Mounting tape

The adhesive coated foam laminates of the present invention comprise a polyolefin or polyvinyl chloride foam layer coated on one or more sides with a pressure sensitive adhesive which comprises: PA1 (a) a block polymer of monovinyl aromatic hydrocarbon and either a conjugated diene or ethylene-butylene; PA1 (b) at least two distinct tackifying resins; and PA1 (c) at least one oxidation stabilizer.

BACKGROUND OF THE INVENTION 
Pressure sensitive mounting tapes for high temperature creep resistant 
applications such as automotive specification requirements have heretofore 
been made with foams other than polyolefins because of the difficulty in 
obtaining a high temperature resistant bond of a pressure sensitive 
adhesive to polyolefins in comparison to other foams such as 
polychloroprene, polyurethane, and polyacrylate. 
The present invention demonstrates that high temperature performances can 
be attained with a particularly formulated pressure sensitive adhesive in 
combination with a polyolefin foam. This product possesses characteristics 
such that its high temperature shear resistance is even greater than that 
observed with the aforementioned products currently being used in these 
applications. 
SUMMARY OF THE INVENTION 
The adhesive-foam laminates of the instant invention comprise a low weight 
foam material consisting of a foamed polyolefin such as polyethylene, or a 
copolymer thereof, such as containing minor amounts of polyvinyl acetate, 
or a foamed polyvinyl chloride, having one or more sides coated with a 
pressure sensitive adhesive. This adhesive coated foam can be easily 
attached to any of a number of surfaces, such as metal, wood, plaster, and 
ceramic surfaces and the like. The adhesive coated foam products of the 
present invention, once adhesively attached to a surface, remain firmly 
attached in spite of severe weather conditions such as high temperatures, 
freezing temperatures or extreme humidities. 
One of the useful applications of the adhesive products of the present 
invention is that of a mounting strip for trim stripping on the sides of 
automobiles. The advantages of the use of the adhesive coated core 
products of the instant invention over the use of other adhesive coated 
foam laminates presently used as mounting strips, such as adhesive coated 
polyurethane foams, include lower cost, and improved adhesion in all types 
of weather conditions.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
The adhesive coated foam laminates of the present invention comprise a 
relatively thin polyolefin or polyvinyl chloride foam layer coated on one 
or more sides with a pressure sensitive adhesive which comprises: 
(a) a block polymer of monovinyl aromatic hydrocarbons and either a 
conjugated diene or ethylene-butylene; 
(b) at least two distinct tackifying resins; and 
(c) at least one oxidation stabilizer. 
A foam core product having only one adhesive coated face is contemplated as 
part of the present invention and may be useful as protective foam 
stripping as printable lable stock and the like. The foam layer may be 
made from any light weight polyolefin (e.g. polyethylene or polypropylene) 
or polyvinylchloride foam material such as polyethylene foams, including 
closed cell crosslinked polyethylene foams and crosslinked polyethylene 
copolymer foams containing minor amounts of copolymerized vinyl acetate. 
Examples of commercially available foams contemplated for use in the 
present invention include Volara Type A foam and Volara Type E foam 
manufactured by Voltek, Inc. Adhesive foam pad fasteners are known in the 
art for mounting household articles. The thin foam layer employed in those 
pads can be employed in the laminates of the present invention. 
The foam material may be produced and used in any configuration having two 
or more sides with one or more sides being adhesively coated. While the 
foam core may be configured for attachment to any irregular surface and 
any such configuration is contemplated to be within the scope of the 
present invention, the present invention will be illustrated through the 
use of rectangular cross section foam having adhesive coating on both of 
the major rectangular surfaces. Generally the foam layer will be less than 
about 1/2 inch thick, usually about 1/4 inch or less. 
ADHESIVE COMPOSITION 
The adhesive compositions utilized in the production of the adhesive-foam 
laminate comprises: 
(a) a block polymer of monovinyl aromatic hydrocarbon and either a 
conjugated diene or ethylene-butylene; 
(b) at least two distinct tackifying resins which serve to extend the 
adhesive properties of the system; and 
(c) at least one stabilizer. 
The basic polymer component of the adhesive composition may be described as 
an unvulcanized elastomeric block copolymer wherein the respective 
monomeric moieties are arranged in an alternating sequence having the 
general configuration A-B-A wherein A is a non-elastomeric polymer block 
derived from a monovinyl aromatic hydrocarbon monomer and B is an 
elastomeric polymer block derived from the moieties of a conjugated diene 
monomer or ethylene-butylene; the total concentration of the A block 
therein ranging from about 20 to 50%, as based on the total weight of the 
polymer. An additional configuration which has been applied to these three 
unit block polymers if (SSS).sub.n -(BBB).sub.n (SSS).sub.n wherein S 
represents the moieties derived from the vinyl substituted aromatic 
hydrocarbon monomer in which the vinyl group is attached to a nuclear 
carbon atom and B represents the moieties derived from the conjugated 
diene monomer or ethylene-butylene. It should be noted that, in these 
polymers, styrene is ordinarily used as the monovinyl aromatic hydrocarbon 
member while butadiene or isoprene are the most frequently used conjugated 
diene members. Thus, for example, styrene-butadiene-styrene polymers are 
commercially available under the trademarks "Kraton 1101", "Kraton 1102," 
"Kraton 4122," "Kraton 4141," and "Kraton 4150." Styrene-isoprene-styrene 
polymers are commercially available under the trademark "Kraton 1107" and 
the styrene-ethylene-butylene-styrene polymers are commercially available 
under the trademark "Kraton G 1650," "Kraton G 1652," and "Kraton G 4609." 
The "Kraton" polymers are sold by the Shell Chemical Company. 
Methods for preparing the latter block polymers are well known to those 
skilled in the art; typical procedures being disclosed in U.S. Pat. No. 
3,265,765, issued Aug. 9, 1966, hereby incorporated by reference. These 
procedures generally involve the solution polymerization of a mixture 
containing the monovinyl aromatic hydrocarbon monomer and the conjugated 
diene monomer in the presence of a catalyst of the formula R(Li).sub.x 
wherein x is an integer having the value of from 1 to 4 and R is a 
hydrocarbon radical selected from the group consisting of aliphatic, 
cycloaliphatic and aromatic radicals. 
The tackifying resins employed in the adhesive serve to extend the adhesive 
properties of the block polymer. As contemplated in the invention, 
suitable "tackifying resins" include: 
(1) phenolic-modified terpene resins having a Ball and Ring softening point 
of from 90.degree. to 150.degree. C., for example, as commercially 
available under the tradename "Piccofyn A135" made by Hercules, Inc.; 
(2) glycerol and pentaerythritol esters of natural and modified rosins, 
such as, for example, the pentaerythritol ester of hydrogenated rosin, the 
glycerol ester of polymerized rosin, and the phenolic-modified 
pentaerythritol ester of hydrogenated rosin, for example, as commercially 
available under the tradename "Foral 105" by Hercules Inc.; 
(3) phthalate ester of hydroabietyl alcohol, commercially available under 
the tradename "Cellolyn 21" made by Hercules Inc. 
(4) natural and modified rosins such, for example, as gum rosin, wood 
rosin, tall-oil rosin, distilled rosin, hydrogenated rosin, dimerized 
rosin, and polymerized rosin; 
(5) polyterpene resins having a softening point, as determined by ASTM 
method E28-58T, of from about 80.degree. to 150.degree. C.; the latter 
polyterpene resins generally resulting from the polymerization of terpene 
hydrocarbons, such as the bicyclic mono-terpene known as pinene, in the 
presence of Friedel-Crafts catalysts at moderately low temperatures; 
(6) chlorinated terphenyl resins containing from about 42 to 60%, by 
weight, of chlorine; and 
(7) aliphatic petroleum hydrocarbon resins having a Ball and Ring softening 
point of from about 70.degree. to 135.degree. C.; the latter resins 
resulting from the polymerization of monomers consisting primarily of 
olefins and diolefins. 
It appears that the phenolic modified terpene resin (1) is a preferred 
ingredient in the adhesive composition in order to obtain the high shear 
performance desired. However, in order to enhance the apparent tackiness 
of the adhesive surface and the initial tack of the laminate to a surface, 
at least one other instant tack enhancing resin such as (2)-(7) is added 
to the composition. 
The stabilizers which are present in the adhesive composition serve to 
protect the otherwise vulnerable block polymer, and thereby the adhesive 
system, from oxidative and thermal degradation which are frequently 
encountered during the manufacture and application of the adhesive as well 
in the ordinary exposure of the final adhered product. Such degradation is 
usually manifested by deterioration in appearance, physical properties and 
performance. Among the applicable stabilizers are included high molecular 
weight hindered phenols and multifunctional phenols such as sulfur and 
phosphorous-containing phenols. Hindered phenols are well known to those 
skilled in the art and may be characterized as phenolic compounds which 
also contain sterically bulky radicals in close proximity to the phenolic 
hydroxyl group thereof. In particular, tetiary butyl groups generally are 
substituted onto the benzene ring in at least one of the ortho positions 
relative to the phenolic hydroxy group. The presence of these sterically 
bulky substituted radicals in the vicinity of the hydroxyl group serves to 
retard its stretching frequency and, correspondingly, its reactivity; this 
steric hindrance thus providing the phenolic compound with its stabilizing 
properties. Representative stabilizers include: 
zinc dibutyldithiocarbamate 
tetra-bis methylene 3-(3,5-ditertiary-butyl-4-hydroxyphenyl)-proprionate 
methane 
2,2-methylene-bis(4-methyl-6-tertiary butyl phenol) 
4,4-thiobis-(6-tertiary-butyl-m-cresol) tri(nonylated phenol)phosphite 
The performance of these stabilizers may be further enhanced by utilizing, 
in conjunction therewith: (1) synergists such, for example, as 
thiodipropionate esters and phosphites; and (2) chelating agents and metal 
deactivators such, for example, as ethylenediamine tetraacetic acid, salts 
thereof, and disalicylalpropylenediimine. 
The stabilizers are employed in the adhesive compositions in minor 
stabilization effecting amounts. 
Optional additives may be incorporated into the adhesive such as silane 
adhesion promoters, such as, vinyltriethoxysilane, 
.gamma.-methacryloxypropyltrimethoxysilane, 
.gamma.-glycidoxypropyltrimethoxysilane, 
.gamma.-mercaptopropyltrimethoxysilane, 
.gamma.-aminopropyltriethoxysilane, and 
N-.beta.-(aminoethyl)-.gamma.-aminopropyltrimethoxysilane. 
Solvents are used in the preparation and/or application of the adhesive 
formulations of the present invention and are apparent to those skilled in 
the art. Typical solvents which are useful in the preparation of the 
adhesive formulation include aliphatic hydrocarbons such as heptane, 
aromatic hydrocarbons such as xylene and toluene and aliphatic esters such 
as n-butyl acetate and ethyl acetate. 
The typical ratio of components in the adhesive formulations is as follows: 
______________________________________ 
composition 
Parts by Weight 
Typical 
Preferred 
______________________________________ 
Block polymer of monovinyl 
40-100 50-70 
aromatic hydrocarbons and either 
conjugated dienes or ethylene- 
butylene 
Total tackifying resins 
30-80 50-70 
Additives (anti-oxidants, 
0.5-20 2-10 
adhesive promoters) 
______________________________________ 
The adhesive layer desirably has a thickness of at least 0.0002 inch, 
preferably in the range of about 0.001 inch to about 0.005 inch, on each 
adhesive coated face of the foam. While this amount of adhesive is 
sufficient to anchor the foam contemplated for use in the present 
invention, larger amounts of adhesives may be mandated for the anchoring 
of particular structures. 
The adhesive layer may be deposited on one or more faces of the foam layer 
by means of conventional applicator equipment. 
A typical coating process employed to produce the laminate product of the 
present invention is as follows: A 250 Ft. by 56 inch master roll 
containing 74 lb. per ream paper with a silicone release coating on each 
side is coated with an adhesive composition in an amount measuring 1.55 to 
1.65 ounces per square yard when dried in an oven for four minutes at 
220.degree. F. in a continuous process. This adhesive film is then 
transfer coated to a polyethylene foam type, having a density of six 
pounds per cubic foot, leaving the residue liner intact. The reverse 
uncoated side of the polyethylene foam is then directly coated by brushes 
with 1.90 to 2.00 ounces per square yard of the same adhesive, again 
drying the resultant laminate for four minutes at 220.degree. F. The 
mounting tape product is finally wound up in a roll against the other 
silicone coated side of the paper release liner. The final adhesive coated 
foam core product formed by this process one transfer coated adhesive 
layer and one direct coated adhesive layer. The adhesive coated foam 
products may be either totally transfer coated or directly coated. 
The following examples will further illustrate the embodiment of this 
invention. In these examples all parts given are by weight unless 
otherwise noted. All times of recorded hours followed by a (+) denotes 
experiment terminated without failure. 
EXAMPLE I 
This example illustrates the preparation of a typical adhesive composition 
of the present invention, its application to a polyethylene foam core and 
the adhesive performance of the adhesive coated foam core product. 
COMPOSITION A 
______________________________________ 
Parts 
______________________________________ 
Styrene-butadiene-styrene block polymer 
50 
(Shell Kraton 1101) 
Pentaerythritol ester of a hydrogenated 
25 
rosin (Hercules Foral 105) 
Phenolic modified terpene resin 
35 
(Hercules Piccofyn A 135) 
Polyterpene resin (Good year Wingtack 10) 
9 
(2,2'-methylene)-bis(4-ethyl-6-tert-butyl 
1 
phenol) 
3,3'-dilauryl thiodipropionate 
1 
Ethyl Acetate 14 
Toluene 60 
Heptane 91 
Solids - 45.6% 
______________________________________ 
The adhesive composition of Composition A was applied in an amount of 1.75 
ounces (dry) per square yard on silicone paper and then transfer coated on 
both sides of 1/16" thick polyethylene foam (Volara Type A). 
A number of weights of increasing weight were attached to a hook which was 
supported by a 1/4 square inch adhesive coated foam piece as prepared 
above. This test of shear strength, as the square was hung on a vertical 
metal surface, demonstrated the superior shear strength of the adhesive as 
after the weight exceeded ten pounds the adhesive bond did not fail but 
instead the foam tore. 
In a test of shear strength, a five pound weight was attached to a hook 
supported on a vertical metal surface by a 1/4 square inch adhesive coated 
foam piece (20 lbs/in.sup.2) at a temperature of 120.degree. F. No failue 
was noted after 195 hours after which time the test was terminated. 
EXAMPLE 2 
This example illustrates the improvement in the use of the adhesive 
formulations of the present invention in securing polyethylene foam as 
compared to conventional adhesives mounting tapes: 
COMPOSITION B 
______________________________________ 
Parts 
______________________________________ 
Styrene-butadiene-styrene block polymer 
50 
(Kraton 1101) 
Pentaerythritol ester of a hydrogenated 
25 
rosin 
Phenolic modified terpene resin 
35 
Phthalate ester of hydroabietyl alcohol 
6 
(Hercules Cellolyn 21) 
Gamma-Mercaptopropyltrimethoxy silane 
1 
(Union Carbide A-189) 
(2,2'-methylene)-bis(4-ethyl-6-tert-butyl 
1 
phenol) 
3,3'-dilauryl thiodipropionate 
1 
n-Butyl acetate 165 
______________________________________ 
COMPOSITION C 
______________________________________ 
Parts 
______________________________________ 
Styrene-butadiene-styrene block polymer 
50 
(Kraton 1101) 
Pentaerythritol ester of hydrogenated rosin 
25 
Phenolic modified terpene resin 
35 
Phthalate ester of hydroabietyl alcohol 
6 
Toluene 82.5 
Xylene 82.5 
Gamma-Mercaptopropyltrimethoxy silane 
1 
(2,2'-methylene)-bis(4-ethyl-6-tert- 
1 
butylphenol) 
3,3'-dilauryl thiodipropionate 1 
Solids - 41.9% 
______________________________________ 
In this test one square inch section of polyethylene foams were coated with 
adhesive compositions of the present metal invention and subjected to 
shear when mounted on a vertical metal surface by supporting weights of 
either 500 grams, 1000 grams or 5 pounds at various temperatures 
(158.degree. F., 170.degree. F., or 180.degree. F.). The number of hours 
for which the adhesive coated polyethylene foam pieces withstood this 
shear force was recorded. Their shear strength was then compared with the 
shear strength at identical conditions of the commercial mounting foam 
tapes manufactured by Morgan D6120 and Sekisui. 
TABLE I 
______________________________________ 
Volara 
Adhesive 
Foam Weight 
Compo- Type.sup.1 
Shears Hours Shear At 
sition (Color) Per in.sup.2 
158.degree. F. 
170.degree. F. 
180.degree. F. 
______________________________________ 
C E (Black) 500 grams -- 411.sup.+ 
121-136 
B E (White) 500 grams -- 411.sup.+ 
112.sup.+ 
B A (White) 500 grams -- 260-375 
15-71 
C E (White) 500 grams -- 411.sup.+ 
100 
Morgan D6120 500 grams -- &lt;63 22 
Sekisui 500 grams -- &lt;1/2 1/5 
C E (Black) 1000 grams 
281/2- 
72-87 51/4 
431/2 
B E (White) 1000 grams 
387.sup.+ 
78-93 23/4 
B A (White) 1000 grams 
431/2- 
28 21/4 
461/2 
C E (White) 1000 grams 
481/2- 
6-21 6-21 
1631/2 
Morgan D6120 1000 grams 
1 3/4 1/4 
Sekisui 1000 grams 
&lt;1/2 1/10 1/7 
C E (Black) 5 pounds 2 1 -- 
B E (White) 5 pounds 21/2 2 -- 
B A (White) 5 pounds 5 1/10 
1 1/10 -- 
C E (White) 5 pounds 21/2 1 3/5 -- 
Morgan D6120 5 pounds 1/3 1/4 -- 
Sekisui 5 pounds 1/3 1/10 -- 
______________________________________ 
.sup.1 Type A Crosslinked polyethylene by Voltek, Inc. 
Type E Crosslinked polyethylene copolymer foam by Voltek, Inc. 
TABLE II 
______________________________________ 
Hours Before 
Hours Before 
Adhesive Volara Foam 
Adhesive Non-Adhesive 
Composition 
Type (Color) 
Failure Failure (Foamtore) 
______________________________________ 
C E (Black) -- 1033-1048 
C A (White) 2682+ -- 
C E (White) 2682+ -- 
C A (Black) 2682+ -- 
A A (White) -- 73-136 
Morgan D6120 3-18 -- 
Sekisui 1464-1480 -- 
______________________________________ 
Table I demonstrates the results of the comparative testing of adhesive 
formulations on polyethylene foam tape with the best competitive mounting 
tape made by and hereinafter referred to as Morgan D6120 and Sekisui. As 
can be seem from the results of Table I the adhesive foam composites of 
the present invention conclusively and consistently outperformed the 
present commercial mounting tapes with respect to withstanding shear at 
elevated temperatures. 
EXAMPLE 3 
Polyethylene foam pieces measuring 3/4" by 13/8" supporting a plastic hook 
were adhered to a stainless steel wall supporting a five pound weight on 
the hook in a humidity chamber maintaining 100% relative humidity at 
100.degree. F. Table II demonstrates the results of this test using 
various adhesive formulations of the present invention and contrasts the 
results with the results of the tests which used the commercially 
available mounting tapes of Morgan D6120 and Sekisui. 
EXAMPLE 4 
Adhesive Composition B and C were coated on 1/4 square inch pieces of both 
Volara foam types A and E. The adhesive compositions were transfer coated 
on one side of the 1/32 of an inch thick foam and directly coated on the 
other side of the foam. The adhesive coated foam cores were then used to 
support plastic pieces containing a hook against a stainless steel wall. 
The adhesive foam core pieces were varied in that the following tests were 
conducted with one piece being adhered so that the directly coated 
adhesive side faced the plastic hook (represented by D on Table III) while 
another piece undergoing the same tests had the transfer coated adhesive 
side facing the plastic hook (represented by T on Table III). Tests were 
then conducted for adhesion strength and shear strength (at room 
temperature and at 125.degree. F.) for both freshly adhered composites 
(unaged) and composites which were aged for seven days at 158.degree. F. 
In Table III the adhesion numbers listed are the number of pounds per 
square inch which were applied to the hook without adhesive failure before 
the foam tore. In all cases the foam tore before adhesive failure occurred 
except for the aged samples of direct coating against the plastic hook 
using adhesive composition B on the E White and E Black type foam. 
Weights of five pounds were hung from the plastic hooks adhesively 
supported by the 1/4 square inch composites of the present invention to 
measure shear in hours before adhesive failure. Likewise one kilogram 
weights were supported by hooks secured by 1/4 square inch composites at 
125.degree. F. to test for the hours of withstanding shear until adhesive 
failure at an elevated temperature. 
TABLE III 
__________________________________________________________________________ 
Volara 
Coated Side 
ADHESIVE COMPOSITION B 
ADHESIVE COMPOSITION C 
Foam Type 
To Hook 
A White 
A Black 
E White 
E Black 
A White 
A Black 
E White 
E Black 
__________________________________________________________________________ 
UNAGED 
Adhesion 
D 81/2 8 &gt;10 &gt;10 8 81/2 &gt;10 10 
(lb/in.sup.2) 
T 81/2 81/2 &gt;10 10 81/2 8 &gt;10 &gt;10 
5 lb. Shear 
D 341-429 
677-740 
173-188 
169-232 
242-306 
27744+ 
169-232 
264-352 
per 1/4in. 
T 270-286 
3840+ 146 289-304 
341-429 
2424-2440 
797-813 
600-663 
(hours) 
1 kg. Shear 
D 1106-1126 
914-930 
3837+ 
173-236 
510-575 
3602 3827+ 
2444+ 
per 1/4 in.sup.2 
T 986-1002 
1106-1126 
3837+ 
147 986-1002 
2472 510-575 
1700 
/125.degree. F. 
(hours) 
AGED 
Adhesion 
D 81/2 &gt;10 51/2 51/2 8 91/2 9 &gt;10 
(lb/in.sup.2) 
T 9 &gt;10 8 &gt;10 71/2 9 &gt;10 &gt;10 
5 lb. Shear 
D 192 330 54-70 
22 403 434-522 
46 24 
per 1/4 in.sup.2 
T 403 97-113 
46 2-17 166 415-479 
50-65 
46 
(hours) 
1 kg. Shear 
D 196 245-308 
54-70 
27 238 574-662 
77-140 
148 
per 1/4 in.sup.2 
T 77 24 52 72 385 410-427 
77-140 
72 
/125.degree. F. 
(hours) 
__________________________________________________________________________ 
EXAMPLE 5 
A polyvinyl chloride plastisol foam piece measuring one square inch was 
transfer coated with adhesive composition C. This laminate was adhered to 
a plaster wall and used to support a five pound weight under conditions of 
ambient temperature and 80 percent relative humidity. The adhesive failed 
after 120 hours. 
The pressure sensitive adhesive laminates of the present invention should 
resist a shear force of 500 grams per square inch at 158.degree. F. for at 
least 96 hours, preferably at least 150 hours without significant creep. 
These laminates should resist a shear force of 1 Kg per 1/4 square inch at 
125.degree. F. for at least 100, preferably 200, and most preferably 1000 
hours.