JP2009109423A - Thick magnetic-particle dispersion for wet magnetic-particle flaw detection testing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thick magnetic-particle dispersion for wet magnetic-particle flaw detection testing that can easily and rapidly prepare an inspection liquid used for a wet magnetic-particle flaw detection testing method standardized to JIS-Z-2320 and prevents magnetic particles from setting out or being precipitated by low-term storage under a high-temperature environment, for example, in summer seasons, and the opening/closing of a vessel. <P>SOLUTION: In the thick magnetic-particle dispersion for wet magnetic-particle flaw detection testing, 10-20 wt.% of magnetic particles for wet magnetic-particle flaw detection testing having a median diameter of 3-14 μm (volume reference distribution display) and a true specific gravity of 2-3 g/cm<SP>3</SP>is dispersed into an O/W-type white emulsified liquid of water and oil. After the dispersion is left standing at a liquid temperature of 40°C for 90 days, the magnetic particle is dispersed without settling down or precipitating. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is an inspection used in carrying out a wet magnetic particle flaw detection test method that is widely used for flaw detection on surface defects of steel parts such as shafts in a manufacturing line of an automobile manufacturer and billets in a steel material manufacturing line of a steel material manufacturer. The present invention relates to a concentrated magnetic powder dispersion for wet magnetic particle testing, which is used for liquid preparation.

As is well known, the wet magnetic particle flaw detection test method is standardized to JIS-Z-2320, and this method is used for magnetized inspection objects (for example, steel parts such as the shaft: magnetic body and billet Magnetic powder for commercially available wet magnetic particle flaw detection tests (such as steel) such as magnetic materials (using synthetic resin binders such as cellulose acetate synthetic resin and vinyl butyral synthetic resin for magnetic conducting particles such as iron trioxide and pure iron particles) Lumogen Yellow 50790: Trade name: BASF or Festa A: Trade name: Swada's or other fluorescent pigments attached to the median diameter 3 to 70 μm: Volume standard distribution display-the same below-true specific gravity 2 ˜5 g / cm ³ powder; hereinafter referred to as “magnetic powder”) is contacted with a test solution prepared by dispersing in water, and the surface defect portion of the test object (the fine cracks present on or near the surface of the test object) Pinhole) to the test solution This is a test method in which the scattered magnetic particles are gathered to form a magnetic powder pattern, and a surface defect portion is flawed by the magnetic powder pattern (hereinafter, this test method is referred to as “wet magnetic particle flaw detection test”). In preparation, according to the above JIS standard, “... When water is used as a dispersion medium, the detection medium shall contain a surfactant and an antirust (rust) agent. As indicated by “...”, a surfactant is used.

  And the inspection liquid used in the implementation of the wet magnetic particle flaw detection test in the production line of the automobile manufacturer and the steel manufacturer is usually 0.5-2g of magnetic powder per liter of water containing 300-1000ppm of surfactant. The test solution is prepared in a factory of an automobile manufacturer or a steel manufacturer.

  In a factory of an automobile manufacturer or a steel manufacturer, a commercially available magnetic particle dispersant for wet magnetic particle flaw detection test (a liquid obtained by dissolving, emulsifying or dispersing 2 to 10% by weight of a nonionic surfactant of HLB 9 to 16 in water). In addition, a rust preventive agent is added as necessary), and the predetermined amount and a predetermined amount of magnetic powder are kneaded well to obtain a paste-like material, and then the paste-like material is stirred under a predetermined amount. The test solution is prepared by a method of putting it in water.

  Since the preparation method of the test solution requires a weighing operation and a kneading operation, it takes time and labor to prepare. Various preparation methods have been proposed to improve this, and in the past, Patent Document 1 The technique of obtaining magnetic powder by evaporating the organic solvent after mixing the iron powder, fluorescent pigment, synthetic resin binder, organic solvent, and surfactant disclosed in JP As seen in the technique of obtaining a magnetic powder by coating a surfactant after coating a synthetic resin binder, a technique has been proposed in which a surfactant is attached to the magnetic powder to impart water dispersibility to the magnetic powder itself.

  However, in order to prepare a test solution in which magnetic powder is sufficiently dispersed in water, it is necessary to use a nonionic surfactant of HLB 9-16, and this surfactant is a non-volatile viscous liquid. Since the adhering magnetic powder aggregates during storage, there is a problem that a sufficiently dispersed state cannot be obtained at the time of preparing the test solution. As far as the present applicant knows, the magnetic powder adhering the surfactant is an automobile manufacturer. There are no examples of practical use in wet magnetic particle flaw testing on the production lines of steel makers.

  In view of the above problems, the applicant of the present invention has disclosed hydrophilic amorphous silicon dioxide fine particles having an average particle size of 0.01 to 0.05 μm (for example, Aerosil 200: trade name: Nippon Aerosil) on the surface of the magnetic particle disclosed in Patent Document 3. Wet powder obtained by adding 0.05 to 1 part by weight of powdery fluorosurfactant (for example, Unidyne DS-101: trade name: Daikin Industries, Ltd.) to 100 parts by weight of magnetic powder to which Co., Ltd. is attached A water-dispersible magnetic powder composition for magnetic particle testing is proposed, and the magnetic powder composition is excellent in storage stability and does not aggregate after storage for 6 months. If it is put into a non-containing agent), it is possible to prepare a test solution in a dispersed state equivalent to the method of feeding the paste-like material. However, since it is a powder, it takes time to do the weighing work. At automakers and car manufacturers The test liquid prepared personnel requirements within the car factory not led to meet 100%.

  This is because Japanese automobile manufacturers and steel manufacturers are making great efforts to speed up the production line, and each process is speeding up in units of “seconds”. This is because there is a demand for a method for preparing a test solution that takes as little time and effort as possible.

  Therefore, the applicant of the present invention has disclosed 20 to 50% by weight of magnetic powder disclosed in Patent Document 4, 8 to 20% by weight of an alkyl ether type nonionic surfactant having an HLB value of 10 to 12, 2 to 15% by weight of alcohol and water. A concentrated magnetic powder dispersion for wet magnetic particle testing was proposed. The concentrated magnetic powder solution is weighed in a predetermined amount using a measuring cup or graduated cylinder, poured into a predetermined amount of water (not containing a surfactant) and diluted with stirring, and the paste-like material is removed. It is possible to prepare a test solution in a dispersed state equivalent to the case of adopting the method of charging, and the weighing work can be dramatically sped up compared to the weighing work of the water-dispersible magnetic powder composition (powder), If the alcohol component in the formulation gradually evaporates and falls below the required concentration due to long-term storage in a high temperature environment such as summer, or opening and closing of the container, the stability is suddenly impaired, and magnetic powder settles and settles at the bottom of the container There is a problem. Note that such a problem does not occur in a room temperature (20 ° to 25 ° C.) environment.

Japanese Patent Publication No. 44-31072 JP-A-57-141547 JP-A-9-61404 JP-A-10-332644

  In order to solve the above-mentioned problems, the present invention introduces the paste-like material as in the case of preparing a test liquid using a concentrated magnetic powder dispersion for wet magnetic particle testing as disclosed in Patent Document 4. The test solution can be prepared in the same dispersion state as when using the above method, the weighing operation is significantly accelerated, and long-term storage and opening / closing of the container in a high temperature (30 ° to 38 ° C) environment such as summer Another object of the present invention is to provide a concentrated magnetic powder dispersion for a wet magnetic particle flaw detection test that can guarantee that no precipitation or precipitation of magnetic powder occurs.

  In order to achieve the above technical problem, the present inventor has conducted a number of thought-and-error trials and experiments on a combination of a dispersion medium and magnetic powder dispersed in the medium, and as a result, the O / W type is uniform and stable. When a specific amount of magnetic powder having specific powder characteristics is dispersed in a white emulsion as a dispersion medium, magnetic powder settles and settles by long-term storage in a high temperature (30 ° to 38 ° C) environment and opening and closing of the container. The above-mentioned technical problem has been achieved by obtaining the remarkable knowledge that no problem occurs.

  The technical problem can be solved by the present invention as follows.

That is, the present invention is for a wet magnetic particle flaw detection test having a median diameter of 4 to 14 μm (volume reference distribution display—the same applies hereinafter) and a true specific gravity of 2 to ³ g / cm ³ in an O / W white emulsion of water and oil. Concentrated for wet magnetic particle flaw detection test, characterized in that 10 to 20% by weight of magnetic powder is dispersed, and the dispersion is left to settle for 90 days at a liquid temperature of 40 ° C. It is a magnetic powder dispersion (claim 1).

  Further, the present invention is a concentrated magnetic powder dispersion for wet magnetic particle flaw detection test, wherein the oil content of the O / W type white emulsion is organopolyoxane or liquid paraffin (Claim 2).

  The concentrated magnetic powder dispersion for wet magnetic particle testing is according to the present invention, although it is a concentrated magnetic powder dispersion in which the magnetic powder for wet magnetic particle testing is dispersed at a high concentration of 10 to 20% by weight. As shown in FIG. 5, even after the concentrated magnetic powder dispersion is placed in a container and the liquid temperature in the container is kept at 40 ° C. and left for 90 days, the magnetic powder is stably dispersed without being settled or precipitated.

  Therefore, the concentrated magnetic powder dispersion for wet magnetic powder testing according to the present invention can guarantee that the magnetic powder does not settle or precipitate even when stored for a long time in a high temperature (30 ° to 38 ° C.) environment such as summer or when the container is opened and closed. .

  Regarding the phenomenon in which the concentrated magnetic powder for wet magnetic powder test according to the present invention is stably dispersed without being settled or settled even after being kept at the liquid temperature of 40 ° C. in the above state for 90 days. Unfortunately, the present inventors have not been able to carry out the theoretical elucidation, but the present inventor has found that the emulsifier used in the O / W type white emulsion that is the dispersion medium adsorbs to the magnetic powder, and thereby the steric hindrance effect between the magnetic powders. It is presumed that the cohesive force has decreased.

  In addition, a predetermined amount of the concentrated magnetic particle dispersion for wet magnetic particle flaw detection test according to the present invention is weighed using a measuring cup or the like, and poured into a predetermined amount of water (not including a surfactant) under stirring. When diluted, a test solution in a dispersed state equivalent to the method of adding the paste-like material can be prepared. Therefore, the weighing work is compared with the weighing work of the water-dispersible magnetic powder compound (powder). You can speed up dramatically.

Embodiment 1 FIG.

The concentrated magnetic particle dispersion for wet magnetic particle flaw detection test according to the present embodiment is an O / W type white emulsion of water and oil and has a median diameter of 3 to 14 μm and a true specific gravity of 2 to ³ g / cm ³ . This is a dispersion obtained by dispersing magnetic powder for wet magnetic particle testing in a range of 10 to 20% by weight. The dispersion is allowed to stand for 90 days at a liquid temperature of 40 ° C., and the magnetic powder does not settle or settle. It is what you are doing.

  As the oil, organopolysiloxane and liquid paraffin are preferable, and when these are used, a pseudo pattern (called “noise” in the industry) is used when the prepared inspection liquid is used (when the wet magnetic particle inspection test is performed). ) Can be suppressed.

  O / W type white emulsion is a conventional method (simultaneous emulsification method or paste method) using known emulsifiers (anionic surfactants, nonionic surfactants, etc.) that can form uniform and stable O / W type emulsions. However, even after standing at a liquid temperature of 40 ° C. for 90 days, the liquid phase does not separate into two phases, and the emulsion stability that does not solubilize is necessary. For example, polyoxyethylene polyoxypropylene lauryl ether (HLB6.5-8), polyoxyethylene nonylphenyl ether (HLB10.5), sorbitan monooleate, polyoxyethylene (20 mol) sorbitan trioleate, silicone System emulsifier KF945A (trade name: manufactured by Shin-Etsu Chemical Co., Ltd.), etc., and mixing ratio of oil and the emulsifier within the range of oil: emulsifier = 1: 1-4 (weight ratio) What is necessary is just to select the quantity of a mixture within the range of 7 to 32 weight%.

The magnetic powder for wet magnetic particle testing can be selected from commercially available products having a powder characteristic within a median diameter of 3 to 14 μm and a true specific gravity of 2 to ³ g / cm ^3. Specifically, , Magnetic powder super magna LY-30 (product name: median diameter 3.5 μm, true specific gravity 2.0 g / cm ³ : manufactured by Marktec Co., Ltd.), super magna LY-10 (product name: median diameter 12 μm, true) Specific gravity 2.3 g / cm ³ : manufactured by Marktec Corporation) and Super Magna LY-2300 (trade name: median diameter 13 μm, true specific gravity 2.8 g / cm ³ : manufactured by Marktech Corporation).

  When the median diameter of the magnetic powder for wet magnetic particle flaw detection test used exceeds 14 μm, the resulting concentrated magnetic particle dispersion is allowed to settle at 90 ° C. for 90 days, and then the magnetic particles settle or precipitate. As far as the present inventor is aware, magnetic powder for wet magnetic particle flaw detection test having a median diameter of less than 3 μm is not commercially available.

When the true specific gravity of the magnetic powder for wet magnetic particle flaw detection test used exceeds ³ g / cm ³ , the resulting concentrated magnetic powder dispersion liquid is allowed to settle at 90 ° C. for 90 days, and then the magnetic powder settles or precipitates. As far as the present inventor is aware, there is currently no commercially available magnetic powder for wet magnetic particle flaw detection test having a true specific gravity of less than 2 g / cm ³ within a median diameter of 3 to 14 μm.

  The magnetic powder for wet magnetic particle flaw detection test is dispersed within a range of 10 to 20% by weight with respect to the total amount of the concentrated magnetic powder dispersion.

  As the ratio of the magnetic powder for wet magnetic particle testing increases, the dispersion stability of the magnetic powder after standing for 90 days at a liquid temperature of 40 ° C. decreases. When the ratio of the magnetic powder exceeds about 25% by weight, a paste-like material Become. If the proportion of the magnetic powder is reduced, the dispersion stability is improved, but on the other hand, a large amount of magnetic powder dispersion is required for preparing the test solution, which requires time and labor for the weighing operation.

  From the viewpoints of weighing operation, size of magnetic powder dispersion liquid filled container, storage space, transportation cost, etc., it is preferable to disperse the magnetic powder for wet magnetic particle testing within a range of 10 to 20% by weight.

  It is easy to manufacture a concentrated magnetic powder dispersion for wet magnetic particle testing according to the present embodiment.

  That is, first, organosiloxane or liquid paraffin and polyoxyethylene polyoxypropylene lauryl ether (HLB6.5-8), polyoxyethylene nonylphenyl ether (HLB10.5), sorbitan monooleate, polyoxyethylene (20 mol) sorbitan The emulsifier selected from triolate and silicone-based emulsifier KF945A (trade name: manufactured by Shin-Etsu Chemical Co., Ltd.) is weighed so that the mixing ratio is within the range of the former: the latter = 1: 1 to 4 (weight ratio). Take the sample into a stainless steel tank, heat it, and maintain the liquid temperature in the tank at 40 ° C. Stir for about 30 minutes using a homogenizer, then maintain the liquid temperature and continue stirring. After adding water into the tank little by little so that the amount of the mixture in the tank is in the range of 7 to 32% by weight, the liquid further If stirring for about 30 minutes while maintaining, O / W type white emulsion is obtained.

Next, after cooling the obtained O / W type white emulsion to room temperature (about 20 ° C.), the white emulsion is stirred using a propeller type electric mixer, and magnetic powder super magna LY- 30 (trade name: median diameter 3.5 μm, true specific gravity 2.0 g / cm ³ : manufactured by Marktec Co., Ltd.), Super Magna LY-10 (trade name: median diameter 12 μm, true specific gravity 2.3 g / cm ³ : marktech stock) And magnetic powder selected from Super Magna LY-2300 (trade name: median diameter 13 μm, true specific gravity 2.8 g / cm ³ : manufactured by Marktec Co., Ltd.) within the range of 10-20% by weight of the total amount After the addition, the mixture is further stirred at room temperature for about 60 minutes to obtain the target concentrated magnetic powder dispersion for wet magnetic particle testing.

  It should be noted that the concentrated magnetic powder dispersion for wet magnetic particle flaw detection test obtained here includes rust preventives, preservatives, wetting agents and the like that are commonly used in the implementation of the wet magnetic particle flaw detection test, as long as the dispersion stability of the magnetic powder is not impaired. The required amount can be added.

  It is also easy to prepare a test liquid using the dense magnetic powder dispersion liquid for wet magnetic particle flaw detection test obtained here.

  While stirring the water surface with a spatula or the like in a tank containing the required amount of water (without surfactant), the required amount of the concentrated magnetic powder dispersion for wet magnetic particle testing (usually water) If an amount of magnetic powder of 0.5 to 2 g per liter) is weighed out using a measuring cup or the like, the concentrated magnetic powder dispersion liquid is instantaneously dispersed, and a test liquid in which the magnetic powder is uniformly dispersed can be prepared.

Embodiment 2. FIG.

The concentrated magnetic particle dispersion for wet magnetic particle flaw detection test according to the present embodiment is an O / W type white emulsion with water oil within a median diameter of 3 to 14 μm and a true specific gravity of 2 to ³ g / cm ³ . Is a dispersion obtained by dispersing magnetic powder for wet magnetic particle testing in a range of 10 to 18% by weight and adding a water-soluble rust inhibitor in a range of 5 to 7% by weight. The magnetic powder is dispersed without being settled or precipitated after standing at 40 ° C. for 90 days.

  The O / W type white emulsion in the concentrated magnetic powder dispersion for wet magnetic particle testing is the same as that in the first embodiment, and the type of magnetic powder for wet magnetic particle testing is also the same as in the first embodiment. Is the same.

  A commercially available water-soluble rust inhibitor can be used as the water-soluble rust inhibitor, but sodium nitrite is preferable from the viewpoint of rust prevention performance, solubility, price, and the like.

  The amount of sodium nitrite added may be selected within the range of 5 to 7% by weight, and if it is less than 5% by weight, it is difficult to obtain a sufficient rust prevention effect for steel parts and steel materials. If the amount added is increased, the rust-preventing effect is improved, but it is practically sufficient to add up to 7% by weight. In addition, it is preferable to reduce the ratio of the magnetic powder for a wet magnetic particle flaw detection test corresponding to the addition ratio of sodium nitrite.

  The concentrated magnetic powder dispersion for wet magnetic particle flaw detection test according to the present embodiment is easy to manufacture, and is the same as in the first embodiment except that sodium nitrite is added simultaneously with adding the magnetic powder to the O / W type white emulsion. According to the manufacturing method.

  In addition, it is easy to prepare a test liquid using the concentrated magnetic powder dispersion for wet magnetic particle flaw detection test according to the present embodiment, and the same method as in the first embodiment may be used.

  The present invention will be described in detail with reference to examples and comparative examples.

  Example 1: First, 25 g of organopolysiloxane and 100 g of polyoxyethylene polyoxypropylene lauryl ether (HLB8) were weighed, placed in a stainless steel tank, and heated to bring the liquid temperature in the tank to 40 ° C. While maintaining, using a homogenizer for 30 minutes, maintain the liquid temperature, and while continuing stirring, add 600 g of tap water to the tank in small portions, and then maintain the liquid temperature. Stir for minutes to obtain an O / W type white emulsion (hereinafter referred to as “Emulsion 1”).

Next, after the emulsion 1 in the tank is cooled to room temperature (about 20 ° C.), the emulsion is stirred using a propeller type electric mixer, and magnetic powder super magna LY-10 for wet magnetic particle testing (trade name: 175 g of median diameter 12 μm, true specific gravity 2.3 g / cm ³ (manufactured by Marktec Co., Ltd.) is added, and the mixture is further stirred for 60 minutes at room temperature to be a concentrated magnetic powder dispersion for wet magnetic particle testing (hereinafter referred to as “magnetic powder dispersion 1”). 1000 g was obtained.

  Example 2: First, 50 g of liquid paraffin (white oil WO70: trade name: manufactured by Mobil Oil Co., Ltd.) and 150 g of polyoxyethylene polyoxypropylene lauryl ether (HLB6.5) were weighed and placed in a stainless steel tank. While stirring and maintaining the liquid temperature in the tank at 40 ° C. for 30 minutes using a homogenizer, maintain the liquid temperature and continue stirring while adding 600 g of tap water to the tank. After adding a small amount, the mixture is further stirred for 30 minutes while maintaining the liquid temperature to obtain an O / W type white emulsion (hereinafter referred to as “Emulsion 2”).

Next, the emulsion 2 in the tank is cooled to room temperature (about 20 ° C.), and then the emulsion is stirred using a propeller-type electric mixer, and the magnetic powder super magna LY-2300 (product name: Add 200g of median diameter 13μm, true specific gravity 2.8g / cm ³ (made by Marktec Co., Ltd.) and stir for 60 minutes at room temperature, and then concentrate magnetic powder dispersion for wet magnetic particle testing (hereinafter referred to as “magnetic powder dispersion 2”) 1000 g was obtained.

  Example 3: First, 50 g of organopolysiloxane and 200 g of polyoxyethylene nonylphenyl ether (HLB10.5) were weighed, placed in a stainless steel tank, and heated to bring the liquid temperature in the tank to 40 ° C. While maintaining, using a homogenizer for 30 minutes, maintain the liquid temperature, and while continuing stirring, add 550 g of tap water to the tank in small portions, and then maintain the liquid temperature. Stir for a minute to obtain an O / W type white emulsion (hereinafter referred to as “Emulsion 3”).

Next, after the emulsion 3 in the tank is cooled to room temperature (about 20 ° C.), the emulsion is stirred using a propeller-type electric mixer, and magnetic powder super magna LY-10 for wet magnetic particle testing (trade name: Median diameter 12 μm, true specific gravity 2.3 g / cm ³ : Marktech Co., Ltd. (150 g) and sodium nitrite 50 g are added, and further stirred for 60 minutes at room temperature. 1000 g) (referred to as “dispersion 3”) was obtained.

  Example 4: First, 100 g of liquid paraffin (white oil WO70: trade name: manufactured by Mobil Sekiyu Co., Ltd.), 50 g of sorbitan monooleate and 50 g of polyoxyethylene (20 mol) sorbitan trioleate were weighed and made of stainless steel. Place in a tank, heat and maintain the liquid temperature in the tank at 40 ° C, and stir for 30 minutes using a homogenizer. Then, maintain the liquid temperature and continue stirring, After adding 600 g of water little by little, the mixture is further stirred for 30 minutes while maintaining the liquid temperature to obtain an O / W type white emulsion (hereinafter referred to as “Emulsion 4”).

Next, after the emulsion 4 in the tank is cooled to room temperature (about 20 ° C.), the emulsion is stirred using a propeller-type electric mixer, and magnetic powder super magna LY-10 (product name: 200 g of median diameter 12 μm, true specific gravity 2.3 g / cm ³ (manufactured by Marktec Co., Ltd.) is added, and the mixture is further stirred for 60 minutes at room temperature and concentrated magnetic powder dispersion for wet magnetic particle testing (hereinafter referred to as “magnetic powder dispersion 4”) 1000 g was obtained.

  Example 5: First, 30 g of organopolysiloxane, 20 g of silicone emulsifier KF945A (trade name: manufactured by Shin-Etsu Chemical Co., Ltd.) and 10 g of sorbitan monooleate were weighed, placed in a stainless steel tank, heated, and After stirring for 30 minutes using a homogenizer while maintaining the liquid temperature in the tank at 40 ° C., 700 g of tap water was added to the tank in small portions while maintaining the liquid temperature and continuing stirring. Further, the mixture is stirred for 30 minutes while maintaining the liquid temperature to obtain an O / W type white emulsion (hereinafter referred to as “Emulsion 5”).

Next, after the emulsion 5 in the tank is cooled to room temperature (about 20 ° C.), the emulsion is stirred using a propeller type electric mixer, and the magnetic powder super magna LY-30 (product name: 175 g of median diameter 3.5 μm, true specific gravity 2.0 g / cm ³ : Marktech Co., Ltd.) 175 g and sodium nitrite 65 g are added, and the mixture is further stirred for 60 minutes at room temperature. 1000 g) of “magnetic powder dispersion 5” was obtained.

  Comparative Example 1: First, 25 g of liquid paraffin (white oil WO70: trade name: manufactured by Mobil Sekiyu Co., Ltd.) and 100 g of polyoxyethylene isodecyl ether (HLB8) were weighed, placed in a stainless steel tank, and heated. While maintaining the liquid temperature in the tank at 40 ° C. for 30 minutes using a homogenizer, 600 g of tap water was added to the tank little by little while maintaining the liquid temperature and continuing stirring. Thereafter, the mixture is further stirred for 30 minutes while maintaining the liquid temperature to obtain an O / W type white emulsion (hereinafter referred to as “Comparative Emulsion 1”).

Next, after cooling the comparative emulsion 1 in the tank to room temperature (about 20 ° C.), the emulsion is stirred using a propeller-type electric mixer, and the magnetic powder super magna LY-10 for wet magnetic particle testing (product) Name: median diameter 12 μm, true specific gravity 2.3 g / cm ³ : Marktech Co., Ltd. 175 g was added, and further stirred for 60 minutes at room temperature (hereinafter referred to as “comparative magnetic powder dispersion 1”). ) 1000g was obtained.

  Comparative Example 2: First, 50 g of organopolysiloxane and 150 g of polyoxyethylene octylphenyl ether (HLB12) were weighed, placed in a stainless steel tank, and heated to maintain the liquid temperature in the tank at 40 ° C. While stirring for 30 minutes using a homogenizer, the liquid temperature was maintained, and while continuing stirring, 600 g of tap water was added to the tank in small portions, and further stirred for 30 minutes while maintaining the liquid temperature. Thus, an O / W type white emulsion (hereinafter referred to as “Comparative Emulsion 2”) is obtained.

Next, after cooling the comparative emulsion 2 in the tank to room temperature (about 20 ° C.), the emulsion is stirred using a propeller-type electric mixer, and the magnetic powder super magna LY-10 for wet magnetic particle testing (product) Name: Median diameter 12 μm, true specific gravity 2.3 g / cm ³ : Mark Tech Co., Ltd. 200 g is added, and further stirred for 60 minutes at room temperature (hereinafter referred to as “Comparative Magnetic Powder Dispersion 2”). ) 1000g was obtained.

  Comparative Example 3: First, 25 g of organopolysiloxane and 100 g of polyoxyethylene polyoxypropylene lauryl ether (HLB8) were weighed, placed in a stainless steel tank, and heated to bring the liquid temperature in the tank to 40 ° C. While maintaining, using a homogenizer for 30 minutes, maintain the liquid temperature, and while continuing stirring, add 700 g of tap water to the tank in small portions, and then maintain the liquid temperature. Stir for a minute to obtain an O / W type white emulsion (hereinafter referred to as “Comparative Emulsion 3”).

Next, after cooling the comparative emulsion 3 in the tank to room temperature (about 20 ° C.), the emulsion is stirred using a propeller-type electric mixer, and magnetic powder supermagna LY-60 for wet magnetic particle testing (product) Name: median diameter 6 μm, true specific gravity 4.2 g / cm ³ : Mark Tech Co., Ltd. (175 g) was added, and the mixture was further stirred at room temperature for 60 minutes and referred to as a comparative concentrated magnetic powder dispersion (hereinafter referred to as “comparative magnetic powder dispersion 3”). ) 1000g was obtained.

  Comparative Example 4: First, 50 g of liquid paraffin (white oil WO70: trade name: manufactured by Mobil Petroleum Co., Ltd.) and 150 g of polyoxyethylene polyoxypropylene lauryl ether (HLB8) were weighed and placed in a stainless steel tank. While stirring and maintaining the liquid temperature in the tank at 40 ° C. for 30 minutes using a homogenizer, while maintaining the liquid temperature and continuing stirring, gradually add 600 g of tap water to the tank. After the addition, the mixture is further stirred for 30 minutes while maintaining the liquid temperature to obtain an O / W type white emulsion (hereinafter referred to as “Comparative Emulsion 4”).

Next, the comparative emulsion 4 in the tank was cooled to room temperature (about 20 ° C.), and then the emulsion was stirred using a propeller-type electric mixer, with a comparative magnetic powder (median diameter 18 μm, true specific gravity 3.0 g). / Cm ³ : Magnetic powder made by attaching fluorescent pigment particle powder to triiron tetroxide powder with vinyl acetate resin binder: Marktech Co., Ltd.) 200 g was added, and the mixture was further stirred for 60 minutes at room temperature. 1000 g of a dispersion (hereinafter referred to as “comparative magnetic powder dispersion 4”) was obtained.

  Evaluations according to Examples 1 to 5 and Comparative Examples 1 to 4 were performed by the following emulsification test, concentrated magnetic powder liquid dispersion stability test, wet magnetic powder flaw detection test, and test liquid foam test.

  Emulsification test: Emulsified liquids 1 to 5 and comparative emulsified liquids 1 to 4 were respectively applied to 20 g of each transparent glass test tube, and each test tube was allowed to stand at room temperature (25 ° C.) for 90 days. -The state of the water separation layer was visually observed, and those with no separation were evaluated as “◯”, and those separated were evaluated as “×”.

  Thick magnetic powder dispersion stability test: 200 g of each of the magnetic powder dispersions 1 to 5 and the comparative magnetic powder dispersions 1 to 4 are directed to each transparent glass beaker, and each beaker is covered with an aluminum foil having small holes. In a thermostatic chamber, after maintaining the liquid temperature in the beaker at 40 ° C. for 90 days, the state of each dispersion was visually observed, and “○”, 10% (volume) ) When the following supernatant was generated but there was no precipitation, it was evaluated as “Δ”, and the precipitate was evaluated as “x”.

  Wet magnetic particle testing: Magnetic powder dispersions 1 to 5 and comparative magnetic powder dispersions 1 to 4, and magnetic powder dispersions 1 to 5 and comparative magnetic powder dispersions 1 to 4 after the concentrated magnetic powder dispersion stability test were used. Each measuring solution was weighed using a graduated cylinder so that the magnetic powder concentration was 1 g / l, and each weighed magnetic powder dispersion was put into each tank containing tap water under stirring to prepare each test solution.

  For each of the above test solutions, the "contrast specimen type 1" specified in JIS-Z-2320-2 is soaked and slowly pulled up, and a defect formed on the test surface by irradiating with an ultraviolet lamp in a dark room The instruction pattern is visually observed, and the defect instruction pattern by the test liquid using the magnetic powder dispersion (including the comparative magnetic powder dispersion) before the concentrated magnetic powder dispersion stability test is performed and the concentrated magnetic powder dispersion stability test is performed. Evaluation was made as “◯” when no change was observed in the defect indication pattern by the inspection liquid using the magnetic powder dispersion (including the comparative magnetic powder dispersion), and “X” when change was observed.

  Test liquid foaming test: For each test liquid prepared in the wet magnetic particle flaw detection test, visually check the foaming state of each test liquid under stirring in accordance with “Foamability” specified in JIS-Z-2320-2. When the bubbles were not overflowed from the test container, “○” was evaluated, and when the bubbles were overflowed, “X” was evaluated.

  Table 1 shows each evaluation result in each test.

  According to the present invention, the preparation of a test solution used in a wet magnetic particle flaw detection test can be remarkably speeded up. Moreover, magnetic particles can be stored by long-term storage or opening / closing of a container in a high temperature (30 ° to 38 ° C.) environment such as summer. We can provide a concentrated magnetic powder dispersion for wet magnetic particle testing that does not cause sedimentation or settling, so that we can respond to the request of wet magnetic particle testing personnel in each production line of automobile manufacturers and steel manufacturers that need to prepare a large amount of inspection liquid. It can be said that the industrial applicability of the present invention is great.

Claims (2)

Will be O / W type white emulsion by dispersing 10 to 20 wt% magnetic powder for wet magnetic particle inspection of true specific gravity 2 to 3 g / cm ³ median diameter 3～14Myuemu (volume basis distribution display) on the water and oil A concentrated magnetic powder dispersion for wet magnetic particle testing, wherein the magnetic powder is dispersed without being settled or settled after being left to stand at a liquid temperature of 40 ° C. for 90 days. 2. The concentrated magnetic powder dispersion for wet magnetic particle testing as claimed in claim 1, wherein the oil is an organopolyoxane or liquid paraffin.