JP2005289441A - Air cushioning material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air cushioning material which can be discarded by an environmentally-friendly method. <P>SOLUTION: The air cushioning material 1 wherein a gas is sealed in a bag body consisting of a plastic film, is characterized by that the plastic film comprises a biodegradable film made of a biodegradable resin, with a static friction coefficient of 0.50-1.30, and a half-life period of ≤30 sec, and a static cushioning coefficient is ≤8.0 when a compression loading to the air cushioning material is 980 N/piece, and the minimum value of a dynamic cushioning coefficient until the air cushioning material is broken is ≤8.0. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an air cushioning material using gas.

  As an example of a conventional air cushioning material, the following literature 1 discloses a packaging buffer in which two plastic sheets provided with a barrier layer are opposed to each other, and the two sheets are fixed to each other with a gas sealed therebetween. The materials are listed. The portion in which the gas is enclosed is divided into a plurality of gas enclosure division parts by heat sealing. As the material for forming the barrier layer, thermoplastic resins such as polyester resins, polyamide resins, polyvinyl chloride resins, vinylidene chloride resins, and ethylene-vinyl alcohol copolymers are used.

Further, in Patent Document 2 below, two plastic sheets are overlapped, divided into a plurality of areas by an adhesive portion, an area surrounded by the adhesive portion is defined as an air chamber, and air is enclosed in the air chamber. A cushioning material for packing is described. An example of the plastic sheet is a polyethylene biaxially stretched film.
Japanese Patent Laid-Open No. 5-2014473 JP-A-5-4660

Such air cushioning materials are used for packaging and packaging of easily damaged items, etc., but most of the unnecessary air cushioning materials are incinerated or landfilled, which is environmentally unfavorable. There was a problem.
The present invention has been made to solve the above problems, and an object of the present invention is to provide an air cushioning material that can be disposed of in an environmentally favorable manner.

The inventor has paid attention to a biodegradable film as a plastic material for an air cushioning material. However, when an air cushioning material is manufactured by applying an existing biodegradable film to a conventional air cushioning material manufacturing device, the strength of the air cushioning material is greatly insufficient or air leakage easily occurs. Inconvenience occurred. In addition, trouble may occur in the manufacturing apparatus, and even molding may not be possible.
Therefore, as a result of intensive research, a good cushioning material can be obtained by using a biodegradable film that satisfies specific conditions and configuring the air cushioning material so that the static buffer coefficient and the dynamic buffer coefficient satisfy a specific range. The present invention has been completed by finding that an air cushioning material having characteristics can be obtained and manufacturing problems can be solved.

  That is, the air cushioning material of the present invention is an air cushioning material in which a gas is sealed in a bag made of a plastic film, and the plastic film is made of a biodegradable resin and has a static friction coefficient of 0.50 or more and 1 .30 or less, a half-life of 30 seconds or less, and a static buffer coefficient of 8.0 or less when the compression load on the air cushioning material is 980 N / piece, and the air cushioning material is broken. The minimum value of the dynamic buffer coefficient until bagging is 8.0 or less.

The biodegradable resin is preferably an aliphatic polyester resin and / or an aliphatic-aromatic copolyester.
The ratio of the longitudinal breaking strength of the biodegradable film when the breaking strength in the longitudinal direction is 30 N / mm ² or more, the breaking strength in the transverse direction is 30 N / mm ² or more, and the breaking strength in the transverse direction is 1. Is preferably 1.0 or more and 1.3 or less.

The biodegradable film has a longitudinal tear strength of 200 N / mm or more and 400 N / mm or less, a transverse tear strength of 200 N / mm or more and 400 N / mm or less, and a longitudinal tear strength of 1. It is preferable that the ratio of the tear strength in the direction is 0.8 or more and 1.0 or less.
Moreover, the form with which several air shock absorbing material is connected through the perforation along the vertical direction of the said biodegradable film is preferable.

  ADVANTAGE OF THE INVENTION According to this invention, it can consist of a biodegradable film, and can manufacture the air shock absorbing material which has a favorable characteristic, without producing the trouble on manufacture. Since the air cushioning material of the present invention is biodegraded in the soil or in water, it can be disposed of without incineration, which is environmentally preferable.

FIG. 1 is a perspective view showing an embodiment of an air cushioning material of the present invention.
FIG. 1 shows a connecting body 10 in which a plurality of air cushioning materials 1, 1... Are connected to each other through a perforation 2. One air cushioning material 1 has a rectangular biodegradable film (hereinafter also referred to simply as a film) folded in two and overlapped, and air is filled between the upper film 1a and the lower film 1b. In this state, the three open end edges are hermetically closed by heat sealing.
The length direction X of the coupling body 10 is the longitudinal direction of the film (the length direction during film formation). The lateral direction of the film (the width direction during film formation) is indicated by Y.

In the present embodiment, of the four sides forming the periphery of the air cushioning material 1, two short sides are along the X direction, and two long sides are along the Y direction.
One short side is a folded portion 11 where the upper film 1a and the lower film 1b are continuous. On the other short side, a short side heat seal portion 12 extending in the X direction is provided slightly inside the film edge, whereby the upper film 1a and the lower film 1b are airtightly fixed. Between the short side heat seal part 12 and the film edge is a short side binding margin 12a, where the upper film 1a and the lower film 1b are separated from each other.
In addition, long side heat seal portions 13 and 13 along the Y direction are respectively provided on the two long sides, whereby the upper film 1a and the lower film 1b are airtightly fixed. A long side binding margin portion 13a is provided outside the long side heat seal portion 13, and the upper film 1a and the lower film 1b are separated from each other here.
In the connector 10, the long side heat seal portions 13 of the adjacent air cushioning materials 1, 1 are parallel to each other, and the adjacent air cushioning materials 1, 1 are connected to each other via a long side binding margin portion 13 a. The perforation 2 is provided substantially parallel to the long side heat seal portion 13 (along the Y direction) at the approximate center of the long side binding margin portion 13a.

The coupling body 10 of the air cushioning material 1 of the present embodiment can be manufactured, for example, as follows.
First, a biodegradable film having preferable characteristics described later is manufactured. The characteristics of the biodegradable film can be adjusted by changing the composition of the biodegradable resin composition, which is a film material, the conditions during film molding, the thickness of the film, and the like.
The method for producing the biodegradable film is not particularly limited. For example, existing methods such as inflation molding and T-die molding can be used. In particular, the longitudinal and lateral stretching ratios can be set relatively freely. Inflation molding is preferred.
The thickness of the biodegradable film is not particularly limited, but is preferably about 20 μm to 100 μm, more preferably about 30 μm to 80 μm.
A biodegradable film is a core film in a state in which a film formed in a long cylindrical shape is wound around a core material, or a long belt-shaped film is half-folded with a center in the width direction as a fold. It is preferable to use for the buffer material manufacturing process as a film raw material of the form wound up by.

The shock-absorbing material manufacturing process is the heat along the width direction (Y direction) at a predetermined interval in the length direction (X direction) with respect to the half-folded long film or the cylindrical long film. Means for forming the seal portion 13, means for forming the perforation 2 at predetermined intervals in the length direction (X direction), gas in the bag surrounded by the two heat seal portions 13 and the folded portion 11 It can carry out using the bag making machine provided with the means to fill in, and the means to form the heat seal part 12 along a length direction (X direction).
In addition, when a cylindrical long film is used as the raw fabric, means for cutting the vicinity of the folded portion at one end in the width direction (Y direction) should be provided in front of the gas filling means. That's fine.
As such a bag making machine, an existing bag making machine can be applied.

  When using the air cushioning material 1 of the present embodiment, the coupling body 10 is torn by hand and separated by the perforation 2, and the air cushioning material 1 separated one by one or a plurality of air cushioning materials 1 are coupled. It is used in the form of a connector 10 having a desired length.

As a material for forming the biodegradable film in the present invention, a biodegradable resin composition is used. As the biodegradable resin composition, one kind selected from known biodegradable resins such as aliphatic polyester resin, aliphatic-aromatic copolyester, polybutylene succinate, polybutylene adipate, polylactic acid, polycaprolactone, or the like Two or more kinds can be used. These biodegradable resins are available as commercial products. Among these, aliphatic polyester resins, aliphatic-aromatic copolyesters, or mixtures of aliphatic polyester resins and aliphatic-aromatic copolyesters are suitable.
In order to realize desirable characteristics of the air cushioning material 1, it is preferable to use a mixture of two or more biodegradable resins having different compositions.
Moreover, you may make a biodegradable resin composition contain an appropriate additive in the range which does not impair the effect of this invention.

Specific examples of the aliphatic polyester resin include Bionore # 1001, Bionore # 3001, Bionore # 1903, Bionore 2001G, Bionore 5001G (all trade names, Showa Polymer Co., Ltd.) and the like.
Specific examples of the aliphatic-aromatic copolyester include ECOFLEX (trade name, manufactured by BASF).

The biodegradable film used in the present invention has a static friction coefficient of 0.50 to 1.30, preferably 0.60 to 1.20.
The value of the static friction coefficient in this specification is a value obtained by measuring the static friction coefficient when a mirror-finished stainless steel plate slides at a relative speed of 3000 mm / min on a test piece by a method according to ASTM D 1894. .
If the static friction coefficient of the biodegradable film exceeds the above range, there is a risk that the film slips in the apparatus and becomes troubled when the connector 10 is manufactured using a bag making machine. On the other hand, when the coefficient of static friction is smaller than the above range, the films are easily slipped, and winding deviation is likely to occur in the original film. Such unwinding of the original film causes troubles in the bag making machine, and the handleability of the original film itself deteriorates.

The biodegradable film used in the present invention has a half-life of 30 seconds or less, preferably 20 seconds or less.
The half-life value in this specification is a value obtained by measurement by a method according to JIS L 1094. This half-life measurement method is generally a method for measuring the time until the charged voltage is attenuated to 1/2 after the test piece is charged in a corona discharge field.
If the half-life of the biodegradable film exceeds the above range, the films easily adhere to each other due to charging, and the buffer material 1 tends to stay at the discharge port of the bag making machine, causing trouble. Further, dust and dirt are easily adsorbed on the surface of the film and the connecting body 10.

It is preferable that the longitudinal direction of the breaking strength of the biodegradable film is 30 N / mm ² or more, more preferably 40N / mm ² or more. The upper limit value of the breaking strength in the longitudinal direction is not particularly limited, but is generally 100 N / mm ² or less because there is a manufacturing limit.
Breaking strength in the transverse direction of the biodegradable film is preferably 30 N / mm ² or more, more preferably 40N / mm ² or more. The upper limit value of the breaking strength in the transverse direction is not particularly limited, but is generally 100 N / mm ² or less because there is a manufacturing limit.
The ratio of the longitudinal breaking strength when the transverse breaking strength is 1 is preferably 1.0 or more and 1.3 or less, and more preferably 1.2 or less.
The value of the breaking strength in the present specification is a value obtained by measurement under the condition of a tensile speed of 200 mm / min by a method according to JIS K 7161. The test piece is prepared in accordance with JIS K 6734-1995 in the shape of No. 1 dumbbell.
If the breaking strength in the longitudinal direction and the breaking strength in the transverse direction of the biodegradable film are smaller than the above ranges, the strength of the cushioning material 1 is insufficient, and good cushioning characteristics cannot be obtained.
On the other hand, when the ratio of the breaking strength in the vertical direction to the breaking strength in the horizontal direction exceeds the above range, the directionality of the film is too large and the cushioning material 1 is likely to break. On the other hand, if the ratio of the breaking strength is smaller than the above range, the film is not stiff, the film is not smoothly fed in the bag making machine, and it is difficult to discharge the connector 10 from the discharge port. It becomes.

Further, the tear strength in the longitudinal direction of the biodegradable film is preferably 200 N / mm or more and 400 N / mm or less, and more preferably 250 N / mm or more and 350 N / mm or less.
The tear strength in the lateral direction of the biodegradable film is preferably 200 N / mm or more and 400 N / mm or less, more preferably 250 N / mm or more and 350 N / mm or less.
The ratio of the longitudinal tear strength when the transverse tear strength is 1 is preferably 0.80 or more and 1.00 or less, and more preferably 0.80 or more and 0.95 or less.
The value of the tear strength in this specification is a value obtained by measurement under the condition of a tearing speed of 200 mm / min by the right angle method according to JIS K 7128-3.
When the tear strength in the longitudinal direction of the biodegradable film exceeds the above range, the perforation 2 is hardly formed when the connector 10 is manufactured. On the other hand, if it is smaller than the above range, the film is easily torn and the strength of the cushioning material 1 is insufficient.
When the tear strength in the lateral direction of the biodegradable film exceeds the above range, it is difficult to divide the connector 10 at the perforation 2. On the other hand, if it is smaller than the above range, the film is easily torn and the strength of the cushioning material 1 is insufficient. Further, when the connecting body 10 is pulled and divided at the perforation 2, there is a tendency that a part other than the perforation 2 is torn.
If the ratio of the tear strength in the longitudinal direction to the tear strength in the transverse direction exceeds the above range, it is difficult to divide the connector 10 at the perforation 2. On the other hand, when the ratio of the tear strength is smaller than the above range, the directionality of the film is too large, and the cushioning material 1 is likely to be broken.

By forming the buffer material 1 using a biodegradable film having such characteristics, the static buffer coefficient when the compressive load is 980 N / piece is 8.0 or less and the dynamic buffer until the bag is broken A buffer characteristic having a minimum coefficient value of 8.0 or less can be achieved.
A more preferable range of the static buffer coefficient is 7.0 or less. A more preferable range of the dynamic buffer coefficient is 7.0 or less.

  The value of the static buffer coefficient in this specification is a value obtained by a method semi-processed according to JIS Z 0235. As a measuring instrument, a container compression tester (model name: CO-702) manufactured by Tester Sangyo Co., Ltd. is used. The cushioning material 1 as a test piece is formed into a bag having a size of 120 mm in the X direction and a size of 200 mm in the Y direction in the drawing, and uses two cushioning materials 1 connected by a perforation 2 as one set. The value of the static buffer coefficient when the compression speed is 10 mm / min and the compression load is 980 N / piece is obtained.

  The value of the dynamic buffer coefficient in this specification is a value obtained by a method semi-processed according to JIS Z 0235. The measuring instrument is Yoshida Seiki Co., Ltd. (model name: CST-180), and the cushioning material 1 as a test piece is made into a bag having a size of 120 mm in the X direction and 200 mm in the Y direction in the figure. The two cushioning materials 1 connected by the perforation 2 are used as one set. Measurement is performed by dropping the load from a height of 30 cm and increasing the load until the cushioning material 1 is broken.

By configuring the buffer material 1 so that the static buffer coefficient and the dynamic buffer coefficient satisfy the above ranges, the buffer material 1 having good strength and good buffer performance can be obtained.
Specifically, if the static buffer coefficient exceeds the above range, the compression resistance is insufficient, and there is a risk of bag breakage when compressive stress is applied. The lower limit value of the static buffer coefficient is 1, which is the most excellent value as a buffer material, but actual production is difficult, for example, the thickness of the film constituting the buffer material is remarkably increased.
On the other hand, if the dynamic buffer coefficient exceeds the above range, the impact resistance is insufficient and sufficient strength as a buffer material cannot be obtained.
The static buffer coefficient and dynamic buffer coefficient of the cushioning material 1 can be adjusted by changing the characteristics of the biodegradable film, the amount of gas enclosed in the interior, the heat sealing conditions, the size of the cushioned material made in the bag, etc. It is.

According to this embodiment, the buffer material which consists of a biodegradable film and has favorable buffer performance and intensity | strength can be manufactured. Despite the use of a biodegradable film, continuous production is possible using existing bag making machines, and troubles during production can be suppressed, so that the buffer material 1 having biodegradability can be manufactured with high yield. Manufacturing efficiency.
Moreover, even if an antistatic agent is not added to the biodegradable film, good antistatic performance can be obtained. Therefore, it is environmentally preferable when performing disposal processing by biodegradation.

The shape of the cushioning material 1 is not limited to that of the above embodiment, and can be changed as appropriate.
Moreover, in the said embodiment, although the bag body of the shock absorbing material 1 was formed by the three-way seal, it should just be able to form the bag body provided with the space which can hold | maintain gas in short, and according to the structure of the bag making machine to apply, a bag body The shape and the part to be heat sealed can be changed as appropriate.
Moreover, the gas with which the buffer material 1 is filled is not particularly limited as long as it is inert, but air is preferable from the viewpoint of cost.

(Examples 1-3 and Comparative Examples 1-4)
A biodegradable film was prepared by adjusting the blow-up ratio using the inflation method with the formulation shown in Table 1 below (unit: mass%). The thickness of each film was 50 μm.
In Comparative Example 2, the composition was the same as in Example 1, and a film having a balance between the longitudinal and lateral characteristics of the film different from that in Example 1 was produced by changing the blow-up ratio. In Comparative Example 1, polyethylene having no biodegradability (trade name: Novatec LL UF421, manufactured by Nippon Polyethylene Co., Ltd.) was used.

(Film characteristics)
About each biodegradable film obtained by the said Example and comparative example, the breaking strength, tear strength, elongation rate, and tensile elasticity modulus of each of the vertical direction and the horizontal direction were measured. Further, the ratio of the measured values in the vertical direction when the measured value in the horizontal direction was set to 1 was obtained. In addition, the static friction coefficient and half-life of the biodegradable film were measured. The results are shown in Table 1.
The elongation was measured under the condition of a tensile speed of 200 mm / min by a method based on JIS K 7161. In addition, preparation of a test piece makes it a No. 1 dumbbell shape based on JIS K 6734-1995.
The tensile modulus was measured at a tensile test speed of 1 mm / min by a method based on JIS K 7161. The test piece is made into a No. 1 dumbbell shape in accordance with JIS K 6734-1995.

(Buffer material properties)
Using each biodegradable film obtained in the above Examples and Comparative Examples, a connector 10 having the configuration of FIG. 1 was manufactured by a bag making machine (trade name: Air Lady, manufactured by Shirakawa Electric Co., Ltd.).
The size of one buffer material 1 was such that the length in the X direction of the portion filled with gas was 120 mm and the length in the Y direction was 200 mm. The perforation 2 has a shape with a connecting portion of 0.5 mm every 3.0 mm.

  The following evaluation was performed about the malfunction at the time of bag making. That is, when the connector 10 is manufactured, the case where the trouble occurs once per less than 10 cushioning materials is X, the case where the trouble occurs once per 10 or more cushioning materials is less than 30, the trouble is 30 Table 1 shows the case where a coupled body 10 in which one or more cushioning materials 1 are coupled can be manufactured.

About the obtained buffer material 1, the static buffer coefficient and the dynamic buffer coefficient were measured, respectively.
In addition, a puncture test and a separation test from perforations (1) and (2) were performed by the following methods. These results are shown in Table 1.
The static buffer coefficients of Comparative Examples 2 and 3 could not be measured because the bag was broken before the compression load reached 980 N / piece.

In the puncture test, the maximum load value (unit: N) was measured when a puncture needle having a diameter of 1 mm was punctured at a speed of 50 mm / min.
In the separation test (1) from the perforation, the buffer material 1 was separated by tearing the coupling body 10 by hand. Table 1 shows the number of successful separations after 10 times.
In the separation test (2) from the perforation, a test piece obtained by cutting the connecting body 10 to which the two cushioning materials 1 are connected at the position of 20 mm from the perforation centering on the perforation 2 is 500 mm / min. The maximum load value (unit: N) when separated by a tensile tester at a speed of was measured.

It is the perspective view which showed one Embodiment of the shock absorbing material of this invention.

Explanation of symbols

1 ... cushioning material, 2 ... perforation.

Claims (5)

An air cushioning material in which gas is sealed in a bag made of a plastic film,
The plastic film is made of a biodegradable resin composition, is a biodegradable film having a static friction coefficient of 0.50 to 1.30, a half-life of 30 seconds or less, and a compressive load on the air cushioning material of 980 N / An air cushioning material having a static cushioning coefficient of 8.0 or less and a minimum value of a dynamic cushioning coefficient until the air cushioning material is broken is 8.0 or less.   The air buffer material according to claim 1, wherein the biodegradable resin composition comprises an aliphatic polyester resin and / or an aliphatic-aromatic copolyester. The ratio of the longitudinal breaking strength of the biodegradable film when the breaking strength in the longitudinal direction is 30 N / mm ² or more, the breaking strength in the transverse direction is 30 N / mm ² or more, and the breaking strength in the transverse direction is 1. The air cushioning material according to claim 1, wherein the air cushioning material is 1.0 or more and 1.3 or less.   The biodegradable film has a longitudinal tear strength of 200 N / mm or more and 400 N / mm or less, a transverse tear strength of 200 N / mm or more and 400 N / mm or less, and a longitudinal tear strength of 1. The air cushioning material according to any one of claims 1 to 3, wherein the ratio of the tear strength in the direction is 0.8 or more and 1.0 or less. The air cushioning material according to any one of claims 1 to 4, wherein a plurality of air cushioning materials are connected through a perforation along a longitudinal direction of the biodegradable film. .

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