JP6700560B2 - Release film - Google Patents

Description

  The present invention relates to a laminate, and more particularly to a laminate that can be suitably used for a release film in which an adhesive layer is formed on the surface of the laminate and is peeled off from the adhesive layer during use.

  A transparent polyester film has been widely used in recent years as a protective film used for manufacturing an optical film such as a liquid crystal polarizing plate and a retardation plate. Particularly, a release film based on a polyester film is used for protecting an adhesive layer. It is used as a release film.

  The adhesive layer of the optical film exerts its function by being bonded to a predetermined material after being peeled from the release film. Therefore, the basic function of the release film is to maintain and protect the adhesive force of the adhesive layer even under various storage environments and storage periods. Further, the release film is required to contribute to labor saving, speeding up, and yield increase of the laminating process in addition to the above-mentioned basic functions.

  Specifically, from the viewpoint of productivity, the peeling force when peeling the release film from the adhesive layer is low regardless of the peeling speed, or after peeling the release film from the adhesive layer, a release film or "Antistatic property" is required from the viewpoint of preventing deterioration of quality and adhesion of dust due to charging of the adhesive layer.

  Furthermore, in the step of forming the adhesive layer, foreign matter does not occur due to migration and precipitation of the low molecular weight component (oligomer) of the release film substrate to the adhesive layer side (hereinafter referred to as "oligomer block property"), and release. It is also required that the release layer does not elute when the pressure-sensitive adhesive is applied onto the mold film and dried (hereinafter referred to as “solvent adhesion”).

  In contrast to the above-mentioned four properties required for this release film, in Patent Document 1, "one side of a laminated polyester film containing core-shell type particles having an average particle size of 0.5 to 3.0 µm in the surface layer, A coating agent having an A layer obtained by applying a coating liquid containing a polymer containing a primary ammonium base, an acrylate polymer containing a polyethylene glycol, and a crosslinking agent, and containing at least one organosiloxane compound on the A layer. Is a polyester film having a B layer having a thickness of 10 to 100 nm, which is formed by applying the above. A release polyester film having a release layer on the B layer is proposed.

  In Patent Document 2, "A biaxially stretched polyester film has an undercoat layer obtained by applying a coating solution containing a quaternary ammonium group-containing polymer and a polyvalent aldehyde compound on one surface and drying the coating solution. A release film characterized by having a release layer on the pulling layer has been proposed.

  Further, in Patent Document 3, "A polyester film and an antistatic release polyester film having an antistatic release layer containing an antistatic agent and a release agent on at least one surface thereof, wherein the antistatic agent is a polyoxyalkylene A chain-containing cationic polymer, wherein the cationic polymer is a structural unit A formed from a monomer represented by the following formula (1) or the following formula (2), and the following formula (3) or the following formula (4) ) Comprising a structural unit B formed from a monomer represented by the formula (1), the release agent is a silicone compound, and the content is 20% by weight or more based on the weight of the antistatic release layer. A featured antistatic releasable polyester film has been proposed.

In Patent Document 4, "A release film for an antistatic surface protective film, which is capable of transferring an antistatic agent to the surface of the adhesive layer of an antistatic surface protective film having an adhesive layer formed on one surface of a base film. The release film for an antistatic surface protective film, on one surface of the resin film, a release agent layer containing a release agent containing dimethylpolysiloxane as a main component and an antistatic agent that does not react with the release agent. Laminated, the component of the antistatic agent is an ionic compound having a melting point of less than 30 ℃, the release film for the antistatic surface protective film, on the surface of the pressure-sensitive adhesive layer through the release agent layer A release film for an antistatic surface protective film, which is characterized in that the antistatic agent of the release agent layer can be transferred to the surface of the pressure-sensitive adhesive layer when laminated, has been proposed.

JP, 2005-62999, A JP, 2014-226924, A Japanese Patent No. 5623767 JP, 2016-130016, A

In the background art, the problems to be achieved by the laminate of the present invention are summarized as the following 5 points.
1. 1. When the pressure-sensitive adhesive layer is formed on the surface of the laminate and then the pressure-sensitive adhesive layer is peeled off, the peeling force is low. 2. When the adhesive layer is formed on the surface of the laminate and then the adhesive layer is peeled off, the electrostatic charge of the adhesive layer is small. 3. When the pressure-sensitive adhesive layer is formed on the surface of the laminate and then the pressure-sensitive adhesive layer is peeled off, the charge of the laminate is small. 4. The surface of the laminate has an oligomer block property. The surface of the laminate has solvent resistance adhesion.

  On the other hand, the present inventors have confirmed that the above-mentioned known technique is in the following situations.

  The technique of Patent Document 1 has a good oligomer block property, but insufficient antistatic properties on the laminate side and the adhesive layer side. The technology of Patent Document 2 is also good in oligomer blocking property and antistatic property on the laminate side, but is insufficient in antistatic property on the adhesive layer side and solvent adhesion resistance. In the technique of Patent Document 3, the antistatic property on the laminate side is good, but the antistatic property on the adhesive layer side, the oligomer block property and the solvent resistance adhesion are insufficient. The technology of Patent Document 4 has good antistatic property on the pressure-sensitive adhesive layer side when peeled between the pressure-sensitive adhesive layer and the release agent layer, but insufficient antistatic property on the release agent layer side and insufficient oligomer block property of the release film. Is. From the above points, the above five items could not be satisfied even if any of these techniques or a combination of these techniques were performed.

  Note that the present inventors considered the problems of the prior art as follows. First, the reason why the technology described in Patent Document 1 has insufficient antistatic properties is due to the laminated constitution, and the layer A containing the quaternary ammonium salt group-containing polymer used as the antistatic agent is the layer B on the layer A, Furthermore, since the layer C is laminated on the layer B, the distance from the outermost surface that requires antistatic properties is large, and as a result, the ability to reduce peeling charge when the adhesive layer is peeled off from the release film is low, It is considered that the antistatic properties of the release layer and the adhesive layer are low.

  The reason why the solvent adhesion is insufficient in the technique described in Patent Document 2 is that the coating layer between the supporting substrate and the release layer has weak adhesion to the release layer. The reason for this is that the film forming component of the coating layer and the base material and the film forming component of the release layer have low compatibility. In addition, the reason why the antistatic property of the adhesive layer side is insufficient is that the existence position of the quaternary ammonium salt group-containing polymer used as the antistatic agent is away from the interface between the adhesive layer and the laminate surface which causes peeling electrification. thinking.

  The reason why the technology described in Patent Document 3 has an insufficient oligomer blocking property is that only the antistatic release layer is the object that blocks the oligomer supplied from the polyester film substrate to the surface. Believes that since a silicone compound having a low density and the antistatic agent contain a cationic polymer containing a polyoxyalkylene chain, they easily pass through an oligomer. In addition, the reason why the antistatic property of the adhesive layer side is insufficient is that the presence of the quaternary ammonium salt group-containing polymer used as an antistatic agent is uniform in the release layer, and the adhesive layer originally required for suppressing the peeling electrostatic charge. It is considered that it is separated from the interface formed by the release layer surface.

  In the technique described in Patent Document 4, the reason why the oligomer block property of the release film becomes insufficient is that the release agent layer provided on one surface of the resin film is a release agent containing dimethylpolysiloxane as a main component Since it contains an antistatic agent that does not react with the agent, it is thought that the density is low and the oligomer easily passes through. Also, when peeling between the pressure-sensitive adhesive layer and the release agent layer, the antistatic agent on the pressure-sensitive adhesive layer side is good, but the reason why the antistatic agent on the release agent layer side is insufficient is that the antistatic agent on the release agent layer peels off. It is considered that, because the antistatic component on the side of the release agent layer is reduced and the antistatic performance is lowered because the transfer is sometimes made to the surface of the pressure-sensitive adhesive layer.

  With respect to the above-mentioned five problems, the present inventors have proposed a laminate having a layer A and a layer B on at least one surface of a supporting base material in this order from the supporting base material side. It has been found that it is preferable that the layer B contains an onium salt, and the layer B contains an onium salt and polydimethylsiloxane, and the concentration distribution of the onium salt in the thickness direction in the layer B of the laminate has a specific form. .. In addition, the concentration distribution of the onium salt in the thickness direction in the layer B means that the layer B is divided into regions X, Y, and Z (where the region Z is a layer A including both the layer A and the layer B) as described later. The distribution of the concentration of the onium salt in each of the areas X, Y, and Z when the area is divided into the area B). That is, the inventors of the present invention have made the following inventions as a result of earnest studies in view of the actual situation of the prior art.

1. A laminate having a layer A and a layer B on at least one surface of a supporting substrate in this order from the side of the supporting substrate, wherein the layer A contains an onium salt, and the layer B contains an onium salt and polydimethylsiloxane. The concentration of the onium salt in the outermost surface region of the layer B (region X), the central region of the layer B (region Y), and the region of the interface between the layers A and B (region Z) in the thickness direction is as follows. A laminate satisfying the formula (1) or (2).
Area X≧area Z>area Y... Formula (1)
Area Z>area X>area Y... Equation (2).

2. A laminate having a layer A and a layer B on at least one surface of a supporting substrate in this order from the side of the supporting substrate, wherein the layer A contains an onium salt, and the layer B contains an onium salt and polydimethylsiloxane. Including the outermost surface area of the layer B (area V), the central area of the layer B (area S), the central area of the layer A (area T), and the interface between the layer A and the supporting substrate. In the region (region W), the onium salt concentration satisfies the following formula (3) or (4).
Region V≧region W>region S and region T... Formula (3)
Area W>area V>area S and area T... Equation (4).

  3. 3. The layered product according to 1 or 2, wherein the layer A contains a polyalkoxysiloxane and a metal chelate compound.

  4. 4. The laminated body according to any one of 1 to 3, wherein the onium salt is an ionic liquid.

5. The laminated body has a polyester oligomer amount of 0.1 mg/m ² or less by dimethylformamide extraction after heat treatment at 180° C. for 10 minutes, and has a circumscribed diameter of 30 μm or more on the surface of layer B by a glass plate inspection method. The number of foreign matter defects is 2/50 cm ² or less, the laminate according to any one of 1 to 4.

  According to the present invention, when the pressure-sensitive adhesive layer is formed on the surface of the laminate and then the pressure-sensitive adhesive layer is peeled off, the peeling force of the pressure-sensitive adhesive layer is low, and when the laminate is peeled off from the pressure-sensitive adhesive layer, it occurs on the surface of the laminate and the pressure-sensitive adhesive layer. It is possible to obtain a laminate having a small peel-off charge and excellent oligomer block property and solvent adhesion of the release layer of the laminate.

It is sectional drawing explaining the laminated body of this invention. It is sectional drawing explaining the laminated body of this invention.

Embodiments of the present invention will be specifically described. In addition, in this invention, a laminated body is a release film.

  The “onium salt” contained in the layer A and the layer B in the present invention is a salt containing a cation (cation) compound and an anion (anion) compound, and is a cation (cation) generated by protonation of a hydride. Refers to a salt containing a compound. Specific examples of the onium salt include a bromonium salt, an iodonium salt, an oxonium salt, a sulfonium salt, an arsonium salt, an ammonium salt, a phosphonium salt, an imidazolium salt, and a pyridinium salt. The onium salt can exhibit antistatic properties.

  The method of containing the onium salt in the layer A is not particularly limited, but the layer A containing the onium salt can be formed by, for example, applying and drying the coating composition for the layer A containing the onium salt. The method of incorporating the onium salt in the layer B is not particularly limited, but for example, forming the layer B on the layer A during coating/drying of the coating composition for the layer A for forming the layer A containing the onium salt. Then, the onium salt contained in the layer A is transferred to the layer B to form the layer B containing the onium salt.

  The onium salt is preferably an ionic liquid. Here, the “ionic liquid” is a kind of salt containing a cation (cation) compound and an anion (anion) compound, and refers to a salt in a liquid state at 100° C. or lower. Ionic liquids are preferable because they exhibit high electric conductivity and can exhibit excellent antistatic properties, and are also preferable from the viewpoint of forming a concentration distribution of the onium salt in the layer B of the laminate in the thickness direction.

  Specific examples of the ionic liquid include imidazolium-based, pyridinium-based, ammonium-based, sulfonium-based, phosphonium-based, and iodine-based cation moieties, and anion moieties include sulfate-based, borate-based, phosphate-based, and sulfone-based compounds. There are acid type, halogen type, etc., which can be obtained by a combination thereof.

Further, the ionic liquid is preferably an ionic liquid composed of a cation compound described in the following cation compound group and an anion compound described in the anion compound group.
(Cationic Compound Group) At least one cation compound selected from the group consisting of phosphonium-based cation compounds, ammonium-based cation compounds and pyridinium-based cation compounds.
(Anion Compound Group) At least one anion compound selected from the group consisting of a fluorine-containing anion compound, a sulfonic acid anion compound, a carboxylic acid anion compound, and an inorganic acid anion compound.

  Specific examples of the phosphonium-based cation compound of the cation compound group include tetraalkylphosphonium cations and those in which a part of the alkyl group is substituted with an alkenyl group, tetramethylphosphonium cation, tetraethylphosphonium cation, tetrapropylphosphonium cation. , Tetrabutylphosphonium cation, tetrapentylphosphonium cation, tetrahexylphosphonium cation, tetraheptylphosphonium cation, tetraoctylphosphonium cation, tetranonylphosphonium cation, tetradecylphosphonium cation, tetradodecylphosphonium cation, tributylmethylphosphonium cation, trihexyltetradecyl Phosphonium cation, triphenylmethylphosphonium cation, triphenylethylphosphonium cation, triphenylbutylphosphonium cation, triphenylheptylphosphonium cation, triphenyldodecylphosphonium cation, triphenylhexadecylphosphonium cation, triphenylbenzylphosphonium cation, tetraphenylphosphonium cation and so on. Specific examples of the ammonium-based cation compound, tetraalkylammonium cation, a part of the alkyl group is substituted with an alkenyl group, piperidinium cation, pyrrolidinium cation, morpholinium cation, bipyrrolidinium cation, Bipiperidinium cation and the like, tetramethyl ammonium cation, tetraethyl ammonium cation, tetrapropyl ammonium cation, tetrabutyl ammonium cation, tetrapentyl ammonium cation, tetrahexyl ammonium cation, tetraheptyl ammonium cation, tetraoctyl ammonium cation, tetra Nonyl ammonium cation, tetradecyl ammonium cation, tetradodecyl ammonium cation, tetraallyl ammonium cation, trioctyl methyl ammonium cation, didecyl dimethyl ammonium cation, dioleyl dimethyl ammonium cation, trimethyl hexadecyl ammonium cation, 1,1-dimethyl piperidi Aluminum cation, 1-ethyl-1-methylpiperidinium cation, 1-methyl-1-propylpiperidinium cation, 1-butyl-1-methylpiperidinium cation, 1,1-dimethylpyrrolidinium cation, 1 -Ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-butyl-1-methylpyrrolidinium cation, 1,1'-spirobipyrrolidinium cation and the like. Specific examples of the pyridinium-based cation compound include 1-methylpyridinium cation, 1-ethylpyridinium cation, 1-propylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-octylpyridinium cation, 1-decylpyridinium cation. , 1-dodecylpyridinium cation, 1-hexadecylpyridinium cation, 1-methyl-2-methylpyridinium cation, 1-ethyl-2-methylpyridinium cation, 1-propyl-2-methylpyridinium cation, 1-butyl-2- Methylpyridinium cation, 1-hexyl-2-methylpyridinium cation, 1-octyl-2-methylpyridinium cation, 1-decyl-2-methylpyridinium cation, 1-dodecyl-2-methylpyridinium cation, 1-hexadecyl-2- Methylpyridinium cation, 1-methyl-3-methylpyridinium cation, 1-ethyl-3-methylpyridinium cation, 1-propyl-3-methylpyridinium cation, 1-butyl-3-methylpyridinium cation, 1-hexyl-3- Methylpyridinium cation, 1-octyl-3-methylpyridinium cation, 1-decyl-3-methylpyridinium cation, 1-dodecyl-3-methylpyridinium cation, 1-hexadecyl-3-methylpyridinium cation, 1-methyl-4- Methylpyridinium cation, 1-ethyl-4-methylpyridinium cation, 1-propyl-4-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-hexyl-4-methylpyridinium cation, 1-octyl-4- Methylpyridinium cation, 1-decyl-4-methylpyridinium cation, 1-dodecyl-4-methylpyridinium cation, 1-hexadecyl-4-methylpyridinium cation, 1-methyl-3,5-dimethylpyridinium cation, 1-ethyl- 3,5-dimethylpyridinium cation, 1-propyl-3,5-dimethylpyridinium cation, 1-butyl-3,5-dimethylpyridinium cation, 1-hexyl-3,5-dimethylpyridinium cation, 1-octyl-3, 5-dimethylpyridinium cation, 1-decyl-3,5-dimethylpyridinium cation, 1-dodecyl-3,5-dimethylpyridinium cation, 1-hexadecyl-3 , 5-dimethylpyridinium cation, 1-methyl-3,5-diethylpyridinium cation and the like.

  Specific examples of the fluorine-containing anion compound of the anion compound group include bis(perfluoroalkanesulfonyl)imide anion, perfluoroalkanesulfonate anion, perfluoroalkanecarboxylic acid anion, tetrafluoroborate anion, hexafluorophosphate anion, Alkane sulfonate anion, hexafluorophosphate anion, tetrafluoroborate anion, bis(trifluoromethanesulfonyl)imide anion, bis(pentafluoroethanesulfonyl)imide anion, (heptafluoropropanesulfonyl)imide anion, (nonafluorobutanesulfonyl)imide Anion, [(trifluoromethanesulfonyl)(pentafluoroethanesulfonyl)]imide anion, trifluoromethanesulfonate anion, pentafluoroethanesulfonate anion, heptafluoropropanesulfonate anion, nonafluorobutanesulfonate anion, heptadecafluorooctanesulfone Examples thereof include acid anion, trifluoroacetic acid anion, pentafluoropropionate anion, heptafluorobutanoic acid anion, and pentadecafluorooctanoic acid anion. Specific examples of the sulfonate anion compound include methanesulfonate anion, ethanesulfonate anion, butanesulfonate anion, octanesulfonate anion, paratoluenesulfonate anion, decylbenzenesulfonate anion, dodecylbenzenesulfonate anion, tetra Decylbenzene sulfonate anion and the like. Specific examples of the carboxylic acid anion compound include a formate anion, an acetate anion, a propionate anion, a butanoic acid anion, an octanoic acid anion, a decanoic acid anion, a benzoic acid anion, and a salicylate anion. Specific examples of the inorganic acid anion compound include a perchlorate anion, a nitrate anion, a sulfate anion, a phosphate anion, and a borate anion.

  The ionic liquid can obtain various physical properties by changing the types or combinations of the constituent cation compounds and anion compounds. Since the ionic liquid contained in the layer A is composed of the cation compound described in the above cation compound group and the anion compound described in the anion compound group, the oligomer blocking property and the solvent adhesion property are achieved while exhibiting the antistatic property. It is possible to do so, which is preferable.

  Next, the “polydimethylsiloxane” contained in the layer B in the present invention is a material having a basic skeleton of a structure of a polysiloxane skeleton composed of Si—O—Si having two methyl groups attached to Si, and is generally a silicone resin. Also called. As will be described later in detail, since the layer B contains polydimethylsiloxane, the laminate can be easily peeled between the adhesive layer and the layer B even when the surface is provided with the adhesive layer.

  The concentration distribution of the onium salt in the thickness direction in the layer B of the laminate is specifically as follows: the outermost surface region (region X) of the layer B in the thickness direction, the central region (region Y) of the layer B, the layer It is preferable that the concentration of the onium salt in the region (region Z) at the interface between A and layer B satisfies the following formula (1) or (2).

Area X≧area Z>area Y... Formula (1)
Region Z> Region X> Region Y... Formula (2)
In the laminate of the present invention, the presence of a large amount of onium salt in the two locations of the region Z and the region X forms an adhesive layer on the layer B of the laminate, and then when the adhesive layer is peeled off, the adhesive layer The charge can be reduced, and the charge of the laminate after peeling can also be reduced.

  The above formula (1) represents that the onium salt concentrations of the region X and the region Z are equal to each other, or the onium salt concentration of the region X is higher than that of the region Z. In addition, the onium salt concentration in the region Y is lower than that in the regions X and Z. By satisfying the formula (1), since a large amount of onium salt is present at two positions in the region X and the region Z, an adhesive layer is formed on the layer B of the laminate, and when the adhesive layer is peeled off, the adhesive layer is adhered. The charge of the layer can be reduced, and the charge of the laminate after peeling can also be reduced.

  The above formula (2) represents that the onium salt concentration in the region Z is the highest, the onium salt concentration in the region X is next high, and the onium salt concentration in the region Y is the lowest. By setting the concentration distribution of the onium salt as described above, when the pressure-sensitive adhesive layer is formed on the layer B of the laminate and then the pressure-sensitive adhesive layer is peeled off, the amount of the onium salt in the region X that migrates to the pressure-sensitive adhesive layer surface is very small. In addition, the charge of the laminate after peeling can be further reduced.

  The onium salt concentration in the region X is preferably 0.1% or more and 30% or less, more preferably 0.5% or more and 25% or less, and further preferably 1% or more and 20% or less. If the concentration of the onium salt in the region X exceeds 30%, the peel strength of the laminate may increase, and if it is less than 0.1%, an adhesive layer is formed on the layer B of the laminate, and then the adhesive layer is peeled off. At this time, the charge of the adhesive layer may increase.

  The onium salt concentration in the region Y is more preferably 1/2 or less of the concentration of the onium salt in the region X. It is desirable that the onium salt concentration in the region Y is low, but it is difficult to set the concentration to 0% in the method for producing a laminate of the present invention described later, and the lower limit value is about 0.05%. If the onium salt concentration in the region Y exceeds 1/2 of the onium salt concentration in the region X, poor curing of the layer B may occur, and the solvent resistance of the laminate may deteriorate.

  The onium salt concentration in the region Z is preferably 0.1% or more and 30% or less, more preferably 1% or more and 25% or less, and further preferably 5% or more and 25% or less. When the concentration of the onium salt in the region Z is less than 0.1%, when the adhesive layer is formed on the layer B of the laminate and then the adhesive layer is peeled off, the charge of the laminate may increase, and exceeds 30%. In some cases, poor curing of the layers A and B may occur, and the solvent resistance of the laminate may be reduced. The term "%" as used herein means the concentration (atm%) of an element characteristic of the onium salt contained in each region.

  Here, the positional relationship among the region X, the region Y, and the region Z is shown in FIG. FIG. 1 shows a cross section of a laminate of the present invention, in which a layer A2 and then a layer B3 are sequentially laminated on one surface of a supporting substrate 1. In this cross section, when a reference line 4 perpendicular to the supporting substrate is drawn, the intersection point with the surface of layer B is point α5, the intersection point between the interface of layer B and layer A is point γ7, and inside the layer B on the reference line. Let the point be point β6.

  The region X8 includes a range of 10 nm in the thickness direction from the point α and 10 nm to the left and right, the region Y9 includes the point β, the region other than the regions X and Z in the thickness direction, and the region Z10 includes the point γ. It refers to a range of 5 nm above and below the point γ and 10 nm to the left and right.

  A detailed calculation method of the concentration of the onium salt in each region will be described later, but element analysis is performed for each region of the laminate, and the intensity ratio of the obtained different element peaks is calculated as the concentration ratio, and included in the onium salt. The concentration of the characteristic element described above was defined as the concentration of the onium salt. The elemental analysis method is not particularly limited, but it can be analyzed using EDX, EELS, TOF-SIMS, or the like. Examples of characteristic elements contained in the onium salt include N element when an imidazolium salt or ammonium salt is used, P element when a phosphonium salt is used, S element when a sulfonium salt is used, Etc.

When the concentration distribution of the onium salt in the layer B of the laminated body in the thickness direction satisfies the above-mentioned condition, an adhesive layer is formed on the layer B of the laminated body, and then when peeled, the adhesive layer side and the laminated body Both peeling charges can be reduced. About the mechanism,
When the adhesive layer is formed on the layer B of the laminate, the onium salt is present at a high concentration in two places, that is, the interface between the adhesive layer and the laminate, and the interface between the layers A and B of the laminate. When the pressure-sensitive adhesive layer is peeled from the laminate between the pressure-sensitive adhesive layer and the layer B, the onium salt is present on the surface of the peeled pressure-sensitive adhesive layer and the layer B, so that the charge sequence on the surface becomes closer and the peeling charge amount becomes smaller. Since the onium salt is present on the surface of the adhesive layer, it is possible to instantly leak and attenuate the charge due to the peeling charge. Further, the charge on the release film side is also reduced by forming a conductive path at a portion having a high onium salt concentration existing at the interface between the layer B and the layer A.

  The method for achieving the concentration distribution of the onium salt in the thickness direction in the layer A and the layer B of the laminate is not particularly limited, but the layer A coating composition and the layer B coating composition described below are referred to as a layered product. It is preferable to form by applying and drying by the manufacturing method of.

Further, the concentration distribution of the onium salt in the thickness direction in the layers B and A of the laminate is specifically, the outermost surface region of the layer B (region V) in the thickness direction, and the central region of the layer B ( The concentration of the onium salt in the region S), the central region of the layer A (region T), and the region of the interface between the layer A and the supporting substrate (region W) may satisfy the following formula (3) or (4). preferable.
Region V≧region W>region S and region T... Formula (3)
Area W>area V>area S and area T... Equation (4).

  In the laminate of the present invention, the presence of a large amount of onium salt in the two locations of the region V and the region W forms an adhesive layer on the layer B of the laminate, and then when the adhesive layer is peeled off, the adhesive layer It is possible to reduce the electrification and the electrification of the laminate after peeling, and further improve the solvent adhesion.

  The above formula (3) represents that the onium salt concentrations of the region V and the region W are equal to each other, or the onium salt concentration of the region V is higher than that of the region W. Further, it is shown that the onium salt concentrations in the regions S and T are lower than those in the regions V and W. By satisfying the formula (3), since a large amount of onium salt is present in two regions V and W, a pressure-sensitive adhesive layer is formed on the layer B of the laminate, and when the pressure-sensitive adhesive layer is peeled off, a pressure-sensitive adhesive layer is formed. The charge of the layer can be reduced, and the charge of the laminate after peeling can also be reduced.

  The above formula (4) represents that the onium salt concentration in the region W is the highest, the onium salt concentration in the region V is next high, and the onium salt concentration in the regions S and T is the lowest. By setting the concentration distribution of the onium salt as described above, when the pressure-sensitive adhesive layer is formed on the layer B of the laminate and then the pressure-sensitive adhesive layer is peeled off, the amount of the onium salt in the region V that migrates to the pressure-sensitive adhesive layer surface is very small. In addition to reducing the electrostatic charge of the laminate after peeling, the solvent resistance and adhesion can be improved.

  The onium salt concentration in the region V is preferably 0.1% or more and 30% or less, more preferably 0.5% or more and 25% or less, and further preferably 1% or more and 20% or less. If the concentration of the onium salt in the region X exceeds 30%, the peel strength of the laminate may increase, and if it is less than 0.1%, an adhesive layer is formed on the layer B of the laminate, and then the adhesive layer is peeled off. At this time, the charge of the adhesive layer may increase.

  The concentration of the onium salt in the region S is more preferably 1/2 or less of the concentration of the onium salt in the region V. Although it is desirable that the concentration of the onium salt in the region S is low, it is difficult to set the concentration to 0% in the method for producing a laminate of the present invention described later, and the lower limit value is about 0.05%. When the concentration of the onium salt in the region S exceeds 1/2 of the concentration of the onium salt in the region V, poor curing of the layer B may occur and the solvent-resistant adhesiveness of the laminate may deteriorate.

  The concentration of the onium salt in the region T is more preferably 1/2 or less of the concentration of the onium salt in the region W. It is desirable that the onium salt concentration in the region T is low, but it is difficult to set it to 0% by the method for producing a laminate of the present invention described later, and the lower limit value is about 0.05%. When the onium salt concentration in the region T exceeds 1/2 of the onium salt concentration in the region W, poor curing of the layer A may occur, resulting in a decrease in solvent resistance adhesion of the laminate and a decrease in oligomer block property. is there.

  The onium salt concentration in the region W is preferably 0.1% or more and 30% or less, more preferably 1% or more and 30% or less, and further preferably 5% or more and 30% or less. When the concentration of the onium salt in the region W is less than 0.1%, when the adhesive layer is formed on the layer B of the laminate and then the adhesive layer is peeled off, the charge of the laminate may increase, and exceeds 30%. If so, curing failure of the layer A may occur, and the solvent-resistant adhesiveness of the laminate may be deteriorated, and the oligomer block property may be deteriorated. The term "%" as used herein means the concentration (atm%) of an element characteristic of the onium salt contained in each region.

  Here, the positional relationship among the region V, the region S, the region T, and the region W is shown in FIG. FIG. 2 shows a cross section of the laminate of the present invention, in which the layer A12 and then the layer B13 are sequentially laminated on one surface of the supporting substrate 11. The laminate shown in FIG. 1 and the laminate shown in FIG. 2 are both laminates having layer A and layer B on at least one surface of the supporting base material in this order from the supporting base material side. 1 and FIG. 2 are laminates having the same structure in terms of the structure of the supporting base material, the layer A and the layer B. In this section, when a reference line 14 perpendicular to the supporting substrate is drawn, the intersection point with the surface of the layer B is point ε15, the midpoint of the layer B on the reference line is σ16, and the midpoint of the layer A on the reference line is The point ω17 and the intersection of the layer A and the interface of the supporting substrate are point η18.

  A region V19 has a range of 10 nm in the thickness direction from the point ε, and a range of 10 nm from the point ε to the left and right, and a region S20 includes a point σ and has a range of 5 nm vertically around the point σ and 10 nm horizontally from the point σ. The region T21 includes a point ω, and has a range of 5 nm above and below the point ω, 10 nm to the left and right around the point ω, and a region W22 is 10 nm from the point η in the layer A12 direction and 10 nm to the left and right from the point η. Refers to a range.

  A detailed calculation method of the concentration of the onium salt in each region will be described later, but element analysis is performed for each region of the laminate, and the intensity ratio of the obtained different element peaks is calculated as the concentration ratio, and included in the onium salt. The concentration of the characteristic element described above was defined as the concentration of the onium salt. The elemental analysis method is not particularly limited, but it can be analyzed using EDX, EELS, TOF-SIMS, or the like. Examples of characteristic elements contained in the onium salt include N element when an imidazolium salt or ammonium salt is used, P element when a phosphonium salt is used, S element when a sulfonium salt is used, Etc.

  When the concentration distribution of the onium salt in the layer B and layer A of the laminated body in the thickness direction satisfies the above-mentioned conditions, an adhesive layer is formed on the layer B of the laminated body, and then, when peeled, the adhesive layer side The peeling charge of both the laminate and the laminate can be lowered, and the solvent adhesion can be further improved. The mechanism is that when an adhesive layer is formed on the layer B of the laminate, the onium salt is present at a high concentration in two places: the interface between the adhesive layer and the laminate, and the interface between the layer A of the laminate and the supporting substrate. Will be done. When the pressure-sensitive adhesive layer is peeled from the laminate between the pressure-sensitive adhesive layer and the layer B, the onium salt is present on the surface of the peeled pressure-sensitive adhesive layer and the layer B, so that the charge sequence on the surface becomes closer and the peeling charge amount becomes smaller. Since the onium salt is present on the surface of the adhesive layer, it is possible to instantly leak and attenuate the charge due to the peeling charge. Further, the charge on the side of the release film is also reduced by forming a conductive path in the portion having a high concentration of onium salt existing at the interface between the layer A and the supporting base material. Further, since a large amount of onium salt is present at the interface between the layer A and the supporting substrate, even when an adhesive (solvent) from which the onium salt is easily extracted is used, the amount of the onium salt transferred to the surface of the adhesive layer is very small. And the resistance to solvent adhesion can be improved.

  The method for achieving the concentration distribution of the onium salt in the thickness direction in the layer A and the layer B of the laminate is not particularly limited, but the layer A coating composition and the layer B coating composition described below are referred to as a layered product. It is preferable to form by applying and drying by the manufacturing method of.

  The layer A preferably contains polyalkoxysiloxane and a metal chelate compound. Here, the term “polyalkoxysiloxane” means that segments having a siloxane skeleton made of Si—O—Si as a repeating unit are regularly or randomly linked from one dimension to three dimensions, and an alkoxy group is present at the remaining site on Si. Those having a functional group other than an alkoxy group, those having an alkoxy group converted to a silanol group by hydrolysis, and those having a silanol group crosslinked through a metal chelate are also included.

  When the layer A contains a polyalkoxysiloxane, the functional group such as a silanol group or an alkoxy group is present, so that the layer A has an affinity with the substrate, and the layer A further contains a siloxane skeleton. Both of these are preferred because they provide an affinity and improve the solvent adhesion of the laminate. Further, polydimethylsiloxane is preferable from the viewpoint of oligomer blockability because it can form a dense film and is a material with a large polarity, and thus it is difficult for hydrophobic oligomers to pass through. From the viewpoint of control, it is preferable for forming the concentration distribution of the onium salt in the layer B of the laminate in the thickness direction.

Polyalkoxysiloxane is obtained by hydrolysis of alkoxysilane and further silanol condensation. Here, the alkoxysilane is a compound represented by Chemical Formula 1 or Chemical Formula 2, n is an integer of 0 to 3, m is an integer of 0 to 2, R ¹ is a (meth)acryl group, an epoxy group, a vinyl group, a phenyl group. , An amino group, etc., R ² is an alkyl group having 1 to 4 carbon atoms, R ³ is an alkylene group having 1 to 3 carbon atoms and an ester structure derived therefrom, R ⁴ is hydrogen or alkyl having 1 to 4 carbon atoms Groups are preferred.

  Specifically, polyalkoxy siloxanes include (meth)acryloxy (mono, di, tri) alkoxy silanes, epoxy (mono, di, tri) alkoxy silanes, vinyl (mono, di, tri) alkoxy silanes, phenyl (mono, di, A hydrolyzed condensate of at least one alkoxysilane selected from the group consisting of tri)alkoxysilanes, amino (mono-, di-, tri)alkoxysilanes, and tetraalkoxysilanes; A mixture thereof is preferable, and a hydrolysis-condensation product of tetraalkoxysilane, a cross-linked product of a hydrolysis-condensation product with a metal chelate, and a mixture thereof can form a dense siloxane bond in the layer A. Therefore, it is more preferable from the viewpoint of the oligomer block property and the concentration distribution of the onium salt in the layer B of the laminate in the thickness direction.

  Further, the polyalkoxysiloxane of the present invention is a group consisting of the tetraalkoxysilane, epoxy (mono, di, tri)alkoxysilane, phenyl (mono, di, tri)alkoxysilane, and methyl (mono, di, tri)alkoxysilane. The organic group in the layer A exhibits adhesion to the supporting substrate by being a hydrolysis-condensation product with at least one alkoxysilane selected from the following, a cross-linking product of the hydrolysis-condensation product with a metal chelate, and a mixture thereof. It is more preferable from the viewpoint of the concentration distribution of the onium salt in the thickness direction in the layer B to the layer A of the laminated body, since it is possible to increase the solvent resistance.

  The structure of the siloxane skeleton of the polyalkoxysiloxane generally has types such as “ladder”, “cage”, and “random”. However, in the layer A of the laminate of the present invention, oligomer blockability and From the viewpoint of forming the concentration distribution of the onium salt in the thickness direction in the layer B of the laminated body, it is preferable that a ladder-like or cage-like ratio in which a dense layer is obtained is large.

  The method for forming the polyalkoxysiloxane contained in the layer A is not particularly limited, and a coating composition containing the above-mentioned alkoxylane monomer is applied as a coating composition for the layer A described later on a supporting substrate, The coating film may be hydrolyzed and condensed in the steps of drying and curing, or a hydrolysis-condensation product of an alkoxysilane may be formed in advance, and the coating composition for layer A containing the same may be applied and dried. However, the latter is more preferable from the viewpoint of forming an oligomer block property and a concentration distribution of the onium salt in the layer B of the laminate in the thickness direction. Further, as the coating composition for layer A, a hydrolysis-condensation product of an alkoxysilane is formed in advance, and a coating composition for layer A containing a mixture of a part of alkoxysilane monomers is applied and dried. This is preferable from the viewpoint of solvent resistance adhesion and formation of a concentration distribution of the onium salt in the layer B and layer A of the laminate in the thickness direction.

  The “metal chelate” is a compound in which only a ligand (polydentate ligand) having a plurality of coordination atoms with respect to a metal element is coordinated, a salt of a metal element and an alcohol (a metal alkoxy salt, a metal). A compound in which a part of (alcoholate) is replaced with the above-mentioned polydentate ligand, and an oligomer thereof are referred to.

  The metal element of the metal chelate is preferably at least one selected from aluminum, titanium, zirconium, zinc and iron, and the polydentate ligand is a β-ketoester such as acetylacetone, ethyl acetoacetate, diethyl malonate, or β-diketone. , Β diesters are preferred. Specific materials will be described later. When the layer A contains a metal chelate, the polyalkoxysiloxane can be crosslinked in the layer A via metal ions. Therefore, in addition to the solvent adhesion resistance and the oligomer block property, the layer A in the layer B of the laminate is It is also effective in forming a concentration distribution of the onium salt in the thickness direction.

  Examples of the metal chelate containing aluminum element include aluminum tris(acetylacetonate), aluminum monoacetylacetonate bis(ethylacetoacetate), aluminum-di-n-butoxide-monoethylacetoacetate, Aluminum-di-iso-propoxide-monomethylacetoacetate, aluminum tris(ethylacetoacetate) and the like are exemplified. Examples of metal chelates containing titanium element are titanium beta esters such as tetramethyl titanate; titanium acetylacetonate, titanium tetraacetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate, titanium triethanol. Aminates, titanium ethyl acetoacetates and the like are exemplified.

  Specific examples of the metal chelate containing a zirconium element include zirconium tetraacetylacetonate, zirconium monoacetylacetonate, and zirconium bisacetylacetonate.

The laminate of the present invention preferably has a polyester oligomer deposition amount within a specific range when treated under specific conditions. Specifically, preferably, the amount of the polyester oligomer by the dimethylformamide extraction on the surface of the layer B of the laminate after heat treatment at 180° C. for 10 minutes is 0.1 mg/m ² or less, more preferably 0 mg/m ² . .. When the amount of the polyester oligomer by dimethylformamide extraction on the surface of the layer B of the laminate after heat treatment at 180° C. for 10 minutes is higher than 0.1 mg/m ² , for example, the laminate of the present invention is used as a pressure-sensitive adhesive layer for a polarizing plate. When used as a release film of polyester, the polyester oligomer may transfer to the adhesive of the polarizing plate to form particles in the layer, and when it is finally attached to the display, many pixel defects may occur. ..

Further, the laminate of the present invention, preferably, the foreign matter defect number of the circumscribed diameter 30μm or more in size by the glass plate inspection method, two / 50 cm ² or less, more preferably 0/50 cm ² or less. When the number of defects of foreign matter having a circumscribed diameter of 30 μm or more by the glass plate inspection method is 2 pieces/50 cm ² or less, the brightness abnormality of the LCD screen is not conspicuous and good optical characteristics can be exhibited. The "circumscribed diameter" referred to here is the diameter of the smallest circle that completely encloses (circumscribes) the foreign matter defect. Hereinafter, each component of the present invention will be described in detail.

[Laminate]
The laminated body of the present invention may have the layer A and the layer B satisfying the above-described conditions in this order from at least one side of the supporting base material in this order, and on both sides of the supporting base material. You may have the layer A and the layer B in this order from the support base material side.

  Here, the "layer" in the present invention is a boundary between the surface of the laminate in the thickness direction, the composition of the constituent elements with adjacent portions, the shape of inclusions such as particles, and the physical properties in the thickness direction that are discontinuous. A part having a finite thickness that is distinguished by having a surface. More specifically, various compositions/elemental analyzers (FT-IR, XPS, XRF, EDAX, SIMS, EPMA, EELS, etc.), electron microscopes (transmission type, scanning type) or This refers to a portion having a finite thickness, which is distinguished by the discontinuous boundary surface when a cross-section is observed with an optical microscope.

[Layer A]
In the laminate of the present invention, an oligomer block property that suppresses the surface migration of low molecular weight components from the supporting base material, solvent resistance adhesion to layer B and the supporting base material, and an adhesive layer formed on layer B of the laminated body. Then, from the viewpoint of antistatic properties of both the adhesive layer and the laminate when the adhesive layer is subsequently peeled off, it is preferable to provide one or more layers A containing an onium salt on the supporting substrate, and the polyalkoxysiloxane and the metal. More preferably, it contains a chelate compound. The laminate of the present invention may be provided with a plurality of layers A depending on the function. Further, the layer A may be provided on both surfaces of the supporting base material.

  The method for forming the layer A is not particularly limited as long as the above conditions can be satisfied, but it is preferable that the coating composition for layer A described below is formed by the method for laminating a laminate described below. The layer A may be formed by coating a coating composition for layer A, which will be described later, on the way of forming the supporting substrate, or after forming the supporting substrate, the coating composition for the layer A is used as a supporting substrate. It may be applied to a material, dried, and wound.

  The coating thickness of the layer A after drying is preferably 10 to 500 nm, more preferably 15 to 200 nm, still more preferably 15 to 100 nm. When the coating thickness is 10 nm to 500 nm, the oligomer blocking property, the solvent resistance adhesion to layer B and the supporting base material, the pressure-sensitive adhesive layer when the pressure-sensitive adhesive layer is formed on layer B of the laminate, and then the pressure-sensitive adhesive layer is peeled off It is preferable because both the antistatic property and the laminate can be obtained and the excellent coating film quality can be obtained.

[Coating composition for layer A, resin composition precursor]
The coating composition for layer A is applied on a supporting base material and dried, whereby the layer A contains an onium salt, and the concentration distribution of the onium salt in the thickness direction in the layer B of the laminate has the above specific conditions. The coating composition for layer A preferably contains an onium salt, more preferably contains an onium salt, a metal chelate, and a polyalkoxysiloxane or a precursor thereof, and is particularly preferably an ionic liquid, as long as the above condition can be satisfied. And a metal chelate, and a polyalkoxysiloxane or a precursor thereof.

  The definitions of the onium salt and the ionic liquid that are preferably contained in the coating composition for layer A are as described above.

  Specific examples of ionic liquid products include AS100, AS200, AS300, AS400 of Nippon Emulsifier Co., Ltd., IL-P series, IL-A series, IL-C series, IL-IM series of Koei Chemical Co., Ltd. , IL-AP series, and the like.

  Furthermore, the ionic liquid used in the present invention may have a reactive site, and examples of the ionic liquid having a reactive site include Nippon Emulsifier Co., Ltd. JI62J01, JI62G01, Koei Chemical Co., Ltd.'s IL-. MA series, IL-S series, FC-4400 of 3M Japan Co., etc. are mentioned.

  The amount of the ionic liquid contained in the coating composition for layer A is preferably 0.1 to 30% by mass, more preferably 1 to 25% by mass, and further preferably 3 to 20% by mass. When the amount of the ionic liquid is less than 0.1% by mass, the antistatic property may be insufficient, and when the amount of the ionic liquid exceeds 30% by mass, the ionic liquid is deposited on the surface of the laminate. There is.

  The definitions of the polyalkoxysiloxane and the alkoxysilane which are preferably contained in the coating composition A for layer A are as described above. The polyalkoxysiloxane precursor refers to the above-mentioned alkoxysilane monomer, a hydrolysis product of alkoxysilane, or a hydrolysis condensation product of alkoxysilane.

  From the viewpoint of reactivity of the coating composition A for layer A, an oligomer and a monomer may be used in combination, and the amount of the monomer contained in the coating composition is preferably 0 to 50% by mass, more preferably 0 to 30% by mass. ..

  The definition of the metal chelate that is preferably contained in the coating composition for layer A is as described above.

Specific examples of metal chelate products include AL-3001, AL-3100, TC-401, TC-750, ZC-150, ZC-700 of Matsumoto Fine Chemical Co., Ltd., Acetope Al of Hope Pharmaceutical Co., Ltd., Acetope Fe, aluminum chelate A, Kawaken Fine Chemical Co., Ltd., aluminum chelate D, ALCH, AIPD, PADM and the like can be mentioned.

  The amount of the metal chelate contained in the coating composition for layer A is preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass, and further preferably 3 to 15% by mass. If the amount of the metal chelate is less than 0.1% by mass, the curing reaction of the layer A may not proceed rapidly, and it may be necessary to reduce the coating speed. Further, when the layer B is formed on the layer A, curing inhibition of the layer B may occur and the peeling force may decrease. If the amount of the compound having a metal element exceeds 30% by mass, the stability of the coating composition with time may deteriorate and the coating quality may deteriorate.

  The solid content concentration of the coating composition for layer A in the present invention is not particularly limited to this, but when the coating composition for layer A contains a solvent, it is generally preferably 20% by mass or less, and more preferably 0.5 to. It is preferably 10% by mass. When the solid content concentration is less than 0.5% by mass, cissing may be likely to occur on the base film, and when the solid content concentration exceeds 20% by mass, the viscosity becomes high, and thus the quality is deteriorated. There is.

[Layer B]
In the laminate of the present invention, an oligomer block property that suppresses the surface migration of low molecular weight components from the supporting base material, solvent resistance adhesion to layer B and the supporting base material, and an adhesive layer formed on layer B of the laminated body. Then, from the viewpoint of antistatic properties of both the adhesive layer and the laminate when the adhesive layer is peeled off, one or more layers A are provided on the supporting substrate, and then a layer B containing polydimethylsiloxane is provided. Preferably.

  The polydimethylsiloxane contained in the layer B can be confirmed by performing elemental analysis on the surface of the layer B. Specifically, the surface of the layer B is subjected to elemental analysis by using various composition/elemental analyzers (FT-IR, XPS, XRF, EDAX, SIMS, EPMA, EELS, etc.), and a Si element derived from polydimethylsiloxane. It can be confirmed by the presence or absence of peak detection.

  The method for forming the layer B is not particularly limited as long as the layer B containing polydimethylsiloxane can be formed, but it is preferable that a layer of the resin composition for the layer B described below can be formed on the layer A, and the resin precursor for the layer B can be formed. It is preferable that the coating composition for layer B containing a body is applied and dried by the method for forming a laminate described below.

  For example, when the layer B is formed by coating, the dry coating thickness of the layer B is preferably 10 to 500 nm, more preferably 20 to 200 nm. By setting the dry coating thickness of the layer B within the above range, it is possible to realize the basic function and additional function as a stable release film, which is unlikely to lower the productivity.

[Resin composition for layer B]
The resin composition for layer B in the present invention preferably contains polydimethylsiloxane from the viewpoint of releasability, more preferably a silicone resin, and particularly preferably a curable silicone resin.

  The curable silicone resin includes an organohydrogenpolyroxane and an alkenyl group-containing organopolysiloxane which are heat-cured under a platinum catalyst in an "addition reaction type" organohydrogenpolyroxane "Polycondensation reaction type" in which an organopolysiloxane containing a hydroxyl group is heat-cured using an organotin catalyst, an organopolysiloxane containing an alkenyl group and an organopolysiloxane containing a mercapto group are used as a photopolymerization catalyst. There is a "radical addition type" in which it is used for curing and a "cationic polymerization type" in which an epoxy group is photo-opened and cured with an onium salt initiator. Either may be used, but from the viewpoint of productivity and peeling force. An addition reaction type in which an organohydrogenpolyroxane and an alkenyl group-containing organopolysiloxane are heated and cured under a platinum catalyst is preferable.

  The resin composition for layer B in the present invention can be preferably formed by removing the solvent in a drying step, if necessary, and then curing the coating composition for layer B described below.

[Layer B coating composition, layer B resin precursor]
The above-mentioned coating composition for layer B is a mixture showing a liquid state at room temperature capable of forming the above-mentioned layer B or the above-mentioned resin composition for layer B, and a laminate having at least layer B described below. A material capable of forming a resin composition for layer B (hereinafter referred to as a resin precursor), a polymerization initiator, a curing agent, a curing catalyst, and a solvent, particles, an antistatic agent, etc. Various additives may be included.

  The composition of the coating composition for the layer B is not particularly limited as long as the layer B contains polydimethylsiloxane. However, as described above, from the viewpoint of mold releasability and heat resistance, a silicone resin, particularly a curable silicone resin is used. A resin precursor capable of forming a resin precursor is preferable, and an "addition reaction type", "polycondensation reaction type", "radical addition type", "cationic polymerization type" resin precursor, and a polymerization initiator, a curing agent, and a curing catalyst are used. The coating composition containing it is more preferable, and the "addition reaction type" is the most preferable.

  As specific examples of the addition reaction type silicone resin precursor and the catalyst, those containing polydimethylsiloxane having a vinyl group at the terminal and hydrogen siloxane are preferable, and KS-3650 manufactured by Shin-Etsu Chemical Co., Ltd., KS843, KS847, KS847H, KS847T, X62-2829, KS838, Toray Dow Corning Co., Ltd. SD7333, SRX357, SRX345, LTC310, LTC303E, LTC300B, LTC75T, C755T, C75T, LTC751, LTC75T, LTC751, LTC75L, LTC751, LTC75L, LTC751, LTC75L, LTC751, LTC75L, LTC751, LTC75L, LTC751. And so on.

  As specific examples of the condensation polymerization reaction type silicone resin precursor and the catalyst, those containing an organic tin catalyst of polydimethylsiloxane having a hydroxyl group at the end and hydrogensiloxane are preferable, and SRX290 manufactured by Toray Dow Corning Co., Ltd. And SY LOFF23.

  As specific examples of the radical addition type silicone resin precursor and the catalyst, those containing a siloxane containing an alkenyl group, a siloxane containing a mercapto group and a photopolymerization catalyst are preferable, and BY24-510H manufactured by Toray Dow Corning Co., Ltd. and BY24-544 etc. are mentioned.

  As specific examples of the cationic polymerization type silicone resin precursor and the catalyst, those containing an epoxy group-containing siloxane and an onium salt initiator are preferable, and TPR6501, UV9300 and XS56- manufactured by Momentive Performance Materials Japan LLC. A2775 etc. are mentioned.

  The solid content concentration of the coating composition for layer B in the present invention is not particularly limited, but when the coating composition for layer B contains a solvent, it is usually 10% by mass or less, and further 0.5 to 5% by mass. % Is preferable. When the solid content concentration of the coating composition is less than 0.5% by mass, cissing may be likely to occur on the supporting substrate or the above-mentioned layer A, and the solid content concentration of the coating composition is 10% by mass. If it exceeds, the surface may become rough.

[Other paint composition additives]
The above-mentioned coating composition for layer A and coating composition for layer B may contain a solvent, and preferably contains a solvent from the viewpoint of production suitability. Here, the solvent refers to a substance that is a liquid at room temperature and atmospheric pressure that can evaporate almost the entire amount in the drying step after coating. The coating composition suitable for the laminate of the present invention may contain a solvent. The number of kinds of solvent is preferably 1 or more and 20 or less, more preferably 1 or more and 10 or less, and further preferably 1 or more and 6 or less.

  The type of solvent depends on the molecular structure of the solvent. That is, those having the same elemental composition but different bond relationships even if the type and number of functional groups are the same (structural isomers). Those that do not overlap (stereoisomers) are treated as different kinds of solvents. For example, 2-propanol and n-propanol are treated as different solvents.

[Supporting substrate]
Examples of the supporting substrate in the present invention include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene films, polypropylene films, polyvinyl chloride films, polyvinylidene chloride films, polyvinyl alcohol films, ethylene-vinyl acetate. Copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyetheretherketone film, polyethersulfone film, polyphenylene sulfide film, polyetherimide film, polyimide film, fluororesin film, polyamide film, acrylic A resin film, a norbornene-based resin film, a cycloolefin resin film and the like can be mentioned, and as a supporting base material that is preferably used particularly when used as a release film, mechanical strength, heat resistance, thermal dimensional stability and A biaxially stretched polyester film having excellent chemical resistance and economical is preferable.

  The surface of the supporting substrate may be subjected to various surface treatments before forming the layer A. Examples of the surface treatment include chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high frequency treatment, glow discharge treatment, active plasma treatment, laser treatment, mixed acid treatment and ozone oxidation treatment. Among these, glow discharge treatment, ultraviolet irradiation treatment, corona discharge treatment and flame treatment are preferable, and glow discharge treatment and ultraviolet treatment are more preferable.

[Method of manufacturing laminated body]
The laminate of the present invention is preferably formed by coating the coating composition for layer A on a supporting substrate and further coating the coating composition for layer B.

  The method for applying the coating composition onto the supporting substrate is not particularly limited, but the coating composition may be applied by a dip coating method, a roller coating method, a wire bar coating method, a gravure coating method or a die coating method (US Pat. No. 2,681,294). It is preferable that the layer is formed by applying it to a supporting base material or the like by the method described above. Further, among these coating methods, the gravure coating method or the die coating method is more preferable as the coating method. Next, the liquid film applied on the supporting substrate or the like is dried. In addition to completely removing the solvent from the obtained laminate, it is preferable to heat the liquid film in the drying step also from the viewpoint of accelerating the curing of the coating film.

  Examples of the drying method include heat transfer drying (adhesion to a hot object), convective heat transfer (hot air), radiant heat transfer (infrared), and others (microwave, induction heating). Among these, in the manufacturing method of the present invention, a method using convective heat transfer or radiant heat transfer is preferable because it is necessary to precisely make the drying rate uniform in the width direction.

  Furthermore, you may perform the further hardening operation (hardening process) by irradiating heat or an energy ray. In the curing step, when curing with heat, the temperature is preferably from room temperature to 200° C. or less, more preferably 100° C. or more and 200° C. or less, and further preferably 130° C. or more 200 from the viewpoint of activation energy of the curing reaction. It is below ℃.

Further, in the case of curing with energy rays, from the viewpoint of versatility, electron rays (EB rays) and/or ultraviolet rays (UV rays) are preferable. Moreover, examples of the type of ultraviolet lamp used when irradiating with ultraviolet rays include a discharge lamp system, a flash system, a laser system, and an electrodeless lamp system. When ultraviolet curing is performed using a high pressure mercury lamp that is a discharge lamp system, the illuminance of ultraviolet rays is 100 to 3,000 mW/cm ² , preferably 200 to 2,000 mW/cm ² , and more preferably 300 to 1,000 mW/cm ^2. performing the ultraviolet irradiation is preferred, the accumulated light quantity of ultraviolet 100~3,000mJ / cm ^2, preferably 200~2,000mJ / cm ^2, more preferably a 300~1,500mJ / cm ² under the condition that the It is more preferable to perform ultraviolet irradiation under the conditions. Here, the ultraviolet illuminance is the irradiation intensity received per unit area, and changes depending on the lamp output, the emission spectrum efficiency, the diameter of the emission bulb, the design of the reflecting mirror, and the light source distance from the irradiation target. However, the illuminance does not change depending on the transport speed. Further, the integrated light amount of ultraviolet rays is irradiation energy received per unit area, and is the total amount of photons reaching the surface. The integrated light quantity is inversely proportional to the irradiation speed passing under the light source, and is proportional to the number of times of irradiation and the number of lamps.

[Use]
Further, the laminate of the present invention can be preferably used as a release film, and can be particularly preferably used as a release film for protecting an adhesive layer of a polarizing plate or a retardation film.

  Next, the present invention will be described based on examples, but the present invention is not necessarily limited to these. The same product was used for the same compound unless otherwise specified.

[Creation of supporting substrate]
[Supporting substrate 1]
The composition is as shown in Table 1, and the raw material was supplied to a vent co-directional twin-screw extruder having an oxygen concentration of 0.2% by volume, melted at a layer A extruder cylinder temperature of 280° C., and a short tube temperature of 275. C., the die temperature was 280.degree. C., and a sheet was discharged from a T die onto a cooling drum whose temperature was controlled at 25.degree. At that time, static electricity was applied using a wire electrode having a diameter of 0.1 mm, and the electrode was brought into close contact with the cooling drum to obtain an unstretched sheet. Then, the film was preheated in the longitudinal direction at a preheating temperature of 85° C. for 1.5 seconds, stretched 3.3 times in the longitudinal direction at a stretching temperature of 115° C., and immediately cooled with a metal roll whose temperature was controlled at 40° C. Then, it is preheated at a preheating temperature of 85° C. for 1.5 seconds with a tenter type transverse stretching machine, and is stretched 3.3 times in the width direction at the former half temperature of stretching 115° C., the middle stage temperature of stretching 135° C. and the latter half temperature of stretching 145° C., as it is. A heat treatment was performed in a tenter at a heat treatment temperature of 230° C. while applying 5% relaxation in the width direction to obtain a biaxially oriented polyester film having a film thickness of 23 μm. This was used as a supporting substrate 1.

[Preparation of coating composition]
[Preparation of coating composition a1 to a29 for layer A]
The coating compositions a1 to a29 for layer A were obtained by mixing the materials shown in Table 2 in proportions. The details of each raw material in Table 2 are as follows.

[Preparation of coating composition a30 to a53 for layer A]
The coating compositions a30 to a53 for layer A were obtained by mixing with the materials shown in Table 5 in a ratio. The details of each raw material in Table 5 are as follows.

[Alkoxysilane]
A1:3 Methacryloxypropyl trimethoxy silane (KBM-503 Shin-Etsu Chemical Co., Ltd.)
A2:3 glycidoxypropyltrimethoxysilane (KBM-403 Shin-Etsu Chemical Co., Ltd.)
A3: Tetraethoxysilane (KBE04 Shin-Etsu Chemical Co., Ltd.)
A4: Silane oligomer (KR500 Shin-Etsu Chemical Co., Ltd.)
A5: Silane oligomer (methyl silicate 53A Colcoat Co., Ltd.)
A6: Silane oligomer (Ethyl silicate 48 Colcoat Co., Ltd.)
A7: Silane oligomer (HAS-6 Colcoat Co., Ltd.)
A8: Phenyltriethoxysilane (KBE103 Shin-Etsu Chemical Co., Ltd.).

[Onium salt]
B1: Ionic liquid (Aminoion ^R AS100 Nippon Emulsifier Co., Ltd.)
B2: Ionic liquid (KOELIQ ^™ IL-AP3 Koei Chemical Industry Co., Ltd.)
B3: Ionic liquid (KOELIQ ^™ IL-A2 Koei Chemical Industry Co., Ltd.)
B4: Ionic liquid (KOELIQ ^™ IL-P14, Koei Chemical Industry Co., Ltd.)
B5: Ionic liquid (KOELIQ ^™ IL-IM1 Koei Chemical Industry Co., Ltd.)
B6: Acrylic group-containing ionic liquid (amino ion ^R AS series JI62J01 Nippon Emulsifier Co., Ltd.)
B7: An ionic liquid having an alkoxysilyl group (Amino ion ^R AS series JI62G02 Nippon Emulsifier Co., Ltd.).

[Metal chelate compound]
C1: Aluminum trisacetylacetonate (AL-3100 Matsumoto Fine Chemical Co., Ltd.)
C2: Aluminum isopropylate (AIPD Kawaken Fine Chemicals Co., Ltd.)
C3: Titanium acetylacetonate (TC-100 Matsumoto Fine Chemical Co., Ltd.)
C4: Zirconium tetraacetylacetonate (ZC-150 Matsumoto Fine Chemical Co., Ltd.)
C5: Iron acetylacetonate (acetop Fe Hope Pharmaceutical Co., Ltd.)

[Other additives]
D1: Photopolymerization initiator (Irgacure 184 BASF Japan Ltd.).

[solvent]
E1: Isopropyl alcohol E2: Methyl ethyl ketone.

[Preparation of Coating Compositions b1 to b3 for Layer B]
[Layer B coating composition b1] The following materials were mixed to obtain Layer B coating composition b1.
Toluene solution of methylvinylpolysiloxane and methylhydrogenated polysiloxane: 10 parts by mass (KS847H manufactured by Shin-Etsu Chemical Co., Ltd., solid content concentration 30% by mass)
-Methyl vinyl polysiloxane and platinum complex solution: 0.1 part by mass (PL-50T manufactured by Shin-Etsu Chemical Co., Ltd.)
-Toluene: 10 parts by mass-Heptane: 10 parts by mass.

[Layer B coating composition b2] The following materials were mixed to obtain Layer B coating composition b2.
Toluene solution of methylhexylene polysiloxane and methylhydrogenated polysiloxane: 10 parts by mass (LTC750A manufactured by Toray Dow Corning Co., Ltd., solid content concentration 30% by mass)
・Methyl vinyl polysiloxane and platinum complex solution: 0.1 part by mass (SRX212 manufactured by Toray Dow Corning Co., Ltd.)
-Toluene: 10 parts by mass-Heptane: 10 parts by mass.

[Layer B coating composition b3] The following materials were mixed to obtain Layer B coating composition b3.
Toluene solution of methylvinylpolysiloxane and methylhydrogenated polysiloxane: 10 parts by mass (KS847H manufactured by Shin-Etsu Chemical Co., Ltd., solid content concentration 30% by mass)
-Methyl vinyl polysiloxane and platinum complex solution: 0.1 part by mass (PL-50T manufactured by Shin-Etsu Chemical Co., Ltd.)
Ionic liquid: 0.088 parts by mass (Amino ion ^R AS100 manufactured by Nippon Emulsifier Co., Ltd.)
-Toluene: 10 parts by mass-Heptane: 10 parts by mass.

[Creation of laminated body, preparation of layer B]
A laminate and a layer B were obtained in accordance with the following production-c1 to c9 of layered body and production-c10 of layer B.

[Creation of laminated body-c1]
A coating film composition for layer A was applied to a 38 μm thick polyester film (trade name “Lumirror” (registered trademark) R60 manufactured by Toray Industries, Inc.) with a gravure coater so that the coating thickness after drying and curing was 50 nm. It was dried and cured at 80° C. for 3 seconds.

  Then, within 3 minutes, the coating composition for layer B was applied by gravure coating so that the coating thickness after drying was 80 nm, and dried and cured at 120° C. for 30 seconds to obtain a laminate.

[Creation of laminated body-c2]
A coating film composition for layer A was applied to a 38 μm thick polyester film (trade name “Lumirror” (registered trademark) R60 manufactured by Toray Industries, Inc.) with a gravure coater so that the coating thickness after drying and curing was 50 nm. It was dried and cured at 80° C. for 3 seconds.

Then, within 3 minutes, the coating composition for layer B was applied by gravure coating so that the coating thickness after drying was 80 nm, dried and cured at 120° C. for 30 seconds, and then 100 mJ/cm ² with a high pressure mercury lamp. Was irradiated with ultraviolet rays to obtain a laminate.

[Creation of laminated body-c3]
A laminate was obtained in the same manner as in the above-mentioned preparation of laminate-c1, except that the coating composition for layer A was applied by a gravure coater so that the coating thickness after drying and curing was 80 nm.

[Creation of laminated body-c4]
A laminate was obtained in the same manner as in the above-mentioned preparation of laminate-c1, except that the coating composition for layer A was applied by a gravure coater so that the coating thickness after drying and curing was 120 nm.

[Creation of laminated body-c5]
A laminate was obtained in the same manner as in the preparation of the laminate-c1 except that the coating composition for layer A was applied by a gravure coater so that the coating thickness after drying and curing was 15 nm.

[Creation of laminated body-c6]
A laminate was obtained in the same manner as in the above-mentioned preparation of laminate-c1 except that the coating composition for layer B was applied by a gravure coater so that the coating thickness after drying and curing was 50 nm.

[Creation of laminated body-c7]
A laminate was obtained in the same manner as in the preparation of the laminate-c1 except that the coating composition for layer B was applied by a gravure coater so that the coating thickness after drying and curing was 150 nm.

[Creation of laminated body-c8]
A laminate was obtained in the same manner as in the preparation of the laminate-c1 except that the coating composition for layer B was applied by a gravure coater so that the coating thickness after drying and curing was 30 nm.

[Creation of laminated body-c9]
The coating composition for layer A was applied to a 23 μm-thick polyester film (supporting substrate 1) with a gravure coater so that the coating thickness after drying and curing was 50 nm, and was dried and cured at 80° C. for 3 seconds.

  Then, within 3 minutes, the coating composition for layer B was applied by gravure coating so that the coating thickness after drying was 80 nm, and dried and cured at 120° C. for 30 seconds to obtain a laminate.

[Creation of layer B-c10]
The coating composition for layer B was applied to a 38 μm-thick polyester film (trade name “Lumirror” (registered trademark) R60 manufactured by Toray Industries, Inc.) by gravure coating so that the coating thickness after drying was 80 nm. It was dried and cured at 30° C. for 30 seconds to obtain Layer B.

  By the above method, the laminates of Examples 1 to 35 and Examples 36 to 65, the laminates of Comparative Examples 1 to 3, the layer B of Comparative Example 4, the layer B of Comparative Example 5, and the laminates of Comparative Examples 6 to 8. It was created. The coating compositions of layers A and B of Examples 1 to 35 and Comparative Examples 1 to 4, thicknesses of Layer A and Layer B, and manufacturing methods are shown in Table 3, and layers of Examples 36 to 65 and Comparative Examples 5 to 8 are shown. Table 6 shows the coating compositions of A and layer B, the thicknesses of layer A and layer B, and the manufacturing method.

[Evaluation of laminate]
The performance evaluations shown below were performed on the produced laminate, and the obtained results are shown in Tables 4 and 7. Unless otherwise specified, in each of the examples and comparative examples, the measurement was performed three times by changing the location for one sample, and the average value was used.

[Concentration of onium salt (region X, region Y, region Z)]
Regarding the concentration of the onium salt, the cross section (HAADF-STEM image) of the laminate obtained by using a field emission transmission electron microscope (JEM-2100F manufactured by JEOL) was subjected to EELS analysis (elemental analysis) of each region, The concentration of onium salt was calculated.

Specifically, an ultrathin film section of the laminated body is prepared using the RuO ₄ dyeing ultrathin section method, and is observed at a magnification of 200,000 using a field emission transmission electron microscope (JEM-2100F manufactured by JEOL). EELS analysis (elemental analysis) of each region was performed on the cross section (HAADF-STEM image).

In the RuO ₄ dyeing ultrathin section method, the cross section of the laminate is dyed with RuO ₄ dye, and after immobilization with the embedding resin, an ultrathin film slice of the cross section of the laminate is prepared using a freezing microtome. When the obtained ultrathin film section is observed using a field emission transmission electron microscope, the layer B is dyed and the layer A is not dyed. Therefore, the interface between the layer B and the layer A is observed due to the contrast difference.

Then, EELS analysis (elemental analysis) is performed on the following regions from the cross-sectional image of the obtained laminated body to obtain the element peak (atm%) ratio of each region. The obtained element peak ratio was calculated as the concentration ratio of each element, and the concentration of the characteristic element contained in the onium salt was defined as the concentration of the onium salt.
Region X: region of the outermost surface of layer B in the thickness direction In the cross-sectional image of the laminate observed using the above method, from the point α (identified from the contrast difference between the embedding resin and the layer B), 5 nm in the thickness direction. EELS analysis was performed using the point as the center point of the measurement, and the intensity ratio of the obtained different element peaks was calculated as the concentration ratio, and the concentration of the characteristic element contained in the onium salt was compared with the concentration of the onium salt in the region X. did.
Area Y: Area in the central part of layer B In the cross-sectional image of the laminate observed using the above method, point β (layer B is identified from the contrast difference, and the middle point of layer B is determined from the film thickness of layer B). EELS analysis is performed on the range other than the region X and the region Z in the thickness direction including the calculation). Since the region Y is wider than the regions X and Z, the elemental analysis is performed for each range of 10 nm in the direction of the supporting substrate from the point of 5 nm in the direction of the supporting substrate from the interface between the regions X and Y. The intensity ratio of the obtained different element peaks was calculated as the concentration ratio, and the concentration of the characteristic element contained in the onium salt was calculated as the concentration of the onium salt. The one having the highest onium salt concentration in the region Y was defined as the concentration of the onium salt in the region Y.
Area Z: Area of interface between layer A and layer B In the cross-sectional image of the laminate observed using the above method, the point γ (identified from the contrast difference between layer A and layer B) is included, and the point γ is measured. EELS analysis was performed using the center point, the intensity ratio of the obtained different element peaks was calculated as the concentration ratio, and the concentration of the characteristic element contained in the onium salt was defined as the concentration of the onium salt in the region Z.

[Concentration of onium salt (region V, region S, region T, region W)]
The concentration of the onium salt was calculated in the same manner as the method described above in [Concentration of onium salt (region X, region Y, region Z)].
Region V: region of the outermost surface of layer B in the thickness direction In the cross-sectional image of the laminate observed using the above method, from the point ε (identified from the contrast difference between the embedding resin and the layer B), 5 nm in the thickness direction. EELS analysis was performed with the point as the center point of the measurement, and the intensity ratio of the obtained different element peaks was calculated as the concentration ratio. The concentration of the characteristic element contained in the onium salt was compared with the concentration of the onium salt in the region V. did.
Region S: central region of layer B In the cross-sectional image of the laminate observed using the above method, point σ (layer B is identified from the contrast difference, and the middle point of layer B is determined from the film thickness of layer B). EELS analysis is performed using the point σ as the center point of measurement, and the intensity ratio of the obtained different element peaks is calculated as the concentration ratio, and the concentration of the characteristic element contained in the onium salt is The concentration of the onium salt of
Area T: Area in the central part of layer A In the cross-sectional image of the laminate observed using the above method, point ω (layer A is identified from the contrast difference, and the midpoint of layer A is determined from the film thickness of layer A). EELS analysis using the point ω as the center point of the measurement, and calculating the intensity ratio of the obtained different element peaks as the concentration ratio, the concentration of the characteristic element contained in the onium salt is The concentration of the onium salt of
Area W: Area of Interface between Layer A and Support Base Material In the cross-sectional image of the laminate observed using the above method, 5 nm in the direction of Layer A from point η (identified from the contrast difference between Layer A and the support base material). EELS analysis is performed with the point of the center of the measurement as the center point of the measurement, and the intensity ratio of the obtained different element peaks is calculated as the concentration ratio. And

[Peeling power (normal temperature)]
An adhesive tape (manufactured by Nitto Denko Corporation, polyester tape, trade name 31B: hereinafter 31B tape) was pressure-bonded to the layer B-forming surface of the laminate by reciprocating a 5 kgf rubber roller once, and left at 20° C. 65% RH for 24 hours Using a tensile tester, the stress when peeling 180° at a speed of 300 mm/min was measured. A peeling force of 0.13 mN or less was accepted.

[Solvent resistance]
Using a Gakushin-type friction tester type II manufactured by Tester Sangyo Co., Ltd., a layer of the laminated body was rubbed with a cotton cloth (gold width No. 3) impregnated with about 1 ml of toluene with a load of 200 gf×30 reciprocating, and laminated on the surface of the laminated body. After the solvent attached to was dried, a polyester adhesive tape (No. 31B tape manufactured by Nitto Denko Corporation, 18 mm width) was attached while being pressed with a 5 kgf roller, left for 1 hour, and peeled off with a tensile tester. The load was measured when the tape was peeled off at a peeling angle of 180° at 300 mm/min. This peeling force was taken as the peeling force of the layer B forming surface after rubbing with a toluene-impregnated cotton cloth.

  A polyester adhesive tape (No. 31B tape manufactured by Nitto Denko Corporation, 18 mm width) was attached to the layer B forming surface of a laminate different from the sample used for the above measurement while press-bonding with a 5 kgf roller. The tape was allowed to stand for a period of time and the load when the tape was peeled off at a peeling speed of 300 mm/min and a peeling angle of 180° was measured with a tensile tester, and this peeling force was taken as the initial peeling force of the layer B-formed surface.

The solvent resistance adhesion was calculated by applying this result to the following formula. A solvent resistance adhesion of 85% or more was regarded as acceptable.
Resistance to solvent adhesion = A/B x 100
A: Initial peeling force of the layer B forming surface B: Peeling force of the layer B forming surface after rubbing with a toluene-impregnated cotton cloth.

[Solvent resistance 2]
Using a Gakushin-type friction tester type II, manufactured by Tester Sangyo Co., Ltd., a layer of a layer B of the laminate was rubbed with a cotton cloth (gold width 3) impregnated with about 1 ml of ethyl acetate under a load of 200 gf×30 reciprocating, and laminated. Dry the solvent on your body. Then, in a 23° C.×65% RH environment, using a surface resistance measuring device (Mitsubishi Chemical Corporation Hirestor UX detection upper limit value 9×10 ¹⁴ Ω/□), the layer B surface of the laminated body after rubbing was measured. Arbitrary 3 points were measured. The average value was taken as the surface resistance value after rubbing with ethyl acetate, and a value of 9×10 ¹² Ω/□ or less was regarded as acceptable.

[Antistatic property 1... initial surface resistance value and surface resistance value after peeling the adhesive layer]
Under a 23° C.×65% RH environment, using a surface resistance measuring device (Mitsubishi Chemical Corporation Hirestor UX detection upper limit value 9×10 ¹⁴ Ω/□), any three points on the surface of layer B of the laminated body Was measured. The average value was used as the initial surface resistance value, and 9×10 ¹² Ω/□ or less was regarded as a pass.

[Antistatic property 2... Amount of charge of adhesive layer and laminate after peeling]
On the layer B of the laminated body, an acrylic pressure-sensitive adhesive (Olivine BPS-8170 manufactured by Toyochem Co., Ltd.) was applied using a wire bar (No. 40), and the pressure-sensitive adhesive was dried in an oven at 150° C. for 2 minutes. , An adhesive layer was formed. Then, a 25 μm-thick polyester film was bonded onto the adhesive layer while being pressed by a 5 kg roller, and left in an atmosphere of room temperature of 23° C. and humidity of 65% RH for 1 hour.

  Then, the laminated body pressure-bonded through the polyester film and the adhesive layer was cut into A4 (210 mm×297 mm) size, and only the laminated body was peeled to obtain an adhesive layer after peeling and a laminated body after peeling. .. With respect to the adhesive layer after peeling and the laminated body after peeling, the potential was measured using a surface potential meter (MODEL 323 manufactured by Trek Japan KK), and 20.0 V or less was passed. The potential was measured in the lateral direction (210 mm) of A4, and the average value of the obtained potentials (absolute value) was calculated and used.

[Oligomer block property 1... Amount of oligomer]
The amount of oligomer was measured by the method described below.

After heat-treating the laminated body at 180° C. for 10 minutes, the laminated body was folded so that the area of the bottom side was 72 cm ² , and a square box was formed so that the inside was layer A and layer B. Then, 10 ml of N,N-dimethylformamide (DMF) was placed in the box of the laminated body prepared here so that the entire bottom area was soaked in DMF and allowed to stand for 3 minutes, then DMF was recovered and subjected to liquid chromatography. It was supplied to a graph (Shimadzu CLASS-VP) and the amount of polyester oligomer in DMF was determined. The amount of polyester oligomer in DMF was divided by the area of the layered product which was brought into contact to obtain the amount of oligomer (mg/m ² ), and the amount of oligomer of 0.1 (mg/m ² ) or less was passed.

The amount of oligomer in DMF was determined from the peak area ratio of the standard sample peak area and the measurement sample peak area. As a standard sample, a polyester oligomer (cyclic trimer) preliminarily collected was accurately weighed, and at the same time, it could be dissolved in accurately weighed DMF. The concentration of the standard sample was 0.001 to 0.01 (mg/m ² ).

The conditions for measuring the amount of polyester oligomer in DMF by liquid chromatography are as follows.
Mobile phase A: Methanol Mobile phase B: Pure water column: YMC-Pack OSD-A
Column temperature: 40°C
Detection wavelength: 240 nm.

[Oligomer block property 2... Number of foreign matter defects]
The number of foreign matter defects was measured by the glass plate inspection method shown below.
After confirming that there is not enough foreign matter on the layer B of the laminate, an acrylic pressure-sensitive adhesive (Olivine BPS-8170 manufactured by Toyochem Co., Ltd.) is applied using a wire bar (No. 40) and the temperature is 150°C. The adhesive was dried in the oven for 2 minutes to form an adhesive layer. Then, a 25 μm-thick polyester film was bonded onto the adhesive layer while being pressed by a 5 kg roller, and left in an atmosphere of room temperature of 23° C. and humidity of 65% RH for 1 hour.

  After that, the laminated body pressure-bonded with the polyester film via the adhesive layer is cut into 50 mm×100 mm, only the laminated body is peeled off, and the polyester film with the adhesive layer is adhered to a smooth and transparent glass plate having a thickness of 5 mm. The layers were attached while being pressed against each other with a 5 kg roller.

Both sides of the glass plate/adhesive layer/polyester film laminate were visually observed under a standard light source, and the number of foreign matter defects such as bright spots having a circumscribed diameter of 30 μm or more and fogging was counted. The size of the defects was observed with a microscope. The number of foreign matter defects was judged according to the following judgment criteria, and two or more points were judged to be acceptable.
3 points: Foreign matter defect number = 0/50 cm ²
2 points: Number of foreign matter defects=1 to 2/50 cm ²
1 point: Foreign matter defect number=3 or more/50 cm ² .

1 Supporting substrate 2 Layer A
3rd layer B
4 Reference line perpendicular to the supporting substrate 5 points α
6 points β
7 points γ
8 area X
9 area Y
10 Area Z
11 Supporting Substrate 12 Layer A
13th layer B
14 Reference line perpendicular to the supporting substrate 15 Point ε
16 points σ
17 points
18 points η
19 Area V
20 area S
21 Area T
22 Area W

  The laminate of the present invention can be suitably used for protecting polarizing plates and pressure-sensitive adhesive layers of retardation films.

Claims (5)

A release film having a layer A and a layer B on at least one surface of a supporting substrate in this order from the supporting substrate side, wherein the layer A contains an onium salt, and the layer B contains an onium salt and polydimethyl. Containing siloxane, the concentration of the onium salt in the outermost surface region of the layer B (region X) in the thickness direction, the central region of the layer B (region Y), and the region of the interface between the layers A and B (region Z) is A release film which satisfies the following formula (1) or (2).
Area X≧area Z>area Y... Formula (1)
Region Z> Region X> Region Y... Formula (2) A release film having a layer A and a layer B on at least one surface of a supporting substrate in this order from the supporting substrate side, wherein the layer A contains an onium salt, and the layer B contains an onium salt and polydimethyl. A region including the siloxane, which is the outermost surface of the layer B in the thickness direction (region V), the central region of the layer B (region S), the central region of the layer A (region T), the layer A and the supporting substrate. A release film, wherein the onium salt concentration in the interface region (region W) satisfies the following formula (3) or (4).
Region V≧region W>region S and region T... Formula (3)
Region W>region V>region S and region T... Formula (4) The release film according to claim 1, wherein the layer A contains a polyalkoxysiloxane and a metal chelate compound. The release film according to any one of claims 1 to 3, wherein the onium salt is an ionic liquid. The release film has a polyester oligomer amount of 0.1 mg/m ² or less by dimethylformamide extraction after heat treatment at 180° C. for 10 minutes, and a circumscribed diameter on the surface of the layer B of 30 μm or more by a glass plate inspection method. The release film according to any one of claims 1 to 4, wherein the number of defects of the size of foreign matter is 2/50 cm ² or less.