Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~ f3~ 8CH-29~3
This invention relates to thermally stable polycarbonate
compositions comprisiny an admixture of an aromatic polycarbonate
and a stabiliæing amount of a hindered phenol phosphite.
BACKGROUND OF THE INVENTION
In the past, much effort has been expended in preparing
I thermally stable polycarbonate compositions which would be color
stable at elevated temperatures and particularly at the high
molding temperatures generally employed to prepare molded
polycarbonate articles. Many different additives have been found
that the quite suitable for rendering polycarbonates heat and
color stable. Particularly useful are triorgano phosphites such
as are disclosed in U.S. Patent 3,305,520 - Fritz et al, issued
February 21, 1967. In addition, U.S. Patent 3,729,440 - Liberti,
issued April 24, 1973 and U.S. Patent 3,953,338 - Straus et al,
issued April 27, 1976 disclose thermally stable aromatic poly-
carbonates containing a phosphinite and an epoxy compound.
Further, U.S. Patent 3,794,629 ~ Eimers et al, issued February 26,
1974 discloses chemically stable aromatic polycarbonates
containing oxetane phosphites and U.S. Patent 3,978,020 - Liberti,
issued August 31, 1976 discloses thermally stable aromatic poly-
carbonates containing phosphonites which include epoxy compounds.
Polycarbonates are also used for producing bottles; however,
these bottles become hazy after sterilization in water or exposure
to moisture at elevated temperatures. U.S. Patent 3,839,247
Bialous et al, issued October 1, 1974 discloses a water clear
polycarbonate composition which can be used to mold bottles twherein the polycarbonate composition contains an aromatic epoxy
or an aliphatic epoxy compound as a stabilizer.
Canadian application Serial No. 343,169, Markezich, filed
January 7, 1980, discloses aromatic polycarbonate compositions
containing phosphonite oxetanes; Canadian application Serial
No. 343,194, Markezich, filed 3anuary 7, 1980, discloses aromatic
~ ' ~
-- 1 --
:
~ 6S1 8CH-2963
polycarbonate compositions containing phosphite oxetanes having
a hindered phenol; Canadian application Serial No. 343,122,
Markezich, filed January 7, 1980, discloses aromatic polycarbonate
compositions containing a phosphonite or a phosphonite oxetane
each having a hindered phenol; and, Canadian application Serial
No. 343,170, Markezich, filed January 7, 1980, discloses aromatic
polycarbonate compositions containing dioxane phosphites, each
of these Canadian applications being assigned to the same
assignee as this case.
DESCRIPTION OF THE INVENTION
It has been discovered that when an aromatic polycarbonate
is admixed with a hindered phenol phosphite, the resulting poly-
carbonate composition has improved thermal stability as exempli-
fied by its resistance to yellowing when subjected to high molding
temperatures.
The phosphite compounds that can be used in the present
invention are represented by -the general structure:
A ~ 0 ~ I _ (0Rl) (I)
( ORl)
wherein Rl can be an alkyl of Cl to C30, an aryl of C6 up to about
C30, preferably C6-C12, and alkyls of C~ to C20 which can form
mono-cyclic structures; and, A is a hindered phenol represented
by the general structure:
; 3 ~ (II)
~4
wherein R2, R3 and R4 can be the same or different and each can
independently be hydrogen, halogen or Cl-C4 alkyl provided that
neither R2 and/or R4 are hydrogen.
~3~5~ 8CH-2963
!
Ij Thus, Rl in formula I can be unsubstituted and halogen
I ~substituted alkyl, aryl, cycloalkyl, aralkyl and alkaryl radicals ~
of about Cl-C30 so that typical phosphites that can be employed ¦
'~in the present invention are those wherein Rl can be alkyl
5¦ such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl,
tertiary butyl, n-amyl, isoamyl, tertiary amyl, n-hexyl, dodecyl,
nonyl, and the like; cycloalkyl such as cyclohe~yl, 2-methyl-
, cyclohexyl, 4-methylcyclohexyl, 2-ethylcyclohexyl, 4-ethylcyclo-
¦ihexyl, 4-isopropylcyclohexyl, and the like; aryl such as phenyl,
10¦¦naphthyl, 2-naphthyl, biphenyl of terphenyl, and the like;
aralkyl such as benzyl, phenylethyl, 2-phenylethyl, l-phenylpropyl
,2-phenylpropyl, and the like; alkaryl such as p-tolyl, m-tolyl,
j2,6-xylyl, o-tolyl, p-cumyl, m-cumyl, o-cymyl, mesityl, p-
! tertiary butylphenyl, and the like; and, haloaryl such as 2-
15 tl chlorophenyl, 2,4,6-trichlorophenyl, 2,4,6-tribromophenyl, and
llthe like, wherein the substituted portions thereof can be halogen
!~ atoms.
The phosphites of the.invention can be prepared by methods
,iknown to those skilled in the art such as are described in
20~lOrganic Phosphorous Compounds, Vol. 4, edited by G.M. Kosolapoff
and L. Maier (1972), pages 255-462,. ~ - --
¦~ The.phosphite compounds of the invention are admixed with¦¦the aromatic polycarbonate in a stabilizing amount which is
25 ¦¦ generally on the order of about 0.005 1.0, preferably 0.01-
¦,0.50 and optimumly about 0.02-0.20 weight percent, based
1~ 1
I i
i'~
~ - 3
~3~ 8CH-2963
i~ ' i
upon the weight of the aromatic polycarbonate.
The aromatic polycarbonate that can be employed in the prac-
tice of this invention are homopolymers and copolymers and mix-
Itures thereof that are prepared by reacting a dihydric phenol
with a carbonate precursor.
The dihydric phenols that ~an be employed are bisphenols such
as bist4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane
(bisphenol-A), 2,2-bis(4-hydroxy-3-methylphenyl)propane. 4,4-
,!bis(4-hydroxyphenyl)heptane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl)
10 jlpropane~ 2,2-bis(4-hydroxy-3,5- dibromophenyl)propane, etc.;
¦dihydric phenol ethers such as bis(4-hydroxyphenyl)ether, bis(3,5-
jldichloro-4-hydroxyphenyl)ether~ etc.; dihydroxydiphenyls such
Il as p,p'-dihydroxydiphenyl, 3,3'-dichloro-4,4-dihydroxydiphenyl,
¦letc.; dihydroxyaryl sulfones such as bis(4-hydroxyphenyl)sulfone,
15 ¦I bis(3,5-dimethyl-4-hydroxyphenyl)sulfone, etc.; dihydroxy
3 benzenes, resorcinol, hydroquinone, halo- and alkyl-substituted
¦ dihydroxybenzenes such as 1,4-dihydroxy-2,5-dichlorobenzene,
1,4-dihydroxy-3-methylbenzene, etc.; and dihydroxy diphenyl
sulfoxides such as bis(4-hydroxyphenyl)sulfoxide, bis(3,5 dibromo-¦
20 ~ 4-hydroxyphenyl)sulfoxide, etc. A variety of additional dihydric ¦
¦ phenols are also available to provide carbonate polymers such as
3 are disclosed in U.S. Patents 2,999,835, 3,023,365 and 3,153,008.
Also suitable for preparing the aromatic carbonate polymers are
copolymers prepared from the above dihydric phenols copolymerized
with halogen-containing dihydric phenols such as 2,2-bis(3,5-
dichloro-4-hydroxyphenyl)propane, 2,2-bis(3,5-dibromo-4-hydroxy-
I phenyl)propane, etc. It is also possible to employ two or more
l,~ different dihydric phenols or a copolymer of a dihydric phenol
11 . I
l~ with a glycol or with hvdroxy or acid terminated polyester, or
30 '~, with a dibasi.c acid in the ev~nt a carbonate copolymer or inter-
polymer rather than a homopolymer is desired Eor use in the pre-
I paration of the aromatic polycarbonates of this invention as -~ell
as ~lends of any of the above materials.
- 4
, ,
... .. ._................... ........ _.. _,_ . .... _ _.. . ...... .... .!
i51 8c~-2g~3 , '
The carbonate precursor can be either a carbonyl halide, a
~carbonate ester or a haloformate. The carbonyl halides which can
be employed are carbonyl bromide, carbonyl chloride and mixtures
thereof. Typical of the carbonate esters that can be employed
are diphenyl carbonate, di-(halophenyl) carbonates such as di-
(chlorophenyl) carbonate, di-(bromophenyl) carbonate, di-
(trichlorophenyl) carb<nate, 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 mix- !
¦~tures thereof. The haloformates suitable for use herein include
!i bishaloformates of dihydric phenols (bischloroformates of hydro-
;lquinone, etc.) or glycols (bishaloformates of ethylene glycol,
,~ineopentyl glycol, polyethylene glycol, etc.~. While other carbon-¦
I ate 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. These are dis-
¦Iclosed in U.S. Patent 3,169,121. ~ ; - '
1'
¦ The aromatic polycarbonates of this invention are prepared
¦Iby employing a molecular weight regulator, an acid acceptor and
a catalyst. The molecular weight regulators which can be employed¦
; include monohydric phenols such as phenol, chroman-I, paratertiary
butylphenol, parabromophenol, primary and secondary amines, etc.
Preferably, phenol is e~ployed as the molecular weight regulator.
A suitable acid acceptor can be either an organic or an
¦ inorganic acid acceptor. ~ suitable organic acid acceptor is a
tertiary amine and lncludes such materials as pyridine, triethyl-
~ amine, dimethylaniline, trlbutylamine, etc. The inorganic acidacceptor can be one which can be either a hydroxide, a carbonate,
~¦ a bicarbonate, or a phosphate of an alkali or alkaline earth
¦~ metal.
1! _ 5 _
~ 3~ ~`5~ 8C~I-296~ ~
~ The catalysts whlch can be employed can be any of the suit- ¦
¦able catalysts that aid the polymerization of bisphenol~A with
phosgene. Suitable catalysts include tertiary amines such as
triethylamine, tripropylamine, N,N-dimethylaniline, quaternary
ammonium compounds such as tetraethylammonium bromide, cetyl
triethylammonium bromide, tetra-n-heptylammonium iodide, tetra-
n-propylammonium bromide, tetramethylammonium chloride, tetra-
methylammonium hydroxide, tetra-n-butylammonium iodide, benzyl-
trimethylammonium chloride and quaternary phosphonium compounds
such as n-butyl-~riphenyl phosphonium bromide and mekhyltriphenyl
phosphonium bromide.
Also included herein are branched polycarbonates wherein a
polyfunctional aromatic compound is reacted with the dihydric
phenol and carbonate precursor to provide a thermoplastic randomly
branched polycarbonate.
These polyfunctional aromatic compounds contain at least
three functional groups which are caxboxyl, carboxylic anhydride,
haloformyl or mixtures thereof. Examples of these polyfunctional
aromatic compounds include trimellitic anhydride, trimellitic
acid, trimellityl trichloride, 4-chloroformyl phthalic anhydride,
pyromellitic acid, pyromellitic dianhydride, mellitic acid, melli-¦
tic anhydride, trimesic acid, benzophenonetetracarboxylic acid,
benzophenonetetracarboxylic anhydride, and ~he li~e. The
preferred polyfunctional aromatic compounds are trimellitic
anhydride or trimellitic acid, or their haloformyl derivatives.
Also included herein are blends of a linear polycarbonate
and a branched polycarbonate.
DESCRIPTION OF T~E PREFERRED EMBODIMENT
The following examples are set forth to more clearly illus-
trate the invention. Unless otherwise specified, parts or per-
~ Icents are y weight. - 6 -
~1 1
6,~31
8CH -2963
EXAMPLE 1
~ethod of Pre arin A New Phos hite- ¦
276 grams (2.94 moles) of phenol and 200 grams (1.47 moles)
of 2,4,6-trlmethylphenolwere heated at 50C under nitrogen until
melted and then 201.9 grams (1.47 moles) of phosphorous trichloride !
were added dropwise. When the phosphoroustrichloride addition was ~
complete, the mixture was heated to 100C and held at this temperaj
ture overnight. Vacuum was applied and unreacted phenol and
trimethylphenol were distilled off. The product, diphenyl-(2,4,6-¦
trimethylphenyl~phosphite, was distilled at 165 to 170C at 0.1
mm.Hg. to afford a clear colorless liquid. The proton nuclear
magnetic resonance (NMR) analysis showed the methyl protons at
2.27 ~ (9.1 H) and the aromatic protons at 6.80 and 7.15 ~ (11.9 H)~
Structure:
~o--P~o~3~ '
EXP~lPLE 2
Method of Preparing_ A New Phosphite
Bis(2,4,6-trimethylphenYl)PhenY1 PhosPhite
103.6 grams (1.1 moles) of phenol and 300 grams (2.2 moles)
of 2,4,6-trimethylphenol were heated at 50C under nitrogen until ¦
melted and then 151.1 grams (1.1 moles) of phosphoroustrichloride ¦
were added dropwise. When the phosphoroustrichloride addition was ¦
complete, the mixture was heated at 100C and held at this tem?eral
ture overnight. Vacuum was applied and unreacted phenol and tri- ¦
methylphenol distilled off. The product, bis(2,4,6-trimethyl-
¦phenyl)phenyl phosphite, was distilled at 187 -o 190C at 0.35
mm.Hg. to afford a clear colorless liquid. The proton NMX showed ¦
the methyl protons at 2.27 ~ (17.2 H) and the aromatic protons at ¦
6.80 and 7.15 ~ (9.8 H). 5
i Structure: ~CH-2963
(~~~
EXAMPLE 3
Method of Preparing A New Phosphite:
Tris(2,4~6-trimeth~lphenyl)~hosphite
300 grams (2.2 moles) of 2,4,6-trimethylphenol were heated
under nitrogen until melted and then 89.9 grams (0.65 mole) of
phosphorous trichloride were added dropwise. When the addition
10 was complete, the mixture was heated to 100C and held at this
temperature overnight. Vacuum was applied and unreacted trimethyl~
phenol distilled off. The product, tris(2,4,6-trimethylphenyl)
phosphite, was distilled at 1~2-174C at 0.3 mm.Hg. to afford a
clear colorless liquid which solidified on standing, mp 92-95~C.
15 The proton NMR showed the methyl protons at 2.23 ~ (27 H) and the
aromatic protons at 6.77 ~(6 H).
Structure:
. . , (~ p
EXAMPLE 4
Method of Pre~arinq A New Phos~hite: -
: ~T~
564.7 grams (6 moles) of phenol and 619 grams ~3 moles) of
2,4-di-t-butylphenol were heated at 50C under nitrogen until
melted and then 412.1 grams (3 moles) of phosphorous trichloride
were added dropwise. When the addition was complete, the mi~ture
was heated to 100C and held at this temperature overnight.
Vacuum was applied and unreacted phenol and di-t-butylphenol
distilled off. The product, diphenyl-(2,4-di-t-butylphenyl)
phosphite,-was distilled at 175 to 180C at 0.15 mm.Hg. to afford !
a pale yellow liquid. The proton NMR showed the t-butyl protons
~t 1. ~19.8 H~ and the aromatic protons at 7.1 ~ (10.2 H).
- 8 -
,. ,.._.. ._.,..
3~6~
~ H-2963
Structure:
`~--P~)2
EX~MPLE 5
Method of Prepar.ing A New Phosphite-
Bis(2,4-di-t-butylphen~l)pheriyl phosphite
70.5 grams (0.75 mole) of phenol and 309.5 grams (1.5 moles)
of ~,4-di~t-butylphenol were heated at 50C under nitrogen until
melted and then 96.2 grams (0.7 mole) of phosphorous trichloride
were added dropwise. When the addition was complete, the mixture
was heated to 100C and held at this temperature overnight.
Vacuum was applied and unreacted phenol and di-t-butylphenol
distilled off. The product, bis(2,4-di-t-butylphenyl)phenyl
phosphite, was distilled at 180C at 0.2 mm.Hg. to afford a pale
yellow liquid. The proton NMR showed the t-butyl protons at
1.3 ~(33.4 H) and the aromatic protons at 7.2 &r (13.6 H).
Structure:
~ ~ p______
EXAMPLE 6
Method of Preparing A New Phosphite:
Diphenyl~(2,6-dimethylphenyl) phosphite
769.8 grams (8.18 moles) of phenol and 500 grams (4.09 moles)
of 2,6-dimethylphenol were heated at 50C under nitrogen until
melted and then 561.7 grams (4.09 moles) of phosphorous trichlorid~
were added dropwise. When the addition was complete, the mixture
was heated to 100C and heid at this temperature overnight.
Vacuum was applied and unreacted phenol and dimethylphenol dis-
tilled off. The product, diphenyl-(2,6-dimethylphenyl) phosphite,
was distilled at 155C at 0.2 mm.Hg. to afford a clear colorless
liquid. The proton NMR showed the methyl protons at 2.33 ~(5.6
and the aromatic protons at 7.00 and 7.17 ~ (13.4 H).
8CH-2963
Structure: i
~ ~ P~
S EXAMPLE 7
Method of Preparing A New Phosphite:
Bis~2!6-dimethylphenyl)phenyl phosphite
280 grams (2.04 moles) of phenol and 500 grams (4.09 moles)
¦of 2,6-dimethylphenol were heated at 50C under nitrogen until
melted and then 192 grams (2.04 moles) of phosphorous trichloride ¦
were added dropwise. When the addition was complete, the mixture
was heated to 100C and held at this temperature overnight.
Vacuurn was applied and unreacted phenol and dimethylphenol dis-
tilled off. The product, bis(2,6-dimethylphenyl)phenyl phosphite,
was distilled at 155 to 165 C at 0.2 mm.Hg. to afford a clear
colorless liquid. The proton NMR showed the methyl protons at
2.33 ~ (11.4 H) and the aromatic protons at 7.00 and 7.17
(11.6 H).
¦ Structure:
20 ~P-----O
EXAMPLE 8
Method of Pre~aring A New Phosphite: ¦
Di-n-octyl-(2,4,5-trimethyl~henyl) phosphite
50 grams (0.14 mole) of diphenyl-(2,4,6-trimethylphenyl)
25phosphite, 40 grams (0.31 mole) of l-octanol, and 0.25 grarns of
¦sodium methoxide were heated under a vacuum of 30 mm.Hg. Phenol
jwas removed from the reaction mixture through a Vigreaux coiumn at
a pot temperature of 130C and a head temperature of 93C at 30
mrn.Hg. The pot ternperature was increased to 160C and-the pres-
sure reduced to 0.2 mm.Hg. to insure complete removal of phenoland excess octanol. The product, di-n-octyl-(2,4,6-trimethyl-
phenyl) phosphite, was distilled at 138 to 139C at 0.2 mrn.Hy.
I ' - 10 - I
1131~$~ 8CH-2963
to afford a clear colorless liquid. The proton NMR showed li
aliphatic protons centered at 0.85 and 1.3 &~ the methyl groups
of the trimethylphenyl moiety at 2.3 &~ the methylene groups
adjacent to the oxygen at 3.35 ~, and the aromatic protons at 7.0
Structure:
_____~ ~ ----C8~17)~
EXAMPLE 9 1 ,
Method of Preparing A New Phosphite:
Di(2-eth 1-1-hexyl)-(2,4,6-trimethylPhenyl) phosPhite
Y , _ _ -
S0 grams (0.14 mole) of diphenyl-(2,4,~-trimethylphenyl)
phosphite, 40 grams (0.31 mole) of 2-ethyl-l-hexanol, and 0.25
grams of sodium methoxide were heated under a vacuum of 30 mm.Hg.
Phenol was removed from the reaction mixture through a Vigreaux-
col~mn at a head temperature of 94C at 30 mm.Hg. The pot tempera-
ture was increased to 160C and the pressure reduced to 0.2 mm.Hg.¦
to insure complete removal of phenol and excess hexanol. The
product, di(2-ethyl-l-hexyl~-)2,4,6-trimethylphenyl) phosphite,
was distilled at 150 to 155C at 0.2 mm.Hg. to afford a clear
colorless liquid. The proton NMR showed aliphatic protons centered
at 0.9 and 1.3 ~, the methyl groups of the trimethylphenyl moiety ~
at 2.25 &, the methylene group adjacent to the oxygen at 3-95 &~ !
and the aromatic protons at 7.0 ~.
Structure:
~ p ~ o CH21CHC4H9)2
CH2CH3
- t
EXAMPLE 1O
Method of PreParing A New Phosphite:
Di-2-octvl (2 4,6-trimethYlPhenYl) phosphite
-50 grams (0.14 mole) of diphenyl-(2,4,6-trimethylphenyl)
phosphite, 40 grams (0.31 mole) of 2-octanol, and 0.25 grams of
sodium methoxide were heated under a vacuum of 30 mm.Hg. at loOQC.
, - 11.-
8CH-2963
Phenol was removed from thé reaction mixture through a Vigreaux
column at a head temperature of 94C at 30 mm. Hg. The pot
temperature was increased to 160C and the pressure reduced to
l 0.2 mm. Hg. to insure complete removal of phenol and excess
51 octanol. The product, di-2-octyl-(2,4,6-trimethylphenyl) phosphit~
was distilled at 168C at 0.2 mm. Hg. to afford a clear colorless
liquid. The proton NMR showed aliphatic protons centered at
0.85 and 1.3 ~, the methyl groups of the trimethylphenyl moiety
at 2.25 ~, the methine groups adjacent to the oxygen at 4.4 ~, ¦
L0 and the aromatic protons at 6.8 ~.
Structure:
~ ~OfHC6Pl~)
EX~MPLE 11
Method of Preparing a New Phosphite:
2,4,6-Trimethylphenyl neopentyl phosphite.
144.8 grams (0.41 mole) of diphenyl-(2,4,6-trimethylphenyl)
, phosphite, 42.7 grams (0.41 mole) of dimethyl propanediol and 0.5 ¦
201¦grams of sodium methoxide were heated under a vacuum of 30 mm. Hg.
~¦Phenol was removed from the reaction mixture through a Vigreaux
¦~column at a head temperature of 94C at 30 mm. Hg. The pot tem-
perature was increased to 160C ror 3 hours to insure complete
removal of phenol. The product, 2,4,6-trimethylphenyl neopentyl
25 ¦ phosphite was distilled at 127 to 130C at 0.35 mm. Hg. to afford ¦
¦¦a clear colorless liquid. The proton NMR showed aliphatic protons ¦
¦~at 0.6 and 1.2~-, the methyl groups of the trimethylphenyl moiety
I at 2.2,~, the methylene groups adjacent to the oxygen at 3.4 and
j 4.3 &7 and the aromatic protons at 6.8 ~.
30 1 Structure:
--P~X
.
1 _ 12 -
,.; , .,_,_ ,. ~ _ . ~ . . , . __ _,.. _, _._ _ , . . . ,, . _ _ . _ . .. _ ___
~13~6S~
8CH-2963
EXAMPLE 12
7 Method of Preparing a New Phosphite:
2,4-Di-t-butyle~enyl neopent~l phosphite
150 grams (0.36 mole) of diphen~l-(2,4,-di-t-butylphenyl)
phosphite, 37 grams (0.36 mole) of dimethyl propanediol, and 0.5
grams of sodium methoxide were heated under a vacuum of 30 mm. Hg.-
Phenol was removed from the reaction mixture through a Vigreaux-
column at a head temperature of 94C at 30 mm. Hg. The pot tem-
perature was incerased to 160 C for 3 hours to insure complete
removal of phenol. The product, 2,4-di-t-butylphenyl neopentyl
phosphite was distilled at 110C at 0.1 mm. Hg. to afford a clear
colorless liquid which solidified to a white solid upon standing
(m.p. 68-73C). The proton NMR showed aliphatic protons from
0.6 to 1.5/5-, the methylene groups adjacent the oxygen at 3.5 and
4.3 ~, and the aromatic protons centered at 7.2 ~_
Structure:
~ \0~
EXAMPLE 13
Method_of Preparing a New Phosphite:
2,6-Dimethvlphenvl neo~entvl ~hosnhite
.. ... .. .. f .~ ~ , ,, ,~
270 grams (0.8 mole) of diphenyl-(2,6-dimethylphenyl)
phosphite, 104.2 grams (1.0 mole) of dimethyl propanediol, and
25 -0.5 grams of sodium methoxide were heated under a vacuum of 30 mm..
Hg. Phenol was removed from the reaction mixture through a
Vigreaux column at a head temperature of 94C at 30 mm. ~g. The
pot temperature was increased to 160C for 3 hours to insure
complete removal of~phenol. The product, 2,6-dimethylphenyl
. .
~3~ C~1-2~63
neopentyl phosphite, was distilled at 95C to 115C a-t 0.4 ~m, Hg.
to afford a clear colorless liquid. The proton ~MR showed ali-
phatic pro-tons from 0.8 to 1.4 ~J, the methyl groups of the di-
methylpheny]. moiety at 2.3 ~, the methylene groups adjacent the
oxygen at 3.4 and 4.3 ~, and the aromatic protons at 7.2 ~.
Structure:
' ~\0~
EXAMPLE 14
A polycarbonate composition of a homopolymer of 2,2-bis(4-
hydroxyphenyl)propane tbisphenol-A) was prepared by reacting
essentially equimolar amounts of bisphenol-A and phosgene in an
organic medium with triethylamine, sodium hydroxide and phenol
under standard conditions and was mixed with the stabilizers
shown in Table I plus a trace amount of a commercially obtained
blue pigment by tumbling the ingredients in a laboratory tumbler.
This mixture was then fed to an extruder, which extruder was
operated at about 500F, and the extruded strands chopped into
pellets. The pellets were then injected molded at 600F and 680F
into test samples of about 3 inches by 2 inches by 1/8 inch thick.
Thermal stability to discoloration of the tes~ samples was
measured in accordance with ASTM Yellowness Index tYI) Test D1925
on samples molded at 600F and 680F. The results obtained are
set forth in TABLE I below.
- 14 -
.. .. . ... .. . . . . . . .. . . . . . ... ..
~3~;S~
8CH-2963
TAELE I
Thermal Stability
Amount YI of_Tçst Samples Molded At:
Stabilizer(wt%) 600 F 680 F
*A 0.1 3.1 10.1
Example 1 0.04 2.6 5.5
Example 1 0.08 2.6 5.7
Example 2 0.04 2.8 6.1
Example 2 0.08 2.4 5.9
Example 3 0.05 2.9 - 5.7
Example 3 0.10 2.8 6.0
* As disclosed in Ger. Pat. 1,694,285 and referred to in U.S.
Pat. 3,794,629: 1 part octyldiphenyl phosphite
2 parts 3,4-epoxy-cyclohexylmethyl-3,4
~; epoxycyclohexane carboxylate
The test samples molded at 680F were subjected to accelerated
heat aging by placing them in an oven at 140C for a period of
1 week and 2 weeks. The results obtained are shown in TABLE II
below.
TABLE II
YI of Heat Aged 680 F
Amount Molded Test SamPles After
20 Stabilizer ~wt%) Initial 1 week 2 weeks
A 0.110.1 20.7 28.2
Example 1 0.045.5 14.3 22.3
Example 1 0.085.7 14.0 23.8
Example 2 0.046.1 15.6 23.2
Example 2 0.085.9 14.6 23.6
Example 3 0.055.7 15.8 23.9
Example 3 0.1 6.0 1407 24.4
The results in TABLES I and II above reveal that all of the
Example 1, 2 and 3 stabilizers of the invention imparted signifi-
cantly better thermal stability than did prior art stabilizer A,
even when employed at noticeably lower concentrations.
- 15 -
. , . . ...................... . .... . _, . .. .
~.
~3
8CH-2963
EXAMPLE 15
A polycarbonate composition was prepared as described in
Example 14 and admixed with stabilizers, extruded, and molded into
test samples and the YI o the test samples was determined as
5 described in Example 14. The results are shown in Table III below.
TABLE III
THERMAL STABILITY
YI of Test Samples
Amount Molded at
Stabilizer (Wt. &~ 600F 680F
A 0.1 2.0 6.4
Example 4 0.04 2.1 3.7
Example 4 0.08 1.6 4.7
From the results shown in Table III above, it can be seen-
that the Example 4 stabilizer of the invention, even when employed
at lower concentrations, imparted comparable or improved thermal
stability over prior art stabilizex A, particularly at the higher
680F molding temperature.
EXAMPLE 16
A polycarbonate composition was prepared as described in
Example 14 and admixed with stabilizers, extruded, and molded into
test samples. The YI of the test samples was determined as
described in Example 14 and are shown in Table IV below wherein
"Control" identifies a polycarbonate composition without stabilize
TABLE IV
THERMAL STABILITY
YI of Test Samples
Amount Molded at
Stabilizer (Wt. %) 600F 680F
Control - 3.3 8.1
A - 0.1 2.0 5.7
~3~6S~ ~C~-2g~ ,
TABLE IV (CONT'D.)
YI of Test Samples
Amount Molded At
Stabilizer (Wt. %) 600F 680F
Example 8 0.04 2.0 4.9
" " 0.08 1.8 4.4
Example 9 0.04 1.9 4.7
l " " 0.08 1.8 4.8
! Example 10 0.04 2.3 4.4
I0 " " 0.08 2.0 4.1
From the results shown in Table IV above, it can be seen that
the stabilizers of Examples 8, 9 and 10, although used at lower
concentrations, imparted thermal s~ability comparable to ~hat of
prior art stabilizer A at the 600F moldiny temperature. However,
thermal stability of the invention stabilizers show a marked
improvement over stabilizer ~ at the elevated molding temperature !
~ of 680F.
; EXAMPLE 17
A polycarhonate composition was prepared as described in
20 ¦ Example 14 and admixed with stabilizers, extruded and molded into
test samples. The YI of the test samples was determined as des-
cribed in Example 14 and the results obtained are shown in Table
V below wherein "Control" identifies the polycarbonate composition
without stabilizer.
25 1 TABLE V
Thermal Stab_lity
YI of Test Samples
Amount Molded At
Stabilizer (Wt. ~) 6Q0F 680F
, I
Control - 3.5 6.3
A 0.1 2.1 6.9
*B 0.025 2.2 4.0
*B 0.05 1.8 4.1
~ 31~S1 8CH-29~3
TABLE V (CONT'D.)
YI of Test Samples
AmountMolded At
Stabilizer (Wt. ~) 600F 680F
_ _
Example 11 0.03 1.9 3.7
¦¦ Example 11 0.06 1.7 2.9
Example 12 0.035 1.7 3.4
~ Example 12 0.07 1.6 3.5
I * As disclosed in U.S. Patent 3,509,091: phenyl neopentyl
101 phosphite.
As can be seen from the results in Table V, the stabilizers
f Examplesll and 12 exhibit significantly better thermal stability
~than prior art stabilizers A or B at about comparable concentra-
tions, particulary at the higher molding temperature of 680F.
EXAMPLE 18
The molded test samples of Example 17 were also subjected to ,
ASTM D-1003 to measure their light transmission before and after
they were steam autoclaved at 250F to de~ermine their hydrolytic
1 stability. The results obtained are shown in TABL~ VI below:
TABLE VI
Hydrolytic Stability
.% Light Transmission
Stabilizer (Wt. %)
Example 11 Example 12¦
25 ITime (hrs.) B (0.025) (0.03) (0.035)
:, I _
0 87.6 87.7 87.6
24 47.7 80.8 87.1 1-
48 3.2 15.3 84.1
72 - - 63.2
30 1 The results in Table VI above reveal that the hydrolytic
¦ stability of polycarbonate compositions containing the stabilizers ¦
~.,' I . I
- 18
, ~3~S3l J
8CH-2963
l . ',
of E~amples 11 and 12 are significantly superior to prior art
stabilizer B which failed before the end of 24 hours, the failure
¦¦level being generally acknowledged when the light transmission
l level falls below about 75%.
51 EXAMPLE 19
Following the procedure of Example 14, a polycarbonate
composition was prepared, admixed with stabilizers, extruded and
then molded into test samples. The YI of the test samples was
l determined as described in Example 14 and the results obtained
10¦ are set forth in TABLE VII below:
TABLE VII
Thermal Stab ~
YI of Test Samples
Amount Molded At
Stabilizer (Wt. ~) 600F 680F
__ I
A 0.1 2.2 7.3
Example 13 0.03 1.8 3.8
Example 13 0.06 1.5 3.2
l From the results in TabLe VII above, it can be seen that the
20 1I stabilizer o~ the invention imparts significantly superior thermal
¦ stability to polycarbonate compositions than prior art stabilizer
¦ A, even at much less concentration levels.
Although the stabilizers of the invention have been parti-
l cularly shown employed with high molecular weight aromatic poly-
25 ¦carbonates, it should be understood that this has been by way ofillustrating the general efficacy of these stabilizers with thermo-
! plastic resins. As will be apparent to the skilled artisan, thestabilizers of the invention can also be employed with other
~thermoplastics such as polyolefins, polyvinyl chloride, polyesters
30 ¦and the like, with substan~ially similar facility and efficacy.
I
l I
:~ - 19 -
~ ... ___.... ..... _ ._ . i
