U.S. patent application number 12/142318 was filed with the patent office on 2008-10-16 for process for preparing functionalized polyorganosiloxane resins by redistribution in the presence of triflic acid and/or of at least one derivative thereof and of a nonbasic inert filler.
This patent application is currently assigned to BLUESTAR SILICONES FRANCE SAS. Invention is credited to Fernande Boisson, Lucile Gambut, Gerard Mignani.
Application Number | 20080255292 12/142318 |
Document ID | / |
Family ID | 27839203 |
Filed Date | 2008-10-16 |
United States Patent
Application |
20080255292 |
Kind Code |
A1 |
Boisson; Fernande ; et
al. |
October 16, 2008 |
Process for preparing functionalized polyorganosiloxane resins by
redistribution in the presence of triflic acid and/or of at least
one derivative thereof and of a nonbasic inert filler
Abstract
The invention provides a method for preparing functionalized
polyorganosiloxane resins (POS) comprising units M:
(R.sub.3SiO.sub.1/2), Q: (SiO.sub.4/2) and M':
(Y.sub.aR.sub.3-aSiO.sub.1/2) and optionally D:
(R.sub.2SiO.sub.2/2) and/or D': (RYSiO.sub.2/2) and T:
(RSiO.sub.3/2) and/or T': (YSiO.sub.3/2), wherein in said units R
is C.sub.1-C.sub.10 alkyl or C.sub.8-C.sub.12 aryl and Y is a
functional group (such as Si--H), by redistributing POS resins,
using POSf bearing functional groups M' and/or D' and/or in the
presence of an acid catalyst such as triflic acid or one of its
derivatives and a non-basic inert filler: carbon black,
diatomaceous earth, zeolite or acid or neutral oxide
(Al.sub.2O.sub.3, Na.sub.2O, TiO.sub.2, MgO, silica). The invention
also provides said catalyst system.
Inventors: |
Boisson; Fernande;
(Villeurbanne, FR) ; Gambut; Lucile; (Lyon,
FR) ; Mignani; Gerard; (Lyon, FR) |
Correspondence
Address: |
BUCHANAN, INGERSOLL & ROONEY PC
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Assignee: |
BLUESTAR SILICONES FRANCE
SAS
Lyon Cedex
FR
|
Family ID: |
27839203 |
Appl. No.: |
12/142318 |
Filed: |
June 19, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10509060 |
Jun 17, 2005 |
7411028 |
|
|
PCT/FR03/00888 |
Mar 20, 2003 |
|
|
|
12142318 |
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Current U.S.
Class: |
524/448 ;
524/588 |
Current CPC
Class: |
C08G 77/10 20130101;
C08G 77/08 20130101 |
Class at
Publication: |
524/448 ;
524/588 |
International
Class: |
C08L 83/06 20060101
C08L083/06; C08K 3/34 20060101 C08K003/34 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 26, 2002 |
FR |
02/03769 |
Claims
1. A process for preparing functionalized polyorganosiloxane (POS)
resins comprising units M: (R.sub.3SiO.sub.1/2), Q: (SiO.sub.4/2)
and M': (Y.sub.aR.sub.3-aSiO.sub.1/2) and optionally D:
(R.sub.2SiO.sub.2/2) and/or D': (RYSiO.sub.2/2) and T:
(RSiO.sub.3/2) and/or T': (YSiO.sub.3/2), wherein: the radicals R,
which are identical or different, represent C.sub.1-C.sub.10 alkyl
or C.sub.8-C.sub.12 aryl; and the radicals Y, which are identical
or different, represent a functional group Y selected from the
group consisting of hydrogen, alkenyl, alkynyl, aryl, (alkyl)epoxy,
ether, polyether, carboxylic acid, amide, amine, halide, alcohol,
thiol and other sulfur derivative; said process comprising
conducting a redistribution reaction between a POS resin and a POSf
compound bearing functional units M' and/or D' and/or T', as
defined above, in the presence of an acid catalyst, wherein: at
least one catalyst has formula (I) below:
(C.sub.mF.sub.2m+1SO.sub.2).sub.nA (I) wherein: m is an integer
greater than or equal to 1; n is an integer equal to 1 or 2 and A
represents OH, NH.sub.2 or NH with: (i) n=1 and A=OH; or (ii) n=1
and A=NH.sub.2 or NHR with R being a radical of SO.sub.2-Z type,
with Z being a group other than C.sub.mF.sub.2m+1; or (iii) n=2 and
A=NH; and wherein said catalyst is in the presence of a nonbasic
inert filler.
2. The process as claimed in claim 1, wherein the nonbasic inert
filler is carbon black, a diatomaceous earth, or an acidic or
neutral oxide, or a mixture thereof.
3. The process as claimed in claim 1, wherein the acidic or neutral
oxide is Al.sub.2O.sub.3, Na.sub.2O, TiO.sub.2, MgO, silica or
zeolite, or a mixture thereof.
4. The process as claimed in claim 1, wherein Y is phenyl.
5. The process as claimed in claim 1, wherein the catalyst is
triflic acid (TFOH) of formula (I) (i) with m=1 and/or the
trifluoromethanesulfonimide acid (TFSI) of formula (I) (iii) with
m=1.
6. The process as claimed in claim 2, wherein the catalyst is
triflic acid (TFOH) of formula (I) (i) with m=1 and/or the
trifluoromethanesulfonimide acid (TFSI) of formula (I) (iii) with
m=1.
7. The process as claimed in claim 1, wherein the catalyst is
supported on the nonbasic inert filler, wherein the concentration
of acid catalyst (I) is between 1 ppm and 2% by weight relative to
the starting resin and wherein the catalyst (I)/inert filler
support mass ratio is between 0.1 and 10.
8. The process as claimed in claim 7, wherein the inert filler
support is carbon black.
9. The process as claimed in claim 7, wherein the catalyst
(I)/inert filler support mass ratio is of the order of 1.
10. The process as claimed in claim 9, wherein the inert filler
support is carbon black.
11. The process as claimed in claim 7, wherein the catalyst is
triflic acid (TFOH) of formula (I) (i) with m=1 and/or the
trifluoromethanesulfonimide acid (TFSI) of formula (I) (iii) with
m=1.
12. The process as claimed in claim 11, wherein the inert filler
support is carbon black.
13. The process as claimed in claim 1, comprising the following
essential steps: (1) combining the starting POS resin, the POSf
bearing functional units, the acid catalyst (1) and the nonbasic
inert filler in an organic solvent; (2) reacting at a temperature
.theta.r greater than or equal to room temperature and less than or
equal to the boiling point of the solvent; (3) optionally quenching
the reaction by adding an agent for neutralizing the acid catalyst
(I); and (4) removing the inert filler from the reaction
medium.
14. The process as claimed in claim 13, wherein the inert filler
comprises carbon black, and/or wherein the reaction temperature is
between 50.degree. C. and 100.degree. C., and/or wherein the inert
filler is removed from the reaction medium by filtration.
15. The process as claimed in claim 13, wherein the acid catalyst
is triflic acid (TFOH) of formula (I) (i) with m=1 and/or the
trifluoromethanesulfonimide acid (TFSI) of formula (I) (iii) with
m=1.
16. The process as claimed in claim 15, wherein the inert filler
comprises carbon black, and/or wherein the reaction temperature is
between 50.degree. C. and 100.degree. C., and/or wherein the inert
filler is removed from the reaction medium by filtration.
17. The process as claimed in claim 13, wherein the organic solvent
is provided in the reaction medium by means of a solution of
starting POS resin in said solvent, and wherein the nonbasic inert
filler is in the form of powder dispersed in the POSf bearing
functional units.
18. The process as claimed in claim 13, wherein the organic solvent
is xylene or toluene, and/or wherein the nonbasic inert filler is
carbon black.
19. The process as claimed in claim 1, wherein Y.dbd.H or alkenyl
in the functional units M' and/or D' and/or T' of the POSf, and
wherein, after the redistribution, other functionalization radicals
Y.sub.1 bearing at least one unsaturation or at least one Si--H
unit are grafted by hydrosilylation onto the .ident.Si--H or
--Si-alkenyl units, respectively, of the redistributed resin.
20. The process as claimed in claim 19, wherein other
functionalization radicals Y.sub.1 bearing at least one ethylenic
unsaturation are grafted by hydrosilylation onto the .ident.Si--H
or .ident.Si-alkenyl units, respectively, of the redistributed
resin.
21. The process as claimed in claim 13, wherein Y.dbd.H or alkenyl
in the functional units M' and/or D' and/or T' of the POSf, and
wherein, after the redistribution, other functionalization radicals
Y.sub.1 bearing at least one unsaturation or at least one Si--H
unit are grafted by hydrosilylation onto the .ident.Si--H or
.ident.Si-alkenyl units, respectively, of the redistributed
resin.
22. The process as claimed in claim 21, wherein other
functionalization radicals Y.sub.1 bearing at least one ethylenic
unsaturation are grafted by hydrosilylation onto the .ident.Si--H
or .ident.Si-alkenyl units, respectively, of the redistributed
resin.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 10/509,060, filed Jun. 17, 2005, now allowed, which is the U.S.
national stage of International Application No. PCT/FR03/00888,
filed Mar. 20, 2003, and claims priority under 35 U.S.C. .sctn. 119
(a)-(d) of French Patent Application No. 02/03769, filed Mar. 26,
2002, said applications being incorporated by reference herein in
their entireties and relied upon.
[0002] Reference is also made to commonly assigned application Ser.
No. 10/509,071 (Attorney Docket No. 0070681-000015), which is the
U.S. national stage of International Appln. No. PCT/FR03/00889,
filed Mar. 20, 2003, and which was concurrently filed with parent
application Ser. No. 10/509,060 on Jun. 17, 2005, as well as its
continuation application Ser. No. ______ (Attorney Docket No.
0070681-000099) concurrently filed herewith.
[0003] The field of the invention is that of the production of
silicone or polyorganosiloxane resins, referred to hereinbelow as
POS resins. The POS resins more especially targeted are those
comprising siloxyl units M: (R.sub.3SiO.sub.1/2) and optionally D:
(R.sub.2SiO.sub.2/2) and/or T: (RSiO.sub.3/2), said resins moreover
being functionalized, i.e. they comprise units M':
(Y.sub.aR.sub.3-aSiO.sub.1/2) and optionally D': (RYSiO.sub.2/2)
and/or T: (YSiO.sub.3/2); Y representing in these formulae a
functional group, for example a hydrogen or a vinyl, R a
hydrocarbon-based group and a=1 or 2.
[0004] These functional silicone resins MQ may be liquid or solid
at room temperature. They have been known for a very long time and
are currently used in many applications, for instance in electrical
insulating varnishes, heat-resistant coatings, encapsulating
materials for semiconductor components, etc.
[0005] The functional MQ POS resins (MM'Q) whose production forms
the subject of the present invention may also comprise siloxyl
units D and/or T, or even functionalized siloxyl units D' and/or
T'.
[0006] The main routes of access to functional MQ resins are
currently processes of condensation/hydrolysis starting with sodium
silicate or alkyl silicate (U.S. Pat. No. 2,676,182, U.S. Pat. No.
2,814,601, U.S. Pat. No. 2,857,356, U.S. Pat. No. 4,707,531). These
techniques are not without drawbacks, especially in terms of ease
of use, cost and production of ecotoxic and/or hazardous
effluents.
[0007] However, an alternative, which is attractive in principle,
to these condensation/hydrolysis techniques exists, namely the
redistribution of POS oils in a POS resin comprising MQ units.
[0008] By way of illustration of this route of functionalization of
resins of MQ type by redistribution, mention may be made of U.S.
Pat. No. 4,774,310, U.S. Pat. No. 5,494,979 (.apprxeq.EP-A-0 617
094) and U.S. Pat. No. 5,510,430.
[0009] Patent U.S. Pat. No. 4,774,310 describes the preparation of
Si--H functionalized resins by redistribution of
tetramethyldisiloxane (M'.sub.2) in an MQ resin dissolved in an
organic solvent, in the presence of triflic acid or
perfluoroalkanesulfonic acid (TFOH). The reaction medium is heated
to a temperature of between 50 and 100.degree. C. and the triflic
acid catalyst is then neutralized with NaHCO.sub.3. The MM'Q resins
thus obtained may react with organic or organosiloxane substances
bearing olefin unsaturation (column 2, line 66 to column 3, line
3). Said patent also makes a vague and general allusion to
supported acid catalysts (column 2, line 18).
[0010] Patent U.S. Pat. No. 5,494,979 (.apprxeq.EP-A-0 617 094)
discloses the preparation of MQ resins functionalized with acrylate
radicals, by redistribution of polydiorganosiloxane oils bearing
units D and units D.sup.acrylate:MD.sup.acrylate.sub.xD.sub.yM.
This redistribution is performed using a xylene solution of
commercial MQ resin, using triflic acid as preferred acid catalyst.
The POS MD.sup.acrylate.sub.xD.sub.yM used is as described in
example 2 of German patent 3 810 140. This preparation of
acrylate-functionalized MQ resins also includes steps of
neutralization, for example with sodium carbonate, and then of
removal of the solid residues by filtration.
[0011] American patent U.S. Pat. No. 5,510,430 concerns the
functionalization of resins of MQ type with a whole range of
functional groups, for example aryl, alkyl, vinyl or Si--H. The
functionalization process used is based on the redistribution of
disiloxanes and chlorosilanes. The examples more specifically
disclose the redistribution of MQ resins of formula:
[(CH.sub.3).sub.3SiO.sub.1/2].sub.0.65[SiO.sub.4/2].sub.1 dissolved
in toluene, by placing in contact with tetramethyldisiloxane and an
acid catalyst that may be a phosphonitrile chloride, a linear
phosphazene or triflic acid (example 6). This is therefore a
redistribution MQ+M'.sub.2 at the reflux temperature of the
solvent, with quenching of the reaction by using methanol,
resulting in precipitation. Filtration and washing steps are then
performed.
[0012] It emerges from this review of the prior art that the
redistribution of MQ resins using functional oligo-organosiloxanes
or functional polyorganosiloxanes, in the presence of triflic acid,
does not make reference to the use of any cocatalyst, and in any
case does not at all mention the use of an inert filler such as
carbon black in combination with triflic acid.
[0013] Moreover, it would be entirely desirable to improve the
known processes, especially in terms of functionalization yields
and degrees of conversion of the POSs used for functionalization
(M'.sub.2).
[0014] Under these circumstances, one of the essential objects of
the present invention is to provide an improved process for
functionalizing silicone resins comprising siloxyl units M and Q,
by redistribution using POSs bearing functional units or units for
functionalization; this improved process needing to afford
improvements in terms of ease of use, significant increase in the
degree of functionalization of the redistributed resin and also of
the degree of conversion of the functional POS reagents, while at
the same time keeping the cost of the process as low as
possible.
[0015] Another essential objective of the invention is to provide a
new acidic catalytic system, based on triflic acid or a derivative,
which is useful or for the functionalization of silicone resins
comprising units M and Q, by redistribution, using a redistribution
reagent consisting of a POS bearing functional units or units for
functionalization, said catalytic system having properties such
that it allows an improvement in the redistribution kinetics and
also in the yield and degree of conversion of the reaction, and
does so without entailing any methodology complications or
prohibitive cost increases.
[0016] Another essential objective of the invention is to
significantly improve the homogeneous or heterogeneous catalysis of
the reactions for functionalization of resins comprising siloxyl
units M and Q by redistribution, using POSs bearing functional
units or units for functionalization. The targeted improvement
should be reflected in terms of the control, reliability and
production efficiency of the corresponding industrial
processes.
[0017] Another objective targeted through the improvement of the
catalytic system is that of improving the quality of the
functionalized MQ resins obtained, while at the same time
optimizing the safety and minimizing the ecotoxic impact of the
industrial processes under consideration.
[0018] Another essential objective of the invention is to provide a
process for the functionalization of silicone resins MQ by
redistribution, in which the yield of incorporation of the POS for
functionalization (M'.sub.2) is significantly increased relative to
those obtained by the known processes.
[0019] Another essential objective of the invention is to provide a
process for the functionalization of silicone resins MQ by
redistribution using POS for functionalization, which process
offers the possibility of controlling the content of
functionalities introduced and also the location of these functions
on the resin.
[0020] Another essential objective of the invention is to propose a
process for the functionalization of silicone resins of MQ type by
redistribution, this process being able to be applied to a wide
variety of chemical functions, so as to be able to produce a large
variety of functional MQ resins adapted to a host of applications,
from a starting material consisting of a resin core on the
periphery of which are placed selected chemical functions.
[0021] These objectives, among others, are achieved by the present
invention, which relates firstly to a process for preparing
functionalized polyorganosiloxane (POS) resins comprising units M:
(R.sub.3SiO.sub.1/2), Q: (SiO.sub.4/2) and M':
(Y.sub.aR.sub.3-aSiO.sub.1/2) and optionally D:
(R.sub.2SiO.sub.2/2) and/or D': (RYSiO.sub.2/2) and T:
(RSiO.sub.3/2) and/or T': (YSiO.sub.3/2) with, in these units:
[0022] the radicals R, which may be identical or different,
representing a C.sub.1-C.sub.10 alkyl or a C.sub.8-C.sub.12 aryl,
[0023] the radicals Y being identical or different and representing
a functional group Y, by redistribution of POS resins using POSf
bearing functional units M' and/or D' and/or T', as defined above,
in the presence of an acid catalyst, said process being
characterized: [0024] in that at least one catalyst is used of
formula (I) below:
[0024] (C.sub.mF.sub.2m+1SO.sub.2).sub.nA (I) in which: [0025] m is
an integer greater than or equal to 1; [0026] n is an integer equal
to 1 or 2 and A represents OH, NH.sub.2 or NH or CH.sub.2 with:
[0027] (i) n=1 and A=OH or [0028] (ii) n=1 and A=NH.sub.2 or NHR
with R being a radical of SO.sub.2-Z type with Z being a group
other than C.sub.mF.sub.2m+1 [0029] (iii) n=2 and A=NH; [0030] it
is necessary for the acid catalyst to be liquid under the working
conditions.
[0031] Furthermore, the choice of the catalyst may be guided by the
gas-phase acidity scale described by I. Koppel et al., J. Am. Chem.
Soc., 116 (1994) 3047. Thus, the acids used should be those whose
acidity measured in the gas phase is greater than that of sulfuric
acid, thus, in terms of .DELTA.G<302 Kcal/mol. For example,
(CF.sub.3SO.sub.2).sub.2NH .DELTA.G=292 Kcal/mol,
(C.sub.4F.sub.9SO.sub.2).sub.2NH .DELTA.G=284 Kcal/mol; [0032] and
in that this catalyst is in the presence of a nonbasic inert
filler.
[0033] The term "nonbasic" means more specifically and for example,
for the purposes of the present invention, an inert filler that is
incapable of reacting with the acid catalyst to neutralize it and
make it "catalytically" less active or even inactive.
[0034] It is thus seen that one of the essential constituent means
of the invention concerns the catalytic system formed by a
combination of triflic acid or a derivative thereof with a nonbasic
filler (or inert support).
[0035] Preferably, the nonbasic inert filler is chosen from the
group of products comprising: carbon black, an acidic or neutral
oxide, and mixtures thereof.
[0036] Even more preferably, the acidic or neutral oxide is
selected from the group comprising: Al.sub.2O.sub.3, Na.sub.2O,
TiO.sub.2, MgO, neutral or acidic zeolites, silica, and mixtures
thereof.
[0037] The use of this catalytic system makes it possible to obtain
yields for incorporation of POSs bearing functional units (for
example M'.sub.2) of greater than 50%, preferably 60% and even more
preferably 70%, to be compared with yields obtained in the
processes according to the prior art having an upper limit of
30%.
[0038] The performance qualities obtained by virtue of this
combination of triflic acid or derivative/non-basic inert filler
are entirely surprising and unexpected, not only in terms of yield
of incorporation of POSf, but also as regards the degree of
functionalization, i.e. the content of Si-function units in the
resin MQ. Specifically, this degree is greater than 2.5% by weight
and preferably greater than 3% in terms of the redistribution.
[0039] Moreover, the specifications of reduced cost, ease of use,
safety and limited or even zero ecotoxicity are largely satisfied
by the process according to the invention.
[0040] The catalytic system according to the invention is also
noteworthy in terms of kinetics.
[0041] Furthermore, the redistribution may be readily stopped by
neutralization of the acid catalyst using a base (for example
NaHCO.sub.3, Na.sub.2CO.sub.3, CaCO.sub.3) and/or by deactivation
by heat and/or by adsorption (carbon black, diatomaceous earth,
etc.).
[0042] The neutralization is all the more simple since the residual
acidity in this case is markedly lower than that obtained after
conventional redistribution catalysis. In addition, the
neutralization has the advantage that the final reaction medium is
not corrosive toward the functionalized MQ silicone resins. The
stability of these resins with respect to temperature and storage
is thereby greater.
[0043] Still regarding this stability aspect of the redistributed
resin, it may also be pointed out that, since the catalytic system
is present in trace amount in the reaction medium, it is
nondegrading with respect to the products used and/or the products
obtained after redistribution.
[0044] This process also makes it possible to control the degree of
functionalization of the MQ resin, or even the location of its
functions on the resin. Thus, starting with an MQ resin core, for
convenience, it is possible to construct around this core a
functional peripheral structure, by customizing the morphology and
hydrodynamic volume of the resin. For example, it may be envisaged
to produce on the core hair made of POS segments of (D).sub.x
type.
[0045] The functions that may be incorporated into the resin are,
for example, of Si--H, Si-Vi, Si-phenyl, Si-alkyl, Si-alkenyl,
Si-alkyne, Si-alkyl halide, Si-alkyl epoxide, Si-alkyl-polyether,
Si-carbinol, Si-alkylammonium, Si-alkylcarboxylic acid or
Si-alkylthiol type. It may thus be hoped to be able to provide
functional resins adapted to a host of applications.
[0046] In point of fact, it may be envisaged to provide a tree
produced from an industrial MQ-based resin.
[0047] Thus, the functions provided by the POSf are such that Y is
advantageously chosen from the group comprising: [0048] hydrogen
[0049] an alkenyl [0050] an alkynyl [0051] an aryl (preferably a
phenyl) [0052] an (alkyl)epoxy [0053] an ether or a polyether
[0054] a carboxylic acid [0055] an amide [0056] an amine [0057] a
halide [0058] an alcohol [0059] a thiol or any other sulfur
derivative.
[0060] In accordance with the invention, the starting MQ resins may
be either unfunctionalized or already functionalized.
[0061] As regards the unfunctionalized MQ resins, they are
commercial products, for example of formula (M.sub.xQ.sub.y).sub.z
with x between 0.5 and 1 and y between 0 and 1.
[0062] The already-functionalized MQ resins are especially those
obtained by the process in accordance with the present invention
from unfunctionalized starting MQ resins or by the synthetic
process starting with sodium silicate described in patent U.S. Pat.
No. 2,676,182.
[0063] Advantageously, the starting MQ resin is in the form of a
solution in an organic solvent, for instance xylene or toluene, or
as a solution in the PoSf oil for functionalization.
[0064] As regards the nonbasic inert filler, it is a fine powder,
i.e. the particle size of which is such that the grains are between
0.001 and 300 .mu.m.
[0065] It is, for example, Al.sub.2O.sub.3, Na.sub.2O, TiO.sub.2,
MgO, zeolite, silica, diatomaceous earth or carbon black (the
latter filler being preferred), which is in the form of powder,
granules or any other molded form. In practice, powdered carbon
black is dispersed into the PoSf oil for functionalization.
[0066] As specifically regards these POSfs bearing functional units
M' and/or D' and/or T', which are useful for the redistribution, it
will be preferred to use those of formula (IV.1) or (IV.2)
below:
##STR00001##
in which: [0067] Y and R are as defined above, [0068] a and b=0 to
2, [0069] 0.ltoreq.x.ltoreq.200 and preferably
0.ltoreq.x.ltoreq.50, [0070] 0.ltoreq.y.ltoreq.200 and preferably
0.ltoreq.y.ltoreq.50, [0071] with the condition that if x+y=0, then
a and/or b.noteq.0, [0072] 1.ltoreq.x'.ltoreq.10 and preferably
1.ltoreq.x'.ltoreq.8, [0073] 0.ltoreq.y'.ltoreq.10 and preferably
0.ltoreq.y'.ltoreq.3, [0074] 3.ltoreq.x'+y'.ltoreq.10 and
preferably x'+y'=3, 4 or 5.
[0075] The POSfs of formulae (IV.1), (IV.2) and (IV.3) correspond,
respectively, to disiloxanes, linear polyorganosiloxanes and cyclic
oligoorganosiloxanes.
[0076] These POSfs are, for example, M.sub.2, M.sub.2.sup.Vi,
MD.sub.xM, MD.sub.xD'.sub.yM, M'D.sub.xD'.sub.yM',
MD.sub.xD.sup.Vi.sub.yM, M.sup.ViD.sub.xD.sup.Vi.sub.yM.sup.Vi,
M'D.sub.xM', M.sup.ViD.sub.xM.sup.Vi.
[0077] It should be noted, as regards the acid catalyst of formula
(I)(i)(ii) or (iii) that the fluoro chain C.sub.mF.sub.2m+1 may be
extended so as to increase the acidity of the catalyst and
subsequently its efficacy.
[0078] In practice, the acid catalysts may be, for example: [0079]
(i) n=1 and A=OH [0080] (ii) n=1 and A=NH.sub.2 or NHR with R being
a radical of SO.sub.2-Z type with Z being a group other than
C.sub.mF.sub.2m+1 [0081] (iii) n=2 and A=NH.
[0082] In the preferred embodiment of the process according to the
invention, the catalyst is triflic acid of formula (I)(i) with m=1
and/or the trifluoromethanesulfonimide acid of formula (I)(iii)
with m=1.
[0083] In quantitative terms, it may be pointed out that the
concentration of acid catalyst (I) is advantageously between 1 ppm
and 2% relative to the starting resin. Moreover, the catalyst
(I)/inert support (preferably carbon black) mass ratio is
preferably between 0.1 and 10, and is preferably of the order of
1.
[0084] In accordance with the invention and according to one
preferred embodiment, the nonbasic inert filler is not linked to
the acid catalyst (I) (triflic acid or derivatives). They cohabit
separately of each other in the reaction medium.
[0085] The catalyst may be homogeneous or heterogeneous. It is
preferably homogeneous, the catalyst being in this case dissolved
in the reaction medium.
[0086] According to a first variant of heterogeneous catalysis, the
nonbasic inert filler may be an inert support onto which the
catalyst is at least partially absorbed or is intended to be at
least partially absorbed.
[0087] According to a second variant of heterogeneous catalysis,
the catalyst is at least partially absorbed onto an inert support
other than the nonbasic inert filler, this filler being moreover
present in the reaction medium. It is necessary for the acid
catalyst to be liquid under the working conditions. However, it may
be solid at 25.degree. C. and molten at the reaction
temperature.
[0088] The third variant of heterogeneous catalysis corresponds to
a combination of the first and second variants.
[0089] The process according to the invention may be defined by
other methodological characteristics, and in particular in that it
comprises the following essential steps: [0090] 1--combining the
starting POS resin, the POSf bearing functional units, the acid
catalyst (I) and the nonbasic inert filler (Al.sub.2O.sub.3,
Na.sub.2O, TiO.sub.2, MgO, silica, diatomaceous earth, zeolite or
carbon black, the latter filler being preferred), in an organic
solvent; [0091] 2--reacting preferably at a temperature .theta.r
greater than or equal to room temperature and less than or equal to
the boiling point of the solvent, and even more preferably between
50.degree. C. and 100.degree. C.; [0092] 3--optionally quenching
the reaction by adding an agent for neutralizing the acid catalyst
(I); [0093] 4--removing the inert filler (advantageously the carbon
black) from the reaction medium, preferably by filtration.
[0094] Advantageously, as has already been mentioned above, the
organic solvent, preferably xylene, toluene or white spirit, is
provided in the reaction medium by means of a solution of starting
POS resin (MQ) in said solvent. It is also possible to work with an
excess of functionalized silicone oil.
[0095] According to another advantageous embodiment, the nonbasic
inert filler, preferably the carbon black, is in the form of powder
dispersed in the PoSf bearing functional units.
[0096] The process of functionalization by redistribution according
to the invention makes it possible especially to graft Si--H and/or
Si-alkenyl (preferably vinyl) units onto MQ resins. Given that
these functions H or alkenyl are reactive functions, among others,
it may be envisaged, in accordance with the invention, to perform a
second functionalization according to a hydrosilylation mechanism,
so as to covalently attach a second functional segment onto the
already functionalized MQ resin.
[0097] This corresponds to the case in which Y represents H or
alkenyl in the functional units M' and/or D' and/or T', of the
POSf. In this variant, after the redistribution, other
functionalization radicals Y.sub.1 bearing at least one
unsaturation (preferably ethylenic) or at least one Si--H unit are
grafted onto the .ident.Si--H or .ident.Si-alkenyl units,
respectively, of the redistributed resin.
[0098] As regards the methodology, it may also be pointed out that
it is preferable, in order for the redistribution to proceed
correctly, for the reaction atmosphere to be free of moisture.
Thus, the process is advantageously performed under an atmosphere
of neutral gas, for example argon or nitrogen.
[0099] The reaction pressure is advantageously normal and the
reaction temperature may range from room temperature (for example
25.degree. C.) to a temperature of 150.degree. C. or more.
[0100] The redistribution is stopped by means of deactivating the
catalyst. Since it is an acid catalyst, in this instance triflic
acid or derivatives thereof, the deactivation may be performed
using a basic neutralizer, for instance sodium carbonate
Na.sub.2CO.sub.3 or sodium bicarbonate NaHCO.sub.3.
[0101] The neutralization is all the more necessary when the
catalysis is homogeneous catalysis, since, in such a case, in
contrast to heterogeneous catalysis, the catalyst is not removed at
the end of the reaction.
[0102] According to one variant of the process in accordance with
the invention, the redistributed and functionalized resin obtained
is subjected to at least one other
redistribution/functionalization, using POS bearing functional
units.
[0103] The invention also relates to a catalytic system that is
useful for preparing functionalized polyorganosiloxane (POS) resins
comprising units M: (R.sub.3SiO.sub.1/2), Q: (SiO.sub.4/2) and M':
(Y.sub.aR.sub.3-aSiO.sub.1/2) and optionally D:
(R.sub.2SiO.sub.2/2) and/or D': (RYSiO.sub.2/2) and/or T:
(RSiO.sub.3/2) and/or T': (YSiO.sub.3/2) with, in these units:
[0104] the radicals R being identical or different and representing
a C.sub.1-C.sub.10 alkyl or a C.sub.8-C.sub.12 aryl; [0105] the
radicals Y being identical or different and representing a
functional group Y, preferably chosen from the group comprising:
[0106] hydrogen [0107] an alkenyl [0108] an alkynyl [0109] an aryl
(preferably a phenyl) [0110] an (alkyl)epoxy [0111] an ether or a
polyether [0112] a carboxylic acid [0113] an amide [0114] an amine
[0115] a halide [0116] an alcohol [0117] a thiol or any other
sulfur derivative by redistribution of POS resins using POSs
bearing functional units M' and/or D' and/or T' as defined above,
characterized in that it comprises: [0118] A--at least one catalyst
of formula (I) below:
[0118] (C.sub.mF.sub.2m+1SO.sub.2).sub.nA (I) in which: [0119] m is
an integer greater than or equal to 1; [0120] n is an integer equal
to 1 or 2 and A represents OH, NH.sub.2 or NH with: [0121] (i) n=1
and A=OH [0122] (ii) n=1 and A=NH.sub.2 or NHR with R being a
radical of SO.sub.2-Z type with Z being a group other than
C.sub.mF.sub.2m+1 [0123] (iii) n=2 and A=NH; [0124] B--and at least
one nonbasic inert filler preferably chosen from the group of
products comprising: carbon black, an acidic or neutral oxide
(preferably selected from the group comprising: Al.sub.2O.sub.3,
Na.sub.2O, TiO.sub.2, MgO, zeolite, silica, diatomaceous earth,
carbon black, and mixtures thereof), and mixtures thereof.
[0125] This catalytic system is markedly more efficient than the
conventional catalysts for the redistribution of silicone resins MQ
using only TFOH or TFSI. In terms of kinetics, conversion and
yield, it makes it possible to obtain high-quality functionalized
MQ resins, the functionality of which is controlled and adapted to
the intended use. These performance qualities are all the more
advantageous since they are obtained without sacrificing the
imperatives of cost, safety, absence of ecotoxicity and ease of
use.
[0126] The examples that follow will make it possible to understand
more clearly the process and the catalyst according to the
invention, by highlighting all their advantages and the possible
implementation variants.
EXAMPLES
I Comparative Example
Tonsil Catalyst
[0127] 500 g of a xylene solution containing 300 g of resin
(M.sub.xQ.sub.y).sub.z (structure determined by .sup.29Si NMR:
(M.sub.0.88M'.sub.0.06D*.sub.0.05Q.sub.1*).sub.z-M/Q=0.9) are
introduced into a 1 liter reactor under nitrogen. 30 g of M'.sub.2
(1.49 mol SiH/kg of resin) and 2.7 g of Tonsil are added. The
mixture is brought to 70.degree. C. and heated at this temperature
for 7 hours. After cooling to room temperature, the reaction mass
is filtered through cardboard and then through a 0.45 .mu.m PTFE
filter to remove the Tonsil. During the test, several samples are
taken and make it possible to monitor the amount of SiH bound to
the resin and also the nature and relative proportions of the light
fractions in the reaction medium as a function of the reaction
time.
TABLE-US-00001 TABLE 1 Reaction time 0 h 1 h 3 h 6 h 7 h Amount of
SiH on the resin 0% 0.8% 1.2% 1.47% 1.39% (quantification by IR)
Conversion of M'.sub.2 0% 52% 74% 78% 82% (quantification by
GC)
Final structure of the resin (.sup.29Si NMR):
(M.sub.0.82M'.sub.0.08D*.sub.0.05Q*).sub.z Final yield of
incorporation of SiH: 32%.
II Comparative Example
H.sub.2SO.sub.4+Black Catalyst
[0128] The operating conditions are the same as those described in
example I.
Materials added: 491.26 g of xylene solution, i.e. [0129] 304.6 g
of resin [0130] 30.1 g of M'.sub.2, i.e. 1.44 mol/kg of resin
[0131] 0.44 g of H.sub.2SO.sub.4 [0132] 0.60 g of Black 4S Reaction
time: 7 hours Monitoring of the reaction:
TABLE-US-00002 [0132] TABLE 2 Reaction time 0 h 1 h 3 h 6 h 7 h
Amount of SiH on the 0% 0.38% 0.73% 0.89% 1.00% resin
(quantification by IR) Conversion of M'.sub.2 (%) 0% 33% 58.5% 68%
70% (quantification by GC)
Final structure of the resin (.sup.29Si NMR):
M.sub.0.79M'.sub.0.03D*.sub.0.06Q* Final yield of incorporation of
SiH: 25%.
III Example
CF.sub.3SO.sub.3H Catalyst
[0133] The operating conditions are the same as those described in
example I.
Materials added: 500.0 g of xylene solution, i.e. [0134] 300 g of
resin [0135] 30.0 g of M'.sub.2, i.e. 1.47 mol/kg [0136] 1.31 g of
CF.sub.3SO.sub.3H Reaction time: 7 hours Monitoring of the
reaction:
TABLE-US-00003 [0136] TABLE 3 Reaction time 0 h 1 h 3 h 6 h 7 h
Amount of SiH on the 0% 2.79% 3.17% 3.08% 3.28% resin
(quantification 3.37% by KOH assay) (IR) Conversion of M'.sub.2 (%)
0% 94.5% 97% 97% 97% (quantification by GC)
Final structure of the resin (.sup.29Si NMR):
(M.sub.0.72M'.sub.0.11D*.sub.0.04Q*).sub.z Final yield of
incorporation of SiH: 75%.
IV Example
CF.sub.3SO.sub.3H+Black 4S Catalyst
[0137] The operating conditions are the same as those described in
example I.
Materials added: 490.8 g of xylene solution, i.e. [0138] 304.3 g of
resin [0139] 30.1 g of M'.sub.2, i.e. 1.49 mol/kg [0140] 1.28 g of
CF.sub.3SO.sub.3H [0141] 1.83 g of Black 4S Reaction time: 7 hours
Monitoring of the reaction:
TABLE-US-00004 [0141] TABLE 4 Reaction time 0 h 1 h 3 h 6 h 7 h
Amount of SiH on the 0% 1.79% 3.05% 3.14% 3.18% resin
(quantification 3.05% by KOH assay) (IR) Conversion of M'.sub.2 (%)
0% 81% 96% 97% 97% (quantification by GC)
Final structure of the resin (.sup.29Si NMR)
(M.sub.0.72M'.sub.0.14D*.sub.0.05Q*).sub.z Final yield of
incorporation of SiH: 73%.
V Comparative Test
Tonsil Catalyst
[0142] 500 g of a xylene solution containing 300 g of resin
(M.sub.xQ.sub.y).sub.z (NMR analyses: M.sub.0.9D.sub.0.02Q.sub.1
with M/Q=0.9 (molar)) are introduced into a 3 liter reactor under
nitrogen. This solution is brought to 70.degree. C. and 30 g (1.49
mol SiH/kg of resin) of M'.sub.2 and 2 g of Tonsil are added. The
mixture is left to react for 7 hours at 70.degree. C. The reaction
mass is cooled and filtered through cardboard+0.45 .mu.m PTFE
filter to remove the Tonsil. During this test, a certain number of
samples are taken, which make it possible to monitor the amount of
SiH units as a function of time: T=0: 0%, T=1 h: 0.8%, T=3 h: 1.2%,
T=7 h: 1.47%, or 1.39% (IR), i.e. 0.48 mol SiH/kg of resin.
[0143] The yield for incorporation of the SiH units is 32%. The NMR
analyses show that the structure of the final resin is:
(M.sub.0.8M'.sub.0.07D*.sub.0.04Q.sub.1).sub.z.
VI H.sub.2SO.sub.4
Black Catalysis Test
[0144] Same operating conditions as for example I: [0145] 500 g of
xylene solution containing 300 g of resin (M.sub.xQ.sub.y).sub.z
[0146] 30 g of M'.sub.2, i.e. 1.49 mol of SiH/kg of resin [0147]
1.09 g of H.sub.2SO.sub.4 [0148] 1.39 g of Black 2S reaction time:
8 hoursSiH IR assay: 1.24%, i.e. 0.43 mol SiH/kg of resin yield of
SiH incorporation: 29% final resin structure:
(M.sub.0.8M'.sub.0.05D*.sub.0.08Q.sub.1).sub.z
VII CF.sub.3SO.sub.3H Catalysis Test
[0149] Same operating conditions as for example I: [0150] 642.1 g
of xylene solution containing 400 g of resin (M.sub.xQ.sub.y).sub.z
[0151] 47.21 g of M.sup.Vi.sub.2, i.e. 1.27 mol of Si-vinyl/kg of
resin [0152] 2.45 g of carbon black [0153] 1.71 g of
CF.sub.3SO.sub.3H reaction time: 8 hours 10 minutesIR assay: 1.1
mol Si-vinyl/kg of resin yield of SiH incorporation: 87% final
resin structure:
(M.sub.0.76M.sup.Vi.sub.0.11D*.sub.0.03Q.sub.1).sub.z.
* * * * *