pre-moistened wipes are typically used to wipe surfaces
both animate and inanimate, and may provide numerous benefits such
as cleaning, cleansing, and disinfecting. Pre-moistened wipes
incorporating a cleaning composition are already known in the art.
For example, WO 89/05114 discloses disposable, pre-moistened wipes
for hard surface cleaning, which are impregnated with a liquid
composition. Pre-moistened wipes can also be found in the form of
laminates. In one such embodiment, the laminates include a floor
sheet attached to a reservoir, as described in WO 2000-2000US26401,
incorporated herein by reference.
[0004] One particular application for pre-moistened wipes is
treating hard surfaces, such as, kitchen and bathroom surfaces,
eyeglasses, and surfaces that require cleaning in industry for
example surfaces of machinery or automobiles.
[0005] A commonly known problem in treating hard surfaces is the
formation of films and/or streaks on surfaces treated therewith.
Indeed, after the treatment of a hard surface with a pre-moistened
wipe, the formation of visible residues (streaks) and/or shine
reducing films after drying can often be observed.
[0006] Furthermore, the addition of an antimicrobial agent, to
compositions intended to wipe and clean surfaces, increases the
tendency of filming/streaking on said hard. The filming/streaking
is particularly problematic when treating glossy surfaces, such as
porcelain, chrome and other shiny metallic surfaces, tiles etc.
[0007] It is therefore an object of this invention to provide a
pre-moistened wipe composition that shows a disinfecting or
antimicrobial benefit and a filming/streaking performance benefit
(low or substantially no formation of streak- and/or
film-formation).
[0008] It has now been found that the above objectives can be met
by a pre-moistened wipe for treating a surface, said pre-moistened
wipe comprising: (a) a substrate; wherein said substrate is
substantially free of a binder or latex; and (b) an aqueous
composition applied to said substrate said composition having (i) a
pH of about 7 or less and comprising (ii) at least one surfactant;
and (iii) a polymeric biguanide.
[0009] It is an advantage of the compositions of this invention
that judicious choice of surfactant and pH can result in an
enhancement of tile gloss, either relative to clean untreated
tiles, or tiles treated with a base composition that lacks the
antimicrobial agent.
[0010] It is another advantage of the invention that the preferred
selection of a substrate comprising at least about 20% synthetic
fibers can be used to provide improved cleaning properties over a
range of soils, including greasy stains and soap scum.
[0011] It is yet another advantage of the compositions of this
invention that the pre-moistened wipes can optionally be attached
to a cleaning implement such as a unit comprising a pole and a mop
head.
[0012] Additionally, the antimicrobial compositions herein can be
used to treat shiny and matt hard-surfaces made of a variety of
materials like glazed and non-glazed ceramic tiles, vinyl, no-wax
vinyl, linoleum, melamine, glass, plastics, plastified wood.
BACKGROUND ART
[0013] Aqueous compositions comprising polymeric biguanides are
known in the art. For example, WO 98/56253 discloses a composition
comprising a carrier and a polymeric biguanide compound in the form
of its salt with an organic acid containing from 4 to 30 carbon
atoms such as poly(hexamethylene biguanide) stearate. These
compositions comprising poly(hexamethylene biguanide) exhibit high
antimicrobial, especially antibacterial activity, and exhibit
increased solubility in organic media, especially organic liquids.
U.S. Pat. No. 5,141,803 discloses compositions for use in hard
surfaces comprising biguanide compounds. EP 0 185 970 describes
liquid disinfectant preparations for use on hard surfaces
comprising specific oligo-hexamethyl biguanides, specific
microbiocidally active phenolic compounds and, optionally builders.
U.S. Pat. No. 6,045,817 discloses an antibacterial cleaning
composition (pH>7.5) comprising (1) 0.05%-1% of a cationic
polymer having a charge density of 0.0015 or higher, (2) 0.2-5% of
a zwitterionic surfactant, and (3) 0.2-5% of a biguanide
compound.
[0014] Pre-moistened wipes comprising antimicrobial actives are
known in the art. For example, WO 00/00106 discloses a method for
obtaining effective residual antimicrobial activity on hard
surfaces with an antimicrobial composition that comprises an
organic acid and a surfactant. WO 97/16066 discloses homogeneous
antimicrobial compositions and antimicrobial wet wipes and lotions
that include the antimicrobial compositions. The antimicrobial
composition includes at least 50% water and an effective amount of
a hydrophobic antimicrobial agent.
[0015] Wipes containing biguanide agents are also disclosed in the
patent literature: U.S. Pat. No. 5,993,840 discloses a composition
comprising a cellulosic non-woven material containing a mixture of
polymeric biguanides, such as poly(hexamethylene biguanide)
together with an anionic polymer such as polyacrylic acid
super-absorbent.
SUMMARY OF THE INVENTION
[0016] The present invention relates to a pre-moistened wipe for
treating a surface, said pre-moistened wipe comprising: (a) a
substrate; wherein said substrate is substantially free of a binder
or latex material; and (b) an aqueous composition applied to said
substrate or used in conjunction with said disposable cleaning pad,
said composition having (i) a pH of about 7 or less, and comprising
(ii) at least one surfactant; and (iii) a polymeric biguanide. The
compositions simultaneously deliver excellent filming/streaking
properties on a variety of hard surfaces and high biocidal
effectiveness against relevant Gram positive and Gram negative
organisms found in consumer homes, public domains, and commercial
establishments.
[0017] Accordingly, the pre-moistened wipe compositions of the
present invention are preferably used for wiping and cleaning
various surfaces, preferably hard surfaces.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Definitions
[0019] By `substrate` or `wipe` it is meant any woven or non-woven
material formed as a single structure during the manufacturing, or
present in the form of two or more material laminates.
[0020] By `pre-moistened wipe` it is meant herein a substrate and
an aqueous composition as described herein applied to said
substrate.
[0021] By `synthetic material` or `synthetic fibers`, it is meant
herein a hydrophobic material based on synthetic organic
polymers.
[0022] By `binder` or `latex`, it is meant any additive or
treatment intended to provide strength, integrity, cohesion, or
adhesion of fibers in a web and in process. The term includes fiber
finishes that can be removed by soaking the web in an aqueous
composition comprising either glycol ether solvents and/or C2-C4
alcohols.
[0023] By `substantially free of a binder or latex material` it is
meant herein that the substrate comprises less than about 10%,
preferably less than about 5%, more preferably less than about 1%,
still more preferably less than about 0.5%, and most preferably, no
binder or latex material.
[0024] Substrate
[0025] The substrate herein can be made of synthetic or
non-synthetic fibers. Synthetic materials, as used herein, include
all polymers derived from polyethylene, polypropylene, polyester
polymers and mixtures thereof.
[0026] The composition of the substrate can vary from 100%
synthetic to 100% non-synthetic. While substrates with high
synthetic content tend to release more aqueous lotion, the
Applicant has found that the compositions of the present invention
substantially or completely prevent the increased filming and
streaking that is expected to result from increased solution
release on hard surfaces. As a result, increased load factors can
be used without concern.
[0027] In a preferred embodiment, the substrate herein is made of
from at least about 20%, preferably at least about 30%, even more
preferably at least about 35%, still more preferably at least about
40%, yet still more preferably at least about 50% and most
preferably at least about 60% synthetic material.
[0028] In another preferred embodiment, the substrate herein is
made of up to about 95%, preferably up to about 90%, even more
preferably up to about 85%, still more preferably up to about 80%,
yet still more preferably up to about 75% and most preferably up to
about 70% synthetic material.
[0029] Preferably, the synthetic material herein is selected from
the group consisting of polyethylene, polyethylene terephthalate,
polypropylene, and polyester and mixtures thereof. More preferably,
the synthetic material herein is selected from the group consisting
of polyethylene, polypropylene, polyester and mixtures thereof.
Most preferably, the synthetic material herein is polypropylene or
polyester.
[0030] Furthermore, the substrate herein may comprise any amount of
non-synthetic material. In a preferred embodiment, the substrate
herein is made of from 0% to about 80%, more preferably about 5% to
about 75%, even more preferably about 10% to about 70% still more
preferably about 10% to about 65% and most preferably about 20% to
about 60% non-synthetic material.
[0031] The distribution of synthetic and non-synthetic fibers
within the substrate web can be homogeneous or non-homogeneous.
When the distribution of fibers is non-homogeneous, it is preferred
that the exposed (top and bottom) surface areas of the wipes
comprise a higher amount of synthetic fiber than is present in the
overall substrate composition. Such a structure keeps a reservoir
of fluid within the more absorbent non-synthetic structure, and
sandwiched between the two areas of the wipe that are more
hydrophobic; this results in more controlled release of the aqueous
composition and better overall mileage for the wipe. Alternatively,
the distribution of fibers can advantageously be made so that only
one face of the substrate has more hydrophobic fibers than that of
the overall composition. In this case, the substrate would be
sided, providing one smooth surface with increased synthetic
content, and a more draggy surface made of cellulose or treated
cellulose derivatives. The presence of increased hydrophobic
material at the surface(s) of the substrate also is shown to
improve the lubricity or glide of the substrate as it is wiped
across a variety of hard surfaces. This can provide reassurance of
"easy cleaning" in the context of a consumer goods product.
[0032] Whilst it is found that filming and/or streaking results do
not depend on the specific amounts of synthetic and non-synthetic
materials, the Applicant has found that in a particularly preferred
embodiment, additional cleaning benefits can be achieved when the
substrate comprises at least about 20% synthetic fibers. Even
higher levels of synthetic fibers can be advantageous for further
cleaning benefits.
[0033] Whilst not being bound by theory, it is believed that
hydrophobic-hydrophobic interactions between substrate and soil
account for improved removal of greasy soils. Thus, saturated and
unsaturated oils, fatty acids, oxidized oils and polymerized grease
are all removed with enhanced ease and thoroughness by a wipe that
compositionally has a significant synthetic component. Further, the
benefits of the synthetic component of the substrate go beyond just
the cleaning of pure greasy stains. It is found that the
hydrophobic component of the substrate increases removal of complex
soils in which the oils or other greasy components are present even
if they represent minority components of the overall soil mixture.
In this respect, the use of substrate comprising at least about 20%
synthetic component is advantageous for the cleaning of common
soils that occur in kitchens, bathrooms and elsewhere in consumers'
homes including floors.
[0034] Suitable non-synthetic materials are man-made fibers and
natural fibers. The term man-made fiber, as used herein, denotes
fibers manufactured from cellulose, either derivative or
regenerated. They are distinguished from synthetic fibers, which
are based on synthetic organic polymers. A derivative fiber, as
used herein, is one formed when a chemical derivative of a natural
polymer, e.g., cellulose, is prepared, dissolved, and extruded as a
continuous filament, and the chemical nature of the derivative is
retained after the fiber formation process. A regenerated fiber, as
used herein, is one formed when a natural polymer, or its chemical
derivative, is dissolved and extruded as a continuous filament, and
the chemical nature of the natural polymer is either retained or
regenerated after the fiber formation process. Typical examples of
man made fibers include: regenerated viscose rayon and cellulose
acetate. Preferred man-made fibers have a fineness of about 0.5
dtex to about 3.0 dtex, more preferably of about 1.0 dtex to about
2.0 dtex, most preferably of about 1.6 dtex to about 1.8 dtex.
[0035] Suitable, natural fibers are selected from the group
consisting of wood pulp, cotton, hemp, and the like. Man-made
fibers are preferred herein due to their high consumer acceptance
and their cheap and typically ecological production. Importantly,
man-made fibers and in particular cellulose derived man-made fibers
exhibit a high biodegradability, hence are environment friendly
after disposal. Natural fibers can be preferred because they do not
require the modifications needed to create the man-made fibers. As
such natural fibers can provide cost advantages.
[0036] In a preferred embodiment according to the present
invention, the man-made fiber for use in the substrate herein is a
hydrophilic material, such as Tencel.RTM. rayon, Lenzing AG
rayon.RTM., micro-denier rayon, and Lyocell.RTM.. Hydrophilic
man-made fiber material, when at least partially present in the
substrate herein, has been found to allow for increased loading
factor (described hereinafter) of the aqueous chemical composition
applied to the substrate. Indeed, it has been found that a man-made
fiber-containing substrate can incorporate more aqueous cleaning
composition than a purely synthetic substrate. Furthermore, it has
been found that a pre-moistened wipe comprising man-made fiber
shows a slower release of the composition impregnated thereon
during use as compared to a purely synthetic substrate. By slower
releasing said composition, the area that can be treated with the
pre-moistened wipe is significantly increased. Additionally, the
slower release ensures improved even-ness of solution distribution
and coverage over the surfaces treated.
[0037] Suitable, man-made fibers are commercially available under
the trade name Lyocell.RTM. fibers that are produced by dissolving
cellulose fibers in N-methylmorpholine-N-oxide and which are
supplied by Tencel Fibers Europe, UK.
[0038] Preferred man made fibers used for the present invention are
selected from the group consisting of viscose rayon, high
absorbency rayon, Tencel.RTM. rayon, Lenzing AG rayon.RTM. and
mixtures thereof. It is understood that the specific choice of
rayon type will depend on the desired cleaning and absorbency
characteristics and associated costs. More preferably, the man made
fibers used for the present invention are selected from the group
consisting of viscose rayon and high absorbency rayon.
[0039] The substrate herein is provided in the form of a web,
typically as a sheet of material cut from the web. Said web may be
made of the sheets of material from which the wipes are produced,
preferably cut. The web may be woven or non-woven, comprising
either synthetic, non-synthetic material, or mixtures of synthetic
and non-synthetic material; in a preferred embodiment, the web is a
non-woven comprising at least 20% synthetic material.
[0040] According to the present invention, the sheet may be
produced by any method known in the art. For example non-woven
material substrates can be formed by dry forming techniques such as
air-laying or wet laying such as on a papermaking machine. Other
non-woven manufacturing techniques such as hydroentangling, melt
blown, spun bonded, needle punched and methods may also be used.
However, the substrate must be made substantially free of binder of
latex. Many manufacturing techniques, such as air-laying, do not
lend themselves to the formation of binder- and latex-free
substrates. As such they are not preferred manufacturing
techniques.
[0041] The substrate preferably has a weight of from about 20
gm.sup.-2 to about 200 gm.sup.-2. More preferably, the substrate
has a weight of at least about 20 gm.sup.-2 and more preferably
less than about 150 gm.sup.-2, more preferably the base weight is
in the range of about 20 gm.sup.-2 to about 120 gm.sup.-2, and most
preferably from about 30 gm.sup.-2 to about 110 gm.sup.-2. The
substrate may have any caliper. Typically, when the substrate is
made by hydroentangling, the average substrate caliper is less than
about 1.2 mm at a pressure of about 0.1 pounds per square inch.
More preferably the average caliper of the substrate is from about
0.1 mm to about 1.0 mm at a pressure of about 0.1 pounds per square
inch (about 0.007 kilograms per square meter). The substrate
caliper is measured according to standard EDANA nonwoven industry
methodology, reference method #30.4-89.
[0042] In addition to the fibers used to make the substrate, the
substrate can comprise other components or materials added thereto
as known in the art, including opacifying agents, for example
titanium dioxide, to improve the optical characteristics of the
substrate.
[0043] The substrate herein is substantially free, preferably free,
of a binder or latex material. Preferably, that substrate herein is
substantially free, preferably free, of a binder and latex
material. Substantial elimination of binders and latexes, and the
like, can be accomplished by pre-washing the dry substrate in soft,
distilled or de-ionized water or other solvents, or by using a
process, such as hydroentangling. More specifically, in the
hydroentangling process, a fibrous web is exposed subjected to
high-velocity water jets, preferably employing de-ionized,
distilled or soft water that entangle the fibers. The non-woven
material may then be subjected to conventional drying and wind-up
operations, as known to those skilled in the art. Since the
hydroentangling process precludes the use of binders, and can be
used to wash off fiber latexes, it is the most preferred process to
be used in the manufacture of substrates of the present
invention.
[0044] According to a preferred embodiment of the present invention
the pre-moistened wipe comprises a substrate with a composition as
described herein applied thereon. By "applied" it is meant herein
that said substrate is coated or impregnated with a liquid
composition as described herein.
[0045] In preparing pre-moistened wipes according to the present
invention, the composition is applied to at least one surface of
the substrate material. The composition can be applied at any time
during the manufacture of the pre-moistened wipe. Preferably the
composition can be applied to the substrate after the substrate has
been dried. Any variety of application methods that evenly
distribute lubricious materials having a molten or liquid
consistency can be used. Suitable methods include spraying,
printing, (e.g. flexographic printing), coating (e.g. gravure
coating or flood coating) extrusion whereby the composition is
forced through tubes in contact with the substrate whilst the
substrate passes across the tube or combinations of these
application techniques. For example spraying the composition on a
rotating surface such as calender roll that then transfers the
composition to the surface of the substrate. The composition can be
applied either to one surface of the substrate or both surfaces,
preferably both surfaces. The preferred application method is
extrusion coating.
[0046] The composition can also be applied uniformly or
non-uniformly to the surfaces of the substrate. By non-uniform it
is meant that for example the amount, pattern of distribution of
the composition can vary over the surface of the substrate. For
example some of the surface of the substrate can have greater or
lesser amounts of composition, including portions of the surface
that do not have any composition on it. Preferably however the
composition is uniformly applied to the surfaces of the wipes.
[0047] Preferably, the composition can be applied to the substrate
at any point after it has been dried. For example the composition
can be applied to the substrate prior to calendering or after
calendering and prior to being wound up onto a parent roll.
Typically, the application will be carried out on a substrate
unwound from a roll having a width equal to a substantial number of
wipes it is intended to produce. The substrate with the composition
applied thereto is then subsequently perforated utilizing standard
techniques in order to produce the desired perforation line.
[0048] The composition is typically applied in an amount of from
about 1 g to about 10 g per gram of substrate (load factor=about 1-
about 10.times.), preferably from about 1.5 g to about 8.5 g per
gram of substrate, most preferably from about 2 g to about 7 g per
gram of dry substrate. One of the benefits associated with the
pre-moistened wipes of the present invention is that high load
factors can be used without significantly compromising filming
and/or streaking results, in part, because the substrate does not
contribute to filming and streaking issues. Those skilled in the
art will recognize that the exact amount of aqueous composition
applied to the substrate will depend on the basis weight of the
substrate and on the end use of the product. In one preferred
embodiment, a relatively low basis weight substrate, from about 20
gm.sup.-2 to about 80 gm.sup.-2 is used in the making of a
pre-moistened wipe suitable for cleaning counters, stove tops,
cabinetry, walls, sinks and the like. For such end uses, the dry
substrate is loaded with an aqueous composition of the invention at
a factor of from about 4 grams to about 10 grams per gram of dry
substrate. In another preferred embodiment, a higher basis
substrate, from about 70 gm.sup.-2 to about 200 gm.sup.-2 is used
in the making of the pre-moistened wipe suitable for cleaning
larger area surfaces, including floors, walls and the like. In such
instances, the wipe is preferably sold with, or designed to work
with, a hand held implement comprising a handle and designed for
wiping and cleaning. Examples of such implements are commercially
available under the trade names Swiffer.RTM., Grab-Its.RTM. and
Vileda.RTM.. For such end uses, the dry substrate is loaded with an
aqueous composition of the invention at a factor of from about 4
grams to about 10 grams per gram of dry substrate.
[0049] Suitable substrates are commercially available under the
trade names DuPont 8838.RTM., Kimberly Clark Hydroknit.RTM. or
Fibrella 3160.RTM. (Suominen). These substrates use a combination
of homogeneously distributed synthetic and natural fibers and use
the preferred hydroentangling process. Substrates manufactured by
alternative processes can also be used, provided they are first
made to be substantially free of binders, latexes and fiber
finishes.
[0050] Aqueous Composition
[0051] The composition of the present invention is formulated as a
liquid composition. A preferred composition herein is an aqueous
composition and therefore, preferably comprises water more
preferably in an amount of from about 60% to about 99%, even more
preferably of from about 70% to about 98% and most preferably about
80% to about 97% by weight of the total composition.
[0052] The aqueous compositions of the present invention have a pH
of about 7 or less and at least one surfactant so as to lower the
contact angle between the compositions and relevant hard surfaces,
thereby assisting the wetting of such surfaces. The compositions
also include a polymeric biguanide compound, which in the presence
of the surfactant, acts as a hydrophilic wetting agent and
preferably as an antimicrobial compound. In a preferred embodiment,
the surfactant is a low residue surfactant, as further described
herein. In another highly preferred embodiment, the aqueous
compositions also comprise at least one water-soluble solvent with
a vapour pressure of greater than about 0.05 mm Hg at 1 atmosphere
pressure (about 6.66 Pa).
[0053] The solids content of the aqueous compositions of the
present invention is generally low, preferably from about 0.01% to
about 4%, more preferably from about 0.05% to about 3%, most
preferably from about 0.10% to about 2.0%. Those skilled in the art
will recognize that the aqueous compositions of the present
invention can be made in the form of about 5.times., about
10.times., or even higher concentrates as desired, and then diluted
prior use. The making of concentrated solutions is particularly
beneficial if the aqueous composition must be transported.
[0054] Composition pH
[0055] The aqueous compositions have a pH of about 7 or less. It is
found that the filming and streaking benefits are not observed, or
are substantially attenuated, at a pH higher than about 7. The pH
measurement is performed by pre-loading the aqueous composition
onto the substrate, allowing the substrate and lotion to
equilibrate at ambient conditions for at least 48 hours, more
preferably at least 72 hours, expressing out the aqueous
composition from the substrate and then running the pH measurement
on the freed up aqueous solution. The Applicant has found that a pH
of about 7 or less is an essential component needed to achieve good
filming/streaking benefits in the presence of the polymeric
biguanide compound. The pH range of the compositions measured by
squeezing out aqueous solution from the pre-moistened wipes, is
preferably from about 0.5 to about 6.5, more preferably from pH
about 1.0 to about 6, more preferably from pH about 2 to about 5.5,
and most preferably from pH about 2.5 to about 5.
[0056] In one preferred embodiment, the aqueous composition has a
pH of from pH about 5 to about pH 7 and does not include an
acidifying agent. In this embodiment the benefits of the invention
are most noteworthy when the substrate comprises at least about 50%
synthetic content and the aqueous composition comprises at least
one surfactant selected from the group consisting of C8-16 poly
alkyl glycosides.
[0057] Acidifying Agent
[0058] In the preferred embodiment wherein the aqueous composition
herein comprises at least one acidifying agent, the pH range of the
compositions measured by squeezing out aqueous solution from the
pre-moistened wipes, is preferably from about 0.5 to about 7, more
preferably from pH about 1.0 to about 6, more preferably from pH
about 2 to about 5.5, and most preferably from pH about 2.5 to
about 5. A suitable acid for use herein is an organic and/or an
inorganic acid, most preferably an organic acid. Suitable organic
acids are monomeric, oligomeric or polymeric organic acids.
[0059] Examples of a suitable organic acids include acetic acid,
glycolic acid, lactic acid, succinic acid, adipic acid, malic acid,
tartaric acid, lactic acid, polyacrylic acid, poly-aspartic acid,
and the like. Highly preferred organic acids are selected from the
group consisting of succinic acid, glutaric acid, adipic acid,
lactic acid, tartaric acid and citric acid. For cost, availability,
buffering capacity and regulatory reasons, citric acid (food grade
desired but not required) is most preferred.
[0060] A typical level of organic acid, preferably comprising at
least one hydroxyl moiety, is from about 0.05% to about 3.0%,
preferably from about 0.05% to about 2.0% and more preferably from
about 0.1% to about 1.5% by weight of the total aqueous
composition. The specific level of acid will depend on the
magnitude and type of the benefits sought. Higher levels promote
improved cleaning of acid-sensitive soils while lower levels
provide better filming streaking. The most preferred levels have
been found to provide a combination of adequate buffering capacity,
excellent cleaning and good filming/streaking properties. As such,
organic acids selected from the group consisting of citric acid,
tartaric acid and lactic acid are highly preferred.
[0061] In a preferred embodiment, the pre-moistened wipes are to be
applied on hard surfaces soiled with hard watermarks, limescale
and/or soap scum, and the like. Such soils are frequently
encountered on bathroom surfaces. Accordingly, the compositions
herein may further comprise acid or base buffers to adjust pH as
appropriate.
[0062] The Surfactant:
[0063] The compositions of the present invention comprise at least
one surfactant, which preferably can be non-ionic, anionic,
cationic, zwitterionic or amphoteric, and mixtures thereof. The
required surfactant is defined as any material with a hydrophobic
component consisting of a hydrocarbon moiety with between about 6
carbon atoms about 20 carbon atoms, and a hydrophilic head group.
The purpose of the surfactant is improved wetting of the hard
surfaces to be treated. The wetting properties of the surfactant
are essential to the compositions of the invention. Thus,
compositions lacking the requisite surfactant are not found to
properly wet the surfaces, leading to the undesirable aggregation
of polymeric biguanide on tile.
[0064] The hydrophobic tail of the surfactant can be linear or
branched, aliphatic aromatic. The hydrophilic head group can
consist of any group such that provides wetting properties. Said
surfactant may be present in the compositions according to the
present invention in amounts of from about 0.01% to about 1.5%,
preferably of from about 0.01% to about 1.0%, and more preferably
of from about 0.01% to about 0.5% by weight of the total
composition.
[0065] More specifically, groups of non-ionic surfactants that can
be used in the context of the following invention are as
follows:
[0066] (i) The polyethylene oxide condensates of alkyl phenols,
e.g., the condensation products of alkyl phenols having an alkyl
group containing from about 6 to about 12 carbon atoms in either a
straight chain or branched chain configuration, with ethylene
oxide, the said ethylene oxide being present in amounts equal to
about 10 to about 25 moles of ethylene oxide per mole of alkyl
phenol. The alkyl substituent in such compounds may be derived from
polymerized propylene, diisobutylene, octane, and nonane.
[0067] (ii) Those derived from the condensation of ethylene oxide
with the product resulting from the reaction of propylene oxide and
ethylene diamine products, which may be varied, in composition
depending upon the balance between the hydrophobic and hydrophilic
elements, which is desired. Examples are to increase the
water-solubility of the molecule as a whole and the liquid
character of the products is retained up to the point where
polyoxyethylene content is about 50% of the total weight of the
condensation product; compounds containing from about 40% to about
80% polyoxyethylene by weight and having a molecular weight of from
about 5000 to about 11000 resulting from the reaction of ethylene
oxide groups with a hydrophobic base constituted of the reaction
product of ethylene diamine and excess propylene oxide, said base
having a molecular weight of the order of about 2500 to about
3000.
[0068] (iii) The condensation product of aliphatic alcohols having
from about 6 to about 18 carbon atoms, in either straight chain or
branched chain configuration, with ethylene oxide, propylene oxide,
butylene oxide, and mixtures thereof, e.g., a coconut alcohol
ethylene oxide condensate having from about 3 to about 15 moles of
ethylene oxide per mole of coconut alcohol, the coconut alcohol
fraction having from about 10 to about 14 carbon atoms; such
materials are commonly known as `alkyl alkoxylates` or `alcohol
alkoxylates`. In some cases, an alkyl ethoxylates can have capping
groups, meaning that they have the structure R1-(EO).sub.xR2, where
R1 is a C6-C18 linear or branched moiety, x is from about 1 to
about 15 and R2, the capping group, is a C1-C8 hydrocarbyl
moiety.
[0069] (iv) Trialkyl amine oxides and trialkyl phosphine oxides
wherein one alkyl group ranges from about 10 to about 18 carbon
atoms and two alkyl groups range from about 1 to about 3 carbon
atoms; the alkyl groups can contain hydroxy substituents; specific
examples are dodecyl di(2-hydroxyethyl)amine oxide and tetradecyl
dimethyl phosphine oxide.
[0070] Although not preferred, the condensation products of
ethylene oxide with a hydrophobic base formed by the condensation
of propylene oxide with propylene glycol are also suitable for use
herein. The hydrophobic portion of these compounds will preferably
have a molecular weight of from about 1500 to about 1800 and will
exhibit water insolubility. The addition of polyoxyethylene
moieties to this hydrophobic portion tends to increase the water
solubility of the molecule as a whole, and the liquid character of
the product is retained up to the point where the polyoxyethylene
content is about 50% of the total weight of the condensation
product, which corresponds to condensation with up to about 40
moles of ethylene oxide. Examples of compounds of this type include
certain of the commercially available Pluronic.RTM. surfactants,
marketed by BASF. Chemically, such surfactants have the structure
(EO).sub.x(PO).sub.y(EO).sub.z or (PO).sub.x(EO).sub.y(PO).sub.z
wherein x, y and z are from about 1 to about 100, preferably about
3 to about 50. Pluronic.RTM. surfactants known to be good wetting
surfactants are more preferred. A description of the Pluronic.RTM.
surfactants, and properties thereof, including wetting properties,
can be found in the brochure entitled BASF Performance Chemicals
Plutonic.RTM. & Tetronic.RTM. Surfactants", available from BASF
and incorporated herein by reference.
[0071] Also not preferred, although suitable as non-ionic
surfactants herein are the condensation products of ethylene oxide
with the product resulting from the reaction of propylene oxide and
ethylenediamine. The hydrophobic moiety of these products consists
of the reaction product of ethylenediamine and excess propylene
oxide, and generally has a molecular weight of from about 2,500 to
about 3,000. This hydrophobic moiety is condensed with ethylene
oxide to the extent that the condensation product contains from
about 40% to about 80% by weight of polyoxyethylene and has a
molecular weight of from about 5,000 to about 11,000. Examples of
this type of non-ionic surfactant include certain of the
commercially available Tetronic.RTM. compounds, marketed by
BASF.
[0072] Other non-ionic surfactants, though not preferred, for use
herein include polyhydroxy fatty acid amides of the structural
formula: 1
[0073] wherein: R.sup.1 is H, C1-C4 hydrocarbyl, 2-hydroxy ethyl,
2-hydroxypropyl, or a mixture thereof, preferably C.sub.1-C.sub.4
alkyl, more preferably C1 or C2 alkyl, most preferably C1 alkyl
(i.e., methyl); and R.sup.2 is a C5-C31 hydrocarbyl, preferably
straight chain C7-C19 alkyl or alkenyl, more preferably straight
chain C9-C17 alkyl or alkenyl, most preferably straight chain
C11-C17 alkyl or alkenyl, or mixtures thereof; and Z is a
polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at
least about 3 hydroxyls directly connected to the chain, or an
alkoxylated derivative (preferably ethoxylated or propoxylated)
thereof. Z preferably will be derived from a reducing sugar in a
reductive amination reaction; more preferably Z is a glycityl.
Suitable reducing sugars include glucose, fructose, maltose,
lactose, galactose, mannose, and xylose. As raw materials, high
dextrose corn syrup can be utilised as well as the individual
sugars listed above. These corn syrups may yield a mix of sugar
components for Z. It should be understood that it is by no means
intended to exclude other suitable raw materials. Z preferably will
be selected from the group consisting of
--CH.sub.2--(CHOH).sub.n--CH.sub.2OH,
--CH(CH.sub.2OH)--(CHOH).sub.n-1--C- H.sub.2OH,
--CH.sub.2--(CHOH).sub.2(CHOR')(CHOH)--CH.sub.2OH, where n is an
integer from about 3 to about 5, inclusive, and R' is H or a cyclic
or aliphatic monosaccharide, and alkoxylated derivatives thereof.
Most preferred are glycityls wherein n is 4, particularly
--CH.sub.2--(CHOH).sub.4--CH.sub.2--OH.
[0074] In Formula (I), R.sup.1 can be, for example, N-methyl,
N-ethyl, N-propyl, N-isopropyl, N-butyl, N-2-hydroxy ethyl, or
N-2-hydroxy propyl. R.sup.2--CO--N< can be, for example,
cocamide, stearamide, oleamide, lauramide, myristamide,
capricamide, palmitamide, tallowamide, etc. Z can be
1-deoxyglucityl, 2-deoxyfructityl, 1-deoxymaltityl,
1-deoxylactityl, 1-deoxygalactityl, 1-deoxymannityl,
1-deoxymaltotriotityl, etc.
[0075] Another type of suitable non-ionic surfactants for use
herein are the 2-alkyl alkanols having an alkyl chain comprising
from about 6 to about 16, preferably from about 7 to about 13, more
preferably from about 8 to about 12, most preferably from about 8
to about 10 carbon atoms and a terminal hydroxy group, said alkyl
chain being substituted in the .alpha. position (i.e., position
number 2) by an alkyl chain comprising from about 1 to about 10,
preferably from about 2 to about 8 and more preferably about 4 to
about 6 carbon atoms.
[0076] Such suitable compounds are commercially available, for
instance, as the Isofol.RTM. series such as Isofol.RTM. 12 (2-butyl
octanol) or Isofol.RTM. 16 (2-hexyl decanol) commercially available
from Condea.
[0077] Another type of suitable non-ionic surfactants for use
herein are the 2-alkyl alkanols having an alkyl chain comprising
from about 6 to about 16, preferably from about 7 to about 13, more
preferably from about 8 to about 12, most preferably from about 8
to about 10 carbon atoms and a terminal hydroxy group, said alkyl
chain being substituted in the .alpha. position (i.e., position
number 2) by an alkyl chain comprising from about 1 to about 10,
preferably from about 2 to about 8 and more preferably about 4 to
about 6 carbon atoms.
[0078] Such suitable compounds are commercially available, for
instance, as the Isofol.RTM. series such as Isofol.RTM. 12 (2-butyl
octanol) or Isofol.RTM. 16 (2-hexyl decanol) commercially available
from Condea.
[0079] A detailed listing of suitable non-ionic surfactants useful
in this invention can be found in U.S. Pat. No. 4,557,853, Collins,
issued Dec. 10, 1985 and incorporated herein by reference.
[0080] Among non-low residue non-ionic surfactants, those formed by
the reaction of an alcohol with one or more ethylene oxides, are
most preferred. These surfactants are prone to form highly visible
films in the absence of polymeric biguanides. However, the
Applicant has found that addition of low to moderate levels (e.g.,
0.05%-0.30%) of the biguanides of the invention to compositions
results in significant toning of the visible film, and leads to
enhanced gloss on tile that is aesthetically pleasing. In effect,
the polymeric biguanides of the invention are effective and
efficient in removing alkyl ethoxylate-produced visible films from
tiles. Non-limiting examples of groups of these preferred non-low
residue alkyl alkoxylates include Neodol.RTM. surfactants (Shell),
Tergitol.RTM. surfactants (Union Carbide) and Icconol.RTM.
surfactants (BASF). One specific example is Neodol 91-6.RTM., an
alkyl ethoxylate comprising from 9 to 11 carbon atoms and an
average of 6 moles of ethoxylation, made by Shell.
[0081] Anionic surfactants are not preferred in the present
invention, particularly as primary surfactants, but can also be
used. Suitable anionic surfactants for use herein include alkali
metal (e.g., sodium or potassium) fatty acids, or soaps thereof,
containing from about 8 to about 24, preferably from about 10 to
about 20 carbon atoms, linear of branched C6-C16 alcohols, C6-C12
alkyl sulfonates, C6-C18 alkyl sulfates 2-ethyl-hexyl
sulfosuccinate, C6-C16 alkyl carboxylates, C6-C18 alkyl ethoxy
sulfates.
[0082] The fatty acids including those used in making the soaps can
be obtained from natural sources such as, for instance, plant or
animal-derived glycerides (e.g., palm oil, coconut oil, babassu
oil, soybean oil, castor oil, tallow, whale oil, fish oil, tallow,
grease, lard and mixtures thereof). The fatty acids can also be
synthetically prepared (e.g., by oxidation of petroleum stocks or
by the Fischer-Tropsch process). Alkali metal soaps can be made by
direct soapification of fats and oils or by the neutralization of
the free fatty acids which are prepared in a separate manufacturing
process. Particularly useful are the sodium and potassium salts of
the mixtures of fatty acids derived from coconut oil and tallow,
i.e., sodium and potassium tallow and coconut soaps.
[0083] Other suitable anionic surfactants for use herein include
water-soluble salts, particularly the alkali metal salts, of
organic sulphuric reaction products having in the molecular
structure an alkyl radical containing from about 8 to about 22
carbon atoms and a radical selected from the group consisting of
sulfonic acid and sulphuric acid ester radicals. Important examples
of these synthetic detergents are the sodium, ammonium or potassium
alkyl sulfates, especially those obtained by sulphating the higher
alcohols produced by reducing the glycerides of tallow or coconut
oil; sodium or potassium alkyl benzene sulfonates, in which the
alkyl group contains from about 9 to about 15 carbon atoms,
especially those of the types described in U.S. Pat. Nos. 2,220,099
and 2,477,383, incorporated herein by reference; sodium alkyl
glyceryl ether sulfonates, especially those ethers of the higher
alcohols derived from tallow and coconut oil; sodium coconut oil
fatty acid monoglyceride sulfates and sulfonates; sodium or
potassium salts of sulfuric acid esters of the reaction product of
one mole of a higher fatty alcohol (e.g., tallow or coconut oil
alcohols) and about three moles of ethylene oxide; sodium or
potassium salts of alkyl phenol ethylene oxide ether sulfates with
about four units of ethylene oxide per molecule and in which the
alkyl radicals contain about 9 carbon atoms; sodium or potassium
salts of alkyl ethylene oxide ether sulfates with about four units
of ethylene oxide per molecule and in which the alkyl radicals
contain 6 to 18 carbon atoms; the reaction product of fatty acids
esterified with isothionic acid and neutralized with sodium
hydroxide where, for example, the fatty acids are derived from
coconut oil; sodium or potassium salts of fatty acid amide of a
methyl taurine in which the fatty acids, for example, are derived
from coconut oil; and others known in the art, a number being
specifically set forth in U.S. Pat. Nos. 2,486,921, 2,486,922 and
2,396,278, incorporated herein by reference. Other suitable anionic
surfactants include C6-C18 alkyl ethoxy carboxylates, C8-C18 methyl
ester sulfonates, 2-ethyl-1-hexyl sulfosuccinamate, 2-ethyl-1-hexyl
sulfosuccinate and the like.
[0084] Cationic surfactants are not preferred but can be used at
low levels in compositions of the present invention are those
having a long-chain hydrocarbyl group. Examples of such cationic
surfactants include the ammonium surfactants such as
alkyldimethylammonium halogenides, and those surfactants having the
formula:
[R.sup.2(OR.sup.3).sub.y][R.sup.4(OR.sup.3).sub.y].sub.2R.sup.5N.sup.+X.su-
p.-
[0085] wherein R.sup.2 is an alkyl or alkyl benzyl group having
from about 8 to about 18 carbon atoms in the alkyl chain, each
R.sup.3 is selected from the group consisting of
--CH.sub.2CH.sub.2--, --CH.sub.2CH(CH.sub.3)--,
--CH.sub.2CH(CH.sub.2OH)--, --CH.sub.2CH.sub.2CH.sub.2--, and
mixtures thereof; each R.sup.4 is selected from the group
consisting of C.sub.1-C.sub.4 alkyl, C.sub.1-C.sub.4 hydroxyalkyl,
benzyl ring structures formed by joining the two R.sup.4 groups,
--CH.sub.2CHOH--CHOHCOR.sup.6CHOHCH.sub.2OH wherein R.sup.6 is any
hexose or hexose polymer having a molecular weight less than about
1000, and hydrogen when y is not 0; R.sup.5 is the same as R.sup.4
or is an alkyl chain wherein the total number of carbon atoms of
R.sup.2 plus R.sup.5 is not more than about 18; each y is from 0 to
about 10 and the sum of the y values is from 0 to about 15; and X
is any compatible anion.
[0086] Other cationic surfactants useful herein are also described
in U.S. Pat. No. 4,228,044, Cambre, issued Oct. 14, 1980,
incorporated herein by reference.
[0087] Zwitterionic surfactants, as defined herein, are
surface-active agents that comprise at least one cationic group and
at least one anionic group on the same molecule. This class of
surfactants is described in greater detail in the section entitled
low residue surfactants. Amphoteric surfactants, as defined herein,
are surface-active agents similar to zwitterionic surfactants. They
differ in that the do not include a cationic group, but rather an
amine group that becomes cationic, i.e., protonated, at low pH
(below 5.5). Amphoteric surfactants are also described in greater
detail in the section entitled low residue surfactants. A good
commercial source of all the surfactants described above can be
found in McCutcheon's EMULSIFIERS AND DETERGENTS, North American
Edition and International editions, 2001, McCutcheon Division, MC
Publishing Company, also incorporated herein by reference.
[0088] Low-residue Surfactant:
[0089] In a particularly preferred embodiment, the composition
applied to the pre-moistened wipes according to the present
invention comprises a low-residue surfactant or a mixture thereof.
By "low-residue surfactant" it is meant herein any surfactant that
mitigates the appearance of either streaks or films upon
evaporation of the aqueous compositions comprising said surfactant.
A low residue surfactant-containing composition may be identified
using either gloss-meter readings or expert visual grade readings,
and running tests on compositions not comprising the essential
polymeric biguanide. The conditions for the determination of what
constitutes a low-residue surfactant are one of the following: (a)
less than about 1.5% gloss loss on black shiny porcelain tiles,
preferably on black Extracompa.RTM. shiny porcelain tiles used in
this invention; or (b) lack of significant filming and/streaking as
judged by one skilled in the art. One of the important advantages
of the low-residue surfactant is that it requires less polymeric
biguanide compound for gloss enhancement, relative to non-low
residue surfactants. This can be important in light of cost
considerations, potential stickiness issues delivered by higher
concentrations of the polymeric biguanide, and/or concerns over the
ability to completely strip a more concentrated polymeric biguanide
film.
[0090] Whilst not wishing to be limited by theory, it is believed
that low residue surfactants exhibit a reduced tendency for
inter-molecular aggregation. With less aggregation of surfactant
molecules to form visible macromolecular complexes following
evaporation of water from the aqueous compositions, the remaining
residue is less visible, resulting in fewer streaks. Unlike
conventional non-ionic surfactants such as alkyl ethoxylates and
alkyl phenol ethoxylates, which exhibit rich phase chemistry, the
"low residue" surfactants do not easily form anisotropic
macromolecular structures in water, which helps make the film which
they form upon dry-down from solution less visible. Indeed, the
residue is observed to be nearly colorless, leading to films that
are essentially not visible to the naked eye or in some instances,
films that enhance the gloss of the treated tiles.
[0091] As identified within this invention there are three classes
of low residue surfactants: selected non-ionic surfactants,
zwitterionic surfactants and amphoteric surfactants.
[0092] One class of low residue surfactants is the group of
non-ionic surfactants that include a head group consisting of one
or more sugar moieties. Examples include alkyl polyglycosides,
especially poly alkyl glucosides, and sucrose esters. The chain
length of alkyl polyglycoside surfactants is preferably about C6 to
about C18, more preferably from about C8 to about C16. The chain
length of the preferred sucrose esters is C16-C22. The hydrophilic
component of these surfactants may comprise one or more sugar
moieties liked by glycosidic linkages. In a preferred embodiment,
the average number of sugar moieties per surfactant chain length is
from about 1 to about 3, more preferably from about 1.1 to about
2.2.
[0093] The most preferred non-ionic low residue surfactants are the
alkylpolysaccharides that are disclosed in U.S. patents: U.S. Pat.
No. 5,776,872, Cleansing compositions, issued Jul. 7, 1998, to
Giret, Michel Joseph; Langlois, Anne; and Duke, Roland Philip; U.S.
Pat. No 5,883,059, Three in one ultra mild lathering antibacterial
liquid personal cleansing composition, issued Mar. 16, 1999, to
Furman, Christopher Allen; Giret, Michel Joseph; and Dunbar, James
Charles; etc.; U.S. Pat. No. 5,883,062, Manual dishwashing
compositions, issued Mar. 16, 1999, to Addison, Michael Crombie;
Foley, Peter Robert; and Allsebrook, Andrew Micheal; and U.S. Pat.
No. 5,906,973, issued May 25, 1999, Process for cleaning vertical
or inclined hard surfaces, by Ouzounis, Dimitrios and Nierhaus,
Wolfgang.
[0094] Suitable alkyl polyglucosides for use herein are disclosed
in U.S. Pat. No. 4,565,647, Llenado, issued Jan. 21, 1986, having a
hydrophobic group containing from about 6 to about 30 carbon atoms,
preferably from about 10 to about 16 carbon atoms and
polysaccharide, e.g., a polyglycoside, hydrophilic group containing
from about 1.3 to about 10, preferably from about 1.3 to about 3,
most preferably from about 1.3 to about 2.7 saccharide units. Any
reducing saccharide containing 5 or 6 carbon atoms can be used,
e.g., glucose, galactose, and galactosyl moieties can be
substituted for the glucosyl moieties. (Optionally the hydrophobic
group is attached at the 2-, 3-, 4-, etc. positions thus giving a
glucose or galactose as opposed to a glucoside or galactoside.).
The intersaccharide bonds can be, e.g., between the one position of
the additional saccharide units and the 2-, 3-, 4-, and/or
6-positions of the preceding saccharide units. The glycosyl is
preferably derived from glucose.
[0095] Optionally, there can be a polyalkyleneoxide chain joining
the hydrophobic moiety and the polysaccharide moiety. The preferred
alkyleneoxide is ethylene oxide. Typical hydrophobic groups include
alkyl groups, either saturated or unsaturated, branched or
unbranched containing from about 8 to about 18, preferably from
about 10 to about 16, carbon atoms. Preferably, the alkyl group can
contain up to about 3 hydroxy groups and/or the polyalkyleneoxide
chain can contain up to about 10, preferably less than 5,
alkyleneoxide moieties. Suitable alkyl polysaccharides are octyl,
nonyldecyl, undecyldodecyl, tridecyl, tetradecyl, pentadecyl,
hexadecyl, heptadecyl, and octadecyl, di-, tri-, tetra-, penta-,
and hexaglucosides, galactosides, lactosides, glucoses,
fructosides, fructoses and/or galactoses. Suitable mixtures include
coconut alkyl, di-, tri-, tetra-, and pentaglucosides and tallow
alkyl tetra-, penta-, and hexaglucosides.
[0096] The preferred alkylpolyglycosides have the formula:
R.sup.2O(C.sub.nH.sub.2nO).sub.t(glucosyl).sub.x
[0097] wherein R.sup.2 is selected from the group consisting of
alkyl, alkylphenyl, hydroxyalkyl, hydroxyalkylphenyl, and mixtures
thereof in which the alkyl groups contain from about 10 to about
18, preferably from about 12 to about 14, carbon atoms; n is 2 or
3, preferably 2; t is from 0 to about 10, preferably 0; and x is
from about 1.3 to about 10, preferably from about 1.3 to about 3,
most preferably from about 1.3 to about 2.7. The glycosyl is
preferably derived from glucose. To prepare these compounds, the
alcohol or alkylpolyethoxy alcohol is formed first and then reacted
with glucose, or a source of glucose, to form the glucoside
(attachment at the 1-position). The additional glycosyl units can
then be attached between their 1-position and the preceding
glycosyl units 2-, 3-, 4- and/or 6-position, preferably
predominantely the 2-position.
[0098] Zwitterionic surfactants represent a second class of highly
preferred low-residue surfactants. Zwitterionic surfactants contain
both cationic and anionic groups on the same molecule over a wide
pH range. The typical cationic group is a quaternary ammonium
group, although other positively charged groups like sulfonium and
phosphonium groups can also be used. The typical anionic groups are
carboxylates and sulfonates, preferably sulfonates, although other
groups like sulfates, phosphates and the like, can be used. Some
common examples of these detergents are described in the patent
literature: U.S. Pat. Nos. 2,082,275, 2,702,279 and 2,255,082,
incorporated herein by reference.
[0099] A generic formula for some preferred zwitterionic
surfactants is:
R--N.sup.+(R.sup.2)(R.sup.3)(R.sup.4)X.sup.-,
[0100] wherein R is a hydrophobic group,; R.sup.2 and R.sup.3 are
each a C1-4 alkyl hydroxy alkyl or other substituted alkyl group
which can be joined to form ring structures with the N; R.sup.4 is
a moiety joining the cationic nitrogen to the hydrophilic anionic
group, and is typically an alkylene, hydroxy alkylene, or
polyalkoxyalkylene containing from about one to about four carbon
atoms; and X is the hydrophilic group, most preferably a sulfonate
group.
[0101] Preferred hydrophobic groups R are alkyl groups containing
from about 6 to about 20 carbon atoms, preferably less than about
18 carbon atoms. The hydrophobic moieties can optionally contain
sites of instauration and/or substituents and/or linking groups
such as aryl groups, amido groups, ester groups, etc. In general,
the simple alkyl groups are preferred for cost and stability
reasons. A specific example of a "simple" zwitterionic surfactant
is 3-(N-dodecyl-N,N-dimethyl)-2-hyd- roxypropane-1-sulfonate
available from the Degussa-Goldschmidt Company under the tradename
Varion HC.RTM..
[0102] Other specific zwitterionic surfactants have the generic
formula:
R--C(O)--N(R.sup.2)--(CR.sup.3.sub.2).sub.n--N(R.sup.2).sub.2.sup.+--(CR.s-
up.3.sub.2).sub.n--SO.sub.3.sup.-,
[0103] wherein each R is a hydrocarbon, e.g., an alkyl group
containing from about 6 to about 20, preferably up to about 18,
more preferably up to about 16 carbon atoms, each (R.sup.2) is
either a hydrogen (when attached to the amido nitrogen), short
chain alkyl or substituted alkyl containing from about 1 to about 4
carbon atoms, preferably groups selected from the group consisting
of methyl, ethyl, propyl, hydroxy substituted ethyl and propyl and
mixtures thereof, more preferably methyl, each (R.sup.3) is
selected from the group consisting of hydrogen and hydroxyl groups,
and each n is a number from about 1 to about 4, more preferably
about 2 or about 3, most preferably about 3, with no more than
about 1 hydroxy group in any (CR.sup.3.sub.2) moiety. The R group
can be linear or branched, saturated or unsaturated. The R.sup.2
groups can also be connected to form ring structures. A highly
preferred low residue surfactant of this type is a C12-14
acylamidopropylene (hydroxypropylene)_sulfobetaine that is
available from Degussa-Goldschmidt under the tradename Rewoteric AM
CAS-15U.RTM..
[0104] Compositions of this invention containing the above
hydrocarbyl amido sulfobetaine can contain more perfume and/or
hydrophobic perfumes than similar compositions containing
conventional anionic surfactants. This can be desirable in the
preparation of consumer products.
[0105] Other very useful zwitterionic surfactants include
hydrocarbyl, e.g., fatty alkylene betaines. These surfactants tend
to become more cationic as pH is lowered due to protonation of the
carboxyl anionic group, and in one embodiment have the generic
formula:
R--N(R.sup.1).sub.2.sup.+--(CR.sup.2.sub.2).sub.n--COO.sup.-,
[0106] wherein R is a hydrocarbon, e.g., an alkyl group containing
from about 6 to about 20, preferably up to about 18, more
preferably up to about 16 carbon atoms, each (R.sup.1) is a short
chain alkyl or substituted alkyl containing from about 1 to about 4
carbon atoms, preferably groups selected from the group consisting
of methyl, ethyl, propyl, hydroxy substituted ethyl and propyl and
mixtures thereof, more preferably methyl, (R.sup.2) is selected
from the group consisting of hydrogen and hydroxyl groups, and n is
a number from about 1 to about 4, preferably about 1. A highly
preferred low residue surfactant of this type is Empigen BB.RTM., a
coco dimethyl betaine produced by Albright & Wilson.
[0107] In another equally preferred embodiment, these betaine
surfactants have the generic formula:
R--C(O)--N(R.sup.2)--(CR.sup.3.sub.2).sub.n--N(R.sup.2).sub.2.sup.+--(CR.s-
up.3.sub.2).sub.n--COO.sup.-,
[0108] wherein each R is a hydrocarbon, e.g., an alkyl group
containing from about 6 to about 20, preferably up to about 18,
more preferably up to about 16 carbon atoms, each (R.sup.2) is
either a hydrogen (when attached to the amido nitrogen), short
chain alkyl or substituted alkyl containing from 1 to 4 carbon
atoms, preferably groups selected from the group consisting of
methyl, ethyl, propyl, hydroxy substituted ethyl and propyl and
mixtures thereof, more preferably methyl, each (R.sup.3) is
selected from the group consisting of hydrogen and hydroxyl groups,
and each n is a number from about 1 to about 4, more preferably
about 2 or about 3, most preferably about 3, with no more than
about 1 hydroxy group in any (CR.sup.3.sub.2) moiety. The R group
can be linear or branched, saturated or unsaturated. The R.sup.2
groups can also be connected to form ring structures. A highly
preferred low residue surfactant of this type is TEGO Betain
F.RTM., a coco amido propyl betaine produced by
Degussa-Goldschmidt.
[0109] The third class of preferred low residue surfactants
comprises the group consisting of amphoteric surfactants. These
surfactants function essentially as zwitterionic surfactants at
acidic pH. One suitable amphoteric surfactant is a C8-C16 amido
alkylene glycinate surfactant (`ampho glycinate`). Another suitable
amphoteric surfactant is a C8-C16 amido alkylene propionate
surfactant (`ampho propionate`). These surfactants are essentially
cationic at acidic pH and preferably have the generic
structure:
R--C(O)--(CH.sub.2).sub.n--N(R.sup.1)--(CH.sub.2).sub.x--COOH,
[0110] wherein R--C(O)-- is a C5-C15, pre hydrophobic fatty acyl
moiety, each n is from about 1 to about 3, each R1 is preferably
hydrogen or a C1-C2 alkyl or hydroxyalkyl group, and x is about 1
or about 2. Such surfactants are available, in the salt form, from
Degussa-Goldschmidt chemicals under the tradename Rewoteric
AM.RTM.. Examples of other suitable low residue surfactants include
cocoyl amido ethyleneamine-N-(methyl) acetates, cocoyl amido
ethyleneamine-N-(hydroxye- thyl) acetates, cocoyl amido
propyleneamine-N-(hydroxyethyl) acetates, and analogs and mixtures
thereof.
[0111] Other suitable, amphoteric surfactants being either cationic
or anionic depending upon the pH of the system are represented by
surfactants such as dodecylbeta-alanine, N-alkyltaurines such as
the one prepared by reacting dodecylamine with sodium isethionate
according to the teaching of U.S. Pat. No. 2,658,072, N-higher
alkylaspartic acids such as those produced according to the
teaching of U.S. Pat. No. 2,438,091, and the products sold under
the trade name "Miranol.RTM.", and described in U.S. Pat. No.
2,528,378, said patents being incorporated herein by reference.
[0112] Low-residue surfactants contribute to better
filming/streaking performance (i.e., low or substantially no
visible streaks- and/or film-formation) of the pre-moistened wipes
according to the present invention. Whilst not wishing to be
limited by theory, it is believed that the bulky sugar moieties of
alkyl polyglycosides and sucrose esters function to inhibit the
aggregation of surfactant that occurs upon evaporation of water in
the aqueous solutions of the present invention. It is also believed
that the zwitterionic and amphoteric surfactants show reduced
aggregation relative to conventional surfactants because the
intra-molecular electrostatic attractions between the anionically
and cationically charged groups are stronger than the
intermolecular surfactant-surfactant attractions. This results in a
reduced tendency for molecular assembly that inhibits visible
residue.
[0113] In a preferred embodiment according to the present
invention, the low residue surfactant herein is selected in order
to provide an Extracompa.RTM. black shiny ceramic tile (described
in the experimental section) treated with the pre-moistened wipe
herein with a gloss-meter reading such that at a 95% confidence
level, the composition does not cause a significant loss in gloss
on the tiles, relative to clean untreated tiles, when tested with a
BYK gloss-meter.RTM. using a 60.degree. angle setting. The test is
performed as described the experimental herein below.
[0114] By `not significant loss in gloss`, it is meant herein that
the mean difference in gloss between tiles treated with two
separate wipe treatments using 15 readings for each is not
statistically significant (.alpha.=0.05). Similarly, by
`significant enhancement (or gain) in gloss`, it is meant herein
that the mean difference in gloss between tiles treated with two
separate wipe treatments using 15 readings for each is
statistically significant (.alpha.=0.05). In these
filming/streaking tests, statistical significance is established at
the 95% confidence level (.alpha.=0.05), using a one-tailed test
and pair-wise statistical treatment of the samples. All samples are
assumed to exhibit a normal distribution with equal variances.
Using the raw data, t-tests are calculated and compared to the
critical t statistic. When the calculated t-test exceeds
t-critical, the samples are `significantly` different. When
t-calculated is less than t-critical, the samples are not
`significantly` different. The direction of the significance is
determined by sign of the mean differences (i.e., `either mean
treatment .delta.`, `mean .delta. (PHMB-noPHMB)` or `mean
.delta.(PHMB-Quat)`. For example, if the mean gloss for a treatment
is higher than that of the untreated tile, and t-calculated exceeds
t-critical, then the data suggest that at a 95% confidence level
(.alpha.=0.05) the treatment has a significantly higher gloss than
the untreated tile. The statistics treatment of dependent paired
samples (`mean treatment .delta.`) and independent paired samples
(`mean .delta. PHMB-noPHMB` or `mean .delta.(PHMB-Quat`) can be
found in Anderson, Sweeney and Williams, Statistics for Business
and Economics, 6th edition, West Publishing Company, 1996,
incorporated herein by reference. The statistics can be
conveniently run using the statistical function in Microsoft
Excel.TM.. Excel provides a P-value, which corresponds to the level
of significance of the results. P-values below 0.05 indicate
statistical significance at .alpha.=0.05; P-values above 0.05
indicate no statistical significance at .alpha.=0.05.
[0115] Low residue surfactants represent a particularly preferred
sub-category of surfactants. Accordingly, low-residue surfactants
can be present in the compositions of this invention at levels
previously specified for the surfactants, i.e., from about 0.01% to
about 1.5%, preferably of from about 0.01% to about 1.0%, and more
preferably of from about 0.01% to about 0.5% by weight of the total
composition. Importantly, the Applicant has found that the use of a
low residue surfactant in combination with a conventional
surfactant (i.e., non-low residue) can mitigate filming and/or
streaking issues relative to similar compositions that only use the
conventional surfactant.
[0116] Polymeric Biguanide:
[0117] As an essential ingredient the composition applied to the
pre-moistened wipes according to the present invention comprises a
polymeric biguanide. Any polymeric biguanide known to those skilled
in the art, or mixtures thereof, may be used herein.
[0118] Biguanide agents are characterized in comprising at least
one, preferably about 2 or more, biguanide moieties according to
the following formula:
--NH--C(.dbd.NH)--NH--C(.dbd.NH)--NH--
[0119] In the context of the compositions of this invention, the
polymeric biguanides are oligo- or poly(alkylene biguanides) or
salts thereof or mixtures thereof. More preferred biguanides are
oligo- or poly(hexamethylene biguanides) or salts thereof or
mixtures thereof.
[0120] In a most preferred embodiment according to the present
invention said polymeric biguanide is a poly(hexamethylene
biguanide) or salt thereof according to the following formula:
--[--(CH.sub.2).sub.3--NH--C(.dbd.NH)--NH--C(.dbd.NH)--NH--(CH.sub.2).sub.-
3--].sub.n--
[0121] wherein n is an integer selected from about 1 to about 50,
preferably about 1 to about 20, more preferably about 9 to about
18. More preferably said biguanide is a salt of a
poly(hexamethylene biguanide) according to the following
formula:
--[--(CH.sub.2).sub.3--NH--C(.dbd.NH)--NH--C(.dbd.NH)--NH--(CH.sub.2).sub.-
3--].sub.n-.nHX
[0122] wherein n is an integer selected from about 1 to about 50,
preferably about 1 to about 20, more preferably about 9 to about
18, and HX is salt component, preferably HCl.
[0123] A most preferred poly(hexamethylene biguanide) hydrochloride
(PHMB) wherein in the above formula n=12, is commercially available
under the trade name Vantocil P.RTM., Vantocil IB.RTM. or Cosmocil
CQ.RTM. from Avecia. Another suitable PHMB wherein n=15, is
commercially sold by Avecia under the tradename Reputex 20.RTM..
The choice of poly(hexamethylene biguanide) hydrochloride, as the
most preferred polymeric biguanide for the compositions of this
invention is driven by its unusually good filming and streaking
properties within the scope of the compositions disclosed herein,
and by its regulatory status as an approved antimicrobial active
for hard surface cleaning applications in the European Union
(Biocidal Products Directive) and in the United States (EPA actives
list).
[0124] The Applicant has found that the micro-effectiveness of PHMB
is optimized at relatively low concentrations of organic acid. For
example, the effectiveness of PHMB as an antimicrobial active in a
composition of the invention comprising 0.25% citric acid is
enhanced relative to a similar composition comprising 1% citric
acid. This is advantageous since lower concentrations of acid tend
to result in improved filming and streaking benefits, all while
promoting good antimicrobial efficiency.
[0125] Typically the composition herein may comprise up to about
2%, preferably from about 0.01% to about 1%, more preferably from
about 0.02% to about 0.75%, even more preferably from about 0.03%
to about 0.5%, by weight of the total composition of a polymeric
biguanide. Those skilled in the art will appreciate that the level
of polymeric biguanide is dependent on the magnitude of the gloss
and optional antimicrobial benefits sought. Additionally, the
polymeric biguanides do not deleteriously impact cleaning, and in
some cases are found to provide improved cleaning versus identical
compositions that do not comprise the polymer. Polymeric biguanides
may also provide `next-time cleaning` benefits, meaning that they
make subsequent cleanings easier.
[0126] For hygiene claims in Europe, and sanitization, and `Limited
Disinfection` benefits in Canada and the United States, lower
levels of polymeric biguanide, up to about 0.20%, are sufficient.
For complete biocidal effectiveness against Gram positive and Gram
negative microorganisms, it is recommended that at least about
0.20%, more preferably about 0.25% most preferably about 0.30%
polymeric biguanide compound be included in the aqueous
composition. Higher levels of biguanide may be needed, up to about
2%, for particularly tough to kill microorganisms such as
Trychophyton or other fungi.
[0127] Optional Components
[0128] Solvents
[0129] As an optional but highly preferred ingredient the
composition applied to the pre-moistened wipes comprises one or
more solvents or mixtures thereof. Solvents can provide improved
filming and/or streaking benefits. Whilst not wishing to be limited
by theory, it is believed that solvents disrupt micelle formation,
thus reducing surfactant aggregation. As such, they act as gloss
toning agents, reducing gloss loss or promoting gloss gain on the
surfaces of the present invention. Solvents are also beneficial
because of their surface tension reduction properties help the
cleaning profile of the compositions disclosed herein. Finally,
solvents, particularly solvents with high vapour pressure,
specifically vapour pressures of about 0.05 mm Hg at 25.degree. C.
and 1 atmosphere pressure (6.66 Pa) or higher, can provide cleaning
and filming and/or streaking benefits without leaving residue.
[0130] Solvents for use herein include all those known in the art
for use in hard-surface cleaner compositions. Suitable solvents can
be selected from the group consisting of: aliphatic alcohols,
ethers and di-ethers having from about 4 to about 14 carbon atoms,
preferably from about 6 to about 12 carbon atoms, and more
preferably from about 8 to about 10 carbon atoms; glycols or
alkoxylated glycols; glycol ethers; alkoxylated aromatic alcohols;
aromatic alcohols; terpenes; and mixtures thereof. Aliphatic
alcohols and glycol ether solvents are most preferred, particularly
those with vapour pressure of about 0.05 mm Hg at 25.degree. C. and
1 atmosphere pressure (6.66 Pa).
[0131] Aliphatic alcohols, of the formula R--OH wherein R is a
linear or branched, saturated or unsaturated alkyl group of from
about 1 to about 20 carbon atoms, preferably from about 2 to about
15 and more preferably from about 5 to about 12, are suitable
solvents. Suitable aliphatic alcohols are methanol, ethanol,
propanol, isopropanol or mixtures thereof. Among aliphatic
alcohols, ethanol and isopropanol are most preferred because of
their high vapour pressure and tendency to leave no residue.
[0132] Suitable glycols to be used herein are according to the
formula HO--CR1R2-OH wherein R1 and R2 are independently H or a
C2-C10 saturated or unsaturated aliphatic hydrocarbon chain and/or
cyclic. Suitable glycols to be used herein are dodecaneglycol
and/or propanediol.
[0133] In one preferred embodiment, at least one glycol ether
solvent is incorporated in the compositions of the present
invention. Particularly preferred glycol ethers have a terminal
C3-C6 hydrocarbon attached to from one to three ethylene glycol or
propylene glycol moieties to provide the appropriate degree of
hydrophobicity and, preferably, surface activity. Examples of
commercially available solvents based on ethylene glycol chemistry
include mono-ethylene glycol n-hexyl ether (Hexyl Cellosolve.RTM.)
available from Dow Chemical. Examples of commercially available
solvents based on propylene glycol chemistry include the di-, and
tri-propylene glycol derivatives of propyl and butyl alcohol, which
are available from Arco under the trade names Arcosolv.RTM. and
Dowanol.RTM..
[0134] In the context of the present invention, preferred solvents
are selected from the group consisting of mono-propylene glycol
mono-propyl ether, di-propylene glycol mono-propyl ether,
mono-propylene glycol mono-butyl ether, di-propylene glycol
mono-propyl ether, di-propylene glycol mono-butyl ether;
tri-propylene glycol mono-butyl ether; ethylene glycol mono-butyl
ether; di-ethylene glycol mono-butyl ether, ethylene glycol
mono-hexyl ether and di-ethylene glycol mono-hexyl ether, and
mixtures thereof. "Butyl" includes normal butyl, isobutyl and
tertiary butyl groups. Mono-propylene glycol and mono-propylene
glycol mono-butyl ether are the most preferred cleaning solvent and
are available under the tradenames Dowanol DPnP.RTM. and Dowanol
DPnB.RTM.. Di-propylene glycol mono-t-butyl ether is commercially
available from Arco Chemical under the tradename Arcosolv
PTB.RTM..
[0135] In a particularly preferred embodiment, the cleaning solvent
is purified so as to minimize impurities. Such impurities include
aldehydes, dimers, trimers, oligomers and other by-products. These
have been found to deleteriously affect product odour, perfume
solubility and end result. The inventors have also found that
common commercial solvents, which contain low levels of aldehydes,
can cause irreversible and irreparable yellowing of certain hard
surfaces. By purifying the cleaning solvents so as to minimize or
eliminate such impurities, surface damage is attenuated or
eliminated.
[0136] Though not preferred, terpenes can be used in the present
invention. Suitable terpenes to be used herein monocyclic terpenes,
dicyclic terpenes and/or acyclic terpenes. Suitable terpenes are:
D-limonene; pinene; pine oil; terpinene; terpene derivatives as
menthol, terpineol, geraniol, thymol; and the citronella or
citronellol types of ingredients.
[0137] Suitable alkoxylated aromatic alcohols to be used herein are
according to the formula R--(A).sub.n--OH wherein R is an alkyl
substituted or non-alkyl substituted aryl group of from about 1 to
about 20 carbon atoms, preferably from about 2 to about 15 and more
preferably from about 2 to about 10, wherein A is an alkoxy group
preferably butoxy, propoxy and/or ethoxy, and n is an integer of
from about 1 to about 5, preferably about 1 to about 2. Suitable
alkoxylated aromatic alcohols are benzoxyethanol and/or
benzoxypropanol.
[0138] Suitable aromatic alcohols to be used herein are according
to the formula R--OH wherein R is an alkyl substituted or non-alkyl
substituted aryl group of from about 1 to about 20 carbon atoms,
preferably from about 1 to about 15 and more preferably from about
1 to about 10. For example a suitable aromatic alcohol to be used
herein is benzyl alcohol.
[0139] When present, solvents are found to be most effective at
levels from about 0.5% to about 25%, more preferably about 1.0% to
about 20% and most preferably, about 2% to about 15%.
[0140] Antifoaming Agent
[0141] The pre-moistened wipes preferably also comprise an
antifoaming agent, preferably in the liquid composition. Any
antifoaming agent known in the art is suitable for the present
invention. Highly preferred antifoaming agents are those comprising
silicone. Other preferred antifoaming agents may further comprise a
fatty acid and/or a capped alkoxylated nonionic surfactant as
defined herein after.
[0142] Preferably the amount of antifoaming agent used expressed in
weight percent active, i.e., silicone (usually poly-dimethyl
siloxane), fatty acid or capped alkoxylated nonionic surfactant, is
from about 0.001% to about 0.5%, more preferably from about 0.005%
to about 0.2%, most preferably from about 0.01% to about 0.1% of
the weight of the aqueous lotion composition as made prior to
impregnation onto the dry substrate.
[0143] Typically, if present, the fatty acid antifoaming agent is
present at a concentration of from about 0.01% to about 0.5%,
preferably from about 0.01% to about 0.5%, and more preferably from
about 0.03% to about 0.2% by weight of the aqueous lotion
composition as made prior to impregnation onto the dry
substrate.
[0144] Typically, when present, the capped alkoxylated nonionic
surfactant antifoaming agent is present at a concentration of from
about 0.01% to about 1%, preferably from about 0.01% to about 0.5%
and more preferably from about 0.03%% to about 0.2% by weight of
the aqueous lotion composition as made prior to impregnation onto
the dry substrate.
[0145] It is understood to those skilled in the art that
combinations of antifoaming agents can also be used to provide the
desired suds profile for a given aqueous composition.
[0146] Suitable capped alkoxylated nonionic surfactants for use
herein are according to the formula:
R1(O--CH2--CH2).sub.n--(OR2).sub.m--O--R3
[0147] wherein R1 is a C8-C24 linear or branched alkyl or alkenyl
group, aryl group, alkaryl group, preferably R.sup.1 is a C8-C18
alkyl or alkenyl group, more preferably a C.sub.10-C.sub.15 alkyl
or alkenyl group, even more preferably a C10-C15 alkyl group;
wherein R2 is a C1-C10 linear or branched alkyl group, preferably a
C2-C10 linear or branched alkyl group, preferably a C3 group;
wherein R3 is a C1-C10 alkyl or alkenyl group, preferably a C1-C5
alkyl group, more preferably methyl; and wherein n and m are
integers independently ranging in the range of from about 1 to
about 20, preferably from about 1 to about 10, more preferably from
about 1 to about 5; or mixtures thereof.
[0148] Suitable silicones for use herein include any silicone and
silica-silicone mixtures. Silicones can be generally represented by
alkylated polysiloxane materials (e.g., poly-dimethyl siloxanes),
while silica is normally used in finely divided forms exemplified
by silica aerogels and xerogels and hydrophobic silicas of various
types. These materials can be incorporated as particulates in which
the silicone is advantageously releasably incorporated in a
water-soluble or water-dispersible, substantially
non-surface-active detergent impermeable carrier. Alternatively,
the silicone can be dissolved or dispersed in a liquid carrier and
applied by spraying on to one or more of the other components.
[0149] One preferred antifoaming agent in accordance with the
present invention is available from Wacker as Wacker silicone
antifoaming emulsion SE 2.RTM.. Other preferred antifoam agents
include Dow Coming AF.RTM. emulsion and Dow Coming DB.RTM.
emulsion.
[0150] Hydrotropes:
[0151] Hydrotropes are advantageously used to ensure solubility of
the aqueous composition compositions, and in particular to ensure
adequate perfume solubility. Hydrotropes include the sulfonates of
toluene, xylene and cumene, sulfates of naphthalene, anthracene,
and higher aromatics, and C3-C10 linear or branched alkyl benzenes,
C6-C8 sulfates such as hexyl sulfate and 2-ethyl-1-hexyl sulfate,
short chain pyrrolidones such as octyl pyrrolidone, and the like.
Other preferred hydrotropes include the oligomers and polymers
comprising polyethylene glycol. In a particularly preferred
embodiment, alkyl ethoxylates comprising at least an average of
about 15 moles of ethylene oxide, more preferably at least about 20
moles of ethylene oxide per mole chain length (alcohol) are
advantageously employed. Unlike conventional hydrotropes, the
preferred alkyl ethoxylate hydrotropes are found to have little or
no impact on the filming and streaking properties of the
compositions of the present invention. When present, hydrotropes
are preferably used at solution weight percent of from about 0.01%
to about 0.5%, more preferably about 0.03% to about 0.25%.
[0152] The liquid compositions according to the present invention
may comprise a variety of other optional ingredients depending on
the technical benefit aimed for and the surface treated. Suitable
optional ingredients for use herein include polymers, buffers,
perfumes, colorants, pigments and/or dyes.
[0153] Filming/Streaking, Cleaning and Antimicrobial
Performance
[0154] The Applicant has found that the interaction of the
substrate as described herein, the composition pH, the
surfactant(s) and the polymeric biguanide-containing composition
results in a pre-moistened wipe showing very low or even no
filming/streaking ("filming/streaking performance benefit") when
used on a hard surface, preferably when used on a shiny hard
surface. The overall filming and streaking profiles of surfaces
treated with the compositions of the invention benefits are
particularly good when the surfactant is a low-residue surfactant.
Without being bound by theory, it is believed that part of the
filming and streaking benefits are partly attributable to the
properties of the substrate. Indeed, it has been found that the
solution-induced leaching of binder and/or latex from the substrate
leads to undesirable deposits on surfaces to be cleaned by the
pre-moistened wipe. This deposition may lead to filming and/or
streaking. The release of binder and/or latex may be due to the
interaction of a composition applied to said substrate and the
binder and/or latex of the substrate. Therefore, the use of a
substantially binder and/or latex material-free substrate will
eliminate the substrate as a source of filming and/or streaking on
hard surfaces. Moreover, the leaching of binder and latex and
associated by-products is enhanced for pre-moistened wipes
comprising aqueous compositions at low pH (e.g., below pH 5) or
compositions containing aggressive or reactive chemical compounds
(such as glycol ether solvents, isopropyl alcohol or raw materials
that can react with the substrate binder).
[0155] So as to reduce the overall level of filming and/or
streaking while still providing antimicrobial benefits in a hard
surface cleaner context, proper selection of the components in the
aqueous solution is essential. The polymeric biguanide induces no
incremental visible film or streak negatives when used in a
pre-moistened wipe comprising the composition pH and surfactant as
described herein to treat a hard surface. More preferably, the
pre-moistened wipe is selected such that in order to provide an
Extracompa.RTM. black shiny porcelain tile treated with the
pre-moistened wipe herein with a gloss-meter reading such that at a
95% confidence level, the polymeric biguanide induces a significant
enhancement of gloss, relative to identical compositions lacking
the polymeric biguanide, when tested with a BYK-Gardner
micro-TRI-gloss gloss-meter.RTM. using a 60.degree. angle setting.
Without being bound by theory, it is believed that the polymeric
biguanide compound acts as a wetting polymer at a pH of 7 or less
in the presence surfactant. As such, it functions as a hydrophilic
agent, helping evenly distribute the aqueous composition throughout
the surface to be treated. It is believed that the polymeric
biguanide forms a colorless, uniform film on the treated hard
surfaces, attenuating or masking the streaks and/or films due to
other components in the composition, or enhancing the shine/gloss
of the treated surface when the other components in the composition
do not cause streaking and/or filming issues.
[0156] The biguanide compound does not interact very strongly with
charged surfaces, meaning that the primary interaction is between
surfactants, solvents (i.e., cleaning agents) and the surface to be
treated. As a result, the biguanide compound has a lower tendency
to bind on hard surfaces and leave films and streaks. The wetting
ability of the polymeric biguanide material in this context is very
surprising given that the alternative cationic antimicrobial
actives, quaternary ammonium surfactants (`quats`), are very poor
wetting compounds. By quaternary ammonium surfactants, it is meant
all surfactants of the form R1R2R3R4N.sup.+, wherein R1 is a C8 to
C18 alkyl group, R2 and R3 are C1 to C18 alkyl groups, benzyl
groups or substituted benzyl groups and R4 is a methyl group. Such
materials are widely available commercially and are sold by Lonza
Corporation and Stepan Corporation as effective antimicrobial
compounds. Quaternary ammonium compounds exhibit hydrophobic
behavior in aqueous media. As such, they de-wet the surfaces being
treated. This leads to non-uniform cleaning and drying, and
undesirable accelerated aggregation of the solids on the surfaces
upon evaporation of the water from the aqueous composition. This
leads to high levels of streaks. Moreover, quaternary ammonium
compounds are highly charged chemical species that will bind to
negatively charged surfaces, including glass and ceramic. Once
bound to these surfaces, removal can require use of a second
treatment comprising anionic surfactants and the like, for removal
of the quaternary ammonium compounds (quats). This is highly
undesirable. In one-step cleaning applications, quats will build up
on negatively charged surfaces. The polymeric biguanide compounds,
within the framework provided by the compositions of this
invention, are excellent wetting agents and do not strongly bind
anionic surfaces. The polymeric biguanide surface film is clean and
strip-able, meaning that it is easily removed and replaced in
subsequent cleaning applications. Additionally, the hydrophilic
nature of the polymer helps the wetting of surfaces, which makes
next-time cleaning applications easier. In instances wherein the
polymeric biguanides are used to clean vertical tiles (for example
bathroom shower tiles), the compositions "sheet" water very well
ensuring even-ness of cleaning or easier rinsing of tiles.
[0157] Accordingly, the pre-moistened wipe is selected such that in
order to provide a black shiny porcelain tile, preferably an
Extracompa.RTM. black shiny porcelain tile, treated with the
pre-moistened wipe herein with a gloss-meter reading such that at a
95% confidence level, the polymeric biguanide induces a significant
enhancement of gloss, relative to identical compositions that
substitute quaternary ammonium surfactant for the polymeric
biguanide at equivalent weight concentrations, when tested with a
BYK-Gardner micro-TRI-gloss gloss-meter.RTM. using a 60.degree.
angle setting.
[0158] The magnitude of the gloss improvement provided by the
polymeric biguanides of the present invention, relative to similar
compositions not comprising polymeric biguanides, will depend on
the level of polymer incorporated. Increased levels of polymer will
provide increased gloss. The Applicant has found that it is
relatively straightforward to increase the gloss of untreated tiles
with the compositions herein when said compositions comprise at
least 0.5% polymeric biguanide and more preferably at least 0.75%
polymeric biguanide. As such, the pre-moistened wipe is selected in
order to provide an Extracompa.RTM. black shiny porcelain tile
treated with the pre-moistened wipe herein with a gloss-meter
reading such that at a 95% confidence level, a concentration of
0.5% polymeric biguanide by weight of the aqueous composition
induces a significant enhancement of gloss, relative to identical
compositions that do not comprise the polymeric biguanide, when
tested with a BYK-Gardner micro-TRI-gloss gloss-meter.RTM. using a
60.degree. angle setting.
[0159] Despite the hydrophilic behavior on surfaces, the polymeric
biguanides within the context of the compositions of the invention
are shown to exhibit strong antimicrobial properties comparable to
those of quaternary ammonium surfactants.
[0160] The disinfecting and/or antimicrobial performance of a given
pre-moistened wipe can be assessed using the standard protocol
required by governmental agencies in North America and Western
Europe. The results presented in the experimental section
illustrate the United States wipe protocol for achieving "hospital"
grade disinfectancy claims. Hospital grade disinfectancy represents
the strongest claim allowed by the United States Environmental
Protection Agency and has the most stringent requirements. It
requires complete biocidal effectiveness against two Gram negative
organisms, Salmonella cholerasuis and Pseudomonas aeruginosa, and
one Gram positive organism, Staphylococcus aureus. Various related
antimicrobial protocols exist in Europe and will be standardized
for the EU with the Biocidal Products Directive in the coming
years.
[0161] According to the present invention, the compositions are
selected so as to maximize the gloss on a standard black shiny
porcelain tile (described hereinafter). The Applicant has found
that the polymeric biguanide compound assists in gloss enhancement
or retention. More specifically, the gloss readings provided by
compositions that comprise the polymeric biguanide compound are
equal or better than the gloss readings provided by identical
compositions lacking the polymeric biguanide compound. The
compositions of the invention also provide gloss enhancement versus
similar compositions that comprise an equivalent weight
concentration of quaternary ammonium surfactant instead of the
polymeric biguanide. That is, the polymeric biguanide compound
preserves or enhances the shine benefits of the clean tiles.
[0162] Whist the effect of the biguanide compound applies to most
surfactants, use of low residue surfactants is beneficial in that
it delivers higher gloss readings for the compositions of the
invention. In order to influence the gloss-meter reading the type
surfactant for use in the composition to be applied onto the
substrate as described herein can be varied.
[0163] Packaging Form of the Pre-moistened Wipes
[0164] The pre-moistened wipes according to the present invention
may be packaged in a box, preferably in a plastic box.
[0165] In a preferred embodiment according to the present
invention, the pre-moistened wipes are provided in a stacked
configuration, which may comprise any number of wipes. Typically,
the stack comprises from 2 to 150, more preferably from 5 to 100,
most preferably from 10 to 60 wipes. Moreover the wipes may be
provided in any configuration folded or unfolded. Most preferably,
the wipes are stacked in a folded configuration.
[0166] Process for Cleaning a Surface
[0167] In a preferred embodiment, the present invention encompasses
a process of cleaning a surface, preferably a hard surface,
comprising the step of contacting, preferably wiping, said surface
with a pre-moistened wipe as described herein. In another preferred
embodiment of the present application, said process comprises the
steps of contacting parts of said surface, more preferably soiled
parts of said surface, with said pre-moistened wipe. In yet another
preferred embodiment said process, after contacting said surface
with said pre-moistened wipe, further comprises the step of
imparting mechanical action to said surface using said
pre-moistened wipe. By "mechanical action" it is meant herein,
agitation of the pre-moistened wipe on the surface, as for example
rubbing the surface using the pre-moistened wipe.
[0168] By "hard-surfaces", it is meant herein any kind of surfaces
typically found in houses like kitchens, bathrooms, or in car
interiors or exteriors, e.g., floors, walls, tiles, windows, sinks,
showers, shower plastified curtains, wash basins, WCs, dishes,
fixtures and fittings and the like made of different materials like
ceramic, vinyl, no-wax vinyl, linoleum, melamine, glass, any
plastics, plastified wood, metal or any painted or varnished or
sealed surface and the like. Hard-surfaces also include household
appliances including, but not limited to, refrigerators, freezers,
washing machines, automatic dryers, ovens, microwave ovens,
dishwashers and so on.
[0169] Test Methodologies
[0170] The test methodologies shown below illustrate the benefits
of the compositions of the present invention. They include a
filming and streaking test, a cleaning test and an antimicrobial
test.
[0171] Filming and Streaking Test
[0172] The filming/streaking performance of a given pre-moistened
wipe, can be assessed using the following test method:
[0173] Test Tile:
[0174] Extracompa.RTM. black glossy ceramic tiles, obtained from
Senio (via Tarroni 1 48012 Bagnacavallo (RA), Italy), with
dimensions 20 cm.times.20 cm.times.1 cm are employed as the test
surface. Prior to use, the tile surfaces are washed with soap and
water. They are then rinsed with about 500 ml distilled water and
wiped dry using paper towel, preferably using a low-binder clean
paper towel such as Scott.RTM. paper towels. Approximately five
milliliters of a 50% water, 50% 2-propanol solution mix is applied
from a squirt bottle to the surface of the tiles, spread to cover
the entire tile using clean paper towel and then wiped to dryness
with more paper towel. The application of the water/2-propanol
treatment is repeated and the tiles are allowed to air dry for five
minutes. The test tiles are positioned on a horizontal surface,
completely exposing the ceramic surface prior to testing. Prior to
initiating the wiping with test products, the tiles gloss readings
for the cleaned tiles are measured and recorded. The measurement is
performed using a `BYK-Gardner micro-TRI-gloss.RTM.` gloss-meter
using the 60.degree. angle setting. The BYK gloss-meter.RTM. is
manufactured by BYK-Gardner, catalog number GB-4520. The gloss of
each tile is analytically measured at the four corners and the
center of the tile, and the readings averaged. Tests are then
conducted on single test tiles with a total of 3 replicates to
ensure reproducibility.
[0175] Test Wipes:
[0176] Several test wipes are used to illustrate the benefits of
the compositions of the present invention. In all cases, wipes with
homogeneously distributed fibers are used. For purposes of making
comparisons, the basis weight is standardized at 60 gm.sup.-2 and
the load factor is set to 3.2 grams of aqueous solution per gram of
substrate, i.e., load factor=3.2.times.. Substrates are loaded at
least 4, preferably 7, days prior to the use; the wipes are stored
in sanitized bags or more preferably flow wrap packaging prior to
use. The purpose of the 4-7 day wait is to simulate commercial
production, and ensure proper wetting and swelling of fibers, and
provide sufficient time for the interaction between the aqueous
compositions and the test substrates to take place. The size of
experimental wipes is standardized at 26 cm*17 cm. Commercially
available competitive wipes are tested as is, i.e., taken directly
out of the package and used without alteration of any kind. The
competitive wipes tested all have similar, though not identical
dimensions as the experimental wipes intended to illustrate the
invention.
[0177] Wiping Procedure:
[0178] In each case, the wipes are first folded in half along the
longer side of the wipe. The wipes are then crimped between the
second and third fingers along the center part of the length of the
half wipe (the thumb is labeled as the first finger) so as to
ensure a good grip of the wipe, in such a manner so as to allow the
rest of the operator's hand to lie flat on surface of the wipes.
The now hand-held wipes is placed on the upper left hand corner of
the tiles, and then made to wipe the complete surface of the test
tiles in five un-interrupted wipe motions: first from left to
right, then right to left, then left to right, then right to left,
and finally left to right, all while progressively wiping down the
test tiles. The wiping motion is made continuously from side to
side as described above, and the final pass is completed past the
end of the tile. Wiping time duration is about 3-4 seconds per
tile.
[0179] Grading:
[0180] Grading is performed within 30 minutes after the tiles have
been wiped. For each test product (which consists of a substrate
and impregnated lotion), the wiping procedure described above is
performed five times. The tiles are allowed to air dry at ambient
conditions (20.degree. C.-25.degree. C. at a relative humidity of
40-50%) and then graded. Tiles are graded using visual grades and
gloss-meter readings. Two sets of measurements are selected since
the gloss-meter measurements allow for an analytical estimate of
filming, while the visual grades advantageously employ human visual
acuity for the identification of streaks and blotchy areas. The two
grades are viewed as complementary and usually show similar trends.
Visual grading is done with 5 expert panelists such that the
panelists do not know the identity of the specific products tested.
Visual grading of is conducted using a 0 to 4 scale, where 4
indicates a very streaky/filmy end result and 0 is a completely
perfect end result. Tile residue is analytically measured using a
BYK Gardner micro-TRI-gloss gloss-meter.RTM. using a 60.degree.
angle setting. The BYK gloss-meter is manufactured by BYK-Gardner,
catalog number GB-4520. This method results in 15 visual grade data
points being collected per treatment. Once the wipes tiles are dry
(air dried at ambient conditions), the gloss of each tile is
analytically measured with the gloss-meter at the four corners and
the center of the tile, and the readings averaged. The averages for
each of the 3 tiles tested are computed and then averaged. This
`average of averages` is then compared to the `average of averages`
computed on the pre-cleaned tiles; the standard deviation for gloss
loss (gain) is obtained using all 15 gloss readings, wherein each
gloss measurement recorded corresponds to the difference between
clean and treated tile. The overall appearance of tiles will depend
on both, the amount of streaking and filming on the tiles.
[0181] Cleaning Tests
[0182] The following cleaning protocol is employed to illustrate
the cleaning efficacy of the pre-moistened wipes of the present
invention. Due to variability between tests (slight differences in
tile placement, oven heating, time etc.), statistical significance
can only be assigned for groups of product run within a test set.
Each test set, as configured in the experiments described below,
consists of 4 product treatments. In these tests, statistical
significance is established at the 90% confidence level using a
one-tailed test (.alpha.=0.10), and pair-wise statistical treatment
of the samples.
[0183] Kitchen Dirt Cleaning:
[0184] The cleaning effectiveness of the wipes on kitchen dirt is
illustrated as follows:
[0185] Four (4) standard porcelain enamel tiles are soiled with
grease, consisting of partially polymerized oil and particulate
matter. The soiled tiles are then backed at 150.degree. C. for 40
minutes (after 20 minutes, the tiles are rotated 180.degree. so as
to ensure even-ness of baking) in a mechanical convection oven
(model 625 Freas.RTM.). The enamel plates are allowed to cool to
room temperature (.about.30 minutes) and then used immediately for
testing. Sponges with dimensions 14 cm.times.9 cm.times.2.5 cm
purchased from VWR Scientific, catalog No. 58540-047, cut to size
by cutting each sponge in thirds along the width of the sponge,
washed in a conventional washing machine with detergent and then
washed in plain water in a washing machine 3 times so as to strip
the sponge finishes. The sponges are then allowed to dry in a
working fume hood for 48 hours. The dimensions of the dry sponges
after air-drying are about 9 cm.times.4.5 cm.times.2.5 cm. Dry test
sponges are weighed (5.+-.1 grams). Four (4) sponges are placed in
a 903/PG Washability Tester (Sheen Instruments, Ltd (Surrey, United
Kingdom)). Pre-moistened wipes are then attached to the sponges
(without folding the pre-moistened wipe) so as to expose the wipe
to one of soiled enamel tiles placed in the 903/PG Washability
Tester. Cleaning is initiated and the number of strokes required
for complete soil removal is determined.
[0186] Each treatment is tested for cleaning a minimum of 4 times
and the mean number of strokes for cleaning and standard deviation
are computed. In these tests, statistical significance is
established at the 90% confidence level using a one-tailed test
(.alpha.=0.10), using pair-wise statistical treatment of the
samples.
[0187] Antimicrobial Tests for Pre-moistened Wipes
[0188] In a highly preferred embodiment, the compositions of the
present invention provide antimicrobial benefits. The antimicrobial
effectiveness of the wipes can be assessed using the following wipe
(disposable towelette) protocol:
[0189] 60 glass carriers are inoculated with bacteria, dried, and
then wiped (10 carriers per towelette) for 30 seconds with the
wipe. All are neutralized to stop the action of the antimicrobial,
and then incubated in media. 59 of the 60 carriers must be free of
bacteria, as demonstrated by clear media after incubation. The
exact details of inoculation, treatment, and subsequent assessment
can be found in Protocol PG12022201.TOW (Viromed), incorporated
herein by reference.
[0190] Experimental Data and Examples
[0191] The following examples are meant to exemplify compositions
used in a process according to the present invention but are not
necessarily used to limit or otherwise define the scope of the
present invention. The aqueous compositions are made by combining
the listed ingredients in the listed proportions to form homogenous
mixtures (solution weight % unless otherwise specified).
[0192] Pre-moistened Wipe Compositions
[0193] Several substrates are used to illustrate the invention. All
substrates have homogeneously distributed fibers, have dimensions
26 cm*17 cm, are initially dry, and are impregnated with lotion at
a 3.2.times. load factor. Four substrate types are evaluated as
follows:
[0194] Substrate 1 is a hydroentangled 60 g/m.sup.-2 substrate,
consisting of 60% polypropylene and 40% rayon fibers that is
substantially free of binders and latexes;
[0195] Substrate 2 is a hydroentangled 60 g/m.sup.-2 substrate,
consisting of 100% rayon fibers, that is substantially free of
binders and latexes;
[0196] Substrate 3 is a hydroentangled 60 g/m.sup.-2 substrate,
consisting of 100% polyester fibers, that is substantially free of
binders and latexes;
[0197] Substrate 4 is an air-laid, 60 g/m.sup.-2 substrate,
consisting of 70% pulp, 16% Lyocell.RTM., and 12% binder fibers
that are homogeneously distributed within the web.
[0198] The aqueous compositions A-Z-IV to be loaded on the
substrates are made starting from a base product lacking surfactant
and polymer/antimicrobial agent. The base products for these
compositions comprise: 0.05% C12-14 EO21, 0.5% citric acid, 2%
propylene glycol n-butyl ether (Dowanol PnB.RTM.), 8% ethanol and
0.1% perfume, and the remainder, excluding the hole left for
surfactant and antimicrobial agent, up to 100%, water. Surfactant
and antimicrobial agent are then incorporated into the base product
and the resulting compositions loaded onto the substrates as shown
in the table below. All compositions are found to have pH near
3.5.
[0199] Compositions AA-AI illustrate the benefits of the organic
acid comprising at least one hydroxyl group within the scope of
this invention. The base products for these compositions comprise:
0.22% C12-14 sulfobetaine, 0.05% C12-14 EO21, 0.5% acidifying agent
(except for compositions AG-AI), 2% propylene glycol n-butyl ether
(Dowanol PnB), 8% ethanol and 0.1% perfume, and the remainder,
excluding the hole left for polymeric biguanide, up to 100%,
water.
1 A B C D E F G H I J Surfactants (%) C12-14 0.22 0.22 0.22 0.22 --
-- -- -- -- -- sulfobetaine* C8-16 APG** -- -- -- -- 0.22 0.22 --
-- -- -- C12-16 -- -- -- -- -- -- 0.22 0.22 -- -- betaine***
C9-11EO6**** -- -- -- -- -- -- -- -- 0.22 0.22 Antimicrobial (%)
PHMB.sup..dagger. -- 0.3 -- -- -- 0.3 -- 0.3 -- 0.3
ADBAC.sup..dagger-dbl. -- -- 0.3 -- -- -- -- -- -- --
DADAC.sup..dagger-dbl..dagger-dbl. -- -- -- 0.3 -- -- -- -- -- --
SubstrateType 1 1 1 1 1 1 1 1 1 1 Binders/Latexes? No no no no no
No No no no no K L M N O P Q R S T Surfactants (%) C12-14 0.22 0.22
0.22 0.22 0.22 0.22 0.22 0.22 0.22 -- sulfobetaine* C12-14 -- -- --
-- -- -- -- -- -- 0.22 Amphoteric (V*) Antimicrobial (%)
PHMB.sup..dagger. -- 0.3 -- -- 0.3 -- -- 0.3 -- --
ADBAC.sup..dagger-dbl. -- -- 0.3 -- -- 0.3 -- -- 0.3 -- Substrate
Type 2 2 2 3 3 3 4 4 4 1 Binders/Latexes? No no no no no No yes yes
yes no U V W X Y Z ZZ ZZZ Z-IV Surfactants (%) C12-14 Amphoteric
0.22 -- -- 0.22 -- -- -- (V*) C9-11EO6**** 0.22 0.22 -- 0.22 -- --
C12-14 sulfobetaine* -- -- -- -- -- 0.22 -- Coco betaine*** -- --
-- -- -- 0.22 Soya sucrose ester -- -- -- -- -- -- -- 0.22 0.22
(VI*) Polymer (%) PHMB.sup..dagger. 0.3 -- 0.3 1 1 1 1 -- 0.3
SubstrateType 1 1 1 1 1 1 1 1 1 Binders/Latexes? no no no no no No
no no no AA AB AC AD AE AF AG AH AI Surfactants (%) C8-16 APG**
0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22 Organic Acid (%)
Tartaric acid 0.5 0.5 -- -- -- -- -- -- -- Lactic acid -- -- 0.5
0.5 -- -- -- -- -- DAGS.sup..gradient. -- -- -- -- 0.5 0.5 -- -- --
Hydrochloric acid -- -- -- -- -- -- -- -- -- Alkalinity Agent (%)
Sodium carbonate -- -- -- -- -- -- -- -- 0.05 Polymer (%)
PHMB.sup..dagger. -- 0.3 -- 0.3 -- 0.3 -- 0.3 0.3 Substrate Type 1
1 1 1 1 1 3 3 3 Binders/Latexes? no no no no no no no no no
*Cocoamido propyl sulfobetaine made by Degussa-Goldschmidt under
the tradename Rewoteric AM CAS 15-U .RTM. **Alkyl PolyGlucoside
made by Cognis under the tradename Plantaren 2000 .RTM. ***C12-16
dimethyl betaine made by Albright & Wilson under the trade name
Empigen BB/L .RTM. ****Alkyl ethoxylate (6) made by Shell Chemical
under the trade name Neodol 91-6 .RTM. (V*) N-coconut fatty acid
amidoethyl N-hydroxyethyl amino propionic acid, sodium salt, made
by Degussa-Goldschmidt under the trade name Rewoteric AM KSF 40
.RTM. (VI*) C16-18 sucrose ester made by Procter & Gamble under
the trade name SEFA 16-18S .RTM. .dagger.Poly (hexamethylene
biguanide) made by Avecia under the tradename Vantocil IB .RTM.
.dagger-dbl.Alkyl Dimethyl Benzyl Ammonium Chloride made by Lonza
under the tradename Barquat 4280 .RTM.
.dagger-dbl..dagger-dbl.DiAlkyl Dimethyl Ammonium Chloride made by
Lonza under the tradename Bardac 2280 .RTM. .gradient.Diacids:
Adipic, glutaric and succinic manufactured by Rhodia as a
commercial mixture.
[0200] As an illustration, the filming and streaking profiles for
several European and North American competitor antimicrobial wipes
were also run. Each competitor employs quaternary ammonium
surfactant to achieve antimicrobial benefits. In the case of the
North American competitors, the amount of quaternary ammonium
surfactants a weight percent of the lotion is 0.28% for Lysol.RTM.
(Reckitt) and 0.29% for the Clorox wipes. The competitors are:
Product C1 corresponding to Dettox.RTM. antimicrobial wipes (UK),
product C2 corresponding to Ajax.RTM. antimicrobial wipes
(Belgium), product C3 corresponding to Lysol.RTM. antimicrobial
wipes (USA) and product C4 corresponding to Clorox.RTM.
antimicrobial wipes.
[0201] Filming and Streaking Experimental Results
[0202] The data below are tabulated in terms of gloss-meter
measurements and visual grades. As indicated in the experimental
section, the gloss-meter readings (mean treatment .delta.) are
computed as a difference in gloss between tiles treated with the
experimental compositions herein and that for the corresponding
clean, untreated tiles. The clean tiles all have 60.degree. angle
gloss readings between 92 and 94. Gloss losses (gains) are computed
as differences in readings. Positive values represent a loss in
gloss. Negative values ( ) suggest a gain in gloss. The mean gloss
loss (gain) caused by treatments versus untreated tiles (mean
treatment .delta.), and associated statistical significance are
calculated. The mean gloss (gain) on tile caused by the addition of
PHMB (mean .delta.(PHMB-noPHMB)) and associated statistical
significance is also reported. The mean gloss (gain) on tile caused
by poly(hexamethylene biguanide) versus quaternary ammonium
surfactant (mean .delta.(PHMB-Quat)) and statistical significance
are also reported.
[0203] In these tests, statistical significance is established at
the 95% confidence level (.alpha.=0.05), using a one-tailed test
and pair-wise statistical treatment of the samples. All samples are
assumed to exhibit a normal distribution with equal variances.
Using the raw data, t-statistics are calculated and compared to the
t-critical statistic. When the calculated t-test exceeds
t-critical, the samples are `significantly different. When
t-calculated is less than t-critical, the samples are not
`significantly` different. The direction of significance is
determined by the sign of the mean differences (i.e., `mean
treatment .delta.`, `mean .delta.(PHMB-noPHMB)` or `mean
.delta.(PHMB-Quat)`. For example, if the treatment mean gloss for a
treatment is higher than that of the untreated tile, and
t-calculated exceeds t-critical, then the data suggest that at a
95% confidence level (.alpha.=0.05) the treatment has a
significantly higher gloss than the untreated tile. The statistic
treatment of dependent paired samples (mean treatment .delta.) and
independent paired samples ((PHMB-noPHMB or mean
.delta.(PHMB-Quat)) can be found in Anderson, Sweeney and Williams,
Statistics for Business and Economics, 6.sup.th edition, West
Publishing Company, 1996, incorporated herein by reference. The
statistics can be conveniently run using the statistical function
in Microsoft Excel.TM..
[0204] The streaking grades are provided as 0-4 visual grades using
5 expert panelists. The mean grade and standard deviations are
computed. The significance of differences in visual grading is
defined in analogous manner as described for the gloss-meter
test.
[0205] For products C1, C2, C3 and C4, no data for base products,
i.e., identical liquid compositions lacking the antimicrobial
active, can be obtained. In this instance the difference in gloss
due loss (gain) due to the experimental treatments is compared to
the difference in gloss loss due to the commercial products (mean
.delta.(B-competitor) and mean .delta.(F-competitor)). A comparison
of the filming/streaking on tile caused by the prototypes of the
present invention (treatments B and F), relative to that of the
commercially sold products, is then made.
2 A B C D E F G H I J Gloss Mean treatment .delta. 0.5 0.2 1.9 13.6
1.1 (0.5) 1.8 0.7 0.5 0.3 Treatment .delta. 0.28 0.28 0.6 3.4 0.6
0.29 0.35 0.33 0.49 0.43 Std. Dev. Mean .delta. Ref. (0.3) Ref.
(1.6) Ref. (1.1) Ref. (0.2) (PHMB-noPHMB) .delta. (PHMB-noPHMB)
Ref. Yes Ref. Yes Ref. Yes Ref. No Significant? Mean .delta. Ref.
(1.6) (13.4) (PHMB-Quat) .delta. (PHMB-Quat) Ref. Yes Yes
Significant? Visual Mean grade 0.6 0.3 2.5 3.6 0.2 0.1 0.6 0.0 2.2
0.9 Treatment .delta. 0.46 0.2 0.55 0.48 0.23 0.11 0.22 0.0 0.73
0.73 Std. Dev. Mean .delta. Ref. (0.3) Ref. (0.2) Ref. (0.6) Ref.
(1.3) (PHMB-noPHMB) .delta. (PHMB-noPHMB) Ref. Yes Ref. No Ref. Yes
Ref. Yes Significant? Mean .delta. Ref. (2.3) (3.3) (PHMB-Quat)
.delta. (PHMB-Quat) Ref. Yes Yes Significant? K L M N O P Q R S
Gloss Mean treatment .delta. 0.9 0.0 1.5 1.4 0.3 5.6 0.7 2.5 8.1
Treatment .delta. 0.53 0.24 0.41 0.43 0.46 0.8 0.64 0.56 2.79 Std.
Dev. Mean .delta. Ref. (1.0) Ref. (1.2) Ref. 1.9 (PHMB-noPHMB)
.delta. (PHMB-noPHMB) Ref. Yes Ref. Yes Ref. Yes Significant? Mean
.delta. Ref. (1.5) Ref. (5.3) Ref. (5.6) (PHMB-Quat) t-statistic
.delta. Ref. Yes Ref. Yes Ref. Yes .delta. (PHMB-Quat) Visual Mean
grade 0.9 0.4 1.9 0.2 0.1 1.8 1.5 2.5 2.6 Treatment .delta. 0.43
0.25 0.6 0.18 0.15 0.54 0.56 0.46 0.74 Std. Dev. Mean .delta. Ref.
(0.5) Ref. (0.2) Ref. 1.0 (PHMB-noPHMB) .delta. (PHMB-noPHMB) Ref.
Yes Ref. No Ref. No Significant? Mean .delta. Ref. 1.5 Ref. Ref.
(PHMB-Quat) .delta. (PHMB-Quat) Ref. Yes Ref. Yes Ref. Yes
Significant? T U V W X Y Z ZZ ZZZ Z-IV Gloss Mean treatment .delta.
1.5 (0.2) 1.6 0.5 (9.0) (4.1) (4.1) (3.9) 0.6 (1.9) Treatment
.delta. 0.45 1.32 0.59 0.5 ? 0.81 0.80 0.90 0.32 0.1 Std. Dev. Mean
.delta. Ref. (1.7) Ref. (1.1) (10.5) (5.7) (4.6) (5.7) Ref. (2.5)
(PHMB-noPHMB) vs. T vs. V vs. A vs. G .delta. (PHMB-noPHMB) Ref.
Yes Yes Yes Yes Yes Yes Yes Ref. Yes Significant? Visual Mean grade
0.9 0.4 2.2 0.9 1.2 0.5 0.5 0.8 0.9 0.1 Treatment .delta. 0.43 0.25
0.73 0.73 0.33 0.27 0.27 0.36 0.22 0.14 Std. Dev. Mean .delta. Ref.
(0.5) Ref. 1.3 0.3 (1.7) 0.0 (1.0) Ref. 0.8 (PHMB-noPHMB) .delta.
(PHMB-noPHMB) Ref. Yes Ref. Yes No Yes No Yes Ref. Yes Significant?
vs. T vs. V vs. A vs. G E F AA AB AC AD AE AF AG AH AI Gloss Mean
treatment .delta. 1.1 (0.5) 0.0 (0.8) 0.4 (0.2) 1.3 0.0 0.6 (2.8)
4.4 Treatment .delta. 0.6 0.29 0.49 0.28 0.22 0.40 0.66 0.42 0.42
0.27 2.18 Std. Dev. Mean .delta. Ref. (1.6) Ref. (0.8) Ref. (0.6)
Ref. (1.3) Ref. (3.4) N/A (PHMB- noPHMB) .delta. (PHMB- Ref. Yes
Ref. Yes Ref. Yes Ref. Yes Ref. Yes N/A noPHMB) Significant? Visual
Mean grade 0.2 0.1 0.4 0.4 0.2 0.1 2.0 0.4 0.7 0.3 3.6 Treatment
.delta. 0.23 0.11 0.13 0.13 0.16 0.12 0.31 0.13 0.21 0.10 0.22 Std.
Dev. Mean .delta. Ref. (0.2) Ref. 0.0 Ref. (0.1) Ref. (1.6) Ref.
(0.4) N/A (PHMB- noPHMB) .delta. (PHMB- Ref. No Ref. No Ref. No
Ref. Yes Ref. Yes N/A noPHMB) Significant? A B C1 C2 C3 C4 Gloss
Mean treatment .delta. 0.2 (0.5) 1.7 6.8 1.2 8.1 Treatment .delta.
0.28 0.29 0.83 1.54 0.45 2.79 Srd. Dev. Mean .delta. (B-competitor)
Ref. 1.3 6.6 1.0 7.9 .delta. (B-competitor) Ref. Yes Yes Yes Yes
Significant? Mean .delta. (F-competitor) Ref. 2.0 7.3 1.7 8.6
.delta. (F-competitor) Ref. Yes Yes Yes Yes Significant? Visual
Mean treatment .delta. 0.3 0.1 2.5 2.9 2.4 3.2 Treatment .delta.
0.2 0.11 0.93 0.68 0.64 0.53 Srd. Dev. Mean .delta. (B-competitor)
Ref. 2.2 2.6 2.1 2.9 .delta. (B-competitor) Ref. Yes Yes Yes Yes
Significant? Mean .delta. (F-competitor) Ref. 2.4 2.8 2.3 3.1
.delta. (F-competitor) Ref. Yes Yes Yes Yes Significant?
[0206] Data Interpretation for Filming and Streaking:
[0207] All of the treatments exemplifying the invention (treatments
B, F, H, J, L, O, U and W) show gloss reading losses of 1% or less.
Treatment F and treatment Z-IV show a statistically significant
gloss enhancement versus untreated tile (treatment E and treatment
ZZZ). All of the treatments exemplifying the current invention have
visual grades below 1.0, suggesting good consumer appeal.
[0208] Excluding the results obtained for compositions comprising
quaternary ammonium antimicrobial agents which are not part of the
present invention (treatments C, D, M, P and S), the gloss and
visual grade results for the identical aqueous compositions
impregnated on substrates 1, 2 and 3 are significantly better than
for substrate 4 (compare results for treatments B, L and O with
those for treatment R). This illustrates the benefits of using a
substantially binder- and latex-free substrate.
[0209] The magnitude filming and streaking benefits provided by the
compositions of the present invention are insensitive to the
chemical composition of the substrate. The effect of higher release
for the 100% synthetic substrate, which results in lower gloss for
treatment N versus treatments A and K (all without PHMB), is
completely negated by addition of the polymer. The data and
associated trends for substrates 1, 2, and 3 are similar (see
results for treatments A, B and C, treatments K, L and M, and
treatments N, O and P), despite the fact that the chemical
composition of the three substrates spans the full range: from 100%
synthetic to 100% non-synthetic.
[0210] 0.3% PHMB provides gloss enhancement versus identical
compositions that do not comprise PHMB (compare results for
treatments A and B, E and F, G and H, K and L, and N and O, T and
U, V and W, ZZZ and Z-IV, and AH and AI). Significant visual grade
benefits are also achieved in all but two cases (see results for
treatments A and B, E and F, G and H, I and J, K and L, and T and
U, ZZZ and Z-IV, and AH and AI).
[0211] All compositions that comprise 1% PHMB (treatments X, Y, Z,
ZZ) have significantly higher gloss on tile than untreated tiles,
and significantly higher gloss on tile than similar compositions
that do not comprise PHMB.
[0212] All compositions of the invention show significant gloss and
visual grade advantages relative to identical compositions that
substitute quaternary ammonium surfactant for PHMB (compare the
gloss readings and visual grades for treatments B, C and D, L and M
and N and O).
[0213] The visual grade results provided by each of the low residue
surfactants are significantly better than that provided by the "non
low residue" surfactant. Additionally, PHMB can strongly impact the
streaking due to the preferred non-low residue surfactant (see
results for treatments I and J).
[0214] The gloss readings and visual grades for the preferred
pre-moistened wipes of the present invention are significantly
better than each of the competitive products. It is interesting to
note that composition C3, which shows the best mean gloss reading
and mean visual grade among the competitors, comprises a
hydroentangled (binder-free) substrate. Composition C4, which has
the worst mean gloss reading and mean visual grade among the
competitors, comprises a substrate with binder.
[0215] All compositions comprising an organic acid show polymeric
biguanide-induced gloss benefits (see F vs E, AB vs AA and AD vs.
AC, AF vs. AE). Additionally, composition AF shows a significant
visual grade enhancement versus composition AE. The visual grade
differences are smaller for the other treatments because of the
good appearance of compositions not comprising PHMB.
[0216] Compositions AH and AI are near neutral pH (6). Composition
AI, which comprises PHMB shows significantly improved gloss and
visual readings on tile versus composition AH. Composition AJ,
which has an alkaline pH, shows significantly worse gloss and
visual readings on tile versus composition AI.
[0217] Cleaning Test Results
[0218] To illustrate the preferred embodiment wherein substrates
that comprise at least 20% synthetic fibers are employed,
compositions B, L, O and R are tested for tough kitchen dirt. As
the chemical composition of the lotions and the substrate load
factors are all standardized, the tests directly measure substrate
effects on cleaning.
3 Kitchen Dirt Soil B L O R Mean # strokes to clean 39.5 100* 19
100* Std. Dev. (strokes) 2.6 N/A 5.3 N/A Mean .delta. (B-O) 20.9
.delta. (B-O) Significant? Yes *Complete removal was not achieved
in 100 strokes (at least one replicate)
[0219]
4 Kitchen Dirt A B E F Mean # strokes to clean 21.5 24.5 23.5 18.0
Std. Dev. (strokes) 3.0 3.0 4.1 1.6 Mean # strokes A-B/E-F 3.0 5.5
A-B and E-F Significant? No Yes
[0220] Wipes L and R, which comprise substrate that do not contain
synthetic fibers, do not consistently clean the soil within 100
strokes. Wipe B, which comprises a substrate with 60% synthetic
fibers, completely cleans the soil in 39.5 strokes, significantly
better than wipes L and R, which do not include synthetic fibers.
Wipe O, which comprises a substrate with 100% synthetic fibers
cleans the soil in 19 strokes, significantly better than substrate
B. The cleaning effectiveness ranking is therefore: 100%
synthetic>60% synthetic>0% synthetic.
[0221] Wipes A and B, which differ only in that B also comprises
PHMB, do not show significant differences in cleaning differences.
Wipe F, which comprises PHMB, shows a significant cleaning benefit
versus wipe E, which is identical in all respects to wipe F, except
that it does not comprise PHMB. The data illustrate that PHMB can
be used in selected compositions to improve cleaning
performance.
[0222] Antimicrobial Effectiveness:
[0223] In a highly preferred embodiment, the compositions of the
present invention also provide antimicrobial benefits. The results
below were obtained for a composition consisting of substrate 1
loaded at 3.2.times. with a composition similar to B at three
different levels citric acid was used in this test.* The study was
conducted by qualified Viromed technicians at Viromed (Minnesota,
USA), a U.S. EPA approved antimicrobial laboratory.
5 Citric Acid level 0.25% 0.50% 0.75% Staphylococcus aureus 0/60
0/60 0/60 Pseudomonas aeruginosa 0/60 0/60 0/60 Salmonella
cholerasuis 0/60 0/60 0/60 * Perfume level is 0.175%, ethanol level
is 2%
[0224] Under each of the conditions studied, the compositions were
fully biocidal against the target organisms. The level of PHMB in
these compositions (0.3%) is virtually identical to the level of
quaternary ammonium surfactant utilized by Lysol.RTM. and
Clorox.RTM. wipes to make similar antimicrobial claims.
* * * * *