JPH0986558A - Packaging material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging material wherein static electricity can be surely prevented from being generated by imparting conductivity to the material, and conductivity can be obtained at low cost, and at the same time, anchor effect (anchoring force) of a self-bonding layer with respect to a base material film is not injured by imparting conductivity. SOLUTION: In a tape or sheet-shaped packaging material in which self- bonding layers formed on opposite surfaces or on one surface of a base material film are bonded to each other by pressure-sensitive bonding to package an item, carbon powders 4 for forming conductive filter, are uniformly mixed into primer layers 2a, 2b formed between a base material film 1 and self-bonding layers 3a, 3b, and particles of the powders 4 are dispersed so as to be spaced apart, one from another, by such intervals that electrons are not hindered from moving.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape-shaped or sheet-shaped packaging material used for various packaging such as bundling, tightening, encapsulation, etc. of products, and in particular, there is a possibility that product defects may occur due to the influence of static electricity. The present invention relates to a packaging material having an optimum conductivity for industrial packaging such as a semiconductor device.

[0002]

2. Description of the Related Art As a tape-shaped packaging material for bundling or tightening items, adhesive tape such as cellophane tape, vinyl tape, gum tape, etc. is generally used. If you pack a cardboard box filled with items or a plastic pack container that contains items in blister or cell recesses, when the tape is peeled off, the reaction may cause the items to pop out of the pack container and scatter. However, there is a problem that the surface of the cardboard box is torn by the adhesive force of the tape or the adhesive of the tape remains on the surface of the article and stains the surface.

Further, as a material for strip packaging for continuously compartmentalizing and packaging small items such as medicine tablets and candies, polyethylene film, polyethylene-treated cellophane, aluminum foil laminated film, etc. are used. Since these films are heat-sealed by an expensive heat sealing device to hermetically package the product, there is a problem that the packaging cost increases. In addition, there is a possibility that the quality of the product may change due to heat.

In view of the above circumstances, a tape-like or sheet-like product is formed in which self-adhesive layers having no tackiness are formed on both sides or one side of a base film and the self-adhesive layers are pressure-sensitively adhered to each other to wrap an article. -Shaped packaging materials have been developed (JP-A-60-26077, JP-A-3-14402, JP-A-3-45673, Shoukai-60-37045).

Here, the tape-shaped packaging material in which the self-adhesive layers are formed on both front and back surfaces of the base film, the self-adhesive layers on both front and back surfaces of the tape when wrapped around an article or a cardboard box. Since the pressure-sensitive adhesives are bonded only to each other and not to the surface of the article or the corrugated cardboard box, there is an advantage that the surfaces are not damaged or soiled.

On the other hand, the sheet-shaped packaging material in which the self-adhesive layer is formed only on one side of the base film, the product is sandwiched between two sheets arranged so that the self-adhesive layer faces each other. By passing between pressure rolls, self-adhesive layers can be pressure-sensitively adhered to each other along the periphery of the product to hermetically package the product, which is similar to strip packaging without using a heat-sealing device. The advantage is that

[0007]

By the way, the packaging material having the above-mentioned advantages was considered to be suitable for industrial packaging of semiconductor elements and the like. There is a risk that the product quality of semiconductor devices will be impaired by the static electricity that occurs,
Its use was cut off. Therefore, the present invention provides conductivity to the packaging material of the method of pressure-sensitively adhering the self-adhesive layers formed on the surface of the base film to surely prevent generation of static electricity, and at the same time, conducts electricity at low cost. The technical issue is to prevent the anchoring property (anchoring force) of the self-adhesive layer from being imparted to the base film by impairing the effect while simultaneously obtaining the effect.

[0008]

In order to solve the above-mentioned problems, the present invention provides a tape-like package for packaging an article by pressure-sensitively adhering self-adhesive layers formed on both sides or one side of a base film to each other. In the sheet-shaped packaging material, the primer layer formed between the base film and the self-adhesive layer, carbon powder serving as a conductive filler is uniformly mixed, and the particles of the carbon powder are It is characterized in that the particles are dispersed at intervals such that they do not hinder the movement of electrons.

In the packaging material of the present invention, conductivity is imparted by the carbon powder mixed in the primer layer formed between the base film and the self-adhesive layer to prevent generation of static electricity. In particular, the carbon powder mixed in the primer layer exerts a sufficient conductive effect even when the particles are not in contact with each other and are dispersed at a distance that does not hinder the movement of electrons between the particles. . Therefore, the amount of the carbon powder used can be small, and at the same time, the anchoring force of the primer layer to the base film due to the incorporation of the carbon powder can be minimized.

Further, a part of the particles of the carbon powder mixed in the primer layer floats out on the surface of the primer layer, and the surface of the primer layer has innumerable minute irregularities such as those subjected to a sander treatment. A decrease in the anchoring force of the self-adhesive layer to the surface is prevented. Further, since the particles of carbon powder are mixed in the primer layer formed between the base film and the self-adhesive layer, there is no possibility that the particles will be transferred and adhered to the surface of the packaged product.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a side view showing an example of the packaging material according to the present invention, FIG. 2 is a perspective view showing its use state, FIG. 3 is a side view showing another example of the packaging material according to the present invention, and FIG. 4 is its use. It is a perspective view showing a state.

The packaging material A shown in FIGS. 1 and 2 has a thickness of 2 to 8 .mu.m (preferably 3 to 6 .mu.m) on both front and back surfaces of a base film 1 made of a tape-shaped synthetic resin film.
And the self-adhesive layers 3a and 3b are formed on the primer layers 2a and 2b. Then, carbon powder 4 serving as a conductive filler is applied to both or one of the primer layers 2a and 2b.
Are uniformly mixed, and the particles of the carbon powder 4 are dispersed at intervals such that the movement of electrons is not hindered between the particles.

The carbon powder 4 mixed in the primer layers 2a and 2b has a particle diameter of 1 to 30 μm (preferably,
2 to 15 μm), and 2 to 20 parts by weight (preferably 5 to 10 parts by weight) with respect to 100 parts by weight of a solid polymer component (primer solid content) showing strong adhesion to the surface of the base film 1. Part) is mixed. If the compounding ratio of the carbon powder 4 is less than the above ratio, the intervals between the particles are too wide and the movement of electrons is hindered, so that a sufficient conductive effect cannot be obtained.

Further, the self-adhesive layers 3a and 3b are formed by an emulsion type adhesive having a pressure-sensitive adhesive property between the dried and solidified adhesives, and the thickness thereof is selected to be about 3 to 8 μm. As the emulsion type adhesive forming the self-adhesive layers 3a and 3b, a mixture of a methyl methacrylate / butyl acrylate resin emulsion and a polyacrylic acid ester copolymer resin emulsion, or an ethylene-vinyl acetate copolymer resin is used. An emulsion or the like is used.

As shown in FIG. 2, the tape-shaped packaging material A configured as described above is manufactured in a state of being wound on the paper tube 5, and is unwound from the paper tube 5 to be packaged. It is wound around the article 6 to be wrapped. At this time, when the packaging material A is unwound from the paper tube 5, the self-adhesive layers 3a and 3b, which have been overlapped and adhered to each other, are once peeled off, and when wrapped around the article 6. , The self-adhesive layers 3a and 3b are re-adhered to each other at their overlapping portions, whereby the article 6 is firmly bound or tightened.

Since the carbon powder 4 mixed in the primer layers 2a and 2b imparts conductivity to the packaging material A in which the items 6 are bound and tightened, there is no possibility of generating static electricity. (Note that the present invention is not limited to the case where the carbon powder 4 is mixed into both the primer layers 2a and 2b, and may be the case where it is mixed into only one of the primer layers 2a and 2b.) Since the particles are mixed so as to be dispersed at an interval that does not hinder the movement of electrons, the amount used can be very small, and the cost of the packaging material A can be reduced.

If the amount of carbon powder 4 used is small, the primer layers 2a, 2 for the base film 1 are formed.
Since the decrease in the anchoring force of b and the decrease in the anchoring force of the self-adhesive layers 3a and 3b with respect to the primer layers 2a and 2b are suppressed to a minimum, the self-adhesive layers 3a and 3b are adhered to each other in an overlapping state. When the packaging material A is unwound from the paper tube 5, the problem that the self-adhesive layers 3a and 3b are separated from the base film 1 made of polypropylene film or the like does not occur.

The primer layers 2a and 2b having the carbon powder 4 mixed therein have innumerable particles of the carbon powder 4 protruding on the surface thereof, and fine irregularities are generated as when sanding is applied. Self-adhesive layer 3a,
The anchoring property of 3b is rather improved. Further, the carbon powder 4 does not come into contact with the surface of the article 6, the primer layers 2a and 2b.
Since the self-adhesive layers 3a and 3b that are mixed in the product 6 and contact the surface of the product 6 do not have tackiness, there is no possibility of damaging or soiling the surface of the product 6.

Next, in the sheet-shaped packaging material B shown in FIGS. 3 and 4, the primer layer 2 is formed only on one surface of the base film 7 made of a sheet-shaped synthetic resin film. The self-adhesive layer 3 is formed on top. Then, the carbon powder 4 is uniformly mixed in the primer layer 2, and the particles of the carbon powder 4 are
The particles are dispersed at intervals such that they do not hinder the movement of electrons. The packaging material B is formed by sandwiching an article between the self-adhesive layers 3 and 3 formed by folding a single sheet in two and facing each other, or as shown in FIG. The article 8 is sandwiched between the and 3 to be encapsulated.

[0020]

EXAMPLES Specific examples of the packaging materials A and B will be described below. First, on the surface of the base material films 1 and 7 made of polypropylene film, 100 parts by weight of the solid polymer component of the acrylic primer agent (# 1000A manufactured by Toyo Kagaku Co., Ltd.) is used as the conductive filler, and the particle diameter is 2
~ 15 μm carbon powder 4 (Ketjen Black EC 6 manufactured by Ketjen Black International Co., Ltd.
00JD) A solution of polyethyleneimine mixed with 5 to 10 parts by weight and a crosslinking agent of 0.5 parts by weight is applied, and the coating film is applied to 60 to 8 parts.
It was dried under heating at 0 ° C. to form primer layers 2, 2a, 2b having a thickness of 4 μm.

Then, the primer layers 2, 2a, 2b
From the above, a predetermined amount of a methylmethacrylate / butyl acrylate resin that is an aqueous polymer that does not exhibit tackiness after being dried and solidified, and a polyacrylic acid ester copolymer resin that is an aqueous polymer that exhibits tackiness after dried and solidified The emulsion type adhesives mixed in the mixing ratio were applied and dried to form the self-adhesive layers 3, 3a, 3b having a thickness of 3 to 6 μm.

A packaging material A obtained as described above,
When observing the cross section of each of the primer layers 2, 2a, 2b of B with a microscope, the particles of the carbon powder 4 are not in a state of being aggregated and connected to each other, and the intervals between the particles are about 1 to 5 μm on average. It was in a dispersed state, and the electric resistance value of its surface was about 10 to 10 ² Ωcm. In addition, innumerable particles of the carbon powder 4 are floated on the surfaces of the primer layers 2, 2a, 2b, and fine irregularities as if a sander treatment has been applied to the surfaces thereof are formed. , 3a, 3b and the primer layers 2, 2a, 2b are firmly adhered as if they were occluded by a surface fastener, and the particles of the carbon powder 4 which cause the unevenness dig into the self-adhesive layers 3, 3a, 3b. It is in a state.

From the above, the packaging materials A and B of the present invention have the carbon powder 4 in the primer layers 2, 2a and 2b.
It was demonstrated that a sufficient conductive effect can be obtained even if the particles of (3) are mixed in a dispersed state and the self-adhesive layers 3, 3a, 3b are formed on the primer layers 2, 2a, 2b. If the surface electric resistance values of the packaging materials A and B are 10 Ωcm or less, which is similar to those of metals, the static electricity generated from the base material films 1 and 7 is discharged to the ground object without being thermally converted. Although it cannot be used for packaging semiconductor devices, there is a possibility that the primer layers 2, 2a, 2b having a surface electric resistance value of 10 to 10 ² Ωcm may be used.
If the self-adhesive layers 3, 3a and 3b are further formed on the above, the surface electric resistance values of the packaging materials A and B are 10 ⁴ to 10 ^{6 respectively.}
Since it is about Ωcm, there is no danger of discharge.

[0024]

According to the present invention, a tape-like or sheet-like packaging material that can be used inexpensively and easily for an article such as a semiconductor element which may cause a product defect due to the influence of static electricity or the attachment of dirt. It has a very excellent effect that it can be safely packaged.

[Brief description of drawings]

FIG. 1 is a side view showing an example of a packaging material according to the present invention.

FIG. 2 is a perspective view showing a usage state of the packaging material shown in FIG.

FIG. 3 is a side view showing another example of the packaging material according to the present invention.

FIG. 4 is a perspective view showing a usage state of the packaging material shown in FIG.

[Explanation of symbols]

 A ... Tape-shaped packaging material B ... Sheet-shaped packaging material 1 ... Base film 2 ... Primer layer 2a ... Primer layer 2b ... Primer layer 3 ... Self-adhesive layer 3a ... Self-adhesive layer 3b ... Self-adhesive layer 4 ... Carbon powder 6 ... Product 7 ... Base film 8 ... Product

Claims (3)

[Claims] 1. A tape-shaped or sheet-shaped packaging material for packaging an article by pressure-sensitively adhering self-adhesive layers formed on both sides or one side of a substrate film to each other, wherein the substrate film (1, 7) is used. ) And a self-adhesive layer (3, 3a, 3b)
Primer layer (2, 2a, 2b) formed between
The carbon powder (4), which is a conductive filler, is uniformly mixed with the particles of the carbon powder (4).
A packaging material characterized in that the particles are dispersed at intervals such that they do not interfere with the movement of electrons. 2. The package according to claim 1, wherein the compounding ratio of the solid polymer component forming the primer layer (2, 2a, 2b) and the carbon powder (4) is 100 parts by weight: 2 to 20 parts by weight. Materials. 3. The carbon powder (4) has a particle size of 1 to
The packaging material according to claim 1, wherein the primer layer (2, 2a, 2b) has a thickness of 2 to 8 µm, and the self-adhesive layer (3, 3a, 3b) has a thickness of 3 to 6 µm.