# US 8,569,439 B2 · Hardener for silicone rubber materials

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- Number: US 8,569,439 B2
- Document ID: US8569439B2
- Status: Granted
- Kind: B2
- Application number: 12/673,080
- Filed: 2008-08-29
- Published: 2012-01-19
- Granted: 2013-10-29
- Earliest claimed: 2007-08-31
- Assignees: Nitro-Chemie Aschau GmbH
- Applicants: Theodor Ederer; Thomas Knott; Ulrich Pichl; Gerhard Schmidt; Ludwig Waldmann
- Inventors: Theodor Ederer; Thomas Knott; Ulrich Pichl; Gerhard Schmidt; Ludwig Waldmann
- Web page: https://patentgrep.com/patent/US8569439B2

## CPC

- C08K 5/5425: containing at least one C=C bond
- C07F 7/1804: {Compounds having Si-O-C linkages (Si-O-acyl linkages C07F7/1896)}
- C08K 5/5419: containing at least one Si—C bond
- C08G 77/16: to hydroxy groups
- C08K 5/57: Organo-tin compounds
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22)
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

## Abstract

A hardener for silicone rubber materials comprising a silane compound which comprises a 2-hydroxy-propionic acid alkyl ester radical.

## Claims

### Claim 1

A hardener for silicone rubber materials, comprising:
a) a compound having the general formula Si(R1)3R2 (I), wherein
radicals R1 are 2-hydroxy-propionic acid alkyl ester radicals having the general formula —OCH(CH3)COOR,
radical R is selected from a group consisting of a methyl radical, an ethyl radical, a propyl radical and an isopropyl radical, and
radical R2 is selected from a group comprising at least one of a straight-chain or branched alkenyl radical which has at least two carbon atoms; and
b) a compound having the general formula Si(R3)nR4m (II), wherein
n=1, 2, 3, or 4 and in (4−n),
radical R3 is a 2-hydroxy-propionic acid alkyl ester radical of the general formula —OCH(CH3)COOR,
radical R is selected from a group consisting of a methyl radical, an ethyl radical, a propyl radical, and an isopropyl radical, and
radical R4 is at least one selected from a group comprising
a straight-chain branched alkyl radical, which has at least one carbon atom,
a straight-chain or branched alkenyl radical or alkinyl radical, which has at least two carbon atoms,
a cycloalkyl radical, which has at least three carbon atoms, and
an aryl radical, which has at least five carbon atoms; and
(c) wherein the compounds of general formulas (I) and (II) are different compounds.

### Claim 2 (depends on 1)

The hardener as claimed in claim 1, wherein the radical R2 is at least one selected from a group comprising an allyl radical and a vinyl radical.

### Claim 3 (depends on 1)

The hardener as claimed in claim 1, wherein the radical R of general formula (I) is an ethyl radical.

### Claim 4 (depends on 1)

The hardener as claimed, in claim 1, wherein the compound a) is vinyl-tris-(ethyl lactato)-silane.

### Claim 5 (depends on 1)

The hardener as claimed in claim 1, wherein radical R4 is at least one selected from a group comprising a methyl radical, an ethyl radical, a propyl radical, an isopropyl radical, a butyl radical, an isobutyl radical, a sec-butyl radical, a tert-butyl radical, an allyl radical, a vinyl radical, a cyclopentyl radical, a cyclohexyl radical, a phenyl radical, and a diphenyl radical.

### Claim 6 (depends on 1)

The hardener as claimed in claim 1, wherein radical R of radical R3 of general formula (II) is an ethyl radical.

### Claim 7 (depends on 1)

The hardener as claimed in claim 1, wherein the compound of the general formula (II) is at least one selected from a group comprising methyl-tris-(ethyl lactato)-silane, ethyl-tris-(ethyl lactato)-silane, and tetra-(ethyl lactato)-silane.

### Claim 8 (depends on 1)

A method for curing a silicone rubber material comprising the steps of:
providing an organosilicone compound and a hardener as described in claim 1, and
mixing the organosilicone compound and hardener.

### Claim 9 (depends on 1)

A composition, comprising the hardener as claimed in claim 1 and an organosilicone compound.

### Claim 10 (depends on 9)

The composition as claimed in claim 9, wherein the organosilicone compound is an α,ω-dihydroxyl-terminated polyorganosiloxane compound.

### Claim 11 (depends on 9)

The composition as claimed in claim 9, comprising from 40 to 90% by weight of the organosilicone compound and from 1 to 15% by weight of the hardener.

### Claim 12 (depends on 1)

A method of forming a sealant, adhesive or coating material comprising the steps of:
providing an organosilicone compound and a hardener as described in claim 1, and
mixing the organosilicone compound and hardener, and exposing the mixture to water or humidity of the air at room temperature.

### Claim 13 (depends on 1)

A method of preparing a hardener as claimed in claim 1, comprising:
(I) reacting a compound of general formula SiX3R2 (III) with three equivalents of alkyl lactate (hydroxy-propionic acid alkyl ester), the alkyl radical of the alkyl lactate being selected from a group consisting of a methyl radical, an ethyl radical, a propyl radical and an isopropyl radical, and
wherein radical R2 is selected from at least one of a straight-chain or branched alkenyl or alkinyl radical, which each has at least two carbon atoms, and
wherein radical X is selected from a group comprising an alkoxy radical, which has at least one carbon atom and a halogen atom; and
(II) mixing the compound formed in step (I) with a compound having the general formula Si(R3)nR4m (II), wherein
n=1, 2, 3, or 4 and m=(4−n),
radical R3 is a 2-hydroxy-propionic acid alkyl ester radical of the general formula —OCH(CH3)COOR,
radical R is selected from a group consisting of a methyl radical, an ethyl radical, a propyl radical, and an isopropyl radical, and
radical R4 is at least one selected from a group comprising
a straight-chain branched alkyl radical, which has at least one carbon atom,
a straight-chain or branched alkenyl radical or alkinyl radical, which has at least two carbon atoms,
a cycloalkyl radical, which has at least three carbon atoms, and
an aryl radical, which has at least five carbon atoms.

### Claim 14 (depends on 10)

The composition as claimed in claim 10, wherein the organosilicone compound is an α,ω-dihydroxyl-terminated polydialkylsiloxane.

### Claim 15 (depends on 13)

The method as claimed in claim 13, wherein the halogen atom is a chlorine atom.