Method for controlling a process for the production of a polymer by polymerization of a monomer and a comonomer. The process includes maintaining a substantially constant effective flow ratio (EFR), the effective flow ratio being defined as EFR=(Q.sub.comoL.sub.como)/(Q.sub.monoL.sub.mono), Q.sub.como and Q.sub.mono being, respectively, flow rates of comonomer and monomer to the reactor, L.sub.como and L.sub.mono being, respectively, losses of comonomer and monomer.

The present invention provides a cationically curable resin composition for assembling hard disk devices which comprises a resin having a cationically polymerizable functional group (a component A) and a cationic polymerization initiator (a component B), the component B being at least one selected from the group consisting of X.sup.+(SbF.sub.6).sup.(B1), X.sup.+(B(C.sub.6F.sub.5).sub.4).sup.(B2) and X.sup.+((Rf).sub.nPF.sub.6-n).sup.(B3) (in the formulae, X.sup.+ is iodonium or sulfonium, Rf is a fluorinated alkyl having 1 to 6 carbon atoms, and n is an integer of 1 to 6). The invention also provides a hard disk device manufacturing method using the composition, and a hard disk device assembled with the composition.

The present invention provides a cationically curable resin composition for assembling hard disk devices which comprises a resin having a cationically polymerizable functional group (a component A) and a cationic polymerization initiator (a component B), the component B being at least one selected from the group consisting of X.sup.+(SbF.sub.6).sup.(B1), X.sup.+(B(C.sub.6F.sub.5).sub.4).sup.(B2) and X.sup.+((Rf).sub.nPF.sub.6-n).sup.(B3) (in the formulae, X.sup.+ is iodonium or sulfonium, Rf is a fluorinated alkyl having 1 to 6 carbon atoms, and n is an integer of 1 to 6). The invention also provides a hard disk device manufacturing method using the composition, and a hard disk device assembled with the composition.

A procedure for improved temperature control in controlled radical polymerization processes is disclosed. The procedure is directed at controlling the concentration of the persistent radical in ATRP and NMP polymerizations procedures and the concentration of radicals in a RAFT polymerization process by feeding a reducing agent or radical precursor continuously or intermittently to the reaction medium through one of more ports.

A procedure for improved temperature control in controlled radical polymerization processes is disclosed. The procedure is directed at controlling the concentration of the persistent radical in ATRP and NMP polymerizations procedures and the concentration of radicals in a RAFT polymerization process by feeding a reducing agent or radical precursor continuously or intermittently to the reaction medium through one of more ports.

Acrylic copolymers that include the controlled placement of functional groups within the polymer structure are provided. The copolymers contain a reactive segment and a non-reactive segment and are manufactured via a controlled radical polymerization process. The copolymers are useful in the manufacture of adhesives and elastomers.

Acrylic copolymers that include the controlled placement of functional groups within the polymer structure are provided. The copolymers contain a reactive segment and a non-reactive segment and are manufactured via a controlled radical polymerization process. The copolymers are useful in the manufacture of adhesives and elastomers.

A carrier for an olefin polymerization catalyst contains a magnesium-containing compound and sulfur. The sulfur is at least one of an elemental sulfur, a complex sulfur, and a compound sulfur. The carrier has good particle morphology and a smooth surface, and has a narrow particle size distribution. The catalyst prepared from the carrier has high activity and good sensitivity to hydrogen regulation, and can improve the density of a polymer stack when being used for olefin polymerization.

Methods for making titanated silica supports, titanated chromium/silica pre-catalysts, and activated titanated chromium/silica catalysts are disclosed in which hydrogen peroxide and an alkali metal precursor are used during catalyst preparation. Resulting titanated chromium/silica pre-catalysts often contain silica, 0.1 to 5 wt. % chromium, 0.1 to 10 wt. % titanium, and less than or equal to 4 wt. % carbon, and further contain a bound alkali metal or zinc at a molar ratio of alkali metal:titanium or zinc:titanium from 0.02:1 to 3:1 and/or at an amount in a range from 0.01 to 2 mmol of alkali metal or zinc per gram of the silica. High melt index potential activated titanated chromium/silica catalysts can be used to polymerize olefins to produce, for example, ethylene based homopolymers and copolymers having HLMI values of greater than 30 g/10 min.

Embodiments disclosed herein relate to a use of propane contained in a propylene feedstock for setting up impact copolymer polypropylene production in at least two polymerization zones comprising accumulating the propane in a first polymerization zone (2, 5) during a parallel operation mode of the first polymerization zone (2, 5) and a second polymerization zone (7, 10) producing respective propylene polymers. Embodiments disclosed herein also relate to a process and a system for setting up impact copolymer polypropylenes production.