Note: Descriptions are shown in the official language in which they were submitted.
~17~36
1 This inven~ion relates to liquid polyure~hane prepolymer
compositions; also to solid polyurethane compositions having
easy reentry property; also to a package of liquid polyurethane
prepol~mer composition an.d of a liquid curi.ng solution therefor;
and also to a method of encapsulatingO emhedding or suxface
protective coating a solid article to whic~ future access (re-
entry) is desired~
Since approximately 1955, when the initial use of plastic
shea~h telephone cables beg~n to be used ~y the operating tele-
phone companies in the United States, there have been a variekyof m~hods and kechni~ues concerning the protection of splice
connections. ~hese have varied from such devices as hermeti-
cally sealed metal and plastic cases, to multiple layers of
tape wrappings; adaptation of lead sleeving, plastic and metal
de~ices ha~ing rubber and neoprene grommets, as well as total
encapsulation in ma~y varied closures using such diversified
fillers as paraffin, wax, tar, epoxy, and polyurethane, to
mention a ew. More recently, there have been a nwmber of
attempts to utilize polye~hylene jelly and variations of this
type ma~erial for wa~erproof encapsulation of wire connections -
yet remain somewhat reentera~le.
The ever increasing application of buried wire and ~able
has brought about ~he requirements to develop a more foolproof
: closure method for both new splicin~ as well as repair of
damaged wire a~d cable that would result in extremely high
waterproo~ integrity, yet not invol~e undue cost for materials
nvr excessive time in labor required to do ~he work. To date,
for one reason or another~none o~ the closures nor materials . .-
offered met all of the demanding requirements of the operating
telephone compa~ies. Namely, 1) very low cost; 2) exkremely : -
~imple; 3) l~w labor; 4) quickly reenterable; 5) safe o~ any
type plastic insulated wire~ .
, . ,: ' ''.' . :
'~7~16
1 The mat~rial whic~ most nearly met th~ above x~quirements
was developed a few years ago and is a soft cable jelly, com-
mercially available as ICKYPIC II Cable Jelly. Unlike other
jellies~ this material could be safely used on older poly-
e~hylene insulated conductor~, as well as on the newer poly-
propylene insulated conductors. Thi9 meanl: that it could be
applied on all existing plastic sheath cables used since 1955
in the telephone industry throug~out the United States. Although
hig~ly successful, it had a distinct disadvantage in that work-
men, generally speaking, abhorred the use o~ any jelly-type
material because in each case it was soft and sticky, and has
a propensity to quickly transfer to workmens' tools, clothes,
o~her pieces of materials, etc. While meeting many desirable
r~quirements as previousl~ mentioned above, it was obviousl~ not
the final solution for waterproo encapsulation of telephone
cable and service wire splices.
A. ~IQUID POLYUR~TH~E PREPOLYMER COMPOSITI~N:
Prepolymer A
The liquid polyurethane prepolymer composition of the in-
vention compri~es an ~CO (isocyanate) group containing compo-
sition made from:
(a) organic diisocyanate:
~b) aliphatis txiol of a molecular weight of about 1500- .
60~0,
D o~~t~ the ~CO/~H ratio of said diisocyanate and said triol
charged is a~out 1.0-1.6; and
~C~
~ liquid, organic plasticizer material essentially inert
to ~CO reaction and essentially compatible wi~h the diisocyanate- -
triol reaction product;
~ said organic plasticiæer being present in a~ amount to
provide a composition having an ~CO content o about 1.2-~.5%;
and
-2-
7~
said triol providing the bulk of the weight sum of the
said diisocyanate, triol and organic plasticizer charged. Here-
inafter, the aforesaid prepolymer composition will be referred
to as "Prepolymer A".
Prepolymer Al-
-
A more specific liquid polyurethane prepolymer composition
of the invention comprises an NCO group containing composition
made from:
(a) aromatic diisocyanate;
(b) polyoxypropylene derivatives of alkanetriol where
alkane has 3-6 carbon atoms, having a molecular weight of about
1500-6000;
the NCO/OH ratio of said diisocyanate and said triol
derivative charged is about 1.3; and
(c) liquid, plasticizer ester of (i) alkanol, alkanediol
oxyalkylenediol, or polyoxyalkylenediol and (ii) alkanoic acid
or alkanedioic acid, said ester is essentially compatiL~le with
the diisocyanatP-triol derivative reaction product, and has a
viscosity of not moxe than about 75 centipoises at about 20C
said ester being present in an amount to provide a com~
position having an NCO content of about 1.5-1.8~ and a viscosity : :
of about 1300-1800 centipoises at 21.1 C (70 F) . Hereinafter
the aforesaid more specific prepolymer composition will be re-
ferred to as "Prepolymer Al".
Prepolymer A2::
A particular exemplary liquid polyurethane prepolymer
composition of the invention comprises an NCO group containing
composition made from: .
~ 3 ~
:
: . . . . . .
.
' ': .`, :' ` :, ,
~L~7~6
(a) tolylene diisocyanate, about 7.1 weight parts;
(b) polyoxypropylene derivative of trimethylolpropane,
of molecular weight about 4500, about 68.1 weight parts; and
- .
.
-
':~
.: - , . . ~........... ' . ' :
: , . : ' ,, ; ~
~44~
1 ~c) dioctyl adipate, about 24.9 weight parts;
said compositiQn having an ~CO content of about 1
~ o~ 7~
weight percent and a viscosity of about ~ centipoises at
21.1C (70F). Hereinafter the aforesaid exemplary prepolymer
composition will be referred to as "Prepol~mer A2".
B. THE CURI~G SOLUTION COMPOSITIO~:
Curin~ Solution B:
Curing solution composition for use with Prepolymer A con
sists essentially of:
~a) a curing agent, in a curing amount, for the polyure-
thane prepolymer composition of Prepol~mer A selected from khe
class consisking of polyols, organic diamines and aminoalkanols;
(b) liquid, organic plasti~izex material essentially inert
to ~CO reaction and essentially compatible with cured, solid
polyure~hane comp~sition o~ this invention; and
(c) organo-metallic cong?ound e:Efective for catalyzing the
ambient temperature reaction of iso~anate groups and h~droxyl
or amine groups, and soluble in said plasticizer (b~ ~bove. . :
HereinaEter, the aforesaid curing so:Lution co~position will be
~0 referred to as "curing solution
Curinq solution Bl:
A more specific curin~ solution composition of t~e inven
tion consists essentially o~
~ a) a curing agent, in a curin~ amount, ~or ~he polyure-
khane pxepolymer composition of Prepolymer A selected from the
class o aromatic di~mines, alip~atic diamines and ~minoalkanols;
(b1 liquid, plasticizer ester o~ ~i) alkanol, alkanediol,
oxyalkylenediol, or polyoxyalkylenediol and (ii~ alkanoic acid
or alkanedioic acid, said ester is ~ssentially compatible with
the cured, solid polyure~hane composition of this invention; and
(c) a soluble organo-me~allic compsund effective for caka-
: lyzing ~he ambient temperature reaction of isocyanate groups with
1 hydro~yl or amine groups. Hereinafter, the aforesaid more
sp ci~ic curing solution will be referred to as "curing
solution Bl".
Curinq solution B2:
A particular exemplary curing solutio.il of the inventionconsists essenti~ly of:
(a) ~,N,~'vN~-tetrakis(2-hydroxypropyl) ethylene diamine
curing agent, about 2.7 weight parts;
(h) liquid, plasticizer 2,2,4-trimet~yl-l, 3-pentanedlol
diisobut~rate, about 9703 weight parts; and
~ c) a soluble lead catalyst, suc~ as lead octoate, about
O.04 weight parks. Hereinafter, the aforesaid exemplary curing
solution will be referred to a~ "curing solution B2".
C. ~ sIrIo~:
The solid, polyure~hane composition of the invention
possesses structuxal strength against re~o~di~g forces and
also possesses the ~aracteristic of crumbling under shearing
force appli~d to ~he surace of the solid or from ~he interior
of ~he solid, permitting t~e solid to ~e removed from anoth~r ~ ~:
2a solid object e~capsulated by, or embedded in, or pro~ective
coated on a surace khereof, o~ said solid polyurethane; the
solid polyuretllane composition consists essentially of,
(I) a:Eoresaid prepolymex A; and
aforesaid curing solultion B: ~
said prepo~ymer P~ and said curing solution B when intermingl~d ~-
cure~ at am~ient tempexatures, to solid polyuret~ane composi-
; tion possessing ~he afor~said crumbling characteristic,
A more specific solid po~yurethane eompo~ition of the in-
vention, possessing ~he hereinabove set forth characteristics,
consists essentially of
(S) aforesaid prepolymer Al; and
(I~) aforesaid curing solution Bl~ in an amount to produce
~37~6
1 a solid polyurethane comæosition ha~ing a Shore hardness of
about 7~15 in a time of not more than about 30 minutes at about
20C and possessed o~ th~ aforesaid crumbling characteristic.
A particular exemplary solid polyurethane composition of
the invention~ possessing the hereinabove set forth character
istics~ consists essentially of:
(I~ aforesaid prepolymer A2; and
(II~ aforesaid curing solution B2, and w~en abouk equ~l
weight parts of tI) a~d (II) are intermingled at about 21olQC
a ~olid polyuxethane, having a Shore hardness of about 10, is
obtained in about 10 minutes.
D T~E TWO-PART P~CKAG~ ASSEMBLY
_, _
In another aspect, the invention is directed to a two~part
package asse~bly adapted for produ~ing a solid polyurethane
composition ~hen ~he contents of ~he ~wo parts are intermingled,
which assembly consists essential~y of:
(I) a first package part conta:ining aforesaid Prepolymar
A; and
(II) a second package part containing aforesaid curing
solution ~.
In a more specific a~pect, the ~wo-part package assembly
is adapted to produce a solid polyurethane composition w~en
the contents of the two parts are intermingled, which as~em~ly
consiæts essentially o~:
(I~ a firsk package part containing aforesaid Prepolymer
A; and
(II) a second package part containing aoresaid curing
solution Bl, in an ~mount to produca a solid polyurethane compo-
sition havin~ a Shore hardness of about 7-15 in a time of not
more than ~bout 30 minutes at about 20C.
A particular exemplary two-part package assemhly adapted
for producing a solid polyure~hane composition wh~n khe contents
~7~6
1 of the two parts are intermingled, which assembly consists
essenti~lyof:
(I~ a first pac~age part containing aforesaid Prepolymer
A2; and
(II3 a second package part containing a~oresaid curing
solution B2; and when about e~ual weight parts of (I) and (II)
are intenmingled at about 21.1C; a solid polyurethane, having
a Shore hardness of about lO is obtained in a~out lO minutes.
E. METHOD OF E~CAPSUhATIO~ AND THE LIK~.
.
A method of encapsulating a cable splice, or capping a
cable end, or embedding a solid article, or protective coating
a surface with a solid waterproof resilient reenterable poly- . ;
urethane which method comprises~
(1) intermingling to form a flowable liquid composition; ~;.
(I) aforesaid Prepolymer A;
(II) aforesaid curing solution B; and
(2) placing said liquid composition into contact with
the outer surfaces of said splice, or end, or article, or :~:
surfa~e~ at ambient temperature for ~he time needed for the
liquid composition to cure to a solid having the a~oresaid
characteristics.
A more specific method of the invention comprises:
~1) intermingling to form a flo~able liquid composition;
(I) aforesaid Prepol~mer Al; and ;
(II) aforesaid Prepol~mer B1, in an amount to produce a
solid polyuret~ane composition having a Shore hardness of about
7 15 in a time o~ not more than about 30~minutes at about 20C
and posses~ed of the afore described crumbling c~aracteristic; ..
and
~2) placing said liquid composition into contact with
surface described hereinabove at ambient temperatuxe for ~he time
needed for ~he liquid composition to cure to a solid having the
- ' , ' ~
~7~8~
1 aforesaid characteristics.
A particular exemplary method of the invention compri~es:
(1) intermingling to form a flowable liquid composition;
(I) aforesaid prepolymer A2, and
(II) aforesaid prepolymer B2; and when about equal parts
by weight of (I) and (II) a~e intermingled at about 21.1C,
a solid polyure~hane having a Shore hardness o a~ou~ 10 is
o~tained in about 10 minutes;
(2~ placing said liquid composition into contact wi~h
surface ~escribed hereinabove at ambient temperature for the
time needed for the liquid composition to cure to a solid
having the aforesaid chara~teristics.
DESCRIPTION A~D EX~MPLE
P~ r ~9a~ ' '
The liquid polyurethane prepslymer c omposition of ~he :
invention m~y be prepared from any suitable organic diisocyanate.
Particular classes used include: aromatic diisocyanates; ali-
phatic diiso~yanates; cycloaliphatic diisocyanates; and hetero-
cy d ic diisocyanates.
Illustrative aromatic diisocyanates are: (it is to be
understood "diisocyanate" must be read at the end of each of
the following terms) tolylene; tolidine; xylylene; phen~lene,
napht~ylene; dianisidine; l-chloro-2~4-phenylene; 3,3'-dimethyl-
; 4,4'-dip~enylmethane; 4,4'-diphenylmethane;3,3'-dimethyl-4~4'-
biphenylene; 3,3'-dimet~oxy-4,4~-biphenylene, 2,2'5,5'-terameth~l-
4,4'-biphen~lene; 4,4'-diphenylisopropylidene; 3,3'-dimethyl-4,
4'-diphenyl; 3,3'-dimethoxy-4,4'-diphen~
Illustrative aliphatic diisocyanates are: (it is to be ~:
understood "diiso~yanate" must be read at the end of each of : :
the following~erms) methylenebis (cyclohexylisocyanata) lno di
term] methylene 7 ethylene; trimethylene; tetxamethylene;
hexamethylene; 18 carbon atty acid dimer.
,~ ,,
~aD7~ 6
1 I llustrati~e cycloaliphatic diisocyanates are: cyclohexylene
diisocyanat2, 1-isocyanato-3-isocanatomethyl-3,5,5-trimethyl
cyclo~exane, and isophorone (3,5,5-trimethyl-2-cyclohenen-1-
one diiso~yanate).
A typical heterocyclic diisocyanate is furfurylidene
diisocyanate.
The triol(s) used in preparing the prepolymer composition
of the invention is aliphatic triol of a molecular weight of
about 1500 6000, desirably 3000-6000.
A suitable triol is a mixture of castor oil glycerides
transesterified to im~rove reactivity with isocyanate groups.
The desired triols are derivatives ~adducts) of a trihydric
compound with ~n alkylene oxide~ or mixtuxes thereof, haviny
2-4 carbon a~ms~ such as, e~hylene o~ide, propylene oxide, and
bu~ylene oxide.
Preferred are the aliphatic triols which are polyoxyalky lene
derivatives of alkanetriol, where the "alkylene" poxtion has 2-4
car~on atoms and the "alkane" portion has 3-10 carbon atoms,
Especially preferred are: "alkylene" is propylene; "alkane" has
3-6 carbon a~ms; and the d~rivative m~lecular wPight is about
4000-5000.
Illustrati~e alkanetriols are: glycerol (1,2,3~propanetriol);
butanetriol; pentanetriol; hexanetriol; trime~hylolethane; tri-
me~hylolpropane; and triet~ylolpropane.
The ~CO/OH ratio of the diisocyanate charged and the triol
charged to the prepol~mer reaction is about 1.0-1~6 and preferably
is about 1O3.
m e prepolymer composition of th~ invention includes a
liquid, organic plasticizer material essentially inert to iso-
cyanate (NCO) and essentially compatible with t~e prepolymer
! product itself~ "Compati~le" is used herein in ~he sPnse o
"ability ~o becomé and to remain ~lended with" the liquid pre-
_g_
8~
1 polymer and the solid pol~ure~hane o~tained by reaction of the
prepolymer, either self-reaction or with a curing agent. Many
compounds accepted as excellent plasticizers exhibit blooming,
or exudation~ or slight separation from the solid composition
(even liquid composition) on long storage, particularly at
higher amhient temperakures (temperatures commonly prevalent
in the atmosphere or in buildings)~ The term "essentially
compatible"includes such plasticizer materials.
It is preferxed that the plasticizer component be n~utral,
ine~t to isocyanate, have low volatility, and relatively low
viscosityO that is, not more t~an about 75 centipoises (cps) at
20C. A vast nu~ber of suitable plasticizer matexials are listed
in Modern Plastics Encyclopedia, 1973-74 Edition.
A preferred plasticizer material is an ester of alip~atic
hydroxy compound and aliphatio carbox~lic acid or aromatic
car~oxylic acid. Especially preferred plasticizer materials are
the esters of (a) alkanol~ alkanediolO oxyalkylenediol, or poly-
oxyalkylenediol and (b) alXanoic acicl or alkaned~oic acid.
; Especially preferred ester compounds axe: dio~tyl adipate
which has a ViSCQSity of about 12 cps and a boiling range of
--~ about 214C at 5 mm Hg pressure; and 2,2,4-trimethyl-1,3-pentane-
R ~ `so6~fyrQ~
diol ~bhh~Y~o~#~be. Other plasticizers of roughly these charac-
teris~ics appear in said Modern Plastics Encyclopedia listings.
Inertness to ~CO is essential in order to produce a "water-
white"prepolymer and solid polyure~hane composition. ~ven slig~t
reactivity causes a white cloudiness to show i~ the product;
this may not be detrimental for many applications o~ the pre-
polymer and/or solid polyure~hane composition of ~he invention.
The liquid polyurethane prepolymer composition (prepolymer
and plasticizer) has an ~CO content o about 1.2-2.5%. The
amount of ~CO present determines~ in ~he main, the speed with
which gelationtakes place on intermingling the prepolymer compo-
--10--
.
. '': , , . . .. - , ,
1 sition and the curing solukion. Lower ~C0 contents favor faster
times. with the components of prepolymer A2 and curing solution
B20 it has been observed that 1~2~2.5% ~C0 .~orresponds roughly
to about 5-60 minutes gelation time at a 70~F (21~1C)o
A preferxed ~C0 content of the prepol~mer composition is
about 1~4-2~/o~ For encapsulation of cable splices and cable
end capping~ an N~O con~ent of about 1.5-108% is particularl~
preferred.
The bulk (major portion) of the weight sum of the triol,
diisocyanate, and plasticizer charged to the prepolymer reaction
is provided by the triol. Adjustments can be made in the vis-
cosity of the prepolymer composition by ~ontrollingtheamount
of plasticizer charged. For cable work and like usage, suf-
ficient plasticizer is present to provide a composition having
a viscosity of about 1300-1800 cps at 70F (21.1C),
B ~ 5~ Y~ Y~
r
The liquid organic plasticizer material component of the
curing solution is of the same scope as the p~asticizer material
present in the prepolymer COlnpOSitiOn. It is preferred ~hat
the pa~tlcular plasticizar ma~.erial in the curing solution be
the same as the plasticizer in the prepolymer ~omposition, for
example, if the prepolymer composition includes dioctyl adipate
plasticizer then it is pre~erred that the curing solution include
dioctyl adipate pla~ticizer. ~ :
An organo-metallic compound effective ~or catalyzing the
: ambient temperature xeaction of isocyanate groups and hydxoxyl ::
groups or amino groups, which is soluble in the plasticizer com-
ponent, is present in the curing solution. A large number o~
suitable organo-metallic compounds are ~nown to be effective.
30 The more common are khe phenate, chlorophenate, naphthenate,
oleate, linoresinate ~ ethylhexanoate, acetylacetonate, butoxide,
sal~s of lead, iron, tin, co~alt, vanadium, titan~um, copper,
1 zinc~ ~hromium, manganese and ca~mium~ Sol~ble lead salts,
su~h as, lead octoate, lead naphthenate, lead oleate, and
lead linoresinate, are pxeferred catalysts for use in this
invention.
The ~mount of catalyst present is relatively smalls it
will be dependent on the t~pe and amount of curing agent and
the time of gelation desired. In general, the lead catalyst
will be present in about O~Ol-l~/o of the total curing solution;
and commorlly O.01-0.3%~
The curing solution includes a curing agent, either a poly-
ol, an organic diamine, or amino alcohol.
The organic diamines include the atomatic, aliphatic and
cycloaliphatic diamines. Illustrative are~ benzidine, phenylene,
diaminP.-methylenebis(chloroanilirle), diaminodiphenylmethane,
~imek~ylene diamine, tetramethylene diamine, hexamethylene
diamine~ tetrame~hyl-l 9 3-butanediamine, and diethylcyclohex~l
. diamme.
The ~minoal~ohols such as ~minoalkanols are Xno~n curing
agents. Illustrative are ethanolamine, dimethylethanol~mine,
aminobenzyl alcohol, and M~ON',~'-tetrakis~2-hydroxypropyl)-
ethylene diamine~ ~
Sufficient curing agent is used to o~tain a solid poly- :
ure~hane composition. The amount used wi~l ~ry with the MCO
content of the prepolymer composition and ~he particular curing
agent, but, in general, ~he curing agen~ usage will range from
about 1% to 5% ~y weig~t of the curing solution.
The plasticizer, cuxing ~ent and organo-metallic compound ~:
are mat~hed to provide a solution o~ the three components. The
plasticizer is present, in effect, 100 parts minus the amount
of curing agent present as the usual catalyst usage is tin~.
The "Cured'' Solid P ~ :
Encapsulation and the ~ik
-12-
~ , .
, ~ , . .
1 In preparing the prepolymer composition/ it is customary
to blend ~he plasticizer component and the isocyanate component
befor~ adding the triol~ The isocyanate removes an~ sli~hk
amount of water which may be dissolved in t:he plasticizer.
Anhydrous materials do not need this precautionO The three
components are intermingled at about 150-170F ~65.6-76.7c), a
typical prepolymer reaction tempexature. ~he product is a
viscouS9 liquid having a color from water-white to pale yellow.
The curing solution may require heating to about 40C
(104~ to bring all the diamine and catalyst into solution.
The prepolymer composition and the proper amount of
curing sol~tion are rapidly intermingled at ambient temperature.
The blend is ~hen applied (placed in contact with) the surface
of the object which is to be encapsulated, embedded, or coated
as the case may be. The blend i~ maintained in place ~or the
time needed for the liquid to gel. There is no significant
exotherm in the reaction.
~ he solid polyurethane pro~uct is usually crystal-cleare
some xeactio~s may produce a white cloudinessO
Th~ solid product i~ wate~pxoof and an electrical insula~or.
Tha solid product does adhere to the metal, plastic, paper or
such, interface and provides a wa erproof interface. The solid
product has resiliency; a mass dropped on a hard surace will
rebou~dO
The unique property of this solid product is its response
to shearing foxce applied to a sur~ace, such as~ rubbing a finger
on th~ surface. And its response to the shearing fo~ce of a
wire e~3edded in a ~c~c of ~he solid product and being withdxawn
~hrough the ~lock. The solid crumbles in response to shearing
force and breaks up into small pieces. The interface ~etween
the solid product and the o~her sur:Eace easily ~leaves wi~h
some crur~ling o:E the adjacent solid product surace, freeing
-:L3
~7~ !36
1 the o~her surface of all of the solid prsductO Metal wires,
plastic coated wires, paper coated wires~ pull through the
encapsulating solid product clean and are ready for "working".
The crumbled material does not stic~ to Skill or clothing,
so presents no clean up problems~ a~ do all the prior art re-
enterable cable materials. Lony storage tests indicate ~his
crumbling property does not change with age.
Another very desirable property of the solia product is
its abili~y to be added to itselfO Fresh liquid composition
applied to solid product appears to have perfect cohesion,
effecting an absolute marriage of ~he old solid and ~he resh
solid at the interface. This property means that partial re- ~ -
entry into a splice encapsulated by the solid product is satis-
factory; it is not necessary to remove the entire encapsulating
material.
Another benefit lies in ~he fact that this product is
neither expanding nor shrinking on solidification.
The ~wo-Paxt Package
The aforedescribed prepolymer composition and the a~ore-
described curing solution must be packaged separately for hand-
ling, shipping and storage. T~erefore, a two-part package is
necessary and the two parts are nonmally handled and stored
together and are spoken herein as a "two-part package asse~blyl'.
When ~he consumer wishes to prepare a batch o liquid blend
for encapsulation or other use, the necessary amount of each
part o ~he package asse~bly is measured out and ~he two amounts
are intermingled and the blend is placed in contact with the
surface to be pxotected and/or insulated. Usually ~he two-pa~t
package is sized so that ~he entire contents of each part are
used in a single blending operation. It is desirable that the
closure on at least the prepoly~er compo~ition package part be
air-tight to pxevent ingress of atmospheric moisture which re-
-14-
~7~
acts with composition. The package may be any conventional
container, such as, removable lid can, screw cap bottle, sealed
can when the entire contents are to be used in a single blending
operation, sealed plastic or metal tubes for very small jobs,
and the like containers.
Especiall.y useful for small or medium applications in the
fie].d is the unitary two-part plastic package assembly dis-
closed in U.S~ patent 3,639,952. This unitary plastic package
comprises an elongated tubular plastic film open-ended container
provided with a removable means placed transversely across the
container at the midlength thereof to form two separate tubular
portions, the desired amount of aforesaid prepolymer composition
is placed in one portion whose open end is then sealed; and the
desired amount of aforesaid curing composition i5 placed in the
other portion whose open end is then sealed, whereby said two
compositions are maintained separate until the separating means
is removed; the two compositions are then intermingled within
the plastic film container, and the blended flowable liquid
composition is taken therefrom prior to gelation of the liquid
`composition, and placed into contact with the surface to be
protected and/or insulated by the cured solid polyurethane pro-
duct composition. ;-
~ Example
A prepolymer composition of the invention was prepared
from the following components, 2,4-tolylene diisocyanate, 7.1
weight parts; polyoxypropylene derivative of trimethylolpropane,
4500 molecular weightl 68.1 parts; and dioctyl adipate, 24.9
parts.
- 15 -
The diisocyanate and the adipate were placed in a vessel
and heated at 163-170F (71.1-76.7C) for one hour. Then the
triol was added to the vessel and the contents intermingled for
two hours at the same temperature.
The prepolymer composition had an NCO content of 1 weight
percent. It had a density of 8.30 lbs/gallon (US) and is sub-
stantially colorless. It had to be stored under a dry nitrogen
atmosphere.
The curing composition was prepared from the following
components: 2,2,4-trlmethyl-1, 3-pentanediol diisobutyrate,
97.3 weight parts, N,N,N',N'-tetrakis(2-hydroxypropyl)ethylene
diamine, 2.7 parts; and lead octoate catalyst, 0.04 weight parts.
The three components were brought into solution by
mixing at 100-110 F t37.3-43.3 C). The curing solution was clear
in color~ had a density of 7.95 lbs/gal (US) and a viscosity of
about 40 cps at 70 F (21.1 C).
One part by weight of the prepo]~mer composition and one
part by weight of the curing solution was thoroughly inter-
mingled to form a homogeneous blend. The ~lend was applied to
a bundle of plastic coated copper wires in an in-place filling.
The blend gelled in 9-10 minutes at 700F (21.1C); another
blend of the same composition gelled in 35 minutes at 40F
(~ ~C)
Some of the blend was placed in a gelling dish made of
aluminum with rough vertical sides, 2.5 inches in diameter by
0.5 inches deep. The dish was filled to about 0.25 inches.
There was no noticeable exotherm on curing. Also no noticeable
expansion o~ shrinkage in volume of the material placed in the
~kl .
~ - 15 -
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dish. After curing, the solid was as close to colorless as
the term water-white connotes. The solid depressed slightly
under finger pressure but rebounded on release of pressure.
The solid did not stick to the skin when pressed by the finger.
The solid did adhere to the metal tightly and formed a
watertight interface. However, the metal foil easily peeled
away from the solid polyurethane and the bottom contact was
easily overcome and the solid polyurethane disc slipped out
of the dish.
It was observqd the edges of the disc were rough from
crumbling of the wall as the metal foil was peeled away. Rubbing
- 16a -
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1 ~he disc surface with fingers caused substantial crumbling of
the material. Shearing force easily bro~e chunks from the edges
of the disc.
However, the disc when dropped several feet onto a hard
floor did not shatter or brea~ up. The disc bounced. When
dropped on an edge, the disc bounced much like a ru~er ball.
A test on the embedded (encapsulated) plastic coated wires
revealed that the wires pulled sideways cut through the solid
polyurethane mass and the plastic surface was free of the
encapsulating material. The encapsulating solid broke up into
pieces easily, these pieces did not stick to sXin, clothing,
or to other surfaces on wh~ h ~hey lay.
Tests showed that the solid polyurethane product is a
good electrical insulator~
While the pa~ticular polyurethane composition h~ving easy
r0entry property herein shown and disclosed in detail is fully
cap~ble of attaining the objects and providing ~he advantages
hereinbefore stated, it is to be understood ~hat it is merely
illustxative of the presently preferred embodiment of the i~en-
tion and ~hat no limitations are intended to the detail of ::
construction or design herein sh~wn other than as defined in ~he
appended claimsO
-17-
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