JPS61126564A - Color developer for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To form stably a high density color image having high quality with no fog by blending a carrier having a coating layer contg. vinylidene fluorovinylidiene-tetrafluoroethylene copolymer with a color toner contg. a specified polyester resin as a binder resin. CONSTITUTION:A polyester resin contg. 5-25wt% chloroform-insoluble matter is used as a binder resin, and a chromatic colorant is dispersed in particles of the binder resin to obtain a color toner. Additives such as a releasing agent are further added as necessary. A color developer is composed of the color toner and a carrier obtd. by forming a coating layer contg. the fluorovinylidene- tetrafluoroethylene copolymer whose triboelectric charge polarity is negative to the polyester resin in the color toner on the surface of the core material. The color toner functions as a positively chargeable toner. The polyester resin is obtd. by bringing polyol and polycarboxylic acid into a condensation polymn.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is directed to a bibasic force 2 for developing electrostatic images formed in electrophotography, seiden printing, electrostatic recording, etc. -Developing agent, color developer (=concerning a color developer in which the toner is positively charged by contact with a carrier.

[Technology background]

M,tl-! In electrophotography, an electrostatic image is generally formed on a photoreceptor made of a photoconductive material by various means, and then this electrostatic image is transferred to a toner having a charge of the opposite polarity to that of the electrostatic image. Then, the resulting toner image is transferred to a transfer material such as paper, and then a new image is formed by pressing the toner image onto a transfer material such as paper.

As described above, the toner used for developing electrostatic images is required to have the following characteristics, since it is used not only for developing electrostatic images, but also for the subsequent transfer and fixing processes. Ru.

(1) Good triboelectric charging characteristics should be maintained at 1°.

That is, in order to achieve good development of an electrostatic image,
It is necessary for the toner to maintain a charge M having the proper polarity and band Xt in the proper range of 1 by 111 rubbing contact with the carrier.

(2) Possess good heat fixing properties.

For fixing toner images, a contact heating fixing method is widely used, in which heated members such as a heating roller 2 are alternately layered on the toner 41, and the binder resin constituting the toner is melted and fixed to the transfer material. This contact heating fixing method has high stain heat efficiency, and can delay the high-speed fixing that has become particularly important in recent years.As the anti--1 heat roller, which has various dog points, becomes high temperature, a so-called offset phenomenon occurs. Therefore, in order to perform good fusing, the minimum temperature at which the above-mentioned offset phenomenon occurs (hereinafter referred to as "offset occurrence temperature") must be set to a high <'1: dredged. Toners are required to have excellent low-temperature fixing properties with a low minimum fixing temperature, as well as excellent non-offset properties.

By the way, carbon black, which is used as a colorant in black toner, has an IT control effect, and a control agent with a unique color can also be used without restrictions, so it is possible to control the triboelectric properties of toner. It can be said that it is relatively easy.

However, for color toners that require vivid coloring, it is undesirable to use a Mu control agent that has a unique color that impairs the toner tone, and it is preferable to use it as a chromatic colorant. Since pigments or dyes themselves rarely have charge control properties, there are many restrictions on the selection of fIK control agents, and it is not always easy to control the triboelectric properties of toners. , the chromatic layer colorant is -ff compared to carbon black in black toner.
Since the K particle size is large, the dispersibility in the binder resin tends to be insufficient, and as a result of the above, it is hardly possible to increase the elastic modulus of the toner by filling the colorant. Therefore, color toners have a lower modulus of elasticity when melted in a bath than black toners, causing problems such as an offset phenomenon.

As described above, when it comes to color toners, the actual situation is that the selection of binder resin is accompanied by more restrictions than the thermal constant N characteristics. The seventh objective was to develop a color toner that could obtain a good charging state through frictional contact with the carrier and also had excellent heat fixing properties. An object of the present invention is to provide a color developer for developing a silent image, which contains a high image density and is capable of stably obtaining a high-quality color image without capri. This is because in a statically charged 3A color developer comprising a carrier and a color toner formed by dispersing a chromatic colorant in a binder resin, the carrier is vinylidene fluoride-tetrafluoride. The color toner has a coating layer containing an ethylene copolymer, and the binder side B of the color toner has a chloroform insoluble content of 5 to 25% by weight.
The point is that it contains polyester resin.

Hereinafter, the non-invention will be explained in detail.

The color developer of the present invention contains 5 to 5 as binder resin.
Formed by using polyester mB& containing 25% by weight of chloroform-insoluble matter t-V, and dispersing additives such as a chromatic coloring agent and a mold release agent added as necessary in the particles of the rot fat. The surface of the core material is coated with a laminated layer containing a polyvinylidene hepta-tetrafluoride copolymer having a negative polarity that creates a friction zone against the toner and the polyester resin constituting the color toner. The color toner can be used as a positively chargeable toner. First, the color toner containing the developer of the present invention will be explained.

Polyester resin used as binder resin for toner
Fats are obtained by polycondensation of polyhydric alcohols and polycarboxylic acids. Examples of such polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, 1.2-propylene glycol, and 1.3-propylene glycol. , 1,4-butanediol, neopentyl glycol, 1,4-butynediol and other diols, 1
．． 4-bis(hydroxymethyl)cyclohexane, etherified bisphenols such as 4-bisphenol A1 and bisphenol A% polyoxyethylated bisphenol A, polyoxypropylenated bisphenol A, and other monomer dihydric alcohols. Examples of polyvalent carboxylic acids include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, inphthalic acid, terephthalic acid, cyclohequinanedicarboxylic acid, succinic acid, and adipine. Examples include heptapathic acid, malonic acid, anhydrides of these acids, dimers of lower alkyl esters and lyluic acid, and other divalent organic acid monomers.

The polyester Kiritsuki used in the binder Kiritsuki includes not only the above-mentioned polymers made only of difunctional monomers, but also
It is also suitable to use a polymer containing a component of a trifunctional or higher polyfunctional monomer. Examples of such a polyfunctional monomer, such as a trivalent or higher polyhydric alcohol monomer, include sorbitol. , It2.3.6-hexanetetrol,
l,4-sorbitan, pentaerythritol, cyhentaerythritol, tripentaerythritol s M!
s s l-2,4-butanetriol, 1,2.5-
Pentanetriol, glycerol, 2-methylgulonosintriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane%1 #3=5”-)rihydroxymethylbenzene, and others to mention. For example, t'!: 1, 2.4
-Benzenetricarboxylic aS l-2,5-benzenetricarboxylic acid, 1.2.4-cyclohexenetricarboxylic acid, 2,5.7-naphthalenetricarboxylic acid, 1.2
．． 4-su7talenttricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hequinanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxylpropane, tetra(methylene (carboxyl)methane, 1,2.7t8-octanetetracarboxylic acid, diimbol tributic acid, their aqueous anhydrides, and others.

It is desirable that the above trifunctional or higher polyfunctional monomer component be contained in a proportion of 30 to 80 moles in each of the alcohol component or acid component as a structural unit in the polymer.

The polyester resin used in the present invention has a chloroform-insoluble content of 5 to 25 parts by weight.If a polyester resin having a chloroform-insoluble part of less than 5 parts by weight is used,
The resulting toner will have a low offset generation temperature, and on the other hand, if a polyester resin with a chloroform-insoluble content of more than 25% by weight is used, the minimum fixation fL equation will become high, and in either case, there is a wide fixable temperature range. Therefore, good fixation cannot be achieved.

The chloroform-insoluble content herein refers to the content that does not pass through F paper when a sample is dissolved in chloroform, and is determined as follows.

5. Sample powder obtained by finely pulverizing a 61 fat sample and passing it through a 40 mesh sieve. OOg was collected and placed in a container with a capacity of 150 with 5.00 g of super-aiding agent Radiolite (Su700), 100 g of chloroform was poured into this container, and the mixture was placed on a ball mill stand and rotated for more than 5 hours. Thoroughly dissolve the sample in chloroform. - Place F paper (m2) with a diameter of 7 cm in the pressurized container,
On top of that, 5. After uniformly pre-coating OOg of Radiolite and adding a small amount of chloroform to keep the F paper in close contact with the filter, the contents of the container are poured into the filter. Furthermore, the container is thoroughly washed with 100% chloroform and passed through a filter to prevent any residue from remaining on the wall of the container. After that, close the top lid of the filter and perform filtration.Filtration is performed under a circumferential pressure of 4K4/am" or less, and after the outflow of chloroform has stopped, add 1 new chloroform
00- is added to wash the residue on paper 7, and pressure filtration is performed again.

After the above operations have been completed, place the F paper, the residue on it, and the radio light on aluminum foil and place it in a vacuum dryer at a temperature of 80 to 100℃ and a pressure of 100mm.
After drying under Hg conditions for 10 hours, the total weight a (g) of the dried product thus obtained was measured, and the chloroform insoluble content X (% by weight) was determined by the following formula.

X (wt%) In the case of polyester resin, the chloroform-insoluble content determined in this manner is a high molecular weight polymer component or a crosslinked polymer component, and the molecular weight of %7 is S approximately 2.
00,000 or more.

The above-mentioned chloroform-insoluble components can be controlled to a considerable extent by appropriately selecting reaction conditions or by allowing an appropriate crosslinking agent to exist in the reaction system in the polymerization reaction between alcohol and carboxylic acid. Can be formed in proportions.

The polyester resin used in the present invention is
Those having a softening point of 110 to 160°C, more preferably 120 to 140°C, are preferred when measured by the cursor method specified in JIS Go 4 Punch I2531-1960.

The chromatic coloring agent constituting the toner includes various organic pigments, inorganic pigments, and various dyes, but organic pigments with bright colors, high light resistance, and hiding properties are preferable, and examples include the following. There are things that can be mentioned. (Pigments are Power 2 - Index 3rd edition 1971 Supplement 197)
C@1 described in 5. Please indicate the name number and the corresponding product name. ) C, I Pigment Red 5 (Permanent Carmine FB, Hoechst Japan U) C
, 1, Pigment Red 48:l (Sumika Print Red C1 manufactured by Sumitomo Chemical ■) C・■・Pigment Red 53:l (Chromophthal Magenta G, manufactured by Ciba Geigy) C
, I. Pigment Red 57:'1 (Sumika Print Carmine 6BC, Sumitomo Chemical Co., Ltd.) C, I.
Pigment Red 139 (Kayaset Red E-GR, manufactured by Nippon Kayaku) C.16
Pigment Red 144 (Chromophthal Red BRN, manufactured by Chipa Geigy)
C, I Pigment Red 149 (PV Fast Red B, Hoechst Japan! A
) C. Top Pigment Red 166 (Chromophthal Scarlet R, manufactured by Ciba Geigy) C, Z. Pigment Red 177 (Chromophthal Red A3B, manufactured by Ciba Geigy)
C, I Pigment Red 178 (Kayaset Red E-GG, Nichifu Kayakujin) C, I Pigment Red 222 (Chromophthal Red Magenta G, manufactured by Chipper Geigy) C, 1, Pigment Orange 31 (Chromophthal Red Magenta G, manufactured by Chipper Geigy) Mokhtar Orenshi 4R, Chiha Tsubo Kaikeysha''n
) C, I-Pigment Orange 43 (Manufactured by Hostapalm Orange GR, Hex) Co., Ltd.) C,1,
Pigment Yellow 17 (Fast Yellow GBFN, manufactured by Sumitomo Chemical Co., Ltd.) C Life IΦ
Pigment Yellow 14 (Benzidine Ye!-OT, manufactured by DuPont) C, I・
Pigment Yellow 138 (Variotol Yellow LO960HD, manufactured by Bass 7)
C・■・Pigment Yellow 93 (Croceftal Yellow 3G, manufactured by Chipa Geigy)
C, I-Pigment Yellow 94 (Cromontal Yellow 6G, manufactured by Chipaken Geigy)
C-■ Pigment Green 7 (Chromophthal Green GF, manufactured by Chipa Geigy)
C.1 @ Pigment Blue 15:3 (Carmine Blue GNR-0, manufactured by Shōtomo Chemical Co., Ltd.) C. Topigment Blue 60 (Chlosophthal Blue A3R, manufactured by Chipa Geigy Co., Ltd.)
In addition to the above organic pigments, pigments, titanium oxide, carbon black, etc. can also be used.

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

As the additives added to the toner as necessary, those used in the appropriate toner may be used. For example, various release agents may be used to improve the non-offset properties of the toner. This is desirable.

Examples of such mold release agents include polyolefin fatty acid metal salts, fatty acid esters, partially cured fatty acid esters, higher fatty acids, higher alcohols, liquid or solid paraffin waxes, amide waxes, polyolefin fatty acid metal salts, fatty acid esters, aliphatic Examples include fluorocarbon and the like.

Any part or mixture of two or more of the above mold release agents may be used.C1
1iW can be used. Examples of the polyolefin include polypropylene,
JI for November of polyethylene, polybutene, etc.
S7. , i, 2531-1960, has a softening point of 80 to 180°C, preferably 1
00 to 160°C. The fatty acid metal salts include, for example, metal salts of stearic acid and zinc, cadmium, barium, lead, iron, nickel, cobalt, acupuncture aluminum, magnesium, etc.; dibasic lead stearate; iron, cobalt, copper, lead,
Metal salts with calcium, etc.; metal salts of palmitic acid with aluminum, calcium, etc.; lead caprylate; caproic acid salts; metal salts of linoleic acid with zinc, cobalt, etc.; Examples include metal salts with and mixtures thereof. Examples of the fatty acid ester include maleic ethyl ester, butyl maleate, methyl stearate, butyl stearate, cetyl lumitate, ethylene glycol montanate, and the like. Examples of fatty acid esters include partially saponified calcium products of montanic acid esters. Examples of the higher fatty acids include dodecanoic acid, dicarboxylic acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, and ricinol. Examples of the higher alcohols include dodecyl alcohol, lacrylic alcohol, myristyl alcohol, cumyl alcohol, stearyl alcohol, aracyl
Examples include alcohol, behenyl alcohol, and the like. As the paraffin wax, for example, natural/
<Rough-in, microwax, synthetic paraffin, chlorinated hydrocarbons, etc.

Examples of the amide waxes include stearic acid amide, oleic acid amide, oleic acid amide, lauric acid amide, behenic acid amide, methylene bis stearamide, ethylene bis stearamide, etc. The polyhydric alcohol Examples of the ester include glycerin stearate, glycerin lysyllate, glycerin monobehenate, sorbitan monostearate, propylene glycol monostearate, sorbitan triolate, etc. Examples of the silicone resin include methyl silicone resin, phenyl Examples of the aliphatic fluorocarbons include low polymer compounds of tetrafluoroethylene and hexafluoropropylene, and the fluorine-containing surfactants described in ! The amount of these mold release agents used is 100% of the binder resin.
1-10 parts by weight. If the amount of the 1Iil type agent used is less than 1 part by weight, sufficient non-offset properties cannot be obtained; If it exceeds 100 parts, the fluidity of the toner will be insufficient, which is undesirable.

The toner used in the present invention has characteristics such as toner mobility, non-filming property, that is, a property that does not cause filming caused by a part of the toner adhering to the surface of the carrier or an electrostatic image, pulverizability, and charging property. For the purpose of improving properties such as properties, a resin may be contained. Preferably used resins are 1, for example, uncrosslinked polymers that do not contain chloroform-insoluble matter, such as styrene, parachloride, etc. Styrenes such as styrene, vinylnaphthalene, vinyl esters such as vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl penzoate, vinyl butyrate, methyl acrylate, acrylic Ethyl acid, acrylic fRn
- Methylene aliphatic compounds such as butyl, acrylated isobutyl, dodecyl acrylate, n-octyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate. Carboxylic acid esters, acrylonitrile, methacrylonitrile, acrylamide, vinyl ethers such as vinyl methyl ether, vinyl imbutyl ether, vinyl methyl ether, vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone, such as N-vinyl pyrrole,
N-vinylcarbazole, N-vinylindole, N-
N-vinyl compounds such as vinylpyrrolidone, homopolymers obtained by polymerizing other monomers, copolymers obtained by copolymerizing two or more of these monomers, or mixtures thereof; For example, non-vinyl resins such as rosin-modified phenol-formalin resin, oil-modified epoxy resin, polycretan resin, cellulose resin A & non-vinyl thermoplastic resin such as polyether resin, or the above-mentioned vinyl resins. These resins can be contained in a content ratio of 301 L or less of the binder resin as long as the effects of the invention are not impaired.

In order to co-manufacture the toner used in the present invention, the above-mentioned polyester resin, chromatic colorant, and various additives used if necessary are premixed using a mill or the like, and each component is mixed together. The mixture is uniformly mixed and dispersed, then kneaded using a hot roll, cooled, pulverized, and classified to obtain a toner having a desired average particle size. Although the particle size of the toner varies depending on the conditions of use, it is generally desirable to set it at a range of about 5 to 20 pm.

Next, the carrier constituting the developer of the present invention will be explained.

The copolymerization molar ratio of vinylidene fluoride-tetrafluoroethylene copolymer contained in the -ia layer of the carrier is 75:25 ~
In the range of 95:5, preferably from 75:25 to 87.5:
It is in the range of 12.5. If the above range is exceeded, as is clear from the comparative examples described below, there are disadvantages such as poor solvent solubility, poor film forming properties of the coating resin, and low film strength.In other words, the molar composition ratio of the copolymer is limited. Positive effects such as improved solvent solubility, improved film formability and film strength, and ultimately improved durability can only be achieved within the range of the formula.

In addition, if the molecular weight increases even if the solvent solubility improves, the viscosity of the solution will increase and the thickness of the laminated film will become uneven, causing pinholes and durability problems, so this is not preferable. However, if the molecular weight is even lower, problems will arise in the durability of the coating layer due to a decrease in resin strength.
℃) is in the range of 0.1 dt/g to 5 dt/g. Therefore, the above-mentioned laminated layer consists of a vinylidene fluoride-tetra7-ethylene ethylene copolymer and a second copolymer that is compatible with the copolymer. Consists of polymer blends with polymers. The second polymer is preferably one that can contribute to improving the adhesion between the core material and the coating attrium; for example, a methyl methacrylate copolymer is preferred.

A polymer blend of the copolymer and straw 2 polymer contains 50 to 90% by weight of the copolymer and 50% by weight of the second polymer.
It is desirable to contain up to 10% by weight.

Is there a risk of resin compatibility if it exceeds the above range? ! In the production of carriers used in the invention, vinylidene fluoride-tetra7-ethylene copolymer (copolymerized mol. Ratio 7
5:25-95:5, preferably 75:25-87.5
: 12.5) and the second polymer are dissolved in an organic solvent to prepare a coating liquid, and after spraying on the surface of the carrier core material to form a coating layer, for example by dry spraying, this is further heated. Or, by leaving it alone, you get a carrier that can be used for non-inventive purposes.

Specifically, for example, in a transfer ped device, the carrier core material is raised to an equilibrium height of 1 by a rising pressurized gas flow, and then the coating liquid is sprayed by the time the core material falls again. Apply. This is possible because it has a high property.◎If there is agglomerated carrier, it can be sieved to finally obtain the carrier of the present invention having the desired film thickness.

The organic solvent used in the production of the carrier may be any solvent as long as it dissolves the resin containing the vinylidene fluoride-tetrafluoroethylene copolymer of the present invention as a main component, such as acetone, methyl ether ketone, etc. Ketones such as Nato dihydrofuran, dioxane, dimethyl sulfoxide, or a combination of these solvents are used.

To this invention? Materials that are conventionally used as carrier core materials, such as sand, glass, and metal, can be used as the core material of the carrier, but in particular, materials that are strongly magnetized in that direction by the LA field, such as ferrite, can be used. , Magnetite, iron, cobalt, nickel, and other metals that exhibit ferromagnetism, or alloys or compounds containing these metals; Suitable examples include alloys of the type called Heusler alloys such as manganese-steel-aluminum or manganese-copper-tin, and chromium dioxide. The particle size of these carrier core materials is 30 to 1000 μm, preferably 50 to 500 μm.The thickness of the coating layer of the carrier in the present invention is O.OS to 20 μm%, especially 0.000 μm.
1 to 2 μm is preferable.

The uninvented carrier has 5 to 50 microtons/g of toner with which it is used under normal operating conditions.
It is preferable that it gives a positive charge of .

〔Effect of the invention〕

According to the present invention, as is clear from the xm example described below, by using a suitable combination of toner and carrier, a high quality color image with high image density and no fog can be formed without causing offset @. By doing so, it is possible to provide a color developer that does not cause filming on the photoreceptor or the like.

That is, the color toner used in the present invention is:
Since the binder resin is made of polyester resin containing a certain range of high molecular weight components that are insoluble in chloroform, it has a low softening point and a high off-cera) N generation device, and the point at which they are manufactured is at an excessive height. Therefore, a wide and high suitable temperature range for fixing can be obtained. As a result, the conditions for controlling the temperature of the heat roller of the fixing device in order to achieve sufficient fixing without causing the offset phenomenon have been significantly relaxed, and the offset phenomenon due to non-uniformity of the temperature of the heat roller has been significantly relaxed. It becomes possible to reliably achieve zero good retention without being accompanied by incomplete retention.

Furthermore, by containing the female molding agent in the toner, in addition to the non-offset property of the polyester resin itself due to the polyester resin containing chloroform-insoluble matter, the toner is given non-offset property by the release agent, and therefore, The above-mentioned effects can be obtained with sufficient certainty. That is, the softening point of the polyester resin can be kept low and the offset generation temperature can be kept high. In addition, in color toners, the chromatic colorant dispersed in the binder resin is generally coarser particles than in black toners, and as a result, the fixed force 2 - smoothness of the surface of the toner image However, the smoothness of the toner particle surface is improved by containing the toner and the curing agent. Therefore, it becomes possible to effectively solve the above-mentioned problem.

If you use a toner that has a strong tendency to be negatively charged, such as the toner that uses the aforementioned polyester resin as a binder, and try to use it as a positively charged toner, for example, Japanese Patent Application Laid-Open No. 53-97435 When using a carrier like the one described, the triboelectric charging ability of the resin to be coated is small;
If the amount of charge is insufficient, capri and toner scattering may occur.
Alternatively, there is a disadvantage that the toner becomes negatively charged and cannot be used as a positively charged toner. However, if the carrier of the present invention is used, the above-mentioned disadvantages do not occur and a positively charged toner having a suitable charge amount can be obtained. There is. As described above, since the color developer of the present invention has a specific resin constituting the toner and the carrier, the toner is given a good friction zone "IL special curve", so it is possible to improve the load distribution of the toner. It is almost unnecessary to add an antiphosphor agent to Cl.As a result, the addition of the charge control agent does not cause a decrease in color tint of the color toner.

[Embodiments of the invention]

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

(Manufacture of toner) First, polyester resin was synthesized by the following method.

9229 g of terephthal, polyoxypropylene (2,
2) 211 g of -2t2-bis(4-hydroxyphenyl)propane and 82 g of pentaerythritol were mixed and warped at 200°C, and four types of resins with different chloroform insoluble content were synthesized by varying the reaction time. Shina. As the reaction time increases, the chloroform-insoluble content of the resulting resin increases, and the softening point (Ts) of the resin also increases. The chloroform-insoluble content and softening point of the resulting resin are
It looked like a table. The chloroform-insoluble content was measured by the method described above, and the softening point was measured by a Koka type flow tester (manufactured by Takasu Seisakusho).

Resin 1 and Resin 2 in Table 1 contain chloroform-insoluble matter within the range of non-invention, whereas Resin 3. @fat 4 is a comparative sample with too little and too much total chloroform-insoluble content, respectively.

A two-component active toner using the above four resins as a binder was prepared according to the formulation shown in Table 2. Manufactured by Hoechst Japan Co., Ltd. 2) Mold release agent, polypropylene, manufactured by Sanyo Kasei Co., Ltd. Weigh out the resin, colorant, and additives according to Table 2, mix them in advance with a Henschel mixer for 7J, then melt-knead with an extruder and cool. After pulverization and classification, two types of toners were produced for the examples and two types for the comparative rows, each having an average particle size of about 12 μm.

(Manufacture of carrier) Carrier A Vinylidene heptadide-tetrafluoroethylene copolymer r''V
T-100J C copolymerization 4 # ratio 80:20
, IN's viscosity IfO, 95 dt/g) (Daikin Industries, Ltd. Exhibition) and 6 g of methyl methacrylate copolymer "Acrivet MFJ (manufactured by Mitsubishi Rayon Co., Ltd.) were mixed in a 500% acetone-methyl ethyl ketone (1:1) mixed solvent. Prepare a coating solution by dissolving the carrier core material, spherical iron powder rDsP135J (manufactured by Dowa Iron Powder Industries Co., Ltd.) IKg.
The vinylidene fluoride-tetrafluoroethylene copolymer [V
8g of T-1004 and methyl methacrylate copolymer
Carrier B1t- was produced in the same manner as in the production of Carrier A, except that a temporary covering solution was prepared using 4 g of Acrivera) MFJ (manufactured by Mitsubishi Rayon Co., Ltd.).

Carrier C Said vinylidene hepta-tetrafluoroethylene copolymer "V
Carrier C was produced in the same manner as in the production of Carrier A, except that the coating was prepared using 10 g of T-100J and 2 g of methyl methacrylate copolymer "Acrivera" MFJ (Mitsubishi Rayon Co., Ltd.).Carrier D Fluoride Molar ratio of vinylidene and tetrafluoroethylene is 75:
9 g of vinylisofluoride/-tetrafluoroethylene copolymer (intrinsic viscosity 0.86 dt/g) obtained by the reaction in step 25
and methyl methacrylate and styrene in a molar ratio of 70:3.
Carrier D was produced in the same manner as in the production of Carrier A, except that 3 g of the methyl-4-styrene copolymer was used for the methacrylate obtained by the reaction in Example 0.

Carrier E Vinylidene fluoride and tetrafluoroethylene in a molar ratio of 90:
7 g of the vinylidene fluoride-tetrafluoroethylene copolymer (intrinsic viscosity [1,14 dt/g) obtained by the reaction in step 10] and the methyl methacrylate copolymer "Acrivet MFJ (
Carrier E was manufactured in the same manner as Carrier A except that 5 g of Mitsubishi Rayon Co., Ltd. fA) was used.

Carrier F Said vinylidene hepta-tetrafluoroethylene copolymer [V
3 g of T-1004 and 1 methyl methacrylate copolymer
Carrier F was manufactured in the same manner as Carrier A except that 2 g was used.

Comparative Carrier A Said vinylidene heptadide-tetrafluoroethylene copolymer "V
Comparative carrier A was made in the same manner as carrier A except that only 12g of T-100J was used and the methyl methacrylate copolymer was not used! A left behind.

Comparative carrier B Vinylidene fluoride and tetrafluoroethylene in a molar ratio of 70:
Carrier A was used in all cases except for the use of fluoride and nylidene-tetrafluoroethylene copolymer obtained by the reaction in step 30.
Himaki Carrier B was dismantled in the same manner as the .

Comparative Carrier C: A carrier obtained by reacting methacrylic dR1,1-dihydroperfluorobutyl and methyl methacrylate in a molar ratio of 80:20, and using the same method as in the preparation of the carrier except that the above-mentioned copolymer was used. Comparative carrier C was manufactured.

(Examples and Comparative Examples) A total of eight kinds of transparent developers were prepared by mixing carriers A to F and toners A and B in the combinations shown in Table 3 at a toner coagulation density of 2. These are "Developer 1" to "FA Developer 8".
”.

-7 Carrier A and comparative toners A and B for comparison.

and comparative carrier A-C and toner A at a toner concentration of 2%.
A total of 5 types of comparative developers were combined with v! 4 were made. These are referred to as "Comparative Developer 1" to "Comparative Developer 5." Using each of the above developers, using an anthandrane pigment as a carrier-generating substance, and using a carbazole derivative as a carrier-transporting substance, a negative charge rU-Bix electrophotographic copying machine equipped with a dual-layer organic photoconductive photoreceptor
Continuous copying of up to 40,000 sheets was performed for each developer using a modified 1600J (manufactured by Konishiroku Photo Industry Co., Ltd.), and the durability of each developer, the quality of the final image, and the filming of the photoreceptor after the test was completed. I looked into it. The results are shown in Table 3.

Next, developer 1.7 and comparative developer 1 shown in Table 3
．． An electronic copying machine r U-Bix that was modified using each of 2 to allow the heat roller temperature of the fixing unit to be freely changed and set.
1600j (manufactured by Konishiroku Photo Industry Co., Ltd.), we conducted an actual photographic test by changing the temperature of the above heat roller, measured the minimum temperature of the heat roller at which the offset phenomenon begins to occur, and the minimum temperature at which a constant accumulation is possible, and determined the offset. The generation temperature and the lowest foot M temperature were determined. The results are shown in Table 4. Note that the N-leg device used in the above tests had a heating roller surface layer made of Teflon (manufactured by DuPont) and an opposing roller surface layer made of silicone rubber rKE-1300RTVj (manufactured by Shin-Etsu Chemical Co., Ltd.).

It is clear from the results of the 4th and above that the non-inventive Example had excellent both % developability and fixability, and
It was possible to obtain a high-quality copy image with a high image 11 degree and no fog. On the other hand, in the comparative example, it was not possible to obtain a high-quality copy image in general.In Comparative Example 1 The toner is MG'jru binder 6I.
Since the chloroform-insoluble content of the fat is too small, good results cannot be obtained in all properties, and in particular, durability and fixing properties are poor. In Comparative Example 2, since the chloroform-insoluble content of the binder resin in the toner was excessive, there was no problem in terms of durability, but the image density was low.

In addition, the low-temperature fixing device was expensive and it was not possible to obtain good low-temperature fixing properties. In Comparative Example 3, since the coating layer in the carrier consists only of the vinylidene fluoride-tetrafluoroethylene co-enriched composite, the adhesion to the core material at break 6t/if is insufficient, resulting in poor durability. . In Comparative Example 4, the polymerization molar ratio of the vinylidene fluoride-tetrafluoroethylene copolymer constituting the carrier plate skin was outside the range of the present invention, and the durability and image f! Slightly inferior in terms of # strength and filming on the photoreceptor. In Comparative Example 5, the polymer constituting the coating layer of the carrier was outside the non-inventive range, and the friction band 1t was suitable for toner! ! F properties could not be imparted, and fogging occurred from the initial stage of copying.

Claims (1)

[Scope of Claims] 1) A color developer for developing electrostatic images comprising a carrier and a color toner formed by dispersing a chromatic colorant in a binder resin, wherein the carrier is vinylidene fluoride-tetrafluoride. The color toner has a coating layer mainly composed of a polyethylene copolymer (polymerization molar ratio of 75:25 to 95:5), and the binder resin of the color toner contains a polyester resin with a chloroform insoluble content of 5 to 25% by weight. A color developer for developing electrostatic images. 2) The color developer for developing electrostatic images according to claim 1, wherein the color toner contains 1 to 10 parts by weight of a release agent based on 100 parts by weight of the binder resin.