JP5699507B2 - Inkjet ink - Google Patents

Description

  The present invention relates to an ink jet ink containing an amic acid derivative having a specific structure or an imidized product thereof. More specifically, for example, an ink-jet ink used for forming an insulating film layer in the production of electronic components, a polyimide film formed using the ink-jet ink, a film substrate and a silicon wafer substrate on which the polyimide film is formed, The present invention also relates to an electronic component having the film substrate or the silicon wafer substrate.

  Polyimide is widely used in the field of electronic communication because it is excellent in heat resistance and electrical insulation (see, for example, Patent Documents 1 to 3). In the case of using polyimide as a desired pattern film, conventionally, it has been common to form a pattern using etching or photosensitive polyimide. However, pattern formation requires a large amount of chemicals such as a photoresist, a developer, an etching solution, and a stripping solution, and a complicated process. Therefore, in recent years, a method for forming a desired polyimide pattern film by inkjet has been studied.

  Various ink-jet inks have been proposed (see, for example, Patent Documents 4 to 5). In order to eject and print as ink-jet inks, various parameters such as ink viscosity, surface tension, and solvent boiling point are set. Must be optimized.

  Regarding the viscosity, generally, it is required to have a low viscosity of about 1 to 50 mPa · s at the discharge temperature (the temperature of the ink at the time of discharge). In particular, in the case of piezo-type ink jet printing, since the discharge pressure of the piezoelectric element is small, ink may not be able to be discharged when the viscosity is high.

  The surface tension is preferably adjusted to a range of 20 to 70 mN / m, and more preferably adjusted to a range of 20 to 40 mN / m. If the surface tension is too low, the ink spreads immediately after it is ejected from the nozzles of the printer head, and good droplets may not be formed. On the other hand, if the surface tension is too high, it becomes impossible to form a meniscus, which may make ejection impossible.

  The boiling point of the solvent is preferably 100 to 300 ° C, more preferably 150 to 250 ° C. If the boiling point is too low, the solvent in the ink at the nozzle portion of the printer head will evaporate particularly when the ink is heated and ejected. As a result, the viscosity of the ink changes, and the ink cannot be ejected, or the ink components may solidify. On the other hand, if the boiling point is too high, the drying of the ink after printing is too slow, and the printing pattern may deteriorate.

  Various polyimide-based ink-jet inks have been proposed that contain polyimide and those that contain polyamic acid that becomes polyimide by heat treatment (see, for example, Patent Documents 6 to 10).

  In the polyimide-based ink-jet ink, in addition to the necessary properties such as the viscosity, surface tension, and boiling point of the solvent as the ink-jet ink described above, the function and properties as a polyimide when a film is formed are important. For example, electrical characteristics such as volume resistivity, withstand voltage, dielectric constant and dielectric loss, mechanical properties such as bending test, elastic modulus and tensile elongation, chemical stability such as acid resistance, alkali resistance and plating resistance Various characteristics such as thermal characteristics such as thermal decomposition temperature, glass transition temperature, and coefficient of thermal expansion are required. Furthermore, secondary problems such as adhesion to the substrate, warpage caused by shrinkage during film formation, and migration resistance are also cited.

  Originally, polyimide has been widely used for electronic materials as a resin excellent in the above characteristics. However, due to limitations when designing materials as inkjet ink, the functions and properties of polyimide are well balanced and fully expressed. It was extremely difficult. In addition, the function and characteristics of polyimide when forming a film vary depending on the application, especially for flexible printed wiring boards using film substrates, rigid printed wiring boards using glass-epoxy substrates, and silicon wafer substrates. In the semiconductor application used, the adhesion between the substrate and the polyimide film is a major issue.

  Methods for controlling the functions and properties of polyimide films include: a method for optimizing the structure of raw material tetracarboxylic acid derivatives and diamine derivatives, a method for optimizing the structure of polymers in copolymers, polymer blends, etc., a polyimide precursor Various methods such as a method for optimizing the imidization ratio of the resin and the addition of a crosslinking agent have been studied.

  As a specific example of optimizing the structure of a raw material tetracarboxylic acid derivative to express functions and properties, Patent Document 11 includes a phosphorus-containing polyesterimide precursor produced using a tetracarboxylic acid anhydride having a specific structure or It is disclosed that even if the phosphorus-containing polyesterimide is thinned, it retains the same heat and flame resistance as before and has good thermal diffusivity.

  However, the adhesiveness between the substrate and the polyimide film is not disclosed at all, and further, it does not take into consideration necessary properties such as viscosity, surface tension, and boiling point of the solvent as an inkjet ink.

JP 2000-039714 A JP 2003-238683 A JP 2004-094118 A JP 2003-213165 A JP 2006-131730 A JP 2009-35700 A International Publication No. 2008/123190 Pamphlet JP 2009-144138 A International Publication No. 2008/059986 Pamphlet JP 2009-203440 A JP 2009-221309 A

  An object of the present invention is to provide an ink-jet ink capable of forming a polyimide film that exhibits good adhesion to a substrate, particularly in printed wiring board applications or semiconductor applications.

  The present invention also relates to an inkjet ink comprising an imide compound that can use a solvent that does not decrease the durability of the inkjet head in an inkjet ink in which parameters such as viscosity, surface tension, and boiling point of the solvent are optimized for inkjet printing. It is also an issue to provide.

  The present inventors diligently studied to solve the above problems. As a result, the inventors have found that the above-described problems can be solved by using an ink jet ink containing an amic acid derivative having a specific structure or an imidized product thereof, and completed the present invention. That is, the present invention is as follows.

  [1] An inkjet ink containing at least one compound (A) selected from the group consisting of an amide acid derivative (A1) having a skeleton represented by formula (1) and an imidized product (A2) thereof.

In the formula, R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen or alkyl having 1 to 10 carbons.

  [2] The inkjet ink according to [1], wherein the compound (A) is a compound obtained by using an acid anhydride represented by the formula (2-1) or (2-2).

式中、Ｒ¹、Ｒ²、Ｒ³およびＲ⁴は、それぞれ独立に水素または炭素数１〜１０のアルキルであり、Ｒ⁵は単結合、炭素または炭素数１〜５０の有機基であり、ｍは１または２であり、ｎは１または２である。

In the formula, R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen or alkyl having 1 to 10 carbon atoms, R ⁵ is a single bond, carbon or an organic group having 1 to 50 carbon atoms, m is 1 or 2, and n is 1 or 2.

  [3] The compound (A) is a compound obtained by using at least one selected from tetracarboxylic dianhydrides represented by the formulas (3) to (5): [1] or [2] The ink for inkjet described.

  [4] The compound (A) according to [1] or [2], wherein the compound (A) is a compound obtained using at least one selected from dicarboxylic anhydrides represented by formulas (6) to (7). Ink for inkjet.

［５］アミド酸誘導体（Ａ１）が、式（８）で表される構成単位と、式（８−１）および（８−２）で表される分子末端基からなる群より選ばれる少なくとも１種の分子末端基とを有する化合物ならびに式（９）〜（１２）で表される化合物からなる群より選ばれる少なくとも１種である［１］〜［４］のいずれか１つに記載のインクジェット用インク。

[5] At least one selected from the group consisting of the structural unit represented by the formula (8) and the molecular end groups represented by the formulas (8-1) and (8-2) as the amic acid derivative (A1). The inkjet according to any one of [1] to [4], which is at least one selected from the group consisting of a compound having a molecular end group and a compound represented by formulas (9) to (12) For ink.

  In the formula, X is carbon or a tetravalent organic group having 2 to 100 carbon atoms, Y is a divalent organic group having 1 to 100 carbon atoms, and Z is a monovalent organic group having 1 to 100 carbon atoms. And at least one of X, Y and Z has a skeleton represented by the formula (1), X ′ is independently a divalent organic group having 1 to 100 carbon atoms, and Y ′ is independently And a monovalent organic group having 1 to 100 carbon atoms.

  [6] In formulas (8-1), (8-2), and (9) to (12), X ′ is independently a divalent organic group having 2 to 100 carbon atoms and having an unsaturated hydrocarbon structure, It is a divalent organic group represented by the formula (a), and Y ′ independently represents a monovalent organic group having 2 to 100 carbon atoms having an unsaturated hydrocarbon structure, or 1 represented by the formula (b) The inkjet ink according to [5], which is a valent organic group.

  In the formula, R is independently hydrogen, alkyl having 1 to 20 carbons or alkoxy having 1 to 20 carbons, R ′ is a trivalent organic group having 1 to 20 carbons, and R ″ is a carbon number. 1 to 20 divalent organic groups.

  [7] The inkjet ink according to any one of [1] to [6], further including a solvent (B).

  [8] Solvent (B) is ethanol, ethylene glycol, propylene glycol, glycerin, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, ethylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether Acetate, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol butyl methyl ether, diethyl Glycol monoethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, triethylene glycol divinyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, Dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol dimethyl ether, tetramethylene glycol monovinyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl lactate, benzoate Acid methyl, ethyl benzoate, anisole, cyclohexanone, γ-butyrolactone, 1,3-dioxolane, 1,4-dioxane, 2-pyrrolidone, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1-butyl 2-pyrrolidone, 1-vinyl-2-pyrrolidone, 1- (2-hydroxyethyl) -2-pyrrolidone, 1-acetyl-2-pyrrolidone, N-methyl-ε-caprolactam, N, N-dimethylacetamide, N The inkjet ink according to [7], which is at least one selected from the group consisting of N, diethylacetamide, N, N-dimethylpropionamide, and 1,3-dimethyl-2-imidazolidinone.

  [9] The ink-jet ink according to any one of [1] to [8], which contains the compound (A) in an amount of 5 to 95 parts by weight with respect to 100 parts by weight of the ink-jet ink.

  [10] A polyimide film formed using the ink-jet ink according to any one of [1] to [9].

  [11] The polyimide film according to [10], which has a pattern shape.

  [12] A step of applying the ink-jet ink according to any one of [1] to [9] onto a substrate by an ink-jet coating method to form a coating film; A method of forming a polyimide film.

  [13] A film substrate in which the polyimide film according to [10] or [11] is formed on a substrate.

  [14] An electronic component having the film substrate according to [13].

  [15] A silicon wafer substrate in which the polyimide film according to [10] or [11] is formed on a substrate.

  [16] An electronic component having the silicon wafer substrate according to [15].

  If the ink-jet ink of the present invention in which parameters such as viscosity, surface tension, and boiling point of the solvent are optimized for ink-jet printing is used, it can be suitably used for ink-jet printing. Moreover, the polyimide film which shows favorable adhesiveness with respect to various board | substrates can be formed when it is set as a coating film using the inkjet ink of this invention. In addition, if the inkjet ink of the present invention is used to form a patterned polyimide film, it is only necessary to draw on a necessary portion by inkjet printing, and it is not necessary to use a photomask or the like. Compared to other methods such as the above, the amount of material used can be significantly reduced, the number of steps required for production can be reduced, and mass production of various varieties is possible. In addition, since the inkjet ink of the present invention contains an imide compound, it is also possible to provide an inkjet ink using a solvent that does not reduce the durability of the inkjet head.

The schematic diagram of the evaluation sample produced in order to measure adhesive strength in an Example.

  Hereinafter, the inkjet ink according to the present invention, a polyimide film formed using the inkjet ink, a film substrate and a silicon wafer substrate on which the polyimide film is formed, and an electron having the film substrate or the silicon wafer substrate The parts will be described in detail.

[Inkjet ink]
The inkjet ink of the present invention is selected from the group consisting of an amic acid derivative (A1) having a skeleton represented by formula (1) (hereinafter also referred to as “skeleton (1)”) or an imidized product (A2) thereof. Contains at least one compound (A). The ink-jet ink of the present invention preferably further contains a solvent (B), and may contain other additives as necessary. The ink-jet ink of the present invention may be colored or colorless.

式（１）中、Ｒ¹、Ｒ²、Ｒ³およびＲ⁴は、それぞれ独立に水素または炭素数１〜１０のアルキルである。

In the formula (1), R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen or alkyl having 1 to 10 carbons.

<1. Compound (A)>
The compound (A) can be synthesized using an acid anhydride having a skeleton (1) and / or an amine having a skeleton (1) (hereinafter also referred to as “raw material having a skeleton (1)”). By synthesizing using a raw material having such a skeleton (1), the skeleton (1) can be introduced into an amic acid derivative or an imidized product thereof.

1.1 Raw material having skeleton (1) The raw material having skeleton (1) is not particularly limited as long as it is an acid anhydride and / or amine having skeleton (1). The acid anhydride represented by (2-2) is preferable.

式（２−１）〜（２−２）中、Ｒ¹、Ｒ²、Ｒ³およびＲ⁴は、それぞれ独立に水素または炭素数１〜１０のアルキル、好ましくは水素または炭素数１〜８のアルキル、より好ましくは水素であり、Ｒ⁵は単結合、炭素または炭素数１〜５０の有機基、好ましくは単結合、炭素または炭素数１〜３０の有機基、より好ましくは単結合、炭素または炭素数１〜２０の有機基であり、ｍは１または２であり、ｎは１または２である。

In formulas (2-1) to (2-2), R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen or alkyl having 1 to 10 carbons, preferably hydrogen or having 1 to 8 carbons. Alkyl, more preferably hydrogen, and R ⁵ is a single bond, carbon or an organic group having 1 to 50 carbon atoms, preferably a single bond, carbon or an organic group having 1 to 30 carbon atoms, more preferably a single bond, carbon or It is a C1-C20 organic group, m is 1 or 2, and n is 1 or 2.

  Preferable examples of the acid anhydride represented by the formula (2-1) include tetracarboxylic dianhydrides represented by the formulas (3) to (5).

  Moreover, the dicarboxylic acid anhydride represented by Formula (6)-(7) is also mentioned as a preferable example of the acid anhydride represented by Formula (2-2).

1.2 As raw materials for synthesizing other raw material compounds (A), together with the raw materials having the skeleton (1) described above, tetracarboxylic dianhydrides and diamines that can be used as raw materials for ordinary polyimides, and ordinary raw materials A dicarboxylic acid anhydride or monoamine that can be used as a terminal blocking agent can be used in combination. Specific examples include tetracarboxylic dianhydride (a1), diamine (a2), dicarboxylic anhydride (a3) and monoamine (a4) shown below, but are not limited thereto. For example, the compounds described in Patent Documents 6 to 10 can be used.

1.2.1 Tetracarboxylic dianhydride (a1)
Specific examples of tetracarboxylic dianhydride (a1) include pyromellitic dianhydride (abbreviation: PMDA), 3,3 ′, 4,4′-bicyclohexyltetracarboxylic dianhydride (abbreviation: BPDA). -H), 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenone tetracarboxylic dianhydride, 2,3,3 ′, 4′- Benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride, 2,2 ′, 3,3′-diphenylsulfonetetracarboxylic dianhydride, 2,3, 3 ', 4'-diphenylsulfone tetracarboxylic dianhydride, 3,3', 4,4'-diphenyl ether tetracarboxylic dianhydride (abbreviation: ODPA), 2,2 ', 3,3'-diphenyl ether tetra Carboxylic dianhydride 2,3,3 ′, 4′-diphenyl ether tetracarboxylic dianhydride, 2,2- [bis (3,4-dicarboxyphenyl)] hexafluoropropanoic dianhydride, ethylene glycol bis (anhydrotri Melitte), cyclobutanetetracarboxylic dianhydride, methylcyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, ethanetetracarboxylic acid And dianhydrides and butanetetracarboxylic dianhydrides. Only 1 type may be used for tetracarboxylic dianhydride (a1) and it may use it in combination of 2 or more type.

1.2.2 Diamine (a2)
Specific examples of the diamine (a2) include 3,3′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, and 2,2′-diaminodiphenyl. Propane, 3,3′-dimethyl-4,4′-diaminodiphenylmethane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane (abbreviation: BAPP), 2,2-bis [4- (4 -Aminophenoxy) phenyl] hexafluoropropane, m-phenylenediamine, p-phenylenediamine, m-xylylenediamine, p-xylylenediamine, benzidine, 1,1-bis [4- (4-aminophenoxy) phenyl] Cyclohexane, 1,1-bis [4- (4-aminophenoxy) phenyl] -4-methyl Rhohexane, 1,1-bis [4- (4-aminobenzyl) phenyl] cyclohexane, 1,1-bis [4- (4-aminobenzyl) phenyl] -4-methylcyclohexane, 1,1-bis [4- (4-Aminobenzyl) phenyl] methane, 1,3-bis (4-aminophenoxy) benzene, diethylene glycol bis (3-aminopropyl) ether (abbreviation: BAPEE), and compounds represented by the following formula (13) are mentioned. It is done.

式中、Ｒ⁸は独立して炭素数１〜３のアルキルまたはフェニルであり、Ｒ⁹は独立してメチレンまたはフェニレンであり、該フェニレンの任意の水素はアルキルで置き換えられていてもよく、ｘは独立して１〜６の整数であり、ｙは１〜７０の整数である。
ジアミン（ａ２）は、１種のみを用いてもよく、また、２種以上を組み合わせて用いてもよい。

In the formula, R ⁸ is independently alkyl or phenyl having 1 to 3 carbon atoms, R ⁹ is independently methylene or phenylene, and any hydrogen of the phenylene may be replaced by alkyl, Is independently an integer of 1 to 6, and y is an integer of 1 to 70.
As the diamine (a2), only one kind may be used, or two or more kinds may be used in combination.

1.2.3 Dicarboxylic anhydride (a3)
Specific examples of the dicarboxylic acid anhydride (a3) include phthalic anhydride, trimellitic anhydride, 3-methylphthalic anhydride, 4-methylphthalic anhydride, 4-tert-butylphthalic anhydride, 3-fluorophthalic acid. Anhydride, 4-fluorophthalic anhydride, 4-ethynylphthalic anhydride, 4-phenylethynylphthalic anhydride, tetrafluorophthalic anhydride, succinic anhydride, butyl succinic anhydride, n-octyl succinic Acid anhydride, dodecyl succinic anhydride, tetrapropenyl succinic anhydride, tetradecenyl succinic anhydride, octadecenyl succinic anhydride, allyl succinic anhydride, 2-buten-1-yl succinic anhydride, 2-dodecene -1-ylsuccinic anhydride, maleic anhydride (abbreviation: MA), 2,3-dimethylmaleic anhydride, gluta Acid anhydride, itaconic acid anhydride, citraconic acid anhydride, allyl nadic acid anhydride, cis-1,2-cyclohexanedicarboxylic acid anhydride, 4-methylcyclohexane-1,2-dicarboxylic acid anhydride, cis-4- Cyclohexene-1,2-dicarboxylic anhydride, methylcyclohexene-1,2-dicarboxylic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, 1,3-cyclohexanedicarboxylic anhydride, p- (Trimethoxysilyl) phenyl succinic anhydride, p- (triethoxysilyl) phenyl succinic anhydride, m- (trimethoxysilyl) phenyl succinic anhydride, m- (triethoxysilyl) phenyl succinic anhydride, Trimethoxysilylpropyl succinic anhydride and It includes triethoxysilylpropyl succinate anhydrase hydride.

Among these, phthalic anhydride, trimellitic anhydride, 4-methylphthalic anhydride, 4-tert-butylphthalic anhydride, 4-fluorophthalic anhydride, tetrafluorophthalic anhydride, tetrapropenyl succinic anhydride , Tetradecenyl succinic anhydride, octadecenyl succinic anhydride, 2-dodecen-1-yl succinic anhydride, glutaric anhydride, itaconic anhydride, citraconic anhydride, allyl nadic acid anhydride, cis-1 , 2-cyclohexanedicarboxylic acid anhydride, 4-methylcyclohexane-1,2-dicarboxylic acid anhydride, cis-4-cyclohexene-1,2-dicarboxylic acid anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride And 1,3-cyclohexanedicarboxylic acid anhydride are preferred.
Only one type of dicarboxylic acid anhydride (a3) may be used, or two or more types may be used in combination.

1.2.4 Monoamine (a4)
Specific examples of the monoamine (a4) include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, and 4-aminobutyltrimethoxysilane. 4-aminobutyltriethoxysilane, 4-aminobutylmethyldiethoxysilane, p-aminophenyltrimethoxysilane, p-aminophenyltriethoxysilane, p-aminophenylmethyldimethoxysilane, p-aminophenylmethyldiethoxysilane , M-aminophenyltrimethoxysilane, m-aminophenylmethyldiethoxysilane, 4-ethynylaniline, 3-ethynylaniline, propargylamine, 3-aminobutyne, 4-aminobutyne, 5-aminopentyne 4 Aminopenchin, allylamine, 7 Aminohepuchin, m- aminostyrene, p- aminostyrene, m- amino -α- methyl styrene, and 3-aminophenyl acetylene and 4-aminophenyl acetylene.

Among these, for example, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltriethoxysilane, and p-aminophenyltrimethoxysilane from the viewpoint of excellent durability of the obtained film. Is preferred, and 3-aminopropyltriethoxysilane is particularly preferred.
Only one type of monoamine (a4) may be used, or two or more types may be used in combination.

1.3 Method for Synthesizing Compound (A) Examples of the method for synthesizing the compound (A) include methods described in Patent Documents 6 to 10.

1.3.1 Method for Synthesizing Amic Acid Derivative (A1) The amic acid derivative (A1) has an amine, diamine (a2) and / or monoamine (a4) having a skeleton (1), and a skeleton (1). Reaction of acid anhydride, tetracarboxylic dianhydride (a1) and / or dicarboxylic anhydride (a3) under mild reaction conditions in which an amino group and an acid anhydride group react to form an amic acid Can be obtained.

  The mild reaction conditions include, for example, a carboxyl produced by ring opening of an acid anhydride group by reaction without using a catalyst at a temperature of 20 to 60 ° C. and a reaction time of 0.2 to 20 hours under normal pressure. The condition is that the reaction is performed without activating the group. The activation of the carboxyl group is, for example, conversion to acid chloride.

  Under such mild reaction conditions, the carboxyl group produced by the reaction of the acid anhydride group with the amino group is further converted to an amino group of amine, diamine (a2) and / or monoamine (a4) having a skeleton (1). Since it does not react with the group, an amic acid derivative having a free carboxyl group is obtained.

1.3.2 Method for synthesizing imidized product (A2) The imidized product (A2) can be obtained by imidizing the amic acid derivative (A1). Specifically, the imidized product (A2) is obtained by imidizing an amic acid derivative by a thermal method or a chemical method using a dehydration catalyst and a dehydrating agent, and preferably a component of the ink without performing a purification treatment. A method of imidization by a thermal method that can be used as an acid anhydride, more preferably an acid anhydride having a skeleton (1), an amine having a skeleton (1), a tetracarboxylic dianhydride (a1), a diamine (a2), a dicarboxylic acid It can be obtained by a method in which raw materials such as acid anhydride (a3) and monoamine (a4) are reacted in a reaction solvent and then refluxed to imidize. Refluxing is preferably carried out at 140 to 230 ° C. for 1.5 to 10 hours, although the conditions vary depending on the reaction solvent used. When the reflux temperature is within the above range, imidization is sufficiently advanced and a strong film can be obtained, and reflux is possible even using a solvent having a relatively high boiling point.

1.3.3 Reaction Solvent The reaction solvent used for synthesizing the amic acid derivative (A1) or its imidized product (A2) is not particularly limited as long as it can synthesize the amic acid derivative or its imidized product.

  Specific examples of the reaction solvent include ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, Diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether (abbreviation: EDM), diethylene glycol isopropyl methyl ether, diethylene glycol butyl methyl ether, diethylene glycol monoethyl ether acetate, triethylene glycol monomethyl ether, trie Lenglycol dimethyl ether, triethylene glycol divinyl ether, propylene glycol monomethyl ether (1-methoxy-2-propanol), propylene glycol monoethyl ether (1-ethoxy-2-propanol), propylene glycol monobutyl ether (1-butoxy-2- Propanol), propylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol dimethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol dimethyl ether, tetramethylene glycol monovinyl ether, methyl 3-methoxypropionate, 3- Ethyl ethoxypropionate, lactate , Methyl benzoate, ethyl benzoate, anisole, cyclohexanone, γ-butyrolactone, 1,3-dioxolane, 1,4-dioxane, 2-pyrrolidone, 1-methyl-2-pyrrolidone (abbreviation: NMP), 1-vinyl 2-pyrrolidone, 1-butyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1- (2-hydroxyethyl) -2-pyrrolidone, 1-acetyl-2-pyrrolidone, N-methyl-ε-caprolactam, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylpropionamide and 1,3-dimethyl-2-imidazolidinone.

  Among these, propylene glycol monomethyl ether acetate, methyl 3-methoxypropionate, cyclohexanone, diethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether and γ-butyrolactone are preferable in terms of solubility.

  Only 1 type may be used for a reaction solvent, and 2 or more types may be mixed and used for it. In addition, other solvents other than the above reaction solvent can be mixed with the reaction solvent. The reaction solvent is preferably used in an amount of 100 parts by weight or more based on 100 parts by weight of the total amount of raw material compounds used in the reaction because the reaction proceeds smoothly.

1.4 Example of Compound (A) The compound (A) is not limited as long as it can prepare an inkjet ink having a skeleton (1) and having necessary properties such as viscosity, surface tension, and boiling point of the solvent. Is not to be done.

  As a preferred example of the compound (A), a polyamic acid obtained by using a diamine and a compound having two or more acid anhydride groups or an imidized product thereof (for example, see Patent Document 6), has an amic acid structure in the molecule. Examples thereof include silicon amide acid which is a silicon compound or an imidized product thereof (for example, see Patent Documents 7 and 8) and an alkenyl-substituted nadiimide compound having at least one alkenyl-substituted nadiimide structure in the molecule (for example, see Patent Documents 9 and 10). It is done.

  As a specific example of the amic acid derivative (A1), at least selected from the group consisting of a structural unit represented by formula (8) and a molecular end group represented by formula (8-1) and formula (8-2) A compound having one kind of molecular end group (hereinafter referred to as “compound (8)”) and a compound represented by formulas (9) to (12) (hereinafter referred to as “compound (9)” to “compound (12)”, respectively) However, it is not limited to these. Specific examples of the imidized product (A2) include imidized products of the compounds (8) to (12), but are not limited thereto.

In the formulas (8), (8-1), (8-2) and (9) to (12), X is carbon or a tetravalent organic group having 2 to 100 carbon atoms, preferably carbon or 2 to 80 A tetravalent organic group, more preferably carbon or a tetravalent organic group having 2 to 50 carbon atoms, and Y is a divalent organic group having 1 to 100 carbon atoms, preferably a divalent organic group having 1 to 80 carbon atoms. Preferably it is a 1-50 divalent organic group, Z is a C1-C100 monovalent organic group, Preferably it is a 1-80 monovalent organic group, More preferably, it is a 1-50 monovalent organic group. An organic group, wherein at least one of X, Y and Z has a skeleton (1), X ′ is independently a divalent organic group having 1 to 100 carbon atoms, preferably a carbon having an unsaturated hydrocarbon structure. A divalent organic group of 2 to 100 or a divalent organic group represented by formula (a), more preferably an unsaturated hydrocarbon structure; A divalent organic group having 2 to 80 carbon atoms or a divalent organic group represented by formula (a),
Y ′ is independently a monovalent organic group having 1 to 100 carbon atoms, preferably a monovalent organic group having 2 to 100 carbon atoms having an unsaturated hydrocarbon structure, or a monovalent group represented by the formula (b) An organic group, more preferably a monovalent organic group having 2 to 80 carbon atoms having an unsaturated hydrocarbon structure or a monovalent organic group represented by formula (b).

  In the formulas (a) and (b), R is independently hydrogen, alkyl having 1 to 20 carbons or alkoxy having 1 to 20 carbons, preferably hydrogen, alkyl having 1 to 10 carbons or 1 to 10 carbons. R ′ is a trivalent organic group having 1 to 20 carbon atoms, preferably alkyl having 1 to 10 carbon atoms, and R ″ is a divalent organic group having 1 to 20 carbon atoms, preferably carbon. It is the alkyl of number 1-10.

  Examples of the alkenyl-substituted nadiimide compound include an imidized product of the compound (9) or (11), wherein X ′ is a divalent organic group having an unsaturated hydrocarbon structure represented by the formula (c). .

In formula (c), R ¹² and R ¹³ are each independently hydrogen, alkyl having 1 to 12 carbons, alkenyl having 3 to 6 carbons, cycloalkyl having 5 to 8 carbons, or aryl having 6 to 12 carbons. Or benzyl.

1.5 Content of Compound (A) The inkjet ink of the present invention is 5 to 95 parts by weight, preferably 20 to 80 parts by weight, more preferably 30 to 70 parts by weight of compound (A) with respect to 100 parts by weight of ink. Included in parts by weight. When the compound (A) is contained in an amount in the above range, it is possible to form a relatively thick polyimide film (2 μm or more) by one jetting, and the viscosity of the ink is within a viscosity range in which ink jet printing is possible. Can be adjusted.

  A higher concentration of the compound (A) is preferable because the film thickness of the polyimide film obtained from the ink-jet ink of the present invention is increased, but on the other hand, the viscosity tends to increase. There is a possibility that a problem that the ink cannot be discharged occurs.

<2. Solvent (B)>
The solvent (B) is not particularly limited as long as it can dissolve the compound (A). In addition, even if the solvent alone does not dissolve the compound (A), such a mixed solvent can be used as the solvent (B) as long as the compound (A) can be dissolved by mixing with another solvent. Is possible.
The boiling point of the solvent (B) is preferably 150 to 300 ° C, more preferably 150 to 250 ° C.

  Specific examples of the solvent (B) include ethanol, ethylene glycol, propylene glycol, glycerin, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, ethylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl. Ether acetate, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol butyl methyl ether Diethylene glycol monoethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, triethylene glycol divinyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, di Propylene glycol monomethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol dimethyl ether, tetramethylene glycol monovinyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl lactate , Methyl benzoate, ethyl benzoate, anisole, cyclohexanone, γ-butyrolactone, 1,3-dioxolane, 1,4-dioxane, 2-pyrrolidone, 1-methyl-2-pyrrolidone (abbreviation: NMP), 1-ethyl- 2-pyrrolidone, 1-butyl-2-pyrrolidone, 1-vinyl-2-pyrrolidone, 1- (2-hydroxyethyl) -2-pyrrolidone, 1-acetyl-2-pyrrolidone, N-methyl-ε-caprolactam, N , N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylpropionamide and 1,3-dimethyl-2-imidazolidinone.

  Among these, in terms of improving the durability of the inkjet head, ethyl lactate, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, propylene glycol monomethyl ether acetate, methyl 3-methoxypropionate, It is preferable that 1,3-dimethyl-2-imidazolidinone or γ-butyrolactone is contained as the solvent (B).

Among the above exemplified solvents, 1-vinyl-2-pyrrolidone, 1-butyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1- (2-hydroxyethyl) are used from the viewpoint of durability of the inkjet head. 2-pyrrolidone, 2-pyrrolidone, 1-methyl-2-pyrrolidone (abbreviation: NMP), 1-acetyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylpropion Amide solvents such as amide and N-methyl-ε-caprolactam are preferably contained in an amount of 50 parts by weight or less, preferably 20 parts by weight or less, based on 100 parts by weight of the total amount of the solvent (B). It is preferable that the solvent (B) is a non-amide solvent.
As described above, a reaction solvent is used for the synthesis of the compound (A). Therefore, when the said reaction solvent remains when the synthesis | combination of a compound (A) is completed, the reaction solvent can also be used as a solvent (B).

  Only 1 type may be used for a solvent (B), and 2 or more types may be mixed and used for it. The ink-jet ink of the present invention contains 5 to 95 parts by weight, preferably 20 to 80 parts by weight, more preferably 30 to 70 parts by weight of the solvent (B) with respect to 100 parts by weight of the ink. . When the content of the solvent (B) is within the above range, the viscosity of the ink jet ink does not increase too much, the jetting characteristics are good, and the polyimide film that can be formed by one jetting becomes too thin. There is no.

<3. Additives>
The ink-jet ink of the present invention may contain additives other than the compound (A) and the solvent (B) depending on the intended properties. Examples of such additives include polymer compounds, alkenyl-substituted nadiimide compounds, silicon amide acid compounds, epoxy resins, acrylic resins, surfactants, antistatic agents, coupling agents, epoxy curing agents, pH adjusters, Examples include rust preventives, antiseptics, antifungal agents, antioxidants, anti-reduction agents, evaporation accelerators, chelating agents, water-soluble polymers, pigments and dyes.

3.1 Polymer Compound The polymer compound is not particularly limited, and examples thereof include polyamic acid, soluble polyimide, polyamide, polyamide imide, polyamic acid ester, polyester, acrylic acid polymer, acrylate polymer, polyvinyl alcohol, and polyoxyethylene. Can be mentioned. Among these, polyimide polymer compounds such as polyamic acid and soluble polyimide are preferable.

  A high molecular compound refers to the compound which has a structural unit. In particular, a polymer compound having a weight average molecular weight of 1,000 to 10,000 is excellent in solubility in the solvent (B), and is preferable as a component contained in an inkjet ink. From the viewpoint of solubility in the solvent (B), the weight average molecular weight of the polymer compound is more preferably 1,000 to 7,500, still more preferably 1,000 to 5,000, and particularly preferably. 1,000 to 2,000.

  When the weight average molecular weight is 1,000 or more, it is chemically and mechanically stable without being evaporated by heat treatment. Moreover, since the solubility with respect to the solvent (B) of a high molecular compound is especially high as a weight average molecular weight is 2,000 or less, the density | concentration of the high molecular compound in the inkjet ink of this invention can be made high. For this reason, the softness | flexibility and heat resistance of the coating film obtained by apply | coating the inkjet ink can be improved.

  The weight average molecular weight of the polymer compound can be measured by a gel permeation chromatography (GPC) method. Specifically, the polymer compound is diluted with tetrahydrofuran (THF) or the like so as to have a concentration of about 1% by weight, and Tosoh Corporation columns G4000HXL, G3000HXL, G2500HXL and G2000HXL are connected in series in this order. It can be obtained by measuring by gel permeation chromatography (GPC) method using THF as a developing agent and converting to polystyrene.

  The concentration of the polymer compound in the inkjet ink of the present invention is usually 0 to 20% by weight, preferably 0 to 10% by weight. In such a concentration range, good characteristics as an insulating film may be imparted.

3.2 Epoxy Resin The epoxy resin is not particularly limited as long as it is a compound having oxirane or oxetane, but a compound having two or more oxiranes is preferable.

  Examples of the epoxy resin include a bisphenol A type epoxy resin, a glycidyl ester type epoxy resin, an alicyclic epoxy resin, a polymer of a monomer having an oxirane, and a copolymer of a monomer having an oxirane and another monomer. .

  Specific examples of the monomer having oxirane include glycidyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, and methyl glycidyl (meth) acrylate.

  Specific examples of other monomers copolymerized with the oxirane-containing monomer include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, iso -Butyl (meth) acrylate, tert-butyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, styrene, methylstyrene, Examples include chloromethylstyrene, (3-ethyl-3-oxetanyl) methyl (meth) acrylate, N-cyclohexylmaleimide, and N-phenylmaleimide.

  Preferred examples of the polymer of the monomer having oxirane and the copolymer of the monomer having oxirane and another monomer include polyglycidyl methacrylate, methyl methacrylate-glycidyl methacrylate copolymer, benzyl methacrylate-glycidyl methacrylate copolymer, n-butyl methacrylate-glycidyl methacrylate copolymer, 2-hydroxyethyl methacrylate-glycidyl methacrylate copolymer, (3-ethyl-3-oxetanyl) methyl methacrylate-glycidyl methacrylate copolymer, or styrene-glycidyl methacrylate copolymer. Can be mentioned. It is preferable that the inkjet ink contains these epoxy resins because the heat resistance of the polyimide film formed from the inkjet ink is improved.

  Specific examples of the epoxy resin include trade names “Epicoat 807”, “Epicoat 815”, “Epicoat 825”, “Epicoat 827”, “Epicoat 828”, “Epicoat 190P”, “Epicoat 191P” (oil-coated shell epoxy ( Product name) “Epicoat 1004”, “Epicoat 1256” (Japan Epoxy Resin Co., Ltd.), product name “Araldite CY177”, product name “Araldite CY184” (manufactured by Ciba Geigy Japan), product name “Celoxide 2021P”, “Celoxide 3000”, “EHPE-3150” (manufactured by Daicel Chemical Industries, Ltd.), trade name “Techmore VG3101L” (manufactured by Mitsui Chemicals, Inc.), N, N, N ′, N′− Tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidyl Aminomethyl) cyclohexane, N, N, N ', -4,4'- N'- tetraglycidyl diaminodiphenylmethane and the like. Among these, the trade name “Araldite CY184”, the trade name “Celoxide 2021P”, the trade name “Techmore VG3101L”, and the trade name “Epicoat 828” are preferable because the flatness of the resulting polyimide film is particularly good.

  Specific examples of the epoxy resin further include compounds of formulas (I) to (VI). Of these, the compounds of formula (I), formula (V) and formula (VI) are preferred because the flatness of the resulting film is particularly good.

In Formula (V), R ^f , R ^g and R ^h are each independently hydrogen or an organic group having 1 to 30 carbon atoms.
In the formula (VI), R ^c is a tetravalent organic group having 2 to 100 carbon atoms, and R ^d is a divalent organic group having 1 to 30 carbon atoms, for example, a straight chain having 1 to 30 carbon atoms or It is a branched divalent organic group, and the divalent organic group may contain a ring structure or oxygen. Examples of the ring structure include phenyl, cyclohexyl, naphthyl, cyclohexenyl, and tricyclo [5.2. .1.0 ^2,6] decanyl, and the like, R ^e is, oxetane, a monovalent organic group having an oxirane or 1,2-epoxycyclohexane, consisting preferably of formula (VII) ~ (IX) A monovalent organic group selected from the group;

式（ＶＩＩ）中、Ｒⁱは水素または炭素数１〜３のアルキルである。

In formula (VII), R ⁱ is hydrogen or alkyl having 1 to 3 carbon atoms.

  Preferable examples of the compound represented by the formula (VI) include a compound represented by the formula (X).

  Only one type of epoxy resin may be used, or two or more types may be used in combination. Although the density | concentration of the epoxy resin in the ink for inkjet of this invention is not specifically limited, Preferably it is 0.1 to 20 weight%, More preferably, it is 1 to 10 weight%. When the concentration is within the above range, the heat resistance, chemical resistance and flatness of the polyimide film formed from the inkjet ink of the present invention are good.

3.3 Acrylic Resin The acrylic resin is not particularly limited as long as it has an acrylic group or a methacrylic group. For example, a monofunctional polymerizable monomer having hydroxyl, a monofunctional polymerizable monomer having no hydroxyl, a bifunctional ( Examples thereof include a meth) acrylate, a trifunctional or higher polyfunctional (meth) acrylate homopolymer, and a copolymer of these monomers.

  Specific examples of the monofunctional polymerizable monomer having hydroxyl include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 1,4-cyclohexanedimethanol mono ( And (meth) acrylate. Among these, 4-hydroxybutyl acrylate and 1,4-cyclohexanedimethanol monoacrylate are preferable because the film to be formed can be made flexible.

Specific examples of the monofunctional polymerizable monomer having no hydroxyl include glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, and butyl (meth). Acrylate, iso-butyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 3,4-epoxycyclohexyl (meth) acrylate, isobornyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) ) acrylate, (3-ethyl-3-oxetanyl) methyl (meth) acrylate, tricyclo [5.2.1.0 ^{2, 6]} decanyl (meth) acrylate, dicyclopentenyl oxyethyl (meth) acrylate Glycerol mono (meth) acrylate, 5-tetrahydrofurfuryloxycarbonylpentyl (meth) acrylate, (meth) acrylate of ethylene oxide adduct of lauryl alcohol, ω-carboxypolycaprolactone mono (meth) acrylate, 3-methyl-3 -(Meth) acryloxymethyl oxetane, 3-ethyl-3- (meth) acryloxymethyl oxetane, 3-methyl-3- (meth) acryloxyethyl oxetane, 3-ethyl-3- (meth) acryloxyethyl oxetane 2-phenyl-3- (meth) acryloxymethyloxetane, 2-trifluoromethyl-3- (meth) acryloxymethyloxetane, 4-trifluoromethyl-2- (meth) acryloxymethyloxetane, p-vinyl Phenyl-3-eth Oxeta-3-yl methyl ether, styrene, methyl styrene, chloromethyl styrene, vinyl toluene, N-acryloyl morpholine, N-cyclohexyl maleimide, N-phenyl maleimide, (meth) acrylamide, polystyrene macromonomer, polymethyl methacrylate macromonomer, (Meth) acrylic acid, crotonic acid, α-chloroacrylic acid, cinnamic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, succinic acid mono [2- (meth) acryloyloxyethyl], malein And acid mono [2- (meth) acryloyloxyethyl] and cyclohexene-3,4-dicarboxylic acid mono [2- (meth) acryloyloxyethyl].

  Specific examples of the bifunctional (meth) acrylate include bisphenol F ethylene oxide modified diacrylate, bisphenol A ethylene oxide modified diacrylate, isocyanuric acid ethylene oxide modified diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol. Diacrylate monostearate, dipentaerythritol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,4-cyclohexanedimethanol diacrylate, 2 N-butyl-2-ethyl-1,3-propanediol diacrylate and trimethylolpropane dia Relate can be mentioned.

  Specific examples of trifunctional or higher polyfunctional (meth) acrylates are trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, epichlorohydrin modified Trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, glycerol tri (meth) acrylate, epichlorohydrin-modified glycerol tri (meth) acrylate, diglycerin tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, Pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, alkyl-modified dipenta Rithritol penta (meth) acrylate, alkyl-modified dipentaerythritol tetra (meth) acrylate, alkyl-modified dipentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, Examples include ethylene oxide-modified tri (meth) acrylate phosphate, tris [(meth) acryloxyethyl] isocyanurate, caprolactone-modified tris [(meth) acryloxyethyl] isocyanurate, and urethane (meth) acrylate.

  Only one type of acrylic resin may be used, or two or more types may be used in combination. Although the density | concentration of the acrylic resin in the ink for inkjet of this invention is not specifically limited, Preferably it is 0.1 to 20 weight%, More preferably, it is 1 to 10 weight%. When the concentration is within the above range, the heat resistance, chemical resistance and flatness of the coating film formed from the ink jet ink of the present invention are good.

3.4 Surfactant The surfactant is used to improve the wettability, leveling property, or coating property of the ink-jet ink of the present invention to the base substrate.

As the surfactant, for example, trade names “Byk-300”, “Byk-306”, “Byk-335”, “Byk-310”, “Byk-” can be used because the application property of the ink of the present invention can be improved. Silicone surfactants such as “341”, “Byk-344”, “Byk-370” (manufactured by Big Chemie); trade names “Byk-354”, “ByK-358”, “Byk-361” Acrylic surfactants (made by Big Chemie Co., Ltd.) and the like; Fluorine surfactants such as trade names “DFX-18”, “Factent 250”, and “Factent 251” (made by Neos) Is mentioned.
These surfactants may be used alone or in combination of two or more. The concentration of the surfactant in the inkjet ink of the present invention is preferably 0.01 to 1% by weight.

3.5 Antistatic Agent The antistatic agent is used for preventing charging of the ink-jet ink of the present invention, and is not particularly limited, but a known antistatic agent can be used. Specific examples include metal oxides such as tin oxide, tin oxide / antimony oxide composite oxide, and tin oxide / indium oxide composite oxide, and quaternary ammonium salts.
Only one type of antistatic agent may be used, or two or more types may be used in combination. The concentration of the antistatic agent in the inkjet ink of the present invention is preferably 0.01 to 1% by weight.

3.6 Coupling Agent The coupling agent is not particularly limited, and a known coupling agent, preferably a silane coupling agent can be used. Examples of the silane coupling agent include trialkoxysilane compounds or dialkoxysilane compounds.

Examples of trialkoxysilane compounds or dialkoxysilane compounds include γ-vinylpropyltrimethoxysilane, γ-vinylpropyltriethoxysilane, γ-acryloylpropylmethyldimethoxysilane, γ-acryloylpropyltrimethoxysilane, and γ-acryloylpropylmethyldisilane. Ethoxysilane, γ-acryloylpropyltriethoxysilane, γ-methacryloylpropylmethyldimethoxysilane, γ-methacryloylpropyltrimethoxysilane, γ-methacryloylpropylmethyldiethoxysilane, γ-methacryloylpropyltriethoxysilane, γ-glycidoxypropyl Methyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxyp Propyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-aminoethyl-γ-iminopropylmethyldimethoxysilane N-aminoethyl-γ-aminopropyltrimethoxysilane, N-aminoethyl-γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane N-phenyl-γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-merca Examples thereof include ptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-isocyanatopropylmethyldiethoxysilane, and γ-isocyanatopropyltriethoxysilane. Among these, γ-vinylpropyltrimethoxysilane, γ-acryloylpropyltrimethoxysilane, γ-methacryloylpropyltrimethoxysilane and γ-isocyanatopropyltriethoxysilane are particularly preferable.
Only one type of coupling agent may be used, or two or more types may be used in combination. The concentration of the coupling agent in the inkjet ink of the present invention is preferably 0.01 to 3% by weight.

3.7 Epoxy Curing Agent The epoxy curing agent is not particularly limited, and is a known epoxy curing agent, specifically, an organic acid dihydrazide compound, imidazole and its derivatives, dicyandiamide, aromatic amine, polyvalent carboxylic acid. An acid, a polyvalent carboxylic acid anhydride, etc. can be used.

  More specifically, dicyandiamides such as dicyandiamide, adipic acid dihydrazide, organic acid dihydrazides such as 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin, 2,4-diamino-6- [2′- Ethylimidazolyl- (1 ′)]-ethyltriazine, 2-phenylimidazole, 2-phenyl-4-methylimidazole, imidazole derivatives such as 2-phenyl-4-methyl-5-hydroxymethylimidazole, phthalic anhydride, Examples include merit acid, acid anhydrides such as 1,2,4-cyclohexanetricarboxylic acid-1,2-anhydride, and trimellitic acid. Among these, trimellitic acid and 1,2,4-cyclohexanetricarboxylic acid-1,2-anhydride having good transparency are preferable.

  Only one epoxy curing agent may be used, or two or more epoxy curing agents may be used in combination. The concentration of the epoxy curing agent in the inkjet ink of the present invention is preferably 0.2 to 5% by weight.

<4. Inkjet ink properties>
4.1 Viscosity of inkjet ink The viscosity of the inkjet ink of the present invention at the temperature (ejection temperature) when ejecting from the inkjet head is preferably 1 to 50 mPa · s, more preferably 5 to 20 mPa · s, and further Preferably, it is 8-15 mPa · s. When the viscosity is within the above range, the jetting accuracy by the ink jet coating method is improved. When the viscosity is lower than 15 mPa · s, it is difficult to cause ink jet ejection defects.

  In addition, since jetting is often performed at room temperature (25 ° C.), the viscosity of the inkjet ink of the present invention at 25 ° C. is preferably 1 to 50 mPa · s, more preferably 5 to 20 mPa · s, and particularly preferably 8 ~ 15 mPa · s. When the viscosity at 25 ° C. is less than 15 mPa · s, it is difficult for ink jet ejection defects to occur.

4.2 Surface Tension of Inkjet Ink The surface tension of the inkjet ink of the present invention is preferably 20 to 70 mN / m, more preferably 20 to 40 mN / m. When the surface tension is within the above range, good droplets can be formed by jetting, and a meniscus can be formed.

4.3 Water content of ink-jet ink The water content in the ink-jet ink of the present invention is preferably 10,000 ppm or less, more preferably 5,000 ppm or less. When the water content is within the above range, the viscosity change of the inkjet ink is small and the storage stability is excellent.

[Polyimide film]
The polyimide film of the present invention is formed using the inkjet ink of the present invention. Specifically, the ink-jet ink of the present invention is coated on a substrate by an ink-jet coating method to form a coating film, and the coating film is heat-treated to form a whole surface or a predetermined pattern (for example, a line). A polyimide film can be formed. In addition, when the compound (A) contained in the inkjet ink of the present invention is an imidized product (A2), the treatment is not limited to the heat treatment, and may be a treatment of irradiating ultraviolet rays, ion beams, electron beams, gamma rays, or the like.

  Examples of the ejection method in the inkjet coating method include a piezoelectric element type, a bubble jet (registered trademark) type, a continuous jet type, and an electrostatic induction type. The ink-jet ink of the present invention can be ejected by various methods by appropriately selecting each component contained. According to the ink-jet coating method, the ink-jet ink of the present invention has a predetermined pattern shape. Can be applied.

  A preferred ejection method in the present invention is a piezoelectric element type. The piezoelectric element type head includes a nozzle forming substrate having a plurality of nozzles, a pressure generating element made of a piezoelectric material and a conductive material, and disposed opposite to the nozzles, and ink filling the periphery of the pressure generating element. The on-demand inkjet coating head includes a pressure generating element that is displaced by an applied voltage, and ejects a small droplet of ink from a nozzle.

  The ink jet coating apparatus is not limited to the configuration in which the coating head and the ink storage unit are separated from each other, and may be configured such that they are integrated so as not to be separated. The ink container is integrated with the coating head in a separable or non-separable manner and mounted on the carriage, and is provided at a fixed portion of the apparatus via an ink supply member such as a tube. It may be in the form of supplying ink to the coating head.

  Further, when the ink tank is provided with a configuration for applying a preferable negative pressure to the coating head, a configuration in which an absorber is disposed in the ink storage portion of the ink tank, or a flexible ink storage bag and this On the other hand, it is possible to adopt a form having a spring portion that applies a force in the direction of expanding the internal volume. In addition to the serial coating method, the coating apparatus may take the form of a line printer in which coating elements are aligned over a range corresponding to the entire width of the coating medium.

  After the inkjet ink of the present invention is applied onto a substrate by an inkjet application method, the solvent is removed by evaporation, for example, by heating in a hot plate or oven, that is, drying. Although this heating condition changes with kinds and compounding ratios of each component, it is normally 70-150 degreeC, when using oven, it will be 5 to 15 minutes, and when using a hotplate, it will dry for 1 to 5 minutes.

  After drying, in order to obtain the heat resistance, chemical resistance, flatness, and sufficient mechanical strength of the coating film, it is 150 to 350 ° C., preferably 200 to 300 ° C., and 30 to 30 when an oven is used. When a hot plate is used for 90 minutes, a polyimide film is formed by heat treatment (curing treatment) for 5 to 30 minutes. When printing in a pattern using an inkjet coating method, a patterned polyimide film is formed. In this specification, unless otherwise specified, the polyimide film includes a patterned polyimide film.

  The polyimide film thus obtained has a higher concentration of the compound (A) in the ink-jet ink of the present invention, so that the polyimide film formed by application and heating of the conventional ink-jet ink is used. The thickness is usually 2 μm or more, preferably 2 to 5 μm.

As described above, a thick polyimide film can be obtained from the inkjet ink of the present invention by one jetting. Therefore, when forming a thick insulating film of about 10 μm, for example, the number of times of overcoating can be reduced and the manufacturing process of the insulating film can be shortened as compared with the conventional ink jet ink.
Moreover, the polyimide film obtained from the inkjet ink of the present invention is excellent in heat resistance and electrical insulation, and can improve the reliability and yield of electronic components.

  The polyimide film of the present invention is preferably not easily peeled from the substrate, and the adhesion can be expressed by the adhesion strength of the polyimide film to the substrate. The adhesion strength is preferably 0.2 N / mm or more, more preferably 0.5 N / mm or more, and particularly preferably 0.5 to 1.5 N / mm. The adhesion strength of 0.2 N / mm or more is preferable because the polyimide film does not easily peel from the substrate.

[substrate]
The film substrate of the present invention is, for example, applied to the entire surface or a predetermined pattern (line shape, etc.) of the inkjet ink of the present invention on a substrate such as a polyimide film on which wiring is formed, and then, As described above, it is obtained by drying and further heating to form a polyimide film.

  The silicon wafer substrate of the present invention is applied, for example, to the substrate such as a silicon wafer by applying the inkjet ink of the present invention to the entire surface or a predetermined pattern by the inkjet coating method, and then drying and heating as described above. To obtain a polyimide film.

  The polyimide film that can be used in the present invention is preferably formed on a substrate such as the above-described polyimide film or on a silicon wafer substrate, but is not particularly limited thereto, and is formed on a known substrate. Can do.

  As a substrate applicable to the present invention, for example, a glass epoxy substrate, a glass composite substrate, a paper phenol substrate, paper that conforms to various standards such as FR-1, FR-3, FR-4, CEM-3, or E668. An epoxy board | substrate, a green epoxy board | substrate, and a BT resin board | substrate are mentioned.

  In addition, as other substrates applicable to the present invention, for example, a substrate made of a metal such as copper, brass, phosphor bronze, beryllium copper, aluminum, gold, silver, nickel, tin, chromium or stainless steel (these metals are It may be a substrate having a surface); aluminum oxide (alumina), aluminum nitride, zirconium oxide (zirconia), zirconium silicate (zircon), magnesium oxide (magnesia), aluminum titanate, barium titanate, titanium Lead oxide (PT), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), lithium niobate, lithium tantalate, cadmium sulfide, molybdenum sulfide, beryllium oxide (beryllia), silicon oxide (silica) , Silicon carbide (silicon carbide), silicon nitride (silicon Nitride), boron nitride (boron nitride), zinc oxide, mullite, ferrite, steatite, holsterite, spinel or spodumene, etc., a substrate (may be a substrate having such ceramics on the surface) PET (polyethylene terephthalate) resin, PBT (polybutylene terephthalate) resin, PCT (polycyclohexylene dimethylene terephthalate) resin, PPS (polyphenylene sulfide) resin, polycarbonate resin, polyacetal resin, polyphenylene ether resin, polyamide resin, polyarylate resin , Polysulfone resin, Polyethersulfone resin, Polyetherimide resin, Polyamideimide resin, Epoxy resin, Acrylic resin, Teflon (registered trademark), Thermoplastic A substrate made of a resin such as elastomer or liquid crystal polymer (may be a substrate having such a resin on its surface); a semiconductor substrate such as silicon, germanium or gallium arsenide; a glass substrate; tin oxide, zinc oxide, ITO or ATO, etc. A substrate on which the electrode material is formed; a gel sheet such as αGEL (alpha gel), βGEL (beta gel), θGEL (theta gel), or γGEL (gamma gel) (which is a registered trademark of Taika Co., Ltd.).

[Electronic parts]
The electronic component of the present invention is an electronic component having the above film substrate or an electronic component having the above silicon wafer substrate. Thus, a flexible electronic component is obtained using the film substrate of the present invention. In addition, a semiconductor electronic component can be obtained using the silicon wafer substrate of the present invention.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited to these Examples at all. In addition, the symbol of the name of the reaction raw material and solvent used by the Example and the comparative example is shown below.

<Tetracarboxylic dianhydride>
PMDA: pyromellitic dianhydride BPDA-H: 3,3 ′, 4,4′-bicyclohexyltetracarboxylic dianhydride TAPQ: tetracarboxylic dianhydride represented by formula (3)

<Diamine>
BAPP: 2,2-bis [4- (4-aminophenoxy) phenyl] propane BAPEE: Diethylene glycol bis (3-aminopropyl) ether <Dicarboxylic anhydride>
MA: Maleic anhydride <Solvent>
EDM: Diethylene glycol methyl ethyl ether (boiling point: 180-190 ° C.)
NMP: 1-methyl-2-pyrrolidone (boiling point: 202 ° C.)

[Synthesis Example 1]
A stirrer was placed in a 100 mL sample bottle, and the raw materials and the solvent were charged at the blending ratios shown in Table 1. After stirring at room temperature, a 25% by weight solution of light yellow polyamic acid (ink A) was obtained. The viscosity of this solution was measured at 25 ° C. with TV-22 (manufactured by TOKI SANGYO) and found to be 13.7 mPas.

[Synthesis Example 2]
In the same manner as in Synthesis Example 1, the raw materials and the solvent were added at the blending ratios shown in Table 1, and after stirring at room temperature, a 25% by weight solution of light yellow polyamic acid (ink B) was obtained. When the viscosity of this solution was measured in the same manner as in Synthesis Example 1, it was 11.5 mPas.

[Synthesis Example 3]
In the same manner as in Synthesis Example 1, the raw materials and the solvent were added at the blending ratios shown in Table 1, and after stirring at room temperature, a 25% by weight solution (ink C) of pale yellow polyamic acid was obtained. When the viscosity of this solution was measured in the same manner as in Synthesis Example 1, it was 16 mPas.

[Synthesis Example 4]
In the same manner as in Synthesis Example 1, the raw materials and the solvent were charged at the blending ratios shown in Table 1, and after stirring at room temperature, a 25% by weight solution (ink D) of pale yellow polyamic acid was obtained. When the viscosity of this solution was measured in the same manner as in Synthesis Example 1, it was 15 mPas.

[Example 1]
(1) Using an ink jet device ("DMP2831" manufactured by Dimatix), ink A was applied on the entire surface of a copper foil ("BHY-22B-T" manufactured by Nikko Metal, 20mm x 30mm) and dried at 80 ° C for 5 minutes. Subsequently, by heating at 180 ° C. for 60 minutes, a polyimide film having a thickness of 10 μm was formed, and a composite film of the polyimide film 4 and the copper foil 5 was obtained.

  (2) Next, as shown in FIG. 1, a glass epoxy supporting substrate 1 having a pressure-sensitive adhesive layer 2 (“SHG-1B” manufactured by McEight Co., Ltd .: 0.5 mm thickness) is coated on the entire surface with a masking tape 3 for gold plating ( “851A” manufactured by Sumitomo 3M; a polyester film having an adhesive of 3.49 N / 10 mm and a tensile strength of 35 N / 10 mm with an adhesive applied to one side of the polyester film.

  A composite film of the polyimide film 4 and the copper foil 5 prepared in the above (1) was attached to the masking tape 3. At this time, the surface of the masking tape 3 to which the adhesive was applied was in contact with the polyimide film 4. Further, a masking tape for gold plating having a width of 2.5 mm (“851A” manufactured by Sumitomo 3M) is attached to the copper foil 5 on the composite film, and a glass epoxy supporting substrate 1 having an adhesive layer 2 1 -masking tape 3 -polyimide film The laminated body laminated | stacked in order of 4-copper foil 5-masking tape for gold plating was obtained.

The obtained laminate was etched by the following method. Etching was performed by immersing the laminate in a ferric chloride solution (“H-1000A” manufactured by Sanhatoya) (with air bubbling) and a bath temperature of 45 ° C. for 15 minutes.
The laminated body after the etching treatment was washed with pure water, and then the masking tape attached to the copper foil was peeled off to obtain an evaluation sample having a copper foil with a width of 2.5 mm.

  (3) Using the tensile tester (“Shimadzu tabletop small-sized tester EZGraph” manufactured by Shimadzu Corporation), the copper foil 5 of the obtained evaluation sample was 180 under the conditions of a tensile speed of 50 mm / min and a load cell of 20N. Peeled in the direction of °, and the strength was defined as the adhesion strength. As a result, the adhesion strength was 0.7 N / mm.

[Comparative Example 1]
An evaluation sample was prepared in the same manner as in Example 1 except that ink B was used instead of ink A, and the adhesion strength was measured. The adhesion strength was 0.1 N / mm.

[Comparative Example 2]
An evaluation sample was prepared in the same manner as in Example 1 except that ink C was used instead of ink A, and the adhesion strength was measured. The adhesion strength was 0.04 N / mm.

[Comparative Example 3]
An evaluation sample was prepared in the same manner as in Example 1 except that ink D was used instead of ink A, and the adhesion strength was measured. The adhesion strength was 0.19 N / mm.

  Ink A used in Example 1 had an ink viscosity of 13.7 mPas suitable for inkjet printing. Further, the ink A can be ejected from the nozzle of the ink jet apparatus, and does not spread immediately after being ejected, and can form good liquid droplets. Therefore, the surface tension is suitable for the ink for ink jet. all right. Furthermore, from the results of Example 1, it was also found that a solvent having a boiling point in the range of 100 to 300 ° C. can be used. From these facts, it can be evaluated that the ink A of Example 1 is an ink in which the parameters of the viscosity, the surface tension, and the boiling point of the solvent are optimized for inkjet printing.

  Moreover, when the adhesive strength with the board | substrate was measured about the coating film formed using the ink A, the high value of 0.7 N / mm was shown. From this, it was found that by using the ink A, a polyimide film showing good adhesion to the substrate could be formed.

  On the other hand, although the inks B to D used in Comparative Examples 1 to 3 could be used for inkjet printing, the coating strength formed with the inks B to D was used for adhesion strength with the substrate. Were measured, all showed a low value of 0.2 N / mm or less. From this, it was found that the polyimide film formed using the inks B to D had insufficient adhesion to the substrate and was easily peeled off.

DESCRIPTION OF SYMBOLS 1 Support substrate 2 Adhesive layer 3 Masking tape with adhesive 4 Polyimide film 5 Copper foil

Claims (16)

An inkjet ink comprising at least one compound (A) selected from the group consisting of an amic acid derivative (A1) having a skeleton represented by formula (1) and an imidized product (A2) thereof.

(Wherein R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen or alkyl having 1 to 10 carbon atoms.) The inkjet ink according to claim 1, wherein the compound (A) is a compound obtained by using an acid anhydride represented by the formula (2-1) or (2-2).

Wherein R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen or alkyl having 1 to 10 carbons, and R ⁵ is a single bond, carbon or an organic group having 1 to 50 carbons. , M is 1 or 2, and n is 1 or 2.) The inkjet ink according to claim 1 or 2, wherein the compound (A) is a compound obtained by using at least one selected from tetracarboxylic dianhydrides represented by formulas (3) to (5). .

The inkjet ink according to claim 1 or 2, wherein the compound (A) is a compound obtained by using at least one selected from dicarboxylic anhydrides represented by formulas (6) to (7).

The amic acid derivative (A1) is at least one molecule selected from the group consisting of a structural unit represented by formula (8) and molecular end groups represented by formulas (8-1) and (8-2) The inkjet ink according to any one of claims 1 to 4, wherein the inkjet ink is at least one selected from the group consisting of compounds having a terminal group and compounds represented by formulas (9) to (12).

(In the formula, X is carbon or a tetravalent organic group having 2 to 100 carbon atoms, Y is a divalent organic group having 1 to 100 carbon atoms, and Z is a monovalent organic group having 1 to 100 carbon atoms. And when at least one of X, Y and Z has a skeleton represented by formula (1), and X has a skeleton represented by formula (1), X is 4 having 14 to 100 carbon atoms. When Y has a skeleton represented by the formula (1), Y is a divalent organic group having 13 to 100 carbon atoms, and Z represents a skeleton represented by the formula (1). Z is a monovalent organic group having 13 to 100 carbon atoms , X ′ is independently a divalent organic group having 1 to 100 carbon atoms, and Y ′ is independently 1 to 100 carbon atoms. Of the monovalent organic group.) In the formulas (8-1), (8-2) and (9) to (12), X ′ is independently a divalent organic group having 2 to 100 carbon atoms having an unsaturated hydrocarbon structure or the formula (a ), A monovalent organic group having 2 to 100 carbon atoms and Y ′ independently having an unsaturated hydrocarbon structure or a monovalent organic group represented by formula (b) The inkjet ink according to claim 5, which is a base.

Wherein R is independently hydrogen, alkyl having 1 to 20 carbons or alkoxy having 1 to 20 carbons, R ′ is a trivalent organic group having 1 to 20 carbons, and R ″ is carbon. (It is a divalent organic group of the number 1-20.)   Furthermore, the ink for inkjets of any one of Claims 1-6 containing a solvent (B).   Solvent (B) is ethanol, ethylene glycol, propylene glycol, glycerin, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, ethylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol Monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol butyl methyl ether, diethylene glycol Cole monoethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, triethylene glycol divinyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, di Propylene glycol monomethyl ether, dipropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol dimethyl ether, tetramethylene glycol monovinyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl lactate, benzoic acid , Ethyl benzoate, anisole, cyclohexanone, γ-butyrolactone, 1,3-dioxolane, 1,4-dioxane, 2-pyrrolidone, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1-butyl- 2-pyrrolidone, 1-vinyl-2-pyrrolidone, 1- (2-hydroxyethyl) -2-pyrrolidone, 1-acetyl-2-pyrrolidone, N-methyl-ε-caprolactam, N, N-dimethylacetamide, N, The inkjet ink according to claim 7, wherein the inkjet ink is at least one selected from the group consisting of N-diethylacetamide, N, N-dimethylpropionamide, and 1,3-dimethyl-2-imidazolidinone.   The inkjet ink according to any one of claims 1 to 8, comprising the compound (A) in an amount of 5 to 95 parts by weight with respect to 100 parts by weight of the inkjet ink.   A polyimide film formed using the inkjet ink according to claim 1.   The polyimide film according to claim 10, which has a pattern shape.   The process of apply | coating the inkjet ink of any one of Claims 1-9 on a board | substrate with an inkjet coating method, and forming a coating film, The process of heat-processing this coating film and forming a polyimide film A polyimide film forming method comprising:   The film board | substrate formed by forming the polyimide film of Claim 10 or 11 on a board | substrate.   An electronic component having the film substrate according to claim 13.   A silicon wafer substrate in which the polyimide film according to claim 10 or 11 is formed on a substrate.   An electronic component comprising the silicon wafer substrate according to claim 15.

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