HK1088625B - Microdevice, micropore-array-board or resin-made pipette tip employing the same - Google Patents

Description

Micro-component, and micro-well array plate or resin pipette tip using the same

Technical Field

The present invention relates to a switch element suitable for use in a micro-machine; functional elements of micro-optics, micro-fluids, micro-chemical reaction devices, and the like; a capillary die of a blood fluidity measuring device; a micro bioreactor; a plate with a micropore array; a micro-injector; a micro resin pipette tip; the present invention relates to a resin composition for micro-parts (hereinafter referred to as "micro-parts") in other chemical, biochemical, bioengineering, and biological fields and applications thereof, and more particularly to a resin composition suitable for producing these micro-parts by an injection molding method.

Background

In the past, microdevices such as a microwell array plate, which require minute concave portions, were manufactured from silicon single crystals, and the minute concave-convex pattern shapes were formed by etching.

This method has problems of high material cost and long manufacturing time.

Further, the defective product generation rate is high, and there is a possibility that the test accuracy is lowered due to the unevenness of the shape of the formed fine uneven pattern.

Further, since these micro-components have a high unit price, they must be cleaned and reused after the test is completed, and there is a possibility that the test accuracy may be lowered due to insufficient washing.

Further, in the examination and analysis at the cellular level, accommodated lymphocytes having a diameter of about 10 μm are sucked one by one from specific wells (wells having a diameter of about 10 μm and a center-to-center distance of 20 μm) of a well array plate as shown in a microscopic photograph of FIG. 3, and the lymphocytes are injected into another container, and a pipette tip as a capillary is required.

The volume of 1 lymphocyte is about 1 pico liter (pl), and the volume of such a minute volume, minute diameter cell or test solution capillary (pipette tip) must reach the level of several tens of pico liters, and there are capillaries as follows.

As a nozzle capable of taking 1 cell with an inner diameter of about 15 μm, a glass capillary tube has been conventionally used.

However, it has the following problems.

However, when cells are collected mechanically at a high speed, the capillary (particularly the tip portion of the nozzle) is difficult to stand still by vibration, and thus, accurate cell collection operation cannot be performed.

The glass capillaries are not strong enough, and when they are brought into contact with and collided with a cell plate (for example, a microwell array plate), the capillaries are broken regardless of the cell plate material.

When a nozzle for taking cells is mechanically installed to automatically take cells continuously, the hole of the nozzle must be positioned at the center of the nozzle with high accuracy.

It is very difficult to form such a highly accurate shape of a glass capillary.

A nozzle for collecting cells, such as a pipette tip for processing a substance in a human living body, requires strict processing as a medical waste when the nozzle is discarded.

Glass capillaries are easily damaged and the damaged capillaries are dangerous.

Similarly, as a nozzle having an inner diameter of about 15 μm, which can take 1 cell, there is a nozzle made of artificial ruby in the related art.

However, it also has the following problems.

The final surface polishing of the artificial rubble nozzle must be manually performed by a high-grade technician, each requires a high price of 5 to 10 ten thousand yen, and is very difficult to mass-produce.

The nozzle for taking cells is used for processing substances in the living body of a human, and in this case, in order to prevent biohazard (bio-contamination) and contamination of a recovered sample, it is necessary to supply a sterilized nozzle in a sterile state, and each sample needs to be replaced, so that it is necessary to develop a nozzle capable of mass production at low cost.

The nozzle for collecting cells for treating human living body substances requires strict treatment as medical waste when it is discarded.

The artificial rubble nozzle cannot be handled with high strength and is very thin at its tip, which is also dangerous.

Therefore, if the micro component can be manufactured by the injection molding method, the micro component with stable quality can be produced in a large amount in a short time, the manufacturing cost can be controlled to be low, the micro component can be discarded after use, and the possibility of the reduction of the test accuracy caused by insufficient washing is avoided.

Various tests were conducted with a view to the advantages of the injection molding method.

In the conventional process for producing a micro part requiring fine irregularities, a stamper having a pattern of fine irregularities is mounted in a cavity of a mold, a molten resin is injected at high temperature and high pressure, cooled and solidified, and then taken out, and a resin plate taken out is transferred with a fine work formed by the stamper.

The stamper used here is a silicon master or a nickel electroformed master. The injected resin is a commonly used thermoplastic resin, specifically polypropylene, polyethylene, polystyrene, acrylonitrile-styrene copolymer, or high-fluidity polycarbonate.

In order to transfer the fine processing of the stamper to the deepest portion, a resin having good flow characteristics is generally used, and the temperature and pressure at the time of injection are set to be very high.

However, in the case of the products which have been transferred by injection molding, the limit of the unevenness of the shape is 0.2 to 0.3 mm, and the injection pressure is 200 to 250MPa when MI20(g/10 min) is used.

According to the utility model laid-open publication No. 53-35584, a thin tube having an inner diameter of 0.60 to 2.00mm is known, and can be molded to 0.20mm at present.

Although the patent publication Hei 1-143647 discloses a micropipette, it is made of glass and inherently has the above-mentioned technical problems.

Patent document 1: utility model laid-open publication No. 53-35584

Patent document 2: japanese laid-open patent publication No. Hei 1-143647

Disclosure of Invention

The injection molding method is characterized in that a product having stable quality can be provided at low cost, but is limited by the resin used, because it involves the use of a mold, the releasability and flow characteristics of the resin used, and the like.

Further, since the expensive silicon die is easily broken, if injection molding can be performed at a low injection pressure, the silicon die can be prevented from being broken, and thus the advantage of good mass productivity of the injection molding method can be exerted.

On the other hand, although there is no risk of damage to the nickel electroformed master, the manufacturing process is complicated, requires a long time, and has a very high manufacturing cost, which causes an increase in the unit price of the molded product.

The present invention provides a resin composition which can be molded at a temperature and a pressure lower than those of ordinary injection molding, can precisely transfer a fine processing (a fine uneven pattern shape) of a stamper, and can be injection molded into a micro-component having a micro-hole such as a resin pipette tip capable of collecting or dispensing a fine substance or a micro volume.

The resin composition of the present invention is characterized by comprising a polypropylene resin and a hydrogenated derivative of a block polymer represented by the general formula X-Y, and is excellent in transfer performance.

Wherein, X: is a polymer block immiscible with a polypropylene-based resin, Y: is a conjugated diene elastomeric polymer block.

Here, the term "excellent transferability" means that a fine-machined concave-convex shape of a stamper can be accurately transferred at the time of injection molding in a plate with a micro hole array or the like, and that a concave-convex shape of a stamper or a mold shape can be accurately transferred in a micro hole member such as a pipette tip.

Here, the polymer block X is a polymer block immiscible with the polypropylene-based resin, and the polymer block Y is an elastomeric polymer block of a conjugated diene. As the polypropylene resin, a homopolymer or a random polymer containing an α -olefin such as ethylene, butene-1 or hexene-1 can be used.

The polymer block X includes a polymer obtained by polymerizing a vinyl aromatic monomer (e.g., styrene), ethylene, or a methacrylate (e.g., methyl methacrylate).

The hydrogenated derivatives of the block polymer represented by the general formula X-Y include (X-Y) n wherein n is 1 to 5, X-Y-X, Y-X-Y, and the like.

The polymer block X of the hydrogenated derivative includes polystyrenes and polyolefins, and the polystyrenes include polymer blocks each comprising one or 2 or more vinyl aromatic compounds selected from styrene, α -methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2, 4-dimethylstyrene, vinylnaphthalene and vinylanthracene as a unit.

The polyolefin includes a copolymer of ethylene and an alpha-olefin having 3 to 10 carbon atoms.

And non-conjugated dienes can also be coupled polymerized.

The above-mentioned olefins include polypropylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene and the like.

The above-mentioned non-conjugated diene includes, for example, 1, 4-hexadiene, 5-methyl-1, 5-hexadiene, 1, 4-octadiene, cyclohexadiene, cyclooctadiene, cyclopentadiene, 5-ethylidene-2-norbornene, 5-butylidene-2-norbornene, 2-isopropenyl-5-norbornene and the like.

Specific examples of the copolymer include an ethylene-propylene copolymer, an ethylene-1-butene copolymer, an ethylene-1-octene copolymer, an ethylene-propylene-1, 4-hexadiene copolymer, and an ethylene-propylene-5-ethylidene-2-norbornene copolymer.

As the material before hydrogenation of the polymer block Y, there may be mentioned polybutadiene constituted with at least one group selected from 2-butene-1, 4-diyl and vinyl ethylene as a monomer unit or polyisoprene constituted with at least one group selected from 2-methyl-2-butene-1, 4-diyl, isopropenylethylene and 1-methyl-1-vinyl ethylene as a monomer unit.

Further, as the material before hydrogenation of the polymer block Y, there can be also mentioned an isoprene/butadiene copolymer composed of monomers mainly comprising isoprene units and butadiene units, wherein the isoprene units are at least one group selected from the group consisting of 2-methyl-2-butene-1, 4-diyl, isopropylethylene and 1-methyl-1-vinylethylene, and the butadiene units are 2-butene-1, 4-diyl and/or vinylethylene.

The arrangement of the butadiene units and the isoprene units may be any of a random form, a block form, and a tapered block form (テ - パブロツク).

Further, as the polymer block Y before hydrogenation, there can be mentioned a vinyl aromatic compound/butadiene copolymer comprising a vinyl aromatic compound unit and a monomer unit mainly comprising a butadiene unit, wherein the vinyl aromatic compound unit of the copolymer is one monomer unit selected from styrene, α -methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2, 4-dimethylstyrene, vinylnaphthalene and vinylanthracene, and the butadiene unit is 2-butene-1, 4-diyl and/or vinyl ethylene. The arrangement of the vinyl aromatic compound and the butadiene unit may be any of a random form, a block form, and a tapered block form.

The hydrogenated form of polymer block Y as described above may be partial hydrogenation or complete hydrogenation.

In the resin composition according to the present invention, if the polymer block X of the hydrogenated derivative is polystyrene and the substance before hydrogenation of the polymer block Y is 1, 2-bonded, 3, 4-bonded and/or 1, 4-bonded polyisoprene, the raw material can be easily obtained.

Since the styrene component is poor in compatibility with polypropylene resins and, if the ratio is high, it takes time to mix with polypropylene, and therefore, when a hydrogenated derivative having a large amount of styrene component is used, it is preferable to form a master batch and sufficiently mix the master batch in advance.

The starting material is also readily available when the polymer block X of the hydrogenated derivative is polystyrene and the material of the polymer block Y before hydrogenation is 1, 2-bonded and/or 1, 4-bonded polybutadiene.

Here, the following description will be made of the compatibility.

When the polymer block X is not compatible with the polypropylene-based resin, the polymer block X forms domains having a radius of inertia as large as possible, which can be confirmed by observation with a transmission electron microscope or analysis of a scattering pattern of isolated domains by small-angle X-ray scattering measurement.

In this case, it can be confirmed by Differential Scanning Calorimetry (DSC) or dynamic viscoelasticity measurement that the glass transition temperature of the polymer block X is not substantially changed by the mixing of the polypropylene resin.

When the polymer block Y is compatible with the polypropylene-based resin, the glass transition temperature of the polymer block Y and the glass transition temperature of the polypropylene are changed, and a new glass transition temperature appears at a temperature therebetween.

Such a change in glass transition temperature can be confirmed by dynamic viscoelasticity measurement or the like. If any of the polymer blocks of the X-Y block copolymer is not compatible with the polypropylene resin, the X-Y block polymer phase (forming a domain structure composed of the polymer block X phase and the polymer block Y phase) is morphologically separated from the polypropylene resin phase, and when the polymer block Y is compatible with the polypropylene resin, the spacing between domains of the polymer block X increases, and domains of the polymer block X will be uniformly dispersed in the polypropylene resin.

The change in state of the polymer block Y when it is compatible with the polypropylene resin can be confirmed by observing the mutual positions of the domains with a transmission electron microscope or analyzing the distance between the domains by small-angle X-ray scattering.

In the present invention, a nucleating agent for polypropylene-based resins, including a metal salt type (metal phosphate, metal carbonate) in which physical properties and transparency are improved by a nucleating effect and a benzylidene sorbitol type in which transparency is imparted by forming a network, may be further added.

Benzylidene sorbitol types are condensates of benzaldehyde with sorbitol, which contain hydroxyl groups.

Since a random copolymer is generally higher in transparency than a homopolymer, when transparency is required, it is preferable to use a random copolymer to which a benzylidene sorbitol type nucleating agent is added.

Thus, a micro-component having high transparency can be obtained.

The micro-part using the resin composition of the present invention can be precisely transferred to the fine processing of a stamper to have a plurality of recesses and/or projections on the molding surface, the depth of the recesses or the projection length of the projections is 0.3 to 200 μm, and the opening width of the recesses or the projection width or the rounding diameter of the recesses or projections is 0.3 to 100 μm.

Here, the term "circle-to-circle" means a maximum inscribed circle formed by inscribed inner walls of at least 3 points or more in the case of a concave shape, and means a minimum circumscribed circle formed by circumscribed outer walls of at least 3 points or more in the case of a convex shape.

The concave portion may be a micropore, and the convex portion may be a fine needle.

Since the resin composition has good transferability as a stamper, a micro-part formed using a silicon stamper can be molded under the injection conditions of a normal polypropylene resin or less, and the silicon stamper can be used for injection molding for a long period of time without being damaged.

The resin composition of the present invention can be used for a micro-part for medical use, and can be used for precisely transferring and processing a stamper during injection molding so that a molding surface thereof has a plurality of recesses and/or projections, the depth of the recesses or the projection length of the projections is 0.3 to 200 μm, and the opening width of the recesses or the projection width or the rounding diameter of the recesses or the projections is 0.3 to 100 μm.

The silicone molding is less expensive and can be produced in a shorter time than the nickel electroforming molding, and the resin composition of the present invention has good releasability and does not require application of a release agent, so that the release agent does not remain on the surface of the molded product, and is suitable for forming a medical micro-part.

The resin composition of the present invention can also be used for a plate having a fine pattern of a.

The micropore array plate is excellent in biocompatibility when lymphocytes and the like are added to the pores thereof and no release agent remains on the surface.

The micro-device of the present invention can be used, for example, as a plate for detecting the position of a micro-hole by bonding a transparent plate to the back surface thereof with an adhesive.

If the adhesive property of the styrene block contained in the resin composition to an adhesive, particularly a cyanoacrylate-based adhesive, is utilized to adhere the back surface of the plate with a microwell array to the surface of a transparent plate as a plate for detecting the position of microwells, the plate is suitable for an existing optical reading apparatus, and a plate capable of accurately detecting the position of each microwell can be obtained.

The resin composition of the present invention has excellent transferability, can be injection-molded by reducing the injection pressure in a molten state during molding, and can be applied to a resin pipette tip capable of collecting or dispensing any one of a biological substance, an organic substance, and an inorganic substance.

Since the injection pressure can be reduced by using the resin composition having excellent transferability, a pipette tip capable of collecting or dispensing a minute or minute amount of a biological substance, an organic substance, an inorganic substance, or the like can be obtained.

The biological substance refers to cells, proteins, nucleic acids, cell tissues, or cells. Lymphocytes are exemplified as cells, immunoglobulin G is exemplified as proteins, a DNA solution is exemplified as nucleic acids, and Saccharomyces is exemplified as cells.

In addition, glycerol may be used as an organic substance, and various substances such as phosphate buffer may be used as an inorganic substance.

The capacity of the resin pipette tip may be on the order of tens of picoliters to tens of nanoliters, and the inner diameter of the tip opening may be on the order of several micrometers to tens of micrometers.

In this case, the central portion has a nozzle hole, and the tip portion is preferably tapered tubular.

Here, the tubular shape means a hollow portion having a hole shape as a capillary tube, and the outer shape is not limited to a circular tube, and includes tubes having various irregular shapes.

Here, the volume is on the order of tens of picoliters to tens of nanoliters, and means the volume of a portion for sampling or dispensing directly formed near the tip of the pipette tip and having a tapered inner diameter.

Therefore, because of the volume of the tapered portion, the order of tens of picoliters to tens of nanoliters means 10 picoliters or more, or 90 nanoliters or less.

Similarly, the inner diameter of the tip opening is on the order of several micrometers to several tens of micrometers, and the inner diameter of the tip portion of the sharp pipe gradually changes, and is as large as 1 μm or more, 90 μm or less.

The conical shape is not limited to a conical shape, and includes a pyramidal shape having a triangular or polygonal shape.

By tapering the tip, for example, in a microwell array as shown in FIG. 3, adjacent wells are free of interconnections and can be extracted from the target well only.

When the resin pipette tip has a nozzle hole in the center and a tapered tubular tip, if a cavity portion formed by injection molding is formed into a 4-piece mold with the center axis of the tube as a parting line, the accuracy of the tapered portion of the tip (tip portion) of the nozzle in the electric discharge machining of the mold can be easily achieved.

In injection molding of a resin pipette tip, it is preferable to insert a needle-like core into a hole-forming portion and divide the mold. In this case, the 2-division die can be formed at the minimum, but in the 2-division, it is difficult to perform the electric discharge machining with high dimensional accuracy on a fine portion such as a pipette tip portion.

This is because the metal is discharged between the die and the electrode, and thus corner sagging occurs.

Therefore, the electric discharge machining is facilitated by dividing the die into a plurality of parts, but if the number of parts is large, the die closing at the time of molding is difficult, and 4-division is preferable.

Further, by attaching a silicon stamper to a position corresponding to the tip portion of the pipette tip, the accuracy of the stamper can be improved.

The resin composition of the present invention contains a hydrogenated derivative having a predetermined composition in addition to a polypropylene resin, and thus can be used for fine processing of a stamper or fine shape of a transfer mold under conditions equal to or lower than the injection conditions of a normal polypropylene resin, such as a mold temperature of 50 ℃, a resin temperature of 240 ℃, and an injection pressure of 40 to 70 MPa.

Further, the following fine processing is possible by transfer: the molding surface has a plurality of recesses and/or projections, the depth of the recesses or the projection length of the projections is 0.3 to 200 μm, and the opening width of the recesses or the projection width of the projections or the rounding diameter of the recesses or the projections is 0.3 to 100 μm.

When the amount of the hydrogenated derivative added to the polypropylene-based resin is large, the transfer properties of the homopolymer and the random copolymer are not different from each other, but when the amount of the hydrogenated derivative added is small, the transfer properties of the random copolymer are good.

If polystyrene is used as the polymer block X of the hydrogenated derivative and 1, 2-bonded, 3, 4-bonded and/or 1, 4-bonded polyisoprene is used as the pre-hydrogenation material for the polymer block Y, or polystyrene is used as the polymer block X of the hydrogenated derivative and 1, 2-bonded and/or 1, 4-bonded polybutadiene is used as the pre-hydrogenation material for the polymer block Y, they can be easily obtained from the market and inexpensive micro parts can be produced which can be accurately transferred.

The resin pipette tip of the present invention has a tapered tip end portion, and therefore, almost no vibration is observed even when the resin pipette tip is conveyed at high speed, and a stable capillary tube is formed.

In contrast to the glass capillary tube, which is damaged when it touches the cell plate, the pipette tip made of the resin has strength to withstand collision with the capillary tube, and therefore, this is not a problem.

Further, the nozzle made of artificial ruby is too hard, and on the contrary, the possibility of damaging the plate with cells is increased, and the pipette tip made of the present resin does not damage the other side at all even if it collides with the plate.

The resin pipette is easily mass-produced by controlling the shape with high accuracy because it can be injection-molded, and is easily incinerated and dissolved after being sterilized at high pressure and high temperature because it is made of resin.

When dealing with substances in the human body, in order to prevent biohazard (biofouling) and contamination of recovered samples, it is necessary to supply sterilized nozzles in a sterile state, and each sample needs to be replaced, and the present resin-made pipette tip which can be mass-produced at low cost can satisfy these requirements.

In the present invention, by injection molding using a resin composition having excellent transferability, resin pipette tips having a capacity of several tens of picoliters to several tens of nanoliters and an inner diameter of a tip opening of several micrometers to several tens of micrometers can be mass-produced at low cost.

Further, the resin composition of the present invention does not inhibit the crystallization of the polypropylene resin, and is excellent in heat resistance because the mixture of the hydrogenated derivative compatible with the polypropylene resin does not cause a decrease in melting point, and can be sterilized by heating.

Drawings

FIG. 1 is a graph showing the test conditions and results of example 1.

FIG. 2 is a graph showing the experimental conditions and results of example 2.

Fig. 3 is an enlarged photograph showing good transferability.

Fig. 4 is a photograph showing the creation of a discontinuous weld line from hole to hole.

Fig. 5 is a photograph showing the creation of a continuous weld line from hole to hole.

FIG. 6 is a photograph showing an enlarged cross section of a plate of a microwell array.

FIG. 7 is an exploded perspective view showing a plate for detecting the position of a micropore.

FIG. 8 is a graph showing the test conditions and results of example 3.

FIG. 9 is a graph showing the test conditions and results of example 4.

Fig. 10 is a view showing an example of a resin pipette tip of the present invention.

Fig. 11 is a sectional view showing a resin pipette tip.

FIG. 12 is an enlarged sectional view showing the tip portion of the nozzle.

Fig. 13 is a view showing an example of a mold structure for injection molding of a resin pipette tip.

FIG. 14 is a sectional view taken along line A-A showing the built-in submould.

Fig. 15 is a perspective view showing a cavity.

Fig. 16 shows a division structure of the built-in submodel.

Fig. 17 is a view showing an example of an injection molded starting profile.

FIG. 18 shows the results of evaluation of injection molding properties.

Detailed Description

Example 1: mixing oxygen adduct to resin composition whose base resin is homopolymerized PP Biological (elastomeric) Effect

In example 1 of the present invention, in the case of using a homopolymer of polypropylene (hereinafter referred to as "homopolyPP") as a base resin, a hydrogenated derivative was added in different amounts to prepare a resin composition, and a micropore array plate having a thickness of 1mm was molded to evaluate transferability and moldability of each molded article. The mixing ratio of the homopolymerized PP and the hydrogenated derivative of each component is 100: 0, 70: 30, 60: 40 and 50: 50.

As the homo-PP, Mitsui Kogyo ポリプロ grade J-105F (CAS registry No.: 9003-07-0) for injection molding manufactured by Mitsui Sumitomo polyolefin Co., Ltd was used.

The physical properties of the homopolymerized PP are as follows: MFR 8.0g/10min, density 0.91g/cm³Tensile yield strength 410kg/cm, bending modulus 24300kg/cm, Rockwell indentation hardness 116R.

The hydrogenated derivative is A: ハイブラ -7311S, manufactured by Kabushiki Kaisha クラレ, is a hydrogenated polystyrene-vinyl-polyisoprene-polystyrene block copolymer and has a styrene content of 12% by weight.

The stamper attached to the cavity of the injection molding machine was formed by etching the surface of a silicon wafer and had a fine uneven pattern shape in which projections having a diameter of 10 μm and a height of 13 μm were formed at a center-to-center distance of 25 μm.

The homopolypropylene and the hydrogenated derivative were mixed in the above mixing ratio in advance, and the mixture was charged into a hopper of an injection molding machine and molded under conditions of a mold temperature of 50 ℃, a cylinder temperature of 240 ℃ and an injection pressure of 40 MPa.

The test results are shown in FIG. 1.

In FIG. 1 (Table), h-PP indicates that homopolymeric PP was used as the base material. The surface of the molded plate with the micropore array had a pattern of minute irregularities transferred thereto, and the transferability was evaluated by photographing the molding surface (transfer surface) with a digital HD microscope VH-7000 (manufactured by キ - エンス Co., Ltd.) and observing the same according to the following criteria.

O: no weld line (see fig. 3), Δ: there is a weld line, but not connected (see fig. 4), x: with weld lines and connected (see fig. 5).

For reference, FIG. 6 is a photograph showing an enlarged cross section of the micropore part, the diameter being 10 μm and the depth being 13 μm.

Evaluation of moldability: o: good releasability from a silicon stamper, and automatic continuous production, x: the releasability from a silicon stamper is poor, and a part of the resin remains on the stamper, and automatic continuous production is not possible.

As shown in test No. 1, good transferability was not obtained only for the homopolymeric PP.

The molded article obtained by blending a hydrogenated derivative with homopolypropylene had somewhat improved transferability from test No. 2, and had good transferability in test Nos. 3 and 4.

The releasability was good in all test numbers 1 to 4.

Further, the limit of transferability was examined using a molded article having a blend ratio of hydrogenated derivatives of 50%, and the results were:

the recessed part shape was accurate in transfer without corner sagging until the molded product having an inscribed circle diameter of 0.3 μm and a depth of 0.3. mu.m.

On the other hand, the convex portion was transferred to a molded article having a circumscribed circle diameter of 0.3 μm and a depth of 0.3. mu.m, but slight sagging occurred at the edge portion.

Example 2: hybrid hydrogenated derivatives in resin compositions with random PP as base resin Biological (elastomeric) effects.

In example 2 of the present invention, in the case of using a random copolymer of polypropylene (hereinafter referred to as "random PP") as a base resin, a hydrogenated derivative was added in different amounts to prepare a resin composition, and a cell array sheet having a thickness of 1mm was molded to evaluate transferability and moldability of each molded article.

The mixing ratio of the random PP and the hydrogenated derivative of each component is 100: 0-20: 80.

As the random PP, J-3021GR for injection molding, manufactured by gloss petrochemical Co.

The physical properties of the random PP are as follows: MFR33 g/10min, density 0.9g/cm³Tensile modulus of elasticity 1000MPa, bending modulus of elasticity 1000MPa, and Rockwell indentation hardness 76R.

The hydrogenated derivatives are: a: ハイブラ -7311S (hydrogenated polystyrene-vinyl-polyisoprene-polystyrene block copolymer, styrene content 12% by weight) produced by the aforementioned Kabushiki Kaisha クラレ, B: ダイナロン 1321P (hydrogenated polystyrene butadiene, styrene content 10%) manufactured by J SR K.K., C: クラレ, ハイブラ -7125 (hydrogenated polystyrene-vinyl-polyisoprene-polystyrene block copolymer, styrene content: 20%), manufactured by kokai: HG664 (hydrogenated polystyrene-vinyl-polyisoprene-polystyrene having a primary hydroxyl group at the molecular end, styrene content 30%) manufactured by クラレ K.

The stamper set in the cavity of the injection molding machine was formed by etching a silicon wafer having a thickness of 1mm, and two kinds of columnar projections having a diameter of 10 μm and a height of 13 μm (test nos. 5 to 21 were transferred) were formed at a center distance of 25 μm, and columnar projections having a diameter of 10 μm and a height of 13 μm were formed at a center distance of 15 μm (test nos. 22 and 23 were transferred).

Random PP and the hydrogenated derivative were mixed in the above mixing ratio in advance, and the mixture was charged into a hopper of an injection molding machine and molded under conditions of a mold temperature of 50 ℃, a cylinder temperature of 240 ℃ and an injection pressure of 40 MPa.

The test results are shown in FIG. 2.

In the table of FIG. 2, r-PP represents random PP.

The evaluation method was the same as in example 1.

In test Nos. 5 to 16, test No. 5 contained only random PP, and good transferability was not obtained.

In the molded article of test No. 6 in which the hydrogenated derivative was blended in an amount of 5% by weight to the random PP, good transferability was not obtained.

However, as shown in test No. 7, since the molded article obtained by blending 10 wt% of the hydrogenated derivative with random PP, the transferability was improved to some extent, and the transferability was good in test No. 16.

However, the molded article of test No. 14 had poor mold releasability and was difficult to injection mold.

Further, as shown in test Nos. 15 and 16, the transfer property and moldability of the molded article obtained by blending 40% by weight of the hydrogenated derivative B, C were good.

The molded articles to which the hydrogenated derivatives D of test Nos. 17 to 21 were added exhibited some improvement in transferability since the molded article (test No. 20) to which 30 wt% of the hydrogenated derivative was added to random PP, and transferability was good in test No. 21.

The molded articles of test Nos. 17 to 19 were poor in mold release properties and difficult to injection mold.

However, the molded articles of test Nos. 20 to 21 had good releasability.

Test Nos. 22 and 23 are molded articles having a center distance of 15 μm, and the transferability of the molded article without the hydrogenated derivative A was poor, but the transferability and moldability of the molded article with 50 wt% hydrogenated derivative A were good.

Example 3: nucleating agent mixed in composition with crystallized homopolymerized PP as main component The effect of (1).

In example 3 of the present invention, in the case of using a highly crystalline polypropylene homopolymer as a main component, a nucleating agent was added in different mixing amounts to constitute a resin composition, the composition was kneaded into pellets, microcellular array plate injection-molded articles having a wall thickness of 1mm were produced from the pellet composition, and haze values as transparency evaluations of the respective molded articles were measured.

The amounts of the respective components were fixed to 50 parts by weight and 0.3 part by weight, respectively, based on 100 parts by weight of the homopolypropylene, and the hydrogenated derivative and the metal soap were mixed in a span range of 0 to 1.0 part by weight of the nucleating agent.

In this example, a Mitsui Sumitomo ポリプロ PP grade J-105F (CAS registry No.: 9003-07-0) for injection molding was used as the homo-PP.

The physical properties of the homopolymerized PP are as follows: MFR 8.0g/10min, density 0.91g/cm³Tensile yield strength 410kg/cm²Bending modulus of elasticity 24300kg/cm²Rockwell indentation hardness 116R.

Further, the nucleating agent used in this example was 7B5697N master batch (master batch using 90% by weight of the main component J-105F and 10% by weight of ミラ - ド 3988 manufactured by ミリケナンドカンパニ Co., Ltd.) made of D-sorbitol. The metal soap used was MC-2 produced by Nippon fat Co., Ltd, and was composed of calcium stearate.

The hydrogenated derivative used in this example was ハイブラ -7311S, manufactured by クラレ K., a hydrogenated polystyrene-vinyl-polyisoprene-polystyrene block copolymer having a styrene content of 12% by weight.

First, each composition was melt-kneaded by a 16mm tile-type biaxial extruder (made by Hei side) at a propeller rotation speed of 250rpm and a barrel temperature of 200 ℃ to prepare a pellet composition of a mixture.

The pellet composition was molded into a plate shape by an injection molding machine (product of Kakkaido Kogyo K.K., KM180) under a cylinder temperature of 220 ℃.

In this case, a molded article having a thickness of 1.0mm was obtained.

As each evaluation method, first, the haze value of each plate-shaped injection-molded article was measured at a measurement temperature of 20 ℃ by using a haze value direct-reading computer (manufactured by スガ testing machine Co., Ltd.).

The results are shown in the graph of fig. 8.

As shown in the results of FIG. 8, when the blending amount of the nucleating agent is 0.6 parts by weight based on 100 parts by weight of the homopolypropylene, the haze value of the molded article having a wall thickness of 1.0mm is slightly decreased, but when the blending amount exceeds 0.6 parts by weight, the haze value is increased.

Therefore, in order not to impair the effect of improving the transparency of PP moldings mainly by blending the hydrogenated derivative, it is preferable to blend the nucleating agent in an amount of 0.6 parts by weight or less based on 100 parts by weight of the main component homopolyPP.

Example 4: resin group containing random PP as main componentMixed in the composition as nucleating agent The effect of (1).

In example 4 of the present invention, in the case where a polypropylene random copolymer was used as a main component, a resin composition to which a nucleating agent was added only in the blending amount was kneaded and pelletized, a cell array sheet having a wall thickness of 1.0mm and comprising the pelletized composition was prepared, and the haze value for evaluating the transparency of each molded article was measured.

The amounts of the respective components were fixed to 50 parts by weight and 0.3 part by weight, respectively, relative to 100 parts by weight of the random PP, and the nucleating agent was mixed in a span range of 0 to 0.6 part by weight.

In this example, J-3021GR manufactured by gloss petrochemical Co., Ltd was used as the random copolymer.

The physical properties of the random PP are as follows: MFR33 g/10min, density 0.9g/cm³Tensile modulus of elasticity 1000MPa, bending modulus of elasticity 1000MPa, and Rockwell indentation hardness 76R.

The materials used in this example were the same as those used in example 3 except that the main component was random PP. The preparation of the pellet composition and the injection-molded article and the measurement of the haze value were the same as those in example 3. The measurement results of the haze value are shown in fig. 9.

The results of FIG. 9 show that the haze value of the cell array sheet having a wall thickness of 1.0mm also decreased with the mixing of the nucleating agent, and when random PP was used as the main component, it was concluded that the mixing of the nucleating agent had the effect of imparting transparency to the cell array sheet.

However, when the blending amount of the nucleating agent reaches 0.6 parts by weight with respect to 100 parts by weight of the random PP as the main component, the haze value starts to increase in each molded article, and therefore, when the resin composition is constituted with the random PP as the main component, the upper limit of the blending amount of the nucleating agent is required to be 0.6 parts by weight.

Example 5: micropore position detecting plate

Example 5 is an example of a plate for detecting the position of a micropore, and is constituted by bonding the back surface of a micropore array plate 1 having a hole area of 13.93X 4.63mm at the center thereof, which is 20.32mm X1 mm thick, to the surface of a glass plate 2 of 75mm X25 mm X1 mm with cyanoacrylate.

The cell array plate 1 shown in FIG. 7 is a plate of test No. 23, in which 50 wt% of a hydrogenated derivative was added to random PP.

The fine uneven pattern shape of the hole region (shape in which holes and partition walls between the holes are arranged in a vertically and horizontally regular pattern) was made by arranging 30 holes having a diameter of 10 μm at a center-to-center distance of 15 μm in a vertical direction of the hole region and 10 holes in a horizontal direction, and the total number of the holes was about 25 ten thousand.

The ordinary polypropylene injection-molded article was not bonded by an adhesive other than cyanoacrylate, and the sheet of test No. 23 contained a hydrogenated derivative (particularly polystyrene) and was bonded to a glass sheet by the adhesive.

Cells such as lymphocytes or biological tissues are injected into the wells of the microwell array plate, and the biological reaction expression factors are read by moving the optical reader in the direction indicated by the arrow in the figure.

Example 6: resin pipette tip

The resin pipette tip 10 shown in fig. 10 is not shown, but is attached to a capillary holder for collecting or dispensing biological substances, organic substances, or inorganic substances.

The tip of a body part 11 attached to a holder of a resin pipette tip is formed into an inverted conical part 12.

The main body is formed in a duct shape and has a hole 14 communicating with the tip nozzle opening 13.

The sectional view is shown in FIG. 11, and the enlarged view of the tip portion is shown in FIG. 12.

A conical portion 12 is formed at the tip of the pipette tip so as to surround a fine hole 14 a.

The fine hole 14a is tapered toward the distal end opening, and the diameter D2 of the distal end opening is selected to match the size of the object.

The embodiments shown in fig. 10 to 12 are examples of a lymph node, in which the outer diameter of the main body 11 is 3mm, the total length L1 is about 15mm, the length L2 of the conical portion 12 is about 3mm, the diameter D1 of the hole 14 is 1mm, D2 is on the order of 10 to 15 μm, and D3 is 30 to 35 μm.

The portion used for direct sampling or dispensing in the present invention is the fine hole 14a of the conical portion, and the volume thereof is the volume of the pipette tip.

The capacity may be set to a range of several tens of pico liters to several tens of nanoliters, and in the present embodiment, the capacity is 10 nanoliters.

Next, an example of injection molding will be explained.

Fig. 13 shows an example of the mold structure, and the hatched portion is a portion filled with resin.

The runner portion 22 and the gate portion 23 are formed against the original shape material 20.

A built-in sub-mold 32 having the shape of the starting material 20 of the resin pipette tip 10 as a cavity is mounted in a cavity mold 31.

The built-in sub-mold 32 is shown in fig. 14 in a sectional view taken along line a-a, fig. 15 in a perspective view, and fig. 16 in an exploded view, and is formed into a 4-division type having 32a, 32b, 32c, and 32 d. In fig. 15, a dividing line is denoted by s.

When the 4-division type is formed, the shape of the portion corresponding to the conical portion 12, particularly the shape of the nozzle opening side wall 13a, can be processed with high accuracy in the case of the shape of the spark-machining cavity portion 34.

As shown in fig. 13, a core pin 42 forming the fine hole 14a is provided on the movable die 41 side so as to be able to enter and exit.

In addition, illustration of a press bar for discharging a product and the like is omitted.

With such a die, a starting profile 20 as shown by way of example in fig. 17 is obtained.

The flange 21 is formed in the original material, the formability of the pipette 10 can be ensured, and the flange 21 is cut out from the original material to obtain a product.

As the polypropylene resin, homopolypropylene (homopolypropylene: J-105F manufactured by Mitsui Sumitomo polyolefin resin Co., Ltd. in the table of FIG. 18) and atactic PP (atactic polymer: J-3021GR for injection molding manufactured by Mitsui petrochemical Co., Ltd. in the table of FIG. 18, MFR33 g/10min, density 0.9g/cm³A pipette tip having a flange of the specification shown in FIGS. 10 to 12 was continuously injection-molded at an injection pressure of 15 MPa as an example, by changing the mixing ratio of two types of the tensile modulus of elasticity 1000MPa, the bending modulus of elasticity 1000MPa and the Rockwell indentation hardness 76R) and a hydrogenated derivative (ハイブラ -7311S, manufactured by クラレ K., hydrogenated polystyrene-vinyl-polyisoprene-polystyrene block copolymer, styrene content 12 wt%).

Wherein the injection pressure is a pressure value of the molten resin at the time of injection measured by a pressure gauge. It has been necessary to achieve 200MPa or more in the past, and in this test, it has been confirmed that the injection pressure may be at a level of 20 to 30MPa or less.

In the table, in the evaluation of injection molding, "verygood": a grade indicating excellent transferability and moldability (releasability), "°: a rating indicating that the mold transferability was good and the product had no problem at all, ". DELTA": the product shape produced a level of partial transfer failure, "×": a problematic grade for use as a product.

Therefore, the mixing ratio of the hydrogenated derivative must be 5% or more, but if it exceeds 70%, the shape stability is lowered.

Industrial application prospect

The resin composition of the present invention contains a hydrogenated derivative having a certain composition in addition to a polypropylene resin, and therefore, can be used for a micro-fabrication of a stamper or a precise transfer of a stamper shape under conditions equivalent to or less than those of a general polypropylene resin, and therefore, can be applied to a micro-mechanical switching element; functional elements of micro-optics, micro-fluids, micro-chemical reaction devices, and the like; a capillary die of a blood fluidity measuring device; a micro bioreactor; a plate with a micropore array; a micro-injector; a micro resin pipette tip; micro-scale components in other chemical, biochemical, bioengineering, biological fields.

Claims (8)

1. A micro component, characterized by: the resin composition for a micro-part is obtained by precisely transferring fine processing of a stamper at the time of injection molding so that a molding surface of the micro-part has a plurality of recesses and/or projections, the depth of the recesses or the length of projection of the projections is 0.3 to 200 [ mu ] m, the width of the opening of the recesses or the width of projection of the projections or the diameter of the contact circle of the recesses or the projections is 0.3 to 100 [ mu ] m, and the resin composition comprises a polypropylene resin and a hydrogenated derivative of a block copolymer represented by the general formula X-Y, wherein X: is a polymer block immiscible with a polypropylene-based resin, Y: is a conjugated diene elastomeric polymer block.

2. The micro-component of claim 1, wherein: a hydrogenated derivative constituting a resin composition, wherein a polymer block X is polystyrene and a pre-hydrogenated substance of a polymer block Y is at least one substance selected from the group consisting of 1, 2-bonded polyisoprene, 3, 4-bonded polyisoprene and 1, 4-bonded polyisoprene.

3. The micro-component of claim 1, wherein: a hydrogenated derivative constituting the resin composition, wherein the polymer block X is polystyrene and the prehydrogenated substance of the polymer block Y is at least one selected from the group consisting of 1, 2-bonded polybutadiene and 1, 4-bonded polybutadiene.

4. The micro-member according to any one of claims 1 to 3, wherein a nucleating agent for a polypropylene resin is added to the resin composition.

5. The micro-device of claim 1, wherein the stamper is a silicon stamper.

6. A micropore array plate, which is made of a resin composition, wherein a fine processing of a silicon stamper is precisely transferred at the time of injection molding, and a molding surface thereof has a plurality of concave portions and/or convex portions, wherein the depth of the concave portions or the length of the convex portions protruding therefrom is 0.3 to 200 μm, the width of the opening of the concave portions or the width of the convex portions protruding therefrom or the diameter of the rounding of the concave portions or the convex portions is 0.3 to 100 μm, and wherein the resin composition comprises a polypropylene resin and a hydrogenated derivative of a block copolymer represented by the general formula X-Y, wherein X: is a polymer block immiscible with a polypropylene-based resin, Y: is a conjugated diene elastomeric polymer block.

7. The microwell array plate of claim 6, wherein: a hydrogenated derivative constituting a resin composition, wherein a polymer block X is polystyrene and a pre-hydrogenated substance of a polymer block Y is at least one substance selected from the group consisting of 1, 2-bonded polyisoprene, 3, 4-bonded polyisoprene and 1, 4-bonded polyisoprene.

8. The microwell array plate of claim 6, wherein: a hydrogenated derivative constituting the resin composition, wherein the polymer block X is polystyrene and the prehydrogenated substance of the polymer block Y is at least one selected from the group consisting of 1, 2-bonded polybutadiene and 1, 4-bonded polybutadiene.