Note: Descriptions are shown in the official language in which they were submitted.
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WIPING ARTICLE
Technical Field
The present invention relates to a wiping article which
contains dried surfactant and which can be used when wet or
dry for the cleaning or dusting of hard surfaces.
Background to the Invention and Prior Art
Cleaning sheets impregnated with a surfactant component are
disclosed, for example, in EP 353 014 which describes a
wiping article suitable for use in cleaning soiled surfaces
in the presence of water. The article comprises first and
second substrate layers (typically water-permeable sheets of
fibrous material such as cellulose) with solid surfactant
particles sandwiched between the layers. Within the article
at the interface between the substrate layers is a
discontinuous covering of heat-sealable material such as
polyethylene which bonds the layers together. The covering
also provides a partial barrier which shields the surfactant
particles from water permeating through the substrate
layers, and therefore retards dissolution and leaching of
the surfactant when the wiping article is brought into
contact with water.
The wiping article of EP 353 014 is not suitable for use in
the absence of water.
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US 6,376,046 describes a detergent-impregnated article
comprising a detergent-retaining layer which is formed from
bulky hydrophobic material capable of retaining a large
quantity of detergent and which is sandwiched between
detergent-gradual-releasing layers formed from a fibre
aggregate of higher density than the retaining layer. The
capillary action of the fibres of the release layers retards
detergent release from the retaining layer. The article is
designed to be used without water since the impregnated
detergent itself contains at least 50% by weight water.
A problem with the wiping article of US 6,376,046 is that
the impregnated detergent is already pre-diluted with water
to a fixed concentration when it is incorporated into the
article. For some tough cleaning applications, it may be
desirable to use a higher concentration of detergent.
The present invention provides a wiping article that is
equally suitable for use in the presence or absence of
water.
Summary of the Invention
The present invention provides a wiping article which is
suitable for the cleaning or dusting of hard surfaces, the
article comprising a laminated substrate having a core layer
sandwiched between dusting layers, the core layer comprising
an absorbent fibrous matrix entrapping dried surfactant, and
the dusting layers comprising a polymeric fibrous web having
a capillary structure which permits uptake of water and
release of the surfactant when the article is wetted.
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When dry, the wiping article of the invention is especially
effective for the entrapment and removal of dust and other
particulate soil. When wetted, the wiping article of the
invention is especially effective for cleaning and
degreasing.
The wiping article of the invention has a number of
advantageous properties. In particular, it provides a
significant cost benefit to the manufacturer because it does
not require expensive packaging technology, unlike
conventional "wet wipes", which will dry out and lose
functionality unless maintained in airtight sealed
conditions.
The wiping article of the invention also provides
significant cost benefits to the consumer, because of its
dual functionality and the fact that it can be re-used.
Flexibility of usage is also improved since in wet cleaning
applications the consumer decides the level of water to be
applied to the article. Therefore the concentration of
available surfactant which is generated by the wetting
process can be tailored according to the degree of soiling
and nature of the surface to be treated.
Detailed Description of the Invention
The wiping article of the invention is designed in
particular for the cleaning of hard surfaces. By "hard
surfaces" is meant those surfaces which are typically found
in the household. Examples include furniture surfaces,
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kitchen worktops, sinks and appliances, bathroom fixtures
and fittings, wall and flooring surfaces.
The wiping article of the invention comprises a laminated
substrate having a core layer sandwiched between dusting
layers.
The core layer comprises an absorbent fibrous matrix.
Preferably the absorbent fibrous matrix is formed from
cellulosic fibres, such as pulp and rayon. Wood pulp fibres
are most preferred.
The dusting layers comprise a polymeric fibrous web having a
capillary structure which permits uptake of water and
release of the surfactant when the article is wetted.
Preferably the polymeric fibrous web is formed from
polyolefinic fibres, such as C2_1o polyolefins or copolymers
thereof, especially C2_4 polyolefins such as polyethylene
and polypropylene. Polypropylene fibres are most preferred.
Suitable laminated substrates which may be used to form the
wiping article of the invention are commercially available
and may be formed by many processes such as, for example,
meltblowing processes, spunbonding processes,
hydroentangling, airlaid and bonded carded web processes.
A commercially available example of a suitable laminated
substrate which may be used to form the wiping article of
the invention is Akena 4SQ ex Orlandi. This is a laminated
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material with a layer of wood pulp fibres sandwiched between
layers of polypropylene fibres.
In the wiping article according to the invention, the core
layer of the laminated substrate entraps dried surfactant.
This may be achieved by a process of impregnating the
laminated substrate with a solution of the surfactant in a
suitable solvent, followed by heating of the impregnated
substrate in order to drive off the solvent and thereby
concentrate the surfactant in dried form into the core layer
of the laminated substrate.
Suitable surfactants to be used in the wiping article
according to the invention include any surfactant known to
those skilled in the art like nonionic, anionic, cationic,
amphoteric and/or zwitterionic surfactants. Preferred
surfactants to be used are the amphoteric and/or
zwitterionic surfactants.
Amine oxides are particularly preferred for use in the
wiping article of the invention since they are mild, pH
neutral and stable to oxidation. They are also especially
effective at cleaning and degreasing when the wiping article
is wetted, even when they are incorporated into the wiping
article at low levels.
Preferably amine oxide is used as the sole surfactant
component in the wiping article of the invention.
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Suitable amine oxides to be used in the wiping article of
the invention may be generally described as those tertiary
amine oxides of the formula RZR'NO, in which each R is a
lower alkyl group, for instance an alkyl group having from 1
to 3 carbon atoms, preferably methyl, and R' is a long chain
alkyl group, for instance an alkyl group having from 8 to 24
carbon atoms, preferably from 8 to 18 carbon atoms.
In the wiping article of the invention, the total content of
dried surfactant (preferably amine oxide) suitably ranges
from 0.1 to 5%, preferably from 1 to 4%, more preferably
from 1.5 to 3% (by weight based on total weight of the
wiping article).
The wiping article of the invention is preferably supplied
to the consumer in the form of a pre-cut roll. This is a
convenient and cost-effective product format which enables
the consumer to tailor the size and thickness of product
used more easily than with a conventional "stack" of wipes
which have a predetermined size.
The wiping article of the invention can contain other
optional ingredients which aid in performance and consumer
acceptability.
Examples include: preservatives, perfumes, colours and dyes,
hygiene agents, and mixtures thereof.
The invention will now be illustrated by the following non-
limiting Example, in which all percentages are by weight
based on total weight, unless otherwise indicated.
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EXAMPLE
A wiping article according to the invention is prepared by
spraying an aqueous solution of amine oxide onto a dry
substrate having a 3-layer structure with two outer layers
of polypropylene "sandwiching" an inner core layer of wood
pulp (commercially available as Akena 4 SQ, ex Orlandi).
After the substrate has absorbed the aqueous solution of
amine oxide homogeneously, it is gently heated between 50
and 90°C in a ventilated oven, to allow a.homogeneous
evaporation of the water, and a homogeneous dispersion of
the dried amine oxide in the substrate.
After the water has completely evaporated, the wiping
article is ready to be used, and contains approximately 50mg
of dried amine oxide per 1.8g of dry substrate.
Evaluation of the wiping article showed that it gave
excellent dusting performance when dry, as well as cleaning
and degreasing performance when wetted with water.
