Chemical composition and process

Abstract

The invention relates to a solid powdery composition comprising unexpanded thermally expandable microspheres including a thermoplastic polymer shell encapsulating a propellant and from about 0.1 to about 50 wt % of at least one inhibitor selected from the group consisting of acids having a melting point below about 200° C. and precursors therefore. The invention further relates to preparation and use thereof, a composition comprising a polymeric resin, preparation thereof, a process for working a polymeric resin and a material obtainable thereby.

Description

Claims

1. Solid powdery composition comprising expanded or unexpanded thermally expandable microspheres including a thermoplastic polymer shell encapsulating a propellant and from about 0.1 to about 50 wt % of at least one inhibitor selected from the group consisting of acids having a melting point below about 200° C. and precursors therefore, said acid not being citric acid.

2. Composition as claimed in claim 1, wherein the polymer shell of the microspheres is made from homo- or co-polymers obtained by polymerising ethylenically unsaturated monomers.

3. Composition as claimed in claim 2, wherein the ethylenically unsaturated monomers comprise nitrile containing monomers.

4. Composition as claimed in claim 1, wherein the at least one inhibitor is selected from the group consisting of carboxylic acids and precursors therefore.

5. Composition as claimed in claim 4, wherein the at least one inhibitor is selected from the group consisting of formic acid, benzoic acid, oxalic acid, azelaic acid, malonic acid, malic acid, succinic acid, maleic acid, phthalic acid, acrylic acid, methacrylic acid, mixtures thereof and precursors therefore.

6. Composition as claimed in claim 5, wherein the at least one inhibitor is selected from the group consisting of maleic acid, maleic acid anhydride, phthalic acid, phthalic acid anhydride, oxalic acid, succinic acid, succinic acid anhydride and mixtures thereof.

7. Composition as claimed in claim 6, wherein the at least one inhibitor comprises maleic or a precursor therefore.

8. Composition comprising a polymeric resin, expanded or thermally expandable microspheres including a thermoplastic polymer shell encapsulating a propellant, and from about 0.1 to about 50 wt %, based on the amount of the microspheres, of at least one inhibitor selected from the group consisting of acids having a melting point below about 200° C. and precursors therefore, said acid not being citric acid.

9. Composition as claimed in claim 8, wherein the polymer shell of the microspheres is made from homo- or co-polymers obtained by polymerising ethylenically unsaturated monomers.

10. Composition as claimed in claim 9, wherein the ethylenically unsaturated monomers comprise nitrile containing monomers.

11. Composition as claimed in claim 8, wherein the at least one inhibitor is selected from the group consisting of carboxylic acids and precursors therefore.

12. Composition as claimed in claim 11, wherein the at least one inhibitor is selected from the group consisting of formic acid, benzoic acid, oxalic acid, azelaic acid, malonic acid, malic acid, succinic acid, maleic acid, phthalic acid, acrylic acid, methacrylic acid, mixtures thereof and precursors therefore.

13. Composition as claimed in claim 12, wherein the at least one inhibitor is selected from the group consisting of maleic acid, maleic acid anhydride, phthalic acid, phthalic acid anhydride, oxalic acid, succinic acid, succinic acid anhydride and mixtures thereof.

14. Composition as claimed in claim 13, wherein the at least one inhibitor comprises maleic acid or a precursor therefore.

15. Composition as claimed in claim 8, wherein the composition comprising a polymeric resin comprises 0.5 to about 20 wt % of the microspheres.

16. A process for the preparation of a composition according to claim 1 comprising mixing unexpanded thermally expandable microspheres including a thermoplastic polymer shell encapsulating a propellant with from about 0.1 to about 50 wt % of at least one inhibitor selected from the group consisting of acids having a melting point below about 200° C. and precursors therefore, said acid not being citric acid.

17. A process for the preparation of a composition according to claim 8 comprising mixing a polymeric resin with expanded or unexpanded thermally expandable microspheres including a thermoplastic polymer shell encapsulating a propellant and with from about 0.1 to about 50 wt % of at least one inhibitor selected from the group consisting of acids having a melting point below about 200° C. and precursors therefore, said acid not being citric acid.

18. A process for working a polymeric resin in a composition comprising a polymeric resin, expanded or thermally expandable microspheres including a thermoplastic polymer shell encapsulating a propellant, and from about 0.1 to about 50 wt %, based on the amount of the microspheres, of at least one inhibitor selected from the group consisting of acids having a melting point below about 200° C. and precursors therefore, said acid not being citric acid, said process comprising a step of heating the resin and forming it to a desired shape.

19. A process as claimed in claim 18, wherein the working is carried out at a temperature of at least about 100° C.

20. A process as claimed in claim 19, wherein the working is carried out at a temperature of at least about 180° C.

21. A process as claimed in claim 18, wherein the working include one or more of calendering, extrusion, blow and injection moulding.