JP6413916B2 - New compounds, insulating film materials, insulating films and organic devices - Google Patents

Description

  The present invention relates to a novel organic compound, and more specifically, an organic compound having a 1,2-dihydrocyclobuta [a] naphthalene skeleton in the structure and useful as an organic insulating film material, and an organic insulating film containing the organic compound The present invention relates to a material and an organic insulating film formed using the organic insulating film material.

In recent years, as a method for forming an organic film in the production of an organic device such as an organic EL, an organic TFT, or an organic solar battery, a coating method is increasingly used instead of the vacuum deposition method.
The characteristics of the organic device are light and thin, but if it can be bent or folded, it is considered that this feature is further utilized. However, in general, a substrate that can be bent or folded may be deformed or colored, so that it is difficult to fire at a high temperature.
As an organic insulating film used for an organic device, an organic insulating film material containing a compound represented by the following formula (A) described in Patent Document 1 is used because of excellent insulating properties.

  Non-Patent Documents 1 to 4 disclose that an organic insulating film material containing a compound represented by the above formula (A) is applied on a substrate to form an organic insulating film.

Japanese Patent Laid-Open No. 1-197491

Nature, 2005, 434, 194-199 Synthetic Metals, 2008, 158, 468-472 Applied Physics Letters, 2013, 103, 243111 Nano Letters, 2014, 14, 3293-3303 European Polymer Journal, 2012, 48, 751-760

However, since the compound represented by the formula (A) does not cause a crosslinking reaction unless it is 220 ° C. or higher (Non-patent Document 5), it is used for organic devices using substrates having low heat resistance and other members. I couldn't.
Accordingly, the present invention provides an organic compound that can cause a crosslinking reaction at a lower temperature, an organic insulating film material that includes the organic compound and can form an organic insulating film by firing at a lower temperature, and It is an object of the present invention to provide an organic insulating film formed using the organic insulating film material.

As a result of intensive studies, the present inventors have found that the above problem can be solved by using an organic compound having a specific partial structure, and have completed the present invention.
That is, the gist of the present invention is as follows [1] to [5].
[1] A compound having a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2).

(In the formula, m represents an integer of 1 or more, R ¹ and R ² each independently represents an alkyl group, and when a plurality of R ¹ or R ² are present, they may be the same or different from each other. .)

[2] The compound according to [1], which is represented by the following formula (4):

(In the formula, m represents an integer of 1 or more, R ^{1 to} R ⁴ each independently represents an alkyl group, and when a plurality of R ¹ or R ² are present, they may be the same as or different from each other. .)
[3] An insulating film material containing the organic compound according to [1] or [2].
[4] An insulating film formed using the insulating film material according to [3].
[5] An organic device comprising the insulating film according to [4] above.

Since the compound of the present invention has a siloxane structure which is a partial structure represented by the above formula (1), the dielectric constant is small and the insulating property is excellent.
In addition, since the compound of the present invention has a vinyl group to which a 1,2-dihydrocyclobuta [a] naphthalene ring, which is a partial structure represented by the above formula (2), is bonded, a crosslinking reaction occurs at a low temperature.

  Therefore, the organic insulating film material containing the compound of the present invention can be baked at a low temperature to form an organic insulating film. Moreover, the formed organic insulating film is excellent in insulation, and can be used for organic devices such as organic EL, organic TFT, and organic solar battery.

It is a figure which shows the result of the differential scanning calorimetry of the compound of the Example of this invention.

Embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention does not exceed the gist thereof. It is not specified in the contents.
<Compound>
The compound of the present invention is characterized by having at least a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2).

(In the formula, m represents an integer of 1 or more, R ¹ and R ² each independently represents an alkyl group, and when a plurality of R ¹ or R ² are present, they may be the same or different from each other. .)

M in the above formula (1) represents an integer of 1 or more. When m is 1 or more, an insulating film having a low dielectric constant and excellent insulating properties and high strength can be obtained. The upper limit of m is not particularly limited, but is usually 100 or less, preferably 10 or less, from the viewpoint of applicability.
In formula (1), R ¹ and R ² each independently represent an alkyl group, but when a plurality of R ¹ or R ² are present, they may be the same or different from each other.

Examples of the alkyl group represented by R ¹ and R ² in the formula (1) include a methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec- Linear, branched, or cyclic alkyl having 1 or more carbon atoms and usually 24 or less, such as butyl group, tert-butyl group, n-hexyl group, n-octyl group, cyclohexyl group, dodecyl group, etc. Groups. In view of high heat resistance, a carbon number of 6 or less is preferable, and a methyl group is particularly preferable.

The partial structure represented by the above formula (2) reacts with energy such as heat and can form a new chemical bond, but a crosslinking reaction occurs at a relatively low temperature. Is also applicable. Formation of this chemical bond (crosslinking reaction) increases the molecular weight, makes it possible to form a high strength film that is insoluble in a solvent or the like.
The number of the partial structures represented by the above formula (2) in the compound of the present invention is not particularly limited, but having two or more is preferable in that a film having high strength is obtained insoluble in a solvent and the like, and 2 More preferably.

As described above, the compound of the present invention has a partial structure of the above formula (1) that has a small dielectric constant and contributes to insulation, and a partial structure of the above formula (2) that contributes to a crosslinking reaction at a low temperature. This is the greatest feature, and the presence or absence of other partial structures is not particularly limited. The molecular weight of the compound of the present invention is usually about 400 to 4000.
The compound of the present invention may contain a partial structure other than the above formula (1) and the above formula (2), and the kind thereof is not particularly limited. For example, —SiR ³ R ⁴ —, —CR ⁵ R ⁶ — , —O—, —CO—, —NR ⁷ —, —S—, and a group selected from the group consisting of an arylene group, and a group in which 2 to 10 groups thereof are linked. Moreover, when connecting 2 or more, 1 type or multiple types may be sufficient. Here, R ^{3 to} R ⁷ each independently represents a hydrogen atom or an optionally substituted alkyl group or aryl group. Examples of the alkyl group include the same groups as those represented by R ¹ and R ² , and preferred groups are also the same. Examples of the substituent that the alkyl group may have include an alkyl group and an aryl group. Examples of the aryl group include aryl groups having 6 to 10 carbon atoms such as a phenyl group, a naphthyl group, and a tolyl group. Among these, -SiR ³ R ^4- is preferable because it has a low dielectric constant and excellent insulating properties, and R ³ and R ⁴ are preferably each independently an alkyl group.

  Specific examples of the compound of the present invention having the partial structure represented by the above formula (1) and the partial structure represented by the above formula (2) include compounds represented by the following structural formula.

(In the formula, R ¹ and R ² each independently represent an alkyl group, R ³ and R ⁴ each independently represent a hydrogen atom or an optionally substituted alkyl group, and m is 1 or more. Q ¹ and Q ² each independently represents a direct bond, a group consisting of —CR ⁵ R ⁶ —, —O—, —CO—, —NR ⁷ —, —S—, and an arylene group. And a group selected by connecting 2 or more thereof, and when two or more are connected, one or more types may be used, where R ^{5 to} R ⁷ are each Independently, it represents a hydrogen atom or an optionally substituted alkyl group or aryl group.
Among these, the compound represented by the following formula (4) can form an organic insulating film by firing at a lower temperature, and the insulating property of the formed organic insulating film is more excellent. preferable.

(Wherein R ^{1 to} R ⁴ and m have the same meanings as in formula (3).)
M in the formulas (3) and (4) represents an integer of 1 or more. When m is 1 or more, an insulating film having high strength can be obtained. The upper limit of m is the same as that described above in Equation (1).
Further, ^{R 1} in the formula (3) and (4), and ^{R 2, R 1} in the above (1), and is the same as ^{R 2,} R 3, ^{R 4} is also the same as above.
More specifically, examples of the compound represented by the formula (3) or (4) include the following compounds.

  Among these, the compound of a following formula is more preferable at the point which is insoluble in an organic solvent easily.

<Method for producing compound>
The compound represented by the above formula (3) or (4) is synthesized, for example, according to the method described below.
First, according to the following formula, vinyl monoalkoxysilanes (a) and (c), or (a ′) and (c ′), and dialkoxysilanes (b) are allowed to act on a base to give compound (d ) Or (d ′).

(In the above reaction formula, R ^{1 to} R ⁴ and Q are the same as those described above, and R ′ represents an alkyl group.)
The synthesis of the above (d) and (d ′) is a known method.
The compound of the present invention represented by the above formula (3) or (4) is a compound of the above formula (d) or (d ′) and the following formula (6):

(Wherein X represents a halogen atom)
Can be synthesized by the Mizorogi-Heck reaction represented by the following formula.

The compound of the above formula (6) is a novel compound previously proposed by the present applicant in Japanese Patent Application No. 2014-40769, and the compound is a 1,2-dihydro compound as shown in the following reaction formula (8). The 4-position can be selectively halogenated and efficiently obtained by allowing N-halides of carboxylic acid imides such as N-bromosuccinimide and N-bromophthalimide to act on cyclobuta [a] naphthalene. Can do.

(In the above reaction formula, X represents a halogen atom.)
In formulas (6) and (8), examples of the halogen atom include I, Br, Cl, F, and the like, and I, Br, and Cl are preferable from the viewpoint that the reaction proceeds easily.
In the reaction of the above formula (8), each raw material is usually dissolved in N, N-dimethylformamide or a mixed solvent of N, N-dimethylformamide and a chlorinated solvent such as methylene chloride, and the solvent is usually used at room temperature. It can be carried out.

  As a conventional method for obtaining a halide of benzocyclobutene which is a crosslinkable group, bromine has been used as shown in the following reaction formula (9) (European Patent No. 346959, J. Am. Chem. Soc. 2011, 133, 49, 19864).

  However, when bromine is allowed to act on 1,2-dihydrocyclobuta [a] naphthalene, other than the 4-position is brominated, so that the target product cannot be obtained efficiently, and separation and purification of the target product is also possible. Have difficulty. Therefore, the conventional method cannot isolate the raw material compound for inducing the partial structure (2) in the compound of the present invention. Therefore, the compound of the present invention is achieved by using the compound of the above formula (7).

<Organic insulating film material>
The compound of the present invention can be particularly preferably used as an insulating film material. In that case, as described below, other components may be contained as long as they do not impair the object of the present invention.
As other components, a paste-like or ink-like resin material is preferable. A resin material may mix a filler, an additive, and a solvent as needed. It is preferable that the resin material has curability or is not easily dissolved in other solvents even if it is not cured. Polyacrylic resin, epoxy resin, phenol resin, polyamide resin, polyimide resin, unsaturated polyester resin , Polyphenylene resin, polyphenylene sulfide resin and the like. The filler is blended as necessary in order to increase the physical strength of the coating film, and known inorganic or organic fillers can be used. Examples thereof include barium sulfate, spherical silica and talc. The blending amount of these fillers is preferably 300 parts by mass or less with respect to 100 parts by mass of the resin. When the compounding quantity of a filler exceeds 300 mass parts, the viscosity of a resin composition becomes high, printability falls, or hardened | cured material becomes weak. More preferably, it is 0.1-300 mass parts, Most preferably, it is 0.1-150 mass parts. Additives such as an antifoaming agent and a leveling agent are 0.01 to 20 parts by mass, preferably 0.05 to 10 parts by mass, particularly preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the resin. A mass part may be included. Solvents are added as necessary to adjust the viscosity when applied to the substrate. Ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatics Examples thereof include hydrocarbons and petroleum solvents.

  Moreover, this compound is 5 mass% or more normally when an insulating film material is 100 mass% in an insulating film material, Preferably it is 10 mass% or more, More preferably, it is 30 mass% or more.

<Insulating film manufacturing method>
The insulating film is usually formed so as to cover the auxiliary electrodes formed in a plurality of stripes. The formation of the insulating film for covering the auxiliary electrode may be performed a plurality of times as necessary to increase the accuracy of insulation.

  The insulating film material containing the compound of the present invention has a partial structure represented by the formula (2). The partial structure reacts with energy such as heat as shown in the formula (10), and a new structure is obtained. A chemical bond can be formed. Formation of this chemical bond (crosslinking reaction) increases the molecular weight, makes it possible to form a high-strength film that is insoluble in a solvent and functions as an organic insulating film.

  As described above, the insulating film material of the present invention is usually in the form of a paste or ink containing an organic solvent, and is usually heated at about 180 to 240 ° C. after forming a film by a conventional coating method. The cross-linking reaction proceeds and an insulating film with high strength is formed.

<Organic devices>
The organic insulating film of the present invention is preferably used for organic devices such as organic EL, organic TFT, and organic solar battery.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples, and the present invention can be arbitrarily modified and implemented without departing from the gist thereof.

<Example 1>
(1) Synthesis 1

1.00 g (6.48 mmol) of 1,2-dihydrocyclobuta [a] naphthalene is dissolved in 15 ml of N, N-dimethylformamide and 1.15 g (6.48 mmol) of N-bromosuccinimide is dissolved in 10 ml of N, N. -A solution dissolved in dimethylformamide was added dropwise at room temperature. After stirring at room temperature for 98 hours, pure water was added and extracted with methylene chloride. The organic layer was concentrated and purified by silica gel column chromatography (acetonitrile: tetrahydrofuran = 9: 1) to obtain Compound 1 (0.56 g).
¹ H-NMR (400 MHz, CDCl ₃ ) δ 3.28 to 3.35 (m, 4H); 7.49 to 7.53 (m, 2H); 7.56 (s, 1H); 7.66 to 7.70 (m, 1H); 8.26-8.30 (m, 1H)
(2) Synthesis 2

In a nitrogen stream, 1.9 g (10.19 mmol) of 1,1,3,3-tetramethyl-1,3-divinyldisiloxane, 4.75 g (20.38 mmol) of compound 1, triethylamine: acetonitrile (10 ml: 30 ml) ) Was stirred for 30 minutes under heating to 40 ° C., 83 mg (0.37 mmol) of palladium acetate and 0.180 g (0.59 mmol) of tri (o-tolyl) phosphine were added, and the mixture was refluxed for 6.5 hours. After allowing to cool to room temperature, the reaction solution was added to 100 ml of 1N hydrochloric acid and stirred for 30 minutes. Thereafter, 100 ml of methylene chloride was added, the aqueous layer was extracted with methylene chloride (50 ml × 2 times), the organic layers were combined, dried over magnesium sulfate, and concentrated. Further, purification by silica gel column chromatography (hexane: ethyl acetate = 99: 1) gave Compound 2 (0.5 g) as colorless crystals.
¹ H-NMR (400 MHz, CDCl ₃ ) δ 0.349 (s, 12 H, CH ₃ ); 3.241 (t, 4 H, CH ₂ ); 3.385 (t, 4 H, CH ₂ ); 6.470 (D, 2H, Si-CH = CH); 7.325 (dd, 2H, ArH); 7.423 (s, 2H, ArH); 7.437 (dd, 2H, ArH); 7.690 (d 2H, ArH); 7.806 (d, 2H, Si—CH═CH); 8.144 (d, 2H, ArH)

(3) DSC analysis Using DSC-50 manufactured by Shimadzu Corporation, differential scanning calorimetry of compound 2 (DSC, under nitrogen, at a heating rate of 10 ° C / min) was performed, as shown in FIG. An exotherm accompanying the crosslinking reaction was observed, rising from about 195 ° C., and the peak top was 235 ° C.

(4) Evaluation
European Polymer Journal, 2012, 48, 751-760, the following comparative compound DV
Although the differential scanning calorimetry result of S-BCB is described, it rose from 224 ° C. and the peak top was 264 ° C.

  From these results, 1,2-dihydrocyclobuta [a] naphthalene contained in Compound 2 of the present invention can undergo a crosslinking reaction at a temperature 29 ° C. lower than benzocyclobutene contained in Comparative Compound DVS-BCB. confirmed. Therefore, the organic insulating film material containing the compound of the present invention can be formed at a lower temperature to form an organic insulating film. For this reason, it can be suitably used for an organic device using a substrate having low heat resistance and other members.

Claims (5)

A compound having a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2).

(In the formula, m represents an integer of 1 or more, R ¹ and R ² each independently represents an alkyl group, and when a plurality of R ¹ or R ² are present, they may be the same or different from each other. .)

It is represented by following formula (4), The compound of Claim 1 characterized by the above-mentioned.

(In the formula, m represents an integer of 1 or more, R ^{1 to} R ⁴ each independently represents an alkyl group, and when a plurality of R ¹ or R ² are present, they may be the same as or different from each other. .)   An insulating film material comprising the organic compound according to claim 1.   An insulating film formed using the insulating film material according to claim 3.   An organic device comprising the insulating film according to claim 4.

Images