JP2005318949A - Medical tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical tube excellent in infusion transportation at a low temperature. <P>SOLUTION: A thermoplastic resin composition (C) contains a thermoplastic resin (A) and a tackifier (B). The medical tube uses the thermoplastic resin composition (C) where the rate of contents of the tackifier (B) is 5 to 40 mass% and loss tangent (tan δ) at 25°C is ≥0.2. By blending of the tackifier (B), exfoliation resistance is improved. In particular, the tube is usable for sending of liquid by an infusion pump at low temperatures steadily for a long period of time. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a medical tube, and more particularly to a medical tube suitable for an infusion pump at a low temperature without being cured even at a low temperature.

  A medical tube made of soft polyvinyl chloride is often used because of its excellent mechanical strength and flexibility. However, when a drug such as nitroglycerin or diazepam is infused, there is a problem that these are adsorbed to the tube. In addition, some soft polyvinyl chlorides contain plasticizers such as DEHP (diethylhexyl phthalate) to give flexibility, and drugs containing surfactants as drug solubilizers, such as anticancer drugs In the case of infusion of pepsid, taxol, fat emulsion, anesthetic provophor, etc., the plasticizer is eluted from the tube, and the influence of the plasticizer on the living body and the hardening of the tube over time becomes a problem. In addition, materials containing halogen-based polymers such as polyvinyl chloride and chlorinated polyethylene are expected to generate non-halogen-based alternative materials in view of recent environmental problems, such as the fear of dioxin generation during incineration.

  In order to cope with these problems, a tube material made of an elastomer that does not contain a plasticizer (Patent Document 1) and a tube material made of polybutadiene that hardly absorbs a drug have been developed and used (Patent Document 2). However, these tube materials have poor kink resistance and strong resilience, that is, poor vibration damping, and therefore often poor in operability. For example, infusion tubes are often curved and secured to the body, or looped to secure safety and secured to the extremities, but if the resilience is strong, the tube will come off the fixture. Curves and loops may suddenly break and jump up. By this operation, the indwelling needle that secured the blood vessel may come off or the joint between the tubes may come off, leading to a medical accident. Accordingly, the medical tube is desired to be soft and low in resilience, but the tube made of a polyolefin material such as polybutadiene has a large resilience and may be inferior in operability.

  On the other hand, it has also been studied to respond to the above-mentioned problems by multilayering polyvinyl chloride and a polyolefin material. For example, a multilayer tube composed of two or more layers, which has a chlorinated polyethylene layer as an outer layer and a polyethylene resin layer as an inner layer is disclosed (Patent Document 3). This multi-layer tube has moderate flexibility without bending or bending when the tube is bent, and there is no change in shape or size even when sterilized. It has been developed as a multi-layer tube that can be bonded to a solvent, is excellent in transparency, flexibility, kink resistance, forceps resistance, heat resistance and has no plasticizer elution.

  Also disclosed is a three-layer tube using a vinyl chloride resin for the outer layer, a low density polyethylene for the inner layer, and an ethylene-vinyl acetic acid copolymer for the adhesive layer (Patent Document 4). Since low-density polyethylene is used for the inner layer, it is suitable for administration of nitroglycerin, insulin, etc., can be solvent-bonded, and is flexible and excellent in flexibility. Further, Patent Document 5 has a problem of delamination resistance of a structural layer as a specific requirement for a medical tube, and uses an ethylene-acrylic acid ester-maleic anhydride terpolymer as an adhesive layer for a multilayer tube or the like. A method is disclosed.

As a tube with reduced resilience, a thermoplastic material having a loss tangent (tan δ) at 25 ° C. of 0.4 or more and a thermoplastic polyolefin having a Young's modulus in the range of 50 to 600 kg / cm ² are coextruded. The tube obtained by this is disclosed (patent document 6). However, this tube assumes the use temperature from room temperature to body temperature, and is molded using the styrene / isoprene / styrene triblock copolymer (Hibler 5127 manufactured by Kuraray Co., Ltd.) exemplified in the examples and the material as a material. The tube has a Young's modulus of 800 kg / cm ² or more in a low temperature environment of 5 to 10 ° C. and becomes extremely hard. Therefore, the tube is used as a medical tube for feeding a medical solution into the body using an infusion pump or the like. May be difficult to use at low temperatures.
JP 2003-205033 A JP-A-6-184360 JP 2002-282369 A US Pat. No. 4,627,844 JP-A-8-300575 JP 2003-102827 A

  Conventional medical tubes can prevent the absorption of drugs by technologies such as using polyethylene resin for the inner layer, and the introduction of a specific adhesive layer improves the peel resistance after heat sterilization, and the feeding of chemical solutions and extension tubes It can be used as

  However, as a mode of use of the infusion tube, there are cases where the roller pump or the peristaltic pump for injecting the drug solution into the body is used to circulate blood in the circuit during extracorporeal circulation. It may not be suitable for the mode when the pump is used. Specifically, infusion pumps and blood pumps are generally delivered by a peristaltic finger method or roller method, but the outer surface of the tube is squeezed when such chemicals or blood is delivered, so that the tube is damaged. Sometimes it was torn when scraped. In other words, as a characteristic of such a pump tube, durability as well as flexibility is required, but conventional multilayer tubes are separated between two layers by squeezing with a roller pump or a peristaltic pump. There was a problem in terms of durability and safety.

  In addition, conventional non-halogen-based medical multilayer tubes are made of a polyolefin-based material such as polybutadiene or polyethylene, or a styrene-based elastomer material, and may be inferior in operability. In order to improve operability, a method of reducing the resilience by combining a thermoplastic resin having a loss tangent (tan δ) at 25 ° C. of 0.4 or more has been proposed. In order to obtain it, it is necessary to have suitable physical properties suitable for the safety mechanism of the infusion pump at 10 to 40 ° C., preferably 5 to 40 ° C. In this regard, the resin composition used in the conventional medical tube may be hardened at 5 to 10 ° C. because the glass transition point is in the room temperature range. Further, the infusion pump secures safety by a mechanism that detects the pressure of a tube connected to the pump and stops the infusion for an abnormal value. Conventionally, the upper and lower pressure limits have been set based on polyvinyl chloride resin. However, if the tube is too flexible, the detection sensitivity becomes unnecessarily high. Safety cannot be ensured. Usually, since an infusion pump is used at 5-40 degreeC, it is calculated | required to have a softness | flexibility suitable for the detection sensitivity of an infusion pump in this temperature range.

  Therefore, the present invention has no absorption of chemicals, does not dissolve plasticizers, has heat resistance that can withstand sterilization, and is resistant to peeling even when used with an infusion pump that squeezes the tube and feeds it. It aims at providing the medical tube which is excellent in.

  It is another object of the present invention to provide a medical tube having an initial elastic modulus that can be applied to a tube pressure detection mechanism of an infusion system, and the physical properties of the obtained multilayer tube are close to polyvinyl chloride.

  This inventor is a resin composition containing a thermoplastic resin (A) and a tackifier (B), wherein the content of the tackifier (B) is 5 to 40% by mass, and at 25 ° C. When a medical tube is produced using the thermoplastic resin composition (C) having a loss tangent (tan δ) of 0.2 or more, there is no elution of the plasticizer, and a medical tube excellent in kink resistance is obtained. When the thermoplastic resin (A) has a loss tangent (tan δ) at 25 ° C. of less than 0.2 and is a thermoplastic polyolefin containing propylene or ethylene, a medical tube connected to an infusion pump used at a low temperature The present invention has been completed by finding that it can be suitably used with moderate flexibility.

  Since the medical tube of the present invention uses a flexible thermoplastic resin composition even at a low temperature, it can be suitably used at a low temperature as a medical tube connected to an infusion pump. When the composition is used as an intermediate layer of a multi-layer medical tube, it has excellent adhesion to other layers and can maintain transparency, so that it can provide resistance to peeling over time and extend the tube life. Can do.

  The medical tube of the present invention is particularly excellent in flexibility, transparency, mechanical properties, etc., without absorption of a chemical solution when a polyolefin layer is disposed as an inner layer.

  The medical tube of the present invention can appropriately respond to a risk detection mechanism such as an infusion pump, and can be used as an infusion tube with high safety.

  1st of this invention is a thermoplastic resin composition (C) containing a thermoplastic resin (A) and a tackifier (B), and the content rate of the said tackifier (B) is 5-40 mass%. And a medical tube using the thermoplastic resin composition (C) having a loss tangent (tan δ) at 25 ° C. of 0.2 or more. The medical tube of the present invention may be composed only of the thermoplastic resin composition (C), and the thermoplastic resin composition (C) may be used as any layer of a multilayer medical tube. Good. Moreover, although a layer is not comprised, it is arrange | positioned as a some linear structure connected in the longitudinal direction of a medical tube, and you may ensure damping property by this.

  The thermoplastic composition (C) preferably has a loss tangent (tan δ) at 25 ° C. of 0.2 or more, preferably 0.25 to 1.0, more preferably 0.3 to 0.6. When the loss tangent is less than 0.2, the resilience increases, and the operability as a medical tube may decrease. The loss tangent is a type of viscoelastic parameter that quantitatively represents viscoelasticity. When a sinusoidal stress is applied to a polymer material, the strain becomes a sinusoidal waveform with the same frequency and the phase delayed by δ. Tangent can be calculated.

  When the loss tangent at 25 ° C. of the thermoplastic resin composition (C) is 0.2 or more, vibration damping is ensured, and it can be suitably used, for example, as an extension tube for low-temperature infusion. Moreover, although it is suitable also as a multilayer medical tube of 2 layers or more, when using for the medical tube of 3 layers or more of multilayers, it is good to arrange | position as an intermediate | middle layer especially. It is because it is excellent in adhesiveness and excellent in adhesion with other layers, and can effectively prevent peeling. From this point of view, even when the layer is not configured, for example, a linear structure may be formed by the resin composition, and the linear structure may be embedded in the medical tube.

  The thermoplastic composition (C) includes a thermoplastic resin (A) and a tackifier (B). The thermoplastic resin (A) is not particularly limited as long as it satisfies the properties of the thermoplastic composition (C) in a state where the tackifier (B) and the like are blended, but contains a halogen element such as chlorine. It is preferable that the resin is substantially transparent. This is because it is preferably used for medical purposes, and it is preferable that the liquid and bubbles moving in the tube can be visually recognized.

The tackifier (B) may generally be a material having an average molecular weight of 400 to 10,000 and called a tackifier, and is preferably an α-olefin polymer such as polybutene or a copolymer thereof, or isoprene rule. A terpene resin such as terpene or a derivative thereof, which is a general term for a series of compounds based on ((C ₅ H ₈ ) _n ), is preferable. Terpenes include monoterpenes (C ₅ H ₈ ) ₂ ) such as α-pinene, β-pinene, and limonene, sesquiterpenes such as longifolene (C ₅ H ₈ ) ₃ ), rosin (C ₅ H ₈ ) ₄ ), and the like. Diterpenes, carotene, IR, and natural terpenes such as natural rubber (C ₅ H ₈ ) _n ). Among these terpenes and derivatives thereof, terpene resins preferably used in the present invention include terpene resins having a softening point temperature of 80 to 130 ° C. and a molecular weight of 600 to 3,000. Examples of such terpene resins include trade names “YS Resin D105” and “YS Resin PX1000” manufactured by Yasuhara Chemical Co., Ltd. Other terpene resins include aromatic modified terpene resins containing phenyl, benzyl and derivatives thereof (commercially available from Yasuhara Chemical Co., Ltd., trade names “YS Resin TO105”, “YS Resin TR105”, etc.), hydrogen Hydrogenated terpene resin containing an added terpene unit (trade names “Chroalon P125”, “Chroalon P115”, “Chroalon P105”, “Croalon M115”, “Croalon M105”, “Croalon K110” as commercial products manufactured by Yashara Chemical Co., Ltd. ”,“ Chroalon K100 ”, etc.), a terpene phenol resin containing a hydroxyphenyl group or a derivative thereof (commercially available from Yasuhara Chemical Co., Ltd., trade names“ YS Polystar U1115 ”,“ YS Polystar 2130 ”,“ YS Polystar 210 ”) "," YS Polystar T130 "," YS Polystar T115 "," Mighty Ace G125 ", there is a" YS Polystar TH130 ", etc.).

  When the aromatic modified terpene resin is used, there is little thermal discoloration, the rebound resilience of the thermoplastic resin (A) can be suppressed, and viscoelastic behavior close to that of a soft vinyl chloride resin can be exhibited. In addition, the hydrogenated terpene resin has a colorless and transparent hue when hydrogenated, and has excellent heat stability.

  The said tackifier is 5-40 mass% in a thermoplastic resin composition (C), More preferably, it is 10-35 mass%. If the amount is less than 5% by mass, the resilience may be inferior. On the other hand, if it exceeds 40% by mass, the tackiness may be excessively increased.

  The thermoplastic resin (A) used in the present invention is a resin having a loss tangent (tan δ) of 0.2 or more at room temperature with a tackifier added. Ethylene which is a thermoplastic polyolefin containing propylene and / or ethylene, which is mainly composed of ethylene (C2) or propylene (C3), and copolymerized with butene (C4), hexene (C6), octene (C8), etc. Propylene copolymer, ethylene / butene copolymer, 1-butene / propylene copolymer, propylene / butene / ethylene copolymer, ethylene / hexene copolymer, ethylene / octene copolymer, or a mixture thereof Can be illustrated. Furthermore, a styrene / isoprene / styrene (SIS) triblock copolymer (Kuraray Co., Ltd., Hibler 5127) having 3,4-bonded polyisoprene as a block, and hydrogenated products (Kuraray Co., Ltd., It is also possible to use HIBLER 7125). Note that the loss tangent (tan δ) at 25 ° C. is preferably 0.03 or more from the viewpoint of easy control of the loss tangent (tan δ). Examples of the tackifier (B) to be blended in the resin (A) having a loss tangent (tan δ) of 0.2 or more at room temperature include α-olefin polymers such as polybutene. These are effective for suppressing curing at low temperatures.

  On the other hand, the thermoplastic resin (A) has its own loss tangent (tan δ) at 25 ° C. of less than 0.2, but the thermoplastic resin composition (C) can be mixed with the tackifier (B). The loss tangent can be controlled to 0.2 or more. In particular, the loss tangent of the thermoplastic resin (A) is less than 0.2, preferably 0.03 to 0.2, more preferably 0.05 to 0.15 in that the Young's modulus at a low temperature can be controlled. There may be. As the resin (A) having a loss tangent of less than 0.2, there is a resin in which polypropylene or ethylene / octene copolymer is blended with amorphous polypropylene such as propylene / butene copolymer. A resin blended with polypropylene or an ethylene / octene copolymer is preferable from the viewpoint of excellent transparency. As the tackifier (B) to be blended with the resin (A) having a loss tangent (tan δ) of less than 0.2 at room temperature, among the above, there is a terpene resin. This effectively works to improve loss tangent at room temperature.

  The thermoplastic resin (A) is preferably 60 to 95% by mass, more preferably 65 to 90% by mass in the thermoplastic resin composition (C). In the case of SIS that is generally used from the past, it was necessary to blend a large amount of soft resin in order to improve temperature characteristics, but there are few resins that can be blended without impairing transparency. However, in the present invention, polybutadiene having excellent transparency is used, and by adding a tackifier thereto, low resilience at low temperatures can be ensured. Polybutadiene can be blended with other resins while maintaining a certain degree of transparency. However, polybutadiene has a double bond in the molecule and easily crosslinks during molding, thus impairing stable long-term tube molding. There is a case. From this point, it is preferable that the addition amount of polybutadiene in the thermoplastic resin (A) is 50 parts by mass or less. Even in this case, the temperature characteristics corresponding to the use can be secured by adjusting the loss tangent of the thermoplastic resin composition (C) to the above range by the addition of the tackifier (B).

  The thermoplastic resin composition (C) used in the present invention has a Young's modulus at 5 to 40 ° C. of 3 to 50 MPa, more preferably 5 to 30 MPa, and particularly 5 to 20 MPa. This is because, within this range, it is possible to match the pressure detection mechanism of a general infusion pump and perform safe infusion. In addition, in the thermoplastic resin composition (C) used in the present invention, other resins, fillers, stabilizers, etc. are used in order to adjust the thermal hardness and strength within the range not impairing the above-described properties and transparency. May be blended.

  The medical tube of the present invention may be a single-layer tube composed of only the thermoplastic resin composition (C) as described above, but may be composed of two or more layers. In particular, when the thermoplastic resin composition (C) is used as an intermediate layer of a tube when it is composed of three layers consisting of an inner layer, an intermediate layer and an outer layer, the inner layer is a polyolefin resin mainly composed of ethylene or propylene. It is preferable to comprise in the layer which consists of. In addition, it is good also as a multilayer tube of four or more layers by adding the layer which gave the modification on physical property, gas barrier property, light-shielding property, etc.

  In the medical tube of the present invention, adsorption of a drug such as nitroglycene can be prevented if the inner layer is a polyolefin resin mainly composed of ethylene or propylene. In addition, polyolefins mainly composed of ethylene or propylene are inexpensive and can be particularly suitably used because they are fused with polyethylene or polypropylene connectors. In addition, the thermoplastic resin (A) mix | blended with the said thermoplastic resin composition (C) used for an intermediate | middle layer is also a polyolefin, and this thermoplastic resin (A) can also be used as an inner layer resin. Therefore, the copolymer of ethylene (C2) or propylene (C3) as mentioned above, butene (C4), hexene (C6), octene (C8), etc., and polyethylene alone, polypropylene alone, and the above-mentioned copolymer. A mixture of the polymer and polyethylene or polypropylene can be preferably used.

  More preferably, the inner layer is a resin having a Young's modulus of 20 to 100 MPa at a temperature of 25 ° C., and more preferably 25 to 60 MPa. If the Young's modulus is less than 20 MPa, blocking may occur when the tube is clamped with an insert or the like. When other additives are added to prevent such blocking, or when a lubricant is coated, the manufacturing process becomes complicated, and safety issues such as lubricant elution and peeling occur. There is. Therefore, the Young's modulus at 25 ° C. is preferably 20 MPa. If the Young's modulus exceeds 100 MPa, it is too hard when molded into a multilayer tube, and it is disadvantageous in terms of kink resistance.

  The tube may be blended with process oil or the like as long as the drug is not absorbed during infusion. Although it does not specifically limit as process oil used by this invention, Usually, a liquid or liquid material is suitably used at room temperature. Specific examples include process oils for various rubbers or resins such as mineral oils, vegetable oils, animals, and synthetics. Mineral oils include naphthenic and paraffinic process oils, and vegetable oils include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, palm oil, peanut oil, wax, pine Examples of oils and olive oils include squalene as animal systems, and polybutene and low molecular weight polybutadiene as synthetic systems. Among these, liquid paraffin and squalene are preferably used from the viewpoint of compatibility and physical property balance. These can be used in combination of two or more kinds in order to obtain desired physical properties. Such a polyolefin tube is suitable for a medical tube because it has characteristics such as low resilience, high flexibility, and low absorption of a chemical solution.

  In the multi-layer medical tube, the outer layer is preferably a layer made of a flexible polyolefin resin having an elastic recovery rate of 100% or more after elongation of 75% or more, more preferably 80% or more, and particularly 85% or more. When the elastic recovery rate is less than 75%, the amount of plastic deformation becomes large, and the stability with time of the liquid flow rate in the infusion pump may be lowered.

  Such resin is selected from ethylene (C2) or propylene (C3) as a main component, butene (C4), hexene (C6), octene (C8), styrene, a copolymer with cyclic olefins, and the like. A soft resin having a Young's modulus of 5 to 20 MPa at a temperature of 25 ° C. Such outer layer resins include propylene / butene copolymer tuftselenium (manufactured by Sumitomo Chemical Co., Ltd.), ethylene octene copolymer engagement (manufactured by DuPont Dow Elastomer Co., Ltd.), Moatech (manufactured by Idemitsu Co., Ltd.). Examples thereof include an index that is an ethylene / styrene copolymer (manufactured by Dow Chemical Co., Ltd.), an ethylene / norbornene copolymer, and the like.

  A cross-sectional view of the medical tube in the present invention will be described with reference to FIG. 1, but in the medical tube of the present invention, the ratio of the cross-sectional area of each layer is not limited. However, it is preferable that the inner layer is 5 to 15%, the middle layer is 15 to 50%, and the outer layer is 35 to 80% in terms of cross-sectional area. When the cross-sectional area conversion of the inner layer is less than 5%, the effect of preventing drug absorption by the polyolefin resin may be reduced. Furthermore, if the cross-sectional area conversion of the intermediate layer is less than 15%, the peel resistance and vibration damping properties may be reduced. At this time, the inner diameter is 0.5 to 6.0 mm and the outer diameter is 1.0 to 10 mm, preferably the inner diameter is 2.0 to 4.0 mm and the outer diameter is 3.0 to 6.0 mm. Further, it is preferable that the kink resistance is superior to the engagement E8100, which is an ethylene / octene copolymer and has an appropriate Young's modulus, and the maximum angle restoration amount is 95 to 105%.

  The inner layer, the intermediate layer, and the outer layer may contain additives such as an antioxidant, an ultraviolet absorber, a lubricant, and an antiblocking agent as long as the characteristics are not impaired. Specifically, antioxidants, heat stabilizers, light stabilizers, UV absorbers, neutralizers, lubricants, antifogging agents, slip agents, crosslinking agents, crosslinking aids, colorants, flame retardants, dispersants, Various additives such as an antistatic agent can be added.

  The medical tube of the present invention can be molded according to a known molding method such as extrusion molding, injection molding, blow molding, rotational molding, and the like by melt-mixing the above three types of resins. There is no limitation on the inner diameter, outer diameter, length, etc. of the medical tube, and it may be appropriately selected according to use.

  The multilayer tube preferably has a tensile strength of 5 MPa or more, more preferably 7 MPa or more, and an initial elastic modulus of 3 to 20 MPa, more preferably 4 to 15 MPa, depending on the configuration. If the tensile strength is 5 MPa or less, it may burst due to the pressure during infusion. On the other hand, when the initial elastic modulus exceeds 20 MPa, the tube becomes hard and may not be compatible with a pressure sensor of a commercially available infusion pump. The above range is the performance retained by the conventional vinyl chloride resin tube, and it is preferably used for any of the applications of the conventional vinyl chloride resin tube by maintaining the above characteristics even when it is a multi-layer tube. can do.

  On the other hand, in the medical tube of the present invention, the thermoplastic resin composition (C) is linearly disposed in the longitudinal direction of the tube, and an olefin resin is disposed on the outer periphery of the linear object. Also good. A cross section of such a medical tube is shown in FIG. A linear object made of the thermoplastic resin composition (C) is present in a ring shape in the tube, and a polyolefin resin surrounds the outer periphery thereof. In the present invention, as the polyolefin resin surrounding the linear material, the soft polyolefin resin used in the outer layer of the above-mentioned three-layered medical tube having a multilayer structure can be preferably used. Since polyolefin resin has little chemical solution adsorption and sorption, it is particularly suitable for inner and outer layers having a high contact rate with the chemical solution. In addition, the mixture ratio of the said linear thing is 10-60% of a linear thing in conversion of cross-sectional area, More preferably, it is 15-50%. Within this range, the linear material may be divided into 4 to 10 pieces, and a soft polyolefin resin may be disposed on the outer periphery thereof. At this time, the medical tube has an inner diameter of 0.5 to 6.0 mm and an outer diameter of 1.0 to 10 mm, preferably an inner diameter of 2.0 to 4.0 mm and an outer diameter of 3.0 to 6.0 mm. It is.

  The medical tube of the present invention includes an infusion set tube, an extension tube, a drug administration tube, a blood circuit tube, a winged venous needle tube, a suction catheter, a drainage catheter, an enteral feeding catheter, a stomach It can also be suitably used as a tube catheter, an angiographic catheter, a vasodilator catheter, a drug solution administration catheter, and the like.

  EXAMPLES Next, although an Example is given and this invention is demonstrated concretely, these Examples do not restrict | limit this invention at all. In addition, the tube of the Example and the comparative example was evaluated with the following method.

(1) Measurement of Young's modulus (initial elastic modulus) at room temperature Using a tensile tester (manufactured by Toyo Seiki Seisakusho), the initial elastic modulus was measured at room temperature (23 ° C. to 27 ° C.) at a tensile speed of 100 mm / min.

(2) Measurement of tensile strength Tensile strength was measured at room temperature and a tensile speed of 200 mm / min using the same tensile tester as in (1) above.

(3) Measurement of elastic recovery rate Using the same tensile tester as in (1) above, the elongation was measured by stretching 100% at room temperature and a tensile speed of 50 mm / min and returning to the origin. The recovery rate was calculated according to the following formula.

(4) Measurement of pressure detection of infusion pump A tube filled with water was installed in an infusion pump (Terumo Corporation TE-112, TE-161), and a pressure gauge was connected to the tip of the discharge side of the tube. The pump was operated at a flow rate of 100 ml / min, and the pressure when the pump stopped due to a clogging alarm was measured to confirm whether it was within the standard value.

(5) Confirmation of tube condition by continuous operation of infusion pump Install a tube filled with water in the infusion pump (TE-112, TE-161 manufactured by Terumo Corporation) and perform continuous operation at a flow rate of 25 ml / min for 24 hours. The tube state after the lapse was confirmed visually.

(6) Measurement of temperature dependence of loss tangent and Young's modulus Using a dynamic viscoelasticity measuring device (manufactured by IT Measurement Control Co., Ltd.), by a temperature rising method, a frequency of 10 Hz and a temperature rising rate of 5 ° C. / The measurement was performed under the condition of minutes, and the temperature dependence of the loss tangent (tan δ) was obtained. For the temperature characteristic of Young's modulus, the value of storage elastic modulus (E ′) was substituted.

(7) Measurement of maximum angle restoration amount First, the tube 1 as a sample is fixed in the vertical direction at two points a and b, and the tip 40 mm is a free end (FIG. 3a). Next, stress is applied immediately above the fixed portion b, and the tube 1 is pushed and bent in the direction of 90 degrees (FIG. 3b). Thereafter, when the stress is removed at once, the tube 1 finally returns to the original position (FIG. 3a), but the maximum angular displacement amount in this process is set to θ (FIG. 3c), and the maximum angle restoration amount is set to (θ / 90) × 100 (%). The angle θ can be easily measured by monitoring with a video camera or the like.

(8) Kink resistance Holds both ends of a tube cut to a length of 7 cm, observes R and resilience, etc. that cause kinks when bent slowly, and has a polybutadiene (trade name RB810) level or higher. It was judged as excellent as ◯. It is assumed that the level is less than that of polybutadiene, soft polyethylene (manufactured by Dow Elastomer Japan Co., Ltd., trade name Engage E8180), polyvinyl acetate (Tosoh Corporation, trade name of Ultrasen 750), and the like.

Example 1
As thermoplastic resin (A), 25 parts by mass of amorphous polypropylene (manufactured by Sumitomo Chemical Co., Ltd., trade name Tough Selenium X2135), ethylene / octene copolymer (DuPont Dow Elastomer Co., Ltd., trade name Engagement) 8100) 50 parts by mass, mixed resin blended with 25 parts by mass of hydrogenated terpene resin (trade name Clearon P105, manufactured by Yashara Chemical Co., Ltd.) as a tackifier (B), and using an extruder, an inner diameter of 2.1 mm A three-layer tube having an outer diameter of 3.4 mm was produced. This tube was excellent in vibration damping properties and kink resistance and had good temperature characteristics.

(Examples 2 to 5)
A tube having an inner diameter of 2.1 mm and an outer diameter of 3.4 mm was produced in the same manner as in Example 1 with the resin composition shown in Table 1. These tubes were excellent in vibration damping properties and kink resistance and had good temperature characteristics.

(Example 6)
As a thermoplastic resin (A), 80 parts by mass of an amorphous polyolefin resin (manufactured by Sumitomo Chemical Co., Ltd., trade name Tough Selenium X2135) containing propylene as a main component and a hydrogenated terpene resin (Yasuhara Chemical Co., Ltd.) as a tackifier (B) A thermoplastic resin composition (C) blended with 20 parts by mass of a product made by the company, trade name Clearon P105) is formed in the middle layer, and the inner layer is an ethylene / α-olefin copolymer (manufactured by Sumitomo Chemical Co., Ltd., trade name EXCELEN CX3005, Young's modulus 47 MPa. ), Using an ethylene / α-olefin copolymer (trade name Excellen CX4002, Young's modulus 21 MPa, manufactured by Sumitomo Chemical Co., Ltd.) for the outer layer, and using a three-layer extruder, the inner layer thickness is about 70 μm, the middle layer thickness is about 200 μm, the outer layer A three-layer tube having a thickness of about 380 μm, an inner diameter of 2.1 mm, and an outer diameter of 3.4 mm was produced.

  This tube had vibration damping properties and good temperature characteristics, but its kink resistance was slightly inferior compared to Examples 7 and 8 and the like.

(Examples 7 to 12)
A tube having an inner diameter of 3.1 mm and an outer diameter of 4.5 mm was produced in the same manner as in Example 6 with the resin composition shown in Table 2. These tubes were excellent in vibration damping properties and kink resistance and had good temperature characteristics.

(Example 13)
As a thermoplastic resin (A), 80 parts by mass of amorphous polypropylene (manufactured by Sumitomo Chemical Co., Ltd., trade name Tough Selenium X2135) containing propylene as a main component, and a terpene resin (manufactured by Yasuhara Chemical Co., Ltd.) as a tackifier (B), (Product name Clearon P105) The thermoplastic resin composition (C) blended with 20 parts by mass enters 8 lines, and the outer side is surrounded by an ethylene / octene copolymer (engage 8100, manufactured by DuPont Dow Elastomer Co., Ltd.). Co-extrusion was performed to produce a tube having a thermoplastic resin composition (C) occupying about 45% of the cross-sectional area, an inner diameter of 2.1 mm, and an outer diameter of 3.4 mm. This tube was excellent in vibration damping properties and kink resistance, and had good temperature characteristics.

(Examples 14 to 16)
A tube having an inner diameter of 2.1 mm and an outer diameter of 3.4 mm was produced in the same manner as in Example 13 with the resin composition shown in Table 5. These tubes were excellent in vibration damping properties and kink resistance and had good temperature characteristics. However, the tube of Example 15 was slightly inferior in kink resistance.

(Comparative Examples 1-6)
A tube having an inner diameter of 2.1 mm and an outer diameter of 3.4 mm was produced in the same manner as in Example 1 with the resin composition shown in Table 1. The tubes of Comparative Examples 1, 2, 3, and 6 had poor vibration damping properties (maximum angle restoration amount, tan δ), and the tubes of Comparative Examples 4 and 5 had low Young's modulus at low temperatures and poor temperature characteristics.

(Comparative Examples 7-15)
A tube having an inner diameter of 3.1 mm and an outer diameter of 4.5 mm was produced in the same manner as in Example 6 with the resin composition shown in Table 3. The tubes of Comparative Examples 7, 8, and 10-13 had poor vibration damping properties (maximum angle restoration amount, tan δ), and the tubes of Comparative Examples 9, 14, and 15 had low Young's modulus at low temperatures and poor temperature characteristics.

(Comparative Examples 16 and 17)
With the resin composition shown in Table 5, a tube having an inner diameter of 2.1 mm and an outer diameter of 3.4 mm was produced in the same manner as in Example 11. The tube of Comparative Example 16 had poor vibration damping (maximum angle restoration amount, tan δ), and the tube of Comparative Example 17 had a poor Young's modulus at low temperatures and poor temperature characteristics.

  The medical tube of the present invention is excellent in transparency, flexibility, and peel resistance, and can be suitably used for liquid feeding by an infusion pump at a low temperature, and is useful.

FIG. 1 is a cross-sectional view of the medical tube of the present invention. FIG. 2 is a cross-sectional view of the medical tube of the present invention. 3a to 3c show the measurement method of the maximum angle restoration amount in the present invention.

Explanation of symbols

1 ... Inner layer: Polyolefin layer,
2 ... Intermediate layer: ethylene vinyl acetate copolymer layer containing 10 to 80% of tackifier,
3 ... Outer layer: Soft polyvinyl chloride resin layer 10 ... Tube used as a sample.

Claims (6)

  It is a thermoplastic resin composition (C) containing a thermoplastic resin (A) and a tackifier (B), the content of the tackifier (B) is 5 to 40% by mass, and a loss at 25 ° C. A medical tube using a thermoplastic resin composition (C) having a tangent (tan δ) of 0.2 or more.   The medical tube according to claim 1, wherein the thermoplastic resin (A) is made of a thermoplastic polyolefin containing propylene or ethylene and has a loss tangent (tan δ) at 25 ° C of less than 0.2.   The medical tube according to claim 1 or 2, wherein the thermoplastic resin composition (C) has a Young's modulus at 25 ° C of 3 to 30 MPa.   The medical tube according to any one of claims 1 to 3, wherein the tackifier (B) is a terpene resin.   The thermoplastic resin composition (C) is used for the intermediate layer of a three-layer tube composed of an inner layer, an intermediate layer, and an outer layer, and the inner layer is a layer made of a polyolefin resin containing ethylene or propylene as a main component. The medical tube in any one of Claims 1-4.   The medical tube according to claim 5, wherein the outer layer is a layer made of a soft polyolefin resin having an elastic recovery rate of 75% or more.

Images