Ultraviolet-curable composition, cured film, and organic el display device

Abstract

The purpose of the present invention is to provide an ultraviolet-curable composition that has excellent coating stability and can form a cured film having excellent low-dielectric properties and heat resistance. The present invention provides an ultraviolet-curable composition comprising: a mixture containing two or more monovinyl ethers represented by formula (A): CH2=CH-O-RA (in formula (A), RA represents a C8-18 alkyl group); a divinyl ether represented by formula (B): CH2=CH-O-RB-O-CH=CH2 (in formula (B), RB represents a C2-20 divalent hydrocarbon group); a polymer including a main chain composed of a hydrocarbon and a side chain having a polymerizable functional group; and a photoacid generator.

Description

UV-curable composition, cured film, and organic EL display device

[0001] The present invention relates to an ultraviolet-curable composition, a cured film, and an organic EL display device.

[0002] Because organic EL elements consume little power, they can be effectively used in displays, lighting devices, etc. Because organic EL elements are susceptible to deterioration due to moisture and oxygen in the atmosphere, they can be sealed by forming a cured film by applying a curable composition by a method such as an inkjet method.

[0003] In recent years, in order to solve the above problems, development of curable compositions to be used for forming cured films has been progressing. For example, Patent Document 1 proposes a curable composition to be used for sealing organic EL elements, which contains a predetermined cationically polymerizable compound and a polymerization initiator, with the aim of achieving both stability in application by an inkjet method and a low dielectric constant.

[0004] International Publication No. 2021 / 131790

[0005] Here, since organic EL elements can generate heat during use, it is desirable that the cured film of the organic EL element has excellent heat resistance and generates little outgassing due to heat generation.

[0006] However, conventional curable compositions have room for improvement in terms of excellent coating stability by a predetermined coating method (hereinafter, sometimes referred to as "coating stability"), imparting excellent low dielectric properties to a cured film, and imparting excellent heat resistance to a cured film.

[0007] Therefore, an object of the present invention is to provide an ultraviolet-curable composition that has excellent coating stability and can impart excellent low dielectric properties and heat resistance to a cured film. Another object of the present invention is to provide a cured film obtained using the ultraviolet-curable composition. Another object of the present invention is to provide an organic EL display device including the cured film.

[0008] The present inventors have conducted extensive research with the aim of solving the above-mentioned problems, and have newly discovered that the above-mentioned problems can be solved by an ultraviolet-curable composition containing a mixture containing two or more predetermined monovinyl ethers, a predetermined divinyl ether, a predetermined polymer, and a photoacid generator, thereby completing the present invention.

[0009] That is, an object of the present invention is to advantageously solve the above-mentioned problems, and [1] the present invention provides a compound represented by the following formula (A): CH ２ =CH-O-R Ａ (A) (In formula (A), R Ａ represents an alkyl group having 8 to 18 carbon atoms.) and a mixture containing two or more monovinyl ethers represented by the following formula (B): CH ２ =CH-O-R Ｂ —O—CH═CH ２ (B) (In formula (B), R Ｂ represents a divalent hydrocarbon group having 2 to 20 carbon atoms. The ultraviolet-curable composition includes a divinyl ether represented by the formula (I), a polymer including a main chain made of hydrocarbon and a side chain having a polymerizable functional group, and a photoacid generator. In this specification, the term "main chain" refers to the relatively longest bonded chain in the polymer molecule. Here, if a cyclic structure is present in the longest bonded chain, the cyclic structure is also included in the main chain. The hydrocarbon of the main chain typically does not contain a polar group. In this specification, the term "side chain" refers to a bonded chain branching from the main chain. In this specification, the above-mentioned mixture also includes a mixture in which two or more specific monovinyl ethers are added and mixed when preparing the ultraviolet-curable composition.

[0010] [2] In the ultraviolet-curable composition according to [1] above, the number-average molecular weight of the polymer is preferably not more than 5000. In this specification, the number-average molecular weight is determined by gel permeation chromatography (GPC) as a polystyrene-equivalent value, and can be measured, for example, according to the method described in the Examples.

[0011] [3] In the ultraviolet-curable composition according to the above [1] or [2], the hydrocarbon of the main chain of the polymer preferably contains an alicyclic structure.

[0012] [4] In the ultraviolet-curable composition according to [3] above, it is preferable that the polymer contains a structural unit (I) represented by the following formula (I) and a structural unit (II) represented by the following formula (II):

[0013]

[0014] Here, in formula (I), R １ ~R ３ each independently represents a hydrogen atom, an alkyl group, or an aromatic ring group; R １ ~R ３ may be bonded to form a ring, and R ４ represents a hydrogen atom or an alkyl group, X represents an alkylene group having 1 to 10 carbon atoms, and m represents 0, 1, or 2. ５ ~R ８ each independently represents a hydrogen atom, an alkyl group, or an aromatic ring group; R ５ ~R ８ may be bonded to form a ring, and n represents 0, 1 or 2.

[0015] [5] In the ultraviolet-curable composition according to the above [1] or [2], the hydrocarbon of the main chain of the polymer preferably has a linear structure.

[0016] [6] In the ultraviolet-curable composition according to [5] above, the polymer preferably contains a structural unit (i) represented by the following formula (i):

[0017]

[0018] Here, in formula (i), R ９ and R １０ each independently represents a hydrogen atom or a methyl group, R １１ represents a methylene group or a phenylene group, and R １２ is —CO—, a methylene group or —CH ２ -C ６ H ４ - indicates R １３represents a hydrogen atom or an alkyl group, and o to r each independently represent 0 or 1, provided that when o is 1, p represents 1.

[0019] [7] In the ultraviolet-curable composition according to any one of [1] to [6] above, the viscosity of the mixture is preferably 20 mPa s or less. In this specification, the viscosity of the mixture can be measured according to the method described in the Examples.

[0020] [8] In the ultraviolet-curable composition according to any one of [1] to [7] above, the mixture contains the R Ａ a monovinyl ether A having 8 to 12 carbon atoms, and Ａ and a monovinyl ether B having 13 or more and 18 or less carbon atoms.

[0021] [9] In the ultraviolet-curable composition according to [8] above, it is preferable that the total content of the monovinyl ether A in the mixture is 50.5% by mass or more and 80.0% by mass or less, and the total content of the monovinyl ether B in the mixture is 20.0% by mass or more and 49.5% by mass or less.

[0022]

[10] In the ultraviolet-curable composition according to any one of [1] to [7] above, it is preferable that the mixture contains monovinyl ether C that is liquid at 25°C and monovinyl ether D that is solid at 25°C.

[0023]

[11] In the ultraviolet-curable composition according to

[10] above, it is preferable that the total content of the monovinyl ether C in the mixture is 69.4% by mass or more and 99.0% by mass or less, and the total content of the monovinyl ether D in the mixture is 1.0% by mass or more and 30.6% by mass or less.

[0024]

[12] In the ultraviolet-curable composition according to any one of the above [1] to

[11] , the R Ｂ The content of the divinyl ether in which the hydrocarbon group contains an alicyclic structure is preferably 100 parts by mass or more based on 100 parts by mass of the polymer.

[0025]

[13] In the ultraviolet-curable composition according to any one of [1] to

[12] above, the content of the mixture is preferably 140 parts by mass or more relative to 100 parts by mass of the polymer.

[0026] Another object of the present invention is to advantageously solve the above-mentioned problems, and

[14] the present invention is a cured film obtained using the ultraviolet-curable composition according to any one of [1] to

[13] above.

[0027] The present invention also aims to advantageously solve the above-mentioned problems, and

[15] the present invention is an organic EL display device comprising a support substrate, an organic EL element disposed on the support substrate, and a sealing layer covering the organic EL element, wherein the sealing layer is made of the cured film according to

[14] above.

[0028] According to the present invention, there is provided an ultraviolet-curable composition that has excellent coating stability and can impart excellent low dielectric properties and heat resistance to a cured film. Further, according to the present invention, there is provided a cured film obtained using the ultraviolet-curable composition. Further, according to the present invention, there is provided an organic EL display device including the cured film.

[0029] 1 is a schematic cross-sectional view showing an example of an organic EL display device of the present invention.

[0030] Here, the ultraviolet-curable composition of the present invention is not particularly limited, and can be used when forming a cured film that can be provided on electronic components such as integrated circuit elements, organic EL elements, and semiconductor packages, by a coating method such as an inkjet method. In particular, the ultraviolet-curable composition of the present invention can be particularly suitably used when producing an insulating sealing layer that can be provided on organic EL display devices, etc. Note that the ultraviolet-curable composition of the present invention is not particularly limited as long as it is curable by ultraviolet light, but from the viewpoint of application to a UVLED light source, it is preferably curable by light containing ultraviolet light with a wavelength of 365 nm or more and 405 nm or less.

[0031] (Ultraviolet-Curable Composition) The ultraviolet-curable composition of the present invention is a compound represented by the following formula (A): CH ２ =CH-O-R Ａ (A) (In formula (A), R Ａrepresents an alkyl group having 8 to 18 carbon atoms.) and a mixture containing two or more monovinyl ethers represented by the following formula (B): CH ２ =CH-O-R Ｂ —O—CH═CH ２ (B) (In formula (B), R Ｂ represents a divalent hydrocarbon group having from 2 to 20 carbon atoms.), a polymer including a main chain made of hydrocarbon and a side chain having a polymerizable functional group, a photoacid generator, and optionally other components. The ultraviolet-curable composition as described above has excellent coating stability and can impart excellent low dielectric properties and heat resistance to a cured film.

[0032] <Monovinyl ether mixture> The monovinyl ether mixture contained in the ultraviolet curable composition is a monovinyl ether mixture represented by the following formula (A): CH ２ =CH-O-R Ａ (A) In the formula (A), R Ａ represents an alkyl group having 8 to 18 carbon atoms. When the ultraviolet-curable composition contains the monovinyl ether mixture as described above, the ultraviolet-curable composition can exhibit excellent coating stability. Here, the term "monovinyl ether mixture containing two or more monovinyl ethers represented by formula (A)" refers to a monovinyl ether mixture containing two or more monovinyl ethers represented by formula (A) and R Ａ The monovinyl ether mixture is not limited to a mixture of two or more monovinyl ethers having different carbon numbers, and R Ａ This means that the monovinyl ether mixture also includes a monovinyl ether mixture containing two or more monovinyl ethers having the same number of carbon atoms but different chemical structures. The monovinyl ether mixture may optionally further contain a monovinyl ether other than the monovinyl ether represented by formula (A).

[0033] Examples of the monovinyl ether represented by formula (A) include R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 , R 20 , R Ａ monovinyl ether having 8 carbon atoms; n-decyl vinyl ether, etc. Ａmonovinyl ether having 10 carbon atoms; n-dodecyl vinyl ether, etc. Ａ monovinyl ethers having 12 carbon atoms, such as n-tetradecyl vinyl ether; Ａ monovinyl ether having 14 carbon atoms, such as n-hexadecyl vinyl ether; Ａ monovinyl ether having 16 carbon atoms, such as n-octadecyl vinyl ether; Ａ and the like.

[0034] In one embodiment of the present invention, the monovinyl ether mixture comprises R Ａ a monovinyl ether A having 8 to 12 carbon atoms, and R Ａ and monovinyl ether B having a carbon number of 13 or more and 18 or less. When the monovinyl ether mixture contains monovinyl ether A, the coating stability can be improved, and when the monovinyl ether mixture contains monovinyl ether B, the low dielectric properties and heat resistance of the obtained cured film can be improved. Therefore, when the monovinyl ether mixture contains monovinyl ether A and monovinyl ether B, the coating stability can be effectively improved, and the low dielectric properties and heat resistance of the obtained cured film can be effectively improved. Note that the monovinyl ether mixture preferably contains R Ａ may contain one or more monovinyl ethers A having 8 to 12 carbon atoms, R Ａ The vinyl monomer may contain one or more monovinyl ethers B having 13 or more and 18 or less carbon atoms.

[0035] In the monovinyl ether mixture, the total content of monovinyl ether A is preferably 50.5% by mass or more, more preferably 60.0% by mass or more, preferably 80.0% by mass or less, and more preferably 70.0% by mass or less, and the total content of monovinyl ether B is preferably 20.0% by mass or more, more preferably 30.0% by mass or more, preferably 49.5% by mass or less, and more preferably 40.0% by mass or less. When the total content of monovinyl ether A and the total content of monovinyl ether B in the monovinyl ether mixture are each within the above ranges, coating stability can be more effectively improved, and the low dielectric properties and heat resistance of the obtained cured film can be more effectively improved.

[0036] In the monovinyl ether mixture, the mass ratio of monovinyl ether A to monovinyl ether B (monovinyl ether A / monovinyl ether B) is preferably 0.010 or more, more preferably 0.100 or more, even more preferably 0.900 or more, even more preferably 1.500 or more, and preferably 5.000 or less, more preferably 3.000 or less, and even more preferably 2.000 or less. When the mass ratio of monovinyl ether A to monovinyl ether B is within the above range, coating stability can be more effectively improved, and the low dielectric properties and heat resistance of the obtained cured film can be more effectively improved.

[0037] In one embodiment of the present invention, the monovinyl ether mixture preferably contains monovinyl ether C that is liquid at 25°C and monovinyl ether D that is solid at 25°C. When the monovinyl ether mixture contains monovinyl ether C, the coating stability can be improved, and when the monovinyl ether mixture contains monovinyl ether D, the low dielectric properties and heat resistance of the resulting cured film can be improved. Therefore, when the monovinyl ether mixture contains monovinyl ether C and monovinyl ether D, the coating stability can be effectively improved, and the low dielectric properties and heat resistance of the resulting cured film can be effectively improved. Here, examples of monovinyl ether C that is liquid at 25°C include n-octyl vinyl ether, isooctyl vinyl ether, 2-ethylhexyl vinyl ether, n-decyl vinyl ether, n-dodecyl vinyl ether, n-tetradecyl vinyl ether, and n-hexadecyl vinyl ether. Examples of monovinyl ether D that is solid at 25°C include n-octadecyl vinyl ether. The monovinyl ether mixture may contain one or more monovinyl ethers C that are liquid at 25°C, and may contain one or more monovinyl ethers D that are solid at 25°C.

[0038] In the monovinyl ether mixture, the total content of monovinyl ether C is preferably 69.4% by mass or more, more preferably 80.0% by mass or more, and even more preferably 90.0% by mass or more, and is preferably 99.0% by mass or less, and more preferably 95% by mass or less, and the total content of monovinyl ether D is preferably 1.0% by mass or more, preferably 5.0% by mass or more, and is preferably 30.6% by mass or less, more preferably 20.0% by mass or less, and even more preferably 10.0% by mass or less. When the total content of monovinyl ether C and the total content of monovinyl ether D in the monovinyl ether mixture are each within the above ranges, coating stability can be more effectively improved, and the low dielectric properties and heat resistance of the obtained cured film can be more effectively improved.

[0039] In the monovinyl ether mixture, the mass ratio of monovinyl ether C to monovinyl ether D (monovinyl ether C / monovinyl ether D) is preferably 2.000 or more, more preferably 3.000 or more, even more preferably 6.000 or more, even more preferably 10.000 or more, and is preferably 20.000 or less, more preferably 15.000 or less, and even more preferably 12.000 or less. When the mass ratio of monovinyl ether C to monovinyl ether D is within the above range, coating stability can be more effectively improved, and the low dielectric properties and heat resistance of the obtained cured film can be more effectively improved.

[0040] In one embodiment of the present invention, the monovinyl ether mixture preferably contains monovinyl ether α corresponding to monovinyl ether A and monovinyl ether C, and monovinyl ether β corresponding to monovinyl ether B and monovinyl ether D. That is, the monovinyl ether mixture preferably contains monovinyl ether α corresponding to monovinyl ether A and monovinyl ether C, and monovinyl ether β corresponding to monovinyl ether B and monovinyl ether D. Ａ monovinyl ether α having 8 to 12 carbon atoms and being liquid at 25°C; and R Ａ and a monovinyl ether β having a carbon number of 13 or more and 18 or less and being solid at 25°C. When the monovinyl ether mixture contains monovinyl ether α, the coating stability can be improved, and when the monovinyl ether mixture contains monovinyl ether β, the low dielectric properties and heat resistance of the obtained cured film can be achieved. Therefore, when the monovinyl ether mixture contains monovinyl ether α and monovinyl ether β, the coating stability can be effectively improved, and the low dielectric properties and heat resistance of the obtained cured film can be effectively improved.

[0041] The viscosity of the monovinyl ether mixture is preferably 1 mPa·s or more, more preferably 5 mPa·s or more, and preferably 20 mPa·s or less, more preferably 15 mPa·s or less, and even more preferably 10 mPa·s or less. If the viscosity of the mixture is above the lower limit, the low dielectric properties and heat resistance of the resulting cured film can be improved. On the other hand, if the viscosity of the mixture is below the upper limit, the coating stability can be improved.

[0042] The content of the monovinyl ether mixture in the ultraviolet-curable composition is preferably 100 parts by mass or more, more preferably 140 parts by mass or more, based on 100 parts by mass of the polymer. When the content of the mixture is equal to or more than the lower limit based on 100 parts by mass of the polymer, the coating stability can be improved, and the low dielectric properties and heat resistance of the obtained cured film can be improved. Note that the content of the monovinyl ether mixture may be, for example, 300 parts by mass or less, or 250 parts by mass or less, based on 100 parts by mass of the polymer.

[0043] <Divinyl Ether> The divinyl ether contained in the ultraviolet curable composition is a divinyl ether represented by the following formula (B): CH ２ =CH-O-R Ｂ —O—CH═CH ２ (B) In formula (B), R Ｂ represents a divalent hydrocarbon group having from 2 to 20 carbon atoms. When the ultraviolet-curable composition contains the above-mentioned divinyl ether, the ultraviolet-curable composition can exhibit excellent coating stability.

[0044] Here, R Ｂ The number of carbon atoms in the hydrocarbon group must be 2 or more, preferably 4 or more, and more preferably 6 or more, and must be 20 or less, preferably 10 or less, and more preferably 8 or less.

[0045] R ＢThe hydrocarbon group may have a chain structure or may contain a cyclic structure, but preferably contains a cyclic structure. Examples of the cyclic structure include an alicyclic structure and an aromatic ring, but an alicyclic structure is preferred. That is, R Ｂ The hydrocarbon group preferably contains an alicyclic structure. Ｂ If the hydrocarbon group contains an alicyclic structure, the low dielectric properties of the resulting cured film can be improved. The alicyclic structure may be saturated or unsaturated, but is preferably a saturated alicyclic structure. Examples of saturated alicyclic structures include a 1,4-cyclohexylene group.

[0046] The content of the divinyl ether represented by formula (B) in the ultraviolet-curable composition is preferably 40 parts by mass or more, more preferably 80 parts by mass or more, and even more preferably 100 parts by mass or more, and is preferably 240 parts by mass or less, more preferably 200 parts by mass or less, and even more preferably 150 parts by mass or less, based on 100 parts by mass of the polymer. If the content of the divinyl ether represented by formula (B) is equal to or greater than the above lower limit based on 100 parts by mass of the polymer, the low dielectric properties and heat resistance of the obtained cured film can be improved. On the other hand, if the content of the divinyl ether represented by formula (B) is equal to or less than the above upper limit based on 100 parts by mass of the polymer, the decrease in the low dielectric properties and heat resistance of the obtained cured film can be effectively suppressed.

[0047] In the ultraviolet curable composition, R Ｂ The content of the divinyl ether in which the hydrocarbon group contains an alicyclic structure is preferably 70 parts by mass or more, and more preferably 100 parts by mass or more, based on 100 parts by mass of the polymer. Ｂ When the content of the divinyl ether in which the hydrocarbon group contains an alicyclic structure is equal to or greater than the above lower limit relative to 100 parts by mass of the polymer, the low dielectric properties of the obtained cured film can be further improved. Ｂ The content of the divinyl ether in which the hydrocarbon group contains an alicyclic structure is, for example, 300 parts by mass or less, and may be 250 parts by mass or less, based on 100 parts by mass of the polymer.

[0048] The ratio of the content of the monovinyl ether mixture to the content of the divinyl ether represented by formula (B) (content of monovinyl ether mixture / content of divinyl ether represented by formula (B)) is, by mass, preferably 0.5 or more, more preferably 1.0 or more, and preferably 4.0 or less, more preferably 2.0 or less. When the ratio of the content of the monovinyl ether mixture to the content of the divinyl ether represented by formula (B) is within the above range, coating stability can be effectively improved, and the low dielectric properties and heat resistance of the obtained cured film can be effectively improved.

[0049] The polymer contained in the ultraviolet-curable composition contains a main chain made of hydrocarbon and a side chain having a polymerizable functional group. When the ultraviolet-curable composition contains such a polymer, the resulting cured film can be imparted with excellent low dielectric properties and heat resistance.

[0050] Here, examples of the polymerizable functional group that the side chain of the polymer has include a vinyl group (-CH=CH ２ ), 1-methylvinyl group (—C(CH ３ ) = CH ２ ), 1-fluorovinyl group (—CF═CH ２ ), maleimide group, etc. Among them, vinyl group and 1-methylvinyl group are preferred. Here, as the polymerizable functional group, vinyl group (-CH=CH ２ Examples of the side chain having a vinyl group (-CH=CH ２ ), an acryloyloxy group (—O—CO—CH═CH ２ ), acryloyl group (—CO—CH═CH ２ ), an allyl group (—CH ２ -CH=CH ２ ), styryl group (-C ６ H ４ -CH=CH ２ ), vinyl ether group (—O—CH═CH ２ ), vinyl ester group (—CO—O—CH═CH ２ ), an acrylamide group (—NR—CO—CH═CH ２ ) (R is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms), an N-vinylamide group (—CO—NR—CH═CH ２) (R is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms). Examples of the polymerizable functional group include a 1-methylvinyl group (-C(CH ３ ) = CH ２ Examples of the side chain having a 1-methylvinyl group (—C(CH ３ ) = CH ２ ), a methacryloyloxy group (—O—CO—C(CH ３ ) = CH ２ ), a methacryloyl group (—CO—C(CH ３ ) = CH ２ ) etc.

[0051] In one embodiment of the present invention, the polymer preferably has a main chain hydrocarbon containing an alicyclic structure. When the main chain hydrocarbon of the polymer contains an alicyclic structure, the low dielectric properties and heat resistance of the obtained cured film can be improved.

[0052] In one embodiment of the present invention, the polymer preferably has a straight-chain hydrocarbon main chain. If the straight-chain hydrocarbon main chain of the polymer has a straight-chain structure, the low dielectric properties of the resulting cured film can be improved. Furthermore, from the viewpoint of the low dielectric properties of the resulting cured film, the straight-chain structure is more preferably a straight-chain alkylene structure.

[0053] The ultraviolet-curable composition of the present invention may contain a polymer in which the hydrocarbon main chain contains an alicyclic structure, and a polymer in which the hydrocarbon main chain has a straight-chain structure.

[0054] Hereinafter, a polymer in which the hydrocarbon main chain contains an alicyclic structure (hereinafter, this may be referred to as a "first polymer") and a polymer in which the hydrocarbon main chain has a linear alkylene structure (hereinafter, this may be referred to as a "second polymer") will be specifically described, but the polymer contained in the ultraviolet-curable composition of the present invention is not limited to these.

[0055] [First Polymer] The first polymer preferably contains a structural unit (I) represented by the following formula (I) and a structural unit (II) represented by the following formula (II). When the first polymer contains the structural unit (I) represented by the following formula (I) and the structural unit (II) represented by the following formula (II), the low dielectric properties and heat resistance of the obtained cured film can be further improved. In addition, in the structural unit (I) represented by the following formula (I) and the structural unit (II) represented by the following formula (II), R １ , R ２ , R ３ , X and a group bonded via X, R ５ , R ６ , R ７ , R ８ corresponds to the side chain, and the other parts correspond to the main chain.

[0056]

[0057] [[Structural unit (I)]] In the structural unit (I), in formula (I), R １ ~R ３ each independently represents a hydrogen atom, an alkyl group, or an aromatic ring group; R １ ~R ３ may be bonded to form a ring.

[0058] Here, R １ ~R ３ The alkyl group that can constitute R is not particularly limited, and examples thereof include unsubstituted alkyl groups having 1 to 5 carbon atoms. １ ~R ３ The alkyl group that can constitute the above is preferably a methyl group or an ethyl group.

[0059] Also, R １ ~R ３ The aromatic ring group that can constitute the above group is not particularly limited, and examples thereof include aromatic rings having 4 to 30 carbon atoms, such as a benzene ring and a naphthalene ring.

[0060] Furthermore, R １ ~R ３ The ring formed by bonding may be a monocyclic ring or a polycyclic ring.

[0061] In the structural unit (I), in formula (I), X represents an alkylene group having 1 to 10 carbon atoms. Here, the alkylene group having 1 to 10 carbon atoms that can constitute X is not particularly limited, but is preferably a chain alkylene group having 1 to 6 carbon atoms such as a methylene group, ethylene group, propylene group, n-butylene group, or isobutylene group, more preferably a linear alkylene group having 1 to 6 carbon atoms such as a methylene group, ethylene group, propylene group, or n-butylene group, still more preferably a linear alkylene group having 1 to 3 carbon atoms such as a methylene group, ethylene group, or propylene group, and particularly preferably a methylene group.

[0062] In the structural unit (I), m in formula (I) represents 0, 1 or 2, preferably 0 or 1, and more preferably 0.

[0063] In the structural unit (I), in formula (I), R ４ represents a hydrogen atom or an alkyl group. ４ The alkyl group that can constitute R is not particularly limited, and examples thereof include unsubstituted alkyl groups having 1 to 5 carbon atoms. ４ The alkyl group that can constitute the above is preferably a methyl group or an ethyl group, more preferably a methyl group.

[0064] As represented by formula (I), the structural unit (I) has a substituted or unsubstituted acryloyl group as a functional group bonded to the cyclic olefin structure via an alkylene group represented by X, thereby enhancing the mobility of the functional group. Therefore, the first polymer containing the structural unit (I) having such a functional group has improved crosslinking reactivity of the functional group. This allows the resulting cured film to have improved low dielectric properties and heat resistance.

[0065] The content of the structural unit (I) in the first polymer is preferably 3 mol % or more, more preferably 10 mol % or more, and preferably 30 mol % or less, more preferably 20 mol % or less, when the total structural units in the first polymer (excluding the molecular weight modifier, if any) is taken as 100 mol %. １ H-NMR and １３It can be measured using a nuclear magnetic resonance (NMR) method such as C-NMR.

[0066] [[Structural unit (II)]] In the structural unit (II), R ５ ~R ８ each independently represents a hydrogen atom, an alkyl group, or an aromatic ring group; R ５ ~R ８ may be bonded to form a ring.

[0067] Here, R ５ ~R ８ The alkyl group that can constitute R is not particularly limited, and examples thereof include １ ~R ３ The alkyl group may be the same as the alkyl group that can constitute the above.

[0068] Also, R ５ ~R ８ The aromatic ring group that can constitute R is not particularly limited, and examples thereof include １ ~R ３ The aromatic ring groups include the same as those that can constitute the above aromatic ring groups.

[0069] Furthermore, R ５ ~R ８ The ring formed by bonding is not particularly limited, and examples thereof include R １ ~R ３ The rings formed by bonding the groups are the same as those formed by bonding the groups.

[0070] In the structural unit (II), n in formula (II) represents 0, 1 or 2, and preferably represents 0 or 1.

[0071] The content of the structural unit (II) in the first polymer is preferably 70 mol% or more, more preferably 80 mol% or more, and is preferably 97 mol% or less, more preferably 90 mol%, when the total structural units in the first particulate polymer (excluding the molecular weight modifier, if any) is 100 mol%.

[0072] [Method for Preparing First Polymer] The method for preparing the first polymer is not particularly limited and can be performed by a conventionally known method. For example, a first polymer containing the structural unit (I) and the structural unit (II) can be prepared by a method including a step of synthesizing a ring-opening polymer by ring-opening polymerization of a norbornene-based monomer (hereinafter referred to as the "ring-opening polymerization step"), a step of subjecting the obtained ring-opening polymer to a hydrogenated ring-opening polymer (hereinafter referred to as the "hydrogenation step"), and a step of subjecting the obtained ring-opening polymer to a modification reaction to obtain a modified product of the hydrogenated ring-opening polymer (hereinafter referred to as the "modification step"). Each step will be described in detail below.

[0073] -Ring-Opening Polymerization Step- In the ring-opening polymerization step, a ring-opening polymer is synthesized by a ring-opening polymerization reaction between a norbornene-based monomer (I) capable of forming the structural unit (I) described above and a norbornene-based monomer (II) capable of forming the structural unit (II) described above.

[0074] Examples of the norbornene-based monomer (I) include 2-norbornene-5-methanol, 2-methyl-2-hydroxymethylbicyclo[2.2.1]hept-5-ene, 2,3-dihydroxymethylbicyclo[2.2.1]hept-5-ene, 3-hydroxytricyclo[5.2.1.0]hept-5-ene, and 2-methyl-2-hydroxymethylbicyclo[2.2.1]hept-5-ene. ２，６ ]deca-4,8-diene, 3-hydroxymethyltricyclo[5.2.1.0 ２，６ ]deca-4,8-diene, 4-hydroxytetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-9-ene, 4-hydroxymethyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-9-ene, 4,5-dihydroxymethyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ]dodec-9-ene, etc. Among these, 2-norbornene-5-methanol is preferred. The norbornene-based monomer (I) can be used alone or in combination of two or more.

[0075] Examples of the norbornene-based monomer (II) include tetracyclo[4.4.0.1 ２，５.1 ７，１０ ] dodec-3-ene (common name: tetracyclododecene), 8-ethylidene-tetracyclo[4.4.0.1 ２，５ .1 ７，１０ ] dodec-3-ene (common name: ethylidenetetracyclododecene), tricyclo[5.2.1.0 ２，６ ]deca-3,8-diene (trivial name: dicyclopentadiene), 1,4-methano-1,4,4a-9a-tetrahydrofluorene (trivial name: methanotetrahydrofluorene), 5-ethylidenebicyclo[2.2.1]hept-2-ene (trivial name: ethylidenenobornene), bicyclo[2.2.1]hept-2-ene (also called "norbornene"), 5-ethyl-bicyclo[2.2.1]hept-2-ene, 5-butyl-bicyclo[2.2.1]hept-2-ene, 5-methylidene-bicyclo[2.2.1]hept-2-ene, 5-vinyl-bicyclo[2.2.1]hept-2-ene, tetracyclo[10.2.1.0 ２，１１ .0 ４，９ ] pentadeca-4,6,8,13-tetraene, 9-methyl-tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-ethyl-tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-methylidene-tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-ethylidene-tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-vinyl-tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-propenyl-tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, pentacyclo[9.2.1.1 ３，９ .0 ２，１０ .0 ４，８ ] pentadeca-5,12-diene, 9-phenyl-tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, tetracyclo[9.2.1.0 ２，１０ .0 ３，８] tetradeca-3,5,7,12-tetraene, pentacyclo[9.2.1.1 ３，９ .0 ２，１０ .0 ４，８ ]pentadeca-12-ene and derivatives thereof. Among these, ethylidenetetracyclododecene is preferred. The derivative refers to one having a substituent in the ring structure. Examples of the substituent that can be contained in the ring structure include an alkyl group, an alkylene group, a vinyl group, an alkoxycarbonyl group, and an alkylidene group. The ring structure of the derivative may have one or more of these substituents. The norbornene monomer (II) can be used alone or in combination of two or more.

[0076] The ring-opening polymerization reaction can be carried out in a solvent according to a known method. The solvent is not particularly limited, and examples thereof include organic solvents such as tetrahydrofuran and toluene. Further, as the molecular weight modifier, ethylene; α-olefins having 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene; non-conjugated dienes such as 1,4-hexadiene, 1,5-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, and 1,7-octadiene, and derivatives thereof, may be used. As the ring-opening polymerization catalyst, a metal catalyst containing a metal such as molybdenum, tungsten, or ruthenium can be used, and among these, a metal catalyst containing ruthenium is preferred. Furthermore, the ring-opening polymerization time is usually from 1 hour to 10 hours, and preferably from 2 hours to 5 hours. The ring-opening polymerization temperature is usually from 20°C to 100°C, and preferably from 20°C to 90°C.

[0077] -Hydrogenation Step- In the hydrogenation step, the ring-opening polymer obtained in the ring-opening polymerization step is subjected to a hydrogenation reaction to synthesize a hydrogenated ring-opening polymer.

[0078] The hydrogenation reaction can be carried out according to a known method. The hydrogenation reaction time, temperature, and pressure are not particularly limited, but the hydrogenation reaction time is usually 1 hour to 10 hours, and preferably 5 hours or less. The hydrogenation reaction temperature is usually 100°C to 200°C, and preferably 100°C to 180°C. The hydrogenation pressure is usually 1 MPa to 10 MPa, and preferably 1 MPa to 5 MPa.

[0079] -Modification Step- In the modification step, a modification reaction is carried out on the terminals of the hydrogenated ring-opening polymer obtained in the ring-opening polymerization step using a modifying agent, thereby synthesizing a modified product of the hydrogenated ring-opening polymer (i.e., a polymer containing the structural units (I) and (II) described above). Here, as the modifying agent, for example, a compound having a methacryloyl group or an acryloyl group can be used. Examples of compounds having a methacryloyl group include methacrylic acid chloride and methacrylic acid anhydride. Furthermore, examples of compounds having an acryloyl group include acrylic acid chloride and acrylic acid anhydride. Among these, from the viewpoint of efficiently carrying out the modification reaction, it is more preferable to use methacrylic acid chloride or acrylic acid chloride.

[0080] Here, the modification reaction is not particularly limited, and can be carried out, for example, by reacting the hydrogenated ring-opening polymer with a modifying agent in a solvent in the presence of a modification reaction catalyst. The modification reaction catalyst is not particularly limited, and examples of suitable catalysts include triethylamine and pyridine. The solvent is also not particularly limited, and examples of suitable solvents include those used in the ring-opening polymerization reaction. The modification reaction temperature and modification reaction time are not particularly limited, and the modification reaction temperature is typically −10° C. or higher and 15° C. or lower, and the modification reaction time is typically 1 hour or higher and 15 hours or lower.

[0081] [Second Polymer] The second polymer preferably contains a structural unit (i) represented by the following formula (i): When the second polymer contains the structural unit (i) represented by the following formula (i), the low dielectric properties and heat resistance of the obtained cured film can be further improved.

[0082]

[0083] In the structural unit (i), in formula (i), R ９ and R １０ each independently represents a hydrogen atom or a methyl group.

[0084] In the structural unit (i), in formula (i), R １１ represents a methylene group or a phenylene group.

[0085] In the structural unit (i), in formula (i), R １２ is —CO—, a methylene group or —CH ２ -C ６ H ４ Indicates -.

[0086] In the structural unit (i), in formula (i), R １３ represents a hydrogen atom or an alkyl group. １３ The alkyl group that can constitute R is not particularly limited, and examples thereof include alkyl groups having 1 to 5 carbon atoms. １３ The alkyl group that can constitute the above is preferably a methyl group or an ethyl group, more preferably a methyl group.

[0087] In the structural unit (i), in formula (i), o to r each independently represent 0 or 1, and when o is 1, p is 1.

[0088] Specific structures of the structural unit (i) contained in the second polymer will be described below, but the second polymer that can be contained in the ultraviolet-curable composition of the present invention is not limited to these.

[0089] In one embodiment of the present invention, the second polymer is represented by formula (i): ９ and R １０ represents a hydrogen atom, and R １３It is preferable that the second polymer contains a structural unit (i) in which o represents a hydrogen atom and o to r represent 0 (hereinafter, this may be referred to as "second polymer A"). When the second polymer contains the structural unit (i), the low dielectric properties and heat resistance of the obtained cured film can be further improved. Note that, as the second polymer containing the structural unit (i), for example, the B series manufactured by Nippon Soda Co., Ltd. can be used.

[0090] In one embodiment of the present invention, the second polymer is represented by formula (i): ９ and R １０ represents a hydrogen atom, and R １１ represents a phenylene group, and R １２ represents —CO—, and R １３ It is preferable that the second polymer contains a structural unit (i) in which p represents a hydrogen atom or a methyl group, o represents 0, and p to r represent 1 (hereinafter, this may be referred to as "second polymer B"). If the second polymer contains the structural unit (i), the low dielectric properties and heat resistance of the resulting cured film can be further improved. Note that the second polymer containing the structural unit (i) can be synthesized, for example, by (meth)acrylic-modifying the hydroxy groups of a polymer containing a 4-hydroxystyrene unit. In this specification, "(meth)acrylic" means acrylic and / or methacrylic.

[0091] In one embodiment of the present invention, the second polymer is represented by formula (i): ９ and R １０ represents a hydrogen atom, and R １２ represents —CO—, and R １３ It is preferable that the second polymer contains a structural unit (i) in which o and p are hydrogen atoms or methyl groups, q and r are 0, and q and r are 1 (hereinafter, this may be referred to as "second polymer C"). If the second polymer contains the structural unit (i), the low dielectric properties and heat resistance of the resulting cured film can be further improved. The second polymer containing the structural unit (i) can be synthesized, for example, by (meth)acrylic-modifying the hydroxy groups of hydroxyl-containing polyethylene.

[0092] In one embodiment of the present invention, the second polymer is represented by formula (i): ９ and R １０ represents a hydrogen atom, and R１１ represents a methylene group, and R １２ represents —CO—, and R １３ represents a hydrogen atom or a methyl group, o represents 0, and p to r represent 1; and / or a structural unit (i) ９ and R １０ one of which represents a hydrogen atom and the other represents a methyl group, and R １２ represents —CO—, and R １３ It is preferable that the second polymer contains a structural unit (i) in which o and p are hydrogen atoms or methyl groups, q and r are 0, and q and r are 1 (hereinafter, this may be referred to as "second polymer D"). If the second polymer contains the structural unit (i), the low dielectric properties and heat resistance of the resulting cured film can be further improved. The second polymer containing the structural unit (i) can be synthesized, for example, by (meth)acrylic-modifying the hydroxy groups of hydroxyl-containing polypropylene.

[0093] In one embodiment of the present invention, the second polymer is represented by formula (i): ９ and R １０ represents a hydrogen atom, and R １１ represents a phenylene group, and R １２ represents a methylene group, and R １３ It is preferable that the second polymer contains a structural unit (i) in which p represents a hydrogen atom, o represents 0, and p to r represent 1 (hereinafter, this may be referred to as "second polymer E"). If the second polymer contains the structural unit (i), the low dielectric properties and heat resistance of the resulting cured film can be further improved. The second polymer containing the structural unit (i) can be synthesized, for example, by allyl-modifying the hydroxy groups of a polymer containing a 4-hydroxystyrene unit.

[0094] In one embodiment of the present invention, the second polymer is represented by formula (i): ９ and R １０ represents a hydrogen atom, and R １２ represents a methylene group, and R １３It is preferable that the second polymer contains a structural unit (i) in which o and p are hydrogen atoms, q and r are 0, and q are 1 (hereinafter, this may be referred to as "second polymer F"). If the second polymer contains the structural unit (i), the low dielectric properties and heat resistance of the resulting cured film can be further improved. The second polymer containing the structural unit (i) can be synthesized, for example, by allyl-modifying the hydroxy groups of hydroxy-containing polyethylene.

[0095] In one embodiment of the present invention, the second polymer is represented by formula (i): ９ and R １０ represents a hydrogen atom, and R １１ represents a methylene group, and R １２ represents a methylene group, and R １３ represents a hydrogen atom, o represents 0, and p to r represent 1; and / or a structural unit (i) ９ and R １０ one of which represents a hydrogen atom and the other represents a methyl group, and R １２ represents a methylene group, and R １３ It is preferable that the second polymer contains a structural unit (i) in which o and p represent a hydrogen atom, q and r represent 0, and q represent 1 (hereinafter, this may be referred to as "second polymer G"). If the second polymer contains the structural unit (i), the low dielectric properties and heat resistance of the resulting cured film can be further improved. Note that the second polymer containing the structural unit (i) can be synthesized, for example, by allyl-modifying the hydroxy groups of hydroxyl-containing polypropylene.

[0096] In one embodiment of the present invention, the second polymer is represented by formula (i): ９ and R １０ represents a hydrogen atom, and R １１ represents a phenylene group, and R １２ Ga-CH ２ -C ６ H ４ - indicates R １３It is preferable that the second polymer contains a structural unit (i) in which p represents a hydrogen atom, o represents 0, and p to r represent 1 (hereinafter, this may be referred to as "second polymer H"). If the second polymer contains the structural unit (i), the low dielectric properties and heat resistance of the resulting cured film can be further improved. Note that the second polymer containing the structural unit (i) can be synthesized, for example, by styryl-modifying the hydroxy groups of a polymer containing a 4-hydroxystyrene unit.

[0097] In one embodiment of the present invention, the second polymer is represented by formula (i): ９ and R １０ represents a hydrogen atom, and R １２ Ga-CH ２ -C ６ H ４ - indicates R １３ It is preferable that the second polymer contains a structural unit (i) in which o and p are hydrogen atoms, q and r are 0, and q are 1 (hereinafter, this may be referred to as "second polymer I"). If the second polymer contains the structural unit (i), the low dielectric properties and heat resistance of the resulting cured film can be further improved. The second polymer containing the structural unit (i) can be synthesized, for example, by styryl-modifying the hydroxy groups of hydroxyl-containing polyethylene.

[0098] In one embodiment of the present invention, the second polymer is represented by formula (i): ９ and R １０ represents a hydrogen atom, and R １１ represents a methylene group, and R １２ Ga-CH ２ -C ６ H ４ - indicates R １３ represents a hydrogen atom, o represents 0, and p to r represent 1; and / or a structural unit (i) ９ and R １０ one of which represents a hydrogen atom and the other represents a methyl group, and R １２ Ga-CH ２ -C ６ H ４ - indicates R １３It is preferable that the second polymer contains a structural unit (i) in which o and p are hydrogen atoms, q and r are 0, and q are 1 (hereinafter, this may be referred to as "second polymer J"). If the second polymer contains the structural unit (i), the low dielectric properties and heat resistance of the resulting cured film can be further improved. The second polymer containing the structural unit (i) can be synthesized, for example, by styryl-modifying the hydroxy groups of polypropylene having hydroxy groups.

[0099] The content of the structural unit (i) in the second polymer A is preferably 50 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more, when the total structural units in the second polymer A (excluding the molecular weight modifier if a molecular weight modifier is contained) is taken as 100 mol%. The content of the structural unit (i) in the second polymer A is, for example, 99 mol% or less, and may be 95 mol% or less, when the total structural units in the second polymer A (excluding the molecular weight modifier) ​​is taken as 100 mol%.

[0100] The content of the structural unit (i) in each of the second polymers B to J is preferably 3 mol % or more, more preferably 10 mol % or more, and is preferably 30 mol % or less, and more preferably 20 mol % or less, when the total amount of all structural units in each of the second polymers B to J (excluding the molecular weight modifier, if any) is taken as 100 mol %.

[0101] [Properties of Polymer] The number average molecular weight (Mn) of the polymer is preferably 1000 or more, more preferably 1500 or more, and preferably 5000 or less, more preferably 4000 or less, and even more preferably 2500 or less. When the number average molecular weight of the polymer is at least the above lower limit, the heat resistance of the obtained cured film can be improved. On the other hand, when the number average molecular weight of the polymer is at most the above upper limit, the coating stability can be improved.

[0102] The weight average molecular weight (Mw) of the polymer is preferably 1500 or more, more preferably 2000 or more, and preferably 7000 or less, more preferably 5000 or less, and even more preferably 3000 or less. When the weight average molecular weight of the polymer is equal to or higher than the lower limit, the heat resistance of the resulting cured film can be improved. On the other hand, when the weight average molecular weight of the polymer is equal to or lower than the upper limit, the coating stability can be improved. In this specification, the weight average molecular weight is determined as a polystyrene equivalent value by gel permeation chromatography (GPC), and can be measured, for example, according to the method described in the Examples.

[0103] The molecular weight distribution (Mw / Mn) of the polymer is preferably equal to or less than 4, more preferably equal to or less than 3, and even more preferably equal to or less than 2. In this specification, the term "molecular weight distribution (Mw / Mn)" refers to the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn).

[0104] [Polymer Content] The polymer content in the ultraviolet-curable composition is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. If the polymer content in the ultraviolet-curable composition is equal to or greater than the lower limit, the low dielectric constant and heat resistance of the resulting cured film can be improved. On the other hand, if the polymer content in the ultraviolet-curable composition is equal to or less than the upper limit, the coating stability can be improved.

[0105] <Photoacid Generator> A photoacid generator is a compound that decomposes when irradiated with ultraviolet light to generate an acid. As the photoacid generator, a nonionic photoacid generator, an ionic photoacid generator, etc. can be used.

[0106] The compound that can be used as the nonionic photoacid generator is not particularly limited as long as it decomposes upon irradiation with ultraviolet light to generate an acid, and examples thereof include oxime sulfonate compounds, imide sulfonate compounds, etc. Specific examples of the oxime sulfonate compound include PAG169 (manufactured by BASF Japan Ltd., compound name: (E)-7-methoxy-3-(2,2,2-trifluoro-1-{[(trifluoromethanesulfonyl)oxy]imino}ethyl, generated acid: trifluoromethanesulfonic acid)-2H-chromen-2-one) represented by the following formula (1), and PAG121 (manufactured by BASF Japan Ltd., compound name: 2-[2-(4-methylphenylsulfonyloxyimino)thiophen-3(2H)-ylidene-2-(2-methylphenyl)acetonitrile, generated acid: trifluoromethanesulfonic acid) represented by the following formula (3). Specific examples of the imide sulfonate compound include a compound represented by the following formula (2) and a compound represented by the following formula (4). １４ and R １５ are each independently a hydrogen atom, a sulfate group, or a thiosulfate group, and may be the same or different from each other. In addition, in formula (4), Y is an oxygen atom or a sulfur atom, and R １６ is a hydrocarbon group having 1 to 20 carbon atoms which may have at least one structure selected from the group consisting of a silyl group, an alkyloxycarbonyl group, and an ether bond, or a hydrocarbon group having 1 to 20 carbon atoms which may have at least one of a carboxylic acid group and an oxycarbonyl group. Specific examples of compounds represented by formula (2) and formula (4) include NP-TM2 (manufactured by San-Apro Co., Ltd., generated acid: trifluoromethanesulfonic acid). Among these, PAG169 is preferably used as the photoacid generator from the viewpoint of further improving the insulation reliability of a resin film formed by heat treatment at low temperature using an ultraviolet-curable composition. These photoacid generators may be used alone or in combination of two or more.

[0107]

[0108] Compounds that can be used as ionic photoacid generators are not particularly limited as long as they decompose upon irradiation with ultraviolet light to generate an acid, and examples thereof include aromatic sulfonium salts, aromatic iodonium salts, aromatic diazonium salts, and aromatic ammonium salts. The anion moiety of these salts can be, for example, BF ４ － , (R ｆ ) ｎ PF ６－ｎ (R ｆ is an organic group, and n is an integer of 1 to 5.), PF ６ － , SbF ６ － , or BY ４ － (Y is a phenyl group substituted with at least two fluorine atoms or trifluoromethyl groups).

[0109] Examples of aromatic sulfonium salts include bis[4-(diphenylsulfonio)phenyl]sulfide bishexafluorophosphate, bis[4-(diphenylsulfonio)phenyl]sulfide bishexafluoroantimonate, bis[4-(diphenylsulfonio)phenyl]sulfide bistetrafluoroborate, bis[4-(diphenylsulfonio)phenyl]sulfide tetrakis(pentafluorophenyl)borate, diphenyl-4-(phenylthio)phenylsulfonium hexafluorophosphate, diphenyl-4-(phenylthio)phenylsulfonium hexafluoroantimonate, and diphenyl-4-(phenylthio)phenylsulfonium tetrafluoroborate.

[0110] Examples of aromatic iodonium salts include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium tetrakis(pentafluorophenyl)borate, bis(dodecylphenyl)iodonium hexafluorophosphate, bis(dodecylphenyl)iodonium hexafluoroantimonate, bis(dodecylphenyl)iodonium tetrafluoroborate, and bis(dodecylphenyl)iodonium tetrakis(pentafluorophenyl)borate.

[0111] Examples of aromatic diazonium salts include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrakis(pentafluorophenyl)borate.

[0112] Examples of aromatic ammonium salts include 1-benzyl-2-cyanopyridinium hexafluorophosphate and 1-benzyl-2-cyanopyridinium hexafluoroantimonate.

[0113] Specific examples of commercially available ionic photoacid generators include Irgacure 250, Irgacure 270, and Irgacure 290 (all manufactured by BASF), CPI-100P, CPI-110P, CPI-101A, CPI-110A, CPI-200K, CPI-210S, CPI-110B, CPI-310B, CPI-310FG, and VC -1S, VC-1FG, CPI-400PG, CPI-410S, CPI-410B, ES-1B, IK-1, IK-1FG (all manufactured by San-Apro Ltd.), SP-150, SP-170, SP-171, SP-056, SP-066, SP-130, SP-140, SP-601, SP-606, SP-701 (all manufactured by ADEKA Corporation). From the viewpoint of stably obtaining a cured film, the ionic photoacid generator is preferably a sulfonium salt such as Irgacure 270, Irgacure 290, CPI-100P, CPI-110P, CPI-101A, CPI-110A, CPI-200K, CPI-210S, CPI-110B, CPI-310B, CPI-310FG, VC-1S, VC-1FG, CPI-400PG, CPI-410S, CPI-410B, ES-1B, SP-150, SP-170, SP-171, SP-056, SP-066, SP-601, SP-606, or SP-701.

[0114] The content of the photoacid generator in the ultraviolet-curable composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 1.5 parts by mass or more, and is preferably 5.0 parts by mass or less, more preferably 4.0 parts by mass or less, and even more preferably 3.0 parts by mass or less, when the total amount of the monovinyl ether and divinyl ether contained in the ultraviolet-curable composition is taken as 100 parts by mass.

[0115] <Other Components> The other components that may be contained in the ultraviolet-curable composition of the present invention are not particularly limited, and examples thereof include divinyl ethers other than the divinyl ether represented by formula (B), solvents, surfactants, antioxidants, sensitizers, adhesion aids, etc. These other components may be used alone or in combination of two or more.

[0116] Examples of the sensitizer include thioxanthone compounds such as 2,4-diethylthioxanthone, 2,2-dimethoxy-1,2-diphenylethan-1-one, benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4'-bis(dimethylamino)benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 9,10-dibutoxyanthracene.

[0117] <Method for producing ultraviolet-curable composition> The ultraviolet-curable composition of the present invention can be prepared by mixing the above-mentioned components by a known method and optionally filtering them. Here, for mixing, known mixers such as a stirrer, ball mill, sand mill, bead mill, pigment disperser, crusher, ultrasonic disperser, homogenizer, planetary mixer, and Filmix can be used. In addition, for filtering the mixed liquid, a general filtration method using a filter material such as a filter can be adopted.

[0118] (Cured film) The cured film of the present invention is produced using the ultraviolet-curable composition of the present invention described above. The cured film of the present invention is produced using the ultraviolet-curable composition of the present invention, which has excellent coating stability and can impart excellent low dielectric properties and heat resistance to the cured film, and therefore has excellent uniformity in composition and film thickness, low dielectric properties, and heat resistance.

[0119] The cured film of the present invention is formed by the reaction of the monovinyl ether mixture, the divinyl ether, and the polymer in the ultraviolet-curable composition with the acid generated from the photoacid generator in the ultraviolet-curable composition upon irradiation with ultraviolet light, and curing the film. Therefore, the cured film of the present invention usually contains a reaction product of the monovinyl ether mixture, the divinyl ether represented by formula (B), and the polymer, and may also contain any other component. The cured film of the present invention is not particularly limited, and can be formed, for example, by forming a coating film using the ultraviolet-curable composition of the present invention and irradiating the coating film with ultraviolet light.

[0120] The method for applying the ultraviolet-curable composition is not particularly limited, and various methods can be used, such as spray coating, spin coating, roll coating, die coating, doctor blade method, rotary coating, bar coating, screen printing, inkjet method, etc. Here, while the inkjet method is prone to clogging of the discharge part, the ultraviolet-curable composition of the present invention has excellent coating stability and can effectively prevent clogging of the discharge part, and therefore can be particularly suitably used in the inkjet method.

[0121] (Organic EL display device) The organic EL display device of the present invention comprises a support substrate, an organic EL element disposed on the support substrate, and a sealing layer covering the organic EL element. In the organic EL display device of the present invention, the sealing layer comprises the cured film of the present invention described above. The organic EL display device of the present invention has excellent performance because it comprises a sealing layer comprising the cured film of the present invention, which has excellent uniformity in composition and film thickness, low dielectric properties, and heat resistance. The organic EL display device of the present invention may further comprise a transparent substrate and a passivation layer, in addition to the support substrate, organic EL element, and sealing layer.

[0122] Hereinafter, examples of the organic EL display device of the present invention will be described with reference to FIG. 1, but the organic EL display device of the present invention is not limited to these.

[0123] Fig. 1 is a schematic cross-sectional view showing an example of an organic EL display device of the present invention. The organic EL display device 1 shown in Fig. 1 includes a support substrate 2, a transparent substrate 3 facing the support substrate 2 with a gap therebetween, an organic EL element 4 disposed on the surface of the support substrate 2 facing the transparent substrate 3, and a sealing layer 5 covering the organic EL element 4. The organic EL display device 1 also includes a passivation layer 6 covering the surface of the support substrate 2 facing the transparent substrate 3 and the organic EL element 4.

[0124] The support substrate 2 can be made of, for example, a resin material or glass, but there is no particular limitation on the material of the support substrate 2. The support substrate 2 may be in the form of a plate or a film.

[0125] The transparent substrate 3 can be made of a light-transmitting material. The transparent substrate 3 is made of, for example, glass or transparent resin, but the material of the support substrate 2 is not particularly limited. The transparent substrate 3 may be in the form of a plate or a film.

[0126] The organic EL element 4 is also called an organic light-emitting diode. The organic EL element 4 includes, for example, a pair of electrodes and an organic light-emitting layer between the electrodes. The organic EL element 4 can be fabricated by, for example, a coating method such as an inkjet method.

[0127] The sealing layer 5 is made of the cured film of the present invention described above. That is, the sealing layer 5 is made using the ultraviolet-curable composition of the present invention described above.

[0128] The passivation layer 6 is preferably made of silicon nitride or silicon oxide and can be formed, for example, by evaporation.

[0129] The organic EL display device of the present invention is not particularly limited, and can be manufactured by a conventionally known method.

[0130] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples. In the following description, "%" and "parts" representing amounts are based on mass unless otherwise specified. In the examples and comparative examples, various measurements and evaluations were carried out by the following methods.

[0131] <Number Average Molecular Weight, Weight Average Molecular Weight, and Molecular Weight Distribution> The weight average molecular weight (Mw) and number average molecular weight (Mn) of the hydrogenated modified ring-opening polymers obtained in the Examples and Comparative Examples were measured using gel permeation chromatography, and the molecular weight distribution (Mw / Mn) was calculated. Specifically, a gel permeation chromatograph (HLC-8220, manufactured by Tosoh Corporation) was used with tetrahydrofuran as a developing solvent to determine the weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer in terms of standard polystyrene. The molecular weight distribution (Mw / Mn) was then calculated.

[0132] <Viscosity of Monovinyl Ether Mixture> The viscosity of the monovinyl ether mixture was measured at 25°C using an E-type viscometer (TVE-22L model, manufactured by Toki Sangyo Co., Ltd.).

[0133] <Low Dielectric Properties> The ultraviolet-curable compositions prepared in the examples and comparative examples were applied to aluminum foil with a thickness of 30 μm using a bar coater to form a coating film. The resulting coating film was then irradiated with 700 mJ / cm using a high-pressure mercury lamp (g-hi mixed rays, g-ray = 436 nm, h-ray = 405 nm, i-ray = 365 nm). ２ The aluminum foil sample was cured by exposure to an irradiation dose of 100 μm, and an aluminum foil sample was obtained on which a cured film of 30 μm in thickness was formed. This sample was cut to a size of 60 mm x 60 mm, and electrodes were formed on the cured film using a conductive paste. The aluminum foil sample with electrodes was then used to measure the relative dielectric constant (Dk) of the cured film at 100 kHz with an LCR meter (HP-4284A, manufactured by Agilent Technologies). The measured relative dielectric constant (Dk) value was evaluated according to the following criteria. The smaller the relative dielectric constant (Dk), the better the cured film's low dielectric properties. A: Dk less than 3.0 B: Dk 3.0 or more but less than 3.5 C: Dk 3.5 or more

[0134] <Heat Resistance> The ultraviolet-curable compositions prepared in the Examples and Comparative Examples were applied to a silicon wafer using a spin coater to form a coating film. The resulting coating film was then irradiated with 700 mJ / cm using a high-pressure mercury lamp (g-hi mixed rays). ２ The cured film was cured by exposure to an irradiation dose of 10 μm, to obtain a silicon wafer sample on which a cured film having a thickness of 10 μm was formed. The cured film was then scraped off from the silicon wafer. The scraped-off cured film was evaluated for its weight loss rate at 110°C (measurement conditions: 40°C to 400°C, heating rate 10°C / min) relative to 40°C using TG / DTA (thermogravimetric differential thermal analyzer STA7200, manufactured by Hitachi High-Tech Science) according to the following criteria. Note that a smaller weight loss rate indicates a more excellent heat resistance of the cured film. A: Weight loss rate less than -0.5% B: Weight loss rate -0.5% or more but less than -0.7% C: Weight loss rate -0.7% or more

[0135] <Coating Stability> The viscosity of the ultraviolet-curable compositions prepared in the examples and comparative examples was measured at 25°C using an E-type viscometer (TVE-22L model manufactured by Toki Sangyo Co., Ltd.). The measured viscosity values ​​were evaluated according to the following criteria. Note that the lower the viscosity, the better the coating stability. A: Viscosity less than 35 cP B: Viscosity 35 cP or more but less than 50 cP C: Viscosity 50 cP or more

[0136] Example 1 Preparation of Modified Hydrogenated Ring-Opening Polymer Ring-Opening Polymer Step 100 parts of a monomer mixture consisting of 15 mol % of 2-norbornene-5-methanol (hereinafter abbreviated as "NBMOH") and 85 mol % of ethylidenetetracyclododecene (hereinafter abbreviated as "ETD"), 15.9 parts of 1-decene as a molecular weight modifier, 0.1 part of (1,3-dimesitylimidazolin-2-ylidene)(tricyclohexylphosphine)benzylidene ruthenium dichloride (synthesized by the method described in Org. Lett., Vol. 1, p. 953, 1999) as a ring-opening polymerization catalyst, and 280 parts of toluene as a solvent were charged into a nitrogen-purged glass pressure-resistant reactor and reacted at 40°C for 3 hours with stirring to obtain a polymerization reaction liquid containing a ring-opening polymer.

[0137] [Hydrogenation Step] The polymerization reaction solution obtained in the ring-opening polymerization step was placed in an autoclave and stirred at 130° C. under a hydrogen pressure of 10 MPa for 5 hours to carry out a hydrogenation reaction, thereby obtaining a toluene solution of a hydrogenated ring-opening polymer.

[0138] [Modification Step] A three-necked flask equipped with a stirring blade and a thermometer was purged with nitrogen, and 100 parts of a toluene solution of the hydrogenated ring-opening polymer obtained in the hydrogenation step, 67 parts of triethylamine as a modification reaction catalyst, and 270 parts of toluene as a solvent were charged. The reaction solution was cooled to 0 ° C. in an ice bath. While maintaining the temperature of the reaction solution at 10 ° C. or below, 52 parts of methacrylic acid chloride as a modifying agent was added dropwise and stirred for 2 hours. The reaction solution was then warmed to room temperature and stirred for 12 hours. Next, 200 parts of tetrahydrofuran as a solvent was added to the reaction solution, and the mixture was cooled to 0 ° C. 0.5 parts by mass of methanol relative to the methacrylic acid chloride was added while maintaining the temperature of the reaction solution at 10 ° C. or below. The mixture was then heated to room temperature and stirred for 1 hour at 0 ° C., and then further stirred for 1 hour. After stirring, the precipitated salt was filtered off from the reaction solution, and the resulting filtrate was added dropwise to 8,000 parts of 2-propanol to form a precipitate, which was then collected by filtration. The recovered precipitate was washed three times with 2-propanol and then dried under reduced pressure at 50°C to obtain a modified product of the hydrogenated ring-opening polymer (hereinafter referred to as "modified hydrogenated ring-opening polymer"). GPC measurement of the modified hydrogenated ring-opening polymer showed that the number average molecular weight was 1660, the weight average molecular weight was 2700, and the molecular weight distribution was 1.6. １ H-NMR measurement confirmed that the methacryloyl modification rate of the hydrogenated ring-opening polymer was 100%, and the content of methacryloyl-modified NBMOH in the hydrogenated ring-opening polymer was 15 mol %. Furthermore, it was confirmed that the hydrogenated ring-opening polymer was a polymer containing 15 mol % of structural units represented by the following formula (I-1) and 85 mol % of structural units represented by the following formula (II-1).

[0139]

[0140] <Preparation of UV-Curable Composition> 25 parts of the modified hydrogenated ring-opening polymer obtained above, 50 parts of cyclohexanedimethanol divinyl ether (manufactured by Nippon Carbide Corporation, "CHDVE"), 25 parts of a monovinyl ether mixture (manufactured by New Japan Chemical Co., Ltd., "Rikavinyl C", viscosity: 7 mPa·s), and 1.5 parts of Irgacure PAG-169 (manufactured by BASF) as a photoacid generator (an amount equivalent to 2.0 parts when the total amount of monovinyl ether and divinyl ether is taken as 100 parts) were mixed to obtain a mixed solution. The mixed solution was then filtered through a polytetrafluoroethylene filter with a pore size of 0.45 μm, and the filtrate was recovered to prepare a UV-curable composition. Various evaluations were performed using the obtained UV-curable composition. The results are shown in Table 1. The monovinyl ether mixture used above was a mixture of 25 parts of the monovinyl ether represented by formula (A), R Ａ The composition is as follows: monovinyl ether with carbon numbers of "8" is 2.7%, monovinyl ether with carbon numbers of "10", monovinyl ether with carbon numbers of "12", monovinyl ether with carbon numbers of "14", monovinyl ether with carbon numbers of "16", monovinyl ether with carbon numbers of "18", and monovinyl ether with carbon numbers of "18".

[0141] (Example 2) In preparing the ultraviolet-curable composition, the amount of cyclohexanedimethanol divinyl ether used was changed from 50 parts to 37.5 parts, and the amount of the monovinyl ether mixture used was changed from 25 parts to 37.5 parts, except that the procedures, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0142] (Example 3) In preparing the ultraviolet-curable composition, the amount of cyclohexanedimethanol divinyl ether used was changed from 50 parts to 25 parts, and the amount of the monovinyl ether mixture used was changed from 25 parts to 50 parts, except that the procedures, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0143] (Example 4) In preparing an ultraviolet-curable composition, various operations, measurements, and evaluations were carried out in the same manner as in Example 2, except that 37.5 parts of cyclohexanedimethanol divinyl ether was changed to 18.75 parts of cyclohexanedimethanol divinyl ether and 18.75 parts of nonanediol divinyl ether (manufactured by Nippon Carbide Industries Co., Ltd., "NDVE"). The results are shown in Table 1.

[0144] (Example 5) In preparing the ultraviolet-curable composition, various operations, measurements, and evaluations were carried out in the same manner as in Example 2, except that 25 parts of the modified hydrogenated ring-opening polymer was replaced with 25 parts of polybutadiene (manufactured by Nippon Soda Co., Ltd., "NISSO-PB B-2000", liquid polybutadiene, number average molecular weight: 2100). The results are shown in Table 1.

[0145] (Comparative Example 1) In the preparation of an ultraviolet-curable composition, various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that the modified ring-opening polymer hydrogenated product was not used and the amount of the monovinyl ether mixture used was changed from 25 parts to 50 parts. The results are shown in Table 1.

[0146] (Comparative Example 2) In preparing an ultraviolet-curable composition, various operations, measurements, and evaluations were carried out in the same manner as in Example 2, except that 37.5 parts of the monovinyl ether mixture was changed to 37.5 parts of octadecyl vinyl ether ("ODVE", manufactured by Nippon Carbide Industries Co., Ltd., solid at 25°C). The results are shown in Table 1.

[0147]

[0148] According to the present invention, there is provided an ultraviolet-curable composition that has excellent coating stability and can impart excellent low dielectric properties and heat resistance to a cured film. Further, according to the present invention, there is provided a cured film obtained using the ultraviolet-curable composition. Further, according to the present invention, there is provided an organic EL display device including the cured film.

[0149] REFERENCE SIGNS LIST 1 Organic EL display device 2 Support substrate 3 Transparent substrate 4 Organic EL element 5 Sealing layer 6 Passivation layer

Claims

1. The following formula (A): CH ２ =CH-O-R Ａ (A) (In formula (A), R Ａ represents an alkyl group having 8 to 18 carbon atoms, and a mixture containing two or more monovinyl ethers represented by the following formula (B): ２ =CH-O-R Ｂ —O—CH═CH ２ (B) (In formula (B), R Ｂ represents a divalent hydrocarbon group having 2 to 20 carbon atoms, a polymer including a main chain made of hydrocarbon and a side chain having a polymerizable functional group, and a photoacid generator.

2. The ultraviolet-curable composition according to claim 1, wherein the number-average molecular weight of the polymer is 5,000 or less.

3. The ultraviolet-curable composition according to claim 2, wherein the hydrocarbon of the main chain of the polymer contains an alicyclic structure.

4. The ultraviolet-curable composition according to claim 3, wherein the polymer comprises a structural unit (I) represented by the following formula (I) and a structural unit (II) represented by the following formula (II): (In formula (I), R １ ~R ３ each independently represents a hydrogen atom, an alkyl group, or an aromatic ring group; R １ ~R ３ may be bonded to form a ring, and R ４ represents a hydrogen atom or an alkyl group, X represents an alkylene group having 1 to 10 carbon atoms, and m represents 0, 1, or 2; and in formula (II), R ５ ~R ８ each independently represents a hydrogen atom, an alkyl group, or an aromatic ring group; R ５ ~R ８ may be bonded to form a ring, and n represents 0, 1 or 2.

5. The ultraviolet-curable composition according to claim 2, wherein the hydrocarbon of the main chain of the polymer has a linear structure.

6. The ultraviolet-curable composition according to claim 5, wherein the polymer contains a structural unit (i) represented by the following formula (i): (In formula (i), R ９ and R １０ each independently represents a hydrogen atom or a methyl group, R １１ represents a methylene group or a phenylene group, and R １２ is —CO—, a methylene group or —CH ２ -C ６ H ４ - indicates R １３ represents a hydrogen atom or an alkyl group, and o to r each independently represent 0 or 1, provided that when o is 1, p represents 1.

7. The ultraviolet-curable composition according to claim 1, wherein the viscosity of the mixture is 20 mPa·s or less.

8. The mixture may contain the R Ａ a monovinyl ether A having 8 to 12 carbon atoms, and Ａ and a monovinyl ether B having 13 or more and 18 or less carbon atoms.

9. The ultraviolet-curable composition according to claim 8, wherein the total content of the monovinyl ether A in the mixture is 50.5% by mass or more and 80.0% by mass or less, and the total content of the monovinyl ether B in the mixture is 20.0% by mass or more and 49.5% by mass or less.

10. The ultraviolet-curable composition of claim 1, wherein the mixture comprises monovinyl ether C that is liquid at 25°C and monovinyl ether D that is solid at 25°C.

11. The ultraviolet-curable composition according to claim 10, wherein the total content of monovinyl ether C in the mixture is 69.4% by mass or more and 99.0% by mass or less, and the total content of monovinyl ether D in the mixture is 1.0% by mass or more and 30.6% by mass or less.

12. The above R Ｂ 2. The ultraviolet-curable composition according to claim 1, wherein the content of the divinyl ether in which the hydrocarbon group contains an alicyclic structure is 100 parts by mass or more relative to 100 parts by mass of the polymer.

13. The ultraviolet-curable composition according to claim 1, wherein the content of the mixture is 140 parts by mass or more, based on 100 parts by mass of the polymer.

14. A cured film obtained using the ultraviolet-curable composition according to any one of claims 1 to 13.

15. An organic EL display device comprising a support substrate, an organic EL element disposed on the support substrate, and a sealing layer covering the organic EL element, wherein the sealing layer is made of the cured film according to claim 14.

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