JPH0810317A - Medical material composition and medical molding - Google Patents

Abstract

PURPOSE:To provide a medical material composition which has a low toxicity, large tensile strength and elongation, and small percentage permanent elongation by taking essential components by mixing plural diene polymers different in the number average molecular weight and an organic peroxide at a specified ratio. CONSTITUTION:Diene polymer (a) of 5-50wt. parts with the number average molecular weight of 20000-250000, 95-50wt. parts diene polymer with the number average molecular weight of 300000-2000000, and 0.01-1wt. parts organic peroxide are taken as essential components. Among all diene monomer units container in each of both diene polymers (a), (b), the total amount of diene monomer units 1,2- or 3,4-bonded to adjacent monomer units is set to 0.2-20mol%, the amount of diene monomer units cis-1,4 bonded to adjacent monomer units is set to 80-99.8% and the amount of diene monomer units trans-1,4 bonded to adjacent monomer units is set to 0-19.8mol%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical molded product and a medical material composition, and more specifically, it can be applied to a portion having a high expansion and contraction rate such as a balloon of a catheter and has low toxicity,
The present invention relates to a medical molded article having high tensile strength and elongation and low permanent elongation, and a medical material composition for obtaining the molded article.

[0002]

2. Description of the Related Art Medical moldings such as catheters and artificial blood vessels used for treatment of living bodies are required to have low toxicity, high tensile strength and elongation and small permanent elongation. Natural rubber is well known as a material for obtaining a medical molded product for a balloon of a balloon catheter. However, since natural rubber contains trace amounts of impurities, it has recently been found that when a molded product made of natural rubber is used, a bio-allergic reaction occurs.
Therefore, development of a medical material composition that replaces natural rubber has been desired. As an alternative medical material composition, a molecular weight of 30,000 to 300,00 consisting of only isoprene units bonded to adjacent isoprene units by cis-1,4-bonds
Zero high cis polyisoprene is known. The molecular structure of this high-cis polyisoprene is very close to that of natural rubber. However, since high cis polyisoprene has a lower tear strength and a lower tensile strength than a molded product of natural rubber obtained by using it as a material, it cannot completely replace natural rubber. Therefore, in order to increase the tensile strength of this high-cis polyisoprene, a cross-linked high-cis polyisoprene obtained by blending with an organic peroxide and crosslinking was proposed. Since the polymer main chain was cleaved, the crosslinked high-cis polyisoprene molded product had lower tensile strength and elongation and a larger permanent elongation than the natural rubber molded product.

[0003]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a medical molded product which has low toxicity, high tensile strength and elongation, low permanent elongation, and a high stretch ratio, and a medical molded product which can be suitably used. It is to provide a medical material composition for obtaining. As a result of intensive studies to achieve this object, the inventors have found that the object can be achieved by crosslinking a material composition containing a specific diene polymer and an organic peroxide as essential components. The present invention has been found and based on this finding, the present invention has been completed.

[0004]

Thus, according to the present invention, 5 to 50 parts by weight of a diene polymer (a) having a number average molecular weight of 20,000 to 250,000 and a number average molecular weight of 30 are used.
95 to 50 parts by weight of the diene polymer (b) of 20,000 to 2,000,000 (however, the diene polymer (a)
And the total amount of the diene polymer (b) is 100 parts by weight. ) And 0.01 to 1 part by weight of an organic peroxide as an essential component, and adjacent diene-based monomer units among all diene-based monomer units contained in the diene-based polymer (a) and the diene-based polymer (b). The total amount of the dimer monomer unit that is 1,2-bonded or 3,4-bonded with the monomer unit is 0.2 to 20 mol%, and the adjacent monomer unit and cis-1,4- The amount of the diene monomer unit bonded by a bond is 80 to 99.8 mol% and the amount of the diene monomer unit bonded by the trans-1,4-bond with the adjacent monomer unit is There is provided a medical material composition, which is characterized in that the amount is 0 to 19.8 mol%. Also,
According to the present invention, there is provided a medical molded article obtained by crosslinking the above medical material composition.

The medical material composition of the present invention comprises a diene polymer (a), a diene polymer (b) and an organic peroxide as essential components.

In the medical material composition of the present invention, the diene polymer (a) and the diene polymer (b) each contain a diene monomer as an essential monomer unit. The diene polymer is usually obtained by polymerizing a monomer mixture containing a diene monomer as an essential component. As the diene-based monomer, 1,3-butadiene, isoprene, 2,3-
Dimethyl-1,3-butadiene, 2-ethyl-1,3-
Examples thereof include butadiene, 1,3-pentadiene and chloroprene. Among the diene-based monomers, isoprene or 1,3-butadiene is preferable. The amount of the diene monomer is usually 40 to 100% by weight, preferably 8% by weight of the monomer mixture used for obtaining the diene polymer.
It is 0 to 100% by weight.

As the monomers other than the diene monomer, ethylenically unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid and itaconic acid; styrene, α-methylstyrene, vinyl Aromatic vinyl monomers such as toluene and monochlorostyrene; ethylenically unsaturated nitrile monomers such as acrylonitrile, methacrylonitrile, fumaronitrile, α-chloroacrylonitrile, α-cyanoethylacrylonitrile; methyl acrylate, methyl methacrylate, acrylic Ethylenically unsaturated carboxylic acid alkyl esters such as ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate; β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-methacrylic acid Hydroxy Ethylenically unsaturated carboxylic acid hydroxyalkyl ester such as propyl; acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, diacetone acrylamide and other ethylenically unsaturated carboxylic acid alkyl amide; glycidyl acrylate, glycidyl methacrylate And so on.

As the diene polymer (a) or the diene polymer (b), a homopolymer of a diene monomer such as polyisoprene, polybutadiene or polychloroprene;
Examples thereof include copolymers of diene-based monomers and monoene-based monomers such as styrene-butadiene copolymers and acrylonitrile-butadiene copolymers. Of these, polyisoprene or polybutadiene is preferable.

The lower limit of the number average molecular weight of the diene polymer (a) used in the medical material composition of the present invention is 20,000.
0, preferably 40,000, with an upper limit of 25
50,000, preferably 200,000.
If it is less than 20,000, the permanent elongation of the medical molded article obtained by crosslinking the medical material composition becomes large, and conversely 300,
If it exceeds 000, the composition for medical materials becomes so hard that it cannot be used for medical moldings. The number average molecular weight is a value converted to the number average molecular weight of standard polystyrene after measurement using gel permeation chromatography.

The diene-based polymer (a) is composed of the diene-based monomer units contained therein and the adjacent monomer units.
The total amount of 2-bonded or 3,4-bonded diene-based monomer units is usually 0.2 to 70 mol%, preferably 1
˜50 mol%, and more preferably 3 to 30 mol%. If it is less than 0.2 mol%, the permanent elongation becomes large. On the other hand, when it exceeds 70 mol%, the elongation of the medical molded article decreases. The diene-based polymer (a) is composed of the diene-based monomer units contained in the diene-based polymer (a) and adjacent cis-1,
It may contain a diene-based monomer unit that is 4-bonded or trans-1,4-bonded. The amount of the diene monomer unit that is cis-1,4-bonded with the adjacent monomer unit is usually 30 to 99 of the diene monomer units contained in the diene polymer (a). 0.8 mol%, preferably 50
˜99 mol%, more preferably 70 to 97 mol%. The amount of the diene-based monomer unit that is trans-1,4-bonded to the adjacent monomer unit is usually 30 mol of the diene-based monomer unit contained in the diene-based polymer (a). % Or less, preferably 10 mol% or less. In addition,
Each amount of the 1,2-bonded, 3,4-bonded, cis-1,4-bonded or trans-1,4-bonded diene-based monomer unit was determined by using ¹ HNMR for the diene-based polymer. It is a value obtained by measurement.

The lower limit of the number average molecular weight of the diene polymer (b) used in the medical material composition of the present invention is 300,0.
00, preferably 400,000, and the upper limit is 2,000,000, preferably 1,000,000. If it is less than 300,000, the elongation of the medical molded article obtained by crosslinking the medical material composition is lowered,
When it exceeds 100,000, the medical material composition becomes too hard and is not suitable as a material composition for obtaining a medical molded article.

The diene-based polymer (b) is the amount of the diene-based monomer units that are cis-1,4-bonded with the adjacent monomer units among the diene-based monomer units contained therein. Is usually 85 mol% or more, preferably 90 mol% or more. If it is less than 85 mol%, the tensile strength of the medical molded product is lowered. The diene polymer (b) has 1,2-bonds, 3,4-bonds or trans-1,4-bonds with adjacent monomer units.
It may have a diene monomer unit attached. The amount of the diene-based monomer unit that is trans-1,4-bonded with the adjacent monomer unit is usually 10 mol% of the diene-based monomer unit contained in the diene-based polymer (b). The amount is preferably 7 mol% or less. The total amount of the diene-based monomer units that are 1,2-bonded or 3,4-bonded with the adjacent monomer units is the diene-based monomer units contained in the diene-based polymer (b), Usually 5 mol% or less, preferably 3
It is not more than mol%.

The amount of the diene polymer (a) used in the medical material composition of the present invention is 5 to 50 parts by weight, preferably 10 to 30 parts by weight. When the amount of the diene polymer (a) decreases, the permanent set increases. When the amount of the diene polymer (a) is large, the tensile strength and elongation of the medical molded article are low. The amount of the diene polymer (b) is 100 when the total amount of the diene polymer (a) and the diene polymer (b) is 100.
The amount is parts by weight.

In the medical material composition of the present invention, the diene polymer (a) and the diene polymer (b) are combined with adjacent monomer units by 1,2-bond, 3,4-bond and cis-bond. 1,
The amount of 4-bonded or trans-1,4-bonded diene-based monomer units is based on the total amount of diene-based monomer units contained in the diene-based polymer (a) and the diene-based polymer (b). On the other hand, each is in a specific range.

The lower limit of the total amount of the diene monomer units 1,2-bonded or 3,4-bonded to the adjacent monomer units is 0.2 mol%, preferably 0.5 mol%. And
The upper limit is 20 mol%, preferably 10 mol%. 0.
When it is less than 2 mol%, the tensile strength of the medical molded product is lowered and the permanent set is increased. On the other hand, if it exceeds 20 mol%, the tensile strength and elongation will be low, and the composition will be brittle.

The lower limit of the amount of the diene monomer unit which is cis-1,4-bonded with the adjacent monomer unit is included in the diene polymer (a) and the diene polymer (b). 80 mol%, preferably 90 mol% of all diene monomer units
And the upper limit is 99.8 mol%, preferably 99.5 mol%.

In addition, adjacent monomer units and trans-
The upper limit of the amount of 1,4-bonded diene monomer units is 19.8 mol% of all the diene monomer units contained in the diene polymer (a) and the diene polymer (b). , Preferably 9.5 mol%. In addition, each amount of the diene-based monomer unit which is 1,2-bonded, 3,4-bonded, cis-1,4-bonded or trans-1,4-bonded with the adjacent monomer unit is: Diene polymer (a) and diene polymer (b)
It is the value obtained by measuring the mixture of and by using ¹ H NMR.

The organic peroxide used in the medical material composition of the present invention is generally used as a cross-linking agent for a diene polymer, and preferably generates a radical at 130 ° C. or lower to cause a cross-linking reaction. It is a thing. Specifically, t-butyl hydroperoxide, di-t-butyl hydroperoxide, 2,5-dimethyl-2,5
-Di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-
3,2,5-Dimethylhexane-2,5-di (peroxybenzoate), 1,3-bis (t-butylperoxyisopropyl) benzene, 1,3-bis (t-butylperoxy) -3, 3,5-trimethylcyclohexane, n-butyl-4,4-bis (t-butylperoxy) valerate, butylperoxybenzoate, t-
Butyl peroxy isopropyl carbonate etc. are mentioned. The lower limit of the amount of the organic peroxide is 0.01 part by weight, preferably 0.1 part by weight, based on 100 parts by weight of the total amount of the diene polymer (a) and the diene polymer (b).
More preferably 0.3 part by weight, the upper limit is 1 part by weight, preferably 0.8 part by weight, more preferably 0.6 part by weight.
Parts by weight. If it is less than 0.01 part by weight, the permanent elongation of the medical molded product obtained by crosslinking the medical material composition will be large, and if it exceeds 1 part by weight, the tensile strength of the medical molded product will be reduced.

In the medical material composition of the present invention, in addition to the diene polymer (a), the diene polymer (b) and the organic peroxide, an alkylhydroquinone or an alkyl chain having 10 or more carbon atoms is used. It is preferable to add a compound selected from the lipids contained therein for the purpose of reducing the permanent elongation of the medical molded article obtained by crosslinking the medical material composition or preventing deterioration due to heat.

Alkyl hydroquinone is one in which at least one hydrogen constituting a hydroquinone molecule is substituted with an alkyl group. The number of carbon atoms of at least one alkyl group of the alkyl group is usually 2 to 7. If it is less than 2, the compatibility with the diene polymer (a) and the diene polymer (b) will be low, and the strength of the medical molded article will be low. If the number exceeds 7, the effect of blending alkylhydroquinone cannot be obtained. Specific examples of the alkylhydroquinone include 2,5-di-t-amylhydroquinone, 2,5-di-t-butylhydroquinone, 2-ethyl-5-butylhydroquinone, 2-
Examples thereof include isopropyl-5-methylhydroquinone, 2-butylhydroquinone, 2-hexylhydroquinone and hydroquinone diethyl ether. Among these, those in which hydrogen directly bonded to the benzene ring of the hydroquinone molecule is substituted with an alkyl group, such as 2,5-di-t-butylhydroquinone, are preferable. The amount of alkylhydroquinone is usually 1 part by weight or less, preferably 0.1 to 0.5 part by weight, based on 100 parts by weight of the total amount of the diene polymer (a) and the diene polymer (b). is there. When the amount is large, the effect of reducing the permanent elongation of the medical molded article obtained by crosslinking the medical material composition is reduced.

The lipid used in the medical material composition of the present invention has an alkyl chain having 10 or more carbon atoms, preferably 15 to 20 carbon atoms. A lipid is one of the substances that make up a living body, and specifically, it is a simple lipid, a complex lipid or a derivative lipid. The simple lipid is composed of carbon, hydrogen and oxygen, and specific examples thereof include long chain fatty acids such as stearic acid and oleic acid; and alkyl esters of long chain fatty acids such as triacylglycerol and cholesterol ester. The complex lipid contains nitrogen of amino group, phosphorus, sulfur of sulfuric acid and the like in addition to carbon, hydrogen and oxygen, and specifically includes phosphatidylcholine, phosphatidylethanolamine, phosphatidylseryl, diphosphatidylglycerol, sphingomyelin and the like. Phospholipids; glycolipids such as glyceroglycolipids and sphingoid glycolipids. Also included are derived lipids obtained by hydrolyzing simple lipids and complex lipids. The amount of lipid is
It is usually 2 parts by weight or less, preferably 0.2 to 0.8 parts by weight, based on 100 parts by weight of the total amount of the diene polymer (a) and the diene polymer (b). If the amount is too large, the elongation of the medical molded article obtained by crosslinking the medical material composition is lowered.

In the medical material composition of the present invention, if necessary, anti-scorch agents such as phthalic anhydride, salicylic acid, benzoic acid and malic acid; fillers such as colloidal silica, white carbon and calcium carbonate; dibutyl phthalate. , Plasticizers such as di (2-ethylhexyl) phthalate and di (2-ethylhexyl) adipate; and softeners such as white oil and paraffin.

The medical material composition of the present invention has the following properties.
It is usually a solution, dispersion or solid, preferably a solution in an organic solvent. The organic solvent used for the solution is usually one that is not compatible with water or one that is compatible with water and has an aqueous solution having a pH of 6 to 8. Specifically, aromatic hydrocarbons such as benzene, toluene and xylene;
Ethers such as tetrahydrofutane and cyclohexanone;
Examples thereof include ketones such as methyl ethyl ketone and isobutyl ethyl ketone; alicyclic hydrocarbons such as hexene and hexane.

The medical material composition of the present invention is prepared by mixing and stirring the solution of the diene polymer (a) and the solution of the diene polymer (b), and then adding and stirring the organic peroxide. After adding the organic peroxide to the solution of the diene polymer (b) and stirring, the solution of the diene polymer (a) is added and stirred, or the diene polymer (a) and the diene polymer (b) are added. After kneading and, an organic peroxide is added and stirred, and the like.

The medical molded article of the present invention is obtained by crosslinking the above-mentioned medical material composition. Crosslinking is carried out either after or before molding the medical material composition, preferably after molding. Molding is usually a melt molding method, a dipping molding method,
It is performed by a molding method such as a casting molding method, preferably a dipping molding method. For example, in the dipping molding method, a mold having a desired shape is dipped in an organic solvent solution of a medical material composition, pulled up, and left to stand.

Crosslinking is performed by heating the composition for medical materials. The heating temperature is usually 100 to 130 ° C,
It is preferably 110 to 125 ° C. Heating temperature is 100
The tensile strength of the medical molded article decreases at a temperature of less than 0 ° C or over 130 ° C. The heating time varies depending on the shape of the molded product, but is usually 10 to 400 minutes, preferably 15 to 300 minutes. When the time is short, the permanent elongation of the medical molded article becomes large, and when it is long, the tensile strength of the medical molded article decreases.

The medical molded article of the present invention has a tensile strength at break of usually 15 to 50 MPa, preferably 18 to 4
0 MPa, the elongation at break is usually 600% or more, preferably 700% or more, and the elongation after tensile force removal is usually 20% or less, preferably 10% or less, so a tube; a balloon It can be applied to catheters such as catheters; artificial hearts; artificial blood vessels; artificial valves. In particular, it is preferably applied to a portion having a high expansion / contraction rate when used, such as a balloon portion of a balloon catheter.

Preferred embodiments of the medical material composition and the medical molded article of the present invention are listed below. (1) Number average molecular weight 20,000 to 250,000 diene polymer (a) 5 to 50 parts by weight, number average molecular weight 3
95 to 50 parts by weight of the diene polymer (b) of 0,000 to 2,000,000 (however, the diene polymer (a)
And the total amount of the diene polymer (b) is 100 parts by weight. ) And 0.01 to 1 part by weight of an organic peroxide as an essential component, and adjacent diene-based monomer units among all diene-based monomer units contained in the diene-based polymer (a) and the diene-based polymer (b). The total amount of the dimer monomer unit that is 1,2-bonded or 3,4-bonded with the monomer unit is 0.2 to 20 mol%, and the adjacent monomer unit and cis-1,4- The amount of the diene monomer unit bonded by a bond is 80 to 99.8 mol% and the amount of the diene monomer unit bonded by the trans-1,4-bond with the adjacent monomer unit is The medical material composition, wherein the amount is 0 to 19.8 mol%. (2) Diene polymer (a) or diene polymer (b)
Is polybutadiene or polyisoprene, The medical material composition according to (1) above. (3) The diene polymer (a) has a molecular weight of 40,000.
~ 200,000, The medical material composition according to (1) above. (4) As the diene polymer (a), the total amount of 1,2-bonded or 3,4-bonded diene monomer units with adjacent monomer units is 0.2 to 70 mol%. And the amount of the diene-based monomer unit bonded to the adjacent monomer unit with a cis-1,4-bond is 30 to 99.8 mol% and the adjacent monomer unit and trans-1, The medical material composition according to (1) above, wherein the amount of the diene-based monomer unit bonded by 4-bond is 0 to 30 mol%. (5) The diene polymer (b) has a molecular weight of 400,00.
The medical material composition according to (1) above, which is 0 to 1,000,000. (6) As the diene polymer (b), the total amount of the diene monomer units 1,2-bonded or 3,4-bonded to the adjacent monomer units is 0 to 5 mol%, The amount of the diene-based monomer unit bonded to the adjacent monomer unit with a cis-1,4-bond is 85 to 100 mol% and the amount of the diene-based monomer unit with the adjacent monomer unit is a trans-1,4-bond. The medical material composition according to (1) above, wherein the amount of the bonded diene-based monomer unit is 0 to 10 mol%. (7) 0.1 to 0.5 parts by weight of alkylhydroquinone or an alkyl chain having 10 or more carbon atoms is further added to 100 parts by weight of the total amount of the diene polymer (a) and the diene polymer (b). The medical material composition according to the above (1), characterized in that it contains 0.2 to 0.8 part by weight of the lipid. (8) A medical molded article obtained by crosslinking the medical material composition of (1) to (6) above. (9) A medical molded product obtained by crosslinking the medical material composition according to (7).

[0029]

EFFECTS OF THE INVENTION A molded article obtained by crosslinking the medical material composition of the present invention has a large tensile strength and elongation, a small permanent elongation, and is free from toxicity such as allergies. It can be suitably used for a portion having a high expansion and contraction rate.

[0030]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the examples.

The evaluation method performed in this example will be described below.

(Tensile test) A 2 mm thick sheet was punched out with a No. 3 type dumbbell (JIS K6301), and this was JI.
According to SK-6301, the distance between chucks is 20 mm,
Tensile speed 500mm / min, temperature 23 ℃, relative humidity 65%
Under the conditions described above, the elongation and tensile strength at tensile break were determined.

(Permanent elongation) A sheet having a thickness of 2 mm was punched out with a No. 3 dumbbell (JIS K6301), and marked lines were marked on the surface of the sheet at intervals of 2 cm in the tensile direction. Distance between chucks 20 mm, pulling speed 500 mm / min, temperature 23
It was pulled at a temperature of 65 ° C. and a relative humidity of 65% until it reached an elongation of 500%, and held in that state for 10 minutes. After removing the force, the sample was allowed to stand for 10 minutes and the interval between the marked lines was measured. The difference between the marked line intervals before and after the pulling was determined by the ratio (%) to the marked line interval before the pulling (2 cm), which was taken as the permanent elongation.

(Toxicity test) 300m physiological saline at 70 ° C
30 g of the sheet was immersed in 1 for 12 hours to obtain a test solution, and 1 ml of this test solution was intravenously injected to each of 10 male mice,
The state of the male mouse after 5 days was observed. ○ ・ ・ All mice survive without any abnormality. × ... All or part of the mouse has abnormalities such as convulsions, difficulty walking, discoloration of skin, and death.

(Degradation test) A 2 mm thick sheet was punched out into a No. 3 type dumbbell (JIS K6301) and left in a gear oven at 120 ° C for 30 minutes, and then the tensile strength at break was determined in the same manner as the tensile test. The ratio to the tensile strength obtained in the tensile test was calculated and expressed. The larger the ratio value, the more difficult it is to deteriorate.

Example 1 96 mol% of diene monomer units cis-1,4-bonded with adjacent monomer units, 1,2-bonded or 3,
4-mol total amount of diene-based monomer units bonded 4 mol%
And polybutadiene 20 having a number average molecular weight of 180,000
Parts by weight: 96 mol% of cis-1,4-bonded diene monomer unit and 4 mol% of trans-1,4-bonded diene monomer unit and number average molecular weight 80
80 parts by weight of 10,000 polyisoprene; 0.1 parts by weight of 1,3-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane; 2,5-di-t-butylhydroquinone 0.3. Parts by weight and lecithin 0.5 parts by weight were added to tetrahydrofuran and dissolved to obtain a solution of the medical material composition having a concentration of 10% by weight.

150 ml of this solution was cast on a petri dish having a diameter of 10 cm, and allowed to stand in a nitrogen stream to evaporate tetrahydrofuran to obtain a disk-shaped solid material. Then, the disk-shaped solid material was pressed using a pressing machine. A sheet (medical molded article) having a thickness of 2 mm was obtained by crosslinking at 125 ° C. for 30 minutes under a pressure of 20 atm. The evaluation results of this sheet are shown in Table 2.

Examples 2 to 6 and Comparative Examples 1 to 6 Medical treatment was carried out in the same manner as in Example 1 except that the diene polymers having the formulations shown in Tables 1 and 3 or the compounding formulations shown in Tables 2 and 4 were used. A material composition and a sheet were obtained. The evaluation results of these sheets are shown in Tables 2 and 4.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

[Table 4]

Example 7 The solution of the medical material composition obtained in Example 1 was added with a diameter of 1.
A Teflon-coated stainless steel rod having a length of 8 mm and a length of 100 mm was immersed, the solution was attached to the rod, the rod was lifted from the solution, and allowed to stand at room temperature to evaporate and remove tetrahydrofuran.
Further, it was left in an incubator at 130 ° C for 4 hours for crosslinking,
A tube (medical molded article) with one end closed was obtained. This tube was fitted to cover one end opening of a commercially available catheter to obtain a balloon catheter. After inserting this balloon catheter from the vena cava of the goat to the vicinity of the right atrium, physiological saline is put into the catheter and the balloon is inflated to a diameter of 1 cm, left to stand for 10 minutes, then deflated and then 1 hour from deflation. After the lapse of time, the balloon catheter was taken out from the vena cava, and the surface of the balloon portion was visually observed. As a result, no thrombus was formed on the surface.

Comparative Example 7 The same as Example 7 except that the material composition obtained in Comparative Example 1 was used in place of the medical material composition used in Example 7 (obtained in Example 1). A balloon catheter was obtained by observing the generation state of thrombus in the same manner as in Example 7. A large amount of thrombus adhered to the balloon portion.

From the above, a material composition containing the diene polymer (a) having a molecular weight of less than 20,000 (Comparative Example 1)
It can be seen that the molded product has a large permanent elongation and that thrombus is remarkably generated. It can be seen that the material composition containing the diene polymer (a) having a molecular weight of more than 250,000 (Comparative Example 2) cannot be used because the compatibility of the polymer decreases. In the material composition (Comparative Example 3) containing the diene polymer (b) having a molecular weight of less than 300,000, the molded article has a large permanent elongation and a molecular weight of 2,000,000.
It can be seen that the material composition (Comparative Example 4) containing more than 0 diene polymer (b) cannot be used because the compatibility of the polymer decreases. In addition, adjacent monomer units and 1,
A material composition (Comparative Example 5) using the diene polymer (a) in which the total amount of the 2-bonded or 3,4-bonded diene monomer units is less than 0.2 mol% is a molded product. It is found that the material composition (Comparative Example 6) using the diene polymer (a) exceeding 20 mol% has a lower tensile strength and elongation.

On the other hand, according to the present invention, it can be seen that a molded product having high tensile strength and elongation and low permanent elongation can be obtained. In particular, it can be seen that a medical material composition containing a compound selected from alkylhydroquinone or a lipid can obtain a molded product with a particularly small permanent elongation and a balloon catheter with less thrombus generation. .

Claims (2)

[Claims] 1. A number average molecular weight of 20,000 to 250,000.
No. 00 diene polymer (a) 5 to 50 parts by weight, number average molecular weight 300,000 to 2,000,000 diene polymer (b) 95 to 50 parts by weight (however, diene polymer (a) The total amount of the diene polymer (b) and the diene polymer (b) is 100 parts by weight) and 0.01 to 1 part by weight of an organic peroxide as essential components, and the diene polymer (a) and the diene polymer ( Of all the diene-based monomer units contained in b), the total amount of 1,2-bonded or 3,4-bonded diene-based monomer units with the adjacent monomer units is 0.2. ˜20 mol%, the amount of the diene-based monomer unit bonded to the adjacent monomer unit by a cis-1,4-bond is 80 to 99.8 mol%, and It is characterized in that the amount of the diene-based monomer unit bonded with trans-1,4-bond is 0 to 19.8 mol%. A medical material composition. 2. A medical molded article obtained by crosslinking the medical material composition according to claim 1.