JP2022019005A - Medical molding - Google Patents

Abstract

To provide a thermoplastic resin composition and a molding which are excellent in transparency, flexibility and low temperature heat sealability.SOLUTION: A thermoplastic resin composition contains cyclic polyolefin (B) and a styrenic elastomer (B), in which the cyclic polyolefin (B) is composed of a hydrogenated block copolymer that is a hydrogenated body of a block copolymer including at least one aromatic vinyl monomer unit and at least one conjugated diene monomer unit, the hydrogenated block copolymer has a hydrogenated aromatic vinyl polymer block unit that is a hydrogenated body of a polymer block composed of an aromatic vinyl monomer unit, and a hydrogenated conjugated diene polymer block unit that is a hydrogenated body of a polymer block composed of a conjugated diene monomer unit, and the hydrogenated block copolymer has at least two hydrogenated aromatic vinyl polymer block units, and has at least one hydrogenated conjugated diene polymer block unit.SELECTED DRAWING: None

Description

An object of the present invention is to provide a medical molded article having excellent transparency, toughness and heat resistance.

Since the hydrogenated aromatic vinyl polymer has excellent transparency and heat resistance, it is expected to be applied as a medical material.
For example, Patent Document 1 proposes to use a resin composition in which a hydrogenated aromatic vinyl polymer is mixed with a hydride of an aromatic vinyl / conjugated diene block copolymer for an optical disk application.

Japanese Unexamined Patent Publication No. 4-288360

However, in the study of a medical molded body of a hydrogenated aromatic vinyl polymer by the present inventor, the hydrogenated aromatic vinyl polymer proposed in Patent Document 1 is inferior in toughness, so that it can be used as a medical molded body. Turned out to be difficult to apply.
Medical moldings include plastic slide glass, eye drops, drug storage containers such as drug bottle ampoules and vials, sampling containers such as test tubes, blood collection tubes and sample containers, and syringes such as prefilled syringes and syringe syringes. And so on. In order to apply it to these medical molded products, it has been found that it is necessary to improve toughness while maintaining heat resistance and transparency.
The present invention has been made in view of such problems. That is, an object of the present invention is to provide a medical molded body having excellent transparency, toughness, and heat resistance.

As a result of diligent studies, the present inventor has found that a medical molded body having excellent transparency, toughness and heat resistance can be obtained by using a hydrogenated aromatic vinyl polymer and a specific cyclic polyolefin, leading to the present invention. rice field.
That is, the present invention has the following features.

[1] A medical molded body comprising a thermoplastic resin composition containing a hydride aromatic vinyl polymer (A) and a cyclic polyolefin (B), wherein the cyclic polyolefin (B) is at least one kind. The hydride block copolymer is a hydride of the block copolymer containing the aromatic vinyl monomer unit and at least one conjugated diene monomer unit, and the hydride block copolymer is a polymer block composed of the aromatic vinyl monomer unit. It has a hydride aromatic vinyl polymer block unit which is a hydride and a hydride conjugated diene polymer block unit which is a hydride of the polymer block composed of the conjugated diene monomer unit, and the hydride block copolymer is said. A medical molded body having at least two hydrided aromatic vinyl polymer block units and at least one hydride conjugated diene polymer block unit.

[2] The medical molded product according to [1], wherein the hydrogenated aromatic vinyl polymer (A) is polystyrene hydride.
[3] The medical molded product according to [1] or [2], wherein the hydrogenated aromatic vinyl polymer (A) has a hydrogenation level of 90% or more.
[4] The content of the hydrogenated aromatic vinyl polymer block unit in the cyclic polyolefin (B) is 30 to 80 mol%, and the content of the hydrogenated conjugated diene polymer block unit is 20 to 70 mol%. The medical polymer according to any one of [1] to [3].
[5] The hydrogenated aromatic vinyl polymer block unit has a hydrogenation level of 90% or more, and the hydrogenation-conjugated diene polymer block unit has a hydrogenation level of 95% or more [1] to [4]. ] The medical molded body according to any one of the items.

[6] Any of [1] to [5], wherein the hydrogenated aromatic vinyl polymer block unit is a unit made of hydride polystyrene, and the hydrogenated conjugated diene polymer block unit is a unit made of hydrogenated polybutadiene. The medical molded body according to paragraph 1.
[7] The item according to any one of [1] to [6], which contains 10 to 300 parts by mass of the cyclic polyolefin (B) with respect to 100 parts by mass of the hydrogenated aromatic vinyl polymer (A). Medical molded body.
[8] Any one of [1] to [7], which is a molded product selected from a plastic slide glass, an eye drop container, a medicine bottle ampoule, a vial, a test tube, a blood collection tube, a sample container, a prefilled syringe, and a syringe syringe. The medical molded body described in.

The medical molded product made of the thermoplastic resin composition containing the hydrogenated aromatic vinyl polymer and the specific cyclic polyolefin according to the present invention is excellent in transparency, toughness and heat resistance, and is suitable as a medical molded product. ..

The present invention will be described in detail below, but the following description is an example of an embodiment of the present invention, and the present invention is not limited to the following description as long as the gist of the present invention is not exceeded. It can be arbitrarily modified and carried out without departing from the gist of the invention.
In the following, when a numerical value or a physical property value is inserted before and after using "-", it is used as including the values before and after that.

The invention according to the present application is an invention for a medical molded body composed of a thermoplastic resin composition containing a hydrogenated aromatic vinyl polymer (A) and a specific cyclic polyolefin (B).

<Hydrogenated aromatic vinyl polymer (A)>
The hydrogenated aromatic vinyl polymer (A) of the present invention is a hydrogenated product of the aromatic vinyl polymer.
The hydrogenated aromatic vinyl polymer of the present invention is produced by hydrogenation of an aromatic vinyl polymer such as polystyrene, styrene / α-methylstyrene copolymer, and styrene / vinylnaphthalene copolymer. Among these, hydrided polystyrene, which is a hydride of polystyrene, is preferable.

The aromatic vinyl monomer used as a raw material for the aromatic vinyl polymer is a monomer represented by the general formula (1).

In the general formula (1), R is a hydrogen or an alkyl group.
The alkyl group may be a mono- or multiple-substituted alkyl group with a functional group such as a halo group, a nitro group, an amino group, a hydroxy group, a cyano group, a carbonyl group, and a carboxyl group. Further, the number of carbon atoms of the alkyl group is preferably 1 to 6.
Of these, hydrogen is preferable for R.

In the general formula (1), Ar is a phenyl group, a halophenyl group, an alkylphenyl group, an alkylhalophenyl group, a naphthyl group, a pyridinyl group, or an anthrasenyl group.
Of these, Ar is preferably a phenyl group or an alkylphenyl group, more preferably a phenyl group.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, vinyltoluene (including all isomers, particularly p-vinyltoluene), ethylstyrene, propylstyrene, butylstyrene, vinylbiphenyl, vinylnaphthalene, and vinyl. Anthracene (all isomers) and mixtures thereof are mentioned, with styrene being preferred.

The lower limit of the weight average molecular weight (Mw) of the hydrogenated aromatic vinyl polymer (A) is preferably 100,000 or more. The upper limit of Mw is preferably 400,000 or less, more preferably 300,000 or less, still more preferably 200,000 or less.
If Mw is at least the above lower limit value, the mechanical strength does not decrease, and if it is at least the above upper limit value, the molding processability does not deteriorate.

Here, Mw of the hydrogenated aromatic vinyl polymer (A) is a polystyrene-equivalent value measured under the following conditions using gel permeation chromatography (GPC).
・ Equipment: "GPC HLC-832GPC / HT" manufactured by Tosoh Corporation
-Column: 3 "AD806M / S" manufactured by Showa Denko Corporation (calibration of the column is 0 for each of monodisperse polystyrene (A500, A2500, F1, F2, F4, F10, F20, F40, F288) manufactured by Tosoh Corporation. .5 mg / mL solution) was measured, and the logarithmic value of elution volume and molecular weight was approximated by a cubic equation.)
-Detector: "1A infrared spectrophotometer" manufactured by MIRAN (measurement wavelength, 3.42 μm)
-Solvent: o-dichlorobenzene-Temperature: 135 ° C
・ Flow rate: 1.0 mL / min ・ Injection amount: 200 μL
-Concentration: 20 mg / 10 mL

The hydrogenation level of the hydrogenated aromatic vinyl polymer (A) is preferably 90% or more, more preferably 95% or more, still more preferably 97% or more.
The hydrogenation level of the hydrogenated aromatic vinyl polymer indicates the rate at which the aromatic vinyl polymer is saturated by hydrogenation. Such high levels of hydrogenation are preferred for heat resistance and transparency.
The hydrogenation level of the hydrogenated aromatic vinyl polymer (A) is determined by using proton NMR.

The melt flow rate (MFR) of the hydrogenated aromatic vinyl polymer (A) of the present invention is preferably 0.1 g / 10 minutes or more, preferably 0.2 g / 10 minutes or more from the viewpoint of the molding method and the appearance of the molded body. More preferred. Further, from the viewpoint of material strength, 200 g / 10 minutes or less is preferable, 100 g / 10 minutes or less is more preferable, and 50 g / 10 minutes or less is further preferable.
The MFR was measured according to ISO R1133 under the conditions of a measurement temperature of 230 ° C. and a measurement load of 2.16 kg.

As the hydrogenated aromatic vinyl polymer (A), one type may be used alone, or two or more types having different composition and physical properties of each monomer unit may be used in combination.

<Cyclic polyolefin (B)>
The cyclic polyolefin (B) of the present invention comprises a hydrogenated aromatic vinyl polymer block unit which is a hydride of a polymer block composed of at least one aromatic vinyl monomer unit, and a conjugated diene monomer unit of at least one kind. It is a hydrogenation block copolymer having a hydrogenation-conjugated diene polymer block unit which is a hydride of a polymer block.
The hydrogenated block copolymer has at least two hydrogenated aromatic vinyl polymer block units and at least one hydrogenated conjugated diene polymer block unit.

The term "block" refers to a polymerized segment of a copolymer that represents microlayer separation from structurally or structurally different polymerized segments of the copolymer. For this reason, for example, "having at least two block units" means that the hydrogenated block copolymer has at least two polymerized segments of the copolymer representing microlayer separation from structurally or structurally different polymerized segments. That means.

The aromatic vinyl monomer used as a raw material for the aromatic vinyl monomer unit is the monomer represented by the general formula (1).

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, vinyltoluene (including all isomers, particularly p-vinyltoluene), ethylstyrene, propylstyrene, butylstyrene, vinylbiphenyl, vinylnaphthalene, and vinyl. Anthracene (all isomers) and mixtures thereof are mentioned, with styrene being preferred.

The conjugated diene monomer used as a raw material for the conjugated diene monomer unit may be a monomer having two conjugated double bonds.
Examples of the conjugated diene monomer include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2-methyl-1,3 pentadiene and similar compounds thereof, and mixtures thereof, and butadiene is used. preferable.

Polybutadiene, which is a polymer of 1,3-butadiene, has either a 1,2 configuration that gives an equivalent of 1-butene repeating units by hydrogenation, or a 1,4 configuration that gives an equivalent of ethylene repeating units by hydrogenation. Can be included.

A preferred example of the hydrogenated aromatic vinyl polymer block unit is a unit made of hydrogenated polystyrene, and a preferred example of the hydrogenated conjugated dienepolymer block unit is a unit made of hydrogenated polybutadiene. ..
A preferred embodiment of the hydrogenated block copolymer is a hydrogenated triblock or pentablock copolymer of styrene and butadiene, preferably free of any other functional group or structural modifier.

The content of the hydrogenated aromatic vinyl polymer block unit is 30 to 80 mol%, preferably 40 to 75 mol% with respect to the cyclic polyolefin (B).
If the ratio of the hydrogenated aromatic vinyl polymer block unit is not less than the above lower limit value, the rigidity does not decrease, and if it is not more than the above upper limit value, the toughness is improved and the brittleness is not deteriorated.

The content of the hydrogenated conjugated diene polymer block unit is 20 to 70 mol%, preferably 25 to 60 mol% with respect to the cyclic polyolefin (B).
When the ratio of the hydrogenated conjugated diene polymer block unit is not less than the above lower limit value, the toughness is improved and the brittleness is not deteriorated, and when it is not more than the above upper limit value, the rigidity is not lowered.

In the present invention, the "cyclic" of the cyclic polyolefin means an alicyclic structure formed by hydrogenation of an aromatic ring possessed by the hydrogenated aromatic vinyl polymer block unit.

Hydrogenated block copolymers include triblocks, multiblocks, taper blocks, and SISBS such as SBS, SBSBS, SIS, SIS, and SISBS (where S stands for polystyrene, B stands for polybutadiene, and I stands for polyisoprene). Manufactured by hydrogenation of block copolymers, including star block copolymers.

Hydrogenated block copolymers contain a segment consisting of an aromatic vinyl polymer at each end. This will result in the hydrogenated block copolymer having at least two hydrogenated aromatic vinyl polymer block units. Then, there will be at least one hydrogenated conjugated diene polymer block unit between the two hydrogenated aromatic vinyl polymer block units.

The pre-hydrogenation block copolymer constituting the hydrogenation block may contain several additional blocks, and these blocks may be attached to any position in the triblock polymer backbone. Thus, the linear block includes, for example, SBS, SBSB, SBBSBS, and SBBSSB. The copolymer may be branched and the polymerization chain may be attached at any position along the backbone of the copolymer.

The lower limit of Mw of the hydrogenated block copolymer is preferably 30,000 or more, more preferably 40,000 or more, still more preferably 45,000 or more, and particularly preferably 50,000 or more. The upper limit of Mw is preferably 120,000 or less, more preferably 100,000 or less, still more preferably 95,000 or less, particularly preferably 90,000 or less, most preferably 85,000 or less, and extremely preferably 80. It is 000 or less.
If Mw is at least the above lower limit value, the mechanical strength does not decrease, and if it is at least the above upper limit value, the molding processability does not deteriorate.
Here, the Mw of the cyclic polyolefin (B) is determined using GPC under the same measurement conditions as that of the hydrogenated aromatic vinyl polymer (A).

The hydrogenation level of the hydride block copolymer is preferably 90% or more for the hydride aromatic vinyl polymer block unit, 95% or more for the hydride conjugated diene polymer block unit; more preferably 95% for the hydride aromatic vinyl polymer block unit. % Or more, hydrogenated conjugated dienepolymer block unit is 99% or more; more preferably hydrogenated aromatic vinyl polymer block unit is 98% or more, hydrogenated conjugated dienepolymer block unit is 99.5% or more; particularly preferably hydrogenation The aromatic vinyl polymer block unit is 99.5% or more, and the hydrogenated conjugated diene polymer block unit is 99.5% or more.
The hydrogenation level of the hydrogenated aromatic vinyl polymer block unit indicates the ratio at which the aromatic vinyl polymer block unit is saturated by hydrogenation, and the hydrogenation level of the hydrogenation conjugated diene polymer block unit is the conjugated diene. Shows the rate at which a polymer block unit is saturated by hydrogenation. Such high levels of hydrogenation are preferred for heat resistance and transparency.
The hydrogenation level of the cyclic polyolefin (B) is determined using proton NMR.

The MFR of the cyclic polyolefin (B) of the present invention is preferably 0.1 g / 10 minutes or more, and more preferably 0.2 g / 10 minutes or more from the viewpoint of the molding method and the appearance of the molded product. Further, from the viewpoint of material strength, 200 g / 10 minutes or less is preferable, 100 g / 10 minutes or less is more preferable, and 50 g / 10 minutes or less is further preferable.
The MFR was measured according to ISO R1133 under the conditions of a measurement temperature of 230 ° C. and a measurement load of 2.16 kg.

As the cyclic polyolefin (B), one type may be used alone, or two or more types having different composition and physical properties of each monomer unit may be used in combination.
As the cyclic polyolefin (B) of the present invention, a commercially available product can be used, and specific examples thereof include Mitsubishi Chemical Corporation: Zelas (registered trademark).

<Thermoplastic resin composition>
The medical molded product of the present invention is made of a thermoplastic resin containing the hydrogenated aromatic vinyl polymer (A) and the cyclic polyolefin (B).
The thermoplastic resin composition preferably contains 10 to 300 parts by mass of the cyclic polyolefin (B) with respect to 100 parts by mass of the hydrogenated aromatic vinyl polymer (A).

The content of the cyclic polyolefin (B) is more preferably 15 parts by mass or more, still more preferably 20 parts by mass or more, based on 100 parts by mass of the hydrogenated aromatic vinyl polymer (A). Further, 250 parts by mass or less is more preferable, and 200 parts by mass or less is further preferable.
When the content of the cyclic polyolefin (B) is within the above range, the transparency, toughness and heat resistance are good.

The haze of the thermoplastic resin composition is an index of transparency, preferably 30% or less, more preferably 20% or less, still more preferably 10% or less. The smaller the value, the better the transparency.
The flexural modulus of the thermoplastic resin composition is preferably 100 to 3000 MPa, more preferably 200 to 2800 MPa, and even more preferably 300 to 2500 MPa.
Within the above range, toughness and rigidity required for the molded product can be obtained.

The shrinkage ratio of the thermoplastic resin composition in autoclave sterilization at 121 ° C. for 15 minutes is an index of heat resistance, preferably 2% or less, more preferably 1% or less, still more preferably 0.8% or less. Is. The smaller the value, the better the heat resistance.
Further, cracks in the thermoplastic resin composition in autoclave sterilization at 121 ° C. for 15 minutes are an index of toughness, and it is preferable that cracks do not occur.

<Other ingredients>
The thermoplastic resin composition of the medical molded product of the present invention may contain, as other components, a compounding agent commonly used in the resin composition as long as the effects of the present invention are not impaired.
Examples of such compounding agents include heat stabilizers, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, crystal nucleating agents, rust inhibitors, inorganic fillers, foaming agents and pigments.
Of these, it is preferable to contain an antioxidant, particularly a phenol-based, sulfur-based or phosphorus-based antioxidant. The antioxidant is preferably contained in an amount of 0.01 to 2 parts by mass with respect to 100 parts by mass of the thermoplastic resin composition.

Further, a resin component or an elastomer component other than the hydrogenated aromatic vinyl polymer (A) and the cyclic polyolefin (B) may be contained as long as the effect of the present invention is not impaired.
Examples of such resin components include polyethylene resin, polypropylene resin, ethylene / α-olefin copolymer resin, propylene / α-olefin copolymer resin, ethylene / vinyl acetate copolymer resin, and ethylene / acrylic acid ester copolymer resin. , Ethylene / (meth) acrylic acid copolymer resin, polystyrene resin, polyvinyl chloride resin, polyester resin, polyamide resin, ethylene / vinyl alcohol copolymer, acrylic resin, petroleum resin and the like.

Examples of the elastomer component include olefin-based elastomers, styrene-based elastomers, polyester-based elastomers, urethane-based elastomers, acrylic-based elastomers, and nylon-based elastomers.

The other components may be added to the component (A) and the component (B) by the kneading method commonly used for melt-kneading the thermoplastic resin, or dissolved in an organic solvent together with the component (A). It may be mixed.
The content of other resin components and elastomer components is preferably 50% by mass or less, more preferably 30% by mass or less of all the components.

<Manufacturing method of thermoplastic resin composition>
The thermoplastic resin composition of the present invention comprises the hydrogenated aromatic vinyl polymer (A), the cyclic polyolefin (B), and, if necessary, the other components described above in a conventional extruder, Banbury mixer, or roll. , Brabender plast graph, kneader brabender, etc. can be kneaded and manufactured by a conventional method.
Among these manufacturing methods, it is preferable to use an extruder, particularly a twin-screw extruder.
When the thermoplastic resin composition of the present invention is kneaded and produced by an extruder or the like, it is usually melt-kneaded in a state of being heated to 220 to 320 ° C., preferably 250 to 300 ° C.

<Medical molded product and its manufacturing method>
By molding the thermoplastic resin composition of the present invention, various medical molded articles can be obtained.
Examples of the molding method include various molding methods such as a normal injection molding method, a gas injection molding method, an injection compression molding method, and a short shot foam molding method.
The thermoplastic resin composition of the present invention is preferably injection-molded into a medical molded body, and the molding conditions for injection molding are as follows.
The molding temperature is 250 to 320 ° C, preferably 270 to 300 ° C.
The injection pressure is 5 to 100 MPa, preferably 10 to 80 MPa.
The mold temperature is 0 to 100 ° C, preferably 30 to 95 ° C. More preferably, it is 70 to 95 ° C.

<Use>
The medical molded body of the present invention is a plastic slide glass; a drug storage container such as an eye drop container, a drug bottle ampoule, and a vial; a sampling container such as a test tube, a blood collection tube, and a sample container; syringes such as a prefilled syringe and a syringe syringe. Can be suitably used for.

Hereinafter, the content of the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded. The values of various production conditions and evaluation results in the following examples have meanings as preferable values of the upper limit or the lower limit in the embodiment of the present invention, and the preferable ranges are the above-mentioned upper limit or lower limit values and the following. It may be in the range specified by the value of Examples or the combination with the values of Examples.
In the following description, "part" means "part by mass".

[Physical characteristics]
<Ratio of polymer blocks of cyclic polyolefin (B)>
[Measurement by carbon NMR]
-Device: Bruker's "AVANCE400 spectrometer"
-Solvent: o-dichlorobenzene-h ₄ / p-dichlorobenzene-d ₄ mixed solvent-Concentration: 0.3 g / 2.5 mL
-Measurement: ¹³ C-NMR
・ Resonance frequency: 400MHz
・ Number of integrations: 1536
・ Flip angle: 45 degrees ・ Data acquisition time: 1.5 seconds ・ Pulse repetition time: 15 seconds ・ Measurement temperature: 100 ° C
・^1H irradiation: Complete decoupling

<Hydrogenation level>
[Measurement by proton NMR]
・ Equipment: "400YH spectrometer" manufactured by JASCO Corporation
-Solvent: Deuterated chloroform-Concentration: 0.045 g / 1.0 mL
・ Measurement: ^{1 1} H-NMR
・ Resonance frequency: 400MHz
・ Number of integrations: 8
-Measurement temperature: 18.5 ° C
-Hydrogenation level of hydrogenated aromatic vinyl polymer (A): Integrated value reduction rate of 6.8 to 7.5 ppm-Hydrogenation level of cyclic polyolefin (B) in units of hydrogenated aromatic vinyl polymer block: 6. Integral value reduction rate of 8 to 7.5 ppm ・ Hydrogenation level of hydrogenation-conjugated diene polymer block of cyclic polyolefin (B): Integral value reduction rate of 5.7 to 6.4 ppm

<Melt flow rate (MFR)>
It was measured under the following conditions according to ISO R1133.
・ Equipment: "Melt Indexer" manufactured by Toyo Seiki Seisakusho Co., Ltd.
・ Temperature: 230 ℃
・ Orifice hole diameter: 2 mm
・ Load: 2.16kg

<Haze>
Using a plunger type injection molding machine (injection molding machine attached to the small kneader Xplore MC15 manufactured by Xplore Instruments), the injection pressure is 3.5 bar, the cylinder temperature is 290 ° C, the mold temperature is 90 ° C, and the thickness is 2 mm × the width is 30 mm ×. A test piece having a length of 80 mm was formed, and haze, which is an index of transparency, was measured according to ISO 14782.

<Bending modulus>
Using a plunger type injection molding machine (injection molding machine attached to the small kneader Xplore MC15 manufactured by Xplore Instruments), the injection pressure is 3.5 bar, the cylinder temperature is 290 ° C, the mold temperature is 90 ° C, and the thickness is 4 mm × the width is 10 mm ×. A test piece having a length of 80 mm was molded.
Using this test piece, the flexural modulus, which is an index of rigidity, was measured at a span spacing of 64 mm and a bending speed of 2 mm / min in accordance with ISO178.

<Autoclave sterilization: shrinkage rate, presence or absence of cracks>
Using a plunger type injection molding machine (injection molding machine attached to the Xplore MC15 small kneader manufactured by Xplore Instruments), the injection pressure is 3.5 bar, the cylinder temperature is 290 ° C, the mold temperature is 90 ° C, and the thickness is 2 mm × the width is 30 mm ×. A test piece with a length of 80 mm was molded and autoclaved at 121 ° C for 15 minutes using a high-pressure steam sterilizer (high-pressure steam sterilizer type CLS-32S manufactured by Alp), and the test piece was sterilized in the length direction. The shrinkage rate was measured from the dimensional change. This shrinkage rate is an index of heat resistance.
In addition, the presence or absence of cracks was visually confirmed. The presence or absence of cracks is an indicator of toughness.

[material]
<Hydrogenated aromatic vinyl polymer (A-1)>
Polystyrene (HH-102 manufactured by PS Japan) was dissolved in tetrahydrofuran, 5% Pd / C was added as a catalyst, and a hydrogenation reaction was carried out at a temperature of 170 ° C. and a hydrogen pressure of 100 kg / cm ² for 6 hours. Polystyrene was obtained.
Polystyrene hydride / density (ASTM D792): 0.94 g / cm ³
-MFR (230 ° C, 2.16 kg): 0.3 g / 10 minutes-Hydrogenation level of hydrogenated aromatic vinyl polymer: 99.9% or more-Mw: 160,000

<Cyclic polyolefin (B-1)>
Zelas (trademark registration) MC930 manufactured by Mitsubishi Chemical Corporation
-Density (ASTM D792): 0.94 g / cm ³
-MFR (230 ° C, 2.16 kg): 1 g / 10 minutes-Hydrogenated aromatic vinyl polymer block Unit: Hydrogenated polystyrene with a content of 65 mol% and hydrogenation level of 99.5% or more-Hydrogenated conjugated dienepolymer block Unit: Hydrogenated polybutadiene block structure: pentablock structure, total hydrogenation level: 99.5% or more, Mw: 72,000, content rate 35 mol%, hydrogenation level 99.5% or more

<Cyclic polyolefin (B-2)>
Zelas (trademark registration) MC931 manufactured by Mitsubishi Chemical Corporation
-Density (ASTM D792): 0.94 g / cm ³
-MFR (230 ° C, 2.16 kg): 35 g / 10 minutes-Hydrogenated aromatic vinyl polymer block Unit: Hydrogenated polystyrene with a content of 60 mol% and hydrogenation level of 99.5% or more-Hydrogenated conjugated dienepolymer block Unit: 40 mol% content, hydrogenated polybutadiene block structure: pentablock structure, total hydrogenation level: 99.5% or more, Mw: 51,000

<Cyclic polyolefin (B-3)>
Zelas (trademark registration) MC932 manufactured by Mitsubishi Chemical Corporation
-Density (ASTM D792): 0.94 g / cm ³
-MFR (230 ° C, 2.16 kg): 0.5 g / 10 minutes-Hydrogen aromatic vinyl polymer Block unit: Hydrogenated polystyrene with a content of 50 mol% and hydrogenation level of 98.7% -Hydrogen conjugated diene polymer Block unit: 50 mol% content, hydrogenated polybutadiene block structure with hydrogenation level of 99.5% or more: pentablock structure, total hydrogenation level: 99.2%
・ Mw: 75,000

<Example 1>
100 parts of hydride aromatic vinyl polymer (A-1) and 33 parts of cyclic polyolefin (B-1), 0.05 part of BASF's Irganox 1010 and BASF's Ilgafos 168 0.05 part as antioxidants. In addition, using a plunger type injection molding machine (injection molding machine attached to the small kneader Xplore MC15 manufactured by Xplore Instruments), melt kneading was performed at a temperature of 290 ° C. and a screw rotation speed of 100 rpm for 1 minute, and the injection pressure was 3.5 bar and the cylinder temperature. At 290 ° C. and a mold temperature of 90 ° C., a test piece having a thickness of 2 mm × a width of 30 mm × a length of 80 mm and a test piece having a thickness of 4 mm × a width of 10 mm × a length of 80 mm were molded.
Table 1 shows the evaluation results of various physical properties.

<Examples 2 to 6, Comparative Examples 1 to 4>
The components (A) and (B) were blended as shown in Table 1, and a test piece of the thermoplastic resin composition was molded in the same manner as in Example 1. Table 1 shows the evaluation results of various physical properties.

From Table 1, Examples 1 to 6 corresponding to the present invention have excellent transparency, a small shrinkage rate in autoclave sterilization, excellent heat resistance, and autoclave sterilization without cracks and excellent toughness. I understand.
On the other hand, it was found that in Comparative Example 1 containing no cyclic polyolefin (B), cracks were generated by autoclave sterilization and the toughness was inferior.
It was found that Comparative Examples 2 to 4 containing no hydrogenated aromatic vinyl polymer (A) had large shrinkage in autoclave sterilization and were inferior in heat resistance.

The medical molded body of the present invention is a plastic slide glass; a drug storage container such as an eye drop container, a drug bottle ampoule, and a vial; a sampling container such as a test tube, a blood collection tube, and a sample container; as syringes such as a prefilled syringe and a syringe syringe. Very useful.

Claims (8)

A medical molded product comprising a thermoplastic resin composition containing a hydrogenated aromatic vinyl polymer (A) and a cyclic polyolefin (B).
The cyclic polyolefin (B) comprises a hydrogenated block copolymer, which is a hydride of a block copolymer containing at least one aromatic vinyl monomer unit and at least one conjugated diene monomer unit.
The hydride block copolymer is hydrogen, which is a hydride of a polymer block composed of the aromatic vinyl monomer unit, a hydride aromatic vinyl polymer block unit, and a conjugated diene monomer unit. It has a conjugated diene polymer block unit and has
The hydrogenated block copolymer is a medical molded body having at least two hydrogenated aromatic vinyl polymer block units and at least one hydrogenated conjugated diene polymer block unit. The medical molded product according to claim 1, wherein the hydrogenated aromatic vinyl polymer (A) is polystyrene hydride. The medical molded product according to claim 1 or 2, wherein the hydrogenated aromatic vinyl polymer (A) has a hydrogenation level of 90% or more. The content of the hydrogenated aromatic vinyl polymer block unit in the cyclic polyolefin (B) is 30 to 80 mol%, and the content of the hydrogenated conjugated diene polymer block unit is 20 to 70 mol%. The medical molded product according to any one of claims 1 to 3. Any one of claims 1 to 4, wherein the hydrogenated aromatic vinyl polymer block unit has a hydrogenation level of 90% or more, and the hydrogenation-conjugated diene polymer block unit has a hydrogenation level of 95% or more. The medical molded body described in the section. The unit according to any one of claims 1 to 5, wherein the hydrogenated aromatic vinyl polymer block unit is a unit made of hydride polystyrene, and the hydrogenated conjugated diene polymer block unit is a unit made of hydrogenated polybutadiene. Medical polymer. The medical molded product according to any one of claims 1 to 6, which contains 10 to 300 parts by mass of the cyclic polyolefin (B) with respect to 100 parts by mass of the hydrogenated aromatic vinyl polymer (A). The medical use according to any one of claims 1 to 7, which is a molded product selected from a plastic slide glass, an eye drop container, a drug bottle ampoule, a vial, a test tube, a blood collection tube, a sample container, a prefilled syringe, and a syringe syringe. Molded body.