The object of the present invention is to provide a method for producing a thermally expandable base material for vehicle interior enabling production of an interior material for vehicle that is lightweight and has sufficient sound-absorbing properties, high stiffness and the like, and a method for producing a base material for vehicle interior. The present method for producing a thermally expandable base material for vehicle interior is characterized by comprising: mixing a synthetic resin emulsion, a thermally expandable microcapsule emulsion, and a resin-based adhesive emulsion; impregnating an inorganic fiber mat with the emulsion mixture; drying the mat at a temperature lower than a thermal expansion starting point of the thermally expandable microcapsule; heating the mat at a temperature at which a synthetic resin powder melts and which is lower than the thermal expansion starting point of the thermally expandable microcapsule; hot-pressing and cooling the mat. The present method for producing a base material for vehicle interior is characterized by comprising: heating the thermally expandable base material for vehicle interior at a temperature higher than the thermal expansion starting point of the thermally expandable microcapsule to thermally expand.

Claims data not available