United States Patent (19)
`Campbell
`
`11
`45
`
`4,327,248
`Apr. 27, 1982
`
`54 SHIELDED ELECTRICAL CABLE
`75 Inventor:
`Larry J. Campbell, Kent, Ohio
`o
`73) Assignee: Eaton Corporation, Cleveland, Ohio
`21 Appl. No.: 194,317
`22 Filed:
`Oct. 6, 1980
`51) Int. Cl. .................................. ............. H01B 7/18
`52 U.S. C. .................................... 174/107; 156/203;
`58 Field of
`0.17/36. 17.9
`...g R
`of io, Rio Dios Rio, or
`110 N, 110 PM, 122 G; 428/461; 156/203, 218,
`280, 244.13, 244.19, 250, 344
`Ref
`Cited
`eferences Ute
`U.S. PATENT DOCUMENTS
`3,233,036 2/1966 Jachimowicz ...................... 174/107
`3,272,912 9/1966 Jachimowicz ....
`... 174/107
`... 174/36.
`3,379,821 4/1968 Garner ..............
`3,551,586 12/1970 Dembiak et al. ................... 174/107
`
`w
`56)
`
`a 174/106 D
`on as sea
`3. 1/1972 Ed a a
`3,903,354, 9/1975
`ageforde .......................... 174/107
`3,943,271 3/1976 Bahder et al. .................. 174/102 D
`4,042,776 8/1977 Matsuba et al. ................ 174/110 R
`4,125,739 11/1978 Bow ...................................... 174/36
`Primary Examiner-Volodymyr Y. Mayewsky
`Attorney, Agent, or Firm-R. J. McCloskey; A. E.
`Chrow
`ABSTRACT
`57
`Tubing and electrical cable utilizing shields made from
`a flexible metal tape that has a cc
`facopolymer of
`a flexible metal tape that has a coating of a copolymer o
`ethylene with a monomer having 2. reactive carboxyl
`group bonded to at least one of its sides and to which
`coating is bonded an adhesive that is adapted to bond
`the coating to flexible or semi-rigid non-olefinic poly
`meric materials so as to provide such tubing and electri
`cal cable with improved flexibility and resistance to
`wrinkling or bending.
`s
`
`13 Claims, 3 Drawing Figures
`
`
`
`

`

`U.S. Patent
`
`Apr. 27, 1982
`
`4,327,248
`
`resa...strativitsassissist.
`222222222222222222222
`
`
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`2
`4. 26 Sd
`S SSSSS 2
`5-4 S7 S-5
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`8 S d
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`Sri
`S.
`s
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`
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`

`

`1.
`
`SHIELDED ELECTRICAL CABLE
`
`4,327,248
`2
`rigid non-olefinic polymeric materials in general are
`able to be effectively compounded for flame retardancy
`and remain more flexible than similiar compounds made
`from olefinic polymers, such as polyethylene and poly
`propylene, the present invention also provides a method
`by which flexible or semi-rigid flame retardant non-ole
`finic polymeric materials, such as polyvinyl chloride,
`are able to be bonded to flexible metal tapes coated with
`a copolymer of ethylene and a monomer having a reac
`tive carboxyl group to provide tubing and shielded
`electrical cable that features enhanced flame retarding
`characteristics in combination with improved flexibility
`in conjunction with improved resistance to wrinkling of
`such materials upon the bending of products utilizing
`the combination.
`More particularly, it has been found that flexible or
`semi-rigid non-olefinic polymeric materials that hereto
`for have been unable to be satisfactorly bonded to metal
`tapes coated with a copolymer of ethylene and a mono
`mer having a reactive carboxyl group can be effectively
`bonded indirectly thereto by the use of an adhesive
`deposed between the coating and such materials that is
`adapted to bond them together. It has been further
`found that a polyamide based adhesive is particularly
`advantageous in bonding a broad range of flexible or
`semi-rigid non-olefinic polymeric materials to such
`coated tapes.
`As used herein, the term “non-olefinic polymeric
`materials' means olefinic polymers such as polyethyl
`ene and polypropylene in which a sufficient number of
`the available hydrogens have been replaced within the
`carbon chain and/or pendant thereto with chemical
`groups such as nitrogen or halogens such as chlorine or
`fluorine and the like to cause them to be classified as
`either non-olefinic or amorphic or elastomeric in nature
`rather than polyolefinic and includes elastomers such as
`chlorosulfonated polyethylene and elastomers such as
`polyurethane that contain closed carbon rings in their
`structure. As such, the term "non-olefinic polymeric
`materials” includes amorphic polymers such as polyvi
`nyl chloride in which certain of the pendant hydrogen
`atoms pendant to the olefins carbon chain backbone
`have been replaced with chlorine atoms as is also the
`case for polymers such as elastomeric chlorinated poly
`ethylene and also includes polymers such as nylon in
`which nitrogen atoms are used within the carbon chain
`backbone as well as elastomers such as chlorosulfonated
`polyethylene which feature substitutes of both chlorine
`and sulfur atoms for hydrogen atoms pendant to the
`olefinic carbon chain backbone.
`SUMMARY OF THE INVENTION
`It is accordingly an object of this invention to provide
`a method of bonding flexible or semi-rigid non-olefinic
`polymeric materials to a flexible metal tape coated with
`a copolymer of ethylene and a monomer with a reactive
`carboxyl group so as to provide a bonded construction
`that minimizes wrinkling of such materials upon the
`bending of the tape.
`It is another object of this invention to provide tubing
`and shielded electrical cable having improved flexibility
`and resistance to wrinkling on bending by incorporating
`a flexible metal tape that is coated on at least one of its
`sides with a copolymer of ethylene and a monomer with
`a reactive carboxyl group and to which coating is
`bonded a flexible or semi-rigid non-olefinic polymeric
`material.
`
`55
`
`60
`
`10
`
`15
`
`35
`
`INTRODUCTION
`This invention relates generally to tubing and electri
`cal cable shields made from flexible metallic tape and
`more particularly to tubing and electrical cable shields
`made from flexible metallic tape that has a coating
`bonded to at least one of its sides that is made from a
`copolymer of ethylene with a monomer having a reac
`tive carboxyl group such as acrylic acid or an acrylic
`acid ester and the utilization of an adhesive to bond the
`coated metal tape to flexible or semi-rigid non-olefinic
`polymeric materials.
`BACKGROUND OF THE INVENTION
`Flexible metal tape suitable for use in tubing and
`electrical cable shields and having at least one of its
`sides coated with a copolymer of ethylene and a mono
`mer having a reactive carboxyl group, such as disclosed
`20
`in U.S. Pat. No. 3,795,540, are well known in the art.
`Examples of an 8 and 12 mil aluminum tape coated on
`both sides with approximately 2 mils of a copolymer of
`ethylene and a monomer having a reactive carboxyl
`group suitable for use in the present invention are re
`25
`spectively sold under part numbers A282 and XO
`5554.07 under the Trademark "Zetabon' by Dow
`Chemical Company.
`Examples of shielded electrical cable or tubing utiliz
`ing metal tapes having the previously described adhe
`30
`sive on one or both of its sides are disclosed in U.S. Pat.
`Nos. 3,233,036; 3,272,912; 3,332,138 and 3,379,821. Such
`tapes proportedly provide mechanical protection and
`electrical shielding characteristics and such coating
`proportedly provides the metal with improved resis
`tance to corrosion and, where spiralled or longitudi
`nally folded into a tubular form and suitably bonded the
`overlap, are able to provide an effective gas and mois
`ture barrier. The presence of a reactive carboxyl group
`in the ethylene copolymer coating proportedly en
`40
`hances chemical bonding in a moist corrosive atmo
`sphere and enables polyolefinic materials, such as poly
`ethylene, to be effectively bonded to the tape.
`Although metallic tapes having at least one side
`coated with a copolymer of ethylene and a monomer
`45
`having a reactive carboxyl group may be used to advan
`tage in products such as disclosed in the previously
`described references, it has been found that flexible or
`semi-rigid non-olefinic amorphic polymers such as pol
`yvinyl chloride and polyurethane and substituted poly
`50
`olefins such as halogenated polyethylene of which an
`example is chlorinated polyethylene and chlorosulfo
`nated polyethylene such as sold under the trademark
`Hypalon being E. I. DuPont de Nemours do not bond
`well to the ethylene and monomer copolymer coating
`and as such have heretofor been unable to be used in
`conjunction with such tapes in an adhesively bonded
`relationship.
`There are many instances in both tubing and electri
`cal cable shielding where it is desirable to bond flexible
`or semi-rigid non-olefinic polymeric materials directly
`to the ethylene and monomer copolymer coating and
`thereby bond the metal tape to such polymers in order
`to utilize the greater flexibility and other desirable char
`acteristics generally associated with such polymers and
`65
`to minimize or eliminate wrinkling of such polymers
`upon the bending of tubing and electrical cable prod
`ucts in which they are used. Since flexible and semi
`
`

`

`4,327,248
`4.
`3
`layers of materials disposed outwardly of tape 4, is suit
`It is a further object of this invention to provide tub
`ing and shielded electrical cable that are imparted with
`able for the purpose intended.
`improved flexibility and flame retardency by incorpo
`Adhesive layer 8 is disposed between outer protec
`tive covering 9 and the outer surface of coating 5 and
`rating a flexible metal tape that is coated on at least one
`of its sides with a copolymer of ethylene and a mono
`bonds them together. Covering 9 is made from a flexible
`mer with a reactive carboxyl group and to which coat
`or semi-rigid non-olefinic polymeric material, such as
`polyvinyl chloride or amorphic chlorinated polyethyl
`ing is bonded a flexible or semi-rigid flame retardant
`non-olefinic polymeric material.
`ene, or an elastomeric material such as polyurethane,
`synthetic rubber, rubber and the like as previously de
`It is a feature of this invention to provide tubing or
`shielded electrical cable having improved flexibility and
`scribed.
`resistance to wrinkling or bending by incorporating a
`Layer 8 is made from an adhesive adapted to bond
`coating 5 and covering 9 together. Although layer 8
`flexible metal tape that is coated on at least one of its
`sides with a copolymer of ethylene and a monomer
`may be formed by spraying or coating a solvated adhe
`having a reactive carboxyl group and to which coating
`sive onto coating 5 that is adapted to bond it to covering
`15
`is bonded a flexible or semi-rigid non-olefinic polymeric
`9, it is preferred that layer 8 be extruded from a hot melt
`adhesive. A particular adhesive adapted to bond a
`material by means of a polyamide based adhesive inter
`broad range of flexible or semi-rigid non-olefinic poly
`posed therebetween.
`meric materials to a coating such as coating 5 made
`BRIEF DESCRIPTION OF DRAWINGS
`from a copolymer of ethylene and a monomer having a
`FIG. is a partially cut away perspective view of an
`reactive carboxyl group such as acrylic acid or an
`acrylic acid ester has been found to be a polyamide
`embodiment of tubing made in accordance with the
`based adhesive in which the polyamide is derived as a
`invention;
`FIG. 2 is a partially cut away side view of an embodi
`reaction product of diamines and dibase acids. It is fur
`ther preferred in the use of such polyamide adhesive
`ment of an electrical cable made in accordance with the
`25
`that an amount of piperazine not to exceed 15% by
`invention; and
`weight to the total weight of the polyamide be used in
`FIG. 3 is an end view of an embodiment of tubing
`the formation of the polyamide based adhesive in order
`made in accordance with the invention.
`to improve its resistance to hot water. An example of a
`suitable extrudable hot melt polyamide based adhesive
`is sold under the Tradename Terlan 1580 by Terrell
`Corporation. Although the thickness of layer 8 may
`range from about mill to about 10 mils, it is preferred
`that the thickness of layer 8 be from about 2 mils to
`about 5 mils and more preferably from about 2 mils to
`about 3 mils. Although such polyamide based adhesives
`may be applied by solvent spraying or coating, as previ
`ously described, it is preferred that the polyamide based
`be extruded as a hot melt.
`Thus a preferred embodiment of tubing made in ac
`cordance with the invention comprises an 8-12 mil
`flexible aluminum tape having a thin coating bonded to
`at least one of its sides that is made from a copolymer of
`ethylene and a monomer having a reactive carboxyl
`group such as acrylic acid or an acrylic acid ester,
`wherein the tape is folded longitudinally into a tubular
`shape having a lap seam with the copolymer ethylene
`coating on the outer surface of the metal tape also bond
`ing the edges together at the lap seam and the folded
`tape is enclosed by an extruded hot melt adhesive, such
`as a polyamide based hot melt adhesive, which bonds
`the outer coating to an outer protective covering made
`from a flexible non-olefinic polymeric material as herein
`defined that preferably has been compounded for flame
`retardency.
`FIG. 2 illustrates an embodiment of an electrical
`cable 14 made in accordance with the invention. Cable
`14 comprises a plurality of insulated electrical conduc
`tors 10 enclosed by previously described tape 4. Tape 4
`is folded longitudinally about conductors 10 and, in the
`view shown on FIG. 2, the previously described metal
`layer 6 and outer coating 5 are shown at the overlap
`ping edge of tape 4. Disposed about and bonded to
`coating 5 is adhesive layer 8 that, as previously de
`scribed, is preferably an extruded hot melt adhesive that
`preferably contains an amount of piperazine not exceed
`ing 15% by weight to the total weight of the polyamide.
`Adhesive layer 8 is enclosed by and bonded to previ
`
`DESCRIPTION OF PREFERRED EMBODIMENT
`30
`FIG. illustrates an embodiment of tube 13 made in
`accordance with the invention. Tube 13 has an inner
`liner in the form of Tape 4 that has been longitudinally
`folded into a tubular shape having an overlap seam 7.
`Tape 4 has an inner flexible metal layer 6 and an outer
`35
`adhesive coating 5. Coating 5 is made from a copolymer
`of ethylene and a monomer having a reactive carboxyl
`group such as acrylic acid or an acrylic acid ester. Al
`though in the embodiment shown in FIG. 1, tape 4 has
`coating 5 only on its outer surface, tape 4 may also have
`40
`coating 5 on the inner surface where such is desired to
`provide corrosion and moisture protection to the metal
`provided that such coating suitably resists the fluid
`intended to be conveyed through tube 3. Understand
`ably, tape 4 may also have a coating on its inner surface
`45
`made from a copolymer of ethylene and a monomer
`have a reactive carboxyl group or from another mate
`rial if such is desired.
`It is to be further understood that tape 4 may be in a
`spirally wrapped configuration with suitable overlap at
`its edges in lieu of a longitudinally folded configuration
`where such is desirable and suitable for the application
`intended.
`Although metal layer 6 may be made from any suit
`able flexible metal such as steel or an alloy of copper, it
`55
`is preferred that layer 6 be made from a flexible alumi
`num alloy. Although the thickness of layer 6 may range
`from about 3 mils to about 20 mils, it is preferred that
`the thickness of layer 6 range from about 5 mils to about
`15 mils and more preferably from about 8 mils to about
`12 mills.
`Coating 5 encloses and is bonded to the outer surface
`of layer 6 and also bonds the inner surface of layer 6 to
`the outer surface of layer 5 at lap seam 7. Although a lap
`seam 7 is preferred in the forming of a tubular shape, the
`edges of tape 4 may be abutted against each other if
`such is desired provided that the strength of bond be
`tween the edges, and as enhanced by any additional
`
`60
`
`65
`
`10
`
`20
`
`SO
`
`

`

`6
`TABLE I
`
`Nature
`Amorphic
`
`Non-olefinic
`Elastomeric
`
`Eastomeric
`
`Elastomeric
`
`Olefinic
`•
`
`Amorphic
`
`Elastomeric
`
`. Non-olefinic
`
`lb/in width
`3 mil
`Terlan
`1580 ad
`hesive
`between
`coating &
`subject
`material
`6.6
`
`Direct to
`ethylene
`copolymer
`coating
`0.0
`
`0.6
`0.4
`
`0.4
`
`0.0
`
`4.6
`
`0.4
`
`O.O
`
`O.O
`
`2.6
`13.6
`
`10.4
`
`16.0
`
`0.6
`
`17.2
`
`2.8
`
`0.4
`
`15
`
`2
`3
`
`... 4
`
`Sample Material
`10 -
`1
`Monomeric
`plasticized
`Polyvinyl
`chloride
`(compounded
`for fame .
`retardency)
`Nylon
`Chlorinated
`Polyethylene
`(Chlorosu-
`lfonated Poly
`ethylene)
`Thermo-
`plastic
`Polyurethane
`(polyether base)
`Polyethy-
`lene (Low
`Density)
`Polyvinyl
`chloride
`ethylene vinyl
`acetate graft
`copolymer
`8 . Thermo-
`plastic
`Polyester
`Fluorinated
`Hydrocarbon
`
`5
`
`6
`
`7
`
`9
`
`4,327,248
`5
`ously described protective covering 9 made from a
`flexible or semi-rigid non-olefinic polymeric material.
`Tape 4 provides both an electrical shield and mechan
`ical protection for cable 14 in that conductors 10 are
`enclosed by metal that can be suitably grounded so as to
`drain off spurious static electrical noise that might oth
`erwise affect the quality of the electrical signal being
`transmitted through conductors where such cable is
`being used for electrical signal transmission purposes.
`Although FIG. 2 shows tape 4 in adjacent relationship
`about conductors 10, such is for illustrative purposes
`only, and intermediate components such as fillers, flame
`barriers, fibrous or metallic reinforcements and the like
`may be deposed between tape. 4 and conductors 10.
`Likewise additional layers offibrous or polymeric mate
`rial may be disposed outwardly of cover 9 where such
`is desired.
`FIG. 3 illustrates an embodiment of a tube 15 made in
`accordance with the invention wherein tape 4 has both
`of its sides coated with an adhesive made from a copoly
`mer of ethylene and a monomer having a reactive car
`boxyl group. Shown in FIG. 3 is inner liner 11 made
`from an olefinic material such as polyethylene. Liner 11
`is enclosed by tape 4 that has a coating 5 on both its
`25
`inner and outer surfaces. Inner coating 5 is disposed
`between liner 11 and metal layer 6 of tape 4 and bonds
`them together. Adhesive layer 8 is disposed between
`outer coating 5 and covering 9 and is adapted to bond
`them together. Covering 9 is made from a flexible or
`30
`semi-rigid non-olefinic polymeric material. Tape 4 has
`abutting edges that meet at point 12 instead of the over
`lapping seam illustrated in FIGS. 1 and 2. Thus, advan
`tage may be taken by utilizing an inner liner 11 made
`from an olefinic material such as polyethylene for
`35
`chemical resistance in conjunction with providing me
`chanical protection by means of metal layer 6 and pro
`viding improved flexibility by bonding to outer coating
`5, a flexible cover 9 made from a non-olefinic polymeric
`material by means of an adhesive disposed therebe
`40
`tween that is adapted to bond cover 9 to coating 5.
`Although not illustrated in the Figures, it can be
`appreciated that variations of the invention include
`embodiments such as shown in FIG. 2 whereas a plural
`ity flexible polymeric and/or metal tubes, such as previ
`45
`ously described in reference to FIG. 1 are used in place
`of conductors 10 or and that a non-olefinic polymeric
`material may be used in the place of olefinic liner 11 of
`FIG. 3 with an additional layer 8 interposed between
`the outer surface of liner 11 and inner coating 5 and
`50
`bonding them together.
`Following Table I illustrates the relatively poor bond
`exhibited between flexible non-olefinic polymeric mate
`rials as the term is used herein and an 8 mil flexible
`aluminum tape coated with approximately 2 mils of a
`55
`copolymer of ethylene and acrylic acid as well as illus
`trating how well the ethylene copolymer adhesive
`bonds to a crystalline material such as polyethylene and
`the marked improvement in bonding achieved when an
`approximate 3 mil layer of adhesive adapted to bond
`60
`them together is interposed between the ethylene co
`polymer adhesive and the flexible non-olefinic materials
`used for the investigation. All samples were bonded at
`275 F. while applying a pressure of 10 P.S.I. The sam
`ples were cut into ' wide strips and bond level in
`65
`lb/inch of width was determined by pulling the coated
`tape in a direction of 180 from the subject materials at
`a rate of 12 inches per minute at room temperature.
`
`Sample 1 is a flexible flame retardant polyvinyl chlo
`ride compound sold under the number 202 FRCSA by
`the Panasote Company. Sample 2 is a flexible type 6
`nylon sold under the tradename Capron by Allied
`Chemical Company. Sample 3 is a flexible flame retar
`dant radiation crosslinkable compound of elastomeric
`chlorinated polyethylenes. Sample 4 is a flexible, flame
`retardant, radiation crosslinkable chlorosulfonated
`polyethylene compound. Sample 5 is a flexible polyester
`based polyurethane formerly sold under the tradename
`Roylar A 863 by the Uniroyal Company. Sample 6 is a
`low density polyethylene sold under the tradename
`Alathon 1250 BK 40 by the E. I. dePont de Nemours
`Company. Sample 7 is a flexible EVA-PVC graft co
`polymer compound sold under the number 1131 by the
`Pantasote Company. Sample 8 is a flexible thermoplas
`tic polyester sold under the tradename Hytrel 6345 by
`the E. I. duPont de Nemours Company. Sample 9 is a
`flexible polyvinylidene fluoride polymer sold under the
`tradename Kynar by the Pennwalt Corporation.
`The above data illustrates a surprising increase in
`bond level achieved between a non-olefinic material as
`the term is used herein and a coating made from a co
`polymer of ethylene and a monomer having a reactive
`carboxyl group such as acrylic acid or an acrylic acid
`ester by interposing therebetween a polyamide based
`adhesive such as Terlan 1580. It is also interesting to
`note that the addition of a polyamide based adhesive
`actually lessened the bond between the coating and an
`olefinic material such as the polyethylene used in Sam
`ple 6.
`In a preferred method of making tubing or shielded
`electrical cable in accordance with the invention a flexi
`
`

`

`5.
`
`O
`
`5
`
`25
`
`4,327,248
`7
`8
`(b) a flexible metal tape disposed in emcompassing
`ble metal tape of indeterminate length having a coating
`of a copolymer of an ethylene and a monomer having a
`relationship in the form of a shield about the elec
`reactive carboxyl group is folded longitudinally into a
`trical conductor;
`(c) a coating of a copolymer of ethylene and a mono
`tubular form by a suitable guide such that the coating is
`mer having a reactive carboxyl group disposed on
`on the outside and the edges of the tape overlap to form
`a lap seam having the coating interposed therebetween.
`at least the outer surface of the shield;
`(d) a covering disposed in emcompassing relationship
`The lap seam is then bonded by the use of an amount of
`about the coated shield, said covering made from a
`heat sufficient to soften the coating. A suitably heated
`flexible or semi-rigid non-olefinic polymeric mate
`hot melt adhesive that is adapted to bond the coating to
`rial; and
`a flexible or semi-rigid non-olefinic polymeric material,
`(e) an adhesive disposed intermediate the shield coat
`such as polyamide based adhesive, is then extruded
`ing and the covering and adapted to bond them
`about the folded tape which may, by its heat alone,
`together.
`provide sufficient heat to create the previously de
`2. The cable of claim 1 wherein the adhesive that is
`scribed bond at the lap seam. A flexible non-olefinic
`adapted to bond the coating to a flexible or semi-rigid
`polymeric covering is then extruded about the adhesive
`non-olefinic polymeric material is a polyamide based
`and is bonded to the ethylene copolymer coating by
`adhesive in which the polyamide is derived as the reac
`means of the adhesive. The covered tube or shielded
`tion product of diamines and dibasic acids.
`electrical cable is then cooled to room temperature by
`3. The cable of claim 2 wherein the polyamide based
`suitable means, such as water, after which the tubing or
`adhesive contained not more than about 15% by weight
`20
`shielded electrical cable is either subjected to some
`of piperazine to the total weight of polyamide in its
`further manufacturing step if such is required or cut into
`formation.
`determinate lengths for use in desired applications.
`4. The cable of claim 1 wherein the monomer is
`The flexible or semi-rigid non-olefinic polymeric
`acrylic acid or an acrylic acid ester.
`materials used in accordance with the invention include
`5. The cable of claim 1 wherein the adhesive is an
`both thermoplastic and cross-linkable versions of such
`extruded hot melt adhesive.
`materials. For example, covering 9 may be extruded
`6. The cable of claim 1 wherein the shield is in a
`from an amorphic thermoplastic polyvinyl chloride or
`longitudinally folded configuration.
`chlorosulfonated polyethylene elastomer that is com
`7. The cable of claim 1 wherein the shield is in a
`pounded to be cured either by chemical means or expo
`spiralled configuration.
`30
`sure to radiation such as in the form of high speed elec
`8. The cable of claim 6 wherein the longitudinally
`trons. Although it is preferred that the flexible or semi
`folded configuration includes a lap seam formed by
`rigid non-olefinic polymeric materials used in accor
`overlapping edges of the tape and the overlapping
`dance with the invention be extruded to provide the
`edges are bonded together by the coating.
`covering that is bonded to the coating of the copolymer
`9. The cable of claim 1 wherein the metal is an alumi
`35
`of ethylene and a monomer having a reactive carboxyl
`num alloy.
`group, such materials may be applied by other means
`10. The cable of claim 1 wherein the flexible or semi
`such as by coating or wrapping when such materials are
`rigid non-olefinic material is a material selected from
`in the form of a tape.
`the group consisting of polyamide, polyvinyl chloride,
`Although a monomeric plasticized polyvinyl chlo
`polyurethane, halogenated polyethylene, thermoplastic
`40
`ride may be used as a non-olefinic material in accor
`polyester, vinylidene fluoride and chlorosulfonated
`polyethlylene polymers.
`dance with the invention, best results in terms of resis
`tance to heat up to 200 F. have been realized where a
`11. The cable of claim 10 wherein the halogenated
`polymeric plasticizer is used in preference to a mono
`polyethylene is a chlorinated polyethylene.
`meric plasticizer.
`12. The cable of claim 10 wherein the halogenated
`45
`What is claimed is:
`polyethylene is a chlorinated fluorocarbon.
`1. A shielded electrical cable having improved flexi
`13. The cable of claim 1 wherein the non-olefinic
`bility and resistance to wrinkling on bending, said cable
`polymeric material is a flame retardant non-olefinic
`comprising:
`polymeric material.
`(a) at least one insulated electrical conductor;
`sk
`
`k
`
`&
`
`k
`
`sk
`
`50
`
`55
`
`60
`
`65
`
`