Patent ID: 11912009
Assignee: ARCHEM INC.
Field: Surface technology, coating (Chemistry)
Classification: CPC B  G | IPC B  G

Claim 11:
12. A method of producing a sound insulation material, comprising
a first layer production step of obtaining a first layer constituted by a polyurethane foam,
a second layer preparation step of preparing a second layer constituted by a sheet-shaped member made from a material other than polyurethane,
a third layer production step of thermally compressing a polyurethane foam not thermally compressed, thereby obtaining a third layer, over its entirety, having a higher density than a density of any portion of the first layer obtained in the first layer production step, and
a lamination step of laminating the second layer prepared in the second layer preparation step, on a surface of the first layer obtained in the first layer production step, the surface being located on a first side, and laminating the third layer obtained in the third layer production step, on a surface of the second layer, the surface being located on the first side, thereby obtaining a laminated body,
wherein at least a portion of the first layer has a density of 15 kg/m3 or less,
the minimum value of the density of the third layer is 300 kg/m3 or more,
the second layer is constituted by a non-woven fabric, and
a thickness of at least a portion of the first layer is 10 to 50 times a maximum value of a thickness of the third layer.