JPS59226358A - Electrostatic charge image developing color toner - Google Patents

Abstract

PURPOSE:To enable functional color copying at a low fixing temp., without causing contamination of the offset rear surface, winding trouble, etc., superior in opacifying property, and narrow in electrostatic charging distribution by using a vinyl polymer having a specified mol.wt. distribution as a binder resin. CONSTITUTION:A resin used for the binder of a color toner is a vinyl polymer or copolymer having at least one peak in each of 2 regions of 10<3>-5X10<4> and 10<5>-10<6>mol.wt. distributions measured by the gel permeation chromatography. As a result, the resin has both characteristics; low fixing temp. characterized by a low mol.wt. resin, and little tendency to cause offset chracterized by a high mol.wt. resin, and it is adapted to a heat fixable toner. Therefore, the obtained toner is suitable for functional color copying.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color toner for developing electrostatic images suitable for functional color copying.

[Prior art]

When recording colored images using the electrostatic recording method, color copying is performed using a combination K of color toners of three color separations and three primary colors (or four colors including black) using a subtractive color method to reproduce the primary colors. However, apart from this, so-called funksi H5 is used to display patent characters, figures, etc. on the screen using one or more colors other than black, which is usually used. − method is used. The color toner for funksicolor is distinguished by color,
Since the main purpose is to emphasize the image, it has high opacity and vividness so that even if it is overprinted on other colored images or colored objects, it will form a clear image without being affected by the underlying color. High color development is required.

The commonly used funxional color toner mainly consists of a binder resin and a highly opaque colored pigment.The binder resin, which makes up the majority of the toner, is transferred to a transfer material such as paper and then thermally adhered to it. After being melted and fixed, it solidifies to form a uniform and strong resin layer, which serves to bind the colorant onto the transfer material. To fix the toner image, a contact heating method is generally used in which a heated member such as a heat roller is brought into contact with the toner image to melt the binder resin. Fats are required to have the following properties:

(1) The so-called offset phenomenon, in which molten toner is transferred to a heat fixing roller and stains the next transfer material, should not occur. The off-cent phenomenon tends to occur as the temperature of the heat roller increases, and it can be said that the higher the temperature at which the off-cent phenomenon begins to occur, the more preferable the toner is.

(2) Avoid staining the roller due to transfer to the heat fixing roller and retransfer to the opposing roller, which causes the transfer material to wrap around the roller.

(3) The molten toner should have appropriate fluidity and form a uniform, dense layer with an appropriate thickness after fixing.

In particular, in color toners, the hiding rate of the pigment is lower than in the case of black toners, so a certain layer thickness is required to obtain sufficient color density and hiding properties, so (2)
The fluidity of the molten resin mentioned above is an important point in selecting a grease-resistant material. If the viscosity of the molten resin is too high, non-uniformly dispersed toner is likely to be produced (1) It is also necessary to raise the fixing temperature, and if it is too low, the toner layer will spread during fixing and the layer thickness will decrease, making it difficult to obtain the necessary hiding power. do not have.

(4) Low fixing temperature.

It is desirable that the fixing temperature be as low as possible from the viewpoints of equipment design, handling during use, energy saving, etc.

In general, toners with a low fixing temperature tend to cause an offset phenomenon at low temperatures, and it has been difficult to achieve both a low fixing temperature and a high offset generation temperature in terms of toner performance.

Conventionally, excellent toner binding resins include 1) thermally crosslinkable unsaturated polyester resins, 2) mixtures of polyester resins and vinyl polymers, and 3) trivalent alcohols and/or trivalent carboxylic acids as monomers. Polyester resins with a three-dimensional structure have been proposed, but 1) is difficult to put into practical use due to low fluidity, and 2) has poor compatibility between the two types of resins, resulting in toner charge distribution. 3) tends to spread and cause fog in the image, and 3) has drawbacks such as low offset prevention effect, and although it is satisfactory, the IL was poor.

Vinyl polymers have also been used, but they have the drawback of being prone to offset phenomena.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a color toner that has a low fixing temperature, does not cause phenomena such as off-center backside staining or wrapping, and has excellent hiding properties, and is suitable for functional color copying with a narrow band weight distribution. .

[Structure of the invention]

The above purpose is to use a binder resin with a molecular weight distribution of 103 as measured by gel permeation and chromatography.
This was achieved with a color toner using a polymer or copolymer of vinyl thread monomers, each having at least one maximum in two regions, 5XIO' to 5XIO' and io'' to 106.

The above molecular weight is measured as follows.

“Water/s 200 GPC (Water/s 20
0 Type GPC) (manufactured by Waters), the solvent (tetrahydrofuran) was allowed to flow down at a flow rate of 1 mt/min at a temperature of 25°C, and the concentration was 0.2.
g/1ill! The sample solution of tetrahydrofuran is made into a sample mold and injected into the column in an amount of 4 cm for measurement. The column used here is 10'-1,0'-
A combination of 10'-104 is used.

The monodisperse polystyrene standard sample for setting the calibration curve is polystyrene manufactured by Pressure Chemical Co., Ltd., and has a molecular weight of 1.800,000.860,000°411.
．． 000.160.000.98,200, 51,0
00.

19.800.10,000.4,000 is used.

Vinyl monomers providing the polymer used in the color toner of the present invention include, for example, styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene,
α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-te
rt-butylstyrene 4-konym" ・
--Shishigeju÷, p-n-hexylstyrene, p-n
-Styrene monomers such as pn-7nylstyrene, p-redecylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-7enylstyrene, p-chlorostyrene, and 3,4-dichlorostyrene can be mentioned as preferred. other than this,
For example, ethylenically unsaturated monoolefins such as ethylene/propylene 1-butylene and imbutylene; vinyl halides such as LJX vinyl, vinylidene chloride, vinyl bromide, and vinyl fluoride; vinyl acetate, vinyl propionate, vinyl benzoate, Vinyl esters such as vinyl butyrate, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate/propyl acrylate\n-octyl acrylate, dodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate 1 acrylic Acid stearyl\ac') km2-10 ethyl, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate-ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylate α-methylene such as n-octyl acrylic, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate/dimethylaminoethyl methacrylate, diethylamine ethyl methacrylate, etc. Aliphatic monocarboxylic esters; Acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide; Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; Vinyl methyl ketone, vinyl hexyl ketone, and methyl iso Vinyl ketones such as propenyl ketone; N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, and N-vinylpyrrolidone; vinylnaphthalenes, and others.

Among those obtained using such monomers, styrene-acrylic copolymers are particularly preferred.

The polymer or copolymer having two or more maxima in the molecular weight distribution used in the present invention using the above IP polymer is one selected depending on the type of polymer to be obtained.
A species or more of the above monomers and a polymerization initiator such as benzoyl peroxide are mixed and polymerized under certain reaction conditions,
The chromatic colorant used in the toner of the present invention, which can be obtained by a method such as mixing the obtained polymer with a new monomer and a polymerization initiator and further performing a polymerization reaction, includes various organic and inorganic pigments. Alternatively, there are various dyes, but organic pigments with vivid colors, high light resistance, and high hiding properties are preferable, and examples include the following. (Pigments are shown as C,1, name number and an example of the corresponding product name listed in Color Index 3rd edition 1971 1975 supplement.JC,1, Pigment Red 48:1 (Sumika Print Red C1, Manufactured by Sumikata Chemical Co., Ltd.) C, 1,
Pigment Red 53:1 (Chromov Cool Magenta G, manufactured by Ciba Geigy)
C, 1, Pigment Red 123 (Kaya Set Red E-B, manufactured by Nippon Kayaku ■) C, 1, Pigment Red 139 (Kaya Set Red E-GR, manufactured by Nippon Kayaku ■) C, 1
, Pigment Red 144 (Chromophthal Red BRN, manufactured by Ciba Gaikie)
C, 1, Pigment Red 149 (PV Fast Red B1 Manufactured by Vext Japan Co., Ltd.)
C, 1, Big Men Trend 166 (Chromophthal Scarlenoto R, manufactured by Chipa Geiki) C, 1, Pigment Red 177 (Chromophthal Red A3B, manufactured by Ciba Geigy) C, 1, Pigment Red 178 (Kayaset Red E-GG, manufactured by Nippon Kayaku) C, 1,
Pigment Orange 31 (Chromatar Orange 4R, manufactured by Ciba Gaikie)
C,1, Pigment Yellow 17 ()7 St Yellow GBFN, manufactured by Sumitomo Chemical Co., Ltd.] C,1
, Pigment Yellow 93C Chromof Cool Yellow 3G, manufactured by Ciba Gaikie)
C, 1, Pigment Yellow 94 (Kurosef Cool Yellow 6G, manufactured by Senba Gaiki Co.)
c.1. Pigment Green 7 (Chromophthal Green GF, Ciba Geikie i1
C,1, Pigment Blue 15:3 (Carmine Blue GNR-0, manufactured by Sumikata Chemical Co., Ltd.) C,1
, Pigment Blue 60 (Chromophthal Blue A3R, manufactured by Ciba Geigy) The amount of these colored colorants used in the toner is preferably 3 to 20 parts by weight per 100 parts by weight of the binder resin constituting the toner. .

In addition to the above-mentioned vinyl resin and chromatic colorant, the toner of the present invention may contain various charge control agents, or fluidity of the toner.
Various additives such as hydrophobic silica and fatty acid metal salts can be added to improve cleaning performance, and 1lIIC type agents such as low-molecular polypropylene, polyethylene or wax can also be added to prevent toner offset. The addition of a negative agent such as polypropylene is preferably 1 to 10 parts per 100 parts of the binder resin constituting the toner.

To produce the color toner according to the present invention: - The vinyl polymer, the colored colorant, and various additives such as a release agent are thoroughly mixed in a ball mill or the like, and then thoroughly melted and wire-mixed in an extruder. It is sufficient to obtain toner of a predetermined particle size by cooling, pulverizing, and classifying. It is desirable that the obtained toner has a hiding power of 30% or more as measured below. Toners with the above-mentioned opacity of 30% or less are overprinted, and when they are affected by the undercoating, the image appearance tends to lack sharpness.

(Measurement of Concealability) 25 g of the toner to be tested is dissolved and dispersed in 150 mj of methyl ethyl ketone, applied onto a 100 μm thick polyester film using a wire bar to a dry film thickness of about 10 μm, and dried. The obtained sample was brought into close contact with white paper (lightness approximately 85) and black paper (lightness approximately 5) and CMS-1 was applied from the sample side.
The brightness of each color was measured using a 0008 model high-speed fractional colorimeter (manufactured by Murakami Color Research Co., Ltd.).

Concealability is indicated by the following 2.

YB: Brightness on black paper Yw: Brightness on white paper If the toner has a lower hiding power and the black paper placed on the back is seen through, the apparent brightness of the sample decreases and the above value decreases.

[Effects and actions of the invention]

As mentioned above, the color toner according to the present invention is composed of a binder resin that has a molecular weight distribution with a maximum in two regions, a high molecular weight region and a low molecular weight region, and therefore has a relatively low molecular weight that has a low fixing temperature. The toner has extremely desirable properties as a heat fixing toner, which has both the characteristics of a resin and the characteristics of a relatively high-molecular resin that has a high offset phenomenon occurrence temperature and is difficult to cause offset. In addition, since the above resins are synthesized as a single resin from the beginning, the load is 5 to 1 compared to simply mixing two types of resin. Defects such as the spread of the landscape and the occurrence of fog do not appear.

The present invention will be explained in detail below with reference to Examples.

〔Example〕

C) Synthesis of resin according to the present invention) In a separable flask with a volume of ff1lJ, partially saponified polyvinyl alcohol "Gohsenol GH-17J (manufactured by Nippon Gosei Kogyo Co., Ltd.) 0.1.9" was placed, and 100 mt of pure water was added to dissolve it. A mixture of 3ON styrene, 15F n-butyl acrylate, and 0.1 # of benzoyl peroxide was added to the solution, suspended and dispersed, and after the gas phase was replaced with nitrogen gas, polymerization was carried out by keeping the temperature at ℃. Post-dehydration and water washing were repeated, followed by drying to obtain a polymer.

The obtained polymer 4019 was converted into styrene 70I! - A solution was prepared by dissolving 30.9 g of benzoyl peroxide in a monomer mixture consisting of 30.9 g of acrylic acid. Take 200 m of pure water in a separable flask with a volume of filJ, add Gohsenol GH-17J 0.2I!, dissolve it, add the monomer solution of the polymer, suspend and disperse, and replace the gas phase with nitrogen gas. (Note) Polymerization was carried out again while maintaining the temperature at ℃.Then, the resin was cooled, washed with water, and dried to obtain a resin (①).

The molecular weight distribution of the obtained resin was determined using the gel ≠ vermiacetic chromatography analyzer, and it was found that the molecular weight distribution had maximums at molecular ffi of 13,000 and 220,000, respectively (compared to the synthesis of cat fat). ) As in the case of resin l, styrene 30I! A mixed solution of 15 g of butyl acrylate and 0.1.9 g of benzoyl peroxide was suspended in 1001 nt of pure water in which 119 of "Go-7Nol G) t-17J O,119 was dissolved, and the mixture was suspended in a nitrogen gas phase. Polymerization was carried out while maintaining the temperature at ℃.After cooling, the resin was dehydrated, washed with water, and dried to obtain resin (■).

According to the results measured by gel permeation chromatography, the molecular weight distribution of resin (1) had one maximum around 60,000. Resin ■ was also obtained by extending the polymerization time using the same formulation as cat fat ■. The molecular weight distribution of resin (1) had one maximum around 350,000.

(Preparation and testing of toner!) Take part of the above resin, add 5 parts by weight of red pigment PV Sofa Tread B (Hoechst Japan Co., Ltd.), and use polypropylene "Bisful 660PJ" as a release agent.
Sanyo Kasei Co., Ltd.) 2-jusha part was added and pre-mixed with a hexyl mixer, then Ex) A/- was melted vertically, kneaded, cooled, pulverized and classified to produce red toner ■ with an average particle size of approximately 12.5 μm. Obtained. Magnetic carrier DIP is applied to the obtained toner 21.
-135 (average particle size 100 μm, manufactured by Dowa Iron Powder Co., Ltd.) 1k
Prepare a developer by mixing and stirring g, and load it into an electronic copying machine rU-BIX 3000 J (manufactured by Konishiroku Photography Hata Rei), which has been modified so that the temperature of the heat roller of the fixing device can be freely changed/set. A photocopying test was conducted while changing the temperature of the heat roller, and the minimum temperature T of the heat roller at which the offset phenomenon began to occur and the minimum temperature T at which fixing was possible were determined.

Further, toners n and III were prepared using the resins (1) and (2) in the same manner as toner I, mixed with a carrier, and tested under the same conditions as for toner I to determine T1 and T.

In the fuser used in the above test, the surface layer of the heating roller was made of Teflon (manufactured by DuPont), and the surface layer of the opposing roller was made of silicone rubber KE-130OR, T, V-J (manufactured by Shin-Etsu Chemical Co., Ltd.). Met.

Furthermore, the hiding properties of the above three types of toners were all around 35%, and in this respect, they had practically sufficient properties. T1 and T2 of each toner obtained as a result of the test were as shown in Table 1.

Table 1 - A T1
721230°C or higher 160°G ■190°C 160°C ■230°C or higher 200°C Despite the low toner I/fixing temperature Tt of the present invention, the offset occurrence 111K'r is high, making it suitable for practical use.
On the other hand, toner ■, which is a comparison sample, has a low T, but also has a low T1, which tends to cause off-cent, and although toner ■ has a high offset F starting temperature, it is necessary for fixing. Try something with a high and satisfying temperature.
There wasn't.

Using the toner ■, the images obtained were clear with no fog, and no fog was observed due to the spread of the load distribution.OAs shown in the above examples, the color toner according to the present invention was It has been proven that it can be fixed at a relatively low temperature and has excellent heat fixing suitability with no offset phenomenon.

Agent Kuwa Hara 5 Mi

Claims (1)

[Claims] (1) In a color toner for developing electrostatic images mainly consisting of a binder resin and a chromatic colorant, the binder resin is
Gel permeation ≠ Molecular weight distribution measured by chromatography is molecular weight 108 to 5XIO' and io5
A color toner for developing electrostatic images, characterized in that it is a polymer or copolymer of vinyl thread monomers having at least one maximum in each of the two regions of 1 to 106.