CA1061923A - Flame retardant polycarbonate composition - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A flame retardant polycarbonate composition comprising an aromatic carbonatepolymer and as additive therefor an alkali or alkaline earth metal salt of either a monomeric or polymeric aromatic sulfonic acid, or mixtures thereof, when the aromatic carbonate polymer and additive each have a refractive index in a range of 1.54 to 1.65, non-opaque products result.

Description

~ 8CH-1946 .

This invention is directed to a flame retardant polycarbonate composition and in particular an aromatic pol~carbonate conta~ning in admixture therewith a particular flame retardant additive which may be the metal salts o~
either mono~eric or polymeric aromatic suLonates, or mLxtures thereof.
Wlth the increasing concern for safety, ~here is a positive move towards providing safe materials for public and household use. One particular area of need is that of providing flame resistant or flame retardant products for use by the ùltimate consumer. As a result of this demand, many products are being reguired to meet certain flame retardant criteria both by local and federal government and the manufacturers of such products. One particular set of conditions employed as a measuring standard for flame retardancy is set forth in Underwriters Laboratories, Inc. Bulletin 94. This Bulletin sets forth certain conditions by which materials are rated for self-extinguishing characterlstics.
In the art, there are many known flame retardant addi~ves which are employed by mixing with products to render such materials self-extinguishing or fla~e retardant. Such ~lame xetardant additives have been known to be employed in ; a~ounts of 5 to 20 weight percent in order to b0 e~fective in extinguishing burni~g of those products which are combustible.
It has also been found that such amounts can have a degrading effect upon tha base product to be rendered flame retardant, resulting in the losses of valuable physical properties o~
the base product. This is particularly so when employing known flame r~tardant additives with the base product polycarbonate resins. Many o* these known additives have a degrading effect upon the polymer.
It has now been surpri~ingly discovered t:hat an /

4~

aromatic polycarbonate can be made flame retardant by incorporatin~ with the aromatic polycarbonate minor amounts of certain additives, which additives are inert and do not degrade the aromatic polycarbonate. The particular additive employed herein is unique in that even very minor amounts render the aromatic polycarbonate ~lame retardant~ The amount o~
the additive employed herein can vary, preferably, from 0.01 to about 10 weight percent based on the weight of the aromatic polycarbonate.
More specifically, the particular additive of this invention is the metal salt of either the monomeric or poly-meric aromatic sulfonates or mixtures thereof. The metal salt employed in the practice of this invention is either the alkali metal or alkali earth metal salt and can include mixed metal salts. The metals of the~e groups are sodium, lithium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium and barium~
In the practice of this invention, the types of aromatic sulfonates employed herein may be either the monomeric form or the polymeric form or mixtures thereof. When first considering the monomeric form, the metal salt of the substituted monomeric aromatic sulfonate can best be represented by the following formula:
~A~ R~0-2 ~ I.

wherein ~ and L~ can, in turn, be independently selected ~rom the following formula:
~S03M)yR~ II.
wherein M is a metal which may be selected from the periodic table o either an alkali metal or an alkali earth metal, R' is an aryl radical of 1-4 aromatic rings, and y an integer of 0-10. It is to be understood, however, that in Formula I, there must be at least one ~1) S03M radicalO

~ 8CH-1946 In Formula I above, ~ is an organic radical of 1-20 carbon atoms and is either alkyl, aralkyl, alkenyl, aralkenyl, aryl, arylene, alkylene, aralXylene, alkenylene, aralkenylene, alkylidene, aralkylidene, alkenylidene or aralkenylideneO It should also be understood that ~R~ can contain halogen substitu-ents such as chlorine, bromine or fluorine.
As indicated above, Formula I, in its sL~plest form, can consist merely of ~B3 which in turn would be merely Formula XI with y being equal to 1. This is where LA~ and ~R~ would be zero (0). Thus, the simplest formula is a~ follows:

(S03M~

and more specifically S03Na Actually, while there are many compounds that meet the requirements of Formula I and which offer excellent flame retardant characteristics to an aromatic polycarbonatet the preferred additive employed in the monomeric form is disodium naphthalene-2,6-disulfona~eO This has the following formula:
so3~a NaO3S'~/

Mixtures of the metal salts of the monomeric aromatic sulfonic acids can be employed herein.
~hen the polymeric form of ~he aroma~ic sulfonate is employed in the practice of this invention, it can best be repxese~ted by the following formula:

æ~
rA ~ ~ ~ m~n rB~n }II.

wherein r~ and ~B3 are independently selected from khe following formula:
~ SO3M)yR~ IV.
wherein R', M, and y have the same meaning as recited previously. In addition, the same re~uirement for y is also applicable. However, it is also under~tood that ~ and ~BJ
units can be randomly selected. In addition, rRl~ LS an organic radical of 1-20 carbon atoms and is either arylene, alkylene, aralkylene, alkenylene, aralkenylene, alkylidene, aralkylidene, alkenylidane and aralkenylidene. In the polymeric form, ~R~
cannot be monovalent as in the case of the monomeric form of the additive employed herein and described by Formula I above.
In Formula III, the sum of m and n must be at least 4 and can be as high as 4000. As shown, the selection of m and n can be random or e~ual or one can be zero (0). In Formula III, R
can also contain halogen substituents as prevîously recited for [R~ of Formula I.
In the practice of thi~ invention, it is to be under~
~20 ~tood that the polymeric structure can be either a homopolymer, a copolymer, a random copolymer, a block copolymer or a random-block copolymer, including mlxtures thereo~. In addition, the ratio of sulfonated aromatic rings to unsulfonated aromatic rings can vary from greater than 1 to 1 to as high as that which is necessary to render the polycarbonate flame retardant.
This may be 1 to 100.
In order to more ~ully and clearly illu~trate the present invention, the following specific examples are presented.
It is lntended that the examples be considered as illustrative rather than limiting the invention disclosed and claimed herein.
In the examples, all parts and percentages are on a weight basie unless otherwise specified~

Example I
~ inety-nine (99) parts of an aromatic polycarbonate, p.repared rom 2,2-b.is~4-hydroxyphenyl)propane and pho~gene in the presence of an acid acceptor and a moIecular weight regulator and having an intrinsic viscosity of about 0.57, is mixed with 1 part of a finely ground dehydrated additive listed in Table I
by tumbling the ingredients together in a laboratory tumbler.
The resulting mixture is then ~ed to an extruder which is operated at aho~t 265C., and the extrudate is comminuted into pellets.
m e pellets are then injection molded at about 315 C.
into test bars of about 5" by 1/2" by about 1/16-1/8" thick.
The test bars (5 for each additive listed in the Table) are then evaluated in accordance with ~he test procedure of Underwriters' Laboratories, Inc., Pulletin UL-94, May, 1971, Burning Test for Classifying Materials. In accordance with the test procedure, material~ are classified as either SE-0, SE-I or SE-II. The results are based on 5 specimens. The critexia for SE rating per UL-94 is briefly as follows:
"SE-0": Average flaming and/or glowing after removal of the ignlting flame shall not exceed 5 seconds and none of the specimen3 shall drip flaming particle~ which ignite absorbent cottom~
"SE-I": Average flaming and/or glowing after removal of the igniting flame shall not exceed 25 seconds and the glowing does not travel ver-tically for more than 1/8" of the specimen after flaming ceases and glowing is incapable of igniting absorbent cotton.
"SE-II": Average flaming and/or glowing after removal of the igniting flame shall not exceed ~6~
25 seconds and khe 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 of the instant invention, as "burns". Further, UL-94 requires that all test bars in each test group must meet the SE type rating to achieve the particular classification~ Otherwise~ khe 5 bars receive the rating of the worst single bar. For example, if one bar is classified as SE-II and the other four (4) are classified as SE-O, then the rating for all 5 bars is SE-II.
The results of the different addi~ives within the scope of the instant invention are as follows with a control being the aromatic polycarbonate as prepared above without the additive of the type set forth herein.

I ~
.o o 5:L ~
bq ~rl ~a m ,1 ~
~ O
m ~ ~
~ 4~
Ul o~
3 ~J N

~ 0 HH 1-1 H H H H H H H H H
.,1 ~:: H H H H1~ 1 H H H 1-1 H
I'l Wli~ '1 W W W 1 ~; m tnU3 tn u~
~q P~ ~
In O OO O ~D ~ O ~ O
U~ ~ . . . . . . . . .
~1 ~ ~ ~ ~ D u7 ~ ~ o O E~
o P~
E3 ~
.~ o ~ O
O ~O ~ ~ ~ ~ ~ ~ ~ I~ In O _~
~ ~ . I
h 8 ,, ~
o o~
Q) al N ~1 ` I ~H
~) ~ ~ _I d' O
1~ 1 N~ 1 I h 8 o ~o ~ ~ ~
_ ~ ~
, ~ o U , .~ U

o ~, ,, ,, ,,~, o ~ ~ , U
Q ~ O S
~J ~ O O N N I~I-rl1~ O
~ ,~ ~ a. ~ O ~I q~
r~ o:~ ~ Q
3 ~ O O
~ l hr~
o ~ ~o I o o ~ E~l alN N h ~ ~Ql rlI
_I ~ O,s~ ) U
_ o a)(U~D Ql S~1 .) N R ~q ~ UUl ~U , ~ ~ O ~.rl ~1 r~O ~: O O t~O ,~O ~ O ~O r~
~ O ~ ~ 1 U ~ ) O O
~ u~ 4 C) ~'tS Cl ~ Cl~a a ~ P~ u~

~ U~
~ ,~ o a H

~ H H H

~ ~a "m ~1 0 N ~
O E-l O ,I r-l ~
h P .
~ ~ d' In E ol ~ 5 ~ ~ E
C~
,_ V ~ X
U
S ~ ~ In h I V
g O s~
r~l rl g r P ~ ~J ~ JJ ~ ~
1 ~ ~ ~ ~ ~ o .~ , _~ ~ ~ ~ ~ ~O
3 (_) J~ ~ ~D V ~ N . Q) ~ O
In ~ ~ ~ ~ 0 ~ ~ I
O ~ ~ ~ ~ ~ _l ~_ C,) ~ O ~ -~ O ~ . _ ~ O
_I ~ ~ ~ , ~ O ~I bq ~
_~ O U ~ I rl 1 ~ :~ O I ~ I ~O ~) ~ U3 r l ~ ~S
~o m~ ~ ~-,lo ~ "o ~ ~ ~o ~ ~l ~o ~
bq ~ ~ ~ ~n O ~ ~0 ~ 0 ~ O

~ O ~ I p ~-A OI ~ ~ 1 0 q:~ ~a ~ J 1~ a) a) u~ I la at o ~ ~ ~ 3 ~ ~ ~ 3 i' ~ 3 s~

~rl H H H
~ l l l W ~ E~l u~

~q rl tq 3~
U~ r~l N OD
~
O E~ N r-l r l O ~I) ~i ~
a~ - i ~ I O _I CO
rl a .
E~ ~

0~ I I ~
r l ID (~

N
r~
~, ~ rU~
l ,~ O ~
_ ~ ) ~ ~1 0 t~
r r l ~ r l a) r~l , tl~
~ I. : _' ~W U ~d U I_ I rl 3~ ~I r~l O IC
aJ ,~ ~ U~1 a) O q-l r~l S ~ s E3 r l ~ I ~ ~--~ o o ~ Q
r~ ~~~ O S l ~3 Ul r l t: ~ ~ U~ 0 ~ 3 ~ O
~1 ~ O ~ O
a) u u ~ o o ~ o o ~ , 3 U I ~"~

o O ,~ ~ o ~ ~1 . I ~ ~ O S~
~1 ~ i ~ ) ~1 ~ 1 ~ ri _ ~1 ~ ~ r l ~ S O ~ 1 0 _I ~
1~ y 3 rl O rl O ~ 0 ~ R
~ ~ ~ ~ E~
_~ ~ ~ ~ s~
,1 1 O ~ O ~,~ O ~n b'~ --, ri E3 0 ~ Id tQ ~ ~ a r 14 ¦ ~d 0 Il) U~ U 0 iDU~ Q) ~1 * e~ I 3 ~ n~ ~ 3 * Ql *
.

~ 3 8CH-1946 Ex~ample II
This Example is set ~orth to demonstrate the e~fect o~ the flame retardant additive~ of this :invention at the lower limit of 0.01 weight percent based on weight of the polymer composition.
In preparing the test bars for this Example, 99,99 parts of the polycarbonate of Examp:Le I are mixed with 0.01 weight percent of the additives listed in Table 2 employing the same mixing procedure. Test bars are th@n molded using the same molding conditions employed in Example I~ The test bars are subjected to the same test pxocedure of Example I with the following results;

~ 3 .Y

CJ
.,1 ~ H H H 1-1 tr; m cn cn tn cn ~q ~

IQ ~9 0 ~ ~9 q 7 O E~ ~r~
.
~ o~
~--~ ~D ~ ao o ~
~ ~ co ~ ~ o c) -~ ~u ~ u~

a~
~ ~ u~
_ ~ ~ rl O IU
~ o o o c~ ~
~ ~ ~ u u u~
a) .-1 ~ o p ~ ~~ ~ ~
~ o ~J ~J N N~ ~ ~ O
rl ~ O
3 ~ o Q, . E~~q ~ ~ ~--1 o ~ h ::~
_ N E3 1 ~
~ ,Q 0~ O
~ ~ u ~ ~
.,1 .,1 o o ~
~rl rlO U
tn ~ ~ 3 -~ 8CH-1946 Example III
This Example i9 set forth to show the e~fect of a known, commercially available flame retardant additive.
A.
Example I is repea~ed except that in place of the additives employed therein, only 1 part 1,2,5,6,9,10 hexabromo-cyclododecane is used herein. ~he results obtained upon evaluating ~ive (5) test bars are the same as obtained for the Control shown in Table 1 above.
B.
Part A. above i8 repeated but using 5 weight percent of the above additive, namely 1,2,5,6,9,10-hexabromocyclododecane~
The results obtained are the same as obtained ~n Part A. above.
C.
Part A. above is repeated but using 10 weight percent o~ the above additive, namely 1,2,5,6,9,10-hexabromocyclo-dodecane. At this level of additive, test bars are rated SE-II.
However, the polycarbonate is badly degraded as evidenced by severe dark streaking of the molded test bars, whi~h degradation does not occur with the additives o~ the instant invention.
Example IV
Example III is repeated except that hexabromobiphenyl is employed herein. The re~ults obtained are essentially the same as those of Example III.
Example V
Example III is repeated except that the additive ~-~ employed herein is a combination of antimony oxide and a material which is a mixture of polychlorinated hiphenyl (Aroclo by Monsanto Company)~ m e proportion of the ingredients of the additive, employed in this example is based on 3 parts of chloxine per 1 part of antimony~ ~he results obtained at 1 weight percent and S weight percent amounts axe the sa~e as in Examine III.
However, at the higher amount, namely 10 weight percent, flame retardancy effect is noted but with, again, severe degradation of the polycarbonate, a~ evidenced by the substantial reduction ~n the intrinsic viscosity of the molded test bars. As molded, the intrinsic viscosity of the test bars with 1 weight percent of the above additive is about 0O50.
The intrinsic viscosity of the molded test bars containing 10 weight percent of the flame retardant additive of this Example is 0.253. This shows the severe degradation of the polycarbonate w~en employing this type of well known flame retardant.
In the practice o~ this invention, aromatic carbonate polymers are rendered flame retardant by the addition of certain particular additives which are the metal salt~ of monomeric or polymeric aromatic sulfonic acids or mixtures thereof. The amount of the additives employed in the practice of this invention may vary from 0.01 to up to that amount which after further increasing does not material increase the flame retardant properties of the polycarbonate~ This is generally up to about 10 weight percent basad on the weight o~ the aromatic carbonate polymer but may be higher. The amount of the additive to be employed can also be a function of the degree of flame retardancy desired.
~t is not exactly understood how the additive of this invention functions ox how such minor amounts can act as an effective flame retardant fox the aromatic carbonate polymer~
Analysis of the composition of this invention after being subjected to a fire temperature of about 600C. shows an unusually high percentage of remaining char. This leads one to hypothesize that the additive may act as a cross~linking agent when the aromatic carbonate polymer is subjected to fire temperatures. However, it is emphasiæed that this is only theory and should not be construed as actually occurring.
As indicated previously, the aclditive of the instant invention comprises the alkali or alkali earth metal salts of the monomeric or polymeric arom~tic sulfonic acids and includes mixtures thereoE. While a great number of such salts are set forth in the tables of the Examples of the instant invention, these are only a representative sample of the additives o~
this invention. The sodium, calcium, magnesium, potassium, strontium, lithium, barium, rubidium and cesium salts of other aromatic sulfonic acid can be employed ~n place of thsse of the E~amples with the same effective flame retardancy being achieved. ~he~e other aromatic sulfonates are:
meta-benzenedisulfonic acid, disodium salt para-benzenedisulfonic acid, dipotassium salt 1,3,5-benzenetrisulfonic acid~ trisodium salt biphenyl-4-sulonic acid, calcium salt naphthalene-l-sulonic acid, barium salt xylene sulfonate, sodium salt naphthalene-2-~ulfonic acid, strontium salt naphthalene-2,7~disulfonic acid, disodium salt naphthalene-1,4,7-trisulfonic acid, trisodium salt anthracene-2,6-disulfonic acid, sodium-potassium salt phenanthrene-l-sulfonic acid, magnesium salt pyrene-1,3,6,8-tetrasulfonic acid, tetrasodium salt diphenylmethane-4-sulonic acid, calcium salt 1,1-diphenylethane-4,4'-disulfonic acid, disodium salt

2,2-dichloro-1,1-diphenylethylene-4',4''-disulfonic acid, disodium salt triphenylmethane-4,4',4''-trisulfonic acicl, trisodium salt 1,1,2,2-tetraphenylethane-4,4l,4'',4'''-tetrasulfonic acid, tetrapotassium salt 1uorenedisulfonic acid, dilithium salt - 14 ~-~ ~ 8CH-1946 9,1Q-dihydroanthracene-2,7~disulfonic acid, disodium slat sulfonated polybenzyl, polysodium salt sulfonated polystyrene, polysodLum salt sulfonated polystyrene (crosslillked with divinyl-benzene), polysodium salt sul~onated polybiphenyl, polysodium-potassium salt sulfonated poly ~ di(biphenyl)ethane~, polysodium salt In the practice of this invention, the additive i9 generally prepared ~y well known methods in the art. For example, one such well known method involves taking an aromatic hydrocarbon such as benzene and contacting it with either sul-furic acid, chlorosulfonic acid, uming sulfonic acid or sulfur trioxide. These reactions can be carried out at room temperature or at elevated temperatures such as about 50C. The salt is then prepared by adding the proper alkaline reagent in suffi~ient amount to make the neutral salt. me salt is then recovered by precipitation or by distillation of the solvent.
In the practice of this invention, any of the aromatic polycarbonates can be employed herein. However, particularly useful are the aromatic polycarbonates prepared by reactîng a dihydric phenol, such as bisphenol-A, (2,2'bis(4 hydroxyphenyl) propane) with a carbonate precursor. Typical of svme of the dihydric phenols that may be employed in the practice of this invention are bis(4-hydroxy-3-methylphenyl)propane, 4,4-bis~4-hydroxyphenyl)heptane, 2,2-(3,5,3',5'-tetrachloro-4,4 t -dihydroxy-diphenyl~propane, 2, 2Q ( 3,5,3',5'-tetrabromo-4,41-dihydroxy-diphenyl)propane, (3,3'-dichloro-4,4~-dihydroxyd iphenyl~methane.
Other dihydric phenols of the bisphenol type ara also available and are disclosed in U.S. patents 2,999,835 - Goldberg, issued Septemberl2, 1961; 3,028,365 - Schnell et al, issued April 3, 19627 and 3,334,154 - Kim, issued August 1, 1967.
In addition, the reaction is carried out with the ~ 15 -~ 8CH-1946 carbonate precur~or in the presence of a molecular weight regulator an acid acceptor and a catalyst. The pre~erred car-bonate precursor generally employed in preparing carbonate polymers is carbonyl chloride. However, other carbonate precursors may be employed and this inclucles other carbonyl halides, carbonate esters or haloformates~
The acid acceptors, molecular weight regulators and catalysts employed in the process of preparing polycarbonates are well known in the art and may be any of those commonly used to prepare polycarbonates.
As indicated previously, the additive employed herein can consist of mixtures of the metal salt~. These mixtures can be mlxtures of the various metal salts of the monomeric aromatic sulfonic acid or mLxtures of the various metal salts of the polymeric aromatic sulfonic acids or mixtures of the metal salts of the monomeric and the polymeric aromatic sulfonic acids. ~he mixtures have provided certain advantages such as SE-0 rating of 5 test bars and essentially ~ero number of drips per test bar.
It will thus be seen that the objects set forth above among those made apparent from the preceding description are efficiently attained and since certain changes may be made in carrying out the above process and in the composition set forth without departing from the scope of this invention, it is intended that all matters contained in the above description shall be interpreted as illustrative and not in a limiting sense.

6C~9~6 SUPPLEL~EMT~RY DISCLO~SURE
In the principal disclosure of my invention thers are described novel Elame retardant compositions comprising' aromatic carbonate polymer~ in ad~i~t~re with from about 0.01 to about 10 par-ts by weight per hunclred par-ts of th2 polymer of an additive comprising yiven metal salts of a sulfonic acid of a defined class~
It has further been found that such additive may be effective for the above stated purpose when present in a concentration of as little as 0~001 parts per hundred parts of the polyrner.
It has still f~lrther been found that when the additive as defined earlier has a refractive index in the same range as that of the aromatic carbonate polymer ie.
about 1.54 to 1,65, the aforesaid compositions wherein the additive is present in about 0.001 to about 2 parts per hundred parts of aromatic carbonate poly-rner are not onLy flame retardant but are also non-opa~ue.
,- ~ i By non-opaque i5 meant that the polycarbonate compositions and shaped articles produced therefrom ~hich may be in the form o~ sheet, for example, or merely in the form of pellets suitable for extrusion, are able to transmit light. The compositions ma~ vary from translucent to transparent, depending upon the closeness of the refractive index of the additive to that o~ the aromatic carbonate polymer.
If the additive at the concentration employed is partially or totally soluble in the carbonate polyrner, the transpare~cy of compo3ition and article will n~turally be increased, The refractive indices of the materials herein described are determined ~y the immersion method a3 shown in Physical ~ethods of Organic Chemistry (Weissberger Interscience Publishers, Vol. I~, 1960, p 1~33).

~ 8CH-~46 Interscience Publishers, Vol II, 1960, p L433).
A preferred additive for the formula~ion of non-opaque products which confers excellent fLame retardency is disodium naphthalene 2,6 disulfonate NaS03 /~

The non-opaque flame retardent compositioTIs which comprise this additional aspect of my invention may further comprise other additives which are commonly employed in the formulation of non-opaque aromatic carbonate polymer products, for example pigments, dyes, antioxidants, stabilizers, U~ V.
light absorbers, mold release agents etc~
In order to illustrate the present invention more fuLly and clearly, both in its general aspect in providing flame retardent compositions and also in the more specific and newly disclosed aspect in providing non-opaque flame retardent compositions, the following additional examples are presented. All parts and percentages are expressed upon a weight basis unless otherwise specified. The examples are not to be considered as limiting the scope of the invention, this being elsewhere defined, Example VI
One hundred parts of the aromatic polycarbonates as in example 1 is mixed with 0.01 part of a finely ground dehydrated additive as listed in table 3. Test bars prepared as in example l are subjected to the UL 94 Burning Test, with the bars oriented in the vertical position. The results are classified into 3 grades, V-0 - VII, the criteria for the grades being essentially the same as for those earier given for the corresponding SE grades~
me test squares are tested for light transmission in a Gardner XL 10-CDM instrument. The data shows the amount of 106 ~ 8CH~9~6 incident light transmitted by the test s~uares using air as 100% transmission.
The result o an additive withi.n the scope o~ the .instant invention is as follows with a control being the S aroma~ic polycarbQnate as prepared above without the additive o the type set ~orth herein~

' , :

~3CEI~946 d1 ~
~n ~ .,~
I ~ ~: H H
~ m .Q,~

4~ a) _1 o:~
~oi s~
.~

o o ~9 O N

1i3 O

, .,1 ~q ~
~@
E~

I ~ ~

3~ o ~u .
,, to I ~ ~
,~
a~ , ~ `
tQ ~ I
5~ ~ ~
~1 o ~ ~
C .~ .~
a U~
. , o ~ ~ rl O
~ ~i ~ ~
~ 8 1! l r ~
- 20 ~

.~ 8CH1946 ~L~ L~
F~MP~E VXI
-This Example is set forth to demonstrate the effect of the additives o thi~ invention at limits of 0.10 parts per hundred parts of the polycarbonate.
In preparing the test specimens for this Example, 100.00 parts of the polycarbona~e of Example I is mixed with 0.10 parts o~ the additives listed in Table 4 employîng the same procedure, Test specimens are then moldea using the same procedure employed in Example I. The test specimens are subjected to the same test procedure of Example VI with the following results:
Table 4 - 2~ -~CEI-19~6 ., rl I ~J S-l H H
m P P
I

~q ~rl W
5~ ~
o o a~ _I
o P
O q~
~s~
G) . .~
~Q
~ ~ ~ CD
o o a~
~U~
~I

o ,, IQ

-1 h $ ~ ~
-I ~
_ ~ ~ O
1 3 ~ ~
I ~ ~
S~ , ~0 I
~ O ::~
I
~ 1~ ~1 0 In a~ o I ~ ~I-rl C
_ .
~rl ~ q u C~
i rl O V-rl f ~ Q

8CH-~46 EX~MæLE V~III
m is example is set forth to demonstrate the efect of the additive~ of this invention at limits of 0.20 parts per hundred parts of the polycarbonate.
In preparing the test specimens for this Example, 100.00 parts of t~e polycarbonate of Exam~le I is mi~ed with 0~20 parts of the additives listed in Table 5 employing the same procedure. Test specimens axe then molded using the same procedure employed in Exanple I. The test specimens are subjected to the same test procedure of Example VI with the following re~ults:
Table 5 8cH-l946 ~ .~
L ¦ ~1 o H H H
!~ I m ~q~
o o o o ~, op P~

'E~
~n a~
, .
I ~ ~ U~
o I

~ .
r~
U~ ~ bq ,~ ~ o ~ ~ ao :~ ~ ~ ~:
i Q) ^
~Q

Q ~ o _ la ~ o ,, Ul O
s~
~ -I ~ 0 a Q ~ N
u~

O

.
,l ~ ~ o ~ z ~ ~ ~ ~
o Q ..
V U~

. .

8CHi94 6 EXAMPLE IX
This example i5 set forth to demonstrate the ef~ect of ~he additives of this invention at limits of 0~50 parts per hundred parts of the polycarbonate.
In preparing the test specimens ~or this Example, 100.00 parts of the polycarbonate of Example I is mixed with 0.50 parts of the additives listed in Table 6 employing the same procedure. Test specimens are then molded using the same procedure employed in Example I. The test specimens are subjected to the same test procedure of Example VI with the following results:
Table 6 ~,~

- 25 ~

8CH~946 ,~
~- I
I ~ ~ O H H
!~1 p~ m s~

s~ a) o o o o ~
.
h .~
E~
~ O ~9 ~ U~
O U N
~ Cq _l ~D O

O) O Ct) m ~ ~ ~ a~
~i E~
_ I
I
I ~ ~ I
I ~ ~ a I o o ,~
I ~ ~ ~
h ~
r~ 3 ~:s ~q ;n _I
a~
I
N N ,~:
~_ 5 ¦ , ~ R .Q
. I ~1 ~rl rl I
o o ~ o I ~ u~ m u~

~ 8CH~46 In the practice of this invention, aromat~c carbonate polymers are renderad flame retardant by the addition of certain particular additives which are the metal salts of mon~meric or pol~meric aromatic-sulfonic acids or mi~tures thereof~ The amount of the additives employed in the practice of this invention may vary from 0.001 to up to about 10 parts per hundred parts of aromatic polycarbonate.
As indicated previously, the additive of the additional aspect of the instant invention comprise~ the alkali or alkali earth metal salts of t~e monomeric or polymeric aromatic sulfonic acids and includes mixtures thereof having a refractive index in the range of 1.54 to 1.65. While a great number of such salts are set forth in the tables of the Examples of the instant invention, these are only a representative ~ample of the additives of this invention. The sodium, calcium, magne~ium, potassium, strontium, lithium~ barium, rubidium and cesium salts of other aromatic sulfonic aci~s can be empl~yed - in place of those of the Examples with the same effective ome ~ ~ ~lame retardancy being achieved. ~k~s~ other aromatic sulfonates are:
meta-benzenedisulfonic acid, disodium salt para-benzenedisulfonic acid, dipotassium salt 1,3,5-benzenetrisulfonic acid, trisodium salt biphenyl-4-sulfonic acid, calcium salt naphthalene-l-sul~onic acid, barium salt xylene sulfonate, sodium salt naphthalene-2-sulfonic acid, strontium salt naphthalene-2,7-disulfonic acid, disodium salt naphthalene-1,4,7-trisulfonic acid, trisodium salt anthracene-2,6-disulfonic acid, sodium-potassium salt phenanthrene-l-sulfonic acid, magnesium salt pyrene~l,3,6,8-tetrasulfonic acid, tetrasodium salt diphenylmethane-4-sulfonic acid, calcium salt .~

8CHi946 ~g~
1,1-diphenylethane-4,4'-disul~onic acid, disodium salt 2,2-dichloro-1,1-diphenylethylene-4',4"-disulfonic acid, disodium salt triphenylmethane-4,4'~4"-trisulfonic acidi tr;~odium salt 1,1,2,2-tetraphenylethane-4,4',4",4"'~tetrasulfonic acid, tetrapotassium ~alt fluorenedisulfonic acid, dilithium salt 9,10-dihydroant~race~e-2,7-disulfonic acid, disodium salt sulfonated polybenzyl, polysodium salt sulfonated polystyrene, polysodium salt sulfonated polystyrene ~crosslinked with divi~ylbenzene), polysodium salt sulfonated polybiphenyl, polysodium-potassium salt sulfonated poly[l,l-di(biphenyl)ethane~, polysodium ~alt In the practice of this invention, any of the aromatic polycarbonates can be employed herein having a re~ractiva index in the range of 1.54 to 1.65. These are homopolymers and copolymers and mixtures thereof that are prepared by reacting a dihydric phenol with a carbonate precursor.
It is, of course, possible to employ two or more dif~erent dihydric phenols or a copolymer of a dihydric p~enol with a glycol or with hydroxy or acid terminated polye~ter, or with a dibasic acid in the event a carbonate copolymer or interpolymer rather tha~ a homopolymer is desired for u9e in ~he preparation of the aromatic carbonate polymers of ~his invention. Also employed in the practice of this invention may be blends of any of the above materials to provide the aromatic carbonate polymer.
The carbonate precursor may be either a carbonyl halide, a carbonate ester or a haloformate. The carbollyl ~ CH~46 halides which can be employed herein are carbonyl bromide, carbonyl chloride and mixtures thereof~ Typical o~
the carbonate esters which may be employed herein are diphenyl carbonata, di-(halophenyl) carbQnates such as di-(chloro-phenyl) carbonate, di-(bromophenyl) carbonate, di-(trichloro-phenyl) carbonate, di-~tribromophenyl) carbonate, etc., di-(alkylphenyl~ carbonate such as di(tolyl) carbonate, etc., di-(naphthyl) carbonate, di-~chl~ronaphthyl) carbonate, phenyl tolyl carbonate, chlorophenyl chloronaphthyl carbonate, etc~, or mLxtures thereof. m e halo~ormates ~uitable for use herein include bis-haloformates of dihydric phenols (bischloroformates 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 aci~ and carbonic acid.
The aromatic carbonate polymers of this invention may be prepared by employing a molecular weight regulator; an acid acceptor and a catalyst. The molesular weight regulators which can be employed in carrying out the process of this invention include monohydric phenols such as phenol, chroman-I, paratertiary-butylphenol, parabromophenol, primary and secondary amines, etc. Preferably, phenol is employed a~ the molecular weight regulator~
A suitable acid acceptor may be either an organic or an inorganic acid acceptor. A suitable organic acid acceptor.
A suitable organic acid acceptor is a tertiary amine and includes such material3 as pyridine, triethylamineO climethyl-aniline, tributylamine, etc. The inorganic acid acceptor may be one which can be either a hydroxide, a carbonate, a bicarbonate, or a phosphate of an alkali or alkaline earth metal.
The catalyst~ which are employed herein can be any of . .
_ ~9 _ ~c~9~

the suitable catalysts that aid the polymerization of bisphenol-A with phosgene. Suitable catalysts include tertiary amines such as for example, triethylamine, triprlopylamine, N,N-dimethyl-aniline, quaternary ammonium compounds such as for example tetraethylammonium bromide, cetyl triathyl ammonium bromide, tetra-n-hyptylammonium iodide, tetra-n-propyl ammonium bromide, tetramethylammonium chloride, tetramethyl ammonium hydroxide, tetra-n-butyl-ammonium iodide, benzyltrimethylammonium chloride and quaternary phosphonium compounds such as for example, n-butyltriphenyl phosphonium bromide and methyltriphenyl phosphoniu~ bromide.
Also, included herein are branched polycarbonates wherein a polyfunctional aromatic compound is reacted with the dihydric phenol and carbonate precursor to provide a thermo-plastic randomly branched polycarbonate.
These polyfunctional aromatic compounds contain at least three functional groups which are carboxyl, carbioxylic anhydride, haloformyl or mixtures thereof. Examples of these polyfunctional aromatic compounds which may be employed in the practice of this invention include: trimellitic anhydride, trimellitic acid, trimellityl trichloride, 4-chloroformyl phthalic anhydride, pyromellitic acid, pyromellitic dianhydride, mellitic acid, mellitic anhydride, trimesic acid, benzophenone-tetracarboxylic acid, benzophenonetetracarboxylic anhydride and the like. The preferred po~yfunctional aromatic compounds are trimellitic anhydride or trimellitic acid, or their haloformyl derivatives.
Also, included herein are blends of a linear poly carbonate and a branched polycarbonate.

As indicated previously, the additive employed herein can consist of mixture of the metal salts~ These mixtures can be mixtures of the various metal salts of the monomeric ~ 8CHi946 aromatic sulfonic acid or mixtures o~ the various metal ~alts o~ the polymeric ar~matic sulfonic acids or mixtures of the metal salts o the monomeric and the polymeric aromatic sulfonic acids. The mixtures have provided certain advantages ~uch as V-O
rating of 5 test bars and es~entially ~ero number of drips per test bar.
It will thus be sean that the objects set ~orth above amvng those made apparent from ths preceaing description are efficiently attained and since certain changes may be made in carrying out the above process and in the composition set forth w~thout departing from the scope of this invention, it is intended that all matters contained in the above description shall be interpreted as illustrative and not in a limiting sense.

Claims (15)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. A flame retardant carbonate polymer composition comprising in admixture an aromatic carbonate polymer and a minor flame retardant amount of an additive selected from the group consisting of the metal salt of a monomeric aromatic sulfonic acid and a polymeric aromatic sulfonic acid and mixture thereof, wherein said metal salts thereof are selected from the group consisting of the alkali metal salts and the alkaline earth metal salts and mixtures thereof.

2. The composition of claim 1 wherein the composition comprises in admixture 0.01 to about 10 weight percent of the additive based on the weight of the aromatic carbonate polymer composition.

3. The composition of claim 1 wherein the metal salt of the monomeric aromatic sulfonic acid has the following formula:
[A]0-1[R]0-2[B]
wherein R is selected from the group of organic radicals consisting of halogen substituted alkyl, aralkyl, alkaryl, aralkenyl, alkylidene, aralkylidene, alkenylidene and aralkenyli-dene radicals of 1-20 carbon atoms and wherein A and B are independently selected from the following formula:
(SO3M)yR' wherein M is a metal selected from the group consisting of alkali metal and alkaline earth metal, R' is an aryl radical of 1-4 aromatic rings and y is an integer of 0-10, provided that the sum of y must equal at least 1, and when there is no R group present the R' radicals of [A] and [B] are directly linked.

4. The composition of claim 3 wherein R in the formula is trichloroethylidene and there is one [A] group in said formula.

5. The composition of claim 3 wherein the formula R is trichloroethylidene, there is one [A] group, [A] and [B]
each have the formula C6H4SO3Na.

6. The composition of claim 3 wherein the additive is as follows:

.

7. The composition of claim 3 wherein the additive is calcium benzene sulfonate.

8. The composition of claim 1 wherein the metal salt of the polymeric aromatic sulfonic acid has the following formula:

[A]m [R1]m+n[B]n wherein R1 is selected rom the group of organic radicals consist-ing of halogen substituted and unsubstituted arylene, alkylene, aralkylene, alkenylene, aralkenylene, alkylidene, aralkylidene, alkenylidene and aralkenylidene radicals of 1-20 carbon atoms and wherein A and B are independently selected from the following formula: (SI3M)yR' wherein M is a metal selected from the group consisting of alkali metal and alkaline earth metal, R' is an aryl radical of 1-4 aromatic rings, y is an integer of 0-10, provided that the sum of y must equal at least 1, and further wherein m is an integer of from 0 to 2000, n is an integer of from 0-2000, provided, however, that the sum of m and n must equal at least 4.

9. The composition of claim 8 wherein the additive is the polysodium salt of polystyrene polysulfonic acid.

10. The composition of claim 8 wherein the additive is as follows:

CLAIMS SUPPORTED BY THE SUPPLEMENTARY DISCLOSURE

11. A non-opaque flame retardant carbonate polymer composition comprising in admixture an aromatic carbonate polymer and from 0.001 to about 2.0 parts per hundred parts of the aromatic carbonate polymer of an additive selected from the group consisting of the metal salt of the monomeric aromatic sulfonic acid and polymeric aromatic sulfonic acid and mixtures thereof, wherein said metal salts thereof are selected from the group con-sisting of the alkali metal salts and the alkaline earth metal salts and mixtures thereof; said aromatic carbonate polymer and additive having a refractive index in the range of 1.54 to 1.65.

12. The composition of claim 11 wherein the metal salt of the monomeric aroma-tic sulfonic acid has the following formula: [A]0-1[R]0-2[B]
wherein R is selected from the group of organic radicals consist-ing of halogen substituted and unsubstituted alkyl, aralkyl, alkenyl, aralkenyl, alkylene, alkylidene, aralkylidene, alkenyli-dene and aralkenylidene radicals of 1-20 carbon atoms and wherein A and B are independently selected from the following formula:
(SO3M)yR' wherein M is a metal selected from the group consisting of an alkali metal and alkaline earth metal, R' is an aryl radical of 1-4 aromatic rings and y is an integer of 0-10, provided that the sum of y must equal at least 1 and when there is no R group present the R' radicals of the [A] and [B] groups are directly linked.

13. The composition of claim 12 wherein in the formula R is trichloroethylidene, there is one said [A] group, and [A]
and [B] each have the formula -C6H4SO3Na.

14. The composition of claim 12 wherein the metal salt is as follows:

15. The composition of claim 3 wherein the metal salt is selected from potassium benzene sulfonate, sodium benzene sulfonate, and potassium p-toluene sulfonate.