Note: Descriptions are shown in the official language in which they were submitted.
~~~.~'~'~
_ 1 _
FIELD OF THE INVENTION
The present invention relates to a method for
making decorative inlaids of the type that includes chips
of resinous porous material.
More particularly, the present invention
relates to a method for making such inlaids which are
used as floor or wall coverings.
BACK(aROUND OF THE INVENTION
Various methods are known for embedding chips
into a clear plastisol in order to make decorative inlaid
patterns.
United States patent No. 4, 440, 826 issued April
3, 1984 to Armstrong World Industries, Inc describes
translucent or transparent chips, having a thickness
dimension not less than the thickness of the layer of
material, applied to the surface thereof; the material is
warmed and the structure is consolidated to push the
chips down into the layer of material until they contact
the underlying surface.
United States patent No. 4,212,691 issued July
15, 1980 to Congoleum Corporation describes a method for
making decorative inlaid types of resilient sheet
materials by spreading the chips onto the wet plastisol
layer as a full coverage; the excess of chips are then
~ ~:1~~~,.>
_ 2 _
removed and the remaining chips are pressed into the
plastisol using calender devices.
United States patent No. 4,794,020 issued
December 27, 1988 to Tarkett Inc. describes a process for
making sheet vinyl covering materials by first depositing
resinous particles on a wet unqelled layer o.f PVc
plastisol or organosol, removing the excess and then
passing the sheet between a heated, cylindrical surface
and a means for gradually and uniformally increasing 'the
contact pressure between the cylindrical surface and the
coated surface of the sheet.
In the methods of the prior art, especially
with the inlaids described in the Congoleum patent, it is
not possible to evenly distribute the particles on the
surface. less than full coverage. It is therefore
difficult, in some instances, to see the printed design
which usually is defined on the inlaid; further, each
chip does not appear as a single particle. In the case
of the inlaids of the Tarkett patent, air is entrapped in
the resinous porous particles during the embedding step.
It has been found that some products on the
market are stiff; in other cases, they are difficult to
fold in corners and at the perimeter thereby making them
difficult to install.
- 3 -
OBJECTS AND STATEMENT OF THE INVENTION
It is an object of the present invention to
provide an improved process for the making of decorative
inlaid types of sheet material which comprises forming,
on a sheet of flexible substrate, a plastic layer of
plastisol or organosol containing resinous porous
particles. In order to provide a higher bond of the
particles with the plastisol and a superior continuous
layer, the coating containing the chips is deaerated
under vacuum. All PVC dry blends are porous and
intrinsically contain air. When the particles are
embedded in the plastisol, the air is entrapped.
Subsequently, when heating to fuse the product, the air
will expand because the matrix reduces its viscosity and
a foamy particle which has poor contact with the
transparent matrix, is formed. Foamy particles in an
inlaid results in a reduction of wear resistance
properties and of appearance retention.
An additional feature of using a vaccumed chip
and plastisol mixture is to create a positive pressure
from the plastisol onto the particles, which pressure
will prevent the pigments coated on the particles to
migrate to the plastisol.
Another object,of the present invention is to
provide a method wherein the PVC dry blend chips are
added into the clear plastisol which has previously been
deaerated under vacuum, in a mixer equipped with a mass
P
~~.~1'
- 4 -
agitator. In order to prevent the pigments from
migrating from the dry blend particles to the plastisol,
which could lead to a lack of medium clarity, the mixture
is blended by slow agitation, under vacuum. This
provides a better chip appearance without obscuring the
under layer appearance.
The method of the present invention results in
a three dimensionnal appearance and broadens the styling
or designing spectrum.
In one form of the invention, a plurality of
variously colored resinous particles axe mixed in
accordance with an intented appearance to the final
product while a wet ungelled plastisol or organosol is
prepared; then a predetermined amount of the mixture of
colored particles is deposited in the plastisol; then,
the mixture is blended by slow agitation under vacuum.
The mixture is then placed on a sheet of
flexible substrate which has a coating of plastisol, the
coating bearing a printed design.
In one preferred form of the invention, the
blended mixture, prior to being applied on the substrate
is filtered to prevent passage of unwanted material,
including mass agglomeration.
~ o7 n. ~ '!'~ .',%
~,, f t:;
~.A~~L. eJ ~'f .~-3
- 5 -
In a further form of the invention, once the
blended mixture is gelled in an oven, it is smoothened by
being passed between rotatable cylinders of a calender
machine.
In a further form of the invention, the
cylinders are cooled to increase the fixing of the
particles.
OTHER OB~'ECTS AND STATEMENT OF THE INVENTION
Other objects and further scope of
applicability of the present invention will become
apparent from the detailed description given hereinafter.
It should be understood, however, that this detailed
description, while indicating preferred embodiments of
the invention, is given by way of illustration only,
since various changes and modifications within the spirit
and scope of the invention will become apparent to those
skilled in the art.
IN THE DRAWINGS
Figure 1 is a flow sheet diagram representing
a typical process for making inlaids in accordance with
the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to figure 1, it can be seen that
various steps are prepared separately.
~~n y;,gr!'~
ri G b
- 6 -
A wet plastic layer is applied to a substrate.
The various materials which can be used for the
construction of a substrate or for a substrate layer are
well known to these skilled in the art of manufacture of
floor or wall covering products. It is not deemed
necessary to review all these various materials, some of
which are found described, for example, in the above-
mentionned U.S. patent 4,794,020.
Since this application makes numerous
references to the term "plastisol°', it will only be
mentionned that it is a relatively high molecular weight
polyvinyl chloride (PVC) resin dispersed in one or more
plastisizers. For purpose of the present invention,
plastisol compositions are intended to include also
organosolp it should be mentionned, however, that
organosol contains one or more volatile liquids that are
driven off upon heating.
Referring to the block diagram of figure 1, a
wet plastic application step 10 is followed by a
gellation step 12 which is then followed, if desired, by
a printing step 14. The application, gellation and
printing steps are well known in the art and may be found
described in detail in U.S. patent Nos. 3,293,108 and
4,017,658.
r. i~ .a. a z7
The present invention is particularly concerned
with coating the gelled plastic layer bearing a printed
design with a wet mix of particles and plastisol.
This wet mix has been prepared by blending
particles of resinous material with the plastisol in a
mass agitator by slow agitation under vacuum, step 16.
The mixture of the particles with the plastisol results
from two separate steps which consist: (20) mixing a
plurality of variously colored particles and (22)
preparing a clear plastisol which is deaerated under
vacuum.
Before the application of the wet mix to the
printed surface at (16), the mixture may optionnaly be
filtered at (24) to a mesh size greater than that of
particles to avoid agglomeration and contamination.
After step 16, the product is gelled in an oven
at a temperature which is lower than the temperature used
at step 12. This is followed by a smoothening operation
28 which consists in smoothening the surface of the
product by passing the product between the pressure rolls
of a calender device. Preferably, the rolls are cooled,
so that the temperature is lower than the temperature of
the product being processed. The cylindrical surface of
the rolls may have a flat surface or a textured surface
depending on the finish. to be given to the product.
r.-, ,~ ~'e :; 3
~~ ~.~_:~ ~-j
_8_
The product which exits from the calender may
be subject to various optionnal steps, one of which is to
cover the product with a layer of plastic material. This
is followed by a gellation step which provides the entire
fusing of 'the product and the obtention of a three-
dimensionnal effect. Then, this is followed by a cooling
process and the product is thus obtained.
The following examples are intended to
demonstrate preferred embodiments of this invention
without limitating the scope thereof. In the following
examples all parts percentages are by weight.
EXAMPLE 1
A floor covering substrate sheet of
conventional non-asbestos felt approximately 25 mils
thick is coated with 30 mils of non-foamable coloured
plastisol base coat. The composition is as follows:
PARTS BY WEIGHT
PVC Emulsion resin K value: 70 (Pevikon* 11F) 60
PVC Extender resin RV: 2.25 (Oxy* 567) 40
Di (2 ethyl hexyl) phthlate 105
Di Iso Decyl Phthlate 4.5
Expoxidized soy bean oil 5
Calcium carbonate 304
Viscosity reducing agent BYK* 4010 17
* trade mark
_ g _
Titanium dioxide 23
Barium zinc type stabilizer (Irgastab* BZ512) 2
Mineral Spirit 11.5
The coated substrate is then gelled in a hot
oven at 135°C for 2 minutes. The surface is 'then printed
on a multihead gravure press using vinyl inks produced by
Domco Industries Limited.
After printing a plastisol-chip mixture about
28 mils thick is applied using a knife over roll coater.
Approximately 935 gm/mz are applied at a viscosity of
3300 cps - spindle 4 - 20 RPM25°C.
The composition of the clear plastisol is:
PARTS BY WEIGHT
PVC dispersion resin: relative viscosity:
2.30 (Oxy* 68 HC) 97
PVC extender resin: relative viscosity:
2.25 (Oxy*.567) 3
Phosphate esther Reofos* 50 of Ciba Geigy 5.5
Monoisobutyrate Monobenzoate Ester
(Dluoplaz* 1046 - Hiils Chemicals) 32
Texanol Isobutyrate (TXIB) 10
Butyl Benzyl Phthlate 13
Stabilizer, Barium - zinc type (Synpron* 1363)
The composition of the dry blend chips is:
* trade mark
r; rx
3° a ' ~.~
,,~ . c. roi t~'t s
- 10 -
PARTS BY WEIGHT
Suspension grade PVC resin (relative
viscosity 2.4) (Vygen* 300XL) 100
Di (2 ethyl hexyl) Phthlate 27
Butyl Benzyl Phthlate 27
Stabilizer - Barium - Zinc (Irgastab* BZ 512) 2.7
Titanium Dioxide 15.9
Coloured pigments - pastes 3.1
Purchased coloured pastes from Pan Chemicals,
Hawthorne, N.J., are white, brown iron oxide, yellow,
orange and red, dispersed in di (2 ethyl hexyl
phthalate).
The Vygen* 300XL resin is a larger than normal
suspension resin. It is round and the particle size
average is 415 micron (approximately 35 mesh). Screen
analysis is as follows:
MESH o RETAINED
20 (833 micron) .85
28 (569 micron) .75
35 (416 micron) 65.63
50 (294 micron) 28.58
Pan 50 mesh 4.19
* trade mark
i' 2 'J
'? :.
-- 11 -
Once the vacuumed and plastisol-chip mixture
has been applied onto the printed gelled structure, it is
then heated in a hot air circulating oven for 3 minutes.
The temperature profile is 204, 230, 230°C per successive
zone. At the exit from the oven, the top surface of the
hot sheet is given a further infra red heat treatment to
allow the material to be embossed mechanically with a
specific design. The floor covering product thereby
produced displays ~a relief structure (mechanical
embossing) . The decorative inlaid product has an average
thickness of about 80 mils and exhibits excellent wear
and design characteristics.
E7iAbIPLE 2
A floor covering substrate sheet of standard
type non-asbestos felt approximately 30 mils thick is
coated with 10 mils of a foamable plastisol the
composition of which is as follow:
PARTS BY WEIGHT
PVC dispersion resin K value:67 (Oxy* X25) 70
PVC extender resin relative visc. 2.25
(Oxy* 567) 30
Butyl Benzyl Phthlate 35
Di (2 ethyl hexyl) Phthlate g
Texanol Isobutyrate (TXIB) 12
Titanium Dioxide 5.5
* trade mark
I
- 12 -
Snowhite* #9 (calcium carbonate) 11.0
Antimony Trioxide 5.5
Azo Dicarbonamide 3.4
Zinc oxide 1.0
Mineral spirit 3.0
Brookfield HBT* - viscosity 2800
CPS - spindle 4 - 20 rpm - 25C
The coated substrate is then gelled in a hot
air circulating oven at 140°C for 2 minutes. The surface
is then printed on a multihead gravure press using vinyl
inks prepared by Domco Industries Limited. The ink used
to print the valley area of the (registered and non-
registered embossing) pattern contains additionally 15
parts of trimellitic anhydride (TMA) to suppress in
specific areas the decomposition of the foamable
plastisol.
After printing, the vacuumed chip - plastisol
mixture is applied 22 mils thick using a knife over roll
coater. A total of 770 gm/mz of chip - plastisol mixture
is coated of which 13% is a blend of white, blue, tan and
black dry blend chips. The blend is prepared in the
following ratio white, tan, blue and black 92.5 /4 /3
/0.5.
* trade mark
- 13 -
The composition of the clear plastisol is:
PARTS BY WEIGHT
PVC dispe*sion resin: relative viscosity:
2.30 (Oxy 68 HC) g7
PVC extender resin: relative viscosity:
2.25 (Oxy* 567) 3
Phosphate esther Reofos* 50 (Ciba Geigy) 5.5
Monoisobutyrate Monobenzoate Ester
(Nuoplaz* 1046 - Hiils Chemicals) 32
Texanol Isobutyrate TXIB 10
Butyl Benzyl Phthlate 13
Stabilizer, Barium - zinc type (Synpron* 1363) 3
The composition of the dry blend chips is:
PARTS BY WEIGHT-COLOURED
Suspension grade PVC resin (relative
viscosity 2.4) (Vygen* 300XL) 100
Di (2 ethyl hexyl) Phthlate 27
Butyl Benzyl Phthlate 27
Stabilizer - Barium - Zinc (Irgastab* BZ 512) 2.7
Titanium Dioxide 15.9
Coloured pigments - pastes 3.1
Purchased coloured pastes from Pan Chemicals,
Hawthorne, N.J., are white, brown iron oxide, yellow,
* trade mark
~ r~ 5~ s ~'3
- 14 -
orange and red, dispersed in di (2 ethyl hexyl
phthalate).
The floor covering product thereby produced
displays a relief structure (embossing) in register with
the printed areas. To protect the surface even further
another protective coating of 1 mil dry of water base
polyurethane is supplied and has the following
composition:
PARTS BY WEIGHT
Water base polyurethane coating -
Permuthane coating 35& solid 100
Flattening agent 2.5
Antifoaming agent (BYK* chemical) .125
Viscosity Zahn: cup #2 - 21 seconds
The wet 3 mils of polyurethane coating is
applied on the embossed product using an air knife.
It is then dried and cured in a hot air
circulating oven for 2 minutes. The temperature profile
is 121/204/204°C in successive zones.
The floor covering product thereby produced
exhibits excellent wear and design characteristics.
* trade mark
T A PJ
.. ~ s,~ ~ ~ ~~ f :~
-- 15 -
Although the invention has been described above
with respect with one specific form, it will be evident
to a person skilled in the art that it may be modified
and refined in various ways. It is therefore wished to
have it understood that the present invention should not
be limited in scope, except by the terms of the following
claims.
