ROOM TEMPERATURE VULCANISABLE ORGANOPOLYSILOXANE COMPOUND TO GIVE AN ELASTOMER AND NOVEL ORGANOPOLYSILOXANE POLYCONDENSATION CATALYSTS

• US 20110046304A1
• Filed: 12/18/2008
• Published: 02/24/2011
• Est. Priority Date: 12/20/2007
• Status: Active Grant

• Current Assignee: Bluestar Silicones France SAS
• Original Assignee: Bluestar Silicones France SAS
• Inventors: Maliverney, Christian
• Granted Patent: US 8,835,590 B2
• Time in Patent Office: Days
• US Class Current: 524/789
• CPC Class Codes: C08G 77/08 characterised by the catalysts used
• CPC Class Codes: C08G 77/14 containing silicon bound to oxygen-containing groups C08G77/045 takes precedence
• CPC Class Codes: C08G 77/18 to alkoxy or aryloxy groups
• CPC Class Codes: C08L 83/04 Polysiloxanes

Abstract

The present invention relates to an organopolysiloxane composition that can be vulcanized at room temperature into an elastomer that is crosslinked by polycondensation and that does not contain alkyltin-based catalysts and also to novel organopolysiloxane polycondensation catalysts.

Claims

1. An organopolysiloxane composition, comprising, on the one hand, a silicone base B capable of curing via polycondensation reaction into a silicone elastomer and, on the other hand, a catalytically effective amount of at least one polycondensation catalyst which is a metal complex or salt A of formula (1):

[Zn(L¹)(L²)] 

 

(1)

in which;

the symbols L¹ and L² are identical or different and represent a ligand which is a β

-dicarbonylato anion or the enolate anion of a β

-dicarbonyl-containing compound of formula (2) or an acetylacetato anion derived from a β

-keto ester of formula (2) below;

R¹COCHR²COR³ 

 

(2)

in which;

R¹represents a substituted or unsubstituted, linear or branched C₁-C₃₀ hydrocarbon-based radical;

R² is a hydrogen or a substituted or unsubstituted, linear or branched C₁-C₃₀ hydrocarbon-based radical, preferably a hydrogen atom or an alkyl radical having at most 4 carbon atoms;

R³ represents a substituted or unsubstituted, linear, cyclic or branched C₁-C₃₀ hydrocarbon-based radical, a substituted or unsubstituted aromatic, or an —

OR⁴ radical with R⁴ representing a substituted or unsubstituted, linear, cyclic or branched C₁-C₃₀ hydrocarbon-based radical, where

R¹ and R² may be joined together to form a ring;

R² and R³ may be joined together to form a ring; and

with the supplementary condition that the metal complex or salt A of formula (1) is not the zinc diacetylacetonate or Zn(acac)₂ compound.

2. The organopolysiloxane composition as claimed in claim 1, comprising, characterized in that it comprises, on the one hand, a silicone base B capable of curing via polycondensation reaction into a silicone elastomer and, on the other hand, a catalytically effective amount of at least one polycondensation catalyst which is a metal complex or salt A chosen from the group constituted by the complexes (3) to (6) below:

(3);

Zn(DPM)₂ or [Zn(t-Bu-acac)₂] where DPM=(t-Bu-acac)=the 2,2,6,6-tetramethyl-3,5-heptanedionato anion or the enolate anion of 2,2,6,6-tetramethyl-3,5-heptanedione;

(4);

[Zn(EAA)₂] where EAA=the ethyl acetoacetato anion or the enolate anion of ethyl acetoacetate;

(5);

[Zn(iPr-AA)₂] where iPr-AA=the isopropyl acetoacetato anion or the enolate anion of isopropyl acetoacetate; and

3. The organopolysiloxane composition as claimed in claim 1, wherein the β

-dicarbonylato ligands L¹ and L² are β

-diketonato anions derived from a 3-diketone chosen from the group constituted by the following β

-diketones;

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 (t-Bu-acac);

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;

stearoyl benzoyl methane;

octanoyl benzoyl methane;

4-t-butyl-4′

-methoxydibenzoylmethane;

4,4′

-dimethoxydibenzoylmethane and 4,4′

-di-tert-butyldibenzoylmethane.

4. The organopolysiloxane composition as claimed in claim 1, wherein the β

-dicarbonylato ligands L¹ and L² are β

-ketoesterato anions chosen from the group constituted by the anions derived from the following compounds;

methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, isopentyl, n-hexyl, n-octyl, 1-methylheptyl, n-nonyl, n-decyl and n-dodecyl esters of acetylacetic acid.

5. The composition as claimed in claim 1, further comprising a catalytically effective amount of at least one polycondensation catalyst which is a metal complex or salt A and a silicone base B comprising:

at least one polyorganosiloxane oil C capable of crosslinking via polycondensation into an elastomer;

optionally at least one crosslinking agent D;

optionally at least one adhesion promoter E; and

optionally at least one siliceous, organic and/or non-siliceous mineral filler F.

6. A two-component system that is a precursor of the organopolysiloxane composition as claimed in claim 5 that can be cured to a silicone elastomer via a polycondensation reaction, wherein said system is in two separate parts P1 and P2 intended to be mixed in order to form said composition, and wherein one of said parts comprises the metal complex or salt A as a catalyst for the polycondensation reaction of an organopolysiloxane and the crosslinking agent D, whilst the other part is free of said catalyst and said crosslinking agent and comprises:

per 100 parts by weight of the polyorganosiloxane oil(s) C capable of crosslinking via polycondensation into an elastomer;

from 0.001 to 10 part(s) by weight of water.

7. A single-component polyorganosiloxane composition that is stable during storage in the absence of moisture and that crosslinks, in the presence of water, into an elastomer, said composition comprising:

at least one crosslinkable linear polyorganopolysiloxane that has functionalized ends of alkoxy, oxime, acyl and/or enoxy type,

at least one filler; and

a catalyst of the polycondensation reaction which is the metal complex or salt A claimed in claim 1.

8. An elastomer obtained by crosslinking and curing the composition as claimed in claim 1.

9. A catalyst for the polycondensation reaction of an organopolysiloxane comprising a metal complex or salt A as claimed in claim 1.

10. A compound of the following formulae:

(5);

[Zn(iPr-AA)₂] where iPr-AA=the isopropyl acetoacetato anion or the enolate anion of isopropyl acetoacetate; and

/or