JPH0967479A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition having excellent extrusion moldability without deteriorating the excellent characteristics of high-density polyethylene by compounding a high-density polyethylene with two specific kinds of olefinic copolymers each having respective specific functional group. SOLUTION: This resin composition is produced by compounding (A) 30-99wt.% of a high-density polyethylene (preferably having a melt flow rate of 0.05-100g/10min), (B) 0.5-69.5wt.% of an olefinic polymer containing a carboxylic acid or its derivative and (C) 0.5-69.5wt.% of an olefinic polymer having a functional group (e.g. hydroxyl group) reactive with the carboxylic acid or its derivative. The component B is produced e.g. by grafting a polyolefin such as a high-density polyethylene with an unsaturated carboxylic acid such as (meth)acrylic acid or its derivative in the presence of a radical generator. The component C is produced e.g. by reacting ethylene with an unsaturated hydroxy compound such as hydroxyethyl (meth)acrylate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition, and more particularly to a resin composition excellent in melt molding, particularly extrusion molding such as laminate, film and blow sheet.

[0002]

2. Description of the Related Art High-density polyethylene resin (hereinafter HDPE)
Is also widely used because it has excellent properties such as rigidity, impact resistance, breaking strength, scratch resistance, heat sealability, moisture resistance and water resistance, and is inexpensive. For example, it is widely used as a film for agriculture and general packaging, and is also laminated with paper by extrusion lamination molding, and is used for release paper, printing paper, thermal transfer paper, process paper for manufacturing artificial leather, etc. Besides, it is used as a packaging material for packaging by laminating with a biaxially oriented polypropylene film, a polyester film, a polyamide film, an aluminum foil and the like. Furthermore, bottles made by blow molding,
It is also used in hollow containers such as bag-in-boxes. The HDPE having such characteristics generally has a small viscosity or tension when melted at a high temperature and has a drawback that it is not sufficiently suitable for extrusion molding at a high temperature such as laminate molding.

In the case of laminate molding, it is generally necessary to carry out molding at a high temperature of about 270 ° C. to 300 ° C. in order to impart adhesiveness to paper or a film of polypropylene, polyester, polyamide or the like. However, HD
Since the melt tension of PE is small, the melt film is unstable at such temperatures, and fluctuations in width and thickness easily occur.
Extrusion lamination molding was very difficult with PE alone. Various methods have been devised to solve this problem. For example, there is a method of blending a low density polyethylene produced by a high pressure method and having a wide molecular weight distribution. According to this method, the melt film is stable, and extrusion laminate molding can be stably performed in a wide range of molding conditions. However, this method has a problem that the high rupture strength and the decrease in rigidity, which are characteristics of HDPE, are caused. Moreover, the drawbacks that the high-speed moldability is not yet sufficient and the neck-in is significantly larger than that of low-density polyethylene cannot be solved.

On the other hand, even in blow molding, since the melt tension is small, the parison is unstable and it is difficult to obtain a large molded product. HDPE having low fluidity is used to improve this, but the fact is that it is not a fundamental improvement in moldability due to the drawbacks such as uneven thickness of the molded product.

[0005]

As described above, the HDP
E has excellent properties such as rigidity, impact resistance, rupture strength, scratch resistance, moisture resistance and water resistance, but has a low melt viscosity or melt tension, so film forming, laminate molding, blow molding, etc. There is a drawback that the extrusion moldability is not sufficient. In view of such circumstances, it is an object of the present invention to provide a resin composition having excellent extrusion moldability without impairing the excellent properties of HDPE.

[0006]

Means for Solving the Problems As a result of studies to solve the above problems, the present inventors achieved the above object by using HDPE in combination with an olefin polymer having a specific functional group. The present invention has been completed, and the present invention has been completed based on this finding. That is, the present invention relates to (A) high density polyethylene 30 to 99% by weight (B) olefin polymer containing carboxylic acid or its derivative 0.5 to 69.5% by weight (C) carboxylic acid or its derivative It is a resin composition comprising 0.5 to 69.5% by weight of an olefin polymer having a functional group capable of controlling. Hereinafter, the present invention will be described specifically.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION HDPE, which is the component (A) used in the present invention, is a homopolymer of ethylene and is generally produced by using a catalyst such as a Ziegler catalyst, a metallocene catalyst and a Phillips catalyst. Generally, it is produced by the medium / low pressure method, but it can also be produced by the high pressure method, the gas phase method, the solution method,
It is manufactured by any of the slurry methods. Melt flow rate (measured according to JIS K6758, MF
(Also referred to as R) is generally 0.01 to 200 g / 10 minutes, preferably 0.05 to 100 g / 10 minutes. When the MFR is less than 0.01, the high-speed moldability is remarkably deteriorated and a practical production rate cannot be obtained. When the MFR exceeds 100, the stability of the molten resin film is significantly deteriorated and a surging phenomenon occurs, which makes stable molding difficult.

The olefin polymer having the carboxylic acid or its derivative which is the component (B) used in the present invention can be obtained mainly by a copolymerization method or a graft method. Examples of the olefin-based polymer containing a carboxylic acid or a derivative thereof produced by a copolymerization method include a multi-component copolymer of a compound copolymerizable with ethylene. Examples of the compound capable of copolymerization include unsaturated carboxylic acids or derivatives thereof, and specifically, α, β-, such as (meth) acrylic acid.
Unsaturated carboxylic acids, α, β-unsaturated carboxylic acid metal salts such as sodium (meth) acrylate, α, β-unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid and isocrotonic acid An acid or its anhydride etc. are mentioned. These compounds may be used as a mixture of two or more kinds in a copolymer with ethylene.
Further, these olefin polymers may be used in combination of two or more kinds.

In order to obtain an olefin polymer containing a carboxylic acid or a derivative thereof by graft modification, it is common to produce it by reacting a polyolefin, a radical generator and a modifying compound in a molten or solution state. is there. Examples of the graft-modified polyolefin include high-pressure low-density polyethylene and linear low-density polyethylene (LLDP).
E), high density polyethylene, polypropylene, propylene-ethylene copolymer, propylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid ester copolymer, etc., alone or in combination of two or more. A mixture of The graft amount of the unsaturated carboxylic acid or its derivative is usually 0.01 to 3% by weight, preferably 0.03 to 1.5% by weight, and more preferably 0.05 to 1.0% by weight. is there. If the graft amount of the unsaturated carboxylic acid or its derivative is less than 0.01% by weight, the extrusion moldability, which is the object of the present invention, cannot be improved.
Further, if it exceeds 4% by weight, a large amount of gel component is generated to cause problems in appearance, and, for example, in the case of laminate molding,
High-speed moldability is deteriorated, which is not preferable.

The type of radical generator is not particularly limited, but organic peroxides are generally used, and among them, dicumyl peroxide, especially because of its reactivity and ease of handling.
2,5-Dimethyl-2,5-bis (t-butylperoxy) hexane, 1,3-bis (2-t-butylperoxyisopropyl) benzene, benzoyl peroxide and the like are mentioned as useful specific examples.

As the modifying compound, an unsaturated compound similar to the above-mentioned compound copolymerizable with ethylene is used.

The component (C) used in the present invention is an olefin polymer having a functional group capable of reacting with a carboxylic acid or its derivative. Examples of the functional group capable of chemically reacting with the carboxylic acid or its derivative include, but are not limited to, a hydroxy group, an epoxy group, an isocyanate group, and an amino group. The olefin polymer having these functional groups can be produced by a copolymerization method or a graft method, as in the case of the component (B). As a method by copolymerization, it is common to copolymerize ethylene with an unsaturated compound capable of reacting with a carboxylic acid or a derivative thereof, such as an unsaturated hydroxy compound, an unsaturated epoxy compound and an unsaturated isocyanate compound. is there. Examples of the unsaturated hydroxy compound include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, glycerol mono- or di (meth) acrylate, and trimethylolpropane di- or tri (meth) acrylate. , Ethylene glycol monoallyl ether, propylene glycol monoallyl ether, polyethylene glycol monoallyl ether, o-, m- or p-hydroxymethylstyrene, and mixtures thereof, but not exclusively. Examples of unsaturated epoxy compounds include glycidyl (meth) acrylate, allyl glycidyl ether, allyl glycidyl phthalate, vinyl cyclohexene oxide, allyl glycidyl succinate, allyl glycidyl maleate and the like. Specific examples of the unsaturated isocyanate compound include, but are not limited to, (meth) acryloxyethyl isocyanate, (meth) acryloxypropyl isocyanate, and (meth) acryloxyhexyl isocyanate.

The grafting method can be carried out by grafting an unsaturated hydroxy compound, an unsaturated epoxy compound, an unsaturated isocyanate compound or the like onto a polyolefin. The type of polyolefin and the method of grafting are the same as in the production of the component (B). The graft amount of these unsaturated compounds is usually 0.01 to 3% by weight,
It is preferably 0.03 to 1.5% by weight, and more preferably 0.05 to 1.0% by weight. If the graft amount of these unsaturated compounds is less than 0.01% by weight, the extrusion moldability, which is the object of the present invention, cannot be improved. On the other hand, if it exceeds 3% by weight, a large amount of gel component is generated to cause a problem in appearance and, for example, in the case of laminate molding, high-speed moldability is deteriorated, which is not preferable. These unsaturated compounds may be used alone or in combination of two or more.

The proportion of the component (A) in the composition of the present invention is 30 to 99% by weight, preferably 50 to 95% by weight. If it is less than 30% by weight, defects such as gels and lumps occur in the molded product and it is not economical and not preferable. 99% by weight
Exceeding this value is not preferable because the extrusion moldability is not improved.

The proportion of the component (B) in the composition of the present invention is 0.5 to 69.5% by weight, preferably 1 to 50% by weight.
It is. If it is less than 0.5% by weight, the extrusion moldability cannot be improved, and if it exceeds 69.5% by weight, defects such as gel are generated, which is not preferable.

The proportion of the component (C) in the composition of the present invention is 0.5 to 69.5% by weight, preferably 1 to 50% by weight.
It is. If it is less than 0.5% by weight, the extrusion moldability cannot be improved, and if it exceeds 69.5% by weight, defects such as gel are generated, which is not preferable.

In order to obtain the composition of the present invention, a conventionally known mixing method, for example, a method of kneading using an open roll, a Banbury mixer, a kneader, an extruder or the like may be appropriately used. The kneading temperature is usually 100
C. to 250.degree. C., preferably 130.degree. C. to 200.degree.

If desired, conventional additives such as plasticizers, lubricants, various stabilizers, antiblocking agents, antistatic agents, dyes, pigments and various fillers may be added to the composition of the present invention. Good.

[0019]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. The components used in Examples and Comparative Examples are shown below.

Component (A): A-1: MFR 18 g / 10 minutes, density 0.958 g.
/ Cm ³ HDPE A-2: MFR 5 g / 10 min, density 0.960 g /
cm ³ and is HDPE

Component (B) B-1: Modified HDPE having an MFR of 18 g / 10 minutes and a maleic anhydride graft amount of 0.4% by weight. B-2: MFR of 100 g / 10 minutes and a maleic anhydride graft. Modified HDPE B-3 with an amount of 2.0% by weight: ethylene-maleic anhydride copolymer having a MFR of 18 g / 10 min and a copolymerization rate of maleic anhydride of 2.5% by weight.

Component (C) C-1: Modified HDPE having an MFR of 15 g / 10 min and a grafting amount of 2-hydroxyethyl methacrylate of 0.4% by weight C-2: MFR of 40 g / 10 min, of glycidyl methacrylate Modified LLDP with a graft amount of 1.2% by weight
E C-3: Modified HDPE having MFR of 40 g / 10 min and a copolymerization ratio of methacryloxyethyl isocyanate of 0.5% by weight.

(Examples 1 to 7 and Comparative Examples 1 to 5) The components shown in Table 1 were mixed using a Henschel mixer for 5 minutes, and then melt-kneaded at a temperature of 170 ° C. with a vented extruder.
Pelletized. Using a 90 mmφ extruder and a laminate molding machine, each of the obtained pellets was prepared by using a biaxially stretched polypropylene film as a base material, at a temperature of 290 ° C., and an air gap of 1
It was molded by 10 mm and laminated. The drawdown property was evaluated by increasing the take-up speed at a rotation speed of the extruder of 30 rpm and measuring the speed at which film breakage occurred. Neck-in is film thickness 2
A sample molded at 0 μm and a take-up speed of 200 m / min was represented by the difference between the die width and the product width.

[0024]

[Table 1]

Example 8 Blow molding was performed using the composition of Example 1 shown in Table 1. Blow molding has an extrusion temperature of 190
And a mold temperature of 40 ° C. to obtain a hollow molded product. The appearance of the obtained hollow molded article was good.

Comparative Example 6 Blow molding was performed using the composition of Comparative Example 1 shown in Table 1. However, the parison was caused to flow and fall, and a hollow molded product could not be obtained.

Example 9 A film was formed using the composition of Example 3 shown in Table 1. Molding is performed using a film molding machine with a 200 mm wide T-die and a resin temperature of 1
A film having a thickness of 50 μm was prepared at 90 ° C. and a take-up speed of 3 m / min. The molding could be carried out without any problems. The obtained film had no gel and had a good appearance.

[0028]

According to the present invention, laminating, blowing,
A resin composition having excellent extrusion moldability such as a film or a sheet can be obtained.

Claims (4)

[Claims] 1. (A) High-density polyethylene 30-99
% By weight (B) Olefin-based polymer containing carboxylic acid or its derivative 0.5 to 69.5% by weight (C) Olefin-based polymer having functional group capable of chemically reacting with carboxylic acid or its derivative 0.5- A resin composition comprising 69.5% by weight. 2. The resin composition according to claim 1, wherein the functional group capable of chemically reacting with the carboxylic acid or its derivative is a hydroxy group. 3. The resin composition according to claim 1, wherein the functional group capable of chemically reacting with the carboxylic acid or its derivative is an epoxy group. 4. The resin composition according to claim 1, wherein the functional group capable of chemically reacting with the carboxylic acid or its derivative is an isocyanate group.