Novel silicone composition crosslinking catalysts

Patent metadata

Field	Value
Publication number	US-2018016398-A1
Application number	US-201515523503-A
Country	US
Kind code	A1
Filing date	Nov 6, 2015
Priority date	Nov 7, 2014
Publication date	Jan 18, 2018
Grant date	—

Abstract

The invention relates to a crosslinkable composition X, comprising: at least one organopolysiloxane compound A comprising, per molecule, at least two C2-C6 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: [Co(L1)2] in which: the symbol Co represents cobalt at degree of oxidation II; the symbols L1, which may be identical or different, represent a ligand which is a β-dicarbonylato anion or the enolate anion of a β-dicarbonylated compound; optionally at least one adhesion promoter D; and optionally at least one charge E. The invention also relates to the use of the previously described catalyst C as silicone composition crosslinking catalyst, to a silicone composition crosslinking method, characterized in that it consists in heating the composition X to a temperature of between 70 and 200° C., and to the resulting crosslinked silicone material Y.

First claim

1 - A crosslinkable composition X comprising:
at least one organopolysiloxane compound A comprising, per molecule, at least two C 2 -C 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:
[Co(L 1 ) 2 ]
in which:
the symbol Co represents cobalt in oxidation state II,
the symbols L 1 , which may be identical or different, represent a ligand which is a β-dicarbonylato anion or the enolate anion of a β-dicarbonyl compound,
optionally at least one adhesion promoter D and optionally at least one filler E.

2 - The composition X as claimed in claim 1 , wherein the catalyst C is present in a content ranging from 0.001 to 10 mol % of cobalt per number of moles of C 2 -C 6 alkenyl radicals bonded to silicon atoms in the organopolysiloxane compound A, optionally from 0.01 to 7%, and more optionally from 0.1 to 5%.

3 - The composition X as claimed in claim 1 , wherein said composition is free of catalyst based on platinum, palladium, ruthenium or rhodium.

4 - The composition X as claimed in claim 1 , wherein the ligand L 1 is an anion derived from a compound of formula (1):
R 1 COCHR 2 COR 3   (1)

in which:
R 1 and R 3 , which may be identical or different, represent a linear, cyclic or branched C 1 -C 30 hydrocarbon-based radical, an aryl containing between 6 and 12 carbon atoms or a radical —OR 4 with R 4 representing a linear, cyclic or branched C 1 -C 30 hydrocarbon-based radical,
R 2 is a hydrogen atom or a hydrocarbon-based radical, optionally an alkyl radical comprising from 1 to 4 carbon atoms; with
R 1 and R 2 may be joined together to form a C 5 -C 6 ring, and
R 2 and R 4 may be joined together to form a C 5 -C 6 ring.

5 - The composition X as claimed in claim 1 , in which the compound of formula (1) is chosen from the group formed by the following β-diketones: 2,4-pentanedione (acac); 2,4-hexanedione; 2,4-heptanedione; 3,5-heptanedione; 3-ethyl-2,4-pentanedione; 5-methyl-2,4-hexanedione; 2,4-octanedione; 3,5-octanedione; 5,5-dimethyl-2,4-hexanedione; 6-methyl-2,4-heptanedione; 2,2-dimethyl-3,5-nonanedione; 2,6-dimethyl-3,5-heptanedione; 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; dibenzoylmethane; 3-methyl-2,4-pentadione; 3-acetyl-2-pentanone; 3-acetyl-2-hexanone; 3-acetyl-2-heptanone; 3-acetyl-5-methyl-2-hexanone; benzoylstearoylmethane; benzoylpalmitoylmethane; octanoylbenzoylmethane; 4-t-butyl-4′-methoxydibenzoylmethane; 4,4′-dimethoxydibenzoylmethane and 4,4′-di-tert-butyldibenzoylmethane, and optionally from the β-diketones 2,4-pentanedione (acac) and 2,2,6,6-tetramethyl-3,5-heptanedione (TMHD).

6 - The composition X as claimed in claim 1 , in which the catalyst C is chosen from the complexes [Co(acac) 2 ], [Co(TMHD) 2 ], [Co(keto ester) 2 ] and [Co(Rhodiastab 50) 2 ], in which “acac” means the anion derived from the compound 2,4-pentanedione, “TMHD” means the anion derived from the compound 2,2,6,6-tetramethyl-3,5-heptanedione, “keto ester” means the anion derived from a methyl ester of acetylacetic acid and “Rhodiastab 50” means a mixture of anions derived from the compound benzoylstearoylmethane, and anions derived from the compound benzoylpalmitoylmethane.

7 - The composition X as claimed in claim 1 , wherein the organopolysiloxane A comprises:
(i) at least two siloxyl units (A.1), which may be identical or different, having the following formula:

W
a



Z
b



SiO

4
-

(

a
+
b

)

2

(

A

.1

)

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 linear or branched C 2 -C 6 alkenyl group,
and the symbols Z, which may be identical or different, represent a monovalent hydrocarbon-based group containing from 1 to 30 carbon atoms, optionally chosen from the group formed by alkyl groups containing from 1 to 8 carbon atoms and aryl groups containing between 6 and 12 carbon atoms, and even more optionally chosen from the group formed by methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl and phenyl radicals,

(ii) and optionally at least one siloxyl unit having the following formula:

Z
a
1



SiO

4
-
a

2

(

A

.2

)

in which:
a=0, 1, 2 or 3,
the symbols Z 1 , which may be identical or different, represent a monovalent hydrocarbon-based group containing from 1 to 30 carbon atoms, optionally chosen from the group formed by alkyl groups containing from 1 to 8 carbon atoms inclusive and aryl groups containing between 6 and 12 carbon atoms, and even optionally chosen from the group formed by methyl, ethyl, propyl, 3,3,3-trifluoropropyl, xylyl, tolyl and phenyl radicals.

8 - The composition X as claimed in claim 1 , in which the organohydrogenopolysiloxane compound B comprises at least three hydrogen atoms per molecule directly bonded to an identical or different silicon atom.

9 - The composition X as claimed in claim 1 , in which the organohydrogenopolysiloxane compound B is an organopolysiloxane comprising:
(i) at least two siloxyl units and optionally at least three siloxyl units having the following formula:

H
d



Z
e
3



Assignees

• Bluestar Silicones France
• Univ Claude Bernard Lyon
• Centre Nat Rech Scient

Inventors

• Monteil Vincent
• Raynaud Jean
• Crozet Delphine
• Bousquié Magali
• Marrot Sébastien

Classifications

• C08G77/20

  containing silicon bound to unsaturated aliphatic groups · CPC title

• C08L83/00

  Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers · CPC title

• C08K5/0091

  Complexes with metal-heteroatom-bonds · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08L2312/00

  Crosslinking · CPC title