U.S. patent application number 09/793558 was filed with the patent office on 2001-09-20 for plastic roof tiles.
Invention is credited to Zhang, Chengjie.
Application Number | 20010022055 09/793558 |
Document ID | / |
Family ID | 4165578 |
Filed Date | 2001-09-20 |
United States Patent
Application |
20010022055 |
Kind Code |
A1 |
Zhang, Chengjie |
September 20, 2001 |
Plastic roof tiles
Abstract
The present invention is directed to a shaped plastic roof tile
preferably one shaped like a slate tile. The tile is constructed of
the combination of a thermoplastic, preferably one or more
polyolefin polymers, and a chlorine containing polymer in an amount
to provide a final chlorine content to the tile of between 1% and
65% by weight. The polyolefin polymer is preferably a combination
of polyethylene and polypropylene derived from recycled material.
The chlorine containing polymer is one or more polymers selected
from the group consisting of polyvinyl chloride (PVC), chlorinated
polyvinyl chloride (CPVC), polyvinylidene dichloride (PVDC),
chlorinated polyolefin, acrylate modified PVC, neoprene rubber,
copolymers of vinyl chloride with ethylene, propylene, vinyl
acetate, vinyl dichloride, and butadiene, copolymers of vinylidene
chloride with butyl acrylate and nitrile, and polymer blends of PVC
with acrylonitrile-butadiene-styrene (ABS),
acrylic-styrene-acrylonitrile (ASA), nitrile rubber, and polyvinyl
acetate (EVA). Preferably, the chlorine containing polymer is
recycled neoprene rubber.
Inventors: |
Zhang, Chengjie; (Aurora,
CA) |
Correspondence
Address: |
DENNISON ASSOCIATES
133 RICHMOND STREET WEST
SUITE 301
TORONTO
ON
M5H 2L7
CA
|
Family ID: |
4165578 |
Appl. No.: |
09/793558 |
Filed: |
February 27, 2001 |
Current U.S.
Class: |
52/309.1 ;
52/518 |
Current CPC
Class: |
E04D 1/20 20130101 |
Class at
Publication: |
52/309.1 ;
52/518 |
International
Class: |
E04C 002/20; E04D
001/20 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 16, 2000 |
CA |
2,301,420 |
Claims
We claim:
1. A shaped plastic roof tile, the tile being formed of a
combination of a thermoplastic and a chlorine containing polymer in
an amount to provide a final chlorine content to the tile of
between 1% and 65% by weight.
2. A roof tile according to claim 1 wherein the thermoplastic is
one or more polyolefin polymers.
3. A roof tile according to claim 1 wherein the polyolefin polymer
is a combination of polyethylene and polypropylene derived from
recycled material.
4. A roof tile according to claim 2 wherein the chlorine containing
polymer is one or more polymers selected from the group consisting
of polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC),
polyvinylidene dichloride (PVDC), chlorinated polyolefin, acrylate
modified PVC, neoprene rubber, copolymers of vinyl chloride with
ethylene, propylene, vinyl acetate, vinyl dichloride, and
butadiene, copolymers of vinylidene chloride with butyl acrylate
and nitrile, and polymer blends of PVC with
acrylonitrile-butadiene-styrene (ABS),
acrylic-styrene-acrylonitrile (ASA), nitrile rubber, and polyvinyl
acetate (EVA).
5. A roof tile according to claim 3 wherein the chlorine containing
polymer is PVC or recycled neoprene rubber or comboinations of PVC
and neoprene rubber.
6. A roof tile according to claim 1 wherein the polyolefin polymer
is present in an amount of from 50 to 95 percent by weight and the
chlorine containing polymer is present in an amount of from 5 to 50
percent by weight.
7. A roof tile according to claim 5 wherein the polyolefin polymer
is present in an amount of from 60 to 75 percent by weight and the
chlorine containing polymer is present in an amount of 25 to 40
percent by weight.
8. A roof tile according to claim 6 wherein the polyolefin polymer
is present in an amount of 65 to 70 percent by weight and the
chlorine containing polymer in an amount of 30 to 35 percent by
weight.
9. A roof tile according to claim 7 wherein the polyolefin polymer
is a combination of polyethylene and polypropylene.
10. A roof tile according to claim 8 wherein the polyolefin polymer
comprises from 5 to 75 percent by weight polyethylene and 25 to 95
percent by weight polypropylene.
11. A roof tile according to claim 8 wherein the polyolefin polymer
comprises from 20 to 50 percent by weight polyethylene and 50 to 80
percent by weight polypropylene.
12. A roof tile according to claim 11 wherein the polypropylene is
a rubber modified polypropylene.
Description
FIELD OF THE INVENTION
[0001] The present invention is directed to shaped plastic roof
tiles, particularly those shaped to have the appearance of slate
tiles and the process for manufacturing the tiles.
BACKGROUND OF THE INVENTION
[0002] There are many different roofing materials presently in use
including wood shakes and shingles, asphalt shingles, clay tiles,
metal panels and slate tiles. While asphalt shingles are the most
commonly utilized because of their lower cost and weight, other
materials are more preferred for their aesthetic appeal. Amongst
such materials, clay and slate are particularly desirable for their
longevity and appearance. Clay and slate do however have drawbacks.
There is only a limited supply of slate which makes it very
expensive as a roofing material. In addition, clay and slate are
extremely heavy materials requiring that the roof on which they are
to be installed be specially engineered to support the weight,
which also increases the cost of the finished roof.
[0003] There have been attempts to construct tiles of plastic
material having the appearance of clay and slate but which do not
have some of the drawbacks. Such plastic tiles are of relatively
low weight and generally do not require a specially engineered
roof, being able to be installed on standard roof construction.
Plastic also has an advantage of being able to be formulated to
have a long life. Examples of such plastic tiles are described in
U.S. Pat. Nos. 5,992,116; 5,946,877; 5,630,305; 5,615,523 and
5,295,339 among others.
[0004] There still remains a need for an economical to manufacture
shaped plastic roof tiles having the appearance of more expensive
roofing materials such as slate.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a shaped plastic roof
tile. The tile is constructed of the combination of a thermoplastic
and a chlorine containing polymer in an amount to provide a final
chlorine content to the tile of between about 1% and about 65% by
weight based upon the total weight of the tile.
[0006] In an aspect of the invention, the thermoplastic is a
polyolefin.
[0007] In another aspect of the invention, the polyolefin polymer
is a combination of polyethylene and polypropylene derived from
recycled material.
[0008] In yet another aspect of the invention, the chlorine
containing polymer is one or more polymers selected from the group
consisting of polyvinyl chloride (PVC), chlorinated polyvinyl
chloride (CPVC), polyvinylidene dichloride (PVDC), chlorinated
polyolefin, acrylate modified PVC, neoprene rubber, copolymers of
vinyl chloride with ethylene, propylene, vinyl acetate, vinyl
dichloride, and butadiene, copolymers of vinylidene chloride with
butyl acrylate and nitrile, and polymer blends of PVC with
acrylonitrile-butadiene-styrene (ABS),
acrylic-styrene-acrylonitrile (ASA), nitrile rubber, and polyvinyl
acetate (EVA).
[0009] In yet another aspect of the invention, the chlorine
containing polymer is recycled neoprene rubber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A preferred embodiment of the present invention is
illustrated in the attached drawings in which:
[0011] FIG. 1 is a top plan view of a plastic slate-like tile of
the present invention;
[0012] FIG. 2 is a top plan view of the tile of FIG. 1 being
installed on a roof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] A preferred embodiment of a plastic roof tile of the present
invention is illustrated in the attached figures generally
indicated by the numeral 10. The roof tile is sized approximately
equal to that of traditional slate tiles having a width of
approximately 12 inches and a total height of approximately 18
inches. The bottom portion 12 of the roof tile 10 has a slightly
reduced width relative to the top portion of the roof tile 10 to
provide for the proper reveal for the esthetic appearance of the
tile 10 once it is installed on the roof. This bottom portion 12 of
the roof tile is also provided with a slate like appearance by
texturing the surface of the roof tile to provide for the
appearance of slate. The reduced width bottom portion 12 extends
upwardly approximately 6 inches from the bottom of the tile and the
slate texture extends upwardly to approximately half of the height
of the plastic tile 10. The plastic tile 10 is provided with guide
marks 14 on either side to allow for proper alignment of the tile
10 and thereby provide for the proper reveal of the tile 10 as
desired. Traditionally slate tiles are laid with either a 6 or 7
inch reveal and rule markings are provided on either side of the
tile 6 to 7 inches down from the top edge of the tile. The use of
these markings will be explained below.
[0014] The tile 10 is also preferably provided with one or more
fastening guides 16 to indicate to the installer the proper
location for the fasteners for attaching the roof tile to the roof
surface. Preferably the tile is attached to the roof surface with
suitable nails and nailing points are provided on either side of
the tile in the proper position for a 6 or 7 inch reveal of the
tile. To further aid in the installation of the tile courses, each
of the tiles is provided with a vertical guide line 18 centrally
located in the upper portion of the tile and extending vertically
downwardly. There may be circumstances when it is desired to clip
the top corners of the tile and score lines 20 may be provided to
allow this to be accomplished in an easier manner.
[0015] To allow the plastic tile 10 of the present invention to be
utilized in hip and ridge locations where two roof surfaces meet at
an angle, a special hip and ridge tile may be provided with a bend
line provided extending vertically through the centre of the tile.
This would allow the tile to be easily bent inwardly or outwardly
along the bend line to accommodate hip and ridge applications.
[0016] A typical installation of the shaped plastic tile 10 of the
present invention on a roof surface is illustrated in FIG. 2. To
provide a suitable starter course 22, the bottom portion of a
series of tiles 10 are cut off and the top portions rotated
180.degree. and attached to the roof surface leaving a suitable
spacing, generally on the order of a quarter to one eighth of an
inch, between each of the starter tiles. The first tile course is
laid over the starter course with each tile 10 of the first tile
course centrally located to overlie the gap between the starter
course tiles. The tiles 10 are attached to the roof in a suitable
manner leaving a one eighth to one quarter inch space between the
upper edges of the tiles. The succeeding courses are then laid on
top of the previous tile course in a similar manner. Due to the
presence of the centering line 18 and the graduated exposure line
or guide marks 14, the installation of the succeeding courses of
the tiles 10 is simple and no guidelines or guide boards need be
provided on the roof. The tile 10 for the second tile course is
centered between the two centering lines of the tiles 10 of the
first course with the reveal lines of the second tile for the
required reveal lining up with the top edges of the tiles of the
first tile course. The tiles 10 are then nailed to the roof and the
rest of the roof is laid in a similar manner.
[0017] The plastic roof tiles of the present invention are
constructed of the combination of a thermoplastic, preferably a
polyolefin based polymer, and a chlorine containing polymer in an
amount to provide a final chlorine content to the tile of between
about 1 percent and about 65 percent by weight. The provision of
the chlorine content in the tile provides the tile with suitable
fire retardant property. Preferably, the polyolefin polymer is one
or more polymers selected from a polyethylene and a polypropylene,
most preferably a combination of a polyethylene and a
polypropylene. The polypropylene may be a homopolymer or a
copolymer with another suitable thermoplastic elastomer such as
EPDM, ethylene propylene terpolymer. The polyethylene may be high
density polyethylene (HDPE) low density polyethylene (LDPE) or
linear low density polyethylene (LLDPE). While the polyolefin
polymer may be virgin material, it is preferred that the polyolefin
be derived from recycled material. By utilizing recycled material,
the cost for the tile is greatly reduced.
[0018] The chlorine containing polymer is preferably one or more
polymers selected from the group consisting of polyvinyl chloride
(PVC), chlorinated polyvinyl chloride (CPVC), polyvinylidene
dichloride (PVDC), chlorinated polyolefin, acrylate modified PVC,
neoprene or polychloroprene rubber, copolymers of vinyl chloride
with ethylene, propylene, vinyl acetate, vinyl dichloride, and
butadiene, copolymers of vinylidene chloride with butyl acrylate
and nitrile, and polymer blends of PVC with
acrylonitrile-butadiene-styrene (ABS),
acrylic-styrene-acrylonitrile (ASA), nitrile rubber, and polyvinyl
acetate (EVA). Once again, while the chlorine containing polymer
may also be virgin material, it is preferred for reasons of economy
that the chlorine containing polymer also be derived from recycled
material. Particularly preferred chlorine containing polymers are
polyvinyl chloride or neoprene rubber, most preferably neoprene
rubber. The neoprene rubber may be virgin or recycled material,
virgin material generally being not cross-linked while recycled
material is generally cross-linked. Cross-linked recycled neoprene
rubber is most preferred as the chlorine containing polymer.
[0019] The polyolefin based polymer is generally present in an
amount of 50 to 95 percent by weight and the chlorine containing
polymer is generally present in the amount of 5 to 50 percent by
weight. Preferably, the polyolefin polymer is present in an amount
of 60 to 75 percent by weight and the chlorine containing polymer
is present in an amount of 25 to 40 percent by weight. Most
preferably the polyolefin based polymer is present in an amount of
65 to 70 percent by weight and the chlorine containing polymer in
an amount of 30 to 35 percent by weight.
[0020] When the polyolefin based polymer is a combination of
polyethylene and polypropylene it is preferred if the formulation
contains 5 to 75 percent polyethylene with the balance being
polypropylene. More preferably the formulation contains 20 to 50
percent by weight of polyethylene and 50 to 80 percent by weight of
polypropylene. In order to improve the impact resistance of the
tile formulated from the material, it is preferred if the
polypropylene is a rubber or EPDM modified polypropylene.
[0021] The shaped plastic roof tiles of the present invention may
be colored to any desired color by the addition of pigments
commonly employed in the manufacture of molded thermoplastic
materials. Depending upon the nature of the recycled material used
for the shaped plastic tile, additional pigments may or may not be
required.
[0022] The plastic roof tiles are manufactured by mixing the
polyolefin or other thermoplastic based polymer and the chlorine
containing polymer to provide for a relatively uniform mixture and
then molding the mixture into the roof tile shape. When utilizing
virgin material in the form of powder, pellets or flakes, the
polyolefin based polymer powders and chlorine containing polymer
powder are mixed and then molded utilizing either compression
molding or injection molding.
[0023] When utilizing recycled material it may be necessary to
regrind the material prior to the molding depending upon the
physical nature of the recycled material. If the recycled material
is provided in a small enough particle size it may be handled in a
manner similar to virgin material by merely mixing, then melting
and molding the material utilizing compression molding or injection
molding. If the recycled material has not been reduced in particle
size or bulk it is generally necessary to first reduce the bulk in
particle size by grinding or densifying the material into suitable
size particles for the molding operation.
[0024] As noted above the shaped plastic tile of the present
invention is most preferably constructed of 65 to 70 percent by
weight of a polyolefin based polymer containing 20 to 50 percent by
weight polyethylene and 50 to 80 percent polypropylene in
combination with 30 to 35 percent neoprene rubber as a chlorine
containing polymer. The use of the neoprene rubber as a chlorine
containing polymer provides other advantages such as providing a
suitable gray scale to the colour of the tile. In addition, the
carbon black present in the rubber also provides UV protection for
the tile. The polyolefin based polymer and neoprene rubber are
preferably recycled material which are mixed together in the proper
proportion and densified to reduce the bulk and particle size. The
densification operation may be accomplished by any method known in
the art such as the use of a screw extruder or utilizing suitable
knives in a chopping apparatus. During the densification operation
utilizing suitable knives, the heat generated by the friction
between the knives and the polymers melts the plastic and causes
the plastic to stick to the rubber particles. Once the bulk and
particle size has been reduced, the mixture may be cooled with
water then ground into smaller particle sizes. These smaller
particle sizes are remelted, and molded using compression molding
or injection molding. For compression molding, the particles are
melted and placed into a compression mold having the suitable shape
and features for the roof tile and then pressed to form the final
roof tile. The roof tile may also be formed by an injection molding
operation utilizing a suitable injection mold.
[0025] The use of the chlorine containing polymer results in a
chlorine content in the formulation in the range of 1 to 65 percent
by weight. The presence of the chlorine provides for increased
resistance of the tiles in a fire situation. Should the tiles be
exposed to an open flame, hydrogen chloride would be released
during the burning of the chloride polymer. Further flame
development would be interrupted by the hydrogen chloride reaction
with hydrogen atoms and hydroxyl radicals thus providing a suitable
fire rating to the roofing material. In addition, the presence of
the chlorine also reduces dripping of the thermoplastic elastomer
especially polyolefins during burning.
[0026] The shaped roofing tiles of the present invention provide
for an economical manufactured roof tile that replicates the
classic look of more expensive materials such as slate without the
added weight or cost of traditional materials. A roofing system
utilizing the roofing tiles of the present invention is as easy to
install as conventional asphalt shingles and requires no added
substructure as would be the case for slate tiles as well as some
other imitation tile.
[0027] Although various preferred embodiments of the present
invention have been described herein in detail, it will be
appreciated by those of skill in the art that variations may be
made thereto without departing from the spirit of the invention or
the scope of the appended claims.
* * * * *