| 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 at undesired timing such as during preparation of a dispersion liquid or before the start of the 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 soluble polymerization inhibitor preferably with solubility in water at the temperature of 20°C of more than 1 mass% and a compound for example a naphthohydroquinone compound or a nitroso compound is suspended in an aqueous dispersion medium, and subsequently is subjected to suspension polymerization in the presence of the water soluble 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 |
