JP2516996B2 - Vinyl chloride resin composition for infusion containers - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a vinyl chloride-based resin composition for an infusion container.

Technical background of the invention and its problems Conventionally, medical equipment such as blood packs for transporting and storing blood, blood circuit tubes for artificial dialysis, etc. have been made of vinyl chloride polymer and dioctyl phthalate which is a liquid plasticizer. It was molded from a so-called soft vinyl chloride resin composition which was plasticized by adding (hereinafter referred to as DOP).

However, from the molded product of such a soft vinyl chloride resin composition, DOP used as a plasticizer may be eluted into the contents such as blood, and may be absorbed and accumulated in the body.

As one method for solving such a problem, instead of DOP as a liquid plasticizer, an ethylene / carbon monoxide / vinyl acetate copolymer, which is a polymer plasticizer that is unlikely to elute in blood, is used. Has been proposed.

However, a vinyl chloride resin composition prepared by blending a vinyl chloride polymer with ethylene / carbon monoxide / vinyl acetate copolymer as a plasticizer is excellent in transparency and flexibility, and is suitable as a resin composition for medical equipment. Although it satisfies the required basic physical properties, heating during molding and processing causes the plasticizer ethylene / carbon monoxide / vinyl acetate copolymer to partially decompose and release acetic acid. It dissolves in the product, and the Δ value of the solute test prescribed by the Japanese Pharmacopoeia and the notification of the Ministry of Health and Welfare
There is a problem that it gives an unfavorable result to pH and hemolysis. Therefore, for example, JP-A-56-41240 discloses a vinyl chloride resin composition using an ethylene / carbon monoxide / vinyl acetate copolymer as a plasticizer in order to eliminate the adverse effect of the elimination of acetic acid. A method of adding magnesium oxide or calcium oxide as a scavenger of acetic acid has been proposed. However, also in this composition, when the amount of acetic acid generated by thermal decomposition from the plasticizer is small, acetic acid can be captured by the scavenger, but the compounding amount of the plasticizer increases or molding is performed. When the heat history during processing is long and the amount of acetic acid released is large, it is necessary to increase the amount of the scavenger, resulting in a decrease in transparency of the vinyl chloride-based resin composition, and a residual ignition residue. There was a problem that it increased and exceeded the regulation value of the Japanese Pharmacopoeia.

OBJECT OF THE INVENTION The present invention solves the problems associated with the prior art as described above, and the plasticizer itself is eluted, or the plasticizer is decomposed and its components are detached and eluted into the contents such as blood. It is an object of the present invention to provide a new vinyl chloride-based infusion container resin composition that does not exist.

SUMMARY OF THE INVENTION The resin composition for a vinyl chloride-based infusion container according to the present invention,
It is characterized in that an ethylene / carbon monoxide / alkyl (meth) acrylate copolymer component is used as a plasticizer for the vinyl chloride polymer.

The resin composition for a vinyl chloride-based infusion container according to the present invention,
As it contains ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer as a plasticizer, the plasticizer does not migrate to the contents such as blood during use, and acetic acid is desorbed to change the pH. Does not occur.

DETAILED DESCRIPTION OF THE INVENTION The composition for a vinyl chloride-based infusion container according to the present invention will be specifically described below.

The resin composition for a vinyl chloride-based infusion container according to the present invention,
The plasticizer of the vinyl chloride polymer is characterized by containing ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer.

In the vinyl chloride-based infusion container resin composition according to the present invention, the vinyl chloride-based resin used as a base is not only a vinyl chloride homopolymer, but also vinyl chloride and other monomers such as ethylene and propylene.
-Olefins, vinyl esters such as vinyl acetate,
Unsaturated carboxylic acid esters such as acrylic acid esters, vinyl ethers such as alkyl vinyl ethers,
Vinyl halides such as vinyl bromide and vinyl fluoride,
Other than the above, a copolymer with a vinyl compound such as styrene, acrylonitrile, or vinylidene chloride or a vinylidene compound is used. In this copolymer, other monomers than vinyl chloride may be present in amounts up to 20 mol%. In addition to these, ethylene-vinyl acetate copolymer, a copolymer in which a thermoplastic urethane polymer is used as a trunk polymer, and vinyl chloride is graft-polymerized to this is used.

Such vinyl chloride resin has a number average degree of polymerization of 300
It is desirable to have a degree of polymerization of ˜5,000, preferably 500 to 2,000.

The ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer contained in the vinyl chloride resin as a plasticizer as described above includes ethylene, carbon monoxide and (meth)
Although it is an acrylic acid alkyl ester copolymer, the alkyl group in this (meth) acrylic acid alkyl ester is linear or branched and has 1 to 10 carbon atoms.
18, specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a t-butyl group, an isobutyl group, a hexyl group, an octyl group, and the like, Of these, those having 2 to 6 carbon atoms are preferable.

In this ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer, ethylene is 40 to 80% by weight,
Preferably in an amount of 60-70% by weight, carbon monoxide in an amount of 5-30% by weight, preferably in an amount of 5-15% by weight, (meth) acrylic acid alkyl ester is in an amount of 15-60% by weight, preferably 20-
It is preferably contained in an amount of 35% by weight, and it is possible to further copolymerize other monomers, if necessary.

In order to produce such an ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer, each of the monomers ethylene, carbon monoxide, and (meth) acrylic acid alkyl ester is used as a catalyst. It is supplied in a predetermined ratio with t-butyl peroxyisobutyrate or azodiisobutyronitrile into a high-speed stirring reaction vessel and mixed, and at high temperature (160 to 230 ° C) and high pressure (24000 to 27000ps).
The monomer may be copolymerized by stirring at high speed in i).

The ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer has an MFR of 1 to 500 g / 10 minutes, preferably 5 to 100 g / 10 minutes.

The resin composition for a vinyl chloride-based infusion container according to the present invention,
In addition to the above vinyl chloride resins and ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymers, non-toxic additives used for medical device applications such as calcium stearate, zinc stearate, and epoxidized It may also contain soybean oil, di-n-octyltin compound, tris (nonylphenyl) phosphite and the like.

The resin composition for a vinyl chloride-based infusion container according to the present invention,
The vinyl chloride resin as described above, an ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer as a plasticizer, and additives such as a stabilizer and a lubricant, if necessary, may be used in a roll or a Banbury. Using a batch-type kneader such as a mixer or a continuous kneader such as a twin-screw extruder,
It is obtained by melt mixing (melt blending).

In the present invention, a vinyl chloride resin composition generally obtained by melt-mixing the above vinyl chloride resin and ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer as a plasticizer In some cases, vinyl chloride alone or in the presence of ethylene / carbon monoxide / alkyl (meth) acrylate copolymer is radically polymerized with the above-mentioned monomer capable of copolymerization with vinyl chloride. A vinyl chloride-based graft polymer composition of a so-called ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer obtained as described above can also be used.
The production of such a vinyl chloride graft polymer can be carried out according to the method described in JP-B-39-27876 or JP-A-56-139518.

Further, in some cases, the composition of the present invention comprises a vinyl chloride graft polymer of the above-mentioned ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer and ethylene / carbon monoxide / (as a plasticizer. It may be a blend of a (meth) acrylic acid alkyl ester copolymer, or may be a mixture of the vinyl chloride-based graft polymer and the vinyl chloride-based polymer.

Whether the ethylene / carbon monoxide / (meth) acrylic acid ester copolymer is simply blended or used as a base polymer of the graft polymer, the ethylene / monomer in the vinyl chloride resin composition according to the present invention Carbon oxide
The content ratio of the (meth) acrylic acid alkyl ester copolymer is such that the vinyl chloride resin component and ethylene / carbon monoxide /
The amount is 25 to 67% by weight, preferably 33 to 60% by weight, based on the total weight of the (meth) acrylic acid alkyl ester copolymer component. When the blending ratio of these copolymers is less than 25% by weight, transparency and flexibility are poor, which is not preferable. On the other hand, when it exceeds 67% by weight, the surface of the obtained infusion container is not sticky. In the case of a sheet product, blocking is likely to occur, which is not preferable.

The vinyl chloride resin composition according to the present invention is used for an infusion container as described above, but in addition, a blood transfusion set,
Infusion set, catheter, blood circuit set for artificial kidney,
It can also be used as a blood bag in a blood collection set, a blood collection tool, a blood circuit tube, or surgical gloves.

Effects of the Invention The resin composition for a vinyl chloride-based infusion container according to the present invention,
Since it contains ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer as a plasticizer, the plasticizer does not migrate to the contents such as blood during use,
Moreover, acetic acid is not desorbed to cause pH change.

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

Example 1 100 parts by weight of a vinyl chloride resin (vinyl chloride 3000M, manufactured by Mitsui Toatsu Chemicals, Inc., number average degree of polymerization: 1100) was added to ethylene / carbon monoxide / n-butyl acrylate copolymer (acrylic acid n
-Butyl content 30% by weight, carbon monoxide content 10% by weight, MFR1
100 parts by weight of 0 dg / min), 0.7 parts of calcium zinc stabilizer and 5 parts of epoxidized soybean oil were well kneaded at 160 ° C. with a two-roll mill to obtain a vinyl chloride resin composition. The obtained vinyl chloride resin composition was hot-pressed at 160 ° C. to obtain a press sheet having a thickness of 1 mm.

The following test items were evaluated using the obtained press sheet.

 The evaluation results are shown in Table 1.

(1) Tensile properties: A JIS No. 3 dumbbell test piece was prepared according to JIS K-6723, and a tensile test was performed at 23 ° C using an autograph at a tensile speed of 200 mm / min to obtain a 100% modulus,
The tensile strength at break and elongation at break were measured. Especially 100%
The flexibility of the sheet was evaluated from the modulus value.

(2) Transparency: Shimadzu UV spectrometer
The transmittance at 550 nm was measured using UV-265FW.

(3) pH change: In accordance with the dissolution test method of the Japanese Pharmacopoeia infusion plastic container test method, a strip of a press sheet is immersed in distilled water, and the dissolution test is performed at 121 ° C for 1 hour using the high-pressure sterilizer described above. Then, the difference in pH between the obtained eluate and blank test solution was examined.

(4) Residue on ignition: According to the Japanese Pharmacopoeia test method for residue on infusion plastic containers, strips of press sheet
The ignition residue was measured using 1 g.

Comparative Example 1 In Example 1, instead of the ethylene / carbon monoxide / n-butyl acrylate copolymer, an ethylene / carbon monoxide / vinyl acetate copolymer (carbon monoxide content 10% by weight, vinyl acetate content 24 The test was carried out under the same conditions as in Example 1 except that (wt%, MFR 35 dg / min) was used.

 Table 1 shows the results.

Comparative Example 2 A test was performed in the same manner as in Comparative Example 1 except that 1 part by weight of fine powder of reagent-grade magnesium oxide as an acetic acid scavenger was added in Comparative Example 1.

 Table 1 shows the results.

The press sheet of Example 1 is flexible and transparent and has a ΔpH,
The ignition residue is below the regulation value of the Japanese Pharmacopoeia and satisfies the suitability for an infusion container, whereas the press sheet of Comparative Example 1 has a ΔpH of Japanese Pharmacopoeia due to desorbed acetic acid. It was over the regulation value. In Comparative Example 2, the transparency was lowered by magnesium oxide added as an acetic acid scavenger, and the ignition residue exceeded the regulation value of the Japanese Pharmacopoeia.

Example 2 In Example 1, instead of the vinyl chloride resin, a vinyl chloride-ethylene copolymer resin (Luron E-10 manufactured by Toyo Soda Co., Ltd.) was used.
50, ethylene content 2% by weight, number average degree of polymerization 1050) 100 parts by weight, press sheet as in Example 1 except that 50 parts by weight of ethylene / carbon monoxide / n-butyl acrylate copolymer was used. Was manufactured and tested on it.

The obtained results are shown in Table 2, but the transparency of the sheet was slightly lowered.

Example 3 Example 3 was repeated except that ethylene / carbon monoxide / n-butyl acrylate copolymer was replaced with 50 parts by weight of ethylene / carbon monoxide / n-butyl acrylate copolymer. The test was conducted in the same manner as in Example 1.

The obtained results are shown in Table 2, and the surface of the sheet was somewhat sticky.

Claims (1)

(57) [Claims] 1. An ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer [wherein the alkyl group in the (meth) acrylic acid alkyl ester is linear or branched and has 1 to 18 carbon atoms. A) A vinyl chloride-based resin composition for an infusion container, which comprises 25 to 67% by weight and a vinyl chloride-based resin of 75 to 33% by weight.