JPH02286329A - Metal vapor-deposited laminated film - Google Patents

Abstract

PURPOSE:To decrease the price of a base material and to attempt to improve impact resistance, strength of a vapor-deposited metal film, low temp. resistance, low temp. seal properties and luster by constituting three-layered laminations wherein a linear low density ethylene-alpha-olefin copolymer and a crystalline polypropylene are incorporated at specified densities and mixing ratios. CONSTITUTION:In a composite film constituted by laminating below described A, B and C layers in the order of A, B and C by means of a coextrusion method, the layer A is a layer wherein 100pts.wt. linear low density ethylene-alpha- olefin copolymer with a density of 0.925 or larger is mixed with 5-100pts.wt. crystalline polypropylene; the layer B is a layer consisting of a linear low density ethylene-alpha-olefin copolymer with a density of 0.925 or larger and the layer C is a layer consisting of a linear low density ethylene-alpha-olefin copolymer with a density or 0.935 or smaller. A metal is vapor-deposited on the layer A of the coextruded laminated film.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a metallized laminate film. More specifically, it can be applied to general packaging materials, various industrial materials, etc., can be heat-sealed at low temperatures, and has excellent mechanical properties, heat resistance,
The present invention relates to a metal-deposited laminated film having low temperature resistance, blocking resistance, gas barrier properties, surface gloss, etc.

(Prior art) In recent years, metal-deposited films, which are made by depositing metal on plastic films under vacuum, have been developed, and their excellent decorative properties and
Utilizing its gas barrier and light blocking properties, it has been widely used in gold and silver materials, building materials, and packaging materials, and aluminum vapor-deposited films in particular have come to be used in large quantities mainly for packaging. Ta.

Conventionally, polyester, nylon, polypropylene, etc. have been used as base materials on which metals are vacuum-deposited, but
Polyester and nylon have excellent properties but are expensive, while polypropylene is low in price, has good gloss on the metal-deposited surface, and is heat resistant, but it has impact resistance, low-temperature resistance, low-temperature sealability, metal-deposition strength, etc. is not sufficient.

On the other hand, when conventionally known high-pressure low-density polyethylene is used as a base material, it is inexpensive and has excellent impact resistance, low-temperature resistance, and low-temperature sealing properties, but it has poor heat resistance and metal-deposited surfaces. The gloss, mechanical strength, anti-blocking properties, etc. were poor and unsatisfactory.

In addition, recently developed low-pressure linear low-density ethylene -α-
When the olefin copolymer is used alone as a base material, it has better impact resistance, tear strength, tensile strength, heat seal strength, etc., but heat resistance.

The gloss, anti-blocking properties, etc. of the metal-deposited surface were not improved and were insufficient.

[Problems to be Solved by the Invention] In view of the above circumstances, the present inventors have developed a base material that is inexpensive, has impact resistance, metal film deposition strength, low temperature resistance, heat resistance, low temperature sealability, and a metal deposition surface. The object of the present invention is to provide a metal-deposited laminated film with excellent gloss etc.

More specifically, when the specific linear low-density ethylene-〇-olefin copolymer used in the present invention is used alone as a base material for a metal-deposited laminated film, conventional high-pressure low-density polyethylene, Although there are improvements over using a linear low-density ethylene-α-olefin copolymer as a base material, there are still problems with heat resistance, loss of aesthetic appearance due to distortion of the metal vapor deposited layer surface due to heat sieving, and anti-blocking properties. The remaining issues are to be resolved.

[Means for Solving the Problems] The present invention solves the problems when a metal-deposited laminated film is made using a specific linear low-density ethylene-α-olefin copolymer alone, and solves the problem by using crystalline polypropylene. The present invention relates to a metal-deposited laminated film that solves the problem by adding .

That is, the present invention provides the following (A) layer, (B) layer, and (C) layer by coextrusion method.
In a composite film in which the layers (A), (B), and (C) are laminated, the (A) layer has a density of 0.92.
5 to 1 of crystalline polypropylene per 100 parts by weight of a linear low density ethylene-α-olefin copolymer of 5 or more.
The layer (B) is a layer consisting of a linear low density ethylene-α-olefin copolymer having a density of 0.925 or more, and the (C) layer is a layer in which parts by weight of OO are mixed.
This is a metal vapor-deposited laminated film formed by vapor-depositing a metal on layer A of a coextrusion laminated film, characterized in that the layer is made of a linear low-density ethylene-〇-olefin copolymer having a density of 0.935 or less.

The density used in the (A) layer, (B) layer and (C) layer of the present invention is 0.930 g/cm' or more, and the MFR is 1.
．． A linear low-density ethylene-〇-olefin copolymer with a hexane extractable content of 0 to 7.0% by weight or less is prepared using a known method, that is, a transition metal compound (such as titanium, vanadium, etc.) as a main catalyst. compound), an organometallic compound (e.g. organoaluminium) as a promoter, a Ziegler catalyst consisting of a carrier (e.g. oxides of silicon, titanium, magnesium, etc.), a chromium-based catalyst, etc., in the presence of ethylene and α-olefin. Obtained by polymerization under medium or low pressure.

α-olefins are propylene, butene-1, hexene-
1, octene-1, decene-1, etc. are preferred.

Polymerization can be carried out in various ways, such as slurry polymerization, gas phase polymerization, and high temperature solution polymerization.

The density of this linear low density polyethylene is 0.925 g
If it is less than /am3, the luster of the metallized film becomes a white crucible, the metallic luster is lost, and the amount of low molecular weight substances increases, making the deposition strength higher, which is undesirable.

If the melt index is less than 1.0, the productivity and processability will be poor (undesirable) when extruding using a T-die. If the melt index exceeds 7.0, the processability will be good, but the film will be Mechanical strength decreases, which is undesirable.

Further, the hexene extractable content of this linear low density ethylene-α-olefin copolymer is 1,0% by weight or less, preferably 0.5 or less. If it exceeds 1.0% by weight, the adhesion between the layer (A) and the metal vapor deposition becomes insufficient, which is not desirable.

In the present invention, the crystalline polypropylene used for layer (A) is usually a propylene homopolymer obtained by polymerizing propylene using a known α-olefin stereoregular catalyst such as a Ziegler-Natsuta catalyst, or a propylene-based polymer. As a component, it is a crystalline random copolymer of propylene and other α-olefins, such as ethylene, butene-1,4-methylpentene-1, hexene-1, heptene-1, octene-1, etc. Specifically, crystalline propylene homopolymer, crystalline ethylene-propylene random copolymer, crystalline propylene-butene-1 random copolymer, crystalline ethylene-propylene-butene-1 ternary random copolymer, etc. I can give it to you.

Further, in the present invention, the crystalline melting point of the crystalline polypropylene used for layer (A) is preferably higher than 140°C, and if the crystalline melting point is 140°C or lower, the resulting metal-deposited laminated film will have wrinkles. Curling bumps are likely to occur.

In the present invention, the resin composition constituting layer (A) contains 5 to 100 parts by weight of crystalline polypropylene mixed with 100 parts by weight of a linear low-density ethylene-α-olefin copolymer.

If the amount of crystalline polypropylene exceeds 100 parts by weight, impact resistance, low temperature resistance, low temperature heat sealability, etc. will be insufficient, which is not desirable.

When the crystalline polypropylene content is less than 5% by weight, heat resistance,
This is undesirable because it results in insufficient blocking resistance and gloss of the metal-deposited surface.

It is desirable to add very specific antioxidants and inorganic fillers to the polymer constituting each layer of the metallized film of the present invention. In other words, fatty acids and The derivatives migrate over time to the surface of the laminated film and float to the surface of the film on the side where the metal is deposited, resulting in a decrease in the metal deposition power, or Substances floating on the back side of the film layer adhere to the surface of the metal evaporated film when the metal IT film is rolled, reducing the wettability index of the metal evaporation film surface, and as a result, worsening the printability of the metal evaporation film surface. This is not preferable because it also causes problems such as a decrease in adhesive strength when laminating other films.

Therefore, as a preferable additive to be added to the polymer, copolymer, random copolymer, etc. used for the (A) layer, (B) layer, and (C) layer of the present invention, a heat stabilizer having a molecular weight of 500 or more is preferable. and polymer additives that do not contain antioxidants, inorganic fillers such as silica, zeolite, calcium carbonate, and additives such as the above-mentioned fatty acids or derivatives thereof.

The proportion of the above-mentioned additives to be added to the polymer, copolymer, random copolymer, etc. used for the (A) layer, (B) layer, and (C) layer is phenolic or phosphorous with a molecular weight of 500 or more. The heat stabilizers and antioxidants in the system are 0. O1~0
．． 3% by weight, 1 of inorganic fillers such as silica and zeolite
Species or more 0. It is desirable to add 1 to 0.5% by weight of O.

By using a polymer, copolymer, random copolymer, etc. in such an addition ratio for the (A) layer, (B) layer, (C) layer, etc., the metal vapor deposited laminate film of the present invention can be obtained.

The (A) layer, (B) layer, and (C) layer of the present invention are (A)/(
It is laminated in three layers with the configuration of B)/(C). This method of laminating three layers requires one or two units for the (B) layer and (C) layer, and (A
) For the layers, two or three extruders are used in a known method such as the melt extrusion feed block method or the coextrusion multilayer die method, and the layers are laminated in a molten state in a part of the adapter or inside the gou. It is obtained by a coextrusion lamination method in which the film is formed by cooling with electricity, cooling water, chill rolls, etc., but T-die and
Production by the chill roll method is particularly desirable in terms of film gloss, anti-blocking properties, and less uneven thickness.

The structure of the laminated film is (A) / (B) / (C) /
Those utilizing the technical concept of the present invention such as (B)/(C), (A)/(B)+(C), etc. fall within the scope of the present invention. ((B) + (C) means a composition consisting of (B) and (C).) Other lamination methods, such as extrusion lamination method in which one film is melt-extruded onto the other, adhesive In the extrusion lamination method, etc., in which lamination is performed by laminating and bonding using a compound, it is necessary to laminate on both sides, which is disadvantageous in terms of cost, and the (A) layer,
Both layers (B) and (C) are individually thin films with poor slip properties, and are flexible and stretchable, so they wrinkle during lamination, making it difficult to obtain uniform control.

Furthermore, the interlayer adhesion between each layer is poor, which is undesirable in terms of cost and performance.

The (A) layer, (B) layer, and (C) layer of the present invention are (A)/(
It is necessary to stack them in the order of B)/(C).

Regarding the thickness ratio of each layer in the structure (A)/(B)/(C) of the present invention, the thickness of the (B) layer is preferably 20 to 80% of the total thickness, and particularly preferably 50 to 70%.

(The thickness ratio of the layer (A) and (C) is preferably 10 to 40% of the total, and 15 to 30% of the total thickness. % is particularly preferred.

(A) If the thickness of the layer is less than 10% of the whole, the heat resistance will be poor and the quality of the metal vapor deposited film will be large during heat sealing.
% or more is not desirable because impact resistance, low temperature resistance, tear resistance, etc. are poor, and economical efficiency is also poor.

Moreover, if the (C) layer accounts for less than 10% of the whole, the low-temperature heat sealability is poor, and if it accounts for more than 40%, the mechanical strength deteriorates, which is not desirable.

The film thickness of the laminated film composed of (A)/(B)/(c) of the present invention is usually desirably 20 to 1OOμ.
~60μ is particularly desirable.

After surface-treating the surface of the (A) layer of the thus obtained laminated film consisting of three layers (A), (B), and (C), a metal is deposited under vacuum to produce the desired metal-deposited film of the present invention. is obtained.

At this time, as a surface treatment method, any treatment method such as acid treatment, flame treatment, plasma treatment, or corona discharge treatment may be used, but if the laminated film can be treated continuously and the laminated film is Corona discharge treatment, which can be easily treated, is preferred because it is simple.

In addition, the degree of surface treatment is such that the wettability index measured by the method of J I 5K6768 is 35 dynes/cm or more,
In particular, it is preferable to process it so that it becomes 42 to 48 dynes/cm.

In addition, in order to strengthen the adhesion between the film and the metal vapor-deposited film, it is possible to anchor-coat the surface-treated surface of the film with an adhesive such as polyester, polyurethane, or epoxy resin, and then vapor-deposit the metal. good.

Any known method such as a vacuum evaporation method, a sputtering method, or an ion beam method can be used to deposit the metal. The pressure inside the device is reduced to about 10-3 torr using an oil pump and a diffusion pump, and a container containing a desired metal such as aluminum, nickel, gold, or silver or a filament with a desired metal attached is heated. A common method is to melt and evaporate the metal, continuously or intermittently deposit the metal on the surface of layer (A) of the laminated film, and then wind the film. The metal used has workability,
Aluminum is preferable from the economic point of view, and the thickness of the vapor deposited layer is desirably about several tens to several hundred angstroms (thickness) from the point of view of adhesiveness of the vapor deposited film.

The metallized film of the present invention thus obtained is
Although it is useful on its own, it has been developed to take advantage of the excellent adhesion properties of metal-deposited surfaces to protect the metal-deposited surface by preventing scratches, and to further improve its functionality as a packaging material. After anchor-coating the vapor-deposited surface with an adhesive, a film or sheet of thermoplastic polyester resin, nylon resin, crystalline polypropylene resin, etc. is laminated to increase rigidity and strength while maintaining the characteristics of the metal-deposited film of the present invention. , a laminate with significantly improved gas barrier properties can be obtained.

It is also possible to print on the metal vapor-deposited surface before laminating the unstretched film or sheet described above on the metal vapor-deposited surface to obtain a laminate with improved decorativeness and product image. As a method for printing and laminating on the metal vapor-deposited surface, commonly used known methods can be used.

In addition, it is desirable to apply the above-mentioned surface treatment to the laminated surface of the above-mentioned film or sheet used for lamination in order to improve adhesion.Also, two or more types of films or sheets to be laminated are stacked on the metal-deposited surface. I don't mind if you do.

(Operations and Effects of the Invention) The metal-deposited laminate film of the present invention has a specific linear low-density ethylene-olefin copolymer as the main component in each layer, so it is inexpensive, and has excellent impact resistance and resistance. It has excellent low temperature properties, tear strength, low temperature heat sealability, metal vapor deposition strength, etc., and the (A) layer is made of the linear low density ethylene-α-
Since crystalline polypropylene is added to the olefin copolymer, in addition to the above advantages, it has excellent heat resistance, blocking resistance, and gloss on the metal-deposited surface, and the (B) layer is made of the linear low-density ethylene- Since the α-olefin copolymer layer occupies the main part of the total film thickness, this layer mainly provides mechanical strength.Layer C) has a lower melting point than layer (A), so
When heat-sealing, heat-sealing can be performed at a relatively low temperature and does not adversely affect layer (A).

Therefore, the metal-deposited laminated film of the present invention has superior impact resistance, blocking resistance, surface metallic luster, heat resistance, and anti-blocking properties compared to conventional polyethylene-based vapor-deposited laminated films, and is superior to polypropylene-based vapor-deposited films. In comparison, it is superior in impact resistance, low temperature properties, tear strength, metal vapor deposition strength, etc.

This metal-deposited laminated film is useful for decoration, packaging, industrial materials, etc.

(Examples) Hereinafter, the present invention will be specifically explained using Examples and Comparative Examples. The following method was used to measure each characteristic of the evaluation items used in the present invention.

The vapor-deposited film side of the L1 plate-deposited film and the Surlyn film (Ionomer #50 manufactured by Tamabori) were sealed at a temperature of 120°C, a sealing pressure of 2.0 kg/Cff1'', and a sealing time of 1.
Heat seal the width 10mrnX l 5mrrx under the condition of 0 seconds, and 180 mm at a tensile speed of 300mm/min.
The peel strength was measured using a tensile tester.

C unit; g/15rrim) 1” 11 Aeon Shidanyu 8. It has a metallic luster.

O Excellent metallic luster.

Blocking method A film roll obtained by continuously winding up a certain length of film is observed with the naked eye, and if the surface is flat and there are no wrinkles or thickening (rolling bumps), it is marked as ○.
(Good rolling appearance), and those with wrinkles or thickening were evaluated as × (Poor rolling appearance).

1 Heat seal the laminate film and observe the degree of peeling and white discoloration on the sealed surface.

X Partial peeling and white discoloration.

△ There is no peeling, but there is some white discoloration.

○ No peeling or white discoloration.

1 mile violet Measured according to ASTM-D 1709A.

Hiroakiri Wataru Measured according to JIS P8116.

20cmX made from the metallized laminated film of the present invention
Fill a 25 cm bag with 1 kg of sugar, heat seal it at 200°C, and then cure it at -10°C for 10 hours.
10 bags were dropped vertically from a height of m, and the bags were observed for breakage.

×-Broken bag 5 or more △-Broken bag l~4 0 - No broken bag MFR melt flow rate According to JIS K6760-1976.

Crystalline polypropylene was tested under test conditions 14 (230°C, 2.
16 kg), and the linear low-density ethylene-〇-olefin copolymer was measured under test conditions 4 (190°C, 2.16 kg).

Place 300cc of hexane in a glass container and heat to 50℃.
3 g of a film sample with a thickness of 40 μm was cut into tanzak shapes and placed therein, and the mixture was left as it was for 2 hours.

Thereafter, the film sample was taken out, its weight was measured, and the hexane extractable amount was calculated using the following formula.

slow speed JIS According to K-6760.

[Example 1] Gas-phase process linear ethylene-butene-1 copolymer (density 0.
930, MFR=2.0. 100 parts by weight of hexane extract (0.93% by weight) and a crystalline propylene polymer (density 0.93% by weight).
900, M F R2.0, hexane extract 0.20%
) 5 parts by weight (0.15% by weight of tetrakis[methylene(3,5-jetershower-butyl-4-hydroxyphenylpropionate)methane and (A) containing 1% by weight of silica O with an average particle size of lμ as an antiblocking agent.
Prepared for layer use.

Gas phase method linear ethylene-hexene-1 copolymer (density 0
．． 940. MFR4.5, hexane extract 0.47%,
(A) contains antioxidant o used in layer 12% by weight) 1
00 parts by weight was prepared for layer (B).

In addition, a gas phase method linear ethylene-butene-1 copolymer (density 0.933, M F R5, O, hexane extractable content 0.
For the (C) layer, 100 parts by weight (including 12% by weight of the antioxidant o used in the (A) layer) was prepared for the (C) layer.

Next, using a three-layer extruder with a diameter of 90 mm for layer (B) and a diameter of 65 mm for layers (A) and (C), and a three-layer T die connected to this, layer (B) was Combine layer (A) and layer (C) to the core layer so that they form the surface layer (A).
) / (B) / (C) = 1 + 3: 1 composition, melt coextruded, rapidly cooled in an air chamber and a metal cooling roll with a surface temperature of 20 ° C, formed into a film, and immediately applied to the (A) layer surface of the film. After corona discharge treatment was performed while adjusting the wettability index to 42 dyn/c+n, the film was wound up to obtain a three-layer film treated on one side. Next, this film was cut to a width of 60 cm using a slitter, and then set in a vacuum evaporation device and subjected to corona discharge treatment while continuously feeding the film in a vacuum maintained at 3 X 10-' torr or less ( A) Aluminum vapor deposition is performed on the layer surface and the film is rolled up, so that the thickness of the vapor deposited film is 0.04 μm (400 μm).
A single-sided metal-deposited three-layer laminated film was obtained which was wound into a roll having a length of 1,000 m. The metal film deposition strength, brightness of the metal deposited film, blocking resistance, heat resistance, impact strength, tear strength, and low temperature properties of this metal vapor deposited three-layer laminate film were measured and evaluated, and the results were satisfactory.

[Examples 2 to 5] Layer (A) and (B) used in Example 1! , Example 1 was prepared by changing the type of linear ethylene-α-olefin copolymer in layer (C) as shown in Table 1, and changing the amount of crystalline polypropylene used as shown in Table 1. A metal-deposited three-layer laminate film was obtained in a similar manner.

For each, the same evaluation as in Example 1 was performed, and it was confirmed that sufficient effects were observed and the invention was realized.

[Comparative Example 1] In Example 3, the amount of crystalline polypropylene used in the layer (A) was 0, so the blocking resistance and heat resistance were insufficient, and this does not constitute the invention.

[Comparative Example 2] In Example 3, only 100 parts by weight of crystalline polypropylene was used in place of the ethylene-hexene-1 copolymer used in layer (A), so the impact strength, tear strength, and low-temperature properties were insufficient. Yes, it does not constitute an invention.

Claims (7)

[Claims] (1) In a composite film in which the following layers (A), (B), and (C) are laminated in the order of (A), (B), and (C) by a coextrusion method, the (A) layer is A layer in which 5 to 100 parts by weight of crystalline polypropylene is mixed with 100 parts by weight of a linear low-density ethylene-α-olefin copolymer having a density of 0.925 or more, layer (B) has a density of 0.925 or more. The layer (C) is a layer made of a linear low density ethylene-α-olefin copolymer having a density of 0.935 or less. A metal vapor-deposited laminate film formed by vapor-depositing a metal on the A layer of a coextrusion laminate film. (2) The linear low density ethylene-α-olefin copolymer used for layer (A) has a density of 0.930 or more and an MFR of 1.0.
7.0, and a hexane extractable content of 1.0% by weight or less, the metal vapor deposited laminate film according to claim 1. (3) The linear low density ethylene-α-olefin copolymer used in layer (B) has a density of 0.925 or more and an MFR of 1 to 7.
Claim (1) wherein the hexane extractable content is 1.0% by weight or less.
Or the metal-deposited laminated film according to claim (2). (4) Layer (A), layer (B) and layer (C) according to claim (1)
) A coextruded laminated film characterized in that the layers are composed of five layers: (A) / (B) / (C) / (B) / (C).
A metal-deposited laminated film made by depositing metal on layers. (5) The metal vapor-deposited laminated film according to claim (1) or (4), wherein the linear low-density ethylene-α-olefin copolymer used in each layer is the same. Vapor-deposited laminated film. (6) In the metallized laminate film according to claim (1) or (4), the linear low-density ethylene-α-olefin copolymer used in the layer (B) and layer (C) are the same. A metal vapor-deposited laminated film characterized by the following. (7) The method for producing a metal-deposited laminated film according to any one of claims (1) to (6), which is produced by a T-die chill roll cooling method.