JPH0857037A - Medical material composition, manufacture thereof, and medical molding - Google Patents

Abstract

PURPOSE: To provide a medical molding having low toxicity, large tearing strength and tensile strength and elongation, and small permanent elongation by using a polyurethane made of a specific quantity of a chain extending agent in a medical material composition adaptable for the portion requiring a high expansion ratio such as a balloon. CONSTITUTION: This medical material composition contains a multi-functional isocyanate (Is), a compound (b) having the molecular weight of 700-3000 and two or more functional groups making a polyaddition reaction to the Is group, and a compound (c) having the molecular weight of 500 or below and two or more functional groups making a polyaddition reaction to the Is group as essential constituents. The quantity of the functional groups making a polyaddition reaction to the Is group in the compound (b) is set to 60-90mol against the Is group of 100mol in the multi-functional Is, and the quantity of the functional groups making a polyaddition reaction to the Is group in the compound (c) is set to 5-35mol against the Is group of 100mol in the multi- functional Is. The total quantity of the functional groups making a polyaddition reaction to the Is group in both compounds (b), (c) is set to 80-95mol.

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 particularly, it can be applied to a portion of a catheter such as a balloon requiring a high expansion / contraction ratio, has low toxicity, tear strength and tensile strength. The present invention relates to a medical molded article having high strength and low 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 a small amount of protein, it has recently been found that when a molded product made from natural rubber is used, a bio-allergic reaction occurs.
Therefore, development of a medical material composition that replaces natural rubber has been desired. Thermoplastic polyurethane is known as a natural rubber substitute material. This thermoplastic polyurethane is
It is a polymer obtained by polyaddition reaction of diisocyanate and diol or diamine at substantially equal molar ratios. However, when this thermoplastic polyurethane is applied to a portion of a balloon catheter that requires a high expansion and contraction rate of 500% or more, when the balloon is deflated, wrinkles are formed on the balloon surface and the blood flow becomes stagnant. Therefore, it is known that a large amount of thrombus is generated. Further, this thermoplastic polyurethane is not suitable as a substitute material for natural rubber because the molded product has a smaller tensile strength and elongation than natural rubber.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is applicable to a part requiring a high expansion / contraction ratio, has low toxicity, has high tear strength, tensile strength and elongation, and has a small permanent elongation. The object is to provide a medical material composition for obtaining this molded product. The present inventors have conducted extensive studies to achieve this object, and as a result, found that the above object can be achieved by using a polyurethane obtained by using a specific amount of a chain extender, and based on this finding, Then, the present invention was completed.

[0004]

According to the present invention, a polyfunctional isocyanate (a) having a molecular weight of 700 to 30 is thus obtained.
00 is a compound (b) having two or more functional groups capable of polyaddition reaction with an isocyanate group and a compound (c) having a molecular weight of 500 or less and having two or more functional groups capable of polyaddition reaction with an isocyanate group as essential components. The amount of the functional group which undergoes a polyaddition reaction with the isocyanate group in the compound (b) is 60 to 90 moles based on 100 moles of the isocyanate group in the polyfunctional isocyanate (a), The amount of the functional group which undergoes a polyaddition reaction with the isocyanate group is 5 to 35 mols based on 100 mols of the isocyanate group in the polyfunctional isocyanate (a), and the amount of the functional group in the compound (b) and the compound (c) is The total amount of the functional groups that undergo a polyaddition reaction with the isocyanate group is 80 to 95 moles based on 100 moles of the isocyanate groups in the polyfunctional isocyanate (a). There is provided. Further, according to the present invention, there is provided a medical molded article obtained by polyaddition reaction of the polyfunctional isocyanate (a), which constitutes the above-mentioned medical material composition, and the compound (b) and the compound (c). .

The medical material composition of the present invention comprises, as essential components, a polyfunctional isocyanate (a) and compounds (b) and (c) having a functional group capable of undergoing a polyaddition reaction with an isocyanate group having a specific molecular weight. Is.

The polyfunctional isocyanate (a) used in the medical material composition of the present invention is a compound having two or more isocyanate groups. Specifically, an aromatic isocyanate such as diphenylmethane diisocyanate, naphthalene diisocyanate, tolylene diisocyanate, tetramethylxylene diisocyanate, xylene diisocyanate; dicyclohexane diisocyanate,
Aliphatic isocyanates such as dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate can be mentioned. Of these polyfunctional isocyanates, diphenylmethane diisocyanate is preferable because it is highly safe for living organisms.

The compound (b) used in the medical material composition of the present invention has two or more functional groups that undergo a polyaddition reaction with an isocyanate group. The functional group that undergoes a polyaddition reaction with the isocyanate group is a functional group having active hydrogen.
Specific examples thereof include a hydroxyl group and an amino group. In addition, active hydrogen refers to a hydrogen atom bonded to an oxygen atom or a nitrogen atom which forms part of a compound. The compound (b) having a functional group that undergoes a polyaddition reaction with an isocyanate group is
The lower limit of its molecular weight is 700, preferably 800, and the upper limit is 3000, preferably 1500. 7
If it is less than 00, the tensile strength and elongation of the molded product obtained by crosslinking the medical material composition will be small. On the other hand, if it exceeds 3000, the permanent elongation of the medical molded article increases. The molecular weight of the compound (b) is a value determined by using gel permeation chromatography with tetrahydrofuran as a carrier and based on a calibration curve of the weight average molecular weight of standard polystyrene.

Specific examples of the compound (b) having a functional group that undergoes a polyaddition reaction with an isocyanate group include polyether polyols such as polyoxytetramethylene glycol, polyethylene glycol, polypropylene glycol and alkylene oxide copolymerized polyols; adipic acid. Examples thereof include dehydration condensates of polyhydric carboxylic acids such as and polyhydric alcohols such as glycol and triol; polyester polyols such as polycarbonate diol; and polybutadiene polyol. The compound (b) is one or two.
A combination of two or more species can be used. Of these compounds (b), polyethers, particularly polyoxytetramethylene glycol, are preferable because they are biocompatible and safe.

The amount of the compound (b) is 60 to 60 with respect to 100 mol of the isocyanate group in the polyfunctional isocyanate (a) such that the amount of the functional group which undergoes the polyaddition reaction with the isocyanate group in the compound (b) is large. The amount is 90 mol, preferably 70 to 80 mol. When it is less than 60 mol, the permanent elongation of the medical molded article becomes large and the elongation becomes small. On the contrary, 9
If it exceeds 0 mol, the permanent elongation increases and the tensile strength decreases.

The compound (c) used in the medical material composition of the present invention is a compound having two or more functional groups capable of undergoing a polyaddition reaction with an isocyanate group.

The compound (c) has a molecular weight of 500 or less, preferably 300 or less. If more than 500 is used, the strength of the medical molded article is reduced. The molecular weight is a value obtained by measurement using a mass spectrum.

Specific examples of the compound (c) include ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, methyleneglycoside, and methoxy. Polyols such as sugars; polyols such as ethylenediamine, hexamethylenediamine, N, N'-diisopropylmethylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, 1,3,5-triaminobenzene; oximes And so on. Compound (c)
Of these, trimethylolpropane, ethylenediamine or 1,4-butanediol is preferably used because the use of these increases the strength of the medical molded article.

The amount of the compound (c) is such that the amount of the functional group which undergoes a polyaddition reaction with the isocyanate group in the compound (c) is 5 to 100 moles of the isocyanate group in the polyfunctional isocyanate (a). It is in the range of 35 mol, preferably 5 to 25 mol. If it is less than 5 mol, the tensile strength of the medical molded product will be small, and if it exceeds 35 mol, the elongation of the medical molded product will be small.

The compound (c) can be used in combination of two or more kinds. Those having two functional groups that undergo a polyaddition reaction with an isocyanate group (hereinafter referred to as a bifunctional compound (c
It may be 1). ) And a compound having three or more functional groups that undergo a polyaddition reaction with an isocyanate group (hereinafter sometimes referred to as a trifunctional or higher functional compound (c2)), the tear strength and the tensile strength increase, It is also preferable because the permanent elongation becomes small. In particular, it is preferable to use ethylenediamine or 1,4-butanediol as the bifunctional compound (c1), trimethylolpropane as the trifunctional or higher functional compound (c2), and to combine them.

When the bifunctional compound (c1) and the trifunctional or higher functional compound (c2) are used in combination, the amount of the bifunctional compound (c1) is determined by the polyaddition reaction with the isocyanate group in the bifunctional compound (c1). The amount of the functional groups to be added is usually 50 to 95 mol%, preferably 70 to 90 g mol% based on the total amount of the functional groups that undergo a polyaddition reaction with the isocyanate group in the compound (c1) and the compound (c2). It becomes the ratio of. If it is less than 50 g mol%, the elongation and tear strength of the molded medical product will be small. On the other hand, when it exceeds 95 mol%, the effect of increasing the tear strength and the tensile strength of the medical molded article is lost. The amount of the trifunctional or higher functional compound (c2) is such that the amount of the functional group which undergoes a polyaddition reaction with the isocyanate group in the trifunctional or higher functional compound (c2) is equal to that of the isocyanate group in the compound (c1) or in the compound (c2). It is in the range of usually 5 to 50 mol%, and preferably 10 to 30 mol% with respect to the total amount of the functional groups that undergo the polyaddition reaction.

The total amount of the compound (b) and the compound (c) is such that the amount of the functional group which undergoes the polyaddition reaction with the isocyanate group in the compound (b) and the compound (c) is the polyfunctional isocyanate (a). 8 per 100 moles of isocyanate groups in
It is in the range of 0 to 95 mol, preferably 85 to 95 mol. If it deviates from this range, the permanent elongation will increase.

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 is not limited by its properties, but a solution of an organic solvent is preferable because it has excellent moldability. The organic solvent used for the solution is
Usually, the one which is not compatible with water or the aqueous solution obtained by being compatible with water has a pH of 6 to 8. Specific examples thereof include aromatic hydrocarbons such as benzene, toluene and xylene; ethers such as tetrahydrofutan and cyclohexanone; ketones such as methyl ethyl ketone and isobutyl ethyl ketone; and aliphatic hydrocarbons such as hexene and hexane.

The medical material composition of the present invention is not limited by its preparation method. The preparation is usually carried out by mixing the polyfunctional isocyanate (a) and the compound (b) and then adding the solution of the compound (c) or mixing the compound (b) and the compound (c), A method such as adding the functional isocyanate (a) or mixing the polyfunctional isocyanate (a) and a part of the compound (b), and then adding the rest of the compound (b) and the compound (c). Done in. Among these preparation methods, after mixing the polyfunctional isocyanate (a) and a part of the compound (b), the preparation method of adding the remainder of the compound (b) and the compound (c) to the mixture has a tensile strength It is suitable for increasing the size.

After mixing the polyfunctional isocyanate (a) and a part of the compound (b) (first stage), the rest of the compound (b) and the compound (c) are added thereto (second step). (Stage) In the preparation, the amount of the compound (b) mixed with the polyfunctional isocyanate (a) in the first stage is such that the amount of the functional group capable of polyaddition reaction with the isocyanate group in the compound (b) is The ratio is usually 35 to 65 mol, preferably 40 to 60 mol, based on 100 mol of the isocyanate group in the polyfunctional isocyanate (a). If it is less than 35 mol or exceeds 65 mol, the effect of increasing the tensile strength and the like becomes small. It is preferable to heat at the time of mixing the polyfunctional isocyanate (a) and a part of the compound (b) or after the mixing. Upon heating, the polyfunctional isocyanate (a) and a part of the compound (b) undergo a polyaddition reaction. The heating temperature is usually 50 to 100 ° C., preferably 60 to 90.
° C. It takes time to bond below 50 ° C,
On the other hand, if the temperature exceeds 100 ° C, the second step operation becomes difficult and the molded article for medical use has a large permanent elongation and a small tensile strength, tear strength and elongation. The heating time is usually 10
It is 480 minutes, preferably 30 to 120 minutes. The rest of the compound (b) and the compound (c) are usually added after cooling after the above heating. The amount of the balance of the compound (b) is usually 5 with respect to 100 mol of the isocyanate group in the polyfunctional isocyanate (a), the amount of the functional group which undergoes a polyaddition reaction with the isocyanate group in the compound (b). More than a mole,
The amount is preferably 10 mol or more.

A medical molded article can be obtained by polyaddition reaction of the polyfunctional isocyanate (a) constituting the medical material composition of the present invention with the compound (b) and the compound (c). The polyaddition reaction is carried out either after or before molding the medical material composition, preferably after molding. The molding is usually performed by a melt molding method, a casting molding method, a dipping molding method, preferably a dipping molding method. For example, in the dipping molding method, a mold having a desired shape is immersed in an organic solvent solution of a medical material composition,
Pull up and leave.

The polyaddition reaction is carried out by heating the medical material composition. The heating is performed by removing the amount of volatile components such as a solvent and a dispersion medium contained in the medical material composition to 3% by weight or less, preferably 0.5% by weight or less, based on the medical material composition. Is preferable. 3% by weight
If it exceeds the range, the composition upon heating foams to form voids in the molded product, which is not preferable. The heating temperature is usually 80
˜170 ° C., preferably 100˜130 ° C. 80
If the temperature is lower than 0 ° C, the crosslinking reaction is difficult, and if the temperature exceeds 170 ° C, a decomposition reaction occurs and the molded product tends to deteriorate. The heating time varies depending on the shape of the molded product, but is usually 12
~ 120 hours, preferably 24-72 hours. 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. A catalyst may be added to promote crosslinking. Examples of catalysts include monoamines and organometallic catalysts. After the polyaddition reaction, it is preferable that the polyaddition reaction product (medical molded product) is usually aged for 4 to 14 days at room temperature. By aging, the permanent elongation of the medical molding becomes smaller.

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 such as a balloon portion of a balloon catheter that requires a high expansion / contraction rate.

The preferred embodiments of the present invention are shown below. (1) Polyfunctional isocyanate (a), molecular weight 700-3
At 000, the number of functional groups that undergo a polyaddition reaction with isocyanate groups is 2
A compound (b) having two or more compounds and a compound (c) having two or more functional groups having a molecular weight of 500 or less and capable of undergoing a polyaddition reaction with an isocyanate group, as an essential component, and a polyaddition reaction with an isocyanate group in the compound (b). The amount of the functional group to be added is 60 to 90 mol with respect to 100 mol of the isocyanate group in the polyfunctional isocyanate (a), and the amount of the functional group that undergoes a polyaddition reaction with the isocyanate group in the compound (c) is The total amount of the functional groups in the polyaddition reaction with the isocyanate group in the compound (b) and the compound (c) is 5 to 35 moles based on 100 moles of the isocyanate group in the polyfunctional isocyanate (a). 80-95 mol of the isocyanate group in the polyfunctional isocyanate (a), relative to 100 mol of the isocyanate group. (2) The medical material composition according to (1) above, wherein the polyfunctional isocyanate (a) is diphenylmethane diisocyanate. (3) The medical material composition according to (1) above, wherein the compound (b) is a polyether, preferably polyoxytetramethylene glycol. (4) The medical material composition according to (1) above, wherein the compound (c) is trimethylolpropane, ethylenediamine or 1,4-butanediol. (5) Compound (c) is a combination of a compound (c1) having two functional groups that undergo a polyaddition reaction with an isocyanate group, and a compound (c2) having three or more functional groups that undergo a polyaddition reaction with an isocyanate group. The medical material composition according to (1) above, which is used. (6) The amount of the functional group which undergoes a polyaddition reaction with the isocyanate group in the bifunctional compound (c1) depends on the total amount of the functional groups which undergo a polyaddition reaction with the isocyanate group in the compound (c1) and the compound (c2). On the other hand, the amount of the functional group which undergoes polyaddition reaction with the isocyanate group in the trifunctional or higher functional compound (c2) is 50 to 95 mol%, and the amount of the functional group undergoes the polyaddition reaction with the isocyanate group in the compound (c1) and the compound (c2). 5 for the total amount of functional groups
The medical material composition according to (5) above, wherein the bifunctional compound (c1) and the trifunctional or higher functional compound (c2) are used in an amount of about 50 mol%. (7) The bifunctional compound (c1) is ethylenediamine or 1,4-butanediol, and the trifunctional or higher functional compound (c
2) is trimethylolpropane, The medical material composition according to the above (5) or (6), wherein (8) The medical use according to the above (1), wherein the polyfunctional isocyanate (a) and a part of the compound (b) are mixed, and then the rest of the compound (b) and the compound (c) are added and stirred. Method for preparing material composition. (9) The amount of the functional group which undergoes a polyaddition reaction with the isocyanate group in the compound (b) is large at a ratio of 35 to 65 mol with respect to 100 mol of the isocyanate group in the polyfunctional isocyanate (a). After mixing the functional isocyanate (a) and the compound (b) and heating, the amount of the isocyanate group in the compound (b) and the weight of the isocyanate group in the compound (b) are 100% relative to the amount of the isocyanate group in the polyfunctional isocyanate (a). The amount of the functional group to undergo the addition reaction is 5 to 55 mol (however, the total amount of the functional group to undergo the polyaddition reaction with the isocyanate group in the compound (b) is 60 to 90 mol) and the compound (c). The preparation method according to the above (8), wherein the compound (b) and the compound (c) are added in such a proportion that the amount of the functional group that undergoes a polyaddition reaction with the isocyanate group is 5 to 35 mol. (10) The preparation method according to the above (9), wherein the heating temperature is 50 to 100 ° C. (11) A medical molded article obtained by polyaddition reaction of the polyfunctional isocyanate (a) constituting the medical material composition of (1) with the compound (b) and the compound (c). (12) The medical material composition according to (1) above, at 80 to 170 ° C.
The molded article for medical use according to the above (11), which is obtained by heating to a polyaddition reaction. (13) The medical molded article according to (11) or (12), which is aged for 4 to 14 days at room temperature after the polyaddition reaction.

[0025]

The molded article obtained by crosslinking the medical material composition of the present invention has a high antithrombotic property even when applied to a portion requiring a high expansion / contraction rate, and is therefore suitable for use in medical balloons. can do.

[0026]

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 used in this embodiment will be described below. (Tensile test) A 2 mm thick sheet was used as a No. 3 dumbbell (JI
Stamped with SK6301), and this is JIS K-63
01, chuck distance 20 mm, pulling speed 50
The elongation at tensile rupture and the tensile strength were determined under the conditions of 0 mm / min, temperature 23 ° C., and relative humidity 65%.

(Permanent elongation) A sheet having a thickness of 2 mm was punched with a No. 3 type 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.

(Tear Test) A 2 mm thick sheet is
A rectangular piece of m × 12 mm was punched into a shape having a right-angled triangle with a depth of 2 mm in the center of the long side, and this was punched in the same manner as in the above tensile test to determine the strength at tearing and breaking.

(Antithrombogenicity) A balloon catheter was inserted from the vena cava of a goat to the vicinity of the right atrium, and physiological saline was injected into the catheter to inflate the balloon to a diameter of 1 cm, and allowed to stand for 10 minutes and then deflated. And shrink from 3
After 0 minutes, the balloon catheter was pulled out from the vena cava, and the surface of the balloon portion was visually inspected for the presence of thrombus. ◯: No thrombus has occurred. X: Thrombus had occurred.

Example 1 A reactor purged with nitrogen was charged with 100 mmol of diphenylmethane diisocyanate, the temperature was raised to 80 ° C., and then polyoxytetramethylene glycol having a molecular weight of 1000 was added.
By adding millimole, polyaddition reaction was carried out for 1 hour (first stage), and cooled to 25 ° C. to obtain a polyaddition product. The molecular weight of this polyadduct was about 1500. Then, the temperature of the reactor containing the polyaddition product was raised to 60 ° C., and 25 mmol of polyoxytetramethylene glycol having a molecular weight of 1,000, 1,4
-Butanediol (15 mmol) and tetrahydrofuran (290 g) were added to the reactor and stirred for 10 hours (second stage), and then the viscosity was adjusted to 2000 cps to obtain a medical material composition.

45 ml of this solution was poured into a petri dish having a diameter of 100 mm, and tetrahydrofuran was removed under a nitrogen stream (remaining amount of tetrahydrofuran was 0.2%) to obtain a disk-shaped solid material. Then, the disk-shaped solid material was heated at 110 ° C. The sample was left for 24 hours in the incubator for 24 hours and left at room temperature for 6 days for aging to obtain a sheet (medical molded article) having a thickness of 2 mm. The evaluation results of this sheet are shown in Table 1.

Further, a Teflon-coated stainless steel rod having a diameter of 1.8 mm and a length of 100 mm was dipped, the solution was attached to the rod, the rod was lifted from the solution and left at room temperature to evaporate and remove tetrahydrofuran. Further, it was left in a thermostat at 110 ° C. for 24 hours for crosslinking, and left for 7 days at room temperature for aging to obtain a 0.15 mm-thick tube (medical molded article) with one end blocked. Length of this tube 1.3
The catheter was cut into a piece having a diameter of 1.8 mm and attached to the tip of a commercially available catheter having a diameter of 1.8 mm so as to cover the balloon side hole. The evaluation results of the antithrombotic property of this balloon catheter are shown in Table 1.

Examples 2 to 17 and Comparative Examples 1 to 6 Medical use was carried out in the same manner as in Example 1 except that the kinds or amounts of the compounds used in Example 1 were changed to those shown in Table 1, Table 2 or Table 3. A material composition, a sheet and a balloon catheter were obtained. The evaluation results of the seat and balloon catheter are shown in Table 1,
The results are shown in Table 2 or Table 3.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

From the above, when the amount of the functional group which undergoes the polyaddition reaction with the isocyanate group in the compound (b) is less than 60 mol (Comparative Example 1), the permanent elongation of the medical molded article becomes large, and the elongation also increases. On the contrary, when it exceeds 90 mol (Comparative Example 2), the permanent elongation becomes large and the tensile strength becomes small. When the amount of the functional group which undergoes the polyaddition reaction with the isocyanate group in the compound (c) is less than 5 mol (Comparative Example 3), the tensile strength of the medical molded article becomes small, and when it exceeds 35 mol (Comparative). It can be seen that in Example 4), the elongation of the medical molded product is small. Further, when the molecular weight of the compound (b) is less than 700, the tensile strength and elongation of the molded product become small, and conversely, when the molecular weight of the compound (b) exceeds 3000, the permanent elongation of the medical molded product becomes large. I understand.

On the other hand, it can be seen that the molded product obtained by crosslinking the medical material composition of the present invention has a large tear strength, tensile strength and elongation and a small permanent elongation, and is unlikely to cause thrombus even when applied to the balloon portion. . In particular, when a compound (c1) having two functional groups that undergo a polyaddition reaction with an isocyanate group and a compound (c2) having three or more functional groups that undergo a polyaddition reaction with an isocyanate group are used in combination (implementation) It can be seen that in Examples 6, 15 and 16) the tear strength and tensile strength are even higher and the permanent set is lower.

Claims (3)

[Claims] 1. A polyfunctional isocyanate (a) having a molecular weight of 7
A compound (b) having two or more functional groups which undergo polyaddition reaction with an isocyanate group at 0 to 3000 and a compound (c) having two or more functional groups having a molecular weight of 500 or less and capable of polyaddition reaction with an isocyanate group are essential. As a component, the amount of the functional group which undergoes a polyaddition reaction with the isocyanate group in the compound (b) is 60 to 90 moles based on 100 moles of the isocyanate group in the polyfunctional isocyanate (a), and the compound (c) The amount of the functional group which undergoes a polyaddition reaction with the isocyanate group in the compound (b) and the compound (c) is 5 to 35 mol, based on 100 mol of the isocyanate group in the polyfunctional isocyanate (a). The total amount of the functional groups that undergo a polyaddition reaction with the isocyanate group in the polyfunctional isocyanate (a) is from 80 to 100 mol per 100 mol of the isocyanate group in the polyfunctional isocyanate (a).
A medical material composition, which is 95 mol. 2. The polyfunctional isocyanate (a) and a part of the compound (b) are mixed, and then the rest of the compound (b) and the compound (c) are added thereto. A method for preparing the described medical material composition. 3. A medical molded article obtained by polyaddition reaction of a polyfunctional isocyanate (a) constituting the medical material composition according to claim 1 with a compound (b) and a compound (c).