Siloxane crosslinking processes employing sulfur compounds and platinum catalysts

• US 10,457,795 B2
• Filed: 01/13/2016
• Issued: 10/29/2019
• Est. Priority Date: 07/09/2015
• Status: Active Grant

• Current Assignee: Momentive Performance Materials Incorporated (Momentive Performance Materials Holdings LLC)
• Original Assignee: Momentive Performance Materials Incorporated (Momentive Performance Materials Holdings LLC)
• Inventors: Boyer, Julie L., Roy, Aroop Kumar
• Primary Examiner(s): Moore, Margaret G
• Application Number:
  US15/742,564
• Publication Number:
  US 20180194931A1
• Time in Patent Office: 1,385 Days
• CPC Class Codes: B01J 31/28 of the platinum group metals, iron group metals or copper
• CPC Class Codes: C08G 77/12 containing silicon bound to hydrogen C08G77/045 takes precedence
• CPC Class Codes: C08G 77/20 containing silicon bound to unsaturated aliphatic groups C08G77/045 takes precedence
• CPC Class Codes: C08J 3/242 Applying crosslinking or accelerating agent onto compounding ingredients such as fillers, reinforcements
• CPC Class Codes: C08K 5/05 Alcohols; Metal alcoholates
• CPC Class Codes: C08K 5/37 Thiols
• CPC Class Codes: C08K 5/372 Sulfides , e.g. R-(S)x-R'
• CPC Class Codes: C08K 5/56 Organo-metallic compounds, i.e. organic compounds containing a metal-to-carbon bond
• CPC Class Codes: C08L 83/00 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 Class Codes: C08L 83/04 Polysiloxanes

Abstract

Provided is a composition and process for producing a crosslinked product. The composition comprises a mixture constituting (a) an alkenyl silicone, (b) a hydrogen siloxane, (c) a cure inhibitor and (d) a hydrosilylation catalyst, optionally in the presence of a solvent, and (e) sulfur compounds in order to produce the crosslinked product, and the process comprises reacting such a composition to form a crosslinked product.

Claims

1. A process for producing a crosslinked product comprising reacting a mixture constituting (a) an alkenyl silicone, (b) a hydrogen siloxane, (c) a cure inhibitor chosen from an ethylenically unsaturated amide, an aromatically unsaturated amide, an acetylenic compound, an ethylenically unsaturated isocyanate, an olefinic siloxane, an unsaturated hydrocarbon diester, an unsaturated hydrocarbon mono-ester of an unsaturated acid, a conjugated or isolated ene-yne, a hydroperoxide, a ketones, a sulfoxide, an amine, a phosphine, a phosphite, a nitrite, a diaziridine, or a combination of two or more thereof, and (d) a hydrosilylation catalyst, optionally in the presence of a solvent, and (e) a sulfur compound in order to produce the crosslinked product, the sulfur compound (e) being a compound of the formula:

R¹—

S—

R²

where (i) R¹ and R² are independently chosen from a H a C1-C20 hydroxyalkyl, a C1-C20 carboxylic acid, or a combination thereof, or (ii) R¹ is chosen from a C1-C20 alkyl, and R² is chosen from a C1-C20 hydroxyalkyl, with the proviso that Formula I is not H₂S.

2. The process of claim 1, wherein the hydrosilylation catalyst (d) comprises a metal, and the ratio of total moles of the sulfur compound (e) to moles of the metal in catalyst (d) is from about 1:

1 to about 100;

1.

3. The process of claim 1, wherein the hydrosilylation catalyst (d) comprises a metal, and the ratio of total moles of the sulfur compound (e) to moles of the metal in catalyst (d) is from about 1:

1 to about 10;

1.

4. The process of claim 1, comprising the inhibitor (c) in an amount of from about 0.001 to about 10% by weight of the mixture.

5. The process of claim 1 comprising the inhibitor (c) in an amount of from about 0.01 to about 0.1% by weight of the mixture.

6. The process of claim 1, wherein the hydrosilylation catalyst is a platinum-based catalyst, and the platinum is present in an amount of from about 100 parts per billion to about 100 parts per million.

7. The process of claim 6, wherein the platinum is present in an amount of from about 1 ppm to about 50 ppm.

8. The process of claim 1, wherein the curable alkenyl silicone is of the formula:

M^vi_aT_bD_cM_dQ_e

wherein M^vi_a=R³₂R⁴SiO_1/2;

T_b=R⁵SiO_3/2 where R⁵ is chosen from R³ or R⁴;

D_c=R³R⁵SiO_2/2 where R⁵ is chosen from R³ or R⁴;

M_d=R³₃SiO_1/2; and

Q_e=SiO_4/2;

R³ is independently selected from a monovalent hydrocarbon radical having one to forty carbon, optionally containing at least one heteroatom; and

R⁴ is selected from a terminal olefinic monovalent hydrocarbon radical having two to forty carbon atoms, optionally containing at least one heteroatom, where the composition of the alkenyl silicone comprises at least two unsaturated groups reactive to hydrosilylation per chain;

a≥

0, b≥

0, d≥

0, e≥

0;

values for c in particular are determined by the desired properties and attributes of the cross-linked material so that the sum a+b+c+d+e is in the range 50-20,000.

9. The process of claim 1, wherein the hydrogen siloxane is chosen from a compound of the formula M_a′

M^H_b′

D_c′

D^H_d′

T_e′

T^H_f′

Q_g, where the subscripts a′

, b′

, c′

, d′

, e′

, f, and g are such that the molar mass of the siloxane-type reactant is between 100 and 100,000 Dalton;

M is a monofunctional group of formula R⁶₃SiO_1/2, D is a difunctional group of formula R¹⁵₂SiO_2/2, T is a trifunctional group of formula R⁷SiO_3/2, and Q is a tetrafunctional group of formula SiO_4/2, M^H is HR⁸₂SiO_1/2, T^H is HSiO_3/2, and D^H is R¹⁰HSiO_2/2, where each occurrence of R^6-1°

is independently chosen from a C1-C40 alkyl, a C1-C40 substituted alkyl, a C6-C14 aryl or substituted aryl, wherein R^6-10 optionally contains at least one heteroatom.

10. The process of claim 1, wherein the reaction is completed in about 10 seconds or less.

11. The process of claim 1, wherein the process is conducted by heating at a temperature of from about 0 to about 300°

F.

12. The process of claim 1, wherein components (a)-(d) are provided in a single composition.

13. The process of claim 1, wherein components (a) and (e) are provided in a first part (i) optionally comprising component (c);

component (b) is provided in a second part (ii); and

component (d) is provided in a third part (iii), and the process comprises mixing parts (i), (ii), and (iii) to conduct the reaction.

14. The process of claim 1, wherein component (a) and optionally component (c) is provided in a first part;

component (b) is provided in a second part (ii); and

components (d) and (e) are provided in a third part (iii).

24. A cured material prepared from the process of claim 1.

25. The cured material of claim 24, wherein the cured material is a coating.

26. A substrate having a surface thereof at least partially coated with the coating of claim 25.

27. The substrate of claim 26, wherein the coating is a release coating.

28. A cured material formed from the composition of claim 14.

15. A composition for producing a crosslinked product, the composition comprising (a) an alkenyl silicone, (b) a hydrogen siloxane, (c) a cure inhibitor chosen from an ethylenically unsaturated amide, an aromatically unsaturated amide, an acetylenic compound, an ethylenically unsaturated isocyanate, an olefinic siloxane, an unsaturated hydrocarbon diester, an unsaturated hydrocarbon mono-ester of an unsaturated add, a conjugated or isolated ene-yne, a hydroperoxide, a ketones, a sulfoxide, an amine, a phosphine, a phosphite, a nitrite, a diaziridine, or a combination of two or more thereof, and (d) a hydrosilylation catalyst, optionally in the presence of a solvent, and (e) a sulfur compound in order to produce the crosslinked product, the sulfur compound (e) being a compound of the formula:

R¹—

S—

R²

where (i) R¹ and R² are independently chosen from a H a C1-C20 hydroxyalkyl, a C1-C20 carboxylic acid, or a combination thereof, or (ii) R¹ is chosen from a C1-C20 alkyl, and R² is chosen from a C1-C20 hydroxyalkyl, with the proviso that Formula I is not H₂S.

16. The composition of claim 15, wherein the hydrosilylation catalyst (d) comprises a metal, and the ratio of total moles of the sulfur compound (e) to moles of the metal in catalyst (d) is from about 1:

1 to about 100;

1.

17. The composition of claim 15, wherein the hydrosilylation catalyst (d) comprises a metal, and the ratio of total moles of the sulfur compound (e) to moles of the metal in catalyst (d) is from about 1:

1 to about 10;

1.

18. The composition of claim 15, comprising the inhibitor (c) in an amount of from about 0.001 to about 10% by weight of the mixture.

19. The composition of claim 15 comprising the inhibitor (c) in an amount of from about 0.01 to about 0.1% by weight of the mixture.

20. The composition of claim 15, wherein the hydrosilylation catalyst is a platinum-based catalyst, and the platinum is present in an amount of from about 100 parts per billion to about 100 parts per million.

21. The composition of claim 20, wherein the platinum is present in an amount of from about 1 ppm to about 50 ppm.

22. The composition of claim 15, wherein the curable alkenyl silicone is of the formula:

M^vi_aT_bD_cM_dQ_e

wherein M^vi_a=R³₂R⁴SiO_1/2;

T_b=R⁵SiO_3/2 where R⁵ is chosen from R³ or R⁴;

D_c=R³R⁵SiO_2/2 where R⁵ is chosen from R³ or R⁴;

M_d=R³₃SiO_1/2; and

Q_e=SiO_4/2;

R³ is independently selected from a monovalent hydrocarbon radical having one to forty carbon, optionally containing at least one heteroatom; and

R⁴ is selected from a terminal olefinic monovalent hydrocarbon radical having two to forty carbon atoms, optionally containing at least one heteroatom, where the composition of the alkenyl silicone comprises at least two unsaturated groups reactive to hydrosilylation per chain;

a≥

0, b≥

0, d≥

0, e≥

0;

values for c in particular are determined by the desired properties and attributes of the cross-linked material so that the sum a+b+c+d+e is in the range 50-20,000.

23. The composition of claim 15, wherein the hydrogen siloxane is chosen from a compound of the formula M_a′

M^H_b′

D_c′

D^H_d′

T_e′

T^H_fQ_g, where the subscripts a′

, b′

, c′

, d′

, e′

, f, and g are such that the molar mass of the siloxane-type reactant is between 100 and 100,000 Dalton;

M is a monofunctional group of formula R⁶₃SiO_1/2, D is a difunctional group of formula R¹⁵₂SiO_2/2, T is a trifunctional group of formula R⁷SiO_3/2, and Q is a tetrafunctional group of formula SiO_4/2, M^H is HR⁸₂SiO_1/2, T^H is HSiO_3/2, and D^H is R¹⁰HSiO_2/2, where each occurrence of R^6-10 is independently chosen from a C1-C40 alkyl, a C1-C40 substituted alkyl, a C6-C14 aryl or substituted aryl, wherein R^6-10 optionally contains at least one heteroatom.