Note: Descriptions are shown in the official language in which they were submitted.
FLAME RETARDANT POLYAMIDE COMPOSITIONS WITH LIGHT COLOURING
Description
The present invention relates to thermoplastic molding compositions comprising
A) from 10 to 99.8% by weight of a thermoplastic polyamide,
B) from 0.1 to 60% by weight of red phosphorus,
C) from 0.01 to 4% by weight of a Cu(I) salt or Ag(I) oxide or Cu(I)
complex or Ag(I) salt or
Cu(I) oxide or Ag(I) complex, or a mixture of these,
D) from 0 to 40% by weight of an impact modifier, and
E) from 0 to 60% by weight of further additional substances,
where the total of the percentages by weight of A) to E) is 100%.
The invention further relates to the use of Cu(I) compounds and/or Ag(I)
compounds for the
production of PA molding compositions, with particular color values, and also
with improved
UV resistance, and also with reduced phosphine emission.
The present invention also relates to the use of molding compositions of this
type for the
production of fibers, foils, and moldings, and to the resultant moldings,
fibers, and foils of any
type.
It is known that addition of red phosphorus to thermoplastics, especially to
reinforced or filled
polyamides, leads to effective fire protection (DE-A-1931387). However, under
unfavorable
conditions, e.g. increased temperature or moisture, or presence of alkali or
oxygen, red
phosphorus tends to form decomposition products, such as phosphine and acids
of mono- to
pentavalent phosphorus. Although red phosphorus incorporated within
thermoplastics, e.g.
polyamides, has substantial protection from thermooxidation because of
embedding into the
polymer, decomposition products can nevertheless be formed in the relatively
long term even
in these instances. This is disadvantageous insofar as if pellets are
incorrectly processed in
the injection-molding process the resultant phosphine can cause unpleasant
odor, and
moreover is toxic. The phosphorus acids arising at the same time can deposit
on the surface
of moldings, a particular result of this being that the tracking resistance of
the moldings is
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reduced. There has therefore been no lack of attempts to improve the stability
of the red
phosphorus used as flame retardant for plastics.
A stabilizing effect can be achieved for polyamide by adding oxides or
hydroxides of zinc, of
magnesium, or of copper, see by way of example W02000/22035 (heat-aging
resistance
provided by Cu compounds and complexes in polyamides), EP1211220 (coating of
red
phosphorus with metallic silver), EP-A-283 759 (phlegmatization of phosphorus
with Sn oxide
hydrate and MF resins), DE-A-10332852 (coating of red phosphorus with white
pigments
based on TiO2 and MF resins).
However, molding compositions known from the prior art have an undesired
reddish intrinsic
color, with corresponding difficulty in achieving color for pale and gray
applications. UV
resistance is unsatisfactory.
Furthermore, flame-retardant compounded polyamide materials using red
phosphorus
release small amounts of phosphine - specifically during processing. Phosphine
is firstly toxic
and secondly causes formation of contact deposits on metallic conductors. In
order to
stabilize the phosphorus, an acid scavenger is added to the compounded
polyamide material
in order to prevent the acid-catalyzed disproportionation of the phosphorus to
give
phosphine. However, there is no resultant lasting prevention of phosphine
evolution/complexing.
It was therefore an object of the present invention to provide polyamides
rendered
flame-retardant by using red phosphorus and exhibiting little reddish
intrinsic color, improved
ease of achieving color for pale and gray applications, better UV resistance,
and relatively
little phosphine formation.
Accordingly, the molding compositions defined in the introduction have been
found. It has
been found that the addition of small amounts of Cu(I) compounds and/or Ag(I)
compounds
to flame-retardant compounded polyamide materials based on red phosphorus
leads to a
color change from red to gray coloration of the compounded material.
Surprisingly, the
resultant color does not change when irradiated with (UV) light, and it is
therefore suitable for
pale colorations. It has moreover been found that the addition of the
compounds of the
invention leads to a great reduction in the release of phosphine from the
flame-retardant
compounded polyamide materials.
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=
The molding compositions of the invention comprise, as component A), from 10
to 98% by
weight, preferably from 20 to 98% by weight, and in particular from 30 to 90%
by weight, of at
least one polyamide.
The polyamides of the molding compositions of the invention generally have an
intrinsic
viscosity of from 90 to 350 ml/g, preferably from 110 to 240 ml/g, determined
in a 0.5%
strength by weight solution in 96% strength by weight sulfuric acid at 25 C to
ISO 307.
Preference is given to semicrystalline or amorphous resins with a molecular
weight (weight
average) of at least 5000, described by way of example in the following US
patents: 2 071
250, 2 071 251, 2 130 523, 2 130 948, 2 241 322, 2 312 966, 2 512 606, and 3
393 210.
Examples of these are polyamides that derive from lactams having from 7 to 13
ring
members, e.g. polycaprolactam, polycaprylolactam, and polylaurolactam, and
also
polyamides obtained via reaction of dicarboxylic acids with diamines.
Dicarboxylic acids which may be used are alkanedicarboxylic acids having 6 to
12, in
particular 6 to 10, carbon atoms, and aromatic dicarboxylic acids. Merely as
examples, those
that may be mentioned here are adipic acid, azelaic acid, sebacic acid,
dodecanedioic acid
and terephthalic and/or isophthalic acid.
Particularly suitable diamines are alkanediamines having from 6 to 12, in
particular from 6 to
8, carbon atoms, and also m-xylylenediamine (e.g. Ultramide X17 from BASF SE,
where the
molar ratio of MXDA to adipic acid is 1:1), di(4-aminophenyl)methane,
di(4-aminocyclohexyl)methane, 2,2-di(4-aminophenyl)propane, 2,2-di(4-
aminocyclohexyl)-
propane, and 1,5-diamino-2-methylpentane.
Preferred polyamides are polyhexamethyleneadipamide,
polyhexamethylenesebacamide,
and polycaprolactam, and also nylon-6/6,6 copolyamides, in particular having a
proportion of
from 5 to 95% by weight of caprolactam units (e.g. Ultramid C31 from BASF
SE).
Other suitable polyamides are obtainable from w-aminoalkylnitriles, e.g.
aminocapronitrile
(PA 6) and adipodinitrile with hexamethylenediamine (PA 66) via what is known
as direct
polymerization in the presence of water, for example as described in DE-A
10313681, EP-A
1198491 and EP 922065.
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Mention may also be made of polyamides obtainable, by way of example, via
condensation
of 1,4-diaminobutane with adipic acid at an elevated temperature (nylon-4,6).
Preparation
processes for polyamides of this structure are described by way of example in
EP-A 38 094,
EP-A 38 582, and EP-A 39 524.
Other suitable examples are polyamides obtainable via copolymerization of two
or more of
the abovementioned monomers, and mixtures of two or more polyamides in any
desired
mixing ratio. Particular preference is given to mixtures of nylon-6,6 with
other polyamides, in
particular nylon-6/6,6 copolyamides.
Other copolyamides which have proven particularly advantageous are
semiaromatic
copolyamides, such as PA 6/6T and PA 66/6T, where the triamine content of
these is less
than 0.5% by weight, preferably less than 0.3% by weight (see EP¨A 299 444).
Other
polyamides resistant to high temperatures are known from EP-A 19 94 075
(PA 6T/6I/MXD6).
The processes described in EP-A 129 195 and 129 196 can be used to prepare the
preferred
semiaromatic copolyamides with low triamine content.
The following list, which is not comprehensive, comprises the polyamides A)
mentioned and
other polyamides A) for the purposes of the invention, and the monomers
comprised:
AB polymers:
PA 4 Pyrrolidone
PA 6 c-Caprolactam
PA 7 Ethanolactam
PA 8 Caprylolactam
PA 9 9-Aminopelargonic acid
PA 11 11-Aminoundecanoic acid
PA 12 Laurolactam
AA/BB polymers:
PA 46 Tetramethylenediamine, adipic acid
PA 66 Hexamethylenediamine, adipic acid
PA 69 Hexamethylenediamine, azelaic acid
PA 610 Hexamethylenediamine, sebacic acid
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PA 612 Hexamethylenediamine, decanedicarboxylic acid
PA 613 Hexamethylenediamine, undecanedicarboxylic acid
PA 1212 1,12-Dodecanediamine, decanedicarboxylic acid
PA 1313 1,13-Diaminotridecane, undecanedicarboxylic acid
PA 6T Hexamethylenediamine, terephthalic acid
PA 9T 1,9-Nonanediamine, terephthalic acid
PA MXD6 m-Xylylenediamine, adipic acid
PA 61 Hexamethylenediamine, isophthalic acid
PA 6-3-T Trimethylhexamethylenediamine, terephthalic acid
PA 6/6T (see PA 6 and PA 6T)
PA 6/66 (see PA 6 and PA 66)
PA 6/12 (see PA 6 and PA 12)
PA 66/6/610 (see PA 66, PA 6 and PA 610)
PA 6I/6T (see PA 61 and PA 61)
PA PACM 12 Diaminodicyclohexylmethane, laurolactam
PA 6I/6T/PACM as PA 6I/6T + diaminodicyclohexylmethane
PA 12/MACMI Laurolactam, dimethyldiaminodicyclohexylmethane, isophthalic
acid
PA 12/MACMT Laurolactam, dimethyldiaminodicyclohexylmethane, terephthalic acid
PA PDA-T Phenylenediamine, terephthalic acid
Preferred flame retardant B) is elemental red phosphorus, in particular in
combination with
glassfiber-reinforced molding compositions; it can be used in untreated form.
However, particularly suitable preparations are those in which the phosphorus
has been
surface-coated with low-molecular-weight liquid substances, such as silicone
oil, paraffin oil,
or esters of phthalic acid (in particular dioctyl phthalate, see EP 176 836)
or adipic acid, or
with polymeric or oligomeric compounds, e.g. with phenolic resins or amino
plastics, or else
with polyurethanes (see EP-A 384 232, DE-A 196 48 503). The amounts comprised
of these
"phlegmatizing agents" are generally from 0.05 to 5% by weight, based on 100%
by weight of
B).
Concentrates of red phosphorus, e.g. in a polyamide or elastomer, are moreover
suitable as
flame retardants. In particular, polyolefin homo- and copolymers are suitable
as concentrate
polymers. However, unless polyamide is used as thermoplastic, the proportion
of the
CA 2884863 2019-10-25
concentrate polymer should not amount to more than 35% by weight, based on the
weight of
components A) and B) in the molding compositions of the invention.
Preferred concentrate compositions are
B1) from 30 to 90% by weight, preferably from 45 to 70% by weight, of a
polyamide or
elastomer, and
B2) from 10 to 70% by weight, preferably from 30 to 55% by weight, of red
phosphorus.
The polyamide used for the masterbatch can differ from A) or preferably can be
the same as
A), in order to avoid any incompatibility or melting point difference having
an adverse effect
on the molding composition.
In another process for incorporating the additives C) of the invention, the
red phosphorus is
suspended in an aqueous solution or suspension of the appropriate additive.
This is followed
by filtering, washing with water, and drying of the phosphorus thus obtained
and surface-
wetted with the respective additive C), and drying under inert gas. The
modified phosphorus
can then be incorporated into thermoplastic molding compositions by using
suitable
processing machines.
The average particle size (d50) of the phosphorus particles dispersed in the
molding
compositions is preferably in the range from 0.0001 to 0.5 mm; in particular
from 0.001 to
0.2 mm.
The content of component B) in the molding compositions of the invention is
from 0.1 to 60%
by weight, preferably from 0.5 to 40% by weight, and in particular from 1 to
15% by weight,
based on the entirety of components A) to E).
The molding compositions of the invention comprise, as component C), from 0.01
to 4% by
weight, preferably from 0.1 to 3% by weight, and in particular from 0.1 to 2%
by weight, and
very particularly preferably from 0.1 to 1.5% by weight, of a Cu(I) salt or
Ag(I) oxide or Cu(I)
complex or Ag(I) salt or Cu(I) oxide or Ag(I) complex, or a mixture of these.
Suitable Cu(I) complexes or Ag(I) complexes comprise, as ligands,
triphenylphosphines,
mercaptobenzimidazoles, EDTA, acetylacetonates, glycine, ethylenediamines,
oxalates,
diethylenetriamines, triethylenetetramines, pyridines, diphosphones and
dipyridyls.
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These ligands can be used individually or in combination for complex
formation. The
syntheses required for this purpose are known to the person skilled in the art
or are
described in the technical literature relating to chemistry of complexes.
These complexes
can, as usual, also comprise typical inorganic ligands, such as water,
chloride, cyano
ligands, etc, alongside the abovementioned ligands.
Preference is given to copper complexes with the following ligands in the
complex:
triphenylphosphines, mercaptobenzimidazoles, acetylacetonates, and glycine.
Particular
preference is given to triphenylphosphines and mercaptobenzimidazoles.
Preferred copper complexes used in the invention are usually formed via
reaction of
copper(I) ions with the phosphine compounds and, respectively,
mercaptobenzimidazole
compounds. These complexes can by way of example be obtained via reaction of
triphenylphosphine with a copper(I) halide suspended in chloroform (G. Kosta,
E. Reisenhofer, and L. Stafani, J. lnorg. Nukl. Chem. 27 (1965) 2581).
However, it is also
possible to carry out a reductive reaction of copper(II) compounds with
triphenylphosphine,
and thus obtain the copper(I) adducts (F. U. Jardine, L. Rule, A. G. Vohrei,
J. Chem. Soc. (A)
238-241 (1970)). The person skilled in the art is aware of other processes.
In principle, all alkyl- or arylphosphines are suitable. Examples of
phosphines that can be
used in the invention are triphenylphosphine, and also the substituted
triphenylphosphines,
trialkylphosphines, and also diarylphosphines. An example of a suitable
trialkylphosphine is
tris(n-butyl)phosphine. Triphenylphosphine is especially preferred for
economic reasons
because of its commercial availability. However, the triphenylphosphine
complexes are
generally more stable than the trialkylphosphine complexes.
Examples of suitable complexes can be represented by the following formulae:
[Cu(PPh3)3X], [Cu2X2(PPh3)3], [Cu(PPh3)X]4, and also [Cu(PPh3)2X], where X is
selected from
Cl, Br, I, CN, SCN, or 2-mercaptobenzimidazole, particular preference being
given here to
Cu(I)(PPh3)21.
However, complexes that can be used in the invention can also comprise further
ligands in
the complex. Examples here are bipyridyl (e.g. CuX (PPh3) (bipy), where X is
Cl, Br, or l),
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biquinoline (e.g. CuX (PPh3) (biquin), where Xis CI, Br, or l), and also 1,10-
phenanthroline,
o-phenylenebis(dimenthylarsine), 1,2-bis(diphenylphosphino)ethane, and
terpyridyl.
Other preferred compounds of Cu and Ag in the oxidation state I are the oxides
Cu2O, Ag2O,
thiocyanates CuSCN, AgSCN, halides CuF, CuCI, AgCI, CuBr, AgBr, preference
being given
here to Cul, Agl, CuSCN, and/or CuCl.
Carboxylates of monovalent copper or silver that can be used, in particular
having from 1 to 6
carbon atoms, are preferably acetates, oxalates, stearates, propionates,
butyrates, or
benzoates, preference being given here to acetates and/or oxalates.
It is particularly preferable that component C) is present in a mixture with
an alkali metal
halide, preferably KI, where the mixing ratio is from 1:10 to 1:1.
Very particularly preferred Cu compounds C) alongside the oxides are Cul, in
particular in a
mixture with KI in the ratio 1:4, and bistriphenylphosphinecopper iodide, in
particular in a
mixture with KI in the ratio 1:2.
Very particularly preferred Ag compounds C) are moreover Ag2O and/or AgCl.
Very particularly, the alkali metal halide is potassium bromide or potassium
iodide, or a
mixture of these.
The molding compositions comprise, as component D), amounts of from 0 to 40%
by weight,
preferably from 1 to 30% by weight, in particular from 2 to 20% by weight, of
elastomeric
polymers (often also termed impact modifiers, elastomers, or rubbers).
These materials very generally involve copolymers, preferably composed of at
least two of
the following monomers: ethylene, propylene, butadiene, isobutene, isoprene,
chloroprene,
vinyl acetate, styrene, acrylonitrile, and (meth)acrylates having from 1 to 18
carbon atoms in
the alcohol component.
Polymers of this type are described by way of example in Houben-Weyl, Methoden
der
organischen Chemie, volume 14/1 (Georg-Thieme-Verlag, Stuttgart, 1961), pp 392
to 406,
and in the monograph "Toughened Plastics" by C.B. Bucknall (Applied Science
Publishers,
London, 1977).
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Some preferred types of these elastomers are described below.
Preferred types of these elastomers are those known as ethylene-propylene
(EPM) and
ethylene-propylene-diene (EPDM) rubbers.
EPM rubbers generally have practically no residual double bonds, whereas EPDM
rubbers
may have from 1 to 20 double bonds per 100 carbon atoms.
Examples which may be mentioned of diene monomers for EPDM rubbers are
conjugated
dienes, such as isoprene and butadiene, non-conjugated dienes having from 5 to
25 carbon
atoms, such as 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 2,5-dimethy1-1,5-
hexadiene
and 1,4-octadiene, cyclic dienes, such as cyclopentadiene, cyclohexadienes,
cyclooctadienes and dicyclopentadiene, and also alkenylnorbornenes, such as 5-
ethylidene-
2-norbornene, 5-butylidene-2-norbornene, 2-methallyI-5-norbornene and 2-
isopropeny1-5-
norbornene, and tricyclodienes, such as 3-methyltricyclo[5.2.1Ø2.6]-3,8-
decadiene, and
mixtures of these. Preference is given to 1,5-hexadiene, 5-
ethylidenenorbornene and
dicyclopentadiene. The diene content of the EPDM rubbers is preferably from
0.5 to 50% by
weight, in particular from 1 to 8% by weight, based on the total weight of the
rubber.
EPM rubbers and EPDM rubbers may preferably also have been grafted with
reactive
carboxylic acids or with derivatives of these. Examples of these are acrylic
acid, methacrylic
acid and derivatives thereof, e.g. glycidyl (meth)acrylate, and also maleic
anhydride.
Copolymers of ethylene with acrylic acid and/or methacrylic acid and/or with
the esters of
these acids are another group of preferred rubbers. The rubbers may also
comprise
dicarboxylic acids, such as maleic acid and fumaric acid, or derivatives of
these acids, e.g.
esters and anhydrides, and/or monomers comprising epoxy groups. These monomers
comprising dicarboxylic acid derivatives or comprising epoxy groups are
preferably
incorporated into the rubber by adding to the monomer mixture monomers
comprising
dicarboxylic acid groups and/or epoxy groups and having the general formulae 1
or II or III or
Iv
R1C(COOR2)=C(COOR3)R4 (1)
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RI\ zR4
(II)
OC CO
0
0
CH R7=CH (CH2)m ¨ 0¨ (CHR6)g ¨CH ¨ CH R6 (III)
CH2=-- CR9¨ COO ¨ (¨CH2)g¨ CH ¨CI-1W (IV)
0
where R' to R9 are hydrogen or alkyl groups having from 1 to 6 carbon atoms,
and m is a
whole number from 0 to 20, g is a whole number from 0 to 10 and p is a whole
number from
0 to 5.
The radicals R1 to R9 are preferably hydrogen, where m is 0 or 1 and g is 1.
The
corresponding compounds are maleic acid, fumaric acid, maleic anhydride, ally'
glycidyl
ether and vinyl glycidyl ether.
Preferred compounds of the formulae I, II and IV are maleic acid, maleic
anhydride and
(meth)acrylates comprising epoxy groups, such as glycidyl acrylate and
glycidyl
methacrylate, and the esters with tertiary alcohols, such as tert-butyl
acrylate. Although the
latter have no free carboxy groups, their behavior approximates to that of the
free acids and
they are therefore termed monomers with latent carboxy groups.
The copolymers are advantageously composed of from 50 to 98% by weight of
ethylene,
from 0.1 to 20% by weight of monomers comprising epoxy groups and/or
methacrylic acid
and/or monomers comprising anhydride groups, the remaining amount being
(meth)acrylates.
CA 2884863 2019-10-25
Particular preference is given to copolymers composed of
from 50 to 98% by weight, in particular from 55 to 95% by weight, of ethylene,
from 0.1 to 40% by weight, in particular from 0.3 to 20% by weight, of
glycidyl acrylate and/or
glycidyl methacrylate, (meth)acrylic acid and/or maleic anhydride, and
from 1 to 45% by weight, in particular from 5 to 40% by weight, of n-butyl
acrylate and/or 2-
ethylhexyl acrylate.
Other preferred (meth)acrylates are the methyl, ethyl, propyl, isobutyl and
tert-butyl esters.
Comonomers which may be used alongside these are vinyl esters and vinyl
ethers.
The ethylene copolymers described above may be produced by processes known per
se,
preferably by random copolymerization at high pressure and elevated
temperature.
Appropriate processes are well-known.
Other preferred elastomers are emulsion polymers whose preparation is
described, for
example, in Blackley's monograph "Emulsion Polymerization". The emulsifiers
and catalysts
which can be used are known per se.
In principle it is possible to use homogeneously structured elastomers or else
those with a
shell structure. The shell-type structure is determined by the sequence of
addition of the
individual monomers. The morphology of the polymers is also affected by this
sequence of
addition.
Monomers which may be mentioned here, merely as examples, for the preparation
of the
rubber fraction of the elastomers are acrylates, such as n-butyl acrylate and
2-ethylhexyl
acrylate, corresponding methacrylates, butadiene and isoprene, and also
mixtures of these.
These monomers may be copolymerized with other monomers, such as styrene,
acrylonitrile,
vinyl ethers and with other acrylates or methacrylates, such as methyl
methacrylate, methyl
acrylate, ethyl acrylate or propyl acrylate.
The soft or rubber phase (with a glass transition temperature of below 0 C) of
the elastomers
may be the core, the outer envelope or an intermediate shell (in the case of
elastomers
whose structure has more than two shells). Elastomers having more than one
shell may also
have more than one shell composed of a rubber phase.
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If one or more hard components (with glass transition temperatures above 20 C)
are
involved, besides the rubber phase, in the structure of the elastomer, these
are generally
produced by polymerizing, as principal monomers, styrene, acrylonitrile,
methacrylonitrile, a-
methylstyrene, p-methylstyrene, or acrylates or methacrylates, such as methyl
acrylate, ethyl
acrylate or methyl methacrylate. Besides these, it is also possible to use
relatively small
proportions of other comonomers.
It has proven advantageous in some cases to use emulsion polymers which have
reactive
groups at their surfaces. Examples of groups of this type are epoxy, carboxy,
latent carboxy,
amino and amide groups, and also functional groups which may be introduced by
concomitant use of monomers of the general formula
R11
=
CH2-C
0
where the substituents can be defined as follows:
Rlo is hydrogen or a 01-C4-alkyl group,
R11 is hydrogen, a C1-C8-alkyl group or an aryl group, in particular
phenyl,
R12 is hydrogen, a Cl-Cio-alkyl group, a C6-C12-aryl group, or -0R13,
R13 is a 01-08-alkyl group or a 06-C12-aryl group, which can optionally
have substitution by
groups that comprise 0 or by groups that comprise N,
X is a chemical bond, a C1-010-alkylene group, or a 06-012-arylene group,
or
0
¨C
Y is O-Z or NH-Z, and
Z is a 01-C10-alkylene or C6-012-arylene group.
The graft monomers described in EP-A 208 187 are also suitable for introducing
reactive
groups at the surface.
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Other examples which may be mentioned are acrylamide, methacrylamide and
substituted
acrylates or methacrylates, such as (N-tert-butylamino)ethyl methacrylate,
(N,N-
dimethylamino)ethyl acrylate, (N,N-dimethylamino)methyl acrylate and
(N,N-diethylamino)ethyl acrylate.
The particles of the rubber phase may also have been crosslinked. Examples of
crosslinking
monomers are 1,3-butadiene, divinylbenzene, diallyl phthalate and
dihydrodicyclopentadienyl
acrylate, and also the compounds described in EP-A 50 265.
It is also possible to use the monomers known as graft-linking monomers, i.e.
monomers
having two or more polymerizable double bonds which react at different rates
during the
polymerization. Preference is given to the use of compounds of this type in
which at least
one reactive group polymerizes at about the same rate as the other monomers,
while the
other reactive group (or reactive groups), for example, polymerize(s)
significantly more
slowly. The different polymerization rates give rise to a certain proportion
of unsaturated
double bonds in the rubber. If another phase is then grafted onto a rubber of
this type, at
least some of the double bonds present in the rubber react with the graft
monomers to form
chemical bonds, i.e. the phase applied by grafting has at least some degree of
chemical
bonding to the graft base.
Examples of graft-linking monomers of this type are monomers comprising allyl
groups, in
particular allyl esters of ethylenically unsaturated carboxylic acids, for
example allyl acrylate,
allyl methacrylate, diallyl maleate, diallyl fumarate and diallyl itaconate,
and the
corresponding monoallyl compounds of these dicarboxylic acids. Besides these
there is a
wide variety of other suitable graft-linking monomers. For further details
reference may be
made here, for example, to US patent 4 148 846.
The proportion of these crosslinking monomers in the impact-modifying polymer
is generally
up to 5% by weight, preferably not more than 3% by weight, based on the impact-
modifying
polymer.
Some preferred emulsion polymers are listed below. Mention may first be made
here of graft
polymers with a core and with at least one outer shell, and having the
following structure:
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Type Monomers for the core Monomers for the envelope
1,3-butadiene, isoprene, n-butyl styrene, acrylonitrile, methyl
acrylate, ethylhexyl acrylate, or a methacrylate
mixture of these
II as I, but with concomitant use of as I
crosslinking agents
Ill as I or II n-butyl acrylate, ethyl acrylate,
methyl
acrylate, 1,3-butadiene, isoprene,
ethylhexyl acrylate
IV as I or II as I or III, but with concomitant
use of
monomers having reactive groups, as
described herein
V styrene, acrylonitrile, methyl first envelope composed of monomers
methacrylate, or a mixture of these as described under I and ll for the
core,
second envelope as described under I
or IV for the envelope
Instead of graft polymers whose structure has more than one shell, it is also
possible to use
homogeneous, i.e. single-shell, elastomers composed of 1,3-butadiene, isoprene
and n-butyl
acrylate or of copolymers of these. These products, too, may be produced by
concomitant
use of crosslinking monomers or of monomers having reactive groups.
Examples of preferred emulsion polymers are n-butyl acrylate-(meth)acrylic
acid copolymers,
n-butyl acrylate-glycidyl acrylate or n-butyl acrylate-glycidyl methacrylate
copolymers, graft
polymers with an inner core composed of n-butyl acrylate or based on butadiene
and with an
outer envelope composed of the abovementioned copolymers, and copolymers of
ethylene
with comonomers which supply reactive groups.
The elastomers described may also be produced by other conventional processes,
e.g. by
suspension polymerization.
Preference is also given to silicone rubbers, as described in DE-A 37 25 576,
EP-A 235 690,
DE-A 38 00 603 and EP-A 319 290.
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Particularly preferred rubbers D) are ethylene copolymers as described above
which
comprise functional monomers, where the functional monomers are those selected
from the
group of the carboxylic acid, carboxylic anhydride, carboxylic ester,
carboxamide,
carboximide, amino, hydroxy, epoxy, urethane, or oxazoline groups, or a
mixture of these.
The content of the functional groups is from 0.1 to 20% by weight, preferably
from 0.2 to 10%
by weight, and in particular from 0.3 to 7% by weight, based on 100% by weight
of D).
Particularly preferred monomers are those composed of an ethylenically
unsaturated
mono- or dicarboxylic acid or of a functional derivative of such an acid.
In principle, any of the primary, secondary, or tertiary C1-C18-alkyl
(meth)acrylates is suitable,
but preference is given to esters having from 1 to 12 carbon atoms, in
particular having from
2 to 10 carbon atoms.
Examples here are methyl, ethyl, propyl, n-butyl, isobutyl and tert-butyl, 2-
ethylhexyl, octyl
and decyl acrylates, and the corresponding methacrylates. Among these,
particular
preference is given to n-butyl acrylate and 2-ethylhexyl acrylate.
The olefin polymers can also comprise, instead of the esters, or in addition
to these, acid-
functional and/or latently acid-functional monomers of ethylenically
unsaturated mono- or
dicarboxylic acids, or monomers having epoxy groups.
Other examples of monomers that may be mentioned are acrylic acid, methacrylic
acid,
tertiary alkyl esters of these acids, in particular tert-butyl acrylate, and
dicarboxylic acids,
such as maleic acid and fumaric acid, and derivatives of said acids, and also
monoesters of
these.
Latently acid-functional monomers are compounds which, under the conditions of
polymerization or during incorporation of the olefin polymers into the molding
compositions,
form free acid groups. Examples that may be mentioned here are anhydrides of
dicarboxylic
acids having up to 20 carbon atoms, in particular maleic anhydride, and
tertiary C1-C12-alkyl
esters of the abovementioned acids, in particular tert-butyl acrylate and tert-
butyl
methacrylate.
CA 2884863 2019-10-25
The acid-functional or latently acid-functional monomers and the monomers
comprising
epoxy groups are preferably incorporated into the olefin polymers through
addition of
compounds of the general formulae I-IV to the monomer mixture.
The melt index of the ethylene copolymers is generally in the range from 1 to
80 g/10 min
(measured at 190 C with 2.16 kg load).
The molar mass of said ethylene-a-olefin copolymers is from 10 000 to 500 000
g/mol,
preferably from 15 000 to 400 000 g/mol (Mn, determined by means of GPO in
1,2,4-
trichlorobenzene with PS calibration).
One particular embodiment uses ethylene-a-olefin copolymers produced by means
of "single
site catalysts". Further details can be found in US 5,272,236. In this case,
the ethylene-a-
olefin copolymers have a molecular weight distribution which is narrow for
polyolefins:
smaller than 4, and preferably smaller than 3.5.
Preferred commercially available products B used are Exxelor VA 1801, or
1803, Kraton
G 1901 FX, or Fusabond N NM493 D, or Fusabond A560 from Exxon, Kraton, and
DuPont,
and also Tafmer MH 7010 from Mitsui.
It is also possible, of course, to use a mixture of the types of rubber listed
above.
The molding compositions of the invention can comprise, as component E), up to
60% by
weight, preferably up to 50% by weight, of further additional substances.
Fibrous or particulate fillers E) that may be mentioned are carbon fibers,
glass fibers, glass
beads, amorphous silica, calcium silicate, calcium metasilicate, magnesium
carbonate,
kaolin, chalk, powdered quartz, mica, barium sulfate, and feldspar, and the
amounts of these
that can be used are from 1 to 50% by weight, in particular from 5 to 40% by
weight,
preferably from 10 to 40% by weight.
Preferred fibrous fillers that may be mentioned are carbon fibers, aramid
fibers, and
potassium titanate fibers, particular preference being given to glass fibers
in the form of E
glass. These can be used as rovings or in the commercially available forms of
chopped
glass.
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The fibrous fillers may have been surface-pretreated with a silane compound to
improve
compatibility with the thermoplastics.
Suitable silane compounds have the general formula:
(X¨(CH2)n)k¨Si¨(0¨CmH2m,i)4-k
where the definitions of the substituents are as follows:
X NH-, CH2-CH-, HO-,
n is a whole number from 2 to 10, preferably 3 to 4,
m is a whole number from 1 to 5, preferably 1 to 2, and
k is a whole number from 1 to 3, preferably 1.
Preferred silane compounds are aminopropyltrimethoxysilane,
aminobutyltrimethoxysilane,
aminopropyltriethoxysilane and anninobutyltriethoxysilane, and also the
corresponding
silanes which comprise a glycidyl group as substituent X.
The amounts of the silane compounds generally used for surface-coating are
from 0.01 to
2% by weight, preferably from 0.025 to 1.0% by weight and in particular from
0.05 to 0.5% by
weight (based on E)).
Acicular mineral fillers are also suitable.
For the purposes of the invention, acicular mineral fillers are mineral
fillers with strongly
developed acicular character. An example is acicular wollastonite. The mineral
preferably
has an L/D (length to diameter) ratio of from 8:1 to 35:1, preferably from 8:1
to 11:1. The
mineral filler may, if appropriate, have been pretreated with the
abovementioned silane
compounds, but the pretreatment is not essential.
Other fillers which may be mentioned are kaolin, calcined kaolin,
wollastonite, talc and chalk,
and also lamellar or acicular nanofillers, the amounts of these preferably
being from 0.1 to
10%. Materials preferred for this purpose are boehmite, bentonite,
montmorillonite,
vermiculite, hectorite, and laponite. The lamellar nanofillers are organically
modified by
17
CA 2884863 2019-10-25
prior-art methods, to give them good compatibility with the organic binder.
Addition of the
lamellar or acicular nanofillers to the inventive nanocomposites gives a
further increase in
mechanical strength.
The molding compositions of the invention can comprise, as component E), from
0.05 to 3%
by weight, preferably from 0.1 to 1.5% by weight, and in particular from 0.1
to 1% by weight,
of a lubricant.
Preference is given to the salts of Al, of alkali metals, or of alkaline earth
metals, or esters or
amides of fatty acids having from 10 to 44 carbon atoms, preferably having
from 12 to 44
carbon atoms.
The metal ions are preferably alkaline earth metal and Al, particular
preference being given
to Ca or Mg.
Preferred metal salts are Ca stearate and Ca montanate, and also Al stearate.
It is also possible to use a mixture of various salts, in any desired mixing
ratio.
The carboxylic acids can be monobasic or dibasic. Examples which may be
mentioned are
pelargonic acid, palmitic acid, lauric acid, margaric acid, dodecanedioic
acid, behenic acid,
and particularly preferably stearic acid, capric acid, and also montanic acid
(a mixture of fatty
acids having from 30 to 40 carbon atoms).
The aliphatic alcohols can be monohydric to tetrahydric. Examples of alcohols
are n-butanol,
n-octanol, stearyl alcohol, ethylene glycol, propylene glycol, neopentyl
glycol, pentaerythritol,
preference being given to glycerol and pentaerythritol.
The aliphatic amines can be mono- to tribasic. Examples of these are
stearylamine,
ethylenediamine, propylenediamine, hexamethylenediamine, di(6-
aminohexyl)amine,
particular preference being given to ethylenediamine and hexamethylenediamine.
Preferred
esters or amides are correspondingly glycerol distearate, glycerol
tristearate,
ethylenediamine distearate, glycerol monopalmitate, glycerol trilaurate,
glycerol
monobehenate, and pentaerythritol tetrastearate.
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CA 2884863 2019-10-25
It is also possible to use a mixture of various esters or amides, or of esters
with amides in
combination, in any desired mixing ratio.
The molding compositions of the invention can comprise, as component E),
amounts of from
0.01 to 2% by weight, preferably from 0.1 to 1.5% by weight, of what are known
as acid
scavengers for the red phosphorus.
Suitable acid scavengers are ZnO, Zn borate, Zn stannate, MgO, Mg(OH)2, ZnCO3,
MgCO3,
CaCO3, Mg Ca carbonates, and A100H, particular preference being given here to
ZnO, basic
ZnCO3, Mg(OH)2, and CaCO3.
Suitable sterically hindered phenols E) are in principle all of the compounds
which have a
phenolic structure and which have at least one bulky group on the phenolic
ring.
Examples of compounds that can be used with preference are those of the
formula
R2 R3
HO 40
R1
where:
R1 and R2 are an alkyl group, a substituted alkyl group, or a substituted
triazole group, and
where the radicals R1 and R2 may be identical or different, and R3 is an alkyl
group, a
substituted alkyl group, an alkoxy group, or a substituted amino group.
Antioxidants of the abovementioned type are described by way of example in DE-
A 27 02 661 (US- 4 360 617).
Another group of preferred sterically hindered phenols is provided by those
derived from
substituted benzenecarboxylic acids, in particular from substituted
benzenepropionic acids.
Particularly preferred compounds from this class are compounds of the formula
19
CA 2884863 2019-10-25
fR4
R7
0 0
II 6 II
HO CH2¨CH2¨C-O-R-O-C-CH2¨CH2 OH
R5
R8
where R4, R8, R7, and R8, independently of one another, are Ci-C8-alkyl groups
which
themselves may have substitution (at least one of these being a bulky group),
and R8 is a
divalent aliphatic radical which has from Ito 10 carbon atoms and whose main
chain may
also have C-0 bonds.
Preferred compounds corresponding to this formula are
CH.., CH3 CH3\
/CH3
\c/
CH/ 0 0 C,
3 CH3
HO=
CH2¨CH2¨C-0¨CH2¨CHT.0-CH2¨CH-0-CH2¨CHFO-C-CHT--CH2=
OH
CH3 CH3
(lrganoe 245 from BASF SE)
CH CH CH CH
3\ / 3 3\ / 3
CH/ 0 0CH
3
HO 11 CH2¨CH2¨C-0¨(CH2).6-0-C-CHCH2 411 OH 3
CH3\C
CH3 / \CH3
CH( \CH3
(Irganox 259 from BASF SE)
All of the following should be mentioned as examples of sterically hindered
phenols:
2,2'-methylenebis(4-methyl-6-tert-butylphenol), 1,6-hexanediol bis[3-(3,5-di-
tert-butyl-
4-hydroxyphenyl)propionate], pentaerythrityl tetrakis[3-(3,5-di-tert-butyl-
4-hydroxyphenyl)propionate], distearyl 3,5-di-tert-butyl-4-
hydroxybenzylphosphonate,
2,6,7-trioxa-1-phosphabicyclo[2.2.2]oct-4-ylmethyl 3,5-di-tert-butyl-4-
hydroxyhydrocinnamate, 3,5-di-tert-butyl-4-hydroxypheny1-3,5-
distearylthiotriazylamine,
CA 2884863 2019-10-25
2-(2'-hydroxy-3'-hydroxy-3',5'-di-tert-butylphenyI)-5-chlorobenzotriazole, 2,6-
di-tert-buty1-4-
hydroxymethylphenol, 1,3,5-trimethy1-2,4,6-tris(3,5-di-tert-buty1-4-
hydroxybenzyl)benzene,
4,4'-methylenebis(2,6-di-tert-butylphenol), 3,5-di-tert-butyl-4-
hydroxybenzyldimethylamine.
Compounds which have proven particularly effective and which are therefore
used with
preference are 2,2'-methylenebis(4-methy1-6-tert-butylphenol), 1,6-hexanediol
bis(3,5-di-tert-
buty1-4-hydroxyphenyl)propionate (Irganox 259), pentaerythrityl tetrakis[3-
(3,5-di-tert-buty1-
4-hydroxyphenyl)propionate], and also N,N'-hexamethylenebis-3,5-di-tert-buty1-
4-
hydroxyhydrocinnamide (lrganox 1098), and the product Irganox 245 described
above
from BASF SE, which has particularly good suitability.
The amount comprised of the antioxidants E), which can be used individually or
as a mixture,
is from 0.05 up to 3% by weight, preferably from 0.1 to 1.5% by weight, in
particular from 0.1
to 1% by weight, based on the total weight of the molding compositions A) to
E).
In some instances, sterically hindered phenols having not more than one
sterically hindered
group in ortho-position with respect to the phenolic hydroxy group have proven
particularly
advantageous; in particular when assessing colorfastness on storage in diffuse
light over
prolonged periods.
The molding compositions of the invention can comprise, as component E), from
0.05 to 5%
by weight, preferably from 0.1 to 2% by weight, and in particular from 0.25 to
1.5% by weight,
of a nigrosin.
Nigrosins are generally a group of black or gray phenazine dyes (azine dyes)
related to the
indulines and taking various forms (water-soluble, liposoluble, spirit-
soluble), used in wool
dyeing and wool printing, in black dyeing of silks, and in the coloring of
leather, of shoe
creams, of varnishes, of plastics, of stoving lacquers, of inks, and the like,
and also as
microscopy dyes.
Nigrosins are obtained industrially via heating of nitrobenzene, aniline, and
aniline
hydrochloride with metallic iron and FeCl3 (the name being derived from the
Latin
niger = black).
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CA 2884863 2019-10-25
Component E) can be used in the form of free base or else in the form of salt
(e.g.
hydrochloride).
Further details concerning nigrosins can be found by way of example in the
electronic
encyclopedia Rompp Online, Version 2.8, Thieme-Verlag Stuttgart, 2006, keyword
"Nigrosin".
The molding compositions of the invention can comprise, ad component E), from
0 to 20% by
weight, preferably from 1 to 15% by weight, and in particular from 5 to 15% by
weight, of a
nitrogen-containing flame retardant, preferably a melamine compound.
Suitable compounds (often also termed salts or adducts) are melamine sulfate,
melamine,
melamine borate, melamine oxalate, melamine phosphate prim., melamine
phosphate sec.,
and melamine pyrophosphate sec., melamine neopentyl glycol borate, and
polymeric
melamine phosphate (CAS No. 56386-64-2 and 218768-84-4).
Preference is given to melamine polyphosphate salts derived from a 1,3,5-
triazine compound
of which the number n for the average degree of condensation is from 20 to
200, and 1,3,5-
triazine content, per mole of phosphorus atom, is from 1.1 to 2.0 mol of a
1,3,5-triazine
compound selected from the group consisting of melamine, melam, melem, melon,
ammeline, ammelide, 2-ureidomelamine, acetoguanamine, benzoguanamine, and
diaminophenyltriazine. It is preferable that the n value for salts of this
type is generally from
40 to 150 and that the 1,3,5-triazine compound:mole of phosphorus atom ratio
is from 1.2 to
1.8. The pH of a 10% by weight aqueous slurry of salts, produced as in
EP109503061, is
moreover generally more than 4.5, and preferably at least 5Ø The pH is
usually determined
by adding 25 g of the salt and 225 g of clean water at 25 C to a 300 ml
beaker, stirring the
resultant aqueous slurry for 30 minutes and then measuring the pH. The
abovementioned n
value, the number-average degree of condensation, can be determined by means
of 31P
solid-state NMR. J. R. van Wazer, C. F. Callis, J. Shoolery, and R. Jones, J.
Am. Chem.
Soc., 78, 5715, 1956, disclose that there is a unique type of chemical shift
that reveals the
number of adjacent phosphate groups and permits clear differentiation between
orthophosphates, pyrophosphates, and polyphosphates. EP1095030B1 moreover
describes
a process which can produce the desired polyphosphate salt of a 1,3,5-triazine
compound
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CA 2884863 2019-10-25
which has an n value of from 20 to 200 and has from 1.1 to 2.0 mol 1,3,5-
triazine content of a
1,3,5-triazine compound.
Said process comprises the conversion of a 1,3,5-triazine compound into its
orthophosphate
salt by orthophosphoric acid, with subsequent dehydration and heat treatment,
in order to
convert the orthophosphate salt into a polyphosphate of the 1,3,5-triazine
compound. Said
heat treatment is preferably carried out at a temperature of at least 300 C,
and preferably at
at least 310 C. In addition to orthophosphates of 1,3,5-triazine compounds it
is equally
possible to use other 1,3,5-triazine phosphates, inclusive by way of example
of a mixture of
orthophosphates and pyrophosphates.
Preference is given to aluminum phosphite [Al(H2P03)3], secondary aluminum
phosphite
[Al2(HP03)3], basic aluminum phosphite [Al(OH)(H2P03)2*2aq], aluminum
phosphite
tetrahydrate [Al2(HP03)3*4aq], aluminum phosphonate, A17(HP03)9(OH)6(1,6-
hexanediamine)1.5*12H20, Al2(HP03)3*xA1203*nH20, where x = 2.27 ¨ 1, and/or
A141-16P16018
(see W02012/45414).
A person skilled in the art is aware of other suitable nitrogen-containing
flame retardants.
The thermoplastic molding compositions of the invention can comprise, as
component E),
conventional processing aids, such as stabilizers, oxidation retarders, agents
to counteract
decomposition by heat and decomposition by ultraviolet light, lubricants and
mold-release
agents, colorants, such as dyes and pigments, nucleating agents, plasticizers,
etc.
Examples of oxidation retarders and heat stabilizers are sterically hindered
phenols and/or
phosphites and amines (e.g. TAD), hydroquinones, aromatic secondary amines,
such as
diphenylamines, various substituted members of these groups, and mixtures of
these, in
concentrations of up to 1% by weight, based on the weight of the thermoplastic
molding
compositions.
UV stabilizers that may be mentioned, the amounts of which used are generally
up to 2% by
weight, based on the molding composition, are various substituted resorcinols,
salicylates,
benzotriazoles, and benzophenones.
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CA 2884863 2019-10-25
Materials that can be added as colorants are inorganic pigments, such as
titanium dioxide,
ultramarine blue, iron oxide, and carbon black, and also organic pigments,
such as
phthalocyanines, quinacridones, perylenes, and also dyes, such as
anthraquinones.
Materials that can be used as nucleating agents are sodium phenylphosphinate,
aluminum
oxide, silicon dioxide, and also preferably talc powder.
The thermoplastic molding compositions of the invention can be produced by
processes
known per se, by mixing the starting components in conventional mixing
apparatus, such as
screw-based extruders, Brabender mixers, or Banbury mixers, and then extruding
the same.
The extrudate can be cooled and pelletized. It is also possible to premix
individual
components and then to add the remaining starting materials individually
and/or likewise in
the form of a mixture. The mixing temperatures are generally from 230 to 320
C.
In another preferred mode of operation, components B) and C), and also
optionally D) and
E), can be mixed with a prepolymer, compounded and pelletized. The resultant
pellets are
then solid-phase condensed under inert gas continuously or batchwise at a
temperature
below the melting point of component A) until the desired viscosity is
reached.
The thermoplastic molding compositions of the invention feature good flame
retardancy and
excellent phosphorus stability and UV resistance.
The molding compositions of the invention exhibit markedly reduced reddish
coloring, and
the use of component C) in conjunction with red phosphorus gives the
compounded material,
and the moldings obtainable therefrom, a gray intrinsic color. These are
therefore also
suitable for applications requiring a pale intrinsic color or a pale coloring
(white or gray).
The use, in the invention, of Cu compounds and/or Ag compounds leads to the
production of
molding compositions or moldings which exhibit increased UV resistance and
reduced
phosphine formation.
The use, in the invention, of Cu compounds and/or Ag compounds leads to the
production of
molding compositions or moldings with A L color values at least 15% lower than
those of PA
molding compositions without component C) (in accordance with DIN 53236 and
ISO 7724-3,
24
CA 2884863 2019-10-25
CieLab method), and also to A a color values that are 35% lower and to A b
color values that
are at least 35% lower.
The phosphorus release values (28 days/70 C) are below 200 pg of P/specimen,
preferably
below 160 pg of P/specimen.
These materials are therefore suitable for producing fibers, foils, and
moldings of any type.
Some examples will now be mentioned: plug connectors, plugs, plug parts, cable-
harness
components, circuit mounts, circuit-mount components, three-dimensionally
injection-molded
circuit mounts, electrical connectors, and mechatronic components.
The moldings or semifinished products to be produced in the invention from the
thermoplastic molding compositions can be used by way of example in the motor
vehicle
industry, electrical industry, electronics industry, telecommunications
industry, information-
technology industry, consumer-electronics industry, or computer industry, in
vehicles and
other means of conveyance, in ships, in spacecraft, in the household, in
office equipment, in
sports, in medicine, and also generally in articles and parts of buildings
which require
increased fire protection.
Possible uses of improved-flow polyamides in the kitchen and household sector
are for the
production of components for kitchen devices, e.g. fryers, smoothing irons,
knobs, and also
applications in the garden and leisure sector.
Examples
The following components were used:
Component A/1
Nylon-6,6 with intrinsic viscosity IV 150 ml/g, measured as a 0.5% by weight
solution in 96%
by weight sulfuric acid at 25 C in accordance with ISO 307. (Ultramid A27
from BASF SE
was used.)
Component A/2
PA 66 with IV 125 ml/g (Ultramid A24 from BASF SE)
CA 2884863 2019-10-25
Component B/1
50% strength concentrate of red phosphorus with average particle size (d50)
from 10 to
30 pm in an olefin polymer of: 59.8% by weight of ethylene, 35% by weight of n-
butyl
acrylate, 4.5% by weight of acrylic acid, and 0.7% by weight of maleic
anhydride (component
D) with melt flow index MFI 10 g/10 min (190/2.16). The copolymer was produced
via
copolymerization of the monomers at elevated temperature and elevated
pressure.
Component B/2
Preci (see above) without elastomer D)
Component C/1
Copper iodide
Component C/2
bis(Triphenylphosphine)copper iodide complex CAS No.: 16109-82-3
Component E/1:
Standard chopped glass fiber for polyamides, length = 4.5 mm, diameter = 10
pm.
Component E/2:
N,N'-Hexamethylenebis-3,5-di-tert-butyl-4-hydroxhydrocinnamide (Irganox 1098)
Component E/3:
Ca stearate
Component E/4
ZnO
Production of the molding compositions
In order to provide evidence of the phosphorus stability improvements
described in the
invention, appropriate plastics molding compositions were manufactured via
compounding.
To this end, the individual components were mixed in a ZSK 26 (Berstorff) twin-
screw
extruder with throughput 20 kg/h and a flat temperature profile at about 270
C, extruded in
the form of strand, cooled until pelletizable, and pelletized.
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CA 2884863 2019-10-25
The test specimens for the studies set out in table 1 were injection-molded in
an Arburg
420C injection-molding machine at a melt temperature of about 270 C and mold
temperature
of about 80 C. In the examples of the invention, component C) was applied to
the dried
pellets in the form of powder in a drum.
Testing of plastics parts for phosphorus release:
A specimen of plastic (125 x 12.5 x 1.6 mm) was halved, and each half was
placed in a 10 ml
glass beaker. A silver contact material (10 x 50 x 0.125 mm) was placed in a
short test tube.
The three specimens were then placed in a 100 ml screw-cap bottle, 5 ml of
water were
added, and the sealed system was placed in a drying oven at 70 C. After 28
days, the test
tube was removed and filled to the top with water, and the entire contents
were placed in a
glass beaker. 5 ml of conc. hydrochloric acid were added, and the mixture was
evaporated
almost to dryness. The metal specimen was then removed and rinsed with water;
1 ml of
sulfuric acid was admixed with the residue, and the mixture was again
evaporated almost to
dryness. 20 ml of water are then used for dilution, 4 ml of 5% strength
potassium
peroxodisulfate solution are added, and the mixture is heated for 30 minutes.
The
phosphorus was then determined photometrically by using molybdenum blue, in pg
of
phosphorus/specimen of plastic.
Color measurement:
Color was measured in accordance with DIN 53236:1983, method B. The
calculation method
used was in accordance with DIN 6174:1979, which is identical with ISO 7724-3,
this being
what is known as the CieLab method:
L* = Lightness; + is whiter; - is blacker
a* = Color components; + redder; - greener
b* = Color components; + yellower; - bluer.
The value zero means no color = uncolored = colorless.
C*ab = Chroma (uncolored/colored); h ab = Hue angle (from 0 to 360 ).
Evaluation of all of L*, a*, and b* produces the color difference A E*.
The CTI value was determined in accordance with IEC 60112.
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Table 1 shows the constitutions of the uncolored molding compositions and the
results of the
measurements.
Table 1
Component comp INV1 INV2 INV3 INV4 INV5 INV6
1*
All 60.6 60.4 60.1 59.6 60.4 60.1 59.6
B/1 12 12 12 12 12 12 12
C/1 0.2 0.5 1.0
C/2 0.2 0.5 1.0
E/1 26 26 26 26 26 26 26
E/2 + E/3 (50:50) 0.7* 0.7* 0.7* 0.7* 0.7* 0.7*
0.7*
E/4 0.7 0.7 0.7 0.7 0.7 0.7 0.7
Color measurement/delta L 31.3 26.5 24.0 19.7 20.4 18.0
17.3
Color measurement/delta a 29.1 19.1 14.1 6.7 9.5 2.3
0.54
Color measurement/delta b 22.8 15.1 10.6 4.0 6.3 0.8
0.10
Modulus of elasticity/[MPa] 8090 8050 8041 8073 8080 8101 8204
Tensile stress at breald[MPa] 130 132 134 133 131 133 136
Tensile strain at break/[%] 3.6 3.2 3.1 3.2 3.6 3.6 3.5
CTI/M open open open open open open open
Phosphorus release after 28
days/70 C 480 150 60 54 8 5 2
in pg of phosphorus/specimen
*) for comparison
The data in table 1 show that the compositions of the invention exhibit much
better phosphorus
stability than the prior art (reduced phosphorus release). The compositions of
the invention are
also found to have a "darker" color (delta L value smaller) and to have less
red/yellow coloring
(delta a and delta b values smaller).
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Pale-colored PA molding compositions
Basic formulation for table 2
Component A/2 44.1
[ ) by weight]
B/2 2
E/1 25
E/2 0.35
E/3 0.35
E/4 0.7
E/5 5
E/6 12.5
Component E/5: Titanium dioxide
Component E/6: Melamine polyphosphate
The respective components C) (see table 2) were incorporated in the
abovementioned
formulation, in each case at 1% by weight (PA content being correspondingly
43.1% by
weight).
Mini extrusion
The specimens were incorporated by means of mini extrusion, using a Micro 15
extruder
from DSM. The processing took place at 280 C.
Color measurement: see table 1.
Daylight aging
Exposure to light in accordance with DIN EN ISO 11341 Method 2:0.35W/m2xnm) at
340 nm,
exposure time 24 h; exposure temperature 38 C (+-2 C), exposure humidity 50%
(+/-10%).
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Table 2: color fastness
Delta color measurement after
Color measurement
weathering
_
______________________________________________________________________________
L* a* b* L* a* b* A
E
Basic formulation
72 12 10 3.4 -7.5 -6.4
10.43
(for comparison)
-FAg(I)CI 63 1 3 0.22 0 0.13
0.25
C12 with KI (1:2) 67 2 1 0.58 -0.91 0.31
1.12
+ Cu(1) acetate 64 +1 -1 0.9
-0.23 -0.14 0.94
+ Cu(I)Br 62 -1 -4 0.21 -0.2
-0.1 0.30
+ Cu(I)CI 62 -1 -3 0.25 -0.04
-0.16 0.30
+ Cu(I)I 64 -1 -3 0.31 -0.28
0.35 0.68
+ Cu(I)20 59 -1 -3 0.78 -0.02
-0.16 0.80
+ Cu(I1)0
67 5 4 1.23 -1.71 0.22 --
2.12
(for comparison)
+ Cu(I) oxalate 61 -1 -3 0.62
-0.11 -0.24 0.67
Cu(I)SCN 64 -1 -2.2 0.04 -0.02 -0.02
0.05
Production of the molding compositions for table 3
The thermoplastic material was processed by means of a Leistritz ZSK 25-F41
twin-screw
extruder with throughput 30 kg/h. Extrusion temperature was 300 C. The polymer
strand was
cooled by means of a waterbath and then pelletized and dried. Injection
molding to give the
test specimens used took place at 320 C.
Mechanical properties were measured in accordance with
Tensile modulus of elasticity: DIN EN ISO 527-1/-2
Tensile strain at break: DIN EN ISO 527-1/-2
Tensile stress at break: DIN EN ISO 527-1/-2
Charpy impact resistance: DIN EN ISO 179.
CA 2884863 2019-10-25
Flame retardancy was tested in accordance with UL 94.
Table 3:
Components compl 1 2 3
Al2 36.75 36.5 36.25 35.75
E3/2 1.85 1.85 1.85 1.85
C412 with KI (1:2) 0.25 0.5 1
D 10 10 10 10
Ell 25 25 25 25
E/2 0.35 0.35 0.35 0.35
E/3 0.35 0.35 0.35 0.35
E14 0.7 0.7 0.7 0.7
E15 12.5 12.5 12.5 12.5
E16 12.5 12.5 12.5 12.5
Mechanical properties
Modulus of elasticity/MPa 8353 7539 7373 7205
Tensile stress at break/MPa 91 90 90 84
Tensile strain at breald% 1.8 2.4 2.2 1.9
Charpy without notch at 23 C/kJ/m2 42 43 43 _____ 38
_ _________________________________________________________________________
UL 94 0.8 mm 2d/23 C
Classification V-0 V-0 V-0 V-0
CTI measurement/V not measured 400 400 400
Color measurement
-E L* 77 76 72 70
7 6 3 1
6 6 2 0
_ _________________________________________________________________________
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Color fastness after 24 h of dry
weathering
A L* 79 78 73 70
A a* 3 3 2 -
0.24
A b* 4 4 2 2
A E* 4.7 3.5 1.0 2.5
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