JPS60123855A - Heat-fixing toner - Google Patents

Abstract

PURPOSE:To obtain a toner superior in offset resistance and fixability and capable of forming a high-quality image by using a binder resin made of a styrene- acrylic type copolymer, and a releasing agent made of a low mol.wt. PP or PE. CONSTITUTION:The present toner contains a colorant, at least a releasing agent made of a low mol.wt. PP or PE, and a binder resin of a styrene-acrylic copolymer contg. an alpha.beta-unsatd. ethylenic monomer as the structural unit, preferably having a weight average mol.wt. of 50,000-300,000, a number average mol.wt. of 10,000-50,000, and a mol.wt. distribution of 3-30.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-fixing toner used in electrophotography, electrostatic recording, electrostatic printing, and the like.

As a developer for developing an electrostatic charge image formed on an image carrier (ZnO photoconductor, Se photoconductor, organic photoconductor, etc.), for example, a two-component system in which magnetic carrier particles and torch particles are mixed is used. A developer or a one-component magnetic one-to-one particle consisting of one to one particle mainly composed of a resin and a magnetic powder are generally used.

Further, the toner image obtained by development is fixed as it is or after being transferred onto a transfer sheet such as plain paper, to obtain a final image.

] ~ The fixing method for the toner image is an oven fixing method in which the toner image is passed through a heated atmosphere using an electric heater.

A heat roll fixing method in which the image is passed between a pair of rolls, at least one of which is a heated roll, and a pressure fixing method in which the image is passed between a pair of rigid rolls at room temperature are known.

Among these fixing methods, the heated roll fixing method has high thermal efficiency when fusing the toner image onto the fixing substrate because the surface of the heating roll and the toner image holding surface on the fixing substrate come into pressure contact. Since it has extremely high viscosity and can perform fixing quickly, it is especially suitable for image forming apparatuses intended for high-speed copying.
Very suitable.

In the hot roll fixing method, since the toner comes into pressure contact with the heated roll surface in a heated and molten state, a portion of the toner adheres to the roll surface and re-adheres to the fixing substrate, staining the image. -There is a drawback that it is easy to cause a phenomenon. Therefore, as a method to prevent the offset phenomenon, for example, the surface of the heating roll is formed of a heat-resistant mold release material such as fluororesin or silicone rubber, and the surface is further coated with an offset prevention liquid such as silicone oil. A method is used in which the roll surface is coated with a thin film of the liquid by supplying the liquid.

This method has drawbacks such as heating of the liquid, which generates an odor, and the need for an extra-large device for supplying the liquid, making the structure of the fixing device complicated.

Therefore, various toners have been proposed in order to obtain a good fixed image without the occurrence of 71 offset without supplying an offset prevention liquid such as silicone oil. For example, Tokuko Showa 52! -3304, 52-3305, 5
No. 7-52574, No. 53-15655 and No. 58
Each publication of No. 12580 describes a toner containing a colorant, a styrene resin, and a specific release agent. Also,
Japanese Patent Publication No. 55-6895 discloses that a resin containing α/β-unsaturated ethylenic monomer as a constituent unit and having a molecular weight distribution within a predetermined range is contained as a main resin component. Toner is listed.

However, although the known methods 1 to 6 above (e) are satisfactory in terms of high offset resistance and low fixing temperature, further improvements have been desired.

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner for heat fixing which eliminates the drawbacks of the above-mentioned prior art, has excellent anti-offset properties and fixing properties, and provides a high-quality fixed image.

The composition of the heat fixing toner of the present invention is such that the heat fixing toner contains at least a resin, a colorant, and a release agent, and the resin is a styrene compound containing an α/β-unsaturated ethylene monomer as a constituent unit. The mold release agent is made of an acrylic copolymer, and the release agent is a heat fixing material made of at least low molecular weight polypropylene and low molecular weight (6) polyethylene.
It is in.

First, in the heat fixing method using a heated roll, in order to prevent offset, the molecular weight distribution of the resin, that is, ffi!
average molecular weight (hereinafter referred to as MW)/number average molecular weight (hereinafter referred to as y
It is necessary to increase i10 of (referred to as n).
well known. On the other hand, in the case of a styrene-acrylic copolymer, the molecular weight distribution of the resin synthesized by the usual m method is 2. o (However, Gail Permini 1--John
(measured by chromatography, hereinafter the same) or more: 11' 7 I? 1- Many have a preventive effect. Therefore, in the present invention, the molecular weight distribution is 2.
．． A styrene/acrylic copolymer having a value of 0 or more (preferably 4.0 or more) is used as the resin component.

Examples of the α/β-unsaturated ethylenic monomer for forming the styrene/acrylic copolymer used in the present invention include styrene, 0-methylstyrene, p-methylstyrene, and α-methylstyrene.

p-ethylstyrene, 2,4-dimethylethylene.

p-n-butylstyrene, p-tetr-butylstyrene, p-n-hexylstyrene, 0-11-octylstyrene, D-11-nonylstyrene, p-methoxystyrene, p-phenylstyrene, 1)-chlorostyrene, Styrenes such as 3,4-dichlorostyrene, vinylnaphthalenes, methyl acrylate, ethyl acrylate, and 11-butyl acrylate.

Isobutyl acrylate, butyl acrylate, acrylic, n-octyl acrylate, dodecyl acrylate, lauryl acrylate, acrylic H2-J tylhenitosyl, stearyl acrylate, 2-chloroethyl acrylate, acrylic acid, nyl, α- Methyl chloroacrylate, methacrylic 6g-7"lopyl, n-butyl methacrylate, isobutyl methacrylate.

Examples include α-methylene fatty acid monocarboxylic acid erthers such as n-ocdyl methacrylate, dodecyl methacrylate, stefuryl methacrylate, phenyl methacrylate, dimedylaminoedyl methacrylate, and diethylamine ethyl methacrylate. It will be done.

In the present invention, copolymers of the above-mentioned styrenes and α-methylene aliphatic monocarboxylic acid esters can be used, but
The weight average molecular weight m is 50,000 to 3ooooo, and the number average molecular weight is 1ooooo to 5o.

00, those with a molecular weight distribution of 3 to 3o are preferable, particularly,
Weight average molecular weight of 150,000 to 27,000, 2,500
Those having a number average molecular weight of 0 to 35,000 and a molecular weight distribution of 4 to 15 are effective.

However, when using a crosslinked resin, molecular weights outside the above range are also effective.

Further, in the present invention, in order to improve the offset resistance of the toner, the release agent is added in a weight of 1 to 15 wt ω % in the total m of the toner. As the mold release agent used in the present invention, there are known aliphatic compounds such as fatty acid 11/i group resins, fatty acid metal salts, higher fatty acids, fatty acid esters, or partially saponified products thereof, but in particular, Single molecule (weight average molecular injury 100
0 to 10,000) is effective.

Specifically, a combination of low-molecular ω polypropylene and low-molecular old polyethylene (Jl) is suitable, and such a combination U can improve the offset resistance of the toner.

Any suitable pigment and/or dye can be used as a colorant in the dyes 1 to 1 according to the present invention. For example, carbon black and aniline blue.

Calco oil pull, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow,
Methylene blue chloride, phthalocyanine blue, methylene, Makkai 1-green oxalate, lamp black, rose bengal.

Known dyes include nigrosine dyes and metal-containing (C'') azo dyes.

Further, when the toner of the present invention is made to have magnetism, in place of some or all of the above-mentioned colorants, iron oxides such as magnetite, hematite, and ferrite, magnetic metals such as cobalt, nickel, and manganese, and magnetic metals such as cobalt, nickel, and manganese may be used. - of alloys, etc.
Echi's magnetic material fine powder may also be used. Here, the content of the magnetic powder is suitably in the range of 20 to 80% by weight based on the total amount of the toner.

The toner of the present invention can be mixed with a carrier such as iron powder or ferrite powder and used as a two-component developer (however, the toner may contain magnetic powder), or can be used as a two-component developer (however, the toner may contain magnetic powder). It can also be used as a monotoner.

In addition, the toner images 1 to 1 formed on the fixing sheet using the toner of the present invention have good heat resistance without offset, without the need to supply offset prevention liquid to the surface.
- Roll fixing is possible, but as a heating roll for fixing,
For example, a metal roll whose surface is coated with a fluororesin such as diethylene tetrafluoride resin, or a roll made of relatively hard silicone rubber can be used.

Example 1 Styrene-〇-butyl methacrylate (MW = 220
000, Mn = 20000.7Q = 60°C), polypropylene (Visco-5-550P manufactured by Sanyo Chemical Co., Ltd.), polyethylene (AC poly 1 ethylene 6△ manufactured by Allied Chemical Co., Ltd.)
), 15 each of carbon black (Mitsubishi Kasei #44) Onibi negative charge type dyed Saito (71 Lien 1-Chemical ￥ JE83)
Using the former, the following professional created six types of 1 to ner as shown in Table 1.

First, the raw materials are heated to a temperature of 140°C using a pressure kneader.
- After being kneaded and solidified by cooling, the mixture was pulverized in a Geno 1-mill and then classified to obtain a toner having an average particle size of about 15 μm.

Table 1 Six types of developers were prepared by mixing 5 parts by weight of each of the above-mentioned toners with 95 parts of iron powder carrier (EFV200/300 manufactured by Nippon Iron Powder Co., Ltd.), and using these developers, commercially available When the images were evaluated using an electrophotographic copying machine, the results shown in Table 2 were obtained. The offset property was evaluated visually in comparison with the case where a transfer paper without a dove image was fixed.

Table 2 As is clear from Table 2, toners Nos. 1 to 3 have good offset resistance, but toners Nos. 1 to 6, which contain only either polypropylene or polyethylene, have good offset resistance. , resistance to off-friction 1~ at nominal temperature of 220'C
It was slightly inferior in quality.

Example 2 Subolene-acrylate copolymer (MW=22000
0, MI+ =20000. TO=60°C).

Boria] Pyrene (Viscol 550P manufactured by Sanyo Chemical Co., Ltd.),
Using the raw materials of polyethylene (Wax C manufactured by Kist) and magnetic powder (EPT 500 manufactured by IB Industries),
Six types of toners shown in Table 3 were prepared according to the following process.

First, the raw materials were thoroughly kneaded at a temperature of 140° C. using a pressure kneader, solidified by cooling, and then finely pulverized using a jet mill. Next, 0.6 parts by weight of finely powdered silica (Aerosil [) 72, manufactured by Nippon Aerosil Co., Ltd.] was added to the finely pulverized powder, and the mixture was dry-mixed at room temperature. went. Next, 0.5 parts by weight of finely powdered silico was added and mixed, and then classified to have a particle size of 5 to 2.
0μ magnetic toner is IS.

Table 3 Using these magnetic toners, image evaluation was carried out on an experimental copying machine using a selenium photoreceptor with an outer diameter of 120 mmφ and a circumferential speed of 100/5ea), and the results are shown in Table 4. . Development is carried out using symmetrical 12-pole magnetization, with a magnetic roll having a magnetic force of 600G on a stainless steel sleeve with an outer diameter of 31.4 mm, and the sleeve in the same direction as the photoreceptor (but at the developing gear 17), respectively. 120 Or,
Avoid rotating at p, m and 100r, p, Ill, and set the development gap and doctor gear 17 to 0, 45 n+mJ3 and 0.35 mm, respectively.
I did it. For fixing, use a fixing machine equipped with a heating roll whose surface is coated with Teflon (trade name), and heat the Ll-roll surface to 170"C to 100+11111/Se.
The fixing speed was c.

Table 4 As is clear from Table 4, No. 7-9 dobuts have good A foot resistance, but 1-nera containing only polypropylene or polyethylene. teeth,
At 240°C, the offset resistance slightly decreased.

As described above, the present invention provides a heat-fixing solution containing at least a resin, a coloring agent, and a mold release agent, in which the resin contains styrene as an α/β-unsaturated ethylenic constituent unit. Since it is made of an acrylic copolymer and the preforming agent is made of low molecular weight polypropylene and low molecular weight polyethylene, it has the effect of providing a layer of offset resistance and fixing property, as well as obtaining a high quality fixed image. .

patent applicant Hitachi Metals Co., Ltd.

Claims (1)

[Claims] In a heat fixing toner containing at least a resin, a colorant, and a release agent, the resin is composed of a styrene-acrylic copolymer contained as an α,β-unsaturated ethylenic unit, and the release agent is 1. A 1-ner for heat fixing, wherein the molding agent comprises at least low molecular weight polypropylene and low molecular weight polyethylene.