JP2797264B2 - Yellow toner for electrophotography - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a toner for developing an electrostatic latent image formed in electrophotography, electrostatic printing, electrostatic recording, and the like. More specifically, the present invention relates to a negatively chargeable yellow (YELLOW) toner used for full-color electrophotography and the like.

Prior art U.S. Pat.
Various methods are described in JP-A-23910 and JP-B-43-24748, but generally, a photoconductive substance is used, and an electric latent image is formed on a photoconductive support by various means. Then, the latent image is developed with toner to obtain a visible image, or, if necessary, a powder image is transferred to paper or the like and then fixed by heating, pressing, or solvent vapor to form a visible image. What you get. In order to obtain a multicolor image of color, as described in U.S. Pat. No. 2,962,374 or the like, at least the image is separated into three color signals of yellow, magenta, and cyan and exposed, and Is developed multiple times using color toners such as yellow, magenta, and cyan,
The multi-color image is obtained by superimposing the toner images.

Such toners, like black toners that are widely used, are excellent in chargeability, have little environmental dependency, have little deterioration with repeated use, and have good fixability. Various characteristics are required. On the other hand, characteristics such as good spectral reflection characteristics of the toner, good color mixing properties, and high transparency, which are unique to full-color toners, must be provided as essential properties.

However, materials such as colorants that can be used to improve hue, saturation, and transparency are limited, and the chargeability and durability in continuous use cannot be sufficiently satisfied. There is a constant demand for improvements.

Conventionally, as a colorant for yellow toner, CI Pigmen
Monoazo pigments represented by t Yellow 1, CI Pigment Yellow 3, etc., CI Pigment Yellow 12, CI Pigment Ye
Disazo pigments such as llow 13 etc., CISolvent Y
Tartrazine dyes such as ellow 16 are used, but disazo pigments are widely used due to their high hue and high stability to heat and light.

However, when a disazo dye is used as a coloring agent, it has been difficult to control the chargeability. In particular, the image density is reduced due to an increase in the amount of charge under low humidity, and there is a drawback that environment dependency is large. Further, the durability in continuous use was short, and it was not satisfactory.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrophotographic yellow toner having excellent spectral reflection characteristics, color mixing properties, transparency, low environmental dependency, and excellent chargeability in view of the conventional disadvantages. It is in. Still another object is to provide an electrophotographic yellow toner having excellent durability and stable performance even when used repeatedly for a long period of time.

Another object of the present invention is to provide a yellow toner for electrophotography which shows good fixability even at a low temperature and does not fuse an image to a vinyl chloride sheet.

Structure The electrophotographic yellow toner of the present invention comprises, as a toner binder resin, (a) a compound classified as CI Pigment Yellow 17, (b) a compound classified as CISolvent Yellow 21, or a compound classified as CISolvent Yellow 61 , (C) a metal salt of salicylic acid and / or a metal salt of a salicylic acid derivative.

Further, the toner binder resin is a polyester resin synthesized from a bisphenol-type diol and a polycarboxylic acid, and the polyester resin has an acid value of 5 [KOHmg / g].
And the hydroxyl value is 30 [KOHmg / g] or less, particularly excellent results can be obtained.

Particularly important as a component of the toner of the present invention is C.I.
A compound classified as I. Pigment Yellow 17, and
(B) a compound classified as CISolvent Yellow 21 or 61; and (c) a metal salt of salicylic acid and / or a metal salt of a salicylic acid derivative.

Examples of compounds classified as CI Pigment Yellow 17 of the present invention include Permanent Yellow GG02 (manufactured by Hoechst), Symuler Fast Yellow 8 GTF (manufactured by Dainippon Ink and Chemicals, Inc.), Sumikaprint Fast Yellow GBFN (Sumitomo Chemical Industries, Ltd.) And the like). CIPigmen
Compounds classified as Yellow 17 have better dispersibility in the binder resin for toner than other disazo pigments (benzidine pigments), and therefore have high coloring power and excellent toner transparency. Becomes The amount used is generally in the range of 1 to 10% by weight, preferably 2 to 5% by weight, based on the toner binder resin. If it is less than 1% by weight, the coloring power is insufficient, and if it is more than 10% by weight, the chargeability is affected, which is not preferable.

Examples of compounds classified as CISolvent Yellow 21 of the present invention include Vali Fast Yellow # 3105 (manufactured by Orient Chemical Industry Co., Ltd.), Zapon Fast Yellow R (manufactured by BASF), and the like. Invention CISolvent
Examples of compounds classified as Yellow 61 include Aizen Spi
lon Yellow RH (manufactured by Hodogaya Chemical Industry Co., Ltd.) and the like.

These compounds classified into CISolvent Yellow 21 or 61 are classified into 1: 2 type metal complex dyes in chemical structure. Since these compounds are dyes, their dispersibility in the toner binder resin is very good.
When used in combination with a compound classified as ent Yellow 17, it is possible to improve chargeability, durability in continuous use, and environmental dependency without impairing good hue and transparency. The amount of the compound classified as CISolvent Yellow 21 or 61 can be determined in consideration of other conditions such as the chargeability of the binder resin, the production method including the dispersion method, and the chargeability of other additives, Almost against toner binder resin
It is in the range of 0.1-5 wt%, preferably 0.5-3 wt%. 0.1w
If it is less than t%, the charge control effect is small, and if it is 5 wt% or more, the desired hue may be impaired.

Further, by using the above two compounds (a) and (b) in combination with the metal salt of salicylic acid and / or the metal salt of a salicylic acid derivative of (c), more excellent toner properties (chargeability and continuous use) can be obtained. Durability and environment dependency)
Can be obtained.

The metal salt of salicylic acid and / or the metal salt of a salicylic acid derivative of the present invention is preferably a compound represented by the following general formula.

(However, R ¹ , R ² , and R ³ are preferably hydrogen or an alkyl group having 1 to 10 carbon atoms or an allyl group. Here, R ¹ , R ² ,
And R ³ may be the same or different at the same time. Also,
Me is any metal selected from zinc, nickel, cobalt, lead and chromium, of which zinc is particularly desirable. The metal salt represented by the general formula is CLARK, JLKao,
H. (1948) J. Amer. Chem. Soc. 70, 2151. For example, 2 mol of salicylic acid sodium salt (including the sodium salt of a salicylic acid derivative) and 1 mol of zinc chloride are added to a solvent, mixed, heated and stirred to obtain a zinc salt. . Metal salts other than zinc salts can also be produced according to the above method.

The metal salt of salicylic acid and / or the metal salt of a salicylic acid derivative is a white crystal and has good dispersibility in a binder resin, and therefore does not substantially show coloring in a toner. A metal salt of salicylic acid and / or a metal salt of a salicylic acid derivative gives more favorable toner properties when used in combination with a compound classified as CISolvent Yellow 21 or 61. Its usage is CI Pigm
ent Yellow 17 addition amount ・ CISolvent Yellow 21 or
It can be determined in consideration of other conditions such as the addition amount of 61, the manufacturing method including the chargeability of the binder resin, the dispersion method, and the chargeability of other additives.
It is in the range of 0.1-5 wt%, preferably 0.5-3 wt%. 0.1w
If it is less than t%, the charge control effect is small, and if it is 5 wt% or more, the transparency of the toner may be impaired.

As the binder resin of the toner of the present invention, a polyester resin synthesized from a bisphenol-type diol and a polycarboxylic acid can be used.

Polyester resin synthesized from bisphenol-type diol and polycarboxylic acid has excellent transparency of resin itself,
In addition, since the fixing property at a low temperature and the hot offset resistance can be achieved at a high level, it is suitable as a binder resin for a color toner.

Examples of the bisphenol-type diol used in the present invention include polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene (2) -2,2-bis (4- (Hydroxyphenyl) propane, polyoxystyrene (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxybutylene (2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3 ) -Bis (4-hydroxyphenyl) thioether, polyoxypropylene (2) -2,2-bis (4-cyclohexanol) propane, polyoxyethylene (2) -2,6-dichloro-4-hydroxyphenyl, poly Oxyethylene (2,5) -p, p-bisphenol, polyoxybutylene (4) -bis (4-hydroxyphenyl) ketone, Oxyethylene-2,2-bis (4-hydroxyphenyl) propane, oxypropylene-2,2-bis (4-hydroxyphenyl) propane, and the like.

If necessary, as other alcohol components, for example, ethylene glycol, propylene glycol, 1,4
-Aliphatic polyols such as butanediol, 1,5-pentanediol, 1,6-hexanediol, glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol can be used.

Examples of the polycarboxylic acid used in the present invention include, for example, derivatives of divalent aromatic carboxylic acids such as phthalic acid, isophthalic acid, phthalic anhydride, terephthalic acid, and esters thereof. As polycarboxylic acids, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4 , 5-benzenetetracarboxylic acid and their anhydrides and esters. Examples of the divalent aliphatic carboxylic acid include, for example, maleic acid, fumaric acid, succinic acid, adipic acid,
Sebacic acid, malonic acid and divalent organic acid monomers obtained by substituting these with saturated or unsaturated hydrocarbon groups having 8 to 22 carbon atoms, anhydrides thereof, dimers of lower alkyl esters and linoleic acid, And other divalent organic acid monomers.

Further, the acid value of the polyester resin is 5 [KOHmg / g].
By using a compound having a hydroxyl value of 30 [KOHmg / g] or less, better toner characteristics can be obtained. The polyester resin has an acid value of 5 [KOHm
g / g] or more, the negative chargeability of the resin itself becomes strong, and the charge amount increases under low humidity. Hydroxyl value is 30
Above [KOHmg / g], the decrease in charge amount under high humidity becomes large. In addition, an increase in the number of low molecular weight polymers inevitably causes problems such as offset resistance and blocking resistance.

The acid value / hydroxyl value of the polyester resin in the present invention is measured according to the method of JIS K0070.

The toner of the present invention may contain a known toner resin for the purpose of improving the properties of the toner such as fluidity, non-filming property, pulverizability, charging property and fixing property. For example, polystyrene, poly p-styrene, a homopolymer of styrene and its substituted body such as polyvinyl toluene,
Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-methyl acrylate copolymer, styrene-
Ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-methyl methacrylate copolymer,
Styrene-ethyl methacrylate copolymer, styrene-
Butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer Polymers, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-based copolymer such as styrene-maleic acid ester copolymer, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, Polyethylene, polypropylene, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or aliphatic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin I can box and be used alone or in combination.

These resins, as long as the effects of the present invention are not impaired,
It can be contained at a content of 30% by weight or less of the binder.

Also, if necessary, fluidizing agents such as colloidal silica, titanium oxide, metal oxides such as aluminum oxide,
An abrasive such as silicon carbide and a lubricant such as a fatty acid metal salt may be contained.

The toner of the present invention can be used either as a one-component developer or as a two-component developer by mixing with a carrier. When used as a two-component developer, conventionally known carriers can be used. For example, iron powder having a particle size of about 20 to 200 μm, nickel powder, ferrite powder, magnetite powder, glass beads,
Alternatively, using this as a core material, a fluororesin on its surface,
A resin coated with a resin such as a silicone resin, a styrene resin, or an acrylic resin can be used.

Hereinafter, the present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. In the description, “parts” means parts by weight.

EXAMPLES Example 1 Production of Polyester Resin 7 mol of terephthalic acid, 2 mol of trimellitic acid and 9 mol of polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane are condensed by a conventional method. At least a polyester resin was synthesized. Careful attention was paid so that each monomer did not distill or escape during the synthesis, and when distilling or escaped, only that amount was added on the way. The obtained resin had an acid value of 3.5 (KOHmg / g) and a hydroxyl value of 24.2 (KOHmg / g).
g].

[Production of toner]

100 parts of the above polyester 100 parts Permanent Yellow GG02 5 parts (manufactured by Hoechst) Vali Fast Yellow # 3105 1 part (manufactured by Orient Chemical Industry Co., Ltd.) Charge control agent 1 part (3,5-di-t-butylsalicylate chromium complex compound) ) The mixture of the above composition is melt-kneaded, cooled, pulverized, classified,
A yellow toner having a particle size of 5 to 20 μm was obtained.

[Live-action test]

5 parts of the toner prepared as described above was mixed with 95 parts of a redox iron powder carrier by a ball mill to prepare a developer.

Next, the above developer was set in an IMAGIO320 digital copying machine manufactured by Ricoh Co., Ltd., and an image test was performed. As a result, a good image having good solid gradation and no fog was obtained. When a copied image was repeatedly formed, the image did not change even after 50,000 sheets of image were output.

Also, when the charge amount of the toner was measured by a blow-off method, the initial charge amount was −20.6 μC / g, and the charge amount of the toner after running 50,000 sheets was 17.2 μC / g, which was almost the same as the initial value. Was. Also, images equivalent to normal humidity were obtained in a high humidity environment of 35 ° C. and 90% RH and in a low humidity environment of 10 ° C. and 15% RH.

Example 2 [Production of Toner] The procedure was performed except that terephthalic acid was 7 mol, trimellitic acid was 2 mol, polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane was 8.84 mol, and glycerin was 0.16 mol. A polyester resin was synthesized in the same manner as in Example 1. The obtained resin had an acid value of 4.3 [KOHmg / g] and a hydroxyl value of 19.7 [KOHmg / g].

80 parts of the above polyester 80 parts Styrene-methacrylate 20 parts Copolymer Symuler Fast Yellow 8GTF 5 parts (manufactured by Dainippon Ink and Chemicals, Inc.) Zapon Fast Yellow R (manufactured by BASF) 2 parts Charge control agent 1 part (3, 5-Di-t-butylsalicylate chromium complex compound) The mixture having the above composition is melt-kneaded, cooled, pulverized, and classified.
A yellow toner having a particle size of 5 to 20 μm was obtained.

[Actual Photo Test] 3 parts of the toner prepared as described above and 97 parts of the irregular ferrite carrier were mixed by a ball mill to prepare a developer.

Next, the above developer was set in an IMAGIO320 digital copying machine manufactured by Ricoh Co., Ltd., and an image test was performed. As a result, a good image having good solid gradation and no fog was obtained. When a copied image was repeatedly formed, the image did not change even after 50,000 sheets of image were output.

When the charge amount of the toner was measured by the blow-off method, the initial charge amount was −18.3 μC / g, and the charge amount of the toner after running 50,000 sheets was −15.8 μC / g, which is almost the same as the initial value. Did not. Also, images equivalent to normal humidity were obtained in a high humidity environment of 35 ° C. and 90% RH and in a low humidity environment of 10 ° C. and 15% RH.

Comparative Example 1 [Production of Toner] 100 parts of polyester of Example 1 5 parts of Permanent Yellow GG02 (manufactured by Hoechst) 1 part of charge control agent (chromium complex compound of 3,5-di-t-butylsalicylate) Melt kneading, cooling, pulverizing, classifying,
A yellow toner having a particle size of 5 to 20 μm was obtained.

[Live-action test]

5 parts of the toner prepared as described above and 95 parts of the carrier of Example 1 were mixed by a ball mill to prepare a developer.

Next, the above developer was set in an IMAGIO320 digital copying machine manufactured by Ricoh Co., Ltd., and an image test was performed. As a result, the image density was low, and sufficient image density could not be obtained even when the developing bias was adjusted. Further, when a copied image was repeatedly formed, fogging and the like occurred rapidly after about 10,000 copies of the image were formed, and the image deteriorated. When the carrier was separated from the developer and observed, the toner was fused on the carrier surface.

When the charge amount of the toner was measured by a blow-off method, the initial charge amount was −48.0 μC / g, and the charge amount of the toner after running 10,000 sheets was −12.9 μC / g. In addition, the toner has a charge amount of −8.1 μC / g in a high humidity environment of 35 ° C. and 90% RH, and has a charge amount of −60.7 μC / g in a low humidity environment of 10 ° C. and 15% RH. It was bad.

Comparative Example 2 [Production of Toner] 100 parts of polyester of Example 1 Permanent Yellow GG02 5 parts (manufactured by Hoechst) Vali Fast Yellow # 3105 3 parts (manufactured by Orient Chemical Industry Co., Ltd.) A mixture having the above composition was melt-kneaded and cooled. , Crush, classify,
A yellow toner having a particle size of 5 to 20 μm was obtained.

[Live-action test]

95 parts of the carrier of Example 1 and 5 parts of the toner prepared as described above were mixed by a ball mill to prepare a developer.

Next, the above developer was set on an IMAGIO320 digital copier manufactured by Ricoh Co., Ltd., and an image test was performed. As a result, the image was fogged, solid, and sharp. Further, when a copy image was repeatedly formed, the image was output on about 10,000 sheets, and toner scattering in the copying machine became severe.

Further, when the charge amount of the toner was measured by a blow-off method, the initial charge amount was −9.9 μC / g, and the charge amount of the toner after running 10,000 sheets was −7.5 μC / g.

Example 3 [Production of Toner] 100 parts of polyester produced in Example 1 Permanent Yellow GG02 5 parts (manufactured by Hoechst) Aizen Spilon Yellow RH 1 part (manufactured by Hodogaya Chemical Industry Co., Ltd.) Charge control agent 1 part (3, 5-Di-t-butylsalicylate chromium complex compound) The mixture having the above composition is melt-kneaded, cooled, pulverized, and classified.
A yellow toner having a particle size of 5 to 20 μm was obtained.

[Live-action test]

5 parts of the toner prepared as described above was mixed with 95 parts of a redox iron powder carrier by a ball mill to prepare a developer.

Next, the above developer was set in an IMAGIO320 digital copying machine manufactured by Ricoh Co., Ltd., and an image test was performed. As a result, a good image having good solid gradation and no fog was obtained. When a copied image was repeatedly formed, the image did not change even after 50,000 sheets of image were output.

When the charge amount of the toner was measured by a blow-off method, the initial charge amount was −22.1 μC / g, and the charge amount of the toner after running 50,000 sheets was −20.3 μC / g, which is almost the same as the initial value. Did not. Also, images equivalent to normal humidity were obtained in a high humidity environment of 35 ° C. and 90% RH and in a low humidity environment of 10 ° C. and 15% RH.

Example 4 [Production of toner] 80 parts of the polyester produced in Example 2 20 parts of styrene-methacrylate copolymer Symuler Fast Yellow 8GTF 5 parts (manufactured by Dainippon Ink and Chemicals, Inc.) 1 part of Aizen Spilon Yellow RH ( Hodogaya Chemical Industry Co., Ltd.) Charge control agent 1 part (3,5-di-t-butylsalicylic acid chromium complex compound) The mixture having the above composition is melt-kneaded, cooled, classified, and 5 to 20%.
A yellow toner having a particle size of μm was obtained.

[Live-action test]

3 parts of the toner prepared as described above and 97 parts of the irregular ferrite carrier were mixed by a ball mill to prepare a developer.

Next, the above developer was set in an IMAGIO320 digital copying machine manufactured by Ricoh Co., Ltd., and an image test was performed. As a result, a good image having good solid gradation and no fog was obtained. When a copied image was repeatedly formed, the image did not change even after 50,000 sheets of image were output.

When the charge amount of the toner was measured by the blow-off method, the initial charge amount was −19.8 μC / g, and the charge amount of the toner after running 50,000 sheets was −17.4 μC / g, which is almost the same as the initial value. Did not. Also, images equivalent to normal humidity were obtained in a high humidity environment of 35 ° C. and 90% RH and in a low humidity environment of 10 ° C. and 15% RH.

Comparative Example 3 [Production of Toner] 100 parts of polyester of Example 1 5 parts of Permanent Yellow GG02 (manufactured by Hoechst) 1 part of charge control agent (chromium 3,5-di-t-butylsalicylate complex compound) Melt kneading, cooling, pulverizing, classifying,
A yellow toner having a particle size of 5 to 20 μm was obtained.

[Live-action test]

5 parts of the toner prepared as described above and 95 parts of the carrier of Example 1 were mixed by a ball mill to prepare a developer.

Next, the above developer was set in an IMAGIO320 digital copying machine manufactured by Ricoh Co., Ltd., and an image test was performed. As a result, the image density was low, and sufficient image density could not be obtained even when the developing bias was adjusted. Further, when a copied image was repeatedly formed, fogging or the like was suddenly generated after about 10,000 images were output, and the image quality deteriorated. When the carrier was separated from the developer and observed, the toner was fused on the carrier surface.

When the charge amount of the toner was measured by a blow-off method, the initial charge amount was −48.0 μC / g, and the charge amount of the toner after running 10,000 sheets was −12.9 μC / g. In addition, the toner has a charge amount of −8.1 μC / g in a high humidity environment of 35 ° C. and 90% RH, and has a charge amount of −60.7 μC / g in a low humidity environment of 10 ° C. and 15% RH. It was bad.

Comparative Example 4 [Production of Toner] 100 parts of polyester of Example 1 Permanent Yellow GG02 5 parts (manufactured by Hoechst) Aizen Spilon Yellow RH 1 part (manufactured by Hodogaya Chemical Industry Co., Ltd.) Crush, classify,
A yellow toner having a particle size of 5 to 20 μm was obtained.

[Live-action test]

95 parts of the carrier of Example 1 and 5 parts of the toner prepared as described above were mixed by a ball mill to prepare a developer.

Next, the above developer was set in an IMAGIO320 digital copier manufactured by Ricoh Co., Ltd., and an image test was performed. As a result, the image was fogged, solid, and sharp. Further, when a copied image was repeatedly formed, the image was output on about 10,000 sheets, and toner scattering in the copying machine became severe.

When the charge amount of the toner was measured by a blow-off method, the initial charge amount was −10.5 μC / g, and the charge amount of the toner after running 10,000 sheets was −7.2 μC / g.

Effects As described above, according to the present invention, a high-quality image excellent in solid gradation can be obtained. Even after continuous copying, an image having the same quality as the initial image can be obtained, there is no change in the negative charge amount, there is little environmental change, and a clear image can be obtained.
In addition, a good image can be obtained from a low temperature, exhibiting good fixability and having no fusion to a vinyl chloride sheet.

Claims (3)

(57) [Claims] (1) CI Pigment Ye is contained in a toner binder resin.
Compound classified as llow 17, (b) CISolvent Yello
w Compound classified as 21 or CISolvent Yellow
A yellow toner for electrophotography, comprising: a compound classified into No. 61; and (c) a metal salt of salicylic acid and / or a metal salt of a salicylic acid derivative. 2. The yellow toner for electrophotography according to claim 1, wherein said toner binder resin is a polyester resin synthesized from a bisphenol-type diol and a polycarboxylic acid. 3. The polyester resin having an acid value of 5 [KOHmg /
g) or less and a hydroxyl value of 30 [KOHmg / g] or less.