Note: Descriptions are shown in the official language in which they were submitted.
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Case 3-12247/CGM 224/1-3/~_
CANADA
Mixtures of organo-tin compounds
The present invPntion relates to mixtures of organo-tin compounds
and to chlorinated polymers and foamed plastics materials which
contain these mixtures.
Mixtures consisting of an organo-tin mercaptide and an organo-tin
compound selected from the group consisting of organo-t;n, organo-
tin carboxylate, organo-tin alcoholate or organo-tin oxide, are
described as effective thermostabilisers in German Offenlegungs-
schrift 1 926 949. A mixture consisting of an organo-tin thioglycolic
acid ester and an organo~tin compound as described above is speci-
fically disclosed in this publication.
As it is known that organo-tin mercaptides lower the impact strength
of rigid polymers, there is considerable interest in highly effec-
tive sta-~ilisers which can be employed in small amounts.
Organo-tin compounds are also employed as activators for the manu-
facture of foamed articles composed of plastics. These articles
are ordinarily manufactured ~y known methods, for example by in-
jection moulding, by blending the plastics material with a suitable
blowing agent and choosing the processing temperature such that it
is above the decomposition temperature of the blowing agent.
Often, however, the decomposition temperature is too high above
the processing temperature, so that the blowing agent cannot be
uséd alone. For this reason, activators are often employed which
hasten Lhe decomposition of the blowing agent and/or the decompo-
sition temperature.
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It has now been found that a mixture of organo-tin compounds and
of an organo-tin mercaptopropionic acid ester imparts surprisingly
good light and heat stability to chlorinated polymers and, in
addition, is an effective activator for the manufacture of foamed
plastics.
Accordingly, the present invention provides mixtures consisting
of an organo-tin mercaptide of the formula II or III
R4
(R )n-Sn(-S-cH2cHz~cOOR )3-n (II)
X
R -sn-s-cH2cH2-cooR (III) 5
and an organo-tin carboxylate of the formula IV or V
(R ~ Sn(-OOC-R6)2 (IV)
R -COO-Sn---O---Sn-OOC-R (V)
in which formulae R is Cl-Clz alkyl, X is sulfur or oxygen, R lS
the -S-CH2CH2-CooR5 or -X-Sn(R ) (S-CH~CH2-COOR )3 group, in
which R and X are as defined above, R is C8-C14 alkyl, n is 1 or
2, and R is C10-C30 alkyl, the weight ratio of II:IV or III:IV
being in the range from 9:1 to 1:9.
R as Cl-C12 alkyl is e.g. methyl, ethyl, n-propyl, isopropyl,
n-butyl, tert.-butyl n-amyl, iso-amyl, n-hexyl, n-heptyl, n-octyl,
n-dodecyl. Preferably, R is methyl, n-butyl, n-amyl, n-hexyl and
.,
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n-octyl. Most preferably, R is methyl, n-butyl and n-octyl.
R can be the group -S-CH2CH2-CooR5, wherein R5 is C6~C14 alkyl,
e.g. 2-ethylhexyl, decyl, dodecyl, isotridecyl, tetradecyl. R
is preferably 2-ethylhexyl, dodecyl and isotridecyl, especially
2-ethylhexyl and isotridecyl.
4 b th group -X-Sn(Rl) (S-CH2CH2-COOR )3-n~ 5
and n are as defined above. Preferably,R is -S-CH2CH2-COOR ,
R as C10-C30 alkyl is e.g. decyll dodecyl, isotridecyl, tetradecyl,
iso-octadecyl, nonadecyl, docosyl, hexacosyl.
Preferabiy, R6 is C10-C22 alkyl, most preferably 16-methylheptadecyl,
iso-nonyl and n-undecyl.
Examples of compounds of the formula II are:
octyl-tin tris(dodecyl-~-mercaptopropionate)-
dibutyl-tin bis(isotridecyl-~-mercaptopropionate)
dibutyl-tin bis(2-efhylhexyl-~-mercaptopropionate)
bis(dibutyl-tin 2-ethylhexyl-~-mercaptopropionate? oxide.
The preferred compound of the formula II is dibutyl-tin bis(2-
ethylhexyl-~-mercaptopropionate)O
A preferred example oE the compound of che formula III is butyl(2-
dodecyloxycarbonylethylmercapto)-tin sulfide.
Examples of the compounds of the formulae IVresp.V are:
dibutyl-tin dilaurate
bis(dibutyl isodecanoyl-tin) oxide
dibuf:yl-tin di-isooctadecylate.
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The preferred compound of the formula IV is dibutyl-tin di-isoocta-
decylate.
The chlorinated polymers which contain the stabiliser mixture of
the invention can be homopolymers, e.g. polyvinyl chloride, poly-
vinylidene chlor;de etc. Suitable polymers are emulsion, suspension
and mass polyvinyl chloride. The polymers can also be copol~ners
which have been obtained by copolymerising vinyl chloride or
vinylidene chloride with other ethylenically unsaturated monomers.
Ethylenically unsaturated monomers are compounds which contain
polymerisable C C double bonds, and comprise acrylates, e.g. acrylic
acid, ethyl acrylate9 acrylonitrile; vinyl monomers, e.g. styrene,
vinyl acetate; maleic acid derivatives, e.g. maleic aci~, maleates,
maleic anhydride.
The mixtures of this invention can also be employed as activators
for foaming plastics materials. These plastics materials can be
chlorinated polymers, such as those described above; but polyesters,
polylactones? polyamides, polyethers, polycarbonates and, preferably,
polyols, are also suitable~
It is especially preferred to use the mixtures of this invention in
polymers based on polyvinyl chloride, especially in PVC, viz. both
in plasticised PVC and in rigid PVC. Rigid PVC ~hich has been
stabilised with the mixtures of this invention is most suitable for
external use.
Organo-tin carboxylates as light and heat stabilisers Eor halogenated
polymers have been described in the above mentioned German Offen-
legungsschrift 1 92~ 949 in combination with organo-tin mercapto-
rarboxylates These latter are also known from US patent specifi-
cation 3 642 677.
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The organo~tin carboxylates can be obtained by simple rection of the
alkali salts of the acid in question with a water-soluble salt of
tin.
A particularly uncomplicated method of manufacture is to react the
carboxylic acid, mercaptan and tin reactants simultaneously.
The amount of organo-tin compounds in the substrates depends on
economic and technical aspects. ~s a rule, 0.1 to 3 ~ by weight,
based on the polymer, especially 0.3 to 2 % by weight, is added.
The weight ratio of organo~tin compounds of the formulae II:IV
or III:IV in the mixtures of the invention is 9:1 to 1:9, preferably
9:1 to 6:4.
If desired, it is possible to add to the stabilised polymer
mixtures of the invention 0.1 to 5 % by weight, preferably 0.5
to 3 % by weight, of conventional additives, especially anti-
oxidants, light stabilisers or mixtures thereof. Examples of such
additives are:
antioxidants, such as 2,6-dialkylphenols, e.g. 2,4,6-tri-tert.-butyl-
phenol, 2,6-di-tert.-butyl-4-methylphenyl, 2-tert.-butyl-4,6-di-
methylphenol, the ~-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propionie
acid ester of pentaerythritol ~IRGANOX ~ 1010) or the same ester of
stearyl alcohol (IRGANOX ~ 1076), and others such as bisphenol ~ A,
UV-absorbers and light stabilisers such as 2-(Z'-hydroxyphenyl)-
benztriaæoles, 2,4-bis(2'-hydroxyphenyl)-~-s-triazines, 2-hydroxy-
benzophenones, 1,3-bis-(2'-hydroxybenzoyl)~benzenes, esters of un-
substituted or substituted benæoie aeids, aerylates, and also nickel
eompounds, sterically hindered amines, oxalie diamides, or other
additives, e.g. plasticisers, lubricants, emulsifiers9 fillers,
carbon black, asbestos, kaolin, tale, glass fibres, pigments,
fluorescent whitening agents, flame retardants, antistatic agents.
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The mixture of organo-tin compounds of this invention can be blended
with the polymer by known methods in known mixing devices. To this
end, it is possible to add the blowing agent for foamed plastics
material together with the organo-tin activa~or, or to blend the
activator with a plastics material which already contains the blowing
agent. In oLder to obtain as homogeneous mixtures as possiblej it
is advantageous to blend the individual components in powder
form. It is possible, however, to use plastics granulates, in whic~
case a binder can additionally be employed for better adhesion of the
blowing agent and/or the organo-tin activator.
The mixtures of the present invention are surprisingly effective
heat and light stabilisers. Owing to their excellent light protective
action, the stabilised polymer is especially suitable for external
use. In addition, the mixtures of the invention are surprisingly
effective activators for the manufacture of foamed plastics.
The invention is illustrated in more detail by the following Examples,
in which parts and percentages are by weight unless otherwise
stated.
~xam ~ Dibutyl-tin bis(-2-ethylhexyl-~-mercaptopropionate)
-- - . ,
25.0 g (Q.l mole) of dibutyl-tin oæide is reacted with 43.6 g of
2-ethylhexyL thiopropionate at 110C under a water jet vacuum until
the water of reaction has been completely removed.
Sn (found): 17.1 %; n20 = 1.5015.
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Example 2~
(C H ~ Sn(OOC-C H23)-0-Sn{-C4Hg)2(00C 11 23
4 9 ~ ( 2 2 8 17)2 (30 %)
39.6 g ~0.159 mole) of dibutyl-tin oxide are reacted with 31.8 g
(0.159 mole) of lauric acid at 110C while removing the water of
reaction. The resultant fluid reaction product is mixed with 30 g
of dibutyl-tin bis (2-ethylhexyl-~-mercaptopropionate) obtained
in accordance with Example 1.
Sn (found) : 24.5 %, n20 = 1.4928
The weight ratio of II:V is 1:2.3.
Application Tes_
Example 3: Mill ageing test
A dry blend consisting of 100 parts of PVC (Vestolit ~ HIS 6882),
4 parts of TiO2 and 2.5 parts of stabiliser mixture of Example 2
is subjected to a mill ageing test at 200C, and samples are taken
at 3 minute intervals to determine the Yellowness Index.
Yellowness Index (Y.I.)
_
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mins, 3 6 9 12 15 18 21 24 27 30 33 36
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Y.I. 6.7 7.4 8.3 9.0 9.9 11.5 12.5 14.3 16.9 20.7 28.2 37.7
_ _ _
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Example 4: Weathering test
100 parts of PVC are mixed with 0.2 part of Tinuvin ~ 320 and 2.5
parts of the stabiliser mixture in a high-speed mixer.
The mixture is rolled to a sheet for 5 minutes at 180C on a
laboratory roll mill, and from this sheet a 0.5 mm transparent sheet
is pressed at 180C on a daylight-press. This sheet is exposed to
an accelerated weathering test (Xenotest ~ 150 lamp~ Original
Hanau Quarzlampen GmbH, Hanau, West Germany). The weathering cycle
comprises 29 minutes exposure to xenon-arc radiation and 1 minute
exposure to artificial rain. Exposure is effected in rotation.
In the table below, h indicates the total weathering time in hours.
The test values indicate the course of yellowing (Yellowness
Indices)O
The weathering test as described above is carried out using a dry
blend consisting of 100 parts of PVC (Vestolit~ HIS 6882), 4 parts
of titanium dioxide and 2.5 parts of the stabiliser mixture of Example
2. The results are reported in the following tableO
Time ~ O ~ 2400 ~ 4800 ~ 7200 ~ 9600 ~ 12000
Y~Ii 8.2 5.2 4.8 4.1 4.4 5.7
.._ _ _ . ._
Even after 12000 weathering, the sheet exhibits no discolouration.
