JP2000052514A - Laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate excellent in capacities such as low temp. heat sealability, heat seal strength, hot tackiness or the like and improved in processability. SOLUTION: A laminate contains a layer comprising a resin compsn. containing 50-99 wt. % of an ethylene/α-olefin copolymer (component A) produced by using a metallocene catalyst and 1-50 wt.% of high pressure low density polyethylene (component B) with MFR of 0.1-20 g/10 min and a density of 0.915-0.93 g/cm3 and characterized by that MFR is 5-25 g/10 min, density is 0.87-0.932 g/cm3, ME (3g) is 1.2-2.3 and MT is 1.0 g or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film,
The present invention relates to a laminate having improved workability and excellent low-temperature heat sealability, heat seal strength, and hot tack properties.

[0002]

2. Description of the Related Art Hitherto, a high-pressure low-density polyethylene (hereinafter simply referred to as "LDPE") obtained by polymerizing ethylene under high temperature and high pressure using a radical initiator has been used as a film for lamination. This LDPE provides a stable film at the time of molding and is excellent in high-speed workability, but is inferior in low-temperature heat sealability, heat seal strength and hot tack property. For this reason, ethylene-vinyl acetate copolymer (EVA) or the like is used as an alternative material to the LDPE, and such an EVA is excellent in low-temperature heat sealability, but other disadvantages of the LDPE. The heat seal strength and hot tack property cannot be improved, and heat at around 280 ° C., which is a normal forming temperature during laminating processing, cannot be achieved. The lack in qualitative, are decomposed during lamination there is a problem that generates a characteristic odor.

[0003] Thereafter, a medium pressure method using a Ziegler catalyst,
For example, a copolymer of ethylene and an α-olefin produced by a method described in JP-B-56-18132, etc., a so-called linear low-density polyethylene (hereinafter simply referred to as “LL”)
DPE ". ) Appeared. However, this LL
DPE is excellent in heat seal strength, hot tack property, impact strength, and the like, and has the ability to improve the above-mentioned disadvantages of LDPE, but has a serious problem in workability. That is, compared to conventional LDPE, LLDPE has the drawback that high shear viscosity in the extruder increases the resin pressure and makes high-speed processing difficult, or the power required by the extruder significantly increases. there were. Also,
There was also a drawback that the film could not be put to practical use due to uneven thickness and width of the film due to low melt tension. However, it has been proposed that these disadvantages can be improved by the technique of blending LLDPE and LDPE described in JP-A-58-194935.

[0004]

Materials which can satisfy workability by such an improved technique by blending are, on the contrary, low-temperature heat sealability, heat seal strength,
Hot tack properties and the like tend to be insufficient, and it has been desired to develop a material having a good balance between these properties and workability. On the other hand, in recent years, a special material having a narrower molecular weight distribution and composition distribution than conventional LLDPE has been obtained by using a new catalyst described in JP-A-58-19309. The present inventors,
A study was conducted to apply this special LLDPE as a material for extrusion lamination, and the above-mentioned low-temperature heat sealability, heat seal strength, and hot tack performance were significantly better than conventional LLDPE. However, it was found that the defect of workability, which is a drawback of LLDPE, was significantly worse than that of the conventional one, resulting in a material having a much worse balance. The object of the present invention is to improve processability while maintaining such excellent performance, and to excel in performance such as low-temperature heat sealing property, heat sealing strength and hot tack property, which are not achieved by the above conventional materials, and An object of the present invention is to provide a film having improved processability.

[0005]

Means for Solving the Problems [Summary of the Invention] The present inventors have made intensive studies in view of the above problems, and as a result, have found that LLDPE produced using a specific catalyst and special LDPE are used.
The present invention has been completed based on the finding that the object of the present invention can be achieved by a resin composition having specific physical properties. That is, the present invention
50 to 99% by weight of an ethylene / α-olefin copolymer produced using a metallocene catalyst, and an MFR of 0.1 to
20 g / 10 min; density 0.915 to 0.93 g / cm
A ³ high pressure process consists of a low density polyethylene 50 wt%, MFR is 5 to 25 g / 10 min; density 0.87
0.93 g / cm ³ ; ME (3 g) is 1.2 to
2.3: a laminate including a layer made of a resin composition having an MT of 1.0 g or more.

[0006]

DETAILED DESCRIPTION OF THE INVENTION [1] Constituents (1) Ethylene / α produced using a metallocene catalyst
-Olefin Copolymer (Component A) (a) Properties The ethylene / α-olefin copolymer of Component A constituting the resin composition as a raw material for forming a film of the present invention has the following physical properties: Preferably, there is.

MFR The ethylene / α-olefin copolymer used in the present invention has an MFR (Melt Flow Rate) of 2 to 30 g / 1 according to JIS K7210.
0 min, preferably 5 to 25 g / 10 min, particularly preferably 10 to 22 g / 10 min, most preferably 13 to 20 g / min.
This shows physical properties for 10 minutes. When the MFR is larger than the above range, film formation becomes unstable. If the MFR is too small, the film will break during molding.

Density The ethylene / α-olefin copolymer used in the present invention has a density according to JIS K7112 of 0.935 g /
cm ³ or less, preferably 0.87 to 0.92 g / cm ³ ,
Particularly preferably 0.88~0.913g / cm ^3, and most preferably shows the physical properties of 0.89~0.91g / cm ^3. If the density is higher than the above range, the low-temperature heat sealability becomes poor. On the other hand, if the density is too low, the film surface becomes sticky and cannot be put to practical use, and the lower limit is usually about 0.86 g / cm ³ .

The peak temperature of an elution curve obtained by temperature-rise elution fractionation The ethylene / α-olefin copolymer used in the present invention has a temperature-rise elution fractionation (TREF: Temperature Risi).
The elution curve obtained by ng Elution Fractionation is preferably as described below. The maximum peak temperature is from 20 to 85 ° C, particularly preferably from 30 to 75 ° C, most preferably from 40 to 70 ° C, and the [peak height] / [1/2 of the peak height of this maximum peak] In (H / W) is 1 or more, preferably 1 to 20, particularly preferably 1 to 15, and most preferably 1 to 10. When the maximum peak temperature of the elution curve exceeds the above-mentioned temperature, the low-temperature heat sealability becomes poor, so that it is not practical. If the H / W is less than the above value, the stickiness component increases and the heat sealability becomes poor over time, which is not practical.

[0010] Measurement of elution curve by temperature-rise elution fractionation [Temperature Rising Elution Fract]
ionation: TREF) is described in “Journal of App
lied Polymer Science, Vol 26, 4217-4231 (1981) ”or“ Polymer Symposium Proceedings 2P1C09 (1985) ”. TR
According to the principle of EF measurement, first, a polymer to be measured is completely dissolved in a solvent. Thereafter, cooling is performed to form a thin polymer layer on the surface of the inert carrier. Such a polymer layer is likely to be crystallized inside (the side close to the inert carrier surface)
In addition, what is difficult to crystallize is formed on the outside. Next, when the temperature is increased continuously or stepwise, in the low temperature stage, the polymer is eluted from the amorphous portion in the target polymer composition, that is, a polymer having a high degree of short-chain branching having a polymer,
As the temperature rises, those with a low degree of branching gradually elute, and finally the linear portion without branching elutes, ending the measurement. By detecting the concentration of the eluted component at each temperature, the composition distribution of the polymer can be seen from a graph drawn by the amount and temperature of the elution.

In the above TREF measurement, the integrated elution amount obtained by integrating the weight fraction of the eluted material at each elution temperature is 10% or less at an elution temperature of 10 ° C. and 90% at 90 ° C. %, Preferably 10% at an elution temperature of 20 ° C.
At 95 ° C., particularly preferably at least 5% at an elution temperature of 20 ° C.
It is 97% or more at ° C.

Q Value This ethylene / α-olefin copolymer is obtained by size exclusion chromatography (Size Exclusion Chromatography).
: SEC), the compound having a physical property of Q value (weight average molecular weight / number average molecular weight) of 4 or less, preferably 3 or less, particularly preferably 2.5 or less. The Q
If the value is larger than the above range, the appearance of the film tends to deteriorate.

(B) Production of Ethylene / α-Olefin Copolymer The production method of such a linear low-density polyethylene is described in JP-A-58-19309, JP-A-59-95292 and JP-A-60-95292.
No. 35005, No. 60-35006, No. 60-350
No. 07, No. 60-35008, No. 60-35009
No. 61-130314, JP-A-3-1630088
No. 4,049,436, U.S. Pat. No. 5,055,438 and WO 91/04257, namely metallocene catalysts, in particular metallocene-alumoxane catalysts. Or, for example, International Publication W
Using a catalyst comprising a metallocene compound as disclosed in O92 / 01723 or the like and a compound which reacts with a metallocene compound described below to form a stable anion,
This is a method of copolymerizing ethylene as the main component and α-olefin as the auxiliary component. The compound which becomes a stable anion by reacting with the above-mentioned metallocene compound is an ionic compound or an electrophilic compound formed from an ion pair of a cation and an anion, and becomes a stable ion by reacting with a metallocene compound. It forms a polymerization active species.

Among them, the ionic compound is represented by the following general formula (I). General formula (I) [Q] m + [Y] m- (m is an integer of 1 or more) Q is a cation component of an ionic compound, and is a carbonium cation, tropylium cation, ammonium cation, oxonium cation, or sulfonium cation ,
Examples thereof include a phosphonium cation and the like, and further, a metal cation or an organic metal cation which is easily reduced by itself. These cations are described in JP-T-Hei 1-50.
Not only a cation capable of providing a proton as disclosed in 1950 and the like, but also a cation that does not provide a proton may be used. Specific examples of these cations include triphenylcarbonium, diphenylcarbonium, cycloheptatrienium, inidenium,
Triethylammonium, tripropylammonium,
Tributylammonium, N, N-dimethylanilinium, dipropylammonium, dicyclohexylammonium, triphenylphosphonium, trimethylphosphonium, tri (dimethylphenyl) phosphonium, tri (methylphenyl) phosphonium, triphenylsulfonium, triphenyloxonium, triethyloxo And silver, gold, platinum, palladium, mercury, and ferrocenium ions.

Y is an anionic component of an ionic compound, which is a component which reacts with a metallocene compound to form a stable anion, such as an organic boron compound anion, an organic aluminum compound anion, an organic gallium compound anion, and an organic phosphorus compound. Anions, organic arsenic compound anions, organic antimony compound anions, and the like, specifically, tetraphenylboron, tetrakis (3,4,
5-trifluorophenyl) boron, tetrakis (3,
5-di (trifluoromethyl) phenyl) boron, tetrakis (3,5- (t-butyl) phenyl) boron, tetrakis (pentafluorophenyl) boron, tetraphenylaluminum, tetrakis (3,4,5-trifluorophenyl) ) Aluminum, tetrakis (3,5-
Di (trifluoromethyl) phenyl) aluminum, tetrakis (3,5-di (t-butyl) phenyl) aluminum, tetrakis (pentafluorophenyl) aluminum, tetraphenylgallium, tetrakis (3
4,5-trifluorophenyl) gallium, tetrakis (3,5-di (trifluoromethyl) phenyl) gallium, tetrakis (3,5-di (t-butyl) phenyl)
Gallium, tetrakis (pentafluorophenyl) gallium, tetraphenylphosphorus, tetrakis (pentafluorophenyl) phosphorus, tetraphenylarsenic, tetrakis (pentafluorophenyl) arsenic, tetraphenylantimony, tetrakis (pentafluorophenyl) antimony, decaborate, Decaborate, carbado decaborate, decachloro decaborate and the like.

The electrophilic compound is a compound known as a Lewis acid compound, which reacts with a metallocene compound to form a stable anion to form a polymerization active species. Examples include metal oxides known as solid acids. Specific examples include magnesium halide and Lewis acidic inorganic oxide.

Α-olefin Here, the α-olefin is an α-olefin having 3 to 18 carbon atoms.
Olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene,
4-methylpentene-1, 4-methylhexene-1,
4,4-dimethylpentene-1 and the like. Among these α-olefins, 2 to 60% by weight of one or more α-olefins having 4 to 12 carbon atoms, particularly preferably 6 to 10 carbon atoms, and 40 to 98% by weight of ethylene are copolymerized. Is preferred.

Copolymerization Examples of the polymerization method include a gas phase method, a slurry method, a solution method, and a high pressure ionic polymerization method. Among these, a solution method and a high-pressure ionic polymerization method are preferred, and production by a high-pressure ionic polymerization method is particularly preferred. The high-pressure ion polymerization method is described in JP-A-56-18607 and JP-A-58-18607.
225106, the pressure is 1
00 kg / cm ² or more, preferably 200 to 2,000
kg / cm ² , temperature is 125 ° C. or higher, preferably 130 ° C.
This is a method for continuously producing an ethylene polymer, which is carried out under a reaction condition at a temperature of from 250 to 250C, especially from 150 to 200C.

(2) High pressure method low density polyethylene: LDP
E (Component B) (a) Properties The high-pressure low-density polyethylene of Component B constituting the resin composition of the present invention has the following physical properties. Component B preferably has the following physical properties. MFR The high-pressure low-density polyethylene used in the present invention is JI
MFR by SK7210 (Melt flow rate: Me
lt Flow rate: 0.1 to 20 g / 10 min.
Preferably 1 to 13 g / 10 min, particularly preferably 2 to 1 g
It shows physical properties of 3 g / 10 minutes. When the MFR is larger than the above range, the film formation becomes unstable. Also, MF
If R is less than the above range, extrudability and film appearance will be poor.

Density The high-pressure low-density polyethylene used in the present invention is JI
The density by SK7112 is 0.915 to 0.93 g /
cm ³ , preferably 0.916 to 0.925 g / cm ³ ,
Particularly preferred are those exhibiting physical properties of 0.918 to 0.922 g / cm ³ . If the density is higher than the above range, the low-temperature heat sealability becomes poor. On the other hand, if the density is lower than the above range, stickiness increases on the film surface.

A memory effect (ME: Memory E)
ffect: Restoring effect) The high-pressure low-density polyethylene used in the present invention is M
E (3 g) preferably has physical properties of 1.6 or more, preferably 1.8 or more, particularly preferably 2.0 or more, and most preferably 2.3 or more. If the ME is smaller than the above value, the film formation becomes unstable, which is not preferable. Note that M
The measurement of E (3 g) is carried out as follows, using a melt indexer used in JIS K7210 and setting measurement conditions to a cylinder temperature of 240 ° C. and a constant-rate extrusion rate of 3 g / min. The device is filled with the sample, only the piston is loaded and a defined extrusion rate is applied after 6 minutes. Next, a measuring cylinder containing ethyl alcohol is placed directly below the orifice, and a straight extrudate is collected. Collected extrudate diameter (D) was measured with a micrometer, the olefin-diameter of the die as D _0, ME is obtained from the following equation. ME = D / D ₀

Melt tension (MT: Melt Tensi
on: melt tension at break) The high-pressure low-density polyethylene used in the present invention is MT
Is at least 1.5 g, preferably at least 2.5 g, particularly preferably at least 5 g. If the MT is too small, the effect of improving workability is reduced, which is not preferable.

Relationship between ME and MT: In the high-pressure low-density polyethylene used in the present invention, ME (3 g) and MT have the following relationship. ME ≧ [0.05 × MT + 1.3], preferably ME ≧ [0.05 × MT + 1.5] Unless this relationship is satisfied, the effect of improving workability is reduced, which is not preferable.

Q value This high-pressure low-density polyethylene is obtained by Size Exclusion Chromatography (SE).
Those exhibiting physical properties of Q value (weight average molecular weight / number average molecular weight) determined by C) of 5 to 30, particularly preferably 7 to 25, and most preferably 10 to 20 are preferred. The Q
If the value is larger than the above range, the film appearance tends to deteriorate, which is not preferable. On the other hand, if the Q value is too small, the film formation tends to be unstable, which is not preferable.

(B) Specific examples of high-pressure low-density polyethylene Such high-pressure low-density polyethylene can be appropriately selected from commercial products and used. Among them, a reaction temperature of 220 ° C. or more and a reaction pressure of 1, It is preferable to use polyethylene produced by an autoclave method at 700 kg / cm ² or less.

[II] Ratio of Component A to Component B The proportion of the ethylene / α-olefin copolymer of Component A and the high-pressure low-density polyethylene of Component B is 50 to 99% by weight of Component A. 1 to 50% by weight of component B, preferably 55 to 95% by weight of component A and 5 to 45% by weight of component B, particularly preferably 60 to 85% by weight of component A and 15 to 40% by weight of component B is there. If the compounding ratio of the component B is less than the above range, the effect of improving the processability becomes insufficient. On the other hand, if the mixing ratio of the component A is less than the above range, heat sealing properties, hot tack properties and the like will be poor.

[III] Production of resin composition (1) Compounding The resin composition for lamination of the present invention is prepared by mixing the ethylene / α-olefin copolymer of the component A with the same method as in the usual production method of the resin composition. It can be produced by blending component B with a high-pressure low-density polyethylene. Specifically, component A and component B are melted and kneaded using an extruder, a Brabender plastograph, a Banbury mixer, a kneader blender, or the like, to obtain a resin composition for lamination. The resin composition is usually formed into pellets by an ordinary method, for example, an extruder.

(2) Other Additives In the resin composition of the present invention, auxiliary additives generally used for resin compositions, such as antioxidants, heat stabilizers, light stabilizers, and ultraviolet absorbers , A neutralizing agent, an anti-fogging agent, an anti-blocking agent, a slip agent, a coloring agent and the like.

(3) Physical Properties of Resin Composition The resin composition thus obtained has an MFR of 5-2.
5 g / 10 min, preferably 8-20 g / 10 min;
Density 0.87~0.932g / cm ^3, there preferably ^{0.89~0.912g / cm 3; ME (3g} )
Is from 1.2 to 2.3, preferably from 1.5 to 2.0;
The MT must be at least 1.0 g, preferably at least 1.5 g. When the MFR is larger than the above range, the film formation becomes unstable, and when the MFR is smaller than the above range, the extrudability and spreadability become poor, which is not preferable. When the density is higher than the above range, the low-temperature heat sealability becomes poor, and when the density is lower than the above range, the film surface becomes sticky, which is not preferable. If the ME is larger than the above range, the extensibility becomes poor, and if it is smaller than the above range, the neck-in becomes poor, which is not preferable. If the MT is smaller than the above range, the effect of improving workability is reduced, which is not preferable. The Q value is not particularly limited, but is preferably 3 to 6, and particularly preferably 3.0 to 5.2.

[IV] Forming Process The film used for the layer constituting the laminate of the present invention is manufactured by forming using a pellet made of the above resin composition. As a method for producing such a film, a conventional method can be employed. Examples include air-cooled inflation molding, air-cooled two-stage cooling inflation molding, T-die film molding, and water-cooled inflation. Film used for the layer constituting the laminate of the present invention,
Various packaging laminates (films) can be obtained by dry coating, extrusion lamination, sandwich lamination, co-extrusion, etc., by extrusion coating or co-extrusion with various substrates. . In particular, it can be laminated to a substrate by an extrusion lamination method to form a laminate (film). Moreover, it can also be used as a sandwich laminate base material of various base materials and a sealant base material.

Examples of the above-mentioned various substrates include high-molecular polymers which can be made into paper, aluminum foil, cellophane, woven fabric, non-woven fabric and film, for example, high-density polyethylene,
Medium, low density polyethylene, ethylene / vinyl acetate copolymer, ethylene / acrylate copolymer, ionomer, polypropylene, poly-1-butene, poly-4-
Olefin polymers such as methylpentene-1; vinyl copolymers such as polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylate, and polyacrylonitrile; nylon 6, nylon 66, nylon 7, nylon 10,
Polyamides such as nylon 11, nylon 12, nylon 610, and polymethaxylylene adipamide; polyesters such as polyethylene terephthalate, polyethylene terephthalate / isophthalate and polybutylene terephthalate; polyvinyl alcohol; ethylene-vinyl alcohol copolymer; and polycarbonate. be able to.

[0032]

EXAMPLES The present invention will be described more specifically with reference to experimental examples including examples and comparative examples. [I] Measurement and evaluation methods of physical properties Measurement and evaluation of physical properties in Examples and Comparative Examples were performed by the following methods. (1) Measurement of physical properties (a) MFR: based on JIS K7210 (190
(B) Density: JIS K7112 (c) ME (Memory Effect): JIS K
The measurement was carried out using a melt indexer used in No. 7210 at a cylinder temperature of 240 ° C. and a constant rate extrusion rate of 3 g / min. The device is filled with the sample, only the piston is loaded and a defined extrusion rate is applied after 6 minutes. Next, a measuring cylinder containing ethyl alcohol is placed directly below the orifice, and a straight extrudate is collected. Collected extrudate diameter (D) was measured with a micrometer to determine the ME by the following equation orifice diameter of the die as D _0. ME = D / D ₀

(D) Measurement of elution curve: Temperature rising elution fraction in the present invention (Temperature Rising Elution Fract)
The peak of the elution curve due to ionization (TREF) is obtained by completely dissolving the polymer once at a high temperature and then cooling to form a thin polymer layer on the surface of the inert carrier, and then increasing the temperature continuously or stepwise. To collect the eluted components,
The concentration is continuously detected, and the composition distribution of the polymer is measured by the peak of a graph (elution curve) drawn by the elution amount and the elution temperature.

The elution curve was measured as follows. Cross sorter (Mitsubishi Chemical Corporation)
The measurement was carried out according to the measurement method of the attached operation manual using CFC T150A). The cross separation apparatus includes a temperature-rise elution separation (TREF) mechanism that separates a sample by using a difference in dissolution temperature, and a size exclusion chromatograph (Size Exclusion) that further separates the separated fractions by molecular size.
Chromatography (SEC) is connected online.

First, a sample (copolymer) to be measured was dissolved in a solvent (o-dichlorobenzene) at a concentration of 4 mg /
The solution is dissolved at 140 ° C. so as to obtain a volume of 100 ml, and the solution is injected into a sample loop in the measurement device. The following measurements are performed automatically according to the set conditions. The sample solution held in the sample loop is separated using the difference in dissolution temperature.
0.4 ml is injected into a REF column (a stainless steel column packed with glass beads as an inert carrier and having an inner diameter of 4 mm and a length of 150 mm attached to the apparatus). Next, the sample is cooled at a rate of 1 ° C./min from a temperature of 140 ° C. to a temperature of 0 ° C. and coated on the inert carrier. At this time,
A polymer layer is formed on the surface of the inert carrier in the order from the highly crystalline component (the one that easily crystallizes) to the low crystalline component (the one that hardly crystallizes). After the TREF column is kept at 0 ° C. for another 30 minutes, 2 ml of the dissolved component at a temperature of 0 ° C.
At a flow rate of 1 ml / min from a TREF column to an SEC column (3 AD80M / S manufactured by Showa Denko KK). While fractionation by molecular size is being performed at SEC,
In the TREF column, the temperature is raised to the next elution temperature (5 ° C.)
Hold at that temperature for about 30 minutes. The measurement of each elution section by SEC was performed at intervals of 39 minutes. The elution temperature is raised stepwise at the following temperature. 0, 5, 10, 15, 20, 25, 30, 35, 40,
45, 49, 52, 55, 58, 61, 64, 67, 7
0, 73, 76, 79, 82, 85, 88, 91, 9
4,97,100,102,120,140 ° C

The solution fractionated by the molecular size in the SEC column was measured for absorbance in proportion to the concentration of the polymer using an infrared spectrophotometer attached to the apparatus (wavelength: 3.42 μm, detected by stretching vibration of methylene). A chromatogram of the elution temperature category is obtained. Using the built-in data processing software, the base line of the chromatogram of each elution temperature section obtained by the above measurement is drawn and processed. The area of each chromatogram is integrated and an integrated elution curve is calculated. Also,
This integral elution curve is differentiated with respect to temperature to calculate a differential elution curve. The drawing of the calculation result is output to the printer.
The plot of the output differential elution curve shows the elution temperature of 1 on the horizontal axis.
89.3 mm per 00 ° C., differential amount on the vertical axis (total integrated elution amount is set to 1.0, and the change amount at 1 ° C. is defined as the differential amount)
The measurement was performed at 76.5 mm per 0.1. Next, the peak height (mm) of this differential elution curve is reduced to a half height width (mm).
The value divided by was defined as H / W.

(E) Q value: Measured using Size Exclusion Chromatography (SEC) under the following measurement conditions, and the weight average molecular weight /
The Q value was determined from the number average molecular weight. A universal calibration curve was made with monodisperse polystyrene and calculated as the molecular weight of linear polyethylene. Model: Waters Model 150C GPC Solvent: o-dichlorobenzene Flow rate: 1 ml / min Temperature: 140 ° C. Measurement concentration: 2 mg / ml Injection volume: 200 μl Column: AD80M / S, 3 pieces, manufactured by Showa Denko KK

(2) Evaluation method (a) Surging: At the time of extrusion lamination molding, kraft paper was used as the base material and the thickness was 20 μm on kraft paper.
Extrusion laminate the sample at m. Surging is L / 2 when the width of the extruded and laminated film is L.
Is good when it fluctuates below 1.5 mm, and bad when it fluctuates above 1.5 mm. (B) MT (Melt Tension: melt tension at break): at a test temperature of 190 ° C. by Capillograph 1-B manufactured by Toyo Seiki Co., Ltd.
The extrusion speed is 1 cm / min, and the take-up speed at the time of taking out the extruded molten resin is gradually increased to obtain the stress when the resin filament breaks. The die diameter used was
8.00 mm length, 2.095 mm inside diameter, 9.50 outside diameter
mm.

(C) Resin pressure: Measured by a resin pressure gauge attached to the die head of the extruder during extrusion lamination. (D) Neck-in: When extrusion lamination is performed in the same manner as in the evaluation of surging, a sample is extrusion-laminated to a thickness of 20 μm on the kraft paper using the base material as kraft paper. Neck-in at the time of the width of the L ₀ of the effective width of the die was coated on Kraft paper film is L, it is obtained from L ₀ -L.

(E) Heat sealing strength: After heat sealing with a hot plate heat sealer manufactured by Toyo Seiki Co., Ltd. at a sealing temperature of 110 ° C., a sealing pressure of 2 kg / cm ² and a sealing time of 1 second, heat sealing with a tensile tester. Measure strength. (F) 3 kg load heat seal temperature: The above heat seal strength is measured, and a temperature at which the heat seal strength is obtained at 3 kg is defined as a 3 kg load heat seal temperature. (G) Hot tack property: As heat sealing conditions, seal bar dimensions 200 mm × 30 mm, sealing pressure 1 kg /
cm ² , sealing time 0.5 seconds, load 50 g, chuck pressure 1 kg / cm ² , sealing temperature from 90 ° C. to 150 ° C., heat sealing at 5 ° C. intervals, and after heat sealing,
In a state of being applied with a load of 50 g, the heat-sealed portion is left until the peeling completely stops, and the peeled length is read to the nearest 1 mm. The temperature width at which the peel distance was 1 mm to 2 mm is defined as hot tack. (H) Breaking-off take-off speed: Toyo Seiki Capillograph 1-
At B, at a test temperature of 190 ° C. and an extrusion speed of 1 cm / min, the take-up speed at the time of taking out the extruded molten resin was gradually increased, and the maximum take-up speed (m / min) when the resin filament was broken. Was measured. The die diameter used was 8.00 mm in length, 2.095 mm in inner diameter, and 9.50 mm in outer diameter.
It is.

[II] Experimental Examples Example 1 Production of Ethylene / α-Olefin Copolymer (Component A) The preparation of the catalyst was carried out by the method described in JP-A-61-130314. That is, to 2.0 mmol of the complex ethylene-bis (4,5,6,7-tetrahydroindenyl) zirconium dichloride, methylalumoxane (manufactured by Toyo Stoffer Co., Ltd.) was added 1,000 times as much as the above complex, and 10 liters of toluene. To prepare a catalyst solution, which was polymerized by the following method. A mixture of ethylene and 1-hexene was added to a stirred autoclave-type continuous reactor having an inner volume of 1.5 liters and the composition of 1-hexene was 80%.
%, And the pressure in the reactor was 1,60
The reaction was carried out at 160 ° C. while maintaining the pressure at 0 kg / cm ² . After the completion of the reaction, the MFR was 18 g / 10 min, and the density was 0.898.
g / cm ³ , Q value of 1.9, one peak in TREF elution curve, peak temperature of 50 ° C., H / W of the peak temperature of 1.5, ethylene / α-olefin copolymer (1-hexene content 22% by weight) was obtained.

Production of high-density low-density polyethylene (component B) Reaction temperature 260 ° C., reaction pressure 1500 kg / cm
_{In 2 above} , it was manufactured by an autoclave method. MFR is 4g /
10 minutes, density 0.92 g / cm ³ , ME 2.4, Q
A high pressure low density polyethylene with a value of 10 was obtained.

Production of Resin Composition As shown in Table 1, the above-mentioned linear low-density polyethylene (component A) and high-pressure-process low-density polyethylene (component B) were mixed with component A: component B = 75: 25 wt. %, And granulated at a molding temperature of 160 ° C. with a 40 mmφ single screw extruder to obtain a pellet-shaped resin composition comprising the component A and the component B.

Evaluation The pellet-shaped resin composition was extruded into a 30 μm thick film at a molding temperature of 280 ° C. using a 40 mmφ single screw extruder. Extrusion lamination coating was performed on the LDPE side of a laminate in which LDPE and a biaxially stretched nylon film having a thickness of 15 μm were laminated. Using this laminated three-layer film, the heat seal strength, the heat seal temperature under a load of 3 kg, and the hot tack property were measured. In the same manner, the neck-in measurement and surging evaluation of a laminate film obtained by extrusion-lamination coating with a thickness of 20 μm were performed using kraft paper instead of a biaxially stretched nylon film as a base material. Table 1 shows the obtained evaluation results.

Examples 2 to 13, 22 to 23 and Comparative Example 1
-8 A resin composition was obtained in the same manner as in Example 1 except that components A and B having physical properties shown in Table 1 were used. This was molded and evaluated. Table 1 shows the obtained evaluation results.

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

[Table 3]

[0049]

[Table 4]

[0050]

[Table 5]

Example 14 Preparation of ethylene / α-olefin copolymer (component A) That is, complex ethylene-bis (4,5,6,7-tetrahydroindenyl) zirconium dichloride
To 0 mmol, methylalumoxane (manufactured by Toyo Stuffer Co., Ltd.) was added 1,000 times as much as the above complex, and 1
A catalyst solution was prepared by diluting the solution to 0 liter, and polymerization was performed by the following method. A mixture of ethylene and 1-hexene was supplied to a 1.5-liter stirred autoclave continuous reactor so that the composition of 1-hexene was 80% by weight, and the pressure in the reactor was 1,600 kg / The reaction was carried out at 180 ° C. while maintaining the pressure at ² cm ² . After completion of the reaction, the MFR was 18 g / 10 min, the density was 0.890 g / cm ³ , the Q value was 2.1, and there was one peak in the TREF elution curve. The peak temperature was 50 ° C., and the peak temperature was H. / W was 1.5, and an ethylene / α-olefin copolymer (1-hexene content: 22% by weight) having a curve showing the presence of an elution amount other than the peak was obtained.

Production of high-density low-density polyethylene (component B) Reaction temperature 260 ° C., reaction pressure 1,700 kg / cm
^{In 2 above} , it was manufactured by an autoclave method. MFR is 4g /
10 minutes, density 0.92g / cm ³ , ME 2.5, Q
A high pressure low density polyethylene with a value of 10 was obtained.

Production of Resin Composition As shown in Table 2, the above-mentioned ethylene / α-olefin copolymer (Component A) and the high-pressure low-density polyethylene (Component B) were mixed with Component A: Component B = 75. : Compounded at a ratio of 25% by weight, granulated at a molding temperature of 160 ° C. with a 40 mmφ single screw extruder, ethylene / α-olefin copolymer (component A) and high-pressure low-density polyethylene (component B) And a pellet-shaped resin composition was obtained. Evaluation The laminate produced from the obtained resin composition was evaluated in the same manner as in Example 1. Table 2 shows the results.

Examples 15 to 21 and Comparative Examples 9 to 18 A resin composition was prepared in the same manner as in Example 14 except that components A and B having physical properties shown in Table 2 were used. Obtained. This was molded and evaluated. Table 2 shows the obtained evaluation results.

[0055]

[Table 6]

[0056]

[Table 7]

[0057]

[Table 8]

[0058]

[Table 9]

[0059]

As described above, the laminate of the present invention has a conventional L
Processability is improved compared to LDPE, and the effects of low-temperature heat sealability, heat seal strength, and hot tack properties are remarkably superior to those of conventional molding materials. Aquatic foods such as miso, pickles, soups, juices, frozen foods,
Food packaging and filling films for livestock meat, ham, etc., mini-packs for soy sauce, sauces, etc .; Pharmaceutical packaging and filling films for bag-in-boxes, infusion bags, etc .; mini-packs for shampoo, cosmetics, etc .; Packaging / filling film; very useful when used for various packaging or filling purposes in a wide range of applications such as various lid materials.

 ──────────────────────────────────────────────────続 き Continued on the front page (31) Priority claim number Japanese Patent Application No. 5-111695 (32) Priority date May 13, 1993 (1993.13.13) (33) Priority claim country Japan (JP) (72) Inventor Yoshiko Shichijo 1 Tohocho, Yokkaichi City, Mie Prefecture Inside Yokkaichi Research Institute, Mitsubishi Chemical Corporation

Claims (3)

[Claims] 1. An ethylene / α-olefin copolymer (component A) produced using a metallocene catalyst in an amount of 50 to 99% by weight, an MFR of 0.1 to 20 g / 10 min, and a density of 0.915 to 0. MFR containing 1 to 50% by weight of a high-pressure low-density polyethylene (component B) of 0.93 g / cm ^3.
Is 5 to 25 g / 10 min; density is 0.87 to 0.932 g
/ cm ³ ; ME (3 g) is 1.2 to 2.3; MT is 1.0
A laminate comprising a layer comprising a resin composition having a weight of at least g. 2. The laminate including a layer according to claim 1, wherein the relationship between ME and MT of the resin composition satisfies ME ≧ [0.2 × MT + 1]. 3. The resin composition having an MFR of 8 to 20 g /
10 minutes; density 0.89 to 0.912 g / cm ³ ; ME
(3g) is 1.5-2.0; MT is 1.5g or more, The laminated body containing the layer of Claim 1 or 2.