Note: Descriptions are shown in the official language in which they were submitted.
Case 3-13414/CGM 262/~
.. ..
Chlorinated thermoplastics stabilised with aminouracils
The presen~ invention relates to chlorinated
thermoplastics wlich are stabilised with aminouracils,
and to the use of specific aminouracils for stabilising
such subs~rates.
The use of aminouracils as stabilisers for PVC,
in particular of 1,3-dimethyl-6-aminouracil and
1,3-dimethyl-6-anilinouracil, is known from German
Auslegeschrift 1 694 873. It has been found, however;
that these known stabilisers for PVC do not always satisfy
the exacting demands of actual practicc. Their
effectiveness, i.e. their compatibility with the substrate~
is insufficient. For example, 1,3-dimethyl-6-aminouracil
gives rise to pronounced haze in moulding compounds
stabilised therewith. It is the object of the present
invention to provide stabilisers which do not have these
shortcomings.
Accordingly~ the present invention provides thermo-
plastic moulding compositions based on vinyl chloride
polymers, which compositions contain 0.1 to 5 % by weight
of an aminouracil of the formula I
o .
7~
-- 2 ~
wherein Rl is hydrogen and R and R3 are C2-C4alkyl.
The most preferred aminouracils are 1,3-diethyl-
6-aminouracil or L,3-di-n-butyL-6 aminouracil.
The uracils employed in the practice of this
invention are known and may be obtained by known methods,
eOg. as described in US patent specification 2 598 936.
Those compounds which are novel can be prepared by methods
analogous to known ones, e.g. as described in the US patent
specification just referred to.
The uracils employed in the practice of this
invention are most suitable for protecting chlorinated
thermoplastics against hea~-induced degradation. They may
be incorporated in the thermoplastics to be stabilised
singly or in admixture with one another, before processing
in conventional apparatus, and in respective amounts of
0.1 to 5 % by weight, preferably of 0.2 to 1D5 % bY weight,
based on the entire composition~
A still better stabilising action is obtained by
additionally using customary amounts of one of ~he
conventional PVC stabilisers and/or additives such as
epoxy compounds~ preferably epoxidised fatty acid esters
such as epoxidised soybean oil, phosphites, organometal
compounds of metals of the second main and auxiliary group
of the Periodic Table, e.g. metal carboxylates or metal
~' ~
~ .
7~
-- 3 --
phenolates, in particular metal salts of carboxylic acids
contalning 8 to 20 carbon atoms or of phenols containing 6
to 20 carbon atoms, e.g calcium stearate or zinc stearate,
or also inorganic salts of metals of the second auxiliary
group of the Periodic Table, e.g. ~nC12, as well as organotin
compounds, in particular mixtures of mono- and diorganotin
compounds, such as mono-n-octyl tris-isooctyl thioglycolate
and di-n-octyl bis-isooctyl thioglycolate, or organoantimony
compounds SUCIl as antimony tris-isooctyl thioglycolate
(isooctyl = L,1~3,3-tetramethylbutyl).
Co-stabilisers are preferably incorporated in
amounts of 0.05 to 6 % by weight, preferably 0.1 to 3 % by
weight, based on the entire composition. The ratio of
aminouracil to co-stabiliser may be from 2:1 to 1:8.
Particularly suitable conventional phosphites are
those of the general formulae II, III or IV
R O--~OR ( I I )
OR
8 ~ 5 ( I I I )
R5~P/ 2\C/ 2 ~OR5 (IV)
OCH2 CH20
wherein each of R5, R6 and R7 independently of one another
is Cl-C18alkyl, Cl-C20alkenyl, C6-C12aryl, C7-cl9alkar
which is unsubstituted or substituted by hydroxy or
cl-C4alkoxy, or is C5 C7cycloalkyl, and R~ is C2-C6alkylene
7~
-- 4 --
which is unsubstituted or substituted by Cl-C18alkyl,
C2-C13alkoxymethyl or C2~C13alkylthiomethyl or by phenyl,
or is C6-ClOarylene which is unsubstltuted or substituted by
Cl-C4alkyl, or is C5-C7cycloalkylene.
6 7
~ , R and R as Cl-C18alkyl are e.g. methyl, ethyl,
n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl,
n-pentyl,n-hexyl, n-octyl, n-nonyl, decyl, dodecyl,
tetradecyl~ hexadecyl or octadecyl. Alkyl groups containing
8 to 18 carbon atoms Qre preferred,
R5, ~6 and R7 as Cl-C20alkenyl are e.g. allyl~
but-2.-enyl~ pentenyl, hexenyl~ heptenyl or oleyl.
S 6
R , R and R7 as aryl may be e.g. naphthylg
biphenyl or, preferably, phenyl.
6 7
R , R and R as C7~Clgalkaryl which is unsubstituted
or substituted by hydroxy or Cl-C~alkoxy are e g~ tolyl,
ethylphenyl~ xylyl, cumyl, cymyl, cresyl, 4-methoxyphenyl~
2,4-dimethoxyphenyL, alkoxyphenyl or butoxyphenyL
R , ~ and R7 as C5-C7cycloalkyl are e.g. cyclopentyl,
cycloheptyl and, in particular, cyclohexyl.
As C2-C6alkylene which is unsubstituted or substitut-
ed by Cl-C18alkyl or phenyl, R may be e.g. ethylene, propyl-
ene or hexamethylene, substituted by methyl, ethyl, propyl
isopropyl, butyl, hexyl, decyl, dodecyl, tetradecyl,
octadecyi or phenyl, and is, in particular, 2-propyl 2-
methylpropylenP, l-propyl 2-ethylpropylene, phenylethylene,
or also unsubstituted ethylene.
,~ ,.~
-- 5
As C2-C6alkylene substituted by C2-C13alkoxymethyl or
C2-cl3a~ylthiome~y~ R may be e.g. ethoxymethylethylene,
butoxyme~hylethylene~ octyloxymethyletllylene or dodecylthio-
methylethylene.
As C6-ClOarylene which is unsul)stituted or substitut-
ed by Cl-C4alkyl~ R is e.g. tert-butylphenylene or
unsubstituted phenylene.
As C5-C7cycloalkylene, R8 is in particular
cyclohexylene~
Preferred phospllites of the formula IV are those in
which R5 is Cl-C18alkyl and, in particular, C8-C18alkyl, and
is most preferably octyl or decyl,
Very suitable phosphites are trioctyl, tridecyl,
tridodecyl, tritetradecyl, tristearyl, trioleyl,
triphenyl, tricresyl, tris-p-nonylphenyl or tricyclohexyl
phosphite. Especially preferred phosphites are a-ryl-dialkyl
phosphites and alkyl-diaryl phosphites, e.g, phenyldidecyl
phosphite, nonylphenyldidecyl phosphite, (2,4-di-tert-
butylphenyl)-didodecyl phosphite and (2,6-di-tert-
butylphenyl)-didodecyl phosphite.
A particularly good stabilising action is obtained
by adding to t~e aminouracils of the formula I at least one
epoxy compound and/or metal carboxylate or metal phenolate
of a metal of the second main group of the Pe.iodic Table,
preferably a calcium carboxylate, most preferably calcium
stearate. A still better stabilising action is obtained by
using additionally at least one æinc or cadmium carboxylate,
organotin compound or organoantimony compound. Preferred
organotin compounds are mixtures of mono- and diorganotin
compounds.
7~
-- 6
The best stabilising action, however~ is obtained
by stabilising the chLorinated theremoplastics with a
mixture of at least one aminouracil of the formula I, a~
least one epoxy compound and/or metal carboxylate or metal
phenolate of a metal oE the second main group of the Periodic
Table, at least one zinc or cadmium carboxylate or
organotin compound, and at least one of the phosphites
defined above.
Surp~-isingl~, even a relativel~ small concentration
of an aminoura~il of the formula I ensures an excellent
stabilising action under these conditions.
It is preferred to use vinyl chloride polymers or
copolymers for the moulding co;npositions of the invention.
Suspension and mass polymers, and emulsion polymers having
a low content of emulsifier, are preferred. Examples of
suitable comonomers for the copolymers are: vinyl acetate,
vinylidene chLoride, trans-dichloroethane~ ethylene,
propylene, butylene, maleic acid, acrylic acid, fumeric acid
or itaconic acid. Further suitable chlorlnated polymers are
post-chlorinated PVC and chlorinated olefins, as well as
graft polymers of PVC with EVA and MBS~
The thermoplastics stabi]ised according to the
invention are obtained by incorporating the stabilisers
and, if desired, further stabilisers, in the p~lymer. A
homogeneous mixture of stabiliser and polyvinyl chloride
can be obtained e.g. using a two-roll mixer ln the
temperature range from 150 to 210 C. Depending on the end
use of the moulding compound~ further additives may also
be incorporated before or simultaneously with the
incorporation of the stabiliser. Exampl~es of further
additives are: lubrlcants (preferably montan waxes or
glycerol esters), fatty acid esters, paraffins, plasticisers,
~,
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fillers, carbon black, asbestos, kaolin, talcumg glass
fi~res~ modifiers (suc~ as impact strength additives) 3
fluorescent whitening agents, pigments, light stabillsers,
W absorbers, flame retardan~s, antistats or further
co-sta~ilisers, e g. antioxidants, in particular phenolic
ant;oxidants, The thermoplastic moulding compositions
obtained according to the invention can be processed
to moulded articles by conventional moulding methods, e~g.
by extrusion, injection moulding or calendering. The use of
the moulding compositions as plastisols is also possible.
The stabilisers employed in the practice of this invention
effect excellent stabilisation of the thermoplastic moulding
compositions obtained. The light stability is also good.
The invention is illustrated in more detail by the
following Examples, in which parts are by weight, unless
otherwise stated~
-- 8 --
Exa~ A dry blend comprising each of the ~ormul.at.ions
lîsted bel.ow in 1) - le) is rolled for 5 minutes at 180C
on a mixer roll~ Test samples having a thickness o~
0.3 mm are then ta'~en from the rolled sheet obtained. These
samples are subjected to heat in an oven at 180C, and at
10 minute intervals the thermal ageing of a sanple is
determined according to the Yellowness Index of ASTM D 1925-70.
The results are reported in the ~ollowing tables.
1) S-PVC (K-value 64)100 parts
epoxidised soybean oil2 parts
Static heat test (180C)
Therm~ ageing (min) o lo 1 20
Yellowness Index 28,080,0 7100
la) S-PVC (K-value 64) 100 parts
epoxidised soybean oil 2 parts
1,3 diethyl-6-aminouracil 0.6 part
Static heat test (180C)
¦Thermal ageing (min) ¦ ¦ lo ~ 20 ¦ 30 ¦ 40 ¦ 50 ¦
_ _
Yellowness Index 3,8 6~7 9,5 17,9 29 52.9
~'"''~``
7~
g
lb) S-PVC (K-value 64) 100 parts
epoxidised soybean oil 2 parts
lg3-di-n butyl~6-aminouracil 0.6 part
Static heat test (180C)
Thermal ageing (min) o ¦ lo 20 30 40
_ _. ~ _
Yellowness Index 2~5 ~ 6~3 14J7 24,6 52, ,
_ _ .
lc) S-PVC (K-value 64) 100 parts
epoxidised soybean oil 3 parts
zinc stearate 0~15 part
calcium stearate 0,35 part
tridecyl phosphite 0.55 part
Static heat test (180 C)
_ _ I __
Thermal ageing (min) o lo ¦ 20 ` 30 40
_ _ ,
Yellowness Index 25~ 2 33.7 33,7 69,8 ~loo
ïd) S-PVC (K-value 64) loo parts
epoxidised soybean oil 3 parts
1,3-di-ethyl-6-aminouracil 0.46 part
zinc stearate 0.15 part
calcium stearate 0.35 part
tridecyl phosphite 0.55 part
Static heat test (180C)
76
-- 10 ~
. _ _I~
IThermal ageing (min) o lo 20 30 40
_ _
Yellowness Index ¦ 2,3 6,0 9,5 14,7 29,4
le) S-PVC (K-value 64) 100 parts
epoxi.dised soybean oil 3 parts
1,3-di-n-butyl-6-aminouracil 0.6 part
zinc stearate 0.15 part
calcium stearate 0~35 part
tridecyl phosphite 0.55 part
Static heat test (180C)
___
Tho~ ~1 ,~eir~ Inin) o lo 20 30 ¦ 40
_ . I ._
¦Y~llowness Index 2,4 407 7t6 14,9 J 44,0
Exam~ 2: A dry blend consisting of 100 parts of S-PVC
(K-value 64), 2 parts of epoxidised soybean oil and 0.6 part
of one of the aminouracils listed in the following table, is
rolled for 5 minutes at loOC on a mixer roll. The rolled
sheet obta.ined is processed at 180C or 1 minute to 1 mm
sheetS (panels) which are visually assessed for haze. The
results are reported in the following table.
1,3-diethyl-6-aminouracil no haze
_ . .
1,3-di-n-butyl-6-aminouracil no haze
7~
Examele 3: A dry blend consisting of 100 parts of
S-PVC ~-value 64), 2 parts of epoxidised soybean oil and
0.46 part of 1,3-diethyl-6-aminouracil is rolled for 5
minutes at 180C pn a mixer roll. The rolled sheet so
ob~ained is processed a~ 180C for 1 minute to 1 mm sheets
(panels). The degree of yellowing determined in accordance
with the Yellownes Index of ASTM D 1925-70 is 16.5.
Example 4: A dry blend consisting of 100 parts of
S-PVC ~-value 64), 2 parts of epoxidised soybean oil and
0.6 part of 1,3-di-n-butyl-6-aminouracil is processed to
1 mm sheets (panels) as described in Example 3. The degree of
yellowing determined in accordance with the Yellowness
Index of ASTM D 1925-70 is 15.9.
Example 5: A dry blend consisting of 100 parts of
S-PVC ~-value 64), 3 parts of epoxidised soybean oil,
0.46 part of 1,3-diethyl-6-aminouracil, 0.15 part of
zinc stearate, 0.35 parts of calcium stearate and 0.55
part of tridecyl phosphite, is processed to 1 mm sheets
~panels) as described in ~xample 3. The degree of yellowing
determined in accordance with the Yellowness Index of
ASTM D 1925-70 is 13.9.
Exam~e 6: A dry blend consisting of 100 parts of
S-PVC (K-value 64), 3 parts of epoxidised soybean oil,
0 6 part of 1~3~di-n-butyl-6-aminouracil, 0.15 part of
zinc stearate, 0.35 parts of calcium stearate and 0.55
part of tridecyl phosphite, is processed ~o 1 mm sheets
;~
,~,
'7~i
- 12 -
(panels) as described in Example 3. The degree of yellowing
determined in accordance with the Yellowness Inclex of
ASTM D 1925-70 is 14.1.
A sheet having a degree of yellowing of 64.9
(determined in accordance with the Yellowness Index of
ASTM D 1925-70) is obtained with a dry blend as described
in Examples 5 and 6, but without the addition of aminouracil.
!: ; ',
