| 摘要 |
PROBLEM TO BE SOLVED: To provide a production method of expandable microspheres with which the start of the polymerization reaction in an oil phase and in an aqueous phase at undesired timing such as during preparation of a dispersion liquid or before polymerization is suppressed, with which the expected polymerization reaction in the oil phase is not inhibited, and which have excellent physical property such as an expansion ratio, as well as to provide the expandable microspheres which have excellent physical property.SOLUTION: In a production method of expandable microspheres including a foaming agent sealed in the outer shell of the produced polymer and having a maximum expansion ratio of 5 times or more, a polymerizable mixture containing at least the foaming agent, a polymerizable monomer, a polymerization initiator, and a water insoluble polymerization inhibitor (preferably with solubility in water at 20°C of 1 mass% or lower) and for example vitamin E or an oil soluble aromatic compound having a hydroxy group, a quinone group, or an alkoxy group is suspended in an aqueous dispersion medium, and subsequently is subjected to suspension polymerization in the presence of the water insoluble polymerization inhibitor. Besides the expandable microspheres including the foaming agent sealed in the outer shell of the produced polymer have the maximum expansion ratio of 5 times or more and preferably have an average particle diameter of 0.5-150 μm.SELECTED DRAWING: None |
