A composition including: (A) a polymetalloxane having a repeating structure of a metal atom selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, In, Sn, Sb, Hf, Ta, W, and Bi and an oxygen atom; and (B) an aromatic polyfunctional amine compound.

A method for manufacturing a part made of composite material includes forming a ceramic matrix phase in pores of a fibrous preform by pyrolysis of a cross-linked copolymer ceramic precursor, the cross-linked copolymer including a first precursor macromolecular chain of a first ceramic having free carbon, and a second precursor macromolecular chain of a second ceramic having free silicon, the first macromolecular chain being bonded to the second macromolecular chain by cross-linking bridges including a bonding structure of formula *.sup.1—X—*.sup.2; in this formula, X designates boron or aluminium, -*.sup.1 designates the bond to the first macromolecular chain and -*.sup.2 the bond to the second macromolecular chain.

The present invention provides a barrier material formation composition comprising a silane oligomer, at least a part of the silane oligomer being modified with a metal alkoxide.

The present invention provides a barrier material formation composition comprising a silane oligomer, at least a part of the silane oligomer being modified with a metal alkoxide.

The present invention provides a polymer-based piezoelectric composite material from which a piezoelectric film capable of outputting a higher sound pressure is obtained in a case of using a piezoelectric speaker, a piezoelectric film formed of the polymer-based piezoelectric composite material, and a piezoelectric speaker and a flexible display which are formed of the piezoelectric film. The polymer-based piezoelectric composite material of the present invention is a polymer-based piezoelectric composite material including a polymer matrix which contains a polymer having a unit represented by Formula (1), and at least one unit selected from the group consisting of, a unit represented by Formula (2-1), a unit represented by Formula (2-2), and a unit represented by Formula (2-3), and piezoelectric particles.

(MO.sub.x/2)  Formula (1)

(R.sup.1SiO.sub.3/2)  Formula (2-1)

(R.sup.2.sub.2SiO.sub.2/2)  Formula (2-2)

(R.sup.3.sub.3SiO.sub.1/2)  Formula (2-3)

A method of producing a metal oxide fiber is described, including a spinning step of spinning a composition containing a polymetalloxane and an organic solvent to obtain a thread-like product; and a firing step of firing the thread-like product obtained in the spinning step at a temperature of 200° C. or higher and 2,000° C. or lower to obtain a metal oxide fiber, where the polymetalloxane has a repeating structure composed of a metal atom selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, Pd, Ag, In, Sn, Sb, Hf, Ta, W and Bi, and an oxygen atom and where the weight average molecular weight of the polymetalloxane is 20,000 or more and 2,000,000 or less.

A method of producing a metal oxide fiber is described, including a spinning step of spinning a composition containing a polymetalloxane and an organic solvent to obtain a thread-like product; and a firing step of firing the thread-like product obtained in the spinning step at a temperature of 200° C. or higher and 2,000° C. or lower to obtain a metal oxide fiber, where the polymetalloxane has a repeating structure composed of a metal atom selected from the group consisting of Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, Pd, Ag, In, Sn, Sb, Hf, Ta, W and Bi, and an oxygen atom and where the weight average molecular weight of the polymetalloxane is 20,000 or more and 2,000,000 or less.

A polymetalloxane including structural units represented by formulae (1-1) and (1-2), and having a weight-average molecular weight of 30,000 or more and 2,000,000 or less;

##STR00001## wherein, M.sup.1 and M.sup.2 independently represent different metal atoms; L.sup.1 and L.sup.2 are each independently a group selected from the group consisting of an allyloxy group, an aryloxy group, and a trialkylsiloxy group; L.sup.1 and L.sup.2 may be the same or different, and at least one thereof is an allyloxy group or an aryloxy group; R.sup.1 and R.sup.2 are each independently a hydrogen atom, a C.sub.1-12 alkyl group, or a group having a metalloxane bond; m is an integer that represents the valence of the metal atom M.sup.1, and a is an integer of 1 to (m2); and n is an integer that represents the valence of the metal atom M.sup.2, and b is an integer of 1 to (n2).

A polymetalloxane including structural units represented by formulae (1-1) and (1-2), and having a weight-average molecular weight of 30,000 or more and 2,000,000 or less;

##STR00001## wherein, M.sup.1 and M.sup.2 independently represent different metal atoms; L.sup.1 and L.sup.2 are each independently a group selected from the group consisting of an allyloxy group, an aryloxy group, and a trialkylsiloxy group; L.sup.1 and L.sup.2 may be the same or different, and at least one thereof is an allyloxy group or an aryloxy group; R.sup.1 and R.sup.2 are each independently a hydrogen atom, a C.sub.1-12 alkyl group, or a group having a metalloxane bond; m is an integer that represents the valence of the metal atom M.sup.1, and a is an integer of 1 to (m2); and n is an integer that represents the valence of the metal atom M.sup.2, and b is an integer of 1 to (n2).

An object of the invention is to provide a solid polyaluminoxane composition suitably used as a cocatalyst and a catalyst carrier in combination with an olefin oligomerization or polymerization catalyst, without the use of solid inorganic carriers such as silica. The solid polyaluminoxane composition of the invention includes a polyalkylaluminoxane and a trialkylaluminum, and has a solubility in n-hexane at 25 C. of less than 0.50 mol % as measured by a specific method (i), a solubility in toluene at 25 C. of less than 1.0 mol % as measured by a specific method (ii), and a 13 mol % or more molar fraction of alkyl groups derived from the trialkylaluminum moieties relative to the total number of moles of alkyl groups derived from the polyalkylaluminoxane moieties and the alkyl groups derived from the trialkylaluminum moieties as measured with respect to tetrahydrofuran-d.sub.8 soluble components by a specific method (iii).