Abstract: The invention relates to a process for (co)polymerizing vinyl monomers in the presence of a radical polymerization initiator, characterized in that said radical polymerization initiator is a 3-methylpentyl-3-peroxy alkanoate of formula (I) wherein R.sub.1, R.sub.2 and R.sub.3 represent alkyl groups each having at most 9 carbon atoms with the proviso that the total number of carbon atoms of R.sub.1, R.sub.2 and R.sub.3 is at most 11, said 3-methylpentyl-3-peroxy alkanoate being employed in an amount of 0.002 to 2.0 parts by weight, based on 100 parts by weight of monomers present, said process being carried out at a temperature above 20.degree. C. The use of 3-methylpentyl-3-peroxy alkanoates in the present invention surprisingly and unexpectedly results in a higher polymerization velocity, a shortened polymerization time, and an increase in conversion as compared with the results obtained by using other radical polymerization initiators.

Abstract: A process for the copolymerization of styrene or .alpha.-methylstyrene with an unsaturated acid derivative is disclosed. The process is carried out in the presence of a tetrafunctional organic peroxide and produces copolymeric products having significantly improved properties.

Abstract: An automatic pressurized connecting device having a wide angle of attachment and in which thermal seizure is eliminated. The device includes a main frame mounted on wheels which run on rails, a rotary shaft fitted on the main frame, a first bracket mounted on the rotary shaft, and the body rockably coupled to the first bracket. A main shaft is inserted into a central portion of the body and the high pressure water supplying rotary universal joint is coupled to a front end portion of the main shaft. A seal plug is coupled to a front end portion of the universal joint. A motor is provided on a second bracket for rotating the main shaft. A high pressure water supplying port in the body communicates with a water supplying port formed in a front end portion of the main shaft.