| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the need for an adhesive layer, to make the diaphragm lightweight, and to improve the reproducibility by forming the diaphragm of a resin composition made of a specific polar organic solvent soluble aromatic polyamide resin and mica, and a coil. SOLUTION: This diaphragm 121 is composed of a vibration part 151, which is provided at a center part and vibrates to generate a sound and a reinforcement part 153 which is formed at the peripheral edge part and made thicker than the vibration part 151. In the reinforcement part 153, holes 155 and 157 are formed, and a land 131c formed at the external edge part of a coil 131 and a land 131d formed at the internal edge part of the coil 131 are exposed. The part of the diaphragm 121, except for the coil 131 consists of 95 to 65 vol.% polar organic solvent soluble aromatic polyamide resin represented by the formula and 5 to 35% mica of 1 to 500μm for grain size. In the formula, X stands for an oxygen atom, a sulfur atom, a sulphon group, etc., and (n) is an integer of 2 or larger.
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