# US 2026/0273516 A1 · Encapsulated catalyst, method of preparation, composition and methods involving hydrosilylation

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- Number: US 2026/0273516 A1
- Document ID: US20260273516A1
- Status: Published application
- Kind: A1
- Application number: 19/168,588
- Filed: 2024-04-03
- Published: 2026-09-17
- Earliest claimed: 2023-04-04
- Assignees: Dow Silicones Corporation; The Board of Trustees of the University of Illinois
- Applicants: Dow Silicones Corporation; The Board of Trustees of the University of Illinois
- Inventors: Matthew JELETIC; Damien GUIRONNET; Susannah HADDOCK; Ericka BRUSKE; Alison WEITZEL
- Web page: https://patentgrep.com/patent/US20260273516A1

## CPC

- B01J 31/123: {Organometallic polymers, e.g. comprising C-Si bonds in the main chain or in subunits grafted to the main chain (B01J31/064, B01J31/066, B01J31/067, B01J31/08 and B01J31/10 take precedence; polymer-bound organometallic complexes B01J31/165; coordination polymers B01J31/1691; catalysts for the preparation of polysiloxanes, e.g. Karstedt catalysts C08G77/08)}
- B01J 31/1658: {immobilised by covalent linkages, i.e. pendant complexes with optional linking groups, e.g. on Wang or Merrifield resins}
- B01J 31/2226: {Anionic ligands, i.e. the overall ligand carries at least one formal negative charge}
- C08L 83/04: Polysiloxanes
- B01J 31/181: {Cyclic ligands, including e.g. non-condensed polycyclic ligands, comprising at least one complexing nitrogen atom as ring member, e.g. pyridine}
- B01J 2231/323: Hydrometalation, e.g. bor-, alumin-, silyl-, zirconation or analoguous reactions like carbometalation, hydrocarbation
- B01J 2531/0213: Complexes without C-metal linkages
- B01J 2531/828: Platinum
- C08G 77/12: containing silicon bound to hydrogen
- C08G 77/20: containing silicon bound to unsaturated aliphatic groups
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

## Abstract

An encapsulated catalyst for hydrosilylation comprises platinum(0) and/or platinum (II). A polymer encapsulates the platinum(0) and/or platinum (II). The polymer comprises structural units, at least some of the structural units of the polymer include a pyridine moiety, and at least some of the platinum(0) and/or platinum (II) is/are bound to at least some of the pyridine moieties of the polymer. When the platinum of the encapsulated catalyst is platinum(0), the encapsulated catalyst comprises at least 500 equivalents of pyridine moieties relative to total platinum. Methods of preparing the encapsulated catalyst, and compositions including the same, are also disclosed.

## Claims

### Claim 1

An encapsulated catalyst for hydrosilylation, said encapsulated catalyst comprising:
platinum(0) and/or platinum (II); and
a polymer encapsulating the platinum(0) and/or platinum (II);
wherein the polymer comprises structural units, at least some of the structural units of the polymer include a pyridine moiety, and wherein at least some of the platinum(0) and/or platinum (II) is/are bound to at least some of the pyridine moieties of the polymer;
with the proviso that the encapsulated catalyst comprises at least 500 equivalents of pyridine moieties relative to total platinum content when the platinum is platinum(0).

### Claim 2 (depends on 1)

The encapsulated catalyst of claim 1, wherein:
(i) the encapsulated catalyst comprises at least 750 equivalents of pyridine moieties relative to total platinum content;
(ii) at least 50 mol % of the structural units of the polymer include a pyridine moiety; or
(iii) both (i) and (ii).

### Claim 3 (depends on 1)

The encapsulated catalyst of claim 1, wherein the structural units of the polymer that include a pyridine moiety are derived from 4-vinyl pyridine, and optionally wherein the polymer includes structural units derived from at least one monomer other than 4-vinyl pyridine.

### Claim 4 (depends on 3)

The encapsulated catalyst of claim 3, wherein the polymer includes structural units derived from at least one monomer other than 4-vinyl pyridine, and wherein the at least one monomer is selected from a (meth)acrylate monomer, styrene, a (meth)acrylate-functional siloxane, or combinations thereof.

### Claim 5 (depends on 4)

The encapsulated catalyst of claim 4, wherein the polymer includes structural units derived from the (meth)acrylate-functional siloxane, which has the following formula:

### Claim 6

A method of preparing an encapsulated catalyst for hydrosilylation, said method comprising:
combining platinum(0) and/or platinum (II) with a polymer; and
encapsulating the platinum(0) and/or platinum (II) with the polymer;
wherein the polymer comprises structural units, at least some of the structural units of the polymer include a pyridine moiety, and wherein at least some of the platinum(0) and/or platinum (II) is/are bound to at least some of the pyridine moieties of the polymer;
with the proviso that the encapsulated catalyst comprises at least 500 equivalents of pyridine moieties relative to total platinum content when the platinum is platinum(0).

### Claim 7 (depends on 6)

The method of claim 6, free from a step of washing the encapsulated catalyst prior to use in a hydrosilylation reaction.

### Claim 8 (depends on 6)

The method of claim 6, wherein combining platinum(0) and/or platinum (II) with the polymer comprises combining a platinum(0) complex and/or platinum (II) complex with the polymer, and wherein at least some ligands of the platinum(0) complex and/or platinum (II) complex disassociate from the platinum(0) and/or platinum (II) during encapsulation by the polymer.

### Claim 9 (depends on 8)

The method of claim 8, wherein:
(i) the platinum(0) complex has the following formula:
and
(ii) the platinum (II) complex has the following formula:

### Claim 10 (depends on 6)

The method of claim 6, wherein:
(i) the encapsulated catalyst comprises at least 750 equivalents of pyridine moieties relative to total platinum content;
(ii) at least 50 mol % of the structural units of the polymer include a pyridine moiety; or
(iii) both (i) and (ii).

### Claim 11 (depends on 1)

A composition, comprising:
(A) an unsaturated compound including at least one aliphatically unsaturated group per molecule, subject to at least one of the following two provisos:
(1) the unsaturated compound (A) also includes at least one silicon-bonded hydrogen atom per molecule; and/or
(2) the composition further comprises (B) a silicon hydride compound including at least one silicon-bonded hydrogen atom per molecule; and
(C) the encapsulated catalyst of claim 1.

### Claim 12 (depends on 11)

The composition of claim 11, wherein proviso (2) is true such that the composition further comprises (B) the silicon hydride compound including at least one silicon-bonded hydrogen atom per molecule.

### Claim 13 (depends on 1)

A method of preparing a hydrosilylation reaction product, said method comprising:
reacting an aliphatically unsaturated group and a silicon-bonded hydrogen atom in the presence of (C) an encapsulated catalyst to give the hydrosilylation reaction product;
wherein the aliphatically unsaturated group is present in (A) an unsaturated compound;
wherein at least one of the following two provisos applies:
(1) the unsaturated compound (A) also includes at least one silicon-bonded hydrogen atom per molecule; and/or
(2) the silicon-bonded hydrogen atom is present in (B) a silicon hydride compound separate from the unsaturated compound (A); and
wherein the encapsulated catalyst (C) comprises the encapsulated catalyst of claim 1.

### Claim 14 (depends on 13)

A hydrosilylation reaction product formed in accordance with the method of claim 13.

### Claim 15 (depends on 1)

A hydrosilylation-curable silicone composition or hydrosilylation reaction product comprising the encapsulated catalyst of claim 1.