JP4660799B2 - Polymer sample analyzer - Google Patents

Description

  The present invention relates to a polymer sample analyzer for analyzing deterioration of a polymer material such as plastic by light.

  Polymer materials such as natural rubber and plastic play an important role in modern society along with metal materials such as steel. The polymer material is indispensable for life as a material for various films, fibers, containers, and the like.

  By the way, it is known that when the polymer material is used for a long period of time, its physical and chemical characteristics gradually deteriorate due to external factors. The cause of the deterioration is mainly heat, light, mechanical stress, and the like, and further due to biological and chemical reactions. Among these, the deterioration due to light is considered to be caused by the polymer structure being cleaved by the energy of light, and the radicals that accompany the cleavage cause an oxidative chain reaction (for example, see Non-Patent Documents 1 to 3). ).

  Conventionally, a test for deterioration due to light has been performed by exposing a polymer material to actual sunlight outdoors, or using a weather meter to irradiate a light beam close to sunlight with an arc lamp. Moreover, when using a weather meter, it may humidify simultaneously with the irradiation of the light of the said arc lamp.

  However, it takes months or years to obtain results when the polymer material is exposed to the outdoors, and in the case of a weather meter, it requires a large amount of equipment and a large amount of money, and until the results are obtained. The problem is that it takes several weeks to several months. In addition, the results obtained by the test are those in which the deterioration state of the sample surface is observed visually or under a microscope, or are related to mechanical properties such as tensile strength after deterioration, and the polymer constituting the polymer material There is a problem that chemical knowledge about the progress mechanism of deterioration of various additives such as an antioxidant and an ultraviolet absorber contained in itself or in the polymer material cannot be obtained.

  In order to solve the above problem, there has been proposed a polymer sample analyzer for detecting a gas generated by degradation and degradation of a polymer sample by irradiating ultraviolet rays (see, for example, Patent Document 1).

  The polymer sample analyzer includes: a gas phase component generating means for generating a plurality of gas phase components from the polymer sample; a carrier gas introducing means for introducing a carrier gas into the gas phase component generating means; A separation column for separating the plurality of gas phase components introduced from the gas phase component generating means into individual gas phase components, a detector for detecting the gas phase components separated by the separation column, and a sample container. And an optical fiber for irradiating the polymer sample guided to the gas phase component generating means with ultraviolet rays.

  In the polymer sample analyzer, first, a thin film made of a polymer sample such as polystyrene is formed at the bottom of the sample container, and the sample container is placed at the upper end of a quartz tube disposed in the housing of the gas phase component generating means. Insert from the part into a predetermined position inside. The lower end of the quartz tube is connected to a separation column. Next, an optical fiber is inserted from the upper end of the quartz tube, and the polymer sample in the sample container is irradiated with ultraviolet rays. As a result, the polymer sample is decomposed by light, oxidation, and thermal degradation to generate a plurality of gas phase components. Next, a carrier gas is introduced into the housing by the carrier gas introduction means, and a plurality of gas phase components are introduced into the separation column from the lower end of the quartz tube by the carrier gas. Next, the plurality of gas phase components are separated into individual gas phase components by the separation column, and the separated individual gas phase components are detected by a detector such as a quadrupole mass spectrometer. As a result, according to the polymer sample analyzer, many useful chemical findings can be obtained regarding the photodegradation of the polymer sample in the natural environment.

However, this polymer sample analyzer may not be able to obtain reproducibility of analysis results, and further improvement is desired.
JP 2007-0117196 A "Written by Wolfram Schnable, translated by Junkichi Soma," Degradation of Polymers: Principles and Their Applications ", Yukabo, 1993 Fumio Ide, “Practical polymer materials that can be identified by characteristics”, Industrial Research Committee, 2002 N. Grassie, "Developments in Polymer Degradation-7", Elsevier Applied Science, 1987

  In view of such circumstances, an object of the present invention is to provide a polymer sample analyzer capable of reliably obtaining reproducibility of analysis results.

In order to achieve the above object, the present invention provides a gas phase component generating means for generating a plurality of gas phase components from a polymer sample, and a carrier gas introducing means for introducing a carrier gas into the gas phase component generating means. Separation means for separating the plurality of gas phase components introduced from the gas phase component generation means by the carrier gas into individual gas phase components, and detection for detecting individual gas phase components separated by the separation means And an ultraviolet irradiation means for irradiating the polymer sample contained in the sample container and guided to the gas phase component generation means with ultraviolet rays, and the polymer sample is deteriorated by the ultraviolet irradiation by the ultraviolet irradiation means. A plurality of gas phase components generated by decomposition are introduced into the separation means by the carrier gas, separated into individual gas phase components by the separation means, and the separated individual gas phase components are separated by the detection means. In the polymer sample analyzer and out, and presence of the predetermined distance from said ultraviolet light irradiation means comprises a distance maintaining member for holding the sample container, said ultraviolet light irradiation means is a protective member for covering and protecting the irradiation unit The distance holding member is a tapered portion provided at the distal end portion of the protection member and having a diameter reduced from the ultraviolet irradiation means side toward the distal end, and the sample container is formed from the distal end portion of the tapered portion. And having a diameter that is smaller than the base end portion of the taper portion and is fitted to the taper portion, and further includes a through hole that penetrates the vessel wall in the thickness direction .

  According to the present invention, since the sample container is held by the distance holding member at a predetermined distance from the ultraviolet irradiation means, the polymer sample accommodated in the sample container by the ultraviolet irradiation means When irradiating ultraviolet rays, the irradiation amount and irradiation intensity of the ultraviolet rays irradiating the polymer sample can always be kept constant. Therefore, the reproducibility of the analysis result can be obtained with certainty.

By the way, when the plurality of gas phase components generated from the polymer sample by the gas phase component generating means adhere to the irradiation part of the ultraviolet irradiation means, the irradiation amount and irradiation intensity of the ultraviolet rays irradiated from the ultraviolet irradiation means. May decrease and analysis may not be performed reliably. Therefore, the ultraviolet irradiation unit, Ru provided with a protective member for covering and protecting the irradiation unit.

At this time, the distance holding member is a tapered portion provided at the distal end portion of the protective member and having a diameter reduced from the ultraviolet irradiation means side toward the distal end, and the sample container is a distal end portion of the tapered portion. than the proximal end portion of the large diameter and the tapered portion than a small diameter provided with a bore which is fitted in the tapered portion, Ru provided with a through hole passing through the wall in the thickness direction.

  According to the above configuration, when the mouth portion of the sample container is externally fitted to the taper portion of the protection member that is the distance holding member, the diameter is larger than the tip portion of the taper portion and the taper portion is tapered. Since the diameter of the sample container is smaller than that of the base end portion, the sample container is locked at a position corresponding to the diameter between the distal end portion and the s end portion in the tapered portion. Therefore, the sample container is always held at a predetermined distance from the ultraviolet irradiation means by the distance holding member, and the reproducibility of the analysis result can be obtained with certainty.

  By the way, when the mouth of a sample container that does not have a through-hole penetrating in the thickness direction in the vessel wall as is normally used, the tapered portion of the protection member that is the distance holding member is externally fitted. Since there is no path for deriving the plurality of gas phase components generated from the polymer sample accommodated in the sample container to the outside of the sample container, the plurality of gas phase components are detected by the detection means. Cannot be detected. However, in the above configuration, the sample container includes a through-hole penetrating the vessel wall in the thickness direction. Therefore, the carrier gas introduction unit introduces the sample container into the gas phase component generation unit through the through-hole. By allowing carrier gas or the like to flow through the sample container, the plurality of vapor phase components can be led out of the sample container.

  Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 is an explanatory cross-sectional view showing a configuration example of the polymer sample analyzer of the present invention, and FIG. 2 is an enlarged view showing a main part of the polymer sample analyzer shown in FIG.

  As shown in FIG. 1, the polymer sample analyzer 1 of the present embodiment is a gas phase component that generates a plurality of gas phase components from a sample made of a polymer material such as plastic (hereinafter abbreviated as a polymer sample). Generation means 2, gas introduction means 3 for introducing a carrier gas or a predetermined atmospheric gas into the gas phase component generation means 2, separation means 4 for introducing the gas phase components and separating them into individual gas phase components, and separation And detecting means 5 for detecting individual gas phase components separated by the means 4. The gas phase component generation unit 2 is connected to the separation unit 4 via the sample introduction unit 6.

  The gas phase component generating means 2 includes a quartz tube 8 disposed in the housing 7 and a heater 9 disposed on the outer peripheral side of the quartz tube 8. In the quartz tube 8, the sample container 10 can be inserted from the upper end portion, and the lower end portion is connected to the sample introduction portion 6. Further, the inner diameter of the lower end portion of the quartz tube 8 is smaller than the inner diameter of the upper end portion, and a reduced diameter portion (not shown) formed between the upper end portion side and the lower end portion side. The sample container 10 can be placed on the surface. As such a gas phase component generation means 2, for example, a vertical micro electric furnace type pyrolyzer (trade name: PY-2020iD) manufactured by Frontier Laboratories may be used.

  The gas phase component generation means 2 of this embodiment further includes an ultraviolet irradiation means 11. The ultraviolet irradiation means 11 includes a light source 12 such as a deuterium lamp, an optical filter 13 that selectively transmits only ultraviolet light having a wavelength of 400 nm or less among light emitted from the light source 12, and an optical fiber 14 connected to the optical filter 13. And. The optical fiber 14 includes a protective member 15 at a portion inserted into the quartz tube 8, and the sample container 10 is attached to the tip of the protective member 15. In the ultraviolet irradiation means 11, the optical fiber 14 is inserted from the upper end of the quartz tube 8 with the sample container 10 attached, and the polymer sample accommodated in the sample container 10 is irradiated with ultraviolet light from the optical fiber 14. ing.

  The gas introduction means 3 includes a carrier gas source 16 such as helium and an atmospheric gas source 17 such as helium, nitrogen, oxygen, air, humidified air. The carrier gas source 16 and the atmospheric gas source 17 are connected to the gas switching device 18 via the carrier gas conduit 16a and the atmospheric gas conduit 17a, respectively. The gas switching device 18 is connected to the gas phase via the gas conduit 19. It is connected to the component generation means 2. The gas conduit 19 is opened above the quartz tube 8 in the housing 7 of the gas phase component generating means 2.

  The separation means 4 includes an oven 20 capable of adjusting the temperature and a separation column 21 such as a capillary column disposed in the oven 20. The detecting means 5 includes a detector 22 such as a quadrupole mass spectrometer. For example, a GC / MS system (trade name: Model 5975 GC / MS system) manufactured by Hewlett-Packard Company can be used as an apparatus including the separation unit 4 and the detection unit 5.

  The sample introduction unit 6 has a lower end portion of the quartz tube 8 connected to the upper end portion and a separation column 21 connected to the lower end portion, and a split vent tube 23 between the upper and lower end portions. The split vent pipe 23 discharges a part of the gas phase component introduced from the quartz pipe 8 by opening the on-off valve 23a and releasing it to the atmosphere, so that an appropriate amount of the gas is supplied according to the sensitivity required for analysis. It acts as a flow rate adjusting means for introducing the phase component into the separation column 21.

  The optical fiber 14 of the ultraviolet irradiation means 11 is protected by a resin clad layer (not shown) covering the outer peripheral surface, but the tip inserted into the quartz tube 8 is as shown in FIG. In addition, the clad layer is peeled off to expose the glass core portion 14a. And the front end surface of the core part 14a comprises the irradiation part 14b of the ultraviolet irradiation means 11. FIG.

  The irradiation unit 14 b includes a protection member 15. The protective member 15 is a quartz glass cylindrical body 15a having an inner diameter into which the core portion 14a of the optical fiber 14 can be inserted, and a quartz glass welded to the opening end of the cylindrical body 15a to close the opening end. The irradiation part 14b is contact | abutted by the inner surface side of the plate 15b. In the present embodiment, the protective member 15 is a member in which the opening end of the cylindrical body 15a is closed by the plate body 15b. However, as shown in FIG. 2B, the tip of the cylindrical body 15a is used. You may use what closed this opening edge part by rounding a part.

The sample container 10 attached to the front end portion 15c of the protection member 15 is made of stainless steel and is inactivated by forming a SiO ₂ layer on the surface. The mouth portion 10a of the sample container 10 has a diameter D that is larger in diameter than the distal end portion 15e of the tapered portion 15d of the protective member 15 and smaller in diameter than the proximal end portion 15f of the tapered portion 15d, and is fitted on the tapered portion 15d. Has been. The sample container 10 includes a through hole 10b that penetrates the vessel wall in the thickness direction.

  A gas phase component concentration unit 24 is provided on the outer peripheral side of the separation column 21 on the sample introduction unit 6 side, and the separation column 21 is inserted into the gas phase component concentration unit 24. In the gas phase component concentrating unit 24, a refrigerant injection nozzle 25 that injects, for example, liquid nitrogen as a refrigerant is attached in a direction orthogonal to the separation column 21 that is inserted. The refrigerant injection nozzle 25 is connected to a liquid nitrogen source 27 via a liquid nitrogen conduit 26.

  The refrigerant injection nozzle 25 injects liquid nitrogen into a portion of the separation column 21 that is inserted into the gas phase component concentrating unit 24 to cool the gas phase component introduced into the separation column 21 at the portion. Acts as a component cooling means. The gas phase component is trapped and concentrated in the portion inserted into the gas phase component concentrating portion 24 of the separation column 21 by being cooled by the refrigerant injection nozzle 25. As an apparatus provided with the said gaseous-phase component concentration part 24 and the refrigerant | coolant injection nozzle 25, the cooling trap apparatus (brand name: Microjet cryotrap apparatus) by Frontier Laboratories can be used, for example.

  In the polymer sample analyzer 1 shown in FIG. 1, only one atmosphere gas source 17 is shown. The atmosphere gas source 17 corresponds to each of the atmosphere gases such as helium, nitrogen, oxygen, and air. A plurality may be provided. In this case, the gas switching device 18 switches between the carrier gas and the plurality of atmospheric gases, or switches between one atmospheric gas and another atmospheric gas.

  Next, the operation of the polymer sample analyzer 1 of the present embodiment will be described by taking as an example the case where polystyrene is used as the polymer sample.

  The polymer sample is prepared, for example, by forming a thin film having a thickness of 0.1 mm or less with 60 μg of polystyrene on the inner bottom surface 10 c of the cup-shaped sample container 10.

  In the polymer sample analyzer 1, first, the gas introduced into the gas phase component generating means 2 is switched by the gas switching device 18, and the gas phase component is supplied from the atmosphere gas source 17 through the atmosphere gas conduit 17 a and the gas conduit 19. For example, humidified air is introduced into the generating means 2 as an atmospheric gas. Then, in the humidified air atmosphere, the optical fiber 14 is inserted from the upper end of the quartz tube 8 in a state where the sample container 10 is fitted on the tapered portion 15 d of the protective member 15, and the sample container 10 is inserted into the quartz tube 8. Place on the reduced diameter part.

  Next, the polystyrene is heated by the heater 9 while irradiating the polystyrene in the sample container 10 with ultraviolet rays by the ultraviolet irradiation means 11. The heating heater 9 gradually raises the temperature from room temperature, and heats the polystyrene at a temperature of about 100 ° C., for example. At this time, the humidified air introduced into the gas phase component generating means 2 flows into the sample container 10 through the through hole 10b, whereby the inside of the sample container 10 becomes the humidified air atmosphere.

  The polystyrene is irradiated with the ultraviolet rays in the humidified atmosphere and is heated to decompose by light, oxidation, and thermal degradation, thereby generating a plurality of gas phase components. The term “light / oxidation / thermal degradation decomposition” means photo-degradation degradation due to the ultraviolet rays, oxidation degradation degradation due to oxygen contained in the humidified air, and thermal degradation degradation due to heating of the heater 9 for heating. .

  Next, the humidified air introduced into the gas phase component generating means 2 flows into the sample container 10 through the through-hole 10b and flows out of the sample container 10 to thereby generate a plurality of pieces of polystyrene generated from the polystyrene. The gas phase component is led out of the sample container 10 through the through hole 10 b and introduced into the separation column 21 through the sample introduction unit 6. At this time, by opening the on-off valve 23a of the split vent pipe 23, the split vent pipe 23 is opened to the atmosphere, while the separation column 21 has a small inner diameter and thus becomes fluid resistance and is introduced into the separation column 21. The flow rate of the gas phase component is adjusted to an appropriate amount depending on the sensitivity required for analysis.

  Further, when the gas phase component is introduced into the separation column 21, liquid nitrogen is injected from the refrigerant injection nozzle 25, so that the gas component is inserted into the gas phase component concentrating part 24 of the separation column 21. The phase component is cooled and trapped in the part. As a result, the gas phase component is collected and concentrated in the portion of the separation column 21 inserted through the gas phase component concentrating unit 24, so that the low boiling point compound contained in the gas phase component is separated. Elution from the column 5 is prevented. Further, when the polymer sample such as polystyrene is heated at a temperature of about 100 ° C. by the heater 9, the degradation decomposition product is temporarily inserted into the portion inserted into the gas phase component concentration unit 24 of the separation column 21. All can be collected, and the separation accuracy by the separation column 21 can be improved.

  Next, the gas switching device 18 switches the gas introduced into the gas phase component generation means 2, and the carrier gas source 16 passes through the carrier gas conduit 16 a and the gas conduit 19 as a carrier gas to the gas phase component generation means 2. Introduce helium. At this time, if the humidified air supplied from the atmospheric gas source 17 flows into the separation column 21, the separation column 21 may be deteriorated. Therefore, the humidified air is sufficiently replaced with helium.

  Next, when the humidified air is sufficiently replaced with helium, the ultraviolet irradiation by the ultraviolet irradiation means 11 and the injection of liquid nitrogen from the refrigerant injection nozzle 25 are stopped, and the temperature of the oven 20 is raised. As a result, the gas phase component concentrated in the portion inserted into the gas phase component concentrating portion 24 of the separation column 21 is desorbed from the portion, and is separated into individual gas phase components by the separation column 21. The individual gas phase components are detected by the detection means 5. The detection result in the detection means 5 is output as a chromatogram or a mass spectrum.

  As described above, when a polymer sample is irradiated with ultraviolet light in a humidified air atmosphere and decomposed by light, oxidation, or thermal degradation, a reaction close to light degradation occurs in the natural environment. Many useful chemical findings can be obtained.

  Here, in the polymer sample analyzer 1 of the present embodiment, when the mouth portion 10a of the sample container 10 is fitted over the tapered portion 15d of the protective member 15, the diameter D is larger than that of the tip portion 15e of the tapered portion 15d. Since the sample container 10 has a large diameter and a smaller diameter than the proximal end portion 15f of the tapered portion 15d, the sample container 10 is engaged at a position corresponding to the diameter D between the distal end portion 15e and the proximal end portion 15f in the tapered portion 15d. Stopped. As a result, the sample container 10 is always held at a predetermined distance L from the optical fiber 14 by the tapered portion 15d of the protective member 15 that acts as a distance holding member. Therefore, when irradiating the polystyrene contained in the sample container 10 with the optical fiber 14 with ultraviolet rays, the irradiation amount and irradiation intensity of the ultraviolet rays radiated to the polystyrene can be always kept constant, so that the analysis results can be reproduced. Sexually can be obtained.

  Moreover, since the irradiation part 14b of the ultraviolet irradiation means 11 is coat | covered and protected by contact | abutting to the plate 15b of the protection member 15, the some produced | generated from the said polystyrene accommodated in the sample container 10 It is possible to prevent vapor phase components from adhering to the irradiation part.

  Moreover, since the protection member 15 consists of the cylindrical body 15a and the plate body 15b made from quartz glass, the plurality of pieces attached to the surface of the protection member 15 by heating at, for example, 500 to 600 ° C. with a burner or the like. Gas phase components can be removed and reused.

  Further, since the sample container 10 includes a through hole 10b penetrating the vessel wall in the thickness direction, the humidified air introduced into the gas phase component generating means 2 is circulated into the sample container 10 through the through hole 10b. Thus, a plurality of gas phase components generated from the polystyrene can be led out of the sample container 10 and reliably detected by the detection means 5.

  In the present embodiment, the gas introduction means 3 is provided with a carrier gas source 16 and a gas switching device 18 and introduced into the gas phase component generation means 2 after completion of the light / oxidation / thermal degradation decomposition of the polystyrene. The gas is switched from the atmospheric gas to the carrier gas so that the entire polymer sample analyzer 1 is replaced with the carrier gas. However, the gas switching device 18 may be provided between the sample introduction unit 6 and the separation column 21 so that only the inside of the separation column 21 is replaced with the carrier gas. In this case, the gas switching device 18 is constituted by a three-way valve, for example, and prevents the atmospheric gas introduced from the atmospheric gas source 17 into the gas phase component generating means 2 from being introduced into the separation column 21, The carrier gas supplied from the carrier gas source 16 connected to the switching device 18 is introduced into the separation column 21.

  Further, in this embodiment, humidified air is introduced as the atmospheric gas into the gas phase component generating means 2, but other gas may be introduced, or a carrier gas may be used instead of the atmospheric gas. Also good.

  Further, in the present embodiment, the ultraviolet rays are irradiated by the ultraviolet irradiation means 11 while heating the polystyrene in the sample container 10 by the heating heater 9, but it is not necessary to heat.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory sectional drawing which shows one structural example of the polymer sample analyzer of this invention. The enlarged view which shows the principal part of the polymer sample analyzer of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Polymer sample analyzer, 2 ... Gas phase component production | generation means, 3 ... Carrier gas introduction means, 4 ... Separation means, 5 ... Detection means, 10 ... Sample container, 10b ... Through-hole of sample container, 11 ... Ultraviolet irradiation Means, 14b ... Irradiation part of ultraviolet irradiation means, 15 ... Protection member, 15c ... Tip part of protection member, 15d ... Taper part of protection member, distance holding member, 15e ... Tip part of taper part, 15f ... Base of taper part End, D ... caliber.

Claims (1)

A gas phase component generating means for generating a plurality of gas phase components from the polymer sample;
Carrier gas introduction means for introducing a carrier gas into the gas phase component generation means;
Separation means for separating the plurality of gas phase components introduced from the gas phase component generation means by the carrier gas into individual gas phase components;
Detecting means for detecting individual gas phase components separated by the separating means,
An ultraviolet irradiation means for irradiating the polymer sample contained in the sample container and guided to the vapor phase component generation means with ultraviolet rays;
A plurality of gas phase components produced by degradation and decomposition of the polymer sample by ultraviolet irradiation by the ultraviolet irradiation means are introduced into the separation means by the carrier gas, and separated into individual gas phase components by the separation means, In the polymer sample analyzer for detecting the separated gas phase components by the detection means,
A distance holding member for holding the sample container at a predetermined distance from the ultraviolet irradiation means;
The ultraviolet irradiation means includes a protective member that covers and protects the irradiation portion,
The distance holding member is a tapered portion provided at the tip of the protection member and having a diameter reduced from the ultraviolet irradiation means side toward the tip.
The sample container has a diameter larger than the distal end portion of the taper portion and a smaller diameter than the proximal end portion of the taper portion, and has a diameter fitted on the taper portion, and penetrates the vessel wall in the thickness direction. A polymer sample analyzer comprising a through hole .

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