Patent ID: 11958922
Assignee: SEKISUI PLASTICS CO., LTD.
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C | IPC C

Claim 8:
9. The vinyl-based resin particles according to claim 1, which have an Rsp value of 5 or more and 150 or less, wherein the Rsp value is represented by the following formula (1):

Rsp=(Rav−Rb)/Rb . . .  (1)

Rav: Reciprocal of average value of transverse relaxation time T2 (ms) obtained by the following measurement method 1
Rb: Reciprocal of transverse relaxation time T2 (ms) obtained by the following measurement method 2, Measurement method 1
A vinyl-based resin particle dispersion is obtained by mixing the vinyl-based resin particles and a first organic solvent in a mass ratio of 1:3, a polyimide precursor varnish is obtained by mixing the vinyl-based resin particle dispersion, a polyimide precursor solution with a solid concentration of 18±1 mass %, and a second organic solvent in a mass ratio of 6:3.61:1.8, the transverse relaxation time T2 (ms) of protons derived from the varnish is measured three times by the CPMG method using a hydrogen nucleus as a measurement nucleus at a measurement temperature of 20° C. at a resonance frequency of 13 MHz with a 90° pulse width of 5.81 μs to calculate an average value thereof, and the reciprocal of the average value is taken as Rav,, Measurement method 2
A blank solution is obtained by mixing the first organic solvent, a polyimide precursor solution with a solid concentration of 18±1 mass %, and the second organic solvent in a mass ratio of 4.5:3.61:1.8, the transverse relaxation time T2 (ms) of protons derived from the blank solution is measured three times by the CPMG method using a hydrogen nucleus as a measurement nucleus at a measurement temperature of 20° C. at a resonance frequency of 13 MHz with a 90° pulse width of 5.81 μs to calculate an average value thereof, and the reciprocal of the average value is taken as Rb.