JP7087459B2 - Releasable laminate, transfer sheet, process sheet and article using it - Google Patents

Description

The present invention relates to a releasable laminate, and a transfer sheet, a process sheet, and an article using the same.

In recent years, as the miniaturization of electronic device parts has progressed, various electronic device parts are bonded and fixed on the film, and after the processes such as cutting and punching are completed, each part is peeled off from the film and used. The method of manufacturing parts is carried out. Such films are called "process films" and are mainly used in the production of ceramic green sheets.

As such a process film, for example, a film such as Patent Document 1 has been proposed.

Japanese Unexamined Patent Publication No. 2002-64131

In the process film of Patent Document 1, the adhesive layer formed on the film imparts initial adhesiveness, while after the process is completed, the adhesive layer is irradiated with ionizing radiation to cure the adhesive layer, reduce the adhesiveness, and further heat the film. By heat-shrinking the film, parts and the like can be easily peeled off from the adhesive layer.
However, the process film of Patent Document 1 requires irradiation and heating of ionizing radiation, which makes the process complicated and requires two facilities (ionizing radiation irradiation facility and heating facility), which is economical. not good.
In addition, a process film that allows parts and the like to be peeled off by irradiation with ionizing radiation or heating after the process is completed has also been proposed, but the need for ionizing radiation irradiation equipment or heating equipment is required. There is no change.

As described above, the conventional process film has a problem in work efficiency and the like when peeling off the parts and the like adhered to the film after the process is completed.
Further, not only the film for a process but also a member having a predetermined adhesive force with respect to an adhesive but easily peeling off has not been proposed.

The present invention has been made in view of such circumstances, and is a releasable laminate that has a predetermined adhesive force to a pressure-sensitive adhesive but can be easily peeled off, and a transfer sheet using the same. The subject is to provide process sheets and articles.

In order to solve the above problems, the present invention provides the following [1] to [4].
[1] A release laminate having a release layer on a transparent plastic film, wherein the release layer is located on the outermost surface of the laminate and satisfies the following conditions 1 and 2.
<Condition 1>
Prepare an adhesive tape A having a peel strength of PA (N / 10 mm) in Method 1 (180 ° peeling from a stainless steel test plate) of JIS Z0237: 2009. Adhesive tape A is attached to the surface of the releasable laminate on the release layer side, and the adhesive tape A conforms to Method 1 of JIS Z0237: 2009 except that the test plate is a releasable laminate instead of stainless steel. When the peel strength at the time of peeling is P1 (N / 10 mm), P1 / PA shows 0.75 or more.
<Condition 2>
Adhesive tape A is attached to the surface of the releasable laminate on the release layer side. Water is dropped with a dropper so that at least the area where the adhesive tape A is bonded and the area 1 cm outside the outer edge of the adhesive tape A are covered with water on the surface of the release layer on the release layer side. do. After 5 minutes have passed since the dripping of water was completed, the adhesive tape A was peeled off in accordance with Method 1 of JIS Z0237: 2009 except that the test plate was not stainless steel but a releasable laminate. When the intensity is P2 (N / 10 mm), P2 / PA is 0.2 or less.
[2] A transfer sheet having a transfer layer on the release layer of the releasable laminate according to the above [1].
[3] A process sheet having the release layer of the releasable laminate according to the above [1] on the outermost surface.
[4] An article in which the release layer of the releasable laminate according to the above [1] is arranged so as to face the surface.

According to the present invention, a releasable laminated body having a predetermined adhesive force with respect to a pressure-sensitive adhesive and capable of easily peeling off an adhesive by a simple process of dropping water, and a releasable laminate using the same are used. Transfer sheets, process sheets and articles can be provided.

It is sectional drawing which shows one Embodiment of the releasable laminated body of this invention. It is sectional drawing which shows the other embodiment of the releasable laminated body of this invention.

[Releasable laminate]
The releaseable laminate of the present invention is a laminate having a release layer on a transparent plastic film, and the release layer is located on the outermost surface of the laminate and satisfies the following conditions 1 and 2. It is a thing.
<Condition 1>
Prepare an adhesive tape A having a peel strength of PA (N / 10 mm) in Method 1 (180 ° peeling from a stainless steel test plate) of JIS Z0237: 2009. Adhesive tape A is attached to the surface of the releasable laminate on the release layer side, and the adhesive tape A conforms to Method 1 of JIS Z0237: 2009 except that the test plate is a releasable laminate instead of stainless steel. When the peel strength at the time of peeling is P1 (N / 10 mm), P1 / PA shows 0.75 or more.
<Condition 2>
Adhesive tape A is attached to the surface of the releasable laminate on the release layer side. Water is dropped with a dropper so that at least the area where the adhesive tape A is bonded and the area 1 cm outside the outer edge of the adhesive tape A are covered with water on the surface of the release layer on the release layer side. do. After 5 minutes have passed since the dripping of water was completed, the adhesive tape A was peeled off in accordance with Method 1 of JIS Z0237: 2009 except that the test plate was not stainless steel but a releasable laminate. When the intensity is P2 (N / 10 mm), P2 / PA is 0.2 or less.

1 and 2 are cross-sectional views showing an embodiment of the releasable laminate of the present invention.
The releasable laminate 100 of FIGS. 1 and 2 has a hard coat layer 20, a layer 30 containing an inorganic compound, and a releasable layer 40 on a transparent plastic film 10 in this order. Further, the releasable laminate 100 of FIG. 2 has a hard coat layer 20, a layer 30 containing an inorganic compound, and a releasable layer 40 on both sides of the transparent plastic film 10.
The releasable laminate of the present invention is not limited to the embodiments shown in FIGS. 1 and 2. For example, the transparent plastic film 10 and the release layer 40 may not have the layer 30 containing the inorganic compound and / or the hard coat layer 20. Further, the release layer 40 does not need to be formed on the entire surface of the transparent plastic film 10, and may be provided on at least a part of the transparent plastic film 10. Further, the releasable laminate may have other layers (not shown).

The releasable laminate of the present invention needs to satisfy the following condition 1.
<Condition 1>
Prepare an adhesive tape A having a peel strength of PA (N / 10 mm) in Method 1 (180 ° peeling from a stainless steel test plate) of JIS Z0237: 2009. Adhesive tape A is attached to the surface of the releasable laminate on the release layer side, and the adhesive tape A conforms to Method 1 of JIS Z0237: 2009 except that the test plate is a releasable laminate instead of stainless steel. When the peel strength at the time of peeling is P1 (N / 10 mm), P1 / PA shows 0.75 or more.

Satisfying condition 1 indicates that the adhesive tape is sufficiently adhered to the surface of the release layer on the release layer side.
Further, satisfying the condition 1 and the condition 2 described later indicates that the adhesive tape can be easily peeled off by a simple operation of dropping water while the adhesive tape is sufficiently adhered at the initial stage.

As the adhesive tape A used under the conditions 1 to 4, it is preferable that the adhesive tape A has a peel strength of 3 to 7 (N / 10 mm) in the method 1 (180 ° peeling from the stainless steel test plate) of JIS Z0237: 2009.
Examples of the pressure-sensitive adhesive of the pressure-sensitive adhesive tape A used under the conditions 1 to 4 include a rubber-based pressure-sensitive adhesive, an acrylic-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, and a silicone-based pressure-sensitive adhesive. Further, the base material of the adhesive tape A is preferably a film.

In order to easily satisfy the condition 1, the release layer should be formed from the material described later, the thickness of the release layer should be within the range described later, and the adhesion between the release layer and the layer in contact with the release layer should be determined. It is preferable to make it good.

The releasable laminate of the present invention needs to satisfy the following condition 2.
<Condition 2>
Adhesive tape A is attached to the surface of the releasable laminate on the release layer side. Water is dropped with a dropper so that at least the area where the adhesive tape A is bonded and the area 1 cm outside the outer edge of the adhesive tape A are covered with water on the surface of the release layer on the release layer side. do. After 5 minutes have passed since the dripping of water was completed, the adhesive tape A was peeled off in accordance with Method 1 of JIS Z0237: 2009 except that the test plate was not stainless steel but a releasable laminate. When the intensity is P2 (N / 10 mm), P2 / PA is 0.2 or less.

Satisfying condition 2 means that the peeling strength of an adhesive such as an adhesive tape is lowered by an extremely simple process of dropping water and waiting for a short time, and the adhesive such as an adhesive tape can be easily peeled off. Means.
In Condition 2 and conditions 3 and 4 described later, it is preferable that the water to be dropped is ion-exchanged water.

The releasable substrate of the transfer sheet is required to have good adhesiveness to the transfer layer formed on the releasable substrate, and after the transfer layer is transferred to the adherend, the transfer layer is used. Properties that can be easily peeled off are required.
Further, the process sheet is required to have a property of being able to bond and fix electronic parts or the like via an adhesive or the like, and is also required to have a property of being able to easily peel off the electronic parts or the like from the surface of the process sheet after the process is completed.
Further, in showcases, show windows and windows, a characteristic of fixing a display object such as an advertisement with an adhesive tape is required, and a characteristic of being able to easily peel off the adhesive tape when changing the display object is required.
Therefore, the releasable laminate of the present invention that satisfies the conditions 1 and 2 is useful as a releasable substrate for a transfer sheet and a process sheet. It is also useful to apply the releasable laminate of the present invention to showcases, show windows and the surfaces of windows.

In order to easily satisfy the condition 2, it is preferable that the release layer is formed from a material described later, and the thickness of the release layer is within the range described later.

It is preferable that the releasable laminate of the present invention further satisfies the following condition 3.
<Condition 3>
The surface of the release layer of the releasable laminate is rubbed 1000 times back and forth with a load of 500 g / cm ² using a 300-count cotton flannel cloth, and this is referred to as a friction laminate 1. The adhesive tape A is attached to the surface of the friction laminate 1 on the release layer side. Water is dropped with a dropper so that at least the area where the adhesive tape A is bonded and the area 1 cm outside the outer edge of the adhesive tape A on the surface of the friction laminate 1 on the release layer side are covered with water. .. After 5 minutes have passed since the dripping of water was completed, the peeling strength when the adhesive tape A was peeled off in accordance with Method 1 of JIS Z0237: 2009 except that the test plate was not stainless steel but a friction laminate 1. When P3 (N / 10 mm) is set, P3 / PA is 0.2 or less.

Condition 3 shows that the characteristics of Condition 2 are maintained even if the surface of the release layer is rubbed with a flannel cloth many times. In other words, satisfying the condition 3 means that the property that the adhesive strength of an adhesive such as an adhesive tape is lowered by dropping water can be maintained for a long period of time.

The releasable substrate of the transfer sheet and the process sheet are usually discarded after being used once. However, when the condition 3 is satisfied, the property of lowering the adhesive force of the adhesive is not lowered by friction, so that it is preferable in that the releasable base material of the transfer sheet and the process sheet can be used repeatedly.
In addition, the surface of showcases, show windows and windows is cleaned on a daily basis, but by satisfying condition 3, it is possible to maintain the property of reducing the adhesive strength of the adhesive even after repeated cleaning. Become. Therefore, it is preferable that the configuration in which the releasable laminate of the present invention is applied to the surface of the showcase, the show window, and the window can be made more useful by satisfying the condition 3.
In addition, in this specification, a "showcase" means a box body whose inside can be visually recognized in a normal state, and is a concept including a refrigerator and a freezer.

In order to easily satisfy the condition 3, it is preferable to increase the scratch resistance of the releaseable laminate surface (release layer surface).
Specifically, it is preferable to arrange a layer containing an inorganic compound between the transparent plastic film and the release layer. Further, the layer containing the inorganic compound preferably further contains a binder resin. Further, it is preferable to perform the treatment described later on the surface of the layer containing the inorganic compound.

It is preferable that the releasable laminate of the present invention further satisfies the following condition 4.
<Condition 4>
A friction laminate 2 is obtained by rubbing the surface of the release layer of the releasable laminate with a cotton 300-count flannel cloth at a load of 500 g / cm ² for 5000 reciprocations. The adhesive tape A is attached to the surface of the friction laminate 2 on the release layer side. Water is dropped with a dropper so that at least the area where the adhesive tape A is bonded and the area 1 cm outside the outer edge of the adhesive tape A on the surface of the friction laminate 2 on the release layer side are covered with water. .. After 5 minutes have passed since the dripping of water was completed, the peeling strength when the adhesive tape A was peeled off in accordance with Method 1 of JIS Z0237: 2009 except that the test plate was not stainless steel but a friction laminate 2. When P4 (N / 10 mm), P4 / PA is 0.2 or less.

<Transparent plastic film>
Transparent plastic films include polyester, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyether sulphon, polysulphon, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone. , Polymethyl methacrylate, polycarbonate, polyurethane and resins such as Cyclo-Olfin-Polymer (COP).
Among these transparent plastic films, a stretched polyester film, particularly a biaxially stretched polyester film, is preferable from the viewpoint of mechanical strength and dimensional stability. Among the polyester films, polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are preferable.

The thickness of the transparent plastic film is preferably 5 to 500 μm, more preferably 10 to 200 μm.
Further, the transparent plastic film preferably has a total light transmittance of JIS K7361-1: 1997 of 80% or more, more preferably 90% or more, and further preferably 95% or more.

The transparent plastic film is subjected to easy-adhesion treatment such as physical or chemical surface treatment such as oxidation method or unevenness method on one side or both sides from the viewpoint of improving the adhesion to the layer formed on the film. May be. From the same viewpoint, it is also preferable to form an easy-adhesion layer on the transparent plastic film.

<Layer containing inorganic compounds>
The releasable laminate preferably has a layer containing an inorganic compound between the transparent plastic film and the releasable layer. With this configuration, the adhesion between the transparent plastic film and the release layer becomes good. Conditions 1 to 4 can be easily satisfied.

The layer containing an inorganic compound can be roughly classified into a layer formed by a wet method and a layer formed by a dry method.
Examples of the wet method include a method of forming by a sol-gel method using a metal alkoxide or the like, and a method of applying a coating liquid containing inorganic particles to a binder resin composition to form the binder resin composition.
Examples of the dry method include a physical vapor deposition method or a chemical vapor deposition method using inorganic particles as a raw material.
The wet method is excellent in terms of production efficiency. Further, the layer containing the inorganic compound formed by the wet method is suitable in that the release layer is excellent in coating suitability. Further, the layer containing the inorganic compound formed by the wet method is suitable because it is easy to improve the adhesion to the layer directly underneath (for example, a transparent plastic film or a hard coat layer).
Further, among the wet methods, a method of applying and drying a coating liquid containing inorganic particles as an inorganic compound and a binder resin composition is preferable. That is, the layer containing the inorganic compound preferably contains inorganic particles as the inorganic compound and a binder resin.

The particle size of the inorganic particles is not particularly limited, but the average primary particle size is preferably 5 to 200 nm, more preferably 10 to 150 nm, from the viewpoint of transparency and suppression of particle dropout.

The average primary particle diameter of the inorganic particles can be calculated by the following operations (1) to (3).
(1) The cross section of the releasable laminated body is imaged by TEM or STEM. The acceleration voltage of TEM or STEM is preferably 10 kv to 30 kV, and the magnification is preferably 50,000 to 300,000 times.
(2) Arbitrary 10 primary particles are extracted from the observation image, and the particle size of each primary particle is calculated. The particle size is measured as the distance between straight lines in a combination of two straight lines such that the distance between the two straight lines is maximized when the cross section of the primary particle is sandwiched between two arbitrary parallel straight lines.
(3) The same operation is performed 5 times on the observation image on another screen of the same sample, and the value obtained from the number average of a total of 50 particles is taken as the average particle size of the primary particles.

Examples of the inorganic particles include silica, magnesium fluoride, alumina, zirconia and titania. Among these, low refractive index inorganic particles such as silica and magnesium fluoride are preferable from the viewpoint of reducing the reflectance. When the reflectance is lowered, it can be suitably used for applications where visibility is important, such as showcases, show windows and windows.
Further, the low refractive index inorganic particles preferably have voids from the viewpoint of lowering the reflectance. Inorganic particles having voids have fine voids inside and contain air in the voids, so that the refractive index is low. Examples of the inorganic particles having voids include porous inorganic particles and hollow inorganic particles, and hollow inorganic particles are particularly preferable. Further, among the hollow inorganic particles, hollow silica is preferable.

Hollow inorganic particles refer to particles having an outer shell layer made of an inorganic compound, the inside of the particles surrounded by the outer shell layer is hollow, and the inside of the particles contains air.
The shape of the hollow inorganic particles may be a substantially spherical shape such as a true sphere, a spheroid shape, or a polyhedral shape that can be approximated to a sphere, a chain shape, a needle shape, a plate shape, a piece shape, a rod shape, a fibrous shape, or the like. .. Among them, it is preferably a true spherical shape and a substantially spherical shape, and more preferably a spheroidal shape or a true spherical shape.

While the hollow inorganic particles can have a low refractive index, they tend to be inferior in water resistance and scratch resistance as compared with other low refractive index inorganic particles. In particular, when hollow particles having a large particle size with an increased proportion of air are used, the water resistance and scratch resistance of the layer containing the inorganic compound are likely to be lowered.
However, the releasable laminate of the present invention has weak points (water resistance and water resistance) of the hollow inorganic particles due to the releasable layer located on the layer containing the inorganic compound even when the layer containing the inorganic compound contains the hollow inorganic particles. Deterioration of scratch resistance) can be compensated. Further, when the layer containing the inorganic compound contains hollow inorganic particles, by performing the treatment described later on the surface of the layer containing the inorganic compound, the adhesion between the layer containing the inorganic compound and the release layer is improved, and the hollow layer is formed. It is preferable in that it can more compensate for the weak points of the inorganic particles (decrease in water resistance and scratch resistance).

The low-refractive index inorganic particles may be surface-treated, but from the viewpoint of enhancing the adhesion between the layer containing the inorganic compound and the release layer, those having no surface treatment are preferable.

The content of the inorganic particles is preferably 20 to 250 parts by mass, more preferably 30 to 230 parts by mass, and even more preferably 40 to 200 parts by mass with respect to 100 parts by mass of the binder resin of the layer containing the inorganic compound.
By setting the content of the inorganic particles to 20 parts by mass or more, it is possible to easily improve the adhesion between the layer containing the inorganic compound and the release layer. Further, when the inorganic particles are low refractive index inorganic particles, the antireflection property can be improved by setting the content of the inorganic particles to 20 parts by mass or more.
Further, by setting the content of the inorganic particles to 250 parts by mass or less, it is possible to suppress a decrease in the coating film strength of the layer containing the inorganic compound, and thus it is possible to easily suppress a decrease in the scratch resistance of the releasable laminate.
Further, as the low refractive index inorganic particles, the hollow inorganic particles and other low refractive index inorganic particles can be used in combination. In this case, the ratio of the hollow inorganic particles to the total amount of the low refractive index inorganic particles is preferably 50% by mass or more, more preferably 60% by mass or more and 95% by mass or less, and further preferably 70% by mass or more and 90% by mass or less.

The binder resin of the layer containing the inorganic compound preferably contains a cured product of a curable resin composition such as a thermosetting resin composition or an ionizing radiation curable resin composition, from the viewpoint of improving scratch resistance. , It is more preferable to contain a cured product of the ionizing radiation curable resin composition.

The binder resin of the layer containing the inorganic compound preferably contains substantially no fluorine component from the viewpoint of adhesion to the release layer and application suitability of the release layer coating liquid.
The term "substantially free" means that the content of the fluorine component in terms of fluorine atoms with respect to the total amount of the binder resin of the layer containing the inorganic compound is 1% by mass or less, preferably 0.1% by mass or less, and more preferably 0. It is 0.01% by mass or less, more preferably 0% by mass.

The thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition that is cured by heating.
Examples of the thermosetting resin include acrylic resin, urethane resin, phenol resin, urea melamine resin, epoxy resin, unsaturated polyester resin, silicone resin and the like. To the thermosetting resin composition, a curing agent is added to these curable resins as needed.

The ionizing radiation curable resin composition is a composition containing a compound having an ionizing radiation curable functional group (hereinafter, also referred to as “ionizing radiation curable compound”). Examples of the ionizing radiation curable functional group include an ethylenically unsaturated bond group such as a (meth) acryloyl group, a vinyl group and an allyl group, an epoxy group and an oxetanyl group. As the ionizing radiation curable compound, a compound having an ethylenically unsaturated bond group is preferable, a compound having two or more ethylenically unsaturated bond groups is more preferable, and a compound having two or more ethylenically unsaturated bond groups is particularly preferable. Polyfunctional (meth) acrylate compounds are even more preferred. As the polyfunctional (meth) acrylate compound, either a monomer or an oligomer can be used.
The ionizing radiation means an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing or cross-linking a molecule, and usually, an ultraviolet ray (UV) or an electron beam (EB) is used. Electromagnetic waves such as X-rays and γ-rays, and charged particle beams such as α-rays and ion rays can also be used.
In the present specification, (meth) acrylate means acrylate or methacrylate, (meth) acrylic acid means acrylic acid or methacrylic acid, and (meth) acryloyl group means acryloyl group or methacryloyl group. means.

Among the polyfunctional (meth) acrylate compounds, the bifunctional (meth) acrylate monomers include ethylene glycol di (meth) acrylate, bisphenol A tetraethoxydiacrylate, bisphenol A tetrapropoxydiacrylate, and 1,6-hexane. Examples thereof include diol diacrylate.
Examples of the trifunctional or higher functional (meth) acrylate-based monomer include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and di. Examples thereof include pentaerythritol tetra (meth) acrylate and isocyanuric acid-modified tri (meth) acrylate.
Further, the (meth) acrylate-based monomer may be one in which a part of the molecular skeleton is modified, and is modified with ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, cyclic alkyl, aromatic, bisphenol and the like. Can also be used.

Examples of the polyfunctional (meth) acrylate-based oligomer include acrylate-based polymers such as urethane (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, and polyether (meth) acrylate.
Urethane (meth) acrylate is obtained, for example, by reacting a polyhydric alcohol and an organic diisocyanate with a hydroxy (meth) acrylate.
Further, the preferable epoxy (meth) acrylate is a (meth) acrylate obtained by reacting a (meth) acrylic acid with a trifunctional or higher functional aromatic epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin, or the like, and a bifunctional one. (Meta) acrylate obtained by reacting the above aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, etc. with polybasic acid and (meth) acrylic acid, and bifunctional or higher functional aromatic epoxy resin, It is a (meth) acrylate obtained by reacting an alicyclic epoxy resin, an aliphatic epoxy resin or the like with phenols and (meth) acrylic acid.
The ionizing radiation curable compound may be used alone or in combination of two or more.

When the ionizing radiation curable compound is an ultraviolet curable compound, the ionizing radiation curable composition preferably contains an additive such as a photopolymerization initiator or a photopolymerization accelerator.
Examples of the photopolymerization initiator include one or more selected from acetophenone, benzophenone, α-hydroxyalkylphenone, Michler ketone, benzoin, benzyldimethylketal, benzoylbenzoate, α-acyloxime ester, thioxanthones and the like.
Further, the photopolymerization accelerator can reduce the polymerization inhibition due to air at the time of curing and accelerate the curing rate. For example, from p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic acid ethyl ester and the like. One or more selected species can be mentioned.

When the layer containing the inorganic compound contains the inorganic particles as the inorganic compound and the binder resin, the inorganic particles are present on at least a part of the surface of the layer containing the inorganic compound (the surface of the layer containing the inorganic compound on the release layer side). It is preferably exposed. Since the inorganic particles are exposed from the surface of the layer containing the inorganic compound, it is possible to easily improve the adhesion between the layer containing the inorganic compound and the release layer.
In order to expose the inorganic particles from the surface of the layer containing the inorganic compound, the surface of the layer containing the inorganic compound is subjected to corona discharge treatment after the formation of the layer containing the inorganic compound, or the surface of the layer containing the inorganic compound is subjected to corona discharge treatment. It is preferable to perform saponification treatment. When the layer containing the inorganic particles and the binder resin is formed, the surface of the inorganic particles is covered with the binder resin. Here, the thickness of the binder resin covering the surface of the inorganic particles may be thick or thin depending on the location. Then, on the surface of the inorganic particles thinly covered with the binder resin, the thin-skinned binder resin is removed by the above-mentioned corona discharge treatment or saponification treatment, and the inorganic particles are exposed.

The layer containing the inorganic compound preferably contains a silane coupling agent from the viewpoint of further improving the adhesion to the release layer and maintaining the release property of the adhesive due to the dropping of water for a longer period of time.
The silane coupling agent is an alkoxysilane such as tetraethoxysilane and methyltriethoxysilane; a vinyl-based silane coupling agent such as vinyltrimethoxysilane and vinyltriethoxysilane; 3-methacryloxypropyltriemethoxysilane, 3-methacryloxy. Silane coupling agents containing (meth) acryloyl groups such as propylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane and 3-acryloxypropyltriethoxysilane; epoxy-based silane coupling agents; amino-based silane coupling agents. Agents and the like can be mentioned. Among these, a silane coupling agent containing a (meth) acryloyl group is preferable from the viewpoint of scratch resistance.

The content of the silane coupling agent is preferably 5 to 60% by mass, more preferably 7 to 45% by mass, still more preferably 10 to 30% by mass, based on the total solid content of the layer containing the inorganic compound.

The thickness of the layer containing the inorganic compound is not particularly limited, but when low refraction particles are used as the inorganic compound, it is preferably 70 to 120 nm and more preferably 80 to 110 nm from the viewpoint of suppressing reflectance. , 85-105 nm, more preferably.
The thickness of the layer containing the inorganic compound can be calculated from the average value of the values at 20 points by measuring the thickness at 20 points from the image of the cross section taken by, for example, a scanning transmission electron microscope (STEM). The thicknesses of the release layer, the hard coat layer, and the high refractive index layer, which will be described later, can be calculated in the same manner.

When low refractive index particles are used as the inorganic compound, the refractive index of the layer containing the inorganic compound (low refractive index layer) is preferably 1.26 to 1.37, preferably 1.28 to 1.35. It is more preferably 1.30 to 1.33, and even more preferably 1.30 to 1.33.
In the present specification, the refractive index can be calculated, for example, by fitting a reflection spectrum measured by a reflected photometer and a reflection spectrum calculated from an optical model of a multilayer thin film using a Fresnel coefficient.

<Release layer>
The release layer is formed on the outermost surface of the release layer.
The release layer needs not to swell or dissolve when water is dropped under the conditions 2 to 4.

The release layer is preferably a cured product of the release layer forming composition containing an organic solvent-dispersed silica sol.
The organic solvent-dispersed silica sol is a colloidal solution in which colloidal silica having a particle size of nano-order is dispersed in an organic solvent. By applying the release layer forming composition containing the organic solvent-dispersed silica sol and dehydrating and condensing the silica sol by heating or the like, a cured product of the release layer forming composition containing the organic solvent-dispersed silica sol can be obtained. Examples of the organic solvent of the organic solvent-dispersed silica sol include alcohols, glycols, esters, ketones, ethers, saturated hydrocarbons, unsaturated hydrocarbons and the like.
The particle size of the silica sol is preferably 1 to 20 nm from the viewpoint that the thickness of the release layer is within the range described later.

Specific examples of the organic solvent-dispersed silica sol include IPA-ST (particle size of about 12 nm), IPA-ST-UP (particle size of about 9 to 15 nm), and MIBK-ST (particle size of about 12 nm) manufactured by Nissan Chemical Industries, Ltd. ), PMA-ST (particle diameter about 12 nm) and PGM-ST (particle diameter about 12 nm), MIBK-SD (particle diameter about 12 nm); trade name PL-1-IPA (10 to 15 nm) manufactured by Fuso Chemical Industry Co., Ltd. , PL-1-TOR (10 to 15 nm), PL-1-PGME (10 to 15 nm), PL-1-MEK (10 to 15 nm); trade name Surria manufactured by JGC Catalysts and Chemicals Co., Ltd. and the like can be mentioned.

Further, the release layer is preferably a cured product of the release layer forming composition containing a modified product of the organic solvent-dispersed silica sol. Examples of the modified product of the organic solvent-dispersed silica sol include those obtained by reacting silanol of the silica sol with a silane coupling agent represented by the following formula (I).
The cured product of the composition containing the modified product (a reaction of silanol of silica sol and a silane coupling agent represented by the following formula (I)) has a high level of hydrophilicity while being organic. Since it has adhesiveness to the adhesive tape due to the presence of the group, it is possible to easily satisfy the condition 1. Further, the cured product of the composition containing the modified product has a high level of hydrophilicity, and water enters between the adhesive tape adhering to the release layer and the surface of the release layer, and the adhesive force of the adhesive tape is obtained. Can be weakened to make it easier to satisfy condition 2. Further, the cured product of the composition containing the modified product has excellent adhesion to the layer containing the inorganic compound, and the scratch resistance of the releasable laminate can be improved, so that condition 3 can be easily satisfied. .. Further, since the cured product of the composition containing the modified product has a low refractive index of about 1.4, the reflectance can be easily lowered.
The above-mentioned actions are "having a minute hydrophilic domain and a hydrophobic domain on the surface of the cured product of the composition containing the modified product" and "the energy of water coordination to the hydrophilic domain> the hydrophobic domain and the components of the pen. It is thought that this is caused by the fact that the relationship of binding force is established. Further, it is considered that the reason why the release layer does not peel off when water is dropped is that the modified product and the inorganic compound in the layer containing the inorganic compound are chemically bonded.

(W) _3-k (R) _k Si-R ^1- (X-R ² ) _m -N ⁺ (R ³ ) (R ⁴ ) -R ⁵ -Y (I)
[In the formula (I), W represents an alkoxy group having 1 to 3 carbon atoms, R represents an alkyl group having 1 to 3 carbon atoms, k represents 0 or 1, and R ¹ represents 1 to 5 carbon atoms. Represents an alkylene group, X represents -NHCOO-, -NHCONH- or -S-, m represents 0 or 1, R ² represents an ether bond, an ester bond or an amide bond and may contain 1 to 10 carbon atoms. Represents an alkylene group or -CH ₂ CH ₂ N ⁺ (CH ₃ ) {(CH ₂ ) _n Y)} CH ₂ CH ₂ OCH ₂ CH _2- , where R ³ and R ⁴ may have the same or different carbon atoms. Represents an alkyl group of 3 to 3, R ⁵ represents a methylene group, an ethylene group, a propylene group or a methylene phenylene group, ^and Y represents -COO- ^or -SO _3- . ]

Examples of the R (alkyl group having 1 to 3 carbon atoms) of the above formula (I) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group and the like, and among these, a methyl group is preferable.
Examples of R ¹ (alkylene group having 1 to 5 carbon atoms) of the above formula (I) include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group and a pentamethylene group, and among these, a trimethylene group is preferable.
R ² of the above formula (I) includes an ethylene group, a trimethylene group, an ethyleneoxyethylene group and −CH ₂ CH ₂ N ⁺ (CH ₃ ) {(CH ₂ ) _n Y)} CH ₂ CH ₂ OCH ₂ CH ₂ -Is preferable.
Examples of the alkyl group having 1 to 3 carbon atoms of R ³ and R ⁴ of the above formula (I) include a methyl group and an ethyl group, and among these, a methyl group is preferable.

Specific examples of the silane coupling agent of the above formula (I) include the following compounds.
(CH ₃ O) ₃ SiCH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ ^COO-
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCOOCH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ ^COO-
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCOOCH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ ^COO-
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCOOCH ₂ CH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ ^COO-
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCOOCH ₂ CH ₂ OCH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ ^COO-
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCOOCH ₂ CH ₂ N ⁺ (CH ₃ ) (CH ₂ ^COO- ) CH ₂ CH ₂ OCH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ ^COO-
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCONHCH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ ^COO-
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCONHCH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ ^COO-
(CH ₃ O) ₃ SiCH ₂ CH ₂ CH ₂ SCH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ ^COO-
(CH ₃ O) ₃ SiCH ₂ CH ₂ CH ₂ SCH ₂ CH ₂ COOCH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ ^COO-
(CH ₃ O) ₃ SiCH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ ^COO-
(CH ₃ O) ₃ SiCH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ C ₆ H ₄ ^COO-
(C ₂ H ₅ O) ₂ Si (CH ₃ ) CH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ ^COO-
(CH ₃ O) ₃ SiCH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ CH ₂ SO ₃ ^－
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCOOCH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ CH ₂ SO ₃ ^－
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCOOCH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ CH ₂ SO ₃ ^－
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCOOCH ₂ CH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CCH ₂ CH ₂ CH ₂ SO ₃ ^－
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCOOCH ₂ CH ₂ OCH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ CH ₂ SO ₃ ^－
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCOOCH ₂ CH ₂ N ⁺ (CH ₃ ) (SO _3- ⁾ CH ₂ CH ₂ OCH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ CH ₂ ^SO _3-
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCONHCH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ CH ₂ SO ₃ ^－
(C ₂ H ₅ O) ₃ SiCH ₂ CH ₂ CH ₂ NHCONHCH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ CH ₂ SO ₃ ^－
(CH ₃ O) ₃ SiCH ₂ CH ₂ CH ₂ SCH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ CH ₂ SO ₃ ^－
(CH ₃ O) ₃ SiC ₂ CH ₂ CH ₂ SCH ₂ CH ₂ COOCH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ CH ₂ SO ₃ ^－
(C ₂ H ₅ O) ₂ Si (CH ₃ ) CH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ CH ₂ SO ₃ ^－

The silane coupling agent of the formula (I) can be obtained by reacting a dialkylamino group-containing silicon compound (for example, a dimethylamino group-containing silicon compound) with a haloacetic acid compound, a sultone ring compound or a lactone ring compound.

The temperature at which the silane coupling agent of the formula (I) is added is not limited, but is preferably between about 20 ° C. and the boiling point of the solvent.
The reaction temperature is also not limited, but is preferably between about 20 ° C. and the boiling point of the solvent.
The reaction time is also not limited, but is preferably 10 minutes to 48 hours, more preferably 6 hours to 24 hours.

As the solvent used in the reaction for obtaining the silane coupling agent of the formula (I), the ester solvent: methyl acetate, ethyl acetate, butyl acetate, etc., and the alcohol solvent: methanol, ethanol, isopropanol, n-butanol, tert- Butanol, pentanol, ethylene glycol, propylene glycol, propylene glycol monomethyl ether, 1,4-butanediol, etc., ether solvent: diethyl ether, tetrahydrofuran, dioxane, etc., ketone solvent: acetone, methyl ethyl ketone, etc., aproton solvent : Dimethylsulfoxide, N, N-dimethylformamide and the like, aromatic hydrocarbon solvents: toluene and xylene and the like, and mixed solvents thereof and the like can be mentioned.

The reaction temperature at the time of obtaining the silane coupling agent of the formula (I) is preferably the boiling point of the solvent used or higher, and the reaction may be carried out under pressure to make the temperature higher than the boiling point.
The reaction time is usually 6 to 36 hours, preferably 8 to 36 hours, more preferably 8 to 24 hours.

As the dimethylamino group-containing silicon compound which is the raw material of the silane coupling agent of the formula (I), a commercially available product can be used as it is.
Alternatively, commercially available dimethylamino group-containing alcohols (eg: 2-dimethylaminoethanol, 3-dimethylaminopropanol, 4-dimethylaminobutanol, 2-dimethylaminoethoxyethanol and N, N, N'-trimethyl-N'-( 2-Hydroxyethyl) -bis (2-aminoethyl ether, etc.) is reacted with a silane coupling agent having an isocyanate group (for example, 3-isocyanatepropyltriethoxysilane, etc.) to react with a compound having an -NHCOO- group or a commercially available compound. A silane coupling agent having an isocyanate group in a dimethylamino group-containing amine (for example, N, N-dimethylethylenediamine, N, N-dimethyl-1,3-propanediamine, etc.) (for example, 3-isocyanatepropyltriethoxysilane, etc.) Can be reacted to obtain a compound having a -NHCONH- group and used.
Further, dimethylallylamine, 2- (dimethylamino) ethyl acrylate, 2- (dimethylamino) ethyl methacrylate, N- [3- (dimethylamino) propyl] acrylamide, N- [3- (dimethylamino) propyl] methacrylicamide, etc. It can also be used by reacting with a thiol group-containing silicon compound (for example, 3-mercaptopropyltrimethoxy, 3-mercaptopropylmethyldimethoxysilane, etc.) to obtain a thioether group-containing silicon compound.

The solvent used for reacting the silica sol silanol with the silane coupling agent of the formula (I) is an alcohol solvent: methanol, ethanol, isopropanol, n-butanol, t-butanol, pentanol, ethylene glycol, propylene glycol. And 1,4-butanediol, etc., ether solvent: diethyl ether, tetrahydrofuran, dioxane, etc., ketone solvent: acetone, methyl ethyl ketone, etc., aproton solvent: dimethylsulfoxide, N, N-dimethylformamide, etc., water And a mixed solvent thereof and the like.
Of these, alcoholic solvents and water are preferable, and these solvents can be used alone or in combination of two or more.

The amount of the raw material silica sol with respect to 100 parts by mass of the solvent is preferably 1 to 50 parts by weight, more preferably 1 to 30 parts by weight.

The amount of the silane coupling agent of the formula (I) with respect to the silica sol is preferably 0.1 to 10.0 mmol, more preferably 0.5 to 5.5 mmol with respect to 1 g of the silica sol.
When it is 0.1 mmol or more, the hydrophilicity of the cured product can be easily improved, and when it is 10.0 mmol or less, self-condensation between silane coupling agents is suppressed and the silanol group of the silica sol is insufficient. Therefore, it is possible to prevent the hardness of the cured product from being insufficient and the scratch resistance of the release layer from being lowered.

The above-mentioned modified product of the organic solvent-dispersed silica sol (a product obtained by reacting silanol of the silica sol with the silane coupling agent of the formula (I)) is modified with the functional group represented by the following formula (II). ..
(-O-) _3-k (R) _k Si-R ^1- (X-R ² ) _m -N ⁺ (R ³ ) (R ⁴ ) -R ⁵ -Y (II)
The embodiment of each code (k, R, Y, etc.) of the formula (II) is the same as the embodiment of each code of the above formula (I).

Further, examples of the modified product of the organic solvent-dispersed silica sol include those obtained by reacting silanol of the silica sol with a silane coupling agent containing a (meth) acryloyl group.
Examples of the silane coupling agent containing such a (meth) acryloyl group include 3-methacryloxypropyltriemethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane and 3-acryloxy. Examples thereof include propyltriethoxysilane.

The release layer forming composition containing the modified product of the organic solvent-dispersed silica sol may further contain other curing components such as a normal organic solvent-dispersed silica sol and a curable resin composition.
As the curable resin composition contained in the release layer forming composition, the same curable resin composition as that exemplified for the layer containing the inorganic compound can be used. By including the curable resin composition in the release layer forming composition, the adhesion to the layer containing the inorganic compound can be further enhanced.
The content of the curable resin composition is 5 to 30 parts by mass with respect to 100 parts by mass of the active ingredient of the silica sol from the viewpoint of the balance between the hydrophilicity of the release layer and the adhesion to the layer containing the inorganic compound. Is preferable.

The release layer forming composition can be cured by dehydrating and condensing the silica sol after being applied and dried on, for example, a plastic film or a layer containing an inorganic compound. The dehydration condensation of the silica sol also proceeds by heat treatment, but in order to promote the dehydration condensation, it is preferable to use a catalyst such as a base and an acid. The catalyst may be added to the release layer forming composition, or the release layer may be exposed to the catalyst atmosphere after the release layer is formed.
The temperature conditions for dehydration condensation of the silica sol are not particularly limited, and may be appropriately determined in the range of 20 to 250 ° C.
When the release layer forming composition contains the curable resin composition, the curing of the silica sol and the curing of the curable resin composition may be performed at the same time, or either one may be performed first.

The thickness of the release layer is preferably 1 to 25 nm, more preferably 3 to 20 nm, and even more preferably 5 to 15 nm.
By setting the thickness of the release layer to 1 nm or more, the scratch resistance of the release layer can be easily improved. Further, by setting the thickness of the release layer to 25 nm or less, deterioration of the antireflection performance can be suppressed. Further, by setting the thickness of the release layer to 25 nm or less, the molecules constituting the release layer are arranged in an orderly manner and have a high degree of hydrophilicity, so that it is considered that the condition 2 can be easily satisfied.

The refractive index of the release layer is preferably 1.49 or less, more preferably 1.46 or less. By setting the refractive index of the release layer to 1.49 or less, it is possible to further suppress the deterioration of the antireflection performance when the layer containing the inorganic compound has a low refractive index.
The lower limit of the refractive index of the release layer is about 1.30.

<Hard coat layer>
It is preferable to have a hard coat layer between the transparent plastic film and the release layer in order to enhance scratch resistance. When a layer containing an inorganic compound is provided between the transparent plastic film and the release layer, it is preferable to have a hard coat layer between the transparent plastic film and the layer containing the inorganic compound.

The hard coat layer preferably contains a cured product of a curable resin composition such as a thermosetting resin composition or an ionizing radiation curable resin composition, and from the viewpoint of improving scratch resistance, the ionizing radiation curable resin. It is more preferable to include a cured product of the composition.
As the thermosetting resin composition and the ionizing radiation curable resin composition of the hard coat layer, the same ones as the thermosetting resin composition and the ionizing radiation curable resin composition of the layer containing the above-mentioned inorganic compound shall be used. Can be done.

The thickness of the hard coat layer is preferably 0.1 to 100 μm, more preferably 0.5 to 20 μm, and even more preferably 1 to 10 μm. By setting the thickness of the hard coat layer within the above range, it is possible to easily suppress the occurrence of curl while improving the scratch resistance.

The refractive index of the hardcourt layer is preferably adjusted in the range of 1.45 to 1.70. Further, when the layer containing the inorganic compound has a low refractive index, the refractive index of the hard coat layer is high when the layer containing the low refractive index has a high refractive index in contact with the transparent plastic film side. It is preferably lower than the refractive index of the refractive index layer, more preferably 1.50 to 1.65, and even more preferably 1.55 to 1.60. If the refractive index of the hard coat layer is within such a range, the hard coat layer has a role as a medium refractive index layer, and the hard coat layer (medium refractive index layer), the high refractive index layer, and the low refractive index layer ( Since the interference action of the three layers (the layer containing the inorganic compound having a low refractive index) is possible, the refractive index can be lowered.

Examples of the means for imparting the role of the medium refractive index layer to the hard coat layer include means for blending a resin having a high refractive index in the hard coat layer coating liquid and means for blending particles having a high refractive index.
Examples of the resin having a high refractive index include those obtained by introducing a group containing sulfur, phosphorus, bromine, an aromatic ring, or the like into the above-mentioned thermosetting resin or ionizing radiation curable compound. Examples of the particles having a high refractive index include those similar to the high refractive index particles used for the high refractive index layer described later.

<High refractive index layer>
When the layer containing the inorganic compound has a low refractive index, the high refractive index layer is in contact with the transparent plastic film side of the layer containing the low refractive index from the viewpoint of lowering the reflectance of the releasable laminate. It is preferable to have.
The high refractive index layer can be formed from, for example, a high refractive index layer coating liquid containing high refractive index particles and a binder resin composition.

Examples of the high refractive index particles include antimony pentoxide, zinc oxide, titanium oxide, cerium oxide, tin-doped indium oxide, antimony-doped tin oxide, yttrium oxide and zirconium oxide.
The average particle size of the primary particles of the high refractive index particles is preferably 3 to 200 nm, more preferably 5 to 100 nm, and even more preferably 7 to 50 nm.

The content of the high-refractive index particles is preferably 50 to 1000 parts by mass and 100 to 750 parts by mass with respect to 100 parts by mass of the binder resin from the viewpoint of increasing the refractive index of the coating film and balancing the strength of the coating film. It is more preferably parts, and even more preferably 200 to 500 parts by mass.

Examples of the binder resin of the high refractive index layer include a cured product of a curable resin composition. As the curable resin composition, the same ones as those exemplified for the layer containing the inorganic compound can be used, and the ionizing radiation curable resin composition is suitable.

The refractive index of the high refractive index layer is preferably 1.55 to 1.85, more preferably 1.56 to 1.75.
The thickness of the high refractive index layer is preferably 200 nm or less, more preferably 50 to 180 nm.

<Other layers>
The releasable laminate of the present invention may have other layers.
For example, an adhesive layer, an antistatic layer, a printing layer, and the like may be provided on the surface of the transparent plastic film opposite to the layer containing the inorganic compound.

<Other physical characteristics>
When the releasable laminate is used for showcases, show windows, windows, etc., the haze of JISK7136: 2000 is preferably less than 2.0%, preferably 1.5% or less, from the viewpoint of improving visibility. It is more preferably present, and further preferably 1.0% or less.
The portion having light transmittance is a portion where the light transmittance is lowered (total light transmittance) due to, for example, a printing layer being formed on the surface of the transparent plastic film opposite to the layer containing the inorganic compound. The intention is to exclude (where the rate is 50% or less).

The surface of the mold release laminate on the release layer side preferably has an arithmetic mean roughness Ra (JIS B0601: 1994) with a cutoff value of 0.08 mm of 0.02 μm or less, preferably 0.01 μm or less. Is more preferable.

The reflectance of the surface of the releasable laminate on the release layer side is preferably 2.0% or less, more preferably 1.5% or less, still more preferably 1.0% or less. .. By lowering the reflectance, the visibility becomes good, and it can be suitably used for showcases, show windows, windows and the like.

In the present specification, the reflectance means the visual reflectance Y value of the CIE 1931 standard color system, and means the average value of 10-point measurement.
Further, in the present specification, the reflectance of the surface of the releasable laminate on the release layer side is such that a black plate is provided on the side opposite to the reflectance measurement surface of the releasable laminate via a transparent pressure-sensitive adhesive layer. A bonded sample is prepared, and light is incident at an incident angle of 5 ° from the release layer side of the sample for measurement. The light source for measuring the reflectance is preferably D65.
The difference in refractive index between the member in contact with the transparent pressure-sensitive adhesive layer (for example, a transparent plastic film) of the sample and the transparent pressure-sensitive adhesive layer is preferably 0.15 or less, and more preferably 0.10 or less. The black plate preferably has a total light transmittance of JIS K7361-1: 1997 of 1% or less, and more preferably 0%. Further, the difference in the refractive index between the refractive index of the resin constituting the black plate and the transparent pressure-sensitive adhesive layer is preferably 0.15 or less, and more preferably 0.10 or less.

<Size, shape, etc.>
The releasable laminate may be in the form of a single leaf or in the form of a roll.
The size of the single leaf is not particularly limited, but generally, the size is about 2 to 500 inches diagonally. The width and length of the roll are not particularly limited, but generally, the width is 500 to 3000 mm and the length is about 500 to 5000 m.
Further, the shape of the single leaf is not particularly limited, and may be, for example, a polygon (triangle, quadrangle, pentagon, etc.), a circle, or a random irregular shape.

<Use>
The releasable laminate of the present invention described above can be used, for example, as a releasable substrate for a transfer sheet and a process sheet, and can also be used as a surface member for a showcase, a show window, and a window.

[Transfer sheet]
The transfer sheet of the present invention comprises a transfer layer on the release layer of the above-mentioned releasable laminate of the present invention.
That is, the transfer sheet of the present invention uses the above-mentioned releasable laminate as the releasable substrate of the transfer sheet.

In the transfer sheet of the present invention, in the stage before the initial transfer, the release layer is sufficiently adhered to the releasable laminate (release base material), and after the transfer layer is adhered to the adherend, the transfer layer is adhered to the adherend. The releasable laminate (release base material) can be easily peeled off from the transfer layer by a simple process of dropping water.

Examples of the transfer layer of the transfer sheet include a configuration having a functional layer and an adhesive layer. In this configuration, the functional layer is arranged on the releasable laminate (releasable substrate) side. Examples of the functional layer include a hard coat layer, an antireflection layer and an antifouling layer.

[Process sheet]
The process sheet of the present invention has the release layer of the above-mentioned releasable laminate of the present invention on the outermost surface.

In the process sheet of the present invention, electronic parts and the like are adhered with sufficient adhesive force via an adhesive, and after the process is completed, processed electronic parts and the like are removed from the process sheet by a simple process of dropping water. Can be easily peeled off.

[Article]
The article of the present invention is formed by arranging the release layer of the above-mentioned releasable laminate of the present invention so as to face the surface.

Articles include showcases, show windows and windows. That is, the article of the present invention includes a showcase, a show window, and a window in which the release layer of the releaseable laminate is arranged so as to face the surface.
In the article of the present invention, while the display object such as an advertisement is fixed with an adhesive tape with sufficient adhesive force, when the display object is changed, the display object can be easily peeled off by a simple process of dropping water.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited to the embodiments described in the examples.

1. 1. Evaluation and measurement The following measurements and evaluations were performed on the releasable laminates obtained in Examples and Comparative Examples. The results are shown in Table 1.

1-1. Confirmation of conditions 1 to 3 (1)
Adhesive tape A1 having a peel strength of 3 N / 10 mm in Method 1 (180 ° peeling from a stainless steel test plate) of JIS Z0237: 2009 is prepared, and peel strengths P1 (N / 10 mm) and P2 (N / 10 mm) under conditions 1 to 3 are prepared. ) And P3 (N / 10 mm) were measured, and it was confirmed whether or not the conditions 1 to 3 were satisfied. Those satisfying each condition were designated as "A", and those not satisfying each condition were designated as "C". A Tensilon universal tester manufactured by Orientec Co., Ltd. was used to measure the peel strength, and the peel speed was set to 300 mm / min.
The atmosphere when conditions 1 to 3 were performed was a temperature of 23 ° C. ± 5 ° C. and a humidity of 40 to 65%. Further, before carrying out the conditions 1 to 3, each sample was left in the atmosphere for 10 minutes or more.
Further, under conditions 3 and 4, the reciprocating friction was performed using a Gakushin type friction tester conforming to JIS L0849: 2013 at a speed of 30 mm one way and 1 second per reciprocation.
Further, in conditions 2 and 3, ion-exchanged water was used as the water. Further, under the conditions 1 to 3, the width of the adhesive tape was set to 10 mm, and the length of the region bonded to the releasable laminate was 50 mm in the total length of the adhesive tape. Further, under the conditions 2 to 3, the amount of water dropped was 20 ml.

1-2. Confirmation of conditions 1 to 3 (2)
Prepare an adhesive tape A2 having a peel strength of 7 N / 10 mm in Method 1 (180 ° peeling from a stainless steel test plate) of JIS Z0237: 2009, and determine whether conditions 1 to 3 are satisfied in the same manner as 1-1 above. confirmed.

1-3. Steel wool resistance (SW resistance)
After the releasable laminates of Examples and Comparative Examples were cut into a size of 5.0 cm × 5.0 cm, a transparent adhesive layer having a thickness of 25 μm (manufactured by Panac Co., Ltd., trade name: Panaclean) was placed on the transparent plastic film side. A sample (5.0 cm × 5.0 cm) was prepared by laminating PD-S1) and a transparent glass plate having a thickness of 2 mm.
After pressing # 0000 steel wool against the surface of the sample on the release layer side and rubbing it 10 times with a load of 500 g / cm ² , a black plate is placed on the back of the sample, and the release layer is illuminated by a fluorescent lamp. It was visually evaluated whether or not the scratches could be visually recognized from the side. Those with invisible scratches were designated as "A", and those with visible scratches were designated as "C". Further, regarding the evaluation A with a load of 500 g / cm ² , when the same evaluation was performed with a load of 700 g / cm ² , the one in which no scratch was visible was designated as "AA".

1-4. Reflectance (visual reflectance Y value)
A black plate is interposed on the transparent plastic film side of the releasable laminates of Examples and Comparative Examples with a transparent adhesive layer (manufactured by Panac Co., Ltd., trade name: Panaclean PD-S1, refractive index 1.49) having a thickness of 25 μm. A sample (5 cm x 5 cm) was prepared by laminating (manufactured by Kuraray Co., Ltd., trade name: Comoglass DFA2CG 502K (black) system, total light transmittance 0%, thickness 2 mm, refractive index 1.49).
When the direction perpendicular to the surface of the releasable laminate is set to 0 degrees, light is incident on the sample from the direction of 5 degrees, and the reflectance of the sample (visual reflection) is based on the specular reflection of the incident light. Rate Y value) was measured.
The reflectance is measured by measuring the 5 ° regular reflectance in the wavelength range from 380 to 780 nm using a spectral reflectance measuring device (manufactured by Shimadzu Corporation, trade name: MPC3100), and then as the brightness perceived by human eyes. A value indicating the visual reflectance, which was calculated by the conversion software (built-in MPC3100), was obtained as the reflectance. The reflectance at 10 points was measured for each sample, and the average value was taken as the reflectance of each sample.

2. 2. Preparation of coating liquid The following coating liquid was prepared.
<Coating liquid for hard coat layer>
-Urethane acrylate (trade name "UX5005", manufactured by Nippon Kayakusha, 9-functional) 50 parts by mass-Pentaerythritol triacrylate 25 parts by mass-acrylate monomer (trade name "R684", manufactured by Nippon Kayakusha, 2-functional) 25 By mass, photopolymerization initiator (trade name "Irgacure 184", manufactured by BASF) 4 parts by mass, leveling agent (trade name "Megafuck F477", manufactured by DIC) 0.2 parts by mass, methyl ethyl ketone 125 parts by mass, propylene Glycol monomethyl ether acetate 25 parts by mass

<Coating liquid for layers containing inorganic compounds (low refractive index layer)>
・ Propylene oxide-modified pentaerythritol tetraacrylate (trade name “ATM-4P”, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., solid content 100%) 75 parts by mass ・ Pentaerythritol triacrylate 25 parts by mass ・ Hollow silica fine particle-containing dispersion (solid) 20% by mass, average primary particle diameter 60 nm) 800 parts by mass, reactive silica fine particle-containing dispersion (trade name "MIBK-SD", manufactured by Nissan Chemical Industries, Ltd., solid content 30%, average primary particle diameter 12 nm) 83 parts by mass・ Photopolymerization initiator (trade name “Irgacure 127”, manufactured by BASF) 7 parts by mass ・ Methyl isobutyl ketone 9300 parts by mass ・ Propropylene glycol monomethyl ether acetate 1100 parts by mass

<Release layer coating liquid 1>
5 parts by mass (solid content: about 0.08% by mass) of the solution containing the modified product of the following organic solvent-dispersed silica sol.
・ 45 parts by mass of ion-exchanged water ・ 5 parts by mass of isopropyl alcohol

<Solution containing modified organic solvent-dispersed silica sol>
Dehydrated ethyl acetate 40 ml of 1,2-oxathiolane 2,2-dioxide (manufactured by Tokyo Chemical Industry Co., Ltd.) 4.39 g and N, N-dimethyl-3-aminopropyltrimethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.) 7.26 g. It was dissolved in and stirred at room temperature for 24 hours. The white precipitate formed was filtered to obtain 8.5 g of N-propyltrimethoxysilane-N, N-dimethyl-N- (3-sulfopropyl) ammonium betaine.
Next, 4.0 g of N-propyltrimethoxysilane-N, N-dimethyl-N- (3-sulfopropyl) ammonium betaine, and an organic solvent-dispersed silica sol (manufactured by Nissan Chemical Industries, Ltd., IPA-ST (solid content 30%)). )) 13.2 g was dissolved in a solvent (a mixed solvent of 80 ml of ethanol and 140 ml of water) and heated under reflux overnight. After cooling, 520 mg of lithium hydroxide monohydrate (manufactured by Nakaraitesk Co., Ltd.) was dissolved in a small amount of water and added to the reaction solution for neutralization. By adding water to the obtained reaction solution to adjust the amount to 500 g, the mixture was modified with (-O-) ₃ SiCH ₂ CH ₂ CH ₂ N ⁺ (CH ₃ ) ₂ CH ₂ CH ₂ CH ₂ SO _3- group. 500 g of a solution containing a modified product of the organic solvent-dispersed silica sol was obtained (solid content: about 1.6% by mass).

<Coating liquid for mold release layer 2>
4 parts by mass (solid content: about 0.064 parts by mass) of the solution containing the modified product of the above organic solvent-dispersed silica sol.
・ Si ₅ O ₄ (OC ₂ H ₅ ) ₁₂ (Product name “Ethyl silicate 40”, manufactured by Corcote Co., Ltd.) 0.02 parts by mass (in terms of solid content)
・ 3-Metaloxypropyltriemethoxysilane 0.002 parts by mass ・ Ion-exchanged water 45 parts by mass ・ Isopropyl alcohol 5 parts by mass

3. 3. Preparation of releasable laminate [Example 1]
On a polyethylene terephthalate film (refractive index 1.65) having a thickness of 100 μm, the coating liquid for the hard coat layer of the above formulation was applied, dried (70 ° C., 1 minute) and irradiated with ultraviolet rays (100 mJ / cm ² ) to obtain a thickness of 10 μm. A hard coat layer was formed. Next, a coating liquid for a layer (low refractive index layer) containing the inorganic compound of the above formulation was applied onto the hard coat layer, dried (90 ° C., 1 minute) and irradiated with ultraviolet rays (200 mJ / cm ² ) to obtain a thickness of 90 nm. A layer containing an inorganic compound having a refractive index of 1.35 was formed.
Next, after corona discharge treatment is performed on the surface of the layer containing the inorganic compound, the release layer coating liquid 1 of the above formulation is applied, dried (100 ° C. for 1 minute), and further heat-treated at 110 ° C. for 15 minutes to cure the silica sol. (Dehydration condensation) was carried out to form a release layer, and a releaseable laminate of Example 1 was obtained. The theoretical thickness of the release layer based on the coating amount is 10 nm.
The coating liquid 1 for the release layer was formed to have a thickness at which the refractive index could be measured, and the refractive index was measured and found to be 1.43.

[Example 2]
A releasable laminate of Example 2 was obtained in the same manner as in Example 1 except that the thickness of the released layer was changed to 15 nm.

[Example 3]
A releasable laminate of Example 3 was obtained in the same manner as in Example 1 except that the thickness of the released layer was changed to 7 nm.

[Example 4]
The "hollow silica fine particle-containing dispersion (solid content 20%, average primary particle diameter 60 nm)" of the coating liquid for the layer containing the inorganic compound (low refractive index layer) is replaced with the "hollow silica fine particle-containing dispersion (solid content 20%)". , Average primary particle diameter 75 nm) ”, the releasable laminate of Example 4 was obtained in the same manner as in Example 1.

[Example 5]
The "hollow silica fine particle-containing dispersion (solid content 20%, average primary particle diameter 60 nm)" of the coating liquid for the layer containing the inorganic compound (low refractive index layer) is replaced with the "hollow silica fine particle-containing dispersion (solid content 20%)". , Average primary particle diameter 50 nm) ”, the releasable laminate of Example 5 was obtained in the same manner as in Example 1.

[Example 6]
The "hollow silica fine particle-containing dispersion (solid content 20%, average primary particle diameter 60 nm)" of the coating liquid for the layer containing the inorganic compound (low refractive index layer) is replaced with the "hollow silica fine particle-containing dispersion (solid content 20%)". , Average primary particle diameter 100 nm) ”, the releasable laminate of Example 6 was obtained in the same manner as in Example 1.

[Example 7]
The releasable laminate of Example 7 is the same as in Example 1 except that a high refractive index layer (refractive index 1.65, thickness 165 nm) is formed between the hard coat layer and the layer containing the inorganic compound. Got
The high refractive index layer was formed by applying the following coating liquid for a high refractive index layer, drying (90 ° C., 1 minute), and irradiating with ultraviolet rays (200 mJ / cm ² ).
<Coating liquid for high refractive index layer>
・ Pentaerythritol triacrylate (trade name PET30, manufactured by Nippon Kayaku Co., Ltd., solid content 100%) 100 parts by mass ・ Antimony pentoxide-containing dispersion (trade name “V-4564”, manufactured by JGC Catalysts and Chemicals Co., Ltd., solid content 40%) , Average primary particle diameter 20 nm) 1100 parts by mass, fluorine-based leveling agent (trade name "Megafuck F568", manufactured by DIC, solid content 5%) 300 parts by mass, photopolymerization initiator (trade name "Irgacure 127", BASF (Manufactured by) 8 parts by mass

[Example 8]
The same as in Example 1 except that the coating liquid for the layer containing the inorganic compound (low refractive index layer) was changed to the coating liquid for the layer containing the inorganic compound (low refractive index layer) of Example 8 below. A releasable laminate of 8 was obtained.
<Coating liquid for a layer (low refractive index layer) containing the inorganic compound of Example 8>
・ Silane coupling agent 1 (tetraethoxysilane) 25 parts by mass ・ Silane coupling agent 2 (3-methacryloxypropyltriemethoxysilane) 25 parts by mass ・ Pentaerythritol triacrylate 50 parts by mass ・ Hollow silica fine particle-containing dispersion ( Solid content 20%, average primary particle diameter 60 nm) 800 parts by mass, photopolymerization initiator (trade name "Irgacure 127", manufactured by BASF) 7 parts by mass, methylisobutylketone 9300 parts by mass, IPA 1100 parts by mass

[Example 9]
In the same manner as in Example 1, a hardcoat layer and a layer containing an inorganic compound were formed on a polyethylene terephthalate film (refractive index 1.65).
Next, after corona discharge treatment is performed on the surface of the layer containing the inorganic compound, the release layer coating liquid 2 of the above formulation is applied, dried (100 ° C. for 1 minute), and heat-treated at 110 ° C. for 15 minutes to cure the silica sol. After (dehydration condensation), it was irradiated with ultraviolet rays (200 mJ / cm ² ) to obtain a releasable laminate of Example 9. The theoretical thickness of the release layer based on the coating amount is 10 nm.
The coating liquid 2 for the release layer was formed to have a thickness at which the refractive index could be measured, and the refractive index was measured and found to be 1.43.

[Comparative Example 1]
A releasable laminate of Comparative Example 1 was obtained in the same manner as in Example 1 except that the releasable layer was not formed on the layer containing the inorganic compound.

[Reference Example 1]
A mold release laminate of Reference Example 1 was obtained in the same manner as in Example 1 except that a layer containing an inorganic compound was not formed on the hard coat layer and a mold release layer was directly formed on the hard coat layer. ..

As is clear from Table 1, the releasable laminates of Examples 1 to 9 have a predetermined adhesive force with respect to the adhesive, and the adhesive can be easily peeled off by a simple process of dropping water. , And it can be confirmed that the performance can be maintained for a long period of time. Although not evaluated in the table, the releasable laminate of Example 8 satisfied the condition 4 of the specification and was capable of sustaining the performance for an extremely long period of time.

10: Transparent plastic film 20: Hard coat layer 30: Layer containing an inorganic compound 40: Release layer 100: Releasable laminate

Claims (9)

A laminate having a release layer on a transparent plastic film, the release layer is located on the outermost surface of the laminate, and the following conditions 1 and 2 are satisfied, and the release layer has the following formula. A releasable laminate which is a cured product of a releasable layer forming composition containing a silica sol modified with the functional group shown in (II) .
(-O-) _3-k (R) _k Si-R ^1- (X-R ² ) _m - N ⁺ (R ³ ) (R ⁴ ) -R ⁵ - Y (II)
[In formula (II), R represents an alkyl group having 1 to 3 carbon atoms, k represents 0 or 1, R ¹ represents an alkylene group having 1 to 5 carbon atoms, and X represents -NHCOO-, -NHCONH. -Or -S-, m represents 0 or 1, R ² may contain an ether bond, an ester bond or an amide bond. An alkylene group having 1 to 10 carbon atoms or -CH ₂ CH ₂ N ⁺ (CH ₃ ). ) {(CH ₂ ) _n Y)} CH ₂ CH ₂ OCH ₂ CH _2- , n represents 0 or 1, and R ³ and R ⁴ are alkyl groups having 1 to 3 carbon atoms which may be the same or different. , R ⁵ represents a methylene group, an ethylene group, a propylene group or a methylene phenylene group, and Y represents ^{-COO- or} -SO _3- . ]
<Condition 1>
Prepare an adhesive tape A having a peel strength of PA (N / 10 mm) in Method 1 (180 ° peeling from a stainless steel test plate) of JIS Z0237: 2009. Adhesive tape A is attached to the surface of the releasable laminate on the release layer side, and the adhesive tape A conforms to Method 1 of JIS Z0237: 2009 except that the test plate is a releasable laminate instead of stainless steel. When the peel strength at the time of peeling is P1 (N / 10 mm), P1 / PA shows 0.75 or more.
<Condition 2>
Adhesive tape A is attached to the surface of the releasable laminate on the release layer side. Water is dropped with a dropper so that at least the area where the adhesive tape A is bonded and the area 1 cm outside the outer edge of the adhesive tape A are covered with water on the surface of the release layer on the release layer side. do. After 5 minutes have passed since the dripping of water was completed, the adhesive tape A was peeled off in accordance with Method 1 of JIS Z0237: 2009 except that the test plate was not stainless steel but a releasable laminate. When the intensity is P2 (N / 10 mm), P2 / PA is 0.2 or less. Further, the releasable laminate according to claim 1, which satisfies the following condition 3.
<Condition 3>
The surface of the release layer of the releasable laminate is rubbed 1000 times back and forth with a load of 500 g / cm ² using a 300-count cotton flannel cloth, and this is referred to as a friction laminate 1. The adhesive tape A is attached to the surface of the friction laminate 1 on the release layer side. Water is dropped with a dropper so that at least the area where the adhesive tape A is bonded and the area 1 cm outside the outer edge of the adhesive tape A on the surface of the friction laminate 1 on the release layer side are covered with water. .. After 5 minutes have passed since the dripping of water was completed, the peeling strength when the adhesive tape A was peeled off in accordance with Method 1 of JIS Z0237: 2009 except that the test plate was not stainless steel but a friction laminate 1. When P3 (N / 10 mm), P3 / PA is 0.2 or less. The releasable laminate according to claim 1 or 2, which has the releasable layer on both sides of the transparent plastic film. The releasable laminate according to any one of claims 1 to 3, wherein the releasable layer has a thickness of 1 to 25 nm. The releasable laminate according to any one of claims 1 to 4, which has a layer containing an inorganic compound between the transparent plastic film and the releasable layer. The releasable laminate according to any one of claims 1 to 5, which has a hard coat layer between the transparent plastic film and the releasable layer. A transfer sheet having a transfer layer on the release layer of the releasable laminate according to any one of claims 1 to 6. A process sheet having the release layer of the releasable laminate according to any one of claims 1 to 6 on the outermost surface. An article in which the release layer of the releasable laminate according to any one of claims 1 to 6 is arranged so as to face the surface.

Images