The invention relates to a method for applying a lotion to a surface
of an absorbent article, said method comprising the steps of: placing the surface
of the absorbent article in the proximity of a spraying apparatus comprising a spray
head having an orifice and pushing the lotion through the spray head orifice.
BACKGROUND ART:
Absorbent articles having lotion applied on e.g. the topsheet have
been known within the area for quite some time now. By applying lotion on an absorbent
article such as a diaper, an incontinence product, a sanitary napkin or the like,
added value is given to the product.
As described in WO 96/16682, the lotion, or similar, could be placed
on the topsheet of a diaper. In this manner, the lotion is said to add barrier properties
to the skin, reducing the irritation caused by contact with faeces.
Further back in time, similar use of lotions was known e.g. through
US 3,896,807, which describes how the surface of a diaper can be furnished with
an emulsifiable phase which upon exposure to moisture will form a water/oil (W/O)
or oil/water (O/W) emulsion. During use of the product, the emulsion will transfer
to the user's skin and will act as a vehicle for adding skin caring substances to
the user's skin.
In earlier published literature, several examples are given of how
to apply the lotion on absorbent articles.
In WO 96/16681 spraying, printing (e.g. flexographic printing), coating
and extrusion are mentioned as examples of application methods. With the spray technique,
it is said to be possible to spray patterns having a dimension of 9x18 cm.
In WO 98/24390 and WO 99/45974, slot coating, extrusion coating, gravure
coating, spraying and printing are mentioned. The lotion can be applied in stripes,
squares, dots or spirals.
WO 00/48544 describes a bit more thoroughly the techniques used to
apply lotion on absorbent articles. More specifically, spraying is described. When
spraying, the lotion is propelled through a nozzle by means of air. However, it
can also be propelled through the nozzle substantially without the use of air. Further,
it is described that the nozzle can be mechanically manipulated during spraying
to form patterns such as spirals, squares, stripes or circles. In order to achieve
a desired pattern such as a square, the nozzle itself needs to be altered. It is
also stated that the stripes have a minimum with of 0.1 inches.
The existing spray technique offers some advantages to the producer
of absorbent articles wanting to give added values to absorbent articles. However,
several disadvantages still exist that prior art has failed to remove.
When the lotion is sprayed through the orifice of the nozzle at high
speed, it is subjected to a high amount of stress. The stress is not only purely
mechanical stress, but is also caused by pressure differences. This causes the lotion
to turn into an aerosol fully or partly, something that greatly affects the quality
of the applied pattern and the flexibility of the process.
Even if it is possible to make patterns such as spirals, stripes or
circles, the applied pattern becomes diffuse in the periphery and the aerosolised
spray string makes it difficult to add lotion in an exact manner.
The nozzle of the spray head needs to be in close proximity to the
sprayed surface. This prevents the spray string from being spread too much in an
uncontrolled manner. However, this is a severe limitation to process flexibility
since even if the slightest amount of aerosol is formed, it will complicate the
handling and the flexibility of the process.
The fine droplets from the aerosol which lie in the periphery of the
sprayed string can easily be sucked down into the absorbent core by the capillary
forces of the absorbent core or an acquisition layer. This reduces the absorbent
capacity and the acquisition rate of the absorbent article. Accordingly, it is important
to keep the lotion on the surface of the absorbent article.
From a process point of view, it is difficult to handle aerosols when
manufacturing absorbent articles. Reducing the amount of aerosol vastly reduces
the required amount of cleaning and maintenance of the production equipment.
Consequently, there is a need for a method of applying lotion to absorbent
articles in a simple and efficient manner. Hence, it is an object of the current
invention to solve the above-mentioned problems and to provide an improved method
for applying lotion to absorbent articles. It is also an object of the invention
to provide an absorbent article having lotion arranged in a well-defined application
pattern.
DISCLOSURE OF INVENTION:
The current invention provides a method of applying lotion to an absorbent
article. The method of the invention is distinguished in that the lotion is sprayed
as a continuous fiberised string.
The term "fiberised string" means that the lotion is in the form of
a continuous string and that no amount of aerosol is formed. In contrast to ordinary
lotion which is sprayed in a continuous pattern, the lotion sprayed as a fiberised
string forms no aerosol or droplets when leaving the spray head orifice. The lotion
can be laid in an intermittent pattern or in a continuous pattern. However, the
string in itself is still continuous. In addition, the fiberised string is relatively
thin as compared to ordinary sprayed strings.
More specifically, the invention concerns a method for applying a
lotion to a surface of an absorbent article, said method comprising the steps of:
placing the surface of the absorbent article in the proximity of a spraying apparatus
comprising a spray head having an orifice; pushing the lotion through the spray
head orifice and propelling the lotion to the surface as a continuous fiberised
string.
The term "proximity" should not be taken to mean that the spraying
apparatus needs to be in direct contact or even close to the surface of the absorbent
article. In accordance with the invention, the spray head and the spraying apparatus
can be separated by several meters of hose or pipe or similar. The term proximity
should be interpreted as indicating a correlating relationship between the surface
of the absorbent article, the spray head and the spraying apparatus.
By propelling the lotion as a continuous fiberised string instead
of spraying in stripes or ordinary lines, several advantages are obtained. Due to
the use of a fiberised string, the spray head can be placed within a wide variety
of distances from the surface of the absorbent article. In one embodiment of the
invention the surface is placed at a distance of 15-300 mm from the spray head.
Several different kinds of spray heads can be used. In one embodiment
of the invention the lotion is propelled from the orifice by an air stream that
is separated from the orifice. In another embodiment of the invention the lotion
is sprayed with a velocity of at least 80 m/min.
In a preferred embodiment of the invention the lotion is propelled
to the surface of the absorbent article as a spiral continuous fiberised string.
The invention makes it possible to spray very thin fiberised strings
of lotion. This saves lotion as well as prohibits blocking of e.g. the topsheet
of the absorbent article. In one embodiment of the invention the fiberised string
has a diameter of less than 2.2 mm, preferably less than 1 mm and most preferably
less than 0.75 mm.
Surprisingly, the inventor has found that by using spray equipment
normally used for spraying hot-melt adhesive and a lotion with an elastic behaviour
measured by storage modulus G'>0.2Pa measured at 55°C, preferably a storage modulus
G'>0.6Pa measured at 55°C, remarkable results are achieved.
Using lotion with a storage modulus G'>0.2Pa measured at 55°C combined
with this technique offers the possibility of processing the lotion at high temperatures
without lotion disruption or the formation of lotion aerosols or droplets. This
prohibits the lotion from forming lumps due to processing in temperatures close
to the lotion melting point. Such lumps could otherwise cause blockage of tubes
or nozzles.
The technique also makes it possible to obtain a cleaner environment
around the process. By eliminating the formation of aerosols due to lotion disruption,
less cleaning and less maintenance is required.
The spray technique in accordance with the invention and the specified
lotion parameters make it possible to offer a more flexible production than with
earlier spray techniques or techniques such as slot-coating. Moreover, the invention
makes it possible to spray from a longer distance than before and to apply more
exact patterns on the surface of the absorbent article. As an example, it is now
possible to spray the lotion in three-dimensional-like patterns, stacking several
strings on each other and forming a web-like lotion pattern.
Due to its elastic behaviour, the lotion is prevented from being sucked
into the absorption core by capillary action. Instead, the lotion stays on the topsheet
of the absorbent article.
In one embodiment of the invention, a spray head, is used to apply
lotion on an absorbent article, the spray head comprising an orifice where said
lotion passes during use. Several air stream outlets are placed around and separated
from the orifice so that, during use, air streams propel the lotion in a continuous
fiberised string away from the orifice and the spray head.
The spray head is used in combination with a spraying apparatus, to
apply lotion on an absorbent article.
The lotion is pushed through the orifice of the spray head and the
nozzle and then propelled by separated air streams against the surface of the absorbent
article. The air streams are arranged symmetrically around the orifice of the nozzle.
The air streams are separated from the orifice, which means that the lotion and
the air do not leave the nozzle from the same orifice.
The lotion can be applied to the topsheet of the absorbent article,
to cuffs or to any other surface or surfaces of the absorbent article.
In accordance with the invention, it is also possible to form very
thin fiberised strings. The fiberised strings can have a diameter of less than 2.2
mm, preferably of less than 1 mm and most preferably of less than 0.75 mm.
When compared to conventional application patterns with strips of
a width dimension in the order of 2.5-5 mm, the small fiberised strings give the
opportunity to add lotion to the topsheet of the absorbent article without risking
blocking the topsheet. An application pattern coating a large percentage of the
topsheet area will reduce the acquisition rate of the absorbent article and indirectly
the absorption capacity.
The invention also relates to an absorbent article manufactured according
to said method and comprising a substantially liquid impermeable backsheet, a substantially
liquid permeable topsheet and an absorbent core placed between the backsheet and
the topsheet. The absorbent article further comprises lotion. The lotion is in the
shape of a continuous fiberised string and exhibits a storage modulus of at least
0.2 Pa measured at 55°C.
In another embodiment of the invention, the lotion exhibits a storage
modulus of at least 0.6 Pa measured at 55°C. In yet another embodiment of the invention
the lotion exhibits a loss modulus of at least 2.0 Pa measured at 55°C.
It is well within the scope of the invention to use different kinds
of lotion. However, it is important that the storage modulus is at least 0.2 Pa
measured at 55°C.
The lotion composition used in the invention can be chosen from;
5 to 50% by weight of a component melting in the range from 25°C to 37°C, chosen
from the group of paraffins, fatty acid esters, polyhydroxy fatty acid esters, fatty
alcohols, alkoxylated fatty acid esters, alkoxylated fatty alcohols and mixtures
of these compounds and
5 to 50% by weight of a component melting in the range from 40°C to 60°C, chosen
from the group of polyhydroxy fatty acid esters, C14-C22-fatty alcohols, C12-C22-fatty
acids, the alkoxylated derivatives of the fatty alcohols and fatty esters, and mixtures
of these components, and
25% to 45% by weight of water.
In another embodiment of the invention, the lotion is placed on the
topsheet of the absorbent article as a continuous fiberised string.
BRIEF DESCRIPTION OF DRAWINGS:
The invention will be described in greater detail below with reference
to the figures shown in the accompanying drawings, in which:
Fig. 1a and 1b
show a spray head,
Fig. 2
shows a spray gun comprising a spray head,
Fig. 2a,
shows a spray apparatus,
Fig. 3
shows a cross-section of a nozzle when lotion is pushed through the orifice,
Fig. 4
shows several spray guns/modules attached in a side-by-side relationship,
Figs. 5-10
show different spray patterns; and
Fig. 11-12
show temperature sweep graphs.
DETAILED DESCRIPTION:
The invention can be applied to several different kinds of absorbent
articles such as pant diapers, diapers, incontinence devices, sanitary napkins,
pantiliners, micro-sanitary napkins etc.
Figs. 1a and 1b show a spray head 1 for the application of lotion
to an absorbent article. The spray head 1 has a circular cross-section and is provided
with an orifice 2, which also has a circular cross-section. The orifice 2 is centrally
placed on the spray head 1. Separate air stream orifices 3 are symmetrically placed
around the central orifice 2, and are arranged to pass streams of air 4 in specified
directions during use of the spray head.
The directed air streams 4 propel lotion towards the surface of an
absorbent article, forming a fiberised string of lotion 5 in the shape of a helix.
The fiberised string of lotion does not penetrate the topsheet and is prevented
from decreasing the absorption capacity of the absorbent article.
Fig 2 shows a schematic representation of the spray head 1 mounted
in a part of a spray gun 10. The spray gun 10 comprises a cover 11 which comprises
a temporary container 12 for the lotion. In the container 12 there is a temperature
regulator 13 with which the temperature of the lotion can be regulated. From the
temporary container 12, a small pipe 14 connects the central orifice 2 with the
temporary container 12 on the spray head 1.
An air channel 15 supplies air to a chamber 16 arranged within the
cover 11, the chamber 16 being in direct connection with the air stream orifices
3 on the spray head 1. The chamber 16 is provided with an air stream regulator by
which it is possible to regulate the flow of the air streams.
Fig. 2a shows a schematic representation of a spraying apparatus such
as is used in the invention. The apparatus comprises a lotion storage container
20 and a pump 21 for pumping the lotion from the storage container 20 to a spray
head 22, the spray head 22 and the storage pump 21 being connected by a heated hose
23. Pressurised air 24 is supplied to the spray head 22.
Fig. 3 shows a cross-section of a nozzle 30. The nozzle 30 has a centrally
placed orifice 31 and two separated air stream orifices 32, placed close to the
central orifice 31 on either side thereof. Fig. 3 also shows how lotion is pushed
trough the central orifice 31 and is propelled by air streams 35 as it leaves the
central orifice 31.
Fig. 4 shows how several spray guns or modules are placed next to
each other in order to produce a broader pattern of lotion on the sprayed surface.
Spray heads of this type are commercially available for hot-melt adhesive
applications under the trademark Controlled Fiberization Spray Nozzles, manufactured
by Nordson® Corporation, 2905 Pacific Drive, Norcross, Georgia 30071, United
States.
Additional models are also available from Nordson®. The spraying
technique is described further in US 4,785,996, US 4,815,660 and in EP 474,155.
The lotion composition:
The lotion preferably is a composition comprising at least 5 to 50%
by weight of a component a) melting in the range from 25°C to 37°C, chosen from
the group of paraffins, fatty acid esters, polyhydroxy fatty acid esters, fatty
alcohols, alkoxylated fatty acid esters, alkoxylated fatty alcohols and mixtures
of these compounds, and 5 to 50% by weight of a component b) melting in the range
from 40°C to 60°C, chosen from the group of polyhydroxy fatty acid esters, C14-C22-fatty
alcohols, C12-C22-fatty acids, the alkoxylated derivatives
of the fatty alcohols and fatty esters, and mixtures of these components, and c)
25% to 45% by weight of water.
The compositions according to the invention are emulsions or suspensions.
The emulsions are preferably of the O/W or W/O type.
By choosing the composition so that the storage modulus exceeds 0.2
Pa, a continuous fiberised string can be achieved when spraying the lotion.
In addition to specific emulsifiers and selected oily substances,
the emulsions comprise 25-45% by weight, preferably 25-40% by weight and in particular
25-35% by weight, of water. The compositions according to the invention are preferably
in the form of W/O emulsions.
Component a) can be chosen from a large number of compounds known
to the person skilled in the art, the melting point should be in the range from
25°C to at most 37°C. Firstly, for this purpose it is possible to use certain paraffins,
but also fatty acid esters and, in particular, fatty alcohols. Suitable paraffins
are preferably semisolid paraffins, such as soft paraffin, preferably petrolatum.
Suitable fatty alcohols are, for example, dodecanol or ricinol alcohol, to name
one representative of the unsaturated fatty alcohols. The use of glycerides is particularly
suitable, here preferably mixtures of partial glycerides and triglycerides, which
should have the desired melting point of from 25°C to 37°C. Particular preference
is given here to mixtures of glycerides of fatty acids having 8 to 18 carbon atoms.
Glycerides represent mono-, di- and/or triesters of glycerol with
fatty acids, namely, for example, caproic acid, caprylic acid, 2-ethylhexanoic acid,
capric acid, lauric acid, isotridecanoic acid, myristic acid, palmitic acid, palmoleic
acid, stearic acid, isostearic acid, oleic acid, elaidic acid, petroselic acid,
linoleic acid, linolenic acid, elaeostearic acid, arachidic acid, gadoleic acid,
behenic acid and erucic acid, and technical-grade mixtures thereof. They conform
to the formula (I),
in which R is a COR' radical, in which R' is a branched or unbranched, saturated
or unsaturated alkyl radical having 6 to 22 carbon atoms, and/or independently thereof,
is hydrogen. Typical examples are lauric acid monoglyceride, lauric acid diglyceride,
coconut fatty acid monoglyceride, coconut fatty acid triglyceride, palmitic acid
monoglyceride, palmitic acid triglyceride, stearic acid monoglyceride, stearic acid
diglyceride, isostearic acid monoglyceride, isostearic acid diglyceride, oleic acid
monoglyceride, oleic acid diglyceride, tallow fatty acid monoglyceride, tallow fatty
acid diglyceride, behenic acid monoglyceride, behenic acid diglyceride, erucic acid
monoglyceride, erucic acid diglyceride, and technical-grade mixtures thereof, which
may also comprise small amounts of triglyceride as secondary components from the
preparation process.
An essential feature of the lotion is the emulsifier component c).
Particularly suitable are glycerol partial esters with C12-C21
fatty acids, preferably glycerol monolaurate. Further, polyvinyl stearol ether and,
particularly preferably, polyglycerol poly-12-hydroxystearate can be used.
Polyol poly-12-hydroxystearates are known substances which are sold,
for example, under the names Dehymuls, PWPH or Eumulgin VL75 or Dehymuls SP11 by
Cognis Deutschland GmbH. Further details regarding these compounds are given in
European Patent Specification EP 0 766 661.
The polyol component of these compounds can be derived from substances
which have at least 2, preferably 3 to 12 and in particular 3 to 8, hydroxyl groups
and 2 to 12 carbon atoms. Typical examples are glycerol, polyglycerol, alkylene
glycols, such as, for example, ethylene glycol, diethylene glycol and propylene
glycol, methylol compounds, preferably trimethylolethane, trimethylolpropane, trimethylolbutane,
pentaerythritol or dipentaerythritol, alkyl oligoglycosides having 1 to 22, preferably
1 to 8 and in particular 1 to 4, carbon atoms in the alkyl radical, sugar alcohols
having 5 to 12 carbon atoms, for example sorbitol or manitol, and sugars having
5 to 12 carbon atoms, preferably glycose or sucrose, and also amino sugars, for
example glucamine. The reaction product of poly-12-hydroxystearic acid with polyglycerol
has proven particularly advantageous. Here, the polyglycerol has the following composition:
glycerols 5 to 35% by weight, diglycerols 15 to 40% by weight, triglycerols 10 to
35% by weight, tetraglycerols 5 to 20% by weight, pentaglycerols 2 to 10% by weight
and the remainder oligoglycerols.
In addition to the component a) and the component b) and water, the
compositions according to the invention may also comprise further constituents,
in particular further emulsifiers, preferably nonionic emulsifiers. Nonionic emulsifiers
are characterized by their skin friendliness and mildness and their ecotoxicologically
good properties. The use of a combination of nonionic emulsifiers gives particularly
finely divided emulsions, meaning that the stability of the composition is increased.
The composition according to the invention comprises the coemulsifiers in an amount
of from 0 to 15% by weight, preferably from 1% to 10% by weight and in particular
from 3% to 10% by weight, based on the total weight of the composition.
Furthermore, the compositions according to the invention may contain
further conventional ingredients, for example silicone waxes or polysiloxanes, in
amounts of from 1% to 6% by weight, preferably from 1.5% to 5.5% by weight and in
particular from 2% to 5% by weight. Polysiloxanes are known polymeric compounds
which contain the following structure as monomer units:
Here, R" and R"', independently of one another, are hydrogen or an
alkyl, cycloalkyl, aryl or alkenyl radical. Siloxanes of this type preferably have
viscosities at 37°C in the range from 5 to 5000 mPa s.
In addition, and preferably, the lotion may comprise skin-friendly
or skincare substances, in amounts of from 0.1 % to 10% by weight, preferably from
1% to 8% by weight most preferably from 2 to 6% by weight. Ingredients of this type
may, for example, be bisabolol, alantoin and panthenol. It is also possible to use
vitamins, preferably vitamin E and vitamin precursors, and protein hydrolysates.
Also suitable are plant extracts, such as from camomile, aloe vera, lime blossom,
horse chestnut, green tea, oak bark, stinging nettle, hops, burdock, horsetail,
hawthorn, almond, spruce needle, almond wood, juniper, coconut, apricot, lemon,
wheat, kiwi, melon, orange, grapefruit, sage, rosemary, birch, mallow, thyme, balm,
restharrow, coltsfoot, ginseng and root ginger. In addition, however, other skincare
substances may also be present. Those which may be named here are, in particular,
chitosan, and zinc oxide or zinc ricinoleate.
In a particular embodiment, the emulsions may comprise further optional
additives, such as, for example, superfatting agents, thickeners, polymers, waxes,
biogenic active ingredients, deodorant active ingredients, film formers, UV light
protection factors, antioxidants, hydrotropic agents, preservatives, insect repellents,
self-tanning agents, solubilizers, stabilizers, perfume oils, dyes, antimicrobial
agents and the like.
Superfatting agents which can be used are substances such as, for
example, lanolin and lecithin, and polyethoxylated or acylated lanolin and lecithin
derivatives, polyol fatty acid esters, monoglycerides and fatty acid alkanolamides,
the latter also serving as foam stabilizers.
Suitable thickeners are, for example, Aerosil grades (hydrophilic
silicas), polysaccharides, in particular xanthan gum, guar guar, agar agar, alginates
and Tyloses, carboxymethylcellulose and hydroxyethylcellulose, and also relatively
high molecular weight polyethylene glycol mono- and diesters of fatty acids, polyacrylates
(e.g. Carbopols® from Goodrich or Synthalens® from Sigma), polyacrylamides,
polyvinyl alcohol and polyvinylpyrrolidone, surfactants, such as, for example, ethoxylated
fatty acid glycerides, esters of fatty acids with polyols, such as, for example,
pentaerythritol or trimethylolpropane, fatty alcohol ethoxylates with a narrowed
homologue distribution or alkyl oligoglucosides, and electrolytes such as sodium
chloride and ammonium chloride.
Suitable cationic polymers are, for example, cationic cellulose derivatives,
such as, for example, a quaternized hydroxyethylcellulose available under the name
Polymer JR 400® from Amerchol, cationic starch, copolymers of diallylammonium
salts and acrylamides, quaternized vinylpyrrolidone/vinylimidazole polymers, such
as, for example, Luviquat® (BASF), condensation products of polyglycols and
amines, quaternized collagen polypeptides, such as, for example, lauryldimonium
hydroxypropyl hydrolysed collagen (Lamequat®L/Grünau), quaternized wheat polypeptides,
polyethyleneimine, cationic silicone polymers, such as, for example, amidomethicones,
copolymers of adipic acid and dimethylaminohydroxypropyldiethylenetriamine (Cartaretins®/Sandoz),
copolymers of acrylic acid with dimethyldiallylammonium chloride (Merquat® 550/Chemviron),
polyaminopolyamides, cationic chitin derivatives, such as, for example, quaternized
chitosan, optionally in microcrystalline dispersion, condensation products from
dihaloalkyls, such as, for example, dibromobutane with bisdialkylamines, such as,
for example, bis-dimethylamino-1,3-propane, cationic guar gum, such as, for example,
Jaguar® CBS, Jaguar® C-17, Jaguar® C-16 from Celanese, quaternized ammonium
salt polymers, such as, for example, Mirapol® A-15, Mirapol® AD-1, Mirapol®
AZ-1 from Miranol.
Suitable anionic, zwitterionic, amphoteric and nonionic polymers are,
for example, vinyl acetate/crotonic acid copolymers, vinylpyrrolidone/vinyl acrylate
copolymers, vinyl acetate/butyl maleate/isobornyl acrylate copolymers, methyl vinyl
ether/maleic anhydride copolymers and esters thereof, uncrosslinked polyacrylic
acids, polyacrylic acids crosslinked with polyols, acrylamidopropyltrimethylammonium
chloride/acrylate copolymers, octylacrylamide/methyl methacrylate/tert-butylaminoethyl
methacrylate/2-hydroxypropyl methacrylate copolymers, polyvinylpyrrolidone, vinylpyrrolidone/vinyl
acetate copolymers, vinylpyrrolidone/dimethylaminoethyl methacrylate/vinylcaprolactam
terpolymers, and optionally derivatized cellulose ethers and silicones.
Biogenic active ingredients are to be understood as meaning, for example,
tocopherol, tocopherol acetate, tocopherol palmitate, ascorbic acid, deoxyribonucleic
acid, retinol, bisabolol, allantoin, phytantriol, panthenol, α-hydroxycarboxylic
acids, amino acids, ceramides, pseudoceramides, essential oils, plant extracts and
vitamin complexes.
Suitable deodorant active ingredients are, for example, antiperspirants,
such as, for example, aluminium chlorhydrate, aluminium zirconium chlorhydrates,
and zinc salts. These are used for the preparation of antiperspirant and deodorizing
preparations and probably act via the partial closure of the sweat glands by protein
and/or polysaccharide precipitation. In addition to the chlorhydrates, it is also
possible to use aluminiumhydroxylactates and acidic aluminium/zirconium salts. An
aluminium chlorhydrate which corresponds to the formula [Al2(OH)5Cl]·2.5
H2O and whose use is particularly preferred is commercially available
under the tradename Locron® by Clariant GmbH, for example. Likewise preferred
according to the invention is the use of aluminium zirconium tetrachlorohydrex glycine
complexes, which are marketed, for example, by Reheis under the name Rezal®
36G. Further deodorant active ingredients which may be added are esterase inhibitors.
These are preferably trialkyl citrates, such as trimethyl citrate, tripropyl citrate,
triisopropyl citrate, tributyl citrate and, in particular, triethyl citrate (Hydagen®
C.A.T., Cognis Deutschland GmbH). The substances inhibit the enzyme activity, thus
reducing the formation of odour. Presumably, in this process, the cleavage of the
citric ester results in the release of the free acid, which lowers the pH on the
skin sufficiently for the enzymes to be inhibited. Further substances which are
suitable as esterase inhibitors are sterol sulphates or phosphates, such as, for
example, the sulphates and phosphates of lanosterol, cholesterol, campesterol, stigmasterol
and sitosterol, dicarboxylic acids and esters thereof, such as, for example, glutaric
acid, monoethyl glutarate, diethyl glutarate, adipic acid, monoethyl adipate, diethyl
adipate, malonic acid and diethyl malonate, hydroxycarboxylic acids and esters thereof,
such as, for example, citric acid, malic acid, tartaric acid or diethyl tartrate.
Antibacterial active ingredients which influence the bacterial flora and destroy
bacteria which decompose perspiration or inhibit them in their growth can likewise
be present in the emulsions. Examples thereof are chitosan, phenoxyethanol and chlorhexidine
gluconate. 5-Chloro-2-(2,4-dichlorophenoxy)phenol, which is sold under the name
Irgasan® by Ciba-Geigy, Basle/CH, have proven particularly effective.
To improve flow behaviour of the composition, it is also possible
to use hydrotropic agents, such as, for example, ethanol, isopropyl alcohol, or
polyols. Polyols that are suitable here preferably have 2 to 15 carbon atoms and
at least two hydroxyl groups. The polyols can also contain further functional groups,
in particular amino groups, or be modified with nitrogen. The overall fraction of
optional additives may be from 1% to 50% by weight, preferably from 5% to 40% by
weight, based on the compositions.
Furthermore, it may be advantageous to co-use optional components
to stabilise the emulsion, for example glycerol or magnesium sulphate, preferably
in amounts of in each case 0.1 to at most 5% by weight, preferably from 0.1 to 1.5%
by weight.
The composition can be prepared by customary cold or hot processes;
preference is given to using the phase inversion temperature method.
In the following examples the following composition was used:
84
40% by weight of partial glyceride/triglyceride mixture based on C14/C16-fatty
acids, melting range: 33.0°C -35.5°C
15% by weight of partial glyceride/triglyceride mixture based on C14/C16-fatty
acids, melting range 40.0°C -42.0°C
13% by weight of polyvinyl stearyl ether
1.45% by weight of glycerol (86% pure)
0.30% by weight of MgSO4 × 7 H2O
Remainder: water
58
Reference lotion comprising:
50-60% by weight of a mixture of partial glycerides of coconut fatty acids,
melting point 30-34°C
10-20% by weight of stearyl alcohol, melting point 56-60°C
20% by weight of polyvinyl stearyl ether, melting point 45-48°C
2% by weight of silicone wax.
Results from Figs. 5-10, spray tests when spraying with equipment
shown in fig. 2a with two different lotions at different temperatures.
Hot melt adhesive equipment (such as described in fig. 2a) parameters when spraying
with lotion 58:
ModuleNordson, five modules (two blocked)Spray head3 Nordson Nr. 755957-&phis;12 (0,012) -12 air jets-SPCContainerNordson with pump pr6m1.Temp (sample5)Container: 55°C, tube: 55°C, nozzle: 55°CTemp (sample 6)Container: 60°C, tube: 60°C, nozzle: 60°CTemp (sample 7)Container: 60°C, tube: 65°C, nozzle: 70°CSpeed80m/minSpray air pressure0.4barDistance spray head/material15mm
Hot melt adhesive equipment (such as described in fig. 2a) parameters when spraying
with lotion 84:
ModuleNordson, five modules (two blocked)Spray head3 Nordson Nr. 755957-&phis;12 (0,012) -12 air jets-SPCContainerNordson with pump pr6m1.Temp (sample 8)Container: 55°C, tube: 55°C, nozzle: 55°CTemp (sample 10)Container: 60°C, tube: 60°C, nozzle: 60°CTempContainer: 65°C, tube: 68°C, nozzle: 75°CSpeed80m/minSpray air pressure0.4barDistance spray head/material15mm
Anspruch[en]
Method for applying lotion (5) to a surface of an absorbent article, said method
comprising the steps of;
placing the surface of the absorbent article in the proximity of a spraying
apparatus comprising a spray head (1) having an orifice (2),
pushing the lotion (5) through the spray head orifice (2),
characterised in that
the lotion (5) is propelled to the surface as a continuous fiberised string.
Method according to claim 1, characterised in that the surface of the
absorbent article is placed at a distance of from 15 to 300 mm from the spray head
(1).
Method according to claim 1, characterised in that the lotion is propelled
from the orifice by an air stream (4) which is separated from the orifice (2).
Method according to claim 1, characterised in that the lotion (5) is
delivered with a velocity of at least 80 m/min.
Method according to claim 1, characterised in that the lotion (5) is
propelled to the surface as a spiral-shaped continuous fiberised string.
Method according to claim 1, characterised in that the fiberised string
has a diameter of less than 2.2 mm.
Absorbent article comprising a substantially liquid impermeable back sheet,
a substantially liquid permeable topsheet and an absorbent core placed between the
back sheet and the topsheet, characterised in that a surface of the absorbent
article is provided with lotion which has been applied with the method according
to claim 1.
Absorbent article according to claim 7, characterised in that the lotion
exhibits a storage modulus of at least 0.2 Pa measured at 55°C.
Absorbent article according to claim 8, characterised in that the lotion
exhibits a storage modulus of at least 0.6 Pa measured at 55°C.
Absorbent article according to claim 8, characterised in that the lotion
exhibits a loss modulus of at least 2.0 Pa measured at 55°C.
Absorbent article according to claim 7, characterised in that the lotion
composition is chosen from:
a) 5% to 50% by weight of a component melting in the range from 25°C to 37°C,
chosen from the group of paraffins, fatty acid esters, polyhydroxy fatty acid esters,
fatty alcohols, alkoxylated fatty acid esters, alkoxylated fatty alcohols and mixtures
of these compounds; and
b) 5% to 50% by weight of a component melting in the range from 40 to 60°C,
chosen from the group of polyhydroxy fatty acid esters, C14-C22-fatty alcohols,
C12-C22-fatty acids, the alkoxylated derivatives of the fatty alcohols and fatty
esters, and mixtures of these components; and
c) 25% to 45% by weight of water.
Absorbent article according to claim 7, characterised in that the lotion
is placed on the topsheet in a continuous fiberised string.
Absorbent article according to claim 7, characterised in that the diameter
of the fiberised string is less than 2.2 mm.