JP2002187914A - Method for producing modified ethylene polymer - Google Patents

Abstract

(57) [Abstract] [Object] To provide a method for producing an unsaturated carboxylic acid or an anhydride-modified ethylene polymer thereof, which is capable of obtaining a laminate having excellent adhesion to an adherend and excellent surface appearance. provide. [Constitution] In producing a modified ethylene polymer by subjecting an ethylene polymer and an unsaturated carboxylic acid or an anhydride thereof to a graft reaction condition in the presence of a radical generator, two or more raw material supply ports and 1 Using a twin-screw extruder having at least one vent port, an unsaturated carboxylic acid or an anhydride thereof is injected in a fluid state into an ethylene-based polymer at a temperature of 100 to 250 ° C, and the polymer temperature in the kneading unit is adjusted to 2
After the unsaturated carboxylic acid or its anhydride is added to the ethylene polymer by melt-kneading at 00 to 270 ° C., and then subjected to devolatilization treatment from the vent port, the residence time of the ethylene polymer in the extruder is reduced. A method for producing a modified ethylene polymer, which is melt-extruded at least three times the 99.9% decomposition time of the radical generator at the polymer temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an unsaturated carboxylic acid or an anhydride-modified ethylene polymer thereof, and more particularly, to a laminate having excellent adhesion to an adherend and excellent surface appearance. Can get the body,
The present invention relates to a method for producing an unsaturated carboxylic acid or an anhydride-modified ethylene polymer thereof.

[0002]

2. Description of the Related Art Conventionally, olefin polymers such as ethylene polymers and propylene polymers have excellent moldability, mechanical properties, water vapor barrier properties, chemical resistance, heat sealing properties and the like. It is widely used as a material for various packaging and containers, but it is inferior in gas barrier properties such as oxygen gas and carbon dioxide gas, and in content protection such as flavor and fragrance retention.
In addition, there is a drawback that the printability and the paintability are poor.

[0003] As a method of improving these drawbacks in olefin polymers, polyester resins,
A saponified ethylene-vinyl acetate copolymer, a polyamide resin, a polycarbonate resin, various resins such as a polystyrene resin, and a laminate in which a metal foil such as aluminum is used as an adherend are employed. In this case, since the olefin polymer has poor adhesion to these adherends, a modified olefin polymer modified by adding an unsaturated carboxylic acid or an anhydride thereof is used as the olefin polymer. I have.

As the modified olefin polymer, the olefin polymer is prepared in a molten state, a solution state, or an aqueous suspension state, together with an unsaturated carboxylic acid or an anhydride thereof, in the presence of a radical generator under a graft reaction condition. Is known, the modified olefin polymer obtained by any of the methods, the addition efficiency of the unsaturated carboxylic acid or its anhydride is low, therefore, the addition amount does not increase, while By increasing the amount of the unsaturated carboxylic acid or its anhydride or the amount of the radical generator used, the added amount can be increased, but the residual amount of the unreacted unsaturated carboxylic acid or its anhydride increases, Fish eyes and the like due to gelation of the terpolymer are generated, and furthermore, the resulting modified olefin polymer A post-treatment method for removing unreacted unsaturated carboxylic acids or anhydrides thereof is also known, but this often involves generation of fish eyes and deterioration of hue, and therefore, adhesion to an adherend and At present, a modified olefin-based polymer which can satisfy market requirements in terms of surface appearance has not been obtained.

[0005] In particular, in the above-mentioned melt-kneading method, in which the olefin polymer can be easily modified by extruding the olefin polymer in a molten state and kneading it with an extruder or the like without using a solvent, etc. Among the coalesced, the above-mentioned problem was remarkable in an ethylene-based polymer which is a cross-linked type and has no decrease in molecular weight, compared to a propylene-based polymer which is decomposable with respect to a radical generator and has a decrease in molecular weight .

As a method for producing a modified olefin polymer having excellent adhesive strength and surface appearance, for example, in the above-mentioned melt-kneading method, a molten olefin polymer containing a functional monomer such as maleic anhydride and a radical generator is used. A method of adding an antioxidant to an olefin polymer (JP-A-7-216032)
No. reference. ), A method of supplying the other to a molten olefin polymer containing one of a radical polymerizable monomer such as maleic anhydride and a radical polymerization initiator (see JP-A-7-316239). A method of supplying a solution of an unsaturated carboxylic acid and a radical generator dissolved in a solvent to an olefin-based polymer (Japanese Patent No. 28
See JP 87747. ) Have been proposed, but according to the study of the present inventors, although some improvement is recognized in each method, the adhesive force and surface appearance are improved enough to sufficiently satisfy the market requirements. It turns out that it is not what you can do.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned prior art. Therefore, the present invention provides a laminate having excellent adhesion to an adherend and excellent surface appearance. An object of the present invention is to provide a method for producing an unsaturated carboxylic acid or an anhydride-modified ethylene polymer thereof, which can be obtained.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have supplied unsaturated carboxylic acids or their anhydrides to ethylene polymers at a specific temperature in a specific form. By doing so, the present inventors have found that the above objects can be achieved, and have reached the present invention, that is, the present invention provides an ethylene polymer and an unsaturated carboxylic acid or an anhydride thereof in a graft reaction condition in the presence of a radical generator. To produce a modified ethylene polymer by using a twin-screw extruder having two or more raw material supply ports and one or more vent ports, using an unsaturated carboxylic acid or an anhydride thereof at 100 to 250 ° C. At a temperature of 200 to 2 in a kneading section.
The unsaturated carboxylic acid or its anhydride was added to the ethylene-based polymer by melt-kneading at 70 ° C., and then subjected to a devolatilization treatment from a vent port. The gist of the present invention is a method for producing a modified ethylene polymer which is melt-extruded at three times or more the 99.9% decomposition time of the radical generator at the polymer temperature.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The process for producing a modified ethylene polymer according to the present invention comprises subjecting an ethylene polymer and an unsaturated carboxylic acid or an anhydride thereof to a graft reaction condition in the presence of a radical generator. This is a method for producing a polymer, and as the ethylene polymer used herein, for example, a homopolymer of ethylene, ethylene, propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1
Other α-olefins having about 3 to 18 carbon atoms such as -pentene, 1-hexene, 4-methyl-1-hexene, 1-heptene, 1-octene, 1-decene, and 1-octadecene; vinyl acetate; (Meth) acrylic acid (where,
“(Meth) acryl” means acryl and methacryl. And copolymers with (meth) acrylic acid esters, and the like. Specific examples thereof include, for example, ethylene homopolymers such as low-, medium-, high-density polyethylene (branched or linear), ethylene- Propylene copolymer, ethylene-1-butene copolymer, ethylene-propylene-
1-butene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-heptene copolymer, ethylene-1-octene copolymer, ethylene-acetic acid Vinyl copolymer, ethylene-
(Meth) acrylic acid copolymer, ethylene-methyl (meth) acrylate copolymer, ethylene-ethyl (meth) acrylate copolymer, ethylene- (meth) acrylic acid-methyl (meth) acrylate copolymer Ethylene-based resins such as ethylene-propylene copolymer, ethylene-propylene-non-conjugated diene copolymer, ethylene-1-butene copolymer, ethylene-1-butene-non-conjugated diene copolymer And the like. Among them, in the present invention, a resin such as a branched low-density ethylene homopolymer or a linear low-density ethylene-α-olefin copolymer is preferable.

Further, the ethylene polymer has a density of 0.1.
850 to 0.950 g / cm ³ is preferable, and
190 ° C, load 2 according to JIS K7210
1. Melt flow rate measured at 18 N is 0.01 to
200 g / 10 min is preferable, and 0.1 to 100 g
/ 10 minutes is particularly preferred.

[0011] The ethylene-α-olefin copolymer includes, in particular, ethylene, 1-hexene, 4-methyl-1-hexene, 1-heptene, 1-octene and 1-hexene.
A straight chain comprising an α-olefin having 6 to 12 carbon atoms, such as decene, having a density of 0.850 to 0.915 g / cm ³ and a melt flow rate under the same conditions as described above of 0.01 to 50 g / 10 min. Ethylene-α-olefin copolymers are preferred.

Further, as the linear ethylene-α-olefin copolymer, those copolymerized in the presence of a conventionally used Ziegler-Natta catalyst or the like,
It is preferable that the copolymer is copolymerized in the presence of a metallocene catalyst.

In addition, ethylene-α using a metallocene catalyst
-Olefin copolymers are described, for example, in JP-A-58-193.
No. 09, No. 59-95292, No. 60-35005
Nos. 60-35006, 60-35007, 60-35008, 60-35009, 61-
130314, JP-A-3-16388,
EP-A-420436, U.S. Pat. No. 505
No. 5438, and International Publication WO 91/04257.
No., etc., using a metallocene-based catalyst, particularly a metallocene-alumoxane-based catalyst, or, for example,
For example, a gas phase method, a slurry method, a solution method, a high pressure ionic weight, or the like may be used, using a catalyst described in International Publication WO92 / 01723 or the like, which comprises a metallocene compound and a compound that reacts with the compound to form a stable anion. It can be produced by a polymerization method such as a synthesis method, preferably a high pressure ionic polymerization method.

The unsaturated carboxylic acids or anhydrides used herein include, for example, (meth) acrylic acid, crotonic acid, isocrotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid And unsaturated carboxylic acids such as tetrahydrophthalic acid, or anhydrides thereof. Of these, unsaturated dicarboxylic acids or anhydrides thereof, particularly maleic acid or anhydride thereof, are preferable.

The radical generator used here is a temperature at which a half-life is 1 minute (1 minute half-life temperature) from the viewpoint of the addition reactivity of an unsaturated carboxylic acid or its anhydride to an ethylene polymer. Is preferably in the range of 150 to 200 ° C., specifically, for example,
Di-t-butyl peroxide (1 minute half-life temperature 19
3 ° C.), t-butylcumyl peroxide (178
° C), dicumyl peroxide (171 ° C), 2,5
-Dimethyl-2,5-di (t-butylperoxy) hexane (179 ° C), 2,5-dimethyl-2,5-di (t-butylperoxy) hexine-3 (193 ° C)
Dialkyl peroxides, such as t-butyl peroxyacetate (159 ° C), t-butylperoxylaurate (165 ° C), t-butylperoxybenzoate (166 ° C), di-t-butyldioxy Peroxyphthalate (159 ° C), t-butylperoxyisopropyl carbonate (158 ° C), 2,5-dimethyl-2,5-di (benzoylperoxy) hexane (1
Peroxyesters such as 2,5-dimethyl-2,5-di (benzoylperoxy) hexine-3 (162 ° C), methyl ethyl ketone peroxide (171 ° C), cyclohexanone peroxide (17 ° C).
4 ° C.) and the like, and two or more of these may be used in combination.

Among them, at a kneading temperature (polymer temperature in a kneading section described later) in a twin-screw extruder described later used for modification, a half-life of 0.1 to 10 times the residence time of the ethylene polymer is obtained. Organic peroxides are preferred, and specifically, for example, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, Dialkyl peroxides such as 5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 are particularly preferred.

The method for producing a modified ethylene polymer of the present invention uses a twin-screw extruder having two or more raw material supply ports and one or more vent ports, wherein the unsaturated carboxylic acid or its anhydride is used. Into the ethylene polymer at a temperature of 100 to 250 ° C. in a fluid state, and melt kneading the polymer at a kneading unit at a temperature of 200 to 270 ° C. to convert the unsaturated carboxylic acid or the anhydride thereof into the ethylene. It is added to the system polymer.

The twin-screw extruder is generally provided with a barrel provided with a raw material supply port, a vent port, and a jacket, and is provided with a plurality of grooves on its surface, and rotates in the same direction or in different directions. Consists of two screws, and a die attached to the extruder tip, in the middle of the screws,
A kneading unit constituted by a plurality of kneading disks is provided in a form that meshes with each other or a form that does not mesh with each other, and as an extruder having a high kneading function,
For example, it is commercially available as "TEXα" series from Japan Steel Works, Ltd., and as "TEM-SS" series from Toshiba Machine Co., Ltd.

The twin-screw extruder according to the present invention includes
It has three material supply ports and two or three vent ports, the ratio of screw length (L) to screw diameter (D) (L / D) is 10 to 50, the rotation direction is the same direction, and the meshing form However, a partially or completely meshing type is preferable.

In the present invention, the unsaturated carboxylic acid or its anhydride is added to the twin-screw extruder in an amount of 100 to 25.
It is essential to press-fit the ethylene-based polymer at a temperature of 0 ° C. in a fluid state.

As the fluid form of the unsaturated carboxylic acid or its anhydride, specifically, for example, the unsaturated carboxylic acid or its anhydride is heated to a melting point or higher in a molten state or dissolved in a solvent. Although a form such as a solution state may be mentioned, a molten state is preferable because a solvent is not used.

The injection of the fluid unsaturated carboxylic acid or its anhydride into the twin-screw extruder is usually performed by a plunger pump or the like, and the pressure at that time is determined by the unsaturated carboxylic acid or its anhydride. In order to prevent vaporization in the extruder, and thus the occurrence of fish eyes or the like due to long-term residence in the extruder, it is preferable to use a saturated vapor pressure of the unsaturated carboxylic acid or anhydride used which is equal to or higher than the saturated vapor pressure. .

The injection of the fluid unsaturated carboxylic acid or its anhydride into a twin-screw extruder is carried out at a decomposition rate of 5-7.
It is preferable to use an ethylene-based polymer containing a radical generator of 0%, for example, as a specific method, for example, through the first raw material supply port of a twin-screw extruder and an ethylene-based polymer. A method of supplying an unsaturated carboxylic acid or an anhydride thereof from the second raw material supply port while supplying the generator, or a method of supplying an ethylene polymer from the first raw material supply port and supplying the radical generator from the second raw material supply port And a method of supplying an unsaturated carboxylic acid or an anhydride thereof from the third raw material supply port.

Further, in the method for producing a modified ethylene polymer of the present invention, after the unsaturated carboxylic acid or its anhydride is press-fitted into a twin-screw extruder in a fluid state, the polymer temperature in the kneading section is set to 200 to 270. ℃ and melt kneading, then
After the devolatilization treatment is performed from the vent port, the retention time of the ethylene polymer in the twin-screw extruder is set to three times or more of the 99.9% decomposition time of the radical generator at the polymer temperature in the kneading section. Extrusion is required.

Here, the devolatilization from the vent port is preferably performed at 0.1 to 85 k from the vent ports provided at a plurality of locations.
It is preferable to gradually increase the degree of pressure reduction in the pressure reduction range of Pa,
The residence time of the ethylene polymer is set in the range of 0.1 to 10 minutes.

As described above, the temperature of the ethylene-based polymer at the time of supplying the unsaturated carboxylic acid or its anhydride, the form and method of supplying the unsaturated carboxylic acid or its anhydride, and the temperature of the polymer at the kneading section ( Kneading temperature), devolatilization of the kneaded material, and the residence time of the ethylene polymer, if the above requirements are not satisfied, the resulting modified ethylene polymer is an unsaturated carboxylic acid or an anhydride thereof. Is insufficient, resulting in inferior adhesion to the adherend, and / or an increase in fish eyes or the like due to gel or the like, resulting in inferior surface appearance.

In the method for producing a modified ethylene polymer of the present invention, the amount of the unsaturated carboxylic acid or anhydride thereof is 0.1 to 10 parts by weight based on 100 parts by weight of the ethylene polymer. Preferably in parts by weight,
The content is more preferably 0.2 to 1.0 part by weight.
It is particularly preferred to be 5 to 0.5 parts by weight. If the amount of the unsaturated carboxylic acid or its anhydride is less than the above range, the amount of the unsaturated carboxylic acid or its anhydride in the obtained modified ethylene polymer becomes insufficient,
Adhesion to the adherend tends to be inferior, whereas, when the amount exceeds the above range, the content of the unreacted unsaturated carboxylic acid or anhydride thereof in the obtained modified ethylene-based polymer is increased, and thus the adherence to the adherend is also increased. Adhesive strength tends to be poor.

The amount of the radical generator used is such that the amount of the radical generator used (A) is 1/30 ≦ A / A with respect to the amount of the unsaturated carboxylic acid or its anhydride (B).
It is preferable to set the range of B ≦ １ ／, and 1/16 ≦ A /
It is particularly preferred that B ≦ １ ／. When the amount of the radical generator used is less than the above range, the amount of the unsaturated carboxylic acid or anhydride added in the obtained modified ethylene polymer is insufficient, and the adhesive strength to the adherend tends to be poor. If the content exceeds the above range, the resulting modified ethylene-based polymer tends to have fish eyes or the like due to gelation or the like, and the surface appearance tends to be poor.

In the method for producing a modified ethylene polymer according to the present invention, the effects of the present invention are not impaired except for the ethylene polymer, the unsaturated carboxylic acid or its anhydride, and the radical generator. Within the range, other thermoplastic resins and rubbers, and antioxidants, light stabilizers, ultraviolet absorbers, nucleating agents, neutralizing agents, antistatic agents, lubricants, antiblocking agents, flow improvers, plasticizers A release agent, a flame retardant, a colorant, a dispersant, a filler, and the like may be used.

The ethylene polymer, or the radical generator, or other resins, rubbers, additives, and the like used as required, are supplied to the twin-screw extruder before being supplied.
Usually, the mixture is uniformly mixed by a tumbler blender, ribbon blender, V-type blender, Henschel mixer or the like.

The modified ethylene polymer obtained by the production method of the present invention is characterized in that the ratio of the melt flow rate of the modified ethylene polymer to the melt flow rate under the above-mentioned conditions of the ethylene polymer before modification is 0. And the added amount of the unsaturated carboxylic acid or its anhydride unit is 0.1 to 0.5% by weight, and the amount of the unreacted unsaturated carboxylic acid or its anhydride is 0.1 to 0.5% by weight. Content 3
0 ppm or less, and the amount of fish eyes is 10 / g
It can be:

The modified ethylene-based polymer obtained by the production method of the present invention is usually subjected to a conventional extrusion laminating method with or without an anchor coat agent on an adherend by a conventionally known method. It is suitably used as a laminate by extrusion lamination, coextrusion lamination, coextrusion with an adherend resin, or heat fusion to an adherend resin in the form of a film in advance.

Examples of the adherend include various resins such as polyamide resin, polyester resin, saponified ethylene-vinyl acetate copolymer, polycarbonate resin, polystyrene resin, acrylic resin, and polyolefin resin. Examples include foils and plates of thermoplastic resin, metal such as aluminum, copper, lead, and stainless steel, and paper.

[0034]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention.

Example 1 A twin-screw extruder (32 mm screw diameter, L / D42.L) having the same direction of rotation of a twin screw, a completely meshing type, and having three raw material supply ports and two vent ports.
5, "TEX30" manufactured by Nippon Steel Works, Ltd.), using a linear low-density ethylene-α-olefin copolymer resin (density 0.
(915 g / cm ³ , melt flow rate 2 g / 10 min)
100 parts by weight and 2,5-dimethyl-2,5-di (t-
After mixing with 0.05 parts by weight of butylperoxy) hexane (“Perhexa 25B” manufactured by NOF Corporation) using a Henschel mixer, the mixture was supplied to the twin-screw extruder from the first raw material supply port, and subsequently, the resin immediately below 0.3 parts by weight of molten maleic anhydride heated to about 70 ° C. was injected with a plunger pump at a pressure of 1 MPa from a second raw material supply port set at a temperature of 170 ° C., and a resin temperature of 250 ° C. The maleic anhydride was added to the ethylene-α-olefin copolymer resin by melt-kneading in the kneading section set at, and then the first vent at a reduced pressure of 1.3 kPa, and a pressure of 1.3 kPa. After devolatilization from the second vent port at a reduced pressure, the ethylene-α-olefin copolymer resin was melt-extruded into strands so that the residence time in the extruder was 20 seconds, and then cooled. By solidifying and cutting, pelletized maleic anhydride-modified ethylene-α
-An olefin copolymer resin was produced.

Here, the residence time of the resin to the second raw material supply port to which maleic anhydride was supplied was 10 seconds, and the decomposition rate of the radical generator at the maleic anhydride supply position was calculated by the following method. Was 5%. Further, the 99.9% decomposition time of the radical generator at the resin temperature of 250 ° C. in the kneading section, calculated by the following method, was 2 seconds, and therefore, the residence time of the resin, 20 seconds, was 10 times that. .

Decomposition rate of radical generator One-minute half-life temperature of radical generator T _1/2 ° C. (179
° C) and Arrhenius equation [k = Ae
xp (-E / RT), where k is the rate constant, A is the frequency factor, E is the activation energy, R is the gas constant, and T is the absolute temperature. ], The frequency factor A, the temperature of the resin when maleic anhydride was supplied, T ° C. (170 ° C.), and the residence time t ₁ second (10 seconds) of the resin until maleic anhydride was supplied. ), The decomposition rate (%) of the radical generator at the maleic anhydride supply position was calculated by the following formulas (2) and (3). A = {(ln2) / 60 } / exp {-E / R (T 1/2 +273)} (1) B = exp [t 1 Aexp {-E / R (T + 273)}] (2) a radical generator Decomposition rate (%) = 1- (1 / B) (3)

From the temperature T.degree. C. (250.degree. C.) of the resin in the kneading section for the 99.9% decomposition time of the radical generator,
(4) [In the formula (4), C and D are constants specific to the radical generator. In the case of “Perhexa 25B”, according to the catalog of the manufacturer Nippon Yushi, C = −0.076,
D = 17.44. ], The half-life t _1/2 seconds of the radical generator at the temperature is determined, and the half-life t _1/2
From the second, 99.9% of the radical generator is obtained by the following formula (5).
The decomposition time (second) was calculated. lnt _1/2 = CT + D (4) 99.9% decomposition time (sec) = 3t _1/2 / log2 (5)

The obtained maleic anhydride-modified ethylene-α
-For the olefin copolymer resin, by the method shown below, the melt flow rate, the addition amount and the addition rate of maleic anhydride units, the content of unreacted maleic anhydride, and
The amount of fish eyes was measured and the results are shown in Table 1. Melt flow rate 190 ° C, load 2 according to JIS K7210
1. Measured at 18N.

Addition amount and addition rate of maleic anhydride unit From the modified resin pellets, a thickness of 100 μm was obtained by hot pressing.
Was prepared, the carbonyl group absorption was measured by an infrared absorption spectrum, and the total amount of maleic anhydride in the modified resin was determined from a separately prepared calibration curve. On the other hand, after dissolving the modified resin pellets in boiling xylene, the precipitate was reprecipitated in acetone, and the precipitate was filtered and dried in a vacuum at 80 ° C. for 6 hours. The addition amount of maleic anhydride units in the sample was determined, and the addition ratio to the total amount of maleic anhydride was calculated.

About 20 g of the unreacted maleic anhydride-containing modified resin pellets were precisely weighed and subjected to reflux extraction for 8 hours using 100 ml of acetone as an extraction solvent. The extract was air-dried and then 0.1 M sodium dihydrogen phosphate (pH 2). ) 5
After dissolving the filtrate in 0.4 ml, the filtrate filtered with a 0.45 μm filter was subjected to high performance liquid chromatography (“HPLC8020 series” manufactured by Tosoh Corporation), and the column was “TSK-Gel ODS-120T” manufactured by Tosoh Corporation, 150
mm × 4.6 mm, particle size 5 μm. ).

[0042] From fisheye amount modified resin pellets, the thickness at a molding temperature of 170 ° C. 30.mu.
m, after inflation molding a film, cut out a test piece of 100 cm ² from this film,
The number of fish eyes having a size of 0.2 to 0.5 mm was counted, and the number was converted into the number per unit weight g.

Further, the adhesive strength of the obtained maleic anhydride-modified ethylene-α-olefin copolymer resin to an adherend was measured by the following method.
It was shown to.

The adhesive strength modified resin to the adherend and the saponified ethylene-vinyl acetate copolymer were
Molding temperature 190 ° C, molding speed 50m / min or 70m
/ Min, and a two-layer laminated film of a modified resin layer of 35 μm and a saponified ethylene-vinyl acetate copolymer layer of 35 μm was blown under the conditions of an air gap of 250 mm. From this, a test piece having a width of 10 mm and a length of 120 mm was cut out and subjected to JIS K68 using a Shopper type tensile tester.
In accordance with No. 54, a T-shaped peeling test was performed at a peeling speed of 500 mm / min to measure a peeling strength.

Example 2, Comparative Examples 1-4 The supply position of maleic anhydride, the residence time of the resin to the raw material supply port for supplying maleic anhydride, the resin temperature at the raw material supply port, the supply form of maleic anhydride, Except that any of the resin temperature of the kneading portion and the presence or absence of devolatilization treatment from the vent port was changed as shown in Table 1, the same as in Example 1,
A maleic anhydride-modified ethylene-α-olefin copolymer resin was produced, and the melt flow rate, the amount and rate of addition of maleic anhydride units, the content of unreacted maleic anhydride, and the amount of fisheye were measured. Further, the adhesive strength to the adherend was measured, and the results are shown in Table 1.

[0046]

[Table 1]

[0047]

According to the present invention, it is possible to produce an unsaturated carboxylic acid or an anhydride-modified ethylene polymer thereof, which is capable of obtaining a laminate having excellent adhesion to an adherend and excellent surface appearance. A method can be provided.

 ────────────────────────────────────────────────── ─── Continued on front page F term (reference) 4J100 AA02P AA03Q AA04Q AA07Q AA09Q AA15Q AA17Q AA19Q AG04Q AL03Q BA16H BC55H CA01 CA04 FA03 FA28 FA47 HA57 HC30 HC36

Claims (7)

[Claims] 1. A method for producing a modified ethylene polymer by subjecting an ethylene polymer and an unsaturated carboxylic acid or an anhydride thereof to a graft reaction condition in the presence of a radical generator, wherein two or more raw material supply ports are provided. And using a twin-screw extruder having one or more vent ports, pressurize the unsaturated carboxylic acid or its anhydride into an ethylene-based polymer at a temperature of 100 to 250 ° C in a fluid state, and polymer temperature in the kneading section. Is added to the ethylene-based polymer by melt-kneading at 200 to 270 ° C. and then subjected to devolatilization treatment from the vent port, and the residence time of the ethylene-based polymer in the extruder And subjecting it to melt extrusion at a temperature at least three times the 99.9% decomposition time of the radical generator at the polymer temperature. 2. An ethylene polymer and a radical generator are supplied from a first raw material supply port of a twin-screw extruder, or
An ethylene-based polymer is supplied from a raw material supply port, a radical generator is supplied from a second raw material supply port, and an unsaturated carboxylic acid or an anhydride thereof is injected from a raw material supply port after the second raw material supply port. 3. The method for producing a modified ethylene polymer according to item 1. 3. The method according to claim 1, wherein the injection of the unsaturated carboxylic acid or the anhydride thereof is performed on an ethylene polymer containing a radical generator having a decomposition rate of 5 to 70%. A method for producing a modified ethylene polymer. 4. The modified product according to claim 1, wherein the unsaturated carboxylic acid or its anhydride in a fluid state is a molten state in which the unsaturated carboxylic acid or its anhydride is heated to a melting point or higher. A method for producing an ethylene polymer. 5. The amount of the unsaturated carboxylic acid or anhydride thereof used is based on 100 parts by weight of the ethylene polymer.
The method for producing a modified ethylene-based polymer according to any one of claims 1 to 4, wherein the amount is 0.1 to 10 parts by weight. 6. The use amount of the radical generator (A) is in the range of 1/30 ≦ A / B ≦ １ ／ with respect to the use amount (B) of the unsaturated carboxylic acid or its anhydride. Item 6. The method for producing a modified ethylene polymer according to any one of Items 1 to 5. 7. The method for producing a modified ethylene polymer according to claim 1, wherein the ethylene polymer is an ethylene homopolymer or an ethylene-α-olefin copolymer.