Polymer and polymer compositions

• US 8,592,545 B2
• Filed: 04/30/2008
• Issued: 11/26/2013
• Est. Priority Date: 05/01/2007
• Status: Expired due to Fees

• Current Assignee: Dow Silicones Corporation (Dow, Inc.)
• Original Assignee: Dow Corning Corporation (Dow, Inc.)
• Inventors: Mackinnon, Iain A., De Buyl, Francois, Durand, Geraldine, O'Hare, Sarah
• Primary Examiner(s): MOORE, MARGARET G
• Application Number:
  US12/597,783
• Publication Number:
  US 20100168309A1
• Time in Patent Office: 2,036 Days
• Field of Search: 528/29, 528/21, 528/14, 528/17, 528/18, 525/477
• US Class Current: 528/14
• CPC Class Codes: C08G 77/46 containing polyether sequences
• CPC Class Codes: C08K 5/54 Silicon-containing compounds C08K5/0091 takes precedence
• CPC Class Codes: C08L 2666/44 Silicon-containing compounds
• 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
• CPC Class Codes: C08L 83/12 containing polyether sequences

Abstract

A polyorganosiloxane polyoxyalkylene block copolymer having one or more polyorganosiloxane blocks and one or more polyoxyalkylene blocks linked to each other via divalent radicals which comprises at least two silicon-bonded alkoxy groups, preferably of the form PS (A PO)_m (A PS)_n, wherein PO is a polyoxyalkylene block, PS represents a polyorganosiloxane block, A is a divalent radical, m and n have independently a value of at least 1, comprising at least one alkoxy-substituted siloxane unit of the formula (R′)_q(OR)—SiO_{3−q/2 ′}, wherein R represents an alkyl group having 1 to 4 carbon atoms and each R′ represents an alkyl group having 1 to 6 carbon atoms, a phenyl group, or an alkoxy group of the formula —OR and q has a value of 0, 1 or 2, provided at least two silicon-bonded groups OR are present in the block copolymer. Also provided is a curable composition of the above which may comprise a condensation catalyst and a hydrophilic polymer network made from curing the composition in the presence of moisture, which exhibit interesting reversible hydrophilic properties.

Claims

1. A polymer composition curable to a water-insoluble hydrophilic polymer network, said composition comprising a polyorganosiloxane polyoxyalkylene block copolymer of the form

PS-(A-PO-A-PS)_n, wherein

PS represents a polydimethylsiloxane block having from 4 to 40 siloxane units terminated with an alkoxy-substituted siloxane unit which is linked via oxygen to another silicon atom of the PS block and which has the formula

2. A curable polymer composition according to claim 1, which further comprises a condensation catalyst selected from the group consisting of protic acids, Lewis acids, organic and inorganic bases, transition metal compounds, metal salts and organometallic complexes.

3. A curable polymer composition according to claim 2, wherein the siloxane condensation catalyst comprises a compound of a transition metal selected from titanium, zirconium and hafnium.

4. A curable polymer composition according to claim 3, wherein the catalyst is a titanium tetraalkoxide or chelated titanium alkoxide.

5. A curable polymer composition according to claim 2, wherein the siloxane condensation catalyst comprises an organic compound of tin.

6. A curable polymer composition according to claim 1, which further comprises a contain a filler selected from the group consisting of silica, fumed silica, fused silica, precipitated silica, barium sulphate, calcium sulphate, calcium carbonate, silicates, talc, feldspar, china clay, bentonite, and and solid silicone resins.

7. A curable polymer composition according to claim 1, wherein the composition contains a siloxane condensation catalyst and in that the composition is packed in a moisture-proof container.