JPS5967048A - Laminate - 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 relates to a laminate, and more specifically to polyester wood JI!
The present invention relates to a laminate in which a layer and a base material layer such as metal are laminated with an adhesive composition layer interposed therebetween.

Polyester resin has gas barrier properties and oil resistance.

Although it has excellent properties such as strength, it has high moisture permeability (and is expensive, so it cannot be used as a single material for food packaging films, containers, fuel tanks, etc.). In order to improve this drawback, it has been proposed to laminate polyester resin with metal, resin other than polyester resin, etc.

However, since polyester resin has very low adhesion to metals, special surface treatments or primer coating are usually performed. However, even with surface treatment, the adhesion strength is not sufficient, and the use of primers not only poses problems such as deterioration of the working environment and pollution caused by evaporation of the solvent, but also the need to maintain a good coated surface. The disadvantage is that adjustment is difficult. For this reason, it has been proposed to use a hot melt type resin, but this resin does not have sufficient adhesive strength, and adding a tackifying resin with a low softening point reduces heat resistance, and the essential adhesive strength is not strong enough. The current situation is that it is not improving. In order to solve this problem of 1inA, a method has been proposed in which the polyester resin and the metal are laminated by interposing two adhesive resins each having adhesive properties. A method has also been proposed in which a resin mixture obtained by modifying with an unsaturated carboxylic acid or its anhydride is interposed and laminated. However, the former method, which uses two types of adhesive resins individually, has poor workability, and the latter method has the disadvantage of having to modify each of the two resins in the production of the modified product, and is limited to ethylene resins. It is something that

This study solved these shortcomings and maintained a wide range of properties such as gas barrier properties, moisture impermeability, machinability, @proofing properties, and printability, as well as excellent adhesive strength and a single contact 7&J composition layer. The object of the present invention is to provide a laminate that can be used in a wide range of combinations with various base materials.

That is, the present invention uses an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 70% by weight and 50 to 999% by weight.
This is a laminate in which a polyester resin layer and a base material layer are laminated via an adhesive composition layer consisting of 50 to 0.11% by weight of a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof.

In the present invention, the adhesive composition interposed as an adhesive layer between the polyester resin layer and the base layer contains 50 to 99.9% by weight of the ethylene-vinyl acetate copolymer and 50 to 1 mm% of the modified polyolefin resin, as described above. This is a blended composition.

The ethylene-vinyl acetate copolymer used has a vinyl acetate content of 10 to 70% by weight, preferably 12 to 50% by weight, and is appropriately selected in consideration of the type and use of the material to be treated. In addition, this copolymer has a tart index (MI) of 0.1 to 300 g/10 min, preferably 0.5 g/10 min.
~10 (1710 minutes) is used. If the vinyl acetate content is less than 10% by weight, sufficient adhesive strength will not be obtained. If it exceeds 70% by weight, the melting point will be low and the elasticity of the adhesive base material will be low. This is not preferable because the adhesive layer has a low strength and tensile strength, and the strength of the adhesive layer at the operating temperature is insufficient.

Next, as the modified polyolefin resin, a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof or a mixture of a Seikan 4 main polyolefin resin and an unmodified polyolefin resin is used. The polyolefin resin to be modified is preferably a polypropylene-based resin such as a propylene homopolymer or a block or random copolymer of fluoropylene and another copolymer component such as ethylene. That is, in the present invention, ethylene-
A major feature is that it is more preferable to blend a modified polypropylene resin than to use a modified crystalline ethylene monomer, which is a polymer more similar to vinyl acetate copolymer.

Here, the unsaturated carboxylic acid is acrylic acid.

Methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, sorbin.

These include mesacone, angelic acid, etc. Soil, and its derivatives include their acid anhydrides and esters.

There are amides, imides, metal salts, etc., such as maleic anhydride, itaconic anhydride, and citraconic anhydride.

Methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, maleic acid monoethyl ester, acrylic acid monoamide, maleic acid monoamide, maleimide, N-butylmaleimide, sodium acrylate, sodium methacrylate, etc. Among these, acid anhydrides such as maleic anhydride, esters such as methyl acrylate, and amides such as ethyl acrylate are particularly preferred.

The method for modifying the polyolefin resin with these unsaturated carboxylic acids or derivatives thereof is not particularly limited, and various known methods can be used.

For example, a polyolefin resin and maleic anhydride can be modified by cooling and heating a radical initiator in the presence or absence of a solvent. During the reaction, other vinyl monomers such as styrene or rubbers such as liquid rubber and thermoplastic rubber may also be present.

The content of unsaturated carboxylic acid or its derivative in the modified polyolefin resin thus obtained is usually 0.00
01-15%, preferably 0.005-10%,
More preferably, it is in the range of 0.05 to 5 M%.

Here, the combination of the ethylene-vinyl acetate copolymer and the modified polyolefin UjJ resin in the adhesive composition or 7
The weight ratio is 5 to 97%, and the modified polyolefin resin is 50%
~0. ln1M%, preferably 40 to 1% by weight, more preferably 25 to 3% by weight. If the blending ratio of both is outside this range, the composition will have poor adhesive properties, which is not preferable.

As the components of the adhesive composition layer in the present invention, the above two components are basically sufficient, but other thermoplastic resins, thermoplastic rubbers, Furthermore, tackifiers such as rosin resins and polyterpene resins, waxes, and the like can be added.

Also, various fillers and antioxidants as necessary.

An ultraviolet absorber, an antistatic agent, a dispersant, etc. may also be added.

The laminate of the present invention is formed by laminating a polynister resin layer and a base material layer via the above-mentioned adhesive composition.

Here, polyester resins include polyethylene terephthalate, polybutylene terephthalate, etc.
Particularly preferred is polybutylene terephthalate. Polyester resin is treated with corona discharge to achieve a wettability index of 40 on the adhesive surface.
~50 dYn/m is used. The wettability index of the adhesive surface is 40 dyn/. If it is less than 111, the adhesive strength with the adhesive composition layer will not be sufficient, which is not preferable.

Next, the base material, which is one of the components constituting the laminate of the present invention, includes metals such as iron, stainless steel, aluminum, copper, and plated steel sheets, polyolefins such as polyethylene and polypropylene, polystyrene, ABS resin, and AS. Resins, polyamide resins such as 6-nylon and 6,6-nylon, and resins such as saponified 5-ethylene-vinyl acetate copolymers are used.

As a method for obtaining the laminate of the present invention, any known method may be employed. For example, a method of sandwiching an adhesive composition between a base material and a polyester resin and compressing it, a method of laminating a polyester resin and an adhesive composition in advance and then press-bonding it to the base material, a method of coextrusion (inside die lamination, outside die lamination) Any method such as a molding method can be applied. Even if 74 laminates are manufactured using either method, the laminate can be manufactured with almost no influence υ due to the type of laminate.

In addition, the carcass according to (a) of the present invention is formed by laminating a polyester resin layer and a base material layer with an adhesive composition layer interposed therebetween.
Furthermore, a multilayer laminate may be formed by laminating a polyester resin layer or the like on the outside of the base material layer via an adhesive composition layer.

According to the present invention, the properties of the polyester resin and the base material, namely gas barrier properties, light printability, printability, and rigidity.

It is possible to obtain a laminate that maintains a wide range of properties such as heat resistance and has excellent adhesive strength. ,Also.

Since the polyester resin and the base material can be bonded with a single adhesive composition, the bonding process can be carried out simply and in a short time, and high-speed molding is possible. Moreover, it is safe because no solvents or the like are used for bonding.

Therefore, the product of the present invention is juice bag.

It can be suitably used for food packaging films such as Lutopak, lightweight containers, and the like.

Next, the present invention will be explained by examples.

Examples 1 to 10 Ethylene-vinyl acetate copolymer (vinyl acetate content ia: 3
2: mm%, hI = 309/10 min) and maleic anhydride-modified polypropylene (maleic anhydride content 40
A laminate was obtained by pressing a mixed adhesive composition containing 1% (RffI=+300/10 minutes) between corona discharge treated polyethylene terephthalate and a substrate with an extrusion roll.

The lamination conditions were a resin temperature of 200'C.

The cooling roll temperature was 16°C, the recording pressure was 7kg/c, n, and the take-up speed was 50m7g, and the thickness of each layer of the obtained laminate was 25μ for the polyethylene terephthalate layer, 20μ for the adhesive composition layer, and 40μ for the base material layer. . Table 1 shows the T peel strength of the obtained laminate.

Example 11 Vinyl acetate content 1 as ethylene-vinyl acetate copolymer
The same operation as in Example 2 was carried out except that 5% by weight and λfI=14/710 minutes were used. The results are shown in Table 1.

Comparative Example 1 The same operation as in Example 2 was performed except that an ethylene-vinyl acetate copolymer having a vinyl acetate content of 6% was used. The results are shown in Figure 1.

Comparative Example 2 The same operation as in Example 2 was performed except that modified polypropylene was not used. The results are shown in Figure 1.

Comparative Example 3.4 The same operation as in Example 2 was carried out except that a polyethylene terrestrial crate not subjected to corona discharge treatment was used. The results are shown in Table 1.

*IEVA: Ethylene-vinyl acetate copolymer *2 Modified P
P: Modified polypropylene + 3 PET: Polyethylene terephthalate + 4 LDP
E: Low density polyethylene (density 0.924 MI=
0.3'7/10 min) *5 In) PE: High density polyethylene (density 0.954 MI=0.l/10 min)
Ne6 PP: Polypropylene

Claims (1)

Scope of Claims (11) A polyolefin resin modified with an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 70% by weight and 50 to 99.9% by weight and an unsaturated carboxylic acid or a derivative thereof. A laminate formed by laminating a polyester resin layer and a base material layer via an adhesive composition layer consisting of .1% overlay.(2) Claims in which the polyester resin is polyethylene terephthalate subjected to corona exposure treatment. The laminate according to claim 1, wherein the modified polyolefin resin is a modified polypropylene resin. (4) The laminate according to claim 1, wherein the base material is a metal or resin. 184. The laminate described in 184.