Note: Descriptions are shown in the official language in which they were submitted.
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CIP of C-5066
Background of the Invention
Field of the Invention
The present invention is a pressure sensitive,plastic film/
flexible backing composite article useful as, for example, a
vehicle roof ma~erial, its method of application to a desired sub-
strate, and the resulting substrate/article combination.
Description of the Prior Art
Plastic film, flexible backing composite articles suitable,
for example, as a roofing material on vehicles, e.g., automobiles,
are known products. Such composite materials have other uses, for
example as padded vinyl wallcoverings,liningmaterials for automo-
bile trunks, etc., but will be described herein in connection with
their primary commercial use as a roofing material for motor
vehicles, such as automobiles.
Such composite articles when used as vehicle roof materials
have been conventionally sold to the vehicle manufacturers without
a layer of adhesive and the manufacturers would spray the exposed
side of the backing material with a solution of a contact adhesive
in the vehicle manufacturing plant and then affix the sprayed com-
posite article to the vehicle substrate which had also been
covered with the same adhesive (see U.S. Patent No. 3,935,353 to
R. G. Doerfling et al., Col. 1, lines 31~45). Contact adhesives
are adhesives which must be applied to both surfaces that are to
be bonded together. They cannot be considered to be "pressure
sensitive" adhesives as that term is employed herein. Such a
technique has a number of serious disadvantages. Spraying
of solvent based adhesives in the vehicle plant can give rise to
potentially serious environmental/safety/health problems. The
technique is rather time consuming and involves the use of greater
amounts of manpower than desired. The spraying of adhesive onto
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CIP of C-5066
the backing can also result in a non-uniform and discontinuous ad-
hesive coverage of the backing leading to formation of voids be-
tween the backing and vehicle roof which can permit corrosion
problems when the finished vehicle is placed in actual service.
An alternative to this conventional procedure is described
in U.S. Patent Nos. 3,8~6,200 and 3,935,353 to R. G. Doerfling et
al. In these patents a plastic film/flexible backing product con-
taining a layer of a non-pressure sensitive, heat activatable ad-
hesive is proposed. Such a product, although overcoming some of
the shortcomings of conventional in-plant spraying techniques also
has certain drawbacks. One of the most serious is the need for
heating means in the automobile assembly area to heat the adhesive
to its heat-activatable temperature at which tackification occurs.
This may require an additional undesirable capital investment for
the vehicle manufacturer. In addition, plastic film materiaI in
such a technique must be preformed in a press with heat prior to
application in order to insure the proper fit.
Summary of the Invention
. .
The present invention is a preSsure sensitive composite
article suitable for use, e.g., as a roofing material on vehicles,
which, when used to provide such a roofing material, overcomes the
shortcomings noted above for solvent sprayed, contact adhesive con-
structions and constructions containing a heat activatable adhesive.
It comprises a plastic film which is attached to a backing material
which has a substantially continuous and uniform coating of a pres-
sure sensitive adhesive on the side thereof which is remote from
the plastic film and, in a preferred embodiment, which also has the
exposed surface of the adhesive layer covered with a release liner
to protect this layer from contamination. The present invention
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CIP of C-5066
~- also includes a method of affixing such a laminate to a desired
substrate, e.g., a vehicle, by application of pressure only, and
it also includes the resulting substrate/composite article combin-
ation.
The composite article of the present invention, when used
` as a vehicle roof material, has the following major advantages
over the prior art use ofsprayed solvent adhesives elimination of
~; the potential environmental/safety/health hazards involved with
spraying potentially toxic solvents in the workplace; a reduction
in the time and manpower needed to apply the article to the vehi-
cle; and a greater degree of protection from corrosion
in the composite article/vehicle combination due to the presence
of a substantially continuous and uniform layer of adhesive in
the article of the present invention to provide a substantially
continuous and uniform surface for contact with the substrate.
The article of the present invention has the following
major advantages, when used as a vehicle roof material, over the
`~ use of a heat activatable adhesive such as shown in U.S. Patent
Nos. 3,846,200 and 3,935,353 to R. G. Doerfling et al.: heating
of the article after its application to a vehicle is not necessary
to affect an adhesive bond between the article and the vehicle
-~ substrate; and preforming the article in a heated press is not
needed~
Description of the Drawings
;~ .
:
~; The Drawings which form a portion of this specification may
be consulted to further understand the composite article of the
present invention wherein:
Figure 1 is an enlarged, cross-sectional view of the clos-
est known prior art article showing the discontinuous layer 6 of
., ~
. . . . . . ... . . . . .. . .
CIP of C-5066
non-pressure sensitive,contact adhesive after the adhesive has
been sprayed onto the backing 3 in a vehicle assembly plant; and
Figure 2 is an enlarged, cross-sectional view of a pre-
ferred embodiment of the present invention as release liner 8 is
being removed from the substantially continuous and uniform layer
of pressure sensitive adhesive 7 preparatory to affixing the com-
posite article to a desired substrate, e.g., a vehicle roof.
r
I Descri~tion of Preferred Embodiments of the Invention
, s_ _ _ _
The composite article of the present invention comprises
some elements which are old, namely, plastic film 1 as well as
` flexible backing 3, which is attached to film 1. A suitable ad-
hesive 2, e.g., a plastisol adhesive, can be used to attach plas-
tic film 1 to backing 3, if desired, and this adhesive layer is
also sometimes used in film l/backing 3 articles known to the prior
art. Any person of ordinary skill in the art would be able to
select appropriate materials for making such a film/backing sub-
combination ~optionally joined with adhesive) from the description
which follows.
The plastic film 1 may be formed of any thermoplastic or
thermosetting synthetic polymer which, preferably, is resistant
to weathering and ultraviolet light so as to provide a long, use-
ful life for the composite article should it be intended to be
affixed to a vehicle and used as a roofing material. Representa-
tive plastic film materials include the ~;inyl and vinylidene,
acrylic, urethane, polyester, fluorocarbon, and polyolefin poly-
mers and compatible blends thereof. Vinyl chloride polymers are
l.i
economically preferred. Preferred vinyl chloride polymers may
,
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CIP of C-5066
be any of the conventional polyvinyl chloride resins that have
been hithertoused in such applications in formulation with any
desired and suitable plasticizers, fillers, stabilizers, pigments,
fungicides, process aids, and the like. If desired, internally
plasticized vinyl chloride polymers may be used instead of the
combination of conventional vinyl chloride polymers and external
plasticizers. The thickness of this plastic film will generally
range from about 5 mils (0.13 mm.) to about 25 mils (0.7 mm.) al-
though thinner as well as thicker films can be used, if desired.
The film can be formed by any fabrication technique known to the
art and is generally embossed with a suitable decorative pattern.
It may be covered with a thin protective polymeric topcoat (not
shown), such as a urethane, acrylic or vinyl polymer or compatible
blends thereof, to protect it from degradation due to mechanical,
chemical and environmental factors.
The film 1 is attached to a backing which is broadly in-
:, .
dicated by reference numeral 3 in the Figures. The attachment of
:,
backing 3 to film 1 can be made by means of a thin adhesive layer
2 or the film 1 can be directly attached to the backing 3 (e.g.~
by extrusion or calendering of hot plastic film 1 onto the back-
ing 3) so that the attachment is made without the need for an
intermediate adhesive layer.
The backing 3 can be selected from a wide variety of back-
ing materials, such as non-woven, woven, knit, or composite mater-
lals (non-woven/foam combinations, non-woven/knit combinations,
non-woven/woven/knit combinations, etc.) to provide a sufficient-
ly thick layer which will aid in camouflaging any surface irreg-
ularities that may exist on the substrate, e.g., vehicle roof,
when the composite article is in position on the substrate. The
term "backing" as used herein is to be construed as relating to
~ such backing materials which are well known in the art of making
,.
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CIP of C-5066
film/backing composite articles which are useful, for example,
as exterior roofing materials for vehicles. Generally the weight
of the backing material will range from about 2 to about 20 oz/yd2
, (68-680 gm./m2) and its density from about 2 to about 20 lbs/ft3
(32-320 kg/m3). The thickness of the backing and film composite
will generally range from about 20 to about 200 mlls (0.5 - 5.1
mm.), preferably from about 55 mils (1.4 mm.) to about 85 mils
(2.2 mm.).
A preferred backing material for reasons of improved
tailorability of the finished product are the commercially avail-
able backings of a non-woven fabrlc of synthetic fibers which have
~ been needle punched into a thin layer of foam. Some preferred ex-
; amples of fibers which can be used in such a backing include: poly-
propylene, rayon, polyester, acrylonitrile, nylon, polyphenylene
~5 sulfide, and mixtures thereof. Suitable foam materials which can
be used include urethane and polyvinyl chloride foams. The denier
~; of such fibers in this type of backing can range from about 1 to
about 20. "Denier" is defined as a unit of fineness equal to the
fineness of a yarn weighing one gram for each 9000 meters. The
"
foam in such a backing can have a thickness of from about 10 mils
(0.25 mm.~ to about 150 mils (2.5 mm.)
The backing 3 is preferably made water repellent by treat-
ment with an effective amount of at least one water repellent agent
when the composite article of the present invention is to have an
; ,
25 ~ exterior use, e.g., as a vehicle roof material. Fluorocarbon
, . . .
emulsions, which are available under the trademarks "Zepel" (from
; E. I. DuPont de Nemours Co.) or "Scotchguard" (from 3M Co.), are
representative types of materials which can be used to confer such
water repellency. In order to treat the selected type of backing
material, it can, for example, be placed in a fluorocarbon bath,
dried, and the resulting product can be cured. The product that
results from either this or alternative treating procedures will
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CIP of C-5066
resist being wetted by water, oil and other contaminants. Further
information on how backing 3 might be rendered water repellent can
be ascertained from "Waterproofing and Water Repellency", Kirk~
Othmer Encyclopedia of Chemical Technology, 2nd Edition, Vol. 22,
pp. 135-156 (1970).
If desired, one or more corrosion inhibitors can be used
to treat the backing 3,if the article is to have exterior uses,in
order to confer or enhance corrosion protection on the article/
substrate combination. The corrosion inhibitor can be any compat-
ibleinhibitor and can be applied in conjunction with the afore-
mentioned water repellent agent. For example, when a fluorocarbon
bath treatment is employed, suchknown corrosion inhibitors as the
nitrites, phosphates, chromates and sulfates might be present in
the bath to act as a corrosion inhibitor when the article is sub-
jected to exterior use for the final article/substrate combination
that will be produced. One corrosion inhibitor which is preferred
for economic reasons is sodium nitrite. Further information on
how the backing 3 might be treated to render the article/substrate
combination corrosion resistant can be ascertained from "Corrosion
Inhibitors", Kirk-Othmer Encyclopedia of Chemical Technology, 2nd
Edition, Vol. 6, pp. 317-346 (1965).
The composite article of film 1 and backing 3 which is
known to the prior art can be formed by a number of well-known
processes such as direct calender lamination or extrusion coating,
post lamination or casting.
Direct calender lamination or extrusion coating produce a
composite article without the use of adhesive layer 2. The plastic
film 1 acts as the adhesive because it is brought in contact with
the backing 3 shortly after formation while the film 1 is still
~30 hot and sticky.
CIP of C-5066
Post lamination is another well known method and differs
from the extrusion coating or direct calender lamination tech-
niques in that the plastic film 1 is not usually formed just prior
to the bonding step and an adhesive layer 2 is applied directly by
known coating techniques (gravure cylinder, knife, roller, reverse
roller, etc.) to the film before the film is contacted with the
backing 3. A roll of preformed film is generally the source of
the film, and a thin layer of adhesive is applied to the side of
the film which is to be bonded to the backing. The adhesive is
applied by a suitable means usually in an amount in the range of
from about 1 to about 5 oz./yd. 2 (34 to 170 g/m2) depending upon
the adhesive. The coated film then is contacted with the backing
to form the composite article known to the prior art.
Adhesives suitable for use in the post lamination technique
are well known in the art. Some examples include plastisol, epoxy,
acrylic, and urethane adhesives~ Plastisols are one of the best
known materials. These are dispersions of finely divided polymer-
ic materials in nonvolatile organic liquids and low melting solids,
generally referred to as plasticizers. Suitable plasticizers in-
clude phthalate, adipate and sebaccate esters and polyols such as
ethylene glycol and its derivatives. A typical plastisol composi-
tion is 50 parts polymeric material and 50 parts plasticizer,
forming a paste which gels, and fuses when heated to about 300F.
as a result of solvation of the resin particles by the plasticizer.
If a volatile solvent is included in the plastisol, then the ad-
hesive generally is referred to as an organosol which also is suit-
able for use in the invention.
In order to form the final pressure sensitive, composite
article of the present invention, the exposed side of backing 3
is coated with a substantially continuous layer 7 of a suitable
tacky, pressure sensitive adhesive. Pressure sensitive adhesives
C-5066
are a well know~ class of adhesives and develop maximum adhesive
bondingwith the application of pressure alone. Preferred adhesives
of this class are those which exhibit good adhesion and, when the
article is to be used in exterior applications, outdoor durability.
.S Self crosslinking thermosetting acrylic pressure sensitive adhes-
ives are one preferred class which can be used in the forming of
the laminate of the present invention. Illustrative U.S. patents
describing adhesives of this type are U.S. Patent Nos. 3,269,994,
3,579,49n and 4~005~247O Preferred formulations are available
under the trademarks "Aroset 1085'1 ~Ashland Chemical Company),
"Bostik 7525" (~SM Corp.) and "D~-7025 (Daubert Chemical Co.).
These adhesives have, moreover, shown to have especially
good compatibility to backings containing the water repellent
and/or corrosion inhibitor agents described above. The thickness
of the adhesive layer in the composite article of the present in-
vention can range from about 0.5 mil (0.01 mm.) to about 10 mils
(0.25 mm.). The layer is deposited on backing 3 so that it forms
, .
a substantially continuous coating which is also substantially
free of voids, channels and the like. The presenceof such a layer
affords a barrier between the substrate and the atmosphere to
''!,~ moisture and other environmental factors which are prone to cause
corrosion when the article is used in exterior applications in
the substrate/article combination.
The composite article of the present invention can find
utility without the presence of release liner 8, for example, if
it is used shortly after application of the adhesive layer, and
care is taken to avoid contamination of the exposed surface of the
.,;
adhesive layer 7 with foreign matter. If this embodiment of the
invention is desired, the adhesive in the form of a viscous fluid
can be cast onto the backing 3 and dried by the application of heat.
In most end uses however, the composite article will be manufac-
tured with a suitable release liner 8 by a manufacturer,and the
product will be sent to a customer for use.
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CIP of C-5066
The release liner 8 may be any of the release liners known
to persons of ordinary skill in the art of making pressure sensi-
tive products including removable, water soluble protective coat-
ings, and the like. One preferred liner material is silicone
coated release paper having a thickness of from about 2 mils
(0.05 mm.) to about 10 mils (0.25 mm.) Polyolefinic (e.g. ethyl-
ene), ethylene/vinyl acetate copolymer, ethylene/acrylic copolymer,
and ethylene/chlorinated polyethylene blends which have been
suitably release coated, e.g., with a silicone release agent, may
also be employed as release liners.
A preferred process for affixing the film l/backing 3
combination and the pressure sensitive adhesive 7 and release lin-
er 8 comprises transfer lamination. In such a process a solvent
solution, aqueous dispersion or hot melt of the adhesive 7 is
applied to the release liner 8, and the resulting composite (ex-
cept when a hot melt technique is used) is heated to dry the ad-
; hesive layer 1. The adhesive side of this adhesive/liner laminatèis then laminated to the exposed surface of the backing 3, pref-
~ erably at a heated lamination nlp, to form the product shown in
Figure 2. The use of a heated nip insures good bonding betweenthe adhesive layer 7 and the backing 3 which may have been treated
with water repellents and/or corrosion inhibitors
Besides transfer lamination, the adhesive can be applied
to the backing by use of conventional direct application methods
using either knife, roller, reverse roller or extrusion coating
techniques provided a substantially continuous and uniform coat-
ing of pressure sensitive adhesive results.
When the composite article of the present invention is to
-be used, the adhe~sive layer 7 is brought into contact with the
vehicle substrate and, when properly positioned~ pressure is
applied to securely affix it to the vehicle. This process is
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CIP of C-5066
performed in the absence of spraying solvent based adhesives or
`heating the laminate/vehicle substrate combination.
The Examples which follow illustrate certain preferred em-
bodiments of the present invention.
EXAMPLE 1
~; This Example illustrates how one preferred composite
article in accordance with the present invention was made.
'; ;10 The first step ln forming the desired product was calen-
dering at a temperature of about 335 C. a film formulation con-
taining the following ingredients to a thickness of about 14.5
mils (0.36 mm.):
Ingredient Percent by Weight
, 15 Polyvinyl Chloride Homo-
polymer Resin..................... 47.745
Calcium carbonate filler........... ~14.328
, Normal alkyl phthalate
plasticizer....................... 31.194
Fungicide/Plasticizer-
Stabilizer......................... 1.197
Epoxidized
Soya Oil~ 2~385
; Colloidal Silica..................... 0.477
Heat sta~ilizer (Metallic
soap)........~..................... 0.100
Pigment............................ .. 0.900
Barium/Cadmium/Zinc
Stabilizer....................... .. I.197
Liquid Phosphite
^ Stabilizer....................... .. 0.477
To the calendered film was then applied via a roller knife
technique a polymeric solution topcoat at a rate of 0.105 lbs/yd2
(0~57 kg/m2). The volatile solvent in the topcoat solution was
flashed off in a drying oven at a tempera~ure of about 160F.
(71.1C.) and recovered without release to the environment. The
following ingredients formed the topcoat:
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CIP of C-5066
Ingredient Percent bv Weight
Methyl ethyl ketone................ 89.11
PVC Homopolymer Resin.............. 7.61
Acrylic Resin...................... 2.70
Colloidal Silica................... 0.58
The topcoated vinyl film was then laminated to a non-woven
substrate with a plastisol adhesive and was in-line embossed with
a decorative grain at a temperature of about 320F. (160C.) which
also cured the plastisol adhesive. The non-woven substrate was an
all-polyester blend of 60%, by weight, 3 denier, 4 inch (10.2 cm.)
staple fibers; 20%, by weight, 6 denier, 3 inch (7.6 cm.) staple
fibers; and 20% by weight, 6 denier, 6 inch (15.2 cm.) staple
fibers; which had been needle punched into a polyester urethane
foam having a thickness of 30 mils (0.8 cm.) and a density of 2.0
lbs/ft3 (32 kg/m3). The composite non-woven/foam construction had
s been fluorocarbon treated. It is a commercially available product
;- 15
from Foss Manufacturing and had a weight of 6.5 oz/sq. yd.
(0.22 kg/m2). The 30 mils (0.8 cm.) of foam was primarily on the
one side of the substrate, and it was this side which was lamin-
; ated to the vinyl film.
The pressure sensitive adhesive formulatior comprised
these ingredients:
Ingredient Percent by Weight
Self-Crosslinkable Acrylic
Pressure Sensitive Adhesive
Solution ("Aroset 1085").......... 77.77
Ethyl acetate solvent............... 16.67
Toluene Solvent..................... 5.56
The composition was reverse roll coated at 0.3 lbs/yd2
(0.16 kg/m~) onto 94 lbs/ream (43 kg/ream), polyethylene coated,
Kraft release paper from H. P. Smith, Inc. The solvent was flashed
off in a drying oven at 150-300F. (65-150 C.) and recovered.
After drying, the release paper/adhesive composite was laminated
to the non-woven side of the non-woven/vinyl film construction.
In order to achieve the desired degree of penetration of the ad-
hesive into the non-woven backing, the steel nip roll at the
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ClP of C-5066
lamination station was heated to about 185F, (85C.) and placed
against the release paper.
EXAMPLE 2
The same procedure as used in Example l was employed to
make a composite article using as the pressure sensitive adhesive
a commercially available adhesive from Daubert Chemical Company
("DC-7025") which was used without dilution by addition of
further solvent.
EX~MPLE 3
The same procedure as used in Example 1 was employed to
make a composite article using as the pressure sensitive adhesive
a commercially available adhesive from USM Corp. ("Bostik 7525")
which was used without dilution by addition of further solvent
The foregoing Examples illustrate preferred embodiment
of the present invention which should not be construed in a
limiting sense. The scope of protection that is sought is set
forth in the claims which follow.
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