Metatitanic acid particles have absorption at wavelengths of 450 nm and 750 nm in a visible absorption spectrum, have a surface to which a metal compound having a metal atom and a carbon atom is bonded through an oxygen atom, and satisfy the following inequality: 0.03A0.3, wherein A represents a value of {(peak intensity of CO bond+peak intensity of CO bond)/(peak intensity of CC bond+peak intensity of CC bond} in a C 1s XPS spectrum.

The present invention relates to a transition metal-based heterogeneous carbonylation reaction catalyst that has an excellent catalytic activity and selectivity in the carbonylation reaction and is easily separated from a product, by crosslinking polymerizing a transition metal-based homogeneous catalyst unit through a Friedel-Craft reaction; and a method for preparing lactone using the same. The transition metal-based heterogeneous carbonylation reaction catalyst allows to produce lactone or succinic anhydride with an epoxide compound while showing a high selectivity, and can be applied in industrial very usefully due to easy separation from the product and thus reusing thereof.

The present invention provides a curing catalyst for an organic polymer or an organopolysiloxane, which has a high safety and a practical curing speed, and improves the adhesion of a cured product to a substrate, and can be produced at low cost.

An aspect of the present invention provides a curing catalyst [B] for an organic polymer or an organopolysiloxane, which is used for curing an organic polymer [A1] or an organopolysiloxane [A2] having a reactive hydrolyzable silicon-containing group, wherein the catalyst [B] contains a titanium compound [B1] represented by the following formula and a secondary amine compound or a tertiary amine compound [B2].

(R.sup.1O).sub.nTi-A.sub.4-n

(In the formula, R.sup.1 is a hydrocarbon group having 1 to 10 carbon atoms, and A is a carboxylic acid residue, and n is 1 or 2.)

A process for the transesterification of methyl-2-ethylhexanoate with triethylene glycol to produce triethylene glycol di-2-ethylhexanoate is provided. In the process, methyl-2-ethylhexanoate is combined with triethylene glycol to form a first mixture. The first mixture is heated in the presence of a catalyst to form a second mixture comprising methanol and triethylene glycol di-2-ethylhexanoate. Methanol is separated from the second mixture to yield triethylene glycol di-2-ethylhexanoate. Na.sub.2CO.sub.3, Cs.sub.2CO.sub.3, K.sub.2CO.sub.3, Rb.sub.2CO.sub.3, sodium methoxide or titanium isopropoxide are suitable catalysts.

The invention relates to a method for preparing a silane-terminated polymer by reacting a polyol A) with a diisocyanate B), an isocyanatosilane C) and an amino silane E), wherein the polyol component A) is reacted simultaneously with a mixture of at least one diisocyanate B) and one isocyanatosilane C), and the resulting product is subsequently reacted with the amino silane E) to produce the silane-terminated polymer. The method according to the invention can be used to prepare mixed silane-terminated polymers having a low viscosity.

The present disclosure relates to a method and a system for manufacturing an ester-based composition which are characterized in sequentially operating a plurality of batch reactors, and since an ester-based composition is semi-continuously manufactured, the productivity is high and the stability of a batch reactor is secured.

The present invention relates to Ziegler-Natta catalyst components for olefin polymerization employing specific carbonate compounds as an element of solid catalyst composition in conjunction with at least one or more internal donor compounds, for producing polyolefins, particularly polypropylene and ethylene-propylene block co-polymer, which exhibits substantially high rubber content with higher stereo-regularity and hydrogen response.

A 3D structure of the graphite-titanium-nanocomposite complex and a method of preparing the graphite-titanium-nanocomposite complex are disclosed. The Graphite-titanium-nanocomposite complex includes a metal core associated with the two phases, amine functionalized graphite, and amine functionalized titanium. The method of preparation includes amine functionalizing of graphite and titanium with coupling agents to produce amine functionalized titanium and graphite, further mixing with a metal ion solution for synthesizing an ion complex. Trisodium citrate solution and sodium borohydride solution is added to the ion complex to prepare a 3D structure of the graphite-titanium-nanocomposite complex, employed as a catalyst.

The present invention relates to the field of polymerisation catalysts, and systems comprising these catalysts for polymerising carbon dioxide and an epoxide, a lactide and/or lactone, and/or an epoxide and an anhydride. The catalyst is of formula (I): ##STR00001##
wherein at least one of M.sub.1 or M.sub.2 is selected from Ni(II) and Ni(III)-X. A process for the reaction of carbon dioxide with an epoxide; an epoxide and an anhydride; and/or a lactide and/or a lactone in the presence of the catalyst is also described.

The present invention is directed at stabilization of aqueous urea solutions containing organometallic catalyst precursors. Stabilization can be achieved by monitoring and controlling the solution pH.