United States Patent (19)
`Keogh et al.
`
`USOO538059A
`Patent Number:
`Date of Patent:
`
`11
`45
`
`5,380,591
`Jan. 10, 1995
`
`54
`75
`
`73
`
`21)
`22
`51
`52
`
`(58)
`
`Assignee:
`
`TELEPHONE CABLES
`Inventors: Michael J. Keogh; Geoffrey D.
`Brown, both of Bridgewater, N.J.
`Union Carbide Chemicals & Plastics
`Technology Corporation, Danbury,
`Conn.
`Appl. No.: 998,439
`Filed:
`Dec. 30, 1992
`Int. Cl.......................... B32B 15/00; HO1B 7/00
`U.S. C. .................................... 428/379; 428/372;
`428/378; 174/23 C; 174/23R; 174/110 PM;
`174/110 SR; 174/113 R
`Field of Search ............................... 428/378,379;
`174/120 SR, 110 SR, 113 R, 16, 110 RM, 23,
`23R; 524/99, 103; 546/200,208,242, 249,245,
`27
`
`56
`
`References Cited
`U.S. PATENT DOCUMENTS
`3,660,438 5/1972 Dexter .............................. 260/404.5
`3,773,722 11/1973 Dexter .......................... 260/45.75 C
`
`
`
`3,790,694 2/1974
`4,065,635 12/1977
`... 525/167
`4,233,412 11/1980
`... 528/279
`4,507,463 3/1985
`4,535,145 8/1985 Troxler et al. ...................... 528/289
`FOREIGN PATENT DOCUMENTS
`988642 5/1976 Canada .
`434080 6/1991 European Pat. Off. .
`Primary Examiner-Patrick J. Ryan
`Assistant Examiner-J. M. Gray
`Attorney, Agent, or Firm-Saul R. Bresch
`(57)
`ABSTRACT
`An article of manufacture comprising (i) a plurality of
`electrical conductors, each surrounded by one or more
`layers of a composition comprising (a) one or more
`polyolefins and, blended therewith, (b) a mixture con
`taining one or more alkylhydroxyphenylalkanoyl hy
`drazines and one or more functionalized hindered
`amines; and (ii) hydrocarbon cable filler grease within
`the interstices between said surrounded conductors.
`
`14 Claims, No Drawings
`
`

`

`1.
`
`TELEPHONE CABLES
`
`5
`
`TECHNICAL FIELD
`This invention relates to wire and cable and the insu
`lation and jacketing therefor and, more particularly, to
`telephone cable.
`BACKGROUND INFORMATION
`A typical telephone cable is constructed of twisted
`pairs of metal conductors for signal transmission. Each
`conductor is insulated with a polymeric material. The
`desired number of transmission pairs is assembled into a
`circular cable core, which is protected by a cable sheath
`incorporating metal foil and/or armor in combination
`with a polymeric jacketing material. The sheathing
`protects the transmission core against mechanical and,
`to some extent, environmental damage.
`Of particular interest are the grease-filled telephone
`20
`cables. These cables were developed in order to mini
`mize the risk of water penetration, which can severely
`upset electrical signal transmission quality. A water
`tight cable is provided by filling the air spaces in the
`cable interstices with a hydrocarbon cable filler grease.
`While the cable filler grease extracts a portion of the
`25
`antioxidants from the insulation, the watertight cable
`will not exhibit premature oxidative failure as long as
`the cable maintains its integrity.
`In the cable transmission network, however, junc
`tions of two or more watertight cables are required and
`30
`this joining is often accomplished in an outdoor enclo
`sure known as a pedestal (an interconnection box). In
`side the pedestal, the cable sheathing is removed, the
`cable filler grease is wiped off, and the transmission
`wires are interconnected. The pedestal with its now
`35
`exposed insulated wires is usually subjected to a severe
`environment, a combination of high temperature, air,
`and moisture. This environment together with the de
`pletion by extraction of those antioxidants presently
`used in grease-filled cable can cause the insulation in the
`pedestal to exhibit premature oxidative failure. In its
`final stage, this failure is reflected in oxidatively embrit
`tled insulation prone to cracking and flaking together
`with a loss of electrical transmission performance.
`To counter the depletion of antioxidants, it has been
`45
`proposed to add high levels of antioxidants to the poly
`meric insulation. However, this not only alters the per
`formance characteristics of the insulation, but is eco
`nomically unsound in view of the high cost of antioxi
`dants. There is a need, then, for antioxidants which will
`50
`resist cable filler grease extraction to the extent neces
`sary to prevent premature oxidative failure and ensure
`the 30 to 40 year service life desired by industry.
`DISCLOSURE OF THE INVENTION
`55
`An object of this invention, therefore, is to provide a
`grease-filled cable construction containing antioxidants,
`which will resist extraction and be maintained at a satis
`factory stabilizing level. Other objects and advantages
`will become apparent hereinafter.
`According to the invention, an article of manufacture
`has been discovered which meets the above object.
`The article of manufacture comprises, as a first con
`ponent, a plurality of electrical conductore, each sur
`rounded by one or more layers of a composition con
`65
`prising (a) one or more polyolefins and, blended there
`with, (b) a mixture containing one or more alkylhydrox
`yphenylalkanoyl hydrazines and one or more function
`
`10
`
`15
`
`5,380,591
`2
`alized hindered amines; and, as a second component,
`hydrocarbon cable filler grease within the interstices
`between said surrounded conductors.
`In one other embodiment, the article of manufacture
`comprises first and second components; however, the
`mixture of the first component contains absorbed hy
`drocarbon cable filler grease or one or more of the
`hydrocarbon constituents thereof and, in another em
`bodiment, the article of manufacture is comprised only
`of the first component wherein the mixture contains
`hydrocarbon cable filler grease or one or more of the
`hydrocarbon constituents thereof.
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`The polyolefins used in this invention are generally
`thermoplastic resins, which are crosslinkable. They can
`be homopolymers or copolymers produced from two or
`more comonomers, or a blend of two or more of these
`polymers, conventionally used in film, sheet, and tub
`ing, and as jacketing and/or insulating materials in wire
`and cable applications. The monomers useful in the
`production of these homopolymers and copolymers can
`have 2 to 20 carbon atoms, and preferably have 2 to 12
`carbon atoms. Examples of these monomers are alpha
`olefins such as ethylene, propylene, 1-butene, 1-hexene,
`4-methyl-1-pentene, and 1-octene; unsaturated esters
`such as vinyl acetate, ethyl acrylate, methyl acrylate,
`methyl methacrylate, t-butyl acrylate, n-butyl acrylate,
`n-butyl methacrylate, 2-ethylhexyl acrylate, and other
`alkyl acrylates; diolefins such as 1,4-pentadiene, 1,3hex
`adiene, 1,5-hexadiene, 1,4-octadiene, and ethylidene
`norbornene, commonly the third monomer in a terpoly
`mer; other monomers such as styrerie, p-methylstyrene,
`alpha-methyl styrene, p-chloro styrene, vinyl naphtha
`lene, and similar aryl olefins; nitriles such as acryloni
`trile, methacrylonitoile, and alpha-chloroacry-lonitrile;
`vinyl methyl ketone, vinyl methyl ether, vinylidene
`chloride, maleic anhydride, vinyl chloride, vinylidene
`chloride, vinyl alcohol, tetrafluoroethylene, and chlo
`rotdifluoroethylene; and acrylic acid, methacrylic acid,
`and other similar unsaturated acids.
`The homopolymers and copolymers referred to can
`be non-halogenated, or halogenated in a conventional
`manner, generally with chlorine or bromine. Examples
`of halogenated polymers are polyvinyl chloride, polyvi
`nylidene chloride, and polytetrafluoroethylene. The
`homopolymers and copolymers of ethylene and propy
`lene are preferred, both in the non-halogenated and
`halogenated form. Included in this preferred group are
`terpolymers such as ethylene/propylene/diene mono
`mer rubbers.
`Other.examples of ethylene polymers are as follows:
`a high pressure homopolymer of ethylene; a copolymer
`of ethylene and one or more alpha-olefins having 3 to 12
`carbon atoms; a homopolymer or copolymer of ethyl
`ene having a hydrolyzable silane grafted to their back
`bones; a copolymer of ethylene and an alkenyl triakloxy
`silane such as trimethoxy vinylsilane; or a copolymer of
`an alpha-olefin having 2 to 12 carbon atoms and an
`unsaturated ester having 4 to 20 carbon atoms, e.g., an
`ethylene/ethyl acrylate or vinyl acetate copolymer; an
`ethylene/ethyl acrylate or vinyl acetate/hydrolyzable
`silane terpolymer; and ethylene/ethyl acrylate or vinyl
`acetate copolymers having a hydrolyzable silane
`grafted to their backbones.
`
`

`

`5,380,591
`3
`With respect to polypropylene: homopolymers and
`copolymers of propylene and one or more other alpha
`olefins wherein the portion of the copolymer based on
`propylene is at least about 60 percent by weight based 5
`on the weight of the copolymer can be used to provide
`the polyolefin of the invention. Polypropylene can be
`prepared by conventional processes such as the process
`described in U.S. Pat. No. 4,414,132. Preferred polypro
`pylene alpha-olefin comonomers are those having 2 or 4
`to 12 carbon atoms.
`The homopolymer or copolymers can be crosslinked
`or cured with an organic peroxide, or to make them
`hydrolyzable, they can be grafted with an alkenyl trialk
`oxysilane in the presence of an organic peroxide which
`acts as a free radical generator or catalyst. Useful alke
`nyl trialkoxy silanes include the vinyl trialkoxy silanes
`such as vinyl trimethoxy silane, vinyl triethoxy silane,
`and vinyl triisopropoxy silane. The alkenyl and alkoxy
`radicals can have 1 to 30 carbon atoms and preferably
`have 1 to 12 carbon atoms. The hydrolyzable polymers
`can be moisture cured in the presence of a silanol con
`densation catalyst such as dibutyl tin dilaurate, dioctyl
`tin maleate, stannous acetate, stannous octoate, lead
`naphthenate, zinc octoate, iron 2-ethyl hexoate, and
`other metal carboxylates.
`The homopolymers or copolymers of ethylene
`wherein ethylene is the primary comonomer and the
`homopolymers and copolymers of propylene wherein
`propylene is the primary comonomer may be referred
`to herein as polyethylene and polypropylene respec
`tively.
`For each 100 parts by weight of polyolefin, the other
`components of the insulation mixture can be present in
`about the following proportions:
`
`10
`
`5
`
`20
`
`30
`
`35
`
`HO
`
`O
`H.
`H.
`(CH2)-C-N-N-R3
`
`R2
`
`wherein n is 0 or an integer from 1 to 5;
`R1 is an alkyl having 1 to 6 carbon atoms;
`R2 is hydrogen or R1; and
`R is hydrogen, an alkanoyl having 2 to 18 carbon
`atoms, or the following structural formula:
`
`R1
`
`HO
`
`(CH2)-C-
`
`R2
`
`The hindered amines useful in the invention are those
`which have limited solubility in the hydrocarbon cable
`filler grease described below. An analogy can be drawn
`between solubility in the filler grease and solubility in
`n-hexane at 20° C. Thus, preferred hindered amines are
`those having a solubility in n-hexane at 20 C. of less
`than about one percent by weight based on the weight
`of the n-hexane.
`Particularly useful hindered amines have the follow
`ing general structural formula:
`
`CH3
`
`CH3
`
`O
`O
`N-(R)-o-c-(R')-c--OR5
`
`H-HO
`
`Component
`(i) hydrazine
`(ii) hindered
`anine
`(iii) grease
`
`Parts by Weight
`Broad
`Preferred
`Range
`Range
`at least 0.1
`0.3 to 2.0
`at least 0.0
`0.05 to 1.0
`
`3 to 30
`
`5 to 25
`
`45
`
`50
`
`Insofar as the hydrazine and the hindered amine are
`concerned, there is no upper limit except the bounds of
`practicality, which are dictated by economics, i.e., the
`cost of the antioxidants in this vein, most preferred
`upper limits are about 1.0 and about 0.5 part by weight,
`respectively.
`The weight ratio of hydrazine to hindered amine can
`be in the range of about 1:1 to about 20:1, and is prefera
`bly in the range of about 2:1 to about 15:1. A most
`preferred ratio is about 3:1 to about 10:1. It should be
`noted that the hindered amine is effective at very low
`use levels relative to the hydrazine.
`Alkylhydroxyphenylalkanoyl hydrazines are de
`65
`scribed in U.S. Pat. Nos. 3,660,438 and 3,773,722.
`A preferred general structural formula for hydrazines
`useful in the invention is as follows:
`
`55
`
`60
`
`CH3
`CH3
`
`wherein each R is independently a divalent hydro
`carbyl having 1 to 6 carbon atoms;
`R is hydrogen, alkyl having 1 to 6 carbon atoms, or
`aryl; and n is 2 to 50.
`The aryl group can be, for example, an unsubstituted
`benzene ring or a benzene ring substituted with an alkyl
`having 1 to 6 carbon atoms.
`A preferred hindered amine has the following for
`mula:
`
`CH3
`
`CH3
`
`HO
`
`N-CH2CH2-O-C-CH2CH2-C OCH3
`
`CH3
`CH3
`
`8-9
`
`wherein 8-9 means about 8 or 9.
`A distinguishing characteristic of this particular hin
`dered amine is that it has a number average molecular
`weight (Mn) greater than about 2000.
`Another preferred hindered amine has the following
`general formula:
`
`

`

`5,380,591
`
`H
`
`OH
`
`O
`
`HO
`
`H
`
`H
`
`O
`
`20
`
`15
`
`wherein each R is independently a divalent hydro
`carbyl having 1 to 6 carbon atoms;
`each R7 is independently a direct single bond or R;
`each R8 is independently an alkyl having 1 to 6 car
`bon atoms; and
`each R9 is independently hydrogen or R8.
`A hindered amine falling within the above formula is
`2,5bis 2-( 3-( 3,5-di-tert-butyl-4-hydroxy-phenyl)pro
`pionylamide)ethyl aminebenzoquinone.
`Additional hindered amines can be found in U.S. Pat.
`Nos. 4,233,412; 4,507,463; and 4,535,145.
`Hydrocarbon cable filler grease is a mixture of hydro
`carbon compounds, which is semisolid at use tempera
`25
`tures. It is known industrially as "cable filling com
`pound'. A typical requirement of cable filling com
`pounds is that the grease has minimal leakage from the
`cut end of a cable at a 60' C. or higher temperature
`rating. Another typical requirement is that the grease
`30
`resist water leakage through a short length of cut cable
`when water pressure is applied at one end. Among
`other typical requirements are cost competitiveness;
`minimal detrimental effect on signal transmission; mini
`mal detrimental effect on the physical characteristics of
`35
`the polymeric insulation and cable sheathing materials;
`thermal and oxidative stability; and cable fabrication
`processability.
`Cable fabrication can be accomplished by heating the
`cable filling compound to a temperature of approxi
`40
`mately 100° C. This liquefies the filling compound so
`that it can be pumped into the multiconductor cable
`core to fully impregnate the interstices and eliminate all
`air space. Alternatively, thixotropic cable filling com
`pounds using shear induced flow can be processed at
`45
`reduced temperatures in the same manner. A cross sec
`tion of a typical finished grease-filled cable transmission
`core is made up of about 52 percent insulated wire and
`about 48 percent interstices in terms of the areas of the
`total cross section. Since the interstices are completely
`50
`filled with cable filling compound, a filled cable core
`typically contains about 48 percent by volume of cable
`filling compound.
`The cable filling compound or one or more of its
`hydrocarbon constituents enter the insulation through
`55
`absorption from the interstices. Generally, the insula
`tion absorbs about 3 to about 30 parts by weight of cable
`filling compound or one or more of its hydrocarbon
`constituents, in toto, based on 100 parts by weight of
`polyolefin. A typical absorption is in the range of a total
`60
`of about 5 to about 25 parts by weight per 100 parts by
`weight of polyolefin.
`It will be appreciated by those skilled in the art that
`the combination of resin, cable filling compound con
`stituents, and antioxidants in the insulation is more diffi
`65
`cult to stabilize than, an insulating layer containing only
`resin and antioxidant, and no cable filling compound
`constituent.
`
`Examples of hydrocarbon cable filler grease (cable
`filling compound) are petrolatum; petrolatum/polyole
`fin wax mixtures; oil modified thermoplastic rubber
`(ETPR or extended thermoplastic rubber); paraffin oil;
`naphthenic oil; mineral oil; the aforementioned oils
`thickened with a residual oil, petrolatum, or wax; poly
`ethylene wax; mineral oil/rubber block copolymer mix
`ture; lubricating grease; and various mixtures thereof,
`all of which meet industrial requirements similar to
`those typified above.
`Generally, cable filling compounds extract insulation
`antioxidants and, as noted above, are absorbed into the
`polymeric insulation. Since each cable filling compound
`contains several hydrocarbons, both the absorption and
`the extraction behavior are preferential toward the
`lower molecular weight hydrocarbon wax and oil con
`stituents. It is found that the insulation composition
`with its antioxidant not only has to resist extraction, but
`has to provide sufficient stabilization (i) to mediate
`against the copper conductor, which is a potential cata
`lyst for insulation oxidative degradation; (ii) to counter
`the effect of residuals of chemical blowing agents pres
`ent in cellular and cellular/solid (foam/skin) polymeric
`foamed insulation; and (iii) to counter the effect of ab
`sorbed constituents from the cable filling compound.
`The polyolefin can be one polyolefin or a blend of
`polyolefins. The hydrazine and the functionalized hin
`dered amine are blended with the polyolefin. The com
`position containing the foregoing can be used in combi
`nation with disulfides, phosphites or other nonamine
`antioxidants in molar ratios of about 1:1 to about 1:2 for
`additional oxidative and thermal stability, but, of
`course, it must be determined to what extent these latter
`compounds are extracted by the grease since this could
`affect the efficacy of the combination.
`The following conventional additives can be added in
`conventional amounts if desired: ultraviolet absorbers,
`antistatic agents, pigments, dyes, fillers, slip agents, fire
`retardants, stabilizers. crosslinking agents, halogen
`scavengers, smoke inhibitors, crosslinking boosters,
`processing aids, e.g., metal carboxylates, lubricants,
`plasticizers, viscosity control agents, and blowing
`agents such as azodicarbonamide. The fillers can in
`clude, among others, magnesium hydroxide and alu
`mina trihydrate. As noted, other antioxidants and/or
`metal deactivators can also be used, but for these or any
`of the other additives, resistance to grease extraction
`must be considered.
`Additional information concerning grease-filled cable
`can be found in Eoll, The Aging of Filled Cable with
`Cellular Insulation, International Wire & Cable Sympo
`sium Proceeding 1978, pages 156 to 170, and Mitchellet
`al, Development, Characterization, and Performance of an
`improved Cable Filling Compound, International Wire &
`Cable Symposium Proceeding 1980, pages 15 to 25. The
`latter publication shows a typical cable construction on
`
`

`

`10
`
`15
`
`O
`
`OCH3
`
`20
`
`8-9
`
`CH
`3 CH3
`
`CH3
`CH3
`
`wherein Mn2000
`Antioxidant C is tetrakis methylene (3,5-di-tert
`butyl-4-hydroxyhydrocinnamate)methane.
`Antioxidant D is 2,5-bis(2-(3-(3,5-di-tert-butyl-4-
`hydroxy-phenyl)propionylamine)etyl aminebenzoqui
`
`25
`
`5,380,591
`8
`7
`cable filler grease used in these examples. It is a typical
`page 16 and gives additional examples of cable filling
`compounds.
`cable filling compound.
`The patents and other publications mentioned in this
`Each ten mill test plaque is then cut to provide about
`twenty approximately one-half inch square test speci
`specification are incorporated by reference herein.
`mens. Before testing, each vial is reheated to about 70
`The invention is illustrated by the following exam
`ples.
`C. to allow for the easy insertion of the test specimens.
`The specimens are inserted into the vial one at a time
`EXAMPLES 1 to 8
`together with careful wetting of all surfaces with the
`Various materials used in the examples are as follows:
`Polyethylene I is a copolymer of ethylene and 1-hex
`cable filler grease. After all of the specimens have been
`inserted, the vials are loosely capped and placed in a 70'
`ene. The density is 0,946 gram per cubic centimeter and
`C. circulating air oven. Specimens are removed after
`the melt index is 0.80 to 0.95 gram per 10 minutes.
`Antioxidant A is 1,2-bis(3,5-di-tert-butyl-4-hydrox
`1,2,4,6, and 8 weeks, the surfaces are wiped dry with
`yhydrocinnamoyl)hydrazine.
`tissue, and the specimens are tested for OIT.
`OIT testing is accomplished in a differential scanning
`Antioxidant B has the following structural formula:
`calorimeter with an OIT test cell. The test conditions
`are: uncrimped aluminum pan; no screen; heat up to
`200° C. under nitrogen, followed by a switch to a 50
`milliliter flow of oxygen. Oxidation induction time
`(OIT) is the time interval between the start of oxygen
`flow and the exothermic decomposition of the test spec
`imen. OIT is reported in minutes; the greater the num
`ber of minutes, the better the OIT. OIT is used as a
`measure of the oxidative stability of a sample as it pro
`ceeds through the cable filler grease exposure and the
`oxidative aging program. Relative performance in the
`grease filled cable applications can be predicted by
`comparing initial sample OIT to OIT values after 70° C.
`cable filler grease exposure and 90 C. oxidative aging.
`Variables and results are set forth in Table I.
`TABLE I
`3
`4.
`
`Example
`Formulation
`(parts by wt):
`Polyethylene I
`Antioxidant A
`Antioxidant B
`Antioxidant C
`OIT (minutes):
`Initial
`1 Week
`2 Weeks
`4. Weeks
`6 Weeks
`8 Weeks
`
`2
`
`5
`
`6
`
`7
`
`8
`
`99.40
`99.40 99.40
`0.50
`- 0.60
`0.60 - 0.10
`
`99.40
`0.40
`0.20
`
`99.40
`0.30
`O.30
`
`-
`
`over-
`
`99.40 99.40
`0.20
`0.10
`0.40
`0.50
`
`WD
`
`w
`
`99.55
`0.15
`0.15
`
`0.15
`
`203
`57
`53
`145
`144,
`139
`
`4
`3
`3
`3
`2.
`
`236
`260
`255
`2S2
`230
`234
`
`235
`224,
`236
`236
`202
`179
`
`185
`188
`170
`156
`155
`142
`
`135
`88
`67
`49
`22
`22
`
`60
`29
`12
`7
`7
`6
`
`189
`38
`31
`36
`2
`10
`
`Ole.
`10 mil polyethylene plaques are prepared for oxida
`tion induction time (OIT) testing. The plaques are pre
`pared from a mixture of polyethylene I and the antioxi
`dants mentioned above. The parts by weight of each are
`set forth in Tables I and II.
`A laboratory procedure simulating the grease filled
`cable application is used to demonstrate performance.
`Resin samples incorporating specified antioxidants are
`prepared. The samples are first pelletized and then
`formed into approximately 10 mil (0.010 inch) thick test
`plaques using ASTM D-1928 methods as a guideline.
`There is a final melt mixing on a two roll mill or labora
`tory BrabenderTM type mixer followed by preparation
`of the test plaques using a compressor molding press at
`150 C. Initial oxygen induction time is measured on
`these test plaques.
`A supply of hydrocarbon cable filler grease is heated
`to about 80 C. and well mixed to insure uniformity. A
`supply of 30 millimeter dram vials are then each filled to
`approximately 25 millimeters with the cable filler
`grease. These vials are then cooled to room temperature
`for subsequent use. An oil extended thermoplastic rub
`ber (ETPR) type cable filler grease is the hydrocarbon
`
`50
`
`55
`
`65
`
`In examples 2, 6, 7, and 8 after one week, the speci
`mens lose respectively 23, 35, 52, and 80 percent of the
`antioxidant effectiveness through grease extraction.
`Losses in examples 3, 4, and 5 are less than 5 percent by
`weight.
`In examples 2 to 7, the total of antioxidants is normal
`ized to 0.1 pad by weight in order to compare the rela
`tive effectiveness of the antioxidants. The results are as
`follows:
`
`Example
`2
`3
`4.
`5
`6
`7
`
`Normalized Initial
`OIT (minutes)
`34
`47.2
`58.8
`61.7
`67.5
`60.0
`
`It is noted that in examples 6 and 7, the synergetic
`effect is high, but the resistance to grease extraction is
`low.
`
`

`

`9
`EXAMPLES 9 to 13
`Example 1 is repeated except that Antioxidant D is
`substituted for Antioxidant B, and, after 4 weeks, the
`remaining specimens are removed, wiped dry, and
`placed in a static air chamber at 90° C. At 8, 12, and 16
`weeks, specimens are removed and tested for OIT.
`Variables and results are set forth in Table II.
`TABLE II
`O
`11
`
`Example
`
`9.
`
`O
`
`12
`
`13
`
`Formulation
`(part by weight) -
`Polyethylene I
`Antioxidant A
`Antioxidant B
`Antioxidant D
`OIT (minutes)
`Initial
`1 week
`2 weeks
`4 weeks
`8 weeks
`2 weeks
`16 weeks
`
`99.70
`0.30
`
`99.80
`
`99.70
`M
`
`99.40
`0.30
`
`am
`
`0.20
`
`0.30
`
`0.30
`
`103
`67
`74
`59
`58
`35
`36
`
`12
`15
`16
`18
`
`DOW
`
`18
`22
`24
`27
`D
`--
`
`285
`26
`308
`290
`264
`247
`228
`
`99.40
`0.40
`0.10
`0.10
`
`257
`284
`279
`278
`O
`
`15
`
`20
`
`25
`
`We claim:
`1. An article of manufacture comprising (i) a plurality
`30
`of electrical conductors having interstices therebe
`tween, each electrical conductor being surrounded by
`one or more layers of a composition consisting essen
`tially of (a) one or more polyolefins selected from the
`group consisting of polyethylene, polypropylene, and
`35
`mixtures thereof and, blended therewith, (b)a mixture
`containing one or more alkylhydroxyphenylalkanoyl
`hydrazines and one or more functionalized hindered
`amines; and (ii) hydrocarbon cable filler grease within
`40
`the interstices wherein the hydrazine has the following
`structural formula:
`
`5,380,591
`
`10
`
`CH3
`
`CH3
`
`CH3
`
`CH3
`
`wherein each R is independently a divalent hydro
`carbyl having 1 to 6 carbon atoms;
`R is hydrogen, alkyl having 1 to 6 carbon atoms, or
`aryl; and n is 2 to 50.
`2. The article of manufacture defined in claim 1
`wherein the solubility of the hindered amine in n-hexane
`at 20° C. is less than about one percent by weight based
`on the weight of the n-hexane.
`3. The article of manufacture defined in claim 1
`wherein, for each 100 parts by weight of polyolefin, the
`hydrazine(s) are present in an amount of at least 0.1 part
`by weight and the hindered amine(s) are present in an
`amount of at least 0.01 part by weight.
`4. The article of manufacture defined in claim 1
`wherein the weight ratio of hydrazine to hindered
`amine is in the range of about 1:1 to about 20:1.
`5. The article of manufacture defined in claim 1
`wherein the hydrazine is 1,2-bis(3,5-di-tert-butyl-4-
`hydroxyhydrocinnamoyl) hydrazine.
`6. The article of manufacture defined in claim 5
`wherein the hindered amine is a mixture of (a) a hin
`dered amine having the following structural formula:
`
`CH3
`
`CH3
`
`H-HO
`
`N-CH2CH2-O-C-CH2CH2-C OCH3
`
`CH CH3
`3
`
`8-9
`
`R1
`
`HO
`
`R2
`
`O
`H.
`H.
`(CH2)-C-N-N-R
`
`wherein the number average molecular weight is
`greater than about 2000 and (b) 2,5-bis(2-(3-(3,5-di-tert
`butyl-4-hydroxyphenyl)propionylamide)ethyl amine
`benzoquinone.
`7. The article of manufacture defined in claim 1
`wherein the hindered amine has the following structural
`formula:
`
`45
`
`50
`
`wherein n is 0 or an integer from 1 to 5;
`R is an alkyl having 1 to 6 carbon atoms;
`R2 is hydrogen or R; and
`55
`R3 is hydrogen, an alkanoyl having 2 to 18 carbon
`atoms or the following structural formula:
`
`CH3
`
`CH3
`
`H-HO
`
`N-CH2CH2-O-C-CH2CH2-C OCH3
`
`CH3
`
`CH3
`
`8-9
`
`R
`
`HO
`
`(CH2)-C-
`
`R2
`
`and wherein the hindered amine has the following
`structural formula:
`
`wherein the number average molecular weight is
`greater than about 2000.
`8. The article of manufacture defined in claim 4
`wherein the hydrazine is 1,2-bis(3,5-di-tert-butyl-4-
`hydroxy-hydrocinnamoyl)hydrazine.
`9. The article of manufacture defined in claim 1
`wherein the hindered amine has the following structural
`formula:
`
`65
`
`

`

`11
`
`5,380,591
`
`12
`
`H
`
`H
`
`O
`
`OH
`
`HO
`
`H
`
`H
`
`O
`
`15
`
`wherein each R6 is independently a divalent hydro
`carbyl having 1 to 6 carbon atoms;
`each R7 is independently a direct single bond or R;
`each R8 is independently an alkyl having 1 to 6 car
`bon atoms; and
`each R9 is independently hydrogen or R8.
`10. The article of manufacture defined in claim 9
`wherein the hindered amine is 2,5-bis(2-(3-(3,5-di-tert
`butyl-4-hydroxy-phenyl)-propionylamide)ethyl amine
`benzoquinone.
`11. The article of manufacture defined in claim 10
`wherein the hydrazine is 1,2-bis(3,5-di-tert-butyl-4-
`hydroxy-hydrocinnamoyl)hydrazine.
`12. The article of manufacture defined in claim 1
`wherein the hydrocarbon cable filler grease or one or
`more of the hydrocarbon constituents thereof is present
`in the composition of component (i).
`13. The article of manufacture defined in claim 12
`30
`wherein the amount of hydrocarbon cable filler grease
`or one or more of the hydrocarbon constituents thereof,
`intoto, present in the composition of component (i) is in
`the range of about 3 to about 30 parts by weight based
`on 100 parts by weight of polyolefin.
`14. An article of manufacture comprising (i) a plural
`ity of electrical conductors having interstices therebe
`
`25
`
`35
`
`tween, each electrical conductor being surrounded by
`one or more layers of a composition consisting essen
`tially of (a) polyethylene, polypropylene, or mixtures
`thereof and, blended therewith, (b) a fixture comprising
`(A) 1,2-bis( 3,5-di-tert-butyl-4-hydroxy-hydrocinnam
`oyl hydrazine and (B) a hindered amine having the
`following structural formula:
`
`CH
`3 CH3
`
`H-HO
`
`N-CHCH-O-C-CH2CH2-C OCH3
`
`CH CH
`3
`
`8-9
`
`wherein the number average molecular weight is
`greater than 200 and/or 2,5-bis(2-(3-(3,5-di-tert-butyl
`4-hydroxyphenyl)propionylamide)ethyl
`amine-ben
`zoquinone and (ii) hydrocarbon cable filler grease
`within the interstices wherein the weight ratio of com
`ponent (A) to component (B) is in the range of about 3:1
`to about 10:1.
`
`:
`
`k
`
`k
`
`45
`
`50
`
`55
`
`65
`
`

`

`UNITED STATES PATENT AND TRADEMARK OFFICE
`CERTIFICATE OF CORRECTION
`5,380,591
`PATENT NO. :
`January 10, 1995
`DATED
`:
`Keogh et all
`INVENTOR(S) :
`It is certified that error appears in the above-identified patent and that said Letters Patent is hereby
`corrected as shown below:
`Columns 9 and ll, lines 29 and 36, respectively, change "An article of
`manufacture' to --A cable--.
`
`Column 10, lines 15, 19, 24, 27, 31, 48, 63, and 66, and Column 11, lines
`19s 23, 26 and 30, change "The article of manufacture" to --The cable--.
`Column 10, lines l7, 45, and 62, delete "about".
`Column 10 line 63, change "4" to -7--.
`Column 12 line 16, change "fixture" to --mixture--.
`Column 12, 1ine 31, change "200" to -2000--.
`
`Attest
`
`Signed and Sealed this
`Ninth Day of May, 1995
`(a (eam
`
`BRUCE LEHMAN
`
`Attesting Officer
`
`Commissioner of Patents and Trademarks
`
`
`
`