JPH07181268A - Method for discriminating asbestos easily - Google Patents

Abstract

PURPOSE:To rapidly and purely discriminate the presence or absence of asbestos in a fiber reinforcing material by physically crushing the fiber reinforcing material and then loading the crushed powder on a slide glass, dripping the crushed powder and a dipped liquid with a specific refractive index and then placing a cover glass as a sample, and then observing light through the sample from a light source via a dispersion dyeing lens. CONSTITUTION:The presence or absence of asbestos is judged by the dispersion dyeing method using a crushed powder obtained by crushing the sample of a fiber reinforcing material. First, for judging the presence or absence of the asbestos by mounting the crushed powder on a slide glass, a dipping liquid with the refractive index being within the range of 1.550+ or -0.010 is dropped and further a sample obtained by placing the cover glass is observed by a microscope with a light source, a rotary stage, and a dispersion dyeing lens by the dispersion dying method. Light through the sample from the light source is observed via a lens. Then, when a peripheral part alternately repeats red- orange color and blue color for two times as the rotary stage is rotated by one turn, asbestos are detected and discriminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for quickly and easily determining the presence or absence of asbestos in a fiber reinforced material such as a building material or a heat insulating material.

[0002]

2. Description of the Related Art Asbestos is a fiber having excellent properties and has been widely used in various fields such as building materials and heat insulating materials. However, recently, the effect of asbestos on health has come to be often discussed, and asbestos is progressing accordingly.

Therefore, there is a need for a method for quickly and easily determining the presence or absence of asbestos in a product that has been used or is about to be used. Generally, the X-ray diffraction method is used as a method for determining the presence or absence of asbestos in the product, but it requires a large-scale device and requires qualified personnel to be selected as the X-ray operation chief. For example, there are some cases that do not meet the above purpose.

Therefore, the present inventors have already applied for a technique capable of quickly and easily determining the presence or absence of amosite asbestos in the calcium silicate heat insulating material (Japanese Patent Laid-Open No. 215748/1993). However, this technique is effective only for calcium silicate heat insulating materials, and cannot be applied to other building materials and heat insulating materials containing asbestos.

In recent years, a dispersion dyeing method has been proposed as a method for identifying asbestos (for example, Clay Science Vol. 32, Vol. 1).
42-52: 1992). In this method, a shielding plate is placed in the center of the back focal plane of the objective lens of the microscope, direct light is cut, and a colored contour appears on the peripheral edge of the crystal due to light that has passed through other than the center of the back focal plane. Is a method of identifying asbestos by coloring a sample by a physical method using a disperse dyeing lens characterized by. Since it is determined whether or not asbestos is based on color, it is relatively easy to determine whether or not a certain fibrous substance is asbestos without particular proficiency in observation technology.

[0006]

However, the asbestos identification technology by the disperse dyeing method that has been proposed so far is mainly a method of determining whether or not a certain fiber substance is asbestos, and mainly It has been proposed as a method for measuring asbestos in airborne dust. On the other hand, since the fiber reinforcing material is a composite material of the fiber material and the matrix material, the surface of the fiber material is adhered to the matrix material, and it is not always possible to make the same discrimination as in the case of identifying only the fiber. About the presence or absence of asbestos in the fiber reinforcement,
Nothing is disclosed about a concrete method to be performed quickly and easily.

[0007] Further, the above "clay science" describes that fiber gypsum and chrysotile asbestos can be distinguished from each other in a gypsum board by a polarization microscope. However, the presence or absence of asbestos in the gypsum board using the disperse dyeing method. There is no disclosure of a specific method for quickly and easily discriminating.

As a method for separating fibers and a matrix, for example, in the Asbestos test (ASBESTEST: manufactured by EA Aperatorus Corporation), which is a method for determining asbestos by chemical analysis, both the matrix of the cement material and the calcium silicate material are alkaline. That is, the matrix substance is removed by treating the sample with a weak acid. However, weak acid treatment cannot be carried out quickly because it takes time. Further, asbestos is not so strong against acid, and there is a risk that asbestos will be decomposed and the optical properties will be changed by the treatment with acid. Further, the acid treatment has a drawback that it cannot be applied unless the matrix substance is alkaline.

Accordingly, it is an object of the present invention to provide a method for quickly and easily determining the presence or absence of asbestos in a fiber reinforcing material such as a building material or a heat insulating material.

[0010]

Means for Solving the Problems As a result of intensive research to solve the above-mentioned problems, the present inventors have found that asbestos and matrix substance are adhered to each other in the fiber reinforcing material, but asbestos is an assembly of ultrafine fibers. It is a fiber bundle, and if it is physically crushed, it not only separates at the interface between the asbestos and the matrix substance, but also if the asbestos-matrix substance adheres strongly, the asbestos bundle becomes parallel to the fiber direction. Focusing on the fact that it becomes possible to quickly and easily obtain the fiber surface on which the matrix substance is not adhered because it is disintegrated into fine fibers, and the fiber reinforcing material for determining the presence or absence of asbestos as it is, or A part of it is taken, and the crushed powder obtained by physically crushing it is placed on a slide glass, a specific immersion liquid is dropped, and a glass cover is applied to make a test piece. In the sample Most of the cotton is in a state where at least a part thereof is not attached to the matrix substance, and the fiber substance in the specimen has its fiber direction substantially parallel to the surfaces of the slide glass and the cover glass. Finding that it can be determined in the same way as determining,
The present invention has been completed.

That is, the method for simply determining the presence or absence of asbestos fibers in the fiber reinforcement of the present invention is characterized by comprising the following three steps: The fiber reinforcement to be discriminated is physically ground. After that, the first step of taking the crushed powder on the slide glass; the second step of dropping an immersion liquid having a specific refractive index onto the crushed powder on the slide glass, and placing the cover glass on it as a specimen; and a light source, The specimen obtained in the second step is mounted on a rotating stage of a microscope including a rotating stage and a disperse dyeing lens, and light passing through the specimen from a light source is observed through the disperse dyeing lens, A fibrous substance that repeats physical coloring of reddish orange and blue or blue and reddish orange alternately as the rotary stage rotates in one direction is determined to be asbestos.
Process.

[0012]

According to the method of the present invention, the presence or absence of asbestos fibers in the fiber reinforcing material is easily determined by using the disperse dyeing method. Here, asbestos that has been used as an industrial raw material such as building materials includes three types: chrysotile asbestos, amosite asbestos, and crocidolite asbestos (blue asbestos). Crocidolite asbestos has a unique blue color, and if it is used in a small amount, it is easy to visually identify it. Therefore, it is only necessary to establish a method capable of quickly and easily determining the presence or absence of chrysotile asbestos and amosite asbestos.

That is, if the fibers in the fiber reinforcement can be separated and taken out from the matrix, it is possible to determine whether or not the fibers are asbestos by the known dispersion dyeing technique. Therefore, the present inventors have noted that asbestos is a fiber bundle in which ultrafine fibers are assembled. In the fiber reinforcement, asbestos and matrix material are attached,
If this is physically crushed (e.g., impact crushing), not only the asbestos-matrix material is separated at the boundary surface, but even if the asbestos-matrix material is strongly attached, the asbestos bundle is parallel to the fiber direction. Since the fibers are defibrated into various fine fibers, it becomes possible to quickly and easily obtain a fiber surface to which the matrix substance is not attached.

Next, the presence or absence of asbestos is determined by the disperse dyeing method using the crushed powder obtained by crushing the sample of the fiber reinforcing material.
First, crushed powder is placed on a glass slide and the refractive index of 1.550 ± 0.0 is used to determine the presence or absence of chrysotile asbestos.
In order to determine the presence or absence of amosite asbestos by dropping the immersion liquid in the range of 10, the refractive index is 1.680 ± 0.01
An immersion liquid in the range of 0 is dropped, and a test piece obtained by further mounting a cover glass is observed by a disperse dyeing method using a light source, a rotating stage, and a microscope equipped with a disperse dyeing lens.

The observation was carried out by mounting the test piece on a rotary stage,
The light passing through the specimen from the light source is observed through the disperse dyeing lens, and as the rotary stage is rotated once (360 °), it is a substance having a fiber shape, and its peripheral portion becomes reddish orange and blue (or Asbestos is identified as one that develops color by alternately repeating red (orange and blue) twice. When the asbestos fibers are thin, the entire fibers develop color as described above.
Further, it is desirable that the light entering the sample from the light source be linearly polarized light. For this purpose, for example, a polarizing filter may be attached between the light source and the sample.

Here, as the immersion liquid having a refractive index within the range of 1.550 ± 0.01, for example, a mixture of clove oil and cassia oil can be used, and the refractive index is 1. As the immersion liquid in the range of 680 ± 0.01, for example, a mixture of α-monobromnaphthalene and methylene iodide can be used. If the refractive index of the immersion liquid does not fall within the above range, the color development conditions change, making it difficult to correctly identify asbestos.

Further, a microscope equipped with a light source used in the method of the present invention, a rotary stage, and a disperse dyeing lens usually uses a disperse dyeing lens as an objective lens and uses it in combination with an eyepiece lens. Therefore, since a particularly large-scale device is not necessary, it is easy to discriminate the fiber reinforcing material at the construction site or the manufacturing site, if necessary. A halogen lamp or the like can be used as the light source. The magnification at the time of observation is not particularly limited, but usually 50 to 200 times is suitable.

Since the method of the present invention discriminates whether or not it is asbestos by the color developed by the dispersion dyeing method, anyone can easily discriminate it. However, the matrix material is not suitable for materials such as rubber that are difficult to physically grind.

When the crushed powder obtained by simply crushing the sample as described above is taken on the slide glass, the crushed powder having a large particle size, that is, which makes it difficult to distinguish asbestos by the dispersion dyeing method, is present in the specimen. May be included. In such a case, the pulverized powder is dispersed in the dispersion liquid, only the floating powder is taken on a slide glass, the dispersion liquid is evaporated, the immersion liquid is dropped, and a specimen is prepared. Can be obtained. The dispersion is preferably one that does not adversely affect the asbestos fibers and can be quickly evaporated, and alcohols and the like are suitable.

[0020]

【Example】

Example 1 Approximately 1 g of calcium silicate heat insulating material about 20 years after construction
Was crushed in an agate mortar, about half of the crushed powder was picked up on an earpick on a slide glass, and α-monobromnaphthalene and methylene iodide were mixed at a ratio of 3: 1 as an immersion liquid (refractive index = 1.680). Was dropped, and after mixing with pulverized powder, a glass cover was put on it to obtain a sample. A polarizing plate is attached between the light source of the microscope and the rotating stage, and the light emitted from the light source is linearly polarized, and then the test piece is attached on the rotating stage.
Using a disperse dyeing lens with a magnification of 10 times as an objective lens and an eyepiece lens with a magnification of 10 times, the specimen is kept at room temperature (about 20
3 fields of view were observed. As a result, with the rotation of the rotating stage, several red-orange and blue fibers were alternately observed in each visual field. Further, as a dipping solution, clove oil and cassia oil were mixed in a ratio of 3: 1 (refractive index = 1.55
When a test piece was prepared by using (0), no fibers were observed in which reddish orange and blue were alternately colored. Therefore, for this calcium silicate heat insulating material sample, it was determined that amosite asbestos was used and chrysotile asbestos was not used. Although all the operations were performed by one person, the time required during this was about 15 minutes. Next, when the calcium silicate heat insulating material sample was subjected to a qualitative analysis by an X-ray diffraction method, an amosite asbestos diffraction peak was observed, but a chrysotile asbestos diffraction peak was not observed.

Example 2 The calcium silicate heat insulating material manufactured and constructed last year was observed by the same method as in Example 1. However, the number of observation visual fields was set to 5. As a result, no fibers were observed in which reddish orange and blue were alternately colored. Therefore, it was determined that asbestos was not used in this calcium silicate heat insulating material sample. Next, when the calcium silicate heat insulating material sample was subjected to qualitative analysis by an X-ray diffraction method, no asbestos diffraction peak was observed.

Example 3 A corrugated slate whose manufacturing and construction dates were unknown was observed by the same method as in Example 1. As a result, when a mixture of α-monobromnaphthalene and methylene iodide in a ratio of 3: 1 (refractive index = 1.680) was used as the immersion liquid, fibers that alternately developed reddish orange and blue were produced. Was not recognized. Next, when a test piece was prepared using a mixture of clove oil and cassia oil in a ratio of 3: 1 (refractive index = 1.550) as an immersion liquid, slightly reddish orange and blue were alternately formed. Fiber was observed. From the above results, it seems that for this slate sample, amosite asbestos was not used, but chrysotile asbestos was used, but the color-developing fibers were covered by the matrix, making it very difficult to observe. Met.

Then, about 2 g of the slate was taken and crushed, and then the crushed powder was dispersed in an alcohol liquid, the floating powder content was taken on a slide glass, the alcohol content was evaporated, and the test sample was prepared in the same manner as described above. Was prepared and observed.
As a result, as an immersion liquid, a mixture of α-monobromnaphthalene and methylene iodide in a ratio of 3: 1 (refractive index = 1.68)
When 0) was used, no fibers were observed in which the color was alternately changed between reddish orange and blue. Next, as an immersion liquid, clove oil and cassia oil were mixed in a ratio of 3: 1 (refractive index =
1.550) was used to fabricate a test piece, and fibers in which clear red-orange and blue were alternately developed were observed. From the above results, it was revealed that amosite asbestos was not used and chrysotile asbestos was used for this slate sample. In addition, once dispersed in an alcoholic liquid and producing a test piece from the suspended powder, it was possible to confirm the fibers that clearly developed color, without the fibers that developed color being covered by the matrix. Next, when a qualitative analysis by an X-ray diffraction method was performed on this slate sample, a diffraction peak of chrysotile asbestos was observed,
No diffraction peak of amosite asbestos was observed.

Example 4 Approximately 2 g of calcium silicate plate of unknown manufacturing and construction date was taken and crushed, and then crushed powder was dispersed in alcohol liquid,
After the floating powder component was taken on a slide glass and the alcohol component was evaporated, a test sample was prepared and observed in the same manner as above. As a result, a sample prepared by mixing α-monobromnaphthalene and methylene iodide in a ratio of 3: 1 (refractive index = 1.680) was used as an immersion liquid, and clove oil and cassia oil were used as an immersion liquid in a ratio of 3: 1: Compounded to 1 (refractive index = 1.
In the test piece using 550), fibers that alternately developed reddish orange and blue were observed. Therefore, it was determined that chrysotile asbestos and amosite asbestos were used in this calcium silicate plate sample. Next, when the slate sample was subjected to a qualitative analysis by an X-ray diffraction method, diffraction peaks of amosite asbestos and chrysotile asbestos were observed.

[0025]

By using the method of the present invention, anyone can quickly and easily determine the presence or absence of asbestos in a fiber reinforcement such as a building material or a heat insulating material. Further, since a large-scale measuring device is not necessary, it is possible to make a discrimination at the construction site or the production site of the fiber reinforcing material as required.

Front page continuation (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location G01N 21/41 Z (72) Inventor Norito Akiyama 2-5-5 Tsurumi Chuo, Tsurumi-ku, Yokohama-shi, Kanagawa Stock Company Ask

Claims (3)

[Claims] 1. A method for easily determining the presence or absence of asbestos fibers in a fiber reinforcement, which comprises the following three steps: a simple method for determining asbestos: The fiber reinforcement to be identified is physically First step of crushing the powder on the slide glass after crushing the powder, and a second step of dropping an immersion liquid having a specific refractive index onto the crushed powder on the slide glass and placing a cover glass on the slide glass to obtain a specimen. Also, the sample obtained in the second step is mounted on the rotating stage of a microscope equipped with a light source, a rotating stage, and a disperse dyeing lens, and the light passing through the sample from the light source is passed through the disperse dyeing lens. Observing and discriminating asbestos a fibrous substance that alternately repeats physical coloring of reddish orange and blue or blue and reddish orange as the rotating stage rotates in one direction.
Process. 2. The asbestos according to claim 1, wherein in the first step, the pulverized powder that is physically pulverized is dispersed in a dispersion liquid, and only the pulverized powder floating on the surface of the obtained dispersion liquid is taken on a slide glass. Simple determination method of. 3. In the second step, when the chrysotile asbestos is used as the immersion liquid, the refractive index is 1.550 ± 0.5.
The simple determination method of asbestos according to claim 1, wherein when amosite asbestos is discriminated by using the one in the range of 010, the one having a refractive index in the range of 1.680 ± 0.010 is used.