JPH1060189A - Polyethylene resin composition for resin-coated paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition which has a high moldability, smokes little is processing and can give resin-coated paper having a high moisture resistance and a high heat resistance by mixing a specified high-density polyethylene resin with specified high-pressure process low-density polyethylene resins. SOLUTION: This composition comprises 30-70 pts.wt. high-density polyethylene resin (A) having a density of 0.950g/cm<2> or above, a melt flow rate(MFR) of 5.0-45g/10min and a total amount of chloroform-extractible 18C and 20C components of 500ppm or below, 10-60 pts.wt. high-pressure process low-density polyethylene resin (B) having a density of 0.930 or below and an MFR of 2-20 and satisfying the relationship represented by formula I (wherein MFR is the melt flow rate, and MT is the melt tension) and 10-40 pts.wt. high-pressure process-low-density polyethylene resin (C) having a density of 0.930 or below and an MFR of 2-8 and satisfying the relationship represented by formula II (wherein MFR is the melt flow rate, and MT is the melt tension), has a density of 0.935 or above and a melt tension of 1.2-1.5 after being melt-kneaded and has a content of the fatty acid metal salt of 500ppm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyethylene resin composition for coating one or both sides of a paper substrate with a resin layer by extrusion lamination.
Specifically, the resin layer has excellent moldability, the moisture resistance and heat resistance of the resin layer are good, and the adhesiveness between the paper substrate and the resin layer is excellent, especially during high-speed processing, and the amount of smoke generated during processing The present invention relates to a polyethylene resin composition for a resin-coated paper, which has a characteristic of having a very small amount of smoke and is low in smoke emission and suitable for high-speed molding.

[0002]

2. Description of the Related Art Paper substrates such as paper, paperboard, and cellophane
It is common practice to coat one or both sides of a paper substrate with a resin that can be extruded and laminated, and use these materials for food packaging materials, moisture-proof paper, release paper, photographic printing paper, etc. Coated paper is well known.

[0003] In these resin-coated papers, particularly when moisture resistance, heat resistance, and smoothness of the resin film surface are required,
It is well known that high-density polyethylene having a high melting point is often used for the resin layer, and that the higher the density, the better the moisture resistance and heat resistance. However, increasing the density of the resin causes problems such as fluctuations in the thickness of the resin film, breakage of the film, excessive neck-in, and poor adhesion to the paper base material in laminating when manufacturing resin-coated paper. In particular, when the adhesiveness to the paper substrate is insufficient, not only does the problem of peeling of the product occur in the secondary processing, but also the moisture resistance and the heat resistance are adversely affected. Among these problems, there is a method of improving workability such as neck-in and drawdown by coping with high-density low-density polyethylene. For example, JP-A-6-190983 discloses that In the mixture with low-density polyethylene, if the physical properties of the resin are in a specific range, various MFRs, densities, molecular weights and molecular weight distributions can be used. Melt mixing with polyethylene alone is inferior in high-speed processability, and in particular, as the processing speed increases, the adhesion to the paper base material decreases, and it is difficult to obtain a product of stable quality over a wide range.

[0004] In particular, in order to increase productivity, products are usually produced at a running speed of 150 m / min or more even in laminating using a paper base material. In particular, there is a case where the adhesion between the resin and the paper base material is insufficient, so that a remarkable deterioration in quality is noticed.

Further, it is effective to raise the processing temperature of the laminate and increase the degree of oxidation of the resin film in order to obtain the adhesion to the paper substrate, but at an appropriate temperature for obtaining an appropriate degree of oxidation. At a certain temperature of 320 ° C. or higher, a gel-like defect may appear in the resin film due to a change in the flow of the molten resin due to long-term continuous operation, a radical chain reaction of polyethylene, or the like. In particular, in a resin produced using a metal catalyst, such as high-density polyethylene, the catalyst residue promotes thermal oxidation. More likely to occur. In the case of food packaging materials, photographic printing papers and the like, this gel not only impairs the appearance as projections on the surface of the coated paper, but also causes peeling due to poor printing or insufficient adhesion in some cases.

[0006] In the case of release paper, in the step of applying a silicone release agent on the resin layer, a non-uniform applied portion may be generated, which may cause poor quality.

Further, in the high-temperature, high-speed processing as described above, low-molecular-weight components in the resin emit smoke and fill around the processing machine, which not only has an adverse effect on the environment, but also in long-term operation, Oil and smoke components adhere to the surface of the chill roll, causing the product to be more easily peeled off the roll.
Production itself may be difficult.

As described above, the high-density type polyethylene resin composition for resin-coated paper has excellent high-speed moldability while maintaining the moisture resistance and heat resistance of the product, and has good compatibility with paper base. It has been practically difficult to provide a polyethylene resin composition that provides sufficient adhesiveness and that can operate stably for a long period of time by suppressing smoking during processing.

[0009]

DISCLOSURE OF THE INVENTION The present invention provides a polyethylene-based resin-coated paper that has a very good processability of forming a resin layer and suppresses the amount of smoke generated during processing.
Stable production over a long period of time is possible, sufficient adhesion with the paper substrate is obtained even at high speed processing, high moisture resistance,
It is an object of the present invention to provide a polyethylene resin for producing a resin-coated paper having heat resistance.

[0010]

Means for Solving the Problems The present inventors have proposed a resin-coated paper having a polyethylene-based resin as a resin layer, as a resin, a two-component high-pressure low-density polyethylene resin having specific viscoelastic properties. And a mixture with a high-density polyethylene resin having specific physical properties have been found to be suitable for the purpose of solving the problems, and the present invention has been accomplished based on this finding. That is, the present invention has a density of 0.
950 g / cm ³ or more, melt flow rate is 5.0
30 to 70 parts by weight of a high-density polyethylene resin having a total value of 500 ppm or less when extracted with chloroform at a density of 0.930 g / cm ³ or less. Rate 2 ~
20 g / 10 min, 10 to 60 parts by weight of a high-pressure low-density polyethylene resin satisfying the following formula (1), the density being 0.930 g / cm ³ or less and the melt flow rate being 0 0.2 to 8 g / 10 minutes, the relationship between the melt flow rate and the melt elasticity index is 10 to 40 parts by weight of a high-pressure low-density polyethylene resin satisfying the following formula (2). 0.935
g / cm ³ or more and melt elasticity index is 1.2 g or more and 15 g
Hereinafter, the present invention relates to a polyethylene resin composition for resin-coated paper in which the amount of the fatty acid metal salt to be blended is 500 ppm or less.

MT ≦ −0.4 log (MFR) +4.0 (1) MT ≧ −0.5 log (MFR) +4.2 (2) Here, MT and (2) in the equations (1) and (2) MFR
Represents a melt elasticity index and a melt flow rate (hereinafter, referred to as MFR), respectively.

The melt elasticity index is defined as the value obtained when a strand of a molten resin extruded under the same temperature and load as in the MFR measurement at a speed of 8 m / min in a room at a room temperature of 23 ° C. and a humidity of 50%. This refers to the pulling tension.

Hereinafter, the present invention will be described in detail.

The high-density polyethylene resin used in the polyethylene composition for resin-coated paper of the present invention has a density of 0.950 g / cm ³ or more and an MFR of 5.
0 to 45 g / 10 min, and the total value of each component having 18 and 20 carbon atoms when extracted with chloroform is 500
ppm or less. Examples of the high-density polyethylene resin having the above-mentioned physical properties include a homopolymer of ethylene, a copolymer with an α-olefin containing ethylene as a main component, or a mixture thereof.

The high-density polyethylene resin used in the present invention needs to have a density of 0.950 g / cm ³ or more and an MFR of 5.0 to 45 g / 10 minutes. When the density is less than 0.950 g / cm ^3, poor cutting of the resin is likely to occur at the time of cutting the product, which may result in a defect that is inferior in secondary workability, and also deteriorates the moisture resistance and heat resistance. When the MFR is less than 5.0 g / 10 minutes, the secondary workability is deteriorated as described above, and the high-speed workability is also adversely affected. When the MFR exceeds 45 g / 10 minutes, high-speed workability and workability such as neck-in are inferior, which is not preferable.

Further, in order to reduce the amount of smoke generated during processing, it is necessary that the total value of each component having 18 and 20 carbon atoms extracted with chloroform in high-density polyethylene be 500 ppm or less. If the value exceeds 500 ppm, the amount of smoke generated during laminating processing becomes extremely large, and the adhesion of the smoke emitting component to the cooling roll deteriorates the releasability of the product from the cooling roll, or the smoke emitting component contains a molten resin film. Long-term continuous stable operation becomes impossible, such as the occurrence of defects due to the drop of oil-smoke components formed on the surface of the slit die or the smoke duct attached to the top of the slit die for sucking smoke components attached to the top of the slit die. There are cases.
If the releasability from the cooling roll is deteriorated, the paper base and the polyethylene resin film may be separated, and the deterioration of the product quality, such as the decrease in moisture resistance and heat resistance and the poor appearance of the product, is inevitable. In addition, high-speed processing becomes impossible, which adversely affects productivity. Further, the occurrence of defects due to the drop of the oil and smoke component onto the product impairs the value of the product in any of food packaging materials based on paper, release paper, moisture-proof paper, photographic printing paper, and the like.

The components having 18 and 20 carbon atoms were quantified as follows.

That is, 50 g of resin pellets and 100 cc of chlorophorom were placed in a sealable 250 cc stainless steel container, the container was sealed, and the mixture was shake-extracted for 1 hour in a hot bath at 80 ° C., and cooled to room temperature. Quantification was performed by gas chromatography (hereinafter referred to as GC). G
For quantification by C, use GC-9A manufactured by Shimadzu Corporation.
200 ° C. with a 3 m column using OV-17 as a packing material
Under certain conditions, the injection section temperature was 250 ° C., nitrogen was used as the carrier gas, and the flow rate was 40 ml / min.
The detector was performed using FID.

The qualitative analysis of each component was carried out under the same conditions using standard samples of octadecane (18 carbon atoms) and eicosane (20 carbon atoms), and based on the retention time.

In the present invention, the sum of the components having 18 and 20 carbon atoms is used as a representative of the smoke-emitting component.
C. to 340.degree. C., which is due to a strong correlation with the amount of smoke generated during processing.

The high-density polyethylene resin to be used may be a mixture of separately produced resins or a mixture of two or more components produced by multi-stage polymerization, as long as all the above requirements are satisfied. Can also be used. When two or more high-density polyethylenes are used, the mixing ratio can be freely selected.

On the other hand, the high-pressure low-density polyethylene used for the resin layer requires at least two components, and one of the components (hereinafter sometimes referred to as a low melt index resin) has a density of at least two components. 0.930 g / cm ³ or less, MF
R is 2 to 20 g / 10 min, preferably 2 to 15 g / 10
And the relationship between the melt flow rate and the melt elasticity index satisfies the following expression (1). The other component (hereinafter, sometimes referred to as a high melt index resin) has a density of 0.930 g / cm ³ or less and an MFR of 0.2 to 8 g / 10 min, preferably 0.3 to 5 g. / 10
And the relationship between the melt flow rate and the melt elasticity index must satisfy the following expression (2).

MT ≦ −0.4 log (MFR) +4.0 (1) MT ≧ −0.5 log (MFR) +4.2 (2) where MT in the equations (1) and (2) is Melt elastic resin, MFR represents melt flow rate.

When the density of at least one of the two or more high-pressure low-density polyethylene resins exceeds 0.930 g / cm ³ , the melt elasticity index becomes too low, so that high-speed processability is not obtained. Becomes worse, the neck-in becomes very large, and the productivity decreases.

In the present invention, the purpose of using a high-pressure low-density polyethylene resin having at least two components is that the present invention is based only on a mixture of a resin having a low melt elasticity index and a resin having a high melt elasticity index. 250m in resin used for high-density type laminate molding such as
/ Min.

The melt elasticity index depends not only on the MFR of the resin but also on the density, the number of long-chain branches, and the molecular weight distribution. In general, the lower the MFR and the lower the density,
It increases as the number of long-chain branches increases or as the molecular weight distribution increases. Therefore, even if the resins show the same MFR,
Control of the melt elasticity index is possible with other resin designs.

In the case of a mixture of a high-density polyethylene resin and a high-pressure low-density polyethylene resin, which is generally used for producing a high-density type resin for lamination molding, complete compatibility of the resin cannot be obtained. Therefore, it is considered that a problem such as a variation in the thickness of the resin film or poor adhesion at the time of high-speed processing is expressed. In order to solve this problem, a resin having a low melt elasticity index is mixed as in the present invention. It is effective. In general, high-density polyethylene has a very low melt elasticity index, and it is difficult to mix completely with high-pressure low-density polyethylene having a high melt elasticity index. It is considered that since the mixing improves the compatibility, uniform mixing becomes possible, and high-speed processability and a sufficient adhesive force with the paper base material during high-speed processing are obtained. Therefore, when only a resin having a low melt elasticity index is blended, good results are obtained in high-speed processability, but the neck-in becomes extremely large, which adversely affects productivity. Also, when using only a resin having a high melt elasticity index, the neck-in shows a good result,
Due to poor compatibility, 200 m
Per minute may not be possible, which also adversely affects the adhesion to the paper substrate.

The low melt elasticity index resin has an MFR of 2 g / 1.
It is necessary to be in the range of 0 to 20 g / 10 minutes, and when the MFR is less than 2 g / 10 minutes, the effect of improving compatibility is diminished, so that high-speed workability may be poor. On the other hand, if the MFR exceeds 20 g / 10 minutes, the content of low molecular weight components increases, and it is not possible to suppress smoke during processing. The high melt elasticity index resin requires that the MFR be in the range of 0.2 g / 10 min to 8 g / 10 min. Mixing becomes difficult,
A gel may be generated in the resin film. When the MFR exceeds 8 g / 10 minutes, the neck-in becomes large,
In some cases, productivity may decrease.

The physical properties of the above components after melt mixing are as follows: the density is 0.935 g / cm ³ or more, the melt elasticity index is 1.2 g or more and 15 g or less, preferably 1.4 g or more and 10 g or less; Is required to be 500 ppm or less.

The polyethylene for resin-coated paper in the present invention
The density of the composition is 0.935 g / cm ^ThreeIf less than,
Poor secondary processing properties such as poor cutting may be observed.
Product properties such as moisture resistance and heat resistance
You. When the melt elasticity index is less than 1.2 g,
No improvement effect of the inn was recognized, and the drawdown property deteriorated.
As a result, productivity is greatly reduced. Melt index 15g
Above the neck-in shows very good results
However, when the resin film is processed, the ears are cut off.
And the high-speed workability decreases.

In the case of a composition using high-density polyethylene, it is common to mix a fatty acid metal salt, for example, calcium stearate, for the purpose of capturing free chlor contained in the catalyst residue and the purpose of a release agent. If the compounding amount exceeds 500 ppm, the adhesion to the paper base material is deteriorated. From these problems, the amount of the fatty acid metal salt to be blended, for example, calcium stearate, needs to be 500 ppm or less.

The polyethylene composition for resin-coated paper according to the present invention includes 30 to 70 parts by weight of a high-density polyethylene resin component having the above-mentioned physical properties and a polyethylene resin having the above-mentioned physical properties.
A high-pressure low-density polyethylene resin component having a low melt elasticity index of 0 to 60 parts by weight and a high-pressure low-density polyethylene resin component having a high melt elasticity index of 10 to 40 parts by weight having the above-mentioned physical properties. is there.

When the proportion of the high-density polyethylene resin component is 30
If the amount is less than parts by weight, the density of the composition after mixing becomes low, and the product properties such as moisture resistance and heat resistance are reduced, and the secondary workability such as cutability is also deteriorated. Conversely, when the proportion of the high-density polyethylene is more than 70 parts by weight, not only does the processability deteriorate, but also the adhesive strength with the paper base material decreases, and the amount of smoke generated during processing increases. Further, when the proportion of the high-pressure low-density polyethylene resin component having a low melt elasticity index is less than 10 parts by weight, compatibility after melt mixing deteriorates, adversely affects high-speed processability, and adheres to a paper substrate. The power also decreases. If the amount exceeds 60 parts by weight, neck-in may increase and productivity may decrease, and the amount of smoke generated during processing may increase, which may hinder long-term continuous operation. Furthermore, the amount of the high-pressure low-density polyethylene resin component having a high melt elasticity index is 10%.
When the amount is less than the weight part, not only the edge of the resin film becomes unstable at the time of processing, so that sufficient high-speed processability cannot be obtained, but also the neck-in becomes large and productivity is deteriorated. If this amount is 40
If the weight is exceeded, the stability of the ears during processing increases, and processing with good neck-in becomes possible.However, high-speed processing is inferior and the adhesion to the paper substrate may be adversely affected. is there.

The good primary and secondary workability and high product properties in the present invention are considered to be due to the strictly controlled primary structure of each raw material and viscoelastic properties. Achieving high moisture-proof performance and heat-resistance performance, and good workability only when the melt elasticity index after mixing is 1.2 g or more, and the low-density polyethylene used has two or more components. It is considered that good adhesiveness can be achieved only when the physical properties of each component have a specific correlation.

Further, the amount of smoke components in the high-density polyethylene is reduced, and the amount of smoke generated during processing can be suppressed by strictly controlling the compounding amount of each component, so that long-term continuous operation can be achieved. It is considered to be.

As the method of melt-mixing the high-density polyethylene with the above mixing ratio and the high-pressure low-density polyethylene, various commonly used methods can be used. For example, a single-screw extruder, a twin-screw extruder, etc. , A Banbury mixer, a pressure kneader, a heating roll kneader and the like. In the present invention, when laminating in a dry-blended state without melt-mixing the components in advance, deterioration of workability or adhesion due to insufficient mixing, generation of gel, etc. may be observed. It is not preferable because there is.

Various additives can be mixed with the polyethylene resin composition used in the resin coating layer within a range not to impair the effects of the present invention. Examples of the additives include an ultraviolet absorber, a heat stabilizer, and an oxidizing agent. Additives such as an antistatic agent, an antistatic agent, a nucleating agent, and a coloring agent may be mixed. These additives can be mixed in advance during the production of the high-density polyethylene and the high-pressure low-density polyethylene, added during melt-mixing of both, or added during processing in a so-called master batch method.

The processing of the polyethylene composition for resin-coated paper of the present invention is carried out by an extrusion laminating method, and the film is formed on a previously prepared paper base material from a slit die connected to an extruder. Melt-coated resin. The temperature of the molten resin is usually preferably 270 to 340 ° C.

Before coating the polyethylene resin composition of the present invention on a paper substrate, the paper substrate is preferably subjected to an activation treatment such as a corona discharge treatment or a flame treatment.
It is also an effective method to apply an oxidation treatment such as an ozone treatment to the adhesive surface of the molten resin film to the paper substrate. The thickness of the resin film is not particularly limited, but is generally applied to about 5 to 60 microns.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples unless it exceeds the gist thereof.

[0041]

Example 1 Calcium stearate 300 ppm in advance
MFR 30 g / 10 min, density 0.971
g / cm ³ , 18 and 2 carbon atoms extracted with chloroform
50 parts by weight of a high-density polyethylene (A in Table 1 described later) in which the total value of each component is 180 ppm;
2 g / 10 min, high density low density polyethylene having a density of 0.916 g / cm ³ and a melt elasticity index of 3.5 g (see Table 2 below)
B) 30 parts by weight, MFR 2.0 g / 10 min, density 0.
918 g / cm ^3, a high-pressure low-density polyethylene (Table 1 below a) 20 parts by weight of the melt elasticity index 8.0g melt mixed by a single-screw extruder, laminating the composition at a resin temperature of 320 ° C. processed. At this time, kraft paper having a basis weight of 75 g / m ² which had been subjected to corona treatment of 2 kw was used as a paper base material, and processed so that the thickness of the resin layer was 5 to 30 μm.

The evaluation of the primary workability during the melt coating of the resin was carried out by measuring the rate at which surging occurs as a measure of high-speed workability, and measuring the neck-in by measuring the lateral length of the coated portion. The evaluation criterion for high-speed workability is divided into four stages, ◎: Processing at 280 m / min or more is possible, ○: 250
m / min or more, Δ: 180 m / min or more, x: less than 180 m / min. As the neck-in evaluation criterion, the total value of the neck-in on both sides exceeds 設定: within 10%, ：: within 15%, Δ: within 25%, and ×: exceeds 25% with respect to the set width of processing. , As shown. The amount of smoke generated was measured and collected by a suction duct at the top of the slit die attached to the extruder using a suction duct, and the amount of smoke generated during processing was quantified by a particle counter mounted 5 m away from the suction unit. Was done. The evaluation criteria for the amount of smoke generated are gas 1 guided to the particle counter.
The amount of the smoke component having a size of 0.3 micron or more in a liter is represented as ◎: less than 10,000, ：: less than 20,000, Δ: less than 50,000, ×: 50,000 or more .

Regarding the secondary workability of the processed resin-coated paper, the processing conditions were set so that the processing speed was 60 m / min and the thickness of the resin layer was 20 μm, and the edge of the coated paper was cut by a trimming device. The determination was made based on the cutting situation of the resin layer at this time. The evaluation criteria were as follows: ：: the resin layer was completely cut without cutting waste, ：: the resin layer was stretched at the cut portion, but there was no problem in practical use, △: cut The evaluation was made in such a manner that traces of the resin being extended were observed in the portions, but there were no uncut portions, and x: there were portions where the resin layer was not cut.

Evaluation of the adhesiveness to the paper substrate was performed by a bond tester method in which compressed air was applied from the paper side of the coated paper.
As an evaluation standard, 3.5 kg / cm ² was applied to a resin-coated paper coated with a 20-μm resin film at a processing speed of 60 m / min.
で: The area of the peeled portion was 0%, ○: The area of the peeled portion was less than 5%, Δ: The area of the peeled portion was 20%. Less than, ×:
The area of the peeled portion was expressed as 20% or more.

As a method for evaluating the gel, the molten resin film 16
Evaluation was made based on the number of gels having a size of 0.1 mm or more in 00 cm ² . The evaluation criteria were as follows: ：: less than 5, ：: less than 10, Δ: less than 30, ×: 30 or more.

The heat resistance was evaluated by applying a resin-coated paper coated with a 20-micron resin film at a processing speed of 60 m / min.
The sample was cut into a square of cm, and the sample was left in an oven at 130 ° C. for 60 seconds, and the number of pinholes was measured. The criteria are: ◎: 2 or less, ○: 5 or less, Δ: 10 or less,
X: Expressed as 11 or more. The detection of pinholes was performed using a staining solution in which Sudan III was dissolved in n-hexane.

High-density polyethylene A used in this example
Tables 1 and 2 show the physical properties of the low-density polyethylenes a and b. Also, the mixing ratio of high-density polyethylene and high-pressure low-density polyethylene used in this example,
Table 3 shows the physical properties of the composition after melt mixing, and Table 4 shows the results of the processability and product physical properties evaluated using these resins. The overall judgment in Table 4 was based on the following evaluation criteria for the performance of each item evaluated in light of the above evaluation criteria. That is, ◎: が is 5
There are at least two items, and items other than ◎ are not △ or ×, ○: The number of ◎ is less than 5, but all other items are ○, and Δ: 3 items are evaluated. And the other items do not have a rating of x, and x: those having at least one x item.

[0048]

Examples 2 to 8 In place of the combination of the high-density polyethylene and the high-pressure low-density polyethylene used in Example 1, high-density polyethylenes A to G shown in Table 1 and high-pressure low-density polyethylene shown in Table 2 Using a to g, a resin-coated paper was produced in the same manner as in Example 1 using the compositions of the combinations shown in Table 3, and the processability and product properties at that time were evaluated.

Each of the high-density polyethylenes used in the examples had 300 ppm of calcium stearate blended in advance. Table 4 shows the results of each evaluation.

From the results shown in Table 4, the resin composition obtained by blending the specified amount of the high-density polyethylene resin component having the physical properties specified in the present invention and the two high-pressure low-density polyethylene resin components, and The density is 0.935g / c
In m ³ or more, melt elasticity index than 1.2g, the polyethylene resin composition amount of calcium stearate is 500ppm or less is very good lamination processability, amount of smoke during processing is also very small, It is understood that the adhesiveness to the paper base material is excellent, and that the product properties of the resin-coated paper are also excellent.

[0051]

Comparative Examples 1 to 10 In Comparative Examples 1 to 10, except that the combinations of the high-density polyethylene and the high-pressure low-density polyethylene used in Example 1 were evaluated using various combinations shown in Table 5, respectively. In the same manner as in Example 1, workability, product physical properties and the like were evaluated. The high-density polyethylene used in each comparative example was prepared by previously blending 300 ppm of calcium stearate. However, in comparative example 6, the blending amount of calcium stearate after melt mixing was 560 ppm. , Added during melt mixing.

Table 6 shows the results of the evaluation.

From the results shown in Table 6, when the requirements of the present invention are not completely satisfied, good results cannot be obtained in all of the laminating properties of these compositions and the physical properties of the resin-coated paper. For example, the density after melt mixing is 0.935 g / cm
^{When it is} less than ³ (Comparative Examples 1, 8, and 10), the secondary workability deteriorates, and when the blending amount of the high-density polyethylene exceeds 70 parts by weight (Comparative Example 3), high-speed processability, neck-in, etc. Workability deteriorates. The total value of the components having 18 and 20 carbon atoms contained in the high-density polyethylene is 500 ppm.
(Comparative Examples 1 and 6), the amount of smoke generated during processing is extremely large.

Further, when the value of the melt elasticity index after melt mixing is less than 1.2 g (Comparative Examples 2 and 3), the processability is poor,
Conversely, when the melt elasticity index exceeds 15 g (Comparative Example 10)
Has a disadvantage that it is inferior in high-speed workability and secondary workability. When the MFR of the low melt elasticity resin exceeds 20 (Comparative Example 4), the neck-in deteriorates, and the MFR of the high-density polyethylene increases.
When the FR is less than 5 g / 10 min (Comparative Example 5), the high speed processability is deteriorated, and when the MFR of the high melt elasticity index resin is less than 0.2 g / 10 min (Comparative Example 7), However, disadvantages such as the generation of a gel are also observed. When at least two components of the high-pressure low-density polyethylene required for the present invention are not blended (Comparative Examples 8 and 9), sufficient high-speed processability is not obtained, and a result that adversely affects neck-in and smoke is not obtained. It became. It is clear that the adhesiveness also deteriorates when the amount of calcium stearate to be blended exceeds 500 ppm (Comparative Example 6).

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

[Table 3]

[0058]

[Table 4]

[0059]

[Table 5]

[0060]

[Table 6]

[0061]

EFFECTS OF THE INVENTION The polyethylene composition of the present invention has excellent molding processability, particularly high-speed processability, in resin coating processing using paper as a base material, and the amount of smoke generated during molding is very small. Even in continuous operation, there is no defect such as peeling of the product or dropping of oil smoke, the adhesion between the resin film and the paper substrate is very good, and it is possible to provide a polyethylene resin-coated paper excellent in moisture resistance and heat resistance. .

Claims (1)

[Claims] 1. A resin having a density of 0.950 g / cm ³ or more, a melt flow rate of 5.0 to 45 g / 10 min, and a total value of components having 18 and 20 carbon atoms of 500 ppm or less when extracted with chloroform. Some high density polyethylene resin 3
0 to 70 parts by weight, a density of 0.930 g / cm ³ or less, a melt flow rate of 2 to 20 g / 10 min, and a high pressure method low density polyethylene in which the relationship between the melt flow rate and the melt elasticity index satisfies the following formula (1). 10 to 60 parts by weight of resin, density of 0.930 g / cm ³ or less, and melt flow rate of 0.
2 to 8 g / 10 min, 10 to 40 parts by weight of a high-pressure method low-density polyethylene resin in which the relationship between the melt flow rate and the melt elasticity index satisfies the following formula (2). in .935g / cm ³ or more, melt elasticity index above 1.2 g 15 g or less, a resin-coated paper for the polyethylene resin composition amount of fatty acid metal salt to be blended is 500ppm or less. MT ≦ −0.4 log (MFR) +4.0 (1) MT ≧ −0.5 log (MFR) +4.2 (2) where MT in the formulas (1) and (2) is a melt elastic resin. , MFR represent the melt flow rate.