JPS5951836B2 - medical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a medical device made of a novel soft thermoplastic resin.

Currently, medical equipment such as blood transfusion sets, infusion sets, artificial kidney circuits, rectal catheters, and gastric tubes are made of soft polyvinyl chloride containing dioctyl phthalate (hereinafter abbreviated as DOP) as a plasticizer. There is.

These medical devices are flexible and transparent in their use.
It is required that it has heat resistance to the extent that it can withstand high-pressure steam sterilization, and that it can be easily processed by means such as thermal bonding.

The soft polyvinyl chloride blended with DOP has been used as a material that satisfies the above conditions, but it has the drawback that DOP is eluted and hardened.

Also, is DOP used in various countries as a harmless substance? However, it has recently been pointed out that DOP is eluted by blood from blood bags, etc., and the danger of eluted DOP being circulated in the human body is being questioned.

The inventors of the present invention have developed a material that satisfies conditions such as flexibility, transparency, heat resistance to withstand high-pressure steam sterilization, and thermal adhesiveness, and has no concerns associated with DOP, and has created a medical device using this material. As a result of intensive studies aimed at this purpose, the present invention was completed.

That is, the present invention is soluble in vinyl chloride monomer, has a softening point of 20 to 100°C, and has a softening point of 100% of the monomer or monomer mixture described below.
10 to 200 parts by weight of thermoplastic polyurethane elastomer (hereinafter abbreviated as MVC soluble TPU)
Vinyl chloride monomer (hereinafter abbreviated as MVC) alone or vinyl chloride monomer and a monomer that can be copolymerized with it and provides a homopolymer with a glass transition temperature lower than 30°C in the coexistence of This medical device is made of a soft thermoplastic resin obtained by polymerizing a monomer mixture (hereinafter collectively referred to as MVC monomer) in an aqueous medium.

The soft thermoplastic resin in the present invention is MVC soluble TP
It is produced by polymerizing MVC monomers with U dissolved in MVC.

Although the nature of this reaction is not clear, MVC-soluble TPU
and a certain type of chemical bond (i.e., a reaction called graft copolymerization) with the MVC monomer.

) is estimated to occur.

i.e. a significant improvement in the resulting polymer according to the present invention compared to a polymer blend of TPU and PVC at the time of compounding;
That is, it is inferred from the fact that it is excellent in terms of processability, transparency, flexibility, etc.

The MVC-soluble TPU in the present invention is one that is substantially soluble in the MVC monomer under the polymerization conditions of the present invention, and has a softening point of 100° to 20°C, preferably 60° to 20°C. It is at 30℃.

If the softening point exceeds 100°C, it will be difficult to dissolve in MVC, and if the softening point is lower than 20°C, the resulting polymer will have poor tensile strength and heat resistance.

Moreover, the MVC soluble TPU is preferably a non-yellowing type that uses aliphatic diisocyanate as a raw material.

Non-yellowing types have good UV stability, whereas non-yellowing types tend to produce colored polymers after polymerization.

One suitable type of MVC soluble TPU that is effective in the present invention is 1. There are trade names such as Bandex T-5265 and Pandex T-525 manufactured by Dainippon Ink and Chemicals.

In the present invention, the MVC soluble TPU is MVC soluble at the time of preparation.
Or 10 to 20 parts by weight based on 100 parts by weight of MVC monomer.
Polymerization is initiated at 0 parts by weight, preferably from 20 to 150 parts by weight.

For 100 parts by weight of MVC or MVC monomer, M
If the amount is less than 2 parts by weight of VC-soluble TPUIO, the resulting polymer will not have satisfactory softness, while if it exceeds 200 parts by weight, the polymerization rate will be undesirably slow.

In the present invention, the MVC-soluble TPU content in the produced polymer is preferably 10 to 80% by weight, more preferably 17% by weight.
~65% by weight is good.

If it is less than 10% by weight, it is difficult to obtain satisfactory softness.

On the other hand, if it exceeds 80% by weight, the heat resistance tends to deteriorate and the cost increases, which is not economically preferable.

In the present invention, as mentioned above, a part of MVC is
By using a monomer which can be replaced by a monomer copolymerizable with VC and which gives a homopolymer with a glass transition temperature lower than 30° C., it is possible to It is possible to maintain various physical properties peculiar to the soft thermoplastic resin obtained by polymerizing MVC, especially processability and flexibility suitable for use as medical devices.

On the other hand, if part of the MVC is replaced by a monomer that provides a homopolymer with a glass transition temperature of 30°C or higher, the resulting resin will require higher molding temperatures during processing and molding. As a result, the resin undergoes thermal deterioration during processing and molding, and the resin does not meet the standards and is not suitable for medical devices, so the use of such monomers should be avoided. be.

In the present invention, monomers that can be copolymerized with MVC and whose homopolymer has a glass transition temperature lower than 30°C include olefins such as ethylene and propylene, vinylidene halides such as vinylidene chloride, and vinyl acetate. vinyl esters such as, vinyl ethers such as n-butyl vinyl ether, butyl acrylate, acrylic acid-2
Examples include acrylic esters such as -ethylhexyl, methacrylic esters such as 2-ethylhexyl methacrylate, and the like.

The amount used is preferably 50% in the MVC monomer.
It is not more than 30% by weight, more preferably not more than 30% by weight.

This is because if the amount exceeds 50% by weight, the processability, heat resistance, transparency, etc. of the resulting polymer will deteriorate.

The suspending agent used in the present invention may be any known suspending agent.

For example, partially saponified polyvinyl alcohol, methylcellulose, ethylcellulose, hydroxymethylcellulose, polyacrylic acid, vinyl ether-maleic anhydride copolymer, gelatin, etc. are used, and these may be used alone or in combination.

Further, the amount of these used is about 0.01 to 2% by weight based on the aqueous medium.

The oil-soluble polymerization initiator used in the present invention may be any known polymerization initiator.

For example, azo compounds such as azobisisobutylvaleronitrile, lauryl pernegiside 1. Examples include organic peroxides such as di-2-ethylhexyl oxydihydrobonate and t-butyl peroxypivalate.

The amount used is 0.01 per MVC monomer at the time of preparation.
It is about 2% by weight.

□ In the present invention, the charging ratio of aqueous medium/(MVC soluble TPU to MVC monomer) is preferably 1/1 to 3/1.

This is because if the ratio is less than 171, polymerization tends to become unstable, and if the ratio exceeds 371, it is not economically advantageous.

The polymerization temperature is preferably 30° to 70°C, preferably 40° to 60°C.

This is not industrially advantageous since the polymerization rate tends to slow down below 30°C.

Moreover, if the temperature exceeds 70°C, the heat resistance of the resulting polymer tends to deteriorate, which is not preferable.

In the present invention, known chain transfer agents such as trichlorethylene and mercaptoethanol may be used.

As the polymerization method, a suspension polymerization method is usually employed, but a conventional emulsion polymerization method can also be employed.

In the present invention, a stabilizer can be added to aid the heat aging resistance of the soft thermoplastic resin.

However, toxic stabilizers such as lead or cadmium stabilizers must be avoided.

Stabilizers that can be added are calcium stearate and zinc stearate.

In addition, epoxidized soybean oil can be added in small amounts.

The novel soft thermoplastic resin used in the medical device of the present invention is
This soft thermoplastic resin is flexible even without plasticization, and has excellent processability, transparency, heat resistance, and thermal adhesion.
They are molded and processed into medical devices such as catheters, blood transfusion sets, and infusion cellars 1 to 1, which have properties that cause no problems even when they come into direct contact with the human body or with liquids such as infusions that are injected into the human body, and are suitable for practical use. Above all, it is extremely useful.

Next, the present invention will be explained in more detail with reference to Examples.

All parts in the examples are parts by weight. Example 1 MVC on stainless steel OI-crepe with internal volume 101
30 parts of soluble TPU (Pandex T-5265 manufactured by Dainippon Ink & Chemicals), 200 parts of pure water, partially saponified polyvinyl alcohol (Gosenol KH- manufactured by Nippon Gosei)
17) Charge 0.8 parts of di-2-ethylhexyl peroxydicarbonate and 0.05 parts of di-2-ethylhexyl peroxydicarbonate, and replace the air inside with N2.
After that, I added 70 copies of MVC.

After carrying out a suspension polymerization reaction at 58° C. for 15 hours, unreacted monomers were removed and this was dehydrated and dried to obtain 90 parts of a powdery polymer.

0.5 parts of calcium stearate and 0.1 parts of zinc stearate were added to 100 parts of the obtained polymer, and PV
After pelletizing at 140° to 160°C using a C extruder, pelletizing at 150 to 180°C using a PVC extruder.
It was processed into a sheet at ℃.

It was also found that this sheet 1~ was transparent and flexible and could be thermally bonded using a high frequency welding machine, and an infusion bag was made using the welding machine.

It was also confirmed that the infusion bag thus obtained could withstand high-pressure steam sterilization.

In addition, all the test items for polyvinyl chloride containers in the 10th revised General Test Methods 42 of the Japanese Pharmacopoeia Law, ``Test Method for Plastic Containers for Infusions,'' were conducted, and all items passed the standards.

Particularly important items such as fine particles, eluate test (zinc, ultraviolet absorption spectrum), acute toxicity test, intradermal reaction test 1@, pyrogenic substance test, and hemolytic test met the standards and there were no problems.

Also, in this example, no DOP is used,
There are no problems associated with this.

Example 2 3 parts of the amount of MVC used (70 parts) was replaced with isobutyl vinyl ether 3, which is a monomer copolymerizable with MVC and whose homopolymer has a glass transition temperature lower than 30°C.
Suspension polymerization was carried out in the same manner as in Example 1 except that 90 parts of a powdery polymer was obtained.

0.5 parts of calcium stearate and 0.1 parts of zinc stearate were mixed per 100 parts of the obtained polymer, and PVC
The pellets were pelletized at 120-140°C using a PVC extruder, and then processed into a sheet at 130-150°C using a PVC extruder.

As a result, a flexible and transparent sheet similar to Example 1 was obtained without any decomposition of the resin.

An infusion bag was manufactured using the sheet in the same manner as in Example 1.

The infusion bag complies with the Japanese Pharmacopoeia Act No. 10 described in Example 1.
Revised General Test Method 42 “Test Method for Plastic Containers for Infusion”
All test criteria for polyvinyl chloride containers were satisfied.

Claims (1)

[Claims] 1 Soluble in vinyl chloride monomer and has a softening point of 20 to 1
It is possible to copolymerize vinyl chloride monomer alone or with vinyl chloride monomer and this in the presence of 10 to 200 parts by weight of a thermoplastic polyurethane elastomer per 100 parts by weight of the monomer or monomer mixture described below at 00°C. Glass transition temperature is 30℃
A medical device comprising a soft thermoplastic resin obtained by polymerizing a monomer mixture with a monomer that gives a homopolymer with a lower homopolymer content in an aqueous medium.