JP2015110315A - Release sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release sheet having an under coating agent layer which prevents a silicone curing inhibitor material included in a base material or a layer coated on the base material from moving to a silicone release layer, provides excellent adhesion between the base material or the silicone curing inhibitor containing coated layer and the silicone release layer, and is excellent in resistance against a release agent diluting solvent, such as toluene and hexane.SOLUTION: In a release sheet, an under coating agent layer including animal wax and a release layer consisting of at least one kind of cured layers selected from an additional reaction type thermosetting silicone, ultraviolet curable silicone and electron beam curable silicone on the under coating agent layer surface, are sequentially laminated on one surface of a film base including the curable inhibitor material of a silicone release agent.

Description

  The present invention provides an intermediate between the coated surface of a film containing a silicone release agent curing inhibitor or a film coated with a layer containing the silicone release inhibitor and a silicone release layer. The present invention relates to a release sheet comprising an undercoat layer having excellent adhesion to both the material and the silicone release layer.

  In general, a release sheet is produced by forming a release layer made of a silicone release agent having a releasability from an adhesive substance such as polyorganosiloxane on a base sheet, and is used for various applications such as seals and labels. ing. Conventionally, paper such as polyethylene laminated paper and glassine paper has been used as the base material for the release sheet, but in recent years, plastic films made from polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polyvinyl alcohol, etc. Is being widely used. The demand for plastic films is increasing year by year because they are superior to paper in terms of mechanical strength, transparency, dimensional stability, smoothness, cost, and the like.

  Moreover, the silicone release agent is generally known as a thermosetting type, an ultraviolet curable type, an electron beam curable type, or the like depending on the curing means. Thermosetting silicone release agents have the advantage of being easy to handle because curing proceeds at a relatively low temperature (around 100 ° C.), and are currently most widely used.

  The thermosetting silicone release agent can be classified according to its curing mechanism, and there are mainly two types, a condensation reaction type and an addition reaction type. Among them, addition reaction type thermosetting silicone (hereinafter referred to as “addition reaction type silicone”) has a shorter reaction time than the condensation reaction type thermosetting silicone, and is suitable for the pressure sensitive adhesive surface in contact with the release agent surface. While there are many advantages such as a small amount of migration and the ability to easily control the peeling resistance against the adhesive substance from heavy peeling to light peeling, there are drawbacks in that the type of substrate used is limited.

  In general, an addition reaction type silicone is prepared by heating a polydimethylorganosiloxane containing a vinyl group bonded to a silicon atom in a molecule and a polydimethylorganosiloxane having a hydrogen bonded to a silicon atom in the molecule using a platinum catalyst. Obtained by curing. However, the platinum catalyst used here is a substance that inhibits the curing of addition reaction type silicone (hereinafter referred to as “silicone curing inhibition”) such as sulfur, organic sulfur compound, organic tin compound, amine compound, organic phosphorus compound, and organic peroxide. Touching “substance”) loses its catalytic action and causes a curing inhibition phenomenon that the curing reaction does not proceed sufficiently.

  When thermosetting silicone is coated on heat-sensitive substrates such as films and polyethylene laminated paper, shrinkage, wrinkles, foaming, curling, etc. are likely to occur due to the effects of heat during curing. There is a problem that the gloss of the coated surface tends to decrease.

  On the other hand, ultraviolet curable silicone is basically a method that cures by the energy of ultraviolet rays having a wavelength of 200 to 400 nm, and therefore has higher energy efficiency than thermosetting silicone, and imparts energy to the substrate. Since the rate is small, it is possible to apply a silicone film to a plastic film having low heat resistance, or to form a high gloss silicone surface found in high-grade labels.

The ultraviolet curing method has a compact device, is relatively inexpensive, and is excellent in productivity with respect to the size of the device, and in recent years, its use ratio in release paper silicone has increased.
The position of the ultraviolet curable type in the silicone for release paper is contrasted with the ease of its use for small quantities and many types of special uses, and the electron beam curing method is suitable for mass production of specific types.
The following four types of curing mechanisms for ultraviolet curable silicone have been proposed.

<Acrylic silicone>
A photopolymerization initiator is added to silicone having —R—OCOCH═CH ₂ group, and many compounds are applicable depending on the type of R.
The photopolymerization initiator may be the same as that used for a general ultraviolet curable resin, has the same curing characteristics, and curing is inhibited by oxygen when the film is a thin film of 1 μm or less. Acrylic groups are highly polar and tend to have high surface tension, and this type of silicone generally has a heavy peel force.

<Mercapto-vinyl addition polymerization type>
A photopolymerization initiator is added to a siloxane having a mercapto group and an unsaturated double bond to cause a crosslinking reaction.
This type of silicone can be applied in several combinations depending on the types of Si and SH bonding groups and Si and vinyl bonding groups. Moreover, although it is comparatively hard to receive oxygen inhibition, it has a heavy peeling force and does not easily migrate. In addition, since this type contains a mercapto group, there is also an odor problem.

<Addition reaction type>
The same platinum-based catalyst as the addition reaction type of thermosetting silicone is used, and the reaction mechanism is the same as that of the thermosetting type. The curability is slightly inferior to that of mercapto-vinyl addition polymerization, but there is no oxygen inhibition, and even a thin film having a thickness of 0.1 μm or less is cured, and a non-migration and light peeling force can be obtained.

<Cationic polymerization type>
An onium salt catalyst is added to a siloxane having an epoxy group, which is a type in which an epoxy group is polymerized by being decomposed by ultraviolet rays to produce a Lewis acid.
This mold has good curability, no oxygen inhibition, and a light peeling force.

  The form of the ultraviolet curable silicone is usually a solventless type, but there is also a solvent type in order to apply a thin film of 0.5 μm or less to a film. In this case, it is applied in the same way as solvent-type silicone, and after drying the solvent with a low-temperature dryer, it is irradiated with ultraviolet rays, but this mold has good adhesion to the film, and a release sheet using a film substrate. Suitable for manufacturing.

In recent years, a compact and self-shielding electro curtain type electron beam irradiation apparatus has been developed, and its application to release paper is also being studied. Electron beams have a higher energy density than heat and ultraviolet rays, and when applied to release paper, they improve productivity by high-speed curing, coating on plastic films with low heat resistance by low-temperature curing, or high-gloss luxury labels. Production etc. are expected.
Silicone having a radical polymerizable group is suitable for electron beam curing, but even silicone having no functional group can be cured by increasing the irradiation amount. Most of the electron beam curable silicones currently in practical use are acrylic group-containing silicones.

  On the other hand, polyolefin films and polyolefin synthetic paper contain trace amounts of organophosphorus compound-based antioxidants and amine compound-based antistatic agents, which bleed to the surface and migrate to the silicone release layer as a silicone curing inhibitor. As a result, problems such as insufficient curing of the silicone release layer and reduced adhesion between the substrate and the silicone release layer may occur. Further, when a silicone release layer is provided on a sheet coated with a layer containing a silicone curing inhibitor such as an antistatic agent, the silicone release layer is also inhibited from being cured.

  As a means for overcoming such drawbacks, a polyester film having a low content of a silicone curing inhibiting component is used as a base material, an excessive amount of platinum catalyst more than usual is added, or the base material or the antistatic agent layer For the purpose of preventing the migration of silicone curing inhibitors contained in etc. to the silicone release layer, a method such as providing an undercoat layer made of acrylic resin, polyester resin, etc. on the substrate or coating layer has been proposed. (Patent Document 1).

  However, the polyester film is more expensive than the polyolefin film, and the use of an excess platinum catalyst more than that usually used is disadvantageous in terms of economy and workability. In the method of providing the primer layer, the adhesion between the primer layer and the substrate may be insufficient. Further, when the silicone release agent is diluted with a solvent, the primer layer itself is caused by the solvent. Neither method was fully satisfactory because of the potential for erosion.

  Also, an undercoat layer containing an α-olefin-unsaturated carboxylic acid copolymer and a release layer composed of an addition reaction type thermosetting silicone cured layer are sequentially laminated on one side of the film base material. Although the release sheet was disclosed, it was insufficient in terms of the adhesiveness of the silicone release agent.

Japanese Patent Laid-Open No. 11-969 JP 2007-1117 A

  In order to meet the above-mentioned demand, the present invention can prevent the transition of the silicone curing inhibitor contained in the base material and the layer coated on the base material to the silicone release layer, and contains the base material and the silicone curing inhibitor. It is an object of the present invention to provide a release sheet having an undercoat layer made of animal wax that is excellent also in adhesion between the coating layer and the silicone release layer and resistance to a release agent dilution solvent such as toluene and hexane.

  As a result of intensive studies to achieve the above object, the inventors of the present invention applied at least one surface of a film containing a silicone curing inhibitor to the coated surface of a film coated with a layer containing the silicone curing inhibitor. An undercoat layer made of a specific animal wax is provided, and at least one selected from an addition reaction type thermosetting silicone release agent, an ultraviolet curable silicone release agent, and an electron beam curable release agent on the surface of the undercoat layer. It has been found that a release sheet that solves the above problems can be obtained by providing a seed release layer, and the present invention described below has been completed.

(1) An undercoat layer containing animal wax on one surface of a film substrate containing a curing inhibitor for a silicone release agent, and an addition reaction type thermosetting silicone, an ultraviolet curable silicone on the surface of the undercoat layer, A release sheet in which release layers comprising at least one cured layer selected from electron beam curable silicones are sequentially laminated.

(2) A primer layer containing animal wax on the surface of the coating layer of the film base material on which a layer containing a curing inhibitor of the silicone release agent is coated, and an addition reaction type on the surface of the primer layer A release sheet in which release layers comprising at least one type of cured layer selected from thermosetting silicone, ultraviolet curable silicone, and electron beam curable silicone are sequentially laminated.

(3) The release sheet according to (1) or (2), wherein the animal wax contained in the undercoat layer is at least one selected from insect wax, whale wax, and wool wax.

(4) The release sheet according to any one of (1) to (3), wherein the animal wax contained in the undercoat layer is shellac.

(5) The release sheet according to any one of (1) to (4), wherein the coating amount of the undercoat layer is 0.1 to 10.0 g / m ² in terms of dry mass.

(6) The release sheet according to any one of (1) to (5), wherein the coating amount of the release agent layer is 0.05 to 3 g / m ² in terms of dry mass.

(7) The film substrate according to any one of items (1) to (6), wherein the film substrate is one selected from a polyolefin film, a polypropylene synthetic paper, a polyester film, and a polyvinyl alcohol film. Release sheet.

(8) The curing inhibitor is at least one selected from sulfur, organic sulfur compounds, organic tin compounds, amine compounds, organic phosphorus compounds, organic peroxides, glycerol, glycols, and tetrahydrofurfuryl derivatives (1 The release sheet according to any one of (7) to (7).

(9) The release sheet according to any one of (1) to (8), wherein the curing inhibitor is a plasticizer or an antistatic agent.

  According to the present invention, the curing inhibition phenomenon of the silicone release agent that occurs when the curing inhibitor of the silicone release agent contained in the substrate or the layer coated on the substrate moves to the release layer, and the substrate and silicone There is provided a release sheet that is compatible with a wide variety of pressure-sensitive adhesives without problems such as a decrease in adhesion with the release agent.

  As the base material containing the curing inhibitor for the silicone release agent used in the release sheet of the present invention, various known materials are used without particular limitation, and examples thereof include polyolefin films and synthetic paper. Specific examples of the substrate include a polyethylene film, a polypropylene film, a polyvinyl chloride film, a polyvinyl alcohol film, etc., and such plastic molded products are various molded products and sheets molded by an injection molding machine depending on the application. Or a film formed into a film shape can be used.

  Examples of the curing inhibitor for the silicone release agent contained in the substrate include an antistatic agent and a plasticizer. Specifically, sulfur, an organic sulfur compound, an organic tin compound, an amine compound, an organic phosphorus Glycerin, ethylene glycol, trimethylene described in pages 371 to 377 of compounds, organic peroxides, “Plasticizers -Theory and Applications-” (Yuki Shobo Co., Ltd., first published on March 1, 1973) Examples include glycols such as glycol, tetramethylene glycol, pentamethylene glycol, propylene glycol, 2,3-butanediol, 1,3-butanediol, diethylene glycol, and triethylene glycol, and tetrahydrofurfuryl derivatives.

  Moreover, you may use what gave surface treatments, such as a corona discharge process, a flame process, a plasma process, an easily bonding coating process, as said base material. As synthetic paper, for example, a thermoplastic polyolefin resin such as polypropylene resin is used as a main raw material, and a composition containing an inorganic or organic filler and a small amount of additives is melted, kneaded, and then slot die of an extruder. Examples thereof include synthetic paper having a film-like or tape-like multi-layer structure produced by an internal paper-making method, which is produced by extruding a film and then biaxially stretching.

  Various known materials can be used without particular limitation as the substrate for coating the layer containing the curing inhibitor of the silicone release agent, and examples include polyester films such as polyethylene terephthalate in addition to the substrate. Such plastic moldings can be used in various forms molded by an injection molding machine depending on the application, or in the form of a sheet or film, and these can be corona discharge treatment, flame treatment, You may use what gave surface treatments, such as a plasma process and an easily-adhesive coating process.

  Examples of the layer containing a curing inhibitor for a silicone release agent applied to the substrate include, for example, a layer containing a mixture of a curing inhibitor for a silicone release agent such as a silane coupling agent and an antistatic agent, and the like. Examples thereof include a layer containing an antistatic agent alone.

  Examples of the antistatic agent serving as a curing inhibitor for the silicone release agent include nonionic surfactants such as alkylethylenediamine. The silane coupling agent has an alkoxy group, an acetoxy group, a halogen and an amino group, a methacryl group, a vinyl group, an epoxy group, and a mercapto group in one molecule, SH6020 manufactured by Toray Dow Corning, SH6023, SZ6030, SZ6032, SZ6300, SH6040, and KBC1003, KBE1003, KBM1003, KBM503, KBN402, KBM603, KBE903 and the like manufactured by Shin-Etsu Chemical Co., Ltd. are listed.

  In the present invention, it is necessary to form a primer layer containing animal wax on the substrate surface. Here, the wax is an ester of a long-chain fatty acid and a long-chain alcohol, and examples thereof include animal waxes, plant waxes, petroleum waxes, mineral waxes, and synthetic waxes. In the present invention, it is necessary to use animal waxes among the waxes from the viewpoint of suppressing the curing inhibition phenomenon of the silicone release agent and the decrease in adhesion between the substrate and the silicone release agent.

  Examples of animal waxes include insect waxes (honey wax, etc.), whale waxes, wool waxes, etc., but they have the effect of inhibiting the curing of the silicone release agent and the phenomenon of lowering the adhesion between the substrate and the silicone release agent layer. Insect wax is preferable from the viewpoint of suppression, and shellac is particularly preferable among the insect waxes.

  The shellac used in the present invention is a product obtained by purifying a resinous substance secreted by a shellworm of about 0.6 to 0.7 mm in length. Insects in Thailand and Thailand are the two major producers, and other species are distributed in China, Indonesia, Myanmar, Vietnam and other countries. The breeding of rackworms is done by sticking twigs with rackworms to blister and mulberry plants, and after the sucker sucks the sap, a resinous material is produced, which is solidified by air. A resin layer is formed on the branches. This is pulverized, washed with water and purified.

  Examples of the purification method include a thermal melting method, a soda method, and a solvent extraction method. The heat melting method is a method in which a resin on a branch is pulverized and washed with water, then the resin is put into a cotton bag, and the product squeezed out of the bag is thinly stretched. The soda method is a method of dissolving a pulverized and washed resin in soda ash or caustic soda solution, removing impurities from the solution, and then depositing with a dilute acid solution, washing with water and drying. The solvent extraction method is a method in which a pulverized and washed resin is dissolved in an alcohol solvent and filtered, and then the solvent is recovered and purified.

  The components of the shellac used in the present invention are slightly different depending on the purification method, but usually, alleuritic acid, jarlaric acid, laxialaric acid is used as the basic resin acid component, and the carboxyl group of this resin acid and other resin acids This is mainly composed of an ester bond of a hydroxyl group. In addition, mixed waxes such as cereal alcohol, ceryl alcohol, and laxeryl alcohol and mixed esters of lignocellic acid, laccelic acid, stearic acid, palmitic acid, etc. are mixed as a wax component, and lacaic acid, erythrolacsin, desoxyerythrolaclac Shin etc. are included. As a method for purifying the resin used in the present invention, a solvent extraction method is preferable in terms of purity and quality.

  This resin is tasteless, odorless, nontoxic, and has no adverse effects on the environment. In addition, as long as there is no hindrance in performance, various assistants such as a wetting agent, a preservative, and an antifoaming agent can be blended in the shellac coating solution. Further, pigments such as kaolin, calcium carbonate, and titanium oxide can be used as appropriate as long as they do not hinder the performance.

As a method for applying the primer, it can be applied by a normal coating machine such as a bar coater, roll coater, multi-stage roll coater, offset gravure coater, direct gravure coater, slot die coater, curtain coater and the like. The coating amount of the primer, 0.1~10.0g / ^{m 2} in dry weight, preferably, suitably 0.2~5.0g / ^{m 2.} Incidentally, when the coating amount is less than 0.1 g / m ² , the effect as the undercoat layer is poor, and when it exceeds 10.0 g / m ² , it is not necessary from the viewpoint of economy.

Examples of the release agent applied to the surface of the undercoat layer of the release sheet of the present invention include an addition reaction type thermosetting silicone release agent, an ultraviolet curable silicone release agent (radical polymerization type silicone release agent, cationic polymerization type silicone release agent, At least one selected from mercapto-vinyl addition polymerization type silicone release agents, addition reaction type silicone release agents) and electron beam curable silicone release agents (radical polymerization type silicone release agents, acrylic silicone release agents) can be used.
From the viewpoint of reducing capital investment, an ultraviolet curable silicone release agent is preferably used.

  For the release agent, if necessary, other ultraviolet curable resin, electron beam curable resin, photopolymerization initiator, crosslinking agent, dye, pigment, wetting agent, antifoaming agent, dispersant, antistatic agent, leveling agent, Various auxiliary agents such as a lubricant may be blended.

As a coating method of the release agent, it can be applied by a normal coating machine, for example, a bar coater, a multi-stage roll coater, an air knife coater, a direct gravure coater, an offset gravure coater or the like.
The coating amount of the release agent, 0.05 to 3 g / ^{m 2} in dry weight, preferably, suitably 0.2 to 1.5 g / ^{m 2.} Incidentally, the coating amount poor effect as a release layer is less than 0.05 g / m ^2, also exceed 3 g / m ² has poor necessity from the viewpoint of economy.
Examples of the device for curing the release agent include a hot air dryer, a far infrared dryer, and an ultraviolet irradiation device (for example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, an electrodeless lamp, etc. There is also an ozone-less type with less ozone, and any type may be used.
As an ultraviolet irradiation device, generally, a plurality of lamps having an output of 30 W / cm or more are often used in parallel. Examples of the electron beam irradiation device include a scanning method, an area beam method, and a self-shielding type.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated more concretely, of course, this invention is not restrict | limited by these Examples. Unless otherwise indicated, parts and% in Examples and Comparative Examples represent parts by mass and mass%, respectively, and the coating amount, the number of parts, the mixing ratio, and the like are all represented by solid content.

<Example 1>
"Formation of primer layer"
A polypropylene film (containing 0.1 part of alkyldiethanolamine as an antistatic agent and having a thickness of 30 μm) was used as a substrate. One side of the base material is subjected to corona treatment, and as a primer for the corona-treated surface of the base material (wetting index by a method according to JIS-K6768-1977: 42 dyn / cm), shellac (trade name: shellac BN-W25A, Gifu) After coating 1.0 g / m ² by bar coating, a primer layer was formed by drying in an oven at 120 ° C. for 1 minute. .

"Manufacture of release sheet"
Subsequently, an addition reaction type thermosetting silicone release agent (trade name: KS847, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to the surface of the undercoat layer by 0.2 g / m ² by bar coating, and then 140 A release agent layer was formed by curing in an oven at 30 ° C. for 30 seconds to obtain a release sheet.

<Example 2>
"Formation of primer layer"
As a base material, a polyvinyl alcohol film (manufactured by Nippon Gosei Co., Ltd., trade name: “Hi-Selon C-800”, thickness 33 μm) was used. As a primer for the glossy surface of the base material, 1.0 g of shellac (trade name: FSP No. 232 (concentration 32%), manufactured by Koyo Chemical Co., Ltd., diluted to 2.5% concentration with isopropyl alcohol) by bar coating After coating / m ^{2, the} primer layer was formed by drying in an oven at 120 ° C. for 1 minute.

"Manufacture of release sheet"
Subsequently, an addition reaction type thermosetting silicone release agent (trade name: KS847T, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the surface of the undercoat layer by bar coating at 0.3 g / m ² , and then 140 A release agent layer was formed by curing in an oven at 30 ° C. for 30 seconds to obtain a release sheet.

<Example 3>
"Formation of primer layer"
As the base material, a polypropylene synthetic paper (trade name: “YUPO SGS80”, manufactured by YUPO CORPORATION, thickness: 80 μm) having a multilayer structure and stretched was used. Corona treatment is applied to the glossy surface, and purified lanolin (manufactured by Yoshikawa Oil Co., Ltd., acid value: 0.3) is used as a primer on the corona-treated surface of the base material (wetting index: 42 dyn / cm according to a method according to JIS K 6768: 1977). Saponification number: 93, hydroxyl value: 36, melting point: 42 ° C., diluted with normal heptane to a concentration of 2.5%) was applied by 7.5 g / m ² by bar coating, and then in an oven at 120 ° C. An undercoat layer was formed by drying for 1 minute.

"Manufacture of release sheet"
Subsequently, an addition reaction type thermosetting silicone release agent (trade name: KS847T, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the surface of the undercoat layer by bar coating at 0.3 g / m ² , and then 140 A release agent layer was formed by curing in an oven at 30 ° C. for 30 seconds to obtain a release sheet.

<Example 4>
"Formation of primer layer"
As the substrate, a polyethylene terephthalate film (trade name: “E5000”, manufactured by Toyobo Co., Ltd., thickness: 50 μm) was used. After applying 1.2 g / m ² of a toluene solution of a mixture of γ-glycidoxypropyltrimethoxysilane (90 parts) and alkyldiethanolamine (10 parts) as an antistatic agent layer on one side of the substrate by bar coating, It dried for 1 minute in 120 degreeC oven.
Using the same shellac as in Example 1 as the undercoat on the surface of the coating layer, after applying 3.0 g / m ² by bar coating, the primer layer is formed by drying in an oven at 120 ° C. for 2 minutes. did.

"Manufacture of release sheet"
Subsequently, an addition reaction type thermosetting silicone release agent (trade name: KS847T, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the surface of the undercoat layer by bar coating at 0.3 g / m ² , and then 140 A release agent layer was formed by curing in an oven at 30 ° C. for 30 seconds to obtain a release sheet.

<Example 5>
"Formation of primer layer"
100 parts of polyvinyl alcohol having a degree of saponification of 99.95 mol% and a polymerization degree of 2400 are impregnated with 10 parts of glycerin (plasticizer) and 170 parts of water, melted and defoamed, and then melted from a T-die onto a metal roll. Extruded to form a film. Thereafter, both the steps of contacting the film obtained by drying and heat treatment with hot air having a temperature of 60 ° C. and a humidity of 80% RH, and subsequently contacting the film with hot air having a temperature of 55 ° C. and a humidity of 40% RH are performed. The total time required was passed for 9 seconds to adjust the humidity, and a polyvinyl alcohol film having a thickness of 40 μm and a moisture content of 4.2% was obtained.
As a primer for the surface of the polyvinyl alcohol film, shellac (trade name: FSP No. 232 (concentration 32%), manufactured by Koyo Chemical Co., Ltd., diluted to isopropyl alcohol to a concentration of 2.5%) was applied by bar coating. After applying 0 g / m ^{2, the} primer layer was formed by drying in an oven at 120 ° C. for 1 minute.

"Manufacture of release sheet"
Subsequently, an addition reaction type thermosetting silicone release agent (trade name: KS847, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to the surface of the undercoat layer by 0.2 g / m ² by bar coating, and then 140 A release agent layer was formed by curing in an oven at 30 ° C. for 30 seconds to obtain a release sheet.

<Example 6>
"Formation of primer layer"
240 g of white whale wax is melted by heating at 55 ° C., 10 g of sucrose fatty acid ester and 10 kg of hot water at 55 ° C. are added and mixed well, and then stirred for 10 minutes with a TK homomixer (manufactured by Tokyo Special Machinery Corporation). And then emulsified into an oil-in-water type to obtain a primer coating solution (concentration 2.4%).
Next, the above primer (whale wax) coating solution was applied to the surface of the same polypropylene film as in Example 1 (containing 0.1 part by weight of alkyldiethanolamine as an antistatic agent, 30 μm thick) by bar coating with 1.0 g / m. ^{After two} coatings, an undercoat layer was formed by drying in an oven at 120 ° C. for 1 minute.

"Manufacture of release sheet"
Subsequently, an addition reaction type thermosetting silicone release agent (trade name: KS847, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to the surface of the undercoat layer by 0.2 g / m ² by bar coating, and then 140 A release agent layer was formed by curing in an oven at 30 ° C. for 30 seconds to obtain a release sheet.

<Example 7>
"Formation of primer layer"
Beeswax (trade name: “deodorized and refined beeswax high acid”, manufactured by Celalica Noda, Inc., isopropyl alcohol on the same polypropylene film as in Example 1 (containing 0.1 part of alkyldiethanolamine as an antistatic agent, 30 μm in thickness) After being coated with 2.0 g / m ² by bar coating, the primer layer was formed by drying in an oven at 120 ° C. for 1 minute.

"Manufacture of release sheet"
Subsequently, an addition reaction type thermosetting silicone release agent (trade name: KS847, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to the surface of the undercoat layer by 0.2 g / m ² by bar coating, and then 140 A release agent layer was formed by curing in an oven at 30 ° C. for 30 seconds to obtain a release sheet.

<Example 8>
In Example 2, the same primer as in Example 2 was applied and dried to form a primer layer, and an ultraviolet curable silicone release agent (trade name: “Silicolys UV POLY200”, Arakawa on the surface of the primer layer. A release agent obtained by mixing 5 parts of a cationic polymerization type photoinitiator (trade name: “Silicolys UV CATA211”, manufactured by Arakawa Chemical Co., Ltd.) with 100 parts of Chemical Co., Ltd. was applied with a flexographic printing machine, and high-pressure mercury UV It hardened | cured on the conditions of the ultraviolet irradiation amount of 80 mJ / cm < ² > with the irradiation apparatus, the release agent layer was provided, and the peeling sheet of this invention was obtained. The coating amount of this release agent layer was 1.0 g / m ² in terms of solid content.

<Comparative Example 1>
"Manufacture of release sheet"
The same polypropylene base material as in Example 1 subjected to corona treatment was used, and an addition reaction type thermosetting was applied to the corona-treated surface of the base material (wetting index: 42 dyn / cm according to a method according to JIS-K6768-1977). The release agent layer is formed by curing 0.2 g / m ^{2 of the} conductive silicone release agent (trade name: KS847, manufactured by Shin-Etsu Chemical Co., Ltd.) by bar coating and then curing in an oven at 140 ° C. for 30 seconds. A release sheet was obtained.

<Comparative Example 2>
"Manufacture of release sheet"
A corona-treated surface of the same polypropylene-based synthetic paper substrate [trade name: YUPO (SGS80)] as in Example 3 was used, and a corona-treated surface of the substrate (method according to JIS-K6768-1977) After applying 0.2 g / m ² of bar-coating addition reaction type silicone release agent (trade name: KS847, manufactured by Shin-Etsu Chemical Co., Ltd.) to a wetting index of 42 dyn / cm), an oven at 140 ° C. The release agent layer was formed by curing for 30 seconds to obtain a release sheet.

<Comparative Example 3>
"Formation of primer layer"
A primer layer is formed in the same manner as in Example 1 except that 1 g / m ² of water-soluble polyester resin (trade name: Plus Coat Z-221, manufactured by Kyoyo Chemical Industry Co., Ltd.) is applied as a primer by bar coating. did.

"Manufacture of release sheet"
A release agent layer was formed on the undercoat layer in the same manner as in Example 1 to obtain a release sheet.

<Comparative Example 4>
"Formation of primer layer"
Undercoat layer as in Example 1, except that 0.2 g / m ² of silane coupling agent (trade name: X-92-185, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied as a primer by bar coating. Formed.

"Manufacture of release sheet"
A release agent layer was formed on the undercoat layer in the same manner as in Example 1 to obtain a release sheet.

<Comparative Example 5>
"Manufacture of release sheet"
The same polyethylene terephthalate film substrate (trade name: E5000) as in Example 4 provided with the same antistatic layer as in Example 6 was used, and the surface of the substrate provided with the antistatic layer was subjected to an addition reaction type silicone. After applying 0.2 g / m ² of a bar-type release agent (trade name: KS847, manufactured by Shin-Etsu Chemical Co., Ltd.) by bar coating, a release agent layer is formed by curing in an oven at 140 ° C. for 30 seconds, A release sheet was obtained.

(Evaluation)
Adhesiveness to the substrate of the primer layer of the release sheet obtained as described above or a layer containing a silicone curing inhibitor applied to the substrate, curability of the release agent of the release agent layer, and the primer layer The results are shown in Table 1.

Test 1: “Adhesiveness of primer layer to base material or silicone curing inhibitor-containing layer”
The release sheets obtained in Examples 1 to 8 and Comparative Examples 1 to 5 were used as samples. Using each of the obtained samples, the adhesion was evaluated according to the following criteria.
(Adhesion: Evaluate the degree of drop-off of the primer layer when the surface of the primer layer is rubbed with a finger 5 times)
(Double-circle): There is no drop-off at all and adhesion is very excellent.
○: No dropout and sufficient adhesion.
X: There is omission and adhesion is insufficient.

Test 2: “Curing property of release agent and adhesion to undercoat layer”
The curability of the release agent and the adhesion to the undercoat layer were evaluated by the following method using a finger rub method.
(Curability: Visual evaluation of the surface condition after lightly rubbing the surface of the silicone release layer with a finger)
A: There is no trace of rubbing, and curing is extremely excellent.
○: No rubbing marks remain and curing is sufficient.
X: Rubbed traces remain and curing is insufficient.
(Adhesion: Evaluates the degree of removal of the release agent layer when the silicone release layer surface is rubbed with a finger for 5 reciprocations)
(Double-circle): There is no drop-off at all and adhesion is extremely excellent.
○: No dropout and sufficient adhesion.
X: There is omission and adhesion is insufficient.

"Comprehensive evaluation"
As a comprehensive evaluation, the following criteria were used.
(Standard)
◎: Extremely good practicality ○: Good practicality ×: Insufficient practicality

  As described above in detail, according to the present invention, the silicone curing inhibitor contained in the base material or the layer coated on the base material does not migrate to the silicone release layer, and supports a wide variety of adhesives. A possible release sheet is provided.

Claims (9)

  An undercoat layer containing animal wax on one side of a film substrate containing a curing inhibitor for a silicone release agent, and addition reaction type thermosetting silicone, ultraviolet curable silicone, electron beam curing on the surface of the undercoat layer. A release sheet comprising a release layer comprising at least one kind of cured layer selected from type silicones sequentially laminated.   An undercoat layer containing animal wax on the surface of the coating layer of the film base material on which a layer containing a curing inhibitor of the silicone release agent is formed, and an addition reaction type thermosetting type on the surface of the undercoat layer A release sheet comprising a release layer comprising at least one kind of cured layer selected from silicone, ultraviolet curable silicone, and electron beam curable silicone, which are sequentially laminated.   The release sheet according to claim 1 or 2, wherein the animal wax contained in the primer layer is at least one selected from insect wax, whale wax, and wool wax.   The release sheet according to any one of claims 1 to 3, wherein the animal wax contained in the undercoat layer is shellac. The coating amount of the primer layer is a release sheet according to any one of claims 1 to 4, characterized in that a dry weight is 0.1~10.0g / ^{m 2.} The release sheet according to any one of claims 1 to 5, wherein the coating amount of the release agent layer is 0.05 to 3.0 g / m ² in terms of dry mass.   The release sheet according to any one of claims 1 to 6, wherein the film substrate is one selected from a polyolefin film, a polypropylene synthetic paper, a polyester film, and a polyvinyl alcohol film. .   The curing inhibitor is at least one selected from sulfur, organic sulfur compounds, organic tin compounds, amine compounds, organic phosphorus compounds, organic peroxides, glycerol, glycols, and tetrahydrofurfuryl derivatives. The release sheet according to any one of claims 1 to 7.   The release sheet according to any one of claims 1 to 8, wherein the curing inhibitor is a plasticizer or an antistatic agent.