JPS61141551A - Dry laminating method - 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 A. Field of Industrial Application The present invention relates to a dry lamination method for laminating and bonding thin layer materials such as plastics, paper, metals, etc. The adhesive strength has been improved by improving the conditions for applying the adhesive.

Conventional technology The conventional dry lamination method involves uniformly applying an aqueous or organic solvent adhesive solution to one side of the thin layer materials to be laminated, and then drying by evaporating the solvent in a drying oven. In the adhesive state, this side is overlaid with another thin layer of material, typically 40
A pressure of 1 is applied between a metal roll and a rubber roll heated to ~100℃.
10 m, and then brought into contact with a cooling roll for cooling, followed by a winding process.

Since this dry lamination method allows for efficient lamination and bonding, it is used as a means for laminating many thin-layer materials, and is particularly used in the production of packaging materials and industrial materials.

Problems to be Solved by the Invention In the conventional dry laminating method described above, the adhesive solution has a relatively high concentration in order to quickly dry the coating film and to obtain a sufficiently thick coating layer.

High viscosity adhesives are used, but this tends to prevent the adhesive solution from being applied sufficiently to the surface of the thin layer material, especially when the adhesive solution is laminated to the surface where the coating has become dry and tacky. Even if the surface of the layer material is answered correctly, the adhesive will not be sufficiently wetted and the adhesive strength will be insufficient, resulting in the problem that peeling will easily occur when external forces such as bending and tension are applied to the surface of the layer material.

29 Means for Solving Problems The present invention solves the above-mentioned problem of insufficient lamination adhesive strength by the following means. In other words, when carrying out the dry lamination method of thin-layer materials, the present invention involves applying a low concentration, low viscosity adhesive solution containing a larger amount of solvent than usual to each laminated surface in advance and drying it to form a primary adhesive layer. After that, apply an ordinary high-concentration, high-viscosity adhesive solution of the same type as the above-mentioned adhesive solution, but with a small amount of solvent, on one or both sides of the primary adhesive layer to be layered. It is characterized by coating and drying to form a secondary adhesive layer, and then laminating and press-bonding.

According to the above method, each secondary adhesive layer is formed on the surface of the thin layer material in a sufficiently wet and strong adhesive state, and furthermore, the secondary adhesive layer formed on this surface is also of the same type and is therefore sufficiently bonded. Adhesive strength can be obtained. The secondary adhesive layer is usually formed on one side of the primary adhesive layer, but if it is particularly desired to increase the thickness of the adhesive layer, it may be formed on both primary adhesive layers.

In order to explain the dry laminating method of the present invention in more detail, we will explain the case using the laminating apparatus shown in the figure).

The thin layer material A unwound from the winding roll 1 is coated with a low concentration, low viscosity adhesive solution in a coating unit 2. The coating amount may be about 0.01 to 0.5 a/i (solid content). This is dried in a drying zone 3 to form a primary adhesive layer, and then in a coating unit 4 an adhesive solution of the same type as the above-mentioned adhesive solution but with a higher concentration and higher viscosity is applied, for example, to .5~5. OQ /
A secondary adhesive layer is formed by coating the adhesive in a solid amount and drying it in the drying zone 5. On the other hand, the thin layer material B is fed out from the winding roll 6, and the same low SIf and low viscosity adhesive solution as described above is applied in the coating unit 7 to o, 01 to 0.
．． Approximately 5 g/g (solid content) is applied and dried in drying zone 8 to form a primary adhesive layer.

Then, the secondary adhesive layer surface of the thin layer material A and the primary adhesive layer surface of the thin layer material B are brought into contact with each other, and the material is introduced into a pressure bonding roll 9 consisting of a heated metal roll and a rubber roll for lamination and pressure bonding, and then a cooling roll is applied. 1o to cool it and wind it up as a laminate product 11.

IJi above! Materials A and B are usually dry-laminated films, sheets, foils, etc., such as polyester, nylon, polyethylene, a copolymer of ethylene, vinyl acetate, acrylic acid or methacrylic acid, or unsaturated monomers such as esters thereof. Stretched or unstretched films of polymers, polypropylene, polybutene-1, ionomers, polybutadiene, polycarbonate, saponified ethylene and vinyl acetate copolymers, cellulose derivatives (cellophane), polyvinyl chloride, polyvinyl chloride, polyvinylidene chloride, etc. Metal foils such as sheets, aluminum, copper, iron, etc. are used, and thin layer materials usually have relatively high strength, while thin layer material B has low strength, and combinations that have mutually complementary physical properties are used. selected.

If necessary, these thin layer materials may be surface-modified by corona discharge treatment in advance or within the lamination process line.

Coating unit 2゜4.7
As long as the adhesive solution can be applied uniformly by roll coating, kiss coating, gravure coating, etc., the adhesive used may be an acrylic resin-based adhesive that is commonly used in the past.

Vinyl acetate type, ethylene vinyl acetate copolymer type.

Rubber-based materials can be used, but urethane resin-based materials, particularly two-component warm-type materials made of polyol isocyanates such as polyester polyols and polyurethane polyols, are preferred.

As for these adhesive liquids, those with low concentration and low viscosity have a solid content of 1 to 10% by weight, and are about 10 to 80 centimeters in volume, and those with high concentration and high viscosity have a solid content of 15 to 40% by weight, and 90% by weight. It is appropriately selected within a range of about 300 centipoise.

The drying zones 3 and 5.8 may have a heat source such as steam or electric heat to evaporate the solvent of the adhesive, but especially if the in material B is a film with low strength, the drying zone shown in the figure As in zone 8, it is desirable to dry the adhesive solution on the drum transfer surface immediately after application.

Since the method of the present invention has the above-described structure, the second adhesive layer sufficiently wets the surface of the thin layer material and is formed firmly.
A secondary adhesive layer of the same type is formed on the surface of the primary adhesive layer in a sufficiently wet state, so that the adhesive layer between the thin materials exhibits a sufficiently strong adhesive force, and the adhesive layer between the layers in the conventional dry lamination method is The problem of peeling is solved.

Examples Example 1 Using an apparatus as shown in the drawings, a thin layer material A of 15μ
Biaxially oriented nylon film with a thickness of 60 mm as thin layer material B
A μ-thick unstretched polypropylene film was dry-laminated using a urethane resin-based two-component curing adhesive.

The adhesive used had a polyester polyol as its main material, an adduct of hexamethylene diisocyanate and hexanetriol as a curing agent, and the mixing ratio of OH groups to NC○ groups was 1=3, and the solvent was ethyl acetate. The adhesive used in coating units 2 and 7 had a solid content of 7% by weight and a viscosity of 40 centivoise, and the adhesive used in coating unit 4 had a solid content of 30% by weight and a viscosity of 110 centivoise.

The coating unit 2 used a 30μ gravure plate roll, and the coating unit 7 used the same one as a conventional type printing unit for flexographic printing.

The pressure roll 9 was a combination of a metal roll heated to 60°C and a rubber roll, and the cooling roll 10 was a metal roll heated to 18°C.

Laminated product 11 was rolled and left in an atmosphere of 40°C for 5 days, and then the product sample was subjected to a T-shaped peel test to measure the adhesive strength, and it was found to be 500g/15
The nylon film was broken at a width of mm, making measurement impossible.

On the other hand, the peel strength of dry lamination using only coating unit 4 as in the conventional method was 41.
The width was 0(]/15mm.

Example 2 A 60μ thick unstretched polypropylene film was dry laminated in the same manner as in Example 1 onto the aluminum foil surface of a laminate film of a 12μ thick biaxially stretched polyester film and a 9μ thick aluminum foil.

When the same peel test as in Example 1 was conducted, the adhesive strength between the aluminum foil and the polypropylene film was 1250 g /
It was 15mm wide.

In contrast, in the conventional dry lamination method using only the coating unit 4, the width was 650 (1/15 mm).

(1) Effects of the Invention As mentioned above, the present invention not only sufficiently wets the laminated surface with a primary adhesive layer made of a low concentration, low viscosity adhesive solution and increases the bonding area, but also uses a similar high concentration, low viscosity adhesive solution. By forming a secondary adhesive layer with a high viscosity adhesive solution and dry laminating, a laminate with extremely strong interlayer adhesion can be obtained.

[Brief explanation of drawings]

The drawing is a schematic side view of a dry laminating apparatus suitable for carrying out the invention. 1... Thin layer material A 2.4.7... Coating unit 3.5.8...
・Drying unit 6... Thin layer material B9... Pressure roll 10... Cooling roll 11... Laminated product

Claims (1)

[Claims] When laminating and bonding thin layer materials, a low concentration, low viscosity adhesive solution is applied to each laminated surface and dried to form a primary adhesive layer, and then one or both of the primary adhesive layers to be laminated. on the surface of the adhesive solution, which is the same kind and has a high concentration,
A dry lamination method that is characterized by coating and drying a highly viscous adhesive solution to form a secondary adhesive layer, and then laminating and bonding.