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 as 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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