JP2546237C - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrostatic image developing toner used for developing an electrostatic latent image in electrophotography and electrostatic recording, and more specifically, The present invention relates to a method for producing a novel function-separated toner suitable for a heating roll fixing system. [Prior art] Electrophotography uses a photoconductive material such as selenium as a photoconductor, forms an electrostatic latent image by various means, and attaches toner to the latent image by a magnetic brush developing method or the like. After the toner image is transferred to a transfer material such as paper or sheet,
The image is fixed using a solvent, pressure and the like to obtain a permanent image. As a method of fixing a toner image, a heat melting method is most often used, but this method is roughly classified into two types, a non-contact type and a contact type. Because it is excellent and can perform high-speed fixing, it is widely used in recent commercial copying machines, printers, and the like. [Problems to be Solved by the Invention] However, this heating roll fixing system also has some disadvantages. As a particularly serious disadvantage, it is pointed out that the amount of energy, that is, the amount of electric power used is considerably larger than that of the pressure roll fixing system. Of course, the fixing strength of the fixed image on the transfer material such as paper is much better in the heated roll fixing method than in the pressure roll fixing method, and also excellent in terms of paper deformation, wrinkles, etc. due to pressure. Therefore, many researchers have studied how to reduce the power consumption in the heating roll fixing method, in other words, how to lower the minimum temperature required for fixing the toner. One of the most influential means for achieving this object is to lower the glass transition temperature of the binder resin of the toner by several tens of degrees from the glass transition temperature that is generally used. However, this method has a fatal drawback that the blocking resistance and fluidity of the toner are significantly impaired. Conventionally, the following two measures have been proposed to compensate for these drawbacks. The first measure is to improve the anti-blocking property and fluidity of the toner by attaching very fine colloidal silica, alumina, titania and the like to the toner surface. This measure does not raise the minimum fixing temperature of the toner so much,
Improvements in blocking resistance and fluidity were also achieved to some extent, which seemed to be a good measure at first glance. However, even if these fine particles are subjected to a heat treatment or the like in order to fuse them to the toner surface, they are easily released from the toner surface, and the photoreceptor, particularly the photoreceptor whose surface is coated with an organic polymer or the like, It has been found that it has a bad effect on etc. That is, these fine particles are semi-permanently fixed on the surface of the photoreceptor after many uses, resulting in an inconvenience of causing image defects. Therefore, this measure is not a radical solution. A second measure is to improve the anti-blocking property and fluidity by forming a continuous layer of various polymers on the toner surface. This measure makes it possible to properly select the material of the surface coating continuous layer.The effect of improving the blocking resistance and fluidity is remarkable, and can be a drastic improvement measure as compared with the above-mentioned fine particle addition method. The presence of the layer hinders heat conduction from the surface of the heat roll to the binder resin, which is a main component of the toner, and consequently considerably raises the minimum fixing temperature of the toner, thereby lowering the original minimum fixing temperature. It has become clear that this creates a totally inconvenient inconvenience. Further, these disadvantages are common to both the non-contact type heat fusing method and the pressure roll fixing method, and improvement is desired. The present inventors have conducted various studies and studies in order to improve the above-mentioned disadvantages of the conventional toner, and as a result, have found that a toner produced by a specific production method gives a good result for solving the above disadvantages of the toner. SUMMARY OF THE INVENTION Accordingly, it is a main object of the present invention to provide a method for producing a heat fixing toner which can be fixed with less power consumption, in other words, at a lower temperature. Another object of the present invention is to provide a method for producing a heat fixing toner having good blocking resistance and fluidity. Another object of the present invention is to provide a method for producing a heat fixing toner which is excellent in triboelectrification, image properties, life, and other properties. [Means for Solving the Problems] That is, the present invention provides a method for heat-treating a toner and particles of a toner composition containing a resin and a compound having a lower critical surface energy than the resin. It is an object of the present invention to provide a method for producing a high-concentration toner. Materials having significantly different critical surface energies are incompatible with each other, and physical phenomena in which low critical surface energy compounds are concentrated on the surface, that is, outside, are generally known, but the present inventors consider this phenomenon in the production of toner. By applying it, it is easy to obtain a toner with a low surface energy compound concentration near the surface higher than the inside, and the spontaneous multi-layered toner thus obtained can control the chargeability and fluidity by the surface layer and the inner layer. It has been found that the toner is extremely useful as a function-separated toner in combination with the fixing property of the toner. The binder resin used in the present invention is an ordinary binder resin for toner, and includes styrenes such as styrene, chlorostyrene and vinyl styrene; monoolefins such as ethylene, propylene, butylene and isobutylene; vinyl acetate and propionic acid Vinyl esters such as vinyl, vinyl benzoate and vinyl butyrate; methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate,
Esters of α-methylene aliphatic monocarboxylic acids such as phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether; vinyl methyl ketone; Examples thereof include homopolymers or copolymers of vinyl ketones such as vinyl hexyl ketone and vinyl isopropenyl ketone. Particularly typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, and styrene- Examples include alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyethylene, and polypropylene. Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin, and waxes. Examples of toner colorants include carbon black, nigrosine dye, aniline blue, calcoil blue, chrome yellow, ultramarine blue, dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, Rose Bengal or the like can be exemplified as a typical example. The binder resin and the colorant are not limited to those exemplified above. Also, a magnetic material can be used. As the compound having a 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 the fluorine-containing compound include the following. That is, a polymer containing fluorine in the main chain, for example, a homopolymer such as tetrafluoroethylene, trifluoroethylene, vinylidene fluoride, monofluoroethylene, hexafluoropropylene or these monomers and ethylene, propylene, butylene, or chloride. Copolymers with vinyl, vinylidene chloride, trifluoroethylene, and other copolymerizable unsaturated bond-containing monomers are exemplified. Further, a polymer of a monomer having fluorine in a side chain is also preferable. In particular, a fluorine-containing alkyl acrylate or a fluorine-containing alkyl methacrylate is a typical monomer, and specifically, acrylic acid or methacrylic acid, 1,1-dihydroperfluoroethyl, 1,1-dihydroperfluoropropyl, 1,1-dihydroperfluorohexyl, 1,1-dihydroperfluorooctyl, 1,1-dihydroperfluorodecyl, 1,1-dihydroper Fluorolauryl, 1,1,2,2-tetrahydroperfluorobutyl, 1,1,2,2-tetrahydroperfluorohexyl, 1,
1,2,2-tetrahydroperfluorooctyl, 1,1,2,2-tetrahydroperfluorodecyl, 1,1,2,2-tetrahydroperfluorolauryl, 1,1
, 2,2-tetrahydroperfluorostearyl, 2,2,3,3-tetrafluoropropyl, 2,2,3,3,4,4-hexafluorobutyl, 1,1, ω-trihydroperfluorohexyl, 1,1, ω-trihydroperfluorooctyl, 1,1,
1,3,3,3-hexafluoro-2-fluoropropyl, 3-perfluorononyl-
2-acetylpropyl, 3-perfluorolauryl-2-acetylpropyl, N-
Perfluorohexylsulfonyl-N-methylaminoethyl, N-perfluorohexylsulfonyl-N-butylaminoethyl, N-perfluorooctylsulfonyl-N-methylaminoethyl, N-perfluorooctylsulfonyl-N-ethylaminoethyl, N-perfluorooctylsulfonyl-N-butylaminoethyl, N
-Perfluorodecylsulfonyl-N-methylaminoethyl, N-perfluorodecylsulfonyl-N-ethylaminoethyl, N-perfluorodecylsulfonyl-N
Ester compounds such as -butylaminoethyl, N-perfluorolaurylsulfonyl-N-methylaminoethyl, N-perfluorolaurylsulfonyl-N-ethylaminoethyl, N-perfluorolaurylsulfonyl-N-butylaminoethyl and the like. Can be The following can be used as the component copolymerized with the fluorinated alkyl acrylate or the fluorinated alkyl methacrylate. That is, styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, alkylstyrene such as octylstyrene, fluorostyrene, chlorostyrene bromostyrene, dibromo Halogenated styrenes such as styrene and iodostyrene, and styrene-based monomers such as nitrostyrene, acetylstyrene and methoxystyrene; acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid, α-methylcrotonic acid, α-ethylcroton Addition-polymerizable unsaturated aliphatic monocarboxylic acids such as acid, isocrotonic acid, tiglic acid, ungeric acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid Addition-polymerizable unsaturated aliphatic dicarboxylic acids such as glutaconic acid and dihydromuconic acid; the above-mentioned addition-polymerizable unsaturated carboxylic acids and alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol; Octyl alcohol, nonyl alcohol, dodecyl alcohol, tetradecyl alcohol, alkyl alcohols such as hexadecyl alcohol, and these alkyl alcohols are partially alkoxylated, methoxyethyl alcohol, ethoxyethyl alcohol,
Alkoxyalkyl alcohols such as ethoxyethoxyethyl alcohol, methoxypropyl alcohol, ethoxypropyl alcohol, benzyl alcohol,
Esters with aralkyl alcohols such as phenylethyl alcohol and phenylpropyl alcohol, alkenyl alcohols such as allyl alcohol and crotonyl alcohol, particularly alkyl acrylates, alkyl methacrylates, alkyl fumarates, alkyl maleates Esters and the like are preferred examples; amides and nitriles derived from the above-mentioned addition-polymerizable unsaturated carboxylic acids; aliphatic monoolefins such as ethylene, propylene, butene and isobutylene; vinyl chloride, vinyl bromide, vinyl iodide, , 2-dichloroethylene, 1
, 2-dibromoethylene, 1,2-diiodoethylene, isopropenyl chloride, isopropenyl bromide, allyl chloride, allyl bromide, vinylidene chloride, vinyl fluoride,
Halogenated aliphatic olefins such as vinylidene fluoride; 1,3-butadiene, 1
Conjugated diene-based aliphatic diolefins such as 2,3-pentadiene, 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2,4-hexadiene and 3-methyl-2,4-hexadiene; Vinylpyridine, 4-vinylpyridine, 2-vinyl-6-methylpyridine, 2-vinyl-5-methylpyridine, 4-butenylpyridine, 4-pentylpyridine, N-vinylpiperidine, 4-vinylpiperidine, 4-vinylpiperidine, N-vinyldihydropyridine, N-vinylpyrrole,
2-vinylpyrrole, N-vinylpyrroline, N-vinylpyrrolidine, 2-vinylpyrrolidine, N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone, N-
Examples thereof include nitrogen-containing vinyl monomers such as vinyl carbazole. These can be used alone or in combination of two or more. Further, a fluorinated epoxy resin, a fluorinated polyester resin, a fluorinated silicon resin, or the like can be used. Further, fluorine-containing non-polymer compounds, for example, fluorine-based coupling agents such as fluorine-containing alkoxysilane, fluorine-containing titanium acylate, fluorine-containing alkoxytitanium, fluorine-containing alkoxyzirconium, etc .; A surfactant and other non-polymer compounds containing a fluorine atom can be used. As the silicon compound, a so-called modified silicone varnish modified with an alkyd resin, a phenol resin, an epoxy resin, or the like can be used in addition to typical polymethylphenylsiloxane and polydimethylsiloxane. In order to form a multilayer containing a low surface energy compound as a coating layer or a layer containing a high concentration on the surface of toner particles, generally known microencapsulation method, for example, a polymerization catalyst is supported on the core surface, Polymerize other monomers from place
in situ polymerization method, orifice method in which a polymer substance is dropped into a curing solution to cure the outer wall, simple, composite coacervation method in which a thick polymer layer is separated from a water-soluble polymer solution to form a wall film on a core, Aerial suspension coating method in which the core is suspended in the air by a fluidized bed, and the wall material liquid is injected and mixed while rotating and flying in the air flow, and encapsulated, high-speed disk rotating type, two-fluid nozzle type, pressurized nozzle Introducing the core polymer solution mixture into the formula admixer, spray drying with hot air drying after admizing, other known interfacial polymerization methods, submerged drying method, melt dispensing method, powder bed method, vacuum deposition plate cover It is also possible to use an electrostatic coalescence method or an electrostatic coalescence method. In order to uniformly multiply and encapsulate the entire toner surface by these methods, it is necessary to increase the thickness of the coating layer to some extent. Therefore, when the toner is multi-layered by the above method, various characteristics of the toner,
Particularly, it has a bad influence on the fixing property. On the other hand, according to the method of the present invention for heat-treating the toner composition particles, it is possible to form an extremely thin layer uniformly on the carrier surface. The basic concept of the toner production method of the present invention is to use a high-temperature atmosphere to cause a compound having a lower critical surface energy than a binder resin to be present at a high concentration on the carrier surface, thereby fixing the toner and preventing blocking. Of the conventional function-separated microcapsule toner in terms of smoothness of surface, uniformity of coating layer thickness, and the ability to make the thickness thinner. It is much better than the method. The method of the present invention can be roughly classified into the following two methods. The first method is to prepare a toner to which a low critical surface energy compound is added by a conventional method. This is a method of performing heat treatment. Specifically, (i) a method in which the heat treatment is performed by leaving the resin to stand at a temperature lower than the glass transition temperature of the resin for a long time, for example, in an oven or the like. For example, there are (ii) a method in which a heat treatment is performed when suspended in air using a fluidized bed, and (iii) a method in which a heat treatment is performed using a heating sphering apparatus. In the second method, heat treatment is performed at the time of formation of the toner particles to transfer the low critical surface energy compound to the toner surface. Specifically, a mixture containing a resin, a low critical surface energy compound, and a magnetic powder as essential components, and further adding other optional components is heated and melt-mixed. This is a production method of cooling and solidifying by cooling. [Effects of the Invention] The toner according to the method of the present invention, in which the composition particles containing a low surface energy compound are heat-treated and the compound is concentrated on the surface, has good blocking resistance, good fluidity, and low-temperature fixability. Since it is remarkably excellent, it has an excellent advantage that it has excellent powder characteristics as compared with a toner using a special additive, but does not have any adverse effect on a photoreceptor or the like. Further, as compared with a toner having a normal capsule structure, the toner exhibits remarkably excellent low-temperature fixability and good chargeability. EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited by the following Examples. In the following description, all parts are parts by weight. Example 1 Styrene / n-butyl acrylate / divinylbenzene copolymer (glass transition temperature 55 ° C.) 80 parts N-perfluorooctylsulfonyl-N-ethylaminoethyl methacrylate / styrene polymer 10 parts Polypropylene wax 3 parts Carbon black 7 parts The compound having the above composition was kneaded with a Banbury mixer, pulverized and classified, and then left in an oven at 42 ° C. for 20 days to obtain a toner according to the present invention. Example 2 A toner having the same composition as in Example 1 was treated at 48 ° C. for 3 hours using a tumbling fluidized bed instead of stopping the oven heating to obtain a toner according to the present invention. Comparative Example 1 A toner having the same composition as in Example 1 was used as a control toner without heat treatment. Example 3 Polyester resin (resin consisting of bisphenol A · ethylene oxide adduct, hydrogenated bisphenol A, maleic acid and having a glass transition point of 58 ° C.) 90 parts Copolymer of perfluorooctylethyl methacrylate and methacrylic acid 2 parts Carbon black 8 parts The above composition was kneaded and pulverized by a conventional method, and then heated and spherical using a thermal sphering apparatus to obtain a toner according to the present invention. Comparative Example 2 A control toner was obtained without subjecting the toner of Example 3 to thermal spheroidization. Comparative Example 3 10% by weight of colloidal silica (R-972, manufactured by Texa) was added to the toner of Comparative Example 2.
Was added to obtain a control toner. Comparative Example 4 A toner was obtained by a conventional method using a composition obtained by removing the copolymer of perfluorooctylethyl methacrylate and methacrylic acid from the composition of Example 3, and 50 parts of this toner was mixed with perfluorooctylethyl methacrylate. After mixing with 500 parts of a 5% by weight solution of a methacrylic acid copolymer in trichlorotrifluoroethane, the mixture was spray-dried to obtain a control microcapsule toner. A developer was prepared by mixing 3 parts of each toner obtained in Examples 1 to 3 and Comparative Examples 1 to 4 with 100 parts of a ferrite carrier having an average particle diameter of 100 μm coated with a methyl methacrylate polymer. This developer was subjected to a fixing and copying test using an FX-2830 machine (manufactured by Fuji Xerox Co., Ltd.). The results are as shown in the following table, and it can be seen that the toners of the examples are more excellent in fluidity, anti-blocking property and the like than the toners of the comparative examples.

Claims (1)

Claims: A composition comprising a resin and a fluorine compound or a silicon compound having a lower critical surface energy than the resin, wherein the composition particles contain 2 to 10 parts by weight per 100 parts by weight of the toner. A method for producing a toner having a high critical surface energy compound surface concentration.