JP3367348B2 - Linear low density polyethylene film - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear low-density polyethylene-based film, and more specifically, a linear low-density polyethylene-based film having suitable mechanical strength, low-temperature thermal adhesion and excellent blocking resistance. Regarding film.

[0002]

2. Description of the Related Art In recent years, with the remarkable development of distribution systems and packaging systems, packaging of articles by automatic packaging machines is
Because of its excellent simplicity and productivity, it is widely used for packaging various products such as foods and beverages. At the same time, the speed and efficiency of these automatic wrapping machines are being further increased for the purpose of further improving productivity.
For example, when packaging a liquid (semi-fluid) food, as a method of simultaneously treating the sterilization step and the packaging step of the food, there is a hot filling method in which the food is preheated to 60 to 100 ° C. and directly filled in a packaging bag. Used favorably.

On the other hand, a polyolefin film is widely used as a sealant material for an automatic packaging film. Among them, a non-stretched film made of linear low density polyethylene is excellent in low-temperature heat adhesion, hot tack and impact resistance. Therefore, it is useful as a packaging film for these. Further, with the recent growing need for high-speed automatic filling, technological improvement of the sealant material itself has been advanced, and many low-temperature heat-adhesive films in which a resin having a low melting point is laminated on a heat-sealing layer are put on the market. However, at present, despite improving the thermal adhesiveness at low temperatures, improvement in high-speed filling optimization by an automatic packaging machine in practice is not sufficient,
The current situation is that it does not meet the high demands of the market. In addition, if the thermal adhesiveness at a relatively low temperature is increased, it goes without saying that the thermal adhesiveness is increased, and when the liquid (semi-fluid) is filled at a high temperature, the sealant materials inside the package are Causes a problem of heat fusion. That is, the phenomenon that the hot filling property of the liquid is deteriorated occurs, and there is a risk of impairing the appearance of the packaged product.

These sealant materials are usually biaxially stretched nylon films which are inferior in low temperature heat adhesion to the sealant material,
Biaxially stretched ester film, it is generally used by laminating with a substrate made of a biaxially stretched plastic film such as a biaxially stretched polypropylene film, but since it blocks during lamination and bag making,
In order to improve it, there is known a method of avoiding blocking between sealant materials or between sealant material and base material by shaking powder such as starch. However, this not only contaminates the area around the film processing equipment, but also significantly deteriorates the appearance of the packaged food, or causes problems such as hygiene such that the powder adhering to the sealant material mixes directly with the food into the package. Although there is a long-awaited improvement, it is not yet in a satisfactory state.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a linear low-density polyethylene-based film having excellent blocking resistance while maintaining low-temperature heat-adhesiveness and mechanical suitability, especially when laminated with a biaxially stretched plastic film. An object of the present invention is to provide a linear low-density polyethylene-based film that can be used as a laminate that exhibits excellent properties such as high-speed bag-making property in an automatic packaging machine, bag-making airtightness, and liquid hot-filling property.

[0006]

In order to achieve the above object, the linear low density polyethylene film of the present invention has a density
0.860 to 0.925 g / cm ³ , weight average molecular weight /
Is it a linear low density polyethylene with a number average molecular weight of 1 to 3?
And a linear low-density poly that constitutes the sealing layer
From linear low density polyethylene, which is denser than ethylene
In a sealing layer
The average particle size is 3 to 15 μm and the average particle size is different 2
0.3 to 2.0% by weight of one or more inert particles.
The Young's modulus is 1000 to 2200 kg / cm ² , and the sealing start temperature is 95 ° C. or lower.

Here, the seal starting temperature is a temperature measured by the following method. That is, when the linear low-density polyethylene-based film was heat-sealed under the conditions of a pressure of 1 kg / cm ² and 1.0 second by a heat gradient heat sealer manufactured by Toyo Seiki Co., the strength was measured, and when the strength was 500 g / 15 mm. Temperature (° C).

The linear low-density polyethylene-based film having the above-mentioned structure is rigid, has appropriate mechanical strength, and is excellent in low-temperature thermal adhesion, slipperiness, and blocking resistance. It is a system film.

The linear low-density polyethylene-based film may be a film layer in which the substrate layer is formed of two or more multilayer linear low-density polyethylene films.

The linear low-density polyethylene film having the above-mentioned constitution can be variously combined in the type of linear low-density polyethylene used, the combination of various additives, and the like.

The linear low-density polyethylene film may have an average density of the linear low-density polyethylene constituting the multilayer body of 0.900 to 0.930.

The linear low density polyethylene film having the above structure has rigidity and excellent blocking resistance.

In the linear low-density polyethylene film, the thickness of the sealing layer can be 3 to 20% of the total thickness of the multilayer body.

The linear low-density polyethylene film having the above structure is well balanced in terms of film rigidity and bag-breakage resistance.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the linear low density polyethylene film of the present invention will be described below.

Although the linear low density polyethylene used in the present invention is a polymer of ethylene, it can be formed mainly by a random copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms. Examples of the α-olefin having 3 to 12 carbon atoms include propylene, butene-1, pentene-1, hexene-1, octene-1, 4-methylpentene-1, decene-1, dodecene-1. Among these, higher α having more carbon atoms than hexene-1
-A copolymer with an olefin is preferable because a film having excellent impact resistance can be obtained. The α-olefin that can be the comonomer unit of the random copolymer may be one type alone or two or more types.

The linear low density polyethylene film of the present invention has a Young's modulus of 1000 to 2200 kg / cm ² and a sealing start temperature of 95 ° C. or lower . Young's modulus is 110
0 to 2000 kg / cm ² is preferable, 1200 to 18
00 kg / cm ² is more preferable. Young's modulus is 1000
If it is less than kg / cm ² , mechanical suitability for an automatic bag filling machine is poor, and blocking resistance and hot filling suitability are deteriorated, which is not preferable. On the other hand, when it exceeds 2200 kg / cm ² , airtightness during bag making is deteriorated and suitability for high speed bag making is remarkably impaired. The sealing start temperature is preferably in the range of 50 to 95 ° C. If the temperature is 95 ° C. or higher, the heat-sealing property at the time of high-speed bag making is deteriorated and the suitability for high-speed bag making is remarkably deteriorated, which is not preferable. Further, at a sealing start temperature of 50 ° C. or lower, blocking resistance tends to decrease, which is not preferable.

The linear low-density polyethylene-based film of the present invention comprises a linear low-density polyethylene sealing layer having a density of 0.860 to 0.925 g / cm ³ and a weight average molecular weight / number average molecular weight of 1 to 3. And a base layer made of linear low-density polyethylene having a higher density than the linear low-density polyethylene forming the seal layer .

The linear low density polyethylene film of the present invention comprises a base layer (base layer or base layer and laminate layer).
Is a linear low-density polyethylene having a higher density than that of the seal layer . When the density of the base layer is lower than the density of the seal layer, the rigidity of the entire film is lowered and the mechanical suitability and blocking resistance are deteriorated, which is not preferable. In the present invention, the preferred layer structure is a two-layer structure comprising a base layer as a seal layer and a base layer, or a three-layer structure comprising a base layer / laminate layer as a seal layer and a base layer. In the above configuration, the linear low density polyethylene used for the seal layer has a density of 0.880 to 0.915 g.
/ Cm ³ is preferable, 0.890 to 0.905 g / cm
³ is more preferable. When the density is less than 0.860 g / cm ³ , the blocking resistance tends to deteriorate, which is not preferable. On the other hand, when it exceeds 0.925 g / cm ³ , the low temperature thermal adhesiveness tends to deteriorate, which is not preferable.

The weight average molecular weight / number average molecular weight of linear low density polyethylene is a measure of the molecular weight distribution, ideally being 1 which is a monodisperse molecular weight distribution, but the weight average molecular weight / number average molecular weight is 3 Can be tolerated. The weight average molecular weight / number average molecular weight is preferably 2.5 or less, 2.
It is more preferably 3 or less. When the weight average molecular weight / number average molecular weight exceeds 3, the adhesiveness of the linear low density polyethylene increases, the handling property of the linear low density polyethylene deteriorates, and the blocking resistance of the film deteriorates. It is not preferable because it occurs.

The linear low density polyethylene used for the base layer preferably has a density in the range of 0.900 to 0.935 g / cm ³ , and the linear low density polyethylene used for the laminate layer has a density of 0.915 to 0. A range of 950 g / cm ³ is preferred. In the present invention, a more preferable range of the linear low-density polyethylene density constituting each layer is seal layer <base layer or seal layer <base layer <laminate layer.

As the linear low-density polyethylene used for the seal layer and the base layer, one having characteristics in the above range may be used alone, or the weighted average value of the density may be within the above range.
One or more species may be mixed and used, but it is particularly preferable to use one species.

The method for producing the linear low-density polyethylene used in the present invention is not particularly limited, but the linear low-density polyethylene used for the seal layer is produced by using a single site catalyst such as a metallocene catalyst for the content. It is more preferable in terms of odor of the film and blocking resistance. Further, the base layer and the laminate layer may be manufactured using a single site catalyst,
It may be produced using a multi-site catalyst such as a Ziegler catalyst, but the latter method is more preferable in terms of cost.

The linear low-density polyethylene film is usually a multi-layered body having two layers consisting of a seal layer and a base layer (base layer) or three layers consisting of a seal layer and a base layer (base layer and laminate layer). Although it is general, a multilayer having more layers, for example, 4 to 5 layers may be used. In the linear low-density polyethylene film, the resin forming each layer is properly used according to the purpose from its general concept. For example, it can be laminated on a base layer such as a seal layer for the purpose of thermal adhesiveness, a base layer that controls physical properties of the entire film, a biaxially stretched nylon film, a biaxially stretched polyester film, a biaxially stretched polypropylene film, etc. Examples thereof include a laminate layer that can be used and an adhesive layer that bonds the layers.

In the linear low-density polyethylene film of the present invention, the average density of the linear low-density polyethylene constituting the multilayer body is preferably 0.900 to 0.930. More preferably, the average density is 0.905 to 0.
The range is 925. If the average density is less than 0.900,
It is not preferable because the rigidity of the entire film is reduced and sufficient mechanical suitability and blocking resistance cannot be obtained. On the other hand, if the average density exceeds 0.930, the airtightness of the bag is deteriorated, which is not preferable. The average density of the linear low density polyethylene forming the multilayer body is the sum of the multiplication of the density of the resin forming each layer and the layer ratio.

The linear low density polyethylene used for the above-mentioned seal layer and base layer has a melt index of 0.1.
It is preferable to use one having a range of ˜5 g / 10 minutes (190 ° C.), more preferably 0.5 to 4 g / 10 minutes (190 ° C.). If the melt index is less than 0.1 g / 10 min, the thermal adhesive strength is saturated, the melt viscosity is high, and the load on the motor of the extruder tends to be large, which is not preferable. On the other hand, if it exceeds 5 g / 10 minutes, the thermal adhesive strength tends to decrease, which is not preferable.

The thickness of the seal layer of the linear low density polyethylene film of the present invention is preferably 3 to 20% of the total weight of the multilayer body. More preferably, it is 5 to 15%.
If the thickness of the seal layer is less than 3%, the thermal adhesive strength will decrease,
This is not preferable because the bag-making product has poor bag-breaking resistance. On the other hand, if the thickness of the seal layer exceeds 20%, the rigidity of the entire film decreases, and sufficient mechanical suitability and blocking resistance cannot be obtained, which is not preferable.

In the present invention, the sealing layer has an average thickness.
Two or more kinds of particles having a particle size of 3 to 15 μm and different average particle sizes
Inert particles 0.3 to 2.0 wt% free Murrell. If the average particle size is less than 3 μm, slipperiness and blocking resistance deteriorate .
It Conversely, the appearance is deteriorated when it exceeds 15 [mu] m. The diameter of the inert particles is more preferably 5 to 12 μm.

If the content of the inert fine particles is less than 0.3% by weight, the slipperiness and the blocking resistance are deteriorated, which is not preferable. On the contrary, if it exceeds 2.0% by weight, the appearance is deteriorated, which is not preferable. 0.5 to 1.5% by weight is more preferable.

The inert fine particles have different average particle diameters.
It is a preferable mode to use two or more kinds in combination.

The above-mentioned inert fine particles may be organic fine particles or inorganic fine particles.

The inorganic fine particles are not particularly limited as long as they are insoluble and inactive in linear low density polyethylene. Specifically, silica, alumina, zirconia,
Metal oxides such as titania; kaolinite, zeolite,
Examples thereof include complex oxides such as sericite and sepiolite; sulfates such as calcium sulfate and barium sulfate; phosphates such as calcium phosphate and zirconium phosphate; and carbonates such as calcium carbonate.

These inorganic fine particles may be natural products or synthetic products, and the shape of the particles is not particularly limited.

The molecular structure of the organic fine particles used in the present invention is not particularly limited as long as it has heat resistance to withstand the melt molding temperature of the above linear low density polyethylene, and is obtained by an addition polymerization method. It may be one obtained by a polycondensation or polyaddition reaction method. The polymer constituting the fine particles may be a non-crosslinked type or a crosslinked type, but the crosslinked type is recommended from the viewpoint of heat resistance. Preferably, the organic fine particles are not melted at the melt molding temperature.

The method of micronizing the polymer is also not limited, but a method of directly micronizing during polymerization using a method such as emulsion polymerization or suspension polymerization is preferable. When these polymerization methods are adopted, a means for copolymerizing a small amount of a polar monomer having a special structure capable of imparting self-emulsifying property may be adopted.

The material for the crosslinked polymer particles is, for example,
Acrylic acid, methacrylic acid, acrylic acid esters, acrylic monomers such as methacrylic acid esters, styrene monomers such as styrene and alkyl-substituted styrene, and the like, divinylbenzene, divinylsulfone, ethylene glycol dimethacrylate, Copolymers with crosslinkable monomers such as trimethylolpropane trimethyl acrylate and pentaerythritol tetramethyl acrylate; melamine resins; benzoguanamine resins; phenolic resins;
Silicone resins and the like can be mentioned.

Among the above materials, it is particularly preferable to use a copolymer of an acrylic monomer and / or a styrene monomer and a crosslinkable monomer.

The shape of the inert particles is not particularly limited, but a substantially spherical or rugby ball shape is preferable.

As the above-mentioned inert particles, inorganic or organic particles may be used alone, but a method of using inorganic and organic fine particles having different average particle diameters in combination balances appearance, slipperiness and blocking resistance. This is a particularly recommended aspect.

The linear low density polyethylene film of the present invention can be obtained by molding by a coextrusion molding method. Film formation can be performed according to a usual method for forming a film. For example, an inflation molding method using a circular die, a T die molding method using a T die, or the like is adopted. When performing T-die molding, the draft ratio between the die cooling rolls is about 1 to 10 times, and the resin temperature is about 190 to 3
It is preferable to select from the range of 00 ° C.

The thickness of the linear low density polyethylene film of the present invention is not particularly limited, but is preferably about 10 to 150 μm, more preferably about 20 to 100 μm.

The linear low-density polyethylene-based film of the present invention comprises a heat stabilizer, an antioxidant, an antistatic agent, an antifogging agent, a neutralizing agent, if necessary, in an amount which does not impair the object of the present invention. Lubricants, nucleating agents, colorants, other additives, inorganic fillers and the like can be added to necessary layers.

The linear low density polyethylene film of the present invention can be used as a laminated film with other plastic films.

Other plastic films to be laminated are not particularly limited, but biaxially stretched plastic films are preferable, and the breaking strength / elongation, Young's modulus,
From the viewpoint of impact strength, heat seal strength, etc., biaxially stretched nylon film, biaxially stretched polyester film,
And a biaxially oriented polypropylene film are more preferable.

The thickness of the biaxially stretched film for laminating depends on the purpose, but is usually 5 to 30 μm, preferably 10 to 25 μm for an automatic packaging machine.

The lamination method may be carried out by a method known per se, and examples thereof include dry lamination and extrusion lamination.

The linear low density polyethylene film of the present invention preferably has a hot filling temperature of 90 ° C. or higher. If the hot filling temperature is less than 90 ° C, the sealant materials inside the package may cause heat fusion when filling the heated contents, which may cause deterioration of the appearance of the package. It is not preferable because it exists.

[0048]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the following examples do not limit the present invention, and appropriate modifications are included in the technical scope of the present invention. The measuring method is as follows.

(1) Haze value The haze tester J manufactured by Toyo Seiki Co., Ltd. was used in accordance with JIS-K6714.

(2) Blocking resistance According to ASTM-D1893-67, the sealing layer surfaces of the film were measured together.

(3) Dynamic Friction Coefficient The sealing properties of the film are matched to each other according to JIS-
It measured according to K7215-1987.

(4) Sealing start temperature Pressure of 1 kg / by using a heat gradient heat sealer manufactured by Toyo Seiki Co., Ltd.
After heat-sealing under the condition of cm ² for 1.0 second, the strength is measured. In the case of the original film, the strength is 50.
The temperature when it becomes 0 g / 15 mm is 3 kg / 15 m in the case of a laminated product with a 15 μm biaxially stretched nylon film.
The temperature at which m was reached was the sealing start temperature. The sealing start temperature was measured by matching the surfaces of the sealing layers.

(5) Young's modulus (rigidity) It was measured according to ASTM-D882.

(6) Weight average molecular weight / number average molecular weight It was measured by gel permeation chromatography.

(7) Bag-making speed Using an automatic filling and packaging machine (Komatsu Seisakusho's half-fold three-way seal filling machine KS324), the contents were put in a packaging bag (size 50 mm x 70 mm) heat-sealed at a sealing temperature of 150 ° C. Hot filled with water at 80 ° C. Further, a load of 100 kg was applied to the filling and packaging bag for 1 minute, and a bag-making speed at which the bag could be made without breaking the seal or leaking water from the seal was determined. The bag-making speed was measured on a laminate with a biaxially stretched nylon film of 15 μm (laminate layer surface of linear low-density polyethylene-based film and laminate together with nylon film surface).

(8) Hot-filling temperature The laminated layer surface of the linear low-density polyethylene-based film and the surface of the biaxially stretched nylon film of 15μ are laminated together, and the resulting laminated body is sealed with the linear low-density polyethylene-based film. Using the automatic filling and packaging machine with the layer surface inside the bag, the bag was made into a size of 60 × 80 mm. At the time of bag making, 10 CC of warm water having a predetermined temperature is injected. Immediately after the hot water-filled bag is made, the hot water-filled portion of the hot water-filled bag is held at a pressure of 1 kg / cm ² per area of 1 cm × 1 cm and air-cooled. The hot water temperature was raised from 80 ° C. at a pitch of 2 ° C., and the temperature at which the inner surfaces of the film in the pressurizing portion were fused together was determined as the hot filling temperature.

(9) Roll blocking resistance The laminated layer surface of a linear low density polyethylene film and the surface of a biaxially stretched nylon film of 15μ are laminated together, and the resulting laminated body having a width of 130 mm has a tension of 15 kg /
m and a linear pressure of 1.0 kg / cm ² were wound into a roll and held in an atmosphere of 40 ° C. × 80% RH for 30 days, and then the blocking state of the roll-shaped film and the film were peeled off. The peeling noise at that time was distinguished by the following evaluation criteria.

[Evaluation Criteria] ⊚: No blocking with full width of roll, no peeling noise ○: No blocking with full width of roll, weak peeling noise Δ: Part of roll is blocking, strong Peeling noise x: Blocking at full width of roll, strong peeling noise

(10) Bag-making Air-tightness The laminated layer surface of the linear low-density polyethylene-based film and the surface of the biaxially stretched nylon film of 15μ are laminated together, and the obtained laminated body is half-folded into a size of 60 × 80 mm. Then, using a Toyo Seiki Co., Ltd. heat sealer, seal temperature is 18
After performing two-way heat sealing under the conditions of 0 ° C., pressure of 1 kg / cm ² and 1.0 second, 10 cc of red ink was injected into the bag, and the remaining one was heat sealed under the same conditions. Immediately after the bag was filled with the red ink, the bag surface was restrained under the conditions of a load of 20 kg and a time of 1 to 5 minutes, and the degree of leaching of the red ink into the seal portion was evaluated. The heat sealing width was 10 mm. The evaluation criteria are as follows.

[Evaluation Criteria] ◎: No leaching out of the bag for 5 minutes ○: No leaching out of the bag for 1 minute △: Leach out of the bag within 1 minute ×: Leach out of the bag when pressure is applied

Example 1 A linear low density polyethylene of hexene-1 (5.4% by weight) copolymerized with a Ziegler catalyst as a resin for a laminate layer [density = 0.934 g / cm ³ , weight average molecular weight / Number average molecular weight = 3.5, melt index (190
C.) = 2.0 g / 10 min] as a resin for the base layer, 0.03% by weight of erucic acid amide, 0.09% by weight of ethylenebisoleic acid amide, and 0.70% by weight of spherical zeolite having an average particle size of 4 μm. Hexene-1 (11.0 wt%) copolymerized linear low density polyethylene [density = 0.912 g / cm ³ , weight-based gold molecular weight / number average molecular weight = 3.5, melt index] (19
0 ° C.) = 2.0 g / 10 min], and as the sealing layer resin, 0.02% by weight of erucic acid amide, 0.10% by weight of ethylenebisoleic acid amide, and spherical cross-linked polymethylmetha having an average particle size of 5 μm. Acrylate particles 0.50% by weight
And linear low-density polyethylene of octene-1 (12.0% by weight) copolymerization containing 1.00% by weight of spherical cross-linked polymethylmethacrylate particles having an average particle size of 10 μm and produced using a metallocene catalyst [density = 0 .905 g / cm
³ , weight average molecular weight / number average molecular weight = 2.0, melt index (190 ° C.) = 3.0 g / 10 minutes],
After laminating the laminate layer and the seal layer with an extruder of 65 mmφ and the base layer with 90 mmφ at 220 ° C.,
A multi-manifold type three-layer T die was used to form a film so that the thickness ratio of the laminate layer, the base layer, and the seal layer was 1/8/1 to obtain a linear low-density polyethylene-based film of 50 μm.

(Examples 2 to 4, Comparative Examples 1 to 11) A resin composition having the content shown in Table 1 was formed into a film in the same manner as in Example 1 to form a linear low density polyethylene film having a thickness of 50 μm. Obtained. The average density of the resin composition is also shown in Table 1.

[0063]

[Table 1]

In Table 1, ^* , ^** , and ^*** indicate the following, respectively.

^* % By weight relative to 100% by weight of linear low-density polyethylene in each layer ^** Mw / Mn: weight average molecular weight / number average molecular weight ^*** average density = (laminate layer resin density x laminate layer ratio) + (base layer Resin density x base layer ratio) + (seal layer resin density x seal layer ratio)

The film (raw film) obtained in Examples 1 to 4 and Comparative Examples 1 to 11 and a laminate of the raw film and a biaxially stretched nylon film of 15 μm had haze value and blocking resistance. The dynamic friction coefficient, Young's modulus, sealing start temperature, bag making speed, hot filling temperature, blocking resistance, and bag making airtightness were measured. The results are shown in Table 2.
Shown in.

Here, the laminated product with the nylon film is a laminated film obtained by laminating together the laminate layer surface of the original film and the nylon film surface.

[0068]

[Table 2]

The linear low-density polyethylene-based film obtained in this example had a low sealing start temperature, good low-temperature thermal adhesiveness, high-speed bag making at low temperature, and appropriate mechanical suitability. It was a thing. Furthermore, the hot filling temperature is high and the hot filling suitability is excellent. Further, it has good blocking resistance and roll blocking resistance, and has sufficient anti-blocking property without using an anti-blocking agent such as starch powder, which is extremely high quality as an automatic packaging film or sealant. It was

On the other hand, Comparative Examples 1, 2, 7, 8, and 10
The film obtained in (1) had good hot-filling suitability at high temperatures, but had a high sealing start temperature and was inferior in high-speed bag-making property and bag-making airtightness, and was not practical.

The films obtained in Comparative Examples 5, 6 and 9 had a low sealing start temperature and good hot-filling suitability at high temperatures, but had poor airtightness during bag making, and thus had high-speed bag making suitability. It was inferior.

Further, the films obtained in Comparative Examples 3, 4 and 11 had a low sealing start temperature and a good bag airtightness during bag making, and showed excellent properties for high-speed bag making, but No satisfactory mechanical strength was obtained, and satisfactory hot-filling suitability and blocking resistance were not obtained.

[0073]

Linear low density polyethylene film of the invention of claim 1, wherein according to the present invention, there is rigid, has appropriate mechanical strength, and low temperature heat-adhesive, slipping property, Ru excellent Tei blocking resistance .

The linear low-density polyethylene film according to the second aspect of the present invention can be variously combined in the type of linear low-density polyethylene used, the combination of various additives, and the like.

The linear low density polyethylene film according to the third aspect of the present invention has rigidity and excellent blocking resistance.

The linear low-density polyethylene film according to the fourth aspect of the present invention is well balanced in terms of film rigidity and bag-breakage resistance.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsutomu Isaka 2-8 Dojimahama, Kita-ku, Osaka Toyo Spinning Co., Ltd. (56) Reference JP-A-7-258348 (JP, A) JP-A 5-331324 (JP, A) JP-A 1-216839 (JP, A) JP-A 6-8320 (JP, A) JP-A 4-189837 (JP, A) JP-A 61-181837 (JP, A) JP-A-49-23245 (JP, A) JP-A-3-138148 (JP, A) JP-A-8-511744 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) ) C08J 5/18

Claims (4)

(57) [Claims] 1. A density of 0.860 to 0.925 g / cm.
³ , linear with a weight average molecular weight / number average molecular weight of 1 to 3
A seal layer made of low-density polyethylene and the seal layer are constructed.
Higher density than linear low-density polyethylene
Multilayer composed of base layer made of high density polyethylene
And the average particle size in the sealing layer is 3 to 15 μm.
0.3 to 2 types of inert particles having different average particle sizes
Containing 2.0% by weight, Young's modulus is 1000 to 220
A linear low-density polyethylene-based film having a sealing start temperature of 95 ° C. or lower at 0 kg / cm ² . 2. The linear low-density polyethylene-based film according to claim 1 , wherein the substrate layer is a film layer formed of two or more multilayer linear low-density polyethylene. 3. The linear low-density polyethylene-based film according to claim 1 or 2, wherein the linear low-density polyethylene constituting the multilayer body has an average density of 0.900 to 0.930. 4. The thickness of the sealing layer is 3 times the total thickness of the multilayer body.
The linear low-density polyethylene-based film according to claim 1, 2 or 3 , wherein the linear low-density polyethylene-based film is about 20%.