JPS5836011B2 - adhesive resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composition of an ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVA) and/or a saponified product of EVA, which has excellent adhesive properties.

More specifically, it relates to a resin composition comprising EVA and/or a saponified product of EVA and a cellulose derivative. The object of the present invention is to obtain a resin composition having excellent melt flowability and moldability, as well as water absorbency and hydrophilicity.

Specifically, the objective is to provide a resin composition useful for extrusion coating resins, film adhesives, lamination adhesives, and the like.

Furthermore, the object is to provide a resin composition that has excellent melt adhesion performance to metals such as iron and aluminum, and materials with smooth surfaces such as polyethylene, polyvinyl chloride, and cellophane, which are conventionally difficult to bond. .

Conventionally, various means have been used to obtain resins or resin compositions having adhesive properties related to EVA.

For example, there is a method of chemically modifying EVA itself.

In this method, EVA is graft-polymerized with α,β-unsaturated carboxylic acid or its anhydride to introduce carboxyl groups to improve adhesion.

However, this method requires a graft polymerization step.

Therefore, when graft polymerization is carried out by solution polymerization, technical operational difficulties such as removal of the solution after completion of polymerization are serious.

On the other hand, there is a method of mixing or kneading EVA and a thermoplastic resin to form a resin composition.

This method is. The equipment is simple and mixing and kneading operations are easier than polymerization operations.

Therefore, attempts have been made to make prototypes of BVA-based resin parabolites with excellent adhesive properties using these methods.

However, one with sufficient adhesive properties has not been obtained.

As a result of research, the present inventor has found that a resin composition with excellent adhesiveness can be obtained by making a homogeneous mixture of EVA and/or its saponified product and a specific cellulose derivative.

The present invention will be described in detail.

EVA and/or its saponified product is mixed and/or kneaded with a cellulose derivative in the presence or absence of an organic peroxide to form a uniform resin composition.

The mixing and kneading method includes EVA and/or
Or, after dissolving the saponified product in a good solvent such as toluene, dichloroethane, n-hexane, etc., and dispersing it in an aqueous cellulose derivative solution, a solvent.

There is a method of removing water to obtain a uniformly mixed resin composition.

Another method is to mix a solution of EVA and/or its saponified product in toluene, dichloroethane, n-hexane, etc. with a solution of a cellulose derivative in methyl alcohol, acetone, methyl acetate, etc., and remove the solvent.

A cellulose derivative soluble in an aromatic solvent can be obtained by simultaneously dissolving and mixing EVA and/or its saponified product and the cellulose derivative in an aromatic solvent.

Furthermore, as another method, EVA and/or its saponified product and a cellulose derivative are kneaded in the presence or absence of an organic peroxide using a kneading device such as a roll or a kneader.

It is desirable that the cellulose derivative be dissolved in water, methanol, acetone, methyl acetate, etc., and added to the resin wound around a roll.

When carried out in a heated state in a method using a solvent, EVA
It becomes easy to obtain a resin composition in which the cellulose derivative and the cellulose derivative are uniformly mixed.

Further, it is preferable to use an apparatus having a forced stirring mechanism.

In the case of a method of kneading using a kneading device such as a roll or a kneader, the kneading temperature is higher than the melting point of BVA and lower than 1 degree of decomposition.

When cellulose is used as a solution in a solvent such as water, methanol, acetone, or methyl acetate, it is preferable to keep the temperature relatively high in order to prevent the crosstalk temperature from dropping rapidly.

Specifically, a temperature of 120°C or higher is sufficient.

Further, the time for kneading may be selected so as to provide a uniformly mixed resin composition.

but. When the cellulose derivative is used in solution, it is preferable to mix the mixture for a longer period of time since this involves removal of the solvent.

When EVA and/or its saponified product and cellulose derivative are kneaded in the presence of peroxide.

It is preferred that kneading be carried out for a sufficient period of time until substantially no peroxide remains.

Specifically, 5 minutes or more is suitable.

The EVA used in the present invention has an ethylene content of 80 to 98 moles, regardless of whether it is produced by a high-pressure polymerization method under 1000 to 3000 atmospheres or a solution or emulsion polymerization method under 100 to 400 atmospheres. % range, the effects of the present invention can be fully exhibited.

In addition, the melt index is 0.1 to 500.9/10
yniyr is preferred.

In addition, as the EVA saponification product, the above-mentioned EVA is
Preferably, it is saponified to 100%.

The saponification reaction may be carried out according to a known saponification method using an acid or an alkali as a catalyst.

As a cellulose derivative, 1 selected from the formula [wherein R is hydrogen, methyl group, hydroxyprol group, hydroxypropyl group, +CH2-CH-]
It has a repeating unit of [indicating more than one type of substituent], and one or more types are used.

Examples of cellulose derivatives include hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, acetylcellulose, cellulose acetate phthalate, and carboxymethylcellulose.

The effect of the present invention can be achieved when the amount of the cellulose derivative is in the range of 1 to 50 parts by weight based on 100 parts by weight of EVA and/or its saponified product; if it is more or less than that, the adhesive strength will be insufficient, and .

When the amount exceeds 50 parts by weight, transparency also decreases.

In the production of a resin composition of EVA and/or its saponified product and a cellulose derivative, an organic peroxide is added as necessary, and the amount thereof is appropriately selected within the range of 1 part by weight or less.

Examples of organic peroxides include diacyl peroxides such as benzoyl peroxide, peroxy esters such as t-butylperoxypivalate and t-bunalbaroxydio**toate, and dialkyl peroxides such as dicumyl peroxide.

Examples include hydroperoxides such as t-butyl hydroperoxide.

The fat composition of the present invention has excellent adhesive properties and has physical properties and properties that can be used in extrusion coating resins, film adhesives, lamination adhesives, and the like.

Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

Examples 1 to 4, Comparative Example 1 The following formulation was kneaded using a 3-inch roll.

EVA 40g (vinyl acetate content 20% by weight, melt index 20g/ion side) 2% cellulose derivative aqueous solution 100g benzoyl peroxide 1% acetone solution 4g After melting EVA, the cellulose derivative was added.

After further adding benzoyl peroxide, 150
The mixture was kneaded at ℃ for 10 minutes.

This composition was made into a 100μ film, sandwiched between two aluminum plates, heated at 150°C, Lookν'crkD
The T-peel strength was measured by thermocompression bonding under the following conditions.

The results are shown in Table 1. It can be seen from Table 1 that the resin composition made of EVA and a cellulose derivative has excellent adhesive properties.

Examples 5 to 12, Comparative Example 2 The following formulation was kneaded in the same manner as in Examples 1 to 4.

EVA saponification product 40g (vinyl acetate content 28% by weight, MI 189/10ynin EVA saponification product 80%) Cellulose derivative 2% solution IoOg benzoyl peroxide 1% acetone solution 4g Among cellulose derivatives, only cellulose acetate phthalate is in acetone solution The other cellulose derivatives were added as an aqueous solution.

The results of A-Mk13T peel strength are shown in Table 2.

Claims (1)

[Scope of Claims] 1(A) 100 parts by weight of an ethylene-vinyl acetate copolymer and/or saponified product thereof having an ethylene content of 80 to 98 mol%, -CI-12COOM (where M is 1 to 50 parts by weight of one or more types of cellulose derivatives having a repeating unit of [representing one or more substituents selected from hydrogen or alkali metals] and (C) 0 to 1 part of an organic peroxide; An adhesive resin composition consisting of. 2 The cellulose derivative is hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose,
The resin composition according to claim 1, which is selected from cellulose acetate, cellulose acetate phthalate, and carboxymethyl cellulose. 3 The organic peroxide is dialkyl peroxide, diacyl peroxide, and peroxy ester. The resin composition according to claim 1 or 2, which is selected from hydroperoxides.