JPH0252735A - Metal evaporated film - Google Patents

Abstract

PURPOSE:To improve the printing properties of an evaporating surface and the suitability of laminating by evaporating a metal on one surface of a laminate with two surface layers having specific constitution. CONSTITUTION:A metal is evaporated onto the layer A of two layers or more of laminated films containing the layer A and a layer B as surface layers. The layer A is composed of a composition in which 0.3-30pts.wt. grafted polyethylene, which is acquired by graft-polymerizing at least one kind selected from unsaturated carboxylic acid or a derivative thereof, is compounded to a 100pts. wt. crystalline polypropylene resin. The layer B consists of a composition in which 1-10pts.wt. high-density polyethylene having density of 0.94 or more is compounded to a 100pts.wt. crystalline polypropylene group copolymer having a crystalline melting point lower than the crystalline polypropylene resin used in the layer A by at least 5 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to metallized films. More specifically, the present invention relates to a metal-deposited film that has excellent adhesion of the vapor-deposited film, printability and lamination suitability of the vapor-deposited surface, and excellent anti-blocking and slip properties.

(Prior Art) Metals are deposited on plastic films or sheets to give them decorative properties, gas barrier properties, light blocking properties, etc., and are widely used for food packaging, construction materials, etc.

In particular, aluminum vapor-deposited films are widely used mainly for packaging purposes, but conventionally commercially available films made of polypropylene resin with metal vapor-deposited have weak adhesion between the base film and the vapor-deposited film. When the metal is aluminum, there are many problems such as the printability of the vapor-deposited surface and the adhesion with other types of films are significantly reduced, which has been a major obstacle in developing new applications.

(Problems to be Solved by the Invention) The present inventor investigated the cause of the problems of these conventional products and considered countermeasures, and investigated calcium steering acid, oleic acid amide, erucic acid amide, etc., which are usually added to polypropylene films. It was found that higher fatty acid derivatives were the main cause of these problems. But these high-grade fats! Il! Films that do not contain derivatives have significantly poor slip and blocking resistance, and especially in the case of thin films, wrinkles are extremely likely to occur during film processing, vapor deposition, and other post-processing processes. And, it is uniform with no curling or curling bumps.
: It was difficult to obtain a film in C-volume form.

In addition, this higher fatty acid derivative bleeds out over time, causing a significant decrease in the adhesion of the deposited film, and has been a major hindrance to the development of applications for boria-pyrene metal deposited films.

The purpose of the present invention is to solve the problems of these conventional methods, and to produce a metal vapor-deposited film that has excellent adhesion and processability, and has a good roll shape, especially an aluminum film that has excellent printability and lamination suitability on the vapor-deposited surface. An object of the present invention is to provide a vapor-deposited film.

(Means for Solving the Problems) As a result of intensive research conducted by the present inventors to solve the above problems, one surface of a laminate having two surface layers (A) and (B) having a specific configuration. The present invention was achieved by discovering that the problem can be solved and obtained by vapor-depositing metal.

That is, the present invention provides a metal-deposited film (A) layer formed by depositing a metal on layer (A) of a laminated film of two or more layers containing the following (A) layer and (B) R as a surface layer: Crystalline polypropylene At least 1@ selected from unsaturated carboxylic acids or derivatives thereof per 100 parts of the system resin
0.3 grafted polyethylene obtained by graft polymerization of
A layer consisting of a composition containing ~30 parts by weight.

(B) Layer: High-density polyethylene with a density of 0.94 or more per 100!1 parts of a crystalline polypropylene copolymer having a crystal melting point 5°C or more lower than that of the crystalline polypropylene resin used in the (A) layer. A layer consisting of a composition containing 1 to 10 parts by weight.

It is related to.

The configuration will be explained in more detail below.

The crystalline polypropylene resin used in layer (A) of the present invention is propylene alone or a copolymer of propylene as a main component with ethylene or an α-olefin having 4 or more carbon atoms, such as crystalline boria 0 pyrene. , crystalline ethylene/propylene random copolymer, crystalline propylene/
Examples include a butene-1 copolymer, a crystalline propylene/ethylene/butene-1 terpolymer, and the like. These can be subjected to Sino-German polymerization or copolymerization using known stereoregular α-olefin catalysts such as the Ziegler-Natsuta type, using known methods such as the slurry method, solution method, and gas phase polymerization method. It can be obtained by

These polymers and copolymers are widely known, but in the layer (A) of the present invention, crystalline polypropylene, which contains 80% by weight or more of a propylene component and has a crystal melting point of 145
℃ or higher or a mixture thereof is desirable. Of these, the crystal melting point is 150℃
The above are particularly desirable.

In addition, the grafted polyethylene used in the layer (A) of the present invention can be prepared by adding unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, or anhydrides of the above acids to low density to high density by various known methods. polyethylene,
It can be obtained by graft polymerization to a known polymer whose main component is ethylene, such as linear low-density polyethylene. There are various known methods for grafting unsaturated carboxylic acids. For example, an ethylene polymer and an unsaturated carboxylic acid or its anhydride are dissolved in an organic solvent such as benzene, and then an organic peroxide (e.g. G-t-
Butyl peroxide) can be added thereto, heated to react with stirring, cooled after the reaction, washed, filtered, and dried, or can be obtained by combining the dissolved MU in an extruder. As the unsaturated carboxylic acid, maleic anhydride is used, and as the polyethylene, the ethylene content M is 80
It is preferable to conduct a heating reaction (or melt-mixing) in the presence of an organic peroxide using a material having a density of 0.93% or more and a density of 0.93 or more.

The grafting ratio of the graft monomer to polyethylene is usually 0.1 to 20% by weight, preferably 0.2 to 10% by weight.
Heavy weight% is good. In addition, the amount of grafted polyethylene added is 0.3 to 30 parts by weight per 100 parts by weight of the crystalline polypropylene resin to achieve both adhesion of the deposited film and high brightness (gloss) of the deposited surface. For this purpose, grafted polyethylene containing grafted polyethylene alone or a mixture of grafted polyethylene and ungrafted polyethylene and adjusted so that the maleic anhydride content is in the range of 0.01 to 2% by weight can be used. It is particularly desirable to add 1 to 20 parts by weight of polyethylene.

As mentioned above, the grafted polyethylene used in the present invention includes grafted polyethylene alone or a mixture of ungrafted polyethylene with other polymers and additives.

Furthermore, the crystalline propylene copolymer used for layer (B) has a crystal melting point of 5% higher than that of the polymer or copolymer for layer (A).
It must be lower than ℃.

If the melting point difference between the layer and the layer (A) is less than 5° C., it is not preferable because the deposited film at the sealing portion is likely to change in quality and cracks may occur during heat sealing. This (B) layer has a crystal melting point of 14
A random copolymer having a melting point difference of 10°C or more with layer (A) at 5°C or less is particularly desirable.

This desirable random copolymer is a crystalline ethylene/propylene random copolymer with an ethylene copolymerization ratio of 4 to 8iJffi%, and a butene-1 copolymerization ratio of 1%.
Crystalline propylene-butene-1 copolymer with a copolymerization ratio of 0 to 30% by weight or crystalline ethylene-butene-1 copolymer with a copolymerization ratio of 0.3 to 5% by weight of ethylene and 1 to 20% by weight of butene-1. Examples include propylene-butene-1 terpolymer.

The crystalline propylene copolymer used for layer (B) in the present invention has a density of 0.94 per 100 parts of the copolymer.
1 to 10 parts by weight of the above high-density polyethylene is added, and this high-density polyethylene is a known polyethylene that is polymerized by a medium-low pressure method and has ethylene as its main component. Flow rate (VFR
: 190℃.

2.16Kg) is 2.0 or more and the MFR of the copolymer (
MFR: 230°C, 2.16 Ky), that is, the MFR of polyethylene/MFR of the copolymer is preferably 0.5 or more (those in the range of 0.7 to 5.5 are preferably 2 to
It is particularly recommended to add 6 parts by weight.

The composition of the crystalline polypropylene resin and grafted polyethylene used in the (A) layer of the present invention and the composition of the crystalline propylene copolymer and high-density polyethylene used in the (B) layer include the present invention. Although known additives and other types of polymers can be added within a range that does not impede the purpose of the process, very specific antioxidants, It is desirable to limit the amount to inorganic fillers and other types of polymers, and to minimize the amount added.

That is, fatty acids and their derivatives, which are the main components of lubricants, antistatic agents, neutralizing agents, etc. that are conventionally added to films or sheets made of crystalline polypropylene resin, additives that are liquid at room temperature, plasticizers, etc. It is not preferable to include these, since they not only reduce the adhesive strength of the vapor-deposited film but also significantly impair the printability and adhesion of the vapor-deposited surface.

Therefore, desirable additives that can be added are extremely limited, and specifically include heat stabilizers with a molecular weight of 500 or more, antioxidants, inorganic fillers such as silica, zeolite, and calcium carbonate, and inhibitors such as the above fatty acids and their derivatives. It is desirable to select and use polyethylene resins containing no substances and having a density of less than 0.94, amorphous ethylene/α-olefin copolymers, ethylene/α-olefin copolymer rubbers, organic hardened resin fine powders, and the like.

(A) A method of blending the crystalline polypropylene resin and grafted polyethylene used in the layer of the present invention, (B)
The method of blending the bu-O-pyrene copolymer and high-density polyethylene used for the layer, and the method of blending them with the above-mentioned limited additives, can be any method as long as they are uniformly dispersed and mixed. But it's okay. Specifically, for example, it is possible to mix well with a ribbon blender, Henschel mixer, etc. to uniformly disperse the mixture, or to melt and knead the mixture using an extruder, etc., cool it, and use it as a pellet-like composition. .

2 containing layers (A) and (B) of the present invention as surface layers
The method of laminating a laminated film of more than one layer is by a known method such as melt extrusion, coextrusion multilayer die method, feed block method, etc. using two or more extruders, and then laminating in a molten state.
Coextrusion lamination method obtained by cooling in a water tank or cooling roll, etc.
A method of laminating by melt extrusion on one or both surfaces of the film, after forming the (A) layer and (B) layer into a film,
Known methods such as dry (or solvent-free) lamination, in which two or more films are laminated together using an adhesive so that both layers are on the surface, can be used; however, in the present invention, ( A) and (B) A coextrusion lamination method in which the thicknesses of both surface layers can be adjusted arbitrarily is particularly effective. It is particularly desirable to use this coextrusion lamination method and select the thickness ratio of the two layers (A) and (B) so that one of them accounts for 20 to 80% of the total thickness of both layers. The basic structure of the present invention is two layers (A)/(B), but as a variation thereof, three layers are used.
Using a coextrusion device capable of laminating more than one type of film, it is also possible to add a 1 m layer of the same or different types to form a laminate film of three or more layers. A metal is vapor-deposited on the (A) layer surface of the thus obtained laminate, and it is desirable to perform a surface treatment on this (A) layer surface in order to improve the adhesion of the vapor-deposited film. This surface treatment method includes corona discharge treatment, plasma treatment,
Flame treatment, ash treatment, acetic acid treatment, etc. may be used, but corona discharge treatment is simple and most desirable because it allows continuous treatment of the laminate and can be easily carried out during film formation and before winding. is also desirable. Note that during this treatment, an effect promoting method such as under heating or under an atmosphere of an inert gas or the like may be used. The degree of this surface treatment is JIS
K6758r Wetting test method for polyethylene and polypropylene The sag index is 37 d.
It is particularly desirable to process the film so that it is equal to or higher than V n /cm.

In addition, after surface treatment of this (A)l, polyester-based,
Anchor coats (A) made of polyurethane, epoxy resin, etc.
It is also possible to perform vapor deposition after applying nchor Cort.

Next, the method of vapor depositing metal on this (A) layer is the vacuum vapor deposition method, that is, in a vacuum vapor deposition apparatus, the atmospheric pressure inside the apparatus is reduced to 10
The surface of the film or sheet is heated to melt and evaporate the metal by reducing the pressure to about 10' Torr and attaching a target metal such as aluminum, nickel, gold, silver, etc., and releasing the evaporated molecules onto the surface of the film or sheet. The most common method is to continuously deposit the cathode and wind it up, but other methods are also possible, such as sputtering deposition and ion blating, which take advantage of the phenomenon in which the metal that makes up the cathode scatters when discharged in a vacuum. . The metals to be vapor-deposited include aluminum, gold, silver, copper, nickel, chromium, germanium,
Examples include titanium, selenium, tin, zinc, etc., but aluminum is particularly desirable in terms of workability, economy, brightness, safety, etc.

The thickness of the metal vapor-deposited layer is usually desirably about several tens to several hundred angstroms in terms of adhesiveness and durability.

The metal-deposited laminated film of the present invention thus obtained is useful on its own, but it can also be used to improve decorativeness and product image by taking advantage of the excellent suitability for printing and lamination on the metal-deposited surface. Printed or laminated with other films or sheets, such as eroded polyester, nylon, and EVAL, which are anchor-coated on the vapor-deposited surface (81
By using the layers as inner surfaces and heat-sealing them, it is possible to create a package with further improved functionality, which is extremely useful.

(Method of Measuring Properties and Criteria for Evaluation) Measurement and evaluation of properties in the present invention were performed using the following methods and criteria.

(1) Density: Measured at 23°C based on JIS K7112. (Unit 2g/Cm3) (2) Melt flow rate (VFR): JISK721
0-1976, propylene polymers and copolymers (including grafted products) were tested under test conditions 14 (230°C,
2.16KS, polyethylene was tested under test condition 4 (19
Measured at 0°C and 2.16 kg). (Unit: 9/10 minutes) (3) Crystal melting point (Tm): Scanning differential calorimeter (abbreviation:
DSC) under a nitrogen atmosphere, 10 μ samples were
It is expressed as the peak temperature (unit: 2°C) of the endothermic curve accompanying the melting of the crystal obtained by heating the crystal at a rate of 4°C/min.

(4) Wetting index: Measured on both the film and the metal-deposited surface using the method of JIS K6768. (Unit: dyn/c
m) (5) Adhesion of vapor deposited film: Two-wheel stretched polyester (PET) is attached to the vapor deposited film side of the vapor deposited film via a urethane adhesive.
) It is expressed as the 90 degree peel strength (unit: g/l 5 shoes) required to separate the two films after they are pasted together. Usually, peeling occurs between the (A) layer surface and the deposited film. The larger this value is, the better the adhesiveness is.

(6) Film roll appearance: Visually observe the film roll obtained by continuously winding a certain length of vapor-deposited film. If the surface is flat and there are no wrinkles or thickening (rolling bumps),
Good rolled appearance), those with wrinkles or thickening are × (poor rolled appearance).
It was evaluated as follows.

(7) Slip property (sliding friction coefficient): △STMD189
4-63, the behavior of the non-deposited surface of the original film and the deposited film vJ11! Indicates the friction coefficient.

(8) Lay together the non-evaporated surfaces of a 2 cm x 7 α (width x length) sample over a length of 2 cm.
After being left at 40°C for 24 hours under a load of 250'J/ci, the force required for shearing the sample to peel off at a speed of 300 m/min was determined using a tensile tester. [Unit: (J/4cal]) The smaller this value is, the better the blocking resistance is.

[Example/Comparative example]

EXAMPLES Hereinafter, the present invention will be further explained in detail based on Examples and Comparative Examples, but the present invention is not limited by these Examples.

(Examples 1 to 4, Comparative Examples 1 to 4) (A) As resin for layer VFR7,011m163℃
1.00 parts of crystalline polypropylene was added with tetrakis[methylene-5-(3', 5') as an antioxidant.
-di-tert-butyl-4'hydroxyphenyl)
Propionate] 0.12 parts by weight of methane and (additional polymer for A1 layer (G- in Reference Example 1 below for Examples 1 to 3)-IDPE■ shown in Table 1, and as shown in Reference Example 2 for Example 4 G-HDPE ■) is added to each predetermined amount ω,
The mixture was mixed in a Henschel mixer and melt-extruded through an extruder to form pellets. In addition, (as a resin for Bl Fm, the copolymerization ratio of ethylene is 3.31%, the copolymerization ratio of butene-1 is 2.2% by weight, and the crystalline ethylene-propylene-butene-1 at 138°C) is used. Ternary copolymer 10
For each part of 0ffi&, the antioxidant o and io added to the layer (A) above are added, and to this, the first
Predetermined amounts of each of the additive polymers for layer (B) shown in the table were blended and pelletized in the same manner. Next, using two extruders and a two-layer T-die connected to them, the resin for (A) IT is extruded into one extruder using the combinations shown in Table 1. (B) Inject resin for footwear, melt extrude each at 220°C, laminate them in a molten state at the same temperature in a connected two-layer T-die, and rapidly cool the extruded film with a cooling roll at 30°C. Then, the (A) layer surface was subjected to corona discharge treatment and then rolled up, the thickness ratio of the (A)/(B) layer was 1:2, the total thickness was 30μ, and the wettability index of the treated surface was 41d.
Eight types of single-sided coextruded two-layer films of Vn/c were obtained. Next, set this film in a continuous vacuum evaporation device,
While continuously unrolling the film under a vacuum maintained at 10' Torr, aluminum vapor deposition was applied to the (A) layer surface of the film and the film was rolled up until the thickness of the vapor-deposited film was 380 mm (0,000 mm).
Eight types of single-sided aluminum vapor-deposited films of 0.04μ) were obtained.

The properties of the obtained vapor deposited film are also shown in Table 1.

As is clear from Table 1, Examples 1 to 4 having the structure of the present invention are excellent in all properties, and in particular, the adhesion, slip property, and blocking resistance of the deposited film are in the latter group, but compared to The film in the example is significantly inferior in one of the properties,
Moreover, many of them are inferior in other characteristics as well.

(Comparative Example 5) The pellet-shaped resin for (A) II used in Example 1 was melt-extruded at 220°C using an extruder with a diameter of 65 mm and a single-layer T die connected to the extruder, and then cooled at 30°C. It is rapidly cooled with a roll and formed into a film, then subjected to corona discharge treatment on one side and then rolled up to produce a single-sided treated flat single-layer film with a thickness of 30 μ, width 40 α, and wettability index of the treated surface of 41 dVn/a. Obtained. Next, this film was subjected to aluminum vapor deposition on the treated surface and wound up in the same manner as in Example 1, to obtain a single-sided aluminum vapor deposited film with a vapor deposited film thickness of 3808 (0,038 μm). The adhesion of this vapor-deposited film was 2209/15m.

The suitability for printing and laminating on the vapor-deposited surface is 39dVn/c! Although it had a good level of R and rank O, this vapor-deposited film was laminated with a stretched polypropylene film on the vapor-deposited side using a urethane adhesive, and the non-deposited sides were heat-sealed together using a bag-making machine to form a packaging bag. However, the sealing strength was extremely insufficient, the stretched film shrank and the shape of the bag collapsed, and a good bag could not be obtained, making it difficult to put it to practical use as a packaging bag.

(Comparative Example 6) The pelletized resin used for (B) shoes in Example 1 was molded into a film in the same manner as Comparative Example 5, and one side of the resin was coated with corona radiation.
After the treatment, the treated surface is similarly vapor-deposited with aluminum and rolled up. The thickness of the S deposited film is 400 (0.04
A single-sided aluminum vapor-deposited film of μ) was obtained. The adhesion of this vapor-deposited film is 120g/15#w+, the slip property is 0.85, and the blocking force is 660g/4d.
Overall, it was inadequate.

(Reference Example 1) Preparation of maleic anhydride grafted high-density polyethylene! ! l
(Manufacture of G-HDPE ■) Density 0.960. A modified high density polyethylene powder with Ml: 15.5 was heated to 130°C with maleic anhydride in the presence of xylene as a solvent and dicumyl peroxide as a radical initiator to graft copolymerize the maleic anhydride. Polyethylene was prepared.

The ratio between maleic anhydride grafts of this modified high-density polyethylene was 2.4% by weight. This modified^density polyethylene and the above-mentioned unmodified high-density polyethylene were mixed at a ratio of 1:1, and melt-kneaded using an extruder to obtain a pellet-shaped grafted high-density polyethylene.

(Reference Example 2) Preparation of maleic anhydride grafted high-density polyethylene (G
-Manufacture of HDPE■) Density 0.956, MI: 8.0 (7) To 100 parts by weight of high-density polyethylene powder, 0.5 parts by weight of maleic anhydride and 2,5-dimethyl 2,5-di(tertiary) -butylperoxy) was added with 0.01 part by weight of giraffe, mixed in a Henschel mixer, heated to 230°C using a co-directional twin screw extruder, and melt-kneaded.The strands were cooled and cut into pellets. Maleic anhydride grafted high density polyethylene was prepared.

〔Effect of the invention〕

The metallized film of the present invention has superior processability during vapor deposition compared to conventionally known metallized polypropylene films,
Since the M-deposited film is firmly adhered and there is no need to use fatty acid derivatives, the vapor-deposited surface has good suitability for printing and lamination, and the film also has excellent slip and blocking resistance. Productivity and workability such as multicolor printing, lamination with base films such as stretched polyester film and stretched polypropylene film, secondary processing such as automatic bag making, and increased speed and yield in each processing process. It is highly effective in improving bag making, automatic filling packaging, etc., and there is no deterioration of the deposited film during heat sealing, allowing for more effective use of its excellent bag tube properties, light shielding properties, gas barrier properties, etc. It can be used in a wide range of applications, including packaging for various foods and textile products, building materials, and various containers.

Claims (1)

[Scope of Claims] 1. A metal vapor-deposited film obtained by vapor-depositing a metal on layer (A) of a laminated film of two or more layers having the following layers (A) and (B) as surface layers. (A) Layer: Composition in which 0.3 to 30 parts by weight of grafted polyethylene obtained by graft polymerization of at least one selected from unsaturated carboxylic acids or derivatives thereof is blended with 100 parts by weight of crystalline polypropylene resin. A layer made up of things. (B) Layer: 1 part by weight of a crystalline polypropylene copolymer having a crystalline melting point 5°C or more lower than that of the crystalline polypropylene resin used in the (A) layer, and 1 part of high-density polyethylene having a density of 0.94 or more. A layer consisting of a composition containing ~10 parts by weight. 2. The grafted polyethylene used in the (A) layer has a maleic anhydride content of 0.01 to 2% by weight, obtained by graft polymerization of maleic anhydride, and an ethylene content of 80% by weight.
The density is 0.93 or more, and the amount added is 1 to 20
The metallized film according to claim 1, which is in parts by weight. 3. The crystalline polypropylene copolymer used for layer (B) contains 50% by weight or more of a propylene component, and is a copolymer of propylene with a crystal melting point of 150°C or less and ethylene or an α-olefin having 4 or more carbon atoms. The metallized film according to claim 1, which is a polymer. 4. Laminated film (B
) A package made by heat sealing the inner layers.