JPS6353559A - Thermal fixing toner - Google Patents

Abstract

PURPOSE:To obtain the toner capable of fixing with lesser electric power consumption by providing a layer contg. a fluorine contg. compd. on the surface of the titled toner. CONSTITUTION:The layer contg. the fluorine contg. compd. is provided on the surface of the titled toner. Namely, the titled toner having good anti- blocking property and fluidity and fixing property at a low temp. is obtd. by incorporating the fluorine contg. compd. for example, the fluorine contg. low mol.wt. compd., and the fluorine contg. polymer, etc. to near the surface of the toner. Namely, said titled toner is incorporated said compd. to the toner so as to be relatively high concentration at the inner part of >=1mum away from the surface of the toner by means of a various kinds method. The usable compd. is a polymer contg. a fluorine atom in a main chain of the molecule, such as a homopolymer of tetrafluoroethylene or trifluoroethylene etc., or a copolymer of said monomer and ethylene, propylene, butylene, vinyl chloride, vinylidene chloride, trifluoroethylene or another monomer having a copolymerizable unsatd. bond.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an electrostatic charge developing toner used for developing an electrostatic latent image in electrophotography and electrostatic recording, and more specifically, The present invention relates to an electrostatic charge developing toner suitable for a roll fixing method.

[Conventional technology]

In electrophotography, a photoconductive substance such as selenium is used as a photoreceptor, and an electrostatic latent image is formed by various means.Toner is attached to this latent image using magnetic brush development, etc., and then the image is visualized. After the 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 heating and fusing method, but this method is roughly divided into two types: non-contact type and contact type. In particular, the contact type heated roll fixing method is the most popular in terms of thermal efficiency. Because it is excellent and capable of high-speed fixing, it has been widely used in recent commercial copiers, printers, etc.

[Problem that the invention seeks to solve]

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

Of course, the heated roll fixing method is far superior to the pressure roll fixing method in terms of fixed image strength on transfer materials such as paper, and is also superior in terms of paper deformation and wrinkles caused by pressure. Therefore, many researchers are trying to figure out how to reduce power consumption in the heated roll fixing method.
In other words, studies have been conducted on how to lower the minimum temperature necessary for toner fixation.

One of the most effective means to achieve this goal is to lower the glass transition temperature of the adhesive 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.

Φ In order to compensate for these shortcomings, the following two measures have been proposed.

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 or the like 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 it had a negative effect on That is, after repeated use, these fine particles semi-permanently adhere to the surface of the photoreceptor, resulting in an inconvenience that causes image defects. Therefore, this measure 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 of the continuous surface coating layer is selected appropriately, and may not be a drastic improvement compared to the above-mentioned method of adding fine particles. The existence of the continuous coating 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, resulting in a decrease in the original minimum fixing temperature. It has become clear that this causes inconveniences that completely defeat the purpose.

Therefore, a main object of the present invention is to provide a heat fixing toner that consumes less power and 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 to solve the problem]

The present inventors have discovered the above-mentioned problems of the conventional heat fixing toner.
As a result of extensive research and discussion, it was discovered that a toner having a fluorine-containing compound layer as a toner surface layer provides good results that eliminate all of the disadvantages of conventional toners, and the present invention was completed.

That is, the present invention provides a heat fixing toner having a layer containing a fluorine-containing compound on its surface.

In the present invention, the surface layer containing a fluorine-containing compound refers to a depth of about 1 μm from the toner surface, and the concentration of the fluorine-containing compound near the surface up to this depth is relatively high compared to the inside of the toner. It also includes toner containing a fluorine-containing compound with a concentration gradient. That is, a fluorine-containing compound, such as a fluorine group-containing low molecular weight compound, is present near the surface.
A fluorine group-containing polymer or the like is applied to the inside of the toner, that is, within about 1 μm or more from the toner surface, by various methods.
By using such a method, it is possible to obtain good anti-blocking properties, fluidity, and low-temperature fixing properties.

In the present invention, the reason why a layer containing a fluorine-containing compound is provided as a surface layer of the toner is as follows.

Fluorine-containing compounds have low surface energy and common KJI! The friction coefficient is also low. Therefore, by adding a fluorine-containing compound, the fluidity and blocking resistance of the toner can be improved. However, when these fluorine-containing compounds are uniformly dispersed throughout the toner structure, their contribution to the surface properties is significantly weakened, and no improvement in flowability or anti-blocking properties can be expected.

If the concentration of the fluorine-containing compound is very high relative to the binder resin, there will be no such inconvenience, but on the other hand, there will be problems in the following two points. The first problem is the high cost of using extremely expensive fluorine-containing compounds for multiple electric currents, and the second problem is that it is difficult to obtain appropriate rheology.
In particular, it is difficult to obtain the necessary rheology for heat roll fixing toners.

In view of the above points, it is desirable that the concentration of the fluorine-containing compound be relatively high only in the vicinity of the surface layer.

However, it should be noted that these fluorine-containing compounds
If it is added to the toner surface in the form of a powder, it has the same drawbacks as the fine powder that improves fluidity, and even if it is fused, some of the Since secondary problems caused by free powder (increase in capri, decrease in durability, etc.) are unavoidable, it is desirable that the fluorine-containing compound be present in the binder resin of the toner in a fully contained state.

The fluorine-containing compounds used in the heat fixing toner of the present invention are as follows.

That is, polymers containing fluorine in the main chain, such as Te117
Homopolymers such as ethylene, trifluoroethylene, vinylidene fluoride, monofluoroethylene, hexafluoropropylene, etc., or copolymerizable with these monomers such as ethylene, fluoroethylene, styrene, vinyl chloride, vinylidene chloride, trifluoroethylene, and others A copolymer with an unsaturated bond-containing monomer is produced.

Monomers having fluorine in the side chain are also suitable, and representative monomers include fluorinated alkyl acrylates and fluorinated alkyl methacrylates. Specifically, Ll-dihydroperfluoroethyl of acrylic acid or methacrylic acid, Ll-dihydroperfluoropropyl, Ll-dihydroperfluorohexyl, Ll-dihydroper70looctyl, Ll-dihydroperfluorodecyl, Ll-dihydrono7-70lolauryl, LL2.2
-Tetrahydroper 70 butyl, 1. L2.2-nato2hydroperfluorohequinyl, LL22-tetrahydronofluorooctyl, LLz2-tetrahydroperfluorodecyl, LL2.2-tetrahydrof1-fluorolauryl, LL2.2-tetrahydroper70rostearyl, 2.23 .3-te)? Fluoropropyl, 22:aa4
4-hexafluorobutyl, LLω-trihydroperfluorohexyl, 1. Lω-trihydroperfluorooctyl, LLL: 13-hexafluoro-2-chloropropyl,
3-no(-fluorononyl-2-acetylpropyl, 3-
Perfluorolauryl-2-acetylpropyl, N-perfluorohexylsulfonyl-N-methylaminoethyl,
N-)-70-hexylsulfonyl-N-butylaminoethyl, N-per70-hexylsulfonyl-N-methylaminoethyl, N-perfluorooctylsulfonyl-N-ethylaminoethyl-fh, N-perfluorooctylsulfonyl- N-butylaminoethyl, N-per70 rhodecylsulfonyl-N-methylamineethyl, N-perfluorodecylsulfonyl-N-ethylaminoethyl, N-
Perfluorodecylsulfonyl-N-7'thylaminoethyl N-perfluorolaurylsulfonyl-N-methylamineethyl, N-7safelorolaurylsulfonyl-N
Examples include ester compounds such as -ethylaminoethyl and N-perfluorolaurylsulfonyl-N-7'thylaminoethyl.

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

That is, styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene, alkylstyrene, fluorostyrene, chlorostyrene, fluorostyrene, Styrenic monomers such as cyphlomostyrene, iodine, R, fVnatonohalogenated styrene, dinitrostyrene, acetylstyrene, methoxystyrene; acrylic acid, methacrylic acid, α-ethyl acrylic acid, crotonic acid, α-methyl 01 synthetic unsaturated aliphatic monocarboxylic acids such as crotonic acid, α-ethylcrotonic acid, isocrotonic acid, tiglic acid, ungelic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesacone cough, glutacone powder, Addition polymerizable unsaturated aliphatic dicarboxylic acid such as dihydromuconic acid;
The addition-polymerizable unsaturated carboxylic acid and alcohol, such as methyl alcohol, ethyl alcohol, flobyl alcohol, methyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, dodecyl alcohol, tetradecyl alcohol, hexadecyl alcohol Nato alkyl alcohol, partially alkoxylated versions of these alkyl alcohols, methoxyethyl alcohol, ethoxyethyl alcohol, ethoxyethoxyethyl alcohol, methoxypropyl alcohol, ethoxypropyl alcoholNato alkoxyalkyl alcohol, benzyl alcohol, phenylethyl alcohol, phenylpropyl Preferred examples include alcohols such as alkenyl alcohols such as tonoaralkyl alcohol, allyl alcohol, and crotonyl alcohol, and tonoesterified products, particularly acrylic acid alkyl esters, methanomono-acid alkyl esters, fumaric acid alkyl esters, and maleic acid alkyl esters. ; Amide and nitrile derived from the addition-polymerizable unsaturated carboxylic acid; ethylene, propylene,
Aliphatic heptanoolefins such as butene and isobutylene; vinyl chloride, vinyl bromide, vinyl iodide, L2-dichloroethylene, L2-dibromoethylene, L2-short ethylene, infrobenyl chloride, inpropenyl bromide, allyl chloride, allyl bromide, Halogenated aliphatic olefins such as vinylidene chloride, vinyl fluoride, vinylidene fluoride; L3-butadiene, 1.3--! Butadiene, L3-
Butadiene, a3-dimethyl-L3-butadiene, 24
Conjugated diene aliphatic diolefins such as -hexadiene and 3-methyl-24-hexadiene: 2-vinylpyridine, 4-vinylpyridine, 2-vinyl-6-methylpyridine, 2-vinyl-5-methylpyridine, 4 -butenylpyridine, 4-pentylpyridine, N-vinylpiperidine, 4-vinylpiperidine, 4-vinylbiyridine, N
-vinyldihydropyridine, N-vinylpyrrole, 2-
? "Nylpyrrole, N-?'Nylpyrrolidine N-vinylpyrrolidine, 2-?"Nylpyrrolidine, N-vinyl-2
Examples include nitrogen-containing vinyl monomers such as -pyrrolidone, N-vinyl-2-biyridone, and N-vinylcarbazole. These can be used alone or in combination of two or more.

Furthermore, 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, Other fluorine atom-containing non-polymer compounds can be used.

In the present invention, there are various methods for providing a layer containing a fluorine-containing compound on the surface, but the commonly used microencapsulation method is, for example, supporting a polymerization catalyst on the core surface and polymerizing other monomers from that location. in 5
itu polymerization method, orifice method in which a polymer substance is dropped into a curing liquid to harden the outer wall, simple and complex core cell elution methods in which a thick polymer layer is layer-separated from a water-soluble polymer solution to form a wall film on the core; The air suspension coating method involves suspending the core in the air in a fluidized bed and spraying and mixing the wall material liquid while rotating in the airflow to encapsulate it.High-speed disc rotation type, two-fluid nozzle type, In addition to the spray drying method in which a core polymer solution mixture is introduced into a pressure nozzle type atomizer and dried with hot air after atomizing, other known interfacial polymerization methods, submerged drying methods, melt dispersion methods, powder bed methods, and vacuum methods are also available. It is also possible to use a vapor deposition coating method or an electrostatic bonding method.

Furthermore, blooming or bleeding methods using different critical surface energies or solution parameters can also be applied.

Examples of the binder resin for the heat fixing toner of the present invention include styrenes such as styrene, chlorostyrene, and vinylstyrene; monoolefins such as ethylene, propylene, butylene, and isobutylene; vinyl acetate; Vinyl esters such as vinyl propionate, vinyl benzoate, vinyl butyrate; methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate , esters of α-methylene aliphatic monocarboxylic acids such as dodecyl methacrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl methyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone; Typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonide, and lyl copolymer. Combined, styrene-
Examples include butadiene copolymer, styrene-maleic anhydride copolymer, polyethylene, and polypropylene.

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

In addition, toner coloring agents include carbon black, nigrosine dye, aniline blue, calcoyl blue, chrome yellow, ultramarine flu, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate,
Representative examples include lamp black and rose bengal.

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

Furthermore, a magnetic toner containing a magnetic material can also be used.

This toner is smaller than about 30 μm, preferably 3 to 3 μm.
Those having an average particle size of 20 μm can be used.

〔Effect of the invention〕

The heat fixing toner of the present invention, in which a layer containing a fluorine-containing compound is provided near the surface of the toner, has good blocking resistance and fluidity, but is extremely excellent in low-temperature fixing properties. It has the excellent advantage of having significantly superior powder characteristics compared to , and having no adverse effect on the photoreceptor or other parts. It also exhibits significantly superior low-temperature fixability compared to toners with conventional capsule structures.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following examples in any way. In addition, in the following examples, all parts represent parts by weight.

Example I LL2.5 g of a low molecular weight copolymer of 2-tetrahydroperfluorooctyl methacrylate and styrene (55,745! quantitative ratio) is dissolved in 295 parts of trifluorotrichloroethane. Add 300 parts of this solution to '! J ester resin (T consisting of bisphenol-A-ethylene oxide adduct, L3-butanediol, glycerin and maleic acid)
g=50°C polymer), 10 parts of carbon black, and 5 parts of polypropylene wax with an average particle size of 1
A toner according to the present invention was obtained by mixing with 100 parts of a 1 μm black toner and using a spray dryer drying device.

Comparative Example 1 A comparative toner was obtained by using the polyester toner of Example 1 without being subjected to the fluoropolymer solution treatment.

Comparative Example 2 Colloidal silica (R-9
72, tE3f Gusasha M)1. A comparative toner was obtained.

Example 2 After kneading, crushing, and classifying 5 parts of the fluoropolymer used in Example 1, 85 parts of the polyester resin used in Example 1, and 10 parts of the carbon black used in Example 1, a thermospheronization device was used. was heated and spheronized using
A spherical toner according to the present invention with a diameter of μm was obtained.

A developer was prepared by mixing 3 parts of each toner obtained in Example L2 and Comparative Examples 1 and 2 with 100 parts of a ferrite carrier coated with a methyl methacrylate polymer and having an average particle size of 100 μm.

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 toners of Examples 1 and 2 are superior to the toner of Comparative Example L2 in terms of fluidity, blocking resistance, and other problems.

1) Blocking resistance: 50 of toner particles! i arrogance is 1
Temperature at which it no longer passes through a 05 μm sieve 2) Minimum fixing temperature: Minimum heat roll surface temperature required for fixing

Claims (1)

[Claims] A heat fixing toner characterized by having a layer containing a fluorine-containing compound on its surface.