JP2824783B2 - Toner for developing electrostatic images - Google Patents

Description

The present invention relates to a toner for developing an electrostatic image for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like.

2. Description of the Related Art As a method for forming a visible image by developing an electric latent image with a toner, an electrostatic printing method, an electrophotographic method, and the like are conventionally known. For example, in electrophotography, U.S. Pat.
No. 297,691, JP-B-42-23910, JP-B-43-
Various methods described in 24748 and the like are well known.
In general, a photoconductive substance is used to form an electric latent image on a photoconductor showing photoconductivity by various means, and then the latent image is developed with toner to obtain a visible image. Then, a powder image is transferred onto paper or the like, and then fixed by heating, pressing, or solvent vapor to obtain a visible image.

Conventionally, carbon black has often been used as a colorant in toners for developing electrostatic images. Further, various dyes and pigments may be used as a charge control agent in such a toner.
For example, copper-phthalocyanine represented by CI Pigment blue 15, copper-phthalocyanine sulfonylamine derivative described in JP-A-52-45931, and CI Pigment Red 48 described in JP-A-60-7435. Is mentioned.

However, when a copper-phthalocyanine or a sulfonylamine derivative of copper-phthalocyanine is used together with carbon black, the toner exhibits a sharp black color with a bluish tint, but the hydrogen group and the sulfone group have a hygroscopic property. Does not provide sufficient chargeability. Also,
When a red dye / pigment is used together with carbon black as in CI Pigment Red 48 described in JP-A-60-7435, the toner becomes reddish and lacks sharpness of an image. Also,
When this pigment is used, the compatibility with the resin is insufficient, so that the dispersibility of the colorant is deteriorated, the coloring power of the carbon black is reduced, and there is a problem that a local charge variation occurs.

[Problems to be Solved by the Invention] An object of the present invention is to solve the above-mentioned problems, to provide a sharp image having a sufficient coloring power, to have excellent compatibility with a resin, and to have a chargeability, particularly to a triboelectric charge. The object of the present invention is to provide a toner for developing an electrostatic image in which the rise of charge in the toner is good.

[Means and Actions for Solving the Problems] That is, the present invention relates to a toner for developing an electrostatic image containing a resin, carbon black, and a pigment represented by the general formula (I) as essential components.

General formula (I) (X _{1 to} X ₄ : -H R, R ': unless However alkylene group having 1 to 5 carbon atoms, all the X ₁ to X ₄ is -H. As the binder resin to be applied to the toner of the present invention, all known resins can be used. -Chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-
Butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethacrylic acid Methyl copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer Styrene-based copolymers such as polymers, styrene-acrylonitrile-indene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, and polyacetic acid Vinyl, poly Tylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorination Paraffin, paraffin wax and the like can be used alone or in combination.

As the carbon black applied to the present invention, any colorable carbon black can be used, and examples thereof include furnace black, channel black, thermal black, and lamp black. The addition amount of carbon black is 2 parts by weight to 13.5 parts by weight with respect to 100 parts by weight of the resin. I will receive it. Also, 1
If it is added in excess of 3.5 parts by weight, sufficient good triboelectric charging cannot be obtained due to the conductivity of carbon black, and the environmental stability of charging will be impaired. Preferably it is 3 to 10 parts by weight, more preferably 3 to 7 parts by weight.

Particularly important as a constituent component of the toner of the present invention is the copper-phthalocyanine compound represented by the general formula (I) described above. As specific examples of the compound represented by the general formula (I), X _{1 to} X ₄ in the formula are: And the like.

This compound, when used with carbon black,
Because of its high compatibility with the binder resin, it is uniformly dispersed and provides a good sharp image to the toner. In addition, since the terminal hydrogen group of the compound is substituted with the terminal groups described in the above a) to d), the chargeability is improved, and poor charging due to moisture absorption can be prevented particularly under high humidity. The amount of the compound represented by the formula (I) to be used is such that the ratio of the compound to carbon black is in the range of 10 to 50 with respect to 100 of carbon black. Ten
If it is less than 50, the compound represented by the formula (I) does not have a sufficient role of controlling the charge. On the other hand, if it exceeds 50, the bluish tint is so strong that the color may shift from black to blue. Preferably it is 20 to 40 with respect to 100 of carbon black.

Further, a charge control agent may be added to the toner of the present invention as needed. For example, when used as a negative toner, a metal chelate of alkyl salicylic acid or the like can be used. When used as a positive toner, a dimethylaminoethyl methacrylate-styrene copolymer or the like can be used.

Further, for a developer in which the toner of the present invention is used, a fluidity modifier such as colloidal silica is added to the toner in an amount of 0.1%.
About 01% to 5% by weight (preferably 0.1% to 2% by weight) may be added.

When a carrier is used for the developer, a conventionally known carrier can be used. For example, surface oxidized or unoxidized iron, nickel, copper, zinc, cobalt, manganese, chromium, rare earth and other metals and alloys or oxides thereof and ferrites composed of the above metals can be used. There are no restrictions.

Further, the system in which the surface of the carrier is coated with a resin or the like,
Particularly preferred as the developer of the present invention. As the method, any conventionally known method such as a method of dissolving or suspending a coating material such as a resin in a solvent, applying the coating material, and attaching the coating material to a carrier, or a method of simply mixing with a powder, can be applied.

Next, a general method for producing the toner of the present invention will be described.

First, a resin, carbon black and a pigment represented by the general formula (I) (in some cases, a charge control agent) are uniformly dispersed by a Henschel mixer or the like, and then melt-kneaded by a kneader, an extruder, a roll mill or the like. Next, the kneaded material is roughly pulverized by a cutter mill, a hammer mill or the like, and further finely pulverized by a jet mill, an I-type mill or the like. The finely pulverized product is classified by a DS and a zigzag classifier, and silica or the like is dispersed in the classified product by a Henschel mixer or the like in some cases.

[Examples] Hereinafter, the present invention will be described in detail with reference to Examples. All parts in the examples are parts by weight.

Example 1 The compound is uniformly dispersed in a Henschel mixer, melt-kneaded in a roll mill, cooled, coarsely crushed using a hammer mill, and then finely crushed by a fine crusher using an air jet method. Classify the resulting fine powder, 1 ~ 20μ
Is selected as the toner. 90 parts of a carrier (Cu-Zn ferrite) was mixed with 10 parts of the toner to prepare a developer. Using this developer, NP-50 having a magnetic brush developing device
00 Copying was performed with a copying machine (manufactured by Canon Inc.) in an environment from high temperature and high humidity to low temperature and low humidity. As a result of measuring the charge amount of the developer by the two-component blow-off method, the dependence on the environment was good (FIG. 1), and the copy obtained was a sharp black image without fog.

Example 2 Specific example of compound [1] in Example 1 In the same manner as in Example 1 except that the above was replaced with Example 1, the chargeability was good (FIG. 1), and a sharp black image was obtained.

Example 3 A toner was produced using the above compound in the same manner as in Example 1,
Colloidal silica was added to the toner in an amount of 1% by weight based on the toner, and a copy was made with a CLC-1 copying machine (manufactured by Canon Inc.). The copy had a very sharp black color without fog.

A durability test was performed with a CLC-copier modified so as to be able to detect the inductance toner concentration. As a result, a clear black image free from fog, dust and the like was obtained even after the durability of 20,000 sheets.

Comparative Example 1 The procedure of Example 1 was repeated except that Compound [1] was replaced by CI Pigm.
A toner and a developer were prepared in exactly the same manner as in Example 1 except that ent blue 15 was changed to 2 parts. Insufficient charging in a high-temperature and high-humidity environment (FIG. 1) caused fogging and toner scattering on the image.

Comparative Example 2 The procedure of Example 1 was repeated except that Compound [1] was replaced by CI Pigm.
A toner and a developer were prepared in exactly the same manner as in Example 1 except that ent Red 48 was changed to 2 parts. Images copied with an NP-5000 copier (manufactured by Canon Inc.) were reddish, noticeable especially in the halftone area, lacked sharpness of the image, and caused unevenness in image density due to local uneven charging. .

Comparative Example 3 A toner and a developer were prepared in the same manner as in Example 1 except that the amount of carbon black was increased to 20 parts by weight and Compound [1] was not used. The charge amount of the toner was low (FIG. 1), and a large amount of fog occurred on the image.

[Effect of the Invention] The present invention relates to a toner for developing an electrostatic image to which a compound [1] is added for the purpose of adjusting the tint and charge amount of a black toner. It is characterized in that characteristics are good and a sharp image is obtained.

[Brief description of the drawings]

FIG. 1 illustrates the measurement result of the charge amount in the two-component blow-off method of the developer.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Kobayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-1-254968 (JP, A) JP-A-57 -26855 (JP, A) JP-A-58-203455 (JP, A) JP-A-58-211161 (JP, A) JP-A-63-170658 (JP, A) (58) Fields investigated (Int. . ^6, DB name) G03G 9/09 CA (STN)

Claims (3)

(57) [Claims] 1. A toner for developing an electrostatic image, comprising a resin, carbon black and a pigment represented by the general formula (I) as essential components. General formula (I) (X _{1 to} X ₄ : -H R, R ': unless However alkylene group having 1 to 5 carbon atoms, all the X ₁ to X ₄ is -H. ] 2. The electrostatic image developing toner according to claim 1, wherein the total colorant content of the carbon black and the pigment represented by the general formula (I) is 15 parts by weight or less based on 100 parts by weight of the resin. 3. The method according to claim 1, wherein the addition ratio of the carbon black to the pigment represented by the general formula (I) is from 100/10 to 100/50.
Or the toner for developing an electrostatic image according to 2.