JPS6026952A - Positive electrostatically chargeable toner - Google Patents

Abstract

PURPOSE:To improve the image density of the positive-chargeable toner to be used for electrophotography and electrostatic recording and to prevent photographic fog by incorporating a resin, coloring agent and specific compd. into said toner. CONSTITUTION:A resin, coloring agent and the compd. expressed by the formula are incorporated into a toner. The compd. expressed by the formula is particularly used as a positive charge control agent. Since the control agent is colorless, said agent is particularly suitable for a color toner and moreover said agent disperses well into the resin and therefore the uniformly charged toner is obtainable. The control agent is preferably compounded within a 1-1.5wt% range of the resin. Pigments such as carbon black and phthalocyanine and various dyes are used for the coloring agent. Various resins such as polystyren resin, acrylic resin are used for the above-described resin. If R2NCH2CH2X.HCl is used as the positive charge control agent, the compd. is colorless and has a high capacity of positive charge power and therefore the positive charge toner of a desired color is obtd. without spoiling the hue intrinsic to the coloring agent and the image having no photographic fog is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to positively chargeable toners used in electrophotography and electrostatic recording traps. More specifically, regarding positively chargeable toner suitable for color development, the development method used in this field has conventionally been to use fine particle toner containing a charge control agent, etc., and a carrier such as glass beads or iron powder. A dry development method using a developer prepared by mixing is known.As a positive charge control agent used in such a positively chargeable toner for dry development, for example, the one described in Japanese Patent Publication No. 4B-25669 There is a fatty acid-modified nigrosine that has been used. However, since this charge control agent has a blackish brown color, it can be used for black toner using carbon black as a colorant, but it cannot be used for color toners such as blue, yellow, and red. Other positive charge control agents include Chiyu polyamine resin described in JP-A-51-9456.

Although this charge control agent is colorless and can be used for color toners, it has the drawback of poor compatibility with resins and difficulty in dispersing it.

An object of the present invention is to provide a positively chargeable toner which has all the drawbacks mentioned above improved.

That is, the present invention is a positively chargeable toner containing a resin 9 colorant and a compound represented by an alkyl group x==ci or OH such as (I) formula % R=cHs, C2H, etc. a2NCH20H2X- as a positive charge control agent
HCI (R=,, alkyl group such as CH3, C2H5,
Since the control agent is colorless, it is particularly suitable for color toners, and is also well-dispersed in resin, so it can be used for uniformly charged toners. It has the advantage of being able to obtain

It is desirable that the above-mentioned control agent is blended in an amount of 1 to 15% by weight based on the resin. If it is less than 1 weight, the toner will lack positive chargeability and cannot be put to practical use.

If it exceeds 15% by weight, the positive chargeability of the toner is too large and the electrostatic attraction force of glass beads or iron powder used as a carrier increases, resulting in a decrease in the fluidity of the developer. This results in a decrease in image density.

The colorant used in the present invention may be any conventionally known pigment such as carbon black, rhodamine 6G lake, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, or a monoazo pigment.

Any conventionally known dyes can be used, such as dis-Ay dyes, gold-17R complex type monoazo dyes, anthraquinone dyes, phthalocyanine dyes, and triallylmethane dyes.

The colorant is used in an amount of 0.1 to 50 parts by weight based on the resin,
The ratio may be determined as appropriate depending on the case. In some cases, more than 50 parts by weight may be used.

The positively chargeable toner according to the present invention may contain any conventionally known additives such as colloidal silica, metal salts of fatty acids, fluoropolymers, and silicone oils, if necessary.

The resin used in the present invention is polystyrene resin.

Any conventionally known resin having a glass transition point of 40° C. or higher and 150° C. or lower, such as acrylic resin, epoxy resin, or polyester resin, can be used. For example, folystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer.

Styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer.

Styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer).

styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer),
Styrene-methacrylic acid ester copolymer (styrene-
Methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer.

(styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate copolymer, etc.), styrene-α-methyl chloroacrylate copolymer, styrene-acrylonitrile-acrylic acid ester copolymer, etc. Combined. The epoxy resin used in the present invention preferably has an epoxy equivalent of 900 to 3,500. Specific examples that can be particularly preferably used include Ebisu) 10
04, Ebi two) jDO7, Epicote 1 [10
9 (all manufactured by Shell). Araldite GY6084
, Araldai) (, Y6097, Araldai) GY
6099 (all manufactured by Ciba Geigy).

The polyester resin used in the present invention is a polycondensate consisting of a polyhydric alcohol and a polybasic acid, and preferred polyhydric alcohol components include, for example, ethylene glycol, glycerin, 1,2-propylene glycol, 1-3- Propylene glycol, neopentyl glycol, 1-4 butanediol, 1-6 hexanediol, 1-4 cyclohexane dimetatool, trimethylolethane, trimethylolpropane, pentaerythritol, etc. are used.
Further, as the polybasic acid component, for example, maleic acid, fumaric acid, isophthalic acid, terephthalic acid, adipic acid, sebacic acid, trimellitic acid, pyromellitic acid, etc. can be used. The above resin foams can be used alone or in combination of two or more.

Hereinafter, the present invention will be specifically explained with reference to Examples.

[Example 1] 98 parts by weight of (styrene/n-butyl methacrylate) copolymer, 1 part by weight of p-damin 6G lake pigment and (C3H
5), NC, H2 ('jH2C1, HGl) 4 parts by weight were mixed in a high-speed mixer, then melted and kneaded in a roll mill. After cooling, the mixture was coarsely ground in a hammer mill, and further finely ground in an air jet type pulverizer. The obtained fine powder was classified and 25 to 30 μm was selected to make a toner. 6 parts by weight of this toner was mixed with 100 parts by weight of spherical iron oxide powder to prepare a developer. 10 of this developer - Off charge amount is +1
8.2 (μc/1g).

On the other hand, as a comparison toner, among the above formulations, (CH3)2N
OH, OH, CA! - A toner containing no HGI was prepared, and a developer was prepared in the same manner. The proof-off charge amount of this developer was +6.6 (μc/1g).The corona voltage was +5
After uniformly charging with KV, the selenium drum is irradiated with light through a negative original, and one of the above two types (OH,) 2NCj
Using a developer containing H20H2Cjl and HOl,
Reversal development was performed using a magnetic brush method, and then a corona voltage of 15 KV was applied from behind the plain paper to obtain a transferred image. The image was clearly clear with high image density and little capri. Similarly C0Hs)xNGH20H201-
When development was carried out using a toner not containing HCl, toner scattering occurred from the developing machine, and only a transferred image with a large amount of capri and low image density was obtained.

[Example 2] In the same manner as in Example 1 except that the coloring agent was changed to 7 talocyanine blue, (CzHs)2NcH2CH20
6 parts by weight of H-HCIJ was prepared, a developer was prepared, and the amount of blow-off charge was measured. (CzHs)2NcH2c
H,0H-HC1! Toner containing +14.7 (μQ/
Ig) toner), +3.8 (μc/l without toner)
g) ner).

When development was carried out in the same manner as in Example 1 using both toners, (CzH6)2NCH2CHzOH0
When the toner containing HGl was used, a clear transferred image with clearly high image density and little capri was obtained. When a toner not containing (C2H6) 2NCH2CH20H-HGI was used, toner scattering occurred violently from the developing machine, and the resulting transferred image had a poor image density with a large amount of capri.

The present invention uses R2NCH20H2X,
H (characterized by the use of J, R2NCH, CH2
Since X, HC; l is colorless and has a high degree of positive chargeability, it provides a positively chargeable toner of a desired color without impairing the colorant's original hue. Also R2NCH2CH2
Since X-HGI has a characteristic of being able to obtain a toner with uniform charge due to its good dispersibility in the ridge resin, a good image without capri can be obtained even when the toner according to the present invention is used for development.

← J-engineer...j arrogant

Claims (2)

[Claims] (1) Resin 2 Colorant and the compound represented by formula (1) are R
2NGHzGH2X-HCl...(I) Input R=Q
Alkyl group x=ci or O
H Contains positively chargeable toner 0 (2) The compound represented by formula (I) is 1 to
The positively chargeable toner according to claim 1, which has a toner of 15 Wt*.