JPH0311987B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an article package, and more particularly to an article package that can effectively protect home appliances, office equipment, furniture, etc. from scratches and damage during storage and transportation. [Prior art and problems to be solved by the invention] Conventionally, it has been used to prevent scratches and damage during storage and transportation of home appliances such as televisions and audio equipment, as well as office equipment, precision equipment, furniture, and other items. In order to
It is packed in an outer case such as a wooden frame. In this case, the item is usually wrapped in a low-density polyethylene film, etc. in advance to prevent moisture and dirt from adhering to the exterior material or dirt caused by dirt or dust from outside. A commonly used method is to use a cardboard case, a wooden frame, a band, or the like to secure the device through a cushioning material. However, although this method can initially prevent moisture and dust from adhering to the product, friction between the packaging film and the product during transportation and handling can damage the product's surface, cause paint or plating to peel off, and reduce the commercial value of the product. There were problems such as lowering the performance. In order to solve this problem, a method is used in which the article is wrapped in a heat-shrinkable film, heat-shrink-wrapped, and then placed in an outer case via a cushioning material. A method using a multilayer sheet made by laminating a foamed polyolefin sheet and a high-density polyethylene film has been proposed and put into practical use. However, this method not only requires a heat-shrinkable film but also a heat tunnel for shrinking, which has the drawback of requiring large equipment, installation space, and electricity consumption, increasing the total packaging cost. In addition, with this method, the multilayer sheet becomes expensive due to the lamination process and sheet thickness, and the thickness of the foam sheet is usually 500 to 600 μm, making it difficult to manufacture, store, and transport the multilayer sheet in terms of bulk, handling, and cost. It also has the drawback of increasing packaging costs, and a solution to this problem is strongly desired. On the other hand, the present applicant has proposed packaging an article with the surface of a thermoplastic resin film having a larger friction coefficient on the inside, which has different friction coefficients between the front and back surfaces, and then arranging a cushioning member on the outside. We have already proposed ways to package goods. (Unexamined Japanese Patent Publication No. 61-127463
issue). However, simply making the friction coefficients of the two outer layers different is not necessarily sufficient, and it is difficult to completely protect household appliances that have transparent resin parts during storage and transportation, and scratches may occur. There was a problem that it could not be put into practical use. It is an object of the present invention to solve the above-mentioned conventional problems and to provide an inexpensive article packaging body that provides good protection for articles, has sufficient strength even with a thin wall, and has an excellent appearance. It is something. [Means for Solving the Problems] That is, the present invention provides a packaged article consisting of (A) a low-density polyethylene resin layer, (B) a foamed polyolefin resin layer, and (C) a high-density polyethylene resin layer. The object of the present invention is to provide an article package in which a multilayer film is packaged with the low density polyethylene resin layer side facing inside and fixed with a cushioning member. The present invention consists of (A) a low-density polyethylene resin layer, (B) a foamed polyolefin resin layer, and (C) a high-density polyethylene resin layer, which have different physical properties such as the coefficient of friction on the inner and outer surfaces, and have intermediate foamed A multilayer film is used. Here, the low density polyethylene resin forming layer A has a density of 0.900 to 0.940 g/cm ³ , a melt index (MI) of 0.1 to 50 g/10 min, preferably a density of 0.905 to 0.935 g/cm ³ , and an MI of 0.2. ~30g/10min, particularly preferably density 0.910~0.930g/ ^cm3 , MI0.3~
20g/10 minutes is used. Low-density polyethylene resins include high-pressure low-density polyethylene (LDPE), ethylene and propylene obtained by medium and low pressure methods, butene-1,4-methylpentene-1,
Copolymers with α-olefins having 3 to 12 carbon atoms such as octene-1, so-called linear low-density polyethylene (LLDPE), ethylene and aromatic olefins,
Acrylic acid esters, copolymers with vinyl monomers such as vinyl acetate, etc., or mixtures thereof are used. Among these, ethylene-vinyl acetate copolymers or mixtures of ethylene-vinyl acetate copolymers and 50% by weight or less of LDPE, LLDPE, ionomers, etc. are particularly preferred. Here, the ethylene-vinyl acetate copolymer (EVA) has a vinyl acetate content of 5 to 35% by weight, preferably 7 to 30% by weight, a density of 0.920 to 0.940 g/cm ³ , and an MI of 0.5.
The use of ~20g/10 minutes is preferred. By selecting this, it is possible to sufficiently protect articles that are particularly susceptible to scratches, such as resin transparent parts of household electrical appliances. This low-density polyethylene resin may have a low crystalline or amorphous density of 0.850 to 0.895, if necessary.
g/cm ³ of erylene-propylene copolymer, ethylene-butene-1 copolymer, petroleum resin, terpene-phenol resin, etc. can also be blended in an amount of 30% by weight or less. This low-density polyethylene resin layer imparts slip resistance and flexibility to the multilayer film, is used on the surface that comes into contact with the packaged article, and plays an important role in protecting the packaged article. Furthermore, this low-density polyethylene resin layer improves foaming of the intermediate layer and also improves film moldability, particularly blown film moldability. The static friction coefficient of the surface of this low-density polyethylene resin layer is usually 0.4 or more,
It is preferably 0.5 or more, more preferably 0.6 or more. The coefficient of static friction in this case indicates the coefficient of static friction between the surfaces of the low-density polyethylene resin layer (measured according to ASTM D-1894). Layer B, ie, the middle layer of the multilayer film, is formed from a polyolefin resin foam layer.
Here, polyolefin resins include polyethylene resins such as high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and ethylene-unsaturated carboxylic acid copolymers, as well as polypropylene, such as polybutene, and even these and other α
-Copolymers with olefins and mixtures thereof may be mentioned. Among these, polyethylene resins are preferred as polyolefin resins, and low density polyethylene and linear low density polyethylene are particularly preferred. Here, the linear low density polyethylene is a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms, such as propylene, butene-1,4-methylpentene-1, octene-1, and the like. These low-density polyethylenes and linear low-density polyethylenes have a density of 0.900 to 0.940.
g/ ^cm3 , melt index (MI) 0.1~50g/
10 minutes, preferably density 0.910-0.930g/ ^cm3 ,
An MI of 0.2 to 20 g/10 minutes is used. In addition,
It is also possible to mix 50% by weight or less of an elastomer or other resin into these polyolefin resins. Furthermore, if necessary, up to 50% by weight of inorganic fillers such as calcium carbonate, talc, clay, etc.
It is also possible to blend kaolin, titanium oxide, zeolite, etc. The foaming agents that can be used to form the polyolefin resin foam layer can be broadly classified into chemical foaming agents and physical foaming agents based on their foaming mechanism. Among these, chemical blowing agents include azodicarbonamide, metal salts of azodicarbonamide, hydrazodicarbonamide, p-toluenesulfonyl hydrazide, dinitropentamethylenetetramine, azodiisobutyronitrile, etc.
Physical blowing agents include butane, heptane, hexane, dichlorodifluoromethane, nitrogen, carbon dioxide gas, and the like. In this polyolefin resin foam layer, there is no particular restriction on the blending ratio of the raw material polyolefin resin and the blowing agent, and it varies depending on the type of blowing agent, etc., but the foaming ratio is 1.2 to 5 times, usually 1.5 to 3 times. It should be set so that This polyolefin resin foam layer preferably has small cell diameters. Further, if necessary, inorganic fine powder or metal salts of higher fatty acids can be appropriately added as a cell nucleating agent to the foamed polyolefin resin layer. Examples of metal salts of higher fatty acids include sodium stearate, calcium stearate, and magnesium stearate.
Foaming can be made uniform by adding ~1% by weight. This polyolefin resin foam layer plays the role of making the multilayer film opaque and giving it a pearl-like appearance, as well as providing cushioning properties to the multilayer film. Furthermore, the high density polyethylene resin forming layer C has a density of 0.945 to 0.975 g/cm ³ and an MI of 0.01 to 5.
g/10 min, preferably density 0.947-0.970 g/cm ³ ,
An MI of 0.02 to 2 g/10 min is used. The high-density polyethylene resin may be a homopolymer of ethylene or a copolymer with other α-olefins such as propene and butene-1.
In addition, as the high-density polyethylene resin, low-density polyethylene or low-crystalline or amorphous ethylene with a density of 0.850 to 0.895 g/cm ³ may be used in a proportion of 50% by weight or less without impairing the slipperiness of the present invention. A proprene copolymer or an ethylene-butene-1 copolymer may also be added. This high-density polyethylene resin layer imparts slipperiness and strength to the multilayer film, and is used as the outer surface when packaging articles, and when the package vibrates, the vibration is transferred between the outer surface of the film and the cushioning member. It acts to protect the article by absorbing it by sliding against the cushioning member and preventing the article from directly rubbing against the cushioning member. Therefore, the coefficient of static friction is usually 0.35 or less, preferably 0.3 or less. Further, this high-density polyethylene resin layer improves foaming of the intermediate layer and improves moldability of the multilayer film. In addition, instead of this high-density polyethylene resin layer, it is possible to use low-density polyethylene with a slip agent added, but in reality, the slip agent would migrate to the middle foam layer, making it slippery. Can't get to the surface. The multilayer film used in the present invention is composed of three layers as described above, and the article to be packaged is packaged with the layer A on the inside. Here, the thickness of the multilayer film is usually 30 to 300μ, particularly 40 to 200μ.
The layer ratio of each layer is Layer A: Layer B: Layer C = 5 to 60:
The ratio is preferably 10-90:5-70, particularly 10-40:20-80:10-50. In addition, since it is difficult to measure the thickness of the foamed film, the layer ratio in this case is shown as the usage ratio of the raw material resin when the intermediate layer is not foamed. Such a multilayer film of the present invention can be produced, for example, by coextrusion inflation molding or T-die coextrusion. In the case of coextrusion inflation molding, the raw material resins are sufficiently melted and kneaded using each extruder, and then adhesively coextruded in a die with a low density polyethylene resin as the outer layer to form a coextruded cylindrical film. This can also be opened to make a flat film. In this case, the die temperature is usually 130~
The temperature is 180°C, the die lip gap is 0.5 to 2.0 mm, and the blow ratio is 1.5 to 5.0. According to this coextrusion inflation molding, the foaming agent-containing resin layer is completely wrapped in the resin layers A and C, so foaming is good, and there is no problem such as eye stains etc. adhering to the die, so it is stable for a long time. Since a multilayer film can be obtained by doing this, it is particularly preferable as a method for producing a multilayer film of the present invention. In addition, in the case of T-die coextrusion, layer A and layer C have a polyolefin resin foam layer (layer B) as an intermediate layer.
It is preferable to use a so-called enveloping type die that encloses the material. The article packaging body of the present invention is made by wrapping the article to be packaged with the low-density polyethylene resin layer side of the above-mentioned multilayer film inside, and fixing the packaged article with a cushioning member. There are no particular restrictions on the items to be packaged, but
Home appliances that require protection from scratches and damage;
Office equipment, precision equipment, furniture, etc. are particularly suitable.
The article to be packaged may be packaged by using a bag-like film as the multilayer film or by wrapping it in a flat film. Examples of the cushioning member used for fixing the packaged article after packaging include resin foams such as polystyrene foam and polyolefin foam, and cardboard. FIG. 1 is a perspective view showing one embodiment of the article packaging body of the present invention. The article packaging body 1 of the present invention is made by wrapping the packaged article 3 with the multilayer film 2 as described above, and fitting and fixing the cushioning member 4 to the packaged article. It may be stored in the case 5 or fixed with a wooden frame, band, adhesive tape, or the like. [Examples] Next, examples of the present invention will be described, but the present invention is not limited thereto unless it exceeds the scope of the present invention. Examples 1 to 5 The resins shown in Table 1 were melt-kneaded using three extrusion molding machines, introduced into an in-die adhesive type circular die and coextruded, and inflation molded at a blow ratio of 3 to form intermediate layer B. A foamed three-layer cylindrical film was obtained. Note that 4 parts by weight of an azodicarbonamide foaming agent masterbatch was added to the intermediate layer B. Table 1 shows the layer ratio of the film calculated from the raw material in which the intermediate layer B is in an unfoamed state. Similarly, the thickness of the film calculated from the raw material in which the intermediate layer B is in an unfoamed state is 60 μm. The intermediate foamed layer of the obtained multilayer film had a foaming ratio of 1.8 to 2.2 and a total thickness of about 80 μm. Table 1 shows the results of measuring the physical properties of the obtained film. Next, this film is cut open, and electrical equipment (with a transparent polycarbonate plate surface) is packaged with the low-density polyethylene resin layer side of outer layer A inside. After being fixed with a cushioning member, it is packed in a cardboard box and placed in a vibration tester. (Shin Nippon Sokki F-800) vibration condition 30Hz,
It was vibrated at 7G for 15 minutes, and the occurrence of scratches on the surface of the transparent polycarbonate plate was observed and evaluated according to the following criteria. The results of this vibration test are shown in Table 1. ◎: No scratches ○: Almost no scratches △: Many dotted scratches occurred ×: Many large dotted scratches occurred Comparative Example 1 Performed according to Example 1 except that low-density polyethylene resin containing a slip agent was used as the inner layer resin. Summer. The results are shown in Table 1. Comparative Example 2 Example 1 was followed except that no blowing agent was added to the intermediate layer. The results are shown in Table 1. Reference Example Table 1 shows the physical property measurement results and vibration test results for a commercially available laminate film (a laminate film of a low-density polyethylene foam film with a thickness of 500μ and a high-density polyethylene with a thickness of 13μ).

[Table] [Operations and Effects of the Invention] Since the article packaging body of the present invention adopts the above-mentioned configuration, the article is well protected during storage and transportation, and it is possible to protect the article from scratches easily. can be effectively protected. That is, the multilayer film used in the article packaging of the present invention has excellent tensile breaking load, Elmendorff tensile strength, and film impact strength. Moreover, in the present invention, by using a layer A having a coefficient of static friction larger than that of layer C, there is less slippage between the packaged article and the packaging film, while the packaging film and the cushioning member are more likely to slip. Therefore, there is no rubbing between the packaging film and the packaged product, which is generally made of a hard material, but rather, the packaging film and the packaged product are fixed, and the cushioning member and the packaging film, which are made of an extremely soft material, do not rub against each other. easily causes slippage. Therefore, there is no risk of damage to the film, and there is no possibility of damage to the packaged article or peeling of the coating due to friction between the film and the packaged article, and the packaged article can be effectively protected. Further, in the article packaging body of the present invention, the multilayer film used can be made thin, and even a thin film of 50 to 100 μm has sufficient strength and protective performance. Therefore, the workability is high, and the film does not take up much bulk during storage and transportation, making it possible to reduce the total packaging cost and save resources. Furthermore, unlike conventional shrink packaging, special equipment is not required, and the packaging operation is extremely simple. Furthermore, the multilayer film used in the present invention has good surface printability, and has a pearl-like luster and a high-quality appearance with a Japanese paper feel, and can be made into a beautiful package. Furthermore, since the multilayer film in the article packaging body of the present invention can be easily obtained in various sizes, it is not limited by the size and shape of the article. Therefore, the article packaging body of the present invention can be used for home appliances,
It can be effectively used as packaging for various items including office equipment, precision equipment, furniture, etc.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the article packaging body of the present invention. 1... Goods packaging body, 2... Multilayer film, 3...
...Packaged article, 4...Buffer member, 5...Outer case.

Claims (1)

[Scope of Claims] 1. An article to be packaged is a low-density polyethylene resin of a multilayer film consisting of (A) a low-density polyethylene resin layer, (B) a foamed polyolefin resin layer, and (C) a high-density polyethylene resin layer. An article package that is wrapped with the layer side inside and fixed with a cushioning member. 2. The article packaging according to claim 1, wherein the low density polyethylene resin is an ethylene-vinyl acetate copolymer. 3. The article packaging according to claim 1, wherein the polyolefin resin foam layer is a low density polyethylene resin foam layer.