Use of tocopherol

• US 8,044,161 B2
• Filed: 03/11/2008
• Issued: 10/25/2011
• Est. Priority Date: 03/12/2007
• Status: Active Grant

• Current Assignee: Bayer Schering Pharma OY (Bayer AG)
• Original Assignee: Bayer Schering Pharma AG (Bayer AG)
• Inventors: Jukarainen, Harri, Tiitinen, Emilia
• Primary Examiner(s): LOEWE, ROBERT S
• Application Number:
  US12/529,338
• Publication Number:
  US 20100036079A1
• Time in Patent Office: 1,323 Days
• Field of Search: None
• US Class Current: 528/15
• 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 77/38 Polysiloxanes modified by chemical after-treatment C08G77/045 takes precedence

Abstract

The present invention relates to the use of tocopherol as a co-catalyst in the ring opening polymerisation of cyclic siloxanes. The present invention further relates to a method for manufacturing hydrophilic polysiloxanes, wherein a hydrido-containing cyclic siloxane is reacted with a hydrophilic molecule comprising a carbon-carbon double bond, having the general formula (I) H₂C═CH—(CHR)_n—O—(CHR¹CR²R³)_mR⁴ or (II) H₂C═CH—(CHR)_n—R⁵, wherein n is an integer from 0 to 4, m is an integer from 0 to 5, R, R¹, R², R³ and R⁴ are each independently hydrogen or a C₁ to C₆ alkyl, R⁵ is a saturated cyclic hydrocarbon containing carbonyl group, in the presence of a first catalyst to obtain a monomer, and polymerising said monomer in the presence of a second catalyst and tocopherol as a co-catalyst.

Claims

1. A method for manufacturing hydrophilic polysiloxanes, wherein a hydrido-containing cyclic siloxane is reacted with a hydrophilic molecule comprising a carbon-carbon double bond, having the general formula (I) or (II)

H₂C═

CH—

(CHR)_n—

O—

(CHR¹CR²R³)_mR⁴ 

 

(I)

H₂C═

CH—

(CHR)_n—

R⁵ 

 

(II)

wherein n is an integer from 0 to 4, m is an integer from 0 to 5, R, R¹, R², R³ and R⁴ are each independently hydrogen or a C₁ to C₆ alkyl, R⁵ is a saturated cyclic hydrocarbon containing carbonyl group, in the presence of a first catalyst to obtain a monomer, and polymerising said monomer in the presence of a second catalyst and tocopherol as a co-catalyst.

2. The method according to claim 1, wherein the cyclic siloxane is selected from the group consisting of heptamethyl cyclotetrasiloxane and tetramethyl cyclotetrasiloxane.

3. A method for manufacturing a hydrophilic siloxane elastomer, wherein a hydrido-containing cyclic siloxane is reacted with a hydrophilic molecule comprising a carbon-carbon double bond, having the general formula (I) or (II)

H₂C═

CH—

(CHR)_n—

O—

(CHR¹CR²R³)_mR⁴ 

 

(I)

H₂C═

CH—

(CHR)_n—

R⁵ 

 

(II)

wherein n is an integer from 0 to 4, m is an integer from 0 to 5, R, R¹, R², R³ and R⁴ are each independently hydrogen or a C₁ to C₆ alkyl, R⁵ is a saturated cyclic hydrocarbon containing carbonyl group, in the presence of a first catalyst to obtain a monomer,

polymerising said monomer in the presence of a second catalyst and tocopherol as a co-catalyst to produce a hydrophilic polysiloxane, and

cross-linking said polysiloxane in the presence of a cross-linking catalyst selected from the group consisting of peroxide cross-linking catalysts and platinum cross-linking catalysts.