JP2002200709A - Bag-shape article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bag-shape article which is more excellent in the using feeling. SOLUTION: This bag-shape article 20 comprises a laminated body 23 of a non-woven fabric layer 21 made of a synthetic resin, and a film layer 22 made of a thermoplastic resin. In this case, the bag-shape article has a heat- sealing section 25 wherein the film layers 22 made of the thermoplastic resin are heat-sealed with each other. The bending resistance of the heat sealing section 25 is 150 mm or lower, and the thickness T of the heat sealing section 25 is 0.25 mm or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bag-like article comprising a laminate of a synthetic resin nonwoven fabric layer and a thermoplastic resin film layer.

[0002]

BACKGROUND ART In recent years, nonwoven fabrics have been used because of their advantages such as high productivity and soft touch (feel). Such nonwovens are particularly suitable for wet tissues and carpets,
It is used in everyday products such as the so-called disposable body warmer, and often comes into direct contact with the human body. For example, a disposable body warmer is used by holding it in a hand in an outdoor scene or the like, and is a bag-shaped article in which a heating material such as iron powder is stored.
In such a bag-shaped article, an outer peripheral portion of a packaging material formed of a laminate of a nonwoven fabric layer made of a nonwoven fabric and a resin film layer is formed into a bag shape by heat-sealing the resin film layers of the packaging material. Is done.

[0003] In order to secure the same heat sealing property and hot tack property as a packaging material using nylon or polyester as the nonwoven fabric layer as described above, and to reduce costs, a polypropylene spunbond nonwoven fabric layer is used. A packaging material for a disposable body warmer in which a plastic film layer is laminated is known (see JP-A-11-56894).

[0004]

However, such a bag-shaped article has a problem in that the heat-sealed portion is hard, so that the feeling of use is not good.

[0005] Such a problem is not limited to a bag-shaped article for a disposable body warmer, but also applies to a bag-shaped article having a heat seal portion used for other purposes.

[0006] It is an object of the present invention to provide a bag-shaped article which is more excellent in usability.

[0007]

According to the present invention, as a result of diligent research conducted by the present inventors, the feeling of use of a bag-shaped article is less affected by the rigidity of the packaging material itself than the rigidity of the heat-sealed heat-sealed portion. It has been devised based on the finding that it greatly depends on flexibility and thickness. Specifically, the bag-like article according to the present invention is a bag-like article comprising a laminate of a synthetic resin non-woven fabric layer and a thermoplastic resin film layer, wherein the thermoplastic resin film layer The heat-sealed portion has a heat-sealed portion, and the heat-sealed portion has a stiffness of 150 mm or less and a thickness of 0.25 mm or more. Further, it is more preferable that the heat seal portion has a stiffness of 140 mm or less and a thickness of 0.30 mm or more.

For this reason, the rigidity of the heat seal portion is 1
If it exceeds 50 mm, for example, when the bag-shaped article is used in a hand, the heat-sealed portion of the bag-shaped article touches the hand and feels hard, resulting in poor usability. Also, even when the thickness of the heat seal portion is less than 0.25 mm,
For example, when the bag-shaped article is used in a hand, the heat-sealed portion thereof feels hard against the hand, resulting in poor usability.

Therefore, according to the present invention, for example, even when a bag-shaped article is used in a hand, the heat-sealed portion can be used comfortably without feeling hard in the hand. Therefore, the usability is excellent.

The nonwoven fabric used as the nonwoven fabric layer is not particularly limited, and nonwoven fabrics manufactured by various manufacturing methods can be used. For example, known nonwoven fabrics such as spunbonded nonwoven fabric, spunlace nonwoven fabric, hot-air guard nonwoven fabric, hot embossed guard nonwoven fabric, and melt blown nonwoven fabric can be used. Among them, a spunbond nonwoven fabric which is a long fiber is preferable from the viewpoint of strength, productivity and the like. In addition, for example,
A composite nonwoven fabric that combines the spun bond method and the melt blow method may be employed.

Such a spunbonded nonwoven fabric may be manufactured by a predetermined manufacturing method, and is generally manufactured through the steps of spinning, drawing, opening, collecting, and bonding. Further, in the bonding process, the nonwoven web is generally partially fused. Partial fusion refers to joining nonwoven webs together by heat fusion or the like, instead of joining the front surfaces, but partially. For the partial fusion, for example, a method using an embossing roll having dots (points), broken lines, lattice-like and checkerboard-like convex portions can be adopted.

In the present invention, a more optimal spunbonded nonwoven fabric is, for example, one partially fused by the above-mentioned method, and the area ratio of the fused portion is preferably 10 to 30%, more preferably. Is 12 to 20%. If the area ratio of the fused portion is less than 10% of the whole, the texture is improved, but the fluff is likely to occur, and the fibers are liable to fall off. On the other hand, if the area ratio of the fused portion exceeds 30% of the whole, the touch becomes hard and the texture is impaired.

The spunbond nonwoven has a basis weight of 15
It is preferably from g / m ^{2 to} 70 g / m ² . More preferably, the basis weight of the nonwoven fabric is 20 g / m ² or more and 50 g / m ² or less. If the basis weight of the spunbonded nonwoven fabric exceeds 70 g / m ² , the hand becomes too hard to provide a sufficient texture. On the other hand, 15 g / m ²
If less, the strength of the nonwoven fabric will be insufficient.
There is a drawback that sufficient strength cannot be secured as a laminate, and the laminate is easily broken.

Examples of the synthetic resin used for the nonwoven fabric include polyester resins, polyamide resins, polyolefin resins and the like. Among these, polyolefin-based resins are preferred because they are inexpensive and have high heat sealing properties. As the polyolefin-based resin, a homopolymer such as polypropylene or polyethylene, or a copolymer such as an ethylene-α-olefin copolymer or a propylene-α-olefin copolymer can be used. As the copolymer, linear low density polyethylene (LLDPE),
High pressure method LDPE and the like can be mentioned.

Particularly, among the polyolefin resins, a polypropylene resin which is more excellent in mechanical suitability and heat resistance is preferable.

The synthetic resin other than the polyolefin resin includes a polyester resin and a polyamide resin. Examples of the polyester-based resin include homopolyesters such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and polynaphthalene terephthalate, and copolyesters obtained by copolymerizing other components with these as a main component unit, and further, a mixed polyester thereof. Can be mentioned.

As the polyamide resin, nylon 6
(Polycaprolactamide), nylon 6,6 (polyhexamethylene adipamide), nylon 6,10 (polyhexamethylene sebacamide), nylon 11 (polyundecaneamide), nylon 7 (poly-ω-aminoheptane) Acid), nylon 9 (poly-ω-aminononanoic acid), nylon 12 (polylaurinamide) and the like. Among them, nylon 6, nylon 6,6 are preferably used.

The fiber diameter of the synthetic resin used for the non-woven fabric is not particularly limited.
0 μm is preferable, and 5 to 40 μm is more preferable. Further, the synthetic resin used for the nonwoven fabric may contain, for example, an additive such as a pigment.

On the other hand, the thermoplastic resin constituting the thermoplastic resin film layer is not particularly limited, and examples thereof include generally used ethylene-vinyl acetate copolymer resins and ethylene-methacrylic acid copolymer resins. A coalescing resin or the like can be used. However, heat fusion and hot tack,
Those excellent in low-temperature sealability, strength, and the like are preferable. For example, a polyolefin resin that is inexpensive and has excellent heat sealability can be used.

Further, as the polyolefin resin,
Various polyethylene and polypropylene can be adopted,
Among them, linear low-density polyethylene (LLDPE) is preferable in consideration of low-temperature sealing properties and the like. Such a thermoplastic resin film layer is abutted to each other, and the abutted portion is heat-fused by applying heat or the like from the outside to form a bag or the like. The film layer made of a thermoplastic resin may be a single layer of the film layer or a multilayer including the film layer. In this case, it is sufficient that the thermoplastic resin film layers are heat-sealed to each other.

Further, linear low-density polyethylene (LLD)
PE) may be produced using a metallocene-based catalyst. Examples of the metallocene catalyst include a single site catalyst (SSC) and a geometrically constrained catalyst (CG).
C). Specific examples of these metallocene catalysts are described in JP-A-6-192506 and JP-A-7-145.
298, 7-18151, 7-145
No. 272, WO94 / 06859 and catalysts described in JP-A-5-436.
No. 18, No. 5-51414, International Publication WO9
The catalysts described in JP-A-6 / 04317, JP-A-93 / 13140, JP-A-91 / 04255 and JP-A-91 / 04257 can be mentioned.

More specifically, there is a catalyst comprising a transition metal complex having a cyclopentadienyl group, a mono (di, tri, tetra, penta) methylcyclopentadienyl group or an indenyl group. These metallocene-based catalysts,
Usually, an alkylaluminoxane or an ionic compound such as a boron compound is used in combination. An ethylene-α-olefin copolymer having 4 to 18 carbon atoms is preferred.

In the linear low-density polyethylene, the carbon number of 4 to 18 usually used as a comonomer of the copolymer is used.
Examples of the α-olefin include linear α-olefins such as butene-1, pentene-1, hexene-1, octene-1, nonene-1, decene-1, and dodecene-1;
Examples include branched α-olefins such as 3-methylbutene-1 and 4-methylpentene-1.
Particularly, a linear α-olefin having 4 to 10 carbon atoms is preferable.

These α-olefins may be used alone or in combination of two or more. Further, a small amount of a diene component, for example, dicyclopentadiene; ethylidene norbornene; 1,4-hexadiene; 1,9-decadiene; vinyl norbornene may be used in combination.
The content of the α-olefin unit in the ethylene-α-olefin copolymer is not particularly limited, and may be appropriately selected depending on the purpose.

Further, a resin containing a linear low-density polyethylene produced using such a metallocene-based catalyst includes:
Those having a melting point of 70 to 120 ° C are suitable. The temperature is more preferably 85 to 110 ° C. In a bag-like article using a laminate having such a configuration, it is necessary that a film layer made of a resin containing linear low-density polyethylene is laminated as a heat-sealing layer during bag making. In this case, since the heat sealing property is improved, the melting point of the resin containing the linear low-density polyethylene is preferably as low as possible. There is a possibility that the interface is melted and peeled and the bag is broken. When the temperature is higher than 120 ° C., the difference from the melting point of the polypropylene resin used for the nonwoven fabric layer becomes small, and the heat sealability is deteriorated, such as deformation of the nonwoven fabric layer and reduction in stability during high-speed bag-making sealing. There is a risk.

The film layer is to be a heat-sealing layer at the time of bag making. If the melting point satisfies the above range, only the linear low-density polyethylene obtained using a metallocene catalyst can be used. It does not need to be such, and may include a linear low-density polyethylene or a low-density polyethylene obtained by another manufacturing method. That is, a material obtained by blending these other resins with a linear low-density polyethylene obtained using a metallocene catalyst may be used as the material of the film layer. Preferably, only a linear low-density polyethylene obtained using a metallocene catalyst is used.

Further, the film layer made of a thermoplastic resin is
It may be a single layer of the above-mentioned film layer made of a resin containing a linear low-density polyethylene produced using a metallocene catalyst, or a multi-layer in which another thermoplastic resin is laminated on this layer. However, in the case of a multilayer structure, the film layer made of a resin containing a linear low-density polyethylene produced using a metallocene-based catalyst serves as a seal layer to be heat-sealed when making a bag. It is necessary to be.

The thickness of the thermoplastic resin film layer is preferably from 30 to 80 μm, more preferably from 40 to 60 μm.
Is more preferred. If it is less than 30 μm, sufficient piercing strength cannot be obtained, and if it exceeds 80 μm, the heat-fusibility decreases, and high-speed production becomes difficult.

Further, the material for forming the film layer includes:
A third component such as various additives may be added as long as the object of the present invention is not impaired. For example, when air permeability is required for a film for a warmer or the like, a microporous film obtained by adding calcium carbonate to a polyolefin-based resin and stretching the film may be used as the film layer.

The method for laminating the nonwoven fabric layer and the film layer is not particularly limited, and a known method may be used. For example, extrusion lamination to melt-extrude a linear low-density polyethylene produced using a metallocene-based catalyst on a nonwoven fabric, or a resin layer of low-density polyethylene or the like, produced using a nonwoven fabric and a metallocene-based catalyst A polysand laminate in which linear low-density polyethylene is laminated, a dry laminate using a fusing agent, or the like can be used. Furthermore, in high-speed production, tandem molding using two T-die extruders is preferably used.

The bag-making method is not particularly limited, and any known method may be used. Specifically, the bag-making method is used so that the film layers made of resin containing linear low-density polyethylene are directly overlapped. A method of stacking two laminates and heat-sealing the four sides with a heat sealer to form a bag is preferably used. It should be noted that the present invention is not limited to four sides, and may be, for example, three sides or the like.

The bag-like article of the present invention is preferably used in such a manner as to be used in contact with human hands. For example, it can be used as a non-slip bag for sports, such as a so-called warmer, a food packaging bag, a rosin bag, and a pharmaceutical packaging bag. Among these, it is particularly preferable to use it as a warmer. In the case of such an application, since the human hand is one of the most concentrated parts of the human body, it becomes more sensitive to the feeling of use, which is preferable. .

[0033]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a warmer 10 having a bag-shaped article 20 according to the present invention, and FIG. 2 is a plan view of the warmer 10. As shown in FIG.
No. 0 comprises the bag-shaped article 20 and the exothermic composition 30 stored inside the bag-shaped article 20. Such a warmer 10 is intended to keep warm, especially in winter, and is used while being held in a hand.

The bag-shaped article 20 comprises two laminated bodies 23 each having a spunbonded nonwoven fabric layer 21 made of a polyolefin resin and a film layer 22 made of a thermoplastic resin. These two laminates 23, 23 are stacked so that the respective film layers 22, 22 are in contact with each other on the inner side, and the outer peripheral portion is heat-fused by heat from the outside to form a bag shape. Is done.

In the upper laminate 23 in FIG. 1, a plurality of air holes 20A connecting the inside and the outside of the bag-like article 20 are formed. Since air enters the bag-shaped article 20 from the outside to the inside through the ventilation holes 20A, oxygen in the air reacts with iron powder in the exothermic composition to form the exothermic composition 30. It has become feverish. Sufficient air permeability can be ensured by forming, for example, 400 air holes 20A having a hole diameter of 0.1 mm. In addition, the air hole 20A is not limited to these hole diameters and number of holes. Further, the ventilation holes 20A may be formed in the lower laminate 23 in FIG.

On the other hand, as shown in FIG.
Is provided with a bag body 24 in which the exothermic composition 30 is housed and used in contact with human hands, and a heat seal portion 25 which is an outer peripheral portion which is heat-sealed as described above.
The heat seal portion 25 has a thickness T and a width L as shown in FIG.

The warmer 10 having the above structure is manufactured as follows. (Procedure 1) First, a laminate 23 is obtained by extrusion-laminating the nonwoven fabric layer 21 and the film layer 22 using a T-die extrusion laminator. (Procedure 2) A ventilation hole 20A is formed in a part of the laminate 23 using a hot needle to obtain a breathable laminate 23A.

(Procedure 3) The laminate 23 thus obtained and the breathable laminate 23A subjected to ventilation processing are
The film is supplied as a raw material in such a manner that the respective film layers are in contact with each other. (Procedure 4) Thereafter, using a hot roll type packaging and filling sealing machine, while filling the exothermic composition, the laminate 23,
A heat-sealed portion is formed by heat-sealing the four sides of 23A. As described above, the warmer 10 is manufactured.

With respect to the warmer 10 thus obtained, the rigidity and the thickness T of the heat seal portion 25 were measured by the following method, and the usability of the warmer 10 was evaluated. (Measurement method of rigidity) Measurement method: JIS L1096 A method (45 ° cantilever method) Conditions of the object to be measured: Measured with a heat-seal part 5 mm width

(Thickness measuring method) Measuring machine: ABS Digimatic Indicator ID-C
112, manufactured by Mitutoyo Corporation Measurement conditions: measurement terminal; 5 mmφ terminal, pressure condition; 1.2
N or less

(Evaluation method) The feeling of use of the warmer 10 was evaluated by performing a monitor test using a panel of 20 persons (○: good feeling of use, ×: poor feeling of use due to the heat-sealed portion being hard on the hand).

As a result of measurement and evaluation by such a method, the stiffness of the heat seal portion 25 was 150 mm or less, and the thickness T was 0.25 mm or more.

According to the present embodiment, the following effects can be obtained. (Effect 1) The rigidity of the heat seal portion 25 is 150 mm
Since the thickness T is 0.25 mm or more, even when the hand warmer 10 is used in a hand, the heat seal portion 25 does not feel hard in the hand, so that it is comfortable. Can be used for (Effect 2) Since the spunbonded nonwoven fabric 21 is employed as the nonwoven fabric of the nonwoven fabric layer, strength, productivity, and the like can be secured as compared with nonwoven fabrics obtained by other methods.

(Effect 3) Since the polyolefin resin is used as the synthetic resin used for the nonwoven fabric, cost competitiveness can be improved.

It should be noted that the present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved. For example,
Although a spunbonded nonwoven fabric is used as the nonwoven fabric, the present invention is not limited to this, and a nonwoven fabric formed by another method such as a melt blown nonwoven fabric may be used. However, the spunbond nonwoven fabric is
There is an advantage in strength and the like.

In the above-described embodiment, the synthetic resin constituting the nonwoven fabric is a polyolefin resin. However, the present invention is not limited to this, and another synthetic resin such as polyamide may be used. Further, in the above-described embodiment, the touch panel is used so as to be held in the hand of the user. However, for example, the touch panel may be used in contact with a part other than the hand such as a foot. In the above embodiment, the heater was used as the warmer 10, but it may be used for other purposes. In addition, other specific shapes when implementing the present invention,
Modifications are possible as long as the object of the present invention can be achieved.

[0047]

The present invention will now be described more specifically with reference to examples and comparative examples. [Example 1] (A) Nonwoven fabric constituting nonwoven fabric layer: polypropylene spunbonded nonwoven fabric (Stratec RW2040, basis weight 40 g / m ² , melting point 163 ° C, heat fusion area ratio 15%, manufactured by Idemitsu Unitech) (B1) ) Film layer: Linear low-density polyethylene co-extruded cast film (Unilux LS740C, thickness 40 μm, manufactured by Idemitsu Unitech) (C) Low-density polyethylene (Petrocene 205, thickness 1)
5 μm, manufactured by Tosoh Corporation) The nonwoven fabric layer (A) and the film layer (B1) were extruded using a T-die extrusion laminator at an extrusion temperature of 300 ° C.
Extrusion sand lamination with low density polyethylene (C) was performed to obtain a two-layer laminated sheet. Using this two-layer laminated sheet, a warmer was obtained in the same manner as (Procedure 2) to (Procedure 4) of the above-described first embodiment (size: 13.5 cm in length × 1 in width).
0 cm, width L7 mm of the heat seal portion). that time,
The heat sealing was performed at a temperature of 120 ° C.

Example 2 (B2) Resin of Film Layer: Low Density Polyethylene (LD
PE) (NUC polyethylene 8007, melting point 122 ° C,
(B3) Resin of film layer: linear low density polyethylene (LLDPE) (affinity FW1650, melting point 9)
8 ° C., manufactured by Dow Chemical Company) On the nonwoven fabric layer (A) used in Example 1, the film layer (B2) and the film layer (B3) were each 25 μm thick using a two-head T-die extruder. And non-woven fabric layer (A) / LDPE (B2) / LLDPE (B3)
Was obtained. Using this three-layer laminated sheet, a warmer having the same shape was obtained in the same manner as (Procedure 2) to (Procedure 4) of the above-described embodiment. At that time, the heat sealing temperature was set to 130 ° C.

[Comparative Example 1] (B4) Film layer: linear low-density polyethylene (Moirtec 0238CN, melting point 122 ° C, manufactured by Idemitsu Unitech Co.) A film layer was formed on the nonwoven fabric layer (A) used in Example 1 above. (B4) was extrusion-laminated using a T-die type extrusion laminator at an extrusion temperature of 240 ° C. and a thickness of 50 μm to obtain a two-layer laminated sheet. Using this two-layer laminated sheet, a warmer having the same shape was obtained in the same manner as (Procedure 2) to (Procedure 4) of the above-described embodiment. At that time, the heat sealing temperature was set to 140 ° C. or higher.

Comparative Example 2 The heat-sealed portion of the two-layer laminated sheet obtained in Example 1 was heat-sealed again using an impulse sealer (CS-200II, manufactured by Chubu Sogyo Co., Ltd.). I got Cairo.

With respect to the warmers obtained in each of the above Examples and Comparative Examples, the method of measuring rigidity in the above embodiment was as follows.
Measurement and evaluation were performed in the same manner as (thickness measurement method) and (evaluation method). Table 1 summarizes these measurement results and evaluation results.

[0052]

[Table 1]

In each of Example 1 and Example 2, the thickness T is 0.25 mm or more and the stiffness is 150 mm or less.

In Comparative Example 1, the thickness T was 0.25 m
m, but since the stiffness exceeds 150 mm, it can be seen that the usability is poor. On the other hand, in Comparative Example 2, the thickness T is 0.25 mm or less, but since the stiffness is 150 mm or less, it can be seen that the usability is inferior.

[0055]

According to the bag-like article of the present invention, the rigidity of the heat-sealed portion is 150 mm or less and the thickness is 0.25 mm or more. When using the heat seal, the heat seal portion does not touch the hand and does not feel hard, so that it can be used comfortably.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a bag-shaped article according to an embodiment of the present invention.

FIG. 2 is a plan view showing the bag-shaped article of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cairo 20 Bag-shaped article 21 Nonwoven fabric layer 22 Film layer 23 Laminate 25 Heat seal part

 ──────────────────────────────────────────────────の Continuing on the front page F term (reference) 3E064 AA05 BA24 BA30 BA60 BB03 BC18 EA30 FA01 HC01 HN05 4C099 AA01 CA08 EA08 GA03 JA04 LA05 4F100 AK01A AK01B AK06 AK07 AK63 BA02 BA03 BA15 DA01 DB06 J06B DG15B16 E13JBJB13E JK17 JL12B YY00B

Claims (6)

[Claims] 1. A bag-like article comprising a laminate of a synthetic resin non-woven fabric layer and a thermoplastic resin film layer, wherein the thermoplastic resin film layers are heat-sealed to each other. The heat-sealed part has a stiffness of 150 mm or less and a thickness of 0.25 mm or more. 2. The bag-like article according to claim 1, wherein said nonwoven fabric layer is a spunbonded nonwoven fabric layer. 3. The bag-shaped article according to claim 1, wherein the synthetic resin is a polyolefin-based resin. 4. The bag-like article according to claim 3, wherein said polyolefin-based resin is a polypropylene-based resin. 5. The bag-like article according to claim 1, wherein the bag-like article is used in contact with a human hand. 6. The bag-like article according to claim 5, wherein the bag-like article is used as a warmer.