Even when used in applications such as electronic materials, display materials, and inks, in which required standards in terms of coloring prevention, long term stability, low impurity content, and the like, are extremely high, the present invention can meet such required standards. The present invention addresses the problem of providing an allylamine (co)polymer which overcomes the limitations of the prior art, undergoes little coloring, contains little impurities and exhibits excellent long term stability; and a method for producing the same. This problem can be solved by an allylamine (co)polymer which has constituent units derived from allylamine and contains sulfuric acid groups in the structure thereof, in which the proportion of the sulfuric acid groups with respect to the total mass of the allylamine (co)polymer is 20,000 ppm by mass or less.

A process for the offline deactivation of at least one single site catalyst comprising contacting said catalyst with a deactivating agent selected from an aprotic low molecular weight carbonyl group containing organic compound or an aprotic low molecular weight orthoester or an aprotic low molecular weight acetal compound.

A process for the offline deactivation of at least one single site catalyst comprising contacting said catalyst with a deactivating agent selected from an aprotic low molecular weight carbonyl group containing organic compound or an aprotic low molecular weight orthoester or an aprotic low molecular weight acetal compound.

The purpose of the present invention is to provide: a cross-copolymer in which a residual catalyst component remains in a reduced amount and which has improved transparency, applicability to medical materials and yellowish discoloration resistance; and a method for producing the cross-copolymer. According to the present invention, a cross-copolymer is provided, wherein the cross-copolymer is produced through a coordination polymerization step of carrying out copolymerization of an olefin monomer, an aromatic vinyl compound monomer and an aromatic polyene using a single-site coordination polymerization catalyst to synthesize an olefin-(aromatic vinyl compound)-(aromatic polyene) copolymer and a subsequent anionic polymerization step of carrying out polymerization in the co-presence of the olefin-(aromatic vinyl compound)-(aromatic polyene) copolymer and an aromatic vinyl compound monomer using an anionic polymerization initiator, the cross-copolymer being characterized in that the total mass of aluminum and lithium, which are residual catalyst components, contained in the cross-copolymer is 200 ppm or less.

The purpose of the present invention is to provide: a cross-copolymer in which a residual catalyst component remains in a reduced amount and which has improved transparency, applicability to medical materials and yellowish discoloration resistance; and a method for producing the cross-copolymer. According to the present invention, a cross-copolymer is provided, wherein the cross-copolymer is produced through a coordination polymerization step of carrying out copolymerization of an olefin monomer, an aromatic vinyl compound monomer and an aromatic polyene using a single-site coordination polymerization catalyst to synthesize an olefin-(aromatic vinyl compound)-(aromatic polyene) copolymer and a subsequent anionic polymerization step of carrying out polymerization in the co-presence of the olefin-(aromatic vinyl compound)-(aromatic polyene) copolymer and an aromatic vinyl compound monomer using an anionic polymerization initiator, the cross-copolymer being characterized in that the total mass of aluminum and lithium, which are residual catalyst components, contained in the cross-copolymer is 200 ppm or less.

Described herein is a process for preparing solid acrylic acid polymers including: (a) preparing an aqueous acrylic acid polymer solution having a solids content of 30% to 70% by weight by free-radical polymerization, (b) neutralizing the aqueous acrylic acid polymer solution at least partly by adding a base, which results in release of a heat of neutralization, and concentrating the aqueous acrylic acid polymer solution by exploiting the heat of neutralization to give a highly concentrated acrylic acid polymer solution having a solids content of 60% to 80% by weight, (c) shaping and drying the highly concentrated acrylic acid polymer solution.

Described herein is a process for preparing solid acrylic acid polymers including: (a) preparing an aqueous acrylic acid polymer solution having a solids content of 30% to 70% by weight by free-radical polymerization, (b) neutralizing the aqueous acrylic acid polymer solution at least partly by adding a base, which results in release of a heat of neutralization, and concentrating the aqueous acrylic acid polymer solution by exploiting the heat of neutralization to give a highly concentrated acrylic acid polymer solution having a solids content of 60% to 80% by weight, (c) shaping and drying the highly concentrated acrylic acid polymer solution.

Methods for simultaneously determining the concentrations of transition metal compounds in solutions containing two or more transition metal compounds are described. Polymerization reactor systems providing real-time monitoring and control of the concentrations of the transition metal components of a multicomponent catalyst system are disclosed, as well as methods for operating such polymerization reactor systems, and for improving methods of preparing the multicomponent catalyst system.

Methods for simultaneously determining the concentrations of transition metal compounds in solutions containing two or more transition metal compounds are described. Polymerization reactor systems providing real-time monitoring and control of the concentrations of the transition metal components of a multicomponent catalyst system are disclosed, as well as methods for operating such polymerization reactor systems, and for improving methods of preparing the multicomponent catalyst system.

This disclosure describes polymerization processes and processes for quenching polymerization reactions using reactive particulates, such as lecithin, as quenching agents, typically in solution or bulk polymerization processes.