JP2000129231A - Heat resistant adhesive resin composition and laminate thereof - Google Patents

Abstract

(57) [Problem] To provide an adhesive resin composition excellent in high-temperature processability and heat resistance and exhibiting good adhesiveness even to a resin having no polar group such as polystyrene, and a laminate thereof. . The resin composition comprises 50 to 99% by weight of an ethylene-α-olefin copolymer, 1 to 50% by weight of a hydrogenated petroleum resin, 5 to 99% by weight, and 1 to 95% by weight of a high-density polyethylene. A heat-resistant adhesive resin composition is obtained, and the heat-resistant adhesive resin composition is formed into a laminate 1 by extruding an adhesive resin layer 20 serving as a sealant layer on a substrate 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive resin composition and a laminate obtained by laminating the adhesive resin composition, and more particularly to a heat-resistant adhesive resin composition comprising a sealant layer. As a heat-sealable laminate.

[0002]

2. Description of the Related Art Adhesive resins include a wide variety of natural polymers, thermosetting polymers, thermoplastic polymers, rubber polymers, hot melts, instant adhesives and the like. The adhesive resin to be selected differs depending on the performance and the intended use. As an intended use of such an adhesive resin, for example, there is a case where a higher function is achieved by bonding different materials.

For example, in the field of food packaging, such adhesive resins are used as sealants for lids of cups or tray containers. Examples of the material of these containers include expanded polystyrene represented by a cup ramen container, polystyrene represented by a container such as jelly, and yogurt, and polypropylene.

In these materials, when a material having no polar group such as polystyrene and a material having no polar group such as polyethylene are heat-sealed,
Adhesion has not been obtained, and a system using a tackifier as a material having good adhesion has been studied.

For example, a method using a composition of an ethylene-vinyl acetate copolymer and a tackifier, and a polyolefin composition obtained by blending an ethylene-vinyl acetate copolymer and an aliphatic petroleum resin with a modified polyolefin have been proposed. However, in practice, these adhesive resin compositions have a disadvantage that they are inferior in hue, weather resistance and adhesiveness.

An adhesive resin composition comprising an ethylene-α, β-unsaturated carboxylic acid copolymer and a tackifier such as an ethylene-vinyl acetate copolymer and an alicyclic hydrocarbon resin is also known. Although proposed, good adhesion to polystyrene has not been obtained.

Further, a method has been proposed in which a polar group is introduced into a polyolefin-based resin to impart an adhesive function. In this method, a monomer having a functional group such as an acrylic acid group, a methacrylic acid group, an acrylate group, a methyl methacrylate group, or a maleic anhydride group is copolymerized with an α-olefin such as ethylene and propylene under high pressure. A resin has been proposed which is made into a random copolymer or a monomer obtained by grafting a monomer having the above functional group to ethylene, propylene or two or more α-olefin copolymers as a graft copolymer by a catalytic polymerization method or the like.

However, a laminating method by a T-die method is generally used as a processing method for forming a laminate.
It is desirable to be able to extrude at a high temperature in order to obtain good adhesion to the substrate, but the adhesive resin composition proposed above is difficult to extrude at a high temperature due to poor heat resistance, and has good adhesion with polystyrene. Is not obtained.

In recent years, there has been an increasing demand for heating the entire packaging container in a microwave oven. However, heat is applied too much during the microwave oven and the container is peeled off. At present, no sealant has been obtained.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has as its object to be excellent in high-temperature workability and heat resistance and to have a polar group such as polystyrene. An object of the present invention is to provide an adhesive resin composition exhibiting good adhesiveness to a resin not to be used and a laminate thereof.

[0011]

In order to achieve the above object, the present invention relates to a petroleum resin hydrogenated from 50 to 99% by weight of an ethylene-α-olefin copolymer. From 50 to 99% by weight and a high-density polyethylene from 1 to 95% by weight.

In the invention of claim 2, the ethylene-α-olefin copolymer is synthesized by using a single-site catalyst, and comprises butene-1, hexene-1, octene-1, and 4-methyl-pentene-1. The heat-resistant adhesive resin composition according to claim 1, comprising a copolymer of ethylene and a comonomer selected from the group consisting of:

Further, in the invention according to claim 3, the ethylene-α-olefin copolymer has a density of 0.860 or more.
The heat-resistant adhesive resin composition according to claim 1 or 2, wherein the composition is not more than 925.

Further, in the invention of claim 4, the petroleum resin is an alicyclic petroleum resin.
4. The heat-resistant adhesive resin composition according to any one of Items 1 to 3.

According to a fifth aspect of the present invention, the hydrogenated petroleum resin has a hydrogenation ratio of 10 to 100%. The adhesive resin composition was used.

The heat-resistant adhesive resin according to any one of claims 1 to 5, wherein the petroleum resin has a softening point of 70 ° C to 150 ° C. It was a composition.

[0017] In the invention of claim 7, according to claim 1,
The heat-resistant adhesive resin composition according to any one of to 6,
A laminated body characterized in that an adhesive resin layer serving as a sealant layer is formed by being laminated on a base material.

Further, in the invention according to claim 8, the adhesive resin layer serving as the sealant layer is formed by extruding a heat-resistant adhesive resin composition. It is a body.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail. The high-density polyethylene used in the heat-resistant adhesive resin composition of the present invention is a polyethylene produced by a medium-pressure method or a low-pressure method, and preferably has a density of 0.930 g / cm ³ to 0.970 g / cm ³ . Also, at 190 ° C, 2
Melt flow rate at 160 g load is 0.1 g
/ Min or more and 30 g / min or less, more preferably 2.0 or more and 30 g / min or less.

The ethylene-α-olefin copolymer used in the heat-resistant adhesive resin composition of the present invention is synthesized from a Ziegler catalyst or a single-site catalyst, preferably synthesized from a single-site catalyst. Is what is done.

The single-site catalyst is not particularly limited, but is exemplified by a cyclopentadienyl zirconocene derivative and a transition metal such as Zr, Ti, Hf and the like, such as a cyclopentadienyl ring and an indenyl ring. A so-called metallocene catalyst comprising a saturated ring is exemplified.

As another example of the single-site catalyst, a conventional Ziegler-Natta catalyst is modified to be a single-site catalyst, and the ratio Mw between the weight average molecular weight and the number average molecular weight of the polymer is Mw. / Mn of 2.5 or less, preferably 2.0 or less can be used.

The conomers of the ethylene-α-olefin copolymer in the heat-resistant adhesive resin composition of the present invention include:
Any one selected from butene-1, hexene-1, octene-1, 4-methyl-pentene-1 and the like may be used, and ethylene-α-olefin copolymer containing butene-1, hexene-1, and octene-1 as comonomers may be used. Since it is inexpensive to combine, it can be suitably used.

The density of the ethylene-α-olefin copolymer in the heat-resistant adhesive resin composition of the present invention is 0.8
It is preferably 60 or more and 0.925 or less, and if it is less than 0.860, heat resistance is impaired, and processability is further deteriorated. On the other hand, if it is larger than 0.925, the adhesiveness becomes poor. Therefore, the density of the ethylene-α-olefin copolymer is preferably 0.880 or more and 0.920 or less, and more preferably 0.890 or more and 0.910 or less. The melt flow rate at 190 ° C. and a load of 2160 g is selected from those having a melt flow rate in the range of 0.1 to 30 g / 10 min.

The petroleum resin in the heat-resistant adhesive resin composition of the present invention may be any one selected from aliphatic petroleum resins, aromatic petroleum resins, copolymer petroleum resins, and alicyclic petroleum resins. Of these, alicyclic petroleum resins are particularly preferred. Further, these petroleum resins may be blended and used. In addition, rosin, polymerized rosin, hydrogenated rosin, rosin glycerin ester and its hydrogenated product or polymer, rosin such as rosin pentaerythritol and its hydrogenated product or polymer can be added within a range that does not impair the purpose, About 0.1 to 10% by weight of the petroleum resin is desirable.

The hydrogenation ratio of the above petroleum resin is preferably from 10 to 100%, more preferably from 30 to 100%. Hydrogen addition ratio is 1
If it is less than 0%, it is not preferable because it is easily decomposed and easily yellowed.

The method of kneading the ethylene-α-olefin copolymer, petroleum resin, and high-density polyethylene is not particularly limited, but dry blending is simple. But,
In consideration of the stability of physical properties, it is more desirable to perform melt mixing using a single-screw extruder, a twin-screw extruder, a kneader, a hot roll, or the like.

The above blend may be prepared by melt-mixing an ethylene-α-olefin copolymer and a petroleum resin into pellets and then dry-blended with high-density polyethylene.

The heat-resistant adhesive resin composition of the present invention may further contain, if necessary, an antioxidant, a stabilizer, a lubricant, an antiblocking agent, an antistatic agent, an antifogging agent, a tackifier, a filler, a coloring agent. Additives such as agents can be added.

Further, in the present invention, as shown in FIG. 1, the heat-resistant adhesive resin composition as described above is laminated on a substrate (10) to form an adhesive resin layer (20) serving as a sealant layer. The adhesive resin layer (20) serving as a sealant layer is formed by extrusion of a heat-resistant adhesive resin composition. is there.

As described above, the extrusion molding method includes an extrusion lamination method using a T-die. In particular, a substrate (10) made of aluminum foil, paper, or the like is formed at 300 ° C. by a T-die method.
Extrusion lamination as described above has the effect of eliminating the need to use an adhesive or the like, and is a preferred molding method.

The substrate (10) is not particularly limited, but is generally a stretched polyester film, a stretched polypropylene film, a stretched nylon film, an aluminum foil, paper, or the like. What laminated | stacked films may be used.

The material to be bonded to the heat-resistant adhesive resin composition of the present invention includes polystyrene, polyester, polypropylene, polyethylene, polycarbonate and the like. These materials may be foams. Good adhesiveness can be obtained with any of the materials.

In general, the pressure-sensitive adhesive is mainly composed of a tackifier and an elastomer, and has properties in which tackiness, holding power, and tack are indispensable. The elastomer is easy to flow by being compatible with the tackifier, and is adhered to the surface of the adherend with wettability and affinity.The adhesive behavior of the heat-resistant adhesive resin composition of the present invention is By applying, the ethylene-α olefin copolymer is likely to flow, and it is considered that adhesion with the adherend surface is performed,
It is considered that the heat-sensitive adhesive and its mechanism are similar. However, in the pressure-sensitive adhesive, for example, those having a structure similar to ethylene-α-olefin, those having an acrylic polymer and a tackifier as main components are typical, but the pressure-sensitive adhesive with the adherend has a functional group. Existence is essential.

Although the details of the adhesive behavior in the case of having no functional group such as ethylene-α-olefin constituting the heat-resistant adhesive resin composition of the present invention are unknown, the resin is oxidized by heat during processing. It is presumed that a functional group is formed and adheres.

[0036]

Next, the present invention will be described in detail with reference to examples. <Example 1> Polyethylene terephthalate film having a thickness of 20 µm, which is a biaxially stretched film; Espet E51
A base material (10) was obtained by laminating a high-density polyethylene (HDPE) having a density of 0.941 g / cm ³ and Novatec HD (manufactured by Nippon Polychem Co., Ltd.) with a thickness of 20 μm on 00 (manufactured by Toyobo Co., Ltd.). On the high-density polyethylene side of the substrate (10), an ethylene-α-olefin copolymer (density 0.9
05g / cm ³ ); 10% by weight of kernel 57L (manufactured by Nippon Polychem) and alicyclic petroleum resin; Alcon P-11
5 (manufactured by Arakawa Chemical Industries) 10% by weight and density 0.941g
/ Cm ³ high-density polyethylene (HDPE); 80% by weight of Novatec HD (manufactured by Nippon Polychem Co., Ltd.) is extruded at 320 ° C. with a thickness of 25 μm at a temperature of 320 ° C. using a twin-screw extruder. (20) was formed to obtain a laminate (1). At that time, the extruded molten film was excellently rolled off from the cooling roll without foaming, surging and draw resonance, and was well laminated on the substrate (10).

The above-prepared laminate (1) was prepared with a width of 15 m.
m, and cut into a polystyrene paper (PSP) with an expansion ratio of 12 times and a polystyrene sheet (P
S), heat-sealed at 130 ° C. to 160 ° C. with an injection-molded polyester (polyethylene phthalate; PET) plate, and measured the heat seal strength.
Was obtained.

[0038]

[Table 1]

From these results, it was found that the heat-resistant adhesive resin composition of the present invention had excellent heat sealing strength, and the strength increased as the heat sealing temperature was increased.

Further, after a mixture of water and vegetable oil is filled in a tray on which paper and polyester are laminated, the laminate (1) film prepared above is heat-sealed, air holes are formed, and a 500 W household It was placed in a microwave oven for 6 minutes. As a result, a favorable sealing state was maintained without peeling of the film.

[0041]

According to the present invention having the above configuration, the following effects can be obtained. That is, heat resistance consisting of a resin composition 5 to 99% by weight of 50 to 99% by weight of an ethylene-α-olefin copolymer, 1 to 50% of hydrogenated petroleum resin, and 1 to 95% by weight of a high-density polyethylene. Since the adhesive resin composition was used, a laminate using the same is excellent in high-temperature workability and heat resistance, and has extremely good adhesion with a polystyrene sheet or polyethylene terephthalate.
This has the effect of having good adhesiveness to a resin having no polar group or reactive functional group.

Accordingly, the present invention exerts an excellent practical effect as a packaging material for foods and the like that require heat resistance.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a laminate using a heat-resistant adhesive resin composition of the present invention in a side cross section.

[Explanation of symbols]

 1 laminated body 10 base material 20 adhesive resin layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F100 AK02A AK02H AK05A AK12B AK42B AK63A AK63K AK80A AK80H AK80K AL05A AT00B BA02 CA16A EH17A GB16 GB23 JA04A JA04H JA13A JJ03 JK02 JL01 JL02 Y02 DA03 MA02 MA10 MA11 NA06 PA30 QA08

Claims (8)

[Claims] 1. A resin composition comprising from 50 to 99% by weight of an ethylene-α-olefin copolymer, from 1 to 50% by weight of a hydrogenated petroleum resin, from 5 to 99% by weight, and from 1 to 95% by weight of a high-density polyethylene. A heat-resistant adhesive resin composition comprising: 2. The ethylene-α-olefin copolymer according to claim 1,
Butene-synthesized with a single-site catalyst
The heat-resistant adhesive resin composition according to claim 1, comprising a copolymer of ethylene and a comonomer selected from 1, hexene-1, octene-1, and 4-methyl-pentene-1. 3. The heat-resistant adhesive resin composition according to claim 1, wherein the density of the ethylene-α-olefin copolymer is 0.860 or more and 0.925 or less. 4. The heat-resistant adhesive resin composition according to claim 1, wherein the petroleum resin is an alicyclic petroleum resin. 5. The heat-resistant adhesive resin composition according to claim 1, wherein the hydrogenated petroleum resin has a hydrogenation ratio of 10 to 100%. 6. A petroleum resin having a softening point of 70 ° C. or higher and 15
The heat-resistant adhesive resin composition according to any one of claims 1 to 5, wherein the temperature is 0 ° C or lower. 7. A heat-resistant adhesive resin composition according to any one of claims 1 to 6, wherein the heat-resistant adhesive resin composition is laminated on a base material to form an adhesive resin layer serving as a sealant layer. Laminate. 8. The laminate according to claim 7, wherein the adhesive resin layer serving as the sealant layer is formed by extruding a heat-resistant adhesive resin composition.