JP2000319456A - Resin composition for molding inflation film and its masterbatch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition which can give a molding with its surface having improved printability while improving the working environment by preventing the resin powder from dusting by adding a polyethylene resin having an MFR of a specified or larger value, a polypropylene resin, and an inorganic powder in the production of a high-density polyethylene. SOLUTION: This composition comprises 100 pts.wt. (A) high-density polyethylene resin of an MFR of 0.01-0.5, 0.2-20 pts.wt. (B) polyethylene resin of an MFR of at least 0.05, 0.01-5 pts.wt. (C) polypropylene resin, and 0.01-10 pts.wt. (D) inorganic powder of a mean particle diameter of 0.5-30 μm. The inorganic filler is desirably silica. The ratio component C/component D is 1/9 to 9/1. To produce the composition, it is desirable to use a masterbatch prepared by mixing 100 pts.wt. component B with 1-30 pts.wt. component C, and 1-50 pts.wt. component D. Component A (100 pts.wt.) is mixed with 0.5-15 pts.wt. of the above masterbatch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inflation film molding for eliminating resin powder which bleeds on the film surface generated during the production of an inflation film using a high-density polyethylene resin, that is, so-called dusting. The present invention relates to a resin composition and a master batch thereof.

[0002]

2. Description of the Related Art In the production of a film by a thermoplastic resin inflation molding machine, air is fed into a tube-like film melt-extruded from an extruder die, and a soft tube is formed in a state where it is not yet solidified. After being expanded, it is gradually crushed into a flat shape using a guide plate (or a stabilizing plate) or a take-up roll and wound up into a roll, and is used for various purposes. In particular, an inflation film using a high-density polyethylene resin is excellent in mechanical properties such as tensile strength and breaking strength, and there is a growing demand for a molded product taking advantage of this characteristic, such as a shopping bag or a shopping bag.
At this time, in the case of film production by the inflation method of high-density polyethylene, generally, the resin melting temperature is required to be 180 ° C. or more, and furthermore, as the production process is speeded up, operation at a higher temperature is required in recent years. .

Since a high-density polyethylene resin film is produced at such a high temperature, low molecular weight portions and additives in the resin are likely to bleed onto the film surface. In particular, this tendency is remarkable when a high-density polyethylene resin having a small MFR of 0.01 to 0.5, which has been actively developed in recent years, is used. As described above, in the film molding using the high-density polyethylene resin, the powdery resin substance produced as a bleed material has a strong tendency to be generated and adhered to the film surface, and not only the working environment is deteriorated and the operation stability is deteriorated, but also This is inferior in the printability of the surface of the molded product and causes a decrease in commercial value.

[0004] These phenomena are caused by the fact that in the process of producing a film by the inflation method, resin powder generated by a bleed or the like near a guide plate or a take-up roll device of the same device in contact with the film surface is scattered. The working environment has been reduced, and the quality of the film has deteriorated. As a method of reducing the occurrence of such resin powder, a method of improving the slipperiness of the film surface,
For example, Japanese Patent Application Laid-Open No. 06-166775 discloses a method of improving the slipperiness by adding silica during the production of a polypropylene resin film. It does not provide a good slip effect.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present inventors
In the inflation method, when manufacturing high-density polyethylene resin film with MFR 0.01 to 0.5, which is used for shopping bags, shopping bags, etc., molded products obtained by improving the working environment by preventing the generation of resin powder We studied the development of a resin composition for inflation film molding with improved surface printability.

[0006]

SUMMARY OF THE INVENTION Therefore, claim 1 of the present invention is provided.
The invention relates to an inflation method in which 1 to 30 parts of a polypropylene resin and 1 to 50 parts of an inorganic powder having an average particle size of 0.5 to 30 μ are blended with 100 parts by weight of a polyethylene resin having an MFR of 0.05 or more (hereinafter abbreviated as “parts”). We have developed a masterbatch for molding the film. The master batch according to claim 1, wherein the master batch base resin is MFR 0.05 (MFR 0.05) in order to prevent a large amount of resin powder which has conventionally been generated during the production of a high-density polyethylene film by the inflation method. J
IS-K-6760 measurement) The above polyethylene resin was used, and a polypropylene resin and an inorganic powder were blended as an additive for preventing the generation of resin powder.

In the master batch of the present invention, the use of polypropylene greatly reduces the generation of resin powder due to bleed and the like when producing a film, as compared with a conventional product using inorganic powder alone. is there. Master of the present invention
Examples of the polyethylene resin having an MFR of 0.05 or more used in the batch include a low density polyethylene resin, a linear low density polyethylene resin, a high density polyethylene resin, an ethylene vinyl acetate copolymer, and an ethylene acrylic copolymer.
On the other hand, if the MFR of these resins is smaller than 0.05, the master batch of the present invention is insufficiently diffused by kneading with a diluting (natural) resin during film production, which is not preferable. Examples of the polypropylene resin used in the present invention include various polypropylene resins such as homo, block, and random.
Examples of the inorganic powder having an average particle size of 0.5 to 30 μ used in the present invention include calcium carbonate, talc, silicic acid (silica), silicate and the like. Particularly, silica (silicic acid) and silicate are most preferable.

[0008] According to the composition of the present invention, when producing a high-density polyethylene film by the inflation method,
The present invention provides a master batch that can be easily kneaded, and has an effect of preventing the generation of resin powder and the like on the film surface. According to the second aspect of the present invention, in producing the masterbatch for inflation film molding according to the first aspect, in order to exhibit the most excellent effect of preventing the generation of resin powder, which is the object of the present invention, first, After kneading the polypropylene resin and the inorganic powder, this mixture is kneaded with the polyethylene resin to form a master in which the three components are uniformly mixed.
By producing a batch, a resin powder (powder wipe) is not generated when a film is formed, and the most excellent effect of the present invention is exhibited.

In the invention of claim 3, 0.2 to 20 parts of a polyethylene resin having an MFR of 0.05 or more, 0.01 to 5 parts of a polypropylene resin and 0.01 to 10 parts of an inorganic powder are added to 100 parts of a high-density polyethylene resin having an MFR of 0.01 to 0.5. The present invention provides a resin composition for molding an inflation film, wherein the resin composition is prepared by blending parts.
In the process of producing an inflation film using the resin composition, no resin powder was generated due to bleeding on the surface of the molded product.
No resin powder or the like is generated and scattered at the place where the film comes into contact with a film device or the like. The polyethylene resin having an MFR of 0.05 or more blended in the present invention has an MFR of less than 0.05.
Ingredients (master for inflation film molding)
Batch) is inferior in diffusivity to high-density polyethylene resin, which is not preferred. The amount of polyethylene resin used is 0.
If the amount is less than 2 parts, the component according to claim 1 is inferior in diffusibility with high-density polyethylene resin, which is not preferable. On the other hand, if it is more than 20 parts, the physical properties of the obtained film molded article are impaired, which is not preferable.

The amount of the polypropylene resin used in the present invention is 0.
01 to 5 parts, and if less than 0.01 part, it is difficult to prevent the generation of bleed resin powder, which is not preferable.
If it exceeds 5 parts, the physical properties of the molded product (film) may be impaired, which is not preferable. Average particle size used in the present invention 0.5-3
The use amount of the inorganic powder of 0μ is 0.01 to 10 parts, and if less than 0.01 part, the generation of resin powder is not preferable, and
If it exceeds 10 parts, the physical properties of the molded article may be impaired, which is not preferable. According to the fourth aspect of the present invention, silica is specified as the inorganic powder exhibiting the greatest effect of inhibiting the generation of resin powder. Examples of the silica include natural and synthetic silicic acids and silicates.

[0011] In a fifth aspect of the present invention, the compounding ratio of the polypropylene resin and the silica powder is from 2: 8 to 8:
When the ratio is within the range of 8: 2, the most excellent effect of preventing the generation of resin powder during film molding, which is an important object of the present invention, is exhibited. That is, when it is within the above range, the blending of the polypropylene resin and the silica powder in claim 3 is optimal.

According to a sixth aspect of the present invention, there is provided an inflation film molding method comprising mixing the inflation film molding master batch of 0.5 to 15 parts with 100 parts of a high density polyethylene resin having an MFR of 0.01 to 0.5. This is a method for producing a resin composition for use. According to the manufacturing method of the sixth aspect, when the resin composition of the sixth aspect is used, the most excellent film is provided. As a method for producing a film having improved printability by preventing the generation of resin powder (powder wipe), the object of the present invention is to produce a masterbatch for molding an inflation film by the method described in claim 2. When a film is molded using the product of the present invention according to claim 3, manufactured by the method according to claim 6, wherein the master batch and the high-density polyethylene resin are kneaded, resin powder is generated. And a film excellent in printability can be obtained.

The product of the present invention may contain an antioxidant, a heat stabilizer, an antistatic agent, a lubricant and the like as long as the physical properties are not impaired. Further, the resin composition for molding an inflation film of the present invention may be mixed with a coloring agent or a color compound which has been conventionally used in the production of the film to produce a film. Alternatively, a master batch may be used in combination with a coloring agent or an additive. Examples and comparative examples are described below.

Example 1 Using an extruder, 39 parts of an MFR 9.0 random polypropylene (product of Grand Polymer Co., Ltd .: F229D), average particle size
60 parts of 2.7 μm silica powder and 1 part of a fatty acid metal salt are melt-kneaded to obtain a mixture. 5 parts of the above mixture, density 0.959, MF
R1.0 polyethylene (Keiyo Polyethylene Co., Ltd. product:
E8082) 95 parts are melt-kneaded using an extruder to obtain an inflation molding master batch of the present invention. Next, 5 parts of the master batch and 95 parts of a high-density polyethylene having a density of 0.950 and an MFR of 0.06 (HF310, a product of Nippon Polychem Co., Ltd.) were mixed by a tumbler, and the resin composition for molding an inflation film of the present invention was prepared. obtain. The composition ratio of the inflation film molding resin composition is such that, with respect to 100 parts of a high-density polyethylene resin having an MFR of 0.06, 4.75 parts of a polyethylene resin having an MFR of 1.0, 0.098 part of a polypropylene resin and 0.15 part of silica. .

Next, the resin composition for molding an inflation film is applied to an inflation molding machine (extruded diameter of 40 m).
m, and a die diameter of 50 mm), and an inflation film was formed at a temperature of 190 ° C. and a film thickness of 0.025 mm. Table 1 shows the results of the following measurements (a) and (b) performed using this film. The mechanical properties such as tensile strength and elongation of the film were almost the same as those of the above inflation film using high-density polyethylene alone. Hereinafter, the same evaluation test as in Example 1 was performed for Examples 2 to 4 and Comparative Examples 1 to 7, and the results are shown in Table 1.

(A) Generation of resin powder (= powder scattering) In the process of film production by the inflation method, the guide plate of the device (opening angle 70 degrees) with which the surface of the molded film comes into contact.
And the state of scattering of resin powder (powder scattering) generated in the vicinity of the take-up roll device is visually judged according to the following criteria for the contamination state around the device after operating for 3 hours under the manufacturing conditions of Example 1. …: Resin powder scatter near the guide plate is very small. …: A lot of resin powder is scattered near the guide plate. X: The scattering of the resin powder in the vicinity of the guide plate is extremely large. (B) Printability The printing of shopping bags produced by the inflation method is operated continuously for 3 hours, and immediately after that, the printed matter is visually observed, and the occurrence of plate fog and streaks is determined according to the following criteria. Determine. ◎… Not seen at all. …: Slight occurrence. ×: Very many occurrences.

[0017]

[Table 1]

Example 2 Example 1 was repeated except that the silica used in Example 1 was changed to zeolite (available from Mizusawa Chemical Co., Ltd .: Shilton JC-70).
Is the same as The mechanical properties such as tensile strength and elongation of the film were measured by the inflation
The physical properties were almost the same as those of the film. Example 3 Example 3 was the same as Example 1 except that the silica used in Example 1 was changed to calcium carbonate (trade name: MAX1180, manufactured by Takehara Chemical Co., Ltd.) having an average particle size of 5 μm. The mechanical properties such as tensile strength and elongation of the film were almost the same as those of the inflation film using high-density polyethylene alone. Example 4 The polyethylene used in Example 1 was a low-density polyethylene having a density of 0.92 and an MFR of 5.0 (Ube Industries, Ltd .: F522).
It is the same as the first embodiment except for the replacement. The mechanical properties such as tensile strength and elongation of the film were almost the same as those of the inflation film using high-density polyethylene alone.

Comparative Example 1 In the composition ratio of the resin composition for molding an inflation film of Example 1, the MFR1.0 polyethylene resin was added in an amount of 0.005%.
Example 1 is the same as Example 1 except that it is blended so as to be parts. Comparative Example 2 The same as Example 1 except that in the composition ratio of the inflation film forming resin composition of Example 1, MFR1.0 polyethylene resin was blended so as to be 30 parts. Comparative Example 3 In the composition ratio of the resin composition for inflation film molding of Example 1, 0.005% of random polypropylene was added.
Example 1 is the same as Example 1 except that it is blended so as to be parts.

Comparative Example 4 In the composition ratio of the resin composition for molding an inflation film of Example 1, the procedure was the same as that of Example 1 except that 10 parts of polypropylene was blended. Comparative Example 5 In the composition ratio of the inflation film forming resin composition of Example 1, the same operation as in Example 1 was carried out except that silica was added so as to be 0.005 part. Comparative Example 6 The composition of the resin composition for molding an inflation film of Example 1 was the same as that of Example 1 except that the silica was added so as to be 15 parts. Comparative Example 7 In the composition of the inflation film molding resin composition of Example 1, except that polypropylene was not used.
All are the same as the first embodiment.

[0021]

The resin composition for molding an inflation film according to the present invention can be used for forming a resin powder on a film surface which is considered to be caused by the presence of a low molecular weight portion or an additive in the resin even at a high temperature during film forming. No dusting occurs. For this reason, conventional inflation molding machines, especially guide plates (stabilizing plates)
Deterioration of the working environment due to the generation of resin powder in the vicinity is also eliminated. Moreover, it has excellent mechanical properties such as tensile strength and breaking strength, and is most suitable as a molded article such as a shopping bag or shopping bag. Further, since no resin powder adheres to the film surface, a beautiful printed matter having excellent printability is obtained, and the commercial value is enhanced.

Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) B29K 23:00

Claims (6)

[Claims] Claims: 1. A polyethylene resin having an MFR of 0.05 or more, 100 parts by weight of a polyethylene resin, 1 to 30 parts by weight of a polypropylene resin and an average particle size of 0.5.
A masterbatch for inflation film molding, comprising 1 to 50 parts by weight of an inorganic powder having a particle size of 30 μm. 2. The inflation method according to claim 1, wherein after kneading the polypropylene resin and the inorganic powder, the kneaded material is added to the polyethylene resin and kneaded.
A method for manufacturing a masterbatch for molding film. 3. A high-density polyethylene resin having an MFR of 0.01 to 0.5.
For 100 parts by weight, MFR 0.05 or more polyethylene resin 0.
A resin composition for inflation film molding, comprising 2 to 20 parts by weight, 0.01 to 5 parts by weight of a polypropylene resin, and 0.01 to 10 parts by weight of an inorganic powder having an average particle size of 0.5 to 30 μm. 4. A resin composition for molding an inflation film, wherein the inorganic powder according to claim 3 is silica. 5. The inflation according to claim 4, wherein the mixing ratio of the polypropylene resin and the silica powder is 1: 9 to 9: 1.
A resin composition for molding a film. 6. A high-density polyethylene resin having an MFR of 0.01 to 0.5.
A method for producing a resin composition for inflation film molding, comprising 0.5 to 15 parts by weight of the masterbatch for inflation film molding according to claim 1 in 100 parts by weight.