JPH0730219B2 - Resin composition for medical devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to 4-methyl-1-pentene suitable for medical devices.
The present invention relates to a resin composition mainly composed of an α-olefin random copolymer.

[Conventional technology]

Poly 4-methyl-1-pentene has its transparency, heat resistance,
Taking advantage of chemical resistance, beakers, measuring instruments such as graduated cylinders, syringes for syringes, optical measurement cells,
It is used for baking cartons by coating it on a microwave tray or paper. However, poly-4-methyl-1-pentene has a high melting point and good heat resistance, but on the other hand, lacks flexibility, so that its use was limited to fields requiring flexibility such as blood backing and tubes. .

On the other hand, as a thermoplastic resin excellent in flexibility and transparency, polyvinyl chloride (PVC) containing a plasticizer, so-called soft P
Although VC is known, such a resin has a drawback that it causes blocking of film, sheet, etc. due to bleeding of a plasticizer, and particularly in the case of medical equipment, it may require autoclaving in the manufacturing process. In many cases, under such treatment, bleeding of the plasticizer is more severe, blocking may be further promoted, and the bleeding plasticizer may be eluted into the drug solution, etc. I got it.

[Problems to be solved by the invention]

In view of such a situation, the present inventor did not include a large amount of a plasticizer, was flexible, and had various studies in order to develop a thermoplastic resin suitable for a medical device having excellent heat resistance and transparency,
Specific 4-methyl-1-pentene and α having 4 to 7 carbon atoms
-Finding that the composition based on a random copolymer with olefin has suitable properties for such applications,
The present invention has been completed.

[Means for solving problems]

That is, the present invention provides (a) 4-methyl-1-pentene content of 40 to 80 mol%, melting point of 140 to 220 ° C, and softening point of 90 to 190 ° C.
And crystallinity by X-ray is in the range of 15 to 35% 4
-Methyl-1-pentene and a carbon number of 4 to 7 (however, 4
(Excluding methyl-1-pentene) and a random copolymer (A) with α-olefin (A) more than 80% by weight and 100% by weight or less, (b) a homopolymer of 4-methyl-1-pentene or 4 A copolymer (B) of 4-methyl-1-pentene containing 85-mol% or more of -methyl-1-pentene and α-olefin having 2 to 20 carbon atoms (hereinafter referred to as "poly-4-methyl-1-pentene ( The present invention provides a resin composition for medical devices, which is characterized in that it is B)) 0 to less than 20% by weight, is excellent in flexibility and transparency, and has heat resistance capable of being subjected to autoclaving. .

[Work]

Poly-4-methyl-1-pentene, which is the main component of the resin composition for medical devices of the present invention (hereinafter sometimes abbreviated as composition)
α-olefin random copolymer (A) (hereinafter sometimes abbreviated as random copolymer (A)) means 4-methyl-
1-Pentene content is 40 to 80 mol%, preferably 50
To 75 mol%, melting point 140 to 220 ° C., preferably 16
0 to 210 ° C, softening point 90 to 190 ° C, preferably 110
4-Methyl-, whose degree of crystallinity by X-rays is from 15 to 35% by moles, preferably from 20 to 30%.
1-Pentene and 4 to 7 carbon atoms (provided that 4-methyl-
(Excluding 1-pentene) and a random copolymer with α-olefin, usually having an intrinsic viscosity [η] at 135 ° C. in a decalin solvent of 0.5 to 6 dl / g, preferably 1 to 5 dl / g.

A copolymer having a 4-methyl-1-pentene content of less than 40 mol% has low heat resistance and mechanical strength of the composition, and also has poor transparency. On the other hand, when it exceeds 80 mol%, the copolymer is inferior in flexibility and heat sealability. 4-methyl-1- in the present invention
The pentene content is a value measured by ¹³ C-NMR method.

A copolymer having a melting point of less than 140 ° C has poor heat resistance of the composition,
On the other hand, if the temperature exceeds 220 ° C, the flexibility and heat sealability are poor. The melting point in the present invention is the differential scanning calorimeter (DS
C), a sample of 10 mmg was taken from a press sheet with a thickness of 0.1 mm after 20 hours from molding, and the heating curve was measured from 0 to 250 ° C at a heating rate of 10 ° C / min, and the maximum endothermic peak Was taken as the melting point (Tm).

A copolymer having a softening point of less than 90 ° C has poor heat resistance, while
If the temperature exceeds 0 ° C, the heat sealability is poor. The softening point in the present invention, using a thermal mechanical analyzer (TMA), a 1 cm square sample is taken from a 1 mm-thick press sheet after 20 hours from molding, and a 0.025 inch diameter needle is placed on one side of the sample. A load of 49 g of pad was applied and heating was performed at a temperature rising rate of 10 ° C./min, and the temperature when the needle penetrated to a depth of 0.1 mm was read and used as the softening point.

A copolymer having a crystallinity of less than 15% by X-ray has low mechanical strength, while a copolymer having a crystallinity of more than 35% has poor flexibility. The crystallinity in the present invention is 1.0 mm after 20 hours of molding.
2 x 4 cm sample was taken from the press sheet of and the X-ray diffraction curve was measured by the X-ray diffraction method. The reflection angle 2θ: 4 to 30 degrees was used as the baseline to separate the crystal part and the amorphous part After measuring, the crystal part was determined as the weight%.

In addition, in each press sheet, the random copolymer (A) was put in a predetermined amount in a mold having a thickness of 0.1 and 1.0 mm, respectively, and preheated for 5 minutes in a hydraulic press molding machine heated to 240 ° C. and then pressed for 5 minutes, and then the metal sheet was pressed. The mold was immediately transferred to a cooling press molding machine cooled with water at 20 ° C., and cooling was performed for 5 minutes.

Specific examples of the α-olefin having 4 to 7 carbon atoms which is copolymerized with 4-methyl-1-pentene in the random copolymer (A) used in the present invention include 1-butene, 1-pentene and 1-hexene. , 1-heptene and the like can be exemplified. Among these α-olefins, 1-butene and 1-hexene are preferable, and 1-hexene is particularly preferable because it has the highest transparency. Copolymers with α-olefins having 3 or less carbon atoms, that is, copolymers with ethylene or propylene, reduce transparency, while having 8 or more carbon atoms, for example, 1 or less.
-Copolymers with decene, 1-hexadecene and the like also reduce transparency and mechanical strength, and neither of them can achieve the object of the present invention.

In addition to the above characteristics, the random copolymer (A) used in the present invention has a soluble content in an acetone / n-decane mixed solvent (volume ratio 1/1) at 10 ° C. of 4 × [η] ^−0.8 % by weight. Less than,
Furthermore, 0.2 × [η] ^{−0.8 to} 3.8 × [η] ^−0.8 % by weight
([Η] is the numerical value of the intrinsic viscosity of the random copolymer (A), which is a value excluding the unit), is the value of bleeding of the low molecular weight polymerized component onto the surface when processed into a film or the like. It is preferable because it does not cause stickiness due to out and is excellent in anti-blocking property and heat sealing property. The soluble content of the copolymer in the mixed solvent in the present invention is measured and determined by the following method. That is, in a 150 ml flask equipped with a stirring blade, 1 g of the copolymer sample, 0.05 g of 2,6-di-tert-butyl-4-methylphenol and 50 ml of n-decane were put, and the mixture was dissolved in oil at 120 ° C. Dissolve. After dissolution, let it cool naturally at room temperature for 30 minutes, then add 50 ml of acetone in 30 seconds,
Allow to cool for 60 minutes on a 10 ° C water bath. The precipitated copolymer and the solution of the low-molecular weight polymer component were dissolved by filtration with a glass filter, the solution was dried at 10 mmHg at 150 ° C. until a constant weight was obtained, and its weight was measured. The soluble content of the polymer was calculated and determined as a percentage with respect to the weight of the sample copolymer. In the measuring method, stirring was continuously performed from the time of dissolution until immediately before filtration.

The 4-methyl-1-pentene / α-olefin random copolymer (A) having various properties as described above is, for example, (a) a magnesium compound, a titanium compound, a diester, and optionally a halogen compound (magnesium compound). Or a highly active titanium catalyst component containing magnesium, titanium, halogen and a diester as essential components, which are formed by reacting each other) when the titanium compound contains a halogen atom). In the presence of a catalyst formed from an aluminum compound catalyst component and (c) an organosilicon compound catalyst component having a Si—O—C bond, 4-methyl-1-pentene is added at a temperature of about 20 to about 200 ° C. It is obtained by copolymerizing with α-olefin having 4 to 7 carbon atoms such as 1-butene and 1-hexene. Regarding the copolymerization conditions and the like for producing the random copolymer (A) suitable for use in the present invention as described above, Japanese Patent Application No. 60-2162 by the applicant of the present invention can be referred to.
See 586 for details.

The poly-4-methyl-1-pentene (B) used in the composition of the present invention is a homopolymer of 4-methyl-1-pentene or 4-methyl-1-pentene and another α-olefin,
For example, ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-tetradecene, 1
-Copolymer with α-olefin having 2 to 20 carbon atoms, such as octadecene, wherein 4-methyl-1-pentene is 85
It is a copolymer containing mol% or more. Poly-4-methyl-1-
Penten (B) melt flow rate (MFR, load: 5 kg,
Temperature: 260 ° C.) is preferably in the range 0.5 to 200 g / 10 min. If the MFR is less than 0.5 g / 10 min, the melt viscosity is high and the molding is inferior. If the MFR is more than 200 g / 10 min, the melt viscosity is low and the moldability is poor, and the mechanical strength is low.

The resin composition for medical devices of the present invention comprises more than 80% by weight of the random copolymer (A) and 100% by weight or less, and 0 to less than 20% by weight of the poly-4-methyl-1-pentene (B). Is included. The composition of the present invention may be composed of the random copolymer (A) alone, but in order to adjust the flexibility, heat resistance, mechanical strength, etc. of the medical device,
The composition containing the poly-4-methyl-1-pentene (B)
You may add up to less than 20 weight% with respect to weight. Poly 4
When the amount of -methyl-1-pentene (B) exceeds 60% by weight, flexibility decreases.

Random copolymer (A) for producing the composition of the present invention
And poly 4-methyl-1-pentene (B) by various known methods within the above range, for example, a method of mixing with a V-blender, a ribbon blender, a Hensiel mixer, a tumbler blender, or after mixing with the above blender, extrusion. Granulation method, single screw extruder, double screw extruder, kneader,
Melt-kneading with a Banbury mixer or the like, and granulating or pulverizing, or previously polymerizing a predetermined amount of random copolymer (A) or poly-4-methyl-1-pentene (B) in one polymerization reaction system. After that, continue with poly-4-methyl-
It may be produced by polymerization as a non-polymer blend type composition by so-called block polymerization, in which 1-pentene (B) or random copolymer (A) is polymerized in a predetermined amount.

In the composition of the present invention, in addition to the above components, a weather resistance stabilizer, a heat resistance stabilizer, an antistatic agent, an anti-blocking agent, a slip agent, a lubricant, a hydrochloric acid absorbent, a pigment, a dye, a drip agent, a nucleating agent, etc. Various compounding agents which are usually used by adding to polyolefin may be added within a range that does not impair the object of the present invention.

The medical device produced from the composition of the present invention is a film,
It is a device used for medical treatment such as a blood preservation bag, an infusion bag, an infusion bottle, a blood transfusion set, a gasket, a filter, and a container in the shape of a tube, a sheet, a hollow bottle, a tray, a pipe, a container, a monofilament.

〔The invention's effect〕

The resin composition for medical devices of the present invention is superior to conventional soft PVC in heat resistance, anti-blocking property, excellent water repellency, and without containing a large amount of plasticizer, transparency, flexibility, heat sealability, Since it has good cold resistance and moldability, it can be molded into a tube, film, sheet, hollow container, etc.
Even if it is subjected to autoclaving at 0 ° C or higher, there is no change in the molded product, and there is no occurrence of blocking due to bleeding of the plasticizer, transfer to chemicals, etc. is there.

〔Example〕

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.

Example 1 [Production of 4-methyl-1-pentene / 1-hexene random copolymer] <Preparation of titanium catalyst component (a)> 4.76 g (50 mmol) of anhydrous magnesium chloride, 250 ml of decane and 23.4 ml of 2-ethylhexyl alcohol. (150 mmol)
Was heated at 130 ° C for 2 hours to form a uniform solution, and 1.11 g (7.5 mmol) of phthalic anhydride was added to this solution.
Stir-mixing is further performed at 0 ° C. for 1 hour to dissolve phthalic anhydride in the homogeneous solution. After cooling the homogeneous solution thus obtained to room temperature, titanium tetrachloride kept at -20 ° C.
The total amount is dropped into 200 ml (1.8 mmol) over 1 hour. After the charging is completed, the temperature of this mixed solution is 110 for 4 hours.
The temperature was raised to ℃, and when it reached 110 ℃, 2.68 ml (12.5 mmol) of diisobutyl phthalate was added, and the mixture was maintained at the same temperature for 2 hours with stirring. After completion of the reaction for 2 hours, a solid portion was collected by hot filtration, and the solid portion was resuspended in 200 ml of TiCl ₄ and then heated at 110 ° C. for 2 hours. After the completion of the reaction, the solid part is again collected by hot filtration and thoroughly washed with decane and hexane at 110 ° C. until no free titanium compound is detected in the washing liquid. The titanium catalyst component (a) prepared by the above production method was stored as a hexane slurry, and a part of this was dried for the purpose of examining the catalyst composition. The titanium catalyst component (a) thus obtained had a composition of 3.1 wt% titanium, 56.0 wt% chlorine, 17.0 wt% magnesium and 20.9 wt% diisobutylphthalate.
It was.

<Polymerization> Into a 200 SUS reaction kettle, 20 1-hexene, 60 4-methyl-1-pentene (hereinafter abbreviated as 4MP), 80 mmol triethylaluminum, 80 mmol triethylmethoxysilane, titanium atom per hour Converted to 1.2 mmol
Titanium catalyst component (a) was continuously charged. The hydrogen partial pressure in the gas phase was kept at 1.5 kg / cm ² , and the polymerization temperature was kept at 70 ° C.

The polymerization liquid was continuously withdrawn so that the liquid amount in the reaction vessel became 100, the polymerization was stopped with a small amount of methanol, and the unreacted monomer was removed to obtain 7.5 kg of a copolymer per hour. 4-Methyl-1-pentene.1-obtained in this way
Hexene random copolymer (abbreviated as PMH-I below) is 4MP
Content of 55 mol%, melting point of 168 ° C, softening point of 140 ° C, crystallinity of 24%, intrinsic viscosity [η] of 2.2 dl / g and acetone / n-decane-soluble component of 1.7% by weight. Atsuta

[Manufacture of molded products]

0.12 parts by weight of phenolic antioxidant in 100 parts by weight of PMH-I.
After adding by weight, a composition-I was obtained by granulating with a 40 mmφ extruder (molding temperature: 230 ° C.).

An injection molding machine (molding temperature of 260 ° C.) using the composition-I
Manufactured a square plate of 130 × 130 × 2 mm. Separately, the composition-I is melted in a 50 mmφ extruder (molding temperature 200 ° C.) and then T-
It was supplied to a die (molding temperature 200 ° C.) to manufacture a sheet having a thickness of 200 μm. Further, the composition-I was melted by a 30 mmφ extruder (molding temperature 200 ° C.) and then fed to a tube manufacturing die (molding temperature 200 ° C.) to manufacture a tube having an outer diameter of 8 mm and an inner diameter of 5 mm. The following methods evaluated the performance of such a square board, a sheet, and a tube.

Using injection molded square plate Haze (%): ASTM D 1003 Torsional rigidity: ASTM D 1043 Low temperature embrittlement point: ASTM D 746 Contact angle with water: Distilled water droplets with a diameter of about 2 mm are squared from the injection needle. The angle formed by the water droplet and the square plate was measured by dropping it on top.

Formability of sheet / tube: ○ The surface is smooth.

 △ The surface skin is slightly rough.

 × The skin is extremely rough.

Autoclaving: Put the sample in the autoclave, 121 ℃
After performing high-pressure steam sterilization treatment for -30 minutes, the deformation of the sample, the presence or absence of bleeding and blocking, and the haze were measured.

The results are shown in Table 1.

Example 2 Instead of PMH-I used in Example 1, 1-hexene and 4MP
By changing the charging amount of, and 4MP content 70 mol% obtained by polymerization by appropriately changing the hydrogen partial pressure, melting point 195 ℃,
4-methyl-1-pentene / 1-hexene random copolymer having a softening point of 165 ° C., a crystallinity of 26%, an intrinsic viscosity [η] of 2.5 dl / g and an acetone / n-decane soluble content of 2.0% by weight (hereinafter
The same procedure as in Example 1 was performed except that PMH-II was used. The results are shown in Table 1.

Comparative Example 1 P used in Example 3 in place of PMH-I used in Example 1
The same procedure as in Example 1 was carried out using MH-I, except that the molding temperature was 240 ° C. The results are shown in Table 1.

Comparative Example 2 Instead of PMH-I used in Example 1, 100 parts by weight of polyvinyl chloride resin was mixed with 70 parts by weight of dioctyl phthalate, and a soft polyvinyl chloride resin (hereinafter abbreviated as PVC) was used. After that, the same procedure as in Example 1 was performed.
The results are shown in Table 1.

Claims (1)

[Claims] 1. The content of (a) 4-methyl-1-pentene
40-80 mol%, melting point 140-220 ° C, softening point 90
4-methyl-1-pentene having a crystallinity in the range of 15 to 35% by X-rays and α-olefin having 4 to 7 carbon atoms (excluding 4-methyl-1-pentene). More than 80% by weight of random copolymer (A)
100% by weight or less, (B) 4-methyl-1-pentene homopolymer or 4-methyl-1-pentene containing 85% by mole or more of 4-methyl-1-pentene and α- having 2 to 20 carbon atoms A resin composition for medical devices, comprising 0 to less than 20% by weight of a copolymer (B) with olefin.