Note: Descriptions are shown in the official language in which they were submitted.
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FLOOR CLEANING PADS AND PREPARATION THEREOF
FIELD OF THE INVENTION
This invention relates to floor cleaning pads used to clean hard surface
floors, such as,
wood, vinyl, stone etc. and to their preparation. In particular the invention
relates to
reversible floor cleaning pads for use on floor cleaning machines designed to
rotate at
speeds less than 1200 revolutions per minute.
BACKGROUND TO THE INVENTION
Lofty, open, non-woven three-dimensional abrasive articles are known for use
in cleaning
and polishing floors and other surfaces. Examples of such non-woven surface
treating
articles are non-woven pads made according to the teaching of US-A-2,958,593,
3,537,121, 4,437,271, 4,893,439, 5,030,496, 5,282,900, 5,458,962 and
6,261,164.
Examples of such abrasive products are commercially available under the
registered trade
mark "Scotch-Brite" from 3M United Kingdom plc.
The pads of this type are typically cut in a circular shape to be used in
conjunction with a
floor polishing machine. Typical sizes range from 8" (203mm) to 28" (711 mm)
in
diameter. The pads may also be rectangular or of other shapes depending upon
the
equipment with which they are to be used. Such machines have a means for
engaging or
holding a pad thereon while rotating the pad against the surface being
treated.
The pads are available in any of a wide variety of types to provide many
functions. Some
pads are extremely abrasive and are desirably used for wax stripping and
cleaning floor
surfaces which are heavily encrusted with soil. Other are mildly abrasive and
are typically
used for floor polishing, with or without the prior application of wax. The
different
abrasive properties of the pads are achieved by appropriate selection of the
fibres, resin
binders and abrasive materials used in their construction.
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In order to assist the operators in the correct selection and identification
of a floor pad to
perform a particular task, the floor pads are made in distinctive colours,
each colour being
associated with a particular product specification. For example, Scotch-Brite
floor pads
that are currently commercially available in the United Kingdom include the
following:
Scotch-Brite Black Floor Pad - for wet stripping
Scotch-Brite Brown Floor Pad - for wet or dry stripping
Scotch-Brite Green Floor Pad - for wet scrubbing
Scotch-Brite Blue Floor Pad - for general cleaning
Scotch-Brite Red Floor Pad - for spray cleaning
Scotch-Brite White Floor Pad - for dry polishing
There are occasions when an operator of a floor cleaning machine may need to
use two
different pads. For example, the operator may be dry polishing a floor e.g. in
a
supermarket, office etc., when he finds an area of the floor which has been
soiled and
requires cleaning prior to polishing. He must either clean the area manually
or change the
pad on the machine to a pad suitable for cleaning. Since the pads are large,
spare pads are
not carried on the floor cleaning machine and it is necessary for the operator
to acquire an
appropriate pad from a store or the like which may be some distance from the
working
area.
US 4,536,911 and Re 32978 disclose a reversible hard floor cleaning pad for
use with
super high speed and ultra high speed machines. The pad includes a first
porous non-
woven air-layered web having an upper, floor cleaning surface and an opposite
lower
surface. The upper cleaning surface is adapted to clean hard surface floors,
such as wood
or vinyl, when placed on the floor and rotated by a flooring machine about a
vertical axis
passing through the centre of the first web at super high speeds of at least
1000 revolutions
per minute. A second porous non-woven air-layered web having a lower, floor
cleaning
surface and an opposite upper surface is disposed parallel to and spaced from
the first web
with the first web lower surface facing the second web upper surface. The
second web
lower cleaning surface is also adapted to clean hard surface floors when
placed on the floor
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and rotated at super high speeds. A flexible wet-laid non-woven strata layer
having
uniform directional strength and an upper layer surface and an opposite lower
layer surface
is positioned between the first and second webs. The first web lower surface
is glued
directly to the upper layer surface and the second web upper surface directly
to the lower
layer surface with an elastomer, resin-reinforced non-flammable adhesive. A
multi-layer
reversible pad is thereby formed having generally uniform strength in all
horizontal
directions thereby eliminating any tearing and shredding problem.
The upper and lower layers may be formed differently. For example one may be
formed of
natural fibres and the other of syntlletic fibres. Also the resins used to
iinpregnate one
layer can include abrasive so that layers can be used for cleaning and the
other for high
speed buffing.
The manufacturing process for the reversible cleaning pads is complex,
involving the
preparation of two separate webs and equipment to laminate the two webs
together
sandwiching separate strata layers therebetween.
US-A-4078340 discloses a low density abrasive pad having a mildly abrasive
surface and a
more aggressively abrasive surface, thus being especially suited for cleaning
and scouring
kitchen utensils, said mildly abrasive surface being capable of cleaning but
not harmfully
scratching non-stick plastic pan coatings and other plastic surfaces, said
more aggressively
abrasive surface being capable of scouring soiled pots and pans, said pad
having a void
volume of about 85% to 97% and consisting essentially of in combination:
a lofty, non-woven mat, having a thickness of at least about 1.3cm when
incorporated in said pad and extremely high void volume, consisting
essentially of
criinped mixed denier nylon, polyester, or mixtures of both nylon and
polyester
filaments at least 2.5cm in length when fully extended, said mixed denier
filaments
consisting essentially of small diameter filaments on the order of 10 to 20
denier
and larger diameter filaments on the order of 40 to 70 denier wherein the
weight
ratio of large diameter filaments to small diameter filaments is in the range
of 1: 3
to about 3 : 1,
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said fibres being bonded togetlier at points where they cross and contact each
other
with a soapy water-resistant tough thermoset first resin binder which contains
a
finely divided soft abrasive material having a Mohs hardness on the order of 3
to 7
and a particle size on the order of 180 grade or finer, and
coated over one entire major surface of said pad and penetrating into said pad
to a
depth on the order of 1 to 7mm, a soapy water-resistant tough second resin
binder
which contains finely divided hard abrasive material having a Mohs hardness in
excess of 8 and a particle size on the order of 280 grade or finer.
The size of the pad is convenient to fit the user's hand. For example,
circular discs should
not be larger than 15cm in diameter nor should rectangular shapes be larger
than 15cm in
length or width.
SUMMARY OF THE INVENTION
The present invention provides a simple, effective construction of reversible
abrasive pads
for use on a rotary cleaning machine, such as a floor cleaning machine, and a
process for
their production. The invention is also concerned with the provision of
reversible abrasive
pads that enable the efficiency of a surface-cleaning operation, particularly
a floor cleaning
operation, to be increased.
According to the present invention there is provided an abrasive article for
use on a rotary
cleaniiig machine having, on one side, a first abrasive face having a first
abrasive nature
and, on the other side, a second abrasive face having a second abrasive nature
different
from the first; each abrasive face comprising a lofty, three-dimensional, non-
woven web of
fibres bound together, at the places where they contact, by a binder material;
wherein each
abrasive face is provided with a visual indicator to inform the user of its
abrasive nature.
In an abrasive article in accordance with the invention, the abrasive nature
of an abrasive
face may be determined by one or more of several factors, for example the
fibres used in
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the non-woven web; the presence of abrasive particles, and the nature
(including the size)
of those abrasive particles when present; the nature of the binder material;
and the
presence of additives (for example materials such as short fibres, or friction
modifiers) in
the binder material. Accordingly, the abrasive nature of one abrasive face of
the abrasive
article can be made to differ from the abrasive nature of the other face by
adjusting one or
more of those factors.
According to one embodiment of the present invention there is provided a floor
cleaning
pad for use on a rotary floor cleaning machine comprising a circular pad
having a diameter
of at least 200mm and a thickness of at least 10mm having an upper cleaning
face and a
lower cleaning face, the pad comprising a lofty, three-dimensional non-woven
web of
fibres bound together at places where they contact by a first binder
containing a colouring
material of a first colour and, coated over one of said upper and lower
cleaning faces and
penetrating to a depth of from 1 to 7mm, a second binder containing a
colouring material
of a second colour which contrasts with said first colour, the pad being free
of a middle
flexible, wet-laid non-woven strata layer having uniform directional strength
in all
longitudinal directions.
According to a further aspect of the present invention there is provided a
method of
making a floor cleaning pad for use on a rotary floor cleaning machine
comprising:
providing a lofty, three-dimensional, non-woven web of fibres having a
thickness
of at least 10inm and comprising upper and lower major faces,
impregnating said web with a first tllermosetting binder containing a
colouring
material of a first colour to bond the fibres together at places where they
contact,
coating one of said upper and lower major faces with a second thermosetting
binder containing a colouring material of a second colour which contrasts with
said
first colour, such that said second binder penetrates to a depth of from 1 to
7mm
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and imparts to that one face an abrasive nature that is different from the
abrasive
nature of the other face,
heating said binder resins at a temperature and for a sufficient time to form
infusible insoluble cured products thereof, and
cutting the resulting web into circular pads having a diameter of at least
200mm.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows one embodiment of a floor cleaning pad in accordance with the
invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
By way of example only, abrasive articles in accordance with the invention
will be
described with reference to the accompanying drawing which is a perspective
view of a
floor cleaning pad.
The invention provides abrasive articles, such as the reversible floor
cleaning pad 1 shown
in the drawing, having two cleaning faces with different abrasive natures,
typically
different aggressiveness. In the drawing, only the upper cleaning face 2 of
the pad is
visible. Thus, the cleaning pad 1 is capable of conducting two different
operations
depending on the side in use. One cleaning face has a visual indicator, e.g.
indicia or a
colour which contrasts with a visual indicator on the other cleaning face
thereby allowing
the operators to clearly identify the correct cleaning surface to be used. The
visual
indicators may conveniently be the colour of the abrasive faces. The cleaning
pads may
conveniently have cleaning faces having the same colour and same
aggressiveness as the
currently commercially available products with identical aggressiveness and
same colour
on each side.
The floor cleaning pads 1 may be made by slight modification to the existing
processes for
preparing floor cleaning pads and do not require the lamination of two
separate webs to
middle strata layer having uniform directional strength in all longitudinal
directions.
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Currently floor pads are made by forming a web of fibres and roll coating the
web by
passing it through a pair of rollers wetted by a slurry of finely divided
abrasive particles in
a coloured binder formulation. The selection of binder, abrasive and colour
depend upon
the intended aggressiveness of the product and, in some cases, the abrasive
particles may
not be required.. After roll coating the web is cured in an oven. The fibres
of the web are
bonded to each other at the contact points.
Tn some cases, particularly pads used for buffing, the resulting web is simply
cut to fomi
the pads. In other cases the web is subject to additional treatment by
impregnating each
surface with a slurry of finely divided abrasive in a coloured binder
formulation.
The binder and abrasive used for this treatment may be different from that
used in the roll
coating. Generally the additional treatment is applied by spray coating one
surface with
the slurry to not only cover the surface but allow penetration of the slurry
to impregnate
several millimetres of the web. The treated web is then cured in an oven and
the treatment
repeated on the second surface. Thereafter the cured web is cut into circular
pads.
In accordance with the invention pads which would not have been subject to the
second
treatment stage are treated by applying to one surface a slurry of finely-
divided abrasive in
a binder formulation having a colour contrasting with that of the binder
present in the web
in a manner which allow penetration of the slurry to a depth of 1 to 7min. The
abrasive
used is more aggressive than any already present in the web. The impregnated
web is
cured and cut into circular pads. The resulting pad 1 has a less aggressive
cleaning face of
one colour and a more aggressive cleaning face (for example, the face 1) in a
contrasting
colour (not indicated in the drawing).
In the case of pads which are currently made by a process having the two stage
treatment,
one surface is treated with a slurry of abrasive in a binder formulation that
will typically
have the same colour as the binder present in the web. However, the second
surface is
treated with a different slurry of abrasive in a binder formulation having a
contrasting
colour in a manner allowing penetration of the slurry in the web to a depth of
1 to 7mm.
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The abrasive is more aggressive than that present in the web and other
cleaning surface.
The web is cured and cut into circular pads. The resulting pad has a less
aggressive
cleaning face of one colour and a more aggressive cleaning face (for example,
the face 1)
in a contrasting colour (not indicated in the drawing).
An alternative process for making floor pads 1, or other abrasive articles in
accordance
with the invention, comprises forming two lofty three-dimensional, non-woven
webs of
fibres bound together at places where they contact by a binder material. Each
web has an
abrasive face on at least one side, the said abrasive face of one web having a
first abrasive
nature, the said abrasive face of the other web having a second abrasive
nature different
from the first, and each of the said abrasive faces being provided with a
visual indicator of
its abrasive nature. The webs are laminated together on their other sides, for
example by a
hot-melt adhesive, to form a composite web having the said abrasive faces as
its outer
faces, from which abrasive articles are cut. In that case, the junction
between the two webs
may be visible on the edge of the abrasive article, as indicated by the broken
line 3 on the
floor pad shown in the drawing.
In that alternative process, each of the original webs from which the
composite web is
formed may be made by forming a web of fibres and roll coating the web by
passing it
through a pair of rollers wetted by a slurry of finely divided abrasive
particles in a coloured
binder formulation. The selection of binder, abrasive and colour depend upon
the intended
aggressiveness of the product and, in some cases, the abrasive particles may
not be
required. After roll coating the web is cured in an oven. In some cases, at
least one of the
webs is subject to additional treatment by impregnating at least one face with
a slurry of
finely divided abrasive in a coloured binder formulation.
The floor pad 1 may optionally be provided with a pre-cut central portion 4,
indicated in
broken lines in the drawing. This central portion can be removed by the user
to provide a
central aperture in the pad, if required, depending on the type of floor
cleaning machine on
which the pad is to be used.
The open, lofty, non-woven webs used in the present invention are preferably
made from
crimped, staple, thermoplastic organic fibres such as polyamide and polyester
fibres.
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Although crimping is not necessary to the invention, crimped, staple fibres
can be
processed and entangled into non-woven webs by conventional web forming
machines
such as that sold under the trade name RANDO WEBBER which is commercially
available from the Curlator Corporation. Methods useful for making non-woven
webs
suitable for use in the invention from crimped, staple synthetic fibres are
disclosed in US-
A-2,958,593 and 3,537,121 wliich are incorporated herein by reference.
Continuous
crimped or uncrimped fibres may also be used, but these tend to increase
frictional drag or
the article.
The staple fibres may be stuffer-box crimped, helically crimped as described,
for example,
in US-A-4,893,439, or a combination of both, and the non-woven webs useful in
making
non-woven surface treating articles of the invention may optionally contain up
to about 50
weight percent melt-bondable fibres, more preferably from about 20 to about 30
weight
percent, to help stabilise the non-woven web and facilitate the application of
the coating
resin.
Suitable staple fibres known in the art are typically made of polyester or
polyamide,
although it is also known to use other fibres such as rayon.
Melt bondable fibres useful in the present invention can be made of
polypropylene or other
low-melting polymers such as polyesters as long as the temperature at which
the melt
bondable fibres melt and thus adhere to the other fibres in the non-woven web
construction
is lower than the temperature at which the staple fibres or melt bondable
fibres degrade in
physical properties. Suitable and preferable melt bondable fibres include
those described
in US-A-5,082,720, mentioned above. Melt bondable fibres suitable for use in
this
invention must be activatable at elevated temperatures below temperatures
which would
adversely affect the helically crimped fibres. Additionally, these fibres are
preferably co-
processable with the helically crimped fibres to form a lofty, open unbonded
non-woven
web using conventional web forming equipment. Typically, melt bondable fibres
have a
concentric core and a sheath, have been stuffer box crimped with about 6 to
about 12
crimps per 25mm, and have a cut staple length of about 25 to about 100mm.
Composite
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fibres have a tenacity of about 2 to 3g/denier. Alternatively, melt bondable
fibres may be
of a side by side construction or of eccentric core and sheath construction.
Preferred fibres for use in this invention are helically crimped polyester
staple fibres and
stuffer box crimped polyester staple fibres, particularly helically criinped
polyethylene
terephthalate (ET) staple fibres and stuffer box crimped PET staple fibres.
US-A-3,595,738 incorporated herein by reference, discloses methods for the
manufacture
of helically crimped bicomponent polyester fibres suitable for use in this
invention. The
fibres produced by the method of that patent have a reversing helical crimp.
Fibres having
a reversing helical crimp are preferred over fibres that are crimped in a
coiled
configuration like a coiled spring. However, both types of helically crimped
fibres are
suitable for this invention. US-A-3,868,749, 3,619,874 and 2,931,089 all of
which are
incorporated herein by reference, disclose various methods of edge criinping
synthetic
organic fibres to produce helically crimped fibres.
Helically crimped fibres typically and preferably have from about 1 to about
15 full cycle
crimps per 25mm fibre length, while stuffer box crimped fibres have about 3 to
about 15
full cycle crimps per 25mm fibre length. As taugllt in the '439 patent, when
helically
crimped fibres are used in conjunction with stuffer box criniped fibres,
preferably the
helically crimped fibres have fewer crimps per specified length than the
stuffer box fibres.
Crimp index, a measure of fibre elasticity, preferably ranges from about 35 to
about 70
percent for helically crimped fibres, which is about the same as stuffer box
crimped fibres.
Crimp index can be determined by measuring fibre length with appropriate "high
load"
attached, then subtracting fibre length with appropriate "low load" attached,
and then
dividing the result value by the high load fibre length and multiplying that
value by 100.
(The values of the appropriate "high load" and "low load" depend on the fibre
denier. For
fibres of the invention having 50 100 denier, low load is about 0.1 to 0.2
grams, high load
is about 5 to 10 grams.) The crimp index can also be determined after exposing
the test
fibres to an elevated teinperature, e.g. 135 C to 175 C for 5 to 15 minutes,
and this value
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compared with the index before heat exposure. Crimp index measured after the
fibre is
exposed for 5 to 15 minutes to an elevated temperature, e.g. 135 C to 175 C,
should not
significantly change from that measured before the heat exposure. The load can
be applied
either horizontally or vertically.
The lengtll of the fibres employed is dependent upon the limitation of the
processing
equipment upon which the non-woven open web is formed. However, depending on
types
of equipment, fibres of different lengths, or combinations thereof, very
likely can be
utilised in forming the lofty open webs of the desired ultimate
characteristics specified
herein. Fibre lengths suitable for helically crimped fibres preferably range
from about
60mm to about 150inm whereas suitable fibre lengths for stuffer box fibres
range from
about 20 to about 70mm, generally 20 to 40mm.
The thickness (denier) of the fibres used in the non-woven surface treating
articles of the
present invention is not critical. As is generally known in the non-woven
field, larger
denier fibres are preferred for more abrasive articles, smaller denier fibres
are preferred for
less abrasive articles, and fibre size must be suitable for lofty, open, low
density abrasive
products. The denier of fibres typically used for non-woven abrasive articles
of the
invention may range broadly from about 6 to about 800, preferably from 15 to
about 200
denier, more preferably from abut 50 to about 100 denier. Finer deniers than
about 15 may
result undesirable frictional drag when the non-woven surface treating
articles of the
invention are attached to conventional floor machines (i.e. one designed to
rotate and force
the abrasive article against the surface and thus finish the surface). Fibre
deniers larger
than about 200 may reduce drag, but torque from the floor machine may twist
the web
rather than rotate the web as is desired.
Natural fibres may. also be employed, preferably in combination with synthetic
fibres.
Vegetable fibres such as hemp, jute and the like may be used and animal hair
fibres may be
employed. One preferred animal hair fibre is hog's hair fibre. If natural
fibres are
employed, they preferably and typically range from about 0 to about 30 weight
percent of
the total weight of fibres.
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Uncoated fibrous webs useful in the invention typically and preferably have a
weight
ranging from about 300 to about 1000 grams/meter2 ("gsm"), more preferably
ranging
from about 300 to about 600 gsm. The binder coating weight on the fibrous web
is
generally about 1.0 to about 4.0 times the weight of the uncoated web, more
preferably
from about 1.0 to about 3.0 times the weight of the uncoated web.
The non-woven surface floor cleaning pads 1 in accordance with the invention
may be
attached to and used with conventional floor cleaning and buffing machines,
such as those
known under the trade designations. Nilfisk Advance 421 A or Nilfisk Advance
UB 624,
commercially available from Nilfisk-Advance A/S, Sognevej 25, Brondby,
Denmark; or
TASKI ergodisc oinni or TASKI ergodisc 400, commercially available from
3ohnsonDiversey France, 94133 Fontenay-sous-Bois Cedex, France. For efficient
operation using these types of machines, the non-woven cleaning pads 1 in
accordance
with the invention preferably have a non-compressed thickness of at least
1.0cm, more
preferably ranging from about 2cm to about 4cm. As mentioned above, the
thickness is
dependent upon the fibre denier chosen for the particular application. If the
fibre denier is
too fine, the non-woven surface treating articles of the invention will be
less lofty and
open, and thus thinner, resulting in the article tending to be more easily
loaded with floor
finish and/or detritus from the floor or surface being treated.
Binders suitable for use in the non-woven floor cleaning pads 1 in accordance
with the
invention may comprise any thermoplastic or thermoset resin suitable for
manufacture of
non-woven articles, but it will be clear to those skilled in the art of such
manufacture that
the resin in its final, cured state must be compatible (or capable of being
rendered
compatible) with the fibres of choice.
The cured resin preferably adheres to all of the types of fibres in a
particular non-woven
article of the invention, thus deterring (preferably preventing) the
subsequently made non-
woven surface treating article from becoming prematurely worn during use. In
addition,
cured resins suitable for use in the invention preferably adhere to the
abrasive particles so
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as to prevent the particles from prematurely loosening from the non-woven
surface treating
articles of the invention during use, but should allow the presentation of new
abrasive
particles to the surface being treated.
Another consideration is that the cured resin should be soft enough to allow
the non-
woven surface treating articles of the invention to be somewhat flexible
during use as a
polishing or crystallisation pad so as to allow the pad to conform to
irregularities in the
floor. However, the cured resin should not be so soft as to cause undue
frictional drag
between the non-woven surface treating articles of the invention and the floor
being
treated. In the case of the articles of the invention being attached to a
conventional electric
floor polishing machine, high frictional drag may lead to increased amperage
draw on the
part of the floor machine and may cause electrical fuses to "blow" or circuit
breakers to
"trip".
Suitable resins will not readily undergo unwanted reactions, will be stable
over a wide pH
and humidity ranges, and will resist moderate oxidation and reductions. The
cured resins
should be stable at higher temperatures and have a relatively long shelf life.
The resins of the binders suitable for use in the non-woven surface treating
articles of the
invention may comprise a wide variety of resins, including synthetic polymers
such as
styrene-butadiene (SBR) copolymers, carboxylated-SBR copolymers, melamine
resins,
phenol-aldehyde resins, polyesters, polyamides, polyureas, polyvinylidene
chloride,
polyvinyl chloride, acrylic acid-methylmethacrylate copolymers, acetal
copolymers,
polyurethanes and mixtures and cross-linked versions thereof.
One preferred group of resins useful in the present invention, particularly if
a substantial
number of the fibres of the non-woven web are polyester, are terpolymeric
latex resins
formed by linear or branched copolymerisation of a mixture of a non-
functionalised
monoethylenically unsaturated co-monomer, a functionalised monoethylenically
unsaturated co-monomer, and a non-functionalised diethylenically unsaturated
co-
monomer. ("Functionalised", as used herein, means a monomer having a reactive
moiety
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such as -OH, NH2 COOH, and the like, wherein "non-functionalised" means a
monomer
lacking such a reactive moiety.
Particularly preferred terpolymer latex resins, used when the fibres of the
non-woven web
are substantially polyester, are formed by random or block terpolymerisation
of styrene,
butadiene, and a functionalised monoethylenically unsaturated monomer selected
from the
group consisting of monomers having the general formula R1R2-C=CR3COOH and
anhydrides thereof, wherein Rl and RZ are independently selected from H and
CH3 and R3
is selected from H, CH3 and COOH. In commercially available resins of this
type, the
1o amount of functionalised monoethylenically unsaturated monomer is typically
proprietary,
but is believed to be about 1 to about 10 mole percent of the total monomer.
The mole
percent of styrene ranges from about 50 percent to about 80 percent, more
preferably from
about 60 to about 70 percent, particularly preferably about 65 percent, as
mole percentage
of styrene and butadiene.
One commercially available and particularly preferred terpolymer latex resin
is that sold
under the trade name "AMSCO RES 5900", from Unocal. This aqueous latex resin
is a
terpolymer of styrene/butadiene/functionalised monoethylenically unsaturated
monomer
having styrene/butadiene mole ratio of 65135, 1 to 10 mole percent of
functionalised
monoethylenically unsaturated monomer, solids weight percent of 50, pH of 9.0,
anionic
particle charge, particle size of 0.2 micrometer, and glass transition
teinperature of -5 C.
Higher butadiene mole ratios produce a softer resin, but at the cost of
greater drag.
Typically and preferred coatable binder precursor solutions containing this
latex resin and
abrasive particles which are useful in forming cured binders are presented in
Table A (wet
parts by weight).
The above described terpolymers may be used uncross-linked, but they are
preferably
cross-linked by the reaction of the reactive COOH moiety with a
polyfunctionalised
monomer, such as a phenolic or melamine resin, as indicated in Table A.
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Cross-linking resins, as mentioned in Table A, below, maybe used to improve
the water
and solvent resistance of the ultimate non-woven surface treating articles of
the invention,
and to increase their firmness. Melamine-fonnaldehyde resins, such as the
fully
methylated melamine-formaldehyde resins having low free methyl content sold
under the
trade designations "Cymel 301", 1133 and 1168, "Cymel 303" and "Aerotex M-3"
(all
currently available from American Cyanamid Company) and the like, are
suitable. The
former provides slightly higher tensile strength while the latter enhances
stiffn.ess and
resilience of the non-woven. Phenolic resins have also been used as cross-
linking resins,
such as those sold under the trade designations "433" (Monsanto) and "R-7"
(Carborundum), and the like.
The latex resins useful in the present invention, if cross-linked, will have
greater than 10%
crosslinking, usually having in the range from about 15% to 80% cross-linking,
more
usually having in the range from about 25% to 60% cross-linking, and typically
being in
the range from about 45% to 55% cross-linking. The cross-linked latex resin
particles may
act as organic fillers, helping to smooth the coating of the fibres of the non-
woven webs
with the linear or branched copolymers.
TABLE A
Preferred Binder Precursor Solutions
Ingredient Broad weight % Range Preferred weight % Range
SBR latex (50% solids) 20 to 40 25 to 35
water 2 to 10 2 to 6
melamine-formaldehyde/ 1 to 10 1 to 5
crosslinking resin
abrasive 10 to 65 40 to 60
catalyst (40% sol. of
diammoniunl phosphate)
antifoam agent 0.01 to 0.05 0.01 to 0.03
surfactant 0.1 to 1.0 0.1 to 0.5
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The calculated or theoretical percentage of cross-linking is defined as the
weight of
polyfunctionalised monomer (or monomers) divided by the total weight of
monomers.
Non-functionalised monoethylenically unsaturated monomers generally suitable
for
preparing linear, branched, and cross-linked latex resins useful herein
include, styrene,
ethylvinylbenzene, and vinyltoluene, with styrene being particularly
preferred.
Diethylenically unsaturated monomers useful in the invention include
isopropene,
butadiene and chloroprene, with butadiene being particularly preferred.
If the non-woven abrasive articles comprise a substantial amount of polyamide
(e.g. nylon
6,6) fibres, otller resins may be preferred as the resin component of the
binder. Examples
of suitable binders for use when the fibres comprise polyamides include
phenolic resins,
aminoplast resins, urethane resins, urea-aldehyde resins, isocyanurate resins,
and mixtures
thereof. One preferred resin is a thermally curable resole phenolic resin,
such as described
in Kirk-Othmer, Encyclopaedia of Chemical Technology, 3rd Ed., John Wiley &
Sons,
1981, N.Y., Vol. 17, p. 384-399, incorporated by reference herein.
Examples of commercially available phenolic resins include those known by the
trade
names "VARCUM" and "DUREZ" (from Occidental Cheinicals Corp., N. Tonawanda,
NY) and "AROFENE" (from Ashland Chemical Co.). The resole phenolic resin of
choice
has about 1.7 : 1 forinaldehyde to phenol weight ratio, 76 weight percent
solids.
Other suitable binder systems are disclosed in US-A-5,030,496.
Useful abrasive particles may range in size anywhere from about 24 grade,
average particle
diameter of about 0.71mm to about 1000 grade, average particle diameter of
about
0.01mm. Depending upon the desired application, the abrasive materials used in
the
article of the invention may be a soft abrasive, a hard abrasive or a mixture
thereof. Soft
abrasives, having a Mohs hardness in the range of from about 1 to 7, provide
the article
with a mildly abrasive surface. Examples of useful soft abrasives include such
inorganic
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materials as garnet, flint, silica, pumice and calcium carbonate; and such
organic
polymeric materials as polyester, polyvinyl chloride, methacrylate,
methylmethacrylate,
polymethylmethacrylate, polycarbonate and polystyrene. Hard abrasives, those
having a
Mohs hardness greater than about 8, provide the article with a more aggressive
abrasive
surface. Examples of useful hard abrasives include such materials as silicon
carbide,
corundum, aluminum oxide, topaz, fused alumina-zirconia, boron nitride,
tungsten carbide
and silicon nitride.
The invention will be illustrated by the following Examples.
Exam les
The Examples are based on and compared with the commercially available Scotch-
Brite@
product:
White Floor Pad
Red Floor Pad
Blue Floor Pad
Brown Floor Pad
Green Floor Pad
Black Floor Pad
The White, Red, Blue and Brown floor pads comprise a web of polyester fibres.
The
Green and Black floor pads comprise a web of nylon fibres. Each of these
commercial
products are manufactured by impregnating the web with a slurry by roll or
spray coating
and curing in an oven. The coat formulations for each product are as follows:
White Floor Pad : SBR latex binder + talc mineral
Red Floor Pad : SBR latex binder + silica mineral + red pigment dispersion
Blue Floor Pad : SBR latex binder + aluminium oxide (fine size) mineral + blue
pigment
dispersion
Brown Floor Pad : SBR latex + aluminium oxide (fine size) + brown piginent
dispersion
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Green Floor Pad : phenolic binder + calcium carbonate filler +
silica/aluminium oxide
(fine size) mix of minerals + green pigment dispersion
Black Floor Pad : phenolic binder + aluminium oxide (medium size) + black
pigment
dispersion.
The following reversible floor pads in accordance with the invention were
prepared:
White/Red
White/Blue
Red/Blue
Blue/Brown
Green/Black
White/Red
A White floor pad was prepared as described above and one surface coated with
the Red
floor pad coating formulation followed by curing in an oven.
White/Blue
A White floor pad was prepared as described above and one surface coated with
the Blue
floor pad coating formulation followed by curing in an oven.
Red/Blue
A Red floor pad was prepared as described above with the exception that the
coating of the
second surface was conducted using the Blue floor pad coating formulation in
place of the
Red floor pad coating formulation.
Blue/Brown
A Blue floor pad was prepared as described above with the exception that the
coating of
the second surface was conducted using the Brown floor pad coating formulation
in place
of the Blue floor pad coating formulation.
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Green/Black
A Green floor pad was prepared as described above and one surface coated with
the Black
floor pad coating formulation followed by curing in an oven.
The properties of the floor pad of the invention were measured and compared
with the
commercial products.
Abrasive Power
The abrasive power was measured by the Schiefer Cut Test method.
This test is a modified version of ASTM Method D 4158-82 for determining the
relative
aggressiveness or the ability to retain cut in use of Scotch-BriteTM materials
or similar
abrasive materials. Testing produces uniform abrasion in every aziinuthal
direction, not
only planar or circular. The pressure used in this test represents the average
force that a
slow speed rotary floor machine puts on a floor pad. Testing procedure
involves a 1021nm
acrylic plastic disc under the abrasive material at a controlled pressure and
rotation per
minute (rpm) for 5,000 revolutions in a controlled wet environment.
Aggressiveness is
measured by the amount of weight (in g) removed from the plastic disc.
Side 1 Side 2
White floor pad 0 0
Red floor pad 0.1 0.1
Blue floor pad 1 1
Green floor pad 1.2 1.2
Brown floor pad 2.3 2.3
Black floor pad 3.2 3.2
White/Red 0 0.1
White/Blue 0 1
Red/Blue 0.1 1
Blue/Brown 1 2.3
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[~reenlBlack 1.2 3.2
It will be seen that the Red, Blue, Brown and Black surfaces of the floor pad
of the
invention behave in the same manner as their counterpart commercial products.
Tensile Stren tg_h
Satnples 51mm (2 inches) wide and 150mm long were cut and tested on a Lhomargt
dynamometer at a speed of 305mm per minute. The average of six measurements
was
recorded.
Sample N/2 inches Sample N/2 inches
White 35 White/Red 35
Red 37 Red/Blue 37
Blue 37 Blue/Brown 37
Green 38 Green/Black 38
Performance Tests
a) Shine at buffing
A floor tile was coated with a floor finish. It was dulled with an abrasive
hand pad and
the gloss is measured with a gloss meter.
The pad under investigation was mounted on a polishing machine rotating at 400
RPM.
The pad was run onto the tile with a fixed number of passes, generally six and
twelve
passes.
White and White/Red on the White side performed equally.
Red and Red/Blue on the Red side performed equally.
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b) Shine at sRray buffings
A floor tile was coated with a floor finish. It was dulled with an abrasive
hand pad and the
gloss measured with a gloss meter.
The pad under investigation was mounted on a polishing machine rotating at 400
RPM. A
few sprays of a commercially available "spray buff cleaner and polish" liquid
were sprayed
onto the tile. The pad was run six times over the tile and the gloss measured.
A few sprays of "spray buff cleaner and polish" were again applied onto the
tile and the
pad run over the tile for six more passes. The gloss was again measured.
Red and White/Red on the Red side performed equally.
Blue and Red/Blue on the Blue side performed equally.
Blue and Blue/Brown on the Blue side performed equally.
d) Cleanin~
A black mark was applied onto a floor tile. One coat of floor finish was
applied onto the
mark. The pad under investigation was mounted on a polishing machine rotating
at 150
RPM. The number of passes required to remove the coat of floor finish and the
marlc, in
wet conditions was measured.
Red and Red/Blue on the Blue side performed equally.
Blue and Blue/Brown on the Blue side performed equally.
Green and Green/Black on the Green side performed equally.
Stripping or heavy duty cleaning
A black mark was applied onto a floor tile. Three coats of floor finish were
applied onto
the mark. The pad under investigation was mounted on a polishing machine
rotating at
150 RPM. The number of passes required to remove the coats of floor finish and
the
mark, in wet conditions, was measured.
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Brown and Blue/Brown on the Brown side performed equally.
Green and Green/Black on the Black side performed equally.
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