JPH08104977A - Metal vapor-deposited polypropylene film - Google Patents

Abstract

PURPOSE: To obtain a metal vapor-deposited PP film having a beautiful metallic luster and excellent in blocking resistance, slipping property and scratch resistance without deteriorating the vapor-deposited film adhesion, vapor-deposited face printability and adhesion to other films. CONSTITUTION: A metal is vapor-deposited on a film obtained by using a composition formed by mixing 0.01-1 pts.wt. of the globular fine particle of magnesium silicate having 0.5-7μm average diameter, contg. <=40wt.% magnesium oxide and having >=0.7 sphericity (Fx) >=500m<2> /g BET specific surface area and <=150ml/100g oil absorption in 100 pts.wt. of a crystalline propylene copolymer to obtain a metal vapor-deposited PP film. Otherwise, the metal vapor-deposited PP film with the crystalline propylene copolymer contg. >=80wt.% propylene and having <=150 deg.C crystal m.p. is formed as a crystalline propylene-α-olefin copolymer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to metallized films or sheets. More specifically, the adhesiveness of the vapor deposition film, the printability on the vapor deposition surface, the laminate suitability, and
The present invention relates to a metal vapor-deposited polypropylene film or sheet having excellent blocking resistance, slip resistance, and scratch resistance (hereinafter, simply referred to as a metal vapor deposition film).

[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 utilized for their excellent decorative properties, gas barrier properties, light shielding properties, and the like, and are used for gold and silver threads, building materials and packaging films. Widely used for etc. In particular, aluminum vapor-deposited films obtained by vapor-depositing aluminum are widely used mainly for packaging applications.

However, it has been commercially available by depositing a metal on a polypropylene film using a polypropylene resin such as a homopolymer of propylene or a copolymer of propylene mainly containing propylene and ethylene or α-olefin. The vapor deposition film has a weak adhesion between the base film and the metal vapor deposition film, and when the vapor deposition metal is aluminum, the printability and the adhesiveness to the vapor deposition surface are remarkably reduced, and printing or lamination is required. It could not be used for various purposes, which was a major obstacle to application development. The cause of this is that, as described in JP-A-59-25829, neutralizing agents, slip agents, antioxidants, etc., which are usually added to polypropylene resins, migrate to the surface of the film or the film is laminated. When the additives transferred to the film surface is sometimes transferred to other film surfaces, of which fatty acid derivatives, in particular calcium stearate used as a neutralizing agent for the acidic component of the catalyst residue in the polymer,
Higher fatty acids such as sodium stearate, fatty acid derivatives such as higher fatty acid amides such as oleic acid amide, stearic acid amide, erucic acid amide, and ethylene bisstearamide, which are commonly used as a slip agent for a film, are 0.
Wetting index of vapor deposition surface is 33 even with a small amount of addition of around 01% by weight.
dyne / cm or less, printing on the vapor deposition surface or adhesion of other films becomes impossible, but these additives are conventionally used as essential additives for polypropylene films, Polypron films without these additions cause many problems during film formation or during post-processing of the film.

For example, when the above-mentioned slip agent is not added, the slipperiness and blocking resistance of the obtained film are extremely lowered, the wound film is wrinkled, and the film roll is locally enlarged. Rolling humps will occur and productivity will be significantly reduced. Especially propylene-α
-When an olefin random copolymer is used, the resulting film has low rigidity and high tackiness, and thus these phenomena are prominent, which not only lowers the productivity and yield of the film but also causes wrinkles and lumps. Even if only a portion without a metal is selected and metal vapor deposition is performed, wrinkles and lumps are generated in the film winding process after vapor deposition, which further deteriorates the productivity of the vapor deposited film. This phenomenon is more remarkable as the melting point of the propylene-α-olefin copolymer is lower, and maleic anhydride is added to polypropylene as disclosed in JP-A-50-61469 and JP-A-55-52338. The same applies to a film obtained by blending a grafted polypropylene obtained by graft-polymerizing the above with polypropylene. From this point of view, the metallized polypropylene having excellent impact resistance and heat sealability as well as excellent printability and adhesiveness on the vapor deposition surface is demanded.

Many proposals have been made to solve these problems. For example, Japanese Examined Patent Publication (Kokoku) No. 61-16617 proposes a metal vapor-deposited polypropylene film obtained by vapor-depositing a metal on a film surface obtained by using a composition obtained by adding zeolite powder to polypropylene. However, the metal vapor deposition film described in the publication is excellent in vapor deposition film adhesiveness, and is a vapor deposition film with less decrease in metal surface wetting index, but the slip property of the obtained vapor deposition film is extremely poor, and the addition of zeolite is also included. As the amount increases, the surface of the film becomes rough, and it becomes impossible to obtain a film having a beautiful metallic luster, and fisheyes and pinholes are generated due to the zeolite used, and
There are drawbacks such as scratches caused by rubbing between the films.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have solved the above-mentioned drawbacks by depositing a metal film, that is, having a beautiful metallic luster, adhesiveness of a vapor deposition film, printability of a vapor deposition surface, and other films. Blocking resistance, without impairing adhesion
We have conducted intensive studies to obtain a metal-deposited film with excellent slip and scratch resistance. As a result, a metal vapor-deposited film in which a metal was vapor-deposited on a polypropylene film obtained by using a composition in which a specific amount of spherical fine particles of specific magnesium silicate was added to a crystalline propylene copolymer solved the above-mentioned drawbacks. I found that it was a vapor deposition film,
The present invention has been completed based on this finding. As is clear from the above description, the object of the present invention is to have a beautiful metallic luster, to prevent vapor deposition film adhesion, printability of vapor deposition surface, and adhesion to other films without impairing blocking resistance and slippage. To provide a metallized polypropylene film having excellent properties and scratch resistance.

[0007]

The present invention has the following constitution. (1) 100 parts by weight of the crystalline propylene copolymer has an average particle size of 0.5 to 7 μm and a magnesium oxide content of 40.
% By weight, sphericity (Fx) of 0.7 or more, specific surface area by BET method of 500 m ² / g or more, and oil absorption of 15
A metal-deposited polypropylene film in which a metal is vapor-deposited on a film obtained by using a composition containing 0.01 to 1 part by weight of spherical fine particles of magnesium silicate of 0 ml / 100 g or less. (2) The crystalline propylene copolymer contains 80% by weight or more of a propylene component and has a crystalline melting point of 150 ° C. or less, which is a crystalline propylene-α-olefin copolymer.
The metal evaporated polypropylene film according to the item.

The present invention relates to a crystalline propylene copolymer 10
0 parts by weight, preferably 100 parts by weight of a crystalline propylene-α-olefin copolymer having a propylene component copolymerization ratio of 80% by weight or more and a crystal melting point of 150 ° C. or less, and an average particle size of 0.5 to 7 μm. , Magnesium oxide content is 40
% By weight, sphericity (FX) of 0.7 or more, non-surface area by BET method of 500 m ² / g or more, and oil absorption of 1
A metal-deposited polypropylene film in which a metal is vapor-deposited on the surface of a film obtained by using a composition containing 0.01 to 1 part by weight of spherical fine particles of magnesium silicate of 50 ml / 100 g or less.

The crystalline propylene copolymer used in the present invention contains propylene as a main component, and the propylene and α-
A crystalline propylene-α-olefin copolymer with an olefin, wherein the α-olefin component is an α-olefin having 4 or more carbon atoms such as ethylene or butene-1, hexene, and 1 or 2 or more thereof. It is a binary or more copolymer with propylene. These crystalline propylene-α-olefin copolymers are crystalline propylene having a crystalline melting point (hereinafter sometimes referred to as Tm) of 150 ° C. or less from the viewpoint of vapor deposited film adhesion, impact resistance and heat sealability. -Α
-Olefin copolymers are preferred. Where the crystal melting point
(Tm) means the peak temperature of the endothermic curve accompanying the melting of crystals obtained by heating a 10 mg sample at a rate of 10 ° C./min in a nitrogen atmosphere using a scanning differential calorimeter.

In the case of a crystalline copolymer containing propylene as a main component, Tm decreases as the content of ethylene or α-olefin as a comonomer component increases. For example, in the case of a crystalline ethylene-propylene random copolymer, the Tm becomes 150 ° C. or lower when the ethylene content exceeds about 2.5% by weight, although it varies slightly depending on the randomness of the copolymer. A polymer having a plurality of Tm's can be obtained by carrying out the copolymerization in two or more stages of multistage polymerization under different polymerization conditions. In this case, the main peak is 150
Those below ℃ are desirable.

The spherical fine particles of magnesium silicate used in the present invention have a magnesium oxide content of 40% by weight or less,
The sphericity (FX) is 0.7 or more, the specific surface area by BET method is 500 m ² / g or more, and the oil absorption is 150 ml / 1.
The composition formula is as follows:
₂ ) x · (MgO) y · (Na ₂ O) z · (H ₂ O) n, where the component ratio of each component is x = 30 to 99% by weight y = 0.5 to 40% by weight z = 0 to 2% by weight, n = 1 to 25% by weight, and x + y + z + n = 100% by weight. Such magnesium silicate includes silicon dioxide (SiO ₂ ) and magnesium hydroxide (Mg (O
H) ₂ ) and a commercially available product may be used. Examples of such commercially available products include Mizupearl Chemical Co., Ltd.'s trade name Mispearl M, and those having an average particle size of 0.5 to 7 μm are preferable. If the average particle size exceeds 7 μ, the transparency of the obtained film is deteriorated, and if the average particle size is less than 0.5 μ, the slip property and blocking resistance of the film at the time of winding are deteriorated.

The compounding amount of the spherical fine particles of magnesium silicate is 0.01 to 1.0 part by weight based on 100 parts by weight of the crystalline propylene copolymer. When the content is less than 0.01 part by weight, the effect of improving the slipperiness and blocking resistance of the resulting film is insufficient, and when it exceeds 1 part by weight, fish eyes are generated and transparency is deteriorated, which is not preferable.
A compounding amount in the range of 0.03 to 0.3 part by weight is particularly preferable. The magnesium silicate spherical fine particles used in the present invention have a magnesium oxide content of 40% by weight or less and a sphericity (FX) of 0.7 or more. When the content of magnesium oxide exceeds 40% by weight, the scratch resistance of the metal vapor deposition film obtained is deteriorated, and when the sphericity (FX) is less than 0.7, the slipperiness of the film obtained is deteriorated. To do. The magnesium silicate spherical fine particles have a BET specific surface area of 500 m ² / g or more and an oil absorption of 150 ml / 100 g or less. The specific surface area is less than 500 m ² / g and the oil absorption of 150 ml / g.
Use of more than 100 g is not preferable because the slip property and blocking resistance of the obtained metal-deposited polypropylene film are deteriorated.

The average particle size, specific surface area and oil absorption of the spherical fine powder of magnesium silicate in the present invention are measured by the following methods. Average particle size: According to the Coulter counter method. Roundness (FX): FX = A / (π / 4) Dmax Here, A is the cross-sectional area of the powder mm ² , and Dmax is the longest diameter mm of the cross-section. A and Dmax are obtained by adding epoxy resin to spherical fine particles of magnesium silicate, solidifying, cutting with a microtome, and analyzing the cross section of the fine particles with an image analyzer. The value of the sphericity given by this formula is in the range of 0 to 1, and the sphericity is 1. Specific surface area: By BET method by N ₂ adsorption at liquid nitrogen temperature. Oil absorption: According to JIS K-5101 19.

The composition used for the metal vapor-deposited polypropylene film of the present invention may optionally contain an antioxidant, a lubricant, an antiblocking agent and the like within a range not impairing the purpose of the present invention. Adhesiveness with a metal vapor deposition film, that is, vapor deposition film adhesiveness, printability of a vapor deposition surface, fatty acid such as stearic acid and palmitic acid, calcium stearate, a metal salt of a fatty acid such as magnesium stearate, etc. in order not to deteriorate the laminate suitability It is desirable not to mix fatty acid amides such as oleic acid amide and erucic acid amide and derivatives containing other fatty acid-forming groups.

Examples of additives that can be added to the composition include phosphorus-based antioxidants having a molecular weight of 500 or more, phenol-based antioxidants and inorganic fillers. Examples of the antioxidant include tetrakis- [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5.
-Trimethyl-2,4,6-tris (3,5-di-t-
Butyl-4-hydroxybenzyl) benzene, 1,3
5-tris (4-t-butyl-3-hydroxy-2,6
-Dimethylbenzyl) isocyanate, Tris (3,5)
-Di-t-butyl-4-hydroxyphenyl) isocyanurate, tetrakis (2,4-di-t-butylphenyl) 4,4'-biphenylene-diphosphite and the like can be mentioned. Alternatively, 100 parts by weight of the crystalline propylene copolymer may be used in combination of two or more, and
Add from 0.3 to 0.30 parts by weight. Blending of these antioxidants is extremely effective for stability during film formation and during use of the film.

Inorganic fillers that can be blended include hydrotalcite, calcium carbonate, silica and the like. Particularly effective inorganic fillers have an average particle size of 3
It is preferable that the content of the hydrotalcite is not more than μm, and that the blending of the hydrotalcite improves the deposited film adhesion and blocking resistance due to the synergistic effect of the spherical particles of magnesium silicate and the hydrotalcite. The hydrotalcite referred to here is a water-containing basic carbonate of magnesium or aluminum, and either a natural product or a synthetic product may be used. Natural hydrotalcite is said to have a structure of Mg ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O, and synthetic hydrotalcite is Mg and Al.
With different ratios, eg Mg ₄ Al ₂ (OH) ₁₂ C
_{O 3 · 4H 2 O, Mg} 5 Al 2 (OH) 14 CO 3 · 4H 2 O,
_{Mg 10 Al 2 (OH) 22} (CO 3) 2 · 4H 2 O, Mg 6 A
Examples thereof include those having a structure such as l ₂ (OH) ₂₀ CO ₃ .5H ₂ O.

The amount of such hydrotalcite compounded is 0.01 with respect to 100 parts by weight of the crystalline propylene copolymer.
To 0.20 parts by weight are desirable, and in particular 0.03 to 0.15.
Parts by weight are desirable.

The method of blending the spherical fine particles of magnesium silicate or the like into the crystalline propylene copolymer is not particularly limited as long as it is a method of uniformly dispersing the particles, but mixing with a Henschel mixer (trade name), A method in which the mixture is melt-kneaded with an extruder or the like and pelletized is desirable.

The film used for metal deposition is
Examples include an unstretched film obtained by an ordinary T-die method or an inflation method, and a multilayer composite film having two or three or more layers with the film as a surface layer.

The method of depositing metal on the film is usually
Corona discharge treatment on the film surface, performing a surface treatment such as flame treatment, a known method on the treated surface, for example, in a vacuum vapor deposition apparatus equipped with a film feeding section, a vapor deposition section and a winding section,
Using an oil pump and a diffusion pump together, reduce the atmospheric pressure in the device to 10 ^-4 Torr or less, and heat the container containing the desired metal such as aluminum or the filament to which the desired metal is attached to heat the metal. A general method is to melt and evaporate, and vaporized molecules are continuously vapor-deposited on the unwound film surface and wound up. In addition, it is also possible to use a sputtering deposition method or an ion plating method that utilizes the phenomenon that the metal that constitutes the cathode scatters when discharged in a vacuum. The metals to be deposited are aluminum, gold,
Examples of the material include silver, copper, nickel, chromium, germanium and the like, and aluminum is preferable in terms of workability, reflectance and economy. The thickness of the vapor deposited metal layer is usually in the range of 200 to 700 angstroms.

[0021]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The properties in Examples and Comparative Examples were measured by the following methods and standards. (1) Slip property (dynamic friction coefficient): ASTM D189
The coefficient of kinetic friction between the corona-treated surface and the non-treated surface of the raw film measured by the method specified in No. 4 showed the slip property. The smaller this value is, the better the slip property is. (2) Blocking degree: A corona-treated surface and a non-treated surface of a raw film sampled to 2 cm (width) × 7 cm (length) were overlapped over a length of 2 cm, and left under a load of 500 g / cm ² at 50 ° C. for 24 hours. Then, the force required for shear peeling of the sample was determined using a tensile tester. The smaller this value is, the smaller the blocking degree is. (Unit: kg / 4 cm ² ) (3) Scratch resistance (scratch resistance): First, the glossiness of the vapor deposition surface of the aluminum vapor deposition film is determined by ASTM D52.
The measurement is carried out according to the method defined in _{No. 3,} and the value is designated as G ₁ . Next, according to the method defined in ASTM D1894, the vapor deposition surface of the aluminum vapor deposition film is set on the table side and the non-vapor deposition surface is set on the sled side, and the sled is slid. (At this time, the sled weighs 2200 g.) The glossiness of the portion of the aluminum vapor-deposited film on the table side through which the sled has passed is measured and designated as G ₂ . Further, ΔG was obtained from the following formula, and the scratch resistance was evaluated by the value. ΔG = G ₁ −G ₂ The smaller this value, the less likely it is to scratch, indicating that the scratch resistance is good. (unit:
%) (4) Film winding appearance: A film roll obtained by continuously winding a vapor-deposited film of a certain length is visually observed, and the surface is flat and has no wrinkles or lumps. (Good winding appearance), Wrinkles or lumps present (Poor winding appearance)
It was evaluated. (5) Adhesiveness of vapor deposition film: width 1 on the vapor deposition film side of the vapor deposition film
8mm Cellophane adhesive tape (Sekisui Tape Tape R)
After being attached to a length of 70 mm, it was quickly peeled off by hand, and the area ratio of the vapor deposition film remaining on the sample film surface without adhering to the adhesive tape was obtained and ranked. (6) Melt flow rate (MFR) of crystalline propylene copolymer According to JIS K6758 (test conditions: 230 ° C, 2.16 kgf).

Examples 1 to 7 100 parts by weight of a crystalline ethylene-propylene-butene-1 ternary random copolymer having an MFR of 7.0 g / 10 min and a Tm of 137 ° C. was added with tetrakis- as an antioxidant.
[Methylene-3- (3 ', 5'-di-t-butyl-4'
-Hydroxyphenyl) propionate] methane 0.1
2 parts by weight, 0.03 parts by weight of hydrotalcite and the additives shown in Table 1 below are mixed and mixed in a Henschel mixer (trade name), and then melt-kneaded at 220 ° C. using an extruder to form pellets. A composition was obtained. The obtained composition was extruded at a melt-kneading temperature of 220 ° C. using an extruder with a T-die having a diameter of 65 mm, and the air chamber and the surface temperature of 30
A film is formed by rapid cooling with a cooling roll of ℃, and one side of the film is immediately subjected to corona discharge treatment so that the wetting index becomes 40 dyn / cm, and the film is wound and rolled to a thickness of 25 μm and a width of 60 cm. An original film was obtained. After cutting the obtained raw film to a width of 50 cm using a slitter, it was set in a continuous vacuum vapor deposition apparatus, and while continuously feeding the film, aluminum vapor deposition was performed on the corona-treated surface under a vacuum of 10 ^-5 Torr. It is wound and wound, and the vapor deposition film has a thickness of about 500 Å and a length of 1000 m.
A single-sided aluminum vapor-deposited film wound up in a roll shape was obtained. The characteristics of the vapor deposition film were evaluated using the obtained metal vapor deposition film, and the results are shown in Table 2. As is clear from Table 2, the vapor-deposited films of Examples 1 to 7 have good slip properties, blocking properties, scratch resistance, winding shapes, and vapor-deposited film adhesion.

Comparative Examples 1-2 As Comparative Examples 1 and 2, Comparative Example 1 has a sphericity (Fx) of 0.5.
5. In Comparative Example 2, a film was prepared according to Example 1 except that magnesium oxide fine particles having a magnesium oxide content of 50% by weight and deviating from the range of the magnesium silicate spherical fine particles used in the present invention were used. Examples 1-
Aluminum metal was vapor-deposited according to No. 7, to obtain a single-sided aluminum vapor-deposited film. The characteristics of the films obtained in each comparative example are shown in Table 2. As is apparent from Table 2, in Comparative Example 1 in which the sphericity of the magnesium silicate fine particles used is out of the range, the slip property and winding shape of the film are deteriorated, and in the Comparative Example 2 in which the magnesium oxide content is out, the scratch resistance of the obtained film is increased. It turns out that the sex deteriorates.

Comparative Examples 3 to 8 Films were prepared in accordance with Examples 1 to 7 except that the additives shown in Table 1 below were blended, and Examples 1 to 7 were prepared.
Aluminum metal was vapor-deposited according to the above procedure to obtain a single-sided aluminum vapor-deposited film (however, Comparative Example 3 did not use an additive). The characteristics of the films obtained in each comparative example are shown in Table 2. As is clear from Table 2, the obtained film is inferior in any one of the slip property, blocking property, scratch resistance, winding form, and vapor deposition film adhesion property.

[0025]

EFFECTS OF THE INVENTION The metallized polypropylene film of the present invention uses a composition in which a specific amount of specific spherical particles of magnesium silicate is blended, so that the obtained metallized film has a slip property, a blocking resistance and a scratch resistance. It has excellent properties such as winding shape and adhesiveness of deposited film. Further, it is superior in all properties to a metal vapor deposition film using a composition containing silica, which is an anti-blocking agent, synthetic zeolite, and silicone oil, which is a slip agent, which have been conventionally used. Further, the metal vapor-deposited polypropylene film of the present invention has a vapor-deposited film firmly adhered to the film, and the workability is greatly improved without lowering the printability of the vapor-deposited surface and the adhesiveness with other films. Therefore, it is possible to manufacture a vapor-deposited film having a wide width and a long length which has never been obtained with high productivity. Also, since it has excellent slip resistance, scratch resistance, and blocking resistance, wrinkles and scratches are less likely to occur in the printing process, laminating process, packaging process, and bag-making process,
It has excellent performance such that the production speed can be improved, and it can be suitably used in a wide range of fields such as packaging and decoration.

[0026]

[Table 1]

[0027]

[Table 2]

Claims (2)

[Claims] 1. 100 parts by weight of crystalline propylene copolymer, average particle size 0.5 to 7 μm, magnesium oxide content 40% by weight or less, sphericity (Fx) 0.7 or more, BE
A metal is vapor-deposited on a film obtained by using a composition containing 0.01 to 1 part by weight of spherical fine particles of magnesium silicate having a specific surface area of 500 m ² / g or more and an oil absorption amount of 150 ml / 100 g or less by T method. Metallized polypropylene film. 2. The metallized polypropylene film according to claim 1, wherein the crystalline propylene copolymer is a crystalline propylene-α-olefin copolymer having a propylene component of 80% by weight or more and a crystal melting point of 150 ° C. or less. .