Abstract: The present invention provides a method for preventing polymerization, and a polymerizable monomer composition favorably used therefor that includes a (meth)acryloyl group-containing isocyanate compound and a specific polymerization inhibitor. The polymerizable monomer composition includes a (meth)acryloyl group-containing isocyanate compound and a stable free radical compound. The invention effectively prevents the polymerization of the (meth)acryloyl group-containing isocyanate compound and the occurrence of polymers due to the polymerization. Furthermore, the use of a stable free radical compound which has a vapor pressure approximate to that of the (meth)acryloyl group-containing isocyanate compound can effectively prevent polymerization in a vapor phase and a condensation phase of distillation facility.

Abstract: The present invention provides a method for preventing polymerization, and a polymerizable monomer composition favorably used therefor that includes a (meth)acryloyl group-containing isocyanate compound and a specific polymerization inhibitor. The polymerizable monomer composition includes a (meth)acryloyl group-containing isocyanate compound and a stable free radical compound. The invention effectively prevents the polymerization of the (meth)acryloyl group-containing isocyanate compound and the occurrence of polymers due to the polymerization. Furthermore, the use of a stable free radical compound which has a vapor pressure approximate to that of the (meth)acryloyl group-containing isocyanate compound can effectively prevent polymerization in a vapor phase and a condensation phase of distillation facility.

Abstract: An object of the invention is to provide a process for industrially producing fluorinated dicyanobenzenes using tetrachlorodicyanobenzene as a raw material. According to the present invention, fluorinated dicyanobenzene can be produced in a high yield by allowing tetrachlorodicyanobenzenes to react with a fluorinating agent in the presence of a non-protonic polar solvent in an amount of 0.1 to 3 times by mass based on the tetrachlorodicyanobenzene. Further, the above production can be conducted more efficiently by reacting while disintegrating or removing bulk solid matters.

Abstract: The present invention relates to a process by a series of reactions using tetrafluorocyanobenzens as material for producing tetrafluorobenzenemethanols, tetrafluorobenzenecarbaldehyde dialkylacetals and tetrafluorobenzenecarbaldehydes in a high purity and a high yield which are useful as intermediates in the production of cyclopropanecarboxylic acid esters having insecticidal action, and also relates to a novel tetrafluorobenzenecarbaldehyde dimethylacetal.