Composition for hardcoats, production method therefor, hardcoat, and substrate

Abstract

Provided are: a composition for hardcoats which contains a silsesquioxane derivative represented by formula (1), the silsesquioxane derivative represented by formula (1) having a degree of condensation of 94% or less, and which, through curing, gives a cured object having a curing shrinkage of 9% or less; a method for producing the composition; a hardcoat obtained by curing the composition for hardcoats; and a substrate including the hardcoat. In formula (1), u and / or v is a positive number.

Description

Hard coat composition and method for producing the same, hard coat, and substrate

[0001] The present disclosure relates to a composition for a hard coat and a method for producing the same, a hard coat, and a substrate.

[0002] Flexible devices such as foldable devices and rollable devices are becoming more common. The displays of these devices require flexibility, transparency, surface hardness, and other properties. When a plastic film is used in a flexible display, a hard coat layer with high surface hardness is often provided to prevent scratches. Ultra-thin glass films with high hardness and flexibility are sometimes used as substrates. Even in these cases, a hard coat layer is provided to maintain surface hardness and prevent cracking or shattering upon impact.

[0003] The shape of the foldable display can be, for example, an infold shape (inward bending) where the hard-coated surface is on the inside, an outfold shape (outward bending) where the hard-coated surface is on the outside, or a tri-fold shape where the hard-coated surface is on both the inside and outside (Z-folded).

[0004] Examples of hard coating compositions with high surface hardness include acrylates, epoxy resins, and silsesquioxane derivatives. In addition to various resin films, tempered glass is sometimes used as a substrate. However, tempered glass cannot be used as a substrate because polymerization inhibition occurs in cationic or anionic curing systems.

[0005] As conventional hard coats, several outfoldable hard coats have been disclosed. Patent Document 1 discloses a method for producing a laminated film, which includes the steps of: conveying a resin support having a thickness of 80 μm or less; applying an inorganic layer-forming coating liquid containing silanol and a water-soluble curing agent that dehydrates and condenses the silanol onto the support to form a layer for forming an inorganic layer; drying the inorganic layer-forming layer to form an inorganic layer; applying an organic layer-forming coating liquid containing an actinic ray-curable resin onto the inorganic layer of the support to form a layer for forming an organic layer; and irradiating the organic layer-forming layer with actinic rays to form an organic layer. Furthermore, Patent Document 2 discloses an optical film having at least one hard coat layer on a transparent support, wherein at least one of the hard coat layers is a layer formed from a composition containing: (A) a bifunctional (meth)acrylate compound having a molecular weight in the range of 210 to 500 and having at least one of an alicyclic, aromatic ring, and heterocyclic structure in the molecule; (B) a polyfunctional acrylate compound having three or more (meth)acryloyl groups; and (C) a photopolymerization initiator. Furthermore, Patent Document 3 discloses a laminate for a display device having a base layer, a first layer, and a second layer in this order, wherein the luminous reflectance of specularly reflected light when light is incident on the surface of the laminate for a display device on the side of the second layer at an incident angle of 60° is 10.0% or less, and the absolute value of the difference between the yellowness index YI1 of transmitted light in a direction at 60° to the normal to the surface of the laminate for a display device on the side of the second layer and the yellowness index YI2 of transmitted light in a direction at 15° to the normal to the surface of the laminate for a display device on the side of the second layer is 3.0 or less.

[0006] JP 2015-29957 A JP 2008-105191 A International Publication No. 2022 / 210725

[0007] The aforementioned outfold and tri-fold shapes require higher flexibility than the infold shape, and increasing hardness leads to cracking when bent. On the other hand, increasing flexibility reduces hard coat properties and makes the film more susceptible to scratches. Patent Document 1 discloses the brittleness of hard coat films made from silicon alkoxides when bent, but does not describe outward bending or continuous bending. Patent Document 2 discloses the brittleness of hard coat films containing multifunctional acrylates when bent, but does not describe resistance to continuous bending. Patent Document 3 discloses the continuous bending property of a coating agent whose main component is an acrylate having a urethane skeleton, but does not mention hardness.

[0008] The present disclosure has been made in view of the above, and aims to provide a composition for hard coating that provides a hard coating having excellent flex resistance, a method for producing the same, a hard coating obtained by curing the composition for hard coating, and a substrate provided with the hard coating.

[0009] The means for solving the above problems include the following aspects: <1> A composition for hard coat, comprising a silsesquioxane derivative represented by the following formula (1), wherein the condensation rate of the silsesquioxane derivative represented by the formula (1) is 94% or less, and the cure shrinkage rate of a cured product obtained after curing is 9% or less:

[0010] (In formula (1), R １ and R ２ are each independently an alkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 3 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, or an aralkylene group having 7 to 12 carbon atoms; R ３ is an alkyl group having 1 to 6 carbon atoms, and R ４ and R ５ are each independently a hydrogen atom, a saturated or unsaturated chain hydrocarbon group having 1 to 20 carbon atoms, a saturated or unsaturated cyclic hydrocarbon group having 3 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms; R ６is an organic group having 2 to 12 carbon atoms and at least one of an ethylenically unsaturated bond and a carbon-carbon triple bond, and R ７ and R ８ are each independently an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms, and a plurality of R ５ may be the same or different, and multiple R ７ may be the same or different, and multiple R ８ may be the same or different, R １ ~R ８ may each independently be partially substituted with a substituent or a halogen atom, and t, u, v, w, x, y, and z each independently represent 0 or a positive number, and at least one of u and v is a positive number.

[0011] <2> The hard coat composition according to <1>, wherein, in matrix-assisted laser desorption / ionization time-of-flight mass spectrometry of the silsesquioxane derivative, the sum of the peak heights of the cage silsesquioxane derivative having 8 silicon atoms, the cage silsesquioxane derivative having 10 silicon atoms, and the cage silsesquioxane derivative having 12 silicon atoms is less than 18% of the sum of all peak heights, based on the peak intensity ratios shown in a region of molecular weight of 4,000 or less. <3> The hard coat composition according to <1> or <2>, wherein a 10 μm-thick hard coat obtained by curing the hard coat composition on a substrate does not break even after 50,000 consecutive outward bending cycles with a bending radius R of 5 mm. <4> The hard coat composition according to any one of <1> to <3>, wherein the indentation modulus at 23°C of the cured product obtained after curing is 4 GPa or more. <5> The composition for hard coating according to any one of <1> to <4>, further comprising a polymerization initiator. <6> A hard coating obtained by curing the composition for hard coating according to any one of <1> to <5>. <7> A substrate provided with the hard coating according to <6>. <8> R ｎ Six ｐ(n represents an integer of 0 to 3, p represents an integer of 1 to 4, n+p=4, R represents a group bonded to a silicon atom in the silsesquioxane derivative via a carbon atom, and X represents a hydrolyzable group), using an organic solvent and adding 1.5 molar equivalents or more of water relative to the total amount of hydrolyzable groups in the organosilicon compound.

[0012] According to the present disclosure, it is possible to provide a composition for hard coating that provides a hard coating having excellent flex resistance, a method for producing the same, a hard coating obtained by curing the composition for hard coating, and a substrate provided with the hard coating.

[0013] Hereinafter, embodiments for carrying out the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the present disclosure. In this specification, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in this specification, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In addition, in numerical ranges described in this specification, the upper or lower limit value of that numerical range may be replaced with a value shown in an example. In this specification, a combination of two or more preferred aspects is a more preferred aspect.

[0014] In this specification, R in formula (1) １ ~R ８ may each independently be partially substituted with a substituent or a halogen atom. １ ~R ８may each independently be partially substituted with an alkyl group, an aryl group, an aralkyl group, a vinyl group, an epoxy group, an oxetanyl group, a hydroxyl group, an amino group, an alkylamino group, an arylamino group, an aralkylamino group, an ammonium group, a thiol group, an isocyanurate group, a ureido group, an isocyanate group, a carboxy group, an acid anhydride group, or a halogen atom. １ ~R ８ may each independently be unsubstituted, for example, R １ ~R ３ or R ６ ~R ８ (Preferably, R １ ~R ３ and R ６ ~R ８ ) may be unsubstituted.

[0015] [Hard Coat Composition] The hard coat composition according to the present disclosure contains a silsesquioxane derivative represented by the following formula (1), wherein the condensation rate of the silsesquioxane derivative represented by the formula (1) is 94% or less, and the cure shrinkage rate of the cured product obtained after curing is 9% or less.

[0016] (In formula (1), R １ and R ２ are each independently an alkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 3 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, or an aralkylene group having 7 to 12 carbon atoms; R ３ is an alkyl group having 1 to 6 carbon atoms, and R ４ and R ５ are each independently a hydrogen atom, a saturated or unsaturated chain hydrocarbon group having 1 to 20 carbon atoms, a saturated or unsaturated cyclic hydrocarbon group having 3 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms; R ６ is an organic group having 2 to 12 carbon atoms and at least one of an ethylenically unsaturated bond and a carbon-carbon triple bond, and R ７ and R ８are each independently an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms, and a plurality of R ５ may be the same or different, and multiple R ７ may be the same or different, and multiple R ８ may be the same or different, R １ ~R ８ may each independently be partially substituted with a substituent or a halogen atom, and t, u, v, w, x, y, and z each independently represent 0 or a positive number, and at least one of u and v is a positive number.

[0017] As described above, conventional hard coat compositions have insufficient flex resistance when cured, particularly when bent into an outfold shape or a tri-fold shape. As a result of extensive research, the present inventors have found that by adopting the above-described configuration, it is possible to provide a hard coat composition that provides excellent flex resistance in the resulting hard coat. It is estimated that, when at least one of u and v in formula (1) is a positive number, the condensation rate of the silsesquioxane derivative represented by formula (1) is 94% or less, and the cure shrinkage rate of the cured product obtained after curing is 9% or less, an appropriate crosslinked structure can be obtained after curing, thereby enabling the production of a hard coat with excellent flex resistance.

[0018] Furthermore, the hard coat composition according to the present disclosure has excellent surface hardness, which makes it difficult for breakage to occur even when repeatedly bent in the mountain fold direction, thereby enabling the production of a highly durable display or lens.

[0019] (Condensation Rate of Silsesquioxane Derivative Represented by Formula (1)) The condensation rate of the silsesquioxane derivative represented by formula (1) is 94% or less, and from the viewpoints of the flex resistance of the hard coat obtained (hereinafter also simply referred to as "flex resistance") and the surface hardness of the hard coat obtained (hereinafter also simply referred to as "surface hardness"), it is preferably 50% to 94%, more preferably 70% to 93%, and particularly preferably 75% to 92%.

[0020] The method for measuring the condensation rate of a silsesquioxane derivative in the present disclosure is as follows. ２９ From the results of Si NMR spectrum measurement (measuring device: AVANCE III 400 manufactured by Bruker Biospin), the area ratios of T3, T2, T1, T0, D2, D1, and D0 are determined, and the condensation rate is calculated using the following formula. ２９ In the results of Si NMR spectrum measurement, the peaks are derived from a structure in which all three hydrolyzable groups bonded to Si are condensed, T2 and T1 are derived from a structure in which two and one hydrolyzable groups bonded to Si are condensed, respectively, and TO is a peak derived from a structure in which no hydrolyzable group bonded to Si is condensed. Similarly, D2 and D1 are derived from a structure in which all two hydrolyzable groups bonded to Si are condensed, and one hydrolyzable group is condensed, and DO is a peak derived from a structure in which no hydrolyzable group is condensed. Condensation rate (%) = (0 x TO + 1 x T1 + 2 x T2 + 3 x T3 + 0 x DO + 1 x D1 + 2 x D2) / {3 x (TO + T1 + T2 + T3) + 2 x (DO + D1 + D2)} x 100

[0021] (Curing Shrinkage Rate) The hard coat composition according to the present disclosure has a curing shrinkage rate of 9% or less, and from the viewpoints of flex resistance and surface hardness, preferably 8% or less, more preferably 7% or less, and particularly preferably 0% to 6.5%.

[0022] The method for measuring the cure shrinkage of the cured product obtained after curing the hard coat composition of the present disclosure is as follows. In accordance with JIS Z8804:2012, the specific gravity of the composition before curing at 25°C was measured using a pycnometer. Furthermore, in accordance with the submerged weighing method defined in JIS Z8807, the specific gravity of the cured product at 25°C was measured. The specific gravity measured as described above was applied to the following formula to determine the cure shrinkage: Cure shrinkage (%) = (((specific gravity of cured product) - (specific gravity before curing)) / (specific gravity before curing)) x 100

[0023] (Indentation Elastic Modulus of Cured Product) From the viewpoint of flex resistance and surface hardness, the indentation elastic modulus at 23°C of the cured product obtained after curing of the hard coat composition according to the present disclosure is preferably 4 GPa or more, more preferably 4.05 GPa or more, even more preferably 4.05 GPa to 20.0 GPa, and particularly preferably 4.1 GPa or more and 15.0 GPa or less.

[0024] The indentation modulus at 23° C. of a cured product of a hard coat composition according to the present disclosure is measured as follows. When the hard coat composition is not photocurable, the following photocurable composition is prepared and then measured.

[0025] <Preparation of Photocurable Composition> 0.03 parts by mass of 2-hydroxy-2-methyl-1-phenylpropan-1-one and 1 part by mass of propylene glycol monobutyl ether are added to 1 part by mass of the hard coat composition, and the mixture is stirred with a planetary centrifugal mixer to prepare a photocurable composition.

[0026] <Preparation of Photocured Film> The hard coat composition or photocurable composition prepared as described above is applied to a 50 μm thick PET film (Cosmoshine A4300, manufactured by Toyobo Co., Ltd.). Specifically, the hard coat composition or photocurable composition is applied using a No. 8 bar coater, and the applied hard coat composition or photocurable composition is dried at 60°C for 10 minutes, and then irradiated with ultraviolet light under the following conditions to cure, thereby preparing a photocured film with a thickness of approximately 5 μm. -Ultraviolet Light Irradiation Conditions- Lamp: High-pressure mercury lamp (ECS-4011GX, manufactured by iGraphics Co., Ltd.) Lamp height: 10 cm Conveyor speed: 5.75 m / min Integrated light intensity per pass: 360 mJ / cm ２ (UV-A, measured value using UV POWER PUCK II manufactured by EIT) Atmosphere: Air Number of passes: 10

[0027] <Measurement of Indentation Elastic Modulus> Using the obtained photocured film, indentation hardness is measured at a strain rate of 0.05 / s using a nanoindenter (Nano Indenter G200 manufactured by Agilent Technologies, Inc., using a Berkovich indenter) at 23° C. The indentation elastic modulus is calculated by averaging the modulus values ​​at indentation depths of 500 nm to 800 nm.

[0028] (Ratio of Sum of Peak Heights of Cage Silsesquioxane Derivatives to Sum of All Peak Heights by MALDI TOF-MS) In terms of flex resistance and surface hardness, the hard coat composition according to the present disclosure is such that, in matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI TOF-MS), the sum of the peak heights of the cage silsesquioxane derivative having 8 silicon atoms, the cage silsesquioxane derivative having 10 silicon atoms, and the cage silsesquioxane derivative having 12 silicon atoms, which are shown in the region of a molecular weight of 4,000 or less, is preferably less than 18%, more preferably 10% or less, even more preferably 5% or less, and particularly preferably 0%, of the sum of all peak heights. Examples of the cage silsesquioxane derivative (T8) having 8 silicon atoms, the cage silsesquioxane derivative (T10) having 10 silicon atoms, and the cage silsesquioxane derivative (T12) having 12 silicon atoms are shown below, where R represents an organic group on the silicon atom.

[0029]

[0030]

[0031]

[0032] In matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI TOF-MS), the method for measuring the ratio of the sum of peak heights of a cage silsesquioxane derivative having 8 silicon atoms, a cage silsesquioxane derivative having 10 silicon atoms, and a cage silsesquioxane derivative having 12 silicon atoms, which are shown in the region of molecular weight of 4,000 or less, to the sum of all peak heights, is as follows. All peak heights obtained by the measurement were measured, and the ratio was calculated using the following formula to obtain the ratio of the sum of peak heights of the cage silsesquioxane derivatives. Ratio (%) of the sum of peak heights of cage silsesquioxane derivatives = ((sum of peak heights attributed to cage silsesquioxanes) / (sum of all peak heights)) x 100

[0033] Furthermore, it is preferable that a 10 μm-thick hard coat obtained by curing the hard coat composition on a substrate does not break even when bent outward 50,000 times continuously at a bending radius R of 5 mm. Specifically, a 10 μm-thick hard coat is prepared by curing the hard coat composition on a substrate, and the substrate is set with the hard coat surface facing outward in a durability tester DMLHP-CS manufactured by Yuasa System Equipment Co., Ltd., and a repeated bending test is performed 50,000 times at a bending radius R of 5.0 mm at a rate of 1 bending / 2 seconds, and the hard coat is visually inspected for cracks. The repeated bending test is performed in a constant temperature and humidity environment set at a temperature of 23°C and a humidity of 50% RH.

[0034] (Silsesquioxane Derivative Represented by Formula (1)) The hard coat composition according to the present disclosure contains the silsesquioxane derivative represented by formula (1).

[0035] The structural units that the silsesquioxane derivative used in the present disclosure may contain are referred to as structural units (a) to (g) below.

[0036]

[0037] In the silsesquioxane derivative represented by formula (1), t, u, v, w, x, y, and z are each independently 0 or a positive number, and at least one of u and v is a positive number. In other words, the silsesquioxane derivative of the present disclosure includes at least one of the structural units (b) and (c) among the structural units (a) to (g) described above, and may optionally include at least one of the structural units (a), (d), (e), (f), and (g).

[0038] In formula (1), t, u, v, w, x, y, and z represent the molar ratios of the structural units (a) to (g). In formula (1), t, u, v, w, x, y, and z represent the relative molar ratios of the structural units (a) to (g) that may be contained in the silsesquioxane derivative represented by formula (1). The molar ratio can be determined, for example, from the NMR (nuclear magnetic resonance) analysis value of the silsesquioxane derivative of the present disclosure. Furthermore, when the reaction rate of each raw material for the silsesquioxane derivative is known, or when the yield is 100%, the molar ratio can be determined from the amount of the raw material charged. For example, the molar ratio of each structural unit of the silsesquioxane derivative can be determined by analyzing the molar ratio of a sample dissolved in deuterated chloroform or the like. １ H-NMR analysis is carried out, and further analysis is carried out as necessary. ２９ The calculation may also be performed by Si-NMR analysis. The original structure of the silsesquioxane derivative may be estimated from the ratio of the constituent units after decomposing the silsesquioxane derivative into constituent units with an alkali or the like. If necessary, the molar ratio of each constituent unit of the silsesquioxane derivative may be determined by combining known techniques such as mass spectrometry and IR (infrared absorption spectroscopy) analysis.

[0039] Each of the structural units (b) to (g) in formula (1) may be of only one type, or may be of two or more types. Furthermore, the order of arrangement in formula (1) indicates the composition of the structural units, but does not refer to the order of arrangement of the silsesquioxane derivative. Therefore, the condensation form of the structural units in the silsesquioxane derivative of the present disclosure does not necessarily have to be the same as the order of arrangement in formula (1). Details of the structural units (a) to (g) are described below.

[0040] (Structural Unit (a)) The structural unit (a) is a unit in which O is bonded to one silicon atom. １／２ The Q unit has four silicon atoms (two oxygen atoms). １／２ It means a unit having four of these.

[0041] The proportion of the structural unit (a) in the silsesquioxane derivative represented by formula (1) is not particularly limited. For example, the molar ratio of the structural unit (a) to all structural units (t / (t+u+v+w+x+y+z)) is preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0, from the viewpoint of the viscosity of the silsesquioxane derivative and the hardness of the cured product. Here, a molar ratio of 0 means that the corresponding structural unit is not contained, and the same applies hereinafter.

[0042] (Structural Unit (b)) The structural unit (b) is a unit in which O is substituted with 1 silicon atom. １／２ Three oxygen atoms (1.5 oxygen atoms), R １ The T unit is a T unit in which an acryloyloxy group is bonded to a silicon atom via O. １／２ It means a unit having three of these.

[0043] In the structural unit (b), R １ is an alkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 3 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, or an aralkylene group having 7 to 12 carbon atoms. １ is preferably an alkylene group having 1 to 10 carbon atoms or a cycloalkylene group having 3 to 10 carbon atoms, and more preferably an alkylene group having 1 to 10 carbon atoms.

[0044] The alkylene group having 1 to 10 carbon atoms is preferably an alkylene group having 1 to 6 carbon atoms, more preferably an alkylene group having 2 to 4 carbon atoms, and even more preferably a propylene group. The alkylene group having 1 to 10 carbon atoms may be linear or branched. The cycloalkylene group having 3 to 10 carbon atoms is preferably a cycloalkylene group having 3 to 6 carbon atoms, and more preferably a cycloalkylene group having 4 to 6 carbon atoms. The cycloalkylene group having 3 to 10 carbon atoms may be branched.

[0045] The proportion of the structural unit (b) in the silsesquioxane derivative represented by formula (1) is not particularly limited. For example, the molar ratio (u / (t+u+v+w+x+y+z)) of the structural unit (b) to all structural units is preferably 0.2 to 0.99, more preferably 0.3 to 0.9, even more preferably 0.3 to 0.7, and particularly preferably 0.45 to 0.65, from the viewpoints of cure shrinkage, hardness, storage stability, and curability with active energy rays such as UV. The molar ratio of the structural unit (b) to all structural units may be 0.

[0046] Furthermore, from the viewpoints of cure shrinkage, hardness, storage stability, and curability with active energy rays such as UV, it is preferable that u > v be satisfied, it is more preferable that the molar ratio of structural unit (b) (u / (t + u + v + w + x + y + z)) > the molar ratio of structural unit (c) (v / (t + u + v + w + x + y + z)) + 0.05 be satisfied, and it is particularly preferable that the molar ratio of structural unit (b) (u / (t + u + v + w + x + y + z)) > the molar ratio of structural unit (c) (v / (t + u + v + w + x + y + z)) + 0.10 be satisfied.

[0047] (Structural Unit (c)) The structural unit (c) is a unit in which O is bonded to one silicon atom. １／２ Three oxygen atoms (1.5 oxygen atoms), R ２ The hydrogen atom is connected to R ３ The T unit is a T unit in which an acryloyloxy group (such as a methacryloyloxy group) substituted with the above is bonded to a silicon atom.

[0048] In the structural unit (c), R ２is an alkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 3 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, or an aralkylene group having 7 to 12 carbon atoms. ２ A preferred embodiment of the present invention is R １ is the same as:

[0049] In the structural unit (c), R ３ is an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group, with a methyl group and an ethyl group being preferred, and a methyl group being more preferred.

[0050] The proportion of the structural unit (c) in the silsesquioxane derivative represented by formula (1) is not particularly limited. For example, the molar ratio (v / (t+u+v+w+x+y+z)) of the structural unit (c) to all structural units is preferably 0 to 0.8, more preferably 0.05 to 0.7, even more preferably 0.2 to 0.7, and particularly preferably 0.35 to 0.55, from the viewpoints of cure shrinkage, hardness, storage stability, and curability with active energy rays such as UV. The molar ratio of the structural unit (c) to all structural units may be 0.

[0051] In formula (1), at least one of u and v is a positive number, and from the viewpoint of hardness of the cured product, it is preferred that u and v are each independently a positive number.

[0052] The total molar ratio ((u+v) / (t+u+v+w+x+y+z)) of the structural units (b) and (c) to all structural units is, from the standpoints of cure shrinkage, hardness, storage stability, UV or other active energy ray curability, and viscosity, preferably from 0.3 to 1, more preferably from 0.5 to 1, even more preferably from 0.7 to 1, and particularly preferably from 0.9 to 1.

[0053] (Structural Unit (d)) The structural unit (d) is a unit in which O is bonded to one silicon atom. １／２ Three oxygen atoms (1.5 oxygen atoms), R ４ is a T unit bonded to the silicon atom.

[0054] In the structural unit (d), R ４ is a hydrogen atom, a saturated or unsaturated chain hydrocarbon group having 1 to 20 carbon atoms, a saturated or unsaturated cyclic hydrocarbon group having 3 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms.

[0055] The saturated or unsaturated chain hydrocarbon group having 1 to 20 carbon atoms may be linear or branched. The saturated or unsaturated chain hydrocarbon group having 1 to 20 carbon atoms is preferably a saturated or unsaturated chain hydrocarbon group having 1 to 10 carbon atoms, and more preferably a saturated chain hydrocarbon group having 1 to 10 carbon atoms.

[0056] Examples of saturated chain hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups. From the viewpoints of heat resistance and hardness of the cured product, methyl or ethyl groups are preferred, and methyl groups are more preferred.

[0057] Examples of the unsaturated chain hydrocarbon group having 1 to 10 carbon atoms include a vinyl group, a 2-propenyl group, and an ethynyl group.

[0058] The saturated or unsaturated cyclic hydrocarbon group having 3 to 8 carbon atoms may be branched. The saturated or unsaturated cyclic hydrocarbon group having 3 to 8 carbon atoms is preferably a saturated or unsaturated cyclic hydrocarbon group having 4 to 6 carbon atoms.

[0059] The aryl group having 6 to 20 carbon atoms is preferably an aryl group having 6 to 10 carbon atoms.

[0060] Examples of the aryl group having 6 to 20 carbon atoms include a phenyl group, a group in which one or more hydrogen atoms of a phenyl group are substituted with an alkyl group having 1 to 10 carbon atoms, and a naphthyl group. From the viewpoints of heat resistance and hardness of the cured product, a phenyl group is preferred.

[0061] The aralkyl group having 7 to 20 carbon atoms is preferably an aralkyl group having 7 to 10 carbon atoms.

[0062] Examples of aralkyl groups having 7 to 20 carbon atoms include groups in which one hydrogen atom of an alkyl group having 1 to 10 carbon atoms is substituted with an aryl group such as a phenyl group. Examples include benzyl groups and phenethyl groups, with benzyl groups being preferred from the viewpoints of heat resistance and hardness of the cured product.

[0063] R ４ When a part of the structure represented by the formula (I) is substituted with a substituent or a halogen atom, R ４ Examples of the alkyl group include a 3-glycidoxypropyl group, a 2-(3,4-epoxycyclohexyl)ethyl group, a 3-(3-ethyloxetan-3-yl)methoxypropyl group, a 3-hydroxypropyl group, a 3-aminopropyl group, a 3-dimethylaminopropyl group, a 3-hydroxypropyl group, a 3-aminopropyl hydrochloride salt, a 3-dimethylaminopropyl hydrochloride salt, a p-styryl group, an N-2-(aminoethyl)-3-aminopropyl group, an N-phenyl-3-aminopropyl group, an N-(vinylbenzyl)-2-aminoethyl-3-aminopropyl hydrochloride salt, a 3-ureidopropyl group, a 3-mercaptopropyl group, a 3-isocyanatopropyl group, a 3-carboxypropyl group, and a 3-chloropropyl group.

[0064] The proportion of the structural unit (d) in the silsesquioxane derivative represented by formula (1) is not particularly limited. For example, the molar ratio of the structural unit (d) to all structural units (w / (t+u+v+w+x+y+z)) is preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0, from the viewpoint of hardness when cured.

[0065] (Structural Unit (e)) The structural unit (e) is a unit in which O is bonded to one silicon atom. １／２ (one as an oxygen atom) and two R ５ is a D unit in which O is bonded to a silicon atom. １／２ It means a unit having two of these.

[0066] In the structural unit (e), R ５is a hydrogen atom, a saturated or unsaturated chain hydrocarbon group having 1 to 20 carbon atoms, a saturated or unsaturated cyclic hydrocarbon group having 3 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. ５ may be the same or different. ５ A preferred embodiment of the present invention is R ４ is the same as:

[0067] The proportion of the structural unit (e) in the silsesquioxane derivative represented by formula (1) is not particularly limited. For example, the molar ratio (x / (t+u+v+w+x+y+z)) of the structural unit (e) to all structural units is preferably 0.1 or less, more preferably 0.05 or less, more preferably 0.025 or less, more preferably 0.005 or less, and even more preferably 0, from the viewpoint of hardness when cured. On the other hand, from the viewpoint of cure shrinkage and flex resistance, x is preferably a positive number, and the molar ratio (x / (t+u+v+w+x+y+z)) of the structural unit (e) to all structural units is more preferably 0.005 or more, and even more preferably 0.025 or more.

[0068] (Structural Unit (f)) The structural unit (f) is a unit in which O is bonded to one silicon atom. １／２ (0.5 oxygen atoms), and one R ６ and two R ５ is an M unit in which O is bonded to a silicon atom. １／２ It means a unit having one

[0069] In the structural unit (f), R ６ is an organic group having 2 to 12 carbon atoms and at least one of an ethylenically unsaturated bond and a carbon-carbon triple bond.

[0070] Examples of the organic group having 2 to 12 carbon atoms and an ethylenically unsaturated bond include a vinyl group, an orthostyryl group, a metastyryl group, a parastyryl group, an acryloyloxymethyl group, a methacryloyloxymethyl group, a 2-acryloyloxyethyl group, a 2-methacryloyloxyethyl group, a 3-acryloyloxypropyl group, a 3-methacryloyloxypropyl group, an 8-acryloyloxyoctyl group, and an 8-methacryloyloxyoctyl group.

[0033] Examples of suitable styrene groups include vinyl, 1-propenyl, 2-propenyl, 1-methylethenyl, 1-butenyl, 3-butenyl, 1-pentenyl, 4-pentenyl, 3-methyl-1-butenyl, 1-phenylethenyl, 2-phenylethenyl, ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 3-butynyl, 1-pentynyl, 4-pentynyl, 3-methyl-1-butynyl, and phenylbutynyl. From the viewpoint of hardness of the cured product, vinyl, 2-propenyl, orthostyryl, metastyryl, and parastyryl groups are preferred, and vinyl is more preferred.

[0071] In the structural unit (f), R ７ is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. ７ may be the same or different from each other.

[0072] Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. From the viewpoints of heat resistance and hardness of the cured product, a methyl group or an ethyl group is preferred, and a methyl group is more preferred.

[0073] Examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, a group in which one or more hydrogen atoms of a phenyl group are substituted with an alkyl group having 1 to 4 carbon atoms, and a naphthyl group. From the viewpoints of heat resistance and hardness of the cured product, a phenyl group is preferred.

[0074] Examples of aralkyl groups having 7 to 10 carbon atoms include groups in which one hydrogen atom of an alkyl group having 1 to 4 carbon atoms is substituted with an aryl group such as a phenyl group. Examples include benzyl and phenethyl groups, with benzyl groups being preferred from the viewpoints of heat resistance and hardness of the cured product.

[0075] The proportion of the structural unit (f) in the silsesquioxane derivative represented by formula (1) is not particularly limited. For example, the molar ratio of the structural unit (f) to all structural units (y / (t+u+v+w+x+y+z)) is preferably 0.5 or less, more preferably 0.3 or less, and even more preferably 0.1 or less, from the viewpoints of cure shrinkage, hardness, storage stability, and curability with active energy rays such as UV. The molar ratio of the structural unit (f) to all structural units (y / (t+u+v+w+x+y+z)) may be 0 or may be 0.001 or more.

[0076] (Structural Unit (g)) The structural unit (g) is a unit in which O is bonded to one silicon atom. １／２ (0.5 oxygen atoms), and three R ８ is the M unit bonded to the silicon atom.

[0077] In the structural unit (g), R ８ is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms. ８ may be the same or different. ８ A preferred embodiment of the present invention is R ７ is the same as:

[0078] The proportion of the structural unit (g) in the silsesquioxane derivative represented by formula (1) is not particularly limited. For example, the molar ratio of the structural unit (g) to all structural units (z / (t+u+v+w+x+y+z)) is preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0, from the viewpoint of hardness when cured.

[0079] (Other structural units (h)) The silsesquioxane derivative represented by formula (1) may further contain (R ９ O １／２ ) (hereinafter, also referred to as structural unit (h)). ９ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. The alkyl group having 1 to 6 carbon atoms may be either an aliphatic group or an alicyclic group, and may be either linear or branched. Specific examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.

[0080] The structural unit (h) is an alkoxy group, which is a hydrolyzable group contained in the silicon compound described below, or an alkoxy group generated by substitution of the hydrolyzable group of the silicon compound with an alcohol contained in the reaction solvent, and may be one that remains in the molecule without being hydrolyzed or polycondensed, or may be a hydroxyl group that remains in the molecule after hydrolysis without being polycondensed.

[0081] In formula (1), from the viewpoints of cure shrinkage, hardness, storage stability, and curability with active energy rays such as UV, it is preferable that t, x, and z are 0 and w and y are each independently 0 or a positive number, and it is more preferable that t, w, x, y, and z are 0. Furthermore, in formula (1), from the viewpoints of cure shrinkage, hardness, storage stability, and curability with active energy rays such as UV, it is preferable that 0≦y / (u+v+w)≦0.5 is satisfied, it is more preferable that 0≦y / (u+v+w)≦0.3 is satisfied, and it is even more preferable that 0≦y / (u+v+w)≦0.1 is satisfied.

[0082] Alternatively, in formula (1), from the viewpoints of cure shrinkage, hardness, storage stability, and curability with active energy rays such as UV, it is preferable that t, y, and z are 0, and w and x are each independently 0 or a positive number. Furthermore, in formula (1), from the viewpoints of cure shrinkage, hardness, storage stability, and curability with active energy rays such as UV, it is preferable that 0≦x / (u+v+w)≦0.5 is satisfied, more preferably 0≦x / (u+v+w)≦0.3 is satisfied, and even more preferably 0≦x / (u+v+w)≦0.1 is satisfied.

[0083] In formula (1), from the viewpoints of cure shrinkage, hardness, storage stability, and UV curability, u and v are preferably each independently a positive number. Furthermore, from the viewpoints of cure shrinkage, hardness, storage stability, and UV or other active energy ray curability, u and v preferably satisfy 0<v / u≦1, more preferably 0.1≦v / u≦1, even more preferably 0.2≦v / u≦1, and particularly preferably 0.3≦v / u≦1.

[0084] (Weight-Average Molecular Weight of Silsesquioxane Derivative) The weight-average molecular weight (hereinafter also referred to as "Mw") of the silsesquioxane derivative represented by formula (1) is not particularly limited, and may be, for example, 300 to 30,000, 500 to 15,000, 700 to 10,000, or 1,000 to 5,000. Note that Mw in the present disclosure refers to the value obtained by converting the molecular weight measured by GPC (gel permeation chromatography) using polystyrene as a standard substance. The measurement conditions for Mw can be, for example, the measurement conditions in the Examples described below.

[0085] (Viscosity of Silsesquioxane Derivative) In the silsesquioxane derivative represented by formula (1), the viscosity at 25°C is preferably 10 mPa·s to 50,000 mPa·s, more preferably 100 mPa·s to 40,000 mPa·s, even more preferably 1,000 mPa·s to 30,000 mPa·s, and particularly preferably 2,000 mPa·s to 20,000 mPa·s. In the present disclosure, the viscosity at 25°C refers to a value measured using an E-type viscometer (a cone-plate viscometer, for example, a TVE22H viscometer manufactured by Toki Sangyo Co., Ltd.).

[0086] (Method for Producing Silsesquioxane Derivative) The silsesquioxane derivative represented by formula (1) can be produced by a known method. The method for producing a silsesquioxane derivative is disclosed in detail in WO 2013 / 031798 and the like as a method for producing polysiloxane.

[0087] Among them, the method for producing the silsesquioxane derivative represented by formula (1) is ｎ Six ｐ (n represents an integer of 0 to 3, p represents an integer of 1 to 4, n+p=4, R represents a group bonded to a silicon atom in the silsesquioxane derivative via a carbon atom, and X represents a hydrolyzable group), using an organic solvent and adding 1.5 molar equivalents or more of water relative to the total amount of hydrolyzable groups possessed by the organosilicon compound (hereinafter also referred to as the "hydrolysis step"). R is preferably a group (H ２ C=CHCOO-R １ -, H ２ C=C(R ３ ) COO-R ２ - and R ４ ~R ８ X is preferably an alkoxy group, a silyloxy group, or a halogen atom, and more preferably an alkoxy group or a silyloxy group.

[0088] In the hydrolysis step, it is preferable to carry out not only the hydrolysis of the organosilicon compound but also the hydrolysis and polycondensation reaction of the organosilicon compound and, if necessary, other silicon compounds. Also, in the hydrolysis step, the hydrolysis and polycondensation reaction of the organosilicon compound and, if necessary, other silicon compounds is carried out to obtain a silsesquioxane derivative as an intermediate product, and then the obtained intermediate product may be further subjected to hydrolysis and polycondensation reaction with the organosilicon compound or the like.

[0089] When obtaining an intermediate product as described above, after carrying out hydrolysis and polycondensation reactions of the organosilicon compound and, if necessary, other silicon compounds, the obtained intermediate product may be further subjected to hydrolysis and polycondensation reactions of the organosilicon compound in which n is 3 and p is 1. This makes it possible to suitably synthesize a silsesquioxane derivative whose terminal portions are blocked with structural unit (f) derived from the organosilicon compound in which n is 3 and p is 1, thereby suppressing an increase in viscosity of the silsesquioxane derivative and improving its storage stability.

[0090] The method for producing the silsesquioxane derivative represented by formula (1) preferably includes a distillation step in which a silicon compound is subjected to hydrolysis and polycondensation reaction in the presence of a reaction solvent, and then the reaction solvent, by-products, residual monomers, water, and the like are distilled off from the reaction solution.

[0091] Among the organosilicon compounds, those having an acryloyl group include, for example, (3-acryloyloxypropyl)trimethoxysilane, (3-acryloyloxypropyl)triethoxysilane, (8-acryloyloxyoctyl)trimethoxysilane, and (3-acryloyloxypropyl)trichlorosilane.

[0092] Among the organosilicon compounds, those having a methacryloyl group include, for example, (3-methacryloyloxypropyl)trimethoxysilane, (3-methacryloyloxypropyl)triethoxysilane, (8-methacryloyloxyoctyl)trimethoxysilane, and (3-methacryloyloxypropyl)trichlorosilane.

[0093] Examples of organosilicon compounds that provide two structural units (f) upon hydrolysis include 1,3-divinyltetramethyldisiloxane, 1,3-bis(p-styryl)tetramethyldisiloxane, 1,3-bis(3-acryloyloxypropyl)tetramethyldisiloxane, 1,3-bis(3-methacryloyloxypropyl)tetramethyldisiloxane, as well as methoxydimethylvinylsilane, ethoxydimethylvinylsilane, chlorodimethylvinylsilane, dimethylvinylsilanol, (3-acryloyloxypropyl)dimethylmethoxysilane, (3-methacryloyloxypropyl)dimethylmethoxysilane, p-styryldimethylmethoxysilane, and ethynyldimethylmethoxysilane.

[0094] Examples of silicon compounds that give the structural unit (a) upon hydrolysis include tetramethoxysilane and tetraethoxysilane.

[0095] Examples of the organosilicon compound in which n is 3 and p is 1 include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, octyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, benzyltrimethoxysilane, cyclohexyltrimethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, p-styryltrimethoxysilane, ethynyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, ... trimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-isocyanatepropyltriethoxysilane, tris(trimethoxysilylpropyl)isocyanurate, 3-mercaptopropyltrimethoxysilane, 3-ethyl-3-[{3-(trimethoxysilyl)propoxy}methyl]oxetane, and 3-ethyl-3-[{3-(triethoxysilyl)propoxy}methyl]oxetane.

[0096] Examples of the organosilicon compound in which n is 2 and p is 2 include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldidiethoxysilane, propylmethyldimethoxysilane, octylmethyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, benzylmethyldimethoxysilane, cyclohexylmethyldimethoxysilane, vinylmethyldimethoxysilane, allylmethyldimethoxysilane, p-styrylmethyldimethoxysilane, ethynylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane, silane, 3-glycidoxypropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropylmethyldimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropylmethyldimethoxysilane hydrochloride, 3-ureidopropylmethyldialkoxysilane, 3-isocyanatopropylmethyldiethoxysilane, (3-acryloxypropyl)methyldimethoxysilane, and (3-methacryloxypropyl)methyldiethoxysilane.

[0097] Examples of the organosilicon compound in which n is 1 and p is 3 include hexamethyldisiloxane, trimethylmethoxysilane, trimethylethoxysilane, trimethylchlorosilane, and dimethylphenylmethoxysilane.

[0098] In the hydrolysis step, the reaction solvent is not particularly limited, but it is preferable to use an alcohol as the organic solvent. The alcohol is an alcohol in the narrow sense, represented by the general formula R—OH, and is a compound having no functional groups other than an alcoholic hydroxyl group. The alcohol is not particularly limited, and examples thereof include methanol, ethanol, 1-propanol, 2-propanol, 2-butanol, 2-pentanol, 3-pentanol, 2-methyl-2-butanol, 3-methyl-2-butanol, cyclopentanol, 2-hexanol, 3-hexanol, 2-methyl-2-pentanol, 3-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-3-pentanol, 2-ethyl-2-butanol, 2,3-dimethyl-2-butanol, and cyclohexanol. Among these, secondary alcohols such as 2-propanol, 2-butanol, 2-pentanol, 3-pentanol, 3-methyl-2-butanol, cyclopentanol, 2-hexanol, 3-hexanol, 3-methyl-2-pentanol, and cyclohexanol are preferred. In the hydrolysis step, these alcohols may be used alone or in combination.

[0099] The organic solvent used in the hydrolysis step may be alcohol alone, or may be a mixed solvent with at least one auxiliary solvent. The auxiliary solvent may be either a polar solvent or a non-polar solvent, or a combination of both. Examples of organic solvents other than alcohol include xylene, toluene, methyl ethyl ketone, methyl isobutyl ketone, and propylene glycol monomethyl ether.

[0100] The hydrolysis and condensation reactions in the hydrolysis step proceed in the presence of water. In the hydrolysis step, it is preferable to add 1.5 to 30 molar equivalents of water relative to the total amount of hydrolyzable groups possessed by the organosilicon compound to carry out hydrolysis and further condensation. Furthermore, in terms of the cure shrinkage, hardness, storage stability, and curl suppression properties during curing of the resulting silsesquioxane derivative, the amount of water added in the hydrolysis step is preferably 1.2 molar equivalents or more relative to the total amount of hydrolyzable groups possessed by the organosilicon compound, more preferably 1.5 molar equivalents or more, even more preferably 2.0 to 8 molar equivalents, particularly preferably 2.2 to 7 molar equivalents, and most preferably 2.4 to 6 molar equivalents.

[0101] The hydrolysis and polycondensation reaction of the silicon compound may be carried out without a catalyst or may be carried out using a catalyst. When a catalyst is used, acid catalysts exemplified by inorganic acids such as sulfuric acid, nitric acid, hydrochloric acid, and phosphoric acid; organic acids such as formic acid, acetic acid, oxalic acid, and paratoluenesulfonic acid; and base catalysts such as ammonia, tetramethylammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate are preferably used, with acid catalysts being more preferred. The amount of catalyst used is preferably an amount corresponding to 0.01 mol% to 20 mol%, more preferably an amount corresponding to 0.1 mol% to 10 mol%, relative to the total amount (mol) of silicon atoms contained in the silicon compound.

[0102] The completion of the hydrolysis and polycondensation reaction in the hydrolysis step can be appropriately detected by methods described in various publications, etc. In the hydrolysis step of the method for producing a silsesquioxane derivative according to the present disclosure, an auxiliary agent can be added to the reaction system.

[0103] By providing the above-described evaporation step after the hydrolysis step in the production of the silsesquioxane derivative represented by formula (1), the stability of the resulting silsesquioxane derivative of the present disclosure can be improved. The evaporation step can be carried out under normal pressure or reduced pressure, at room temperature or under heating, or under cooling.

[0104] The method for producing a silsesquioxane derivative may include a neutralization step of neutralizing the catalyst before the distillation step, and may also include a step of removing salts produced by neutralization by washing with water or the like.

[0105] Furthermore, the silsesquioxane derivative represented by formula (1) may contain a side-chain functional group derived from the silicon compound used as a raw material in the production, which is a group formed by ring-opening by the addition of an acid or the like to an oxetanyl group or an epoxy group, or may contain a hydroxyalkyl group formed by decomposition of an organic group having a (meth)acryloyl group, or a group formed by the addition of an acid or the like to an unsaturated hydrocarbon group. Specific examples include those in which a structure represented by formula (A) and / or a structure represented by formula (B) below is included as part of formula (1). The content ratio of the oxetanyl group or epoxy group-containing organic group, the (meth)acryloyl group-containing organic group, or the unsaturated hydrocarbon group-containing organic group derived from the silicon compound as a raw material is 50 mol% or less, which is sufficient for implementing the present disclosure, and is preferably 30 mol% or less, and more preferably 10 mol% or less. In both formulas (A) and (B), T units are exemplified, but similar D units, M units, etc. may also be used.

[0106]

[0107]

[0108] (Polymerization initiator) The hard coat composition according to the present disclosure preferably further contains a polymerization initiator. The polymerization initiator is not particularly limited, and examples thereof include a photopolymerization initiator and a thermal polymerization initiator. Examples of the photopolymerization initiator include a photoradical polymerization initiator. Examples of the thermal polymerization initiator include a thermal radical polymerization initiator. Known compounds may be used as the photopolymerization initiator and the thermal polymerization initiator.

[0109] Examples of photoradical polymerization initiators include 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, and diethoxy Acetophenone compounds such as acetophenone, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone] and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)benzyl]phenyl}-2-methyl-propan-1-one; benzophenone compounds such as benzophenone, 4-phenylbenzophenone, 2,4,6-trimethylbenzophenone and 4-benzoyl-4'-methyldiphenyl sulfide; methylbenzoyl formate, oxyphenyl acetate α-ketoester compounds such as 2-[2-oxo-2-phenylacetoxyethoxy]ethyl ester of oxyphenylacetic acid and 2-[2-hydroxyethoxy]ethyl ester of oxyphenylacetic acid; phosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide; benzoin, benzoin methyl ether, benzoin benzoin-based compounds such as benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; titanocene-based compounds; acetophenone / benzophenone hybrid photoinitiators such as 1-(4-(4-benzoylphenylsulfanyl)phenyl)-2-methyl-2-(4-methylphenylsulfinyl)propan-1-one; oxime ester photopolymerization initiators such as 1-(4-phenylthiophenyl)-2-(O-benzoyloxime)-1,2-octanedione; and camphorquinone. These may be used alone or in combination of two or more.

[0110] There are no particular limitations on the thermal radical polymerization initiator, and examples thereof include peroxides and azo-based initiators.

[0111] Examples of peroxides include hydrogen peroxide; inorganic peroxides such as sodium persulfate, ammonium persulfate, and potassium persulfate; 1,1-bis(t-butylperoxy)2-methylcyclohexane, 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, and 2,2-bis(4,4-dimethylcyclohexane). -butylperoxycyclohexyl)propane, 1,1-bis(t-butylperoxy)cyclododecane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di(m-toluoylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t- Hexyl peroxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butyl peroxyacetate, 2,2-bis(t-butylperoxy)butane, t-butyl peroxybenzoate, n-butyl-4,4-bis(t-butylperoxy)valerate, di-t-butylperoxyisophthalate, α,α'-bis(t-butylperoxy)diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane Examples of the organic peroxide include dimethylsilyl peroxide, t-butyl cumyl peroxide, di-t-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, diisopropylbenzene hydroperoxide, t-butyltrimethylsilyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, and t-butyl hydroperoxide. These peroxides may be used alone or in combination of two or more.

[0112] Examples of azo initiators include azo compounds such as 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2-(carbamoylazo)isobutyronitrile, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, azodi-t-octane, and azodi-t-butane. These may be used alone or in combination of two or more. A redox reaction can also be carried out by combining a peroxide with a redox polymerization initiation system that uses a reducing agent such as ascorbic acid, sodium ascorbate, sodium erythorbate, tartaric acid, citric acid, a metal salt of formaldehyde sulfoxylate, sodium thiosulfate, sodium sulfite, sodium bisulfite, sodium metabisulfite, or ferric chloride.

[0113] The content of the polymerization initiator in the composition for hard coat according to the present disclosure is preferably 0.01 parts by mass to 20 parts by mass, more preferably 0.1 parts by mass to 10 parts by mass, and even more preferably 1 part by mass to 5 parts by mass, relative to 100 parts by mass of the silsesquioxane derivative represented by formula (1).

[0114] (Other Components) The hard coat composition according to the present disclosure may further contain other components in addition to the silsesquioxane derivative represented by formula (1) and the polymerization initiator. The other components are not particularly limited, and examples thereof include solvents, polymerizable compounds other than the silsesquioxane derivative represented by formula (1), resins, silicones, monomers, fillers, surfactants, antistatic agents (e.g., conductive polymers), leveling agents, photosensitizers, UV absorbers, antioxidants, heat resistance improvers, stabilizers, lubricants, pigments, dyes, plasticizers, suspending agents, adhesion promoters, nanoparticles, nanofibers, nanosheets, etc. The hard coat composition according to the present disclosure may also contain silane-based reactive diluents such as tetraalkoxysilanes, trialkoxysilanes, dialkoxysilanes, monoalkoxysilanes, and disiloxanes.

[0115] The hard coat composition according to the present disclosure may or may not contain a solvent. Examples of the solvent include various organic solvents such as aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, chlorinated hydrocarbon solvents, alcohol solvents, ether solvents, amide solvents, ketone solvents, ester solvents, and cellosolve solvents.

[0116] The hard coat composition according to the present disclosure may or may not contain a polymerizable compound other than the silsesquioxane derivative represented by formula (1) (hereinafter also referred to as "other polymerizable compounds"). The other polymerizable compound is not particularly limited as long as it is a compound capable of undergoing a polymerization reaction in the presence of the silsesquioxane derivative represented by formula (1) and a polymerization initiator. Examples of the other polymerizable compound include silsesquioxane derivatives other than the silsesquioxane derivative represented by formula (1), (meth)acrylate compounds, compounds having an ethylenically unsaturated group, epoxy compounds (compounds having an epoxy group), compounds having an oxetanyl group (oxetanyl group-containing compounds), and compounds having a vinyl ether group (vinyl ether compounds).

[0117] Examples of silsesquioxane derivatives other than the silsesquioxane derivative represented by formula (1) include silsesquioxane derivatives consisting of only T units, and silsesquioxane derivatives containing T units and D units.

[0118] The (meth)acrylate compound is not particularly limited, and examples thereof include a compound having one (meth)acryloyl group (hereinafter also referred to as a "monofunctional (meth)acrylate") and a compound having two or more (meth)acryloyl groups (hereinafter also referred to as a "polyfunctional (meth)acrylate").

[0119] Examples of the monofunctional (meth)acrylate include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate; monofunctional (meth)acrylates having an alicyclic group such as cyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and tricyclodecanemethylol (meth)acrylate; monofunctional (meth)acrylates having an aromatic group such as benzyl (meth)acrylate and phenyl (meth)acrylate; (Meth)acrylates of alkylene oxide adducts of phenol derivatives such as (meth)acrylate of phenol ethylene oxide adduct, (meth)acrylate of phenol propylene oxide adduct, (meth)acrylate of modified nonylphenol ethylene oxide adduct, (meth)acrylate of nonylphenol propylene oxide adduct, (meth)acrylate of alkylene oxide adduct of para-cumylphenol, orthophenylphenol (meth)acrylate, and (meth)acrylate of alkylene oxide adduct of orthophenylphenol; monofunctional (meth)acrylates having an alkoxyalkyl group such as 2-ethylhexyl carbitol (meth)acrylate; monofunctional (meth)acrylates having a heterocycle such as tetrahydrofurfuryl (meth)acrylate and N-(2-(meth)acryloxyethyl)hexahydrophthalimide; hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, Hydroxylalkyl (meth)acrylates such as hydroxybutyl (meth)acrylate and hydroxyhexyl (meth)acrylate; monofunctional (meth)acrylates having a hydroxyl group and an aromatic group such as 2-hydroxy-3-phenoxypropyl (meth)acrylate; alkylene glycol mono(meth)acrylates such as diethylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, and tripropylene glycol mono(meth)acrylate;and monofunctional (meth)acrylates having a carboxy group such as ω-carboxypolycaprolactone mono(meth)acrylate and monohydroxyethyl phthalate (meth)acrylate.

[0120] Examples of polyfunctional (meth)acrylates include polyethylene glycol di(meth)acrylates such as diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tetraethylene glycol di(meth)acrylate; polypropylene glycol di(meth)acrylates such as dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and tetrapropylene glycol di(meth)acrylate; Examples of the di(meth)acrylate include 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-modified neopentyl glycol di(meth)acrylate, ethylene oxide-modified bisphenol A di(meth)acrylate, propylene oxide-modified bisphenol A di(meth)acrylate, ethylene oxide-modified hydrogenated bisphenol A di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane allyl ether di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexaacrylate.

[0121] As the polyfunctional (meth)acrylate, a urethane (meth)acrylate can also be used. Examples of the urethane (meth)acrylate include a compound obtained by addition reaction of an organic polyisocyanate with a hydroxyl group-containing (meth)acrylate, and a compound obtained by addition reaction of an organic polyisocyanate with a polyol and a hydroxyl group-containing (meth)acrylate. The monofunctional (meth)acrylate, polyfunctional (meth)acrylate, etc. may be used alone or in combination of two or more types, or different types may be used in combination.

[0122] Here, examples of polyols include low-molecular-weight polyols, polyether polyols, polyester polyols, and polycarbonate polyols. Examples of low-molecular-weight polyols include ethylene glycol, propylene glycol, neopentyl glycol, cyclohexane dimethylol, and 3-methyl-1,5-pentanediol. Examples of polyether polyols include polypropylene glycol and polytetramethylene glycol. Examples of polyester polyols include reaction products of these low-molecular-weight polyols and / or polyether polyols with dibasic acids such as adipic acid, succinic acid, phthalic acid, hexahydrophthalic acid, and terephthalic acid, or acid components such as anhydrides thereof. These may be used alone or in combination of two or more types, or different types may be used in combination.

[0123] Examples of organic polyisocyanates include tolylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. Examples of hydroxyl group-containing (meth)acrylates include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; and hydroxyl group-containing polyfunctional (meth)acrylates such as pentaerythritol tri(meth)acrylate, di(meth)acrylate of an adduct of 3 moles of alkylene oxide with isocyanuric acid, and dipentaerythritol penta(meth)acrylate. These may be used alone or in combination of two or more, or different types may be used in combination.

[0124] In the hard coat composition according to the present disclosure, when a (meth)acrylate compound is used in combination, the blending ratio thereof is not particularly limited, and for example, the blending ratio of the (meth)acrylate compound relative to 100 parts by mass of the silsesquioxane derivative represented by the formula (1) is preferably 0 parts by mass to 100 parts by mass, more preferably 0 parts by mass to 50 parts by mass, and even more preferably 0 parts by mass to 20 parts by mass. From the viewpoint of adhesion to the inorganic substance layer, a low blending ratio of the (meth)acrylate compound is preferable, and it is preferable that the (meth)acrylate compound is not contained or its content is 10% by mass or less relative to the total amount of the composition, more preferably that the (meth)acrylate compound is not contained or its content is 5% by mass or less relative to the total amount of the composition, even more preferably that the (meth)acrylate compound is not contained or its content is 1% by mass or less relative to the total amount of the composition, and it is particularly preferable that the (meth)acrylate compound is not contained.

[0125] A compound having one ethylenically unsaturated group per molecule other than the (meth)acrylate compound may be added to the curable composition. The ethylenically unsaturated group is preferably a (meth)acryloyl group, a maleimide group, a (meth)acrylamide group, or a vinyl group. Specific examples of the compound having an ethylenically unsaturated group include (meth)acrylic acid, a Michael addition dimer of acrylic acid, N-(2-hydroxyethyl)citraconimide, N,N-dimethylacrylamide, acryloylmorpholine, N-vinylpyrrolidone, and N-vinylcaprolactam. These compounds may be used alone or in combination of two or more.

[0126] Examples of epoxy compounds include monofunctional epoxy compounds and polyfunctional epoxy compounds. Examples of oxetanyl group-containing compounds include monofunctional oxetane compounds and polyfunctional oxetane compounds. Examples of vinyl ether compounds include monofunctional vinyl ether compounds and polyfunctional vinyl ether compounds. For example, compounds described in JP 2011-42755 A may be used as these compounds. There are no particular limitations on the silicone, and known silicones can be used, such as polydimethylsilicone, polydiphenylsilicone, and polymethylphenylsilicone, with those having functional groups at their terminals and / or side chains being preferred. There are no particular limitations on the functional group, and examples include (meth)acryloyl groups, epoxy groups, oxetanyl groups, vinyl groups, hydroxyl groups, carboxy groups, amino groups, and thiol groups.

[0127] When the composition for hard coat according to the present disclosure contains other polymerizable compounds, the content of the other polymerizable compounds is preferably 0.01 parts by mass to 100 parts by mass, more preferably 0.1 parts by mass to 50 parts by mass, and even more preferably 1 part by mass to 25 parts by mass, relative to 100 parts by mass of the silsesquioxane derivative represented by formula (1).

[0128] (Method of Manufacturing Hard Coat Composition) The method of manufacturing the hard coat composition according to the present disclosure is not particularly limited, and a known method can be used. ｎSix ｐ (n represents an integer of 0 to 3, p represents an integer of 1 to 4, n+p=4, R represents a group bonded to a silicon atom in the silsesquioxane derivative via a carbon atom, and X represents a hydrolyzable group), using an organic solvent and adding 1.5 molar equivalents or more of water relative to the total amount of hydrolyzable groups possessed by the organosilicon compound. The hydrolysis step in the method for producing a hard coat composition according to the present disclosure is the same as the hydrolysis step in the method for producing a silsesquioxane derivative represented by formula (1), and preferred embodiments are also the same.

[0129] [Hard Coat] The hard coat according to the present disclosure is obtained by curing the composition for hard coat according to the present disclosure. For example, the hard coat according to the present disclosure can be obtained by irradiating the composition for hard coat according to the present disclosure with active energy rays or by heating the composition for hard coat according to the present disclosure.

[0130] The hard coat composition according to the present disclosure may be cured after the hard coat composition according to the present disclosure is applied to a substrate. The hard coat composition according to the present disclosure may or may not contain a solvent. When the hard coat composition according to the present disclosure contains a solvent, it is preferable to remove the solvent before curing.

[0131] When applying the hard coat composition according to the present disclosure to a substrate, the application method of the hard coat composition is not particularly limited. Examples of application methods include common coating methods such as casting, spin coating, bar coating, dip coating, spray coating, roll coating, flow coating, and gravure coating. The thickness of the hard coat composition according to the present disclosure is not particularly limited and can be appropriately set depending on the purpose. The substrate to which the hard coat composition according to the present disclosure is applied is not particularly limited, and examples thereof include wood, metal, inorganic materials, plastics, paper, fibers, and fabrics. Metals include copper, silver, iron, aluminum, silicon, silicon steel, and stainless steel. Inorganic materials include metal oxides such as aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide, zinc oxide, indium tin oxide, and gallium oxide; metal nitrides such as aluminum nitride, gallium nitride, and silicon nitride; ceramics such as silicon carbide and boron nitride; mortar, concrete, and glass. Specific examples of plastics include acrylic resins such as polymethyl methacrylate, polyester resins such as polyethylene terephthalate, polyvinyl chloride resins, polycarbonate resins, epoxy resins, polyamide resins such as nylon and aramid, fluororesins such as polyimide resins, polyamideimide resins, and tetrafluoroethylene resins, polyolefin resins such as cross-linked polyethylene resins, vinylidene chloride resins, acrylonitrile-butadiene-styrene (ABS) resins, polystyrene resins, polyacrylonitrile resins, cycloolefin polymers (COP), cycloolefin copolymers (COC), acetate resins, polyarylates, cellophane, norbornene resins, acetylcellulose resins such as triacetylcellulose (TAC), composite resins such as polychloroprene, polyphenylene sulfide, polysulfone, polyethersulfone, polyetheretherketone, polyurethane resins, and glass epoxy resins, and various fiber-reinforced resins. Examples of fibers include natural fibers, recycled fibers, semi-synthetic fibers, metal fibers, glass fibers, carbon fibers, ceramic fibers, and known chemical fibers. The fabric may be woven or nonwoven and may be made, for example, using the fibers described above.These materials may be used alone, or two or more may be combined, mixed, or composited. The shape of the substrate is not particularly limited, and examples thereof include plate-like, sheet-like, film-like, rod-like, spherical, fibrous, powder-like, lens-like, and other regular or irregular shapes.

[0132] (Curing Method) In the present disclosure, the curing method and curing conditions are selected depending on whether the composition for hard coat is active energy ray-curable and / or thermosetting. Furthermore, the curing conditions (e.g., the type of light source and the amount of light irradiation in the case of active energy ray-curable compositions, and the heating temperature and heating time in the case of thermosetting compositions) are appropriately selected depending on the type and amount of polymerization initiator contained in the composition for hard coat, the types of other polymerizable compounds, and the like.

[0133] (1) Active Energy Ray Curing Method When the hard coat composition according to the present disclosure is an active energy ray-curable composition, the curing method may involve irradiating the composition with active energy rays using a known active energy ray irradiation device or the like. Examples of active energy rays include electron beams, ultraviolet rays, visible light, and X-rays, among others. Light is preferred, and ultraviolet rays are more preferred from the viewpoint of being able to use inexpensive devices. Examples of ultraviolet ray irradiation devices include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, ultraviolet (UV) electrodeless lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, and light-emitting diodes (LEDs). The light irradiation intensity of the coating film coated with the composition for hard coating according to the present disclosure may be selected depending on the purpose, application, etc., and the light irradiation intensity in the light wavelength region (which differs depending on the type of photopolymerization initiator, but preferably light with a wavelength of 220 nm to 460 nm is used) effective for activating the active energy ray polymerization initiator (which is referred to as a photopolymerization initiator in the case of photocurable initiators) is 0.1 mW / cm ２ ~1000mW / cm ２The irradiation energy should be appropriately set depending on the type of active energy ray, the formulation, etc. The light irradiation time of the coating may also be selected depending on the purpose, application, etc., and it is preferable that the integrated light amount, which is expressed as the product of the light irradiation intensity and the light irradiation time in the light wavelength range, is 10 mJ / cm. ２ ~7,000mJ / cm ２ It is preferable that the light irradiation time is set so that the integrated light amount is 200 mJ / cm ２ ~5,000mJ / cm ２ More preferably, 500 mJ / cm ２ ~4,000mJ / cm ２ When the integrated light amount is within the above range, the curing of the composition proceeds smoothly, and a uniform cured product can be easily obtained.

[0134] Furthermore, heat curing can be appropriately combined before and / or after photocuring. For example, a substrate having a shaded area when irradiated with light may be impregnated with the composition, and then the composition may be irradiated with light to first cure the composition in the area exposed to light, and then heat may be applied to cure the composition in the area not exposed to light, thereby performing two-stage curing. There are no particular limitations on such substrates, and examples include substrates with complex shapes such as fabric-like, fibrous, powder-like, porous, and uneven, and may also have a shape in which two or more of these shapes are combined.

[0135] (2) Thermal Curing Method When the hard coat composition according to the present disclosure is a thermosetting composition, the curing method and curing conditions are not particularly limited. The curing temperature is preferably 80°C to 200°C, more preferably 100°C to 180°C, and even more preferably 110°C to 150°C. The curing temperature may be constant or may be increased. A combination of temperature increase and decrease may also be used. The curing time is appropriately selected depending on the type of thermal polymerization initiator, the content ratio of other components, and the like, and is preferably 10 minutes to 360 minutes, more preferably 30 minutes to 300 minutes, and even more preferably 60 minutes to 240 minutes. By curing the composition under the above-mentioned preferred conditions, a uniform cured film free of blistering, cracks, etc. can be formed.

[0136] (Applications of hard coats, etc.) The hard coat composition according to the present disclosure has excellent hardness and can therefore be suitably applied to hard coats. Furthermore, by curing the hard coat composition according to the present disclosure, a hard coat with excellent flex resistance can be obtained. The hard coat composition according to the present disclosure may be provided on a substrate; for example, a substrate provided with a hard coat can be obtained by curing the hard coat composition applied to the substrate. The hard coat composition according to the present disclosure may contain various components as needed. Because the hard coat according to the present disclosure has excellent flex resistance, it can be suitably used in flexible devices such as bendable foldable devices and rollable rollable devices, displays such as electronic paper and bendable flexible displays, optical components such as lenses, and the like.

[0137] EXAMPLES Next, the present invention will be described in detail based on examples and comparative examples, but the present invention is not limited to the following examples.

[0138] (Measurement of Weight-Average Molecular Weight) The weight-average molecular weight (Mw) of the silsesquioxane derivative in each Example and Comparative Example was measured as follows: Specifically, separation was performed by gel permeation chromatography (HLC-8320GPC, manufactured by Tosoh Corporation, hereinafter abbreviated as "GPC") in a tetrahydrofuran solvent at 40°C using a GPC column "TSK gel SuperMultipore HZ-M" (manufactured by Tosoh Corporation), and the molecular weight in terms of standard polystyrene was calculated from the retention time.

[0139] (Measurement of Viscosity) The viscosity of the silsesquioxane derivatives in each of the Examples and Comparative Examples was measured at 25° C. using a TVE22H viscometer manufactured by Toki Sangyo Co., Ltd.

[0140] (Measurement of Density) The density of the silsesquioxane derivatives in each of the Examples and Comparative Examples was measured in accordance with JIS K0061-7.

[0141] (Calculation of Molar Ratio of Each Structural Unit of Silsesquioxane Derivative) The molar ratio of each structural unit of the silsesquioxane derivative in each Example and Comparative Example was calculated based on the molar ratio of the sample dissolved in deuterated chloroform. １ H-NMR analysis is carried out, and further analysis is carried out as necessary. ２９ The calculation was also carried out by Si-NMR analysis.

[0142] (Synthesis of Silsesquioxane Derivatives) <Synthesis Example 1> (3-acryloyloxy)propyltrimethoxysilane (96.1 g, 0.41 mol), 3-methacryloxypropyltrimethoxysilane (67.1 g, 0.27 mol), dimethoxydimethylsilane (2.2 g, 0.02 mol), 2-propanol (48 g), and hydroquinone (0.06 g) were weighed into a 1 L four-neck round-bottom flask equipped with a thermometer, a dropping funnel, and a stirring blade, and the mixture was stirred thoroughly in a water bath at about 30° C. Separately, an aqueous solution was prepared by mixing 35% hydrochloric acid (0.7 g, 6.8 mmol as hydrogen chloride) and pure water (104 g). The aqueous solution prepared in the mixture was added dropwise from the dropping funnel over approximately 1 hour while the reaction mixture was heated to 60°C and stirred. The mixture was then further stirred at 60°C for 1 hour, cooled to room temperature (25°C, hereinafter the same), and allowed to stand overnight. The amount of water added was 2.8 moles relative to the total amount of hydrolyzable groups in the starting organosilicon compound. The reaction mixture was then heated to 60°C while the solvent and other components in the reaction mixture were distilled off under reduced pressure to obtain 120 g of a colorless, transparent liquid silsesquioxane derivative, designated S1.

[0143] Synthesis Example 2 The same procedures as in Synthesis Example 1 were repeated, except that the ingredients were changed to (3-acryloyloxy)propyltrimethoxysilane (98.4 g, 0.42 mol), 3-methacryloxypropyltrimethoxysilane (69.5 g, 0.28 mol), and dimethoxydimethylsilane (0.42 g, 3.5 mmol), to obtain 120 g of a silsesquioxane derivative designated as S2.

[0144] Synthesis Example 3 The same procedures as in Synthesis Example 1 were repeated, except that 3-methacryloxypropyltrimethoxysilane was not used and the amounts of (3-acryloyloxy)propyltrimethoxysilane (75.2 g, 0.32 mol), dimethoxydimethylsilane (21.5 g, 0.18 mol), and water added were changed to 1.4 molar equivalents relative to the total amount of hydrolyzable groups in the starting organosilicon compound, to obtain 66 g of a silsesquioxane derivative designated S3.

[0145] Synthesis Example 4 The same procedures as in Synthesis Example 1 were repeated, except that dimethoxydimethylsilane was not used and the ingredients were changed to (3-acryloyloxy)propyltrimethoxysilane (105 g, 0.45 mol) and 3-methacryloxypropyltrimethoxysilane (74.5 g, 0.3 mol), to obtain 130 g of a silsesquioxane derivative designated as S4.

[0146] Synthesis Example 5: Except for changing the amount of water added to 3.5 moles relative to the total amount of hydrolyzable groups in the raw material organosilicon compound, the same procedures as in Synthesis Example 4 were repeated to obtain 125 g of a silsesquioxane derivative designated S5.

[0147] Synthesis Example 6 Except for changing the amount of water added to 25 moles of the total amount of hydrolyzable groups in the raw material organosilicon compound, the same procedure as in Synthesis Example 4 was repeated to obtain 125 g of a silsesquioxane derivative designated S6.

[0148] Synthesis Example 7 Except for changing the ingredients to (3-acryloyloxy)propyltrimethoxysilane (104 g, 0.446 mol) and 1,3-divinyltetramethyldisiloxane (3.5 g, 0.02 mol), the same procedures as in Synthesis Example 4 were repeated to obtain 130 g of a silsesquioxane derivative designated as S1.

[0149] Synthesis Example 8 (3-acryloyloxy)propyltrimethoxysilane (469 g, 2 mol), 2-propanol (337 g), and hydroquinone (0.07 g) were weighed into a 2 L four-neck round-bottom flask equipped with a thermometer, a dropping funnel, and a stirring blade, and the mixture was stirred thoroughly in a water bath at approximately 30°C. Separately, an aqueous solution was prepared by mixing triethylamine (20.2 g, 0.2 mol), pure water (108 g), and 2-propanol (30 g). The aqueous solution prepared in the mixture was added dropwise from the dropping funnel over approximately 1 hour while the reaction solution was heated to 60°C and stirred, and then further stirred at 60°C for 3 hours. The amount of water added was 1.0 moles relative to the total amount of hydrolyzable groups in the starting organosilicon compound. The reaction was then neutralized with an aqueous solution of 95% sulfuric acid (10.5 g, 0.11 mol) and pure water (90 g), and the organic solvent in the reaction solution was distilled off under reduced pressure while the reaction solution was heated to 60° C. Xylene was added thereto, and the solution was washed with saturated saline to remove moisture. Thereafter, the organic solvent in the solution was distilled off under reduced pressure while the solution was heated to 60° C., yielding 320 g of a colorless, transparent liquid silsesquioxane derivative designated as S8.

[0150] Synthesis Example 9 Except for changing (3-acryloyloxy)propyltrimethoxysilane to 3-methacryloxypropyltrimethoxysilane (497 g, 2 mol) and changing triethylamine to a 25% aqueous solution of tetramethylammonium hydroxide (7.29 g, net 0.02 mol), all operations were conducted in the same manner as in Synthesis Example 8, to obtain 350 g of a silsesquioxane derivative designated as S9.

[0151] Synthesis Example 10 A commercially available silsesquioxane derivative was designated as S10. Table 1 shows the molar ratio of each structural unit, the ratio of the sum of the peak heights of the cage silsesquioxane derivative, and the like.

[0152] Synthesis Example 11 A commercially available silsesquioxane derivative was designated as S11. Table 1 shows the molar ratio of each structural unit, the ratio of the sum of the peak heights of the cage silsesquioxane derivative, and the like.

[0153] Examples 1 to 7 and Comparative Examples 1 to 4 Preparation of Photocurable Coating Agents (Coating Compositions) To 1 part by mass of the silsesquioxane derivatives (S1 to S11) obtained in Synthesis Examples 1 to 11, 0.03 parts by mass of 2-hydroxy-2-methyl-1-phenylpropan-1-one and 1 part by mass of propylene glycol monobutyl ether were added, and the mixture was stirred using a planetary centrifugal mixer to prepare photocurable coating agents.

[0154] - Preparation of photocured film - The photocurable coating agents prepared as described above were each applied to a 50 μm thick PET film (Cosmoshine A4300, manufactured by Toyobo Co., Ltd.). Specifically, each photocurable coating agent was applied using a No. 8 bar coater, and the applied photocurable coating agent was then dried at 60°C for 10 minutes, after which it was irradiated with ultraviolet light under the following conditions to cure, producing a photocured film. The film thickness was approximately 5 μm. - UV irradiation conditions - Lamp: High-pressure mercury lamp (ECS-4011GX, manufactured by iGraphics Co., Ltd.) Lamp height: 10 cm Conveyor speed: 5.75 m / min Integrated light intensity per pass: 360 mJ / cm2 (UV-A, measured value using UV POWER PUCK II, manufactured by EIT Co., Ltd.) Atmosphere: Air Number of passes: 10

[0155] (Matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI TOF-MS) measurement) The ratio of the sum of the peak heights of the cage silsesquioxane derivatives contained in S1 to S11 obtained in Synthesis Examples 1 to 11 was measured and calculated under the following conditions. First, an acetone solution prepared by adjusting each of the samples S1 to S11 to 1 mg / mL (hereinafter referred to as the "sample solution"), an acetone solution prepared by adjusting trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malonnitrile (DCTB) to 10 mg / mL (hereinafter referred to as the "DCTB solution"), and an acetone solution prepared by adjusting sodium trifluoroacetate to 2 mg / mL (hereinafter referred to as the "STFA solution") were prepared, respectively. Next, the sample solution, DCTB solution, and STFA solution were mixed in a volume ratio of 1:1:1, dropped onto a measurement plate, and air-dried to obtain a measurement sample. This measurement sample was subjected to mass analysis using a matrix-assisted laser desorption / ionization time-of-flight mass spectrometer (JEOL "JMS-S3000"), and the ratio of the sum of the peak heights of the cage silsesquioxane derivatives was calculated from the obtained peak intensity ratios.

[0156] (Measurement of Condensation Ratio) ２９ From the results of SiNMR spectrum measurement (measuring device: AVANCE III 400 manufactured by Bruker Biospin), the area ratios of T3, T2, T1, T0, D2, D1, and D0 were determined, and the condensation ratio was calculated using the following formula. ２９ In the results of Si NMR spectrum measurement, the peaks are derived from a structure in which all three hydrolyzable groups bonded to Si are condensed, T2 and T1 are derived from a structure in which two and one hydrolyzable groups bonded to Si are condensed, respectively, and TO is a peak derived from a structure in which no hydrolyzable group bonded to Si is condensed. Similarly, D2 and D1 are derived from a structure in which all two hydrolyzable groups bonded to Si are condensed, and one hydrolyzable group is condensed, and DO is a peak derived from a structure in which no hydrolyzable group is condensed. Condensation rate (%) = (0 x TO + 1 x T1 + 2 x T2 + 3 x T3 + 0 x DO + 1 x D1 + 2 x D2) / (3 x (TO + T1 + T2 + T3) + 2 x (DO + D1 + D2)) x 100

[0157] (Measurement of cure shrinkage) According to JIS Z8804:2012, the specific gravity of the composition before curing was measured at 25°C using a pycnometer. Furthermore, according to the submerged weighing method defined in JIS Z8807, the specific gravity of the cured product at 25°C was measured. The cure shrinkage was calculated by applying the specific gravity measured above to the following formula: Cure shrinkage (%) = (((specific gravity of cured product) - (specific gravity before curing)) / (specific gravity before curing)) x 100

[0158] (Measurement of Indentation Elastic Modulus) The elastic modulus of the photocured film prepared as described above was measured as follows. Specifically, indentation hardness was measured at 23°C and a strain rate of 0.05 / s using a nanoindenter (Nano Indenter G200 manufactured by Agilent Technologies, Inc., using a Berkovich indenter). The elastic modulus was calculated by averaging the modulus values ​​at indentation depths of 100 nm to 400 nm. The results are shown in Table 1.

[0159] (Pencil Hardness Test) The photocured film prepared as described above was subjected to a pencil hardness test in accordance with JIS K5600-5-4 (1999). The experimental results are shown in Table 1.

[0160] (Evaluation of Continuous Flexibility (Flex Resistance)) The photocured film prepared as described above was set in a durability tester DMLHP-CS manufactured by Yuasa System Co., Ltd. with the hard coat surface facing outward, and a repeated bending test was performed 50,000 times at a bending radius R of 5.0 mm and a speed of 1 time / 2 seconds. A rating of A was given if no cracks were observed in the hard coat layer, a rating of B was given if cracks were observed between 10,000 and 50,000 bending tests, and a rating of F was given if cracks were observed during bending tests less than 10,000 times. The results are shown in Table 1. The test was performed in a constant temperature and humidity environment set at a temperature of 23°C and a humidity of 50% RH.

[0161]

[0162] The percentage of the cage peaks in Table 1 represents the percentage of the sum of the peak heights of the cage silsesquioxane derivatives having 8 silicon atoms, the cage silsesquioxane derivatives having 10 silicon atoms, and the cage silsesquioxane derivatives having 12 silicon atoms relative to the total amount of the hard coat composition, as measured from the peak intensity ratios in the region of molecular weights of 4,000 or less in matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI TOF-MS).

[0163] As shown in Table 1, the hard coat compositions of Examples 1 to 7 provided hard coats superior in flex resistance compared to Comparative Examples 1 to 4. Furthermore, the hard coat compositions of Examples 1 to 7 provided hard coats superior in surface hardness.

[0164] The disclosure of Japanese Patent Application No. 2023-205228, filed on December 5, 2023, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A hard coat composition comprising a silsesquioxane derivative represented by the following formula (1), wherein the condensation rate of the silsesquioxane derivative represented by the formula (1) is 94% or less, and the cure shrinkage rate of the cured product obtained after curing is 9% or less. (In formula (1), R １ and R ２ each independently represents an alkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 3 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, or an aralkylene group having 7 to 12 carbon atoms; R ３ is an alkyl group having 1 to 6 carbon atoms; R ４ and R ５ each independently represents a hydrogen atom, a saturated or unsaturated chain hydrocarbon group having 1 to 20 carbon atoms, a saturated or unsaturated cyclic hydrocarbon group having 3 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms; R ６ is an organic group having 2 to 12 carbon atoms and at least one of an ethylenically unsaturated bond and a carbon-carbon triple bond, R ７ and R ８ are each independently an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms, ５ may be the same or different, and multiple R ７ may be the same or different, and multiple R ８ may be the same or different, R １ ~R ８ may each independently be partially substituted with a substituent or a halogen atom, t, u, v, w, x, y, and z each independently represent 0 or a positive number, and at least one of u and v is a positive number.

2. The hard coat composition according to claim 1, wherein in matrix-assisted laser desorption ionization time-of-flight mass spectrometry of the silsesquioxane derivative, the sum of the peak heights of a cage-type silsesquioxane derivative having 8 silicon atoms, a cage-type silsesquioxane derivative having 10 silicon atoms, and a cage-type silsesquioxane derivative having 12 silicon atoms, which are shown in the region of a molecular weight of 4,000 or less, is less than 18% of the sum of all the peak heights.

3. The composition for hard coat according to claim 1, wherein the composition for hard coat is cured on a substrate to produce a hard coat having a thickness of 10 μm, and the hard coat does not break even when the hard coat is bent outward 50,000 times in succession with a bending radius R of 5 mm.

4. The composition for hard coat according to claim 1, wherein the indentation modulus of the cured product obtained after curing at 23° C. is 4 GPa or more.

5. The hard coat composition according to claim 1, further comprising a polymerization initiator.

6. A hard coat obtained by curing the composition for hard coat according to any one of claims 1 to 5.

7. A substrate provided with the hard coat according to claim 6.

8. R ｎ Six ｐ (n represents an integer of 0 to 3, p represents an integer of 1 to 4, n+p=4, R represents a group bonded to a silicon atom in the silsesquioxane derivative via a carbon atom, and X represents a hydrolyzable group), using an organic solvent and adding 1.5 molar equivalents or more of water based on the total amount of hydrolyzable groups possessed by the organosilicon compound.

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