JP2001233374A - Polyester film for medicine wrapping paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester film for a medicine wrapping paper preventing the adhesion of medicines and foreign matters, provided with the visual recognition properties for a content, superior bonding properties to various kinds of inks and superior unsealing properties. SOLUTION: The polyester film for the medicine wrapping paper is characterized by being provided with the surface specific resistance of 5×1012 Ω/(square) or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester film for packaging chemicals, which can prevent adhesion of chemicals and foreign substances, can improve the visibility of contents, and has excellent adhesion to various printing inks.

[0002]

2. Description of the Related Art Biaxially oriented polyester films represented by polyethylene terephthalate have excellent mechanical properties, electrical properties, chemical resistance and dimensional stability.
It is used as a base material in many fields such as information recording materials, capacitors, packaging, plate making, discharging, and photographic films.

In recent years, these polyester films have been used as various packaging films by taking advantage of the excellent properties of the films. In addition to the growing awareness of the importance of environmental issues, the fact that polyester films, in particular, can suppress environmental pollution during their disposal. From now on, its use range is going to expand further.

[0004] The polyester film for packaging is widely used, and is required in various industrial fields including foods, various electric / electronic parts, machines, equipment, building materials, chemicals, and the like.

In particular, in the case of chemical packaging, the quality of the contents greatly affects the human body, and therefore, high-level characteristics are required for various functions required for packaging materials.

Heretofore, especially for medicine packaging, a transparent plastic film such as cellophane has been used as a main component, and a composite material formed by bonding with various plastic films has been used so that the quality of the medicine can be visually recognized from the outside of the packaging material. However, if foreign matter adheres to the surface of the packaging material, the drug is taken out into another container,
Alternatively, when put into the mouth, the foreign matter may fall into the container or into the mouth, causing a problem in hygiene. Alternatively, there is a problem in that the medicine as the content adheres to the surface of the packaging material when the medicine is taken out, adheres to the human body, clothes or the surroundings, and contaminates.

[0007] In addition, cellophane-based packaging papers have coloring characteristic of cellophane, and when the contents are viewed from the outer surface of the packaging material, the color tone of the contents changes, and it is difficult to confirm the contents. There is a problem that abnormalities such as discoloration of the medicine or the like cannot be detected.

[0008] In the case of chemical packaging, in order to maintain the quality of the contents at a high level, for example, it is necessary to have easy-openability so that the packaged medicine can be easily taken out with bare hands while maintaining, for example, the breaking resistance of the packaging material. However, when a conventional polyester film is bonded to another film, the film has high strength, so that there is a problem that tearing by hand is difficult and the film cannot be easily taken out.

In this regard, there has been proposed a method of improving the tear property of a polyester film by, for example, blending a polyester copolymer or an olefin into the polyester film in order to impart easy tear property. For these easily tearable films, the transparency of the film is significantly reduced due to these added components,
Problems such as deterioration of the visibility of the contents occur.

Further, the name of the dispenser, the name of the patient, the date of manufacture, the method of administration, and the like may be described on the surface of the medicine packaging paper. Particularly, the outermost layer of the medicine packaging paper is required to have adhesiveness to various printing inks. ing.

[0011]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to prevent the adhesion of chemicals and foreign substances, improve the visibility of the contents, and apply various inks. An object of the present invention is to provide a medicine package-use film having excellent adhesiveness and excellent openability.

[0012]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above problems, and as a result, have found that a film having a specific structure can easily solve the above problems. Reached.

[0013] That is, the gist of the present invention resides in a polyester film for medicine packaging paper, which has a surface specific resistance of 5 × 10 ¹² Ω / □ or less. Hereinafter, the present invention will be described in detail.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester referred to in the present invention is
A polymer containing an ester group obtained by polycondensation from a dicarboxylic acid and a diol, or from a hydroxycarboxylic acid and an acid. Examples of dicarboxylic acids include terephthalic acid, isophthalic acid, adipic acid, azelaic acid, sebacic acid, 2,6-naphthalenedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid, and diols such as ethylene glycol and 1,4-butane Examples of diol, diethylene glycol, triethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, polyethylene glycol and the like, and examples of hydroxycarboxylic acid include p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid. be able to.

Representative examples of such polymers include polyethylene terephthalate and polyethylene-2,6-naphthalate. These polymers may be homopolymers or copolymers of the third component.

As the film of the present invention, a biaxially stretched film is preferably used from the viewpoint of excellent strength and dimensional stability, but an unstretched or at least one stretched polyester film can also be used.

The film of the present invention needs to have a static protection function in order to prevent a medicine, external dust and foreign matter from adhering to the packaging paper. That is, the surface resistivity of the polyester film of the present invention is 5 × 10 ¹² Ω / □ or less, preferably 1 × 10 ¹² Ω / □ or less, more preferably 5 × 1 Ω / □ or less.
0 ¹¹ Ω / □ or less. Surface resistivity is 5 × 10 ¹² Ω /
If it is higher than □, surrounding dust and chemicals adhere, which is not preferable.

As a method of imparting the antistatic effect, a method of kneading and mixing the antistatic agent into the film, or a method of applying the antistatic agent to the film surface is used.

The antistatic agent is not particularly limited as long as it reduces the surface resistivity.

When the antistatic agent is kneaded into the polyester film as the base material, the surface resistivity of the outermost layer is 5 × 10 ¹² Ω.
/ □ or less, and the polyester film may be a single-layer polyester film or a laminated polyester film composed of at least two layers.

When the medicine packaging paper is opened with a bare hand and opened to take out the medicine, if the tearing resistance is high, the force at the beginning of the tearing is increased, and in some cases, the bag is opened at once and the contents are scattered or the linearity at the time of tearing is obtained. However, problems such as scattering of a part of the contents occur. Alternatively, operations such as fine adjustment of the opening area to adjust the dose cannot be performed, which causes a problem.

What solves these problems is the so-called easy-cutting process, in which fine holes are densely formed in the film.
It facilitates tear propagation between the micropores, facilitates unsealing with bare hands, and also enables adjustment of the shape of the unsealing, the area of the opening, and the like. A polyester film that has been subjected to easy-cut processing is particularly preferably used because it is easy to tear open with bare hands.

Usually, on the surface of the medicine packaging paper, information on medicines, such as prescription and dispensing date, is printed. For this reason, it is preferable to impart ink adhesion to the surface of the medicine packaging paper. If the wetting index of the film surface is low, the ink adhesion tends to decrease, and the surface tension of the film of the present invention is preferably 4
9 mN / m or more, more preferably 51 mN / m or more,
Most preferably, it is 53 mN / m or more.

When wrapping in a medicine packaging paper, it is preferable that visibility from the outside is good in order to confirm the contents. High visibility makes it possible to identify the drug from the outside, and at the time of dosing it can be easily checked on the spot whether or not the drug is intended for the individual, preventing drug mistakes and confirming the dose. Is also easy.

From this viewpoint, the haze of the polyester film of the present invention is preferably 10% or less, more preferably 8% or less, and particularly preferably 5% or less.

[0026]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In addition, various physical properties,
Characteristics are measured or defined as follows. In Examples, "%" means "% by weight". (1) Surface resistivity Yokogawa Hewlett-Packard's inner electrode 50 mm
1600 which is a concentric electrode with a diameter of 70 mm
8A is placed on the sample in an atmosphere of 23 ° C. and 50% RH,
A voltage of 100 V is applied, and 43
The volume resistivity of the sample was measured at 29A. (2) Wetting index According to JIS-K6768-1977, a prototype was flowed on the surface of the sample film using a wetting index reagent (manufactured by Nacalai Tesque), and the wettability was determined. (3) Haze According to JIS-7105, the haze of the film was measured with an integrating sphere turbidimeter NDH-20D manufactured by Nippon Denshoku Industries Co., Ltd. (3) Adhesiveness Toyo Ink Manufacturing Co., Ltd. Cerocolor printing ink CCS
Using T39 indigo, it is applied to the film surface so that the coating thickness after drying becomes 1.5 μm, and dried with hot air at 80 ° C. for 1 minute to obtain a film for evaluation. 23 films for evaluation
C. and humidity of 50% RH for 24 hours, and Nichiban Co., Ltd. cellotape (18 m
m width) is applied to a length of 7 cm so as to prevent air bubbles from entering, and a constant load is applied thereon with a 3 kg manual load roll.
After fixing the film, one end of the cellophane tape was connected to a weight of 500 g, and the weight naturally dropped a distance of 45 cm.
The evaluation is performed by a method in which a 0 ° peel test is started. Adhesiveness is evaluated and indicated based on the following five criteria.

Evaluation 5: No ink was peeled off from the cellophane tape surface.

Evaluation 4: Only less than 10% of the ink peels off the cellophane tape surface.

Evaluation 3: 10 to 50% of the ink is peeled off to the cellophane tape side.

Evaluation 2: 50% or more of the ink was peeled off from the cellophane tape.

Evaluation 1: The ink is completely peeled to the cellophane tape side.

In practice, a rating of 4 or more can be used without any problem. (5) Content Visibility According to a conventional method, the polyethylene sheet was bonded to a polyethylene sheet so that the polyethylene sheet was on the inner side, processed into a medicine packaging paper, and the content visibility was evaluated according to the following criteria.

Evaluation A: The packaged paper after processing is excellent in transparency,
The contents that can be easily confirmed. Evaluation B: The contents can be confirmed in the processed packaging paper. The evaluation C: The processed packaging papers in which it is difficult to confirm the contents. 6) Hand-cutting property The hand-cutting property of the medicine package paper sample processed in the same manner as in the section (5) was evaluated based on the following criteria.

Evaluation A: One that can be easily torn by hand Evaluation B: One that cannot be easily torn by hand (7) Ash test Drop ash of tobacco on the surface of the film sample, and place the film sample in the vertical direction. The state of adhesion of the ash after one rotation (360 degrees) was observed and evaluated according to the following criteria.

Evaluation A: A substance to which ash hardly adheres to the film Evaluation B: A substance to which ash slightly adheres to the film Evaluation C: A substance to which a large amount of ash adheres to the film (8) Comprehensive evaluation A five-point scale was given on a scale of 1 to 3, and a score of 3 or more was considered acceptable.

Example 1 (Production method of polyester chip) 100 parts of dimethyl terephthalate, 70 parts of ethylene glycol, and 0.07 part of calcium acetate monohydrate were placed in a reactor, heated and heated, and methanol was distilled off to carry out a transesterification reaction. Do
After the start of the reaction, it took about 4.5 hours to raise the temperature to 230 ° C., and the transesterification reaction was substantially completed.

Next, 0.04 part of phosphoric acid and 0.035 part of antimony trioxide were added, and polymerization was carried out according to a conventional method. That is, the reaction temperature is gradually increased to finally 280 ° C., while the pressure is gradually decreased to finally 0.05 mm
Hg. After 4 hours, the reaction was terminated, and the mixture was formed into chips according to a conventional method to obtain a polyester (A). The solution viscosity IV of the obtained polyester chip was 0.66. (Manufacturing method of antistatic masterbatch) To the polyester (A) was added 20 parts of sodium antisulphonic acid sodium salt to
% To prepare a polyester (B).

In producing the polyester (A), 1000 ppm of amorphous silica having an average particle diameter of 2 μm was added to prepare a polyester (C).

When producing the polyester (A), polyethylene glycol (molecular weight: 6000) is
% To prepare a polyester (D). (Production of polyester film) 57%, 3%, 30% of the above polyesters (A), (B), (C) and (D)
% And 10%, respectively, and the polyester (A) was melted at 295 ° C., and the mixed material was used as the outermost layer (surface layer), and the polyester (A) was used as the intermediate layer.
On a cooled casting drum, two types and three layers were co-extruded and cooled and solidified to obtain a non-oriented sheet. Next, the film is stretched 3.6 times in the longitudinal direction at 90 ° C., and then subjected to a heat treatment of 4 times at 90 ° C., transversely stretched, and 230 ° C. for 10 seconds through a preheating step in a tenter, to give a polyester film having a thickness of 19 μm. Obtained.

This polyester film is supplied between a processing roll having a surface with a projection for scratch processing protruding on the circumference and a receiving roll having a smooth surface, which are rotated in opposite directions at a constant speed to each other. After providing the micropores, the resultant was laminated with a polyethylene film to obtain a packaging material for medicine packaging paper containing a polyester film as a base material. The obtained packaging paper exhibited good antistatic properties, visibility of contents, hand-cutting properties, and ink adhesion, and exhibited favorable performance for use as a packaging paper.

Example 2 A packaging material for medicine packaging paper was obtained in the same manner as in Example 1 except that no fine holes were formed in the polyester film, and the characteristics were evaluated.

Example 3 A packaging material for medicine packaging paper was obtained in the same manner as in Example 1 except that the blending amount of the polyester (D) in the surface layer was changed to 5%, and its characteristics were evaluated.

Example 4 A packaging material for medicine wrapping paper was obtained in the same manner as in Example 1 except that the blending amount of the polyester (C) in the surface layer was changed to 40%, and its characteristics were evaluated.

Example 5 In Example 1, the raw material for the surface layer was polyester (A),
A packaging material for medicine packaging paper was obtained in the same manner as in Example 1 except that only (B) and (C) were used, and the characteristics were evaluated. The obtained packaging material had poor ink adhesion and could not be properly printed.

Example 6 A packaging material for medicine packaging paper was obtained in the same manner as in Example 1 except that the polyester (B) in the surface layer was changed, and the characteristics were evaluated. The obtained packaging material had a high haze, and it was difficult to visually recognize the contents.

Comparative Example 1 In Example 1, the raw material of the surface layer was polyester (A),
(C) and (D) alone, a packaging material for medicine packaging paper was obtained in the same manner as in Example 1 except that micropores were not provided in the obtained polyester film, and the characteristics were evaluated. Since the obtained packaging material was inferior in antistatic ability, the contents were easily attached to the surface of the packaging material, and the hand cutting property was poor.

The results obtained are summarized in Table 1 below.

[0048]

[Table 1]

[0049]

According to the present invention, a film using a medicine package which prevents adhesion of a drug or foreign matter, has good visibility of contents, has excellent adhesiveness to various inks, and has excellent openability. And the industrial value of the present invention is high.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E086 AB02 BA15 BB02 BB21 BB35 BB59 BB62 CA28 4F071 AA43 AF30Y AF39Y AF55Y AF56Y AH04 BC01

Claims (4)

[Claims] 1. A polyester film for medicine packaging paper, having a surface resistivity of 5 × 10 ¹² Ω / □ or less. 2. The polyester film for packaging paper according to claim 1, wherein the wetting index is 49 mN / m or more. 3. The polyester film according to claim 1, wherein the haze is 10% or less. 4. The polyester film for medicine packaging paper according to claim 1, wherein the polyester film is easily cut.