METHOD OF MEASURING CONCENTRATION OF SILANOL GROUP AND CELL FOR MEASUREMENT

The object of the present invention is to measure the silanol group concentration in silicon compound, rapidly and at a high accuracy by infrared spectrophotometry. A silicon compound, when comes in contact with, for example, water in the air, reacts therewith immediately, forming a silanol group. Therefore, in measurement of the silanol group concentration in silicon compound, it is necessary that the sample to be measured is not contacted with the air and that the very small amount of water adhering to the inside of a sample cell is removed completely. In the present invention, the removal of water inside the cell in a short time has been made possible by use of a pressure-resistant cell. The first aspect of the present invention lies in: a method for measurement of silanol group concentration in silicon compound by infrared spectrophotometry, which comprises: conducting, prior to filling of a silicon compound in a cell, at least twice each of a step of keeping the cell inside at 20 Pa or lower and a step of keeping the cell inside at 0.2 to 1 MPa, then, introducing the silicon compound into the cell and measuring the infrared absorption spectrum thereof, to measure the concentration of the silanol group in the silicon compound. The second aspect of the present invention lies in: a cell used for measurement of infrared absorption spectrum, which can withstand a reduced pressure of 20 Pa or lower and a pressure of 0.2 to 1 MPa.