JP2011110820A - Method for producing laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a laminate by curing a curable resin composition held and sealed between a pair of basal plates, where, at releasing reduced-pressure atmosphere, the diameter of voids remaining in the curable resin composition layer in the sealed space can be made smaller, and thereby the time required until the voids remaining in the curable resin composition layer disappear can be shortened. <P>SOLUTION: In the method, formation of a laminate precursor of the curable resin composition held between a pair of basal plates is conducted in a reduced-pressure atmosphere satisfying conditions that the atmospheric pressure P is 0.1-1,000 Pa and the pressure gradient ΔP/ΔT (Pa/sec) under the atmospheric pressure is -1 (Pa/sec)≤ΔP/ΔT≤0 (Pa/sec); and the amount ΔP (Pa) of pressure variation, from the formation of the laminate precursor until immediately before when the laminate precursor is put in a second pressure atmosphere higher in atmospheric pressure than that of the reduced-pressure atmosphere, is held at: -1 (Pa)≤ΔP≤2 (Pa). Further, the laminate precursor is pressurized when it is put in the second pressure atmosphere. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a method for producing a laminate having a pair of substrates and a cured product layer of a curable resin composition existing between the pair of substrates.
The laminate produced by the method of the present invention includes laminated glass, a front panel plate of an image display device, more specifically, a liquid crystal display device (LCD), an EL (electroluminescence) display device such as an organic EL or an inorganic EL, It is suitable for uses such as a front panel plate of a flat panel display (FPD) such as a plasma display device and an electronic ink type image display device, a thin-layer solar cell device, a protective plate for a touch panel, and the like.

Laminated glass with a pair of glass substrates integrated through an adhesive layer is used as a windshield for automobiles because broken glass fragments adhere to the film and do not scatter, and it is difficult to penetrate and has excellent strength. It is used as a window glass (safety glass, security glass) (see Patent Documents 1 and 2).
From the viewpoint of preventing damage to the liquid crystal panel and preventing light reflection, a liquid crystal display device in which a front panel in which a transparent intermediate film is sealed between a transparent protective plate and a polarizing plate is provided on the front surface of the liquid crystal panel is known. (See Patent Document 3).
Further, a solar cell module having a solar cell device sealed with a sealing material such as a resin between a transparent front surface material and a back surface material serving as a light receiving surface is known (see Patent Document 4).
Thus, there is a demand in various technical fields for a laminate having a pair of substrates and a cured product layer of a curable resin composition existing between the pair of substrates.

Many methods for producing such a laminate have been proposed, but the methods described in Patent Documents 1 and 2 are not limited to the type of substrate used, and are sandwiched between the substrates to form an intermediate layer. The degree of freedom of the type of the curable resin composition is large, resources for forming the intermediate layer can be effectively used, the productivity is excellent, and the environmental load is small.
In this method, a seal portion for containing the curable resin composition is formed in the peripheral portion on one substrate, and then the curable resin composition is supplied to a region surrounded by the seal portion on the substrate. Next, the curable resin composition is sandwiched between the pair of substrates by sealing the other substrate on the curable resin composition supplied on one substrate in a reduced pressure atmosphere, and sealed. (Hereinafter, in this specification, the procedure of superimposing the other substrate on the curable resin composition supplied on one substrate in a reduced pressure atmosphere is referred to as “reduced pressure lamination”. May say).
Next, the obtained laminated precursor is put under a pressure atmosphere (for example, under atmospheric pressure) higher than the above-described reduced pressure atmosphere (hereinafter, in this specification, this procedure is referred to as “releasing the reduced pressure atmosphere”) Is). The curable resin in the sealed space of the laminated precursor, which is pressed in the direction in which the pair of transparent substrates are brought into close contact with each other by the increase in the atmospheric pressure due to the release of the reduced-pressure atmosphere, and is sealed with the pair of substrates and the seal portion. The volume of voids remaining in the composition layer is reduced according to the pressure difference of the atmosphere, whereby the curable resin composition flows through the sealed space, and the entire sealed space is formed by the curable resin composition. The voids that are uniformly filled and remain in the curable resin composition layer in the sealed space disappear, thereby forming a curable resin composition layer having no voids in the sealed space. Then, a laminated body is obtained by hardening a curable resin composition.

International Publication WO2008 / 081838 International Publication WO2009 / 016943 JP 2009-205065 A Japanese Patent Application Laid-Open No. 11-87743

As described above, in the method for manufacturing a laminate described in Patent Documents 1 and 2, after obtaining a laminate precursor by reduced pressure lamination, the reduced pressure atmosphere is released, and the laminate is sealed with a pair of substrates and a seal portion. The curable resin composition layer without voids is formed in the sealed space of the laminated precursor, but the voids remaining in the curable resin composition layer in the sealed space after releasing the reduced-pressure atmosphere The time required for disappearance varies depending on the size of the void. The larger the void remaining in the curable resin composition layer, the longer the time required for the void to disappear.
Here, when the viscosity of the curable resin composition to be used is high (for example, when the viscosity of the curable resin composition is 0.2 Pa · s or more), or the thickness of the curable resin composition layer in the sealed space. Is large (for example, when the thickness of the curable resin composition layer is 30 μm or more), a large gap tends to remain in the sealed space, and it tends to take a long time until the gap disappears. It is desirable that voids remaining in the curable resin composition layer in the sealed space be as small as possible when the atmosphere is released.

  Specifically, when the viscosity of the curable resin composition to be used is high (for example, when the viscosity of the curable resin composition is 0.2 Pa · s or more), or the curable resin composition layer in the sealed space. When the thickness is large (for example, when the thickness of the curable resin composition layer is 30 μm or more), the voids remaining in the curable resin composition layer in the sealed space when the reduced-pressure atmosphere is released. If the diameter is less than 0.5 mm, the time required until the voids remaining in the curable resin composition layer disappear is preferably within about 10 minutes.

  In order to solve the above-described problems of the prior art, the present invention can reduce the diameter of the voids remaining in the curable resin composition layer in the sealed space when the decompressed atmosphere is released. Thus, an object of the present invention is to provide a novel method capable of shortening the time required until voids remaining in the curable resin composition layer disappear.

In order to achieve the above object, the present invention prepares two substrates, forms a seal part for enclosing the curable resin composition in the peripheral part on one substrate, A curable resin composition is supplied to the enclosed region, and the other substrate is overlaid on the supplied curable resin composition in a reduced-pressure atmosphere, and the curable resin composition is sandwiched between a pair of substrates. After sealing to obtain a laminated precursor, the laminated precursor is placed in a second pressure atmosphere whose atmospheric pressure is 50 kPa or more higher than the reduced pressure atmosphere, and a curable resin is obtained in the second pressure atmosphere. A method for producing a laminate for curing a composition,
The procedure for superimposing the other substrate on the supplied curable resin composition is that the atmospheric pressure P is 0.1 to 1000 Pa and the pressure gradient of the atmospheric pressure (ΔP / ΔT (Pa / sec )) Is performed in a reduced pressure atmosphere that satisfies −1 (Pa / sec) ≦ ΔP / ΔT ≦ 0 (Pa / sec),
A pressure change amount (ΔP (Pa) of the atmospheric pressure from when the procedure of superimposing the other substrate on the supplied curable resin composition is performed until immediately before the lamination precursor is placed in the second pressure atmosphere. )) At −1 (Pa) ≦ ΔP ≦ 2 (Pa), and
Provided is a method for manufacturing a laminate, wherein the laminate precursor is placed in a second pressure atmosphere in a state where the laminate precursor is pressurized in a direction in which the distance between the pair of substrates is reduced. .

  In the manufacturing method of the laminated body of this invention, it is preferable that the viscosity of the said curable resin composition is 0.2-50 Pa.s.

  In the method for producing a laminate of the present invention, the thickness of the curable resin composition layer in the sealed space of the laminate precursor, which is sealed by the pair of substrates and the seal portion, is 30 to 3000 μm. preferable.

In the method for producing a laminate according to the present invention, the viscosity of the curable resin composition is 1 to 14 Pa · s, and the sealed precursor space is sealed with the pair of substrates and the seal portion. When the thickness of the curable resin composition layer is 100 to 2000 μm, when the layered precursor is placed in a second pressure atmosphere, the layered precursor is pressurized at a pressure of 30 to 37 g / cm ^2. It is preferable.

  In the method for producing a laminate of the present invention, a time from when the procedure for superimposing the other substrate on the supplied curable resin composition is performed until the laminate precursor is placed in a second pressure atmosphere. It is preferable that T (sec) is T ≦ 5 sec.

  When the curable resin composition contains a component having a vapor pressure higher than the atmospheric pressure of the reduced-pressure atmosphere, it is preferable to apply the laminate manufacturing method of the present invention.

  In the manufacturing method of the laminated body of this invention, it is preferable that the said seal part is formed using the 2nd curable resin composition whose viscosity is 200-3000 Pa * s.

  In the manufacturing method of the laminated body of this invention, it is preferable that at least one is a transparent substrate.

  In the method for producing a laminate of the present invention, the diameter of the voids remaining in the curable resin composition layer in the sealed space of the laminate precursor at the time when the reduced pressure atmosphere is released can be reduced, thereby The time required until the voids remaining in the curable resin composition layer disappear can be shortened. Specifically, when the viscosity of the curable resin composition to be used is high (for example, when the viscosity of the curable resin composition is 0.2 Pa · s or more), or the curable resin composition layer in the sealed space. When the thickness is large (for example, when the thickness of the curable resin composition layer is 30 μm or more), the voids remaining in the curable resin composition layer in the sealed space when the reduced-pressure atmosphere is released The diameter can be less than 0.5 mm, whereby the time required until the voids remaining in the curable resin composition layer disappear can be made within about 10 minutes.

FIG. 1 is a plan view of a substrate, showing a state where a seal portion is formed in the peripheral portion on the substrate.

  Hereafter, the manufacturing method of the laminated body of this invention is demonstrated with reference to drawings.

  In the manufacturing method of the laminated body of this invention, the seal | sticker part for enclosing a curable resin composition is formed in the peripheral part on one board | substrate among a pair of board | substrates. FIG. 1 is a plan view of the substrate, and shows a state in which a seal portion 20 is formed in the peripheral portion on the substrate 10.

[substrate]
In the manufacturing method of the laminated body by this invention, since it is preferable to use a photocurable resin composition as a curable resin composition so that it may mention later, at least 1 is a transparent substrate among a pair of board | substrates. It is preferable. In this case, only one of the pair of substrates may be a transparent substrate and the other may be an opaque substrate, or both substrates may be transparent substrates. Here, when one is a transparent substrate and the other is an opaque substrate, a seal portion may be formed around the transparent substrate, or a seal portion may be formed around the opaque substrate.
The transparent substrate is not particularly limited as long as it is transparent, that is, a substrate having optical transparency. Specific examples of the transparent substrate include a glass substrate and a transparent resin substrate. Among these, a glass substrate is preferable because it has transparency, light resistance, low birefringence, high plane accuracy, surface scratch resistance, and high mechanical strength.
Examples of the material for the glass substrate include soda lime glass, highly transmissive glass (white plate) having lower iron content and less bluishness, and borosilicate glass.
Examples of the material for the transparent resin substrate include highly transparent resin materials (such as polycarbonate and polymethyl methacrylate).

In addition, as long as the transparent substrate has at least light transmittance, the substrate surface is subjected to fine uneven processing for the purpose of scattering or refracting light, or light shielding printing is performed on the substrate surface. It may be given.
A transparent substrate on which a plurality of transparent substrates are bonded, or a transparent substrate on which an optical film or the like is bonded can also be used as an integrated transparent substrate.
A structure including a transparent substrate as a part of the constituent elements can also be used as the transparent substrate. Specific examples of the structure including such a transparent substrate as a component include a liquid crystal display (LCD), an EL (electroluminescence) display device such as an organic EL or an inorganic EL, a plasma display device, and an electronic ink type image. Examples include a flat panel display (FPD) such as a display device, a thin-layer solar cell device, and a touch panel.

  When one of the pair of substrates is an opaque substrate, specific examples of the opaque substrate include a substrate made of a metal material such as stainless steel, a substrate made of a ceramic material, and a filler that absorbs visible light in the substrate. Examples thereof include a resin substrate that is shielded from light by being dispersed.

  When both the pair of substrates are transparent substrates, the pair of transparent substrates may be formed of the same material or different materials. That is, both of the pair of transparent substrates may be a glass substrate or a transparent resin substrate, and one of the pair of transparent substrates may be a glass substrate and the other may be a transparent resin substrate.

The thickness of the substrate is not particularly limited, but in the case of a transparent substrate, from the viewpoint of mechanical strength and transparency, it is usually 1 to 6 mm in the case of a glass substrate, and usually 0.1 to 3 mm in the case of a transparent resin substrate. It is.
On the other hand, in the case of an opaque board | substrate, it is 0.8-4 mm normally from the point of mechanical strength and a thin weight reduction.
Note that the thickness of the pair of substrates may be the same or different.

The surface of the substrate, more specifically, the surface on the side where the seal portion is formed in the peripheral portion may be subjected to surface treatment in order to improve the interfacial adhesive force with the seal portion. Here, the surface treatment may be performed only on the peripheral portion of the substrate, or may be performed on the entire surface of the substrate.
Examples of the surface treatment method include a method of treating the surface of the substrate with a silane coupling agent.

[Seal part]
The seal portion is provided for the purpose of containing the curable resin composition that is supplied to the region surrounded by the seal portion and then sandwiched and sealed between the pair of substrates under a reduced pressure atmosphere. In the production process of the laminate, the curable resin composition supplied to the region surrounded by the seal portion has an interface adhesive force that does not leak out and has a shape in the production process of the laminate of the present invention. It must be hard enough to maintain.
A seal portion satisfying such a requirement can be formed by providing a seal member having an adhesive or pressure-sensitive adhesive on the surface on the periphery of one substrate.
Specific examples of such a seal member include the following.
-A tape-like or rod-like long body (double-sided adhesive tape, etc.) with a pressure-sensitive adhesive layer or adhesive layer provided on the surface in advance.
-An adhesive layer or a pressure-sensitive adhesive layer is formed on the peripheral edge of the surface of one of the substrates, and a long body is pasted thereon.
-A dam-like seal precursor is formed by printing or dispensing on the peripheral edge of the surface of one substrate using the curable resin composition, and after the curable resin composition is cured, an adhesive layer is formed on the surface. Or what formed the adhesive layer.

In addition, the seal portion that satisfies the above-described requirements is a dispenser or die coater so that a high-viscosity curable resin composition as the second curable resin composition has a predetermined thickness on the periphery of one substrate. It can also form by apply | coating using.
Here, the second curable resin composition may be cured at the same time as the cured curable resin composition sandwiched between the pair of substrates and cured in the procedure to be described later. The resin composition may be cured before curing.
The second curable resin composition has a viscosity of 200 to 3000 Pa · s, and has a strength to contain the curable resin composition when the curable resin composition is supplied to a region surrounded by the seal portion. And when the release of the reduced pressure lamination and the reduced pressure atmosphere is performed, the seal is matched with the thickness of the curable resin composition layer in the sealed space of the laminated precursor sealed with the pair of substrates and the seal portion. It is preferable that the portion can be deformed, and that the seal portion has strength to withstand atmospheric pressure when the reduced pressure lamination and release of the reduced pressure atmosphere are performed, and more preferably 500 to 2000 Pa · s.
Here, in order to maintain the distance between the pair of substrates, spacer particles having a predetermined particle diameter may be blended in the second curable resin composition.
In addition, as a 2nd curable resin composition, it is a photocurable resin composition mentioned later, Comprising: It is preferable to use what satisfy | fills said viscosity.

The seal portion is a layer formed by the curable resin composition supplied to the region surrounded by the seal portion so that the curable resin composition supplied to the region surrounded by the seal portion does not leak out. (Hereinafter, in this specification, it may be simply referred to as a “curable resin composition layer”). For example, the thickness is preferably 1.1 to 2 times the predetermined thickness of the curable resin composition layer.
Moreover, although the width | variety of a seal part changes also with the thickness of a curable resin composition layer, 0.5-5 mm is preferable.

Next, the curable resin composition is supplied to a region surrounded by the seal portion on the substrate.
The supply amount of the curable resin composition is such that when the curable resin composition is sandwiched between a pair of substrates and sealed in a procedure described later, the laminated precursor is sealed with the pair of substrates and the sealing portion. Is set in advance to an amount sufficient to be filled with the curable resin composition. At this time, the supply amount of the curable resin composition can be determined in consideration of the volume reduction due to the curing shrinkage of the curable resin composition.
In the method for producing a laminate of the present invention, the thickness of the curable resin composition layer present in the sealed space of the laminate precursor, which is sealed by the pair of substrates and the seal portion, in the laminate precursor after decompression lamination. Is preferably 30 to 3000 μm. The reason is that the curable resin composition layer requires not only a function as an adhesive between a pair of substrates, but also a thickness for imparting a function of imparting mechanical strength to the layer. This is because it is not preferable to unnecessarily increase the thickness because a thin and light weight is required as represented by an opening member and a display member.
When the curable resin composition is sandwiched and sealed between a pair of substrates in the procedure described below, the curable resin composition layer that is sealed by the pair of substrates and the seal portion and exists in the sealed space of the laminated precursor The thickness of is more preferably 100 to 2000 μm, further preferably 100 to 1600 μm, and further preferably 100 to 800 μm.

  As a method for supplying the curable resin composition, there are a method in which the substrate on which the seal portion is formed in the above-described procedure is placed flat, and a method in which the substrate is dispersed and dropped by a supply means such as a dispenser or a method in which the substrate is applied linearly. Can be mentioned.

In the production method of the present invention, a conventional method (for example, a method described in JP-A-57-165411, JP-A-2001-339088) in which a curable resin is injected into a gap between previously formed laminates. In comparison, a curable resin composition having a relatively high viscosity can be used. Thereby, reduction of curing shrinkage when curing the curable resin composition and improvement of the mechanical strength of the cured resin layer can be achieved.
It is preferable that the viscosity of the curable resin composition to be used is 0.2 to 50 Pa · s because it is easy to handle industrially in a process of producing, transferring and applying a large amount of the curable resin composition.
The viscosity of the curable resin composition referred to here is the viscosity in the temperature range when the laminate production method of the present invention is carried out, and in particular, the curable resin composition is applied to the region surrounded by the seal portion. This is the viscosity in the temperature range after the supply until the reduced pressure lamination is carried out according to the procedure described later. For example, when these procedures are performed at room temperature, it is the viscosity of the curable resin composition at room temperature. Therefore, although it changes with the temperature at the time of implementing these procedures, in any case, it exists in the temperature range of 5-80 degreeC. About this point, the viscosity of the 2nd curable resin composition used for formation of the sealing part mentioned above is also the same.
The viscosity of the curable resin composition to be used is more preferably 1 to 20 Pa · s, and further preferably 1 to 14 Pa · s.

As the curable resin composition satisfying the above viscosity, a curable resin composition containing a high molecular weight curable compound (oligomer or the like) as described below can be used.
Since the high molecular weight curable compound can reduce the number of chemical bonds in the curable resin composition, the curing shrinkage when curing the curable resin composition is reduced, and the mechanical properties of the resin layer after curing are reduced. Strength is improved. On the other hand, many high molecular weight curable compounds are highly viscous. Therefore, from the point of suppressing the remaining voids while ensuring the mechanical strength of the resin layer after curing, it is possible to adjust the viscosity by dissolving a curable monomer having a lower molecular weight in a high molecular weight curable compound. preferable. However, by using a curable monomer having a small molecular weight, the viscosity of the curable resin composition is lowered, but the curing shrinkage when the curable resin composition is cured is large, and the mechanical strength tends to decrease.

  The curable resin composition to be used is preferably a photocurable resin composition. The photocurable resin composition is cured in a short time with less heat energy than the thermosetting resin composition. Therefore, the environmental load at the time of manufacturing a laminated body becomes small by using a photocurable resin composition in this invention. Moreover, since the photocurable resin composition can be substantially cured in several minutes to several tens of minutes, the production efficiency of the laminate is high.

A photocurable resin composition is a material that is cured by the action of light to form a resin layer. As a photocurable resin composition, the following are mentioned, for example, It can use in the range which the hardness of the resin layer after hardening does not become high too much.
A composition comprising a compound having an addition polymerizable unsaturated group and a photopolymerization initiator.
A polyene compound having 1 to 6 unsaturated groups (triallyl isocyanurate, etc.) and a polythiol compound having 1 to 6 thiol groups (triethylene glycol dimercaptan) A composition containing a photopolymerization initiator, which is contained in a proportion in which the number of moles is substantially equal.
A composition comprising an epoxy compound having two or more epoxy groups and a photocation generator.

  The photocurable resin composition is described as a group selected from an acryloyloxy group and a methacryloyloxy group (hereinafter referred to as a (meth) acryloyloxy group) from the viewpoint that the curing rate is high and the transparency of the cured resin layer is high. It is more preferable to contain at least one compound having a photopolymerization initiator) and a photopolymerization initiator.

As the compound having a (meth) acryloyloxy group (hereinafter also referred to as a (meth) acrylate compound), a compound having 1 to 6 (meth) acryloyloxy groups per molecule is preferable, and the cured resin layer is A compound having 1 to 3 (meth) acryloyloxy groups per molecule is particularly preferable because it is not too hard.
As the (meth) acrylate-based compound, an aliphatic or alicyclic compound that contains as few aromatic rings as possible is preferable from the viewpoint of light resistance of the cured resin layer.
Moreover, as a (meth) acrylate type compound, the compound which has a hydroxyl group is more preferable from the point of the improvement of the interface adhesive force with a board | substrate. The content of the (meth) acrylate compound having a hydroxyl group is preferably 25% by mass or more, more preferably 40% by mass or more, of all (meth) acrylate compounds. On the other hand, the compound having a hydroxyl group tends to have a high modulus of elasticity of the resin layer after curing. Particularly when (meth) acrylate having a hydroxyl group is used, the resin layer after curing becomes hard depending on the use of the laminate. There is a risk of passing. For example, when used for a front panel plate of a flat panel display (FPD), since the cured resin layer preferably has a low elastic modulus, the content of (meth) acrylate having a hydroxyl group is 40% by mass or less. Preferably, 30 mass% or less is more preferable.
In addition, in the lamination of substrates made of different materials, such as lamination of a glass substrate and a resin substrate such as polycarbonate, the resin layer has a good adhesion to any substrate on the substrate surface with different surface energy. A resin layer exhibiting a low-elastic modulus adhesive state can be used so that it can be expressed.
On the other hand, when laminating a thin glass substrate and a thick glass substrate, it is possible to increase the mechanical strength of the laminate by providing a thin resin layer having a high elastic modulus and 0.1 mm or less. The content of the (meth) acrylate having a hydroxyl group can be 60% by mass or more.

The (meth) acrylate compound may be a relatively low molecular compound (hereinafter referred to as an acrylate monomer), and a relatively high molecular weight compound having a repeating unit (hereinafter referred to as a (meth) acrylate oligomer). May be).
Examples of the (meth) acrylate compound include one or more (meth) acrylate monomers, one or more (meth) acrylate oligomers, one or more (meth) acrylate monomers (meth) ) One or more acrylate oligomers are mentioned, and one or more acrylate oligomers, or one or more acrylate oligomers and one or more (meth) acrylate monomers Is preferred. For the purpose of enhancing the adhesion to the substrate, a urethane oligomer having an average of 1.8 to 4 curable functional groups each consisting of one or both of an acryloyloxy group and a methacryloyloxy group, and the number of hydroxyl groups is 1. A curable resin composition containing one or two hydroxyalkyl methacrylates having a hydroxyalkyl group having 3 to 8 carbon atoms is particularly preferable.

  In addition, when the laminate is used for a front panel plate of a flat panel display (FPD), the cured resin is used so that shrinkage of the resin during the curing process does not adversely affect the display performance of the flat panel display (FPD). It is preferred that the layer has a lower modulus. Therefore, an oligomer having an average of 1.8 to 4 curable functional groups consisting of (meth) acryloyloxy groups, and a hydroxyalkyl group having 3 to 8 carbon atoms having 1 or 2 hydroxyl groups. A curable resin composition containing a hydroxyalkyl methacrylate having at least one of a (meth) acrylate monomer having no hydroxyl group is preferred. Furthermore, it is more preferable that the total content of the (meth) acrylate monomer having no hydroxyl group is larger in mass ratio than the content of the (meth) acrylate monomer having a hydroxyl group. Moreover, the hydroxyalkyl (meth) acrylate hydroxyl group which has a C12-C22 hydroxyalkyl group with one hydroxyl group can be used instead of the (meth) acrylate monomer which does not have a hydroxyl group.

  As the (meth) acrylate monomer, a compound having a vapor pressure that is low enough to sufficiently suppress volatilization in a reduced pressure atmosphere, considering that the photocurable resin composition is placed in a reduced pressure atmosphere in a reduced pressure apparatus. Specifically, a compound having a vapor pressure lower than the atmospheric pressure of the reduced-pressure atmosphere when the reduced-pressure lamination is performed according to the procedure described later is preferable. When the curable resin composition contains a (meth) acrylate monomer having no hydroxyl group, an alkyl (meth) acrylate having 8 to 22 carbon atoms, a polyether such as polyethylene glycol or polypropylene glycol having a relatively low molecular weight Diol mono (meth) acrylate or di (meth) acrylate can be used, and alkyl methacrylate having 8 to 22 carbon atoms is preferable.

The (meth) acrylate oligomer is a (meth) acrylate polymer having a molecular structure having a chain (polyurethane chain, polyester chain, polyether chain, polycarbonate chain, etc.) having two or more repeating units and a (meth) acryloyloxy group. Oligomers are preferred.
Examples of the (meth) acrylate oligomer include a urethane bond (usually further including a polyester chain and a polyether chain) called a urethane acrylate oligomer and two or more (meth) acryloyloxy groups (meth). Examples include acrylate oligomers. Urethane acrylate is more preferable because the mechanical design of the cured resin layer and the adhesion to the substrate can be widely adjusted by the molecular design of the urethane chain.

The number average molecular weight of the (meth) acrylate oligomer is preferably from 1,000 to 100,000, more preferably from 10,000 to 70,000. If the number average molecular weight is less than 1000, the crosslink density of the cured resin layer becomes high, and the flexibility of the resin layer may be impaired. If the number average molecular weight is greater than 100,000, the viscosity of the uncured curable resin composition may be too high. When the viscosity of the (meth) acrylate oligomer is too high, it is preferable to reduce the viscosity of the curable resin composition as a whole in combination with the (meth) acrylate monomer.
On the other hand, when used as the second curable resin composition used for forming the seal portion, it has a curable group and has a number average because the viscosity is easily adjusted to the above-described range of 200 to 3000 Pa · s. One or more types of curable oligomers having a molecular weight of 30,000 to 100,000, and one or more types of (meth) acrylate monomers having a curable group, and the proportion of monomers is the sum of oligomers and monomers ( 100 mass%) is preferably 15 to 50 mass%.
The (meth) acrylate oligomer is more preferably an acrylate oligomer that can increase the reactivity in curing.

Examples of the photopolymerization initiator include acetophenone series, ketal series, benzoin or benzoin ether series, phosphine oxide series, benzophenone series, thioxanthone series, quinone series, and the like. Photoinitiators are preferred. When curing with visible light having a short wavelength, a phosphine oxide photopolymerization initiator is more preferable from the absorption wavelength region of the photopolymerization initiator. By using two or more kinds of photopolymerization initiators having different absorption wavelength ranges, the curing time can be further accelerated, or the surface curability can be enhanced in the second curable resin composition used for forming the seal portion. More preferred.
Examples of the photo cation generator include onium salt compounds.

The curable resin composition may contain a polymerization inhibitor, a photocuring accelerator, a chain transfer agent, a light stabilizer (such as an ultraviolet absorber or a radical scavenger), an antioxidant, a flame retardant, and an adhesive as necessary. Various additives such as an improver (such as a silane coupling agent), a pigment, and a dye may be included, and a polymerization inhibitor and a light stabilizer are preferably included. In particular, by including a polymerization inhibitor in a smaller amount than the polymerization initiator, the stability of the curable resin composition can be improved, and the molecular weight of the cured resin layer can also be adjusted.
However, depending on the use of the laminate, it is not preferable to include an additive that may hinder the transmission of light in the cured resin layer. For example, when the use of the laminate is a front panel plate of a flat panel display (FPD) or a thin-layer solar cell device, the former is the light emitted from the flat panel display (FPD) that forms a display image. About reflected light and the latter, since sunlight permeate | transmits the resin layer after hardening, it is not preferable to contain the additive which may prevent transmission of those light rays. For example, the ultraviolet absorber absorbs the ultraviolet component of sunlight transmitted through the resin layer to reduce the amount of light incident on the thin-layer solar cell device, or adversely affects the color tone of the display image of the flat panel display (FPD). There is a risk of giving. However, on the other hand, the resin layer through which sunlight passes is required to have light resistance, particularly durability against light having a short wavelength such as ultraviolet rays. Therefore, when an ultraviolet absorber or the like is included, it is preferable to appropriately adjust the absorption characteristics, blending amount, and the like.
Moreover, in order to improve adhesiveness with a board | substrate or to adjust the elasticity modulus of the resin layer after hardening, it is preferable to contain a chain transfer agent, and the chain transfer agent which has a thiol group in a molecule | numerator is especially preferable.

Examples of the polymerization inhibitor include polymerization inhibitors such as hydroquinone (2,5-di-t-butylhydroquinone, etc.), catechol (pt-butylcatechol, etc.), anthraquinone, phenothiazine, hydroxytoluene and the like. Can be mentioned.
Examples of the light stabilizer include ultraviolet absorbers (benzotriazole series, benzophenone series, salicylate series, etc.), radical scavengers (hindered amine series), and the like.
Examples of the antioxidant include phosphorus-based and sulfur-based compounds.
As the photopolymerization initiator and various additives, since the curable resin composition is placed in a reduced-pressure atmosphere, the compound has a relatively large molecular weight and has a vapor pressure low enough to sufficiently suppress volatilization in the reduced-pressure atmosphere. C4 or more compounds having polar sites such as hydroxyl groups such as (meth) acrylic acid and the like, specifically, vapor sufficiently lower than the atmospheric pressure of the reduced pressure atmosphere when the reduced pressure lamination is performed according to the procedure described later A compound having a pressure and a relatively large molecular weight, a compound having a polar site such as a hydroxyl group such as (meth) acrylic acid, and the like are preferable.

As described above, the component contained in the curable resin composition is a material having a vapor pressure lower than the atmospheric pressure of the reduced-pressure atmosphere when performing reduced-pressure lamination in order to suppress volatilization in the reduced-pressure atmosphere. Is selected. However, the curable resin composition to be produced has a component that may volatilize in a reduced-pressure atmosphere, specifically, a component having a vapor pressure higher than the atmospheric pressure of the reduced-pressure atmosphere when performing reduced-pressure lamination ( Hereinafter, in this specification, “volatile components” may be included as inevitable impurities. Volatile components contained as such inevitable impurities vary depending on the type of components contained in the curable resin composition to be used, in particular, the type of curable compound contained in the curable resin composition. When the product contains a (meth) acrylate compound, examples thereof include (meth) acrylic acid which is a raw material compound, diacrylic anhydride, a hydroxyl group-containing compound having a relatively low molecular weight such as ethylene glycol and butanediol. . Moreover, when curable resin composition contains a urethane acrylate oligomer, 2-hydroxyethyl acrylate etc. which are examples of the raw material compound are illustrated. Further, various additives such as a polymerization inhibitor and an antioxidant that may be contained in the raw material compound may become a volatile component when the molecular weight is small.
Moreover, in the procedure until it carries out pressure reduction lamination | stacking, the water | moisture content in air | atmosphere may be contained in curable resin composition. What contained such moisture in the atmosphere in the curable resin composition is also an example of a volatile component contained as an inevitable impurity.
Although the content of volatile components contained as inevitable impurities is as small as 0.01 to 1 wt%, the volatilization of the volatile components under a reduced pressure atmosphere is within the sealed space of the laminated precursor when the reduced pressure atmosphere is released. The inventors of the present application have found that it affects the diameter of the voids remaining in the curable resin composition layer.

Next, decompression lamination is performed. That is, in a reduced-pressure atmosphere, the other substrate is overlaid on the curable resin composition supplied to the region surrounded by the seal portion by the above procedure. In order to achieve this, among the surfaces of one of the substrates, the surface on the side to which the curable resin composition is supplied in the above procedure is directed to the other substrate, and the pair of substrates and the other substrate What is necessary is just to overlap | superpose a board | substrate. By overlapping, the curable resin composition is sandwiched and sealed between a pair of substrates, more specifically, in the space surrounded by the surface of one substrate, the lower surface of the other substrate, and the seal portion. A laminate precursor in which the curable resin composition is sealed is obtained.
At the time of superposition, the curable resin composition is spread by the weight of the other substrate, the pressure from the moving support mechanism, and the like, and the curable resin composition is filled in the above-described space.

In the manufacturing method of the laminated body of this invention, the atmospheric pressure (P) of the reduced pressure atmosphere at the time of implementing a reduced pressure lamination shall be 0.1-1000 Pa. When the atmospheric pressure is higher than 1000 Pa, when the atmospheric pressure increases due to the release of the reduced pressure atmosphere, the reduction rate of the voids remaining in the curable resin composition layer in the sealed space of the lamination precursor decreases, There is a problem that it takes a long time to eliminate the voids. On the other hand, if the atmospheric pressure (P) is lower than 0.1 Pa, there is a risk of adversely affecting each component (curable compound, photopolymerization initiator, polymerization inhibitor, light stabilizer, etc.) contained in the curable resin composition. There is. For example, each component described above may be vaporized, and it may take time to provide a reduced pressure atmosphere. In addition, since it is necessary to make atmospheric pressure (P) 1000 Pa or less, the volatile component in the reduced pressure atmosphere contained as an inevitable impurity in the curable resin composition volatilizes in the reduced pressure atmosphere in which the reduced pressure lamination is performed. Cannot be prevented.
The atmospheric pressure (P) of the reduced pressure atmosphere is more preferably 1 to 100 Pa. 3-30 Pa is more preferable.

Furthermore, when carrying out the decompression lamination, the pressure gradient (ΔP / ΔT (Pa / sec)) of the atmospheric pressure of the decompression atmosphere needs to satisfy the following formula.
−1 (Pa / sec) ≦ ΔP / ΔT ≦ 0 (Pa / sec)
The pressure gradient (ΔP / ΔT) mentioned here refers to a pressure gradient between the atmospheric pressure at the time when the decompression stacking is performed (that is, the time when the superposition is performed) and the atmospheric pressure just before that. For example, when the atmospheric pressure of the reduced-pressure atmosphere has reached equilibrium at the time of carrying out the reduced-pressure lamination, the pressure gradient (ΔP / ΔT) = 0 (Pa / sec). When the atmospheric pressure at the time of carrying out the decompression lamination is lower than the atmospheric pressure immediately before, the pressure gradient (ΔP / ΔT) <0 (Pa / sec), and the atmospheric pressure at the time of carrying out the decompression lamination is When it is higher than the atmospheric pressure immediately before, the pressure gradient (ΔP / ΔT)> 0 (Pa / sec).
When the pressure reduction (ΔP / ΔT) satisfies the above formula, the reduced pressure lamination is performed by diffusing the volatile components volatilized from the curable resin composition in the reduced pressure atmosphere and removing them. When the layered precursor is formed by the above, the volatile components taken into the sealed space of the formed layered precursor are reduced. As a result, the volatile component is taken into the sealed space, thereby preventing a large gap from being formed in the curable resin composition layer in the sealed space.

  When the pressure gradient (ΔP / ΔT)> 0 (Pa / sec), that is, when the atmospheric pressure at the time of carrying out the decompression lamination is higher than the atmospheric pressure immediately before, the curable resin composition volatilized. Volatile components are present in the vicinity of the curable resin composition without being diffused and removed in a reduced-pressure atmosphere, and when the lamination precursor is formed by reduced-pressure lamination, in the sealed space of the formed lamination precursor The volatile component is taken up. As a result, large voids are formed in the curable resin composition layer in the sealed space.

  When the pressure gradient (ΔP / ΔT) <− 1 (Pa / sec), volatilization of the volatile component from the curable resin composition becomes active, so that it was formed when the lamination precursor was formed by reduced pressure lamination. The volatile component taken into the sealed space of the lamination precursor increases in accordance with the magnitude of the absolute value of the negative direction of the pressure gradient, and more volatile components are taken into the sealed space. As a result, large voids are formed in the curable resin composition in the sealed space.

When carrying out the decompression lamination, it is preferable that the pressure gradient (ΔP / ΔT) of the atmosphere pressure of the decompression atmosphere satisfies the following formula.
−0.5 (Pa / sec) ≦ ΔP / ΔT ≦ 0 (Pa / sec)

  In the method for producing a laminate of the present invention, the reduced pressure lamination can be performed by the following procedure. Hereinafter, in this specification, of the pair of substrates, the substrate on the side where the seal portion and the layer of the curable resin composition are formed on the surface is referred to as one substrate, and the side on which the surface is not formed on the surface. The substrate is referred to as the other substrate.

One substrate is put in a decompression device, and the substrate is placed flat on a fixed support plate in the decompression device so that the surface of the curable resin composition is on the top.
A movement support mechanism that can move in the vertical direction is provided in the upper part of the decompression device, and the other substrate is attached to the movement support mechanism. Here, when the thin film solar cell device is formed on the surface of the other substrate, the surface on the side where the thin film solar cell device is formed is turned downward. Moreover, when the use of the laminate is a flat panel display (FPD), the surface on the image display side is directed downward. When the antireflection layer is provided on the surface of the other substrate, the surface on the side where the antireflection layer is not formed is directed downward.
The other substrate is placed above one substrate and in a position not in contact with the curable resin composition. That is, the curable resin composition on one substrate and the other substrate are opposed to each other without being brought into contact with each other.

A movable support mechanism that can move in the vertical direction may be provided in the lower part of the decompression device, and one substrate may be placed on the movable support mechanism. In this case, the other substrate is attached to a fixed support plate provided at the upper part in the decompression device, and the one substrate and the other substrate are opposed to each other.
Moreover, you may support both one board | substrate and the other board | substrate with the movement support mechanism provided in the upper and lower sides in the decompression device.

After arranging one substrate and the other substrate at a predetermined position, the inside of the decompression device is decompressed to obtain the above-described predetermined decompressed atmosphere. If possible, one substrate and the other substrate may be positioned in a predetermined position in the decompression apparatus during the decompression operation or after a predetermined decompression atmosphere.
Thereafter, the other substrate supported by the moving support mechanism is moved downward in a state where the inside of the decompression device is maintained in the above-described predetermined decompression atmosphere, and the other substrate is placed on the curable resin composition on one substrate. Superimpose the substrates.

Next, the decompressed atmosphere is released. That is, the laminate precursor obtained by the reduced pressure lamination is placed in a second pressure atmosphere (for example, under atmospheric pressure) having an atmospheric pressure higher than that of the reduced pressure atmosphere in which the reduced pressure lamination is performed.
The curable resin composition in the sealed space of the laminated precursor, which is pressed in the direction in which the pair of substrates are brought into close contact with each other by the increase in the atmospheric pressure due to the release of the reduced-pressure atmosphere, and is sealed with the pair of substrates and the seal portion. When the volume of the voids remaining in the layer is reduced according to the pressure difference of the atmosphere, the entire sealed space is uniformly filled with the curable resin composition.
Here, in order to exert the above effect, the second pressure atmosphere is required to have an atmospheric pressure of 50 kPa or more higher than the reduced pressure atmosphere at the time of performing the reduced pressure lamination, and usually the atmospheric pressure is higher than the reduced pressure atmosphere. 80k-120kPa high. The second pressure atmosphere may be an atmospheric pressure atmosphere or an atmospheric pressure higher than that. An atmospheric pressure atmosphere is most preferable because operations such as curing of the curable resin composition can be performed without requiring special equipment.

In the method for manufacturing a laminate according to the present invention, the pressure change amount (ΔP (Pa)) of the atmospheric pressure from when the reduced pressure lamination is performed to immediately before the release of the reduced pressure atmosphere is set to −1 (Pa) ≦ ΔP ≦. 2 (Pa). Here, in the case of ΔP <0 (Pa), the atmospheric pressure is reduced immediately after the decompression lamination is performed and immediately before the decompression atmosphere is released. On the other hand, in the case of ΔP> 0 (Pa), the atmospheric pressure increases immediately after the decompression lamination is performed and immediately before the decompression atmosphere is released.
If the pressure change amount (ΔP) of the atmospheric pressure satisfies the above range, volatilization of volatile components from the curable resin composition existing in the sealed space of the lamination precursor is suppressed. Thereby, it is prevented that a big space | gap is formed in the curable resin composition layer in this sealed space.

  When the pressure change amount (ΔP) is smaller than −1 Pa, volatilization of the volatile component from the curable resin composition existing in the sealed space of the lamination precursor becomes active, whereby the curing in the sealed space is achieved. Large voids are formed in the conductive resin composition layer.

  When the pressure change amount (ΔP) is larger than 2 Pa, more volatile components are contained in the voids existing in the curable resin composition layer in the sealed space in the laminated precursor before the release of the reduced-pressure atmosphere. It will be. As a result, there is a problem that it takes a long time for the void to disappear after the decompression atmosphere is released.

Moreover, in the manufacturing method of the laminated body of this invention, it is preferable that time T (sec) after implementing a pressure-reduced lamination | stacking until it cancels | releases a pressure-reduced atmosphere shall be T <= 5sec. That is, it is preferable to release the reduced-pressure atmosphere within 5 seconds after the reduced-pressure lamination is performed.
When the time T from the execution of the reduced pressure lamination to the release of the reduced pressure atmosphere is longer than 5 seconds, the volatilization of the volatile component from the curable resin composition present in the sealed space of the lamination precursor causes the There exists a possibility that a big space | gap may be formed in the curable resin composition layer in sealed space.
On the other hand, when the reduced pressure atmosphere is released within 5 seconds after the reduced pressure lamination is performed, the volatilization of the volatile component from the curable resin composition existing in the sealed space of the lamination precursor is small, The possibility that large voids are formed in the curable resin composition layer in the sealed space is reduced.

In the method for producing a laminate of the present invention, the laminate precursor obtained by decompression lamination is pressurized, more specifically, the laminate is reduced in the direction in which the distance between a pair of substrates constituting the laminate precursor is reduced. Release the reduced-pressure atmosphere in a state where the precursor is pressurized.
Since the curable resin composition layer in the sealed space of the lamination precursor is pressurized by pressurization of the lamination precursor, the curable resin composition is formed in the voids remaining in the curable resin composition layer. Intrusion of volatile components from the As a result, the void remaining in the curable resin composition layer becomes smaller when the reduced pressure atmosphere is released.
In order to exert the above-described effect, it is preferable to continue to pressurize the lamination precursor until the decompression atmosphere is released after the decompression lamination.

  The means for pressurizing the lamination precursor is not particularly limited. For example, the lamination precursor can be pressurized by pressing from the moving support mechanism described above.

The applied pressure necessary to obtain the above-mentioned effect varies depending on the viscosity of the curable resin composition to be used and the thickness of the curable resin composition layer in the sealed space of the laminated precursor, but the curable property to be used is When the viscosity of the resin composition is 1 to 14 Pa · s and the thickness of the curable resin composition layer in the sealed space is 100 to 2000 μm, the lamination precursor is applied at a pressure of 30 to 37 g / cm ^2. It is preferable to apply pressure.
When the applied pressure is less than 30 g / cm ² , the seal part does not sufficiently adhere to the substrate surface, and when the reduced pressure atmosphere is released, the outside air enters the sealed space from the seal part. Large voids may be formed in the curable resin composition layer.
Moreover, even if it can adhere, the effect of suppressing the entry of volatile components from the curable resin composition into the voids remaining in the curable resin composition layer in the sealed space is low, and the release of the reduced pressure atmosphere is eliminated. When implemented, the voids remaining in the curable resin composition layer may not be sufficiently small.
On the other hand, when the applied pressure is larger than 37 g / cm ² , the pressure applied to the curable resin composition becomes excessive, and the curable resin composition may protrude outside the seal portion. When the curable resin composition protrudes outside the seal portion, there is a possibility that a large gap is generated in the curable resin composition layer in the sealed space. Moreover, there exists a possibility that the designability of the laminated body manufactured may be impaired when a curable resin composition protrudes outside a seal | sticker part.

There is no particular limitation on the time for holding the laminated precursor in the second pressure atmosphere after releasing the reduced-pressure atmosphere. When the lamination precursor is taken out from the decompression device, moved to the curing device, and the process from the start of curing is performed in an atmospheric pressure atmosphere, the time required for the process is maintained in the second pressure atmosphere. Become. Therefore, when there is no void in the curable resin composition layer in the sealed space already when placed in an atmospheric pressure atmosphere, or when the void in the curable resin composition layer disappears during the process Can immediately cure the curable resin composition. In the case where it takes time for the voids to disappear, the lamination precursor is held in the second pressure atmosphere until the voids disappear.
According to the method for producing a laminate of the present invention, the diameter of voids remaining in the curable resin composition layer in the sealed space at the time when the reduced-pressure atmosphere is released can be reduced. The time required for the voids remaining in the functional resin composition layer to disappear can be shortened. Specifically, when the viscosity of the curable resin composition to be used is high (for example, when the viscosity of the curable resin composition is 0.2 Pa · s or more), or the curable resin composition layer in the sealed space. When the thickness is large (for example, when the thickness of the curable resin composition layer is 30 μm or more), the voids remaining in the curable resin composition layer in the sealed space when the reduced-pressure atmosphere is released The diameter can be less than 0.5 mm, whereby the time required until the voids remaining in the curable resin composition layer disappear can be made within about 10 minutes.

Next, by curing the curable resin composition in the sealed space, a laminate having a pair of substrates and a cured product layer of the curable resin composition existing between the pair of substrates is manufactured.
As a means for curing the curable resin composition, either thermosetting or photocuring is used depending on the type of the thermosetting resin composition. However, as described above, the curable resin composition used is preferably a photocurable resin composition.
In the case of the photocurable resin composition, for example, by irradiating ultraviolet light or short wavelength visible light from a light source (ultraviolet lamp, high pressure mercury lamp, etc.) to cure the curable resin composition in the sealed space, A laminate having a substrate and a layer of a cured product of the curable resin composition existing between the pair of substrates is manufactured.

Light is emitted from the transparent substrate side of the pair of substrates. When both are transparent substrates, irradiation may be performed from both sides.
When the laminate to be manufactured is a flat panel display (FPD), when the flat panel display uses a transmissive display device, light transmission can be obtained by operating the device, but it is not operated. Since there are many things which do not have a light transmittance in a state, the light which hardens a curable resin composition is irradiated from the transparent substrate used as a protective plate. On the other hand, when a transmission-scattering display device that exhibits a transparent state when the flat panel display is not in operation is used, light from the display device side can also be used.

  The light is preferably ultraviolet light or visible light of 450 nm or less. In particular, when an antireflection layer is provided on a transparent substrate and the resin film used for forming the antireflection layer or the antireflection layer does not transmit ultraviolet rays, curing with visible light is required.

The laminate obtained by the production method of the present invention is suitably used for thin-layer solar cell devices, image display devices, and the like. Specific examples of the thin layer solar cell device include a thin film silicon solar cell device, a compound semiconductor solar cell device such as a chalcopyrite system and a CdTe system. On the other hand, specific examples of the image display device include a liquid crystal display device (LCD), a flat panel display (FPD) such as an EL (electroluminescence) display device such as an organic EL or an inorganic EL, a plasma display device, and an electronic ink image display device. Can be mentioned.
In the case of a thin-layer solar cell device, the thin-layer solar cell device may be formed only on one of the pair of substrates constituting the laminate, or the thin-layer solar cell device may be formed on both substrates. Good.

  Hereinafter, based on an Example, this invention is demonstrated more concretely. However, the present invention is not limited to this. Examples 1, 5 and 6 are examples, and other examples are comparative examples.

(Example 1)
(Photo-curable resin composition for forming a seal part)
Bifunctional polypropylene glycol having a molecular end modified with ethylene oxide (number average molecular weight calculated from hydroxyl value: 4000) and hexamethylene diisocyanate were mixed in a molar ratio of 6 to 7, and then isobornyl acrylate (Osaka) After diluting with IBXA) manufactured by Organic Chemical Industry Co., Ltd., 2-hydroxyethyl acrylate is added to the prepolymer obtained by the reaction in the presence of a tin compound catalyst at a molar ratio of about 1: 2, and reacted. Thus, a urethane acrylate oligomer (hereinafter referred to as UC-1) solution diluted with 30% by mass of isobornyl acrylate was obtained. The number of curable groups of UC-1 was 2, and the number average molecular weight was about 55000. The viscosity of the UC-1 solution at 60 ° C. was about 580 Pa · s.
90 parts by mass of the UC-1 solution and 10 parts by mass of 2-hydroxybutyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light ester HOB) were uniformly mixed to obtain a mixture. 100 parts by mass of the mixture, 1 part by mass of 1-hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, Ciba Specialty Chemicals, IRGACURE 184), bis (2,4,6-trimethylbenzoyl)- 0.1 parts by mass of phenylphosphine oxide (photopolymerization initiator, manufactured by Ciba Specialty Chemicals, IRGACURE 819), 0.04 parts by mass of 2,5-di-t-butylhydroquinone (polymerization inhibitor), And 0.3 part by mass of an ultraviolet absorber (TINUVIN 109, manufactured by Ciba Specialty Chemicals) were uniformly mixed to obtain a photocurable resin composition X for forming a seal part.
The defoaming treatment was carried out by placing the photocurable resin composition X for forming a seal part in a decompression device in an open state while being placed in a container, and reducing the pressure in the decompression device to about 20 Pa and holding it for 10 minutes. . It was about 1400 Pa.s when the viscosity at 25 degrees C of the photocurable resin composition X for sealing part formation was measured.
The above-mentioned photocurable resin composition X for forming a seal portion along a position 5 mm inside from the outer periphery of a soda-lime glass substrate (hereinafter referred to as substrate A) having a length of 610 mm, a width of 610 mm, and a thickness of 2 mm. Was applied to form a seal portion having a thickness of 1 mm.

(Photocurable resin composition for resin layer formation)
A bifunctional polypropylene glycol whose molecular end is modified with ethylene oxide (number average molecular weight calculated from hydroxyl value: 4000) and isophorone diisocyanate are mixed in a molar ratio of 3 to 4, and reacted in the presence of a tin compound catalyst. A urethane acrylate oligomer (hereinafter referred to as UA-2) was obtained by adding 2-hydroxyethyl acrylate in a molar ratio of about 1: 2 to the prepolymer obtained by the reaction. The number of curable groups of UA-2 was 2, the number average molecular weight was about 20,000, and the viscosity at 25 ° C. was 230 Pa · s.

50 parts by mass of UA-2 and 50 parts by mass of 2-hydroxybutyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light ester HOB) were uniformly mixed, and bis (2,4,6-trimethyl) was added to 100 parts by mass of the mixture. 0.2 part by mass of benzoyl) -phenylphosphine oxide (photopolymerization initiator, manufactured by Ciba Specialty Chemicals, IRGACURE 819), 0.04 of 2,5-di-t-butylhydroquinone (polymerization inhibitor) A photocurable resin composition Y for forming a resin layer was obtained by uniformly dissolving 0.3 parts by mass of a mass part and UV absorber (TINUVIN 109, manufactured by Ciba Specialty Chemicals).
The above-mentioned photocurable resin composition Y for resin layer formation is placed in a decompression device in an open state while being put in a container, and the defoaming treatment is performed by reducing the pressure in the decompression device to about 20 Pa and holding for 10 minutes. went. It was 3.5 Pa.s when the viscosity at 25 degrees C of the photocurable resin composition Y for resin layer formation was measured.

Next, using the dispenser, the above-described photocurable resin composition Y for resin layer formation was dispersed and dropped into the region surrounded by the seal portion under the following conditions.
Conditions for dispersion dripping Dropping pitch: 15 mm
Thickness of layer of curable resin composition: 0.8 mm (drop amount: 0.18 cc / point)
Dropping head: 8 × 8 = 64 multi-point nozzles (branch nozzles) arranged in parallel are used Dropping time: Drop tact 3.3 sec × 15 points = 49.5 sec

The substrate A after the dispersion and dropping of the curable resin composition was placed on the upper surface of the lower surface plate on the lower side of the lifting device in the vacuum chamber of the decompression device. A soda lime glass plate (called a substrate B) having the same shape and thickness as that used for the substrate A was electrostatically adsorbed to the lower surface of the upper surface plate on the upper side of the lifting device.
Next, after the vacuum chamber was sealed, the vacuum valve was opened and the chamber was evacuated to 8 Pa. Thereafter, the upper and lower surface plates were brought close to each other by an elevating device in the vacuum chamber, and the substrate A and the substrate B were laminated under reduced pressure to form a lamination precursor C. At this point, the laminated precursor C is pressurized with a pressing force of 30 g / cm ^{2 in} a direction to reduce the distance between the substrates. Thereafter, the laminated precursor C was kept pressurized with the above-mentioned applied pressure, the vacuum valve was closed, the decompressed atmosphere was released, and the inside of the vacuum chamber was returned to atmospheric pressure. The elapsed time after opening the vacuum valve is as follows.
Reduced pressure stacking: 119.5 sec
Vacuum valve closing: 120 sec
Release of reduced pressure atmosphere: 120.1 sec
Note that the pressure gradient (ΔP / ΔT) of the atmospheric pressure of the reduced pressure atmosphere during the reduced pressure lamination and the pressure change amount (ΔP) of the atmospheric pressure from when the reduced pressure lamination is performed until immediately before the release of the reduced pressure atmosphere is performed. It was as follows.
ΔP / ΔT: -0.02 Pa / sec
ΔP: 0.3 Pa

Next, immediately after releasing the vacuum atmosphere, the laminated curable resin composition is cured by irradiating ultraviolet rays from the high-pressure mercury lamp uniformly from the surface direction of the lamination precursor C to cure the laminated glass-like laminate (laminate). Called D).
For the obtained laminate D, the cured resin layer is observed from the substrate B side, and the number of voids in the resin layer and the diameter of the voids, more specifically, the projected shape on the surface of the substrate B The equivalent circle diameter D _pore (hereinafter, “void equivalent circle diameter D _pore ” in the present specification) was measured. The number of voids obtained by measurement and the average value (average void diameter) of the equivalent circle diameter D _pore of the voids are shown in the following table.
The numerical values in the evaluation in the following table are the results of visual observation of the state of the voids of the entire substrate, and the time until void disappearance is determined to be that the void does not disappear even if left for 1 day or longer. 5 indicates that it was determined that the void disappeared within 10 minutes. The other numbers indicate the following:
2: The time until the void disappears is longer than 60 minutes, and it is determined that the void disappears in the meantime if left for about one day.
3: The time until the void disappears is longer than 30 minutes and is determined to be within 60 minutes.
4: The time until the void disappears is longer than 10 minutes and is determined to be within 30 minutes.

(Example 2)
Reduced pressure stacking, vacuum valve closing, release of the reduced pressure atmosphere were performed so that the elapsed time after opening the vacuum valve was as follows, the pressure in the chamber during the reduced pressure stacking was 7 Pa, and the stacking precursor The same procedure as in Example 1 was performed except that the reduced-pressure atmosphere was released in a state where C was not pressurized.
Reduced pressure lamination: 89.5 sec
Vacuum valve closing: 120 sec
Release of decompression atmosphere: 125 sec
Note that the pressure gradient (ΔP / ΔT) of the atmospheric pressure of the reduced pressure atmosphere during the reduced pressure lamination and the pressure change amount (ΔP) of the atmospheric pressure from when the reduced pressure lamination is performed until immediately before the release of the reduced pressure atmosphere is performed. It was as follows.
ΔP / ΔT: -0.02 Pa / sec
ΔP: −1.8 Pa

(Example 3)
Reduced pressure stacking, vacuum valve closing, and release of the reduced pressure atmosphere were performed so that the elapsed time after the vacuum valve was opened was reduced, and that the reduced pressure atmosphere was released without pressurizing the layered precursor C. The same procedure as in Example 1 was performed except for.
Reduced pressure lamination: 89.5 sec
Vacuum valve closing: 90 sec
Release of decompression atmosphere: 95 sec
Note that the pressure gradient (ΔP / ΔT) of the atmospheric pressure of the reduced pressure atmosphere during the reduced pressure lamination and the pressure change amount (ΔP) of the atmospheric pressure from when the reduced pressure lamination is performed until immediately before the release of the reduced pressure atmosphere is performed. It was as follows.
ΔP / ΔT: -0.02 Pa / sec
ΔP: 0.8 Pa

(Example 4)
Reduced pressure stacking, vacuum valve closing, and release of the reduced pressure atmosphere were performed so that the elapsed time after the vacuum valve was opened was reduced, and that the reduced pressure atmosphere was released without pressurizing the layered precursor C. The same procedure as in Example 1 was performed except for.
Reduced pressure stacking: 119.5 sec
Vacuum valve closing: 120 sec
Release of decompression atmosphere: 125 sec
Note that the pressure gradient (ΔP / ΔT) of the atmospheric pressure of the reduced pressure atmosphere during the reduced pressure lamination and the pressure change amount (ΔP) of the atmospheric pressure from when the reduced pressure lamination is performed until immediately before the release of the reduced pressure atmosphere is performed. It was as follows.
ΔP / ΔT: -0.02 Pa / sec
ΔP: 0.8 Pa

(Example 5)
The same procedure as in Example 1 was performed, except that the reduced pressure lamination, the closing of the vacuum valve, and the release of the reduced pressure atmosphere were performed so that the elapsed time after opening the vacuum valve was as follows.
Reduced pressure stacking: 119.5 sec
Vacuum valve closing: 120 sec
Release of decompression atmosphere: 125 sec
Note that the pressure gradient (ΔP / ΔT) of the atmospheric pressure of the reduced pressure atmosphere during the reduced pressure lamination and the pressure change amount (ΔP) of the atmospheric pressure from when the reduced pressure lamination is performed until immediately before the release of the reduced pressure atmosphere is performed. It was as follows.
ΔP / ΔT: -0.02 Pa / sec
ΔP: 0.8 Pa

(Example 6)
Except that the reduced pressure lamination, the vacuum valve closed, the release of the reduced pressure atmosphere were performed so that the elapsed time after opening the vacuum valve would be the following, and the pressure applied to the lamination precursor C was 37 g / cm ^2. The same procedure as in Example 1 was performed.
Reduced pressure stacking: 119.5 sec
Vacuum valve closing: 120 sec
Release of decompression atmosphere: 125 sec
Note that the pressure gradient (ΔP / ΔT) of the atmospheric pressure of the reduced pressure atmosphere during the reduced pressure lamination and the pressure change amount (ΔP) of the atmospheric pressure from when the reduced pressure lamination is performed until immediately before the release of the reduced pressure atmosphere is performed. It was as follows.
ΔP / ΔT: -0.02 Pa / sec
ΔP: 1.2 Pa

(Example 7)
Reduced pressure stacking, vacuum valve closing, release of the reduced pressure atmosphere were performed so that the elapsed time after opening the vacuum valve was as follows, the pressure in the chamber during the reduced pressure stacking was 9 Pa, and the stacking precursor The same procedure as in Example 1 was performed except that the reduced-pressure atmosphere was released in a state where C was not pressurized.
Reduced pressure lamination: 122.5 sec
Vacuum valve closing: 120 sec
Release of decompression atmosphere: 128 sec
Note that the pressure gradient (ΔP / ΔT) of the atmospheric pressure of the reduced pressure atmosphere during the reduced pressure lamination and the pressure change amount (ΔP) of the atmospheric pressure from when the reduced pressure lamination is performed until immediately before the release of the reduced pressure atmosphere is performed. It was as follows.
ΔP / ΔT: 0.2 Pa / sec
ΔP: 2.4 Pa

(Example 8)
An example except that the reduced pressure stacking, closing of the vacuum valve, release of the reduced pressure atmosphere were performed so that the elapsed time after opening the vacuum valve would be below, and the pressure in the chamber at the time of the reduced pressure stacking was 9 Pa. The same procedure as 1 was performed.
Reduced pressure lamination: 122.5 sec
Vacuum valve closing: 120 sec
Release of decompression atmosphere: 128 sec
Note that the pressure gradient (ΔP / ΔT) of the atmospheric pressure of the reduced pressure atmosphere during the reduced pressure lamination and the pressure change amount (ΔP) of the atmospheric pressure from when the reduced pressure lamination is performed until immediately before the release of the reduced pressure atmosphere is performed. It was as follows.
ΔP / ΔT: 0.2 Pa / sec
ΔP: 2.4 Pa

(Example 9)
Reduced pressure stacking, vacuum valve closing, release of the reduced pressure atmosphere were performed so that the elapsed time after opening the vacuum valve was as follows, the pressure in the chamber at the time of reduced pressure stacking was 10 Pa, and the stacking precursor The same procedure as in Example 1 was performed except that the reduced-pressure atmosphere was released in a state where C was not pressurized.
Reduced pressure lamination: 124.5 sec
Vacuum valve closing: 120 sec
Release of decompression atmosphere: 130 sec
Note that the pressure gradient (ΔP / ΔT) of the atmospheric pressure of the reduced pressure atmosphere during the reduced pressure lamination and the pressure change amount (ΔP) of the atmospheric pressure from when the reduced pressure lamination is performed until immediately before the release of the reduced pressure atmosphere is performed. It was as follows.
ΔP / ΔT: 0.2 Pa / sec
ΔP: 3.2 Pa

10: Substrate 20: Seal part

Claims (8)

Prepare two substrates, form a seal part to contain the curable resin composition on the peripheral part on one substrate, and supply the curable resin composition to the area surrounded by the seal part on the substrate And then stacking the other substrate on the supplied curable resin composition in a reduced pressure atmosphere, sandwiching the curable resin composition between the pair of substrates, and sealing to obtain a laminated precursor The laminate precursor is placed in a second pressure atmosphere having an atmospheric pressure of 50 kPa or more higher than the reduced pressure atmosphere, and the curable resin composition is cured in the second pressure atmosphere. And
The procedure for superimposing the other substrate on the supplied curable resin composition is that the atmospheric pressure P is 0.1 to 1000 Pa and the pressure gradient of the atmospheric pressure (ΔP / ΔT (Pa / sec )) Is performed in a reduced pressure atmosphere that satisfies −1 (Pa / sec) ≦ ΔP / ΔT ≦ 0 (Pa / sec),
A pressure change amount (ΔP (Pa) of the atmospheric pressure from when the procedure of superimposing the other substrate on the supplied curable resin composition is performed until immediately before the lamination precursor is placed in the second pressure atmosphere. )) At −1 (Pa) ≦ ΔP ≦ 2 (Pa), and
A method for producing a laminate, comprising placing the laminate precursor in a second pressure atmosphere in a state in which the laminate precursor is pressurized in a direction that reduces the distance between the pair of substrates.   The method for producing a laminate according to claim 1, wherein the curable resin composition has a viscosity of 0.2 to 50 Pa · s.   The laminated body production according to claim 1 or 2, wherein the thickness of the curable resin composition layer in the sealed space of the lamination precursor, which is sealed by the pair of substrates and the seal portion, is 30 to 3000 µm. Method. The viscosity of the curable resin composition is 1 to 14 Pa · s, and the thickness of the curable resin composition layer in the sealed space of the laminated precursor sealed with the pair of substrates and the seal portion. 4 is a pressure of 30 to 37 g / cm ² when the layered precursor is placed in a second pressure atmosphere when the layered precursor is 100 to 2000 μm. The manufacturing method of the laminated body of description.   A time T (sec) from when the procedure for superimposing the other substrate on the supplied curable resin composition is performed until the laminated precursor is placed in the second pressure atmosphere is T ≦ 5 sec. The manufacturing method of the laminated body in any one of Claims 1-4.   The manufacturing method of the laminated body in any one of Claims 1-5 in which the said curable resin composition contains the component which has a vapor pressure higher than the atmospheric pressure of the said pressure reduction atmosphere.   The manufacturing method of the laminated body in any one of Claims 1-6 in which the said seal part is formed using the 2nd curable resin composition whose viscosity is 200-3000 Pa.s.   The method for manufacturing a laminate according to any one of claims 1 to 7, wherein at least one of the two substrates is a transparent substrate.

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