Note: Descriptions are shown in the official language in which they were submitted.
8CH-2194
lSO
Novel foamable resin compositions are disclosed that
include an alkenyl aromatic resin, an organic phosphate and
a sulfonyl semicarbazide. These compositions preferably
include a polyphenylene ether resin.
The polyphenylene ether resins are a well known
family of engineering thermoplastics that are well known
to the polymer art. These polymers may be made by a variety
of catalytic and non-catalytic processes from the correspond-
ing phenols or reactive derivatives thereof. By way of ~-
illustration, certain of the polyphenylene ethers are dis-
closed in Hay, U.S. patent No. 3,306,874 dated February
28, 1967 and U.S. patent No. 3,306,875 dated February 28,1971,
and in Stamatoff, U. S. 3,257,357 dated June 21, 1966 and
U.S. patent No. 3,257,358 dated June 21, 1966. In the Hay
patents, the polyphenylene ethers are prepared by an oxida- -
tive coupling reaction comprising passing an oxygen-containing
gas through a reaction solution of a phenol and a metal~
amine complex catalyst. Other disclosures relating to
processes for preparing polyphenylene ether resins, including ;~-
graft copolymers of polyphenylene ethers with styrene type
compounds, are found in Fox, U.S. patent No. 3,356,761 ~-
dated December 5, 1967 - Sumitomo, U.K. 1,291,609 dated
November 23, 1965; Bussink et al, U.S. patent No.3,337,499
i ~ :
dated August 22, 1967; Blanchard et al U.S. patent No. :
3,219,626 dated November 23, 1965; Laakso et al, U.S. `~ ;~
patent No. 3,342,892 dated September 19, 1969; Borman U.S.
patent No. 3,344,166 dated September 26,1967; Hori et al
U.S. patent 3,384,619 dated May 21, 1968; Faurote et al U.S. `~
3,440,217 dated April 22, 1969 and disclosures relating to ;
metal based catalysts which do not include amines, are
known from patents such as Wieden et al, U.S. patent No.
3,442,885 dated May 6, 1969 (copper-amidines); Nakashio
8CH-2194
lOl~lrjO
et al, U. S. Patent ~o. 3,573,257 dated March 30, 1971
(metal-alcoholate or -phenolate); Kobayashi et al, U.S.
3,455,880 dated July 15, 1965 (cobalt chelates); and the
like. In the Stamatoff patents, the polyphenylene ethers
are produced by reacting the corresponding phenolate ion
with an initiator, such as peroxy acid salt, an acid
peroxide, a hypohalite, and the like, in the presence of
a complexing agent. Disclosures relating to non-catalytic
processes, such as oxidation with lead dioxide, silver
oxide, etc., are described in Price et al, U.S. patent No.
3,382,212 dated May 7, 1968. Cizek, U.S. patent No.3,383,435
dated May 14, 1968 discloses polyphenylene etherstyrene
resin compositions.
One of the outstanding properties of the polyphenylene
ether resins is the property of high-heat resistance which
makes possible the use of this resin in applications where
many thermoplastics would fail. This exceptional property,
while desirable in a finished article, causes problems
when melt blending is used to form compositions that in-
clude the polyphenylene ether resins. One problem isrelated to the fact that the high temperatures required
for the processing of the polyphenylene ethers approach the
temperatures at which additives begin to degrade. This
problem is especially serious when compositions are for-
mulated which include chemical blowing agents that are
added to a foamable thermoplastic composition as the tem-
peratures at which the polyphenylene ethers are processed
are sufficient to activate most thermolabile blowing agents. -
It has now been found that sulfonyl semicarbazides
may be blended with polyphenylene ether resin compositions
that include an organic phosphate compound and an alkenyl -
aromatic compound, at temperatures that are low enough to
: .
:, .
., .
10~3i~0 8CH-2194
prevent the activation of the flowing agent. These compositions
may be prepared by first preparing a concentrated preblend
of the polyphenylene ether, the alkenyl aromatic resin,
the organic phosphate and the sulfonyl semicarbazide.
Optionally, the concentrated preblend may be prepared
without any polyphenylene ether. The preblend may be
combined with either a polyphenylene ether resin or a blend
of a polyphenylene ether resin, an alkenyl aromatic resin, ~ -
an organic phosphate in addition to conventional additives
such as tri-decylphosphite, zinc oxide, titanium dioxide ;
and zinc sulfide.
Accordingly, it is a primary object of this invention
to provide novel foamable thermoplastic compositions that
include a polyphenylene ether resin.
It is also an object of this invention to provide novel
preblended compositions of an alkenyl aromatic resin, an -
organic phosphate and a sulfonyl semicarbazide.
,~ : .
U.S. Patent No. 3,639,506 dated February 1, 1972
discloses compositions that include polyphenylene ethers,
styrene resins and a phosphate. This reference does not -
disclose foamed polyphenylene ether resin compositions.
The present invention provides novel foamable ^
thermoplastic compositions which comprise~
(a) from 0-90 parts by weight of a polyphenylene ~ether resin; -
(b) from 5-95 parts by weight of an alkenyl aromatic
resin; ~
:~.
B
8CH-2194
9150
(c) from 5-40 parts by weight of a phosphate compound;
and
(d) from 0.05-30 parts by weight of a sulfonyl semi-
carbazide of the formula:
R - SO2 - NH - NH - CO -NH2
where R is alkyl, aryl or alkyl substituted aryl.
The polyphenylene ethers are preferably of the formula:
o
n .
Q :
wherein the oxygen ether atom of one unit is connected to the
benzene nucleus of the next adjoining unit; n is the degree
of polymerization; and each Q is a monovalent substituent
selected from hydrogen, halogen, hydrocarbon radicals, hal-
ohydrocarbon radiclas having at least two carbon atoms the
halogen atom and the phenyl nucleus. ~
20The preferred polyphenylene ether resin is poly(2,6- :~`
dimethyl-1,4-phenylene ether) resin having an intrinsic : :~
viscosity of about 0.5 as measured in chloroform at 25C
The alkenyl aromatic resin should have at least 25% ~:
of its units derived from a monomer of the formula~
R5 CRl = CHR2
~: R6 ~ R4 . :
. .:
wherein R and R2 are selected from the group consisting of
30lower alkyl or alkenyl groups of from 1 to 6 carbon atoms and ~--
8CH-2194
0
hydrogen; R3 and R4 are selected from the group consisting
of chloro, bromo, hydrogen and lower alkyl of from 1 to 6
carbon atoms; R5 and R6 are selected from the group consisting --
of hydrogen and lower alkyl and alkenyl groups of from l I :~
to 6 carbon atoms or R5 and R6 may be concatenated together ~ :
with hydrocarbyl groups to form a naphthyl group, said
compounds being free of any substituent that has a tertiary ~
carbon atom. -- .
Materials that may be copolymerized with the alkenyl
aromatic monomer include those having the general formula~
R8 . ,` ~ -
(II) R - C(H) - - - C _ _ _ (CH2)m ~ R9
wherein the dotted lines represent a single or a double --.
carbon to carbon bond, R7 and R8 taken together represents a :~
11 9 ~ ' '' ~'
C- O - C linkage, R is selected from the group consisting
of hydrogen, vinyl, alkyl of from 1-12 carbon atoms, alkenyl
of from 1-12 carbon atoms, alklcarboxylic of from 1-12
carbon atoms or alkenylcarboxylic of from 1-12 carbon ~:
:~ atoms, n is 1 or 2, depending on the position of the carbon- .. ~.
carbon double bond, and m is an integer of from 0 to about
10. Examples include maleic anhydride, citraconic anhydride, .
itaconic anhydride, aconitic anhydride, and the like. :.
The general formulas set forth above include by way of
example, homopolymers such as homopolystyrene and monoch-
loropolystyrene, the modified polystyrenes, such as rubber- ~:-
modified, high-impact polystyrene and the styrene-contain-
ing copolymers, such as the styrene acrylonitrile- ~ alkyl
styrene copolymers, styrene-acrylonitrile copolymers,styrene ~ ~
butadiene copolymers, styrene-acrylonitrile butadiene co- ~ ~-
,
- 5 -
, ,~., .. . .. ., ... , . ~ . . - , . :
. :~. - . : ~. .. - . - .. . .. :
,.. ~:- ~ . :
.,. :- : . .
8CH-2194
lOl~iSO
B polymers, poly - d -methylstyrene, copolymers of ethylvin-
ylbenzene, divinylbenzene and styrene maleic anhydride co-
polymers and block copolymers of styrene butadiene and
styrene-butadiene styrene.
The styrene-maleic anhydride copolymers are described
in U. S. Patent No. 3,971,939 dated July 27, 1976, U.S.
Patent No 3,336,267 dated August 15, 1967 and U.S. patent
No. 2,769,804 dated November 6, 1956.
The rubber-modified, high-impact styrene resins are
preferred and these may be made by well-known procedures
with rubbers such as nitrile rubbers, polybutadiene rubber, `
styrenebutadiene rubber, polysulfide rubber, ethylene pro-
pylene copolymers, propylene oxide and EPDM. These materials
are well known and many are commercially available. A
preferred rubber-modified, high-impact styrene resin is
commercially available as FG-834. This product contains `
about 8% polybutadiene.
The phosphate compound may be selected from compounds ~ -
of the formula:
~ "~
QO P oQ
I
where each Q represents the same or different radicals that
are selected from the group consisting of alkyl, such as
straight and branched chain alkyl of from 1 to 10 carbon
atoms such as methyl, propyl, n-butyl, hexyl, heptyl and
the like; cycloalkyl such as those cycloalkyl radicals
having from 1 to 8 carbon atoms such as cyclopropyl;,
cyclobutyl, cyclohexyl and the like; aryl such as those aryl
,~................................................................... .
. . :
r
8CH-2194
10~"3i~iO
radicals having from 6 to 14 carbon atoms such as phenyl
and naphthyl; alkyl substituted aryl such as those radicals
having from 1 to 5 straight or branched chain alkyl radicals
having from 1 to 10 carbon atoms on a phenyl or naphthyl
nucleus, e.g., 2-methylphenyl, 4-n-butylphenyl, 2- ethyl-
phenyl and the like, aryl substituted alkyl such as phenyl
or naphthyl substituted straight or branched chain alkyl
radicals having from 1 to 10 carbon atoms such as benzyl,
phenethyl, phenpropyl and the like; hydroxy alkyl having ~ ~
from 1 to 10 carbon atoms such as 2-hydroxyethyl, 4-hydroxy- ~ -
heyl and the like; hydroxyaryl such as hydroxyphenyl or
.~
hydroxynaphthyl, e.g., 4-hydroxyphenyl and the like;
hydroxyalkaryl such as cresyl, 4-ethyl-2-hydroxyphenyl and
the like; halogen such as chloro, bromo or fluoro; and -~
hydrogen.
The phosphates may be selected from cresyl diphenyl
phosphate, 2-ethylhexyl diphenyl phosphate, tricresyl
phosphate, triiosopropylphenyl phosphate, triphenyl phosp-
hate, triethyl phosphate, dibutyl phenyl phosphate, die-
thyl phosphate, cresyl diphenyl phosphate, isooctyl dip-
henyl phosphate, tributyl phosphate, 2-ethlhexyl diphenyl
phosphate, isodecyl diphenyl phosphate, isodecyl dicresyl
phosphate, didecyl cresyl phosphate, tri-n-hexyl phosphate, -~
di-n-octyl phényl phosphate, di-2-ethylhexyl phosphate
or mixtures thereof. ~ ~
'~. ';
;~ The preferred compositions will have from 5-50 parts~ ~ ;
by weight of a polyphenylene ether resin; from 20-95
parts by weight of an alkenyl aromatic resin; from 5-40 -~
~; parts by weight of the organic phosphate and 1-30 parts
by weight of the sulfonyl semicarbazide.
For convenience, concentrated compositions may be
prepared that have high concentrations of the sulfonyl
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.,,.~,.-. i, . . .. . . .
8CH-2194
10~9iS0
semicarbazide. These compositions may be blended with blends
of polyphenylene ether and styrene resin to prepare the
actual composition that is foamed. The concentrated com-
positions may include from 5-50 parts by weight of a polyp-
henylene ether resin; from S0-90 parts by weight of an
alkenyl aromatic resin; from 10-30 parts by weight of an
organic phosphate compound; and from 2-25 parts by weight
of the sulfonyl semicarbazide.
The sulfonyl semicarbazides are commerically available
and the individual members of this group may be prepared
by reacting the corresponding sulfonyl hydrazides with an
alkali cyanate in an acidic medium in accordance with
standard techniques.
The compositions of the invention may also include rein- -
forcing amounts of reinforcing fillers. If a reinforcing
filler is added, it may comprise from 10-40 parts by weight ~-
of the composition. If a concentrated composition is pre- ~ -
pared, it should be formulated without a reinforcement to ;
facilitate blending.
The reinforcing fillers may be selected from rein-
forcing fillers such as aluminum, iron or nickel, and the
like, and non-metals, such as carbon filaments, silicates
such as acicular calcium silicate, asbestos, titanium
dioxide, potassium titanate and titanate whiskers, woll-
astonite, glass flakes and fibers. It is also to be
understood that, unless the filler adds to the strength
and stiffness of the composition, it is only a filler and
not a reinforcing filler.
In particular, the preferred reinforcing fillers are
of glass, and it is preferred to employ fibrous glass
filaments comprised of lime-aluminum borosilicate glass
that is relatively soda free. This is known as "E" glass.
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8CH-2194
lV~ tj~
However, other glasses are useful where electrical pro-
perties are not so important, e.g., the low soda glass
known as "C" glass. The filaments are made by standard
processes, e.g., by steam or air blowing, flame blowing
and mechinical pulling. The preferred filament diameters
range from about 0.000112 to 0.00075 inch, but this is
not critical to the present invention.
The length of glass filaments are not critical to the
invention. However, it is convenient to use the filamen-
tous glass in the form of chopped strands of from about
1/8 inch to about 1 inch long, preferably less than 1/4 ~-
inch long. The best properties are usually encountered
when the filament lengths lie between about 0.000005 inch
and 0.125 (1/8) inch.
The foamable compositions may be used for the pre- -
paration of molded parts of business machines, applicance
parts, electrical boxes and the like. For certain ap-
plications, it is desirable to employ a composition having
a low amount of a foaming agent to eliminate "sink" in ~ ~ -
molded articles. The low amounts are in the order of
0.1-2 parts by weight. Generally the density of the
foamed articles will be less that 1 and preferably about
0.75 to 0.9. The compositions may be molded under con-
ditions that are generally employed for standard poly-
phenylene ether resin compositions, except that usually
"short shooting" is employed, or in other words, only a
minimum amount of molding composition to fill the mold
is used when the foamable compositions of the invention
are molded.
The alkyl, aryl and alkyl substituted aryl substituents
of the sulfonyl semicarbazides may be selected from methyl,
ethyl, propyl, n-butyl, n-hexyl, decyl etc.; phenyl and
_ g _
8CH-2194
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naphthyl; and 4-methylphenyl; 3-methylphenyl; 2-methyl-
phenyl; 4-ethylphenyl; 4-butylphenyl; etc.
If desired, other additives may be employed in the disclosed
compositions for stabilization, flame retardancy and the like.
EXAMPLE 1
The following blend was prepared on a Werner Pfleiderer
twin-screw extruder with the zone temperatures set at
180/250/330/330/350F. at zones 1-5:
Parts by weight
poly(2,6-dimethyl-1,4-phenylene ether)*10 ~ ;
rubber-modified, high-impact polystyrene** 70
tri-phenyl phosphate 20
p-toluene sulfonyl semicarbazide*** 10
The melt temperature was 330F. and the torque was 400 -~
inch-pounds. The composition was easily stranded and pelletized.
* PPO, General Electric Co. having an IV of about
0.5 as measured in chloroform at 25C. -~
,, ~: .
** FG-834 ;~
*** Celogenl RA ~.. :" ;~
The following blend was prepared by the method and --
materials prepared in Example 1:
Parts by weight
poly(2,6-dimethyl-1,4-phenylene ether) 15
rubber-modified, high-impact polystyrene 65
. . .
tri-phenyl phosphate 30 : -~
p-toluene sulfonyl semicarbazide 10
The melt temperature was 340F. and the torque was
400 inch-pounds. The composition was easily stranded and
pelletized. ~-
The following blend was prepared by the method and
materials of Example 1:
. . .
1 Trade Mark
B -lo- ~ ~
8CH-2194
10~'-31S0
Par~ by weight
poly(2,6-dimethyl-1,4-phenylene ether) 15
rubber-modified, high-impact polystyrene 65
tri-phenyl phosphate 30
p-toluene sulfonyl semicarbazide 30
The melt temperature was 345F. and the torque was ~
400 inch-pounds. The composition was easily stranded and - -
pelletized.
The following blend was prepared according to the methods
and materials of Example 1 without any poly(2,6-dimethyl-1,4-
phenylene ether).
Parts by weight ~
rubber-modified, high-impact polystyrene 80 ~ ;
tri-phenyl phosphate 20
p-toluene sulfonyl semicarbazide lO
The melt temperature was 340F. and the torque was 250
inch-pounds. The composition was easily stranded and
pelletized. ~ ;
The preparation of the following blend illustrates the
higher melt temperatures and extruder torque that are re-
quired when the phosphate compound is eliminated from the -~
blend~
Parts by weight
rubber-modified, high-impact polystyrene 100
p-toluene sulfonyl semicarbazide lO
The melt temperature was 380F, and the torque was 700
inch-pounds. The extruder composition showed immediate
and gross decomposition of the chemical blowing agent and
could not be stranded.
The preparation of the following blend also ill-
ustrates the higher melt temperatures and extruder torque
that are required when the phosphate compound is eliminated
- - 11 -
~ O 8CH-2194
from the blend:
Parts by weight
poly(2,6-dimethyl-1,4-phenylene ether) 10
rubber-modified, high-impact polystyrene 90
p-toluene sulfonyl semicarbazide 10
The melt temperature was 360F and the torque was 750
inch-pounds. The extruder composition showed immediate and
gross decomposition of the chemical blowing agent and could
not be stranded. -
Athough the above examples have shown various modifica~
tions of the present invention, other variations are possible
in light of the above teachings. It is, therefore, to be
understood that changes may be made in the particular em-
bodiments of the invention which are within the full intended ;
scope of the invention as defined by the appended claims.
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