JP2000238875A - Sanitary goods individual packaging film - Google Patents

Abstract

(57) [Abstract] [Problem] It has a beautiful pearly luster and soft touch,
Provided is a film for individually wrapping sanitary goods, which has high concealing properties for the sanitary goods to be packaged. SOLUTION: Melt flow rate (MFR) is 5-5.
A hygienic product individual packaging film comprising a polyolefin-based resin foamed layer of 0 g / 10 min and a non-transparent non-foamed layer of a polyolefin-based resin containing a pigment, and coextruded with a T-die to a thickness of 20 to 100 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film for individual packaging of sanitary articles suitably used for individual packaging of napkins, disposable diapers and the like.

[0002]

2. Description of the Related Art Conventionally, sanitary articles such as napkins and disposable diapers are often individually packaged with a plastic film for reasons of convenience and hygiene. Thermoplastic polyolefin-based resins are widely used as plastic films for individual packaging of these sanitary articles.

As one of packaging materials, Japanese Patent Application Laid-Open No. 61-13 / 1986
No. 0025 discloses a method for producing a foamed film that can be suitably used for a highly rigid packaging material, a mat, a table cloth, and the like. The above-mentioned foamed film is composed of three layers of a non-foamed layer of polyolefin or an inorganic-containing polyolefin as an inner and outer layer, and a foamed layer of a polyolefin or an inorganic-containing polyolefin as an intermediate layer. This method enables stable production of a product that could not be produced stably due to so-called build-up caused by perforation due to foaming, film breakage, or deposition near the die discharge port.

[0004]

However, in the invention described in the above-mentioned publication, the melt flow rate (MFR) of the polyolefin used is 1 g / 10 min. Although it is low and can be applied to the production of highly rigid packaging materials, mats, tablecloths, etc., it manufactures thin films for sanitary products with a normal thickness of 100 μm or less used for individual packaging films for sanitary goods. If you do, it becomes a problem. Further, such a thin film is not applicable at all because there is a problem that the concealing property of the sanitary goods to be packaged is deteriorated.

The present invention has been made in view of the above facts, and has as its object to provide a beautiful pearly luster and a soft tactile sensation for a sanitary article to be packaged. An object of the present invention is to provide a film for individual packaging of hygiene articles having high concealing properties.

[0006]

The film for individually packaging sanitary ware of the present invention comprises a foamed layer of a polyolefin resin having an MFR of 5 to 50 g / 10 minutes and an opaque non-foamed layer of a polyolefin resin containing a pigment. Consisting of 20 to 10
It is formed by co-extrusion of a T-die to 0 μm.

[0007] The polyolefin resin used for the foamed layer and the non-foamed layer of the film for individual packaging of sanitary articles of the present invention comprises:
Although not particularly limited, for example, ultra-low-density polyethylene, low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, polypropylene, polypropylene alloy alloy, ethylene-propylene rubber, ethylene -Methyl methacrylate copolymer, ethylene-vinyl acetate copolymer,
Examples include an ethylene-acrylic acid copolymer and an ethylene-methacrylic acid copolymer. These polyolefin-based resins may be used alone or in combination of two or more.

[0008] The MFR of the polyolefin resin used in the present invention is measured according to JIS K 7210. If the MFR of the polyolefin resin used for the foamed layer is less than 5 g / 10 minutes, 100 μm
In the following foam, the bubble diameter to be generated is large, the foaming state of the foamable resin composition discharged from the mold is unstable,
In particular, a foam having a thickness of 50 μm or less cannot be manufactured due to frequent occurrence of pinholes. On the other hand, if the MFR exceeds 50 g / 10 minutes, the melt viscosity of the polyolefin-based resin becomes low and molding becomes difficult. In addition, foaming during foaming is large, and it is possible to obtain a foam in which fine bubbles are uniformly dispersed. Because it is difficult, the MFR of the polyolefin resin used for the foamed layer is limited to the above range.

The foaming agent used for the foamed layer is not particularly limited, and may be a chemical foaming agent or a physical foaming agent. For example, examples of the chemical foaming agent include azodicarbonamide, N, N′-dinitrosopentamethylenetetramine, 4,4′-oxybis (benzenesulfonylhydrazide) as an organic type, and sodium hydrogen carbonate as an inorganic type. . Examples of the physical foaming agent include butane, pentane, hexane, heptane, nitrogen, and carbon dioxide. As the chemical foaming agent, a foaming aid may be used as needed for adjusting the decomposition temperature. As these foaming assistants, for example, urea compounds,
Zinc compounds and the like can be mentioned.

The amount of the foaming agent to be added to the polyolefin resin is from 1.1 to 3.0 in accordance with the type of the foaming agent and the use of the film for packaging personal hygiene articles used.
The expansion ratio is determined so as to be in the range of 2 times.

The MFR of the polyolefin resin used for the non-foamed layer is preferably 1 to 10 g / 10 minutes.
When the MFR is less than 1 g / 10 min, the difference in melt viscosity between the polyolefin resin used in the foamed layer and the melt viscosity becomes too large, which may cause layer cracking and other molding defects between the two layers, and exceed 10 g / 10 min. In such a case, the melt viscosity may be low and molding may be difficult.

The pigment used in the non-foamed layer is not particularly limited, but preferably a pigment having a large hiding power is selected according to the Japanese Sanitary Goods Standard. Examples of these pigments include calcium carbonate, talc, clay, kaolin, silica, diatomaceous earth, magnesium carbonate, magnesium sulfate, barium sulfate, calcium sulfate, aluminum hydroxide, zinc oxide, titanium oxide, alumina, zeolite, silicate clay, and the like. Is mentioned. These may be used alone or in combination of two or more. In addition, those pigments which have been treated in advance with a silane coupling agent such as vinyltriethoxysilane or vinyltrimethoxysilane or a surface treatment agent such as a resinous surface modifier may be used.

The amount of the pigment to be added to the polyolefin resin is determined by the hiding power of the pigment used and the use of the film for individually wrapping sanitary articles, but is preferably 5 to 70% by weight, more preferably 5 to 70% by weight. Is from 10 to 50% by weight.

The above-described polyolefin-based resin and foamable polyolefin-based resin composition are co-extruded with a T-die to form a personal hygiene article packaging film. The configuration of the personal hygiene article packaging film is composed of a multilayer film of two or more layers such as a non-foamed layer / foamed layer or a non-foamed layer / foamed layer / non-foamed layer. It has a pearly surface. The thickness of the multilayer film is preferably 20 to
100 μm, and the thickness ratio of the non-foamed layer and the foamed layer is:
The ratio of the total thickness of each layer is 3: 1 to 1: 3. In particular, when the multilayer film is formed by a co-extrusion method, the interface between the non-foamed layer and the foamed layer is intricate, and it is difficult to accurately grasp the thickness of each layer. The thickness ratio between the foamed layer and the foamed layer represents the weight ratio of the polyolefin resin used for each of the non-foamed layer and the foamed layer.

The multilayer film thus formed has a unique and beautiful pearly glossy appearance. In particular, the multilayer film having the structure of non-foamed layer / foamed layer / non-foamed layer is foamed at the time of extrusion molding. In addition to having a particularly smooth finish on the surface of the layer, it has a particularly beautiful pearly luster, the foamed layer provides sufficient cushioning to protect the packaged object, and the opaque non-foamed layer containing the pigment is In addition, the concealment of the object to be packaged is achieved, and the pearly gloss is imparted more clearly.

A photo-curing type, which is preferably cured on the surface of the non-foamed layer of the obtained multilayer film (one surface of the non-foamed layer having a non-foamed layer on both sides, preferably by irradiation with an electron beam or ultraviolet rays) A silicone release agent layer is formed. When forming the photocurable silicone-based release agent layer, the surface of the non-foamed layer of the multilayer film may be subjected to a surface treatment such as a corona discharge treatment.

The means for applying the photocurable silicone release agent to the multilayer film is not particularly limited,
For example, an offset gravure coater, a method of directly applying a photocurable silicone release agent to the surface of a non-foamed layer of a multilayer film using a reverse offset gravure coater, or a photocurable silicone release agent, for example, isopropyl A method of applying a solution diluted with a solvent having little adverse effect on a multilayer film such as alcohol, ethyl acetate, and cyclohexane using a direct gravure coater may be used. In the latter case, the quality of the coating film can be stably formed, especially when the coating amount is low.

The coating amount of the photocurable silicone release agent is as follows:
0.05 to 1.0 g / m ² , preferably 0.1 to 0.8
g / m ² . If the coating amount is less than 0.05 g / m ² ,
It is difficult to apply a photocurable silicone-based release agent uniformly, and if it exceeds 1.0 g / m ² , it is economically disadvantageous and the amount of irradiation of electron beam or ultraviolet light becomes large, The heat generated is not preferable because the multilayer film shrinks.

The film for individually packaging sanitary goods according to the present invention is constituted as described above, and is cut in advance into a size capable of sufficiently covering the sanitary goods, for example, cut into two layers in a chiral manner.
The sanitary ware is sandwiched between the non-foamed layers of the individual hygiene article individual packaging films or between the silicone release agent layers when the silicone release agent layer is provided, and the surroundings are sealed with a heat sealer or the like. It is used in a hermetically sealed package.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to examples.

(Example 1) Foamed layer / non-foamed (opaque)
For personal hygiene articles comprising a layer and a release agent layer, wherein the foamed layer is a linear low-density polyethylene (trade name “Ultzex 2010C” manufactured by Mitsui Chemicals, Inc., MFR =
(10 g / 10 min) 100 parts by weight of a foaming resin composition comprising 0.5 parts by weight of a blowing agent (azodicarbonamide), and a non-foaming layer made of a low-density polyethylene (manufactured by Asahi Kasei Corporation, trade name "Suntech F1920", MFR) = 2g / 10min)
A resin composition comprising 100 parts by weight and 5 parts by weight of a white pigment (titanium oxide) was subjected to T-die 2 at a foaming ratio of about 2 times.
A 35 μm thick pearly glossy two-layer film is formed by a layer co-extrusion method, and the surface of the non-foamed layer is subjected to corona discharge treatment. The composition was applied at 5 g / m ² and irradiated with ultraviolet rays to form a release agent layer, thereby producing a film for individually packaging sanitary articles.

(Example 2) Non-foamed (transparent) layer / foamed layer / non-foamed (non-foamed) layer in which a non-foamed (transparent) layer was formed on the exposed surface of the foamed layer of the personal hygiene article packaging film of Example 1. See through)
A film for individual packaging of sanitary ware comprising a layer and a release agent layer, wherein a low-density polyethylene (manufactured by Asahi Kasei Corporation, trade name “Suntech F1920”, trade name: MFR =
2 g / 10 min.) And forming a 35-μm-thick high-grade pearly glossy three-layer film in the same manner as in Example 1 except that the T-die three-layer co-extrusion method was used. The surface of the non-foamed layer on the side to be treated is subjected to corona discharge treatment, and the treated surface is coated with an ultraviolet-curable silicone release agent at a solid content of 0.5 g /
m ² and irradiated with ultraviolet rays to form a release agent layer, thereby producing a film for individual packaging of sanitary articles.

(Comparative Example 1) In place of the linear low-density polyethylene of the foam layer of the film for individually packaging sanitary articles of Example 2,
A low-density polyethylene (manufactured by Asahi Kasei Corporation, trade name “Suntech F1920”, MFR = 2 g / 10 min) was used and a thickness of 35 μm was obtained by a three-layer T-die coextrusion method in the same manner as in Example 2.
m for personal hygiene article packaging film,
The cell diameter of the foamed layer became large, and a hole was formed during extrusion, so that a film could not be formed. In addition, although the thickness was increased step by step to 100 μm, an attempt was made to form a film.
Similarly, there was a hole during extrusion and the film could not be formed.

(Comparative Example 2) Low-density polyethylene (manufactured by Asahi Kasei Corporation, trade name "Suntech F1920", MFR = 2 g)
A resin composition comprising 80 parts by weight, 20 parts by weight of high-density polyethylene (trade name “HY540” manufactured by Nippon Polychem Co., Ltd.) and 5 parts by weight of a white pigment (titanium oxide type)
An opaque polyethylene film having a thickness of 30 μm is formed by a die extrusion method, embossing is performed on the front surface, a release agent layer is formed on the rear surface in the same manner as in Example 1, and a film for individually packaging sanitary goods is formed. Produced.

In order to evaluate the performance of the individual packaging film for sanitary goods obtained in the above Examples and Comparative Examples, the film was previously cut into a size capable of sufficiently covering a sanitary napkin, and cut into two pieces enantiomerically. An adhesive sample of a sanitary napkin was applied between the photocurable silicone release agent layers of the individual sanitary napkin packaging films, and the package was hermetically sealed using a heat sealer to produce an evaluation sample.

The individual packaging film for sanitary articles and the above-mentioned individual packaging samples were evaluated for comfort and appearance during use by the following methods. The evaluation results are shown in Table 1.

1. Opacity of the packaged object: Good when the hygiene article inside the individual package sample is concealed from the outside to the extent that it cannot be seen through (good). Was evaluated. Comparative Example 1
Was excluded from the evaluation.

2. Appearance quality: Has a beautiful pearly luster and soft touch, makes the surface that gives a luxurious feel good (◎), matte by embossing, and the sticky touch of the plastic film is gone, The surface giving a feeling of lightly-applied practical packaging was evaluated as normal (O). Note that Comparative Example 1 was excluded from the evaluation, and the cause was shown in parentheses.

3. General comment: Combining the first and second terms,
The evaluation was performed on a three-point scale: comprehensively good (◎), reasonably good quality (○), and unmanufacturable (x).

[0030]

[Table 1]

[0031]

The film for individually packaging sanitary articles of the present invention is
In addition to a beautiful pearly glossy surface and a soft and resilient texture, the inside of the individual package containing the sanitary goods is concealed from the outside so that it cannot be seen through. It has comfort during use.

Continued on the front page F term (reference) 3E068 AA22 AB02 AB03 AC05 AC07 AC10 BB02 CC26 CE05 DE01 EE37 4C003 GA08 4F100 AA21 AK03A AK03B AK06 AK63 BA02 CA13B DJ01A EH20 GB15 JA06A JN02B YY00 YY00A

Claims (1)

[Claims] 1. A melt flow rate (MFR) of 5 to 5
A hygienic product individual packaging film comprising a polyolefin-based resin foamed layer of 0 g / 10 min and a non-transparent non-foamed layer of a polyolefin-based resin containing a pigment, and coextruded with a T-die to a thickness of 20 to 100 μm.