JPH0533906B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a metallized film. For more details, see the adhesion of the deposited film and the printability on the deposited surface.
The present invention relates to a metal-deposited polypropylene film or sheet (hereinafter simply referred to as metal-deposited film) that has excellent lamination suitability, anti-blocking properties, and slip properties. (Prior art) In recent years, metal-deposited films, which are made by depositing metals on plastic films under vacuum, have been used to make gold and silver threads, building materials, packaging films, etc., taking advantage of their excellent decorative properties, gas barrier properties, and light blocking properties. widely used. In particular, aluminum-deposited films are widely used mainly for packaging purposes, but commercially available propylene homopolymers or polypropylenes such as propylene-based copolymers of propylene and ethylene or α-olefin have traditionally been used. When a metal is vapor-deposited onto a film made of resin, the adhesion between the base film and the vapor-deposited film is weak, and if the vapor-deposited metal is aluminum, the printability of the vapor-deposited surface and the adhesion with other types of films are significantly reduced. These problems have been a major obstacle in developing new applications. The present inventor investigated the cause of the problems with these conventional commercially available vapor-deposited polypropylene films and studied ways to improve them, and previously proposed the problem in Japanese Patent Application Laid-Open No. 59-25829. However, although this proposed metal-deposited film can produce an unprecedented metal-deposited polypropylene film, as the amount of polyethylene resin added increases, the impact resistance and tear resistance decrease significantly. is 10% by weight
If the amount is less than 10% by weight, especially less than 5% by weight, the slip property is poor, and if the amount is less than 4%, the blocking resistance is significantly reduced. Furthermore, JP-A No. 60-51553 discloses that when cooling polypropylene, the temperature of water or a cooling roll is raised to 50°C or higher, and the film surface of a specific density obtained by slow cooling is subjected to corona discharge treatment, and then metal is applied. A metal-deposited polypropylene film has been proposed, but this film is brittle and
Moreover, it has the disadvantage that the heat sealing temperature of the film becomes high. (Problems to be Solved by the Invention) The present inventors have developed a metal-deposited film that eliminates the above-mentioned drawbacks, that is, has a beautiful metallic luster, has good adhesion of the deposited film, printability of the deposited surface, and adhesion to other types of films. We conducted intensive research to obtain a metal-deposited film with improved impact resistance and slip resistance without sacrificing properties.
As a result, by adding specific amounts of specific polyethylene and organic resin fine powder that does not melt or decompose at temperatures below 300°C (hereinafter referred to as organic resin fine powder) to polypropylene resin, each of them can be added individually. The present invention was completed based on the discovery that a metal-deposited film with much better properties and better balance could be obtained. As is clear from the above description, the objects of the present invention are to have a beautiful metallic luster, excellent adhesion of the vapor deposited film, printability of the vapor deposition surface, adhesion between the vapor deposition surface and other types of films, and impact resistance. An object of the present invention is to provide a metal-deposited polypropylene film with improved slip properties and slip properties. (Means for solving the problems) The present invention has the following configuration. A metal-deposited polypropylene film in which a metal is vapor-deposited on the film surface using a composition in which 1 to 10 parts by weight of a polyethylene resin having a density of 0.930 or more and 0.01 to 0.5 parts by weight of organic resin fine powder are added to 100 parts by weight of a polypropylene resin. . The metallized polypropylene film of the present invention has a density of
Also included is a metal-deposited polypropylene sheet in which a metal is deposited on a sheet using a composition containing 1 to 10 parts by weight of a polyethylene resin having a molecular weight of 0.930 or more and 0.01 to 0.5 parts by weight of an organic resin fine powder. The polypropylene resin used in the present invention is
These include homopolymers of propylene, copolymers of propylene with propylene as the main component and ethylene or α-olefin, and mixtures thereof. Specifically, crystalline polypropylene, crystalline ethylene,
These are propylene copolymers, crystalline propylene/α-olefin copolymers, crystalline ethylene/propylene/α-olefin terpolymers, and mixtures thereof, of which the propylene component is
Contains 70% by weight or more, preferably 80% by weight or more,
50% by weight of crystalline ethylene/propylene copolymer, crystalline propylene/α-olefin copolymer, or crystalline ethylene/propylene/butene-1 terpolymer and mixtures thereof with a crystal melting point of 120 to 150°C. The present invention is particularly effective and preferable for those including the above. Here, the crystal melting point (Tm) is the peak temperature of the endothermic curve accompanying the melting of the crystal obtained by heating a 10 mg sample at a rate of 10°C/min in a nitrogen atmosphere using a scanning differential calorimeter. point to The polyethylene resin added to the polypropylene resin in the present invention is medium/high density polyethylene with a density of 0.930 or more, and includes a copolymer of ethylene and other α-olefins, the main component of which is ethylene. If the density of polyethylene is less than 0.930, it is difficult to obtain the improvement effect aimed at by the present invention. Polyethylene with a density of 0.945 or more is particularly desirable since it is effective when added in small amounts. The amount of the polyethylene resin added is in the range of 1 to 10 parts by weight, preferably 2 to 5 parts by weight, per 100 parts by weight of the polypropylene resin. If it is less than 1 part by weight, there will be little improvement in blocking resistance or slip property, and if it exceeds 10 parts by weight, the film will become extremely brittle and easily tear, which is not preferred. In addition, the polypropylene resin and polyethylene resin used in the present invention have a melt flow rate ratio of 0.5 or more, that is, a ratio of polypropylene melt flow rate (MFR-PP) to polyethylene melt flow rate (MI-PE), In other words, it is desirable to select and use MI-PE/MFR-PP≧0.5. If this ratio does not reach 0.5, the compatibility decreases, and the film surface becomes extremely rough, or a fish-eye-like unevenness occurs on the film surface. When this ratio is between 0.5 and 1.0, the film becomes matte, and when it exceeds 1.5, a deposited film with excellent metallic luster is obtained. In addition,
Here, polyethylene MI-PE is JIS K 6760
Melt flow rate of polyethylene test method (190℃, 2.16Kgf), MFR of polypropylene
PP means the melt flow rate (230°C, 2.16Kgf) of JIS K 6758 polypropylene test method. The organic resin fine powder used in the present invention is a resin that does not melt or decompose at the processing temperature of crystalline polypropylene, that is, at a temperature of 300° C. or lower, and has a spherical shape. The organic resin fine powder is known to be either thermoplastic or thermosetting resin, but in the present invention, it is a spherical fine powder that does not substantially deform at the processing temperature of polypropylene. Specifically, examples of this organic resin spherical fine powder include silicone resin, which is a three-dimensional polymer having an inorganic Si-O-Si bond as a structural unit and an organic group such as a methyl group or a phenyl group in the side chain; A fine spherical powder of benzoguanamine resin, which is a condensation product of benzoguanamine/formaldehyde, is preferable, and one having an average particle size of 5 μm or less is particularly preferable. The amount of the organic resin fine powder added is 0.01 to 0.5 parts by weight per 100 parts by weight of the polypropylene resin,
If it is less than 0.01 part by weight, there will be no improvement in blocking resistance, slip resistance, vapor deposition strength with metal, etc.;
Even if it is added in excess of 1 part by weight, the above-mentioned improvement effect will not increase, and instead the adhesion, appearance, etc. will deteriorate, which is not preferable. Additives that can be further added to the composition comprising the crystalline polypropylene resin, polyethylene resin, and organic resin fine powder used in the present invention include phenolic or phosphorus antioxidants with a molecular weight of 500 or more; Examples include inorganic fillers and small amounts of other types of polymers, but additives that do not substantially contain fatty acid derivatives such as higher fatty acid salts and fatty acid amides, which have conventionally been commonly used for polypropylene films, are desirable. As a mixing method for obtaining the composition used in the present invention, any of the commonly known Henschel mixers (trade name), Banbury mixers, various kneaders, extruders, etc. can be used. Alternatively, a composition may be obtained by mixing polypropylene resin, polyethylene resin, and the above-mentioned organic resin spherical fine powder into pellets, or adding the above-mentioned organic resin powder to either or both of the polypropylene resin and the polyethylene resin. They may be mixed, pelletized, and then mixed during film molding. The method for forming a film using the above-mentioned composition may be either the well-known T-die method or the tubular method. It is desirable to form the film under conditions such as rapid cooling below ℃. Cooling at a temperature exceeding 50°C is not preferable because the film becomes brittle and the low-temperature sealing properties deteriorate. The film thus obtained is subjected to a surface treatment on the surface to be deposited in accordance with a conventional method, and then a metal is deposited under vacuum to obtain the desired metal-deposited polypropylene film. For this surface treatment, known methods such as flame treatment, corona discharge treatment, and plasma treatment can be used, but corona discharge treatment, which can be carried out between film formation and winding during film production, is the simplest. To illustrate the effect of this corona discharge treatment, if the corona discharge treatment is not performed, the adhesion of aluminum to the film during vapor deposition is insufficient, making it impractical.
The degree of this corona discharge treatment is preferably such that the wettability index measured according to JIS K 6768 is 37 dyn/cm or more, particularly preferably 39 to 43 dyn/cm. In order to strengthen the adhesion between the film and aluminum, it is possible to coat the corona discharge treated surface of the film with a substance that has good affinity with metals, such as polyester, polyurethane, epoxy resin, etc., before vapor deposition. Although it is
Of course, this method may be used in combination. Any known method can be used to vacuum-deposit a metal onto a film made of the composition of the present invention. A pump and a diffusion pump are used together to reduce the pressure inside the device to 10 ^-4 Torr or less, and a container containing a desired metal such as aluminum or a filament to which the desired metal is attached is heated to melt and evaporate the metal. A common method is to allow the evaporated molecules to be continuously deposited on the surface of the film, and then wind it up. In addition, sputtering vapor deposition or ion plating, which utilizes the phenomenon in which the metal constituting the cathode scatters when discharged in a vacuum, is also possible. Note that the metal to be vapor-deposited includes aluminum, gold, silver, copper, nickel, chromium, germanium, selenium, titanium, tin, zinc, etc., but aluminum is preferable from the viewpoint of workability, reflectance, economical efficiency, etc. The thickness of the metal deposited layer typically ranges from 200 to 700 Å. (Examples) Hereinafter, the present invention will be specifically explained using Examples and Comparative Examples, but the present invention is not limited thereto. The evaluation method used in Examples and Comparative Examples was as follows. (1) Blocking force: overlap the non-deposited surfaces of 2 cm (width) x 7 cm (length) samples over a length of 2 cm,
After being left at 40℃ for 24 hours under a load of 250g/ ^cm2 ,
Using a tensile tester, the force required for shearing and peeling the sample was determined as blocking force. (Unit: g/
4cm ² ) (2) Slip resistance (sliding friction coefficient): ASTM
It is expressed as the coefficient of static friction measured by the method specified in D1894-63. (3) Wetting index: The wetting index of both the original film and the vapor-deposited surface of the vapor-deposited film was measured by the method of JIS K 6758. (Unit: dyn/cm) (4) Punching impact strength: Measured by the method of ASTM D781. (Unit: Kg-cm) (5) Adhesiveness of vapor deposited film: After pasting a 70 mm length of 18 mm wide cellophane adhesive tape (trade name: Sekisui Cellotape) on the vapor deposited film side of the vapor deposited film, quickly tape it by hand. After peeling off, the area ratio of the vapor deposited film remaining on the sample film surface without adhering to the adhesive tape was determined, and the adhesion of the vapor deposited film was evaluated by ranking it as shown below.

[Table] (6) Suitability for printing and laminating on vapor-deposited surfaces: Overlap the vapor-deposited surface (metal surface) and non-evaporated surface (film surface) of a film with metal (aluminum) vapor-deposited on one side, and apply a load of 1 kg/100 cm ^2. After leaving it for 72 hours in an atmosphere with a temperature of 40℃ and a relative humidity of 95%,
Measure the wettability index (unit: dyn/cm) of the deposition surface. In order to be evaluated as having good suitability for printing and lamination, this wettability index needs to be 35 or more, preferably 37 or more, and the following rankings were performed based on this wettability index to evaluate the suitability for printing and lamination of the vapor-deposited surface.

[Table] (7) Film winding appearance: Observe with the naked eye the film roll obtained by continuously winding a certain length of vapor-deposited film. ○ (good rolling appearance), those with wrinkles or thickening were evaluated as × (poor rolling appearance). Examples 1 to 4, Comparative Examples 1 to 5 As polypropylene resin, MFR=5.5,
Tm = 135°C, 100 parts by weight of a crystalline ethylene-propylene-butene-1 terpolymer containing 92% by weight of propylene component and 3.5% by weight of ethylene component,
Tetrakis [methylene-3-
(2',5'-di-t-butyl-4'-hydroxyphenyl)propionate] 100 parts by weight of a polypropylene resin blended with 0.12 parts by weight of methane and the polyethylene and organic resin fine powder shown in Table 1 below. After blending and mixing using a Henschel mixer (trade name), the mixture was melt-kneaded using an extruder at 220°C to obtain a pellet-like composition. This composition has a caliber of 65
mm extruder and T-die at a melting temperature of 220℃, rapidly cooled with an air knife and a roughened Eichir roll with a surface temperature of 35℃, and formed into a film. Immediately, one side of the film had a wettability index of 41dyn/cm. After corona discharge treatment, the film was wound up to obtain a rolled raw film with a thickness of 25 μm.
This film was cut to a width of 60cm using a slitter, and then set in a continuous vacuum deposition device, and while the film was continuously fed out, aluminum was deposited on the corona discharge treated surface under a vacuum of 10 ^-5 Torr, and the film was wound up. , the thickness of the deposited film is 370 Å, the length is 2000 Å
A roll-shaped aluminum vapor-deposited film of m was obtained. In addition, as Comparative Examples 1 to 5, 100 parts by weight of the same polypropylene resin as used in Examples 1 to 4 and predetermined amounts of polyethylene and organic resin fine powder as shown in Table 1 below were blended. 1
Pelletization, film creation, surface treatment and metal vapor deposition are carried out in accordance with 4.
A rolled aluminum vapor-deposited film having a thickness of 25 μm, a thickness of 370 Å, and a length of 2000 m was obtained. The metal deposited films obtained in each of the Examples and Comparative Examples were used to evaluate the properties of the deposited films.
The results are shown in Table 1. As is clear from Table 1, the vapor-deposited films made of the compositions of the present invention (Examples 1 to 4) were superior to the vapor-deposited films made of compositions obtained by adding polyethylene and organic resin fine powder individually. It can be seen that this is a deposited film with extremely improved properties and excellent balance. In particular, a deposited film with excellent blocking resistance and slip properties can be obtained by adding a small amount of polyethylene due to its synergistic effect with the organic resin fine powder, so it is extremely useful because it can suppress the drop in impact resistance caused by the addition of polyethylene. Examples 5 to 9, Comparative Examples 6 to 9 As polypropylene resin, MFR=8.0,
Tm=140℃, crystalline ethylene/propylene random copolymer containing 4.2% by weight of ethylene component
To 100 parts by weight, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t) was added as an antioxidant.
-butyl-4-hydroxybenzyl)benzene
100 parts by weight of polypropylene resin blended with 0.10 parts by weight, high density polyethylene with a density of 0.960 and MI5.0
2.0 parts by weight and various additives shown in Table 2 below were blended, mixed in a Henschel mixer (trade name), and then melt-kneaded at 200°C using an extruder to obtain a pellet-like composition. . A raw film was prepared from this composition in accordance with Examples 1 to 4, cut with a slitter, aluminum vapor-deposited, and wound up to give a film thickness of 25μ, a thickness of 370Å, and a width of 370Å.
A roll-shaped single-sided aluminum vapor-deposited film having a length of 60 cm and a length of 500 m was obtained. In addition, as Comparative Examples 6 to 9, 100 parts by weight of the same polypropylene resin and 2.0 parts by weight of high-density polyethylene as used in Examples 5 to 9, and various additives shown in Table 2 below were blended. Film thickness according to ~9
A roll-shaped single-sided aluminum vapor-deposited film having a thickness of 25 μm, a vapor-deposited film thickness of 370 Å, a width of 60 cm, and a length of 500 m was obtained. The properties of the metallized films obtained in each of the Examples and the Comparative Examples were evaluated.
The results are shown in Table 2. As is clear from Table 2, even if the amount of polyethylene added is extremely small, a vapor-deposited film with extremely improved properties can be obtained by using it in combination with organic resin spherical fine powder; however, when using other fatty acid-based additives, It can be seen that Comparative Examples 7 and 8 containing zeolite, Comparative Example 6 without additives, and Comparative Example 9 with synthetic zeolite added have significant differences in some of the properties, such as significantly inferior properties or very small improvement effects. Example 10 Polypropylene resin 100 used in Examples 5 to 9
Spherical silicone resin powder (average particle size
After blending 0.10 parts by weight of 0.7μ) in a Henschel mixer (trade name), the mixture was melt-kneaded in an extruder to obtain Composition A in the form of pellets. Furthermore, 0.10 parts by weight of the same antioxidant as in Examples 5-9 was added to 100 parts by weight of the polyethylene used in Examples 5-9, and the mixture was mixed and melt-kneaded in the same manner to obtain a composition B in the form of pellets. To 100 parts by weight of this composition A, add 3 parts of composition B.
Parts by weight were blended and mixed in pellet form at room temperature to obtain a mixed composition C. This mixed composition C,
A raw film was prepared in accordance with Examples 1 to 4, cut with a slitter, subjected to aluminum vapor deposition, and rolled up, so that the film thickness was 25 μm and the thickness of the deposited film was 350 μm.
A roll-shaped single-sided aluminum vapor-deposited film with a width of 60 cm and a length of 3000 m was obtained. This vapor deposited film has a blocking power of 350,
The polypropylene vapor-deposited film had slip property of 0.61, roll appearance ○, adhesion of the vapor-deposited film rank 5, and suitability for printing and lamination of the vapor-deposited surface ○, and had excellent properties not seen before.

【table】

[Table] (Effects of the invention) The metal vapor-deposited polypropylene film of the present invention has an extremely good winding appearance after vapor deposition, and also has good impact resistance of the vapor-deposited film and good heat sealability on the non-vapor-deposited surface. It is a metal-deposited film with excellent vapor deposition properties, printability and adhesion of the vapor-deposited surface, and can be suitably used for packaging, decoration, etc.

Claims (1)

[Claims] 1. Density 0.930 per 100 parts by weight of polypropylene resin
1 to 10 parts by weight of the above polyethylene resin and
A metal-deposited polypropylene film in which metal is deposited on the film surface using a composition containing 0.01 to 0.5 parts by weight of organic resin fine powder that does not melt or decompose at temperatures below 300°C. 2. Ratio of melt flow rate of polypropylene resin (MFR-PP) to melt flow rate of polyethylene resin (MI-PE) Patent for use of polypropylene resin and polyethylene resin with MI-PE/MFR-PP of 0.5 or more A metallized polypropylene film according to claim 1. 3. Claim 1, wherein the organic resin fine powder that does not melt or decompose at temperatures below 300°C is spherical silicone resin fine powder with an average particle size of 5 μ or less or spherical benzoguanamine resin fine powder with an average particle size of 5 μ or less The metallized polypropylene film described. 4 Polypropylene resin contains propylene component
Crystalline ethylene-propylene copolymer, crystalline ethylene-propylene-butene-1 ternary copolymer, or crystalline propylene-α-olefin copolymer containing 70% by weight or more and a crystal melting point of 150°C or less, or these The metallized polypropylene film according to claim 1, which is a mixture containing 50% by weight or more of one or more of the following. 5. The metallized polypropylene film according to claim 1, wherein the polyethylene resin is high-density polyethylene having a density of 0.945 or more.