Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
Field of the Inventlon
The present invention relates to a metallized decorative
film and a pracess for making it by applying the metallic film by
transfer lamination. The decorative film can be used to apply
decoration to a desired substrate, e.g., a motor vehicle.
Description of the Prior Art
Metallized decorative films whiah are suitable for exter-
ior use and which contain a substantially transparent, plasticized
film have been formed in the past by laminating the transparent
film to a vacuum metallized film, e.g., a vacuum metallized poly-
ester film, which i5 then overlaminated with a clear polyvinyl
fluoride film which aids in protecting the polyester film from
ultraviolet degradation. Such complex laminates are rather stiff
and difficult to form into complex shapes and are subject to mois-
ture degradation at the exposed edge of the lamination between the
polyvinyl fluoride film and the polyester film.
Direct vacuum metallization of a flexible plastic film is
difficult to accomplish since various ingredients in the film tend
to "gas off" during the metallization process interfering with both
the maintenancè of the vacuum and the uniformity of the metal de-
posit. One solution to this problem has been the suggestion that
a barrier layer of a long chain thermoplastic polyvinyl resin
containing a large number of highly polar groups be placed over
the plasticized resin and that this layer be metallized and then
coated with a transparent film, U.S. Patent No. 2,993,806 to E. M.
Flsher et al. Another solution which has been proposed in U.S.
Patent No. 3,107,198 to L. E. Amborski et al. is to treat the
metallized layer with a complex compound of the Werner type.
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Summary of the Invention
The present invention is a metallized decorative film lam-
inate and the process for making it. The laminate comprises: (a)
a substantially transparent plastic filml (b) a thin metallic layer
having one side attached to one side of the plastic film by means
of an adhesive layer; and (c) a pressure sensitive adhesive layer
attached to the other side of the metallic layer, said adhesive
layer being optionally covered on its exposed surface by a release
liner. The film laminate is formed by applying the metallic layer
to one side of the plastic film by transfer lamination followed by
attachment of the pressure sensitive adhesive layer and, if de-
sired, release liner to the other side of the metallic layer.
Brief Description of the Drawings
Certain preferred embodiments of the present invention are
shown in greatly enlarged cross-sectional view in the Drawings
which accompany and form a portion of this specification wherein:
Figure 1 shows the substantially transparent plastic film
to which the metallized layer is to be attached;
Figure 2 shows the plastic film/metallic layer combination
after the latter has been adhesively attached to the plastic film
by transfer lamination and as the carrier film in the transfer lam-
inate responsible for the transfer lamination step is being removed;
Figure 3 shows the laminate from Figure 2 after application
of a tie coat to the protective or release coating remaining from
the transfer laminate used in the previous step; and
Figure 4 shows a desired end product after a release liner
and pressure sensitive adhesivehavebeen attached to the tie coat
in the laminate of Figure 3.
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Description of the Preferred Embodiments
Figure 1 shows the substantially transparent plastic film
1 which may be any conventional, substantially transparent and
flexible film known to persons of ordinary skill in the art of fab-
ricating decorative pressure sensitive products. The term "sub-
stantially transparent" as used herein is intended to encompass
those plastic films which are transparent enough to allow a viewer
to perceive the decorative effect generated by the metallic layer
in the laminate of the present invention. The thickness of the
film 1 can range from about 2 mils (0.05 mm.) to about 20 mils
(0.5 mm.), and the film can be a homo- or copolymer of vinyl chlor-
ide (the preferred film material), a polyester resin, a cellulose
resin, or the like. Films of this type are well known in the art
and have been used heretofore in forming decorative laminates which
differ in construction from the present laminate.
Figure 2 shows the laminate subcombination that results
when a thin metallic layer 2 is adhesively attached to the plastic
film 1. This is accomplished by transfer laminating this layer 2
to the film 1 by means of a "metallized transfer laminate" which
is indicated generally by the reference numeral 10 in Figure 2.
Such laminates are well known but have not hiterto been used to
laminate thin metallic layers to the type of substantially trans-
parent plastic film used herein to form decorative metallized lam-
inates useful as decorative trim, for example, on such substrates
as motor vehicles, and the like. Preferred metallized transfer
laminates of this type are available under the trademark "Chromtex"
from Kurz-Hastings, Inc., Philadelphia, Pa.
The metallized transfer laminate comprises an adhesive
layer 3 attached to a thin metallic layer 2 which is bonded to a
carrier film 4, preferably by means of a protective or release
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coating 5. The metallized transfer laminate 10 is applied to the
substantially transparent film 1 in such a way so as to adhesively
bond metallic layer 2 to film 1. The carrier film 4 in the metal-
lized transfer laminate 10 is then stripped off as shown in Figure
2.
The carrier film 4 may be formed of a suitable flexible ma-
terial capable of being coated, if desired, by the resinous solu-
tion which constitutes the protective or release coating 5. Ex-
amples of suitable carrier films 4 are formed from polyethylene
10 terephthalate, crystallized copolymers of polyethylene terephthal-
ate and isophthalate, oriented polystyrene, polyvinyl fluoride,
acetate coated paper, and polyolefins, such as polyethylene and
polypropylene. The carrier film 4 can have a thickness of from
about 0.5 mil (0.013 mm.) to about 5 mils ~0.125 mm.)
The protective or release coating 5 is preferably included
in the metallized transfer laminate 10 since it aids in stripping
the carrier film 4 from the laminate construction after the metal-
lic layer 2 has been adhesively bonded to transparent film 1. The
release coating 5 may be formed by coating the carrier film 4 and
is preferably a resinous solution comprising solvents which do not
adversely affect the film 4 and an organic solute not normally
compatible therewith. Some representative release coatings in-
clude the polyurethanes, silicones, phenol formaldehyde solutions,
solvent systems of polyesters and combinations such as methyl meth-
acrylate, ethylene terephthalate, and ethylene isophthalate andwater and organic solvent systems of polyvinyl acetate and poly-
vinyl chloride. The coating used to form release layer 5 may be
uniformly applied by conventional coating techniques, such as,
direct roller coating, reverse roller coating or by flexographic
or rotogravure coating. The release coating 5, when dried, con-
stitutes a layer which, while not bonded to the carrier film 4
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in any chemical sense, superficially adheres to it.
The metallic layer 2, which is attached, prefereably to
the surface of release coating 5, may be formed of any metal sueh
as gold, silver, aluminum, magnesium, titanium, nickel, zinc,
copper, chromium, cobalt, selenium or the like. Metallic com-
pounds as well as alloys can also constitute the layer. Aluminum
or an aluminum alloy are often preferred for reasons of economy
and durability. The thickness of this layer will generally range
from about two or three millionths of an inch (about 500 to 750
Angstroms) to about fifty millionths of an inch (12,500 Angstroms).
The films may be deposited on the release coating 5 by the known
thermal evaporation or cathodic sputtering techniques as described
in U.S. Patent No. 2,993,806.
The nature of adhesive layer 3 in the metallized transfer
laminate 10 will depend upon the character of the plastic film 1
to which it will be attached. Heat activatable adhesives that are
compatible with plastic film 1 can be used and include rubber-
phenolic and polyester-isocyanate systems, polyurethane, and sol-
utions of vinyl chloride/vinyl acetate, vinyl acetate/acrylate and
vinyl aeetate/maleate copolymers. Preferably, the selected ad-
hesive will dry to a water-white clear film and remain clear even
upon outdoor exposure.
Removal of the carrier film 4 from the metallized transfer
laminate 10/plastic film 1 eombination will leave release eoating
5 exposed, if sueh a eoating is present. When such a coating is
in the transfer laminate 10 for its release properties, it may be
; neeessary to apply a resinous tie eoat 6 (as shown in Figure 3) to
the exposed surface of release coating 5 in order to provide a site
for later secure attachment of a layer of pressure sensitive adhes-
ive 7 and, if desired, a release liner 8 (as shown in Figure 4).
Tie coats which are compatible with and thus have good anchorage
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to both release coating 5 and the desired pressure sensitive ad-
hesive 7 will adequately serve the intended purpose. The tie coat
should also possess good cohesive strength so that it will not be
a site of internal failure in the final laminate. Polyurethane
tie coats having the above-described compatibilities and cohesive
strength are one representative class of tie coats that may be used.
Figure 4 in the Drawings shows a preferred and finished
laminate of the present invention wherein a layer of pressure sen-
sitive adhesive 7 and a release liner 8 have been applied to the
exposed surface of the tie coat 6.
The pressure sensitive adhesive 7 which is used in the
present laminate may also be any of the pressure sensitive adhe-
sives which are known and conventionally used in the art. As for
the applicable tacky, pressure sensitive adhesives which may be
utilized in the product of this invention, they may be based upon
any elastomeric material such as: (1) natural rubber; (2) syn-
thetic rubbers including, for example, styrene-butadiene copoly-
mers, polyisobutylene, butadiene-acrylonitrile copolymers, poly-
chloroprene, and polyisoprene; (3) acrylic copolymers containing
at least 50 percent, by weight, of a C4-C12 alkyl acrylate ester,
i.e., an alkyl acrylate es~er wherein the alkyl group contains
from 4 to 12 carbon atoms, together with a hardening comonomer,
for example, vinyl acetate, styrene, methyl methacrylate, methyl
acrylate, ethyl acrylate, ethyl methacrylate and vinyl chloride;
and (4) polymers of alkyl vinyl ethers such, for example, as poly-
methyl vinyl ether and polyethyl vinyl ether. Acrylic pressure
sensitive adhesives are most preferred since they have the best
balance of adhesive and cohesive properties for the present lamin-
ate. The thickness of the adhesive layer 7 will generally be in
the range of from about 0.5 mil (0.013 mm.) to about 2.0 mils
(0.05 mm.).
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If the laminate of the present invention is to be manufac-
tured at one location and used at another location, a release liner
8 is preferably affixed to the side of the pressure sensitive layer
7 which is furthest removed from film 1. The release liner 8 may
be any of the release liners known to persons of ordinary skill in
the art of making pressure sensitive products including removable,
water soluble protective coatings, and the like. One preferred
liner material is silicone coated release paper having a thickness
of from about 2.0 mils (0.05 mm.) to about 12 mils (0.3 mm.). Of
course, if the film/adhesive composite is to be manufactured and
applied to a desired substrate at the same manufacturing location,
a release liner may not be needed.
A preferred process for affixing the comblnation contain-
ing the film 1 and the pressure sensitive adhesive 7 and release
liner 8 comprises transfer coating. In such a process, a fluid
solution of the adhesive 7 is applied to the release liner 8, and
the resulting composite is heated to dry the adhesive layer 7.
The adhesive side of this adhesive/liner laminate is then lamin-
ated to the exposed surface of the protective layer 6 at a con-
ventional lamination nip to form the product shown in Figure 4.
When the laminate of the present invention is to be used,
the adhesive layer 7 is brought into contact with a desired sub-
strate and, whèn properly positioned, pressure is applied to se-
curely affix it to a desired substrate, e.g., a motor vehicle.
The Example which follows illustrates certain preferred
embodiments of the present invention.
EXAMPLE
This Example illustrates how one product of the present
invention was made under laboratory conditions.
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A transparent polyvinyl chloride (PVC) exterior grade film
having a thickness of about 3 mils (0 n 07 mm.) was laminated to a
release coated polyester film which had been metallized followed
by coating of the metallized surface with a clear, light stable,
heat activatable adhesive ("No. 9353 Chromtex Smooth Gold 78 with
840 adhesive", available from Kurz-Hastings, Inc., Philadelphia,
Pa.). This metallized transfer laminate was 0.8 mils (0.02 mm.)
in thickness and had its adhesive side laminated to the matte or
dull side of the PVC film by passing both films over a series of
heated drums. This raised the temperature of the heat activatable
adhesive to about 270F. (135C.) for proper activation and forma-
tion of a satisfactory bond of the metallized transfer laminate to
the PVC film. The polyester film was then removed from the trans-
fer laminate leaving a PVC film/adhesive/metal layer/release coated
intermediate structure.
In order to satisfactorily bond pressure sensitive adhes-
ive and release paper to the release coated side of the structure
resulting from the previous steps, approximately 0.2 mil (0.005 mm.)
of a polyurethane polymertiecoat was applied to the release coat-
ing. The polyurethane polymer that was used was a fully reacted
polyurethane polymer supplied as a solution in toluene and isopro-
panol (available as "Milloxane LS-516" from Millmaster Onyx).
After thetiecoat layer was allowed to dry by being heated at 70 C.
for 30 sec., a layer of about 1 mil (0.025 mm.) of pressure sensi-
tive adhesive was applied to thetiecoat layer by means of a con-
ventional transfer technique. The adhesive that was used herein
was a high molecular weight thermoplastic acrylic terpolymer, which
is available as "Durotak 80-1053" from National Starch and Chem-
ical Corp. In such a technique, the wet adhesive is coated
directly onto release paper at a thickness of about 3 mils (0.076
mm.) followed by evaporation of the solvent by heating at 100C.
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for 2 minutes. This is followed by lamination of the dried ad-
hesive to the tie coat layer by passing the adhesive/release liner
laminate and the PVC containing laminate through a laminating nip.
After lamination, a high level of adhesion was exhibited
between the layer of pressure sensitive adhesive and tie coat. The
resulting laminate is useful as a metallized film for such end
uses as automobile trim.
The above Example shows a preferred embodiment of the
present invention and should not be construed in a limiting sence.
The scope of protection that is sought is given in the claims
which follow.
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