| 摘要 |
PURPOSE:To facilitate the production of spherical particles which can be expanded at a high expansion ratio, by dispersing a pelletized or powdered ethylene resin in an aqueous suspending medium, adding s sytrene monomer thereto, heating the mixture and polymerizing it in the presence of a polymerization catalyst. CONSTITUTION:100pts.wt. plelletized or powdered ethylene resin of an MI<=7 is dispersed in an aqueous suspending medium. To this dispersion about 30- 150pts.wt. monomer based on a styrene monomer and/or p-methylstyrene monomer is added, and the obtained mixture is heated at about 100 deg.C or above in the absence of a polymerization promotor such as an initiator to form spherical particles. This mixture is polymerized in the presence of a polymerization catalyst (e.g. benzoly peroxide) to produce spherial ethylene resin particles. Because of the incorporation of a stytene or p-methylstyrenebased polymer having a power of retaining a blowing agent, the spherical ethylene resin particles can be expanded at a high expansion ratio when used as expandable ethylene resin particles. |
