CURABLE COMPOSITION, CURED FILM, METHOD OF PRODUCING CURED FILM, ELEMENT, AND DISPLAY DEVICE

Abstract

Provided are a curable composition and an application thereof. The curable composition contains: a compound A having a polymerizable group (a) and an oxyfluoroalkylene group; a polymerization initiator; and a compound B having a polymerizable group different from the polymerizable group (a). The polymerizable group (a) in the compound A is at least one selected from the group consisting of a vinylphenyl group, a vinylphenyloxy group, a vinylbenzyloxy group, a vinyloxy group, a vinyloxycarbonyl group, a vinylamino group, a vinylaminocarbonyl group, a vinylthio group, an allyloxy group, an allyloxycarbonyl group, an allylamino group, an allylaminocarbonyl group, an allylthio group, an epoxy group, and an epoxycycloalkyl group.

Claims

1. A curable composition comprising: a compound A having a polymerizable group (a) and an oxyfluoroalkylene group; a polymerization initiator; and a compound B having a polymerizable group different from the polymerizable group (a), wherein the polymerizable group (a) in the compound A is at least one selected from the group consisting of a vinylphenyl group, a vinylphenyloxy group, a vinylbenzyloxy group, a vinyloxy group, a vinyloxycarbonyl group, a vinylamino group, a vinylaminocarbonyl group, a vinylthio group, an allyloxy group, an allyloxycarbonyl group, an allylamino group, an allylaminocarbonyl group, an allylthio group, an epoxy group, and an epoxycycloalkyl group.

2. The curable composition according to claim 1, wherein a content of the compound A is 40% by mass to 90% by mass with respect to a total amount of the curable composition.

3. The curable composition according to claim 1, wherein a molecular weight of the compound A is 500 to 5000.

4. The curable composition according to claim 1, wherein the compound B is at least one selected from the group consisting of a compound B1 having a polymerizable group different from the polymerizable group (a) and having an oxyfluoroalkylene group, a compound B2 having two or more polymerizable groups and having no oxyfluoroalkylene group, and a compound B3 having one polymerizable group and having no oxyfluoroalkylene group.

5. The curable composition according to claim 1, wherein the polymerizable group in the compound B is at least one selected from the group consisting of a (meth)acryloyl group and a maleimide group.

6. The curable composition according to claim 1, wherein the compound A is a compound represented by the following Formula (1):
M.sup.1.sub.r1-Y.sup.1-Rf.sup.1-(OX).sub.m—O-Rf.sup.2-Y.sup.2-M.sup.2.sub.r2   Formula (1) wherein, in Formula (1): each of M.sup.1 and M.sup.2 independently represents the polymerizable group (a); each of r1 and r2 independently represents an integer of 1 or more; Y.sup.1 represents a (r1+1)-valent linking group having no fluorine atom; Y.sup.2 represents a (r2+1)-valent linking group having no fluorine atom; Rf.sup.1 represents a fluoroalkylene group in which a fluorine atom is bonded to a carbon atom bonded to Y.sup.1; Rf.sup.2 represents a fluoroalkylene group in which a fluorine atom is bonded to a carbon atom bonded to Y.sup.2; each X independently represents a fluoroalkylene group; and m represents an integer of 1 or more.

7. The curable composition according to claim 6, wherein: in Formula (1), (OX).sub.m includes a structure in which continuous (OX) is represented by the following Formula (2), and m represents an integer of 2 or more:
—(OX.sup.1-OX.sup.2).sub.a—  Formula (2) wherein, in Formula (2): X.sup.1 represents a fluoroalkylene group having 1 to 6 carbon atoms; X.sup.2 represents a fluoroalkylene group having 1 to 6 carbon atoms and is different from X.sup.1; and a represents an integer of 1 or more, and satisfies 2≤(2×a)≤m.

8. The curable composition according to claim 6, wherein in Formula (1), (OX).sub.m includes (OC.sub.4F.sub.6).sub.b, and b is an integer of 1 or more.

9. The curable composition according to claim 6, wherein, in Formula (1): (OX).sub.m includes (OC.sub.2F.sub.4).sub.c and (OCF.sub.2).sub.d; each of c and d independently represents an integer of 1 or more; and d/c is 0.8 or more.

10. The curable composition according to claim 6, wherein in Formula (1), (OX).sub.m includes (OC.sub.3F.sub.6).sub.e, and e is an integer of 1 or more.

11. The curable composition according to claim 6, wherein in Formula (1), each of Y.sup.1 and Y.sup.2 independently represents a single bond or represents a linking group containing at least one selected from the group consisting of an alkylene group, an arylene group, —C(═O)—, —O—, —S—, —NH—, —N<, —SiH.sub.2—, >SiH—, and >Si<.

12. The curable composition according to claim 1, wherein a content of an organic solvent is 1% by mass or less with respect to a total amount of the curable composition.

13. The curable composition according to claim 1, further comprising a silane coupling agent.

14. A cured film, which is a cured product of the curable composition according to claim 1.

15. A method of producing a cured film, the method comprising: applying the curable composition according to claim 1 onto a substrate; and irradiating the curable composition with an active energy ray.

16. An element comprising the cured film according to claim 14.

17. The element according to claim 16, wherein the element is used for a sensor.

18. The element according to claim 16, wherein the element is used for optics.

19. A display device comprising an optical element, which is the element according to claim 18.

Description

EXAMPLES

[0293] Hereinafter, the disclosure will be described more specifically with reference to Examples, but the disclosure is not limited to the following Examples as long as the gist of the disclosure is not exceeded.

[0294] Compounds A1 to A7, and compounds B11 and B12 used in Examples and Comparative Examples were synthesized.

Synthesis of Compound A1

Example 1-1

[0295] A compound 1-1 was obtained according to the method described in Example 1-1 of Examples of WO2013-121984.

Compound 1-1

[0296]
CF.sub.2=CFO—CF.sub.2CF.sub.2CF.sub.2CH.sub.2OH

Example 1-2

[0297] In a 100 mL stainless steel reactor, 100 g of the compound 1-1 obtained in Example 1-1 was placed, followed by stirring at 175° C. for 200 hours. The resulting organic phase was concentrated to obtain 62 g of a compound 1-2.

##STR00009##

Example 1-3

[0298] To a 200 mL four-necked flask, 10 g of the compound 1-2 obtained in Example 1-2, 20 mL of ASAHIKLIN AC-6000 (fluorine-based solvent, manufactured by AGC Inc.), and 5.9 g of cesium carbonate were added, followed by stirring at 60° C. for 30 minutes. Thereafter, the temperature of the reaction system was cooled to room temperature, and 2.7 g of chloromethylstyrene (meta/para mixture: manufactured by Tokyo Chemical Industry Co., Ltd.) was added thereto, followed by stirring at 70° C. for 12 hours. Thereafter, methanol was added to the mixture, and an organic layer was then separated. The resulting organic layer was further washed, and concentrated. The resulting crude product was purified by silica gel column chromatography to obtain 8.9 g of a compound A1.

##STR00010##

Synthesis of Compound A2

Example 2-1

[0299] A compound A2 was obtained in the same manner as in Example 1-3 except that FOMBLIN D2 (manufactured by Solvay Corporation) was used in place of the compound 1-2. The average value of the numbers of repetitions c+d was 15, and d/c≈1 was set.

##STR00011##

Synthesis of Compound A3

Example 3-1

[0300] A compound A3 was obtained in the same manner as in Example 1-3 except that FLUOROLINK D4000 (manufactured by Solvay Corporation) was used in place of the compound 1-2. The average value of the numbers of repetitions c+d was 44, and d/c≈1 was set.

##STR00012##

Synthesis of Compound A4

Example 4-1

[0301] A compound 4-1 was synthesized in the same manner as in Synthesis Examples 1 to 4 of Japanese Patent No. 6024816.

Compound 4-1

[0302]
CH.sub.3OCOCF.sub.2—(OCF.sub.2).sub.d—(OCF.sub.2CF.sub.2).sub.c—OCF.sub.2CO.sub.2CH.sub.3

[0303] In the Formula, d is an average of 42, and c is an average of 10.

Example 4-2

[0304] To a 500 mL three-necked recovery flask, 20 g of the compound 4-1 obtained in Synthesis Example 4-1, 20 mL of THF, 20 mL of ASAHIKLIN AC-2000 (fluorine-based solvent, manufactured by AGC Inc., hereinafter referred to as “AC-2000”), and 1.2 g of sodium borohydride were added, followed by stirring. 0.5 mL of methanol was added to the mixture, followed by stirring overnight at room temperature. Thereafter, a 1 mol/L aqueous hydrochloric acid solution and Asahikrine AE-3000 (1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, manufactured by AGC Inc., hereinafter referred to as “AE-3000”) were added to the mixture, and the solution was separated. The resulting organic layer was concentrated. The resulting crude product was purified by silica gel column chromatography to obtain 19 g of a compound 4-2. The average value of the numbers of repetitions c+d was 52, and d/c≈4 was set.

Compound 4-2

[0305]
HOCH.sub.2CF.sub.2—(OCF.sub.2).sub.d—(OCF.sub.2CF.sub.2).sub.c—OCF.sub.2CH.sub.2OH

Example 4-3

[0306] A compound A4 was obtained in the same manner as in Example 1-3 except that the compound 4-2 obtained in Example 4-2 was used in place of the compound 1-2. The average value of the numbers of repetitions c+d was 52, and d/c≈4 was set.

##STR00013##

Synthesis of Compound A5

Example 5-1

[0307] In a 500 mL recovery flask, 10 g of the compound 1-2 obtained in Example 1-2 and 2.4 g of potassium carbonate were placed, followed by stirring at 120° C. 84 g of the compound 1-1 was added to the mixture, followed by stirring at 120° C. for 2 hours. The temperature was returned to 25° C. 85 g of AC-2000 and 85 g of hydrochloric acid were added to the mixture, and the solution was separated. The organic layer was concentrated. The resulting crude reaction solution was purified by column chromatography to obtain 45 g of a compound 5-1. The average value of the numbers of repetitions m+n was 14.

##STR00014##

Example 5-2

[0308] To a 50 mL recovery flask to which a reflux condenser was connected, 20 g of the compound 5-1 obtained in Example 5-1, 6.2 g of a sodium fluoride powder, 20 g of AC-2000, and 10 g of CF.sub.3CF.sub.2CF.sub.2OCF(CF.sub.3)COF were added. Under a nitrogen atmosphere, the mixture was stirred at 50° C. for 24 hours. After cooling to room temperature, the sodium fluoride powder was removed with a pressure filtration machine. Excess CF.sub.3CF.sub.2CF.sub.2OCF(CF.sub.3)COF and AC-2000 were distilled off under reduced pressure to obtain 22.5 g of a compound 5-2. The average value of the numbers of repetitions m+n was 14.

##STR00015##

Example 5-3

[0309] In a 500 mL nickel reactor, 250 mL of ClCF.sub.2CFClCF.sub.2OCF.sub.2CF.sub.2Cl (hereinafter referred to as “CFE-419”) was placed, followed by bubbling with nitrogen gas. After the oxygen gas concentration was sufficiently decreased, bubbling with 20 vol % fluorine gas diluted with nitrogen gas was performed for 1 hour. A CFE-419 solution (concentration: 10%, compound 1E: 20 g) of the compound 5-2 obtained in Example 5-2 was charged over 3 hours. The ratio of the introduction rate (mol/hour) of fluorine gas to the introduction rate (mol/hour) of hydrogen atoms in the compound 1E was controlled to be 2:1. After the completion of the charge of the compound 5-2, a CFE-419 solution (concentration: 0.1%, benzene: 0.1 g) of benzene was intermittently charged. After the completion of the charge of benzene, bubbling with fluorine gas was performed for 1 hour, and finally the inside of the reactor was sufficiently replaced with nitrogen gas. The solvent was distilled off to obtain 21 g of a compound 5-3. The average value of the numbers of repetitions m+n was 14.

##STR00016##

Example 5-4

[0310] In a 50 mL recovery flask, 20 g of the compound 5-3 obtained in Example 5-3, 1.8 g of sodium fluoride, and 20 mL of AC-2000 were placed in the recovery flask, followed by stirring in an ice bath. 1.4 g of methanol was placed, followed by stirring at 25° C. for 1 hour. The mixture was subjected to filtration, and the filtrate was then purified by column chromatography. 15 g of a compound 5-4 was obtained. The average value of the numbers of repetitions m+n was 14.

##STR00017##

Example 5-5

[0311] To a 500 mL three-necked recovery flask, 14 g of the compound 5-4 obtained in Synthesis Example 5-4, 20 mL of THF, 20 mL of AC-2000, and 1.0 g of sodium borohydride were added, followed by stirring. 0.4 mL of methanol was added to the mixture, followed by stirring overnight at room temperature. Thereafter, a 1 mol/L aqueous hydrochloric acid solution and AE-3000 were added to the mixture, and the solution was separated. The resulting organic layer was concentrated. The resulting crude product was purified by silica gel column chromatography to obtain 14 g of a compound 5-5. The average value of the numbers of repetitions m+n was 14.

##STR00018##

Example 5-6

[0312] A compound A5 was obtained in the same manner as in Example 1-3 except that the compound 5-5 was used in place of the compound 1-2. The average value of the numbers of repetitions m+n was 14.

##STR00019##

Synthesis of Compound A6

Example 6-1

[0313] A compound 6-1 was obtained according to the method described in Example 1 of WO2008/026707, and then reacted with methanol to obtain a compound 6-2.

Compound 6-1

[0314]
CF.sub.3CF.sub.2OCF.sub.2CF.sub.2OCF.sub.2C(O)F

Compound 6-2

[0315]
CF.sub.3CF.sub.2OCF.sub.2CF.sub.2OCF.sub.2C(O)OCH.sub.3

Example 6-2

[0316] 3.2 g of sodium borohydride and 200 mL of AC-2000 were added to a 500 mL three-necked recovery flask, followed by stirring under ice cooling. Then, 20 g of the compound 6-2 obtained in Example 6-1 and 2.6 g of methanol were slowly added to the mixture followed by stirring overnight at room temperature after the completion of the addition. Thereafter, a 1 mol/L aqueous hydrochloric acid solution and AC-2000 were added to the mixture, and the solution was separated. The resulting organic layer was concentrated. The resulting crude product was purified by silica gel column chromatography to obtain 18.5 g of a compound 6-3.

##STR00020##

Example 6-3

[0317] A compound A6 was obtained in the same manner as in Example 1-3 except that the compound 6-3 was used in place of the compound 1-2.

##STR00021##

Synthesis of Compound A7

Example 7-1

[0318] A compound 7-1 was obtained in the same manner as in Example 6-1 except that CF.sub.3CF.sub.2CF.sub.2—O—[CF(CF.sub.3)CF.sub.2—O].sub.2—CF(CF.sub.3)COF was used in place of the compound 6-1.

Compound 7-1

[0319]
CF.sub.3CF.sub.2CF.sub.2—O—[CF(CF.sub.3)CF.sub.2—O].sub.2—CF(CF.sub.3)COOCH.sub.3

Example 7-2

[0320] A compound 7-2 was obtained in the same manner as in Example 6-2 except that the compound 7-1 was used in place of the compound 6-2.

Compound 7-2

[0321]
CF.sub.3CF.sub.2CF.sub.2—O—[CF(CF.sub.3)CF.sub.2—O].sub.2—CF(CF.sub.3)CH.sub.2OH

Example 7-3

[0322] A compound A7 was obtained in the same manner as in Example 1-3 except that the compound 7-2 was used in place of the compound 1-2.

##STR00022##

Synthesis of Compound B11

Example 11-1

[0323] To a 300 mL four-necked flask, 10 g of the compound 1-2 obtained in Example 1-2, 45 mL of AE-3000 (manufactured by AGC Inc.), 4 g of pyridine, 11 g of sodium hydrogen carbonate, and 9 g of ion-exchanged water were added, followed by stirring under ice cooling. Thereafter, 14 g of 3-chloropropionic acid chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) was slowly added to the mixture. After the completion of the addition, the mixture was stirred for 30 minutes while being cooled, and then stirred at room temperature for 1 hour and 30 minutes. Thereafter, an aqueous potassium carbonate solution was added to the mixture, and the solution was separated. Then, the resulting organic layer was concentrated. The crude liquid obtained by concentration was added to a 300 mL four-necked flask. 104 g of triethylamine and 0.28 g of hydroquinone were sequentially added to the crude liquid, followed by stirring at 55° C. for 1.5 hours. Thereafter, the mixture was sequentially washed with 1 mol/L hydrochloric acid water, saline water, and sodium bicarbonate water. The resulting organic phase was concentrated and purified by silica gel column chromatography to obtain 8.9 g of a compound B11.

##STR00023##

Synthesis of Compound B12

Example 12-1

[0324] A compound B12 was obtained in the same manner as in Example 11-1 except that FOMBLIN D2 (manufactured by Solvay Corporation) was used in place of the compound 1-2. The average value of the numbers of repetitions c1+d1 was 15, and d1/c1≈1 was set.

##STR00024##

[0325] Details of the polymerization initiator, the compound B21, the compound B31, and the silane coupling agent used in Examples 1 to 17 are as follows. [0326] Polymerization initiator . . . 2-hydroxy-2-methyl-1-phenylpropanone (product name “OMNIRAD 1173”, manufactured by IGM Resins B.V.) [0327] Compound B21 . . . 1,6-hexanediol diacrylate (product name “B2936”, manufactured by Tokyo Chemical Industry Co., Ltd.) [0328] Compound B31 . . . isobornyl acrylate (product name “I0638”, manufactured by Tokyo Chemical Industry Co., Ltd.) [0329] Silane coupling agent . . . 3-acryloxypropyltrimethoxysilane (product name “KBM-5103”, manufactured by Shin-Etsu Chemical Co., Ltd.)

Examples 1 to 17

[0330] Components shown in Tables 1 and 2 were mixed so as to have contents (% by mass) shown in Tables 1 and 2, to prepare curable compositions. In Table 1, “-” was described for components not contained.

[0331] The viscosity and curability of each of the curable compositions obtained in Examples 1 to 17 were evaluated. A cured film obtained by curing the curable composition obtained in each of Examples and Comparative Examples was evaluated for a dielectric constant and adhesion. The evaluation method is as follows.

Viscosity

[0332] A dynamic viscoelasticity at a shear rate of 10 s.sup.−1 was measured at 25° C. using a dynamic viscoelasticity measuring device (product name “PHYSICAMCR 301”, manufactured by Anton Paar GmbH). The evaluation criteria are as follows. A to C are at a level of no practical problem.

[0333] A: 25 mPa.Math.s or less

[0334] B: more than 25 mPa.Math.s and 40 mPa.Math.s or less

[0335] C: more than 40 mPa.Math.s and 50 mPa.Math.s or less

[0336] D: more than 50 mPa.Math.s

Curability

[0337] The curable composition was applied onto a silicon substrate by spin coating, and irradiated with an ultraviolet ray at an exposure amount of 3000 mJ/cm.sup.2 from a high-pressure mercury lamp under a nitrogen atmosphere. In a case in which the curable composition was not cured by irradiation with the ultraviolet ray, the curable composition was subjected to a heat treatment at 100° C. for 5 minutes after the irradiation with the ultraviolet ray. In a case in which the curable composition was not cured by the heat treatment for 5 minutes, the curable composition was subjected to a heat treatment at 100° C. for another 55 minutes. Whether or not the curable composition was cured was determined based on a peak derived from a polymerizable group in an infrared absorption spectrum obtained using an infrared spectrophotometer (product name: MAGNA 760, manufactured by Nikolet Company). In the measurement, an incident angle was fixed to 6.5 degrees, and a data interval was set to about 0.5 cm.sup.−1. The curable composition was scanned 64 times, and the measured data were averaged. In a case in which the peak derived from the polymerizable group disappeared after the treatment, or in a case in which the height of the peak derived from the polymerizable group was reduced to 30% or less as compared with that before irradiation with the ultraviolet ray, the resin composition was determined to be cured. The evaluation criteria are as follows. A to C are at a level of no practical problem.

[0338] A: The curable composition was cured only by irradiation with an ultraviolet ray at an exposure amount of 3000 mJ/cm.sup.2.

[0339] B: The curable composition was cured in a case in which the curable composition was irradiated with an ultraviolet ray at an exposure amount of 3000 mJ/cm.sup.2, and then subjected to a heat treatment at 100° C. for 5 minutes.

[0340] C: The curable composition was cured in a case in which the curable composition was irradiated with an ultraviolet ray at an exposure amount of 3000 mJ/cm.sup.2, and then subjected to a heat treatment at 100° C. for 60 minutes.

[0341] D: The curable composition was not cured even in a case in which the curable composition was irradiated with an ultraviolet ray at an exposure amount of 3000 mJ/cm.sup.2, and then subjected to a heat treatment at 100° C. for 60 minutes.

Dielectric Constant

[0342] The curable composition was applied onto a P-type silicon substrate by spin coating, irradiated with an ultraviolet ray at an exposure amount of 3000 mJ/cm.sup.2 from a high-pressure mercury lamp under a nitrogen atmosphere, and then subjected to a heat treatment at 100° C. for 60 minutes to obtain a cured film having a thickness of 1.5 μm. The resulting cured film was subjected to capacitance-voltage (CV) measurement using a mercury prober (product name “SSM-495”, manufactured by SSM Inc.) to determine a relative permittivity at 100 kHz. The evaluation criteria are as follows. A to C are at a level of no practical problem.

[0343] A: 2.8 or less

[0344] B: more than 2.8 and 2.9 or less

[0345] C: more than 2.9 and 3.0 or less

[0346] D: more than 3.0

[0347] E: unmeasurable

Adhesion

[0348] The curable composition was applied onto a SiN substrate by spin coating, irradiated with an ultraviolet ray at an exposure amount of 3000 mJ/cm.sup.2 from a high-pressure mercury lamp under a nitrogen atmosphere, and then subjected to a heat treatment at 100° C. for 5 minutes to obtain a cured film having a thickness of 5 μm. The resulting cured film was subjected to the following crosscut-peeling test to evaluate the adhesion of the cured film to the SiN substrate.

[0349] First, 11 cuts were made in the surface of the cured film at intervals of 1 mm using a cutter knife. 11 cuts were made at intervals of 1 mm so as to be orthogonal to the cuts to form 100 squares. SELLOTAPE (registered trademark) was stuck to the squares, and the end of the SELLOTAPE was peeled off at once at an angle of 45°. The squares were visually observed, and the adhesion was evaluated based on the number of the squares not peeled off.

[0350] The evaluation criteria are as follows.

[0351] A: The number of the squares not peeled off is 80 or more.

[0352] B: The number of the squares not peeled off is less than 80.

TABLE-US-00001 TABLE 1 Example Example Example Example Example Example Example Example Example Example 1 2 3 4 5 6 7 8 9 10 Compound A Type  A1  A1  A2  A3  A4  A1  A1  A1  A1  A1 Content (% 48 72 48 48 48 56 60 46 46 24 by mass) Molecular 788  788  1800  4414  4342  788  788  788  788  788  weight Compound B Type B11 B11 B11 B11 B11 B31 B21 B11 B11 B11 Content (% 48 24 48 48 48 40 36 30 30 72 by mass) Type — — — — — — — B21 B21 — Content (% — — — — — — — 10 10 — by mass) Type — — — — — — — B31 B31 — Content (% — — — — — — — 10  5 — by mass) Polymerization Content (%  4  4  4  4  4  4  4  4  4  4 initiator by mass) Silane coupling Content (% — — — — — — — —  5 — agent by mass) Evaluation Viscosity B B A B A A B A A A Curability B B B B B B A A A B Dielectric B A B A A B B B B C constant Adhesion — — — — — — — B A —

TABLE-US-00002 TABLE 2 Example Example Example Example Example Example Example Example 11 12 13 14 15 16 17 18 Compound A Type A5 A6 A1 A1 A7 — A2 A1 Content (% by mass) 48 72 92  72 48 — 96 50 Molecular weight 5436  448  788  788  764  — 1800  788  Compound B Type B11 B11 B21 B12 B11 B11 — B11 Content (% by mass) 48 24 4 24 48 99  — 50 Polymerization Content (% by mass)  4  4 4  4  4 1  4 — initiator Evaluation Viscosity C A C B B A B B Curability C B C C B A D D Dielectric constant A C A A B D E E Adhesion — — — — — — — —

[0353] As shown in Table 1 and Table 2, in Example 1 to Example 15, the curable composition contained a compound A having a polymerizable group (a) and an oxyfluoroalkylene group, a polymerization initiator, and a compound B having a polymerizable group different from the polymerizable group (a). The polymerizable group (a) in the compound A was at least one selected from the group consisting of a vinylphenyl group, a vinylphenyloxy group, a vinylbenzyloxy group, a vinyloxy group, a vinyloxycarbonyl group, a vinylamino group, a vinylaminocarbonyl group, a vinylthio group, an allyloxy group, an allyloxycarbonyl group, an allylamino group, an allylaminocarbonyl group, an allylthio group, an epoxy group, and an epoxycycloalkyl group. The curable composition had a low viscosity, and the resulting cured film had a low dielectric constant.

[0354] In this regard, in Example 16, the compound A was not contained, whereby the dielectric constant of the resulting cured film was more than 3.0.

[0355] In Example 17, the compound B was not contained, whereby the curable composition had poor curability, and the dielectric constant of the cured film could not be measured.

[0356] In Example 18, the polymerization initiator was not contained, whereby the curable composition was not cured, and the dielectric constant of the cured film could not be measured.

[0357] In Example 1, it was found that the content of the compound A is 40% by mass to 90% by mass with respect to the total amount of the curable composition, whereby the dielectric constant of the resulting cured film is lower than that in Example 10 in which the content of the compound A is less than 40% by mass.

[0358] In Example 7, it was found that the content of the compound A is 40% by mass to 90% by mass with respect to the total amount of the curable composition, whereby the curable composition has a lower viscosity and more excellent curability than those in Example 13 in which the content of the compound A is more than 90% by mass.

[0359] In Example 2, it was found that the molecular weight of the compound A is 500 to 5000, whereby the resulting cured film has a dielectric constant lower than that in Example 12 in which the molecular weight of the compound A is less than 500.

[0360] In Example 3, it was found that the molecular weight of the compound A is 500 to 5000, whereby the curable composition has a viscosity lower than that in Example 11 in which the molecular weight of the compound A is more than 5000.

[0361] In Example 5, it was found that the compound A contains (OC.sub.2F.sub.4).sub.c and (OCF.sub.2).sub.d, and d/c is 2 or more, whereby the curable composition has a viscosity lower than that in Example 4 in which d/c is less than 2.

[0362] It was found that Example 2 containing the compound B11 has more excellent curability than that in Example 14 containing the compound B12.

[0363] The content of the disclosure by Japanese Patent Application No. 2020-113383 filed on Jun. 30, 2020 is herein entirely incorporated by reference. All publications, patent applications, and technical standards mentioned in the specification are herein incorporated by reference to the same extent as if each individual publication, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.