JPH07251479A - Laminated metal deposited film - Google Patents

Abstract

PURPOSE:To provide a polypropylene metal deposited film with outstanding size stability, evaporation processing characteristic and superb gas barrier properties after high-speed bag preparation, suitable for width enlarging an winding in large roll. CONSTITUTION:A material for a metal deposited film is a polypropylene laminated film with a core layer having a thickness equal to at least 10% of the entire thickness as a crystallizable propylene with a high stereoregularity of at least 0.970.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polypropylene-based metal vapor deposition film. More specifically, it relates to a polypropylene-based metal vapor deposition film having excellent dimensional stability, vapor deposition processability, and gas barrier property.

[0002]

2. Description of the Related Art In recent years, metal-deposited films obtained by vapor-depositing a metal on a plastic film have been widely used for gold and silver threads, construction materials, and packaging materials by taking advantage of their excellent decorative properties, gas barrier properties, and light blocking properties. . In particular, aluminum-vapor-deposited polypropylene film has excellent surface gloss and low-temperature heat-sealing properties, and as a laminated film laminated with biaxially oriented polypropylene film or polyester film, its application is expanding mainly for snack confectionery packaging and food packaging. .

[0003]

In order to improve production efficiency, a method for producing a metallized film requires a wider width and a longer winding, and an anti-blocking property that can endure a long winding even on a raw film. And improvement of rigidity is needed. In addition, the bag-making process of the metal vapor deposition film has been accelerated, and a large tension of the processing machine causes fine cracks in the vapor deposition film to deteriorate the gas barrier property. An object of the present invention is to provide a polypropylene-based metal vapor deposition film which is excellent in dimensional stability and vapor deposition processability capable of coping with widening and long winding, and a gas barrier property after high-speed bag making.

[0004]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have found that a core layer having a thickness of 10% or more (P) is used as a raw film of a metal vapor deposition film. Knowing that the intended purpose can be achieved by using a polypropylene laminated film, which is a crystalline propylene-based polymer having a high stereoregularity of 0.970 or more,
Furthermore, they have found that a more preferable metal vapor deposition film can be obtained by blending a specific aluminosilicate in the surface layer of the above-mentioned laminated film, and have completed the present invention. A crystalline propylene-based polymer or a crystalline propylene-based copolymer used for the (A) layer and the (C) layer of a laminated film in which three layers (A) / (B) / (C) used in the present invention are laminated in this order. The polymer is, for example, a crystalline polymer obtained by homopolymerization of propylene in the presence of a Ziegler-Natta type catalyst, or copolymerization with ethylene or other α-olefin containing propylene as a main component, and these crystalline polymers. It is a polymer obtained by graft-polymerizing an unsaturated carboxylic acid or an anhydride thereof in a combination, or a mixture selected from the above various polymers.

The crystalline propylene polymer used for the layer (B) of the laminated film has an isotactic pentad fraction (P) of 0.9 as measured by ¹³ C-NMR.
70 or more highly crystalline propylene polymer, for example, a method described in Japanese Patent Publication No. 1-48922, that is, a solid product obtained by reacting an organoaluminum compound with titanium tetrachloride, It is obtained by polymerizing propylene in the presence of a catalyst in which a product obtained by reacting a tellurium with titanium tetrachloride is combined with a dialkylaluminum monohalide and an aromatic carboxylic acid ester. The crystalline propylene polymer used in the layer (B) has a (P) of less than 0.970 or a (P) of 0.9.
If the thickness of the layer (B) is less than 10% of the whole laminated film even if it is 70 or more, the rigidity of the laminated film becomes insufficient and the following various problems occur. That is, blocking, winding wrinkles or breaks occur in the core portion of the long-length laminated film roll, shrinkage occurs during the vapor deposition process, or wrinkles occur in the core portion of the vapor deposition film roll that has undergone the vapor deposition process. To do. The vapor barrier property of the vapor deposition film itself or a laminate film of the vapor deposition film and a biaxially oriented polypropylene film or a polyester film heat-sealed or a bag produced by an automatic filling and packaging apparatus is significantly reduced.

There is no particular limitation on the melt flow rate (measured at 2.16 Kgf at 230 ° C.) of each crystalline propylene polymer used for each of the layers (A), (B) and (C), but the layers are laminated. When the film is produced by the T-die / chill-roll method, a range of 1 to 30 g / 10 min is preferable because a uniform thickness can be obtained, and more preferably 3 to 2
It is in the range of 0 g / min. When the laminated metal vapor deposition film of the present invention is used as a laminate film with a biaxially oriented polypropylene film or a polyester film, when metal vapor deposition is applied to the (A) layer surface and the (C) layer is used as a sealant layer, the (C) layer Is a polymer having a crystalline melting point (peak temperature of endothermic curve measured with a scanning differential calorimeter at a heating rate of 10 ° C./min, Tm) of 150 ° C. or less, for example, propylene / ethylene copolymer, propylene / It is preferable to use a crystalline propylene-based polymer such as an ethylene / butene copolymer or a copolymer mainly composed of propylene and another α-olefin because the laminate strength is large.

As a more preferred embodiment of the present invention, the crystalline propylene-based polymer of the layer (A) and the layer (B) of the above laminated film contains the following calcium, sodium, alumino,
0.01 to 1.00 parts by weight of each silicate is compounded. Sphericity: 0.99 to 0.85, specific surface area: 50 m ²
Hereinafter, loss on ignition: 10 wt% or less, average particle size: 1.0 to
6.0 μm Here, the sphericity (Fx) is the circumscribed circle radius (R1) and the inscribed radius (R2) of a single particle measured by an electron micrograph of powder.
The average of 100 particles of Fx calculated from
Average value . If the powder is a true sphere, the sphericity will be 1.0. (Fx) ² = (R1 × R2) / (R1) ^{2 If} a particle with a sphericity close to 1.0 is blended, the dynamic friction coefficient of the film Although the effect of lowering the film thickness can be obtained, the effect of preventing blocking between films and the blocking of vapor-deposited film cannot be obtained, and wrinkles cannot be prevented from occurring in the core portion of the raw film or vapor-deposited film. On the other hand, if the sphericity is less than 0.85, there is no blocking prevention effect, and there is no point in blending. The specific surface area is measured by the BET method. 50m specific surface area
If it is larger than ^{2, the} amount of oil absorption is large, which causes a decrease in the wetting tension of the vapor deposition surface and impairs the function as a vapor deposition film.

Ignition loss is determined by igniting at 850 ° C. for 1 hour. If the loss on ignition is greater than 10 wt%, it becomes a factor of lowering the wetting tension of the vapor deposition surface, impairing the function as a vapor deposition film. The average particle diameter is obtained from a cumulative distribution chart measured using a Coulter Counter (manufactured by Coulter Co., USA). If the average particle size is less than 1.0 μm, the blocking preventing effect is insufficient, and tearing is likely to occur when the film is rewound in the metal vapor deposition step. On the other hand, when the average particle size exceeds 6.0 μm, blocking does not occur, but the film surface becomes rough and the gloss of the vapor-deposited surface deteriorates, and a vapor-deposited film having a beautiful metallic gloss cannot be obtained, which is not preferable.
If the amount of the above calcium, sodium, alumino, silicate is less than 0.01 part by weight, the antiblocking effect is insufficient and the compounding is meaningless. It is not preferable because the gloss is lowered and the film-rolled film is easily scratched on the dressing surface, resulting in peeling of the dressing film → reducing gas barrier property.

Such calcium-sodium-alumino-silicate fine powder is obtained by ion-exchange treatment of a natural or synthetic zeolite with a divalent metal and then heat-treating it to obtain an amorphous substance. According to the X-ray diffraction method, Although it is completely amorphous and does not show a crystal structure, the primary particles are cubic or spherical with almost uniform size. The chemical composition of these fine particles is
Silicon oxide: 53-56 wt%, aluminum oxide: 2
5 to 28 wt%, calcium oxide: 8 to 11 wt%, sodium oxide: 4 to 8 wt%, loss on ignition: 4 wt% or less. The crystalline propylene-based polymer used in each of the layers (A), (B) and (C) may be added with various stabilizers and fillers usually used in crystalline polypropylene films without impairing the object of the present invention. It can be blended in a range.

As a method for producing a laminated film in which three layers (A) / (B) / (C) are laminated in this order, the obtained film has good thickness uniformity and is suitable for long winding. A T-die / chill roll method, in which three layers are laminated in a molten state by a known method such as a coextrusion multilayer die method or a feed block method, and rapidly cooled to 70 ° C. or less by a chill roll, is preferably used. A metal is vapor-deposited on the (A) layer surface of the coextruded laminated film thus obtained, but it is preferable to carry out a surface treatment for improving the adhesive force between the film and the metal vapor deposition film. Examples of such surface treatment include corona treatment, discharge treatment, flame treatment and acid treatment, but corona treatment is most preferable because it can be continuously and simultaneously performed during the production of the film and the degree of treatment can be arbitrarily adjusted. As a method of depositing a metal, a known method such as a vacuum deposition method of depositing a metal vapor evaporated by high frequency induction heating in a vacuum apparatus on a film surface, a sputtering deposition method, an ioprating method can be used. The metal to be vapor-deposited includes gold, silver, copper-nickel, chromium, germanium, silicon, aluminum, etc., but the three-layer film used in the present invention has a particularly excellent effect in a long roll film roll vapor-deposited with aluminum. . The thickness of the metal vapor deposition layer is generally about 10 to several tens of millimeters from the viewpoint of peeling resistance and economy. The laminated metal vapor deposition film of the present invention thus obtained can be used by itself as an excellent packaging material for automatic filling and packaging. Further, by laminating a biaxially stretched polypropylene film, polyester film, nylon film, Poval film, etc. on the metal vapor deposition surface of the laminated vapor deposition film of the present invention, the gas barrier property against oxygen and nitrogen even when processed by a high speed bag making machine. It does not deteriorate and can be preferably used as a packaging bag for oily snacks such as potato chips.

[0011]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples. The measurement and evaluation of physical properties were performed by the following methods. Melt flow rate (MFR): JIS K7210
(230 ° C.) Roundness: According to the method described above. Crystal melting point (Tm): 10 mg using a scanning differential calorimeter
The sample is heated at a temperature rising rate of 20 ° C./min, and the peak temperature of the endothermic curve accompanying the melting of the crystal is defined as Tm. Stereoregularity (P): Using 270-MHz FT-NMR, the signal detectability was improved by the integrated measurement of 27,000 times, and the isotactic pentad fraction was calculated. Vapor deposition workability: Using a long film roll with a width of 2 m and a length of 32,000 meters, inspect for film breakage in the streaking process and for wrinkles, and evaluate to the following 3 ranks . Only A rank is practically used. A: No tearing or wrinkling occurred. B: Wrinkles did not occur without breaking. C: Breakage and wrinkles occur.

Gas barrier property: A urethane adhesive is undercoated on the vapor deposition surface of a laminated vapor deposition film on which aluminum having a thickness of 30 mm is vapor-deposited, and a biaxially oriented polypropylene film having a thickness of 25 microns is laminated.
The obtained laminated film is applied to a high-speed pillow automatic bag making machine (FA-350E, manufactured by Totani Giken Co., Ltd.) to perform high-speed bag making at 120 bags per minute. The oxygen transmission rate (GTR1) of the laminated film before bag making and the oxygen transmission rate (GTR2) of the laminated film after bag making were measured by a gas transmission rate measuring instrument (Toyo Seiki Co., Ltd., M-C3), The change in oxygen permeability before and after bag making is represented by the ratio of the two. ΔGTR = GTR2 / GTR1 Dimensional stability: 100 cm long in the film forming direction (MD) and 10 cm perpendicular to this (TD) using a hot air circulating constant temperature bath at 120 ° C. and 140 ° C., respectively. Heat treatment for 10 minutes. The length of the sample piece before and after the heat treatment is measured with an accuracy of up to 0.5 mm, and the shrinkage rate (%) in the length direction due to the heat treatment is obtained.

Examples 1 to 5 and Comparative Examples 1 to 5 MFR is 6.0, but various crystalline propylene polymers (Tris (P) having different stereoregularity shown by (P) in Table 1 are shown. (2,4-di-t-butylphenyl) phosphite (0.15 wt% and hydrotalcite having an average particle size of 0.8 μm is contained in 0.05 wt%) is used for the layer (B), and (A) is used. The crystalline propylene homopolymer having an MFR of 6.0 (tris (2,4-di-t-butylphenyl) phosphite was 0.10 wt% in the layer and the average particle size was 0.1.
(Containing 0.05 wt% of 8 μm hydrotalcite), and the ethylene content of the (C) layer is 4.0 wt.
%, MFR of 8.0, and crystalline melting point (Tm) of 145 ° C. crystalline ethylene / propylene copolymer (tris (2,4-
0.15w of di-t-butylphenyl) phosphite
t% and 0.03 wt% of hydrotalcite having an average particle size of 0.8 μm), and the width is 2 m and the thickness is 2
A 5-layer 3-layer laminated film was formed. For film formation, a three-kind three-layer coextrusion T-die device and a chill roll with a 150 mesh satin surface finish were used, and the die temperature was 220 ° C and the chill roll temperature was 30 ° C. The thickness of each layer of (A), (B), and (C) is different as shown in Table 1.

In any of the examples, the surface of the layer (A) is subjected to corona discharge treatment at the same time as the film formation to adjust the wettability index of the treated surface to 45 dyn / cm, and each of them is wound into a roll shape of 32,000 meters. Then, a single-sided processed original film was obtained. Using a roll-up type vacuum vapor deposition device having a vacuum degree of 1 × 10 ⁻⁵ Torr, a 30 mμ thick aluminum vapor deposition was applied to the surface of the (A) layer of the raw film to obtain a single-side vapor deposition film. Then, the vapor-deposited surface of this single-sided vapor-deposited film is anchor-coated with a urethane adhesive to give a thickness of 27 μm.
The corona-treated surface of the polypropylene biaxially stretched film of was laminated on the above anchor-coated surface and dry-laminated. The obtained laminated film was subjected to a high-speed bag-making machine to make a bag. Table 1 shows the physical property values of the raw film, the vapor-deposited film, the laminated film, and the film after bag making obtained in each of the above steps.

[0015]

[Table 1]

As is clear from the data shown in Table 1, all physical properties of Examples 1 to 5 satisfying the constituent requirements of the present invention are superior to those of Comparative Example. In particular, the (P) corresponding to the prior art is 0.950, or ΔGTR is smaller than that of the vapor-deposited film of Comparative Example 1 in which a normal crystalline polypropylene is used for the (B) layer, and workability as a packaging material. ,
It can be seen that the production efficiency is significantly improved.

Examples 6 and 7 Example 1 was reproduced. However, in Example 6,
In place of the crystalline propylene homopolymer for the (A) layer, (C)
The same crystalline ethylene / propylene copolymer as that of the layer was used, and in Example 7, the same (P) as in the layer (B) was 0.97 instead of the crystalline propylene homopolymer in the layer (A).
Using the crystalline propylene-based polymer of 5
It was a coextruded laminated film of layers. The physical properties of the raw film, the vapor deposition film, the laminated film, and the film after bag-making obtained in each process showed almost the same excellent properties as in Example 1.

Examples 8 to 10 and Comparative Examples 5 to 10 Crystalline propylene homopolymer having MFR of 8.0 (antioxidant: Irganox 1010 0.20 wt, manufactured by Ciba-Geigy).
%) With various anti-blocking agents shown in Table 2
Various master batches containing wt% were prepared. The crystalline propylene homopolymer for the (A) layer and the crystalline ethylene / propylene copolymer for the (C) layer used in Example 1 were blended with the above master batch in a predetermined amount shown in Table 2, The crystalline propylene-based polymer having the same (P) of 0.975 as in Example 1 was used for the (A) layer and the (C) layer, respectively, and the (B) layer was used for the (A), (B), and (C). A three-kind three-layer raw film having a thickness of each layer of 6: 18: 6 μm (total of 30 μm) was formed, and the physical properties were measured by vapor deposition, laminating and bag making in the same manner as in Example 1 ( Examples 8-1
0). For the (A) layer and the (C) layer, a polymer prepared by blending the above masterbatch is used, and for the (B) layer in Comparative Example 1, (P) is a crystalline propylene polymer of 0.950 ( Film formation, vapor deposition, and deposition were performed in the same manner as in Example 1 except that the layer B) was used.
Laminated and bag-formed, and measured for physical properties (Comparative Examples 5 to 5)
10). Table 2 shows the laminated film composition and the results of physical property evaluation.

[0019]

[Table 2]

As is clear from the data shown in Table 2, all the physical properties of Examples 8 to 10 satisfying the constitutional requirements of the present invention are superior to those of the comparative examples. The comparative example corresponding to the prior art is unfavorable as a packaging material due to winding wrinkles and tears, and in particular, those having a poor gas barrier property are lacking in practicality.

[0021]

EFFECTS OF THE INVENTION The laminated metal vapor deposition film of the present invention has excellent dimensional stability in the original film and has very few wrinkles and tears in the film forming / deposition process, and thus has excellent work efficiency and productivity, The film also has a good gas barrier property that can withstand high-speed bag making, and can be used for a wide range of purposes as a material for packaging and decoration.

Claims (4)

[Claims] 1. A laminated metal vapor deposition film in which three layers of (A) / (B) / (C) are vapor-deposited with a metal on one surface of a laminated film laminated in this order, and the layers (A) and (C) are provided. The layer is a crystalline propylene-based polymer or a crystalline propylene-based copolymer, and the layer (B) is a highly stereoregular crystalline propylene-based polymer having a (P) of 0.970 or more. Laminated metal vapor deposition film. 2. The laminated metal vapor deposition film according to claim 1, wherein the thickness of the layer (B) is 10% or more of the thickness of the laminated film. 3. A polymer 10 used in the (A) layer and the (C) layer.
Calcium-sodium-alumino-silicate 0.01 with a sphericity of 0.99 to 0.85, a specific surface area of 50 m ² / g or less, and an ignition loss of 10 wt% or less, relative to 0 parts by weight.
The amount of ˜1.00 parts by weight is added.
Laminated metal vapor deposition film. 4. The laminated metal vapor deposition film according to claim 1, wherein the laminated film is a three-layer coextruded film obtained by a T-die / chill-roll cooling method.