JP2013024925A - Immersion oil for microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an immersion oil for microscopes that satisfies various properties required for the immersion oil for microscopes such as a refractive index, Abbe number, viscosity, and a resolution power, has low fluorescence than that of a conventional immersion oil for microscopes, and stably represents the low fluorescence without being affected by an influence of a production lot of an olefin polymer.SOLUTION: The immersion oil for microscopes includes (A) the olefin polymer subjected to hydrogenation, (B) liquid diene polymer, (C) diarylalkane, and (D) alkyl benzene.

Description

  The present invention relates to an immersion oil for a microscope. More specifically, the present invention relates to an immersion oil for microscopes that can maintain low fluorescence over a long period of time and can be stably produced, and particularly relates to an immersion oil suitable for use in a fluorescence microscope. .

Immersion oil is very commonly used in the field of microscopy. When immersion oil is used optically, not only substantially no surface aberration is obtained, but also the magnification of the microscope is increased by increasing the numerical aperture of the objective lens. Can do.
In Patent Documents 1 to 8, low-fluorescence microscope immersion oil is disclosed. These immersion oils have various properties required for microscope immersion oil such as refractive index, Abbe number, viscosity, and resolution. Although it has almost enough, the persistence of the low fluorescence is not sufficient in the measurement with a spectrophotometer or the like.
Therefore, the present applicant has previously developed an immersion oil with improved low fluorescence and durability of the low fluorescence (see Patent Document 9).

Japanese Patent No. 2623125 U.S. Pat. No. 4,465,621 JP-A-9-241214 Japanese Patent Laid-Open No. 11-160623 JP-A-11-269317 International Publication No. 2004/090602 Pamphlet JP 2004-240245 A JP 2004-240246 A International Publication No. 2008/015960 Pamphlet

When the present inventors further examined the immersion oil disclosed in Patent Document 9, when the olefin polymer to be blended was obtained industrially, the cause is unknown, but depending on the production lot, the immersion oil It has been found that there is room for further improvement from the viewpoint of stable production. In addition, improvement in image contrast is also demanded for low fluorescence immersion oil for fluorescent microscopes, and development of immersion oil with even lower fluorescence is eagerly desired.
Accordingly, an object of the present invention is to satisfy various properties required for a microscope immersion oil such as a refractive index, an Abbe number, a viscosity, and a resolving power, and has a lower fluorescence than a conventional microscope immersion oil. Then, it is providing the immersion oil for microscopes which shows the low fluorescence stably without being influenced by the production lot of an olefin polymer.

As a result of intensive investigations in view of the above situation, the present inventors have obtained an immersion oil blended with an olefin polymer subjected to a specific treatment, a liquid diene polymer, a diarylalkane and an alkylbenzene. The inventors have found that the above problems can be solved. The present invention has been completed based on such findings.
That is, the present invention relates to the following [1] to [9].
[1] A microscope immersion oil comprising (A) an olefin polymer subjected to hydrogenation treatment, (B) a liquid diene polymer, (C) a diarylalkane and (D) an alkylbenzene.
[2] The immersion oil for a microscope according to the above [1], wherein the (A) hydrogenated olefin polymer is a hydrogenated polybutene.
[3] The immersion oil for microscopes according to the above [1] or [2], wherein the number average molecular weight of the (A) hydrogenated olefin polymer is 300 to 25,000.
[4] The immersion oil for a microscope according to any one of the above [1] to [3], wherein the (B) liquid diene polymer is polyisoprene.
[5] The immersion oil for microscopes according to any one of the above [1] to [4], wherein the number average molecular weight of the (B) liquid diene polymer is 1,000 to 100,000.
[6] The microscope immersion oil according to any one of [1] to [5], wherein the (C) diarylalkane is at least one selected from phenylxylylethane and phenylethylphenylethane.
[7] The immersion oil for a microscope according to any one of the above [1] to [6], wherein the (D) alkylbenzene is 1,3,5-triisopropylbenzene.
[8] The immersion oil for microscopes according to any one of the above [1] to [7], wherein the fluorescence intensity when heated at 50 ° C. for 8 weeks is 2 times or less of the initial value.
[9] The immersion oil for microscopes according to any one of the above [1] to [8], which is for a fluorescence microscope.

  The immersion oil for microscope of the present invention stably exhibits low fluorescence without being affected by the production lot of the raw material, and further, other immersion oils necessary for the immersion oil such as refractive index, Abbe number, viscosity, and resolving power. Various characteristics are maintained at a high level. Moreover, since the storage stability is good, low fluorescence is maintained over a long period of time. Therefore, the immersion oil for microscopes of the present invention is remarkably excellent as an immersion oil for fluorescent microscopes.

[Immersion oil for fluorescent microscope]
The immersion oil for microscopes of the present invention comprises (A) an olefin polymer subjected to hydrogenation treatment, (B) a liquid diene polymer, (C) a diarylalkane and (D) an alkylbenzene.
Hereafter, each component which the immersion oil for microscopes of this invention contains is demonstrated in order.
((A) Olefin polymer subjected to hydrogenation treatment)
The number average molecular weight of (A) component used for this invention becomes like this. Preferably it is 300-25,000, More preferably, it is 500-5,000, More preferably, it is 500-3,000, and it mentions later (B)-( When dissolved in the component D), it may be in the form of a solid, but is usually preferably an olefin polymer that is liquid at normal temperature and normal pressure. The olefin polymer may be an olefin homopolymer such as polyethylene, polypropylene, polybutene, polyisobutylene, or the like obtained by using one olefin, or an olefin obtained by using two or more olefins. A copolymer may be used. In addition, an olefin type polymer may be used individually by 1 type, and may use 2 or more types together.
Among these, as the component (A), an olefin homopolymer subjected to hydrogenation treatment is preferable, and polybutene subjected to hydrogenation treatment is more preferable.
In the present specification, the number average molecular weight is a value in terms of polystyrene measured by a gel permeation chromatography (GPC) method.
In addition, the number average molecular weight of (A) component used for this invention measured the olefin before hydrogenation which is a raw material, and made it the number average molecular weight of (A) component. Even if hydrogenated, the molecular weight per molecule is theoretically increased by one hydrogen molecule (H ₂ ), and the molecular weight does not change even when hydrogenated. Therefore, in this application, the molecular weight of the raw material is measured and hydrogenated. It can be regarded as the molecular weight of the polymer.
There is no restriction | limiting in particular in the manufacturing method of the olefin polymer used as the raw material of (A) component, It can manufacture by a well-known method and all are easily available industrially. For example, as a method for producing polybutene, there may be mentioned a method in which butadiene is removed from a C4 fraction produced by naphtha decomposition and polymerization is carried out using an acid catalyst as it is.

As the component (A) to be included in the microscope immersion oil of the present invention, a olefin polymer subjected to hydrogenation treatment is used. By applying hydrogenation treatment, low fluorescence can be amplified and low fluorescence instability caused by differences in production lots of olefin polymers can be eliminated. This is because immersion oil can be obtained. The reason why such an effect is obtained is not necessarily clear, but industrially obtained olefinic polymers have impurities and other unstable factors caused by subtle differences in production conditions. It is presumed that the stability has been increased by being relaxed by the hydrogenation treatment. The effect of the present invention is manifested only when the hydrogenation treatment is applied to the olefin polymer that is the raw material of the component (A). Other components such as components (B) to (D) described later are used. In addition to the effect of hydrogenation treatment, not only the effect is obtained, but various functions as immersion oil for microscopes are deteriorated.
In addition, it is most important to perform a hydrogenation treatment on the olefin polymer, and as long as this treatment is performed, the olefin polymer is not affected greatly by the hydrogenation rate, and is stably reduced to immersion oil for microscopes. Fluorescence can be imparted. That is, even if the hydrogenation rate is about several percent, the problem of the present invention is solved as in the case of 100%. As a temporary measure, the hydrogen conversion rate is preferably 0.1% or more, more preferably 0.5% or more, and further preferably 1% or more.

There is no restriction | limiting in particular as a method of a hydrogenation process, The well-known hydrogenation process with respect to an olefin polymer can be utilized. Specifically, a method of performing a hydrogenation treatment in the presence of a hydrogenation catalyst, hydrogen, and, if necessary, a solvent can be mentioned.
Examples of the hydrogenation catalyst include nickel-based (Raney nickel, nickel-supported) catalysts, noble metal-based materials such as palladium and platinum (palladium black, palladium hydroxide, platinum oxide, palladium-supported, platinum-supported, rhenium-supported, ruthenium. (Supported) catalyst. Examples of the supported catalyst carrier include activated carbon, alumina, silica alumina, silica, diatomaceous earth, and activated clay. Among these, palladium carbon, nickel diatomaceous earth, and ruthenium carbon are preferable from the viewpoint of hydrogenation effect, that is, the effect of stably obtaining a lower fluorescence immersion oil for microscope.
Although there is no restriction | limiting in particular in the usage-amount of a hydrogenation catalyst, Preferably it is 0.1-50 mass parts with respect to 100 mass parts of olefin polymers which are going to perform a hydrogenation process, More preferably, it is 0.5-10 masses. Parts, more preferably 1 to 10 parts by mass, particularly preferably 1 to 5 parts by mass.

Although there is no restriction | limiting in particular in hydrogenation processing temperature, From a viewpoint of controlling hydrogenation reaction, Preferably it is about 0-200 degreeC normally, More preferably, it is 20-180 degreeC, More preferably, it is 50-160 degreeC, Most preferably, it is 70. ~ 140 ° C. The hydrogen pressure (the hydrogen pressure immediately before the hydrogenation treatment, hereinafter referred to as “initial hydrogen pressure”) is preferably about 0.1 to 10 MPa, more preferably 0.1 to 5 MPa, and still more preferably 0. .1-3 MPa.
Although there is no restriction | limiting in particular in hydrogenation processing time, Usually, Preferably it is about 1 minute-24 hours, More preferably, it is 5 minutes-10 hours, More preferably, it is 10-4 hours.
The solvent that can be used as needed during the hydrogenation treatment is not particularly limited as long as it is an inert solvent for the hydrogenation reaction. For example, n-pentane, n-hexane, methylpentane, n-heptane. Linear or branched aliphatic hydrocarbons having 5 to 10 carbon atoms such as methylhexane, dimethylpentane, n-octane, methylheptane, dimethylhexane, trimethylpentane, dimethylheptane, n-decane, etc .; C5-C10 alicyclic compounds such as methylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, propylcyclohexane; methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, n- Heptanol, 2-he Ethanol, n- hexanol, etc. monoalcohols such as 2-hexanol. Among these, n-hexane, n-heptane, cyclohexane, methylcyclohexane, ethylcyclohexane, and n-butanol are preferable for the convenience of the hydrogenation treatment.

((B) Liquid diene polymer)
The liquid diene polymer of the component (B) contained in the microscope immersion oil of the present invention is not particularly limited as long as it is a liquid diene polymer at room temperature and normal pressure, but preferably has a number average molecular weight. A liquid diene polymer of 1,000 to 100,000, more preferably 1,000 to 80,000, still more preferably 5,000 to 50,000, particularly preferably 15,000 to 40,000 is used.
Examples of these liquid diene polymers include a diene homopolymer composed of a diene monomer having 4 to 12 carbon atoms, a diene copolymer composed of two or more diene monomers having 4 to 12 carbon atoms, and these diene monomers and carbon numbers. Examples include copolymers with 2 to 22 α-olefin addition polymerizable monomers. Examples include butadiene homopolymer (liquid polybutadiene, hydroxyl group-containing liquid polybutadiene), isoprene homopolymer (hydroxyl group-containing liquid polyisoprene), chloroprene homopolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer, butadiene-2-hexyl acrylate copolymer, and the like. It is done.
Preferred liquid diene polymers are butadiene homopolymers such as liquid polybutadiene and hydroxyl group-containing liquid polybutadiene, isoprene homopolymers such as hydroxyl group-containing liquid polyisoprene, and copolymers composed of polybutene and polyisoprene.
The liquid diene polymer as the component (B), such as the hydroxyl group-containing liquid polybutadiene and the hydroxyl group-containing liquid polyisoprene, may have a functional group such as a hydroxyl group in the molecule and / or at the molecular end. Further, it may be a mixture of a liquid diene polymer having the functional group and a liquid diene polymer having no functional group. In addition, these liquid diene type polymers may be used individually by 1 type, and may use 2 or more types together.

((C) Diarylalkane)
The diarylalkane as the component (C) to be contained in the microscope immersion oil of the present invention is particularly limited as long as it is a diarylalkane that is liquid at normal temperature and normal pressure, or a mixed diarylalkane that is liquid at normal temperature and normal pressure. There is no. Each of the two aryl groups of the diarylalkane is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 10 carbon atoms, and 1 to 10 carbon atoms (preferably 1 to 1 carbon atoms). The alkyl group of 5) may be substituted. Further, the “alkane” portion of the diarylalkane is preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, still more preferably 1 to 5 carbon atoms, and particularly preferably carbon atoms. It is an alkane of formulas 1-3.
Examples of the diarylalkane include diphenylmethane, benzyltoluene, benzylxylene, phenyl-sec-butylphenylmethane, di-sec-butyldiphenylmethane, diphenylethane, phenyl (ethylphenyl) ethane, phenylcumylethane, diisopropylphenylethane, phenyl Examples include trilylethane, di-sec-butylphenylethane, di-tert-butylphenylethane, phenylxylylethane, phenyl-sec-butylphenylethane, diphenylpropane, diphenylbutane, ditolylethane, dixyloctane, and dixylyldecane. Among these, as the diarylalkane, it is preferable to use at least one selected from phenyl (ethylphenyl) ethane and phenylxylylethane.
As phenyl (ethylphenyl) ethane, 1-phenyl-1- (2-ethylphenyl) ethane, 1-phenyl-1- (3-ethylphenyl) ethane, 1-phenyl-1- (4-ethylphenyl) ethane 1-phenyl-2- (2-ethylphenyl) ethane and the like. Among these, as phenyl (ethylphenyl) ethane, 1-phenyl-1- (4-ethylphenyl) ethane is preferable.
Examples of phenylxylylethane include 1-phenyl-1- (2,3-dimethylphenyl) ethane, 1-phenyl-1- (2,4-dimethylphenyl) ethane, 1-phenyl-1- (2,5- Dimethylphenyl) ethane, 1-phenyl-1- (2,6-dimethylphenyl) ethane, 1-phenyl-1- (3,4-dimethylphenyl) ethane, 1-phenyl-1- (3,5-dimethylphenyl) ) Ethane, 1-phenyl-2- (2,3-dimethylphenyl) ethane and the like. Among these, as phenylxylylethane, 1-phenyl-1- (2,3-dimethylphenyl) ethane is preferable.
These diarylalkanes may be used alone or in combination of two or more as long as they are liquid at normal temperature and normal pressure.

((D) alkylbenzene)
The alkylbenzene as the component (D) to be contained in the microscope immersion oil of the present invention is not particularly limited, but the alkyl group of the alkylbenzene preferably has 1 to 4 carbon atoms, for example, methyl group, ethyl Group, isopropyl group, butyl group and the like.
Specific examples of the alkylbenzene include ethylbenzenes such as monoethylbenzene, diethylbenzene, triethylbenzene, and tetraethylbenzene; isopropylbenzenes such as monoisopropylbenzene, diisopropylbenzene, and triisopropylbenzene; monoisopropyltoluene, diisopropyltoluene, triisopropyltoluene, and the like Mention may be made of isopropyltoluenes.
Among these, 1,3,5-triisopropylbenzene, triethylbenzene, and triisopropyltoluene are preferable, and 1,3,5-triisopropylbenzene is more preferable.

In the microscope immersion oil of the present invention, the blending ratio of the components (A) to (D) can be set as appropriate, but the blending amount of the component (B) is based on 100 parts by weight of the component (A). The amount is preferably 1 to 60 parts by mass, more preferably 2 to 60 parts by mass, further preferably 10 to 50 parts by mass, and particularly preferably 10 to 40 parts by mass. Moreover, the compounding quantity of (C) component becomes like this. Preferably it is 40-100 mass parts with respect to 100 mass parts of (A) component, More preferably, it is 50-90 mass parts, More preferably, it is 60-85 mass parts. The amount of component (D) is preferably 2 to 60 parts by weight, more preferably 5 to 55 parts by weight, still more preferably 15 to 55 parts by weight, and particularly preferably 20 parts per 100 parts by weight of component (A). -50 mass parts.
When the blending ratio of the component (A), the component (B), the component (C), and the component (D) is as described above, it is easy to lower the fluorescence of the immersion oil, and the low fluorescence is maintained over a long period of time. The refractive index, Abbe number, kinematic viscosity, transparency, chromaticity, and other characteristics tend to be good. Here, other characteristics required for the immersion oil include non-dryness, appearance, weather resistance, corrosion resistance, contrast, resolution, chromatic aberration, transparency, and the like.

In preparing the immersion oil for microscope of the present invention, the order of blending the components (A), (B), (C) and (D) is not particularly limited, and various orders can be used simultaneously or stepwise. Can be blended.
Moreover, there is no restriction | limiting in particular also about the method of mix | blending each component, Usually, the method of mix | blending by stirring and mixing near normal temperature is used suitably.
The microscope immersion oil of the present invention is not limited to a microscope immersion oil such as a normal fluorescence microscope immersion oil, as long as the effect as the original immersion oil is not impaired and the effect of the present invention is not significantly reduced. Various additives used can be blended.
The immersion oil for a microscope of the present invention thus obtained can be suitably used as an immersion oil for a normal microscope, particularly an immersion oil for a fluorescence microscope.
In the present invention, a microscope that is particularly excellent in various properties required by combining each of the preferred components (A), (B), (C), and (D). An immersion oil is provided.

As preferable physical properties and characteristics of the immersion oil for microscope of the present invention obtained as described above, the refractive index (n23D) is about 1.5140 to 1.5160, and the Abbe number (ν23D) is about 38 to 44. (More preferably 39 to 43), a kinematic viscosity of about 100 to 1,000 (more preferably 300 to 1,000, still more preferably 350 to 900, particularly preferably 400 to 850), and a transparency (transmittance) of 95. % Or more.
Further, the immersion oil for a microscope of the present invention has a fluorescence intensity after heating at 50 ° C. for 8 hours, which is 2 times or less of the tendency intensity before heating, preferably 1.5 times or less, more preferably. The thing is 1.3 times or less.
In addition, all are the values measured by the method as described in an Example.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by these Examples.
In addition, each characteristic of immersion oil for microscopes was evaluated in accordance with the following method.

<Evaluation method of immersion oil for microscope>
(1) Fluorescence intensity-Low fluorescence-
The fluorescence microscope used a xenon lamp that emits ultraviolet light that excites fluorescence as a light source. The excitation light used in this case includes U excitation, B excitation, and G excitation depending on the length of the wavelength. Immersion oil that generates a small amount of fluorescence in each excitation is desirable for the fluorescence microscope. The fluorescence intensity of the immersion oil prepared in each example was measured with a spectrofluorophotometer “F-2500” manufactured by Hitachi, Ltd.
In addition, 30 g of immersion oil prepared in each example was put in a glass bottle, and the fluorescence intensity at the time of U excitation of the sample after heating at 50 ° C. for 8 weeks was measured in the same manner as described above to determine the change in fluorescence intensity with time.
It shows that it is excellent in low fluorescence, so that fluorescence intensity is small.
In the present specification, when the value of the fluorescence intensity ratio before and after heating at 50 ° C. for 8 weeks is 2.0 or less, the storage stability is good, and the value of the fluorescence intensity ratio is 2.0. If it exceeds, it indicates that the storage stability is inferior.
(2) Refractive index (n23D) and Abbe number (ν23D)
In either case, the refractive index and the Abbe number were measured according to JIS K2101 (1990). In addition, the range of a preferable refractive index as immersion liquid for microscopes is 1.5140-1.5160, and the range of the Abbe number preferable as immersion oil for microscopes is 38-44.
(3) Kinematic viscosity The kinematic viscosity at 25 ° C was measured according to JIS K2283. A preferable kinematic viscosity range for the immersion oil for a microscope is 100 to 1,000 mm ² / sec (25 ° C.).
(4) Non-drying property According to JIS C2201, “electrical insulating oil” evaporation test, the test was performed at 30 ° C. for 24 hours, and the evaluation was made in the following two stages.
Good (◯): Less than 1% by mass of evaporation Poor (×): 1% by mass

(5) Appearance Immersion oil prepared in each example was placed in a clean glass container, checked for the presence or absence of turbidity, and evaluated in the following two stages.
(◯): No turbidity (Δ): Some turbidity (6) Weather resistance Results of light irradiation test and thermal deterioration test obtained by the method described in the following (6-1) and (6-2), In addition, the evaluation was made in the following two stages according to changes in refractive index, Abbe number, and hue before and after the test.
Good (O): No change in refractive index, Abbe number, and hue.
Defect (x): There is a change in any of refractive index, Abbe number, and hue.
(6-1) Light Irradiation Test A fixed amount (40 ± 0.5 g) of immersion oil was taken in a petri dish, and the change in refractive index after irradiation with light for a certain time (120 hours) was measured.
(6-2) Heat accelerated deterioration test (storage stability test)
A fixed amount (40 ± 0.5 g) of immersion oil is put into a 50 ml conical flask with a stopper and kept in a constant temperature (70 ° C.) constant temperature bath for 24 hours, and then the refractive index, Abbe number, and hue change. Was observed.

(7) Corrosion resistance Corrosion was examined by measuring the total acid value (JIS K2501) and the effect on smear specimen dye (JIS K2400), and evaluated in the following two stages.
(○): No corrosion (×): Corrosion is present (8) Contrast In the microscope using the immersion oil prepared in each example, by looking at the black and white lines engraved on the black and white plate with chromium vapor deposition, It was evaluated in two stages.
Good (O): Clear Poor (x): Slightly unclear (9) Resolving power The refractive index measured by the method of (2) above was evaluated in the following two stages.
Good (◯): 1.5140 to 1.5160
Defect (x): outside the above range (10) Chromatic aberration Evaluation was made in the following two stages by the Abbe number measured by the method of the above item (2).
Good (◯): 38 to 44
Defect (x): Outside the above range (11) Transparency The evaluation was made in the following two stages according to the transmittance (JIS K0115).
Good (O): 95% or more Poor (x): Less than 95%

<Reference Example 1>
Each component described in Table 1 below was mixed at 25 ° C. for 10 minutes in the blending amount (unit: parts by mass) shown in Table 1 to prepare an immersion oil for a microscope. Each evaluation result of the obtained immersion oil for microscope is shown in Table 1.

* 1: Liquid olefin polymer manufactured by Idemitsu Kosan Co., Ltd. [trade name “Polybutene 100R”, number average molecular weight 960]
* 2: Liquid diene polymer manufactured by Kuraray Co., Ltd. [trade name “LIR-30”, number average molecular weight 29,000]
* 3: The case where 100R-1 was used as the component (A) was set to 10.0, and evaluation was performed based on relative values.
* 4: For other evaluation items (1), (4) to (11) [storage stability, non-drying properties, appearance, weather resistance, corrosion resistance, contrast, resolution, chromatic aberration, transparency] ○ ”.

  From Table 1, in the case of the immersion oil disclosed in Patent Document 9, blurring occurs in the fluorescence depending on the lot number of the component (A) (for example, 100R-5 to 100R-7). It can be seen that the production efficiency is not necessarily high. That is, it has been difficult to stably produce low-fluorescence immersion oil.

<Reference Example 2>
Each component described in Table 1 below was mixed at 25 ° C. for 10 minutes in the blending amount (unit: parts by mass) shown in Table 1 to prepare an immersion oil for a microscope. Each evaluation result of the obtained immersion oil for microscope is shown in Table 1.

* 1 ′: Liquid olefin polymer manufactured by Idemitsu Kosan Co., Ltd. [trade name “Polybutene 300R”, number average molecular weight 1400]
* 2: Liquid diene polymer manufactured by Kuraray Co., Ltd. [trade name “LIR-30”, number average molecular weight 29,000]
* 3: The case where 100R-1 was used as the component (A) (see Table 1) was set to 10.0, and evaluation was performed based on relative values.
* 4: For other evaluation items (1), (4) to (11) [storage stability, non-drying properties, appearance, weather resistance, corrosion resistance, contrast, resolution, chromatic aberration, transparency] ○ ”.

  According to Table 2, in the case of the immersion oil disclosed in Patent Document 9, fluorescence blurring occurs depending on the lot number of the component (A) (for example, 300R-15 to 300R-19), and the low-fluorescence immersion oil It can be seen that the production efficiency is not necessarily high. That is, it has been difficult to stably produce low-fluorescence immersion oil.

In the following examples and comparative examples, the olefin polymer subjected to the hydrogenation treatment produced in the following production examples was used. Table 3 shows the lot number of the olefin polymer used in each production example, the hydrogenation catalyst and its use amount, the initial hydrogen pressure, the treatment time, and the hydrogenation rate.
<Production Examples 1 to 12> Hydrogenation treatment of olefin-based polymer In a 100 ml autoclave made of SUS-316L equipped with a stirrer, 1.7 g of the hydrogenation catalyst listed in Table 3 and various lot numbers used in Reference Examples 15.0 g of olefin polymer and 15.0 g of hexane were charged. After the atmosphere in the autoclave was replaced with nitrogen, hydrogen gas was introduced until the hydrogen pressure shown in Table 3 was reached. Next, the temperature of the oil bath was raised to 100 ° C. while stirring.
After holding for a predetermined time, it was cooled to room temperature and the residual pressure was confirmed. The autoclave was depressurized and opened, the inner solution was taken out, and the hydrogenation catalyst was removed by filtration. The filtrate was treated with an evaporator, hexane was distilled off, and a hydrogenated olefin polymer [component (A)] was obtained.
In addition, the calculation method of the hydrogenation rate of the obtained olefin polymer is described below.
-Calculation method of hydrogenation rate-
As a result of measuring the bromine number of the products of Production Example 1 and Production Example 9 in which hydrogen absorption disappeared during the hydrogenation treatment according to JIS K 2605 “Chemical Products—Bromine Test Method—Electrotitration Method”, both were 0.1 ( g / 100 g), the hydrogenation rate of the olefin polymer obtained in Production Example 1 and Production Example 9 was set to 100%, and the olefinic polymer subjected to the hydrogenation treatment obtained in other Production Examples. The hydrogenation rate of the coalescence was calculated from the following formula from the hydrogen reduction amount in each example. The amount of decrease in hydrogen was calculated by measuring the hydrogen pressure with an autoclave pressure gauge.
(When using polybutene 100R)
Hydrogenation rate (%) = (reduction amount of hydrogen in each production example / reduction amount of hydrogen in production example 1) × 100
(When using polybutene 300R)
Hydrogenation rate (%) = (reduction amount of hydrogen in each production example / reduction amount of hydrogen in production example 9) × 100

* 5: Common to lot numbers in Tables 1 and 2.
* 6: Pd / C = Palladium carbon with 5% by mass of palladium supported N113 = Nickel / diatomaceous earth, JGC Catalysts & Chemicals Co., Ltd. Ru / C = Ruthenium carbon with 5% by mass of ruthenium supported

<Examples 1 to 12>
Each component described in Table 4 below was mixed at 25 ° C. for 10 minutes in the blending amount (unit: parts by mass) shown in Table 4 to prepare immersion oil for a microscope. Table 4 shows the evaluation results of the obtained immersion oil for microscopes.

* 2: Liquid diene polymer manufactured by Kuraray Co., Ltd. [trade name “LIR-30”, number average molecular weight 29,000]
* 3: The case where 100R-1 was used as the component (A) (see Table 1) was set to 10.0, and evaluation was performed based on relative values.
* 4: The other evaluation items (4) to (11) [non-drying property, appearance, weather resistance, corrosion resistance, contrast, resolution, chromatic aberration, transparency] were “◯” in all cases.

  From the results shown in Table 4, the immersion oil of the present invention sufficiently maintains various properties necessary as an immersion oil for microscopes, has improved low fluorescence, and is excellent in its sustainability. It can be said that it is very useful as an immersion oil for a fluorescence microscope because it can stably produce a low fluorescent substance without being affected by the lot number of the olefin polymer.

<Comparative Examples 1-3>
Each component described in Table 5 below was mixed at 25 ° C. for 10 minutes in the blending amount (unit: parts by mass) shown in Table 5 to prepare immersion oil for a microscope. Table 5 shows the evaluation results of the obtained immersion oil for microscopes.

* 2: Liquid diene polymer manufactured by Kuraray Co., Ltd. [trade name “LIR-30”, number average molecular weight 29,000]
* 3: The case where 100R-1 was used as the component (A) (see Table 1) was set to 10.0, and evaluation was performed based on relative values.

From Table 5, in the immersion oil (Comparative Example 1) containing no component (C), the refractive index decreased to less than 1.5140, and the Abbe number increased to exceed 44. Furthermore, the kinematic viscosity greatly exceeds 1,000 mm ² / sec (25 ° C.) and is too high, which is inappropriate as an immersion oil for a microscope. The immersion oil (Comparative Example 2) containing no component (B) has a kinematic viscosity of less than 100 mm ² / sec (25 ° C.) and is inappropriate as an immersion oil for a microscope. On the other hand, the immersion oil containing no component (D) (Comparative Example 3) has a kinematic viscosity exceeding 1,000 mm ² / sec (25 ° C.) and is inappropriate as an immersion oil for a microscope.

<Comparative example 4>
In Example 2, instead of the polybutene subjected to the hydrogenation treatment, the treatment was performed in the absence of the hydrogenation catalyst when the hydrogenation treatment was performed (that is, the amount of the hydrogenation catalyst used in Production Example 2). The same operation was performed except that polybutene was used, and immersion oil was prepared and evaluated. As a result, the refractive index was 1.515, the Abbe number was 41, which was the same as in Example 2, and the kinematic viscosity was 451 mm ² / sec (25 ° C.), which was within a preferable range. The relative fluorescence intensity was as extremely high as 120, the relative fluorescence intensity in B excitation was as very high as 43, and the relative fluorescence intensity in G excitation was as high as 14.0.
In addition, the said process performed in absence of a hydrogenation catalyst is not a hydrogenation process.

<Comparative Example 5>
In Example 2, instead of the polybutene subjected to the hydrogenation treatment, the treatment was performed in the absence of hydrogen when the hydrogenation treatment was performed (that is, in the production example 2, the treatment was performed with the initial hydrogen pressure set to 0 MPa). The operation was performed in the same manner except that polybutene was used, and immersion oil was prepared and evaluated. As a result, the refractive index was 1.515, the Abbe number was 41, which was the same as in Example 2, and the kinematic viscosity was 454 mm ² / sec (25 ° C.), which was within a preferable range. The relative fluorescence intensity was as extremely high as 120, the relative fluorescence intensity in B excitation was as very high as 43, and the relative fluorescence intensity in G excitation was as high as 14.0.
Note that the above process performed in the absence of hydrogen is not a hydrogenation process.

  The immersion oil for microscopes of the present invention is suitably used not only for ordinary microscopes but also for fluorescent microscopes.

Claims (9)

  An immersion oil for a microscope comprising (A) an olefin polymer subjected to a hydrogenation treatment, (B) a liquid diene polymer, (C) a diarylalkane and (D) an alkylbenzene.   The immersion oil for microscopes according to claim 1, wherein the (A) hydrogenated olefin polymer is a hydrogenated polybutene.   The immersion oil for microscopes according to claim 1 or 2, wherein the number average molecular weight of the (A) hydrogenated olefin polymer is 300 to 25,000.   The immersion oil for microscopes according to any one of claims 1 to 3, wherein the (B) liquid diene polymer is polyisoprene.   The immersion oil for microscopes in any one of Claims 1-4 whose number average molecular weights of the said (B) liquid diene polymer are 1,000-100,000.   The immersion oil for microscopes according to any one of claims 1 to 5, wherein the (C) diarylalkane is at least one selected from phenylxylylethane and phenylethylphenylethane.   The immersion oil for microscopes according to any one of claims 1 to 6, wherein the (D) alkylbenzene is 1,3,5-triisopropylbenzene.   The immersion oil for microscopes according to any one of claims 1 to 7, wherein the fluorescence intensity when heated at 50 ° C for 8 weeks is not more than twice the initial value.   The immersion oil for microscopes according to any one of claims 1 to 8, which is used for a fluorescence microscope.