A process for preparing a polyester-modified silicone resin comprises mixing an alkoxysilane and/or its hydrolyzate, i.e. an alkoxysiloxane, and a polyester resin having at least two hydroxyl groups in the molecule, and subjecting the mixture to hydrolysis and polycondensation reactions in the presence of an acid catalyst. This process is performed by a continuous one-stage reaction sequence including hydrolysis, polycondensation and modification and is simplified. A composition comprising the polyester-modified silicone resin is also described. The composition comprising organozinc compounds along with the modified silicone resin is significantly improved in heat resistance and color-difference.
Disclosed is an alkoxysilane/organic polymer composition for use in producing an insulating thin film, comprising (A) a specific alkoxysilane; (B) a specific organic polymer; and (C) a solvent for alkoxysilane (A) and organic polymer (B), wherein solvent (C) comprises at least one organic solvent selected from the group consisting of amide linkage-containing organic solvents and ester linkage-containing organic solvents. Also disclosed are a silica-organic polymer composite thin film which is produced by a process comprising: forming a thin film of the composition of the present invention; subjecting the thin film to a hydrolysis and dehydration-condensation reaction with respect to the alkoxysilane thereof, to thereby cause the alkoxysilane to be gelled in the thin film; and removing the solvent remaining in the thin film by drying, and a porous silica thin film which is obtained by removing the organic polymer from the silica-organic polymer composite thin film. Both of the silica-organic polymer composite thin film and the porous silica thin film have advantages not only in that these thin films have a low dielectric constant suitable for insulating layers for a multilevel interconnect for a semiconductor device, but also in that these thin films can be produced by a method which can be easily performed in the current process for producing a semiconductor device.
The invention provides for the use of silicone resins obtainable by reacting a) an alkoxysiloxane of the general formula .times..function..times. ##EQU00001## with b) one or more hydroxyl-containing polyesters, and if desired c) one or more low molecular weight alcohols, it being possible for the alkoxysilane to be reacted partially and completely, based on the amount of (OR.sup.1) groups in a), but the reaction being taken at least to the point where a clear solution is obtained, as dispersants for solids for producing coatings, printing inks and/or print varnishes.
