JP2006046937A - Liquid dispersant for preparing magnetic powder liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid dispersant for preparing a magnetic powder liquid that is low in initial viscosity, that causes no gelation or solidification during preservation, or much compounding amount of effective components and reduced in the compounding amount of water. <P>SOLUTION: A tertiary butylbenzoate is formulated with the liquid dispersant for preparing the magnetic powder liquid composed of a nonionic surfactant with an HLB of 8-14, a silicone-defoaming agent, a higher fatty acid, an alcohol and water in an amount of 0-25 wt.%, the compounding ratio of the surfactant is set at least to 8 wt.% and the compounding ratio of water is set to 45-65 wt.% to adjust the viscosity of the liquid dispersant for the magnetic powder liquid to 15-65 cP. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid dispersant for preparing a magnetic powder solution suitable for preparing a magnetic powder solution used in a wet magnetic particle testing method.

  As is well known, steel materials such as square billets and round billets are used as inspection objects in steel manufacturing plants, and steel parts such as knuckle arms and shafts are used as inspection objects in automobile manufacturing plants. For the flaw detection, “wet magnetic particle flaw detection test method” standardized in JIS G 0565-1992 “ferromagnetic particle flaw detection test method and classification of magnetic powder pattern” is widely used.

  The wet magnetic particle testing method is usually carried out by bringing a magnetic powder liquid in which 0.2 to 2.0 g of fluorescent magnetic powder or non-fluorescent magnetic powder per 1 liter of water is dispersed into contact with the surface of the test object. In the preparation of the liquid, a dispersant for preparing a magnetic powder liquid in which a surfactant is blended is always used.

  Currently, a typical formulation of a liquid dispersant for preparing a magnetic powder solution is a polyoxyethylene alkyl ether type nonionic surfactant having a HLB in the range of 8 to 14 in 70 to 98% by weight of water, polyoxy Selected from ethylene alkyl allyl ether type nonionic surfactant, polyoxyethylene alkyl ester type nonionic surfactant, polyoxyethylene alkylamine type nonionic surfactant and polyoxyethylene sorbitan fatty acid ester type nonionic surfactant One or two or more nonionic surfactants in which 2 to 30% by weight are dissolved or dispersed are used as a basic prescription, and sodium nitrite, triethanolamine, etc. for the purpose of imparting a rust-proofing effect on the object to be inspected (steel) An appropriate amount of commercially available rust preventive is blended, and usually the magnetic powder liquid on the surface of the object to be inspected In adhering, the magnetic powder is agitated in the tank and transported to a predetermined spraying place by a pump and sprayed on the surface of the object to be inspected. The sprayed magnetic powder is collected in the tank, and the collected magnetic powder is collected. Since the liquid is again circulated from the tank to the spraying place by the pump and sprayed, the magnetic powder in use is in a state where it is easily foamed. Since the foam overflows more, silicon antifoaming agent KS530 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) and silicon antifoaming agent KM-75 (trade name, Shin-Etsu Chemical Co., Ltd.) are provided for the purpose of imparting an antifoaming effect to the magnetic powder liquid. An appropriate amount of a commercially available silicone antifoaming agent such as

  In addition, in the prescription with which the said rust preventive agent and / or antifoamer were mix | blended, the quantity of water corresponding to the compounding quantity is reduced.

  In addition, various improved formulations of liquid dispersants for preparing magnetic powder solutions have been proposed. Patent Document 1 listed below includes water, nonionic surfactants, silicone antifoaming agents, rust preventives and soaps (higher fatty acids). The following formulation is also disclosed in Patent Document 2 described below, which is composed of water, a nonionic surfactant, a silicone antifoaming agent, soap and alcohol.

  In addition, the prescription disclosed in the following Patent Document 1 is a mixture of soap for the purpose of obtaining a stronger antifoaming effect in addition to the antifoaming effect of the silicone antifoaming agent. When the liquid temperature is room temperature (20 to 30 ° C.), a practically sufficient antifoaming effect can be obtained by adding the silicone antifoaming agent alone, whereas when the liquid temperature exceeds 40 ° C., the silicone antifoaming agent alone is obtained. In this case, the defoaming effect cannot be obtained, but practically sufficient defoaming effect can be obtained even when the liquid temperature is 40 to 50 ° C. by using soap together. In addition, the prescription disclosed in Patent Document 2 mentioned later has a high Kraft point for higher fatty acids such as soap, so the liquid dispersant for preparing magnetic powder containing soap is likely to have a high viscosity, especially during storage. Since viscosity increases easily, alcohol is blended for the purpose of suppressing viscosity increase during storage, and in the case of a prescription without blending alcohol, it becomes a pudding after 3 months from the time of manufacture. However, in the case of a prescription blended with alcohol, it remains liquid even after 12 months from the time of manufacture.

  For example, the commercially available liquid dispersant for preparing magnetic powder liquid and the liquid dispersant for preparing magnetic powder liquid disclosed in Patent Documents 1 and 2 described below each include 0.2 to 2.0 g of fluorescent magnetic powder per liter of water. When preparing a dispersed magnetic powder, it is used by adding so that the concentration of the liquid dispersant for preparing the magnetic powder per 1 liter of water is 1 to 3%. This achieves a dispersibility capable of sufficiently dispersing 0.2 to 2.0 g of fluorescent magnetic powder per liter of water, and the surface is uniform when the magnetic powder liquid is brought into contact with the surface of the object to be inspected. In order to obtain wettability that can be wet, it is necessary that at least the concentration of the liquid dispersant for preparing magnetic powder solution per liter of water is 1% or more, while the liquid for preparing magnetic powder solution per liter of water. This is because no significant improvement in dispersibility and wettability is observed even when the dispersant concentration is 3% or more.

Japanese Examined Patent Publication No. 2-52987: Japanese Examined Patent Publication No. 4-26057:

  First, the first technical problem to be solved by the present invention is as follows.

  That is, in preparing a magnetic powder using a liquid dispersant for preparing a magnetic powder, a commonly employed embodiment is that a predetermined amount of a liquid dispersant and a predetermined amount of fluorescent magnetic powder are first mixed well to form a liquid. Then, the mixture is poured into a predetermined amount of water and stirred to obtain a required magnetic powder solution. This mode is adopted because the liquid dispersant is used as a fluorescent magnetic powder. This is because the performance of the dispersant can be sufficiently exerted by adhering to one grain.

  However, when the viscosity of the liquid dispersant for preparing the magnetic powder liquid is high, it becomes a dumpling when the predetermined amount of the liquid dispersant and the predetermined amount of the fluorescent magnetic powder are mixed. It becomes difficult to adhere to each grain, and workability is also significantly deteriorated.

  The initial viscosity of the liquid dispersant for preparing magnetic powder liquid increases in proportion to the amount of higher fatty acid compounded in the formulation, and as the blending amount increases, it will gel or solidify over time. In addition, even when a higher fatty acid in an amount that does not gel or solidify in water is added, if a nonionic surfactant or rust preventive agent is blended, the dissolving power decreases and the viscosity increases, causing gelation or solidification. It will cause.

However, even when a higher fatty acid is blended in the formulation, the initial viscosity can be lowered by reducing the blending amount of the nonionic surfactant (in Patent Documents 1 and 2, the nonionic surfactant). 2-6%).
However, when preparing a magnetic powder solution, when using a liquid dispersant for preparing a magnetic powder solution with a small (low) amount (concentration) of the nonionic surfactant, a large amount (concentration) of the nonionic surfactant is used. Compared with the case of using (high) a liquid dispersant for magnetic powder solution preparation, the amount of use increases, and the “problem of product bulk and weight” described later occurs.

  Therefore, the present invention provides the initial viscosity (viscosity at the time of manufacture) of the liquid dispersant for preparing magnetic powder liquid in which soap (higher fatty acid) is blended in the formulations disclosed in Patent Documents 1 and 2, and the nonionic surfactant. A first technical problem is to provide a liquid dispersant for preparing a magnetic powder solution that can be reduced as much as possible without reducing the blending amount of the agent and cause gelation or solidification.

  Next, the second technical problem to be solved by the present invention is as follows.

  That is, each said nonionic interface in which HLB currently used for the liquid dispersing agent for the above-mentioned commercial magnetic powder liquid preparation and the liquid dispersing agent for the magnetic powder liquid preparation currently disclosed by patent documents 1 and 2 exists in the range of 8-14. The activator is liquid and very difficult to dissolve or disperse in water. Specifically, when trying to dilute a certain amount of HLB 8-14 nonionic surfactant (liquid) dissolved or dispersed in a certain amount of water, it is constant to a certain amount (for example, 2 g) of the active agent. When an amount of water (for example, 98 cc) is injected at a time, it will be in a gel state no matter how much it is stirred, and the viscosity will not decrease indefinitely, while a certain amount (for example, 98 cc) of a certain amount (for example, 2 g) of the active agent. ) When added in small amounts (for example, 10 cc) with stirring, the viscosity initially increases to a milky white dispersion or jelly, but after a certain point, the viscosity decreases and becomes translucent. It becomes a dispersion or a transparent solution. When the HLB number of the activator is low, it becomes milky white dispersion liquid, and when the HLB number is high, it becomes jelly. Accordingly, it is almost impossible to prepare a liquid dispersant for preparing a magnetic powder by dissolving or dispersing a nonionic surfactant of HLB 8 to 14 in water at the implementation site of the wet magnetic particle testing method. The manufacturer of the liquid dispersant for liquid preparation prepares a clear solution or a translucent dispersion in advance, and fills it into an 18-liter can (petroleum can) (tared weight: about 20 kg). The bulk and weight are a problem during transportation and transportation (by the way, delivery to the user's steel material manufacturing factory and automobile manufacturing factory is performed in units of 50 to 60 18 liter cans at a time. Is the current situation).

  Therefore, the present invention provides the blending amount (concentration) of the nonionic surfactant blended in the liquid dispersant for preparing magnetic powder liquid in which soap (higher fatty acid) is blended in the formulations disclosed in Patent Documents 1 and 2. A liquid dispersant for magnetic powder preparation that increases (higher) as much as possible, in other words, reduces the amount of water in the formulation as much as possible, and has a smaller product volume and weight than conventional products. Providing the above is a second technical problem.

  In order to achieve each of the technical problems described above, the present inventor can reduce the initial viscosity of a liquid dispersant for preparing magnetic powder liquid in which a higher fatty acid is blended in the formulation, and can suppress the occurrence of gelation or solidification. As a result of repeated trial and error trials and experiments on many substances in search of additives, when adding tertiary butyl benzoate, the initial viscosity due to higher fatty acids in the formulation is reduced and gelled. In addition, new knowledge that can suppress the occurrence of solidification has been obtained, and tertiary butyl benzoate itself has an excellent anti-rust effect on the test object (steel), so sodium nitrite and Blending of commercially available rust preventives such as ethanolamine can be omitted, and the problem was achieved by blending more nonionic surfactant in an amount commensurate with the blended amount.

  Each of the above technical problems can be solved by the present invention as follows.

  That is, the present invention blends tertiary butyl benzoate with a liquid dispersant for magnetic powder preparation consisting of a nonionic surfactant, silicone antifoaming agent, higher fatty acid, alcohol and water within the range of HLB 8-14. It is a liquid dispersant (Invention 1) for preparing magnetic powder liquid, characterized in that the viscosity is in the range of 15 cP to 65 cP.

  The present invention is also the liquid dispersant for preparing a magnetic powder liquid according to the first aspect, wherein the tertiary butyl benzoate is a sodium salt or a potassium salt (invention 2).

  In the invention 1 or 2, the present invention has a nonionic surfactant content of at least 8% by weight and a water content of 45 to 65% by weight within the range of HLB 8-14. The liquid dispersant for preparing magnetic powder liquid (Invention 3), wherein the blending ratio of tertiary butyl benzoate is 10 to 25% by weight.

  The configuration of the present invention will be described in more detail as follows.

  First, as the nonionic surfactant, silicone antifoaming agent, higher fatty acid and alcohol in the range of HLB 8 to 14 used in the present invention, all of the above-mentioned liquid dispersant for preparing magnetic powder liquid and Patent Document 1 and What is necessary is just to use what is used for the liquid dispersing agent for magnetic-powder liquid preparation currently disclosed by 2. FIG.

  The nonionic surfactant within the HLB range is preferably polyoxyethylene lauryl ether (HLB10.5), and the silicone antifoaming agent KS530, silicon antifoaming agent KS531, and silicon antifoaming are preferred. Agent KS537 (both trade names, manufactured by Shin-Etsu Chemical Co., Ltd.) are preferable, and higher fatty acids include soap (for example, NS soap, trade name, manufactured by Kao Corporation, sodium beef fatty acid), potassium palmitate, sodium myristate The alcohol is preferably propylene glycol, isopropyl alcohol, or ethanol. Tap water may be used as the water.

  The tertiary butyl benzoate used in the present invention may be either its sodium salt or potassium salt.

  Next, the blending ratio of the various materials used in the present invention is required to blend at least 8% by weight of the nonionic surfactant in the range of HLB 8 to 14 and the blending ratio of water to 45 to 65% by weight. This is to reduce the amount used during use and to reduce the bulk and weight of the product. In addition, although the upper limit of the mixing ratio of the nonionic surfactant depends on the mixing ratio of tertiary butyl benzoate, it is usually about 25% by weight.

  The blending ratio of the silicone antifoaming agent is preferably 3 to 6% by weight, and if it is less than 3% by weight, it is difficult to obtain the required defoaming effect, and since higher fatty acids are used in combination, it is necessary to blend more than 6% by weight. Absent.

  The blending ratio of the higher fatty acid is preferably 5 to 15% by weight, and if it is less than 5% by weight, it is difficult to obtain an antifoaming effect when the temperature of the magnetic powder is about 40 ° C. or higher. However, no improvement in the defoaming effect is observed.

  If the blending ratio of the alcohol is about 5% by weight, the viscosity increase during storage can be sufficiently suppressed.

  The blending ratio of tertiary butyl benzoic acid is preferably 10 to 25% by weight, and if it is less than 10% by weight, it is difficult to obtain the effect of reducing the initial viscosity and suppressing the occurrence of gelation or solidification. However, the improvement of the effect is not recognized.

  Next, the structure of the liquid dispersant for preparing a magnetic powder solution according to the present invention is very easy, and each of the materials other than the silicone antifoaming agent is weighed for each of the required amounts within the ranges of the mixing ratios. The material is put into a tank, stirred while the liquid temperature is heated to about 60 ° C., then cooled to about 25 ° C., and then a silicone antifoaming agent is put into the tank and stirred again so that milky white A liquid object exhibiting the following can be obtained.

  The initial viscosity measured using the vibration viscometer of the target product thus obtained is in the range of 15 cP to 65 cP, and the predetermined amount of liquid dispersant and the predetermined amount of fluorescence in the above-described embodiment of the magnetic powder liquid preparation are used. The operation | work which mixes with magnetic powder and is made into a liquid mixture can be performed easily and efficiently. Further, even when 12 months have passed since the production, the viscosity is hardly increased and the liquid state is maintained and gelation or solidification does not occur.

  According to the present invention, the initial viscosity is low despite the inclusion of higher fatty acids in the formulation, the viscosity does not increase during storage, so gelation and solidification do not occur, and the nonionic interface in the formulation A liquid dispersant for preparing a magnetic powder can be provided in which the amount of the active agent is large and the amount of water is small.

  1000g of polyoxyethylene lauryl ether (HLB10.5), NS soap (trade name, manufactured by Kao Corporation, beef fatty acid sodium) 500g, propylene glycol 500g, tertiary butyl sodium benzoate 2500g and tap water 5000g are put into a stainless steel tank. Then, the tank is heated and sufficiently stirred using an electric mixer with the liquid temperature in the tank heated to 60 ° C., then the heating is stopped, the liquid temperature is cooled to 25 ° C., and then the silicon defoaming is performed. About 10000 g of the liquid dispersant for preparing a magnetic powder liquid (present product A) was obtained by adding 500 g of the agent KS530 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) to the tank and stirring sufficiently. The viscosity of the product A of the present invention obtained here was 18.2 cP when measured using a vibration viscometer (VISCOMATE VM1-A, trade name, manufactured by Yamaichi Electronics Co., Ltd.). The product A of the present invention remained in a liquid state even when 12 months had elapsed from the time of manufacture, and neither gelation nor solidification occurred.

  After adding 10 g of Super Magna fluorescent magnetic powder LY-1500 (trade name, manufactured by Marktec Co., Ltd.) to 50 ml of the product A of the present invention and stirring and dispersing the mixture, the dispersion is added to 10 l of tap water and stirred. A was prepared.

  Performance comparison test: For comparison, after adding 10 g of Super Magna Fluorescent Magnetic Powder LY-1500 (same as above) to 200 ml of Super Magna Magnetic Powder Dispersant (trade name, manufactured by Marktech Co., Ltd., Liquid), and stirring and dispersing it Then, a magnetic powder solution for comparison was prepared by adding the dispersion to 10 l of tap water and stirring.

  The dispersion state of the fluorescent magnetic powder in the magnetic powder liquid A prepared here was equivalent to the dispersion state of the fluorescent magnetic powder in the comparative magnetic powder liquid, and the redispersibility after being left for 24 hours was also equivalent.

  Next, using the magnetic powder A prepared here and the comparative magnetic powder, the following wet magnetic particle testing method was carried out.

  Using a steel square billet to which the above-mentioned JIS standard A-type standard test piece (circular / Al-15 / 100) is attached, this is magnetized by the axial current method, and magnetic powder A and comparative magnetic powder are obtained. In each of the above-described modes of repeating the spraying / recovery / spreading cycle, the sample is sprayed on the surface of the test piece, and then irradiated with an ultraviolet lamp in a dark place and visually observed.

  As a result, it was confirmed that both magnetic powders can observe the same clear defect indication pattern. Moreover, generation | occurrence | production of rust was not recognized by the steel square billet, but it has confirmed that both magnetic powder liquid had the same rust prevention effect. In addition, although it circulated in the state which heated the liquid temperature of the magnetic powder liquid A to about 40 degreeC, foaming did not occur.

  Examples of the present invention and comparative examples are given below.

  Example 1: 1000 g of polyoxyethylene styrenated phenyl ether (HLB10.6), 500 g of potassium palmitate, 600 g of ethanol, 1000 g of sodium tertiary butylbenzoate and 6500 g of tap water were put into a stainless steel tank, and the tank was heated. After sufficiently stirring with an electric mixer while the liquid temperature in the tank is heated to 60 ° C., the heating is stopped, the liquid temperature is cooled to 25 ° C., and then the silicone antifoaming agent KS531 (trade name: Shin-Etsu Chemical) 400 g of Co., Ltd. was put into the tank and stirred sufficiently to obtain about 10000 g of a liquid dispersing agent for preparing a magnetic powder solution (present product B). The viscosity of the product B of the present invention obtained here was 40.2 cP when measured using a vibration viscometer (VISCOMATE VM1-A, trade name, manufactured by Yamaichi Electronics Co., Ltd.). The product B of the present invention was kept in a liquid state even after 12 months from the production, and neither gelation nor solidification occurred.

  After adding 10 g of Super Magna fluorescent magnetic powder LY-1500 (trade name, manufactured by Marktec Co., Ltd.) to 50 ml of the product B of the present invention and stirring and dispersing the mixture, the dispersion is added to 10 l of tap water and stirred. B was prepared.

  Example 2: 800 g of polyoxyethylene styrenated phenyl ether (HLB10.6), 1500 g of sodium myristate, 600 g of propylene glycol, 1500 g of tertiary butyl benzoate and 5100 g of tap water are put into a stainless steel tank, and the tank is heated. Then, after sufficiently stirring with an electric mixer while the liquid temperature in the tank is heated to 60 ° C., the heating is stopped, the liquid temperature is cooled to 25 ° C., and then the silicone antifoaming agent KS537 (trade name, Shin-Etsu) Chemical Co., Ltd.) (500 g) was put into the tank and stirred sufficiently to obtain about 10000 g of a liquid dispersing agent for preparing a magnetic powder liquid (present product C). The viscosity of the product C of the present invention obtained here was 62.8 cP when measured using a vibration viscometer (VISCOMATE VM1-A, trade name, manufactured by Yamaichi Electronics Co., Ltd.). The product C of the present invention was kept in a liquid state even after 12 months from the time of manufacture, and neither gelation nor solidification occurred.

  After adding 10 g of Super Magna fluorescent magnetic powder LY-1500 (trade name, manufactured by Marktec Co., Ltd.) to 50 ml of the product C of the present invention and stirring and dispersing it, the dispersion is added to 10 l of tap water to stir the magnetic powder. C was prepared.

  Example 3: 1000 g of polyoxyethylene lauryl ether (HLB10.5), 1500 g of sodium myristate, 500 g of propylene glycol, 2000 g of tertiary butyl benzoate and 4500 g of tap water were put into a stainless steel tank, and the tank was heated. After sufficiently stirring with an electric mixer while the liquid temperature in the tank is heated to 60 ° C., the heating is stopped, the liquid temperature is cooled to 25 ° C., and then the silicone antifoaming agent KS537 (trade name: Shin-Etsu Chemical Co., Ltd.) About 10,000 g of liquid dispersant for preparing a magnetic powder solution (invention product D) was obtained by putting 500 g into the tank and stirring sufficiently. The viscosity of the product D of the present invention obtained here was 28.7 cP when measured using a vibration viscometer (VISCOMATE VM1-A, trade name, manufactured by Yamaichi Electronics Co., Ltd.). The product D of the present invention was kept in a liquid state even after 12 months from the time of manufacture, and neither gelation nor solidification occurred.

  After adding 10 g of Super Magna magnetic powder dispersant (trade name, manufactured by Marktec Co., Ltd.) to 50 ml of the product D of the present invention, and stirring and dispersing the mixture, the dispersion is added to 10 l of tap water to stir the magnetic powder D. Prepared.

Example 4: 2000 g of polyoxyethylene isodecyl ether (HLB10.5), NS soap (trade name, manufactured by Kao Corporation, sodium beef fatty acid) 500 g, ethanol 500 g, tertiary butyl potassium benzoate 1000 g and tap water 5500 g were stainless steel The tank is heated, and the tank is heated to sufficiently stir the liquid temperature in the tank to 60 ° C. using an electric mixer, then the heating is stopped, the liquid temperature is cooled to 25 ° C., and then 500 g of a silicon antifoaming agent KS530 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) was put into the tank and sufficiently stirred to obtain about 10000 g of a liquid dispersing agent for preparing magnetic powder liquid (present product E) exhibiting milky white color. The viscosity of the product E of the present invention obtained here was measured using a vibration viscometer (VISCOMATE).
It was 41.0 cP when measured using VM1-A (trade name, manufactured by Yamaichi Electronics Co., Ltd.). The product E of the present invention remained in a liquid state even when 12 months had elapsed from the time of manufacture, and neither gelation nor solidification occurred.

  After adding 10 g of Super Magna magnetic powder dispersant (trade name, manufactured by Marktec Co., Ltd.) to 50 ml of the product E of the present invention and stirring and dispersing the mixture, the dispersion is added to 10 l of tap water to stir the magnetic powder E. Prepared.

  Performance comparison test: The dispersion state of the fluorescent magnetic powder in the comparative magnetic powder prepared in the above-mentioned “Best Mode for Carrying Out the Invention” and the magnetic powder B and magnetic powder prepared in Examples 1 to 4, respectively. The dispersion states of the fluorescent magnetic powder liquids in C, magnetic powder liquid D, and magnetic powder liquid E were the same, and the redispersibility after being left for 24 hours was also the same.

  Moreover, as a result of carrying out the wet magnetic particle flaw detection test method performed in the above-mentioned "Mode for carrying out the invention" using the magnetic powder solution B, the magnetic powder solution C, the magnetic powder solution D, and the magnetic powder solution E, each magnetic powder solution B to E can confirm that a clear defect indicating pattern equivalent to the case where the test method is carried out using the magnetic powder for comparison can be observed, and the occurrence of rust is not recognized in the steel square billet, It was confirmed that each of the magnetic powder liquids B to E had the same rust prevention effect as that of the comparative magnetic powder liquid. In addition, although the magnetic powder liquids B to E were circulated in a state where the liquid temperature was heated to about 40 ° C., foaming did not occur.

  Comparative Example 1: Among the conditions for obtaining the product A of the present invention in the above-mentioned column “Best Mode for Carrying Out the Invention”, except that tertiary butyl sodium benzoate was not blended and the tap water was 7500 g, What was obtained when the same conditions as those for obtaining the product A of the present invention were obtained was a gel-like product exhibiting a milky white color. Vibrating viscometer (VISCOMATE VM1-A, trade name, manufactured by Yamaichi Electronics Co., Ltd.) Viscosity measurement by was impossible.

  Comparative Example 2: Among the conditions for obtaining the product A of the present invention in the above-mentioned “Best Mode for Carrying Out the Invention”, except that 2500 g of sodium nitrite was used instead of sodium tertiary butylbenzoate, What was obtained when the same conditions as those for obtaining the product A of the present invention were obtained was a white solid, and viscosity measurement was impossible.

  Comparative Example 3: Among the conditions for obtaining the product A of the present invention in the above-mentioned “Best Mode for Carrying Out the Invention”, except that 2500 g of triethanolamine was used instead of sodium tertiary butylbenzoate, What was obtained when the same conditions as those for obtaining the product A of the present invention were obtained was a white solid, and viscosity measurement was impossible.

  Comparative Example 4: Among the conditions for obtaining the product B of the present invention in Example 1, the same conditions as those for obtaining the product B of the present invention were obtained except that the amount of tap water was changed to 7500 g without adding tertiary butyl benzoate. What was obtained in this case was a gel-like product having a milky white color, and it was impossible to measure the viscosity with a vibrating viscometer (VISCOMATE VM1-A, trade name, manufactured by Yamaichi Electronics Co., Ltd.).

  Comparative Example 5: Among the conditions for obtaining the product B of the invention in Example 1, except that 1000 g of sodium nitrite was used instead of sodium tertiary butylbenzoate, the same conditions as those for obtaining the product B of the invention were obtained. In this case, what was obtained was a white solid, and viscosity measurement was impossible.

  Comparative Example 6: Among the conditions for obtaining the product B of the present invention in Example 1, except that 1000 g of triethanolamine was used instead of sodium tertiary butylbenzoate, the same conditions as those for obtaining the product B of the present invention were used. In this case, what was obtained was a white solid, and viscosity measurement was impossible.

  Comparative Example 7: Among the conditions for obtaining the product C of the present invention in Example 2, the same conditions as those for obtaining the product C of the present invention were obtained except that 6500 g of tap water was used without adding tertiary butyl benzoate. What was obtained in this case was a cream-like product having a white color, and viscosity measurement with a vibration viscometer (VISCOMATE VM1-A, trade name, manufactured by Yamaichi Electronics Co., Ltd.) was impossible.

  Comparative Example 8: Among the conditions for obtaining the product C of the present invention in Example 2, except that 1500 g of sodium nitrite was used instead of sodium tertiary butylbenzoate, the same conditions as those for obtaining the product C of the present invention were used. In this case, what was obtained was a white solid, and viscosity measurement was impossible.

  Comparative Example 9: Among the conditions for obtaining the product C of the present invention in Example 2, except that 1500 g of triethanolamine was used instead of sodium tertiary butylbenzoate, the same conditions as those for obtaining the product C of the present invention were used. What was obtained in this case was a white gel-like product, and viscosity measurement with a vibration viscometer (VISCOMATE VM1-A, trade name, manufactured by Yamaichi Electric Industry Co., Ltd.) was impossible.

  The liquid dispersant for magnetic powder preparation according to the present invention has a low initial viscosity and hardly increases in viscosity during storage, so that gelation or solidification does not occur, and the amount of active ingredients in the formulation is large and is a medium. Since the blending amount of water is small, it is sufficient to use a relatively small amount at the time of preparing the magnetic powder solution. Therefore, the bulk and weight are small compared to the conventional liquid dispersant for preparing magnetic powder solution, which is advantageous for transportation and storage.

Claims (3)

  A non-ionic surfactant in the range of HLB 8-14, a silicone antifoaming agent, a liquid dispersant for preparing magnetic powder liquid consisting of higher fatty acid, alcohol and water, and tertiary butyl benzoate is blended, and the viscosity Is in the range of 15 cP to 65 cP.   The liquid dispersant for preparing magnetic powder liquid according to claim 1, wherein the tertiary butyl benzoate is a sodium salt or a potassium salt. The blending ratio of the nonionic surfactant in the range of HLB 8 to 14 is at least 8% by weight, the blending ratio of water is 45 to 65% by weight, and the blending ratio of tertiary butyl benzoate is 10 to 25%. The liquid dispersant for preparing a magnetic powder liquid according to claim 1 or 2, wherein the liquid dispersant is wt%.