Disclosed are an aqueous pigment dispersion containing at least a pigment, water, a high-molecular dispersant, and an alkali. The high-molecular dispersant is a diblock polymer having a formula (1) of A-B or a triblock polymer having a formula (2) of A-B-C. The diblock or triblock polymer is a diblock or triblock polymer obtained by polymerizing addition-polymerizable monomers with a radical generator while using an organic iodide as a polymerization initiating compound and an organic phosphorus compound, organic nitrogen compound or organic oxygen compound as a catalyst. Also disclosed are a production method and use of the aqueous pigment dispersion. With the high-molecular dispersant obtained by a simple living radical polymerization process free of the problems of conventional living radical polymerization and having a precisely-controlled molecular structure, the aqueous pigment dispersion can be obtained with the pigment dispersed in it.

Aqueous pigment dispersion and applications thereof

A highly active and environment-friendly catalyst for use in a living radical polymerization is provided. A catalyst for use in a living radical polymerization method is provided. The catalyst comprises a central element, which is selected from nitrogen and phosphorus, and at least one halogen atom, which is bound to the central element. A monomer having a radical reactive unsaturated bond is subjected to a radical polymerization reaction in the presence of the catalyst, thereby it is possible to obtain a polymer having narrow molecular weight distribution. The present invention has the merits such as low toxicity of the catalyst, a small amount of the catalyst being required, high solubility of the catalyst in the polymerization media, mild reaction conditions, no coloration, no odor (unnecessary post-treatment of molded products). The method of the present invention is more environment-friendly and economical than other living radical polymerization methods.

Novel living radical polymerization method using phosphorus compound or nitrogen compound as catalyst

Provided is a low-cost, highly active, environmentally friendly living radical polymerization catalyst which does not require a radical initiator. An organic compound having an oxidation-reduction capability is used as a catalyst. Even if a radical initiator is not used, a monomer can be subjected to a radical polymerization to obtain a polymer having narrow molecular weight distribution. The cost of the living radical polymerization can be remarkably reduced. It is made possible to prevent adverse effects of using a radical initiator. The present invention is significantly more environmentally friendly and economically excellent than conventional living radical polymerization methods, due to advantages of the catalyst such as low toxicity of the catalyst, low amount of the catalyst necessary, high solubility of the catalyst, mild reaction conditions, and no coloration/no odor (which do not require a post-treatment for a molded article), etc.

Catalyst for living radical polymerization and polymerization method

The effect of 2-Chloro-1,3,2-dioxaphospholane on the AIBN initiated polymerisation of acrylo — nitrile , methyl methacrylate and styrene was investigated kinetically in benzene at 60 – 80°C. With acrylonitrile normal kinetic orders with respect to monomer and AIBN could be observed with the phospholane behaving as a chain transfer agent. With methyl methacrylate and styrene it was observed that the phospholane causes enhancement of the rates due to concurrent radical and ionic polymerisation besides functioning as a chain transfer agent.

Effect of 2-Chloro-1,3,2-dioxaphospholane on the radical polymerisation of acrylonitrile, styrene and methyl methacrylate

2-Chloro-1,3,2-dioxaphosphorinane-2-oxide, -sulfide, and -selenide are studied at the DFT/B3LYP level and several ab initio methods using a 6-311G** basis set. Our energy optimizations by all these methods show that for oxide DFT and ab initio methods are not much different, while for the sulfide and the selenide the DFT relative energies are higher by about a kcal/mol as compared to those of MP2, MP3, MP4(SDTQ)//MP2, and CCSD(T)//MP2 (//MP2 indicates that a single-point calculation based on the MP2 optimized geometry is performed). However, regardless of rather large relative energies, that does not change the fact that in all three cases the conformational equilibrium mixture contains more than 95% of the lowest, chair-equatorial conformer (this indicates that the P=X bond is in equatorial position). This one and the next higher conformer (chair-axial) are confirmed to be real conformers (energy minima) in all cases. The energetically much higher twist and boat forms are probably just stationary states and local maxima because in many cases, geometry optimizations do not converge to them. Only for MP2 and the selenide do all optimizations converge to the desired stationary state. The relative energies could all be explained in terms of anomeric effects and ring strains. The decreasing covalent character of the P=X bond, with X changing from O to S and to Se, shows itself in the increasing bond lengths and the decreasing strength of anomeric effects.

Anomeric effect and theoretical vibrational spectra compared to the experiment in 2-chloro-1,3,2-dioxaphosphorinane-2-oxide, -sulfide, and -selenide. I. Anomeric effect and structures

The effects of C6H5PCl2, POCl3, and PCl3 on the free radical polymerisation of acrylonitrile initiated bya,a′-azobisisobutyronitrile were kinetically investigated in benzene and trichloroethylene solutions. With PCl3 rates of polymerisation were unaffected but the degrees of polymerisation were found to decrease with increasing PCl3. With C6H5PCl2 and POCl3 however both rates and degrees of polymerisation were adversely affected. Thus PCl3 acts as a chain transfer agent while the other two phosphorous compounds function as degradative chain transfer agents.

Effects of phosphorous oxychloride, phosphorous trichloride and dichlorophenylphosphine on the radical polymerisation of acrylonitrile under heterogeneous conditions

D. V. P. R. Vara Prasad

Papers

Effects of phosphorous oxychloride, phosphorous trichloride and dichlorophenylphosphine on the radical polymerisation of acrylonitrile under heterogeneous conditions

Effect of 2-Chloro-1,3,2-dioxaphospholane on the radical polymerisation of acrylonitrile, styrene and methyl methacrylate

Redox polymerization of acrylamide initiated by the system V(III)(acac)3 hydroxylamine in dimethyl formamide