Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From silicon reactant having at least one...
Reexamination Certificate
2003-07-23
2004-11-09
Moore, Margaret G. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From silicon reactant having at least one...
Reexamination Certificate
active
06815518
ABSTRACT:
The present invention relates to a novel method for preparing functionalized silicone oils with controlled viscosity, containing at least one hydrocarbon ring in which is included an oxygen atom. In particular, the present invention relates to a method of hydrosilylation between polyorganohydrosiloxanes and unsaturated synthons containing at least one hydrocarbon ring in which is included an oxygen atom.
Reactions between polyorganohydrosiloxanes and olefins or acetylenic hydrocarbons are very well known. The polyorganohydrosiloxanes have, for example, the formulae:
Me
3
SiO—(MeHSiO)
n
—(Me
2
SiO)
m
—SiMe
3
in which n and m are integers or fractions such that 1≦n≦1000 and 0<m≦1000;
Me
2
HSiO—(MeHSiO)
o
—(Me
2
SiO)
p
—SiHMe
2
in which o and p are integers or fractions such that 0<o≦1000 and 0<p≦1000.
Many synthons can functionalize polyorganohydrosiloxanes; for example, alkenes, styrenes, allyl alcohols, allyloxy ethers or allylamines are used as synthons.
These reactions are very commonly used for the synthesis of functionalized silicone oils, and the oils obtained as applications in very diverse fields such as anti-adhesion and lubrication.
In particular, functionalized oils can be prepared with 1,2-epoxy-4-vinylcyclohexane synthons. By way of application, these functionalized silicone oils are then thermally crosslinked in the presence of an acid catalyst such as hydrochloric acid or sulfuric acid, or photochemically crosslinked in the presence, for example, of a cationic photoinitiator for the preparation of anti-adhesive films for paper and/or plastics.
A very large number of catalytic compositions is used in hydrosilylation reactions. The catalytic compositions most widely known contain metals such as platinum, rhodium, cobalt or palladium. Specific examples of such catalytic compositions are platinum halides and rhodium halides, for example H
2
PtCl
6
, PtCl
2
, (RhCl
3
.xH
2
O), complexes of platinum with siloxanes containing unsaturated groups, complexes of platinum with olefins and cationic complexes of platinum with nitrites as ligands.
Generally, the catalytic compositions used in the hydrosilylation reaction are homogeneous catalytic compositions, i.e. said compositions are dissolved in the reaction medium. One of the compositions most widely used is the catalytic Karstedt composition described in particular in U.S. Pat. No. 3,775,452; this Karstedt composition consists of platinum complexes in which the absolute and real degree of oxidation is zero (0), and which are of formula:
However, during the hydrosilylation reaction according to the methods of the prior art, isomerization reactions of the unsaturated synthons are observed to varying degrees, which makes it necessary to work with a molar excess of synthons relative to the polyorganohydrosiloxane in the reaction medium. This excess in the proportion of synthon causes additional expense for the industrial implementation of the method. It would therefore be desirable to reduce the required proportion of synthon, which would result in a not insignificant saving in terms of the method.
In addition, the hydrosilylation processes of the prior art are relatively unsuitable, or not at all suitable, for hydrosilylation reactions between polyorganohydrosiloxanes and synthons containing a ring in which is included an oxygen atom (epoxide, etc.). The latter, during the hydrosilylation reaction and/or the devolatilization step, have a tendency to open up and to cause uncontrolled reactions of polymerization and of crosslinking (formation of gum and/or resin) of the functionalized oils, which are initiated by the presence of the usual catalytic compositions such as the homogeneous catalytic compositions which also catalyze the polymerization of rings which include an oxygen atom.
In addition, the functionalized silicone oils obtained from usual methods are generally colored, with the order of 120 to 300 hazen, which as a result limits the domains which can be envisioned for their use, in particular in the domain of transparent and anti-adhesive films for paper or for transparent films (for example of the polyester type). This coloration is generally due to the presence in the functionalized oils of metal aggregates or of colloids of nanometric size, derived from the usual catalytic compositions. In these cases, the functionalized silicone oils require additional sets of filtration and purification in order to be usable after crosslinking in the domain of transparent films; these additional steps make industrial implementation expensive and therefore economically relatively nonviable.
The Applicant has developed a novel method for preparing functionalized silicone oils by hydrosilylation, which makes it possible to significantly reduce the isomerization reactions of the unsaturated synthon and to very substantially reduce the opening of the ring including an oxygen atom, present on the unsaturated synthon.
The method used makes it possible to obtain functionalized silicone oils which are less colored than those obtained using a method with a catalyst of the Karstedt type, which makes it possible to limit or eliminate the purification steps. Depending on the case, the oils obtained are transparent and/or translucent and can therefore be used directly in applications requiring these qualities.
In particular, the silicone oils obtained using the method of the invention can be used after crosslinking, in the domain of inks, the domain of varnishes and also in the domain of coatings, in particular films, transparent and/or anti-adhesive, through applications on supports of very varied nature; for example papers, glasses, plastics and/or metals.
According to the hydrosilylation method of the present invention, the polyorganohydrosiloxane is reacted with synthons, which may be different or identical, containing a hydrocarbon ring in which is included at least one oxygen atom. This reaction is carried out in the presence of a catalytic metal complex of formula I:
in which:
M represents a metal in the 0 oxidation state chosen from the metals of group 8 of the Periodic Table as published in Handbook of Chemistry and Physics, 65th edition, 1984-1985;
X represents O, NR
a
and/or CR
f
R
g
;
Y
1
and Y
2
, which may be identical or different, represent CR
b
R
c
and/or SiR
d
R
e
;
R
1
, R
2
, R
5
and R
6
, which may be identical or different, are chosen from a hydrogen atom, an alkyl group and an aryl group optionally substituted with alkyl;
R
3
, R
4
, R
a
, R
b
, R
c
, which may be identical or different, are chosen from a hydrogen atom; an alkyl group; an acyl group; an aryl group optionally substituted with an alkyl; a cycloalkyl group optionally substituted with an alkyl; and an arylalkyl group in which the aryl component is optionally substituted with an alkyl component;
R
d
and R, which may be identical or different, are chosen from an alkenyl; an alkynyl; an alkyl; an alkoxy; an acyl; an aryl optionally substituted with an alkyl; a cycloalkyl optionally substituted with an alkyl; and an arylalkyl in which the aryl component is optionally substituted with an alkyl; or else
when Y
1
and Y
2
, which may be identical or different, represent SiR
d
R
e
, two groups R
d
linked to two different silicon atoms together form:
a chain of formula:
which n is an integer from 1 to 3; X is as defined above; R and R′, which may be identical or different, take any one of the meanings given above for R
e
, it being understood that, when n is 2 or 3, a single silicon atom of said chain can be substituted with one or two alkenyl or alkynyl groups;
a saturated hydrocarbon chain, the two groups R
d
together with said silicon atoms and X forming a 6- to 10-membered ring; or else
when Y
1
and Y
2
, which may be identical or different, represent CR
b
R
c
, two groups R
b
linked to different carbon atoms together form a saturated hydrocarbon chain, the two groups R
b
together with the carbon atoms which bear them and X forming a 6- to 10-membered ring;
R
f
and R
g
represent, independently of one another,
Moore Margaret G.
Rhodia Chimie
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