Heat insulating panels are widely used in various domains, for example construction sites or hospitals. These panels require adhesives which may generate heat when the panels are subjected to high temperatures. In the field of high temperature insulation, ceramics are brittle and may not be suitable in some applications. This invention discloses a heat-insulating composite including a plurality of glass, and a binder composition for fusing the glass when the heat-insulting composite is exposed to a temperature higher than 1000C. It was found that as the heat progresses from the outer surface to the inner surface of the composite, plurality of laminated ceramic-like structures are formed, which may assist further in insulating the heat. Interestingly, these laminated ceramic-like structures are found to be rubber-like and therefore not brittle.