Note: Descriptions are shown in the official language in which they were submitted.
~ WO9~/137~7 PC~/US92/~5]l
` -" 2~00952
FLEXIBI_E FIRE RETARDAHT MULTI-LAYER STRUCTURES
.
S BACKGROUND OF THE INVE~ON
1. Field o~ tho Invention
Tho prcsent invention rolates to improved
~tructures and proce se for making tho same which
compri~o a first structure which comprises a poly(vinyl
chloride), a~d a ~econd structure which comprise~ a
polyamide which e~hibits good fire retardant
propertios. The improvod ~tructure~ find particular
utility a~ electrical insulating ~tructures for
electrical curzont conductor~, namely wire~ and cables.
2. De3cription of the Prior Art
Multi-layer structuro~ typically comprise at leas~
two or mor~ 14~0rs of materials foaturing different
phy3ical pr4portie~, which proportios are optimally
optimi~od in ord~r to ~ati~fy a particular neod at
ha~d. Tho go~l o~ the formation of such structures 1S
to ~rovido ~ ~tructure which is directed to a
particular no~d, and wh-roin the individual layer5 c~
tho 3tructuro~ act to form a compo~ito, and wherc oach
layer of material contribute~ to ~orve tho function ~or
which th~ ~tructuro is do3igned. E~mplo~ of such
~tructur~ are woll known to tho ~rt, and in~lude
compo3ite~ whlch are u~od to form films, whoroin oacn
layer forming tho film may ~oaturo a particular
....
WO 92/137]7 2 1 q U ~ P(~/US92/00511
2 --
proper'cy, -quch as impermeability to a ga~, or a~ a
blocking layer to light or radio energy o~ a particular
wavelength. Another example of ~uch a structure may be
those which would be u~ed to form an insulation
S ~tructure for an electrical conductor, where oach layer
forming a jacket about the conductor might f~ature
improved abra~ion resistance, or improved dielectric
strength, or the like. Other uses of such structures
are notorious and known 'co the art.
The use of ~uch multi-layer ~tructures i3
widespread with electrical conductors. These
conductors typically con~ist o2 a wire conductor ~which
is frequently a metal, including co~per) which is
surrounded by a multi-layer structure. E~amples of
15 such con:3tructions includ~ thoqe taught in U.s. Patents
3,~76,940; 3,860,686; 4,079,191, 4,292,463; 4,327,248;
4,419,538; 4,472,597, 4,510,348; 4,626,619; and
4,691,082. ~horein are di clo~ed a variety of
con~tructions whorein each of the layers may be a
20 polymer, a m2tal, an ela~tomeric material, a fibrous
material, etc., whore each laysr offer~ a particular
advantage, i.e., dielectric ~trength, water
imparmeability, etc.
Two ~avorabl~ materials which may b~ wed in the
25 construction of olectrical conductor3 are poly(vinyl
chloride) (h~reinafter interchangeably referrsd to a~
"PVC") and polyamidos (hereinaftsr interchangoably
roferred to aJ "PA"). Thoso materials are favored as
Sh~ PVC qon~rally forms a good fl~cibl~ insulator,
30 while ~imultaneously, PA generally exhibit good
abrasion ro~istance prope~ties. E~amplc~ of eloctrical
conductors having a multi-layer structure o~ an inner
layer of ~oly(vinyl chlorido) and an outor layor o~ '
polyamido aro taught in Japsno~o P~to~t S914610S,
35 Briti~h Patont 1257810, and Dutch Patont 6917475.
~1hile such multi-layer structurcs comprising a
layer of PVC and PA when u ed as electrical conductors
WO92/13717 2 1 O ~ ~ ~ 2 PCT/US92/00511
- 3 -
are ~een to perform well, such ~tructures also ~uf~er
from oertain undesirable characteristics, One such
characteristic is in the fire retardancy of such multi-
layer structures. In the cas0 whero such are to be
S uqed to form electrical insulation layer~ enrobing an
electrical current conductor, such a~ a wire or
plurality of wires, the requiremont of good fire
retardancy is of paramount importance. As i9 known,
electrical cables presont in a commercial, re~idential
or other structure (i.e., office buildings, homes,
public buildings, and facilities) comprise a plurality
of individual wire~ which are containet within a
jacketing layer, or other plenum. In the evont of a
fire within ~uch a structure, tho hazard of such a fire
lS would be greatly compounded where the insulation layer
enro~ing an el ectrical cur~ont condueting WirB were to
burn or melt off, and thereby expo~e the wire to
contact with an alternate curront path. Sueh a current
path could be the strueture or olement of a 3tructure
within which the wire i~ pre~e~t, or in the more
unde~irable alternative, with a per30n's boty.
Further, melting of an in ulati~g layer of a current
conducting wir~, particularly where pro%imately located
to other currDnt contuetin~ wire~ with similarly
degraded in~ulation layors rai~os tho ri~k o~ contact
betwQen the wire~ and the formation of a short circuit;
~ueh an event raises tho ri~k of ignition of
~ sur~ou~ding materials. Alternatoly, if ~urrounding
; matorials ar~ not ignitod, thero romain~ the risk and
con3equent hazard of the ignition, burning or melting
of th~ materials usod to form insulating layer~ over
tho wire. Bueh matorials froquontly omit harmful
emission~, whieh in sufficiont eoneontration may provo
fatal.
Variou~ ~trueture~ ~roviding good firo rotardant
charaeteristic~ aro known to tho art. For oxample, it
is known to includo variou3 fire retardant additive~ to
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W092tl3717 PCT/US92/~11
2 ~ 2
- 4 -
polyamide compositions to incroase the ~ire retardanc~
thereof; such materials include halogenated organic
materials in conjunction with antimony oxides. While
such additives provide good fire retardancy to the
polyamide, these additives ~rs~uently need be pre~ent
in relatively high concentration~, typically up to 20%
of the halogenated organic material, and up to 5% o~ an
antimony oxide. A further additive known to impart
~ood fire retardant behavior to polyamides i9 rod
phosphorous which is found to be ef f ective in
compositions at concentrations a~ low as 20~ by weight
~owever, both these additivo sy~tems are also known to
suffer drawback~. Both sy3tem3 are known to decreas0
the fle~ural and elongative properties of the polyamide
comprising compositions of which thoy are a
conqtituent. Wher~ a polyamide containing composition
having an ultimate elongation of lO0~ would be
con~idered to be highly de3irable, and be particularly
useful in forming part of a fle~iblo 3tructure well
cuited for in3ulating electrical current conductors,
the u~e of such type~ of a additiveq are al~o known to
subqtantially reduce tho ulti~late elongation and other
fle~ural characteriatic~ o~ polyamide com~ositions of
which thoy compri~e a part. A,dditionally, r~d
2~ pho3phorou~ is known to impart a deep color to
polyamido compo3itionJ which is alao frequontly
- undesirable.
It ~hould bo apparent that there remains a
continuin~ nood in tho art ~or multi layer structures
featuring goot fle~ural characteristics and goot firs
retardant propertioa, aa woll a~ mothods for making the
same. Such multi layor ~tructures would be
;particularly u~oful in ~orming insulation structures
for electrical curront conductors.
5UMMARY
, i
WO92/13717 PCT/U592/~51l
21~09~
The pre~ent invention provides a multi-layer
structure which exhibit good ~ire retardant behavior,
good flexural propexties and which ~inds particular
utility as multi-layer structures for electrical
current conductors, and in optical waveguides.
~ he present in~ention alsq provides improved
methods o~ producing multi-layer structures which
e~hibit good fire retardant behavior and good flexural
propertie3.
The multi-layer 3tructure~ of the in tant
invention include3 a fir~t layer ~ormed from a
eomposition which comprises a plasticized PVC and which
may optionally include further additive~, and a second
layer formed from a compo~ition which compri~e~ a
polyamide, and up to 20~ bg weight of a phosphonate
ester, and optionally includes further constituents as
additives.
The present invention also provides an improved
method of forming a fl~ible, fire rotarda~t structure
having two layer~.
In a further a~poct of the inv~ntion, thers i~
provld~d an improv~d mothod o~ producing a flexibl~
insulating structuro enrobing an eloctrical current
conductor, or an optical waveguido, which ~lexible
in~ulatinq ~tructur~ feature~ good fir2 retardant
properti~.
~ n a still further asp~ct of tha present
invontion, there i9 provited an in~ulat~d electrical
current conductor, wherein the insulati~g structure of
the ~aid conductor compri~es two layers of
thermopla3tic matorials which include~ a first layer
~ ; formed from a composition which compri3e~ a plasticized
: PVC and which may optionally includo ~urthor additives
and a second layer formed ~rom a comya~ition which
compri~es a polyamide, and up to 0~ by weight of a
pho~phonate oster, and optionally includes further
constituents a~ additi~e~.
4 --- ~J: 3 ~ 7 l , _ ~ ;7 _o ~ J ~3' J ~: 3~ J'~
,.
..~,.:"
- 2~ 0 0 9.~2 . 6 -
Oth~r ad~rantages and eature~ o the pr~ser
rentlo~ wlll beco~e a~pazen~ ~zom the ~ollow~n~
de~c~lp~l~n, a~tached d~awl~g~, and a~e~e~l clalm~.
Pi~ end per~pec~lYe view 4~ o~e a~peci; o~
the inven~io~, ~howlng a multl-layer ~tructure where~n
- . the ~IC and ~A layer~ a~e o~ a geI~er~lly planar Po~n.
~` Flg. 2 i~3 an esld p~xspec~ive vlew o~ a ~ur~hex
:~. 10 a~3pe~c~ o~ ~h~ a~t l~v~n~ion and ~howa a pe~pectlve
:~ ~riew o~ a rnultl-layer ~tructur~ 1~ acco~nce wl~h ~he
~ p~ewent ln~ntion.
Flg. 3 1~ a ~uxthe:r e~odlmQn~c of the p~e~ent
,~1 inv~tlo~ illu~t~a~e3 an e~?loded per~pectl~e vi~w
15 of a~ electrlcal conductor utillzln4 ~he multl-layer
~ruc~ure o~ the pre~ent in~en~lon,
~ g. 4 i~ a ~chema~lc. repre~entatlon o an
$~du~rial proce~ r pro~uclng a mulcl-layer
struct~re of the i~vent$o~ by coextru~lo~ technlque~.
., . 2~ ~lg, 5 1~ a ~u~ther ~che~atlc repre~n~a~$o~ o~ an
n~s~rlal proce~ Sor producl~g a mult~-layer
stnuc~ure c2 ths ~nver,tio~L by tan~em ex~ru~ion
t~ch~qu~
: 2~ ~9~5~}~
cco~dlns to khe in~e~tion, a mul~l-laye~
; ~tru~re exhloltln~ goo~ ~ixe retarda~t behavle~ and
., good 1~xural pro~rtle3 and ~hlch S~nd~ particular
~t~ y ae mul~l^layer ~txuc~ure~ ~or electrical
30 d~srlce ~ ro~rided. rhe ~rulti-layer ~3tmctur~
cozrq?rl~e~ cwo lay~r~ o thormo~la~tlc matQrlal~ which
clu~e a ~ t layer ~o~e~l ~rom a co~osition whlch
'!,'.~,i, C4m}~3';L~ a p:La~tlc~z~ ~VC arld w}llch may op~o~ally
l~cl11de ~u~thl~r additlv~e, and a ~ecq2~ ye~ ~ormed
35 ~om a co~?oa~t~o~ whlch co~rl~e~ a poly7~nlae, a~ up
to 0% b~ w~igh~ o~ e~ pho~?ho~ate e~ter, and optlonally
i~clu~e~ he~ con~ ue2lt~ a~ additl~e~.
SU~3ST17'1JTE SHEET
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` W092/13717 2 1 0 0 3 ~ 2 P~T/US~2/~711
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~s has been noted above, a first layer consist3 o~
a composition compri~ing PVC, a plasticizer for PVC and
optionally further conventional constituent~ which may
be desirably included in the composition.
The PVC to be incorporatod may bo any yrade of PVC
desired which i~ formable into the ~tructuro~ taught in
the instant invention, and as ~uch allows for
considerable flçxibility in the specification of the
PVC. The PVC may exhibit any de~ired physical
properties, ~uch as 9pecific molecular weight or weight
ran~e, temperature duty rating, colorants, and may
further include quantitie3 of additive~ commonly used
in the art, in amountq which aro not found to be
detrimental to the flexibility or fire retardant
behavior o~ the multi-layer ~tructure.
An additive which is incorporated in the PVC
containing compo3ition which Eorm~ the first layer is a
plasticizer. As is kno~n to th~ art, the plasticizer
act3 to reduce the vi~c03ity of the Pvc during the
production proce3~, and the~e]by improYe its
proceqsability. The amount of pla~ticizer which may be
u~ed is any amount which provides desirable
processabLlity for tho formation of the structure of
the presont invention. By way of non-limiting example,
in tho production of insulat~d oloctrical wirc~,
loadin~ of botwe~n appro~imat~ly lO~ to 50% by wcight
o~ pla~ticiz~r into tho PVC aro used, although higher
a~d low~r amount~ may be u30d. E~ampl~s of usoful
pla3ticizers includo phthalato ~la~ticizors, and
pr~forably arc one or more from the group consisting o~
di-2-ethylho~yl phthalat~ tDoP)~ diisodocyl phthalate
(DIDP), diundocyl phthalate (DUP), and ditridecyl
phthalato (DTDP). Equally proforrod aro trimcllitate
~la3ticizor~, os~ecially trioctyltrimollitatc ~TOTM)
and trilsooctyltrlmollltat0 (TIOTM). Tho~o pro~orred
trimollitate and ~hthalato plastlcizorl aro
co~norcially avallable
:
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W092/13717 PC~/~S92/~511
~ ~ O U 9 ~ ~ - 8 -
One optional additive to the PVC compri~ing
composition which form~ the above notod first layer o~
the multi-layer ~tructure includes pigments or other
coloring agents which may be blended or otherwise
incorporated into the PVC layor; ~uch colorant3 are
useful in wire "coding" or othor idQntiication and/or
marking systemq. Other additive~ may be also incluted
in the composition. One such class of additive are
adhesion promoters for enhancing the adhesivity between
the layer of such a multi layer structure. Further
constituents such a3 lead stabilizer3, tin stabilizer~,
inorganic ~illers such a~ clay3, calcium carbonates,
talc, wollastonite, or silica a3 well a3 various typeq
of lubricants and wa~es which are known and in common
15 use in the art may al~o be introduced a~ additives into
the compo3ition according to the invention. Further
additives include those which are broadly referred to
as "synergists" usoful ~or their fire retardant
propertie3. One non-limiting examplo of such a
synergist is antimony 02ide, but other compo~itions
including zinc borate and iron oxido, as well as other
composition~ which behave a~ ~ynergists may al30 be
incorporated into compositions in accordin~ with the
inventors' teachings.
rhe PVC, plasticizer and any furthor optional
con~tituents us~d to form tho composition of the first
layer o~ the multi-layer structure may bo combined in r~
a~y manner capable o~ thoroughly distributing the
m~torials within onc another. Methods which aro
reco~nizod as suitablo ~or uso includo physical mixing
such as tho physical mi%ing attainod via the use of a
tumbling vessol, and by molt oxtrusion. Preferably,
ths constitu~t3 are melt extrud~d whorein mcasured
amounts o~ the PVC, plasticizor and any further
constltuents are ~hy3ically mixed and ~ub~equently
introduced to a 3ingle ~crew cxtruder, twin-~crow
extruder, or plastlficator, heatot to a temperature
.
. .
. .
W~92/137~7 PCT/US~2/~511
2 f 003~2
g .
above the softenins point of at least one of the
constituents and ~ubsequently extruding the
constituents through a die to form strand3 which are
then pelletized The resulting pellets compri~ing the
PVC, plasticizer and any optional constitusnts which
are ultimately used to form tho fir~t layer may be u3ed
:as feedstock for the further extrusion operation~ in
accordance with the present invention.
Polyamides suitable for use in conjunction with
~10 the instant invention include well-known polyamide3
;which are long chained polymeric structure~ having
recurring amide groups as part of thelr polymer
backbone. Prefsrably, thc polyamides have a relative
viscosity of from about 40 to about 250 measured in 90%
1~ formic acld at a concentration of 9.2 weight percent.
Ron-limiting e~amples of 3uch polyamides are:
:(a~ those prepar~d by the polymerization of
lactams, and preferably epsilon-~aprolactam (nylon 6);
(b) those prepared by the condensation of a
diamine with a dibasic acit, and pre~erably the
condensation of hexamethylenc diamine with adipic acid
(nylon 5,6); the conde~sation of he~amethylene diamine
.with ~ebacic acid (nylon 6,10), th~ condensation of
tetramethyl~nediamino with adi?ic acid (nylon 4,6), and
the condon~ation of ho~amethyl~ono diamino with azelaic
acid (nylon 6,9),
(c) tho30 ~repared by ~elf-condensation of amino
acids, and ~r~forably self-condensation o
ll-aminound0canoic acid (nylon 11) and
solf-oondensation of 12-aminododecanoic acid (nylon
12); and
(d) those based on polymorized vegetable oil
. acid~, or random, block, or gra~t lntorpolymers
consisting o~ two or moro o these polyamides, or
polyamide blend~.
Preferred polyamides are polyep~iloncaprolactam
~nylon 6), polyhexamethylene adipamldo (nylon 6,6), and
, . ~
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WO 92/13717 PCr/US92/00511
~lQ0~5~ - 10 ~
a copolymer o~ polyep3iloncaprolactam and
polyhexamethylene adipamide (nylon 6,6/6). The most
preferred polyamide i5 polyep~iloncaprolactam.
Amorphous polyamide~ such as thoss prepared with a
diacid and meta-or para-xylene dLamine,
4,4'-methylenedianiline, 1,3-or 1,4-phenylenediamine,
or 2,4- or 2,6- diaminotoluene are also useful.
The aforementioned polyamides containing variou~
terminal functionalities are also suitable for use in
the present invention. The3e include the preferred
polyamides which compri 9 0 pO lycaprolactams (nylon 6)
which includ2 (a) a carbo~ylic yroup attached to one
: end and an acetamid0 group attached to the other end of
the polymer chain, (b) an amino group attached to both
end~ of the polymer chain, (c) a carbo~yl group
. attached to one end and an amino group attached to the
~ other end of the polymer chain, and (d) a carboxyl
group attached to both ends of the polymer c~ain. Of
these, most preferred are tho~e categorized a~ (c)
20 above, and include a polycaprolactam having a carboxyl
group attached to one end and an amino group attached
to the other end of the polymer chain.
In accordance with the pre~ont invontion's
teaching, tho ~ocond lay~r furthor includes a
25 pho~phonato estor wherein the phosphonate ester is
incorporatod in amount~ of up to 20~ by weight of the
` - polyamid~ compri3in'q~composition u~ed to form the
socond layor. Suitable phos~honate esters are those
- which may be characterized as havin~ the chemical
30 structure:
C~2CH3 . t
(CH30)x~ (OCNl~ ~CH3)2_~
C~3 C~2
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~092/137~7 2 1 0 0 9 5 2 PC~/US~2/~511
wherein the value of "x" may be O or 1. Such a
matorial features excellent thermal stability, low
volatility and is roadily processable. Preferably, the
phosphonate e~ters according to the invention arc a
blend of phosphonate eqters, as repre3entod above with
a preponderance of phosphonate esters wherein the value
of "x" is 0, and with a lesser amount of pho phonate
esters wherein the value of the substituent "x" i5 "1~.
~uch a phosphonate e~ter is commercially available a2 a
viscouq, straw-colored li~uid and i9 g0nerally
describod in the "Product Information Bulletin -
'Antiblalze'O 19 Flamo Retardant and 'Antiblaze'~ l9T
Flame Retardant", copyright 1987, from Albright and
Wilson, Inc. of Richmond, VA. The3e pho~phonate esters
are di~cussed a~ well in U.5. Patents 3,789,091 and
3,849,368 as3igned to Mobil Oil Corp, the dcscription
of which are horein incorporat~t by reference.
In accordance with thc pre~nt invention's
teaching, th~ phoqphonate e3t~r may be pre~ent in any
amount to comprise up to about 20% by weight of the
compo~ition used to form the s,econd layer, with the
~ole proviso that an improvomont in tho iiro retardancy
o~ the polyamid~ containlng la~y~r of a structuro be
realiæed. It should b~ apparont to ono s~illod in the
art that tho preci~e amount of phosphonate o~tor to be
incorporatod in a compoqition U10 to form a structure
fo~turinq tha bene~it~of tho prcsont invention's
to~ching i9 bo~t dotorminod and optimi~ed through
e~p~rimontal m~thods. Prefo.rably, tho welght
percentage of the phosphonato ostor in tho PA
comprising compo~ition is wlthin tho rango to comprise
bot~o~n about 0.001~ and 20%, more profora~ly fall 9
within th~ rango o~ betwoen about 0.013 and 20~, and
most preferably i~ within the rango of botwoon about
3S 0.01~ and 8.8~.
The polyamido layo~ may optionally include various
amount3 sf additivcs which are of common usage in the
W092/13717 PCT/USg2/~511
~10~952 - - 12 -
art. Examples of such additiv*~ include pigme~ts,
dyes, heat stabilizer~, lubricants, plastici~er~
including caprolactam, UV absorbers and stabili~ers,
By way of example, repre~entative ultraviolet
light absorbers and light ~tabilizers include variou3
substituted resorcinols, salicylates, benzotriazole,~
benzophenone~, and the like.
Suitable exemplary lubricants and mold release
agents include stearic acid, stearyl alcohol,
- 10 stearamides, sodium stearate and zinc stearate.
By way of example, suitable coloring agents
- including dyes and pigments include cadmium sulfide,
cadmium selenide, titanium dioxide, phthalocyanines,
ultramarine blue, carbon black and the like.
Representative oxidativs and thermal stabilizers
include the Periodic Table of Element's Group I metal
halide~, such a~ sodium halides, potas3ium halide3,
lithium halides; as well a~ cuprous halides, and
further, chloride3, bromides, iodide3. Al30, hindered
phenol~, hydroquinone~, aromatic amines as well as
substituted members of those above mentioned groups and
combination~ thereof.
In a manner ~imilar to thlat diacu3sed above in
conjunction with th~ PVC com~rising composition, the
-25 PA, phosphonate e~tsr and further optional constituent3
- u~Qd to form the composition of the second layer of the
multi-lay~r ~tructure may be combined in any manner
ca~abl~ of thoroughly distributing the materials within
on~ anothar. Methods which are recognizod as ~uitable
for use include physical mixing such as the phy~ical
mixin~ attained via the u~e of a tumbling v~s~el, and
by melt ~xtrusion. Preferably, the conYtituents are
melt extruded wheroin moasuret amounts of tho PA,
pho~phonat~ ester and any ~urthor con~tituents are
phy~ically ...ixed and ~ubaoquently introduc~d to a
single ~crew oxtruder, twin-3crew extruder, or
plastificator, heated to a temporature above the
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WO92/13717 2 ~ O 0 9 ~ 2 PCT/US92/~511
- 13 -
soEtening point of at least one of the con3tituent3 and
.subsequently extruding the constituent3 through a die
to form strands which are then pelletized. The
re.sulting pellets which consist of the composition
; 5 which are to be ultimately used to form the second
layer may be uqed a3 feedstoc~ or the fucther
extrusion operations in accordance with the pcesent
invention.
~oth layers, i.e. the first layer comprising the
plastici2ed PVc and the second layer compri~ing the PA
and the phospho~ate ester may be in the ~orm of a ~ilm
or sheet obtained by separate extrusion proce~ses, or
alternately may be co-e~trudo~. Similarly, if the PVC
comprising layer and the P~ compriqing layer are o~ a
different iorm, the form may be either separately,
se~uentially or co-e~trudcd. Although dependent upon
the particular intended applicatio~, typically the PVC
-~~~~~~ comprising layer ha~ a thickne3s of abou~ 0.25 to about
2,30 mm, (about 0.010 to about 0.090 inches), and
typically, the PA comprising layer may have a thickne
o~ about 0.05 to about 0.40 mm (about 0.~02 to about
0.016 inche~). It is to be understood that th~se
thickns~se~ a~e ~or the purpo~e of illustration, and
are not to be considered limlting the applicability Oc
the toaching~ of tho pro3ent invention.
The multi-layor structure according to the instant
invention can ~e uaed in any applicaticn where a
multi-layer structure is roquired. In general, the
multi-layer structure is u3eful as an inaulation and
protoctivo jacket. More specifically, ~he multi-layec
structure in tubular form find~ particular use in
,. ~
enrobing an electrical current conductor, i.e. a metal
or m~talli¢ wire which consist~ oi a single strand or a
plurality o~ ~trands, and in the altc~nativo in
enrobing o~tical fiber~. It ia to be undorstood tha~
the term "enrobing" a~ uaed in thi 3p~cification is to
be underqtooc1 as wrapping, jac~eting or enca~ing the
,
" ' ~ ' ' ' ' '
,
.
: RC\'. ~ E~lA~ c!lF-~ 0,1. ~ ,, ~_ 4,, ,~3 _ . ~ ") 1 ,~r~ J ~ CJ~ f~"~
circum~e~e~ce ~in the casf.~ of w~re~ ng a generally
circular ros~-~ectlo~ or ex~erlo2: (in ca~e~ o w~r~
whlch do no~ hav~ a ger~e~ally Ci;~cu~ Lr CrO~ 0eCki4n)
`~'~ of a wlre or alt~rnate~y, o~tic~l waY~gulf~ The ;Cl~m
reta~ cy o~ the co~a~ orl~ ~or~ g ~h~ P~
~, co~aprl~l~s lay~r of thf~ mul~ re~ ~trua~ur~ taugh~
herein are e~luat~d 1~ accor~ance ~ith the ~ hed
protocol o ~he U~erwrl~ex ' ~ ~aboratorie~ 94 ~e~
~or tha PlaD~ab~l~ y o~ Pla~tic b~te~lale, partlculaxly
the "V~rtlcal Bu~ni~ T~3f3t ~OX Cla~ ying ~erlalM
~4~ 0, 9~ 1, g~-v~al which 1~ ~ully de~crlbed ~n ~he
~ubllcat~ orl ~ta~d~r~ ~or Saf~y ~ t~ ~or
~, Flar~ab~ y o~ Pla~tic ma~e2lal~ ~or Pax~ ln ~evlces
" ~- and ~ppllancesl', cbp~righted 1973, lg88 and a~ re~lsed
~5arch 19, 19gO a~ payee 7-10, the complete co~e~ o~
~hlch arf3 herein lncorporated :by re~erence, In brief
~u~ry the T~-34 Y~r~.lcal ~ur~i~s ~e~ UY~d ~o
: . evalua~ the per~o~manc:e o~ bar ~peci~e~ when
. c~ntacted s~ h a ~lame. 8ample bars o~ each ~peclmen
q ~ 20 *re i~t co~altloned in a~ alr circulatl~ o~en, a~
hen e~ch o~ 1ve bar~ of ~ach o~ th2 aample speci~n~
to be e~raluate~ are ~uppo~ted at one el~d ~o to ext~
t~cally ~rcm the, ~u~?~o~. A layer o~ dzy ab~orb~nt
c~ on 1~ placed ~0.5 cm tl~ in) belo~ the bar, as~l
-~: 25 ~che the 1a~ pplieO. ror a ton (10~ ~cond
te~val A~ t~ cen~er o thQ bar, Th~ Slam~
~. wi~h~xawn an4 ~or t~e Hub~eguent thl~y (~0) ~econt~
-~ rhe bar i~ ually o~se~ved to note the ~U~ation of
la~ing an~/or ~lowl~g. I~ it 1~ dl.~CUlt to
~i~tl~gui0h betw~0~ g o~ glowing, ~he cotton i~
b~4u~ht up into Co~taCt wi~ the ba:~: and i~ l~nitlon
occu~, the co~dition o~ the bar ~u con~l~er~d a~
ml~. 'rh~ teo~ 1~ r~ed a~ai~ on the ~ an!ple
- ~ar ~oz ea¢h ~a~le ~ar ~o agai~ ~etex~e the
a~ab~1~ty characte~i~tlc~ ther~o~. Co~dltlo~ to be
ol:~re~ a~d r~cordQd lnclu~o: la'~ ~urat~o~ o~ g
a~t~ he 1~t ~ a~llcation, ~b) du~at~on o~
SUBSTITUTE S~E~T
... .
RC~ EP.~ E.~ o ~ J:3 ~ r;r, "~ J fJ~ 3~ ;r, ~ f,
-~ 2laoss2
- 15 -
~lam~ng ate~ thQ ~econd 1am~ appl~catlon, ~c)
durat~on o~ 1a~ing pl~ ~lowl~g a~tex th~ ~con~ 1~me
appllcatlon, (d) whether ox no~ ~eclmen~ are con~umQd
d, a~d burn to the hoL~i~g clamp, and (e) whe~e~ a~ not
s the specimen drips ~lamlng particle3 which i~ni~e the
cotton ~atch.
. ~pecim2n~ evaluated ~n accordance with che abcYe
: U~ ~4 pr~ocol are a~g~e~ o~ o~ three cl~es,
. Cla63 ~ v~o~ de~ated for ~ampl~ wh~ch do
:~ 10 no~ bur~ wlth a fla~l~s ccmbustlo~ ~o~ m~e than t~n
: (107 ~econd~ ater elther the ~ir~t or cecond
appllcatlon o~ ~he te~t ~la~e, ~o not have a ~otal
:. ~~, fla~lng c~bu~tion t~me xceedi~g 50 seco~ds ~or the
t~ 10 ~lame appllca~lor~ for each ~et o~ ~ltre
~cime~ re no~ cG~.ed to the holding ~ xture, do
no~ h~ve a~y ~pecl~nen0 which d~ip ~laming par~lcle~
~hlch ~g~i~e the dry ~urglcal cot~o~ plac~ 30.5 cm ~12
in) below t~e ~e~ted ~ample, and do not ha~8 a~y
~pecirne~ with a glowi~g cozr~w~torl which per~t~ for
. ~ 20 mox~ tha~ thi~ty ~30) ~eco~d~ a~ter the remoYal o~ the
cond ~lame.
Cla~0 n94-V-l" ~ d6l~1gnated ~or ~ le~ which do
no~ ~rn wlth a ~ ming combu~tlo~ ~o~ mo~z tha~ ~h~ty
: ~30~ ~oconds a~er el~her appllcatio~ o~ the te~t
' 25 ~la~ 0 ~ot have a total 1am1n~ co0bu~tion ti~e
exceedl~g 250 ~eco~d~ ~o~ te~ (lo) flame ap~llcatlon
~ox ~ach ~t o~ ~1VQ ~eclmen~, are ~ot con~ume~ to the
: holdlng ~lxt~rs, ~o no hav~ aLy ~pec~m~n~ which d~ip
~lamlns partlcle~ whlch i~te th~ ~ry surgical cotton
- 30 place~ 30.5 ~m (~2 i~) below thQ te~t~d ~a~ple, and do
n~t haYH any ~ecimen~ wlth a slow~ng co~bwtlan whlch
p~r~ o~ mw~u tha~ ~lxty (~0) oaco~d~ a~t~ th~
re~ova~ o~ the ~econd tlam4.
- Cla3a ~4-v~2" 1~ deslgDlt~ ~or ~ample~ wh~ch do
~o~ bur~ a ~la~lng combu~lon for ~or~ than th~rty
~30) ~oco~d~ ata~ elther th~ rlra~ or ~e~ond
a~llcat~oa o~ t~e tH~ ~lame, do n4t haY~ a ~otal
SUE~;Tl~lJTE S~ET
,,' ,
RC~ ;, E~'A~ ;C~ 0 ~ ,*~ a ~ : .rjt; : '~ f~ ~o~J ~ 4~:~ 8~ ~:J':JÇ~
. __ . __ _ . _, . _ _. ._ __, . . , _ ~,.. _ ,_~.,_.,~,--. ,.__ , , ~,
- 15 -
1amlng combu3~1On ~lme exceedln~ 250 ~econd~ ~or t~,e
t~n 10 ~ a~ lca~ion ~or ~ach ~3Qt of~ ~lve
epacl~e~, are not con~urrlQd tc: tha holdin~ ~ixtu~e, rnay
ha~re on~ o~ e ~pecimen~ which ~p ~ ng ~ar~icLe~
5 wh~ch ignlte ~he dry ~urglcal cokto~ ~la~ed ~0~5 cm (12
n~ ~elow ~h~ te~ed ~p~clmen, and do not haY~ a~y
~peci~ens wlth a glowing combu~tlo~ which per~l~t~ ~or
more ~hi~ elxty ~60) ~econd~ ate~ th~ ~e~al of the
~ecun~!l ~lame.
~u~the~ only o~e ~peci~en o~ ~h~ re ~ample
~pec~n0n~ o~ a ca~poa n doe~ not coa~ly wlth
reqlllrement~, a secorld ~t o~ ~itre ~pecl~en~ o the
~am~ corltpo~ltion are to be te~ted. All ~3pQCimen8 ~rom
thi~3 ~econd ~e mllch comply ~$~h ap;propriate
lS re~uix~ments in o_der to he material ~o be p~operly
ca~egorlze~ a~ 94-V-1, 94-'V-2 or 94-V-3.
While ~ct part of the UI- I,a~3orator~:e~ protocol,
~he l~e~o~'~ a3~1yn a ratl~ of "~B'' for materlal~;
whlch ahow~d ~lan~aJ~llity o ~h~ specimena whlch
e~ceeded th~ 94-V-l, s~-v-;2 or 94~ rati~g~.
An alte~nat~ve teet wh~ch ~8 ~seul $n deter~inlng
~he ~lunmab~llty char~cteri3tic~ o an enrobed wi~e 1
de~gna~ed as UD~le~er'~ ~abC~r;3tO~ieB'19 U~ 1581
zo~t~1-8pecl~e~ Flame ~t ~ox ~e~plastlc and
Ru~ber In~ a~ed ~qires a~d CabLe~ lch 1~ fully
d~cri~ed in ~ ere~ce 9~aa~dar~ ~or ~lectrlcal Wires,
lexlble Cord0", ~c) Unde~rltex~
~a~o~a~orle~, pag~0 100-102, dat~ Au~u~t 15, 19~3.
~rle~ly, ~hs tec~ re~uire~ thac camp~ le~gths o~ a
fln~he4, al~le contluc~or the~moplastic ~n~ula~ed wlre
5~ O:~ cable b~ ~uppo~ted in a hoz~izon~al po~it~o~, and a~
a ~oln~ nl~ che~ da~eath the ~ample, a
' ~o~lzunt~ lay~r o~ dry ~urglcal cot~on be
placed. ~ guently, a ga~ Yla~ i8 contacted tO the
35 ~n0ul~tq~ Wix~e m~pol~t fo~ a ~erlod o~ 30 ~eco~do,
a~e~ whlah the ~1a~ 10 ~red awa~. ~e duratlon o~
th~ g ar the l~ulatio~ lay~r~ le not2d, a3 ~ell
SUE~STI~UT S~I~ET
,, ,
RC~. ~ 0~ PA ,~ C~ -.;) 3 ~ 7 .~ S1 ~S) ~ )f~ "~
.;. ~
;: 21009~2
- 17 -
a~ the prog~ io~ of the ~laming or oth~ deg~aoa~lon
o~ the ~ire'~ ln~ulatlon. ~ot~ 1~ al~o taken w~ether
ary par~les or d~op~ ar~ ~mltted, ~nd wh~thQr ~uch
' ignlte the cotton.
~ 5 ~ ~urther test ~o deten~l~e the ~lam~abillty o~
`~ i stru~ure~ wa~ ala~ perfonm~d. The ~l~,it~ng Oxygen
Index,. ~LOI) wa~ determlne~ ~o e~tabllsh the mlnlmu~
conc~ntratio~ o~ oxygen needed to malntal~ a candle~
l~ke co~u~io~ o~ a ~ample ~trwtu~. 2~ thls te~, a
~e~t ~pQCime~ i~ plac~ ~er~lcally in a gla~s~ cyll~er,
~ ignite~, and a ga~ ~trea~ o~ a mlxtu~e o~ oxygen and
,~ . ~i~rag~3n are upwardly fllrected through the gla~
. . cyl~de~ 30 ~0 pa~ pa~t Yertlcally orle~te~ wlxe
ample. A~ i~lt~al oxy~e~ concentratlon 13 selected,
-; . 15 ~he apt~e~men lg~l~ed ~ro~ the ~Dp, antl the length o~
bu~lng a~d the tlme are ~loted. Su~egu~n~ly, the
eon~entratlon of oxygen i~ the stream 13 ~crea~d o
alter~Qt~ly dscre~ed, ancl the ~a~e ~pecl~en i9
e~g~lte~ or altexnately, a ~ew ~peci~n ia pro~ided in
-.-.L, 20 l~ke ma~er to th~ gla3~ cylin~r a~d lgnLt~d. Thi~
~e~t ~ rep~a~e~ u~til th~ lo~e~ co~centra~lon o
~~ oxygQn ~eedetq to ~uppor~ a ~teady, candle~ e
~ ce~bu~tion oZ a ~pecime~ 10 m~lr.~alned. m e Yalue
-~ ~o~rm~ne~ 1~ a ~um~rical ~alue wh~ch eg~al~ the
p~rce~ as~ c~ oxy~en gas 1~ the oxygen/n~trogen ga3
` et~eam u~e~ durln~ thQ t~st; h~her p~rce~ta~e~ of
~xy~e~ ~dlcate ~e~i~ta~ce to fiammablllty o~ a ~am~le,
~: a~d co~ver~ly, lower ps~centages o~ oxy~n l~dlcat~
. mo~ ~0a~y ~a~m2billty o~ a test ~ample.
.~ 30 ~Yaluat~o~ o~ ~he phynlcal ~ropertl~ the
c~m~oJltlona ~oxxln~7 ~it~Q2 o th~ 0a~1s~ w~r~
:-- per~or~e~ o~ ~olde~ tee~ baz~ undez th~ ~ollowing
. ~rotoqal0: tlo~c~d and U~n~tched ~za~ Impact, A~IM D-
a~6 tR~ le~uraL ~ro~ztl~0, A~S D-7~0 t~at, ~enslle
3S ~t-~ength an~ Pro~ertla~, ~ D-638. ~he prot~col~ for
~:h43f~Q ~ro~ert~ are welL lsn~w~ to tho~ cllled 13 the
~rt .
, .
:: , SlliB$~1TUTE~ S~ET
,
.:. ,
: ' ,
~ ? i
:. KC~PA lI. i~,CHE~ 3 : ~ I: f~ f;8 ~ ~ +~3 ~ fJ8 ~
-~-` 21009~2
- ~B
Furt~er ~o the~e above noted te~t, ~longatlon o~ a
PA com~ri~l~g laye~ ln t:~l2 multi~.ay~r ~t~ctur~ a0
taught by ~he lnven~o~s wa~ evaluat~d ~19 ~ollow~: ~zom
a two layer ~t~uctur~ whlch ha~ bee~ ~xt~ onta a
wlr~, ~he PA corn~r~ing layer wh~ch contai~ the
pho~phorl te ester wa~ separate~ from the PYC compxlsing
lay~r~ rhe PA co~ri~i~g layer wi~s ~he~ cut l~to a
0.3175 csr~ ) wlde ~trl~ u~ln~ a 1~ ~nch 41e
~uttlar, anâ a~t~rwaxd3 ~hQ lnitial ~lo~gat~orl wa~
te~te~ in accor~a~Lce wlCh A9TbI 15~1 t~ot~ng ~rotocol to
~e~e~e lnltial elo~gat~on o the Gaid layer.
lng ~ow to the drawlng~, dep~cte~ oz:~ Fig.l 13
d perspectlve ~lew o~ a multl-layer ~t~uctur~
w~r~in ~he P~C ar~ PA layer~ are ~hown So be of a
ge~e~ally pla~ar ~o~ uch a multi-layer ~ruc~ure 1
m~an~ to ~Ppre~t ~oth ~all ar~icle3, such a3 pla~ues
and~o~ plates which are r~g~d ~ t~ucturally ~eL~
~; ~up3;~0rtlng, a~ well a~ larger artlcles ~uch as a ~
o~ ~heet, E~ther, i iFI t:o be un~r~tcod that ~uch a
m~lt~-Lay~ ~tn~ct~lre bel~g shown may b~ rspre~eutative
.~ Or a ~lm ox coating ~truc:ture ~ulta~a to be uned ln
cor~tmct~o~ w~th a ~ur~h~r. ~txUctUr~ not ~how~. A~
- ~p~cte~, the s~ruc~uro 10 comE~xlse~ ~wo layer~, a~lr0t layar 12 c~ri~i~g a pla~ciz~d P~C and a
. ~ 25 8ecolld layer 14 o~ PA co~cal~l~g compo~ltlo~ Whlchinclud~ a phos~?honate e~t~r a~ ~urth~r optlonal
constl~llent~. 8uch a 0t2~uctur~ tlo~lly lnclude
a~ ad~ ,re material~ ~nt~edla~e the ~lrD~ layar 12
a~ t~ oeco~ layer 14.
3~ ~lg, ~ ia ~ en~ per~p~ct~e vi~st o~ a ~uxther
t2:uctu~ 20 accor~l~g to the ~n~ant lmre~tion ~ntl
. - ~hol4c a ~70xc~Pactl.vo vlew o~ a n~lti-layer ~tructux~ ln
s,cco~danc~ ulth th~ ~re~ont l~ve~lo~ c~cructurQ
- 20 corh~ e~ la ~ t coz~e-ty~ layer ~2 whlch, ln
c~nt;ra~t So the o~uc~ur~ 10 acco~dl~g to ~lg.l 1~ ~Qen
to b~ gene~ally non~pla~ar but ~yllnd~ical ln ~o~.
'rho ~zuctu20 20 ~urthor l~clud~ a céc~ l~ye~ 24
,
~ SlJB~;TlTllTESHEE~T
W092/13717 2 1 0 0 9 ~ 2 Pcr/us92/oo5l,
- 19 --
which comprises a P~ layer, and is layered in regi~ter
with the first layer 22. While not particularly
illu3trated, it is contemplated that a further
structure or material which providas good adhesion
between the composition~ compri~ing the ~irst layer and
the second layer and located intermediate to the fir~t
layer 22 and the second layer 24 may be included.
Fig. 3 portrays a ~urther embodiment of the
present invention, and illustrateq an exploded
perspective view of an electrical conductor 30
utili~ing the multi-layor structure of the present
invention. The electrical conductor 30 comprises a
wire conductor 32 which may be ~ormed ~rom any ~ultable
metal including copper, aluminum, copper-coated tin,
silver-plated copper, and stainloss steel. The wire
conductor 32 may be of any suitable size, including but
not limited to those between 1,000,000 CM ("circular
mil") to about 22 AWG ("Americ~n Wire Gauge":), although
it is contemplated that other wir~ conductors not
within this particular preferre~d range may also enjoy
; the benefits of the present inve~tion. Further, the
wire conductor 32 may be a sin51le ~olid metal conductor
such a3 a m~tal strand or a plurality of metallic
conductors which may bo twistecl metallic conductor~.
Th~ fir~t layer 34 (or "inner layer") conta~ting
the ~lectrical conductor 20 i3 comprisos the
plasticized PVC and othor additives in accordance with
tho ~oachin~ o~ the i~tant invention. This ~irst
layer may bo ~ormod about the electrlcal conductor 20
by any suitabl~ moan~. An oxtrusion process would be
proferred. The thicknesq o~ tho first layor 34 may be
any dosirable thickno~s and ls not con~equontial to the
practice o~ the proJent invontion. Howover,
thickno~30s whlch are in common w e are preforably
employed. The seco~d layer 36 (or "outer layer")
~omprises the PA and phosphonat~ ester, as well a~
optional additives, may bo ~orm~d about the ~irst laye~
WO92/13717 PCT/US~2/~511
2100~52 - 20 -
32 by any suitable means, with an extru~ion prooss~
being preferred. Similarly, the thickne~s of the
second layer 36 is not con~equent to the enjoyment o~
the invention, although thickness which are in common
use may be employed.
Turning now to Fig.4, therein i~ illu3trated a
schematic representation of an indu~trial proce~s for
producinq a multi-layer structure of the invention by
coextrusion techniques.
A wire coating line 40 includes an ~xtruder 50
having two barrels 50A and 50B equippet with a co-
e~trudin~ die 52 capable o~ extruding the pla~ticized
PVC comprising composition including optional
constituents and the PA comprising composition to form
a structure onto the wire 41 in a~cordance with the
present invention. Optionally, the wire ~oating line
40 includea a wire payout reel 42A for supplying wire
41, a wire takeup reel 42~ for collecting wIre 41 after
it ha~ b@en coated, a series of capstan3/pinch rollers
44A, 44B, 44C, 44D which act to guide and/or tran3port
the wire 41, and ~urther equipment, including a wire
; pretreater 46 located before the e~truder 50, a wire
posttr~ater 47, and a m~rking station 48.
The ~roduction procoss ne~cos~ary to enjoy the
benefit~ o~ th~ prs~nt invention aro proces~os which
aro gen~rally utilized to form multi-layorod insulated
wire~ and cableq. Aq ~uch, th~ features of the
proces~es discus~ed in conj~nction with Figs. 4 and 5
are to b~ co~idorod illu~trative, and not limiting.
Gençrally, bare wire 41 i~ playod from the wire payout
re~l 42A where it pa~sos through roller~ 44A and to a
wire protreator 46. The wiro pretroater 46 iq an
optional 2roc~s~ dovico within which tho bare wire 41
- may bo condition~d prior to it~ coating in tho e~truder
50. 5uch conditionin~ may include prehoatin~,
chemical/physical cleaning operatlons, and/or other
operations. ~ub~oquently, the wiro 41 enter~ into the
. :
~,.. .. . ...... . . .
W~92/~3717 PC~/US92t~51l
- ~1 - 21~09~2
crosshead ~upplied by the two extruder~ 50 which
includes a die 52 capable of extruting the two layer~,
i.e. the first layer and the second layer onto the wire
in accordance with the discussion of the constructions
and compositions disclosed above. ~t i~ contemplated
that the two extruders 50 and the coextru~ion die 52
may be any of those presently known to the art, or
those yet to be developed which find utility in
extruding a plurality of layers of material onto a wire
or other structure. One example which is pres~ntly
~nown to the art comprises two extruders each having at
least one hopper for the containmont and feeding of the
PVC comprising composition and the PA comprising
composition which feed their respective constituents to
the heated barrel of each of the extruter~, which
~oftens the re p~ctiv@ composit.ions and which leads to
a suitably formed die 52 which ~sequentially extrudes
the material onto the wiro or other structur~. Such
e~truders typically inclute a rotating screw within
20 each heatet barrel (shown on Fig.4 as 50A an~ 50B) to
effectively mix each of it~ con~stituent~ and to force
it into th~ dio 52. ~he ono-stiag~ o~trusion process
provides bon~fit3 which includo rapid thro~ghput and
overall production ratos.
2 Subss~uent to the cooxtrusion, the o~iting wire 41
ma~ opt~onally be ~ubjoctsd to ~ wire po~ttreater 47
which i~ a condition~r or conditioning st2p ~ub~oquent
to th~ a~plic~tion of th~ insulation structure onto the
wir~ ho po~ttroater 47 may ~ any conditioning
. 30 step or oporation, and might compri~e a cooling
operation, a further heating pro¢oss to drive-off any
organic matorials and/or offect curing of one or both
of th~ layors ~xtrudod onto the wiro 41, a quenchiny
op~ration 3uch as a water bath, or other beneficial
conditioning proces~. Sub~equently, tho wire 41 passes
through further capstans/pinch rollor-~ 44B and may be
pa~ged tD an imprinting station 4a whoroin the exterior
W092/13717 PC~/US~2/~51l
21~095~ of the insulated wire 41 iq marked w1th identl~ying
information in a manner well known to the art.
Sub3equently, the wire 41 pa~es through further
- capstans/rollers 44C, 44D and is taken up by the wire
takeup reel 42B. Thence, the in3ulated wire 41 may be
removed from the wire coating line 40 and utilized.
Fig.5 is a ~urther schematic representation o~ a
process for producing a multi-layer structure of the
invention by a "tandem" extruqion process. Thi3 wire
extrusion line 54 sub~tantively di~ors from that
portrayed in Fig.4 only by tho sub~titution o~ the
single crosshead die 52 as shown on Fig.4 with two
extruder3 60, 64 each with itq own die, 62, 66;
con~equently, ~imilarly designat~d element~ within
Fig.4 and Fig.S are considered intcrchangeable and
commentary concerning their op~ration a~ di~cusqed for
Fig.4 is deemed equivalent and incorporatet herein by
reference. In thi~ embodiment of the invention as
shown on Fig.5, th~ wire 41 entering a suitable die 62
which i~ fed by the extruder 60 and is coated with a
first layer a~ diacussed above. Tho wire 41 thus
provided with the fir~t layer i~ subsequently coated
within a 3econd dio 66 which i~ fed by extruder 64 with
the polyamide layer to form a ~structure in accordance
with the toaching~ o~ tho preaont invention.
In tho foregoing discu~sion of Fig.4 and Fig.5,
tho u~o of multi-layer structures of tho prosent
invention have b~en discus~od and describ0d in
conjunction with the formation of an insulation
~tructure for a wire conductor or wire cable. However,
the utility o th~ invention in other applications
- which might ~ind bone~it i9 not to bo discounted, usage
with othor strand ty~o mat~rials, includlng ~ibars,
optical ~iber~ and the like are expro~sly contemplated.
Further, th~ relative terms "innor" and "outer" have
been u~ed in de~cribing the relative position o~ the
PVC comprising and the PA comprising layers: such a
!
,
RC\~.~'0~ `,l'A ~ Ciii-:`; 01 : 4- ~-9~ 3: '>~)I 46r~ ti~3 ~:3 ~3'J~.-34-W~;:If'~'
2~ 00.952
23
convention h~Li,3 been ~do~ d a~ a ~Lt~er Oe cozlven~ ce
and nc7t a~ a m~;Ltter o~ nece~ y, Con~rruc~on~ ~Jher~
th~ ~A layer ~4ri~f3 thfl n ~n~ern lay~r and the PYC
~, co~3r~in~ layer ~or7~ the '~ou~er" lay~r ars
5 con~i~nplated.
~: In the ot-lowlng embodl~ o the 1~Ye~tlon, lt
li3 ~:0 be uni~eria~cood that: ln the d~cr1ptlon o~ a~y
compos~tion, all p2rce~tage~ oc~ated wlth a
co~ltue~c u~d to f~ co~o~ltlon a~e to ~e
~0 un~er~tood a~ to b~ np~rcent~g~ by Heigh~l' o~ ~he
pa~tlcular conat~tu~nt r~la~lve to the corrq?o0itlo~ of
thich it ~or~3 a pa~t. Bx~p lons ~o thl~ conventiorL
, wlll he par~l~ularly note~.
~x~pl~ 4
A ma~ter~a~ch comprl~ing ~5~ o~ Ca~on~ 8~24 HS, a
~eat ~tabillzed ~ylo~ hom~oly~er contal~i~g r~sin
~e~cribe~ a~ having a ~peciic g~avl y accor~ng to
ASTM D-792 o~ 3, ar.a m~ lng point o~ about 216 ~C
(420 F), ~nd u~ctionally character~zed aa a med~um
v~GosLty, heat ~tablli~e~l ex~ruelo~ gra~a ~es~u
~ul~able ~or extr~ion ~or TH~N, THWN, ~h~pboa~d cable,
bulldin~ wlre, and non~mel;alllc ~hea~hed CablQ prima~y
~: 25 ha~lng ~he fo~ lo~lng ~hy~:Lcal ~hara~rl~tics: ultlma~e
`~ elo~gat~on, about 200 ~ , ~lex ~t~e~th ~bou~ 107~ ba~s
(15,400 ~1), a ~Ls%ural mDdUlU9 0~ a~ou~ Z~OO barB
(377,~00 pal), ~o~ched Izo~ lm~act atre~gth o~ ab~ut
0.53 3/~ 11.0 ~t~ tho ~orm o~ ~elle~, a~
30 15~ by we~yht o~ a ~ho~phc~ce enter co~p~i~l3g
"~' mater~al, Ant~blaze~ 1045 ~o~m~rc~ally aYallable fro~
': . Albrlgh~ a~d ~ o~ 1~ t~e ~0~ o~ a vl~cou~ llqu~
were ~rav~d, to the ~ead o1~ a ~ gle 0¢r~w ex~xuder
o~rat~ng und~r th~ ~oLlowlns c~nd~t1on8: t~mperatura
.S p~otllet zone 1, ~et t~e~atur~, 266 C, zone 2, 0Bt
te~p~ra~ure, 261 C, Z0~8 3, ~et temparatu~, 255 C,
z~n~ 4, ~et temperature 250 C, æo~ et ~e~perature
SlJBS~lTUT S~tEET
,, , , , , , . ,,, ", ., ,, ,, ., ~, .....
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~`i RCV. ~ i E3'A ,~ .CH~:~ 01 . 4- _-9;3 . ) ~_5~ ' 1~ +~ S~ J~
2~ 00952
- 2~ ~
~40 ~C, zone 6, ~t tem~erature 2~0 9C, zone 7, ~et
tempe~atuxe 240 C. ~he ~cr~ o~erated tc rotate
at 10 . 5 rad/~ 0 Rpr~), an~ ~he ~re~ure a~ ~he
~"~ br~alcer plate wa~ reg~s~er~ at 50 bar~ (700 p~ he
5 ex~rudate wa~ ~or~ed ~n~O ~and~ which w~re
~ubse~auen~ly pQlletl2~. The pelle~ wer~ uae~ or ~he
eub~eguen~ ~ormula~lcn and productlon o~ te~ ~arr~lea.
In accordal~cs wlth the p~rcen~a~es ehowrl on Table
1 below, Yar~o~l~ ex~erlme~tal comE)a0~tian0 wlth vary~r.g
10 proport~on~ of th~ ter~atch co~po~l;io~ with ~ur~her
Capr4n~ Ba~4 E~ re~ln wera ~armulak~d and ~ormed into
~ta2ldar~ ~eat bar~3 o~ en~loII~ 15.2 cm by 1.3 cm l~y
. 0.008 c~ ~ 2 ~r. ~y 1/32 1~) in a~ Arburg
ectlo~ mold~ng ~china anâ w~re ~ ec~ed ~or
15 furth~ar e~raluation, which ~e ~oted or~ T~ble 2 whlch
reportY the phy~ical te~t ra~ults o~ ~he te~t
~p~cimens .
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wo g~,l3,l7 2 ~ o o 9 ~ 2 P~/US92/~051 1
- 27 -
Table 3 reports the filldings from the UL-94 f lame
test on f ive standard test bar~ of each of the Exampl e
compositlons.
!
.. . .
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.,, . . ~, . .. .. . .. ..
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WO 92/137~7 PC~US~2/01)51 1
-- 28 --
2~0a~2
3^~!oooc~o ~ ooo~o ooooo
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W~92/137l7 2 1 0 0 3 ~ 2 PCT/US92/~11
- 29 -
Table 4 reports the finding3 from tssts to
determine the Limiting Oxy~en Index, wherein sample~
were teqted in accordance with the protocol outlined
above.
TA~LE 4
Composition~ E~ . 2 ~ Ex. 4
Limiting
Oxygen Index: 28 21 26 22
_________~_____________________________________________
As may be ~een by inqpection, the compo~ition of
Ex.2 is a control sample and dos~ not contain
pho~phonate ester as is taught by the present
invention, but is provided for comparative purposes.
With reference to the properties reported on Table
2, it may be readily observed that with respect to the
flexural prop2rties of E~amples 1,3 and 4 in comparison
with that of Example 2, the Ultimate Tensile Strength
and particularly the Ultimato ~lonqation of thc samples
may be favorably compared partic:ularly the Ultlmate
Elongation o~ Ex.3 and Ex,4, who~e respective value~ of
151~ and 18S~ çompare favorably to the Ultimate
Elongation of the comparative E~camplc 2 with its
reportod value of 198~. Turnin~7 now to tho reported
re3ults of Tablc~ 3 and 4, tho im~rovomont i~ ovon more
striking. Whorea~ tho composit:Lon of Example 2 i9
~how~ o~ Table 3 to fail thc UL-94 Te~tingcProtocol and
be a~igned an "HB" Rating as donoted above, the
results of Exam~lc~ 1, 3 and 4 arc ro~pectively
as~1gned a "94-V-0", "94-v-2" and "9~-V-2" rating with
respoct to their ~iro retardancy in accordance with the
: grading protocol of tho UL-94 ~est briefly discu~3ed
i abovo. Thuo, it may bo 3~n that tho polyamide
compositio~ compri~ing tho pho~phonato ~ter ln the
pcrcentage~ taught to bo preferred foature goad to
excellent fire retardant charactori~tic~ and
W~92/13717 P~t~ 2/0Vg11
- 30 - ...
2 ~ multanoouqly providing good retention of elongation
characteri~tics.
E%amples 5-7
A masterbatch of a plasticized poly(vinyl
chloride) composition typical of compositions known to
the art uqe~ul for extrusion onto electricial current
conductori~, (i.e. wires and cablei~,) which comprised
approximately 55-65~ of a virgin PVC resin, designated
"1095" resin sold by Georgia Gulf Inc., 3-6~ of a lead
stabilizar commercially available under the trade
deqignatian "Dythal- Env" from Anzon lnc. of
Philadelphia, PA, 20-30~ of trioctyltrimellitate
(TOTM), a trimellitate plasticizer, 4-8% of diundecyl
phthalate (DUP), a phthalate plaisticizer, 3-6~ of an
ele~trical grade clay, 1-2~ of antimony o~ide, all of
which are comm~rcially available. A further
constituent in the PVC comprising compo3ition was 3.5%
. of a vinyl chloride comprii~ing copolymer, mor~
particularly a vinyl chlorido/vinyl acetate/vinyl
alcohol terpolymer having a hydroxyl content in exce~s
f 2 percent, which is commercially available from
Union Carbide Corp o~ Danbury, Conn. iand do~ignated a~
"VAG~" te~polymor. This VAGH terpolymor iis described
7' 25 ai~ compri~ing of 90% by woight vinyl chlorido units, 4
by weight vinyl ac~tate uniti~ and 6~ by woight vinyl
alcohol unit , and having a hydro%yl functionality of
about 2.3~ by weight, and a hydroxyl valu~ of 76.
Tho~ materials are further do~crib~d a~ havinq a
spe~ific gravity of 1.39 according to AsTM D792. More
particularly, tho VAG~ rosin is de~cribod as having a
gla3s tran~ition tomporaturo of 79 dog.C, and a number
~ averago molocular woight o~ 27,000. The uise of auch a
: terpolymor i9 taught in currontly copending and
commonly ai~signod U.5. Patant Application Serial No.
S80,232 filcd 9/10/90 which diiscui~i~os the utility of
such a material ai~ enhancing tho adheision of layered
-
RC~ E!'A ,~ .CHE~ 01 : 4~ 3 : "~': ()~) : _ ~)()1 ~I G.'i ~ SJ fl'lJ '):~SJSJ~^1,~;5;: U~fi
.
~ 0 9 ~ 2
- 3~ -
PVC ~omprl~lng la.yex~ a~d PA compri~iny layera, ~hl~
~i.nyl chlorid~-vinyl ~ce~ate-vinyl alcohc~L ~rpolyn~r
,~ may ~e pre3e~t ln an a~rnount t~ con~l~t o~ m~r~ han
zero p~rcen~ an~ le~s rhan lo percent by we~ght o~ the
o~ ~VC com~ri~ing lay~r accox~ing So ~he pre~ent
lnve~tlon .
In a ~enschel ml~r havlng a bowl and a ~lxing
blade, ~he P~tC, Dy~hal-EnV, ~O~rM, DUP, and thq arltl~ony
oxides w~are~ a~e~ a~ r4am temperatu~e an~l 5ub~ ntLy
~horoughly mix~d ~or a~ o~ ely 10~5 mlnu~e~ while
alLowi~g the te~?eratu~e to rl~e. S~b~equentLy tha
elect~lcal grade clay a~d th~ VA~:X t~rpoly~e~ were
addPd wh~n the te~eraturs o~ ~e con~tltuent~ wa~ 88
~ ~190 P), a~d whe~ the ba~ch reach~d 93-9~ C t200-
210 CF~, t~e mixture wa3 du~ed ~ro~ the bowl o~ the
mixer. rhe mlxtuxe wa0 t.he~ p~o~ ed to the ~eed
hopper o a ~hort ba:rrel ~i~gle ~c:rew extruder, a~nd
heated kO plastlfica~e tha ~a~e ~d to fo~n ~trand~
: . therefr~ ~!lhich ~a~ 3equeTltly p~llQtl~ed~
' 20 Sub~uently the pelle~lze~ co~po~ltion produce~
1~ wa~ ~hes~ ~ro~rlded ~o a ~ir~ ex~rudsr hav~ng a ~ax~ler
dox ~cxew ~,qhich s~a~ opexat~d to have a ~emperatu2
o~ a~proxlmately 1~8 C ~370 ~P) acros~ th~ zone~ of
the he~t~d barrel an~ the d~e h~a~. The ~crew ~a~
op~ra~e~ ~co xota'ce at approxl~ately 3.7 ra~ 35 RPM),
the rnotor drsw about 115 am~eres o~ cu~rent, and th3
pre~ ure wa~ ~alntalned at a~?proxlmately 140 bara (2500
p~l). The thxoughput ra~e o~ th~ w~re wao 10 m/~ ~2000
~t/ml~)~ Iuto a ~econd ext~uder e~ od w~th a ~lngle
~ htcd r~Qr~ny cc~w, pel~.etized Capron~ BZ24 %9 wa0
prov~e~ ocond extrU~ talned at the
~ ... .
: ~llowln~ aperatlng co~dltl~: ~e~erature ~ro~lle
i ~ acros~ the heated ~arr~ the d.l~ ~ead, ap~ro7c. 260: C ~5~0 ~). 5he 3cr~ wa~ o~exated to r~tate at
3S about 4.R ra4/~ ~46 R~ he~ m~tor ~rew a~ou~ 4~
am~exe~ o~ curre~, and thQ ~re3~urQ ua~ main~alned at
E;boue 77 ~r~ ~1100 ~
'- SUE~STITlJTE SHEET
~92/13717 PCT/US92tO0511
2~0~2 - 32 - ,~
The plasticized PVC compri~ing cornposition was
first extruded onto a bare 14 gauge solid copper wire
conductor in a 16 mil thick layer, which the Capron~
8224 HS was extruded ther~onto in a 5 ~il thick layer.
The structure ~ormed onto the wiro com~ri3~d the
structure o~ Example 5, which wa3 produced a~, a
comparative example which doe not contain the
pho~phonate ester as is taught by the present
invention.
In a like manner, further structure~ according to
the ~resent invention were produced under th~ sams
conditions, except ~or tho followlng conditions. The
structure of Example 6 utilizod tho samo PVC comprising
composition to form the fir~t layer, whlle the second
layer, the PA comprisin~ la~er which further include~ a
pho~phonate e~ter wa~ e~trudsd onto the first layer
u~,ing the composition according to Example 3.
Similarly, further a further ~tructure designated as
Example 7 utilizing the pla,sticizod PVC compri~ing
compo~ition to form the fir,st layer, and a second layer
formed from tho compo~ition according to E~ample 4 was
e~trudod onto a AWG 14 gauqe solid wire under
~ Qu~tantial}y tha ~ama conditions as those usat to
produce the o~trud~d wiro o~ E~ample 5 above.
Tho wires including the multi-layer ~tructures of
Exa~ple~ 5-7 w~rc subjected to th~ Und~rwritor~
~aboratorie~ U~-9~ "Vortical Burning Tsst for
. Cla3~ifyi~g Mat~rial~ 94-V-0, 94-V-1, 94-Y-2" and the
- r~ult~ ~rom thi~ ts~t is r~ported on Tabl~ 5.
5, '.` '
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. . .
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!, ~, WO 92~13717 2 1 0 0 9 j 2 P~/US92/0051 1 ;,
: -- 33 --
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RCV.~ON~ 'CH~ t,, ~ r~ +~ 3~) 73 ~f~ 'tf;
. _
~1009~2 - 3~ ~
8 ~ 9
qo w~re ~amples comprl~i~g 500,000 (~ ~cwl~ed
trand copper, cn~o trhich wan 2ir0t extruded a 0,1~3 cm
5 ( 0 . 064 1~) thick layez oS t}~ PVC campooltlo~ o~ the
madterbatch o ExarnI?le~ 5-7, atld onto wh~c~ wao
equently extnLdeâ a polya~i~e layer a~ a thick~e3
o~ D, 023 ~m (0.00~ in), ge~e~ally ln acc~r~a~cs with
. ' ~he proceduru d4~cr:5 bed 'cher~ . Por ~he praductlon ~
10 Æxa~ple ~, Caprosl~ ~224 ~ nylc:~ waia u~e~, and ~c;r th~
product~on c~ Le ~, Capron~ 4 Hf3 nylo~ whlch
~u~ her com~rifoe~l 10% ry welf3ht o~ tiblaze~D 10~5.
Sf~ilef~ o~ ~ch~ coat:e~ w~re o~ le~ 8 a~d 9 were
te~t~d ls~ the U~derwriter's habo~a~corie~'s Uh 15~1
15 n~or~zont~l-,gpeclrl~e~ Flame~ Te~t ~or Thermapla~tic- an4
Ru~ber-I~ulated Wl~e~ and Cable3n, Uh 15al de~crlbed
b~la~ly above. The result:3 are outlined an Ta~le 6
below .
q~ 6
U~lderwrl~er' ~bo~at-orlel~ U~ 1~31
-: Bxa~tplQ ~ u~t:a:
.. , .. ... , ~ . . ~
-- - ' Ex. 8 -wl~e ~ bur~ed ~o~ ~8 i~cein~s,
:~ ~5 .no ~Irlppl~g~ OZltO cotton.
Ex,9 ^~o~ ~Ye ~eparate i~lal0, the
~n~ulation ~iel~-ax~lngulshei ln
~-2 i~econdi~.
: 30
';.'~'"5''t A~ a revl~ o~ ~he xee~lt~ o~ t~e ~rarlou~ ~e,Ft
, .,
i W~lL ~onr~aL, the pxe~e~t ln~rq~tio~ pr~l~e~ an i~ro~red
~ ctur~ wh~h exhiblt~ es~celL~int ~ilre,-ri~,tar~a~t
beha,~r~oir, 3~a~ticuLarly ~ eivl~ e~ 1~ the ~ 15~1
3Y ~ox~ontal ~lame ~eat, whlLe ~l~ltanei~iu~ly pr6~ n~1ng
goad ~l~ciki~lity ani~ o~her ~hy~lcal ~irapurt~ei~.
SlJBSTlTUTÉ SWEET
WO92/13717 2 1 n 9 ~ 2 Pcr/ US92/00511
- 35 -
It will be appreciated that the instant
specification~ and examples ~et forth her~in are by way
of illu~tration and not limitation, and that variou3
modifications and changes may be made without departing
; S from the spirit and scope of the pre3ent in~ntion,
who~e limitations are bounded only by the appendant
claims .
:
.
,:
;
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