JP3326251B2 - Polymer film for chemical substance detection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polymer film useful for detecting and distinguishing the presence of a gaseous or liquid chemical. More specifically, the present invention relates to a polymer film that can detect gasoline vapor and diesel oil vapor separately.

[0002]

2. Description of the Related Art In a gas station or the like, when refueling an automobile, an accident often occurs in which a wrong type of fuel is supplied. To prevent such accidents, there is a strong demand to develop a fuel detection system.

[0003] As a detector for hydrocarbons including automobile fuel, there is a detector utilizing an electric or optical detection method. In the case of using the electrical detection method, the target substance is adsorbed on the semiconductor substance,
Some of them utilize the fact that the resistance value or conductance value of the substance changes. For example, Japanese Unexamined Patent Publication No. 50-74485
Japanese Patent Application Laid-Open Publication No. H11-139,086 discloses a gas detector in which a counter electrode is provided on an insulating substrate, and a silicon rubber resistor containing conductive particles is applied between the two electrodes. A detector similar to this is disclosed in
-96846 and JP-A-3-96847, and German Patent Application No. 2419069 (1975).
(November 6, 2008).

Brown et al. Disclose a method of detecting a change in ionic conductivity due to adsorption of gas by polarography using a solid electrolyte (ion exchange membrane) (Proceedings of the Jo).
int Conference sensing
of Environmental pollutan
ts, AIAA Paper 71-1114 (19
71) 1-3). A similar method is described in UK Patent Application Publication No. 2
It is also disclosed in 185579. In these methods, temperature control for detection is indispensable, and complicated equipment is required for monitoring the temperature.

Japanese Patent Application Laid-Open No. 63-285439 discloses a sensor for detecting leakage of hydrocarbons by changing the impedance of a coaxial cable. Since these detectors detect hydrocarbons electrically, there are inherent problems such as malfunction due to disturbances such as induction noise, and the danger of explosion of hydrocarbons due to ignition by sparks or the like.

On the other hand, as a method using an optical detection method, for example, in Japanese Patent Application Laid-Open No. 55-156838,
There is disclosed a method of detecting the presence of oil or the like by a change in refractive index due to absorption of oil or the like by a porous body. A similar method using optical fibers utilizing capillary action is also described in EP-A-0 282 2009. Japanese Patent Application Laid-Open No. 60-238746 discloses a device for detecting the concentration of a hydrocarbon gas from a change in infrared absorbance by providing an infrared detector on the side of a duct through which the hydrocarbon gas flows. In addition, Japanese Unexamined Patent Publication
No.-47531 discloses a sensor that utilizes the fact that the propagation mode of an optical fiber is converted into a leaky mode by the attachment of oil or water to the surface of the optical fiber.

Although the above-mentioned various detectors can detect the presence or absence of hydrocarbons, it is difficult to separately detect a plurality of types of hydrocarbons. In particular, it is very difficult to detect gasoline and diesel oil, which have very similar properties, separately. Furthermore, hydrocarbons have a risk of ignition, but the above-mentioned detectors are not sufficiently safe. In addition, the above-mentioned detector requires a large-scale device and is expensive.

[0008]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a detector capable of detecting a plurality of types of chemical substances safely and individually.

Another object of the present invention is to provide a detector capable of safely and separately detecting gasoline and diesel oil.

[0010]

Means for Solving the Problems In order to solve the above problems,
ADVANTAGE OF THE INVENTION According to this invention, the chemical substance detection film containing the vinyl polymer which has a specific side chain group is provided. That is,
According to the present invention, there is provided a chemical substance detecting film comprising a homopolymer or a copolymer having the following repeating unit (I).

[0011]

Embedded image

(Wherein X represents —CH ₃ , and R ¹ represents —
(C = O) represents -O-R ^2, R ² may be the same or different straight-chain alkyl group, branched alkyl group, a cycloalkyl group,
Represents an unsaturated hydrocarbon group, an aryl group, a saturated or unsaturated heterocycle, or a substituted product thereof. The present inventors have conducted intensive studies to find a chemical substance detection film capable of detecting a plurality of chemical substances, particularly organic solvents, and found that a specific side chain group in a vinyl polymer has a molecular recognition function. And completed the present invention.
By utilizing such a molecular recognition function of a specific side chain group, heterogeneous chemical substances such as cycloalkanes and benzenes and linear alkanes can be distinguished from each other.
Similarly, hydrocarbons, alcohols, ketones,
Esters, ethers and halogenated hydrocarbons can be distinguished.

The interaction between the chemical substance and the side groups of the vinyl polymer is manifested in the form of swelling of the polymer. That is, the presence or absence of a chemical substance can be detected by the swelling of the polymer, and the type of the chemical substance can be specified by the degree of swelling of the polymer. For example, aromatic hydrocarbons and cycloalkanes interact more with vinyl polymers having aromatic groups and branched or cycloalkyl groups as side groups than vinyl polymers having linear alkyl groups as side groups. Is big. Therefore, the degree of swelling of the polymer will be different. As a result, in the present invention, it is particularly possible to detect gasoline and diesel oil separately. According to the present invention, it could be used sufficiently in the temperature range of -40 to 80 ° C. normally required for detecting gasoline and diesel oil. For a more detailed distinction between chemical substances, it is advantageous to use films formed from two or more polymers having different side groups.

The chemical substance detecting film of the present invention comprises the polymer having the above-mentioned repeating unit (I). That is, it may be a homopolymer consisting of only a single repeating unit (I), or a copolymer consisting of another repeating unit and the above repeating unit (I) or a copolymer consisting of two or more kinds of the above repeating unit (I) It may be. When the chemical substance detecting film of the present invention is formed from a copolymer, the arrangement of the repeating units in the copolymer may be any. For example, the chemical substance detection film of the present invention can be formed from a random copolymer, an alternating copolymer, a block copolymer, or a graft copolymer.

Preferred polymers used in the present invention are polymethacrylates, polyacrylates and the like. The side chain group of the ester is preferably a straight-chain or branched alkyl group or a cycloalkyl group, and preferably has 4 to 22 carbon atoms.

Preferred polymers in the present invention include, for example, the following. Poly (2-ethylhexyl methacrylate-co-methyl methacrylate) Poly (methyl methacrylate-co-2-ethylhexyl acrylate) Poly (methyl methacrylate-co-2-ethylhexyl methacrylate) Poly (isobutyl methacrylate-co- Poly (glycidyl methacrylate) Poly (dodecyl methacrylate-co-glycidyl methacrylate) Poly (butyl methacrylate-co-methyl methacrylate) Poly (butyl methacrylate-co-glycidyl methacrylate) Poly (2-ethylhexyl methacrylate-co- Glycidyl methacrylate) poly (cyclohexyl methacrylate-co-glycidyl methacrylate) poly (cyclohexyl methacrylate-co-methyl methacrylate) poly (benzyl methacrylate-co-meth-methacrylic acid 2-)
Ethylhexyl) Poly (2-ethylhexyl methacrylate-co-benzyl-methacrylate-co-glycidyl methacrylate) Poly (2-ethylhexyl methacrylate-co-methyl methacrylate-co-glycidyl methacrylate) Poly (cyclohexyl methacrylate-co- Poly (cyclohexyl methacrylate-co-2-ethylhexyl methacrylate) Poly (butyl methacrylate-co-2-ethylhexyl methacrylate) Poly (butyl methacrylate-co-isobutyl methacrylate) Poly (cyclohexyl methacrylate-) co-butyl methacrylate poly (cyclohexyl methacrylate-co-dodecyl methacrylate) poly (butyl methacrylate-co-ethyl methacrylate) poly (butyl methacrylate) -Co-octadecyl methacrylate) poly (4-methylstyrene) poly (cyclohexyl methacrylate-co-benzyl methacrylate) poly (dodecyl methacrylate-co-benzyl methacrylate) poly (octadecyl methacrylate-co-benzyl methacrylate) Poly (benzyl methacrylate-co-tetrahydrofurfuryl methacrylate) poly (benzyl methacrylate-co-hexadecyl methacrylate) poly (dodecyl methacrylate-co-methyl methacrylate) poly (dodecyl methacrylate-co-ethyl methacrylate) Poly (2-ethylhexyl methacrylate-co-dodecyl methacrylate) Poly (2-ethylhexyl methacrylate-co-octadecyl methacrylate) Poly (2-ethylbutyl methacrylate-co-meth) Benzyl acrylate) poly (tetrahydrofurfuryl methacrylate-co-glycidyl methacrylate) poly (2-ethylbutyl methacrylate-co-glycidyl methacrylate) poly (2-ethylhexyl methacrylate-co-propyl methacrylate) poly (methacrylic acid) Octadecyl-co-isopropyl methacrylate) In the present invention, by forming a copolymer using a specific combination of monomers and adjusting the composition thereof, effects such as an increase in selectivity to certain chemical substances can be obtained.

The polymer for forming the chemical substance detection film of the present invention can be crosslinked by itself, or can be crosslinked by introducing a compound having a reactive group for crosslinking into the polymer. It is possible to Such reactive groups for crosslinking include, for example, amino groups, hydroxyl groups, carboxyl groups, epoxy groups, carbonyl groups and urethane groups and their derivative groups. Other examples include, for example, a C = C double bond. Compounds having such a double bond include, for example, maleic acid,
There are fumaric, sorbic, itaconic and cinnamic acids and their derivatives. Substances having a chemical structure capable of forming carbene or nitrene upon irradiation with visible light, ultraviolet light or high-energy radiation can also be used as a crosslinking agent. The advantage of cross-linking the polymer is that the film formed from the cross-linked polymer is insoluble and increases stability. The crosslinking method is not particularly limited, and a conventionally known crosslinking method, for example, a method by heating or a method by irradiation with light or radiation can be used.

When a film is formed from the above-mentioned polymer, any known film forming method can be used. For example, spin coating, casting of a polymer solution, and melt extrusion can be used. Since the thickness of the film is preferably as small as possible in order to enhance the detection sensitivity, it is preferable to use a film forming method capable of reducing the thickness of the film, particularly a spin coating method.

In the chemical substance detecting film of the present invention, when it is desired to shorten the response time, it is desirable that the glass transition temperature of the film forming polymer is lower than the temperature of the detecting environment.

Further, according to the present invention, there is provided a chemical substance detector having a chemical substance detecting film comprising the above-mentioned polymer. As described above, since the chemical substance detection film of the present invention swells by interacting with the chemical substance, it is possible to detect the chemical substance using this swelling. That is, a chemical substance can be detected from a physical change accompanying the swelling of the film, for example, a change in weight, a change in film thickness, or a change in refractive index. Therefore,
The chemical substance detector of the present invention comprises a chemical substance detecting film, and further comprises a detecting means for detecting a physical change of the chemical substance detecting film. As the detection means,
Optical means are preferred.

As the optical means, for example, an interference amplification reflection method, a surface plasmon resonance method, a Mach-Zehnder interferometer having a different top coating, a change due to swelling of a propagation mode in a waveguide, and the like can be used. In the chemical substance detector of the present invention, it is particularly preferable to use an interference amplification reflection method measuring means as the detecting means, because the sensitivity is further increased.

Of course, it is also possible to use a detecting means other than the optical means. For example, an electric detecting means, a detecting means using a quartz oscillator, or the like can be used. Interference amplification reflection method (Interference Enhancement method)
d Reflection (IER method) is a method utilizing the reflection characteristics of a polymer film on a highly reflective substrate. Light reflected on the surface of the polymer film and light reflected on the interface between the polymer film and the substrate interfere with each other. The intensity of the reflected light largely depends on the thickness and the refractive index of the polymer film. That is, a change in the thickness or the refractive index of the polymer film, or a change in both, appears as a change in the intensity of the reflected light. Furthermore, even when the swelling behavior in a plurality of polymer films is different,
The swelling of each polymer film can be easily determined from each change in the intensity of the reflected light. That is, IER
According to the law, the physical change of chemical substance detection film
Changes in film thickness and refractive index are used.

Surface plasmon resonance method (Surface)
In the Plasmon Resonance (SPR method), light at which the momentum and energy of photons at the metal-dielectric interface match those of the surface plasmon is incident at a critical angle, thereby optically forming the metal-dielectric interface. It can be excited. As a result, the photon energy couples with the surface plasmon, and a sharp decrease in the intensity of the reflected light is observed. Such surface plasmon coupling is greatly affected by the thickness of the metal film and the properties of the dielectric on one side of the metal film. That is, in the SPR method, changes in film thickness and refractive index are used as physical changes of the chemical substance detection film.

The film for detecting a chemical substance of the present invention is preferably used together with a substrate supporting the film. The type of such a substrate differs depending on the type of detecting means for detecting a physical change of the film. For example, when using the IER method, a silicon wafer,
Glass, polymers, metals and the like can be used.
On the other hand, when the SPR method is used, a metal thin film, preferably a silver thin film or a gold thin film applied on glass or a transparent polymer can be used.

[0025]

Example 1 Poly (2-ethylhexyl methacrylate)
Preparation of 19.83 grams (0.1 mole) of 2-ethylhexyl methacrylate and 164 milligrams of azobisisobutyronitrile (AIBN) were dissolved in 100 milliliters of tetrahydrofuran at 20 ° C.
The solution was purged with nitrogen for 1 hour. The solution was then heated to reflux at 65 ° C. for 7 hours. During reflux, the solution was purged with nitrogen to keep oxygen out. 20 solution
C. and subsequently poured into 1 liter of methanol, whereupon poly (2-ethylhexyl methacrylate) precipitated. In order to further increase the purity of the poly (2-ethylhexyl methacrylate), the poly (2-ethylhexyl methacrylate) was dissolved in 50 ml of tetrahydrofuran and subsequently precipitated with 1 liter of methanol. Finally, the viscous poly (2-ethylhexyl methacrylate) was collected and dried at 60 ° C. in vacuo. After drying, a test was performed by thin-layer chromatography to detect monomers remaining in the obtained poly (2-ethylhexyl methacrylate). However, in the poly (2-ethylhexyl methacrylate), no residual monomer was found. It was not included at all.

Finally, a colorless and transparent poly (methacrylic acid 2)
-Ethylhexyl) was obtained. The refractive index of this poly (2-ethylhexyl methacrylate) was measured using an Abbe refractometer.
482.

Elemental analysis of this poly (2-ethylhexyl methacrylate) gave the following results. Incidentally, poly (2-ethylhexyl methacrylate) is represented by C ₁₂ H ₂₂ O _2, was calculated molecular weight as 198.31.

[0028] In addition, gel permeation chromatography of this poly (2-ethylhexyl methacrylate) was measured.
Calibration was performed using tetrahydrofuran as a solvent and polystyrene as a standard. As a result, the weight average molecular weight Mw of this poly (2-ethylhexyl methacrylate) was 63,100, and the number average molecular weight Mn was 30,400. In addition, the molecular weight distribution Mw /
Mn was 2.08.

[0029]

Example 2 Poly (2-ethylhexyl methacrylate )
Preparation of 18.428 grams (0.1 mole) of 2-ethylhexyl acrylate, 20.024 grams (0.2 mole) of methyl methacrylate, and 164 milligrams of AIBN in 100 milliliters It was dissolved in tetrahydrofuran at 20 ° C. The solution was purged with nitrogen for 1 hour. The solution was then heated to reflux at 65 ° C. for 7 hours.
During reflux, the solution was purged with nitrogen to keep oxygen out. The solution was cooled to 20 ° C.,
Upon pouring into 00 ml of methanol, poly (2-ethylhexyl methacrylate-co-methyl methacrylate) precipitated. In order to further increase the purity of the poly (2-ethylhexyl methacrylate-co-methyl methacrylate), the poly (2-ethylhexyl methacrylate-co-methyl methacrylate) is dissolved in 100 ml of tetrahydrofuran, followed by 800 ml Of methanol. Finally, the resulting poly (2-ethylhexyl methacrylate-co-methyl methacrylate) was collected and dried at 60 ° C. in vacuo. After drying, a thin layer chromatography test was carried out to detect monomers remaining in the obtained poly (2-ethylhexyl methacrylate-co-methyl methacrylate). (co-methyl methacrylate) contained no residual monomer.

Finally, a colorless and transparent poly (methacrylic acid 2)
-Ethylhexyl-co-methyl methacrylate) is 1
5.3 grams were obtained. The refractive index of this poly (2-ethylhexyl methacrylate-co-methyl methacrylate) measured using an Abbe refractometer was 1.457 at 24 ° C.

The poly (methacrylic acid 2-methacrylate) was measured with a differential scanning calorimeter (DSC7 manufactured by Perkin-Elmer Co.).
The glass transition temperature of ethylhexyl-co-methyl methacrylate) was measured and found to be 22 ° C (heating rate 10 ° C / min).

Elemental analysis of the poly (2-ethylhexyl methacrylate-co-methyl methacrylate) revealed that the content of carbon was 64.65% and that of hydrogen was 9.41%. From these results, the ratio of the two comonomers in poly (2-ethylhexyl methacrylate-co-methyl methacrylate) was that 2-ethylhexyl methacrylate was 0.29 and methyl methacrylate was 0.71. I understood.

Further, the gel permeation chromatography of this poly (2-ethylhexyl methacrylate-co-methyl methacrylate) was measured. Calibration was performed using tetrahydrofuran as a solvent and polystyrene as a standard. As a result, the weight average molecular weight Mw of this poly (2-ethylhexyl methacrylate-co-methyl methacrylate) was 57,800, and the number average molecular weight Mn was 32,500. Also,
The molecular weight distribution Mw / Mn was 1.8.

[0034]

REFERENCE EXAMPLE 3 Preparation of polydecyl dodecyl methacrylate 50.882 g (0.2 mol) of dodecyl methacrylate and 164 mg of AIBN were dissolved in 100 ml of tetrahydrofuran at 20 ° C. The solution was purged with nitrogen for 1 hour. The solution was then heated to reflux at 65 ° C. for 7 hours. During reflux, the solution was purged with nitrogen to keep oxygen out. The solution was cooled to 20 ° C. and subsequently poured into 800 ml of methanol to give poly (dodecyl methacrylate).
Precipitated. In order to further increase the purity of the poly (dodecyl methacrylate), the poly (dodecyl methacrylate) was dissolved in 100 ml of tetrahydrofuran and subsequently precipitated with 800 ml of methanol. Finally, the viscous poly (dodecyl methacrylate) was collected and dried at 60 ° C. in vacuo. After drying,
In order to detect residual monomers in the obtained poly (dodecyl methacrylate), a test by thin layer chromatography was carried out, but no residual monomers were contained in the poly (dodecyl methacrylate).

Finally, 23.6 g of colorless and transparent poly (dodecyl methacrylate) was obtained. When the refractive index of this poly (dodecyl methacrylate) was measured using an Abbe refractometer, it was 1.474 at 24 ° C.

Elemental analysis of this poly (dodecyl methacrylate) gave the following results. Incidentally, poly (dodecyl methacrylate) is represented by C ₁₆ H ₃₀ O ₂ ,
The molecular weight was calculated as 254.41.

[0037] In addition, gel permeation chromatography of this poly (dodecyl methacrylate) was measured. Calibration was performed using tetrahydrofuran as a solvent and polystyrene as a standard. As a result, the weight average molecular weight Mw of this poly (dodecyl methacrylate) was 1
The number average molecular weight Mn is 49,000.
Met. The molecular weight distribution Mw / Mn was 2.3.

[0038]

Reference Example 4 Poly (2-ethylhexyl methacrylate )
Preparation of 19.83 g (0.1 mol) of 2-ethylhexyl methacrylate, 10.4 g (0.1 mol) of styrene and 164 mg of AIBN in 120 ml of tetrahydrofuran at 20 DEG C. It was dissolved. The solution was purged with nitrogen for 1 hour. The solution was then heated to reflux at 65 ° C. for 7 hours. During reflux, the solution was purged with nitrogen to keep oxygen out. The solution was cooled to 20 ° C. and subsequently poured into 800 ml of hexane, whereupon poly (2-ethylhexyl methacrylate-co-styrene) precipitated. To further increase the purity of the poly (2-ethylhexyl methacrylate-co-styrene), the poly (2-ethylhexyl methacrylate-co-styrene) was dissolved in 50 ml of tetrahydrofuran and subsequently precipitated with 800 ml of hexane. I was sorry. Finally, the resulting poly (2-ethylhexyl methacrylate-co-styrene) was collected and dried at 60 ° C. in vacuo. After drying,
The resulting poly (2-ethylhexyl methacrylate-co)
-Styrene) to detect residual monomers in
A test by thin layer chromatography revealed that the poly (2-ethylhexyl methacrylate-co-styrene)
No residual monomer was contained therein.

Finally, a colorless and transparent poly (methacrylic acid 2)
-Ethylhexyl-co-styrene) was obtained. When the refractive index of this poly (2-ethylhexyl methacrylate-co-styrene) was measured using an Abbe refractometer, it was 1.522 at 23 ° C.

Further, this poly (methacrylic acid 2-methacrylate) was measured with a differential scanning calorimeter (DSC7 manufactured by Perkin-Elmer Co.).
The glass transition temperature of ethylhexyl-co-styrene) was measured and found to be 13 ° C (heating rate 10 ° C /
Minutes).

Elemental analysis of the poly (2-ethylhexyl methacrylate-co-styrene) revealed that the content of carbon was 79.58% and the content of hydrogen was 9.96%. From these results, it was found that poly (2-ethylhexyl methacrylate-
The ratio of the two comonomers in (co-styrene) was found to be 0.49 for 2-ethylhexyl methacrylate and 0.51 for styrene.

In addition, gel permeation chromatography of the poly (2-ethylhexyl methacrylate-co-styrene) was measured. Calibration was performed using tetrahydrofuran as a solvent and polystyrene as a standard. As a result, the poly (2-ethylhexyl methacrylate-co-styrene) had a weight average molecular weight Mw of 50,300 and a number average molecular weight Mn of 29,300. Further, the molecular weight distribution Mw / Mn was 1.73.

[0043]

Example 5 Poly (isobutyl methacrylate-co-meth )
Preparation of 30.0 grams (0.21 mole) of isobutyl methacrylate, 1.58 grams (0.00222 mole) of glycidyl methacrylate and 164 milligrams of AIBN
It was dissolved at 20 ° C. in 00 ml of tetrahydrofuran. The solution was purged with nitrogen for 1 hour.
The solution was then heated to reflux at 65 ° C. for 7 hours. During reflux, the solution was purged with nitrogen to keep oxygen out. The solution was cooled to 20 ° C and the solution was subsequently
Poly (isobutyl methacrylate-co-glycidyl methacrylate) precipitated when poured into milliliters of hexane. In order to further increase the purity of the poly (isobutyl methacrylate-co-glycidyl methacrylate), the poly (isobutyl methacrylate-co-glycidyl methacrylate) is dissolved in 50 ml of tetrahydrofuran and subsequently precipitated with 800 ml of methanol. I was sorry. Finally, the resulting poly (isobutyl methacrylate-co-glycidyl methacrylate) is collected,
Dry at 60 ° C. in vacuum. After drying, a thin layer chromatography test was carried out to detect monomers remaining in the obtained poly (isobutyl methacrylate-co-glycidyl methacrylate). Glycidyl)
No residual monomer was contained therein.

Finally, 16 g of colorless and transparent poly (isobutyl methacrylate-co-glycidyl methacrylate) was obtained. The poly (isobutyl methacrylate-co
-Glycidyl methacrylate) was found to be 1.475 at 22 ° C. using an Abbe refractometer.

The glass transition temperature of this poly (isobutyl methacrylate-co-glycidyl methacrylate) was measured using a differential scanning calorimeter (DSC7, manufactured by Perkin-Elmer Co., Ltd.). Temperature rate 10 ° C / min).

The poly (isobutyl methacrylate-co
Elemental analysis of -glycidyl methacrylate) revealed that carbon was 66.97% and hydrogen was 9.92%. From this result, poly (isobutyl methacrylate-
The molar fraction of the two comonomers in (co-glycidyl methacrylate) was found to be 0.93 for isobutyl methacrylate and 0.07 for glycidyl methacrylate.

In addition, gel permeation chromatography of this poly (isobutyl methacrylate-co-glycidyl methacrylate) was measured. Calibration was performed using tetrahydrofuran as a solvent and polystyrene as a standard. As a result, the poly (isobutyl methacrylate-co-glycidyl methacrylate) had a weight average molecular weight Mw of 61,000 and a number average molecular weight Mn of 40,500. Further, the molecular weight distribution Mw / Mn was 1.55.

[0048]

Example 6 Detection of hydrocarbon vapor by interference amplification reflection method Gasoline and diesel oil vapor and other hydrocarbons were detected at room temperature by interference amplification reflection method (IER method) using the polymer film for detecting a chemical substance of the present invention. Optically detected.

Table 1 shows the polymers used in the IER method. The polymer is dissolved in cyclohexanone to a concentration of 5
A 10% by weight solution was made and then spin coated on a silicon substrate. After spin coating, the film was baked under vacuum near its glass transition temperature for about 1.5 hours. The thickness of the film thus obtained was measured with a 3030ST surface texture analysis system manufactured by DEKTAK. For best detection sensitivity, the thickness of the polymer film should be less than 1 μm, typically around 130 nm.

During the measurement by the IER method, the silicon substrate having the polymer film was sealed in a flow-through cell.
Gasoline and diesel oil vapors and other chemicals can be introduced into the flow-through cell along with air or nitrogen. The vapors were obtained by bubbling air or nitrogen into liquid gasoline or the like. The chemicals used in this example were hexane and toluene.

The polymer film was irradiated with He-Ne laser light at an incident angle of 70 °. This laser light was linearly polarized in a direction perpendicular to the plane of incidence. The intensity of the reflected light was monitored with a light detector. The output of the photodetector is output to a chart recorder and personal computer (Comp
aq 386 PC).

Table 1 shows the measurement results. The sensitivity in Table 1 is expressed as a percentage obtained by dividing the change in the intensity of the reflected light by the absolute value of the intensity of the reflected light. As is clear from Table 1, the measurement sensitivity varied depending on the type of hydrocarbon.
In particular, it should be noted that the difference in sensitivity between gasoline and diesel oil is very large.

[0053]

[Table 1]

CoP (MMA-EHMA) in the above table
Is an embodiment of the present invention. Others are reference examples.
The symbols in the table represent the following polymers.

PMMA: poly (methyl methacrylate) PiDMA: poly (isodecyl methacrylate) CoP (EHMA-St): poly (2-ethylhexyl methacrylate-co-styrene) (2-ethylhexyl methacrylate: styrene = 0.4)
9: 0.51) PEHMA: Poly (ethylhexyl methacrylate) CoP (MMA-EHA): Poly (methyl methacrylate-co-2-ethylhexyl acrylate) (Methyl methacrylate: 2-ethylhexyl acrylate = 0.71) 0.29) CoP (MMA-EHMA):
Poly (methyl methacrylate-co-2-ethylhexyl methacrylate) (Methyl methacrylate: 2-ethylhexyl methacrylate = 0.62: 0.38) PCHA: Poly (cyclohexyl acrylate) PDDMA: Poly (dodecyl methacrylate) PVP ： Poly (vinyl propionate)

[0056]

Comparative Example Instead of the thin film used in Example 6, poly (ethylene adipate), poly (ethylene terephthalate),
Using a thin film of poly (1,4-butylene terephthalate), poly (ethylene succinate), poly (ε-caprolactam), nylon 66, cellulose, and polyacrylonitrile, hydrocarbon vapor was obtained in the same procedure as in Example 6. However, sufficient sensitivity was not obtained.

[0057]

[Reference Example 7] Poly (tetrahydrofurfuryl methacrylate )
Preparation of 17.021 grams (0.1 mole) of tetrahydrofurfuryl methacrylate and 164 milligrams of AIBN were dissolved in 100 milliliters of tetrahydrofuran at 20 ° C. The solution was purged with nitrogen for 1 hour. The solution was then heated to reflux at 65 ° C. for 4 hours.
During reflux, the solution was purged with nitrogen to keep oxygen out. The solution was cooled to 20 ° C.,
Upon pouring into 00 ml of methanol, poly (tetrahydrofurfuryl methacrylate) precipitated. In order to further increase the purity of the poly (tetrahydrofurfuryl methacrylate), the poly (tetrahydrofurfuryl methacrylate) was dissolved in 100 ml of tetrahydrofuran and subsequently precipitated with 1.0 liter of methanol. Finally, the poly (tetrahydrofurfuryl methacrylate) was collected and dried at 60 ° C. in vacuum.
After drying, the resulting poly (tetrahydrofurfuryl methacrylate) was tested by thin-layer chromatography to detect residual monomers. In this poly (tetrahydrofurfuryl methacrylate), no residual monomer was found. It was not included at all.

Finally, 12.53 g of colorless and transparent poly (tetrahydrofurfuryl methacrylate) was obtained.
5 of this poly (tetrahydrofurfuryl methacrylate)
A weight-% THF solution is prepared and spin-coated on a silicon substrate to form a thin film, and the refractive index is determined by a three-wavelength automatic ellipsometer Auto EL IV NIRIII manufactured by Rudol Research.
Was 1.503 at 23 ° C.

The glass transition temperature of this poly (tetrahydrofurfuryl methacrylate) was measured with a differential scanning calorimeter (DSC7, manufactured by PerkinElmer) (heating rate: 20 ° C./min) and found to be 49 ° C. .

The poly (tetrahydrofurfuryl methacrylate) was measured for gel permeation chromatography. Calibration was performed using tetrahydrofuran as a solvent and polystyrene as a standard. As a result, the weight average molecular weight Mw of this poly (tetrahydrofurfuryl methacrylate) was 95,800.
And the number average molecular weight Mn was 45,200. Further, the molecular weight distribution Mw / Mn was 2.12.

[0061]

Example 8 Poly (2-ethylhexyl methacrylate )
Preparation of co-glycidyl methacrylate) 19.83 grams (0.1 mole) of 2-ethylhexyl methacrylate, 14.22 grams (0.1 mole) of glycidyl methacrylate and 164 milligrams of AIBN in 120 milliliters of tetrahydrofuran At 20 ° C. The solution was purged with nitrogen for 1 hour. The solution was then heated to reflux at 65 ° C. for 7 hours.
During reflux, the solution was purged with nitrogen to keep oxygen out. The solution was cooled to 20 ° C. and subsequently poured into 1.2 liters of methanol, whereupon poly (2-ethylhexyl methacrylate-co-glycidyl methacrylate) precipitated. To further increase the purity of the poly (2-ethylhexyl methacrylate-co-glycidyl methacrylate), the poly (2-ethylhexyl methacrylate-co-glycidyl methacrylate) was dissolved in 100 ml of tetrahydrofuran. It was precipitated with 5 liters of methanol. Finally,
The resulting poly (2-ethylhexyl methacrylate-co)
-Glycidyl methacrylate) was collected and dried at 60 ° C in vacuum. After drying, the resulting poly (methacrylic acid 2
-Ethylhexyl-co-glycidyl methacrylate) was tested by thin layer chromatography to detect monomers remaining in the poly (2-ethylhexyl methacrylate-co-glycidyl methacrylate).
No residual monomer was contained therein.

Finally, a colorless and transparent poly (methacrylic acid 2)
-Ethylhexyl-co-glycidyl methacrylate) was obtained. This poly (methacrylic acid 2-
Ethylhexyl-co-glycidyl methacrylate)
A 0 wt% cyclohexanone solution is prepared and spin-coated on a silicon substrate to form a thin film, and the refractive index of the three-wavelength automatic ellipsometer Auto EL IV manufactured by Rudol Research Co., Ltd.
As determined by NIR III, at 23 ° C.
498.

Further, this poly (methacrylic acid 2-methacrylate) was measured with a differential scanning calorimeter (DSC7 manufactured by Perkin-Elmer Co., Ltd.).
The glass transition temperature of ethylhexyl-co-glycidyl methacrylate) was measured and found to be 29 ° C (heating rate 10 ° C / min).

Elemental analysis of this poly (2-ethylhexyl methacrylate-co-glycidyl methacrylate) revealed that the content of carbon was 66.53% and that of hydrogen was 9.54.
%Met. From these results, the ratio of the two comonomers in poly (2-ethylhexyl methacrylate-co-glycidyl methacrylate) was 0.5 for 2-ethylhexyl methacrylate and 0.5 for glycidyl methacrylate.
It turned out to be.

Further, the gel permeation chromatography of this poly (2-ethylhexyl methacrylate-co-glycidyl methacrylate) was measured. Calibration was performed using tetrahydrofuran as a solvent and polystyrene as a standard. As a result, the weight average molecular weight Mw of this poly (2-ethylhexyl methacrylate-co-glycidyl methacrylate) was 95,000.
And the number average molecular weight Mn was 42,000.
Further, the molecular weight distribution Mw / Mn was 2.26.

[0066]

Example 9 Poly (benzyl methacrylate-co-meth)
Preparation of 2-ethylhexyl acrylate ) 24.67 g (0.14 mol) of benzyl methacrylate, 13.88 g (0.07 mol) of 2-ethylhexyl methacrylate and 164 mg of AIBN were added to 100 ml of tetrahydrofuran. At 20 ° C. The solution was purged with nitrogen for 1 hour. The solution was then heated to reflux at 65 ° C. for 6 hours.
During reflux, the solution was purged with nitrogen to keep oxygen out. The solution was cooled to 20 ° C. and then
Upon pouring into 1 liter of methanol, poly (benzyl methacrylate-co-2-ethylhexyl methacrylate) precipitated. In order to further increase the purity of the poly (benzyl methacrylate-co-2-ethylhexyl methacrylate), the poly (benzyl methacrylate-co-2-ethylhexyl methacrylate) is dissolved in 50 ml of tetrahydrofuran, and then dissolved in 1 liter. Of methanol. Finally, the resulting poly (benzyl methacrylate-co-2-ethylhexyl methacrylate) was collected and dried at 60 ° C. in vacuo. After drying,
In order to detect monomers remaining in the obtained poly (benzyl methacrylate-co-2-ethylhexyl methacrylate), a test by thin-layer chromatography was performed, and the poly (benzyl methacrylate-co-meth-acrylic acid 2) was tested. -Ethylhexyl) contained no residual monomer.

Finally, colorless and transparent poly (benzyl methacrylate-co-2-ethylhexyl methacrylate)
4.5 grams were obtained. A 10% by weight cyclohexanone solution of this poly (benzyl methacrylate-co-2-ethylhexyl methacrylate) was prepared and spin-coated on a silicon substrate to form a thin film, and the refractive index was measured by a three-wavelength automatic ellipsometer Auto EL IV manufactured by Rudol Research Co., Ltd. N
1.53 at 23 ° C as measured by IR III.
It was 4.

The glass transition temperature of this poly (benzyl methacrylate-co-2-ethylhexyl methacrylate) was measured with a differential scanning calorimeter (DSC7, manufactured by Perkin-Elmer Co.), and was 36.0 ° C. (Heating rate 10 ° C./min).

This poly (benzyl methacrylate-co-
Elemental analysis of 2-ethylhexyl methacrylate) revealed that carbon was 74.56% and hydrogen was 8.62%.
Met. From these results, the molar fraction of the two comonomers in poly (benzyl methacrylate-co-2-ethylhexyl methacrylate) was 0.1% for benzyl methacrylate.
73, 2-ethylhexyl methacrylate is 0.2
It turned out to be 7.

The poly (benzyl methacrylate)
Gel permeation chromatography of (co-2-ethylhexyl methacrylate) was measured. Calibration was performed using tetrahydrofuran as a solvent and polystyrene as a standard. As a result, the poly (benzyl methacrylate-co-2-ethylhexyl methacrylate) had a weight average molecular weight Mw of 88,800 and a number average molecular weight Mn of 37,100. Further, the molecular weight distribution Mw / Mn was 2.42.

[0071]

Reference Example 10 Preparation of polybutyl methacrylate 14.22 g (0.1 mol) of butyl methacrylate and 164 mg of AIBN were dissolved in 100 ml of tetrahydrofuran at 20 ° C.
The solution was purged with nitrogen for 1 hour. The solution was then heated to reflux at 65 ° C. for 7 hours. During reflux, the solution was purged with nitrogen to keep oxygen out. 20 solution
After cooling to <RTIgt; C, </ RTI> the solution was poured into one liter of methanol, resulting in the precipitation of poly (butyl methacrylate). To further increase the purity of the poly (butyl methacrylate), the poly (butyl methacrylate) was dissolved in 50 ml of methylene chloride and subsequently precipitated with 800 ml of methanol. Finally, the viscous poly (butyl methacrylate) was collected and dried at 60 ° C. in vacuo. After drying, a thin layer chromatography test was performed to detect residual monomers in the resulting poly (butyl methacrylate), but the poly (butyl methacrylate) contained no residual monomers. Did not. 8.44 g of colorless and transparent poly (butyl methacrylate) was finally obtained. A 5% by weight cyclohexanone solution of this poly (butyl methacrylate) was prepared and spin-coated on a silicon substrate to form a thin film, and the refractive index was measured by a three-wavelength automatic ellipsometer Out manufactured by Rudol Research Co., Ltd.
o When measured by EL IV NIR III, 23 ° C
Was 1.480. Elemental analysis of this poly (butyl methacrylate) gave the following results. Note that poly (butyl methacrylate) is C ₈ H ₁₄ O ₂
And the molecular weight was calculated as 142.2. In addition, gel permeation chromatography of this poly (butyl methacrylate) was measured. Calibration was performed using tetrahydrofuran as a solvent and polystyrene as a standard. As a result, the weight average molecular weight Mw of this poly (butyl methacrylate) was 45,
000, and the number average molecular weight Mn was 22,500. Further, the molecular weight distribution Mw / Mn was 2.0.

[0072]

Example 11 Poly (2-ethylhexyl methacrylate )
Preparation of -co-glycidyl methacrylate ) thin film 1.0 g of poly (2-ethylhexyl methacrylate-co-glycidyl methacrylate) and 0.201 g (1.015 mmol) of 4,4'-diaminodiphenylmethane were added to cyclohexanone. To make the total amount 20 grams. This solution is dropped on a silicon substrate, and 4000
Spin coating was performed by rotating at 30 rpm for 30 seconds.
After drying the film in a vacuum at 60 ° C. for 2 hours,
The polymer was crosslinked by heating at 150 ° C. for 2 hours. Thus, a thin film of insoluble poly (2-ethylhexyl methacrylate-co-glycidyl methacrylate) having a thickness of 165.0 nm was obtained.

[0073]

Embodiment 12 Organic chemical vapor by interference amplification reflection method
Using chemical substance detection polymer film of detecting the present invention, in the same manner as in Example 6 by interference enhanced reflection method (IER method), gasoline and diesel, as well as other organic solvents were detected optically at room temperature . Table 2 shows the polymers used.
Shown in The organic chemicals used in this example were gasoline, diesel, acetone, dichloromethane, diethyl ether, ethanol, hexane and toluene. In addition, poly (2-ethylhexyl methacrylate-
The response to gasoline using a thin film of (co-glycidyl methacrylate) was recorded every 0.2 seconds and is shown in FIG.

[0074]

[Table 2]

CoP (BZMA-EHMA) and CoP (EHMA-GLMA) in the table are examples of the present invention. PBMA and PTHFMA are reference examples. The symbols in the table represent the following polymers. CoP (BZMA-EHMA): poly (benzyl methacrylate-co-
(2-ethylhexyl methacrylate) (benzyl methacrylate: 2-ethylhexyl methacrylate = 0.73: 0.27) CoP (EHMA-GLMA): poly (2-ethylhexyl methacrylate-co-glycidyl methacrylate) (2 methacrylic acid) -Ethylhexyl: glycidyl methacrylate = 0.5: 0.5) PBMA: poly (butyl methacrylate) PTHFMA: poly (tetrahydrofurfuryl methacrylate) As can be seen from FIG. Could be detected.

As is clear from the results shown in Table 2, the measurement sensitivities differed depending on the types of chemical substances. Therefore, various chemical substances can be measured simultaneously by using a plurality of films in combination.

[0077]

[Reference Example 13] Hydrocarbon vaporization by surface plasmon resonance method
In order to obtain an optimum coupling between incident light having a wavelength of 632.8 nm and a surface plasmon, a silver thin film having a thickness of 50 nm was formed on a slide glass substrate by vacuum evaporation. Poly (2-ethylhexyl methacrylate-co-styrene) having a concentration of 2.5% by weight dissolved in cyclohexanone was spin-coated on the surface of the silver thin film. The thickness of the resulting polymer film was about 50 nm. The thickness of the polymer film was dependent on the spin speed. After the spin coating was completed, the polymer film was dried under vacuum at around the glass transition temperature of the polymer.

FIG. 2 shows an outline of the SPR measuring apparatus. He
The -Ne laser light 1 is split by the beam splitter 2 and then P-polarized by the polarizer 3, then enters a flint glass right-angle prism 4 (n = 1.745) and couples with the silver thin film 5. The prism 4 was arranged on a slide glass (n = 1.5143). The prism 4 and the slide glass were filled with immersion oil (n = 1.514) in order to match the refractive indices. The prism-glass / silver thin film / polymer film assembly was placed in the flow-through cell (not shown) with the surface of the polymer film 6 facing the inside of the cell. The critical angle of the surface plasmon was determined by variously changing the incident angle of the laser beam 1. The angle of incidence was set to a value that approximately corresponded to the half-maximal intensity on one side of the resonance. This is shown in FIG. With gasoline and other hydrocarbon vapors flowing through the flow-through cell, the intensity of the reflected light was monitored by a photodetector at room temperature. The hydrocarbons used were toluene, gasoline, hexane and diesel oil. Thus, a change in the thickness of the polymer film or a change in the refractive index due to the interaction between the hydrocarbon vapor and the polymer film 6 could be measured with high sensitivity. Table 3 shows the results. Numerical values in the table represent relative changes in the intensity of the reflected light in percentage.

As is clear from Table 3, the measurement sensitivity varied depending on the type of hydrocarbon. In particular, it should be noted that the sensitivity of gasoline and diesel oil differ by one order of magnitude.

[0080]

[Table 3]

[Brief description of the drawings]

FIG. 1. Poly (2-ethylhexyl methacrylate-co)
FIG. 4 is a diagram showing a response to gasoline when gasoline is detected by an IER method using a thin film of (glycidyl methacrylate).

FIG. 2 is a schematic diagram of a chemical substance detector by the SPR method.

FIG. 3 is a diagram illustrating a relationship between an incident angle and the intensity of reflected light in the SPR method.

[Description of Signs] 1 He-Ne laser beam 2 Beam splitter 3 Polarizer 4 Right angle prism 5 Silver thin film 6 Polymer film 7 Photodetector for reference light 8 Photodetector for signal light 9 Electronic circuit 10 Recording means

Continued on the front page (72) Inventor Yuan Liu 29-1 Wakita Honcho, Kawagoe-shi, Saitama Prefecture Toa-Kawagoe Mansion 303 (72) Inventor Shizuo Ogura 1384-123, Oji, Tsurugashima-shi, Saitama Prefecture (72) Inventor Tetsu Yamamoto 1982-11 Toyodamoto, Kawagoe-shi, Saitama Prefecture Happy Heights 201 (72) Inventor Akihiko Tsuneda 3-1-117 Isehara-cho, Kawagoe-shi, Saitama (72) Inventor Kenji Motosugi 13-5 Shukita, Wakita Shinmachi, Kawagoe-shi, Saitama Room No. 202 Brown (56) References JP-A-4-326047 (JP, A) JP-A-2-19345 (JP, A) JP-A-2-167449 (JP, A) JP-A-2-238352 (JP, A A) JP-A-54-12893 (JP, A) JP-A-61-167854 (JP, A) JP-A-3-233348 (JP, A) JP-A-6-82431 (JP, A) -501022 (JP, A) US Patent No. 5015843 (US, A) Collection of Polymers, Vol. 46, No. 3 (1989), p. 177-181 (58) Field surveyed (Int. Cl. ⁷ , DB name) C08J 5/18 C08F 220/18 G01N 33/22

Claims (4)

(57) [Claims] 1. A chemical substance detection film containing a methacrylate-methacrylate copolymer comprising the following repeating unit (I). Embedded image (Wherein X represents —CH ₃ , R ¹ represents — (C ＝ O) —O—R ² , and R ² represents the same or different linear alkyl group, branched alkyl group, and cycloalkyl group. Represents an alkyl group, an unsaturated hydrocarbon group, an aryl group, a saturated or unsaturated heterocycle, or a substituted product thereof.) 2. The film according to claim 1, wherein said film has a thickness of less than 1 μm. 3. The chemical substance detecting film according to claim 1, wherein the copolymer is crosslinked. 4. A chemical substance detector comprising the chemical substance detection film according to claim 1 and detecting gasoline and diesel oil separately.