JP2000019782A - Positively chargeable toner - Google Patents

Abstract

[PROBLEMS] To provide a positively chargeable toner capable of maintaining excellent image quality even when used for a long time in a non-magnetic one-component developing method using a positively chargeable organic photoreceptor, and a positive chargeability of the toner. Provide a way to adjust. A binder resin and a compound represented by the formula (I): Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a chlorine atom, a methyl group, a methoxy group, a nitro group, a —CONH ₂ group or a —CONHC ₆
Positively charged toner, and a method of a compound represented by the formula (I) be contained in the toner for adjusting the positively chargeable toner contains a compound represented by showing a H ₅ group).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positively chargeable toner used for developing an electrostatic latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like, and to adjust the positive chargeability of the toner. On how to do it.

[0002]

2. Description of the Related Art Positively charged organic photoreceptors used in a non-magnetic one-component developing method are inferior in sensitivity as compared with inorganic photoreceptors (Se type) which have been used so far. It is necessary to apply a higher developing bias potential in order to obtain. Therefore, the potential difference between the surface potential of the non-exposed portion and the developing bias potential is smaller than that of the inorganic photoreceptor, and the image quality tends to be deteriorated during long-term use.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a positively chargeable toner which can maintain excellent image quality even when used for a long time in a non-magnetic one-component developing system using a positively chargeable organic photoreceptor. It is an object of the present invention to provide a method for adjusting the positive charging property.

[0004]

The gist of the present invention is to provide (1) a binder resin and a compound represented by the formula (I):

[0005]

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(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a chlorine atom, a methyl group, a methoxy group, a nitro group, a —CONH ₂ group Or-
CONC ₆ H ₅ group), and (2) a method of adjusting the positive charge of the toner by adding the compound represented by the formula (I) to the toner; About.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION As the binder resin used in the positively chargeable toner of the present invention, a resin generally used for a toner is used. For example, polyester, polyamide, acrylic resin, epoxy resin, polycarbonate, polyurethane, Examples thereof include a silicone resin, a fluorine resin, a petroleum resin, and natural and synthetic waxes. Of these, polyester is preferable because it can achieve both color development and durability of the toner. From the viewpoint of ensuring the durability of the toner and the dispersibility of the colorant, such a polyester is desirably contained in the binder resin in an amount of 70% by weight or more, preferably 90 to 100% by weight.

The polyester is, for example, of the formula (II):

[0009]

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Wherein R ⁷ is an alkylene group having 2 to 4 carbon atoms, x and y are positive numbers, and the sum of the average values is 1 to
A polyhydric alcohol component containing a compound represented by the formula (III):

[0011]

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(R ⁸ and R ⁹ may be the same or different and each represent a hydrogen atom or a hydrocarbon group having 4 to 20 carbon atoms), or a divalent carboxylic acid or an anhydride or alkyl thereof. It is obtained by condensation polymerization of an acid component containing 1 to 50 mol% of an ester having 1 to 8 carbon atoms and 0 to 30 mol% of trimellitic acid or its anhydride or alkyl (1 to 8 carbon atoms) ester. be able to.

The compound represented by the formula (II) includes, for example, polyoxypropylene (2.2) -2,2-bis
(4-Hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and the like, alkylene oxide (addition mole number 1 to 10) adducts of bisphenol A and the like. These, from the viewpoint of durability, contain 7
Preferably, it is contained at 0% or more. Examples of other polyhydric alcohol components include, for example, ethylene glycol, propylene glycol, glycerin, pentaerythritol, trimethylolpropane, hydrogenated bisphenol A, sorbitol, and etherified polyhydroxyl compounds thereof, and the like. It is preferable to contain one or more.

The divalent carboxylic acid represented by the formula (III) is, for example, substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms such as dodecenylsuccinic acid and octylsuccinic acid. And succinic acid. Examples of other acid components include dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, and maleic acid, pyromellitic acid, anhydrides of these acids, and alkyls of these acids (having 1 carbon atom). To 8) esters and the like, and it is preferable to contain one or more of these.

The polyester can be produced, for example, by subjecting a polyhydric alcohol component and an acid component to polycondensation at 180 to 250 ° C. in an inert gas atmosphere, if necessary, using an esterification catalyst. it can.

The acid value of the polyester is preferably 10 (KOH mg / g) or less in order to ease the negative charging property of the resin itself. In the present invention, the acid value of the polyester can be controlled within the above range by adjusting the amounts of the starting materials alcohol and carboxylic acid and the reaction conditions. Specific examples include a method in which the amount of the alcohol used is excessive relative to the carboxylic acid, a method in which the reaction is performed until the acid value decreases, and the like.

The glass transition point of the polyester is 55 to 80.
° C and a softening point are preferably 80 to 150 ° C.

A major feature of the present invention is that the formula (I):

[0019]

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(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom, a chlorine atom, a methyl group, a methoxy group, a nitro group, a —CONH ₂ group Or-
CONHC ₆ H ₅ group).

As the compound represented by the formula (I), for example,
For example, Pigment Red 146 [R ¹Is a methoxy group, R
^TwoIs a hydrogen atom, R^ThreeIs -CONHC₆H_FiveGroup, R^FourBut
Toxic group, R^FiveIs a chlorine atom, and R⁶Is a methoxy group
Compound], Pigment Red 147 [R¹Is methoki
Si group, R^TwoIs a hydrogen atom, R^ThreeIs -CONHC₆H_FiveGroup,
R^FourIs a chlorine atom, R^FiveIs a hydrogen atom, and R⁶Is a methyl group
Which is a compound of the following formula), Pigment Red 184 [Pigment Red
Mixing tread 146 and pigment red 147
Products), and it is possible to use one or more of these.
Wear. This compound was written by W. Herbest, K. Hunger.
"Industrial Organic Pigments" (1993, VCH Verlag
sgesellschaft mbH).
It is a compound that can be easily obtained.

In the present invention, the compound represented by the formula (I)
Among them, from the viewpoint of the ability to adjust the positive chargeability, R¹Is methoxy
Group, R^TwoIs a hydrogen atom, R^ThreeIs -CONHC₆H_FiveGroup, R
^Four, R ^FiveAnd R⁶Are each independently a hydrogen atom, a salt
Compounds which are a hydrogen atom, a methyl group or a methoxy group are preferred.
K, R¹Is a methoxy group, R^TwoIs a hydrogen atom, R^ThreeIs -CO
NHC₆H_FiveGroup, R^FourIs a methoxy group, R^FiveIs a chlorine atom,
R⁶Is a methoxy group, and R¹Is methoxy
Group, R^TwoIs a hydrogen atom, R^ThreeIs -CONHC₆H_FiveGroup, R
^FourIs a chlorine atom, R^FiveIs a hydrogen atom, R⁶Is a methyl group
Compounds are more preferred.

The content of the compound represented by the formula (I) is based on 100 parts by weight of the binder resin in terms of charge control ability.
It is desirable that the amount be 0.1 part by weight or more, preferably 0.5 part by weight or more, and 10 parts by weight or less, preferably 5 parts by weight or less in order to adjust the hue of the toner.

The compound represented by the formula (I) is characterized in that when it is contained in a toner, it exerts not only a colorant but also a positively-chargeable charge control action. By containing the toner together with the charge control agent, the effect of adjusting the positive charge of the toner can be remarkably exhibited.

As the positively chargeable charge control agent used in the present invention, a nigrosine dye, for example, "Nigrosine base E
X "," Oil Black BS "," Oil Black S "
O "," Bontron N-01 "," Bontron N-0 "
4 "," Bontron N-07 "," Bontron N-0 "
9 "," Bontron N-11 "," Bontron N-1 "
Quaternary ammonium salts such as "Bontron P-51" and "Bontron P-53" (both manufactured by Orient Chemical Industries), "T"
P-415 "(manufactured by Hodogaya Chemical Industry Co., Ltd.), cetyltrimethylammonium bromide, etc .; a triphenylmethane dye containing a tertiary amine as a side chain, such as" COPYCHARGE "
PR "(manufactured by Hoechst) and the like; polyamine resins such as" Bontron P-52 "and" AFP-B "(all manufactured by Orient Chemical Industries) and the like; imidazole derivatives such as" PLZ-2001 "and" PLZ-8001 ". "(that's all,
Or the like, and one or more of these can be used. In the present invention, from the viewpoint of positive chargeability, a nigrosine dye and a quaternary ammonium salt are preferable, and a nigrosine dye is more preferable.

The content of the compound represented by the formula (I) / the content of the positively chargeable charge control agent is represented by a weight ratio of 1 / 0.1 to 1/1.
5, it is desirable to adjust so as to be 1 / 0.5 to 1/2.

The positively chargeable toner of the present invention can be obtained by a kneading and pulverizing method,
It can be produced by a conventionally known method such as a spray drying method and a polymerization method. For example, binder resin, formula (I)
Is uniformly mixed with a mixing machine such as a ball mill, and then mixed in a closed kneader or a single-shaft or two-shaft.
A method of melt-kneading with a shaft extruder or the like, followed by cooling, pulverization, and classification is used. The average particle diameter of the positively chargeable toner of the present invention is preferably about 3 to 20 μm.

The colorant is not particularly limited, and dyes and pigments used as conventional colorants for black toner or color toner can be used. Examples thereof include carbon black, phthalocyanine blue, and permanent brown FG. , Brilliant First Scarlet, Pigment Green B, Rhodamine-B base, Solvent Red 49, Solvent Red 146, Solvent Blue 35,
Quinacridone, carmine 6B, disazo yellow and the like. The content of the colorant is preferably 2 to 25 parts by weight based on 100 parts by weight of the binder resin.

The positively chargeable toner of the present invention includes a magnetic substance such as ferrite, a conductivity adjuster, a metal oxide such as tin oxide, silica, alumina, zirconia, titania, cerium oxide, and zinc oxide; , Reinforcing fillers such as fibrous substances, antioxidants, antioxidants, release agents, flow improvers,
Additives such as a cleaning property improver may be appropriately added.

The positively chargeable toner of the present invention is used alone as a developer when it contains magnetic fine powder, as a non-magnetic one-component developer when it does not contain magnetic fine powder, or mixed with a carrier. Although it is used as a two-component developer, it is preferably used as a non-magnetic one-component developer in terms of simplicity and miniaturization of the apparatus. In particular, when the positively chargeable toner of the present invention is used in a non-magnetic one-component developing method using a positively chargeable organic photoreceptor, an excellent image can be obtained more effectively.

In the present invention, as described above, the compound represented by the formula (I) can be contained in the toner to adjust the positive chargeability of the toner.

[0032]

EXAMPLES The acid value and the glass transition point were measured according to the following methods.

[Glass Transition Point] The glass transition point is measured at a heating rate of 10 ° C./min using a differential scanning calorimeter (DSC210, manufactured by Seiko Instruments Inc.). [Acid value] It is measured according to a method according to JIS K0070.

Resin Production Example 1 Polyoxypropylene (2.2) -2,2-bis (4-
2630 g of hydroxyphenyl) propane, 1050 g of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 970 g of terephthalic acid,
Under nitrogen atmosphere, 335 g of isododecenyl succinic anhydride, 310 g of trimellitic acid and 13 g of dibutyltin oxide were added under nitrogen atmosphere.
The reaction was continued while stirring at 30 ° C until the softening point measured according to ASTM E28-67 reached 149 ° C.
The obtained resin is referred to as polyester A. Polyester A
Has a glass transition point of 62 ° C. and an acid value of 6 (KOHmg / g).
Met.

Example 1 89 parts by weight of polyester A Pigment Red 147 (manufactured by Clariant) 2 parts by weight Charge control agent "Bontron N-04" (manufactured by Orient Chemical Industries) 3 parts by weight Carbon black "REGAL-330R" (Cabot) 4 parts by weight Polyethylene 1 part by weight "Sazole Wax Spray 105" (manufactured by Sasol) 1 part by weight of polypropylene wax "NP-055" (manufactured by Mitsui Petrochemical Industries, Ltd.) The above composition was heated to 110 ° C. 2 After kneading with a shaft kneader, the mixture was quickly cooled. The obtained cooled product is coarsely pulverized by a mechanical pulverizer so as to pass a mesh of 2 mm, and has an average particle diameter in weight distribution of 9.5 using a wind pulverizer / classifier.
A μm powder was obtained. Thereafter, 100 parts by weight of the obtained powder and hydrophobic silica (HVK-2150, manufactured by Wacker Inc.)
0.5 parts by weight were mixed using a high-speed stirrer to obtain Black Toner 1.

Example 2 In Example 1, the amount of the polyester A was changed to 88 parts by weight, and the charge control agent "Bontron P-51" was further added.
Except for using 1 part by weight (manufactured by Orient Chemical Industries),
Black toner 2 was obtained in the same manner as in Example 1.

Example 3 A black toner 3 was obtained in the same manner as in Example 1, except that Pigment Red 147 was replaced by 2 parts by weight of Pigment Red 146 (manufactured by Clariant).

Example 4 A black toner 4 was obtained in the same manner as in Example 1, except that Pigment Red 147 was replaced by 2 parts by weight of Pigment Red 184 (manufactured by Clariant).

Example 5 Polyester A 97 parts by weight Pigment Red 184 (manufactured by Clariant) 3 parts by weight Using the above composition, red toner 5 was obtained in the same manner as in Example 1.
I got

Example 6 Polyester A 94 parts by weight Pigment Red 184 (manufactured by Clariant) 3 parts by weight Charge control agent “Bontron P-51” (manufactured by Orient Chemical Industries) 3 parts by weight Example 1 using the above composition Red toner 6 in the same manner as
I got

Comparative Example 1 Comparative toner 1 was obtained in the same manner as in Example 1 except that Pigment Red 147 was not used and that the amount of polyester A used was 91 parts by weight.

Test Example 1 A page printer "HL-730" (manufactured by Brother Industries, Ltd.) using black toners 1-4, red toners 5, 6 and comparative toner 1 and using a positively charged organic photoreceptor. Was used to evaluate the image quality after printing after printing for 20,000 sheets intermittently with the initial image quality and printing rate of 4% according to the following method, and the durability of each toner was examined. Table 1 shows the results.

[Image Quality] Fog of the photoreceptor, scattering of toner and roughness of solid printing image quality are visually evaluated according to the following evaluation criteria.

[Evaluation Criteria] 良好: Particularly good ○: Practical acceptable ×: Not practical

[0045]

[Table 1]

From the above results, when the black toners 1 to 4 and the red toners 5 and 6 are used, excellent image quality can be obtained both at the initial stage and after printing, whereas the expression (I) is used. It can be seen that when the comparative toner 1 in which the compound to be used was not used was used, the image quality deteriorated due to the intermittent printing of 20,000 sheets.

[0047]

According to the present invention, a positively chargeable toner capable of maintaining excellent image quality even when used for a long time in a non-magnetic one-component developing system using a positively chargeable organic photoreceptor, and a positive charge of the toner. A method of adjusting gender can be provided.

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Eiji Shirai 1334 Minato, Wakayama-shi Kao Corporation Research Institute F-term (reference) 2H005 AA06 CA21 CA28 DA03 FA07

Claims (5)

[Claims] 1. A binder resin and a compound represented by the formula (I): Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a chlorine atom, a methyl group, a methoxy group, a nitro group, a —CONH ₂ group or a —CONHC ₆
Positively chargeable toner containing a compound represented by showing a H ₅ group). 2. The positively chargeable toner according to claim 1, wherein the positively chargeable toner is a black toner. 3. The positively chargeable toner according to claim 1, further comprising a compound represented by formula (I) together with the positively chargeable charge control agent. 4. The positively chargeable toner according to claim 3, wherein the positively chargeable charge control agent is a nigrosine dye and / or a quaternary ammonium salt. 5. A compound of the formula (I): Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a chlorine atom, a methyl group, a methoxy group, a nitro group, a —CONH ₂ group or a —CONHC ₆
A compound represented by H ₅ group) to adjust the positive chargeability of the toner.