KR20230100756A - Laminate, optical member and optical device - Google Patents

Abstract

An object of the present invention is to provide a laminate of a void layer and an adhesive layer that achieves both adhesive strength or adhesive strength and difficulty in penetrating the pressure-sensitive adhesive or adhesive into the void.
In order to achieve the above object, the first laminate of the present invention includes an air gap layer 20 and an adhesive layer 30, and the adhesive layer 30 is directly applied to one or both surfaces of the air gap layer 20. laminated, the porosity of the porous layer 20 is 35% by volume or more, and after a heating and humidification durability test in which the temperature is 85° C. and the relative humidity is 85% for 500 h, the void remaining ratio of the porous layer 20 is It is characterized in that it is 50% by volume or more before the humidification durability test.

Description

Laminate, optical member and optical device {LAMINATE, OPTICAL MEMBER AND OPTICAL DEVICE}

The present invention relates to a laminate, an optical member and an optical device.

In an optical device, for example, an air layer having a low refractive index is used as a total reflection layer. Specifically, for example, each optical film member (for example, a light guide plate and a reflector) in a liquid crystal device is laminated through an air layer. However, when each member is separated by an air space, problems such as bending of the member may occur, particularly when the member is large. Moreover, integration of each member is desired by the trend of thinning of a device. For this reason, it is performed to integrate each member with an adhesive agent without intervening an air layer (patent document 1, for example). However, if the air layer that plays the role of total reflection disappears, there is a possibility that optical properties such as light leakage may deteriorate.

Therefore, it is proposed to use a low refractive index layer instead of an air layer. For example, Patent Document 2 describes a structure in which a layer having a lower refractive index than the light guide plate is inserted between the light guide plate and the reflector. As the low refractive index layer, for example, a void layer having voids is used in order to make the refractive index as low as possible close to that of air.

Japanese Unexamined Patent Publication No. 2012-156082 Japanese Unexamined Patent Publication No. 10-62626

The void layer is used, for example, laminated with another layer via an adhesive layer. However, when the void layer and the adhesive layer are laminated, the pressure-sensitive adhesive or adhesive constituting the adhesive layer penetrates into the void of the void layer, filling the void, and there is a risk that the porosity may decrease. And, the higher the porosity of the void layer, the easier it is for the pressure-sensitive adhesive or adhesive to permeate. Further, in a high-temperature environment, molecular motion of the pressure-sensitive adhesive or adhesive makes it easier for the pressure-sensitive adhesive or adhesive to permeate into the void.

In order to suppress or prevent the permeation of the pressure-sensitive adhesive or adhesive into the void, the pressure-sensitive adhesive or adhesive may be used as high as possible (hard) in elastic modulus. However, when the elastic modulus of the pressure-sensitive adhesive or adhesive is high (hard), there is a possibility that the adhesive strength or adhesive strength may decrease. Conversely, when the elastic modulus of the pressure-sensitive adhesive or adhesive is low (soft), high adhesive strength or adhesive strength is easily obtained, but there is a risk that the pressure-sensitive adhesive or adhesive easily penetrates the voids.

Therefore, an object of the present invention is to provide a laminate, an optical member, and an optical device of a void layer and an adhesive layer, which have both adhesive strength or adhesive strength and difficulty in penetrating the pressure-sensitive adhesive or adhesive into the void.

In order to achieve the above object, the first laminate of the present invention,

Including an air gap layer and an adhesive layer,

The point adhesive layer is directly laminated on one side or both sides of the air gap layer,

The porosity of the void layer is 35% by volume or more,

It is characterized in that, after a heating and humidification durability test maintained at a temperature of 85° C. and a relative humidity of 85% for 500 h, the void remaining ratio of the void layer is 50 volume% or more before the heating and humidification durability test.

The second laminate of the present invention,

Including an air gap layer and an adhesive layer,

The point adhesive layer is directly laminated on one side or both sides of the air gap layer,

The porosity of the void layer is 35% by volume or more,

The pressure-sensitive adhesive layer is formed by a pressure-sensitive adhesive containing a (meth)acrylic polymer and a crosslinking agent,

The gel fraction of the adhesive layer is 70% or more,

The thickness of the adhesive layer is 2 to 50 μm,

The adhesive layer is characterized in that it satisfies the following formula (I).

[(100 − X) / 100] × Y ≤ 10 (I)

In the formula (I),

X is the gel fraction (%) of the adhesive layer,

Y is the thickness (μm) of the adhesive layer.

The third laminate of the present invention,

Including an air gap layer and an adhesive layer,

The point adhesive layer is directly laminated on one side or both sides of the air gap layer,

The porosity of the void layer is 35% by volume or more,

The pressure-sensitive adhesive layer is formed by a pressure-sensitive adhesive containing a (meth)acrylic polymer and a crosslinking agent,

The (meth)acrylic polymer, as a monomer component, contains 3 to 10% by weight of a heterocyclic acrylic monomer, 0.5 to 5% by weight of (meth)acrylic acid, 0.05 to 2% by weight of hydroxyalkyl (meth)acrylate, and an alkyl ( It is characterized by being a (meth)acrylic polymer having a weight average molecular weight of 1,500,000 to 2,800,000 obtained by polymerizing 83 to 96.45% by weight of meth)acrylate. In addition, below, the 1st laminated body of this invention, the 2nd laminated body of this invention, and the 3rd laminated body of this invention may be collectively called "the laminated body of this invention."

An optical member of the present invention is an optical member comprising the laminate of the present invention described above.

An optical device of the present invention is an optical device including the optical member of the present invention.

According to the present invention, it is possible to provide a laminate, an optical member, and an optical device of a void layer and an adhesive layer, which have both adhesive strength or adhesive strength and difficulty in penetrating the pressure-sensitive adhesive or adhesive into the void.

1 schematically shows an example of a method for forming a laminate of the present invention in which a void layer 21, an intermediate layer 22, and an adhesive layer 30 are laminated on a resin film 10 in the present invention. It is a cross section of the process represented by .
2 : is a figure which shows typically one example of a part of the process in the manufacturing method of roll-shaped laminated|multilayer film (laminated film roll), and the apparatus used for it.
3 : is a figure which shows typically another example of a part of the process in the manufacturing method of a laminated film roll, and the apparatus used for it.

Next, the present invention will be described more specifically with examples. However, this invention is not limited at all by the following description.

In the first laminate of the present invention, for example, the void remaining ratio of the void layer after the heating and humidification durability test is 50% of the void remaining ratio when only the void layer is subjected to the heating and humidification durability test. More than % may be 99% or less.

The first laminate of the present invention, for example,

The void layer and the adhesive layer are laminated with an intermediate layer interposed therebetween,

The intermediate layer is a layer formed by combining a portion of the void layer and a portion of the adhesive layer,

The thickness of the intermediate layer is 200 nm or less,

After the heating and humidification durability test, the rate of increase in the thickness of the intermediate layer may be 500% or less of the thickness of the intermediate layer before the heating and humidification durability test.

As described above, in the second laminate of the present invention, the numerical value of [(100 - X) / 100] x Y represented by the formula (I) is 10 or less. This means that the amount of the component penetrating into the void layer in the adhesive layer is small. Accordingly, it is possible to suppress or prevent a phenomenon in which the voids of the void layer are filled and the porosity decreases. The gel fraction (X) of the pressure-sensitive adhesive is 70% or more as described above, and may be, for example, 75% or more or 80% or more. The upper limit of the gel fraction (X) is not particularly limited, but may be, for example, 100% or less, or 95% or less. The gel fraction (X) of the pressure-sensitive adhesive may be, for example, 75 to 95% or 80 to 95%. The thickness (Y) of the adhesive layer is, as described above, 2 to 50 μm, for example, 5 μm or more or 10 μm or more, for example, 40 μm or less or 30 μm or less. The thickness (Y) of the adhesive layer may be, for example, 5 to 40 µm or 10 to 30 µm.

In addition, although the measuring method of the gel fraction (X) of the said adhesive bonding layer is not specifically limited, For example, it can measure by the measuring method described in the Example mentioned later. In addition, although the measuring method of the thickness (Y) of the said adhesive bonding layer is not specifically limited, For example, it can be measured by the measuring method described in the Example mentioned later.

In the second laminate of the present invention, the gel fraction (X) of the adhesive layer, the thickness (Y) of the adhesive layer, and [(100 - X) / 100] × Y represented by the formula (I) By setting it as the above-mentioned specific range, it is possible to provide a layered product of a void layer and an adhesive layer, an optical member, and an optical device that have both adhesive strength or adhesive strength and difficulty in penetrating the pressure-sensitive adhesive into the void.

In the second laminate of the present invention, for example, in the molecular weight measurement of the adhesive layer by gel permeation chromatography method, the weight average molecular weight of the sol powder of the adhesive layer may be 50,000 to 500,000 . In addition, for example, in measuring the molecular weight of the adhesive layer by gel permeation chromatography, the content of low molecular weight components having a molecular weight of 10,000 or less in the sol powder of the adhesive layer is 20% by weight (mass% ) or less. By setting the weight average molecular weight of the sol powder or the content of the low molecular weight component having a molecular weight of 10,000 or less in the sol powder within the specific range, it is also difficult for the pressure-sensitive adhesive to permeate into the voids of the void layer. The weight average molecular weight of the sol powder may be, for example, 70,000 or more, eg, 450,000 or less, or 400,000 or less, for example, 70,000 to 450,000 or 7 to 400,000. In addition, the content (ratio) of the component having a molecular weight of 10,000 or less in the sol powder may be, for example, 20% by weight or less, for example, 15 It may be 10% by weight or less or 10% by weight or less. The lower limit of the content (proportion) of the component having a molecular weight of 10,000 or less in the sol powder is not particularly limited, but may be, for example, 0% by weight or more or a value exceeding 0% by weight, for example, 3% by weight or more. may be continued The content (ratio) of the component having a molecular weight of 10,000 or less in the sol powder may be, for example, 3 to 15% by weight or 3 to 10% by weight.

In addition, the specific measuring method by gel permeation chromatography method is not specifically limited, For example, the measuring method described in the Example mentioned later may be sufficient.

In the second or third laminate of the present invention, for example, after a heating and humidification durability test in which a temperature of 85 ° C. and a relative humidity of 85% are maintained for 500 h, the void remaining ratio of the void layer is, for example, the heat and humidification durability test 50 volume% or more of the previous may be sufficient. Further, in the second or third laminate of the present invention, for example, the void remaining ratio of the void layer after the heating and humidification durability test is higher than that of the case where only the void layer was subjected to the heating and humidification durability test. It may be more than 50% and 99% or less of the void residual ratio.

The second or third laminate of the present invention, for example,

The void layer and the adhesive layer are laminated with an intermediate layer interposed therebetween,

The intermediate layer is a layer formed by combining a portion of the void layer and a portion of the adhesive layer,

The thickness of the intermediate layer may be 200 nm or less.

In the second or third layered body of the present invention, for example, after a heating and humidification durability test in which a temperature of 85 ° C. and a relative humidity of 85% are maintained for 500 h, the rate of increase in the thickness of the intermediate layer before the heating and humidification durability test It may be 500% or less of the thickness of the intermediate layer.

In the laminate of the present invention, the refractive index of the void layer may be, for example, 1.25 or less.

In the laminate of the present invention, for example, the adhesive layer may be formed of an optical acrylic pressure-sensitive adhesive having a total light transmittance of 85% or more and a haze of 3% or less. In addition, the measurement of the total light transmittance and haze of the said adhesive layer can be performed by the same measuring method as the laminate or air gap layer mentioned later, for example.

In the laminate of the present invention, for example, the adhesive layer may have a storage modulus of 1.0 × 10 ⁵ or more at 23°C. In addition, the measuring method of the storage elastic modulus at 23 degreeC is not specifically limited, For example, it can measure by the measuring method described in the Example mentioned later.

In the second or third laminate of the present invention, the adhesive layer is formed of a pressure-sensitive adhesive containing a (meth)acrylic polymer and a crosslinking agent, as described above. In the adhesive layer, for example, the (meth)acrylic polymer may be crosslinked with the crosslinking agent to form a crosslinked structure.

In the laminate of the present invention, the reason (mechanism) for achieving both the adhesive strength or adhesive strength and the difficulty of penetrating the pressure-sensitive adhesive or adhesive into the void is considered, for example, as follows. For example, by forming an adhesive layer using a specific pressure-sensitive adhesive, it is possible to achieve both adhesive strength or adhesive strength and difficulty in penetrating the pressure-sensitive adhesive or adhesive into the void. More specifically, for example, by forming a pressure-sensitive adhesive layer using a specific pressure-sensitive adhesive as described above, an intermediate layer is formed by combining a part of the air gap layer and a part of the pressure-sensitive adhesive layer. In addition, by using the specific pressure-sensitive adhesive as described above, the intermediate layer is not excessively widened even under the same conditions as in the heat and humidification durability test. In addition, the intermediate layer serves as a stopper, and a decrease in porosity due to filling of voids in the void layer with an adhesive can be suppressed. Even if the molecular motion of the pressure-sensitive adhesive increases under heating, if the elastic modulus of the pressure-sensitive adhesive is high, the middle layer formed from the pressure-sensitive adhesive and the high void layer tends to become a strong and dense stopper, and the penetration of the pressure-sensitive adhesive into the high void layer is suppressed. However, these mechanisms are mere examples and do not limit the present invention in any way.

[One. Laminates, optical members and optical devices]

As described above, the laminate of the present invention includes a void layer and an adhesive layer, and the adhesive layer is directly laminated on one side or both surfaces of the void layer. In the present invention, the adhesive layer is “directly laminated” on the gap layer, the adhesive layer may be in direct contact with the gap layer, and the adhesive layer is laminated on the gap layer via the intermediate layer. There may be.

In the laminate of the present invention, after a heating and humidification durability test in which a temperature of 85° C. and a relative humidity of 85% are maintained for 500 h, the void remaining ratio of the void layer is, for example, 50 It may be 55 vol% or more, or 60 vol% or more, and the upper limit is not particularly limited, but is ideally 100 vol%, and may be 99 vol% or less, 98 vol% or less, or 95 vol% or less.

When the laminate of the present invention has the intermediate layer, as described above, for example, after a heating and humidification durability test in which a temperature of 85 ° C. and a relative humidity of 85% are maintained for 500 h, the increase rate of the thickness of the intermediate layer is the heating and humidification With respect to the thickness of the intermediate layer before the durability test, when the thickness of the intermediate layer before the heating and humidification durability test is 100%, it may be 500% or less. The rate of increase in the thickness of the middle layer after the heat and humidification durability test is, for example, 400% or less, It may be 350% or less, or 300% or less, for example, 100% or more, 110% or more, 120% or more, 130% or more, or 140% or more.

Further, in the laminate of the present invention, the void remaining ratio of the void layer after the heating and humidification durability test is, for example, as described above, the voids when only the void layer is subjected to the heating and humidification durability test It may be more than 50% and 99% or less of the residual rate, 53% or more, 55% or more, or 60% or more, or 98% or less, 97% or less, or 96% or less.

In the laminate of the present invention, for example, the laminate of the adhesive layer and the void layer or the laminate of the adhesive layer, the intermediate layer and the void layer may have a light transmittance of 80% or more. Moreover, the haze of the said laminated body may be 3 % or less, for example. The light transmittance may be, for example, 82% or more, 84% or more, 86% or more, or 88% or more, and the upper limit is not particularly limited, but is ideally 100%, for example, 95% or less , 92% or less, 91% or less, or 90% or less may be sufficient. The haze of the layered product can be measured, for example, by the same method as the measurement of the haze of the void layer described later. In addition, the said light transmittance is the transmittance|permeability of light with a wavelength of 550 nm, and can be measured with the following measuring method, for example.

(Measurement method of light transmittance)

Using a spectrophotometer U-4100 (trade name of Hitachi, Ltd.), the laminate is used as a sample to be measured. Then, the total light transmittance (light transmittance) of the sample when the total light transmittance of air is assumed to be 100% is measured. The value of the total light transmittance (light transmittance) is a measured value at a wavelength of 550 nm.

The laminate of the present invention, for example, the adhesive strength or adhesive strength of the pressure-sensitive adhesive layer, for example, 0.7 N / 25 mm or more, 0.8 N / 25 mm or more, 1.0 N / 25 mm or more, or 1.5 N / 25 mm or more mm or more, 50 N/25 mm or less, 30 N/25 mm or less, 10 N/25 mm or less, 5 N/25 mm or less, or 3 N/25 mm or less may be sufficient. From the viewpoint of peeling risk during handling when the laminate is bonded to other layers, it is preferable that the adhesive strength or adhesive strength of the adhesive layer is not too low. Moreover, it is preferable that the adhesive force or adhesive force of the said adhesive bonding layer is not too high from a viewpoint of rework at the time of reattachment. The adhesive force or adhesive force of the said adhesive bonding layer can be measured as follows, for example.

(Method of measuring adhesive force or adhesive force)

The laminated film of the present invention (a laminate of the present invention formed on a resin film substrate) was sampled in a 50 mm × 140 mm strip shape, and the sample was fixed to a stainless steel plate with double-sided tape let it An acrylic adhesive layer (thickness: 20 μm) was bonded to a PET film (T100: manufactured by Mitsubishi Resin Film Co., Ltd.), and an adhesive tape piece cut into 25 mm × 100 mm was mixed with the resin film in the laminated film of the present invention described above. It bonds to the opposite side and laminates with the said PET film. Next, after chucking the sample in an autograph tensile tester (manufactured by Shimadzu Corporation: AG-Xplus) so that the distance between chucks is 100 mm, a tensile test is performed at a tensile speed of 0.3 m/min. Let the average test force which performed the 50 mm peel test be the adhesive peel strength, ie, adhesive force. Moreover, adhesive force can also be measured by the same measuring method. In the present invention, there is no clear distinction between "adhesive force" and "adhesive force".

The laminate of the present invention may be formed on a substrate such as a film, for example. The film may be, for example, a resin film. In general, a relatively small thickness is called a "film" and a relatively large thickness is called a "sheet" in some cases, but in the present invention, there is no particular distinction between a "film" and a "sheet". .

The substrate is not particularly limited, and examples thereof include a substrate made of thermoplastic resin, a substrate made of glass, an inorganic substrate represented by silicon, a plastic molded with a thermosetting resin, etc., an element such as a semiconductor, and a carbon represented by carbon nanotube. Fiber-based materials and the like can be preferably used, but are not limited thereto. As for the form of the said base material, a film, a plate, etc. are mentioned, for example. The thermoplastic resin, for example, polyethylene terephthalate (PET), acrylic, cellulose acetate propionate (CAP), cycloolefin polymer (COP), triacetyl cellulose (TAC), polyethylene naphthalate (PEN), polyethylene ( PE), polypropylene (PP), and the like.

Although the optical member of this invention is not specifically limited, For example, the optical film containing the said laminated body of this invention may be sufficient.

The optical device (optical device) of the present invention is not particularly limited, and may be, for example, an image display device or a lighting device. As an image display device, a liquid crystal display, an organic EL (Electro Luminescence) display, a micro LED (Light Emitting Diode) display, etc. are mentioned, for example. As a lighting device, organic EL lighting etc. are mentioned, for example.

[2. void layer]

Hereinafter, the void layer (hereinafter sometimes referred to as "the void layer of the present invention") in the laminate of the present invention will be described with an example. However, the void layer of the present invention is not limited to this.

The void layer of the present invention may have, for example, a porosity of 35 vol% or more, and a peak pore size of 50 nm or less. However, this is an example, and the void layer of the present invention is not limited to this.

The porosity may be, for example, 35 vol% or more, 38 vol% or more, or 40 vol% or more, and may be 90 vol% or less, 80 vol% or less, or 75 vol% or less. The void layer of the present invention may be, for example, a high void layer having a porosity of 60% by volume or more.

The said porosity can be measured by the following measuring method, for example.

(Porosity measurement method)

If the layer to be measured for porosity is a single layer and only contains voids, the ratio (volume ratio) of the constituent materials of the layer to air is determined by a conventional method (for example, by measuring weight and volume to calculate density). Since it is possible to calculate, the porosity (volume %) can be calculated accordingly. Moreover, since a refractive index and a porosity have a correlation, a porosity can also be computed from the value of the refractive index as a layer, for example. Specifically, the porosity is calculated from the value of the refractive index measured with an ellipsometer, for example, from Lorentz-Lorenz's formula (Formula of Lorentz-Lorenz).

The void layer of the present invention can be produced, for example, by chemical bonding of pulverized gel (fine pore particles) as will be described later. In this case, the voids of the void layer can be divided into three types of the following (1) to (3) for convenience.

(1) Voids in the raw material gel itself (inside the particles)

(2) Porosity of the gel pulverized product unit

(3) Gaps between the pulverized materials caused by the deposition of the pulverized gel

The voids of (2) above are formed in each block when each particle group generated by crushing the gel is regarded as one lump (block), regardless of the size, size, etc. of the gel pulverized product (microporous particle). Apart from the above (1) that can be, it is a void formed during grinding. Further, the voids of (3) above are voids that are formed because the size, size, etc., of the gel pulverized product (microporous particles) become uneven during pulverization (eg, medialess pulverization). The void layer of the present invention has an appropriate porosity and peak pore diameter by having, for example, the voids of (1) to (3) above.

Further, the peak pore diameter may be, for example, 5 nm or more, 10 nm or more, or 20 nm or more, and may be 50 nm or less, 40 nm or less, or 30 nm or less. In the void layer, when the peak pore diameter is too large in a state where the porosity is high, light is scattered and becomes opaque. In the present invention, the lower limit of the peak pore diameter of the void layer is not particularly limited, but if the peak pore diameter is too small, it is difficult to increase the porosity, so it is preferable that the peak pore diameter is not too small. In the present invention, the peak pore diameter can be measured, for example, by the following method.

(Method of measuring peak pore size)

Using a pore distribution/specific surface area measuring device (BELLSORP MINI/Microtrak Bell Co., Ltd.), the peak pore diameter is calculated from the results of calculating the BJH plot and BET plot and isothermal adsorption lines by nitrogen adsorption.

Further, the thickness of the void layer of the present invention is not particularly limited, but may be, for example, 100 nm or more, 200 nm or more, or 300 nm or more, and may be 10000 nm or less, 5000 nm or less, or 2000 nm or less.

In the porous layer of the present invention, for example, as will be described later, by using pulverized porous gel, the three-dimensional structure of the porous gel is destroyed and a new three-dimensional structure different from that of the porous gel is formed. In this way, the void layer of the present invention is a layer formed with a new pore structure (new pore structure) that cannot be obtained in the layer formed from the porous gel, and a nanoscale void layer with a high porosity can be formed. Further, in the void layer of the present invention, for example, when the void layer is a silicon porous body, the pulverized materials are chemically bonded to each other while adjusting the number of siloxane bonding functional groups in the silicon compound gel, for example. In addition, since a new three-dimensional structure is formed as a precursor of the void layer and then chemically bonded (eg, cross-linked) in the bonding process, the void layer of the present invention, for example, when the void layer is a functional porous material, Although it has a structure with voids, sufficient strength and flexibility can be maintained. Therefore, according to the present invention, a void layer can be easily and conveniently applied to various objects.

As will be described later, the void layer of the present invention includes, for example, a pulverized porous gel, and the pulverized substances are chemically bonded to each other. In the porous layer of the present invention, the form of chemical bonding (chemical bonding) between the pulverized materials is not particularly limited, and specific examples of the chemical bonding include cross-linking and the like. In addition, the method of chemically bonding the pulverized materials to each other is as described in detail in, for example, the method of manufacturing the void layer described above.

The cross-linking is, for example, a siloxane bond. Examples of the siloxane bond include T2 bond, T3 bond, and T4 bond, which are shown below. When the silicone porous body of the present invention has siloxane bonds, it may have any one type of bond, any two types of bonds, or all three types of bonds, for example. Among the siloxane bonds, the higher the ratio of T2 and T3, the richer the flexibility and original properties of the gel can be expected, but the weaker the film strength. On the other hand, when the ratio of T4 among the siloxane bonds is high, film strength is easily developed, but the pore size is reduced and flexibility is weakened. For this reason, it is preferable to change the ratio of T2, T3 and T4 depending on the application, for example.

[Formula 1]

When the void layer of the present invention has the siloxane bond, the ratio of T2, T3 and T4 is, for example, when T2 is expressed as "1" relatively, T2: T3: T4 = 1: [1 to 100] : [0 to 50], 1: [1 to 80]: [1 to 40], 1: [5 to 60]: [1 to 30].

Further, in the void layer of the present invention, for example, it is preferable that silicon atoms contained therein are bonded to siloxane. As a specific example, the proportion of unbonded silicon atoms (ie, residual silanol) among all the silicon atoms contained in the silicon porous body is, for example, less than 50%, less than 30%, and less than 15%.

The void layer of the present invention has, for example, a hole structure. In the present invention, the pore size of a hole refers to the diameter of the major axis of the major axis diameter and the minor axis diameter of the void (hole). The pore size is, for example, 5 nm to 50 nm. The pore size has a lower limit of, for example, 5 nm or more, 10 nm or more, or 20 nm or more, and an upper limit thereof, for example, 50 nm or less, 40 nm or less, or 30 nm or less, and the range is , for example, 5 nm to 50 nm and 10 nm to 40 nm. Since a preferable pore size is determined depending on the use of the pore structure, the pore size needs to be adjusted to a desired pore size depending on the purpose, for example. The void size can be evaluated, for example, by the following method.

(Cross-section SEM observation of void layer)

In the present invention, the shape of the void layer can be observed and analyzed using a scanning electron microscope (SEM). Specifically, for example, the void layer was subjected to FIB processing under cooling (acceleration voltage: 30 kV), and the obtained cross-sectional sample was subjected to FIB-SEM (manufactured by FEI: trade name Helios NanoLab600, acceleration voltage: 1 kV). , cross-sectional electron images can be obtained at an observation magnification of 100,000 times.

(Evaluation of pore size)

In the present invention, the pore size can be quantified by the BET test method. Specifically, 0.1 g of the sample (void layer of the present invention) was put into the capillary of a pore distribution/specific surface area measuring device (trade name of BELLSORP MINI/Microtrac Bell Co., Ltd.), followed by drying at room temperature for 24 hours under reduced pressure. Thus, the gas in the pore structure is degassed. Then, by adsorbing nitrogen gas to the sample, a BET plot, a BJH plot, and an adsorption isotherm are drawn to obtain a pore distribution. Accordingly, the pore size can be evaluated.

In the void layer of the present invention, the film density representing the porosity is not particularly limited, and the lower limit thereof is, for example, 1 g/cm 3 or more, 5 g/cm 3 or more, 10 g/cm 3 or more, or 15 g/cm 3 or more, and the upper limit thereof is, for example, 50 g/cm 3 or less, 40 g/cm 3 or less, 30 g/cm 3 or less, 2.1 g/cm 3 or less, and the range is, for example, 5 to 50 g/cm 3 , 10 to 40 g/cm 3 , 15 to 30 g/cm 3 , and 1 to 2.1 g/cm 3 .

The said film density can be measured by the following method, for example.

(Evaluation of membrane density)

After the void layer (void layer of the present invention) was formed on the acrylic film, the X-ray reflectance of the total reflection region was measured using an X-ray diffractometer (RINT-2000 manufactured by RIGAKU). After fitting the intensity and 2θ, the porosity (P%) is calculated from the critical angle of total reflection of the void layer/substrate. The film density can be expressed by the following formula.

Film Density (%) = 100 (%) - Porosity (P %)

The void layer of the present invention may have, for example, a pore structure (porous structure) as described above, or may be, for example, an open fabric structure in which the pore structure is continuous. The above-mentioned soft fabric structure means, for example, that the pore structure is connected three-dimensionally in the void layer, and it can also be said that the state in which the internal voids of the pore structure are continuous. When the porous body has a cell structure, it is possible to increase the porosity occupied in the bulk by this, but when using single cell particles such as hollow silica, the cell structure cannot be formed. On the other hand, in the void layer of the present invention, since the sol particles (the pulverized porous gel forming the sol) have a three-dimensional dendritic structure, the coated film (the sol containing the pulverized porous gel) Coated film), it is possible to form a connected cell structure easily by sedimentation and deposition of the water phase particles. Moreover, it is preferable that the void layer of this invention forms the monolith structure in which the open cell structure has several pore distribution more preferably. The monolith structure refers to, for example, a structure in which nano-sized fine voids exist and a hierarchical structure in which the same nano-voids are aggregated as a connected cell structure. In the case of forming the monolith structure, it is possible to achieve both film strength and high porosity by, for example, imparting a high porosity to coarse open pores while imparting film strength to fine pores. In order to form these monolith structures, it is important to first control the pore distribution of the pore structure to be formed in the porous gel prior to pulverization into the pulverized material, for example. Further, for example, when the porous gel is pulverized, the monolith structure can be formed by controlling the particle size distribution of the pulverized material to a desired size.

In the void layer of the present invention, the haze exhibiting transparency is not particularly limited, and the lower limit is, for example, 0.1% or more, 0.2% or more, or 0.3% or more, and the upper limit is, for example, 10%. Below, it is 5 % or less and 3 % or less, and the range is 0.1 to 10 %, 0.2 to 5 %, and 0.3 to 3 %, for example.

The said haze can be measured by the following methods, for example.

(Haze's evaluation)

The void layer (void layer of the present invention) is cut to a size of 50 mm x 50 mm, set in a haze meter (HM-150 manufactured by Murakami Color Technology Research Institute), and the haze is measured. About haze value, it calculates from the following formula.

Haze (%) = [diffuse transmittance (%) / total light transmittance (%)] x 100 (%)

Regarding the refractive index, the ratio between the propagation speed of the wavefront of light in a vacuum and the propagation speed in the medium is generally referred to as the refractive index of the medium. The refractive index of the void layer of the present invention is not particularly limited, and the upper limit thereof is, for example, 1.3 or less, less than 1.3, 1.25 or less, 1.2 or less, or 1.15 or less, and the lower limit is, for example, 1.05 or more, 1.06 or less. or more, 1.07 or more, and the ranges are, for example, 1.05 or more and 1.3 or less, 1.05 or more and less than 1.3, 1.05 or more and 1.25 or less, 1.06 or more and less than 1.2, and 1.07 or more and 1.15 or less.

In the present invention, the refractive index refers to a refractive index measured at a wavelength of 550 nm unless otherwise specified. In addition, the measuring method of refractive index is not specifically limited, For example, it can measure by the following method.

(Evaluation of refractive index)

After forming the void layer (void layer of the present invention) on the acrylic film, it is cut into a size of 50 mm × 50 mm, and this is bonded to the surface of a glass plate (thickness: 3 mm) with an adhesive layer. The center portion (about 20 mm in diameter) of the back surface of the glass plate was completely coated with black ink to prepare a sample that did not reflect on the back surface of the glass plate. The sample is set in an ellipsometer (manufactured by J. A. Woollam Japan: VASE), and the refractive index is measured under the conditions of a wavelength of 500 nm and an incident angle of 50 to 80 degrees, and the average value is taken as the refractive index.

The thickness of the void layer of the present invention is not particularly limited, and the lower limit is, for example, 0.05 μm or more and 0.1 μm or more, and the upper limit is, for example, 1000 μm or less and 100 μm or less, the range is, for example, 0.05 to 1000 μm or 0.1 to 100 μm.

The shape of the void layer of the present invention is not particularly limited, and may be, for example, a film shape or a block shape.

The manufacturing method of the void layer of the present invention is not particularly limited, but it can be manufactured, for example, by a manufacturing method described later.

[3. adhesive]

In the laminate of the present invention, the adhesive layer may be formed using, for example, at least one of a pressure-sensitive adhesive and an adhesive. In the present invention, "adhesive" and "adhesive" are not necessarily clearly distinguishable, as will be described later. Although it does not specifically limit as said adhesive, For example, the adhesive illustrated below is mentioned.

The pressure-sensitive adhesive used for formation of the pressure-sensitive adhesive layer in the layered product of the present invention has, for example, 3 to 10% by weight of a heterocyclic-containing acrylic monomer and a polymerizable functional group as a monomer component, and 0.5 to 0.5 to (meth)acrylic acid A (meth)acrylic polymer containing 5% by weight, 0.05 to 2% by weight of hydroxyalkyl (meth)acrylate, and 83 to 96.45% by weight of alkyl (meth)acrylate is used as the base polymer.

As the heterocycle-containing acrylic monomer, for example, one having a polymerizable functional group and a heterocyclic ring can be used without particular limitation. A (meth)acryloyl group, a vinyl ether group, etc. are mentioned as a polymerizable functional group. Among these, a (meth)acryloyl group is suitable. A morpholine ring, a piperidine ring, a pyrrolidine ring, a piperazine ring etc. are mentioned as a heterocyclic ring. As a heterocyclic containing acrylic monomer, N-acryloyl morpholine, N-acryloyl piperidine, N-methacryloyl piperidine, N-acryloyl pyrrolidine etc. are mentioned, for example. Among these, N-acryloylmorpholine is suitable. In addition, the heterocycle-containing acrylic monomer can improve either durability of heat resistance or moisture resistance when the pressure-sensitive adhesive layer is reduced in thickness.

Moreover, the heterocyclic containing acrylic monomer is preferable at the point which can improve the adhesive force with respect to the optical film of an adhesive layer. In particular, it is preferable at the point of improving the adhesive force with respect to cyclic polyolefin, such as norbornene-type resin, and is suitable when using cyclic polyolefin as an optical film.

The heterocycle-containing acrylic monomer is used, for example, in an amount of 3 to 10% by weight relative to the total amount of the monomer components forming the (meth)acrylic polymer. The ratio of the heterocyclic containing acrylic monomer may be, for example, 4 to 9.5% by weight or 6 to 9% by weight. It is preferable that the proportion of the heterocyclic-containing acrylic monomer is not less than the above range from the viewpoint of heat resistance and moisture resistance when the pressure-sensitive adhesive layer is reduced in thickness. Moreover, it is preferable that the ratio of a heterocyclic containing acrylic monomer is not more than the said range from a viewpoint of moisture resistance at the time of thinning. Moreover, it is preferable that the ratio of a heterocyclic containing acrylic monomer does not exceed the said range from a viewpoint of improving the adhesiveness of an adhesive layer. Moreover, it is preferable that the ratio of a heterocyclic containing acrylic monomer is not more than the said range from a viewpoint of adhesive force.

As (meth)acrylic acid, acrylic acid is especially preferable.

(Meth)acrylic acid is used, for example, in a proportion of 0.5 to 5% by weight based on the total amount of the monomer components forming the (meth)acrylic polymer. The ratio of (meth)acrylic acid may be, for example, 1 to 4.5% by weight or 1.5 to 4% by weight. It is preferable that the ratio of (meth)acrylic acid is not less than the said range from a viewpoint of heat resistance at the time of thinning an adhesive layer (adhesive adhesive layer). Moreover, it is preferable that the ratio of (meth)acrylic acid is not more than the said range from a viewpoint of heat resistance and moisture resistance at the time of thinning. Moreover, it is preferable that the ratio of (meth)acrylic acid is not more than the said range from a viewpoint of adhesive force.

As a hydroxyalkyl (meth)acrylate, what has a polymerizable functional group and a hydroxyl group can be used without particular limitation, for example. As hydroxyalkyl (meth)acrylate, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4- Hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate Hydroxyalkyl (meth)acrylates such as )acrylates are suitable.

Hydroxyalkyl (meth)acrylate is used, for example, in an amount of 0.05 to 2% by weight with respect to the total amount of the monomer components forming the (meth)acrylic polymer. The ratio of hydroxyalkyl (meth)acrylate may be, for example, 0.075 to 1.5% by weight or 0.1 to 1% by weight. It is preferable that the ratio of hydroxyalkyl (meth)acrylate is not less than the said range from a viewpoint of heat resistance at the time of thinning an adhesive layer (adhesive adhesive layer). Moreover, it is preferable that the ratio of hydroxyalkyl (meth)acrylate is not more than the said range from a viewpoint of heat resistance and moisture resistance at the time of thinning. Moreover, it is preferable that the ratio of hydroxyalkyl (meth)acrylate is not more than the said range from a viewpoint of adhesive force.

As an alkyl (meth)acrylate, the average number of carbon atoms of the alkyl group of an alkyl (meth)acrylate may be about 1-12, for example. Incidentally, (meth)acrylate refers to acrylate and/or methacrylate, and has the same meaning as (meth) in the present invention. Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) Acrylate, isononyl (meth)acrylate, lauryl (meth)acrylate and the like can be exemplified, and these can be used alone or in combination. Among these, the C1-C9 alkyl (meth)acrylate of an alkyl group is preferable.

The alkyl (meth)acrylate is used in an amount of 83 to 96.45% by weight based on the total amount of the monomer components forming the (meth)acrylic polymer, for example. The alkyl (meth)acrylate is usually a remainder other than the heterocyclic containing acrylic monomer, (meth)acrylic acid and hydroxyalkyl (meth)acrylate.

As the monomer components forming the (meth)acrylic polymer, for example, in addition to the above monomers, any monomers other than the above may be used in an amount of 10% or less of the total amount of the monomers, within a range that does not impair the object of the present invention. can be used

Examples of the optional monomer include acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; Contains sulfonic acid groups such as styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, sulfopropyl(meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid monomer; Phosphoric acid group containing monomers, such as 2-hydroxyethyl acryloyl phosphate, etc. are mentioned. and nitrogen-containing vinyl monomers. For example, maleimide, N-cyclohexyl maleimide, N-phenyl maleimide; (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-methyl(meth)acrylamide, N-butyl (N-substituted) amide-based monomers such as (meth)acrylamide, N-butyl (meth)acrylamide, N-methylol (meth)acrylamide, and N-methylolpropane (meth)acrylamide; Aminoethyl (meth)acrylate, aminopropyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, 3-(3-pyrinidyl)propyl (meth)acrylate (meth)acrylic acid alkylaminoalkyl type monomers such as the like; alkoxyalkyl (meth)acrylate monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, N-(meth)acryloyl-8-oxyoctamethylenesuccinimide, etc. A succinimide type monomer etc. are mentioned.

In addition, vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole vinyl monomers such as vinyl morpholine, N-vinyl carboxylic acid amides, styrene, α-methyl styrene, and N-vinyl caprolactam; cyanoacrylate-based monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth)acrylate; glycol-based acrylic ester monomers such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; Acrylic acid ester type monomers, such as tetrahydrofurfuryl (meth)acrylate, fluorine (meth)acrylate, silicone (meth)acrylate, and 2-methoxyethyl acrylate, etc. can also be used.

Moreover, as a monomer which can be copolymerized other than the above, the silane type monomer containing a silicon atom etc. are mentioned. Examples of the silane-based monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxide Syltriethoxysilane, 10-acryloyloxydecyltriethoxysilane, etc. are mentioned.

The (meth)acrylic polymer used in the present invention may have, for example, a weight average molecular weight of 1,500,000 to 2,800,000. The said weight average molecular weight may be 1.7 million - 2.7 million, or 2 million - 2.5 million, for example. It is preferable that the said weight average molecular weight is not smaller than the said range from a viewpoint of heat resistance and moisture resistance at the time of thinning an adhesive layer. Moreover, it is preferable that the said weight average molecular weight is not larger than the said range from a viewpoint of the said durability at the time of thinning, adhesiveness, and adhesive force. In addition, in this invention, a weight average molecular weight means the value calculated by measuring by GPC (gel permeation chromatography) and calculated by polystyrene conversion, for example.

The manufacturing method of such a (meth)acrylic-type polymer is not specifically limited, For example, well-known manufacturing methods, such as solution polymerization, bulk polymerization, emulsion polymerization, and various radical polymerization, can be selected suitably. Moreover, any of a random copolymer, a block copolymer, a graft copolymer, etc. may be sufficient as the obtained (meth)acrylic polymer.

In addition, in solution polymerization, ethyl acetate, toluene, etc. are used as a polymerization solvent, for example. As a specific example of solution polymerization, the reaction is carried out under an inert gas stream such as nitrogen, adding a polymerization initiator, and under reaction conditions, for example, at about 50 to 70°C for about 5 to 30 hours.

The polymerization initiator, chain transfer agent, emulsifier and the like used in radical polymerization are not particularly limited and can be appropriately selected and used. In addition, the weight average molecular weight of a (meth)acrylic polymer can be controlled by the usage amount of a polymerization initiator and a chain transfer agent, and reaction conditions, and the usage amount is adjusted suitably according to these types.

Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-amidinopropane)dihydrochloride, and 2,2'-azobis[2-( 5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (N, N' Azo initiators such as -dimethyleneisobutylamidine) and 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate (VA-057 manufactured by Wako Pure Chemical Industries, Ltd.); Persulfates such as potassium persulfate and ammonium persulfate, di(2-ethylhexyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylper Oxineodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy -2-ethylhexanoate, di(4-methylbenzoyl)peroxide, dibenzoylperoxide, t-butylperoxyisobutyrate, 1,1-di(t-hexylperoxy)cyclohexane, t-butylhydride peroxide-based initiators such as roperoxide and hydrogen peroxide, redox-based initiators combining a peroxide and a reducing agent, such as a combination of a persulfate and sodium bisulfite, a combination of a peroxide and sodium ascorbate, and the like, but are not limited thereto. .

The said polymerization initiator may be used independently, and may mix and use 2 or more types. The content of the polymerization initiator as a whole may be, for example, about 0.005 to 1 part by weight or about 0.02 to 0.5 part by weight with respect to 100 parts by weight of the monomer.

In addition, in order to produce a (meth)acrylic polymer of the above weight average molecular weight using, for example, 2,2'-azobisisobutyronitrile as a polymerization initiator, the usage amount of the polymerization initiator is the total amount of the monomer components. For 100 parts by weight, it may be, for example, about 0.06 to 0.2 parts by weight or about 0.08 to 0.175 parts by weight.

As a chain transfer agent, for example, lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, thioglucolic acid 2-ethylhexyl, 2,3-dimercapto- 1-propanol etc. are mentioned. A chain transfer agent may be used independently, and may mix and use 2 or more types. The overall content of the chain transfer agent is, for example, about 0.1 part by weight or less with respect to 100 parts by weight of the total amount of the monomer component.

In addition, as an emulsifier used in the case of emulsion polymerization, for example, sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, polyoxyethylene alkyl ether ammonium sulfate, polyoxyethylene alkyl phenyl ether sodium sulfate, etc. and nonionic emulsifiers such as ionic emulsifiers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters, and polyoxyethylene-polyoxypropylene block polymers. These emulsifiers may be used independently or may use 2 or more types together.

In addition, as a reactive emulsifier, as an emulsifier into which a radical polymerizable functional group such as a propenyl group or an allyl ether group is introduced, specifically, for example, Aqualon HS-10, HS-20, KH-10, BC-05, BC-10, BC-20 (above, all manufactured by Dai-ichi Kogyo Pharmaceutical Co., Ltd.), Adeka Ria Sof SE10N (manufactured by Asahi Denka Corporation), and the like. Reactive emulsifiers are preferred because they are introduced into the polymer chain after polymerization and thus have good water resistance. The amount of the emulsifier used is more preferably 0.3 to 5 parts by weight, and 0.5 to 1 part by weight based on 100 parts by weight of the total amount of the monomer components, from the viewpoint of polymerization stability and mechanical stability.

Moreover, it is preferable to use the said adhesive as the adhesive composition containing a crosslinking agent. Examples of polyfunctional compounds that can be incorporated into the pressure-sensitive adhesive include organic crosslinking agents and polyfunctional metal chelates. Examples of the organic crosslinking agent include an epoxy crosslinking agent, an isocyanate crosslinking agent, and an imine crosslinking agent. As the organic crosslinking agent, an isocyanate crosslinking agent is preferable. A polyfunctional metal chelate is one in which a multivalent metal is bonded covalently or coordinately to an organic compound. Examples of the multivalent metal atom include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. there is. Examples of atoms in organic compounds that form covalent bonds or coordinate bonds include oxygen atoms, and examples of organic compounds include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds.

Examples of the isocyanate-based crosslinking agent include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate.

More specifically, for example, lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate, alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate, 2,4 -Aromatic diisocyanates such as tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, and polymethylene polyphenyl isocyanate, trimethylolpropane/tolylene diisocyanate trimer adducts (manufactured by Nippon Polyurethane Industry Co., Ltd.) , trade name Colonate L), trimethylolpropane/hexamethylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry, trade name Colonate HL), isocyanurate of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry, trade name Isocyanate adducts such as Colonate HX), polyether polyisocyanates, polyester polyisocyanates, and adducts of these with various polyols, polyisocyanates polyisocyanates polyfunctionalized with isocyanurate bonds, biuret bonds, allophanate bonds, etc. etc. can be mentioned.

Although the said isocyanate-type crosslinking agent may be used independently or may mix and use 2 or more types, the total content of the said isocyanate-type crosslinking agent with respect to 100 mass parts of said (meth)acrylic-type polymers is, for example, 0.02 You may contain - 2 mass parts, 0.04 - 1.5 mass parts, or 0.05 - 1 mass part. The content of the isocyanate-based crosslinking agent is preferably 0.02 parts by mass or more from the viewpoint of cohesive strength, and preferably 2 parts by mass or less from the viewpoint of suppressing or preventing a decrease in adhesive strength due to excessive crosslinking.

Further, in the above-mentioned pressure-sensitive adhesive, if necessary, a tackifier, a plasticizer, a filler composed of glass fibers, glass beads, metal powder, other inorganic powder, etc., a pigment, a colorant, a filler, an antioxidant, an ultraviolet absorber, a silane coupling agent etc., and various additives may be appropriately used within a range not departing from the purpose of the present invention. Moreover, it is good also as an adhesive layer etc. which contain microparticles|fine-particles and show light diffusivity.

[4. Manufacturing method of laminated body]

Although the manufacturing method of the laminated body of this invention is not specifically limited, For example, it can be implemented by the manufacturing method demonstrated below. However, the following description is an example and does not limit the present invention in any way. In addition, below, the void layer which is a component of the laminate of the present invention is sometimes referred to as the “void layer of the present invention”. In addition, the method for manufacturing the void layer of the present invention is sometimes referred to as "the manufacturing method for the void layer of the present invention".

[4-1. Manufacturing method of void layer]

Hereinafter, the manufacturing method of the void layer of this invention is demonstrated by giving an example. However, the manufacturing method of the void layer of this invention is not limited at all by the following description.

The void layer of the present invention may be formed of, for example, a silicon compound. Further, the void layer of the present invention may be, for example, a void layer formed by chemical bonding between fine pore particles. For example, the microporous particles may be pulverized gel.

In the manufacturing method of the void layer of the present invention, for example, the gel crushing step for crushing the gel of the porous body may be one step, but is preferably divided into a plurality of crushing steps. The number of grinding stages is not particularly limited, and may be, for example, two stages or three or more stages.

In the present invention, the shape of the "particles" (eg, particles of the pulverized product of the gel) is not particularly limited, and may be, for example, spherical or non-spherical. In the present invention, the particles of the pulverized product may be, for example, sol-gel beaded particles, nanoparticles (hollow nanosilica/nanoballoon particles), nanofibers, and the like.

In the present invention, for example, it is preferable that the gel is a porous gel, and it is preferable that the pulverized product of the gel is porous, but it is not limited thereto.

In the present invention, the pulverized gel may have a structure having at least one of, for example, particulate, fibrous, and flat plates. The particulate and flat structural units may be made of, for example, an inorganic material. Further, the constituent element of the particulate structural unit may contain at least one element selected from the group consisting of, for example, Si, Mg, Al, Ti, Zn, and Zr. The structure (structural unit) that forms the particulate form may be real particles or hollow particles, and specifically includes silicon particles, silicon particles having micropores, silica hollow nanoparticles, silica hollow nanoballoons, and the like. . The fibrous constitutional unit is, for example, a nanofiber having a nano size in diameter, and specific examples thereof include cellulose nanofibers and alumina nanofibers. Examples of the flat structural unit include nanoclay, and specifically, nano-sized bentonite (eg, Cunipier F [trade name]) and the like. The fibrous structural unit is not particularly limited, but includes, for example, carbon nanofibers, cellulose nanofibers, alumina nanofibers, chitin nanofibers, chitosan nanofibers, polymer nanofibers, glass nanofibers, and silica nanofibers. It may be at least one fibrous substance selected from the group.

In the manufacturing method of the void layer of the present invention, the gel grinding step (eg, the plurality of grinding steps, for example, the first grinding step and the second grinding step), for example, You may carry out in "another solvent". Incidentally, details of the above "other solvent" will be described later.

In the present invention, the "solvent" (for example, a solvent for producing a gel, a solvent for forming a void layer, a solvent for substitution, etc.) does not have to dissolve the gel or its pulverized product, etc., and, for example, the gel or The pulverized material or the like may be dispersed or precipitated in the solvent.

The volume average particle size of the gel after the first grinding step may be, for example, 0.5 to 100 μm, 1 to 100 μm, 1 to 50 μm, 2 to 20 μm, or 3 to 10 μm. The volume average particle diameter of the gel after the second grinding step may be, for example, 10 to 1000 nm, 100 to 500 nm, or 200 to 300 nm. The volume average particle size indicates the particle size variation of the pulverized material in the gel-containing liquid (gel-containing liquid). The volume average particle size can be measured by, for example, a particle size distribution evaluation device such as a dynamic light scattering method or a laser diffraction method, and an electron microscope such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM). .

The method for producing a void layer of the present invention includes, for example, a gelation step of gelling a bulky porous body in a solvent to obtain the gel. In this case, for example, in the first grinding step (for example, the first grinding step) of the plurality of grinding steps, the gel gelled by the gelation step is used.

The manufacturing method of the void layer of the present invention includes, for example, an aging step of aging the gelated gel in a solvent. In this case, for example, in the first grinding step (eg, the first grinding step) of the plurality of grinding steps, the gel after the aging step is used.

In the manufacturing method of the void layer of the present invention, for example, after the gelation step, the solvent replacement step of substituting the solvent with another solvent is performed. In this case, for example, in the first grinding step (eg, the first grinding step) of the plurality of grinding steps, the gel in the other solvent is used.

In at least one of the plurality of pulverization steps of the method for producing a void layer of the present invention (eg, at least one of the first pulverization step and the second pulverization step), for example, the shear viscosity of the liquid While measuring the pulverization of the porous body is controlled.

At least one of the plurality of grinding steps (for example, at least one of the first grinding step and the second grinding step) of the method for producing a porous layer of the present invention is subjected to, for example, high-pressure medialess grinding. Conduct.

In the manufacturing method of the void layer of the present invention, the gel is, for example, a gel of a silicon compound containing at least a trifunctional or less saturated bonding functional group.

In the following, in the method for producing a void layer of the present invention, a pulverized gel-containing liquid obtained by a step including the gel pulverization step may be referred to as "the pulverized gel-containing liquid of the present invention".

According to the pulverized gel-containing liquid of the present invention, for example, the void layer of the present invention as a functional porous body can be formed by forming a coating film and chemically bonding the pulverized materials in the coating film to each other. According to the gel pulverized product-containing liquid of the present invention, for example, the void layer of the present invention can be applied to various objects. Therefore, the pulverized gel-containing liquid and the manufacturing method thereof of the present invention are useful, for example, in the production of the void layer of the present invention described above.

Since the gel pulverized liquid-containing liquid of the present invention has, for example, excellent uniformity, for example, when the void layer of the present invention is applied to applications such as optical members, its appearance can be improved. there is.

The pulverized gel-containing liquid of the present invention is a pulverized gel material for obtaining a layer (void layer) having a high porosity by, for example, coating (coating) the pulverized gel-containing liquid on a substrate and then drying it. It may be a containing liquid. Further, the pulverized gel-containing liquid of the present invention may be, for example, a pulverized gel-containing liquid for obtaining a high porosity porous body (thick or massive bulk body). The bulk body can be obtained, for example, by carrying out bulk film formation using the gel pulverized product-containing liquid.

For example, in the manufacturing method including the step of producing the pulverized gel-containing liquid of the present invention, the step of coating the pulverized gel-containing liquid on a substrate to form a coated film, and the step of drying the coated film. As a result, the void layer of the present invention having a high porosity can be produced.

Further, for example, the process of producing the liquid containing pulverized gel of the present invention, the process of dispensing the roll-shaped resin film, and coating the liquid containing pulverized gel on the discharged resin film to form a coated film. By a manufacturing method including a step of drying the coating film, and a step of winding up the laminated film in which the void layer of the present invention is formed on the resin film after the drying step, for example, as described later As shown in Figs. 2 and 3, a roll-shaped laminated film (laminated film roll) can be produced.

[4-2. Gel pulverized product-containing liquid and method for producing the same]

The pulverized gel-containing liquid of the present invention includes, for example, the pulverized gel pulverized by the gel pulverization process (eg, the first pulverization step and the second pulverization step) and the other solvent. do.

The manufacturing method of the void layer of the present invention, for example, as described above, may include a plurality of steps of a gel crushing step for crushing the gel (for example, porous gel), and, for example, the above You may include one grinding step and the said 2nd grinding step. Hereinafter, a case in which the method for producing a liquid containing a pulverized gel of the present invention includes the first pulverization step and the second pulverization step will be mainly described as an example. Hereinafter, the case where the gel is a porous body (porous gel) will be mainly described. However, the present invention is not limited to this, and the explanation can be analogically applied to the case where the gel is a porous body (porous gel) other than the case where the gel is a porous body. Hereinafter, the plurality of grinding steps (for example, the first grinding step and the second grinding step) in the method for producing a void layer of the present invention may be collectively referred to as a "gel grinding step".

The pulverized gel-containing liquid of the present invention can be used, for example, to produce a functional porous body that exhibits the same function as that of the air layer (eg, low refractive index), as will be described later. The functional porous body may be, for example, the void layer of the present invention. Specifically, the pulverized gel-containing liquid obtained by the production method of the present invention contains a pulverized product of the porous gel, and the pulverized product has the three-dimensional structure of the unpulverized porous gel destroyed and the pulverized porous gel. A new three-dimensional structure different from that of the porous gel can be formed. For this reason, for example, a coating film (precursor of a functional porous body) formed using the above-mentioned pulverized gel material-containing liquid has a new pore structure (new void structure) that cannot be obtained in a layer formed using the above-mentioned unpulverized porous gel. structure) is formed. Accordingly, the layer can exhibit the same function as the air layer (for example, the same low refractive index). Further, in the gel pulverized liquid-containing liquid of the present invention, after a new three-dimensional structure is formed as the coating film (precursor of a functional porous body) because the pulverized material contains residual silanol groups, the pulverized materials are chemically treated with each other. can be combined with Thus, the formed functional porous body has a structure with voids, but can maintain sufficient strength and flexibility. For this reason, according to the present invention, functional porous bodies can be easily and conveniently applied to various objects. The pulverized gel-containing liquid obtained by the production method of the present invention is very useful in the production of the porous structure, which can be used as a substitute for an air layer, for example. In addition, in the case of the air layer, it is necessary to form an air layer between the members by, for example, stacking the members with a gap formed by interposing a spacer or the like between the members. However, the functional porous body formed using the gel pulverized product-containing liquid of the present invention can exhibit the same function as the air layer just by disposing it at the target site. Therefore, as described above, the same functions as those of the air layer can be imparted to various objects more easily and simply than forming the air layer.

The liquid containing the pulverized gel of the present invention can also be referred to as, for example, a solution for forming the functional porous body or a solution for forming a void layer or a low refractive index layer. In the gel pulverized product-containing liquid of the present invention, the porous body is a pulverized product.

In the liquid containing pulverized gel of the present invention, the range of the volume average particle diameter of the pulverized material (particles of porous gel) is, for example, 10 to 1000 nm, 100 to 500 nm, and 200 to 300 nm. The volume average particle diameter indicates the particle size variation of the pulverized material in the liquid containing the pulverized gel of the present invention. As described above, the volume average particle diameter is determined by, for example, a particle size distribution evaluation device such as a dynamic light scattering method and a laser diffraction method, and an electron microscope such as a scanning electron microscope (SEM) and a transmission electron microscope (TEM). can be measured by

In addition, in the liquid containing pulverized gel of the present invention, the gel concentration of the pulverized product is not particularly limited. For example, particles having a particle size of 10 to 1000 nm are 2.5 to 4.5% by weight, 2.7 to 4.0% by weight, It is 2.8-3.2 weight%.

In the gel pulverized product-containing liquid of the present invention, the gel (eg, porous gel) is not particularly limited, and examples thereof include silicon compounds and the like.

The silicon compound is not particularly limited, and examples thereof include silicon compounds containing at least trifunctional or less saturated bonding functional groups. "Containing trifunctional or less saturated functional groups" means that the silicon compound has three or less functional groups, and these functional groups are saturated bonded to silicon (Si).

The said silicon compound is a compound represented by following formula (2), for example.

[Formula 2]

In the above formula (2), for example, X is 2, 3 or 4,

R ¹ and R ² are each a linear or branched alkyl group;

R ¹ and R ² may be the same or different,

R ¹ may be the same or different when X is 2;

R ² may be the same as or different from each other.

Said X and ^R1 are the same as X and ^R1 in Formula (1) mentioned later, for example. Moreover, the illustration of ^R1 in Formula (1) mentioned later can be used for said R ^<2> , for example.

As a specific example of the silicon compound represented by the said formula (2), the compound represented by the following formula (2') whose X is 3 is mentioned, for example. In the following formula (2'), R ¹ and R ² are each the same as in the formula (2) above. When R ¹ and R ² are methyl groups, the silicon compound is trimethoxy(methyl)silane (hereinafter also referred to as “MTMS”).

[Formula 3]

In the liquid containing pulverized gel of the present invention, examples of the solvent include a dispersion medium and the like. The dispersion medium (hereinafter also referred to as "coating solvent") is not particularly limited, and examples thereof include a gelling solvent and a pulverizing solvent described later, and preferably the pulverizing solvent. The solvent for coating includes an organic solvent having a boiling point of 70°C or more and less than 180°C, and a saturated vapor pressure at 20°C of 15 kPa or less.

Examples of the organic solvent include carbon tetrachloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, trichloroethylene, isobutyl alcohol, isopropyl alcohol, isopentyl alcohol, and 1-pentyl. Alcohol (pentanol), ethyl alcohol (ethanol), ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol mono-normal-butyl ether, ethylene glycol monomethyl ether, xylene, cresol, chlorobenzene, isoacetic acid Butyl, isopropyl acetate, isopentyl acetate, ethyl acetate, normal-butyl acetate, normal-propyl acetate, normal-pentyl acetate, cyclohexanol, cyclohexanone, 1,4-dioxane, N,N-dimethylformamide , styrene, tetrachloroethylene, 1,1,1-trichloroethane, toluene, 1-butanol, 2-butanol, methyl isobutyl ketone, methyl ethyl ketone, methylcyclohexanol, methylcyclohexanone, methyl-normal- Butyl ketone, isopentanol, etc. are mentioned. In addition, the dispersion medium may contain an appropriate amount of a perfluoro-based surfactant or a silicone-based surfactant that lowers the surface tension.

The pulverized gel-containing liquid of the present invention includes, for example, a sol particle liquid that is the pulverized sol-like material dispersed in the dispersion medium. The pulverized gel-containing liquid of the present invention can be applied and dried on a substrate, for example, and then chemically crosslinked by a bonding step described later to continuously form a void layer having a film strength of a certain level or higher. do. In the present invention, "sol" means that the three-dimensional structure of a gel is pulverized so that the pulverized material (in other words, particles of a nano-three-dimensional porous sol that retains a part of the pore structure) is dispersed in a solvent to exhibit fluidity. say state

The liquid containing pulverized gel of the present invention may contain, for example, a catalyst for chemically binding the pulverized gel to each other. The content of the catalyst is not particularly limited, but is, for example, 0.01 to 20% by weight, 0.05 to 10% by weight, or 0.1 to 5% by weight based on the weight of the pulverized product of the gel.

Further, the pulverized gel-containing liquid of the present invention may further contain, for example, a crosslinking aid for indirectly binding the pulverized gels to each other. The content of the crosslinking aid is not particularly limited, but is, for example, 0.01 to 20% by weight, 0.05 to 15% by weight, or 0.1 to 10% by weight based on the weight of the pulverized product of the gel.

Further, in the gel pulverized product-containing liquid of the present invention, the ratio of functional groups that do not contribute to the crosslinked structure in the gel among the functional groups of the monomers of the structural unit of the gel is, for example, 30 mol% or less, 25 mol% or less, 20 mol% or less, 15 mol% or less may be sufficient, For example, 1 mol% or more, 2 mol% or more, 3 mol% or more, or 4 mol% or more may be sufficient. The ratio of functional groups not contributing to the crosslinked structure in the gel can be measured, for example, as follows.

(Method for measuring the ratio of functional groups not contributing to the cross-linked structure in the gel)

After drying the gel, solid-state NMR (Si-NMR) is measured, and the ratio of residual silanol groups (functional groups not contributing to the crosslinked structure in the gel) not contributing to the crosslinked structure is calculated from the NMR peak ratio. In addition, even when the functional group is other than a silanol group, the ratio of the functional group not contributing to the crosslinked structure in the gel can be calculated from the NMR peak ratio in accordance with this.

Below, the manufacturing method of the gel pulverized material containing liquid of this invention is demonstrated by giving an example. The following description can be used for the gel pulverized product-containing liquid of the present invention unless otherwise specified.

In the method for producing a liquid containing pulverized gel of the present invention, the mixing step is a step of mixing the porous gel particles (pulverized product) and the solvent, and may or may not be present. As a specific example of the mixing step, a step of mixing a dispersion medium and a pulverized product of a gel-like silicon compound (silicon compound gel) obtained from a silicon compound containing at least trifunctional or less saturated bond functional groups is exemplified. . In the present invention, the pulverized product of the porous gel can be obtained from the porous gel by a gel pulverization step described later. In addition, the pulverized product of the porous gel can be obtained from, for example, the porous gel after aging treatment in which an aging step described later is performed.

In the method for producing a gel pulverized product-containing liquid of the present invention, the gelation step is, for example, a step of gelling a bulky porous body in a solvent to obtain the porous gel, and specific examples of the gelation step include, for example, This is a step of gelling the silicon compound containing at least trifunctional or less saturated functional groups in a solvent to produce a silicon compound gel.

Hereinafter, the gelation step will be described by exemplifying the case where the porous body is a silicon compound.

The gelation step is, for example, a step of gelatinizing the silicon compound as a monomer by a dehydration condensation reaction in the presence of a dehydration condensation catalyst, whereby a silicon compound gel is obtained. The silicon compound gel has, for example, a residual silanol group, and the residual silanol group is preferably adjusted appropriately according to the chemical bonding between the pulverized materials of the silicon compound gel described later.

In the gelation step, the silicon compound is not particularly limited, and may be gelated by a dehydration condensation reaction. By the dehydration condensation reaction, for example, bonds between the silicon compounds are formed. The bond between the silicon compounds is, for example, a hydrogen bond or an intermolecular force bond.

As for the said silicon compound, the silicon compound represented by following formula (1) is mentioned, for example. Since the silicon compound of the said formula (1) has a hydroxyl group, a hydrogen bond or an intermolecular force bond is possible between the silicon compounds of the said formula (1) via each hydroxyl group, for example.

[Formula 4]

In said formula (1), X is 2, 3, or 4, and R ^<1> is a linear or branched alkyl group, for example. The number of carbon atoms in R ¹ is, for example, 1 to 6, 1 to 4, or 1 to 2. Examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group, and the branched alkyl group includes, for example, an isopropyl group and an isobutyl group. can Said X is 3 or 4, for example.

As a specific example of the silicon compound represented by the said formula (1), the compound represented by the following formula (1') whose X is 3 is mentioned, for example. In the following formula (1'), R ¹ is the same as in the formula (1), and is, for example, a methyl group. When R ¹ is a methyl group, the silicon compound is tris(hydroxy)methylsilane. When the said X is 3, the said silicon compound is trifunctional silane which has 3 functional groups, for example.

[Formula 5]

Moreover, as a specific example of the silicon compound represented by the said Formula (1), the compound whose X is 4 is mentioned, for example. In this case, the silicon compound is, for example, a tetrafunctional silane having four functional groups.

The silicon compound may be, for example, a precursor that forms the silicon compound of the formula (1) by hydrolysis. The precursor may be, for example, one capable of generating the silicon compound by hydrolysis, and examples thereof include compounds represented by the above formula (2).

When the said silicon compound is a precursor represented by said Formula (2), the manufacturing method of this invention may also include the process of hydrolyzing the said precursor prior to the said gelation process, for example.

The hydrolysis method is not particularly limited, and can be carried out, for example, by a chemical reaction in the presence of a catalyst. Examples of the catalyst include acids such as oxalic acid and acetic acid. The hydrolysis reaction can be carried out, for example, by slowly adding and mixing an aqueous solution of oxalic acid with the dimethyl sulfoxide solution of the silicon compound precursor in a room temperature environment, followed by stirring as it is for about 30 minutes. When the silicon compound precursor is hydrolyzed, for example, by completely hydrolyzing the alkoxy group of the silicon compound precursor, subsequent gelation, aging, heating after formation of the pore structure, and fixation can be more efficiently expressed.

In this invention, the said silicon compound can illustrate the hydrolyzate of trimethoxy (methyl)silane, for example.

The silicon compound of the monomer is not particularly limited and can be appropriately selected depending on the use of the functional porous body to be produced, for example. In the production of the functional porous body, the silicon compound is preferably the trifunctional silane in view of its excellent low refractive index property, for example, when low refractive index is important, and also has strength (for example, scratch resistance). When importance is placed on compatibility, the above-mentioned tetrafunctional silane is preferable in terms of excellent scratch resistance. In addition, as for the silicon compound used as the raw material of the silicon compound gel, for example, only one type may be used, or two or more types may be used together. As a specific example, the silicon compound may contain, for example, only the trifunctional silane, may contain only the tetrafunctional silane, may contain both the trifunctional silane and the tetrafunctional silane, and furthermore, the Other silicon compounds may also be included. As said silicon compound, when using two or more types of silicon compounds, the ratio in particular is not restrict|limited, It can set suitably.

Gelation of a porous body such as the silicon compound can be performed, for example, by a dehydration condensation reaction between the porous bodies. The dehydration condensation reaction is preferably carried out, for example, in the presence of a catalyst. Examples of the catalyst include acid catalysts such as hydrochloric acid, oxalic acid, and sulfuric acid, and ammonia, potassium hydroxide, sodium hydroxide, and ammonium hydroxide. dehydration condensation catalysts such as base catalysts of The dehydration condensation catalyst may be an acid catalyst or a base catalyst, but a base catalyst is preferable. In the dehydration condensation reaction, the amount of the catalyst added to the porous body is not particularly limited, and the amount of the catalyst is, for example, 0.01 to 10 moles, 0.05 to 7 moles, or 0.1 to 5 moles per mole of the porous body. am.

It is preferable to perform gelation of porous bodies, such as the said silicon compound, in a solvent, for example. The ratio of the porous body in the solvent is not particularly limited. The solvent is, for example, dimethylsulfoxide (DMSO), N-methylpyrrolidone (NMP), N,N-dimethylacetamide (DMAc), dimethylformamide (DMF), γ-butyllactone (GBL) , acetonitrile (MeCN), ethylene glycol ethyl ether (EGEE), and the like. One type of the said solvent may be sufficient as it, and it may use two or more types together, for example. The solvent used for the gelation is hereinafter also referred to as "a solvent for gelation".

Conditions for the gelation are not particularly limited. The treatment temperature for the solvent containing the porous body is, for example, 20 to 30 ° C, 22 to 28 ° C, and 24 to 26 ° C, and the treatment time is, for example, 1 to 60 minutes, 5 to 40 minutes , 10 to 30 minutes. In the case of carrying out the dehydration condensation reaction, the treatment conditions are not particularly limited, and these examples can be used. By performing the gelation, when the porous body is a silicon compound, for example, siloxane bonds grow, primary particles of the silicon compound are formed, and the reaction proceeds further, so that the primary particles form beads with each other. Subsequently, a three-dimensional structured gel is created.

The gel form of the porous body obtained in the gelation step is not particularly limited. "Gel" generally refers to a solidified state in which solutes have a structure in which independent motility is lost for interaction and aggregated. Also, among gels, in general, wet gel means that a dispersion medium is included and the solute takes a uniform structure in the dispersion medium, and xerogel means that the solvent is removed and the solute takes a network structure with pores. say In the present invention, it is preferable to use, for example, a wet gel as the silicon compound gel. When the porous gel is a silicon compound gel, the amount of residual silanol groups in the silicon compound gel is not particularly limited, and for example, the ranges described below can be equally exemplified.

The porous gel obtained by the gelation may be used as it is for the solvent replacement step and the first pulverization step, for example, or may be subjected to aging treatment in the aging step prior to the first pulverization step. In the aging step, the gelled porous body (porous body gel) is aged in a solvent. In the aging step, conditions for the aging treatment are not particularly limited, and, for example, the porous gel may be incubated in a solvent at a predetermined temperature. According to the aging treatment, for example, in a porous gel having a three-dimensional structure obtained by gelation, the primary particles can be further grown, thereby increasing the size of the particles themselves. And, as a result, it is possible to increase the contact state of the neck portion where the particles are in contact with each other, for example, from point contact to surface contact. The strength of the porous gel subjected to the aging treatment as described above increases, for example, the gel itself, and as a result, the strength of the three-dimensional basic structure of the pulverized product after pulverization can be further improved. Accordingly, when a coating film is formed using the gel pulverized product-containing liquid of the present invention, for example, even in the drying step after coating, the pore size of the void structure in which the three-dimensional basic structure is deposited depends on the drying step. It is possible to suppress shrinkage accompanying volatilization of the solvent in the coating film that occurs in the coating film.

The lower limit of the temperature of the aging treatment is, for example, 30 ° C. or higher, 35 ° C. or higher, or 40 ° C. or higher, and the upper limit thereof is, for example, 80 ° C. or lower, 75 ° C. or lower, or 70 ° C. or lower, The ranges are, for example, 30 to 80°C, 35 to 75°C, and 40 to 70°C. The predetermined time period is not particularly limited, and has a lower limit of, for example, 5 hours or more, 10 hours or more, or 15 hours or more, and an upper limit thereof, for example, 50 hours or less, 40 hours or less, or 30 hours. It is the following, and the range is 5 to 50 hours, 10 to 40 hours, and 15 to 30 hours, for example. Regarding the optimum conditions for aging, for example, as described above, in the porous gel, an increase in the size of the primary particles and an increase in the contact area of the neck portion are set to conditions that are obtained. it is desirable Further, in the aging step, it is preferable to consider, for example, the boiling point of the solvent to be used as the temperature of the aging treatment. In the aging treatment, for example, if the aging temperature is too high, there is a possibility of causing problems such as excessive volatilization of the solvent and closing of pores of the three-dimensional void structure due to concentration of the coating liquid. there is. On the other hand, in the aging process, for example, if the aging temperature is too low, the effect of the aging is not sufficiently obtained, and the temperature deviation due to the passage of time in the mass production process increases, resulting in a product with poor quality. there is

For example, the same solvent as in the gelation step can be used for the aging treatment, and specifically, it is preferable to perform the reaction product after the gel treatment (ie, the solvent containing the porous gel) as it is. . When the porous gel is the silicon compound gel, the number of moles of residual silanol groups contained in the silicon compound gel that has undergone the aging treatment after gelation is, for example, the raw material used for gelation (for example, the silicon compound or a precursor thereof). ) is the ratio of residual silanol groups when the number of moles of alkoxy groups is 100, the lower limit is, for example, 50% or more, 40% or more, or 30% or more, and the upper limit is, for example, 1% Below, it is 3 % or less and 5 % or less, and the range is 1 to 50 %, 3 to 40 %, and 5 to 30 %, for example. For the purpose of increasing the hardness of the silicon compound gel, for example, a lower molar number of residual silanol groups is preferred. If the number of moles of residual silanol groups is too high, for example, in forming the functional porous body, there is a possibility that the pore structure cannot be maintained until the precursor of the functional porous body is crosslinked. On the other hand, if the number of moles of residual silanol groups is too low, for example, in the bonding step, the functional porous body precursor may not be crosslinked and sufficient film strength may not be imparted. In addition, although the above is an example of a residual silanol group, the same phenomenon applies also to each functional group, for example, when using what modified the said silicon compound with various reactive functional groups as a raw material of the said silicon compound gel. can do.

The porous gel obtained by the gelation is, for example, subjected to an aging treatment in the aging step, followed by a solvent replacement step, and then subjected to the gel crushing step. In the solvent substitution step, the solvent is replaced with another solvent.

In the present invention, the gel crushing step is a step of crushing the porous gel, as described above. The pulverization may be performed, for example, on the porous gel after the gelation step or on the porous gel after aging after the aging treatment.

In addition, as described above, a gel shape control step for controlling the shape and size of the gel may be performed prior to the solvent substitution step (for example, after the aging step). The shape and size of the gel to be controlled in the gel shape control step are not particularly limited, but are as described above, for example. The gel form control step may be performed by, for example, dividing (eg, cutting) the gel into solids (three-dimensional bodies) having appropriate sizes and shapes.

In addition, as described above, the gel pulverization step is performed after the solvent substitution step is performed on the gel. In the solvent substitution step, the solvent is replaced with another solvent. If the solvent is not replaced with the other solvent, for example, the catalyst and the solvent used in the gelation step remain after the aging step, and gelation occurs over time, resulting in a pot of finally obtained liquid containing pulverized gel. This is because there is a fear of affecting the life, a fear of lowering the drying efficiency when drying the coating film formed using the liquid containing the pulverized gel. In addition, the said other solvent in the said gel grinding process is hereinafter also called "a grinding solvent."

The solvent for grinding (other solvents) is not particularly limited, and organic solvents can be used, for example. Examples of the organic solvent include solvents having a boiling point of 140°C or less, 130°C or less, and a boiling point of 100°C or less and 85°C or less. Specific examples include isopropyl alcohol (IPA), ethanol, methanol, n-butanol, 2-butanol, isobutyl alcohol, pentyl alcohol, propylene glycol monomethyl ether (PGME), methyl cellosolve, and acetone. etc. can be mentioned. The solvent for pulverization may be one type or a combination of two or more types, for example.

In addition, when the polarity of the grinding solvent is low, for example, the solvent replacement step is divided into a plurality of solvent replacement steps, and in the solvent replacement step, the step performed later is performed first. You may make the hydrophilicity of the said other solvent lower than a step. By doing in this way, it is also possible, for example, to improve the solvent replacement efficiency and to make the residual amount of the gel preparation solvent (eg DMSO) in the gel extremely low. As a specific example, for example, the above solvent substitution step is divided into three solvent substitution steps, and in the first solvent substitution step, DMSO in the gel is first substituted with water, and then in the second solvent substitution step, The water in the gel may be substituted with IPA, and further, the IPA in the gel may be substituted with isobutyl alcohol in the third substitution step.

The combination of the solvent for gelation and the solvent for grinding is not particularly limited, and examples include a combination of DMSO and IPA, a combination of DMSO and ethanol, a combination of DMSO and isobutyl alcohol, a combination of DMSO and n-butanol, and the like. can be heard In this way, by substituting the solvent for gelation with the solvent for crushing, a more uniform coating film can be formed, for example, in the formation of a coating film described later.

Although the said solvent replacement process is not specifically limited, For example, it can be implemented as follows. That is, first, the gel produced by the gel production step (for example, the gel after the aging treatment) is immersed or brought into contact with the other solvent, the catalyst for gel production in the gel, the alcohol component generated by the condensation reaction, Water or the like is dissolved in the other solvent. Thereafter, the solvent in which the gel was immersed or contacted is discarded, and the gel is immersed or contacted again in a new solvent. This is repeated until the remaining amount of the gel preparation solvent in the gel reaches a desired amount. The immersion time per one time is, for example, 0.5 hours or more, 1 hour or more, or 1.5 hours or more, and the upper limit is not particularly limited, but is, for example, 10 hours or less. In addition, immersion in the solvent may correspond to continuous contact of the solvent with the gel. In addition, the temperature during the immersion is not particularly limited, but may be, for example, 20 to 70°C, 25 to 65°C, or 30 to 60°C. When heated, solvent substitution proceeds quickly, and the amount of solvent required for substitution is reduced, but solvent substitution may be carried out conveniently at room temperature. Further, for example, when the solvent substitution step is divided into a plurality of solvent substitution steps, each of the plurality of solvent substitution steps may be performed as described above.

When the solvent substitution step is divided into a plurality of solvent substitution steps and the hydrophilicity of the other solvent is lower in the later step than in the earlier step, the other solvent (substitution solvent) is particularly limited. It doesn't work. In the solvent replacement step performed at the end, it is preferable that the other solvent (substitution solvent) is a void layer preparation solvent. Examples of the solvent for preparing the void layer include solvents having a boiling point of 140°C or less. In addition, examples of the solvent for producing the void layer include alcohol, ether, ketone, ester solvent, aliphatic hydrocarbon solvent, and aromatic solvent. Specific examples of the alcohol having a boiling point of 140° C. or lower include, for example, isopropyl alcohol (IPA), ethanol, methanol, n-butanol, 2-butanol, isobutyl alcohol (IBA), 1-pentanol, and 2-pentane. All can be heard. Specific examples of the ether having a boiling point of 140°C or less include propylene glycol monomethyl ether (PGME), methyl cellosolve, and ethyl cellosolve. Specific examples of the ketone having a boiling point of 140°C or lower include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclopentanone. Specific examples of the ester solvent having a boiling point of 140°C or lower include ethyl acetate, butyl acetate, isopropyl acetate, and normal propyl acetate. Specific examples of the aliphatic hydrocarbon-based solvent having a boiling point of 140°C or lower include hexane, cyclohexane, heptane, and octane. Specific examples of the aromatic solvent having a boiling point of 140°C or less include toluene, benzene, xylene, anisole and the like. At the time of coating, from a viewpoint that it is difficult to corrode a base material (eg, a resin film), the solvent for producing the void layer is preferably an alcohol, ether, or an aliphatic hydrocarbon-based solvent. In addition, the solvent for pulverization may be, for example, one type or a combination of two or more types. In particular, isopropyl alcohol (IPA), ethanol, n-butanol, 2-butanol, isobutyl alcohol (IBA), pentyl alcohol, propylene glycol monomethyl ether (PGME), methyl cellosolve, heptane, and octane at room temperature It is preferable from the viewpoint of low volatility. In particular, it is preferable that the saturated vapor pressure of the solvent for preparing the void layer is not too high (volatility is not too high) in order to suppress the scattering of particles (for example, silica compounds), which are the material of the gel. As such a solvent, for example, a solvent having an aliphatic group having 3 or 4 or more carbon atoms is preferable, and a solvent having an aliphatic group having 4 or more carbon atoms is more preferable. The solvent having an aliphatic group having 3 or 4 or more carbon atoms may be, for example, alcohol. As such a solvent, specifically, for example, isopropyl alcohol (IPA), isobutyl alcohol (IBA), n-butanol, 2-butanol, 1-pentanol, and 2-pentanol are preferable, particularly isopropyl alcohol (IPA), isobutyl alcohol (IBA), and Butyl alcohol (IBA) is preferred.

The other solvent (solvent for substitution) other than the solvent substitution step performed last is not particularly limited, and examples thereof include alcohol, ether, and ketone. As a specific example of alcohol, isopropyl alcohol (IPA), ethanol, methanol, n-butanol, 2-butanol, isobutyl alcohol (IBA), pentyl alcohol, etc. are mentioned, for example. Specific examples of the ether include propylene glycol monomethyl ether (PGME), methyl cellosolve, and ethyl cellosolve. As a specific example of a ketone, acetone etc. are mentioned, for example. The said other solvent (solvent for substitution) should just be able to substitute the said other solvent (solvent for substitution) in the said gel preparation solvent or the previous stage. In addition, the other solvent (solvent for substitution) in the last step other than the solvent replacement step does not remain in the gel at the end, or even if it remains, it erodes the base material (eg resin film) during coating. Solvents that are difficult to do are preferred. At the time of coating, from a viewpoint that it is difficult to corrode a base material (eg, resin film), the said other solvent (solvent for substitution) other than the said solvent substitution step performed last is preferably alcohol. Thus, in at least one of the plurality of solvent substitution steps, it is preferred that the other solvent is an alcohol.

In the solvent replacement step performed first, the other solvent may be, for example, water or a mixed solvent containing water in an arbitrary ratio. Water or a mixed solvent containing water is highly compatible with a hydrophilic solvent for gel production (eg DMSO), so it is easy to replace the solvent for gel production, and is also preferable from the viewpoint of cost.

The plurality of solvent substitution steps include a step in which the other solvent is water, a step in which the other solvent is a solvent having an aliphatic group having 3 or less carbon atoms, and a step in which the other solvent is a solvent having an aliphatic group having 3 or less carbon atoms. A step of being a solvent having an aliphatic group may be included. In addition, at least one of the solvent having an aliphatic group of 3 or less carbon atoms and the solvent having an aliphatic group of 4 or more carbon atoms may be alcohol. The alcohol having an aliphatic group of 3 or less carbon atoms is not particularly limited, and examples thereof include isopropyl alcohol (IPA), ethanol, methanol, and n-propyl alcohol. The alcohol having an aliphatic group having 4 or more carbon atoms is not particularly limited, and examples thereof include n-butanol, 2-butanol, isobutyl alcohol (IBA), and pentyl alcohol. For example, the solvent having an aliphatic group of 3 or less carbon atoms may be isopropyl alcohol, and the solvent having an aliphatic group of 4 or more carbon atoms may be isobutyl alcohol.

The present inventors have found that it is very important to pay attention to the residual amount of the solvent for preparing the gel in order to form a porous layer having film strength under relatively mild conditions of, for example, 200°C or less. This knowledge is not disclosed in the prior art including the above-mentioned patent documents and non-patent documents, but is a knowledge independently discovered by the present inventors.

The reason (mechanism) that a void layer with a low refractive index can be produced by reducing the remaining amount of the gel preparation solvent in the gel in this way is unknown, but is estimated as follows, for example. That is, as described above, the solvent for gel production is preferably a high boiling point solvent (for example, DMSO etc.) in order to advance the gelation reaction. In addition, when preparing a pore layer by coating and drying the sol liquid prepared from the gel, at a normal drying temperature and drying time (for example, 1 minute at 100 ° C., etc., although not particularly limited), the high boiling point solvent is difficult to completely remove. This is because if the drying temperature is too high or the drying time is too long, problems such as deterioration of the substrate may occur. In addition, the high boiling point solvent remaining during the coating and drying enters between the pulverized materials of the gel and causes the pulverized materials to slide, so that the pulverized materials are densely deposited and the porosity is reduced. , it is estimated that low refractive index is difficult to develop. That is, conversely, it is considered that by reducing the residual amount of the high boiling point solvent, such a phenomenon can be suppressed and a low refractive index can be developed. However, these are examples of estimated mechanisms and do not limit the present invention in any way.

In the present invention, the "solvent" (for example, a solvent for producing a gel, a solvent for forming a void layer, a solvent for substitution, etc.) does not have to dissolve the gel or its pulverized product, etc., and, for example, the gel or The pulverized material or the like may be dispersed or precipitated in the solvent.

As described above, the solvent for producing the gel may have a boiling point of, for example, 140°C or higher.

The solvent for preparing the gel is, for example, a water-soluble solvent. In the present invention, a "water-soluble solvent" refers to a solvent that can be mixed with water in an arbitrary ratio.

When the solvent substitution step is performed by dividing the solvent substitution step into a plurality of solvent substitution steps, the method is not particularly limited, but each solvent substitution step can be performed as follows, for example. That is, first, the gel is immersed or brought into contact with the other solvent, and the catalyst for gel production in the gel, the alcohol component produced by the condensation reaction, water, and the like are dissolved in the other solvent. Thereafter, the solvent in which the gel was immersed or contacted is discarded, and the gel is immersed or contacted again in a new solvent. This is repeated until the remaining amount of the gel preparation solvent in the gel reaches a desired amount. The immersion time per one time is, for example, 0.5 hours or more, 1 hour or more, or 1.5 hours or more, and the upper limit is not particularly limited, but is, for example, 10 hours or less. In addition, immersion in the solvent may correspond to continuous contact of the solvent with the gel. In addition, the temperature during the immersion is not particularly limited, but may be, for example, 20 to 70°C, 25 to 65°C, or 30 to 60°C. When heated, solvent substitution proceeds quickly, and the amount of solvent required for substitution is reduced, but solvent substitution may be carried out conveniently at room temperature. In this solvent replacement step, the other solvent (solvent for replacement) is gradually changed from a solvent having high hydrophilicity to a solvent having low hydrophilicity (highly hydrophobic), and this is carried out a plurality of times. In order to remove the highly hydrophilic gel preparation solvent (eg, DMSO etc.), it is simple and efficient to first use water as the substitution solvent, for example, as described above. Then, after removing DMSO or the like with water, the water in the gel is substituted in the order of, for example, isopropyl alcohol ⇒ isobutyl alcohol (solvent for coating). That is, since water and isobutyl alcohol have low compatibility, solvent substitution can be performed efficiently by substituting once with isopropyl alcohol and then substituting with isobutyl alcohol as a coating solvent. However, this is an example, and as described above, the other solvent (solvent for substitution) is not particularly limited.

In the present invention, the method for producing a gel is, for example, as described above, in the solvent substitution step, the other solvent (solvent for substitution) is gradually changed from a solvent having high hydrophilicity to a solvent having low hydrophilicity (high hydrophobicity). ) solvent and may be carried out a plurality of times. According to this, as described above, the residual amount of the gel preparation solvent in the gel can be made extremely low. In addition to that, for example, rather than performing solvent substitution in one step using only the solvent for coating, the amount of solvent used can be suppressed to an extremely low level, and the cost can be reduced.

Then, after the solvent replacement step, a gel crushing step of pulverizing the gel in the pulverizing solvent is performed. In addition, for example, as described above, after the solvent replacement step and before the gel grinding step, if necessary, the gel concentration may be measured, and then, if necessary, the gel concentration adjustment step may be performed. may be carried out. The gel concentration measurement after the solvent replacement step and before the gel grinding step can be performed, for example, as follows. That is, first, after the solvent replacement step, the gel is taken out in the other solvent (solvent for grinding). This gel is controlled into an agglomerate of an appropriate shape and size (for example, block-like) by, for example, the gel shape control step described above. Next, after removing the solvent adhering to the periphery of the gel mass, the concentration of the solid content in one gel mass is measured by a gravimetric drying method. At this time, in order to obtain the reproducibility of the measured value, the measurement is performed on a plurality of (for example, 6) lumps taken out at random, and the average value and the deviation of the value are calculated. In the concentration adjustment step, the gel concentration of the gel-containing liquid may be reduced by, for example, further adding the other solvent (solvent for pulverization). In the concentration adjustment step, conversely, the gel concentration of the gel-containing liquid may be increased by evaporating the other solvent (solvent for pulverization).

In the method for producing a gel pulverized product-containing liquid of the present invention, as described above, the gel pulverization step may be performed in one step, but it is preferable to divide the gel pulverization step into a plurality of pulverization steps. Specifically, for example, the first crushing step and the second crushing step may be performed. In the gel crushing step, in addition to the first crushing step and the second crushing step, a gel crushing step may be further performed. That is, in the manufacturing method of the present invention, the gel crushing step is not limited to the two-step crushing step, and may include three or more crushing steps.

As described above, a liquid (for example, a suspension) containing the fine pore particles (a pulverized product of a gel compound) can be prepared. In addition, a liquid containing the microporous particles and the catalyst can be prepared by adding a catalyst for chemically binding the microporous particles to each other after or during the production process of the liquid containing the microporous particles. can The addition amount of the catalyst is not particularly limited, but is, for example, 0.01 to 20% by weight, 0.05 to 10% by weight, or 0.1 to 5% by weight with respect to the weight of the pulverized material of the gelled silicon compound. The catalyst may be, for example, a catalyst that promotes cross-linking of the fine pore particles. It is preferable to use a dehydration condensation reaction of residual silanol groups contained in silica sol molecules as a chemical reaction for chemically bonding the fine porous particles to each other. By accelerating the reaction between hydroxyl groups of silanol groups with the above catalyst, continuous film formation that cures the void structure in a short time is possible. As said catalyst, a photoactive catalyst and a thermally active catalyst are mentioned, for example. According to the photoactive catalyst, for example, in the void layer forming step, the microporous particles can be chemically bonded (for example, cross-linked) without heating. According to this, for example, in the step of forming the void layer, since shrinkage of the entire void layer does not occur easily, a higher porosity can be maintained. In addition to or instead of the above catalyst, a substance that generates a catalyst (catalyst generator) may be used. For example, in addition to or instead of the above photoactive catalyst, a substance that generates a catalyst by light (photocatalyst generator) may be used, and in addition to or instead of the above thermally active catalyst, a catalyst by heat You may use a substance that generates (thermal catalyst generator). The photocatalyst generator is not particularly limited, but examples thereof include a photobase generator (a substance that generates a basic catalyst by light irradiation), a photoacid generator (a substance that generates an acidic catalyst by light irradiation), and the like. substances), etc., and photobase generators are preferable. Examples of the photobase generator include 9-anthrylmethyl N,N-diethylcarbamate (trade name: WPBG-018), (E)-1-[3- (2-hydroxyphenyl)-2-propenoyl]piperidine ((E)-1-[3-(2-hydroxyphenyl)-2-propenoyl]piperidine, trade name WPBG-027), 1-(anthraquinone -2-yl)ethyl imidazolecarboxylate (1-(anthraquinon-2-yl)ethyl imidazolecarboxylate, trade name WPBG-140), 2-nitrophenylmethyl 4-methacryloyloxypiperidine-1-carboxylate (trade name WPBG-165), 1,2-diisopropyl-3-[bis(dimethylamino)methylene]guanidium 2-(3-benzoylphenyl)propionate (trade name WPBG-266), 1,2- Dicyclohexyl-4,4,5,5-tetramethylbiguanidium n-butyltriphenylborate (trade name: WPBG-300), and 2-(9-oxoxanthen-2-yl)propionic acid 1,5,7 - triazabicyclo[4.4.0]deca-5-ene (Tokyo Chemical Industry Co., Ltd.), a compound containing 4-piperidinemethanol (trade name: HDPD-PB100: manufactured by Heraeus), and the like. In addition, all of the trade names containing the above "WPBG" are trade names of Wako Pure Chemical Industries, Ltd. Examples of the photoacid generator include aromatic sulfonium salts (trade name SP-170: ADEKA), triarylsulfonium salts (trade name CPI101A: San Afro), aromatic iodonium salts (trade name Irgacure250: Ciba Japan), and the like. can be heard In addition, the catalyst for chemically binding the microporous particles to each other is not limited to the photoactive catalyst and the photocatalyst generator, and may be, for example, a thermally active catalyst or a thermal catalyst generator. Examples of the catalyst for chemically binding the microporous particles to each other include base catalysts such as potassium hydroxide, sodium hydroxide, and ammonium hydroxide, and acid catalysts such as hydrochloric acid, acetic acid, and oxalic acid. Among these, base catalysts are preferred. A catalyst or catalyst generator that chemically binds the microporous particles to each other is used by adding to, for example, a sol particle liquid (eg, suspension) containing the pulverized product (microporous particles) immediately before coating, or Alternatively, it can be used as a mixed solution obtained by mixing the above catalyst or catalyst generator with a solvent. The mixed solution may be, for example, a coating solution directly added and dissolved in the sol particle solution, a solution in which the catalyst or catalyst generator is dissolved in a solvent, or a dispersion in which the catalyst or catalyst generator is dispersed in a solvent. The solvent is not particularly limited, and examples thereof include water and a buffer solution.

Further, for example, after preparing the liquid containing the microporous particles, by adding a small amount of a high boiling point solvent to the liquid containing the microporous particles, it is possible to improve the film appearance during film formation by coating. It happens. The amount of the high boiling point solvent is not particularly limited, but is, for example, 0.05 to 0.8 times, 0.1 to 0.5 times, and particularly 0.15 to 0.4 times the solid content of the fine-pore particle-containing liquid. Examples of the high boiling point solvent include, but are not limited to, dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and N-methylpyrroly. Don (NMP), γ-butyl lactone (GBL), ethylene glycol ethyl ether (EGEE), and the like. In particular, a solvent having a boiling point of 110 deg. C or higher is preferable and is not limited to the above specific examples. It is considered that the high boiling point solvent acts instead of a leveling agent at the time of forming a film in which particles are formed side by side. It is preferable to use the above-mentioned high boiling point solvent even in the case of gel synthesis. However, if the solvent used in the synthesis is completely removed and then the high boiling point solvent is added again after preparing the liquid containing the microporous particles, it tends to work efficiently, although the details are unclear. Further, the added high boiling point solvent remains in the membrane skeleton even after film formation, and is thought to affect the permeation of the pressure-sensitive adhesive directly laminated on the membrane into pores in the membrane. That is, it is estimated that the slight difference in solubility of the adhesive to the high boiling point solvent in the film of the pressure-sensitive adhesive is one of the factors causing the difference in penetration of the pressure-sensitive adhesive into the voids in the film. However, these mechanisms are examples and do not limit the present invention in any way.

[4-3. Manufacturing method of laminate, void layer, and adhesive layer]

Below, the manufacturing method of the laminated body of this invention is demonstrated by giving an example together with the manufacturing method of the void layer which comprises the said laminated body, and the manufacturing method of the adhesive layer. In the following, the case where the void layer of the present invention described above is a silicon porous body formed of a silicon compound will be mainly described. However, the void layer of the present invention is not limited to the silicon porous body. In the case where the void layer of the present invention is other than a silicon porous body, the following description can be applied mutatis mutandis unless otherwise specified.

The manufacturing method of the void layer of the present invention includes, for example, a precursor forming step of forming a precursor of the void layer using the pulverized gel material-containing liquid of the present invention, and the pulverized gel material included in the precursor. A bonding step of chemically bonding the pulverized materials of the containing liquid to each other is included. The said precursor can also be said to be a coating film, for example.

According to the manufacturing method of the air gap layer of this invention, the porous structure which exhibits the same function as an air layer is formed, for example. The reason is guessed as follows, for example, but the present invention is not limited to this guess. Hereinafter, a case in which the porous layer of the present invention is a silicon porous material will be described as an example.

Since the pulverized gel material-containing liquid of the present invention used in the production method of the silicon porous body contains the pulverized material of the silicon compound gel, the three-dimensional structure of the gel-like silica compound is dispersed in a three-dimensional basic structure, there is. For this reason, in the production method of the silicon porous body, for example, when the precursor (eg, coated film) is formed using the liquid containing the pulverized gel, the three-dimensional basic structure is deposited, and the three-dimensional basic structure is formed. A void structure based on is formed. In short, according to the method for producing a porous silicon body, a new three-dimensional structure formed from the pulverized product of the three-dimensional basic structure, which is different from the three-dimensional structure of the silicon compound gel, is formed. Further, in the production method of the silicon porous body, the new three-dimensional structure is fixed because the pulverized materials are further chemically bonded to each other. For this reason, although the silicon porous body obtained by the method for producing a silicon porous body has a structure having voids, sufficient strength and flexibility can be maintained. The air gap layer (for example, silicon porous body) obtained by the present invention is, for example, a member using air gaps, and is used in a wide range of products such as heat insulating materials, sound absorbing materials, optical members, and ink receiving layers. It is possible to do it, and it is possible to manufacture laminated films to which various functions are imparted.

As for the method for producing the void layer of the present invention, unless otherwise specified, the description of the pulverized gel product-containing liquid of the present invention can be used.

In the step of forming the precursor of the porous body, for example, the liquid containing the pulverized gel of the present invention is coated on the substrate. The pulverized gel-containing liquid of the present invention is, for example, coated on a substrate, and after drying the coated film, chemically bonding (eg, cross-linking) the pulverized materials to each other by the bonding step, It is possible to continuously form a void layer having a film strength equal to or higher than the level.

The coating amount of the liquid containing the pulverized gel on the substrate is not particularly limited, and can be appropriately set depending on, for example, the desired thickness of the void layer of the present invention. As a specific example, in the case of forming the porous silicon body having a thickness of 0.1 to 1000 μm, the coating amount of the liquid containing the pulverized gel material on the substrate is, for example, 0.01 to 0.01 μm of the pulverized material per 1 m 2 of area of the substrate. 60000 μg, 0.1 to 5000 μg, and 1 to 50 μg. The preferred coating amount of the gel pulverized product-containing liquid is difficult to define uniquely because it is related to, for example, the concentration of the liquid and the coating method, but considering productivity, it is preferable to apply as thin a layer as possible. If the application amount is too large, for example, the possibility of drying in a drying furnace before the solvent volatilizes increases. Accordingly, there is a possibility that the formation of voids is inhibited and the porosity is greatly reduced by drying the solvent before sedimentation and deposition of the nano-ground sol particles in the solvent and formation of the pore structure. On the other hand, if the application amount is too thin, there is a possibility that the risk of occurrence of coating repellent due to unevenness of the base material, variations in hydrophilicity and hydrophobicity, etc. may increase.

After coating the liquid containing the pulverized gel on the substrate, a drying treatment may be applied to the precursor of the porous body (coating film). By the drying treatment, for example, the solvent in the precursor of the porous body (the solvent contained in the gel pulverized product-containing liquid) is not only removed, but also the sol particles are precipitated and deposited during the drying treatment to form a pore structure. It aims to form. The temperature of the drying treatment is, for example, 50 to 250°C, 60 to 150°C, or 70 to 130°C, and the drying treatment time is, for example, 0.1 to 30 minutes, 0.2 to 10 minutes, or 0.3 to 130 minutes. 3 minutes. Regarding the drying treatment temperature and time, a lower and shorter one is preferable, for example, in relation to the development of continuous productivity and high porosity. If the conditions are too strict, for example, when the base material is a resin film, as the glass transition temperature of the base material approaches, the base material extends in the drying furnace, causing defects such as cracks in the void structure formed immediately after coating. There is a possibility. On the other hand, when the conditions are too loose, for example, since residual solvent is included at the timing of exiting the drying furnace, there is a possibility that cosmetic problems such as scratches may occur when rubbing against a roll in the next step.

The drying treatment may be, for example, natural drying, heat drying, or reduced pressure drying. The drying method is not particularly limited, and, for example, a general heating means may be used. As for the said heating means, a hot air blower, a heating roll, a far-infrared heater etc. are mentioned, for example. Especially, when it is premised on industrial continuous production, it is preferable to use heat drying. As for the solvent to be used, a solvent with low surface tension is preferable for the purpose of suppressing the generation of shrinkage stress accompanying volatilization of the solvent during drying and the consequent cracking phenomenon of the void layer (the silicon porous body). Examples of the solvent include lower alcohols typified by isopropyl alcohol (IPA), hexane, and perfluorohexane, but are not limited thereto.

The substrate is not particularly limited, and examples thereof include a substrate made of thermoplastic resin, a substrate made of glass, an inorganic substrate represented by silicon, a plastic molded with a thermosetting resin, etc., an element such as a semiconductor, and a carbon represented by carbon nanotube. Fiber-based materials and the like can be preferably used, but are not limited thereto. As for the form of the said base material, a film, a plate, etc. are mentioned, for example. The thermoplastic resin, for example, polyethylene terephthalate (PET), acrylic, cellulose acetate propionate (CAP), cycloolefin polymer (COP), triacetyl cellulose (TAC), polyethylene naphthalate (PEN), polyethylene ( PE), polypropylene (PP), and the like.

In the manufacturing method of the void layer of the present invention, the bonding step is a step of chemically bonding the pulverized materials included in the porous body precursor (coated film) to each other. Through the bonding step, for example, the three-dimensional structure of the pulverized material in the precursor of the porous body is fixed. In the case of performing immobilization by conventional sintering, for example, a dehydration condensation reaction of silanol groups and formation of siloxane bonds are induced by performing a high-temperature treatment at 200°C or higher. In the bonding step in the present invention, by reacting various additives that catalyze the dehydration condensation reaction, for example, when the substrate is a resin film, without causing damage to the substrate, around 100 ° C. With a relatively low drying temperature and a short treatment time of less than a few minutes, it is possible to continuously form and immobilize the pore structure.

The chemical bonding method is not particularly limited, and can be appropriately determined depending on the type of the gel (eg, silicon compound gel), for example. As a specific example, the chemical bonding may be performed by, for example, chemical cross-linking of the pulverized materials, and in addition, inorganic particles such as titanium oxide may be added to the pulverized materials. In one case, it is also conceivable to chemically cross-link the inorganic particles and the pulverized product. In addition, in the case where a biocatalyst such as an enzyme is supported, there is also a case where the pulverized product is chemically cross-linked with a site other than the catalytically active site. Accordingly, the present invention can be applied to, for example, not only a void layer formed of the sol particles, but also an organic-inorganic hybrid void layer, a host-guest void layer, and the like, but is not limited thereto.

The bonding step can be carried out by a chemical reaction in the presence of a catalyst, for example, depending on the kind of pulverized material of the gel (for example, silicon compound gel). As the chemical reaction in the present invention, it is preferable to use a dehydration condensation reaction of residual silanol groups contained in the pulverized product of the silicon compound gel. By accelerating the reaction between hydroxyl groups of silanol groups with the above catalyst, continuous film formation that cures the void structure in a short time is possible. Examples of the catalyst include, but are not limited to, base catalysts such as potassium hydroxide, sodium hydroxide, and ammonium hydroxide, and acid catalysts such as hydrochloric acid, acetic acid, and oxalic acid. The catalyst for the dehydration condensation reaction is particularly preferably a base catalyst. Moreover, a photoacid generating catalyst, a photobase generating catalyst, etc. which express catalytic activity by irradiating light (for example, ultraviolet-ray) can also be used suitably. Although it does not specifically limit as a photoacid generation catalyst and a photobase generation catalyst, For example, it is as above-mentioned. For example, as described above, the catalyst is preferably added to the sol particle liquid containing the pulverized product immediately before coating, or used as a mixed solution obtained by mixing the catalyst with a solvent. The mixed solution may be, for example, a coating solution obtained by directly adding and dissolving the sol particle solution, a solution obtained by dissolving the catalyst in a solvent, or a dispersion obtained by dispersing the catalyst in a solvent. The solvent is not particularly limited, and as described above, examples thereof include water and a buffer solution.

Further, for example, a crosslinking aid for indirectly binding the pulverized gels to each other may be added to the gel-containing liquid of the present invention. This crosslinking auxiliary agent enters between the particles (the above-mentioned pulverized product), and the particles and the crosslinking auxiliary agent interact or bond with each other, so that even particles separated by a distance can be bonded together, and the strength can be increased efficiently. . As the crosslinking aid, a polyvalent crosslinking silane monomer is preferable. Specifically, the polyvalent silane monomer has, for example, 2 or more and 3 or less alkoxysilyl groups, the chain length between the alkoxysilyl groups may be 1 or more and 10 or less carbon atoms, and may also contain elements other than carbon. Examples of the crosslinking aid include bis(trimethoxysilyl)ethane, bis(triethoxysilyl)ethane, bis(trimethoxysilyl)methane, bis(triethoxysilyl)methane, and bis(triethene). Toxysilyl)propane, bis(trimethoxysilyl)propane, bis(triethoxysilyl)butane, bis(trimethoxysilyl)butane, bis(triethoxysilyl)pentane, bis(trimethoxysilyl)pentane, Bis(triethoxysilyl)hexane, bis(trimethoxysilyl)hexane, bis(trimethoxysilyl)-N-butyl-N-propyl-ethane-1,2-diamine, tris-(3-trimethoxy) Silylpropyl) isocyanurate, tris-(3-triethoxysilylpropyl) isocyanurate, etc. are mentioned. The addition amount of the crosslinking aid is not particularly limited, but is, for example, 0.01 to 20% by weight, 0.05 to 15% by weight, or 0.1 to 10% by weight with respect to the weight of the pulverized material of the silicon compound.

The chemical reaction in the presence of the catalyst is, for example, light irradiation or heating to the coating film containing the catalyst or catalyst generator previously added to the gel pulverized product-containing liquid, or to the coating film, It can be carried out by light irradiation or heating after spraying the catalyst, or by light irradiation or heating while spraying the catalyst or catalyst generator. For example, when the catalyst is a photoactive catalyst, the porous silicon body can be formed by chemically bonding the microporous particles to each other by light irradiation. In the case where the catalyst is a thermally activated catalyst, the porous silicon body can be formed by chemically bonding the microporous particles to each other by heating. The light irradiation amount (energy) in the light irradiation is not particularly limited, but is, for example, 200 to 800 mJ/cm 2 , 250 to 600 mJ/cm 2 , or 300 to 400 mJ/cm 2 in terms of @ 360 nm. . From the viewpoint of preventing an insufficient amount of irradiation and decomposition due to light absorption of the catalyst generator from not proceeding, resulting in an insufficient effect, a cumulative light amount of 200 mJ/cm 2 or more is preferable. In addition, from the viewpoint of preventing thermal wrinkles from occurring due to damage to the base material under the void layer, a cumulative light amount of 800 mJ/cm 2 or less is preferable. The wavelength of light in the light irradiation is not particularly limited, but is, for example, 200 to 500 nm and 300 to 450 nm. The light irradiation time in the light irradiation is not particularly limited, and is, for example, 0.1 to 30 minutes, 0.2 to 10 minutes, and 0.3 to 3 minutes. Conditions for the heat treatment are not particularly limited, and the heating temperature is, for example, 50 to 250°C, 60 to 150°C, and 70 to 130°C, and the heating time is, for example, 0.1 to 30 minutes. , 0.2 to 10 minutes, and 0.3 to 3 minutes. As for the solvent used, a solvent with low surface tension is preferable, for example, for the purpose of suppressing the generation of shrinkage stress accompanying volatilization of the solvent during drying and the consequent cracking of the void layer. For example, although a lower alcohol represented by isopropyl alcohol (IPA), hexane, perfluorohexane, etc. are mentioned, it is not limited to these.

In the above manner, the void layer (for example, silicon porous body) of the present invention can be produced. However, the manufacturing method of the void layer of this invention is not limited to the above. In addition, the void layer of the present invention, which is a silicon porous body, is sometimes referred to as "the silicon porous body of the present invention" below.

In addition, in the production of the laminate of the present invention, an adhesive layer is further formed on the void layer of the present invention (adhesive adhesive layer forming step). Specifically, for example, the adhesive layer may be formed by applying (coating) a pressure-sensitive adhesive or adhesive onto the void layer of the present invention. Moreover, you may form the said adhesive layer on the air gap layer of this invention by bonding the said adhesive tape side, such as the adhesive tape in which the said adhesive layer was laminated|stacked on a base material, on the air gap layer of this invention. In this case, base materials such as the pressure-sensitive adhesive tape may be left bonded as they are, or may be peeled off from the adhesive layer. In particular, as described above, by peeling off the substrate to obtain a (substrate-less) void layer-containing adhesive adhesive sheet without a substrate, the thickness can be significantly reduced and the increase in thickness of the device or the like can be suppressed. In the present invention, "adhesive" and "adhesive layer" refer to an agent or layer on the premise of re-peeling of an adherend, for example. In the present invention, "adhesive" and "adhesive layer" refer to an agent or layer that does not presuppose re-peeling of the adherend, for example. However, in the present invention, "adhesive" and "adhesive" are not necessarily clearly distinguishable, and "adhesive layer" and "adhesive layer" are not necessarily clearly distinguishable. In the present invention, the pressure-sensitive adhesive or adhesive forming the pressure-sensitive adhesive layer is not particularly limited, and, for example, a general pressure-sensitive adhesive or adhesive may be used. Examples of the pressure-sensitive adhesive or adhesive include polymer adhesives such as acrylic, vinyl alcohol, silicone, polyester, polyurethane, and polyether, and rubber adhesives. Moreover, adhesives etc. comprised with the water-soluble crosslinking agent of vinyl alcohol type polymers, such as glutaraldehyde, melamine, and oxalic acid, etc. are mentioned. As an adhesive, the above-mentioned adhesive is mentioned, for example. These pressure-sensitive adhesives and adhesives may be used alone or in combination (for example, by mixing or laminating). As described above, it is possible to protect the void layer from physical damage (especially scratches) by the adhesive layer. In addition, the adhesive layer is preferably excellent in pressure resistance so that the adhesive layer does not collapse even if it is a (substrate-less) adhesive sheet containing an air gap layer having no substrate, but is not particularly limited. In addition, the thickness of the adhesive layer is not particularly limited, but is, for example, 0.1 to 100 μm, 5 to 50 μm, 10 to 30 μm, or 12 to 25 μm.

The void layer of the present invention obtained in this way may be further laminated with another film (layer), for example, to form a laminated structure containing the above porous structure. In this case, in the laminated structure, each component may be laminated via, for example, the adhesive layer (adhesive or adhesive).

Lamination of the above components may be performed by, for example, continuous processing using a long film (so-called roll to roll, etc.) from the point of being efficient, and when the base material is a molded article or element, etc. You may laminate what performed batch processing.

Below, the method of forming the layered product of the present invention described above on a base material (resin film) will be explained using FIGS. 1 to 3 as an example for a continuous treatment step. 2 shows a step of bonding and winding a protective film after forming the void layer (silicon porous body), but in the case of laminating another functional film, the above method may be used, and other functional After coating and drying the film, it is also possible to bond the above-mentioned air gap layer formed into the film immediately before winding up. In addition, the film forming method shown is only an example, and is not limited to these.

In addition, the above-mentioned resin film may be sufficient as the said base material. In this case, the void layer of the present invention is obtained by forming the void layer on the substrate. Moreover, after forming the said void layer on the said base material, the void layer of this invention is also obtained by laminating|stacking the said void layer on the resin film mentioned above in description of the void layer of this invention.

The cross-sectional view of FIG. 1 schematically shows an example of a step in the method for manufacturing a laminate of the present invention in which the void layer, the intermediate layer, and the adhesive layer are laminated in the above order on the substrate (resin film). 1, the method for forming the void layer is a coating step (1) of forming a coated film by coating a sol particle liquid 20'' of a pulverized product of the gel compound on a base material (resin film) 10 , a drying step (2) in which the sol particle liquid 20'' is dried to form a coated film 20' after drying, and a chemical treatment (for example, cross-linking treatment) is applied to the coated film 20'. , chemical treatment step of forming the air gap layer 20 (eg, crosslinking step) (3), adhesive layer coating step of coating the adhesive layer 30 on the air gap layer 20 (adhesive adhesive layer formation step) (4) and an intermediate layer forming step (5) of forming the intermediate layer 22 by reacting the void layer 20 with the adhesive layer 30. In addition, the said chemical treatment process (crosslinking process) (3) corresponds to the said "gap layer formation process" in the manufacturing method of the laminated|multilayer film of this invention. In the figure, the intermediate layer forming step 5 (hereinafter sometimes referred to as "aging step") is a step of improving the strength of the air gap layer 20 (by causing a crosslinking reaction inside the air gap layer 20). crosslinking reaction step), and after the intermediate layer formation step (5), the void layer 20 is changed to the void layer 21 with improved strength. However, the present invention is not limited to this, and the void layer 20 does not have to be changed after the intermediate layer formation step (5), for example. Moreover, as mentioned above, the adhesive bonding layer formation process is not limited to application of an adhesive adhesive layer, and bonding of the adhesive tape which has an adhesive adhesive layer may be sufficient. By the above steps (1) to (5), as shown, the void layer 21, the intermediate layer 22, and the adhesive layer 30 are laminated in the above order on the resin film 10 A laminated film can be produced. However, the laminate of the present invention produced without the intermediate layer forming step (5) does not have to contain the intermediate layer. In addition, the manufacturing method of the laminated|multilayer film of this invention may or may not include processes other than the said process (1)-(5) suitably.

In the above coating step (1), the coating method of the sol particle liquid 20'' is not particularly limited, and a general coating method can be employed. Examples of the coating method include a slot die method, a reverse gravure coating method, a micro gravure method (micro gravure coating method), a dip method (dip coating method), a spin coating method, a brush coating method, a roll coating method, and a flexographic method. A printing method, a wire bar coating method, a spray coating method, an extrusion coating method, a curtain coating method, a reverse coating method, and the like are exemplified. Among these, the extrusion coating method, the curtain coating method, the roll coating method, the micro gravure coating method and the like are preferable from the viewpoints of productivity, smoothness of the coating film, and the like. The coating amount of the sol particle liquid 20'' is not particularly limited, and can be appropriately set, for example, so that the thickness of the void layer 20 is appropriate. The thickness of the void layer 21 is not particularly limited, and is as described above, for example.

In the drying step (2), the sol particle liquid 20'' is dried (that is, the dispersion medium contained in the sol particle liquid 20'' is removed), and the coated film after drying (precursor of the void layer) (20'). Conditions for the drying treatment are not particularly limited and are as described above.

Further, in the chemical treatment step (3), coating containing the catalyst or the catalyst generator (for example, a photoactive catalyst, a photocatalyst generator, a thermally active catalyst or a thermal catalyst generator) added before coating The film 20' is irradiated with light or heated to chemically bond (for example, cross-linked) the pulverized materials in the coated film 20' to form the void layer 20. Light irradiation or heating conditions in the chemical treatment step (3) are not particularly limited and are as described above.

Further, the adhesive layer coating step (adhesive adhesive layer forming step) (4) and the intermediate layer forming step (5) are performed. Adhesive layer coating process (adhesive adhesive layer formation process) (4) may include, for example, in addition to the process of applying the said adhesive, the heating process of heating the said adhesive after coating. For example, when the pressure-sensitive adhesive is a pressure-sensitive adhesive composition containing a polymer (for example, a (meth)acrylic polymer) and a crosslinking agent, the polymer may be crosslinked by the crosslinking agent in the heating step. The said heating process may also serve as the process of drying the said adhesive, for example. Moreover, for example, the said heating process may also serve as the said intermediate|middle layer formation process (5). Although the temperature of the said heating process is not specifically limited, They are 70-160 degreeC, 80-155 degreeC, and 90-150 degreeC, for example. Although the time of the said heating process is not specifically limited, It is 1 to 10 minutes, 1 to 7 minutes, or 2 to 5 minutes, for example.

Next, FIG. 2 schematically shows an example of a coating apparatus of a slot die method and a method of forming the above-mentioned void layer using the same. 2 is a sectional view, but hatches are omitted for ease of viewing.

As illustrated, each step in the method using this apparatus is performed while conveying the substrate 10 in one direction with a roller. The conveyance speed is not particularly limited, and is, for example, 1 to 100 m/min, 3 to 50 m/min, and 5 to 30 m/min.

First, the coating step (1) of coating the substrate 10 with the sol particle liquid 20'' is performed on the coating roll 102 while the substrate 10 is fed out and conveyed from the delivery roller 101, Then, it transfers to the drying process (2) in the oven zone 110. In the coating apparatus of FIG. 2, after coating process (1), before drying process (2), a preliminary drying process is implemented. The preliminary drying step can be performed at room temperature without heating. In the drying process (2), the heating means 111 is used. As the heating means 111, as described above, a hot air blower, a heating roll, a far-infrared heater, or the like can be used as appropriate. Further, for example, the drying process (2) may be divided into a plurality of processes, and the drying temperature may be increased as the drying process becomes later.

After the drying step (2), the chemical treatment step (3) is performed within the chemical treatment zone 120. In the chemical treatment step (3), for example, when the coated film 20' after drying contains a photoactive catalyst, light is emitted from lamps (light irradiation means) 121 placed above and below the substrate 10. investigate Alternatively, for example, when the coated film 20' after drying contains a thermally active catalyst, a hot air blower (heating means) is used instead of the lamp (light irradiation device) 121, and The base material 10 is heated with the hot air machine 121 arranged. By this crosslinking treatment, chemical bonding between the above-mentioned pulverized materials in the coating film 20' occurs, and the void layer 20 is cured and strengthened. Further, in this example, the chemical treatment step (3) is performed after the drying step (2), but as described above, at which stage of the production method of the present invention chemical bonding between the pulverized products is specifically limited. It doesn't work. For example, as described above, the drying step (2) may serve as the chemical treatment step (3). In addition, even when the chemical bonding occurs in the drying step (2), a chemical treatment step (3) may be further performed to further strengthen the chemical bonding between the pulverized materials. In addition, in the process prior to the drying process (2) (for example, the preliminary drying process, the coating process (1), the process of preparing a coating solution (eg suspension), etc.), the chemical bonding between the pulverized materials you can get up

After the chemical treatment step (3), a pressure-sensitive adhesive or adhesive is applied (coated) on the air gap layer 20 by the pressure-sensitive adhesive layer coating means 131a in the pressure-sensitive adhesive layer coating zone 130a, and the pressure-sensitive adhesive layer 30 The adhesive layer coating step (adhesive adhesive layer forming step) (4) to form is performed. In addition, as described above, instead of applying (coating) an adhesive or an adhesive, bonding (sticking) such as an adhesive tape having an adhesive layer 30 may be used.

In addition, the intermediate layer forming step (aging step) (5) is performed in the intermediate layer forming zone (aging zone) 130, and the void layer 20 and the adhesive layer 30 are reacted to form the intermediate layer 22. In addition, as described above, in this step, a crosslinking reaction occurs inside the void layer 20 to become the void layer 21 with improved strength. The intermediate layer forming step (aging step) 5 is, for example, by heating the air gap layer 20 and the adhesive layer 30 using a hot air blower (heating means) 131 disposed above and below the base material 10. may be carried out. The heating temperature, time, and the like are not particularly limited, but are as described above, for example.

And after the intermediate body formation process (aging process) (5), the laminated body in which the void layer 21 was formed on the base material 10 is wound up by the winding roll 105. In Fig. 2, the void layer 21 of the laminate is protected by being covered with a protective sheet drawn out from the roll 106. Here, instead of the above protective sheet, another layer formed of a long film may be laminated on the air gap layer 21 .

Fig. 3 schematically shows an example of a coating device of a microgravure method (microgravure coating method) and a method of forming the above-mentioned void layer using the same. In addition, although the figure is a sectional view, hatches are omitted for ease of viewing.

As shown in the figure, each step in the method using this apparatus is carried out while conveying the substrate 10 in one direction with a roller, similarly to FIG. 2 . The conveyance speed is not particularly limited, and is, for example, 1 to 100 m/min, 3 to 50 m/min, and 5 to 30 m/min.

First, the coating step (1) of coating the substrate 10 with the sol particle liquid 20'' is performed while the substrate 10 is discharged from the delivery roller 201 and conveyed. Coating of the sol particle liquid 20'' is performed using a liquid reservoir 202, a doctor (doctor knife) 203, and a micro gravure 204, as shown in the figure. Specifically, the sol particle liquid 20'' stored in the liquid reservoir 202 is adhered to the surface of the micro gravure 204, and while the doctor 203 controls it to a predetermined thickness, the micro gravure (204) is coated on the surface of the substrate (10). In addition, micro gravure 204 is an example, and it is not limited to this, You may use other arbitrary coating means.

Next, the drying process (2) is performed. Specifically, as shown in the figure, the base material 10 coated with the sol particle liquid 20'' is transported in the oven zone 210 and heated by a heating means 211 in the oven zone 210. The sol particle liquid 20'' is dried. The heating means 211 may be the same as that of FIG. 2, for example. Moreover, for example, by dividing the oven zone 210 into a plurality of sections, the drying step (2) may be divided into a plurality of steps, and the drying temperature may be increased as the later drying step becomes. After the drying step (2), the chemical treatment step (3) is performed within the chemical treatment zone 220. In the chemical treatment step (3), for example, when the coated film 20' after drying contains a photoactive catalyst, light is emitted from lamps (light irradiation means) 221 disposed above and below the substrate 10. investigate Alternatively, for example, when the coated film 20' after drying contains a thermally active catalyst, a hot air blower (heating means) is used instead of the lamp (light irradiation device) 221, and The base material 10 is heated by the arranged hot air machine (heating means) 221 . By this crosslinking treatment, chemical bonding between the above-mentioned pulverized materials in the coating film 20' occurs, and the void layer 20 is formed.

After the chemical treatment step (3), in the adhesive layer coating zone 230a, the adhesive or adhesive is applied (coated) on the air gap layer 20 by the adhesive layer coating means 231a, and the adhesive layer 30 The adhesive layer coating step (adhesive adhesive layer forming step) (4) to form is performed. In addition, as described above, instead of applying (coating) an adhesive or adhesive, bonding (sticking) such as an adhesive tape having an adhesive layer 30 may be used.

In addition, the intermediate layer forming step (aging step) (5) is performed in the intermediate layer forming zone (aging zone) 230, and the void layer 20 and the adhesive layer 30 are reacted to form the intermediate layer 22. Also, as described above, in this step, the void layer 20 becomes the void layer 21 with improved strength. The intermediate layer forming step (aging step) 5 is, for example, by heating the air gap layer 20 and the adhesive layer 30 using a hot air blower (heating means) 231 disposed above and below the base material 10. may be carried out. The heating temperature, time, and the like are not particularly limited, but are as described above, for example.

And after intermediate body formation process (aging process) (5), the laminated|multilayer film in which the void layer 21 was formed on the base material 10 is wound up by the winding roll 251. After that, another layer may be laminated on the laminated film, for example. Moreover, before winding up the said laminated film with the winding roll 251, you may laminate|stack another layer on the said laminated film, for example.

Example

Next, examples of the present invention will be described. However, the present invention is not limited to the following examples.

Incidentally, in the following Reference Examples, Examples and Comparative Examples, the number of copies (relative usage amount) of each substance is a mass part (parts by weight) unless otherwise specified.

In addition, in the following reference examples, examples and comparative examples, the storage modulus at 23 ° C. of the adhesive layer, the gel fraction of the adhesive layer, the thickness of each layer, and the weight average molecular weight of the sol powder of the adhesive layer are, respectively, the following It was measured by the measuring method.

(Method of measuring storage modulus)

The storage elastic modulus at 23 degreeC of the adhesive layer was measured by the following method using the viscoelasticity measuring apparatus ARES (trade name of TA Instruments). That is, first, the same sheet (layer) as the adhesive layer in each of the following Reference Examples, Examples and Comparative Examples was molded except for being in the form of a sheet having a thickness of 2 mm. The sheet was cut out according to a parallel plate having a diameter of 25 mm, and it was set as a measurement sample. This measurement sample was attached to the chuck of the viscoelasticity measuring device ARES. Then, the temperature was raised from -70 °C to 150 °C at a heating rate of 5 °C/min while strain was applied at a cycle of 1 Hz, and the storage modulus at 23 °C was measured.

(Method for measuring gel fraction of adhesive layer)

Measurement samples prepared in the same way as the adhesive layer in each of the following reference examples, examples, and comparative examples (each adhesive composition was coated and then heated and dried) were prepared. This measurement sample (initial weight W1) was immersed in ethyl acetate and left at room temperature for 1 week, then the insoluble content was taken out, the dried weight (W2) was measured, and the gel fraction was calculated based on the following formula (II) did

Gel fraction (% by weight) = (W2 / W1) × 100 (II)

In addition, in the adhesive layer in each of the reference examples, examples and comparative examples below, it is presumed that the polymer (acrylic polymer) is crosslinked with a crosslinking agent and a crosslinked structure is formed by heating and drying the coated adhesive, The cross-linked structure has not been identified.

(Thickness measurement method)

It was measured using a dial gauge.

(Method for measuring weight average molecular weight of sol powder of adhesive layer)

From the molecular weight distribution curve measured by the gel permeation chromatography (GPC) method, the ratio (weight percentage) of the weight average molecular weight of the sol powder to the low molecular weight component having a molecular weight of 10,000 or less was calculated. Specifically, first, a measurement sample prepared by the same method as that of the adhesive layer in each of the following reference examples, examples, and comparative examples (after coating each adhesive composition, and then heating and drying) was prepared. What added 10 ml of tetrahydrofuran (THF) to 200 mg of this measurement sample was allowed to stand for 20 hours and filtered through a 0.45 μm membrane filter. Thereafter, the obtained filtrate was subjected to GPC measurement under the following measuring device and measuring conditions, and as described above, from the molecular weight distribution curve, the ratio of the weight average molecular weight of the sol powder to the low molecular weight component having a molecular weight of 10,000 or less. (weight percentage) was calculated.

GPC measuring device: Trade name "AQCUITY APC" (manufactured by Water)

Column: Trade name "G7000HxL+GMHxL+GMHxL" (manufactured by Tosoh Corporation)

Eluent: tetrahydrofuran (THF)

Flow rate: 0.8 ml/min

Detector: Differential Refractometer (RI)

Column temperature (measurement temperature): 40 ℃

Injection volume: 100 μl

Standard: Polystyrene

[Reference Example 1: Preparation of coating solution for forming void layer]

First, gelation of the silicon compound (step (1) below) and aging step (step (2) below) were performed to prepare a gel (silicone porous body) having a porous structure. After that, the following (3) shape control step, (4) solvent substitution step, and (5) gel grinding step were performed to obtain a coating solution for forming a void layer (liquid containing pulverized gel). In addition, in this reference example, the following (3) shape control process was implemented as a process different from the following process (1), as described below. However, the present invention is not limited to this, and for example, the following (3) shape control step may be performed during the following step (1).

(1) Gelation of silicon compound

9.5 kg of MTMS, a precursor of a silicon compound, was dissolved in 22 kg of DMSO. 5 kg of a 0.01 mol/L oxalic acid aqueous solution was added to the mixture, and stirred at room temperature for 120 minutes to hydrolyze MTMS to produce tris(hydroxy)methylsilane.

After adding 3.8 kg of 28% aqueous ammonia and 2 kg of pure water to 55 kg of DMSO, the mixed solution subjected to the hydrolysis treatment was further added and stirred at room temperature for 60 minutes. The liquid after stirring for 60 minutes was poured into a stainless steel container having a length of 30 cm × a width of 30 cm × a height of 5 cm, and tris (hydroxy) methylsilane was gelated and a gel-like silicon compound was obtained by allowing to stand still at room temperature.

(2) aging process

The gelled silicon compound obtained by performing the gelation treatment was incubated at 40°C for 20 hours, subjected to an aging treatment, and the gel of the rectangular parallelepiped mass was obtained. Since the amount of DMSO (a high-boiling solvent with a boiling point of 130°C or higher) used in the raw material was about 83% by weight of the total amount of the raw material, it was evident that this gel contained 50% by weight or more of the high-boiling solvent with a boiling point of 130°C or higher. . In addition, since the usage amount of MTMS (monomer as a structural unit of gel) in the raw material of this gel was about 8% by weight of the total raw material, the boiling point generated by hydrolysis of the monomer (MTMS) as a structural unit of gel It was clear that the content of the solvent (methanol in this case) below 130°C was 20% by weight or less.

(3) shape control process

Water as a substitution solvent was poured onto the gel synthesized in the above step (1) (2) in the 30 cm x 30 cm x 5 cm stainless steel container. Next, a cutting blade of a cutting jig was slowly inserted into the gel in the stainless steel container from above, and the gel was cut into a cuboid having a size of 1.5 cm x 2 cm x 5 cm.

(4) Solvent replacement process

Next, the solvent replacement step was performed in the following manner (4-1) to (4-3).

(4-1) After the above "(3) shape control step", the silicon gel compound was immersed in water eight times the weight of the silicon gel compound, and stirred slowly for 1 hour so that only water convexed. After 1 h, the water was exchanged with the same amount of water, and the mixture was further stirred for 3 h. Further, water was again exchanged after that, and then heated at 60°C for 3 hours while slowly stirring.

(4-2) After (4-1), the water was replaced with isopropyl alcohol of 4 times the weight of the above-mentioned gelled silicon compound, and the mixture was heated at 60°C for 6 hours while stirring in the same way.

(4-3) After (4-2), isopropyl alcohol is replaced with isobutyl alcohol of the same weight, heated at 60°C for 6 h, and the solvent contained in the gel-like silicon compound is replaced with isobutyl alcohol. did In the above manner, the gel for producing a void layer of the present invention was prepared.

(5) Gel crushing process

Regarding the gel (gelled silicon compound) after the above (4) solvent replacement step, in the first grinding step, continuous emulsion dispersion (made by Taiheiyo Qigongsha, Milder MDN304 type), and in the second grinding step, high-pressure medialess grinding ( pulverization was performed in two stages of Starburst HJP-25005 type manufactured by Sugino Machinery Co., Ltd.). In this grinding treatment, 26.6 kg of isobutyl alcohol was added and weighed to 43.4 kg of the gel containing the solvent-substituted gel-like silicon compound as a solvent, and then the first grinding step was circular grinding for 20 minutes, and the second grinding step was grinding Grinding was performed at a pressure of 100 MPa. In this way, an isobutyl alcohol dispersion (liquid containing pulverized gel) in which nanometer-sized particles (a pulverized gel) was dispersed was obtained. Further, 224 g of a 1.5% concentration solution of methyl isobutyl ketone of WPBG-266 (trade name, manufactured by Wako) was added to 3 kg of the above-mentioned pulverized gel-containing solution, and further, bis (trimethoxysilyl) ethane (manufactured by TCI) After adding 67.2 g of a 5% concentration solution of methyl isobutyl ketone, 31.8 g of N,N-dimethylformamide was added and mixed to obtain a coating solution.

In the above manner, a coating solution for forming a void layer (liquid containing pulverized gel) of this reference example (Reference Example 1) was prepared. Further, the peak pore diameter of the pulverized gel (fine pore particles) in the coating solution for forming a void layer (liquid containing pulverized gel) was measured by the method described above and found to be 12 nm.

[Reference Example 2: Formation of adhesive layer]

The adhesive layer of this reference example (reference example 2) was formed in the order of the following (1) to (3).

(1) Preparation of acrylic polymer solution

90.7 parts of butyl acrylate, 6 parts of N-acryloylmorpholine, 3 parts of acrylic acid, 0.3 part of 2-hydroxybutyl acrylate, and , As a polymerization initiator, 0.1 part by weight of 2,2'-azobisisobutyronitrile was put together with 100 g of ethyl acetate. Next, while gently stirring the content in the four-necked flask, nitrogen gas was introduced and purged with nitrogen. Thereafter, while maintaining the liquid temperature in the four-necked flask at around 55°C, a polymerization reaction was carried out for 8 hours to prepare an acrylic polymer solution.

(2) Preparation of acrylic pressure-sensitive adhesive composition

With respect to 100 parts of solid content of the acrylic polymer solution obtained in the above (1), isocyanate crosslinking agent (trade name "Colonate L" manufactured by Nippon Polyurethane Industries, Ltd., an adduct of tolylene diisocyanate of trimethylolpropane) 0.2 part, benzoyl peroxide An acrylic pressure-sensitive adhesive composition (acrylic pressure-sensitive adhesive solution) containing 0.3 part of (trade name "Nipper BMT" manufactured by Nippon Oil Co., Ltd.) and 0.2 part of γ-glycidoxypropylmethoxysilane (trade name "KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) prepared.

(3) Formation of adhesive layer

The acrylic pressure-sensitive adhesive composition obtained in the above (2) was coated on one side of a silicone-treated polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness: 38 μm), and the thickness of the pressure-sensitive adhesive layer after drying was 12 μm. It was applied as much as possible and dried at 150°C for 3 minutes to form an adhesive layer (adhesive adhesive layer). The storage elastic modulus G' at 23°C of this pressure-sensitive adhesive layer (adhesive adhesive layer) was 1.3 × 10 ⁵ .

[Reference Example 3: Formation of adhesive layer]

The adhesive layer of this reference example (reference example 3) was formed in the order of the following (1) to (3).

(1) Preparation of acrylic polymer solution

96.9 parts of butyl acrylate, 3 parts of acrylic acid, 0.1 part of 2-hydroxyethyl acrylate, and 2,2'-azo as a polymerization initiator were placed in a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet pipe, and condenser. 0.1 part of bisisobutyronitrile was put together with 100 g of ethyl acetate. Next, while gently stirring the content in the four-necked flask, nitrogen gas was introduced and purged with nitrogen. Thereafter, a polymerization reaction was carried out for 8 hours while maintaining the liquid temperature in the four-necked flask at around 55°C to prepare an acrylic polymer solution.

(2) Preparation of acrylic pressure-sensitive adhesive composition

Based on 100 parts of solid content of the acrylic polymer solution obtained in (1) above, isocyanate crosslinking agent (trade name "Colonate L" manufactured by Nippon Polyurethane Industries, Ltd., an adduct of tolylene diisocyanate of trimethylolpropane) 0.5 part, benzoyl peroxide 0.2 part of (trade name "Nipper BMT" manufactured by Nippon Oil & Gas Co., Ltd.) and 0.2 part of γ-glycidoxypropylmethoxysilane (trade name "KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) were blended to obtain a solution of an acrylic pressure-sensitive adhesive composition. prepared.

(3) Formation of adhesive layer

The solution of the acrylic pressure-sensitive adhesive composition obtained in the above (2) was applied to one side of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness: 38 μm) subjected to silicone treatment, and the thickness of the pressure-sensitive adhesive layer after drying was 20 It applied so that it might become micrometer, and dried at 150 degreeC for 3 minutes, and the adhesive layer (adhesive adhesive layer) was formed. The storage elastic modulus G' at 23°C of this pressure-sensitive adhesive layer (adhesive adhesive layer) was 1.1 × 10 ⁵ .

[Reference Example 4: Formation of adhesive layer]

The adhesive layer of this reference example (reference example 4) was formed in the order of the following (1) to (3).

(1) Preparation of acrylic polymer solution

77 parts of butyl acrylate, 20 parts of phenoxyethyl acrylate, 2 parts of N-vinyl-2-pyrrolidone, 0.5 part of acrylic acid, 4 - 0.5 part of hydroxybutyl acrylate and 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator were put together with 100 parts of ethyl acetate. Next, while gently stirring the content in the four-necked flask, nitrogen gas was introduced and purged with nitrogen. Thereafter, a polymerization reaction was carried out for 8 hours while maintaining the liquid temperature in the four-necked flask at around 55°C to prepare an acrylic polymer solution.

(2) Preparation of acrylic pressure-sensitive adhesive composition

With respect to 100 parts of the solid content of the solution of the acrylic polymer obtained in the above (1), isocyanate crosslinking agent (trade name "Takenate D160N" manufactured by Mitsui Chemicals, Inc., trimethylolpropane hexamethylene diisocyanate) 0.1 part, benzoyl peroxide (manufactured by Nippon Yuji Co., Ltd.) 0.3 part of (trade name "Nipper BMT") and 0.2 part of γ-glycidoxypropylmethoxysilane (trade name "KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) were blended to prepare a solution of an acrylic pressure-sensitive adhesive composition.

(3) Formation of adhesive layer

The solution of the acrylic pressure-sensitive adhesive composition obtained in the above (2) was applied to one side of a polyethylene terephthalate film (separator film: manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., trade name "MRF38") treated with a silicone-based release agent, and incubated at 150 ° C. for 3 minutes After drying, a pressure-sensitive adhesive layer (adhesive adhesive layer) having a thickness of 20 μm was formed on the surface of the separator film. The storage elastic modulus G' at 23°C of this pressure-sensitive adhesive layer (adhesive adhesive layer) was 1.1 × 10 ⁵ .

[Reference Example 5: Formation of adhesive layer]

The adhesive layer of this reference example (reference example 5) was formed in the order of the following (1) to (3).

(1) Preparation of prepolymer composition

To a monomer mixture composed of 68 parts of 2-ethylhexyl acrylate, 14.5 parts of N-vinyl-2-pyrrolidone, and 17.5 parts of 2-hydroxyethyl acrylate, a photopolymerization initiator (trade name "Irgacure 184", manufactured by BASF) After blending 0.035 part and photopolymerization initiator (trade name "Irgacure 651", BASF) 0.035 part, when the viscosity (BH viscometer No.5 rotor, 10 rpm, measurement temperature 30 ° C.) becomes about 20 Pa s was irradiated with ultraviolet rays to obtain a prepolymer composition in which a part of the monomer components were polymerized.

(2) Preparation of acrylic pressure-sensitive adhesive composition

To the prepolymer composition obtained in (1) above, 0.150 part of hexanedioldiacrylate (HDDA) and 0.3 part of a silane coupling agent (trade name "KBM-403", Shin-Etsu Chemical Co., Ltd.) were added and mixed to obtain an acrylic pressure-sensitive adhesive composition.

(3) Formation of adhesive layer

The acrylic pressure-sensitive adhesive composition obtained in the above (2) was coated on one side of a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness: 50 μm) subjected to silicone treatment, and the thickness of the pressure-sensitive adhesive layer after drying was 25 μm. Then, a polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., thickness: 38 μm) subjected to silicone treatment was formed on the coating layer to cover the coating layer and to block oxygen. Next, this laminate was irradiated with an ultraviolet ray having an illuminance of 5 mW/cm 2 for 300 seconds by a black light (manufactured by Toshiba) from the upper surface (MRF38 side) of the laminate. Further, a drying treatment was performed for 2 minutes in a dryer at 90°C, and the remaining monomer was volatilized to form an adhesive layer (adhesive adhesive layer). The storage elastic modulus G' at 23°C of this pressure-sensitive adhesive layer (adhesive adhesive layer) was 1.1 × 10 ⁵ .

[Reference Example 6: Formation of adhesive layer]

The adhesive layer of this reference example (reference example 6) was formed by the procedure of the following (1) to (3).

(1) Preparation of acrylic polymer solution

99 parts of butyl acrylate, 1 part of 4-hydroxybutyl acrylate, and 2,2'-azobisisobutyro as a polymerization initiator in a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser 0.1 part of nitrile was put together with 100 parts of ethyl acetate. Next, while gently stirring the content in the four-necked flask, nitrogen gas was introduced and purged with nitrogen. Thereafter, while maintaining the liquid temperature in the four-necked flask at around 55°C, a polymerization reaction was carried out for 8 hours to prepare an acrylic polymer solution.

(2) Preparation of acrylic pressure-sensitive adhesive composition

Based on 100 parts of the solid content of the acrylic polymer solution obtained in the above (1), isocyanate crosslinking agent (trade name "Takenate D110N" manufactured by Mitsui Takeda Chemical Co., Ltd., trimethylolpropanexylylene diisocyanate) 0.1 part, benzoyl peroxide (Nippon Yuji Co., Ltd.) 0.1 part of manufactured product name "Nyper BMT") and 0.2 part of γ-glycidoxypropyl methoxysilane (trade name "KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) were blended to prepare a solution of an acrylic pressure-sensitive adhesive composition.

(3) Formation of adhesive layer

The solution of the acrylic pressure-sensitive adhesive composition obtained in the above (2) was applied to one side of a polyethylene terephthalate film (separator film: manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., trade name "MRF38") treated with a silicone-based release agent, and incubated at 150 ° C. for 3 minutes After drying, a pressure-sensitive adhesive layer (adhesive adhesive layer) having a thickness of 20 μm was formed on the surface of the separator film. The storage elastic modulus G' at 23°C of this pressure-sensitive adhesive layer (adhesive adhesive layer) was 8.2 × 10 ⁴ .

[Reference Example 7: Formation of adhesive layer]

The adhesive layer of this reference example (Reference Example 7) was formed in the order of the following (1) to (3).

(1) Preparation of acrylic polymer solution

90.7 parts of butyl acrylate, 6 parts of N-acryloylmorpholine, 3 parts of acrylic acid, 0.3 part of 2-hydroxybutyl acrylate, and , As a polymerization initiator, 0.1 part by weight of 2,2'-azobisisobutyronitrile was put together with 100 g of ethyl acetate. Next, while gently stirring the content in the four-necked flask, nitrogen gas was introduced and purged with nitrogen. Thereafter, while maintaining the liquid temperature in the four-necked flask at around 55°C, a polymerization reaction was carried out for 8 hours to prepare an acrylic polymer solution.

(2) Preparation of acrylic pressure-sensitive adhesive composition

Based on 100 parts of solid content of the acrylic polymer solution obtained in (1) above, isocyanate crosslinking agent (trade name "Colonate L" manufactured by Nippon Polyurethane Industry Co., Ltd., an adduct of tolylene diisocyanate of trimethylolpropane) 0.15 part, benzoyl peroxide An acrylic pressure-sensitive adhesive composition (acrylic pressure-sensitive adhesive solution) containing 0.2 part of (trade name "Nipper BMT" manufactured by Nippon Oil Co., Ltd.) and 0.2 part of γ-glycidoxypropylmethoxysilane (trade name "KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) prepared.

(3) Formation of adhesive layer

The solution of the acrylic pressure-sensitive adhesive composition obtained in the above (2) was applied to one side of a polyethylene terephthalate film (separator film: manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., trade name "MRF38") treated with a silicone-based release agent, and incubated at 150 ° C. for 3 minutes After drying, an adhesive layer (adhesive adhesive layer) having a thickness of 75 μm was formed on the surface of the separator film. The storage modulus G' of this pressure-sensitive adhesive layer (adhesive adhesive layer) at 23°C was 1.0 × 10 ⁵ .

[Reference Example 8: Formation of adhesive layer]

The adhesive layer of this reference example (reference example 8) was formed in the order of the following (1) to (3).

(1) Preparation of acrylic polymer solution

95 parts of butyl acrylate, 5 parts of acrylic acid, and 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator were added to a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet pipe, and a condenser, and ethyl acetate It was put together with 100 g. Next, the content in the four-necked flask was purged with nitrogen by introducing nitrogen gas while gently stirring. After that, the liquid temperature in the four-necked flask was maintained at around 55°C to carry out polymerization reaction for 8 hours, and then the liquid temperature in the flask was raised to 70°C and reaction was carried out for 2 hours to prepare an acrylic polymer solution.

(2) Preparation of acrylic pressure-sensitive adhesive composition

Based on 100 parts of solid content of the acrylic polymer solution obtained in the above (1), isocyanate crosslinking agent (trade name "Colonate L" manufactured by Nippon Polyurethane Industries, Ltd., an adduct of tolylene diisocyanate of trimethylolpropane) 0.7 part, benzoyl peroxide 0.2 part of (trade name "Nipper BMT" manufactured by Nippon Oil & Gas Co., Ltd.) and 0.2 part of γ-glycidoxypropylmethoxysilane (trade name "KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) were blended to obtain a solution of an acrylic pressure-sensitive adhesive composition. prepared.

(3) Formation of adhesive layer

The solution of the acrylic pressure-sensitive adhesive composition obtained in the above (2) was applied to one side of a polyethylene terephthalate film (separator film: manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., trade name "MRF38") treated with a silicone-based release agent, and incubated at 150 ° C. for 3 minutes After drying, an adhesive layer (adhesive adhesive layer) having a thickness of 75 μm was formed on the surface of the separator film. The storage modulus G' of this pressure-sensitive adhesive layer (adhesive adhesive layer) at 23°C was 7.7 × 10 ⁴ .

[Example 1]

The high-porosity layer-forming coating solution prepared in Reference Example 1 was coated and dried on an acrylic substrate to form a void layer (porosity: 59% by volume) with a film thickness of about 850 nm. Next, UV irradiation (300 mJ) was performed from the surface of the void layer. Thereafter, the adhesive having a thickness of 12 μm obtained in Reference Example 2 was bonded onto the surface of the void layer, and aging was performed at 60° C. for 20 h to prepare a laminate of this example.

Further, the laminate of this example prepared as described above was put into an oven at 85°C and 85% RH, and a 500-h heating and humidification durability test was conducted. After the heating and humidification durability test, the degree of filling of the voids of the void layer was confirmed by SEM, and the remaining percentage of voids was calculated. The results are shown in Table 1.

[Example 2]

Except for using the pressure-sensitive adhesive obtained in Reference Example 3 instead of the pressure-sensitive adhesive of Reference Example 2, the same operation as in Example 1 was carried out to produce a laminate of this example. Further, a heat and humidification durability test was conducted in the same manner as in Example 1, and the remaining percentage of porosity was calculated. The results are shown in Table 1.

[Example 3]

Except for using the pressure-sensitive adhesive obtained in Reference Example 4 instead of the pressure-sensitive adhesive of Reference Example 2, the same operation as in Example 1 was carried out to produce a laminate of this example. Further, a heat and humidification durability test was conducted in the same manner as in Example 1, and the remaining percentage of porosity was calculated. The results are shown in Table 1.

[Example 4]

Except for using the pressure-sensitive adhesive obtained in Reference Example 5 instead of the pressure-sensitive adhesive of Reference Example 2, the same operation as in Example 1 was carried out to produce a laminate of this example. Further, a heat and humidification durability test was conducted in the same manner as in Example 1, and the remaining percentage of porosity was calculated. The results are shown in Table 1.

[Example 5]

A laminate of this example was manufactured by performing the same operation as in Example 1, except that the thickness of the adhesive layer formed with the pressure-sensitive adhesive of Reference Example 2 was 5 μm. Further, a heat and humidification durability test was conducted in the same manner as in Example 1, and the remaining percentage of porosity was calculated. The results are shown in Table 1.

[Example 6]

Except for using the pressure-sensitive adhesive obtained in Reference Example 7 instead of the pressure-sensitive adhesive of Reference Example 2, the same operation as in Example 1 was carried out to produce a laminate of this example. Further, a heat and humidification durability test was conducted in the same manner as in Example 1, and the remaining percentage of porosity was calculated. The results are shown in Table 1.

[Comparative Example 1]

Except for using the pressure-sensitive adhesive obtained in Reference Example 6 instead of the pressure-sensitive adhesive of Reference Example 2, the same operation as in Example 1 was carried out to produce a laminate of this comparative example. Further, a heat and humidification durability test was conducted in the same manner as in Example 1, and the remaining percentage of porosity was calculated. The results are shown in Table 1.

[Comparative Example 2]

A laminate of this comparative example was produced by performing the same operations as in Example 1, except that an epoxy adhesive semi-cured by UV (ultraviolet ray irradiation) was used instead of the pressure-sensitive adhesive of Reference Example 2. Further, a heat and humidification durability test was conducted in the same manner as in Example 1, and the remaining percentage of porosity was calculated. The results are shown in Table 1.

[Comparative Example 3]

Except for using the pressure-sensitive adhesive obtained in Reference Example 8 instead of the pressure-sensitive adhesive of Reference Example 2, the same operation as in Example 1 was carried out to produce a laminate of this comparative example. Further, a heat and humidification durability test was conducted in the same manner as in Example 1, and the remaining percentage of porosity was calculated. The results are shown in Table 1.

Moreover, about the laminated body of Examples 1-6 and Comparative Examples 1-3, the adhesive force was measured by the above-mentioned measuring method, respectively. In addition, the storage elastic modulus at 23 ° C. of the adhesive layer, the gel fraction of the adhesive layer, the thickness of the intermediate layer, the thickness of the adhesive layer, and the weight average molecular weight of the sol powder of the adhesive layer were measured by the above-described measurement method. Further, from the SEM image of the laminate after the durability test, void points were binarized to calculate the void remaining ratio. Their results are shown in Table 1 together.

As shown in Table 1, in the laminates of Examples 1 to 6, both the adhesive strength and the difficulty of penetrating the pressure-sensitive adhesive (adhesive adhesive layer) into the voids were compatible. In contrast, in the laminates of Comparative Examples 1 to 3, the adhesive (adhesive adhesive layer) permeated into the voids of the void layer, and the void remaining ratio of the void layer after the durability test was low.

As described above, according to the present invention, it is possible to provide a laminate, an optical member, and an optical device of a void layer and an adhesive layer, which have both adhesive strength or adhesive strength and difficulty in penetrating the pressure-sensitive adhesive or adhesive into the void. The use of the present invention is not particularly limited. For example, the optical device of the present invention is not particularly limited, and examples thereof include an image display device and a lighting device. As said image display device, a liquid crystal display, an organic electroluminescence display, a micro LED display etc. are mentioned, for example. As said lighting device, organic EL lighting etc. are mentioned, for example. In addition, the use of the laminate of the present invention is not limited to the optical member and optical device of the present invention, and is arbitrary, and can be used for a wide range of uses.

This application claims priority based on Japanese Patent Application No. 2017-190746, filed on September 29, 2017, and Japanese Patent Application No. 2018-180954, filed on September 26, 2018, the entire disclosure of which is introduced here

10: materials
20: void layer
20': coating film (after drying)
20'': sol particle solution
21: void layer with improved strength
22: middle layer
30: adhesive layer
101: sending roller
102: coating roll
110: oven zone
111: hot air blower (heating means)
120: chemical treatment zone
121 Lamp (light irradiation means) or hot air blower (heating means)
130a: adhesive layer coating zone
130: intermediate formation zone
131a: adhesive layer coating means
131: hot air blower (heating means)
105: winding roll
106: roll
201: sending roller
202: liquid reservoir
203: Doctor (Doctor Knife)
204: micro gravure
210: oven zone
211: heating means
220: chemical treatment zone
221: light irradiation means or heating means
230a: adhesive layer coating zone
230: intermediate formation zone
231a: point adhesive layer coating means
231: hot air blower (heating means)
251: winding roll

Claims (17)

A gap layer, a point adhesive layer, and an intermediate layer formed by combining a part of the gap layer and a part of the point adhesive layer,
The porosity of the void layer is 35% by volume or more,
The storage modulus at 23 ° C. of the adhesive layer is 1.0 × 10 ⁵ or more, characterized in that the laminate. According to claim 1,
After a heating and humidification durability test maintained at a temperature of 85°C and a relative humidity of 85% for 500 h, the void residual ratio of the void layer is 50% by volume or more before the heating and humidification durability test. According to claim 2,
A laminate in which the void remaining ratio of the void layer after the heating and humidification durability test is more than 50% and 99% or less of the void remaining ratio when only the void layer is subjected to the heating and humidification durability test. According to claim 2,
A laminate in which the thickness of the intermediate layer is 200 nm or less. According to claim 4,
After the heat and humid durability test, the rate of increase in the thickness of the middle layer is 500% or less with respect to the thickness of the middle layer before the heat and humid durability test. According to claim 1,
The pressure-sensitive adhesive layer is formed by a pressure-sensitive adhesive containing a (meth)acrylic polymer and a crosslinking agent,
The gel fraction of the adhesive layer is 70% or more,
The thickness of the adhesive layer is 2 to 50 μm,
A layered product in which the adhesive layer satisfies the following formula (I).
[(100 - X) / 100] × Y ≤ 10 (I)
In the formula (I),
X is the gel fraction (%) of the adhesive layer,
Y is the thickness (μm) of the adhesive layer. According to claim 6,
In the molecular weight measurement of the point adhesive layer by the gel permeation chromatography method,
The weight average molecular weight of the sol powder of the adhesive layer is 50,000 to 500,000,
A laminate in which the content of a low molecular weight component having a molecular weight of 10,000 or less in the sol powder of the adhesive layer is 20% by weight or less. According to claim 6,
In the adhesive layer, the (meth)acrylic polymer is crosslinked with the crosslinking agent to form a crosslinked structure. A gap layer, a point adhesive layer, and an intermediate layer formed by combining a part of the gap layer and a part of the point adhesive layer,
The porosity of the void layer is 35% by volume or more,
The pressure-sensitive adhesive layer is formed by a pressure-sensitive adhesive containing a (meth)acrylic polymer and a crosslinking agent,
The (meth)acrylic polymer, as a monomer component, contains 3 to 10% by weight of a heterocyclic acrylic monomer, 0.5 to 5% by weight of (meth)acrylic acid, 0.05 to 2% by weight of hydroxyalkyl (meth)acrylate, and an alkyl ( A (meth)acrylic polymer having a weight average molecular weight of 1,500,000 to 2,800,000 obtained by polymerizing 83 to 96.45% by weight of meth)acrylate,
The storage modulus at 23 ° C. of the adhesive layer is 1.0 × 10 ⁵ or more, characterized in that the laminate. According to claim 9,
After a heating and humidification durability test maintained at a temperature of 85°C and a relative humidity of 85% for 500 h, the void residual ratio of the void layer is 50% by volume or more before the heating and humidification durability test. According to claim 9,
A laminate in which the thickness of the intermediate layer is 200 nm or less. According to claim 9,
After a heating and humidification durability test maintained at a temperature of 85°C and a relative humidity of 85% for 500 h, the increase rate of the thickness of the middle layer is 500% or less with respect to the thickness of the middle layer before the heat and humidification durability test. According to claim 9,
In the adhesive layer, the (meth)acrylic polymer is crosslinked with the crosslinking agent to form a crosslinked structure. According to any one of claims 1 to 13,
A laminate in which the refractive index of the void layer is 1.25 or less. According to any one of claims 1 to 13,
A laminate in which the adhesive layer is formed of an optical acrylic pressure-sensitive adhesive having a total light transmittance of 85% or more and a haze of 3% or less. An optical member comprising the laminate according to any one of claims 1 to 13. An optical device comprising the optical member according to claim 16.

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