JPS60145844A - Laminated film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides poly-4-methyl-1-
This invention relates to a laminated film based on pentene.

Poly-4-methyl-1-pentene is characterized by its transparency, heat resistance,
Taking advantage of its chemical resistance, it can be used for chemical experiment equipment such as beakers and graduated cylinders, syringes for syringes, optical measurement cells,
It is used for baking cartons, etc. by coating on microwave oven trays or paper. However, although poly-4-methyl-1-pentene has a high melting point and good heat resistance, it has the drawback of poor heat sealability.

A method for improving heat sealing properties is to use resins such as polyethylene and polypropylene, which have a lower melting point and excellent heat sealing properties than poly(4-methyl-1-pentene), and poly(4-methyl-1-pentene).
-Methyl-1-pentene is the most common method, but polyethylene or polypropylene and poly-4-methyAl-1-pentene have poor adhesive properties even though they are the same polyoC fin, so it is difficult to simply laminate them together. It cannot be put to practical use at all by itself, and a urethane adhesive or the like is applied to the poly-4-methyl-1-pentene film as an anchoring agent.

Even if a polyethylene film or the like is laminated thereon, the poly-4-methyl-1-pentene film has poor surface wettability, the adhesive strength of the laminated film is low, and the heat-sealing properties have not been improved as much.

In view of this situation, the present inventor has conducted various studies to improve the heat-sealability of poly-4-methyl-1-pentene film. It was discovered that by using a specific propylene/α-olefin random copolymer as the adhesive layer, adhesive strength was improved and a laminated film with excellent heat sealability could be obtained, leading to the completion of the present invention. .

That is, the present invention provides poly4-methyl-1-pentene (A
At least one side of T 31 has a propylene content of 50 to 87 mol % and a heat of crystal fusion of 10 to 80 Joule/based on differential scanning calorimetry (DSC) thermal analysis.
g propylene-α-olefin random copolymer (B
The object of the present invention is to provide a laminated film with excellent heat-sealability, which is characterized by laminating a polyethylene (C) or polypropylene + D) layer or a mixture layer thereof via a layer (C) or a layer (D) or a mixture thereof.

Poly 4-methyl-1-pentene (A) used in the present invention is a homopolymer of 4-methyl-1-pentene or 4-methyl-1-pentene.
Methyl-1-pentene and other α-olefins such as ethylene, propylene, 1-butene, 1-hexene, 1-
4-Methyl-1- is a copolymer with α-olefin having 2 to 20 carbon atoms such as octene, 1-decene, 1-tetradecene, and 1-octadecene, and usually contains 85 mol% or more of 4-methyl-1-pentene. It is a polymer mainly composed of pentene. Melt flow rate of poly4-methyl-1-pentene (A) (MFR5 load: 5kas temperature: 260°C
) is preferably in the range of 0.5 to 200 g/10 m1n, but if it is less than 0.5 g710 win, the melt viscosity is high and the moldability is poor, and the MFR5 is 200H71
If it exceeds 0 min, the melt viscosity is low and the moldability is poor.
It also has low mechanical strength.

Propylene/α-olefin copolymer f used in the present invention
All means propylene content of 50 to 87 mol%
, preferably 60 to 80 mol% and a heat of crystal fusion of 10 to 80 to 78%, preferably 20 to 70 Joule/g, based on differential scanning calorimetry (DSO) thermal analysis, and preferably is midfielder
R2 (MFR2:AsTM I) 12381L) is 0.
It has a melting point of 5 to 200 g/10 m1rL, more preferably 2 to 50 g/10 m1n, preferably 90 to 130°C, preferably 110 to 125°C.

If the propylene content exceeds 87 mol% or the heat of crystal fusion exceeds 80 Joule/g, the adhesion to poly4-methyl-1-pentene (N) is poor, and polyethylene (0) or polypropylene ( DJ
The heat sealability is not improved even if laminated with. On the other hand, if the propylene content is 50 mol% or the heat of crystal fusion is 1
If it is less than 0Jnulθ/g, it has adhesive properties, but the adhesive strength is weak and the heat resistance is also poor, so there is little effect on improving heat sealability, and the heat resistance, which is the original characteristic of poly 4-methyl-1-pentene, is poor. This is not desirable as it may damage the

Additionally, those with MFR2 outside the above range may have poor moldability, and those with melting points outside the above range also tend to have poor adhesiveness.

In addition to the above-mentioned properties, the propylene/α-olefin random copolymer (B) used in the present invention also has microisotoughness (hereinafter M
]: Abbreviated as T) is 0.7 or more, more preferably 0.8 or more, and boiling n-hebutane insoluble content is 5% by weight or less, furthermore 3% by weight.
The following are preferred. If a film with M/T of less than 0.7 is used, low molecular weight substances may bleed out to the film interface after aging, reducing adhesive strength, and there is a large amount of content insoluble in boiling n-hebutane. This is because there are many components in which propylene is block-polymerized, and when such a copolymer is used, the effect of improving adhesion may be small.

In the random copolymer (B), the α-olefin copolymerized with propylene is usually an α-olefin having 2 to 20 carbon atoms excluding propylene, and specifically, for example, ethylene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1
Examples include -tetradecene, 1-octadecene, etc. Among these, those having 4 to 10 carbon atoms are particularly preferred.

The heat of fusion of the random copolymer (B) in the present invention is measured using a differential scanning calorimeter using a specific heat curve of the copolymer in a completely molten state (preferably 160°C or higher and 240°C or higher).
This is a value calculated using a straight line obtained by directly extrapolating the specific heat curve (shown below) to the low temperature side as a baseline.

The heat of fusion and melting point are measured under the following measurement conditions. That is, after leaving the sample at 200°C for 5 minutes,
Cool to -IQ-C at a rate of -40°C and leave for 5 minutes at -IQ-C. Then, at a heating rate of 20"C/min,
Measurements are taken from 0°C to 200″C.

Miku-a isotacticity is a value obtained by focusing on the 6 propylene chains using O1aFa gas resonance spectroscopy, and quantifying the fraction in which 6 propylene chains are arranged in an isotactylene chain.

The boiling n-hebutane insoluble fraction ff1ffl is determined by the following method. That is, a strip sample and glass beads of about 1 mm x 1 mm x 1 mm were passed through a cylindrical glass filter (
G3) and extracted using a Soxhlet extractor for 14 hours. In this case, the reflux frequency is approximately 75 minutes at a time. The weight percent of insoluble matter is determined by weighing the molten part or insoluble matter.

The propylene/α-olefin random copolymer (B) having a propylene content of 50 to 87 mol % and having the above-mentioned properties is, for example, fa) a composite containing at least magnesium, titanium, and halogen, (b) a periodic Organometallic compounds of Group 1 to Group 6 metals and t
It is obtained by random copolymerization of propylene and α-olefin using a catalyst formed from a Ql electron donor. Part or all of the electron donor IC) may be immobilized to part or all of the complex +a), or may be brought into preliminary contact with the organometallic compound (bl) prior to use. Particularly preferably, part of the electron donor to+ is fixed in the complex (a), and the remaining part can be directly added to the polymerization system or can be added to an organometallic compound (
This is an embodiment in which it is used in preliminary contact with bl. in this case,
The electron donor immobilized on the complex 1a) and the electron donor used by being added directly to the polymerization system or used after being brought into preliminary contact with bl may be the same or different.

Polyethylene tC used in the present invention, ethylene homopolymer or ethylene and other α-olefins, specifically, for example, propylene, 1-butene, 4-methyl-1
- a copolymer with pentene, 1-hexene, 1-octene, 1-decene, 1-tetradecene, 1-octadecene, etc., or a vinyl compound such as vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, etc.; It is a crystalline polymer mainly composed of ethylene, usually having an ethylene content of 92 mol% or more, preferably 95 mol% or more. Specific examples of these polyethylenes (0) include high-pressure low density polyethylene (so-called LDPE), ethylene-propylene copolymer, ethylene-1-butene copolymer, and ethylene-4-methyl-1-pentene copolymer. and ethylene-1-hexene copolymer (hereinafter referred to as HLLDPIC), high-density polyethylene (so-called Hnpx), ethylene/vinyl acetate copolymer, ethylene/acrylic acid copolymer, and the like. Further, the polyethylene (03) used in the present invention may be graft-modified with an unsaturated carboxylic acid such as maleic anhydride or maleic acid. Among these, LDPK,
Ethylene/α-olefin copolymers, ethylene/vinyl acetate copolymers, etc. are preferable because they have excellent transparency and low-temperature heat-sealability, especially those with a density of 0.9 + 0 to 0.
．． 960 and melting point (Tm: ASTM D 3417
) is preferably in the range of 100 to 165°C. In addition, melt flow rate of polyethylene fol) (MFR
3: ASTM D 12381K) is not particularly limited, but it is usually 0.01 to 30 E! from the viewpoint of moldability.
, / I Q min, even 0.1 to IOg/1
A range of 0 m1n is preferable.

The polypropylene tD) used in the present invention is a homopolymer of propylene or propylene and 10 mol% or less, preferably 5 mol% or less of other α-olefins, such as ethylene, 1-butene, 4-methyl -1-pentene, 1-hexene, 1-octene, 1-decene, 1-
It is a crystalline polymer mainly composed of propylene, such as a random or block copolymer with tetradecene etc.

Among these, homopolymers and random copolymers are preferable because they have excellent transparency, and especially have a low melting point (Tm: AS
A random copolymer with TM D3417) of 130 to 140"c is preferable because it has excellent heat sealing properties. Although MFR2 of the polypropylene film is not particularly limited, it is usually 0.5 to 30 g71 from the viewpoint of moldability.
0 min, even 0.5 to 10 g/10 m
A range of in is preferred.

In the laminated film of the present invention, the poly4-methyl-1-pentene (A) layer has the propylene polymer on at least one side of the poly4-methyl-1-pentene (A) layer.
α-olefin random copolymer (through the B1 layer, the polyethylene < C) or polypropylene (1) 1
It is a laminated film formed by laminating layers or mixture layers thereof.

The laminated film of the present invention can be produced by various known methods, for example, after forming a poly4-methyl-1-pentene (N film), forming a propylene/α-olefin random copolymer and polyethylene tc+ or polypropylene fDl or A method of extrusion coating a mixture thereof, in which a poly4-methyl-1-pentene (AI film) is formed in advance and then a separately formed polyethylene (Cl film or a polypropylene film or a film consisting of a mixture thereof) is coated with propylene/α-olefin random coating. A method of extrusion lamination using polymer (B), or a method of extrusion lamination using poly4-methyl-1-pentene (N1 propylene/a-olefin random copolymer (B) and polyethylene (C) or polypropylene+D+ or a mixture thereof at least Propylene/α-olefin random copolymer +
Examples include a method of coextrusion molding using E) as an intermediate layer, but coextrusion molding is preferred because it is simple to operate and can provide a laminated film with better interlayer adhesion. Coextrusion molding methods include a T-die method using a flat die and an inflation method using a circular die. The flat die may be of either a single manifold format using a black box or a multi-manifold format. As for the die used in the inflation method, any known die can be used.

The thickness of each layer of the laminated film of the present invention is not particularly limited, but usually the poly-4-methyl-1-pentene (A) layer is 10 to 100μ, preferably 10 to 50μ,
Usually propylene/α-olefin random copolymer (B
One layer is 5 to 50μ, preferably 10 to 60μ,
The thickness of the heat seal layer, such as polyethylene (0), is usually in the range of 10 to 100μ, preferably 10 to 50μ.

The laminated film of the present invention comprises poly4-methyl-1-pentene (Al layer/propylene/α-olefin random copolymer (layer)/polyethylene (01 layer or polypropylene (D) layer or a mixture layer thereof). As long as the Furthermore, polyvinyl alcohol, saponified ethylene/vinyl acetate copolymer, polyamide, polyester, paper, aluminum foil, etc. may be laminated.

Poly-4-methyl-1- constituting the laminated film of the present invention
Pentene (A) Jif, propylene/α-olefin random copolymer tB1 layer and polyethylene (Cl
) on any or all of the heat seal layers, such as
Weathering stabilizers, heat stabilizers, antistatic agents, antifogging agents, antiblocking agents, slip agents, lubricants, pigments, dyes, droplet agents,
Various compounding agents, such as a nucleating agent, which are usually added to polyolefin may be added to the extent that does not impair the purpose of the present invention. In order to further improve heat sealability, ethylene/α-olefin copolymers such as low-crystalline or amorphous ethylene/propylene copolymers, ethylene/1-butene copolymers, ethylene/vinyl acetate, etc. A copolymer or the like may also be added.

The laminated film of the present invention takes advantage of its transparency, heat resistance, stain resistance, and water repellency to produce various foods (e.g. vegetables, confectionery, etc.).
Suitable for packaging meat (meat), bread, and seafood.

EXAMPLES Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples in any way unless it goes beyond the gist thereof.

Example 1 Density: 0.835 g/cm and MF R5' 26
R710min 4-methyl-1-pentene/1-decene copolymer (hereinafter abbreviated as TPX-1), propylene content near 1.0 mol%, melting point: 110°C, MFR2 near, 0 g/10 min, boiling n-hebutane insoluble content: 20.5%, boiling methyl acetate soluble content: 20.5%, and M Engineering T
:0.9/l propylene/1-butene random copolymer (hereinafter abbreviated as PBR-1) and density 0.9 + 7
g/cm, MFR3: 6.5 g/ID mi
n and Tm: ID5°C high-pressure polyethylene (hereinafter b)
ppx-1) and PBR-1 as an intermediate layer using a 40 mmφ extruder (cylinder temperature 270°C), 11
0mmφ extruder (cylinder temperature 250℃) and 4Qm
After melting with an mφ extruder (cylinder temperature 250°C), extrusion from a spiral die for forming a three-layer blown film (guidance temperature 260°C), cooling with water, TPX-1:
20μ, PBR-1: 20μ and LDPK-1: 20μ
A coextruded three-layer film was obtained. Next, physical properties were evaluated by the following method.

Adhesive strength (g/15mm): Cut a 15mm wide test piece and crosshead speed 200.
It is expressed as the strength when peeled between each resin layer in mm/min.

Peel strength of heat-sealed part (g/45mm): LDPE film surfaces or PP film surfaces stacked 1
At a temperature of 20"C, 250°C and a pressure of 21q/3 for 1 second: Heat seal with a 10mm wide sealing bar and then let it cool. Cut a 15mm wide test piece from this and set it at a crosshead speed of 200 mm/min. It is shown by the strength when the heat-sealed part is peeled off.

The results are shown in Table 1.

Example 2 The same procedure as in Example 1 was carried out except that the three-layer film of Example 1 was replaced by a coextruded three-layer film in which each layer had a thickness of 50 μm. The results are shown in Table 1.

Example 6 Instead of IIDPK-1 used in Example 1, density s
0.91 g/c+++', MFR: 51z710m
Using a propylene/ethylene random copolymer (hereinafter abbreviated as pp-■) with 1n and Tm: 1AO°C, pp-
The same procedure as in Example 1 was carried out except that the cylinder temperature of the extruder No. 1 was set at 270''C. The results are shown in Table 1.

Comparative Example 1 In Example 1, TPX-
The same procedure as in Example 1 was carried out except that a two-layer film of No. 1 and LDPIC-1 was used. The results are shown in Table 1.

Claims (1)

[Claims] (1) At least one side of the poly-4-methyl-1-pentene film has a propylene content of 50 to 87 mol%.
and a polyethylene (0) or polypropylene (D) layer or the like through a propylene/α-olefin random copolymer (B) layer with a heat of crystal fusion of 801ou1θ/g based on thermal analysis using a differential scanning calorimeter. A laminated film characterized by laminating layers of a mixture of.