JPH09300540A - Iridescent reflecting film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a tough film generating no ply separation by setting respective ultra-thin layers to a thickness almost equal to the wavelength of visible light and constituting the mutually adjacent ultra-thin films of two kinds of specific different materials and cutting the film into fine yarn to utilize the same as a decorative spinning material. SOLUTION: The thickness of each of ultra-thin layers constituting a transparent multilayered film made of a thermoplastic resin is almost set to a wavelength of visible light and mutually adjacent ultra-thin films are constituted of two kinds of different materials. One resin is an acrylic resin and other resin is a polymer blend of a polybutylene terephthalate elastomer being polybutylene terephthalate or a polybutylene terephthalate/polyethylene glycol copolymer and a linear low density polyethylene. Therefore, a tough film generating no ply separation and having beautiful iridescent gloss is obtained and can be used as a decorative spinning material.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an iridescent reflection film comprising an ultrathin film having a thickness of about the wavelength of visible light,
The present invention relates to an iridescent reflection film which is laminated with other materials such as paper and cloth to be used as a decorative material, and is cut into fine wires to be used as a decorative spinning material such as gold thread and silver thread.

[0002]

2. Description of the Related Art Iridescent reflection film has a refractive index of 0.0
It is possible to obtain 20 or more layers of two kinds of transparent ultrathin films which are different from each other by 3, preferably 0.06 or more. However, since the conventional iridescent reflection film has poor adhesion between the layers, a delamination phenomenon tends to occur. In addition, the film itself is fragile and has a drawback that it is easily broken during use. Japanese Patent Publication No. 40681/1992 discloses an iridescent reflection film in which ultrathin layers of polybutylene terephthalate and polymethyl methacrylate are alternately laminated. According to this iridescent reflection film, the adhesion between the layers was improved and the problem of delamination was solved, but the strength of the film was still insufficient. Therefore, the strength was insufficient to use it in the form of a thread, and it was cut into a thread after being attached to a polyester film or the like.

[0003]

The present invention is disclosed in Japanese Patent Publication No.
Delamination does not occur in the resin constitution of the film different from the film disclosed in 40681, and a tougher film can be obtained and directly cut into thin thread shapes, which can be effectively used as a decorative spinning material. The purpose is to obtain an iridescent reflection film.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and its constitution is composed of at least 20 ultra-thin film layers having a substantially uniform thickness, and both skins have a slightly thick skin. In a transparent thermoplastic resin multilayer film having layers, the thickness of each ultrathin layer excluding the skin layer is about the wavelength of visible light, and the ultrathin films adjacent to each other are 2
Composed of different kinds of materials, one resin is acrylic resin and the other resin is polybutylene terephthalate, polybutylene terephthalate elastic body which is a copolymer of polybutylene terephthalate and polyethylene glycol, and linear low density polyethylene. It is a polymer blend of.

In the present invention, an acrylic resin is used for one of the ultra-thin layers that are alternately laminated, and a polymer blend of polybutylene terephthalate, a polyethylene terephthalate elastic body, and linear low density polyethylene is used for the other layer. By using it, it has succeeded in improving the adhesiveness of both layers and further improving the strength of the whole film. By blending the elastic body and the linear low-density polyethylene, the synergistic effect improves the overall elasticity and imparts impact resistance to the entire film. here,
As the polyethylene terephthalate elastic body, a copolymer of polyethylene terephthalate and polyethylene glycol is preferable.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION An acrylic resin is used for one layer of the present invention. For example, a polymer of a relatively low molecular weight acrylic monomer such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate can be used. In some cases, a copolymer containing the above-described monomer and another copolymerizable monomer as a main component including an acrylic resin is included.

For the other layer, a polymer blend of polyethylene terephthalate (component A), polyethylene terephthalate elastic body (component B) and linear low density polyethylene (component C) is used. As the polyethylene terephthalate of the component A, those obtained by a catalytic polycondensation reaction between 1,4-butanediol and terephthalic acid or dimethyl terephthalate are preferable. The polyethylene terephthalate elastic body of the B component contains an ethylene terephthalate group and achieves the object of the present invention as long as it is a polymer having elasticity, but a copolymer of polyethylene terephthalate and polyethylene glycol, preferably a block copolymer is used. Used. As the linear low-density polyethylene of the component C, various commercially available linear low-density polyethylenes can be used. Generally, the specific gravity is 0.85 to 0.93 and the melt index (hereinafter referred to as MI) is 1 to 50.

The mixing ratio of A component, B component and C component is
A component: B component: C component = 80 to 95: 3 to 15: 0.
5-5% by weight, preferably 85-93: 5-10: 1-1
4% by weight. When the proportion of the component B exceeds 15% by weight, transparency is impaired. When the proportion is less than 3% by weight, the impact resistance is not improved, and the strength of the film as a whole does not increase. If the amount of the component C exceeds 5% by weight, transparency is impaired, and 0.5% by weight
If it is less than 30, the impact resistance is not improved. The three components A, B and C are melt-kneaded and used as one ultrathin layer of the film of the present invention.

The film of the present invention combines a feed block for collecting the resin melt from each of the two extruders and arranging them in the desired layer pattern and a conventional single manifold flat film die. It is manufactured by the chilled roll casting method. This feedblock is used to form a two component alternating layer. A very thin layer of resin flow flows through a single manifold flat film die where each layer is simultaneously expanded to the width of the die and thinned to the exit die thickness of the final die. The layer thickness distribution can be changed by inserting different feed board modules. Usually, the outermost layer is thicker than the other layers, and this is called a skin layer.

The acrylic resin layer occupies 30 to 50% of the total, and the layer composed of the polymer blend of the component A, the component B and the component C occupies 50 to 70% of the total. In order to obtain a beautiful iridescent luster, the refractive index of the acrylic resin layer should be 3
A difference of at least 0.03, preferably at least 0.06, from the refractive index of the other layer which is the component mixture layer is required. The ultrathin layer has a thickness of about the wavelength of visible light. That is, 3800
~ 8000Å, 20 layers or more, preferably 70
It is laminated in more layers.

[0011]

Example 1 Polymethylmethacrylate (PMMA) was used as one layer having a lower refractive index. As the resin having a higher refractive index, A component: polybutylene terephthalate (PBT) viscosity 1 Pa · s 90 wt% B component: copolymer of PBT and polyethylene glycol (using HYTREL 7246 manufactured by DuPont, USA) 7 wt. % C component: (with a density of 0.92, MI, 2) 3% by weight was blended, kneaded well and fed to the feed block with an extruder. PMMA was supplied to another feed block by another extruder, the mixed resin was used as the surface layer, the ratio of the high refractive index resin: low refractive index resin was 2: 1, and the alternate laminated ultra thin film 123 layers were formed by the casting method. An iridescent reflection film of the present invention having a total thickness of 18 μ was obtained. The refractive index of the mixed resin of A component, B component and C component was 1.49.

In this film, the PMMA layer had a thickness of 0.07 μm, and the mixed resin layer had a thickness of 0.15 μm.
This film has good iridescent reflection properties,
The longitudinal strength MD measured according to K 7128 is 2
8. The transverse strength TD was 24, and when it was cut into a tough and thin thread without delamination, it could be twisted into the thread as it was, and as a result, a spun material with a beautiful gloss could be obtained.

Comparative Example 1 An iridescent reflection film was produced in the same manner as in Example 1 except that PBT was used as the mixed resin layer having the higher refractive index. The obtained film had a longitudinal strength MD of 10 and a transverse strength TD of 8, and was a film that was not easily peeled off but had a marked decrease in strength and was easily broken. Therefore, in order to obtain a spun material, the film itself had to be lined and then cut into fine threads.

[0014]

EFFECT OF THE INVENTION PMMA is used as a low refractive index film, and a polymer blend of A component, PBT, B component, PBT elastic body, C component, and linear low density polyethylene is used as a high refractive index film. According to the present invention in which ultra-thin films of 20 layers or more are alternately laminated, it is possible to obtain a film which is tough and has a beautiful iridescent luster without delamination.

Claims (3)

[Claims] 1. In a multilayer film made of a transparent thermoplastic resin, which comprises at least 20 ultrathin layers having a substantially uniform thickness, the thickness of each ultrathin layer is about the wavelength of visible light, The ultra-thin film adjacent to is composed of two different materials, one of which is an acrylic resin and the other is a polymer blend of polybutylene terephthalate, polybutylene terephthalate elastic and linear low density polyethylene. An iridescent color reflective film. 2. The blending ratio of polybutylene terephthalate: polybutylene terephthalate elastic body: linear low density polyethylene of the other resin is 80 to 95: 3 to 15:
The iridescent reflection film according to claim 1, which is 0.5 to 5% by weight. 3. The iridescent reflection film according to claim 1, wherein the polybutylene terephthalate elastic body is a copolymer of polybutylene terephthalate and polyethylene glycol.