JPS5849864B2 - Positively charging toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a positively chargeable toner used for electrophotography, electrostatic recording, etc.

More specifically, the present invention relates to a positively chargeable toner suitable for color development in this field.

As a developing method in this field, a dry developing method using a developer made by mixing fine particle toner containing a charge control agent and a carrier such as glass beads or iron powder has been known. .

An example of a positive charge control agent used in such a positively chargeable toner for dry development is fatty acid-modified nigrosine as described in Japanese Patent Publication No. 4825669.

However, since this charge control agent has a blackish brown color, although it can be used for black toner using carbon black as a colorant, it cannot be used for color toners such as blue, yellow, and red.

Other positive charge control agents include polyamine resins as 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 dispersion.

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 relates to a positively chargeable toner containing a resin, a colorant, and dialkyltin oxide, alkylaryltin oxide, and/or diaryltin oxide other than dibutyltin oxide.

The present invention is characterized in that dialkyltin oxide, alkylaryltin oxide, and/or diaryltin oxide other than dibutyltin oxide is used as a positive charge control agent. Not only is it suitable for toners, but it is also well dispersed in resins, so it is possible to obtain uniformly charged toners by 5%.

dialkyltin oxide, excluding dibutyltin oxide;
It is desirable that the alkylaryltin oxide and/or diaryltin oxide be blended in an amount of 0.5 to 10% by weight based on the resin.

If it is less than 0.5% by weight, the toner will lack positive chargeability and cannot be put to practical use.

In addition, if it exceeds 10% by weight, the positive chargeability of the toner becomes too thick, and the electrostatic attraction force with glass balls, iron powder, etc. used as a carrier increases, resulting in a decrease in the fluidity of the developer. or a decrease in image density.

dialkyltin oxides, excluding dibutyltin oxides;
Specific examples of alkylallyltin oxide and/or diaryltin oxide include dimethyltin oxide, dilauryltin oxide, methylphenyltin oxide,
Examples include butylphenyltin oxide and diphenyltin oxide.

As the resin used in the present invention, any conventionally known resin having a glass transition point of 40°C or higher and 150'C or lower, such as polystyrene resin, acrylic resin, epoxy resin, or polyester resin, can be used.

For example, polystyrene, chlorophorystyrene, holly α-
Methylstyrene, styrene-chlorostyrene copolymer,
Styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer,
Styrene-acrylate copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer) polymer), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate copolymer,
Styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl memethacrylate copolymer, etc.), styrene-α-methyl chloroacrylate copolymer, styrene-acrylonitrile-acrylic ester copolymer There are monopolymers and copolymers such as polymers.

The epoxy resin used in the present invention has an epoxy equivalent of 900
~3500.

Specific examples that can be particularly preferably used include Epicote 1004, Epicote 1007, Epicote 10
09 Both are manufactured by Shell.

Araldite}GY6084, Araldite GY6097
, 77/L/Die}GY6099, both manufactured by Ciba Geigy.

The polyester resin used in the present invention is a polycondensate consisting of a polyhydric alcohol and a polybasic acid. Preferred polyhydric alcohol components include, for example, ethylene glycol, glycerin, Pyrene glycol, neopentyl glycol, 1,4-butanediol, 6-hexanediol, 1,4-cyclohexanedimethanol, trimethylolethane, trimethylolpropane, pentaerythritol, etc. are used, and as polybasic acid components. For example, maleic acid, fumaric acid, isophthalic acid, terephthalic acid, adipic acid, sebacic acid, trimellitic acid, pyromellitic acid, etc. can be used.

The above resins can be used alone or in combination of two or more.

The coloring agent used in the present invention can be any conventionally known pigment such as carbon black, Rhodamine 6G Lake, Fuclocyanine Blue, Phthalocyanine Clean, Hansa Yellow G, etc., or monoazo type, disazo type, metal complex type monoazo type, anthraquinone type. Any conventionally known dyes such as cyanine dyes, lid cyanine dyes, and triallylmethane dyes can be used.

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 oil, as required.

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

Example 1 96 parts by weight of (styrene/n-butyl methacrylate) copolymer, 1 part by weight of rhodamine 6G lake pigment, and 3 parts by weight of dimethyltin oxide were dry mixed and then melt-kneaded.

After cooling, it was coarsely pulverized with a hammer mill and further finely pulverized with an air jet type pulverizer.

The obtained fine powder was classified to select particles having a particle diameter of 5 to 30 μm, which was used as a toner.

100 parts by weight of spherical iron oxide powder was mixed with 3 parts of this toner to prepare a developer.

The blow-off charge amount of this developer is +40.0 (μc/
1 Gutner).

On the other hand, as a comparative toner, a toner containing no dimethyltin oxide among the above formulations was prepared, and a developer was prepared in the same manner.

The blow-off charge amount of this developer is +8.2 (μc / 1
? 'pner).

After uniformly charging a selenium drum rotating at a circumferential speed of about 10 CIft/s with a corona voltage of +5 KV, the selenium drum is irradiated with light through a negative original, and then magnetically developed using a developer containing dimethyltin oxide among the two types mentioned above. Perform reversal development using the brush method, and then -5 from behind the plain paper.
A transferred image was obtained by applying a KV corona voltage.

The image clearly had a high image density and was clear with little fog.

Similarly, when a toner not containing dinotyltin oxide was used for development, toner scattering occurred from the developing machine, and only transferred images with a lot of fog and low image density were obtained.

Example 2 In exactly the same manner as in Example 1 except that the colorant was changed to phthalocyanine fluid, toner containing dimethyl tin oxide and toner not containing dimethyl tin oxide were prepared, developers were prepared, and the amount of flow-off charge was measured. did.

Toner containing dimethyltin oxide has a +32.5 (μ
c / 1 g toner), +0.3 (μ
c/1? }).

When development was carried out in the same manner as in Example 1 using both toners, it was found that when the toner containing dimethyltin oxide was used, a clear transferred image with clearly higher image density and less fog was obtained. Ta.

When a toner not containing dimethyltin oxide was used, toner scattering occurred violently from the developing machine, and the resulting transferred images had poor image density with a lot of fog.

Example 3 The same procedure as in Example 1 was carried out except that phthylphenyltin oxide was used in place of dimethyltin oxide.

The obtained developer has a blow-off charge amount of +43.5 (μc
/1? toner).

Further, as a result of performing reversal development in the same manner as in Example 1 using the obtained developer, the image clearly had a high image density and was clear with little fog.

Example 4 The same procedure as in Example 1 was carried out except that diphenyltin oxide was used in place of dimethyltin oxa,ide.

The obtained developer has a blow-off charge amount of +42.0 (μc
/1 Gutner).

Further, as a result of performing reversal development in the same manner as in Example 1 using the obtained developer, the image clearly had a high image density and was clear with little fog.

The present invention is characterized in that dialkyltin oxide, alkylaryltin oxide and/or diaryltin oxide other than dibutyltin oxide is used as a positive charge control agent, and these tin oxides are colorless and highly positively charged. Because of this ability, it provides a positively charged toner of the desired color without damaging the original hue of the colorant.

Further, since the above-mentioned tin oxide has good dispersibility in resin, it has the characteristic that a uniformly charged toner can be obtained. Therefore, if development is performed using the toner according to the present invention, a good image without fogging can be obtained.

Claims (1)

[Scope of Claims] 1. A positively chargeable toner containing a resin, a colorant, and dialkyltin oxide, alkylaryltin oxide, and/or diaryltin oxide other than dibutyltin oxide. 2. The positively chargeable toner according to claim 1, wherein the content of dialkyltin oxide, alkylaryltin oxide, and/or diaryltin oxide other than dibutyltin oxide is 0.5 to 10% by weight based on the resin. .