JPS60110326A - Dispersant for magnetic powder containing liquid used in wet-type magnetic flaw detecting method - Google Patents

Abstract

PURPOSE:To provide the titled dispersant capable of maintaining a dispersing effect and a defoaming effect for a long period of time at a high temperature, by adding specified amounts of a soap and an alcohol to a known dispersant for a magnetic powder containing liquid. CONSTITUTION:The dispersant for a magnetic powder containing liquid is prepared from 1-3wt% of a silicone defoaming agent prepared as an oil-in-water type emulsion of dimethylpolysiloxane oil by using a polyetylene glycol type non-ionic surface active agent havint an HLB value of 10-11 and a cloud point of not higher than 40 deg.C, 2-6wt% of a polyetylene glycol type non-ionic surface active agent having an HLB value of 10-13 and a cloud point of not lower than 50 deg.C, 1-40wt% of a soap, 0.5-25wt% of an alcohol and the balance of water. The soap is sodium laurate or the like, and the alcohol is methanol, ethanol or the like. Accordingly, a dispersant is obtained which can maintain the dispersing effect and the defoaming effect for a long period of time at a high temperature of about 40-50 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dispersant for magnetic powder liquid used in wet magnetic particle flaw detection, which maintains dispersion and defoaming effects even at high temperatures of about 40'' to 50'C. An object of the present invention is to provide a dispersant for magnetic powder liquid that has the ability to be maintained over a long period of time and has excellent long-term storage stability.

In general, magnetic flaw detection is well known as a typical non-destructive testing method for magnetic materials. In this method, when a defect such as a crack or a pinhole exists on the surface of a magnetic material (for example, a square piece of steel) or in a relatively shallow part below the surface, when a current is passed through the magnetic material, the magnetic resistance of the defective part is reduced. Because it is larger than other healthy parts, magnetic flux drifts in that part and leakage force into the air (this phenomenon occurs). Magnetically conductive powder such as powder (generally called "magnetic powder". "Magnetic powder" coated with a fluorescent substance is called "fluorescent magnetic powder") is scattered, and the above-mentioned This is a flaw detection method in which magnetic particles are collected in the area of leakage magnetic flux, and the defective part of the object to be inspected is detected by the pattern of the magnetic particles. A method in which magnetic particles are dispersed onto the surface of the object to be inspected (generally called the "dry magnetic flaw detection method"), and a method in which magnetic particles are dispersed in water using a surfactant at a concentration of usually 1 to 14 sf/water. A method in which a magnetic powder dispersion liquid (generally called a ``magnetic particle liquid'') is made and the magnetic particle liquid is dispersed on the surface of the object to be inspected (generally called a ``wet magnetic flaw detection method''). The latter wet magnetic flaw detection method is particularly widely used in the steel industry and is used to detect flaws in steel materials such as square billets, round billets, etc.

The present invention relates to a "dispersant for magnetic powder liquid" used in preparing magnetic powder liquid in the above-mentioned wet magnetic flaw detection method.

As mentioned above, the magnetic powder concentration of the magnetic powder liquid is usually 1 to 3 g/1 water.
However, if it is less than 1g/water 14, the amount of magnetic particles that gather at the defective part on the surface of the object to be inspected will be small and practical flaw detection accuracy will not be obtained, and 5g/water 11 This is because, in the above case, magnetic particles will adhere to areas other than the defective part, causing a "bank ground" phenomenon and reducing flaw detection accuracy.

As is well known, when spraying a magnetic powder solution with a magnetic particle concentration of 1 to 14 sf/water, it is necessary to: ■ ensure that the magnetic particles are sufficiently dispersed;
■It is required that the magnetic powder liquid uniformly wets the surface of the object to be inspected.

Furthermore, the dispersed magnetic powder liquid is collected and reused, and in this industry, normally, a magnetic powder liquid stirring device as shown in Fig. 1 is used, the magnetic powder liquid is put into a tank 1, and a pump 2 is used from the tank 1. transport the magnetic powder liquid to a predetermined spraying place and sprinkle it on the object to be inspected, collect the dispersed magnetic powder liquid into tank 1, and transfer the collected magnetic powder liquid from tank 1 again to the predetermined spraying place using pump 2. The method is to repeat the cycle of transporting and dispersing. Regarding this aspect, for example,
This is shown in detail in Japanese Patent No. 7-41518.

That is, the magnetic powder liquid is always used in a stirred state, and the magnetic powder liquid during use is in a state where it is very easy to foam. It is easy to understand that if there is a lot of foaming, foaming will occur on the surface of the object to be inspected, interfering with flaw detection, and the foam will overflow from the tank 1. . Therefore, in addition to (1) and (2) above, it is required that the magnetic powder liquid during use does not cause any bubbling phenomenon.

In the industry, dispersants for magnetic powder liquids are used in preparing magnetic powder liquids in order to satisfy the above requirements (1) to (2).

Typical formulations of dispersants for magnetic powder liquids currently on the market are:
It is a liquid material consisting of "1 to 3% by weight silicone antifoaming agent (hereinafter, all weight% is simply abbreviated as "chi"), 2 to 6% surfactant, and the balance water. Contains 3-5% of rust preventive (in addition, in formulations that include a rust preventive, the amount of water commensurate with the amount of water added is subtracted and the "remaining water" is the amount of water added).

)this? There is.

To explain in more detail, first, the silicone antifoaming agent in the formulation is dimethyp polysiloxane oil, which is considered to be optimal as an antifoaming agent to be added to a dispersant for magnetic powder liquid, and has a FILB value l.
A silicone antifoaming agent made into an oil-in-water (OA') emulsion using a polyethylene glycol type nonionic surfactant of 0 to 11, the blending ratio of which is dimethylpolysiloxane oil/l/10 to 30. H, surfactant 5
~io, the remainder being water, and this ratio is considered to be the optimum ratio for maintaining a stable oil-in-water emulsion during use. In addition, as a commercially available product, [Silicone antifoaming agent KM68]
-IF), “KM-70J, [KM-72FJ (
All are well known under the trade name of Shin-Etsu Chemical Co., Ltd.).

The silicone antifoaming agent mentioned above is, of course, blended to meet the above requirement (2).

Next, the surfactant in the formulation is ]-TLB value 10-1
3, a polyethylene glycol type nonionic surfactant. It is said that in order to keep the oil-in-water emulsion of the silicone antifoaming agent stable during use, it is necessary to use a surfactant with properties similar to those of the surfactant used in the silicone antifoaming agent. Selected based on viewpoint. Specifically, polyoxyethylene nonyl phenyl ether μ, polyoxyethylene lauryl ether, polyoxyethylene dopanol ether, etc. are used.

The above-mentioned surfactant is blended to satisfy the requirements (1) and (2) above. As mentioned above, the silicone antifoaming agent also contains a surfactant, but it is not possible to sufficiently disperse the magnetic particles with just the amount of surfactant contained in the silicone antifoaming agent. As stated above, 9.2 to 6% of surfactant is blended as the amount of surfactant necessary to sufficiently disperse the magnetic powder and satisfy wettability during spraying. Furthermore, this 2-6%
The specified amount does not include the amount of surfactant that is pre-blended in the silicone antifoaming agent. ) Next, the rust preventive agent added as necessary is sodium nitrite, triethanolamine, etc., and is added when it is necessary to prevent rusting of the object to be inspected.

The commercially available dispersant for magnetic powder liquid used in the wet magnetic flaw detection method, which has the above formulation, can be used to reduce the concentration of the dispersant from 1 to 1.
3q6/water IIl, the concentration of magnetic particles satisfies the requirements of (1) and (2) above, and ensures that sufficient flaw detection accuracy is obtained for practical use. - Guarantees that the defoaming effect is maintained for 20 hours.

In addition, there is a dispersant for magnetic powder liquid that maintains the antifoaming effect for a long time, which is published in Japanese Patent Application Laid-open No. 58-15555A. The dispersant is blended with a dimethylpolysiloxane-polyoxyalkylene copolymer (however, the number of moles of ethylene group is 5 moles JJ, T) from 1 to 0.5. In the formulation, the amount of water commensurate with the amount of water added is subtracted to form the "residual water." When prepared, the magnetic powder liquid has the following properties at room temperature:
4 after starting to use the magnetic powder liquid after satisfying the requirements of ■ and ■ above.
This guarantees that the defoaming effect is maintained for 0 to 50 hours.

The dimethylpolysiloxane-polyoxyalkylene copolymer is a known substance, for example, one of the following formula is well known:
99oJ, “5P-2972J,” “F3P-565
7J (all product names, manufactured by Shin-Etsu Chemical Co., Ltd.).

Further, the amount added must be in the range of 0.1 to 0.5%; if it is less than 0.1%, there will be no effect and the foaming phenomenon of the magnetic powder liquid will be promoted. By adding 0.1 or more, the defoaming effect maintenance time can be significantly extended.
The greater the amount added, the greater the effect, but
If the amount is more than 0.5, it will have a negative effect on the dispersibility of the magnetic particles and the wettability of the liquid, so it is said that the addition should be limited to a maximum of 0.5.

In addition, the use concentration of the above-mentioned commercially available dispersant for magnetic powder liquid and a dispersant for magnetic powder liquid obtained by adding dimethylpolysiloxane-polyoxyalkylene copolymer (hereinafter referred to as known dispersant) is 1 to 1. The ratio of 6%/water 11 is
In order to satisfy the requirements of (1) and (2) above, a concentration of at least 1%/water 11 or more is required, and even if the concentration is 3%/water 1 water 4, this dispersion and wetting effect will be significantly improved. This is because it is not accepted. Further, the antifoaming effect maintenance time hardly changes even when the concentration of the known dispersant added to the magnetic powder liquid is 3 parts/water 1a or more.

The known dispersants described above have the following drawbacks.

That is, when the liquid temperature of the magnetic powder liquid prepared using a known dispersant is at room temperature (20° to 50°C), it exhibits high performance that satisfies the requirements of (1), (2) and (2) above without any problem. When the temperature exceeds about 40° C., the dispersion effect and antifoaming effect are suddenly lost, and the flaw detection accuracy is extremely reduced and a severe bubbling phenomenon occurs.

Of course, during the wet magnetic flaw detection method, the liquid temperature of the magnetic powder liquid was 40℃.
Normally, situations in which this value is exceeded rarely occur.

However, during the summer, square billets that have been subjected to heat treatments such as rolling and annealing are not cooled to room temperature.
When wet magnetic flaw detection is applied to this, it is not uncommon for the temperature of the magnetic powder liquid to exceed 40°C.
In some cases, the known dispersants exhibit the above-mentioned drawbacks.

As far as the present inventor knows, the liquid temperature of magnetic powder liquid exceeds about 40''C in Japan and other countries. However, there has been a strong desire for a dispersant for magnetic powder liquids that does not lose its dispersing and antifoaming effects.

The inventor of the present invention has thoroughly investigated the factors that cause known dispersants to suddenly lose their dispersing and antifoaming effects when the liquid temperature of the magnetic powder liquid exceeds approximately 40°C. I learned that this problem lies in the disadvantages of the surfactants (including the surfactants in the silicone antifoaming agents mentioned above). To be more specific,
The above-mentioned conventional and known dispersants contain 1 to 3% of the silicone antifoaming agent, and the silicone antifoaming agent contains dimethylpolysiloxane oil as an oil-in-water emulsion] - TLBLB value ~11 polyethylene glycol type nonionic surfactants are included. As is well known, the optimum I (LB value) for making dimethylpolysiloxane oil into an oil-in-water emulsion is 10.5, and the T-
A polyethylene glycol type nonionic surfactant with TLBLB value of 5 is used alone, or HLB value [10 to
A plurality of polyethylene glycol type nonionic surfactants (11) are used in combination so as to have a TLBLB value of 5, and it is generally believed that relying on the latter can produce a more stable oil-in-water emulsion. There is.

By the way, the critical point of an ethylene glycol type nonionic surfactant with a TJLB value of 11 or less is about 40''C or less.

As is well known, polyethylene glyco-type nonionic surfactants have the property of being hydrophobic, being soluble in water at temperatures below the point, and not soluble in water at temperatures above the point.

That is, known dispersants always contain polyethylene glycol type nonionic surfactants of 'ELB@10-11, and the critical point is below 40°C, so magnetic powder liquids using known dispersants When the liquid temperature exceeds 40°C, the surfactant separates from water and dimethylpolysiloxane oil. The separated surfactants adhere to each other to form hydrophobic oil droplets, to which the magnetic particles adhere, and the dimethylpolysiloxane oil separated from the surfactant naturally separates from water as well, forming hydrophobic oil droplets. Oil droplets are formed, to which the magnetic particles also adhere, and thus the magnetic particles are no longer evenly dispersed. At the same time, dimethylpolysiloxane oil separates from water, resulting in foaming.

As mentioned above, the reason why known dispersants lose their dispersing and defoaming effects when the liquid temperature of the magnetic powder liquid exceeds about 40"C is due to the silicone contained in known dispersants. The polyethylene glycol type nonionic surfactant with HLB value lO~11 contained in the antifoaming agent has a dot of about 40
This is due to the fact that the temperature is below ℃.

Therefore, as a solution, it is natural to think that the surfactant contained in the silicone antifoaming agent should be one with a high resolution, for example, one with a border point of about 50'c or more. It will be done. However, in order to maintain dimethylpolysiloxane oil as a stable oil-in-water emulsion during use, the FTLB value must be 11 or less, or less than 40.
It is necessary to use a polyethylene glycol type nonionic surfactant with a temperature below ℃, and if a polyethylene glycol type nonionic surfactant with a critical point of about 50°C (HLB value in this case is 12 to 15) is used, For example, the silicone antifoaming agent is unable to maintain dimethylpolysiloxane as a stable oil-in-water emulsion during use, even if the liquid temperature is below 40'C.

In addition, if we focus only on the dispersion effect of magnetic powder, 2.
6) A polyethylene glycol type nonionic surfactant with a TLB value of 10 to 13 is mixed with a polyethylene glycol type nonionic surfactant with an HLB value of 12
~15, it may be possible to change to one with a point of about 50'C or higher, but in this case, even if a dispersion effect is obtained, an antifoaming effect cannot be obtained, and if the temperature of the magnetic powder liquid is below 40°C. However, severe bubbling occurs. (this is,]
-When blending a polyethylene glycol type nonionic surfactant with a TLB value of 12 to 15 and a temperature of about 50°C or higher, use it because the properties are significantly different from the surfactant contained in the silicone antifoaming agent. Inside the oil-in-water type emma of the silicone antifoaming agent) V! This is because the dimethylpolysiloxane oil is separated from the water due to the destruction of the water. Another effect is that the higher the image point, the more hydrophilic groups there are in the surfactant and the poorer compatibility with 'lx, i7, and hydrophobic dimethylpolysiloxane. ) The present inventor has conducted research to find a solution that can be achieved without changing the surfactant contained in the known dispersant, and when using the known dispersant with a specific amount of soap added, the magnetic powder liquid Even if the temperature of the liquid exceeds 40°C, it is possible to maintain the same dispersion effect and defoaming effect for a long time as when the liquid temperature is room temperature, and moreover, it does not have any adverse effect on the above-mentioned item (2). We have found the remarkable fact that there is no such thing.

The amount of soap added is important; unless at least one soap is added, the dispersion effect and antifoaming effect cannot be maintained when the temperature of the magnetic powder liquid exceeds about 40°C. Moreover, if the content is 40% or more, the viscosity of the dispersant itself is very high, making it difficult to handle.

That is, 1 to 40% of soap is added to the formulation of a known dispersant (
In addition, in a prescription containing soap, the amount of water commensurate with the amount of soap added is subtracted and the "remaining water" is the one that is used. ), even if the temperature of the magnetic powder liquid exceeds 40°C, up to approximately 50°C, the above requirements ① and ② must be met, and 10-20 hours after the start of use of the magnetic powder liquid (dimethylpolysiloxane- In a formulation containing 0.1 to 0.5% of polyoxyalkylene copolymer, the antifoaming effect can be maintained for 40 to 50 hours.

Based on the above-mentioned knowledge, the present inventor completed a dispersant for magnetic powder liquid that can be used at high temperatures, and filed a patent application (Japanese Patent Application No. 58-1
No. 431337).

By the way, when a soap with a rating of 1 to 40 is blended with a known dispersant, it can meet the requirements of (1) to (3) above at high temperatures (approximately 40° to 50°C), but there is a problem with its shelf life. .

That is, when a liquid product is obtained by blending 1 to 40 qb of soap with a known dispersant, the viscosity increases due to a gelation phenomenon after about 2 months from the time of blending, and after about 5 months, it gels into a pudding-like state and becomes a liquid. It ceases to be a thing.

When preparing a magnetic powder liquid using a dispersant for magnetic powder liquid, the usual method is to first thoroughly mix a predetermined amount of a dispersant for magnetic powder liquid with a predetermined amount of magnetic powder, and then: This mixture is poured into a predetermined amount of water and stirred to obtain a magnetic powder liquid having a concentration of dispersant for magnetic powder liquid of 1 to 3%/14% of water and a magnetic powder concentration of 1 to 3f/14% of water. The reason why such an embodiment is adopted is that in order to fully exhibit the performance of the dispersant for magnetic powder liquid, it is preferable to attach the dispersant to each grain of magnetic powder.

Therefore, the dispersant for magnetic powder liquid must be in a liquid state at the time of use, and if it is in a pudding-like state at the time of use, it may be difficult to mix it with the magnetic powder when preparing the magnetic powder liquid according to the above embodiment. This causes problems and makes it extremely difficult to attach the dispersant to each grain of magnetic powder.

However, it is possible to make a liquid by adding an appropriate amount of water to the pudding-like dispersant for magnetic powder liquid and stirring well. However, in this case, extremely complicated weighing work is required to obtain the desired concentrations of the dispersant and magnetic powder in the magnetic powder liquid, and the on-site workers are required to perform such complicated weighing work. The current situation is that this is almost impossible.

The present inventor has conducted repeated research with the aim of providing a dispersant for magnetic powder liquid that can be used at high temperatures and remains liquid for at least one year after production and does not form a pudding-like product.

When a soap with a rating of 1 to 40 is added to a known dispersant and a specific amount of alcohol is added,
It has been found that it is possible to completely prevent the formation of a pudding-like product for at least one year after production, and that it does not have any adverse effects on the above-mentioned conditions (1) to (3) at high temperatures.

To comment, the present inventor first applied a known dispersant with a concentration of 1 to 40
As a result of investigating the factors that cause the liquid to change over time into a pudding-like substance when % of soap is mixed, silicon antifoaming agents and water are gradually incorporated into the micellar lattices of the soap in the liquid. I learned that this phenomenon was the cause.

Considering that this phenomenon is unavoidable when using soap, we investigated a number of additives with the aim of suppressing this phenomenon. Although it is impossible to completely avoid the occurrence of this, it is possible to delay its progression as much as possible. However, the present invention was completed by confirming that the presence of a specific amount of alcohol does not adversely affect the above-mentioned items (1) to (3) at high temperatures.

That is, the present invention has a T-TLB value of 10 to 11 and a pixel of 40°C.
1-3% silicone antifoaming agent made of dimethylpolysiloxane oil as oil-in-water emulsilone using polyethylene glyco-/I/type nonionic surfactant,) polyethylene with a TLE value of 10-13 and a point of view of 50°C or less Glycol type nonionic surfactant 2-6%, soap 1-40%,
Dispersant for magnetic powder liquid used in wet magnetic particle flaw detection method consisting of 0.5 to 25% alcohol and balance water and RLE value lO~1
1 to 3% silicone antifoaming agent made by forming an oil-in-water emulsion of dimethylpolysiloxane oil using a polyethylene glycol type nonionic surfactant with an image point of 40°C;
]-TLB value 10 N13 and goldfish 50℃ or less polyethylene glyco-)vIJ nonionic 4 liters activator 2 to 6 liters,
Dimethylpolysiloxane-polyoxyalkylene copolymer (however, the number of moles of ethylene group is 5 moles or less) 0.1 to 0
．． 5%, soap 1-40%, alcohol 0.5-25
This is a dispersant for magnetic powder liquid used in the wet magnetic particle flaw detection method (hereinafter, these are referred to as improved dispersants), which consists of 1%, the balance being water.

The most characteristic feature of the present invention is that when adding soap to the above-mentioned formulation of a known dispersant, alcohol/L/Q
, 5 to 25% (In addition, in formulations containing alcohol, the "remaining water" is obtained by subtracting an amount of water commensurate with the amount of alcohol blended.).

The amount of alcohol added is important, at least 0.5%
It will not be effective unless the above ingredients are combined. A content of 25% or more must be avoided since there is a risk that the oil-in-water emulsion of the silicone antifoaming agent in the formulation will be destroyed and a portion of the dimethylpolysiloxane oil will separate from the water. Therefore, the amount of Alco-A/ added is selected within the range of 0.5 to 25 inches.

As the alcohol, monohydric alcohols such as methanol, ethanol, n-propyl alcohol, and isopropyl alcohol, ethylene glycol, propylene glycol, hexylene glycol, l-iV, and the like (D polyhydric alcohols) are used.

In addition, the soap in the present invention includes sodium laurate (CI, ]-T, C00Na), sodium mystate (C13%COONa), sodium palmitate (Cl51T3.cOONa) 1,2. Sodium thearate (0m7]-T35cooNa,)
, sodium oleate (C1□T-T35COONa
) and sodium beef tallow fatty acid (NEi Sorg: Product name:
Kao Soap Co., Ltd.) and other sodium soaps, potassium laurate (C□-COOK), potassium myristic acid (C, FT Cook (L), potassium palmitate (015H3,0OOK), potassium stearate (C
,, H, 5GOOK), potassium ionate (cl, H
3, cooK), beef tallow fatty acid potassium (FR-14: product name: manufactured by Kao Soap Co., Ltd.) and mustard oil potassium (FR
-25: Brand name: Potassium soap such as Kao Soap (manufactured by Kiki) is used.

The formulation of the improved dispersant according to the present invention is exactly the same as that of the above-mentioned known dispersant, except for the addition of alcohol and venison.

), as in the case of known dispersants, add 3 to 5% of a rust preventive agent such as sodium nitrite or triethanolamine as necessary.
It can be added within the following range.

The method for producing the improved dispersant is extremely easy, and the desired product can be obtained by mixing and stirring predetermined amounts of each compound. While mixing and stirring, it is desirable to heat the soap to about 50° to 70°C in order to dissolve it in a short time, and
In this case, it is desirable to mix and stir each of the formulations except for the silicone antifoaming agent under heating, then cool to room temperature, and then mix and stir the silicone antifoaming agent.

The improved dispersant obtained as described above is a liquid,
It is guaranteed that it will remain liquid and not turn into a pudding-like product for at least one year after production.

The method for using the improved dispersant is exactly the same as that for known dispersants. Add 1 to 3 g of magnetic powder to water to which the improved dispersant has been added at a concentration of 1 to 3%/11 parts of water. Prepare a magnetic powder solution by adding 1 portion to concentrated water. This magnetic powder liquid can be used not only when the liquid temperature is 20'' to 30℃, but also when the liquid temperature is 40℃.
Even when the liquid temperature exceeds 40°C, it satisfies the requirements of (1) and (2) above up to about 50"C, ensuring that sufficient flaw detection accuracy can be obtained for practical use, and even when the liquid temperature exceeds 40"C
℃ for about 10 to 20 hours after the start of use [dimethylpolysiloxane-polyoxyalkylene copolymer is 0.1 to 0.
．． A formulation containing 5% is guaranteed to maintain the antifoaming effect for 40 to 50 hours. It should be noted that there is almost no possibility that the temperature of the magnetic particle liquid will exceed approximately 50'C, and if it exceeds 50T-, the wet magnetic particle testing method itself may become impossible due to burns on the inspector. It becomes possible.

Unfortunately, it has not been possible to theoretically elucidate the effect of adding alcohol in the present invention, but the effect is remarkable as seen in the Examples below.

Regarding the effect of adding soap in the present invention, the soap does not have a cloud point and remains dissolved even when the liquid temperature exceeds 40°C. The above-mentioned RI and B values of 10 to 11, which occur when the liquid temperature exceeds 40°C, allow for the ultimate separation between goldfish polyethylene glyco-μ type nonionic surfactants, water, and dimethylpolysiloxane oil below 40°C. It is assumed that the foaming of the soap itself, which is being dissolved at the same time, is suppressed by the presence of the silicone antifoaming agent.

Next, the structure and effects of the present invention will be explained using Examples and Comparative Examples.

Example 1゜〈Formulation) ■ Silimono antifoaming agent KM-68-IF (product name: Shin-Etsu Chemical Co., Ltd.) 3% ■ Polyoxyethylene nonylphenyl ether (3 moy
Ht additive) TTLB 6.1, image point lO℃ or less 1%
Polyoxyethylene lauryl ether) V (6.5 mole adduct) HLE 11.6 @ point 38°C 4% ■ Sodium myrinutate 10% ■ Sodium nitrite 5% ■ n -propyl alcohol ■ Water 75% First, ■ ~ (2) was mixed and thoroughly stirred while heated to 60''C, then cooled to room temperature (24''C), (2) was added and stirred to obtain an improved dispersant in the form of a translucent cane.

The viscosity of the improved dispersant obtained above immediately after production, 2 months later, and 1 year later were measured using a B-type viscometer (manufactured by Tokyo Keiki Seisakusho Co., Ltd.). 16 each
5cp (24'C), 1670p (24'C) and 17
5cp (at 24°C), and it was confirmed that it remained liquid even one year after its manufacture.

For comparison, we used a comparative formulation in which ■ was removed and ■ was 77 tons in the above formulation, and the viscosity immediately after production, the viscosity after 2 months, and the viscosity after 3 months were obtained by the same operation as above. When measured in the same manner as above, it was 206cp (21'c) immediately after manufacture, and 430c1 after 2 months.
11 (24'C:), and after 3 months it turned into a pudding-like substance, and because it was not liquid, it was impossible to measure the viscosity.

<Preparation of magnetic powder liquid> And! Improved dispersant obtained approximately 1 year after production 60
0 CQ and 120 g of fluorescent magnetic powder are mixed well, and this mixture is poured into tank 1 (volume: 1 ook) shown in Fig. 1, which contains water bO (l), and the concentration of the improved dispersant is 1. A magnetic powder solution having a magnetic powder concentration of 247/1 l was prepared using 14% of water/water.

<Implementation of Wet Magnetic Particle Detection Method> Pump 2 in Figure 1 is operated, the magnetic particle liquid is circulated as indicated by the arrow in the figure, and while the magnetic particle liquid is maintained at approximately 40'C, the depth Q. A medium-65 low-strength raw steel square billet with a defect of 88aj was used as the inspection object A, and the shaft energization method DC-1 00OA was used.
Electricity is applied under the following conditions to spread the magnetic powder liquid, and the flaw detection accuracy at each point of time, 95 minutes, 8 hours, and after a hill time from the start of circulation of the magnetic particle liquid, is visually judged under black light irradiation.

As a result, defects can be clearly observed at any time point, and even at a liquid temperature of about 40'C, the magnetic particles in the magnetic powder liquid are
It was determined that the particles were sufficiently dispersed not only after minutes but also after L hours.

Furthermore, even 12 hours after the start of circulation of the magnetic powder liquid, there were no bubbles coming from the top of the tank 1, indicating that the antifoaming effect was maintained sufficiently at the liquid temperature of about 40°C. I was able to determine.

Example 2.

<Formulation> ■Sirimono antifoaming agent KM-7 2F (Product name: Shin-Etsu Chemical (water sampling) 1 t ■Polyoxyethylene nonyl phenyl ether (5 mole adduct)) TLB 10.0 Cloud point 1
Below 0°C 1.8% polyoxyethylene dovanol ether) IL/(4.5 mol adduct) Ding JLB 10.7
Iku 1 (point 501=n 4.2% ■ Sodium nitrite 5
(1) Ethanol 23% (2) Water 64% According to the above recipe, a translucent improved dispersant was obtained by the same operation as in Example 1.

The viscosity of the improved dispersant obtained in and ~ immediately after production, 2 months later, and 1 year later were measured in the same manner as in Example 1, and the results were 140 Qp (24°C) and 14! Iap(2
Cc) and 154cp (24''C), and it was confirmed that it remained liquid even one year after production.

For comparison, we used a comparative formulation in which ■ in the above formulation was removed and ■ was 87%, and the viscosity immediately after production, the viscosity after 2 months, and the viscosity after 6 months were obtained by the same operation as above. When measured in the same manner as above, it was 182Qp (24'C) immediately after manufacture, and 18cp (24'C) after two months.
), and after 5 months it turned into a pudding-like substance, and since it was not liquid, it was impossible to measure the viscosity with a B-type viscometer.

[Preparation of magnetic powder liquid] was carried out in exactly the same manner as in Example 1, using the improved dispersant obtained in 1 and 1 year after production.
A wet magnetic particle flaw detection method was carried out in the same manner as in Example 1, except that the magnetic particle liquid was used and the temperature of the magnetic particle liquid was maintained at 42'C.

As a result, as in Example 1, defects could be clearly observed at any time, and even at a liquid temperature of approximately 42'C, the magnetic particles in the magnetic powder liquid remained sufficiently dispersed even after 12 hours. It can be determined that there is.

Furthermore, even 12 hours after the start of circulation of the magnetic powder liquid, there were no bubbles overflowing from the top of tank 1, and about 4
It was determined that sufficient antifoaming effect was maintained at a liquid temperature of 2'C.

Example 3゜〈Prescription) ■ Silicone antifoaming agent KM-7o (Product name: Shin-Etsu Chemical C Co. 12% ■ Polyoxyethylene nonylphenyl ether (
85 mole adduct) HLB 12.6 Goldfish 44 in 2
91S ■Sodium nitrite 3% ■Water 5o, 8% According to the above formulation, a translucent improved dispersant was obtained by the same operation as in Example 1.

The viscosity of the improved dispersant obtained in Example 1 was measured in the same manner as in Example 1, immediately after production, 2 months later, and 1 year later.
4'c) and 251cp (24'C), and after production 1
It was confirmed that it remained liquid even after several years.

For comparison, we used a comparative formulation in which (■) was removed from the above formulation and (■) was changed to 6 o and 8 o, and the viscosity immediately after production, 2 months later, and 3 The viscosity after 2 months was measured in the same manner as above, and it was 2 boap (24'c) immediately after manufacture and 600 cp after 2 months.
(24'c), and after 6 months it had become a pudding-like substance, and because it was not liquid, it was impossible to measure the viscosity with a B-type viscometer.

Using the improved dispersant that has been produced for about one year, a magnetic powder liquid was prepared in exactly the same manner as in Example 1.
The same procedure as in Example 1 was carried out (wet magnetic particle flaw detection method) except that the magnetic particle liquid was used and the temperature of the magnetic particle liquid was maintained at 42°C.

As a result, as in Example 1, defects can be clearly observed at any time, and even at a liquid temperature of about 42°C, the magnetic particles in the magnetic powder liquid remain sufficiently dispersed even after 50 hours. I was able to determine that.

Furthermore, even 50 hours after the start of circulation of the magnetic powder liquid, there were no bubbles coming up from the top of the tank 1, and a sufficient antifoaming effect was maintained at a liquid temperature of approximately 42°C. I was able to determine that.

In addition, each silicone antifoaming agent used in Examples 1 to 3 was
All dimethylpolysiloxane oils are oil-in-water using a polyethylene glycol type nonionic surfactant with an HLB value of 11)-IL and 40"C or less, which is considered to be the optimal antifoaming agent for use in dispersants for magnetic powder liquids. A commercially available silicone antifoaming agent in the form of a type emulsion, containing 10-30% dimethylpolysiloxane oil and 5-10% surfactant.
, the balance is the blending ratio of water.

[Brief explanation of the drawing]

FIG. 1 is a partially vertical cross-sectional explanatory view showing a magnetic powder liquid stirring device commonly used in wet magnetic flaw detection. In the figure, 1 is a tank, 2 is a pump, and 8 is an object to be inspected. Note that the arrows in the figure indicate the circulation system path of the magnetic powder liquid. Patent Applicant Special Paint Co., Ltd. Procedural Amendment (Spontaneous) December 4, 1980 Director General of the Patent Office Mr. 1, Indication of Case 1982 Patent Application No. 215108 Z Name of Invention Magnetic Powder Liquid Used in Wet Magnetic Flaw Detection Dispersant for use 3, relationship with the case of the person making the amendment Patent applicant (1) Scope of claims column (2) Detailed explanation of the invention in the specification column 5, Contents of amendment (1) ); As shown in the attached sheet, regarding (2); A. Correct "magnetic particle detector" on page 2, line 7 of the 8A specification to "magnetic detector." B. Insert ``below'' between ``40℃'' and ``nopo'' on page 21, line 7 of the specification. "Magnetic particle detector" on line 14 of the same page of the C0 specification will be corrected to "magnetic detector." Insert "below" between "40℃" and "nobo" on line 15 of the same page of the specification. E. Correct "magnetic particle detector" in line 5 of page 22 of the specification to "magnetic detector." F. Correct "powder" to "ki" on page 25, line 15 of the statement. G, II Detailed Oath, page 28, line 14, "powder" is corrected to "ki". The word "powder" in line 4 of page 51 of the H9 specification was corrected to "ki". Engineering, I will correct "powder" in line 6 on page 33 of the specification to "ki". Above 6, list of attached documents Paper 1 Attached paper: 1 to 3% by weight silicone defoaming agent made from dimethylpolysiloxane oil as an oil-in-water emulsion using an L' type nonionic surfactant, ELB value 1O ~ 13, goldfish 50℃ or less polyethylene glycol type nonionic surfactant 2-6% by weight, soap 1-40% by weight, alcohol
/110.5 to 25% by weight, the balance being water Silimono antifoaming agent 1-1 made of dimethylpolysiloxane oil as an oil-in-water emulsion using a magnetic coal-type nonionic surfactant used in wet magnetic flaw detection Mie Keichi, I-TLB
[1 (l) 2 to 6% by weight of polyethylene glycol type nonionic surfactant with a temperature of 50°C or less at N13, dimethylpolysiloxane-polyoxyalkylene copolymer (however,
Number of moles of ethylene group: 5 moles or less) 0.1 to 0.5% by weight
, Sec Weight to 40 Weight Section, Alco-/110.5~2
A dispersant for magnetic powder liquid used in wet magnetic flaw detection, consisting of 5% by weight and the balance water.

Claims (2)

[Claims] (1) Silicone antifoaming agent 1-3 made by converting dimethylpolysiloxane oil into an oil-in-water emulsion using a polyethylene glycol-type nonionic surfactant with an HLB value of 10-11 and a cloud point of 40°C, HLB value of 1O- 13, polyethylene glycol type nonionic surfactant with a cloud point of 50°C or less, 2 to 6 parts by weight, soap 1 to 401 parts, alcohol/110.5 to 25% by weight, balance water for wet magnetic particle flaw detection. Dispersant used for magnetic powder liquid. (2) Nr, B value 1 (1 to 11 using a polyethylene glycol type nonionic surfactant with a cloud point of 40°C) silicone antifoaming agent 1 made by forming an oil-in-water emulsion with a v-long siloxane oil 3% by weight, HLB value 10-1
2 to 6% by weight of a polyethylene glyco-7 type nonionic surfactant with a cloud point of 50″C or less, and a dimethylpolysiloxane-polyoxyalkylene copolymer (however, the number of ethylene groups is 5 moles or less) o, i~[1,5fii poly, soap 1~40ffiti%, alcohol 0,5~25
A dispersant for magnetic powder liquid used in wet magnetic particle testing, consisting of % by weight and the balance being water.