JPH0413687B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an immersion oil for microscopes, and more particularly to an immersion oil that is sometimes suitable as an immersion oil for fluorescence microscopes. One method of increasing the magnification of a microscope is the immersion method, which increases the numerical aperture of an objective lens. Immersion oils used in this case include glycerin, silicone oil, and polychlorinated biphenyl (PCB).
(hereinafter referred to as PCB oil) are known. However, glycerin is hygroscopic and has a low refractive index, while silicone oil has a high viscosity and a low refractive index. Additionally, PCB oil has the serious drawback of being harmful to the human body. The applicant has developed a mixture of a specific chain hydrocarbon and diphenylmethane as an immersion oil for microscopes that does not have the above-mentioned drawbacks. It is unsuitable as an immersion oil. Therefore, the present inventor has proposed that there is no drawback as mentioned above,
Moreover, as a result of repeated studies to develop an immersion oil that suppresses the generation of fluorescence as much as possible, we discovered that it is effective to use a liquid diene polymer as a base oil and blend a specific compound with it. The present invention was completed based on this knowledge. That is, the present invention provides a microscope comprising a liquid diene polymer mixed with at least one compound selected from a liquid olefin polymer, a liquid saturated hydrocarbon, an aliphatic saturated alcohol, and an alicyclic alcohol. It provides immersion oil for use. The liquid diene polymer used in the present invention includes polybutadiene, polyisoprene, polychloroprene, etc., and those having a molecular weight of about 500 to 20,000 are preferable. Among these, polybutadiene is particularly preferred. These liquid diene polymers may have functional groups such as hydroxyl groups and carboxyl groups. Next, among the compounds to be added to the liquid diene polymer, liquid olefin polymers include polyethylene, polypropylene, polybutene, polyisobutylene, etc., and those having a molecular weight of 500 to 20,000 are preferred. Various liquid saturated hydrocarbons can be used, including pentane, hexane, hebutane,
Preferred are octane, nonane, liquid paraffin, and the like. In addition, aliphatic saturated alcohols include methanol, ethanol, propanol, butanol,
Pentanol, hexanol, heptanol, octanol, etc. are preferably used. Aliphatic cyclic alcohols include cyclobutanol, cyclopentanol, cyclohexanol, cycloheptanol, cyclooctanol, cyclobutenol, cyclopentenol, cyclohexenol,
Examples include cycloheptenol, cyclooctenol, dicyclopentanol, dicyclohexanol, dicyclopentenol, and dicyclohexenol. In the present invention, these compounds may be used alone or in combination of two or more.
In addition to these compounds, as desired components,
Esters may also be used, in particular saturated or unsaturated carboxylic acid esters (e.g. methyl acetate, ethyl acetate, dicyclopentyl acetate,
methyl maleate, ethyl maleate, methyl fumarate, ethyl fumarate, etc.) and glycerin esters (triesters, diesters, monoesters), etc. When blending the liquid diene polymer with the above-mentioned compounds, care should be taken so that properties such as light dispersibility, refractive index, and viscosity are appropriate for an immersion oil. First, the appropriate range of light dispersion indicated by the Atsube number is 40 to 58, and the appropriate refractive index is 1.4 to 1.6. Furthermore, the viscosity is 10~50000cSt (37.8℃), preferably 20~
It should be 10000cSt (37.8℃). Other properties required of immersion oil include good non-drying properties, low fluorescence, weather resistance, corrosion resistance, transparency, resolution, and chromatic aberration. In order to satisfy the above required performance, 10 to 97 parts by weight of the liquid diene polymer, preferably 30 to 95 parts by weight, and 3 to 90 parts by weight, preferably 5 to 70 parts by weight of the above compound are blended. In order to prepare the immersion oil for microscopes of the present invention, the above components may be blended and thoroughly mixed while stirring at a temperature of 10 to 100°C. The immersion oil of the present invention satisfies all of the above-mentioned required performances and is not toxic to the human body.
Furthermore, since it generates less fluorescence than conventional immersion oil, it is suitable for use in a fluorescence microscope. Next, examples of the present invention will be shown. Examples 1 to 7 A liquid diene polymer and a specified compound were blended in a specified ratio (parts by weight), and the mixture was heated at 50°C in a stirring tank.
The mixture was stirred for 4 hours and thoroughly mixed. Thereafter, it was cooled to room temperature to obtain immersion oil. Various performances of this immersion oil were evaluated. The results are shown in Table 1. Comparative Examples 1 and 2 PCB oil (Comparative Example 1) or silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., KF-96H) (Comparative Example 2) was used as the immersion oil, and the performance of each was evaluated. The results are shown in Table 1.

【table】

[Table] In addition, a fluorescence microscope normally uses an ultra-high pressure mercury lamp as a light source to emit ultraviolet light to excite fluorescence. The excitation light used in this case includes U excitation, V excitation, B excitation, and G excitation.
It is desirable that the amount of fluorescent light generated in each excitation beam is small. Table 2 shows the fluorescence intensity (relative intensity) in each excitation light of Examples 1 to 4 and Comparative Examples 1 and 2.

【table】

Claims (1)

[Claims] 1 A liquid diene polymer blended with at least one compound selected from a liquid olefin polymer, a liquid saturated hydrocarbon, an aliphatic saturated alcohol, and an alicyclic alcohol. Immersion oil for microscopes. 2 30 to 95 parts by weight of a liquid diene polymer and 5 to 70 parts by weight of at least one compound selected from a liquid olefin polymer, a liquid saturated hydrocarbon, an aliphatic saturated alcohol, and an alicyclic alcohol; The immersion oil according to claim 1, comprising: