BE687742A - - Google Patents

Description

  

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    Proceeds to make polyolefins used as dielectrics stable to voltage effects.



   The invention relates to an electrically insulating material of high dielectric strength for use at high voltages of the order of kilovolts and more particularly to a solid polyclefin, for example polyethylene, which has been found to be a dielectric of better quality. stability to voltage effects in power transmission cables.



   In the recent past, synthetic high polymers have found increasing application as insulating materials in various fields of electricity. In particular, solid polymers of olefins, especially polyethylenes and polypropylene, for example, are generally suitable as electrical insulators for cables and electrical wires due to their good mechanical properties and ease.

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 of implementation combining with excellent electrical properties. However, for high voltages, the use of these substances has only been possible within narrow limits because their breakdown voltage has not even been approached in practice.



   Thus, the solid polyolefins used in dielectric retorts for the insulation of cables or similar products and which do not contain one or the other additive having the property of making it stable to the effects of voltage, hereinafter called "gas stabilizer additive. voltage "offer the annoying property, when an alternating potential is applied, that when the applied voltage increases rapidly to the breakdown voltage; this is appreciably higher than when the applied voltage is raised slowly and maintained for a certain time at. this value.

   For example, a slow rise in potential for polyethylene as an insulator is 65-85% of the breakdown voltage valid for a rapid rise. In theory, the relative weakness of industrially produced polyolefin insulators arises from defects and small dimension Iras air bubbles which form during manufacture and which are impossible to avoid in industrial manufacture on, For example,

   small particles of foreign matter are always present in the hydrocarbon matrix * Careful examination of the numerous defects on samples has now shown that these small defects often initiate in the insulation the birth of a defect, the growth of which produces a rupture due to to avalanches of electrons coming from the current flowing in the cable, which produces ionization, then a rupture at the location of the fault.

   A method of reducing this tendency of foreign matter to initiate faults which would consist of delaying or preventing this avalanche of electrons would obviously have the following effects.

 <Desc / Clms Page number 3>

 
 EMI3.1
 result one at the #:> Ér t, ¯t.on of the dielectric strength * We discovered conceal a Cl'and number (.1 'add1 t: U's which also ncttcmnt the resistance of fwa'67wCL'f T7C, n6y' 1ilS,: <n 'i .. du po2yt:;.: Ne, low density at disruptive breakthrough Such products include polycyclic arolium compounds halo5 and -iér aronatic hydrocarbons subst1tU0S, distinguished by the fact that they carry an electron acceptor group;

     and an electron donor group capable of binding together by a reversibly transferable proton. However, such additives, particularly those which are not pure hydrocarbons, when added in large quantities to the mixture.
 EMI3.2
 polyolefin, may code the dielectric constant and the power factor in an undesirable manner. This is particularly true when the improvement in voltage stability of the circuit requires additives in excess of their solubility.

   Addition in excess on solubility causes crystallation of
 EMI3.3
 the additive in the polyolfine, which creates physical discontinuities and thus the deterioration of the electrical properties of.
 EMI3.4
 1set.



  The Applicant has in fact found that by using the voltage stabilizing additives mentioned above with a 0 ':) :: 1posed trl, aro: âa: .c, ue which can be r <41; ing6 with the polyol {.! 'ine ..



  Co ::. R :: e a: .1 -le l1 '\ ::, ¯'o \ H1.rbonéo nonvolatile, C, a hydrocarbon trus aroz: aiq: eh 1> <, x melting point such that l'orthoterphénjolo ot 'CH} tcr> 1; ÙnyloùJ 1 <élar + c ± s, it is possible cPClbton1r a ntab1-! lisation au volt ::.: t 'e: sccllc: te, for a \.! hus;. '. minimum entation of) the constant d1C'. (: 01.1 '': '(1'10 or the power factor of the camponi ..; tlons of T: O.;,' 4.sf: ïi. ", by G:; Cs: t1). de;, oly6tliylne, resulting 'It {is; fo: s, bw.c, ar eYe: rlo, to obtain results equivalent to! those given by much larger quantities rrz> de: habituudo 1 at least double) of voltage stabilizing additives without pro-.

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 However, there is no change in the dielectric constant or in the power factor.

   In addition, in the event that the additive
 EMI4.1
 is of limited solubility in the matrix of p, ::; rr and, consequently, cannot be alone, it can be dissolved in the aromatic compound with a view to its use.



   We have further discovered that these non-volatile, highly aromatic oils can also increase the voltage stability of the polyolefin, but not always so effectively.
 EMI4.2
 in the proportions 11: 1ite required to prevent deterioration of the other mechanical and electrical properties of the polyolefin.



   Highly aromatic non-volatile oils suitable for
 EMI4.3
 The purposes of the present invention include petroleum aromatic oils having a total content of aromatics and naphthnics of at least about 50% and preferably gas. Suitable oils are Kensol PL-1 (Kendall Oil and Refining) having a specific gravity of 1.038, an aromatics content of more than 65% and a viscosity of 2.72 centipoise at 100 C, and a similar oil viz. CD 101 (Standard Oil of Ohio) which has a density of 1.035, a pour point of -6.7 C, a viscosity of 100 SSU at 38 C and 36 SSU at 99 C, a refractive index from 1,

  601 and an aniline point less than 16 C. The
 EMI4.4
 aroi ,, i.tîques content of the latter oil is greater than 65%. Other oils have :; xo; a3 ,, ys: are Sundex S5 (Sun Oil Ce) which has a viscosity of 14.1 ;. centictokes u. r3 C and a density of l $ 017 and which contains about 48 ;; d-'arosatique 15 ;; of napthténiquos and 37r ;; of paraffins and 'Circo Light 011 (Sun 0.1, Co) which has a viscosity of 4, cont15tokes at 99 C and contains 20% of QrODt1ques, 40% of naphthenic and * 40% of para ±. fine.



   Highly aromatic hydrocarbons with a low melting point

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 which can be used for the present invention in lieu of or in combination with aromatic oils include
 EMI5.1
 for example lIo-te: t'phûny1c "which has a viscosity of 40.6 SSU at 99 C,. distils in the range of 333 350 C, and has a melting point
 EMI5.2
 of 6.3 C.

   The other isomers of tcr1nylo, .lo m-tcrphenylo and p-tcrphunylc, di stü.cx., c: weat.aant, in domain; from 368 to 378 C and 381 C n, 8SoC, but, the high melting points of these co: r.poscs in particular of p-torlih6nylo which is 212 C, make these compounds unsuitable for the purposes of the invention because '' they would separate by crystallization of the polyethylene and adversely affect the electrical properties of the products creating
 EMI5.3
 physical discontinuities in polyethylene. However, mixed terphenyls are suitable. In the latter case, the terphenyls in mixture can be mixed with an aromatic oil to lower the melting point, preferably below.
 EMI5.4
 of 10 C to facilitate handling.

   In addition, biphenyl, anthracene and phenanthrene can be mixed with.
 EMI5.5
 aromatic oil or terphenylc to increase the aromatic content and lower the melting point.



  Active voltage stabilizing additives which can be used alone or incorporated into highly flavored oils.
 EMI5.6
 These include pol.i, hal, ogenated polyphyls and other substituted aromatic hydrocarbons. Examples of suitable polyphenyls polyphenyls include chlorinated biphenyls, chlorinated triphenyls and mixtures of compounds of these two.
 EMI5.7
 classes, as well as brominated polyphenyls, for example 4, 1. "- dibromobiphenyl.

   A variety of polycyclor polyphenyls is for example commercially available in the form of mixtures called
 EMI5.8
 Aroch1or 126i and 1262 (? .Tons <u1to CheIica1 Co) which respectively have specific gravities of 1.538 and 16.6, refraction indices of li630 and 1.651 and viscosities of 44 and 103 (v5) at

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 EMI6.1
 99 C. Other cor ::; os6s = -, o ;; '' hn.1.océn (s COL1p: rerm: 'r:' \ 1:}> 3.i!} L '!'. Fû .:; '(ét antliricénes po ::'; "':::' Ol'J3 i. 1 :. polybror.t ': s and i: a: ve: a.ie23ß :.



  Additives .n1 wt. (W.:r'L:i iA i1 ià.L .3n i aV é ai uf, r ,; lez lîyc1rocarbide., '! Aronatiqucs substitas' 4r.rnlr> iâiud plus lmut, such as 2,4,6-t'tnit-otoluône, 2-n.ltr ..> dLà> hônylaiiine, la, 4 ... dinJ. trodi .... fold lbâI1., ': o: y, " .31 ss.'ëy the,.,;,? 11 '> r9:.:,' <'Sw the 2-' dwnitwato3.uè: e, ::. '"... ni; -1'0 biZ1huy1 .e la b.1.ph '; Í1Y': 1.: ":. ':) 1 2-ni' J:.: ';;) U aaiil1le, a.'1thr = .nilon: tl' llc, the l-: tlUol'o-Z ... ni:!:; roh \ 7: t'l..i: mc "their r.é.i1.'1CcS Oo'1trú them and Ityurs: .l (.l; 1Y <:; e: with the <iipliénylatainù '3t dei; l.'; 'F'. "... ''. vG ': â, for example from dip: .6ny'.a .. llnü with the care of a daring coaj chosen among the! -d.l1trobeLu: tne, the t: l-nit :: Q <nJ.l1ne, the 1 "2ï.trO: .Ti ... ':: lE :, i.; - nit-otoluone, 1e j: -n.trtt3 .: u - :. t ', 1 o-ni trochlxrobenzone, and p-nitrochlorobensene.

   These additives have the following characteristics in common:
 EMI6.2
 1 - an electron acceptor group, specially a strongly unsaturated group, for example containing a common bond - 1102e C0, - CII, phenyl and aromatic polycyclic 2 - an electron donor group, especially a group containing a transf proton (rable, conIT.1e of wnino and lower allryl groups, for example lI.ff2 and -CT;

   
3 - possible hydrogen bonding between the acceptor and donor groups by a transferable proton, such as when the acceptor and donor groups are ortho to each other, for example on a benzene ring;
4 - the reversibility of the transfer of the proton between the acceptor and donor groups, retorted in ketoenolic isomerization;
5 - a structure and bonds between the acceptor and donor groups which promote the transfer of charge and energy
 EMI6.3
 comrie a plane or almost plane structure of a conjugated system of single, .- and double bonds (\ .tol'n6cs, coron; <has an arosatic nucleus;

   à - one dimension and one âY: .e.l. 4 system adequate

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 EMI7.1
 conjugated hair ensure a decctronsct capture a subsequent dissipation of lnoi.gie without irreversible bond breakage 7 - adequate solubility # the additive in the insulating material C'Ld.g 9t "'w' 'a sufficient nonbrc do centras for capture of unwanted con, ar, nant products such as lo3: y- Ecne -q4 1 <;, 5 ± liétr> n5 which move in 1 G:,:, 1 6iéétrLqie> Do taqon 3s. ae? the affinities electronic rewativc; v atomic residues are in the order Cl> 0 <And then we have 0> 11.> 0. The acceptor groups have dicstronic affinities in lrzvre. * N0p> - CU 0 = 0>, plz4uye. The relative abilities of the donor of P61cetrans are -il (Cll,) 2 z - xt3 .. cil phenyl.

   Hairett's sigma and sigitia plus coefficients are an approximate measure of the co; al:; w aeceptors and donors ds3cctro: s skills for atoms and groups. These sisaa coefficients have been destroyed pi. ' many rauteuz's, and special- ient P.R. Wells, Chéi <4cal Reviews p. 171-219 April 1963.,
 EMI7.2
 see tables pages 181 and 189 of this article.
 EMI7.3
 



  The additives according to the invention are particularly effective with polyolefins in the form of palyeth ;, 3.ane, baswe dcnsite which generally have a specific weight of I.eo, 4, dre de Oe 9 aa, 9 and a melt index of 0.2 to 2) 0. The rz4c..4.fs; high density polyethylcnes ("low pressure"), and 1-c-- are also effective in obtaining the rechc effect :: -, ... 'JtR. other N pol; a! '. ne:, by in the io.3. ; propylene. The compositions of polyolcfincs sbilises according to 2.J,., 4nvc, .Itloll can nattrrt-, 7.e: ent corf; eliz of small proportions of the adjuvants and eliarees additives used nori.iale, .- ictit in the compositions of iJolyolCr1noi- , con., o carbon black, pigments, mWi.o: .idants, heat stabilizers, and 10ozono stabilizers.

   The additives are used in addition to the voltase stability of solid polyole-fine compositions which contain low proportions of polynuros and rubbery ol ± fino3, ca:; ;;.: c .isotul; y.: ne ot

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 EMI8.1
 the iso9rsne. In addition, the additives are used with obar poa sitions of pa: .yo; 3, nes which have undergone a cross-linking by excapio using a peroxidic catalyst co .., 2.e the perodade of dcumy3e, 0 le 2, .- bis (tba; .pQroxy.j2, dßmte; llesey .o, , 3 etc ... or by irâadl, 'ova do of the order of 10 to 15 m6Cllrad, for example by means of coba.lt-60 (radiation ar:;. A or tl'u.'1 accelerator 1-Inéaire (radiation buta).



   As the proportion of voltage stabilizing additives necessary for a significant improvement in stability at
 EMI8.2
 The voltage of a polyolufino is generally about 0.1 to 10%, and preferably about 0.2 to. 5.0% of the weight of the polyolefin, an important criterion which limits the possibility of using a.
 EMI8.3
 particular additive is its solubility in the po.yolef.ne, q, u. should be 01% and preferably 02% by weight or more.

   The incorporation of such additives in a proportion exceeding the limit of solubility results in a general deterioration of the electrical properties by creation of physical discontinuities and must therefore
 EMI8.4
 The addition to a polyolefin of 0.1% by weight of solid additive and of 2.0% by weight of a non-volatile aromatic oil, based on the polymer, gives an insulating composition particularly effective for: high tension power cables.
 EMI8.5
 



  The additives are chosen from, xfrenee so that they can be incorporated into the JSI.l. "0.'LIl'C. ' ût: .. deconposition of the pOl: r ::: ùro "ni vol: lt.tlisatton of iad'd3.t3. TOC; J1; \ C temperatures of 1.9 G 20lY C are used to satisfactorily roll out polyol-finos with 4-dose additives which are solid at room temperature preferably have the property of be liquid and have a low vapor pressure in this
 EMI8.6
 temperature range.

   In con> 6qaenco, the stabilizers preferably have a melting point less than .S, 7ijaV / and a boiling point greater than about 149 C. t Additives stabilizers

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 EMI9.1
 which are liquid at the temperature abinntecon.M! the aron.tiquos wings can be incorporated into the pulverulent or sranular polyolcfino by churning or by other techniques which do not require high temperatures.



  The no.-slow additives which are solid at normal temperature must not be -; ± lw: jls hot with the polyolfin when present or with aromatic oils
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 because these dissolve the solid additives to give
 EMI9.3
 z7 <ln; n; es l.azz.de: easy ri to incorporate in the pulverulent polyolefino by churning or otherent.



  A wide variety of proportions can be used to polish the preparation of neians from non-volatile aromatic oil or other aromatic hydrocarbons with stabilizing additives.
 EMI9.4
 voltage sators. The proportions chosen are those which
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 are the most economical although other variations of efficiency may influence the choice of proportions. From just 5 parts by weight up to 40 to 50 parts by weight of a solldet Io 2,4-dinitro-) toluone additive or polychloropropylphenylo can be used in 100 parts by weight.
 EMI9.6
 
 EMI9.7
 aromatic or orthoterphic oil.



  A forward-looking and effective mixture comprises 25 parts of the additive per 100 parts of oil or aromatic hydrocarbon. In practice) it is advisable to apply a semi-conductor shielding to a stranded conductor; zfor example
 EMI9.8
 copper, to reduce the possibility of a discharge
 EMI9.9
 electrical in the cavities between the conductor and the inside face of the insulator which causes a deterioration of the didiecetric.

   The twist armor appold blindase, is typically an extruded coating of a sea-conductive polyolfin, for example poljr6tl "I'll; nc containing low amounts of a cc ': ^ C material. , 'Ll.C'f: riC, al ::: C. Curry black> ot> JmD <: 5 pol.:/o1ôiLne5 solids are ;; c, e: ..: at ut.? 3 .:: s conje gain oo due cubiez to which

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 EMI10.1
 water) they are 1 "rt: q, uc; mJ3t a:!: zc: es with black ne c é: oz ':, or other pigruntso According to the present invention, we can ar:; Gliorer co # sideably the breakdown voltage of the polyolefin insulation of a
 EMI10.2
 high voltage cable added a certain proportion of the
 EMI10.3
 r.6 mixtures of oils and additives described in plus 1;

   ai ",>, - one-twist blindase a; ti, 6> layer, .Si.-çOnr., t2'i'â (ie èv, .. :: ¯. ', i' 2110" i's.hsV .tm that the cable sheath has if it is based on 5:; no pclyolcf prompting given, that these blindascs are in the zone of the greatest risk c;, rax., rfect.mz ::, the quantity of stabilizer is larger .. than in the insulation The Applicant has observed that 2 to 20% and in particular approximately 1% by weight of the mixture of oil and additives are suitable in the case of a composition for sentencing.
 EMI10.4
 driver.
 EMI10.5
 



  Such shielding can be improved from the polyolefin than that used for the insulation or of another type which can
 EMI10.6
 be extruded and containing for example carbon black which
 EMI10.7
 makes semiconductor A shielding composition may be formed from a copolymer of ethylene and an acrylate containing 30 to 10 parts of solid carbon black. -conductor per 100 parts by weight of copolymer, which gives a resistivity of about 100 ol1om. A weather-resistant jacket for a cable may be made of the polyolefin as that
 EMI10.8
 used for insulation or., if desired, any other material
 EMI10.9
 resistant to intenpuries and easily applied to the cable.



  I, A weather-resistant black natiro comprises, for example, polyethylene, having for example a specific gravity of 0.92 and a melt index of 0.3 in which there are incorporated about 2.5 to 3 parts of finely divided and well-dispersed carbon. of an average eranulo = sort of about 10 to 20 microns, per 100 parts by weight of polyethylene.

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  : ..j- :. ' ' at'. .
 EMI11.2
 To illustrate the ineffectiveness of stabilizers !; following
 EMI11.3
 the invention is 1'01 ': 1.' :: a. 61 stranded bare copper cable (177 mm2) by wrapping it by extrusion of a shielding in inch. A 1: ci # tion is adjusted by extrusion on the armor and includes 1 = n-16 min polyethylene wall (density
 EMI11.4
 0.92 melt index 0.3) containing a trace of an antioxidant
 EMI11.5
 and 2, bµ1, the weight of pozytti) ylene, with r :) 1¯no of 25 parts
 EMI11.6
 by weight of Aroclor 1260 of 100 parts of Kensol PL 1 oil.
 EMI11.7
 



  A semi-conductive nylon rutrn and a copper tape of a
 EMI11.8
 
 EMI11.9
 0.102mm slider are coiled and helical on the insulation. A protective lead coating on a 0.25 / mm penisHeur
 EMI11.10
 
 EMI11.11
 and a non-weatherproof polyethylenc <? high molculf'.1.re, thickness u,: 'l mm, are extruded on the insulation shield. The resulting IC ') which has an outer diameter of 6, j5 en and weighs 9, a kC per meter is suitable for a rûse3u at 69 KV with neutral to earth (40 KV to earth) with a power of 45,000 KVA (100, é).



  Lr,:) Ltj) tr, c7l'.tt de la r ± :, Stfa314r> ti113C vol illC (lL '! Fitcynn'- tflfli of polyJthylLnc EVCC additives on that of the same polyth: lù1 \ f without additives spring by comparn1on. 1..cr1) â ce c; i;:, on Gt7I'al. pi;, ci <uri tGlrâ t ... t?! 1 .. copper wire M;: 1j 'tic! 2JO 'mu wearing a-' '' ..-: '. I! : Ct..llt., Ùn, iâ. ;; c 4 il bli! 1er; denn1tû f.1 ') lrï' ± ts, ti: 1 "= u: (h! ;; ', 0 3;': : l '^. s Dl:! i;.; a w'F; Wiy 1 <: ply'thylenc contains i,>, µ C1f' not poiup du ;;, 11;: nje of 2: '3atT'. .t:; by weight <1 ';; 1'00107 "1;' Ó0: t <. + to 1" JJ; 4.rti,.; e on po1u: J; le ± \ (: 11 :: 01 PL 1 while which; 4, is 1 ';: uti c; the additive was omitted.

   Sour 1 <1:> '' cunntillons jont s: rtJ. =: ;;;, ni ttt :: 1: conni ti /) JW 1ncnt1 (: UHf,;, clfcaac3'c at 50 KV (60 cycles) ot pn .'tito all lis <:: 1n., minutes, 10 vo1tnlù c; t au,;. n <3nt, 'du;', 3 iliiv If '! i'F, .. theyll 1 gives the results of a test out of two, in pcu: c ± Âatrt d lc rf: 3tillanâ not having rD1ct at essni.

   

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   BOARD
 EMI12.1
 
<tb>
<tb> Test voltage <SEP> <SEP> KV <SEP> 50 <SEP> 60 <SEP> 70 <SEP> 80 <SEP> 90 <SEP> 100 <SEP> 110
<tb>
 
 EMI12.2
 Polyethylene + additive 0% Oft 0% 10% 20% 50% 90% Polyethylene without additive 20% 50% 55% 65 1005 100% 100%
The improvement in dielectric strength in alternating current attributable to stabilizers is also shown by tests the results of which are given in Table 11,
 EMI12.3
 for cables insulated by 5.03 mm of polyethylene (density 0.9 melt index 0.3) containing in one case 2.5 # of its weight of the mixture above dyitroclor 1260 and Kenzol PL 1 and free from this additive in the other case. The cables are dried at room temperature and the voltage at 60 periods is raised by 10 KV every 15 minutes.



   TABLE 11 ----------
 EMI12.4
 
<tb>
<tb> Without <SEP> additive <SEP> With <SEP> additive
<tb>
<tb> Time <SEP> for <SEP> the <SEP> breakdown <SEP> Time <SEP> for <SEP> the <SEP> breakdown <SEP> in
<tb> in <SEP> minutes <SEP> at <SEP> voltage <SEP> indicates <SEP> minutes <SEP> at <SEP> voltage <SEP> indicates
<tb> KV <SEP> min. <SEP> KV <SEP> min
<tb> 98 <SEP> 1 <SEP> 107 <SEP> 58 <SEP>
<tb> (1)
<tb> 63 <SEP> 1.5 <SEP> 106 <SEP> 14
<tb> +
<tb> 97 <SEP> 144
<tb>
 
 EMI12.5
 (1) The voltage must be d1m1nu;, it causes experimental difficulties.



  Further tests have shown that the dielectric or current strength of these intillons in water, together with that of dry chlorination, is about 92% for the bVUC polyethylene bauitive.



  The 'l'nDlt: l1u III shows .'rxpt, itua of polyethylene it withstands in a dry environment relatively high voltages in direct current for the duration which is increased by the use.
 EMI12.6
 tion of the additive. The cones are made of solid copper

 <Desc / Clms Page number 13>

 
 EMI13.1
 2.906 m: n portlmt uno layer (the 2,? 4 mm of OOIY-tl'Ylèr-0 and are the number of dy pà1- test.



  The stab111fHiut mixture is the same as in Tables and II and the concentrations are the same.
 EMI13.2
 AHLi.dIU lU -----------
 EMI13.3
 Hours ju:; nu'.u slammed at 700 volts! .. pt1r O "O ::: 5 /. Mm.



  Type of insulation. (Ma yen; iù loenr1 thmi'1uo)
 EMI13.4
 
<tb>
<tb> sample <SEP> sec <SEP> temperature
<tb> ambient
<tb>
 
 EMI13.5
 Poly4thyl: no
 EMI13.6
 
<tb>
<tb> a) <SEP> with <SEP> addendum <SEP> 7.700
<tb> b) <SEP> saxxs <SEP> additive <SEP> 12.000 <SEP> #
<tb>
 * three out of four samples are still in good condition at the end of the test.



   The addition of the stabilizers of the invention does not appear
 EMI13.7
 not increase the dielectric strength of polyethylnp. impulses. However, this high rigidity is evidenced by the ability of the 69 KV polyethylene cable described above, with 16 mm insulation, to withstand a negative pulse voltage of 1,000 KV 1 - 1/2 X 40. The level Basic insulation of the 69 KV pulse cable is 350 KV.



   In addition, the polyethylene insulated cable with or without additive is needle tested. (Transaction AIEE Paper n 62-54 "An Accelerated Screening Test for Polyethylene High-
 EMI13.8
 Voltage lnsultt3.ont, D.W. Kitchin and z, Pratt). In this test, the relative dielectric strength is determined by means of a nomnalis4 defect and the probable life under tension of the polyethylene is assessed by observing the formation of a dendrite, which is admitted to be the first stage of breakdown. electric. The failure
 EMI13.9
 normalisa "is a needle coated in a sample of polyethylene under defined conditions. The eswai consists in applying a tension between the needle and the tC1, ']' f.:.

   We observe

 <Desc / Clms Page number 14>

 
 EMI14.1
 dendrites under the microscope. The voltage for which ': 1.1tl'l' :; on eight of5 cha.nt111on. ::> taken in duplicate conceal rie tel1, ;; 'ÎB, tL'Î.:' '::; 1in 1% ne lieure is chosen com: M le J1v :):' t: 1C - ::: ar (. \ Ct0rtJt1 ... 1j. 'Ù. Sn> hour ", The results of this test agree with the durability tests of cables. It is thus for polyethylene with additive and for the pny.atiy.; nc n classic composition * The, err.i. li 4A "are given Zli, iaw? 1 Table IV.

   N Lr ¯ ui,. s? iw3 the I: 1bi..t1.u lll, the polYIthïl, 1 ..; is low 4ùn: 1 ', tee ::; 4d; index of f ''. iit 0.3) and the t.f, L1t1.f which represents 2.5 # of the polytbylf.:n1 is a m6J. ±! 1!.: of 25 parts by weight of ''! '(Jclor 1260 and 100 parts in poios do: I \ (> n ::: o1 PL 1 ,, TABLE IV
 EMI14.2
 1 e 0 l t-, nt- DU1 "/. E de viEJ 01.tS ten:

  d.on Test at laipu.lie
 EMI14.3
 
<tb>
<tb> a) <SEP> wire <SEP> in <SEP> water <SEP> at <SEP> Voltage <SEP> character temperature <SEP> amhiante <SEP> ristic '<SEP> at <SEP> a
<tb> b) <SEP> 230 <SEP> Volts <SEP> per <SEP> 0.0254 <SEP> mm <SEP> hour
<tb> '<SEP> Time <SEP> of <SEP> breakdown <SEP> in
<tb> hours.
<tb>
 
 EMI14.4
 f2! l !!! l !! l
 EMI14.5
 
<tb>
<tb> a) <SEP> without <SEP> additive <SEP> 930 <SEP> 23
<tb> b) <SEP> with <SEP> additive <SEP> 2.900 <SEP> 46
<tb>
 
 EMI14.6
 ± XMPLE 2.-
Table V gives the results of the tests by the needle procedure for other polyethylene compositions according to the invention.

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 EMI15.1
 



  T.Li ,, U #
 EMI15.2
 ---------
 EMI15.3
 Pclyithylène Additif $ Additif Voltigé cà ra c ter r ti zuc Jc cr <; 1 s se: a ;; f,:,: oj;.:> N of volt- pe p '!' L '..¯-3: 61% .t "4 le rupt.u: - # y 7 'i ::: t: V lu i. # S 1:;> 15 i -; - i -: - fjr l1r! +: ¯x .. Ìx = ce 0 '>', "- o .i 4." ë.2¯ ^ C ': ni,' ī'Fa n> <1 = ii'Index. ' s, à.1 "Z: .3, t., Vw K ±, xirc; 1 PL.-1 Po: c :. ' ::.:, i-x: ¯u. il, b> L f.rac l c 1. 12 Cl 1/2 46 Index ce flr; .r, i 0,. <: c-ct.



  Weight i> ëcifl,: u <: O, 9 J.roclor 126J 1/2 40 Index ce fluidity 0.3 Kensol PL 1 2 Weight à-p / cifii; uo 0.9'- dipl.nylH1Ïne 1/2 60 8E> 4 t; .C.ot., 4 Inoice de ï.ïuiait 0.3 51 <.nsai PL 1 2 11, ....



  Poià stoi, üe 092 4 .. "t 1. 1/2 60 '39 '"' "ea'c 5 ....

 <Desc / Clms Page number 16>

 



   As indicated above some additives are substituted aromatic hydrocarbons comprising a group
 EMI16.1
 electron acceptor and an electron donor group capable of binding reversibly by a transferable proton. The Applicant is led to believe that the mechanism by which these additives
 EMI16.2
 prevent electron avalanches in insulating polyo14fins is as follows in the case of o-nitrotoluene. In the case of leo-nitrotolubno, the acceptor group is the nitro group and the donor group is the methyl group.



   The donor and acceptor are in such a position that they can form a hydrogen bond between the proton of hydrogen on the methyl group and the Ò-bonded oxygen atom of the nitro group of the atoms form a ring in the same plane as aromatic carbonyl. This proton is potentially transferable and the transfer is reversible. The length of the
 EMI16.3
 "Hydrogen bond" is approximately twice that of the sigma (o) bond between carbon and hydrogen atoms.



  The structure between the acceptor and donor groups is roughly flat, and the atonies in the ring between the N atom of the acceptor group, and the potentially hydrogen bonded O atom of the group
 EMI16.4
 donor, including the intermediate C atoms are united by a system of alternately single and double bonds * This ring is further united to the benz ring, ni (, ue conjugated and is part of it, ensuring a dimension and complexity appropriate to the capture of an electron and the dissipation of energy without irreversible bond breaking.



   An electron arriving at any weight from the
 EMI16.5
 structure is easily transferred by the system conjugated to the part of the inolL * Ctllcj which has the greatest aff1ni tf.1 for the electron, i.e. to the nitro group, in particular, to the atom of oxygen of the nitro group joined by hydrogen bonding to the methyl group.



   After the electron has soured towards the atom with the

 <Desc / Clms Page number 17>

 
 EMI17.1
 highest affinity for 1) lectrori ,, i.tii, therefore cFz3, is the rr-bonded ü'rxy4.ne atom in the group most attracting the hiectron, namely the rump -No2y the 41ecti <on capture causes the transfer of the proton from the hydrozene bond to the oxygen atom and the latter in turn redistributes electrons between the donor and acceptor groups through the int, -rm (- 'cilium of the benzene systene (read, after which the pair of electrons,) which maintained pri: aivuxent the proton on the methyl group., is dt ,, ich-le, to form an n bond, between the carbon atom
 EMI17.2
 of the methyl group and the carbon atom of the benzene ring
 EMI17.3
 annual this group, it - 'thyle is li.

   The original distribution of 'electrons, in the nitro group and the benzene ring., Is thus replaced by bonds only if ,,,, ma, between the nitrogen and oxy atoms; ene of the nitro group, a pair of electrons without
 EMI17.4
 bond on the nitrogen atom, and a pair of electrons without
 EMI17.5
 bond on the carbon atom of the benzene ring connects to the nitrogen atom. It should be noted that the general rncrc occurs in a combination of molecules, where the receptor and donor groups are found on adjacent molecules but
 EMI17.6
 separate and possibly different.

   Examples of possible combinations are:
 EMI17.7
 To be used alone or For Stro used only in combination, with by in combination with, for example, dil1h,! NylH11ine plot of <iiph <3nylamine a-ni troaniline nt-dinitrobenzene o-nitrotoluene m-nitroaniltne 2,4 -dinitroaniline p-nitroaniline m-nitrotoluèno
 EMI17.8
 
<tb>
<tb> p-nitrotolùene
<tb>
<tb> o-nitrochlorobenzene
<tb>
 
 EMI17.9
 p-nitrochlorobenzene 1
 EMI17.10
 
<tb>
<tb>
<tb>
 

 <Desc / Clms Page number 18>

 
The compounds indicated to be used only in combination, do not meet the general conditions indicated above, which must be met by the additives, and are in themselves poor voltage stabilizing additives.



  In combination, the acceptor and donor groups of adjacent molecules bind together and form effective stabilizers.



  The proportion of additives used in combination is variable, but equimolecular proportions are preferred, in order to allow the acceptor and electron donor groups on the different additives to group together in pairs, so that the bond can occur between adjacent molecules but separated, particularly when the arrangement of the acceptor and donor groups on the individual molecules is not such as to allow hydrogen bonding.



   Other materials within the scope of the invention accept an electron as does o-nitrotoluene. Considering 2,4-dinitrotoluene as an example, the nitro group in position 2 can capture an electron which moves in its vicinity under the influence of the electric field in the insulator undergoing dielectric stress. This situation would be stabilized by exchanging a proton from the adjacent methyl group of the toluene molecule. Then when the electron is released (at low energy) the proton reverts to the methyl group and the dinitrotoluene returns to its original state and can continue to act in the same way.

   According to this hypothesis, 2,6-dinitrotoluene would be a better stabilizer than ^ 4,4-dinitrotoluene, :: since the first has two nitro groups adjacent to the methyl group, while the second has only one. alone in this position. The experimental results show that this is indeed the case. Likewise, anthranilonitrile is in accordance with the general description of the present invention, the cyano group acting as an electron acceptor, and the horned amino group a proton donor.

   The general description of the

 <Desc / Clms Page number 19>

      The present invention is further supported by a comparison of the
 EMI19.1
 2,6-Oinitroaniline with. 3,5-ainitrJaniline and 2-nitro-atlilwna with 3-nltroaniline, where in both cases the a; nino group acts as a proton donor. Again, the stabilization max1mul'1 occurs when the nitro buttocks are adjacent to the proton donor on the ring structure.

   According to the principles of the present invention, it is obvious
 EMI19.2
 that the substitution of a nitro group on d1phf: nylaminc, in position ortho to the amino group, makes it a particularly effective additive, and that the result is exactly as expected. Again, the overall reaction is
 EMI19.3
 reversible and after the absorption of a Gnerjetic electron, which helps to avoid the formation of an avalanche of electrons, the stabilization molecule releases the electron and recovers its sound. titude to capture electrons.



   The examples below illustrate the increase in voltace stability that aromatic additives allow.
 EMI19.4
 su1ntitués chosen according to the invention. EXAMPLE 3 -
 EMI19.5
 A number of tests, rsun: s in Table VI confirm 1f1 st..bili t: at long voltage dU1'e, at different voltaces; 'qUM pï's'? ntent compositions di, luctr1 (IUêlJ containing iin poly \ th>, l "1' \ do bttue i3 6005 (denu1tr. Z, 92, melt index 0,: 3 and con1 ..: t1hnt a tract: 'of an antioxidant crmrcac.irz7 ..



  A t.6rio of eight c: ':: H1, i is OX1CUt't:> for chll'1uQ composition.



  The prem10rtJ: cizztnti "L3.orts are constituted by poly.; Tt1ylm DFD 6005 SMis c..icit.i 'stabilizer of your ... ta; t>. The other compositions (jxnt.1intG contain uu po'4.y , -thyIZ4ne and Oe5lr'el by weight of an additive ztE.bil1sht'JUl 'ae voltili, e (except.' exception indicated). All samples containing additives are prepared by mixing,, in a crr.ui grinder , at tem1Jratures S1tU0us between 1.G3 C and C'C and are idont1 ': ul3 $ in shape and size,

 <Desc / Clms Page number 20>

 
 EMI20.1
 Each sample was subjected, at the ts: 5xature abianto, to a regular alternating voltage and the appearance of a high voltage rupture examined, by the needle test described above.
 EMI20.2
 
<tb>
<tb>



  Number <SEP> of <SEP> breaks <SEP> in <SEP> one <SEP> hour
<tb> on <SEP> eight <SEP> samples
<tb> test voltage <SEP> <SEP> - <SEP> KV
<tb>
 
 EMI20.3
 Additives 18? 0 23 20 i: .Q jQ 60
 EMI20.4
 
<tb>
<tb> None <SEP> 4
<tb> 2% <SEP> 2,4,6-trinitrotoluene <SEP> 0 <SEP> 3 <SEP> 5
<tb>
 
 EMI20.5
 ortiiom, bthy1elnisole 5
 EMI20.6
 
<tb>
<tb> 2-nitro <SEP> diphenylamine <SEP> 000
<tb>
 
 EMI20.7
 2.4-dînitroanisole 0 6 2-methoxy-4-nitroaniline 0 8 4-methoxy-2-nitto> miline 0 8 2,4-din1trod1phenylamine 0 0 '1
 EMI20.8
 
<tb>
<tb> ortho <SEP> nitroanisole <SEP> 002
<tb> chloranil <SEP> 3
<tb>
 
 EMI20.9
 216-din1trotoluno 0003
 EMI20.10
 
<tb>
<tb> 2.4, - dinitrotoluene <SEP> (techn.) <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 8
<tb>
 
 EMI20.11
 2, / * - djnitrotoluene (techn.) (Rsnouvblé 037 orthonitï'ofUphunylû 003 2,

  4-din1trochlorobenzna 4 7?
 EMI20.12
 
<tb>
<tb> diphenylamino <SEP> 002
<tb> 2-nitrouniline <SEP> 0 <SEP> 5
<tb> 3-nitroaniline
<tb>
 
 EMI20.13
 nthrnilonitril0 0 1 1 3> 5-dinitto <, nilino 7 2,6-dillittOliililillS 1-tluoro-dinitrobezi ,, iene 0 0 We transpose the improvements in dielectric strength, obtained by the incorporation of small amounts of additives

 <Desc / Clms Page number 21>

 voltage stabilizers below, to samples manufactured on an industrial scale. A number of straight batches were made giving long lengths of 15 KV strength cable insulated with polyethylene containing additives of the type described.

   The results obtained in tests carried out on samples from these production batches are considerably superior to the results obtained in similar tests carried out on cables insulated with normal polyethylene not containing voltage stabilizing additives.

   These remarks apply particularly to live life tests and are striking in the case of really long life tests, such as the live life test, in which a sample cable is held at a voltage of 2.5 times the operating voltage until rupture occurs. As a result of this stress life test, polyethylene containing voltage stabilizing additives is 5 times more durable than unstabilized polyethylene or more.



     EXAMPLE 4.-
The additives of Example 1 together with polypropylene and polyisobutylene give stability properties if they are mixed with the polyolefin used in an amount of 0.5 to 2% by weight of the polymer.



   EXAMPLE 5. -
To illustrate the voltage stabilization effect of a combination of additives, a needle was tested on polyethylene, similar to that of Example 3, and containing 1/2% of a. mixture of equal parts of 2,4-dinitrotoluene and diphenylamine. There is no breakage at the voltages of c; proof of. 50 XV and 60 KV.



   EXAMPLE 6. -
Other additives giving similar voltage stability in polyethylene when combined in proportions

 <Desc / Clms Page number 22>

 
 EMI22.1
 JquimolJcul.:1ire with d1ph \; nylA.min to force a: r. = Lane which is incorporated into the polyethylene at a rate of 0.5% of the weight of this polymer are;
 EMI22.2
 o-nitroaniline n-dinitrobenxene o-nitrotoluene m-nitroanilne 2,4-dinitrotoluén; p-nitroaniline iin.-n.iti '= ci lâ: Iie p-nitrotoluEne o-nitrochlorobenzene p-nitrochlorobenzene
The following Table gives examples of other additives used in accordance with this invention as stabilizers.



  In each example, the additive is mixed with a polyethylene, whose density e, st of 0.92 and the melt index of 0.3, which contains a trace of commercial antioxidant. The mixing as indicated above is done in a hot grinder between lb3 C and 204 C.
 EMI22.3
 
<tb>
<tb>



  Parts <SEP> in <SEP> weight
<tb> of additive <SEP> for <SEP> 100
<tb> parts <SEP> of
<tb> Example <SEP> n <SEP> Polyethylene <SEP> additive
<tb>
 
 EMI22.4
 7 phe: nyl-alpha-naphthylami, rie 2 8 diphpnyla'nine 61 9 phc: nyl-bdta-naphthylarn.ne 5 10 Ne N 3 -diphenyl-parapli, - nylene diamine 5 11 d1paramethoxy-diph (nylamine 2
It is already known that a certain number of paraffins and chlorinated hydrocarbons have an effect as voltage stabilizing additives with polyolefins and especially polyethylene.



  The stabilizers according to the invention comprise certain halogenated aromatic compounds of which this property has not yet noted
 EMI22.5
 known. Coninie indicated above that the polyphnylp.s polyhalozn6s have

 <Desc / Clms Page number 23>

 
 EMI23.1
 this effect. 1, n l) t: h \ / 1n \ eresse has opened>? Ertl, :) '1cnt that 2.-bro;,. OnGy, tala: nc t't l-iodobiphr1yle are suitable for this purpose.



  One will find below examples of solid dielectric compositions affording the invention which have high stability; voltage is imparted by these latter two stabilizers.



  EXAMPLE 12. -
 EMI23.2
 t; c:> c: high density polyethylene PF llb - 127 C, weight sp '; cif1! ue 0.94 obtained by polymerization of ethylene in the presence of a chromium oxide-silicon oxide-oxide catalyst alum3.n.ur at 66-232 C under 0 to 49.2 kg / cm2 on a manoMeter. additive gXF: 2-bromonaphthalene, 1% by weight of the polymer.



  EXE '-' PLE 1.3.- Frr: 4ē: po1ypropylene isotacti'luc P.1. 154 C, obtained "ai, polymerization of propylene in the presence of 1-itane tetrachloride and trit: thylalufIlin1uJn at 60 ° under 21 to 10.5 kg / cm3 on a manometer.



  M: .li: U .. ±: 1-ioaonaphthaine, 0.5) b of the weight of the polymer.
 EMI23.3
 



  FY :, 1PI; 8 1A. -
 EMI23.4
 '1: low polyethylene denFit4 specific weight 0.92, melt index 1.5, obtained by the "high pressure" process and
 EMI23.5
 similar in all respects to po.r> ¯thyl.Gn: A.



  , t, t '2-oror: 1onaphth <l1ne, ±!: 1;. ;; weight of the io.pn2 re The following table gives a number of examples
 EMI23.6
 of conposition of polyolcfins according to the invention which contain! voltage stabilizing additives m4lFnas and which have superior properties (.t2 ai.; cct: ri'iUH5. In; ..: ne! 'nl, we proparc the cO! .1po..itions in ncl7rx; cunt un adaitii 'oily and a solid additive in the prescribed proportions.

   The mixture is then introduced
 EMI23.7
 liquid a> 1nrnt1 tl. prescribed in a euvo d fl1 taUon in the cell, the polyol was introduced beforehand, the polyolei, 1- 'r is not crnnlll'11'1! 1 and aosorbed the mt: na by aùitàtion, Then the composition obtained is molded by extrusion to form the insulation

 <Desc / Clms Page number 24>

 sons. The churned compositions can be injection molded or otherwise hot pressurized.



  In each example, 100 parts by weight of the polyethylene are used which is a low density polyethylene (0.92) having a melt index of 0.2 and comprising about 0.1% by weight of p-phenylene. diamine as an antioxidant. It has been found advantageous to heat the mixtures in order to prepare them. A temperature of 70 to 80 C is sufficient to increase the speed and ease of mixing.

 <Desc / Clms Page number 25>

 
 EMI25.1
 



  Stabilizer additive Example n Polyolefin Quantity of oil Solid Weight ratio
 EMI25.2
 
<tb> mixture <SEP> solice-oil
<tb> (<SEP> parts in
<tb> weight)
<tb> 15 <SEP> Polyethylene <SEP> A <SEP> 2 <SEP> CD <SEP> 101 <SEP> 4,4'-dibremobiphenyl <SEP> 10 <SEP>: <SEP> 100
<tb>
 
 EMI25.3
 . l Polyethylene A 2 0-terph- 9,10'-dibro.io- 5: 100
 EMI25.4
 
<tb> nyle <SEP> anthracene
<tb>
 
 EMI25.5
 17 Polyethylene A 1 mixture of 4-broobiph (nyl
 EMI25.6
 
<tb> terphenyls <SEP> 5 <SEP>: <SEP> 100
<tb> 18 <SEP> Polyethylene <SEP> A <SEP> 1 <SEP> Sundex <SEP> 85 <SEP> 4-iodobiphcnyle <SEP> 20 <SEP>: <SEP> 100
<tb> 19 <SEP> Polyethylene <SEP> A <SEP> 4 <SEP> oil <SEP> light <SEP> diphenylamine
<tb> circo <SEP> 40 <SEP>: <SEP> 100
<tb> 20 <SEP> Polyethylene <SEP> A <SEP> 10 <SEP> CD <SEP> 101 <SEP> 2,4,6-trinitrotoluene <SEP> 5 <SEP>:

   <SEP> 100
<tb> 21 <SEP> Polyethylene <SEP> A <SEP> 10 <SEP> CD <SEP> 101 <SEP> 2-nitro <SEP> diphenylamine <SEP> 50 <SEP>: <SEP> 100
<tb>
 
 EMI25.7
 22 Polyethylene A 6 Kensol PL 1 o-nitroiscle 20: 100 23 Polyétbylene 1: .. 8 o-ter- 2, -dir¯i vro-
 EMI25.8
 
<tb> phenyl <SEP> toluene <SEP> 10 <SEP>: <SEP> 100
<tb>
 

 <Desc / Clms Page number 26>

   Stabilizer additive
 EMI26.1
 
<tb> Example <SEP> n <SEP> Polyolefin <SEP> Quantity <SEP> of <SEP> solid <SEP> oil <SEP> Weight <SEP> ratio
<tb> mixture <SEP> solid.oil
<tb> parties
<tb> weight
<tb> 24 <SEP> Polyethylene <SEP> A <SEP> 2-1 / 2 <SEP> oil <SEP> light <SEP> circo <SEP> 2,4-dinitro-
<tb> + <SEP> 10% <SEP> in <SEP> weight <SEP> of <SEP> toluene <SEP> 25 <SEP>:

   <SEP> 100
<tb> biphenyl
<tb> 25 <SEP> Polyethylene <SEP> A <SEP> 5 <SEP> CD <SEP> 101
<tb> + <SEP> 20% <SEP> in <SEP> weight <SEP> nitrodiphenyl anthracene. <SEP> amine <SEP> 40 <SEP>: <SEP> 100
<tb> 26 <SEP> Polyethylene <SEP> A <SEP> 8 <SEP> Kensol <SEP> PIl <SEP> 2-nitroaniline
<tb> + <SEP> 5% <SEP> in <SEP> weight <SEP> of <SEP> 10 <SEP>: <SEP> 100
<tb> phenanthracene
<tb> 27 <SEP> Polyethylene <SEP> A <SEP> 2-1 / 2 <SEP> CD <SEP> 101 <SEP> anthranilonitrile <SEP> 25 <SEP>: <SEP> 100
<tb> 28 <SEP> Polyethylene <SEP> A <SEP> 5 <SEP> Cu <SEP> 101 <SEP> 2,6-dinitroaniline <SEP> 25 <SEP>: <SEP> 100
<tb> 29 <SEP> Polyethylene <SEP> A <SEP> 2-1 / 2 <SEP> CD <SEP> 101 <SEP> 1-fluoro, <SEP> 2nitrobenzene <SEP> 25 <SEP>:

   <SEP> 100
<tb> 30 <SEP> Polyethylene <SEP> A <SEP> 1 <SEP> CD <SEP> 101 <SEP> mixture <SEP> equimolar
<tb> this <SEP> diphenylamine
<tb> and <SEP> m-dinitrobenzene <SEP> 25 <SEP>: <SEP> 100
<tb>
 

 <Desc / Clms Page number 27>

   Stabilizer additive
 EMI27.1
 Example n Polyol # 'fine Quantity of solid oil R1? Ppot pond / r-1
 EMI27.2
 
<tb> solid-oil <SEP> mixture
<tb> parts <SEP> in
<tb> weight
<tb>
 
 EMI27.3
 31 '01.;>: ":. ;; i> ..- ôe 10 Kensol PL 1 equimolar mixture of aliphenylanine and n-nitrotoluèil 5 x: 1C3 32 Pcli <-etl: ylé.> * .1 5 light oil: : ltla: 1st lquLl01aire waxo z- 5, o en de d4-mhCnyl & .-, iine and
 EMI27.4
 
<tb> <SEP> weight <SEP> p-nitrotoluene <SEP> 40 <SEP>:

   <SEP> 100
<tb> naphthalene
<tb>
 
 EMI27.5
 33 Pol;:; th. I'lÎ ;; l 'j CD 101 equirnolpire mixture
 EMI27.6
 
<tb> of <SEP> diphenylamine <SEP> and
<tb> o-nitrochlorobenzene <SEP> 10 <SEP>: <SEP> 100
<tb>
 
 EMI27.7
 34 .o.: I 'r = -. :: t. A 10 c-ter-, jh nyl equinoleir mixture of diph (.: Nyl? ¯1i.ine and p-: a-i trochlorobenzene 20: 100 35 Polyethylene A 2-1 / 2 CD os phenyï alpha
 EMI27.8
 
<tb> Naphthylamine <SEP> 25 <SEP>: <SEP> 100
<tb>
 

 <Desc / Clms Page number 28>

   Stabilizer additive
 EMI28.1
 Exenole no Pcly ci: fi :: e Amount of solid oil Weight ratio
 EMI28.2
 
<tb> melagne <SEP> solid: oil
<tb> parts <SEP> in
<tb> ¯ <SEP> ¯ <SEP> weight
<tb>
 
 EMI28.3
 36 Poly ': t .. "1'lB:' le A 2-1 / 2 CD 101 phhenyl beta nphtyline 25: 100 37 Polyt: l: 1t; '} f:

   A 2-1 / 2 CD 101 N -.lie cïiphny3
 EMI28.4
 
<tb> paraphenylene
<tb> diamine <SEP> 25 <SEP>: <SEP> 100
<tb>
 
 EMI28.5
 38 Pol; eti> ;. 15.i = 1 2-1 / 2 CD ICI dip3.ra .. '1léthxy diphenyl, :: line 25: 100 39 Pol)' ': t: l'l: e A 2- 1/2 CD 101 diph {, nyla.11ine 25: 100 0 Poly0t3à.léae À 2-1 / 2 CD 101 2, ± -dinitrotoluéne 25: 100 41 Pa.;:: Len :: 2-1 / 2 CD lJ1 25: 100 equif.101ecular mixture of o-nitrobiphëayl and diphenylene with iainin

 <Desc / Clms Page number 29>

 
 EMI29.1
 1! # .: 1eJt ,; 4.-: Uhc due pOlycithyltno (density 0.9e, melt index 0.3) containing Z.5, 'J by weight of carbon black and 2.5 by weight of a!': 1.ann:,: e containing 1UO partios eri weight of Konsol PL 1 and 25 parts by weight I Arochlor 1260 shows a great stfh:!. l1 t !: on the fly kills !: '.



  Failure test at 15 minute intervals, starting at 30 1 .V and increasing by 10% the voltage held constant for 15 minutes each stage, gives the following results:
 EMI29.2
 with mlan; c. without tn2'lange dend (i1tîre c3aW iitif;
 EMI29.3
 
<tb>
<tb> Voltage <SEP> max <SEP> 80 <SEP> KV <SEP> 50 <SEP> KV
<tb> min <SEP> 60 <SEP> 40
<tb> medium <SEP> 68 <SEP> 48
<tb> Volts / 0.025 <SEP> mm / h <SEP> 483 <SEP> 342
<tb>
 EXAMPLE 43.-
When the polyethylene composition is crosslinked with a peroxide catalyst, the results after mixing as in Example 42 are as follows:

   
 EMI29.4
 
<tb>
<tb> with <SEP> mix <SEP> without <SEP> mix
<tb> of additives <SEP> of additives
<tb> Voltage <SEP> max <SEP> 70 <SEP> KV <SEP> 60 <SEP> KV
<tb> min <SEP> 40 <SEP> 40 <SEP>. <SEP>
<tb> medium <SEP> 62 <SEP> 50
<tb> Volts / 0.025 <SEP> mm / h <SEP> 433 <SEP> 348
<tb>
 EXAMPLE 44. -
The mixtures of Example 42 show excellent sta-
 EMI29.5
 bility to the car with a blinùaee having a: reshti vi tl; of about 100 ohm / cm. comprising a poly (4-ethylene-poly-acrylate) copolymer which comprises 30 to 20 parts by weight of non-oxidising carbon black per 100% by weight of the copolymer when about 1% by weight of the mixture of inductor is used for 130 C0.i.lWC "en) 'If) .td' ie '.'. I., Vi: ee.: B

 

Claims (1)

CLAIMS EMI30.1 ¯fI! "" "" "jA." l.- Solid dielectric composition aayaeterized in that it comprises a solid polyolefin in which is dispersed a voltage stabilizing additive which comprises a EMI30.2 or more clioiiz compounds in the. foy'MC 'jD.l' class non-v hydrocarbon oils,.: i..J.ti: '. 05 1rs rrY.w'i.ji'Rti.mP, .a v4 -.' nk 1-1 Low-point hydrocarbons dl) fm.1 "!. Ol tl'0. . ': a, â ¯'9o a los pol "' phenyles; o. cy ... a.; té.3tw :, les i 4't? ': a) C3 ;; s," r 1 ,, '' ü,?, Cs! , tx:. '35 "s.'C73a: c't': b: substitutes di" 7vrtil:, t un "; '' 'c5: 11s 3.Ccl) ptour i, t::' rià: â and a donor group fi'ôloctroas united poan.t3.e?, ldT: cât 1? in to the other by a transferable proton in a r4voreible way 2-bromonaphtha1ne and 1 "i, riLtonalpRta.î '.' â4 '> e 2.- Composition according to claim 1, characterized in that the additive is a mixture (A) of a very aromatic compound chosen from the class formed by non-volatile hydrocarbon oils and very aromatic hydrocarbons with a low melting point. and (B) a solid hydrocarbon chosen from the class formed by polyhalogenated polyphenyls, substituted aromatic hydrocarbons carrying an electron acceptor group and an electron donor group potentially united to each other by a reversibly transferable proton, EMI30.3 2-bromonaphthxlene and 1-iodonaphtha7.ne. 3. A composition according to claim 2, characterized in that the highly aromatic compound comprises at least 50% and preferably 65% of cyclic aromatic and naphthenic hydrocarbons. 4. A composition according to claim 2 or 3, characterized in that the mixture comprises about 5 to 50 parts by weight and preferably 25 parts by weight of this substituted hydrocarbon per 100 parts by weight of the highly aromatic compound. 5.- Composition according to claim 1, characterized in that the additive is chosen from the drilling class by <Desc / Clms Page number 31> substituted aromatic hydrocarbons bearing an electron acceptor butt and a group, potential united electron donor- ' EMI31.1 le, mont by hydrogen bond by the irztarar, heîiirc: of a proton tiansié1-able tie way rvcr: 3la.L :. 6. A composition according to claim 5, characterized in that the electron donor group and the electron acceptor group are in the ortho position. EMI31.2 7. Composition according to Claim 5, characterized in that the acceptor and electron donor groups are united to aromatic hydrocarbons which are different, but which are dispersed in the vicinity of one another. 8. A composition according to claim 5, 6 or 7, characterized in that the electron acceptor group is a highly unsaturated group. EMI31.3 9.- Composition according to revendleatïon. Or 7, characterized in that the electron acceptor group is a phenyl or polycyclic aromatic group * 10.- Composition according to one or the other back claims 5 to 9, characterized in that that the electron donor group is an amino group or a lower alkyl group of 1 to 8 carbon atoms. II.- Composition according to claim 1, characterized in that the additive is J-torphenyl or a mixture of EMI31.4 o-terphenyl with m-torphenylo and / or p-terphenyl. z.?.- Composition according to claim, characterized in that the additive comprises 2-bronionaphtha.ènq, 1-ioàobiph611yla, ioàipliCny7.auin4, 2 ,, (- din.troani..ne, 2:, 6Ntrinitrotaluno, 2e4-dïnitrOtQlu'ùrlae, 2,6-dinitro-tolubne, 2-nitrodLphenyliiùàJiv, d la 2-d.ntx od.piliny.aminu, o-n1, t1'ounixoloe , de 'on, tral; tlnzy? c of 2'-nitro "anilj.ne, dollantliraxillonitrilo, du, -'. uaro - n3, txobpn.oy (phÙiiyl-alpha-nuà> ti1ylaEmo, phcny .-tta.nap: xtylinn from <Desc / Clms Page number 32> EMI32.1 N1NJ-diphylparaphenylenediamine, diparamethoxydiphenyl-, 4 "iilloo un: ala.'1t; e polychlorinated polyphenyls, diphenylastine or a mixture of these compounds or mixtures of diphenyl-; ..: .. 1n .. ;} with at least one compound chosen from m ... din1troberizene "m-nitroan11ino" p-n1troanil: Lne "m-nitrotoluane, p.li tl'otl,) lun.YI leo-nitroclilorobonzene and p-nitrochlorobensene. 13. A composition according to claim 1, characterized in that the additive has a melting point of less than about 260 C and a boiling point of more than about 149 C. 14.- Composition according to one or the other of the revan- EMI32.2 1.I.'I.nt1on 1) the 6cd (.: Ato: J, characterized in that it comprises approxi- '', .In 4 10 and gr '± 6renco 2 to 5 / l by weight of the additive on 1.ib (1 ;; 0 of the oids of the polyo14iine. 15.- Composition according to either of the preceding resales, j1cations, characterized in that the polyolefin is a low density poly4ttlyléno, a high density polyethylene or polypropylene. 16. Solid dielectric composition, substantially as described above. 17.- Insulated electric conductor for high tonsion current, characterized in that it carries as insulator the composition according to one or the other of claims 1 to 15.