JPS6241529B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a resin composition for extrusion molding. More specifically, the present invention relates to an extrusion molding resin composition suitably used for extrusion molding of packaging films and the like. Currently, there is a wide variety of flexible packaging materials used for packaging foods, pharmaceuticals, miscellaneous goods, industrial supplies, etc., but most of them are made of low-density polyethylene, polypropylene, and ethylene-vinyl acetate copolymer made by radical polymerization. Coalescence, ethylene-
A polyolefin resin such as an ionically crosslinked acrylic acid copolymer (ionomer resin) is used as its heat seal layer. These packaging materials often take the form of, for example, a single film of the above-mentioned polyolefin resin or a laminated film of these films and another suitable base film. In the case of laminated films, bonding with adhesives, coextrusion, extrusion coating, dry lamination, etc. are applied during their production. By the way, packaging materials are originally designed to have tensile strength, tear strength, impact strength,
Mechanical strength such as heat seal strength, barrier function such as moisture proofing and gas barrier properties,
Many functions are required, including thermal properties such as heat resistance and cold resistance, as well as packaging machine adaptability such as heat sealability, hot tack, rigidity, and slip resistance. Whether or not a single polyolefin resin film can satisfy these requirements varies greatly depending on the type of resin used. Furthermore, even in the case of laminated films, the functionality of the packaging material changes significantly depending on the selection of the base material. For example, the following facts are shown regarding the characteristics of packaging materials manufactured by dry laminating various polyolefin films on stretched polyamide (nylon) films. In other words, when a high-pressure low-density polyethylene film is used as the heat-sealing layer, this laminated film can be heat-sealed at temperatures above about 110°C, and is superior in terms of heat-sealing strength, impact bag-breaking strength, and rigidity. Provides a reasonably balanced packaging material. However, in automatic filling packaging, when the contents are filled immediately after being heat-sealed and the weight is applied to the sealed part that has not yet been sufficiently cooled and solidified, the hot tack, which indicates the sealing performance, is low. Density polyethylene film is not very good. In addition, when polypropylene is used for the heat-sealing layer, the heat-sealing start temperature is approximately 30 to 40°C higher than that of low-density polyethylene, which is disadvantageous for high-speed filling, and the heat of the base material and printing ink increases. It has potential problems such as causing deterioration. Furthermore, although it is superior to low-density polyethylene in terms of rigidity and hot-tack, it has low impact tear strength and is not necessarily suitable for packaging liquids. When an ethylene-vinyl acetate copolymer is used in the heat-sealing layer, the heat-sealing temperature is more than 10°C lower than when low-density polyethylene is used.
Although it has high heat seal strength and impact bag tear strength, it has low rigidity and softness, and is inferior in hot tack. In addition, when an ionically crosslinked ethylene-acrylic acid copolymer (ionomer resin) is used for the heat seal layer, it has improved low-temperature heat sealability, heat seal strength, and hot tack compared to when low density polyethylene is used. Although it is extremely superior and also has excellent impact tear strength, it is not as good as ethylene-vinyl acetate copolymer. As described above, even if we compare the properties of various polyolefin resins that are currently generally used for the heat seal layer of laminated packaging materials, they all have advantages and disadvantages, and are not necessarily satisfactory. The present invention aims to provide a resin composition for extrusion molding that eliminates all the drawbacks of polyolefin resins used as heat sealing layers of such packaging materials, and this resin composition is suitably used for extrusion molding. For example, it may be extrusion coated onto a base film to form a heat seal layer thereon, or it may be extrusion molded into a single film or a composite film. Therefore, the present invention relates to a resin composition suitably used for extrusion molding, etc., and this resin composition has (a) a density of 0.91 to 0.94 obtained by high-pressure radical polymerization;
about 10-70% by weight of low-density polyethylene in g/ ^cm3 , (b)
Approximately 20 to 80% by weight of ethylene-α-olefin (3 to 8 carbon atoms) copolymer with a density of 0.91 to 0.95 g/cm ³ and (c) low crystallinity to amorphous with a density of 0.85 to 0.90 g/cm ³ It is made by uniformly melting and mixing approximately 10 to 50% by weight of an ethylene-α-olefin (3 to 4 carbon atoms) copolymer, and has a melt index (190°C) of 1 to 15 g/
Melt tension at 190℃ in 10 minutes is 1.0-7.0g
has a range of values. Such resin compositions have excellent properties such as low-temperature heat-sealability, heat-seal strength, hot-tack, and bag-breaking strength.
It can fully satisfy the performance required for the heat-sealing layer of packaging materials, and has excellent extrusion processability. The low-density polyethylene used as component (a) of the resin composition according to the present invention is generally produced under a reaction pressure of about 1000 to Polyethylene with a density of 0.91 to 0.94 g/cm ³ is obtained by radical polymerization under high pressure of 3000 atmospheres, and one of its characteristics is that when intermolecular chain transfer and double bonds in the main chain are involved in polymerization. One example is that the melt tension during melting is large due to the long chain branching that occurs. On the other hand, polyethylene obtained by polymerizing under medium to low pressure of about 1 to 100 atmospheres using metal oxide catalysts or Ziegler catalysts has virtually no long chain branches, so its melt tension is low. Very small.
In addition, ethylene-α-olefin copolymers, which are copolymerized by introducing various α-olefins as comonomers into this polymerization process, also do not have long chain branches.
Therefore, its melt tension is small. This melt tension influences the extrusion molding processability of the resin, and if it is too small, the self-supporting properties of the molten film during film molding or extrusion coating molding will be low, causing film sway. On the other hand, if it is too large, there will be a problem in the spreadability of the molten film, and the film will easily break during high-speed molding. The melt index of the low density polyethylene used in the present invention is approximately 0.5 to 30.
Preferably, it is in the range of g/10 minutes. If the melt index is lower than this, the melt viscosity will be too high and film breakage will occur easily, while if it is higher than this, the bag breakage strength and heat sealing strength will decrease, and at the same time there will be problems with film formation stability during molding. occurs. The ethylene-α-olefin copolymer of component (b) is a combination of ethylene and α-olefin having 3 to 8 carbon atoms, such as propylene, butene-1, pentene-
It is a copolymer with 1, hexene-1, octene-1, 3-methylbutene-1, 3,3-dimethylbutene-1, 4-methylpentene-1, etc., and 0.91
It has a density of ~0.95 g/ ^cm3 . Such copolymers are represented by chromium oxide, molybdenum oxide, titanium trichloride or titanium tetrachloride-alkylaluminum, titanium compounds such as titanium tetrachloride-magnesium compounds such as magnesium chloride-alkylaluminum (chloride), etc. It is produced by gas phase polymerization, slurry polymerization, solution polymerization, etc. under medium to low pressure of about 1 to 100 kg/cm ² using various catalysts. And these copolymers are about 0.2 to 8
Alpha-olefin content in mol% and approx. 0.5-30
Preferably it has a melt index of g/10 minutes. The low crystalline or non-crystalline ethylene-α-olefin copolymer of component (c) is a copolymer of ethylene and α-olefin having 3 to 4 carbon atoms, such as propylene and 1-butene. , 0.85~0.90
It has a density of g/cm ³ . Such a copolymer is obtained by polymerizing using a composite catalyst of a vanadium compound represented by vanadium trichloride or vanadium tetrachloride and an organoaluminum compound, and preferably contains about 5 to 30 α-olefins. mole%
They are copolymerized at a ratio of These copolymers desirably have a melt index within the range of about 0.5 to 30 g/10 minutes. These have low crystallinity (crystallinity by specific volume method is approx.
By using a non-crystalline ethylene-α-olefin copolymer (35% or less), the softening point of the resin composition is lowered, low-temperature heat-sealability and heat-sealing strength are improved, and impact resistance is also improved. Therefore, the bag breakage strength is improved. The resin composition of the present invention consists of (a) low density polyethylene, (b) ethylene-α-olefin (carbon number 3
~8) Copolymer and (c) low-crystalline to non-crystalline ethylene-α-olefin (3-4 carbon atoms) copolymer each contain about 10-70% by weight of component (a) and (b) The components are used in a mixture of about 20 to 80% by weight and component (c) about 10 to 50% by weight. If the mixing ratio of component (a) is less than about 10%, the melt tension of the resin composition will be too low, and the molten film during extrusion will become unstable, causing fluctuations in film width and film thickness. If it is more than about 70%, the heat sealing strength, hot tack, and bag tearing strength targeted by the present invention cannot be obtained, so neither is preferable. Regarding the mixing ratio of component (b), if it is less than about 20%, the heat sealing strength, hot tack, and bag tearing strength that are the objectives of the present invention cannot be obtained, and if it is more than about 80%, the resin pressure during extrusion molding is becomes high, making it impossible to obtain a high discharge rate, and at the same time, the melt tension of the molten film extruded from the die is too small, making the molten film unstable, and continuous stable productivity becomes difficult. Furthermore, if the mixing ratio of component (c) is less than about 10%, the desired low-temperature heat-sealing properties, heat-sealing strength, and bag-breaking strength of the present invention cannot be obtained;
If the amount exceeds %, the pellets after kneading will tend to block, and furthermore, products after film processing or extrusion coating may also have blocking problems. A resin composition consisting of components (a), (b) and (c) in such a mixing ratio also has a melt index of 1 to 15 g/10 minutes (190°C) and a melt tension of 1.0 to 1.0 at 190°C. Must be in the 7.0g range. If the melt index is less than 1, the resin pressure during extrusion molding of the resin composition increases, not only does the motor load become excessive, but also the molten film coming out of the die is likely to break. On the other hand, if it is larger than 15, not only the heat sealing strength and the bag tearing strength will decrease, but also problems will arise in the stability of the molten film during molding. In addition, if the melt tension at 190°C is less than 1.0 g, the self-supporting properties of the molten film will be small and there will be problems with the stability of the film, and if it is more than 7.0 g, problems will occur with the spreadability of the molten film and the film will break. It becomes easier to do. In this way, the above (a) and (b) of the specified mixing ratio
and (c) only a resin composition consisting of each component and having specified melting properties has excellent extrusion processing properties and at the same time fully satisfies the various properties required for a heat seal layer. . Regarding heat-sealing properties, the heat-sealing layer formed from this resin composition has low-temperature heat-sealing properties equivalent to that of ethylene-vinyl acetate copolymer, and the heat-sealing strength is comparable to that of this copolymer and ionomer resin. It exhibits a number of excellent properties, such as having a hot tack comparable to that of ionomer resins, and superior bag breakage strength to ethylene-vinyl acetate copolymer. A slip agent, an antiblocking agent, an antistatic agent, etc. can also be added to this resin composition as required. Slip agents that can be used include, for example, higher fatty acids having 8 to 22 carbon atoms, metal salts thereof such as aluminum salts, calcium salts, and magnesium salts, or acid amides, stearic acid esters of saturated aliphatic alcohols, ethylene bis fatty acids (with 16 carbon atoms), ~18) Examples include amide. Examples of antiblocking agents include silica, calcium carbonate, and talc. Furthermore,
Examples of antistatic agents include glycerin esters of fatty acids having 8 to 22 carbon atoms, sorbitan esters,
Examples include sucrose ester and polyethylene glycol ester. The components (a) to (c) and components optionally added as necessary can be mixed simultaneously or sequentially using a single screw extruder, twin screw extruder, Banbury mixer, various kneaders, etc. will be carried out. The mixed resin composition can be made into a film by extrusion molding such as inflation film molding or T-die casting, or it can be made into a film by extrusion molding such as inflation film molding or T-die casting, or it can be made into a film using polyethylene, polypropylene, ethylene-vinyl acetate copolymer,
A multilayer coextruded film can also be obtained by coextrusion molding with other suitable resins such as ionically crosslinked ethylene-acrylic acid copolymer (ionomer resin), polyamide, polyester, and polystyrene. Furthermore, the single film or coextruded film formed in this way can be used as a single or composite film or sheet of various plastics such as stretched or unstretched polypropylene film or sheet, polyamide film or sheet, stretched polyester film, aluminum foil, It is also possible to form a laminated film or sheet by dry lamination or sandwich lamination with cellophane, paper, etc., and the layer made of the resin composition of the present invention effectively acts as a heat-sealing layer. The resin composition according to the present invention can be extrusion-molded into a single film or various composite films or sheets as described above, but preferably it is extrusion-coated onto various substrates and a heat-sealing layer is applied thereto. It is desirable to form it. The extrusion coating can be used not only alone, but also as a coextrusion coating as in the case of forming the coextrusion film. Substrates to be extrusion coated include paperboard, paper, aluminum foil, and various plastic films and sheets used in lamination molding of the laminated films and sheets described above, and are applied according to general extrusion coating methods. be done. When the extruded product formed from the resin composition of the present invention is a single film, it is mainly used as packaging bags for food, feed, medicine, industrial goods, miscellaneous goods, etc. Various laminated films or sheets in which layers of this resin composition are formed by a lamination method or an extrusion coating method can be used as a heat-sealing layer to make sweets, snacks, furikake, powdered soups, etc. Its low-temperature heat is ideal for packaging various foods such as dried foods, meat products such as ham, sausage, and livestock meat, aquatic foods such as konnyaku, pickles, miso, and liquid soup, as well as liquid detergents and liquid medicines. It can be used effectively by taking advantage of its properties such as sealability, heat seal strength, hot tack, bag tear strength, and suitability for automatic filling and packaging. Next, the present invention will be explained with reference to examples. Example 1 Density obtained by high-pressure radical polymerization method
0.917g/ ^cm3 low density polyethylene (melt index 7g/10 min) 30% by weight, density 0.920g/cm3
cm ³ of ethylene-4-methylpentene-1 copolymer (4-methylpentene-1 content 3.0 mol%, melt index 2 g/10 min) 50% by weight and density
A 20% by weight mixture of 0.880 g/ ^cm3 of low crystalline ethylene-butene-1 copolymer (butene-1 content 10 mol%, melt index 4 g/10 min) was processed at 140°C in a single screw extruder. The mixture was melted and kneaded to form pellets.
The melt index of this uniformly mixed resin composition was 2.4 g/10 minutes, and the melt tension at 190°C was 3.5 g. The resin composition pellets were melt-kneaded using an extruder with a diameter of 6.5 mm at a cylinder tip temperature of 295°C, and then extruded through a T-die to form stretched nylon that had been prepared in advance using an isocyanate-based anchor coating agent. Extrusion coating of low density polyethylene (20μ thick) onto film (15μ thick) Processing speed 40 for polyethylene side of laminated film
The extrusion coating process was carried out under the conditions of m/min and coating thickness of 40 μm. At this time, the resin temperature directly under the die was 285° C., and the net-in indicating the difference between the opening width of the die and the width of the resin film of the laminate (a smaller value is preferable) was 46 mm on both sides. The heat seal strength, hot tack, bag tear strength and impact bag tear strength of the obtained three-layer laminate were measured by the methods described below, and the results are shown in Table 1 below, all of which were good. Characteristic values have been obtained. [Measurement method] Melt tension: Using a Toyo Seiki melt tension tester, the winding roll was sped up at 5 rpm intervals under the conditions of a measurement temperature of 190°C and an extrusion rate of 0.3 g/min, and the melt strand was The melt tension when cut was determined. Heat sealing strength: heat sealing pressure 2Kg/cm ² ,
Heat sealing time 0.5 seconds, tensile speed 300mm/
Measured at a peel angle of 90°C. Hot-tack: A 45g weight is separately attached to the same end of two laminate samples via a guide roll, and after the samples are heat-sealed, as soon as the sealing bar is separated, the sealing part is placed at a 23° angle. A peeling force is applied by the weight (this angle is set depending on the positional relationship of the guide rolls on which the weight is applied), and the number of millimeters of peeling of the seal portion is measured at this time. Bag breakage strength: 100 bags made by heat sealing under the conditions of pressure 2Kg/cm ² , temperature 140℃, and time 0.5 seconds.
A ×160 mm bag was filled with 200 ml of tap water and pressurized using an automatic press at a pressing speed of 10 mm/min. Impact bag breaking strength: The sample bag used to measure the bag breaking strength was left still, a flat weight with a load of 7 kg was dropped onto it, and the height of the load at the point at which the sample bag broke was measured. Net-in: The value obtained by subtracting the width of the resin film of the extrusion coating product from the opening width of the die was taken as the double-sided net-in value. Examples 2 to 4 In Example 1, the composition of the resin composition was variously changed, and various characteristic values were similarly measured for the resulting three-layer laminate. As shown in Table 1 below, good results were obtained in all cases. Comparative Example 1 In Example 1, extrusion coating of only low density polyethylene was performed. As shown in the results in Table 1 below, compared to the extrusion coating laminate of the resin composition according to the present invention, the heat seal strength is lower, the low temperature heat sealability and hot tack are inferior, and the bag tear strength is also lower. It lacks suitability as a packaging material. Comparative Example 2 In Example 1, ethylene-4-methylpentene-1 copolymer (melt tension at 190°C 0.85
Extrusion coating of only g) was performed, but T-
Both ends of the molten film extruded from the die were not stable, making it impossible to obtain an extruded coating film with a constant width and thickness. Comparative Example 3 In Example 1, low crystalline ethylene-butene-1 copolymer (melt tension at 190°C 0.46 g)
However, both ends of the molten film extruded from the T-die were not stable, making it impossible to obtain an extruded coating film with a constant width and thickness. Comparative Example 4 In Example 1, 20% by weight of low density polyethylene and ethylene-4-methylpentene-1 copolymer
Extrusion coating of the resin composition with 80% by weight was carried out. As shown in the results in Table 1 below, compared to the extrusion coating laminate of the resin composition according to the present invention, although the hot tack is the same, the heat seal strength and low temperature sealability are inferior, and the bag tear strength is also poor. Because it is small, it is not suitable as a packaging material. Comparative Example 5 In Example 1, a resin containing 70% by weight of low-density polyethylene, 10% by weight of ethylene-4-methylpentene-1 copolymer, and 20% by weight of low-crystalline ethylene-butene-1 copolymer Extrusion coating of the composition was performed. As shown in the results in Table 1 below, compared to the extrusion coating laminate of the resin composition according to the present invention, it is inferior in heat seal strength, hot tack, and bag tear strength, so it is not suitable as a packaging material. There are some shortcomings. Comparative Example 6 Ethylene-vinyl acetate copolymer (EVA; vinyl acetate content 6% by weight, melt index 7
g/10 minutes), and extrusion coating was performed in the same manner as in Example 1 (however, the cylinder tip temperature was 245°C). As shown in the results in Table 1 below, compared to the extrusion coated laminate of the resin composition according to the present invention, it can be said that the low-temperature sealing property and static pressure bag breaking strength are the same, but the heat sealing strength, hot tack, Since both of these bags have poor impact tear strength, they lack suitability as packaging materials.

【table】

[Table] Example 5 In Example 1, low density polyethylene had a density of 0.916 g/cm ³ and a melt index of 23 g/10.
using 20% by weight of 20% by weight, mixed with 60% by weight of ethylene-4-methylpentene-1 copolymer and 20% by weight of low-crystalline ethylene-butyne-1 copolymer,
This includes oleic acid amide as a slip agent.
500ppm, silica as antiblocking agent
A further 2000 ppm was added, mixed well, and melt-kneaded at 140°C using a single-screw extruder to form pellets. The melt index of this resin composition was 2.8 g/10 minutes, and the melt tension at 190°C was 1.6 g. Extrusion coating using this resin composition was carried out in the same manner as in Example 1, and the heat seal strength and hot tack of the resulting three-layer laminate were measured, and the results are shown in Table 2 below. From this result, it is judged that this resin composition has sufficiently satisfactory performance as a heat seal layer resin for packaging materials. In addition, Netzukin was 73 mm on both sides.

[Table] Example 6 In Example 1, the density of the ethylene-4-methylpentene-1 copolymer was 0.918 g/cm ³ , 4-
Methylpentene-1 content 3.2 mol%, melt index 8g/10 min 30% by weight, low density polyethylene 50% by weight, low crystallinity ethylene.
The mixture was mixed with 20% by weight of butene-1 copolymer and melt-kneaded at 140°C in a single-screw extruder to form pellets.
The melt index of this resin composition is 4.6g/
At 10 minutes, the melt tension at 190°C was 2.9 g. Extrusion coating using this resin composition was carried out in the same manner as in Example 1, except that a stretched polyester film with a thickness of 12 μm was used as one layer of the laminated film instead of the stretched nylon film, and the resin temperature immediately below the die was The temperature was 283℃. The heat seal strength and hot duct of the resulting three-layer laminate were measured, and the results are shown in Table 3 below. From this result, it is judged that this resin composition has sufficiently satisfactory performance as a heat seal layer resin for packaging materials. In addition, the netuquin was 40 mm on both sides.

[Table] Example 7 In Example 6, 20% by weight of low density polyethylene, 60% by weight of ethylene-4-methylpentene-1 copolymer, and 60% by weight of ethylene-butene-1 copolymer were used.
The content was 20% by weight. The melt index of the resin composition is 5.4 g/10 minutes, and the melt tension at 190°C is 1.6.
It was hot at g. Extrusion coating using this resin composition was carried out in the same manner as in Example 6, and the heat seal strength and hot tack of the resulting three-layer laminate were measured, and the results are shown in Table 4 below. From this result, it is judged that this resin composition has sufficiently satisfactory performance as a heat seal layer resin for packaging materials. In addition, the netsuquin was 74 mm on both side walls.

[Table] Comparative Example 7 In Example 6, 10% by weight of low density polyethylene, 70% by weight of ethylene-4-methylpentene-1 copolymer, and 70% by weight of ethylene-butene-1 copolymer were used.
The content was 20% by weight. The melt index of the resin composition is 2.6 g/10 minutes, and the melt tension at 190°C is 0.61.
It was hot at g. Extrusion coating using this resin composition was carried out in the same manner as in Example 6, but both ends of the molten film extruded from the T-die were not stable and it was difficult to obtain an extruded coating film with a constant width and thickness. I couldn't do it. Example 8 The resin composition used in Example 1 was melt-kneaded at 175°C using an extruder with a diameter of 30 mm, and extruded through a circular die with a diameter of 50 mm to form an inflation film. I got a standalone film. The processing speed at this time was 8 m/min, the pull-up ratio was 2.7, and a single air ring was used to cool the film. Comparative Example 8 A blown film (thickness: 40 μm) of high-pressure low-density polyethylene (melt index: 3 g/10 minutes) having a density of 0.921 g/cm ³ was molded in the same manner as in Example 8. Various physical properties were measured for the single films obtained in Example 8 and Comparative Example 8, and the results are shown in Table 5 below. From the results in this table, it is clear that the film obtained from the resin composition according to the present invention is excellent in various physical properties such as tensile strength, elongation, tear strength, and falling ball impact strength.

[Table] Comparative Example 9 Using the resin composition used in Comparative Example 7, a blown film was molded in the same manner as in Example 8, but the transparent molten tube coming out of the die was exposed to cooling air. As a result, the whitening point, which indicates the whitening position, fluctuates erratically, and at the same time, the fold diameter of the film product also fluctuates, making it difficult to obtain a film with a constant width and thickness. Example 9 50% of the resin composition pellets prepared in Example 1
Melt-kneaded at 150℃ using a mm diameter extruder, while melt-kneading ethylene-vinyl acetate copolymer (vinyl acetate content 5% by weight, melt index 8g/10 minutes) at 150℃ using a 40mm diameter extruder. These two resin streams were then introduced into a 125 mm diameter two-layer coextrusion inflation die set at a temperature of 150°C and coextruded to form a resin composition layer of 20μ and an ethylene-vinyl acetate copolymer layer of 20μ. A coextruded blown film was formed. The machining speed at this time is 7m/
The blowup ratio was 2.0, and a single air ring was used to cool the film. The heat seal strength, tensile strength, elongation, tear strength and falling ball impact strength of the obtained coextruded blown film were measured, and the results are shown in Table 6 below. Comparative Example 10 In Example 9, high-pressure low density polyethylene (density 0.918 g/cm ³ , melt index 20 g/10 minutes) was used instead of the resin composition. Regarding the obtained coextruded blown film, various physical properties were measured in the same manner as in Example 9, and the results are shown in Table 6 below.

【table】

[Table] From the results shown in Table 6, it can be seen that the coextruded film containing the resin composition of the present invention as one layer has various physical properties such as low temperature heat sealability, heat seal strength, elongation, and falling ball impact strength. It is clear that it is superior in terms of Note that the heat sealability is measured between resin composition layers or between low density polyethylene layers.

Claims (1)

[Claims] 1 (a) Density obtained by high-pressure radical polymerization method
0.91-0.94g/ ^cm3 low density polyethylene about 10-70
Weight%, (b) Ethylene-α with density 0.91-0.95 g/ ^cm3
- Olefin (3 to 8 carbon atoms) copolymer approximately 20 to 80
and (c) about 10 to 50 weight % of a low-crystalline to non-crystalline ethylene-α-olefin (3 to 4 carbon atoms) copolymer with a density of 0.85 to 0.90 g/cm ³ are uniformly melt-mixed. The melt index is 1 to 15 g/10 minutes (190℃) and the melt tension at 190℃ is 1.0 to 15g/10 minutes (190℃).
A resin composition for extrusion molding having a value in the range of 7.0 g. 2. The resin composition for extrusion molding according to claim 1, which is used for extrusion coating molding. 3. The extrusion molding resin composition according to claim 2, which is used for forming a heat seal layer. 4. The resin composition for extrusion molding according to claim 1, which is used for extrusion molding of films or sheets.