Note: Descriptions are shown in the official language in which they were submitted.
PL-245
The present invention relates to normally nontacky
adhesive tapes and films and processes for applying them and
generally to such tapes and films which may be made tacky by the
application of pressure or other stress. One important specific
S application o this invention is to typewriter lift-off tapes which
are normally nontacky but are rendered sufficiently tacky to remove
erroneous typed ink impressions by striking the tape with type
activated by a ty~ewriter key ln the normal manner.
Various types of nontacky but po~entially tacky adhesive
0 tapes have been proposed which utilize means, such as spheres or
paxticles, imbedded in a tacky adhesive surface to prevent contact
with the tacky surface and thus shield the adhesive from the
application surface. These tapes are activated by pressure on the
back of the tape to further imbed the particles in the adhesive and
thus bring the adhesive into contact with the application surface
as disclosed in United States Patent No. 3,924,728 which relates
to a typewriter correction tape, or the applied pressure may cause
hollow spheres imbedded in the adhesive surface to collapse and
thus expose the adhesive as disclosed in United States Patents
0 No. 3,331,729 and 3,413,168. Another approach is to contain the
adhesive completely withi~ hollow capsules positioned along the
surface of the tape. The capsules themselves are nontacky but
adapted to break under pressure and thus render the tape tacky
and adhesive as disclosed in United States Patents No. 2,907,682
and 2,986,477. Another nontacky but potentially adhesive typewriter
correction tape is disclosed in United States Patent No. 3,998,314.
It describes the use of a wax-like layer which picks up and removes
ink impressions when pressure is applied to the tape.
-2- ~~
3L6~33
PL-245
Needless to say, the above-described tapes which
utilize hollow spheres are expensive to produce, particularly
when the spheres contain the adhesive. Furthermore, the resulting
adhesive surface tends to be irregular and somewhat unpredictable
in operation. The same is true of the use of solid spheres or
particles imbedded in the adhesive surface for shielding purposes.
Furthermore, when these tapes are wound in roll form a special
release coating must be applied to the tape backing in order that
the tape'may be again unwound. The wax-like layer of United 5tates
Patent No. 3,998,314 is not capable of developing ~he kind of tack
necessary to remove typed ink impressions clearly and without leav~
ing residue on the paper.
I have discovered a thermoplastic adhesive film material
which normally is nontacky and is convertible to a tacky state
by the application of substantial stress, i.e., stretching
sufficiently or striking with typewriter type as described above.
More specifically, this material exhibits a plastic state at low
elongations and an elastomeric state at high elongations and is
convertible from a normally nontacky and nonelastomeric plastic
state to a tacky elastomeric state by stressing the material to
cause it to pass through its plastic state and become tacky and
elastomeric. This film material consists essentially of thermo-
plastic and elastomeric A-B block copolymers wherein the A-blocks
are thermoplastic and the B-blocks are elastomeric and about 20-120
~5 parts per one hundred parts by weight of the block copolymers of
certain normally solid resins adapted to associate principally with
the thermoplastic A-blocks of said copolymers. In these copolymers
the A-blocks are derived from styrene or styrene homologues
and the B-blocks are derived from conjugated dienes or lower
alkenes.
In accordance with this invention, there is provided
a normally nontacky adhesive tape which comprises: a non-
adhesive backing layer and a normally nontacky and non-
elastomeric adhesive layer on one major surface of said back-
. ing layer, said backing layer being relatively inextensible _-
~ and said adhesive layer being relatively extensible, said
10 adhesive layer comprising an adhesive composition consisting
essentially of thermoplastic and elastomeric A-B block co-
polymers wherein the A-blocks are thermoplastic and the B-
` blocks are elastomeric and about 20-120 parts per one hundred
parts by weight of the block copolymers of normally solid
resins adapted to associate principally with the thermoplastic
A-blocks of said copolymers, said A-blocks being derived from
styrene or styrene homologues and said B-blocks being derived
from conjugated dienes or lower alkenes; said adhesive layer
exhibiting a plastic state at low elongations and an elasto-
~0 meric state at high elongations and being convertible from a
normally nontacky and nonelastomeric plastic state to a tacky
elastomeric state by subjecting said layer to substantial
stress to cause it to pass through its plastic state and
become tacky and elastomeric.
In accordance with another aspect of the invention,
there is provided the process of applying an adhesive film to
an application surface which comprises: a. selecting a
normally nontacky and normally nonelastomeric adhesive -film
consisting essentially of thermoplastic and elastomeric A-B
block copolymers wherein the A-blocks are thermoplastic and
the B-blocks are elastomeric and 20-120 parts per one hundred
parts by weight of the block copolymers of normally solid
-4-
resins adapted to associate principally with the thermo-
plastic A-blocks of said copolymers, said A-blocks being
derived from styrene ox styrene homologues and said s-blocks
being derived from conjugated dienes or lower alkenes, said
film exhibiting a plastic state at low elongations and an
elastomeric state at high elongations and being convertible
from a normally nontacky and nonelastomeric plastic state to
a tacky elastomeric state by subjecting said film to sub-
stantial stress to cause it to pass through its plastic state
and become tacky and elastomeric, b. subjecting a portion of
said film to substantial stress to cause it to pass through
its plastic state and become tacky and elastomeric, and
c. pressing the resulting tacky and elastomeric portion of
said film into adhering contact with said surface.
In the process of my invention substantial stress is
applied to a film of this normally nontacky block copolymer and
resin mixture to convert at least a portion of the film from
its normally nontacky and nonelastomeric plastic state to a
tacky elastomeric state and then the resulting tacky portion
is pressed into adhering contact with the desired application
surface. This stress may be applied by stretching the film
at least 100 percent in at least one direction although best
results may be obtained by stretching it several hundred per-
cent. When the film is used in a typewriter lift-off tape the
film may be converted to a tacky state by striking it with
typewriter type activated by a typewriter key in the normal
manner while the film is supported against further movement
with, or in the direction of movement of 9 the type by the
platen roll of the typewriter.
The adhesive film of my invention is highly extens-
ible and generally possesses an elongation to break of at
least about 300 percent9 although films of lower elongations
-4a-
6~3
to break may result when very high proportions of simple
block copolymers are employed in the adhesive composition.
As indicated hereinbefore, the film normally is nontacky,
plastic and inelastic in nature and retains these properties
at low elongations, whereas at higher elongations it becomes
tacky and elastic. I have discovered that the local dis-
tortion caused by typewriter type striking the film as
described hereinbefore, is sufficient to cause at least in- _
cremental conversion of the film to a tacky elastomeric state.
-4b-
6~3~
PL-245
This phenomenon will be discussed more fully hereinafter. Even
though this will occur when the type strikes the film itself,
I have determined that a superior adhesive tape may be produced
~or typewriter lift-off applications by laminating the adhesive
film to a relatively înextensive nonadhesive backing film.
The normally nontacky adhesive tape of my invention
comprises a nonadhesive backing layer or film and a normally
nontacky and nonelastomeric adhesive layer or film on one of the
major surfaces of the backing layer. Preferably the tape is wound
upon itself in successive convolutions in the form of a roll with
the adhesive layer ~acing inwardly toward the axis of the roll.
The nonadhesive backing layer or film of this invention `
may be formed from one of the known relatively i~extensible
plastics such as polyethylene terephthalate, isotactic polypro-
pylene, vinyl chloride polymer, or the like.
As indicated hereinbefore, the adhesive layer of the tape
of this invention is relatively extensible when compared With the
backing layer and comprises an adhesive composition consisting
essentially of thermoplastic and elastomeric A-B block copolymers
` ~ wherein the A-blocks are thermoplastic and are derived from styrene
or styrene homologues and the B-blocks are elastomeric and are
derived rom conjugated dienes or lower alkenes, together with
about 20-120 parts, preferably 30-90 parts, per one hundred parts
by weight of the b~ock copolymers o~ certain normally solid resins
~5 adapted to associate principally with the thermoplastic A-blocks
of said copolymers.
--5--
,
-
6~3
The thermoplastic and elastomeric A-s block copo-
lymers of this invention consist essentially of linear or
radial A-B-A block copolymers, mixtures of the aforesaid
A-B-A block copolymers with simple A-B-block copolymers, and
in some cases the simple A-s block copolymers themselves.
Preferably, the proportion of A-B block copolymers in the
mixture of A-B-A and A-B block copolymers does not exceed
about 75 percent by weight.
The A-B-A block copolymers of this invention are of
the type which consists of A-blocks (end blocks) derived,
i.e., polymerized or copolymerized, from styrene or styrene
homologues; and B-blocks (center blocks) derived from
conjugated dienes, such as isoprene or butadiene, or from
lower alkenes, such as ethylene and butylene. Small pro-
portions of other monomers also may enter into the block
copolymers themselves. Preferably, the individual A-blocks
have a number average molecular weight of at least about
6,000 preferably in the range of about 8,000 - 30,000, and
the A-blocks constitute about 5 - 50 percent, preferably
about 10 - 30 percent, by weight of the block cop~lymer.
The number average molecular weight of the B-blocks for
linear A-B-A block copolymers preferably is in the range of
about 45,000 - 180,000 and that of the linear copolymer,
itself, preferably is in the range about 75,000 - 200,000.
The number average molecular weight of the radial A-B-A
block copolymers preferably is in the range of about 125,000 -
400,000. The designation A-s-A includes what are sometimes
called A-B-C block copolymers wherein the end blocks are
different from one another but both are derived from styrene
or styrene homologues. This applies both to linear and
~f - 6-
radial block copolymers. The term "linear block copolymer"
tor copolymers) includes branched A-B-A copolymers as well
as unbranched A-B-A copolymers.
- 6a -
"~
PL-245
~he radial A~B-A polymers useful in this invention are
of the type described in United States L~tters Patent No. 3,281,383
and conform to the following general formula: (A-B-)nX, wherein
A is a thermoplastic block polymerized from styrene or styrene
homologues, B is an elastomeric block derived from conjugated
dienes or lower alkenes, as indicated above, X is an organic or
inorganic connecting molecule with a functionality of 2 4 as
described in Patent No. 3,281,383 or possibl~ with a higher funtion-
ality as described in the article entitled"New Rubber is Backed by
O Stars" appearing on page 35 of the June 11, 1975 issue of Chemical
Week. "n" then is a number corresponding to the ~unctionality of X.
The simple A-B block copolymers of this invention are of
the type described in ~nited States Letters Patent Nos. 3,519,585
and 3,787,531 and comprise A and B-blocks derived from the monomers
described hereinbefore in connection with the A-B-A copolymers.
The adhesive composition of this invention may include
small amounts of other more conventional elastomers but these should
not exceed about 25 percent by weight of the total elastomers in the
composition. These other elastomers may lnclude, highly broken down
O natural rubbers and butadiene-styrene random copolymer rubbers,
synthetic poly-isoprene, chloroprene rubbers, nitrile rubbers, butyl
rubbers, and the like. Potentially elastomeric liquid polymers also
may be employed as additives but normally in lower proportions not
above about 10 percent by weight of the total elastomers.
~5 The normally solid resins of this invention consist
essentially of low molecular weight resins which are adapted to
associate principally with, and are principally compatible with,
--7--
5~3
PL-245
the thermoplastic A-blocks of the said block copolymers, and which
when mixed with said A-B copolymers provide a nontacky adhesive
film which exhibits a plastic s~ate at low elongations and an
elastomeric state at high elongations and is convertible fxom its
nontacky plastic state to a tacky elastomeric state by stressing
the film to cause it to pass through its plastic state and become
tacky and elastomeric. Alpha-methylstyrene-vinyl toluene and
coumarone-indene copolymers are exampies of these normally solid
A-blocks associating resins of my invention. Preferred resins for
.0 this purpose possess a number average molecular weight not above
about 3,000 al~hough higher molecular weight resins in the low
molecular weight range also may be employed. Small proportions, i.e.,
not above about,25 percent of the total resin content, of various
other resins, also may be employed in the adhesive composition of
this invention.
As indicated hereinbefore, the A-block associating resins
of this invention are normally solid, i.e., they consist of solid
resins but may include liquid A-block associating resins mixed in
minor amounts with solid A-block associating resins provided that
2~ the resulting mixture is solid at normal room temperatures, i.e.,
about 70-80F.
The adhesive composition also may contain relatively small
proportions of various other materials such as antioxidants, heat
stabilizers and ultraviolet absorbers, extenders, fillers and the
~5 like. Typical antioxidants are 2,5-ditertiary amyl hydroquinone
and ditertiary butyl cresol. Similarly, conventional heat stabiliz-
ing antioxidants such as the zinc salts of alkyl dithiocarbamates
6~3
PL-245
. .
may be used. Relatively small proportions, not above about
25 parts by weight of the total elastomers, of various extenders
such as polystyrene, nonreactive phenolformaldeyhde resins, linear
polyester resins, polyethylene, polypropylene, etc., also may be
included in the film forming composition of this invention.
Similarly, the adhesive composition of this invention may include
relatively small proportions of fillers and pigments such as zinc
oxide, aluminum hydrate, clay, calcium carbonate, titanium dioxide~
carbon black and others.
~0 Other and further features and advantages of the invention
will appear to one skilled in the art from the following description,
examples and claims, taken together with the drawings wherein:
Fig. l is a view in perspective a roll of tape according
to this invention.
~5 Fig. 2 is a schematic cross-sectional view of the tape
of Fig.l taken along the line 2-2 of that figure.
`~ Fig. 3 is a somewhat enlarged schematic view, partly in
section and partly in elevation showing the tape of the preceding
- figures as it is being struck by typewriter type to remove an ink
0 impression from a piece of typewriter paper.
Fig. 4 is a plan view illustrating the method used ln the
- following examples to adhere the tape of this invention to a
substrate by a typewriter, for the purpose of measuring the adhesive
strength of the tape.
~S Referring to Fig. 1 of the drawings, there is shown a
roll 10 of the normally non-tacky adhesive tape of this invention,
wherein the tape 11 comprises a relatively inextensible and non-
adhesive backing layer 12 and a relatively extensible and nor~ally
PL-245
non-tacky adhesive layer 13 on one major surface of the backing
layer 12. The tape 11 is wound upon itself around a hollow
tubular core 14 with the adhesive layer 13 facing inwardly
toward the axis of the core to form ~he roll. Fig. 2 illustrates
S the relationship between the relatively inextensible,lbacking layer
12 and the relatively extensible adhesive layer 13.
In Fig. 3, the tape 11 is inverted with the adhesive layer
13 facing do~-nward toward an ink impression 16 on a piece of type-
writer paper 17 as the backing 12 of the tape is being struck by a
.~ type 15 activated by a typewriter key in the no~mal manner. The type
lS is for the same letter or number as that of the ink impression 16
so that the lines or points of maximum pressure applied by the type
15 to the tape 11 correspond in outline to that of the ink impression
16, although this outline is not shown. The adhesive layer or film
~5 13 is distorted by the type striking the tape, particularly at the
edges of the type, which of coursé,correspond to the edges of the
ink impression. It is believed that the local or incremental
distortion of the adhesive film-13 creates substantial stress in
the film 13 at the edges of the in~ impression 16 underneath the
edges or corners of the type 15 and that,at least in these areas,
the film is converted from a non-tacky plastic state to a tacky
alastomeric state. At any rate, when the type strikes the tape
and presses the adhesive layer 13 against the ink impression 16 on
the paper 17, the adhesive layer sticks to the ink impression, and
S when the tape 11 is removed from the paper, the ink impression 16
is removed from or~-lifted-off, the paper by the tape.
--10--
.
PL-245
When the tape 11 is stuck by the type 15 and moved into
contact with the ink impression, the tape with its adhesive layer
or film 13 is supported against further movement with, or in the
direction of movement of, the type 15 by the platen roll 20 of the
typewriter which in turn~ supports the paper 17. It should be noted
that the amount of distortion which occurs in the relatively extensi--
ble adhesive film 13 of the tape 11 is controlled by the fact that
the adhesive film 13 is laminated to the relatively inextensible
backing layer 12 which is struck first and therefore must be dis-
torted irst by the type 15. This also helps assure positive removalof the tape and the ink lmpression from the paper 17 when the type
15 is lifted of the tape. However, it is preferred that the
thickness of the backing layer 12 be held to a minimum to assure
the most efficient conversion of the adhesive film to a tacky state
when the tape is struck by the type.
Fig. 4 shows a length of tape 11 of this invention
adhered to a piece of standard adhesion test board 18 through four
rows of the capital letter X typed onto the backing 12 of the tape
while the tape is juxtaposed with the test board 18. The four rows
~0 ~ of Xs are single spaced and are typed by activating a standard
typewriter keyboard in the normal manner. This converts the
adhesive layer of the tape to a tacky state underneath or along
the edges of the Xs thereby adhering the tape to the test board
through each o~ the Xs. This method is used for adhering
~5 the tape to the substrate in the following Examples 11 through
~3 for the purpose of testing for adhesion or adhesive strength.
`` The test board 18 used for testlng adhesion in these examples is
National Bureau of Standards standard reference 1810 liner board.
q33
PL-245
The following examples of adhesive tapes and processes
according to my invention are given only by way of illustration
and are not intended t~ limit the scope of the invention in any
way. In the examples, all proportions are expressed in parts
S per one hundred parts by weight of the total elastomers unless
otherwise indicated. Adhesive strength or adhesion to steel is
measured in ounces per inch of width by peeling the tape backing
over itself 180 at a constant speed (by a orce applied to the
free end of the tape) from a smooth steel surface, or from the
~0 test board for Examples 11-23, to which i~ has been applied by
a fixed pressure. For the techniques used in conducting this
test, see the 180 peel adhesion test PSTC-l of the Pressure
Sensitive Tape Council.
In Examples 1-10, adhesive films 5 mils thick are
.5 extruded from the formulations indicated in Table-A. The extruded
films are then stretched several hundred percent of their length
to convert them from their normally nontacky plastic state to a
tacky elastomeric state. As the films are stretched a visible
change takes place as they are converted from a nontacky to a
~0 tacky state. The tacky stretched films then are allowed to relax
a~ter which they are laminated to lengths of 1 mil thick poly-
ethylene terephthalate film by rolling the films together with
a ~our and one half pound roller. The resulting adhesive tapes
-12-
~4~L6~3
H
~n n ~ Q
O ~n ~ O O O
N 1' 1' ~ ~3 ~3 !z;
~ ~ .
~3 3 r~ o ~ .
I' ~ ~ (D 1'- 0
~ ~ t o o
- 3 ~ 1- o o o o O
n
O ~ o ~ g r~
tq O ~ (D
1- co
Pl (D rt
Q m n o
~D n (D ~
~q (D
H
o ~ o~ ~_
~ O ~3~. 0 ~ ~ o o w
o n n
p,
1--
O 1-
,~ O Ul ~ O O
v
O 1--
O
0~ n ~ O o
~O
p,
~c o l-
o
~ ~ ~n ~ O O
(D
c o
~- ~ O
O ~n
Ul ~ O
r~ ~
1'-
n O 1-
O ~
~D ~ t
U~ 1- 1-
1,. ~ 1_ D O O ~ U~
pl O U'l ~) O O
C
Co
I_ ~ O O
O O
O l_ l_ ~
~ O
~n ~ O o
0 1- 1_ 1~
~.) O O
O ~Jl ~ O O
3~ -13-
;C)3
.
PL-245
then are tested for adhesion to steel as described hereinbefore.
The results are listed in Table A with any adhesion reading of
3 ounces or below being rounde~ out to zero. While the adhesions
obtained are somewhat erratic, they do indicate maximum effective-
ness, with the formulations tested, in ~he area of 60 to 80 partssolid resin.
In Examples 11-20, adhesive films 5 mils thick are
again extruded from the formulas described in Table B. Then
lengths of the film are juxtaposed with National Bureau of
Standards standard reference 1810 liner board, adhered thereto
by typewriter and tested for adhesive strength, as described
hereinbefore in connection with Fig. 4 with adhesions being
rounded out as for Examples 1-10. While the results indicate
adhesions less than for Examples 1-10, this is understandable
since the tape in Examples 11-20 is adhered to the test board
only under the Xs as compared with the substantially continuous
~dherènce between~the stretched rolled films of Examples 1-10.
Those adhesive films having an adhesive strength of 4 oz./in.
width or above by this test are capable of perfor~ing as ~ypewriter
lift-off tapes as described hereinbefore, although those having
an adhesive strength in the neighborhood of 10 oz.~in. width
perform more satisfactorily.
. ~ , . .
-14- ~
6~
~ ~ ~ ~
3 ~
o o r~
IJ- ~ ~ ~ _~ ~Q
~- o
IJ- O O O
r ~ O
o 5, ~ ~
~ ~
~
(D
o t- I_ 1~
O O ~ l
o ,_ ,_ t~
.n
~n ~ O O
6~ o 1_
~ o o ~
o ~, o ~
o Ul ~ o o
o~ o ~_
~ o o Ul
o ~ I~ 1~
O O t~
tq
o ~ o l-
O ~n ~ O O _~
~ o ~ o~ l-
~n ~ O O .'
o l- l-
- cn o ~
W Ul ~ o o ~'
o l -
~n ~n ~ o o ,~
B -15-
In Examples 21-33 adhesive films 0.75 mils thick
(weighing about 0.75 oz~/yd~ 2) are coated from the formula-
tions described in Table-C onto one major surface of a
polyethylene terephthalate backing film, also 0.75 inches
thick, to produce tapes of this invention. rrhe tapes then
are applied to test board by typewriter with the type
stricking the backing film as described in connection with
Fig. 4 and Examples 11-20, with the results being rounded as in
the foregoing examples. It will be noted that the adhesion
obtained in all by Example 25 are adequate for typewriter
lift-off applications. It also should be noted that the
values for adhesive strength obtained in these examples are,
if anything, somewhat higher than for Examples 11-20 even
though the thickness of the adhesive film in Examples 21-33
is only 0.75 mils, as compared with 5 mils for Examples 11-20,
and the very thin film of Examples 21-33 is covered with an
equally thin backing film of a MYLAR type polyester, MYLAR is
a trademark of E. I. du Pont de ~emours & Co., Inc. for their
polyester.
In the foregoing e~amples KRArrON 1107 block copolymer
is a thermoplastic elastomeric A-s-A (styrene-isoprene-styrene)
block copolymer of this invention offered by the Sheel Chemical
Company, wherein the styrene content (that of the A-blocks)
is about 12-15 percent, closer to 15 percent by weight of the
block copolymer, and the polymer possesses a solution viscosity
of about 2,000 centipoises at 25 percent solids in toluene
at room tenperature (using a Brookfield Viscometer with a ~o.
spindle at 60 r.p.m.), and a number average molecular weight of
about 110,000 - 125,000. KRArro~ 1102 copolymer is another
A-B-A block copolymer offered by Shell but this is a styrene-
butadiene-styrene copolymer wherein blocks constitute about
28-30 percent
6~3
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Q
(D I n ~ ~
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{Q It ~ 1-- 00
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X
(D ~ I ~ ~pJ
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tD 1- 0 0 ~ OO
NO ~ n ~.
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~ ~ ~ r~
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< ~ o
1-- ~ (D
PJ
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I-h O ~11 N O O 1--~ t'i
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1-- ~ O N
n ~ u- N O ON
o
O l_
P~ 1-- ' ~ O N
1~ 0 (Jl N O O ~
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0 1-
Co ON
1'- C~ (J~ N O O
O 1--
~ O
(D O ~Jl N O O ~Jl
O 1- ~
~ ON
O Ul N O O~)
O 1- t-~
~_ CO N C/~
~? 14 01 N O O ~1
O l_
1-- Ul N O O N
l_ . (S~O ~)
(JJ l.ll N OO ~O
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O ~JI N O g ~ ~.
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13 -17-
_l
6~3
of the copolymer. The number average molecular weight of
KRATO~ 1102 copolymer also ,s about 125,000.
CUMAR 509 LX resin is a solid coumarone~indene
copolymer resin offered by the Neville Chemical Co., and
having a softening point of about 145C. PICCOTEX 100 and
120 resins are alpha-methyl styrene-vinyl toluene copolymers
offered by Hercules Chemical Co~, with melting points of
100C. and 120C., respectively.
- Having now described the invention in specific detail
and examplified the manner in which it may be carried into
practice, it will be readily apparent to those skilled in the
art that innumerable variations, applications, modifications,
and extensions of the basic principles involved may be made
without departing from its spirit or scope. For instance,
although they have not been described or shown m~re specific-
ally, various additional coat~n~s o~ layers conventionally
incorporated in adhesive tapes intended to be wound in roll
form also may be included in the adhesive tape of this
invention. This is particularly true when the tape must be
designed to withstand aging at fairly high temperatures. Since
high temperatures may cause ~low of the thermoplastic adhesive,
a release coating may be desired on the surface of the backing
opposite to the adhesive to assure easy unwind from the roll
and a primer layer may be desired between the adhesive and the
bac~ing to assure that delamination does not occur between
the adhesive and the backing under even the most extreme
circumstances.
.~ . I
