JPH0341475A - Yellow toner for electrophotography - Google Patents

Abstract

PURPOSE:To obtain the yellow toner having various good characteristics, such as optical characteristics and electrostatic charge characteristics by incorporated a specific compd. into a binder resin. CONSTITUTION:The yellow toner for electrophotography having the various good characteristics including enhanced light transmittability, spectral reflecting characteristic, affinity of a dye, pigment and a binder resin, electrostatic charge characteristic, and fastness to light and heat is obtd. when the compd. expressed by general formula I is incorporated into the binder resin. In the formula, B: a p-phenylene group which may have a substituent, R<1>, R<2>: respectively a hydro gen atom, substd. or unsubstd. alkyl group, allyl group or substd. or unsubstd. phenyl group; R<1> may form a heterocyclic 6-membered ring integrally with a phenylene group B and nitrogen atom or may form a heterocyclic 5-membered or 6-membered ring integrally with a nitrogen atom.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a color toner for electrophotography, and more particularly to a yellow toner for electrophotography containing a specific compound.

(Prior art) The electrophotographic method is described in U.S. Patent No. 22971,97,
72-2.3910 Publication Button and Special Publication Show 1I3-u4'
Button b1 Generally, an electrical latent image of electrostatic charge is formed on a photoreceptor containing a photoconductive material by various means, and then the latent image is applied with toner. After developing as a powder image and transferring the powder image to paper or the like as necessary, it is fixed by heating, pressure, solvent vapor, or the like.

In addition, in recent years, the electrostatic latent image of the document is formed by exposing it to spectral light, and this is developed with color toner of each color to obtain a colored copy image, or the copy images of each color are superimposed to form a full-color copy image. A color copying method for obtaining copied images has been put into practical use, and color toners such as neutral yellow, magenta, and cyan are manufactured by dispersing dyes and/or pigments of each color in a binder resin. .

The toner is made by dispersing coloring agents such as dyes and pigments in resin such as polyester and finely pulverizing the particles to about 30 μm. or mixed with a carrier material such as fur.

(Problems to be Solved by the Invention) However, it has been difficult for conventional color toners to satisfy the various performances required of color toners.

In other words, conventional color toners (1) lack light transmittance, making color reproduction difficult when overprinting multiple colors, and overprinting (OHP).
A good transparent image cannot be obtained when creating a transparent range.

(2) Good hue and color cannot be obtained because the spectral reflection characteristics are not good.

(3) Due to insufficient fastness to light and heat, the color of the copied image fades when left unused.

(4) Due to the low affinity between dyes and pigments and binder resin,
The dyes and pigments migrate to the photoreceptor, reducing its performance.

(5) Due to poor charging characteristics, the color balance deteriorates as the number of copies increases, and defects such as capri density changes occur on images.

Such problems were occurring.

As a result of intensive studies to solve these problems, the present inventors have found that by using a compound represented by a specific structural formula, the above problems can be solved and an excellent toner that satisfies various required characteristics in a well-balanced manner can be created. The present invention was achieved by learning that the following can be obtained.

(Means for Solving the Problems) That is, the gist of the present invention resides in a yellow toner for electrophotography characterized by containing a compound represented by the following general formula (I) in a binder resin.

(In the formula, B represents a p-)22dine group which may have a substituent, and R1 and R2 are each a hydrogen atom, a substituted or unsubstituted alkyl group, a cycloalkyl group, an allyl group, or a substituted or represents an unsubstituted phenyl group, R1 together with the phenylene group B and the nitrogen atom forms a heterocyclic ring, or together with R2 and the nitrogen atom forms a heterocyclic ring or a six-membered heterocyclic ring. It may be formed. ) The dye compound represented by the general formula (I) used in the present invention will be specifically explained. The substituents of the p-phenylene group represented by B include a C1 to C4 linear or branched alkyl group, a C1 to C4 linear or branched alkoxy group, a fluorine atom, and a chlorine atom. , halogen atoms such as bromine atoms, trifluoromethyl groups, etc., and their substitution positions are not particularly limited, and the number of substituents may range from 7 to 7.
A particularly preferred substituent is a methyl group at the meta-position of the amino group.

As the alkyl group represented by R1 and R2, for example,
Examples include C1 to C8 linear or branched alkyl groups, and examples of substituted alkyl groups include λ-hydroxyethyl group, 3-hydroxypropyl group, q-hydroxybutyl group, 4-hydroxy-propyl group, etc. Hydroxy-substituted alkyl groups, carboxy-substituted alkyl groups such as carboxymethyl group, cocarboxyethyl group, 3-carboxypropyl group, cyano-substituted alkyl groups such as 2-cyanoethyl group and cyanomethyl group, 4-amino-ethyl group, etc. Amino-substituted alkyl group, 2-chloroethyl group, 3-chloropropyl group, dichloropropyl group, λ, 2,2-
Halogen-substituted alkyl groups such as trifluoroethyl group, phenyl-substituted alkyl groups such as benzyl group, p-chlorobenzyl group, and euphenylethyl group, 4-methoxyethyl group, coethoxyethyl group, 2-(n) propoxy Ethyl group, isopropoxyethyl group, n-butoxyethyl group1. :z-(iso)butoxyethyl group, 4(nee-ethylhexyloxy)ethyl group, 3methoxypropyl group, q-methoxybutyl group, 4-
alkoxy-substituted alkyl groups, such as methoxypropyl groups,
X-(X-methoxyethoxy)ethyl group, 2-(2-ethoxyethoxy)ethyl group, '(' (+)propoxyethoxy)ethyl group, x-(s-(iso
) Propoxyethoxy)ethyl group, 2-(2-(n)
butoxyethoxy)ethyl group, 2 (2-(iso)
alkoxyalkoxy-substituted alkyl groups such as butoxyethoxy)ethyl group, 2-(2-C2-ethylhexyloxy)ethoxy)ethyl group, 4-allyloxyethyl group, cofdinoxyethyl group, 1,2-benzyloxyethyl group, etc. Substituted alkyl group, acyloxy-substituted alkyl group such as niacetyloxyethyl group, nipropionyloxyethyl group, 2-(n)butyryloxyethyl group 1.2-(iso)butyryloxyethyl group, nitrifluoroacetyloxyethyl group group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, (n) propoxycarbonylmethyl group, (iso)70 poxycarbonylmethyl group, (n) butoxycarbonylmethyl group, (1
sO) butoxycarbonylmethyl group, nee-ethylhexyloxycarbonylmethyl group, benzyloxycarbonylmethyl group, furfuryloxycarbonylmethyl group, tetrahydrofurfuryloxymethyl group, neemethoxycarbonylethyl group, 2-ethoxycarbonylethyl group,
u - (n) propoxycarbonyl x f /l/
group, 2-(1so)7'lopoxycarbonylethyl group, 2-(n)ph)oxycarbonylethyl group, 2-(
iso)butoxycarbonylethyl group 1.2-(,2-
ethylhexyloxycarbonyl)x -F- group, r
- Substituted or unsubstituted alkoxycarbonyl-substituted alkyl groups such as benzyloxycarbonylethyl group, neefurfurylcarbonylethyl group, 4-methoxycarbonyloxyethyl group, niethoxycarbonyloxyethyl group 1,1-(n)propoxycarbonyloxy x
-F-ru group 1.2-(iso) fropoxycarbonyloxyethyl group 1.2-(n)butoxycarbonyloxyethyl group, 2-(iso)butoxycarbonyloxyethyl group 1.2-(,2-ethyl Substituted or unsubstituted alkoxycarbonyloxy-substituted alkyl groups such as hexyloxycarbonyloxy)ethyl group, nifurfuryloxycarbonyloxyethyl group, nifurfuryloxycarbonyloxyethyl group, and heteroaryl groups such as furfuryl group and tetrahydrofurfuryl group. Examples include ring-substituted alkyl groups.

The substituted phenyl group represented by R+ and R2 has a C1 to C8 linear or branched alkyl group as a substituent, or a C1 to C4 linear or branched alkoxy group. Examples include those having halogen atoms such as 7 atoms, chlorine atoms, and bromine atoms, and those having nitro groups, cyan groups, and trifluoromethyl groups.

Examples of the cycloalkyl group represented by R1 and R2 include a, a cyclopentyl group, and a cyclohexyl group.

Particularly advantageous R1 and R2 include C3 to C6 linear or branched alkyl groups, 4-hydroxyethyl groups, 4-cyanoethyl groups, suchloroethyl groups, benzyl groups, 2-phenylethyl groups, ;z −(c, −c
4-alkoxy)ethyl group, aryloxyethyl group,
2-pencyloxyethyl group, u-(C, ~C4 alkoxycarbonyl) ethyl group, 4-acetyloxyethyl group, 2- (C, ~C4 alkoxycarbonyloxy)
Examples include ethyl group and allyl group.

Complex S formed by R1, R2 and nitrogen atoms together
Examples of membered rings and complex membered rings include the following.

Examples of dyes in which 10 forms a 6-membered hetero ring include the following.

5 (wherein B and R2 represent the same meanings as above, R3, R
4 and R5 represent a hydrogen atom or a methyl group) More specific examples of the dyes represented by the above general formula (II) include those shown in Table 7.

These dyes can be prepared according to the following general formula (In
) (wherein B, R' and R2 represent the same meanings as above) is reacted with malononitrile in an inert solvent such as methanol, ethanol, propatool, acetone, N,N-dimethylformamide, etc. It can be manufactured by

Table/3 4- The coloring agent to be contained in the yellow toner of the present invention is not limited to the specific examples listed above, but a mixture of two or more compounds represented by the above-mentioned pattern (I). It is also possible to use it as Further, compounds other than these compounds may be used in combination as a coloring agent, as long as the desired effects produced by using the compounds are not impaired. Furthermore, the compound can be mixed with toners of other colors and used for color improvement.

On the other hand, the binder resin for the yellow toner of the present invention can be selected from a wide range including known ones, but colorless and transparent ones are preferred, such as polystyrene,
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 acrinoate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer) styrene-phenyl acrylate copolymer, etc.), styrene-methacrylate ester copolymer (
Styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate copolymer, etc.), styrene-α-methyl chloroacrylate copolymer and styrene resins such as styrene-acrylonitrile-acrylic ester copolymers (styrene-rich or styrene-substituted monopolymers or copolymers), vinyl chloride resins, rosin-modified maleic acid resins, phenolic resins, epoxy resin, polyester resin, low molecular weight polyethylene, low molecular weight polypropylene, ionomer resin,
Examples include polyurethane resins, silicone resins, ketone resins, ethylene-ethyl acrylate copolymers, xylene resins, and polyvinyl butyral resins, among which particularly preferred resins for use in the present invention include styrene resins, saturated or unsaturated polyester resins, and Examples include epoxy resin. However, the above resins are not limited to being used alone, but four or more types can also be used in combination.

The total amount of the colorant added to the toner is preferably 7 to 30 parts by weight, and particularly preferably 70 to 70 parts by weight, based on 100 parts by weight of the binder resin. If the amount added is too small, the coloring effect as a yellow color will be poor, and if it is too large, the fixing properties will be poor and the moldability will tend to be poor.Toner charge control is performed by the binder resin and dye/pigment itself. However, if necessary, a chargeability control agent that does not cause problems in color reproduction may be used in combination. As the positive chargeability control agent, a basic/electron-donating substance such as a grade ammonium salt, and as the negative chargeability control agent, an acidic or electron-withdrawing substance such as metal chelates or metal-containing dyes may be appropriately selected and used. good.

7 The amount of the charge control agent to be added should be determined after considering conditions such as the chargeability of the binder resin, the manufacturing method including the amount and dispersion method of the colorant, and the chargeability of other additives. A suitable amount is 0.1 to 10 parts by weight per 100 parts by weight.

These charge control agents may be used by being mixed into the binder resin, or may be used in the form of being attached to the surface of the toner particles.

Furthermore, the electrical properties of the toner can be controlled by adding solid electrolytes, polymer electrolytes, charge transfer complexes, conductors such as metal oxides such as tin oxide, semiconductors, ferroelectric materials, magnetic materials, etc. .

In addition, it is also possible to add various auxiliary agents such as plasticizers and release agents to the toner for the purpose of adjusting thermal properties, physical properties, etc. The amount added is suitably 0.7 to /θ parts by weight per 100 parts by weight of the binder resin.

Furthermore, toner particles include TlO2, A1□03.5lO2
The fluidity and agglomeration resistance of the toner can be improved by adding fine powders such as, for example, and coating the toner particle surfaces 8 with them. The amount added is preferably 0.1 to 70 parts by weight per 100 parts by weight of the binder resin.

Various conventional toner manufacturing methods can be applied to the toner manufacturing method of the present invention, and examples of the in-shell manufacturing method include the following.

A ball mill, a V-type mixer,
Uniformly disperse using an S-type mixer, Henschel mixer, etc.

Next, the dispersion is melt-kneaded using a double-arm kneader 1 pressure kneader, an extruder roll mill, or the like. The kneaded material is pulverized using a pulverizer such as a hammer mill, cutter mill, jet mill, or ball mill, and the resulting powder is further classified using an air classifier or the like.

The resulting color toner can be mixed with a carrier and used as a developer for electrophotographic copying. As the carrier, it is preferable to use a magnetic material such as a known iron powder carrier or a ferrite carrier, or a carrier coated on the surface thereof in an amount of 70 parts to 700 parts per part of toner.

(Examples) The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. Note that "1 part of each Example P and Comparative Example" represents 1 part by weight.

(Example/) Unsaturated polyester resin / θO part Compound of Charcoal 7 in the above table / 3 parts Zinc salicylate complex compound / part The above materials were melt-kneaded in a hot roll mill, cooled, and coarsely ground using a hammer mill, Then, it was pulverized using an air jet type pulverizer.

The obtained fine powder was classified and the particle size was 3-2! A magenta toner was obtained by selecting iμm particles. 6 parts of this magenta toner was added to 10 θ parts of iron powder and mixed in a V-type mixer to form a developer.

When this developer was used for copying with a dry plain paper electrophotographic copying machine, there was no fog, the spectral reflection characteristics were good, and clear images were obtained. Further, when 20,000 copies were continuously made using this developer, there was no deterioration in the quality of the copied images.

The image density at the initial copying and after copying 20,000 sheets is 8/Is and 8q3, and the amount of charge of this toner is 1/3 μc at the initial copying stage and after copying aooooo sheets.
/g and -/S, 2 μc/g, and the amount of charge was stable.

(Example 2) The same procedure as in Example 1 was obtained except that a styrene n-butyl acrylate copolymer was used instead of the unsaturated polyester resin, and the same results as in Example 2 were obtained.

(Example 3) 11 in the above table/instead of the compound γ in the above table/in
The same procedure as in Example 1 was carried out except that 61 g of the compound was used, and the same results as in Example 2 were obtained.

1 (Example G) Instead of the compound from the above table/Middle 7, use the above table/Middle rot/
Example 1 was carried out in exactly the same manner as Example 1, except that the compound 2 was used, and the same results as Example 1 were obtained.

(Example Example) The weight of the compound with high 7 in the table/middle is the lK in the table/middle above.
When the same procedure as in Example 1 was carried out except that the compound of 7.2 was used, the same results as in Example 2 were obtained.

(Effects of the Invention) As explained above, the yellow toner for electrophotography of the present invention has
It satisfies the properties required of a color toner in a well-balanced manner, and among others, has excellent spectral reflection properties and transparency, and has good charging properties, so that stable images can always be obtained.

Applicant: Mitsubishi Kasei Corporation Representative Patent Attorney Hase No. 1 7 others 22

Claims (1)

[Claims] (1) A yellow toner for electrophotography, which contains a compound represented by the following general formula (I) in a binder resin. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, B represents a p-phenylene group that may have a substituent, and R^1 and R^2 are hydrogen atoms, substituted or unsubstituted, respectively. Represents a substituted alkyl group, cycloalkyl group, allyl group, or substituted or unsubstituted phenyl group, R^
1 is combined with the phenylene group B and the nitrogen atom to form a complex 6
It may form a membered ring, or may be combined with R^2 and a nitrogen atom to form a 5-membered hetero ring or a 6-membered hetero ring. )