An isocyanate group-containing organosilicon compound shown by the following general formula (1), and having three or more R.sup.2 groups per molecule and a viscosity at 25° C. of 100 mm.sup.2/s or less. This provides an organosilicon compound which has three or more isocyanate groups per molecule, and which is suitable as a crosslinking agent, low in viscosity, and excellent in handleability. R.sup.1.sub.aR.sup.2.sub.bSiO.sub.(4−a−b)/2 (1), where each R.sup.1 is identical to or different from one another, represents a monovalent alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group, a monovalent aryl group having 6 to 10 carbon atoms, or a monovalent aralkyl group having 7 to 10 carbon atoms, and has no aliphatic unsaturated group; and R.sup.2 represents an organic group shown by a formula —CH.sub.2CH.sub.2Si(CH.sub.3).sub.2OSi(CH.sub.3).sub.2CH.sub.2CH.sub.2CH.sub.2NCO.

Nanoparticles that can be used as hydrosilylation and dehydrogenative silylation catalysts. The nanoparticles have at least one transition metal with an oxidation state of 0, chosen from the metals of columns 8, 9 and 10 of the periodic table, and at least one carbonyl ligand, preferably a silicide.

A hydrosilylation reaction catalyst prepared from: a catalyst precursor comprising a transition metal compound, excluding platinum, belonging to group 8-10 of the periodic table, e.g., iron acetate, cobalt acetate, nickel acetate, etc.; and a ligand comprising an isocyanide compound such as t-butyl isocyanide. The hydrosilylation reaction catalyst has excellent handling and storage properties. As a result of using this catalyst, a hydrosilylation reaction can be promoted under gentle conditions.

A hydrosilylation reaction catalyst prepared from: a catalyst precursor comprising a transition metal compound, excluding platinum, belonging to group 8-10 of the periodic table, e.g., iron acetate, cobalt acetate, nickel acetate, etc.; and a ligand comprising a carbine compound such as 1,3-dimesitylimidazol-2-ylidene, etc. The hydrosilylation reaction catalyst has excellent handling and storage properties. As a result of using this catalyst, a hydrosilylation reaction can be promoted under gentle conditions.

A hydrosilylation iron catalyst prepared from a two-electron ligand (L) and a mononuclear, binuclear, or trinuclear complex of iron indicated by formula (1), Fe having bonds with carbon atoms included in X and the total number of Fe-carbon bonds being 2-10. As a result of using iron, the hydrosilylation iron catalyst is advantageous from a cost perspective as well as being easily synthesized. Hydrosilylation reactions can be promoted under mild conditions by using this catalyst.

Fe(X).sub.a  (1)

(in the formula, each X independently indicates a C2-30 ligand that may include an unsaturated group excluding carbonyl groups (CO groups) and cyclopentadienyl groups, however at least one X includes an unsaturated group, a indicates an integer of 2-4 per Fe atom.)

Nanoparticles that can be used as hydrosilylation and dehydrogenative silylation catalysts. The nanoparticles have at least one transition metal with an oxidation state of 0, chosen from the metals of columns 8, 9 and 10 of the periodic table, and at least one carbonyl ligand, preferably a silicide.

A method for producing a hydroxyl-functionalized polysiloxane having secondary or tertiary hydroxyl groups, said method comprising the steps of: i) reacting a hydroxyalkyl allyl ether having a secondary or tertiary alcohol group with a siloxane under anhydrous conditions and under transition metal catalysis, said hydroxylalkyl allyl ether conforming to Formula (I) ##STR00001## wherein n is 0, 1, 2, 3, 4 or 5, preferably 0; m is 1, 2, 3, 4 or 5, preferably 1; spacer group A is constituted by a covalent bond or a C.sub.1-C.sub.20 alkylene group; R.sup.1 is hydrogen, a C.sub.1-C.sub.8 alkyl group, a C.sub.3-C.sub.10 cycloalkyl group, a C.sub.6-C.sub.18 aryl group or an aralkyl group; R.sup.a, R.sup.b, R.sup.c, R.sup.d, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 may be the same or different and each is independently selected from hydrogen, a C.sub.1-C.sub.8 alkyl group, a C.sub.6-C.sub.18 aryl group or a C.sub.6-C.sub.18 aralkyl group, with the proviso that at least one of R.sup.3 and R.sup.4 is not hydrogen; and said siloxane conforming to Formula (II) ##STR00002## wherein m is 1, 2, 3, 4 or 5, preferably 1; R.sup.6, R.sup.7, R.sup.8 and R.sup.9 may be the same or different and each represent a C.sub.1-C.sub.8 alkyl group, a C.sub.3-C.sub.10 cycloalkyl group, a C.sub.6-C.sub.18 aryl group or a C.sub.6-C.sub.18 aralkyl group; and ii) in the presence of the reaction product of step i), performing a ring opening polymerization of at least one cyclic siloxane monomer.

A mixture M includes at least one compound A, selected from (a1) a compound of the general formula (I) and/or (a2) a compound of the general formula (I′), at least one compound B, selected from (b1) a compound of the general formula (II) and/or (b2) a compound of the general formula (II′) and/or (b3) a compound of the general formula (II″), and at least one compound C, selected from cationic germanium(II) compounds of the general formula (III).

The present invention relates to a composition comprising an aqueous dispersion of acrylate-siloxane copolymer particles comprising structural units of an acrylate monomer; an acid monomer; and a siloxane acrylate monomer of formula I:

##STR00001##

where R, R.sup.1, R.sup.2, Y and x are as defined herein. The composition has a high solids content, a low concentration of siloxane acrylate monomer and low coagulum levels. The composition is useful for forming coatings with improved hydrophobicity, stain resistance, and aesthetic/haptic properties compared with conventional all-acrylic compositions.

The present invention relates to a method for preparing an aqueous dispersion of acrylate-siloxane copolymer particles as described herein. The polymer particles comprise structural units of an acrylate monomer; an acid monomer; and a siloxane acrylate monomer of formula I:

##STR00001##

where R, R.sup.1, R.sup.2, Y and x are as defined herein. The method provides an efficient way to prepare a high solids content aqueous dispersion of siloxane-acrylate hybrid copolymers with efficient incorporation of siloxane acrylate monomers, low residual monomer, and low generation of unwanted coagulum. The dispersion is useful for forming coatings with improved hydrophobicity, stain resistance, and aesthetic/haptic properties compared with conventional all-acrylic compositions.