Resin particles and method for manufacturing resin particles

1. Resin particles comprising:

resin base particles; and

silica particles on surfaces of the resin base particles, the silica particles containing a quaternary ammonium salt and having hydrophobized surfaces,

wherein a difference (detection temperature A−detection temperature B) between a detection temperature A and a detection temperature B is more than 50° C., where the detection temperature A is a detection temperature from a pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles before cleaning, and the detection temperature B is a detection temperature from the pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles after cleaning.

2. Resin particles comprising:

resin base particles; and

silica particles on surfaces of the resin base particles, the silica particles containing a quaternary ammonium salt and having hydrophobized surfaces,

wherein a ratio (F BEFORE /F AFTER ) between maximum frequencies of pore diameters of 2 nm or less in the silica particles is 0.9 or more and 1.1 or less, and a ratio (F SINTERING /F BEFORE ) between maximum frequencies of pore diameters of 2 nm or less in the silica particles is 5 or more and 20 or less,

F BEFORE : a maximum frequency of pore diameters of 2 nm or less in the silica particles before cleaning determined from a pore diameter distribution curve in nitrogen gas adsorption analysis,

F AFTER : a maximum frequency of pore diameters of 2 nm or less in the silica particles after cleaning determined from a pore diameter distribution curve in nitrogen gas adsorption analysis, and

F SINTERING : a maximum frequency of pore diameters of 2 nm or less in the silica particles before cleaning and after sintering at 700° C. determined from a pore diameter distribution curve in nitrogen gas adsorption analysis.

3. The resin particles according to claim 1 , wherein the quaternary ammonium salt includes a compound represented by general formula (AM) below:

where R 1 , R 2 , R 3 , and R 4 each independently represent an optionally substituted alkyl group, aralkyl group, or aryl group, and X represents an anion, and where two or more of R 1 , R 2 , R 3 , and R 4 are optionally bonded to each other to form a ring.

4. The resin particles according to claim 2 , wherein the quaternary ammonium salt includes a compound represented by general formula (AM) below:

where R 1 , R 2 , R 3 , and R 4 each independently represent an optionally substituted alkyl group, aralkyl group, or aryl group, and X represents an anion, and where two or more of R 1 , R 2 , R 3 , and R 4 are optionally bonded to each other to form a ring.

5. The resin particles according to claim 1 , wherein the silica particles have a number-average particle diameter D50p of 5 nm or more and 200 nm or less.

6. The resin particles according to claim 2 , wherein the silica particles have a number-average particle diameter D50p of 5 nm or more and 200 nm or less.

7. The resin particles according to claim 3 , wherein the silica particles have a number-average particle diameter D50p of 5 nm or more and 200 nm or less.

8. The resin particles according to claim 4 , wherein the silica particles have a number-average particle diameter D50p of 5 nm or more and 200 nm or less.

9. The resin particles according to claim 5 , wherein the silica particles have a number-average particle diameter D50p of 5 nm or more and 100 nm or less.

10. The resin particles according to claim 6 , wherein the silica particles have a number-average particle diameter D50p of 5 nm or more and 100 nm or less.

11. The resin particles according to claim 1 , wherein a proportion (N/silica particles×100) of an amount N of nitrogen element in the silica particles detected by oxygen-nitrogen analysis is 0.01 or more and 1.0 or less.

12. The resin particles according to claim 1 , wherein the silica particles have an average pore diameter of 0.55 nm or more and 2.00 nm or less.

13. The resin particles according to claim 1 , wherein a ratio (C AFTER /C BEFORE ) between electrostatic capacitances of the resin particles is 1.5 or less,

C BEFORE : an electrostatic capacitance of the resin particles before cleaning separated from a mixture formed by mixing the resin particles before cleaning and glass particles under particular conditions, and

C AFTER : an electrostatic capacitance of the resin particles after cleaning separated from a mixture formed by mixing the resin particles after cleaning and glass particles under particular conditions,

wherein the particular conditions include a mass ratio of resin particles/glass particles of 1/10 and a mixer used for mixing is a Henschel Mixer at a mixing time of 5 minutes at a mixing temperature of 10° C. and a mixing speed of 49 rpm.

14. The resin particles according to claim 1 , wherein the silica particles further contain aluminum atoms.

15. The resin particles according to claim 14 , wherein the silica particles containing aluminum atoms are silica particles having surfaces treated with an aluminum compound.

16. The resin particles according to claim 14 , wherein, in the silica particles containing aluminum atoms, a ratio (Si/Al) of an amount Si of silicon element detected by X-ray photoelectron spectroscopy to an amount Al of aluminum element detected by X-ray photoelectron spectroscopy is 0.01 or more and 0.30 or less.

17. The resin particles according to claim 1 , wherein the resin base particles have a volume-average particle diameter D50v of 1 μm or more and 40 μm or less.

18. The resin particles according to claim 1 , wherein the resin base particles contain at least one of vinyl resins and polycondensation resins.

19. The resin particles according to claim 1 , wherein the difference (detection temperature A−detection temperature B) between the detection temperature A and the detection temperature B is 60° C. or more and 120° C. or less.