JP2013078849A - Release sheet and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release sheet which can be applied to various adhesive materials and prevent a release surface from generating static electricity by demonstrating excellent releasability and antistatic properties and to provide a method for producing the release sheet at a low cost while considering environmental problems and work efficiency.SOLUTION: In the release sheet, a functional layer is formed on a base material. The total amount of a silicone compound and a tin oxide compound contained in the functional layer is at least 80 mass% to the entire amount of the functional layer. The release sheet contains 10-200 pts.mass of the tin oxide compound to 100 pts.mass of the silicone compound.

Description

The present invention relates to a release sheet and a manufacturing method thereof. Specifically, the present invention relates to a release sheet excellent in release properties and antistatic properties and a preferable production method thereof.

  The release sheet is not only a material for protecting the adhesive material, but also film for film forming process when casting polyurethane resin, polyacrylic resin, etc., film for forming green sheet of multilayer ceramic capacitor, etc. It is used in various situations regardless of.

  In particular, the pressure-sensitive adhesive sheet obtained by processing the pressure-sensitive adhesive material into a sheet has a wide variety of uses, and accordingly, a release sheet is also used as the protective material or as a carrier when manufacturing the pressure-sensitive adhesive sheet.

  As described above, the release sheet is used in various scenes, but the following problems are common to the various release sheets. In other words, when a release sheet is peeled from a sheet-like material in which an adhesive material is laminated on the release sheet, static electricity is generated on the release surface of the adhesive material, and foreign matter such as dust, dust, and dust in the atmosphere adheres to the release surface. To do. If it does so, there will be a problem that the adhesive force of the adhesive material is lowered due to this, and as a result, a product using the adhesive material is defective. Therefore, there has been an attempt to impart antistatic properties to the release sheet.

  Specifically, as described in Patent Document 1, a method of forming an antistatic layer in advance on the surface of a film as a substrate, or as disclosed in Patent Document 2, a functional layer (release layer) There is a method of imparting antistatic properties to the release sheet by devising the composition.

JP 2007-1293 A JP 2010-158816 A

  However, in the invention described in Patent Document 1, since it is necessary to form the antistatic layer and the release layer separately, there is a problem in that the manufacturing cost increases as the number of steps increases.

  On the other hand, the invention described in Patent Document 2 can be expected to be effective in reducing the manufacturing cost as compared with the invention described in Patent Document 1 in that a functional layer having antistatic properties can be formed in one step. However, in the present invention, there is a problem that releasability is reduced while realizing antistatic properties, and there is still a room for study to improve both characteristics.

  The present invention eliminates the drawbacks of the prior art as described above, and can be applied to various adhesive materials by exhibiting excellent release properties and antistatic properties. The purpose is to provide a release sheet that is difficult to generate, and at the same time, it is a technical problem to provide a method for manufacturing the release sheet at a low cost while considering the environment and work efficiency. .

As a result of intensive studies to solve the above-mentioned problems, the present inventor can provide a release sheet that is excellent in antistatic property as well as releasability by using a silicone compound and a tin oxide compound in combination. The present inventors have found that this release sheet can be produced at low cost and have reached the present invention.
That is, the gist of the present invention is as follows.

(1) A release sheet in which a functional layer is provided on a base material, wherein the functional layer contains a silicone compound and a tin oxide compound in total of 80% by mass or more based on the entire functional layer, and A release sheet comprising 10 to 200 parts by mass of a tin oxide compound per 100 parts by mass of a silicone compound.
(2) Used for the adhesive material, the peel strength between the functional layer and the adhesive material when applying an adhesive material using an acrylic adhesive is 0.5 N / cm or less The release sheet as described in (1) above, wherein
(3) The release sheet according to (1) or (2) above, wherein the functional layer has a surface resistivity of 10 ¹² Ω / □ or less.
(4) An aqueous dispersion containing 80% by mass or more of a silicone compound and a tin oxide compound in the total solid content, and containing 10 to 200 parts by mass of a tin oxide compound with respect to 100 parts by mass of the silicone compound. A method for producing a release sheet, which comprises applying onto a substrate and drying.
(5) The method for producing a release sheet according to the above (4), wherein the drying temperature is 100 ° C. or higher.

  According to the present invention, a release sheet having excellent release properties and antistatic properties can be provided. In addition, the release sheet of the present invention can be applied to various adhesive materials, in which case the release sheet can be easily peeled off, and after peeling, static electricity hardly occurs on the peeled surface of the adhesive material, and the atmosphere Foreign matter such as dust, dust, and dirt inside is less likely to adhere to the release surface.

  And according to the manufacturing method of this invention, the said release sheet can be manufactured at low cost, considering the environmental aspect and work efficiency.

Hereinafter, the present invention will be described in detail.

  The release sheet of the present invention comprises a functional layer on a substrate, and the functional layer contains a silicone compound and a tin oxide compound.

  As the silicone compound in the present invention, any compound can be used as long as it contributes to improving the release property of the functional layer. Specific types of silicone compounds include addition reaction type, condensation reaction type, ultraviolet ray curable type, electron beam curable type, etc. Among them, it can be widely used for release sheet design such as peel strength and quality adjustment. Therefore, the addition reaction type is preferably used. As the addition reaction type silicone compound, a conventionally known thermosetting addition reaction type silicone resin can be used. For example, polyorganosiloxane having an alkenyl group in the molecule can be used. Specific examples include polydimethylsiloxane having a vinyl group and polydimethylsiloxane having a hexenyl group, and these may be mixed and used as necessary.

  When using the silicone compound, it may be used as it is, that is, in a solvent-free state, but in general, the silicone compound is diluted in an organic solvent such as toluene or emulsified with water. In particular, from the viewpoint of mixing stability with a tin oxide compound, it is preferable to use a silicone compound in an emulsion form (hereinafter referred to as a silicone emulsion). In addition, as a silicone type compound, you may use a commercially available thing, for example, as an emulsion of addition reaction type silicone type compound, "KM-3951", "KM-768", etc. by Shin-Etsu Chemical Co., Ltd. Asahi Kasei Wacker Silicone “430”, “440”, “480”, “400E”, and Arakawa Chemical “902”, “909”, and the like.

  When using a silicone-based compound, if necessary, a catalyst, a crosslinking agent, an addition reaction inhibitor, a release regulator, an adhesion improver, etc. may be used in combination, and a functional layer is formed by irradiating ultraviolet rays later. In this case, a photoinitiator may be used in combination. In the present invention, it is generally preferable to use a catalyst and a crosslinking agent in combination. For example, as one aspect of using a catalyst together, the above-described polyorganosiloxane having an alkenyl group in the molecule and hydrogensiloxane are combined with a platinum catalyst. It is possible to employ a mode in which heat curing is performed using

  On the other hand, as the tin oxide compound in the present invention, for example, tin oxide, antimony-doped tin oxide, tin oxide-doped indium and the like can be used.

  The tin oxide compound is preferably in the form of particles, and the particle diameter is preferably 200 nm or less in terms of the number average particle diameter. When the particle diameter exceeds this range, in addition to the transparency of the functional layer, the stability of an aqueous dispersion (tin oxide aqueous dispersion) containing a tin oxide compound described later tends to be lowered. The number average particle size of the tin oxide compound is measured by a dynamic light scattering method.

  The method for producing the tin oxide compound is not particularly limited. For example, a method of hydrolyzing or thermally hydrolyzing metal tin or a tin compound, a method of alkaline hydrolysis of an acidic solution containing tin ions, or a solution containing tin ions is ionized. An ion exchange method using an exchange membrane or an ion exchange resin can be employed.

  A commercially available tin oxide compound may also be used. For example, as an aqueous dispersion containing a normal tin oxide compound, there is “AS11T” manufactured by Unitika, and as an aqueous dispersion containing an antimony-doped tin oxide compound, “SN-100D” manufactured by Ishihara Sangyo Co., Ltd. There is. In addition, examples of tin oxide-doped indium-based compounds include “ITO” manufactured by CI Kasei Co., Ltd.

  The silicone compound and the tin oxide compound are contained in the functional layer. And content of both compounds needs to be 80 mass% or more in total with respect to the whole functional layer. If the total content is out of this range, the absolute amount of both compounds in the functional layer is remarkably reduced, so that a release sheet that simultaneously exhibits release properties and antistatic properties cannot be obtained.

  Furthermore, as a use ratio of both compounds in the functional layer, it is necessary that 10 to 200 parts by mass of the tin oxide compound is contained with respect to 100 parts by mass of the silicone compound, and similarly 50 to 200 parts by mass is contained. It is more preferable that 70 to 150 parts by mass is contained. When the content of the tin oxide compound is less than 10 parts by mass, the release sheet does not exhibit antistatic properties. On the other hand, when the content exceeds 200 parts by mass, the tin oxide compound increases relatively. In addition to inhibiting the curing reaction of the compound and reducing the adhesion between the functional layer and the base material, the release property of the release sheet is also greatly reduced.

  The functional layer in the present invention contains a predetermined amount of the silicone compound and the tin oxide compound as described above. In the present invention, as long as this requirement is satisfied, any other composition may be contained in the functional layer, but it is preferable to select and use a material that is difficult to reduce the release property and antistatic property of the release sheet. To do. Examples of other compositions include polyester resins, polyolefin resins, acrylic resins, polyurethane resins, polyamide resins, polystyrene resins, polyimide resins, polycarbonate resins, polyarylate resins, and the like. In addition, various additives such as catalysts, crosslinking agents, addition reaction inhibitors, release modifiers, adhesion improvers, pigments, dyes, UV absorbers, leveling agents, antifoaming agents, anti-waxing agents, dispersants, and other compositions It may be used as a product.

  In this respect, in the present invention, it is preferable to form a functional layer from a silicone compound, a tin oxide compound, and various additives. In this case, a catalyst and a crosslinking agent are preferable, and a crosslinking agent is more preferable. Is preferred.

  Although the above can be adopted as the composition constituting the functional layer, on the other hand, the thickness of the functional layer is preferably 0.01 to 5 μm, more preferably 0.05 to 1 μm, and more preferably 0.1 to 0.5 μm. Is more preferable, and 0.1 to 0.3 μm is particularly preferable. When the thickness is less than 0.01 μm, it is difficult to form a uniform functional layer, and it becomes difficult for the release sheet to sufficiently exhibit release properties and antistatic properties. On the other hand, when the thickness exceeds 5 μm, not only the formation of the functional layer tends to be difficult, but also the production cost tends to increase, and the adhesion between the functional layer and the substrate tends to decrease.

  In the present invention, the functional layer is formed on the substrate. Any substrate can be used as long as it is suitable for forming a release sheet. Specifically, a resin material, paper, synthetic paper, cloth, metal material, glass material, or the like is appropriately combined.

  In this case, it is generally preferable to use a thermoplastic resin as the resin material. Specifically, polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polylactic acid (PLA), polyolefin resins such as polypropylene, polystyrene resin, nylon 6, poly-m-xylylene adipamide ( Polyamide resin such as MXD6 nylon), polycarbonate resin, polyacrylonitrile resin, polyimide resin and multilayers of these resins (for example, nylon 6 / MXD6 nylon / nylon 6, nylon 6 / ethylene-vinyl alcohol copolymer / nylon) 6) or a mixture.

  As the paper, Japanese paper, craft paper, liner paper, art paper, coated paper, carton paper, glassine paper, semi-glassine paper, and the like can be used. The paper may be provided with a sealing layer or the like.

  The synthetic paper may have a single layer structure or a multilayer structure, and the structure is not particularly limited. In the case of a multilayer structure, for example, a two-layer structure of a base layer and a surface layer, a three-layer structure in which a surface layer is present on the front and back surfaces of the base layer, and a multilayer in which a resin film layer is present between the base layer and the surface layer Examples include the structure. Each layer in the synthetic paper may contain an inorganic or organic filler. Further, each layer may be a microporous material having a large number of fine voids.

  As the cloth, various synthetic fibers, non-woven fabrics made of natural fibers or recycled fibers, woven and knitted fabrics and the like can be used.

  As the metal material, for example, a metal foil such as an aluminum foil or a copper foil, or a metal plate such as an aluminum plate or a copper plate can be used. As a glass material, a glass plate or a cloth made of glass fiber can be used. Can be used.

  Among the above materials, a resin material is particularly preferable as a material constituting the base material, and among them, a thermoplastic resin film obtained by molding a thermoplastic resin material into a film from the viewpoint of mechanical characteristics and thermal characteristics is preferable. In particular, a PET film is preferable in terms of price.

  The thermoplastic resin film may contain various additives, stabilizers, plasticizers, lubricants, antioxidants, and the like. In addition, the thermoplastic resin film may be subjected to corona treatment, plasma treatment, ozone treatment, chemical treatment, solvent treatment, etc. as a pretreatment from the viewpoint of improving adhesion with the functional layer, Silica, alumina or the like may be deposited on the surface. Furthermore, you may extend | stretch a thermoplastic resin film as needed. And on a film, you may provide a barrier layer, an easily bonding layer, an ultraviolet absorption layer, etc. similarly as needed.

  The functional layer in the present invention contains a tin oxide compound, but the base material may contain an antistatic agent, and another antistatic layer that is not a functional layer may be provided if necessary. Good.

  Although the above can be adopted as the material constituting the substrate, on the other hand, the thickness of the substrate is not particularly limited, but is preferably 1 to 1000 μm and more preferably 1 to 500 μm in terms of practical use. Preferably, 10 to 200 μm is more preferable, and 12 to 150 μm is particularly preferable.

  In the present invention, the functional layer is provided on the substrate as described above. In this case, the functional layer only needs to be provided on at least one of the substrates, and the functional layer may be provided on both surfaces of the substrate as necessary. For example, when functional layers having different releasability are provided on both surfaces of the base material, the adhesive material is applied to the release sheet and wound up in a roll shape, and then blocking caused by the adhesive material is effectively suppressed when the roll is pulled out. You can also. In this respect, if the drawing is smooth, the sticking to the adherend is also smooth, and the release sheet can be smoothly peeled after the sticking.

  The release sheet of the present invention is thus provided with a functional layer on a substrate, and the functional layer contains a predetermined amount of a silicone compound and a tin oxide compound. Thereby, the release sheet of the present invention exhibits excellent release properties and antistatic properties. Here, specifically, as the index of both characteristics, the former employs the peel strength when a specific adhesive material is used, and the latter employs the surface resistivity.

  First, the peel strength between the functional layer and the pressure-sensitive adhesive material when a pressure-sensitive adhesive material using an acrylic pressure-sensitive adhesive is applied is adopted as the releasability index. In the present invention, the peel strength is preferably 0.5 N / cm or less, more preferably 0.4 N / cm or less, still more preferably 0.3 N / cm or less, and particularly preferably 0.2 N / cm or less. If the peel strength exceeds 0.5 N / cm, it tends to lack suitability as a release sheet, which is not preferable. In this index, an acrylic adhesive is used as the adhesive material. This is because acrylic adhesives are most commonly used in the evaluation of releasability.

On the other hand, the surface resistivity of the functional layer is adopted as an index of antistatic properties. In the present invention, the surface resistivity is preferably 10 ¹² Ω / □ or less, more preferably 10 ¹¹ Ω / □, and further preferably 10 ¹⁰ Ω / □ or less. When the surface resistivity exceeds 10 ¹² Ω / □, it becomes difficult for the release sheet to sufficiently exhibit antistatic properties, and as a result, dust, dust, dust, etc. in the atmosphere adhere to the release surface of the adhesive material. Thus, the adhesive strength of the adhesive material is lowered, and as a result, a product using the adhesive material may be defective, which is not preferable.

  Next, a preferred method for producing the release sheet of the present invention will be described.

  In order to obtain the release sheet of the present invention, a liquid material containing a silicone compound and a tin oxide compound is first prepared, and then applied to a previously prepared substrate and dried. By adopting this method, the thickness of the functional layer can be made uniform, and the release sheet can be mass-produced.

  The method for producing such a liquid material is not particularly limited as long as each component is uniformly dispersed in the liquid material. For example, a method of mixing a dispersion containing a silicone compound and a dispersion containing a tin oxide compound, a method of dispersing a silicone compound and a tin oxide compound in the same medium, and the like can be employed. Then, the former method is preferable. An emulsifier may be used for dispersion. However, since the emulsifier may remain in the functional layer later and reduce the performance of the layer, it is preferable to suppress the use amount as much as possible or not. In addition, in the liquid material, the silicone compound and the tin oxide compound are contained in a total solid content of 80% by mass or more, and the latter is contained in an amount of 10 to 200 parts by mass with respect to the former 100 parts by mass. It is as follows.

  The medium constituting the liquid is not particularly limited as long as each component can be stably dispersed, but water or an organic solvent is generally used. Among these, water or an aqueous medium mainly containing water and an appropriate amount of a hydrophilic organic solvent added thereto is preferable from the viewpoints of the environment and work efficiency.

  Here, as the hydrophilic organic solvent, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, etc. Alcohols, tetrahydrofuran, ethers such as 1,4-dioxane, ketones such as acetone and methyl ethyl ketone, methyl acetate, acetic acid-n-pro Le, isopropyl acetate, -tert- butyl, methyl propionate, ethyl propionate, esters such as dimethyl carbonate, dimethylformamide, dimethylacetamide, diacetone alcohol, and acetonitrile can be used.

  Furthermore, the use of a hydrophilic organic solvent is also effective in improving the wettability of the liquid material, and is also effective in suppressing repelling during coating.

  The solid content concentration in the liquid material may be appropriately determined in consideration of the application conditions, the thickness of the functional layer, the performance, etc., and is not particularly limited. From the viewpoint of forming a functional layer having excellent performance, 1 to 50% by mass is preferable, and 3 to 20% by mass is more preferable.

  The liquid material may contain an optional auxiliary agent as necessary. For example, a crosslinking agent, leveling agent, antifoaming agent, anti-waxing agent, pigment dispersant, ultraviolet absorber, etc., titanium oxide In addition, pigments such as zinc white and carbon black, dyes and the like may be included.

  Although any method can be adopted as a method for applying such a liquid material to the substrate, a method capable of forming a uniform layer on the substrate is usually employed. Specifically, gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, brush coating, etc. are employed. In addition, after application | coating, you may set this near room temperature as needed.

  After apply | coating a liquid substance on a base material, this is dried. Thereby, a functional layer having a uniform thickness can be formed in close contact with the substrate. As a drying method, it is possible to adopt a method such as natural drying, heat treatment using a tenter, or charging in a thermostatic bath for a predetermined time.

  The drying temperature is preferably a high temperature from the viewpoint of accelerating the curing of the silicone compound, specifically 100 ° C. or higher. However, if the temperature is too high, the substrate may be damaged by heat, and therefore, generally, 120 ° C to 170 ° C is preferable, and 140 to 150 ° C is more preferable. When the drying temperature is less than 100 ° C., the curing of the silicone compound is difficult to proceed, and as a result, the adhesion between the base material and the functional layer is decreased, and at the same time, the releasability as a release sheet tends to be decreased. Absent.

  Similarly, the drying time is preferably 15 seconds or more, and more preferably 30 seconds or more, from the viewpoint of promoting the curing of the silicone compound. When the drying temperature is less than 15 seconds, the silicone compound is difficult to cure as described above, which is not preferable.

  After drying, the release sheet may be heat-treated as necessary.

  Since the release sheet of the present invention is excellent in releasability, it can be applied to various adhesive materials.

  Examples of the pressure-sensitive adhesive material include a pressure-sensitive adhesive sheet, an adhesive sheet, a pressure-sensitive adhesive tape, and a pressure-sensitive adhesive tape, and a material in which a pressure-sensitive adhesive is laminated on a base material or a material in which a pressure-sensitive adhesive itself is formed into a sheet shape. The kind of base material in the adhesive material and the composition of the adhesive are not particularly limited. In this respect, the above-mentioned paper, cloth, resin material, etc. are generally preferred as the base material, and as the pressure-sensitive adhesive, acrylic pressure-sensitive adhesives, natural rubber-based pressure-sensitive adhesives, synthetic rubber-based pressure-sensitive adhesives are generally preferable, and acrylic pressure-sensitive adhesives. Agents are particularly preferred.

  Further, the pressure-sensitive adhesive may contain a rosin-based, coumarone-indene-based, terpene-based, petroleum-based, styrene-based, phenol-based, or xylene-based tackifier as necessary.

  The method for applying the release sheet to the pressure-sensitive adhesive material is not particularly limited. Specifically, the liquid release material in which the pressure-sensitive adhesive is dissolved is applied onto the release sheet and dried. Examples thereof include a method of laminating an adhesive material on a sheet, and a method of bonding an adhesive material provided with an adhesive on a substrate and a release sheet. Furthermore, it is also possible to use two types of release sheets with adjusted peel strengths in such a manner that they are bonded to both surfaces of the adhesive material and the adhesive material is sandwiched between them. In addition, when the release sheet is bonded to both surfaces of the adhesive material, for example, one release sheet may be peeled off at the time of use and bonded to the adherend, and then the other release sheet may be peeled off.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

(1) Thickness of functional layer The thickness of the entire release sheet was measured with a contact-type film thickness meter, and the thickness was determined by subtracting the thickness of the substrate from the measured value.
(2) Peel strength On the functional layer side of the release sheet, a 50 mm wide and 150 mm long polyester adhesive tape (manufactured by Nitto Denko Corporation, “No. 31B (trade name)”, using acrylic adhesive) ”with a rubber roll After that, the sample was stored in a room at 23 ° C. for a day to obtain a sample for measuring peel strength. Then, in a thermostatic chamber at 25 ° C., using a tensile tester (manufactured by Intesco, precision universal material tester, “2020 type (trade name)”), the adhesive tape and the release sheet in the peel strength measurement sample The peel strength was measured. The conditions were a peeling angle of 180 ° C. and a peeling speed of 300 mm / min.
(3) Surface resistivity Based on JIS K6911, using a digital ultra-high resistance / microammeter (manufactured by Advantest Co., Ltd., “R8340 (trade name)”), a release sheet at a temperature of 23 ° C. and a humidity of 65%. The surface resistivity of the functional layer was measured.

Example 1
Silicone emulsion (manufactured by Shin-Etsu Chemical Co., Ltd., “KM-3951 (trade name)”, solid content concentration 40% by mass) and tin oxide ultrafine particle aqueous dispersion (manufactured by Unitika Ltd., “AS11T (trade name)”, solid content concentration 11.5 mass% and a number average particle diameter of 9.8 nm) were prepared, and both were mixed so that 100 mass parts of tin oxide ultrafine particles were contained with respect to 100 mass parts of the silicone compound. And water and isopropanol were added in the ratio of 4: 1, the whole solid content concentration was adjusted to 10 mass%, and it fully stirred. Thereafter, 2.5 parts by mass of a platinum-based catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., “CAT-PM-10A (trade name)”) is added to 100 parts by mass of the silicone compound, and the silicone compound and the tin oxide compound are added. And an aqueous dispersion containing a platinum-based catalyst.

  Next, the aqueous dispersion was applied to the corona-treated surface of a biaxially stretched PET film (manufactured by Unitika Ltd., “Emblet S-50 (trade name)”, thickness 50 μm) using a Mayer bar. The film was dried at 0 ° C. for 30 seconds to form a 0.1 μm functional layer on the film to obtain a release sheet.

(Examples 2 and 3, Comparative Examples 3 and 4)
50 parts by mass (Example 2), 200 parts by mass (Example 3), 5 parts by mass (Comparative Example 3), 300 parts by mass (Comparative Example 4) of ultrafine tin oxide particles with respect to 100 parts by mass of the silicone compound ) Except for mixing both dispersions so as to be contained, the same procedure as in Example 1 was performed to obtain two types of release sheets (Examples 2 and 3) and two types of laminated sheets (Comparative Examples 3 and 4). It was.

Example 4
Instead of “KM-3951 (trade name)”, a silicone emulsion (“480 (trade name)” manufactured by Asahi Kasei Wacker Silicone Co., Ltd.) is used. A release sheet was obtained in the same manner as in Example 1 except that a catalyst (“V72 (trade name)” manufactured by Asahi Kasei Wacker Silicone Co., Ltd.) was used.

(Examples 5 and 6)
Example 4 except that both dispersions were mixed such that 50 parts by mass (Example 5) and 200 parts by mass (Example 6) of tin oxide ultrafine particles were added to 100 parts by mass of the silicone compound, respectively. In the same manner, two types of release sheets were obtained.

(Example 7)
Instead of “AS11T (trade name)”, antimony-doped tin oxide ultrafine particle dispersion (manufactured by Ishihara Sangyo Co., Ltd., “SN-100D (trade name)”, solid content concentration 30.0 mass%, number average particle diameter 60 nm) Except having used, it carried out similarly to Example 1 and obtained the release sheet.

(Example 8)
A release sheet was obtained in the same manner as in Example 7 except that 10 parts by mass of tin oxide ultrafine particles were mixed with 100 parts by mass of the silicone compound.

(Comparative Example 1)
Water and isopropanol were added to “KM-3951 (trade name)” at a ratio of 4: 1 to adjust the total solid content concentration to 10% by mass and sufficiently stirred. Thereafter, 2.5 parts by mass of “CAT-PM-10A (trade name)” was added to 100 parts by mass of the silicone compound to obtain an aqueous dispersion containing the silicone compound and a platinum catalyst.

  Thereafter, using the obtained aqueous dispersion, the same substrate as in Example 1 was coated and dried under the same conditions to obtain a laminated sheet.

(Comparative Example 2)
Isopropanol was added to “AS11T (trade name)” to adjust the total solid content concentration to 10% by mass, and the mixture was sufficiently stirred. Thereafter, using the obtained aqueous dispersion, the same substrate as in Example 1 was coated and dried under the same conditions to obtain a laminated sheet.

  Table 1 shows the evaluation results of the release sheets obtained in the above examples and the laminated sheets obtained in the comparative examples.

  The release sheets obtained in Examples 1 to 8 were excellent in release properties and antistatic properties.

In contrast, each of the laminated sheets according to Comparative Example 1 in which no tin oxide compound is used and Comparative Example 3 in which the content of the same compound is small are both excellent in releasability but inferior in antistatic properties. Met. On the other hand, the laminated sheets according to Comparative Example 2 in which no silicone compound is used and Comparative Example 4 in which the content of the compound is relatively small are both excellent in antistatic properties but poor in releasability. Met.

Claims (5)

  A release sheet provided with a functional layer on a substrate, wherein the functional layer contains a silicone compound and a tin oxide compound in a total amount of 80% by mass or more based on the entire functional layer, and further a silicone compound A release sheet containing 10 to 200 parts by mass of a tin oxide compound per 100 parts by mass.   The peel strength between the functional layer and the pressure-sensitive adhesive material is 0.5 N / cm or less when applied to the pressure-sensitive adhesive material and using a pressure-sensitive adhesive material using an acrylic pressure-sensitive adhesive. The release sheet according to claim 1. The release sheet according to claim 1, wherein the functional layer has a surface resistivity of 10 ¹² Ω / □ or less.   An aqueous dispersion containing a silicone compound and a tin oxide compound in a total solid content of 80% by mass or more and containing 10 to 200 parts by mass of a tin oxide compound with respect to 100 parts by mass of the silicone compound on the substrate. A method for producing a release sheet, which is applied to a substrate and dried. The method for producing a release sheet according to claim 4, wherein the drying temperature is 100 ° C or higher.