JPS5859455A - Electrostatic image developing toner - Google Patents

Abstract

PURPOSE:To obtain a toner meltable at low temp. on the sheet to which a toner image is to be fixed, by adding a plasticizer having a specified melting point to a mixture of a colorant, a styrene resin, and a low mol.wt. polymer of propylene, butene, pentene, or the like. CONSTITUTION:A toner contains a colorant, a styrene resin, a low mol.wt. polymer of propylene, butene, pentene, hexene, heptene, octene, nonene, or decene, and 1-45pts.wt. plasticizer per 100pts.wt. of the resin component of the toner, having 40-140 deg.C m.p. As said plasticizer, e.g., cyclohexyl phthalate, diphenyl phthalate, triethylene glycol dibenzoate, etc. are used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner for developing pre-images in electrophotography, electrostatic recording, electrostatic printing, etc.

The methods for developing static W1 images can be roughly divided into two types: one in which pigments and dyes of each type of yuzu are finely dispersed in an insulating organic liquid. A liquid development method using a ψ agent, a cascade method, a bristle brush method, a magnetic brush method, an impression method, a powder cloud method, and other methods are used. There is a so-called dry development method using a powder developer, and the present invention relates to a toner used in the latter dry development method.

Generally, toner deteriorates after being developed several thousand times due to mechanical abrasion due to shearing force and impact force applied during mechanical operations in a developing device. To prevent this kind of toner deterioration,
It would be possible to use a strong resin with a large molecular weight that can withstand mechanical abrasion as a material for the toner, but these resins generally have a high melting point and are difficult to produce toner by pulverizing them. It is. Therefore, in order to attach a toner containing a single point of high resin to a sheet to be fixed, for example, if a non-contact heating device using an electric furnace is used as a fixing device, this fixing device has low thermal efficiency, so it is not enough. It is necessary to operate at a higher temperature without proper fixing. Therefore, the power consumed for fixing increases, and the sheet to be fixed becomes discolored or burnt, and the fixing speed is also limited.On the other hand, if a pressure and heating device using a heated roller is used as the fixing device, this device will Since the heating roller surface and the toner image surface of the fixing sheet come into pressure contact, thermal efficiency is extremely high, and compared to non-contact heating devices, it has the advantage of being able to fix quickly with less thermal energy. Toner tends to adhere to the heating roller surface when it comes into pressure contact with the image surface, causing so-called offset development. To prevent this phenomenon, the heating roller surface is made of a material such as a fluorine-based resin that is releasable to the toner. It is necessary to form the mold using a superior material, and it is also necessary to supply a mold release agent such as silicone oil to the surface of the heating roller by means such as coating. Furthermore, fluorine-based resins are generally non-conductors when it comes to heat, so in order to fix toners containing resins with high melting points at a higher speed, it is necessary to keep the temperature of the heating roller high. It is necessary to increase the supply of thermal energy. However, fluorine-based resins deteriorate rapidly when used continuously at high temperatures and under carts.
For example, Teflon (Desl2 Company'll1), which is a typical fluorine-based resin, has a limited durability.
It must be used at temperatures between 230°C and below. There are also difficulties in using silicone oil at high temperatures, and the lubricating materials for the bearings of heating rollers and pressure rollers are also subject to heat resistance limitations. Furthermore, in order to maintain the temperature of the heating roller at a high temperature, a large amount of electric power is required, and a power distribution from a special power source is required.

On the other hand, if a resin with a relatively small molecular weight is used as a component of the toner, the donor image can be fused to the temporary adhesion sheet at a relatively low temperature. A film tends to form on the side surface of the developer carrier, deteriorating the obtained image and shortening the life of the photoconductor and the developer carrier. A further drawback is that they tend to cake or agglomerate during storage or mechanical operation.

It is an object of the present invention to be able to fuse onto a pre-adhesive sheet at a relatively low temperature, not form a film on the photoconductor surface or developer carrier surface, to withstand mechanical abrasion, and to be able to be fused at a constant temperature with a heated roller. It is an object of the present invention to provide a toner for developing an electrostatic image that can be fixed at high speed without causing an offset phenomenon when it is fixed using a fixing device.

The present inventors have proposed (a) a coloring agent, (b) a styrene resin, (c) a low molecular weight polymer of propylene, butene, pentene, hexene, heptene, octene, nonene, or decene, and It has been found that a toner for developing an electrostatic image containing a plasticizer having a melting point of 100 mL achieves the above object.

By using the toner for developing electrostatic images according to the invention, it is possible to fix the toner image at a relatively low temperature using a contact heating device, particularly preferably a heated roller fixing device, so that it can be applied to small consumer vehicles. can be fused more quickly with force,
Furthermore, by using a material with a low heat resistance limit as the material for the heating roller, it is possible to significantly improve its durability, which also has the advantage of making it easier to design an ultra-high speed copying machine. .

Any suitable pigment or dye may be used as a colorant in the toner according to the invention. Even Gma Carbon Black, Nigrosine Dye, Ayu 1J Npuru, Calco Oil Blue, Chrome Yellow, Ultramarine Blue,
DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanin blue, malachite green offsalate, lamp black, rose bengal and mixtures thereof are used to color the toner so that it can form a visible image upon development. It is necessary to contain the toner in an amount sufficient to achieve the desired effect.

In the toner according to the present invention, a styrene resin is used as a resin component. The styrene resin may be a homopolymer of styrene, or a copolymer of styrene and other vinyl yarn monomers.

Monomers for forming these copolymers include p-chlorostyrene, vinylnaphthalene, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and isobutylene, such as vinyl chloride, vinyl bromide, and vinyl fluoride. , vinyl acetate, vinyl propionate,
Vinyl esters such as vinyl benzoate and vinyl butyrate, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloro-ethyl acrylate, acrylic i! ! ! phenyl, esters of α-methylene aliphatic monocarboxylic acids such as methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile aphrylate, e.g. vinyl methyl ether , vinyl ethers such as vinyl ethyl ether, vinyl isobutyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone, etc. N-vinyl compounds, etc., and one or more of these can be copolymerized with a styrene monomer. Suitable styrenic resins have an average molecular weight of about 3000 or more;
Its styrene content is 41%! Preferably, it is at least about 25% by weight, based on the total weight of fat.

A thermoplastic resin system in which a styrene resin is mixed with other resins can also be used as the resin component of the toner according to the present invention. Other resins that can be mixed with styrenic W+ include vinylnaphthalene, such as vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate,
Vinyl esters such as vinyl pensoate and vinyl butyrate, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, and acrylic esters. ! In-octyl, acrylic acid 2
- Esters of α-methylene aliphatic monocarboxylic acids such as chloro-ethyl, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile,
methacrylonitrile, acrylamide, vinyl ethers such as vinyl methyl ether, vinyl isobutyl ether, vinyl ethyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone, such as H-vinylpyrol, N-vinylcarbazole , a homopolymer obtained by polymerizing monomers such as N-vinyl compounds such as N-vinylindole and N-vinylpyrrolidene, a copolymer obtained by copolymerizing a combination of two or more of these monomers, or, for example, a rosin-modified polymer. Non-vinyl thermoplastic resins include phenol-formalin resin, oil-modified epoxy resin, polyurethane resin, cellulose resin, and polyether resin. When these resins are used in combination with styrenic resins, the amount of styrene present is such that at least about 25% by weight of the styrene component is present, based on the total weight of the resin being mixed. It is preferable to mix both. The reason for this is that it has increased resistance to mechanical abrasion and has excellent mold releasability against heated rollers.

The toner according to the present invention contains at least one compound selected from the following compound group. These compounds play the role of preventing the offset phenomenon caused by adhesion of the silver to the surface of the heating roller, and are generally contained in an amount of 1 to 25 parts by weight per 100 parts by weight of the resin component of the toner. is desirable.

The compound group is a low molecular weight olefin polymer, and is an olefin polymer or copolymer containing only an olefin as a monomer component, or an olefin copolymer containing a monomer other than olefin as a monomer component a. It is a combination and has a relatively low molecular weight. Olefins as monomer components include, for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, or olefins with different positions of unsaturated bonds. or analogues thereof, such as 3-methyl-1-butene, 3-methyl-2-pentene, 3-propyl-5-methyl-2-hexene, etc., into which an alkyl group is introduced as a branched chain. It includes any olefins such as. In addition, examples of monomers other than olefin that form a copolymer with olefin include vinyl methyl ether,
Vinyl ethers such as vinyl-n-butyl ether and vinyl phenyl ether, vinyl esters such as vinyl acetate and vinyl butyrate, such as vinyl fluoride, vinylidene fluoride, tetrachloroethylene, vinyl chloride, vinylidene chloride,
Haloolefins such as tetrachloroethylene, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, steryl methacrylate, N,M-dimethyl-monoethyl methacrylate , acrylic esters or methacrylic esters such as t-butylaminoethyl methacrylate, acrylic type conductors such as acrylonitrile, N,N-dimethylacrylamide, etc., such as acrylic acid, methacrylic acid, maleic acid, fumaric acid , organic acids such as itaconic acid, diethyl 7-malate,! - Can raise various things such as pinene.

The weight average molecular weight of these low molecular weight olefins is 10
000 or less is effective, especially about 3000 to 8
Those having a weight average molecular weight of 0.000 are effective in the present invention. Generally, those having a large molecular weight have low compatibility and dispersibility with styrenic resins, and are therefore not desirable for use in the present invention.

The toner according to the present invention contains a plasticizer having a melting point of about 40 to 140°C. This plasticizer plays the role of lowering the fusing temperature of the toner, and also has the role of lowering the fusing temperature of the toner.
) and (iii), it plays a role in improving the dispersibility of various additives such as dyes and pigments in the toner. Furthermore, it is possible to prevent the toner from forming a film on the surface of the photoconductor or the carrier on the development side, and also to prevent the toner from caking or agglomerating during storage or machine operation.

Examples of such plasticizers include, for example, dicyclohexyl 7-talate, which is an ester of 0-7 tar acid or 1-7 tar acid, diphenyl 7-talate, dihydroabiethyl 7-talate, jetoxyethyl 7-thaleate, and dimethyl iso-7 tallate. , triethylene glycol dibenzoate, which is an ester of benzoic acid, pentaerythritol tetrabenzoate, saccharose benzoate, glyc7lyl tribenzoate, tricyclohexyl citrate, which is an ester of citric acid, and p-)luenesulfone, which is an ester of citric acid. Amide, N-ethyl-p-)luenesulfonamide, N-cyclohexyl-p-)luenesulfonamide, triphenyl phosphate which is a phosphoric acid ester, chlorinated paraffin, chlorinated polyphenyl, polyethylene glycol, etc. can be mentioned.

The amount of stiff plasticizer contained in the toner is 1 to 45 parts by weight, preferably 2 to 20 parts by weight, per 100 parts by weight of the resin component of the toner.

Various other toner additives can be added to the toner according to the present invention, if necessary.

The toner image formed on the fixing sheet using the toner according to the present invention does not cause the toner offset phenomenon even when a fixing roller that does not supply offset prevention liquid to the surface of the fixing roller is used, and the temperature is relatively low. This allows for efficient and good heating roller constant adhesion. As a fixing roller, its surface may be made of, for example, Teflon, Fluon (manufactured by Kokosha), Kel-? Products with a smooth surface made of fluorine-based resin such as (manufactured by 3M) or relatively hard silicone rubber such as KX-1300R〒V (manufactured by Shin-Etsu Chemical Co., Ltd.), or those with a metal surface in some cases, are effective. used.

The present invention will now be illustrated by examples, but the embodiments of the present invention are not limited thereto. In the examples, the number of copies is expressed by weight unless otherwise specified.

Example 1 80 parts of Picolastic D-125 (manufactured by Esso Petrochemical Co., Ltd., styrene resin), 20 parts of Eslec BL-1 (manufactured by Tanesui Chemical Co., Ltd., polyvinyl, butyral tree IJil),
1557 parts of Peerless, 3 parts of Oil Black BW (manufactured by Orient Chemical Co., Ltd.), and poly-2-methyl-butene-1
(Average molecular weight: 5000) 5 parts were prepared and used as a sample. A toner was prepared as a comparative sample in exactly the same manner as described above, except that pentaerythritolte F rapenzoate was not added.

These two toners were brought into pressure contact using a fixing roller whose surface was made of Teflon (manufactured by DuPont, polytetrafluoroethylene) to fuse and fix the toner images. As a result, the temperature G at which the toner fuses to the fixing sheet was 180°C when the comparison sample toner was used, or 180°C when the sample toner was used.
The temperature was 55°C.

When the fixing operation was repeated and the occurrence of the toner offset phenomenon was observed, it was found that no offset phenomenon occurred with any of the toners.

Example 2 Copolymer of about 90 parts styrene and about 10W6 dimethylaminoethyl methacrylate with a softening point of 120°C
100 parts of Diablack 8H (manufactured by Mitsubishi Kasei Corporation, carbon black), and ethylene-propylene copolymer (copolymerization molar ratio 50:50, weight average molecular weight 40
00) and 15 parts of tricyclohexyl citrate) were mixed and treated in the same manner as in Example 1 to prepare a toner and use it as a sample.

A toner was prepared as a comparison sample in exactly the same manner as described above, except that trisichexyl citrate was not added.

Using these two types of toners, a fixing roller whose surface was made of Teflon was used to bring the toner images into pressure contact to fuse and fix the toner images.

As a result, the 7M degree at which the toner was fused to the sample was 190° C. when the comparative sample toner was used, but it was 170° C. when the sample toner was used.

When the fixing operation was repeated and the occurrence of the toner offset phenomenon was observed, it was found that no offset phenomenon occurred with any of the toners.

Agent Yoshimi Kuwahara

Claims (1)

[Claims] (a) Colorant, (b) Styrene thread resin, (c) Low molecules of propylene, butene, pentene, hexene, heptene, octene, nonene, or decene! Polymer, Narahini (d)
A toner for developing electrostatic images, characterized in that it contains a plasticizer having a melting point of about 40 to 140°C.