JP7777421B2 - Medical thermoplastic resin composition - Google Patents

Description

The present invention relates to a medical thermoplastic resin composition.

Polyolefins such as polyethylene and polypropylene have excellent mechanical strength, processability, chemical resistance, and electrical properties, and are also lightweight and inexpensive, so they are widely used in applications such as household and industrial materials.
The properties of polyolefins that are desired to be improved include surface properties such as water repellency, oil repellency, stain resistance, non-adhesion, low adsorption, gas permeability, etc. Improvements in these properties are particularly expected in the fields of consumer goods such as toiletries and food products, and in the field of medical and sanitary materials, which require stain resistance and low adsorption.
When used in the field of medical hygiene materials, among non-adhesive materials, those with low adsorption of pharmaceuticals such as proteins are particularly preferred, but polypropylene materials tend to have high adsorption of pharmaceuticals such as proteins.

It is known that silicone is block copolymerized as a polyolefin material to modify surface properties. An example of such a block copolymer is a polymer of a specific polypropylene and siloxane copolymer, as shown in Patent Document 1.

JP 2019-59810 A

However, Patent Document 1 does not mention the use of the polymer of polypropylene and siloxane copolymer described therein for medical purposes, and does not consider whether it is possible to reduce the adsorption of drugs such as proteins.
SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a resin molded article that, when used for medical purposes, has excellent low adsorption properties, particularly for drugs such as proteins.

The present invention has been made in view of the above problems. That is, an object of the present invention is to provide a medical molded article made of a thermoplastic resin composition having excellent low adsorption properties.
That is, the present invention has the following features.

[1] A medical thermoplastic resin composition containing a block copolymer (A) having a silicone block and a polyolefin block, and a polyolefin resin (B).
[2] The medical thermoplastic resin composition according to [1], wherein the polyolefin resin (B) is a polypropylene resin.
[3] The medical thermoplastic resin composition according to [1] or [2], wherein the block copolymer (A) is a block copolymer having a silicone block and a polypropylene block.
[4] The medical thermoplastic resin composition according to any one of [1] to [3], wherein the block copolymer (A) has the following structural unit (I):

(In formula (I), _R1 and _R2 each independently represent a hydrocarbon group having 1 to 10 carbon atoms.)
[5] The medical thermoplastic resin composition according to [4], wherein R ₁ and R ₂ of the structural unit (I) are methyl groups.
[6] The medical thermoplastic resin composition according to [5], wherein the number of dimethylsilyl groups per 1,000 propylene structures derived from the block copolymer (A) contained in the thermoplastic resin composition is 2.5 to 210.
[7] The medical thermoplastic resin composition according to any one of [5] and [6], wherein the number of dimethylsilyl groups per 1,000 propylene structures of the block copolymer (A) is 50 to 300.
[8] The medical thermoplastic resin composition according to any one of [1] to [7], wherein the content ratio expressed as [mass of block copolymer (A)]/[mass of polyolefin resin (B)] is 5/95 to 70/30.

[9] A molded article made of the medical thermoplastic resin composition according to any one of [1] to [8].
[10] The molded article according to [9], which is one selected from a plastic slide glass, an eye dropper, a medicine bottle ampoule, a vial, a test tube, a blood collection tube, a specimen container, a prefilled syringe, and a syringe.
[11] A medical laminate having a base layer containing a polyolefin resin and a layer made of the medical thermoplastic resin composition according to any one of [1] to [8].
[12] The medical laminate according to [11], wherein the polyolefin resin constituting the base layer is a polypropylene resin.
[13] A medical packaging bag using the medical laminate described in [11] or [12].
[14] An infusion bag using the medical packaging bag described in [13].

The present invention provides a medical molded article made from a thermoplastic resin composition with excellent low adsorption properties. By using a resin composition containing a polyolefin and a silylated polyolefin, a silicone-polyolefin block copolymer with a high surface modification effect, the surface properties of the resin composition can be effectively improved, particularly its low adsorption properties. This allows medical molded articles with excellent low adsorption properties for drugs such as proteins to be produced energy efficiently and with high selectivity for block structure.

The following describes in detail the embodiments of the present invention, but the present invention is not limited to the following description and can be modified as desired without departing from the spirit of the present invention. Furthermore, in this specification, when "~" is used to express a numerical value or physical property value, the values before and after the "~" are included.

The medical thermoplastic resin composition of this invention is a resin composition containing a block copolymer (A) having a silicone block and a polyolefin block, and a polyolefin resin (B).

[Block copolymer (A)]
The block copolymer (A) of the present invention is a block copolymer of a silicone (sometimes referred to as a silicone block) having the structural unit (I) below and a polyolefin, in which R ₁ and R ₂ each independently represent a hydrocarbon group having 1 to 10 carbon atoms. Each of R ₁ to R ₂ is preferably a hydrocarbon group having 1 to 6 carbon atoms, and is particularly preferably a methyl group.

The silicone block may also contain the following structural unit (II): In formula (II), _R3 represents a hydrocarbon group having 1 to 10 carbon atoms. _R3 is preferably a hydrocarbon group having 1 to 6 carbon atoms, and is particularly preferably a methyl group.

The polyolefin block of the block copolymer (A) is preferably a polypropylene block, and the propylene unit content of the polypropylene block is 50% by mass or more. Any of a propylene homopolymer, a propylene random copolymer, and a propylene block copolymer can be used, which contributes to compatibility with polyolefin resins, heat resistance, strength, and moldability.

When the polypropylene block of the block copolymer (A) is a propylene random copolymer, examples of monomers copolymerizable with propylene include ethylene, 1-butene, 2-methylpropylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene.

When the polypropylene block of the block copolymer (A) is a propylene block copolymer, examples of the propylene block copolymer include propylene block copolymers obtained by multi-stage polymerization, more specifically, propylene block copolymers obtained by polymerizing polypropylene in a first stage and polymerizing a propylene-ethylene copolymer in a second stage.
The polypropylene block may contain a segment derived from a comonomer other than propylene in the main chain, as long as the effect of the present invention is not impaired.

The propylene unit content of the polypropylene block of the block copolymer (A) is preferably 60% by mass or more, more preferably 75% by mass or more, and even more preferably 90% by mass or more. When the propylene unit content is equal to or greater than the lower limit, the heat resistance and rigidity are improved. The upper limit of the propylene unit content of the polypropylene block of the block copolymer (A) is usually 100% by mass.
The content of propylene units in the polypropylene block in the block copolymer (A) can be determined by infrared spectroscopy.

The melting point (Tm) of the block copolymer (A) is preferably high from the viewpoints of heat resistance and autoclave sterilization resistance, and is typically 120°C or higher, preferably 130°C or higher. It is typically 165°C or lower. The melting point of the silylated polypropylene is measured using a differential scanning calorimeter (DSC).

The number of dimethylsilyl groups per 1000 propylene structures in the block copolymer (A) is preferably 50 to 300, more preferably 70 to 200. When the number of dimethylsilyl groups (Si(CH ₃ ) ₂ ) per 1000 propylene structures in the block copolymer (A) is equal to or greater than the lower limit, the block copolymer (A) tends to exhibit low protein adsorption, whereas when the number is equal to or less than the upper limit, the block copolymer (A) tends to be more compatible with polyolefin resins, and the block copolymer (A) tends to have excellent strength and appearance when formed into a medical molded article.

Here, the number of dimethylsilyl groups per 1000 propylene structures in the block copolymer (A) can be determined using the following formula (1) in ¹ H-NMR of the block copolymer (A).
Number of dimethylsilyl groups per 1000 propylene structures (—CH ₂ —CH(CH ₃ )—)=1000×(integral value of dimethylsilyl signals in the region of 0.1 to 0.3 ppm/6)/(integral value of signals derived from the main chain in the region of 0.5 to 2.40 ppm/6) (1)

The number of hydrosilyl groups (S—H) per 1,000 propylene structures in the block copolymer (A) is not particularly limited, but is preferably 100 or less, more preferably 50 or less, and even more preferably 10 or less. Since the SH groups of the silicone react with the double bonds of the unsaturated PP, the SH groups represent unreacted portions.
Here, the number of hydrosilyl groups per 1000 propylene structures in the block copolymer (A) can be determined using the following formula (2) in ¹ H-NMR of the block copolymer (A).
Number of hydrosilyl groups per 1000 propylene structures=1000×(integral value of hydrosilyl signals in the region of 4.8 to 5.0 ppm)/((integral value of signals derived from the main chain in the region of 0.5 to 2.40 ppm)/6) (2)

The number of dimethylsilyl groups per 1,000 propylene structures derived from the block copolymer (A) in the thermoplastic resin composition of the present invention refers to dimethylsilyl groups covalently bonded to the block copolymer (A) in the thermoplastic resin composition, and does not include Si components such as unreacted silicone not covalently bonded to the block copolymer (A) and other components such as silicone oil.
The number of dimethylsilyl groups per 1,000 propylene structures derived from the block copolymer (A) in the thermoplastic resin composition of the present invention is measured as follows.
First, unreacted silicone not covalently bonded to the block copolymer (A) contained in the thermoplastic resin composition and other silicone oils, etc. are removed. Examples of methods for removing unreacted silicone not covalently bonded to the block copolymer (A) of the present invention and other silicone oils, etc. include a method of adding the thermoplastic resin composition to a solvent such as toluene or xylene, dissolving by heating, adding a poor solvent such as isopropyl alcohol, reprecipitating and filtering, and then washing with heptane or acetone.
The unreacted silicone and other components such as silicone oil are removed by the above method, and the resulting sample is used for ¹ H-NMR measurement. From the obtained ¹ H-NMR spectrum, the number of dimethylsilyl groups and the number of hydrosilyl groups per 1,000 propylene structures derived from the block copolymer (A) in the thermoplastic resin composition are calculated by the same method as above.

The number of dimethylsilyl groups per 1,000 propylene structures contained in the thermoplastic resin composition is preferably 2.5 to 210, more preferably 4 to 150.
When the number of dimethylsilyl groups per 1,000 propylene structures in the thermoplastic resin composition is equal to or greater than the lower limit, the composition tends to exhibit low protein adsorption, whereas when the number is equal to or less than the upper limit, the composition tends to be more compatible with polyolefin resins, and the composition tends to have excellent strength and appearance when formed into a medical molded article.
The number of dimethylsilyl groups is based on the propylene structure contained in the thermoplastic resin composition, i.e., based on the propylene structure constituting the block copolymer (A) and the propylene structure of the polypropylene resin contained in the polyolefin resin (B).

The number average molecular weight of the block copolymer (A) is preferably 8,000 or more, more preferably 10,000 or more. It is also preferably 100,000 or less, more preferably 75,000 or less, and even more preferably 50,000 or less. If the number average molecular weight of the block copolymer (A) is at or above the lower limit, the strength tends to be excellent, and if it is at or below the upper limit, the moldability tends to be excellent.

[Method for producing block copolymer (A)]
The block copolymer (A) of the present invention can be produced, for example, by reacting (a) a polypropylene having an unsaturated bond group with (b) a siloxane copolymer having the following structural units (I) and (II):

[(a) Polypropylene having unsaturated bond groups]
In the present invention, the polypropylene (a) having an unsaturated bond group preferably has an unsaturated bond group at at least one terminal of the polypropylene structure. Examples of this unsaturated bond group include a vinylidene group (CH ₂ ═C<).
Examples of polypropylenes having vinylidene groups can be represented by the following general formulas (III) and (IV).

In addition, "PP" in the general formulas (III) and (IV) represents a polypropylene structure.
Incidentally, this (a) polypropylene having an unsaturated bond group may contain a segment derived from a comonomer other than propylene in the main chain, as long as the effects of the present invention are not impaired.

(Number of unsaturated bonds)
In the above-mentioned (a) polypropylene having unsaturated bond groups, the number of unsaturated bond groups in the polypropylene having unsaturated bond groups can be calculated from the results of ¹ H-NMR measurement using the following formula (3), where x is the number of unsaturated bonds contained in one unsaturated bond group.
(Number of unsaturated bond groups × x) / 1,000 propylene structures = 1000 × (integral value of signals derived from unsaturated bond groups / number of hydrogen atoms in unsaturated bond groups) / (integral value of signals derived from the main chain in the 3.0-0.5 ppm region / number of hydrogen atoms in the propylene structure (—CH ₂ —CH(CH ₃ )—))
…(3)
For example, when the unsaturated bond is a vinyl group, a vinylidene group, or a vinylene group, it can be determined from the results of the ¹ H-NMR measurement shown below using the following formulas (3-1) to (3-3), respectively.
Number of vinyl groups/1,000 propylene structures=1000×((integral value of vinyl signals in the 4.9-5.1, 5.7-5.9 ppm region)/3)/((integral value of signals derived from the main chain in the 3.0-0.5 ppm region)/6) (3-1)
Number of vinylidene groups/1,000 propylene structures=1000×((integral value of vinylidene signals at 4.69 and 4.74 ppm)/2)/((integral value of signals derived from the main chain in the 3.0-0.5 ppm region)/6) (3-2)
Number of vinylene groups/1,000 propylene structures=1000×((integral value of vinylene signals in the 5.3-5.5 ppm region)/2)/((integral value of signals derived from the main chain in the 3.0-0.5 ppm region)/6) (3-3)

The number of unsaturated bond groups per 1,000 propylene structures (propylene units) of the (a) polypropylene having unsaturated bond groups used in the present invention is 1.0 or more, preferably 2.0 or more, and more preferably 3.0 or more. Or, it is usually 10.0 or less, preferably 8.0 or less, and more preferably 6.0 or less. By ensuring that the number of unsaturated bond groups is at or above the above-mentioned lower limit, the silylated polypropylene of the present invention can fully exhibit its effects such as water repellency, oil repellency, stain resistance, and non-adhesiveness. Furthermore, by ensuring that the number of unsaturated bond groups is at or below the above-mentioned upper limit, the compatibility between the silylated polypropylene of the present invention and polypropylene can be fully exhibited.

((a) Number average molecular weight of polypropylene having unsaturated bond groups)
The number average molecular weight (Mn) of the polypropylene having (a) unsaturated bond groups used in the present invention is usually 8,000 or more, preferably 9,000 or more, and more preferably 10,000 or more, from the viewpoint of the heat resistance, viscoelasticity, and other mechanical properties of the silylated polypropylene and compositions containing it to be produced. Furthermore, the number average molecular weight is usually 200,000 or less, preferably 150,000 or less, and more preferably 100,000 or less. When it is below the upper limit, it is easy to achieve both mechanical properties and the physical properties of the silylated polypropylene. The number average molecular weight can be determined by GPC measurement.

(a) Method for producing polypropylene having unsaturated bond groups)
The method for producing the polypropylene having an unsaturated bond group (a) used in the present invention is not particularly limited, and any conventionally known method for producing a polypropylene having an unsaturated bond group can be used as appropriate. A production method in which an unsaturated bond group is introduced into one or both ends of a polypropylene molecule by scission of the molecular chain through thermal decomposition or radical decomposition is preferred. For example, when the unsaturated bond group is a vinylidene group, a method in which a high-molecular-weight polypropylene is thermally degraded in an inert gas atmosphere, typically at 300 to 450°C for 0.5 to 10 hours, is used to continuously produce the polypropylene.
In addition, the polypropylene (a) having an unsaturated bond group used in the present invention may be a commercially available product. Specifically, when the unsaturated bond group is a vinylidene group, it can be procured from the manufacturers listed below and can be selected appropriately. Specific examples of commercially available products include Viscol (registered trademark) from Sanyo Chemical Industries, Ltd. and Hiwax (registered trademark) from Mitsui Chemicals, Inc.

[(b) Siloxane copolymer]
The siloxane copolymer (b) used in the present invention is a siloxane copolymer having the following structural units (I) and (II).

In formulas (I) and (II), R ₁ to R ₃ each independently represent a hydrocarbon group having 1 to 10 carbon atoms. R ₁ to R ₃ are preferably hydrocarbon groups having 1 to 6 carbon atoms, and particularly preferably methyl groups.

The (b) siloxane copolymer used in the present invention contains the structural units (I) and (II). The structural unit (I) is a structural unit necessary for exhibiting excellent surface properties, such as water repellency, oil repellency, stain resistance, adhesion, adsorption, and gas permeability, expected from silylation. The structural unit (II) is a structural unit necessary for the reaction with the polypropylene having the unsaturated bond group described above. The (b) siloxane copolymer used in the present invention only needs to contain the amount of structural unit (II) necessary for reaction with the polypropylene having the unsaturated bond group, and it is preferable that the amount of structural unit (II) is not too large. If the amount of structural unit (II) is too large, side reactions often occur during the reaction between the polypropylene having the unsaturated bond group (a) and the siloxane copolymer (b), which is undesirable from the perspective of selectivity. On the other hand, a large amount of structural unit (I) is preferable to enhance the properties expected from silylation.

From this perspective, the (b) siloxane copolymer used in the present invention preferably has a ratio of the number of structural units (II) to the total number of structural units (I) and (II), i.e., number of structural units (II)/{number of structural units (II) + number of structural units (I)}, of 0.8 or less, more preferably 0.6 or less, and even more preferably 0.4 or less. Meanwhile, this ratio is typically 0.01 or more, preferably 0.05 or more. Within this range, a good balance between affinity with thermoplastic resins such as polypropylene and the effects of silylation tends to be achieved.

The method for calculating the number of each of the structural units (I) and (II) is as follows.
First, the structural unit (I) (pieces) and the structural unit (II) (pieces) have the relationship of the following formula (4).
Number average molecular weight Mn (g/mol) of siloxane copolymer = molecular weight of both terminal portions + structural unit (II) (number) × molecular weight of structural unit (II) + structural unit (I) (number) × molecular weight of structural unit (I) ... (4)

The number of structural units (II) can be calculated from the Si-H reactive group substitution ratio (mmol/g) of each siloxane copolymer. To calculate the number of structural units (I), the number average molecular weight Mn of the siloxane copolymer, the molecular weights of both terminal portions, the molecular weight of structural unit (II), and the molecular weight of structural unit (I) are required. Here, for simplicity, a case where the substituents at both terminal portions, R ₁ to R ₃ , are all methyl groups will be described.
The molecular weights of the terminal portions, structural unit (I), and structural unit (II) can be expressed as the molecular weights of the structural units represented by [a], [b], and [c], respectively. The molecular weights corresponding to these structures are Mn[a] = 162.38, Mn[b] = 60.13, and Mn[c] = 74.15.

On the other hand, the number average molecular weight (Mn) of the siloxane copolymer was calculated using the kinematic viscosity (cSt) η of each siloxane copolymer at 25°C, using Barry's equation log η = 1.00 + 0.0123 × Mn ^0.5
(J. Appl. Physics, 1946, 17, 1020), where η is the kinematic viscosity (cSt) at 25° C., and Mn is the number average molecular weight.
The number of structural units (I) can be calculated by substituting this Mn, the molecular weights of the structural units (II), both terminal portions, the structural unit (I), and the structural unit (II) into the formula (4). The number of structural units (I) and (II) can also be calculated from the amounts of the structural units (I) and (II) charged.

The kinematic viscosity η at 25°C of the (b) siloxane copolymer used in the present invention is typically 1 cSt or more, preferably 5 cSt or more, more preferably 10 cSt or more, and particularly preferably 50 cSt or more. When the kinematic viscosity is above the lower limit, the molecular weight of the (b) siloxane copolymer is sufficiently large, and accordingly, it contains a large amount of structural unit (I), which results in greater surface properties such as water repellency, oil repellency, stain resistance, and adhesion, as well as greater gas permeability.

The number average molecular weight (Mn) of the (b) siloxane copolymer used in the present invention is usually in the range of 500 or more, preferably 1000 or more. For the same reason as for the kinematic viscosity, the larger the molecular weight of the (b) siloxane copolymer, the greater the effects of surface properties such as water repellency, oil repellency, antifouling properties, and adhesion, as well as gas permeability, but the upper limit of the number average molecular weight (Mn) of the (b) siloxane copolymer is usually 20000 or less. Here, the number average molecular weight of the (b) siloxane copolymer is calculated using the kinematic viscosity (cSt) η at 25°C, as described above, using Barry's equation log η = 1.00 + 0.0123 × Mn ^0.5
(J. Appl. Physics, 1946, 17, 1020).

The melting point (Tm) of the silylated polypropylene used in the present invention is not particularly limited, but from the viewpoint of the heat resistance, viscoelasticity, and other mechanical properties of the silylated polypropylene produced and compositions containing it, a higher melting point is preferable, and is typically 120°C or higher, preferably 130°C or higher. It is typically 165°C or lower. The melting point of the silylated polypropylene is measured using a differential scanning calorimeter (DSC).

Commercially available siloxane copolymers (b) suitable for the present invention include "XL-116" manufactured by Nusil Technology, which was used in the examples below, as well as the following. The following also shows the results of calculating structural unit (II)/{structural unit (I) + structural unit (II)} for each siloxane copolymer, based on the number of structural units (I) and the number of structural units (II).

i) Manufactured by Nusil Technology, product name “XL-110”
Methylhydrosiloxane dimethylsiloxane copolymer Number average molecular weight: 1,047
・Kinematic viscosity (25℃): 4cSt
Si—H reactive group substitution ratio: 7.0 mmol/g
Refractive index: 1.40
Structural unit (II) / {structural unit (II) + structural unit (I)}: 0.55

ii) Nusil Technology, product name "XL-115"
Methylhydrosiloxane dimethylsiloxane copolymer Number average molecular weight: 3,229
・Kinematic viscosity (25℃): 50cSt
Si—H reactive group substitution ratio: 4.2 mmol/g
Refractive index: 1.40
Structural unit (II) / {structural unit (I) + structural unit (II)}: 0.31

[Reaction of (a) Polypropylene Having Unsaturated Bond Groups with (b) Siloxane Copolymer]
In one embodiment of the hydrosilylation reaction of (a) polypropylene having unsaturated bond groups with (b) a siloxane copolymer according to the present invention, a transition metal complex catalyst is used. This catalyst is preferably a complex of a transition metal from Groups 8 to 10 of the periodic table, such as a platinum complex, a rhodium complex, a cobalt complex, a palladium complex, or a nickel complex. Among these, platinum catalysts are preferred for use in the present invention, and platinum complexes such as chloroplatinic acid and platinum olefin complexes are particularly preferred. The catalyst is typically used in an amount of about 0.1 to 1,000 ppm by mass, preferably 1 to 500 ppm by mass, and particularly preferably 5 to 100 ppm by mass, calculated as metal, relative to (a) polypropylene having unsaturated bond groups.

The charging ratio ((a)/(b)) (molar ratio) of the (a) polypropylene having an unsaturated bond group to the (b) siloxane copolymer, when a vinylidene group is used as the unsaturated bond group in the (a) polypropylene having an unsaturated bond group (hereinafter, sometimes referred to as "(a) polypropylene having a vinylidene group"), is usually 1:0.1 to 30, preferably 1:0.5 to 10. In order to effectively carry out the hydrosilylation reaction between the unsaturated bond group in the (a) polypropylene having a vinylidene group and the hydrosilyl group in the (b) siloxane copolymer, it is necessary to charge an excess of the (b) siloxane copolymer over the (a) polypropylene having a vinylidene group.
When an unsaturated bond group other than a vinylidene group is used as the unsaturated bond group of the (a) polypropylene having an unsaturated bond group, when the number of unsaturated bonds contained in one unsaturated bond group is defined as x, the charge ratio (molar ratio) of the (a) polypropylene having an unsaturated bond group to the (b) siloxane copolymer, ((a) × x)/(b)), may satisfy the above-mentioned range.

The hydrosilylation reaction may be carried out in a molten state or in a solution state (hereinafter, these may be referred to as a "melt reaction" and a "solution reaction," respectively). In the case of a melt reaction, the reaction temperature must be equal to or higher than the melting temperature of (a) the polypropylene having unsaturated bond groups, and is typically about 100 to 250°C, preferably 150 to 200°C. In the case of a solution reaction, the reaction temperature is typically about -30 to 150°C, preferably 30 to 140°C. The reaction time is about 1 minute to 20 hours. The hydrosilylation reaction is typically carried out at atmospheric pressure, but may also be carried out under pressure.

Typical processing equipment (e.g., extruders, batch mixers, hot presses, etc.) can be used for the melt reaction. The reaction can be carried out batchwise or continuously. This melt reaction is carried out in the molten phase of (a) polypropylene having unsaturated bond groups. In this case, (a) polypropylene having unsaturated bond groups, (b) siloxane copolymer, and transition metal complex catalyst can be mixed before the reaction or added sequentially to a reactor.

In the solution reaction, there are no particular limitations on the reaction apparatus; for example, a batch or continuous tank-type reaction unit equipped with a stirring device can be used. Examples of reaction solvents used in solution reactions include hydrocarbon solvents and ether-based solvents. Examples of hydrocarbon solvents include saturated aliphatic hydrocarbons such as hexane, heptane, octane, and decane; saturated alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and aromatic hydrocarbons such as benzene, toluene, and xylene. Hydrocarbon solvents are preferred, with saturated alicyclic hydrocarbons and aromatic hydrocarbons being more preferred.

There are no particular restrictions on the amount used, as long as the polymer remains dissolved. Typically, however, the total concentration of (a) polypropylene having unsaturated bond groups and (b) siloxane copolymer is 5 to 50% by mass, and preferably 10 to 40% by mass.

<Polyolefin Resin (B)>
The polyolefin resin (B) used in the present invention is not particularly limited, and conventionally known polyolefin resins such as polyethylene resins and polypropylene resins can be used. Among these, polypropylene resins are preferred from the viewpoints of heat resistance, rigidity, and moldability.
The polyethylene resin is a polyolefin resin having an ethylene unit content of more than 50% by mass relative to all monomer units. The polyethylene resin contributes to flexibility of the medical molded article of the present invention.

Examples of the polyethylene resin include ethylene homopolymers such as high-pressure low-density polyethylene (LDPE) and high-density polyethylene (HDPE); ethylene-α-olefin copolymers such as ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, ethylene-propylene-butene copolymer, ethylene-propylene-hexene copolymer, ethylene-propylene-octene copolymer, ethylene-butene-hexene copolymer, ethylene-butene-octene copolymer, and ethylene-hexene-octene copolymer; and ethylene (co)polymers such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-methyl (meth)acrylate copolymer, ethylene-ethyl (meth)acrylate copolymer, and ethylene-(meth)acrylic acid-methyl (meth)acrylate copolymer. Here, "(co)polymer" refers to a polymer and/or copolymer.

The melt flow rate (MFR) of the polyethylene resin is preferably 0.05 g/10 min or more, and from the viewpoint of fluidity, more preferably 0.1 g/10 min or more, and even more preferably 0.5 g/10 min or more. It is also preferably 100 g/10 min or less, and from the viewpoint of moldability, more preferably 70 g/10 min or less, and even more preferably 50 g/10 min or less. This MFR can be measured in accordance with ISO R3133 at a measurement temperature of 190°C and a measurement load of 2.16 kg.

The polypropylene-based resin is a polyolefin resin having a propylene unit content of 50% by mass or more relative to all monomer units. In the medical molded article of the present invention, the polypropylene-based resin contributes to strength and moldability.

As the polypropylene-based resin, any of a propylene homopolymer, a propylene random copolymer, and a propylene block copolymer can be used.
When the polypropylene-based resin is a propylene random copolymer, examples of the monomer copolymerizable with propylene include ethylene, 1-butene, 2-methylpropylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene.

When the polypropylene-based resin is a propylene block copolymer, examples of the propylene block copolymer include those obtained by multi-stage polymerization, more specifically, those obtained by polymerizing polypropylene in a first stage and polymerizing a propylene-ethylene copolymer in a second stage.
The content of propylene units in the polypropylene-based resin is preferably 60% by mass or more, more preferably 75% by mass or more, and even more preferably 90% by mass or more. When the content of propylene units is equal to or greater than the lower limit, the heat resistance and rigidity are improved. The upper limit of the content of propylene units in the polypropylene-based resin is usually 100% by mass. The content of propylene units in the polypropylene-based resin can be determined by infrared spectroscopy.

The melt flow rate (MFR) of the polypropylene resin is preferably 0.05 g/10 min or more, more preferably 0.1 g/10 min or more, and even more preferably 0.5 g/10 min or more from the viewpoint of flowability, and is preferably 100 g/10 min or less, and from the viewpoint of moldability, more preferably 70 g/10 min or less, and even more preferably 50 g/10 min or less.
The MFR can be measured in accordance with ISO R3133 under conditions of a measurement temperature of 230° C. and a measurement load of 2.16 kg.

The polypropylene resin can be produced by a known polymerization method using an olefin polymerization catalyst. For example, a multi-stage polymerization method using a Ziegler-Natta catalyst can be used. This multi-stage polymerization method can be a slurry polymerization method, a solution polymerization method, a bulk polymerization method, a gas phase polymerization method, or the like, and two or more of these methods can be used in combination to produce the polypropylene resin.
The polyolefin resin may be used alone or in combination of two or more kinds.

Commercially available products can be used as the polyolefin resin of the present invention. Specific examples of commercially available polyethylene resins include the "Novatec (registered trademark) HD," "Novatec (registered trademark) LD," and "Novatec (registered trademark) LL" series manufactured by Japan Polyethylene Corporation; the "Creolex (registered trademark)," "Suntec-HD (registered trademark)," and "Suntec-LL (registered trademark)" series manufactured by Asahi Kasei Chemicals Corporation; the "Hi-Zex (registered trademark)" series, "Evolue-H (registered trademark)," and "Evolue (registered trademark)" series manufactured by Prime Polymer Co., Ltd.; and the "QAMAR-HD (registered trademark)" and "QAMAR (registered trademark)" series manufactured by Saudi Petrochemical Co., Ltd.

Specific examples of commercially available polypropylene resins include "Novatec (registered trademark) PP" manufactured by Japan Polypropylene Corporation, "Prim Polypro (registered trademark)" manufactured by Prime Polymer Co., Ltd., "Sumitomo Noblen (registered trademark)" manufactured by Sumitomo Chemical Co., Ltd., "Polypropylene Block Copolymer" manufactured by SunAllomer Co., Ltd., "Moplen (registered trademark)" manufactured by LyondellBasell, "ExxonMobil PP" manufactured by ExxonMobil, "Formolene (registered trademark)" manufactured by Formosa Plastics, "Borealis PP" manufactured by Borealis, "SEETEC PP" manufactured by LG Chemical, and A. Examples include "ASI POLYPROPYLENE" manufactured by Schulman, "INEOS PP" manufactured by INEOS Olefins & Polymers, "Braskem PP" manufactured by Braskem, "Samsung Total" manufactured by SAMSUNG TOTAL PETROCHEMICALS, "Sabic (registered trademark) PP" manufactured by Sabic, "TOTAL PETROCHEMICALS Polypropylene" manufactured by TOTAL PETROCHEMICALS, and "YUPLENE (registered trademark)" manufactured by SK Corporation.

<Thermoplastic resin composition for medical use>
The medical thermoplastic resin composition of the present invention comprises a thermoplastic resin composition containing the block copolymer (A) and the polyolefin resin (B).
In the thermoplastic resin composition, the mass ratio represented by [mass of block copolymer (A)]/[mass of polyolefin resin (B)] is preferably 5/95 to 70/30, more preferably 6/94 to 65/35, and more preferably 7/93 to 60/40. Within this range, low adsorption and good strength are achieved.

<Other ingredients>
The medical thermoplastic resin composition of the present invention may contain, as other components, compounding agents that are commonly used in resin compositions, to the extent that the effects of the present invention are not impaired.
Examples of additives include various heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antioxidants, nucleating agents, plasticizers, impact modifiers, compatibilizers, antifoaming agents, thickeners, crosslinking agents, surfactants, lubricants, antiblocking agents, processing aids, antistatic agents, flame retardants, flame retardant assistants, fillers, colorants, and inorganic crystal nucleating agents.

Examples of the heat stabilizers and antioxidants include hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, and alkali metal halides. Flame retardants are broadly classified into halogenated and non-halogenated flame retardants, with non-halogenated flame retardants being preferred from an environmental perspective. Non-halogenated flame retardants include phosphorus-based flame retardants, hydrated metal compound (aluminum hydroxide, magnesium hydroxide) flame retardants, nitrogen-containing compound (melamine-based, guanidine-based) flame retardants, and inorganic compound (borate, molybdenum compound) flame retardants.

The fillers are broadly divided into organic fillers and inorganic fillers. Organic fillers include naturally occurring polymers such as starch, cellulose particles, wood flour, soybean pulp, rice husks, and bran, as well as modified versions of these. Inorganic fillers include talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass balloons, carbon black, zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fibers, metal whiskers, ceramic whiskers, potassium titanate, boron nitride, graphite, and carbon fibers.

The nucleating agents include sorbitol compounds and their metal salts; benzoic acid and its metal salts; phosphate metal salts; ethylene bisoleic acid amide, methylene bisacrylic acid amide, ethylene bisacrylic acid amide, hexamethylene bis-9,10-dihydroxystearic acid bisamide, p-xylylene bis-9,10-dihydroxystearic acid amide, decanedicarboxylic acid dibenzoyl hydrazide, hexanedicarboxylic acid dibenzoyl hydrazide, 1,4-cyclohexanedicarboxylic acid dicyclohexylamide, 2,6-naphthalenedicarboxylic acid diamide, Examples of suitable amide compounds include dianilide, N,N',N"-tricyclohexyl trimesic acid amide, trimesic acid tris(t-butylamide), 1,4-cyclohexanedicarboxylic acid dianilide, 2,6-naphthalenedicarboxylic acid dicyclohexylamide, N,N'-dibenzoyl-1,4-diaminocyclohexane, N,N'-dicyclohexanecarbonyl-1,5-diaminonaphthalene, ethylenebisstearic acid amide, N,N'-ethylenebis(12-hydroxystearic acid)amide, and octanedicarboxylic acid dibenzoylhydrazide. Examples of suitable inorganic crystal nucleating agents include talc, kaolin, and silica.

Among these, it is preferable to add an antioxidant, particularly a phenol-based, sulfur-based, or phosphorus-based antioxidant. The antioxidant is preferably added in an amount of 0.01 to 2.0 parts by mass, more preferably 0.01 to 1.0 part by mass, even more preferably 0.01 to 0.5 parts by mass, and particularly preferably 0.01 to 0.2 parts by mass, per 100 parts by mass of the thermoplastic resin composition.

Furthermore, resin components other than the block copolymer (A) and the polyolefin resin (B) and elastomer components may be contained within the range that does not impair the effects of the present invention.
Examples of such resin components include cyclic polyolefin resins, polystyrene resins, polyvinyl chloride resins, polyester resins, polyamide resins, acrylic resins, and petroleum resins.
Examples of the elastomer component include olefin elastomers, styrene elastomers, polyester elastomers, urethane elastomers, acrylic elastomers, and nylon elastomers.

The other components may be added to the block copolymer (A) and the polyolefin resin (B) by a kneading method commonly used for melt-kneading thermoplastic resins, or may be dissolved in an organic solvent together with the block copolymer (A) and mixed.
The content of the other resin components and elastomer components is preferably 50% by mass or less, and more preferably 30% by mass or less, when the entire thermoplastic resin composition is taken as 100% by mass.

<Method of producing a medical thermoplastic resin composition>
The medical thermoplastic resin composition of the present invention can be produced by kneading the block copolymer (A), the polyolefin resin (B), and, if necessary, the other components in a conventional manner using a conventional extruder, Banbury mixer, roll, Brabender Plastograph, Kneader-Brabender, or the like.
Among these production methods, it is preferable to use an extruder, particularly a twin-screw extruder.
When the medical thermoplastic resin composition of the present invention is produced by kneading using an extruder or the like, it is melt-kneaded in a heated state, usually at 170 to 300°C, preferably 190 to 230°C.

<Medical Molded Product and Its Manufacturing Method>
By molding the medical thermoplastic resin composition of the present invention, various medical molded articles can be obtained.
As a molding method, for example, various molding methods such as injection molding (insert molding, two-color molding, sandwich molding, gas injection molding, injection blow molding, etc.), extrusion molding, inflation molding, T-die film molding, lamination molding, blow molding, hollow molding, compression molding, and calendar molding can be used to process the resin into various molded articles.
In either molding method, the molding temperature is 180 to 300°C, preferably 200 to 240°C. In the case of injection molding, the injection pressure is 5 to 100 MPa, preferably 10 to 80 MPa. The mold temperature is 0 to 100°C, preferably 20 to 95°C, and more preferably 30 to 90°C. In the case of T-die molding, the chill roll temperature is 10 to 95°C, preferably 20 to 90°C.

<Applications of medical molded articles>
The medical molded article of the present invention can be suitably used for plastic slides; drug storage containers such as eye drop containers, medicine bottles, ampoules, and vials; sampling containers such as test tubes, blood collection tubes, and specimen containers; and syringes such as prefilled syringes and injector syringes. It is particularly suitable for applications involving handling biopharmaceuticals having a protein structure.

<Medical laminate>
Next, the medical laminate of the present invention will be described.
The thermoplastic resin composition of the present invention can be molded to obtain various medical laminates.
The medical laminate of the present invention has a base layer containing a polyolefin resin and a low-adsorption layer made of the medical thermoplastic resin composition of the present invention. The base layer is preferably made of a polypropylene resin from the viewpoints of heat resistance and moldability.
In the laminate of the present invention, the low adsorption layer of the present invention and the base layer are preferably laminated so that they are in direct contact with each other without an intermediate layer therebetween. The low adsorption layer has heat sealing properties and can be laminated directly to the base layer.

The medical laminate of the present invention can be manufactured by any method that can laminate the above-mentioned layers together, including, for example, dry lamination, extrusion lamination, co-extrusion lamination (T-die method, water-cooled inflation method, air-cooled inflation method), heat lamination, and lamination methods that combine these methods. Of these, the water-cooled inflation method is particularly preferred from the perspectives of obtaining transparency for the entire laminate and obtaining airtightness for the inner layer.

In the medical laminate of the present invention, the thickness of each layer can be selected appropriately depending on the intended use, but the thickness of the low-adsorption layer of the present invention is preferably 5 to 100 μm, and particularly preferably 10 to 50 μm. A thickness of the low-adsorption layer within the above lower limit range is preferred from the standpoint of low-adsorption properties and heat seal strength.

In the medical laminate of the present invention, the thickness of the base layer of the present invention is 100 μm or more, for example, preferably 140 to 330 μm, and particularly preferably 150 to 250 μm. When the thickness of the base layer of the present invention is within the above-mentioned lower limit range, the mechanical strength and transparency are excellent.
In particular, the thickness ratio of the layers of the laminate of the present invention, low adsorption layer:substrate layer, is preferably 1:30 to 1:3.

<Applications of medical laminate>
The medical laminate of the present invention has excellent low adsorption properties and can therefore be suitably used as medical containers such as medical packaging bags, and is particularly suitable for use as infusion bags.
The medical container can be produced using the laminate by a sheet forming method (thermoforming method) such as vacuum forming or pressure forming, a blow molding method such as multilayer coextrusion blow molding, or a method in which the peripheral edges of sheets of the laminate cut into a predetermined shape are bonded together by heat fusion (strong welding) or with an adhesive to produce a bag-like product, etc. This is particularly suitable for applications involving handling biopharmaceuticals having a protein structure.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
The evaluation methods and resins used in the examples and comparative examples are as follows.

[Evaluation method]
<Measurement of number average molecular weight Mn of polypropylene having unsaturated bond groups>
Approximately 20 mg of sample was placed in a vial for a PL-SP260VS high-temperature GPC pretreatment device manufactured by Polymer Laboratory, and o-dichlorobenzene containing BHT as a stabilizer (BHT concentration = 0.5 g/L) was added to adjust the polymer concentration to 0.1 (mass%). The polymer was heated to 135°C in the PL-SP260VS high-temperature GPC pretreatment device to dissolve it, and then filtered through a glass filter to prepare a sample. Note that in this GPC measurement, no polymer was trapped in the glass filter.
Next, GPC measurement was performed using a Waters V2000 equipped with a TSKgel GMH-HT (30 cm x 4 columns) manufactured by Tosoh Corporation and an RI detector. The measurement conditions were as follows: sample solution injection volume: 524.5 μl, column temperature: 135°C, solvent: o-dichlorobenzene, flow rate: 1.0 ml/min.
The molecular weight was calculated as follows: A commercially available monodisperse polystyrene was used as a standard sample, and a calibration curve relating retention time to molecular weight was created from the viscosity equation of the polystyrene standard sample and polypropylene, and the molecular weight was calculated based on the calibration curve.
The viscosity formula used was [η] = K × Mα, where K = 1.38 × 10 4 and α = 0.70 were used for polystyrene, and K = 1.03 × 10 4 and α = 0.78 were used for polypropylene.

<Measurement of the number of unsaturated bond groups in polypropylene having unsaturated bond groups>
200-300 mg of sample was placed in a 10 mm inner diameter NMR sample tube together with 2.4 ml of o-dichlorobenzene/deuterated bromide benzene (C ₆ D ₅ Br) = 4/1 (volume ratio) and hexamethyldisiloxane, a chemical shift standard substance, and the tube was purged with nitrogen, sealed, heated, dissolved, and subjected to NMR measurement as a homogeneous solution. NMR measurements were performed using an AVANCE III 400 NMR spectrometer from Bruker Biospin, Inc., equipped with a 10 mm diameter cryoprobe.
^{The 1} H-NMR measurements were performed at a sample temperature of 80° C., a pulse angle of 4.5°, a pulse interval of 2 seconds, and an accumulation count of 512.
The number of unsaturated bond groups per 1000 propylene structures of polypropylene having unsaturated bond groups was calculated from the results of ¹ H-NMR measurement as follows, and the total value was used.
Number of vinyl groups / 1,000 propylene structures = 2000 x (integral value of vinyl signals in the 4.9-5.1, 5.7-5.9 ppm range) / (integral value of signals derived from the main chain in the 3.0-0.5 ppm range)
Number of vinylidene groups / 1,000 propylene structures = 3,000 x (integral value of vinylidene signals at 4.69 and 4.74 ppm) / (integral value of signals derived from the main chain in the 3.0-0.5 ppm region)
Number of vinylene groups / 1,000 propylene structures = 3,000 x (integral value of vinylene signals in the 5.3-5.5 ppm region) / (integral value of signals derived from the main chain in the 3.0-0.5 ppm region)
^{The 13} C-NMR measurements were performed by the inverse gate decoupling method under the conditions of a sample temperature of 80° C., a pulse angle of 90°, a pulse interval of 51.5 seconds, and an accumulation number of 1024.

<Measurement of Melting Point (Tm) of Polypropylene Having Unsaturated Bond Groups>
Using a Perkin-Elmer PYRIS Diamond DSC differential scanning calorimeter, a sample (approximately 5 mg) was melted at 210°C for 5 minutes, cooled to -20°C at a rate of 10°C/min, held at -20°C for 5 minutes, and then heated to 210°C at a rate of 10°C/min to obtain a melting curve. The peak-top temperature of the main exothermic peak during the cooling step was defined as the crystallization temperature Tc. The peak-top temperature of the main endothermic peak during the final heating step performed to obtain the melting curve was defined as the melting point Tm.

<Strength>
Using the obtained thermoplastic resin composition, plates (test pieces) of 2 mm thick x 40 mm wide x 80 mm long were molded using an in-line screw type injection molding machine ("SE18D" manufactured by Sumitomo Heavy Industries, Ltd.) at an injection pressure of 50 MPa, a cylinder temperature of 250°C, and a mold temperature of 50°C. Test pieces that cracked when removed were rated as x, and those that had no cracks were rated as o. Note that those without cracks had excellent strength.

<Adsorption amount>
A 10 mm x 40 mm piece was punched out from the plates (test pieces) obtained above that had no cracks, to prepare test pieces.
The test piece was treated with albumin (bovine,
The test piece was immersed in a 1 mg/mL solution of sodium dodecyl sulfate (BSA) for 2 hours at 37° C. After immersion for 2 hours, the test piece was washed with PBS, and then immersed in 6 mL of an aqueous solution of sodium dodecyl sulfate and subjected to ultrasonic cleaning for 5 minutes.
150 μL of the solution after ultrasonic cleaning was placed in a 96-well plate, and 150 μL of a protein quantification reagent from a commercially available BCA kit was placed in the same portion of the solution after ultrasonic cleaning, followed by 2 hours at 37° C. After 2 hours of storage, the absorbance at 562 nm was measured using a plate reader, and the amount of adsorbed albumin was calculated by applying this to a calibration curve obtained from albumin solutions of known concentrations.
The adsorption amount of the thermoplastic resin composition of the present invention is an index of low adsorption, and is preferably 0.6 μg/cm ² or less, more preferably 0.4 μg/cm ² or less, and even more preferably 0.2 μg/cm ² or less. The smaller the value, the better the low adsorption property.

[Raw materials]
<Component (a) Polypropylene having unsaturated bond groups>
a-1...Viscol (registered trademark) 330-PSK, manufactured by Sanyo Chemical Industries, Ltd.
・Number average molecular weight (Mn): 12000
Unsaturated bond group: vinylidene group Number of unsaturated bond groups per 1,000 propylene structures: 3.3
Melting point (Tm): 155 ° C.

<Component (b) Siloxane Copolymer>
b-1...Manufactured by Nusil Technology, product name "XL-116"
Methylhydrosiloxane dimethylsiloxane copolymer Number average molecular weight (Mn): 6,610
・Kinematic viscosity (25℃): 100cSt
Si—H reactive group substitution ratio: 0.9 mmol/g
Refractive index: 1.40
Ratio of structural unit (II) (number): 0.07

[Production of silylated polypropylene A-1]
A 500 mL separable flask equipped with a mechanical stirrer was charged with a-1 (37 g, 3.1 mmol), b-1 (10.79 g, 1.6 mmol), and 625 mL of dehydrated toluene, followed by 15 minutes of nitrogen bubbling. The mixture was then heated to 100°C and stirred uniformly. Gelest Inc. platinum catalyst SIP6831.2 (a xylene solution of platinum-divinyltetramethyldisiloxane complex, platinum content: 2.1 to 2.4% by mass, 0.015 mL) was then added, followed by stirring at 100°C for 2.5 hours. 375 mL of heptane was then added, the temperature was lowered to 85°C, and isopropanol (500 mL) was added with stirring to precipitate a polymer. An additional 500 mL of isopropanol was then added, and the mixture was cooled to room temperature. The precipitated polymer was recovered by filtration and washed with heptane (1000 mL x 2 times) and then with acetone (1000 mL x 2 times). The resulting polymer was dried under reduced pressure at 70°C to obtain silylated polypropylene A-1 (yield: 40.2 g).
The physical properties of the resulting silylated polypropylene A-1 are as follows:

<Silylated Polypropylene A-1>
Melting point: 143°C
Number of dimethylsilyl groups per 1,000 propylene structures: 78
Number of hydrosilyl groups per 1,000 propylene structures: 4
・Number average molecular weight: 24,000

<(B) Polyolefin Resin>
B-1: Polypropylene resin, manufactured by Japan Polypropylene Corporation, product name Novatec MA1B
Propylene homopolymer MFR (230°C, load 2.16 kg) 20 g/10 min Density 0.90 g/cm ³
Melting point: 165°C

Example 1
10 parts by mass of (A-1), 90 parts by mass of (B-1), and 0.05 parts of Irgafos 168 manufactured by BASF as an antioxidant were added, and the mixture was fed into a co-rotating twin-screw extruder (manufactured by Technovel Corporation: KZW15-45MG, Φ15, L/D=45) at a rate of 2 kg/h, and the mixture was heated to a temperature in the range of 220°C and melt-kneaded to obtain pellets of a thermoplastic resin composition.
The pellets obtained were used to measure the number of dimethylsilyl groups and the amount of adsorption per 1,000 propylene structures derived from the block copolymer (A) in the thermoplastic resin composition. The results are shown in Table 1.

<Examples 2 and 3, Comparative Examples 1 and 2>
According to the formulation shown in Table 1, melt-kneading was carried out in the same manner as in Example 1, and the various physical properties of the resulting pellets were evaluated. The results are shown in Table 1.
In Comparative Example 2, the amount of adsorption was not measured because cracks occurred when the test piece was removed.

From Table 1, it is clear that Example 1, which is made of the block copolymer (A) corresponding to the present invention and the polyolefin resin (B), is excellent in strength and low adsorption.
In contrast, Comparative Example 1, which did not contain the block copolymer (A), was found to have poor low adsorption properties, and Comparative Example 2, which did not contain the polyolefin resin (B), was found to have poor strength.

The medical molded article of the present invention is highly useful as plastic glass slides; pharmaceutical containers such as eye droppers, medicine bottles, ampoules, and vials; sampling containers such as test tubes, blood collection tubes, and specimen containers; and syringes such as prefilled syringes and syringes.

Claims (10)

The composition contains a block copolymer (A) having a silicone block and a polyolefin block, and a polyolefin resin (B) ,
the block copolymer (A) is a block copolymer having a silicone block and a polypropylene block,
The block copolymer (A) has the following structural unit (I):
(In formula (I), R1 _and R2 _each independently represent a hydrocarbon group having 1 to 10 carbon atoms.)
R ₁ and R ₂ of the structural unit (I) are methyl groups,
the polyolefin resin (B) is a polypropylene resin,
The medical thermoplastic resin composition , wherein the block copolymer (A) has 70 to 200 dimethylsilyl groups per 1,000 propylene structures . 2. The medical thermoplastic resin composition according to claim 1, wherein the number of dimethylsilyl groups per 1,000 propylene structures contained in the thermoplastic resin composition is 4 to 150 . 3. The medical thermoplastic resin composition according to claim 1, wherein the content ratio expressed as [mass of block copolymer (A)]/[mass of polyolefin resin (B)] is 5/95 to 70/30. 4. The medical thermoplastic resin composition according to claim 1, wherein the number average molecular weight of the block copolymer (A) is 8,000 or more and 100,000 or less. A molded article made of the medical thermoplastic resin composition according to any one of claims 1 to 4 . The molded article according to claim 5 , which is one selected from a plastic slide glass, an eye dropper, a medicine bottle ampoule, a vial, a test tube, a blood collection tube, a specimen container, a prefilled syringe, and an injector syringe. A medical laminate comprising a substrate layer containing a polyolefin resin and a layer made of the medical thermoplastic resin composition according to any one of claims 1 to 4 . 8. The medical laminate according to claim 7 , wherein the polyolefin resin constituting the base layer is a polypropylene resin. A medical packaging bag using the medical laminate according to claim 7 or 8 . An infusion bag using the medical packaging bag according to claim 9 .