Sealant for dimming element, use of curable resin composition as sealant for dimming element, dimming element, and glass laminate

Abstract

To provide a sealant for dimming element which has superior sealing performance for a dimming element having a dimming material even in a high-temperature environment, and to provide a use method of a curable resin composition as the sealant for dimming element, the dimming element including a cured product of the sealant for dimming element, and laminate glass.SOLUTION: The present invention relates to a sealant for dimming element that is used to seal a dimming element having a dimming material, and the sealant contains curable resin and a radical polymerization initiator, wherein the curable resin includes a (meth)acryl compound, the angle of contact between a cured product of the sealant for dimming element and triethylene glycol di(2-ethyl hexanoate) is 7.5 degrees or larger, and the glass transition temperature of the cured product of the sealant for dimming element is 65°C or larger.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a sealant for a light control device. The present invention also relates to a method for using a curable resin composition as a sealant for a light control device, and a light control device and laminated glass containing a cured product of the sealant for a light control device. [Background technology]

[0002] Light-controlling elements, whose light transmittance changes when a voltage is applied, are used in a wide range of applications, and laminated glass containing light-controlling elements is used, for example, in buildings, automobiles, etc. In such laminated glass, a light-controlling element, which is a light-controlling material sandwiched between films with transparent electrodes, is sandwiched between an interlayer film and a pair of panes of glass. Furthermore, in light-control elements, a sealant is usually used to protect the light-control material from moisture, contaminants, etc. For example, Patent Document 1 discloses that a sealant made of a curable resin is formed by coating on the periphery of a light-control film to protect the liquid crystal layer from moisture, acid, ultraviolet light, etc. Furthermore, Patent Document 2 discloses a method of sealing an element by melt-bonding a barrier material made of PET or the like to at least some layers of a laminate of a functional element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-95084 [Patent Document 2] Special Publication No. 2020-529046 Summary of the Invention [Problem to be solved by the invention]

[0004] When a light-control element is sandwiched between interlayer films in laminated glass, etc., the light-control function at the edges of the light-control element can sometimes be reduced. For this reason, laminated glass with a light-control element is designed to have a sealant between the light-control element and the interlayer film. Meanwhile, in recent years, devices using light-control elements are increasingly required to be reliable when operated in high-temperature environments, but it has been difficult for conventional sealants to provide sufficient sealing performance in high-temperature environments. Furthermore, in the sealing method disclosed in Patent Document 2, there is a risk that the upper and lower substrates may melt when heated. The present invention aims to provide a sealant for a light control device that has excellent sealing performance for a light control device containing a light control material even in a high-temperature environment. The present invention also relates to a method for using a curable resin composition as the sealant for a light control device, and a light control device and laminated glass that contain a cured product of the sealant for a light control device. [Means for solving the problem]

[0005] Disclosure 1 relates to a sealant for photochromic elements used to seal a photochromic element having a photochromic material, the sealant containing a curable resin and a radical polymerization initiator, the curable resin containing a (meth)acrylic compound, a contact angle between a cured product of the sealant for photochromic elements and triethylene glycol di(2-ethylhexanoate) of 7.5 degrees or more, and a glass transition temperature of the cured product of the sealant for photochromic elements of 65°C or more. Disclosure 2 is the sealant for light control devices according to Disclosure 1, in which the contact angle between the cured product of the sealant for light control devices and triethylene glycol di(2-ethylhexanoate) is 8.0 degrees or more. The present disclosure 3 is the sealant for a light control device according to the present disclosure 1 or 2, wherein the cured product of the sealant for a light control device has a glass transition temperature of 80° C. or higher. Disclosure 4 is the sealant for a light control device according to Disclosure 3, wherein the cured product of the sealant for a light control device has a glass transition temperature of 110° C. or higher. The present disclosure 5 is the sealant for a light control device according to the present disclosure 1, 2, 3 or 4, wherein the glass transition temperature of the cured product of the sealant for a light control device is 120° C. or lower. The present disclosure 6 is the sealant for a light control device according to the present disclosure 1, 2, 3, 4 or 5, wherein the (meth)acrylic compound contains a compound having two or more (meth)acryloyl groups in one molecule. Disclosure 7 is the sealant for a light control device according to Disclosure 6, wherein the compound having two or more (meth)acryloyl groups in one molecule contains epoxy (meth)acrylate. Disclosure 8 is a sealant for a light control element according to Disclosure 6 or 7, wherein the compound having two or more (meth)acryloyl groups in one molecule includes a (meth)acrylic compound having one or more aromatic rings in one molecule. A ninth aspect of the present disclosure is the sealant for a light-control device according to the first, second, third, fourth, fifth, sixth, seventh, or eighth aspect of the present disclosure, wherein the light-control material is a solid light-control material. Disclosure 10 relates to the sealant for a light control device according to Disclosure 9, wherein the solid light control material is PDLC. Disclosure 11 is the sealant for a light control device according to Disclosures 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein the resin composition containing a plasticizer is used to seal a light control device disposed around the device. Disclosure 12 relates to a curable resin composition containing a curable resin and a radical polymerization initiator, wherein the curable resin contains a (meth)acrylic compound, and the contact angle between a cured product of the curable resin composition and triethylene glycol di(2-ethylhexanoate) is 7.5 degrees or more, and the cured product of the curable resin composition has a glass transition temperature of 65°C or more, and the curable resin composition is used as a sealant for a light control device. Disclosure 13 is a photochromic element having a photochromic material and a cured product of a sealant for photochromic elements that seals the photochromic material, wherein the contact angle between the cured product of the sealant for photochromic elements and triethylene glycol di(2-ethylhexanoate) is 7.5 degrees or more, and the cured product of the sealant for photochromic elements has a glass transition temperature of 65°C or more. Disclosure 14 is a laminated glass having the light control element of Disclosure 13, an interlayer film sandwiching the light control element, and a pair of glasses sandwiching the interlayer film. The present invention will be described in detail below.

[0006] The present inventors believed that the deterioration of the light-controlling function at the edges of the light-controlling element was due to contact between the light-controlling material and a plasticizer contained in a resin composition constituting an interlayer film, etc., and investigated sealing the edges of the light-controlling element with a sealant that has low compatibility with the plasticizer and has a glass transition temperature after curing equal to or higher than a specific temperature. As a result, they found that the sealant can exhibit excellent sealing performance even in a high-temperature environment, which led to the completion of the present invention.

[0007] In the sealant for light control devices of the present invention, the lower limit of the contact angle between a cured product of the sealant for light control devices and triethylene glycol di(2-ethylhexanoate) is 7.5 degrees. Since the contact angle between the cured product of the sealant for light control devices and triethylene glycol di(2-ethylhexanoate) is 7.5 degrees or more, the sealant for light control devices of the present invention can suppress a decrease in the light control function of the light control device due to contact between the plasticizer and the light control material. The lower limit of the contact angle between the cured product of the sealant for light control devices and triethylene glycol di(2-ethylhexanoate) is preferably 8.0 degrees, and more preferably 9.0 degrees. Furthermore, although there is no particular preferred upper limit to the contact angle between the cured product of the sealant for light control elements and triethylene glycol di(2-ethylhexanoate), the substantial upper limit is 80 degrees. The contact angle between the cured product of the sealing agent for light control elements and triethylene glycol di(2-ethylhexanoate) may be 7.5 to 80 degrees, 8.0 to 80 degrees, or 9.0 to 80 degrees. The contact angle between the cured product of the sealant for light control devices and triethylene glycol di(2-ethylhexanoate) can be measured for a cured product of the sealant for light control devices measuring 10 cm in length, 10 cm in width, and 0.3 mm in thickness by the sessile drop method according to JIS R 3257:1999, using triethylene glycol di(2-ethylhexanoate) as the droplet, at 25°C and 50% RH, using a contact angle meter with a drop volume of 2 μL and after 3 seconds of dropping. For example, a Drop Master (manufactured by Kyowa Interface Science Co., Ltd.) can be used as the contact angle meter. The cured product of the sealant for light control devices, for which the contact angle and the glass transition temperature described later are measured, can be obtained by irradiating or heating the sealant for light control devices. Specific curing methods include irradiating the sealant with light at a wavelength of 340 nm and an illuminance of 100 mW / cm in the case of a photocurable sealant for light control devices. 2 For example, a method of irradiating the photochromic element sealant with light at 120°C for 30 seconds is used, and for a thermosetting photochromic element sealant, a method of heating the photochromic element sealant at 120°C for 60 minutes is used, and for a photothermal curing photochromic element sealant, a combination of these two methods is used. The wavelength of the light irradiated when photocuring the photochromic element sealant is appropriately selected depending on the absorption wavelength of the photoradical polymerization initiator described below.

[0008] Examples of methods for adjusting the contact angle between the cured product of the sealant for light control devices and triethylene glycol di(2-ethylhexanoate) include increasing the content of acrylic compounds in the (meth)acrylic compounds described below, using a compound having a hydroxyl group as the (meth)acrylic compound described below, not using a compound having a long hydrocarbon chain as the (meth)acrylic compound or reducing the content thereof, etc. These methods are carried out while adjusting the balance with the glass transition temperature described below. In this specification, the term "(meth)acrylic" means acrylic or methacrylic, the term "(meth)acrylic compound" means a compound having a (meth)acryloyl group, and the term "(meth)acryloyl" means acryloyl or methacryloyl.

[0009] The sealant for light control devices of the present invention has a lower limit of the glass transition temperature of a cured product of the sealant for light control devices of 65°C. When the glass transition temperature of the cured product is 65°C or higher, the sealant for light control devices of the present invention has excellent sealing performance even in high-temperature environments. From the viewpoint of sealing performance in high-temperature environments, the lower limit of the glass transition temperature of the cured product is preferably 80°C, more preferably 110°C, and even more preferably 120°C. From the viewpoint of conformability to the shape of the film, the upper limit of the glass transition temperature of the cured product is preferably 180° C., more preferably 160° C., and even more preferably 145° C. Furthermore, from the viewpoint of preventing film peeling, the glass transition temperature of the cured product is preferably 120° C. or lower, and more preferably 110° C. or lower. The glass transition temperature of the cured product may be 65°C to 180°C, 65°C to 160°C, 65°C to 145°C, 65°C to 120°C, 65°C to 110°C, 80°C to 180°C, 80°C to 160°C, 80°C to 145°C, 80°C to 120°C, 80°C to 110°C, 110°C to 180°C, 110°C to 160°C, 110°C to 145°C, 110°C to 120°C, 120°C to 180°C, 120°C to 160°C, or 120°C to 145°C. The glass transition temperature of the cured product of the light-controlling sealant can be determined as the temperature at which the loss tangent (tanδ) reaches its maximum value when dynamic viscoelasticity is measured using a dynamic viscoelasticity measuring device under the following conditions: tension mode, test piece width 5 mm, thickness 300 μm, grip width 25 mm, heating rate 10°C / min, temperature range -80°C to 200°C, and frequency 10 Hz. The dynamic viscoelasticity measuring device may be, for example, a DVA-200 (manufactured by IT Instrumentation & Control Co., Ltd.).

[0010] Examples of methods for adjusting the glass transition temperature of the cured product of the sealant for light-controlling elements include increasing the content ratio of methacrylic compounds in the (meth)acrylic compounds described below, using a compound having a rigid skeleton such as a bridged ring structure as the (meth)acrylic compound described below, and increasing the crosslink density of the cured product. These methods are performed while adjusting the balance with the contact angle described above.

[0011] The sealing agent for a light control element of the present invention contains a curable resin. The curable resin contains a (meth)acrylic compound. By including the (meth)acrylic compound as the curable resin, the sealant for a light control device of the present invention is less likely to cause contamination of the light control material (excellent low-contamination properties).

[0012] The (meth)acrylic compound preferably contains a compound having two or more (meth)acryloyl groups in one molecule (hereinafter also referred to as a "difunctional or higher functional (meth)acrylic compound"). By containing the difunctional or higher functional (meth)acrylic compound as the (meth)acrylic compound, the sealant for light control devices of the present invention has excellent curability and adhesiveness.

[0013] Examples of the difunctional or higher (meth)acrylic compound include those having two or more (meth)acryloyl groups in one molecule, such as epoxy (meth)acrylate, (meth)acrylic acid ester compound, and urethane (meth)acrylate. Among these, the difunctional or higher (meth)acrylic compound preferably contains epoxy (meth)acrylate from the viewpoint of low contamination (particularly low contamination of liquid crystal). In this specification, the term "epoxy (meth)acrylate" refers to a compound in which all epoxy groups in an epoxy compound have been reacted with (meth)acrylic acid.

[0014] Examples of the epoxy (meth)acrylate include those obtained by reacting an epoxy compound having two or more epoxy groups in one molecule with (meth)acrylic acid in the presence of a basic catalyst according to a conventional method.

[0015] Examples of the epoxy compound that serves as a raw material for the epoxy (meth)acrylate include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol E type epoxy compounds, bisphenol S type epoxy compounds, 2,2'-diallyl bisphenol A type epoxy compounds, hydrogenated bisphenol type epoxy compounds, propylene oxide-added bisphenol A type epoxy compounds, resorcinol type epoxy compounds, biphenyl type epoxy compounds, sulfide type epoxy compounds, diphenyl ether type epoxy compounds, dicyclopentadiene type epoxy compounds, naphthalene type epoxy compounds, phenol novolac type epoxy compounds, o-cresol novolac type epoxy compounds, dicyclopentadiene novolac type epoxy compounds, biphenyl novolac type epoxy compounds, naphthalene phenol novolac type epoxy compounds, glycidylamine type epoxy compounds, alkyl polyol type epoxy compounds, rubber-modified epoxy compounds, and glycidyl ester compounds.

[0016] Examples of the bifunctional (meth)acrylic acid ester compounds include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate. (meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-added bisphenol A di(meth)acrylate, propylene oxide-added bisphenol A di(meth)acrylate, ethylene oxide-added bisphenol F di(meth)acrylate, dimethylol dicyclopentadienyl di(meth)acrylate, ethylene oxide-modified isocyanuric acid di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth)acrylate, polyester diol di(meth)acrylate, polycaprolactone diol di(meth)acrylate, polybutadiene diol di(meth)acrylate, and the like.

[0017] Examples of the tri- or higher functional (meth)acrylic acid ester compounds include ethylene oxide-added isocyanuric acid tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, propylene oxide-added trimethylolpropane tri(meth)acrylate, caprolactone-modified trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, propylene oxide-added glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(meth)acryloyloxyethyl phosphate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0018] The urethane (meth)acrylate can be obtained, for example, by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group in the presence of a catalytic amount of a tin compound.

[0019] Examples of isocyanate compounds that can be used as raw materials for the urethane (meth)acrylate include isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, tris(isocyanatephenyl)thiophosphate, tetramethylxylylene diisocyanate, and 1,6,11-undecane triisocyanate.

[0020] Furthermore, as the isocyanate compound that is the raw material for the urethane (meth)acrylate, a chain-extended isocyanate compound obtained by reacting a polyol with an excess of an isocyanate compound can also be used. Examples of the polyol include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, and polycaprolactone diol.

[0021] Examples of the (meth)acrylic acid derivative having a hydroxyl group include hydroxyalkyl (meth)acrylates, mono(meth)acrylates of dihydric alcohols, mono(meth)acrylates or di(meth)acrylates of trihydric alcohols, and epoxy (meth)acrylates. Examples of the hydroxyalkyl (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Examples of the dihydric alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol. Examples of the trihydric alcohol include trimethylolethane, trimethylolpropane, and glycerin. Examples of the epoxy(meth)acrylate include bisphenol A type epoxy(meth)acrylate.

[0022] Furthermore, from the viewpoint of being more effective in suppressing a decrease in the light-controlling function of the light-controlling element due to contact between the plasticizer and the light-controlling material, the bifunctional or higher (meth)acrylic compound preferably contains a (meth)acrylic compound having one or more aromatic rings in one molecule, more preferably a (meth)acrylic compound having two or more aromatic rings in one molecule, and even more preferably a (meth)acrylic compound having a bisphenol skeleton. The bisphenol skeleton is preferably a bisphenol A skeleton, a bisphenol F skeleton, or a bisphenol E skeleton, more preferably a bisphenol A skeleton or a bisphenol F skeleton, and even more preferably a bisphenol A skeleton.

[0023] The (meth)acrylic compound may include a monofunctional (meth)acrylic compound having one (meth)acryloyl group in one molecule.

[0024] The preferred lower limit of the content of the difunctional or higher (meth)acrylic compound in 100 parts by mass of the (meth)acrylic compound is 50 parts by mass. When the content of the difunctional or higher (meth)acrylic compound in 100 parts by mass of the (meth)acrylic compound is 50 parts by mass or more, the resulting sealant for light control devices will have better curability, adhesion, and low contamination properties. The more preferred lower limit of the content of the difunctional or higher (meth)acrylic compound in 100 parts by mass of the (meth)acrylic compound is 66 parts by mass. It is particularly preferred that the content of the difunctional or higher (meth)acrylic compound in 100 parts by mass of the (meth)acrylic compound is 100 parts by mass, i.e., the (meth)acrylic compound is composed solely of the difunctional or higher (meth)acrylic compound. The content of the di- or higher functional (meth)acrylic compound in 100 parts by mass of the (meth)acrylic compound may be 50 parts by mass to 100 parts by mass, or may be 66 parts by mass to 100 parts by mass.

[0025] Since it becomes easier to adjust the balance between the contact angle and the glass transition temperature and the resulting sealant for light control devices has better sealing performance in high-temperature environments, it is preferred that the curable resin does not contain, as the (meth)acrylic compound, any compound having a homopolymer glass transition temperature of less than 30°C, any compound having a homopolymer glass transition temperature of 30°C or more and less than 65°C, or contains 40 mass% or less of compounds having a homopolymer glass transition temperature of 30°C or more and less than 65°C, and 30 mass% or more and 70 mass% or less of compounds having a homopolymer glass transition temperature of 120°C or more.

[0026] A preferred lower limit of the content of the (meth)acrylic compound in 100 parts by mass of the curable resin is 50 parts by mass. When the content of the (meth)acrylic compound is 50 parts by mass or more, the resulting sealant for light control devices has excellent low-staining properties. A more preferred lower limit of the content of the (meth)acrylic compound is 66 parts by mass. It is particularly preferred that the content of the (meth)acrylic compound in 100 parts by mass of the curable resin is 100 parts by mass, that is, the curable resin is composed solely of the (meth)acrylic compound. The content of the (meth)acrylic compound in 100 parts by mass of the curable resin may be 50 parts by mass to 100 parts by mass, or may be 66 parts by mass to 100 parts by mass.

[0027] The preferred lower limit of the total content of the curable resins in 100 parts by mass of the sealant for light control devices of the present invention is 66 parts by mass, and the preferred upper limit is 99 parts by mass. When the total content of the curable resins is within this range, the resulting sealant for light control devices will have better curability and adhesiveness.

[0028] The sealing agent for a light-adjusting element of the present invention contains a radical polymerization initiator. As the radical polymerization initiator, a photoradical polymerization initiator that generates radicals upon irradiation with light or a thermal radical polymerization initiator that generates radicals upon heating can be used. Among these, a photoradical polymerization initiator is preferably used.

[0029] Examples of the photoradical polymerization initiator include benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, and thioxanthone compounds. Specific examples of the photoradical polymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-((4-methylphenyl)methyl)-1-(4-(4-morpholinyl)phenyl)-1-butanone, 2,2-dimethoxy-1,2-diphenylethan-1-one, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2-methyl-1-(4-methylthiophenyl) 2-morpholinopropan-1-one, 1-(4-(2-hydroxyethoxy)-phenyl)-2-hydroxy-2-methyl-1-propan-1-one, 1-(4-(phenylthio)phenyl)-1,2-octanedione 2-(O-benzoyloxime), 2-(acetoxyimino)-1-(4-(4-(2-hydroxyethoxy)phenylthio)phenyl)propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4-dimethylthioxanthen-9-one, and the like.

[0030] Examples of the thermal radical polymerization initiator include those composed of an azo compound, an organic peroxide, etc. Among them, from the viewpoint of suppressing contamination of the light-modulating material, an initiator composed of an azo compound (hereinafter also referred to as "azo initiator") is preferred. The thermal radical polymerization initiators may be used alone or in combination of two or more.

[0031] Specific examples of the azo compounds include those having a structure in which multiple units of polyalkylene oxide, polydimethylsiloxane, or the like are bonded via azo groups, polycondensates of 2,2'-azobis(2,4-dimethylvaleronitrile), 4,4'-azobis(4-cyanovaleric acid), 4,4'-azobis(4-cyanopentanoic acid) and polyalkylene glycol, and polycondensates of 4,4'-azobis(4-cyanopentanoic acid) and polydimethylsiloxane having a terminal amino group. Examples of the azo initiator include VPE-0201, VPE-0401, VPE-0601, VPS-0501, VPS-1001, V-65, and V-501 (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0032] Examples of the organic peroxide include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, peroxyesters, diacyl peroxides, and peroxydicarbonates.

[0033] The content of the radical polymerization initiator is preferably 0.01 parts by mass at the lower limit and 10 parts by mass at the upper limit relative to 100 parts by mass of the curable resin. By using the radical polymerization initiator in this range, the resulting sealant for light-adjusting elements has better storage stability and curability. The lower limit of the radical polymerization initiator content is more preferably 0.1 parts by mass, and the upper limit is more preferably 7 parts by mass. The content of the radical polymerization initiator relative to 100 parts by mass of the curable resin may be 0.01 parts by mass to 10 parts by mass, 0.01 parts by mass to 7 parts by mass, 0.1 parts by mass to 10 parts by mass, or 0.1 parts by mass to 7 parts by mass.

[0034] The sealing agent for a light-controlling element of the present invention may further contain additives such as a heat curing agent, a curing accelerator, a light-shielding agent, a filler, a silane coupling agent, a stress relaxation agent, a reactive diluent, a thixotropic agent, a spacer, an antifoaming agent, a leveling agent, and a polymerization inhibitor, as necessary.

[0035] The sealing agent for a light control element of the present invention can be produced, for example, by mixing a curable resin, a radical polymerization initiator, and optional additives using a mixer. Examples of the mixer include a homodisper, a homomixer, a universal mixer, a planetary mixer, a kneader, and a three-roll mixer.

[0036] The sealant for a light-controlling element of the present invention is used to seal a light-controlling element having a light-controlling material, and is preferably used when the light-controlling material is a solid light-controlling material. PDLC (polymer dispersed liquid crystal) is preferably used as the solid light-controlling material. The sealing portion made by the sealant for a light-controlling element of the present invention is preferably provided around the light-controlling material. In this specification, the term "solid" means that the material does not have fluidity at 25°C.

[0037] Furthermore, the sealant for a light control element of the present invention is preferably used to seal a light control element surrounding a resin composition containing a plasticizer, and is more preferably used to seal a light control element surrounding a polyvinyl butyral resin composition containing a plasticizer.

[0038] FIG. 1 is a cross-sectional view schematically illustrating an example of an embodiment in which a light control element surrounded by a resin composition containing a plasticizer is sealed using the sealant for light control elements of the present invention. In FIG. 1, a light control element is formed by sandwiching a light control material 1 between films 2 with transparent electrodes. A seal portion 3 made of the sealant for light control elements is provided at the edge of the light control element, and therefore a resin composition 4 (such as an interlayer film) containing a plasticizer is disposed around the light control element without coming into contact with the light control material 1. By using the sealant for light control elements of the present invention, which has low compatibility with plasticizers and a high glass transition temperature after curing, as the sealant for light control elements that forms the seal portion 3, excellent sealing performance can be achieved even in high-temperature environments.

[0039] Examples of the plasticizer include organic acid esters, organic phosphates, and organic phosphites.

[0040] Examples of the organic acid esters include triethylene glycol di(2-ethylbutyrate), triethylene glycol di(2-ethylhexanoate), triethylene glycol dicaprylate, triethylene glycol di(n-octanoate), triethylene glycol di(n-heptanoate), tetraethylene glycol di(n-heptanoate), tetraethylene glycol di(2-ethylhexanoate), dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di(2-ethylbutyrate), 1,3-propylene glycol di(2-ethylbutyrate), 1,4-butylene glycol di(2-ethylbutyrate), Examples of the additive include diethylene glycol di(2-ethylbutyrate), diethylene glycol di(2-ethylhexanoate), dipropylene glycol di(2-ethylbutyrate), triethylene glycol di(2-ethylpentanoate), tetraethylene glycol di(2-ethylbutyrate), diethylene glycol dicaprylate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, oil-modified sebacic acid alkyd, a mixture of a phosphate ester and an adipate ester, and a mixed adipate ester prepared from an alkyl alcohol having 4 to 9 carbon atoms and a cyclic alcohol having 4 to 9 carbon atoms.

[0041] The organic phosphate or organic phosphite ester may be a compound obtained by a condensation reaction between phosphoric acid or phosphorous acid and an alcohol, and among these, a compound obtained by a condensation reaction between an alcohol having 1 to 12 carbon atoms and phosphoric acid or phosphorous acid is preferred. Examples of the alcohol having 1 to 12 carbon atoms include methanol, ethanol, butanol, hexanol, 2-ethylbutanol, heptanol, octanol, 2-ethylhexanol, decanol, dodecanol, butoxyethanol, butoxyethoxyethanol, and benzyl alcohol. Specific examples of the organic phosphate ester or organic phosphite ester include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tri(2-ethylhexyl) phosphate, tri(butoxyethyl) phosphate, tri(2-ethylhexyl) phosphite, isodecylphenyl phosphate, and triisopropyl phosphate.

[0042] In particular, the sealant for a light control element of the present invention is suitably used to seal a light control element around which a resin composition containing triethylene glycol di(2-ethylhexanoate) as a plasticizer is placed.

[0043] The present invention also provides a use of a curable resin composition containing a curable resin and a radical polymerization initiator, wherein the curable resin contains a (meth)acrylic compound, the contact angle between a cured product of the curable resin composition and triethylene glycol di(2-ethylhexanoate) being 7.5 degrees or more, and the glass transition temperature of the cured product of the curable resin composition being 65°C or more, as a sealant for a light control device. The present invention also provides a light control element having a light control material and a cured product of a sealant for light control elements that seals the light control material, wherein the contact angle between the cured product of the sealant for light control elements and triethylene glycol di(2-ethylhexanoate) is 7.5 degrees or more, and the glass transition temperature of the cured product of the sealant for light control elements is 65°C or more. Additionally, the present invention also includes a laminated glass comprising the light control element of the present invention, an interlayer film sandwiching the light control element therebetween, and a pair of glass sheets sandwiching the interlayer film therebetween. [Effects of the Invention]

[0044] The present invention provides a sealant for a light control device that has excellent sealing performance for a light control device containing a light control material even in a high-temperature environment. The present invention also provides a method for using a curable resin composition as a sealant for a light control device, and a light control device and laminated glass that contain a cured product of the sealant for a light control device. [Brief explanation of the drawings]

[0045] [Figure 1] FIG. 1 is a cross-sectional view schematically showing an example of an embodiment in which a light control element surrounded by a resin composition containing a plasticizer is sealed using the sealing agent for a light control element of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0046] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0047] (Synthesis of resorcinol-type epoxy acrylate (curable resin A)) A mixture of 1,000 parts by weight of a resorcinol-type epoxy compound (Nagase ChemteX Corporation, "Denacol EX-201"), 2 parts by weight of p-methoxyphenol as a polymerization inhibitor, 2 parts by weight of triethylamine as a reaction catalyst, and 649 parts by weight of acrylic acid was refluxed and stirred at 90°C for 5 hours while air was introduced. 100 parts by weight of the resulting reaction product was filtered through a column packed with 10 parts by weight of a natural combination of quartz and kaolin (Hoffman Minerals Corporation, "Cyritin V85") to adsorb ionic impurities in the reaction product, yielding a resorcinol-type epoxy acrylate (curable resin A).

[0048] (Synthesis of resorcinol-type epoxy methacrylate (curable resin B)) Resorcinol-type epoxy methacrylate (curable resin B) was obtained in the same manner as in the above "(Synthesis of resorcinol-type epoxy acrylate (curable resin A))" except that 774 parts by mass of methacrylic acid was used instead of 649 parts by mass of methacrylic acid.

[0049] (Examples 1 to 13, Comparative Examples 1 to 5) According to the compounding ratios shown in Tables 1 to 3, each material was stirred with a planetary stirrer and then uniformly mixed with a ceramic triple roll to obtain sealants for light control elements of Examples 1 to 13 and Comparative Examples 1 to 5. Awatori Rentaro (manufactured by Thinky Corporation) was used as the planetary stirrer. The sealants for light control elements obtained in Examples 1, 3 to 13 and Comparative Examples 1 to 5 were subjected to a wavelength of 340 nm and an illuminance of 100 mW / cm using MDB15001N-03 (manufactured by Sun Energy Co., Ltd.). 2 The sealant for light control devices obtained in Example 2 was irradiated with light of wavelength 340 nm and illuminance 100 mW / cm using MDB15001N-03 (manufactured by Sun Energy Co., Ltd.) for 30 seconds to obtain a cured product. 2 After irradiating the coating with light for 30 seconds, the coating was heated at 120°C for 60 minutes to obtain a cured product.

[0050] (Contact angle between a cured product of a sealant for light control elements and triethylene glycol di(2-ethylhexanoate)) For a cured product of the sealant for light control devices measuring 10 cm in length, 10 cm in width, and 0.3 mm in thickness, the contact angle between the resulting cured product of the sealant for light control devices and triethylene glycol di(2-ethylhexanoate) was measured using the sessile drop method according to JIS R 3257:1999. The contact angle was measured using a contact angle meter at 25°C and 50% RH, with a drop volume of 2 μL and a time delay of 3 seconds. The contact angle meter used was a Drop Master (manufactured by Kyowa Interface Science Co., Ltd.). The results are shown in Tables 1 to 3.

[0051] (Glass transition temperature of cured sealant for light control devices) The cured product of the light-controlling sealant was measured for dynamic viscoelasticity using a dynamic viscoelasticity measuring device under the following conditions: tension mode, test piece width 5 mm, thickness 300 μm, grip width 25 mm, heating rate 10°C / min, temperature range -80°C to 200°C, frequency 10 Hz, and the glass transition temperature was determined. The dynamic viscoelasticity measuring device used was a DVA-200 (manufactured by IT Instrumentation & Control Co., Ltd.). The results are shown in Tables 1 to 3.

[0052] <Evaluation> The obtained sealant for a light control device was evaluated as follows, and the results are shown in Tables 1 to 3.

[0053] (Sealing performance) (1) Film peeling prevention The obtained sealant for light control devices was applied to a liquid crystal light control film ("nanotec-Film Type 1" manufactured by Kyushu Nanotec Co., Ltd.) having a width of 2 cm and a length of 10 cm to a thickness of 300 μm. Next, the sealants for light control devices obtained in Examples 1, 3 to 13, and Comparative Examples 1 to 5 were applied to a liquid crystal light control film ("nanotec-Film Type 1" manufactured by Kyushu Nanotec Co., Ltd.) using MDB15001N-03 (manufactured by Sun Energy Co., Ltd.) at a wavelength of 340 nm and an illuminance of 100 mW / cm. 2 The sealant for light control devices obtained in Example 2 was cured by irradiating it with light of wavelength 340 nm and illuminance 100 mW / cm for 30 seconds to obtain a test piece. 2 After irradiating the film with light for 30 seconds, it was cured by heating at 120°C for 60 minutes to obtain a test piece. The liquid crystal light control film in the obtained test piece was visually inspected for peeling, and the film peel resistance was evaluated according to the following criteria. ○: No peeling of the liquid crystal light control film was confirmed △: When peeling of the LCD light control film is confirmed in some areas ×: If the LCD light control film was completely peeled off

[0054] (2) Low contamination in high temperature environments The obtained sealant for light control devices was applied to the periphery of a light control film (manufactured by Gauzy) in a width of 500 μm, and then cured to obtain a light control layer with a sealed periphery. The sealants for light control devices obtained in Examples 1, 3 to 13, and Comparative Examples 1 to 5 were cured using MDB15001N-03 (manufactured by Sun Energy Co., Ltd.) at a wavelength of 340 nm and an illuminance of 100 mW / cm. 2 The sealant for light control devices obtained in Example 2 was cured by irradiating it with light of wavelength 340 nm and illuminance 100 mW / cm for 30 seconds. 2 After irradiating the layer with light for 30 seconds, it was cured by heating for 60 minutes at 120° C. The resulting light-controlling layer was sandwiched between an interlayer (S-LEC™ Film, manufactured by Sekisui Chemical Co., Ltd.) and glass, and laminated by pressure bonding at a temperature of 90° C. to obtain a test specimen. The obtained test piece was left at 80°C for 100 hours, and then the staining distance from the end of the light-controlling layer was measured, and the low staining property at 80°C was evaluated according to the following criteria. ◎: When the contamination distance is less than 3 mm ○: When the contamination distance is 3 mm or more and less than 10 mm ×: When the contamination distance is 10 mm or more Furthermore, for test pieces obtained in the same manner, the staining distance from the end of the photochromic layer was measured even after leaving the test pieces at 110°C for 100 hours, and the low staining property at 110°C was evaluated according to the following criteria. ◎: When the contamination distance is less than 3 mm ○: When the contamination distance is 3 mm or more and less than 7 mm △: When the contamination distance is 7mm or more and less than 10mm ×: When the contamination distance is 10 mm or more

[0055] [Table 1]

[0056] [Table 2]

[0057] [Table 3] [Industrial Applicability]

[0058] The present invention provides a sealant for a light control device that has excellent sealing performance for a light control device containing a light control material even in a high-temperature environment. The present invention also provides a method for using a curable resin composition as a sealant for a light control device, and a light control device and laminated glass that contain a cured product of the sealant for a light control device. [Explanation of symbols]

[0059] 1. Photochromic materials 2. Transparent electrode film 3 Seal part 4. Resin composition containing plasticizer

Claims

1. A sealant for a light control element used to seal a light control element having a light control material, comprising: Contains a curable resin and a radical polymerization initiator, the curable resin contains a (meth)acrylic compound, the contact angle between the cured product of the sealant for light-adjusting elements and triethylene glycol di(2-ethylhexanoate) is 7.5 degrees or more; The glass transition temperature of the cured product of the sealant for light-adjusting elements is 65°C or higher. A sealant for a light-adjusting element, characterized in that:

2. 2. The sealant for light control devices according to claim 1, wherein a contact angle between a cured product of the sealant for light control devices and triethylene glycol di(2-ethylhexanoate) is 8.0 degrees or more.

3. 3. The sealant for light control devices according to claim 1, wherein the cured product of the sealant for light control devices has a glass transition temperature of 80° C. or higher.

4. 4. The sealant for a light control device according to claim 3, wherein the cured product of the sealant for a light control device has a glass transition temperature of 110° C. or higher.

5. 3. The sealant for light control devices according to claim 1, wherein the cured product of the sealant for light control devices has a glass transition temperature of 120° C. or lower.

6. 3. The sealant for a light-adjusting element according to claim 1, wherein the (meth)acrylic compound includes a compound having two or more (meth)acryloyl groups in one molecule.

7. 7. The sealant for a light-adjusting element according to claim 6, wherein the compound having two or more (meth)acryloyl groups in one molecule includes an epoxy (meth)acrylate.

8. The sealant for a light-controlling element according to claim 6 , wherein the compound having two or more (meth)acryloyl groups in one molecule includes a (meth)acrylic compound having one or more aromatic rings in one molecule.

9. 3. The sealant for a light-adjusting element according to claim 1, wherein the light-adjusting material is a solid light-adjusting material.

10. The sealant for a light-controlling element according to claim 9, wherein the solid light-controlling material is PDLC.

11. 3. The sealant for a light-adjusting element according to claim 1, wherein the resin composition containing a plasticizer is used to seal a light-adjusting element disposed around the light-adjusting element.

12. A curable resin composition containing a curable resin and a radical polymerization initiator, the curable resin contains a (meth)acrylic compound, the contact angle between the cured product of the curable resin composition and triethylene glycol di(2-ethylhexanoate) is 7.5 degrees or more; The glass transition temperature of the cured product of the curable resin composition is 65°C or higher.

1. Use of a curable resin composition as a sealant for a light-control element.

13. A light-adjusting element having a light-adjusting material and a cured product of a sealant for a light-adjusting element that seals the light-adjusting material, the contact angle between the cured product of the sealant for light-adjusting elements and triethylene glycol di(2-ethylhexanoate) is 7.5 degrees or more; The glass transition temperature of the cured product of the sealant for light-adjusting elements is 65°C or higher. A light control element characterized by:

14. 14. A laminated glass comprising: the light control element according to claim 13; an interlayer film sandwiching the light control element; and a pair of glass sheets sandwiching the interlayer film.

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