JP2009102494A - Composition for use in screen printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide such a composition for use in screen printing as gives a polyimide membrane having a good screen printability and also having excellent mechanical strengths and a flexibility. <P>SOLUTION: The composition for use in screen printing comprises (A) a polyamic acid having a weight-average molecular weight of 80,000-500,000, (B) an epoxy resin with a specific structure, (C) a metal oxide microparticle having an average particle diameter of 0.001 μm-10 μm, and (D) a solvent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a composition for screen printing, for example, a polyamic acid composition for forming an insulating film layer in the manufacture of electronic components, a polyimide film formed using the composition, and a film substrate on which the polyimide film is formed. And an electronic component having the film substrate.

  Polyimide is a material 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). When polyimide is used as a desired pattern film, it has been common to form a pattern using etching or photosensitive polyimide. However, a large amount of photoresist, developer, etchant, stripper, etc. A chemical solution is required, and further complicated steps are required. Therefore, in recent years, methods for forming a desired pattern film by screen printing have been studied.

Various screen printing compositions have been proposed (see, for example, Patent Documents 4 and 5). In general, resin fine particles or inorganic fine particles are added to the composition in order to adjust the viscosity (providing thixotropy). To use. However, if the particle size of the resin fine particles or inorganic fine particles to be added is large, or if the dispersibility in the composition is not good, there is a problem that mesh residue and blurring occur and the film flatness deteriorates. .
In addition, the mechanical strength of the polyimide film obtained by adding the fine particles may be extremely deteriorated, and cracks may occur due to residual strain caused by polyimide shrinkage when the polyimide film is formed. In particular, when a flexible substrate is used, since a bending characteristic often becomes a problem, a polyimide film having a good bending characteristic is desired. This bending property means whether or not the flexible substrate and the circuit on the substrate are not bent or cut when the flexible substrate is vertically set up, held at both ends, and alternately moved up and down. It is a characteristic and is also called a sliding characteristic.

JP 2000-039714 A JP 2003-238683 A JP 2004-094118 A JP-A-4-153261 JP 2007-16158 A

  Under the circumstances described above, there is a need for a screen printing composition that has good screen printability and can obtain a polyimide film having a uniform thickness without causing mesh residue or bleeding. There is also a need for a composition for screen printing that is strong in mechanical strength and has good flexibility without cracks.

The present inventors have disclosed a screen comprising a polyamic acid (A) having a specific weight average molecular weight, an epoxy resin (B) having a specific structure, fine metal oxide particles (C) having a specific average particle size, and a solvent (D). The present invention was completed by finding that the printing composition has the above-described excellent characteristics.
The present invention provides the following screen printing composition and the like.

（式（１）中、Ｒ¹とＲ²はそれぞれ独立して炭素数２〜１００の有機基である。） [1] Polyamic acid (A) having a structural unit represented by the following general formula (1) (A) having a weight average molecular weight of 80,000 to 500,000, epoxy resin (B), metal oxide fine particles having an average particle size of 0.001 μm to 10 μm ( C) and a solvent (D), and the epoxy resin (B) contains N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane and selected from the group consisting of compounds represented by the following formulas (2) to (4) A composition for screen printing, comprising one or more compounds.

(In formula (1), R ¹ and R ² are each independently an organic group having 2 to 100 carbon atoms.)

[2] The composition for screen printing according to the above [1], wherein the polyamic acid (A) has a weight average molecular weight of 100,000 to 200,000.

[3] The epoxy resin (B) is N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N The composition for screen printing according to the above [1] or [2], comprising one or more compounds selected from ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane.

[4] Based on the total amount of the composition for screen printing, the polyamic acid (A) is 5 to 60% by weight, the epoxy resin (B) is 5 to 60% by weight, and the metal oxide fine particles (C) are 0.1 to 10%. The composition for screen printing according to any one of the above [1] to [3], comprising 20% by weight and 20 to 89.9% by weight of the solvent (D).

[5] As tetracarboxylic dianhydride (a1), pyromellitic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2,3,4-butanetetracarboxylic dianhydride At least one selected from the group consisting of anhydrides and at least selected from the group consisting of 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane and 4,4′-diaminodiphenylethane as the diamine (a2) A polyamic acid (A) having a weight average molecular weight of 80,000 to 500,000, obtained using
As the epoxy resin (B), N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane,
A composition for screen printing comprising, as metal oxide fine particles (C), silica fine particles having an average particle size of 0.001 μm to 10 μm, and N-methyl-2-pyrrolidone as a solvent (D).

[6] A polyimide film or a patterned polyimide film obtained from the composition for screen printing described in any one of [1] to [5].

[7] A step of applying the composition for screen printing described in any one of [1] to [5] above by screen printing to form a polyamic acid film, and treating the formed polyamic acid film A polyimide film or a patterned polyimide film obtained through a step of forming a polyimide film.

[8] A film substrate in which the polyimide film or patterned polyimide film described in [7] is formed on a substrate.

[9] An electronic component having the film substrate described in [8].

  The composition for screen printing according to a preferred embodiment of the present invention has, for example, good screen printability, and a polyimide film having a uniform thickness can be obtained without causing mesh residue or bleeding. Moreover, when the composition for screen printing which concerns on the preferable aspect of this invention is used, mechanical strength is strong and it can form a flexible polyimide film without generating a crack.

  Furthermore, when the composition for screen printing according to a preferred embodiment of the present invention is used for the formation of a patterned polyimide film, it is not necessary to use a photomask, so that it is possible to produce a variety of products and mass production, The number of steps required for manufacturing can be reduced. Moreover, the polyimide film formed from the composition for screen printing of this invention has high heat resistance and electrical insulation, for example, and can improve the reliability and yield of an electronic component.

1. Screen printing composition of the present invention The screen printing composition of the present invention comprises a polyamic acid (A), an epoxy resin (B), metal oxide fine particles (C) and a solvent (D). It is.
The screen printing composition is obtained, for example, by dissolving the polyamic acid (A) and the epoxy resin (B) in the solvent (D) and then mixing the metal oxide fine particles (C) and other additives by a conventional method. be able to. Specifically, for example, roll kneading, mixer mixing, and the like performed in the paint field are applied, and as a mixing device, a reiki machine, a three-roll, a ball mill, a planetary mixer, or the like can be used. Two or more of these mixing apparatuses may be used in combination as appropriate.

1.1 Viscosity of Screen Printing Composition The viscosity of the screen printing composition is not particularly limited, but the viscosity on a rotary viscometer is 500 to 500,000 mPa · s at 25 ° C., and the thixotropic coefficient is 2.0 to 10. 0 is preferred. More preferably, the viscosity is 1,000 to 400,000 mPa · s at 25 ° C. and the thixotropic coefficient is 3.0 to 7.0, and still more preferably, the viscosity is 5,000 to 300,000 mPa · s at 25 ° C. and the thixotropic coefficient is 3. 0-5.0.
When the viscosity is 500 mPa · s or more, a uniform coating film can be obtained without the paste flowing out after printing. On the other hand, if the viscosity is 500,000 mPa · s or less, the transfer property of the paste to the substrate is good, and the occurrence of voids and pinholes in the printed film can be suppressed. Further, when the thixotropy coefficient is 2.0 or more, there is no occurrence of paste stringing and no paste flows out after printing. On the other hand, if the thixotropy coefficient is 10.0 or less, the coating film after printing will not be blurred or uneven.
Here, the viscosity of the composition for screen printing was measured at 25 ° C. using an E-type viscometer (VISCONIC ELD manufactured by TOKYO KEIKI). The thixotropy coefficient is calculated from the apparent viscosity at 25 ° C. at a rotation speed of 1 to 10 rpm using a rheometer (R / S plus rheometer manufactured by Brookfield).

1.2 Polyamic acid (A)
The polyamic acid (A) is a polyamic acid having a structural unit represented by the general formula (1). Hereinafter, the structural unit represented by Formula (1) will be described.

1.2.1 Structural Unit Represented by General Formula (1) In the above formula (1), R ¹ is a tetravalent organic group having 2 to 100 carbon atoms independently for each structural unit. ² is a divalent organic group having 2 to 100 carbon atoms independently for each structural unit. The “organic group having 2 to 100 carbon atoms” is preferably an organic group having 3 to 70 carbon atoms, and more preferably an organic group having 4 to 50 carbon atoms.

Specific examples of the “organic group” include hydrocarbons having 2 to 20 carbon atoms which may have a substituent, alkoxy having 2 to 20 carbon atoms which may have a substituent, and substituents. Aryloxy having 6 to 20 carbon atoms which may have, amino which may have a substituent, silyl which may have a substituent, alkylthio which may have a substituent (- SY ¹ , wherein Y ¹ represents an optionally substituted alkyl having 2 to 20 carbon atoms), and optionally substituted arylthio (—SY ² , wherein Y ² Represents an optionally substituted aryl having 6 to 18 carbon atoms), an optionally substituted alkylsulfonyl (—SO ₂ Y ³ , wherein Y ³ has a substituent. An alkylsulfonyl having 2 to 20 carbon atoms which may be substituted.), An arylsulfonyl which may have a substituent (-SO ₂ Y ^4,: in the formula, Y ⁴ is. To an aryl having 6 to 18 carbon atoms which may have a substituent group).

  The hydrocarbon of “C2-C20 hydrocarbon” may be saturated or unsaturated acyclic, or may be saturated or unsaturated cyclic. When the hydrocarbon having 2 to 20 carbon atoms is acyclic, it may be linear or branched. “C2-C20 hydrocarbon” includes C2-C20 alkyl, C2-C20 alkenyl, C2-C20 alkynyl, C4-C20 alkyldienyl, C6-C6. -18 aryl, C7-20 alkylaryl, C7-20 arylalkyl, C4-20 cycloalkyl, C4-20 cycloalkenyl and the like are included.

  “C2-C20 alkyl” is preferably C2-C10 alkyl, and more preferably C2-C6 alkyl. Examples of alkyl include ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, i-butyl, pentyl, hexyl, dodecyl and the like.

  The “alkenyl having 2 to 20 carbon atoms” is preferably alkenyl having 2 to 10 carbon atoms, and more preferably alkenyl having 2 to 6 carbon atoms. Examples of alkenyl include vinyl, allyl, propenyl, isopropenyl, 2-methyl-1-propenyl, 2-methylallyl, 2-butenyl and the like.

  “Alkynyl having 2 to 20 carbon atoms” is preferably alkynyl having 2 to 10 carbon atoms, more preferably alkynyl having 2 to 6 carbon atoms. Examples of alkynyl include ethynyl, propynyl, butynyl and the like.

  The “C4-20 alkyldienyl” is preferably C4-10 alkyldienyl, and more preferably C4-6 alkyldienyl. Examples of alkyldienyl include 1,3-butadienyl.

  “C6-C18 aryl” is preferably C6-C10 aryl. Examples of aryl include phenyl, 1-naphthyl, 2-naphthyl, indenyl, biphenylyl, anthryl, phenanthryl and the like.

  The “alkyl aryl having 7 to 20 carbon atoms” is preferably alkyl aryl having 7 to 12 carbon atoms. Examples of alkylaryl include o-tolyl, m-tolyl, p-tolyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, o-cumenyl, m-cumenyl, p-cumenyl, and Examples include mesityl.

  The “arylalkyl having 7 to 20 carbon atoms” is preferably arylalkyl having 7 to 12 carbon atoms. Examples of arylalkyl include benzyl, phenethyl, diphenylmethyl, triphenylmethyl, 1-naphthylmethyl, 2-naphthylmethyl, 2,2-diphenylethyl, 3-phenylpropyl, 4-phenylbutyl, and 5-phenylpentyl. Etc.

  The “cycloalkyl having 4 to 20 carbon atoms” is preferably cycloalkyl having 4 to 10 carbon atoms. Examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like.

  The “C4-20 cycloalkenyl” is preferably a C4-10 cycloalkenyl. Examples of cycloalkenyl include cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl and the like.

  “Alkoxy having 2 to 20 carbon atoms” is preferably alkoxy having 2 to 10 carbon atoms, and more preferably alkoxy having 2 to 6 carbon atoms. Examples of alkoxy include ethoxy, propoxy, butoxy, pentyloxy and the like.

  “C6-C20 aryloxy” is preferably C6-C10 aryloxy. Examples of aryloxy include phenyloxy, naphthyloxy, biphenyloxy and the like.

“Alkylthio (—SY ¹ , wherein Y ¹ represents an optionally substituted alkyl having 2 to 20 carbon atoms)” and “alkylsulfonyl (—SO ₂ Y ³ , wherein Y ³ is In the formula (2), Y ¹ and Y ³ are preferably alkyl having 2 to 10 carbons, and may be alkyl having 2 to 6 carbons. More preferably it is. Examples of alkyl include methyl, ethyl, propyl, isopropyl, n-butyl, s-butyl, t-butyl, pentyl, hexyl, dodecanyl and the like.

“Arylthio (—SY ² , wherein Y ² represents aryl having 6 to 18 carbon atoms which may have a substituent)” and “Arylsulfonyl (—SO ₂ Y ⁴ , wherein Y ⁴ is In the formula ( ² ), Y ² and Y ⁴ are preferably aryl having 6 to 10 carbon atoms. Examples of aryl include phenyl, 1-naphthyl, 2-naphthyl, indenyl, biphenylyl, anthryl, phenanthryl and the like.

“C2-C20 hydrocarbon”, “C2-C20 alkoxy”, “C6-C20 aryloxy”, “amino”, “silyl”, “alkylthio”, “arylthio”, “alkyl” Substituents may be introduced into “sulfonyl” and “arylsulfonyl”. Examples of this substituent include ester, carboxyl, amide, alkyne, trimethylsilyl, amino, phosphonyl, thio, carbonyl, nitro, sulfo, imino, halogeno, and alkoxy.
In this case, one or more substituents may be introduced at the substitutable position up to the maximum number that can be substituted, and preferably 1 to 4 substituents may be introduced. When the number of substituents is 2 or more, each substituent may be the same or different.

  Examples of “amino optionally having a substituent” include amino, dimethylamino, methylamino, methylphenylamino, phenylamino and the like.

  Examples of “optionally substituted silyl” include dimethylsilyl, diethylsilyl, trimethylsilyl, triethylsilyl, trimethoxysilyl, triethoxysilyl, diphenylmethylsilyl, triphenylsilyl, triphenoxysilyl, dimethylmethoxy Examples thereof include silyl, dimethylphenoxysilyl, and methylmethoxyphenyl.

  As described above, the organic group is basically described with a monovalent specific example, but the specific example of the divalent organic group is described with a group in which the valence is further increased by one in the above-described monovalent organic group. can do. Similarly, specific examples of the tetravalent organic group can be described using a group obtained by further increasing the valence by three in the monovalent organic group described above. The description of the organic group in the chemical formula represented by the formula (1) described above can also be used as the description of the “organic group” in the chemical formula represented by another formula number.

  The polyamic acid (A) can be obtained by reacting at least the tetracarboxylic dianhydride (a1) and the diamine (a2), but is not limited to the polyamic acid obtained by the production method. . Below, tetracarboxylic dianhydride (a1) and diamine (a2) which can be used in order to obtain a polyamic acid (A) are demonstrated.

1.2.2 Tetracarboxylic dianhydride (a1)
Specific examples of the tetracarboxylic dianhydride (a1) used for the synthesis of the polyamic acid (A) include, for example, 2,2 ′, 3,3′-benzophenonetetracarboxylic dianhydride, 2,3,3 ', 4'-Benzophenone tetracarboxylic dianhydride, 2,2', 3,3'-diphenylsulfone tetracarboxylic dianhydride, 2,3,3 ', 4'-diphenyl sulfone tetracarboxylic dianhydride 2,2 ′, 3,3′-diphenyl ether tetracarboxylic dianhydride, 2,3,3 ′, 4′-diphenyl ether tetracarboxylic dianhydride, ethylene glycol bis (anhydro trimellitate), ethane tetra Carboxylic dianhydride, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, 5- (2,5-di Oxotetrahydrofuryl) -3-methyl And tetracarboxylic dianhydrides such as compounds represented by the following formulas (a1-1) to (a1-73): ru-3-cyclohexene-1,2-dicarboxylic anhydride.

  Among the above specific examples of tetracarboxylic dianhydride, the formulas a1-1, a1-2, a1-5, a1-6, a1-7, a1-8, a1-9, a1-14, a1-15, The compounds represented by a1-16, a1-17, a1-18, and a1-20 are preferable because they have a high solubility in a solvent and can produce a high-concentration screen printing composition. Further, depending on the application of the screen printing composition, high insulation is required. In such a case, the formulas a1-14, a1-15, a1-16, a1-17, a1-18 and a1 It is particularly preferable to use a compound represented by −20 or the like.

  Moreover, the said tetracarboxylic dianhydride may be used individually by 1 type or in combination of 2 or more types. Further, an aromatic tetracarboxylic dianhydride represented by the formula a1-1, a1-2, a1-5, a1-6, a1-7, a1-8 or a1-9 and the formula a1-14, a1-15 , A1-16, a1-17, a1-18 or a1-20 together with the alicyclic tetracarboxylic dianhydride, it is possible to achieve high solubility in solvent and high insulation of polyimide film at the same time Is preferable. Among these, the combination of pyromellitic dianhydride represented by the formula a1-1 and 1,2,3,4-cyclobutanetetracarboxylic dianhydride represented by the formula a1-14, or the formula a1-1 The combination of pyromellitic dianhydride shown and 1,2,3,4-butanetetracarboxylic dianhydride shown by formula a1-18 is preferred, and pyromellitic dianhydride shown by formula a1-1 The combined use of 1,2,3,4-cyclobutanetetracarboxylic dianhydride represented by the formula a1-14 is particularly preferred.

The tetracarboxylic dianhydride (a1) that can be used to synthesize the polyamic acid (A) contained in the screen printing composition is limited to the tetracarboxylic dianhydrides exemplified herein. Without departing from the above, various other forms of tetracarboxylic dianhydride can be used as long as the object of the present invention is achieved.
The tetracarboxylic dianhydride (a1) that can be used for synthesizing the polyamic acid (A) contained in the screen printing composition may be used alone or in combination of two or more. it can. That is, two or more kinds of combinations include the above tetracarboxylic dianhydrides, the above tetracarboxylic dianhydrides and other tetracarboxylic dianhydrides, or a tetracarboxylic acid other than the above tetracarboxylic dianhydrides. Acid dianhydrides can be used.

1.2.3 Diamine (a2)
The diamine (a2) used for the synthesis of the polyamic acid (A) is not particularly limited as long as it has two amino groups. For example, it is represented by the following general formulas (II) to (VIII). Compounds.

式(II)中、Ａ¹は、−(ＣＨ₂)_m−であり、ここでｍは１〜６の整数であり、
式(III)〜(VIII)中、Ａ¹は、それぞれ独立して、単結合、−Ｏ−、−Ｓ−、−Ｓ−Ｓ−、−ＳＯ₂−、−ＣＯ−、−ＣＯＮＨ−、−ＮＨＣＯ−、−Ｃ(ＣＨ₃)₂−、−Ｃ(ＣＦ₃)₂−、−(ＣＨ₂)_m−、−Ｏ−(ＣＨ₂)_m−Ｏ−、又は−Ｓ−(ＣＨ₂)_m−Ｓ−であり、ここでｍは１〜６の整数であり、Ａ²は、それぞれ独立して、単結合、−Ｏ−、−Ｓ−、−ＣＯ−、−Ｃ(ＣＨ₃)₂−、−Ｃ(ＣＦ₃)₂−、又は炭素数１〜３のアルキレンであり、シクロヘキサン環またはベンゼン環に結合している水素は、−Ｆ、又は−ＣＨ₃に置き換えられていてもよい。

In the formula (II), A ¹ is — (CH ₂ ) _m —, where m is an integer of 1 to 6,
In formulas (III) to (VIII), A ¹ each independently represents a single bond, —O—, —S—, —S—S—, —SO ₂ —, —CO—, —CONH—, — _{NHCO -, - C (CH 3} ) 2 -, - C (CF 3) 2 -, - (CH 2) m -, - O- (CH 2) m -O-, or -S- (CH _{2) m} is -S-, where m is an integer from 1 to 6, a ² are each independently a single bond, -O -, - S -, - CO -, - C (CH 3) 2 - , —C (CF ₃ ) ₂ —, or alkylene having 1 to 3 carbon atoms, and hydrogen bonded to the cyclohexane ring or the benzene ring may be replaced with —F or —CH ₃ .

  Examples of the diamine represented by the general formula (II) include diamines represented by the formulas (II-1) to (II-3).

  Examples of the diamine represented by the general formula (III) include diamines represented by the formula (III-1) or (III-2).

  Examples of the diamine represented by the general formula (IV) include diamines represented by the formulas (IV-1) to (IV-3).

  Examples of the diamine represented by the general formula (V) include diamines represented by the formulas (V-1) to (V-5).

  Examples of the diamine represented by the general formula (VI) include diamines represented by the formulas (VI-1) to (VI-30).

  Examples of the diamine represented by the general formula (VII) include diamines represented by the formulas (VII-1) to (VII-6).

  Examples of the diamine represented by the general formula (VIII) include diamines represented by the formulas (VIII-1) to (VIII-11).

  Among the specific examples of the diamine (a2) represented by the general formulas (II) to (VIII), more preferably, the formulas (V-1) to (V-5) and the formulas (VI-1) to (VI) -15), Formula (VI-26), Formula (VI-27), Formulas (VII-1) to (VII-6), and Formulas (VIII-1) to (VIII-11) Is mentioned. More preferable examples include diamines represented by formula (V-1), formula (VI-1), formula (VI-7), formula (VI-10), or formula (VI-13).

  Examples of the diamine (a2) used for the synthesis of the polyamic acid (A) further include a diamine represented by the general formula (IX).

式(IX)中、
Ａ³は、単結合、−Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＯ−、−ＣＯＮＨ−または−(ＣＨ₂)_m−であり、ここで、ｍは１〜６の整数であり、
Ｒ⁶は、ステロイド骨格を有する基、シクロヘキサン環とベンゼン環とからなる群から選ばれる１以上を有する基、または、ベンゼン環に結合している２つのアミノ基の位置関係がパラ位のときは炭素数２〜３０のアルキル、もしくは該位置関係がメタのときは炭素数１〜１０のアルキルまたはフェニルであり、
該アルキルにおいては、任意の−ＣＨ₂−が−ＣＦ₂−、−ＣＨＦ−、−Ｏ−、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−で置き換えられていてもよく、−ＣＨ₃が−ＣＨ₂Ｆ、−ＣＨＦ₂または−ＣＦ₃で置き換えられていてもよく、
該フェニルの環形成炭素に結合している水素は、−Ｆ、−ＣＨ₃、−ＯＣＨ₃、−ＯＣＨ₂Ｆ、−ＯＣＨＦ₂または−ＯＣＦ₃と置き換えられていてもよい。

In formula (IX),
A ³ is a single bond, —O—, —COO—, —OCO—, —CO—, —CONH— or — (CH ₂ ) _m —, wherein m is an integer of 1 to 6,
R ⁶ is a group having a steroid skeleton, a group having one or more selected from the group consisting of a cyclohexane ring and a benzene ring, or when the positional relationship between two amino groups bonded to the benzene ring is para-position An alkyl having 2 to 30 carbon atoms, or an alkyl having 1 to 10 carbon atoms or phenyl when the positional relationship is meta;
In the alkyl, any —CH ₂ — may be replaced by —CF ₂ —, —CHF—, —O—, —CH═CH— or —C≡C—, and —CH ₃ may be —CH ₂ F, -CHF ₂ or -CF ₃ may be substituted,
Hydrogen bonded to the phenyl ring carbon _{is, -F, -CH 3, -OCH 3} , -OCH 2 F, may be replaced with -OCHF ₂ or -OCF _3.

In the general formula (IX), the two amino groups are bonded to the phenyl ring carbon. Preferably, the bonding position relationship between the two amino groups is preferably the meta position or the para position. Each two additional amino group, "R ⁶ -A ³ -" 3-position when the 1-position of the bond position of the 5-position, or 2 position and is preferably bonded to the 5-position.
Examples of the diamine represented by the general formula (IX) include diamines represented by the following general formulas (IX-1) to (IX-11).

In the general formulas (IX-1), (IX-2), (IX-7) and (IX-8), R ¹⁸ is an organic group having 2 to 30 carbon atoms. 12 alkyl or C3-C12 alkoxy is preferable, and C5-C12 alkyl or C5-C12 alkoxy is more preferable. In the general formulas (IX-3) to (IX-6) and the general formulas (IX-9) to (IX-11), R ¹⁹ is —H or an organic group having 1 to 30 carbon atoms. Among these, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons is preferable, and alkyl having 3 to 10 carbons or alkoxy having 3 to 10 carbons is more preferable.

  Examples of the diamine represented by the general formula (IX) further include diamines represented by the following general formulas (IX-12) to (IX-17).

In the general formulas (IX-12) to (IX-15), R ²⁰ is —H or an organic group having 1 to 30 carbon atoms, preferably an alkyl group having 4 to 16 carbon atoms, and an alkyl group having 6 to 16 carbon atoms. Further preferred. In the general formulas (IX-16) and (IX-17), R ²¹ represents —H or an organic group having 1 to 30 carbon atoms, preferably an alkyl group having 6 to 20 carbon atoms, and an alkyl group having 8 to 20 carbon atoms. Is more preferable.

  Examples of the diamine represented by the general formula (IX) further include diamines represented by the following general formulas (IX-18) to (IX-38).

General formula (IX-18), (IX-19), (IX-22), (IX-24), (IX-25), (IX-28), (IX-30), (IX-31) , (IX-36) and (IX-37), R ²² is —H or an organic group having 1 to 30 carbon atoms, preferably alkyl having 1 to 12 carbons or alkoxy having 1 to 12 carbons, More preferred is alkyl having 3 to 12 or alkoxy having 3 to 12 carbon atoms. In addition, the above general formulas (IX-20), (IX-21), (IX-23), (IX-26), (IX-27), (IX-29), (IX-32) to (IX-32) 35) and (IX-38), R ²³ represents —H, —F, alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, —CN, —OCH ₂ F, —OCHF ₂ or —OCF _3. More preferably, alkyl having 3 to 12 carbons or alkoxy having 3 to 12 carbons is used. In the above general formulas (IX-33) and (IX-34), A ⁹ is alkylene having 1 to 12 carbons.

  Examples of the diamine represented by the general formula (IX) further include diamines represented by the following formulas (IX-39) to (IX-48).

  Of the diamines (a2) represented by the general formula (IX), diamines represented by the general formulas (IX-1) to (IX-11) are preferable, and the general formulas (IX-2) and (IX- More preferred are diamines represented by 4), formula (IX-5) and formula (IX-6).

  Examples of the diamine (a2) used in the synthesis of the polyamic acid (A) further include compounds represented by the following general formulas (XI) to (XII).

式(XI)と(XII)中、Ｒ¹⁰は−Ｈまたは−ＣＨ₃であり、Ｒ¹¹はそれぞれ独立して、−Ｈまたは炭素数１〜２０のアルキルもしくは炭素数２〜２０アルケニルであり、Ａ⁶はそれぞれ独立して、単結合、−Ｃ(＝Ｏ)−または−ＣＨ₂−であり、Ｒ¹³およびＲ¹⁴はそれぞれ独立して、−Ｈ、炭素数１〜２０のアルキルまたはフェニルである。

In formulas (XI) and (XII), R ¹⁰ is —H or —CH ₃ , R ¹¹ is independently —H, alkyl having 1 to 20 carbons or alkenyl having 2 to 20 carbons, A ⁶ is each independently a single bond, —C (═O) — or —CH ₂ —, and R ¹³ and R ¹⁴ are each independently —H, alkyl having 1 to 20 carbons or phenyl. is there.

In general formula (XI), it is preferable that one of the two “NH ₂ —Ph—A ⁶ —O—” is bonded to the 3-position of the steroid nucleus and the other is bonded to the 6-position. The two amino groups are each bonded to the phenyl ring carbon, and preferably bonded to the meta position or the para position with respect to the bonding position of A ⁶ .
Examples of the diamine represented by the general formula (XI) include diamines represented by the formulas (XI-1) to (XI-4).

In the general formula (XII), two “NH ₂ — (R ¹⁴ —) Ph—A ⁶ —O—” are each bonded to the phenyl ring carbon, but preferably to the carbon to which the steroid nucleus is bonded. On the other hand, it is bonded to carbon in the meta or para position. The two amino groups are each bonded to the phenyl ring carbon, but are preferably bonded to the meta position or the para position with respect to A ⁶ .
Examples of the diamine represented by the general formula (XII) include diamines represented by the formulas (XII-1) to (XII-8).

  Examples of the diamine (a2) used in the synthesis of the polyamic acid (A) further include compounds represented by the general formula (XIII) or (XIV).

式(XIII)中、Ｒ¹⁵は−Ｈまたは炭素数１〜２０のアルキルであり、該アルキルのうち炭素数２〜２０のアルキルの任意の−ＣＨ₂−は、−Ｏ−、−ＣＨ＝ＣＨ−または−Ｃ≡Ｃ−で置き換えられてもよく、Ａ⁷はそれぞれ独立して−Ｏ−または炭素数１〜６のアルキレンであり、Ａ⁸は単結合または炭素数１〜３のアルキレンであり、環Ｔは１,４−フェニレンまたは１,４−シクロヘキシレンであり、ｈは０または１である。

In the formula (XIII), R ¹⁵ is —H or alkyl having 1 to 20 carbons, and any —CH ₂ — of the alkyl having 2 to 20 carbons among the alkyls is —O—, —CH═CH -Or -C≡C- may be substituted, each A ⁷ is independently -O- or alkylene having 1 to 6 carbon atoms, and A ⁸ is a single bond or alkylene having 1 to 3 carbon atoms. , Ring T is 1,4-phenylene or 1,4-cyclohexylene, and h is 0 or 1.

式(XIV)中、Ｒ¹⁶は炭素数２〜３０のアルキルであり、これらの中でも炭素６〜２０のアルキルが好ましい。Ｒ¹⁷は−Ｈまたは炭素数１〜３０のアルキルであり、これらの中でも炭素１〜１０のアルキルが好ましい。Ａ⁷はそれぞれ独立して−Ｏ−または炭素数１〜６のアルキレンである。

In the formula (XIV), R ¹⁶ is alkyl having 2 to 30 carbons, and among these, alkyl having 6 to 20 carbons is preferable. R ¹⁷ is —H or alkyl having 1 to 30 carbons, and among these, alkyl having 1 to 10 carbons is preferable. A ⁷ is independently —O— or alkylene having 1 to 6 carbon atoms.

In the general formula (XIII), the two amino groups are each bonded to the phenyl ring carbon, but are preferably bonded to the meta position or para to A ⁷ .
Examples of the diamine represented by the general formula (XIII) include diamines represented by the following general formulas (XIII-1) to (XIII-9).

一般式(XIII-1)〜(XIII-3)において、Ｒ²⁴は−Ｈ、炭素数１〜２０のアルキルが好ましく、一般式(XIII-4)〜(XIII-9)においてＲ²⁵は−Ｈ、炭素数１〜１０のアルキルがさらに好ましい。

In the general formulas (XIII-1) to (XIII-3), R ²⁴ is preferably —H and alkyl having 1 to 20 carbon atoms. In the general formulas (XIII-4) to (XIII-9), R ²⁵ is —H. Further, alkyl having 1 to 10 carbon atoms is more preferable.

In the general formula (XIV), the two amino groups are each bonded to the phenyl ring carbon, but are preferably bonded to the meta position or the para position with respect to A ⁷ .
Examples of the diamine represented by the general formula (XIV) include diamines represented by the following general formulas (XIV-1) to (XIV-3).

In the general formulas (XIV-1) to (XIV-3), R ²⁶ is alkyl having 2 to 30 carbons, and among these, alkyl having 6 to 20 carbons is preferable, and R ²⁷ is —H or 1 carbon. -30 alkyl. Among these, -H or alkyl having 1 to 10 carbon atoms is preferable.

  As described above, as the diamine (a2) used for the synthesis of the polyamic acid (A), for example, diamines represented by the general formulas (II) to (XIV) can be used. Can be used. For example, a naphthalene diamine having a naphthalene structure, a fluorene diamine having a fluorene structure, a siloxane diamine having a siloxane bond, or the like can be used alone or mixed with another diamine.

  The siloxane-based diamine is not particularly limited, but those represented by the following general formula (10) can be preferably used.

式(１０)中、Ｒ³およびＲ⁴は、それぞれ独立して、炭素数１〜３のアルキルまたはフェニルであり、Ｒ⁵は、それぞれ独立して、メチレン、フェニレンまたはアルキル置換されたフェニレンであり、ｘはそれぞれ独立して１〜６の整数であり、ｙは１〜７０の整数である。ここで、より好ましいｙは１〜１５の整数である。

In Formula (10), R ³ and R ⁴ are each independently alkyl or phenyl having 1 to 3 carbon atoms, and R ⁵ is each independently methylene, phenylene or alkyl-substituted phenylene. , X are each independently an integer of 1-6, and y is an integer of 1-70. Here, more preferable y is an integer of 1-15.

  Furthermore, Preferably, the diamine represented by the following general formula (11)-(18) may be used as diamine (a2) used for the synthesis | combination of polyamic acid (A).

式(１１)〜(１８)中、Ｒ³⁰およびＲ³¹は、それぞれ独立して、炭素数３〜２０のアルキルである。

In formulas (11) to (18), R ³⁰ and R ³¹ are each independently alkyl having 3 to 20 carbon atoms.

The diamine (a2) that can be used to synthesize the polyamic acid (A) contained in the screen printing composition is not limited to the diamines exemplified in the present specification, and the object of the present invention is achieved. Various other forms of diamine can be used within the range.
The diamine (a2) that can be used for synthesizing the polyamic acid (A) contained in the screen printing composition can be used alone or in combination of two or more. That is, as a combination of two or more kinds, the above diamines, the above diamine and other diamines, or diamines other than the above diamines can be used.

（式中、Ｒ⁷とＲ⁸はそれぞれ独立して、炭素数２〜１００の有機基である。） In order to strengthen the mechanical strength of the polyimide film obtained from the screen printing composition, an aromatic diamine in which two amino groups are bonded to the para-position of the benzene ring, or the 4-position of two anilines. An aromatic diamine having a structure in which is linked with a divalent organic group is particularly preferred.
Specific examples of aromatic diamines in which two amino groups are bonded to the para-position of the benzene ring include aromatic diamines represented by formulas (V-1) and (V-3) to (V-5). It is done.
Specific examples of the aromatic diamine having a structure in which the 4-position of two anilines are linked by a divalent organic group include formula (VI-1), formula (VI-7), formula (VI-10) to (VI -13), formula (VI-27), formula (VII-1) to (VII-6), formula (VIII-1) to (VIII-11), formula (XI-1), formula (XI-2) Formula (XII-1), Formula (XII-2), Formula (XII-5), Formula (XII-7), Formula (XII-8), General Formula (XIII-1) to (XIII-9), And aromatic diamines represented by the general formulas (XIV-1) to (XIIV-3).
Particularly preferably, Formula (V-1), Formula (V-3) to (V-5), Formula (VI-1), Formula (VI-7), Formula (VI-10) to (VI-13) And aromatic diamines represented by the formula (VI-27).
1.5 Other Structural Units Containing Polyamic Acid The polyamic acid (A) may have another structural unit different from the structural unit represented by the general formula (1), for example, the following general formula And polyamic acid having one or more molecular end groups selected from the group of molecular end groups represented by formula (20) or general formula (20).

(In the formula, R ⁷ and R ⁸ are each independently an organic group having 2 to 100 carbon atoms.)

1.2.4 Reaction conditions for synthesizing polyamic acid (A) <monomer ratio>
Polyamic acid (A) can be synthesized, for example, by reacting tetracarboxylic dianhydride (a1) with diamine (a2).
It is preferable to use 0.9-1.1 mol of diamine (a2) with respect to 1 mol of tetracarboxylic dianhydride (a1), and diamine (a2) with respect to 1 mol of tetracarboxylic dianhydride (a1). It is more preferable to use 0.95 to 1.05 mol. It is particularly preferable to use 1 mole (equal mole) of diamine (a2) to 1 mole of tetracarboxylic dianhydride (a1).

<Reaction solvent>
The solvent used when synthesizing the polyamic acid (A) by reacting the tetracarboxylic dianhydride (a1) with the diamine (a2) is particularly limited as long as the polyamic acid (A) can be synthesized. Although not, for example, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate , Cyclohexanone, γ-butyrolactone, N-methyl-2-pyrrolidone, N, N-dimethylformamide and N, N-dimethylacetamide, etc. .
Among these, γ-butyrolactone, N-methyl-2-pyrrolidone, N, N-dimethylformamide and N, N-dimethylacetamide are preferable because the solubility of the polyamic acid (A) is high.
These reaction solvents can be used alone or as a mixed solvent of two or more. In addition to the reaction solvent, other solvents can be mixed and used.

  The reaction solvent is preferably used in an amount of 100 parts by weight or more with respect to a total of 100 parts by weight of the tetracarboxylic dianhydride (a1) and the diamine (a2) because the reaction proceeds smoothly. The reaction is preferably performed at 0 to 100 ° C. for 0.2 to 20 hours.

<Order of addition to reaction system>
Moreover, it does not specifically limit to the addition order to the reaction system of a reaction raw material. That is, tetracarboxylic dianhydride (a1) and diamine (a2) are simultaneously added to the reaction solvent, and after dissolving diamine (a2) in the reaction solvent, tetracarboxylic dianhydride (a1) is added. Any method can be used, such as adding diamine (a2) after dissolving tetracarboxylic dianhydride (a1) in the reaction solvent.

1.2.5 Concentration of Polyamic Acid (A) The concentration of the polyamic acid (A) in the screen printing composition is preferably 5 to 60% by weight, and more preferably 10 to 40% by weight. Within this concentration range, the mechanical strength of the coating film formed from the screen printing composition is strong, and the heat resistance, chemical resistance and flatness are good.

1.2.6 Polyamic acid (A) weight average molecular weight Polyamic acid (A) having a weight average molecular weight of 80,000 to 500,000 is a polyimide film having a uniform thickness without causing mesh residue or bleeding. The resulting polyimide film has a high mechanical strength, has good flexibility without cracking, and is preferred as a composition for screen printing.
The polyamic acid (A) having a weight average molecular weight of 80,000 or more is a polyamic acid having a strong mechanical strength of the resulting polyimide film, good flexibility without cracks, and a weight average molecular weight of 500,000 or less. In (A), the viscosity can be appropriately adjusted for screen printing, and a polyimide film having a uniform film thickness can be obtained without causing mesh residue or blurring. The polyamic acid (A) can be preferably used as a composition for screen printing.
In order to further improve the screen printability and the mechanical strength of the resulting polyimide film, the polyamic acid (A) preferably has a weight average molecular weight of 100,000 to 200,000, more preferably 120,000 to 180,000.

  The weight average molecular weight of the polyamic acid (A) can be measured by a gel permeation chromatography (GPC) method. Specifically, the obtained polyamic acid (A) is diluted with N, N-dimethylformamide (DMF) so that the polyamic acid concentration is about 1% by weight, and columns G4000HXL, G3000HXL, G2500HXL manufactured by Tosoh Corporation are used. And G2000HXL, it can be obtained by measuring by gel permeation chromatography (GPC) method using DMF as a developing agent and converting to polystyrene.

1.3 Epoxy resin (B)
Specific examples of the epoxy resin (B) include N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, Examples thereof include one or more compounds selected from the group consisting of N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane and compounds represented by the following formulas (2) to (4). Epoxy resin (B) may be used alone or in combination of two or more.

  Among these, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetra One or more compounds selected from glycidyl-4,4′-diaminodiphenylmethane are preferred because the resulting polyimide film has particularly good mechanical strength and flatness.

  The concentration of the epoxy resin (B) in the screen printing composition is preferably 5 to 60% by weight, and more preferably 10 to 40% by weight. Within this concentration range, the mechanical strength of the coating film formed from the composition for screen printing is strong, and the heat resistance, chemical resistance and flatness are good.

1.4 Metal oxide fine particles (C)

The metal oxide fine particles (C) may be oxide fine particles made of one kind of metal or oxide (ie, complex oxide) made of two or more metals. Specific examples of oxides composed of one kind of metal include oxides of metals such as silicon, aluminum, magnesium, zirconium, and titanium, silica (SiO ₂ ), alumina (Al ₂ O ₃ ), and titania (TiO ₂ ). ₂ ), zirconia (ZrO ₂ ) and the like. Specific examples of the composite oxide include silica-alumina composite oxide, silica-titania composite oxide, silica-zirconia composite oxide, silica-magnesia composite oxide, and alumina-magnesia composite, which are composite oxides of the above metals. Binary composite oxides such as oxide, ternary composite oxides such as silica-alumina-magnesia composite oxide, silica-alumina-titania composite oxide, silica-titania-magnesia composite oxide, etc. . Among these metal oxide fine particles, metal oxide fine particles containing silica fine particles as a main component (that is, containing 60 to 100% by weight) are preferable.

  Metal oxide fine particles (C) are molten metal oxide powder, crushed metal oxide, fumed metal oxide synthesized by high temperature gas phase reaction (fumed metal oxide), and metal oxide synthesized by wet method. Among these, fumed metal oxides (fumed metal oxides) are preferable.

  The metal oxide fine particles (C) need not be surface-treated, but those having a surface treated with silazanes and / or a silane coupling agent are preferred.

  Silazanes are, for example, silazanes such as hexamethyldisilazane (HMDS) and hexaphenyldisilazane, or combinations of two or more thereof. Among these, hexamethyldisilazane suppresses the aggregation of silica, tilts acidic silica to basic, improves affinity for organic matter, improves uniformity, and stabilizes in screen printing compositions. It is preferable at the point which improves property.

  The silane coupling agent is, for example, a compound having at least one active group (reactive organic functional group) selected from the group consisting of amino, glycidyl, mercapto, ureido, hydroxy and alkoxy, or a combination thereof (for example, alkoxy Group and other reactive functional groups). Specific examples of the silane coupling agent include epoxy functional group-containing organoalkoxysilanes such as γ-glycidoxypropyltriethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, aminopropyltriethoxysilane Aminofunctional group-containing organoalkoxysilanes such as ureidopropyltriethoxysilane and N-phenylaminopropyltrimethoxysilane, arylalkoxysilanes such as phenyltrimethoxysilane, alkylalkoxysilanes such as methyltrimethoxysilane and octadecyltrimethoxysilane , Alkenylalkoxysilanes such as vinyltrimethoxysilane and allyltrimethoxysilane, mercaptofunctional group-containing organoalkoxysilanes such as γ-mercaptopropyltrimethoxysilane, etc. And the like.

  As the metal oxide fine particles (C), commercially available products such as R812, RX200, NX90, and NAX50 manufactured by Nippon Aerosil Co., Ltd. are preferable, and R812 is most preferable.

  The average particle diameter of the metal oxide fine particles (C) is preferably 0.001 μm to 10 μm, and more preferably 0.005 μm to 0.040 μm. When the average particle diameter is in this range, good thixotropy can be obtained, and a polyimide film having a uniform thickness can be obtained without causing mesh residue or bleeding.

  The concentration of the metal oxide fine particles (C) in the screen printing composition is preferably 0.1 to 10% by weight, and more preferably 1.0 to 5.0% by weight. Within this concentration range, the mechanical strength of the coating film formed from the composition for screen printing is strong, and the heat resistance, chemical resistance and flatness are good.

1.5 Solvent (D)
The screen printing composition can be obtained, for example, by dissolving the polyamic acid (A) and the epoxy resin (B) in the solvent (D) and then mixing the metal oxide fine particles (C). Accordingly, the solvent (D) contained in the screen printing composition is not particularly limited as long as it is a solvent that can dissolve the polyamic acid (A) and the epoxy resin (B) and disperse the metal oxide fine particles (C). Not. Further, even if the solvent alone does not dissolve the polyamic acid (A) and the epoxy resin (B), the solvent for the screen printing composition (by satisfying the above condition by mixing with another solvent ( D) can be used.

  Specific examples of the solvent (D) include N-methyl-2-pyrrolidone, dimethylimidazolidinone, N-methylcaprolactam, N-methylpropionamide, N, N-dimethylacetamide, dimethyl sulfoxide, N, N-dimethylformamide. N, N-diethylformamide, diethylacetamide, γ-butyrolactone, ethyl lactate, 3-methyl-3-methoxybutanol, tetralin, isophorone, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol dimethyl ether, Diethylene glycol methyl ethyl ether, triethylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol Examples thereof include nomethyl ether acetate, dipropylene glycol monomethyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, diethyl malonate, ethanol, 2-propanol, dioxane, and ethylene glycol.

Among these solvents, for example, γ-butyrolactone, N-methyl-2-pyrrolidone, N, N-dimethylformamide and / or N, N-dimethylacetamide are used as the solvent (D in view of solubility of the polyamic acid (A). ) Is preferably included.
These solvents may be used alone or in combination of two or more. Further, the concentration of the solvent is preferably 20 to 89.9% by weight. More preferably, it is 25-85 weight%, More preferably, it is 30-80 weight%.

1.6 Water Content in Screen Printing Composition The water content in the screen printing composition is not particularly limited, but is preferably 10,000 ppm or less, and more preferably 5,000 ppm or less in terms of the stability of the polyamic acid (A). These water contents are preferable because the viscosity of the screen printing composition is small and excellent in storage stability.

1.7 Additives added to the screen printing composition Depending on the intended properties, the screen printing composition may contain a surfactant, an antistatic agent, a coupling agent in addition to the main components described above. , Antifoaming agents, epoxy hardeners such as trimellitic acid, aminosilicon compounds, solvents, pH adjusters, rust inhibitors, antiseptics, antifungal agents, antioxidants, anti-reduction agents, evaporation accelerators, chelating agents Additives such as colorants such as water-soluble polymers, conductive fillers, pigments and dyes can be selected and added as necessary.

(1) Surfactant When it is desired to improve the applicability of the screen printing composition, a surfactant suitable for the purpose may be added. Specific examples of surfactants include trade names “Byk-300”, “Byk-306”, “Byk-335”, “Byk-310”, “Byk-341”, “Byk-344”, “Byk- Silicone surfactants such as “370” (by Big Chemie); acrylics such as “Byk-354”, “ByK-358” and “Byk-361” (by Big Chemie) Fluorine-based surfactants such as trade-name surfactants, trade names “DFX-18”, “Factent 250”, “Factent 251” (manufactured by Neos Co., Ltd.). These surfactants may be used alone or in combination of two or more.
The surfactant is used, for example, to improve the wettability, leveling property, or coating property to the base substrate, and the surfactant content basically supplements the main component alone. Or supplemented with other additives to adjust the content of all components to 100% by weight of the screen printing composition, preferably 0.01 to 1 based on the total weight of the screen printing composition. % By weight.

(2) Antistatic agent The antistatic agent that may be added to the screen printing composition is not particularly limited, and 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. These antistatic agents may be used alone or in admixture of two or more.
The antistatic agent is used, for example, to prevent electrification, and the content of the antistatic agent is basically made up of the above main components alone or together with other additives to make up all the components. The content is adjusted to be 100% by weight of the screen printing composition, and is preferably 0.01 to 1% by weight based on the total weight of the screen printing composition.

(3) Coupling agent The coupling agent that may be added to the screen printing composition is not particularly limited, and a known coupling agent can be used. The coupling agent is preferably a silane coupling agent, and specific examples include trialkoxysilane compounds and dialkoxysilane compounds. Preferably, for example, γ-vinylpropyltrimethoxysilane, γ-vinylpropyltriethoxysilane, γ-acryloylpropylmethyldimethoxysilane, γ-acryloylpropyltrimethoxysilane, γ-acryloylpropylmethyldiethoxysilane, γ-acryloylpropyl Triethoxysilane, γ-methacryloylpropylmethyldimethoxysilane, γ-methacryloylpropyltrimethoxysilane, γ-methacryloylpropylmethyldiethoxysilane, γ-methacryloylpropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycyl Sidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropylmethyl Rudimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-aminoethyl-γ-iminopropylmethyldimethoxysilane, N-aminoethyl-γ-aminopropyl Trimethoxysilane, N-aminoethyl-γ-aminopropyltodiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropylmethyl Dimethoxysilane, N-phenyl-γ-aminopropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-mercaptopro Le triethoxysilane, .gamma. isocyanate propyl methyl diethoxy silane, .gamma. isocyanate propyl triethoxysilane and the like. Among these, γ-vinylpropyltrimethoxysilane, γ-acryloylpropyltrimethoxysilane, γ-methacryloylpropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, and the like can be given.

  These coupling agents may be used alone or in combination of two or more. The coupling agent content is basically adjusted by supplementing the main component alone or with other additives so that the total component content is 100% by weight of the screen printing composition. Is preferably 0.01 to 3% by weight, based on the total weight of the screen printing composition.

(4) Epoxy hardener The epoxy hardener which may be added to the composition for screen printing is not specifically limited, A well-known epoxy hardener can be used. Specific examples include organic acid dihydrazide compounds, imidazole and its derivatives, dicyandiamide, aromatic amines, polyvalent carboxylic acids, and polyvalent carboxylic acid anhydrides. 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 melic acid and acid anhydrides such as 1,2,4-cyclohexanetricarboxylic acid-1,2-anhydride. Among these, trimellitic acid and 1,2,4-cyclohexanetricarboxylic acid-1,2-anhydride having good transparency are preferable.

  These epoxy curing agents may be used alone or in combination of two or more. The content of the epoxy curing agent is basically adjusted by supplementing the above main component alone or with other additives so that the content of all components is 100% by weight of the screen printing composition. However, it is preferably 0.2 to 5% by weight based on the total weight of the screen printing composition.

(5) Aminosilicon compound The aminosilicon compound that may be added to the composition for screen printing is not particularly limited, and a known aminosilicon compound can be used. Specific examples include paraaminophenyltrimethoxysilane, paraaminophenyltriethoxysilane, metaaminophenyltrimethoxysilane, metaaminophenyltriethoxysilane, aminopropyltrimethoxysilane, and aminopropyltriethoxysilane. These aminosilicon compounds may be used alone or in combination of two or more.
The aminosilicon compound is used, for example, to improve adhesion to the substrate, and the content of the aminosilicon compound is basically supplemented by supplementing the main component alone or with other additives. The content of all the components is adjusted to be 100% by weight of the screen printing composition, but is preferably 0.05 to 2% by weight based on the total weight of the screen printing composition.

(6) Other additives The composition for screen printing is a soluble polyimide, polyester, acrylic acid polymer within a range that does not impair the object of the present invention (preferably within 20% by weight based on the total amount of the composition for screen printing). A polymer component such as an acrylate polymer may be mixed.
In addition, the composition for screen printing includes polyamide which is a reaction product of dicarboxylic acid or its derivative and diamine, tetracarboxylic dianhydride, polyamideimide which is a reaction product of dicarboxylic acid or its derivative and diamine, etc. These polymer components can be added within a range not impairing the object of the present invention.

2 Polyimide film of the present invention The polyimide film or the patterned polyimide film of the present invention is obtained by applying the above-described screen printing composition to the substrate surface by screen printing and heat-treating it with a hot plate or oven. Alternatively, it can be obtained as a film having a predetermined pattern (for example, a line). In addition, the formation of the polyimide film is not limited to the heat treatment, and may be a treatment such as UV treatment, ion beam, electron beam, or gamma ray.

<Application of composition for screen printing>
The application method of the composition for screen printing is implemented in the following steps. First, the surface of the substrate is covered with a whole surface opening or a mask having openings of a predetermined pattern, and the composition for screen printing is put into a squeegee part of a screen printer. Next, the screen printing composition is filled in the opening of the masking member by moving the squeegee on the mask while applying pressure to the screen printing composition (filling step). Next, the mask is removed. Thus, the screen printing composition can be applied to the surface of the substrate.

<Formation of polyamic acid film>
After the composition for screen printing is applied on the substrate, the film of polyamic acid can be formed by removing the solvent by evaporating it by heating with a hot plate or an oven, that is, drying. Heating conditions vary depending on the type and mixing ratio of each component, but a film of polyamic acid is usually formed at 70 to 120 ° C. for 5 to 15 minutes when using an oven and 1 to 5 minutes when using a hot plate. .

<Formation of polyimide film>
After forming the polyamic acid film, heat at 180 to 350 ° C., preferably 200 to 300 ° C. to imidize the polyamic acid, 30 to 90 minutes when using an oven, 5 to 30 minutes when using a hot plate A polyimide film can be obtained by processing. When the polyamic acid film is formed in a pattern, 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 is an insulating film excellent in heat resistance and electrical insulation. The polyimide film of the present invention is preferable since the carboxylic acid of the polyamic acid and the epoxy resin react simultaneously with imidization and become an insulating film that is relatively tough and excellent in chemical resistance, flatness, adhesion, and sputtering resistance. .

3 Film Substrate of the Present Invention The film substrate of the present invention is, for example, the entire surface or a predetermined pattern (line shape etc.) of the screen printing composition of the present invention by screen printing on a substrate such as a polyimide film on which wiring is formed. ), And then drying the substrate, followed by heat treatment to form a polyimide film.

4 Electronic Component of the Present Invention The electronic component of the present invention can be obtained, for example, by applying the screen printing composition of the present invention to a whole surface or a predetermined pattern (line) on a film substrate such as a polyimide film on which wiring has been previously formed. The film substrate is then dried and further subjected to heat treatment to form a polyimide film. The electronic component thus obtained becomes a flexible electronic component coated with an insulating polyimide film.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention, this invention is not limited to these Examples.

  The names of tetracarboxylic dianhydride (a1), diamine (a2), epoxy resin (B), and solvent (D) used in Examples and Comparative Examples are abbreviated. This abbreviation is used in the following description.

Tetracarboxylic dianhydride (a1)
PMDA: pyromellitic dianhydride CBDA: 1,2,3,4-cyclobutanetetracarboxylic dianhydride BDA: 1,2,3,4-butanetetracarboxylic dianhydride ODPA: 3,3′-4 , 4'-Diphenyl ether tetracarboxylic dianhydride

Diamine (a2)
DDE: 4,4′-diaminodiphenyl ether DDM: 4,4′-diaminodiphenylmethane DDEt: 4,4′-diaminodiphenylethane DDS: 4,4′-diaminodiphenylsulfone

式(５)中、ｎは０〜１０の整数である。 Epoxy resin (B)
TGDDM: N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane jER828: Compound represented by the following general formula (5)

In formula (5), n is an integer of 0-10.

Solvent (D)
NMP: N-methyl-2-pyrrolidone GBL: γ-butyrolactone

[Example 1] Screen printing composition (1)
When a raw material was charged as shown below into a 300 ml four-necked flask equipped with a thermometer, a stirrer, a raw material charging port, and a nitrogen gas inlet, the mixture was stirred at 40 ° C. for 5 hours under a dry nitrogen stream. A 15% by weight solution of polyamic acid was obtained. The weight average molecular weight measured by GPC of this solution was 154,000.
Ingredient (a1) PMDA 3.213 g
Ingredient (a1) CBDA 2.889 g
Ingredient (a2) DDE 5.899 g
Ingredient (D) NMP 68.0 g
To this solution, 10.0 g of TGDDM of component (B), 4.0 g of silica fine particles of component (C) (product name: Aerosol R812, average particle size 0.007 μm), antifoaming agent (Toray 1.0 g of Dow Corning, trade name: 56 additive) was mixed to obtain a composition for screen printing (1). The viscosity of the obtained screen printing composition was 8,500 mPa · s (25 ° C.).

The weight average molecular weight of the polyamic acid was determined by diluting the obtained polyamic acid with a dilute solution (phosphoric acid / DMF = 1.25 / 100: weight ratio) so that the polyamic acid concentration was about 1% by weight. Using Chromatopack C-R7A (manufactured by Shimadzu Corporation), the diluted solution was measured by the GPC method using a developing agent, and was calculated by polystyrene conversion. The column was used by connecting GF-310HQ (manufactured by Showa Denko KK) and GF-510HQ (manufactured by Showa Denko KK) under the conditions of a column temperature of 40 ° C. and a flow rate of 0.5 ml / min.
The viscosity of the screen printing composition was measured with a cone plate rheometer (Brookfield R / S +).

[Example 2] Screen printing composition (2)
When a raw material was charged as shown below into a 300 ml four-necked flask equipped with a thermometer, a stirrer, a raw material charging port, and a nitrogen gas inlet, the mixture was stirred at 40 ° C. for 5 hours under a dry nitrogen stream. A 15% by weight solution of polyamic acid was obtained. The weight average molecular weight measured by GPC of this solution was 92,000.
Ingredient (a1) PMDA 3.205 g
Ingredient (a1) BDA 2.911 g
Ingredient (a2) DDE 5.884 g
Ingredient (D) NMP 68.0 g
To this solution, 10.0 g of TGDDM of component (B), 4.0 g of silica fine particle “Aerosol R812” of component (C) and 1.0 g of defoaming agent “56 additive” were mixed, and the composition for screen printing ( 2) was obtained. The viscosity of the obtained screen printing composition was 8,000 mPa · s (25 ° C.).

[Comparative Example 1] Screen printing composition (E1)
When a raw material was charged as shown below into a 300 ml four-necked flask equipped with a thermometer, a stirrer, a raw material charging port, and a nitrogen gas inlet, the mixture was stirred at 40 ° C. for 5 hours under a dry nitrogen stream. A 33% by weight solution of polyamic acid was obtained. The weight average molecular weight measured by GPC of this solution was 47,000.
Ingredient (a1) ODPA 10.25 g
Ingredient (a2) DDS 16.41 g
Ingredient (D) NMP 40.0 g
Ingredient (D) GBL 13.3 g
To this solution, 10.0 g of TGDDM of component (B), 4.0 g of silica fine particle “Aerosol R812” of component (C) and 1.0 g of defoaming agent “56 additive” were mixed, and the composition for screen printing ( E1) was obtained. The viscosity of the obtained screen printing composition was 2,000 mPa · s (25 ° C.).

[Examples 3 to 5, Comparative Examples 2 to 5]
Screen printing compositions (3) to (5), screen printing compositions (E2) to (E5)
A screen printing composition was prepared under the same conditions as in Example 1 except that the raw materials were charged as shown in Tables 1 and 2, and the screen printing compositions (3) to (5), the screen printing composition ( E2) to (E5) were obtained.
The weight average molecular weight and the viscosity at 25 ° C. of the polyamic acid (A) of the obtained screen printing compositions (3) to (5) and the screen printing compositions (E2) to (E5) are the same as those in Example 1. Measured under conditions. These measurement results were as shown in Tables 1 and 2.

  All screen printing compositions were mixed with 1.0 g of the antifoam “56 additive”.

[Example 6]
Formation of Polyimide Film Using Screen Printing Composition (1) and Evaluation of Flexibility <Formation of Line Polyimide Film by Screen Printing>
The composition for screen printing (1) prepared in Example 1 was applied on a substrate (Toray DuPont, Kapton 200H (thickness 50 μm)) with a screen printing device (Toray Seiki, SERIA SSA-PC250E). Coating was performed using a line and space screen plate having a width of 1 mm and a length of 5 cm. The substrate was dried on an 80 ° C. hot plate for 5 minutes, and then heated in an oven at 230 ° C. for 30 minutes to obtain an insulating polyimide film formed in a line shape.
The line width and edge linearity of the obtained polyimide film were observed with an optical microscope, and the film thickness was measured. The film thickness was determined by using a stylus film thickness meter (manufactured by KLA-Tencor Japan Co., Ltd., α step 200), and taking the average value of the measured values at three locations as the film thickness. The line width and film thickness of the obtained polyimide film were 1.2 mm and 10 μm, respectively. The line width was almost the same as when applied, the linearity of the edge of the line was good, and the line had a sufficient thickness.

<Formation of square patterned polyimide film by screen printing>
A square pattern-shaped polyimide film was obtained under the same conditions except that 1 mm × 1 mm, 5 mm × 5 mm, and 10 mm × 10 mm square pattern screen plates were used instead of the line and space screen plates having a width of 1 mm and a length of 5 cm. The optical micrograph of the obtained polyimide film having a 10 mm × 10 mm square pattern was as shown in FIG.

<Flexibility of polyimide film (folding resistance)>
The screen printing composition (1) prepared in Example 1 was applied onto a substrate (manufactured by Toray DuPont Co., Ltd., Kapton 200H (thickness 50 μm)) using an applicator. After drying at 50 ° C. for 30 minutes using a hot plate, the substrate was heated in an oven at 230 ° C. for 30 minutes to form a film on one side of the substrate. A test sample was produced by cutting the substrate into a width of 1.5 cm and a length of 13 cm so that the TD direction (Transverse direction) of the substrate was the length direction of the test sample.
The test sample was a folding resistance tester (manufactured by Toyo Seiki Co., Ltd., MIT-DA) with a bending surface with a curvature radius of 0.38 mm, a bending angle of 135 °, a tension of 4.9 N, and a test temperature of 25 ° C. Bending was performed at a speed of 175 times per minute, and the presence or absence of cracks was observed at a predetermined number of times.
The result of flexibility was evaluated as follows.
◎: When no crack occurs after 1000 times ○: No crack occurs after 100 times, but cracks are observed after 1000 times Δ: No cracks occur after 50 times, but cracks are observed after 100 times ×: When a crack is observed after 50 times

[Comparative Example 6]
Formation of polyimide film using composition for screen printing (E1) and evaluation of flexibility

<Formation of line-shaped polyimide film by screen printing>
An insulating polyimide film formed in a line was obtained under the same conditions as in Example 6 except that the screen printing composition (E1) prepared in Comparative Example 1 was used.
The obtained polyimide film was evaluated under the same conditions as in Example 6. As a result, the line width of the polyimide film was 1.5 mm, which was significantly wider than the width when applied. Moreover, the linearity of the edge of the line of the obtained polyimide film was insufficient, and there was a jaggedness. Furthermore, the film thickness of the obtained polyimide film line was 5 μm, and a sufficient thickness could not be obtained.

<Formation of square patterned polyimide film by screen printing>
A square pattern-shaped polyimide film was obtained under the same conditions except that 1 mm × 1 mm, 5 mm × 5 mm, and 10 mm × 10 mm square pattern screen plates were used instead of the line and space screen plates having a width of 1 mm and a length of 5 cm. The optical micrograph of the obtained polyimide film having a 10 mm × 10 mm square pattern was as shown in FIG.

<Flexibility of polyimide film (folding resistance)>
A fold resistance test sample was prepared under the same conditions as in Example 6 except that the screen printing composition (E1) prepared in Comparative Example 1 was used.
The test sample was bent under the same conditions as in Example 6, and the presence or absence of cracks was observed a predetermined number of times.

[Examples 7 to 10, Comparative Examples 7 to 10]
Formation of Polyimide Film Using Screen Printing Compositions (2) to (5) and Screen Printing Compositions (E2) to (E5) and Evaluation of Flexibility Each of the screen printing compositions shown in Table 3 is used. The insulating polyimide film formed in the line shape which concerns on Examples 7-10 and Comparative Examples 7-10 was obtained on the same conditions as Example 6 except having carried out. Further, a folding resistance test sample was prepared under the same conditions as in Example 6, bent, and observed for the presence or absence of cracks at a predetermined number of times. The results are shown in Table 3.
As shown in Table 3, the polyimide films according to Examples 6 to 10 had good linearity at the edge of the line, and the line had a sufficient thickness.

*) After applying and drying the screen printing composition (E4) of Comparative Example 9 on the substrate, it was heated in an oven at 230 ° C., and the resulting polyimide film became cloudy and the film became non-uniform. Was not evaluated.

  Examples of the utilization method of the present invention include a coverlay for a flexible wiring board, an insulating film, and an electronic component using the same.

1 is an optical micrograph of the polyimide film obtained in Example 6. FIG. FIG. 2 is an optical micrograph of the polyimide film obtained in Comparative Example 6.

Claims (9)

A polyamic acid (A) having a structural unit represented by the following general formula (1) having a weight average molecular weight of 80,000 to 500,000, an epoxy resin (B), metal oxide fine particles (C) having an average particle size of 0.001 μm to 10 μm, and A composition for screen printing containing a solvent (D), wherein the epoxy resin (B) is N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-di) Glycidylaminomethyl) cyclohexane, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane and one or more selected from the group consisting of compounds represented by the following formulas (2) to (4) A composition for screen printing, comprising a compound.

(In formula (1), R ¹ and R ² are each independently an organic group having 2 to 100 carbon atoms.)   The composition for screen printing according to claim 1, wherein the polyamic acid (A) has a weight average molecular weight of 100,000 to 200,000.   The epoxy resin (B) is N, N, N ′, N′-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ′, N The composition for screen printing according to claim 1 or 2, comprising one or more compounds selected from '-tetraglycidyl-4,4'-diaminodiphenylmethane.   Based on the total amount of the composition for screen printing, the polyamic acid (A) is 5 to 60% by weight, the epoxy resin (B) is 5 to 60% by weight, the metal oxide fine particles (C) are 0.1 to 10% by weight, The composition for screen printing in any one of Claims 1-3 containing 20-89.9 weight% of solvents (D). As tetracarboxylic dianhydride (a1), pyromellitic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2,3,4-butanetetracarboxylic dianhydride And at least one selected from the group consisting of 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenylethane as diamine (a2), and at least one selected from the group consisting of A polyamic acid (A) having a weight average molecular weight of 80,000 to 500,000, obtained using
As the epoxy resin (B), N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane,
A composition for screen printing comprising, as metal oxide fine particles (C), silica fine particles having an average particle size of 0.001 μm to 10 μm, and N-methyl-2-pyrrolidone as a solvent (D).   A polyimide film or a patterned polyimide film obtained from the composition for screen printing according to claim 1.   A step of applying the screen printing composition according to any one of claims 1 to 5 by screen printing to form a polyamic acid film, and a step of treating the formed polyamic acid film to form a polyimide film A polyimide film or a patterned polyimide film obtained through the process.   A film substrate in which the polyimide film or patterned polyimide film according to claim 7 is formed on a substrate.   An electronic component having the film substrate according to claim 8.

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