JPH10179687A - Medical stopper and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical stopper excellent in liquid leakage resistance, needle sticking property, re-sealing property, cost performance and the like, and a method for producing the same. SOLUTION: An elastic plug material 3 made of a non-vulcanized thermoplastic elastomer is integrally formed at one end of a cylindrical body 2 mainly composed of a thermoplastic resin, and the elastic plug material 3 is formed into a tubular shape such as a syringe needle. In the medical plug 1 used to penetrate an object, the elastic plug material 3 has an outer peripheral portion 31 fused to the cylindrical body 2 and a central portion 32 through which the tubular object penetrates. And the method of manufacturing the medical stopper, wherein the length of the outer peripheral portion 31 is shorter than that of the central portion 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical stopper and a method for producing the same, and more particularly, to a medical stopper having excellent liquid leakage resistance, needle sticking property, resealability, and cost performance. The present invention relates to a stopper and a method for producing the stopper. The medical stopper of the present invention is suitably used for blood transfusion containers, drug solution containers, mixed injection stoppers for hemodialysis, peritoneal dialysis, and the like.

[0002]

2. Description of the Related Art A conventional medical stopper has been manufactured by separately molding a cylindrical body and an elastic stopper, and assembling them. For example, JP-A-63-268623 discloses that
A method of applying ultrasonic vibration to weld a cylindrical body and an elastic plug material is disclosed. Also, JP-A-63-317470.
And JP-A-63-296557 disclose a method of sandwiching an elastic plug material and welding a cylindrical body. In addition to these, there has been proposed one in which a heat treatment is performed to prevent the elastic plug material from falling off and the cylindrical body is contracted.

[0003] However, forming the cylinder and the elastic plug material separately and assembling them separately requires a great deal of cost, and furthermore, the obtained medical plug has a strong rigidity between the cylinder and the elastic plug material. Since the adhesive does not adhere to the container, there is a problem that the contents of the container leak, or the elastic stopper comes off the cylinder when the injection needle is pierced into the elastic stopper or when the pressure of the container increases. .

[0004] The integral molding of the cylindrical body and the elastic plug material is disclosed in, for example, Japanese Patent Application Laid-Open No. 8-258857. FIG. 3 is a cross-sectional view of a medical stopper obtained by this conventional technique.
The technique involves injection-molding a cylindrical body 2 made of a polypropylene resin, and then completely and fusion-molding an elastic plug material 3 made of a thermoplastic elastomer integrally with the cylindrical body 2, and using this as a medical stopper. It is.

However, the above-mentioned Japanese Patent Application Laid-Open No. Hei 8-2588
In the medical stopper obtained according to Japanese Patent No. 57, distortion occurs between the cylindrical body and the elastic body, and the performance (liquid leakage resistance, needle sticking property, resealing property, etc.) required for the medical stopper is obtained. Absent. In addition, this distortion can create a cavity in the center of the plug, as shown in FIG.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems of the medical plug disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Hei 8-258857, to provide a liquid leakage resistance, a needle sticking property and a resealability. Another object of the present invention is to provide a medical stopper which is excellent in cost and can be obtained at low cost, and a method for producing the same.

[0007]

As a result of intensive studies, the present inventor has been able to solve the above-mentioned conventional problems. That is, the present invention is obtained by integrally molding an elastic stopper made of a non-vulcanized thermoplastic elastomer at one end of a cylindrical body mainly composed of a thermoplastic resin, and the elastic stopper is provided with a tubular member such as an injection needle. In the medical stopper used to penetrate, the elastic plug material has an outer peripheral portion that is fused to the cylindrical body, and a central portion that penetrates the tubular object, and the elastic plug material in the penetration direction of the tubular object. A medical plug according to the present invention is characterized in that the length of the outer peripheral portion is shorter than that of the central portion.

The present invention also provides the medical plug described above, wherein the length of the outer peripheral portion in the penetration direction of the tubular object is shorter by 2 to 98% than that of the central portion.

Further, according to the present invention, the gap or the non-fused portion formed because the length of the outer peripheral portion in the penetrating direction of the tubular object is shorter than that of the central portion is reduced to the inner side of the elastic plug material. The medical stopper provided in the above is provided.

Further, the present invention comprises a cylindrical body mainly composed of a thermoplastic resin, and an elastic plug material made of a non-vulcanized thermoplastic elastomer, wherein a tubular object such as an injection needle is penetrated through the elastic plug material. In the method for manufacturing a medical plug used in the above, the elastic plug material has an outer peripheral portion fused to the cylindrical body, and a central portion through which the tubular object penetrates, and in a penetration direction of the tubular object. It is another object of the present invention to provide a method for manufacturing a medical plug, wherein the cylindrical body and the elastic plug material are integrally formed so that the length of the outer peripheral portion is shorter than that of the central portion.

In the medical plug according to the present invention, the outer peripheral portion fused to the cylindrical body buffers the distortion generated between the cylindrical body and the elastic plug material. Is done.

[0012]

FIG. 1 is a sectional view showing an embodiment of the medical stopper according to the present invention. According to FIG. 1, a medical stopper 1 of the present invention comprises a cylindrical body 2 and an elastic plug material 3, and the elastic plug material 3 has an outer peripheral portion 31 fused to the cylindrical body 2 and a tubular member such as an injection needle. And a central portion 32 through which an object penetrates. The outer peripheral portion 31 has a shorter distance in the penetrating direction of the tubular object than the central portion 32, and has a gap (or a non-fused portion) a
And b are present. Further, in the penetrating direction of the medical stopper 1, for example, a blood transfusion container or the like is attached.

The outer peripheral portion 3 in the penetration direction of the tubular object
The length of 1 is preferably about 2 to 98% shorter than that of the central portion 32, preferably 2 to 80%, and more preferably 2 to 60%.

The cylindrical body 2 of the medical stopper 1 of the present invention is made of a thermoplastic resin (A) described below and an elastic stopper material 3.
It is preferable to use a non-vulcanized thermoplastic resin composition (B) that can be fused with the thermoplastic resin (A). These components are described in detail below.

As the thermoplastic resin (A) preferably used for the cylindrical body, polyolefin resin, styrene resin, polyamide, polycarbonate, polyacrylic acid,
Examples thereof include polyacrylate, polymethacrylic acid, polymethacrylate, polysulfone, and polyethersulfone. Among them, polyolefin resin,
Styrene resins are preferred, and polyolefin resins are particularly preferred.

Specifically, polyolefin resins include low-density polyethylene resin, linear low-density polyethylene resin, medium-density polyethylene resin, high-density polyethylene resin, and polypropylene resin (these are homopolymers,
Block- or random copolymer), ethylene-vinyl acetate copolymer, ethylene-
Acrylic ester copolymers, ionomer resins, poly-4-methylpentene-1 resins, and the like are included. In addition, as the styrene resin, general polystyrene resin,
Impact-resistant polystyrene resin, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-acrylic rubber-styrene copolymer, acrylonitrile-ethylene propylene rubber-styrene copolymer, modified polyphenylene ether resin and the like. Can be

Next, the thermoplastic resin composition (B) preferably used for the elastic plug material is a thermoplastic resin composition (B) which can be fused with the thermoplastic resin (A) and contains at least two vinyl aromatic compounds. A hydrogenated block copolymer (a) obtained by hydrogenating a block copolymer consisting of a polymer block (I) mainly composed of at least one polymer block (II) mainly composed of at least one conjugated diene compound. ) Is a preferred thermoplastic resin composition (B).

As such a thermoplastic resin composition (B), 100 to 50 parts by weight of a hydrogenated block copolymer (a) and 0 to 50 parts by weight of a polyolefin resin (b) [where (a) + (B) = 100 parts by weight] and (c) 1 to 200 parts by weight of an oil.

Examples of the block copolymer in the hydrogenated block copolymer (a) include the above-mentioned I-II and II-II-II
And a block copolymer of a vinyl aromatic compound-conjugated diene compound having a structure such as -I or I-II-II-II-I.

Here, as the polymer block (I) mainly composed of at least two vinyl aromatic compounds, a homopolymer of a vinyl aromatic compound or a vinyl aromatic compound exceeding 50% by weight, preferably 70% by weight. Copolymers containing at least% by weight are exemplified. Examples of such a vinyl aromatic compound include styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene, and the like, and one or more of these can be selected. Among them, styrene is preferred.

The content of the polymer block (I) in the hydrogenated block copolymer (a) is preferably 5 to 70% by weight, more preferably 10 to 60% by weight, particularly preferably 15 to 40% by weight. is there. If the content of the polymer block (I) is less than 5% by weight, the required rubber elasticity cannot be obtained, and if it exceeds 70% by weight, it tends to be too hard.

The polymer block (II) mainly composed of at least one conjugated diene compound may be a homopolymer of isoprene or 50% by weight of isoprene.
A copolymer containing more than 70% by weight, preferably a homopolymer of polybutadiene, or a copolymer containing more than 50% by weight of polybutadiene, preferably 70% by weight or more is included. Preferably, more than 50% by weight of a homopolymer of isoprene or isoprene,
Preferably, it is a copolymer containing 70% by weight or more.

Here, the microstructure of the isoprene portion contained in the polymer block (II) is preferably such that the 1,4-microstructure is 70 to 100% by weight. If the 1,4-microstructure is less than 70% by weight, oil bleeds is not preferred. More preferably, 90-1
00% by weight. The 1,4-micro structure of isoprene specifically means a structure represented by the following formula.

[0024]

Embedded image

When the polymer block (II) is polybutadiene, the 1,2-microstructure of the butadiene portion is preferably 20 to 50% by weight. If the 1,2-microstructure is less than 20% by weight, oil bleeds is not preferred. On the other hand, if it exceeds 50% by weight,
After hydrogenation, the rubbery properties are lost and the impact strength is undesirably reduced. More preferably, it is 35 to 45% by weight. In addition, 1,2- of butadiene part of polybutadiene
The microstructure specifically means a structure represented by the following formula.

[0026]

Embedded image

Here, at least 90% of the aliphatic double bonds based on at least one conjugated diene compound such as polyisoprene or polybutadiene are preferably hydrogenated. By hydrogenating in this way,
A polymer block mainly composed of isoprene or butadiene can be morphologically converted into an olefinic compound polymer block. If the hydrogenation rate is less than 90%,
Since the alternating polymerizability of ethylene and propylene is lost and the olefin property is impaired, the thermal adhesion to the thermoplastic resin is poor, which is not preferable. In addition, heat resistance is poor, which is not preferable.

The weight average molecular weight of the hydrogenated block copolymer (a) is from 50,000 to 550,000, preferably 5
The range of 0000 to 400,000 is good. If the weight average molecular weight is 50,000 or less, the mechanical strength of the composition is inferior, which is not preferable. On the other hand, if it exceeds 550,000, the molding processability is inferior, which is not preferable. The molecular weight distribution (weight average molecular weight Mw / number average molecular weight Mn) is
10 or less is good. It is preferably 5 or less, more preferably 2 or less.

The distribution of molecular chains in each of the polymer block (I) mainly composed of at least two vinyl aromatic compounds and the polymer block (II) mainly composed of at least one conjugated diene compound is described. Is not particularly limited, and may be, for example, random, tapered (the monomer component increases or decreases along the molecular chain), partially block-like, or any combination thereof.

The (b) polyolefin resin suitably used in the thermoplastic resin composition (B) in the present invention includes low-density polyethylene resin, linear low-density polyethylene resin, medium-density polyethylene resin, and high-density polyethylene resin. , A polypropylene resin (these may be any of a homopolymer, a block, or a random copolymer), an ionomer resin, a poly-4-methylpentene-1 resin, and the like. Among them, a polypropylene resin is preferable.

The thermoplastic resin composition (B) in the present invention
The component (c) preferably used is an oil, and examples thereof include aromatic rubber softeners and non-aromatic rubber softeners, and include process oils, mineral oil rubber softeners, aroma oils,
Liquid paraffin, paraffinic oil, naphthenic oil and the like are included. Among them, non-aromatic rubber softeners are preferable, and liquid paraffin, paraffin oil and naphthene oil are more preferable. The weight average molecular weight of the oil is preferably from 100 to 2,000. Such an oil component contributes to making it easier to control the flexibility of the composition. In the present invention, as in the prior art,
Oil does not bleed into molded products.

The thermoplastic resin composition (B) in the present invention
Preferably, as described above, the component (b) is added to the composition of the components (a) and (c) as necessary. Here, the mixing ratio of each component in the thermoplastic resin composition (B) is (a) 100 to 5 hydrogenated block copolymers.
0 parts by weight, preferably 100 to 60 parts by weight, (b) 0 to 50 parts by weight of polyolefin resin, preferably 0 to 40 parts by weight
(C) 1 to 200 parts by weight of oil, preferably 5 to 5 parts by weight, with the proviso that (a) + (b) = 100 parts by weight.
180 parts by weight. In the components (a) and (b),
If the amount of the component (a) is less than 50 parts by weight, the mechanical strength is inferior. If the amount of the component (c) is less than 1 part by weight based on 100 parts by weight of the total amount of the components (a) and (b), flexibility cannot be obtained. It is not preferable because the suppression effect is impaired. Hereinafter, the composition of each component will be described in detail.

In the case of the two-component system of the components (a) and (c), the components (c) 1-2
00 parts by weight, preferably 50 to 180 parts by weight.
If the amount of the component (c) is less than 1 part by weight, flexibility cannot be obtained, which is not preferable. On the other hand, if it exceeds 200 parts by weight, the effect of suppressing bleeding of oil is impaired, which is not preferable.

In the case of a three-component system comprising components (a), (b) and (c), 50 to 99 parts by weight, preferably 5 to 99 parts by weight of component (a)
5 to 95 parts by weight, 50 to 1 part by weight of component (b), preferably 45 to 5 parts by weight [provided that (a) + (b) = 100 parts by weight], and 1 to 200 parts by weight of component (c) , Preferably 50 to 180 parts by weight. If the component (b) exceeds 50 parts by weight of the components (a) and (b), the rubbery properties are undesirably impaired.

The thermoplastic resin composition (B) may further contain a polyether block amide or a thermoplastic polyester resin, if necessary, thereby improving oil resistance, heat resistance and heat fusion. This has the effect of doing so. When the polyether block amide is added, 5-200 parts by weight of the thermoplastic resin composition (B) is added.
It is advisable to add parts by weight. Here, the polyether block amide specifically has a structure represented by the following formula.

[0036]

Embedded image HO— (CO—PA—CO—C—PE—O ”n—H wherein PA is a polyamide block (hard segment), PE is a polyether block (soft segment), and n is a repeating unit. Show the unit.]

When a thermoplastic polyester resin is added, it is preferable to add 5-200 parts by weight based on 100 parts by weight of the thermoplastic resin composition (B). here,
Examples of the thermoplastic polyester resin include a polyester segment obtained from an aromatic dicarboxylic acid and a short-chain glycol, and a polyether-ester copolymer having a polyether segment obtained from an aromatic dicarboxylic acid and a polyalkylene glycol, and an aromatic dicarboxylic acid. Polyester-ester copolymers having a polyester segment obtained from an acid and a short-chain glycol and a polyester segment obtained from polycaprolactone are preferred.

In the present invention, the thermoplastic resin (A) and the thermoplastic resin composition (B) may be added with, if necessary, an inorganic filler or a stabilizer in addition to the above components. Can be. This inorganic filler is effective not only for cost reduction as a bulking agent but also for improving the appearance (gloss) of the molded product. As the filler added here, for example, calcium carbonate, talc, clay, carbon black,
Examples include magnesium hydroxide, mica, barium sulfate, natural silicic acid, synthetic silicic acid, titanium oxide, magnesium oxide, and zinc oxide.

Examples of the stabilizer include heat stabilizers, ultraviolet absorbers, hindered amine stabilizers, and antioxidants. Further, glass fibers, carbon fibers, nylon fibers, coloring agents, and the like can also be added. In the present invention, the amount of these inorganic fillers, stabilizers and the like is not particularly limited, and can be arbitrarily added for the purpose of improving the heat-sealing force to a resin, mechanical strength, and the like. It is 0 to 50% by weight based on the obtained thermoplastic resin composition (B).

The medical plug according to the present invention comprises a tubular body made of the above-mentioned thermoplastic resin (A) and a thermoplastic resin composition (B).
The elastic plug material can be manufactured by integral molding using. Known means can be applied to the integral molding of the cylinder and the elastic plug material, and there is no particular limitation.

For example, as shown in FIG. 1, the elastic plug material 3 to be fused to the cylindrical body 2 may be injection-molded first, and then the cylindrical body 2 may be outsert-molded to be integrally formed. First, injection molding may be performed, and then the elastic plug material 3 to be fused with the cylindrical body 2 may be inserted and molded.

Apart from this, after the elastic plug material 3 is molded by using a two-color molding machine, the mold is turned over and the cylinder 2 is outsert, and then the cylinder 2 is molded. After that, the mold may be inverted and molded by a method of inserting the elastic plug material 3. Here, two-color molding means that two cylinders are provided, each of which is supplied with two colors or two types of molding materials, and is simultaneously or sequentially supplied to one mold cavity attached while plasticizing and melting. And a two-color (seed) molding.

In order to form the void portions (or non-fused portions) a and b, for example, a paper is attached to the portion of the cylindrical body,
Silicone, mineral oil, paraffin oil, or the like may be applied, or a part of the mold may be inserted with an appropriate article so that the elastic plug does not flow.

As shown in FIG. 1, a gap (or a non-fused portion) between the cylindrical body 2 and the elastic plug material 3 is formed by the presence of a and b.
A contraction portion for the distortion between them is provided, and the hollowing of the central portion seen in the prior art is prevented.

Here, as shown in FIG. 2, the gap (or the non-fused portion) is formed only on the inner side a of the elastic plug material, thereby preventing turning up when piercing a tubular object such as a needle. This is preferable since the needle sticking property is markedly improved.

[0046]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Comparative Example 1 As a thermoplastic resin composition (B) used for an elastic plug, 80 parts by weight of the following component (a), 20 parts by weight of the component (b), and 150 parts by weight of the component (c) were kneaded. At 200 ° C. to obtain pellets.

Component (a) Styrene-isoprene block copolymer [Septon 40
55, manufactured by Kuraray Co., Ltd., styrene content = 30% by weight,
Isoprene content = 70% by weight, weight average molecular weight 26
0000, 1,4-microstructure content 90% by weight, molecular weight distribution 1.3, hydrogenation rate = 90% or more]

Component (b) Polypropylene (block) [MS670, manufactured by Tokuyama Soda Co., Ltd., melt flow rate: 23 g / 10 min (JI
SK6758, 2300 ° C, 2,160 g)]

Component (c) Paraffin oil [PW-90, manufactured by Idemitsu Kosan Co., Ltd.
Weight average molecular weight = 540]

As the thermoplastic resin (A) used for the cylindrical portion, polypropylene [MS64, manufactured by Tokuyama Soda Co., Ltd.]
0], the cylindrical body 2 of the medical stopper shown in FIG. 3 was injection molded. Thereafter, the molded product is put into a predetermined cavity of another mold, and then the elastic plug material 3 is insert-molded by using a pellet of the above-mentioned thermoplastic resin composition (B) as the elastic plug material. The obtained molded article was obtained. It should be noted that a void (or a non-fused portion) between the cylindrical body 2 and the elastic plug material 3 was not formed.

Separately, the two-color molding machine is used to form the cylinder 2
After molding, the mold shown in FIG. 3 could be obtained also by a method of inverting the mold and inserting the elastic plug material 3.

However, both the cylindrical body and the elastic plug formed by the above two methods have a cavity at the center of the elastic plug due to the distortion between them.

Example 1 In the same manner as in Comparative Example 1, a molded article of the medical stopper shown in FIG. 1 was formed. This molded product is provided with voids (or non-fused portions) a and b between the cylindrical body 2 and the elastic plug material 3 by inserting a sleep pin into a mold. In addition, the length of the outer peripheral portion 31 in the penetration direction of the tubular object is about 3.0 mm, and is set to be about 50% shorter than that of the central portion 32.

Example 2 In the same manner as in Comparative Example 1, a medical stopper shown in FIG. 2 was formed. The gap (or the non-fused portion) between the cylindrical body 2 and the elastic plug material 3 was provided only in the portion a inside the plug. As a result, as shown below, turning up of the needle did not occur, and the needle sticking property was greatly improved.

The adhesive strength, needle sticking property, and re-sealing property between the cylindrical body and the elastic plug material of the medical stopper obtained in each of the above examples were measured. The adhesive strength was determined by fixing the obtained molded product on a test table, and then placing the push rod of R5 at the center of the elastic plug material so that the push rod had a tip of R5.
The comparison was performed with f load (including the load of the push rod) applied. The needle piercing property was determined by attaching the obtained molded article to a simulated medical infusion bag (plastic bag) and comparing the ease of piercing when inserting a 4 mm-diameter plastic needle (manufactured by Terumo Corporation). The resealability was measured by attaching the obtained molded article to a simulated medical infusion bag (plastic bag), inserting a plastic needle having a diameter of 4 mm (manufactured by Terumo Corporation) for 1 hour, and then leaking for 10 minutes. Was observed. Table 1 shows the results.

[0057]

Table 1 Comparative Example 1 Example 1 Example 2 Adhesive force 〇 力 Needle piercing property (deformability) 〇 〇 Needle piercing property (resistance) 再 Resealability × 〇 Adhesive force (load of 10 kgf) (Situation) (Situation with a load of 8 kgf) ◎ No drop-off, no deformation ◎ No drop-off, no deformation 落 No drop-off, slightly deformed 〇 No drop-off, no deformation × drop-off, deformed × drop-off, deformed Needle sticking (deformability) ) (Resistance) ◎ None ◎ Smooth piercing ○ Slight deformation ○ Some resistance × Deformation × Resistance Resealability ◎ No liquid splattering, no liquid leakage 〇 There is liquid leakage of seeping out × 1 ~ 2 drops of liquid leakage

[0058]

According to the present invention, there is provided a medical stopper excellent in liquid leakage resistance, needle sticking property, resealing property, cost efficiency, and the like, and a method for manufacturing the same.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an embodiment of the medical stopper of the present invention.

FIG. 2 is a cross-sectional view of another embodiment of the medical stopper of the present invention.

FIG. 3 is a cross-sectional view showing an example of a conventional medical stopper.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Medical stopper 2 Cylindrical body 3 Elastic plug material 31 Outer peripheral part 32 Central part

Claims (4)

[Claims] 1. An elastic plug made of a non-vulcanized thermoplastic elastomer is integrally formed at one end of a cylindrical body mainly composed of a thermoplastic resin, and the elastic plug is formed into a tubular object such as a syringe needle. In the medical plug used to penetrate, the elastic plug material has an outer peripheral portion that is fused to the cylindrical body, and a central portion that penetrates the tubular material, and the elastic plug material in the penetration direction of the tubular material. The medical stopper according to claim 1, wherein a length of the outer peripheral portion is shorter than that of the central portion. 2. The medical stopper according to claim 1, wherein the length of the outer peripheral portion in the penetration direction of the tubular object is shorter by 2 to 98% than that of the central portion. 3. A void portion or a non-fused portion formed because the length of the outer peripheral portion in the penetrating direction of the tubular object is shorter than that of the central portion, is provided on the inner side of the elastic plug material. The medical stopper according to claim 1 or 2, wherein the medical stopper is a medical stopper. 4. A cylindrical body mainly composed of a thermoplastic resin, and an elastic plug made of a non-vulcanized thermoplastic elastomer,
In the method for manufacturing a medical stopper used by penetrating a tubular object such as an injection needle into the elastic stopper member, an outer peripheral portion where the elastic stopper member is fused to the cylinder, and a center penetrating the tubular member And the cylindrical body and the elastic plug material are integrally formed such that the length of the outer peripheral portion in the penetration direction of the tubular object is shorter than that of the central portion. Of manufacturing medical stoppers.