JP6474040B2 - Magnetic carrier for electrophotography and manufacturing method thereof - Google Patents
Magnetic carrier for electrophotography and manufacturing method thereof Download PDFInfo
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- 230000005291 magnetic effect Effects 0.000 title claims description 57
- 238000004519 manufacturing process Methods 0.000 title claims description 9
- 239000002245 particle Substances 0.000 claims description 227
- 150000002506 iron compounds Chemical class 0.000 claims description 154
- 239000011246 composite particle Substances 0.000 claims description 83
- 230000005294 ferromagnetic effect Effects 0.000 claims description 57
- 239000005011 phenolic resin Substances 0.000 claims description 17
- 239000002131 composite material Substances 0.000 claims description 15
- 150000002989 phenols Chemical class 0.000 claims description 14
- 239000002344 surface layer Substances 0.000 claims description 14
- 150000001299 aldehydes Chemical class 0.000 claims description 9
- 239000011230 binding agent Substances 0.000 claims description 9
- 239000012736 aqueous medium Substances 0.000 claims description 8
- 239000003054 catalyst Substances 0.000 claims description 7
- 239000007771 core particle Substances 0.000 claims description 7
- 238000002156 mixing Methods 0.000 claims description 7
- 238000003756 stirring Methods 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 5
- 239000006249 magnetic particle Substances 0.000 claims description 3
- 230000015572 biosynthetic process Effects 0.000 claims description 2
- 238000006073 displacement reaction Methods 0.000 claims 1
- 239000011572 manganese Substances 0.000 description 35
- 238000006243 chemical reaction Methods 0.000 description 27
- 230000005415 magnetization Effects 0.000 description 22
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 20
- 239000007864 aqueous solution Substances 0.000 description 14
- 239000011019 hematite Substances 0.000 description 12
- 229910052595 hematite Inorganic materials 0.000 description 12
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 description 12
- 239000011162 core material Substances 0.000 description 11
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 10
- 239000006087 Silane Coupling Agent Substances 0.000 description 9
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 9
- 239000000243 solution Substances 0.000 description 9
- 230000005484 gravity Effects 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 101100533725 Mus musculus Smr3a gene Proteins 0.000 description 7
- 101100149716 Rattus norvegicus Vcsa1 gene Proteins 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 239000011347 resin Substances 0.000 description 7
- 229920005989 resin Polymers 0.000 description 7
- 239000000969 carrier Substances 0.000 description 6
- 229910052742 iron Inorganic materials 0.000 description 6
- 230000006866 deterioration Effects 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical compound OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 4
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 4
- 229910052748 manganese Inorganic materials 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 238000001878 scanning electron micrograph Methods 0.000 description 4
- 239000004094 surface-active agent Substances 0.000 description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 3
- 125000003277 amino group Chemical group 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- 125000003700 epoxy group Chemical group 0.000 description 3
- 239000011790 ferrous sulphate Substances 0.000 description 3
- 235000003891 ferrous sulphate Nutrition 0.000 description 3
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 3
- 229940099596 manganese sulfate Drugs 0.000 description 3
- 239000011702 manganese sulphate Substances 0.000 description 3
- 235000007079 manganese sulphate Nutrition 0.000 description 3
- SQQMAOCOWKFBNP-UHFFFAOYSA-L manganese(II) sulfate Chemical compound [Mn+2].[O-]S([O-])(=O)=O SQQMAOCOWKFBNP-UHFFFAOYSA-L 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- BPSIOYPQMFLKFR-UHFFFAOYSA-N trimethoxy-[3-(oxiran-2-ylmethoxy)propyl]silane Chemical compound CO[Si](OC)(OC)CCCOCC1CO1 BPSIOYPQMFLKFR-UHFFFAOYSA-N 0.000 description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 2
- ROSDSFDQCJNGOL-UHFFFAOYSA-N Dimethylamine Chemical compound CNC ROSDSFDQCJNGOL-UHFFFAOYSA-N 0.000 description 2
- 239000007983 Tris buffer Substances 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 235000011114 ammonium hydroxide Nutrition 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical compound C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 description 2
- 230000001143 conditioned effect Effects 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000007822 coupling agent Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- -1 etc. Substances 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- HYBBIBNJHNGZAN-UHFFFAOYSA-N furfural Chemical compound O=CC1=CC=CO1 HYBBIBNJHNGZAN-UHFFFAOYSA-N 0.000 description 2
- 229910052598 goethite Inorganic materials 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- VKYKSIONXSXAKP-UHFFFAOYSA-N hexamethylenetetramine Chemical compound C1N(C2)CN3CN1CN2C3 VKYKSIONXSXAKP-UHFFFAOYSA-N 0.000 description 2
- 125000001165 hydrophobic group Chemical group 0.000 description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 2
- AEIXRCIKZIZYPM-UHFFFAOYSA-M hydroxy(oxo)iron Chemical compound [O][Fe]O AEIXRCIKZIZYPM-UHFFFAOYSA-M 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- RLSSMJSEOOYNOY-UHFFFAOYSA-N m-cresol Chemical compound CC1=CC=CC(O)=C1 RLSSMJSEOOYNOY-UHFFFAOYSA-N 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 108091008695 photoreceptors Proteins 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- GHMLBKRAJCXXBS-UHFFFAOYSA-N resorcinol Chemical compound OC1=CC=CC(O)=C1 GHMLBKRAJCXXBS-UHFFFAOYSA-N 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L sodium carbonate Substances [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 230000003746 surface roughness Effects 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 238000005303 weighing Methods 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- WYTZZXDRDKSJID-UHFFFAOYSA-N (3-aminopropyl)triethoxysilane Chemical compound CCO[Si](OCC)(OCC)CCCN WYTZZXDRDKSJID-UHFFFAOYSA-N 0.000 description 1
- IEKHISJGRIEHRE-UHFFFAOYSA-N 16-methylheptadecanoic acid;propan-2-ol;titanium Chemical compound [Ti].CC(C)O.CC(C)CCCCCCCCCCCCCCC(O)=O.CC(C)CCCCCCCCCCCCCCC(O)=O.CC(C)CCCCCCCCCCCCCCC(O)=O IEKHISJGRIEHRE-UHFFFAOYSA-N 0.000 description 1
- KKOHCQAVIJDYAF-UHFFFAOYSA-N 2-dodecylbenzenesulfonic acid;propan-2-ol;titanium Chemical compound [Ti].CC(C)O.CCCCCCCCCCCCC1=CC=CC=C1S(O)(=O)=O.CCCCCCCCCCCCC1=CC=CC=C1S(O)(=O)=O.CCCCCCCCCCCCC1=CC=CC=C1S(O)(=O)=O KKOHCQAVIJDYAF-UHFFFAOYSA-N 0.000 description 1
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 1
- LCHYEKKJCUJAKN-UHFFFAOYSA-N 2-propylphenol Chemical compound CCCC1=CC=CC=C1O LCHYEKKJCUJAKN-UHFFFAOYSA-N 0.000 description 1
- QHPQWRBYOIRBIT-UHFFFAOYSA-N 4-tert-butylphenol Chemical compound CC(C)(C)C1=CC=C(O)C=C1 QHPQWRBYOIRBIT-UHFFFAOYSA-N 0.000 description 1
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical group [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 1
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 229910021380 Manganese Chloride Inorganic materials 0.000 description 1
- GLFNIEUTAYBVOC-UHFFFAOYSA-L Manganese chloride Chemical compound Cl[Mn]Cl GLFNIEUTAYBVOC-UHFFFAOYSA-L 0.000 description 1
- 229920002873 Polyethylenimine Polymers 0.000 description 1
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 238000003917 TEM image Methods 0.000 description 1
- UMHKOAYRTRADAT-UHFFFAOYSA-N [hydroxy(octoxy)phosphoryl] octyl hydrogen phosphate Chemical compound CCCCCCCCOP(O)(=O)OP(O)(=O)OCCCCCCCC UMHKOAYRTRADAT-UHFFFAOYSA-N 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 150000003973 alkyl amines Chemical class 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 150000001555 benzenes Chemical class 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 125000001309 chloro group Chemical group Cl* 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- OTARVPUIYXHRRB-UHFFFAOYSA-N diethoxy-methyl-[3-(oxiran-2-ylmethoxy)propyl]silane Chemical compound CCO[Si](C)(OCC)CCCOCC1CO1 OTARVPUIYXHRRB-UHFFFAOYSA-N 0.000 description 1
- PKTOVQRKCNPVKY-UHFFFAOYSA-N dimethoxy(methyl)silicon Chemical compound CO[Si](C)OC PKTOVQRKCNPVKY-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- FWDBOZPQNFPOLF-UHFFFAOYSA-N ethenyl(triethoxy)silane Chemical compound CCO[Si](OCC)(OCC)C=C FWDBOZPQNFPOLF-UHFFFAOYSA-N 0.000 description 1
- 230000005307 ferromagnetism Effects 0.000 description 1
- 229960002089 ferrous chloride Drugs 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000004312 hexamethylene tetramine Substances 0.000 description 1
- 235000010299 hexamethylene tetramine Nutrition 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- YDZQQRWRVYGNER-UHFFFAOYSA-N iron;titanium;trihydrate Chemical compound O.O.O.[Ti].[Fe] YDZQQRWRVYGNER-UHFFFAOYSA-N 0.000 description 1
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- 239000011565 manganese chloride Substances 0.000 description 1
- 235000002867 manganese chloride Nutrition 0.000 description 1
- 229940099607 manganese chloride Drugs 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- KBJFYLLAMSZSOG-UHFFFAOYSA-N n-(3-trimethoxysilylpropyl)aniline Chemical compound CO[Si](OC)(OC)CCCNC1=CC=CC=C1 KBJFYLLAMSZSOG-UHFFFAOYSA-N 0.000 description 1
- 230000033116 oxidation-reduction process Effects 0.000 description 1
- AJCDFVKYMIUXCR-UHFFFAOYSA-N oxobarium;oxo(oxoferriooxy)iron Chemical compound [Ba]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O AJCDFVKYMIUXCR-UHFFFAOYSA-N 0.000 description 1
- 229920001568 phenolic resin Polymers 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 229920003987 resole Polymers 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 239000011669 selenium Substances 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 239000006228 supernatant Substances 0.000 description 1
- GQIUQDDJKHLHTB-UHFFFAOYSA-N trichloro(ethenyl)silane Chemical compound Cl[Si](Cl)(Cl)C=C GQIUQDDJKHLHTB-UHFFFAOYSA-N 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 239000005050 vinyl trichlorosilane Substances 0.000 description 1
Description
本発明は、磁性体粒子を樹脂中に分散させた球状複合体粒子であって、適度な飽和磁化値を備え、粒子表面の電気抵抗が制御され、また、現像性が高く高寿命な電子写真用磁性キャリア及びその製造方法に関するものである。 The present invention relates to spherical composite particles in which magnetic particles are dispersed in a resin, having an appropriate saturation magnetization value, controlling the electric resistance of the particle surface, and having high developability and long life. The present invention relates to a magnetic carrier for use and a manufacturing method thereof.
周知の通り、電子写真法においては、セレン、ＯＰＣ（有機半導体）、α−Ｓｉ等の光導電性物質を感光体として用い、種々の手段により静電気的潜像を形成し、この潜像に磁気ブラシ現像法等を用いて、潜像の極性と逆に帯電させたトナーを静電気力により付着させ、顕像化する方式が一般に採用されている。 As is well known, in electrophotography, a photoconductive substance such as selenium, OPC (organic semiconductor), or α-Si is used as a photoconductor, and an electrostatic latent image is formed by various means. In general, a method is used in which a toner charged opposite to the polarity of the latent image is attached by electrostatic force and visualized by using a brush developing method or the like.
この現像工程においては、トナーとキャリアからなる二成分系の現像剤が使用され、キャリアと呼ばれる担体粒子が摩擦帯電により適量の正又は負の電気量をトナーに付与し、且つ、磁気力を利用し磁石を内蔵する現像スリーブを介して、潜像を形成した感光体表面付近の現像領域にトナーを搬送する。 In this development process, a two-component developer composed of a toner and a carrier is used, and carrier particles called carriers impart an appropriate amount of positive or negative electricity to the toner by frictional charging, and use magnetic force. Then, the toner is conveyed to a developing area near the surface of the photoreceptor on which the latent image is formed via a developing sleeve having a built-in magnet.
近年、この電子写真法は複写機あるいはプリンターに広く多用化されており、細線や小文字、写真あるいはカラー原稿等様々な文書に対応できることが要求されている。さらに高画質化や高品位化、高速化及び連続化等についても、合わせて要求されており、今後も益々これらの要求は大きくなるものと思われる。 In recent years, this electrophotographic method has been widely used in copying machines or printers, and is required to be compatible with various documents such as fine lines, lowercase letters, photographs, and color originals. Furthermore, there is a demand for higher image quality, higher quality, higher speed, and continuity, and these demands are expected to increase in the future.
このキャリアとして、磁性体粒子を樹脂中に分散させた複合体粒子であるバインダ型キャリアが広く用いられている。バインダ型キャリアは、２．５ｇ／ｃｍ３程度以下と嵩密度が小さいものであると共に、粒子に形状的な歪みが少なく、粒子強度が高い傾向にある球状にすることが容易であり、その粒子サイズも広範囲に制御できることから、現像スリーブ又はスリーブ内の磁石の回転数が大きい高速複写機や汎用コンピュータの高速レーザビームプリンタ等に最適である。 As this carrier, a binder type carrier which is a composite particle in which magnetic particles are dispersed in a resin is widely used. The binder-type carrier has a low bulk density of about 2.5 g / cm 3 or less, and can be easily formed into a spherical shape with little shape distortion and a high particle strength. Since the size can be controlled over a wide range, it is optimal for a high-speed copying machine having a large number of rotations of a developing sleeve or a magnet in the sleeve, a high-speed laser beam printer of a general-purpose computer, or the like.
キャリアは適当な飽和磁化値を有することが求められる。磁化値を適度に高くすることでスリーブ上のマグネットブラシのいわゆる『穂』を形成しているキャリアが磁気力の低いことに起因して『穂』から離れて感光体に飛んでいき、感光体上に付着するいわゆるキャリア付着が生じ難くなる。また、あまりに磁化値が大きいと画像荒れなど、解像度の低下が生じる。 The carrier is required to have an appropriate saturation magnetization value. By appropriately increasing the magnetization value, the carrier forming the so-called “bump” of the magnetic brush on the sleeve flies away from the “brow” due to the low magnetic force and flies to the photoconductor. So-called carrier adhesion that adheres to the top is less likely to occur. Also, if the magnetization value is too large, the resolution will be degraded, such as image roughness.
また、キャリアには、高い電気抵抗を有することが求められている。すなわち、電気抵抗が低い場合、スリーブからの電荷注入によりキャリアが感光体の画像部へ付着したり、潜像電荷がキャリアを介して逃げ、潜像の乱れや画像の欠損等を生じたりする等の問題がある。 Further, the carrier is required to have a high electric resistance. That is, when the electrical resistance is low, carriers are attached to the image area of the photoreceptor due to charge injection from the sleeve, or latent image charges escape through the carriers, resulting in disturbance of the latent image, image loss, etc. There is a problem.
これらの問題を解決するために、キャリア表面を構成する粒子に非磁性鉄化合物粒子を用いて、キャリアの電気抵抗を高くすることが提案されている。（特許文献１、２） In order to solve these problems, it has been proposed to increase the electrical resistance of the carrier by using non-magnetic iron compound particles as the particles constituting the carrier surface. (Patent Documents 1 and 2)
ところが、この非磁性鉄化合物粒子は抵抗が非常に高いため、結果としてキャリア自体の電気抵抗値が高くなりすぎる。そのため、キャリア電荷のリークが生じにくくなり、さらにトナーの帯電量も高くなり、その結果得られる画像はエッジの効いた画になるが、一方、大面積の画像面では中央部の画像濃度が非常に薄くなるといった問題が生じる。 However, since the nonmagnetic iron compound particles have a very high resistance, the electric resistance value of the carrier itself becomes too high as a result. As a result, leakage of carrier charges is less likely to occur, and the toner charge amount is also increased. As a result, the resulting image is an edged image, but on the large image area, the image density at the center is very high. The problem of thinning occurs.
これらのことから、高度に電気抵抗が制御された非磁性鉄化合物粒子および該非磁性鉄化合物粒子を含むキャリアが要求されている。 For these reasons, nonmagnetic iron compound particles with highly controlled electrical resistance and carriers containing the nonmagnetic iron compound particles are required.
また、キャリアには、その表面に適当な凸部を持つことが求められている。すなわち、表面に適当な凸部を持つことでキャリア同士もしくはトナーとの接触面積が小さくなり、キャリアへのスペントやトナーの劣化が抑制され現像剤の寿命が延びる。さらに、バインダ型キャリアは流動性が高すぎるためトナーと混ざりにくいが、表面に適当な凸部を持つことで流動性が下がるためトナーとの混合性が高まり、トナーに安定した帯電量を付与することができるとされている。 Further, the carrier is required to have an appropriate convex portion on the surface thereof. That is, by having an appropriate convex portion on the surface, the contact area between the carriers or the toner is reduced, the spent on the carrier and the deterioration of the toner are suppressed, and the life of the developer is extended. Further, the binder type carrier is too fluid to be mixed with the toner, but having a suitable convex portion on the surface lowers the fluidity, so that the mixing with the toner is enhanced and a stable charge amount is imparted to the toner. It is supposed to be possible.
適当な飽和磁化値を有するとともに、高度に電気抵抗が制御され、さらに適当な表面凸部を持つ球状複合体粒子は、現在最も要求されているところであるが、このような磁性キャリアは未だ提供されていない。 Spherical composite particles having an appropriate saturation magnetization value, highly controlled electrical resistance, and having an appropriate surface convexity are currently in most demand, but such magnetic carriers are still provided. Not.
すなわち、特許文献１に記載の球形を呈した強磁性粒子含有フェノール樹脂複合体粒子は、非磁性鉄化合物粒子が芯材表面に存在することで電気抵抗値を高くすることができるが、この非磁性鉄化合物粒子は電気抵抗が制御されていないため、キャリアとしての抵抗が高くなりすぎて画像濃度が薄くなるという問題が生じる。 That is, the ferromagnetic particle-containing phenol resin composite particles having a spherical shape described in Patent Document 1 can have a high electrical resistance value due to the presence of the nonmagnetic iron compound particles on the surface of the core material. Since the magnetic iron compound particles are not controlled in electric resistance, there arises a problem that the resistance as a carrier becomes too high and the image density becomes thin.
特許文献２に記載のキャリアは、強磁性鉄化合物粒子の平均粒径ｒａと非磁性鉄化合物粒子の平均粒径ｒｂの比、ｒｂ／ｒａが１．０を超え、キャリアとしての抵抗を高くするものであるが、この非磁性鉄化合物粒子は電気抵抗が制御されていないため、キャリアとしての抵抗が高くなりすぎて画像濃度が薄くなるという問題が生じる。 Carrier according to Patent Document 2, the ratio of the average particle size r b of the average particle diameter r a nonmagnetic iron compound particles of the ferromagnetic iron compound particles greater than r b / r a is 1.0, as a carrier Although the resistance is increased, the non-magnetic iron compound particles are not controlled in electrical resistance, so that the resistance as a carrier becomes too high and the image density becomes low.
特許文献３に記載のキャリアは、強磁性鉄化合物粒子の平均粒径ｒａと非磁性鉄化合物粒子の平均粒径ｒｂの比、ｒａ／ｒｂを１．２以上とし、キャリアとしての抵抗を比較的低くするものであるが、キャリア表面に存在する磁性および非磁性鉄化合物粒子の粒径がそれぞれ０．２４μｍ以下と小さく適度な表面凸部が形成されないため現像剤の高寿命化やトナーへの安定した帯電付与性が望めない。 The carrier according to Patent Document 3, the average particle size r b of the average particle diameter r a nonmagnetic iron compound particles of the ferromagnetic iron compound particles ratio, and a r a / r b 1.2 or more, as a carrier Although the resistance is relatively low, the particle size of the magnetic and non-magnetic iron compound particles existing on the carrier surface is as small as 0.24 μm or less, respectively, and an appropriate surface convex portion is not formed. A stable charge imparting property to the toner cannot be expected.
そこで、本発明は、適当な飽和磁化値を有すると共に、高度に電気抵抗が制御され、さらに適当な表面凸部をもつことを特徴とする電子写真用磁性キャリアを提供することを技術的課題とする。 Therefore, the present invention has a technical problem to provide a magnetic carrier for electrophotography having an appropriate saturation magnetization value, a highly controlled electric resistance, and further having an appropriate surface protrusion. To do.
前記技術的課題は、次のとおりの本発明によって達成できる。 The technical problem can be achieved by the present invention as follows.
すなわち、本発明は強磁性鉄化合物粒子と非磁性鉄化合物粒子とをフェノール樹脂をバインダとして結合してなる平均粒径１０〜１００μｍの球状複合体粒子であって、強磁性鉄化合物粒子を主として含有する核部と非磁性鉄化合物粒子を主として含有する表層部とからなる球状複合体粒子からなる電子写真用磁性キャリアであって、当該球状複合体粒子に含まれる強磁性鉄化合物粒子と非磁性鉄化合物粒子との総量が８０〜９９ｗｔ％であり、該非磁性鉄化合物粒子中のＭｎ含有量が０．３〜２５ｗｔ％であり、且つ、強磁性鉄化合物粒子の平均粒径ｒａと非磁性鉄化合物粒子の平均粒径ｒｂとの比ｒｂ／ｒａが１．０を越えることを特徴とする電子写真用磁性キャリアである。 That is, the present invention is a spherical composite particle having an average particle size of 10 to 100 μm formed by binding a ferromagnetic iron compound particle and a nonmagnetic iron compound particle using a phenol resin as a binder, and mainly contains the ferromagnetic iron compound particle. A magnetic carrier for electrophotography comprising spherical composite particles composed of a core portion to be formed and a surface layer portion mainly containing nonmagnetic iron compound particles , wherein the ferromagnetic iron compound particles and nonmagnetic iron contained in the spherical composite particles the total amount of the compound particles is 80~99wt%, Mn content of non-magnetic iron compound particles is 0.3～25Wt%, and an average particle size r a nonmagnetic iron ferromagnetic iron compound particles the ratio r b / r a between the average particle size r b of the compound particles is an electrophotographic magnetic carrier, characterized in that exceeding 1.0.
本発明における球状複合体粒子は、強磁性鉄化合物粒子と非磁性鉄化合物粒子とをフェノール樹脂をバインダとして結合してなり、該非磁性鉄化合物粒子がＭｎを含有するため、適当な飽和磁化値、殊に２０〜１００ｅｍｕ／ｇ程度の飽和磁化値を有すると共に、電気抵抗値が１０１０〜１０１１Ωｃｍ程度に高度に制御されたものであり、高画質化や高品位化が実現できる電子写真用磁性キャリアとして好適である。 The spherical composite particles in the present invention are formed by binding ferromagnetic iron compound particles and nonmagnetic iron compound particles using a phenol resin as a binder, and the nonmagnetic iron compound particles contain Mn. In particular, it has a saturation magnetization value of about 20 to 100 emu / g and is highly controlled to an electric resistance value of about 10 10 to 10 11 Ωcm, and can achieve high image quality and high quality. Suitable as a magnetic carrier.
また、本発明における球状複合体粒子は、強磁性鉄化合物粒子の粒径と非磁性鉄化合物粒子の粒径との比を制御することにより、Ｍｎによって電気抵抗が制御された非磁性鉄化合物粒子を表層部に有し、粒子表面に適度な凸部を有するものであり、キャリアとして使用した場合には、トナーとの混合性が良く、その結果、トナーの帯電速度を速めることができ、また、トナーにダメージを与えることなく、スペント化も抑制することができ、さらに、過度のトナー帯電量が抑制でき、長期間キャリアを使用していても安定したトナー帯電量が保持できるため、高画質化や高寿命化、高速化及び連続化が実現できる電子写真用磁性キャリアとして好適である。 Further, the spherical composite particles in the present invention are nonmagnetic iron compound particles whose electric resistance is controlled by Mn by controlling the ratio of the particle size of the ferromagnetic iron compound particles and the particle size of the nonmagnetic iron compound particles. In the surface layer part, and has an appropriate convex part on the particle surface, and when used as a carrier, the mixing with the toner is good, and as a result, the charging speed of the toner can be increased, and The toner can be suppressed without damaging the toner, and the toner charge can be suppressed excessively, and the toner charge can be kept stable even when the carrier is used for a long time. It is suitable as a magnetic carrier for electrophotography that can realize a long life, a long life, a high speed and a continuous operation.
以下、本発明を詳細に説明する。まず、本発明に係る電子写真用磁性キャリアについて述べる。 Hereinafter, the present invention will be described in detail. First, the magnetic carrier for electrophotography according to the present invention will be described.
本発明に係る電子写真用磁性キャリアは、強磁性鉄化合物粒子と非磁性鉄化合物粒子とをフェノール樹脂をバインダとして結合してなる球状複合体粒子である。 The magnetic carrier for electrophotography according to the present invention is a spherical composite particle formed by binding ferromagnetic iron compound particles and nonmagnetic iron compound particles using a phenol resin as a binder.
本発明における球状複合体粒子は、平均粒径が１０〜１００μｍである。平均粒径が１０μｍ未満の粒子は二次凝集しやすく、１００μｍを越えるものは機械的強度が弱く、さらに鮮明な画像を得ることができなくなる。特に、高画質を求める場合には平均粒径が２０〜８０μｍの範囲が好ましく、さらに好ましくは３０〜７０μｍの範囲である。 The spherical composite particles in the present invention have an average particle size of 10 to 100 μm. Particles having an average particle size of less than 10 μm tend to agglomerate, and particles having an average particle size exceeding 100 μm have a low mechanical strength, making it impossible to obtain a clearer image. In particular, when high image quality is desired, the average particle size is preferably in the range of 20 to 80 μm, more preferably in the range of 30 to 70 μm.
本発明における球状複合体粒子は、強磁性鉄化合物粒子と非磁性鉄化合物粒子とを含み、球状複合体粒子に含まれる強磁性鉄化合物粒子と非磁性鉄化合物粒子との総量が８０〜９９ｗｔ％である。強磁性鉄化合物粒子と非磁性鉄化合物粒子との総量が８０ｗｔ％未満では十分に高い飽和磁化値が得られず、９９ｗｔ％を越えるとバインダが不足して十分な強度を有する複合体粒子が得られない。 The spherical composite particles in the present invention include ferromagnetic iron compound particles and nonmagnetic iron compound particles, and the total amount of ferromagnetic iron compound particles and nonmagnetic iron compound particles contained in the spherical composite particles is 80 to 99 wt%. It is. If the total amount of the ferromagnetic iron compound particles and the nonmagnetic iron compound particles is less than 80 wt%, a sufficiently high saturation magnetization value cannot be obtained, and if it exceeds 99 wt%, a binder particle is insufficient and composite particles having sufficient strength are obtained. I can't.
さらに、本発明における球状複合体粒子に含まれる非磁性鉄化合物粒子の含有量は強磁性鉄化合物粒子と非磁性鉄化合物粒子との総量に対し、好ましくは１〜５０ｗｔ％の範囲であり、より好ましくは１０〜４０ｗｔ％の範囲である。非磁性鉄化合物粒子の含有量が１ｗｔ％未満の場合、非磁性鉄化合物粒子が不足して適度に高い電気抵抗が得られず、また、球状複合体粒子の表面に充分に分散されないため、適当な表面凸部が得られない。さらに、強磁性鉄化合物の割合が多くなることで磁化値が大きくなりすぎるため画像が荒くなってしまう。非磁性鉄化合物粒子の含有量が５０ｗｔ％を越える場合、十分な磁化値が得られない。 Furthermore, the content of the nonmagnetic iron compound particles contained in the spherical composite particles in the present invention is preferably in the range of 1 to 50 wt%, based on the total amount of the ferromagnetic iron compound particles and the nonmagnetic iron compound particles, and more Preferably it is the range of 10-40 wt%. When the content of the non-magnetic iron compound particles is less than 1 wt%, the non-magnetic iron compound particles are insufficient and an adequately high electric resistance cannot be obtained, and the particles are not sufficiently dispersed on the surface of the spherical composite particles. A surface convex part cannot be obtained. Further, since the magnetization value becomes too large due to an increase in the proportion of the ferromagnetic iron compound, the image becomes rough. When the content of nonmagnetic iron compound particles exceeds 50 wt%, a sufficient magnetization value cannot be obtained.
また、本発明における球状複合体粒子に含まれる非磁性鉄化合物粒子はＭｎを０．３〜２５ｗｔ％の範囲で含有している。非磁性鉄化合物粒子のＭｎ含有量が０．３ｗｔ％未満の場合、非磁性鉄化合物粒子の抵抗が制御できずキャリアの電気抵抗が高くなり過ぎ、２５ｗｔ％を超える場合は逆にキャリアの電気抵抗が低くなり過ぎるなどの問題が発生する。なお、非磁性鉄化合物粒子のＭｎ含有量は、好ましくは３〜２０ｗｔ％の範囲であり、より好ましくは５〜１５ｗｔ％の範囲である。 Moreover, the nonmagnetic iron compound particles contained in the spherical composite particles in the present invention contain Mn in a range of 0.3 to 25 wt%. When the Mn content of the non-magnetic iron compound particles is less than 0.3 wt%, the resistance of the non-magnetic iron compound particles cannot be controlled, and the electric resistance of the carrier becomes too high. Problems such as becoming too low. In addition, the Mn content of the nonmagnetic iron compound particles is preferably in the range of 3 to 20 wt%, more preferably in the range of 5 to 15 wt%.
また、本発明における球状複合体粒子はＭｎを０．２〜１０ｗｔ％の範囲で含有していることが好ましい。球状複合体粒子のＭｎ含有量が０．２ｗｔ％未満の場合、球状複合体粒子の抵抗が制御できずキャリアの電気抵抗が高くなり過ぎ、１０ｗｔ％を超える場合は逆にキャリアの電気抵抗が低くなり過ぎるなどの問題が発生する。なお、球状複合体粒子のＭｎ含有量はより好ましくは０．５〜１０ｗｔ％の範囲であり、さらに好ましくは１．０〜５ｗｔ％の範囲である。 Moreover, it is preferable that the spherical composite particles in the present invention contain Mn in a range of 0.2 to 10 wt%. When the Mn content of the spherical composite particles is less than 0.2 wt%, the resistance of the spherical composite particles cannot be controlled and the electric resistance of the carrier becomes too high. When the content exceeds 10 wt%, the electric resistance of the carrier is low. Problems such as becoming too much occur. In addition, the Mn content of the spherical composite particles is more preferably in the range of 0.5 to 10 wt%, and further preferably in the range of 1.0 to 5 wt%.
本発明における球状複合体粒子は、球状複合体粒子中における強磁性鉄化合物の平均粒径ｒａと非磁性鉄化合物粒子の平均粒径ｒｂとの比ｒｂ／ｒａが１．０を越えている。ｒｂ／ｒａは、好ましくは１．２〜５．０の範囲である。ｒｂ／ｒａが１．０以下の場合には、強磁性鉄化合物粒子と非磁性鉄化合物粒子との大きさに差がなくなるか又は強磁性鉄化合物粒子のほうがむしろ相対的に大きくなるため、表面に占める強磁性鉄化合物粒子の比率が増加することになり、樹脂による被覆層の形成を行う前の球状複合体粒子の電気抵抗が低くなってしまう。なお、均一な混合のためには、ｒｂ／ｒａは５．０以下であるのが好ましい。 Spherical composite particles in the present invention, the ratio r b / r a between the average particle size r b of the average particle diameter r a nonmagnetic iron compound particles of the ferromagnetic iron compound in spherical composite particles is 1.0 It is over. r b / r a is preferably in the range of 1.2 to 5.0. When r b / r a is 1.0 or less, there is no difference in size between the ferromagnetic iron compound particles and the non-magnetic iron compound particles, or the ferromagnetic iron compound particles are relatively larger. As a result, the ratio of the ferromagnetic iron compound particles in the surface increases, and the electrical resistance of the spherical composite particles before the formation of the coating layer with the resin is lowered. For uniform mixing, r b / r a is preferably 5.0 or less.
本発明における球状複合体粒子は、嵩密度が２．５ｇ／ｃｍ３程度以下の範囲にあることが好ましい。より好ましくは２．０ｇ／ｃｍ３程度以下である。 The spherical composite particles in the present invention preferably have a bulk density in the range of about 2.5 g / cm 3 or less. More preferably, it is about 2.0 g / cm 3 or less.
本発明における球状複合体粒子は、比重が２．５〜５．２であることが好ましい。より好ましくは３．０〜４．５である。 The spherical composite particles in the present invention preferably have a specific gravity of 2.5 to 5.2. More preferably, it is 3.0-4.5.
本発明における球状複合体粒子は、球状複合体粒子の表面のＳｍｒ１が２％〜１０％であることが好ましい。Ｓｍｒ１とはＩＳＯ２５１７８に定められた三次元表面性状のパラメータのひとつであり、測定した表面の粗さ曲線の高さの方向を縦軸に、ある高さにおけるその高さ以上の領域の面積の割合である負荷面積率を横軸にとった負荷曲線のグラフにおいて、突出山部とコア部とを分離する等価直線が負荷曲線と交わる点の負荷面積率のことである。Ｓｍｒ１が大きいほど一定以上の高さを持つ凸部が多いことが推測される。本発明においては、Ｓｍｒ１が２％未満だと球状複合体粒子表面が平滑になり、トナースペントやトナー劣化が発生しやすくなり電子写真用キャリアとしての高寿命化が期待できない。また、キャリアの流動性が高くなりすぎて、トナーとの混合性が悪化し、トナーに安定した帯電量を付与できない。一方、Ｓｍｒ１が１０％を超えると表面凸部が大きすぎて凸部によるトナーへのストレスが大きくなりトナー劣化が促進してしまうため好ましくない。 The spherical composite particles in the present invention preferably have Smr1 of 2% to 10% on the surface of the spherical composite particles. Smr1 is one of the three-dimensional surface property parameters defined in ISO25178. The vertical direction is the height direction of the measured surface roughness curve, and the ratio of the area of the area above that height at a certain height. In the graph of the load curve with the load area ratio being the horizontal axis, the load area ratio at the point where the equivalent straight line separating the protruding peak portion and the core portion intersects the load curve. It is presumed that the larger the Smr1, the more convex portions having a certain height or more. In the present invention, when Smr1 is less than 2%, the surface of the spherical composite particles becomes smooth, and toner spent and toner deterioration tend to occur, so that it is not possible to expect a long life as an electrophotographic carrier. Further, the fluidity of the carrier becomes too high, and the miscibility with the toner deteriorates, so that a stable charge amount cannot be imparted to the toner. On the other hand, if Smr1 exceeds 10%, the surface convex portion is too large, and the stress on the toner by the convex portion is increased to promote toner deterioration, which is not preferable.
本発明における球状複合体粒子は、球状複合体粒子の表面のＳｐｋが０．１〜１．０μｍであることが好ましい。ＳｐｋとはＩＳＯ２５１７８に定められた三次元表面性状のパラメータのひとつであり、測定した表面の粗さ曲線においてコア部の上にある突出山部の平均高さのことである。Ｓｐｋにより凸部の高さを評価できる。本発明においては、Ｓｐｋが０．１μｍ未満だと球状複合体粒子表面が平滑になり、トナースペントやトナー劣化が発生しやすくなり電子写真用キャリアとしての高寿命化が期待できない。また、キャリアの流動性が高くなりすぎて、トナーとの混合性が悪化し、トナーに安定した帯電量を付与できない。一方、Ｓｐｋが１μｍを超えると表面凸部が大きすぎて凸部によるトナーへのストレスが大きくなりトナー劣化が促進してしまうため好ましくない。 The spherical composite particles in the present invention preferably have a Spk of 0.1 to 1.0 μm on the surface of the spherical composite particles. Spk is one of the three-dimensional surface property parameters defined in ISO25178, and is the average height of the protruding ridge above the core in the measured surface roughness curve. The height of the convex portion can be evaluated by Spk. In the present invention, when the Spk is less than 0.1 μm, the spherical composite particle surface becomes smooth, and toner spent and toner deterioration are likely to occur, so that it is not possible to expect a long life as an electrophotographic carrier. Further, the fluidity of the carrier becomes too high, and the miscibility with the toner deteriorates, so that a stable charge amount cannot be imparted to the toner. On the other hand, if Spk exceeds 1 μm, the surface convex portion is too large, and the stress on the toner by the convex portion is increased to promote toner deterioration, which is not preferable.
本発明における球状複合体粒子は、飽和磁化値が２０〜１００ｅｍｕ／ｇである。２０ｅｍｕ／ｇ未満の場合、いわゆる『穂』を形成する磁気力が弱く、キャリア飛散やキャリア付着が生じやすくなる。１００ｅｍｕ／ｇを越える磁化値は通常の強磁性鉄化合物粒子を用いては得難く、また、画像が荒くなりやすいので好ましくない。 The spherical composite particles in the present invention have a saturation magnetization value of 20 to 100 emu / g. When it is less than 20 emu / g, the magnetic force for forming the so-called “ear” is weak, and carrier scattering and carrier adhesion tend to occur. Magnetization values exceeding 100 emu / g are not preferable using ordinary ferromagnetic iron compound particles, and the image tends to be rough, which is not preferable.
本発明における球状複合体粒子は、体積固有抵抗値が１０１０〜１０１１Ωｃｍである。１０１０Ωｃｍ未満の場合、静電潜像上の電荷がキャリアを介して流れてしまい、画像が乱れる、または欠けたりすることとなり好ましくない。１０１１Ωｃｍを越える場合、キャリア電荷のリークが生じにくくなり、トナーの帯電量も高くなって、黒ベタ部の中央で画像濃度が非常に薄くなるなどの問題が生じる。 The spherical composite particles in the present invention have a volume resistivity value of 10 10 to 10 11 Ωcm. If it is less than 10 10 Ωcm, the charge on the electrostatic latent image flows through the carrier, which is not preferable because the image is disturbed or missing. If it exceeds 10 11 Ωcm, it becomes difficult for the carrier charge to leak, the toner charge amount becomes high, and the image density becomes very thin at the center of the solid black portion.
次に、本発明における球状複合体粒子の製造法について述べる。 Next, a method for producing spherical composite particles in the present invention will be described.
本発明における球状複合体粒子は、強磁性鉄化合物粒子と非磁性鉄化合物粒子とフェノール類とアルデヒド類とを塩基性触媒の存在下で水性媒体中で反応させて得ることができる。 The spherical composite particles in the present invention can be obtained by reacting ferromagnetic iron compound particles, nonmagnetic iron compound particles, phenols and aldehydes in an aqueous medium in the presence of a basic catalyst.
本発明に用いる強磁性鉄化合物粒子としては、マグネタイト、マグヘマイト等の強磁性鉄化合物粒子、鉄以外の金属（Ｍｎ，Ｎｉ，Ｚｎ，Ｍｇ，Ｃｕ等）を一種又は二種以上含有するスピネルフェライト粒子、バリウムフェライト等のマグネトプランバイト型フェライト粒子、表面に酸化被膜を有する鉄や鉄合金の微粒子を用いることができる。好ましくは、マグネタイト等の強磁性鉄化合物粒子である。前記強磁性鉄化合物粒子の粒径は、０．０２〜１０μｍであることが望ましく、水性媒体中における分散と生成する球状複合体粒子の強度を考慮すれば、０．０５〜５μｍであることが好ましい。その形状は、粒状、球状、針状のいずれであってもよい。 The ferromagnetic iron compound particles used in the present invention include ferromagnetic iron compound particles such as magnetite and maghemite, and spinel ferrite particles containing one or more metals other than iron (Mn, Ni, Zn, Mg, Cu, etc.). Further, magnetoplumbite type ferrite particles such as barium ferrite, and iron or iron alloy fine particles having an oxide film on the surface can be used. Ferromagnetic iron compound particles such as magnetite are preferable. The particle size of the ferromagnetic iron compound particles is preferably 0.02 to 10 μm, and is 0.05 to 5 μm in consideration of dispersion in an aqueous medium and strength of the formed spherical composite particles. preferable. The shape may be any of granular, spherical and acicular.
本発明に用いる非磁性鉄化合物粒子としては、ヘマタイト、ゲーサイト及びイルメナイト等の微粒子を用いることができる。好ましくはヘマタイトである。前記非磁性鉄化合物粒子の粒径は、０．０２〜１０μｍであることが望ましく、水性媒体中における分散と生成する複合体粒子の強度、また、その表面凸部の大きさを考慮すれば、０．１〜８μｍであることが好ましい。さらに好ましくは０．３〜５μｍである。その形状については、粒状、球状、針状のいずれであってもよい。なお、非磁性鉄化合物粒子とは１０ｋＯｅの外部磁場中で飽和磁化値が５ｅｍｕ／ｇ以下の鉄化合物粒子をいう。 As the nonmagnetic iron compound particles used in the present invention, fine particles such as hematite, goethite and ilmenite can be used. Hematite is preferable. The non-magnetic iron compound particles preferably have a particle size of 0.02 to 10 μm, and considering the dispersion in an aqueous medium and the strength of the resulting composite particles, and the size of the surface protrusions, It is preferable that it is 0.1-8 micrometers. More preferably, it is 0.3-5 micrometers. The shape may be any of granular, spherical and acicular. The nonmagnetic iron compound particles mean iron compound particles having a saturation magnetization value of 5 emu / g or less in an external magnetic field of 10 kOe.
本発明に用いる非磁性鉄化合物粒子のＭｎ含有量は０．３〜２５ｗｔ％である。非磁性鉄化合物粒子がＭｎを含有することで、非磁性鉄化合物の抵抗が低下し、キャリアとしての抵抗を適度に制御することができる。 The Mn content of the nonmagnetic iron compound particles used in the present invention is 0.3 to 25 wt%. When the nonmagnetic iron compound particles contain Mn, the resistance of the nonmagnetic iron compound is reduced, and the resistance as a carrier can be appropriately controlled.
以下にＭｎを含有する非磁性鉄化合物の製造方法の一例としてヘマタイト粒子の製造方法について述べる。 A method for producing hematite particles will be described below as an example of a method for producing a nonmagnetic iron compound containing Mn.
ヘマタイト粒子は、Ｆｅ２＋水溶液とＭｎ２＋水溶液とアルカリ水溶液とを反応器に加え、所定の温度を維持し、反応溶液に機械的に撹拌を行うとともに、酸化反応を行い、反応終了後、濾過、水洗、乾燥、粉砕を行って得られた強磁性鉄化合物粒子を加熱焼成した後、粉砕を行って得られる。 The hematite particles are added to an Fe 2+ aqueous solution, an Mn 2+ aqueous solution, and an alkaline aqueous solution to maintain a predetermined temperature, mechanically agitate the reaction solution, perform an oxidation reaction, and after completion of the reaction, filtration, The ferromagnetic iron compound particles obtained by washing with water, drying and pulverization are heated and fired, and then pulverized.
本発明の反応に用いるＦｅ２＋水溶液としては、例えば、硫酸第一鉄や塩化第一鉄などの一般的な鉄化合物の水溶液を用いることができる。またアルカリ溶液には、水酸化ナトリウム、炭酸ナトリウムなどのアルカリ水溶液を用いることができる。各々の原料は、経済性や反応効率などを考慮して選択すればよい。 As the Fe 2+ aqueous solution used in the reaction of the present invention, for example, an aqueous solution of a general iron compound such as ferrous sulfate or ferrous chloride can be used. Further, an alkaline aqueous solution such as sodium hydroxide or sodium carbonate can be used as the alkaline solution. Each raw material may be selected in consideration of economy and reaction efficiency.
Ｍｎを含有するヘマタイト粒子を得るには、反応溶液にＭｎ２＋水溶液を添加すればよい。Ｍｎ２＋水溶液としては、硫酸マンガンや塩化マンガン等を用いることができ、工業的には硫酸マンガンが好ましい。 To obtain hematite particles containing Mn, a Mn 2+ aqueous solution may be added to the reaction solution. As the Mn 2+ aqueous solution, manganese sulfate, manganese chloride or the like can be used, and manganese sulfate is industrially preferable.
また、反応溶液に、Ｚｎ、Ｎｉ、Ｃｕ、Ｔｉ、Ｓｉ、Ａｌ、Ｍｇ、Ｃａから選ばれる１種又は２種以上の元素の塩を添加してもよい。 Further, a salt of one or more elements selected from Zn, Ni, Cu, Ti, Si, Al, Mg, and Ca may be added to the reaction solution.
反応鉄濃度は１．２〜２．０ｍｏｌ／Ｌであることが好ましい。反応鉄濃度が１．２ｍｏｌ／Ｌ未満の場合には、目的の形状と粒子径のものを作製できず、２．０ｍｏｌ／Ｌより大きい場合には高粘性となり工業的に製造が困難になる。また、反応マンガン濃度については、非磁性鉄化合物粒子中のＭｎ量が所望の値になるように適宜調整すればよい。 The reactive iron concentration is preferably 1.2 to 2.0 mol / L. When the reactive iron concentration is less than 1.2 mol / L, the target shape and particle size cannot be produced, and when it is greater than 2.0 mol / L, the viscosity becomes high and industrial production becomes difficult. The reactive manganese concentration may be adjusted as appropriate so that the amount of Mn in the nonmagnetic iron compound particles becomes a desired value.
アルカリ水溶液の使用量は、反応水溶液中のＦｅ２＋とＭｎ２＋の合計に対して０．１〜３．０当量が好ましく、より好ましくは０．２〜２．５当量の範囲である。アルカリ水溶液の使用量が０．１当量未満の場合には、未反応の第一鉄塩の残存量が多くなるため工業的でない。また、３．０当量を越える場合には、反応溶液が高粘性となり工業的に製造が困難になる。 The amount of the alkali aqueous solution is 0.1 to 3.0 equivalents are preferred with respect to the total of Fe 2+ and Mn 2+ in the reaction solution, more preferably from 0.2 to 2.5 equivalents. When the amount of the alkaline aqueous solution used is less than 0.1 equivalent, the remaining amount of unreacted ferrous salt increases, which is not industrial. On the other hand, if it exceeds 3.0 equivalents, the reaction solution becomes highly viscous, making it difficult to produce industrially.
本反応において、反応温度は８５〜１００℃である。反応温度が８５℃未満である場合には、針状のゲーサイト粒子が多く生成する。反応温度が１００℃を超える場合も目的の鉄化合物粒子を得ることができるが、オートクレーブ等の装置を必要とするため工業的ではない。 In this reaction, the reaction temperature is 85 to 100 ° C. When the reaction temperature is less than 85 ° C., a lot of needle-like goethite particles are generated. The target iron compound particles can also be obtained when the reaction temperature exceeds 100 ° C., but it is not industrial because an apparatus such as an autoclave is required.
反応後は、常法に従って、水洗、乾燥、粉砕を行って得られる強磁性鉄化合物粒子を酸素雰囲気下で焼成することで、Ｍｎを一定量含有する非磁性鉄化合物粒子であるヘマタイト粒子が得られる。 After the reaction, hematite particles, which are non-magnetic iron compound particles containing a certain amount of Mn, are obtained by firing the ferromagnetic iron compound particles obtained by washing, drying, and pulverizing in a conventional manner in an oxygen atmosphere. It is done.
本発明において、強磁性鉄化合物粒子は、表面処理することなくそのまま用いることができることはもちろんであるが、あらかじめ親油化処理をしておいてもよい。 In the present invention, the ferromagnetic iron compound particles can of course be used as they are without being surface-treated, but may be subjected to a lipophilic treatment in advance.
また、非磁性鉄化合物粒子も同様にそのまま用いることができることはもちろん、あらかじめ親油化処理をしておいてもよい。 In addition, nonmagnetic iron compound particles can be used as they are, and may be subjected to a lipophilic treatment in advance.
親油化処理は、強磁性鉄化合物粒子等にシラン系カップリング剤やチタネート系カップリング剤等のカップリング剤を添加混合して被覆処理する方法又は界面活性剤を含む水性溶媒中に強磁性鉄化合物粒子等を分散させ、該粒子表面に界面活性剤を吸着させる方法等がある。 The oleophilic treatment can be carried out by adding a silane coupling agent or titanate coupling agent to a ferromagnetic iron compound particle, etc., and coating the mixture, or in an aqueous solvent containing a surfactant. There is a method in which iron compound particles and the like are dispersed and a surfactant is adsorbed on the surface of the particles.
シラン系カップリング剤としては、疎水性基、アミノ基、エポキシ基を有するものがあり、疎水性基を有するシラン系カップリング剤としては、ビニルトリクロルシラン、ビニルトリエトキシシラン、ビニル・トリス（β−メトキシ）シラン等がある。 Silane coupling agents include those having a hydrophobic group, amino group, and epoxy group, and silane coupling agents having a hydrophobic group include vinyltrichlorosilane, vinyltriethoxysilane, vinyl tris (β -Methoxy) silane and the like.
アミノ基を有するシラン系カップリング剤としては、γ−アミノプロピルトリエトキシシラン、Ｎ−β−（アミノエチル）─γ−アミノプロピルトリメトキシシラン、Ｎ−β−（アミノエチル）−γ−アミノプロピルメチルジメトキシシラン、Ｎ−フェニル−γ−アミノプロピルトリメトキシシラン等がある。 Examples of the silane coupling agent having an amino group include γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyl. Examples include methyldimethoxysilane and N-phenyl-γ-aminopropyltrimethoxysilane.
エポキシ基を有するシラン系カップリング剤としては、γ−グリシドキシプロピルメチルジエトキシシラン、γ−グリシドキシプロピルトリメトキシシラン、β−（３，４−エポキシシクロヘキシル）トリメトキシシラン等がある。 Examples of the silane coupling agent having an epoxy group include γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) trimethoxysilane, and the like.
チタネート系カップリング剤としては、イソプロピルトリイソステアロイルチタネート、イソプロピルトリドデシルベンゼンスルホニルチタネート、イソプロピルトリス（ジオクチルピロホスフェート）チタネート等がある。 Examples of titanate coupling agents include isopropyl triisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, and isopropyl tris (dioctyl pyrophosphate) titanate.
界面活性剤としては、市販の界面活性剤を使用することができ、強磁性鉄化合物粒子、非磁性鉄化合物粒子や該粒子表面に有する水酸基と結合が可能な官能基を有するものが望ましく、イオン性で言えばカチオン性、あるいはアニオン性のものが好ましい。 As the surfactant, commercially available surfactants can be used, and those having a functional group capable of bonding with a ferromagnetic iron compound particle, non-magnetic iron compound particle, or a hydroxyl group on the surface of the particle are desirable. Speaking of properties, those that are cationic or anionic are preferred.
上記いずれの親油化処理方法によっても本発明の目的を達成することができるが、フェノール樹脂との接着性を考慮するとアミノ基、あるいはエポキシ基を有するシラン系カップリング剤による処理が好ましい。 The object of the present invention can be achieved by any of the above oleophilic treatment methods, but treatment with a silane coupling agent having an amino group or an epoxy group is preferred in view of adhesiveness with a phenol resin.
本発明に用いるフェノール類としては、フェノール自体の他、ｍ−クレゾール、ｐ−ｔｅｒｔ−ブチルフェノール、ｏ−プロピルフェノール、レゾルシノール、ビスフェノールＡ等のアルキルフェノール類、及びベンゼン核又はアルキル基の一部又は全部が塩素原子臭素原子で置換されたハロゲン化フェノール類等のフェノール性水酸基を有する化合物が挙げられるが、この中でフェノールが最も好ましい。フェノール類以外のものを用いた場合には、球状複合体粒子が生成し難かったり、粒子が生成したとしても不定形状であったりすることがある。 As phenols used in the present invention, in addition to phenol itself, alkylphenols such as m-cresol, p-tert-butylphenol, o-propylphenol, resorcinol, and bisphenol A, and a part or all of benzene nucleus or alkyl group are included. Although compounds having a phenolic hydroxyl group such as halogenated phenols substituted with a chlorine atom or a bromine atom are exemplified, phenol is most preferred. When a material other than phenols is used, spherical composite particles may be difficult to produce, or even if particles are produced, they may have an indefinite shape.
本発明に用いるアルデヒド類としては、ホルマリン又はパラアルデヒドのいずれかの形態のホルムアルデヒド及びフルフラール等が挙げられるが、ホルムアルデヒドが特に好ましい。 Examples of aldehydes used in the present invention include formaldehyde and furfural in the form of either formalin or paraaldehyde, and formaldehyde is particularly preferable.
アルデヒド類のフェノール類に対するモル比は、１〜２が好ましく、特に好ましくは１．１〜１．６である。アルデヒド類のフェノール類に対するモル比が１より小さいと、球状複合体粒子が生成し難かったり、生成したとしても樹脂の硬化が進行し難いために、生成する粒子の強度が弱かったりする傾向があり、一方、アルデヒド類のフェノール類に対するモル比が２よりも大きいと、反応後に水性媒体中に残留する未反応のアルデヒド類が増加する傾向がある。 The molar ratio of aldehydes to phenols is preferably 1 to 2, particularly preferably 1.1 to 1.6. If the molar ratio of aldehydes to phenols is less than 1, spherical composite particles are difficult to produce, or even if they are produced, the resin does not progress easily, so the strength of the produced particles tends to be weak. On the other hand, when the molar ratio of aldehydes to phenols is larger than 2, unreacted aldehydes remaining in the aqueous medium after the reaction tend to increase.
本発明に用いる塩基性触媒としては、通常のレゾール樹脂製造に使用されているもの、例えば、アンモニア水、ヘキサメチレンテトラミン及びジメチルアミン、ジエチルトリアミン、ポリエチレンイミン等のアルキルアミンが挙げられる。これら塩基性触媒のフェノール類に対するモル比は、０．０２〜０．３が好ましい。 As a basic catalyst used for this invention, what is used for normal resole resin manufacture, For example, alkylamines, such as aqueous ammonia, hexamethylenetetramine, dimethylamine, diethyltriamine, polyethyleneimine, are mentioned. The molar ratio of these basic catalysts to phenols is preferably 0.02 to 0.3.
前記フェノール類とアルデヒド類を塩基性触媒の存在下で反応させるに際し、共存させる強磁性鉄化合物粒子及び非磁性鉄化合物粒子の量は、フェノール類に対して重量で０．５〜２００倍が好ましい。さらに、生成する球状複合体粒子の強度を考慮すると、４〜１００倍であることがより好ましい。 When the phenols and aldehydes are reacted in the presence of a basic catalyst, the amount of the ferromagnetic iron compound particles and non-magnetic iron compound particles to be present is preferably 0.5 to 200 times by weight with respect to the phenols. . Furthermore, considering the strength of the spherical composite particles to be generated, it is more preferably 4 to 100 times.
本発明において球状複合体粒子を生成する反応は、水性媒体中で行われるが、この場合の水仕込み量は、強磁性鉄化合物粒子及び非磁性鉄化合物粒子の総量が原料全体に占める割合である全固形分濃度が３０〜９５ｗｔ％になるようにすることが好ましく、特に、６０〜９０ｗｔ％となるようにすることが好ましい。 In the present invention, the reaction for forming the spherical composite particles is carried out in an aqueous medium. In this case, the amount of water charged is the ratio of the total amount of the ferromagnetic iron compound particles and the nonmagnetic iron compound particles to the whole raw material. The total solid content concentration is preferably 30 to 95 wt%, and particularly preferably 60 to 90 wt%.
以下に本発明に係る球状複合体粒子の製造方法の一例を示す。 An example of a method for producing spherical composite particles according to the present invention is shown below.
反応は、まず、フェノール類、ホルマリン類、水及び強磁性鉄化合物粒子を反応釜中に仕込み、十分に攪拌した後、塩基性触媒を加えて攪拌しながら昇温し、反応温度を４５〜６０℃に調整する。この時点において、フェノール類及びホルマリン類の一部の反応が進行し、ゲル状のフェノール樹脂マトリックス中に強磁性鉄化合物粒子が分散したゲル状の球状複合体核粒子が生成する。球形度の高い球状複合体粒子を得るためにはゆるやかに昇温することが望ましいが、一方、フェノール樹脂の硬化があまり進行しないことが望まれる。昇温速度は、好ましくは０．５〜１．５℃／分、より好ましくは０．８〜１．２℃／分である。 In the reaction, first, phenols, formalins, water and ferromagnetic iron compound particles are charged into a reaction kettle and stirred sufficiently, followed by addition of a basic catalyst and heating while stirring to raise the reaction temperature to 45-60. Adjust to ° C. At this point, a partial reaction of phenols and formalins proceeds, and gel-like spherical composite core particles in which ferromagnetic iron compound particles are dispersed in a gel-like phenol resin matrix are generated. In order to obtain spherical composite particles having a high degree of sphericity, it is desirable to raise the temperature gently, but on the other hand, it is desirable that the curing of the phenol resin does not proceed so much. The rate of temperature rise is preferably 0.5 to 1.5 ° C./min, more preferably 0.8 to 1.2 ° C./min.
非磁性鉄化合物粒子の添加は、前記ゲル状球状複合体核粒子が生成した後に行う。添加時の液温は４５〜６０℃の間である。強磁性鉄化合物粒子の大部分がゲル状球状複合体粒子中に取り込まれて、単独で存在する強磁性鉄化合物粒子がほとんどない状態であって、しかもバインダであるフェノール樹脂が十分には硬化していないゲル状である状態において、非磁性鉄化合物粒子を添加する。このように非磁性鉄化合物粒子を後から添加することで球状複合体粒子の表面にヘマタイト粒子が存在しやすくなり、粒子表面に適当な凸部を形成することができる。 The nonmagnetic iron compound particles are added after the gel-like spherical composite core particles are formed. The liquid temperature at the time of addition is between 45-60 degreeC. Most of the ferromagnetic iron compound particles are incorporated into the gel-like spherical composite particles, and there is almost no ferromagnetic iron compound particles present alone, and the phenol resin as the binder is sufficiently cured. In a non-gelling state, nonmagnetic iron compound particles are added. Thus, by adding nonmagnetic iron compound particles later, hematite particles are likely to be present on the surface of the spherical composite particles, and appropriate convex portions can be formed on the particle surface.
反応温度が６０℃を越えてフェノール樹脂が十分硬化してしまった後に非磁性鉄化合物を添加した場合には、生成する球状複合体粒子中に非磁性鉄化合物粒子が含有されないか、あるいは当該球状複合体粒子表面に非磁性鉄化合物粒子が付着しただけのものが生成する。 When the nonmagnetic iron compound is added after the reaction temperature exceeds 60 ° C. and the phenol resin is sufficiently cured, the resulting spherical composite particles do not contain the nonmagnetic iron compound particles, or the spherical Only the nonmagnetic iron compound particles adhered to the surface of the composite particles are generated.
反応温度が４５℃未満で非磁性鉄化合物粒子の添加を早期に行った場合、あるいは反応当初から強磁性鉄化合物と共に非磁性鉄化合物粒子を添加した場合にも、粒子径のバランスにより粒子表面に非磁性鉄化合物粒子が多く存在する球状複合体粒子を生成することも可能であるが、非磁性鉄化合物粒子が球状複合体粒子核部にも存在しやすくなる。 Even when nonmagnetic iron compound particles are added early at a reaction temperature of less than 45 ° C., or when nonmagnetic iron compound particles are added together with a ferromagnetic iron compound from the beginning of the reaction, the particle diameter balances the particle surface. Although it is possible to produce spherical composite particles in which many nonmagnetic iron compound particles are present, the nonmagnetic iron compound particles are likely to exist also in the spherical composite particle core.
次に、非磁性鉄化合物粒子を添加後、しばらく攪拌し、ゲル状の球状複合体核粒子表面に非磁性鉄化合物粒子がフェノール樹脂マトリックス中に分散した表層部を形成させ、ゲル状の球状複合体粒子を生成する。その後、攪拌しながら昇温し、反応温度７０〜９０℃に調整し、フェノール樹脂を硬化させる。この時も前記同様、球形度の高い球状複合体粒子を得るためにゆるやかに昇温させることが望ましい。昇温速度は、好ましくは０．５〜１．５℃／分、より好ましくは０．８〜１．２℃／分である。 Next, after adding the non-magnetic iron compound particles, the mixture is stirred for a while to form a surface layer portion in which the non-magnetic iron compound particles are dispersed in the phenolic resin matrix on the surface of the gel-like spherical composite core particles. Generate body particles. Thereafter, the temperature is raised while stirring, the reaction temperature is adjusted to 70 to 90 ° C., and the phenol resin is cured. At this time as well, it is desirable to raise the temperature gently in order to obtain spherical composite particles with high sphericity. The rate of temperature rise is preferably 0.5 to 1.5 ° C./min, more preferably 0.8 to 1.2 ° C./min.
硬化後の反応物を４０℃以下に冷却し、得られた水分散液を濾過、遠心分離等の常法に従って固液を分離した後、洗浄して乾燥することにより、フェノール樹脂マトリックス中に強磁性鉄化合物粒子が主として分散する核部とフェノール樹脂マトリックス中に非磁性鉄化合物粒子が主として分散する表層部とからなる球状複合体粒子が得られる。 The cured reaction product is cooled to 40 ° C. or lower, and the resulting aqueous dispersion is separated into solid and liquid according to conventional methods such as filtration and centrifugation. Spherical composite particles comprising a core part in which magnetic iron compound particles are mainly dispersed and a surface layer part in which nonmagnetic iron compound particles are mainly dispersed in a phenol resin matrix are obtained.
＜作用＞
前述のように電子写真用キャリアとして必要な特性としては、飽和磁化値、電気抵抗値、比重などの各特性が適当に制御されていることである。例えば、高い磁化値を得るために強磁性粒子の割合を高めていくと、通常、電気抵抗値が低くなってしまい、１０１０Ωｃｍ以上の高い電気抵抗値は得られない。そこで１０１０Ωｃｍ以上の電気抵抗値を得るために絶縁性の樹脂等を添加することが考えられるが、添加される樹脂等は通常強磁性に比べて比重が小さく、全体として十分な比重が得られなくなる。
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As described above, the characteristics necessary for the electrophotographic carrier are that the characteristics such as the saturation magnetization value, the electric resistance value, and the specific gravity are appropriately controlled. For example, when the proportion of ferromagnetic particles is increased in order to obtain a high magnetization value, the electrical resistance value usually decreases, and a high electrical resistance value of 10 10 Ωcm or more cannot be obtained. In order to obtain an electric resistance value of 10 10 Ωcm or more, it is conceivable to add an insulating resin or the like. However, the resin or the like to be added usually has a specific gravity smaller than that of ferromagnetism, and a sufficient specific gravity is obtained as a whole. It becomes impossible.
従来、高抵抗である非磁性鉄化合物粒子をキャリアの表面に局在化させるなどしてキャリアの電気抵抗の制御を行ってきたが、この粒子自体の抵抗が非常に高いため、キャリア表面の電気抵抗の制御には好ましいものとはいえない。そこで、本発明者らは、キャリアにおいて、高い磁化値を得るための強磁性鉄化合物粒子を主として含有する核部の表面に、Ｍｎを含有させることにより電気抵抗が制御された非磁性鉄化合物粒子を主として含有する表層部を形成し、電気抵抗の制御を行うことを検討した。 Conventionally, the electrical resistance of the carrier has been controlled by localizing the high-resistance non-magnetic iron compound particles on the surface of the carrier.However, since the resistance of the particles themselves is very high, This is not preferable for resistance control. Therefore, the inventors of the present invention have proposed that non-magnetic iron compound particles whose electrical resistance is controlled by containing Mn on the surface of a core part mainly containing ferromagnetic iron compound particles for obtaining a high magnetization value in a carrier. An investigation was made to control the electrical resistance by forming a surface layer mainly containing.
前述のような非磁性鉄化合物粒子を得るために、該非磁性鉄化合物粒子を作製するにあたって、Ｍｎの塩の添加を行うことが重要である。すなわち、一定量以上のＭｎの塩が添加された状態で非磁性鉄化合物粒子を作製した場合、非磁性鉄化合物粒子の電気抵抗が下がり、適度に電気抵抗が制御された非磁性鉄化合物粒子が得られる。非磁性鉄化合物粒子の抵抗が低下した原理は明らかではないが、本発明者らは、非磁性鉄化合物粒子の表面に低抵抗のＭｎ固溶体が生成したためであると考えている。 In order to obtain the nonmagnetic iron compound particles as described above, it is important to add a salt of Mn when preparing the nonmagnetic iron compound particles. That is, when nonmagnetic iron compound particles are produced in a state where a certain amount or more of Mn salt is added, the nonmagnetic iron compound particles have a reduced electric resistance and moderately controlled nonmagnetic iron compound particles. can get. Although the principle by which the resistance of the nonmagnetic iron compound particles has decreased is not clear, the present inventors believe that this is because a low-resistance Mn solid solution was formed on the surface of the nonmagnetic iron compound particles.
本発明によって得られたキャリアは、前記のような構造を有することにより、核部の強磁性鉄化合物粒子の含有量を増加することにより高い磁化値を得ることができると共に、表層部に抵抗が制御された非磁性鉄化合物粒子がバインダであるフェノール樹脂中に分散していることにより、比較的高い電気抵抗に制御でき、さらに表面に適当な凸部を持つ。 Since the carrier obtained by the present invention has the structure as described above, it is possible to obtain a high magnetization value by increasing the content of the ferromagnetic iron compound particles in the core portion, and the surface layer portion has a resistance. Since the controlled non-magnetic iron compound particles are dispersed in the phenol resin as a binder, it can be controlled to have a relatively high electric resistance, and has an appropriate convex portion on the surface.
次に、実施例並びに比較例により本発明を説明する。 Next, the present invention will be described with reference to examples and comparative examples.
以下の実施例並びに比較例における球状複合体粒子の平均粒径はレーザー回折式粒度分布計ＬＡ７５０（（株）堀場製作所製）により計測して体積基準による値で示した。 The average particle diameter of the spherical composite particles in the following examples and comparative examples was measured with a laser diffraction particle size distribution analyzer LA750 (manufactured by Horiba, Ltd.) and indicated by a value based on volume.
強磁性鉄化合物粒子の平均粒径ｒａおよび非磁性酸化鉄化合物粒子の平均粒径ｒｂは、透過型電子顕微鏡写真により撮影した写真から、粒子３００個についてフェレ径を測定して求めた値である。 The average particle diameter r b of the average particle size r a and the non-magnetic iron oxide compound particles of the ferromagnetic iron compound particles, from a photograph taken by a transmission electron micrograph was determined by measuring the Feret's diameter for 300 particles value It is.
球状複合体に含まれる強磁性鉄化合物粒子と非磁性鉄化合物粒子の各含有量は球状複合体の飽和磁化値と、球状複合体および各鉄化合物粒子の真比重より求めた値である。 The contents of the ferromagnetic iron compound particles and nonmagnetic iron compound particles contained in the spherical composite are values obtained from the saturation magnetization value of the spherical composite and the true specific gravity of the spherical composite and each iron compound particle.
球状複合体中のＭｎ含有量は、球状複合体を酸によって溶解させて、その溶液のＩＣＰ発光分析測定から算出した。 The Mn content in the spherical composite was calculated from the ICP emission analysis measurement of the solution obtained by dissolving the spherical composite with an acid.
また、強磁性鉄化合物粒子及び非磁性鉄化合物粒子中のＭｎ含有量は、前記粒子を酸によって溶解させて、その溶液のＩＣＰ発光分析測定から算出した。 The Mn content in the ferromagnetic iron compound particles and the nonmagnetic iron compound particles was calculated from ICP emission analysis measurement of the solution obtained by dissolving the particles with an acid.
球状複合体粒子の表面の突出山部とコア部を分離する負荷面積率（Ｓｍｒ１）及び突出山部高さ（Ｓｐｋ）は、３Ｄ測定レーザー顕微鏡ＬＥＸＴ ＯＬＳ４０００（オリンパス製）によってＩＳＯ２５１７８に準拠した方法で測定した。測定領域は、１粒子に対して１６ｘ１６［μｍ］でカットオフ値８０μｍで計測し、さらに任意で選んだ粒子各１０個についての測定値を平均値で示した。 The load area ratio (Smr1) and the protruding peak height (Spk) for separating the protruding peak part and the core part on the surface of the spherical composite particles are measured in accordance with ISO 25178 using a 3D measurement laser microscope LEXT OLS4000 (manufactured by Olympus). It was measured. The measurement area was measured at 16 × 16 [μm] with a cut-off value of 80 μm for one particle, and the measured values for 10 arbitrarily selected particles were shown as an average value.
流動率は、球状複合体粒子を２００ｇ秤量し２３．５℃・６０ＲＨ％の環境で一晩調湿し、１ｋＯｅで着磁する。得られた試料をさらに上記条件で調湿してから、５０ｇ秤量し、パウダーテスター（ホソカワミクロン株式会社）にて設定をＶＩＢ２にして振動させながら内径４．３ｍｍのガラスロートを用いて測定した。 As for the flow rate, 200 g of spherical composite particles are weighed and conditioned in an environment of 23.5 ° C. and 60 RH% overnight, and magnetized with 1 kOe. The obtained sample was further conditioned under the above conditions, then weighed 50 g, and measured using a glass funnel having an inner diameter of 4.3 mm while vibrating with a powder tester (Hosokawa Micron Corporation) with the setting set to VIB2.
嵩密度は、ＪＩＳ Ｋ５１０１に記載の方法に従って測定した。 The bulk density was measured according to the method described in JIS K5101.
真比重はマルチボリウム密度計（島津製作所製１３０５型）で測定した。 The true specific gravity was measured with a multi-volume density meter (1305 type, manufactured by Shimadzu Corporation).
球状複合体粒子の電気抵抗値は、測定対象の試料粉末１．０ｇを秤量し測定容器に入れ２３０ｇの荷重をかけた状態で、１０００Vの定電圧を印加し「ＨＩＧＨ ＲＥＳＩＳＴＡＮＣＥ ＭＥＴＥＲ ４３３９Ｂ」（ヒューレット・パッカード（株）製）で測定し、そのときの抵抗値と試料の電極面積および厚みより体積固有抵抗値を求めた。 The electric resistance value of the spherical composite particles was determined by weighing 1.0 g of the sample powder to be measured, putting it in a measurement container and applying a load of 230 g, applying a constant voltage of 1000 V and applying “HIGH RESISTANCE METER 4339B” (Hewlett The volume specific resistance value was determined from the resistance value, the electrode area and the thickness of the sample.
強磁性鉄化合物粒子および非磁性鉄化合物粒子の電気抵抗値は、測定対象の試料粉末０．５ｇを秤量し測定容器に入れ１４ＭＰａの圧力を加えた状態で、１５Ｖの定電圧を印加し「ＨＩＧＨ ＲＥＳＩＳＴＡＮＣＥ ＭＥＴＥＲ ４３３９Ｂ」（ヒューレット・パッカード（株）製）で測定し、そのときの抵抗値と試料の電極面積および厚みより体積固有抵抗値を求めた。 The electrical resistance values of the ferromagnetic iron compound particles and the non-magnetic iron compound particles were measured by applying a constant voltage of 15 V while weighing a sample powder of 0.5 g and placing it in a measuring container and applying a pressure of 14 MPa. The volume specific resistance value was determined from the resistance value, the electrode area of the sample, and the thickness at that time, using “RESISTANCE METER 4339B” (manufactured by Hewlett-Packard Co.).
飽和磁化は、振動試料型磁力計ＶＳＭ−３Ｓ−１５（東英工業（株）製）を用いて外部磁場７９５．８ｋＡ／ｍ（１０ｋＯｅ）のもとで測定した値で示した。 The saturation magnetization was indicated by a value measured under an external magnetic field of 795.8 kA / m (10 kOe) using a vibrating sample magnetometer VSM-3S-15 (manufactured by Toei Kogyo Co., Ltd.).
実施例１
Ｆｅ２＋を１．６ｍｏｌ／Ｌ含む硫酸第一鉄水溶液２３．７５ＬとＭｎ２＋を１．６ｍｏｌ／Ｌ含む硫酸マンガン水溶液０．２３７５Ｌを、あらかじめ反応器中に準備されたＦｅ２＋とＭｎ２＋に対して０．９５当量に該当する２．７５ｍｏｌ／Ｌの水酸化ナトリウム水溶液２６．５１Ｌに加え、ｐＨ６．５〜７．５、温度９０℃において毎分８０Ｌの空気を通気して酸化反応（第一段反応）を行い、酸化還元電位が上昇する時点でＦｅ２＋が０．０５当量残っている反応溶液にＦｅ２＋１．６ｍｏｌ／Ｌを含む硫酸第一鉄水溶液１．２５Ｌを添加し、この時点で反応器内に残っている３．９ｍｏｌのＦｅ２＋を酸化するために水酸化ナトリウム水溶液を加えて反応器内のスラリーのｐＨを１０〜１２に調整して引き続き酸化反応（第二段反応）を行い、酸化反応を完結してマグネタイト粒子を含むスラリーを得た。このスラリーをろ過・水洗・乾燥・粉砕してＭｎを１．０３ｗｔ％含むマグネタイト粒子の粉末を得た。得られたマグネタイト粒子を酸素雰囲気下で焼成して酸化させ、粉砕し、Ｍｎを１．０ｗｔ％含むヘマタイト粒子を得た。得られたヘマタイト粒子の平均粒径は０．６０μｍだった。
Example 1
23.75 L of ferrous sulfate aqueous solution containing 1.6 mol / L of Fe 2+ and 0.2375 L of manganese sulfate aqueous solution containing 1.6 mol / L of Mn 2+ were added to Fe 2+ and Mn 2+ previously prepared in the reactor. In addition to 26.51 L of 2.75 mol / L sodium hydroxide aqueous solution corresponding to 0.95 equivalent, 80 L of air per minute at pH 6.5 to 7.5 and temperature of 90 ° C. Stage reaction), and 1.25 L of ferrous sulfate aqueous solution containing 1.6 mol / L of Fe 2+ is added to the reaction solution in which 0.05 equivalent of Fe 2+ remains when the oxidation-reduction potential rises. in continuing the oxidation reaction the pH of the slurry was adjusted to 10 to 12 in the reactor by adding sodium hydroxide solution in order to oxidize Fe 2+ in 3.9mol remaining in the reactor (the Perform stage reaction) to obtain a slurry containing magnetite particles was complete the oxidation reaction. This slurry was filtered, washed with water, dried and pulverized to obtain magnetite particle powder containing 1.03 wt% of Mn. The obtained magnetite particles were fired in an oxygen atmosphere to be oxidized and pulverized to obtain hematite particles containing 1.0 wt% Mn. The average particle size of the obtained hematite particles was 0.60 μm.
得られたヘマタイト粒子１２０ｇにシラン系カップリング剤（ＫＢＭ−４０３：信越化学製）を０．６ｇ添加し、約１００℃まで昇温し３０分よく混合撹拌することにより親油化処理されたヘマタイト粒子を得た。 0.6 g of a silane coupling agent (KBM-403: manufactured by Shin-Etsu Chemical Co., Ltd.) is added to 120 g of the obtained hematite particles, the temperature is raised to about 100 ° C., and the mixture is stirred and mixed well for 30 minutes to make lipophilic treatment. Particles were obtained.
また、ヘンシェルミキサー内に平均粒径０．２４μｍのＭｎを０．２ｗｔ％含むマグネタイト粒子２８０ｇを仕込み、良く攪拌した後、シラン系カップリング剤（ＫＢＭ−４０３：信越化学製）２．１ｇを添加し、約１００℃まで昇温し３０分間良く混合攪拌することにより親油化処理されたマグネタイト粒子を得た。 In addition, 280 g of magnetite particles containing 0.2 wt% of Mn having an average particle size of 0.24 μm are charged in a Henschel mixer, and after stirring well, 2.1 g of a silane coupling agent (KBM-403: manufactured by Shin-Etsu Chemical) is added. The mixture was heated to about 100 ° C. and mixed and stirred well for 30 minutes to obtain lipophilic magnetite particles.
次に、１Ｌの四つ口フラスコに、フェノール４０ｇ、３７％ホルマリン６０ｇ、前記のマグネタイト粒子２８０ｇ、２８％アンモニア水１２ｇ、水４０ｇを攪拌、混合しながら、０．７５℃／分の昇温速度で５０℃まで昇温し、マグネタイト粒子がフェノール樹脂中に分散しているゲル状の球状複合体核粒子が生成された時点で、前記のＭｎを１．０ｗｔ％含むヘマタイト粒子を１２０ｇ添加して、前記のゲル状の球状複合体核粒子表面にヘマタイト粒子を含有する表層部を形成してゲル状の球状複合体粒子を生成し、さらに水２０ｇを入れて、１．１７℃／分の昇温速度で８５℃まで昇温して１８０分間保持し、前記ゲル状の球状複合体粒子を硬化させて、強磁性鉄化合物粒子を核部に含有し、非磁性鉄化合物粒子を表層部に含有する球状複合体粒子の生成を行った。 Next, while stirring and mixing 40 g of phenol, 60 g of 37% formalin, 280 g of the magnetite particles, 12 g of 28% ammonia water, and 40 g of water in a 1 L four-necked flask, the heating rate was 0.75 ° C./min. When the gel-like spherical composite core particles in which the magnetite particles are dispersed in the phenol resin are generated, 120 g of the hematite particles containing 1.0 wt% of Mn are added. Then, a surface layer portion containing hematite particles is formed on the surface of the gel-like spherical composite core particles to produce gel-like spherical composite particles, and 20 g of water is further added, and the temperature is increased to 1.17 ° C./min. The temperature is raised to 85 ° C. at a temperature rate and held for 180 minutes, the gel-like spherical composite particles are cured, the ferromagnetic iron compound particles are contained in the core portion, and the nonmagnetic iron compound particles are contained in the surface layer portion. Spherical It went the generation of coalesced particles.
その後、３０℃まで冷却し、０．５Ｌの水を添加した後、上澄み液を除去し、複合体粒子を含む沈殿物を水洗し、風乾した。次いで、これを５ｍｍＨｇ以下の減圧下にて５０〜６０℃で乾燥して球状複合体粒子を得た。 Then, after cooling to 30 ° C. and adding 0.5 L of water, the supernatant was removed, and the precipitate containing the composite particles was washed with water and air-dried. Subsequently, this was dried at 50-60 degreeC under the reduced pressure of 5 mmHg or less, and the spherical composite particle was obtained.
得られた球状複合体粒子は平均粒径が３７．２μｍであり、図１〜３の走査型電子顕微鏡写真（×２２００、５０００，１００００）に示す通り、表面に凸部の存在が確認できる。 The obtained spherical composite particles have an average particle diameter of 37.2 μm, and as shown in the scanning electron micrographs (× 2200, 5000, 10000) of FIGS.
また、得られた球状複合体粒子の飽和磁化値は５２ｅｍｕ／ｇ、真比重は３．７８であり、体積固有抵抗値は９．２×１０１０Ωｃｍであった。球状複合体に含まれる強磁性鉄化合物粒子と非磁性鉄化合物粒子の各含有量は球状複合体の飽和磁化値と、球状複合体および各鉄化合物粒子の真比重より算出した結果、強磁性鉄化合物粒子は６３．１ｗｔ％、非磁性鉄化合物粒子は２７．１ｗｔ％、フェノール樹脂は９．８ｗｔ％であった。また、球状複合体粒子中のＭｎ量は０．４ｗｔ％であった。 The obtained spherical composite particles had a saturation magnetization value of 52 emu / g, a true specific gravity of 3.78, and a volume resistivity value of 9.2 × 10 10 Ωcm. The content of ferromagnetic iron compound particles and non-magnetic iron compound particles contained in the spherical composite was calculated from the saturation magnetization value of the spherical composite and the true specific gravity of the spherical composite and each iron compound particle. The compound particles were 63.1 wt%, the nonmagnetic iron compound particles were 27.1 wt%, and the phenol resin was 9.8 wt%. Further, the amount of Mn in the spherical composite particles was 0.4 wt%.
なお、球状複合体粒子は赤みがかった黒色を呈しており、このことからも表層部に非磁性鉄化合物粒子が主として含有されていることがわかる。 The spherical composite particles have a reddish black color, and this also indicates that the surface layer portion mainly contains nonmagnetic iron compound particles.
実施例２〜６、比較例１
非磁性鉄化合物粒子中のＭｎ量を表１に示すように変化させた以外は、実施例１と同様にして、反応、硬化させて球状複合体粒子を得た。
Examples 2-6, Comparative Example 1
Spherical composite particles were obtained by reacting and curing in the same manner as in Example 1 except that the amount of Mn in the nonmagnetic iron compound particles was changed as shown in Table 1.
実施例７〜８、比較例２〜３
非磁性鉄化合物粒子の粒径と非磁性鉄化合物粒子中のＭｎ量を表１に、シランカップリング剤処理量を表２に示すように変化させた以外は、実施例１と同様にして、反応、硬化させて球状複合体粒子を得た。
Examples 7-8, Comparative Examples 2-3
Except for changing the particle size of the non-magnetic iron compound particles and the amount of Mn in the non-magnetic iron compound particles in Table 1 and the amount of silane coupling agent treatment as shown in Table 2, the same as in Example 1, Reaction and curing were performed to obtain spherical composite particles.
得られた球状複合体粒子の諸特性は表３に示した。 Various characteristics of the obtained spherical composite particles are shown in Table 3.
本発明における球状複合体粒子は、強磁性鉄化合物粒子を主として含有する核部と電気抵抗を高度に制御された非磁性鉄化合物粒子を主として含有する表層部とを有し、さらに適当な表面凸部をもつことにより、適当な飽和磁化値、殊に２０〜１００ｅｍｕ／ｇ程度を有すると共に、比較的高い電気抵抗値、殊に１０１０〜１０１１Ωｃｍ程度とを有し、適当なＳｍｒ１をもつものであり、高画質化や高寿命化、高速化及び連続化が実現できる電子写真用磁性キャリアとして好適である。 The spherical composite particles in the present invention have a core portion mainly containing ferromagnetic iron compound particles and a surface layer portion mainly containing non-magnetic iron compound particles whose electric resistance is highly controlled, and further suitable surface protrusions. Having an appropriate saturation magnetization value, particularly about 20 to 100 emu / g, and a relatively high electric resistance value, particularly about 10 10 to 10 11 Ωcm, and having an appropriate Smr1 Therefore, it is suitable as a magnetic carrier for electrophotography that can realize high image quality, long life, high speed, and continuity.
本発明における球状複合体粒子は、上記諸特性を有することから、キャリアとして使用した場合には、トナーとの混合性が良く、その結果、トナーの帯電速度を速めることができ、また、トナーにダメージを与えることなく、スペント化も抑制することができ、さらに、過度のトナー帯電量が抑制でき、長期間キャリアの使用を続けても安定したトナー帯電量が保持できる。
Since the spherical composite particles in the present invention have the above-mentioned characteristics, when used as a carrier, the spherical composite particles have good mixing properties with the toner, and as a result, the charging speed of the toner can be increased. Spenting can be suppressed without causing damage, and an excessive toner charge amount can be suppressed, and a stable toner charge amount can be maintained even if the carrier is used for a long time.
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| JPS63184764A (en) * | 1986-09-02 | 1988-07-30 | Kawasaki Steel Corp | Carrier for electrophotographic developer and production thereof |
| JP2802543B2 (en) * | 1990-10-02 | 1998-09-24 | 戸田工業株式会社 | Manufacturing method of non-magnetic black pigment powder |
| JP3006657B2 (en) * | 1994-06-23 | 2000-02-07 | 戸田工業株式会社 | Magnetic carrier for electrophotography and method for producing the same |
| JP3259749B2 (en) * | 1994-10-05 | 2002-02-25 | 戸田工業株式会社 | Magnetic carrier for electrophotography |
| JP3284488B2 (en) * | 1994-10-05 | 2002-05-20 | キヤノン株式会社 | Two-component developer, developing method and image forming method |
| JPH10116717A (en) * | 1996-10-14 | 1998-05-06 | Fuji Elelctrochem Co Ltd | Oxide magnetic material and carrier using the same |
| JP2000010344A (en) * | 1998-04-20 | 2000-01-14 | Toda Kogyo Corp | Black composite nonmagnetic particle powder for black toner and black toner using this black composite nonmagnetic particle powder |
| JP2002139865A (en) * | 2000-11-01 | 2002-05-17 | Fuji Xerox Co Ltd | Electrophotographic black toner composition, electrophotographic two-component developer and image forming method |
| JP4246907B2 (en) * | 2000-11-20 | 2009-04-02 | 株式会社リコー | Electrostatic latent image color developing method, developing apparatus, and developing toner |
| JP3943977B2 (en) * | 2002-04-01 | 2007-07-11 | キヤノン株式会社 | Magnetic material-dispersed resin carrier and two-component developer |
| EP1406129B8 (en) * | 2002-10-02 | 2012-05-23 | Canon Kabushiki Kaisha | Silica fine particle, toner, two-component developer and image forming method |
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