JPH07112736A - Partition material - Google Patents

Abstract

(57) [Summary] (Correction) [Constitution] In a partition material composed of a sheet in which a polyethylene foam sheet 1 is laminated on both sides of a polystyrene foam sheet 2 or a polypropylene foam sheet via an adhesive layer 3, An intermediate partition material, wherein the adhesive layer 3 is formed of an organic solvent-based adhesive obtained by dissolving a mixture of an ethylene-vinyl acetate copolymer resin and a dammar resin in an organic solvent. [Effect] The partitioning material of the present invention has the drawback that the cut surface is still contaminated with an adhesive having stickiness, and the adhesive having stickiness exudes when the surface polyethylene foam is damaged or broken. There is no possibility of causing the drawback of coming. Furthermore, the polyethylene-based foam and the polystyrene-based foam or the polypropylene-based foam are firmly adhered to each other and do not separate during use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partition material used in a box such as a corrugated board, and more specifically, a polystyrene foam sheet or a polypropylene foam sheet is used as a core material of the partition material, and polyethylene is provided on both sides thereof. The present invention relates to an intermediate partition material composed of sheets laminated with a foamed material.

[0002]

BACKGROUND OF THE INVENTION Conventionally, as the partitioning material shown in FIG. 2 is conventionally made of paper such as corrugated board and cardboard, it has no cushioning property and is not packaged for precision parts or machine parts. It has a drawback that the object is easily damaged during transportation. Also, if the partition material is deformed flexibly, the common partition material can be used even if the specifications of the packaged items are slightly different, but the paper partition material such as corrugated board and cardboard does not flexibly deform. , It was necessary to prepare a partitioning material for each different specification of the packaged item, and it was necessary to prepare a very large amount of inventory. Further, since it is made of paper, there is a problem that the object to be packaged is soiled due to the release of paper dust.

On the other hand, it has been attempted to use a foamed plastic sheet as a material for the partitioning material. For example, a polystyrene type foamed sheet or a polypropylene type foamed sheet has been used, but these foams alone are too rigid. Since there is a possibility that the article to be packaged may be damaged due to insufficient flexibility, it has been attempted to use a laminated foam in which a highly flexible foam such as a polyethylene foam sheet is laminated on the surface. However, while the polyethylene foam sheet is highly flexible, it lacks in self-supporting property and adhesiveness, so that when it is bonded to a polystyrene foam sheet or a polypropylene foam sheet using a thermal adhesive such as ethylene-vinyl acetate, the adhesive strength is However, the problem of easy peeling is likely to occur due to insufficient pressure. When a water-based adhesive is used as the adhesive, the water contained in the water-based adhesive is not completely volatilized, and the adhesive is still sticky on the cut surface. The problem was that the water-based adhesive would seep out when it was scratched or torn.

[0004]

Means for Solving the Problems The present invention solves the above-mentioned drawbacks, and comprises a sheet in which a polyethylene foam sheet is laminated on both sides of a polystyrene foam sheet or a polypropylene foam sheet via an adhesive layer. In the partitioning material, an intermediate partitioning material characterized in that the adhesive layer is formed by an organic solvent-based adhesive obtained by dissolving a mixture of ethylene-vinyl acetate copolymer resin and dammar resin in an organic solvent, .

The polyethylene foam sheet used in the present invention is obtained by extruding a melt-kneaded product of a polyethylene resin, a nucleating agent and an expanding agent into a sheet and cooling it.
It is preferable that the expansion ratio is 10 to 60 times and the thickness is 0.5 to 5 mm. If the expansion ratio is more than 60 times, a foam having sufficient strength cannot be obtained, and if the expansion ratio is less than 10 times, sufficient flexibility cannot be obtained, which is not preferable. Further, if the thickness of the polyethylene-based foamed sheet is less than 0.5 mm, a sufficient cushioning effect cannot be obtained as a core material for the partitioning material, which is not preferable, and even if it is greater than 5 mm, further improvement in flexibility and cushioning property cannot be expected. So there is no need for that. The polyethylene resin is a homopolymer of ethylene or a copolymer of ethylene and another monomer. Other monomers include vinyl acetate, propylene, styrene, methyl methacrylate, acrylonitrile, vinyl chloride, butene, butadiene, hexene, methylpentene, octene and the like. Other monomer components can be used in amounts up to 50% by weight. The ethylene homopolymer may be low density polyethylene or high density polyethylene.

The polystyrene-based foamed sheet used in the present invention is called polystyrene paper (PSP) on the market, and a melt-kneaded product of polystyrene-based resin, a nucleating agent and an expanding agent is extruded into a sheet shape. It is obtained by cooling, the expansion ratio is 5 to 30 times, and the thickness is 1 to 7 mm.
Are preferred. If the expansion ratio is greater than 30 times, sufficient independence and strength as a core material for the partitioning material cannot be obtained,
Further, if the expansion ratio is less than 5 times, the lightness and flexibility of the partitioning material are impaired, which is not preferable. When the thickness of the foamed sheet is less than 1 mm, sufficient independence and strength as the core material of the partition material cannot be obtained, and when it is thicker than 7 mm,
This is not preferable because the volume of the partition material itself becomes too large. Examples of the polystyrene resin include styrene homopolymer, styrene / methyl methacrylate copolymer, styrene / α-methylstyrene copolymer, styrene /
An acrylonitrile copolymer, a styrene / acrylic acid copolymer, a styrene / maleic anhydride copolymer, or a mixture of two or more thereof can be used.

The polypropylene-based foamed sheet used in the present invention is obtained by extruding a melt-kneaded product of polypropylene-based resin, a nucleating agent and an expanding agent into a sheet and cooling the same, like the polystyrene-based foamed sheet. Expansion ratio is 2
It is preferably -15 times and has a thickness of 1-10 mm. If the expansion ratio is larger than 15 times, sufficient self-supporting property and strength as the core material of the intermediate partition material cannot be obtained, and if the expansion ratio is less than 2 times, a lightweight intermediate partition material cannot be obtained, which is not preferable.
If the thickness of the foamed sheet is less than 1 mm, sufficient self-supporting property and strength as the core material of the intermediate partition material cannot be obtained, and if it is thicker than 10 mm, the volume of the intermediate partition material itself becomes too large, which is not preferable. As the polypropylene resin, a propylene homopolymer, an ethylene-propylene block copolymer, or the like can be used.

The organic solvent-based adhesive prepared by dissolving the mixture of the ethylene-vinyl acetate copolymer resin and the dammar resin in the organic solvent used in the present invention is a non-volatile component containing the ethylene-vinyl acetate copolymer resin and the dammar resin as the organic solvent. It is preferable that the non-volatile component is 5 to 30 parts by weight with respect to 100 parts by weight of the organic solvent adhesive. By adjusting and using the above non-volatile component in the range of 5 to 30 parts by weight, an organic solvent-based adhesive having an appropriate viscosity can be obtained, so that a uniform and thin non-volatile component layer can be obtained. . Further, by mixing the non-volatile component with the dammar resin, it becomes possible to firmly bond the polyethylene-based foamed sheet without easily peeling it off. The dammar resin is preferably used in the range of 0.5 to 5 parts by weight with respect to 100 parts by weight of the organic solvent adhesive. When the amount of the dammar resin is more than 5 parts by weight, the viscosity of the obtained organic solvent-based adhesive becomes too high, and a uniform and thin nonvolatile component layer cannot be obtained, which is not preferable. Also, if it is less than 0.5 parts by weight, the polyethylene foam sheet is easily peeled off, which is not preferable. If necessary, an additive such as a chlorinated polyolefin such as chlorinated polypropylene or chlorinated polyethylene can be used in the organic solvent-based adhesive.

The organic solvent used in the organic solvent-based adhesive of the present invention is selected to dissolve the mixture of the ethylene-vinyl acetate copolymer resin and the dammar resin and easily volatilize, for example, hydrocarbons. , Halogenated hydrocarbons, alcohols, ethers, esters, and ketones. Examples of hydrocarbons include pentane, hexane, heptane, petroleum ether, petroleum benzine, benzene, toluene, xylene and the like. The halogenated hydrocarbons include chloroform, carbon tetrachloride,
Examples include dichloroethane, trichloroethylene, monochlorobenzene and the like. Examples of alcohols and ethers include methanol, ethanol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, ethyl ether, isopropyl ether,
Examples thereof include dioxane, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether and the like. Examples of the esters include ethyl acetate, isopropyl acetate, butyl acetate, ethylene glycol monoacetate, ethylene glycol monoethyl ether acetate and the like. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

A sheet in which a polyethylene foam sheet is laminated on both sides of a polystyrene foam sheet or a polypropylene foam sheet used in the present invention with an adhesive layer interposed therebetween is ethylene-vinyl acetate copolymerized on one side of the polyethylene foam sheet. After applying an organic solvent-based adhesive in which a mixture of resin and dammar resin is dissolved in an organic solvent and heating to volatilize the organic solvent, the foamed sheet to be used is maintained in a heating atmosphere at a temperature below the softening point. , Or let it pass
It can be obtained by laminating and pressing the polyethylene foam sheet on both sides of a polystyrene foam sheet or a polypropylene foam sheet so as to be in contact with the adhesive layer.

In the present invention, as the adhesive layer, an organic solvent-based adhesive prepared by dissolving a mixture of ethylene-vinyl acetate copolymer resin and dammar resin in an organic solvent is used. Therefore, a uniform and thin adhesive layer is formed on the surface of the polyethylene foam. Can be formed. Further, in order to obtain a uniform and thin adhesive layer, a spraying method or a roll coater method is preferably used as a coating method. After that, since the organic solvent can be easily volatilized, the formed uniform and thin adhesive layer has no tackiness. Furthermore, since the foamed sheet to be used is bonded in a heating atmosphere where the temperature is maintained at a temperature below the softening point, or by passing it and pressing it, it is still adhesive from the cut surface when used as a partitioning material. There is no possibility of causing a defect of being soiled by the agent or a defect of causing an adhesive having tackiness to exude when the polyethylene foam of the surface layer is damaged or broken. Furthermore,
Since the organic solvent-based adhesive used in the present invention is mixed with the ethylene-vinyl acetate copolymer resin and the dammar resin, the polyethylene-based foam sheet and the polystyrene-based foam sheet or the polypropylene-based foam sheet are firmly bonded to each other. Can be obtained.

The partitioning material of the present invention comprises an organic solvent-based adhesive obtained by dissolving a mixture of the ethylene-vinyl acetate copolymer resin and the dammar resin in an organic solvent on both sides of a polystyrene-based foamed sheet or a polypropylene-based foamed sheet. Since it has a structure in which polyethylene foam sheets are laminated for use in, it has excellent flexibility and can be flexibly deformed even if the shape of the packaged item such as precision parts or machine parts is slightly different due to specification changes, It has an advantage that many types of partitioning materials can be dealt with without preparing them as an inventory as in the past. In addition, since the polyethylene foam having excellent cushioning properties is laminated on the surface of the partition material, it has excellent cushioning properties and can be transported without damaging the object to be packaged.

[0013]

EXAMPLES Examples of the present invention will be described below. The peel strength was measured by a method according to JIS-K6301, and the width of the test piece was 25 mm. Example 1 As a polyethylene foam sheet, a mixture of ethylene-vinyl acetate copolymer resin and dammar resin was organically formed on one side of a trade name: Literon S (manufactured by Sekisui Plastics Co., Ltd.) having a thickness of about 1 mm and an expansion ratio of 20 times. Trade name: heat seal varnish PCX-1 as an organic solvent adhesive dissolved in a solvent
00N (manufactured by Daito Kasei Kogyo Co., Ltd.) was applied by spraying so as to be 20 g per 1 m 2 of the polyethylene foam sheet, and the organic solvent was volatilized by blowing air. The polyethylene foam sheet thus obtained was laminated on both sides of the polystyrene foam sheet so as to be in contact with the adhesive layer, and the polyethylene foam sheet of about 2 kg / cm 2 was passed through a heating furnace set to an ambient temperature of 120 ° C. It was adhered by roll compression with pressure to obtain a laminated sheet of FIG. Here, as the polystyrene-based foamed sheet, an Eslen sheet (made by Sekisui Plastics Co., Ltd.) having a thickness of about 2 mm and an expansion ratio of 15 was used. When the peel strength between the polyethylene foam sheet and the polystyrene foam sheet of the obtained laminated sheet was measured, it was not adhered because it was firmly bonded, and the polyethylene foam sheet of the surface layer caused material destruction and could not be measured. It was The obtained laminated sheet was punched with a Thomson blade to obtain a partitioning material as shown in Fig. 2. No cutting chips were generated on the cut surface, and when it was used for transporting precision parts, it was It could be used satisfactorily without dirt or damage to precision parts.

Example 2 A polyethylene foam sheet having a thickness of about 2 mm and a foaming ratio of 30 times: Trade name: Literon S (manufactured by Sekisui Plastics Co., Ltd.) was coated with ethylene-vinyl acetate copolymer resin and dammar resin. Trade name: heat seal varnish PCX-1 as an organic solvent-based adhesive obtained by dissolving the mixture in an organic solvent
00N (manufactured by Daito Kasei Kogyo Co., Ltd.) was applied at 25 g per 1 m 2 of the polyethylene foam using a roll coater, and the organic solvent was volatilized by blowing air. The polyethylene foam sheet thus obtained was laminated on both sides of the polypropylene foam sheet so as to be in contact with the adhesive layer, and was passed through a heating furnace set at an ambient temperature of 140 ° C. to about 1.5 kg / Roll-compression was performed at a pressure of cm 2 to bond the layers to obtain a laminated sheet. Here, the polyethylene foam sheet has a thickness of about 2 mm and a foaming ratio of 5
Double trademark name: Neomicrolen (manufactured by Sekisui Plastics Co., Ltd.) was used. When the peel strength between the polyethylene foam sheet and the polypropylene foam sheet of the obtained laminated sheet was measured, it was not adhered because it was firmly adhered, and the polyethylene foam sheet of the surface layer caused material destruction and could not be measured. It was The obtained laminated sheet was used to obtain a partition material in the same manner as in Example 1. However, no cutting powder was generated on the cut surface, and when it was used for transportation of precision parts, it was stained by an adhesive. It could be used satisfactorily without any damage to precision parts.

COMPARATIVE EXAMPLE 1 A polyethylene foam sheet having a thickness of about 1 mm and a foaming ratio of 20 times is provided on one side of a name: Literon S (manufactured by Sekisui Plastics Co., Ltd.), and as a water-based adhesive, a name of Esdyne 7110 ( Sekisui Chemical Co., Ltd.) was coated with a roll coater so that the polyethylene foam had a weight of 30 g per 1 m 2, and then laminated on both surfaces of the polystyrene foam sheet so as to be in contact with the surface coated with the adhesive, and then about 2 k
The laminate was bonded by roll compression at a pressure of g / cm2 to obtain a laminated sheet. Here, as the polystyrene-based foamed sheet, an Eslen sheet (made by Sekisui Plastics Co., Ltd.) having a thickness of about 2 mm and an expansion ratio of 15 was used. When the peel strength between the polyethylene foam sheet and the polystyrene foam sheet of the obtained laminated sheet was measured, the peel load was 0.85 Kgf, and the polyethylene foam sheet of the surface layer peeled without causing material destruction. . When the obtained laminated sheet was used as a partitioning material for transporting precision parts in the same manner as in Example 1, the adhesive exuded from the cross section and part of the precision parts was soiled.

[0016]

The partitioning material of the present invention is an organic compound obtained by dissolving a mixture of ethylene-vinyl acetate copolymer resin and dammar resin in an organic solvent as an adhesive layer between a polyethylene foam sheet and a polystyrene foam sheet or a polypropylene foam sheet. Since a solvent-based adhesive is used, when it is used as a partitioning material, the cut surface is still contaminated by the adhesive adhesive, and the polyethylene foam sheet of the surface layer is damaged or broken. There is no possibility of causing the defect that the adhesive having tackiness oozes out. Furthermore, since the organic solvent-based adhesive used in the present invention is mixed with the ethylene-vinyl acetate copolymer resin and the dammar resin, the polyethylene foam sheet and the polystyrene foam sheet or the polypropylene foam sheet are firmly bonded. It does not peel off during use.

The partitioning material of the present invention is an organic solvent adhesive obtained by dissolving the mixture of the ethylene-vinyl acetate copolymer resin and the dammar resin in an organic solvent on both sides of a polystyrene foam sheet or a polypropylene foam sheet. Since it has a structure in which polyethylene foam sheets are laminated by using it, it has excellent flexibility and can be flexibly deformed even if the shape of objects to be packaged such as precision parts and machine parts is slightly different due to specification changes. However, it is not necessary to prepare many kinds of partitioning materials as an inventory as in the past. Also,
Since the polyethylene foam sheet having excellent cushioning property is laminated on the surface of the partition material, it has excellent cushioning property and can be transported without damaging the packaged object.

[Brief description of drawings]

FIG. 1 Cross-sectional view of laminated sheet

[Fig. 2] Perspective view of partition material

[Explanation of symbols]

 1. Polyethylene foam sheet 2. Polystyrene foam sheet 3. Adhesive layer

Claims (1)

[Claims] 1. A partition material comprising a sheet in which a polyethylene foam sheet is laminated on both sides of a polystyrene foam sheet or a polypropylene foam sheet with an adhesive layer in between, the adhesive layer comprising an ethylene-vinyl acetate copolymer resin. An intermediate partition material formed by an organic solvent-based adhesive obtained by dissolving a mixture of dammar resins in an organic solvent.