JPH05310868A - Composition for medical material - Google Patents

Abstract

PURPOSE:To provide a block copolymer compsn. which scarecely adsorbs a drug component and has satisfactory clarity and flexibility essentially required as a medical material. CONSTITUTION:The compsn. contains, as the main component, a block copolymer comprising isobutylene polymer segments A with a glass transition temperature of -40 deg.C or lower and polymer segments B with a glass transition temperature of +50 deg.C or higher.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a medical thermoplastic polymer having an isobutylene polymer segment as a main component, which is suitable as a molding material for medical instruments and containers represented by blood bags and medical tubes. It relates to a composition.

[0002]

2. Description of the Related Art Conventionally, soft polyvinyl chloride which is flexible and easy to handle has been widely adopted as a medical material such as an infusion / blood transfusion set and a drug solution container. However, since a large amount of plasticizers are added to soft polyvinyl chloride, plasticizers may migrate to the surface (bleeding), or may be extracted depending on the type of liquid chemicals used, which may lead to hygiene and medical problems. Often becomes a problem, and because the molecular structure is polar, it sorbs fat-soluble drug components such as nitroglycerin, isosorbite nitrate, and diazebam to reduce drug efficacy. On the contrary, there was a risk of elution. Further, when incinerated for safe disposal after use, hydrogen chloride gas is generated to wear the incinerator, and there is a problem in terms of environmental pollution.

Further, conventionally, a polystyrene-polybutadiene-polystyrene block copolymer (hereinafter referred to as "SB
"S". ) Or a block copolymer obtained by hydrogenating the polybutadiene portion of SBS (hereinafter referred to as “SEBS”) is known to be a thermoplastic elastomer exhibiting excellent elastomer elasticity at room temperature. SBS and S
As a composition utilizing EBS's original excellent rubber performance, a composition consisting of polypropylene and SBS or SEBS is industrially used as a composition having excellent performance as an elastomer, but it has excellent transparency and flexibility. Lack. A composition consisting of polypropylene and SBS or SEBS is used as a molding material for medical devices and containers, but it has a high physical property balance of heat resistance, mechanical strength, transparency and flexibility, and a high adsorption level for drug components. Is not enough.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides heat resistance, mechanical strength, and heat resistance suitable as a molding material for medical instruments and containers.
An object of the present invention is to provide a medical thermoplastic polymer composition having an excellent balance of physical properties of transparency and flexibility.

[0005]

The composition for medical materials of the present invention comprises an isobutylene polymer segment A having a glass transition point of −40 ° C. or lower and a polymer segment B having a glass transition point of + 50 ° C. or higher. It is characterized in that the constituent block copolymer is contained as a main component.

The present invention will be described in detail below. The block copolymer constituting the present invention has a glass transition point of −40 ° C.
It is composed of the following isobutylene-based polymer segment A (hereinafter, also simply referred to as “polymer segment A”) and a polymer segment B having a glass transition point of + 50 ° C. or higher.

The polymer segment A has a glass transition point of −
It is an isobutylene-based segment at 40 ° C or lower. Here, the polymer segment A may be a homopolymer segment of isobutylene, but with isobutylene,
It may be a copolymer segment with a cationically polymerizable monomer copolymerizable therewith. In this case, the proportion of isobutylene in the copolymer segment is 50% by weight or more. Further, as the cationically polymerizable monomer constituting the copolymer segment, one kind or two or more kinds thereof can be used within a range in which the glass transition point of the copolymer segment is maintained at -40 ° C or lower.

The cationically polymerizable monomer copolymerizable with isobutylene is selected from, for example, olefins having 3 to 12 carbon atoms, conjugated dienes, vinyl ethers, aromatic vinyl compounds, vinylsilanes and allylsilanes. Can be mentioned. Of these, olefins having 3 to 12 carbon atoms or conjugated dienes are preferable. Specific examples of such cationically polymerizable monomers include propylene, 1-butene, 2-butene,
2-methyl-1-butene, 3-methyl-1-butene, pentene, 4-methyl-1-pentene, hexene, vinylcyclohexane, butadiene, isoprene, cyclopentadiene, methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, styrene, α -Methylstyrene, dimethylstyrene, monochlorostyrene, dichlorostyrene, β-pinene, indene, vinyltrichlorosilane, vinylmethyldichlorosilane, vinyldimethylchlorosilane, vinyldimethylmethoxysilane, vinyltrimethylsilane, divinyldichlorosilane, divinyldimethoxysilane, divinyl. Dimethylsilane, 1,
3-civinyl-1,1,3,3-tetramethyldisiloxane, trivinylmethylsilane, tetravinylsilane,
Allyltrichlorosilane, allylmethyldichlorosilane, allyldimethylchlorosilane, allyldimethylmethoxysilane, allyltrimethylsilane, diallyldichlorosilane, diallyldimethoxysilane, diallyldimethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylmethyldimethoxy Examples thereof include silane. Of these, propylene, 1-butene, 2-butene, styrene, butadiene, isoprene and cyclopentadiene are preferable.

The polymer segment B has a glass transition point of +
It is a (co) polymer segment of 50 ° C. or higher. The monomer for obtaining the polymer segment B may be either a cationically polymerizable monomer or an anionically polymerizable monomer.

Specific examples of the cationically polymerizable monomer constituting the polymer segment B include the same as the above-mentioned cationically polymerizable monomer exemplified as the component constituting the polymer segment A, and particularly preferable ones. Examples thereof include aromatic vinyl compounds such as styrene, α-methylstyrene, dimethylstyrene and monochlorostyrene, and indene. When the polymer segment B is constituted by using these cationically polymerizable monomers, the polymer segment may be constituted alone, or two or more kinds thereof may be constituted as the copolymer segment.

Examples of the anionic polymerizable monomer constituting the polymer segment B include those selected from olefins having 3 to 12 carbon atoms, conjugated dienes, aromatic vinyl compounds and (meth) acrylic acid esters. be able to. Among these, anionic polymerizable monomers selected from (meth) acrylic acid esters are preferable. Specific examples of anionic polymerizable monomers selected from (meth) acrylic acid esters include methyl acrylate, ethyl acrylate, n-propyl acrylate,
Isopropyl acrylate, isobutyl acrylate,
n-pentyl acrylate, isoamyl acrylate,
n-hexyl acrylate, 2-methylpentyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, n-decyl acrylate, n-dodecyl acrylate, n-tetradecyl acrylate, n-
Octadecyl acrylate, n-eicosyl acrylate; methyl methacrylate, ethyl methacrylate, n
-Hexyl methacrylate, n-octyl methacrylate, n-dodecyl methacrylate, n-octadecyl methacrylate; methoxyethyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, ethoxypropyl acrylate, methoxyethyl methacrylate and the like.

When the polymer segment B is constituted by using these anionically polymerizable monomers, the polymer segment may be constituted alone, or two or more kinds thereof may be constituted as the copolymer segment.

The block copolymer constituting the composition for medical materials of the present invention is obtained by polymerizing the polymer segment A by a conventional method and then successively adding the monomers constituting the polymer segment B. be able to.

When a cationically polymerizable monomer is used as the monomer constituting the polymer segment B, the block copolymer can be synthesized by, for example, a known method reported by Kennedy et al. [J. Polym. S
ci. , Part A; Polym. Chem. 29,4
27-435 (1991)], polymerization of the polymer segment A was performed using an initiator component composed of 1,4-bis (2-methoxy-2-propylbenzene), titanium tetrachloride and N-dimethylacetamide. Then, a method of sequentially adding a cationically polymerizable monomer that constitutes the polymer segment B can be mentioned.

When an anion-polymerizable monomer is used as the monomer constituting the polymer segment B, the method for synthesizing the block copolymer is, for example, α, ω-di (tert-chloro) polyisobutylene at the polymer terminal. Toluene is added by the Friedel-Crafts reaction to
Further, sec-BuLi is reacted to prepare an α, ω-dibenzyllithiopolyisobutylene macroinitiator, which is copolymerized with a (meth) acrylic acid ester polymer segment. The method of Kennedy et al. [Po
lymeric Materials Science
and Engineering, 64, 40 (19
91)].

In the block copolymer constituting the present invention, the arrangement of the polymer segment A and the polymer segment B is not particularly limited and can be any arrangement shape. For example, (polymer segment A-polymer segment B) _p , (polymer segment A-polymer segment B-polymer segment A) _q , (polymer segment B-polymer segment A-polymer segment B)
_r [p, q and r are the numbers of repeating units represented by arbitrary integers. ] It may be a linear array represented by the following, or a multi-branched star-shaped array having a polymer segment A (B) as a nucleus and a polymer segment B (A) as a branched chain, Good.

In the block copolymer constituting the present invention, the ratio of the polymer segment A to the polymer segment B is "polymer segment A: polymer segment B".
(Weight ratio) "is preferably 40:60 to 95: 5, and more preferably 50:50 to 90:10. When the proportion of the polymer segment A is too large,
The resulting block copolymer tends not to have the characteristics as a thermoplastic elastomer. On the other hand, when the proportion of the polymer segment B is too large, the transparency and flexibility of the resulting block copolymer are It is inferior and cannot be suitably used as a medical material.

The block copolymer composition of the present invention may contain additives used in ordinary thermoplastic resins, if necessary. Examples of the additives include plasticizers such as phthalic acid ester, softening agents for rubber, fillers or reinforcing agents such as silica, talc and glass fiber, and other antioxidants, ultraviolet absorbers, antistatic agents, flame retardants, Lubricants, foaming agents, colorants, pigments, nucleating agents, cross-linking agents, cross-linking aids, etc., or mixtures thereof can be mentioned. In addition, rubber-like polymers such as SBR, NBR, and B, if necessary.
R, EPT, EPR, NR, IR, 1,2-polybutadiene, AR, CR, IIR, HSR and the like can be added. In addition, if necessary, a thermoplastic resin such as an olefin resin, a diene resin, a hydrogenated product of a diene resin, a polyvinyl chloride resin, a polyvinyl acetate resin, a polycarbonate resin, a polyacetal resin, or a polyamide. A resin, a polyester resin, a polyether resin, a polysulfone, a polyphenylene sulfide, or the like may be added.

The block copolymer composition of the present application can be used in a usual kneading device such as a rubber mill, a Brabender mixer, a Banbury mixer, a pressure kneader, a ruder, a twin-screw extruder, etc., but a closed type or an open type However, a type that can be replaced by an inert gas is preferable. The kneading temperature is a temperature at which all the components to be mixed melt, and is usually 170 to 250 ° C, preferably 180 to 240 ° C. Also,
The kneading time depends on the type and amount of the constituents and the kneading device and cannot be generally discussed, but when a pressure kneader, Banbury mixer or the like is used as the kneading device, it is usually about 3 to 10. It's about a minute. Furthermore, when kneading, each component may be kneaded at once, or after kneading arbitrary components, the remaining components may be added and kneading may be carried out. The composition of the present invention can be molded into a practically useful molded product by a conventionally known method such as extrusion molding, injection molding, blow molding, compression molding, or calendering.

[0020]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded. In the examples,
Various physical properties were evaluated by the following methods. Tensile properties Measured according to JIS K6301. The unit of tensile breaking strength is kgf / cm ² , and the unit of tensile breaking elongation is%. A sample having a heat resistance of 2 mm and a thickness of 2 cm was aged in a oven at 120 ° C. for 30 minutes, and the presence or absence of shrinkage of the sample after aging was determined. O indicates that the shrinkage is less than 3%, Δ indicates that the shrinkage is 3 to 6%, and X indicates that the shrinkage is greater than 6%. Using transparent Suga Test Instruments Co., Ltd. Multi light source spectrophotometer, by measuring the haze of a sheet of about 0.4 mm, it was determined. The lower the number, the more transparent. Flexibility JIS A hardness was measured according to JIS K6301. Nitroglycerin (Nippon Kayaku Co., Ltd.) was used for 500 ml of 1 bag of physiological saline prepared using each adsorbent sample.
Manufactured by Millisrol Injection 6A, 30 mg) and mixed with 60 ml, and using a Sharp infusion pump STP-11 type, a drop solution after 5 minutes from the start of infusion at a flow rate of 0.6 ml / min was placed in a test tube, and nitro. The content of glycerin was measured by high performance liquid chromatography (HPLC
Method). Device: Hitachi, Model 655 liquid chromatograph column: Nuclosil 7C18 (4.6 mmφ x
25 cm) Detection wavelength; 220 nm Mobile phase; Methanol: water = 65: 35 Flow rate; 1.0 ml / min Sample injection amount; 10 microliters Column temperature; 30 ° C. Sensitivity; 0.08 anfs In the drop solution 5 minutes after the start of infusion Nitroglycerin content in the range of 90 to 100% of the initial value is ○, that in the range of 80 to 90% of the initial value is △, 80% of the initial value
The results are summarized in Table 1 with x in the following range.

[0021]

[Table 1]

[0022]

Example 1 A block copolymerization (1) comprising a homopolymerized segment of isobutylene (polymer segment A) and a homopolymerized segment of styrene (polymer segment B) was reported by Kennedy et al. [J. Polym. Sci. , PartA: Po
lym. Chem. 29, 427-435 (199
1)] to produce a polymer composition comprising the block copolymer (1) (hereinafter referred to as "composition I-"). Here, the weight ratio [polymer segment A: polymer segment B] of the polymer segment A and the polymer segment B in the composition I- was 61:39. The glass transition point of each polymer segment is
When measured according to D3418, the glass transition point of the polymer segment A was -68 ° C, and the glass transition point of the polymer segment B was 98 ° C.

[0023]

Example 2 A block copolymer (2) consisting of a homopolymerized segment of isobutylene (polymer segment A) and a homopolymerized segment of methyl methacrylate (polymer segment B) was reported by Kennedy et al. Known method [Polymeric Material
s Science and Engineering
g, 64, 40 (1991) ”] to produce a polymer composition comprising the block copolymer (2) (hereinafter referred to as“ composition part I- ”). Here, the composition I-
Weight ratio of polymer segment A and polymer segment B in [Polymer segment A: Polymer segment B]
Is 72:28. When the glass transition point of each polymer segment was measured according to ASTM D3418, the glass transition point of the polymer segment A was -63 ° C.
And the glass transition point of the polymer segment B is 102 ° C.
Met.

From the results shown in Table 1, the thermoplastic polymer composition of the present invention has an excellent balance of physical properties such as mechanical strength, heat resistance, transparency and flexibility, and is a bag of drug components when used as an infusion bag. It can be seen that the amount of adsorption to the wall is small.

[0025]

[Comparative Example 1] Evaluation was performed in the same procedure as in Example 1 except that SBS (JSR TR2000 manufactured by Nippon Synthetic Rubber Co., Ltd.) was opened as a polymer.

[0026]

Comparative Example 2 Evaluation was carried out by the same procedure as in Example 1 except that SEBS (Kraton G1650, manufactured by Shell Chemical Co., Ltd.) was opened as a polymer.

As shown in Table-1, SBS, SBES
Although all of them have excellent mechanical strength and transparency, they are inferior in heat resistance and flexibility, and the adsorption amount level of the drug component is high, which is not preferable.

[0028]

EFFECTS OF THE INVENTION The block copolymer composition of the present invention has an excellent balance of physical properties such as mechanical strength, heat resistance, transparency and flexibility, and has an extremely low level of adsorption of drug components to the bag wall. , Infusion bag, infusion tube, syringe,
A composition suitable for medical use such as a gasket, a blood bag, a blood tube, etc. is provided.

Claims (1)

[Claims] 1. An isobutylene polymer segment A having a glass transition point of −40 ° C. or lower, and a glass transition point of + 50 ° C.
A composition for medical materials, comprising a block copolymer composed of the above polymer segment B as a main component.