JPH0547075Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of technology] This invention is a container for storing, organizing, moving, and transporting mechanical parts incorporating semiconductors such as ICs and LSIs, or electronic parts such as electronic devices. The present invention relates to partitioning materials, and more particularly to partitioning materials that can suppress malfunctions and troubles in electronic components such as semiconductor products and semiconductor equipment caused by static electricity.

[Prior art]

In recent years, the electronics industry has developed rapidly, and many mechanical parts and electronic devices incorporating semiconductor integrated circuits such as ICs and LSIs are being produced. By the way, the circuits of such semiconductor products are delicate and arranged at minute intervals, so a current that exceeds the allowable current, such as static electricity with a strong current, may be applied to integrated circuits such as ICs and LSIs that are energized inside the semiconductor. Malfunctions or troubles occur.

To deal with these problems, conductive sheets have traditionally been used as partitions in containers and packaging materials for storing, organizing, and transporting electronic parts, such as mechanical parts and electronic devices that incorporate semiconductors. ing.

Examples of such partition materials include (1) polyethylene resin foam with a conductive layer on top; (2)
A conductive layer on top of polystyrene foam,
(3) Examples include paper core material with polyethylene resin foam on both sides, and a conductive layer such as aluminum foil on the foam, but the polyethylene resin foam of (1) Those mainly composed of polystyrene foam have poor shape retention, and those mainly composed of (2) polystyrene foam break easily and generate powder, which adheres to the product and reduces its commercial value. There is a drawback. In addition, since the core material of the partition material (3) is paper,
It has the disadvantage that it has low durability and cannot be cleaned if it becomes dirty.

〔the purpose〕

Unlike the conventional partition materials mentioned above, the present invention has excellent breaking strength, does not generate powder, has good shape retention, and can be easily cleaned when soiled, allowing for repeated use. The purpose of the present invention is to provide a partition material that is durable enough to withstand.

〔composition〕

According to the present invention, in the partition material made of an electrically conductive sheet in which a thermoplastic resin sheet containing a conductive material is provided on at least one side of a foamed polystyrene resin sheet having an expansion ratio of 5 to 40 times, the foamed polystyrene The bending elastic modulus of the resin sheet is 3 to 50.
Kg/cm ² is provided.

The partition material A of the present invention will be described with reference to the attached drawings.As shown in FIG. 1, its front shape is as shown in FIG. is provided at the desired position. The fitting groove 4 is formed by punching using a single-edged wooden cutting die or a male and female double-edged cutting die.

As shown in FIGS. 2 and 3, the structure of the conductive sheet 3 constituting the partition material A has a bending elastic modulus (measured according to JIS K9511) of 3 to 50 kg/cm ² , preferably 5 to 30 kg/cm 2 The thermoplastic resin sheet 2 containing a conductive material is laminated on one or both sides of a foamed polystyrene resin sheet 1 having an expansion ratio of ² to 40 times.

That is, the expanded polystyrene resin sheet 1 used in the present invention has an expansion ratio of 5 to 40 times and is JIS
Flexural modulus measured by K9511 is 3-50
Kg/cm ² , preferably 3 to 30 Kg/cm ² .

The expanded polystyrene resin sheet 1 having such specific physical properties does not generate powder, unlike conventionally known expanded polystyrene resin sheets.
It has excellent shape retention and restoration elasticity, so it is extremely durable and can withstand repeated use over a long period of time. In addition, it has excellent water resistance and detergent resistance, so even if it can be washed when soiled, it can withstand reuse.

A foaming ratio of 5 to 5 with such a specific flexural modulus
The 40 times expanded polystyrene resin sheet 1 is made of a polymer such as styrene, α-methylstyrene, ethylstyrene, chlorostyrene, bromustyrene, vinyltoluene, or a copolymer containing 50% by weight or more of these vinyl aromatic vinyl monomers. The combined resin is a styrene-based elastomer, for example, a hard layer made of polystyrene and a soft layer made of at least one of polybutadiene, polyisoprene, or hydrogenated polybutadiene, specifically Tuffprene (Asahi Kasei Corporation), Califrex TR
(Ciel Chemical Co., Ltd.), Solprene-T (Nippon Elastomer Co., Ltd.), Clayton G (Ciel Chemical Co., Ltd.), Lavalon (Mitsubishi Yuka Co., Ltd.), etc. It can be obtained by a molding method such as an extrusion foaming method.

The amount of the styrene elastomer used varies depending on the type of raw material resin used, but it is usually good to include it in the polystyrene resin sheet in an amount of 1.5 to 20% by weight.

The expanded polystyrene resin sheet 1 used in the present invention uses polystyrene as the styrene resin and Tuffprene Y (manufactured by Asahi Kasei Industries, Ltd.) as the styrene elastomer, and these resin compositions are mixed with a blowing agent such as propane, After kneading butane, pentane, dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, or chlorodifluoromethane with various additives as necessary in an extruder under high temperature and high pressure,
It is foam-molded by extruding into the atmosphere from a T-shaped die or an annular die and has a foaming ratio of 5 to 40 times and a bending elastic modulus of 3 to 50 kg/cm ² .

If the flexural modulus of the expanded polystyrene resin sheet 1 is less than 3 kg/cm ² , the shape retention will be poor, and if the flexural modulus exceeds 50 kg/cm ² , the partition material A will be damaged when subjected to impact. Not only does it become easy to break, making it impossible to use it for a long period of time, but it also causes problems such as the generation of powder during punching, which is unique to polystyrene foam, making it impossible to achieve the object of the present invention.

In addition, in the present invention, the thermoplastic resin sheet 2
Examples of the conductive material used include powders of carbon black, graphite, aluminum, copper, nickel, and the like. In order to protect electronic components and the like from static electricity, it is preferable that the electrical resistance value of the thermoplastic resin sheet 2 is 10 ⁴ to 10 ⁶ Ω/cm. The amount of conductive material used for this purpose is usually 10 to 60 parts by weight per 100 parts by weight of the thermoplastic resin.

Any thermoplastic resin can be used in the present invention, including polystyrene, low-density polyethylene, linear low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, polypropylene, and nylon 6. , nylon 6,6, polymethaxylene adipamide, polyvinyl chloride, polyethylene terephthalate, and the like.

The thermoplastic resin sheet 2 used in the present invention is made by kneading the conductive material with the thermoplastic resin, for example,
It can be obtained by applying a molding method such as extrusion molding.

In the present invention, the thickness of the expanded polystyrene resin sheet 1 may be any thickness as long as the conductive sheet has the desired strength.
It is usually 0.5 to 30 mm, preferably 1 to 10 mm.

Further, the thickness of the thermoplastic resin sheet 2 may be any thickness as long as it is thick enough to prevent electrical charging of electronic parts, etc., but in order to reduce the amount of conductive material used and to achieve electrical charging prevention. The diameter is usually 10 to 500 μm, preferably 20 to 100 μm.

The partition material of the present invention is manufactured by laminating a foamed styrene resin sheet 1 and a thermoplastic resin sheet 2 by adhesion with an adhesive or heat fusion. In this case, an adhesive layer may be provided between the two. As the adhesive layer, conventionally known adhesives such as ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-vinyl acetate copolymer, etc.
Butazine-acrylonitrile copolymer and the like are optionally used.

The partition material of the present invention is suitably assembled using the fitting groove 4 as shown in FIG. 4, and is suitably used as a partition material for a container.
In this case, due to its conductive effect, even if electronic parts such as semiconductor parts housed in the inner partition vibrate during storage or transportation, static electricity will not be generated, and even if static electricity is generated for some reason, it will not occur when electronic parts come in contact with each other. By flowing into the partition material, electronic components are prevented from being charged.

〔effect〕

Since the partition material of the present invention has the above-mentioned structure, it has sufficient electrical conductivity, has excellent breaking strength, and generates little powder, so it can be used as a partition material for preventing static electricity problems in electronic parts, etc. be used effectively.

In addition, since such partition materials are generally used when storing and moving parts within the same factory or between the ordering factory and the ordering factory, they can be used repeatedly and can be washed if they become dirty. However, the partition material of the present invention has excellent durability and resistance to detergents, so it satisfies all of the above requirements and has extremely high practical value. It is.

[Brief explanation of the drawing]

Fig. 1 is a front view of the partition material of the present invention, Figs. 2 and 3 are schematic sectional views of the partition material of the invention, and Fig. 4 shows the assembled state of the partition material of the invention. FIG. A: Partition material, 1: Expanded polystyrene resin sheet, 2: Thermoplastic resin sheet, 3: Conductive sheet, 4: Fitting groove.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a partition material made of a conductive sheet in which a thermoplastic resin sheet containing a conductive material is provided on at least one side of a foamed polystyrene resin sheet with an expansion ratio of 5 to 40 times. , the bending elastic modulus of the foamed polystyrene resin sheet is 3 to 50 kg/cm ²
A partition material characterized by: (2) The partition material according to claim 1 of the utility model registration claim, in which a fitting groove of a predetermined groove width is formed at a desired position.