JPS61281143A - Resin composition for extrusion molding - Google Patents

Abstract

PURPOSE:To provide a resin composition obtained by compounding an ethylene copolymer with an antiblocking agent and an organic amide compound, and having remarkably well-balanced transparency, blocking property, slipperiness and printability. CONSTITUTION:The objective composition is produced by compounding (A) 100pts.(wt.) of an ethylene copolymer produced by the use of a Ziegler catalyst and having a density of 0.910-0.940g./cm<3>, a melt flow rate of 0.01-20g/10min and a comonomer content of 1-10wt% with (B) 0.01-1pt. of an antiblocking agent (e.g. silicon dioxide having an average particle diameter of >=10mu and (C) 0.01-1pt. of organic amide compounds composed of a combination of an unsaturated fatty acid amide and a saturated fatty acid amide. The component C is preferably a 3:1 mixture of a saturated fatty acid amide and an unsaturated fatty acid amide.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resin composition for extrusion molding of a linear ethylene copolymer that has an extremely good balance of transparency, blocking properties, slip properties and printability.

[Conventional technology]

Polypropylene has been known as a material for extruded products such as films with good transparency. This polypropylene film is widely used as various packaging materials because of its excellent rigidity.

However, polypropylene film is not suitable for general-purpose processing methods such as air-cooled inflation molding, and has the disadvantages of poor impact strength (especially low-temperature impact strength) and low-temperature heat sealability, so its application fields are limited. has been limited. Therefore, in the general-purpose film field, high-pressure low-density polyethylene and low-pressure high-density polyethylene, which are resins that compensate for these drawbacks, have come to be widely used.

[Problem that the invention seeks to solve]

However, although these resins are effective in compensating for the above drawbacks, they have the drawback of poor transparency.

On the other hand, linear ethylene copolymers are resins that are superior in mechanical strength such as impact strength, low-temperature impact strength, and environmental stress fracture (ESCR), as well as heat sealability and hot tack properties, which are much better than the above-mentioned general-purpose resins. . In addition to the well-known T-die molding method and water-cooled inflation molding method, methods for molding a highly transparent film of this copolymer include an air-cooled inflation molding method with a near ring for rapid cooling (for example, JP-A-53
General-purpose processing methods such as -146764) are known.

However, if a linear ethylene copolymer is simply molded into a film using these molding methods, although the film transparency is good, it is completely impractical in terms of the anti-blocking and slip properties of the film. It becomes a thing. However, this results in drawbacks such as unsatisfactory transparency and an inability to maintain a balance between physical properties, and there is also a desire to further improve the balance of physical properties.

The purpose of the present invention is to eliminate these drawbacks, and to achieve a significantly better balance of the above-mentioned qualities while maintaining the good properties of linear ethylene copolymers.

[Means for solving problems]

That is, the present invention includes each of the following components (a) to (c), and (relative to 100 parts by weight of the Al component, the BL component is 0.0 parts by weight).
This is a resin composition for extrusion molding, characterized in that the blending ratio of the c1 component is 1 to 1 part by weight and 0.01 to 1 part by weight.

(density 0 produced using al Ziegler catalyst)
．． 910-0.940 g/cA", melt flow rate 0.01-20 g/10 min and comonomer content 1-1
0% by weight of ethylene copolymer (b) Anti-blocking agent (c) Organic amide compound consisting of a combination of an unsaturated fatty acid amide and a saturated fatty acid amide The composition of the present invention is excellent in the above points, so it can be extruded. It is especially suitable for film and laminate materials.

[For production]

The above component (a) used in the present invention is produced using a Ziegler catalyst and has a density of 0.910 to 0.940 g/
cm', a melt flow rate of 0.01 to 20 g/10 min, and a comonomer content of 1 to 10% by weight. Ethylene copolymers are suitable.

Preferably, the density is 0.915-0.930 g/cm'
, a melt flow rate of 0.1 to 15 g/10 minutes and a comonomer content of 2 to 8% by weight.

If the density is below the above range, the blocking of the film or the like when made into a composition will be greatly reduced and the effect of the present invention will be low, and if the density is above the range, there will be disadvantages such as poor transparency and impact strength. have

In addition, those whose melt flow rate is below the above range,
The processability is poor, and those that are better have the disadvantage that the processability and the impact strength of the film etc. are reduced.

Furthermore, comonomer contents outside the above ranges have disadvantages such as undesirable clarity, impact strength, and rigidity of the final target composition.

More preferably, those having a flow ratio of 6 to 15 are desirable in terms of extrusion processability and transparency.

Such copolymers include ethylene and one or more copolymers such as propylene, butene-11hexene-1,4-methylpentene-1, octene-1, etc., in a pressure cuff of approximately 0 kg/cm''. It is obtained by polymerizing the following,
As a manufacturing method, for example, the method described in Japanese Patent Publication No. 56-18132 is known.

The component (b) used in the present invention includes, for example, silicon dioxide, zeolite, and talc. These can be used together. Silicon dioxide preferably has an average particle size of 1 μm or less, particularly 5 μm or less from the viewpoint of transparency. This includes natural silica and synthetic silica, and commercially available products such as "Thyroid 66" and "Thyroid 244j (product name manufactured by Fuji Davison) are particularly preferred. Zeolite and talc have an average particle size of 20μ or less, especially 5μ. The following are preferable in terms of film appearance.The zeolite may be either natural or synthetic.

For example, C3100 (product name manufactured by Nihon Kagaku Kogyo Co., Ltd.) and U4
7 (product name manufactured by Mizusawa Chemical Co., Ltd.).

Furthermore, the component (c) used in the present invention is an organic amide compound consisting of a combination of an unsaturated fatty acid amide and a saturated fatty acid amide. Preferred examples of unsaturated fatty acid amides include erucic acid amide and oleic acid amide, and preferred examples of saturated fatty acid amides include behenic acid amide and stearic acid amide. A combination of these two components in a range of 3:7 to 7:3 is particularly effective in improving the balance of physical properties, and provides a particularly satisfactory balance of blocking properties, slip properties, transparency, and printability. is a 3:1 ratio of saturated fatty acid amide to unsaturated fatty acid amide.
Particularly desirable are compositions that are mixed in close proximity.

The blending ratio of these components (al to (c)) is 0.01 to 1 part by weight, preferably 081 to 0.6 part by weight, of component (b) to 100 parts by weight of component (a), and (c
) component is 0.01-1! Amount part, preferably 0. ．． 05～
It is 0.3 parts by weight.

In addition, (as a BL component, silicon dioxide with an average particle size of 1 μm or less and zeolite or talc with an average particle size of 20 μm or less in a weight ratio of 1/9 to 9/1, preferably 515 to 1/9)
When used together, there is no whitishness and it is preferable in terms of blocking.

If the amount of component fb) is less than the above range, the blocking property when formed into a film will deteriorate, which is undesirable, and if it exceeds the above range, the transparency when formed into a film will be significantly reduced.

If component (c) is below the above range, the slip properties and blocking properties will be significantly reduced, and if it is above the range, not only will there be too much slip, but the printability and heat sealability will also be significantly deteriorated, which is undesirable.

In order to achieve a particularly satisfactory balance of transparency, blocking properties, and slip properties, preferably, in the process of producing these compositions, granules with a size of 200 μm or less are used as component (a), and first ( al component and (b) component l
It is desirable to use a composition produced in the following order: thoroughly mixing Component I with ash in a blender such as a Henschel mixer, further adding Component I to this mixture, and pelletizing the mixture with an extruder.

In the present invention, commonly used additives such as antioxidants, stabilizers, antifogging agents, antistatic agents, UV agents, and nucleating agents may be added.

Component (a) includes not only the above copolymer, but also a blend of the above copolymer with other resins such as high-pressure low density polyethylene, high density polyethylene, polypropylene, polybutene, and ethylene-vinyl acetate copolymer. can also be applied.

〔Effect of the invention〕

Films and the like using the composition obtained in the present invention have excellent transparency and a very good balance of blocking properties, slip properties, and printability.

〔Example〕

Of the ingredients listed in Table 1 below, components (a) and (bl) were mixed in a Henschel mixer, and component (c) was further added thereto and mixed. A composition was prepared by pelletizing at a temperature of 230° C. using an extruder with L/D 28.

This composition was processed into films using the following three methods.

(i) Film processing method (11) The composition was processed using a linear air-cooled inflation extruder for ethylene polymer (40n diameter,
Screw L/D 18) and spiral type diamond 5f
Extrude to a film thickness of 30 μm at 200° C. using a diameter of 1 (lip width: 3×). At this time, the blow ratio was adjusted to 2.0.

(ii) Film processing method (2) The composition is processed using double air slit nearing in the same manner as the air cooling inflation described above.

(iii) Film processing method (3) The composition was processed using an air-cooled inflation extruder (40 mm diameter, screw L/D2) using a single air slit air ring.
2) and spiral die 100 ms diameter (lip width 0
．． 81111), the film thickness was 30 at 180℃.
Extrude to μ. At this time, the blow ratio was adjusted to 1.5.

The quality of the film thus obtained was evaluated on the following items. The measurement method is as follows.

The evaluation results are shown in Table 2.

The melt flow rate (MFR) is based on ASTM D1.
238 (190°C), and the flow ratio was determined according to JIS K7210-1975 using a melt indexer at 190°C based on the following formula.

The average particle diameters of silica, zeolite and talc are values determined by the Coulter Counter method (dispersion method is 28KC ultrasonic wave for 5 minutes, using 0.01% sodium hexametaline phosphate).

Synthetic silica is Thyroid 66, and zeolite is C8100.
was used.

(1) Haze Measured in accordance with ASTM D1003-61.

(2) Light scattering index (LSI) After conditioning the formed film at 23°C ± 2°C and 50 ± 5% RH for more than 24 hours, the LSI meter EvanceElectr
(manufactured by Oselenium) to measure the light scattering index.

(3) Blocking molded film at high temperature (45℃) and high load (50g/cm)
After promoting film adhesion for 24 hours at
It is expressed as the maximum stress (g/10 cm") required to shearly peel off 10 cm2 of the film adhesive surface under the following conditions.

(4) Static friction coefficient Measured in accordance with ASTM D1894.

(5) Wetting tension Measured in accordance with ASTM D2578-67.

(Margin below)

Claims (1)

[Claims] Contains each of the following components (a) to (c), 100% of component (a)
A resin composition for extrusion molding, characterized in that component (b) is blended in a proportion of 0.01 to 1 part by weight and component (c) is blended in a proportion of 0.01 to 1 part by weight based on parts by weight. (a) Density 0.9 produced using Ziegler catalyst
10~0.940g/cm^3, melt flow rate 0
．． Ethylene copolymer with 01 to 20 g/10 min and comonomer content of 1 to 10% by weight (b) Anti-blocking agent (c) Organic amide compound consisting of a combination of unsaturated fatty acid amide and saturated fatty acid amide