JPH0431582B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a negatively chargeable toner for developing electrostatic images used in fields such as electrophotography and electrostatic recording. (Prior Art) As toners for developing electrostatic images used in the fields of electrophotography and electrostatic recording, toners using styrene/acrylic copolymer resin as a binder resin (Japanese Patent Publication No. 1983-1999-1)
11143), etc.), toners using vinyl resins,
Toner using a bisphenol type epoxy resin obtained by reacting bisphenol and epichlorohydrin as a binder resin (Japanese Patent Application Laid-open No. 57-96354),
Toner using a polyester resin obtained by reacting a glycol having a bisphenol skeleton with a polybasic acid as a binder resin (Japanese Patent Publication No. 52-25420)
However, compared to other resins, vinyl resins can be used in the majority of toners because their physical properties such as molecular weight, glass transition point, and melt viscosity can be manipulated over a wide range, which is extremely advantageous in terms of toner design. is dominated by toners using this vinyl resin as a binder resin. In order to give these toners preferable negative chargeability, there is a method of adding a substance that imparts negative chargeability (hereinafter abbreviated as a negative chargeability substance) to the binder resin, such as a metal complex of an azo compound or fine silica powder. (JP-A-57-130049, JP-A-57-136659, JP-A
No. 58-187946, Japanese Patent Publication No. 58-203454). (Problems to be Solved by the Invention) As mentioned above, toners made of styrene/acrylic copolymer resin, which is a vinyl-based binder resin commonly used in the production of toners, are made by converting the polymer into soft vinyl chloride. Adhesion was likely to occur, causing print defects when printed matter was sandwiched between sheets of soft vinyl chloride polymer. Further, when producing a negatively chargeable toner by mixing a negatively chargeable substance into a binder resin, there are the following problems. (1) Negative charge-imparting substances have poor compatibility with binder resins and do not disperse uniformly, so the charge on each toner particle is distributed over a wide range from positive to negative, which tends to cause fogging on fixed images. . (2) Since the negative charge imparting substance is not well mixed with the binder resin, the substance adheres to the carrier surface or photoreceptor surface, causing filming phenomenon, print density change, fogging, and resolution reduction. . (3) Since negatively charged substances are generally colored,
Not suitable for color toner. (Means for Solving the Problems and Their Effects) The present invention provides a negatively charged electrostatic image developing material containing a polymer having a vinyl monomer represented by any of the following structural formulas I to V as a constituent component. Regarding sex toner. (However, in the above formula, R ₁ , X ₁ and X ₂ are each independently hydrogen or a methyl group, R ₂ is an alkylene group having 1 to 6 carbon atoms, R _{3,4,5,6,7,8, 9} and R ₁₀ are each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, halogen, or

[Formula], where R _{11, 12,} and R ₁₃ are each independently hydrogen or an alkyl group having 1 to 3 carbon atoms, and Structural formulas I to V are each

The polymer of the present invention has at least one [Formula]] Among the vinyl monomers represented by the structural formulas I to V, one type of polymer or a copolymer of two or more types, and a combination of these monomers and other vinyl monomers. There is copolymerization with monomers. Preferably, the vinyl monomer represented by the structural formulas I to V is contained in the polymer component of the present invention in an amount of preferably 10% by weight or more, particularly preferably 10 to 90% by weight, and even more preferably 20 to 80% by weight. be done. If this amount is too small, the adhesion resistance and negative chargeability to the soft vinyl chloride polymer tend to be insufficient. Here, other vinyl monomers include styrene, a-methylstyrene, p-methylstyrene,
Styrene derivatives such as pt-butylstyrene and p-chlorostyrene, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, decyl methacrylate , undecyl methacrylate, dodecyl methacrylate, glycidyl methacrylate, methoxyethyl methacrylate, propoxyethyl methacrylate, butoxyethyl methacrylate, methoxydiethylene glycol methacrylate, ethoxydiethylene glycol methacrylate, methoxyethylene glycol methacrylate,
butoxytriethylene glycol methacrylate,
Methoxydipropylene glycol methacrylate,
Phenoxyethyl methacrylate, phenoxydiethylene glycol methacrylate, phenoxytetraethylene glycol methacrylate, benzyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl methacrylate, methacrylic acid N-vinyl-
2-pyrrolidone, methacrylonitrile, methacrylamide, N-methylol methacrylamide,
Ethyl methacrylate morpholine, methacrylic acid 2
-Hydroxyethyl, hydroxypropyl methacrylate, hydroxybutyl methacrylate, 2-hydroxy-3-phenyloxypropyl methacrylate, diacetone acrylamide, acrylic acid,
Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, acrylic acid Glycidyl, methoxyethyl acrylate, propoxyethyl acrylate, butoxyethyl acrylate, methoxydiethylene glycol acrylate, ethoxydiethylene glycol acrylate, methoxyethylene glycol acrylate, butoxytriethylene glycol acrylate, methoxydipropylene glycol acrylate, phenoxyethyl acrylate , phenoxydiethylene glycol acrylate, phenoxytetraethylene glycol acrylate, benzyl acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, N-vinyl acrylate -2-pyrrolidone, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, 2-hydroxy-3-phenyloxypropyl acrylate, glycidyl acrylate, acrylonitrile, acrylamide, N-methylol acrylamide, diacetone acrylamide, Vinyl monomers having one vinyl group in each molecule such as ethyl acrylatemorpholine and vinylpyridine, divinylbenzene, reaction products of glycol and methacrylic acid or acrylic acid, such as ethylene glycol dimethacrylate, 1,3-
Butylene glycol dimethacrylate, 1,4-
Butanediol dimethacrylate, 1,5-pentanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, Hydroxypivalic acid neopentyl glycol ester dimethacrylate, trimethylolethane trimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, trismethacryloxyethyl phosphate, bis(methacryloyloxyethyl)hydroxyethyl isocyanate nurate, tris(methacryloyloxyethyl) isocyanurate, ethylene glycol diacrylate, 1,3
-butylene glycol diacrylate, 1,4-
Butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, tripropylene diacrylate, hydroxy Neopentyl pivalate glycol diacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, penerythritol triacrylate, pentaerythritate tetraacrylate, trisacryloxyethyl phosphate, bis(methacryloyloxyethyl)
Hydroxyethyl isocyanurate, tris(methacryloyloxyethyl)isocyanurate,
Half esters of glycidyl methacrylate and methacrylic acid or acrylic acid, half esters of bisphenol type epoxy resin and methacrylic acid or acrylic acid, half esters of glycidyl acrylate and methacrylic acid or acrylic acid, etc. Vinyl monomers having more than one vinyl group can be mentioned. Among these vinyl monomers, particularly preferred vinyl monomers having one vinyl group in one molecule include styrene, styrene derivatives, methacrylic esters, acrylic esters, etc.
In particular, alkyl esters of methacrylic acid or acrylic acid having 1 to 5 carbon atoms in the alkyl group are preferred. For vinyl monomers having two or more hinyl groups in one molecule, divinylbenzene,
Preferred are dimethacrylate and dinacrylate of methylene glycol having 2 to 6 carbon atoms,
These are used in an amount of 0 to 20% by weight based on the total vinyl monomers. These vinyl monomers having one vinyl group in one molecule and vinyl monomers having two vinyl groups in one molecule can be used alone or in combination of two or more. The above vinyl monomer can be polymerized by solution polymerization, bulk polymerization,
Polymerization can be carried out by any method such as emulsion polymerization or suspension polymerization. Polymerization initiators used in the polymerization of vinyl monomers include acetyl peroxide, decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, P-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, and perdicarbonate. Diisopropyl, di-2-ethyl-hexyl perdicarbonate, acetylcyclohexane sulfonyl peroxide, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, peracetic acid, tert-butyl, tert perisobutyric acid -butyl, azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, tert-butyl per-2-ethylhexanoate, tert-butyl perbenzoate, and other known polymerization initiators. . Preferably, these are used in an amount of 0.1 to 15% by weight, based on the total amount of vinyl monomers.
Moreover, it is preferable to use it by dissolving it in a vinyl monomer. The polymer preferably has a glass transition point of 40 to 40.
The temperature is 120°C, particularly preferably 50 to 100°C.
If the glass transition point is too low, caking will easily occur during toner storage or in the developing machine, and
Toner tends to become fine powder due to friction and collisions in the developing machine. On the other hand, if the glass transition point is too high, it becomes difficult to crush, making it difficult to crush during toe production, and the fixing strength to the transfer material tends to decrease. In the present invention, the above polymer is used as a binder resin, but other polymers may also be used in combination. Other polymers include polymers or copolymers of other vinyl monomers mentioned above, KR-
216, KR-220, KR-152, KR-271, KR-255
(Manufactured by Shin-Etsu Chemical Co., Ltd.), SR-2400, SR-
Silicone resins such as 2406, SH-840 (manufactured by Toray Silicone Co., Ltd.) or Nosolex (cdF)
norbornene polymers such as C-200A, C-250A (manufactured by Mitsubishi Chemical Corporation), etc.
polyester carbonates such as Iupilon-1000 (manufactured by Mitsubishi Gas Chemical Co., Ltd.); Epicote 604, 1004, 1007, 1009, 1010, YL-903,
906 (manufactured by Ciel), Epomitsuku R304, R307,
Epoxy resin such as R309 (manufactured by Mitsui Petrochemical Industries, Ltd.) or Nitzpol BR1220, 1032,
Diene resins such as 1441, IR2200, NBR2057S, 2007J (manufactured by Nippon Zeon Co., Ltd.) or
There are polyester resins such as ATR2005, 2009, and 2010 (manufactured by Kao Soap Co., Ltd.), phenol resins, coumaron resins, amide resins, amide imide resins, butyral resins, amino resins, urethane resins, etc., and these other polymers are used in toners. It is used in the range of 0 to 30% by weight. The toner of the present invention contains a colorant and/or magnetic powder. Coloring agents include carbon black, acetylene black, Hansa Yellow G, cadmium yellow, molybdenum orange, permanent orange, red iron oxide, rhodamine lake B, first violet B, methyl violet lake, dark blue, phthalocyanine blue, chrome green, and pigment. Green B, zinc oxide, titanium oxide, nigrosine dye, methylene blue, rose bengal, xinoline yellow, ultramarine blue, chrome yellow, aniline blue, calco oil blue, rhodamine 6G lake, watching red barium, watching red strontium , malachite green oxalate, Dupont Oil Red, and mixtures thereof, which are present in the toner at 1%.
It is preferable to use it in an appropriate amount within the range of 60% by weight. When the toner of the present invention is used as a one-component toner, magnetic powder is added. Magnetic powders include metal powders such as iron, manganese, nickel, and cobalt, aluminum, cobalt,
steel, lead, magnesium, nickel, tin, zinc,
Alloys and mixtures of metals such as antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, aluminum oxide, iron oxide, copper oxide, nickel oxide, zinc oxide, titanium oxide, magnesium oxide, Metal compounds containing metal oxides such as chromium oxide, or alloys that exhibit ferromagnetism when heat treated, such as whisker alloys such as manganese-copper-aluminum, manganese-copper-tin, etc., can be used. It can be contained in an amount of 30 to 70% by weight. The particle size of the magnetic powder is preferably 10 μm or less, particularly preferably 1 μm or less. In the case of a one-component toner, generally no colorant is added, but the colorant may be added in an amount of 10% by weight or less in the toner. The toner for developing an electrostatic image according to the present invention may contain other additives, if necessary. As other additives, flowability improvers, cleaning improvers or offset inhibitors may also be added. The fluidity improver serves to impart high fluidity to the toner, facilitate continuous supply of the toner, and form a visible image of good quality. Hydrophobic silica powder is most suitable as the fluidity improver.
Such hydrophobic silica powder is made by combining fine powder of silicon dioxide whose surface silicon atoms are silanol groups, such as octyltrichlorosilane, decyltrichlorosilane, nonyltrichlorosilane, 4-
Isopropylphenyltrichlorosilane, 4-
tert-butylphenyltrichlorosilane, dimethyldichlorosilane, dibenzimadichlorosilane,
Dihexyldichlorosilane, dioctyldichlorosilane, dinonyldichlorosilane, didecyldichlorosilane, didodecyldichlorosilane, 4-tert
-Butylphenyloctyldichlorosilane, dioctyldichlorosilane, didecenyldichlorosilane, dinonenyldichlorosilane, di-2-ethylhexyldichlorosilane, di-3,3-dimethylpentyldichlorosilane, trimethylchlor By reacting with compounds such as silane, trihexylchlorosilane, trioctylchlorosilane, tridecylchlorosilane, dioctylchlorosilane, octyldimethylchlorosilane, and 4-isopropylphenyldiethylchlorosilane, the surface silicon of silicon dioxide powder can be removed. A hydrophobic group is bonded to an atom via an oxygen atom. These hydrophobic silica powders have an average particle size of
It is preferably within the range of 1 mμ to 100 μm, especially
It is preferably between 2 mμ and 50 μm. If it is less than 1 mμ, the powder tends to scatter and is difficult to handle, and if it exceeds 100 μm, it tends to damage the photoreceptor. Such hydrophobic silica powder is
R972, Silica D-17, R812, RA200H, RX-
It is commercially available under trade names such as C (manufactured by Nippon Aerosil Co., Ltd.) and Taranox 500 (manufactured by Tulco). Although a toner may be manufactured by blending the hydrophobic silica powder as described above with other toner materials,
In particular, it is preferable to once manufacture a toner using toner materials excluding hydrophobic silica powder, and then add hydrophobic silica powder. When hydrophobic silica powder is added, the hydrophobic silica powder is preferably added in an amount of 0.01 to 15% by weight based on the toner powder not containing the hydrophobic silica powder. Particularly preferred is an addition amount of 0.1 to 10% by weight.
If the amount added is less than 0.01% by weight, the effect of improving fluidity will not appear, and even if it is added in excess of 15% by weight, the effect will not increase accordingly. The cleaning performance improver prevents the so-called filming phenomenon in which a portion of the toner components adheres to the surface of the photoreceptor or carrier, and serves to form a clear visible image without fogging even during long-term continuous use. Cleanability improvers include metal salts of saturated or unsaturated fatty acids, such as maleic acid, stearic acid, oleic acid, palmitic acid, caproic acid, linoleic acid, ricinoleic acid or ricinoleic acid with zinc, magnesium, calcium, cadmium, Mention may be made of salts with lead, iron, nickel, cobalt, copper or aluminum, with zinc stearate, calcium stearate or magnesium stearate being particularly preferred. When a cleaning performance improver is used, it is particularly preferable that the cleaning performance improvement agent is added in the same manner as the hydrophobic silica powder described above. The fatty acid metal salt is 0.01 to 25% by weight, especially based on the toner powder not containing the fatty acid metal salt and the hydrophobic silica powder.
It is preferable to add 0.1 to 10% by weight. 0.01% by weight
If it is less than that, the effect of improving cleaning performance will not be exhibited. However, adding more than 25% by weight does not increase the effect. It is generally advantageous to fix a toner image on an image support by a heat fixing method, and this heat fixing method includes a non-contact heat fixing method such as oven fixing, and a contact heating method such as hot roll fixing. However, the contact heat fixing method has high thermal efficiency and allows equipment to be made smaller.
It has advantages such as low power consumption. However, in the contact heat fixing method, when the image support carrying the toner image passes through the heat roll, part of the toner image is transferred to the heat roll, and after the heat roll has made one revolution, the transferred toner image is transferred to the image support. There is a serious problem of re-metastasis and contamination. The anti-offset agent plays a role in forming high-quality images without causing offset even in the hot roll fixing system. Offset inhibitors include ethylene, propylene, butene, pentene, hexene, heptene,
Polymers of olefin monomers such as octene, nonene, decene, 3-methyl-1-butene, 3-methyl-2-pentene, 3-propyl-5-methyl-2-hexene, or the above-mentioned olefin monomers and acrylic acid. , copolymers with methacrylic acid, vinyl acetate, etc., lower alcohol esters of fatty acids such as butyl stearate, propyl stearate, casta wax (manufactured by Ito Oil Co., Ltd.), diamond wax (manufactured by Shin Nippon Chemical Co., Ltd.) Polyhydric alcohol esters of fatty acids such as palm acetate (NOF)
Co., Ltd.), Hoechstwax E, Hoechstwax-OP (manufactured by Hoechst Aktiengesellshaft),
Higher alcohol esters of fatty acids such as carnauba wax, Bisamide Blast Flow (manufactured by Nitto Kagaku Kogyo Co., Ltd.), Amide 6L, 7S and 6H (manufactured by Kawaken Fine Chemical Co., Ltd.), Hoechst Wax C (Hoechst・Alkylene bis fatty acid amide compounds (manufactured by Aktiengesellschaft), zinc stearate,
Calcium stearate, magnesium stearate, barium stearate, copper stearate,
Fatty acid metal salts such as aluminum stearate, zinc oleate, magnesium oleate, zinc caprylate, magnesium caprylate, zinc linoleate, calcium linoleate, Nitupol NBR,
The weight average molecular weight of 2057S, 2007J, BR1220, etc. is 5.
There are over 10,000 diene resins, hydroxyl group-containing vinyl resins, carboxyl group-containing vinyl resins, etc. When an anti-offset agent is added, it is particularly preferred that the anti-offset agent be blended with other toner materials to produce the toner. The anti-offset agent is preferably added to the toner in an amount of 0.1 to 50% by weight, especially 1 to 30% by weight. If it is less than 0.1% by weight, the effect of preventing offset will not appear, and if it is added in excess of 50% by weight, the effect will not increase. In the present invention, the above fluidity improver, cleaning performance improver and offset inhibitor may be added alone or in combination. The above-mentioned materials can be mixed, for example, by the following method to produce a toner for developing electrostatic images. The weighed materials are premixed using a W cone, V blender, Henschel mixer, etc., and then kneaded using a pressure kneader, Banbury mixer, hot roll, extruder, etc. at a temperature at which the resin melts. After cooling, it is coarsely ground using a feather mill, pin mill, pulverizer, hammer mill, etc. Next, the particles are sieved using an Akiyukatsu or Alpine classifier to adjust the particle size to preferably 5 to 30 μm. The toner of the present invention can be applied to various known developing methods. Further, the toner of the present invention can be used by various fixing methods,
For example, it can be used in so-called oil-less and oil-coated heat roll methods, flashing methods, oven methods, pressure fixing methods, and the like. Furthermore, the toner of the present invention can be used in various cleaning methods, such as the so-called fur brush method and blade method. (Examples) The present invention will be explained below using examples. Examples 1 to 6 and Comparative Examples 1 to 2 (1) Synthesis of copolymer In a reaction vessel, 200 parts by weight of water and a suspending agent [polyvinyl alcohol, Denka Poval W-24, trade name of Denki Kagaku Kogyo Co., Ltd.] 0.3 Prepare 90 parts by weight and dissolve uniformly.
The temperature was raised to ℃, and while stirring, a solution of 2% by weight of benzoyl peroxide dissolved in a vinyl monomer having the composition shown in Table 1 was added.
The solution was added dropwise over a period of time to perform suspension polymerization, and then kept at 90°C for 10 hours while stirring. After cooling and filtering, the mixture was thoroughly dried to obtain a copolymer. Table 1 shows the glass transition temperature of this copolymer. (2) Manufacture of toner The materials shown in Table 2 were premixed all at once using a Henschel mixer, and then melted and kneaded at 90°C using a uniaxial kneader. The cooled kneaded product was then finely pulverized using a pin mill and a jet mill, and classified using a vibrating sieve to obtain a toner having an average particle size of 10 to 15 μm. (3) Manufacture and testing of developer Toner 3 parts by weight and apparent density 3.5 to 4.5 g/cm ³ , 44
A developer was obtained by mixing with 97 parts by weight of iron oxide powder containing 90% by weight or more of particle sizes of ~177 μm. OPC rotates at a circumferential speed of approximately 20cm/sec
(Organic Photoconductor) After uniformly negatively charging the drum with a corona voltage of -6KV,
Information was written using a Ne laser, and reversal development was performed using the developer using a magnetic brush method. Then, it was fixed using a pressure roll fixing machine. Table 3 shows the results of measuring the optical reflection density of the printed portion and fogged portion of the obtained fixed image using a microphotometer MPM type (manufactured by Union Chemical Co., Ltd.). The print quality after printing 200,000 sheets was judged by changes in print density, increase in fog, etc. Print defects caused by soft vinyl chloride can be resolved by sandwiching the printed material between sheets of soft vinyl chloride polymer containing 30% by weight of dioctyl phthalate at a temperature of 40°C and under a load.
The test was carried out under the conditions of 100 gf/cm ² and a test time of 300 hours. The toner's caking resistance is at a temperature of 50℃ and humidity of 60%.
The RH test was conducted under conditions of 18 hours. As is clear from Table 3, when printing with the developer using the toners of Examples 1 to 6, prints with good fixing strength (as judged from print density and fog density) were obtained, and 200,000 sheets were printed. No deterioration in print quality was observed even in this case. Furthermore, no printing defects were caused by the soft vinyl chloride polymer, and the caking resistance was also good. With the toner of Comparative Example 1, fog occurred on the entire surface and could not be evaluated, and with the toner of Comparative Example 2, the print quality deteriorated as printing continued and the caking resistance was poor. Print defects occurred.

[Table] Γ Values in the table (excluding Tg) indicate parts by weight. Γ Glass transition temperature measurement conditions Thermomechanical analysis method Pernation mode Load 70gf Temperature increase rate 10℃/min

【table】

【table】

[Table] ☆ Density is optical reflection density.
*Print density drops to 1.0 after 20,000 sheets, and fog density drops to 0.
Increased to 15. At 100,000 sheets, the print density decreased to 1.4 and the fog density increased to 0.3.
(Effects of the Invention) The negatively chargeable toner for developing electrostatic images according to the present invention is a toner that can control charge without using a charge control agent, which has been a problem in the past, and does not use a charge control agent. This makes it possible to eliminate fogging, framing, and changes in print density. Furthermore, the toner of the present invention does not adhere to soft vinyl chloride polymers.

Claims (1)

[Scope of Claims] 1. A negatively chargeable toner for developing electrostatic images, which contains a polymer having a vinyl monomer represented by any of the following structural formulas I to V as a binder resin. (However, in the above formula, R ₁ , X ₁ and X ₂ are each independently hydrogen or a methyl group, R ₂ is an alkylene group having 1 to 6 carbon atoms, R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀ are each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, halogen or [Formula], where R ₁₁ , R ₁₂ and R ₁₃ are each independently Hydrogen or an alkyl group having 1 to 3 carbon atoms, and each of structural formulas I to V has at least one [formula])