Note: Descriptions are shown in the official language in which they were submitted.
CA 02211610 1997-07-28
WO 96~24487 PCI'~US96~0~809
IMPROVED PLASTIC/~IETAL LAMINATES
This invention generall,v relates to impro~ed plastic/rnetal l~rninql~s with improved adhesion to
various substrates. improved heal-sealability. and a lower Coefficient of Friction ("CO~"). The
improved plastic/metal l:lmin~ 5 of the presem in~ention also exhibit reduced breakaae rates and
suhst~nti:llly reduced flal;ing and dusting durina the manufacture of cables and other formecl
plastic/metal composite articles utilizina the plasticlmetal l~rnm~Ps of the present invention.
Additionall,v. the preSenl in~enlion relates IO plastic/metal composi~e articies or l~min~tPs that can
reasonably be expected to be installed and/or otherwise used as electrical commnnic-q~ions cables.
10 metaUplastic/metal lqmin~-Pc for potential use as electrical appliance housings. in heatina ducts. in
various automotive applications. etc.
In the mqnuf~rnlring of cables and other formed plastic/metal composite articles from various
l~minq-Pd articles involving one or more metallic l,qyers or :,ub~LI,lt~s having one or more layers or
coatinas of a thermnp~ ic pol,vmer material adhered thereto. an oftentimes controlling ~actor or
15 consideration governing their suitability for various end-use applications is the degree by which the
plastic/metal laminate can be shaped and formed and the degree of adhesion as between the various
polymeric and metallic Iqyers in such l:lmin~tPrl or composite articles.
One particularly useful application for plastic/metal l~min~iP,c of the present invention is in
electrical cables. In the art of ~hcigning and cùnsLIu~Li~lg electrical cables. especially telecommnnir~rion
20 cables such as rP~ cables. it is known to assemble insulated conductors or alass fibers in a core and
surround it by shield and jacketing co,l,pone..ls. The shield Cu""~u"~.lt is often referred to as "shield.
screen. shielding tape. or arm. oring tape."
In general. the process by which plastic/metal l~min~r~c (for example. shieldin_ or armoring
tape) are made into cables generallv consists of an unwind stand which delivers the plastic/metal
'5 laminate. typicallv having a width from 0.5 inch ( I .''7 cm) to 8.0 inches (20.32 cm). to a corrugator. lif
smooth finished cable is desired. the corrugator is bypassed). From the corrugator. the plastic/metal
laminate is forwarded to a preformer or a forming tray which starts the shaping of the laminate into a
tube. The preformed laminate is then torwarded to at least one forming die. at which point the laminate
is formed into a tube having an overlap seam. At the formin_ die(s), the core is fed inside the formed
30 plastic/metal tube. From the forming die(s). the plastic/metal tube containing the core is forwarded to at
least one sizing die which sizes the plastic/metal tube to the proper dimension of the desired cable. A
heating source can be used to promote the adhesion of the overlap seam. Next a jacketing resin is
extruded onto the plastic/metal tube. After the extrusion of the jacketing onto the plastic/metal tube. the
final cable is cooled in a water bath and is typically wound on a coil. Depending on final cable size and
3~ type of cable desired. the line speed of this cable fabncation process can range from 8 ft/min. (7.41
m/min.) to 300 ft/min (91.44 m/min).
CA 02211610 1997-07-28
W 096/24487 PCTrUS96/01809
In the present art. tvpically the contact surface energy of the plastic/metal laminate to the
surface of the preformer. formin die(s)~ and sizinQ die(sl is sufficient to cause biocicjn~ of the
plastic/metal laminate resultinQ in some jeri~ing motion ol' the plastic/metal laminate as it is pulled
throu~h the cable fabrication process. This blocking and jerkin~ motion occasionallv results in breaka~e
of the plastic/metal laminate. This blocking and resultinQ jerkinQ motion is believed to be due to tight
clearances of the forming and sizing dies and the typicall,v high COF of the plastic/metal l ~min~-eS of the
present art. Because of the s~hst:ln-i~l hiQh surt'ace contact energy as the plastic/metal laminate is pulled
throu~rh the cable fabrication process. the surtace of the thermoplastic polymer is siQnificantl,v abraded.
causin~ fiakinQ and dusting of the thermoplastic polymer. specifically around the preformer. forming
10 die(s). and sizing die(s), but more typicall,v after the sizinY die(s) The resulting dust and fiakes can
a~cum~lAt~ around the fabrication process~ promoting process downtime. Additionally. there is a
~;u-~ Jolldin~ increase in temperature of the sizing die(s) as the formed plastic/metal tube is pulled
throu_h the sizin~ die(s).
In order to lessen the abrasion. fiaking, dustin~. die tG,..i,~.atu.G. and rate of laminate breaka_e,
15 a preferred mode of operation in the industr,v is to apply an oil lubricant to the surface of the
plastic/metal laminate prior to the preformin~ operation of the fabrication process. The intended purpose
of the oil lubricant is to lower the COF of the plastic/metal laminate surface con~:lrtinv the preformer,
forming die(s). and sizing die(s). However. the use of an oil lubricant can s-J~ ".~s snh~t~n~ y
reduce the adhesion p ~,.rv~--ance of the plastic/metal laminate to the jacketin~ co...~,v...,ut as well as
20 reduce the adhesion in the overlap seam. The use of an oil lubricant can also su-.-~,li---es cause ~uidance
problems be~ween the pld~lic/llleldl laminate and affected process surfaces.
Thus. there is a need in industry for plastic/metal l~min~r~c that exhibit reduced rates of
breaka e. exhibit reduced fiaking and dustin~. maintain or increase adhesion to jacket components. and
maintam or increase adhesion in overlap seams while elimin~in~ or s~hst~n~ ly reducing the amount of
'5 oil lubricant needed durin~ m:lnllf~r-llre into articles such as electrical cables.
The present invention suhs~n-i:~lly solves the problems of. abrasion. fiaking. dustinv, and
breakage of plastic/metal l:~min~ s (for example, plastic coated cable shieldinQ tapes) dunn_ the shaping
and forminv of these i~rnin~ s into cables and other formed plastic/metal articles while sl~hct~nri~ll,v
30 reducin~ or ellmin~in~r the need to use an oil lubncant. In ~eneral. Applicant has t'ound that these
problems are substantially solved by m~vli/vldtillv into the plastic la,ver of the plasticlmetal laminate. a
sufficient amount of embosser to sl~hs-~n~i~llv reduce the coefficient of friction of the laminate and to
emboss the surface of the plastic laver. When formed and incu.iJu-dled into plastic/metal composite
articles such as electrical cables. the plasticlmetal l~min~-~c of the present invention also exhibit
35 improved heat-sealability and adhesion to outer jacketing co...i)vnents.
2,Z_I-r CA 02211610 199i-07-28
kccordingly, in one aspect the present invention is a plastic/metal laminate comprising a
metallic substrate and at least one surf~ce layer adhered to said substrate either directly or via an
intermediate polymeric layer or layers; said surface layer consisting essentially of a base adhesive
polymer or blend of polymers and an amount of embosser sufficient to subst~ntially lower the coefficient
5 of friction of the laminate and sufficient to emboss said surface layer.
In another aspect, the present invention is a more finished plastic/metal composite ~rticle, such
as an electricai or communication cable, cclllpli~ing a core of at le~st one insulated conductor or glass
fiber, a shield surrounding said core, and n outer plastic jacket surrounding and adhered to said shield,
said shield comprising: a metallic substrate; a surface layer adhered to said metallic substrate either
10 directly or via n int~rrnef~ polymeric layer or layers; said surface layer consisting essentially of a
base adhesive polymer or blend of polymers and an embosser, wherein said shield exhibits a greater
bond strength to said outer plastic jacket relative to a similar shield differing only by the absence of
embosser in said shield, and wherein said shield exhibits greater helt-seal values relative to a similar
shield differing only in the absence of embosser in said shield.
Figure 1 is a graphical representation of he~t sealability testing results for embodiments of the
present invention.
In one embodiment, the present invention is a monolayer or multilayer thermoplastic adhesive
system. Adhesive systems of the present invention contain at least one layer consisting essentially of a
base adhesive resin and an amount of embosser sufficient to lower the coefficient of friction ("COF") of
the adhesive system and sufficient to emboss the adhesive system. Generally, adhesive systems of the
present invention have a thickness of from 0.1 mil (2.54 ,um) to 5 mil (127 llm). Preferred are adhesive
systems with a thickness of from 0.2 rnil (5.08 llm) to 5 mil (127 Ilm), and more preferred are adhesive
systems with a thickness of from I mil (25.4 llm) to 2.5 mil (63.5 llm).
Another embodiment of the present invention is a plastic/metal laminate formed by applying
. 25 adhesive systems of the present invention to one or both sides of a metallic substrate in the form of a
strip or tape. The adhesive systems are applied via techniques well known in the art (for example,
extrusion coating or lamination). Generally, plastic/metal l~min~ s of the present invention have a
thickness of from 2 mil (50.8 llm) to 25 mil (6~5 llm), and preferably, from 4 mil (101.6 llm) to 15 mil
(381 ,Lm).
Yet another embodiment of the present invention is a composite structure ~,~""l" ;~;"~ a core
component, a shield component surrounding the core, and an outer thermoplastic jacket component
surrounding and adhered to the shield component, wherein the shield component consists essentially of a
plastic/metal laminate of the present invention.
Adhesive systems of the present invention must be c.~pable of adhering to both the metallic
substrate of the plasticJmetal laminate and the jacketing component of any composite article into which
the laminate may be incol~ol~.tcd. In a multilayer adhesive system the outer or surface layer (that is, the
~E~o~ S~EET
, 42,227-F CA 02211610 1997-07-28
.
Iayer to be-adhered to the jacketing component) must cont~in the requisite sufficient amount of
embosser. In a
~':
~' .
A~AE~ID~D ~1 IEET
42,227-r CA 02211610 1997-07-28
multilayer adhesive system, layers other than the surface layer do not necessarily contain embosser and
may comprise either the same or a different base adhesive resin than the surface layer.
Thermoplastic polymers suitable for use in the base adhesive resin of the present invention
("base adhesive polymers") are generally those known in the art of producing l~min~t~S useful for
5 m~nllf~et11ring commllnic~ion cables. Preferred base adhesive polymers include the known normally
solid random copolymers of q major proportion of ethylene with a minor proportion (for example,
" typically from l to 30, preferably from 2 to 20, percent by weight based upon the weight of such
copolymer) of an ethylenically unsaturated carboxylic acid monomer. Specific examples of such
suitable ethylenically unsaturated carboxylic acids (which term includes mono- and polybasic acids, acid
anhydrides, and partial esters of polybasic qcids, as well as the various metallic salts thereofl are qcrylic
acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, itaconic qcid, maleic anhydride, mono-
methyl maleate, monoethyl maleate, monomethyl fumarate, monoethyl fumarate, tripropylene glycol
(_ mono-methyl ether acid maleate. or ethylene glycol mono-phenyl ether acid moleate. The carboxylic
acid monomer is preferably selccted from the alpha/beta-ethylenically unsaturated mono- and
lS polyc rboxylic acids and acid ~nhydrides having from 3 to 8 carbon atoms per molecule and partial
esters of such poly carboxylic acid wherein the qcid moiety has at least one carboxylic acid group and
the alcohol moiety has from l to ~0 carbon atoms. Such copolymers may consist essentially of ethylene
and one or more of such ethylenically unsaturated acid or anhydride commoners or can also cont~in a
small amount of other monomer copolymerizable with ethylene. Thus, the copolymers can contain other
20 copolymerizable monomers including esters of acrylic acid, methacrylic acid and the like. Random
copolymers of such type and methods of making them are readily know in the art.
Other thermoplastic polymers suitable for use in the present invention include the known olefin
polymers which are, as a general rule, the ethylenic olefin polymers such as, for example, the various
known ethylene homopolymers (for example, ultra low, linear low, low, medium, and high density
. 25 polyethylene's having a density range of 0.82 to 0.96 g/cm'), copolymers having a major proportion of
ethylene with a minor proportion of known copolymerizable monomers such as higher (for example, C3
to C12) alpha-olefins, ethylenically unsaturated ester mf~nomers (for example, vinyl acetate, ethyl
acrylate, etc.), and graft modified versions of such ethylenic homopolymer and copolymer (for example,
grafted with acrylic acid, maleic anhydride, etc.). Olefin polymers, copolymers of such type and
chemically modified olefin and or copolymers of such type and methods of making them are readily
known in the art.
In one embodiment of the present invention, the base adhesive resin is a blend of (a) a random
copolymer of ethylene with an ethylenically unsaturated carboxylic acid monomer with (b) at least one
ethylenic olefin homopolymer and a copolymer of an ethylenic olefin polymer resin which is not a
random ethylene/unsaturated carboxylic acid copolymer. Preferably, the base adhesive resin comprises
A~EI'~5ED SHEET
~ 42,227-~ CA 02211610 1997-07-28
.
from S percent to 95 percent of (a), more preferably from 50 percent to 95 percent, and most preferably
from 65
-4a-
A,~E~ ED SHEET
~2,~27-r CA 02211610 1997-07-28
percent to~5 percent, based on the weight of the base adhesive resin. Preferably the base adhesive resin
also comprises from O percent to 95 percent of (b), more preferably O percent to 50 percent~ and most
preferably from S percent to 20 percent, based on the weight of the base adhesive resin.
Further, it should be understood that when "random copolymers of ethylene with an
5 ethylenic~lly unsaturated carboxylic acid" are referred to it is intended to include therewith the known
partially or fully neutralized versions thereof, which are commonly refereed to in the art as "ionomers".
Further still, it should be understood that when " ethylenic olefin homopolymer or a copolymer of an
ethylenic olefin polymer resin which is not a random ethylenetunsaturated carboxylic acid copolymer" is
referred to, it is intended to include ethylenic olefin polymers that may be modified by copolymerization
10 or graft copolymerization techniques employing an ethylenically unsaturated dicarboxylic acid
anhydride or anhydride precursor, esters of ~n ethylenically unsaturated dic rboxylic acid and rubber
modified derivatives thereo~
_ Generally, embossers useful in the present invention are otherwise known in the art as organic
or inorganic fillers. Embossers suitable for use in the present invention are desirably substantially
noncompatibilized, chemically-inert, and insoluble in the base adhesive polymers. Being non-
compatibilized refers to a substantial lack of chemical (for example polymeric) linking or bonding with
the base adhesive polymers and preferably such a lack with respect to any other substance in the film.
Being chemically inert refers to a substantial inabiliy to dissolve in the base adhesive polymers, or
preferably, any other components in the base adhesive resin. Being insoluble refers to a substantial
inability to dissolve in the base adhesive polymers to an extent such that the physical integrity of the
embossed surface is substantially m~;nt:~inefi
The amount of embosser must be sufficient to substantially lower the COF of the plastic/metal
laminate ~nd to emboss the surface of the plastic/metal laminate. By embossing the surface of the
plastic/metal laminate, it is meant that there are bosses on the surface ranging in height from l/lOOth to
1/4th of the thickness of the adhesive layer(s). Larger bosses result in too rough of a surface and
adversely affect film strength and other properties. Smaller bosses are generally less effective in
reducing the COF of the plastic/metal laminate. Surface embossing was herein evaluated by measuring
the difference in contact measurement of the thermoplastic polymer as defined in ASTM D374 and
weight measurement of the thermoplastic polymer as defined in ASTM E252.
Preferably, the surface layer contains from 0.1 weight percent to 16 weight percent of embosser,
more preferably from 2 weight percent to 16 weight percent, and most preferably from 4 weight percent
to 8 weight percent.
Examples of organic embossers suitable for use in the present invention include particulated
polyester, polytetrafluoroethylene ("PTFE"), nylon, polystyrene, high-impact polystyrene ("HIPS"),
styreneacrylonitrile ("SAN"), acrylonitrile-butadiene-styrene ("ABS"), polycarbonate, etc. Suitable
inorganic embossers include particulated graphite, mica, chalk, calcium sulfate, calcium silicate, calcium
A~.lEl'~GL3 SH~ET
~2, 2,-~ CA 02211610 1997-07-28
carbonate, t~icum, bentonites, barytes, kaolin, mlan~inm qlllminllm silic~tes, magnesium silic~te,
mineral colloids, pyrophylite, serites, silicas, terra alba, etc. Preferred embossers are non-compatibilized,
non-hygroscopic and non-microporous forming in the base adhesive polymers. A most preferred
embosser is mica, which has the ability of not only effectively imparting a uniform embossed surface to
5 the plastic/metal laminate, but also to irnprove the adhesion properties of the plasticlmetal laminate.
By substantially lowering the COF of the plasticlmetal laminate, it is meant that both the
resulting static or starting COF and resulting kinetic or slidina COF are lower than the static COF and
kinetic COF of an ~scçnti~lly identical plasdc/metal laminate differing only by the absence of any
embosser. The static and kinetic COFs of the plastic/metal laminate were measured using a modified
10 ASTM DlS94 (See Example I). Preferably, the static COF of the plastic/metal laminate is at most 0.40,
more preferably at most 0.30, and most preferably, at most 0.70 as measured by the modified ASTM
D1894. Preferably, the kinetic COF of the plasticlmetal laminate is at most 0.40, more prefer~bly at
(_ most 0.30, and most preferably, at most 0.20 as measured by the modifled ASTM D1894.
Plastic/metal l~min~lr~s of the present invention exhibit improved adhesion. Adhesion
15 properties were evaluated by measuring the peel strength of the plastic/metal laminate pursuant to a
modified ASTM B736 (See Exarnple ~). The adhesion of the plastic/metal laminate to materials
typically found in jacketing components was measure using a modified ASTM 1876 (See Exarnple V).
Further, it should be understood that when improved adhesion is referred to herein, it is meqnt that the
adhesion is improved relative to the adhesion observed when utilizing essentially identical plastic/metal
l~min~ c or composite articles differing only by the absence of embosser.
Preferably, the adhesive bond strength between layers of a multilayer adhesive system of the
present invention is at least 5 Ibs/in, (89.29 ~Lm) more preferably at least 8 Ibs/in (142.86 kg/m), and
most preferably at least 12 Ibs/in (214.30 kg/m) as measured by the modified ASTM B736. Preferably,
the adhesion between a coating layer (that is such as an outer inc~ in~ jacketing layer in an electrical
C-'! '~5 cable) and plastic/metal l~min~t,oc of the present invention is at least 8 Ibs/in (142.86 kg/m), more
preferably at least 10 Ibs/in (178.58 kg/m), and most preferably at least 15 lbs/in (267.87 kg/m) as
me sured by the modified ASI~I 1876.
The thickness of metallic substrates (for example, sheets, strips, foils, etc.) employed in the
present invention is not critical. Foils less than 1 mil (25.411m ) may be used as well as relatively thick
sheets. Typically, metallic substrates have a thickness of from 3 mil (76.2 llm) to 25 mil (635.00 ~Lm),
and preferably from 4 mil (101.60 llm) to 15 mil (381.00 ~Lm). The metallic substrate can be composed
of a wide variety of metallic materials such as, for example, aluminum, alllminllm alloys, alloy-clad
aluminum, copper, surface modified copper, bronze steel, tin free steel, tin plate steel, alumini7.ofi steel,
aluminum-clad steel, stainless steel, copper-clad stainless steel, copper-clad low carbon steel, terne-plate
steel, galvanized steel, chrome plated or chrome tre~ted steel, lead, magnesium, tin and the like. Such
metals can, of course, be surface treated or have conversion coatings on the surface thereof if desired.
AME~ 3 SltEET
~ ~2,'27-- CA 02211610 1997-07-28
,
Particularly preferred metallic substrates for use herein include those composed of chrome/chrome oxide
coated steel (also commonly referred to in the art as tin-free steel), stainless steel, aluminum, and copper.
Adhesive systems of the present invention c n be ~pplied to the metallic substrates in any
convenient fashion which may be desired. For exarnple, conventional extrusion coating techniques may
5 be employed to apply the adhesive system to the chosen metallic substrate. Alternatively, conventional
film lamination techniques c n ~Iso be suitably employed to adhere an adhesive film system to the
desired metallic substrate. Also, a combination of conventional coextrusion and film lamination
technologies can be employed. For example, it may be desirable to first extrude or coextrude an
adhesive system as a film and laminate the f1lm to one or two surfaces of a metallic substrate.
1 0 EJY~MPI,ES
The present invention is further illustrated by, but is not to be understood as being in any way
limited to, the following examples. In the following examples, all parts and percentages are based on
~_ weight unless otherwise indicated
E.~ample I
In this example, 1.6 mil (40.61 ~tm) thick monolayer adhesive films were created usin, a
conventional blown film process. The adhesive film contained a blend of base adhesive resin and
Mic~fil 10 (a blend containing high density polyethylene and 40 weight percent mica, available from
DuPont Canada). The base adhesive resin was a blend of a random ethylene/acrylic acid ("EAA")
copolymer and an olefin polymer. The EAA copoLymer contained 6 weight percent acrylic acid based
upon the weight of the copolymer and had a melt index of 5.5. The olefin polymer used was either a
polyethylene having a melt index of 5.5 and a density of 0.916 g/cm; ("LDPE- 1 ") or a polyethylene
having a melt index S.0 and a density of 0.958 glcm' ("HDPE-I"). The amounts of EAA, LDPE- I,
HDPE- I, and Micafil 40 used in various samples are shown in Table I.
The various film samples were lAmin~r~d to one side of a 7.5 mil (190.511m) thick sheet of
f -)5 ~IIIminllm. In the preparation of such sarnples, the indicated monolayer film was l~min:~r~d by
preheating the metal for one minute in a circulating air oven heated to'300~F (148.89~C) and by then
pulling the preheated metal sheet and the indicated monolayer film through a set of rubber nip rolls. The
resulting laminate was then post heated for one minute in a circulating air oven he~ted to
300~F (148.89~C) The resulting post heated laminate was allowed to equilibrate in 73~F (22.78~C) air
having 50 percent relative humidity for at least 12 hours before any testing was done.
The resulting laminate samples were cut using a template into 2.75 inches (6.99cm) by 4.00
inch (10.16 cm) pieces, with the larger dimension in the machine direction. r ~3min~,o samples were
subjected to coefficient of friction (COF) testing in accordance with ASTM D1894 (except that a five-
inch per minute crosshead speed, a 2000 gram load cell, a #7 high luster stainless steel plate, and a l kg
sled are employed, conditioning is at least 12 hours in 50 percent relative humidity air at 73~F (22.78~C),
t'D~3 S~,EEr
~2,227-F CA 02211610 1997-07-28
- TABLEI
%
* % ~o % Mic fil40Static Kinetic
Sample # E~A LDPE-I HDPE-I COF COF
control91.005.00 0.5429 0.5257
I- 1 40.00 56.00 0.3320 0.31'70
I-2 67.20 16.g01'~.00 0.'73130.~099
I-3 60.80 15.20 20.00 0.2005 0.1696
I-~ 53.80 ?5 ~0 12.00 0.1757 0.1518
I-5 53.20 '~.80 20.00 0.1796 0.1532
I-6 46.20 19.80 30.00 0.1419 0.1289
C I-7 55.20 10.80 30.00 0.1428 0.1359
I-8 79.005.00 12.00 0.3400 0~ 150
1-9 71.00~ .00 20.00 0.~727 0.2509
I-10 61.005.00 30.00 0.1940 0.1657
I- 11 94.00 2.00 0.45200. l 15~
I-12 84.00 11.00 0.~300 0.3150
~-13 76.00 20.00 0.2795 0.~57
* The balance of the film c~ po~;~ion contained ~pproximately equal weight
percents of anti-blocking ageni and heqt stabilizing/antioxidant agent.
and testing is performed on at least 5 test specimens) at standard constant laboratory conditions. The
(~ results of COF testing are shown in Table I.
A control sample was created and tested in the same way as the above examples except that no
mic~ was incorporated in the adhesive film used to make the 17lmin~t~s
The results in Table I show that larninates utilizing relatively hi"h levels of hi~,h density
polyethylene exhibit reduced COF values relative to COF values exhibited by the control (Sample I-l vs
control). However, the results in Table I also show that the addition of rnica in sample laminates results
in more 5i~,nific~nt reductions in COF values.
Example II
T ~min~tt-s were prepared in the same manner as the l~min~tes in Example I. In addition to the
olefin polymers used in Example I (that is, LDPE-1 and HDPE- 1), an additional low density
polyethylene, having a melt index of 1.9 and a density of 0.925 g/cm~ (''LDPE-2"), was used. The
l~min:~tlos were cut
-8-
A;I~'E, 'r'.rn ~'IE-~T
~2,,~7-F CA 02211610 1997-07-28
- TABLE II
PeaL~Average
% Heat Heat
% % % % MicafilSeal Seal
Samvle # E.~A LDPE-I LDPE~-2 HDPE-I 40 (kg/m)
control 91.00 5.00 150.36 112.76
II-l 40.00 56.00 18.54 17.45
II-2 67.~0 16.80 12.00 103.43 60.41
II-3 60.~0 15.'0 20.00 96 15 46.27
II-4 5~.~0 25.70 12.00 73.27 35.88
II-S 53.20 2'2 80 20.00 89.70 37.20
rI-6 ~O.OQ ~4.00 2.00 17.84 17.1~
II-7 40.00 44.00 12.00 7.32 24.66
II-8 40.00 36.00 20.00 31.56 30.75
II-9 61.005.00 30.00 42.93 37.61
II-I0 94.00 ~2.00 101.~4 86.02
II-I l 84.00 12.00 73.74 49.77
II-12 76.00 20.00 167.94147.94
x The balance of the film composition contained approximately equal weight percents of anti-
blocking agent ~nd he -t stabilizing/antioxidant agent.
into samFles that were I inch (2.54cm) wide by 6 inches (15.24cm), with the larger dimension in the
machine direction.
Samples were subjected to 90~ heat sealability testing in accordance with ASTM B736 (except
that a 12-inches per minute crosshead speed, a 25 kilograms load cell, a he~t seal temperature of
300C F (148.89~C), a heat seal pressure of 40 psig (275790.4 Pascals), a dwell time of 2 seconds are
employed, conditioning is at least S minutes in 50 percent relative humidity air at 73~ F (22.78~C), and
testing is performed on at le st 5 test specimens) at standard laboratory conditions.
For comparison purposes, a control sample was created and tested in the sarne manner as the
other samples. The control did not contain any HDPE-I or Micafi1 40.
The heat sealability testing results for each sample are shown in Table II.
The results in Table II show that the addition of a relatively high Level of high density
polyethylene in a blend with EAA significantly reduces the adhesion properties of the sample as
A''''E~''n~3 S~E~
CA 02211610 1997-07-28
~2,227-F
: . -., .
~ _ , _, , _ .
compared to the control sample. Further still, it is seen that the addition of mica in blends with low
density and high density polyethylene can also ~l~h~lA~ ily reduce the adhesion properties of the
laminate. However, given the proper balance of mica and high density polyethylene in blends (for
example, via Mic~fil 40) with the r~ndom ethylene/carboxylic acid copolymer, signific~nt improvement
5 in he~t sealability adhesion properties can be obtained as compared to the control laminate (for example,
II-12 vs controlj.
F,Y:~m~le III
Samples were prepared and tested in a manner similar to the samples in Examples I and rI.
However, the ~dhesive film used to prepare the samples was a 2.3 mil (58.421lm) thick two-layer
10 adhesive film with each layer being of equal thickness. The adhesive film was prepared by a
conventional cast film process as opposed to a blown film process. For comparison, a control sample
was prepared using a 2.3 mil (58.42~Lm) thick monolayer film. Each sample in Example m had one
layer contacting the metal having the same co~ osition as tbe control. The composition of the other
layer (surface layer) in each sample is shown in Table m. The samples were tested in the same manner
15 ns the samples in E,xamples I and II and the test results are also shown in Table III.
~' , ' .
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42,227-F CA 02211610 1997-07-28
T~RJ F. rrl
PeakAverage
% Heat Heat
* % % % Mic~filStaticKinetic Seal Seal
Sample ~ EA~ LDPE-I HDPE-I 40 COF COF ~m~. (k~/m)
control91.00 5.00 0 7834 0.7386 273.23116.43
III-l 45.60 30.40 20.000.1900 0.1134 170.72141.08
III-2 57.60 38.40 0.6150 0.6064 237.87140.19
m-3 45.60 30.40 20.000.3Q15 0.3440 118.04 92.33
III-4 57.60 35.10 0.4375 0.2113 116.26101.~5
m-s 9l.OO 5.00 0.4235 0.4356 263.941~1.61
III-6 45.60 38.40 12.000.2682 0.2764 159.29110.54
III-1 16.00 20.000.'~9340.'~595255.01233.~3
III-8 45.60 38.40 12.00 0 4398 0.3788 191.26 88.93
III-9 72.33 10.46 13.210.1900 0.1700 239.30179.47
III-10 51.41 24.38 14.210.1200 0.1080 202.33160.19
* The balance of the surface layer composition contained approximately equal weight percents of anti-
blocking agent and he ~t stabilizin~/antioxidant agent.
Ex~ le IV
Two sets of samples were prepared in the same manner as the samples in Exarnple m. The
C samples in one set had a thickness of 1.6 mil (40.64 ~Lm) and the s~rnples in the other set had a thickness
of 2.3 mil (58.42~Lm). Each set of samples cnn~ined samples made in.accordance with both Sample III-
S controi and Sample m-7. The samples were cut into 1 inch by 6 inch pieces with the larger dimension in
the machine direction.
The samples were subjected to heat sealability testing in accordance with the same modified
ASIM B136 of Example m (except that heat seal temperatures of 200~F (102.22~C), 250~F
(121.115~C), 300~F (148.89~C),350~F (118.885~C), and 400 ~F (204.44~C) were employed). The
results of these tests are depicted graphically in Figure I. From the resurts depicted in Figure 1, it is seen
that a substantial improvement in heat sealability is achieved at low heat sealability temperatures. The
results in Figure 1 also show that the thickness of the samples had very little, if any, effect~
AIUEI'1~ 3 S,-15~T
' 42,227-~ CA 02211610 1997-07-28
.
Example ~
Samples were prepared in the same manner as the sarnples in E.xample m except in that the
two-layer ~dhesive film had ~ total thickness of 1.6 mil (40.64 lam) inste~d of 2.3 mil (58.42~Lm). To
test adhesion to typical jacketing component m~t~ lc, these samples were ~_u~ sion molded to two
S different sets of 75 mil (1,905,tm) thick sheets of polyethylene to form composite structures. The first
set of sheets were made of a high density polyethylene (UC3479, available from Union Carbide) and the
second set of sheets were made of a medium density polyethylene (UC8864, available from Union
C~rbide). Both sets of sheets also contained approximately 2.6 weight percent carbon black.
In the compression molding operation to form these composite structures, a platen press was
10 employed. The laminate sarnples were placed in contact with the sheets in the press and coul~ ion
molding WaS accomplished at 230~C ~nd 15 psig (103421.4 P.~sc31s) for three minutes. The resulting
composite structure was then cooled to room temperature in the platen press, removed from the press,
and subsequently cut into L inch (25 cm) wide by 6 inch (15.24 cm) strips with the larger dimension in
the machine direction.
Some of the resulting strips were then subjected to 180~ peel with backing plate testing in
accordance with ASI'M D 1876 (except that a two-inch (5.08cm) per mlnute crosshe~d speed, a 25
kilograms load cell is employed, conditioning is for 12 to 48 hours in 50 percent relative humidity air at
73~E: (22.78~C), the bonded and unbonded lengths of the polymer layer are 2.5 inches ( 6.35 cm) and 0.5
(1.27cm) inches respectively, and testing is performed on at least 3 test specimens instead of ten). Other
20 strips were immersed (that is, "aged") in water at 140~F (60~C) for 7, 30, 60 and 120 days, allowed to
equilibrate and dry in 50 percent relative humidity, 73~F (22.~8~C) air, overnight and then were also
subjected to the aforementioned 180~ peel test.
E~or col,-pdlison purposes, a control sample was prepared and tested in the same manner as the
other samples except the adhesive film used was a 2.3 mil (58.42~n) thiclc monolayer film.
The peel testing results for each sample are shown in Table V-A for the HDPE-2 sheets and in
Table V-B for the MDPE sheets. As can be seen from the results in Table V-A and Table V-B, the
Exarnples of the present invention exhibit improvement in aged adhesi'on.
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42,227-~ CA 02211610 1997-07-28
.
TABLE V-A
HDPE JACKET BOND ADE~ESION (kg/m)
%
* % % Micafil peel peel peel peel peel
Sample ~ EAA LDPE-I 40 initial 7days 3()davs ~Q~ 120 davs
eontrol 91.005:00 13.4616.1217.03 16.91 17.00
V-A-l 75.60~.40 12.00 11.5820.6520.9Q 20.g9 20.,~0
V-A-2 58.805 10 12.00 11.6818.0819.15 18.67 19.00
~_ * The balance of the surface layer composition contained approximately equal weight percents anti-
bloeking agent and heat stabilizing/antioxidant agent.
TABLE V-B
MDPE JACKET BOND ADHESION (kg/m)
%
* % % ~Iicafil peelpeel peel peel peel
S~m~le # ~ LDPE-I ~0 initial 7d~vs30davs60 davs 120 davs
control 91.00 5.00 13.77 15.39 16.29 16.27 16.20
V-B-1 75.60 8.40 12.0011.9219.71 21 81 21.83 21.80
V-B-2 58.80 25.20 12.0012.3518.49 18.g8 18.33 18.25
* The balanee of the surfaee layer composition contained approximately equal weight percents anti-
blocking agent and heat stabilizing/antioxidant agent.
Ex~mrle Vl
In this example, l~min~s were prepared in the same manner as Example m. The resulting
l~min~ s were then slit to a 1 11/16 ineh (4.29 em)width tape and were shaped and formed into
10 electrieal and or eommunieation cables using a conventional eable manufacturing process as described in
this applie~tion. The l~min~r~s used to make the eables are shown in Table VI-A and some resulting
cable processing data are shown in Table VI-B.
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- 42,227-r CA 02211610 1997-07-28
~ TABLE Y~-A
LA~vI~ATES USED TO MAKE CABLES
%
* % % ~o MicafilStaticKineticlaminate
Sample # ~ ~DPE-l HPPE-I 40 COF COF surface
control91.005~00 0.78340.7386 smooth
VI-1 57.60 35.-~0 0.41360.2814 smooth
VI-2 58.80 25.20 12.000.27000.2800embossed
VI-3 67.20 16.80 12.000.32000.2400embossed
VI- l 76.00 20.000.26000.2200embossed
* The balance of the surface layer composition contained .qpproximately equql weight percents
(_ anti-blocking agent and heat stabilizinglantioxidant qgent.
From the results in Table VI-B, it is seen that sllhst~nti~i improvement in the fabrication of
plastic/metal l~min7lr~ into electrical and/or communication cables can be ~chieved with laminates of
the present invention.
While the present invention has been herein illustrated by reference to particular embodiments
5 and examples thereof, such fact is not to be understood as in qny way limiting the scope of the present
invention.
C
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TABr F~. Vl-B
PROCESSING DATA FOR
LAl~NATES USED TO MAKE CABLES
flaking ~c
c ~ble lineuse of dusting att~pe bre3ks atfinal temp
speed oilforrners & ~i~weld point(~C) at sizinC die
Sample # meters/min.Iubricant
control 40 no yes yes 29.44
no yes yes 30
no yes yes 31.11
control 40 yes yes yes ?5
yes yes yes ''5.56
yes yes yes ~6.1 1
VI- 1 40 no yes no 27.7g
no yes no 27.7~
. 60 no yes no ~.33
- VI-2 40 no no no '7~.~9
no no no ~7.2~
no no no 77. _
VI-~ 40 no no no ''6.67
no no no 16.67
no no no 26.67
VI-4 40 no no no 27.22
A!,~C~lr'E3 SH~ET
