JP2000321985A - Heat resisting label - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the increase of a production cost and to obtain sufficient taber stiffness by providing the above label with a base film which is formed of material not having a melting point or material having a glass transition temperature of a specific temperature or above, a heat resisting cost layer which is formed of a resin or the resin and fillers on the rear surface thereof and has specific heat resistance and an adhesive layer on the rear surface of this heat resisting coat layer. SOLUTION: The base film 21 is a heat resistant synthetic resin film not having the melting point or having the glass transition temperature of >=110 deg.C. The heat resisting coat layer 22 is applied on the front surface of the base film 21. The heat resisting surface coat layer 22 is formed of material which satisfies the requirements as a ground surface layer for printing. The heat resisting coat layer 24 is applied on the rear surface of the base film 21. Further, the front surface thereof is provided with the pressure sensitive adhesive layer 23. The heat resisting coat layer 24 is formed of the resin or the mixture composed of the resin and the fillers and has the heat resistance of 260 deg.C and >=5 seconds. The pressure sensitive adhesive layer 23 is of the same constitution as the constitution of the conventional pressure sensitive adhesive layers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat-resistant label,
In particular, the present invention relates to a heat-resistant label which is affixed to a processing target using an auto label and identifies the processing target.

[0002]

2. Description of the Related Art For a processing step, an object to be processed is identified,
2. Description of the Related Art In order to control a process, a heat-resistant label on which a barcode or the like is printed or printed is attached to a processing object. The object to be processed is, for example, a printed circuit board (PC),
High temperature parts around automobile engines, steel, injection molds, EPROMs, etc.

[0003] The processing step often includes a high-temperature step such as solder dip, and requires heat resistance to withstand a high-temperature atmosphere of 250 ° C to 300 ° C for 5 seconds to several tens of minutes. The heat resistance includes the readability of a barcode or the like.

[0004] In order to print or print barcodes and the like,
A white heat-resistant coat layer is applied to the surface of the base film. In addition, in order to stick the heat-resistant label on the object to be processed,
A pressure-sensitive adhesive layer is provided on the back surface of the base film.
The pressure-sensitive adhesive layer is provided by forming a pressure-sensitive adhesive layer on the surface of a release paper such as glassine paper, for example, and affixing a base film thereon. When the release paper is peeled off, a pressure-sensitive adhesive layer remains on the back surface of the base film.

As a base film, a heat-resistant polyimide film, polyetherimide film or the like is used. In order to accurately read a printed or printed barcode or the like, it is desired that the heat-resistant label has a small degree of expansion and contraction even after experiencing the heating step.

In recent years, an auto labeler (automatic sticking machine) has been widely used for sticking a heat-resistant label to an object to be processed. In the case of Auto Lover, the heat-resistant label is protruded, and the release paper is bent at an acute angle and peeled off. The protruding label is picked up by hand or picked up by a vacuum chuck using reduced pressure, and is attached to a workpiece. If Taber stiffness (rigidity, stiffness, "Stiffness test method of paperboard with Taber stiffness tester: JIS
If P8125 ") is low, the label will not be protruded and will be folded together with the release paper, which may lead to failure in picking up the heat-resistant label.

In order to impart sufficient Taber stiffness to a heat-resistant label, conventionally, (1) thickening the base film,
(2) Methods such as thickening the white heat-resistant coat layer on the surface have been adopted. According to the method (1), for example, 25 μm
Since a thick polyimide film has insufficient Taber stiffness, a polyimide film having a thickness of 50 μm is used.
However, when a polyimide film having a thickness of 50 μm is used,
The cost of manufacturing heat-resistant labels can be quite high. The method (2) of increasing the thickness of the heat-resistant white coat layer on the surface can suppress the increase in the manufacturing cost, but the improvement of the Taber stiffness is likely to be insufficient, and the curl (warpage) during heating.
Tends to occur.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-resistant label which can suppress an increase in manufacturing cost and has a sufficient Taber stiffness.

Another object of the present invention is to provide a heat-resistant label which is less likely to undergo thermal expansion and contraction due to a heating step.

Still another object of the present invention is to provide a heat-resistant label which has a low degree of curling during the processing step and has small thermal expansion and contraction.

[0011]

According to one aspect of the present invention, a material having no melting point or a glass transition point of 110 ° C.
A base film formed of the above materials, an adhesive layer provided on a lower surface of the base film, and a resin or a resin and a filler provided between the lower surface of the base film and the adhesive layer. And a heat-resistant label having a heat resistance of 260 ° C. for 5 seconds or more.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the operation of picking up a heat-resistant label using an auto-labeler will be described.

FIGS. 2A to 2C are schematic cross-sectional views for explaining the operation of picking up a heat-resistant label using an auto-labeler.

As shown in FIG. 2A, the heat-resistant label 2 is mounted on a release paper 3 and driven by rollers 6a and 6b. The heat-resistant label 2 has a surface coat layer 22 of usually white on the front side of the base film 21 and a pressure-sensitive adhesive layer 23 on the back side.

A printer head is provided in the transport path of the heat-resistant label, and prints or prints on the surface coat layer 22 of the heat-resistant label 2. The heat-resistant label after printing is conveyed to the wedge-shaped bending member 4. The release paper 3 is sharply bent at an acute portion of the wedge-shaped bending member 4.

As shown in FIG. 2B, when the release paper 3 is bent and driven, the heat-resistant label 2 has rigidity, so that the heat-resistant label 2 does not bend together with the release paper 3 and the wedge-shaped bending member 4 does not.
From the front.

As shown in FIG. 2C, the protruded heat-resistant label 2 is picked up by the vacuum suction tentacle 5 and transported onto the object to be processed, and the heat-resistant label 2 is attached to the object to be processed.

If the rigidity of the heat-resistant label 2 is insufficient, the heat-resistant label 2 is bent along with the release paper 3 along the acute-angle portion of the wedge-shaped bent member 4, and fails to protrude. Then, the vacuum suction tentacle 5 cannot pick up the heat-resistant label 2 and the operation is interrupted.

A 25 μm-thick polyimide film is used as a base film, and a 25 μm-thick white coating layer (“White Coating Agent for Unons Label” manufactured by Unon Giken Co., Ltd.) 22 is applied to the surface of the base film. When the heat-resistant pressure-sensitive adhesive layer was provided, the heat-resistant label was bent together with the release paper 3, and the removal of the heat-resistant label 2 failed.

When the base film 21 is replaced with a polyimide film having a thickness of 50 μm, and the front heat-resistant white coat layer 22 and the back pressure-sensitive adhesive layer 23 have the same structure, the heat-resistant label 2 can be projected well, The heat-resistant label 2 was successfully taken up.

When a polyimide film having a thickness of 25 μm is used, the Taber stiffness of the heat-resistant label 2 is about 0.4 gf.
Cm. When a 50 μm thick polyimide film was used as the base film, the Taber stiffness of the heat-resistant label 2 was about 1.2 gf · cm. From this result, it was found that when the heat-resistant label had a Taber stiffness equal to or more than a certain value, the protrusion was performed well, but when the Taber stiffness was insufficient, the heat-resistant label failed to protrude. By increasing the thickness of the base film, the Taber stiffness of the heat-resistant label can be improved, but in this case, the production cost of the heat-resistant label increases.

There is also a method for improving the Taber stiffness of the heat-resistant label by increasing the thickness of the white heat-resistant coating layer on the front surface side. However, the improvement of the Taber stiffness of the heat-resistant label is insufficient, Curling of the label is likely to occur.

The present inventor proposes to add a layer for improving the Taber stiffness of the heat-resistant label between the base film of the heat-resistant label and the pressure-sensitive adhesive layer.

FIG. 1 is a sectional view showing the structure of a heat-resistant label according to an embodiment of the present invention. On the surface of the base film 21, a heat-resistant surface coat layer 22 is applied. The base film 21 is, for example, a heat-resistant synthetic resin film having a thickness of 25 μm. Synthetic resin film is about 25μ thick
m, about 50 μm and the like are commercially available as standard products. In this specification, the thickness 2 including the manufacturing error is included.
The thickness of a commercially available 5 (50) μm film is called about 25 (50) μm.

The heat-resistant surface coat layer 22 on the front side satisfies the requirements as a base layer for printing.
It is formed with a heat-resistant white coating agent manufactured by Unon Giken (surface white coat for Unons label).

On the back surface of the base film 21, a heat-resistant coating layer 24 is applied, and on the surface thereof, a pressure-sensitive adhesive layer 23 is provided. The heat-resistant coat layer 24 is formed of a resin or a mixture of a resin and a filler. Multiple resins can be used. In this case, a resin material obtained by mixing a plurality of resins may be used, or a plurality of resin layers may be laminated. When a plurality of resin layers are laminated and a filler is used, the filler may be mixed with each layer of the laminate, or may be mixed with some layers of the laminate. The pressure-sensitive adhesive layer 23 has the same configuration as the conventional pressure-sensitive adhesive layer.

Hereinafter, each component of the heat-resistant label shown in FIG. 1 will be described in more detail.

(1) Base Film 21 In many cases, the heat-resistant label goes through a solder dip process. For this reason, heat-resistant labels must be at least 260 ° C,
Heat resistance of at least 260 ° C. for 15 seconds or more is required. Further, on the surface of the base film, a heat-resistant white coating agent layer for improving ink adhesion is provided for printing or printing a barcode or the like.

A base film satisfying such conditions has high heat resistance and smoothness, and the following materials can be used.

(A-1) Amorphous heat-resistant film Polysulfone (PSF), polyethersulfone (PES), and polyetherimide (PEI) can be used as the amorphous heat-resistant film. These materials do not have a melting point. However, films of these materials are liable to deteriorate in strength with respect to aromatic hydrocarbons. Therefore, it is desirable to use an aliphatic hydrocarbon or an alcoholic organic solvent as a coating agent on these films. Depending on the purpose, it is also possible to use amorphous polyarylate (PAR).

(A-2) Crystalline heat-resistant film As crystalline heat-resistant film, polyethylene naphthalate (PEN), polyetheretherketone (PEEK)
Etc. can be used. Further, depending on the purpose, a glass transition point of about 1.0% at 90 ° C. and a heat shrinkage of 150 ° C.
It would also be possible to use polyphenylene sulfide (PPS).

(A-3) Polyimide Film, Aromatic Polyamide A heat-resistant label using a polyimide-based film as a base film has high heat resistance and is currently marketed by several companies.
Aromatic polyamide is generally called aramid,
Heat resistant paper made by using a paper machine with a fiber having a paraphenylene group and a fiber having a metaphenylene group (for example, DuPont Teijin Advanced Paper Co., Ltd.)
(Trade name, NOMEX). However,
Heat-resistant paper has poor surface smoothness and a large elongation due to humidity in the air, and its use as a heat-resistant label is limited.

(A-4) In summary, it is desirable to use polysulfone, polyethersulfone, polyetherimide, polyethylene naphthalate, polyetheretherketone, or polyimide as the base film. Depending on the application, amorphous polyarylate, polyphenylene sulfide, or aromatic polyamide can also be used.

(B) Heat-resistant surface coat layer As the heat-resistant surface coat layer, for example, a surface white coating agent for unon labels manufactured by Unon Co., Ltd. can be used.
The heat-resistant surface coat layer needs to have a property that enables clear printing and withstands heat treatment. The materials are not limited to those described above as long as they satisfy this condition. For example,
A white coat layer is often used for printing black ink, but other colors such as yellow, blue, and pink can also be used. For printing with white ink, a dark color such as black can be used.

(C) Heat-Resistant Coat Layer on Back Side The newly provided heat-resistant coat layer on the back side of the base film preferably has the following characteristics.

(A) In a heat treatment at 260 ° C. for 5 to 60 seconds, heat shrinkage is small. In order to enable reliable reading of a bar code or the like, it is desired that heat shrinkage be small.

(B) Good adhesion to the base film at room temperature and 260 ° C. for 5 seconds to 60 seconds. It is assumed that the heat-resistant coat layer on the back surface is in close contact with the base film. Desirable adhesion is J
IS K5400, 8.5 It is desirable that the score is 6 points or more according to the grid adhesion method.

(C) In a heating state at 260 ° C., there is no extreme softening such as a semi-molten state. If the softening is large, expansion and contraction of the base film at high temperatures cannot be suppressed. Generally, a thermoplastic resin cannot satisfy this condition.

The resins having the above qualities include (1)
Epoxy resins, (2) copolymers of silicone resins and other resins, and (3) thermosetting resins.

The epoxy resin can be cured at room temperature with the addition of a curing agent such as polyamine, and can be cured by heating. Also, shrinkage at high temperatures can be suppressed by using the filler together.

Although the varnish-like silicone resin has excellent heat resistance, the silicone resin lacks the suitability of (c), so care must be taken when using it alone. As the silicone resin copolymer, silicone acrylic, silicone polyester, silicone epoxy and the like are useful.

As the thermosetting resin, melamine resin, urea resin, phenol resin and resorcinol resin can be used. These resins have very high rigidity after curing, but have a large heat shrinkage at 260 ° C. Therefore, these resins are desirably mixed with other resins.

(D) Filler Added to Heat-Resistant Coating Layer By adding a filler to the resin, the rigidity can be further increased. As such a material, silicon oxide, aluminum oxide (alumina), titanium oxide, or the like can be used. In the case of these materials, those having a large average particle size are more effective.

In the case of a filler having a high hardness, there is a problem that the blade of the die is worn when the product is processed with the blade of the die.

When selecting a resin having rigidity, selecting a filler having a high aspect ratio is effective for improving rigidity. For example, kaolinite, montmorillonite, sericite, fine mica (particle size 0.3 to 30 μm)
Use of m) or the like is effective in improving rigidity. Also,
These fillers also have the effect of suppressing thermal shrinkage of the resin.

More preferable fillers having the effect of suppressing the thermal expansion and contraction of the resin are whisker-like fillers. As the whisker-like filler, for example, potassium titanate (for example, manufactured by Otsuka Chemical Co., Ltd.), aluminum borate (for example, manufactured by Teika Co., Ltd.) or the like can be used. Aluminum borate has an extremely low linear expansion coefficient in the fiber axis direction, for example, 2.6 × 10 ^−6, and is effective in suppressing thermal expansion and contraction of the resin.

By providing a heat-resistant surface coat layer on the surface of the base film and providing a heat-resistant coat layer on the back surface,
By balancing the performance of both coat layers, the characteristics (eg, thermal expansion and contraction) of the base film can also be suppressed.

Hereinafter, more specific examples will be described.

Example 1 (1) As a material for a heat-resistant coat layer provided on the back surface of a base film,

[0050]

[Table 1] Butylated melamine resin (Super Beckamine, J-820-60, manufactured by Dainippon Ink and Chemicals): 100 parts by weight Natural kaolin clay: 30 parts by weight Toluene: 50 parts by weight

Is uniformly dispersed by a ball mill and filtered through a 200 mesh stainless screen.

(2) A polyimide film (Kapton 100H, 25 μm (t), manufactured by Toray Dupont Co., Ltd.) was used as a base film, and a heat-resistant coating agent manufactured by Unon Giken Co., Ltd. (surface white coat for Unons label) was applied to the surface. And dried for 2 minutes at 170 ° C. The thickness after drying is about 1
It was 5 μm.

(3) On the back surface of the base film, (1)
After drying, the filler-mixed resin layer prepared above is applied so as to have a thickness of 15 μm, and dried and cured at 170 ° C. for 3 minutes.
Thus, a sample E is prepared.

For comparison, a sample P without the backside heat-resistant coating layer is also prepared.

(4) Pressure-sensitive adhesive layer

[0056]

[Table 2] B828R (manufactured by Harima Chemicals, Inc.): 100 parts by weight B82-240 (manufactured by Harima Chemicals, Inc.) Isocyanate crosslinking agent: 1.5 parts by weight

The mixture was coated on a glass release paper 80 g / m ² and a silicone release paper on one side by a comma coater method.
It is dried at 0 ° C. for 2 minutes, and bonded to the back side of the base film of the two types of sample (3).

The thus prepared pressure-sensitive adhesive sheet is aged at room temperature for about 10 days.

(5) Sample 2 prepared as described above
The seed is machined into the shape of a continuous label where the dimensions of a single heat-resistant label are 5 mm x 50 mm.

(6) Printing was performed on the label prepared by the above-described process under the following conditions, and the suitability of the auto labeler was examined.

Printing conditions: Printer: DP1300VZ (manufactured by Oaks Co., Ltd.) Ribbon: B110C (manufactured by Ricoh Co., Ltd.) The sample P without the heat-resistant coating layer on the back surface of the base film can protrude from the release paper. And the auto labeler suitability was rejected.

In the sample E having the heat-resistant coat layer provided on the back surface of the base film, the label could be completely protruded, and the automatic sticking process could be performed using an auto labeler. The Taber stiffness of sample E was about 1.1 g.
f · cm.

Example 2 As compared with Example 1, the material of the base film, the material of the heat-resistant coat layer on the back surface of the base film, the material of the adhesive layer, and the like were changed.

(1) Polyetherimide (Superio UT, F type Mitsubishi Plastics, Inc.)
Co., Ltd.), a 25 μm (t) film, and a heat-resistant coating agent manufactured by Unon Giken Co., Ltd.
After drying for 2 minutes, a white coat layer having a dry thickness of about 15 μm is obtained.

(2) As a material of the heat-resistant coat layer provided on the back surface of the base film,

[0066]

X (parts by weight) Y (parts by weight) Epoxy resin (Hypon No. 3000, manufactured by Hitachi Chemical Co., Ltd.): 100 100 Titanium oxide (JA-1, manufactured by Teika Co., Ltd.): 10 10 Mica (M-400, manufactured by Repco Corporation): 040 Ethyl acetate: 60 217

The above materials are uniformly dispersed by a homomixer.

(3) On the back surface of the base film, (2)
Are applied, and dried at 150 ° C. for 3 minutes to be cured. The thickness after drying is about 25 μm. For comparison, Sample Z without the backside heat-resistant coating layer was used.
Also prepared.

(4) The following materials were prepared for the pressure-sensitive adhesive layer provided on the back surface of the base film.

[0070]

Table 4 SK1306 (manufactured by Soken Chemical Co., Ltd., acrylic adhesive): 100 parts by weight L-45 (manufactured by Soken Chemical Co., Ltd., isocyanate crosslinking agent): 1.5 parts by weight

After thoroughly stirring the mixture of (3), the mixture was applied to the silicone release agent side of a 25 μm (t) polyester film release film by a roll coater, dried at 100 ° C. for 2 minutes, and the coated surface of (3) Paste. This adhesive sheet is aged at 40 ° C. for 4 days.

(5) The pressure-sensitive adhesive sheet prepared in (4) is applied as a label sheet having a machine direction (MD) direction of 10 mm and a cross direction (CD) direction of 50 mm by a roller at a pressure of about 2 kg on a commercially available glass epoxy plate. . Then, what was left at room temperature for 24 hours or more is used as a sample.

(6) The above sample (5) was placed in a muffle furnace (manufactured by Isuzu Seisakusho) which had been kept at a constant temperature of 260 ° C. in advance.
After heating for 2 to 3 minutes and returning to room temperature, the dimensional change was measured. The stiffness of each sample was also measured.

[0074]

[Table 5] Dimensional change (%) Dimensional change (%) Dimensional change (%) Stiffness (260 ° C × 15 seconds) (260 ° C × 30 seconds) (260 ° C × 3 minutes) (gf · cm) X: CD + 0 .1 +0.1 +1.6 MD -0.2 -0.2 -0.8 1.0 Y: CD +0 +0 +1.3 MD -0 -0.6 1.1 Z: CD +0.2 +0.3 +3.0 MD -0.5 -0.7 -1.3 0.2

(7) Each of the prepared samples was tested by an auto labeler. As a result, the samples X and Y were completely protruded, and the automatic application was smoothly performed. However, in sample Z, automatic application was not possible.

Considering these results, it is understood that the Taber stiffness is desirably about 1.0 gf · cm or more. If the Taber stiffness is less than about 1.0, there is a high possibility that the automatic labeling by the auto labeler will fail.

The present invention has been described in connection with the preferred embodiments.
The present invention is not limited to these. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

[0078]

As described above, according to the present invention,
A heat-resistant label capable of suppressing an increase in manufacturing cost and enabling automatic application by an auto labeler is provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating a configuration of a heat-resistant label according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view for explaining the operation of the auto labeler.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printer head 2 Heat-resistant label 3 Release paper 4 Wedge-shaped bending member 5 Vacuum suction tentacle 21 Base film 22 Surface heat-resistant coat layer 23 Pressure-sensitive adhesive layer 24 Back heat-resistant coat layer

Claims (5)

[Claims] 1. A base film formed of a material having no melting point or a material having a glass transition point of 110 ° C. or higher, and a surface coat layer provided on an upper surface of the base film and suitable for printing or printing. An adhesive layer provided on the lower surface of the base film, and a heat-resistant coat layer formed of a resin or a resin and a filler provided between the lower surface of the base film and the adhesive layer; A heat-resistant label with heat resistance of at least 5 seconds. 2. The heat-resistant label according to claim 1, wherein said base film has a thickness of about 25 μm to about 50 μm. 3. The heat-resistant coating layer contains a resin and a filler having an adhesion of 6 points or more by an adhesive grid method after heat treatment to the base film.
Heat-resistant label described. 4. The heat-resistant film according to claim 1, wherein the heat-resistant label has a Taber stiffness of about 1.0 or more. 5. The heat-resistant label expands and contracts by 0.5% in cross-direction when heated at 260 ° C. for 30 seconds.
The heat-resistant label according to any one of claims 1 to 4, wherein the heat-resistant label is less than.