US 11,883,925 B2
Polishing pad and method for manufacturing same
Ryuma Matsuoka, Saijo (JP); Hiroshi Kurihara, Saijo (JP); Satsuki Narushima, Saijo (JP); and Yamato Takamizawa, Saijo (JP)
Assigned to FUJIBO HOLDINGS, INC., Tokyo (JP)
Appl. No. 17/040,638
Filed by Fujibo Holdings, Inc., Tokyo (JP)
PCT Filed Mar. 19, 2019, PCT No. PCT/JP2019/011405
§ 371(c)(1), (2) Date Sep. 23, 2020,
PCT Pub. No. WO2019/188577, PCT Pub. Date Oct. 3, 2019.
Claims priority of application No. 2018-066808 (JP), filed on Mar. 30, 2018.
Prior Publication US 2021/0114166 A1, Apr. 22, 2021
Int. Cl. B24B 37/24 (2012.01)
CPC B24B 37/24 (2013.01) 15 Claims
OG exemplary drawing
 
1. A polishing pad comprising a polishing layer including a polyurethane sheet, wherein a rate of change in a tan δ peak value calculated in accordance with the following equation between a loss tangent tan δ peak value (a tan δ peakwet) within a temperature range of 20° C. to 100° C. of the polyurethane sheet in a wet state after immersion in a water bath for 3 days in a tensile mode with an initial load of 148 g, a strain range of 0.1%, and a measurement frequency of 1.6 Hz, and a loss tangent tan δ peak value (a tan δ peakdry) within a temperature range of 20° C. to 100° C. of the polyurethane sheet in a dry state without immersion in the water bath in a tensile mode with an initial load of 148 g, a strain range of 0.1%, and a measurement frequency of 1.6 Hz is 15% or less:
Rate of change in tan δ peak value=|tan δ peakwet−tan δ peakdry|/tan δ peakdry×100.