JP2001072811A - Resin composition for lamination film and lamination film - Google Patents

Abstract

(57) [Problem] To provide a resin composition and a lamination film which are less likely to cause surging during film formation and have good moldability. (A) A melt flow rate is 15
４０40 (g / 10 minutes) and a weight average molecular weight (M
w) and the number-average molecular weight (Mn) ratio (Mw / Mn) is 1
75 to 94.5% by weight of polypropylene which is 0 or less,
(B) 5 to 15% by weight of a high-pressure low-density polyethylene having a melt flow rate of 3 to 12 (g / 10 minutes), and (C) a melt flow rate of 0.1 to 30 (g / 10 minutes).
A) the amorphous α-olefin copolymer 0.5 to 1
0% by weight of the resin composition for a lamination film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition for a film and a lamination film used when laminating a synthetic resin to a substrate.

[0002]

2. Description of the Related Art It is widely practiced to protect a surface or decorate a surface by laminating a film on a surface of a base material made of a material such as metal, paper, wood, plastic and the like. At this time, a polypropylene film with transparency, chemical resistance and heat resistance is excellent as a lamination material, but in order to increase transparency and improve moldability, high-pressure low-density polyethylene is mixed with polypropylene. That is being done. However, when a film is actually formed with the resin composition during the lamination operation, the film tends to have thickness irregularities called surging, and as a result, the mechanical strength and light transmittance may vary from place to place. This surging phenomenon refers to regular thickness fluctuations occurring in the direction in which the film is being taken. Although the cause is not clear, it is necessary to avoid the occurrence in commercial products as much as possible.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lamination film-forming resin composition and a lamination film which are less likely to cause surging and have good moldability.

[0004]

That is, the present invention provides:
(A) Melt flow rate is 15 to 40 (g / 10 minutes)
And a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of not more than 10 is 75 to 94.5% by weight, and (B) the melt flow rate is 3 to 12 ( g / 10 min) of a high-pressure method low-density polyethylene of 5 to 15% by weight, and (C) an amorphous α-olefin copolymer having a melt flow rate of 0.1 to 30 (g / 10 min) 0 0.1 to 10% by weight. Further, the present invention relates to a lamination film produced from the above resin composition.

The above-mentioned amorphous α-olefin copolymer is an ethylene / propylene copolymer, an ethylene / 1-butene copolymer, a propylene / ethylene copolymer or a propylene / 1-butene copolymer. It is preferable that it is an ethylene / propylene copolymer or a propylene / 1-butene copolymer.

[0006]

Next, the constitution of the resin composition and the film thereof according to the present invention will be specifically described. [Polypropylene] As the polypropylene used in the present invention, ordinary polypropylene can be used, and in particular, a random copolymer of propylene and another α-olefin is preferable, and the α-olefin structural unit is 0.1 to 10, preferably, It is desirable to contain it in the range of 0.5 to 7 mol%. Here, the α-olefin is an olefin having 2 to 20 carbon atoms other than propylene, for example, ethylene,
-Butene, 1-pentene, 1-hexene, 4-methyl-
Examples thereof include 1-pentene, 1-octene and 1-decene, and these olefins can be used alone or in combination of two or more. Among them, ethylene and 1-butene are preferred. Such a polypropylene can be produced using a stereoregular olefin polymerization catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst.

This polypropylene is ASTM D-1
The melt flow rate (MFR) measured at 230 ° C. under a load of 2.16 kg according to 238 is 15 to 40,
Preferably it is 20 to 30 (g / 10 minutes). When the MFR is within this range, a film having good film formability and excellent mechanical strength such as tensile strength can be obtained.

In particular, this polypropylene has a ratio (Mw / Mw) between the weight average molecular weight (Mw) and the number average molecular weight (Mn).
n) is desirably 10 or less, preferably 1.5 to 7. The value of Mw / Mn is usually a measure of the molecular weight distribution. If a polypropylene having such a Mw / Mn value is used, a film having good transparency and low stickiness can be obtained.

The weight average molecular weight (Mw) and the number average molecular weight (Mn) are measured by gel permeation chromatography (GPC). For GPC measurement, for example, GPC-150C manufactured by Millipore Co., Ltd. was used, and TSK GMH HT (column size: diameter 7.
8 mm, length 600 mm), column temperature 140 ° C., moving layer o-dichlorobenzene, sample concentration 0.1% by weight, moving speed 1.0 (ml / min), and the measurement results were converted into standard polystyrene. You can ask.

[Amorphous α-olefin copolymer] The amorphous α-olefin copolymer usable in the present invention is an amorphous α-olefin copolymer having an α-olefin having 2 to 10 carbon atoms. Is a copolymer having a rubber-like property. In the present invention, a so-called low-crystalline polymer having a crystallinity of 25% or less as measured by an X-ray diffraction method is also included in the amorphous polymer. The amorphous α-olefin-based copolymer contributes to the prevention of surging of the lamination film and also to the improvement of the impact resistance of the film.

Representative examples of the copolymer include ethylene or propylene as a main component, one or more other α-olefins having 2 to 10 carbon atoms as a secondary component, and a diene monomer if necessary. Are copolymerized in a small amount.

In the copolymer containing ethylene as a main component, 75 to 95, preferably 75 to 90 mol% of ethylene constituent units and 5 to 25, preferably 10 to 25 mol% of α-olefin other than ethylene are required. May be contained in an amount of 2 mol% or less, preferably 1 mol% or less. As such an ethylene copolymer, ethylene
Propylene copolymer, ethylene / 1-butene copolymer,
Ethylene / 4-methyl-1-pentene copolymer, ethylene / 1-hexene copolymer, ethylene / 1-octene copolymer, ethylene / propylene / dicyclopentadiene copolymer, ethylene / propylene / 5-ethylidene- 2-
Norbornene copolymer, ethylene propylene 1,6
-Hexadiene copolymer and the like. Among these, an ethylene / propylene copolymer and an ethylene / 1-butene copolymer are particularly preferred.

The copolymer containing propylene as a main component has a propylene constitutional unit of 70 to 95, preferably 72 to 90.
Mol%, 5 to 30 α-olefins other than propylene,
Preferably, the content is 10 to 28 mol%. Examples of such a propylene-based copolymer include a propylene / ethylene copolymer and a propylene / 1-butene copolymer.

The melt flow rate (MFR) of the amorphous α-olefin copolymer is ASTM D-123.
The value measured at 230 ° C. under a load of 2.16 kg is 0.1 to 30, preferably 0.5 to 20 (g / 1
0 minutes). When the value of the MFR is within this range, the melt tension of the molten resin is increased during film formation to promote the formation of a film having a uniform thickness, and it is effective for preventing the occurrence of surging of the film.

The α-olefin copolymer comprises a vanadium catalyst comprising a soluble vanadium compound and an organic aluminum halide, or a metallocene compound such as a zirconium compound coordinated with cyclopentadiene and an organic aluminum oxy compound. It can be produced by copolymerizing α-olefins in the presence of a metallocene catalyst.

[Resin Composition] The resin composition for a lamination film according to the present invention contains 75 to 94.5, preferably 80 to 91% by weight of the above-mentioned polypropylene (A), and contains a high-pressure low-density polyethylene (B). 5 to 15, preferably 8 to 13% by weight, and the above-mentioned amorphous α-olefin-based copolymer (C) is 0.5 to 10, preferably 1 to
-7% by weight. Where (A),
The total amount of (B) and (C) is 100% by weight.

The high-pressure low-density polyethylene (B), which is one component of the resin composition, is a low-density polyethylene obtained by radical polymerization of ethylene under high pressure, and includes vinyl acetate, acrylic acid, methacrylic acid and the like. May contain a small amount of the vinyl monomer. This high-pressure low-density polyethylene conforms to ASTM D-1238, and has a temperature of 190 ° C.
2.Melt flow rate (M
FR) is preferably 3 to 12 (g / 10 minutes), and such polyethylene increases the melt tension of the molten resin and improves the film formability.

The resin composition within the above-mentioned composition range can suppress the occurrence of surging and drawdown during film formation and minimize neck-in. Furthermore, a good film without stickiness can be formed, and a film having uniform transparency, high mechanical strength, and heat resistance can be produced.

Various additives such as an antioxidant may be added to the resin composition without departing from the object of the present invention.
A weathering stabilizer, an ultraviolet absorber, a light stabilizer, an antistatic agent, a slip agent, an antiblocking agent, a hydrochloric acid absorber, a pigment and the like can be appropriately compounded.

The mixture containing the polypropylene (A), the high-pressure low-density polyethylene (B), the amorphous α-olefin-based copolymer, and the necessary additives is mixed with an extruder, a Banbury mixer, a kneader, a mixing roll, etc. Are uniformly mixed by using a conventional mixer, and a kneading operation is added if necessary, to obtain a resin composition.

[Lamination Film] The lamination film according to the present invention is a film produced from the resin composition described above and used for lamination to a substrate. Film forming from the resin composition can be performed by melting the resin composition in a usual single-screw or twin-screw extruder, extruding through a T-die or a ring die under general extrusion conditions, and drawing off. .

As a substrate for lamination,
Any of products manufactured from metal materials such as aluminum foil and copper foil, wood such as paper and plywood, plastic films such as polyester film, polyamide film and biaxially oriented polypropylene film can be used. .

The lamination to the substrate may be performed by forming a film from the resin composition and then dry laminating, or may be performed by directly extruding the film onto the substrate. In the case of dry lamination, an adhesive such as a urethane-based adhesive may be applied to the substrate side or the film side in advance, or may be subjected to a flame treatment, an ozone treatment, a corona discharge treatment, or the like. Good.

[0024]

Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

(Examples 1 to 3) (Comparative Examples 1 and 2) First, the propylene random copolymer, high-pressure low-density polyethylene, and α-
The olefin copolymer had the physical properties described in Table 1.

[Table 1] * Measured at 230 ° C

Next, these polymers were mixed at the compounding ratios shown in Table 2, and tetrakis [methylene-3 (3,5-
Di-t-butyl-4-hydroxyphenyl) propionate] methane is 500 ppm based on the whole resin composition,
And 1000 ppm of calcium stearate were blended and kneaded in a single screw extruder to obtain pellets.

The pellets are supplied to a 65 mmφ single screw extruder, melted at a resin temperature of 290 ° C., extruded from a T-die, formed into a film having a thickness of 20 μm at a line speed of 120 m / min. A laminate was obtained. The physical properties of this film were measured, and the results are shown in Table 2.

[0028]

[Table 2] * Film could not be formed.

The physical properties were measured by the following test methods. (1) Surging: The line speed is gradually increased while the amount of resin extruded during film formation is kept constant, and the occurrence of ear fluctuation, occurrence of surging, and occurrence of film cracking are observed. The speed (m / min) was recorded, and the surging was evaluated based on the line speed.

(2) Neck-in: The difference (mm) between the die width when forming a T-die film and the film width after forming.
Indicated the neck-in situation. (2) Haze: Measured after leaving the sample at 23 ° C. for 7 days in accordance with ASTM D-1003.

(3) Blocking / Slip Properties: The blocking and slip properties of the obtained film during secondary processing were measured by the following methods, and the quality was evaluated. Blocking property: According to ASTM D-1893,
The measurement was performed under the conditions of 50 ° C., a load of 20 kg, and 7 days. Slip property: 40 in accordance with ASTM D-1894
The kinetic friction coefficient was measured at a temperature of 3 ° C. for 3 days.

[0032]

According to the present invention, since a resin composition is prepared by blending polypropylene with a high-pressure low-density polyethylene and an α-olefin copolymer, the occurrence of surging during film formation can be suppressed. Work could be advanced with good moldability. The obtained film had uniformity without thickness unevenness, and had high light transmittance and mechanical strength. Therefore, this film was suitable for lamination to metal, paper, wood, plastic products and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 23:16 23:08 23:14) (72) Inventor Kunio Eri 3 Chigusa Kaigan, Ichihara City, Chiba Pref. F term in company polymer (reference) 4F071 AA14 AA14X AA15X AA18 AA19X AA20 AA20X AA21X AA81 AA88 AC11 AC19 AH19 BA01 BB06 BC02 BC12 4F100 AK03A JA06AAK07A01A01A03B 4J002 BB032 BB043 BB111 BB121 BB143 BB153 GF00

Claims (5)

[Claims] (A) a melt flow rate of 15 to 40;
(G / 10 minutes) and 75 to 94.5% by weight of polypropylene having a ratio (Mw / Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 10 or less, (B) melt flow High-pressure low-density polyethylene having a rate of 3 to 12 (g / 10 minutes), and (C) an amorphous α- having a melt flow rate of 0.1 to 30 (g / 10 minutes). A resin composition for a lamination film, comprising 0.5 to 10% by weight of an olefin-based copolymer. 2. The method according to claim 1, wherein said polypropylene is propylene and α.
The resin composition for a lamination film according to claim 1, wherein the resin composition is a random copolymer with an olefin, and has an α-olefin content of 0.1 to 10 mol%. 3. The method of claim 1, wherein the amorphous α-olefin-based copolymer is an ethylene / propylene copolymer, an ethylene / 1-butene copolymer, a propylene / ethylene copolymer, or a propylene / 1-butene copolymer. The resin composition for a lamination film according to claim 1, wherein the resin composition is at least one polymer selected from the group consisting of coalescing. 4. The method according to claim 1, wherein the amorphous α-olefin copolymer is an ethylene / propylene copolymer or a propylene / propylene copolymer.
The resin composition for a lamination film according to claim 1 or 2, wherein the resin composition is a 1-butene copolymer. 5. A lamination film formed from the resin composition according to claim 1.