U.S. patent application number 10/655331 was filed with the patent office on 2004-04-15 for metallized film and decorative articles made therewith.
This patent application is currently assigned to 3M Innovative Properties Company. Invention is credited to Falaas, Dennis O., Raschke, Howard C..
Application Number | 20040071979 10/655331 |
Document ID | / |
Family ID | 22124789 |
Filed Date | 2004-04-15 |
United States Patent
Application |
20040071979 |
Kind Code |
A1 |
Falaas, Dennis O. ; et
al. |
April 15, 2004 |
Metallized film and decorative articles made therewith
Abstract
A metallized film comprises an opaque, continuous layer of metal
on an aliphatic polyurethane substrate. The polyurethane substrate
displays a glass transition temperature of about 25.degree. to
110.degree. C. and a melting temperature greater than or equal to
200.degree. C. Decorative articles can be made with the metallized
film.
Inventors: |
Falaas, Dennis O.;
(Stillwater, MN) ; Raschke, Howard C.; (Rosemont,
MN) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Assignee: |
3M Innovative Properties
Company
|
Family ID: |
22124789 |
Appl. No.: |
10/655331 |
Filed: |
September 4, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10655331 |
Sep 4, 2003 |
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09571573 |
May 15, 2000 |
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6641921 |
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09571573 |
May 15, 2000 |
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08075297 |
Jun 11, 1993 |
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6071621 |
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Current U.S.
Class: |
428/423.1 ;
428/425.8 |
Current CPC
Class: |
Y10T 428/266 20150115;
Y10T 428/24868 20150115; Y10T 428/24736 20150115; Y10T 428/31551
20150401; Y10T 428/26 20150115; Y10T 428/24876 20150115; Y10T
428/31605 20150401; Y10T 428/24851 20150115; B44C 1/14 20130101;
C23C 14/20 20130101; Y10T 428/31554 20150401 |
Class at
Publication: |
428/423.1 ;
428/425.8 |
International
Class: |
B32B 027/00; B32B
027/40 |
Claims
The embodiments for which an exclusive property or privilege is
claimed are defined as follows:
1. A metallized film comprising a continuous, opaque layer of metal
in direct contact with an aliphatic polyurethane substrate that has
a glass transition temperature of about 25.degree. to 110.degree.
C. and a melting temperature greater than or equal to 200.degree.
C.
2. A metallized film according to claim 1 wherein the metal is
selected from the group consisting of tin, chromium, nickel,
stainless steel, copper, aluminum, indium, gold, silver, and alloys
thereof.
3. A metallized film according to claim 1 wherein the polyurethane
substrate is derived from an aqueous urethane dispersion.
4. A metallized film according to claim 1 wherein the layer of
metal is visible through the polyurethane substrate.
5. A metallized film according to claim 1 wherein the polyurethane
substrate includes a crosslinking agent therefor.
6. A metallized film according to claim 1 further comprising a
primer layer on the layer of metal for improving the adhesion of
the layer of metal to a subsequent material.
7. A metallized film according to claim 1 further comprising a
color layer on the polyurethane substrate.
8. A metallized film according to claim 7 further comprising a
protective clear coat layer on the color layer.
9. A metallized film according to claim 8 further comprising a
primer layer on the layer of metal for improving the adhesion of
the layer of metal to a subsequent surface.
10. A metallized film according to claim 9 wherein the layer of
metal is visible through the protective clear coat layer, the color
layer, and the polyurethane substrate.
11. A decorative article comprising a metallized film according to
claim 1 secured to a reinforcing layer.
12. A decorative article according to claim 11 further comprising a
primer layer between the layer of metal and the reinforcing
layer.
13. A decorative article according to claim 12 further comprising
an adhesive on the reinforcing layer for attaching the decorative
article to a subsequent surface.
14. A decorative article according to claim 11 wherein the
decorative article has a highly reflective, highly polished,
mirrorlike appearance.
15. A decorative article according to claim 11 that shows no
appreciable change in appearance after 7 days in a 93.degree. C.
oven.
16. A decorative article according to claim 11 that shows no
appreciable change in appearance after 2000 hours of xenon arc
accelerated weathering exposure.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to metallized films and,
more particularly, to metallized polyurethane films. This invention
also relates to decorative articles made with such metallized
films.
[0003] 2. Description of the Related Art
[0004] Metallized films, that is, films comprising a polymeric
substrate on which has been deposited a layer of metal, are often
employed in, for example, the automotive, furniture, stationery,
interior building material, and advertising industries to provide
an aesthetic or decorative enhancement to manufactured articles.
Such films, in order to be commercially useful as decorative and
aesthetic enhancements, should possess several characteristics.
[0005] For example, the substrate layer should be highly
transparent so as not to detract from the reflective quality of the
metal layer and the overall appearance of the article. The films
should also exhibit good heat stability, especially when employed
in the construction of outdoor signs, motor vehicles and other
articles where high temperatures may be encountered. For example,
the interior of a motor vehicle on a warm, sunny day in certain
climates may experience temperatures in excess of 90.degree. C.
[0006] Flexibility is another desirable quality because flexible
films are more. readily applied to rough or uneven surfaces and
multifaceted articles having a compound geometry. In still other
applications, metallized films may be embellished with printed
messages, decorative patterns, or complementary, decorative,
transparent, colored layers. Metallized films, in order to be
commercially useful, should readily accept printing and should be
susceptible to the adhesion of further decorative layers thereto.
Such films should also possess excellent adhesion between the metal
and substrate layers. The films should be capable of being applied
in an economical manner and retain a quality appearance without
developing bubbles, wrinkles, swells or the like. Once applied, the
film, should remain durable and exhibit good resistance to a wide
variety of weathering and environmental conditions.
[0007] Metallized films that display a bright, highly polished,
highly reflective mirrorlike appearance would be especially
desirable if they could be bonded to a reinforcing layer since they
could be used to simulate conventional chrome plated components,
such as are found on motor vehicles.
[0008] Various metallized films are presently known. For example,
metallized polyester films have been commercially available for
many years.
[0009] U.S. Pat. No. 5,164,245 (Suzuki) discloses a metallized
multilayer film comprising a first substrate layer, a second
substrate layer on the first substrate layer, and a layer of metal
on the second substrate layer. The first substrate layer comprises
from 0 to about 40 parts by weight poly(vinylidine fluoride) and,
correspondingly, from 100 to about 60 parts by weight poly(methyl
methacrylate). This patent reports that metallized acrylic films
are also known.
[0010] U.S. Pat. No. 4,101,698 (Dunning et. al.) discloses a
transfer laminate having a flexible transparent or translucent
elastomeric layer (e.g., polyurethane) and a layer of metal bonded
to the elastomeric layer in separate, microscopically discontinuous
planar quantities of high reflectivity. The metal layer forms an
apparent visually continuous reflective surface.
SUMMARY OF THE INVENTION
[0011] This invention relates to metallized films that comprise an
opaque, continuous layer of metal in direct contact with an
aliphatic polyurethane substrate. The polyurethane substrate
displays a glass transition temperature of about 25 to 110.degree.
C. and a melting temperature greater than or equal to 200 .degree.
C. The metal layer may be tin, chromium, nickel, stainless steel,
copper, aluminum, indium, gold, silver, or alloys thereof.
[0012] The polyurethane substrate may be derived from an aqueous
urethane dispersion and may advantageously include a small amount
of a crosslinking agent to desirably shift or provide the the glass
transition temperature and/or to shift the melting temperature.
[0013] Other optional, though highly desired, layers that may form
a part of the metallized film include a primer for improving the
adhesion between the metal layer and a subsequent surface. The
metallized films may also include a color layer on the polyurethane
substrate and a protective clear coat layer on the color layer.
[0014] Various decorative articles including multifaceted articles
having a compound geometry may be made using the metallized films
of the invention. The metallized film may be placed in a
conventional vacuum forming mold and a polymeric reinforcing layer
may be added thereto. Attachment of the resulting decorative
article to a subsequent surface may be facilitated by the use of an
adhesive on the reinforcing layer.
[0015] Decorative articles made with the metallized films of the
invention simulate the appearance of conventional chrome plated
parts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention will be more fully appreciated with reference
to the following drawings in which similar reference numerals
designate like or analogous components throughout and in which:
[0017] FIG. 1 is an enlarged cross-sectional view of a metallized
film according the invention; and
[0018] FIG. 2 is an enlarged cross-sectional view of an article
incorporating a metallized film according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Turning now to the drawings, FIG. 1 is an enlarged
cross-sectional view of a metallized film 10 according to the
invention. Film 10 comprises a substrate 12 that comprises (and
more preferably consists essentially of) a polyurethane material
upon which has been deposited a continuous, opaque layer of metal
14. By "film" is meant a structure that is substantially, longer,
wider, or both longer and wider than it is thick as well as being
flexible. The polyurethane substrate should be sufficiently
transparent or translucent so as to. permit metal layer 14 to be
viewed therethrough, especially when the metal layer provides a
decorative feature.
[0020] Useful polyurethane substrates are derived from aqueous
dispersions of aliphatic urethane resins, display a glass
transition temperature of about 25.degree. to 110.degree. C., and
exhibit a melting temperature greater than or equal to 200.degree.
C. The glass transition temperature and melting temperature are
determined by thermal mechanical analysis using the test apparatus
set-up described in ASTM D1525-87, "Standard Test Method for Vicat
Softening Temperature of Plastics," although Vicat softening
temperature is not measured. More specifically, a substrate sample
approximately 2 to 3 mm thick is heated from -100.degree. C. to
250.degree. C. at a rate of 15.degree. C. per minute. A flat tipped
penetration probe (needle) having a circular cross sectional area
of 1 mm.sup.2 and loaded with 5 g is used. The glass transition
temperature is the region in which the first transition occurs in
the thermal mechanical analysis. The melting temperature is reached
when the penetration probe meets no resistance.
[0021] Examples of suitable, commercially available aqueous,
aliphatic urethane dispersions include the ZENECA NEOREZ family of
materials from ICI Chemicals, Inc. such as XR 9699, XR 9679, and XR
9603. Also useful is MILES BAYHDROL 121 from Miles, Inc.
[0022] In some situations, the addition of a small amount (e.g.,
about 2.5% or less based on the solids content of the urethane
dispersion) of a crosslinking agent may be advantageous in shifting
or providing the glass transition temperature and/or the melting
temperature of the resulting polyurethane to the desired range.
Useful crosslinking agents include diaziridines, such as NEOCRYL
CX-100, available from ICI Chemicals, Inc. Another useful additive
is a coalescing solvent such as butyl carbitol. The polyurethane
substrate may also include conventional colorants such as pigments,
dyes and inks for providing a colored or tinted appearance to the
substrate. Ultraviolet radiation stabilizers may also be
incorporated depending on the ultimate application of the
metallized film.
[0023] The polyurethane substrate typically has a thickness of
about 20 to 28 microns (.mu.m). If the substrate is too thin, it
may not readily stretch or conform to articles having a compound
shape. On the other hand, if the substrate is too thick, it may be
difficult to form.
[0024] Continuous, opaque metal layer 14 has a highly reflective,
highly polished, mirrorlike appearance. By "continuous" it is meant
that metal layer 14 forms a substantially uninterrupted layer on
the polyurethane substrate as opposed to a field of closely spaced
dots or other separate segments. By "opaque" it is meant that metal
layer 14 can not be readily seen through under normal use
conditions. A typical metal density would be about 0.03
mg/cm.sup.2. Virtually any ductile metal may be used to provide
layer 14 although tin, chromium, nickel, stainless steel, copper,
aluminum, indium, gold, silver, and alloys thereof are particularly
preferred.
[0025] Metallized film 10 may optionally include a primer layer 16
for promoting adhesion between metal layer 14 and any subsequently
provided reinforcement or backing layer, such as layer 22 shown in
FIG. 2. The primer layer may be provided by any hydroxy functional
vinyl resin (e.g., VAGH from Union Carbide Corp.), any carboxyl
functional resin (e.g., VMCH from Union Carbide Corp.), or any
amine functional resin. Polyamide primer layers are also useful
such as MACROMELT 6240 from Henkel. The primer layer is typically
about 6 to 13 .mu.m thick. Metal layer 14 is in direct contact with
the polyurethane substrate. By "direct contact" it is meant that
there are no intervening tie layers or stabilizing layers.
[0026] Other optional layers include color layer 18 which may be
supplemented with an overlying, protective clear coat layer 20.
Color layer 18 is visible though clear coat layer 20 and provides
color to film 10 by the incorporation into layer 16 of one or more
of the following color agents: pigments (organic or inorganic),
dyes, inks, mica, glass particles, glass beads, etc. A typical
composition for color layer 18 is an acrylic/vinyl resin binder
containing a pigment. Clear coat layer 20 provides abrasion
resistance and environmental weathering resistance to color layer
18 and is typically provided by a solvent-based polyurethane.
[0027] Turning now to FIG. 2, film 10 comprising polyurethane
substrate 12 and metal layer 14 is secured to a polymeric
reinforcing or backing layer 22 which is useful in providing a
decorative article 24 and the like for subsequent attachment to
various surfaces. Reinforcing or backing layer 22 may be provided a
wide variety of materials such as urethanes,
acrylonitrile-butadiene-styrenes, thermoplastic polyolefins, and
the like. In general, virtually any thermoplastic molding compound
may be used.
[0028] To facilitate the attachment of decorative article 24 to a
subsequent surface, the article may be provided with an attachment
system 26. The attachment system may be provided by, for example,
an acrylic, pressure-sensitive adhesive foam tape 28 that is
temporarily protected by a removable release liner 30, such as a
silicone treated paper or polyester film.
[0029] Metallized film 10 may be readily and easily formed. For
example, the aqueous urethane dispersion for providing polyurethane
substrate 12 may be cast onto a suitable release liner such as a
release coated polyester film. The cast urethane dispersion is then
dried to remove water. The polyurethane coated release liner is
then vapor coated to opacity with the desired metal using
conventional vapor coating techniques. Optional primer-layer 16 may
then be added, if desired, by coating, hot lamination, or the like,
depending on the nature of the primer layer.
[0030] If metalized polyurethane film 10 is to be subsequently
formed into a decorative article, the polyester release liner is
removed and the metallized film is placed in a conventional vacuum
forming mold with the metallized surface facing away from the mold
surface. Typically, the mold is heated to about 52.degree. C. and a
vacuum sufficient to enable the film to conform to the contoured
mold cavity is applied. The polyurethane substrates us d in the
invention are flexible, stretchable, and readily vacuum formed into
shapes having a compound geometry.
[0031] Optional reinforcing or backing layer 22 may be used to
backfill the mold by being deposited into the mold cavity against
the metallized surface of the film. Attachment system 26 may be
applied using, for example, heated nip rollers in the case of foam
tape. The reinforcing layer is typically oven cured followed by any
optional decorating such as the casting and curing of color layer
18 and protective clear coat 20. The resulting decorative articles
display a highly reflective, highly polished, mirrorlike
finish.
[0032] The invention will be more fully appreciated with reference
to the following non-limiting examples.
EXAMPLES 1 to 11
[0033] Examples 1 to 11 illustrate the use of different aliphatic
urethane dispersions to provide polyurethane substrate 12 as well
as the effect of including or excluding a crosslinking agent. Table
1 below indicates various commercially available aliphatic urethane
dispersions that were used in forming the polyurethane substrate
and the presence or absence of a crosslinking agent. The "%
Crosslinking Agent" refers to the percent of NEOCRYL CX-100 that
was added based on the total solids content of the urethane
dispersion. In each example, the urethane dispersion also included
10% butyl carbitol (based on the solids content of the urethane
dispersion).
[0034] The compositions of Table 1 (including butyl carbitol) were
cast onto release coated polyester films and dried for 2 minutes at
about 93.degree. C. and then for 3 minutes at about 149.degree. C.
so as to provide approximately 25 .mu.m thick polyurethane
substrates. The polyurethane substrates with the polyester film
were then placed in a DENTON Vacuum DV-515 bell jar vapor coating
machine and vapor coated to opacity with tin metal (about 0.2
mg/cm.sup.2 metal density).
[0035] After vapor coating, the polyester film was removed and the
metalized polyurethane substrate was placed in an approximately
52.degree. C. conventional vacuum forming mold and vacuum drawn
into small decorative parts having a pentagonal shape, a compound
geometry, a diameter of approximately 2.54 cm, and a thickness of
about 0.25 cm.
[0036] A reinforcing layer provided by a two-part polyurethane
casting resin that comprised equal equivalents of LEXOREZ 5901-300
polyester polyol (available from Inolex Chemical Co.) (to which was
added a trace amount of dibutyl tin dilaurate catalyst) and
DESMODUR N-100 polyisocyanate (available from Miles, Inc.) was
poured into the mold cavity and in contact with the layer of tin
metal. An acrylic pressure sensitive adhesive foam tape was then
laminated to the reinforcing layer.
[0037] The contents of the vacuum forming mold were heated for
about 5 minutes at about 52.degree. C. to cure the reinforcing
layer. The resulting molded part was removed from the mold,
trimmed, and applied to a painted steel panel with the acrylic foam
tape.
[0038] Also shown in Table 1 are the glass transition temperature
(Tg) and the melting temperature (Tm) (as determined by the thermal
mechanical analysis procedure described more fully hereinabove),
the observed results being reported to the nearest 0.1.degree.
C.
1TABLE 1 % Cross- linking Tg Tm Example Urethane Resin Agent
(.degree. C.) (.degree. C.) 1 ZENECA NEOREZ XR 9699 1 44.1 221.6 2
ZENECA NEOREZ XR 9699 0 50.5 202.6 3 ZENECA NEOREZ XR 9679 1 106.5
214.3 4 MILES BAYHYDROL 110 0 47.9 199.1 5 MILES BAYHYDROL 121 0
N.O. 216.1 6 MILES BAYHYDROL 121 1 64.6 225.2 7 ZENECA NEOREZ XR
9603 1 25.9 219.7 8 ZENECA NEOREZ XR 9603 0 41.5 205.3 9 75% ZENECA
NEOREZ XR 9699 1 34.7 233.7 25% MILES BAYHYDROL 121 10 50% ZENECA
NEOREZ XR 9699 1 53.4 228.9 50% MILES BAYHYRDOL 121 11 25% ZENECA
NEOREZ XR 9699 1 52.6 229.6 75% MILES BAYHYRDOL 121 N.O. = Not
Observed
[0039] Upon removal from the vacuum forming mold, the parts of each
of examples 1 to 11 displayed a bright, highly reflective, highly
polished, mirrorlike appearance that simulated the look of
conventional chrome plated parts. Even after seven days in a
93.degree. C. oven and 2000 hours of accelerated xenon exposure
weathering (based on SAE J1960 Jun. 89 "Accelerated (G-26 type BH)
Exposure of Automotive Exterior Materials Using a Controlled
Irradiance Water Cooled Xenon Arc Apparatus") the parts of examples
1 to 3 and 6 to 11 did not appreciably change in appearance and
were considered weatherable. The part of example 4 turned a dull
gray color and the part made in example 5 lost a small amount of
its original bright appearance. consequently, examples 4 and 5 were
considered unacceptable.
[0040] Table 1 illustrates the benefit of providing a polyurethane
substrate having a glass transition temperature of about 25.degree.
to 110.degree. C. and a melting temperature greater than or equal
to 200.degree. C. Comparing the results obtained for examples 5 and
6 shows the beneficial effect of including a small amount of a
crosslinking agent in the polyurethane formulation. The addition of
1% of a crosslinking agent in the polyurethane formulation of
example 5 resulted in a suitable substrate (example 6). Examples 9
to 11 indicate that blends of more than one urethane dispersion
provide useful polyurethane substrates.
EXAMPLES 12 to 16
[0041] Examples 12 to 16 were prepared utilizing the procedure
described in conjunction with example 1 and further included a
primer layer on the metal layer for providing enhanced adhesion
between the metal layer and the reinforcing layer. The primer of
each example was an approximately 13 .mu.m thick precast layer of
MACROMELT 6240 polyamide that was hot laminated to the metal layer
using a pair of nip rollers heated to 121.degree. C. and a feed
rate of about 3.05 meters per minute. The metal layer was also
varied, as shown below in Table 2.
2 TABLE 2 Example Metal layer 12 Tin 13 Nickel 14 Chromium 15
Stainless Steel 16 Inconel
[0042] Upon removal from the vacuum forming mold, each part
exhibited a bright, highly reflective, highly polished, mirrorlike
appearance that simulated conventional chrome plated parts. After 7
days in a 93.degree. C. oven and 2000 hours of accelerated
weathering, none of the parts appreciably changed in appearance.
Table 2 indicates that various metals may be applied to the
polyurethane substrate so as to form a metallized film in
accordance with the invention.
EXAMPLE 17
[0043] A metallized film according to the invention was prepared by
blending ZENECA NEOREZ 9699 with 2% NEOCRYL CX-100 crosslinking
agent (based on the solids content of the urethane dispersion) and
10% butyl carbitol (based on the solids content of the urethane
dispersion), casting on a release coated polyester film, and drying
for 2 minutes at about 93.degree. C. and then for 3 minutes at
about 149.degree. C. so as to yield an approximately 20 .mu.m thick
polyurethane substrate. The polyurethane substrate was placed in a
DENTON Vacuum DV-515 bell jar vapor coating machine and was vapor
coated to opacity with tin metal. A 13 .mu.m thick MACROMELT 6240
polyamide primer layer was then hot laminated to the metal layer
using a pair of 121.degree. C. nip rollers and a 3.05 meters per
minute feed rate. The primed, vapor coated polyurethane substrate
was then removed from the polyester film and placed in a
conventional vacuum forming mold that had been heated to
approximately 54.degree. C.
[0044] A polyurethane reinforcing layer was provided by pouring
into the depression in the vacuum forming mold a mixture comprising
equal equivalents of LEXOREZ 5901-300 polyester polyol (to which
was added a trace amount of dibutyl tin dilaurate catalyst) and
DESMODUR N-100 polyisocyanate followed by the addition of an
acrylic, pressure sensitive foam adhesive tape. The reinforcing
layer was cured at about 54.degree. C. for about 5 minutes. The
resulting part exhibited a bright, highly reflective, highly
polished, mirrorlike appearance that simulated conventional chrome
plated parts. No appreciable change in appearance was observed
following 7 days in a 93.degree. C. oven.
EXAMPLE 18
[0045] 7.2 g. MONASTRAL YT-919D gold pigment (available from Ciba
Geigy, Inc.) was ball milled with 220 grams (g) of ZENECA XR9699
aliphatic urethane dispersion and 20 g butyl carbitol for 21 hours.
A small amount of this dispersion, sufficient to give a transparent
yellow color, was added to a blend of 100 g ZENECA XR-9699, 10 g
butyl carbitol, and 0.3 g Rohm & Haas TRITON GR-7M. This blend
was cast on a release coated polyester film and dried for 5 minutes
at 93.degree. C. and then for 3 minutes at 149.degree. C. to give
an approximately 25 .mu.m thick film. After vapor coating to
capacity with tin metal, the sample was primed and formed as in
example 12 to give a decorative product having a bright, highly
reflective, highly polished gold appearance. The part showed no
appreciable change in appearance after 7 days in a 93.degree. C.
oven and 2000 hours of accelerated weathering.
EXAMPLES 19 to 22
[0046] Examples 19 to 22 were prepared to evaluate the utility of
alternative substrate materials. In each case, the procedure
described in conjunction with example 17 was followed except using
a substrate material selected according to Table 3 below.
3TABLE 3 Example Substrate 19 Polyethylene terephthalate 20
Polyvinylidene fluoride 21 Polyvinyl chloride 22 Polybutylene
terephthalate
[0047] Examples 20 to 22 resulted in products having a hazy
appearance that did not simulate conventional chromed plated parts
and were considered unacceptable. Example 19, while providing a
part that simulated a conventional chrome plated part, could not be
readily formed in the vacuum mold and, as a result, was considered
unacceptable.
[0048] Numerous variations and modifications-are possible within
the scope of the foregoing specification and drawings without
departing from the spirit of the invention which is defined in the
accompanying claims.
* * * * *