Note: Descriptions are shown in the official language in which they were submitted.
~3~ CH-2582
This invention rel'ates to aromatic polycarh~nate resins
haviny resistance to high heat dlstortion.
BACKGROU~JD OF THE INVENTION
-
Polycarbonate'polymers are known as being excellent molding
materials since products made therefrom exhibit such properties
as high impact streng-th, toughness, high transparency, wide
temperature limits (high impact resistance below -60C and a UL
thermal endurance rating of 11~C with impact), good dimensional
stability, good creep resistance, and the like. It would be
desirable to add to this list of properties that of resistance
to high heat distortion thereby enabling these aromatic polycar-
bonates to also be used to form molded components that will be
exposed to elevated -temperature environments such as components
exposed to automobile and airplane engines, and the like.
It is known to obtain polycarbona-tes which contain halogen-
ated monomers as their main, polymeric building blocks. For
example, U.S. Patent 3,028,365 discloses a hos-t of polycarbonate
compositions including tetrabromobisphenol-A and a dichloromethyl-
enediphenol monomer, as well as processes for obtaining these
polycarbonates.
U.S. Patent 3,062,781 discloses that halogenated polycar-
bonates can be obtained by first halogenating a diphenol contain-
ing at least two halogen substituents. However, the only dihalo-
genated diphenol disclosed is dichlorobisphenol-A.
German Patent R25 20 317.2 discloses that halogenated
polycarbonates can be obtained by halogenating bisphenol-A
(4,4'-isopropylidenediphenol) to produce a mixture oE unreacted
bisphenol-A and statistical mixtures of halogenated bisphenol-A
(BPA). The halogenated bisphenols disclosed comprise, primarily,
^`.:~jJ `, ~ . .;, .r
~3~3~ 8CH-2582
tri- and tetrahalogenated BPA.
In general, these prior art references recognize -that flame
retardance can be imparted to polycarbonates by halogenating the
monomeric building blocks from which they are obtained. None of
these references, however, discloses or suggests thak a high
molecular weight polycarbonate resin having resistance to high
heat distortion as well as improved flame retardance can be
obtained from a particular dihalogenated diphenol.
SUMMARY OF THE INVENTION
It has now been found that resistance to high heat distortion
can be imparted to high molecular weight, aromatic polycarbonate
resins by selecting appropriate diphenols to be halogenated. In
general, this is accomplished by controlling the degree -to which
the particular diphenols are halogenated. Accordingly, the
diphenols are halogenated so that there are obtalned either highly
pure dihalogenated diphenols or predetermined statistical mixtures
comprising predominantly mono- and dihalogenated diphenols
together with some unreacted diphenol.
Preferably, these predetermined, statistical, halogenated
diphenol mixtures can be continuously obtained by either:
(1) dissolving or suspending the diphenol in a solvent system
comprising methylene chloride and water and thereaft~r introducing
a halogen into the solvent system; or, (2) dissolving or suspend-
ing the diphenol in methylene chloride and then reacting the
diphenol with sulfuryl chloride and~ op-tionally, introducing
- ano-ther halogen therein; or, (3) dissolving or suspending -the
diphenol in methylene chloricle and introducing a halogen -therein
while concurrently purging the reaction with an iner-t gas. These
processes are described in United States Paten-t Number
2 -
~ 8C~1-2582
4,210,765 datecl July 1, 1980, which is assigned to the same
assignee of this case.
While any of the halogens can be employed, chlorine
and bromine are preferred and the halogenated diphenols can also
include a lower alkyl moiety. Thus, the diphenols that can be
used to obtain the high molecular weight axomatic polycarbonates
of the invention can be represented by the general formula
( ){~.
Xm
wherein Xm and Xn can each independently be a halogen and
mixtures thereof; m and n are each 0.0 to about 2.5 with
the proviso that m + n equal at least 0.1 and no more than
about 2.5; Y is a ~l-C4 alkyl, hydrogen, and mixtures thereof;
and, R is a C3-Cg alkylene. In formula I above, the values
of m and n represent the number of halogen substituents
per mole of monomer.
Typical of some o~ thé diphenols that can be
employecl in this invention are 4,4'-(cyclohexylidene)diphenol,
~,4'-(cyclopentylidene)diphenol, 4,4'-(cycloheptylidene)diphenol,
4,4'-(cyclooctylidene)diphenol, 4,4'-(cyclohexylidene)di-
o-cresol, 4,4'-(cyclopentylidene)di-o-cresol, 4,4' (cyclo-
heptylidene)di-o-cresol, 4,4'-(cyclooctylidene)cli o-
cresol, and the like.
It is possible to employ two or more different
d.iphenols or a copolymer with a glycol or with hydroxy
or acid terminated polyester, or with a dibasic acid
in the event a carbonate copolymer or interpolymer
rather than a homopolymer is desired for use
-- 3 --
8CH~2582
~3l3~
in preparing the aromakic polycarbonate. Blends of any of these
ma-terials can a]so be used to obtain the aromatic polycarbonates.
These halogenated diphenols can then be employed to obtain
the high molecular weight aromatic polycarbonates of the i~ven-tion
which can be linear or bxanched homopolymers or copolymers as well
as mixtures thereof or polymeric blends and which generally have
an intrinsic viscosity (IV) or about 0.40-1~0 dl/g as measured in
methylene chloride at 25C. These high molecular weight aromatic
polycarbonates can be typically prepared by reacting the halo-
genated diphenol with a carbonate precursor.
The carbonate precursor used can be either a carbonyl halide,
a carbonate ester or a haloformate. The carbonyl halides can be
carbonyl bromide, carbonyl chloride and mixtures thereof. The
carbonate esters can be diphenyl carbonate, di-(halophenyl)
carbonates such as di-(chlorophenyl) carbonate, di-(bromophenyl)
carbonate, di-(trichlorophenyl) carbonate, di-(tribromophenyl)
carbonate, etc., di-(alkylphenyl) carbonate such as di(tolyl)
carbonate, etc., di-(naphthyl) carbonate, di-(chloronaphthyl)
carbonate, phenyl tolyl carbonate, chlorophenyl chloronaphthyl
carbonate, etc., or mixtures thereof. The haloformates that can
be used include bis-haloformates of dihydric phenols (bischloro-
formates of hydroquinone, etc.) or glycols (bishaloformates of
ethylene glycol, neopentyl glycol, polyethylene glycol, etc.).
While other carbonate precursors will occur to those skilled in
the art, carbonyl chloride, also known as phosgene, is preferred.
Also included are the polymeric derivatives of a dihydric
phenol, a dicarboxylic acid and carbonic acid such as are dis-
closed in U~S. Patent 3,169~121 dated February 9, 1965,
- Goldberg. This class of compounds is generally referred
to as copolyestercarbonates.
~s~
,~
~CEI-25~2
Molecular weight regulators, acid acceptors and catalysts can
also be used in obtaining the aromatic polycarbonates of this
invention. The useful molecular weight regulators include mono-
hydric phenols such as phenol, chroman-I, paratertiarybutylphenol,
parabromophenol, primary and secondary amines, etc. Preferably,
phenol is employed as the molecular weight regulator.
A suitable acid acceptor can be either an oryanic or an
inorganic acid acceptor. A suitable organic acid acceptor is a
tertiary amine such as pyridine, triethylamine, dimethylaniline,
tributylamine ! etc. The inorganic acid acceptor can be either a
hydroxide, a carbonate, a bicarbonate, or a phosphate o~ an
alkali or alkaline earth metal.
The catalysts which can be employed are those that typically
aid the polymerization of the diphenol with phosgene. Suitable
catalysts include tertiary amines such as triethylamine, tripro-
pylamine, N,N-dimethylaniline, quaternary ammonium compounds such
as, for example, tetraethyla~,monium bromide, cetyl triethyl
ammonium bromide, tetra-n-heptylammonium iodide, tetra-n-propyl
ammonium bromide, tetramethylammonium chloride, tetramethyl
ammonium hydroxide, tetra-n-butyl ammonium iodide, benzyl-trimethyl
ammonium chloride and quaternary phosphonium compounds such as,
for example, n~butyltriphenyl phosphonium bromide and methyltri-
phenyl phosphonium bromide.
Also included herein are branched polycarbonates wherein a
polyfunctional aromatic compound is reacted with the diphenol and
carbonate precursor to provide a thermoplastic randomly branched
polycarbonate. These polyfunctional aromatic compounds contain
at least three functional groups which are carboxyl, carboxylic
anhydride, haloformyl, or mix~ures thereof. Illustrative of
- 5 -
3~ 8cH-2582
polyfunctional aromatic compounds which can be employed include
trimellitic anhydride, trimellitic acid, trimellityl trichloride,
4-chloroformyl phthalic anhydride, pyromellitic acid, pyromellitic
dianhydride, mellitic acid, mellitic anhydride, trimesic acid,
benzophenonete-tracarboxylic acid, benzophenonetetracarboxylic
anhydride, and the like. The preferred polyfunctional aromatic
compounds are trimellitic anhydride and ~rimellitic acid or their
acid halide derivatives.
Blends of linear and branched aromatic polycarbonates are
also included within the scope of this invention.
Other well known materials can also be employed for their
intended function and include such materials as anti-static
agents, mold release agents, thermal stabilizers, ultraviolet
light stabilizers, reinforcing fillers such as glass and other
inert fillers, foaming agents, and the like.
Accordingly, the high molecular weight aromatic polycarbon-
ates of the invention can be represented by the general formula
_ Xn
~kY ~ 11
- 0 ~ ~C) ~ 0 - C- _ (II)
Xm
wherein Xm, Xn, m, n, Y and R are the same as identified in
formula I above.
PREFERRED EMBODIMENT OF THE INVENTION
The following examples are set forth to more fully and
clearly illustrate the present invention and are intended to be,
and should be construed as being, exemplary and not limitative of
the invention. Unless otherwise stated, all parts and percentages
are by weight.
-- 6 --
r
~3~3~ ~CH-2582
In the following examples, the flame retardancy of the poly-
carbonates and copolycarbonates ob-tained was determined by feeding
the polycarbonates into an extruder which was operated at about
265C and the extrudates were each comminu-ted into pellets. The
pellets were then injection molded at abou-t 315C into test bars
of about 5 in. by 1/2 in. by about 1/16-1/8 in. thick. The test
bars (5 for each polycarbonate) were then subject to the test pro-
cedure set forth in Under~riters' Laboratories, Inc. Bulletin UL-
94, Burning Test for Classifying Materials. In accordance with
this test procedure, materials so investigated are rated either
V-0, V-I or V-II based on the results of 5 specimens. The
criteria for each V (for vertical) rating per UL-94 is briefly
as follows:
"V-0": Average flaming and/or glowing after removal of
the igniting flame shall not exceed 5 seconds
and none of the specimens shall drip flaming
particles which igni-te absorbent cotton.
"V-I": Average flaming and/or glowing after removal
of the igniting flame shali not exceed 25
seconds and the glowiny does not travel verti-
cally for more than 1/8" of the specimen after
flaming ceases and glowing is incapable of
igniting absorbent cotton.
"V-II": Average flame and/or glowing after removal of
the igniting flame shall not exceed 25 seconds
and the specimens drip flaming particles which
ignite absorbent cotton.
In addition, a test bar which continues to burn for more than 25
seconds after removal of the igniting flame is classified, not by
UL-94, but by the standards oE the instant invention, as "burns".
~J 7
, ~,
~3~ CH-25~2
Further, UL-94 requires that all test bars in each test group must
meet the V type rating to achieve the particular classi~ication.
Otherwise, the 5 bars recelve the rating o~ the worst single bar.
For example, if one bar is classified as V-II and the other four
(4) are classified as ~-0, then the rating for all would be V-II.
The moisture barrier properties for the polycarbonates and
copolycarbonates in the ensuing examples were determined using
Modern Controls, II1C . instruments. Water vapor transmission rate
(W~TR) measurements were obtained on an IRD-2C instrument pursuant
to ASTM F-372-73 and are based on infrared analysis.
The heat distortion temperature, i.e., heat distortion under
load (HDUL), for the polycarbonates and copolycarbonates obtained
was determined in accordance with ASTM-D-1637-61. The results
are expressed in degrees at a given pressure which, in each
instance, was 264 psi.
As is known to those skilled in the art, glass transition
temperature (Tg) can be used in place of ~DUL results as HDUL
results cannot be greater than Tg results. Where glass transi-
tion temperatures are given, they were de-termined using a Perkin~
Elmer DSC-2B instrument which measures the second order transi-
tion temperature by differential scanning calorimetry (DSC).
EXAMPLE 1
Preparation of 2,2'-Dichloro-4,4'-cyclohexylidenediphenol
Into a slurry o~ 268.3 parts by weight (1.0 partmole) 4,4'-
cyclohexylidenediphenol (BPC) in 3000 parts by weight methylene
chloride, that was being purged by a slow nitrogen stream, there
was introduced, at ambient temperature in the course of ca. 2
hours, 142 parts by weight (2.0 partmole) chlorine gas. In the
ensuing, mildly exothermic reaction, the refluxing solvent kept
t
3~ 8cH-2582
the reaction temperature between 40 and 45C. After the addition
of chlorine was completed, the colorless solution was sampled by
gas chromatographic analysls which showed the following
composition:
Retention Composition
Compound Time (Min) (Mole %)
4,4'~cyclohexylidenediphenol 19.57 0.1
2-chloro-4,4'-cyclohexylidenediphenol 20.82 5.6
2,2'-dichloro-4,4'-cyclohexylidenediphenol 23.15 92.1
2,2',6-trichloro-4,4'-cyclohexylidenedip~enol 25.27 2.2
Reference (4-cumylphenol) 12.36
Recrystallization from water-methanol yielded colorless
crystals of 2,2'-dichloro-4,4'cyclohexylidenediphenol (DCBPC),
99.6% pure, melting point 148.5-149.5C. Elemental analysis
confirmed the structure by matching its correct elemental
composition. Chlorine: found, 21.0; theoretical, 21.0%. Carbon:
found, 64.0; theoretical, 64.1%. HydrogenO found, 5.3; theoreti-
cal 5.4%.
EXA~PLE 2
~ aration of the Polycarbonate of 2,2'-Dichloro-4,4'-
-
cyclohexylidenediphenol (DCBPC)
Into a mixture of 84.3 parts by weigh-t of the highly pure
2,2'-dichloro-4,4'-cyclohexylidenediphenol (DCBPC) (0.25 partmole),
300 parts by volume water, 300 parts by volume methylene chloride,
0.47 parts by weight phenol, 0.5 part by weight triethylamine,
and 50% a~ueous NaOH solution to raise the pH -to 11.4, there was
introduced, at ambient temperature, 30 parts by weight phosgene in
30 minutes while maintaining the pH of the two phase system at
approximately 11 (between 10 and 12.5) by simultaneously adding
a 25% ~aOH solution. At the end of the addition period, the pH
g
'~;
~ 8CH~2582
of the aqueous phase was 11.7 and the diphenol content was less
than 1 part per million (ppm) as determined by ultraviolet analysis.
The methylene chloride phase was separated from -the aqueous phase,
washed with an excess of dilute aqueous hydrochloric acid (0.01
normal), and three times with deionized water. The polymer was
precipitated by adding the neutral and salt~free methylene
chloride solution to an excess of methanol and filtering off the
white polymer which was dried at 95C. The properties found for
the resultan~, pure DCBPC polycarbonate are set forth in the Table.
EXAMPLE 3
The procedure of Example 2 was repeated except that a mixture
of 75.9 parts by weight (0.225 partmole) 2,2'-dichloro 4,4'-
cyclohexylidenediphenol (DCBPC) and 5.7 parts by weight (Q.025
partmole) 4,4'-isopropylidenediphenol (BPA) was employed in place
of the highly pure 2,2'-dichloro-4,4'-cyclohexylidenediphenol
(DCBPC). The properties found for the resultant polycarbonate
are set forth in the Table.
EXAMPLE 4
The procedure of Example 2 was repeated except that a mixture
of 42.2 parts by weight (0.125 partmole) 2,2'-dichloro-4,4'-
cyclohexylidenediphenol and 33.5 parts by weight (0.125 partmole)
4,4'-cyclohexylidenediphenol (BPC) was used in place of the highly
pure DCBPC. The properties found for the resultant polycarbonate
are set forth in the Table.
EXAMPLE 5
Preparation of_4,4'~Cycloheptylidenediphenol
Into a solu-tion of 112.7 parts by weight (1.0 partmole)
cycloheptanone and 47Q parts by weight (5.0 partmole) phenol
there was introduced gaseous hydrobromic acid~ The mildly
-- 10 --
,.. .~ ~
/ ~?~.
3~ 8 C~I- 2 5 8 2
exothermic reac-tion was moderated by external cooling, keeping the
reactlon temperature between 30 and 37C. After ca. 1.5 hours of
reaction time, the red colored mixture thickened and solids began
to form. After an additional four hour contact with a slow stream
of hydrobromic acid, all acid was removed by placing the stirred
mixture under water aspirator vacuum and the solid phase removed
by vacuum filtration. Washing the solids with hot water and
recrystalli2ing them by charcoaling from aqueous menthol, yielded
white crystals of 4,4'-cycloheptylidenediphenol, melting point
208-209C, that were 99.1% pwre by gas chromatography analysis
(retention time: 25.35 min.; p-cumylphenol reference retention
time: 16.47 min.).
EXAMPLE 6
The procedure of Example 2 was repeated except -that 70.6
parts by weight 4,4'-cycloheptylidenediphenol was used in place of
the DCBPC. The properties found for the resultant polycarbonate
are set forth in the Table.
EXAMPLE 7
Preparation o~ a New Compound: 6,6'-Dichloro-4,4'-cyclo-
hex~lidenedi o-cresol
The procedure of Example 1 was repeated except that 4,4'-
cyclohexylidenediphenol was replaced with an e~uivalent amount of
4,4'~cyclohexylidenedi-o-cresol (296.4 parts by weight; 1.0 part-
mole), melting point 187-188C. Gas chromatography indicated the
following composition at the end of the reaction:
Retention Composition
Compound Time (Min) (Mole %)
__
4,4'-cyclohexylidenedi-o-cresol 22.72 0.6
6-chloro-4,4'-cyclohexylidenedi-o cresol 24.01 3.9
6,6'-dichloro-4,4'-cyclohexylidenedi-o-cresol 25.44 95.5
-- 11 --
.
/~
8CH~2$82
Retention Composltion
Compound Time (~in) (Mole ~)
Reference (p-cumylphenol) 14.93
Recrystallization from methanol-water yielded 6,6'-dichloro-
4,4'-cyclohexylidenedi-o-cresol in 98.8~ purity and a melting
point of 136.5-137.5C. Elemental analysis confirmed the com-
position. Carbon: found, 65.5i theoretical 65.8%. Chlorine:
found, 19.5; theoretical, 19.4%. Hydrogen: -Eound, 6.1;
theoretical, 6.1%.
EXAMPLE 8
The procedure of Example 2 was followed employing a mixture
of 45.6 parts by weight 6,6'-dichloro-4,4'-cyclohexylidenedi-o-
cresol (0.125 partmole) and 28.5 parts by weight 4,4'-isopropyli-
denediphenol (BPA) in place of 2,2'-dichloro-4,4'-cyclohexylidene-
diphenol. The properties found for the resultant copolycarbonate
are set forth in the Table.
EXAMPLE 9
The procedure of Example 1 was repeated except that only
71.0 parts by weight (1.0 partmole) chlorine gas instead of 2.0
partmole was employed. The resultant ternary mixture had the
followiny, nearly ideal, statistical composition as indicated by
gas chromatographic analysis:
Retention Composition
Diphenol Compound Time (Min)(Mole %)
4,4'-cyclohexylidenediphenol 19.61 26.2
2-chloro-4,4'-cyclohexylidenedlphenol 20.85 51.2
2,2'-dichloro-4,4'-cyclohexylidenediphenol 23.18 22.6
Reference (4-cumylphenol) 12.38
- 12 -
.q~
8CH-2582
EXAMPLE 10
The procedure of Example 2 was repeated except that the 2,2'-
dichloro-4,4'-cyclohexylidenediphenol was replaced with an equiva-
lent amount t75.7 parts by weight) of a statistical mixture
consisting of 26.2 rr.ole % BPC, 51.2 mole % 2-chloro-4,~'-cyclo-
hexylidenediphenol and 22.6 mole ~ DCBPC. The properties ~ound
for the resultan-t polycarbonate are set for-th in the Table~
EXA~I?LE 11
Preparation of a New Compound: 2,2'-Dibromo-4,4'-
Cyclohexylidenediphenol (DBBPC)
To a slurry of 268.3 parts by weight (1.0 partmole) 4,4'-
cyclohexylidenediphenol (BPC), 8000 parts by volume methylene
chloride and 1400 parts by volume water, there was simultaneously
added, at ambient temperature and with good stirring, a solukion
of 168.0 parts by weight sodium bicarbonate in 2500 parts by volu~e
water and 320.0 parts by weight liquid bromine. The addition
re~uired ca. one hour during which period the temperature of the
slurry rose from 22C to 28C and all oE the solids originally
present went into solution forming a light, cream colored, two
phase system. After separation from the a~ueous phase, gas
chromatographic analysis of the methylene phase lndicated the
following composition:
Retention Composition
Diphenol Compound Time (Min) (Mole %)
. . .
4,4'-cyclohexylidenediphenol 23.740.0
2-bromo-4,4l-cyclohexylidenediphenol 24.598.4
2,2'-dlbromo-4,4'-cyclohexylidenediphenol 26.34 83.8
2,2',6-tribromo-4,4'-cyclohexylidenediphenol 27.97 7.8
Reference (p-cumylphenol) 16.29
~ 3~ 8C~I 25~2
Recrystallization from methylene chloride yielded pure 2,2'-
dibromo-4,4'-c~clohexylidenediphenol as white cr~stals, melting
point 165-167C, with the correct elemental analysis. Bromine:
found, 37.46; theoretical, 37.51%. Carbon: found, 50.62;
theoretical 50.73%. Hydrogen: found, 2.80, theoretical, 2.77%.
EXAMPLE 12
The procedure of Example 3 was repeated except that D~BPC
was replaced wi-th an equivalent amount of DBBPC (95.9 parts by
weight, 0.225 partmole). ~'he properties found for the resultant
copolycarbonate are set forth in the Table.
EXAMPLE 13
Preparation of a New Compound: 6,6'-Dibromo-4,4'-
Cyclohexylidenedi-o-cresol
The procedure of Example 11 was repeated except that g,4'-
cyclohexylidenediphenol was replaced with an equivalent amount of
4,4'-cyclohexylidenedi-o-cresol (296.4 parts by weigh-t, 1.0 part
mole). Work up of the reaction mix-ture yielded white crystals for
which yas chromatography indicated -that i-t con-tained 96.3 mole %
of 6,6'-dibromo-4,4'-cyclohexylidenedi-o~cresol, re-tention -time:
25.57 minutes while -the reference, g-cumylphenol, emerged at
14.88 minutes.
Recrystallization from hexane yielded white crystals with a
59.5% purity and melting point of 137-138C. Elemental analysis
confirmed the structure. Bromine: found, 34.8; theoretical,
35.2%. Carbon: found, 52.8; theoretical, 52.9%. Hydrogen:
found, 4.8; theoretlcal, 4.9%.
EXAMPLE 14
The procedure of Example 3 was repeated except that the
DCBPC was replaced with an equivalen-t amount of 6,6'~dichloro-4,4'-
cyclohexylidenedi-o-cresol (113.5 parts by weight, 0.225 part-
- 14 -
~'
. ..
8CH~2582
3~
mole). The properties found for the resultant copolycarbonate are
set forth in the Table.
TABLE
Properties of Polycarbonates and Copolycarbonates
UL Rating
Example Specimen Thickness Tg HDUL
No. I~V. 1.56 mm 3.13 mm WVTR (C)(C @ 264 psi)
2 0.560 V-0 V-0 0.7~ 181161 - 163
3 0.566 V-0 V~0 2.2 - 158
4 0.522 V-0 V-0 3.1 156
6 0.526 V-II V-II 1.3 160
8 0.538 V-II V-0 4.7 - 145
0.582 V-~ V-0 3.0 - 1~9
12 0.506 V-0 V-0 1.67 - 159
14 0.522 4.7 - 156
As can be seen from the results tabulated above, the poly-
carbonates and copolycarbonates of the invention exhibit excellent
resistance to high heat distortion without adversely affecting
their other desirable properties. In addition to the resul-ts
shown in the above Table, the oxygen barrier properties of the
polycarbonates and copolycarbonates were also determined using an
OX-TRAN 100 instrument, the measurements obtained being based on
a coulometric method wherein the results are expressed in
cc/24 hrs./100 in2/mil/atmosphere. While all results were
acceptable, the oxygen transmission value obtained for the poly-
carbonate of Example 2 was exceptional at 6.5.
;~;
