U.S. patent application number 15/524683 was filed with the patent office on 2017-11-02 for novel silicone composition crosslinking catalysts.
This patent application is currently assigned to Bluestar Silicones France SAS. The applicant listed for this patent is Bluestar Silicones France SAS, Centre National de la Recherche Scientifique - CNRS, Universite Claude Bernard Lyon I. Invention is credited to Magali BOUSQUIE, Delphine CROZET, Sebastien MARROT, Vincent MONTEIL, Jean RAYNAUD.
Application Number | 20170313823 15/524683 |
Document ID | / |
Family ID | 52627322 |
Filed Date | 2017-11-02 |
United States Patent
Application |
20170313823 |
Kind Code |
A1 |
MONTEIL; Vincent ; et
al. |
November 2, 2017 |
NOVEL SILICONE COMPOSITION CROSSLINKING CATALYSTS
Abstract
A crosslinked silicone material Y obtained by heating to a
temperature of between 70 and 200.degree. C., a crosslinkable
composition X including an organopolysiloxane compound A
containing, per molecule, at least two C.sub.2-C.sub.6 alkenyl
radicals bonded to silicon atoms; an organohydrogenopolysiloxane
compound B containing, per molecule, at least two hydrogen atoms
bonded to an identical or different silicon atom; a catalyst C of
formula [Ni(L.sup.1).sub.2] where Ni represents nickel at degree of
oxidation II; L.sup.1 which may be identical or different,
represents a .beta.-dicarbonylato anion or the enolate anion of a
.beta.-dicarbonylated compound; optionally an adhesion promoter D;
and optionally a charge E.
Inventors: |
MONTEIL; Vincent; (Lyon,
FR) ; RAYNAUD; Jean; (Villeurbanne, FR) ;
CROZET; Delphine; (Villeurbanne, FR) ; BOUSQUIE;
Magali; (Lyon, FR) ; MARROT; Sebastien; (Lyon,
FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bluestar Silicones France SAS
Universite Claude Bernard Lyon I
Centre National de la Recherche Scientifique - CNRS |
Lyon
Villeurbanne
Paris |
|
FR
FR
FR |
|
|
Assignee: |
Bluestar Silicones France
SAS
Lyon
FR
Universite Claude Bernard Lyon I
Villeurbanne
FR
Centre National de la Recherche Scientifique - CNRS
Paris
FR
|
Family ID: |
52627322 |
Appl. No.: |
15/524683 |
Filed: |
November 6, 2015 |
PCT Filed: |
November 6, 2015 |
PCT NO: |
PCT/FR2015/053012 |
371 Date: |
May 5, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08K 5/0091 20130101;
C08G 77/44 20130101; C08J 2483/05 20130101; C08K 3/22 20130101;
C08L 2205/025 20130101; C08G 77/12 20130101; C08L 83/04 20130101;
C08J 2483/07 20130101; C08J 2383/07 20130101; C08G 77/20 20130101;
C08J 3/24 20130101; C08L 83/00 20130101; C08G 77/08 20130101; C08J
2383/05 20130101; C08G 77/70 20130101; C08G 77/32 20130101; C08L
83/04 20130101; C08L 83/00 20130101; C08K 5/0091 20130101 |
International
Class: |
C08G 77/44 20060101
C08G077/44 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 7, 2014 |
FR |
14 60803 |
Claims
1. Crosslinked silicone material Y obtained by heating to a
temperature of between 70 and 200.degree. C., preferably between 80
and 150.degree. C., and more preferably between 80 and 130.degree.
C., a crosslinkable composition X comprising: at least one
organopolysiloxane compound A comprising, per molecule, at least
two C.sub.2-C.sub.6 alkenyl radicals bonded to silicon atoms, at
least one organohydrogenopolysiloxane compound B comprising, per
molecule, at least two hydrogen atoms bonded to an identical or
different silicon atom, at least one catalyst C which is a complex
corresponding to the following formula: [Ni(L.sup.1).sub.2] in
which: the symbol Ni represents nickel at degree of oxidation II,
the symbols L.sup.1, which may be identical or different, represent
a ligand which is a .beta.-dicarbonylato anion or the enolate anion
of a .beta.-dicarbonylated compound, optionally at least one
adhesion promoter D and optionally at least one charge E.
2. Crosslinked silicone material Y according to claim 1, wherein
the catalyst C is present in a content ranging from 0.001 to 10%
molar of nickel per number of moles of C.sub.2-C.sub.6 alkenyl
radicals bonded to silicon atoms of the organopolysiloxane compound
A, preferably between 0.01 to 7%, and more preferably between 0.1
to 5%.
3. Crosslinked silicone material Y according to claim 1, wherein
the composition X is free of catalyst based on platinum, palladium,
ruthenium or rhodium.
4. Crosslinked silicone material Y according to claim 1, wherein
the ligand L.sup.1 is an anion derived from a compound of formula
(1): R.sup.1COCHR.sup.2COR.sup.3 (1) in which: R.sup.1 and R.sup.3,
which may be identical or different, represent a C.sub.1-C.sub.30
linear, cyclic or branched hydrocarbon radical, an aryl containing
between 6 and 12 carbon atoms, or a --OR.sup.4 radical with R.sup.4
which represents a C.sub.1-C.sub.30 linear, cyclic or branched
hydrocarbon radical, R.sup.2 is a hydrogen atom or a hydrocarbon
radical, preferably alkyl, comprising from 1 to 4 carbon atoms;
with R.sup.1 and R.sup.2 can be connected in order to form a
C.sub.5-C.sub.6 cycle, and R.sup.2 and R.sup.4 can be connected in
order to form a C.sub.5-C.sub.6 cycle.
5. Crosslinked silicone material Y according to claim 4, wherein
the compound of formula (1) is chosen from the group comprising
.beta.-diketones: 2,4-pentanedione (acac); hexanedione-2,4;
heptanedione-2,4; heptanedione-3,5; ethyl-3 pentanedione-2,4;
methyl-5 hexanedione-2,4; octanedione-2,4; octanedione-3,5;
dimethyl-5,5 hexanedione-2,4; methyl-6 heptanedione-2,4;
dimethyl-2,2 nonanedione-3,5; dimethyl-2,6 heptanedione-3,5;
2-acetylcyclohexanone (Cy-acac);
2,2,6,6-tetramethyl-3,5-heptanedione (TMHD);
1,1,1,5,5,5-hexafluoro-2,4-pentanedione (F-acac)]; benzoylacetone;
dibenzoyl-methane; 3-methyl-2,4-pentadione; 3-acetyl-pentane-2-one;
3-acetyl-2-hexanone; 3-acetyl-2-heptanone;
3-acetyl-5-methyl-2-hexanone; benzoylstearoylmethane;
benzoylpalmitoylmethane; octanoylbenzoylmethane;
4-t-butyl-4'-methoxy-dibenzoylmethane;
4,4'-dimethoxy-dibenzoylmethane and
4,4'-di-tert-butyl-dibenzoylmethane, and preferably from
?-diketones 2,4-pentanedione (acac) and
2,2,6,6-tetramethyl-3,5-heptanedione (TMHD).
6. Crosslinked silicone material Y according to claim 1, wherein
the catalyst C is chosen from the complexes [Ni(acac).sub.2],
[Ni(TMHD).sub.2], [Ni(ketoester).sub.2] and [Ni(Rhodiastab
50).sub.2], where "acac" means the anion derived from the compound
2,4-pentanedione, "THMD" means the anion derived from the compound
2,2,6,6-tetramethyl-3,5-heptanedione, "ketoester" means the anion
derived from a methyl ester of acetoacetic acid and "Rhodiastab 50"
means a mixture of anions derived from the compound
benzoylstearoylmethane, and of anions derived from the compound
benzoylpalmitoylmethane.
7. Crosslinked silicone material Y according to claim 6, wherein
the organopolysiloxane A comprises: (i) at least two siloxyl units
(A.1), which may be identical or different, of the following
formula: W a Z b SiO d - ( a + b ) 2 ( A .1 ) ##EQU00007## in
which: a=1 or 2, b=0, 1 or 2 and a+b=1, 2 or 3; the symbols W,
which may be identical or different, represent a C.sub.2-C.sub.6
linear or branched alkenyl group, and the symbols Z', which may be
identical or different, represent a monovalent hydrocarbon group
having from 1 to 30 carbon atoms, and preferably chosen from the
group consisting of alkyl groups having from 1 to 8 carbon atoms
and aryl groups containing between 6 and 12 carbon atoms, and more
preferably chosen from the group consisting of a methyl, ethyl,
propyl, 3,3,3-trifluoropropyl, xylyl, tolyl and phenyl radical,
(ii) and optionally at least one siloxyl unit of the following
formula: Z a 1 SiO 4 - a 2 ( A .2 ) ##EQU00008## in which: a=0, 1,
2 or 3, the symbols Z.sup.2, which may be identical or different,
represent a monovalent hydrocarbon group having from 1 to 30 carbon
atoms and preferably chosen from the group consisting of alkyl
groups having from 1 to 8 carbon atoms inclusive and aryl groups
containing between 6 and 12 carbon atoms, and more preferably
chosen from the group consisting of a methyl, ethyl, propyl,
3,3,3-trifluoropropyl, xylyl, tolyl and phenyl radical.
8. Crosslinked silicone material Y according to claim 1, wherein
the organohydrogenopolysiloxane compound B comprises at least three
hydrogen atoms per molecule directly bonded to an identical or
different silicon atom.
9. Crosslinked silicone material Y according to claim 1, wherein
the organohydrogenopolysiloxane compound B is an organopolysiloxane
comprising: (i) at least two siloxyl units and, preferably, at
least three siloxyl units of the following formula: H d Z c 3 SiO 4
( d + e ) 2 ( B .1 ) ##EQU00009## in which: d=1 or 2, e=0, 1 or 2
and d+e=1, 2 or 3, the symbols Z.sup.3, which may be identical or
different, represent a monovalent hydrocarbon group having from 1
to 30 carbon atoms and preferably chosen from the group consisting
of alkyl groups having from 1 to 8 carbon atoms and aryl groups
containing between 6 and 12 carbon atoms, and more preferably
chosen from the group consisting of a methyl, ethyl, propyl,
3,3,3-trifluoropropyl, xylyl, tolyl and phenyl radical, and (ii)
optionally at least one siloxyl unit of the following formula: Z c
2 SiO 4 - c 2 ( B .2 ) ##EQU00010## in which: c=0, 1, 2 or 3, the
symbols Z.sup.2, which may be identical or different, represent a
monovalent hydrocarbon group having from 1 to 30 carbon atoms and
preferably chosen from the group consisting of alkyl groups having
from 1 to 8 carbon atoms and aryl groups containing between 6 and
12 carbon atoms, and more preferably chosen from the group
consisting of a methyl, ethyl, propyl, 3,3,3-trifluoropropyl,
xylyl, tolyl and phenyl radical.
10. Crosslinked silicone material Y according to claim 1, wherein
the composition X comprises a second organopolysiloxane compound
comprising, per molecule, at least two C.sub.2-C.sub.6 alkenyl
radicals bonded to silicon atoms, different from the
organopolysiloxane compound A, said second organopolysiloxane
compound being preferably divinyltetramethylsiloxane.
11. Crosslinked silicone material Y according to claim 1, wherein
the proportions of the organopolysiloxane A and of the
organohydrogenopolysiloxane B are such that the molar ratio of the
hydrogen atoms bonded to the silicon in the
organohydrogenopolysiloxane B to the alkenyl radicals bonded to the
silicon in the organopolysiloxane A is between 0.2 and 20,
preferably between 0.5 and 15, more preferably between 0.5 and 10
and even more preferably between 0.5 and 5.
12. Crosslinked silicone material Y according to claim 1, wherein,
the composition X comprises one or several functional additives
chosen from: silicone resins, adherence modulators, additives for
increasing consistency, pigments, and heat-resistant, oil-resistant
or fire-resistant additives, for example metal oxides.
13. Use of the catalyst C such as described according to claim 1 as
silicone composition crosslinking catalyst.
14. Crosslinkable composition X comprising: at least one
organopolysiloxane compound A comprising, per molecule, at least
two C.sub.2-C.sub.6 alkenyl radicals bonded to silicon atoms, at
least one organohydrogenopolysiloxane compound B comprising, per
molecule, at least two hydrogen atoms bonded to an identical or
different silicon atom, at least one catalyst C which is a complex
corresponding to the following formula: [Ni(L.sup.1).sub.2] in
which: the symbol Ni represents nickel at degree of oxidation II;
the symbols L.sup.1, which may be identical or different, represent
a ligand which is a .beta.-dicarbonylato anion or the enolate anion
of a .beta.-dicarbonylated compound, optionally at least one
adhesion promoter D and optionally at least one charge E.
15. Method for crosslinking silicone compositions, comprising
heating a composition X according to claim 14 to a temperature of
between 70 and 200.degree. C., preferably between 80 and
150.degree. C., and more preferably between 80 and 130.degree. C.
Description
FIELD OF THE INVENTION
[0001] This invention relates to the field of materials obtained by
crosslinking of silicone compositions in which are put into contact
reagents having at least two unsaturated bonds and organosilicon
compounds having at least two hydrogenosilyated units (ESiH) in the
presence of a catalyst C which is a complex corresponding to the
following formula:
[Ni(L.sup.1).sub.2]
[0002] in which the symbol Ni represents nickel at degree of
oxidation II, and the symbols L', which may be identical or
different, represent a ligand which is a .beta.-dicarbonylato anion
or the enolate anion of a .beta.-dicarbonylated compound.
TECHNOLOGICAL BACKGROUND
[0003] In the field of silicone composition crosslinking,
hydrosilylation, also referred to as polyaddition, is a
preponderant reaction.
[0004] During a hydrosilylation reaction, a compound comprising at
least one unsaturation reacts with a compound comprising at least
one hydrogen atom bonded to a silicon atom. This reaction can for
example be described by the reaction equation (1) in the case of an
unsaturation of the alkene type:
##STR00001##
[0005] or by the reaction equation (2) in the case of an
unsaturation of the alkyne type:
##STR00002##
[0006] The hydrosilylation of unsaturated compounds is carried out
by catalysis, using an organometallic catalyst. Currently, the
suitable organometallic catalyst for this reaction is a platinum
catalyst. As such, most industrial hydrosilylation reactions are
catalysed by the Karstedt platinum complex, of general formula
Pt.sub.2(divinyltetramethyldisiloxane).sub.3 (or in abbreviated
form Pt.sub.2(DVTMS).sub.3):
##STR00003##
[0007] At the beginning of the 2000's, the preparation of
platinum-carbene complexes of general formula:
##STR00004##
[0008] made it possible to have access to more stable catalysts
(see for example international patent application WO 01/42258).
[0009] However, the use of organometallic platinum catalysts is
still problematic. This is a toxic metal, expensive, and is
becoming scarce and of which the cost fluctuates enormously. Its
use on an industrial scale is therefore difficult. It is therefore
sought to reduce as much as possible the quantity of catalyst
required for the reaction, without however reducing the yield and
the speed of the reaction. Moreover, it is sought to have a
catalyst that is stable during the reaction. It has been observed
that, during the catalysed reaction, the metal platinum could
precipitate, which has the consequence of forming insoluble
colloids in the reaction medium. The catalyst is then less active.
In addition, these colloids form a cloud in the reaction medium,
and the products obtained are not satisfactory from an aesthetic
standpoint as they are coloured.
[0010] Finally, platinum based complexes catalyse the
hydrosilylation reactions at ambient temperature with a rapid
kinetics, of about a few minutes. In order to have the time to
prepare, transport and implement the composition before it hardens,
it is often necessary to temporarily inhibit the hydrosilylation
reaction. For example, when it is sought to coat a paper or polymer
substrate with a non-stick silicone coating, the silicone
composition is formulated to form a bath that must remain liquid at
ambient temperature for several hours before being deposited on the
substrate. It is only after this depositing that it is desired for
the hardening by hydrosilylation to occur. The introduction of
hydrosilylation inhibiting additives makes it possible to
effectively prevent the reaction as long as necessary before
activation. However, it is sometimes necessary to use large
quantities of inhibiting agent, which causes a strong inhibition of
the hydrosilylation catalyst. This results in that the speed of
hardening of the composition, even after activation, is slowed
down, which is a major disadvantage from an industrial standpoint
as this in particular requires reducing the coating speed and
therefore the speed of production.
[0011] It would therefore be interesting to propose organometallic
catalysts as an alternative to platinum based catalysts and to have
new silicone materials that are crosslinked and/or hardened by
means of catalysts that no longer have the problems described
hereinabove, in particular that do not require the use of an
inhibiting agent.
[0012] This objective is achieved using a catalyst which is a
complex of nickel (II) that has a specific structure. These
catalysts, in particular, do not require manipulation under
protected atmosphere (for example under argon). The crosslinking
reactions wherein they are implemented can also be carried out in
air, without protected atmosphere.
[0013] This invention thus has for object, according to a first
aspect, a crosslinked silicone material Y obtained by heating to a
temperature of between 70 and 200.degree. C., preferably between 80
and 150.degree. C., and more preferably between 80 and 130.degree.
C., a crosslinkable composition X comprising: [0014] at least one
organopolysiloxane compound A comprising, per molecule, at least
two C.sub.2-C.sub.6 alkenyl radicals bonded to silicon atoms,
[0015] at least one organohydrogenopolysiloxane compound B
comprising, per molecule, at least two hydrogen atoms bonded to an
identical or different silicon atom, [0016] at least one catalyst C
which is a complex corresponding to the following formula:
[0016] [Ni(L.sup.1).sub.2]
[0017] in which: [0018] the symbol Ni represents nickel at degree
of oxidation II, [0019] the symbols L.sup.1, which may be identical
or different, represent a ligand which is a .beta.-dicarbonylato
anion or the enolate anion of a .beta.-dicarbonylated compound,
[0020] optionally at least one adhesion promoter D and [0021]
optionally at least one charge E.
[0022] The term "crosslinked silicone material" means any silicone
based product obtained by crosslinking and/or hardening
compositions comprising organopolysiloxanes having at least two
unsaturated bonds and organopolysiloxanes having at least two
hydrogenosilylated units (.ident.SiH). The crosslinked silicone
material can for example be an elastomer, a gel or a foam.
[0023] The invention also has for object, according to a second
aspect, a crosslinkable composition X such as described
hereinabove.
[0024] The composition X according to the invention is
crosslinkable, i.e., in terms of this application, once the
compounds A and B have reacted together in the presence of the
catalyst C, a three-dimensional network is formed, which leads to
the hardening of the composition. The crosslinking therefore
implies a progressive physical change of the medium constituting
the composition.
[0025] The publications Bogdan Marciniec et al. "Catalyst of
hydrosililation Part XXV. Effect of nickel (o) and nickel (II)
complex catalysts on dehydrogenative silylation, hydrosilylation
and dimerization of vinyltriethaxysilane", Journal of
Organometallic chemistry, vol. 484, no. 1-2, 27 Dec. 1994 and
"Catalyst of hydrosililation Part XX. Unusual reaction of
vinyltriethaxysilane with triethaxysilane catalyzed by nickel
acetylacetonate", Journal of Organometallic chemistry, Lausane JOM,
15 Oct. 1991, describe a hydrosilylation reaction between two
silanes, vinyltriethoxysilane (EtO).sub.3--Si-Vi and
triethoxysilane (EtO).sub.3--SiH, in the presence of catalysts of
nickel (0) or (2). Silanes comprising the Si--H bond have as
substituents ethoxy Si--O-Et units that are very specific and very
different from the siloxanes according to this application which
have alkyl and siloxy substituents.
[0026] The invention also has for object, according to a third
aspect, the use of the previously described catalyst C as silicone
composition crosslinking catalyst.
[0027] The invention further has for purpose, according to a fourth
aspect, a silicone composition crosslinking method, characterised
in that it consists in heating the previously described composition
X to a temperature of between 70 and 200.degree. C., preferably
between 80 and 150.degree. C., and more preferably between 80 and
130.degree. C., as well as the crosslinked silicone material Y
obtained as such.
[0028] According to a particularly advantageous embodiment, the
organopolysiloxane A comprising, per molecule, at least two
C.sub.2-C.sub.6 alkenyl radicals bonded to silicon atoms,
comprises:
[0029] (i) at least two siloxyl units (A.1), which may be identical
or different, of the following formula:
W a Z b SiO 4 - ( a + b ) 2 ( A .1 ) ##EQU00001##
[0030] in which: [0031] a=1 or 2, b=0, 1 or 2 and a+b=1, 2 or 3;
[0032] the symbols W, which may be identical or different,
represent a C.sub.2-C.sub.6 linear or branched alkenyl group,
[0033] and the symbols Z, which may be identical or different,
represent a monovalent hydrocarbon group having from 1 to 30 carbon
atoms, and preferably chosen from the group consisting of alkyl
groups having from 1 to 8 carbon atoms and aryl groups containing
between 6 and 12 carbon atoms, and more preferably chosen from the
group consisting of a methyl, ethyl, propyl, 3,3,3-trifluoropropyl,
xylyl, tolyl and phenyl radical,
[0034] (ii) and optionally at least one siloxyl unit of the
following formula:
Z a 1 SiO 4 - a 2 ( A .2 ) ##EQU00002##
[0035] in which: [0036] a=0, 1, 2 or 3, [0037] the symbols Z.sup.1,
which may be identical or different, represent a monovalent
hydrocarbon group having from 1 to 30 carbon atoms and preferably
chosen from the group consisting of alkyl groups having from 1 to 8
carbon atoms inclusive and aryl groups containing between 6 and 12
carbon atoms, and more preferably chosen from the group consisting
of a methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl and
phenyl radical.
[0038] Advantageously, the radicals Z and Z.sup.1 are chosen from
the group consisting of a methyl and phenyl radical, and W is
chosen from the following list: vinyl, propenyl, 3-butenyl,
5-hexenyl, 9-decenyl, 10-undecenyl, 5,9-decadienyl and
6-11-dodecadienyle, and preferably W is a vinyl.
[0039] These organopolysiloxanes can have a linear, branched, or
cyclical structure. Their degree of polymerisation is, preferably,
between 2 and 5000.
[0040] When it is a question of linear polymers, the latter are
substantially constituted of siloxyl "D" units chosen from the
group consisting of the siloxyl units W.sub.2SiO.sub.2/2,
WZSiO.sub.2/2 and Z.sup.1.sub.2SiO.sub.2/2, and siloxyl units "M"
chosen from the group consisting of the siloxyl units
W.sub.3SiO.sub.1/2, WZ.sub.2SiO.sub.1/2, W.sub.2ZSiO.sub.1/2 and
Z.sup.1.sub.3SiO.sub.1/2. The symbols W, Z and Z.sup.1 are such as
described hereinabove.
[0041] By way of examples of "M" terminal units, mention can be
made of the trimethylsiloxy, dimethylphenylsiloxy,
dimethylvinylsiloxy or dimethylhexenylsiloxy groups.
[0042] By way of examples of "D" units, mention can be made of the
dimethylsiloxy, methylphenylsiloxy, methylvinylsiloxy,
methylbutenylsiloxy, methylhexenylsiloxy, methyldecenylsiloxy or
methyldecadienylsiloxy groups.
[0043] Said organopolysiloxanes A can be oils with a dynamic
viscosity of about 10 to 100,000 mPas at 25.degree. C., generally
about 10 to 70,000 mPas at 25.degree. C., or gums that have a
molecular weight of about 1,000,000 mPas or more at 25.degree.
C.
[0044] All of the viscosities of which it is a question in this
disclosure correspond to a magnitude of dynamic viscosity at
25.degree. C. referred to as "Newtonian", i.e. the dynamic
viscosity that is measured, in a manner known per se, with a
Brookfield viscometer with a shear speed gradient that is low
enough so that the viscosity measured is independent of the speed
gradient.
[0045] When entailing cyclical organopolysiloxanes, the latter are
constituted of siloxyl "D" units of the following formulas:
W.sub.2SiO.sub.2/2, Z.sub.2SiO.sub.2/2 or WZSiO.sub.2/2, which can
be of the dialkylsiloxy, alkylarylsiloxy, alkylvinylsiloxy,
alkylsiloxy type. Examples of such siloxyl units have already been
mentioned hereinabove. Said cyclic organopolysiloxanes A have a
viscosity of about 10 to 5000 mPas at 25.degree. C.
[0046] According to a preferred embodiment, the composition X
according to the invention comprises a second organopolysiloxane
compound comprising, per molecule, at least two C.sub.2-C.sub.6
alkenyl radicals bonded to silicon atoms, different from the
organopolysiloxane compound A, said second organopolysiloxane
compound being preferably divinyltetramethylsiloxane (dvtms).
[0047] Preferably, the organopolysiloxane compound A has a mass
content of Si-vinyl unit between 0.001 and 30%, preferably between
0.01 and 10%.
[0048] According to a preferred embodiment, the
organohydrogenopolysiloxane compound B is an organopolysiloxane
having at least two hydrogen atoms, per molecule, bonded to an
identical or different silicon atom and, preferably, having at
least three hydrogen atoms per molecule directly bonded to an
identical or different silicon atom.
[0049] Advantageously, the organohydrogenopolysiloxane compound B
is an organopolysiloxane comprising:
[0050] (i) at least two siloxyl units and, preferably, at least
three siloxyl units of the following formula:
H d Z e 3 SiO 4 - ( d + e ) 2 ( B .1 ) ##EQU00003##
[0051] in which: [0052] d=1 or 2, e=0, 1 or 2 and d+e=1, 2 or 3,
[0053] the symbols Z.sup.3, which may be identical or different,
represent a monovalent hydrocarbon group having from 1 to 30 carbon
atoms and preferably chosen from the group consisting of alkyl
groups having from 1 to 8 carbon atoms and aryl groups containing
between 6 and 12 carbon atoms, and more preferably chosen from the
group consisting of a methyl, ethyl, propyl, 3,3,3-trifluoropropyl,
xylyl, tolyl and phenyl radical, and
[0054] (ii) optionally at least one siloxyl unit of the following
formula:
Z c 2 SiO 4 - c 2 ( B .2 ) ##EQU00004##
[0055] in which: [0056] c=0, 1, 2 or 3, [0057] the symbols Z.sup.2,
which may be identical or different, represent a monovalent
hydrocarbon group having from 1 to 30 carbon atoms and preferably
chosen from the group consisting of alkyl groups having from 1 to 8
carbon atoms and aryl groups containing between 6 and 12 carbon
atoms, and more preferably chosen from the group consisting of a
methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl and
phenyl radical.
[0058] The organohydrogenopolysiloxane compound B can be formed
solely of siloxyl units of formula (B.1) or in addition comprise
units of formula (B.2). It can have a linear, branched, or cyclical
structure. The degree of polymerisation is preferably greater than
or equal to 2. More generally, it is less than 5000.
[0059] Examples of siloxyl units of formula (B.1) are in particular
the following units: H(CH.sub.3).sub.2SiO.sub.1/2,
HCH.sub.3SiO.sub.2/2 and H(C.sub.6H.sub.5)SiO.sub.2/2.
[0060] When it is a question of linear polymers, the latter are
substantially constituted: [0061] of siloxyl "D" units chosen from
the units of the following formulas Z.sup.2.sub.2SiO.sub.2/2 or
Z.sup.3HSiO.sub.2/2, and [0062] of siloxyl units "M" chosen from
the units of the following formulas Z.sup.2.sub.3SiO.sub.1/2 or
Z.sup.3.sub.2HSiO.sub.1/2.
[0063] These linear organopolysiloxanes can be oils with a dynamic
viscosity of about 1 to 100,000 mPas at 25.degree. C., generally
about 10 to 5000 mPas at 25.degree. C., or gums that have a
molecular weight of about 1,000,000 mPas or more at 25.degree.
C.
[0064] When entailing cyclical organopolysiloxanes, the latter are
constituted of siloxyl "D" units of the following formulas
Z.sup.2.sub.2SiO.sub.2/2 and Z.sup.3HSiO.sub.2,2, which can be of
the dialkylsiloxy or alkylarylsiloxy type or of Z.sup.3HSiO.sub.2/2
units only. They then have a viscosity of about 1 to 5000 mPas.
[0065] Examples of linear organohydrogenopolysiloxane compound B
are: dimethylpolysiloxanes with hydrogenodimethylsilyl ends,
dimethylhydrogenomethylpolysiloxanes with trimethylsilyl ends,
dimethylhydrogenomethylpolysiloxanes with hydrogenodimethylsilyl
ends, hydrogenomethylpolysiloxanes with trimethylsilyl ends, and
cyclic hydrogenomethylpolysiloxanes.
[0066] For organohydrogenopolysiloxane compound B, particular
preference is given to oligomers and polymers having the general
formula (B.3):
##STR00005##
[0067] in which: [0068] x and y are an integer varying between 0
and 200, [0069] the symbols R.sup.1 which are identical or
different, represent independently of one another: [0070] a linear
or branched alkyl radical containing 1 to 8 carbon atoms,
optionally substituted by at least one halogen, preferably
fluorine, with the alkyl radicals being, preferably, methyl, ethyl,
propyl, octyl and 3,3,3-trifluoropropyl, [0071] a cycloalkyl
radical containing between 5 and 8 cyclical carbon atoms, [0072] an
aryl radical containing between 6 and 12 carbon atoms, or [0073] an
aralkyl radical having an alkyl portion containing between 5 and 14
carbon atoms and an aryl portion containing between 6 and 12 carbon
atoms.
[0074] Particularly suitable for the invention as an
organohydrogenopolysiloxane compound B are the following
compounds:
##STR00006##
[0075] with a, b, c, d and e defined hereinbelow: [0076] in the
polymer of formula S1: [0077] 0.ltoreq.a.ltoreq.150, preferably
0.ltoreq.a.ltoreq.100, and more particularly 0.ltoreq.a.ltoreq.20,
and [0078] 1.ltoreq.b.ltoreq.90 preferably 10.ltoreq.b.ltoreq.80
and more particularly 30.ltoreq.b.ltoreq.70, [0079] in the polymer
of formula S2: 0.ltoreq.c.ltoreq.15 [0080] in the polymer of
formula S3: 5.ltoreq.d.ltoreq.200, preferably
20.ltoreq.d.ltoreq.100, and 2.ltoreq.e.ltoreq.90, preferably
10.ltoreq.e.ltoreq.70.
[0081] In particular, the organohydrogenopolysiloxane compound B
suitable for the invention is the compound of formula S1, where
a=0.
[0082] Preferably the organohydrogenopolysiloxane compound B has a
mass content of SiH unit between 0.2 and 91%, preferably between
0.2 and 50%.
[0083] In the framework of the invention, the proportions of
organopolysiloxane A and of organohydrogenopolysiloxane B are such
that the molar ratio of the hydrogen atoms bonded to the silicon
(Si--H) in the organohydrogenopolysiloxane B to the alkenyl
radicals bonded to the silicon (Si--CH.dbd.CH.sub.2) in the
organopolysiloxane A is between 0.2 and 20, preferably between 0.5
and 15, more preferably between 0.5 and 10 and even more preferably
between 0.5 and 5.
[0084] In order to allow for the obtaining of material Y according
to the invention, the composition X implements at least one
catalyst C which is a complex corresponding to the following
formula:
[Ni(L.sup.1).sub.2]
[0085] in which: [0086] the symbol Ni represents nickel at degree
of oxidation II, [0087] the symbols L.sup.1, which may be identical
or different, represent a ligand which is a .beta.-dicarbonylato
anion or the enolate anion of a .beta.-dicarbonylated compound.
[0088] Note that at least one portion of the inventive nature of
the invention, holds to the clever and advantageous selection of
the structure of the catalyst C.
[0089] According to another preferred embodiment of the invention,
the ligand L' is an anion derived from a compound of formula (1):
R.sup.1COCHR.sup.2COR.sup.3 (1)
[0090] in which: [0091] R.sup.1 and R.sup.3, which may be identical
or different, represent a C.sub.1-C.sub.30 linear, cyclic or
branched hydrocarbon radical, an aryl containing between 6 and 12
carbon atoms, or a radical-OR.sup.4 with R.sup.4 which represents a
C.sub.1-C.sub.30 linear, cyclic or branched hydrocarbon radical,
[0092] R.sup.2 is a hydrogen atom or a hydrocarbon radical,
preferably alkyl, comprising from 1 to 4 carbon atoms; with [0093]
R.sup.1 and R.sup.2 can be connected in order to form a
C.sub.5-C.sub.6 cycle, and [0094] R.sup.2 and R.sup.4 can be
connected in order to form a C.sub.5-C.sub.6 cycle.
[0095] Advantageously, the compound of formula (I) is chosen from
the group consisting of .beta.-diketones: 2,4-pentanedione (acac);
hexanedione-2,4; heptanedione-2,4; heptanedione-3,5; ethyl-3
pentanedione-2,4; methyl-5 hexanedione-2,4; octanedione-2,4;
octanedione-3,5; dimethyl-5,5 hexanedione-2,4; methyl-6
heptanedione-2,4; dimethyl-2,2 nonanedione-3,5; dimethyl-2,6
heptanedione-3,5; 2-acetylcyclohexanone (Cy-acac);
2,2,6,6-tetramethyl-3,5-heptanedione (TMHD);
1,1,1,5,5,5-hexafluoro-2,4-pentanedione (F-acac)]; benzoylacetone;
dibenzoyl-methane; 3-methyl-2,4-pentadione; 3-acetyl-pentane-2-one;
3-acetyl-2-hexanone; 3-acetyl-2-heptanone;
3-acetyl-5-methyl-2-hexanone; benzoylstearoylmethane;
benzoylpalmitoylmethane; octanoylbenzoylmethane;
4-t-butyl-4'-methoxy-dibenzoylmethane;
4,4'-dimethoxy-dibenzoylmethane and
4,4'di-tert-butyl-dibenzoylmethane, and preferably from
.beta.-diketones 2,4-pentanedione (acac) and
2,2,6,6-tetramethyl-3,5-heptanedione (TMHD).
[0096] According to another preferred embodiment of the invention,
the ligand .beta.-dicarbonylato L.sup.1 is a .beta.-ketoesterato
anion chosen from the group consisting of anions derived from the
following compounds: methyl, ethyl, n-propyl, isopropyl, n-butyl,
sec-butyl, isobutyl, tertiobutyl, isopentyl, n-hexyl, n-octyl,
methyl-1 heptyl, n-nonyl, n-decyl and n-dodecyl esters of
acetoacetic acid or those described in patent application
FR-A-1435882.
[0097] According to a particularly preferred embodiment, the
catalyst C is chosen from the complexes [Ni(acac).sub.2],
[Ni(TMHD).sub.2], [Ni(ketoester).sub.2] and [Ni(Rhodiastab
50).sub.2]. It is understood that in the formulas hereinabove
"acac" means the anion derived from the compound 2,4-pentanedione,
"THMD" means the anion derived from the compound
2,2,6,6-tetramethyl-3,5-heptanedione, "ketoester" means the anion
derived from a methyl ester of acetoacetic acid and "Rhodiastab 50"
means a mixture of anions derived from the compound
benzoylstearoylmethane, and of anions derived from the compound
benzoylpalmitoylmethane.
[0098] The catalyst C can in particular be present in the
composition X according to the invention in a content ranging from
0.001 to 10% molar of nickel per number of moles of C.sub.2-C.sub.6
alkenyl radicals bonded to silicon atoms of the organopolysiloxane
compound A, preferably between 0.01 to 7%, and more preferably
between 0.1 to 5%.
[0099] The composition X implemented in order to obtain the
material Y according to the invention is preferably free of a
catalyst based on platinum, palladium, ruthenium or rhodium. By the
term "free" of a catalyst other than the catalyst C, it is
understood that the composition X according to the invention
comprises less than 0.1% by weight of catalyst other than the
catalyst C, preferably less than 0.01% by weight, and more
preferably less than 0.001% by weight, in relation to the total
weight of the composition.
[0100] The composition X can advantageously include at least one
adhesion promoter D.
[0101] Without limitation, it can be considered that the adhesion
promoter D comprises: [0102] (D.1) at least one alkoxy organosilane
containing, per molecule, at least one C.sub.2-C.sub.6 alkenyl
group, or [0103] (D.2) at least one organosilicon compound
comprising at least one epoxy radical, or [0104] (D.3) at least one
metal chelate M and/or a metal alkoxide of general formula: M(OJ)n,
with n=valency of M and J=C.sub.1-C.sub.8 linear or branched
alkyl,
[0105] M being chosen from the group formed by: Ti, Zr, Ge, Li, Mn,
Fe, Al and Mg or mixtures thereof
[0106] In accordance with a preferred embodiment of the invention,
the alkoxy organosilane (D.1) of the adhesion promoter D is
selected from the products of the following general formula:
##STR00007##
[0107] formula in which: [0108] R1, R2, R3 are hydrogenated or
hydrocarbon radicals which are identical or different between them
and represent a hydrogen atom, a C.sub.1-C.sub.4 linear or branched
alkyl or a phenyl optionally substituted by at least one
C.sub.1-C.sub.3 alkyl, [0109] U is a C.sub.1-C.sub.4 linear or
branched alkylene, [0110] W is a valency bond, [0111] R.sup.4 and
R.sup.5 are radicals which are identical or different and represent
a C.sub.1-C.sub.4 linear or branched alkyl, [0112] x'=0 or 1, and
[0113] x=0 to 2.
[0114] Without limitation, it can be considered that the
vinyltrimethoxysilane is a particularly suitable compound
(D.1).
[0115] Regarding the organosilicon compound (D.2), it is provided
in accordance with the invention, to choose it:
[0116] a) either from the products (D.2a) having the following
general formula:
##STR00008##
[0117] formula in which: [0118] R.sup.6 is a C.sub.1-C.sub.4 linear
or branched alkyl radical, [0119] R.sup.7 is a linear or branched
alkyl radical, [0120] y is equal to 0, 1, 2 or 3, and [0121] X
being defined by the following formula:
##STR00009##
[0122] with: [0123] E and D which are identical or different
radicals chosen from C.sub.1-C.sub.4 linear or branched alkyls,
[0124] z which is equal to 0 or 1, [0125] R.sup.8, R.sup.9,
R.sup.10 which are identical or different radicals that represent a
hydrogen atom or a C.sub.1-C.sub.4 linear or branched alkyl, and
[0126] R.sup.8 and R.sup.9 or R.sup.10 that can alternatively form
together and with the two epoxy-carrying carbons, an alkyl cycle
having from 5 to 7 membered ring, or
[0127] b) or from the products (D.2b) constituted of
epoxyfunctional polydiorganosiloxanes comprising:
[0128] (i) at least one siloxyl unit of formula:
X p G q SiO 4 - ( p + q ) 2 ( D .2 bi ) ##EQU00005##
[0129] formula in which: [0130] X is the radical such as defined
hereinabove for the formula (D.2 a) [0131] G is a monovalent
hydrocarbon group, free of unfavourable action on the activity of
the catalyst and chosen from alkyl groups having from 1 to 8 carbon
atoms inclusive, optionally substituted by at least one halogen
atom, and as well as among the aryl groups containing between 6 and
12 carbon atoms, [0132] p=1 or 2, [0133] q=0, 1 or 2, [0134] p+q=1,
2 or 3, and
[0135] and (ii) optionally at least one siloxyl unit of
formula:
G t SiO 4 - r 2 ( D .2 bii ) ##EQU00006##
[0136] formula in which G has the same meaning as hereinabove and r
is equal to 0, 1, 2 or 3.
[0137] With regards to the last compound (D.3) of the adhesion
promoter D, the preferred products are those of which the metal M
of the chelate and/or of the alkoxide (D.3) is chosen from the
following list: Ti, Zr, Ge, Li or Mn. It is to be underlined that
titanium is more particularly preferred. It can be combined, for
example, with an alkoxy radical of the butoxy type.
[0138] The adhesion promoter D can be formed from: [0139] (D.1)
alone [0140] (D.2) alone [0141] (D.1)+(D.2)
[0142] Or according to two preferred embodiments from: [0143]
(D.1)+(D.3) [0144] (D.2)+(D.3)
[0145] and finally according to the most preferred embodiment:
(D.1)+(D.2)+(D.3).
[0146] According to the invention, an advantageous combination for
forming the adhesion promoter is the following: [0147]
vinyltrimethoxysilane (VTMO), 3-glycidoxypropyltrimethoxysilane
(GLYMO) and butyl titanate.
[0148] From a quantitative standpoint, it may be stated that the
proportions by weight between (D.1), (D.2) and (D.3), expressed as
a percentage by weight in relation to the total of the three, are
the following: [0149] (D.1).gtoreq.10, preferably between 15 and 70
and more preferably between 25 and 65, [0150] (D.2).ltoreq.90,
preferably between 70 and 15 and more preferably between 65 and 25,
and [0151] (D.3).gtoreq.1, preferably between 5 and 25 and more
preferably between 8 and 18,
[0152] with the understanding that the sum of these proportions in
(D.1), (D.2) and (D.3) is equal to 100%.
[0153] For better adhesive properties, the weight ratio (D.2):(D.1)
is preferably between 2:1 and 0.5:1, with the ratio 1:1 being more
particularly preferred.
[0154] Advantageously, the adhesion promoter D is present at a rate
of 0.1 to 10% by weight, preferably 0.5 to 5% by weight, and more
preferably between 1 to 3% by weight, in relation to the total
weight of all of the constituents of the composition X.
[0155] According to a particular embodiment, the composition X
implemented in order to obtain the material Y according to the
invention also comprises at least one charge E.
[0156] The charges E optionally contained in the compositions
according to the invention are preferably mineral. They can in
particular be siliceous. Being siliceous materials, they can play
the role of a reinforcing or semi-reinforcing charge. The siliceous
reinforcing charges are chosen from colloidal silicas, silica
powder for combustion and precipitation or mixtures thereof. These
powders have an average particle size generally less than 0.1 .mu.m
(micrometres) and a BET specific surface area greater than 30 m2/g,
preferably between 30 and 350 m2/g. The siliceous semi-reinforcing
charges such as diatomaceous or crushed quartz earth, can also be
used. With regards to non-siliceous mineral materials, they can
intervene as a semi-reinforcing mineral charge or filler. Examples
of these non-siliceous charges that can be used alone or in a
mixture are carbon black, titanium dioxide, aluminium oxide,
alumina hydrate, expanded vermiculite, unexpanded vermiculite,
calcium carbonate optionally with a fatty acid surface treatment,
zinc oxide, mica, talc, iron oxide, barium sulphate and slaked
lime. These charges have a granulometry that is generally between
0.001 and 300 .mu.m (micrometres) and a BET surface less than 100
m2/g. In a practical but not limiting way, the charges used can be
a mixture of quartz and of silica. The charges can be treated with
any suitable product. From a weight standpoint, it is preferred to
implement a quantity of charge between 1% and 50% by weight,
preferably between 1% and 40% by weight in relation to all of the
constituents of the composition.
[0157] The invention as such also has for object, in the framework
of this application, a crosslinkable composition X comprising:
[0158] at least one organopolysiloxane compound A comprising, per
molecule, at least two C.sub.2-C.sub.6 alkenyl radicals bonded to
silicon atoms, [0159] at least one organohydrogenopolysiloxane
compound B comprising, per molecule, at least two hydrogen atoms
bonded to an identical or different silicon atom, [0160] at least
one catalyst C which is a complex corresponding to the following
formula:
[0160] [Ni(L.sup.1).sub.2]
[0161] in which: [0162] the symbol Ni represents nickel at degree
of oxidation II, [0163] the symbols L.sup.1, which may be identical
or different, represent a ligand which is a .beta.-dicarbonylato
anion or the enolate anion of a .beta.-dicarbonylated compound,
[0164] optionally at least one adhesion promoter D and [0165]
optionally at least one charge E.
[0166] The composition X according to the invention can furthermore
include one or several usual functional additives. As families of
usual functional additives, mention can be made of: [0167] silicone
resins, [0168] adherence modulators, [0169] additives to increase
consistency, [0170] pigments, and [0171] heat-resistant,
oil-resistant or fire-resistant additives, for example metal
oxides.
[0172] Silicon resins are branched organopolysiloxane oligomers or
polymers that are well known and available off the shelf. They
have, in their structure, at least two different units chosen from
those of formula R.sub.3SiO.sub.1/2 (M unit), R.sub.2SiO.sub.2/2 (D
unit), RSiO.sub.3/2 (T unit) and SiO.sub.4/2 (Q unit), with at
least one of these units being a T or Q unit.
[0173] The radicals R are identical or different and are chosen
from C.sub.1-C.sub.6 linear or branched alkyl, hydroxyl, phenyl,
trifluoro-3,3,3 propyl radicals. As alkyl radicals, mention can for
example be made of methyl, ethyl, isopropyl, tertiobutyl and
n-hexyl radicals.
[0174] As examples of branched organopolysiloxane oligomers or
polymers, mention can be made of MQ resins, MDQ resins, TD resins
and MDT resins, the hydroxyl functions can be carried by the M, D
and/or T units. As an example of resins that are particularly well
suited, mentioned can be made of hydroxyl MDQ resins that have
their weight content in hydroxyl group between 0.2 and 10% by
weight.
[0175] The materials Y according to the invention can in particular
be obtained by introducing initially the catalyst C into the
reaction medium, then by adding the organopolysiloxane A under
stirring. Finally, the organohydrogenopolysiloxane compound B is
introduced and the temperature of the mixture is increased in order
to reach the crosslinking temperature. The mixture is maintained at
the crosslinking temperature until the stopping of the stirring due
to an increase in the viscosity of the mixture.
[0176] This invention also has for object a silicone composition
crosslinking method, characterised in that it consists in heating
the composition X such as defined hereinabove to a temperature of
between 70 and 200.degree. C., preferably between 80 and
150.degree. C., and more preferably between 80 and 130.degree.
C.
[0177] The composition X implemented in order to obtain the
material Y according to the invention has the advantage of not
being sensitive to air and of being able as such to be implemented
and in particular crosslink under a non-inert atmosphere, and in
particular in air.
[0178] This invention is shown in detail in the non-limiting
embodiments.
EXAMPLE 1: NICKEL BASED CATALYSTS FOR THE CROSSLINKING OF
DIVINYLTETRAMETHYLSILOXANE (DVTMS) WITH MD'.sub.50M
[0179] 1) Constituents
[0180] 1) Organopolysiloxane A: divinyltetramethylsiloxane (dvtms)
(1.073 mole of vinyl radicals bonded to the silicon for 100 g of
oil)
[0181] 2) Organohydrogenopolysiloxane B of formula: MD'.sub.50M
(1.58 mole of hydrogen atoms bonded to the silicon for 100 g of
oil), with: M: (CH.sub.3).sub.3SiO.sub.1/2; and D':
(CH.sub.3)HSiO.sub.2/2
[0182] 3) Catalysts (A), (B), (C), (D), (E) and (F):
##STR00010##
[0183] The catalysts (A), (B), (C) and (D) are available off the
shelf, for example under the references Strem purity >95% for
the compound [Ni(acac).sub.2], Strem purity >98% for the
compound [Ni(TMHD).sub.2].
[0184] The catalyst (E) is obtained via a synthesis that is well
known to those skilled in the art:
##STR00011##
[0185] The ketoester compound with R.sub.1=Methyl and
R.sub.2=Methoxy (supplier: Sigma-Aldrich) is in a first step
deprotonated using an equivalent of Bu-Li (supplier: Sigma-Aldrich)
at low temperature (-78.degree. C.). The salt obtained is
re-crystallised in diethylether. The obtained deprotonated ligand
(lithium salt) is added to a nickel chloride (NiCl.sub.2) in
solution in the THF at ambient temperature (12 h). After
decantation, filtration and concentration, the complex is
re-crystallised in the THF.
[0186] The complex [Ni(ketoester).sub.2] has the form of a green
apple solid.
[0187] The catalyst (F) is also obtained by synthesis well known to
those skilled in the art:
##STR00012##
[0188] The diketone compound with R.sub.1=Phenyl and
R.sub.2.dbd.C.sub.17H.sub.35 or C.sub.15H.sub.31 (supplier: Solvay)
is in a first step deprotonated using an equivalent of Bu-Li
(Supplier: Sigma-Aldrich) at low temperature (-78.degree. C.). The
salt obtained is re-crystallised in the diethylether. The obtained
deprotonated ligand (lithium salt) is added to a nickel chloride
(NiCl.sub.2) in solution in the THF at ambient temperature (12 h).
The complex obtained is viscous, with a green coloration. A step of
re-crystallisation makes it possible to lead to the obtaining of a
solid.
[0189] II) Formulations and Results:
[0190] For each formulation tested, the catalyst is weighed and
introduced into a Schlenk at ambient temperature and under inert
atmosphere when the complex is sensitive to air (case in particular
with Ni(0)), or into a glass flask when the complexes are stable in
air.
[0191] 1.87 g of divinyltetramethylsiloxane (dvtms) then 1.27 g of
oil MD'.sub.50M are then introduced. The flask (or Schlenk) is
placed under stirring in an oil bath that will be heated to the
desired reaction temperature.
[0192] The ratio R corresponds to the molar ratio of the hydrogen
atoms bonded to the silicon (Si--H) in the
organohydrogenopolysiloxane (MD'.sub.50M) to the alkenyl radicals
(here vinyl) bonded to the silicon (Si--CH.dbd.CH.sub.2) in the
organopolysiloxane (dvtms).
[0193] The start of crosslinking is measured. The start of
crosslinking is defined as being the stopping of the stirring due
to an increase in the viscosity of the medium.
TABLE-US-00001 TABLE 1 Reaction % mol of Start of Catalyst
temperature catalyst.sup.(1) Ratio R Atmosphere crosslinking
Formulation 1 Ni(COD).sub.2] 110.degree. C. 0.25% 1:1 Inert 3 h 20
(comparative) (under argon) Formulation 2 [Ni(TMHD).sub.2]
110.degree. C. 0.25% 1:1 Non-inert 1 h (invention) Formulation 3
Ni(II) 110.degree. C. 0.25% 1:1 Non-inert 45 h (comparative)
stearate Formulation 4 [Ni(acac).sub.2] 110.degree. C. 0.25% 1:1
Non-inert 2 h (invention) .sup.(1)Expressed as a molar % of nickel
per number of moles of vinyl radicals bonded to the silicon
(Si--CH.dbd.CH.sub.2) in dvtms
[0194] The comparative formulation 1 comprising a complex of Ni(0)
crosslinks after 3h20 but must be maintained under inert
atmosphere. Indeed, under a non-inert atmosphere, the complex
breaks down very quickly, even before the start of the reaction,
during the rise in temperature.
[0195] The formulations 2 and 4 according to the invention where
the catalyst is a complex of Ni(II) having two .beta.-dicarbonyl
ligands crosslink in 1 to 2 h.
[0196] The comparative formulation 3, implementing a complex of
Ni(II) having stearate ligands, crosslinks only after 45 h.
[0197] Furthermore the nickel catalysts according to the invention
were tested in the following different operating conditions:
TABLE-US-00002 TABLE 2 Reaction % mol of Start of Catalyst
temperature catalyst.sup.(1) Ratio R Atmosphere crosslinking
Formulation 5 [Ni(TMHD).sub.2] 90.degree. C. 0.25% 1:1 Non-inert
Less than (invention) 15 h Formulation 6 [Ni(acac).sub.2]
90.degree. C. 0.25% 1:1 Non-inert Less than (invention) 15 h
Formulation 7 [Ni(TMHD).sub.2] 110.degree. C. 0.125% 1:1 Non-inert
Less than (invention) 15 h Formulation 8 [Ni(acac).sub.2]
110.degree. C. 0.125% 1:1 Non-inert Less than (invention) 15 h
Formulation 9 [Ni(ketoester).sub.2] 90.degree. C. 0.25% 1:1
Non-inert 3.5 h (invention) Formulation 10 [Ni(ketoester).sub.2]
90.degree. C. 0.125% 1:1 Non-inert Less than (invention) 15 h
.sup.(1)Expressed as a molar % of nickel per number of moles of
vinyl radicals bonded to the silicon (Si--CH.dbd.CH.sub.2) in
dvtms
[0198] The formulations 5 and 6 according to the invention show
that a crosslinking is obtained at 90.degree. C., even if this
crosslinking is slower than that observed for formulations 2 and 4
carried out at 110.degree. C.
[0199] The formulations 7, 8 and 10 according to the invention show
that a crosslinking is obtained at 0.125% molar of catalyst, even
if this crosslinking is slower than that observed for formulations
2, 4 and 9 comprising 0.25% molar of catalyst.
EXAMPLE 2: NICKEL BASED CATALYSTS FOR THE CROSSLINKING OF M.sup.VI
D.sub.70 M.sup.VI WITH MD'.sub.50M
I) Constituents
[0200] 1) Organopolysiloxane A of formula M.sup.viD.sub.70M (0.038
mole of vinyl radicals bonded to the silicon for 100 g of oil),
with: Vi=Vinyl; M.sup.vi: (CH.sub.3).sub.2ViSiO.sub.1/2 and D:
(CH.sub.3).sub.2SiO.sub.2/2
[0201] 2) Organohydrogenopolysiloxane B of formula: MD'.sub.50M
(1.58 mole of hydrogen atoms bonded to the silicon for 100 g of
oil), with: M: (CH.sub.3).sub.3SiO.sub.1/2; and D':
(CH.sub.3)HSiO.sub.2/2
[0202] 3) Catalysts (A), (B), (C), (D), (E) and (F) such as defined
in example 1.
II) Formulations and results:
[0203] For each formulation tested, the catalyst is weighed and
introduced into a Schlenk at ambient temperature and under inert
atmosphere when the complex is sensitive to air (case with Ni(0)),
or into a glass flask when the complexes are stable in air.
[0204] Oil M.sup.viD.sub.70M.sup.v1 then oil MD'.sub.50M were then
introduced.
[0205] For a ratio R corresponding to the molar ratio of the
hydrogen atoms bonded to the silicon (Si--H) in the
organohydrogenopolysiloxane (MD'.sub.50M) to the alkenyl radicals
(here vinyl) bonded to the silicon (Si--CH.dbd.CH.sub.2) in the
organopolysiloxane (M.sup.viD.sub.70M.sup.vi) of 1:1, 4.39 g of oil
M.sup.viD.sub.70M.sup.vi then 0.105 g of oil MD'.sub.50M were
introduced.
[0206] The content in oil M.sup.viD.sub.70M.sup.vi and in oil
MD'.sub.50M were adjusted according to the ratio R desired.
[0207] The flask (or Schlenk) is placed under stirring in an oil
bath that will be heated to the desired reaction temperature.
[0208] The ratio R corresponds to the molar ratio of the hydrogen
atoms bonded to the silicon (Si--H) in the
organohydrogenopolysiloxane (MD'.sub.50M) to the alkenyl radicals
(here vinyl) bonded to the silicon (Si--CH.dbd.CH2) in the
organopolysiloxane (M.sup.viD.sub.70M.sup.vi).
[0209] The start of crosslinking is measured.
[0210] Study of the Duration of Crosslinking
TABLE-US-00003 TABLE 3 Reaction % mol of Start of Catalyst
temperature catalyst.sup.(1) Ratio R Atmosphere crosslinking
Formulation 11 [Ni(COD).sub.2] 110.degree. C. 4% 1:1 Inert 2 h 50
(comparative) (under argon) Formulation 12 [Ni(TMHD).sub.2]
110.degree. C. 4% 1:1 Non-inert 1 h 50 (invention) Formulation 13
Ni(II) 110.degree. C. 4% 1:1 Non-inert No (comparative) stearate
crosslinking at 48 h Formulation 14 [Ni(acac).sub.2] 110.degree. C.
4% 1:1 Non-inert 2 h 20 (invention) .sup.(1)Expressed as a molar %
of nickel per number of moles of vinyl radicals bonded to the
silicon (Si--CH.dbd.CH.sub.2) in the organopolysiloxane
(M.sup.viD.sub.70M.sup.vi)
[0211] The formulation 11 comprising a complex of Ni(0) crosslinks
after 2h50 but must be maintained under inert atmosphere. Indeed,
as already indicated in example 1, the complex breaks down very
quickly under a non-inert atmosphere, even before the start of the
reaction.
[0212] The formulations 12 and 14 according to the invention where
the catalyst is a complex of Ni(II) having two .beta.-dicarbonyl
ligands crosslink after about 1h50 to 2h20.
[0213] The comparative formulation 13, implementing a complex of
Ni(II) having stearate ligands, still does not crosslink after 48
h.
[0214] Furthermore the catalysts (E) and (F) according to the
invention were tested in the following different operating
conditions:
TABLE-US-00004 TABLE 4 Reaction % mol of Ratio Start of Catalyst
temperature catalyst.sup.(1) R crosslinking Formulation
[Ni(ketoester).sub.2] 110.degree. C. 2% 1:1 5 h 15 (invention)
Formulation [Ni(ketoester).sub.2] 110.degree. C. 1.6% 1.6:1 30 min
16 (invention) Formulation [Ni(Rhodiastab).sub.2] 110.degree. C.
0.8% 1.6:1 3 h 17 (invention) .sup.(1)Expressed as a molar % of
nickel per number of moles of vinyl radicals bonded to the silicon
(Si--CH.dbd.CH.sub.2) in the organopolysiloxane
(M.sup.viD.sub.70M.sup.vi)
[0215] Study of the Effect of the Temperature
TABLE-US-00005 TABLE 5 Effect of the increase in temperature (1)
Reaction % mol of Start of Catalyst temperature catalyst.sup.(1)
Ratio R Atmosphere crosslinking Formulation 18 [Ni(TMHD).sub.2]
90.degree. C. 2% 1:1 Non-inert 17 h (invention) Formulation 19
[Ni(TMHD).sub.2] 110.degree. C. 2% 1:1 Non-inert 2 h 20 (invention)
Formulation 20 [Ni(TMHD).sub.2] 130.degree. C. 2% 1:1 Non-inert 10
min (invention) .sup.(1)Expressed as a molar % of nickel per number
of moles of vinyl radicals bonded to the silicon
(Si--CH.dbd.CH.sub.2) in the organopolysiloxane
(M.sup.viD.sub.70M.sup.vi)
TABLE-US-00006 TABLE 6 Effect of the increase in temperature (2)
Reaction % mol of Start of Catalyst temperature catalyst.sup.(1)
Ratio R Atmosphere crosslinking Formulation 21 [Ni(acac).sub.2]
90.degree. C. 1.6% 3.1:1 Non-inert 3 h (invention) Formulation 22
[Ni(acac).sub.2] 110.degree. C. 1.6% 3.1:1 Non-inert 20 min
(invention) Formulation 23 [Ni(acac).sub.2] 130.degree. C. 1.6%
3.1:1 Non-inert 8 min (invention) .sup.(1)Expressed as a molar % of
nickel per number of moles of vinyl radicals bonded to the silicon
(Si--CH.dbd.CH.sub.2) in the organopolysiloxane
(M.sup.viD.sub.70M.sup.vi)
[0216] The formulations 18 to 23 according to the invention show
that the increase in temperature makes it possible to significantly
reduce crosslinking time.
[0217] Study of the Effect of the Concentration in Catalyst
TABLE-US-00007 TABLE 7 effect of the increase in the concentration
of catalyst (1) Reaction % mol of Start of Catalyst temperature
catalyst.sup.(1) Ratio R Atmosphere crosslinking Formulation 24
[Ni(TMHD).sub.2] 110.degree. C. 1% 1:1 Non-inert 26 h (invention)
Formulation 19 [Ni(acac).sub.2] 110.degree. C. 2% 1:1 Non-inert 2 h
20 (invention) Formulation 12 [Ni(acac).sub.2] 110.degree. C. 4%
1:1 Non-inert 1 h 50 (invention) .sup.(1)Expressed as a molar % of
nickel per number of moles of vinyl radicals bonded to the silicon
(Si--CH.dbd.CH.sub.2) in the organopolysiloxane
(M.sup.viD.sub.70M.sup.vi)
TABLE-US-00008 TABLE 8 effect of the increase in the concentration
of catalyst (2) Reaction % mol of Start of Catalyst temperature
catalyst.sup.(1) Ratio R Atmosphere crosslinking Formulation 25
[Ni(TMHD).sub.2] 110.degree. C. 0.16% 3.1:1 Non-inert 5 h
(invention) Formulation 26 [Ni(acac).sub.2] 110.degree. C. 0.4%
3.1:1 Non-inert 1 h 30 (invention) Formulation 27 [Ni(acac).sub.2]
110.degree. C. 0.8% 3.1:1 Non-inert 1 h 20 (invention) Formulation
28 [Ni(acac).sub.2] 110.degree. C. 1.6% 3.1:1 Non-inert 20 min
(invention) Formulation 29 [Ni(acac).sub.2] 110.degree. C. 3.1%
3.1:1 Non-inert 20 min (invention) .sup.(1)Expressed as a molar %
of nickel per number of moles of vinyl radicals bonded to the
silicon (Si--CH.dbd.CH.sub.2) in the organopolysiloxane
(M.sup.viD.sub.70M.sup.vi)
[0218] The formulations 12, 19 and 24 to 29 according to the
invention show that the increase in the concentration of catalyst
makes it possible to significantly reduce crosslinking time. The
formulation 25 further shows that the crosslinking can be observed
even with very low catalyst contents, which makes it possible to
prevent or limit the coloration of the crosslinked material.
[0219] Study of the Effect of the Ratio R
TABLE-US-00009 TABLE 9 Effect of the ratio R(1) Reaction % mol of
Ratio Start of Catalyst temperature catalyst.sup.(1) R crosslinking
Formulation 14 [Ni(acac).sub.2] 110.degree. C. 4% 1:1 2 h 20
(invention) Formulation [Ni(acac).sub.2] 110.degree. C. 4% 2:1 1 h
50 14a (invention) .sup.(1)Expressed as a molar % of nickel per
number of moles of vinyl radicals bonded to the silicon
(Si--CH.dbd.CH.sub.2) in the organopolysiloxane
(M.sup.viD.sub.70M.sup.vi)
TABLE-US-00010 TABLE 10 Effect of the ratio R (2) Reaction % mol of
Ratio Start of Catalyst temperature catalyst.sup.(1) R crosslinking
Formulation 30 [Ni(acac).sub.2] 110.degree. C. 1.6% 0.8:1 3 h
(invention) Formulation 31 [Ni(acac).sub.2] 110.degree. C. 1.6%
3.1:1 20 min (invention) .sup.(1)Expressed as a molar % of nickel
per number of moles of vinyl radicals bonded to the silicon
(Si--CH.dbd.CH.sub.2) in the organopolysiloxane
(M.sup.viD.sub.70M.sup.vi)
[0220] The crosslinkings are carried out under a non-inert
atmosphere. The formulations 14 and 14A, and 30 and 31 show that
the increase in the ratio R makes it possible to reduce
crosslinking time.
[0221] Duration of Crosslinking of Catalysts (A), (B), (E) and
(F)
[0222] Finally, the crosslinking for the catalysts (A), (B), (E)
and (F) was tested with a ratio R of 1.6:1. The results are
presented in table 8.
TABLE-US-00011 TABLE 8 Reaction % mol of Ratio Start of Catalyst
temperature catalyst.sup.(1) R crosslinking Formulation
[Ni(acac).sub.2] 110.degree. C. 1.6% 1.6:1 25-30 min 32 (invention)
Formulation [Ni(TMHD).sub.2] 110.degree. C. 1.6% 1.6:1 25-30 min 33
(invention) Formulation [Ni(cetoester).sub.2] 110.degree. C. 1.6%
1.6:1 30 min 34 (invention) Formulation [Ni(Rhodiastab).sub.2]
110.degree. C. 1.6% 1.6:1 2 h 30-3 h 35 (invention)
.sup.(1)Expressed as a molar % of nickel per number of moles of
vinyl radicals bonded to the silicon (Si--CH.dbd.CH.sub.2) in the
organopolysiloxane (M.sup.viD.sub.70M.sup.vi)
[0223] The crosslinkings are carried out under a non-inert
atmosphere. The formulations 32 to 35 show that the crosslinking is
observed for different nickel based catalysts at the degree of
oxidation (II).
EXAMPLE 3: CATALYST [NI(TMHD).sub.2] FOR THE CROSSLINKING OF
M.sup.VI D.sub.350 M.sup.VI WITH MD'.sub.50M
I) Constituents
[0224] 1) Organopolysiloxane A of formula
M.sup.viD.sub.350M.sup.vi, with: Vi=Vinyl; M.sup.vi:
(CH.sub.3).sub.2ViSiO.sub.1/2 and D:
(CH.sub.3).sub.2SiO.sub.2/2
[0225] 2) Organohydrogenopolysiloxane B of formula: MD'.sub.50M
(1.58 mole of hydrogen atoms bonded to the silicon for 100 g of
oil), with: M: (CH.sub.3).sub.3SiO.sub.1/2; and D':
(CH.sub.3)HSiO.sub.2/2
[0226] 3) Catalyst (A) such as defined in the example 1.
II) Formulations and Results:
[0227] We weighed 12.4 g of M.sup.viD.sub.350M.sup.vi with:
Vi=Vinyl; M.sup.vi: (CH.sub.3).sub.2ViSiO.sub.1/2 and D:
(CH.sub.3).sub.2SiO.sub.2/2 and 0.6 g of MD'.sub.50M (1.58 mole of
hydrogen atoms bonded to the silicon for 100 g of oil), with:
[0228] M: (CH.sub.3).sub.3SiO.sub.1/2; and D':
(CH.sub.3)HSiO.sub.2/2
[0229] The ratio R corresponding to the molar ratio of the hydrogen
atoms bonded to the silicon (Si--H) in the
organohydrogenopolysiloxane (MD'.sub.50M) on the alkenyl radicals
(here vinyl) bonded to the silicon (Si--CH.dbd.CH.sub.2) in the
organopolysiloxane (M.sup.viD.sub.350M.sup.vi) of 10:1.
[0230] 5 mol % of catalyst [Ni(TMHD)2] (expressed as a molar % of
nickel per number of moles of vinyl radicals bonded to the silicon
(Si--CH.dbd.CH.sub.2) in the organopolysiloxane
(M.sup.viD.sub.350M.sup.vi)) is dissolved at ambient temperature in
the oil MD'.sub.50M and the mixture is incorporated at ambient
temperature in the oil M.sup.viD.sub.350M.sup.vi. The whole is
placed in a Teflon mould then into an oven at 110.degree. C.
[0231] After two hours, the crosslinked material is demoulded and
its hardness (in Shore A) measured. The material has a hardness of
9 in Shore A degrees.
[0232] This example makes it possible to show that the implementing
of catalysts claimed in crosslinking reactions of
organopolysiloxane compound A with an organohydrogenopolysiloxane
compound B allows for the obtaining of materials Y of which the
hardness can be measured.
* * * * *