Patent ID: 7728095

Claim:
A process for producing an organic-inorganic hybrid glassy material, comprising the sequential steps of: (a) concentrating a starting sol of an organic-inorganic hybrid glassy material, thereby yielding a precursor material having meltability; (b) melting the precursor material; (c) subjecting a product of the step (b) to a heating treatment under reduced pressure; and (d) subjecting a product of the step (c) to a high-temperature heat treatment at 300° C. or higher; wherein: step (d) is not conducted under reduced pressure and is carried out at a temperature higher than that of step (c), the precursor material of step (a) comprises a D unit in which, of the four bonds which can be made to a silicon atom, excluding two bonds to organic substituents, one or both of the remaining bonds is/are bonded to another silicon atom through an oxygen atom; and the process provides the organic-inorganic hybrid glassy material with a numeral ratio of (D 1 unit+T 2 unit) to (D 1 unit+D 2 unit+T 1 unit+T 2 unit+T 3 unit) of 0.10 or less; where: a T 1 unit is a unit in which, of the four bonds which can be made to a silicon atom, excluding one bond to an organic substituent, one of the remaining three bonds is bonded to a another silicon atom through an oxygen atom; a T 2 unit is a unit in which, of the four bonds which can be made to a silicon atom, excluding one bond to an organic substituent, two of the remaining three bonds are bonded to other silicon atoms through oxygen atoms; a T 3 unit is a unit in which, of the four bonds which can be made to a silicon atom, excluding one bond to an organic substituent, all three of the remaining three bonds are bonded to other silicon atoms through oxygen atoms; a D 1 unit is a unit in which, of the four bonds which can be made to a silicon atom, excluding two bonds to organic substituents, one of the remaining two bonds is bonded to another silicon atom through an oxygen atom, and a D 2 unit is a unit in which, of the four bonds which can be made to a silicon atom, excluding two bonds to organic substituents, both of the remaining two bonds are bonded to other silicon atoms through oxygen atoms.