JPH07156337A - Separator - Google Patents

Abstract

PURPOSE:To obtain a separator of which the speed dependence of a peeling force is small and which is excellent in the adhesion to an adhesive agent, while making use of the advantage of a low-temperature forming property of a release treatment layer constituted of a hardened film of ionizing radiation- setting type silicone. CONSTITUTION:A separator which is constructed by having, on one or both surfaces of a supporting base, a release treatment layer constituted of a hardened film of ionizing radiation-setting type silicone having two or more functional groups each constituted of an acryloyl group or/and a methacryloyl group, in a molecule, and of which a 180-degree peel value in regard to an adhesive surface in the case of a peeling speed of 0.3m/min. is 0.5 to 10 times larger than the one in the case of the peeling speed of 60m/min. According to this constitution, a positional slippage hardly occurs at the time of a low-speed operation such as positioning of a label, peeling from the adhesive surface can be executed at a high speed by a small force, an adhesive agent can be applied with excellent adhesion and the adhesive surface being smooth and excellent in an adhesive force can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separator which exhibits good adhesion to an aqueous emulsion type or organic solvent solution type adhesive and is suitable for forming an adhesive tape or a label.

[0002]

2. Description of the Related Art Conventionally, as a separator for temporarily adhering and protecting an adhesive surface of an adhesive tape substrate, a release sheet of a label, a light-shielding film or the like, a support substrate made of paper or a polymer film is ionizable. It has been proposed to provide a release treatment layer made of a cured film of radiation-curable silicone (JP-A-64-80525, JP-A-3-686).
70, JP-A-4-85027). this is,
It enables the formation of a silicone-based cured film at low temperatures by ionizing radiation, and relaxes the heat resistance of the supporting base material required in the case of conventional condensation reaction type or addition reaction type thermosetting silicones. .

However, any separator using conventional ionizing radiation-curable silicone has a problem that the peeling force (force required for peeling from the adhesive surface) has a large speed dependency. That is, in the conventional separator, the peeling force has been reduced by weakening the affinity with the adhesive surface, but in that case, although the reason is unknown, the peeling force greatly differs at the peeling speed and the peeling force increases as the peeling speed increases. Becomes larger,
Therefore, when the separator is temporarily attached and subjected to precision processing, there is a problem in that misalignment and floating occur between the separator and the adhesive surface. In addition, there is a problem in that the adhesiveness with the adhesive is poor and foaming or floating occurs on the formed adhesive surface when an adhesive tape, a label or the like is manufactured.

[0004]

DISCLOSURE OF THE INVENTION The present invention takes advantage of the low-temperature formability of a release treatment layer composed of a cured film of ionizing radiation-curable silicone, has a small speed dependence of the release force, and is used as an adhesive. The task is to develop a separator with excellent adhesion.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a support substrate having a release treatment layer comprising a cured film of an ionizing radiation curable silicone having two or more functional groups consisting of an acryloyl group and / or a methacryloyl group in the molecule. And the 180 degree peel value on the adhesive surface at a peeling speed of 0.3 m / min is 0.5 to 10 times that at a peeling speed of 60 m / min. A characteristic separator is provided.

[0006]

By using an ionizing radiation-curable silicone having two or more functional groups consisting of an acryloyl group and / or a methacryloyl group in the molecule, it is possible to form a release treatment layer comprising the cured film at a low temperature, and to perform the release treatment. The layer has a property that the speed dependence of the peeling force is small due to the cross-linking structure based on the functional group and has excellent adhesiveness to the adhesive surface, and the peeling force satisfies the above speed dependence, and thus the pressure-sensitive adhesive tape or label Misalignment is unlikely to occur during low-speed work such as positioning, movement, stacking, etc., while work such as peeling can be easily performed with low resistance (peeling force) during high-speed work such as when peeling the separator from the adhesive surface. It can be a separator.

Further, it exhibits good adhesion to an aqueous emulsion type or organic solvent solution type adhesive, and when an adhesive tape or label is produced by applying an adhesive on such a separator, the adhesive surface formed is It has excellent adhesive strength because it can form a smooth adhesive surface that is unlikely to cause foaming or floating.

[0008]

Examples of constituent elements of the present invention: The separator of the present invention has a release treatment layer comprising a cured film of an ionizing radiation-curable silicone having two or more functional groups consisting of an acryloyl group and / or a methacryloyl group in a molecule as a supporting group. Having one or both sides of the material, the 180 degree peel value for the adhesive surface at a peeling speed of 0.3 m / min is 0.5 to 10 times that at a peeling speed of 60 m / min. Is.

As the ionizing radiation-curable silicone,
Appropriate ones having two or more functional groups consisting of an acryloyl group and / or a methacryloyl group which can be cured (crosslinked) by ionizing radiation in the molecule can be used. Therefore, the silicone may contain an organosiloxane having an appropriate organic group such as an alkyl group having 1 to 20 carbon atoms such as a methyl group, a cycloalkyl group, an aryl group or an aralkyl group, but ionizing radiation curing. The functional group having acryloyl group and / or methacryloyl group is preferable as the functional group.

The ionizing radiation-curable silicone which can be preferably used is a silicone oligomer having a number average molecular weight of 500 to 5000 and having 3 to 20 functional groups in the molecule.
50 parts by weight, especially 20 to 40 parts by weight, and a number average molecular weight of 2000 to 300 having 2 to 20 functional groups in the molecule.
95 to 50 parts by weight of silicone oligomer of 00, especially 8
It is a mixture with 0 to 60 parts by weight.

As the supporting substrate, a suitable thin sheet such as a paper substrate, a plastic laminated paper, a cloth, a plastic laminated cloth or a plastic film is used, and particularly, for example, high quality paper, glassine paper, kraft paper, parchment paper and the like. A paper base material, a film obtained by laminating one or both surfaces thereof with a polyolefin such as polyethylene, a film made of a polymer such as polyethylene terephthalate, polypropylene, polyethylene, polyvinyl chloride, polyimide, cellophane can be preferably used.

In the present invention, since a curing treatment can be carried out at a low temperature by ionizing radiation, a separator using a film made of a polyolefin such as polyethylene having a crystal melting temperature of 120 ° C. or less as a supporting substrate can be easily produced at a high speed.
Such a polyolefin film or a polyolefin laminated paper has a low rigidity and is less likely to cause noise when peeled,
It is useful industrially because its texture is soft.

The thickness of the supporting substrate may be appropriately determined according to the purpose of use and the like, and is generally about 5 to 200 μm. In the case of the film or laminate layer made of polyolefin having a crystal melting temperature of 120 ° C. or less, the thickness is preferably 5 to 20 μm in view of its low rigidity and the like.

To form the separator, for example, one side or both sides of the supporting substrate is coated with ionizing radiation-curable silicone using an appropriate device such as a squeeze coater, and the coating layer is irradiated with ionizing radiation. It can be carried out by a method such as curing treatment. The coating amount of ionizing radiation-curable silicone, 0.05~5g / m ^2, preferably especially 0.1 to 3 g / m ^2. If the coating amount is less than 0.05 g / m ² , the peeling force becomes large and the stability becomes poor.
Coatings exceeding 5 g / m ² produce no practical benefit.

In coating the above-mentioned ionizing radiation-curable silicone, a photoinitiator may be used in combination, and solventless coating without diluting with an organic solvent is preferable from the viewpoint of working environment and the like. However, this does not exclude dilution coating with an organic solvent. As the ionizing radiation for the curing treatment, those having a wavelength of 400 nm or less, for example, ultraviolet rays from a medium-pressure or high-pressure mercury lamp, electron rays, gamma rays, etc. are preferable.

The separator of the present invention can be used for various purposes such as temporarily adhering to an adhesive surface to protect it, for example, a base material or label of an adhesive tape, a light-shielding film, a release sheet for a double-sided adhesive tape or the like. it can.

[0017]

【Example】

Example 1 A silicone oligomer having 3 to 20 acryloyl groups and / or methacryloyl groups in a molecule (A type) and a number average molecular weight of 1400 (manufactured by Shin-Etsu Chemical Co., Ltd., the same applies hereinafter).
30 parts (weight part, the same applies hereinafter) and the functional group in the molecule are 2
A mixture of 70 parts of (B type) silicone oligomer having a number average molecular weight of 5000 and 70 parts was laminated on one side of kraft paper with a squeeze coater to a thickness of 20 μm.
Was applied to the low density polyethylene layer of No. ^{2 at} a rate of 2.0 g / m ² and the low voltage electron beam accelerator (CB-1 manufactured by ESI)
50), absorbed dose 30 kGr with accelerating voltage of 165 kv
It was irradiated with y and cured to obtain a separator.

Example 2 A mixture of 50 parts of a type A silicone oligomer having a number average molecular weight of 1200 and 50 parts of a type B silicone oligomer having a number average molecular weight of 4000 was 0.5 g / m ^{2 on} one side of a low density polyethylene film having a thickness of 20 μm. The coating was applied at the ratio of, and curing treatment was carried out according to Example 1 to obtain a separator.

Example 3 A mixture of 20 parts of a type A silicone oligomer having a number average molecular weight of 2000 and 80 parts of a type B silicone oligomer having a number average molecular weight of 4000 was added to a photoinitiator (Darocur 11
73, manufactured by Ciba-Geigy Co., Ltd.) and mixed to a thickness of 1
A 2 μm polyethylene terephthalate film was coated on one side at a rate of 0.6 g / m ² , and was irradiated with an ultraviolet irradiator (F-450 manufactured by Fusion Systems Co., Ltd.) to be cured to obtain a separator.

Example 4 1 part of a photoinitiator (Irgacure 184, manufactured by Ciba-Geigy) was mixed with a mixture of 40 parts of A type silicone oligomer having a number average molecular weight of 1200 and 60 parts of B type silicone oligomer having a number average molecular weight of 12000. 0.8g / m ^{2 on} one side of 12μm thick polyethylene film
And a curing treatment according to Example 3 to obtain a separator.

Example 5 A mixture of 20 parts of a type A silicone oligomer having a number average molecular weight of 3000 and 80 parts of a type B silicone oligomer having a number average molecular weight of 4000 was applied to one side of a stretched polypropylene film having a thickness of 20 μm in an amount of 1.0 g / m ² . The coating was performed at a ratio and the curing treatment was performed according to Example 1 to obtain a separator.

Example 6 A mixture of 30 parts of A-type silicone oligomer having a number average molecular weight of 1000 and 70 parts of B-type silicone oligomer having a number average molecular weight of 7,000 was applied to one side of glassine paper having a basis weight of 98 g / m ² at 1.5 g / m 2. Example 1 after coating at a ratio of ²
A curing treatment was performed according to the above procedure to obtain a separator.

Example 7 A mixture of 20 parts of a type A silicone oligomer having a number average molecular weight of 1400 and 80 parts of a type B silicone oligomer having a number average molecular weight of 5500 was mixed with 1 part of Darocur 1173 and laminated on one side of kraft paper. A low-density polyethylene layer having a thickness of 20 μm was applied at a rate of 2.0 g / m ² and cured according to Example 3 to obtain a separator.

Comparative Example 1 Addition reaction type silicone (KS-77 manufactured by Shin-Etsu Chemical Co., Ltd.)
2) 1 part by weight of a curing catalyst (Cat-PL-3) was added to 100 parts to prepare a 1 wt% heptane solution, and 0.5 g / m ² was applied to a low-density polyethylene layer having a thickness of 20 μm laminated on one side of kraft paper. And was cured at 150 ° C. for 60 seconds to obtain a separator.

Comparative Example 2 The same heptane solution as in Comparative Example 1 was applied to one side of the same polyethylene film as in Example 2 at a rate of 0.1 g / m ² and cured at 60 ° C. for 10 seconds to obtain a separator. .

Comparative Example 3 A separator according to Example 1 in JP-A-64-80525 was obtained.

Comparative Example 4 A separator according to Example 1 in JP-A-3-68670 was obtained.

Comparative Example 5 A separator according to Example 2 in JP-A-4-85027 was obtained.

Evaluation Test The following characteristics of the separators obtained in Examples and Comparative Examples were examined. Curable Rubbing the release treatment layer of the separator with a finger, based on the cloudiness and transfer of silicone to the finger, if there is no cloudiness or transfer, ○,
A case was evaluated as x.

Smoothness An acrylic pressure-sensitive adhesive (SK-801B manufactured by Soken Kagaku Co., Ltd.) is applied on the release-treated layer of the separator and dried to form a pressure-sensitive adhesive layer having a thickness of 50 μm. Was visually observed and evaluated as ◯ when there was no foaming and the surface was smooth, and as x when the surface was uneven due to foaming or the like.

Peel force ratio 20 ° C., 65% RH, under the surface of the separator treated release layer,
An adhesive tape having a width of 50 mm and having a 50 μm-thick adhesive layer made of the acrylic adhesive on a polyester film is placed via the adhesive layer, and a load of 50 g / cm ² is applied thereon, and the temperature is 20 ° C. Leave for 48 hours. Then, the load is released, and the product is left for 2 hours at 20 ° C. and 65% RH, and an adhesive tape of 0.3 m / min (Tensilon tensile tester, manufactured by Orientec Corporation) or 60 m / min (high speed) is obtained. The peeling force was measured by peeling at a speed of a peeling tester (manufactured by Tester Sangyo Co., Ltd.) (18
The peeling force ratio at low speed / high speed was obtained.

The above results are shown in Table 1.

[Table 1]

[0033]

EFFECTS OF THE INVENTION According to the separator of the present invention, the peeling force has a small speed dependence and is excellent in adhesion to the adhesive surface, and is less likely to be displaced during low speed work such as label positioning, and smaller than the adhesive surface at a high speed. It can be peeled off by force. Further, it is possible to form a pressure-sensitive adhesive tape or the like which can be coated with a pressure-sensitive adhesive with good adhesiveness and is less likely to cause foaming or floating when dried and has a smooth surface and a pressure-sensitive adhesive surface having excellent adhesive strength. Also, it can be formed at a low temperature by ionizing radiation, and its cured film has excellent adhesion to a supporting substrate and is difficult to transfer to an adhesive surface.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masayoshi Natsume 1-2-1, Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation

Claims (4)

[Claims] 1. A release treatment layer comprising a cured film of an ionizing radiation-curable silicone having two or more functional groups consisting of an acryloyl group and / or a methacryloyl group in a molecule is provided on one side or both sides of a supporting substrate. When the peeling speed is 0.3 m / min, the 180 degree peel value on the adhesive surface is 6
0.5-10 of that at 0 m / min peeling speed
Separator characterized by being doubled. 2. A cured film of ionizing radiation-curable silicone has 5 to 50 parts by weight of a silicone oligomer having a number average molecular weight of 500 to 5000 having 3 to 20 functional groups in the molecule and the functional group in the molecule. Silicone oligomer 9 having 2 to 20 number average molecular weight of 2000 to 30000
The separator according to claim 1, which comprises a cured film of a mixture of 5 to 50 parts by weight. 3. The separator according to claim 1, wherein the supporting substrate comprises paper and / or a polymer film. 4. The polymer film has a crystal melting temperature of 120 ° C.
The separator according to claim 3, which is made of the following polyolefin and has a thickness of 5 to 20 µm.