JPH09272565A - Cover tape for emboss carrier tape made of polystyrene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cover tape suitable for an emboss carrier tape made of polystyrene. SOLUTION: This cover tape for an emboss carrier tape made of polystyrene comprises an outer film layer 1, a reinforcing film layer 2, an adhesion enhanced layer 4 and a thermal adhesive layer 5 which are sequentially laminated, wherein (a) the adhesion enhanced layer 4 is formed of a resin composition including polyester-containing resin and (b) the thermal adhesive layer is formed of a resin composition including polyacrylate-containing resin and tetra- alkylammonium chloride.

Description

Detailed Description of the Invention

[0001]

2. Description of the Related Art Chip-type electronic parts for surface mounting such as ICs, transistors, diodes, piezo-electric resistors, capacitors, etc. are plastic embossed carriers in which embossed pockets which can be accommodated according to the shape of the electronic parts are continuously formed. The tape is packaged and supplied in a packaging body including a tape and a cover tape that can be heat-bonded to the embossed carrier tape.

Electronic components, which are contents, are transported and stored in a state of being housed in an embossed carrier tape. Then, at the time of use, the cover tape is peeled and opened on the heat-bonded surface of the embossed carrier tape by the electronic component mounting automatic machine, and the contents are taken out from the package and surface-mounted on the electronic circuit board. As the embossed carrier tape, polystyrene tape is mainly used because it causes little environmental pollution during incineration after use.

However, none of the above-mentioned conventional cover tapes satisfies all of the following characteristics, and there is room for improvement in these points.

(1) The thermal adhesive strength between the cover tape and the embossed carrier tape is in a range that allows easy peeling at the time of peeling and opening the package. Particularly, the thermal adhesive strength when measured under the test conditions described later. It is desirable that the width is about 500 to 1500 g / 15 mm width, and that the thermal bonding strength is uniform without variation.
When the width is less than 500 g / 15 mm, the delamination phenomenon occurs between the embossed carrier tape and the cover tape, so that the electronic component, which is the content, pops out from the inside of the embossed carrier tape during transfer of the package, Dust may enter the package and contaminate the electronic components of the contents.

On the other hand, the thermal adhesive strength is 1500 g / 15 mm
When the width exceeds the width, smooth peeling is hindered, and in this case as well, the electronic component of the contents may fly out of the embossed carrier tape.

Even if the thermal adhesive strength is within the above range, if the strength varies, smooth peeling at the time of opening is hindered. That is, when the electronic component of the contents peels off and opens the cover tape from the embossed carrier tape, a slip-stick phenomenon occurs, which hinders the openability. The slip-stick phenomenon is the process of peeling and opening the cover tape from the embossed carrier tape, and at first it peels smoothly and without resistance,
This is a phenomenon in which peeling is intermittent as a result of gradually increasing resistance and making smooth peeling impossible.

(2) Capable of heat-bonding the cover tape and the embossed carrier tape at a temperature as low as possible. When heat-bonding at a high temperature is required, the electronic component which is the content may be affected by the heat and the quality may deteriorate. There is. The preferred thermal bonding temperature varies depending on the size, shape, etc. of the embossed carrier tape and the type, size, shape, etc. of its contents, but is generally 140 ° C or lower, preferably 120 ° C or lower. .

(3) Sufficient antistatic effect In particular, it is preferable that the surface resistivity of the outer layer surface and the inner layer surface of the cover tape is 10 ¹² Ω / cm ² or less under the test conditions described later.

When the antistatic effect of the cover tape is insufficient, the cover tape is charged and is exposed to the work atmosphere during the manufacturing process of the cover tape, the heat-bonding packaging process of electronic parts, and the peeling and unsealing of the cover tape. As a result of dust and foreign matter being adsorbed, precision electronic components are contaminated with dust and foreign matter, which adversely affects the performance of electronic components. Even if the embossed carrier tape side is antistatic treated, if the electronic parts of the contents are small, it will be more likely to electrostatically adhere to the cover tape side and fall out from the cavity (pocket) of the embossed carrier tape. Or, a position shift occurs, which makes it difficult to automatically mount electronic components. Further, the contact with the charged cover tape causes electric discharge, which may cause electrostatic breakdown of the electronic component.

[0010]

SUMMARY OF THE INVENTION Accordingly, the main object of the present invention is to provide a cover tape suitable for a polystyrene embossed carrier tape.

[0011]

The inventors of the present invention have found that, as a result of intensive studies in view of the above problems of the prior art, a laminate having a specific structure exhibits excellent performance as a cover tape. Has been completed.

That is, the present invention is a cover tape for a polystyrene embossed carrier tape in which an outer film layer, a reinforcing film layer, an adhesion reinforcing layer and a thermal adhesive layer are sequentially laminated, wherein (a) the adhesion reinforcing layer comprises: A heat-adhesive layer (b) formed from a resin composition containing a polyester resin,
The present invention relates to a cover tape formed of a resin composition containing a polyacrylate resin and tetraalkylammonium chloride.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described together with the embodiments thereof.

Outer Layer Film Layer As a material for the outer layer film layer, a known resin film can be used, and for example, polyester, nylon, polypropylene or the like can be used. It is particularly preferable to use a biaxially stretched film for these films.

Further, these films are preferably subjected to antistatic treatment. As the antistatic method, a known method can be adopted, but it is more preferable that the antistatic treatment is performed by corona discharge treatment. In addition,
The antistatic treatment may be applied to at least one surface (one or both surfaces) of the outer film layer.

The thickness of the outer film layer can be appropriately changed depending on the contents, intended use, etc., but is usually 6 to 50 μm.
Degree, preferably 6 to 25 μm.

Reinforcement Film Layer The material of the reinforcement film layer is not particularly limited in its type,
A known resin film can be used. For example,
Polyethylene (linear low-density polyethylene, low-density polyethylene, etc.), ethylene-vinyl acetate copolymer, nylon, etc. can be used.

These films are preferably subjected to antistatic treatment. As the antistatic treatment method, a known method can be adopted, but it is more preferable that the antistatic treatment is performed by corona discharge treatment. The antistatic treatment is
What is necessary is just to make it into at least one surface of a reinforcement film layer.

The thickness of the reinforcing film layer can be appropriately changed depending on the contents, intended use, etc., but is usually 20 to 80.
It is about μ, preferably 20 to 40 μ.

An adhesive may be used for laminating the outer film layer and the reinforcing film layer, if necessary. Therefore, in this case, an adhesive layer exists between the two layers, and a state including the adhesive layer is also included in the present invention. A cover tape including an adhesive layer in the present invention is shown in FIG.

Adhesion Strengthening Layer The adhesion strengthening layer is formed from a resin composition containing a polyester resin. Among these, a two-component reaction type resin of a linear saturated polyester resin and an isocyanate resin (curing agent) is particularly preferable. Further, it is preferable to use a solvent-soluble resin composition. These may be commercially available products.

If necessary, an antistatic agent or the like can be appropriately added to the adhesion strengthening layer. The antistatic agent is
Known ones can be used.

The coating amount of the adhesion-strengthening layer can be appropriately changed depending on the content, intended use, etc., but is usually 0.5-2.
It may be about 0 g / m ² (solid content). The presence of the adhesion-strengthening layer enhances the adhesion between the thermal adhesive layer and the reinforcing film to make it strong.

Thermal Adhesive Layer The thermal adhesive layer is formed from a resin composition containing a polyacrylate resin and tetraalkylammonium chloride.

Known polyacrylate resins can be used, and commercially available products can also be used. Among them, those soluble in a solvent are particularly preferable.

The tetraalkylammonium chloride has at least one alkyl group having 12 to 2 carbon atoms.
A tetraalkylammonium chloride of 0 is preferred. Among them, particularly, the general formula ([RN (CH ₃ ) ₃ ] ⁺
Cl ⁻ , R: alkyl group), and alkyl trimethyl ammonium chloride is more preferable. These can also use what is marketed.

The content ratio of the above tetraalkyl chloride is usually about 2.5 to 14.0 parts by weight (solid content), preferably 5.0 to 10. parts with respect to 100 parts by weight of polyacrylate resin (solid content). It may be 0 parts by weight (solid content). The coating amount in the thermal adhesive layer is usually about 1.0 to 6.0 g / m ^{2 in} terms of resin solid content, and more preferably 1.0 to 2.0 g / m ² .

The cover tape of the present invention can be obtained by laminating each of these layers according to a known method. For example,
First, as the outer layer film layer, a biaxially stretched polyester film that has been previously subjected to corona discharge treatment is used, and is bonded to the reinforcing film by a dry laminator. In this case, a known adhesive may be used for laminating the outer layer film and the reinforcing film. For example, a two-component curable urethane dry laminating adhesive may be applied in an amount of 4 to 5 g / m ^{2 in} terms of resin solid content. It is only necessary to apply the solution to the extent that it is on the order and dry it. Next, using a gravure coater or the like, an adhesion strengthening layer is formed on the lower surface of the reinforcing film so as to have a predetermined coating amount. Finally, using the gravure coater or the like again, the thermal adhesive is applied to the lower surface of the adhesion reinforcing layer and dried to form the thermal adhesive layer, whereby the cover tape of the present invention can be obtained.

The cover tape of the present invention can be used by being heat-bonded to the opening edge of the embossed carrier tape as shown in FIG. The heat bonding conditions may be appropriately set depending on the composition of the heat adhesive layer, the type of the embossed carrier tape, and the like.

[0030]

According to the cover tape of the present invention, since it has excellent low-temperature thermal adhesiveness, it is possible to avoid the deterioration of the quality of the electronic parts, which are the contents, due to the heat. Further, when the electronic component of the contents is taken out, since the thermal adhesive layer of the cover tape has an easy-open property, the electronic component does not drop out of the cavity of the carrier tape and the position is not displaced, so that the electronic component can be automatically mounted. It can be done easily.

Further, since the cover tape of the present invention is excellent in its antistatic effect, there is no obstacle to electronic parts due to dust or foreign matter in the working atmosphere. In addition, even if the electronic component comes into contact with the cover tape, the electronic component does not suffer from electrostatic breakdown due to a discharge phenomenon.

The cover tape having such characteristics is
Particularly, it can be suitably used for a polystyrene embossed carrier tape.

[0033]

EXAMPLES Examples and comparative examples are shown below to further clarify the features of the present invention.

Examples 1 to 3 and Comparative Examples 1 to 14 Cover tapes were manufactured using the materials shown in Tables 1 to 3, respectively.

First, as the film for forming the outer film layer, a biaxially stretched polyester film whose lower surface (that is, a surface to be laminated with the reinforcing film) is previously subjected to corona discharge treatment is used, and the film is attached to the reinforcing film with a dry laminator. I matched it.

In the dry laminator coating zone, a two-component curing type urethane dry laminating adhesive is coated on the lower surface of the outer layer film in an amount of 4 to 5 g in terms of resin solid content.
/ M ² and dried in the drying zone, and then laminated with the reinforcing film in the laminating zone.

Next, using a gravure coater, an adhesion strengthening layer was formed on the lower surface of the reinforcing film so that the coating amount was 1.5 g / m ^{2 in} terms of resin solid content.

Then, using a gravure coater again, 1.5 g / resin of resin solid content was applied to the lower surface of the adhesion strengthening layer.
A thermal adhesive was applied so that the coating amount was m ² , and the adhesive was dried to form a thermal adhesive layer to obtain a cover tape. However, as the tetraalkylammonium chloride, a commercially available antistatic agent containing it was used.

Comparative Example 4 was manufactured by the same method as described above except that the step of forming the adhesion strengthening layer was omitted. Comparative Examples 12 to 14 are commercially available cover tapes, the configurations of which are shown in Tables 4 and 5. Comparative Example 12 is
An outer film layer, a reinforcing film layer, and a solvent-insoluble type thermal adhesive layer containing an inorganic pigment as an antistatic agent are sequentially laminated. In Comparative Example 13, a solvent-insoluble type thermal adhesive layer containing an inorganic pigment as an antistatic agent is provided on the lower surface of the outer layer film.

Comparative Example 14 is an outer film layer, a reinforcing film layer, a biaxially stretched PET film layer containing an inorganic pigment as an antistatic agent, and a solvent-soluble type containing an inorganic pigment as an antistatic agent. The heat-adhesive layer is sequentially laminated.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Table 3]

[0044]

[Table 4]

[0045]

[Table 5]

The resins and the like used in Tables 1 to 3 are as shown below.

* Outer film layer (Examples 1 to 3 and Comparative Examples 1 to 11) Biaxially stretched polyethylene terephthalate (Toyobo Co., Ltd.)
Made by "ESPET T6140", thickness 12μ) * Reinforcement film layer Linear low density polyethylene ("Samohan LS30" manufactured by Thermo Co., Ltd.) * Adhesion strengthening layer (1) Polyester resin ("Dixel A970" Dainippon Ink Chemical Industry Co., Ltd.) and curing agent (“KX75” Dainippon Ink & Chemicals Co., Ltd.) compound resin: compound ratio 1
00/5 * Adhesion-strengthening layer (2) Polyurethane-based resin (“ADCOAT AD335AE” manufactured by Toyo Morton Co., Ltd.) and isocyanate-based curing agent (“C
AT10 "blended resin with Toyo Morton Co., Ltd . : Blending ratio 100/10 * Adhesion-strengthening layer (3) Polyisocyanate-based resin (" EL150 "Toyo Morton Co., Ltd.) and amine resin-based reaction accelerator (" CAT20
0 ”compounded resin with Toyo Morton Co., Ltd .: compounding ratio 1
00/2 * Adhesion-strengthening layer (4) Polyethyleneimine one-component resin (“EL420” manufactured by Toyo Morton Co., Ltd.) * Thermal adhesive layer polyacrylate resin (“Dixel A450A”)
Dainippon Ink and Chemicals, Inc. * Antistatic agent (1) Monoalkylammonium chloride ("Arcade T"
50 "manufactured by Lion Co., Ltd. * Antistatic agent (2) Monoalkylammonium chloride (" ARCARD C "
50 "Lion Co., Ltd. * Antistatic agent (3) Alkylamine compound (" Esomin C / 15 "Lion Co., Ltd.) * Antistatic agent (4) Alkylamine compound (" Esomin T / 15 ") Lion Co., Ltd. * Antistatic agent (5) Alkylamine compound ("Esomin S / 15" Lion Co., Ltd.) The obtained cover tape was tested for low temperature thermal adhesion and slip sticking phenomenon by the following methods. The presence or absence and the transparency were evaluated. The results are shown in Tables 6-10.

(1) Presence / absence of low-temperature thermal adhesiveness and slip-stick phenomenon A HIPS sheet of 300 μ (“M5 manufactured by Sumitomo Chemical Co., Ltd.”
83 ”) and 3 kg / cm ² × 1 second with a heat sealer (manufactured by Toyo Seiki Co., Ltd.). At this time, the heat bonding temperature is 1
The temperature was changed to 20 ° C., 140 ° C. and 160 ° C., and the thermal adhesive strength at each temperature was measured.

The thermal adhesive strength is measured according to JIS. It carried out in accordance with K6854. However, a sample cut into a 15 mm wide strip was prepared, the peeling angle was 180 ° (the sample was bent to 180 °), and the peeling speed was 300 mm / min.

The thermal adhesive strength was recorded on a self-recording chart paper, but if there were variations, the slip-stick phenomenon occurred. To further confirm this, heat-bond the 15 mm wide sample by hand with a certain force and
Peeling was performed at 0 ° and the peeling condition was visually observed. As a criterion, "no" was defined as the case where the resistance was continuously peeled off with a constant resistance, and "yes" was defined as the case where the resistance was discontinuous and peeled off when the resistance was jerky.

For Comparative Examples 12 to 14, which are commercially available products, stable thermal adhesive strength (500 to 1500 g / 1) without variation at low thermal adhesive temperatures of 120 to 160 ° C.
5mm width) was not obtained, so 180-220
The heat-bonding strength when heat-bonded at a high temperature of ℃ was also measured.

(2) Surface resistance Surface resistance meter (“MCP-HT25” manufactured by Mitsubishi Chemical Corporation)
0 ") at 25 ° C. and a relative humidity of 35%. The measurement was performed on both the outer layer surface (outer layer film layer side) and the inner layer surface (thermal adhesive layer side).

(3) Transparency Self-recording spectrophotometer ("MPS500" manufactured by Shimadzu Corporation)
0 "measuring device) for Examples 1 to 3 and Comparative Examples 1 to 14
The visible light transmittance of the cover tape was measured.

[0054]

[Table 6]

[0055]

[Table 7]

[0056]

[Table 8]

[0057]

[Table 9]

[0058]

[Table 10]

From the results of Examples 1 to 3 and Comparative Examples 4 to 7, the adhesion-strengthening layer obtained by crosslinking the solvent-soluble polyester resin with isocyanate was excellent in low-temperature thermal adhesiveness, while in Comparative Examples 4 to 7. It can be seen that the adhesion strengthening layer is inferior in low temperature heat adhesion.

The heat-adhesive layers of Examples 1 to 3 were composed of a solvent-soluble polyacrylate resin having excellent low-temperature heat-adhesiveness, and had an easy-opening property at a low temperature of 120 ° C. It is a solvent-soluble resin type. On the contrary,
Since the comparative examples 12 to 13 of the conventional products require a heat bonding temperature of 180 ° C. or higher, they are inferior in low temperature heat bonding performance. Especially,
In Comparative Example 13, the slip stick phenomenon occurred. Further, the conventional product, which is a comparative example, could not obtain sufficient thermal adhesive strength at both low temperature and high temperature.

Further, as can be seen from Comparative Examples 1 and 2, the amount of tetraalkylammonium chloride (antistatic agent) added was less than 2.5 parts by weight based on 100 parts by weight of the solvent-soluble polyacrylate resin (solid content). In the case of a resin composition having a solid content, the surface resistance (inner layer surface) is as large as 10 ¹⁴ Ω / cm ^2, and the antistatic effect is not recognized. On the other hand, in the case of the resin composition obtained by adding 15.0 parts by weight (in solid content) to 100 parts by weight of solvent-soluble polyacrylate (solid content) as in Comparative Example 3, the surface resistance (inner layer surface) Shows a relatively good performance of 10 ⁸ Ω / cm ² , but the low temperature thermal adhesiveness is not sufficient. On the other hand, 3.3 to 13.3 with respect to 100 parts by weight (solid content) of the solvent-soluble polyacrylate resin of Examples 1 to 3.
In the resin composition added with parts by weight (in solid content),
It can be seen that the low temperature thermal adhesiveness and the surface resistance value are good.

In Comparative Examples 8 to 11, since the tetraalkylammonium chloride of the present invention was not used in the thermal adhesive layer, the low temperature thermal adhesiveness was inferior.

On the other hand, it is visually inspected whether or not the electronic components as the contents are accommodated in a predetermined state in the cavity of the embossed carrier tape (presence or absence of accommodation, direction of accommodation, etc.). The inspection is preferably performed from both the embossed carrier tape side and the cover tape side of the package. For this reason, the cover tape is required to have excellent transparency, but comparative examples 12 to 14 which are conventional products.
The visible light transmittance is 80 to 85%, while all of Examples 1 to 3 are 90%, which means that the transparency is excellent.

As is clear from the above results, the cover tape according to the present invention is comprehensively excellent in various characteristics such as low temperature thermal adhesiveness, surface resistance (outer layer surface / inner layer surface), slip stickiness and transparency. You can see that

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a layer structure of a cover tape of the present invention.

FIG. 2 is a schematic view showing a state in which the cover tape of the present invention is heat-bonded to a carrier tape.

Claims (4)

[Claims] 1. A cover tape for a polystyrene embossed carrier tape, which comprises an outer film layer, a reinforcing film layer, an adhesion strengthening layer, and a thermal adhesive layer, which are laminated in this order.
(A) The adhesion-strengthening layer is formed of a resin composition containing a polyester resin, and (b) the thermal adhesive layer is formed of a resin composition containing a polyacrylate resin and tetraalkylammonium chloride. Characteristic cover tape. 2. In a tetraalkylammonium chloride, at least one of the alkyl groups has 12 to 12 carbon atoms.
The cover tape according to claim 1, wherein the cover tape is 20. 3. The cover tape according to claim 1, wherein the tetraalkylammonium chloride is a monoalkyltrimethylammonium chloride, and the alkyl group has 12 to 20 carbon atoms. 4. The thermal adhesive layer comprises a polyacrylate resin 1
The cover tape according to claim 1, which is formed from a resin composition containing 2.5 to 14.0 parts by weight (solid content) of tetraalkylammonium chloride with respect to 00 parts by weight (solid content). .