▎ 摘　　要

NOVELTY - Diaphragm of sounding device, comprises silicone rubber film layer, the silicon rubber film layer contains a network polymer, and the network polymer comprises a first segment, a second segment and/or a third segment. The first segment is silicon based compound (I), the second segment is methyl group containing compound (II) and the third segment is 3-methylhex-3-ene (III). USE - Used as diaphragm of sounding device. ADVANTAGE - The diaphragm: has second chain segment, and since the C-C main chain density of the second chain segment is small, the diaphragm containing second chain segment has low density, high tensile strength and high sounding sensitivity. DETAILED DESCRIPTION - Diaphragm of sounding device, comprises silicone rubber film layer, the silicon rubber film layer contains a network polymer, and the network polymer comprises a first segment, a second segment and/or a third segment. The first segment is silicon based compound of formula (I), the second segment is methyl group containing compound of formula (II) and the third segment is 3-methylhex-3-ene of formula (III). R1= methyl, ethyl, trifluoropropyl or phenyl; R2= hydrogen, methyl, ethyl, trifluoropropyl or phenyl; R3= H, CH3or (CH2)5CH3; and R4= H, CH3or (CH2)5CH3. INDEPENDENT CLAIMS are also included for: 1. method for preparing diaphragm of sounding device, comprising adding filler, olefin copolymer and auxiliary agent into silicone rubber base polymer, then mixing to obtain mixed material, and molding the mixed material to obtain silicone rubber film layer of vibrating film; 2. sounding device, comprising a vibration system and a magnetic circuit system matched with the vibration system, the vibration system includes a diaphragm and a voice coil combined on one side of the diaphragm, and the magnetic circuit system drives the voice coil to vibrate to drive the diaphragm to produce sound, and diaphragm is diaphragm of sounding device; and 3. sounding device, comprising a casing, a magnetic circuit system and a vibration system arranged in the casing, the vibration system includes a voice coil, a first diaphragm and a second diaphragm, the top of the voice coil is connected to the first diaphragm, the magnetic circuit system drives the voice coil to vibrate to drive the first diaphragm to produce sound, the two ends of the second diaphragm are respectively connected to the bottom of the casing and the voice coil, and second diaphragm is diaphragm of sounding device. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the diaphragm of sounding device.