JP5445788B2 - Underlayer film composition for image formation - Google Patents

Description

  The present invention relates to a polyimide precursor and / or an underlayer film composition for image formation containing a polyimide obtained by dehydrating and ring-closing this polyimide precursor. Furthermore, the present invention relates to a cured film and an electron produced using the composition. It is about the device.

  In the manufacturing process of an electronic device, it has been proposed to apply a coating technique using a difference in wettability of liquid to patterning of a functional thin film when forming a pattern of an electrode or a functional thin film. This is because a patterning layer composed of a region that easily wets liquid and a region that does not easily wet liquid is formed on the substrate surface, and then a liquid containing a functional thin film forming material is applied onto the patterning layer and then dried. This is a method of forming an electronic device such as an organic EL (electroluminescence) element or an organic FET (field effect transistor) element by forming a functional thin film only in a region that easily gets wet with liquid.

The PEDOT / PSS aqueous solution is mainly used as the image forming liquid used for the pattern formation of the electrode. Since the PEDOT / PSS aqueous solution has a relatively high surface tension, it is formed by a method such as a spin coating method or a printing method. Since it is difficult to form a film, the surface tension is generally adjusted to be low. Since the image forming liquid having a low surface tension exhibits the property of spreading on the substrate to be deposited, in order to suppress the wetting and spreading of the liquid to a region other than the target portion, only the target portion is hydrophilic. It is necessary to make the surface of the region hydrophobic.
In recent years, a polyimide precursor containing a hydrophobic side chain or a polyimide obtained from the polyimide precursor has been adopted as a patterning layer for electrodes, functional thin films, etc., and the water contact angle is changed by changing the hydrophilicity / hydrophobicity of the polyimide film. A technique for painting coating-type functional materials using the fact that they can change has been widely studied.

For example, the characteristics of a wettability changing layer obtained by using a polyimide precursor having an aliphatic ring or a polyimide are specified (for example, see Patent Document 1). In this document, it is presumed that the cleavage of the aliphatic ring of polyimide is one of the factors causing the change in hydrophilicity / hydrophobicity, and the larger the amount of side chains (that is, the number of side chains), the more the surface It is presumed that the energy (critical surface tension) becomes low and the liquid becomes lyophobic.
In Examples of the same document, when polyamic acid obtained by using an acid dianhydride having an aliphatic ring and a diamine having a hydrocarbon group in the side chain is used as a wettability changing layer, the hydrophilicity / hydrophobicity by ultraviolet irradiation is increased. The results show that the change has greatly changed, and it is also shown that an electrode layer made of PEDOT / PSS was formed on the wettability changing layer to produce an electronic device.
International Publication No. 2006/137366 Pamphlet

Usually, the image forming liquid is designed to have a surface tension lower than that of water in order to enable film formation. Therefore, the image forming liquid is often an organic solvent system having a surface tension lower than that of water in consideration of ease of application.
However, in the hydrophobic side chain exemplified in the above document, even when the content of the side chain is sufficiently increased, the hydrophobicity (that is, water repellency) of the unexposed part is not sufficiently high. When the image forming liquid protrudes from the unexposed area, the image forming liquid is dried as it is, and there is a problem that a target image cannot be obtained.

Furthermore, hydrophobic groups generally have a low dielectric constant, and an increase in side chain content leads to a decrease in the dielectric constant. Particularly, highly hydrophobic fluoroalkyl groups have a relative dielectric constant even when compared to other hydrophobic groups. Therefore, there is a problem that it is not preferable in a gate insulating film used for an organic transistor or the like.
For this reason, the lower layer film for image formation mainly used for patterning the source / drain electrodes of the organic transistor must also have a function as a gate insulating film, and therefore includes the above-described fluoroalkyl group in the side chain. There was no example in which a polyimide-based material was used as an underlayer film for image formation.

  As described above, the gate insulating film is generally designed to have a high dielectric constant for the purpose of lowering the driving voltage of the organic transistor, but the side chain containing a fluoroalkyl group is intended to increase the water repellency (hydrophobicity). Increasing the content of the material significantly reduces the relative permittivity, and even if a fine image can be drawn due to high water repellency, the performance of the gate insulating film is degraded. That is, a material having a new hydrophobic side chain capable of obtaining high water repellency while suppressing a decrease in relative dielectric constant has been demanded.

The present invention has been made in view of such circumstances, and the formed underlayer film for image formation has high water repellency (hydrophobicity), and the hydrophilicity / hydrophobicity can be easily changed with a small amount of UV exposure. An object of the present invention is to provide an image-forming underlayer film composition that can suppress the decrease in relative permittivity.
In addition, the formed lower layer film can be applied with an image forming liquid containing a low surface tension solvent as a main solvent by a coating method such as a spin coating method or an ink jet printing method, thereby enabling high-definition patterning (image formation). An object of the present invention is to provide an underlayer film composition for image formation.
Furthermore, it can be baked at a temperature of 200 ° C. or lower (180 ° C. or lower), has a high electrical insulating property and chemical stability, and has an excellent insulating property and low gate leakage current. An object of the present invention is to provide a gate insulating film for an organic transistor.

  As a result of intensive studies to achieve the above object, the present inventors have found that 30 mol% of a phenyl group having a fluoroalkyl group is contained in the polyimide precursor and / or the structure of the polyimide obtained from the polyimide precursor. It is found that by introducing it in a range not exceeding the range, hydrophilicity / hydrophobicity can be greatly changed by ultraviolet irradiation, high water repellency is imparted, and the relative dielectric constant does not decrease. It came to complete.

  That is, as a first aspect, the present invention is selected from the group consisting of a polyimide precursor containing structural units represented by the following formulas (1) and (1a) and a polyimide obtained by dehydrating and ring-closing the polyimide precursor. The present invention relates to an underlayer film composition for image formation, comprising at least one compound.

(In the formula, A represents a tetravalent organic group, B ¹ represents at least one divalent organic group represented by the following formula (2), B ² represents a divalent organic group, R ¹ , R ² , R ^1a and R ^2a each independently represents a hydrogen atom or a monovalent organic group, n is the total number of moles of the structural unit represented by the formula (1), and m is the formula (1a ), And n and m each represent a positive integer and satisfy 0.01 ≦ n / (n + m) ≦ 0.3.)

(In the formula, X ₁ represents a single bond, —O—, —COO—, —OCO—, —CONH—, —CH ₂ O—, and X ₂ represents a divalent organic compound having 3 to 18 carbon atoms. And R ³ represents a perfluoroalkyl group having 2 to 12 carbon atoms.)
As a second aspect, in the formula (1a), B ² is at least one group selected from the group consisting of the following formulas (3) to (5), and the underlayer film composition for image formation according to the first aspect object.

(In the formula, each Y ¹ independently represents a single bond, an ether bond, an ester bond, a thioether bond, an amide bond, an alkylene group which may have a branched structure having 1 to 3 carbon atoms, or the number of carbon atoms. Represents an alkylenedioxo group which may have 1 to 3 branched structures, Y ² represents a single bond, an ether bond, an ester bond, a thioether bond, an amide bond, and R ⁴ each independently represents hydrogen Represents an atom, a methyl group, an ethyl group, or a trifluoromethyl group; R ⁵ represents a hydrogen atom, a methyl group, or a trifluoromethyl group; R ⁶ represents a methylene group or an ethylene group; Represents 0 or 1)
As a third aspect, in the formulas (1) and (1a), the tetravalent organic group represented by A is at least one group selected from the group consisting of the following formulas (6) to (11). The underlayer film composition for image formation according to the first aspect or the second aspect.

(Wherein R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each independently represents a hydrogen atom, a fluorine atom or a hydrocarbon group having 1 to 4 carbon atoms.)
As a 4th viewpoint, the polyimide obtained by dehydrating and ring-closing the polyimide precursor containing the structural unit represented by the said Formula (1) and Formula (1a) and this polyimide precursor is represented by following formula (16). Any one of the first to third aspects, which is a polyimide precursor and polyimide obtained by reacting tetracarboxylic dianhydride with a diamine component represented by the following formulas (17) and (18): The underlayer film composition for image formation described in 1.

(In the formula, A, B ¹ and B ² have the same definitions as in the formula (1) and formula (1a)).
As a fifth aspect, an image-forming underlayer film obtained using the image-forming underlayer film composition according to any one of the first to fourth aspects.
As a sixth aspect, an electrode pattern forming lower layer film obtained using the image forming lower layer film composition according to any one of the first to fifth aspects.
As a seventh aspect, a gate insulating film for an organic transistor obtained using the image-forming underlayer film composition according to any one of the first aspect to the fifth aspect.
As an eighth aspect, an organic transistor obtained using the organic transistor gate insulating film according to the seventh aspect.

An underlayer film composition for image formation containing at least one compound selected from the group consisting of the polyimide precursor of the present invention and a polyimide obtained from the polyimide precursor is a low surface tension solvent in a film formed therefrom. A large change in contact angle, that is, a change in hydrophilicity / hydrophobicity can be imparted to the image forming liquid used as the main solvent by ultraviolet irradiation. Therefore, a lower layer film capable of forming an image of a functional material such as an electrode can be formed using such characteristics.
Furthermore, the cured film formed from the composition of the present invention can form an image-forming underlayer film having a high relative dielectric constant. The lower film for image formation having a high relative dielectric constant can also be used as a gate insulating film for organic transistors. In addition, an image forming lower layer film having a high relative dielectric constant can lower the driving voltage of the organic transistor.
Furthermore, the cured film formed from the composition of the present invention can be applied with an image forming solution by various methods such as spin coating and dipping as well as inkjet, and is therefore an effective material in terms of productivity. It becomes.

The present invention is an image-forming underlayer film composition containing a polyimide precursor having a novel structure and at least one compound selected from the group consisting of polyimides obtained from the polyimide precursor. Furthermore, the present invention relates to a cured film (an image forming lower layer film, an electrode pattern forming lower layer film, an organic transistor gate insulating film) obtained by using the composition, and an electronic device using the cured film.
Details will be described below.

[Polyimide precursor and polyimide obtained from the polyimide precursor]
The present invention provides at least one compound selected from the group consisting of a polyimide precursor containing structural unit units represented by the following formulas (1) and (1a) and a polyimide obtained by dehydrating and ring-opening the polyimide precursor. An underlayer film composition for image formation.

(In the formula, A represents a tetravalent organic group, B ¹ represents at least one divalent organic group represented by the formula (2), B ² represents a divalent organic group, R ¹ , R ² , R ^1a and R ^2a each independently represents a hydrogen atom or a monovalent organic group, n is the total number of moles of the structural unit represented by the formula (1), and m is the formula (1a ), And n and m each represent a positive integer and satisfy 0.01 ≦ n / (n + m) ≦ 0.3.)

In the above formula (1) and formula (1a), the structure of the organic group represented by A is not particularly limited as long as it is a tetravalent organic group. In at least one compound selected from the group consisting of polyimide precursors represented by formula (1) and formula (1a) and polyimide obtained from the polyimide precursor, the structure of the organic group represented by A is 1 Even if it is a kind, multiple kinds may be mixed.
Specific examples of the organic group represented by A include organic groups of the following formulas A-1 to A-36.

The above formulas A-1 to A-36 can be appropriately selected according to required characteristics when used as an image forming lower layer film.
For example, among the formulas A-1 to A-36, A-1 to A-11 are obtained when a polyimide precursor including the structural unit represented by the formula (1) and the formula (1a) is converted to a polyimide. Since the aromatic ring is directly bonded to the imide ring, the insulating property is considered to be reduced (leakage current is large), but the relative dielectric constant is higher than that in the case where the aliphatic ring is directly bonded to the imide ring. It has the feature of becoming higher.
On the other hand, since A-12 to A-35 have an alicyclic structure in the group, they not only have high insulation (leakage current is small) but also ultraviolet rays necessary for contact angle change described later. It is also preferable from the viewpoint that the irradiation amount can be reduced, and A-12 to A-15 are particularly preferable.
In addition, A-17, A-27, A-29, A-30, A-31, A-32, A-36, etc. can reduce the irradiation amount of ultraviolet rays necessary for changing the contact angle, and When polyimide is used, it is most preferable because of its high solubility in a solvent. Further, a plurality of types of tetravalent organic groups having an alicyclic structure may be used in combination for the purpose of improving the solubility and reducing the irradiation amount of ultraviolet rays necessary for the change of hydrophilicity / hydrophobicity.

In the above formula (1), B ₁ is a divalent organic group having a fluoroalkyl group, and specifically represents at least one divalent organic group represented by the following formula (2).

(In the formula, X ₁ represents a single bond, —O—, —COO—, —OCO—, —CONH—, —CH ₂ O—, and X ₂ represents a divalent organic compound having 3 to 18 carbon atoms. And R ³ represents a perfluoroalkyl group having 2 to 12 carbon atoms.)

The fluoroalkyl group represented by R ³ has a small surface free energy and can impart high water repellency. However, when the number of carbon atoms is less than 2, high water repellency cannot be obtained. It is desirable that the number of carbon atoms is 2 or more to 12 and more preferably 4 to 8 because not only the control is difficult but also the relative dielectric constant is lowered.

Further, by increasing the fluorine content, higher water repellency can be obtained. However, in the structure in which all the long-chain alkyls are fluorinated, the relative dielectric constant is greatly reduced.
For this reason, by using a carbon chain such as an alkylene group containing no fluorine atom as a spacer (X ₂ in the formula (2)), it is possible to obtain a high water repellency while suppressing a decrease in the dielectric constant. .

X ₂ is a divalent organic group having 3 to 18 carbon atoms, more preferably a divalent organic group having 6 to 18 carbon atoms, and most preferably 9 to 18 carbon atoms.
The structure is not particularly limited as long as X ₂ is a divalent organic group having 3 to 18 carbon atoms. Preferably, X ₂ is a divalent hydrocarbon group having an alkylene group, an aromatic ring or an aliphatic ring, or both. Selected.

In formula (2), X ₂ may be directly bonded to the benzene ring, but may be bonded via a linking group. That is, in Formula (2), X ₁ includes a single bond, —O—, —COO—, —OCO—, —CONH—, and —CH ₂ O—.

Specific examples of B ¹ which is a divalent organic group represented by the formula (2) include the following formulas (12) to (15).

Incidentally, the hydrophilic - change in contact angle indicating a hydrophobic variation is believed to occur by fluoro containing side chains of formula (1) Medium B ¹ is degraded by ultraviolet radiation. In addition, it is known that the tetravalent organic group represented by A described above is also decomposed by ultraviolet rays, and the contact angle changes greatly (Patent Document 1).

In the general formula (1), the divalent organic group having a fluoroalkyl represented by B ¹ (group represented by the formula (2)) can impart high water repellency even in a small amount. However, if the content is excessively increased, the relative dielectric constant is decreased and the amount of change in hydrophilicity / hydrophobicity due to irradiation with ultraviolet rays is also decreased. Therefore, a divalent organic group represented by B ² below is used in combination.

In the above formula (1a), B ² is a divalent organic group, and an organic group that satisfies the following requirements is preferable.
Conventionally, long-chain side chains have been introduced for the purpose of imparting water repellency. As described above, since the fluoroalkyl group in the B ¹ group can impart high water repellency in a small amount, the introduction ratio of long-chain side chains Therefore, from the viewpoint of imparting water repellency, that is, reducing the surface free energy, long-chain alkyl groups other than fluoroalkyl groups are not necessary, but rather they are not included because they cause a decrease in relative dielectric constant. Is preferred.
In addition, the reduction of the introduction ratio of the long side chain is preferable from the viewpoint that the density of the contact angle change site (acid anhydride component) is increased and the improvement in sensitivity can be expected. In this specification, the sensitivity represents the degree of conversion from hydrophobicity to hydrophilicity per exposure amount (ultraviolet ray irradiation amount).

That is, the divalent organic group represented by B ² should have an aromatic ring from the viewpoint of satisfying the above conditions, efficiently absorbing ultraviolet rays, and efficiently changing the contact angle. preferable. For example, an organic group represented by the following formulas (3) to (5) is desirable.

(In the formula, each Y ¹ independently represents a single bond, an ether bond, an ester bond, a thioether bond, an amide bond, an alkylene group which may have a branched structure having 1 to 3 carbon atoms, or the number of carbon atoms. Represents an alkylenedioxo group which may have 1 to 3 branched structures, Y ² represents a single bond, an ether bond, an ester bond, a thioether bond, an amide bond, and R ⁴ each independently represents hydrogen Represents an atom, a methyl group, an ethyl group, or a trifluoromethyl group; R ⁵ represents a hydrogen atom, a methyl group, or a trifluoromethyl group; R ⁶ represents a methylene group or an ethylene group; Represents 0 or 1)

Specific examples of B ² represented by the above formulas (3) to (5) include the following divalent organic groups B-1 to B-23.

Among these, B-2, B-3, B-5, B-10, and B-13 are more preferable because they have high solubility and can produce a soluble polyimide having high solubility.
Further, the divalent organic group represented by B ² may be used in combination of two or more from the viewpoints of solubility and reduction of exposure amount. In addition, other divalent organic groups having a long alkyl side chain can be used as long as the dielectric constant does not decrease.

As described above, in the general formula (1), the fluoroalkyl contained in the B ¹ group leads to a decrease in relative permittivity and a decrease in hydrophilicity / hydrophobicity change due to ultraviolet irradiation when the content is excessively increased. Therefore, the divalent organic group represented by B ² is used in combination.
However, if the content of the fluoroalkyl group is too small, the water repellency of the unexposed area is lowered, and it becomes impossible to pattern an image forming liquid having a low surface tension.
Therefore, the content ratio of B ¹ and B ² , that is, the ratio of n represented in formula (1) to m represented in formula (1a) is preferably 0.01 ≦ n / (n + m) <. It is desirable that the ratio be 0.1, most preferably 0.01 ≦ n / (n + m) <0.06.

<< Method for producing polyimide precursor >>
In order to obtain the polyimide precursor containing the structural unit represented by the formula (1) and the formula (1a), a tetracarboxylic dianhydride component represented by the following formula (16) and the following formulas (17) and ( A method of mixing the diamine component represented by 18) in an organic solvent is simple. These tetracarboxylic dianhydride components and diamine components may each be one kind or two or more kinds.

(In the formula, A is a tetravalent organic group, B ¹ is a divalent organic group represented by the general formula (2), and B ² represents a divalent organic group other than B ¹ . )

In the tetracarboxylic dianhydride component represented by the above formula (16), specific examples of the tetravalent organic group represented by A include those represented by the above formulas A-1 to A-36. .
In the diamine component represented by the above formula (17) or (18), B ¹ is a divalent organic group containing a fluoroalkyl group, specifically represented by the above formulas (12) to (15). What is done. Specific examples of the divalent organic group represented by B ² include those represented by the aforementioned formulas B-1 to B-23.

As indicated above, A is an organic group containing many tetravalent organic groups containing an aliphatic ring, that is, the tetracarboxylic dianhydride component has a high proportion of aliphatic acid dianhydrides. Those are preferred.
This is because, when a polyimide precursor or the like is produced using an aromatic acid anhydride and a cured film is formed, insulation is significantly reduced when a high electric field is applied to the cured film. This is because the material has excellent insulation in a high electric field.
For example, the operating voltage of the organic transistor may be about 1 MV / cm, and in the case of the application, it is desirable to use an aliphatic acid anhydride as a raw material for the polyimide precursor from the viewpoint of insulation.

As a method of mixing the tetracarboxylic dianhydride component and the diamine component in an organic solvent, the solution in which the diamine component is dispersed or dissolved in the organic solvent is stirred, and the tetracarboxylic dianhydride component is left as it is. Or a method of adding by dispersing or dissolving in an organic solvent, conversely a method of adding a diamine component to a solution in which a tetracarboxylic dianhydride component is dispersed or dissolved in an organic solvent, a tetracarboxylic dianhydride component and a diamine component A method of alternately adding can be mentioned.
In addition, a compound having a plurality of tetracarboxylic dianhydride components and diamine components may be subjected to a polymerization reaction in a state in which these plurality of components are mixed in advance, or may be separately sequentially polymerized.

  When the polyimide precursor used in the present invention is produced from a tetracarboxylic dianhydride component represented by the above formula (16) and a diamine represented by the above formulas (17) and (18), both components It is desirable that the blending ratio, that is, <the total number of moles of the tetracarboxylic dianhydride component>: <the total number of moles of the diamine component> is 1: 0.5 to 1: 1.5. Similar to the normal polycondensation reaction, the closer the molar ratio is to 1: 1, the higher the degree of polymerization of the polyimide precursor produced, and the higher the molecular weight.

In the method for producing the polyimide precursor, the temperature at which the tetracarboxylic dianhydride component and the diamine component are reacted in an organic solvent is usually −20 to 150 ° C., preferably 0 to 80 ° C.
If the reaction temperature is set to a high temperature, the polymerization reaction proceeds rapidly and is completed, but if it is too high, a high molecular weight polyimide precursor may not be obtained.

  In the polymerization reaction performed in an organic solvent, the solid content concentration of both components (tetracarboxylic dianhydride component and diamine component) in the solvent is not particularly limited, but if the concentration is too low, a high molecular weight polyimide precursor is added. When the concentration is too high, the viscosity of the reaction solution becomes too high and uniform stirring becomes difficult, so 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the polymerization reaction may be performed at a high concentration, and an organic solvent may be added after the formation of the polymer (polyimide precursor).

  The organic solvent used in the above reaction is not particularly limited as long as the produced polyimide precursor can be dissolved, but N, N-dimethylformamide, N, N-dimethylform can be mentioned as specific examples. Examples include acetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulfone, hexamethyl sulfoxide, and γ-butyrolactone. These may be used alone or in admixture of two or more. Furthermore, even if it is a solvent which does not dissolve a polyimide precursor, you may mix with the said solvent in the range which the produced | generated polyimide precursor does not precipitate.

  The solution containing the polyimide precursor thus obtained can be used as it is for the preparation of an image-forming underlayer film coating solution described later. Further, the polyimide precursor can be precipitated and isolated in a poor solvent such as water, methanol, ethanol, etc. and recovered for use.

<Conversion to polyimide>
The polyimide precursor having the structural unit represented by the general formula (1) and the formula (1a) can be converted to a polyimide by dehydration ring closure. Although the method of this imidation reaction is not particularly limited, the catalyst imidization using a basic catalyst and an acid anhydride is unlikely to cause a decrease in the molecular weight of the polyimide during the imidation reaction, and the imidation rate can be easily controlled. preferable.

Catalytic imidation is possible by stirring the polyimide precursor in an organic solvent for 1 to 100 hours in the presence of a basic catalyst and an acid anhydride.
Here, as the polyimide precursor, a solution containing the polyimide precursor obtained by polymerization of the above-described tetracarboxylic dianhydride component and diamine component may be used as it is (without isolation).
Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine and the like. Of these, pyridine is preferable because it has a suitable basicity for proceeding with the reaction.
Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Among them, acetic anhydride is preferable because the obtained polyimide can be easily purified after imidization.
As an organic solvent, the solvent used at the time of the polymerization reaction of the polyimide precursor mentioned above can be used.

The reaction temperature for the catalyst imidization is preferably -20 to 250 ° C, more preferably 0 to 180 ° C. If the reaction temperature is set to a high temperature, imidization proceeds rapidly, but if it is too high, the molecular weight of the polyimide may decrease.
The amount of the basic catalyst is preferably 0.5 to 30 mol times, more preferably 2 to 20 mol times based on the acid amide group in the polyimide precursor. Further, the amount of the acid anhydride is preferably 1 to 50 mol times, more preferably 3 to 30 mol times based on the acid amide group in the polyimide precursor.
By adjusting the reaction temperature and the amount of catalyst, the imidization ratio of the resulting polyimide can be controlled.

  Although the solvent-soluble polyimide reaction solution obtained as described above can be used as it is for the production of the gate insulating film described later, the reaction solution contains an imidization catalyst and the like. After purification, recovery and washing, it is preferable to use the membrane for later production.

The polyimide can be easily recovered by putting the reaction solution into a poor solvent that is being stirred to precipitate the polyimide and filtering it.
Although it does not specifically limit as a poor solvent used in this case, Methanol, hexane, heptane, ethanol, toluene, water etc. can be illustrated. After the precipitate is collected by filtration, it is preferably washed with the above poor solvent.
The recovered polyimide can be made into a polyimide powder by drying at normal temperature or under reduced pressure at room temperature or by heating.

If the operation of dissolving this polyimide powder in a good solvent and reprecipitating it in a poor solvent is repeated 2 to 10 times, the impurities in the polymer can be further reduced.
Good solvents used at this time include N, N-dimethylformamide, N, N-dimethylacetamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, γ-butyrolactone and the like can be mentioned. These may be used alone or in combination.
Further, when three or more kinds of poor solvents such as alcohols, ketones, and hydrocarbons are used as the poor solvent used for reprecipitation, the purification efficiency is further improved.

[Underlayer film composition for image formation]
The underlayer film composition for image formation of the present invention is a composition that contains the polyimide precursor and / or the polyimide, and a solvent, and can further contain a coupling agent, a surfactant, and the like as described below if desired. is there.

  The molecular weight of the polyimide precursor and / or polyimide used in the underlayer film composition for image formation of the present invention is a weight average molecule (GPC) from the viewpoint of ease of handling and stability such as solvent resistance when the film is formed. 2,000 to 200,000 are preferable, and it is desirable to use those having a measurement result of 5,000 to 50,000.

When a cured film is produced using the underlayer film composition for image formation of the present invention and irradiated with ultraviolet rays, there is no significant difference between the polyimide precursor and the polyimide with respect to the amount of change in hydrophilicity / hydrophobicity, so the cured film obtained However, when emphasizing this point, the imidation rate is not particularly limited.
However, by using polyimide, it is possible to obtain a highly reliable film by low-temperature firing (180 ° C. or less) that can be used for plastic substrates, and polyimide has a lower polarity than polyimide precursor, and before ultraviolet irradiation. Since advantages such as a high water contact angle (high hydrophobicity) can be obtained, it is more preferable to use polyimide.

In the lower layer film composition for image formation of the present invention, electrode formation for organic transistors is assumed as a main application, and not only a function as a lower layer film for image formation but also high insulation is required.
Thus, when using for the cured film (for example, gate insulating film) which attaches importance to insulation, it is preferable to make the polyimide which imidized the polyimide precursor melt | dissolved in a solvent directly, and to make the lower layer film formation composition for image formation. .
In this case, when the imidization rate is high, the solvent solubility is lowered, but the imidation rate is preferably high as long as the solubility is not impaired, specifically 80% or more, more preferably 90% or more.
In the present invention, the imidization ratio is defined as the imidization ratio obtained by dissolving polyimide in d ₆ -DMSO (dimethyl sulfoxide-d ₆ ), measuring ¹ H-NMR, and measuring the ratio between the number of amide protons and the number of aromatic protons. The ratio of the amic acid groups remaining without being calculated and the imidization rate calculated.

  The solvent used in the underlayer film composition for image formation of the present invention is not particularly limited as long as it can dissolve a polyimide precursor or polyimide, and examples thereof include N, N-dimethylformamide, N, N-dimethyl. Good such as acetamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-methylcaprolactam, dimethyl sulfoxide, tetramethylurea, pyridine, γ-butyrolactone A solvent is mentioned. These may be used alone or as a mixture, and a poor solvent such as alcohols, ketones and hydrocarbons may be mixed with the good solvent.

  The ratio of the total mass of the polyimide precursor and / or polyimide in the underlayer film composition for image formation of the present invention is not particularly limited as long as the polyimide precursor and / or polyimide is uniformly dissolved in the solvent. Is, for example, 1 to 30% by mass, and for example 5 to 20% by mass.

  The method for preparing the underlayer film composition for image formation of the present invention is not particularly limited, but a solution containing the polyimide precursor obtained by polymerization of the above-described tetracarboxylic dianhydride component and diamine component, or the solution is used. The obtained polyimide reaction solution may be used as it is.

  In addition, the image-forming underlayer film composition of the present invention may further contain a coupling agent for the purpose of improving the adhesion between the composition and the substrate as long as the effects of the present invention are not impaired. it can

Examples of the coupling agent include functional silane-containing compounds and epoxy group-containing compounds. Specifically, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxy Silane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxy Silane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-trimethoxysilylpropyltriethylenetriamine, N-triethoxy Siri Propyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9- Triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N -Phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, ethylene glycol diglycidyl ether, polyethylene Glycol diglycid Ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl Glycol diglycidyl ether, 6-tetraglycidyl-2,4-hexanediol, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) Mention may be made of compounds such as cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane.
These may be used alone or in combination of two or more.

  When the coupling agent is used, the content is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the image forming lower layer film composition. is there.

  Furthermore, the lower layer film composition for image formation of the present invention contains a surfactant for the purpose of improving the coating property of the composition, the film thickness uniformity and the surface smoothness of the film obtained from the composition. You can also.

  Although it does not restrict | limit especially as said surfactant, For example, a fluorine-type surfactant, a silicone type surfactant, a nonionic surfactant, etc. are mentioned. Examples of this type of surfactant include F-top EF301, EF303, EF352 (manufactured by Gemco), MegaFuck F171, F173, R-30 (manufactured by Dainippon Ink & Chemicals, Inc.), Florard FC430. FC431 (manufactured by Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (Asahi Glass Co., Ltd.).

  When the surfactant is used, the content thereof is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 100 parts by mass of the polymer component contained in the image forming lower layer film composition. Thru | or 1 mass part.

[About polymer blends]
The underlayer film composition for image formation according to the present invention is mixed with the polyimide precursor and / or polyimide according to the present invention in addition to another polymer capable of forming a film (for example, a highly insulating polymer) to form a so-called polymer blend. It is also possible to take.
In this polymer blend, by appropriately adjusting the structure of the contained polymer (polyimide precursor of the present invention, polyimide, and other polymers), etc., when a cured film is formed, each polymer in the thickness direction in the film is Since a concentration gradient can be generated, it can be used as a useful means.

For example, since the change in hydrophilicity / hydrophobicity becomes a problem only on the film surface, from this point of view, the polyimide precursor and / or polyimide having the fluoroalkyl group of the present invention is only in the upper layer (surface layer) of the cured film. It only has to exist.
Therefore, when the image-forming underlayer film composition is in the form of a polymer blend, the blending ratio of the polyimide precursor or polyimide of the present invention is 1% by mass to 100% by mass with respect to the total mass of the blended polymer. is there. When the content is 1% by mass or less, the polyimide precursor or polyimide of the present invention on the outermost surface of the formed film becomes insufficient, and the image forming ability may be deteriorated.

The polymer blend is useful when, for example, the image-forming underlayer film composition of the present invention is used for a gate insulating film application that requires particularly high insulation.
When used in gate insulating film applications, the coating solution can handle a baking temperature of 180 ° C. or lower, can be formed by coating, and has solvent resistance to organic semiconductor coating solutions (nonpolar solvents such as xylene and trimethylbenzene), low Various characteristics such as water absorption are required, but the required performance for insulation is particularly high. In order to achieve this high insulating property, the imidation rate of the image-forming underlayer film composition of the present invention is required to be at least 80% or more, and in some cases 90% or more. If it exceeds%, the solubility in the solvent may decrease. At this time, a high insulating layer is positioned only in the lowermost layer of the insulating film, and a layer made of the lower film composition for image formation of the present invention is positioned in the upper layer, thereby maintaining the high insulating property of the insulating film. In addition, the solubility problem can be solved.

As described above, in order to make the lower layer of the cured film a high insulating layer and the upper layer to be a hydrophilic / hydrophobic conversion layer, these layers can be sequentially laminated, but the operation is complicated.
At this time, the material of the high insulating layer and the material of the hydrophilic / hydrophobic conversion layer (that is, the polyimide precursor and / or polyimide of the present invention) are mixed, and the polarity or molecular weight of the upper layer material is compared with that of the lower layer. If the mixture is small, the above-mentioned concentration gradient (herein referred to as layer) is used because the upper layer material moves to the surface and forms a layer while the mixture is applied to the substrate and dried to evaporate the solvent. Separation) can be easily controlled.

The most preferable material for forming a highly insulating film capable of forming the lower layer is soluble polyimide. When soluble polyimide is used as the lower layer material, from the viewpoint of insulation, it is desirable that the imidation ratio of the polyimide in the solution is high, and it is at least 50% or more, preferably 80% or more, and most preferably 90% or more.
Other materials that can be used as the lower layer material include general organic polymers such as epoxy resin, acrylic resin, polypropylene, polyvinyl alcohol, polyvinyl phenol, polyisobutylene, and polymethyl methacrylate.

  In addition, when the polymer blend is used for, for example, an organic transistor application requiring a film thickness of around 400 nm, the polymer precursor of the present invention and / or the polymer blend of polyimide required for providing an upper layer (hydrophobic / hydrophobic conversion layer). The content ratio is theoretically about 1%, but if it is too small, there will be a large variation in the surface properties of the cured film, so that it contains at least 5% of the polyimide precursor and / or polyimide. Is preferred.

[Method for producing coating film and cured film]
The underlayer film composition for image formation of the present invention is formed on a general-purpose plastic substrate or glass substrate such as polypropylene, polyethylene, polycarbonate, polyethylene terephthalate, polyethersulfone, polyethylene naphthalate, polyimide, etc., by dipping, spin coating, A coating film can be formed by applying by a transfer printing method, a roll coating method, an ink jet method, a spray method, a brush coating, etc., and then pre-drying with a hot plate or oven. Then, the coating film is heated to form a cured film that can be used as an image forming lower layer film or an insulating film.

Although it does not specifically limit as a method of the said heat processing, The method performed in a suitable atmosphere, ie, inert gas, such as air | atmosphere and nitrogen, a vacuum, etc. can be illustrated using a hotplate and oven.
The firing temperature is preferably 180 ° C. to 250 ° C. from the viewpoint of promoting thermal imidization of the polyimide precursor, and more preferably 180 ° C. or less from the viewpoint of forming a film on a plastic substrate.
Firing may be performed at two or more stages. The uniformity of the film obtained by baking in steps can be further increased.

  Further, when forming a cured film, the image-forming underlayer film composition is in a form containing a polyimide precursor and / or polyimide and the above-described solvent, and thus can be used as it is for application to a substrate. For the purpose of ensuring the flatness of the coating film, improving the wettability of the coating liquid to the substrate, adjusting the surface tension, polarity, boiling point of the coating liquid, etc. It may be added and used as a coating solution.

  Specific examples of such a solvent include 1-methoxy-2, such as ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, and ethylene glycol, in addition to the solvents described in the above paragraph (0071). -Propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene Glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-methoxypropoxy) propanol, 2- (2-ethoxypropoxy) propanol and 2- (2-butoxypropoxy) Shi) propylene glycol derivatives such as propanol, methyl lactate ester, ethyl lactate esters, lactate n- propyl ester, lactate n- butyl ester, lactic acid derivatives such as lactic isoamyl ester. These may be used alone or in combination.

From the viewpoint of improving the storage stability of the underlayer film composition for image formation and the film thickness uniformity of the coating film, 20 to 80% by mass of the total amount of solvent is N, N-dimethylformamide, N, N-dimethyl. It is preferable to use at least one solvent selected from acetamide, N-methyl-2-pyrrolidone, γ-butyrolactone, and dimethyl sulfoxide.
The concentration of the lower layer film composition for image formation is not particularly limited, but is preferably 0.1 to 30% by mass, more preferably 1 to 10% by mass as the solid content concentration of the polyimide precursor and polyimide. These are arbitrarily set according to the specifications of the coating apparatus and the film thickness to be obtained.

  When the cured film of the present invention produced as described above is used as an underlayer film for image formation, if the film thickness is too thin, the patternability after ultraviolet irradiation is lowered, and if it is too thick, the surface uniformity is impaired. Accordingly, the film thickness is preferably 5 nm to 1000 nm, more preferably 10 nm to 300 nm, and most preferably 20 nm to 100 nm.

  In addition, the cured film of the present invention can function as an insulating film when the insulating property is sufficiently high. In that case, the cured film is directly disposed on the gate electrode in an organic FET element, for example, and used as a gate insulating film. At that time, the thickness of the cured film is preferably thicker than that used for the image forming lower layer film for the purpose of ensuring insulation. The film thickness is preferably 20 nm to 1000 nm, more preferably 50 nm to 800 nm, and most preferably 100 nm to 500 nm.

[Use as lower layer film for image formation: Method for producing electrode for image formation]
An image forming electrode can be produced by irradiating the image forming lower layer film of the present invention with ultraviolet rays in a pattern and subsequently applying an image forming liquid described later.

In the present invention, the method of irradiating the image forming sublayer film with ultraviolet rays in a pattern is not particularly limited, but for example, a method of irradiating through a mask on which an electrode pattern is drawn, an electrode pattern using laser light The method of drawing is mentioned.
The material and shape of the mask are not particularly limited, as long as the region requiring the electrode transmits ultraviolet light and the other region does not transmit ultraviolet light.

  At this time, it is generally possible to use ultraviolet rays having a wavelength in the range of 200 nm to 500 nm for irradiation, and it is desirable to select the wavelength appropriately through a filter or the like depending on the type of polyimide used. Specific examples include wavelengths such as 248 nm, 254 nm, 303 nm, 313 nm, and 365 nm. Particularly preferred are 248 nm and 254 nm.

  The surface energy of the underlayer film for image formation of the present invention is gradually increased by irradiation with ultraviolet rays, and is saturated with a sufficient irradiation amount. This increase in surface energy results in a decrease in the contact angle of the image forming liquid, and as a result, the wettability of the image forming liquid in the ultraviolet irradiation section is improved.

  Therefore, when the image forming liquid is applied on the image forming lower layer film of the present invention after the ultraviolet irradiation, the image forming liquid is self-organized along the pattern shape drawn as the difference in surface energy on the image forming lower layer film. Patterns can be formed automatically, and electrodes having an arbitrary pattern shape can be obtained.

For this reason, it is necessary to irradiate the lower layer film for image formation with an amount of ultraviolet light that sufficiently changes the contact angle of the image forming solution, but it is 40 J / cm ² or less from the viewpoint of energy efficiency and shortening of the manufacturing process. Preferably, it is 20 J / cm ² or less, and most preferably 10 J / cm ² or less.

In addition, the larger the difference in the contact angle of the image forming liquid between the UV-irradiated part and the non-irradiated part of the image-forming underlayer film, the easier the patterning becomes, and it becomes possible to process the electrode into a complicated pattern or a fine pattern shape. Become. When a solution having a low surface tension is used, the contact angle difference between the exposed part and the unexposed part is preferably 5 ° or more, more preferably 10 ° or more, and most preferably 20 ° or more. However, it is better to optimize appropriately in consideration of the application method of the image forming liquid, the surface tension of the image forming liquid, the fineness of the image, and the flatness of the film.
For the same reason, it is preferable that the contact angle of the image forming liquid is 30 ° or more in the ultraviolet non-irradiated portion and 20 ° or less in the ultraviolet irradiated portion.

  The image forming liquid in the present invention is a coating liquid that can be used as a functional thin film by evaporating the solvent contained therein after being applied to a substrate. For example, the charge transporting substance is at least one kind. Examples thereof include those dissolved or uniformly dispersed in a solvent. Here, the charge transportability is synonymous with conductivity, and means any one of hole transportability, electron transportability, and both charge transportability of holes and electrons.

The charge transporting substance is not particularly limited as long as it has conductivity capable of transporting holes or electrons. Examples thereof include, for example, metal fine particles such as gold, silver, copper and aluminum, inorganic materials such as carbon black, fullerenes and carbon nanotubes, and organic π-conjugated polymers such as polythiophene, polyaniline, polypyrrole, polyfluorene and derivatives thereof. Etc.
In addition, halogen, Lewis acid, proton acid, transition metal compound (specific examples include Br ₂ , I ₂ , Cl ₂ , FeCl ₃ , MoCl ₅ , BF ₄ , AsF ₆ for the purpose of improving the charge transporting ability of the charge transport material. , SO ₄ , HNO ₄ , H ₂ SO ₄ , polystyrene sulfonic acid, etc.), or alkali metals, alkylammonium ions (specific examples are Li, Na, K, Cs, tetraethyleneammonium, tetoabutyl) A charge donating substance such as ammonium) may be further added to the image forming solution as a dopant.

  The solvent for the image forming solution is not particularly limited as long as it dissolves or uniformly disperses the charge transporting substance or dopant. From the viewpoint of obtaining an accurate electrode image (pattern), the surface tension of the image forming liquid is preferably 25 mN / m to 50 mN / m. When the surface tension is too lower than the above range, it does not show a sufficiently large contact angle with respect to the unirradiated part of the ultraviolet ray, and when the surface tension is too high than the above range, the contact angle of the ultraviolet ray irradiated part becomes high, and This is not preferable because the amount of irradiation increases.

The solvent for the image forming solution is not particularly limited, and various organic solvents such as alcohols, ketones, ethers, esters, aromatic hydrocarbons, glycols and the like can be used. Examples of alcohols include methanol, isopropanol, normal butanol, isobutanol, secondary butanol, isoamyl alcohol, octanol and the like. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone / diacetone alcohol. Examples of ethers include ether / isopropyl ether, dioxane, methyl cellosolve, ethyl cellosolve, and butyl cellosolve. Examples of the esters include ethyl acetate, butyl acetate, isobutyl acetate, amyl acetate, cellosolve acetate, and fatty acid methyl ester. Aromatic hydrocarbons include benzene, toluene, xylene, mesitylene and the like.
Examples of the aliphatic hydrocarbons include normal hexane, isohexane, cyclohexane, mineral terpene, and normal pentane. Examples of glycols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and propylene glycol monomethyl ether.

N, N-dimethylformamide, N, N-dimethylacetamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-methylcaprolactam, dimethyl Polar solvents such as sulfoxide and tetramethylurea are also preferable from the viewpoint of excellent solubility of the organic charge transporting substance, but these are preferably used in a range where the damage to the lower layer film for image formation of the present invention is small. .
Although a solvent having a particularly large surface tension such as water can be used, it is preferable to adjust the surface tension by adding a surfactant or the like.

  The concentration of the charge transporting substance in the image forming liquid is preferably 0.01 to 30% by mass, more preferably 0.1 to 10% by mass, and most preferably 1 to 5% by mass.

  Specific examples of the image forming liquid according to the present invention include conductive polymer solutions such as Baytron (registered trademark) P (polyethylenedioxythiophene, manufactured by Bayer), Dotite XA-9069 (manufactured by Fujikura Kasei), W4A (Sumitomo). And silver fine particle dispersions such as NPS-J (manufactured by Harima Chemicals).

  The electrode according to the present invention is produced by applying the image forming liquid on the image forming lower layer film of the present invention to form an image and then evaporating the solvent. The method for evaporating the solvent is not particularly limited, but a uniform film-forming surface is obtained by evaporating in an appropriate atmosphere, that is, in an inert gas such as air or nitrogen, in a vacuum, or the like, using a hot plate or an oven. Can be obtained.

  The temperature for evaporating the solvent is not particularly limited, but is preferably 40 to 250 ° C. From the standpoint of maintaining the shape of the lower layer film for image formation and achieving film thickness uniformity, a temperature change in two or more steps may be applied.

  Electrodes prepared from this image forming solution are used not only as wirings for connecting electronic devices but also as electrodes for electronic devices such as field effect transistors, bipolar transistors, various diodes, and various sensors.

The electronic device according to the present invention has an electrode formed from the image forming solution formed on the image forming lower layer film of the present invention.
Although the example which used the lower film | membrane for image formation of this invention for the organic FET element below is shown, this invention is not limited to this.

  First, a glass substrate having an ITO electrode formed on one side is prepared. It is preferable that the substrate is cleaned in advance by cleaning with a liquid such as a detergent, alcohol, or pure water, and surface treatment such as ozone treatment or oxygen-plasma treatment is performed immediately before use. A layer containing a polyimide precursor and / or a polyimide having the structural unit represented by the general formula (1) and the formula (1a) on the substrate with an ITO electrode is added to the above-mentioned method for producing a coating film and a cured film. ] Is formed according to the procedure. The thickness of the layer is most preferably set to 100 nm to 1000 nm in consideration of the driving voltage and the electrical insulation. Thereafter, ultraviolet rays are irradiated in a pattern using a mask or the like.

  Subsequently, an image forming liquid using a low surface tension solvent such as PGME is applied to the surface of the lower layer film for image formation. The applied image forming solution spreads and stabilizes quickly in the hydrophilic part (ultraviolet irradiation part) to repel the hydrophobic part (ultraviolet irradiation part), and is dried to form patterned source and drain electrodes. Is done. The application method of the image forming liquid is not particularly limited, such as a spin coating method or a casting method, but an ink jet printing method or a spray coating method that allows easy control of the liquid amount is preferable.

  Finally, it is completed by depositing an organic semiconductor material such as pentacene or polythiophene, which is an active layer of the organic FET. A method for forming the organic semiconductor material is not particularly limited, and examples thereof include vacuum deposition and solution spin coating, casting, ink jet printing, and spray coating.

In this way, the manufactured organic FET can greatly reduce the manufacturing process, and further, an organic FET having a channel shorter than that of the mask vapor deposition method can be manufactured. Even when a semiconductor material is used, a large current can be taken out. As an insulating film for an organic transistor, a possible one is a film having a relative dielectric constant of 3.0 or more. Since the lower layer film for image formation obtained by the method of the present invention has excellent electrical insulation and a high relative dielectric constant of 3.0, it can also be used as a gate insulating layer (insulating film). The manufacturing process can be further simplified.
A schematic cross-sectional view of an organic transistor prepared by the above method is shown in FIG.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

[Measurement of number average molecular weight and weight average molecular weight]
The number average molecular weight (hereinafter referred to as Mn) and the weight average molecular weight (hereinafter referred to as Mw) of the polyimide precursor obtained according to the following synthesis examples are determined by GPC (room temperature gel permeation chromatography) according to the following apparatus and measurement conditions. And calculated as a polyethylene glycol (or polyethylene oxide) equivalent value.
GPC device: Shodex (registered trademark) (GPC-101) manufactured by Showa Denko KK
Column: Shodex (registered trademark) manufactured by Showa Denko KK (series of KD803 and KD805)
Column temperature: 50 ° C
Eluent: N, N-dimethylformamide (as additives, lithium bromide-hydrate (LiBr · H ₂ O) 30 mmol / L, phosphoric acid / anhydrous crystal (o-phosphoric acid) 30 mmol / L, tetrahydrofuran (THF) ) 10ml / L)
Flow rate: 1.0 ml / min Standard sample for creating a calibration curve:
TSK standard polyethylene oxide (molecular weight: 900,000, 150,000, 100,000, 30,000) manufactured by Tosoh Corporation
Polyethylene glycol (molecular weight: about 12,000, 4,000, 1,000) manufactured by Polymer Laboratory.

[Measurement of film thickness]
The film thickness of the polyimide film was peeled off with a cutter knife, and the level difference was measured using a fully automatic fine shape measuring machine (ET4000A, manufactured by Kosaka Laboratory Ltd.) with a measuring force of 10 μN and a sweep speed of 0. .05 mm / sec.

[UV irradiation]
Ultraviolet rays were irradiated onto the polyimide film through a bandpass filter that passed light having a wavelength of about 254 nm using a high-pressure mercury lamp as a light source.
In addition, what multiplied the exposure time for the illumination intensity of the ultraviolet-ray on a polyimide film was computed as exposure amount (J / cm < ² >) on a polyimide film.
The illuminance of the ultraviolet rays was measured by attaching a Deep UV probe having a peak sensitivity at a wavelength of 253.7 nm to an illuminometer (MODEL 306 manufactured by OAI), and the obtained illuminance was 45 to 50 mW / cm ² .

[Measurement of contact angle]
The contact angle was measured using a fully automatic contact angle meter CA-W (Kyowa Interface Science Co., Ltd.) in a constant temperature and humidity environment (25 ° C. ± 2 ° C., 50% RH ± 5%).
In addition, the contact angle of propylene glycol monomethyl ether (PGME) is 3.0 to 3.5 μl in liquid volume, and after resting for 5 seconds, and the contact angle for pure water is 3 μl in liquid volume, after liquid landing. Measurements were taken after 5 seconds of rest.

<Synthesis Example 1>
Polymerization of polyimide precursor (PI-1) In a nitrogen stream, in a 50 mL four-necked flask, 1.8823 g (0.0094 mol) of 4,4′-diaminodiphenyl ether (hereinafter referred to as ODA) and 3,5-diaminobenzoic acid. After adding 0.3579 g (0.0006 mol) of 11- (perfluoro-n-hexyl) -n-undecyl (hereinafter APC11-6F) and dissolving in 23.58 g of N-methyl-2-pyrrolidone (hereinafter NMP) 1,2,3,4-cyclobutanetetracarboxylic dianhydride (hereinafter referred to as CBDA) 1.9219 g (0.0098 mol) was added, and this was stirred at 23 ° C. for 12 hours to conduct a polymerization reaction, and further diluted with NMP. By doing this, the 6 mass% solution of the polyimide precursor (PI-1) was obtained.
The number average molecular weight (Mn) and weight average molecular weight (M) of the obtained polyimide precursor (PI-1)
w) were Mn = 35,200 and Mw = 83,600, respectively.

<Synthesis Example 2>
Polymerization of polyimide (PI-2) In a 100 mL four-necked flask in a nitrogen stream, 3.3501 g (0.0167325 mol) of ODA, 2,2-bis (3-amino-4-methylphenyl) hexafluoropropane ( AMF) 1.6164 g (0.004462 mol) and APC11-6F 0.6965 g (0.0011155 mol) were added and dissolved in 49.44 g of NMP, and 3,4-dicarboxy-1,2,3, 4-Tetrahydro-1-naphthalene succinic dianhydride (hereinafter TDA) 6.681 g (0.02231 mol) was added, and this was stirred at 50 ° C. for 24 hours to carry out a polymerization reaction. The obtained polyamic acid solution was diluted to 8% by mass with NMP.
To 60 g of this solution, 22.1 g of acetic anhydride and 10.3 g of pyridine were added as an imidization catalyst and reacted at 50 ° C. for 3 hours to obtain a polyimide solution. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a white polyimide powder. It was confirmed that 90% or more of this polyimide powder was imidized by ¹ H-NMR. 4 g of this powder was dissolved in a mixed solvent of 30 g of γ-butyrolactone and 6 g of dipropylene glycol monomethyl ether to obtain a 10% by mass solution of polyimide (PI-2).
The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the obtained polyimide (PI-2) were Mn = 13,900 and Mw = 28,400, respectively.

<Synthesis Example 3>
Polymerization of polyimide (PI-3) In a 50 mL four-necked flask under a nitrogen stream, 2.7769 g (0.0095 mol) of 1,3-bis (4-aminophenoxy) benzene (hereinafter DA-4P), APC11- After adding 0.3122 g (0.0005 mol) of 6F and dissolving it in 21.96 g of NMP, bicyclo [3.3.0] -octane-2,4,6,8-tetracarboxylic dianhydride (hereinafter referred to as “NF”) (BODA) 2.402 g (0.0099 mol) was added, and this was stirred at 40 ° C. for 24 hours to carry out a polymerization reaction. The obtained polyamic acid solution was diluted to 8% by mass with NMP.
To 23 g of this solution, 8.5 g of acetic anhydride and 3.9 g of pyridine were added as imidation catalysts, and reacted at 100 ° C. for 3 hours to obtain a polyimide solution. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a white polyimide powder. It was confirmed that 90% or more of this polyimide powder was imidized by ¹ H-NMR. 3 g of this powder was dissolved in a mixed solvent of 22.5 g of γ-butyrolactone and 4.5 g of dipropylene glycol monomethyl ether to obtain a 10% by mass solution of polyimide (PI-3).
The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the obtained polyimide (PI-3) were Mn = 19,300 and Mw = 50,300, respectively.

<Synthesis Example 4>
Polymerization of polyimide precursor (PI-4) Under a nitrogen stream, 2.8234 g (0.0141 mol) of ODA and 0.5620 g (0.0009 mol) of APC11-6F were placed in a 100 mL four-necked flask, and 36.97 g of NMP. Then, 3.1084 g (0.01425 mol) of pyromellitic dianhydride (hereinafter PMDA) was added, this was stirred at 23 ° C. for 5 hours to conduct a polymerization reaction, and further diluted with NMP. An 8 mass% solution of polyimide precursor (PI-4) was obtained.
Number average molecular weight (Mn) and weight average molecular weight (M) of the obtained polyimide precursor (PI-4)
w) were Mn = 15,000 and Mw = 35,000, respectively.

<Comparative Synthesis Example 1>
Polymerization of polyimide precursor (PI-5) In a nitrogen stream, 15.065 g (0.040 mol) of 1-octadecyloxy-2,4-diaminobenzene (hereinafter APC18) was placed in a 200 mL four-necked flask, and NMP After dissolving in 127.6 g, 7.45 g (0.038 mol) of CBDA was added, this was stirred at 23 ° C. for 12 hours to conduct a polymerization reaction, and further diluted with NMP to obtain polyamic acid (PI-5 ) Was obtained.
The number average molecular weight (Mn) and weight average molecular weight (Mw) of the obtained polyamic acid (PI-5) were Mn = 16,000 and Mw = 48,000, respectively.

<Comparative Synthesis Example 2>
Polymerization of polyimide precursor (PI-6) In a nitrogen stream, 2.9856 g (0.0491 mol) of ODA and 0.0562 g (0.00009 mol) of APC11-6F were placed in a 50 mL four-necked flask, and NMP 24 After being dissolved in .93 g, CBDA 2.7946 g (0.01425 mol) was added, and this was stirred at 23 ° C. for 12 hours to conduct a polymerization reaction, and further diluted with NMP to obtain a polyimide precursor (PI-6). ) Was obtained.
The number average molecular weight (Mn) and weight average molecular weight (M) of the obtained polyimide precursor (PI-6)
w) were Mn = 14,200 and Mw = 28,500, respectively.

  A list of tetracarboxylic dianhydrides and diamines used in Synthesis Examples and Comparative Synthesis Examples is shown below.

<Example 1: UV sensitivity characteristic of polyimide film formed from PI-1 (contact angle of PGME)>
The solution of PI-1 prepared in Synthesis Example 1 was dropped onto a glass substrate with ITO (2.5 cm square, thickness 0.7 mm) with a syringe with a 0.2 μm pore filter and applied by spin coating. Thereafter, heat treatment was performed for 5 minutes on an 80 ° C. hot plate in the atmosphere to volatilize the organic solvent, and then baked for 30 minutes on a 180 ° C. hot plate to obtain a polyimide film having a film thickness of about 400 nm. The contact angle of PGME of this polyimide film was measured.
The polyimide film obtained in the same procedure was irradiated with ultraviolet rays at a dose of 6 J / cm ² , and the contact angle of PGME was measured.
Table 2 shows the measurement results of the contact angle of PGME.

<Examples 2 to 4, Comparative Example 1 and Comparative Example 2: UV sensitivity characteristics of polyimide films formed from PI-2 to PI-6 (PGME contact angle)>
Using a solution of PI-2 to PI-6 prepared in Synthesis Example 2 to Synthesis Example 4, Comparative Synthesis Example 1 and Comparative Synthesis Example 2, a polyimide film was prepared using the same procedure as in Example 1, and ultraviolet rays were not used. The contact angle of PGME after irradiation and UV 6 J / cm ² irradiation was measured.
Table 2 shows the measurement results of the contact angle of PGME.

As shown in Table 2 above, Examples 1 to 4 corresponding to the polyimide precursor or the cured film obtained from the polyimide according to the underlayer film composition for image formation of the present invention exhibit liquid repellency and are intimate by ultraviolet irradiation. The amount of change in water was 8 to 21 °, and a contact angle difference (5 ° or more) capable of image formation could be obtained.
On the other hand, the polyimide film obtained from PI-5 (Comparative Example 1) did not exhibit liquid repellency, and did not change to more hydrophilic even when irradiated with ultraviolet rays. Rather, the contact angle after UV irradiation increased slightly, so that it seems impossible to form an image.
In addition, although the polyimide film obtained from PI-6 (Comparative Example 2) showed liquid repellency, the change in hydrophilicity / hydrophobicity due to ultraviolet irradiation was as small as 3.7 °, and the contact angle difference capable of forming an image. Could not get.

<Examples 5 to 8: UV sensitivity characteristics of polyimide films formed from PI-1 to PI-4 (contact angle of water)>
Using the solutions of PI-1 to PI-4 prepared in Synthesis Example 1 to Synthesis Example 4 and using the same procedure as in Example 1, a polyimide film was produced, and after UV irradiation, irradiation with 40 J / cm ^{2 was} not performed. The contact angle of water was measured.
Table 3 shows the measurement results of the water contact angle.

As shown in Table 3, Examples 5 to 8 corresponding to the cured film obtained from the polyimide precursor or polyimide according to the underlayer film composition for image formation of the present invention obtain a large contact angle difference by ultraviolet irradiation. I was able to.
That is, it was shown that the image-forming underlayer film of the present invention can be patterned with an image-forming liquid having various surface tensions.

<Example 9: Relative permittivity of polyimide film formed from PI-2>
The solution of PI-2 prepared in Synthesis Example 2 was dropped onto a glass substrate with ITO (2.5 cm square, thickness 0.7 mm) with a syringe with a 0.2 μm pore filter and applied by spin coating. Thereafter, heating was performed for 5 minutes on an 80 ° C. hot plate in the atmosphere to volatilize the organic solvent, followed by baking for 60 minutes on a 180 ° C. hot plate to obtain a polyimide film having a thickness of about 400 nm.
Next, in order to obtain a good contact between the ITO electrode and the probe of the measuring device, a part of the polyimide film is scraped to expose the ITO, and then a diameter of 1.0 mm is formed on the polyimide film and on the ITO using a vacuum deposition apparatus. An aluminum electrode having a thickness of 100 nm was stacked. The vacuum deposition conditions at this time were room temperature, a degree of vacuum of 3 × 10 ⁻³ Pa or less, and an aluminum deposition rate of 0.3 nm / sec or less. In this way, electrodes were formed above and below the polyimide film, and a sample for evaluating the relative dielectric constant of the polyimide film was produced.

The relative dielectric constant of a sample for evaluating the relative dielectric constant of this polyimide film is 3.0, and it has a relative dielectric constant of 3.0 or more that can be used as a gate insulating film for organic transistors, despite having high water repellency. It has been found that it has secured and exhibits excellent properties.
In addition, the leakage current density when an electric field was applied at 1 MV / cm was 2 × 10 ⁻¹⁰ A / cm ² , and it was confirmed that there was no practical problem with respect to insulation as a gate insulating film for organic transistors.

  In this example, the relative dielectric constant of the polyimide film was obtained by measuring the capacitance using AG-4411B manufactured by Ando Electric Co., Ltd. The capacitance was measured at a frequency of 1 KHz in a nitrogen atmosphere. Further, HP4156C manufactured by Agilent Technologies was used for measurement of the leakage current density of the polyimide film.

<Comparative Example 3: Relative dielectric constant of polyimide film formed from PI-5>
A solution of PI-5 prepared in Comparative Synthesis Example 1 was used, and the baking temperature of the film was 250 ° C. in vacuum for 60 minutes, and the film thickness was 270 nm. The relative dielectric constant of the formed polyimide film was evaluated.
The polyimide film formed from PI-5 had a leakage current density of 1 × 10 ⁻¹⁰ A / cm ² or less, but a relative dielectric constant of 2.7. The relative dielectric constant is low for use as a gate insulating film, and even if performance as an image forming lower layer film is obtained, it cannot be used as a gate insulating film.

<Synthesis Example 5>
Polymerization of polyimide precursor (PI-7) In a nitrogen stream, ODA 1.7621 g (0.0088 mol) and hereafter APC11-6F 0.7158 g (0.0012 mol) were placed in a 100 mL four-necked flask, and NMP24 After being dissolved in .93 g, 1.9219 g (0.0098 mol) of CBDA was added, this was stirred at 23 ° C. for 12 hours to carry out a polymerization reaction, and further diluted with NMP to obtain a polyimide precursor (PI-7 ) Was obtained.
The number average molecular weight (Mn) and weight average molecular weight (M) of the obtained polyimide precursor (PI-7)
w) were Mn = 29,630 and Mw = 67,400, respectively.

<Synthesis Example 6>
Polymerization of polyimide (PI-8) Under a nitrogen stream, in a 100 mL four-necked flask, ODA 3.4366 g (0.01716 mol), AMF 1.6151 g (0.004458 mol), APC11-6F 0.4176 g (0. 000669 mol) was added and dissolved in 48.65 g of NMP, 6.6927 g (0.02229 mol) of TDA was added, and this was stirred at 50 ° C. for 24 hours to conduct a polymerization reaction. The obtained polyamic acid solution was diluted to 8% by mass with NMP.
Acetic anhydride 22.2g and pyridine 10.3g were added to 148g of this solution as an imidation catalyst, and it was made to react at 50 degreeC for 3 hours, and the polyimide solution was obtained. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a white polyimide powder. It was confirmed that 90% or more of this polyimide powder was imidized by ¹ H-NMR. 4 g of this powder was dissolved in a mixed solvent of 30 g of γ-butyrolactone and 6 g of dipropylene glycol monomethyl ether to obtain a 10% by mass solution of polyimide (PI-8).
The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the obtained polyimide (PI-8) were Mn = 15,300 and Mw = 31,500, respectively.

<Synthesis Example 7>
Polymerization of polyimide precursor (PI-9) In a 100 mL four-necked flask in a nitrogen stream, ODA 3.5683 g (0.01782 mol), 1- (4-perfluorooctyl) phenoxy-2,4-diaminobenzene (Hereinafter DA-1) 0.1113 g (0.00018 mol) was added and dissolved in 27.99 g of NMP, then 3.3182 g (0.01692 mol) of CBDA was added, and this was stirred at 23 ° C. for 12 hours. A polymerization reaction was carried out and further diluted with NMP to obtain an 8% by mass solution of a polyimide precursor (PI-9).
Number average molecular weight (Mn) and weight average molecular weight (M) of the obtained polyimide precursor (PI-9)
w) were Mn = 31,500 and Mw = 67,200, respectively.

<Synthesis Example 8>
Polymerization of polyimide precursor (PI-10) Under a nitrogen stream, ODA 1.9624 g (0.0098 mol) and DA-1 0.1237 g (0.0002 mol) were placed in a 100 mL four-necked flask, and NMP 15 After dissolving in 0.72 g, CBDA 1.8434 g (0.0094 mol) was added, this was stirred at 23 ° C. for 12 hours to conduct a polymerization reaction, and further diluted with NMP to obtain a polyimide precursor (PI-10 8% by mass solution was obtained.
The number average molecular weight (Mn) and weight average molecular weight (M) of the obtained polyimide precursor (PI-10)
w) were Mn = 31,200 and Mw = 68,100, respectively.

<Synthesis Example 9>
Polymerization of polyimide (PI-11) In a 100 mL four-necked flask under nitrogen flow, ODA 5.887 g (0.0294 mol) and DA-1 0.371 g (0.0006 mol) were placed, and NMP 60.88 g After being dissolved in TDA, 8.9931 g (0.03 mol) of TDA was added, and this was stirred at 50 ° C. for 24 hours to carry out a polymerization reaction. The obtained polyamic acid solution was diluted to 8% by mass with NMP.
To 170 g of this solution, 27.8 g of acetic anhydride and 12.9 g of pyridine were added as imidization catalysts, and reacted at 50 ° C. for 3 hours to obtain a polyimide solution. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a white polyimide powder. It was confirmed that 90% or more of this polyimide powder was imidized by ¹ H-NMR. 4 g of this powder was dissolved in a mixed solvent of 30 g of γ-butyrolactone and 6 g of dipropylene glycol monomethyl ether to obtain a 10% by mass solution of polyimide (PI-11).
The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the obtained polyimide (PI-11) were Mn = 30,470 and Mw = 66,900, respectively.

<Synthesis Example 10>
Polymerization of polyimide (PI-12) Under a nitrogen stream, DA-3 8.0458 g (0.0196 mol) and DA-1 0.2473 g (0.0004 mol) were placed in a 100 mL four-necked flask, and NMP 56 After dissolving in 0.7 g, 5.853 g (0.0196 mol) of TDA was added, and this was stirred at 50 ° C. for 24 hours to conduct a polymerization reaction. The obtained polyamic acid solution was diluted to 8% by mass with NMP.
17.7 g of acetic anhydride and 8.9 g of pyridine were added to 177 g of this solution as an imidation catalyst and reacted at 50 ° C. for 3 hours to obtain a polyimide solution. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a white polyimide powder. It was confirmed that 90% or more of this polyimide powder was imidized by ¹ H-NMR. 4 g of this powder was dissolved in a mixed solvent of 52.67 g of γ-butyrolactone and 10 g of dipropylene glycol monomethyl ether to obtain a 6% by mass solution of polyimide (PI-12).
The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the obtained polyimide (PI-12) were Mn = 19,700 and Mw = 47,960, respectively.

<Synthesis Example 11>
Polymerization of polyimide (PI-13) In a 100 mL four-necked flask under nitrogen flow, 5.176 g (0.01261 mol) of DA-3 and 0.2411 g (0.00039 mol) of DA-1 were placed, and NMP 36 After dissolving in 0.77 g, 5.176 g (0.012571 mol) of TDA was added, and this was stirred at 50 ° C. for 24 hours to conduct a polymerization reaction. The obtained polyamic acid solution was diluted to 8% by mass with NMP.
To 130 g of this solution, 11.6 g of acetic anhydride and 5.4 g of pyridine were added as an imidization catalyst and reacted at 50 ° C. for 3 hours to obtain a polyimide solution. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a white polyimide powder. It was confirmed that 90% or more of this polyimide powder was imidized by ¹ H-NMR. 4 g of this powder was dissolved in a mixed solvent of 52.67 g of γ-butyrolactone and 10 g of dipropylene glycol monomethyl ether to obtain a 6 mass% solution of polyimide (PI-13).
The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the obtained polyimide (PI-13) were Mn = 20,970 and Mw = 51,220, respectively.

<Comparative Synthesis Example 3>
Polymerization of polyimide precursor (PI-14) In a nitrogen stream, DA-3 1.0673 g (0.0026 mol) and DA-1 0.8656 g (0.0014 mol) were placed in a 50 mL four-necked flask, After dissolving in 15.31 g of NMP, 0.7688 g (0.00392 mol) of CBDA was added, and this was stirred at 23 ° C. for 12 hours to conduct a polymerization reaction, and further diluted with NMP to obtain a polyimide precursor (PI A 14 mass% solution of -14) was obtained.
The number average molecular weight (Mn) and weight average molecular weight (M) of the obtained polyimide precursor (PI-14)
w) were Mn = 20,130 and Mw = 48,280, respectively.

  A list of tetracarboxylic dianhydrides and diamines used in Synthesis Examples 5 to 11 and Comparative Synthesis Example 3 is shown below. The numbers in the table are molar ratios when the addition amounts of tetracarboxylic dianhydride and diamine are each 100.

<Synthesis Example 12>
Polymerization of polyimide (PI-15) In a 200 mL four-necked flask under a nitrogen stream, 4.86 g (0.045 mol) of p-phenylenediamine, 1.74 g of 4-hexadecyloxy-1,3-diaminobenzene ( 0.005 mol) was added and dissolved in 122.5 g of NMP, then 15.01 g (0.05 mol) of TDA was added, and this was stirred at room temperature for 10 hours to conduct a polymerization reaction. The obtained polyamic acid solution was diluted to 8% by mass with NMP.
To 50 g of this solution, 10.8 g of acetic anhydride and 5.0 g of pyridine were added as imidation catalysts and reacted at 50 ° C. for 3 hours to obtain a polyimide solution. This solution was put into a large amount of methanol, and the resulting white precipitate was filtered and dried to obtain a white polyimide powder. It was confirmed that 90% or more of this polyimide powder was imidized by ¹ H-NMR. 4 g of this powder was dissolved in a mixed solvent of 52.67 g of γ-butyrolactone and 10 g of dipropylene glycol monomethyl ether to obtain a 6 mass% solution of polyimide (PI-15).
The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the obtained polyimide (PI-15) were Mn = 18,000 and Mw = 54,000, respectively.

<Example 10: Observation of change in wettability of silver fine particle dispersion (W4A) of polyimide film formed from PI-1>
The solution of PI-1 prepared in Synthesis Example 1 was dropped onto a glass substrate with ITO (2.5 cm square, thickness 0.7 mm) with a syringe with a 0.2 μm pore filter and applied by spin coating. Thereafter, heat treatment was performed for 5 minutes on an 80 ° C. hot plate in the atmosphere to volatilize the organic solvent, and then baked for 30 minutes on a 180 ° C. hot plate to obtain a polyimide film having a film thickness of about 400 nm. When 3 μl of a silver fine particle dispersion (product name: W4A, manufactured by Sumitomo Electric Industries) was dropped on this polyimide film, the polyimide film showed liquid repellency with respect to the silver fine particle dispersion.
The polyimide film obtained in the same procedure was irradiated with ultraviolet rays at a dose of 6 J / cm ² , and 3 μl of silver fine particle dispersion was dropped onto this polyimide film. The polyimide film was lyophilic with respect to the silver fine particle dispersion. Showed sex.
The polyimide film obtained from PI-1 was capable of controlling the liquid repellency and lyophilicity of the silver fine particle dispersion by ultraviolet irradiation.

<Examples 11 to 19, Comparative Examples 4 to 6: Observation of change in wettability of polyimide films formed from PI-1 to PI-3, PI-5 to PI-13>
Using a solution of PI-2, PI-3, PI-5 to PI-14, a polyimide film was prepared using the same procedure as in Example 1, and the polyimide film was not irradiated with ultraviolet rays and irradiated with ultraviolet rays of 6 J / cm ^2. The liquid repellency and lyophilicity to the silver fine particle dispersion were observed. The results are shown in Table 5.

* 1: The numbers in parentheses indicate the mole fraction of each amine in the total diamine.
* 2: When the polyimide film is irradiated with 6 J / cm ^{2 of} ultraviolet light, the polyimide film changes from liquid repellency to lyophilic, and the wettability changes. .
As shown in Table 5 above, Examples 10 to 19 corresponding to the polyimide precursor or the cured film obtained from the polyimide according to the underlayer film composition for image formation of the present invention are wettability to the silver fine particle dispersion by ultraviolet irradiation. There was a change. It is possible to form an image using a change in wettability difference.
On the other hand, the polyimide films obtained from PI-5 and PI-6 (Comparative Example 4 and Comparative Example 5) did not change wettability even when irradiated with ultraviolet rays.

[About polymer blends]
<Composition Preparation Example 1: Preparation of image-forming underlayer film composition>
8.5 g of a 6 wt% solution of polyimide (PI-15) prepared in Synthesis Example 12 and 1.5 g of a 6 wt% solution of polyimide (PI-12) prepared in Synthesis Example 10 were mixed and stirred at room temperature for 6 hours. And composition A was obtained.

<Composition Preparation Example 2: Preparation of image-forming underlayer film composition>
9 g of a 6 wt% solution of polyimide (PI-15) prepared in Synthesis Example 12 and 1 g of a 6 wt% solution of polyimide (PI-13) prepared in Synthesis Example 11 were mixed together and stirred at room temperature for 6 hours. B was obtained.

<Composition Preparation Example 3: Preparation of image-forming underlayer film composition>
8.5 g of a 6 wt% solution of polyimide (PI-15) prepared in Synthesis Example 12 and 1.5 g of a 6 wt% solution of polyimide (PI-13) prepared in Synthesis Example 11 were mixed and stirred at room temperature for 6 hours. And composition C was obtained.

<Composition Preparation Example 4: Preparation of image-forming underlayer film composition>
8 g of a 6 wt% solution of polyimide (PI-15) prepared in Synthesis Example 12 and 2 g of a 6 wt% solution of polyimide (PI-13) prepared in Synthesis Example 11 were mixed together and stirred at room temperature for 6 hours. D was obtained.

<Composition Preparation Example 5: Preparation of image-forming underlayer film composition>
7.5 g of a 6 wt% solution of polyimide (PI-15) prepared in Synthesis Example 12 and 2.5 g of a 6 wt% solution of polyimide (PI-13) prepared in Synthesis Example 11 were mixed and stirred at room temperature for 6 hours. And composition E was obtained.

<Composition Preparation Example 6: Preparation of image-forming underlayer film composition>
7 g of a 6 wt% solution of polyimide (PI-15) prepared in Synthesis Example 12 and 3 g of a 6 wt% solution of polyimide (PI-13) prepared in Synthesis Example 11 were mixed and stirred at room temperature for 6 hours to obtain a composition. F was obtained.

<Composition Preparation Example 7: Preparation of image-forming underlayer film composition>
9 g of a 6 wt% solution of polyimide (PI-15) prepared in Synthesis Example 12 and 1 g of a 6 wt% solution of polyimide (PI-14) prepared in Comparative Example Synthesis Example 3 were mixed and stirred at room temperature for 6 hours. Composition G was obtained.

<Example 20: Patterning property of electrode>
The composition A prepared in Preparation Example 1 of the composition was dropped onto a glass substrate with ITO (2.5 cm square, thickness 0.7 mm) with a syringe with a 0.2 μm pore filter and applied by spin coating. Thereafter, heat treatment was performed for 5 minutes on a hot plate at 80 ° C. in the atmosphere to volatilize the organic solvent, followed by baking for 30 minutes on a hot plate at 180 ° C. to obtain a polyimide film having a thickness of about 450 nm. The polyimide film was irradiated with ultraviolet rays 6 J / cm ² in a pattern through a photomask. Subsequently, when a very small amount of the silver fine particle dispersion was dropped onto the ultraviolet irradiation part, the ultraviolet irradiation part of the polyimide film showed lyophilicity. Then, it baked for 60 minutes with a 180 degreeC hotplate, and formed the 50-nm-thick silver electrode.
A photomicrograph of this silver electrode is shown in FIG.

<Example 21 to Example 27: Patterning property of electrode>
A polyimide film was formed using the same procedure as in Example 20 except that the solutions of Composition B to Composition F and PI-12 to PI-13 were used, and a silver electrode was prepared using a silver fine particle dispersion. Formed. It was possible to form silver electrodes with an electrode spacing of 10 μm with all polyimide films.

<Comparative Example 7>
A polyimide film was formed using the same procedure as in Example 20 except that the composition G solution was used, and a silver electrode dispersion was attempted using a silver fine particle dispersion. The polyimide film obtained from the solution of the composition G showed water repellency at the ultraviolet irradiation part, and the target silver electrode could not be formed (FIG. 3).

<Comparative Example 8 to Comparative Example 9>
A polyimide film was formed using the same procedure as in Example 20 except that a solution of PI-5 to PI-6 was used, and an attempt was made to form a silver electrode using a silver fine particle dispersion. In the polyimide film obtained from the PI-5 to PI-6 solution, an electrode was formed regardless of whether there was ultraviolet irradiation, and the target silver electrode could not be formed.

<Example 28: Measurement of relative permittivity of specific resistance>
Composition A prepared in Composition Solution Preparation Example 1 was dropped onto a glass substrate with ITO (2.5 cm square, thickness 0.7 mm) with a syringe with a 0.2 μm pore filter and applied by spin coating. Thereafter, the mixture was heat-treated in an air at 80 ° C. for 5 minutes to volatilize the organic solvent. Subsequently, it was baked on a hot plate at 180 ° C. for 30 minutes to obtain a polyimide film having a film thickness of about 450 nm.
Next, using a vacuum vapor deposition apparatus, an aluminum electrode having a diameter of 1.0 mm to 2.0 mm and a thickness of 100 nm is laminated on the polyimide film, and a sample for evaluating the insulating property of the polyimide film in which electrodes are placed on the upper and lower sides of the polyimide film. Was made. The vacuum deposition conditions at this time were room temperature, a degree of vacuum of 3 × 10 ⁻³ Pa or less, and an aluminum deposition rate of 0.5 nm / sec or less.
Using the sample, current-voltage characteristics were measured in an air atmosphere at room temperature and humidity of 45% ± 5%. The voltage was applied to the aluminum electrode side from 0 V to 80 V with a holding time of 3 seconds every 2 V step, and the specific resistance was obtained from the current value when the electric field was 1 MV / cm. Table 7 shows the measurement results of the specific resistance and the relative dielectric constant.

<Example 29 to Example 35>
A polyimide film was formed using the same procedure as in Example 28 except that the solutions of Composition B to Composition F and PI-12 to PI-13 were used, and the specific resistance and dielectric constant were measured. .
The results are shown in Table 7.

<Example 36: Preparation of organic transistor>
On the silver electrode obtained in Example 20, poly (3-hexylthiophene-2,5-diyl) (obtained from Merck Ltd., hereinafter abbreviated as P3HT) was dissolved in xylene at a concentration of 2% by mass. A coating solution of P3HT was prepared, and the coating solution was coated on the polyimide film described above using a spin coating method in a nitrogen atmosphere having an oxygen concentration of 0.5 ppm or less.
Then, in order to volatilize a solvent completely, it heat-processed for 100 minutes at 100 degreeC in the vacuum state, the semiconductor layer was formed, and the organic thin-film transistor was completed.
The electrical characteristics of the organic thin film transistor obtained as described above were evaluated by measuring the change of the drain current with respect to the gate voltage.
Specifically, after the source / drain voltage (V _D ) is set to −40 V and the gate voltage (V _G ) is changed from +30 V to −30 V in 2 V steps, the voltage is maintained for 1 second until the current is sufficiently stabilized. The value was recorded as the measured drain current. For the measurement, a semiconductor parameter analyzer HP4156C (manufactured by Agilent Technologies) was used.
When the gate voltage was applied negatively, a large increase in drain current was observed, confirming that P3HT was operating as a p-type semiconductor (FIG. 4).
Next, the relationship between the drain current and the drain voltage when the gate voltage (VG) was changed from + 20V to −30V in 10V steps was measured, and it was confirmed that the organic transistor was operating normally (FIG. 5). ).

In general, the drain current _ID in the saturated state can be expressed by the following formula. That is, the mobility μ of the organic semiconductor can be obtained from the slope of the graph when the square root of the absolute value of the drain current I _D is plotted on the vertical axis and the gate voltage V _G is plotted on the horizontal axis.
I _D = WCμ (V _G −V _T ) ² / 2L
In the above equation, W is the channel width of the transistor, L is the channel length of the transistor, C is the capacitance of the gate insulating film, V _T is the threshold voltage of the transistor, and μ is the mobility. When the mobility μ of P3HT was calculated based on this formula, it was 2 × 10 ⁻³ cm ² / Vs. The threshold voltage was 16 V, and the ratio between the on state and the off state (on / off ratio) was on the order of 10 ² (Table 8).
The organic thin-film transistor electrical characteristics were quickly transferred to a vacuum (vacuum degree of 5 × 10 ⁻² Pa or less) after the device was completed in order to remove the influence of ambient humidity and active substances, and left for about 30 minutes. The measurement was carried out while maintaining a vacuum of 5 × 10 ⁻² Pa or less.

<Example 37: Organic transistor>
An organic transistor was produced using the same procedure as in Example 36 except that the silver electrode obtained in Example 21 was used.

<Example 38: Organic transistor>
An organic transistor was produced using the same procedure as in Example 36 except that the silver electrode obtained in Example 27 was used.

It has been shown that the polyimide of the present invention can be subjected to electrode patterning using a difference in hydrophilicity / hydrophobicity and can produce an organic transistor having a channel length of 10 μm.
Furthermore, it has a high insulating property of 10 ¹⁵ Ωcm or more and a relative dielectric constant of 3.0 or more, and has high performance not only as a lower layer film for image formation but also as a gate insulating film for organic transistors. It has been shown.

  From the above results, the cured film obtained from the lower layer film composition for image formation of the present invention containing a polyimide precursor containing a fluoroalkyl group and / or a polyimide obtained from the polyimide precursor has extremely high water repellency, It was shown that it is useful when used as a gate insulating film because of its high relative dielectric constant.

It is a schematic sectional drawing which shows the structure of the organic transistor which has the lower film for image forms of this invention. Example of patterning of silver fine particle dispersion obtained in Example 20 Patterning example of silver fine particle dispersion obtained in Comparative Example 7 In Example 36, it is a graph which shows the relationship between the drain current (Drain Current) and gate voltage (Gate Voltage) of the organic transistor which made the polyimide film obtained from the composition A the lower layer and gate insulating film for image formation. In Example 36, it is a graph which shows the relationship between the drain current (Drain Current) and drain voltage (Drain Voltage) of the organic transistor which used the polyimide film obtained from the composition A as the image formation lower layer and gate insulating film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Gate electrode 3 ... Electrode forming lower layer film and gate insulating film 4 ... Source electrode , Drain electrode 5... Semiconductor layer

Claims (5)

At least one compound including images forming a polyimide precursor and the polyimide precursor selected from the group consisting of polyimide obtained by cyclodehydration including the following equation (1) and the structural unit represented by the formula (1a) A gate insulating film for an organic transistor obtained by using the underlayer film composition for an organic transistor .
(In the formula, A represents a tetravalent organic group, B ¹ represents at least one divalent organic group represented by the following formula (2), B ² represents a divalent organic group, R ¹ , R ² , R ^1a and R ^2a each independently represents a hydrogen atom or a monovalent organic group, n is the total number of moles of the structural unit represented by the formula (1), and m is the formula (1a ), And n and m each represent a positive integer and satisfy 0.01 ≦ n / (n + m) ≦ 0.3.)
(In the formula, X ₁ represents a single bond, —O—, —COO—, —OCO—, —CONH—, —CH ₂ O—, and X ₂ represents a divalent organic compound having 3 to 18 carbon atoms. And R ³ represents a perfluoroalkyl group having 2 to 12 carbon atoms.) ^{2. The} gate insulating film for an organic transistor according to claim 1, wherein in the formula (1a), B ² is at least one group selected from the group consisting of the following formulas (3) to (5).
(In the formula, each Y ¹ independently represents a single bond, an ether bond, an ester bond, a thioether bond, an amide bond, an alkylene group or a carbon atom number which may have a branched structure having 1 to 3 carbon atoms. Represents an alkylenedioxo group which may have 1 to 3 branched structures, Y ² represents a single bond, an ether bond, an ester bond, a thioether bond, an amide bond, and R ⁴ each independently represents hydrogen Represents an atom, a methyl group, an ethyl group, or a trifluoromethyl group; R ⁵ represents a hydrogen atom, a methyl group, or a trifluoromethyl group; R ⁶ represents a methylene group or an ethylene group; Represents 0 or 1) In the formula (1) and the formula (1a), the tetravalent organic group represented by A is at least one group selected from the group consisting of the following formulas (6) to (11). The gate insulating film for organic transistors according to claim 2.
(In the formula, R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each independently represents a hydrogen atom, a fluorine atom or a hydrocarbon group having 1 to 4 carbon atoms.) The polyimide precursor containing the structural unit represented by the formula (1) and the formula (1a) and the polyimide obtained by dehydrating and ring-closing the polyimide precursor are tetracarboxylic dianhydrides represented by the following formula (16) The organic transistor as described in any one of Claims 1 thru | or 3 which is the polyimide precursor and polyimide which are obtained by making a product react with the diamine component represented by following formula (17) and (18) Gate insulation film .
(In the formula, A, B ¹ and B ² have the same definitions as those in the formula (1) and the formula (1a)). The organic transistor obtained using the gate insulating film for organic transistors of any one of Claim 1 thru | or 4 .