JPH11138721A - Laminate, and laminate forming resin or resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of manhours by lowering an extrusion temperature of resin to obtain a laminate which is excellent in bond strength without applying anchor coat treatment to a base material surface, improving odor and working atmosphere, and achieving safety by a method wherein a specific resin composition is used as an adhesion layer between the base material and a metallic thin layer. SOLUTION: An adhesion layer consisting of ethylene and α-olefin copolymer resin or a resin composition containing the copolymer resin is laminated on a surface, to which anchor coat is not applied, of a base material layer of a resin such as polyolefin resin of polyethylene, polypropylene, or the like, oxide of ethylene and vinyl acetate copolymer, or the like. Further, a laminate is formed by laminating a metallic layer of aluminum, copper, or the like, to which anchor coat treatment is not applied, onto the surface. Each bond strength between respective layers of the laminate is made at least 150 g/mm width. Thereby an extrusion temperature of the resin is made lower to make bond strength between the base material and the metallic thin layer excellent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a laminate having excellent adhesion to a base material layer and a thin metal layer, having low odor, and being economically advantageous, particularly useful for light packaging such as snack food packaging. The present invention relates to a resin or a resin composition for forming a body and a laminate.

[0002]

2. Description of the Related Art Conventionally, laminated films of various structures have been used as snack packages. As a laminating method for achieving an adhesive strength between layers in various structures of the laminated body to a practically possible level, The following and methods are known. . As a material of an adhesive layer between the various base material layers (A) subjected to anchor coating and the thin metal layer (C), a resin having a polar group introduced therein, such as ethylene / (meth) acrylic acid copolymer resin (EMA), is used. Extrusion lamination method
No. 25327). But,
The use of these copolymer resins involves the production cost or the complexity of exchanging the resin in the extruder, and the film odor peculiar to the copolymer resin and the odor such as residual solvent due to the anchor coat. It is not a preferred method from the viewpoint of

[0003] Good workability as a material for an adhesive layer for bonding the anchor-coated thin metal layer (C) and the thermoplastic resin layer (E), like the various base material layers (A) subjected to anchor coating. A method of extruding a low-density polyethylene resin with a high extrusion resin temperature of, for example, 320 ° C. or higher, and oxidizing the surface of the resin in an air gap between a die and a pressure roll and bonding the resin is reported. (“Convertec”, Vol. 8, p. 36, published in 1991). However, these require an anchor coating treatment of at least two to three steps in order to increase the adhesive strength, and such an anchor coating treatment is not preferable from the viewpoint of production cost and the residual solvent odor due to the anchor coating. .

[0004]

Therefore, it is possible to improve the adhesion to a thin metal layer which has not been subjected to an anchor coating treatment, to improve the working environment and to reduce the number of steps in production by reducing the odor. It is an object of the present invention to provide a laminate and a resin or resin composition for forming a laminate, which is economically advantageous and is particularly useful for light packaging such as snack food packaging.

[0005]

Means for Solving the Problems The present inventor has conducted intensive studies in view of the above problems, and as a result, as an adhesive layer (B) between the substrate (A) and the thin metal layer (C). , Ethylene-α-
By using a resin composition containing an olefin copolymer resin, the extrusion temperature of the resin is lower than before, and a laminate having excellent adhesive strength can be obtained without performing an anchor coat treatment on the substrate surface, and a low odor, The present invention has been completed based on the finding that the working environment can be improved and safety can be achieved, and the number of steps during manufacturing can be reduced. That is,
The laminate of the present invention is formed by bonding an ethylene / α-olefin copolymer resin or a resin composition containing the copolymer resin to the surface of a substrate layer (layer A) that has not been subjected to an anchor coat treatment. Layer (Layer B), and a thin metal layer (Layer C) that has not been subjected to anchor coating on the surface of the adhesive layer (Layer B). The adhesive strength is 150 g / 15 mm width or more. Further, the resin or resin composition for forming a laminate, which is another invention of the present invention, comprises a base material layer (A
In a resin or a resin composition for forming a laminate, a thin metal layer (C layer) that has not been subjected to an anchor coat treatment via an adhesive layer (B layer) is laminated on the surface of the adhesive layer (B layer).
The material of the layer) has an MFR of 1 to 100 g / 10 min, a density of 0.900 g / cm ³ or less, and a relation between the extrapolative melting end temperature (Tem) of the melting peak and the density (D) is represented by the following equation. Or a resin composition containing the copolymer resin. Tem ≦ 286D-137

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION [I] Laminate (1) Layer Structure The layer structure of the laminate of the present invention is as follows. Basically composed of an adhesive layer (layer B) made of a polymer resin or a resin composition containing the copolymer resin, and a thin metal layer (layer C) that has not been subjected to anchor coating treatment. is there.

(A) Base Layer (Layer A) The material used as the base layer (Layer A) that has not been subjected to the anchor coat treatment and that constitutes the laminate of the present invention is a polyolefin resin such as polyethylene or polypropylene. Saponified ethylene-vinyl acetate copolymer, polystyrene resin, polyester resin such as polyethylene terephthalate (PET), polyamide resin such as stretched nylon film (ONY), polyvinyl alcohol resin, polyvinyl chloride resin, polyvinylidene chloride resin, etc. Examples include unstretched or uniaxially or biaxially stretched films or sheets of synthetic resin, woven or nonwoven fabric, paper, cellophane, and the like. Among these, polyethylene terephthalate (PE
T) and other stretched polyester and nylon films (ON
It is preferable to use a polyamide resin such as Y) or a stretched polypropylene film (OPP). It is preferable that the surface is subjected to a corona treatment, a flame treatment, and an ozone treatment as necessary. The ozone treatment is performed by directing a gas (air or the like) containing ozone from a nozzle or a slit-shaped outlet in an air gap to the surface of the adhesive layer or the surface of the metal thin film layer or the base material laminated thereon, or a crimping portion of both. It is done by spraying toward. In addition, 100m
When performing extrusion lamination at a speed of / min or more,
It is preferable to spray toward the pressure-bonded portion between the molten thin film and the substrate. The concentration of ozone in the gas to be sprayed is preferably 1 g / m ³ or more, more preferably 3 g / m ³ or more.
Further, the spray amount is preferably at least 0.03 liter / min / cm, more preferably at least 0.1 liter / min / cm, with respect to the width of the adhesive layer.

(B) An adhesive layer (layer B) composed of an ethylene / α-olefin copolymer resin or a resin composition containing the copolymer resin (ethylene / α-olefin copolymer) constituting the laminate of the present invention The material used as the adhesive layer (B layer) composed of the resin composition containing the coalesced resin or the copolymer resin is a resin for forming a laminate composed of a copolymer resin of ethylene and α-olefin, or It is a resin composition containing a copolymer resin.

(A) Resin for forming a laminate The resin for forming a laminate is a copolymer resin of ethylene and an α-olefin, preferably ethylene and a C3 to C10 resin.
(Preferably 4 to 8) α-olefins having a molecular skeleton, specifically, ethylene and butene-1, hexene-1, octene-1, 4-methylpentene- It is a copolymer resin obtained from a mixture with one or more α-olefins such as 1.

An ethylene / α-olefin copolymer resin
Production Such an ethylene / α-olefin copolymer resin is preferably produced using a metallocene catalyst shown below. Examples of the resin produced using a metallocene catalyst include JP-A-58-19309 and JP-A-59-9529.
No. 2, JP-A-60-35005, JP-A-60-350
No. 06, JP-A-60-35007, JP-A-60-35
008, JP-A-60-35009, JP-A-61-1
No. 30314, Japanese Patent Application Laid-Open No. Hei 3-163088, European Patent Application Publication No. 420,436, U.S. Pat. No. 5,055,438, and International Patent Publication WO 91/04257. The described method, ie a metallocene catalyst, a metallocene / alumoxane catalyst, or, for example, WO 92/07
Copolymerization of ethylene as a main component and α-olefin as a subcomponent using a catalyst comprising a metallocene compound and a compound which reacts with a metallocene catalyst to form a stable ion as disclosed in, for example, US Pat. It was manufactured by

(B) Laminate-forming resin composition The laminate-forming resin composition is obtained by adding the above-mentioned copolymer resin of ethylene and α-olefin to a polyolefin resin such as polyethylene, polypropylene, polybutene, and ethylene / acetic acid. Good compatibility resin such as vinyl copolymer, ethylene / (meth) acrylic acid copolymer, ethylene / (meth) acrylate copolymer and other ethylene / vinyl copolymer, slip agent, antistatic Agents, anti-fog agents, ultraviolet absorbers, various additives such as antioxidants, and various inorganic fillers such as calcium carbonate, silica, titanium oxide, talc, and
It is a resin composition containing a pigment and the like. The ethylene / α-olefin copolymer resin contained in the resin composition,
The content is at least 20% by weight, preferably 30 to 100% by weight, particularly preferably 40 to 80% by weight. Further, it is preferable that the copolymer resin or the resin composition containing the copolymer resin has the following MFR and / or density.

MFR The copolymer resin of ethylene and α-olefin or a resin composition containing the copolymer resin is JIS-K72
Those having an MFR (melt flow rate: melting flow rate) of 1 to 100 g / 10 min, preferably 3 to 50 g / 10 min are used. If the MFR is less than the above range, the adhesive strength between the layers becomes small, and the spreadability of the resin is lost. On the other hand, if the MFR exceeds the above range, the neck-in becomes large, and in any case, a uniform molten thin film cannot be obtained.

[0013] The resin composition containing a density above copolymer resin or a copolymer resin, the density according JIS-K7112 (D) is 0.900 g / cm ³ or less, preferably 0.890 g /
What shows cm ³ or less is used. If the density exceeds the above range, the adhesive strength between the layers becomes small, and practical strength in the case of a package cannot be obtained.

Melting by Differential Scanning Calorimetry (DSC)
Peak extrapolation melting end temperature (Tem) The ethylene / α-olefin copolymer resin used in the present invention is a DS measured according to JIS-7121.
Extrapolated melting end temperature (T
em) and the density (D) are such that Tem ≦ 286D−1
37, preferably Tem ≦ 349D-197, most preferably Tem ≦ 429D-271.

(C) Thin Metal Layer (C Layer) The material used as the thin metal layer (C layer) of the laminate of the present invention that has not been subjected to the anchor coating treatment is aluminum, copper, silver or the like. Vacuum evaporation method, sputtering method, ion beam on the surface of a metal foil of 5 to 50 μm or the surface of a base material such as a thermoplastic resin film such as polyethylene, polypropylene, polyethylene terephthalate, polyamide, polystyrene, polycarbonate, polyvinyl chloride or paper, or paper. The thickness is 0.01 to 0.2 by a known evaporation method such as a method.
A film on which a vapor deposition film of the above metal is formed to a thickness of about μm is used. The surface is subjected to corona treatment and ozone treatment as needed.

(D) An adhesive layer (B ′ layer) made of an ethylene / α-olefin copolymer resin or a resin composition containing the copolymer resin, which is laminated as necessary in the laminate of the present invention. The material used as the adhesive layer (B ′ layer) composed of the ethylene / α-olefin copolymer resin or the resin composition containing the copolymer resin is the ethylene / α-olefin copolymer resin of the B layer. Alternatively, the same ethylene / α-olefin copolymer resin as the adhesive layer made of the resin composition containing the copolymer resin or the resin composition containing the copolymer resin can be used. However, they need not necessarily be of the same species.

(E) Thermoplastic resin layer (E layer) In the laminate of the present invention, a thermoplastic resin layer (E
The material used as the layer) is not particularly limited, but it is preferable to use a resin suitable for heat sealing such as polyethylene and polypropylene. Further, the surface may be subjected to corona treatment and ozone treatment as necessary.

(2) Thickness The thickness of the substrate layer (A layer) is generally 7 to 200 μm,
Preferably 7 to 50 μm, particularly preferably 10 to 30 μm
m. The thickness of the adhesive layer (layer B) composed of the ethylene / α-olefin copolymer resin or the resin composition containing the copolymer resin is generally 5 to 100 μm, preferably 10 to 50 μm, and particularly preferably. Is 10-20μ
m. Further, the thickness of the thin metal layer (C layer) is generally 5 to 100 μm, preferably 5 to 50 μm, and particularly preferably 5 to 30 μm. The thickness of the adhesive layer (B ′ layer) composed of the ethylene / α-olefin copolymer resin or the resin composition containing the copolymer resin laminated as necessary is preferably 10 to 50 μm, and particularly preferably. Is 10
２０20 μm. In addition, the thickness of the thermoplastic resin layer (E layer) similarly laminated as necessary is preferably 10 to
It is 100 μm, particularly preferably 10 to 50 μm.

(3) Adhesive strength The laminate of the present invention contains a base layer (A layer) not subjected to anchor coating treatment, and an ethylene / α-olefin copolymer resin or the copolymer resin. In a laminate composed of an adhesive layer (layer B) made of a resin composition and a thin metal layer (layer C) that has not been subjected to anchor coating treatment, the adhesive strength between the layers is 150 g / 15 mm width or more, preferably 2 or more.
It is not less than 00 g / 15 mm width.

[II] Applications The laminate of the present invention and the resin or resin composition for forming a laminate constituting the laminate are used as a constituent layer of the laminate as a base layer not subjected to an anchor coat treatment. Despite the use of the (A layer) and the thin metal layer (C layer) that has not been subjected to anchor coating, it has excellent adhesion to the base material layer and the thin metal layer, has low odor, and is economical. Advantageous, snack food packaging and
A resin or resin composition for forming a laminate, which is useful for packaging water products such as pickles, especially for light packaging such as snack food packaging. In particular, an adhesive layer (B) made of an ethylene / α-olefin copolymer resin or a resin composition containing the copolymer resin is further formed on the surface of the thin metal layer (C layer) not subjected to the anchor coat treatment. 'Layer) and thermoplastic resin layer (E layer)
The laminate comprising A layer / B layer / C layer / B 'layer / E layer obtained by laminating is excellent in heat sealability and extremely useful for light packaging such as snack food packaging.

[0021]

The present invention will be described more specifically with reference to the following examples and comparative examples. [I] Evaluation method (1) Measurement method of physical properties (A) MFR: in accordance with JIS-K7210 (190 ° C,
(2.16 kg load) (B) Density: conforms to JIS-K7112 (C) Extrapolated melting end temperature (Tem) by differential scanning calorimetry (DSC): 100 μm molded by hot press
About 5 mg of a sample was weighed from the film of Example 1 and set on a DSC device (RDC 220) manufactured by Seiko Denshi Kogyo Co., Ltd., the temperature was raised to 170 ° C., and the temperature was maintained for 5 minutes. Cool to -10 ° C at ° C / min. After holding for 1 minute in that state, the temperature was raised at a rate of 10 ° C./min for 1
The temperature was raised to a temperature of 70 ° C. for the measurement. And-
A DSC curve when the temperature was raised from 10 ° C to 170 ° C was obtained. Next, in accordance with JIS-K7121, the temperature at the intersection of a line obtained by extending the baseline on the high-temperature side of the DSC curve to the low-temperature side and a tangent drawn at the point where the gradient becomes maximum on the high-temperature side curve of the melting peak is calculated. The extrapolated melting end temperature (Tem) was used.

(2) Evaluation method of laminated body (A) Manufacturing process: A process in which a single laminator (one AC coating) manufactured by Nippon Polychem Co., Ltd. is used to manufacture the structure of each example and comparative example. Indicates a number. (B) Adhesive strength: A test piece having a width of 15 mm and a length of 100 mm was cut out from the laminate along the flow direction of molding. A part of each layer of the test piece was forcibly peeled off at 23 ° C.
After conditioning at 50% relative humidity, pulling speed 300m
The film was peeled at 180 m / min and the adhesive strength was measured. (C) Odor: about 0.5 m ^{2 of} each laminate was 10 mm × 10 mm
The sample, which had been considerably finely chopped, was placed in a jar, left in an oven at 40 ° C. for 2 hours, taken out, and evaluated for odor. ：: Almost no smell. Δ: Slightly smelling. X: Strong smell.

[II] Examples and Comparative Examples Example 1 A biaxially oriented polypropylene film base material (OPP: A layer) having a thickness of 20 μm was subjected to a corona treatment and a thickness of 12 μm.
between the aluminum-deposited surface of a biaxially stretched polyester film (VMPET: C layer) with a thickness of μm, a) Component: ethylene / butene-1 copolymer resin (E / B copolymer: metallocene catalyst) (MFR is 32 g / 10 min, density is 0.88 g / cm ³ , butene content is 23% by weight) 80% by weight and b) component: low-density polyethylene resin (LDPE manufactured by Nippon Polychem Co., Ltd.): LC600A, MFR: 7 g / 10 min, density: 0.919 g / cm ³ ) A resin composition (layer B) composed of 20% by weight was coated with a single laminator having a diameter of 90 mm (anchor treatment (AC) device is provided in one place). The resin temperature is 290 ° C from the T die attached to the extruder.
Then, the mixture was extruded into a film having a width of 550 mm and subjected to sandwich lamination to obtain a laminate (layer A / layer B / layer C = OPP / PE resin composition / VMPET). The air gap during this lamination was 120 mm, the lamination speed was 100 m / min, and the thickness of the lamination layer was 12 μm.
m. At this time, the base material (A layer) and the resin composition (B layer)
The ozone treatment (O ₃ treatment) was performed between the resin composition (layer B) and the aluminum-deposited surface (layer C) of the aluminum-deposited polyester film. And then,
Polyester film on the non-laminated side (C
Layer) surface (this surface is a corona-treated surface) and a corona-treated surface of an unstretched polypropylene film (CPP: E layer) having a thickness of 25 μm, a resin composition comprising components a) and b) as described above. (B ′ layer) was subjected to sandwich lamination under the same conditions as described above. Also at this time, the ozone treatment was applied to the area between the polyester film and the resin composition (C layer / B layer) and the corona-treated surface (B ′ layer / E layer) of the resin composition and the unstretched polypropylene film (CPP). Was performed. The obtained laminate was evaluated, and the results are shown in Table 1.

Comparative Example 1 The resin composition comprising the components a) and b) used in Example 1 above was changed to 100% by weight of the low density polyethylene resin (LC600A manufactured by Nippon Polychem Co., Ltd.) of the component b). Further, the resin temperature was changed from 290 ° C. to 320 ° C., and further, a biaxially stretched polypropylene film (A layer)
, The corona-treated surface of a biaxially oriented polyester film (C layer) on which aluminum is deposited, and the corona-treated surface of a non-oriented polypropylene film (E layer), all of which are polybutadiene-based anchor coating agents (Nippon Soda ( stock)
Production: Titabond T-180) A solution was applied, and the same procedure as in Example 1 was carried out except that the ozone treatment was not performed, to obtain a laminate. The obtained laminate was evaluated, and the results are shown in Table 1.

Example 2 A corona-treated surface of a biaxially stretched polypropylene film substrate having a thickness of 20 μm (layer A) and a non-stretched aluminum film having a thickness of 25 μm (layer C)
A) Component: Ethylene / butene-1 copolymer resin (Material produced by metallocene catalyst: MFR: 32 g / 10 min, density: 0.88 g / cm ³ , butene content: 23) 80% by weight) and b) Component: Low-density polyethylene resin (LC600A, manufactured by Nippon Polychem Co., Ltd., MFR: 7 g / 10 min, density: 0.919 g / cm ³ ) Extruded at a resin temperature of 200 ° C. and a width of 550 mm from a T-die mounted on a 90 mm extruder,
Sandwich laminated. At this time, the air gap was 120 mm, the laminating speed was 100 m / min, and the thickness of the laminated layer was 12 μm. At this time, the base material (A
The ozone treatment was performed between the layer (layer B) and the resin (layer B) and between the resin (layer B) and the aluminum-deposited surface of the vapor-deposited polyester film (layer C). The obtained laminate is evaluated,
Table 1 shows the results.

Comparative Example 2 A resin composition comprising the components a) and b) used in Example 2 was used as an ethylene-acrylic acid copolymer resin (XD422V, manufactured by Nippon Polychem Co., Ltd., MFR: 28).
g / 10 min, acrylic acid content 8% by weight), and further, a polybutadiene-based anchor coating agent (manufactured by Nippon Soda Co., Ltd .: Titabond T-180) solution on the corona-treated surface of the biaxially stretched polypropylene film as the base material. And a laminate was obtained in the same manner as in Example 1 except that ozone treatment was not performed.

The obtained laminate was evaluated, and the results are shown in Table 1.

[0028]

[Table 1] OPP: Biaxially oriented polypropylene film, CPP: Non-oriented polypropylene film, Corona: Corona treatment, AC: Anchor coat treatment, Corona-AC: Corona treatment-anchor coat treatment, E / B copolymer: Ethylene / butene-1 copolymer Polymer, E / H copolymer: ethylene / hexene-1 copolymer, E / AA copolymer: ethylene / acrylic acid copolymer, AA: acrylic acid, EAA: ethylene / acrylic acid copolymer VMPET: Aluminum-deposited polyethylene terephthalate, VMCPP: Aluminum-deposited unstretched polypropylene film, * 1: PE deterioration odor and solvent odor, * 2: AA odor and solvent odor,

[0029]

The packaging laminate of the present invention and the resin composition for forming a laminate according to the present invention comprise a base material (A) and a thin metal layer (C).
By using a resin composition (B) containing an ethylene / α-olefin copolymer resin as an adhesive layer between the resin and the resin, the extrusion temperature of the resin can be lowered than before, and further, an anchor coat treatment can be performed on the substrate surface. Even without applying, and without using a special material that is not sufficient in odor and purging properties, a laminate excellent in adhesive strength between the base material (A) and the thin metal layer (C) can be obtained. Since the odor, the working environment and the safety can be improved and the number of steps in the production can be reduced, an economically advantageous laminate for packaging and a resin composition for forming a laminate can be obtained.

Claims (6)

[Claims] 1. An adhesive layer comprising an ethylene / α-olefin copolymer resin or a resin composition containing the copolymer resin on a surface of a substrate layer (layer A) which has not been subjected to anchor coating treatment. B layer), and further, the adhesive layer (B layer)
A laminate in which a thin metal layer (C layer) not subjected to an anchor coat treatment is laminated on the surface of the laminate, wherein the adhesive strength between each layer of the laminate is 150 g / 15 mm width or more. . 2. An adhesive comprising an ethylene / α-olefin copolymer resin or a resin composition containing the copolymer resin on the surface of the thin metal layer (C layer) not subjected to the anchor coating treatment. Layer (B ′ layer), and the adhesive layer (B ′)
Layer A in which a thermoplastic resin layer (layer E) is laminated on the surface of layer A)
A laminate comprising layer B / layer C / layer B '/ layer E, wherein the adhesive strength between the layers of the laminate is 150 g / 15 m, respectively.
The laminate according to claim 1, having a width of at least m. 3. The adhesive layers (B layer) and (B ′ layer) have an MFR of 1 to 100 g / 10 min, a density of 0.900 g / cm ³ or less, and an extrapolated melting end temperature (Tem) of a melting peak. The relationship between the density (D) and ethylene / α-
3. An olefin copolymer resin or a resin composition containing the copolymer resin.
The laminate according to item 1. Tem ≦ 286D-137 4. The laminate according to claim 1, wherein the laminate is a packaging laminate.
4. The laminate according to any one of items 3 to 3. 5. A thin metal layer (C layer) not subjected to an anchor coating treatment is laminated via an adhesive layer (B layer) on the surface of a substrate layer (A layer) not subjected to an anchor coating treatment. In the resin or resin composition for forming a laminate, the material of the adhesive layer (B layer) has an MFR of 1 to 100 g / 10 min, a density of 0.900 g / cm ³ or less, and an extrapolation melting end temperature of a melting peak. The relationship between (Tem) and the density (D) is an ethylene / α-olefin copolymer resin or a resin composition containing the copolymer resin satisfying the following relationship: Resin or resin composition. Tem ≦ 286D-137 6. A layer / layer obtained by further laminating a thermoplastic resin layer (E layer) via an adhesive layer (B 'layer) on the surface of a thin metal layer (C layer) not subjected to anchor coating treatment. In a laminate-forming resin or a resin composition for forming a laminate consisting of layer B / layer C / layer B '/ layer E, the adhesive layer (B'
The material of the layer) has an MFR of 1 to 100 g / 10 min, a density of 0.900 g / cm ³ or less, and a relation between the extrapolative melting end temperature (Tem) of the melting peak and the density (D) is represented by the following equation. The resin or resin composition for forming a laminate according to claim 5, which is an ethylene / α-olefin copolymer resin or a resin composition containing the copolymer resin. Tem ≦ 286D-137