JPH072802B2 - Poly 4-methyl-1-pentene for extrusion coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is excellent in extrusion coating processability at a high speed on a thin film substrate such as plastic film, cellophane, paper, and metal foil, and has a uniform coating layer. The present invention also relates to poly4-methyl-1-pentene for extrusion coating, which is suitable for obtaining a laminate having excellent heat resistance, releasability, oil resistance, and chemical resistance.

[Conventional technology]

As a coating material for a composite film by extrusion coating (high pressure extrusion coating), high-pressure polyethylene (HP-LDPE) is used as a sealant in the largest amount because it has good low-temperature heat sealability and excellent high-speed coating processability. However, since HP-LDPE has a low melting point, it cannot be used for applications that require heat resistance. Polypropylene (PP) is used as an alternative material to HP-LDPE in some fields where heat resistance is required, but PP tends to surging during extrusion processing, and has a drawback in processing when large necking is used. is doing.

On the other hand, poly-4-methyl-1-pentene has the highest melting point and excellent heat resistance among the polyolefins such as HP-LDPE and PP. It is used for paper, etc. However, the poly-4-methyl-1-pentene that is usually used for such applications causes a take-up resonance phenomenon (draw resonance) when extrusion coating is performed at a high speed and causes unevenness of thickness, so that a composite film having a uniform thickness is formed. It has the drawback that it cannot be obtained and the productivity is poor.

[Problems to be solved by the invention]

In view of such circumstances, the present inventor has found that the extrusion coating processability at high speed is excellent, the coating layer is uniform, and the heat resistance, mold releasability, oil resistance, and chemical resistance inherent to poly-4-methyl-1-pentene are high. As a result of various studies to develop a poly-4-methyl-1-pentene for extrusion coating suitable for obtaining a coating having good mechanical properties without impairing the properties, a specific melt flow rate, molecular weight distribution and Poly 4-methyl-having melt tension
It was found that 1-pentene had the above-mentioned performance, 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 min and a molecular weight distribution (MWD) of 1.5 to 30 and 2.
The melt tension (MT) at 70 ° C is in the range of 2 × 10 ^-4 to 2.0 g, and it has excellent workability for extrusion coating at high speed, and the coating layer is uniform and has heat resistance and releasability. The present invention provides a poly-4-methyl-1-pentene for extrusion coating, which is suitable for obtaining a coating having good oil resistance, chemical resistance and mechanical properties.

[Action]

The poly (4-methyl-1-pentene) for extrusion coating of the present invention is a 4-methyl-1-pentene homopolymer or 4
-Methyl-1-pentene and usually not more than 15 mol%, preferably not more than 9 mol% of other α-olefins such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-tetradecene. , 1-octadecene and other C2-C20 α-olefin copolymers, MFR (load 5kg, temperature 260 ℃) 50-1000g / 10mi
n, preferably 100 to 300 g / 10 min, MWD 1.5 to 2
0, preferably 2 to 10 and MT (270 ° C) in the range of 2 x 10 ^-4 to 2.0 g, preferably 1 x 10 ^-3 to 1.0 g of crystalline polyolefin.

If the MFR is less than 50g / 10min, a take-up resonance phenomenon occurs during extrusion coating at high speed, and a uniform coating material cannot be obtained.
If it exceeds 1000 g / 10 min, it will have a low viscosity when it comes out of the die, causing the phenomenon of flapping and not forming a uniform film.

If the MWD exceeds 20, the amount of low-molecular weight components increases, and the bleeding material appears on the surface after laminating, which is not preferable in practice. On the other hand, when the MWD is lower than 1.5, the moldability is remarkably poor. If the MT is less than 2 × 10 ^-4 g, the net quince becomes large and it becomes difficult to mold. On the other hand, if the MT exceeds 2.0 g, the web from the die cannot be spread and high speed molding cannot be performed.

The molecular weight distribution (MWD) in the present invention is a weight average molecular weight of poly-4-methyl-1-pentene (measured by gel permeation chromatography (GPC) (
It is a value represented by the ratio (w / n) between w) and the number average molecular weight (n).

The measurement of the molecular weight distribution by GPC was performed according to the following method. That is, o-dichlorobenzene was used as the solvent, and 0.04 g of the polymer (2,6-ditert-butyl-p-cresol as the stabilizer was added to 100 parts by weight of the solvent).
After adding 0.05 g to 1 part by weight to form a solution, 1
Remove insoluble matter such as dust through a μ filter.
Then, set the column temperature at 135 ℃ and the flow rate at 1.0 ml / min, and run the GPC.
The measurement was performed using a measuring device, and the numerical ratio was converted based on polystyrene.

As the MT in the present invention, a melt tension tester II type (manufactured by Toyo Seiki Seisakusho) is used, and the nozzle shape: diameter 2.09 mmφ,
Length 8.0 mm, piston descending speed: 15 mm / min, extrusion temperature: 270
C., take-up speed: 45 m / min, tension measuring position: value measured under the condition of 500 mm below the nozzle.

The production method of 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. 58-80936
In the method for producing a 4-methyl-1-pentene polymer described in No. 3, a method of directly polymerizing by using a large amount of hydrogen,
A method of preliminarily polymerizing one having an MFR of less than 10 g / 10 min, and then heat-melting it at 260 to 390 ° C. in the presence or absence of oxygen and thermally degrading it to shear stress, similarly, MFR is 10 g / 1
To less than 0 min, 1 × 10 ⁻⁴ to 5 × 10 ⁻² parts by weight of a radical initiator such as an organic peroxide is added and mixed per 100 parts by weight of poly-4-methyl-1-pentene, and in the presence of a solvent, Alternatively, it is possible to exemplify a method of heat-degrading by heating and mixing at 250 to 360 ° C. in the absence.

When an extrusion coating material is produced by using the extrusion coating poly-4-methyl-1-pentene of the present invention, as a base material of the extrusion coating material, any polymer or paper having film-type performance, aluminum foil, Metal foil such as copper foil, cellophane, etc. can be used. As such a polymer,
For example, high density polyethylene, medium and low density polyethylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid ester copolymer, ionomer, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, etc. Vinyl polymers such as olefin polymers, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylate, polyacrylonitrile, nylon 6, nylon 66, nylon 7, nylon 10, nylon 11, nylon 12, nylon 610, polymethacryl Examples thereof include polyamides such as silylene adipamide, polyesters such as polyethylene terephthalate, polyethylene terephthalate / isophthalate and polybutylene terephthalate, polyvinyl alcohol, ethylene / vinyl alcohol copolymers, polycarbonates and the like. . These bases are for the purpose,
It can be appropriately selected depending on the object to be packaged. For example, when the food to be packaged is easily corroded, a resin having excellent transparency, rigidity and gas permeation resistance such as polyamide, polyvinylidene chloride, ethylene / vinyl alcohol copolymer, polyvinyl alcohol and polyester can be used. To be selected.
A base material having excellent heat resistance such as paper, aluminum foil, cellophane, etc. is selected for a baking carton, an industrial release paper or the like, which takes advantage of the heat resistance of poly-4-methyl-1-pentene as a coating material. For confectionery, textile packaging, etc., transparency,
Polypropylene or the like having good rigidity and water permeation resistance can be selected as the outer layer. If the substrate is a polymer, it may be uniaxially or biaxially stretched.

Poly (4-methyl-1) for extrusion coating according to the present invention on the substrate
In order to extrusion-coat the pentene, the substrate may be directly extrusion-coated, or in order to enhance the adhesion between the substrate and the composition, the substrate may be subjected to a known method such as organotitanium-based polyethylene. After applying an anchor coating agent such as an imine type or an isocyanate type, an adhesive polyolefin, a high-pressure polyethylene or the like may be further undercoated and then extrusion coated.

The extrusion-coating processing poly-4-methyl-1-pentene of the present invention has a significantly improved extrusion-coating property under high speed as compared with the conventional poly-4-methyl-1-pentene, so that the usual extrusion-coating is performed. Although it is possible to obtain an extruded coating material having sufficiently excellent mechanical properties simply by increasing the extrusion coating speed using a processing apparatus, the poly-4-methyl-1-pentene is melted to form a thin film from a die. During extrusion and extrusion coating on the base material, a gas is blown to both ends of the thin film material, preferably both ends of the thin film material in the vicinity of the contact of the thin film material with the base material, preferably the thin film material is applied to the base material. By blowing a gas such as air or nitrogen gas from the non-contact side, the ears of both ends of the neckline and the thin film-like material are improved, and a stable extruded coating material can be stably formed at a high speed.

As a method of blowing a gas to the thin film, for example, a metal pipe such as an aluminum pipe or a copper pipe, a conduit such as a thermoplastic resin pipe is arranged downstream of the die, and the gas is supplied from the pipe to a poly 4-
Examples include a method in which a thin film of methyl-1-pentene is extruded from a die and sprayed at any position while contacting the substrate, preferably in the vicinity of the contact point where the thin film is coated on the substrate. The pressure of the gas at the time of spraying is appropriately determined in consideration of the thickness of the thin film material to be coated, but normally 0.5 to 5 kg / cm ² G
Is the range. The diameter of the tip of the nozzle to be blown is usually in the range of 1 mm ² to 50 mm ² , preferably 5 mm ² to 10 mm ² . The distance from the tip of the nozzle to the thin film is usually 2 mm to 100 mm, preferably 5 mm to 20 mm. Furthermore, it is preferable to direct the tip of the spraying nozzle from the inside to the outside of the thin film-like material, because the thin film-like material is expanded by the blown gas and the effect of narrowing the neck-in is further enhanced.

The extrusion temperature for extrusion-coating a substrate with the extrusion-coated poly-4-methyl-1-pentene of the present invention is usually 250 to 370.
C., preferably 290 to 340.degree. C. The extrusion coating speed (coating material take-up speed) is 100 m / min or more, and even 150
To 500 m / min. The film thickness of poly-4-methyl-1-pentene in the extrusion coating material can be variously selected depending on the use of the coating material, but is usually in the range of 5 to 50 µ, preferably 15 to 25 µ.

The extrusion coating processing poly-4-methyl-1-pentene of the present invention includes a weather resistance stabilizer, a heat resistance stabilizer, an antistatic agent, an antifogging agent,
Anti-blocking agents, slip agents, lubricants, pigments, dyes, dropping agents and the like may be blended with various compounding agents used in addition to the usual polyolefin within the range not impairing the object of the present invention. .

〔The invention's effect〕

The poly (4-methyl-1-pentene) for extrusion coating of the present invention is at a higher speed than the conventional poly (4-methyl-1-pentene), for example, the extrusion coating speed which does not cause unevenness in thickness is about 90 m / min at the maximum. Even if the conventional processing equipment is used as it is, up to about 180 m / min, and about 200 m / min by extrusion coating while blowing gas on both ends of the extruded thin film material.
Even with the above, without producing unevenness in thickness, it has excellent productivity, and the performance of the coating material has heat resistance, mold release property, oil resistance, chemical resistance, etc. which are the original characteristics of poly-4-methyl-1-pentene. As it has good mechanical properties, it can be coated on paper, aluminum foil, biaxially oriented polypropylene film, biaxially oriented polyethylene terephthalate film, non-woven fabric, etc., and used for cooking containers (baking cartons, etc.), retort food containers, heat resistance, etc. It can be suitably used for a sterilization packaging container, a medicine packaging container, and the like.

〔Example〕

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.

Example 1,2 MFR: 0.4 g / 10 min of poly-4-methyl-1-pentene powder (hereinafter abbreviated as PMP-I) 100 parts by weight of heat-resistant stabilizer (trade name Irganox 1010: manufactured by Musashino Geigy) and calcium stearate. Add 0.005 and 0.001 parts by weight respectively,
After mixing with a Henschel mixer, it was thermoformed with a 65 mmφ single screw extruder (molding temperature 350 ° C.) to obtain Sample-I. The obtained sample-I had MFR of 150 g / 10 min, MWD of 6.0 and MT of 0.3 g. Then, attach the outer diameter 10
Sample-I is melt extruded from a 90 mmφ extrusion laminating machine (molding temperature: 330 ° C) in which conduits 1 and 2 with a diameter of mmφ and a diameter of 3 mmφ at the tip of the nozzle are installed at a position of 10 mm on the surface of the coating material (thin film material) Each coating thickness is 20μ on 350μ white paperboard
And 10 μ on the line where the extruded thin film of Sample-I touches the white paperboard from the conduits 1 and 2 to 3 kg / cm ² G
As a result of performing extrusion coating while blowing the above air on the thin film material, when the extrusion coating is 20μ thick, the net quin is 10mm.
(One side), swaying of sample-I and take-up resonance phenomenon do not occur up to an extrusion coating speed of 260 m / min, and when the thickness is 10 μ, the net quin is 15 mm (one side), and up to an extrusion coating speed of 230 m / min. Good laminates were obtained which did not cause any problems and had no uneven thickness. Next, the number of pinholes in the laminate was measured by the following method.

Number of pinholes (pieces / m ² ): Coating of Sample-I of the laminate: From the laminate side, a methyl ethyl ketone solution containing 2% by weight of pigment (ultraviolet) was applied, and after 20 hours, the applied surface was washed with methyl ethyl ketone. Later, count the blue spots on the white paperboard.

The results are shown in Table 1.

Example 3 Instead of PMP-I used in Example 1, MFR obtained by thermally degrading poly-4-methyl-1-pentene powder having MFR of 6 g / 10 min.
Was 250 g / 10 min, MWD was 5.5 and MT was 0.15 g, and the same procedure as in Example 1 was carried out. The results are shown in Table 1.

Example 4 MFR obtained by thermally degrading poly-4-methyl-1-pentene powder having an MFR of 6 g / 10 min instead of PMP-I used in Example 1.
Was 300 g / 10 min, MWD was 5.1 and MT was 0.1 g. The results are shown in Table 1.

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

Comparative Example 1 Instead of PMP-I used in Example 1, MFR obtained by thermally degrading poly-4-methyl-1-pentene having an MFR of 6 g / 10 min was 2
Example 1 was repeated except that Sample-IV having 0 g / 10 min, MWD of 7.3 and 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, MF obtained by thermally degrading poly-4-methyl-1-pentene powder having MFR of 6 g / 10 min.
The same procedure as in Example 1 was carried out except that Sample-V having R of 20 g / 10 min, MWD of 6.9 and MT of 2.8 g was used. The results are shown in Table 1.

Comparative Example 3 Instead of PMP-I used in Example 1, MFR was 0.5 g / 10 min.
Of poly-4-methyl-1-pentene powder obtained by thermal degradation
Example 1 was repeated except that the sample VI having MFR of 20 g / 10 min, MWD of 6.5 and MT of 3.0 g was used. The results are shown in Table 1.

[Brief description of drawings]

The figure represents a portion of an extrusion laminating machine equipped with a conduit for use in producing extrusion coatings using the extrusion coating poly 4-methyl-1-pentene of the present invention.

Claims (1)

[Claims] 1. A melt flow rate of 50 to 1000 g / 10 mi
n, a molecular weight distribution of 1.5 to 20 and a melt tension at 270 ° C. in the range of 2 × 10 ^-4 to 2.0 g, poly (4-methyl-1-pentene) for extrusion processing.