摘要 |
A composition for foaming polyester which includes a carbonate or bicarbonate salt and water intermixed with a finely divided solid free flow agent such a synthetic amorphous silica. The free flow agent is added in an amount sufficient to absorb all of the water and render the composition a free flowing powder. The composition is readily mixable with an unsaturated polyester resin media. A source of acid in the mixture liberates gas from the carbonate or bicarbonate, and good foam structures having small uniform cells are obtained.
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