JPS59109357A - Laminate for easily exfoliative packing material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an easily peelable laminate for packaging materials comprising a metal layer, a resin composition layer having easy peelability, and an adhesive layer for firmly adhering the resin composition layer to the metal. Regarding the body.

Conventionally, various surface treatments such as corona discharge treatment, surface oxidation such as chromic acid treatment, and etching have been applied to metals in order to increase the adhesive strength between metals and easily peelable resin compositions. I haven't found anything satisfying.

On the other hand, a method using an anchor coating agent has also been considered, and a two-component type isocyanate-based anchor coating agent consisting of a base agent and a curing agent is generally used.

However, the above anchor coating agent uses polyethylene (
Although the adhesion with the resin composition (hereinafter referred to as PR) is satisfactory, the adhesion with the easily peelable resin composition is completely insufficient. Furthermore, since it is a two-component type, it is complicated to use, has restrictions on pot life, and has drawbacks such as insufficient laminate strength unless it is aged (heated and cured).

The present inventors have improved these conventional drawbacks and have conducted extensive research into adhesives that firmly bond metals and easily peelable resin compositions. Or, the graft copolymer obtained by reacting the anhydride thereof is dissolved in various organic solvents, and a graft copolymer that is stable at room temperature (
It has been found that the adhesive composition (hereinafter referred to as the adhesive composition) has strong adhesive strength to both metals and easily peelable resin compositions, has excellent workability, and does not require aging.

Examples of metals used in the present invention include aluminum, iron, tin, nickel, copper, lead, and zinc.

The ethylene content of the ethylene-butene-1 copolymer of the adhesive composition described above is 40 to 85 mol%, preferably 55 to 85 mol%.

In addition, examples of unsaturated carboxylic acids or anhydrides thereof to be graft-polymerized to the ethylene-butene-1 copolymer include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, citraconic anhydride, and itaconic anhydride. Examples include acids. Among these, it is most preferable to use maleic anhydride.

The method of grafting ethylene-butene-1 copolymer and unsaturated carboxylic acid or its anhydride is as follows: 1. Various known methods can be employed. For example, this can be carried out by adding a radical generator to both in the presence or absence of a solvent and heating the mixture at a high temperature. ethylene-butene-
1 The amount of graft monomer grafted in the copolymer is 0.
．． 01 to 5% by weight, preferably 0.05 to 2% by weight
It is. The above adhesive composition is a composition dissolved in a solvent such as an aromatic hydrocarbon or an aliphatic hydrocarbon such as toluene, xylene, heptane, or octane, and is stable at room temperature.

Next, the easily peelable resin composition will be described below.

The easily peelable resin composition used in the present invention is composed of an ethylene-vinyl acetate copolymer (hereinafter referred to as EVA) or an ethylene-acrylic acid ester copolymer, which is appropriately selected from the following groups A to A. The main component is a polymer (hereinafter referred to as EEA) or PE.

A) EVA (vinyl acetate content 5-35% by weight)
EEA (acrylic acid content 6-25% weight V
Acid modified product of A B) PE (low density PE, medium density PE, high density PE, linear low density PE) C) Ethylene-propylene copolymer, ethylene-butene-1 copolymer, acid polypropylene, isopropylene Tactical polypropylene, acid modified product of PP D) Rosin,
The mixing ratio of each group of rosin modified product, terpene resin, terpene modified resin, aliphatic hydrocarbon resin, aromatic hydrocarbon resin, and alicyclic hydrocarbon resin is 20 to 95% by weight of group A, 10% by weight of group A
60% by weight, Group C O to 30% by weight, Group D O to 3
It can be selected from 0% by weight.

The laminate according to the present invention is obtained by applying the adhesive composition to a metal such as aluminum foil using a gravure printing machine, a coating device of a dry laminator, an anchor coating agent coating device of an extrusion laminator, a general lacquer coater, etc. The thickness is 0.001 to 1μ, preferably 0.001μ to 1μ, preferably 0.001 to 1μ by a conventionally known method such as gravure coating method, roll coating method, air knife coating method, or dipping method.
．． It can be easily obtained by applying the resin composition to a thickness of 0.5 to 0.2 μm and then extruding and laminating the easily peelable resin composition. The laminate of the present invention can be laminated by extruding the easily peelable resin composition immediately after applying the adhesive composition to the metal layer (in-line method), or by laminating only the easily peelable resin composition later. (offline method).

The laminate of the present invention has a metal and an easily peelable resin composition that are firmly adhered to each other, and the adhesive composition that adheres the two is stable at room temperature. Since it is a liquid type, it has excellent workability without restrictions on bot life, and has equivalent characteristics that do not require aging.

Furthermore, the lid body molded from the laminate of the present invention can be made of polypropylene (hereinafter referred to as PP), polyvinyl chloride (hereinafter referred to as
By thermo-compression bonding with a plastic container such as PvC, polystyrene (hereinafter referred to as Ps), or a container body molded from a composite laminate with these as the surface layer, it maintains hermeticity and is easily opened when the lid is opened. It is suitable as a laminate for easily peelable packaging materials that can be opened. Of course, it is equally suitable for use in bags.

Next, examples and comparative examples will be shown.

<Example-1> Maleic anhydride o, a weight i% and ethylene-butene-
The reaction product with 99.7% by weight of 1 copolymer was mixed with toluene and
A 2.5% solution was prepared with a mixed solvent of n-hebutane, and the resulting composition was used as an anchor coating agent for extrusion lamination.

0.2 g/% of the above adhesive composition was applied to aluminum foil (30μ) using an anchor coating agent applicator of an extrusion laminator (diameter 401mφ), and an easily peelable resin composition having the following composition was applied on top of it to a thickness of 25μ. A laminate was prepared by extrusion coating, and the lamination strength between the aluminum foil and the easily peelable resin composition layer of this laminate and the peel strength between the easily peelable resin composition layer and the PP, PVC, and PS sheets were measured. . The results are shown in Table-1.

[Mixing ratio of easily peelable resin composition]

E VA (NUC3190; manufactured by Nippon Unicar rn)
60 weight 9% V/': 25 weight %, MI:
10 g/10 min PE (Sumikasen L-405, manufactured by Sumitomo Chemical ■) 10% by weight MI: 3.7 g/10 min Ethylene-α olefin copolymer resin (Tafmer P-0180, manufactured by Mitsui Petrochemical Industries) 10
Weight % MI: 4.5 g/10 min Alicyclic hydrocarbon resin [Alcon P-90; manufactured by Arakawa Chemical Industry ■] 2
0% by weight softening point (ring and ball method): 90°C <Example-2> Same as Example-1 except that the following easily peelable resin composition was used instead of the easily peelable resin composition of Example-1. I went to

The results are shown in Table-1.

(Mixing ratio of easily peelable resin composition) PE (Betrocene 350; manufactured by Toyo Soda Kogyo@) 60
Weight % MI: 15g/10min EVA (Sumitate IIA-20i Sumitomo Chemical @
[Manufactured] 20 heavy nails%VA: 20% by weight, MI: 20g/L
Q-part alicyclic hydrocarbon resin [Alcon P-90; manufactured by Arakawa Chemical Industry Al] 2
0% by weight softening point (ring and ball method): 90°C <Example-3> Example-1 except that an easily-peelable resin composition having the following composition was used instead of the easily-peelable resin composition of Example-1. I did the same thing. The results are shown in Table-1.

[Mixing ratio of easily peelable resin composition]

EEA (manufactured by NUC6169i Nippon Unicar)
70% by weight EA: 1B% by weight, MI: 6g/10min PE (Sumikasen L-405; manufactured by Sumikasen Chemical Ql)
10 weight MT: 3.7 g/10 minutes Alicyclic hydrocarbon resin [Alcon P-90i manufactured by Arayo Kagaku Kogyo@] 20
Permanent softening point (ring and ball method): 90°C The same procedure was carried out except that the imine thread anchor coating agent CEP Brimer 108; Dainippon Ink & Chemicals (manufactured by 11) was used instead of the adhesive composition of Example = 1. The results are shown in Table-1.

Comparative Example-2 The same procedure was carried out except that an isocyanate-based anchor coating agent (LX-1015; manufactured by Dainippon Ink and Chemicals) was used instead of the adhesive composition of Example-1.The results are shown below. -1.

<Comparative Example-3> Instead of the adhesive composition of Example-1, a salt-vinyl acetate copolymer anchor coating agent [Dick Seal A-200B] was used.
, manufactured by Dainippon Ink & Chemicals, Ltd.] was used. The results are shown in Table-1.

<Comparative Example-4> Same procedure except that a salt-vinyl acetate adhesive composition [Dick Seal A-200B; manufactured by Dainippon Ink & Chemicals @] was used instead of the easily peelable resin composition of Example-2. went. The results are shown in Table-1.

<Comparative Example-5> After applying the anchor coating agent of Example-1 at 0.2 g/rrr to aluminum foil (30μ), each film of polyester, polyamide, vinyl chloride, and polystyrene was adhered, and its adhesive strength was evaluated. I tested it, but it didn't stick at all.

Table 1 Note-1) Extrusion lamination temperature 230℃ Peeling angle
90°/180° peeling heat seal conditions Pressure crab 1kg/cJ, time:
1 second peel angle 180° peel

[Brief explanation of the drawing]

The figure shows a cross section of the laminate of the present invention, where 1 is a metal layer, 2 is an adhesive layer, and 3 is an easily peelable resin layer. Patent Applicant: Dainippon Ink & Chemicals Co., Ltd. 1, Indication of the Case, Japanese Patent Application No. 57-219271 2, Name of the Invention, Easily Peelable Laminate for Packaging Materials 3, Person Making Amendment Relationship with the Case: Patent Applicant: 174 3-35-58 Sakashita, Itabashi-ku, Tokyo (28
8) Dainippon Ink & Chemicals Co., Ltd. Representative Yo Mura
Kuni Shigeru 4, Agent Address: 3-7-20 Nihonbashi, Chuo-ku, Tokyo 103 Dainippon Ink & Chemicals Co., Ltd. Column 6 of "Detailed Description of the Invention" in the Specification, Contents of M

Claims (1)

[Claims] A metal layer 1, an adhesive layer 2 of a graft copolymer obtained by reacting an ethylene-butene-1 copolymer with an unsaturated carboxylic acid or its anhydride, and an ethylene-vinyl acetate copolymer or an ethylene-acrylic copolymer. An easily peelable laminate for packaging material comprising a composition layer 3 containing an acid ester copolymer or polyethylene as a main component.