JPS61126563A - Color toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To obtain a color toner having superior fixability at low temp. and a satisfactory nonoffsetting property and capable of forming a color image having high quality by using a specified vinyl polymer as a binder resin and adding specified pts. wt. of a releasing agent. CONSTITUTION:The vinyl polymer having a mol. wt. distribution in which it has at least one maximum in each of two region; the low mol. wt. region of 10<3>-5X10<4> mol. wt. and the high mol. wt. region of 10<5>-5X10<6> mol. wt. is used as a binder resin. A chromatic colorant and a releasing agent are dispersed in particles of the binder resin to obtain a color toner. Other additives are further added as required. The amount of the releasing agent used is 1-10 pts. wt. per 100 pts. wt. binder resin. In case of <1 part, a satisfactory nonffsetting property is not provided, and in case of >10 parts, the flowability of the toner is deteriorated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a color toner for quickly developing an electrostatic image formed by electrophotography, electrostatic printing, electrostatic recording, etc. It is.

[Technology background]

For example, in electrophotography, an electrostatic image is generally formed on a photoreceptor made of a photoconductive material by various means,
This electrostatic charge image is then developed with a toner containing charges of opposite polarity to the electrostatic charge image, and the resulting toner image is transferred to a transfer material such as paper and further fixed, thereby forming a visible image. In this way, the toner ′ used for developing electrostatic images
Since toner is subjected not only to the development of electrostatic images but also to the subsequent transfer and fixing processes, it is necessary to have not only developability but also good fixing properties.For fixing of toner images. The contact heat fixing method is widely used in which a heated member such as a heat roller is pressed onto the toner image and the binder resin constituting the toner is melted and fixed to the transfer material. Although it has various advantages, such as being able to achieve high-speed fixing, which is particularly required in recent years, it also has the problem that it tends to cause a so-called offset phenomenon due to the high temperature of the heat roller.

Therefore, stick around! In order to achieve good results, it is necessary to have a high minimum temperature at which the above-mentioned offset phenomenon occurs (hereinafter referred to as "offset occurrence temperature") and to have excellent non-offset properties, and also to have a low minimum fixing temperature and excellent low-temperature fixing. The toner is required to have the following characteristics.

However, in the case of color toners, chromatic colorants generally have larger particle sizes than the carbon black in black toners, and tend to have insufficient dispersibility in the binder resin. However, color toner has a lower elastic modulus when melted than black toner, which makes it more likely to cause an offset phenomenon.

In addition, in color toners, as mentioned above, the chromatic colorant dispersed in the binder resin generally has a larger particle size than the carbon black in black toner, so the smoothness of the surface of the toner particles is lower than that of the black color. Inferior to toner.

Therefore, the surface friction coefficient of a fixed color toner image is generally larger than that of a black toner image, so even if the color toner image and the black toner image are fixed to the transfer material with the same adhesive strength, A color toner image is more easily rubbed off than a black toner, and the storage stability of the toner image after fixing is inferior.

As described above, in the case of color toners, the actual situation is that there are more restrictions in selecting a binder resin than in terms of heat fixing properties.

[Purpose of the invention]

The present invention has been made against the above background, and its object is to provide an electrostatic charge image that has excellent low-temperature fixing properties and non-offset properties, and is capable of forming commercial quality color images and sounds. The purpose of the present invention is to provide color toner for development.

[Structure of the invention]

The present invention is characterized in that in a color toner for developing an electrostatic image formed by dispersing a chromatic colorant in a binder resin, the binder resin has a molecular weight distribution measured by gel permeation chromatography. is composed of a vinyl polymer having a molecular weight of 10 to 5×10 and 10 to 100, respectively, and has at least one maximum l in each of the two regions, and this vinyl contains 1−=IO parts by weight per 100 parts by weight of 1% polymer. The point is that it contains a mold release agent.

The present invention will be described in detail below. The color toner for developing electrostatic images of the present invention has two regions as a binder resin: a low molecular weight region with a molecular weight of 103 to 5XlO' and a high molecular weight region with a molecular weight of 105 to 108. At least one maximum in! It is constructed by using a vinyl polymer having a molecular weight distribution having a chromatic coloring agent, a mold release agent, and other additives added as necessary dispersed in particles of the binder resin.

The vinyl polymer is a polymer or copolymer of vinyl monomers, and its molecular weight is measured by gel permeation chromatography.

The above molecular weight is measured as follows: ・Water's 200 GPC (Water's 200 T
Solvent (tetrahydro 7 run) V/min at 25°C using a
While flowing down at a flow rate of -, a tetrahydro 7-run sample solution with a concentration of 0.2 g/dt is injected into the column in an amount of 4 dah as the sample weight, and the measurement is performed. The columns used here are a combination of 10'-10'-No'-10'.

The monodisperse polystyrene standard sample for setting the calibration curve is boristicine manufactured by Pressure Chemical Co., Ltd., and has a molecular weight of 1,800,000,860,000°411.
．． 000,160,000,98,200,51,00
0°19.800.10,00014,000 is used.

Vinyl polymer! The vinyl monomers to be given include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-methylstyrene, -tert-butylstyrene%P-"-hexylstyrene (p-n-octylstyrene s'9"-
Preferred examples include nostyrene monomers such as nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene%-p-phenylstyrene, P-chlorostyrene, and 3,4-dichlorostyrene. can be mentioned. In addition, for example, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and imbutylene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl fluoride; vinyl acetate, vinyl propionate, and benzoic acid. Vinyl esters such as vinyl and vinyl butyrate; methyl acrylate, ethyl acrylate, isobutyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, lauryl acrylate, acrylic 2-
Ethylhexyl, stearyl acrylate, acrylic acid 2
-Chlorethyl, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n- methacrylate
Butyl, isobutyl methacrylate, methacrylic acid n
-Octyl, dodecyl methacrylate, walyl methacrylate, 2-ethylhexyl methacrylate1. α-methylene aliphatic monocarboxylic acid esters such as stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide, etc. Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl imbutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; -ON-vinyl compounds such as vinylpyrrolidone;
Examples include vinylnaphthalenes and others.

27) Among those obtained using the above monomers, styrene-acrylic copolymers are particularly preferred.When using the above monomers, the molecular weight distribution used in the present invention has two or more maxima! Polymers or copolymers with 1. One or more of the above monomers selected according to the type of polymer to be obtained and a polymerization initiator such as benzoyl peroxide are mixed and polymerized under certain reaction conditions, and the resulting polymer is The mold release agent can be obtained by mixing with a new monomer and a polymerization initiator, and then carrying out a polymerization reaction. Examples of the mold release agent include polyolefins, fatty acid metal salts,
Fatty acid ester, partially saponified fatty acid ester, higher fatty acid, higher alcohol, liquid or solid paraffin wax, amide wax, long alcohol ester, silicone varnish, aliphatic prolocarbon, etc.
can.

Such mold release agents can be used singly or in combination of two or more.

The polyolefin includes 1, for example polypropylene,
Resins such as polyethylene and polybutene, JIB,'
The softening point is 80 to 180 DEG C., preferably Fi 100 to 1601:O, as measured by the ring and ball method specified in . Examples of the fatty acid metal salts include stearic acid and zinc, cadmium,
Metal salts with barium, lead, iron, nickel, cobalt, copper, aluminum, magnesium, etc.; dibasic lead stearate; metal salts with oleic acid and zinc, magnesium, iron, cobalt, steel, lead, calcium, etc.; Metal salts of balmitic acid and aluminum, calcium, etc.; lead caprylate;
Examples include capron 112 lead; metal salts of linole and zinc, cobalt, etc.; ricinol and calcium salts; metal salts of lysyllic acid and zinc, cadmium, etc., and mixtures thereof. Examples of the fatty acid ester include maleic acid ethyl ester, maleic butyl ester, stearic acid methyl ester, stearic acid butyl ester,
Examples of the partially saponified fatty acid ester include cetyl palmitate, ethylene glycol montanate, and the like.An example of the partially saponified fatty acid ester is a partially saponified calcium ester of montanate. Examples of the higher fatty acids include dodecanoic acid, lauric acid, myric acid,
Valmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid, arachidic acid, behenic acid, lignoceric acid, ceracoleic acid, etc. and mixtures thereof may be mentioned. Examples of the higher alcohol include dodecyl alcohol, dicryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol,
Arachyl alcohol, behenyl alcohol, etc. can be mentioned. Examples of the paraffin wax include natural paraffin, microwax, synthetic wax,
Examples include chlorinated hydrocarbons.

Examples of the amide waxes include fatty acid amides such as stearic acid amide, oleic acid amide, palmitic acid amide, lauric acid amide, behenine amide, methylene bis stearamide, and ethylene bis stearamide. Examples of the alcohol ester include glycerin stearate, glycerin lysyllate, chrycerin monobehenate, sorbitan monostearate, propylene glycol monostearate,
Examples include sorbitan triolate. Examples of the silicon face include methyl silicon face, % phenyl silicon face, and the like. The aliphatic fluorocarbon is, for example, a low polymer compound of tetrafluoroethylene, hexafluoropropylene, or JP-A-53-12442.
Examples include fluorine-containing surfactants described in Publication No. 8.

The amount of these mold release agents used is 100% of the binder resin.
The amount is 1 to 10 parts by weight. If the amount of the release agent used is less than 1 part by weight, sufficient anti-offset properties cannot be obtained, while if it exceeds 10 parts by weight, the fluidity of the toner becomes insufficient, both of which are undesirable.

The chromatic coloring agent includes various organic pigments and inorganic pigments, and various dyes, but organic pigments with clear colors, high light resistance, and high hiding properties are preferable, such as the following. (Mongke is a color index
3rd edition 1971 Supplement 1975, C, I, name code, and 1ζ shown in one example of the corresponding product name O) C, Engineering, Pigment Red 5 (Permanent Carmine FB, Hoechstja/Kunsha (manufactured by) C, Iφ Pigment Red 48:1 (Sumika Print Red C1 manufactured by Sumitomo Chemical ■) C・■・Pigment Red 53:1 (Chromophthal Magenta G, manufactured by Ciba Geigy) C
Banko Pigment Red 57:l (Sumika Print Carmine 6BC, manufactured by Sumitomo Chemical Co., Ltd.) C,
1, Pigment Red 123 (Kayaset Red E-B, manufactured by Nippon Kayaku ■) C, I. Pigment Red 139 (Kayaset Red E-GR, manufactured by Nippon Kayaku ■) C・1@
Pigment Red 144 (Chromophthal Red BRN, manufactured by Ciba Geigy)
C, 1 @ Pigment Red 149 (PV Fast Red B1 manufactured by Hoechst Japan Co., Ltd. ΣC, Top Pigment Red 166 (Chromophthal Scarlet R1 manufactured by Chipai Geigy Co.) C, 1, Pigment Red 177 (Chromophthal Red A3B , manufactured by Ciba Geigy)
C, I @ Pigment Red 178 (Kaya Set Red E-GG, manufactured by Nippon Kayaku ■) C, I・
Pigment Red 222 (Chromophthal Red Magenta G, manufactured by Civer Geigy) C・■・Pigment Orange 31 (Chromophthal Orange 4R, manufactured by Civer Φ Geigy)
CΦ■e Pigment Orange 43 (Hosta Palm Orange GR, manufactured by Hoechst) C・Engineer・
Pigment Yellow 17 (Fast Yellow GBFN, manufactured by Sumitomo Chemical) C, I Pigment Yellow 14 (Benzidine Yellow OT, manufactured by DuPont) C, I Pigment Yellow 138 (Variotol Yellow LO960HD, manufactured by Bass 7)
C・■・Pigment Yellow 93 (Croceftal Yellow 3G, Chipa Geigy M>
C, I-Pigment Yellow 94 (Croceftal Yellow 6G, manufactured by Ciba Geigy)
C・■・Pigment Green 7 (Chromophthal Green GF, manufactured by Chipa Geigy)
C, 1, Pigment Blue 15:, 3 (Carmine Blue GNR-0, manufactured by Sumitomo Chemical Co., Ltd.) C・■・Pigment Blue 60° (Chromophthal Blue A3R, manufactured by Chipa Geigy Co., Ltd.)
In addition to the above organic pigments, red iron oxide, titanium oxide, carbon black, etc. can also be used.

These chromatic colorants can be used alone or in combination of two or more. The chromatic colorant is preferably used in an amount of 3 to 20% by weight based on the binder resin.

In addition to the above-mentioned vinyl polymer, chromatic layer colorant, and release agent, the present invention also includes a fluidity improver for improving the fluidity of the toner, and a fluidity improver for controlling the triboelectric charging characteristics of the toner. Additives such as charge control agents can be used to

In order to produce the color toner of the present invention, for example, the vinyl polymer, the chromatic colorant, the release agent, and other various additives are thoroughly mixed in a ball mill or the like, and then sufficiently melted in an extruder to form a line. It is sufficient to mix, cool, pulverize, and classify to obtain a toner of a predetermined particle size. The color toner of the present invention preferably has a spectral reflectance of 40 hiss or less at a wavelength of 530 to 580 nm.
In this case, it is possible to control various color toners using one sensor, and furthermore, it is possible to effectively prevent malfunctions when detecting jams in continuous printing paper, etc.

〔Effect of the invention〕

The color toner of the present invention is composed of a paint resin that has a molecular weight distribution with a maximum in two regions, a high molecular weight region and a low molecular weight region, so it has the characteristic of a relatively low molecular weight resin that the fixing temperature is low. The toner has extremely desirable properties as a heat fixing toner, which also has the characteristics of a relatively high molecular weight resin, such as having a high offset generation temperature and being difficult to cause offset. In addition, since the above resins are synthesized as an integrally mixed resin from the beginning,
The disadvantage that the toner's triboelectric charge distribution spreads and capri occurs, which occurs when two types of resins are simply mixed, is less likely to occur.

Furthermore, the color toner of the present invention has a -type agent of 4+! Since it is contained in a constant proportion, the releasability of the toner is improved and excellent non-offset properties are exhibited. In addition, according to this color toner, the surface of the fixed toner becomes smooth due to the action of the release agent, so that the toner is not damaged by external mechanical forces such as scraping. It is possible to form stable images that do not lose their sharpness over a long period of time.

As described above, since the color toner of the present invention uses a specific binder resin and a release agent, the synergistic action of the two exhibits excellent heat fixing properties and forms high-quality color images. be able to.

[Embodiments of the invention]

Examples of the present invention will be described below, but the present invention is not limited thereto. Note that "part" indicates part by weight.

(Synthesis of binder resin) (1) Resin A In a separable flask with a capacity of 1 ton, put 0.1 g of partially saponified polyvinyl alcohol "Gohsenol GH-17" (manufactured by Nippon Gosei Kogyo Co., Ltd.), add 100% pure water, and dissolve. ,
In it, 30g of styrene, 1 acrylic #1. n-butyl 1
A mixture of 5 g and 0.1 g of benzoyl peroxide was added and dispersed, and after replacing the gas phase with nitrogen gas, the temperature was raised to 80°C.
Polymerization was carried out while maintaining the temperature at ℃. After cooling, dehydration and water washing were repeated, followed by drying to obtain a polymer. Obtained polymer 40
Dissolve g in a monomer mixture consisting of 70 g of styrene and 30 g of acrylic acid, and add 5 g of benzoyl peroxide:
In addition, a solution was prepared. Add 2005 g of pure water to a Sepa 2-pull flask with a capacity of Xt and add 9.
- 2g9 was added and dissolved, and a 7-mer solution containing the above polymer was added for suspension and dispersion, and after replacing the vapor phase with nitrogen gas, the temperature was maintained at 80°C and polymerization was carried out again.

Thereafter, it was cooled, washed with water, and dried to obtain a resin.

This will be referred to as "resin A."

The molecular weight distribution of the obtained resin A was determined using the above-mentioned gel permeation chromatography analyzer, and it was found that the molecular weight distribution had maximum values at 13,000 and 220,000, respectively.

(2) Comparative resin B A mixed solution of 30 g of styrene, 15 g of butyl acrylate, and 0-1 g of benzoyl peroxide was mixed with [Go7)-A/GH-
17JO-1g was dissolved or suspended in 100m of Ll pure water, and polymerization was carried out by keeping it screwed in a nitrogen gas phase. After cooling, it was dehydrated, washed with water, and dried to obtain a resin. This is referred to as "comparative resin B."

According to the results measured by gel permeation chromatography, the molecular weight distribution of comparative resin B was tit 60,
It had one maximum near 000〇(3)
Comparative Resin C A resin was obtained by extending the polymerization time in the direction of Comparative Resin B and X-i. This is referred to as "comparative resin C." The molecular weight distribution of comparative resin C has one maximum near 350,000, and is 690 (preparation of color toner).Example 1 Resin A I00 parts C
, I. Pigment Red 149 2
-25 parts "PV Fast Red BJ (manufactured by Hoechst Japan) C-I Pigment Red 5
Part 5.25 “Hermanent Carmine FBJ (
(Manufactured by Hoechst Java) Low molecular weight polypropylene
Part 2 “Viscoal 660PJ
(Manufactured by Sanyo Chemical Co., Ltd.) Charge control agent
2 parts [substances larger than Bontron E-81J (manufactured by Orient Chemical Co., Ltd.)] were premixed in a Henschel mixer, melted and kneaded in an extruder, cooled, pulverized, and classified to have an average particle size of approximately 12.5 μm. I got a red color toner.

This is referred to as "toner 1".

Example 2 Phthalocyanine blue (C, I/Pigment Flu 15:3) 7.5 instead of the chromatic colorant in Example 1
A blue color toner was obtained in the same manner as in Example 1, except that 9.0% was used. This will be referred to as "toner 2".

Comparative Example 1 A red color toner was obtained in the same manner as in Example 1 except that Comparative Resin B was used instead of Resin AC in Example 1. This will be referred to as "comparison toner l".

Comparative Example 2 Example 2 except that comparative resin Ct was used instead of resin A in Example 2. A blue color toner was obtained in the same manner as above and is referred to as "Comparative Toner 2".

Comparative Example 3 A red color toner was obtained in the same manner as in Example 1 except that the low molecular weight polypropylene in Example 2 was not used. this! "Comparative Toner 3" (actual photo test) Toner 1 and Toner 2 and 20 g of each of Comparative Toner 1 to Comparative Toner 3 were added styrene-methyl methacrylate copolymer (composition ratio 30 near 0) Y Coated magnetic carrier 1"DSP-135J (average particle size 100/' fil% manufactured by Dowa Iron Powder Co., Ltd.) lKqY Mix and stir to prepare the developer, especially the temperature of the heat roller of the fuser! You can freely change and set it. Modified to nine electronic copying machines
U-BiX 25004 (manufactured by Konishiroku Photo Industry Co., Ltd.)
The temperature of the heat roller was electrified and an actual photographic test was conducted to determine the minimum fixing temperature and the offset occurrence temperature l.

Regarding the minimum fixing temperature, a fixing device consisting of a heat roller whose surface layer is made of Teflon (polytetrafluoroethylene manufactured by DuPont) and a pressure roller whose surface layer is made of silicone rubber KE-1300RTVJ (manufactured by Shin-Etsu Chemical Co., Ltd.) is used. The operation of fixing the toner image of the sample toner transferred onto a 64 g/m'' transfer paper in a layer at a linear velocity of 120 mm was carried out by increasing the set temperature of the heat roller step by step by 5 degrees Celsius from 140 degrees Celsius. Repeatedly apply paper with a rough surface, such as rJ, to the formed fixed image.
Kimwipe rubbing was performed using K Wiper 150-5J (manufactured by Jujo Kimberly Co., Ltd.), and the lowest setting temperature for a fixed image that showed sufficient scratch resistance with a small degree of paper staining was used as the minimum fixing temperature. 2 The fixing device used here does not have a silicone oil supply mechanism.

Regarding the offset occurrence temperature, in accordance with the measurement of the minimum fixing temperature, the toner image is transferred and fixed by the above-mentioned fixing device, and then a blank transfer paper is sent to the fixing device under the same conditions and the image is fixed. The operation of observing whether or not toner stains occur is repeated with the set temperature of the heat roller of the fixing unit being sequentially increased, and the lowest set temperature at which toner stains occur is defined as the offset occurrence temperature of 0 or more. The results are shown in Table 1. As is clear from the results in Table 1, all of the color toners of the present invention have the lowest fixation i! It has a low density and a high offset generation temperature, so it has a wide fixable temperature range and excellent uniform layering properties. On the other hand, in Comparative Example 1, the binder resin has a molecular weight distribution of 2, with only one maximum in the low molecular weight region, so offset generation and hiding are low, and in Comparative Example 2, the binder resin Since the molecular weight distribution has only one maximum in the region of 2 and polymer 1, the i# and low fixing temperatures are high, and the fixable temperature range is narrow in both cases, making it impractical. In Comparative Example 3 and 2, since the toner does not contain a release agent, the surface smoothness of the fixed image is poor, and as a result, the fixed image is peeled off and becomes rough due to Kimwipe rubbing, and the lowest fixing temperature is applied. Example 1 High compared to tc, and low offset occurrence temperature.

Agent: Masahiko Oi, Patent Attorney L':, ' ”
'difference·

Claims (1)

[Scope of Claims] 1) A color toner for developing an electrostatic image formed by dispersing a chromatic colorant in a binder resin, wherein the binder resin has a molecular weight distribution measured by gel permeation chromatography. has a molecular weight of 10
Consisting of a vinyl polymer having at least one maximum in each of the two regions ^3 to 5 x 10^4 and 10^5 to 10^6, and this vinyl polymer 100
A color toner for developing electrostatic images, characterized in that it contains 1 to 10 parts by weight of a release agent.