JP2015124350A - Resin composition, medical tubing formation material, and medical tubing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition, a medical tubing formation material and a medical tubing that achieve both flexibility and slidability.SOLUTION: A resin composition comprises polypropylene 50.6-60.3 mass%, styrenic elastomer 19.6-33.7 mass%, silicone oil 1.6-4.5 mass%, barium sulfate 9.1-17.3 mass%, and pigment 0.3-0.6 mass%.

Description

  The present invention relates to a resin composition, a medical tube forming material, and a medical tube.

In the medical field, flexible tubes (soft tubes) are used for various purposes. For example, a soft tube is used as a catheter or pusher tube that is inserted into a living body through a channel tube of an endoscope.
Endoscope channel tubes are curved, and in medical tubes (catheters, pusher tubes, etc.) inserted into the living body through such channel tubes, the operability of the medical tubes (to the channel tube) In order to improve the operability of the guide wire inserted through the pusher tube, etc., flexibility and slidability are required.
As such a medical tube, a fluororesin such as polytetrafluoroethylene is widely used because it satisfies the above requirements to some extent. However, fluororesins have drawbacks such as difficulty in fine-tuning physical properties such as flexibility and rigidity, and difficulty in coloration.

  On the other hand, a soft tube based on a polypropylene resin has been proposed. For example, in Patent Document 1, as a soft tube used for an infusion tube or the like, a specific propylene random copolymer is more than 5% by weight and less than 30% by weight, and a styrene copolymer elastomer is more than 20% by weight and less than 60% by weight. A soft tube is disclosed in which paraffinic oil is composed of a blending amount of more than 10% by weight and less than 75% by weight.

JP 2003-96263 A

According to the study of the present inventor, the soft tube described in Patent Document 1 has high flexibility, but does not have the slidability required for catheters, pusher tubes, and the like.
In such a flexible tube, flexibility and slidability are in a trade-off relationship. When flexibility is increased, rigidity is lowered, and force is not easily transmitted to the tube during insertion, and slidability is lowered. Therefore, it is difficult to achieve both flexibility and slidability required for catheters, pusher tubes and the like.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the resin composition, medical tube formation material, and medical tube which were compatible in softness | flexibility and slidability.

The present invention has the following aspects.
[1] 50.6-60.3% by mass of polypropylene, 19.6-33.7% by mass of styrene elastomer, 1.6-4.5% by mass of silicone oil, 9.1-17. A resin composition containing 3% by mass and 0.3 to 0.6% by mass of a pigment.
[2] The polypropylene content is 50.6-53.9% by mass, the styrene elastomer content is 29.5-30.1% by mass, and the silicone oil content is 1.6-1. The resin composition according to [1], which is 9% by mass.
[3] The polypropylene content is 52.3 mass%, the styrene elastomer content is 29.7 mass%, the silicone oil content is 1.8 mass%, and the barium sulfate content is 15. The resin composition according to [2], which is 0.8% by mass and the pigment content is 0.5% by mass.
[4] A medical tube forming material comprising the resin composition according to any one of [1] to [3].
[5] A medical tube using any one of [1] to [3].

  According to the present invention, it is possible to provide a resin composition, a medical tube forming material, and a medical tube that have both flexibility and slidability.

It is a schematic diagram explaining the measuring method of the dynamic friction coefficient in [Example]. It is a schematic diagram explaining the measuring method of the bending elastic modulus in [Example].

  The resin composition of the present invention comprises 50.6-60.3 mass% polypropylene, 19.6-33.7 mass% styrene elastomer, 1.6-4.5 mass% silicone oil, and barium sulfate 9 0.1 to 17.3 mass% and 0.3 to 0.6 mass% of pigment.

The polypropylene (hereinafter also referred to as PP) may be any of a homopolymer (homo PP), a random copolymer (random PP), and a block copolymer (block PP), and also has an atactic structure, syndiotactic. Any of the structures may be used.
As comonomer (monomer copolymerized with propylene) in random PP and block PP, ethylene, α-olefin having 4 or more carbon atoms (1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1) -Pentene, 1-hexene, 4-methyl-1-hexene, 1-heptene, 1-octene, 1-decene, etc.).
The PP contained in the resin composition may be one type or two or more types.
As PP, block PP is preferable.

  As the styrene-based elastomer, a styrene-based thermoplastic elastomer is preferably used. As the styrene-based thermoplastic elastomer, known ones can be used. For example, a block composed of a polymer of styrene monomers (styrene block) and a block composed of a polymer of conjugated diene (diene-based). And those in which the double bond of the diene block is hydrogenated (hydrogenated block copolymer).

In the hydrogenated block copolymer, examples of the styrene monomer include styrene, α-methylstyrene, p-methylstyrene, and dimethylstyrene. Examples of the conjugated diene include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and the like.
Specific examples of the hydrogenated block copolymer include a hydrogenated styrene-butadiene block copolymer, a hydrogenated styrene-isoprene block copolymer, and a hydrogenated styrene-isoprene-butadiene block copolymer.

In the hydrogenated block copolymer, the content of the structural unit based on the styrene monomer is preferably 5 to 50% by mass, more preferably 8 to 45% by mass, based on the total mass of the hydrogenated block copolymer. 10-40 mass% is further more preferable.
The hydrogenation rate of the double bond of the diene block is preferably 80% or more, more preferably 90% or more, and further preferably 95% or more.
The weight average molecular weight of the hydrogenated block copolymer is preferably from 50,000 to 500,000, more preferably from 60,000 to 400,000, more preferably from 70,000 to 300,000 as a value in terms of polystyrene measured by gel permeation chromatography. preferable.
The styrene elastomer contained in the resin composition may be one type or two or more types.

Known silicone oils can be used, and examples thereof include dimethyl silicone oil, methylphenyl silicone oil, and fluoroalkyl silicone oil.
The silicone oil contained in the resin composition may be one type or two or more types.

The silicone oil preferably has a kinematic viscosity of 1,000 to 1,000,000 mm ² / s. When the kinematic viscosity of silicone oil is 1000 mm ² / s or more, it is difficult to bleed to the surface, is not more than 1000000mm ² / s, is good dispersibility in the resin.

Barium sulfate is dispersed in the resin composition as solid particles.
As barium sulfate, a powdery one is usually used. The average particle diameter of barium sulfate is preferably 0.1 to 10 μm. When the average particle size is 0.1 μm or more, the dispersibility in the resin is good, and when it is 10 μm or less, the surface property of the resin is good.

The pigment is used for coloring the resin composition.
The pigment may be an inorganic pigment or an organic pigment, and can be appropriately selected from known pigments according to the color to be colored.
When the resin composition forms, for example, a tip portion of a pusher tube, a blue pigment is preferable as the pigment.
Preferred examples of blue pigments include C.I. I. (Color Index) PB (Pigment Blue) No. 74160, PB15: 1, PB15: 2, PB15: 3, PB15: 4, PB15: 5, PB15: 6, and the like.
Among these, the crystal transformation of PB15: 1 and PB15: 2 is the α phase, the crystal transformation of PB15: 3 and PB15: 4 is the β phase, and the crystal transformation of PB15: 6 is the ε phase. The phase stability is lowest in the α phase and highest in the β phase. Therefore, among the above, PB15: 3 and PB15: 4 are preferable.
1 type or 2 types or more may be sufficient as the pigment contained in a resin composition.

  In addition to the above, the resin composition of the present invention may further contain an inorganic material, an organic material additive, or the like as long as the effects of the present invention are not impaired.

In the resin composition of the present invention, the content of PP is 50.6 to 60.3% by mass, the content of styrenic elastomer is 19.6 to 33.7% by mass, and the content of silicone oil is 1.6 to The content of 4.5% by mass, barium sulfate is 9.1 to 17.3% by mass, and the content of pigment is 0.3 to 0.6% by mass.
The content (% by mass) of each component is a value when the total mass of the resin composition is 100% by mass.
Since the content of PP, styrene-based elastomer, silicone oil, and barium sulfate is within the above range, the resin composition can be used as a material for forming a medical tube (catheter, pusher tube, etc.) inserted into a living body. Appropriate flexibility and excellent slidability (for example, the flexural modulus measured by the measurement method shown in [Example] described later is within a range of 516 ± 114 MPa and the dynamic friction coefficient is 0.19 or less). . In addition, the processability of the resin composition is also good.

On the other hand, if the PP content exceeds 60.3% by mass or the styrene-based elastomer content is less than 19.6% by mass, flexibility may be insufficient. If the content of the styrene elastomer exceeds 33.7% by mass or the content of PP is less than 50.6% by mass, the flexibility may be too high.
If the silicone oil content is less than 1.6% by mass or the barium sulfate content is less than 9.1% by mass, the slidability and flexibility may be insufficient. If the silicone oil content exceeds 4.5 mass% or the barium sulfate content exceeds 17.3 mass%, the flexibility may be too high.
Furthermore, if the content of silicone oil exceeds 4.5% by mass, the processability of the resin composition may be reduced. For example, when molding a resin composition, silicone oil may be separated from the resin composition, which may cause a problem of bleeding that floats on the surface of a molded article such as a tube. When bleeding occurs, for example, when a tube using the resin composition is inserted into a channel tube or the like of an endoscope, there is a risk that silicone oil may migrate to the inner surface of the channel tube or the like. Cannot be used.
From the viewpoint of processability, the silicone oil content in the resin composition is preferably 2.1% by mass or less.

In the resin composition of the present invention, the PP content is 50.6-53.9% by mass, the styrene elastomer content is 29.5-30.1% by mass, and the silicone oil content is 1.6. It is preferable that it is -1.9 mass%. That is, the resin composition of the present invention comprises PP 50.6 to 53.9% by mass, styrene-based elastomer 29.5 to 30.1% by mass, silicone oil 1.6 to 1.9% by mass, and barium sulfate. It is preferable to contain 9.1-17.3 mass% and pigment 0.3-0.6 mass%.
When the content of PP, styrene-based elastomer, and silicone oil is within the above range, the operability of the medical tube inserted into the living body and the flexibility that contributes to the insertion property are more suitable (for example, described later [ The flexural modulus measured by the measuring method shown in the example] is in the range of 500 ± 25 MPa. Moreover, the workability of the resin composition is also improved.

In the resin composition of the present invention, the PP content is 52.3% by mass, the styrene elastomer content is 29.7% by mass, the silicone oil content is 1.8% by mass, and the barium sulfate content is Is preferably 15.8% by mass and the pigment content is preferably 0.5% by mass.
When the content of PP, styrene-based elastomer, silicone oil, and barium sulfate is within the above range, in addition to the effects such as more favorable flexibility and improved workability, medical treatment inserted into the living body The slidability contributing to the insertion property of the tube for use is more suitable (for example, the dynamic friction coefficient measured by the measurement method shown in [Example] described later is 0.12 or less).

The resin composition of the present invention can be produced by melt-kneading PP, a styrene elastomer, silicone oil, barium sulfate, a pigment, and optional components as necessary.
The melt kneading can be performed using a known kneading apparatus such as a single screw extruder or a twin screw extruder.
The melt-kneading is performed at a temperature equal to or higher than the melting point of the PP to be used (when a plurality of PPs are used, the melting point is equal to or higher than the melting point of the highest PP).
The kneading temperature is preferably less than the thermal decomposition temperature of the PP used (in the case of using a plurality of PPs, the kneading temperature is lower than the thermal decomposition temperature of the PP having the lowest thermal decomposition temperature).

Thus, the obtained resin composition is shape | molded by the shape according to a use.
The resin composition can be molded by a known molding method as a thermoplastic resin molding method, for example, extrusion molding, injection molding, compression molding, or the like.

The use of the resin composition of the present invention is not particularly limited, and for example, it can be used as a material for forming medical tubes, medical products and the like, and is particularly useful as a medical tube forming material.
The medical tube is preferably a medical tube that is inserted into a living body because both flexibility and slidability are required. Examples of such medical tubes include catheters and pusher tubes.

The resin composition of the present invention has a bending elastic modulus in the range of 516 ± 111 MPa in particular in the insertion direction (hereinafter also referred to as a tip), and is also referred to as another portion (hereinafter also referred to as a non-tip). ) Is suitable as a material for forming the tip portion of the pusher tube having a bending elastic modulus in the range of 855 ± 81 MPa.
The pusher tube is used to push the stent to the target site along the guide wire inserted into the living body through the channel tube of the endoscope when the stent is inserted into the target site in the living body. The channel tube of the endoscope is curved. If the tip of the pusher tube has a relatively high flexibility in the range of the flexural modulus of 516 ± 111 MPa, it is easy to pass the curved portion of the channel tube. Further, if the non-tip portion has a relatively low flexibility in the range of a bending elastic modulus of 855 ± 81 MPa, the force applied when the pusher tube is inserted is easily transmitted to the tip portion efficiently. Therefore, the insertability of the pusher tube is improved.
According to the resin composition of the present invention, a tubular member having a flexural modulus in the range of 516 ± 111 MPa can be formed, and the tubular member has a low surface frictional resistance and a high slidability. Therefore, a pusher tube having a tip formed of a tubular member formed from the resin composition of the present invention has high insertability into a channel tube. In addition, the operability of the guide wire inserted through the lumen is good.
Moreover, it is requested | required that the front-end | tip part of a pusher tube should be colored in order to recognize the change location of a softness | flexibility. The resin composition of the present invention is colored with a pigment, and in this respect also, it is useful as a material for forming the tip of the pusher tube.
The length of the tip of the pusher tube is preferably about 1 to 30 cm. The length of the non-tip portion is set according to the total length of the pusher tube. The total length of the pusher tube is usually about 100 to 300 cm.
Although it does not specifically limit as a material which forms a non-tip part, Polypropylene 75.4-77.7 mass% can be compatible with the softness | flexibility (or rigidity) suitable as a non-tip part, and favorable slidability. And a resin composition containing 5.2 to 6.1% by mass of a styrene-based elastomer, 1.8 to 1.9% by mass of silicone oil, and 15.2 to 16.7% by mass of barium sulfate.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.
The raw materials used in Examples and Comparative Examples are as follows.

<Raw materials>
Polypropylene: Product name “Novatec PP BC8”, manufactured by Nippon Polypro.
Styrene elastomer: Product name “Super Tribrene HD0900”, manufactured by Shinsei Kasei Co., Ltd.
Silicone oil: Product name “360MF kinematic viscosity 12500CS”, manufactured by Toray Dow Corning.
Barium sulfate: Product name “B-1 Average particle size 1 μm”, manufactured by Sakai Chemical Co., Ltd.
Pigment: Blue pigment (PB15: 3), manufactured by Sanchemi.

<Examples 1-7, Comparative Examples 1-10>
[Preparation of resin composition]
Polypropylene, styrene elastomer, silicone oil, barium sulfate, and pigment are blended so as to have the composition (unit: mass%) shown in Table 1, and melt kneaded with a twin screw extruder (φ30 mm). Thus, a pellet-shaped kneaded product (resin composition) was obtained. The melt-kneading was performed by changing the set temperature in the order of 80 ° C.-180 ° C.-220 ° C.-220 ° C. at a rotation speed of 200 rpm.
In Examples 1, 2, 5 and Comparative Examples 5, 7 to 10, the total content of each component is not 100.0% because the second decimal place is rounded off. The total of each component is 100.0%.

[Production of tube]
The obtained kneaded product was molded under the following conditions using a single screw extruder (φ20 mm) equipped with a tube die to obtain a tube.
(Molding condition)
Number of revolutions: 20 rpm.
Tube die cap dimensions: 5 mm outer diameter, 3 mm inner diameter.
Molding speed: 3 m / min.
Tube dimensions: 3 mm outer diameter, 2 mm inner diameter.

[Slidability evaluation]
A material was put in a 120 mm × 120 mm × 1 mm mold, and a sheet was formed by applying a 20 MPa load for 5 minutes by hot pressing at 200 ° C., and then cut into a width of 20 mm to obtain a test piece.
The dynamic friction coefficient of the surface of the obtained test piece was measured with reference to JIS K7125.
The procedure for measuring the dynamic friction coefficient will be described with reference to FIG. For the measurement, a test piece 1 is installed and movable in parallel with the installation surface; a reinforcing plate 3 for fixing the test piece 1 to the table 2; a mating member 4 placed on the test piece 1; A friction coefficient measuring device composed of a weight 5 for pressing the mating member 4 with a constant load against the test piece 1 and a load cell 6 connected to the mating material 4 was used. The test piece 1 is fixed to the table 2 and moves together with the table 2. The test piece 1 fixed to the table 2 is subjected to a vertical load by the weight 5 and comes into contact with the mating member 4. When the table 2 is translated in the direction opposite to the load cell 6 side (in the direction of the arrow in the figure), friction occurs on the contact surface between the test piece 1 and the counterpart material 4. The frictional force at this time is converted into a dynamic friction coefficient by the load cell 6. It shows that surface friction resistance is so small that this dynamic friction coefficient is small, and slidability is high.
In the measurement of the dynamic friction coefficient, the material of the mating material 4 is SUS, the size of the contact surface of the mating material 4 to the test piece 1 is 10 mm × 10 mm, the weight 5 (the load at the time of measurement) is 50 g, and the table 2 is moved. The speed was 100 mm / min.

From the above measurement results, the slidability was evaluated according to the following criteria. The results are shown in Tables 1-2.
(Criteria)
○: Dynamic friction coefficient is 0.19 or less.
X: Dynamic friction coefficient is more than 0.19.

[Evaluation of flexibility]
A material was put into a 120 mm × 120 mm × 2 mm mold, and a sheet was formed by applying a 20 MPa load for 5 minutes by hot pressing at 200 ° C., and then cut into a width of 20 mm to obtain a test piece.
As shown in FIG. 2, the test piece 7 is placed on a support base 8 so that both ends in the length direction are supported, and bending elasticity is applied by applying force F to the center of the test piece with an indenter from above the test piece. The rate was measured. The flexural modulus was measured according to JIS K7171 under the following measurement conditions.
Distance between fulcrums L: 20 mm.
Indenter tip radius R1: 2.0 mm.
The fulcrum tip radius R2: 2.5 mm.
Bending speed: 15 mm / min.

The flexibility was evaluated from the above measurement results according to the following criteria. The results are shown in Tables 1-2.
(Criteria)
○: The flexural modulus is within the range of 516 ± 114 MPa.
X: The bending elastic modulus is outside the range of 516 ± 114 MPa.

[Evaluation of workability]
A test piece of 20 mm × 20 mm × 1 mm obtained by cutting the sheet prepared above is sandwiched between papers, applied with a load of 100 g, left for 5 days, then visually observed for bleeding, and processed according to the following criteria. Sex was evaluated. The results are shown in Tables 1-2.
(Judgment criteria)
○: There was no bleed.
X: There was a bleed.

As shown in the above results, PP50.6-60.3 mass%, styrene-based elastomer 19.6-33.7 mass%, silicone oil 1.6-4.5 mass%, and barium sulfate 9.1-. The resin composition of Examples 1-7 containing 17.3 mass% and pigment 0.3-0.6 mass% had moderate softness | flexibility and high slidability.
In particular, the PP content is 50.6 to 53.9 mass%, the styrene elastomer content is 29.5 to 30.1 mass%, and the silicone oil content is 1.6 to 1.9 mass%. Certain Examples 2 to 6 had more preferable flexibility (bending elastic modulus in the range of 500 ± 25 MPa) and good workability.
On the other hand, Comparative Example 1 in which the silicone oil and barium sulfate were not blended and the blending amount of the styrene elastomer was large was low in sliding property. Comparative Example 2 in which the amount of barium sulfate was increased without adding silicone oil and the amount of PP was decreased was too high in flexibility. Comparative Example 3 in which the amount of the silicone oil was increased without adding barium sulfate was too flexible and further poor in processability. The comparative example 4 which increased the compounding quantity of PP was too low in flexibility. Comparative Example 5 in which the amount of styrene-based elastomer was increased, Comparative Example 6 in which the amount of barium sulfate was increased, and Comparative Example 7 in which the amount of PP was decreased were too flexible. Comparative Example 8 in which the blending amount of PP was increased and the blending amount of styrene-based elastomer was decreased was too low in flexibility. In Comparative Example 9 in which the blending amount of the barium sulfate and the silicone oil was decreased, the slidability was low. In Comparative Example 10 in which the blending amount of barium sulfate was reduced, the slidability was low and the flexibility was too low.

  1 test piece, 2 table, 3 reinforcing plate, 4 mating material, 5 weight, 6 load cell, 7 test piece, 8 support base, 9 indenter

Claims (5)

  50.6-60.3% by mass of polypropylene, 19.6-33.7% by mass of styrene elastomer, 1.6-4.5% by mass of silicone oil, 9.1-17.3% by mass of barium sulfate And a resin composition containing 0.3 to 0.6% by mass of pigment.   The polypropylene content is 50.6-53.9% by mass, the styrene elastomer content is 29.5-30.1% by mass, and the silicone oil content is 1.6-1.9% by mass. The resin composition according to claim 1, wherein   The polypropylene content is 52.3 mass%, the styrene elastomer content is 29.7 mass%, the silicone oil content is 1.8 mass%, and the barium sulfate content is 15.8 mass%. %, The resin composition according to claim 2, wherein the pigment content is 0.5 mass%.   The medical tube formation material which consists of a resin composition as described in any one of Claims 1-3.   The medical tube using the resin composition as described in any one of Claims 1-3.

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