Magnetic fluid.

[Detailed Description of the Invention]

The present invention relates to improvement of the magnetic ink with which the record method which uses a magnetic fluid is presented. A magnetic fluid is a fluid in which the magnetic particle of particle diameter abbreviation 50~200A was suspended in carrier fluid with the surface-active agent, and it has the characteristic of causing neither sedimentation nor condensation by stability for a long period of time. The above-mentioned magnetic particle is magnetite (FeO-Fe).₂O₃Iron zinc ferrite (Fe)_aZn₍₁-_a)O-Fe₂O₃And a manganese zinc ferrite (Mn)_bZn₍₁-_b)O-Fe₂O₃etc. -- the magnetic body particulates containing phyllite are offered. As a surface-active agent, oleic acid, the carboxylic acid of linoleic acid, a cation system active agent, a Nonion system active agent, etc. are independent, or are used by a compound system, for example. As carrier fluid, carboxylic acid, such as oleic acid and linoleic acid, a cation system active agent, a Nonion system active agent, etc. are independent, or are used by a compound system, for example. As carrier fluid, paraffine, ester oil, fluoridation hydrocarbon, etc. are offered, for example. The following magnetic fluid recording methods are the methods of recording by using the above-mentioned magnetic fluid as the ink for record, and making magnetic ink fly or migrate by magnetic or electric power. As for the magnetic ink for record conventionally used for a field at this rate, remaining as it is, or diluting by carrier fluid, and using was proposed in the magnetic fluid. As for the above-mentioned magnetic ink, the fault of hue not changing or not maintaining hue stably when it is recorded on a record object, a thin layer and Summer, and a recording form are permeated and record is formed, although it is usually assuming black or black, and a color is Oh. This cause is considered as follows. When ink flies or migrates on recording media, such as a record object and a recording form, there are very few magnetic particles in a record image. Generally in the particle diameter of the magnetic particle used for a magnetic fluid, it is hard to absorb red light. For this reason, the hue of the ink on a recording medium is tinged with red compared with the hue of the ink before record, and assumes black and a color thru/or brown. When the conventional magnetic ink for record is used, a fault recordable only by the color of a magnetic particle is Oh. The present invention conquers the conventional fault and an object of the present invention is to provide the abundant magnetic ink for record of hue. The magnetic ink for record of the present invention made the carrier fluid which consists of charcoal-fire hydrogen, ether, or fluoridation hydrocarbon distribute a magnetic particle with a surface-active agent, and added the colorant which carried out solubilization processing like the after-mentioned, or good decentralization processing. The following three points are mentioned in general to the item demanded as magnetic ink for record. Colorant should be distributing to the dissolution or stability in the carrier fluid of a magnetic fluid. Colorant should not affect the dispersion stability of a magnetic particle. The magnetic ink for record should answer to a record signal including colorant. However, if above-mentioned one is satisfied, it will be satisfied generally and simultaneous. Now, in order to satisfy the above-mentioned request of three points, it processes so that solubilization processing, i.e., colorant, may carry out molecular dispersion of the colorant to the carrier fluid of a magnetic particle, or it processes so that good decentralization processing, i.e., colorant, may carry out particle distribution at carrier fluid (these are called processing below). This processing dissolves or distributes the above-mentioned colorant to the carrier fluid of a magnetic fluid. It is required for there not to be a solubilization processing agent or a good decentralization processing agent (below, both are combined and are called a processing agent) about an interaction to the surface-active agent of a magnetic fluid in Exterior. As a processing agent, it is the saturation or the unsaturated hydrocarbon compound of carbon number 10~30 of a main chain with the carrier fluid of a magnetic fluid, and compatibility, and uses the compound which has a Ability machine which is affinitive or unitable to colorant. For example, they are carboxylic acid or sulfonic acid, those acid anhydrides, Carboxy chloride, a Carboxy star's picture, Sulfone chloride, etc. Although colorant changes with the molecular extinction coefficient or concealment rates, the range of colorant of about 10~100 weight sections is preferred to 100 weight sections of magnetic particles. If and there is little magnetic property of magnetic ink when more than this range, change of hue will decrease. [ disadvantage ] Now, as for the above-mentioned processing, the following two methods are raised roughly. One has the method of making the above-mentioned processing agent sticking to colorant, and the way others combine colorant and the above-mentioned processing agent. The method of combining colorant and a processing agent, and the method of combining a colorant intermediate and a processing agent are one of the latter methods by pretreating beforehand to colorant further. On the other hand, although oil soluble dyestuff is also marketed, the solubility to the carrier fluid of the oil soluble dyestuff which can generally be obtained is low. For this reason, by the time it changes the hue of ink, it will not result. Therefore, when Then also processes above-mentioned either by oil soluble dyestuff, it is necessary to solubilize or good decentralize. There is no clear distinction in solubilization and good decentralization. The hue of the magnetic ink for record was able to be changed by mixing with a magnetic fluid the colorant which performed the above processings at a suitable rate. However, the Ability machine of a processing agent mentioned above has polarity. For this reason, if a processing agent is superfluously added in processing of colorant, a superfluous processing agent will form the processing agent and reversed micelle which were adsorbed or combined with the surface-active agent or colorant of the magnetic fluid, and will reduce the dispersion stability of the magnetic ink for record. Therefore, in processing of colorant, only the amount of adsorption or coupling amount of colorant needs to add a processing agent. Although the magnetic ink for record obtained as mentioned above was neglected several months, change of separation of a magnetic particle or colorant, condensation, precipitation, etc. was not seen. Next, the material used for the present invention is explained. However, the material described below is a mere example and, of course, it is not what gives limitation to the present invention. As the inside of colorant, and dye, it is a basic stain of C.I.BasicRed9 and C.I.Basic Blue 24 grade first, for example, C. I.Acid BIue 43, acid dye of 78C.I.Acid Violet41 grade, C. Oil soluble dyestuff of azoic dye of I.Azoic Diazo Component31, 34, and 35 grades and C.I.Solvent Yellow 6, 61, and 80, C.I.SolventOrange2, and 37 grades is raised. As paints, C.I.Pigment Yellow5, 11, 15, C.I.Pigment Red 50, 51, and 53, C.I.Pigment Blue1, and 2 grades are raised. In addition, for example, in acetylation of dye of C.I.Acid Red32, 35, and 37 grades, the dye to which the carboxylic acid processing agent described below was made to react is also raised. In Oil solubilization of oil soluble dyestuff, the dye which introduced a long-chain hydrocarbon chain which is described below is also mentioned. Now, as a processing agent, generally long-chain carboxylic acid or sulfonic acid of hydrocarbon, etc. is mentioned, and 10~30 has a preferred carbon number of a main chain. Next, about processing, an ionic bond besides covalent bonds, such as acetylation and Ethyl-izing, etc. is mentioned, for example. Adsorption by the polar group of colorant and the polar group of a processing agent is also mentioned. The methods of a pretreatment of colorant include amination of colorant, hydro-oxyl-ization, etc., for example. The disposal method and pretreatment method which were described above are a mere example, and, of course, it is not what adds a certain limitation to the present invention. There are the following effects in the magnetic ink for record of the present invention. It is effective in changing the hue of the magnetic ink for record freely first. The carrier fluid of the magnetic ink for record of the present invention is what is called oily carrier fluid called hydrocarbon, ether, or fluoridation hydrocarbon. When a surface-active agent encloses a magnetic particle further, the magnetic particle is distributing the magnetic fluid using oily carrier fluid. On the other hand, in the magnetic fluid using basin system carrier fluid, when a surface-active agent forms reversed micelle, a magnetic particle distributes. Generally, since reversed micelle is unstable, the magnetic fluid using oily carrier fluid is stable compared with the magnetic fluid which used basin system carrier fluid. Therefore, distribution of the magnetic particle of the magnetic ink for record of the present invention is stable. The magnetic ink for record of the present invention contains the colorant by which solubilization processing or good decentralization processing was carried out by adsorbing or combining a processing agent with colorant. For this reason, the dispersion stability of ink is the same as the magnetic fluid which does not contain colorant. Therefore, even if it neglects the magnetic ink for record of the present invention in respect of ink maintenance for a long period of time, it is effective in ink composition, hue, and an electric magnetic property being maintained. If it processes to colorant or the colorant intermediate which pretreated beforehand, a processing agent will be certainly combined with colorant. Therefore, a processing agent is isolated from colorant and does not reduce the dispersibility or solubility of a magnetic particle or colorant. Therefore, by processing to colorant or the colorant intermediate which pretreated, magnetization of the magnetic ink for record is high. Therefore, the quick ink of the response to a magnetic field is obtained. By using the magnetic ink for record of the present invention, conventionally, only in one color, record which has various hue can be realized, and this can be conventionally solved also about faults, such as a variation per hour of Oh hue, on a problem, and record with high practicality can be provided in Oh magnetic ink record. A concrete example is described below. First, the method of processing colorant is listed to below. A: the Mihara oil blue (the Mihara chemically-modified -- Co., Ltd.) and oleic acid of colorant were mixed at a rate of weight ratio 1:3.2. B:3 -- Mol's [ amino group / the ] Oilein acid was added to ―Through (N ―ethyl―Anilide)-1 ―Aniline― 4 ―Azo― 2 ―amino― 8 ―Nahu true 6 ―Sulfone acid sodium, and it heated to 180 degreeC. C: 300 g of glacial acetic acid, mercury acetate ()5g, C.I. basic green 4 330 g and 92wt% of nitric acid [ 53 ml of ] were mixed, and it was made 60 degreeC, and nitrated. Sodium sulfide 84g, sulfur 42g, 75 g of water oxidization Natrium, and 840 ml of 95% ethanol were mixed to this nitrated colorant 330g, it was refluxed for 3 hours, and it aminated. In this way, linoleic acid twice the number of Mol of the amino group was added to the aminated colorant, and it heated to 150 degreeC. D: Mol's [ amino group / the ] linoleic acid was mixed in C.I. basic blue 24, and it heated to 140 degreeC. E: 110 g of oleic acid, polyphosphoric acid 100g, and 500 ml of benzene were added to 630 g of C.I. reed dreadlocks 88, and by 90 degreeC, it was made to react for 24 hours and etherified. F: Mol's [ amino group / the ] oleic acid was mixed to C.I. Piganto Yellow 5. The Matsumoto Yushi-Seiyaku magnetic fluid which showed the colorant which processed more than in the 1st table was mixed. Each carrier fluid of the magnetic fluid used here is kerosene, and the concentration of a magnetic particle is 20vo%. Composition of a magnetic particle is an analytical value at the time of particle manufacture.

[Table]

It was made to fly in the record paper with the magnetic fluid recorder which was mixed at a rate as showed above-mentioned colorant A~F and magnetic fluid G~I in the 2nd table, built the magnetic ink for record, and was shown in Drawings 1 and 2. The hue at this time was shown in the 2nd table.

[Table]

If a magnetic fluid recorder is explained briefly here, as shown in Drawing 1, let composition which contacted one end of stylus 1 to magnet 2, and made the other end of stylus 1 counter electrode 4 via recording form 3 be the principal part. At this time, magnetic ink 5 upheaves at the tip of Along the street by the magnetic field of magnet 2 at stylus 1. Next, if voltage 7 (record voltage) corresponding to an image signal is applied between stylus 1 and electrode 4 as shown in Drawing 2, magnetic ink 5 will fly according to coulomb force from the tip of upheaval 6. Thus, record according to an image signal on recording form 3 can be performed. When the above-mentioned magnetic ink for record was neglected several months and inspected, separation, condensation, precipitation, etc. were not seen by the magnetic particle or colorant in ink. Change of It was done is inside Ivy also to the hue of ink about the experiment recorded with a magnetic fluid recorder like the account of neglect back to front several months. The effect as the above-mentioned that the magnetic fluid of ether or a fluoridation carbon system also had the same carrier fluid was acquired. Even if it used sulfonic acid for the processing agent, the same effect as the above-mentioned was acquired. It is very easy to treat the present invention by having included colorant which processed [ solubilization-] or processed [ good-decentralization-] in a magnetic fluid as mentioned above, without being able to realize ink which presents various hue and the recording characteristic and record quality also changing in any way with the conventional thing. A variation per hour of hue, deterioration, etc. are not seen, but outstanding magnetic ink for record which can use especially for a magnetic fluid recorder and can obtain multicolor and stable record can be provided.

[Brief Description of the Drawings]

The section side view showing the principle of the magnetic fluid recorder with which Drawing 1 uses the magnetic ink for record of the present invention, and Drawing 2 are side views showing a record state. 1 ...... stylus, 2 ...... magnet, 3 ...... recording form, 4 ...... electrode, 5 ...... magnetic ink, 7 ...... voltage.