JPH11227840A - Ultraviolet ray protective film and shrink film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both transparency and ultraviolet ray protection characteristics in an ultraviolet ray protective film and a shrink film by using PEN and realize both inexpensively without degrading strength. SOLUTION: The ultraviolet ray protective film 1 comprises a base material 2 made of polyethylene terephthalate and a fine powder 3 made of polyethylene naphthalate dispersed therein. The shrink film is manufactured by imparting shrinkability to the ultraviolet ray protective film 1 at the time of or after manufacturing the film 1. Thus the obtained film can exhibit higher ultraviolet ray protection characteristics than a film made of a single PET body due to ultraviolet ray absorbing effects of dispersed PEN particles. In addition, two regions different in refractive index are formed in the film, and reflection of ultraviolet rays incident from the outside occurs on their interface, so that it is possible to reduce light which passes through the film and reaches inside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet protection film for protecting the contents from external ultraviolet rays when used for packaging and the like, and a shrink film having such ultraviolet protection properties and having a shrink property. The present invention relates to a colorless transparent film and a shrink film.

[0002]

2. Description of the Related Art When used for packaging, etc., as an ultraviolet ray protection film which absorbs ultraviolet rays and protects the contents from external ultraviolet rays, a polyethylene terephthalate (hereinafter, appropriately referred to as PET) material or a polyvinyl chloride material is used. With UV absorber mixed into a film, PET,
Films and polyvinyl chloride films coated with an ultraviolet absorber are widely used.

[0003] PET is a polymer synthesized by polycondensation of terephthalic acid or its dimethyl ester with ethylene glycol, and is widely used in fibers, films and molded products. At the present time, it is a polymer material that is rapidly spreading as a liquid container (bottle). It has features such as high strength, thermal stability, and chemical resistance, and the film is manufactured by melt extrusion and uniaxial or biaxial orientation.

[0004] Further, polyvinyl chloride is a polymer of a vinyl chloride monomer, is a colorless and odorless powder, has electrical insulation properties, water resistance and flame retardancy, and is a typical resin that can be processed into films and the like. . These PET and polyvinyl chloride films are relatively inexpensive, can have a shrink property through a process for imparting a proper shrink property, and can be used as a shrink film.

Accordingly, the above PET or polyvinyl chloride material kneaded with an ultraviolet absorber to form a film, or a PET film or polyvinyl chloride film coated with an ultraviolet absorber, can be appropriately processed. Thus, a shrink film having ultraviolet protection properties can be formed. And since the shrink film provided with these ultraviolet ray protection properties is relatively inexpensive as PET or polyvinyl chloride as its main constituent materials as described above,
It also has the feature of being relatively inexpensive.

As used herein, the term "ultraviolet ray protection properties" refers to at least the ultraviolet ray absorption properties of a film or the like that absorbs ultraviolet rays and suppresses the transmission of ultraviolet rays, and suppresses the transmission of ultraviolet rays by reflecting and scattering ultraviolet rays. It is used in a sense that includes the ultraviolet reflection characteristics of a film or the like.

[0007]

However, the above PET
Materials made by kneading and mixing an ultraviolet absorber with a material or polyvinyl chloride material, or those coated with an ultraviolet absorber on a PET film or polyvinyl chloride film,
It tends to have a slight yellow tint and is not colorless and transparent.

Accordingly, there is a problem that when used in packaging or the like, the contents are colored and appear. In the technical field where the color and design of cosmetics and other products and containers that store and fill them are very important factors, for example, protection of products such as makeup products and tools such as puffs, and filling and storing of products If you intend to use these colored films in container packaging, store the original color of the product
The result is that the design of the container to be filled is impaired.

[0009] As a result, such films or shrink films cannot be used for products or containers, albeit inexpensively, except in exceptional cases. When used for packaging etc. while being colorless and transparent,
As a film that can protect the contents from external ultraviolet rays,
There is a film made of polyethylene naphthalate (polyethylene 2,6-naphthalate, which is hereinafter appropriately referred to as PEN).

PEN has a naphthalene ring structure in the skeleton portion corresponding to the benzene ring skeleton portion contained in PET, and can provide a film having better strength, elastic modulus, heat resistance and gas barrier properties than PET. Material. As for its ultraviolet absorption characteristics, it has a characteristic that its absorption end extends to longer wavelengths than PET due to the contained naphthalene ring structure, but its effect and degree itself are visibly yellow. However, it is possible to form a substantially colorless and transparent film.

Therefore, if the film is made of PEN, it is possible to form an ultraviolet protection film which is colorless and transparent and has excellent ultraviolet absorption characteristics. However, the superior strength that is higher than PET is adversely affected, and PE
There is a problem in providing shrink properties to the N film. That is, PEN is too hard to have a shrink property, and cannot form a shrink film.

Further, since it is a more expensive material than PET, the use of a large amount may cause a problem when considering the cost of the product. Therefore, while having both excellent properties of transparency and ultraviolet protection properties, it cannot be used as it is for a shrink film for shrink packaging, and its use from the viewpoint of product protection is very limited. ing.

Accordingly, an object of the present invention is to provide a novel ultraviolet protection film and a shrink film which solve the above problems. Another object of the present invention is to use a PEN film to achieve both transparency and UV protection properties, and to provide sufficient shrinkability at low cost.

[0014]

According to the first aspect of the present invention,
The ultraviolet protection film is characterized in that a fine powder made of polyethylene naphthalate is dispersed in a base material made of polyethylene terephthalate. According to a second aspect of the present invention, in the shrink film, a shrink film is formed by dispersing a fine powder of polyethylene naphthalate in a base substrate made of polyethylene terephthalate, and is provided with shrinkage.

According to the first aspect of the present invention, it is possible to form a film by dispersing a fine powder of PEN having a high ultraviolet absorbing effect in PET having a low ultraviolet absorbing effect constituting a base material, The resulting film can exhibit higher UV protection properties than the film made of PET alone due to the UV absorbing effect of the dispersed PEN fine particles.

Further, by dispersing a fine powder of a different material in the base material, regions having different refractive indices are dispersed in the film. At the interface between the two regions having different refractive indices, reflection of ultraviolet light incident from the outside occurs, and it is possible to reduce the amount of light transmitted through the film and reaching the inside. At this time, PEN has good compatibility with PET, and when PEN fine powder is dispersed in a PET base material, the adhesion between the PEN fine particles and the PET base material is good, and the strength of the obtained film is a film composed of PET alone. There is no decrease compared to.

Furthermore, the use of relatively inexpensive PET as the base material makes it possible to reduce the amount of expensive PEN used, and it is possible to achieve both of the two features of an ultraviolet protection effect and a reduction in product cost. . From the above, in the film,
Using PEN, it is possible to achieve both transparency and ultraviolet protection properties, and to provide this at low cost.

According to the second aspect of the present invention, it is possible to use a film formed by dispersing fine powder of PEN having a high ultraviolet absorbing effect in PET having a low ultraviolet absorbing effect constituting a base material. The film used can exhibit higher UV protection characteristics than a film made of PET alone due to the UV absorption effect of the dispersed PEN fine particles.

In addition, such a film is formed by dispersing fine powder of a different material from a base material in a base material, thereby dispersing regions having different refractive indices in the film. At the interface, reflection of ultraviolet light incident from the outside occurs, and it becomes possible to reduce the amount of light transmitted through the film and reaching the inside. At this time, PE
N has good compatibility with PET.
When dispersed in a base material, the adhesion between the PEN fine particles and the PET base material is good, and the strength of the obtained film is not reduced as compared with a film made of PET alone.

Further, PET as a base material is a material which can be provided with a shrink property by an appropriate treatment. Therefore, a PET-based film formed by dispersing a fine powder of PEN can be used in a similar suitable treatment. It becomes possible to have the shrink property originating from. Furthermore, relatively inexpensive PE
By using T as a base material, it is possible to reduce the amount of expensive PEN used, and it is possible to satisfy different requirements such as an ultraviolet protection effect, a shrink property, and a reduction in product cost.

As described above, in the film, PEN is used to achieve both transparency and ultraviolet protection properties.
By using this, it is possible to make use of the properties of PET as a base substrate, to form a shrink film that is inexpensive and has sufficient shrink properties, and to provide this.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a sectional view showing a structure of an ultraviolet protection film according to a first embodiment of the present invention.

The ultraviolet protection film 1 according to the first embodiment of the present invention has a structure in which a fine powder 3 made of polyethylene naphthalate is dispersed in a base material 2 made of polyethylene terephthalate. FIG. 2 is a diagram illustrating the generation of an ultraviolet protection effect of the ultraviolet protection film 1 according to the first embodiment of the present invention. At this time, FIG.
2A schematically shows a state in which fine powder 3 made of polyethylene naphthalate dispersed in base material 2 absorbs ultraviolet light 4, and FIG. 2B shows polyethylene naphthalate dispersed in base material 2. The fine powder 3 is made to refract the ultraviolet rays 4 at the interface, and as a result, the ultraviolet protection film 1
Schematically shows how the light scatters the ultraviolet light 4.

As shown in FIG. 1, the ultraviolet protection film 1
Since the fine powder 3 of PEN having a high ultraviolet absorbing effect is dispersed, the PEN as shown in FIG.
Due to the ultraviolet light absorbing effect of the fine powder 3, it is possible to exhibit a higher ultraviolet protection characteristic than a conventional film consisting only of PET.

As shown in FIG. 2B, a fine powder 3 of PEN, which is a different material, is placed on a base substrate 2 made of PET.
Are dispersed in the ultraviolet protection film 1 to form two types of regions having different refractive indices composed of a base substrate portion and three fine powder portions. At the interface between the two types of regions having different refractive indexes, refraction / reflection of the ultraviolet light 4 incident from the outside occurs, and it is possible to reduce the amount of light that passes through the ultraviolet protection film 1 and reaches the inside.

The scattering of ultraviolet light entering from the outside, which occurs at the interface between the two regions having different refractive indices, lowers the visible light transmittance of the ultraviolet protection film if it also scatters visible light. Although it can cause fogging, the UV protection film is usually very thin and practically not visibly fogging. At this time, PEN has good compatibility with PET, and when PEN fine powder 3 is dispersed in the base material 2 made of PET, PEN
The adhesiveness between the EN fine powder 3 and the base substrate 2 made of PET is good, and the strength of the obtained ultraviolet protection film 1 is hardly reduced as compared with the conventional film made of PET alone.

Further, a relatively inexpensive PET is used as the base material 2.
By using the PEN, it is possible to reduce the amount of expensive PEN used, and it is possible to achieve both of the two features of the UV protection effect and the suppression of the product cost. Next, the manufacture of the ultraviolet protection film 1 according to the first embodiment of the present invention will be described.

In the manufacture of the ultraviolet protection film 1 according to the first embodiment, the fine powder 3 of PEN is not melted and dissolved in the base substrate 2 made of PET.
PET thermally softened at a temperature lower than the melting point of PEN
Use Fine particles 3 of PEN are added to PET maintained at such a temperature and dispersed appropriately, and the UV protective film 1 is produced by using such a mixture, for example, by melt extrusion and monoaxial or biaxial orientation.

At this time, the size of the PEN fine powder 3 to be dispersed is smaller than the thickness of the produced ultraviolet protection film 1 according to the thickness of the produced ultraviolet protection film 1 which does not cause irregularities, that is, the thickness of the produced ultraviolet protection film 1. Any diameter may be used. The size of the dispersed PEN fine powder used in the production of a shrink film to be described later is such that no irregularities are generated in the shrink film even during stretching in the step of imparting shrink properties, that is, during stretching. According to the thickness of the shrink film, the outer diameter may be smaller than the thickness.

In consideration of wavelength characteristics of light to be reflected / scattered and visible light to be transmitted, the dispersed PEN
It is also possible to design the particle size of the fine powder. From the above,
In an ultraviolet protection film, it is possible to provide both transparency and ultraviolet protection characteristics at a low cost. Such an ultraviolet protection film can be used as a film or the like that is stored in a container together with a makeup cosmetic to protect the makeup cosmetic.

(Embodiment 2) Next, a shrink film according to a second embodiment of the present invention will be described. FIG.
FIG. 4 is a cross-sectional view illustrating a structure of a shrink film according to a second embodiment of the present invention.

The shrink film 11 according to the second embodiment of the present invention comprises a film 14 composed of a polyethylene naphthalate fine powder 13 dispersed in a polyethylene terephthalate base material 12 to impart shrinkage. It has shrink properties. That is, the shrink film 11 according to the second embodiment of the present invention.
Takes advantage of the fact that the ultraviolet protection film 1 according to the first embodiment uses a PET material capable of imparting shrinkage to the base material, and the shrinkage is imparted to the base material as described below. ,It is configured.

Therefore, the ultraviolet protection film 1 according to the first embodiment is similarly provided without deteriorating the characteristics. In other words, since the shrink film 11 disperses the fine powder 13 of PEN having a high ultraviolet absorbing effect similarly to the ultraviolet protection film 1 according to the first embodiment, the ultraviolet protection of the PET constituting the base material 12 is performed. Although the effect is low, the ultraviolet absorption effect of the PEN fine powder 13 makes it possible to exhibit high ultraviolet protection properties similar to those of the above-mentioned ultraviolet protection film 1 as compared with the conventional film consisting only of PET or polyvinyl chloride.

Further, the base material 12 made of PET is
By dispersing the fine powder 13 of PEN which is a different material, two types of regions having different refractive indices composed of the base substrate portion and the fine powder 13 portion are formed in the shrink film 11 in a dispersed manner. At the interface between the two types of regions having different refractive indexes, refraction and reflection of ultraviolet light incident from the outside occur, and it is possible to reduce light that passes through the shrink film 11 and reaches the inside.

In addition, the scattering of externally incident ultraviolet light generated at the interface between the two types of regions having different refractive indices lowers the visible light transmittance of the ultraviolet protection film when it also scatters visible light. Although it can cause haze, the UV protection film is usually very thin and practically not visibly fogged. At this time, P
EN has good compatibility with PET, and PEN fine powder 13
Is dispersed in a base material 12 made of PET,
The adhesion between the EN fine powder 13 and the base substrate 12 made of PET is good, and the resulting shrink film 1
The strength of No. 1 hardly decreases as compared with the conventional film consisting only of PET.

Further, a relatively inexpensive PET is used as the base material 1.
By using No. 2, it is possible to reduce the amount of expensive PEN used, and it is possible to satisfy different requirements of providing an ultraviolet protection effect, a shrink property, and suppressing a product cost. Next, the manufacture of the shrink film 11 according to the second embodiment having the above performance will be described.

The shrink film 11 of the second embodiment
Is manufactured using a film having the same or similar structure as that of the ultraviolet protection film 1 according to the first embodiment. That is, PET which is thermally softened at a temperature lower than the softening point of PEN and slightly lower than the softening point of PET is used as a base material, and P is added to the PET.
EN fine powder 13 is added and dispersed appropriately, and the obtained resin mixture is stretched in one direction or in two directions,
Thereafter, it is cooled and fixed in a state in which the internal strain stress is left, so that shrinkability is imparted to manufacture.

Alternatively, a film having the same structure as that of the ultraviolet protection film 1 according to the first embodiment manufactured by an appropriate molding method is used, and is subjected to heat stretching in one direction or two directions in the vertical and horizontal directions. Subsequently, it is cooled and fixed in a state where the internal strain stress is left, thereby performing the manufacturing. When the shrink film manufactured as described above is heated again, it undergoes thermal contraction so as to remove residual strain. If this heat shrinkage is used, the article to be packaged is roughly (roughly) wrapped and then heated to shrink the shrink film to obtain a tightly packed package.

The shrink film 11 comprises
The size of the PEN fine powder 13 to be dispersed is such that, even in a stretched state for imparting shrink properties, no irregularities occur in the shrink film 11, that is, according to the thickness of the shrink film 11 at the time of stretching. Any material having an outer diameter smaller than the thickness may be used. In addition, in consideration of the wavelength characteristics of light to be reflected and scattered, the dispersed PEN fine powder 1
It is also possible to design a particle size of 3.

As described above, in the film, PEN is used to achieve both transparency and ultraviolet protection properties.
By using this, it is possible to make use of the properties of PET as a base substrate, to form a shrink film that is inexpensive and has sufficient shrink properties, and to provide this. Such a shrink film can be used as a shrink film for wrapping tools such as makeup products and puffs.

[0041]

According to the first aspect of the present invention, the resulting film can exhibit higher UV protection characteristics than the film made of PET alone due to the UV absorption effect of the dispersed PEN fine particles. Further, two regions having different refractive indices are formed in the film, and reflection of ultraviolet light incident from the outside occurs at an interface between the two regions, so that light that passes through the film and reaches the inside can be reduced.

At this time, the strength of the obtained film is PE
There is no decrease as compared with a film consisting of T alone. Further, it is possible to achieve both of the two features of the ultraviolet protection effect and the suppression of the product cost. From the above, in the film,
By using PEN, it is possible to achieve both transparency and ultraviolet protection properties, and to provide it at low cost.

According to the second aspect of the present invention, the film to be used can exhibit higher UV protection characteristics than the film made of PET alone due to the UV absorbing effect of the dispersed PEN fine particles. In addition, regions having different refractive indices are dispersedly formed in the film, and reflection of ultraviolet light incident from the outside is caused, so that light transmitted through the film and reaching the inside can be reduced.

At this time, the strength of the obtained film is PE
There is no decrease as compared with a film consisting of T alone. In addition, it is possible to have a shrink property derived from an appropriate treatment. Further, it is possible to satisfy different requirements such as an ultraviolet protection effect, a shrink property and a reduction in product cost.

As described above, in the film, PEN is used to achieve both transparency and ultraviolet protection properties.
By using this, it is possible to make use of the properties of PET as a base substrate, to form a shrink film that is inexpensive and has sufficient shrink properties, and to provide this.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a structure of an ultraviolet protection film according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating the generation of an ultraviolet protection effect of the ultraviolet protection film according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a structure of a shrink film according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 UV protection film 2,12 Base material 3,13 Fine powder 4 UV 11 Shrink film 14 Film

Claims (2)

[Claims] 1. An ultraviolet protection film, wherein a fine powder of polyethylene naphthalate is dispersed in a base material of polyethylene terephthalate. 2. A shrink film comprising a film formed by dispersing a fine powder of polyethylene naphthalate in a base substrate made of polyethylene terephthalate, and having a shrinkage property.