Claims
- 1. A toner for developing an electrostatic image, comprising a binder resin, and a magnetic material and/or a colorant, wherein
- the binder resin (a) comprises a styrene resin polymerized in the presence of a poly-functional polymerization initiator, (b) provides a molecular weight distribution on a GPC chromatogram showing a maximum (P1) in a molecular weight range of 3.5.times.10.sup.3 -5.times.10.sup.4 and a maximum (P2) or shoulder in a molecular weight range of at least 1.times.10.sup.5, and (c) contains 15 wt. % or less of a resin component in a molecular weight range of at most 3.times.10.sup.3, and
- the toner contains at most 100 ppm of styrene and benzaldehyde.
- 2. The toner according to claim 1, wherein the poly-functional polymerization initiator has three or more radical-generating functional groups.
- 3. The toner according to claim 1, wherein the poly-functional polymerization initiator has four or more radical-generating functional groups.
- 4. The toner according to claim 1, wherein the poly-functional polymerization initiator is a radical polymerization initiator selected from the group consisting of 1,4-bis(t-butylperoxycarbonyl)cyclohexane, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, and tris(t-butylperoxy)triazine.
- 5. The toner according to claim 1, wherein the binder resin contains 5-50 wt. % of a component in a molecular weight range of at least 1.times.10.sup.5.
- 6. The toner according to claim 1, wherein the binder resin contains 10-50 wt. % of a component in a molecular weight range of at least 1.times.10.sup.5.
- 7. The toner according to claim 1, wherein the binder resin provides a maximum (P1) in a molecular weight range of 5.times.10.sup.3 -5.times.10.sup.4.
- 8. The toner according to claim 1, wherein the binder resin contains at most 13 wt. % of the resin component in the molecular weight range of at most 3.times.10.sup.3.
- 9. The toner according to claim 1, wherein the binder resin contains at most 10 wt. % of the resin component in the molecular weight range of at most 3.times.10.sup.3.
- 10. The toner according to claim 1, wherein the binder resin contains a resin component obtained through polymerization in the presence of at least two polymerization initiators including a polymerization initiator A having a longer half-life .tau..sub.A and a polymerization initiator B having a shorter half-life .tau..sub.B providing a ratio .tau..sub.A /.tau..sub.B of at least 1.5.
- 11. The toner according to claim 1, wherein the binder resin comprises a mixture of a high-molecular weight styrene resin and a low-molecular weight vinyl resin.
- 12. The toner according to claim 11, wherein the high-molecular weight styrene resin has been obtained through polymerization in the presence of a poly-functional polymerization initiator.
- 13. The toner according to claim 11, wherein the high-molecular weight styrene resin comprises a styrene-acrylate copolymer obtained through polymerization in the presence of a poly-functional polymerization initiator.
- 14. The toner according to claim 11, wherein the high-molecular weight styrene resin comprises a styrene-methacrylate copolymer obtained through polymerization in the presence of a poly-functional polymerization initiator.
- 15. The toner according to claim 11, wherein the low-molecular weight vinyl resin comprises a styrene resin.
- 16. The toner according to claim 11, wherein the binder resin comprises 10-70 wt. parts of the high-molecular weight styrene resin and 90-30 wt. parts of the low-molecular weight vinyl resin.
- 17. The toner according to claim 11, wherein the binder resin comprises 20-60 wt. parts of the high-molecular weight styrene resin and 80-40 wt. parts of the low-molecular weight vinyl resin.
- 18. The toner according to claim 1, wherein the binder resin comprises a mixture of a high-molecular weight styrene resin providing a maximum in the molecular weight range of at least 1.times.10.sup.5 and obtained through polymerization in the presence of a poly-functional polymerization initiator, and a low-molecular weight vinyl resin providing a maximum in the molecular weight range of 3.5.times.10.sup.3 -5.times.10.sup.4 and obtained through polymerization in the presence of at least two polymerization initiators including a polymerization initiator A having a longer half-life .tau..sub.A and a polymerization initiator B having a shorter half-life .tau..sub.B providing a ratio .tau..sub.A /.tau..sub.B of at least 1.5.
- 19. The toner according to claim 18, wherein the high-molecular weight styrene resin has been obtained through polymerization in the presence of a poly-functional polymerization initiator in an amount of 0.01-5 wt. % of a polymerizable monomer providing the high-molecular weight styrene resin.
- 20. The toner according to claim 18, wherein the high-molecular weight styrene resin has been obtained through polymerization in the presence of a poly-functional polymerization initiator in an amount of 0.05-3 wt. % of a polymerizable monomer providing the high-molecular weight styrene resin.
- 21. The toner according to claim 18, wherein the low-molecular weight vinyl resin has been obtained through polymerization at a polymerization temperature of 75.degree.-145.degree. C. in the presence of a polymerization initiator B having a half-life .tau..sub.B at least 0.1 hour at the polymerization temperature.
- 22. The toner according to claim 18, wherein the low-molecular weight vinyl resin has been obtained through polymerization at a polymerization temperature of 75.degree.-145.degree. C. in the presence of a polymerization initiator B having a half-life .tau..sub.B 0.5-10 hours at the polymerization temperature.
- 23. The toner according to claim 10, wherein the ratio .tau..sub.A /.tau..sub.B at the polymerization temperature is 2 to 5000.
- 24. The toner according to claim 18, wherein the low-molecular weight vinyl resin has been obtained through polymerization at a polymerization temperature of 75.degree.-145.degree. C. in the presence of a polymerization initiator B having a half-life .tau..sub.B of 0.5-3 hours at the polymerization temperature, and a polymerization initiator A having a half-life .tau..sub.A of 2-60 hours at the polymerization initiator.
- 25. The toner according to claim 24, wherein the ratio .tau..sub.A /.tau..sub.B is 2 to 500.
- 26. The toner according to claim 18, wherein the low-molecular weight vinyl resin has been obtained through polymerization in the presence of the polymerization initiators A and B in a total amount of 0.1-5 wt. parts per 100 wt. parts of a polymerizable monomer providing the low-molecular weight vinyl resin.
- 27. The toner according to claim 26, wherein the polymerization initiators A and B are used in a weight ratio (A/B) of 0.01-100.
- 28. The toner according to claim 26, wherein the polymerization initiators A and B are used in a weight ratio (A/B) of 0.1-10.
- 29. The toner according to claim 1, wherein the benzaldehyde content in the toner is at most 10 ppm.
- 30. The toner according to claim 1, wherein the styrene content in the toner is at most 50 ppm.
- 31. The toner according to claim 1, further containing 0.5-10 wt. parts of a waxy substance per 100 wt. parts of the binder resin.
- 32. An image forming method, comprising:
- charging an electrostatic latent image-bearing member by abutting a charging member supplied with a voltage to the electrostatic latent image-bearing member;
- exposing the charged electrostatic image-bearing member to light to form an electrostatic latent image thereon;
- developing the electrostatic latent image with a toner to form a toner image thereon, the toner comprising a binder resin, and a magnetic material and/or a colorant, wherein
- the binder resin (a) comprises a styrene resin polymerized in the presence of a poly-functional polymerization initiator, (b) provides a molecular weight distribution on a GPC chromatogram showing a maximum (P1) in a molecular weight range of 3.5.times.10.sup.3 -5.times.10.sup.4 and a maximum (P2) or shoulder in a molecular weight range of at least 1.times.10.sup.5, and (c) contains 15 wt. % or less of a resin component in a molecular weight range of at most 3.times.10.sup.3, and
- the toner contains at most 100 ppm of styrene and benzaldehyde;
- transferring the toner image onto a transfer-receiving material while pressing the transfer-receiving material by a transfer member supplied with a voltage against the toner image, and
- fixing the toner image transferred to the transfer-receiving material onto the transfer-receiving material by a hot roller having a core metal thickness of at most 1 mm.
- 33. the image forming method according to claim 32, wherein the poly-functional polymerization initiator has three or more radical-generating functional groups.
- 34. The image forming method according to claim 32, wherein the poly-functional polymerization initiator has four or more radical-generating functional groups.
- 35. The image forming method according to claim 32, wherein the poly-functional polymerization initiator is a radical polymerization initiator selected from the group consisting of 1,4-bis(t-butylperoxycarbonyl)cyclohexane, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane and tris(t-butylperoxy)triazine.
- 36. The image forming method according to claim 32, wherein the binder resin contains 5-50 wt. % of a component in a molecular weight range of at least 1.times.10.sup.5.
- 37. The image forming method according to claim 32, wherein the binder resin contains 10-50 wt. % of a component in a molecular weight range of at least 1.times.10.sup.5.
- 38. The image forming method according to claim 32, wherein the binder resin provides a maximum (P1) in a molecular weight range of 5.times.10.sup.3 -5.times.10.sup.4.
- 39. The image forming method according to claim 32, wherein the binder resin contains at most 13 wt. % of the resin component in the molecular weight range of at most 3.times.10.sup.3.
- 40. The image forming method according to claim 32, wherein the binder resin contains at most 10 wt. % of the resin component in the molecular weight range of at most 3.times.10.sup.3.
- 41. The image forming method according to claim 32, wherein the binder resin contains a resin component obtained through polymerization in the presence of at least two polymerization initiators including a polymerization initiator A having a longer half-life t.sub.A and a polymerization initiator B having a shorter half-life t.sub.B providing a ratio t.sub.A /t.sub.B of at least 1.5.
- 42. The image forming method according to claim 32, wherein the binder resin comprises a mixture of a high-molecular weight styrene resin and a low-molecular weight vinyl resin.
- 43. The image forming method according to claim 42, wherein the high-molecular weight styrene resin has been obtained through polymerization in the presence of a poly-functional polymerization initiator.
- 44. The image forming method according to claim 42, wherein the high-molecular weight styrene resin comprises a styrene-acrylate copolymer obtained through polymerization in the presence of a poly-functional polymerization initiator.
- 45. The image forming method according to claim 42, wherein the high-molecular weight styrene resin comprises a styrene-methacrylate copolymer obtained through polymerization in the presence of a poly-functional polymerization initiator.
- 46. The image forming method according to claim 42, wherein the low-molecular weight vinyl resin comprises a styrene resin.
- 47. The image forming method according to claim 42, wherein the binder resin comprises 10-70 wt. parts of the high-molecular weight styrene resin and 90-30 wt. parts of the low-molecular weight vinyl resin.
- 48. The image forming method according to claim 42, wherein the binder resin comprises 20-60 wt. parts of the high-molecular weight styrene resin and 80-40 wt. parts of the low-molecular weight vinyl resin.
- 49. The image forming method according to claim 32, wherein the binder resin comprises a mixture of a high-molecular weight styrene resin providing a maximum in the molecular weight range of at least 1.times.10.sup.5 and obtained through polymerization in the presence of a poly-functional polymerization initiator and a low-molecular weight vinyl resin providing a maximum in the molecular weight range of 3.5.times.10.sup.3 -5.times.10.sup.4 and obtained through polymerization in the presence of at least two polymerization initiators including a polymerization initiator A having a longer half-life t.sub.A and a polymerization initiator B having a shorter half-life t.sub.B providing a ratio t.sub.A /t.sub.B of at least 1.5.
- 50. The image forming method according to claim 49, wherein the high-molecular weight styrene resin has been obtained through polymerization in the presence of a poly-functional polymerization initiator in an amount of 0.01-5 wt. % of a polymerizable monomer providing the high-molecular weight styrene resin.
- 51. The image forming method according to claim 49, wherein the high-molecular weight styrene resin has been obtained through polymerization in the presence of a poly-functional polymerization initiator in an amount of 0.05-3 wt. % of a polymerizable monomer providing the high-molecular weight styrene resin.
- 52. The image forming method according to claim 49, wherein the low-molecular weight vinyl resin has been obtained through polymerization at a polymerization temperature of 75.degree.-145.degree. C. in the presence of a polymerization initiator B having a half-life t.sub.B at least 0.1 hour at the polymerization temperature.
- 53. The image forming method according to claim 49, wherein the low-molecular weight vinyl resin has been obtained through polymerization at a polymerization temperature of 75.degree.-145.degree. C. in the presence of a polymerization initiator B having a half-life t.sub.B 0.5-10 hours at the polymerization temperature.
- 54. The image forming method according to claim 49, wherein the ratio t.sub.A /t.sub.B at the polymerization temperature is 2 to 5,000.
- 55. The image forming method according to claim 49, wherein the low-molecular weight vinyl resin has been obtained through polymerization at a polymerization temperature of 75.degree.-145.degree. C. in the presence of a polymerization initiator B having a half-life t.sub.B of 0.5-3 hours at the polymerization temperature and a polymerization initiator A having a half-life t.sub.A of 2-60 hours at the polymerization temperature.
- 56. The image forming method according to claim 55, wherein the ratio t.sub.A /t.sub.B is 2 to 500.
- 57. The image forming method according to claim 49, wherein the low-molecular weight vinyl resin has been obtained through polymerization in the presence of the polymerization initiators A and B in a total amount of 0.1-5 wt. parts per 100 wt. parts of a polymerizable monomer providing the low-molecular weight vinyl resin.
- 58. The image forming method according to claim 57, wherein the polymerization initiators A and B are used in a weight ratio (A/B) of 0.01-100.
- 59. The image forming method according to claim 57, wherein the polymerization initiators A and B are used in a weight ratio (A/B) of 0.01-10.
- 60. The image forming method according to claim 32, wherein the benzaldehyde content in the toner is at most 10 ppm.
- 61. The image forming method according to claim 32, wherein the styrene content in the toner is at most 50 ppm.
- 62. The image forming method according to claim 32, wherein the toner further contains 0.5-10 wt. parts of a waxy substance per 100 wt. parts of the binder resin.
- 63. The image forming method according to claim 32, wherein the charging member is a contact charging means.
- 64. The image forming method according to claim 63, wherein the charging member is supplied with DC voltage.
- 65. The image forming method according to claim 63, wherein the charging member is supplied with AC voltage.
- 66. The image forming method according to claim 63, wherein the charging member is supplied with DC voltage and AC voltage.
- 67. The image forming method according to claim 63, wherein the contact charging means comprises a charging roller.
- 68. The image forming method according to claim 67, wherein the charging roller is supplied with DC voltage.
- 69. The image forming method according to claim 67, wherein the charging roller is supplied with AC voltage.
- 70. The image forming method according to claim 67, wherein the charging roller is supplied with DC voltage and AC voltage.
- 71. The image forming method according to claim 32, wherein the transfer member comprises a transfer roller.
- 72. The image forming method according to claim 32, wherein the transfer member comprises a rotatable cylinder.
- 73. The image forming method according to claim 32, wherein the transfer member comprises an endless belt.
- 74. The image forming method according to claim 32, wherein the transfer member is supplied with DC voltage.
- 75. The image forming method according to claim 71, wherein the transfer roller is supplied with DC voltage.
- 76. The image forming method according to claim 32, wherein the charging member is a contact charging means and the transfer member comprises a transfer roller.
- 77. The image forming method according to claim 76, wherein the contact charging means comprises a charging roller.
Priority Claims (2)
Number |
Date |
Country |
Kind |
4-184715 |
Jun 1992 |
JPX |
|
5-116074 |
May 1993 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 08/077,388 filed Jun. 17, 1993 now abounded.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
5166027 |
Machida et al. |
Nov 1992 |
|
5185229 |
Sato et al. |
Feb 1993 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
77388 |
Jun 1993 |
|