JP2006335044A - Release paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a release paper with a release agent layer capable of being subjected to an antistatic treatment by a comparatively simple method and not undergoing deterioration in release property even if the paper is subjected to the antistatic treatment. <P>SOLUTION: The release paper comprises an antistatic agent layer made of a siloxane type antistatic agent and formed on one face of a substrate and the release agent layer such as a silicone or the like formed on the antistatic agent layer. In the releas paper, the releasing paper provided with the antistatic agent layer independently has the antistatic agent layer having a thickness of, preferably, 0.01-10 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a release paper, and more particularly to an antistatic release paper.

  Plastics have been developed and used as electrical insulating materials, but in recent years, they are used everywhere in building materials, packaging materials, release papers and the like due to their characteristics such as light weight, toughness, and workability.

  While the high electrical insulation and low moisture absorption of plastic are advantageous properties of plastics used in various fields, the static electricity generated on the surface due to this high electrical insulation and low moisture absorption causes various obstacles. May bring.

  Although the generation mechanism of this static electricity has not been fully elucidated yet, it is explained by the electric double layer, electrons, ions, contact potential difference, etc., but the main causes of charging are frictional charging and peeling. Charging is known.

  When the two materials are rubbed against each other, one of them is positively charged and the other is negatively charged. The peeling charge is one in which two materials are positively separated when they are separated after contact. The other is negatively charged.

  In various plastic films that are wound up in the form of rolls during production, storage, transportation, etc., and used by being pulled out of the roll-up winding state during use, friction occurs in the process of being wound up in the form of rolls, Moreover, since it peels when it pulls out from the state of a roll, it can be said that it is always in the state which can produce the above-mentioned friction charge and peeling charge.

  If such charging occurs, dirt or dust in the air is adsorbed to contaminate or damage the product, and it becomes an obstacle to printing. In some cases, the work efficiency is reduced, and the worker is shocked by the discharge, and an accident such as a fire may occur.

  For this reason, various methods for preventing charging that cause such troubles have been proposed in the past, and it is not related to antistatic technology for release paper. There are a method for suppressing the generation of electric charge by applying an oil agent to the surface, a method for increasing leakage of electric charge, a method for neutralizing a charged body by corona discharge or the like, and a method for eliminating static electricity.

  Among them, the method of increasing the charge leakage is to prevent charging by reducing the surface resistance of the plastic film. As an example, various surfactants are applied as antistatic agents to the plastic film by spraying, dipping, or the like. The antistatic agent film is formed on the surface layer of the plastic film, thereby reducing the surface resistance and increasing the leakage of charges.

  However, since such a surfactant-based antistatic agent is generally water-soluble, the antistatic effect is lost when touched with water, and since the adhesion with the lower layer is poor, the antistatic agent layer is caused by friction. Easily falls off. In addition, surfactants are small organic molecules that may be altered or migrated by external factors and rapidly lose their antistatic effect in a matter of weeks.

  Therefore, in order to compensate for the drawbacks of surfactant antistatic agents that are prone to peeling and lose their antistatic effect in a relatively short period of time, anionic, cationic, nonionic, amphibian, etc. A surfactant-based antistatic agent is kneaded into plastic (Non-patent Document 1).

  When a surfactant-based antistatic agent is kneaded into the plastic film in this way, the surfactant-based antistatic agent that originally has little compatibility with the plastic oozes out on the surface of the product and becomes a thin layer. The surface resistance is lowered by making the surfactant, and many of these surfactants are hygroscopic, and by absorbing moisture, the surface resistance is further lowered, thereby improving the antistatic effect. However, when kneading into a plastic, there is a problem that the antistatic agent may be thermally decomposed and may not exhibit an antistatic function.

  Furthermore, in addition to the surfactant-based antistatic agent described above, there is an antistatic agent using a siloxane bond (referred to as “siloxane-based antistatic agent” in the present invention) (Patent Document 1), and the surface of the plastic absorbs moisture. By forming a film of a siloxane-based antistatic agent having a property, the surface resistance of the product is lowered and the antistatic effect is exhibited.

Prior art document information of the present invention includes the following.
Published by Plastics Age Co., Ltd. JP-A-6-172678

  The release paper that is the subject of the present invention is a silicone in which a release agent layer having excellent release properties is formed on the surface of a substrate such as paper or a plastic film, and is generally used as this release agent layer. (Silicon resin) is easy to be charged without leakage of charge due to the main chain bond and three-dimensional structure of silicon.

  For this reason, the release paper on which such a silicone release agent layer is formed is charged by friction during manufacture, winding, etc., as in the case of the above-mentioned general plastic film, and is also peeled off when the wound-up paper is pulled out. Since charging is performed by charging, various adverse effects associated with charging occur.

  On the other hand, in such a release paper, it is planned to use an adhesive sheet or the like later on the formed release agent layer. If the release agent layer does not exhibit a high releasability with respect to the adhesive layer such as an adhesive sheet even after the antistatic treatment is performed, the release sheet cannot be used.

  The above-mentioned release agent such as silicone has a very low surface tension, that is, high release properties are obtained by utilizing a unique surface / interface property that it is difficult to wet. Regardless of whether an antistatic agent based on siloxane or siloxane is used, if the surface of the release agent layer that exhibits such characteristics is covered with an antistatic agent coating, such a release agent layer Therefore, the surface / interface characteristics will not be exhibited.

  In addition, there are release papers that use surfactant-based antistatic agents, but when a surfactant-based antistatic agent film with low adhesion is formed, the antistatic agent adheres to the adhesive. There is a risk of affecting the adhesive strength of the adhesive.

  As described above, each of the various known antistatic methods described above is effective as an antistatic agent for a general plastic film, but this is applied to a release paper having a release agent layer formed of silicone or the like. It cannot be applied as it is. Therefore, at present, there is no effective antistatic method for release paper.

  Therefore, the present invention has been made for the purpose of eliminating the above-mentioned drawbacks of the prior art, and it is possible to prevent the release paper having a release agent layer from being charged by a relatively simple method. It is an object of the present invention to provide a release paper that does not impair the adhesiveness or peelability of an adhesive or the like to be bonded later even when proper antistatic is performed.

  Another object of the present invention is to provide a release paper that is prevented from being charged by reducing the surface resistivity of the release agent layer itself provided on the release paper.

  In order to achieve the above object, the release paper of the present invention comprises an antistatic agent layer formed of a siloxane antistatic agent on at least one surface of a substrate, and a release agent layer formed on the antistatic agent layer. (Claim 1; see FIG. 1).

  Another release paper of the present invention has a release agent layer on at least one side of the substrate, and an antistatic agent formed on the surface opposite to the surface on which the release agent layer is formed with a siloxane antistatic agent. It has an agent layer (Claim 2; see FIG. 2).

  Furthermore, another release paper of the present invention has a release agent layer formed of a release agent to which a siloxane-based antistatic agent is added on at least one side of a substrate (see claim 3; see FIG. 3). .

  Among the release papers, in the release paper having an independent antistatic agent layer, it is preferable that the thickness of the antistatic agent layer is 0.01 to 10 μm.

  If the thickness is less than 0.01 μm, there is a possibility that antistatic performance may not be obtained, and the upper limit can be set in terms of manufacturing cost.

  Moreover, in the release paper provided with the release agent layer to which the antistatic agent is added, a siloxane antistatic agent is added in a ratio of 1 to 25 by weight with respect to the release agent 100. (Claim 5).

  Due to the characteristics of the antistatic agent, if the addition amount is less than 1, there is a possibility that the antistatic performance does not come out, and if the addition amount is 25 or more, there is no performance disadvantage, but in terms of cost effectiveness, Is set.

  In addition, the said base material is good also as what uses what the sealing process was performed to the lamination | stacking surface as needed (Claim 6).

  Moreover, it is preferable to use a silicon resin-based release agent as the release agent for forming the release agent layer.

  In the release paper of the present invention having the above-described configuration, it is possible to provide a release paper that is prevented from being charged without deteriorating the release property of the release agent layer regardless of the configuration. I was able to.

  In particular, in a release paper having a configuration in which a layer of a siloxane antistatic agent is formed in a lower layer of a release agent layer and a release agent layer formed by a release agent added with a siloxane antistatic agent, It became possible to reduce the surface specific resistance value of the release agent layer itself without impairing the release property of the release agent layer.

  Moreover, it can be said that the antistatic effect is exhibited even when a silicone layer as an insulating layer is laminated on the antistatic layer, the effect obtained for the first time by the present invention.

  Next, embodiments of the present invention will be described below.

Embodiment 1
As shown in FIG. 1A, the first release paper of the present invention comprises a siloxane-based antistatic agent layer (antistatic agent layer) formed on at least one surface of a substrate, and the antistatic agent layer. A release agent layer (release agent layer) formed is provided.

  As the base material, various materials such as various papers, resin films and sheets, which are used as a base material in known release paper, can be used. It is preferable to use a material that has been subjected to a sealing treatment by applying a sealing agent to the laminated surface of the antistatic agent layer, which will be described later (see FIG. 1B), and the sealing formed by this sealing treatment. The above-mentioned antistatic agent layer is formed on the agent layer.

  In this way, when the base material is, for example, paper, by performing such a sealing treatment, the antistatic agent penetrates into the base material and the amount of the antistatic agent applied increases. Can be prevented.

  As the sealing agent, it is possible to use various known materials generally used as sealing agents, such as resins such as PE and PP, and resins added with mineral substances such as clay. It can apply | coat to the single side | surface or both surfaces of the paper which is a base material, and can form a sealing agent layer. In this embodiment, as an example, polyethylene (PE) is laminated to form a sealant layer.

  Next, when a sealant layer as described above is formed, a siloxane-based antistatic agent is applied directly on the sealant layer, for example, on a base material not provided with a sealant layer. The antistatic agent layer is formed by laminating by the above method.

  The siloxane antistatic agent used for forming the antistatic agent layer has some silanol groups in the siloxane network of the formed coating film by drying and curing after coating, and the siloxane having this silanol group The anti-static effect is generated by the water absorption of the net, and “Colcoat P” (trade name) manufactured by Colcoat Co., Ltd. can be used as an example.

The coating amount of the siloxane antistatic agent is 0.01 to 5 g / m ² , and the coating thickness is 0.01 to 10 μm, preferably 0.01 to 5 μm, more preferably 0.05 to 0.2 μm. Then, after coating on the substrate or the sealant layer, it is dried by heating at 80 to 130 ° C. for 15 seconds to 5 minutes.

  Since the antistatic agent alone cannot be used as a release agent on the antistatic agent layer thus formed, a release agent is further applied to form a release agent layer. As the release agent layer, in addition to silicone, a long-chain alkyl resin, a fluorine resin, or the like can be used. In the present embodiment, silicone is used.

As the silicone to be used, it is possible to use a straight type silicone varnish, modified silicone, etc., but in the present embodiment, a two-component type thermosetting silicone excellent in adhesion and workability is used, A coating amount of 0.1 to 3 g / m ² and a coating thickness of 0.1 to 3 μm, preferably 0.4 to 1 μm, are applied on the antistatic agent layer, and after coating, at 90 to 130 ° C. for 10 seconds to 1 Heated for minutes to dry.

  As a constituent material of the release agent layer, a platinum-based catalyst is added to the previous release agent in an amount of 0.5 to 2 (weight ratio) with respect to the release agent 100.

  As described above, in the embodiment described with reference to FIGS. 1A and 1B, the above-described antistatic agent layer, release agent layer, and, if necessary, only on one side of the base material Although it has been described that the agent layer is formed, for example, when the antistatic agent layer and the release agent layer are formed only on one side of the substrate, the above-mentioned sealing agent layer is formed on both sides of the substrate. [See FIG. 1C].

  When the release paper of the present invention is used as a release paper for transfer tapes and double-sided adhesive tapes, it has an antistatic agent layer on at least one side as shown in FIGS. 1 (D) to 1 (G). A release agent layer (a sealant layer as necessary) may be formed on both sides.

In the release paper of the present invention configured as described above, the surface specific resistance value of the release agent layer formed on the release paper was 10 ¹² to 10 ¹⁴ Ω.

Since the surface specific resistance value of the release agent layer formed directly on the substrate or via the sealant layer without providing the antistatic agent layer is 10 ¹⁶ Ω or more, the present invention By adopting the configuration, it was possible to greatly reduce and maintain the surface resistivity.

  In the release paper thus obtained, its peelability is not impaired, and the base material, the antistatic agent layer, the release agent layer (if a sealant layer is provided, further seals are provided). The adhesiveness between the agent layers is also good.

[Embodiment 2]
In the first embodiment, the example in which the surface specific resistance value of the release agent layer is reduced by providing the antistatic agent layer in the lower layer of the release agent layer has been described. Unlike Embodiment 1, the siloxane-based antistatic agent layer is provided on the surface of the release paper opposite to the release agent layer [FIGS. 2 (A) to 2 (C)]. .

The release paper formed in this way does not reduce the surface resistivity itself of the release agent layer, but the release agent layer and the antistatic agent layer are in contact with each other when the obtained release paper is rolled up. Therefore, the antistatic agent layer having a surface resistivity of 10 ⁸ to 10 ⁹ Ω can be prevented from being charged due to friction during winding and peeling due to peeling.

  Therefore, in the release paper of this embodiment, the release agent layer is formed only on one side of the release paper.

  In the release paper of the present invention formed as described above, the antistatic agent layer is formed on the base material (or the sealant layer) by using a siloxane-based antistatic agent for forming the antistatic agent layer. The bond is strong and stable, and it is possible to prevent the antistatic agent from being transferred to the surface of the release agent layer as in the case where a surfactant-based antistatic agent is applied.

  For this reason, it is also possible to suitably prevent a decrease in peelability caused by covering the surface of the release agent layer with the antistatic agent.

  In addition, about the formation material and formation method of each layer of the base material, the antistatic agent layer, the release agent layer, and the sealant layer formed as necessary, the same as in the above-described first embodiment and the same method Can be used.

[Embodiment 3]
Furthermore, in the present embodiment (Embodiment 3), a siloxane-based antistatic agent is added to the release agent that forms the release agent layer, whereby the surface specific resistance value of the release agent layer is reduced. It is characterized by a lowered point (see FIGS. 3A to 3F).

  In the release paper of this embodiment, the base material to be used and the formation of the sealing agent layer performed on the base material as necessary are the same as those described in the first embodiment, and the description thereof is omitted.

  As the release agent layer formed on the release paper of this embodiment, a mixture of 1 to 25 by weight with respect to the release agent and the antistatic agent 100 is used.

  Moreover, in the Example mentioned later, the platinum-type catalyst which accelerates | stimulates the hardening reaction of known silicone is added.

The coating amount of the release agent to which the siloxane antistatic agent is added is 0.1 to 3 g / m ² , the coating thickness is 0.1 to 3 μm, preferably 0.4 to 1 μm. And after apply | coating by thickness, it heated at the temperature of 90-130 degreeC for 10 second-1 minute, and was dried, and the release agent layer was formed.

The surface specific resistance value of the release agent layer of the release paper of the present invention formed as described above is 10 ¹³ Ω, and the surface specific resistance of 10 ¹⁶ Ω of the release agent layer formed by mixing the catalyst with silicone. The resistance value can be greatly reduced.

  And while the peelability of the release agent layer obtained in this way is not impaired, the adhesiveness with respect to a base material (or sealing agent layer) is also favorable.

  In the release paper of this embodiment, a release agent layer may be provided on both sides of the release paper as shown in FIG.

  Hereinafter, the results of the performance evaluation test of the release paper of the present invention will be described.

[Test Example 1] Configuration in which an antistatic agent layer is provided below the release agent layer (1) Sample
(1-1) Example 1
A polyethylene laminate is applied as a sealant layer on one side of the base paper, and a siloxane antistatic agent (manufactured by Kolcoat Co., Ltd .; trade name “Kolcoat P”) is applied onto this sealant layer using a Mayer bar. The coating was applied at 0.09 g / m ² and dried at a temperature of 105 ° C. for 30 seconds to form an antistatic agent layer.

On this antistatic agent layer, silicone (manufactured by Shin-Etsu Chemical Co., Ltd .; trade name “KS3502”) was applied at 0.5 g / m ² as a release agent (heavy release) and dried at a temperature of 105 ° C. for 30 seconds. To form a release agent layer.

(1-2) Example 2
The same as Example 1 except that silicone (manufactured by Shin-Etsu Chemical Co., Ltd .; trade name “KS847”) was used as the release agent (medium release).

(1-3) Example 3
The same as Example 1 except that silicone (made by Toray Dow Corning Co., Ltd .; trade name “LTC303E”) was used as the release agent (light release).

(1-4) Comparative Example 1
A polyethylene laminate was applied as a sealant layer on one side of the base paper, and a release agent layer was formed directly on this sealant layer (same as Example 1 except that no antistatic agent layer was formed).

(1-5) Comparative Example 2
A polyethylene laminate was applied to one side of the base paper as a sealing agent layer, and a release agent layer was formed directly on this sealing agent layer (same as Example 2 except that no antistatic agent layer was formed).

(1-6) Comparative Example 3
A polyethylene laminate was applied as a sealing agent layer on one side of the base paper, and a release agent layer was formed directly on this sealing agent layer (same as Example 3 except that no antistatic agent layer was formed).

(2) Evaluation method
(2-1) Evaluation of Release Agent Adhesiveness The release agent layer formed on the samples of Examples 1 to 3 was rubbed with finger pressure, and the removal of the release agent layer was visually confirmed.

  Further, the samples of Examples 1 to 3 were left in a humidified state of 40 ° C. and 90% Rh, and the adhesion state of the release agent layer with the passage of time was confirmed.

(2-2) Measurement of surface resistivity The surface resistivity of the release agent layer formed on the samples of Examples 1 to 3 was measured. The measurement conformed to JIS-K-6911.

(2-3) Peel load measurement

  The peel load was measured under the conditions shown in Table 1 above, and at the same time, the change of the peel load with the lapse of time after pasting was confirmed. As the aging condition, the sample was left until the measurement time in a state where no load was applied to 23 ° C. and 65% Rh, and peeling measurement was performed.

(2-4) Measurement of residual adhesive rate

  The residual adhesive rate was measured under the above conditions.

(3) Evaluation result The evaluation result performed by the above method is shown below.

(4) Discussion
(4-1) Release agent adhesion In any of Examples 1 to 3 in which heavy release, intermediate release, and light release agent were used, the release agent layer was not removed, and all adhered with high adhesion. It was confirmed that

  Moreover, in any of Examples 1 to 3, it was not possible to confirm a decrease in adhesion over time, and it was confirmed that a release agent layer was formed with good adhesion.

(4-2) Surface specific resistance value It became clear that the surface specific resistance was reduced to 1/1000 in Example 1 and 1/10000 in Examples 2 and 3, and siloxane-based charging was under the release agent layer. It was confirmed that the formation of the inhibitor layer is effective for preventing the release paper from being charged (increasing charge leakage on the surface of the release agent layer).

  Considering that the leakage of charge due to the siloxane antistatic agent is due to moisture absorption by the silanol group-containing siloxane network (adsorption of moisture in the air), the siloxane antistatic agent layer is only formed as a surface layer. Even if a siloxane-based antistatic agent layer is formed in the lower layer of the release agent layer as in the structure of the present invention, the surface resistivity of the release agent layer formed on the upper layer is considered to exert an antistatic effect. It is an unexpected effect that the value decreases significantly as described above.

(4-3) Peeling load and residual adhesive rate Comparative example not having an antistatic agent layer even in the release papers of Examples 1 to 3 in which a siloxane-based antistatic agent layer was formed in the lower layer of the release agent layer There was no increase in peel load compared to the release papers 1 to 3, and no difference in residual adhesion rate was observed.

  Therefore, it can be confirmed that the peelability of the release paper is not impaired even by adopting the configuration of the present invention, and the release paper of the present invention is antistatic without sacrificing the peelability of the release paper. It was confirmed that the effect can be obtained.

[Test Example 2] Configuration in which antistatic agent is mixed in release agent layer (1) Sample
(1-1) Example A polyethylene laminate was applied as a sealant layer on one side of a base paper, and a blend containing a silicone, a catalyst, and a siloxane antistatic agent in the weight ratio shown below on this sealant layer was Meyer. Using a bar, the coating was applied at a coating amount of 0.5 g / m ² and dried at a temperature of 105 ° C. for 30 seconds to form a release agent layer containing an antistatic agent.

(1-2) Comparative Example 4
A polyethylene laminate is applied to one side of the base paper as a sealing agent layer, and a release agent prepared by mixing silicone and a catalyst at a weight ratio of 100: 1 is applied onto this sealing agent layer using a Mayer bar. The film was applied at 5 g / m ² and dried at a temperature of 105 ° C. for 30 seconds to form a release agent layer.

  The product used by Shin-Etsu Chemical Co., Ltd .; brand name "KS-847" as a silicone, and the product name "PL50T" produced by Shin-Etsu Chemical Co., Ltd. as a catalyst are the same as Examples 4-6.

(2) Evaluation method
(2-1) Evaluation of Release Agent Adhesiveness The release agent layers formed on the samples of Examples 4 to 6 and Comparative Example 4 were rubbed with finger pressure, and the removal of the release agent layer was visually confirmed.

  Moreover, the samples of Examples 1 to 3 were left in a humidified state of 40 ° C. and 90% Rh, and the peeling state of the release agent layer with the passage of time was confirmed.

(2-2) Measurement of surface resistivity The surface resistivity of the release agent layers formed on the samples of Examples 4 to 6 and Comparative Example 4 was measured. The measurement conformed to JIS-K-6911.

(2-3) Peel load measurement Peel load measurement was performed under the conditions shown in Table 1 above.

(2-4) Measurement of residual adhesive rate The residual adhesive rate was measured under the conditions shown in Table 2 above.

(3) Evaluation result The evaluation result performed by the above method is shown below.

(4) Discussion
(4-1) Release Agent Adhesiveness In any of Examples 4 to 6, the release agent layer did not fall off and adhered with high adhesion in any case where a siloxane antistatic agent was added in any proportion. I was able to confirm.

  Moreover, in any of Examples 4 to 6, it was not possible to confirm a decrease in adhesion over time (one day), and it was confirmed that a release agent layer was formed with good adhesion.

(4-2) Surface Specific Resistance Value In any of Examples 4 to 6, it was revealed that the surface specific resistance was reduced to 1/100 of Comparative Example 4, and a siloxane-based antistatic agent was included in the release agent. It was confirmed that the addition of the layer was effective in preventing the release paper from being charged (increasing charge leakage on the surface of the release agent layer). It was also confirmed that the degree of decrease in the surface specific resistance value did not change depending on the difference in the amount of siloxane antistatic agent added.

(4-3) Peeling load and residual adhesion rate In Examples 4 to 6, the peeling load was almost the same as that of Comparative Example 4, and no difference was observed in the residual adhesion rate.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic explanatory drawing of the layer structure of the release paper demonstrated as Embodiment 1, (A), (B), (C) is the structure which formed the release agent layer in the single side, (D)-(G) is both sides A configuration in which a release agent layer is formed. It is a schematic explanatory drawing of the layer structure of the release paper demonstrated as Embodiment 2, (A) does not have a sealing agent layer, (B) has a sealing agent layer, (C) is release agent. The structure which provided the antistatic agent layer also in the lower layer of the layer is shown. It is a schematic explanatory drawing of the release paper demonstrated as Embodiment 3, (A) is a structure which does not have a sealing agent layer, (B), (C) is a structure which has a sealing agent layer, (D)-(F ) Is a structure in which a release agent layer is provided on both sides.

Claims (6)

  A release paper comprising an antistatic agent layer formed of a siloxane-based antistatic agent and a release agent layer formed on the antistatic agent layer on at least one side of a substrate.   A release paper comprising a release agent layer on at least one surface of a substrate and an antistatic agent layer formed of a siloxane-based antistatic agent on a surface opposite to the surface on which the release agent layer is formed. .   A release paper comprising a release agent layer formed of a release agent to which a siloxane antistatic agent is added on at least one side of a substrate.   The release paper according to claim 1 or 2, wherein the antistatic agent layer has a thickness of 0.01 to 10 µm.   The release paper according to claim 3, wherein the addition amount of the antistatic agent is added in a ratio of 1 to 25 by weight with respect to the release agent 100. The release paper according to any one of claims 1 to 5, wherein the base material is subjected to a sealing treatment on a laminated surface.

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