Microspheres

Patent metadata

Field	Value
Publication number	US-9902829-B2
Application number	US-201314402958-A
Country	US
Kind code	B2
Filing date	May 27, 2013
Priority date	May 30, 2012
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

The present invention relates to thermally expandable thermoplastic microspheres comprising a polymer shell made from ethylenically unsaturated monomers encapsulating a propellant, said ethylenically unsaturated monomers comprising from 21 to 80 wt % of methacrylamide and from 20 to 70 wt % methacrylonitrile, the total amount of methacrylamide and methacrylonitrile being from 70 to 100 wt % of the ethylenically unsaturated monomers. Furthermore, the invention relates to production and use of such microspheres.

First claim

The invention claimed is:

1. Thermally expandable thermoplastic microspheres comprising a polymer shell formed by a reaction product of ethylenically unsaturated monomers encapsulating a propellant, said ethylenically unsaturated monomers comprising from 31 to 80 wt % of methacrylamide and from 20 to 70 wt % methacrylonitrile, the total amount of methacrylamide and methacrylonitrile being from 70 to 100 wt % of the ethylenically unsaturated monomers.

2. The microspheres of claim 1 , wherein said ethylenically unsaturated monomers comprise from 30 to 60 wt % of methacrylonitrile.

3. The microspheres of claim 1 , wherein the total amount of methacrylamide and methacrylonitrile is from 80 to 100 wt % of the ethylenically unsaturated monomers.

4. The microspheres of claim 3 , wherein the total amount of methacrylamide and methacrylonitrile is from 90 to 100% of the ethylenically unsaturated monomers.

5. The microspheres of claim 1 , wherein said ethylenically unsaturated monomers comprise from 40 to 60 wt % of methacrylamide.

6. The microspheres of claim 1 , wherein said ethylenically unsaturated monomers comprise from 40 to 60 wt % of methacrylonitrile.

7. The microspheres of claim 1 , wherein said ethylenically unsaturated monomers comprise less than 10 wt % of carboxylic acid containing monomers.

8. The microspheres of claim 1 , wherein said propellant comprises a hydrocarbon selected from the group consisting of isobutane, isopentane, isohexane, cyclohexane, isooctane, isododecane, and mixtures thereof, preferably isooctane.

9. The microspheres of claim 8 , wherein said propellant comprises from 50 to 100 wt % of isooctane.

10. A process for the production of the thermally expandable microspheres of claim 1 , comprising the steps of polymerising ethylenically unsaturated monomers in the presence of a propellant to yield microspheres comprising a polymer shell encapsulating said propellant, said ethylenically unsaturated monomers comprising from 31 to 80 wt % of methacrylamide and from 20 to 70 wt % methacrylonitrile, the total amount of methacrylamide and methacrylonitrile being from 70 to 100 wt % of the ethylenically unsaturated monomers.

11. Expanded microspheres prepared by a process comprising the step of expanding the expandable microspheres of claim 1 .

12. An expandable formulation comprising a thermoplastic polymer matrix and the expandable microspheres of claim 1 .

13. A foaming agent comprising the thermally expandable microspheres of claim 1 .

14. A method of molding polymeric materials comprising the step of combining the thermally expandable microspheres of claim 1 with a molding material.

15. The microspheres of claim 1 , wherein said ethylenically unsaturated monomers are free from carboxylic acid containing monomers.

16. The foaming agent of claim 13 comprising an expandable formulation including a thermoplastic polymer matrix and the thermally expandable microsphere.

17. The method of claim 14 comprising an expandable formulation including a thermoplastic matrix and the thermally expandable microsphere.

Assignees

• Akzo Nobel Chemicals Int Bv

Inventors

• Nordin Ove

Classifications

• C08J2333/26

  Homopolymers or copolymers of acrylamide or methacrylamide · CPC title

• B29C70/66

  the filler comprising hollow constituents, e.g. syntactic foam · CPC title

• B01J13/185

  in an organic phase · CPC title

• B29C67/247

  Moulding polymers or prepolymers containing ingredients in a frangible packaging, e.g. microcapsules (expandable components kept in frangible containers within a flexible bag B29C44/183) · CPC title

• B01J13/18

  In situ polymerisation with all reactants being present in the same phase · CPC title