Polar group-containing olefin copolymer, multinary polar olefin copolymer, olefin resin composition, and adhesive material, laminate, and other application products using same

Abstract

The present invention relates to a polar group-containing olefin copolymer (A′) which is produced through polymerization using a transition metal catalyst, which has a weight-average molecular weight falling within a specific range and which contains a polar group-containing monomer within a specific range; a multinary polar olefin copolymer (A″) indispensably containing a polar monomer component that has a norbornene skeleton and a carboxyl group or an acid anhydride group and having three or more types of monomer units; and a resin composition (C) containing a specific amount of a polar group-containing olefin copolymer (A) and a specific amount of an olefin resin (B).

Description

TECHNICAL FIELD[0001]The present invention relates to a polar group-containing olefin copolymer, a multinary polar olefin copolymer and an olefin resin composition, and to an adhesive material, a laminate and other application products using the same, and more precisely, relates to a polar group-containing olefin copolymer, a multinary polar olefin copolymer and an olefin resin composition having a specific polar group and having excellent adhesiveness to various substrate materials, and to an adhesive material, a laminate and other application products using the performance thereof.BACKGROUND ART[0002]In general, olefin polymers such as polyethylene and polypropylene have high mechanical strength, are excellent in chemical resistance and corrosion resistance, inexpensive and excellent in moldability, and have environmental suitability, and are therefore valued as industrial materials, and for example, through injection molding, extrusion molding, blow molding or the like, such poly...

AI Technical Summary

Benefits of technology

The present invention relates to a polar group-containing olefin copolymer (A′) and a multinary polar olefin copolymer (A″) that have specific molecular structures and resin properties. These copolymers are useful in producing laminates that exhibit high adhesiveness to substrates such as EVOH resin or amide resin, and excellent mechanical and thermal properties. The resulting laminates can be used in a wide range of applications. The invention also involves an olefin resin composition containing the polar group-containing olefin copolymer (A) and another olefin resin (B) in a specific amount. This composition has excellent adhesiveness and can be molded into various molded articles such as films, blow-molded bottles, and others.

Problems solved by technology

However, olefin polymers are generally nonpolar, and therefore in using them for laminate materials, they have some drawbacks in that their adhesive strength to different types of materials having high polarity such as other synthetic resins metals, wood and the like is extremely low or the polymers could not adhere to those materials.

However, according to the method, there may occur intermolecular crosslinking of the olefin polymer molecules and molecular chain cutting of the olefin polymers along with the grafting reaction thereof, and therefore the method is problematic in that the graft-modified derivatives could not maintain the excellent physical properties of polyolefins.

For example, introduction of any unnecessary long-chain branches through intermolecular crosslinking may increase the melt viscosity and broaden the molecular weight distribution, therefore having some negative influences on the adhesiveness and the moldability of the polymers.

In addition, molecular chain break may increase low-molecular-weight fragments of polyolefin, therefore bringing about some problems of burr formation and fuming during molding.

The adhesiveness to other high-polar materials may be increased by increasing the polar group content during olefin copolymerization; however, it is not easy to graft a polyolefin with a large amount of a polar group-containing monomer through graft modification.

The method, when employed, would bring about further intermolecular crosslinking and molecular chain break of olefin polymers, therefore detracting from the physical properties of polyolefins.

In addition, the amount of the unreacted polar group-containing monomer and the amount of the decomposed product of the organic peroxide that may remain in the resin would increase, therefore bringing about other troubles that the resin degradation would be promoted and some offensive odor may come into existence.

Consequently, the attempt to increase the content of the polar group-containing monomer in the resin is naturally limited.

However, the effect of preventing intermolecular crosslinking and improving the graft efficiency is limitative, and in addition, it is impossible to prevent the formation of residues of the unreacted polar group-containing monomer and the decomposed product of organic peroxide that are fundamental harmful results in graft modification, or that is, the method could not as yet be a sufficient improved method.

Consequently, as compared with olefin copolymers to be produced through polymerization with a metal catalyst, only a polar group-containing olefin copolymer having a low elastic modulus and low mechanical properties can be obtained, and the range of application to the use that requires high strength is limitative.

However, the keynote of the methods described in these references essentially resides in copolymers of an acrylate group-containing monomer such as methyl acrylate or ethyl acrylate or a specific polar group-containing monomer such as vinyl acetate with ethylene or an α-olefin; and the adhesiveness of those polar group-containing polyolefins having such a functional group to other high-polar materials is not sufficient.

However, as a result of evaluations made by the present inventors, their performance is insufficient (in particular, for adhesiveness, see Examples of the present application shown hereinunder).

In addition, there has also been reported a production method for a multinary copolymer using a norbornene polar comonomer (PTL 19); however, the method is limited to production of an acrylate copolymer having a low olefin content by the use of a radical polymerization catalyst.

However, according to that invention, the polar group-containing olefin copolymerization requires a large amount of organic aluminum, and therefore the product cost is inevitably high.

In addition, such a large amount of an organic aluminum exists in the copolymer as an impurity therein, and removing it results in further cost increases.

However, the production method for the polar group-containing olefin copolymer proposed by that patent reference requires previous masking of the polar group through reaction the polar group-containing cyclic olefin to be used for polymerization with an organic metal compound, and further requires demasking treatment after the copolymerization step, and therefore, the constitutive steps of the production method are complicated and the production cost thereof is therefore inevitably high.

Further, the organic metal compound used for the masking may remain in the copolymer, therefore having some negative influence on various resin properties, and removing the residue would result in further increase in the production cost.

In case where a polar group-containing olefin copolymer is produced according to these methods, it is necessary to take a step of previously preparing an olefin polymer having a double bond in the molecular chain through polymerization followed by reacting the double bond part in the olefin copolymer with a polar group-containing compound; and as compared with the case of obtaining a polar group-containing olefin copolymer through direct copolymerization of a polar group-containing vinyl monomer and ethylene or an α-olefin, the production process is complicated and the product cost therefore increases.

Further, in the case of obtaining the polar group-containing olefin copolymer through modification of an olefin copolymer having a double bond at one end or at both ends, it is impossible to separately control the molecular weight of the polymer chain and the polar group content, from the principle of the method, and as a result, the use of the obtained polar group-containing olefin copolymer is to be limitative.

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