JPH1058623A - Wrapping material for radiation sterilization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure high shape retaining properties and transparency by using a resin layer obtained by substituting part of the ethylene glycol component of polyethylene terephthalate resin with cyclohexane dimenthanol and a polyolefine resin layer as constituents. SOLUTION: This wrapping material for radiation sterilization is composed of a copolymer polyester resin layer 1 obtained by substituting 10-40% of the ethyleneglycol component of polyethylene terephthalate resin with cyclohexane dimenthanol, and a polyolefine resin layer 3 through an adhesive resin layer 2. When the thickness of the copolymer polyester resin layer 1 is a(μm), the thickness of the adhesive resin layer 2 is b(μm) and the thickness of the polyolefine resin layer 3 is c(μm), the formula 30<=a+b+c<=1500 needs to be satisfied. In addition, preferably the formula 50<=a+b+c<=1200 needs to be satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a packaging material for radiation sterilization. Particularly, the present invention relates to a radiation sterilizing packaging material suitable for blister packaging containers for sterilizing medical instruments using radiation such as gamma rays.

[0002]

2. Description of the Related Art Conventionally, medical instruments such as disposable syringe needles and disposable syringes are stored in a packaging container such as a blister package and then sterilized with a gas sterilizing agent such as ethylene oxide. Ethylene oxide requires a long time to evaporate gas after sterilization, and a radiation sterilization method has recently been proposed as a method not using such a sterilization method. In the radiation sterilization method, a medical device is irradiated with radiation after being housed in a packaging container. However, irradiation has an adverse effect such as deterioration or coloring of the packaging container. For example,
As the blister packaging container as described above, a rigid vinyl chloride resin is used from the viewpoint of good shape retention and excellent transparency. However, when radiation sterilizing a medical device stored in such a blister packaging container,
There is a drawback that the rigid dome resin, which is a dome material, cannot be used for radiation sterilization due to coloring.

At present, as a dome material for blister packaging containers for radiation sterilization of medical instruments as described above, engineering plastics such as polycarbonate and the like are available, all of which are expensive. The use of high-impact polystyrene has also been proposed, but has the disadvantage of low transparency.In addition, ordinary polystyrene cannot be used as a blister packaging material unless biaxial stretching is used. In addition, the biaxially stretched film has problems such as shrinkage in the process, and has problems such as being difficult to use and lacking in flexibility to take out the product.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made as a result of intensive studies to solve the conventional problems described above, and its object is to provide an inexpensive, excellent shape retention and transparency. To provide a novel packaging material for radiation sterilization which is excellent in Another object of the present invention is to provide a material suitable as a dome material of a packaging material for radiation sterilization.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a thermoplastic film of a packaging material which is used after being sterilized by radiation, in which 10 to 40% of an ethylene glycol component of a polyethylene terephthalate resin is substituted with cyclohexanedimethanol. A radiation-sterilized packaging material comprising a resin layer and a polyolefin-based resin layer with an adhesive resin layer interposed therebetween. More preferably, the thickness of the copolymerized polyester resin layer a (μm) and the thickness of the adhesive resin layer b ( μ
m) and the thickness c (μm) of the polyolefin-based resin layer are 30 ≦ a + b + c ≦ 1500 and 0.5 ≦ a /
The formula (a + b + c) ≦ 0.98 is satisfied, the polyolefin resin is a polyethylene resin, and the radiation sterilizing packaging material is a radiation sterilizing packaging material that is a dome material of a blister packaging container.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The copolymerized polyester resin of the present invention is a polyethylene terephthalate resin obtained by substituting 10 to 40% of an ethylene glycol component with cyclohexane dimethanol. Is less than 10%, the set temperature range during film formation or blister molding is narrow due to crystallinity,
It is cloudy and cannot be used. Conversely, when the substitution amount of the ethylene glycol component exceeds 40%, the tensile strength and the flexural modulus decrease, and the stiffness of the sheet becomes weak, and the sheet cannot be used. Therefore, the substitution amount of the ethylene glycol component is desirably 10 to 40%. More preferably, it is 20 to 35%.

The adhesive resin of the present invention can effectively bond the copolymerized polyester resin layer and the polyolefin-based resin layer, and basically does not impair transparency or moldability. However, there is no particular limitation here. For example, a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof is used. Here, as the polyolefin resin, polyethylene, polypropylene, polybutene-1, poly-4-
Examples include olefin homopolymers such as methylpentene-1 and copolymers of α-olefins having 2 to 20 carbon atoms or unsaturated esters copolymerizable with α-olefins such as ethylene, propylene and butene-1. As the α-olefin used in this case, propylene, butene-1,
Penten-1, hexene-1, 4-methyl-pentene-
1, octene-1, and the like, and examples of the unsaturated ester include vinyl acetate, vinyl butyrate, vinyl propionate, methyl acrylate, propyl acrylate, methyl methacrylate, and ethyl methacrylate.

The unsaturated carboxylic acids used for the modification include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, sorbic acid, mesaconic acid, angelic acid and the like. Derivatives include acid anhydrides, esters, amides, imides, metal salts and the like, such as maleic anhydride, itaconic anhydride,
Examples thereof include methyl acrylate, ethyl acrylate, methyl methacrylate, monoethyl maleate, acrylamide, and sodium acrylate.

There are various methods for modifying a polyolefin resin with an unsaturated carboxylic acid or a derivative thereof, and there is no particular limitation. For example, a maleic anhydride or the like may be added in the presence or absence of a solvent by adding a radical initiator. Then, the reaction may be performed by heating. The content of the unsaturated carboxylic acid or its derivative in the modified polyolefin resin is usually 0.001 to 20% by weight, and it can be used in the form of a mixture with an unmodified polyolefin resin.

The polyolefin resin of the present invention includes:
Any of low density (high pressure method low density polyethylene, linear low density polyethylene, etc.), medium density and high density polyethylene can be used.
Butene-1, pentene-1, 3-methylbutene-1, 4
-Homopolymers such as methylpentene-1 and octene-1, or crystalline, low-crystalline to amorphous random or block copolymers thereof with α-olefins or vinyl acetate, or mixtures thereof are used. Although it is possible, a polyethylene resin is preferable. In the copolymer, the proportion of the copolymerized monomer is preferably 10 mol% or less. In the case of polyethylene resin, the melt index (MI) is in the range of 0.02 to 50,
Those having a density in the range of 0.850 to 0.980 g / cm ³ are preferable.

FIG. 1 is a cross-sectional view of the radiation sterilizing packaging material according to the present invention. If the total thickness is less than 30 μm, the blister packaging container cannot be used because of poor strength such as pinhole resistance. Conversely, if it exceeds 1500 μm, it is difficult to heat the entire film, and blister molding is difficult. Therefore, the copolymerized polyester resin layer 1
Is a (μm), and the thickness of the adhesive resin layer 2 is b (μm).
m), the thickness of the polyolefin-based resin layer 3 is c (μm)
Then, it is necessary to satisfy the expression of 30 ≦ a + b + c ≦ 1500, and further, 50 ≦ a + b + c ≦ 120
It is more preferable to satisfy the expression 0. When the thickness of the copolyester resin layer 1 is less than half the total thickness of the radiation sterilizing packaging material, the blister moldability is poor, and the blister packaging container is not only stiff but also has poor transparency and cannot be used. . Conversely, when the thickness of the copolyester resin layer 1 exceeds 98% of the total thickness of the radiation sterilizing packaging material, film formation becomes extremely difficult. Therefore,
It is necessary to satisfy the expression 0.5 ≦ a / (a + b + c) ≦ 0.98, and further, 0.6 ≦ a / (a + b +
c) It is more preferable to satisfy the expression of ≦ 0.95.

As a method for producing the radiation sterilizing packaging material of the present invention, in addition to a usual co-extrusion molding method, a method commonly used for lamination processing, for example, extrusion lamination, hot melt lamination, dry lamination,
A method such as wet lamination can be used.
When the radiation-sterilized packaging material thus obtained is used as the dome of a blister packaging container, the front and back of the sheet are not particularly limited, and the adhesiveness to the lid material used and the suitability of the blister molding machine. Can be determined each time.

[0013]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto. EAST is used as the copolymerized polyester resin.
MAN CHEMICAL PRODUCT INC.
"PETG 6763" manufactured by Mitsui Petrochemical Co., Ltd. as an adhesive layer, and "Sumikacene L-" manufactured by Sumitomo Chemical Co., Ltd. as a polyolefin resin.
211 (polyethylene resin) "and a film was formed by a co-extrusion method. That is, the three layers were simultaneously extruded using the feed block method and the T-die method, cooled, and wound. Table 1 shows the configuration of each sheet. Comparative Example 1 has a thickness of 30 manufactured by the calendaring method.
It is a hard PVC sheet of 0 μm. The obtained radiation-sterilized packaging material was evaluated in three steps for the following three items. (○: No problem △: Some troubles occur, but use is possible ×: Problems occur, use is impossible) ・ Film formation: Whether film formation can be performed without problems in pinhole and thickness accuracy during film formation by co-extrusion. -Blister moldability: Is it possible to mold without blistering or tearing as in the mold when blister molding is performed?・ Radiation sterilization: Whether there is any discoloration due to yellowing or the like and significant deterioration in strength after irradiation of 25 kGy with γ-rays as radiation.

Table 1 shows the evaluation results of Examples 1 to 6 and Comparative Examples 1 to 5.

[Table 1]

[0015]

As described above, the packaging material for radiation sterilization according to the present invention has excellent film-forming properties and blister moldability.
Irradiation sterilization by γ-rays or the like is suitable as a material for packaging containers for radiation sterilization, especially for blister packaging containers for medical instruments, since there is little physical property deterioration such as discoloration.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of a packaging material for radiation sterilization according to the present invention.

[Explanation of symbols]

 1: Copolyester resin layer 2: Adhesive resin layer 3: Polyolefin resin layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B65D 65/40 B65D 65/40 D

Claims (4)

[Claims] 1. A thermoplastic film of a packaging material which is used after being sterilized by radiation, wherein a copolyester resin layer and an adhesive resin layer obtained by replacing 10 to 40% of an ethylene glycol component of a polyethylene terephthalate resin with cyclohexanedimethanol. A radiation sterilizing packaging material comprising a polyolefin-based resin layer through the intermediate layer. 2. The thickness a of the copolymerized polyester resin layer
(Μm), the thickness b (μm) of the adhesive resin layer, and the thickness c (μm) of the polyolefin-based resin layer, 30 ≦ a + b +
c ≦ 1500 and 0.5 ≦ a / (a + b + c) ≦ 0.
2. The packaging material for radiation sterilization according to claim 1, wherein the packaging material satisfies the equation (98). 3. The packaging material for radiation sterilization according to claim 1, wherein the polyolefin resin is a polyethylene resin. 4. The radiation-sterilized packaging material is a dome material of a blister packaging container.
4. The packaging material for radiation sterilization according to 2 or 3.