JPS6178805A - Extrusion-coatable poly(4-methyl-1-pentene) and extrusion coating of substrate therewith - Google Patents

Abstract

PURPOSE:The titled polymer which is excellent in high-speed extrusion coatability of a thin-film substrate and can give a laminate excellent in heat resistance, releasability, oil resistance and chemical resistance, having a specified melt flow rate, a specified MW distribution and a specified melt tension. CONSTITUTION:Poly(4-methyl-1-pentene) having a melt flow rate of 50-1,000g/10min, a MW distribution of 1.5-20 and a melt tension at 270 deg.C of 2X10<-4>-2.0g. Because this polymer has markedly improved high-speed extru sion coatability, it is possible to obtain an extrusion-coated material sufficiently excellent in mechanical properties merely by operating a usual extrusion coating apparatus at an increased speed of extrusion coating. Further, by blowing a gas against the both sides of a thin-film material in extrusion coating of a substrate with a melt of the poly(4-methyl-1-pentene) in the form of a thin film, the neck-in and waviness on the sides of the thin film can be improved and the extrusion coating can be performed more stably at a high speed.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention has excellent extrusion coating processability at high speeds on thin film substrates such as plastic films, cellophane, paper, and metal foils, and also provides a uniform coating layer. The present invention also relates to poly-4-methyl-1-pentene for extrusion coating and an extrusion coating method suitable for obtaining a laminate having excellent heat resistance, mold releasability, oil resistance, and chemical resistance.

[Conventional technology]

High-pressure polyethylene (HP-L) is used as a coating material for composite films processed by extrusion coating (extrusion coating).
DPE) is used in the largest amount as a sealant because of its good low-temperature heat-sealability and excellent high-speed coating processability. However, HP-LDPE cannot be used in applications requiring heat resistance because of its low melting point. Polypropylene (PP) is used as an alternative material to HP-LDPE in some fields that require heat resistance, but PP has processing disadvantages such as surging and large necking during extrusion processing. ing.

On the other hand, poly4-methyl-1-pentene is HP-LDPE
Among polyolefins such as PP and PP, it has the highest melting point and excellent heat resistance, so it is extruded and coated in parts and used for baking cartons, industrial coated paper, etc. However, poly-4-methyl-1, which is usually used for such purposes,
- Pentene has the drawback that when extrusion coating is formed at high speed, it causes a draw resonance phenomenon, resulting in uneven thickness and thinness, making it impossible to obtain a composite film with a uniform thickness, resulting in poor productivity. ing.

[Problem that the invention seeks to solve]

In view of this situation, the present inventor has developed a material that has excellent extrusion coating processability at high speeds, has a uniform ri layer, and has the inherent heat resistance, mold releasability, oil resistance, and resistance of poly-4-methyl-1-pentene. As a result of various studies to develop poly-4-methyl-1-pentene for extrusion coating processing, which is suitable for obtaining coatings with good mechanical properties without impairing chemical properties, we found that a specific melt flow rate and molecular weight distribution were obtained. It was found that poly-4-methyl-1-pentene having the above-described properties and melt tension had the above-mentioned properties, and the present invention was completed.

[Means for solving problems]

That is, the present invention has a melt flow rate (MFR) of 50
to 1000 g/10 m1n, molecular weight distribution (
poly(4-methyl) for extrusion coating, characterized in that the MWD) is in the range of 1.5 to 30 and the melt tension (MT) at 270°C is in the range of 2 x 10''4 to 2.0 g.
1-pentene and the poly-4-methyl-1-pentene are melted and then extruded from a die into a thin film to extrude and coat the base material at high speed, characterized by blowing gas onto both ends of the thin film. Poly 4 for extrusion coating, which is suitable for obtaining coatings with excellent extrusion coating processability, a uniform coating layer, and good heat resistance, mold release properties, oil resistance, chemical resistance, and mechanical properties.
-Methyl-1-pentene and its extrusion coating processing method.

[Effect]

The poly-4-methyl-1-pentene for extrusion coating of the present invention is a homopolymer of 4-methyl-1-pentene or
- Methyl-1-pentene and usually up to 15 mol%, preferably up to 9 mol% of other α-olefins, such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-tetradecene , a copolymer with an α-olefin having 2 to 20 carbon atoms such as 1-octadecene, MFR (load 5 kg, temperature 260°C) 50 to 1000 g/10 ml, preferably 100 to 300 g/10 ml, MWD is 1.5 to 20, preferably 2 to 10 and MT (270°C)
is 2×10 2.0 g, preferably 1×10′. It is a crystalline polyolefin in the Og range.

If the MTR is less than 50 g/10 m1n, a take-up resonance phenomenon will occur during extrusion coating under high speed, making it impossible to obtain a uniform coating material, while if it exceeds 1000 g/10 m1n, it will have a low viscosity when it comes out of the die. As a result, a drop-off phenomenon occurs and the film is not uniform.

If the MWD exceeds 20, the amount of low molecular weight components increases and bleed substances appear on the surface of the laminate coating layer, which is not practical. On the other hand, those with MWD lower than 1.5 have significantly poor moldability. If the MT is less than 2X1 (1"g, the neck-in will be large and it will be difficult to mold.
If the weight exceeds g, the web coming out of the die cannot be spread and high-speed molding cannot be performed.

The molecular weight distribution (MWD) in the present invention is defined as the difference between the weight average molecular weight (MW) and number average molecular weight (M n ) of poly4-methyl-1-pentene measured by gel permeation chromatography (GPC). Ratio (W/n)
This is the value expressed as .

Measurement of molecular weight distribution by GPC was carried out according to the following method. That is, using 0-dichlorobenzene as a solvent, 0.04 g of polymer per 100 parts by weight of solvent (
As a stabilizer, 0.05 g of 2,6-di-tert-butyl-p-cresol was added to 100 parts by weight of the polymer to form a solution, and then insoluble matter such as dust was removed through a 1 μm filter. After that, column temperature 13
Measurement was performed using a GPC measuring device at a flow rate of 1.0 ml/min at 5° C., and numerical ratios were calculated based on polystyrene.

MT in the present invention is a melt tension tester ■ type (
Toyo Seiki Seisakusho (required), nozzle shape: diameter 2.09
mmφ, length 8, 0mm, piston descending speed: 15m
m/min, extrusion temperature: 270°C, withdrawal speed: 45m/min,
Tension measurement position: Values measured under conditions of 500 mm below the nozzle.

The method for producing the poly-4-methyl-1-pentene for extrusion coating of the present invention is not particularly limited as long as it has the above characteristics. Specifically, for example, Japanese Patent Application No. 58-8
In the method for producing 4-methyl-1-pentene polymer in No. 0936, there is a method of direct polymerization using a large amount of hydrogen, a method in which a VFR of less than 10 g/10 m1n is prepolymerized, and then in the presence or absence of oxygen. A method of manufacturing by heating and melting at 260 to 390°C and thermal degradation due to shear stress, same < MFR less than 10 g/10 m1n, poly4-methyl-1-pentene too lX10 = to 5x per weight part Examples include a method of adding and mixing 10 parts by weight of a radical initiator such as an organic peroxide, heating and mixing at 250 to 360° C. in the presence or absence of a solvent, and thermally degrading the mixture.

The base material of the poly-4-methyl-1-pentene for extrusion coating of the present invention may be any polymer having film-forming properties, paper, metal foil such as aluminum foil, copper foil, cellophane, etc. be able to.

Examples of such polymers include high density polyethylene, medium and low density polyethylene, ethylene/vinyl acetate copolymer, ethylene/acrylic acid ester copolymer, ionomer, polypropylene, poly-1-butene, poly-
Olefin polymers such as 4-methyl-1-pentene, vinyl polymers such as polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylate, polyacrylonitrile, nylon 6, nylon 66, nylon 7, nylon 10, nylon 11 , nylon 12, nylon 610
, polyamides such as polymethaxylylene adipamide, polyesters such as polyethylene terephthalate, polyethylene terephthalate/isophthalate, and polybutylene terephthalate, polyvinyl alcohol, ethylene:vinyl alcohol copolymers, polycarbonates, and the like. These base materials can be appropriately selected depending on the purpose and the item to be packaged. For example, if the packaged item is a food that is easily corroded, use a resin with excellent transparency, rigidity, and gas permeation resistance such as polyamide, polyvinylidene chloride, ethylene/vinyl alcohol copolymer, polyvinyl alcohol, or polyester. is selected.

Base materials with excellent heat resistance such as paper, aluminum foil, and cellophane are selected for baking cartons, industrial release paper, etc. that take advantage of the heat resistance of the coating material poly-4-methyl-1-pentene. For confectionery, textile packaging, etc., polypropylene or the like with good transparency, rigidity, and resistance to water passage can be selected as the outer layer. Further, if the base material is a polymer, it may be uniaxially or biaxially stretched.

Poly 4-methyl-1 for extrusion coating of the present invention is applied to the base material.
- Pentene may be coated by extrusion directly on the substrate, or in order to increase the adhesion between the substrate and the composition, the pentene may be coated by a known method such as organic titanium, polyethylene, etc. Poly 4-methyl-1 for extrusion coating of the present invention may be applied after applying an anchor coating agent such as imine type or isocyanate type, and further underlaying adhesive polyolefin, high-pressure polyethylene, etc. - Pentene has significantly improved extrusion coating properties at high speeds compared to conventional poly-4-methyl-1-pentene, so simply increase the extrusion coating speed using regular extrusion coating equipment. However, when extruding the poly-4-methyl-1-pentene into a thin film from a die after melting it and extrusion coating it on a base material, A gas such as air or nitrogen gas is blown onto both ends of the object, preferably in the vicinity where the thin film-like material contacts the base material, preferably from the side where the thin film-like material does not contact the base material. When sprayed, neck-in and waviness at both ends of the thin film material are improved, and extrusion coating molding can be performed more stably at high speeds.

Specifically, as a method for blowing gas onto a thin film-like material, for example, a conduit such as a metal pipe such as an aluminum pipe, a steel pipe, or a thermoplastic resin pipe is placed downstream of the die, and the gas is blown from the conduit through the poly 4-
A method may be mentioned in which a film of methyl-1-pentene is extruded from a die and sprayed at any position between which it contacts the base material, preferably near the contact point where the thin film is coated on the base material. The pressure of the gas when spraying is determined as appropriate considering the thickness of the thin film to be coated, but it is usually 0.5 to 5k.
g/cnlG range. The aperture of the tip of the nozzle used for spraying is usually in the range of 11/1 to 50 mm, preferably 5 mm to 10 m. Also, the distance from the tip of the nozzle to the thin film is usually 2IllII+ to 1
00mm, preferably in the range of 5mm to 20III11. Furthermore, it is preferable to direct the tip of the nozzle from the inside of the thin film to the outside, since the blown gas expands the thin film and further increases the effect of narrowing the neck-in.

The extrusion temperature for extrusion coating the poly-4-methyl-1-pentene for extrusion coating of the present invention on a substrate is usually 250 to 370°C, preferably 290 to 340°C. Also, the extrusion coating speed (coating material take-off speed) is Loom/m
It can be carried out in the range of 150 to 500 m/1 II in or more. Poly-4-methyl- in extruded coatings
The film thickness of 1-pentene can be selected depending on the intended use of the coating material, but it is usually in the range of 5 to 50 microns, preferably 15 to 25 microns.

The poly-4-methyl-1-pentene for extrusion coating of the present invention includes weathering stabilizers, heat stabilizers, antistatic agents, antifogging agents,
Various additives such as anti-blocking agents, slip agents, lubricants, pigments, dyes, droplet agents, etc. which are usually added to polyolefins may be added to the extent that the purpose of the present invention is not impaired.

〔Effect of the invention〕

The poly-4-methyl-1-pentene for extrusion coating of the present invention is processed at a higher speed than conventional poly-4-methyl-1-pentene, for example, the maximum extrusion coating speed that does not cause uneven thickness or thinness is about 9 Qm/min. However, even if conventional processing equipment is used as is, it can be processed at speeds up to about 180 m/min, and by blowing gas on both ends of the extruded thin film, it can be processed at speeds of about 200 m/min or more without causing unevenness. , poly-4-methyl- has excellent productivity and coating material performance.
1-Pentene has the inherent characteristics of heat resistance, mold releasability, oil resistance, chemical resistance, etc., and also has good mechanical properties, so it is especially useful for paper, aluminum foil, two-wheel stretched polypropylene film, biaxially stretched polyethylene terephthalate film,
It can be coated on a nonwoven fabric or the like and suitably used for cooking containers (such as baking cartons), retort food containers, heat-resistant sterilization packaging containers, drug packaging containers, and the like.

〔Example〕

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 the gist of the invention is exceeded.

Example 1.2 MFR: 0.4g/10ml poly-4-methyl-1-pentene powder (hereinafter abbreviated as PMP-1')
100 parts by weight of heat stabilizer (trade name Irganox 1)
010: Musashino Geigy) and calcium stearate were added in 0.005 and 0.001 parts by weight, respectively,
After mixing with Henschel mixer, 65mmφ single screw extrusion 1L
1 (molding temperature 350° C.) to obtain sample-■.

The MFR of the obtained sample -■ is 150 g / 10 m1
n, MWD was 6.0 and MT was 0.3 g. Next, the tip of the die is provided with an outer diameter of 10 mm as shown in Figure 1.
mmφ, 90 m in which conduits 1 and 2 with a diameter of 3 mmφ at the tip of the nozzle were installed at a position 10 mm above the surface of the coating material (thin film).
Sample-■ was melt-extruded from an mφ extrusion laminate molding machine (molding temperature: 330°C) and coated onto a 350μ-thick white paperboard so that the coating thickness was 20μ and 10μ, respectively.
When extrusion coating was performed by blowing 3 kg/cxaG of air from the conduits 1 and 2 onto the thin film on the line where the extruded thin film was in contact with the white paperboard, resulting in extrusion coating with a thickness of 20μ. The neck in is 10mm (piece 1!J)
Sample-1 (7) Ear shaking and take-up resonance phenomenon did not occur up to an extrusion coating speed of 260 m/min, and when the thickness was 10μ, the neck-in was 15 mm (one side), and the extrusion coating speed was 23
No problem occurred up to 0 m/min, and good laminates with no thickness or thinness unevenness were obtained in all cases. Next, the number of pinholes in the laminate was measured by the following method.

Number of pinholes (number/d): Sample of laminate - A methyl ethyl ketone solution containing 2% by weight of pigment (ulmarine blue) was applied from the side of the coated laminate, and after 20 hours, the coated surface was washed with methyl ethyl ketone. , counting the blue spots on the white paperboard.

The results are shown in Table 1.

Example 3 Instead of PMP-I used in the example work, MFR was 6g/
The MFR obtained by thermally degrading 10 m1n of poly-4-methyl-1-pentene powder was 250 g/10 m1n.

The same procedure as in Example 1 was carried out except that Sample-■ having an MWD of 5.5 and an MT of 0.15 g was used. The results are shown in Table 1.

Example 4 Instead of PMP-I used in Example 1, MFR was 6 g/
The MFR obtained by thermally degrading 10mln of poly-4-methyl-1-pentene powder is 300g/10min, MW
The same procedure as in Example 1 was carried out except that Sample-■ having D of 5.1 and MT of 0.1 g was used. The results are shown in Table 1.

Example 5 The same procedure as in Example 1 was carried out except that the blowing of air from the conduit was stopped. The results are shown in Table 1.

Comparative Example 1 Instead of PMP-1 used in Example 1, MFR was 6g
MFR obtained by thermally degrading poly4-methyl-1-pentene of /10mln is 20g/10IIIin, MWD
The same procedure as in Example 1 was carried out except that Sample-■ having a MT of 7.3 and a MT of 2.5 g was used. The results are shown in Table 1.

Comparative Example 2 Instead of PMP-I used in Example 1, MFR was 6g
MFR obtained by thermally degrading poly-4-methyl-1-pentene powder of /10 m1n was 20 g/10 m1n.

The same procedure as in Example 1 was carried out except that Sample-■ having an MWD of 6.9 and an MT of 2.8 g was used. The results are shown in Table 1.

Comparative Example 3 Instead of PMP-1 used in Example 1, MFR was 0.
The MFR obtained by thermally degrading poly-4-methyl-1-pentene powder of 5 g/10 m1n is 20 g/10 m
1n.

The same procedure as in Example 1 was carried out except that Sample 3 having an MWD of 6.5 and an MT of 3.0 g was used. The results are shown in Table 1.

[Brief explanation of drawings]

The figure represents a portion of an extrusion laminating machine equipped with a conduit for use in the method of the invention.

Claims (2)

[Claims] (1) Melt flow rate is 50 to 1000g/10min, molecular weight distribution is 1.5 to 2
Poly4-methyl-1-pentene for extrusion coating, characterized in that its melt tension at 0 and 270° C. is in the range of 2×10^-^4 to 2.0 g. (2) Melt flow rate is 50 to 1000g/10min, molecular weight distribution is 1.5 to 2
When poly-4-methyl-1-pentene having a melt tension in the range of 2 x 10^-^4 to 2.0 g at 0 and 270°C is melted and extruded into a thin film from a die to extrusion coat it on a substrate, a thin film is formed. An extrusion coating method characterized by blowing gas onto both ends of a shaped article.