JPH0778649B2 - Positively charged toner - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to toners, especially positively charged toners, used in the development of electrostatic latent images.

2. Description of the Related Art Development of an electrostatic latent image is carried out by various methods, for example, electrostatically adsorbing toner charged by friction with a carrier or a sleeve to an electrostatic latent image formed on a photoconductor. Then, the toner image is transferred onto the transfer paper and fixed to obtain a copy image.

Therefore, this toner is adjusted to have an appropriate charge amount in order to obtain clear development without fog and to prevent the toner from scattering to stain the printing apparatus.

The chargeability is controlled by 1) using the chargeability of the binder resin used to form the toner, 2) using the chargeability of the pigment or dye, 3) treating the toner surface, or 4) using these methods in combination. Is the current situation.

However, recently, color copy images including full-color and mono-color have been desired, and search for colorless or white charge control agents that can be used for color toners has been conducted, but the above 1) to 3). It is practically difficult to control the charge of the color toners only by the control method described in (4) above, and at the present time, the color toner is unsatisfactorily used in combination with (4). .

Conventionally, as a positive charge control agent that imparts a positive charge, a nigrosine dye or an amino group-containing resin has been used.
Since the nigrosine dye is a black dye, it cannot be used for color toners other than black toner. In addition, in the case of an amino group-containing resin, the charging is delayed by the resin so that the charge rises slowly and the fog increases.
At present, there is no positive charge control agent that can be effectively used for positive charge color toners.

The inventors of the present invention have made extensive studies in view of such circumstances, and as a result, have found that a quaternary polymer salt is effective as a charge control agent for positively charged toner, and have completed the present invention.

On the other hand, a toner using a quaternary ammonium compound is disclosed in, for example, JP-B-60-9263 or JP-A-60-169857.

Japanese Examined Patent Publication (Kokoku) No. 60-9263 discloses a one-component magnetic toner to which conductivity is imparted by using a quaternary ammonium salt, and conductivity is imparted by the hygroscopicity of the quaternary ammonium salt. There is no particular description on the improvement and improvement of the charging property which the present invention is to disclose. Further, it is known that a substance that absorbs water is generally not suitable for controlling the charging property, and the compound of the above invention is not suitable for controlling the charging property.

JP-A-60-169857 discloses a toner containing a salt-forming compound of naphtho-sulfonic acid and a quaternary ammonium salt having a higher alkyl group or a benzyl group having a large number of carbon atoms. The salt is a different compound from the high molecular quaternary salt disclosed in the present invention. Furthermore, when the present inventors conducted a test using a compound similar to the compound described in the above invention, the content ratio of nitrogen was extremely small compared to the size of the whole molecule. It became clear that the effect was substantially small.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention An object of the present invention is to provide a positive charging toner containing a colorless or pale color positive charge control agent that does not adversely affect the hue during color copying.

Means for Solving the Problems The present invention is characterized in that a toner containing at least a thermoplastic resin, a pigment and / or a dye contains a polymer quaternary salt represented by the following general formula (I) as a charge control agent. And positively chargeable toner; (In the formula, R ₁ represents a hydrogen atom, a C _{1 to} C ₁₇ alkyl group, or an aryl group, and R ₂ , R ₃ and R ₄ may be the same or different, and each is a hydrogen atom. Or C _{1 to} C
₁₇ represents an alkyl group, X represents a halogen atom, an anion such as sulfonic acid or naphtho-sulfonic acid, and n
Each represents an integer of 2 or more).

In the above general formula, R ₁ is a hydrogen atom, methyl, ethyl,
C _{1 for} propyl, hexyl, undecyl, heptadecyl, etc.
To C ₁₇ alkyl group or C _{6 to} C ₈ aryl group such as phenyl, tolyl, xylyl group and the like, R ₂ , R ₃ and R
₄ may be the same or different, a hydrogen atom,
Represents a C _{1 to} C ₁₇ alkyl group such as methyl, ethyl, propyl, hexyl, undecyl, heptadecyl group, X is a halogen atom, sulfonic acid or naphthol-sulfonic acid represented by the following formula (II); However, the present invention is not limited to those described above.

Since the polymer quaternary salt represented by the general formula (I) of the present invention is white or light in color, it is possible to produce a color toner having a clear color.

In addition, since the polymer quaternary salt represented by the general formula (I) of the present invention has excellent thermal stability, it does not decompose thermally during toner production and does not generate an unpleasant amine odor. It also has the effect of improving environmental friendliness.

As the polymer quaternary salt represented by the general formula (I) of the present invention, those shown in Table 1 can be mentioned.

Since all of these quaternary high molecular weight compounds are white or light-colored compounds, they are useful as charge control agents for color toners, especially as positive charge control agents. Further, since it is insoluble or hardly soluble in cold water, it becomes a control agent excellent in environmental stability.

As the method for producing the quaternary polymer salt represented by the general formula (I), for example, the method described in JP-A-59-138228 can be cited, and a method similar to that method can be used. it can.

The positively chargeable toner of the present invention contains a high molecular quaternary salt represented by the general formula [I] as a positive charge control agent in a thermoplastic resin, and can be used particularly in color toners.

Since the polymer quaternary salt of the present invention has excellent chargeability, the toner using it has stable chargeability and less scattering.
It has excellent environmental stability.

Examples of the thermoplastic resin that can be used in the present invention include styrene resins, styrene acrylic copolymer resins, polyester resins, epoxy resins, polyethylene, polyalkylene resins such as polypropylene, and mixed resins in which these are arbitrarily blended. Further, it can be selected from those having an amino group in the alkyl side chain, but any one can be used as long as it can be used as a toner, and the resin is not particularly limited. .

The mixing ratio of the thermoplastic resin and the polymer quaternary salt represented by the general formula [I] is 0.5 per 100 parts by weight of the resin.
Appropriately within the range of -10 parts by weight, preferably 1-5 parts by weight. This is because if it is less than 0.5 parts by weight, the effect of controlling the charge is not sufficient, and if it is used in excess of 10 parts by weight, not only the charge controllability does not increase, but also the charge amount becomes low.

Further, in order to obtain a monocolor toner of blue, red, green or the like or a full color toner of cyan, magenta, yellow or the like, the corresponding colorant may be used in combination with the positive charge control agent of the present invention. As the colorant, a commonly used organic or inorganic pigment or dye may be used.

Red colorants include resole red, watching red, carmine 6B, lake red C, chromophthal red, etc., blue colorants such as Cu-phthalocyanine, and green colorants include chlorinated or brominated compounds. Cu-
Phthalocyanine or the like, as a yellow colorant, benzidine yellow, Hansa yellow, chromophthal yellow or the like, and as a black colorant, a carbon black, for example,
Furnace black, channel black, acetylene black and the like can be mentioned.

The inorganic pigments include white, titanium white and zinc white, and the black pigments include iron black and cupric oxide. It is not limited to these, regardless of whether they are inorganic or not.

Other colorants include dyes such as azo dyes, anthraquinone dyes, indigoid dyes, quinone imine dyes, methine dyes, and carbonium dyes, but any dye capable of producing a vivid color in a resin is not particularly limited. Not a thing.

The colorant such as the pigment or dye is 0.5 to 40 parts by weight, preferably 1 to 30 parts by weight, relative to 100 parts by weight of the binder resin,
More preferably, 2 to 10 parts by weight is used. If it is less than 0.5 part by weight, the coloring is not sufficient, and if it is more than 40 parts by weight, the charge is not stable due to the conductivity of the pigment and the stability over time is poor.

When producing a black toner, a nigrosine dye or another dark-color positive charge control agent may be used in combination with the polymeric quaternary salt of the present invention.

If necessary, other additives such as waxes may be added to the toner of the present invention, or the surface of the toner may be surface-treated with ultrafine metal oxide powder.

The toner of the present invention can be prepared, for example, by mixing it with a suitable carrier.
It may be a component-based developer. As the carrier, resin-coated glass beads, steel spheres or the like are used when the cascade development method is carried out, and ferrite, pulverized iron, or so-called binder type microcarriers are used when the magnetic brush development method is carried out. On the other hand, the non-magnetic toner can be used as one component by charging it with a developing sleeve or the like. Alternatively, the toner of the present invention itself may be manufactured as an insulating magnetic toner and used as a one-component developer to carry out the magnetic brush development method.

The toner of the present invention is obtained by thoroughly mixing the composition obtained by mixing the various components described above, further mixing until sufficiently uniform, then kneading, cooling, and pulverizing with a pulverizer such as a jet pulverizer. Granules of 5 or less are removed by removing coarse powder and fine powder by classification.
A toner having a particle size of 25 μm and an average particle size of 13 to 14 μm is obtained.

Example 1 component by weight Styrene-acrylic resin 100 (Mn: 10,500, Mw: 184,200, Tg: 60.5 ° C.) carbon black 5 (manufactured by Mitsubishi Kasei Kogyo; MA # 8) Polymer quaternary salt of the present invention (1) 3 (Table 1, Sample 1) Low molecular weight PP wax 2 (manufactured by Sanyo Kasei Co., Ltd .; Viscole 330P) After thoroughly mixing the above mixture, kneading with a twin-screw extruder,
After cooling, coarsely pulverize to a particle size of 2 mm square or less. Next, after finely pulverizing with a jet mill, classification is performed and the average particle size is 13.2 μm.
Aligned to. 2 g of fine particle silica (manufactured by Nippon Aerosil Co., Ltd .; R-972) was thoroughly mixed with 1 kg of the obtained toner using a Henschel mixer. The toner thus obtained is referred to as Toner 1.

Example 2 Component weight part Styrene / acrylic resin 100 (Mn: 12,400, Mw: 156,700, Tg: 62.5 ° C.) Cu-phthalocyanine 6 (manufactured by Dainichiseika; # 4920) Polymer quaternary salt of the present invention (2) 3 (Sample 1 in Table 1) Low molecular weight PP wax 2 (manufactured by Sanyo Kasei Co., Ltd .; Viscole 330P) The above components were used in the same manner as in Example 1 to have an average particle size of 13.8 μm.
Toner was obtained. Fine silica (R-972) 0.2%
Then, the surface of the toner is treated to obtain toner 2.

Example 3 Cu-phthalocyanine used in Example 2 (manufactured by Dainichiseika; #
4920) instead of Lake Red C (Dainichi Seika) 5
3 parts by weight of (3) (Sample 3 in Table 1) was used in place of the high molecular weight quaternary salt (2) to form a toner, and the average particle size was
13.2 μm of toner was obtained. Thereafter, similar processing was performed to obtain Toner 3.

Example 4 Instead of the polymeric quaternary salt (2) used in Example 2, (4)
Using 3 parts by weight of (Sample 4 in Table 1), a toner having an average particle diameter of 13.5 μm was obtained, and the same treatment as described below was performed.
Toner 4 was obtained.

Examples 5 to 8 In the same manner, toners were prepared by using (5) to (8) (Samples 5 to 8 in Table 1) instead of the polymeric quaternary salt (2) of Example 2. , Toners 5 to 8 were obtained.

Example 9 (evaluation of toner) Production component of carrier Weight part Styrene / acrylic resin 100 (Goodyear Co .; Priorite ACL) Magnetic powder (Toda Kogyo; EPT-1000) 200 Carbon black 4 (Mitsubishi Kasei Co., Ltd.) Manufactured by MA # 8) Silica (manufactured by Nippon Aerosil Co., Ltd .; # 200) After thoroughly mixing 1.5 or more of the mixture, kneading with a three-roll mill,
After cooling, it was roughly pulverized, then pulverized with a hammer mill, and then classified to prepare an average particle size of 60 μm.

8 parts by weight of the toners obtained in Examples 1 to 8 and 92 parts by weight of the microcarrier prepared by the above-mentioned method were put into a plastic bottle, and the mixture was stirred and mixed for 4 hours. The polymeric quaternary salt (1) used in Examples 1 and 2
Comparative Examples 1 and 2 are toners using 3 parts by weight of benzimidazole (manufactured by Wako Pure Chemical Industries, Ltd.) instead of (2).

The above developer was put in EP-450 manufactured by Minolta Camera Co., Ltd. and a running test of 10,000 sheets was performed. The results are shown in Table 2.

Table 2 shows the amount of charge when an iron powder carrier (TEF-V manufactured by Nippon Iron Powder Co., Ltd .; TEF-V) 95 parts by weight and 5 parts by weight of toner were charged in the same manner in place of the microcarriers.

In Table 2, the post-humidity charge amount is as follows:
The charge amount after standing for 3 days in an environment of 85% is shown.

In the evaluation of the printing durability test, the degree of occurrence of fog after copying was judged as follows by developing a blank sheet with proper exposure and comparing this copy with a limit sample; ⊚: No fog at all ◯: There is some fog, but there is no problem in practical use. Δ: Fog is noticeable; X: Practically unsuitable.

EFFECTS OF THE INVENTION The polymeric quaternary salt represented by the general formula (I) of the present invention can be used as a positive charge control agent, and can be optimally used particularly for color toners.

Further, the toner using the quaternary salt which can be represented by the general formula (I) has less scattering and is excellent in environmental stability.

Furthermore, the polymer quaternary salt represented by the general formula (I) is
Since it has excellent thermal stability, it has a good working environment.

Claims (1)

[Claims] 1. A toner containing at least a thermoplastic resin, a pigment and / or a dye, which comprises a high molecular quaternary salt represented by the following general formula (I) as a charge control agent; (In the formula, R ₁ represents a hydrogen atom, a C _{1 to} C ₁₇ alkyl group, or an aryl group, and R ₂ , R ₃ and R ₄ may be the same or different, and each is a hydrogen atom. Or C _{1 to} C
₁₇ represents an alkyl group, X represents a halogen atom, an anion such as sulfonic acid or naphtho-sulfonic acid, and n
Each represents an integer of 2 or more).