Polyorganosiloxane compositions containing a 2-substituted-1-alkynyl-1-cyclohexanol useful as a hydrosilylation reaction inhibitor

Patent metadata

Field	Value
Publication number	US-10876019-B2
Application number	US-201816635336-A
Country	US
Kind code	B2
Filing date	Oct 17, 2018
Priority date	Oct 19, 2017
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

A hydrosilylation curable composition includes a new 2-substituted-1-alkynyl-1-cyclohexanol as an inhibitor. The hydrosilylation curable composition is useful for preparing release coatings for packaging applications.

First claim

The invention claimed is:

1. A curable composition comprises:
A) a polyorganosiloxane containing at least two silicon-bonded aliphatically unsaturated groups per molecule;
B) a polyorganohydrogensiloxane having an average, per molecule, of at least 2 silicon bonded hydrogen atoms;
with the provisos that
when starting material A) has an average, per molecule, of 2 silicon aliphatically unsaturated groups, then starting material B) has an average, per molecule, of greater than 2 silicon bonded hydrogen atoms; and
when starting material B) has an average, per molecule, of 2 silicon bonded hydrogen atoms, then starting material A) has an average, per molecule, of greater than 2 silicon bonded aliphatically unsaturated groups;

C) a hydrosilylation-reaction catalyst; and
D) a 2-substituted 1-alkynyl-1-cyclohexanol, where starting material D) has general formula

where R 3 is an alkynyl group having at least 2 carbon atoms, each R is methyl or isopropyl, subscript v is 0 to 2, subscript w is 0 to 2, subscript x is 0 to 2, subscript y is 0 to 2, subscript z is 0 to 2, with the provisos that a quantity (v+w+x+y+z)>1, and a quantity (y+z) is 1 to 4.

2. The curable composition of claim 1 , where
Starting material A) comprises a branched siloxane of unit formula (R 1 3 SiO 1/2 ) p (R 2 R 1 2 SiO 1/2 ) q (R 1 2 SiO 2/2 ) r (SiO 4/2 ) s , where each R 1 is independently a monovalent hydrocarbon group free of aliphatic unsaturation or a monovalent halogenated hydrocarbon group free of aliphatic unsaturation and each R 2 is an aliphatically unsaturated monovalent hydrocarbon group, subscript p≥0, subscript q>0, 15≥r≥995, and subscript s is >0;
Starting material B) comprises a polyorganohydrogensiloxane of unit formula (R 6 3 SiO 1/2 ) hh (R 5 2 SiO 2/2 ) ii (R 5 HSiO 2/2 ) jj ,

where each R 6 is independently hydrogen or R 5 , each R 5 is a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group, and subscript hh≥2, subscript ii≥0, and subscript jj≥2;
Starting material C) comprises a platinum catalyst; and the curable composition is a release coating composition.

3. The composition of claim 1 , where in starting material D) R 3 is an alkynyl group of 2 to 6 carbon atoms, each R is methyl, with the provisos that a quantity (v+w+x)=0, and the quantity (y+z) is 2.

4. The composition of claim 1 , where each R 3 is an alkynyl group of 2 to 6 carbon atoms, the quantity (y+z) is 1 to 2, and the quantity (v+w+x+y+z) is 1 to 4.

5. The composition of claim 4 , where each R 3 is ethynyl.

6. The composition of claim 5 , where subscript w=1, subscript y=1, and subscripts v=x=z=0.

7. The composition of claim 5 , where subscript y=2 and subscripts v=w=x=z=0.

8. The composition of claim 5 , where the composition is a release coating composition, and the release coating composition further comprises one or more of E) a polydiorganosiloxane having an average of one or more terminally aliphatically unsaturated groups per molecule, F) an anchorage additive, G) a solvent H) an anti-mist additive, I) a controlled release agent, and J) a colorant.

9. The composition of claim 1 , where starting material D) is selected from the group consisting of general formula D1), general formula D2), or both D1) and D2), where:
D1) is

 and D2) is

10. The composition of claim 9 , where the composition is a release coating composition, and the release coating composition further comprises one or more of E) a polydiorganosiloxane having an average of one or more terminally aliphatically unsaturated groups per molecule, F) an anchorage additive, G) a solvent H) an anti-mist additive, I) a controlled release agent, and J) a colorant.

11. A method for preparing the curable composition of claim 1 , where the method comprises: 1) combining starting materials comprising A), B), C) and D) at room temperature of 25° C. or less.

12. The method of claim 11 , where step 1) comprises mixing the starting materials, thereby forming a mixture; the curable composition is a release coating composition; and the release coating composition further comprises one or more of E) a polydiorganosiloxane having an average of one or more terminally aliphatically unsaturated groups per molecule, F) an anchorage additive, G) a solvent, H) an anti-mist additive, I) a controlled release agent, and J) a colorant.

13. A method for preparing a release liner comprising: applying the mixture of claim 12 on a substrate and curing the release coating composition.

14. The method of claim 13 , further comprising one or both of: treating the substrate before applying the mixture on the substrate and removing solvent before curing the release coating composition.

15. A method for forming a coating a substrate comprising:
1) applying to a substrate a curable composition comprising
A) a polyorganosiloxane containing at least two silicon-bonded aliphatically unsaturated groups per molecule;
B) a polyorganohydrogensiloxane having an average, per molecule, of at least 2 silicon bonded hydrogen atoms;
with the provisos that
when starting material A) has an average, per molecule, of 2 silicon aliphatically unsaturated groups, then starting material B) has an average, per molecule, of greater than 2 silicon bonded hydrogen atoms; and
when starting material B) has an average, per molecule, of 2 silicon bonded hydrogen atoms, then starting material A) has an average, per molecule, of greater than 2 silicon bonded aliphatically unsaturated groups;

C) a hydrosilylation-reaction catalyst; and
D) a 2-substituted 1-alkynyl-1-cyclohexanol, where starting material D) has general formula

where R 3 is an alkynyl group having at least 2 carbon atoms, each R is methyl or isopropyl, subscript v is 0 to 2, subscript w is 0 to 2, subscript x is 0 to 2, subscript y is 0 to 2, subscript z is 0 to 2, with the provisos that a quantity (v+w+x+y+z)>1, and a quantity (y+z) is 1 to 4,
optionally 2) treating the substrate before applying the composition, and 3) heating the composition, thereby curing composition to form the coating on the substrate.

16. A coated substrate prepared by the method of claim 15 .

17. The coated substrate of claim 16 , where the composition is a release coating composition.

18. The coated substrate of claim 17 , where the coated substrate is a release liner.

Assignees

• Dow Silicones Corp

Inventors

• Li Zhanjie
• Niu Zhenbin

Classifications

• C09D183/04 Primary

  Polysiloxanes · CPC title

• C09D7/65

  macromolecular (C09D7/41-C09D7/48 take precedence) · CPC title

• C08L83/04

  Polysiloxanes · CPC title

• C08K5/56

  Organo-metallic compounds, i.e. organic compounds containing a metal-to-carbon bond · CPC title

• C08G77/20

  containing silicon bound to unsaturated aliphatic groups · CPC title