JPS6353561A - Thermal fixing toner - Google Patents

Abstract

PURPOSE:To obtain the titled toner capable of fixing with lesser power consumption by spraying a melt of the toner material contg. a resin and a compd. having lower critical surface energy than that of the resin as an essential component, followed by cooling it. CONSTITUTION:The melt of the toner material contg. the resin and the compd. having lower critical surface energy than that of the resin as the essential component is spraied, followed by cooling it. The usable binding resin is the resin usually used in the toner, and is exemplified by a homopolymer or a copolymer of the styrenes such as styrene and chlorostyrene, etc., and a monoolefins such as ethylene and propylene, etc. In particular, the represenative binding resin is exemplified by polystyrene and a copolymer of styrene- alkylacrylate, etc. The coloring matter of the toner is exemplified by carbon black and a nigrosine dyestuff, etc. The compd. having the low critical surface energy is preferably exemplified by a fluorine compd. or a silicon compd.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a toner for developing an electrostatic image used for developing an electrostatic layer in electrophotography and electrostatic recording, and more specifically, toner for developing an electrostatic image. For example, the present invention relates to a novel functionally separated toner suitable for a heated roll fixing method.

[Conventional technology]

Electrophotography uses a conductive substance such as selenium as a photoreceptor, forms an electrostatic image by various means, and then attaches toner to this latent image using a magnetic brush development method or the like to visualize it. After this toner image is transferred to a transfer material such as paper or a sheet, it is fixed using heat, solvent, pressure, etc. to obtain a permanent image.

The most commonly used method for fixing toner images is the heat-melting method, which is roughly divided into two types: non-contact and contact M-type. In particular, the contact-type heated roll fixing method has a high thermal efficiency. It is widely used in commercial copying machines, printers, etc. in recent years because it can be fixed at a single point and can be fixed at high speed.

[Problem that the invention seeks to solve]

However, this heated roll fixing method also has some drawbacks. A particularly serious drawback is that the amount of energy, i.e., electric power, used is considerably greater than that of the pressure roll fixing method.

Of course, the heating roll fixing method is far superior to the pressure roll fixing method in terms of mechanical strength for transfer materials such as paper, and it is also superior in terms of paper deformation and wrinkles caused by pressure. Therefore, many researchers have been studying how to reduce the power consumption in heated roll fixing systems, or in other words, how to reduce the minimum temperature required for toner fixing.

One of the most effective means for achieving this objective is to lower the glass transition temperature of the binder resin of the toner by several tens of degrees below the glass transition temperature normally used. However, this method has the fatal drawback of significantly impairing the blocking resistance and fluidity of the toner.

The following two measures have been proposed to compensate for these shortcomings.

The first approach is to improve the blocking resistance and fluidity of the toner by attaching very fine colloidal silica, alumina, titania, etc. to the toner surface. This strategy did not significantly increase the minimum fixing temperature of the toner, and some improvement in anti-blocking properties and flowability was achieved - and appeared to be a good solution. However, even if heat treatment is applied to fuse these fine particles to the toner surface, they are likely to be released from the toner surface. It was found that these fine particles had an adverse effect on the body, etc. When used many times, these fine particles were semi-permanently stuck on the surface of the photoreceptor, causing an inconvenience that caused image defects. Therefore, this one-size-fits-all solution cannot be called a fundamental solution.

The second strategy is to form a continuous layer of various polymers on the toner surface to improve blocking resistance and fluidity. This method can significantly improve blocking resistance and fluidity if the material for the surface coating continuous layer is selected appropriately, and can be a drastic improvement compared to the above-mentioned fine particle addition method. The existence of a continuous layer inhibits heat conduction from the heat roll surface to the binder resin, which is the main component of the toner, and as a result, the minimum fixing temperature of the toner increases considerably, and the original purpose of lowering the minimum fixing temperature is It has become clear that this causes inconveniences that are completely contrary to the above.

Further, these disadvantages are common to the non-contact heat-melting fixing method and the King Calor fixing method, and improvements are desired.

Therefore, the main objective of the present invention is to
In other words, the objective is to provide a heat fixing toner that can be fixed at a lower temperature.

Another object of the present invention is to provide a heat fixing toner having good blocking resistance and fluidity.

Another object of the present invention is to provide a toner for heat fixing that has excellent triboelectric charging properties, image quality, life span, and other properties.

[Means for solving problems]

As a result of various studies and examinations on the problems of the conventional heat fixing toner described above, the present inventors have found that a composition containing a low critical surface energy compound in the binder resin is heat-treated, and the surface has a low critical surface energy. The present invention was completed based on the discovery that a toner containing a relatively high concentration of surface energy compounds solves all of the above problems.

That is, the present invention provides a heat fixing toner obtained by spraying and cooling a melt of a toner material containing a resin and a compound having a lower critical surface energy than the resin as essential components.

Materials with a significant critical surface energy are mutually incompatible;
Although the physical phenomenon in which low critical surface energy compounds are concentrated on the surface, that is, on the outside, is generally known, the present inventors have discovered that a method of spray cooling a molten toner material has a high concentration of low critical surface energy compounds on the surface layer. We have discovered that this is effective in promoting density, and the resulting spontaneously multilayered toner is extremely useful as a functionally separated toner that combines control of chargeability and fluidity by the surface layer with fixation by the internal resin. It turned out to be.

The binder resin used in the heat fixing toner of the present invention is a resin for ordinary toners, including styrenes such as styrene, chlorostyrene, and vinylstyrene; heptanoolefins such as ethylene, propylene, butylene, and isobutylene; vinyl acetate; Vinyl esters such as vinyl propionate, vinyl benzoate, vinyl butyrate; methyl acrylate, ethyl acrylate, modified butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate , esters of α-medelene aliphatic monocarboxylic acids such as dodecyl methacrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropenyl keto/etc. Polymers or copolymers can be exemplified, and typical binding at
Examples of bh include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyethylene, and polypropylene. can be mentioned.

Further examples include polyester, polyurethane, epoxy resin, polyamide, modified rosin, paraffin, and waxes.

Toner colorants include carbon black, nigrosine dye, aniline blue, carcoyl blue, chrome yellow, ultramarine blue, Typhon oil red, monoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, and rose. Bengal can be exemplified as a representative example.

The binder resin and colorant are not limited to those exemplified above.

However, magnetic materials can also be used.

As the compound with low critical surface energy used in the present invention, a fluorine-based compound or a silicon-based compound is suitable, and various compounds can be mentioned.

Examples of fluorine-containing compounds include the following.

In other words, polymers containing fluorine in the main chain, such as homopolymers such as evatetrafluoroethylene, trifluoroethylene, vinylidene fluoride, monofluoroethylene, hexafluoropropylene, or these monomers and ethylene, propylene, butylene. , vinyl chloride, vinylidene chloride, trifluoroethylene, and copolymers with other copolymerizable unsaturated bond-containing monomers.

Polymers of compounds having fluorine in the parent side chain are also suitable, and representative monomers include fluorinated alkyl acrylates or fluorinated alkyl methacrylates,
Specifically, acrylic acid or methacrylic acid, 1,1-
Dihydroperfluoroethyl, 1. X-dihydrobar 70
loprovir, 1,1-cyhydrovar-70 lohexyl, 1
．． l-dihydroperfluorooctyl, 1,1-dihydroperfluorodecyl, l,1-dihydroperfluorolauryl, 1.1.2.2-tetrahydroperfluoroobutyl,
1,1゜2.2-tetrahydroperfluorohexyl, 1
．． 1,2゜2-tetrahydroperfluorooctyl, 1,
1,2.2-f trahydroper 70 lodecyl, 1,1,
2.2-tetrahydrover 70 lolauryl, 1,1,2
．． 2-tetrahydroperfluorostearyl, 2,2,3
．． 3-tetrafluoropropyl, 2,2,3,3,4.
4-hexafluorobutyl, 1,1. ω-trihydroperfluorohexyl, 1.1. ω-trihydroper70-octyl, 1.1°1.3,3.3-hexafluoro-2-
Chloropropyl, 3-bar 70 nonyl-2-acetylpropyl, 3-perfluorolauryl-2-acetylpropyl, N-perfluorohexylsulfonyl-N-methylaminoethyl, N-half 0 hexylsulfonyl-N
-Butylaminoethyl, N-perfluorooctylsulfonyl-N-methylaminoethyl, N-perfluorooctylsulfonyl-N-dithylaminoethyl N -Half octylsulfonyl-N-butylaminoethyl, N
- Bar 70 Rotenlesulfonyl-N-methylaminoethyl, N-perfluorodecylsulfonyl-N-ethylaminoethyl, N-perfluorodecylsulfonyl-N-butylaminoethyl, N-perfluorolaurylsulfonyl-
Various ester compounds such as N-methylaminoethyl, N-perfluorolaurylsulfonyl-N-ethylaminoethyl, N-bar70lorolaurylsulfonyl-N-butylaminoethyl and the like can be mentioned.

As the component to be copolymerized with the fluorinated alkyl acrylate or fluorinated alkyl methacrylate, the following can be used.

Styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, dimethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene, alkylstyrene, 70-styrene, chlorostyrene, Halogenated styrenes such as bromostyrene, dibromoethylene, and iodostyrene, as well as styrenic septamers such as nitrostyrene, acetylstyrene, and methoxystyrene; acrylic acid, methacrylic acid,
Addition-polymerizable unsaturated aliphatic monocarboxylic acids such as α-ethyl acrylic acid, crotonic acid, α-methylcrotonic acid, α-ethylcrotonic acid, isocrotonic acid, tiglic acid, ungellic acid, maleic acid, fumaric acid, itaconic acid , citraconic acid, mesaconic acid, glutaconic acid, dihydromuconic acid, and other addition-polymerizable unsaturated aliphatic dicarboxylic acids; the addition-polymerizable unsaturated carboxylic acids and alcohols, such as methyl alcohol, ethyl alcohol, flobyl alcohol,
Alkyl alcohols such as methyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, dotecyl alcohol, tetradecyl alcohol, hexadecyl alcohol, and partially alkoxylated versions of these alkyl alcohols, such as methoxyethyl alcohol and ethoxyethyl Alcohol, alkoxyalkyl alcohol such as ethoxyethoxyethyl alcohol, methoxypropyl alcohol, ethoxypropyl alcohol, benzyl alcohol,
Esterified products with aralkyl alcohols such as phenylethyl alcohol and phenylpropyl alcohol, alkenyl alcohols such as allyl alcohol and crotonyl alcohol, especially acrylic acid alkyl esters, methacrylic acid alkyl esters, fumaric acid alkyl esters, maleic acid alkyl esters, etc. are preferred examples; amides and nitrites derived from the addition-polymerizable unsaturated carboxylic acids; aliphatic monoolefins such as ethylene, propylene, butene, and isobutylene; vinyl chloride,
Vinyl bromide, vinyl iodide, l,2-dichloroethylene, 1,2-dibromoethylene, 1,2-short ethylene, impropenyl chloride, isopropenyl bromide, allyl chloride, -j%7'Jl, chloride Halogenated aliphatic olefins such as vinylidene, vinyl fluoride, vinylidene fluoride: 1,3-phtadiene, 1,3-pentadiene, 1
．． Conjugated diene aliphatic diolefins such as 3-butadiene, 2,3-dimethyl-1,3-butadiene, 2,4-hexadiene, 3-methyl-2,4-hexadiene; 2
-vinylpyridine, 4-vinylpyridine, 2-vinyl-
6-methylpyridine, 2-vinyl-5-methylpyridine/
, 4-butenylpyridine, 4-pentylpyridine, N-
Vinylpiperidine, 4-vinylpiperidine, 4-vinylpiperidine, N-vinyldihydropyridine, N-vinylvirol, 2-vinylpyrol, N-vinylpyrroline,
N-vinylpyrrolidine, 2-vinylpyrrolidine, N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone,
Examples include nitrogen-containing vinyl monomers such as N-vinylcarbazole. These can be used alone or in combination of two or more.

Fluorinated epoxy resin, fluorinated polyester resin, fluorinated silicone resin, etc. can be used.

In addition, fluorine-containing non-polymer compounds such as fluorine-containing alkoxysilane, fluorine-containing titanium acylate, fluorine-containing alkoxytitanium, fluorine-containing alkoxyzirconium, etc., fluorine-containing coupling agents, fluorine-containing surfactants, and others. The following fluorine atom-containing non-polymer compounds can be used.

As the silicon compound, in addition to typical polymethylphenylsiloxane and polydimethylsiloxane, so-called modified silicone resins modified with alkyd resins, phenol resins, epoxy resins, etc. can also be used.

The heat fixing toner of the present invention has the above-mentioned binder resin and a compound having a lower critical surface energy than this resin as essential components, and the desired (and other optional components) are added thereto and heated and melted to form a mixture thereof. It is produced by a method in which it is sprayed without solidifying, and then cooled and solidified using a relatively low-temperature air stream.

More specifically, the manufacturing equipment includes a heating melt mixing device and a kneaded material viscosity adjustment tank as pre-treatment equipment, a pump that conveys the kneaded material to the spraying device, and a cooling tower that cools and solidifies the sprayed mixed material. It is configured.

A kneader, roll mill, Banbury, sand mill, attritor, Henschel mixer, etc. can be used as a heating and melting mixing device, and a nozzle or disc type spray device is used to obtain toner with small particle size. These are suitable, but are not limited to.

A major factor in the shape and surface properties of toner is the liquid viscosity of the kneaded product during spraying, but in order to obtain a toner that is perfectly spherical and has a high surface smoothness, the liquid viscosity at the time of melting must be 150.
It is preferable to set the temperature to 100 PS or less at a temperature of °C.

〔Effect of the invention〕

The toner for heat fixing of the present invention, which is obtained by melting a toner material containing a resin and a compound with a critical surface energy lower than that of the conventional resin as essential components and spraying and cooling it, has good anti-blocking properties and fluidity, and can be used at low temperatures. Since it has extremely excellent fixing properties, it has an excellent advantage over toners using special additives in that it has soaked powder properties and does not have any adverse effects on the photoreceptor or other parts. Furthermore, it exhibits much superior low-temperature fixability compared to conventional toners having a capsule structure.

〔Example〕

Hereinafter, the toner of the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited to the following examples. In addition, all parts in the following Example 1 represent parts by weight.

Examples Polyester (bisphenol A/ethylene oxide adduct, prepared from hydrogenated bisphenol A and maleic anhydride, Tg = 50°C) 87 parts bar 70 lohexylethyl methacrylate copolymer
4 parts carbon black
After kneading 9 parts of the above-mentioned composition in a pressurized knead, the melt was sprayed using a spray dryer, cooled and solidified, and then classified to obtain a toner having an average particle size of 18 μm.

Comparative Example 1 A control toner was obtained in the same manner as in Example 1 except that the perfluorohexylethyl methacrylate copolymer was removed from the formulation in Example 1.

Comparative Example 2 Using the formulation of Example 1, the mixture was kneaded in a kneader, cooled and solidified, and then crushed and classified in a conventional manner to obtain a control toner.

3 parts of each of the toners obtained in Examples and Comparative Examples U and 2 were coated with a methyl methacrylate polymer with an average particle size of 10.
A developer was prepared by mixing with 100 parts of 0 μm ferrite carrier.

Use this developer using FX-2830 machine (manufactured by Fuji Xerox).
A fixing and copying test was conducted using the following.

The results are shown in the table below, and it can be seen that the toner of the example has better flowability of 2 and blocking resistance than the toner of Comparative Example 1.2.

1) Blocking resistance: 5 of toner particles after 24 hours of eating
The temperature at which 01i% no longer passes through a 105 μm sieve.

2) Minimum fixing@degree: The minimum heat roll surface temperature required for fixing.

Claims (1)

[Claims] A heat fixing toner obtained by spraying and cooling a melt of a toner material that essentially contains a resin and a compound having a lower critical surface energy than the resin.