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US 12,215,217 B2Granted
Composition for acoustic member and acoustic member
AssigneeYamaha Corporation
InventorTomoya Miyata
Life of this patent
Estimating the term…
Abstract
A composition for an acoustic member includes a non-diene butyl rubber, and a liquid polymer having a molecular weight of 1,000 to 120,000. A difference in an SP value between the liquid polymer and the butyl rubber is within ±0.5.
Claims9
A composition for an acoustic member comprising:
- a non-diene butyl rubber;
- and
- a liquid polymer,
- an internal loss (tan δ) in a dynamic viscoelasticity measurement of a first crosslinked product of the composition measured under conditions of 20° C., 0.1% dynamic strain, and 1 Hz frequency being increased by 120% or more as compared with a second crosslinked product formed by removing the liquid polymer from the composition, and A hardness of the first crosslinked product according to JIS K6253 being 60% or more and 90% or less of A hardness of the second crosslinked product, and
- a rate of change of the A hardness of the first crosslinked product being less than 10% before and after holding at 110° C. for 300 hours.
2 more elements
A composition for an acoustic member comprising:
- a non-diene butyl rubber;
- and
- a liquid polymer having a molecular weight of 1,000 to 120,000,
- a difference in an SP value between the liquid polymer and the butyl rubber being within ±0.5, and
- a rate of change of A hardness according to JIS K6253 for a first crosslinked product of the composition being less than 10% before and after holding at 110° C. for 300 hours.
2 more elements
Dependencies are inferred from the claim text.