JP2001240082A - Fitting tool and packaging bag with the fitting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fitting tool and a bag with the fitting tool provided with the adequate flexibility and superior welding properties, free from creases and the like in the manufacture of the bag also provided with the superior welding properties at the low temperature. SOLUTION: A pair of fitting tools to be fitted each other and the bag with the fitting tools are provided, and at least a fitting fool welding section is a random copolymer composed of a polypropylene and an α-olefin of 4C or more, and following conditions are satisfied in the constitution of the copolymer: (1) the content of the α-olefin of 4C or more in the copolymer is 10-30 wt.%, (2) a cold xylene soluble ratio of the copolymer is 15-60 wt.%, and (3) a boiling n-heptane insoluble ratio of the copolymer is composed of a copolymer satisfying 7 wt.% or more. Also the fitting tool is composed of a resin composition composed of a copolymer and another copolymer constituted of the above copolymer, a urethane and a propylene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a fitting and a bag with a fitting, which are required to be moisture-proof and oxygen-proof for food, medicine, miscellaneous goods and the like.
In addition, it can be used for packaging in fields that require resealing after opening.

[0002]

2. Description of the Related Art Bags (chuck bags) which can be freely opened and closed by providing male and female band-shaped fittings at the opening of the bag are used in many fields such as foods, medicines and miscellaneous goods. . Various methods have been proposed as a method for manufacturing the fitting-equipped bag. For example, a method of extruding and forming a tubular film having a pair of male and female fittings integrally using an annular die, extruding the fitting portion into a film shape, and welding to a laminate film or the like. There is a method in which a tape with a fitting is manufactured in advance, and the tape is fixed to a base film forming the bag body by heat welding or an adhesive.

[0003] However, in the former two methods, there are limitations on the types of resins that can be used, it is difficult to apply the resin to a multilayer film substrate, it cannot be applied to various sizes, and printing is difficult. However, in recent years, a method in which a tape with a fitting is manufactured in advance and thermally welded to a bag main body film has been adopted.

[0004]

[Problems to be solved] By the way, as the material of the fitting,
Polypropylene resin (PP) is widely used, and the welding temperature of this PP is as high as about 160 ° C. For this reason, there is a problem that it takes time to raise the temperature of the welding site, the bag making speed must be reduced, and the production efficiency is reduced. In addition, since the welding temperature is high, there is also a problem that energy cost is high, and seal wrinkles are generated on the appearance, thereby deteriorating product quality. Further, the rigidity is relatively high, and handling is not always easy depending on the use object.

[0005] Therefore, from the standpoint of improving production efficiency, energy saving and appearance improvement, there is a demand for a material having a lower melting temperature, a higher bag making speed, and an appropriate rigidity and flexibility. From such a background, as a PP-based fitting, a fitting made of a resin composition of a crystalline polypropylene copolymer and an ethylene-based copolymer (JP-A-59-492).
49) has been proposed. The blending of the ethylene-based resin tends to improve the sealability, but at the same time, the rigidity is reduced. In order to provide sufficient low-temperature sealing properties, a considerable amount of ethylene resin must be blended, and a decrease in rigidity accompanying an increase in the blending amount lowers the fitting strength and impairs the reseal function. Further, the resin composition is a heterogeneous resin composition and does not have satisfactory performance such as a decrease in commercial value due to poor appearance due to problems such as compatibility.

[0006]

Means for Solving the Problems The present inventor has made intensive studies to solve the above-mentioned problems, and as a result, has found that a specific resin is selected for a welding member of a fitting to lower the welding temperature. Were found to be able to solve the above-mentioned problems with appropriate flexibility, and based on this finding, the present invention was completed.

That is, according to the present invention, there is provided a pair of fittings which can be fitted to each other, wherein a welded portion to the bag body is formed of the following resin, and this fitting is provided. The present invention relates to a fitting-equipped packaging bag characterized by being welded to a bag body. It is a random copolymer of propylene and an α-olefin having 4 or more carbon atoms, and the content of the α-olefin having 4 or more carbon atoms in the copolymer is 10 to 30% by weight. (A) The copolymer (A) which has a boiling n-heptane-insoluble portion of 15 to 60% by weight of the copolymer.

The resin used in the present invention may be the above-mentioned copolymer (A) alone or a blend of the same resin and another resin. The resin to be blended has an ethylene content of 3.5 to 6. A random copolymer (B) of propylene and ethylene of 0 wt% is preferred, and the blend ratio of the copolymer (A) is 100 to 15 wt%, and the copolymer (B)
Is 0 to 85 wt%.

Hereinafter, the present invention will be described in detail. The copolymer (A) to be used in the present invention can be produced by a solution polymerization method of polymerizing in a solution or a gas phase polymerization method of polymerizing in a gas phase, but is not particularly limited to these production methods.

The copolymer (A) used in the present invention uses an α-olefin having 4 or more carbon atoms as a comonomer.
Examples of the α-olefin having 4 or more carbon atoms include butene-1,
Pentene-1, hexene-1, 4-methylpentene-1
And the like alone or in combination, butenes are particularly preferred.
1 is most preferred.

The content of the α-olefin having 4 or more carbon atoms in the copolymer (A) used in the present invention is 10 to 30% by weight, preferably 12 to 28% by weight. Α with 4 or more carbon atoms
-When the olefin content is below the lower limit, the low-temperature heat sealing property of the fitting is insufficient, which is not preferable. When the olefin content exceeds the upper limit, the slipping property of the fitting is deteriorated.

The copolymer (A) used in the present invention has a cold xylene-soluble portion (CXS) of 15 to 60% by weight.
-50 wt% is more preferable. If the CXS falls below the lower limit, the low-temperature heat sealability of the fitting becomes insufficient, and the CXS
Is more than the upper limit, it is not preferable because the slipperiness of the fitting becomes poor.

Boiling n of the copolymer (A) used in the present invention
-Heptane insoluble part (BHIP) is 7 wt% or more,
10 wt% or more is more preferable. If the BHIP is below the lower limit, the slipperiness of the fitting becomes poor, which is not preferable.

The resin used in the present invention may be the copolymer (A) alone or a blend of the same resin and another resin. The resin to be blended has an ethylene content of 3.5 to 6.0 wt. % Of a random copolymer (B) of propylene and ethylene is preferred, and the blend ratio of the copolymer (A) is 100 to 15 wt%, and the copolymer (B)
Is 0 to 85 wt%.

The copolymer (B) used in the present invention has an ethylene content of 3.5 to 6.0 wt%, and 4.5 to 5.0 wt%.
8 wt% is more preferable. If the ethylene content is lower than the lower limit, the low-temperature heat sealability of the fitting is deteriorated, which is not preferable. If the ethylene content exceeds the upper limit, the slipperiness of the fitting becomes poor, which is not preferable.

The blend ratio of the copolymer (A) and the copolymer (B) used in the present invention is 100 to 1 for the copolymer (A).
5 wt%, the copolymer (B) is 0 to 85 wt%, preferably the copolymer (A) is 80 to 30 wt%, and the copolymer (B) is 20 to 70 wt%. If the blending ratio of the copolymer (A) is below the lower limit, the low-temperature heat sealability of the fitting is deteriorated, which is not preferable.

In the present invention, the shape of the fitting is not particularly limited, and may be any known shape as long as it has a re-opening / closing function. In addition, if necessary, known additives such as a stabilizer, an antioxidant, a lubricant, an antistatic agent, and a coloring agent can be used within a range not to impair the purpose of the present invention.

[0018]

According to the present invention, the fitting and the bag with the fitting according to the present invention are a specific polypropylene-based copolymer (A) alone or a random copolymer (B) of a specific copolymer (A) with a specific propylene and ethylene. ) Is used as a material, so that it is excellent as a re-opening / closing function, and is suitable as a fitting having excellent flexibility and low-temperature heat sealability, and a bag with a fitting.

[0019]

The present invention will now be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. The α-olefin content of the resin used in the following Examples and Comparative Examples, cold xylene soluble part (CXS),
The boiling n-heptane insoluble part (BHIP) was determined by the following method.

Α-Olefin content (C4): Determined from a characteristic absorption at 770 cm -1 using an infrared spectrophotometer using a calibration curve prepared from a standard substance.

Cold xylene-soluble part: 5 g of a polymer is dissolved in 500 ml of xylene, and then slowly cooled to room temperature. Then, the mixture was allowed to stand in a bath at 20 ° C. for 4 hours, filtered, and the filtrate was concentrated, dried, dried and weighed.

Boiling n-heptane insoluble part: Extraction is carried out for 14 hours using a Soxhlet extractor. In addition, the frequency of reflux was set to once every 5 minutes, and the extraction residue was dried and weighed.

Example 1 As a material for the fitting, MFR (melt flow ratio) was 4.0 g / 10 min, butene-1 content was 22.5 wt%, and CXS was 17.0 wt.
%, BHIP is 62.5 wt% of a polypropylene resin (Excellen WS100 manufactured by Sumitomo Chemical Co., Ltd.)
1-1) was prepared.

This polypropylene-based resin is provided with a deformed die having a male part and a female part of a fitting and having a diameter of 40 mm.
Using an extruder having an L / D of 25, the mixture was melt-kneaded at 200 ° C., guided into a cooling water tank and solidified by cooling, and then a winding fitting was obtained with a winding machine. Table 1 shows the evaluation results of the fitting.

Example 2 As a material of the fitting, 70 parts by weight of the polypropylene resin used in Example 1 was used, and the MFR was 6.0 g / 10 mi.
n and an ethylene-propylene random copolymer resin having an ethylene content of 6.0 wt% (Nobrene FL421 manufactured by Sumitomo Chemical Co., Ltd.) was used in the same manner as in Example 1 except that the resin composition was 30 parts by weight. To obtain a fitting. Table 1 shows the evaluation results of the fitting.

Example 3 As a material for the fitting, 30 parts by weight of the polypropylene resin used in Example 1 and ethylene-based resin used in Example 2 were used.
A fitting was obtained in the same manner as in Example 1 except that the propylene random copolymer resin was used in an amount of 70 parts by weight.
Table 1 shows the evaluation results of the fitting.

Example 4 As a material of the fitting, 20 parts by weight of the polypropylene resin used in Example 1 and ethylene-based resin used in Example 2 were used.
A fitting was obtained in the same manner as in Example 1, except that the propylene random copolymer resin was used in an amount of 80 parts by weight.
Table 1 shows the evaluation results of the fitting.

COMPARATIVE EXAMPLE 1 10 parts by weight of the polypropylene resin used in Example 1 and ethylene-propylene random copolymer having an ethylene content of 6.0 wt% used in Example 2 were used as materials for the fitting. A fitting was obtained in the same manner as in Example 1 except that the combined resin was changed to 90 parts by weight of the resin composition. Table 1 shows the evaluation results of the fitting.

Comparative Example 2 The procedure of Example 1 was repeated except that the ethylene-propylene random copolymer resin having an ethylene content of 6.0 wt% used in Example 2 was 100 parts by weight as a material of the fitting. Similarly, a fitting was obtained. Table 1 shows the evaluation results of the fitting.

Comparative Example 3 As a material for the fitting, the MFR was 7.3 g / 10 min, the butene-1 content was 4.3 wt%, and CXS
Was obtained in the same manner as in Example 1 except that 2.2% by weight and BHIP were 80.5% by weight of a polypropylene resin (Noblen WF825-8 manufactured by Sumitomo Chemical Co., Ltd.). Table 1 shows the evaluation results of the fitting.

COMPARATIVE EXAMPLE 4 As a material for the fitting, ethylene having an MFR of 6.0 g / 10 min and an ethylene content of 6.0 wt% was used.
80 parts by weight of a propylene random copolymer resin (Nobrene FL421 manufactured by Sumitomo Chemical Co., Ltd.), MFR is 5.0 g / 10 min, and density is 0.921 g / c.
A fitting was obtained in the same manner as in Example 1 except that a resin composition containing 20 parts by weight of low-density polyethylene (Sumikasen F412-1 manufactured by Sumitomo Chemical Co., Ltd.) having an m ³ of 20 parts by weight was obtained. Table 1 shows the evaluation results of the fitting. The obtained fittings were generally inferior in sealability and nail crushability as compared with the present example, and were particularly inferior in transparency in particular.

Reference Example A polypropylene resin fitting, "San Zip Tape PP-13" manufactured by Itochu Sunplus Co., Ltd. was used as a reference example and used as an evaluation standard.

The bag with the fitting is manufactured by using a three-way bag making machine with zipper “SBM-600-SSG” manufactured by Seibu Kikai Co., Ltd.
Using a two-layer laminate film of OPP (stretched polypropylene film) / CPP (unstretched polypropylene film) (20 μ / 40 μ), the number of shots is 60 shots / min so that the fitting is fused to the CPP film layer side. The bag was made, and the practical sealing temperature was examined. In addition, the crushability of the nail portion was examined.

The crushability of the nail portion was evaluated under the above-described bag making conditions with reference to the reference example and the finished state. The evaluation criteria are as follows.

A: Excellent crushability and very good finish. ：: Good finish without wrinkles or the like. ×: Wrinkles, perforations, etc. occurred, resulting in poor finish.

The fit was evaluated sensory based on the reference example. The evaluation criteria are as follows.

：: Moderate rigidity, good fitting strength, and excellent re-opening / closing function. Δ: Has a re-opening / closing function that is slightly inferior in rigidity but has no practical problem. X: The re-opening / closing function is inferior due to a decrease in fitting strength and the like.

[0038]

As described in detail above, the fitting and the bag with the fitting of the present invention are excellent in low-temperature sealing property, nail crushing property and transparency, which are particularly important evaluation items for the fitting tool. It is also very excellent with a good re-opening / closing function.

[0039]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a front view of a bag with a fitting according to the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, showing the structure of the fitting of the present invention and the fitting part of the bag with the fitting.

[Description of Signs] 1 Bag tool main body with fitting tool 2 Fitting tool section 2a Female fitting tool 2b Male fitting tool

Claims (3)

[Claims] 1. A pair of fittings that can be fitted to each other, wherein the welded portion to the bag body is made of propylene and α having 4 or more carbon atoms.
A random copolymer with an olefin and the following conditions: the content of α-olefin having 4 or more carbon atoms in the copolymer is 10 to 30 wt%; the cold xylene-soluble portion of the copolymer is 15 to 60 wt%. Boiling of the copolymer A copolymer (A) having an n-heptane-insoluble portion of 7 wt% or more satisfies 100 to 15 wt%, and a random copolymer of propylene and ethylene having an ethylene content of 3.5 to 6.0 wt% (B). A fitting comprising a resin composition of 0 to 85 wt%. 2. The fitting according to claim 1, wherein the copolymer component (α-olefin) of (A) is butene-1. 3. A bag is formed by fusing a pair of fittings formed of the resin according to claim 1 and having a fusion portion to the bag main body with each other. Packaging bag with fitting.