Note: Descriptions are shown in the official language in which they were submitted.
104~ 9196
The invention relates to polyurethane-iso-
cyanurates that are produced from novolak resins,
polyols, organic polyisocyanates, and a catalyst for
promoting the production of isocyanurate from iso- -
cyanate.
It has been proposed to produce polyurethane-
- Lsocyanurates by reacting an alkylene oxide condensate
of a novolak resin with an organic polyisocyanate in
the presence of a catalyst that promotes the formation
of isocyanurate from isocyanate. The alkylene oxide-
~volak condensates impart a number of useful properties,
such as enhanced thermal stability, to these polyurethane-
i8 ocyanurates. H~wever, the use of alkylene oxide-
novolak condensates incurs additional expenseJ since
these condensates must be produced in a separate step.
The present invention provides a means for
incorporating novolak resins in polyurethane-isocyanurate
compositions without having to produce the alkylene
oxide/novolak condensates in a separate step.
The invention provides a thermose~ composition
containing both urethane and isocyanurate groups, wherein
said composition comprises the reaction product of (a)
~ a novolak, (b) a polyol, (c) a stoichiometric excess of
I an organic polyisocyanate, and (d) a catalytically
J effective quantity of a catalyst for promoting the ~ -
l~ formation of isocyanurate from isocyanate.
.~ .
~ ,
1 q~ : ,
2.
' ' " ' ' ' , ' ' "
i,, , ~. . .,, .. ,.. .,,. ... , ., , . ~, .
- `
104~2 9196
The novolaks employed in the invention are
known compositions that comprise condensation products
of a phenol and an aldehyde, preferably formaldehyde.
Novolaks are known to exist as A-stage, B-stage and
C-stage resins, with the C-stage resin being highly
crosslinked and insoluble and infusible. For the
purposes of this invention, the fusible A- and B-stage
novolak resins are employed. It is known that novolak
resins can be produced using substituted phenols and
that other aldehydes can be used instead of or in
addition to formaldehyde. All of these are known, as
are the methods by which they are produced, and for
the purposes of this invention the term novolak includes
any of the known resins.
A particularly preferred novolak is a compo-
~itlon that can be represented in simplification by
the structural formula:
_ _ l
----¦ CH2~
x
,
wherein J which represents the number of phenol
moieties per molecule, is a number having an average
value of at least about two to about 10. The preferred
compounds are those in which x has an average value
. - .. , ~ ~ , . . , . . - . . .
'' ' . .' '. . ' "'' ' , " ~' " ' '
104~9Z ~196
from about 2.5 to about 8. While, for simplici~y,
Formula I depicts the preferred novolak as being
composed of divalent units, it is, of course, under-
stood that the terminal units are monovalent and that
some of the units may be polyvalent, e.g., trivalent.
The second reactant that is employed in the
invention is a polyol having at least two alcoholic
hydroxyl groups. The polyol, or mixture of two or
more polyols, is selected to have a viscosity such
that a solution of novolak in the polyol has a vis-
cosity which will enable the solution to be conven-
iently handled, e.g., pumped or poured, and mixed
with the other constituents of the reaction mixture
(which are set forth fully hereinafter) at temperatures
within the range of Erom about room temperature up to
about 80C. Thus, the polyol or polyol mixture is
selected 90 that the viscosity of the polyol/novolak
i solution will be below about 9800 centipoises at
reaction temperature, and preferably below about 3600
centipoises at reaction temperature. As will be
readily understood by the ordinary worker in the art,
the selection o the particular polyol or polyol mixture
to meet these requirements will depend, to an extent,
on factors such as proportion of polyol and novolak,
precise nature of the reactants, reaction temperature,
and the like.
, ,
' ~
. 4.
;,
.
~o~ z
9196
Among the polyols that can be employed in the
invention, either singly or in mixtures, are the following:
(a) Polyoxyalkylene polyols including the adducts
of alkylene oxides with, for example, water, ethylene glycol,
propylene glycol, glycerol, l,2,6-hexanetriol, 1,1,1-
trimethylolpropane, pentaerythritol, sorbitol, sucrose,
alpha-methylglucoside, alpha-hydroxyalkylglucoside, ammonia,
triisopropanolamine, ethylenediamine, phosphoric acid,
polyphosphoric acids such as tripolyphosphoric acid, and
phenol-aniline-formaldehyde ternary condensation products.
The alkylene oxides employed in producing the polyoxy-
alkylene polyols normally have from 2 to 4 carbon atoms.
Propylene oxide and mixtures o propylene oxide with
ethylene oxide are preferred.
(b) Polyesters of polyhydric alcohols and
polycarboxyllc acids sucn as those prepared by the
reaction of an excess of ethylene glycol, propylene
glycol, or glycerol, with phthalic acid or adipic acld.
(c) Lactone polyols prepared by reacting a
lactone such as epsilon-caprolactone or a mixture of
epsilon-caprolactone and an alkylene oxide with a poly-
functional initiator such as a polyhydric alcohol, an
amine, or an amino-alcohol.
(d) Phosphorus-containing derivatives such as
tris(dipropylene glycol) phosphite and other phosphites.
(e) The polymer/polyols produced by the in situ
polymerization of a vinyl monomer in a polyol, as disclosed
in U.S. 3,304,273, U.S. 3,383,351 and U.S. 3,523,093.
5.
~ o4~ ~ 9 2 9196
The foregoing are merely illustrative and
represent only a small number of the many polyols known
in the art that can be employed in the invention.
As is known in the art, the foregoing types
of polyols can have a wide range of viscosities, ranging
from about 50 centipoises to very viscous liquids of
about 2300 centipoises or more. (Unless otherwise
stated, specific viscosities are those exhibited by
the polyol at about 25C.) The novolak resins that
will be mixed with the polyol, are normally solid at
room temperature, and even if they are liquid at moderately
elevated temperatures (e.g. J Up to about 50C.), they are
still quite viscous. Therefore, when a very viscous
polyol is used, at least one additional polyol having a
low viscosity should also be employed in the reaction
mixture in order to enable the polyol/novolak solution
to meet the viscosity requirements set forth above.
The proportions of novolak and polyol that
can be employed are not narrowly critical. The pro-
portions depend, to an extent, on such factors as thenature of the materials employed. Normally, the pro-
portion of novolak employed will be within the range
of from about 10 weight per cent to about 60 welght
per cent, based on weight of polyol plus novolak.
While proportions outside these ranges may be used -
in some cases, when the novolak is employed in pro-
portions below 10 per cent, its contribution to the -
~0466~2
9196
properties of the thermoset produc~ tends to diminish.
At proportLons above 60 per cent, the viscosi~y of the
novolak/polyol mixture tends to become impracticably
high.
The novolak resin and the polyol~are reacted
with a stoichiometric excess of an organic polyisocyanate.
Any of the known organic polyisocyanates can be used.
Illustrative thereof are the alkylene diisocyanates,
such as tetramethylene diisocyanate, pentamethylene
diisocyanate, and hexamethylene diisocyanate; cyclo-
alkylene diisocyanates, such as cyclohexylene-1,3-
diisocyanate, and cyclohexylene-1,4-diisocyanate;
aromatic diisocyanates, such as _-phenylene diiso-
cyanate, p-phenylene diisocyanate, polymethylene
polyphenyli80cyanate (i.e., the product produced by
phosgenation of an aniline-formaldehyde condensation
product), 2,4-tolylene diisocyanate, 2,6-tolylene
diisocyanate, mixtures of 2,4- and 2,6-tolylene diiso-
cyanate, naphthalene-1,4-diisocyanate, diphenylene-
4.4'-diisocyanate, bis(4-isocyana~ophenyl)methane
("MDI"), bis(3-methyl-4-isocyanatophenyl)methane and
4,4'-diphenylpropane diisocyanate; aliphatic-aromatic
diisocyanates, such as xylylene-1,3-diisocyanate and
xylylene-1,4-diisocyanate, the polyisocyanates a8
disclosed in U.S. Patent No. 2,683,730, as well as
the polyisocyanates listed in the publication of
Siefken,~Annalen, 562, pages 122-135 (1949). Also
7.
; :
' ' . ' ' ~
~ 04~69Z 9196
included are 4,4'J4"-tris(isocyanatophenyl)methane,
3,10-diisocyanatotricyclo[5.2.1.02~6]decane, bis(2-
isocyanatoethyl) carbonate, and bis(2-isocyanatoethyl)
fumarate. Preferred organic polyisocyanates include ~:
the aromatic polyisocyanates such as tolylene diiso-
cyanate, MDI, and polymethylene polyphenylisocyanate.
Organic polyisocyanates that have been pre-
reacted with a stoichiometric deficiency of ;lll active
hydrogen-containing compound can also be employed.
The organic polyisocyanate is employed in
the invention in an amount in excess of tha~ required
to react with all of the reactive hydrogen-containlng
compositions present in the reaction mixture. Such
reactive hydrogen-containing compositlons include the
novolak resin described hereinabove, the polyoL having
at least two alcoholic hydroxyl groups, and reactive
blowing agents such as water~ which can be employed if
a foam is desired. To illustrate the proportions that
are employed, normally the organic poLyisocyanate will
be employed in amounts such that there are at least
about 1.2, and preferably from about 1.5 to about 5,
equivalents of isocyanato group per equivalent of
reactive hydrogen.
Also included in the reaction mixture is a~
catalyst for promoting the formation of isocyanurate
from is~cyanate. Among the catalysts that can be
employed to promote the formation of isocyanurate
8.
1046~2 9196
from isocyanate are the alkali metal mercaptides.
The alkali metal mercaptides can contain a single ~-
mercaptide group in the molecule, or they can have
larger numbers thereof. The mercaptide can be
aliphatic, aromatic, heterocyclic, cycloaliphatic
or polymeric in nature.. The nature of the mercaptide
compound is not the controlling factor; the presence
in the molecule of the -SM group is the iac~or which
imparts catalytic activity to the molecule. Thus, in
the broadest sense the catalysts can be defined by
the formula:
II X(SM)n
wherein X is the organic moiety to which the -SM
group is attached, and n i9 a number having a positive
value which can be a8 high as six, and even higher in
polymeric substances. The organic moiety X can be
an unsubstituted or substituted monovalent or poly-
valent group. Thus, it can be a monovalent alkyl
group of from 1 to 20 carbon atoms, or an alkenyl
group of from 2 to 20 carbon atoms, or an aryl or
alkaryl or aralkyl group of from 6 to 10 carbon
atoms, or a cycloalkyl or cycloalkenyl group of
from 5 to 6 carbon atoms, or a heterocyclic group
containing ring carbon atoms and nitrogen or sulfur
` or oxygen ring atoms which ring can have 5 or 6
members; or, it can be a polyvalent radical of any
,'
9 ..
.. . , ... ,, ~ .......... . . . ~ ,- ..
. -, . , . ,, - . -
9196
~04~;~92 ~
of said groups when there are two or more SM groups :
attached to the X moiety~ It can also be a polymer
chain to which the -SM groups are attachedO
Illustrative of suitable alkali metal mercap-
tides are sodium n-butylmercaptide, lithium sec-butyl-
mercaptide, sodium hexylmercaptide, lithium decyl-
mercaptide, lithium dodecylmercaptide, sodium 2-hydroxy-
ethylmercaptide, sodium 14-hydroxytetradecylmercaptide,
sodium carboxymethylmercaptide, lithium 2-carboxyethyl-
mercaptide, lithium 9-carboxynonylmercaptide, lithium
4-hexenylmercaptide, sodium phenylmercaptide, lithium
phenylmercaptide, potassium phenylmercaptide, lithium
l-naphthylmercaptide, sodium triphenylmethylmercaptide,
sodium 4-chlorophenylmercaptide, sodium tolylmercaptide,
lithium xylylmercaptide, sodium cyclohexylmercaptide,
and 1,3,4-thiadiazole-2,5-di(sodiomercaptide). Also
suitable are the alkali metal salts of 2-mercapto-
benzothiazole, octane dithiol, and the reaction product
of sodium sulfide with oligomers of epichlorohydrin~
Any alkali metal mercaptide having at least
one mercaptide group in the molecule can be used, in-
cluding the monomercaptides and polymercaptides, pro-
vided that there are no substituents in the molecule
that will unduly interfere with the reaction of the
~socyanato group and formation of the isocyanurate
group. The mercaptides are characterized by the
: ':
10.
.Q4~692
9196
presence in the molecule of at least one mercaptide
group of the formula -SM, wherein M is an alkali metal
atom such as lithium sodium or potassium. The simplest
mercaptldes are those containing only one such group.
However, the compounds suitable for use can contain as
many as 8iX or more mercapto or mercaptide groups in
the molecule. There can also be present in the mercap-
tide molecule other substituent groups, such as carboxyl,
hydroxyl, halogen, ester linkages, ether linkages, amido
linkages, or any other group whlch would not exert a
deterring effect on the reaction.
The alkali metal mercaptide catalyst i8 used
at a concentration of from about 0.01 to about 10 mole
per cent, and preferably from about 0.5 to 5 mole per
cent, the percentage being based upon total equivalents
of isocyanate employed in the process. Any catalytic
amount sufficient to catalyze the reaction can be
employed.
.
A solvent for the catalyst can be used and
for this purpose a suitable organic solvent can be
employed. As examples of useful solvents dimethyl-
, ~ , . .. .
formamide, dimethylsulfoxide, sulfolane, diethyleneglycol, di xane, and tetrahydrofuran are illustrative.
` The alkali metal mercaptides are readily pre-
pared by known methods, one of which is the reaction of
he slkali~metal or the alkali metal hydride with the
rganic mercaptan, preferably in solution. The said
.~ . ~ , .
.
,: ~
, . . . . .
104~6~Z 9196
solution can be used directly in the process of the
invention.
In addition to, or in place of, the above-
described alkali metal mercaptides, other catalysts
can be employed to promote the formation of isocyanurate
from isocyanate. Such other catalysts includ~ an
organic orthoborate plus an alcoholate or phenolate
as disclosed in U.S. Patent No. 3,697,485, and a strong
base such as a tertiary amine, which can be used alone,
but is preferably used with an epo~ide as disclosed in
U.S. Patent No. 3,211,703.
The invention can be employed to produce
solid elastomeric products, surface coatings, cast
ob~ects, molded objects, fiber-reinforced objects,
or flexible, semi-flexible, semi-rigid or rigid foams.
All of these types of products and their specific
utilities are well known commercially, and those
skilled in the art are familiar with the reactants
and techniques necessary to produce a partlcular type
of product. Thus, it is known that flexible products
are obtained in the absence of highly functional
crosslinkers or in the absence of large amounts of
polyols and polyisocyanates having functionalities
greater than two. It is also known that as the
functionality of the reactants is increased the
rigidity of the final product increases. In addition,
it is known that the inclusion of a foaming agent will
12. ~
,:
,
. ~ . . , , ~ .
' ' ~ ' " ... ~ . . ' - . ' . ' "'
.
104~ 2
9196
produce a foam while the exclusion of such agent will
result in a solid nonfoamed product.
The hydroxyl number of the polyol or polyol
mixture plus novolak employed can range from about 20,
and lower, to about 1000, and higher, preferably from
about 30 to about 800, and more preferably, from about
35 to about 700. The hydroxyl number is defined as
t:he number of milligrams of potassium hydroxide required
ror the complete neutralization of the hydrolysis product
of the fully acetylated derivative prepared~from 1 gram
of polyol plus novolak. The hydroxyl number (or "OH")
can also be defined by the equation:
OH G 56.1 x 1000 x f
m.w.
where: f - average functionality, that i~, the
average number of hydroxyl groups per
molecule of polyol plus novolak; and
m.w. = average molecular weight of the polyol.
The exact materials employed depends upon the end-use of
the polyurethane-isocyanurate product. The molecular
weight and the hydroxyl number are selected properly
to result in flexible, semi-flexible, or rigid products.
~he polyol or polyol mixture plus novolak usually
possesses a hydroxyl number of from about 200 to about
l~OO when employed in producing rigid products, from
, :
about 50 to about 250 for semi-flexlble products, and
from about 20 to about 70 or more when employed to
produce 1exible products.
13.
iO46~92 9196
When a fo~m is desired, foaming can be accom-
plished by employing a minor amount (for example, from
about 0.5 to 25 weight percent, based on total weight
of the re~ction mixture), of a blowing agent which is
vaporized by the exotherm of the isocyanato-reactive
hydrogen reaction. Preferred vaporizable blowing agents
include halogen-sub8tituted aliphatic hydrocarbons which
have boiling points between about -40~C. and 70C., and
wh.ch vaporize at or below the temperature of the foaming
ma9s, for example, trichloromonofluoromethane, dichloro-
difluoromethane, and methylene dichloride. Other useful
blowing agents include water and low-boiling hydrocarbons
such as butane, pentane, hexane, cyclohexane, and the like.
Other gases or compounds easily volatilized by the exotherm
of the isocyanato-reactive hydrogen reaction can be
employed. A further class of blowing agents includes the
thermally unstab1e compounds which liberate gases upon
heating, such as N,N'-dimethyl-N,N'-dinitrosoterephthal-
amide.
In addition to the catalyst for promoting the
production of isocyanurate, one can also have pre8ent in
the reaction mixture any of the known catalysts previously
used in the production of polyurethanes. These can comprise,
for example, from 0.05 to 1 weight per cent or more of the
reaction mixture. Illustrative thereof are:
(a) tertiary amines such as N-methylmorpholine,
N-ethylmorpholine, N,N,N',N'-tetramethyl-1,3-butanediamine,
14.
.
. . - : . . : , ~
104~69Z 9196
I,4-diazabicyclo[2.2.2]octane and ~is[2-(N,N-dimethyl-
amino)ethyl] ether;
(b) salts of organic acids with a variety
of metals such as alkali metals, alkaline earth metals)
Al, Sn, Pb, Mn, Co, Ni, and Cu, including, for example,
sodium acetate, potassium laurate, calcium hexanoate,
stannous acetate, stannous octoate, stannous oleate,
lead octoate, and metallic driers such as manganese
and cobalt naththenate, and;
(c) organometallic derivatives of tetravalent
tin, trivalent and pentavalent As, Sb, and Bi, and metal
carbonyls of iron and cobalt.
Small amounts, e.g., about 0.001% to 5.0%
by weight, based on the total reaction mixture, of an
emulsifying agent can be employed when producing foams.
Ixamples include polysiloxane-polyoxyalkylene block
copolymers having from about 10 to 80 per cent by
weight of siloxane polymer and from 90 to 20 per cent
by weight of alkylene oxide polymer, such as the block
copolymers described in U.S. Patents 2,834,748 and
2,917,480. Another useful class of emulsLfiers i9
the group of "non-hydrolyzable" polysiloxane-polyoxy-
alkyl~ne block copolymers. This class of compounds
diffèrs from the above-mentioned polysiloxane-polyoxy- --
alkylene block copolymers in that the polysiloxane
moiety ls bonded to the polyoxyalkylene moiety through
direct carbon-to-silicon bonds, rather than through
15.
.
1 046 6~ Z 9196
carbon-to-oxygen-to-silicon bonds. These copolymers
generally contain from 5 to 95 weight per cent, and
preferably from 5 to 50 weight per cent, of polysiloxane
polymer with the remainder being polyoxyalkylene polymer.
The process of the invention can be carried
out as a one-stage process, which can be carried out
as a one-step reaction wherein all the reactants and
catalyst are reacted in one step to produce the thermoset
composition. Alternatively, the one-stage process can
be carried out as a two-step reaction wherein all or
part of the reactants are pre-reacted to form an iso-
cyanato-terminated prepolymer, which is then contacted
with the catAlyst and any remaining reactants to form
~he thermoset compositions of the reaction.
In another aspect, the process of the invention
can be carried out as a two-stage process. The two-sta~e
process can be carried out by simultaneously reacting all
the reactants and catalyst, but the reaction is interrupted
before a thermoset composition is produced. Instead, this
20 first stage of the process produces a normally solid ~ -
(i.e., solid at room temperature), fusible composition
(such as is often referred to as a "B-stage" material)
that is capable of being transformed by the application
of heat into a thermoset composition. Alternatively,
the two-stage process can be carried out by first pre-
reacting all or some of the reactants to produce a
prepolymer, followed by contacting the prepolymer with
16.
~,
,
, : ........ . . :,, . , . , ... . .. : . -.- , ... . .... :.,.. ,. - .. : . ... . -.. . . . . -
104~692 9196
the catalyst and any remaining reactants to form an
isocyanurate. Again, however, the isocyanurate pro-
duction is interrupted prior to the production of a
thermoset composition, to produce a B-stage compo-
sition tha~ can subsequently be transformed into a
thermoset composition by the application of heat.
The examples set forth below illustrate
certain aspects of the invention. All parts and
percentages are by weight, unless otherwise stated.
In the Examples, the following reactants
were employed:
Novolak A - A phenol/formaldehyde novolak
having an average of 5 to 6 phenol
groups per molecule;
Polyol A - Polypropylene glycol having an
average molecular weight of about 1000
and a viscosity at room temperature of
100-130 centipoises;
I Polyol B - Polypropylene glycol having an
average molecular weight of about 425
and a viscosity at room temperature of
65-100 centipoises;
Polyol C - The condensation product of
epsilon-caprolactone and diethylene
glycol, having an average molecular
weight of about 530 and a viscosity at
50-60C. of 65-100 centipoises;
17.
~ . . .-.. ~ . , . . . ,:
. 9196 :~
1 ~46 6 9 2
Isocyanate A - The reaction product of excess .:.
tolylene diisocyanate (TDI) with a propylene ;~ .
oxide adduct of glycerine having a hydroxyl
number of 650, said reaction product having
a free isocyanate (NCO) content of 32 weight
per cent;
Isocyanate B - Same as A, except that the free
NCO content is 30 weight per cent;
Isocyanate C - The reaction product of excess
TDI with the propylene oxide adduct of
sorbitol having a hydroxyl number of 490,
said reaction product having a free NCO
content of 28 1 weight per cent;
Catalyst A - Sodium phenyl mercaptide (NaSC6H5); .
Catalyst B - Disodium mercaptoacetate
(NaSCH2COONa); and :
~ Catalyst C - Dibutyltin dilaurate.
¦ EXAMPLES 1-12
ONE-STA OE PRODUCTION OF POLYURETHANE-
ISOCYANURATE THERMOSET COMPOSITIONS
¦ Standard Procedure - The novolak was mixed
I in the polyol, and the mixture was then heated in a
circulating air oven to a temperature of 40-70C.,
the catalyst was added to the novolak/polyol solution, and
the isocyanate was then added with rapid stirring, to give
l~ a homogeneous reaction mixture. Molded thermoset plaques
¦~ about 20 mils thick were then produced by pouring the reac-
tion mixture into a heated (260DF.) mold, that was maintained
,' ~.
18.
1046~Z 9196
at a pressure of about 300 to 500 p.s.i. (At the
catalyst concentrations employed, after 10 seconds
of stirring, from 2 to 5 seconds remained within
which to transfer the reaction mixture into the
mold before gelation occurred.) After 3 to 5 minutes,
~he plaques were demolded and were allowed to cool
.slowly to room temperature.
Table I, below, sets forth the nature and
amount of the reactants, the ratio of isocyanate to
hydroxyl in the reaction mixture, the catalyst and
catalyst concentration, and the molding time. The
novolak employed in each case was novolak A.
.
19 .
. .
9196
1()46f~92
~o
::-
-- o
~ o~ u~ ~
~, ~ ~ ,, o ,, o ~ o o o o o
~ ~ C o o o o o o oo o o o o o
~q
.
H ¢ fq m ¢ m ~ ¢c~ ~ ¢ ¢ ~ m : .
,~ ~
~ ~1 ,, o o ~1 o o o~ o o ~ o o
H I ~ ~ ~ u~ u~ CO l~ 11~
~ ~ ¢ ~ c~ ¢ ~ c~ ¢ c~ ¢ ¢
o ~ ~ u'~
x ~ ^ l~ ~ c~ o ~ ~
o
~u 2 ~ ~ ~ ~ ~ ~ ~ ~
2~ ~ ~ ~ ~ 2~ 2; 2~ 2;`
co CO ~ ~D ~ cO ~o cO ~O ~O ~O ,.
c~ c~ ¢ ¢ ¢ m m m
' - . .
~ ~ N ~) ~ ~
. ".
20.
.
,: .. . . : -
~04~69Z 9 196
The viscosities of the polyol/novolak -
solutions of these Examples were as follows:
Polyol and
Polyol/novolak
Wei~ht Pro~ortion Viscosity, centiPoises
C, 80/20 2500-3000 at room
temperature
600-700 at 60C.
A, 60/40 6340 at 70C.
9850 at 60C.
B, 60/40 9800 at 60C.
B, 80/20 1000-1300 at room
temperature
400 at 60C.
Representative properties of these molded
plaques are set forth below in Table II (properties
were not determined on Examples 2 and 5). The test
procedure employed for determining tensile strength,
tensile modulus, and elongation at break ~as
20ASTM D-638.
,
'
9 196
~046692 :
bD C~ U~ ~ ~ ~ O ~ U~
E~ o ~ ~ ~ O~
.
C.l
.t,
~ ~ ~ ~ o~
U; C~
~ .~ .~ U~
~ ~ ~ ~ U~ ~ ~
H ~1 3
~ ~ ,.,
~ P 8 8 8 8 8 8
~:; r~ ~ O Q 0 8
o ~ ~D ~U O O ~ o ~ o O o
U~ : ,,
.
~n
o o o o o o o (~ o o
^ O O 5 0 0 0 c) ~ o o . .
Ul O O ~ O O O O O O O
c ~ 1 u~
~1 O~ C-- ~ aD Ir~ O t~
. CU CU C~ ~ ~ ~ ~r~ ~ ~ .,
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''
~ 1
.
22 .
.
104~692
9196
EXAMPLE 13
TWO-STAGE PRODUCTION OF GLASS FIBER-
REINFORCED THERMOSET COMPOSITION
To a solution of 80 parts by welght of
polyol C and 20 parts by weight of novolak A (total
weight - 305 grams; 1.5 equivalents of hydroxyl),
there was added 0.1 milliliter of a 1 M solution of
disodium mercaptoacetate in ethylene glycol (0.005
weight per cent of catalyst, based on weight of
polyol/novolak mlxture, and 0.009 weight per cent,
based on weight of tolylene diisocyanate). Tolylene
diisocyanate (145 grams; 1.7 equivalents of NC0) was
added to the mixture at 60-70C., and the mixture
wa~ rapidly ~ransferred to a cylindrical container,
which was placed on a lathe revolving at 1000-1200
revolutions per minute. Glass fibers (1/4-inch longj
125 grams) were added to the revolving container, and
were unifonmly mixed with the reaction mixture by the
force generated by the spinning container. A tack-
freé, B-stage composition was obtained in about 5 to
10 minutes. The material was stored at room temperature
for three days, and was then compression molded (3 to 5
minutes at 190C. and 300-500 psi) into a thermoset
plaque. The plaque had the following properties:
Tensile strength - 3,450 psi
Tensile modulus - 143,000 psi
Elongation at Break - 7.9 per cent
Notched Izod Impact - 11 foot-lbs/inch of notch
(by ASTM ~25~-72)
:, :
23.
9196
,
~046692
EXAMPLE 14
A solution of 60 parts by weight of Polyol B
and 40 parts by weight of Novolak A (total weight -
150 grams; O.99 equivalent of OH) was mixed with 260
grams of TDI (3 equivalents of NCO) at 60 to 70C.,
without catalyst, To the resulting isocyanato -
terminated prepolvmer, there was added 154 grams (1.01
equivalents of OH) of a 60:40 (by weight) solution of
Polyol B: Novolak A containing 0.15 milliliter of a
1 M solution of disodium mercaptoacetate in ethylene ~ .
glycol (catalyst concentration - 0.008 weight per cent,
based on weight of TDI). The reaction mixture was
thoroughly mixed, and was allowed to form a tack-free
B-stage composition. Compression mol~ing at 190C.
and 300-500 psi for 3 to 5 minutes yielded a clear
thermoset plaque. The properties of this plaque were
as follows:
Tensile strength - 7,810 psi
Tensile modulus -942,000 psi
Elongation at break - 1 per cent
Notched Izod Impact - 7.6 foot-lbs/inch of notch
EXAMPLE 15
An isocyanato-terminated prepolymer was
produced by a procedure analogous to that described
in Example 14 from 218 grams of TDI (2.5 equivalents
of NCO) and 100 grams of a 60:40 (by weight) solution
of Polyol B and Novolak A (0.66 equivalent of OH).
24.
. - . . - , ,. , ~ . ~. ~ .
lO~ Z 9196
The prepolymer was then mixed, at 60-70~C., with 204
grams (1.34 equivalents of OH) of a 60;40 solution of
Polyol B and Novolak A containing 0.15 milliliter of
~ 1 M solution of disodium mercaptoacetate in ethylene
glycol (catalyst concentratlon - 0.009 weight per cent,
based on TDI). The reaction mixture was then quickly
~ransferred to a cylindrical container mounted on a
lathe spinning at 1000-1200 rpm. Glass fibers (1/4-
inch; 140 grams) were added to the mixture, and were
uniformly mixed with the reaction mixture by centrifugal
force. A tack-free B-stage material was obtained in
10 to 15 minutes. Compres8ion molding of thls B-stage
material at 190C. and 300 to 500 psi for 3 to 5 minutes
yleLded thermo~et plaque8 having the following properties:
Tensile 8trength - 8,430 psi
Tensile modulus - 1~050,000 psi
E~ongation at break - 1 per cent
Notched Izod Impact - 7.9 foot-lbs/inch of notch
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