Electrically insulating film backing

A halogen-free, electrically insulating film comprising a resin component containing: PA1 a) from 0 to about 40 parts of a rubber selected from EP or EPDM rubber, PA1 b) correspondingly, from about 60 to about 100 parts of an ethylene vinyl acetate polymer, PA1 c) from about 40 parts to about 150 parts ethylene diamine phosphate per 100 parts of said resin component, and PA1 d) from about 0.5 to about 5 parts of an amino-functional silane coupling agent per 100 parts resin component, wherein a nonoriented film self-extinguishes in less than about 5 seconds, has an elongation at break of at least about 200%, a dielectric strength of at least about 1200 V/Mil, and said film has a stress-strain relationship such that a curve showing a first derivative of stress versus strain is positive over the entire curve, and a curve showing a second derivative of stress versus strain is negative over more than 50% of said curve.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to electrically insulative polymeric films useful as 
conductive insulators and electrical tape backings that contain no halogen 
material. 
2. Description of the Related Art 
Various electrically insulative resins are known in the art. Polyolefins 
have been used in various resins, with and without flame retardancy in the 
electrical industry. 
Most insulative films which are used commercially, and have both good flame 
retardancy and good physical properties contain some vinyl chloride. 
Because of the toxins produced when such compositions are burned, either 
accidentally or when discarded, it is desirable to reduce the halogen 
content as much as is possible, particularly chlorine content. However, it 
is difficult to attain both the flame retardancy and the physical 
properties such as tensile and elongation in an alternative product. This 
is especially true of films being used for tape backings in the electrical 
industry where the tapes must stretch and drape in a certain manner to be 
acceptable for use. 
U.S. Pat. No. 5,017,637 discloses fire-retardant thermoplastic compounds 
that are chemically crosslinked, comprising 5-60% olefinic copolymers, 
1-15% organopolysiloxane, and 20-85% flame retardant. Preferred 
embodiments include a copolymer, and an additional elastomer or ethylene 
copolymer. The preferred elastomers are EP or EPDM copolymers. Ethylene 
vinylacetate is also disclosed. Metal oxide hydrates are used as the 
fire-retardant compound. 
U.S. Pat. No. 4,772,642 discloses a resin containing polyolefins, 
preferably polypropylene. Ammonium polyphosphate particles are used for 
flame retardance, and a melamine resin encapsulates the particles. 
EP Patent 274,888 discloses a flame retardant halogen-free elastomer 
composition containing greater than 50% inorganic filler. Addition of a 
coupling agent is not disclosed. 
EP Patent 391,336 discloses the use of a silane coupling agent and/or an 
olefinic synthetic rubber in a flame retardant composition of 
polypropylene and ammonium polyphosphate or melamine modified ammonium 
polyphosphate with one or more nitrogen-containing organic compounds. The 
organofunctional group of the silane can be vinyl, chloro, amino or 
mercapto. Vinyl trimethoxysilane, vinyl triethoxysilane and 
3-mercaptopropyl trimethoxysilane are preferred. Compositions with an 
olefinic synthetic rubber and without silane are also disclosed. 
JP Patent 04,139,241 discloses an olefinic resin blended with ammonium 
polyphosphate, a silane coupling agent, and olefinic synthetic rubber and 
a petroleum resin. An example of the silane is vinyl trimethoxysilane. 
Advantages of this compound are high electrical resistance and high bleed 
resistance. 
U.S. Pat. No. 5,130,357 discloses a flame retardant composition containing 
polypropylene as the major constituent, a silane coupling agent, and/or 
olefinic synthetic rubbers, ammonium polyphosphate (APP) or 
melamine-modified APP and one or more nitrogen compounds, and optionally 
polyethylene resin, crosslinking agent and thiophosphate. 
U.S. Pat. No. 4,808,474 and 4,769,283 disclose a pressure-sensitive 
adhesive tape backing having improved toughness comprising blends of 
crystalline isotactic polypropylene and compatible flexible polymers (in 
the former) or compatible ethylene containing polymers (in the latter), 
such polymers including EPDM and/or EVA. 
U.S. Pat. No. 4,985,024 discloses a biodegradable pressure-sensitive 
adhesive tape backing comprising such a blend combined with an unsaturated 
elastomer. 
U.S. Pat. No. 5,134,012 discloses a fixing tape for a disposable diaper 
comprising a plastics film layer, a polymer blend layer, and an adhesive 
layer. The plastics film layer may contain an EVA copolymer, and EP 
copolymer, or a combination thereof; the polymer blend layer contains two 
or more resins selected from EVA, EP, and polyethylene. 
U.S. Pat. No. 3,941,859 discloses EPDM polymers physically blended with 
polyethylene and ethylene vinyl acetate copolymers having improved tensile 
strengths. Use as wire and cable insulation is disclosed. 
However, these attempts to produce a halogen free film for the electrical 
industry, and especially for tape backings, have not been able to produce 
a halogen-free film with the required flame retardance and physical 
properties. 
The present inventors have found that films comprising ethylene vinyl 
acetate (EVA) copolymers and an elastomer selected from ethylene propylene 
(EP) and ethylene propylene diene monomer (EPDM) rubbers and an effective 
amount of flame retardant phosphorous-nitrogen containing intumescent 
fillers and an aminofunctional silane coupling agent has tensile 
stress-strain behavior such that the first derivative of stress with 
respect to strain is positive for the entire curve, and a curve showing a 
second derivative of stress-strain is negative over more than 50% of the 
curve. 
Further, such films will provide electrical tape backings having the feel, 
and handling properties of the most popular poly(vinyl chloride) backings 
with no halogen, which eliminates the release of toxic gases into the air, 
and also reduces negative environmental aspects from processing and 
disposal. 
SUMMARY OF THE INVENTION 
The invention provides a halogen-free, electrically insulating film 
comprising a resin component containing: 
a) from 0 to about 40 parts of a rubber selected from EP or EPDM rubber, 
b) correspondingly, from about 60 to about 100 parts of an ethylene vinyl 
acetate polymer, 
c) from about 40 parts to about 150 parts of ethylene diamine phosphate per 
100 parts of said resin component, and 
d) from about 0.5 part to about 5 parts of an amino-functional silane 
coupling agent, per 100 parts of said resin component, 
wherein a nonoriented film self-extinguishes in less than about 5 seconds, 
has an elongation at break of at least about 200%, a dielectric strength 
of at least about 1200 V/Mil, and stress-strain behavior such that a curve 
showing a first derivative of stress-strain is positive over the entire 
curve, and a curve showing a second derivative of stress-strain is 
negative over more than 50% of said curve. 
Insulating films of the invention are suitable for use as an electrical 
tape backing. Preferred electrical tape backings are halogen-free 
electrical tape backings comprising a resin component containing: 
a) from 10 to about 40 parts of a rubber selected from EP or EPDM rubber, 
b) correspondingly, from about 60 to about 90 parts of an ethylene vinyl 
acetate polymer, 
c) from about 40 parts to about 150 parts of ethylene diamine phosphate per 
100 parts of said resin component, and 
d) from about 0.5 part to about 5 parts of an amino-functional silane 
coupling agent, per 100 parts of said resin component, 
wherein a nonoriented film self-extinguishes in less than about 5 seconds, 
has an elongation at break of at least about 200%, a dielectric strength 
of at least about 1200 V/Mil, and the stress-strain behavior described 
above. 
The invention also provides electrical tapes comprising a halogen-free 
backing film, comprising a resin component containing: 
a) from 0 to about 40 parts of a rubber selected from EP or EPDM rubber, 
b) correspondingly, from about 60 to about 100 parts of an ethylene vinyl 
acetate polymer, 
c) from about 40 parts to about 150 parts of ethylene diamine phosphate per 
100 parts of said resin component, and 
d) from about 0.5 part to about 5 parts of an amino-functional silane 
coupling agent, per 100 parts of said resin component, 
wherein said tape self-extinguishes in less than about seconds, has an 
elongation at break of at least about a dielectric strength of at least 
about 1200 V/Mil, and a stress-strain curve as described above, and an 
adhesive coated on one major surface of said backing. 
All weights, percents, parts, and ratios herein are by weight unless 
specifically noted otherwise.

DETAILED DESCRIPTION OF THE INVENTION 
Compositions of the invention comprise a resin component containing at 
least one ethylene-vinyl acetate copolymer (EVA). Ethylene vinyl acetate 
copolymers useful in the films of the invention contain at least about 10% 
by weight vinyl acetate, preferably at least 15% by weight. The resin 
component may contain only ethylene vinyl acetate, or it may also contain 
a rubber selected from EP and EPDM rubbers; when such a rubber is present, 
the resin component may contain as little as 60 percent EVA copolymer. 
Useful rubber polymers comprise from about 50% to about 90% of ethylene, 
from about 10% to about 50% propylene, and from 0 to about 3% diene. 
Examples of suitable diene monomers include, but are not limited to, 
conjugated dienes such as isoprene, butadiene, 2,3-hexadiene, and the 
like, and nonconjugated dienes such as 1,4-pentadiene, 1,5-hexadiene, 
2,5-dimethyl-1,5 hexadiene, 1,4-hexadiene and the like; cyclic dienes such 
as cyclopentadiene, cyclohexadiene, dicyclopentadiene, 
3-methyltricyclo(5,2,1)-3,8-decadiene, and the like, and alkenyl 
norborenes such as 5-ethylidene-2-norborene, 2-methallyl-5-norborene, and 
the like. These polymers are easily prepared by well know solution or 
suspension polymerization techniques. 
Insulating films of the composition comprise an effective amount of 
ethylene diamine phosphate as the flame-retardant agent, such as that 
available commercially from Albright & Wilson. 
Insulating films of the invention also comprise an amino silane coupling 
agent. Useful amino silanes include, but are not limited to, 
N-beta-(amino-ethyl) gamma-aminopropyl trimethoxy silane and aminopropyl 
triethyoxy silane and trimethoxy silane. Films of the invention contain 
from about 0.05 part to about 5 parts amino-functional silane coupling 
agent, preferably from about 0.1 part to about 2 parts, per 100 parts 
resin component. 
Films of the invention may also comprise conventional additives such as 
reinforcing fillers, pigments such as carbon black, and TiO.sub.2, dyes, 
ultraviolet stabilizers, plasticizers, fungicides, extenders, waxes, 
antioxidants, and the like, in amounts known to those skilled in the art. 
Other useful fillers include fumed silica, calcium and magnesium 
carbonates, calcium and barium sulfates, aluminum silicates, and the like, 
which may be included in small amounts, such that they do not interfere 
with the physical properties required. 
Films of the invention are useful as insulative wire and pipe coatings, as 
insulative backings for multilayer films, and especially, as electrical 
tape backings. Such films would also be useful for various molded and 
extruded items such as shoe soles, shower curtains, kitchen ware and the 
like. 
The films of the invention are made by physically mixing the rubber, the 
ethylene vinyl acetate copolymer, and the ethylene diamine phosphate, 
along with any additives in a mill, mixer or extruder. The mixing 
conditions are not critical, and such processes are well known to one 
skilled in the art. 
Films of the invention have a stress-stain behavior such that a curve of 
the first derivative stress-strain relationship has a wholly positive 
slope. This is surprising, as most olefin-based films have at least some 
portion of the slope which is negative. Further, a curve of the second 
derivative shows that it is mostly negative. That means that these films 
do not have an inflection point below about 200% elongation. Electrical 
tapes backed with films with these characteristics demonstrate a vastly 
improved handling characteristic over the prior art halogen-free films; 
i.e., they approximate the stretch and "drape" characteristics of vinyl 
chloride backed electrical tapes. This is extremely critical for proper 
insulation and sealing of repaired cables and connections, as well as for 
acceptance by persons skilled in electrical maintenance and repair. 
Tapes comprising backings of the invention have an improved low temperature 
performance as compared to prior art poly(vinyl chloride) backings. PVC 
film becomes very stiff, exhibits a yield point and is brittle at the low 
temperature. The filled blend retains good elongation and mechanical 
properties even at temperatures of about -20.degree. C. Further, vinyl 
does not have a stress-strain curve with a wholly positive slope at such 
low temperatures, whereas films of the invention do have a stress-strain 
curve which retains a positive slope even at -20.degree. C. 
Electrical tapes of the invention have at least one side of the film 
backing coated with an adhesive. The adhesive may be any conventional 
adhesive known in the art, including but not limited to, natural rubber, 
thermoplastic elastomers, such as block copolymers, thermoset adhesives, 
acrylic adhesives, silicone adhesives and the like. The adhesive may 
further comprise such conventional additives as tackifiers, plasticizers, 
pigments, fillers, initiators, crosslinking agents, and the like, as 
desired. 
The following examples are meant to be illustrative and should not be 
construed as limiting the scope of the invention, which is defined only by 
the claims. One skilled in the art would be able to create variations 
which would be within the spirit of the invention. Comparative examples 
are indicated by the use of the letter "C" in front of the example number. 
TEST METHODS 
FLAME RETARDANCE 
Flame retardance was tested by the ASTM D1000 test method. This test 
involves wrapping a film strip around a wire with a 50% overlap and 
repeating with another film strip in the opposite direction. The wrapped 
wire is exposed to an open flame for 30 seconds. The flame is removed and 
the burn time of the film is measured. Desirable flame retardance would be 
exhibited by a material that does not begin to burn, or self extinguishes 
in less than 5 seconds. 
TENSILE TEST 
Tensile strength was tested by the ASTM D1000 test method. 
______________________________________ 
Glossary of Materials 
______________________________________ 
Elvax .TM. 470 
poly(ethylene vinyl acetate) copolymer; 
18% vinyl acetate; available from DuPont 
Epsyn .TM. 7506 
ethylene-propylene terpolymer; 77% 
ethylene; 5.5 C/100 C unsaturated; 
available from Copolymer 
LDPE low density polyethylene 1017; 
available from Chevron 
PP-PB amorphous polypropylene-polybutylene 
copolymer; available from Eastman 
LDX 314 experimental ethylene methyl acrylate- 
acrylic acid terpolymer; 
available from Exxon 
EVOH 27 poly(ethylene vinyl alcohol); 27% vinyl 
alcohol; available from EVALCO 
IFR 10 ammonium polyphosphate based 
flame retardant filler; 
available from Hoechst-Celanese 
IFR 23 ammonium polyphosphate 
flame retardant filler; 
available from Hoechst-Celanese 
Phoschek P40 ammonium polyphosphate based 
flame retardant filler; 
available from Monsanto 
Exolit 422 ammonium polyphosphate based flame 
retardant filler, 
available from Hoechst-Celanese 
EDAP ethylene diamine phosphate; 
available from Albright & Wilson 
DE83R decabromodiphenyl oxide 
flame retardant filler; 
available from Great Lakes Chem. Corp 
Solem 932 alumina trihydrate; 
available from J.M. Huber 
EVA85H antimony trioxide concentrate in 
poly(ethylene vinyl acetate); 
available from Laurel 
A0750 aminopropyltriethoxy silane; 
available from Union Carbide 
A151 vinyltriethoxy silane; 
available from Union Carbide 
A1100 aminopropyltrimethoxy silane; 
available from Union Carbide 
A1120 N-beta-(aminoethyl)-gamma- 
aminopropyltrimethoxy silane; 
available from-Union Carbide 
A1130 triamino-functional silane; 
available from Union Carbide 
A174 gamma-methacryloxypropyltrimethoxy 
silane; available from Union Carbide 
M8500 3-mercaptopropyltrimethoxy silane; 
available from Huls Petrarch 
Z6032 N-[2(vinyl benzyl amino)-ethyl]-3- 
aminopropyltrimethoxy silane; 
available from Dow Corning 
Lica 44 neopentyl(diallyl)oxy, tri(N- 
ethylenediamino)ethyl titanate; 
available from Kenrich 
Lica 97 neopentyl(diallyl)oxy, tri(m- 
amino)phenyl titanate; 
available from Kenrich 
L44/H 2,2(bis-2-propenolatomethyl)butanlato, 
tri(N-ethylaminoethylamino) titanate; 
available from Kenrich 
NZ44/H 2,2(bis-2-propenolatomethyl)butanlato, 
tri(N-ethylaminoethylamino) zirconate; 
available from Kenrich 
L97/H 2,2(bis-2-propenolatomethyl)butanlato, 
tri(m-amino) phenyl titanate; 
available from Kenrich 
NZ97/H 2,2(bis-2-propenolatomethyl)butanlato, 
tri(m-amino) phenyl zirconate; Kenrich 
Irganox 1010 hindered phenolic antioxidant; 
available from Ciba Geigy 
Irganox 1035 hindered phenolic antioxidant; 
available from Ciba Geigy 
______________________________________ 
EXAMPLES 
Examples of typical polymer blend compositions with and without the 
amino-functional silane coupling agent are provided by the formulations in 
Table 1. Compositions were mixed in a Brabender.TM. rheometer using a 
small batch mixing head with high shear paddles at 105.degree. C. for 5 
minutes until a uniform dispersion of the polymer and filler components 
was achieved. Blends were pressed between heated platens to form films. 
TABLE 1 
______________________________________ 
Example 1 
Materials (Parts) Example C1 
______________________________________ 
Elvax .TM. 470 80 80 
Epsyn .TM. 7506 
20 20 
EDAP 50 50 
A0750 0.15 -- 
Irganox .TM. 1010 
0.15 0.15 
______________________________________ 
The tensile properties of Example 1 and C1 films having a thickness of 
about 150 .mu.m to about 200.mu.m (6-8 mils) of Examples 1 and C1 are 
depicted in FIG. 1. As can be seen from the figure, there is dramatic 
improvement in mechanical properties for films containing the 
amino-functional silane. The yield point completely disappears, and the 
lower elongation of Example 1 is evidence of the improved adhesion between 
the filler and the matrix polymers. 
The shape of the curve for the composition of Example 1 more closely 
resembles the behavior of plasticized poly(vinyl chloride) (PVC) which is 
highly desirable for films used in tapes for the electrical industry. 
EXAMPLES C2 and 2-4 
Blends were prepared in the same manner as described previously except 
containing varying amounts of amino-functional silane. FIG. 2 demonstrates 
the effect of the amount of amino-functional silane on the mechanical 
properties for the following compositions listed in Table 2. 
TABLE 2 
______________________________________ 
Material Ex. 2 Ex. 3 Ex. 4 
Ex. C2 
______________________________________ 
Elvax .TM. 470 
80 80 80 80 
Epsyn .TM. 7506 
20 20 20 20 
EDAP 50 50 50 50 
A1100 0.3 0.6 1.0 0 
Irganox .TM. 0.15 0.15 0.15 0.15 
1010 
______________________________________ 
As addition of amino-functional silane increases, the shape of the 
stress-strain curve remains approximately the same although slight 
increases in tensile strength and reductions in ultimate elongation occur 
with higher silane contents. The stress-strain behavior of plasticized 
vinyl (PVC) film is shown for comparison of the relative shapes of the 
curves (Example C3). 
Compositions for several blends containing a phosphorous-nitrogen flame 
retardant (EDAP) and various coupling agents including a composition with 
no coupling agent were hot melt mixed and pressed into films as described 
previously and are listed in Table 3. 
EXAMPLES 3-5 AND C3-C5 
These examples were made similar to Example 1, i.e., with 80 parts 
Elvax.TM. 470, 20 parts Epsyn.TM. 7506, 50 parts EDAP, and 0.15 part 
Irganox.TM.1010. However, the types of silane coupling agent were varied. 
The Example numbers and types of silane are listed below in Table 3. 
TABLE 3 
______________________________________ 
Silane 
Ex 5 Ex 6 Ex 7 Ex C4 Ex C5 Ex C6 
______________________________________ 
A1100 1 
A1120 1 
A1130 1 
A174 1 
M8500 1 
Z6032 1 
______________________________________ 
Tensile stress-strain curves are shown in FIG. 3 for films of the 
compositions listed in Table 3 and film C1 shown in Table 1. The 
amino-functional silanes change the shape of the stress-strain curve 
dramatically compared to the vinyl, benzyl, mercapto and methacryl 
functional silanes. The Z6032 silane does contain an amino functional 
group, but it is centrally located within the molecule and, for stearic 
considerations, is not freely accessible to interact with the polymer. The 
primary functionality of this silane is vinyl. These non-amino silanes, 
including the Z6032, may have some reinforcing effect over compositions 
without silane, but not nearly the effect obtained with amino-functional 
silane coupling agents. 
The dry and wet dielectric properties and the flame retardance of these 
compositions with the addition of various coupling agents and without 
coupling agent are listed in Table 4. 
TABLE 4 
______________________________________ 
DIELECTRIC 
STRENGTH 
BURN TIME (V/mil) 
EXAMPLE Seconds DRY WET 
______________________________________ 
5 1 1653 537 
6 1 1534 518 
7 1 1361 541 
C4 1 1756 535 
C5 1 1856 542 
C6 1 1589 536 
C1 1 1327 522 
______________________________________ 
The dielectric properties of compositions using most types of coupling 
agents are improved over compositions without coupling agent. No advantage 
of amino-functional silanes, compared to other silanes, is evident here. 
Flame retardant properties are not noticeably affected by the addition of 
different types of silane coupling agents. Amino-silane coupling agents 
perform similarly to other silanes in dielectric properties and 
flammability tests of these compounds. 
Films of the compositions listed in Table 3 were exposed to electron beam 
radiation at a dose of 15 megarads. Tensile properties of irradiated 
samples are shown in FIG. 4 and burn time and dielectric strength of 
irradiated samples are shown in Table 5. 
TABLE 5 
______________________________________ 
DIELECTRIC 
STRENGTH 
(V/mil) 
EXAMPLE BURN TIME DRY WET 
______________________________________ 
5 1 1597 527 
6 2 1836 542 
7 2 1259 532 
C4 1 1940 523 
C5 1 1654 515 
C6 2 1359 543 
C1 1 1079 525 
______________________________________ 
Irradiation of these compositions changes the tensile properties by 
crosslinking the polymeric matrix, but the effect of the amino-functional 
silane on the tensile properties is still obvious compared to irradiated 
compositions containing no coupling agent. Although the curves are shifted 
together upon irradiation, close examination reveals that blends with 
non-amino functional silanes have an inflection point, a change from 
negative to positive second derivative of stress with respect to strain, 
below about 200% elongation. 
Blends containing amino-functional silane exhibit an inflection point after 
irradiation, which is characteristic of crosslinked materials, but this 
occurs at elongations higher than 200%. Tensile properties of irradiated 
films containing non-amino functional silanes do not show the 
reinforcement seen with amino-functional silane coupling agents. 
Irradiated samples containing silane coupling agents demonstrate 
improvements in dry dielectric strength over samples without silane 
coupling agents, and amino silanes appear to perform similarly to other 
silanes, as was noted in non-irradiated samples. Irradiation has no 
obvious effect on flame retardance or dielectric properties. 
Coupling agents with amino-functionality, other than silane coupling 
agents, do not demonstrate the dramatic improvement in tensile 
stress-strain behavior. Blends containing amino-functional titanates and 
zirconates are described in Table 6 and tensile properties of hot melt 
mixed and pressed films are shown in FIG. 5. 
COMATIVE EXAMPLES C7-C12 
These Examples were made similar to Example C1, i.e., with 80 parts 
Elvax.TM. 470, 20 parts Epsyn.TM. 7506, 50 parts EDAP, and 0.15 part 
Irganox.TM. 1010. However, these examples use amino-functional titanates 
and zirconates in place of amino functional silanes of compositions of the 
invention as coupling agents. The coupling agents are listed for each 
Example in Table 6. 
TABLE 6 
______________________________________ 
Ex. No./ 
Ex Ex Ex Ex Ex Ex Ex 
Ingred C1 C7 C8 C9 C10 C11 C12 
______________________________________ 
LICA 44 
0 0.3 
LICA 97 0.3 
L44/H 0.3 
NZ44/H 0.3 
H 0.3 
NZ97/H 0.3 
______________________________________ 
Addition of these non-silane amino-functional coupling agents reduces the 
elongation of the compositions and increases the tensile values somewhat, 
similar to non-amino silane coupling agents, but does not dramatically 
improve the tensile values or the shape of the stress-strain curve as does 
the amino functional silane coupling agents. 
COMATIVE EXAMPLES C13-C26 AND EXAMPLES 8 AND 9 
Compositions containing various P-N flame retardant fillers are listed in 
Table 7. The effect of 0.3 phr and 1.0 phr of an amino-functional silane 
on these compositions is also shown in FIG. 6. EDAP is the only flame 
retardant that demonstrates the desired improvement in stress-strain 
properties. The other systems show very little change in tensile 
stress-strain properties with the addition of amino-functional silane 
coupling agent. 
Most of the commercial phosphorous-nitrogen type flame retardants 
(including those tested) are composed primarily of ammonium polyphosphate. 
EDAP is an exception. EDAP has tri-hydroxyl functionality that imparts 
some level of acidity to this filler. Without wishing to be bound by 
theory, it is believed that this causes the EDAP to be more reactive than 
the APP compounds with the hydrolyzable groups of the silane. Infrared 
analysis was conducted on samples of EDAP, EDAP in EVA/EPDM and EDAP in 
EVA/EPDM with aminofunctional silane. The spectra indicate no chemical 
reaction between the EVA and the EDAP with or without the amino-functional 
silane. Hydrogen bonding would not be detectible as a chemical reaction. 
COMATIVE EXAMPLES C27-C36 
Films of flame retarded compositions that do not contain P-N type flame 
retardants were prepared that contain various types of silane coupling 
agents. These are described in Table 8 and the tensile properties of these 
films are shown in FIG. 7. The shape of the stress-strain curve is not 
affected by the different type of functionality of the silane coupling 
agent, although the addition of a silane of any type provides a small 
improvement in tensile properties when compared with the properties of 
compositions containing no silane coupling agent. 
TABLE 7 
__________________________________________________________________________ 
Example No. 
Ingredients 
Elvax .TM. 470 
Epsyn .TM. 7506 
EDAP 
IFR 23 
IFR 10 
A1100 
Irganox .TM. 
__________________________________________________________________________ 
Ex C1 80 20 50 -- -- 0.15 
Ex 8 80 20 50 -- 0.3 0.15 
Ex 9 80 20 50 -- 1 0.15 
Ex C13 80 20 -- 50 -- 0.15 
Ex C14 80 20 -- 50 0.3 0.15 
Ex C15 80 20 -- 50 1 0.15 
Ex C16 80 20 -- 50 -- 0.15 
Ex C17 80 20 -- 50 0.3 0.15 
Ex C18 80 20 -- 50 1 0.15 
__________________________________________________________________________ 
Ex. No. 
Elvax .TM. 
Epsyn .TM. Exolit .TM. 
Irganox .TM. 
Ingred. 
470 7506 P40 
IFR 24 
422 A1100 
1010 
__________________________________________________________________________ 
Ex C19 
80 20 50 -- 0 0 0.15 
Ex C20 
80 20 50 -- 0.3 0.15 
Ex C21 
80 20 -- 50 -- 0.15 
Ex C22 
80 20 -- 50 0.3 0.15 
Ex C23 
80 20 -- 50 1 0.15 
Ex C24 
80 20 -- -- 50 -- 0.15 
Ex C25 
80 20 -- 50 0.3 0.15 
Ex C26 
80 20 -- 50 1 0.15 
__________________________________________________________________________ 
TABLE 8 
__________________________________________________________________________ 
Ex. No. 
Elvax .TM. 
Epsyn .TM. 
SOLEM Irganox .TM. 
Ingred 
470 7506 932 DE83R 
EVA85H 
1010 A1100 
A151 
A174 
M8500 
__________________________________________________________________________ 
Ex C27 
80 20 60 -- -- 0.15 -- -- 
Ex C28 
80 20 60 -- -- 0.15 0.3 -- -- 
Ex C29 
80 20 60 -- -- 0.15 -- 0.3 
-- 
Ex C30 
80 20 60 -- -- 0.15 -- -- 0.3 
Ex C31 
80 20 60 -- -- 0.15 -- -- -- 0.3 
Ex C32 
80 20 -- 20 8 0.15 -- -- -- 
Ex C33 
80 20 -- 20 8 0.15 0.3 -- -- 
Ex C34 
80 20 -- 20 8 0.15 -- 0.3 
-- 
Ex C35 
80 20 -- 20 8 0.15 -- -- 0.3 
-- 
Ex C36 
80 20 20 8 0.15 -- -- -- 0.3 
__________________________________________________________________________ 
COMATIVE EXAMPLES C37-C40 AND EXAMPLES 10-13 
Compositions with a P-N type flame retardant and different matrix polymer 
materials were prepared and pressed into films. Table 9 shows these 
compositions and the legend states whether the matrix polymer is capable 
of forming hydrogen bonds. 
FIG. 8 shows the tensile stress-strain curves for these blends. The 
polymeric materials that are capable of forming hydrogen bonds demonstrate 
greatly improved mechanical properties with the addition of 
aminofunctional silane, i.e., elimination of a yield point and higher 
tensile values. The polymeric materials that are not capable of forming 
hydrogen bonds do not show this type of improvement with addition of 
aminosilane. Reduced elongation is evident in all blends containing silane 
coupling agent. Without wishing to be limited by theory, it is believed 
that the amino functionality of the silane provides dramatic improvements 
in mechanical properties for polymeric matrices capable of forming 
hydrogen bonds. 
The PVC films used widely in electrical tapes display excellent ambient 
stress-strain properties which can be an indication of the films handling 
behavior. Films of this invention have similar properties at room 
temperature, and also have superior low temperature stress-strain 
properties compared to PVC films. 
FIG. 9 shows ambient and low temperature stress-strain behavior for PVC 
film and low temperature stress-strain behavior for the material of 
Example 1. The shape of the Example 1 film shows no yield point and more 
closely resembles the ambient PVC behavior while the low temperature PVC 
curve has a yield point, very low elongation, and very high ultimate 
tensile strength. At low temperatures, films of this invention have 
handling characteristics superior to PVC. 
TABLE 9 
__________________________________________________________________________ 
Ex. No. 
Elvax .TM. 
Epsyn .TM. Irganok .TM. 
LDX 
Bynel .TM. 
PP- EVOH 
Surlyn 
Ingred. 
470 7506 EDAP 
A1100 
1010 314.sup.1 
3048.sup.1 
PB.sup.2,3 
LLDPE.sup.2 
27.sup.1,4 
9020.sup.2 
__________________________________________________________________________ 
Ex 10 
80 20 50 0 0.15 100 
-- -- -- -- -- 
Ex 11 
80 20 50 1 0.15 100 
-- -- -- -- -- 
Ex 12 
80 20 50 0 0.15 -- 100 -- -- -- -- 
Ex 13 
80 20 50 1 0.15 -- 100 -- -- -- -- 
Ex C37 
80 20 50 0 0.15 -- -- 100 
-- -- -- 
Ex C38 
80 20 50 1 0.15 -- -- 100 
-- -- -- 
Ex C39 
80 20 50 0 0.15 -- -- -- 100 -- -- 
Ex C40 
80 20 50 1 0.15 -- -- -- 100 -- -- 
Ex C41 
80 20 50 0 0.15 -- -- -- -- 100 -- 
Ex C42 
80 20 50 1 0.15 -- -- -- -- 100 -- 
Ex C43 
80 20 50 0 0.15 -- -- -- -- -- 100 
Ex C44 
80 20 50 1 0.15 -- -- -- -- -- 100 
__________________________________________________________________________ 
.sup.1 Capable of forming Hbonds 
.sup.2 Not capable of forming Hbonds 
.sup.3 Not able to make films with this material; no mechanical integrity 
.sup.4 Not able to make films with this material; materials formed 
crosslinked thermoset