| 摘要 |
PROBLEM TO BE SOLVED: To obtain a sound absorbing film having an effective sound absorbing property in the low frequency region by forming a polymer material having a specific storage elastic modulus in tension and loss tangent into a film. SOLUTION: One to three hundreds pts.wt. of, preferably 1-200 pts.wt. of, at least one plasticizer selected from compounds of formulae I-III (wherein R1 to R3 are each a 3-15C monocyclic hydrocarbon; R4 is a 1-6C alkyl; and R5 to R7 are each an aromatic monocyclic hydrocarbon) is blended with 100 pts.wt. of a polyvinyl chloride-based polymer with a degree of polymerization of 300-4,000 to obtain a polymer material having a storage elastic modulus in tension of 2.0×10<7> Pa or below and a loss tangent of 0.50 or above in a linear viscoelasticity measurement at 23 deg.C. Subsequently, the polymer material is formed into a film to obtain a sound absorbing film with a thickness of 200μm or lower. The sound absorbing film is laminated to a sound absorbing material such as a natural fiber, a synthetic fiber, felt made of a glass fiber and the like, non woven fabric, woven fabric, a fiber aggregate, a cellular material and the like to obtain a sound absorbing laminate.
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