US 12,729,279 B2Granted

Preparation of foamed silicone elastomers

AssigneesDow Global Technologies LLC, Dow Silicones Corporation

InventorsAndrew B. Shah, Douglas A. Brune, Jody J. Henning, Nicholas A. Paulik, Mark F. Sonnenschein, Jarred Q. Cramton, Mark Fisher, Greg Becker, Chris Windiate, David Shawl, David R. Schlader, Eric J. Hukkanen

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Abstract

This disclosure relates to continuous methods of making foamed silicone elastomers. This disclosure also relates to compositions used for forming foamed silicone elastomers. The compositions comprise: (i) an organopolysiloxane having at least two silicon-bonded unsaturated groups per molecule; (ii) an organohydrogensiloxane having at least two silicon-bonded hydrogen atoms per molecule; (iii) a hydrosilylation catalyst; and (iv) a physical blowing agent. Foamed silicone elastomers can be prepared from such compositions, using, for example, the methods disclosed herein.

Claims18

Dependent claims

A continuous method for forming a foamed silicone elastomer from a composition, the composition comprising:

(i) an organopolysiloxane having at least two silicon-bonded ethylenically unsaturated groups per molecule;
(ii) an organohydrogensiloxane having at least two silicon-bonded hydrogen atoms per molecule;
(iii) a hydrosilylation catalyst;
and
(iv) a physical blowing agent;
wherein said method comprises the steps of:
(a) blending a part A composition comprising components (i) and (iii) and separately blending a part B composition comprising components (i) and (ii);
(b) introducing the part A composition and the Part B composition into respective mixing containers and mixing;
(c) transferring resulting part A and part B mixtures of step (b) into respective pumping means;
(d) pumping the resulting part A and part B mixtures of steps (b) and (c) into a mixer unit and mixing to form a foam in the mixer unit;
and
(e) dispensing the resulting foam;
wherein
(f) component (iv) is introduced into one or both of the part A composition or the part B composition during step (a) or step (b) and/or is introduced into the mixer unit during step (d);
and
wherein step (f) takes place at a temperature≤the boiling point of the physical blowing agent (iv).

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/796,998Filed 3 Feb 2021 · us provisional application
Priority: 5 Feb 2020
Published: US 2023/0073487 A19 Mar 2023
Granted: 8 Sep 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification20 codes

C08J 9/12
Using blowing gases generated by a previously added blowing agent: by a physical blowing agent
C08J 9/146
Containing carbon, halogen and hydrogen only: only fluorine as halogen atoms
B29B 7/7404
Using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant: mixing devices specially adapted for foamable substances
B29B 7/749
With consecutive mixers, e.g. with premixing some of the components: with stirring means for the individual components before they are mixed together