JP2006062153A - Packaging bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packaging bag enabling clean packaging which eliminates the leaching of fine particles or a liquid into the heat sealing layer of a laminated film constituting the packaging film to prevent the deterioration of content and capable of rapidly diffusing content which forms gas by decomposition like hydrogen peroxide contained in a second hair dyeing liquid and preventing the expansion bursting of the bag and the ply separation of the laminated film to reduce the diffusion of the content. <P>SOLUTION: The packaging bag is formed by heat-sealing the heat seal layer of a laminated film, which has a heat-sealing layer, the intermediate layer laminated to the heat-sealing layer and the base material layer laminated to the intermediate layer, as the innermost layer. The heat-sealing layer comprises straight chain low density polyethylene obtained using a single site catalyst as a polymerization catalyst and the stem permeability of the laminated film is 4.5 g/m<SP>2</SP>24hr or below and oxygen gas permeability is 40 cc/m<SP>2</SP>24hr or above. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a packaging bag. More specifically, the present invention, for example, is filled with a chemical solution containing hydrogen peroxide such as the second solution for hair dyes, allows oxygen gas generated by the decomposition of hydrogen peroxide to pass through, and heat Packaging with good sealing strength that can prevent expansion, bag breakage, etc., little volume reduction due to permeation and transpiration of water in the second liquid, and no risk of alteration of the contents It relates to bags.

  The second liquid for hair dye contains hydrogen peroxide. If the second liquid is sealed in a bag formed of a laminated film containing aluminum foil, oxygen generated by the decomposition of hydrogen peroxide. The gas expands the bag and the heat seal part peels off or ruptures. In addition, the hair dye component penetrates into the laminated film constituting the bag, reaches the aluminum foil surface as a barrier layer, and peeling of the interface with the heat seal layer etc. in contact with the aluminum foil, so-called delamination occurs. Or

A stretched PET film using a silica vapor deposition layer or the like as a barrier layer and stretched NY as a base material layer, LLDPE or the like as a heat seal layer, the base material layer and the heat seal layer are dry laminated, and a water vapor transmission rate of 2 g / m. ^By making it a packaging bag using a laminated film with a gas permeability of 0.5 cc / m ² · 24 hr or more for ² · 24 hr or less, the gas derived from hydrogen peroxide can be quickly dissipated out of the bag, It is known that expansion, rupture, and delamination of the bag can be prevented, and transpiration of the contents can be reduced (for example, see Patent Document 1).

However, in the thing of patent document 1, since a silica vapor deposition layer etc. are used as a barrier layer, for example, in order to vapor-deposit a silica vapor deposition layer etc. to the stretched PET film as a base material layer, cost is high. I will. Moreover, various additives are used for LLDPE or the like as a heat seal layer. During use as a packaging bag, the additive is leached into the contents as fine particles or liquids, and the contents are the first. There is a drawback of altering the components of the two agents.
JP 2003-116632 A (page 4)

  The present invention was devised as a result of earnest research in view of the above situation, and there is no fine particles or liquid that ooze out from the heat seal layer of the laminated film constituting the packaging bag, and it is stored in the bag. It can be packaged cleanly without altering its contents, and contains contents that generate gas by decomposition, such as hydrogen peroxide contained in the second liquid for hair dyes. However, it is possible to provide a packaging bag that can quickly dissipate out of the bag, prevent the bag from expanding, rupturing, delamination of the laminated film, and reducing the transpiration of the contents. It is an object.

In order to solve the above problems, the packaging bag of the present invention is (1) the laminated film having a heat seal layer, an intermediate layer laminated on the heat seal layer, and a base material layer laminated on the intermediate layer. A packaging bag formed by heat-sealing with a heat-sealing layer as an innermost layer, wherein the heat-sealing layer is a linear low-density polyethylene using a single-site catalyst as a polymerization catalyst, and water vapor permeation as the laminated film The degree is 4.5 g / m ² · 24 hr or less, and the oxygen gas permeability is 40 cc / m ² · 24 hr or more.
(2) Preferably, the intermediate layer is biaxially stretched nylon, and the base material layer is biaxially stretched polyester.
(3) The heat seal layer and the intermediate layer, and the intermediate layer and the base material layer are preferably dry laminated.
And (4) It is preferable to accommodate the 2nd liquid for hair dyes containing hydrogen peroxide.

Since the present invention is configured as described above, the following effects can be obtained.
That is, in this invention, a linear low density polyethylene (hereinafter, “SLLDPE” is used unless otherwise specified) using a single-site catalyst used in the heat seal layer as a polymerization catalyst is an antioxidant. , Neutralizers, slip agents, antiblocking agents and other additives. That is, since the single-site catalyst does not have a halogen component such as chlorine in the polymerization catalyst, it is necessary to add a halogen catcher (neutralizing agent) such as a fatty acid metal salt for neutralizing the halogen component. In addition, there is no need to contain an antioxidant, slip agent, anti-blocking agent and the like. Therefore, additives or substances resulting from the additives do not exude into the contents as fine particles or liquids from the heat seal layer itself, and the contents stored in the packaging bag are altered. There is no. Therefore, the packaging bag of this invention is suitable for packaging bags for products that require cleanliness in the storage of medical supplies, foods, electronic parts, etc., including the second liquid for hair dye. In particular, linear low density polyethylene obtained by a gas phase method using a single site catalyst as a polymerization catalyst is preferable.

In addition, SLLDPE used as a heat seal layer of a laminated film constitutes a special melting point part such as a high melting point part that imparts heat resistance and a low melting point part that contributes to low temperature heat sealability. Compared to LLDPE with Ziegler catalyst as a polymerization catalyst, heat sealability and sealing strength at low temperature are excellent, heat sealing at the time of bag making is easy and economical, and peeling at the heat-sealed part of the bag There is little fear of destruction. In addition, after the contents are stored in the packaging bag of the present invention, when heat-sealing the opening of the bag, heat sealing at a low temperature may be used, and the contents in the heat-sealing may be damaged or altered. There is little fear.
Since the laminated film constituting the bag has a water vapor permeability of 4.5 g / m ² · 24 hr or less and an oxygen gas permeability of 40 cc / m ² · 24 hr or more, for example, the second liquid for hair dye Even if it contains contents that generate gas by decomposition, such as hydrogen peroxide contained in the bag, it can be quickly dissipated out of the bag, preventing the bag from expanding, bursting, and delamination of the film. At the same time, transpiration of water contained in the contents can be reduced. Therefore, an inexpensive laminated film having a desired water vapor permeability and oxygen permeability can be used without using an expensive laminated film in which a silica vapor deposition layer or the like is vapor-deposited on a base material layer. The unit price of the bag can be reduced.

When the intermediate layer is biaxially stretched nylon and the base material layer is biaxially stretched polyester, the thickness of the intermediate layer and the base material layer, the selection of the draw ratio, the combination of orientation directions, and the thickness of the heat seal layer By appropriately setting the thickness and the like, it is easy to set the water vapor permeability to 4.5 g / m ² · 24 hr or less and the oxygen gas permeability to a desired value of 40 cc / m ² · 24 hr or more. It is not necessary to use an expensive film on which a vapor deposition layer is deposited, and is inexpensive. For example, in a bag using PVDC as a gas barrier layer, harmful substances such as chlorine gas are released at the time of combustion disposal, and the burden on the environment is large. However, this laminated film configuration has the advantage that the environmental impact during disposal is small. And by making biaxially stretched nylon as the intermediate layer and biaxially stretched polyester as the base material layer, the strength, puncture resistance, pinhole resistance, fragrance retention, dimensional stability, and printability required for the bag Good characteristics can be obtained.

Further, the heat seal layer and the intermediate layer, and the intermediate layer and the base material layer are dry laminated, so that the water vapor permeability is 4.5 g / m ² · 24 hr or less, and the oxygen gas permeability is 40 cc / m ² · 24 hr or more. Among these conditions, a bag having a predetermined water vapor permeability and oxygen gas permeability can be easily manufactured at low cost.

  And in the packaging bag which accommodates the 2nd liquid for hair dye containing hydrogen peroxide, the content which generate | occur | produces gas by decomposition | disassembly of the hydrogen peroxide contained in the 2nd liquid for hair dye is accommodated. Can quickly dissipate out of the bag, prevent expansion and rupture of the bag, delamination of the film, and less evaporation of moisture contained in the contents from the laminated film, depending on the concentration of the contents, etc. The second liquid is unlikely to deteriorate.

  The best mode for carrying out the invention will be described below, and the present invention will be described in more detail. Of course, the present invention is not limited to the following embodiments.

The SLLDPE used in the heat seal layer of the packaging bag of the present invention is a copolymer of ethylene and an α-olefin having 3 to 20 carbons polymerized by a gas phase method using a single site catalyst as a polymerization catalyst. Linear low density polyethylene is preferred. The density of the SLLDPE is 0.890 to 0.940 g / cm ³ , and among these, 0.890 to 0.930 g / cm ³ is preferable from the viewpoint of heat resistance, heat seal strength, and the like. The melt flow rate is preferably 1 to 50 g / 10 min. Among these SLLDPEs, Harmolex NF544N (trade name) of Nippon Polyethylene Co., Ltd. is based on gas phase polymerization using a single site catalyst and is a copolymer with hexane (C6) as an α-olefin. The film has a density of 0.912 g / cm ³ and a melt flow rate of 3.5 g / 10 min. The film has high strength and low temperature heat sealability, and is an antioxidant, neutralizer, slip agent. It is preferable because it does not contain an antiblocking agent or the like, and the additive or the substance resulting from the additive does not exude into the contents from the heat seal layer itself as fine particles or liquid. .

  As the base material layer of the laminated film, polyamide resin, polyester resin, polypropylene resin or the like can be adopted, and it may be unstretched or uniaxially or biaxially stretched. As the polyamide resin, nylon 6, nylon 66, a copolymer of nylon 6 and nylon 66, a copolymer of nylon 6 and nylon 12, polymetaxylylene adipamide (MXD6), or a mixture of these nylons Can be illustrated. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, copolymerized polyester, and polycarbonate. Of these, biaxially stretched polyester is preferred. The base material layer may be a single layer or a multilayer.

  As the intermediate layer, a polyamide resin, a polyester resin, a polypropylene resin, or the like can be adopted as in the case of the base material layer. The intermediate layer may be unstretched or may be uniaxially or biaxially stretched. Of these, biaxially stretched nylon is preferred. The intermediate layer may be a single layer or a multilayer.

If desired, additives such as a plasticizer, an antioxidant, a stabilizer, an antiblocking agent, an antistatic agent, a dye, a pigment, and inorganic fine particles may be added to the base layer and the intermediate layer.
An overcoat agent may be applied to impart printability to the base material layer and the intermediate layer.

The water vapor permeability of the laminated film of the present invention is based on JIS Z0208, and the oxygen gas permeability is based on JIS K7126. The water vapor permeability of the laminated film is 4.5 g / m ² · 24 hr or less and the oxygen gas permeability is 40 cc / m ² · 24 hr or more, such as hydrogen peroxide contained in the second liquid for hair dye. Even if contents that generate gas due to proper decomposition are stored, they can be quickly dissipated out of the bag, preventing the bag from expanding, rupturing, delamination of the film, and reducing transpiration of the contents. Is possible. When the water vapor transmission rate exceeds 4.5 g / m ² · 24 hr, the water contained in the content is largely evaporated, and the water concentration and the like are less than desired, which is not preferable. If the oxygen gas permeability is less than 40 cc / m ² · 24 hr, it is difficult for gas generated by decomposition to be rapidly diffused out of the bag, causing the bag to expand, rupture, and delamination of the film. It is not preferable.

The laminated film of the present invention can be obtained by a dry laminating method, a non-solvent laminating method, an extrusion laminating method, a wet lamination method, a hot melt lamination method, or the like, or by appropriately combining these laminating methods. At the time of lamination, surface activation treatment such as corona treatment, blast treatment, oxidation treatment, and ozone treatment may be appropriately performed on the film to be each layer. Among these laminating methods, dry lamination is used to achieve a predetermined water vapor permeability and oxygen gas satisfying the conditions that the water vapor permeability is 4.5 g / m ² · 24 hr or less and the oxygen gas permeability is 40 cc / m ² · 24 hr or more. It is preferable because a laminated film having transparency can be easily obtained at low cost. As the adhesive for laminating, urethane adhesive, polyester adhesive, polybutadiene adhesive, and polyolefin adhesive are used.

In this invention, when biaxially stretched polyester (A layer) is used as the base layer, biaxially stretched nylon (B layer) is used as the intermediate layer, and SLLDPE (C layer) is used as the heat seal layer, the thickness of the A layer, stretched By appropriately setting the magnification, the thickness of the B layer, the draw ratio, the combination of the orientation directions of the A layer and the B layer, the thickness of the C layer, and the like, the water vapor transmission rate is 4.5 g / m ² · 24 hr or less, oxygen gas It is easy to set the transmittance to a desired value of 40 cc / m ² · 24 hr or more.

  In a laminated film obtained by dry lamination using biaxially stretched polyester (A layer) as a base material layer, biaxially stretched nylon (B layer) as an intermediate layer, and SLLDPE (C layer) as a heat seal layer, the A layer is 5 to 5 It is preferable that it is 25 micrometers, B layer is 8-25 micrometers, and C layer is 80-250 micrometers. If the A layer is less than 5 μm, the fragrance retention and dimensional stability are not preferable, and if it exceeds 25 μm, the cost is increased and the processability is inferior. If the B layer is 8 μm, the strength, puncture resistance and pinhole resistance are insufficient, which is not preferable. If it exceeds 25 μm, the cost is increased and the workability is inferior. If the C layer is less than 80, it is difficult to obtain sufficient bag sealing strength, and if dropped, it is not preferable because it is easy to break the bag. If it exceeds 250 μm, it takes a long time for heat sealing at the time of bag making, and the production efficiency Decreases, leading to an increase in cost.

FIG. 1 is a cross-sectional view of a laminated film 1 and shows a state where three layers of an A layer 2, a B layer 3, and a C layer 4 are dry laminated.
As shown in FIG. 1, the A layer 2 and the B layer 3 are bonded via an adhesive layer 5, and the B layer 3 and the C layer 4 are bonded via an adhesive layer 6.

  The packaging bag using the laminated film shown in FIG. 1 can be a flat bag, a standing pouch, a side gusset pouch, and the like. What is necessary is just to make it the bag provided with a tool.

  FIG. 2 is an example of a packaging bag 10 using the laminated film 1 shown in FIG. 1, comprising a front film 11 and a back film 12, except for an opening 13 for filling contents, Shown as a sealed flat bag.

  FIG. 3 is another example of the packaging bag 20 using the laminated film 1 shown in FIG. 1, and a bottom film 23 that is folded between the front film 21 and the back film 22 is sandwiched, and the contents are filled. A standing pouch is shown in which the peripheral edge is heat-sealed, except for the opening 24.

  The packaging bag 30 shown in FIG. 4 is a standing pouch, with the left corner cut out obliquely, and a pouring tool 33 is sandwiched between the front film 31 and the back film 32 on the oblique side, and an opening for filling the contents Except 34, it was heat-sealed.

  The packaging bag 40 shown in FIG. 5 is a standing pouch that is heat-sealed except for an opening 44 for filling contents, with a pouring tool 43 sandwiched between a front film 41 and a back film 42 on the upper side thereof. It is.

  The packaging bag shown in FIG. 6 is a side gusset bag 50 with a pouring tool 51. As shown in FIG. 7, the side gusset bag 50 sandwiches a left film 54 and a right film 55 that are mountain-folded from the side between a front film 52 and a back film 53, and a pouring tool 51 from below. It is manufactured by heat sealing except for the opening 56 for filling the contents on the upper side. The side gusset bag 50 is used by filling the contents and then heat-sealing the opening 56 and suspending it using the locking holes 57 and 57.

  Next, an example is shown with a comparative example, and it explains in more detail. Of course, the present invention is not limited to the following examples.

Example 1
A biaxially stretched polyester film with a thickness of 12 μm as a base layer, a biaxially stretched nylon film with a thickness of 15 μm as an intermediate layer, and a SLLDPE (trade name; Harmolex NF544N, Nippon Polyethylene) as a heat seal layer by a gas phase method with a thickness of 180 μm The film was dry-laminated using a urethane adhesive to obtain a laminated film.

The water vapor permeability of the obtained laminated film was measured based on JIS Z0208, and the oxygen gas permeability was measured based on JIS K7126.
As a result, the water vapor permeability was 3.5 g / m ² · 24 hr, and the oxygen gas permeability was 45 cc / m ² · 24 hr.

Using the resulting laminated film, a standing pouch with a polyethylene pouring tool as shown in FIG. 4 was produced. The heat sealing temperature of the standing pouch was 140 ° C. except that the heat sealing temperature of the hypotenuse where the pouring tool was attached was 180 ° C.
A second liquid for commercially available hair dye was poured into the obtained standing pouch, and the opening was heat-sealed at 140 ° C.

A standing pouch filled with the second liquid for hair dye was subjected to an accelerated test for 1 month at 60 ° C. and 75% relative humidity in a thermostatic bath.
The measurement items and test methods evaluated in the accelerated test are as follows.

[Weight loss measurement]
The weight loss relative to the weight at the start of the test was measured.

[Appearance measurement]
The presence or absence of leakage or discoloration was confirmed visually.

[Seal strength]
After 2 weeks from the start of the test, the side seal part of the standing pouch, the bottom seal part, and the seal part of the pouring tool are cut into 15 mm widths each time, and a tensile test is performed at a tensile speed of 300 mm / min using a tensile tester. The seal strength was measured.

[Lamination strength]
At the middle of the front and back films of the standing pouch after two weeks from the start of the test, a test piece with a width of 15 mm is cut off at the approximate center of the front and back films of the standing pouch, and T-type peeled off at a tensile speed of 100 mm / min using a tensile tester. Was measured. The measurement of adhesive strength was performed for each of the TD direction and the MD direction for the base material layer and the intermediate layer, and for the intermediate layer and the heat seal layer.

  In addition, the sealing strength and laminating strength of the standing pouch manufactured (that is, blank) were measured for comparison.

The results of weight loss measurement and appearance measurement are as follows.
Results of weight loss measurement: 1.09% weight loss at the end of 2 weeks and 2.09% weight at the end of 1 month with respect to the weight when the second liquid for hair dye was filled.
Appearance measurement results: No leakage or discoloration was observed even after 2 weeks or 1 month. However, the standing pouch was slightly inflated after one month.

  Table 1 shows the measurement results of the seal strength and the laminate strength.

(Comparative Example 1)
A biaxially stretched polyester film with a thickness of 12 μm as a base layer, a biaxially stretched nylon film with a thickness of 15 μm as an intermediate layer, and a LLDPE (trade name; Moortec, Idemitsu Petroleum) by a commercially available liquid phase method with a thickness of 180 μm as a heat seal layer (Chemical Co., Ltd.) film was dry-laminated using a urethane adhesive to obtain a laminated film.

The water vapor permeability of the obtained laminated film was measured in the same manner as in Example 1. As a result, the water vapor permeability was 4.5 g / m ² · 24 hr, and the oxygen gas permeability was 30 cc / m ² · 24 hr.
Using the obtained laminated film, a standing pouch with a pouring tool as shown in FIG. The heat sealing temperature of the standing pouch was 180 ° C.

  The same second pouch for commercial hair dye as in Example 2 was poured into the resulting standing pouch, and the opening was heat sealed at 180 ° C.

  The standing pouch filled with the second liquid for hair dye was subjected to an accelerated test for 1 month at 60 ° C. and 75% relative humidity in a thermostatic bath in the same manner as in Example 1.

The results of weight loss measurement and appearance measurement are as follows.
Measurement results of weight loss: The weight was reduced by 1.21% when two weeks passed and 2.41% after one month with respect to the weight when the second liquid for hair dye was filled.
Appearance measurement results: No leakage or discoloration was observed at the end of 2 weeks or 1 month, but the standing pouch was slightly expanded at the end of 1 month, and the bottom film indicated by X in FIG. The surface film 31 and the back film 32 are overlapped and heat-sealed in the vicinity of the place where the second liquid for the hair coloring agent is filled and the bottom film spreads into a boat bottom shape. In the upper part of both ends of the bottom film in which the weight of the second liquid for the agent became a boat bottom shape, peeling was observed at the bent portion where the standing pouch was bent (the bent state is not clearly shown in FIG. 4).

  Table 2 shows the measurement results of the seal strength and the laminate strength.

  In addition, various bags were made using the laminated film used in Example 1, and the experiment was conducted by storing medical supplies such as infusions, foods such as liquor, infant milk, and electronic parts in the bags. There was no harmful effect on the contents due to the permeation of water vapor and the permeation of oxygen gas.

It is sectional drawing which shows one Embodiment of the laminated | multilayer film of this invention. It is an example of the packaging bag using the laminated | multilayer film of this invention. It is another example of the packaging bag using the laminated | multilayer film of this invention. It is a further example of a packaging bag using the laminated film of the present invention. It is a further example of a packaging bag using the laminated film of the present invention. It is a further example of a packaging bag using the laminated film of the present invention. It is a disassembled perspective view of the packaging bag shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laminated film 2 A layer 3 B layer 4 C layer 5, 6 Adhesive layer 10, 20, 30, 40, 50 Packaging bag

Claims (4)

A heat-seal layer, an intermediate layer laminated on the heat-seal layer, and a packaging bag formed by heat-sealing the heat-seal layer of the laminated film having a base material layer laminated on the intermediate layer as an innermost layer. ,
The heat seal layer is a linear low density polyethylene using a single site catalyst as a polymerization catalyst,
A packaging bag having a water vapor permeability of 4.5 g / m ² · 24 hr or less and an oxygen gas permeability of 40 cc / m ² · 24 hr or more as the laminated film.   The packaging bag according to claim 1, wherein the intermediate layer is biaxially stretched nylon, and the base material layer is biaxially stretched polyester.   The packaging bag according to claim 1 or 2, wherein the heat seal layer and the intermediate layer, and the intermediate layer and the base material layer are dry-laminated. The packaging bag according to claim 1, 2 or 3, which contains a second liquid for hair dye containing hydrogen peroxide.

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