Thermally expandable sheet production method and shaped object production method

A shaped object production method comprising:

• preparing a medium comprising a base and a thermally expansive layer formed on the base, wherein the thermally expansive layer is configured to expand with heating;
• forming a pattern layer on the medium using a predetermined material so that at least a portion of the thermally expansive layer expands when a predetermined energy is provided;
• and
• providing the predetermined energy to the medium on which the pattern layer is formed, to cause expansion of the portion of the thermally expansive layer and to form unevenness on a surface of the medium,
• wherein the thermally expansive layer comprises:
• a first layer formed on the base and comprising a first thermally expandable material and a first binder, the first layer having a first ratio of the first thermally expandable material with respect to the first binder;
• and
• a second layer formed on the first layer and comprising a second thermally expandable material and a second binder, the second layer having a second ratio of the second thermally expandable material with respect to the second binder, wherein the first ratio is lower than the second ratio, and
• wherein by having the first ratio lower than the second ratio, the first layer serves as a peel-off suppressing layer for suppressing peel-off of the thermally expansive layer from the base when the unevenness is formed in the forming.

A shaped object production method comprising:

• preparing a medium comprising a base and a thermally expansive layer formed on the base, wherein the thermally expansive layer is configured to expand with heating;
• and
• applying heat to at least a portion of the medium with a temperature to cause expansion of the thermally expansive layer and rising of a surface of the medium and to form unevenness on the surface of the medium, the temperature being a temperature that causes the thermally expansive layer to expand, the surface corresponding to the portion of the medium to which the heat is applied,
• wherein the thermally expansive layer comprises:
• a first layer formed on the base and comprising a first thermally expandable material and a first binder, the first layer having a first ratio of the first thermally expandable material with respect to the first binder;
• and
• a second layer formed on the first layer and comprising a second thermally expandable material and a second binder, the second layer having a second ratio of the second thermally expandable material with respect to the second binder, wherein the first ratio is lower than the second ratio, and
• wherein by having the first ratio lower than the second ratio, the first layer serves as a peel-off suppressing layer for suppressing peel-off of the thermally expansive layer from the base when the unevenness is formed in the forming.