JP5588281B2 - Gas generating agent and micro pump - Google Patents

Description

  The present invention relates to a gas generating agent and a micropump, and more particularly to a gas generating agent for a micropump used in a microfluidic device and a micropump using the same.

  In recent years, analyzers using microfluidic devices have come to be used as analyzers that are small and have excellent portability. In the analysis apparatus using the microfluidic device, the sample can be fed, diluted, analyzed, and the like in the microchannel. For this reason, according to the analyzer using a microfluidic device, an effect that analysis can be performed even with a very small amount of sample can be obtained.

  As described above, in the microfluidic device, it is necessary to send a sample, a diluent, or the like through the microchannel. Therefore, a pump is essential for the microfluidic device. Conventionally, a syringe pump or the like has been used as the pump. However, the syringe pump is large and needs to be externally connected to the microfluidic device. Therefore, when the syringe pump is used, there arises a problem that the analyzer using the microfluidic device is enlarged and the portability of the analyzer is deteriorated.

  In view of such a problem, for example, the following Patent Document 1 includes a substrate in which a gas generation chamber connected to a microchannel is defined, and an azo compound and a binder resin are provided in the gas generation chamber. A micropump in which a gas generating agent is contained has been proposed. In this micro pump, gas is generated from the gas generating agent by supplying thermal energy to the gas generating agent, and the pump function is manifested by supplying the gas to the micro flow path.

  Unlike the syringe pump, the micro pump described in Patent Document 1 can be downsized because it does not require an actuator. In addition, since the micropump can be formed integrally with the microfluidic device, the portability of the analyzer using the microfluidic device is not impaired.

JP 2009-84128 A

  In recent years, there has been an increasing demand for imparting more advanced functions and more functions to microfluidic devices. Specifically, for example, there is an increasing demand for forming a multistage dilution series in a microfluidic device, and a desire for measuring a plurality of samples with one microfluidic device. In order to satisfy such a demand, the structure of the microfluidic device is becoming more and more complicated. Accordingly, there is an increasing demand for extending the driving time of the micropump.

  This invention is made | formed in view of this point, The objective is to provide the micropump which has the gas generating agent which can lengthen the drive time of a micropump, and long drive time.

  As a result of intensive studies, the present inventors have found that among various azo compounds and azide compounds, dimethyl-2,2′-azobis (2-methylpropionate) has high compatibility with the binder, I found that I can do a lot. As a result, the present inventors came to make this invention.

  That is, the gas generating agent according to the present invention relates to a gas generating agent used in a micropump for supplying gas to a microchannel of a microfluidic device. The gas generator for a micropump according to the present invention contains dimethyl-2,2'-azobis (2-methylpropionate) and a binder resin.

  In the present invention, “microfluidic device” refers to a device having a microchannel. The “microchannel” refers to a channel formed in a shape and dimension that develops a so-called micro effect in the liquid flowing through the microchannel. Specifically, the term “microchannel” means that the liquid flowing through a microchannel is strongly affected by surface tension and capillary action, and has a different shape from that of a liquid flowing through a normal channel. It refers to the flow path that is formed.

  In a specific aspect of the gas generant according to the present invention, dimethyl-2,2′-azobis (2-methylpropionate) is in the range of 100 parts by weight to 2000 parts by weight with respect to 100 parts by weight of the binder resin. Contained.

  In another specific aspect of the gas generating agent according to the present invention, the binder resin is made of acrylic resin, polyurethane resin, polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, polyether resin, polycarbonate resin, polyamide resin, and polyimide resin. One or more resins selected from the group consisting of: According to this structure, more dimethyl-2,2'-azobis (2-methylpropionate) can be contained. Therefore, the driving time of the micropump can be made longer.

  The micropump according to the present invention includes a base material and a gas generating material. A microchannel is formed on the substrate. The gas generating material supplies gas to the microchannel. The gas generating material includes a gas generating agent containing dimethyl-2,2'-azobis (2-methylpropionate) and a binder resin. That is, in the micropump according to the present invention, the gas generating material includes the gas generating agent according to the present invention. Therefore, the micropump according to the present invention has a long driving time.

  In a specific aspect of the micropump according to the present invention, the microchannel is open to the surface of the substrate. The gas generating material is provided on the surface of the substrate so as to cover the opening of the microchannel. In this case, it is not necessary to provide a gas generation chamber in the substrate. Accordingly, the substrate can be reduced in size and the substrate can be easily manufactured.

  In another specific aspect of the micropump according to the present invention, the base material is further formed with a gas generation chamber having an open microchannel. The gas generating material is disposed in the gas generating chamber. According to this configuration, the gas generated from the gas generating material can be efficiently guided to the microchannel.

  In the gas generating agent according to the present invention, dimethyl-2,2'-azobis (2-methylpropionate) having high compatibility with the binder resin is used as a gas generating component. For this reason, the drive time of a micropump can be lengthened by using this gas generating agent for micropumps.

1 is a schematic cross-sectional view of a micropump according to a first embodiment. It is a schematic sectional drawing of the micropump which concerns on 2nd Embodiment. It is a schematic sectional drawing of the micropump used in order to evaluate the output characteristic of a micropump in an Example and a comparative example.

  Hereinafter, a preferred embodiment in which the present invention is implemented will be described using the micropumps 1 and 2 shown in FIGS. 1 and 2 as examples. However, the micropumps 1 and 2 are merely examples. The present invention is not limited to the micropumps 1 and 2 at all.

(First embodiment)
FIG. 1 is a schematic cross-sectional view of the micropump according to the first embodiment.

  A micropump 1 shown in FIG. 1 is a pump for supplying gas to a microchannel of a microfluidic device. The micropump 1 is used in a state where the microchannel 11 of the micropump 1 is connected to the microchannel of the microfluidic device. The micropump 1 may be formed integrally with the microfluidic device.

  The micropump 1 includes a base material 10. As long as the base material 10 has low reactivity with the liquid or gas flowing through the microchannel 11 and has sufficient mechanical durability against the pressure applied when the liquid flows through the microchannel 11. In particular, it is not limited. The base material 10 can be formed of, for example, resin, glass, ceramic, or the like. Examples of the resin preferably used for forming the substrate 10 include an organic siloxane compound. Specific examples of the organic siloxane compound include polydimethylsiloxane (PDMS) and polymethylhydrogen siloxane.

  A microchannel 11 is formed in the base material 10. The microchannel 11 is open to the surface 10 a of the substrate 10.

  A gas generating layer 12 as a gas generating material is formed on the surface 10a. The gas generation layer 12 covers the opening 11 a of the microchannel 11. For this reason, the gas generated in the gas generation layer 12 is supplied into the microchannel 11 from the opening 11a.

  The gas generation layer 12 is preferably provided so that the gas generated in the gas generation layer 12 is suitably supplied to the microchannel 11. Therefore, the gas generating layer 12 is preferably adhered or bonded to the substrate 10. In this case, the gas generating layer 12 and the substrate 10 may be adhered or adhered using an adhesive or an adhesive, or the gas generating layer 12 and the substrate 10 may be adhered or adhered to at least one surface. The gas generating layer 12 and the base material 10 may be directly adhered or bonded by providing the function.

  The thickness of the gas generation layer 12 is not particularly limited. The thickness of the gas generation layer 12 can be, for example, about 10 μm to 200 μm.

  The surface of the gas generation layer 12 opposite to the substrate 10 is covered with a gas barrier layer 13. The gas barrier layer 13 is a layer that suppresses the gas generated in the gas generation layer 12 from flowing out to the side opposite to the substrate 10 and efficiently supplies the gas to the microchannel 11 side. For this reason, it is preferable that the gas barrier layer 13 has a low permeability of the gas generated in the gas generation layer 12.

  Specifically, the gas barrier layer 13 is made of, for example, polyacryl, polyolefin, polycarbonate, vinyl chloride resin, ABS resin, polyethylene terephthalate (PET) resin, nylon resin, urethane resin, polyimide resin, and glass. Is preferred.

  In addition, the thickness of the gas barrier layer 13 is preferably, for example, 25 μm to 100 μm, and more preferably 50 μm to 100 μm.

  In the present embodiment, the gas generating layer 12 as a gas generating material includes a gas generating agent containing a binder resin and dimethyl-2,2'-azobis (2-methylpropionate). Dimethyl-2,2'-azobis (2-methylpropionate) is highly compatible with the binder resin. For this reason, the content of dimethyl-2,2'-azobis (2-methylpropionate) in the binder resin can be increased. Specifically, dimethyl-2,2'-azobis (2-methylpropionate) can be contained in an amount of 100 parts by weight or more based on 100 parts by weight of the binder resin. Therefore, the content of dimethyl-2,2′-azobis (2-methylpropionate) in the gas generation layer 12 can be increased. Therefore, the amount of gas that can be generated from the gas generation layer 12 can be increased. Therefore, the drive period of the micropump 1 can be lengthened.

  From the viewpoint of making the driving time of the micropump 1 longer, it is preferable that the content of dimethyl-2,2′-azobis (2-methylpropionate) with respect to the binder resin is further increased. Accordingly, dimethyl-2,2′-azobis (2-methylpropionate) is more preferably contained in an amount of 100 parts by weight or more with respect to 100 parts by weight of the binder resin, and is contained in an amount of 200 parts by weight or more. Is more preferable, and 400 parts by weight or more is more preferable. However, if the content of dimethyl-2,2'-azobis (2-methylpropionate) in the binder resin is too large, it may not be dissolved in the binder resin. Accordingly, dimethyl-2,2′-azobis (2-methylpropionate) is preferably contained in a ratio of 2000 parts by weight or less with respect to 100 parts by weight of the binder resin, and in a ratio of 1000 parts by weight or less. More preferably, it is contained in a proportion of 800 parts by weight or less.

  The binder resin is preferably one or more resins selected from the group consisting of acrylic resins, polyurethane resins, polyester resins, polyethylene resins, polypropylene resins, polystyrene resins, polyether resins, polycarbonate resins, polyamide resins and polyimide resins. It is done. Such a resin is more compatible with dimethyl-2,2'-azobis (2-methylpropionate). Therefore, the content of dimethyl-2,2'-azobis (2-methylpropionate) with respect to the binder resin can be increased. As a result, the driving time of the micropump 1 can be increased more effectively. As a binder resin more preferably used from the viewpoint of further effectively extending the driving time of the micropump 1. For example, an acrylic resin etc. are mention | raise | lifted.

(Second Embodiment)
FIG. 2 is a schematic cross-sectional view of the micropump according to the second embodiment.

  In the said 1st Embodiment, the example which provides the gas generation layer 12 on the surface 10a of the base material 10 as a gas generation material was demonstrated. However, the present invention is not limited to this configuration.

  For example, like the micropump 2 shown in FIG. 2, a gas generation chamber 14 in which the microchannel 11 is opened is formed inside the base material 10, and for example, a tablet-like gas is formed in the gas generation chamber 14 You may arrange | position the generating material tablet 12a.

Example 1
An acrylic copolymer (weight average molecular weight 700,000) of 96.5 parts by weight of 2-ethylhexyl acrylate, 3 parts by weight of acrylic acid, and 0.5 parts by weight of 2-hydroxyethyl acrylate was produced. Next, 100 parts by weight of the acrylic copolymer, 200 parts by weight of ethyl acetate, 3 parts by weight of an isocyanate compound (trade name Coronate L45, manufactured by Nippon Polyurethane Co., Ltd.), dimethyl-2,2′-azobis (2 -Methylpropionate) (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) and 3.5 parts by weight of diethylthioxanthone (Ciba Specialty Chemicals, DETX-S) were mixed to produce a gas generating agent. Obtained.

  Next, a gas generating film composed of the PET film and the gas generating layer 12 is formed by applying a gas generating agent on a polyethylene terephthalate (PET) film having a thickness of 50 μm to which an anchor treatment has been applied, and drying. Produced. The thickness of the gas generation layer after drying was about 100 μm. In this embodiment, the PET film constitutes the gas barrier layer 13.

  Next, as shown in FIG. 3, since the gas generating film 17 has adhesiveness, the base material 10 in which the microchannels 11 that are open on both the main surfaces 10 a and 10 b are formed. A micropump was fabricated by pasting on the surface 10a.

  In the present embodiment, the base material 10 was formed from an acrylic plate. The cross-sectional shape of the microchannel 11 was a 0.5 mm square shape. The length of the microchannel 11 was 800 mm. The tip of the microchannel 11 was opened to the atmosphere.

(Example 2)
A gas generating film was produced in the same manner as in Example 1 except that the amount of dimethyl-2,2′-azobis (2-methylpropionate) was 400 parts by weight, and a micropump was produced.

(Example 3)
A gas generating film was produced in the same manner as in Example 1 except that the amount of dimethyl-2,2′-azobis (2-methylpropionate) was 800 parts by weight, and a micropump was produced.

Example 4
A gas generating film was produced in the same manner as in Example 1 except that the amount of dimethyl-2,2′-azobis (2-methylpropionate) was 2000 parts by weight, and a micropump was produced.

(Comparative Example 1)
The above except that 40 parts by weight of 2,2′-azobis (N-butyl-2-methylpropionamide) was used instead of 400 parts by weight of dimethyl-2,2′-azobis (2-methylpropionate). A gas generating film was produced in the same manner as in Example 1 to produce a micropump.

(Comparative Example 2)
100 parts by weight of 2,2′-azobis (N-butyl-2-methylpropionamide), 100 parts by weight of an acrylic copolymer prepared in the same manner as in Example 1, 200 parts by weight of ethyl acetate, and isocyanate type An attempt was made to mix 3 parts by weight of a compound (manufactured by Nippon Polyurethane, trade name Coronate L45) and 3.5 parts by weight of diethylthioxanthone (manufactured by Ciba Specialty Chemicals, DETX-S). However, 2,2′-azobis (N-butyl-2-methylpropionamide) was not dissolved in the acrylic copolymer, and a gas generating film could not be obtained.

(Evaluation of micro pump output characteristics)
The output characteristics of the micropumps produced in Example 1 and Comparative Example 1 were evaluated in the following manner. First, 1 μl of water is injected into the microchannel 11 from the opening 11b, and then the opening 11b is sealed with a single-sided tape 16 comprising a 30 μm thick acrylic adhesive layer and a 30 μm thick polyethylene terephthalate substrate. did. In this state, UV light having a wavelength of 380 nm was irradiated using an LED, and the moving time and moving distance of the water droplet 15 were measured every 10 seconds. From the result, the moving speed of the water droplet 15 was calculated. Moreover, the movement time which can maintain 90% of the maximum value of movement speed was calculated as a stable time, and the movement time which can maintain 60% was calculated as duration. The results are shown in Table 1 below.

  From the results shown in Table 1 above, by using dimethyl-2,2′-azobis (2-methylpropionate) as a gas generating component, the amount of gas generated can be increased and the driving time of the micropump can be extended. I can see that From the viewpoint of extending the driving time of the micropump, it is preferable to contain 400 parts by weight or more of dimethyl-2,2′-azobis (2-methylpropionate) with respect to 100 parts by weight of the binder resin, and 800 weights. It turns out that it is more preferable to make it contain more than part.

DESCRIPTION OF SYMBOLS 1, 2 ... Micro pump 10 ... Base material 10a, 10b ... Main surface 11 of base material ... Micro flow path 11a, 11b ... Opening 12 ... Gas generating layer 12a ... Gas generating material tablet 13 ... Gas barrier layer 14 ... Gas generating chamber 15 ... water droplet 16 ... seal 17 ... gas generating film

Claims (6)

A gas generating agent used in a micropump for supplying gas to a microchannel of a microfluidic device,
A gas generator for a micropump containing dimethyl-2,2'-azobis (2-methylpropionate) and a binder resin.   The dimethyl-2,2'-azobis (2-methylpropionate) is contained in a range of 100 parts by weight to 2000 parts by weight with respect to 100 parts by weight of the binder resin. Gas generator for micro pumps.   The binder resin is one or more resins selected from the group consisting of acrylic resins, polyurethane resins, polyester resins, polyethylene resins, polypropylene resins, polystyrene resins, polyether resins, polycarbonate resins, polyamide resins, and polyimide resins. Item 3. A gas generator for a micropump according to Item 1 or 2. A substrate on which a microchannel is formed;
A gas generating material for supplying gas to the microchannel;
With
The gas generating material is a micropump including a gas generating agent containing dimethyl-2,2′-azobis (2-methylpropionate) and a binder resin. The microchannel is open on the surface of the substrate,
The micropump according to claim 4, wherein the gas generating material is provided on a surface of the base material so as to cover an opening of the microchannel. The base is further formed with a gas generation chamber in which the microchannel is open,
The micro pump according to claim 4, wherein the gas generating material is disposed in the gas generating chamber.

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