U.S. patent number RE33,069 [Application Number 07/096,348] was granted by the patent office on 1989-09-26 for process for obtaining areas of distinctive appearance on synthetic coverings and the product derived therefrom.
This patent grant is currently assigned to Eurofloor S.A.. Invention is credited to Jean-Francois Courtoy, Daniel Marchal.
United States Patent |
RE33,069 |
Courtoy , et al. |
September 26, 1989 |
Process for obtaining areas of distinctive appearance on synthetic
coverings and the product derived therefrom
Abstract
A process and product is presented for obtaining selective areas
of distinctive appearance, i.e., matting on synthetic coverings.
The process includes, depositing a polymeric coating which contains
at least one radiation initiator for polymerization onto at least a
first selected area or zone on an expandable or non-expandable
support substrate. Next, at least one second coating comprised of a
crosslinkable monomer is deposited onto a second selected area on
the substrate. This second area or zone may encompass at least a
portion of the first area. Thereafter, pre-gelling is performed on
the deposited material followed by a graining operation which is
carried out over at least a portion of the substrate surface. The
synthetic covering in the first zone or area is then polymerized by
radiation initiation wherein the particular appearance thereof is
fixed to the substrate. Thereafter, gelling is carried out wherein
the polymer which has not been fixed by radiation initiation will
flow, i.e., fluidize, such that the grained appearance in the
second area or zone will disappear, i.e., smooth over. This gelling
may also cause some expansion of the polymer on the substrate.
Inventors: |
Courtoy; Jean-Francois (Wiltz,
LU), Marchal; Daniel (Esch sur Alzette,
LU) |
Assignee: |
Eurofloor S.A.
(LU)
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Family
ID: |
26640298 |
Appl.
No.: |
07/096,348 |
Filed: |
September 11, 1987 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
603842 |
Apr 25, 1984 |
04617222 |
Oct 14, 1986 |
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Foreign Application Priority Data
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Apr 25, 1983 [LU] |
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84766 |
Aug 11, 1983 [LU] |
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84957 |
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Current U.S.
Class: |
428/142; 427/511;
427/519 |
Current CPC
Class: |
B44C
1/205 (20130101); D06N 7/0013 (20130101); D06N
7/0028 (20130101); D06N 7/0023 (20130101); Y10T
428/24364 (20150115) |
Current International
Class: |
B44C
1/00 (20060101); D06N 7/00 (20060101); B44C
1/20 (20060101); B05D 003/06 () |
Field of
Search: |
;427/43.1,44,53.1,54.1,261,262,264 ;428/141,142,152 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1061259 |
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Nov 1953 |
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FR |
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1538506 |
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Jul 1968 |
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FR |
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2235796 |
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Jan 1975 |
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FR |
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1159685 |
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Jul 1969 |
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GB |
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Primary Examiner: Morganstern; Norman
Assistant Examiner: Padgett; Marianne L.
Attorney, Agent or Firm: Fishman, Dionne & Cantor
Claims
What is claimed is:
1. A process of obtaining areas of distinctive appearance on a
synthetic covering, the covering including a support layer,
including the steps of:
depositing at least a first polymeric coating having at least one
radiation initiator therein onto a first selected .[.area.].
.Iadd.zone .Iaddend.of said support layer;
depositing at least a second .[.polymeric.]. coating onto a second
selected .[.area.]. .Iadd.zone .Iaddend.of said support layer, at
least a portion of said second .[.polymeric.]. coating comprising a
crosslinkable monomer.Iadd., said deposited coatings defining a
synthetic covering.Iaddend.;
pre-gelling said .[.deposited coatings.]. .Iadd.synthetic
covering.Iaddend.;
mechanically graining .Iadd.at least .Iaddend.selected areas of
said .[.deposited coatings.]. .Iadd.synthetic covering .Iaddend.to
form a matted surface;
polymerizing said .[.first polymeric coating.]. .Iadd.synthetic
covering in said first zone .Iaddend.via said radiation initiator
wherein said .[.first polymeric coating.]. .Iadd.synthetic covering
in said first zone .Iaddend.is fixed to said support layer, and
wherein said matted surface on said .[.first polymeric coating.].
.Iadd.synthetic covering in said first zone .Iaddend.is fixed
thereon; and
gelling .[.said second polymeric coating.]. to cause fluidization
of said .[.second polymeric coating.]. .Iadd.synthetic covering
which has not been fixed by initiation in said first zone
.Iaddend.thereby smoothing said matted surface thereon.
2. The process of claim 1 wherein said support layer is
non-expandable.
3. The process of claim 1 wherein said support layer is
expandable.
4. The process of claim 3 including:
expanding said support layer during gelling.
5. The process of claim 1 including:
depositing said second polymeric coating over at least a portion of
said first polymeric coating.
6. The process of claim 1 wherein:
said radiation initiator is an ultraviolet polymerization
initiator.
7. The process of claim .[.6.]. .Iadd.1 .Iaddend.wherein:
said .[.ultraviolet initiator is in the form of.]. .Iadd.first
coating comprises .Iaddend.an ink or an extender.
8. The process of claim 6 wherein said ultraviolet initiator is at
least one of the initiators selected from the group consisting
of:
benzophenone, 2-chloro-thioxanthone, 2-methyl-thioxanthone,
2-isopropyl-thioxanthone, benzoin, 4,4'-dimethoxybenzoin, benzoin
ethyl ether, benzoin isopropyl ether, benzyldimethylketal,
1,1,1-trichloro-acetophenone,
1-phenyl-1,2-propanedione-2-(ethoxycarbonyl)-oxime,
diethoxyacetophenone, dibenzosuberone, DAROCUR.RTM.1398,
(1-(3,4-dimethylbutyl)-2-hydroxy-2-methyl-propan-1-on),
DAROCUR.RTM.1174,
(1-(4-chlorobutyl)-2-hydroxy-2-methyl-propan-1-on),
DAROCUR.RTM.1020
(1-(4-tertiobutyl)-2-hydroxy-2-methyl-propan-1-on),
DAROCUR.RTM.1116
(1-(4-isopropylphenyl)-2-hydroxy-2-methyl-propan-1-on) and
DAROCUR.RTM.1173 (2-hydroxy-2-methyl-1-phenyl-propan-1-on).
9. The process of claim 7 wherein:
said ink or extender comprises between about 1 to about 50 weight
percent of ultraviolet initiator.
10. The process of claim 1 wherein:
at least one of said first and second polymeric coatings is
provided with an expansion inhibitor.
11. The process of claim 10 wherein:
said expansion inhibitor is trimellitic anhydride.
12. The process of claim 1 wherein:
said crosslinkable monomer is a monomer having at least two
propagation sites.
13. The process of claim 12 wherein said crosslinkable monomer is
at least one of the monomers selected from the group consisting
of:
ethylene glycol dimethacrylate, ethylene glycol diacrylate,
diethylene glycol dimethacrylate, diethylene glycol diacrylate,
triethylene glycol dimethacrylate, triethylene glycol diacrylate,
tetraethylene glycol dimethacrylate, tetraethylene diacrylate,
polyethylene glycol dimethacrylate, polyethylene glycol diacrylate,
1,3-butylene glycol dimethacrylate, 1,4-butylene glycol
dimethacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol
diacrylate, 1,6-hexanediol dimethacrylate, 1,6-hexanediol
diacrylate, neopentyl glycol diacrylate, neopentyl glycol
dimethacrylate, (ethoxylated) bis-phenol A dimethacrylate,
divinylbenzene, divinyltoluene, trimethylolpropane trimethacrylate,
trimethylolpropane triacrylate, pentaerythritol triacrylate,
glyceryl trimethacrylate, pentaerythritol tetracrylate and
pentaerythritol tetramethacrylate.
14. The process of claim 12 wherein:
said crosslinkable monomer also includes monomer compounds having
one propagation site.
15. The process of claim 1 wherein:
said second coating comprises between about 2 to about 50 weight
percent of crosslinkable monomer.
16. The process of claim 1 including:
depositing plastisol in accordance with a silk-screen printing
process to obtain relief.
17. The process of claim 7 including:
depositing said ink or extender via a technique selected from the
group consisting of photogravure, silk screen and flexographic
printing.
18. The process of claim 1 wherein:
said pre-gelling is carried out at a temperature of between about
100 to 160 degrees centigrade.
19. The process of claim 1 wherein:
said graining is carried out at a temperature of about 100 degrees
centigrade and a pressure depending upon the amount of mattness to
be effected.
20. The process of claim 4 wherein:
said expansion is carried out at about 200 degrees centigrade for
between about one minute to about two minutes, 30 seconds.
21. The process of claim 1 wherein:
said pre-gelling and graining stages are carried out simultaneously
using a heated graining roller.
22. The process of claim 1 including:
heating said synthetic covering via infrared radiation.
23. The process of claim 1 including:
enhancing said fluidization by use of a mechanical treatment.
24. The process of claim 23 wherein said mechanical treatment is
selected from the group consisting of a smooth roller and a
textured roller.
25. The process of claim 1 wherein:
at least two radiation initiators are utilized in the same or
different polymeric coatings.
26. The process of claim 25 including:
triggering each radiation initiator via a physiochemical effect
specific to each of said radiation initiators either directly or
via a radiation energy transfer agent.
27. The process of claim 25 wherein:
the polymerization initiation energy provided by radiation in said
first coating does not initiate polymerization in said other
coatings.
28. The process of claim 26 wherein:
said radiation initiator is triggered by a physiochemical effect
selected from the group consisting of X-rays, electron beam and
gamma radiation.
29. The process of claim 26 wherein:
said radiation energy transfer agent triggers said radiation
initiator in a hot oven.
30. The process of claim 1 wherein:
at least a portion of said support layer comprises a plastisol.
31. The process of claim 1 including:
depositing a transparent plastisol coating over said first and
second polymeric coatings to act as a wear layer.
32. The synthetic covering derived from a process of obtaining
areas of distinctive appearance on a synthetic covering, the
covering including a support layer, including the steps of:
depositing at least a first polymeric coating having at least one
radiation initiator therein onto a first selected .[.area.].
.Iadd.zone .Iaddend.of said support layer;
depositing at least a second .[.polymeric.]. coating onto a second
selected .[.area.]. .Iadd.zone .Iaddend.of said support layer, at
least a portion of said second .[.polymeric.]. coating comprising a
crosslinkable monomer.Iadd., said deposited coatings defining a
synthetic covering.Iaddend.;
pre-gelling said .function.deposited coatings.]. .Iadd.synthetic
covering.Iaddend.;
mechanically graining .Iadd.at least .Iaddend.selected areas of
said .[.deposited coatings.]. .Iadd.synthetic covering .Iaddend.to
form a matted surface;
polymerizing said .[.first polymeric coating.]. .Iadd.synthetic
covering in said first zone .Iaddend.via said radiation initiator
wherein said .[.first polymeric coating.]. .Iadd.synthetic covering
in said first zone .Iaddend.is fixed to said support layer, and
wherein said matted surface on said .[.first polymeric coating.].
.Iadd.synthetic covering .Iaddend.is fixed thereon; and
gelling .[.said second polymeric coating.]. to cause fluidization
of said .[.second polymeric coating.]. .Iadd.synthetic covering
which has not been fixed by initiation in said first zone
.Iaddend.thereby smoothing said matted surface thereon.
33. The process of claim 1 including:
providing at least one radiation initiator to said second polymeric
coating.
34. The process of claim 33 including:
triggering each radiation initiator in said polymeric coatings via
a physiochemical effect specific to each of said radiation
initiators either directly or via a radiation energy transfer
agent.
35. The process of claim 33 wherein:
the polymerization initiation energy provided by radiation in said
first coating does not initiate polymerization in said other
coatings.
36. The process of claim 34 wherein:
said radiation initiators are triggered by a physiochemical effect
selected from the group consisting of X-rays, electron beam and
gamma radiation.
37. The process of claim 35 wherein:
said radiation initiators are of the same type. .Iadd.
38. A process of obtaining areas of distinctive appearance on a
synthetic covering, the covering including a support layer,
including the steps of:
depositing at least a first polymeric coating having at least one
radiation initiator therein onto a first selected zone of said
support layer;
depositing at least a second coating onto a second selected zone of
said support layer, said second zone covering at least a portion of
said first zone, at least a portion of said second coating
including a crosslinkable monomer, said deposited coatings defining
a synthetic covering;
pre-gelling said synthetic covering;
mechanically graining at least selected areas of said synthetic
covering to form a matted surface;
polymerizing said synthetic covering in said first zone via said
radiation initiator wherein said synthetic covering in said first
zone is fixed to said support layer, and wherein said matted
surface on said synthetic covering is fixed thereon; and
gelling to cause fluidization of said synthetic covering which has
not been fixed by initiation in said first zone thereby smoothing
said matted surface thereon..Iaddend. .Iadd.
39. The synthetic covering derived from a process of obtaining
areas of distinctive appearance on a synthetic covering, the
covering including a support layer, including the steps of:
depositing at least a first polymeric coating having at least one
radiation initiator thereon onto a first selected zone of said
support layer;
depositing at least a second coating onto a second selected zone of
said support layer, said second zone covering at least a portion of
said first zone, at least a portion of said second coating
including a crosslinkable monomer, said deposited coatings defining
a synthetic covering;
pre-gelling said synthetic covering;
mechanically graining at least selected areas of said synthetic
covering to form a matted surface;
polymerizing said synthetic covering in said first zone via said
radiation initiator wherein said synthetic covering in said first
zone is fixed to said support layer, and wherein said matted
surface on said synthetic covering is fixed thereon; and
gelling to cause fluidization of said synthetic covering which has
not been fixed by initiation in said first zone thereby smoothing
said matted surface thereon..Iaddend. .Iadd.
40. A process of obtaining areas of distinctive appearance on a
synthetic covering, the covering including a support layer,
including the steps of:
depositing at least a first coating having at least one radiation
initiator therein onto a first selected zone of said support layer,
said first coating comprising an ink or extender;
depositing at least a second coating onto a second selected zone of
said support layer, at least a portion of said second coating
including a crosslinkable monomer, said deposited coatings defining
a synthetic covering;
pre-gelling said synthetic covering;
mechanically graining at least selected areas of said synthetic
covering to form a matted surface;
polymerizing said synthetic covering in said first zone via said
radiation initiator wherein said synthetic covering in said first
zone is fixed to said support layer, and wherein said matted
surface on said synthetic covering is fixed thereon; and
gelling to cause fluidization of said synthetic covering which has
not been fixed by initiation in said first zone thereby smoothing
said matted surface thereon..Iaddend. .Iadd.
41. The synthetic covering derived from a process of obtaining
areas of distinctive appearance on a synthetic covering, the
covering including a support layer, including the steps of:
depositing at least a first coating having at least one radiation
initiator therein onto a first selected zone of said support layer,
said first coating comprising an ink or extender;
depositing at least a second coating onto a second selected zone of
said support layer, at least a portion of said second coating
including a crosslinkable monomer, said deposited coatings defining
a synthetic covering;
pre-gelling said synthetic covering;
mechanically graining at least selected areas of said synthetic
covering to form a matted surface;
polymerizing said synthetic covering in said first zone via said
radiation initiator wherein said synthetic covering in said first
zone is fixed to said support layer, and wherein said matted
surface on said synthetic covering is fixed thereon; and
gelling to cause fluidization of said synthetic covering which has
not been fixed by initiation in said first zone thereby smoothing
said matted surface thereon..Iaddend.
Description
This application is a reissue of 06/603,842 filed Apr. 25, 1984 now
U.S. Pat. No. 4,617,222. .Iaddend.
BACKGROUND OF THE INVENTION
This invention relates to the field of synthetic coverings. More
particularly, this invention relates to a process for manufacturing
synthetic coverings and the products obtained thereby. The process
of the present invention is particularly well suited for providing
selected areas of distinctive appearance, i.e., matting or
graining, on a synthetic covering surface, particularly floor or
wall coverings which are based on synthetic materials, usually
polyvinyl chloride (PVC). The present invention is related to U.S.
patent application Ser. No. 603,843,756 filed on the same day as
this application, assigned to the assignee hereof and incorporated
herein by reference.
The majority of synthetic plastic coverings do not exhibit a
sufficient visual difference between glossy areas and matted or
grained areas on the surface thereof. A distinct difference between
gloss and mattness is desirable on synthetic coverings in order to
provide certain distinctive appearances. For example, certain areas
on the surface covering may have a design applied by printing or
other means, while other areas may have a joint imitation thereon.
This is particularly true when a synthetic covering is intended to
imitate a ceramic tile flooring. Accordingly, an important feature
for many types of synthetic coverings is that selected areas or
zones on the surface thereof have a distinctive visual appearance,
especially between glossy areas and matted areas.
In U.S. Pat. No. 4,273,819, matting of the joint between the tiles
of a ceramic tile imitation is provided by the addition of a vinyl
monomer and a thermal initiator to the entire surface layer
followed by hot graining of this surface. The decorative printed
areas contain a catalyst which lowers the decomposition temperature
of the thermal initiator so that those areas retain a matted
(grained) appearance. Conversely, other zones not containing this
catalyst will lose their grained appearance during subsequent
gelling. The process of U.S. Pat. No. 4,273,819 has certain
disadvantages. For example, the process is highly dependent on the
graining temperature. Thus, if the temperature is only slightly
higher than required, there is a danger of initiating a
crosslinking reaction over the entire surface of the synthetic
covering and, thereby, achieving an undesirable matted appearance
over the entire surface thereof. Conversely, too low a graining
temperature will not provide the desired matted appearance even on
those portions where the matted appearance is desired, i.e., at the
joints. Moreover, in view of the kinetics of the decomposition of
the initiator, too long a graining time, even at the correct
temperature, presents the same danger as when using too high a
graining temperature, i.e., complete graining or matting.
Another prior art technique which is similar to that process
described in U.S. Pat. No. 4,273,819 and which also makes it
possible to obtain distinctive matted and glossy surface effects is
described in FR-A-2,531,009. As in the U.S. Patent, the French
Patent suffers from similar deficiencies and drawbacks.
SUMMARY OF THE INVENTION
The above-discussed and other problems of the prior art are
overcome or alleviated by the process and product of the present
invention. In accordance with the present invention, a novel
process is provided for obtaining selective areas or zones of
distinctive appearance, i.e., matting or graining on a synthetic
covering surface which is not dependent on either the graining or
gelling temperatures and which is independent of the graining
reaction time.
In accordance with the present invention, this improved process
includes, depositing a polymeric coating which contains at least
one radiation initiator for polymerization onto at least a first
selected area or zone on an expandable or non-expandable support
substrate. Next, at least one second coating comprised of a
crosslinkable monomer is deposited onto a second selected area on
the substrate. This second area or zone may encompass at least a
portion of the first area. Thereafter, pre-gelling is performed on
the deposited material followed by a graining operation which is
carried out over at least a portion of the substrate surface. The
synthetic covering in the first zone or area is then polymerized by
radiation initiation wherein the particular appearance thereof is
fixed to the substrate. Thereafter, gelling is carried out wherein
the polymer which has not been fixed by radiation initiation will
flow, i.e., fluidize such that the grained appearance in the second
area or zone will disappear, i.e., smooth over. This gelling may
also cause some expansion of the polymer on the substrate.
It should be appreciated that "radiation initiator" may be any
suitable initiator which is decomposed or modified by energy
radiation, for example, by ultraviolet rays, to form free radicals
or ions which are required for chain propogation in a
polymerization reaction.
In a preferred embodiment of the present invention, an ink or
extender containing an ultraviolet polymerization initiator is
deposited on an expandable or non-expandable substrate in at least
the first zone described above. This preferred embodiment makes it
possible to initiate polymerization at localized or selected areas.
In other words, the polymerization reaction can be localized to
those areas where the ultraviolet initiator has been deposited,
this reaction taking place after graining so as to rigidify the
surface of the first zone and retain the matted (grained)
appearance of this surface during subsequent operations.
An important feature of the process and product of the present
invention is that the entire surface of the synthetic covering may
be grained without necessitating a special graining roller
controlled in accordance with the design or decoration of the
covering to be utilized. This is because the zone which is not
polymerized after graining will be fluidized during the subsequent
gelling treatment and will become smooth through surface
tension.
The above discussed and other advantages of the present invention
will be apparent to and understood by those skilled in the art from
the following detailed description and drawings.
BRIEF DISCUSSION OF THE DRAWINGS
Referring now to the drawings wherein like elements are numbered
alike in several figures:
FIG. 1 is a cross-sectional elevation view of a substrate material
used in accordance with the process and product of the present
invention.
FIG. 2 is a cross-sectional elevation view showing the first step
in the process of the present invention.
FIG. 3 is a cross-sectional elevation view showing a second step in
the process of the present invention wherein a covering has been
provided after the second zone has been coated on the
substrate.
FIG. 4 is a cross-sectional elevation view of a third step in the
process of the present invention indicating the graining
operation.
FIG. 5 is a cross-sectional elevation view of a fourth step in the
process of the present invention showing polymerization via a
radiation initiator.
FIG. 6 is a cross-sectional elevation view of the final product
provided in accordance with the process of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention provides a novel process for obtaining
selective areas or zones of distinctive appearance, i.e., matting
or graining on a synthetic covering surface. In accordance with the
present invention, this improved process includes, depositing a
polymeric coating which contains at least one radiation initiator
for polymerization onto at least a first selected area or zone on
an expandable or non-expandable support substrate. Next, at least
one second coating comprised of a crosslinkable monomer is
deposited onto a second selected area on the substrate. This second
area or zone may encompass at least a portion of the first area.
Thereafter, pre-gelling is performed on the deposited material
followed by a graining operation which is carried out over at least
a portion of the substrate surface. The synthetic covering in the
first zone or area is then polymerized by radiation initiation
wherein the particular appearance thereof is fixed to the
substrate. Thereafter, gelling is carried out wherein the polymer
which has not been fixed by radiation initiation will flow, i.e.,
fluidize, such that the grained appearance in the second area or
zone will disappear, i.e., smooth over. This gelling may also cause
some expansion of the polymer on the substrate.
It should be appreciated that "radiation initiator" may be any
suitable initiator which is decomposed or modified by energy
radiation, for example, by ultraviolet rays, to form free radicals
or ions which are required for a chain propogation in a
polymerization reaction.
In a preferred embodiment of the present invention, an ink or
extender containing an ultraviolet polymerization initiator is
deposited on an expandable or non-expandable substrate in at least
the first zone described above. This preferred embodiment makes it
possible to initiate polymerization at localized or selected areas.
In other words, the polymerization reaction can be localized to
those areas where the ultraviolet initiator has been deposited,
this reaction taking place after graining so as to rigidify the
surface of the first zone and retain the matted (grained)
appearance of this surface during subsequent operations.
By way of example only, crosslinkable monomers suitable for use in
connection with the present invention include, but are not limited
to, the following compounds: ethylene glycol dimethacrylate,
ethylene glycol diacrylate, diethylene glycol dimethacrylate,
diethylene glycol diacrylate, triethylene glycol dimethacrylate,
triethylene glycol diacrylate, tetraethylene glycol dimethacrylate,
tetraethylene diacrylate, polyethylene glycol dimethacrylate,
polyethylene glycol diacrylate, 1,3-butylene glycol dimethacrylate,
1,4-butylene glycol dimethacrylate, 1,3-butylene glycol diacrylate,
1,4-butylene glycol diacrylate, 1,6-hexanediol dimethacrylate,
1,6-hexanediol diacrylate, neopentyl glycol diacrylate, neopentyl
glycol dimethacrylate, (ethoxylated) bis-phenol A dimethacrylate,
divinylbenzene, divinyltoluene, trimethylolpropane trimethacrylate,
trimethylolpropane triacrylate, pentaerythritol triacrylate,
glyceryl trimethacrylate, pentaerythritol tetracrylate and
pentaerythritol tetramethacrylate. It will be appreciated that
particularly preferred compounds are 1,4-butylene glycol
dimethacrylate and trimethylolpropane trimethacrylate (Example
2).
Besides the above listed monomer compounds, which all have at least
two propagation sites, monomeric compounds possessing only one
propagation site may be added thereto. The coating containing the
crosslinkable monomer should contain 1 to 50%, preferably about
11%, by weight of monomer possessing at least two chain propagation
sites, optionally mixed with monomers possessing one chain
propagation site.
In the case where the matt effect is desired in the joint area of a
covering so as to imitate ceramic tiling, the ink containing the
radiation initiator can also contain an expansion inhibitor.
Conversely, in the case where the matt effect is desired in the
area of a design applied onto an expanded zone, the ink or extender
obviously will not contain an expansion inhibitor. It will be
appreciated that conventional expansion inhibitors, preferably
trimellitic anhydride (TMA) may be utilized by the present
invention.
Preferable ultraviolet polymerization initiators include
DAROCUR.RTM.1173 (2-hydroxy-2-methyl-1-phenyl-propan-1-on) or
DAROCUR.RTM.1116
(1-(4-isopropylphenyl)-2hydroxy-2-methyl-propan-1-on) manufactured
by Merck in amounts of from 1 to 50%, preferably 20%, by weight of
the ink or of the extender. Other compounds include, but are not
limited to, the following: benzophenone, 2-chloro-thioxanthone,
2-methylthioxanthone, 2-isopropyl-thioxanthone, benzoin,
4,4'-dimethoxybenzoin, benzoin ethyl ether, benzoin isopropyl
ether, benzyldimethylketal, 1,1,1-trichloroacetophenone,
1-phenyl-1,2-propanedione-2-(ethoxycarbonyl)-oxime,
diethoxyacetophenone, dibenzosuberone, DAROCUR.RTM.1398
1-(3,4-dimethylbutyl)-2-hydroxy-2-methyl-propan-1-on),
DAROCUR.RTM.1174 (1-(4-chlorobutyl)-2-hydroxy-2-methyl-propan-1-on)
and DAROCUR.RTM.1020
(1-(4-tertiobutyl)-2-hydroxy-2-methyl-propan-1-on). It should be
understood that at least two different radiation initiators, in the
same zone or in different zones and different layers, may also be
used in conjunction with the process of the present invention.
In accordance with one embodiment of the present invention, the
synthetic covering may be smoothed by surface tension which is
provided during gelling, either by utilizing a mechanical smoothing
treatment with a roller or by carrying out a preferably slight hot
graining operation. It will be appreciated that another way of
accomplishing the smoothing operation is to expose the final
synthetic covering (for example, when the final product leaves an
expansion oven), to infrared radiation so as to assist the
smoothing operation of the product surface (as shown in FIG. 6 and
discussed in Example 1).
In an alternative embodiment of the present invention, the method
of producing a floor or wall covering is facilitated by
polymerizing the monomer at selected intervals. In the alternative
embodiment, the second zone may be directly initiated or indirectly
initiated by using an agent for energy transfer by radiation, so
that each of the initiation stages is triggered by a specific
physiochemical condition. In this manner, it is possible to
separate the polymerization initiation in the selected zones in
accordance with the initiators and/or physiochemical initiation
properties. It will be appreciated that the polymerization
initiation energy provided by radiation in a first zone should not
initiate the polymerization of a second or other zone. This
above-described separation of the initiation conditions thus make
it possible to polymerize one selected zone and fix its particular
appearance and subsequently to polymerize a second zone without
deterioration of the appearance of the first zone. Preferably, the
initiation of the polymerization of the second zone is by direct
radiation or via an energy transfer agent which may be effected by
X-rays, an electron beam or gamma radiation. In order for the
energy transfer agent to be able to exert its full effects, the
energy transfer agent must act on a covering product in which
sufficient mobility of the crosslinkable monomer is assured. This
condition is best effected by heating the synthetic covering in an
oven, preferably the oven wherein the gelling and/or optional
expansion steps are carried out. Alternatively, the energy transfer
agent may act on the covering product upon leaving this oven, i.e.,
while the product is still at a sufficiently high temperature.
In accordance with the above-described embodiment, the
polymerization in the first zone can be achieved by the techniques
described below in the Examples while the polymerization in the
second zone can be provided by suitable physiochemical means.
Moreover, the polymerization of the second zone can be done without
major modifications to production lines for existing floor
coverings. It will be appreciated that the monomers to be used, the
localized application techniques in the various zones, and, in
general, the overall technological process described above is
identical, mutatis mutandis, to that which is described below in
the Examples.
It should be understood that the method used for effecting
initiation in the second zone by radiation means if, for example,
trimethylolpropane trimethacrylate is used as the monomer, is fully
described by Salmon and Loan, J. Appl. Polym. Sci., 16, 671
(1972).
When electron beams are used in accordance with the present
invention to initiate the polymerization reaction, a preferred
apparatus is the ELECTROCURTAIN apparatus manufactured by Ateliers
de Charmilles (Energy Sciences International) of Geneva
(Switzerland), using sufficient energy to penetrate into the proper
depth of the layer which is to be crosslinked, for example, energy
on the order of 175 KV for doses of 2 Mrads have been found
sufficient.
It will be appreciated that the process of matting in accordance
with the present invention may also be applied to relief products
produced by silk-screen techniques.
The following two examples are provided to show preferred
embodiments of the process and product of the present
invention:
EXAMPLE 1
Referring first to FIG. 1, the support of the synthetic covering
preferably consists of a substrate 1 having a coating, in an amount
of 500 g/m.sup.2, of an expandable or foamable plastisol 2. On this
expandable plastisol coating 2, a conventional ink containing an
expansion inhibitor and about 20% of the ultraviolet initiator
DAROCUR.RTM.1173 or 1116 is deposited in a first selected area or
zone in one or more stages in accordance with the decoration which
is an imitation of a tiled joint design 3 (see FIG. 2). An ink
containing an ultraviolet initiator is also deposited in accordance
with any desired decorative design 4. It will be appreciated that
the ink can be replaced by an extender (i.e., a solution without
dye stuff or pigment) depending upon the desired decorative effect
to be obtained. Preferably, this deposition (of ink or extender) is
effected by a photogravure or silk screen technique.
Referring now to FIG. 3, thereafter, a transparent plastisol
coating is deposited over the entire surface to serve as a wear
layer 5. This wear layer 5 coating contains an acrylic monomer
ROCRYL .RTM.980 or some other monomer compatible with the chosen
initiator. Next, pre-gelling is carried out at the convention
pre-gelling temperature which is usually between about 100.degree.
C. and 160.degree. C.
In FIG. 4, the step of graining the entire surface by means of a
graining roll under a pressure which depends upon the degree of
mattness desired is shown. This graining step is usually conducted
at a conventional temperature which is somewhere below 100.degree.
C. It will be appreciated that the pre-gelling and graining stages
can be carried out in a single step using a sufficiently heated
graining roll. Referring now to FIG. 5, the synthetic covering is
passed under an ultraviolet lamp 7 wherein the zone of material
containing the ultraviolet initiator is crosslinked so that the
grained or matted appearance of this zone is fixed thereby.
Thereafter, the synthetic covering product obtained therefrom is
passed for between 1-2 minutes 30 seconds through an oven of about
200.degree. C. wherein the expandable coating 2 is expanded into
the areas which do not contain an expansion inhibitor as well as to
gel and fluidize the zone which has not been polymerized during the
ultraviolet initiation. As a result, the heat from the oven will
cause fluidization which has the effect of smoothing the grained
surface, while the zone which has been grained and crosslinked
during the ultraviolet initiation retains its grained, i.e.,
matted, appearance. The resultant final product is shown in FIG.
6.
EXAMPLE 2
The same procedure as used in Example 1 is followed in this
Example, the PVC being replaced by a copolymer of vinyl chloride
(95%) and vinyl acetate (5%), all the other components remaining as
before.
The following composition was used:
______________________________________ Parts by weight
______________________________________ VC/VA copolymer resin 100.00
containing 5% of vinyl acetate Stabilizer (barium/zinc) 3.00
Monomer (trimethylolpropane 20.00 trimethacrylate) Plasticizers
57.00 Deaerating agent 3.3
______________________________________
The pre-gelling is preferably carried out on a drum at 130.degree.
C.; although this temperature can be exceeded, depending upon the
speed of travel of the covering product. It has been found that the
above composition provides better gelling and smoothing.
While preferred embodiments have been shown and described, various
modificatons and substitutions may be made thereto without
departing from the spirit and scope of the invention. Accordingly,
it is to be understood that the present invention has been
described by way of illustrations and not limitation.
* * * * *