Note: Descriptions are shown in the official language in which they were submitted.
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FLAME-PROOF IMPACT RESISTANT-MODIFIED POLYCARBONATE COMPOSITIONS
The present invention relates to impact-modified polycarbonate compositions
which
comprise a graft polymer prepared in the emulsion polymerization process and a
salt of a
phosphinic acid, the use of the polycarbonate compositions for the production
of shaped
articles and the shaped articles themselves.
WO-A 2005/044906 discloses thermoplastic moulding compositions comprising at
least
one metal salt of hypophosphoric acid and at least one aromatic polycarbonate
resin and a
mixture thereof with a styrene-containing graft copolymer resin having a
rubber content of
5-15 %. The contents of the styrene-containing graft copolymer are 10-40 wt.%.
The
moulding compositions obtained are distinguished by good flame resistance,
high heat
stability under processing conditions and good weather resistance. Because of
the low
rubber content, other properties, in particular mechanical properties, are at
a low level.
WO-A 1999/57192 describes thermoplastic moulding compositions comprising 5-96
wt.%
of a polyester or polycarbonate, 1-30 wt.% of a phosphinic acid salt and/or of
a
diphosphinic acid salt and/or polymers thereof, 1-30 wt.% of at least one
organic
phosphorus-containing flameproofing agent, and possible further additives.
DE-A 102004049342 discloses thermoplastic moulding compositions comprising 10-
98
wt.% of thermoplastic polymer, 0.01-50 wt.% of highly branched polycarbonate
or highly
branched polyester or mixtures thereof, 1-40 wt.% of halogen-free
flameproofing agent
chosen from the group of P-containing or N-containing compounds or of P-N
condensates
or mixtures thereof, and possible further additives.
JP-A 2001-335699 describes flameproofed resin compositions comprising two or
more
thermoplastic resins chosen from styrene resin, aromatic polyester resin,
polyamide resin,
polycarbonate resin and polyphenylene ether resin and one or more (in)organic
phosphinic
acid salts, and possible further additives.
JP-A 2001-261973 (Daicel Chemical Industries Ltd.) describes compositions of
thermoplastic resins and (in)organic phosphinic acid salts. A combination of
PBT, calcium
phosphinate and PTFE is given as an example.
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JP-A 2002-161211 discloses compositions of thermoplastic resins and
flameproofing
agents, such as salts of phosphinic and phosphoric acid and derivatives
thereof. A
combination of PBT, ABS, polyoxyphenylene, calcium phosphinate, an
organophosphate
and glass fibres is given as an example.
Flameproofing agents which are conventional according to the prior art for
polycarbonate/ABS blends are organic aromatic phosphates. These compounds can
be in a
low molecular weight form, in the form of a mixture of various oligomers or in
the form of
a mixture of oligomers with low molecular weight compounds (e.g. WO-A 99/16828
and
WO-A 00/31173). The good activity as flameproofing agents is counteracted
adversely by
the highly plasticizing action of these compounds on the polymeric
constituents, so that the
heat distortion point of these moulding compositions is not satisfactory for
many uses.
The object of the present invention is to provide impact-modified
polycarbonate moulding
compositions having an optimum combination of high heat distortion point, good
resistance to chemicals and good flameproofing, in particular in the glow wire
test
according to IEC 60695-2-12.
It has now been found, surprisingly, that moulding compositions or
compositions
comprising A) polycarbonate, B) rubber-modified graft polymer prepared in the
emulsion
polymerization process and C) a salt of a phosphinic acid have the desired
profile of
properties.
It has thus been found, surprisingly, that compositions comprising
A) 50 to 99.4 parts by wt., preferably 73 to 98 parts by wt., particularly
preferably 82
to 91 parts by wt. (in each case based on the sum of the parts by weight of
components A+B+C) of aromatic polycarbonate and/or aromatic polyester
carbonate,
B) 0.5 to 20 parts by wt., preferably 1 to 12 parts by wt., particularly
preferably 2 to 6
parts by wt. (in each case based on the sum of the parts by weight of
components
A+B+C) of rubber-modified graft polymer prepared in the emulsion
polymerization
process,
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C) 0.1 to 30 parts by wt., preferably 1 to 15 parts by wt., particularly
preferably 7 to 12
parts by wt. (in each case based on the sum of the parts by weight of
components
A+B+C) of a salt of a phosphinic acid,
D) 0 to 20 parts by wt. (based on the sum of the parts by weight of components
A+B+C = 100) of rubber-free vinyl (co)polymer and/or polyalkylene
terephthalate,
preferably the composition is free from rubber-free vinyl (co)polymer and/or
polyalkylene terephthalate,
E) 0 to 50 parts by wt., preferably 0.5 to 25 parts by wt. (in each case based
on the
sum of the parts by weight of components A+B+C= 100) of additives,
wherein all the parts by weight stated in the present application are
standardized such that
the sum of the parts by weight of components A+B+C in the composition is 100,
achieve the abovementioned technical object.
Component A
Aromatic polycarbonates and/or aromatic polyester carbonates according to
component A
which are suitable according to the invention are known from the literature or
can be
prepared by processes known from the literature (for the preparation of
aromatic
polycarbonates see, for example, Schnell, "Chemistry and Physics of
Polycarbonates", In-
terscience Publishers, 1964 and DE-AS 1 495 626, DE-A 2 232 877, DE-A 2 703
376,
DE-A 2 714 544, DE-A 3 000 610 and DE-A 3 832 396; for the preparation of
aromatic
polyester carbonates e.g. DE-A 3 077 934).
Aromatic polycarbonates are prepared e.g. by reaction of diphenols with
carbonic acid
halides, preferably phosgene, and/or with aromatic dicarboxylic acid
dihalides, preferably
benzenedicarboxylic acid dihalides, by the interfacial process, optionally
using chain
terminators, for example monophenols, and optionally using branching agents
which are
trifunctional or more than trifunctional, for example triphenols or
tetraphenols. A
preparation via a melt polymerization process by reaction of diphenols with,
for example,
diphenyl carbonate is likewise possible.
Diphenols for the preparation of the aromatic polycarbonates and/or aromatic
polyester
carbonates are preferably those of the formula (I)
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(B)X (B)X OH
HO
p
(I)
wherein
A is a single bond, C1 to C5-alkylene, C2 to C5-alkylidene, C5 to C6-
cycloalkylidene, -
0-, -SO-, -CO-, -5-, -SO2-, C6 to C12-arylene, on to which further aromatic
rings
optionally containing hetero atoms can be fused,
or a radical of the formula (II) or (III)
-Cl
-
X
\ 6
R R (II)
CH
CH
3
CH3
CH3 (III)
B is in each case C1 to C12-alkyl, preferably methyl, or halogen, preferably
chlorine
and/or bromine,
x is in each case independently of one another 0, 1 or 2,
p is 1 or 0, and
R5 and R6 can be chosen individually for each X1 and independently of one
another denote
hydrogen or C1 to C6-alkyl, preferably hydrogen, methyl or ethyl,
X1 denotes carbon and
in denotes an integer from 4 to 7, preferably 4 or 5, with the proviso that on
at least
one atom X1 R5 and R6 are simultaneously alkyl.
Preferred diphenols are hydroquinone, resorcinol, dihydroxydiphenols, bis-
(hydroxyphenyl)-C1-C5-alkanes, bis-(hydroxyphenyl)-C5-C6-cycloalkanes, bis-
(hydroxy-
phenyl) ethers, bis-(hydroxyphenyl) sulfoxides, bis-(hydroxyphenyl) ketones,
bis-
(hydroxyphenyl) sulfones and a,a-bis-(hydroxyphenyl)-diisopropyl-benzenes and
derivatives thereof brominated on the nucleus and/or chlorinated on the
nucleus.
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Particularly preferred diphenols are 4,4'-dihydroxydiphenyl, bisphenol A, 2,4-
bis(4-
hydroxyphenyl)-2-methylbutane, 1, 1 -bis-(4-hydroxyphenyl)-cyclohexane, 1,1-
bis-(4-
hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-dihydroxydiphenyl sulfide,
4,4'-
dihydroxydiphenyl sulfone and di- and tetrabrominated or chlorinated
derivatives thereof,
such as, for example, 2,2-bis(3-chloro-4-hydroxyphenyl)-propane, 2,2-bis-(3,5-
dichloro-4-
hydroxyphenyl)-propane or 2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane. 2,2-
Bis-(4-
hydroxyphenyl)-propane (bisphenol A) is particularly preferred.
The diphenols can be employed individually or as any desired mixtures. The
diphenols are
known from the literature or obtainable by processes known from the
literature.
Chain terminators which are suitable for the preparation of the thermoplastic
aromatic
polycarbonates are, for example, phenol, p-chlorophenol, p-tert-butylphenol or
2,4,6-
tribromophenol, but also long-chain alkylphenols, such as 4-[2-(2,4,4-
trimethylpentyl)]-
phenol, 4-(1,3-tetramethylbutyl)-phenol according to DE-A 2 842 005 or
monoalkylphenols or dialkylphenols having a total of 8 to 20 carbon atoms in
the alkyl
substituents, such as 3,5-di-tert-butylphenol, p-iso-octylphenol, p-tert-
octylphenol, p-
dodecylphenol and 2-(3,5-dimethylheptyl)-phenol and 4-(3,5-dimethylheptyl)-
phenol. The
amount of chain terminators to be employed is in general between 0.5 mol% and
10 mol%,
based on the sum of the moles of the particular diphenols employed.
The thermoplastic aromatic polycarbonates have average weight-average
molecular
weights (Mw, measured e.g. by GPC, ultracentrifuge or scattered light
measurement) of
from 10,000 to 200,000 g/mol, preferably 15,000 to 80,000 g/mol, particularly
preferably
24,000 to 32,000 g/mol.
The thermoplastic aromatic polycarbonates can be branched in a known manner,
and in
particular preferably by incorporation of from 0.05 to 2.0 mol%, based on the
sum of the
diphenols employed, of compounds which are trifunctional or more than
trifunctional, for
example those having three and more phenolic groups.
Both homopolycarbonates and copolycarbonates are suitable. 1 to 25 wt.%,
preferably 2.5
to 25 wt.%, based on the total amount of diphenols to be employed, of
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polydiorganosiloxanes having hydroxyaryloxy end groups can also be employed
for the
preparation of the copolycarbonates according to the invention according to
component A.
These are known (US 3 419 634) and can be prepared by processes known from the
literature. The preparation of copolycarbonates containing
polydiorganosiloxane is
described in DE-A 3 334 782.
Preferred polycarbonates are, in addition to bisphenol A homopolycarbonates,
copolycarbonates of bisphenol A with up to 15 mol%, based on the sum of the
moles of
diphenols, of other diphenols mentioned as preferred or particularly
preferred, in particular
2,2-bis(3,5-dibromo-4-hydroxyphenyl)-propane.
Aromatic dicarboxylic acid dihalides for the preparation of aromatic polyester
carbonates
are preferably the diacid dichlorides of isophthalic acid, terephthalic acid,
diphenyl ether
4,4'-dicarboxylic acid and of naphthalene-2,6-dicarboxylic acid.
Mixtures of the diacid dichlorides of isophthalic acid and of terephthalic
acid in a ratio of
between 1:20 and 20:1 are particularly preferred.
A carbonic acid halide, preferably phosgene, is additionally co-used as a
bifunctional acid
derivative in the preparation of polyester carbonates.
Possible chain terminators for the preparation of the aromatic polyester
carbonates are, in
addition to the monophenols already mentioned, also chlorocarbonic acid esters
thereof
and the acid chlorides of aromatic monocarboxylic acids, which can optionally
be
substituted by C 1 to C22-alkyl groups or by halogen atoms, and aliphatic C2
to C22-
monocarboxylic acid chlorides.
The amount of chain terminators is in each case 0.1 to 10 mol%, based on the
moles of
diphenol in the case of the phenolic chain terminators and on the moles of
dicarboxylic
acid dichloride in the case of monocarboxylic acid chloride chain terminators.
The aromatic polyesters carbonates can also contain incorporated aromatic
hydroxycarboxylic acids.
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The aromatic polyester carbonates can be either linear or branched in a known
manner (in
this context see DE-A 2 940 024 and DE-A 3 007 934).
Branching agents which can be used are, for example, carboxylic acid chlorides
which are
trifunctional or more than trifunctional, such as trimesic acid trichloride,
cyanuric acid
trichloride, 3,3',4,4'-benzophenone-tetracarboxylic acid tetrachloride,
1,4,5,8-
naphthalenetetracarboxylic acid tetrachloride or pyromellitic acid
tetrachloride, in amounts
of from 0.01 to 1.0 mol-% (based on the dicarboxylic acid dichlorides
employed), or
phenols which are trifunctional or more than trifunctional, such as
phloroglucinol, 4,6-
dimethyl-2,4,6-tri-(4-hydroxyphenyl)-hept-2-ene, 4,6-dimethyl-2,4-6-tri-(4-
hydroxyphenyl)-heptane, 1,3,5-tri-(4-hydroxyphenyl)-benzene, 1, 1, 1 -tri-(4-
hydroxy-
phenyl)-ethane, tri-(4-hydroxyphenyl)-phenylmethane, 2,2-bis[4,4-bis(4-hydroxy-
phenyl)-
cyclohexyl] -propane, 2,4-bis(4-hydroxyphenyl-isopropyl)-phenol, tetra-(4-
hydroxyphenyl)-methane, 2,6-bis(2-hydroxy-5-methyl-benzyl)-4-methyl-phenol, 2-
(4-
hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propane, tetra-(4-[4-hydroxyphenyl-
isopropyl]-
phenoxy)-methane or 1,4-bis [4,4'-dihydroxytriphenyl)-methyl] -benzene, in
amounts of
from 0.01 to 1.0 mol%, based on the diphenols employed. Phenolic branching
agents can
be initially introduced with the diphenols, and acid chloride branching agents
can be
introduced together with the acid dichlorides.
The content of carbonate structural units in the thermoplastic aromatic
polyester carbonates
can vary as desired. The content of carbonate groups is preferably up to 100
mol%, in
particular up to 80 mol%, particularly preferably up to 50 mol%, based on the
sum of ester
groups and carbonate groups. Both the ester and the carbonate content of the
aromatic
polyester carbonates can be present in the polycondensate in the form of
blocks or
randomly distributed.
The relative solution viscosity (rlrel) of the aromatic polycarbonates and
polyester
carbonates is in the range of 1.18 to 1.4, preferably 1.20 to 1.32 (measured
on solutions of
0.5 g of polycarbonate or polyester carbonate in 100 ml of methylene chloride
solution at
25 C).
The thermoplastic aromatic polycarbonates and polyester carbonates can be
employed by
themselves or in any desired mixture.
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Component B
Component B includes one or more graft polymers of
B.1 5 to 95 wt.%, preferably 30 to 90 wt.% of at least one vinyl monomer on
B.2 95 to 5 wt.%, preferably 70 to 10 wt.% of at least one graft base chosen
from the
group consisting of diene rubbers, EP(D)M rubbers (i.e. those based on
ethylene/propylene and optionally diene) and acrylate, polyurethane, silicone,
silicone/acrylate, chloroprene and ethylene/vinyl acetate rubbers.
The graft base B.2 in general has an average particle size (d50 value) of from
0.05 to 5 m,
preferably 0.1 to 0.8 m, particularly preferably 0.2 to 0.4 m.
Monomers B.1 are preferably mixtures of
B. 1.1 50 to 99 parts by wt. of vinylaromatics and/or vinylaromatics
substituted on the
nucleus (such as styrene, a-methylstyrene, p-methylstyrene and p-
chlorostyrene)
and/or (meth)acrylic acid (C1-C8)-alkyl esters (such as methyl methacrylate
and
ethyl methacrylate) and
B. 1.2 1 to 50 parts by wt. of vinyl cyanides (unsaturated nitriles, such as
acrylonitrile
and methacrylonitrile) and/or (meth)acrylic acid C,-C8-alkyl esters, such as
methyl methacrylate, n-butyl acrylate and t-butyl acrylate, and/or derivatives
(such as anhydrides and imides) of unsaturated carboxylic acids, for example
maleic anhydride and N-phenyl-maleimide.
Preferred monomers B. 1.1 are chosen from at least one of the monomers
styrene, a-
methylstyrene and methyl methacrylate, and preferred monomers B.1.2 are chosen
from at
least one of the monomers acrylonitrile, maleic anhydride and methyl
methacrylate.
Particularly preferred monomers are B. 1.1 styrene and B. 1.2 acrylonitrile.
Preferred graft bases B.2 are diene rubbers (for example based on butadiene
and isoprene)
or mixtures of diene rubbers. Diene rubbers in the context according to the
invention are
also to be understood as meaning copolymers of diene rubbers or mixtures
thereof with
further copolymerizable monomers (e.g. according to B.1.1 and B.l .2). The
graft bases B.2
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in general have a glass transition temperature of < 10 C, preferably < 0 C,
particularly
preferably < -10 C.
Preferably, the graft polymer of components B.1 and B.2 has a core-shell
structure,
wherein component B.1 forms the shell (also called casing) and component B.2
forms the
core (see e.g. Ullmann's Encyclopedia of Industrial Chemistry, VCH-Verlag,
vol. A21,
1992, page 635 and page 656).
The graft copolymers B are prepared by free-radical polymerization by emulsion
polymerization. The emulsion polymerization process is preferably carried out
by redox
initiation with an initiator system of organic hydroperoxide and ascorbic
acid, as is
described, for example, in US 4 937 285.
The gel content of the graft base B.2 is at least 40 wt.%, preferably at least
70 wt.%
(measured in toluene).
Particularly preferred graft polymers B are ABS polymers (emulsion ABS), which
preferably have a core-shell structure, the shell being built up from the
components styrene
(B.1.1) and acrylonitrile (B.2.1), with a core of polybutadiene. Such ABS
polymers are
known to the person skilled in the art and are described e.g. in Ullmanns
Enzyklopadie der
Technischen Chemie, vol. 19 (1980), p. 280 et seq.
Since as is known the grafting monomers are not necessarily grafted completely
on to the
graft base during the grafting reaction, according to the invention graft
polymers B are also
understood as meaning those products which are produced by (co)polymerization
of the
grafting monomers in the presence of the graft base and are also obtained
during the
working up.
Suitable acrylate rubbers according to B.2 of the polymers B are preferably
polymers of
acrylic acid alkyl esters, optionally with up to 40 wt.%, based on B.2, of
other
polymerizable ethylenically unsaturated monomers. The preferred polymerizable
acrylic
acid esters include C1 to C8-alkyl esters, for example methyl, ethyl, butyl, n-
octyl and 2-
ethylhexyl esters, haloalkyl esters, preferably halo-Ci-Cg-alkyl esters, such
as chloroethyl
acrylate, and mixtures of these monomers.
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For crosslinking, monomers having more than one polymerizable double bond can
be
copolymerized. Preferred examples of crosslinking monomers are esters of
unsaturated
monocarboxylic acids having 3 to 8 C atoms and unsaturated monohydric alcohols
having
3 to 12 C atoms, or of saturated polyols having 2 to 4 OH groups and 2 to 20 C
atoms, such
as ethylene glycol dimethacrylate and allyl methacrylate; polyunsaturated
heterocyclic
compounds, such as trivinyl and triallyl cyanurate; polyfunctional vinyl
compounds, such
as di- and trivinylbenzenes; but also triallyl phosphate and diallyl
phthalate. Preferred
crosslinking monomers are allyl methacrylate, ethylene glycol dimethacrylate,
diallyl
phthalate and heterocyclic compounds which contain at least three
ethylenically
unsaturated groups. Particularly preferred crosslinking monomers are the
cyclic monomers
triallyl cyanurate, triallyl isocyanurate, triacryloylhexahydro-s-triazine and
triallylbenzenes. The amount of the crosslinking monomers is preferably 0.02
to 5 wt.%, in
particular 0.05 to 2 wt.%, based on the graft base B.2. In the case of cyclic
crosslinking
monomers having at least three ethylenically unsaturated groups, it is
advantageous to limit
the amount to less than 1 wt.% of the graft base B.2.
Preferred "other" polymerizable ethylenically unsaturated monomers which can
optionally
serve for preparation of the graft base B.2 in addition to the acrylic acid
esters are e.g.
acrylonitrile, styrene, a-methylstyrene, acrylamides, vinyl C l -C6-alkyl
ethers, methyl
methacrylate and butadiene. Preferred acrylate rubbers as the graft base B.2
are emulsion
polymers which have a gel content of at least 60 wt.%.
Suitable silicone rubbers according to B.2 can be prepared by emulsion
polymerization, as
described, for example, in US 2891920 and US 3294725. Further suitable graft
bases
according to B.2 are silicone rubbers having grafting-active sites, such as
are described in
DE-OS 3 704 657, DE-OS 3 704 655, DE-OS 3 631 540 and DE-OS 3 631 539.
According to the invention, silicone/acrylate rubbers are also suitable as
graft bases B.2.
These silicone/acrylate rubbers are composite rubbers having grafting-active
sites
containing a silicone rubber content of 10 - 90 wt.% and a polyalkyl
(meth)acrylate rubber
content of 90 to 10 wt.%, the two rubber components mentioned penetrating each
other in
the composite rubber, so that they cannot be separated substantially from one
another. If
the content of the silicone rubber component in the composite rubber is too
high, the
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finished resin compositions have adverse surface properties and cannot be
coloured so
readily. On the other hand, if the content of the polyalkyl (meth)acrylate
rubber component
in the composite rubber is too high, the impact strength of the finished resin
composition is
adversely influenced. Silicone/acrylate rubbers are known and are described,
for example,
in US 5,807,914, EP 430134 and US 4888388. A graft polymer prepared in
emulsion
polymerization with B.1 methyl methacrylate and B.2 silicone/acrylate
composite rubber is
preferably employed.
The gel content of the graft base B.2 is determined at 25 C in a suitable
solvent (M.
Hoffmann, H. Kromer, R. Kuhn, Polymeranalytik I and II, Georg Thieme-Verlag,
Stuttgart
1977).
The average particle size d50 is the diameter above and below which in each
case 50 wt.%
of the particles lie. It can be determined by means of ultracentrifuge
measurement (W.
Scholtan, H. Lange, Kolloid, Z. and Z. Polymere 250 (1972), 782-1796).
Component C
The salt of a phosphinic acid (component C) in the context according to the
invention is to
be understood as meaning the salt of a phosphinic acid with any desired metal
cation.
Mixtures of salts which differ in their metal cation can also be employed. The
metal
cations are the cations of metals of main group 1 (alkali metals, preferably
Li+, Na+, K+), of
main group 2 (alkaline earth metals; preferably Mgt+, Cat+, Sr2+, Bat+,
particularly
preferably Cat+) or of main group 3 (elements of the boron group; preferably
A13) and/or
of subgroup 2, 7 or 8 (preferably Zn2+, Mn2+, Fee+, Fe3+) of the periodic
table.
A salt or a mixture of salts of a phosphinic acid of the formula (IV) is
preferably employed
0
11 _ M m+
H-P-O
I
H
m
(IV)
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wherein Mm+ is a metal cation of main group 1 (alkali metals; in = 1), main
group 2
(alkaline earth metals; in = 2) or of main group 3 (m = 3) or of subgroup 2, 7
or 8 (wherein
in denotes an integer from 1 to 6, preferably 1 to 3 and particularly
preferably 2 or 3) of the
periodic table.
Particularly preferably, in formula (IV)
for in = 1 the metal cations M+ = Li+, Na+, K+,
for in = 2 the metal cations M2+ = Mgt+, Cat+, Sr2+, Ba2+ and
for in = 3 the metal cations M3+ = A13+,
Ca2+ (m = 2) and A13+ (m = 3) are very preferred.
In a preferred embodiment, the average particle size d50 of the phosphinic
acid salt
(component C) is less than 80 m, preferably less than 60 m, and d50 is
particularly
preferably between 10 m and 55 m. The average particle size d50 is the
diameter above
and below which in each case 50 wt.% of the particles lie. Mixtures of salts
which differ in
their average particle size d50 can also be employed.
These requirements of the particle size d50 of the phosphinic acid salt are in
each case
associated with the technical effect that the flameproofing efficiency of the
phosphinic acid
salt is increased.
The phosphinic acid salt can be employed either by itself or in combination
with other
phosphorus-containing flameproofing agents. The compositions according to the
invention
are preferably free from phosphorus-containing flameproofing agents chosen
from the
group of mono- and oligomeric phosphoric and phosphonic acid esters,
phosphonate-
amines and phosphazenes. These other phosphorus-containing flameproofing
agents, such
as, for example, the mono- and oligomeric phosphoric and phosphonic acid
esters, have the
disadvantage compared with the phosphinic acid salts that they lower the heat
distortion
point of the moulding compositions.
Component D
Component D includes one or more thermoplastic vinyl (co)polymers D.1 and/or
polyalkylene terephthalates D.2.
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Suitable vinyl (co)polymers DA are polymers of at least one monomer from the
group of
vinylaromatics, vinyl cyanides (unsaturated nitrites), (meth)acrylic acid (C1-
C8)-alkyl
esters, unsaturated carboxylic acids and derivatives (such as anhydrides and
imides) of
unsaturated carboxylic acids. (Co)polymers which are suitable in particular
are those of
D.1.1 50 to 99 parts by wt., preferably 60 to 80 parts by wt. of
vinylaromatics and/or
vinylaromatics substituted on the nucleus, such as styrene, a-methylstyrene, p-
methylstyrene and p-chlorostyrene, and/or (meth)acrylic acid (Cl-Cg)-alkyl
esters,
such as methyl methacrylate and ethyl methacrylate, and
D.1.2 1 to 50 parts by wt., preferably 20 to 40 parts by wt. of vinyl cyanides
(unsaturated
nitrites), such as acrylonitrile and methacrylonitrile, and/or (meth)acrylic
acid (C1-
Cg)-alkyl esters, such as methyl methacrylate, n-butyl acrylate and t-butyl
acrylate,
and/or unsaturated carboxylic acids, such as maleic acid, and/or derivatives,
such as
anhydrides and imides, of unsaturated carboxylic acids, for example maleic
anhydride and N-phenylmaleimide.
The vinyl (co)polymers D.1 are resinous, thermoplastic and rubber-free. The
copolymer of
D. 1.1 styrene and D. 1.2 acrylonitrile is particularly preferred.
The (co)polymers according to D.1 are known and can be prepared by free-
radical
polymerization, in particular by emulsion, suspension, solution or bulk
polymerization.
The (co)polymers preferably have average molecular weights Mw (weight-average,
determined by light scattering or sedimentation) of between 15,000 and
200,000.
The polyalkylene terephthalates of component D.2 are reaction products of
aromatic
dicarboxylic acids or their reactive derivatives, such as dimethyl esters or
anhydrides, and
aliphatic, cycloaliphatic or araliphatic diols, and mixtures of these reaction
products.
Preferred polyalkylene terephthalates contain at least 80 wt.%, preferably at
least 90 wt.%,
based on the dicarboxylic acid component, of terephthalic acid radicals and at
least 80
wt.%, preferably at least 90 mot%, based on the diol component, of radicals of
ethylene
glycol and/or butane-l,4-diol.
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The preferred polyalkylene terephthalates can contain, in addition to
terephthalic acid
radicals, up to 20 mol%, preferably up to 10 mol% of radicals of other
aromatic or
cycloaliphatic dicarboxylic acids having 8 to 14 C atoms or aliphatic
dicarboxylic acids
having 4 to 12 C atoms, such as e.g. radicals of phthalic acid, isophthalic
acid,
naphthalene-2,6-dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, succinic
acid, adipic
acid, sebacic acid, azelaic acid and cyclohexanediacetic acid.
The preferred polyalkylene terephthalates can contain, in addition to radicals
of ethylene
glycol or butane-l,4-diol, up to 20 mol%, preferably up to 10 mol% of other
aliphatic
diols having 3 to 12 C atoms or cycloaliphatic diols having 6 to 21 C atoms,
e.g. radicals of
propane- 1,3-diol, 2-ethylpropane-1,3-diol, neopentyl glycol, pentane-1,5-
diol, hexane-1,6-
diol, cyclohexane-1,4-dimethanol, 3-ethylpentane-2,4-diol, 2-methylpentane-2,4-
diol,
2,2,4-trimethylpentane-1,3-diol, 2-ethylhexane-1,3-diol, 2,2-diethylpropane-
1,3-diol,
hexane-2,5-diol, 1,4-di-((3-hydroxyethoxy)-benzene, 2,2-bis-(4-
hydroxycyclohexyl)-
propane, 2,4-dihydroxy- 1, 1,3,3 -tetramethyl-cyclobutane, 2,2-bis-(4-j3-
hydroxyethoxy-
phenyl)-propane and 2,2-bis-(4-hydroxypropoxyphenyl)-propane (DE-A 2 407 674,
2 407 776 and 2 715 932).
The polyalkylene terephthalates can be branched by incorporation of relatively
small
amounts of 3- or 4-hydric alcohols or 3- or 4-basic carboxylic acids, e.g. in
accordance
with DE-A 1 900 270 and US 3 692 744. Examples of preferred branching agents
are
trimesic acid, trimellitic acid, trimethylolethane and -propane and
pentaerythritol.
Polyalkylene terephthalates which have been prepared solely from terephthalic
acid and
reactive derivatives thereof (e.g. dialkyl esters thereof) and ethylene glycol
and/or butane-
1,4-diol and mixtures of these polyalkylene terephthalates are particularly
preferred.
Mixtures of polyalkylene terephthalates contain I to 50 wt.%, preferably I to
30 wt.% of
polyethylene terephthalate and 50 to 99 wt.%, preferably 70 to 99 wt.% of
polybutylene
terephthalate.
The polyalkylene terephthalates preferably used in general have a limiting
viscosity of
from 0.4 to 1.5 dl/g, preferably 0.5 to 1.2 dl/g, measured in phenol/o-
dichlorobenzene (1:1
parts by weight) at 25 C in an Ubbelohde viscometer.
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The polyalkylene terephthalates can be prepared by known methods (see e.g.
Kunststoff-
Handbuch, volume VIII, p. 695 et seq., Carl-Hanser-Verlag, Munich 1973).
Component E
The composition can comprise further commercially available additives
according to
component E), such as flameproofing synergists, rubber-modified graft polymers
E* which
differ from component B), antidripping agents (for example compounds of the
substance
classes of fluorinated polyolefins, of silicones and aramid fibres),
lubricants and mould
release agents (for example pentaerythritol tetrastearate), nucleating agents,
stabilizers,
antistatics (for example conductive carbon blacks, carbon fibres, carbon
nanotubes and
organic antistatics, such as polyalkylene ethers, alkylsulfonates or polyamide-
containing
polymers), acids, fillers and reinforcing substances (for example glass fibres
or carbon
fibres, mica, kaolin, talc, CaCO3 glass flakes) and dyestuffs and pigments.
The graft polymers E* which differ from component B are prepared by bulk,
suspension or
solution polymerization. The compositions according to the invention are
preferably free
from graft polymers E* which differ from component B.
Preparation of the moulding compositions and shaped articles
The thermoplastic moulding compositions according to the invention are
prepared by
mixing the particular constituents in a known manner and subjecting the
mixture to melt
compounding and melt extrusion at temperatures of from 240 C to 300 C in
conventional
units, such as internal kneaders, extruders and twin-screw extruders.
The mixing of the individual constituents can be carried out in a known manner
either
successively or simultaneously, and in particular either at about 20 C (room
temperature)
or at a higher temperature.
The invention likewise provides processes for the preparation of the moulding
compositions and the use of the moulding compositions for the production of
shaped
articles and the mouldings themselves.
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The moulding compositions according to the invention can be used for the
production of
all types of shaped articles. These can be produced by injection moulding,
extrusion and
blow moulding processes. A further form of processing is the production of
shaped articles
by thermoforming from previously produced sheets or films.
Examples of such shaped articles are films, profiles, housing components of
all types, e.g.
for domestic appliances, such as televisions, juice presses, coffee machines
and mixers; for
office machines, such as monitors, flatscreens, notebooks, printers and
copiers; sheets,
tubes, electrical installation conduits, windows, doors and further profiles
for the building
sector (interior finishing and exterior uses) and electrical and electronic
components, such
as switches, plugs and sockets, and vehicle body or interior components for
utility vehicles,
in particular for the automobile sector.
The moulding compositions according to the invention can also be used in
particular, for
example, for the production of the following shaped articles or mouldings:
interior
finishing components for rail vehicles, ships, aircraft, buses and other motor
vehicles,
housing of electrical equipment containing small transformers, housing for
equipment for
processing and transmission of information, housing and lining of medical
equipment,
massage equipment and housing therefor, toy vehicles for children, planar wall
elements,
housing for safety equipment and for televisions, thermally insulated
transportation
containers, mouldings for sanitary and bath fittings, cover grids for
ventilator openings and
housing for garden equipment.
The following examples serve to explain the invention further.
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Examples
Component A-1
Linear polycarbonate based on bisphenol A having a relative solution viscosity
of rite! _
1.28, measured in CH2C12 as the solvent at 25 C and a concentration of 0.5
g/100 ml.
Component A-2
Linear polycarbonate based on bisphenol A having a relative solution viscosity
of lire! _
1.20, measured in CH2Cl2 as the solvent at 25 C and a concentration of 0.5
g/100 ml.
Component B
ABS graft polymer having a core-shell structure prepared by emulsion
polymerization of
43 wt.%, based on the ABS polymer, of a mixture of 27 wt.% of acrylonitrile
and 73 wt.%
of styrene in the presence of 57 wt.%, based on the ABS polymer, of a
polybutadiene
rubber crosslinked in particle form (average particle diameter d50 = 0.35 m).
Component C
Component C-1 (comparison)
Oligophosphate based on bisphenol A
O CH3 O
O-P O / \ i O-P O
O CH3 O
q=1.1
Component C-2
Calcium phosphinate, average particle size d50 = 50 m.
Component E
Component E- 1: polytetrafluoroethylene (PTFE)
Component E-2: pentaerythritol tetrastearate
Component E-3: Irganox B900 (manufacturer: Ciba Specialty Chemicals Inc.,
Basle,
Switzerland)
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Preparation and testing of the moulding compositions
The starting substances listed in Table 1 are compounded and granulated on a
twin-screw
extruder (ZSK-25) (Werner and Pfleiderer) at a speed of rotation of 225 rpm
and a
throughput of 20 kg/h at a machine temperature of 260 C.
The finished granules are processed on an injection moulding machine to give
the
corresponding test specimens (melt temperature 260 C, mould temperature 80
C, melt
front speed 240 mm/s).
Characterization is carried out in accordance with DIN ISO 306 (Vicat
softening
temperature, method B with a load of 50 N and a heating rate of 120 K/h), ISO
4599
(environmental stress cracking (ESC) test against toluene:isopropanol 60:40,
at 2.4 % and
0.8 % edge fibre elongation, in the table the time until break is stated) UL
94 V (measured
on bars of dimensions 127 x 12.7 x 1.5 mm) and IEC 60695-2-12 (glow wire test;
the glow
wire flammability index GWFI at a thickness of 2.0 mm is stated).
It can be seen from Table 1 that only the composition in Example 2 with the
combination
of polycarbonate, emulsion ABS and calcium phosphinate achieves the object
according to
the invention, i.e. a combination of high heat distortion point, good
resistance to chemicals
and good performance in the UL94V test and in the test according to JEC 60695-
2-12.
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Table 1: Compositions and their properties
Composition 1 2
(comp.)
A-1 pt. by wt. 70.2 70.2
A-2 pt. by wt. 24.5 24.5
B pt. by wt. 3.0 3.0
C-1 pt. by wt. 2.3
C-2 pt. by wt. 2.3
E-1 pt. by wt. 0.4 0.4
E-2 pt. by wt. 0.4 0.4
E-3 pt. by wt. 0.1 0.1
Properties
Vicat B 120 (DIN ISO 306) C 100 102
ESC properties / [2.4 %] min:sec 10 19
ESC properties / [0.8%] min:sec 220 265
UL 94 V 1.5 mm / 2 d [rating] vi v o
UL 94 V 1.5 mm / 2 d [total
ABT] s 33 6
Glow wire flammability index 800 960
GWFI at a thickness of 2.0 mm
ABT = after-burn time
