Toner for developing electrostatic image containing higher and lower molecular weight polymer components

• US 5,744,276 A
• Filed: 03/30/1994
• Issued: 04/28/1998
• Est. Priority Date: 03/31/1993
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Suzuki, Shunji, Nakazawa, Akihiko, Okubo, Nobuyuki, Ohno, Manabu, Suematsu, Hiroyuki
• Primary Examiner(s): Rodee, Christopher D.
• Application Number:
  US08/220,044
• Time in Patent Office: 1,490 Days
• Field of Search: 430/110, 430/111, 430/109
• US Class Current: 430/108.23
• CPC Class Codes: G03G 13/20 Fixing, e.g. by using heat
• CPC Class Codes: G03G 2215/021 by contact, friction or induction
• CPC Class Codes: G03G 2221/183 Process cartridge
• CPC Class Codes: G03G 9/0821 characterised by physical parameters magnetic parameters G03G9/083
• CPC Class Codes: G03G 9/08711 with esters of acrylic or methacrylic acid
• CPC Class Codes: G03G 9/08791 characterised by the presence of specified groups or side chains
• CPC Class Codes: G03G 9/08793 Crosslinked polymers
• CPC Class Codes: G03G 9/08795 characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants
• CPC Class Codes: G03G 9/091 Azo dyes
• CPC Class Codes: G03G 9/09783 Organo-metallic compounds

Abstract

An electrophotographic toner composition suitable for heat-fixation and showing good storage characteristics is constituted by polymer components, a colorant and a metal-containing organic compound. The toner composition shows a melt index (at 125° C., 10 kg-load) of 5-25 g/10 min., and the polymer components are characterized by (a) containing substantially no THF (tetrahydrofuran)-insoluble content, (b) including a THF-soluble content thereof providing a GPC (gel permeation chromatography) chromatogram showing i) a main peak in a molecular weight region of 2×10³ -3×10⁴, and a sub-peak or shoulder in a molecular weight region of at least 10⁵, and ii) an areal percentage of 3-10% in a molecular weight region of at least 10⁶, and (c) including a polymer component (H) in a molecular weight region of at least 10⁵ obtained by polymerization using a polyfunctional polymerization initiator and a monofunctional polymerization initiator.

Claims

1. A toner composition for developing an electrostatic image, comprising:

polymer components, a colorant and a metal-containing organic compound, wherein

the composition shows a melt index (at 125°

C., 10 kg-load) of 5-25 g/10 min., and

the polymer components are characterized by

(a) having a THF (tetrahydrofuran)-insoluble content from 0 to 5 wt. %,

(b) including a THF-soluble content thereof providing a GPC (gel permeation chromatography) chromatogram showing

i) a main peak in a molecular weight region of 2×

10³ -3×

10⁴, and a sub-peak or shoulder in a molecular weight region of at least 10⁵, and

ii) an areal percentage of 3-10% in a molecular weight region of at least 10⁶, and

(c) including a polymer component (H) providing the sub-peak or shoulder in the molecular weight region of at least 10⁵ obtained by polymerization using a polyfunctional polymerization initiator and a mono-functional polymerization initiator, said polymer component (H) comprising a monomer unit (A) having at least one species of carboxyl group, carboxylic acid salt group or carboxylic anhydride group.

3. The toner composition according to claim 1 or claim 2, which has dynamic visco-elasticities including a dynamic loss modulus (G") and a dynamic loss tangent (tan δ

) which is a ratio of G" to a dynamic storage modulus (G'"'"') at 200°

C. and 150°

C. satisfying the following conditions;

1≦

tan δ

₁₅₀ /tan δ

₂₀₀ ≦

2,

space="preserve" listing-type="equation">10.sup.3 dyn/cm.sup.2 ≦

G".sub.200 ≦

G".sub.150 ≦

10.sup.5 dyn/cm.sup.2.

4. The toner composition according to claim 1 or claim 2, which has a THF-insoluble content of at most 3 wt. %.

5. The toner composition according to claim 1 or claim 2, wherein the polymer components include a low-molecular weight fraction having molecular weights of below 10⁵ showing an acid value of at most 3.0.

6. The toner composition according to claim 5, wherein the polymer components include a low-molecular weight fraction having molecular weights of below 10⁵ showing an acid value of at most 1.5.

7. The toner composition according to claim 5, wherein the polymer components include a high-molecular weight fraction having molecular weights of at least 10⁵ showing an acid value above 3.0.

8. The toner composition according to claim 7, wherein the polymer components include a high-molecular weight fraction having molecular weights of at least 10⁵ showing an acid value above 5.0.

9. The toner composition according to claim 1 or claim 2, wherein the polymer components include a high-molecular weight fraction having molecular weights of at least 10⁵ containing 1-20 wt. % of a carboxyl group-containing monomer unit.

10. The toner composition according to claim 9, wherein the polymer components include a high-molecular weight fraction having molecular weights of at least 10⁵ containing 3-15 wt. % of a carboxyl group-containing monomer unit.

11. The toner composition according to claim 1 or claim 2, wherein the polymer components have a glass transition temperature of 50°

-70°

C.

12. The toner composition according to claim 11, wherein the polymer components have a glass transition temperature of 55°

-65°

C.

13. The toner composition according to claim 1 or claim 2, which has a melt index of 8-20 g/10 min.

14. The toner composition according to claim 1 or claim 2, wherein the polymer component (H) contains at most 1 wt. % of a crosslinking monomer unit.

15. The toner composition according to claim 14, wherein the polymer component (H) contains 0.001-0.05 wt. % of a crosslinking monomer unit.

16. The toner composition according to claim 1 or claim 2, which further comprises a low-molecular weight wax having a weight-average molecular weight of at most 3×

10⁴.

17. The toner composition according to claim 16, which contains 1-20 wt. parts of the low-molecular weight wax per 100 wt. parts of the polymer components.

18. The toner composition according to claim 1 or claim 2, wherein the metal-containing organic compound is represented by the following formula I!:

##STR8## wherein M is a coordination center metal having a coordination number of 6, selected from the group consisting of Cr, Co, Ni, Mn and Fe;

Ar is phenyl or naphthyl optionally substituted with nitro, halogen, carboxyl, anilide, or alkyl and alkoxy having 1-18 carbon atoms;

X, X'"'"', Y and Y'"'"' independently denote --O--, --CO--, --NH--, or --NR--, wherein R is an alkyl having 1-4 carbon atoms; and

A.sup.⊕

is hydrogen, sodium, potassium, ammonium or aliphatic ammonium.

19. The toner composition according to claim 1 or claim 2, wherein the metal-containing organic compound is represented by the following formula II!:

##STR9## wherein M is a coordination center metal having a coordination number of 6 selected from the group consisting of Cr, Co, Ni, Mn and Fe;

A is ##STR10## optionally substituted with an alkyl group, ##STR11## wherein X is hydrogen, alkyl, halogen, or nitro, ##STR12## wherein R is hydrogen, C₁ -C₁₈ alkyl or C₁ -C₁₈ alkenyl;

Y.sup.⊕

is a counter ion selected from the group consisting of hydrogen, sodium, potassium, ammonium, and aliphatic ammonium; and

Z is --O-- or --CO--O--.

2. A toner composition for developing an electrostatic image, comprising:

polymer components, a colorant and a metal-containing organic compound, wherein

the composition shows a melt index (at 125°

C., 10 kg-load) of 5-25 g/10 min., and

the polymer components are characterized by

(a) having a THF (tetrahydrofuran)-insoluble content from 0 to 5 wt. %,

(b) including a THF-soluble content thereof providing a GPC (gel permeation chromatography) chromatogram showing

i) a main peak in a molecular weight region of 2×

10³ -3×

10⁴, and a sub-peak or shoulder in a molecular weight region of at least 10⁵, and

ii) an areal percentage of 3-10% in a molecular weight region of at least 10⁶, and

(c) including a polymer component (H) providing the sub-peak or shoulder in the molecular weight region of at least 10⁵ obtained by polymerization using a polyfunctional polymerization initiator and a mono-functional polymerization initiator, said polymer component (H) comprising a monomer unit (A) having at least one species of carboxyl group, carboxylic acid salt group or carboxylic anhydride group and a crosslinking monomer unit (B) in a ratio satisfying 20<

A/B<

10,000 by weight.