U.S. patent application number 11/175240 was filed with the patent office on 2005-11-03 for laminate structure with polycarbonate sheets and method of making.
This patent application is currently assigned to 3-Form. Invention is credited to Goodson, Boyd Talley, Goodson, Raymond Lynn.
Application Number | 20050241759 11/175240 |
Document ID | / |
Family ID | 46299457 |
Filed Date | 2005-11-03 |
United States Patent
Application |
20050241759 |
Kind Code |
A1 |
Goodson, Raymond Lynn ; et
al. |
November 3, 2005 |
Laminate structure with polycarbonate sheets and method of
making
Abstract
Disclosed is a decorative laminate structure having at least two
sheets of polycarbonate and at least one decorative image layer
there-between two sheets of polycarbonate, and a method of making
the decorative laminate structure. Through heat and pressure the
sheet layers and the decorative image layer are bonded together
resulting in a decorative laminate structure of this invention.
This product is intended for use primarily to produce decorative
articles which include counter tops, table tops, cabinet doors,
game boards, toys, panels for shower stalls, hot tubs,
markerboards, indoor and outdoor signs, seamless vanity tops
including sink, soap dish, back splash, flooring and others.
Inventors: |
Goodson, Raymond Lynn;
(Sandy, UT) ; Goodson, Boyd Talley; (Salt Lake
City, UT) |
Correspondence
Address: |
WORKMAN NYDEGGER
(F/K/A WORKMAN NYDEGGER & SEELEY)
60 EAST SOUTH TEMPLE
1000 EAGLE GATE TOWER
SALT LAKE CITY
UT
84111
US
|
Assignee: |
3-Form
|
Family ID: |
46299457 |
Appl. No.: |
11/175240 |
Filed: |
July 6, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11175240 |
Jul 6, 2005 |
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10465465 |
Jun 18, 2003 |
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11175240 |
Jul 6, 2005 |
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10086269 |
Mar 1, 2002 |
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60389392 |
Jun 18, 2002 |
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60273076 |
Mar 5, 2001 |
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Current U.S.
Class: |
156/308.2 |
Current CPC
Class: |
Y10T 428/2848 20150115;
B32B 2307/412 20130101; Y10T 428/269 20150115; B32B 37/185
20130101; B44C 1/105 20130101; Y10T 428/216 20150115; Y10T 428/2813
20150115; B32B 27/12 20130101; B32B 2317/16 20130101; Y10T 428/253
20150115; B32B 37/1027 20130101; B32B 2369/00 20130101; B32B 27/36
20130101; B32B 2318/04 20130101; B32B 2317/12 20130101; Y10T 428/26
20150115; B32B 2307/584 20130101; B32B 2309/105 20130101; B32B
37/04 20130101; B32B 2309/04 20130101; B32B 2309/02 20130101; B32B
2309/12 20130101; B32B 2307/414 20130101; B32B 2451/00 20130101;
B32B 37/00 20130101; B32B 38/06 20130101; B32B 37/08 20130101; Y10T
428/23 20150115; Y10T 428/24942 20150115; B32B 2305/18 20130101;
B32B 27/32 20130101; Y10T 428/31797 20150401 |
Class at
Publication: |
156/308.2 |
International
Class: |
B32B 031/20 |
Claims
What is claimed is:
1. A method of making a decorative laminate structure comprising:
providing a first sheet comprising polycarbonate, the first sheet
having a thickness between 0.13 and 12.7 mm; providing a second
sheet comprising polycarbonate, the second sheet having a thickness
between 0.13 and 12.7 mm; providing a decorative image layer
between the first and second sheet; and heating and pressing the
first and second sheet with the decorative image layer
there-between at a maximum temperature between 193 and 249.degree.
C. and a maximum pressure between 138 and 2069 kPa, wherein the
time at maximum temperature and pressure is between 0.1 and 20
minutes.
2. The method of claim 1, wherein heating and pressing of the first
and second sheet with the decorative image layer there-between
occur at a maximum temperature between 210 and 227.degree. C. and a
maximum pressure between 448 and 662 kPa, wherein the time at the
maximum temperature and pressure is 0.1 to 5 minutes.
3. The method of claim 1, wherein heating and pressing of the first
and second sheet with the decorative image layer there-between
occur at a maximum temperature between 210 and 227.degree. C. and a
maximum pressure of 634 kPa (92 psi), wherein the time at the
maximum temperature and pressure is about 0.17 minute.
4. The method of claim 1, wherein the decorative image layer is
selected from the group consisting of fabric, metallic wire, rod,
bar, wood, stone, paper, and photographic images.
5. The method of claim 1, wherein the decorative image layer
comprises vegetation.
6. The method of claim 5, wherein vegetation is selected from the
group consisting of wood chips, grasses, thatch, flowers, flower
petals, wheat, grains, and natural papers.
7. The method of claim 1, wherein the decorative image layer
comprises crushed glass.
8. The method of claim 1, wherein the thickness of the first sheet
is between 0.74 and 10 mm thick.
9. The method of claim 1, wherein the thickness of the first sheet
is between 1.48 and 6.35 mm thick.
10. The method of claim 1, wherein the thickness of the first sheet
is between 2.22 and 6.35 mm thick.
11. The method of claim 1, wherein the thickness of the decorative
image layer is between 0.0254 and 1.524 mm thick.
12. The method of claim 1, wherein the thickness of the decorative
image layer is between 0.0254 and 0.05 mm thick.
13. The method of claim 1, wherein the thickness of the decorative
image layer is about 0.04 mm.
14. The method of claim 1, wherein the thickness of the second
layer is between 0.74 and 10 mm thick.
15. The method of claim 1, wherein the thickness of the second
layer is between 1.48 and 6.35 mm thick.
16. The method of claim 1, wherein the thickness of the second
sheet is between 2.22 and 6.35 mm thick.
17. The method of claim 1, further comprising removing air by
vacuum prior to heating and pressing.
18. The method of claim 1, further comprising cooling the first and
second sheet with the decorative image layer there-between at a
temperature between 10 to 149.degree. C. and pressure between 7 and
2069 kPa.
19. The method of claim 18, wherein cooling the first and second
sheet with the decorative image layer there-between is at a
temperature between 21.1 to 32.2.degree. C. and pressure between
448 and 662 kPa.
20. The method of claim 19, wherein cooling the first and second
sheet with the decorative layer there-between is at pressure
between 552 to 662 kPa.
21. The method of claim 19, wherein cooling the first and second
sheet with the decorative layer there-between is at pressure of 634
kPa.
22. The method of claim 1, further comprising providing a
protective layer, wherein the protective layer is applied on at
least one surface of the first sheet.
23. The method of claim 22, wherein the protective layer is a
bilayer film.
24. The method of claim 22, wherein the protective layer is
selected from the group consisting of UV-cured or
electron-beam-cured crosslinked acrylic, vacuum-cured or UV-cured
urethane, UV-cured or electron-beam-cured silicon with acrylic or
heat cured urethane or plastisol, and combinations thereof.
25. The method of claim 22, wherein the protective layer is
UV-cured or electron-beam-cured silicon.
26. The method of claim 1, further comprising providing cast paper
or embossing paper.
27. The method of claim 26, wherein cast paper or embossing paper
is selected from the group consisting of patent paper, patina,
matte, stucco, ostrich, reptilian, glitter, topaz, grid, and
allegro.
28. The method of claim 26, wherein the cast paper or embossing
paper is disposed between a metal plate and an exterior surface of
the first sheet or protective layer.
Description
RELATED APPLICATIONS
[0001] This application is a Divisional of U.S. patent application
Ser. No. 10/465,465 ('465), filed on Jun. 18, 2003, entitled
"Laminate Structure with Polycarbonate Sheets and Method of
Making", which claims priority to U.S. Provisional application Ser.
No. 60/389,392, filed Jun. 18, 2002, and is further a
continuation-in-part of U.S patent application Ser. No. 10/086,269
('269 application), filed on Mar. 1, 2002, entitled "Laminated
Article and Method of Making Same", which claims priority to U.S.
Provisional Patent Application Ser. No. 60/273,076, filed on Mar.
5, 2001, entitled "Lamination of Dissimilar Materials and Method
for Making Same". Each of the aforementioned patent applications is
incorporated herein by reference in its respective entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a decorative laminated
structure having decorative images and/or custom colors embedded
therein and a method of making the decorative laminated structure.
The decorative laminate structures according to the present
invention may be used not only in the construction industry as wall
coverings, as glazing for windows, in partitions, as decorative
paneling and in select furniture applications, but also in
high-heat and performance driven applications, such as automotive,
marine, lighting, flooring, and aerospace. One or both surfaces of
the articles may be textured during the formation of the
articles.
BACKGROUND OF THE INVENTION
[0003] There has been a great demand for translucent building
materials with decorative images, textures and colors.
Traditionally these materials have been made by mixing colors in
the base resin material limiting the options to only large runs
thus eliminating the possibility of customizing colors for each
project.
[0004] Laminate structures are composites made from any one of
several types of thermosetting plastic materials and may contain a
printed pattern or an image. However, to date, the production of
such laminated structures has often required complex processing
techniques, added production time, and/or additional capital. In
addition, these laminate structures could not be easily
thermoformed and were typically rigid and brittle. Also, certain
laminate materials which offer the prospect of providing improved
properties in decorative laminate structures often do not readily
adhere to adjacent layers, which then resulted in non-uniform
lamination or delamination after a period of use.
[0005] U.S. Pat. Nos. 5,894,048, 5,643,666, 5,998,028, 5,958,539,
6,025,069 and PCT Application No. WO 97/22474 disclose a decorate
laminate structure which uses polyethylene teraphtalate glycol
polyester (PETG polyester).
BRIEF SUMMARY OF THE INVENTION
[0006] In a first aspect, the invention provides a method of making
a decorative laminate structure including providing a first sheet
comprising polycarbonate, the first sheet having a thickness
between 0.13 and 12.7 mm, providing a second sheet comprising
polycarbonate, the second sheet having a thickness between 0.13 and
12.7 mm, and providing at least one a decorative image layer
between the first and second sheet. The first and second sheet with
the decorative image layer there-between are heated and pressed at
a maximum temperature between 193 and 249.degree. C. and a maximum
pressure between 138 and 2069 kPa. The time at maximum temperature
and pressure is between 0.1 and 20 minutes.
[0007] In another aspect, the invention provides a decorative
laminate structure including a first sheet comprising
polycarbonate, the first sheet having a thickness between 0.13 and
12.7 mm, a second sheet comprising polycarbonate, the second sheet
having a thickness between 0.13 and 12.7 mm, and at least one a
decorative image layer between the first and second sheet.
[0008] In yet another aspect, the invention provides a decorative
laminate structure including a first sheet comprising
polycarbonate, the first sheet having a thickness between 0.13 and
12.7 mm; a second sheet comprising polycarbonate, the second sheet
having a thickness between 0.13 and 12.7 mm; a third sheet of
polycarbonate, the third sheet having a thickness between 0.13 and
12.7 mm; at least one first decorative image layer between the
first and second sheet; and at least one second decorative image
layer between the second and third sheet.
[0009] These and other aspects are discussed in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention is better understood with reference to
the accompanying drawings and detailed description wherein:
[0011] FIG. 1 is a partially separated, cross-section of
substantially planar decorative laminate structure according to the
present invention.
[0012] FIG. 2 is a partially separated, cross-section of a
substantially planar decorative laminate structure according to the
present invention.
[0013] FIG. 3 is an illustration of decorative laminate
structures.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The following detailed description is provided as an aid to
those desiring to practice the present invention. The following
description is not to be construed as limiting the instant
invention, since those of ordinary skill in the art will realize
that various modifications, changes and substitutions made can be
made in various materials and methods disclosed herein, without
departing from the spirit or the scope of the present inventive
discovery. Instead, the present invention is defined by the claims
appended hereto and the equivalents encompassed thereby.
[0015] The invention relates to a decorative laminate structure and
a method of making the decorative laminate structure. The laminate
structure has aesthetically desirable surface appearance, for
example that of wood, stone, kiln cast glass, and solid surface
saturated colored products.
[0016] The decorative laminate structures include:
[0017] (1) a first sheet comprising polycarbonate, the first sheet
having a thickness between 0.13 and 12.7 mm;
[0018] (2) a second sheet comprising polycarbonate, the second
sheet having a thickness between 0.13 and 12.7 mm; and
[0019] (3) at least one a decorative image layer between the first
and second sheet.
[0020] The decorative laminate structures also include:
[0021] (1) a first sheet comprising polycarbonate, the first sheet
having a thickness between 0.13 and 12.7 mm;
[0022] (2) a second sheet comprising polycarbonate, the second
sheet having a thickness between 0.13 and 12.7 mm;
[0023] (3) a third sheet of polycarbonate, the third sheet having a
thickness between 0.13 and 12.7 mm;
[0024] (4) at least one first decorative image layer between the
first and second sheet; and
[0025] (5) at least one second decorative image layer between the
second and third sheet.
[0026] The methods of making a decorative laminate structure
include:
[0027] (1) providing a first sheet comprising polycarbonate, the
first sheet having a thickness between 0.13 and 12.7 mm;
[0028] (2) providing a second sheet comprising polycarbonate, the
second sheet having a thickness between 0.13 and 12.7 mm;
[0029] (3) providing at least one a decorative image layer between
the first and second sheet; and
[0030] (4) heating and pressing the first and second sheet with the
decorative image layer there-between at a maximum temperature
between 193 and 249.degree. C. and a maximum pressure between 138
and 2069 kPa, wherein the time at maximum temperature and pressure
is between 0.1 and 20 minutes.
[0031] The method may further comprise a step in which the first
and second sheet with the decorative image layer there-between are
cooled at pressure between about 7 and 2065 kPa.
[0032] According to FIG. 1, the decorative laminate structure 1
comprises a first polycarbonate sheet 2, a decorative image layer
3, and a second polycarbonate sheet 4.
[0033] According to FIG. 2 the decorative laminate structure 5
according to the present invention comprises a first polycarbonate
sheet 6, a decorative image layer 7, and a second polycarbonate
sheet 8. The decorative laminate structure further includes a
protective layer 9 including a hard coat 10.
[0034] The traditional laminate structures and method of making the
laminate structures often require laminating enhancers such as
adhesives or coupling agents. A great advantage of this invention
is that the method of making the decorative laminate structure as
described herein does not require use of the laminating enhancers.
Preferably, heat and pressure applied to the laminated structure
are sufficient to bond the first sheet, the second sheet and the
decorative image layer.
[0035] Furthermore, one possible explanation for the success of the
decorative laminate structure of this invention is based on the
polycarbonate properties. For example, properties such as
high-melting temperature, increased rigidity, strength, and high
impact resistance of the polycarbonate allow the decorative
laminate structure of this invention to be used in high-heat and
performance driven applications such as automotive, marine,
lighting, flooring, commercial construction, signage, exterior use
and aerospace.
[0036] As used herein, "first," "second," and "third" in connection
with the polycarbonate sheets are arbitrary and do not refer to
positions and order of the sheet layers relative to each other and
the decorative image layer. Furthermore, the first and second
sheets are not necessarily the outermost sheets of the decorative
laminate structure according to the invention. Therefore, the
decorative laminate structure may contain multiple sheets layers on
each side of the decorative image layer as well as multiple
decorative image layers.
[0037] The sheet material used in the preparation of the decorative
laminate structures of our invention may be transparent,
translucent, or one sheet may be opaque, depending on the
particular aesthetic effect desired. The first and second sheets
may differ in degree of transparency or translucency and also in
color.
[0038] The thickness of the sheet layers used in the preparation of
the decorative laminate structure depends upon a number of factors
such as functionality, weight, cost, etc. The first sheet has a
thickness in the range of about 0.13 to 12.7 mm (0.005-0.5 inch),
preferably about 0.74 to 10 mm (0.03-0.4 inch), more preferably in
the range of about 1.48 to 6.35 mm (0.063-0.126 inch), and most
preferably in the range of 2.22 to 6.35 mm. The second sheet
typically has a thickness in the range of about 0.13 to 12.7 mm
(0.005-0.5 inch), preferably about 0.74 to 10 mm (0.03-0.5 inch),
more preferably in the range of about 1.48 to 6.35 mm (0.063-0.126
inch), and most preferably in the, range of 2.22 to 6.35 mm. The
thickness of the sheets is limited only by functionality. For
example, the thickness of the sheet layers is greater in decorative
laminates structures used in horizontal applications, such as work
surfaces, flooring, and ceilings.
[0039] The first and the second sheets of the decorative laminated
structure according to the present invention comprise
polycarbonate. The term "polycarbonate" refers to polycarbonates
for use in the production of the decorative laminated structures of
the invention. Polycarbonates are thermoplastic, aromatic polymers
and include homopolycarbonates, copolycarbonates and
copolyestercarbonates and mixtures thereof which have average
molecular weights of about 8,000 to more than 200,000, preferably
of about 20,000 to 80,000 and an intrinsic viscosity (I.V.) of 0.40
to 1.5 dl/g as measured in methylene chloride at 25.degree. C.
Preferably, the glass transition temperature of polycarbonates
ranges from 145 to 148.degree. C. The material's "glass transition
temperature (Tg)" is defined as the temperature below which
molecules have very little mobility. On a larger scale, polymers
are rigid and brittle below their glass transition temperature and
elastic above it. Tg is usually applicable to amorphous phases and
is commonly applicable to glasses and plastics.
[0040] Polycarbonates are a well known class of high impact
resistant thermoplastic resins characterized by optical clarity and
high ductility. Polycarbonates can be defined as polymers
containing recurring carbonate groups (--O--CO--O--) in the main
chain. Aromatic polycarbonates are of particular interest in the
practice of this invention. These polymers are known per se and are
generally prepared by reacting a dihydric phenol, or bisphenol,
with a carbonate precursor, e.g., phosgene, a halogen formate, or a
carbonate ester (see German Offenlegungsschriften 2,063,050;
1,561,518; 1,570,703; 2,211,956; 2,211,957 and 2,248,817; French
Patent 1,561,518; and the monograph by H. Schnell, "Chemistry and
Physics of Polycarbonates", Interscience Publishers, New York,
N.Y., 1964, all of which are incorporated herein by reference).
[0041] For the polycarbonate, commercially available products may
be used and, among them, polycarbonates obtained by the use of the
bisphenol A are preferred for their good mechanical properties and
also excellent transparency. For example, polycarbonate
MAKROLON.RTM.3105 from Bayer Plastics is a preferred polycarbonate
to use in this invention. Other transparent polycarbonate materials
include, for example LEXAN.RTM. polycarbonate which can be
purchased from General Electric. Also, copolymers of polycarbonates
with polyesters may be used.
[0042] The decorative image layer preferably includes fabric,
metallic wire, rod and/or bar, papers or photographic images,
crushed glass, and vegetation, such as wood chips, grasses,
flowers, wheat, and thatch. The decorative image layer may display
images or decorative designs or may be of a solid color. The
melting point of the decorative image layer should be sufficiently
high to avoid any degradation or distortion of the decorative image
layer during the manufacture or processing of the decorative
laminate structure of this invention. Preferably, the decorative
image layers embedded within the decorative laminate structure of
the present invention are substantially continuous and constitute a
distinct image layer or laminate, as in FIG. 3B. Alternatively, the
decorative image layers embedded within the decorative laminate
structure can be made of discontinuous segments, for example as
illustrated in FIGS. 3A, C and D.
[0043] The decorative image layer preferably ranges from about
0.0254 mm (0.001 inch) to about 1.524 mm (0.06 inch) in thickness,
and more preferably 0.0254 mm (0.001 inch) to 0.05 mm (0.002 inch),
and most preferably about 0.04 mm (0.0015 inch) in thickness.
However, polymeric films thinner or thicker may be used in the
decorative image layer depending on the equipment available, and
under such conditions the thickness is limited only by
functionality.
[0044] In a preferred embodiment of the present invention, the
decorative laminate structure includes at least one first
decorative image layer embedded between the first and the second
polycarbonate sheet and at least one second decorative image layer
embedded between the second and the third polycarbonate sheet.
Furthermore, the first and third sheets are not necessarily the
outermost sheets of the decorative laminate structure according to
the invention. Therefore, the decorative laminate structure may
contain multiple sheet layers on each side of the decorative image
layer as well as multiple decorative image layers.
[0045] In one embodiment of the present invention, the decorative
image layer comprises a fabric comprised of textile fibers. The
fabric may display images or decorative designs which have been
produced, e.g., by weaving or knitting techniques, in the fabric.
The fabrics, which may be used in producing the decorative laminate
structures of the present invention, comprise textile fibers, i.e.,
fibers of natural-occurring, semi-synthetic or synthetic polymeric
materials. For example, the fabrics may be prepared from cotton,
wool, silk, rayon (regenerated cellulose), polyester such as
polyethylene terephthalate, synthetic polyamides such as nylon 66
and nylon 6, acrylic, modacrylic, and cellulose acetate fibers. The
melting point of the textile fibers should be sufficiently high to
avoid any degradation or distortion of the fabric during the
manufacture or processing of the decorative laminate structures of
this invention.
[0046] The fabric may be woven, spun-bonded, knitted, or prepared
by other processes well known in the textile trade and may be
uncolored, e.g., white, or colored by conventional dyeing and
printing techniques. Alternatively, the fabrics may be produced
from dyed yarn or from filaments and yarn derived from mass colored
polymers. Preferably, the fabrics present within the decorative
laminate structure are substantially continuous and constitute a
distinct image layer or laminate.
[0047] In one embodiment of this invention, the decorative laminate
structure comprising a decorative image layer comprising a fabric
can be used in the manufacture of decorative walls, partitions, and
glazing applications.
[0048] In another embodiment, the decorative image layer comprises
metallic wire, rod, or bar. The metal wire may be formed by a
variety of techniques to produce metal mesh fabric, screens, or
open mesh having high transparency. The metal wire, rod or bar may
be woven, welded, knitted, or fabricated by means of other
processes well known in the metal wire fabrication trade. The
metallic wire, rod and bar may be of various colors such as black,
gray, green, blue, etc. The metallic element of the decorative
image layer can be composed of different metallic materials such
copper, aluminum, stainless steel, steel, galvanized steel,
titanium, etc. or combinations thereof. The metallic component of
the decorative image layer may be prepared from wire filaments,
rods and bars having various cross-sectional areas and geometries,
e.g., generally circular, oval or relatively flat. The thickness or
diameter of the wire, rod and bar may range from about 0.001 to 19
mm (0.00004 to 0.75 inch) depending upon the desired use of the
thermoplastic structure. Preferably, the thickness or diameter of
the wire, rod, or bar will be in the range of about 0.0254 to 5.08
mm (0.001 to 0.20 inch).
[0049] In one embodiment of this invention, the decorative laminate
structure comprising a decorative image layer including wire, rod,
or bar can be used in the manufacture of decorative walls,
partitions, and security glazing applications.
[0050] In further embodiment, the decorative image layer comprises
a printed or colored image. Preferably, the printed or colored
decorative image layer has opposed surfaces wherein an image is
printed on one of the surfaces and/or the decorative image layer
contains coloration. More than one printed or colored decorative
image layer may be used in the decorative laminate structure of the
present invention. The use of multiple decorative image layers can
provide a 3-dimensional or "floating" appearance to the decorative
images or lettering in the printed or colored decorative image
layers. Each of the printed or colored decorative image layers is
joined to a first sheet on one of its surfaces such that the image
or coloration can be seen through the first sheet without
significant distortion. The printed or colored decorative image
layer may comprise any suitable polymeric material which is
compatible with the materials used for the first sheet and the
second sheet, inks, and other materials used in fabricating the
decorative laminate structure. Preferably, the decorative image
layer comprises a polyvinyl chloride (PVC) or copolyester.
[0051] In another embodiment, the image or coloration is printed on
the bottom side of the decorative image layer in which case the
polymer used to prepare the decorative image layer should be
transparent. Any image may be used provided it has an aesthetically
desirable surface appearance such as an image of a natural building
material. As used herein the term "building material" means a
material of suitable strength, durability, impact resistance, and
rigidity such that it can be used in construction of articles that
could also be constructed of natural building materials such as,
but not limited to, wood or stone.
[0052] The image to be printed on the decorative image layer can be
prepared according to conventional photographic printing processes
or with a digitized database generated from a photographic image-.
Digitizing and storing the image may be accomplished through any of
a number of processes well known in the computer art such as
scanning.
[0053] Printing a selected image on the decorative image layer may
be accomplished by engraving one or more cylinders, and using such
cylinders to print the selected engraved image on the decorative
image layer with appropriate ink, according to processes well known
in the printing art. The resolution of the printing method should
be in the range of about 30-59 dots per linear cm (75-150 dots per
linear inch), i.e. about 872 cm.sup.2-3,488 cm.sup.2 (5,625-22,500
dots per square inch). An illustrative example of how this printing
process can be used for bottom printing a wood grain image on the
bottom surface of the decorative image layer comprises using a
first cylinder for first printing a pattern of black or other dark
colored ink corresponding to the most prominent and most widely
spaced grain lines, i.e. coarse grain. A second cylinder may then
be used for printing smaller, more closely spaced grain lines, i.e.
fine grain, using black or other dark colored ink.
[0054] A third cylinder may be used for printing colored bands on
the decorative image layer. For example, bands about 3.8 cm (1.5
inch) wide and spaced apart by about 3.8 cm (1.5 inch) are printed
in a selected brown color. These bands give the effect of color
variations within the wood, and the widths, spacing, and color of
such bands are all selectable. A fourth cylinder may be used for
printing a relatively solid background color of a selected shade of
brown or other color corresponding to the color of the type of wood
being simulated. Also, additional cylinders may be used to provide
even more image effects in the printed or colored decorative image
layer. It is considered that a person of ordinary skill in the art
could select more or fewer cylinders and printing steps to prepare
a selected image.
[0055] These steps would be reversed for top printing an image on
the top surface of the printed or colored decorative image layer,
i.e. the solid color would be printed first followed in succession
by printing of the bands, fine grain, and coarse grain. Typically,
there is some stretching of the decorative image layer during
printing. Therefore, the second cylinder should be slightly larger
than the first cylinder, the third slightly larger than the second,
and the fourth slightly larger than the third, so that the image
printed with each cylinder is in proper register.
[0056] The ink used in the printing is preferably a solvent-based
ink with no wax which is critical to producing a durable decorative
laminate structure that is resistant to delamination. During
bonding together of the sheets and decorative image layers of the
decorative laminate structure, the layers of ink should bond with
any adjacent decorative image layers as well as to the polymer used
to prepare the printed or colored decorative image layer and second
sheet (for bottom printing) or first sheet (for top printing). A
particularly preferred solvent-based ink comprises about 20-70% of
a solvent, about 5-50% of a pigment, a vinyl acetate polymer and
formulation aids, and is available from American Mirrex.
[0057] The decorative image layer may also be colored throughout
its thickness by inclusion of pigments or colorants therein during
its manufacture and this colored image may be used as is without
printing thereon, or the colored image may be used as background
for further printing of images thereon which may be seen through
the first sheet of the structure.
[0058] In yet another embodiment, the decorative image layer
comprises vegetation, such as wood chips, grasses, thatch, flowers,
for example rose petals, wheat, grains, natural papers and others,
such that the natural color of vegetation is preserved. More than
one decorative image layer comprising vegetation may be used in the
decorative laminate structure of the present invention. The use of
multiple decorative image layers can provide a 3-dimensional or
"floating" appearance to the decorative vegetation in the
decorative image layers. Each of the decorative image layers is
joined to a first sheet on one of its surfaces such that the
vegetation can be seen through the first sheet without significant
distortion.
[0059] In further embodiment, the decorative image layer comprises
crushed glass, which may be of various colors, such as black, gray,
green, blue, orange, etc. More than one decorative image layer
comprising crushed glass may be used in the decorative laminate
structure of the present invention. The use of multiple decorative
image layers can provide a 3-dimensional or "floating" appearance
to the decorative crushed glass in the decorative image layers.
[0060] The second sheet comprising polycarbonate may be either
transparent or opaque. Hence, the second sheet may be comprised of
a high percentage of recycled resin material, which do not
necessarily retain transparency or even contain materials that
further enhance or modify the properties of the finished decorative
laminate structure. However, the first sheet and the second sheet
are preferably thermally compatible. As used herein, "thermal
compatible" means that when sheet layers of the decorative laminate
structure are bonded together under conditions of elevated
temperature and pressure, the sheets undergo approximately equal
thermal expansion or contraction such that the surface of the
decorative laminate structure is substantially planar and
interfacial stresses are minimized when the product is
thermoformed.
[0061] The second sheet should exhibit good impact resistance,
strength, and compatibility with the decorative image layer. The
thickness of the second sheet is between 0.13 and 12.7 mm
(0.005-0.5 inch), preferably between 0.74 and 10 mm (0.03-0.5
inch), more preferably in the range between 1.48 and 6.35 mm
(0.063-0.126 inch), and most preferably in the range between 2.22
to 6.35 mm. The thickness is limited only by functionality.
[0062] The decorative laminate structure preferably further
comprises a protective layer, which is a transparent, hard,
scratch-resistant or abrasion resistant coating or layer laminated
to the top surface of the first sheet. These coatings or layers
also increase the chemical resistance of the decorative laminate
structure and provide an anti-graffiti surface. For example,
polycarbonate is not as hard or scratch resistant as may be
desirable for certain applications. Thus, for an application where
the exterior surface might be subjected to being scratched, it may
be advantageous to provide a protective layer over the exterior
surface. The protective layer may be a bilayer film comprising a
protective layer on top of a sheet layer. The protective layer is
preferably selected from the UV-cured or electron-beam-cured
crosslinked acrylic, vacuum-cured or UV-cured urethane, UV-cured or
electron-beam-cured silicon with acrylic or heat cured urethane or
plastisol. A layer of polyurethane may be applied over the exterior
surface to provide abrasion resistance. Alternatively, a biaxially
oriented polyethylene terephthalate, such as MYLAR.RTM., or teflon,
such as TEDLAR.RTM., both available from DuPont Chemical Company,
may be laminated to the top surface of the first sheet as a
protective layer. More preferably, the protective layer comprises a
UV-cured or electron-beam-cured silicon to achieve glass
appearance.
[0063] In one embodiment, a method of making a decorative laminate
structure preferably includes providing a first sheet and a second
sheet, both comprising polycarbonate, providing at least one a
decorative image layer between the first and second sheet, and
heating and pressing the first and second sheet with the decorative
image layer there-between for a time, temperature and pressure
sufficient to cause the sheet layers of the decorative laminate
structure to become tacky and bond to each other. However,
temperatures which cause decomposition, distortion, or other
undesirable effects in the finished decorative laminate structure
or sheet material should be avoided. Preferably, pressing of the
first and second sheet with the decorative image layer
there-between occurs before the application of heat.
[0064] In the laminating method according to this invention, a
plywood laminating press, such as one from Onsrud Berthelsen, which
has been modified to increase efficiency of platens heat transfer
and to maximize the number of channels, is preferably used. The
increased number of channels allows to evenly distribute the
temperature over the entire decorative laminate structure. Also,
the laminating press used in the process of making the decorative
laminate structure of the present invention has electronic controls
and feedback mechanisms to allow for a precise control of the
temperature and pressure of the press.
[0065] Furthermore, in the laminating press, a metal plate which is
preferably a steel or aluminum plate having a thickness of 2 mm, a
pressure pad to help equalize pressure which is preferably a
compressible fabric pad, and a further flexible metal plate which
is preferably a flexible aluminum plate of 1.5-4 mm, are
respectively aligned in parallel pressing relation, upon the
exterior surface of the first sheet, or protective layer if
present. The fabric pad is preferably prepared from copper,
silicone, NOMEX.RTM., which is an aramid fiber or fabric available
from DuPont de Nemours, E. I. & Company, or a combination of
copper and/or silicone and/or NOMEX.RTM.
[0066] More preferably, cast paper or embossing paper is disposed
between the metal plate and exterior surface of the first sheet or
protective layer to provide a texture to the laminate structure
and/or to prevent the first polycarbonate sheet or protective layer
from sticking to the metal plate. Examples of cast paper or
embossing paper include patent paper (which provides high gloss),
patina (which provides a satin finish), matte, stucco, ostrich,
reptilian, glitter, topaz, grid, and allegro (which provides a
leather appearance). A particularly preferred cast paper is
available as ULTRACAST.RTM. from Sappi. In some instances, a
protective coat is not necessary because a heavily textured surface
may not display scratch marks.
[0067] In one embodiment, sufficient heat and pressure may be
provided to effect a bond between the sheet layers of the laminate
structure in the absence of a press, employing instead the weight
of the superposed sheet layers in conjunction with application of
heat. To augment the reduction in pressure, a vacuum may be applied
in order to remove trapped air between the adjacent sheet layers
and the decorative image layers of the decorative laminate
structure. During the bonding process, if necessary, the
polycarbonate materials may be bonded or fused together without the
use of adhesive.
[0068] Preferably, the laminating method comprises hot press
bonding and cold press bonding. Hot press bonding methods include,
but are not limited to, hot steam, electric heat, hot oil heated
and other methods know in the art. Cold press bonding methods
include, but are not limited to, cold water, glycol cooled method,
and other cooling methods well known in the art. Hot press bonding
is conducted at a temperature of about 193.degree. C. to about
249.degree. C. (about 380.degree. F. to about 480.degree. F.),
preferably in the range of about 210.degree. C. to about
227.degree. C. (about 410.degree. F. to about 440.degree. F.). The
pressures utilized in the bonding or laminating method are about
138 to 2069 kPa (about 20 to about 300 pounds per square inch,
psi), and preferably are in the range of about 448 and 662 kPa (65
to about 96 psi). The decorative laminate is held at the
appropriate maximum temperature and pressure for a period of time
of about 0.1 to about 20 minutes, preferably a period of time of
about 0.1 to 5 minutes, most preferably for a period of time of
about 0.17 minute (about 10 seconds). The optimal temperature for
bonding may vary depending on the thickness of the sheet materials
used, and may be determined by those of ordinary skill in the art.
A temperature exceeding 249.degree. C. (480.degree. F.) and a
pressure exceeding 2070 kPa (300 psi) is undesirable in hot press
bonding since the sheet layers may squeeze out of the aligned
decorative laminate structure.
[0069] This operation can be performed either with or without a
vacuum press. Generally, the occurrence of bubbles in the final
thermoplastic article produced is less likely to occur if the air
is evacuated prior to applying heat and pressure. The pressure on
the decorative laminate structure is increased to between 138 to
2069 kPa (about 20 to about 300 psi), preferably to between 448 to
662 kPa (65 to 96 psi), with a pressure of 634 kPa (92 psi) being
most preferred. As a result of pressure and heat, the sheets of
polycarbonate are fused together and the decorative image layer is
embedded or encapsulated within the polycarbonate sheets.
[0070] Following the hot press bonding, the bonded structure is
allowed to cool by being held rigid at a temperature of about 10 to
about 149.degree. C. (50.degree. F. to about 300.degree. F.),
preferably 21.1 to 32.2.degree. C. (70.degree. F. to 90.degree. F.)
and a pressure of about 7 to 2069 kPa (about 1 to about 300 psi),
preferably pressures of about 448 to 662 kPa (65 to about 96 psi),
more preferably pressures of about 552 to 662 kPa (80 to 96 psi),
most preferably about 634 kPa (92 psi) until it cools below the
glass transition temperature of the sheet material.
[0071] Lamination may be conducted using individual relatively
short sheets of overlaid material or using elongated sheets for
later width wise separation. The material is preferably laminated
in a stationary press, however, the material may be laminated using
continuous casting equipment of the type used in the plastics
industry for producing laminate web material such as a machine
employing upper and lower continuous belts. At least one of the
belts is generally heated and the decorative laminate structure is
fed into the space between the belts for movement with the belts
while being heated and pressed.
[0072] Once the decorative laminate structure is cooled below the
glass transition temperature of the polycarbonate, it may be shaped
and formed into a variety of useful articles by thermoforming or
other known methods such as extrusion or injection molding. For
example, the thermoplastic article can be thermoformed or otherwise
shaped into privacy partitions, shower surrounds, table tops, or
other uses. The thermoplastic articles of this invention can be
formed and molded without substantially distorting the decorative
image layer contained therein.
[0073] In addition to illustrative articles which include counter
tops, table tops, cabinet doors, game boards, juvenile products,
toys, panels for shower stalls, hot tubs, markerboards, indoor and
outdoor signs, seamless vanity tops including sink, soap dish, and
back splash, the decorative laminate structure can be used in
automotive, for example as a dashboard, marine, lighting, and
aerospace products. For further example, parts of a commercial
aircraft interior can be readily formed from the decorative
laminate sheets and include door linings and window bezels, door
handle escutcheons, emergency route indicator strips, instrument
panels, etc.
[0074] While the invention has been described with particular
reference to certain embodiments thereof, it will be understood
that changes and modifications may be made which are within the
skill of the art. The present invention is limited only by the
claims that follow.
EXAMPLES
[0075] The following examples are presented to illustrate the
invention and should not be construed to limit the scope of the
invention.
Example 1
Production of 1/8" Normally Thick Product Encapsulating a
Textile
[0076] To obtain the desired laminate including uniform aqua
colored textile with patina finish on both sides and flat texture,
the laminating process was performed as follows. First the hot
press platen was preheated to a temperature of 475.degree. F. The
cold press platen temperature was set at 65.degree. F.
[0077] Next the materials were assembled from top to bottom as
follows: steel press plate, Nomex pad (Nomex pressure distribution
pads), aluminum separation plate, release paper (patina finish
Ultra-cast release paper), 0.060" polycarbonate sheet (qty=2),
textile (sheer nylon textile), 0.060" polycarbonate sheet, release
paper, aluminum separation plate, Nomex pad, and steel press
plate.
[0078] After the assembly was completed, a thermocouple was
inserted in-between the first sheet of polycarbonate and the
textile. Next, the assembly was inserted in the hot press, the
press was closed and the pressure was increased to 94 psi. The
temperature was closely monitored until the thermocouple read
420.degree. F. Once the temperature reached the desired 420.degree.
F., the pressure was released and the press opened. Following hot
pressing, the assembly was transferred to the cold press set to
cold press platen temperature of 65.degree. F. Next, the pressure
in the cold press was increased to 94 psi. This transfer and
re-pressurizing was completed in less than 3 minutes. The
temperature was closely monitored until the thermocouple read
90.degree. F. Once the desired temperature was reached, the
decorative laminate structure was removed from the press.
[0079] As a result, the finished product was thermally fused
through the fabric layer, resulting in a monolithic structure.
Surface finishes on the top and bottom of the product were uniform
and even and the color of the fabric was uniform and even due to
full saturation by the polycarbonate resin.
Example 2
Production of 1/4" Nominally Thick Product That is Heavily
Textured
[0080] To obtain the desired laminate including slightly foggy
image layer with patina finish on the back and heavy texture (Quo
Mezzo, {fraction ({fraction (3/16)}}" deep, v-shaped profile,
sinusoidal pattern) on the front, the laminating process was
performed as follows. First the hot press platen was preheated to a
temperature of 475.degree. F. The cold press platen temperature was
set at 65.degree. F.
[0081] Next the materials were assembled from top to bottom as
follows: steel press plate, Nomex pad (Nomex pressure distribution
pads), aluminum separation plate, release paper (patina finish
Ultra-cast release paper), hard coated polycarbonate film (0.005"
thick film), oriented with hard-coat against layer, 0.118"
polycarbonate sheet (qty=2), textile (clear Glassheen textile),
0.118" polycarbonate sheet, release paper, aluminum separation
plate, Nomex pad, and steel press plate.
[0082] After the assembly was completed, a thermocouple was
inserted in-between the first sheet of polycarbonate and the
textile. Next, the assembly was inserted in the hot press, the
press was closed and the pressure was increased to 94 psi. The
temperature was closely monitored until the thermocouple read
440.degree. F. Once the temperature reached 440.degree. F., the
pressure was released and the press opened. Next, the assembly was
removed and split between the first release paper and hard-coated
polycarbonate film. The Quo Quo Mezzo mold was placed face down
against hard-coated polycarbonate sheet. Next, the assembly was
transferred to the cold press set to cold press platen temperature
of 65.degree. F. and the pressure in the cold press was increased
to 94 psi. This transfer and re-pressurizing was completed in less
than 3 minutes. The temperature was closely monitored until the
thermocouple read 90.degree. F. Once the desired temperature was
reached, the decorative laminate structure was removed from the
press.
[0083] As a result, the finished product was thermally fused
through the fabric layer, resulting in a monolithic structure.
Surface finishes on the bottom of the product were uniform and
even. The color of the fabric was uniform and even due to full
saturation by the polycarbonate resin and the Quo Mezzo texture has
been embossed in the polycarbonate structure uniformly.
Example 3
Production of 3/8" Nominally Thick Product Encapsulating Botanical
Matter
[0084] To obtain the desired laminate structure, including
botanical matter with clear resin, flat texture, thatch reeds
embedded on multiple layers, and patina finish on both sides, the
laminating process was performed as follows.
[0085] First the hot press platen was preheated to a temperature of
475.degree. F. The cold press platen temperature was set at
65.degree. F.
[0086] Next the materials were assembled from top to bottom as
follows: steel press plate, Nomex pad (Nomex pressure distribution
pads), aluminum separation plate, release paper (patina finish
Ultra-cast release paper), 0.118" polycarbonate sheet (qty=2),
thatch (thatch reeds), 0.236" polycarbonate sheet, thatch, 0.118"
polycarbonate sheet, release paper, aluminum separation plate,
Nomex pad, and steel press plate.
[0087] After the assembly was completed, a thermocouple was
inserted in-between the first thatch and 0.236" polycarbonate
sheet. Next, the assembly was inserted in the hot press, the press
was closed and the pressure was increased to 10 psi. The
temperature was closely monitored until the thermocouple read
410.degree. F. Once the temperature reached 440.degree. F., the
pressure was increased to 30 psi. The temperature was closely
monitored until the thermocouple read 420.degree. F. and once it
reached the desired temperature the pressure was again increased to
94 psi. The temperature was closely monitored until the
thermocouple read 435.degree. F. Next, the pressure was released
and the press opened. The assembly was then transferred to the cold
press set to cold press platen temperature of 65.degree. F. and the
pressure in the cold press was increased to 94 psi. This transfer
and re-pressurizing was completed in less than 3 minutes. The
temperature was closely monitored until the thermocouple read
90.degree. F. Once the desired temperature was reached, the
decorative laminate structure was removed from the press.
[0088] As a result, the finished product was thermally fused around
and through the pieces of thatch, resulting in a monolithic
structure. The surface finishes on the top and bottom of the
product were uniform and even.
* * * * *