JP2011148862A - Thermosetting resin composition, method for forming protective film of flexible wiring board and flexible wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermosetting resin composition having sufficient flame retardancy even when being free from a halogen-based flame retardant, capable of sufficiently suppressing the elusion of a cured film component into a Sn plating liquid, causing little warp after the curing, and enabling a film having sufficient insulation reliability at a high temperature in high humidity to be formed by a printing method, to provide a method for forming the protective film of a flexible wiring board by using the thermosetting resin composition, and to provide the flexible wiring board. <P>SOLUTION: The thermosetting resin composition contains (A) a resin having an acid anhydride group and/or a carboxy group in the molecule, (B) an epoxy resin, (C) a phosphazene compound, (D) an inorganic filler and (E) a rust-preventing agent. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermosetting resin composition, a method for forming a protective film for a flexible wiring board using the same, and a flexible wiring board.

  In recent years, in the field of electronic components, polyimide resin, polyamide imide resin, and polyamide resin are used as resins excellent in heat resistance, electrical characteristics, and moisture resistance in response to miniaturization, thinning, and high speed, instead of epoxy resin. in use. However, since these resins have a rigid resin structure and a cured film lacks flexibility, when used as a thin film substrate, the cured substrate tends to warp greatly and have poor flexibility. .

  In order to improve the warpage and flexibility of the above-mentioned resins, it has been studied so far to modify the resin to make it flexible and to have a low elastic modulus, and various modified polyamideimide resins have been proposed. (See, for example, Patent Documents 1, 2, and 3).

  On the other hand, recently, printed wiring boards used for electric and electronic devices are required to have flame retardancy from the viewpoint of preventing fire and maintaining safety. Until now, in order to ensure the flame retardance of a flexible substrate, the halogen-type flame retardant has been used (for example, refer patent documents 4 and 5). However, halogen-based flame retardants may generate harmful gases during combustion, and problems such as environmental pollution during combustion have not been solved, and the use of materials that do not use these has been desired.

  As a flame-retardant resin composition not using a halogen-based flame retardant, a resin composition utilizing a dehydration endothermic reaction or carbonized film formation by adding a metal oxide, a metal hydroxide or the like is known (for example, Patent Document 6). See).

JP 62-106960 A Japanese Patent Laid-Open No. 8-12763 JP-A-7-196798 JP 2002-249639 A Japanese Patent Laid-Open No. 2003-213078 JP 2008-133418 A

  By the way, in the field of permanent resist, PCT (abbreviation of “pressure cooker test”) is known as a test for evaluating high-temperature moisture resistance. In this test, a resist is formed on a wiring board and the resistance when energized for a certain period of time under high temperature and high humidity is measured to evaluate whether the resist maintains sufficient insulation.

  In order to obtain a film-forming material with excellent insulation reliability, the present inventors introduced an acid anhydride group and / or a carboxyl group capable of reacting with an epoxy resin in order to improve the adhesion to a wiring or a substrate. The use of the modified polyamideimide resin was examined. In these studies, the present inventors, when an inorganic filler such as a metal oxide or a metal hydroxide is added to the resin composition containing the resin, the curing reaction is accelerated, and the gel over time It has been found that there is a problem in storage stability such as deterioration of printability due to increase in viscosity and increase in viscosity, and warping after curing increases.

  The present invention has been made in view of the above circumstances, has sufficient flame retardancy even when it does not contain a halogen-based flame retardant, and sufficiently suppresses elution of the cured film component into the Sn plating solution. Thermosetting resin composition capable of forming a film with low warpage after curing and sufficient insulation reliability under high temperature and high humidity by a printing method, and flexible using the thermosetting resin composition It is an object to provide a method for forming a protective film on a wiring board and a flexible wiring board.

  In order to solve the above-mentioned problems, the present inventors have intensively studied. As a result, by using a phosphazene compound and a rust inhibitor in combination, the gelation of a resin having an acid anhydride group and / or a carboxyl group can be suppressed. The elution of the cured film component into the plating solution is not observed, the warp after curing is small, flame resistance, and sufficient insulation reliability under high temperature and high humidity can be successfully formed by the printing method, this book The invention has been completed.

  That is, the thermosetting resin composition of the present invention comprises (A) a resin having an acid anhydride group and / or carboxyl group in the molecule, (B) an epoxy resin, (C) a phosphazene compound, and (D). An inorganic filler and (E) a rust preventive agent are contained.

  According to the thermosetting resin composition of the present invention, by having the above-described configuration, it is difficult to cause gelation or increase in viscosity over time while having sufficient flame retardancy, and the cured film component to the Sn plating solution Elution is not recognized, a warp after curing is small, and a film having excellent insulation reliability under high temperature and high humidity can be formed by a printing method.

［一般式（１）中、複数個のＲはそれぞれ独立に炭素数１〜２０のアルキレン基を示し、Ｘは、２価の有機基を示し、ｍ及びｎは、それぞれ独立に１〜３０の整数を示し、ｎが２以上の場合、ｎ個のＸは同一であっても異なっていてもよい。］ Furthermore, from the viewpoint of further improving the heat resistance, electrical properties, moisture resistance and flexibility of the cured film, the resin (A) has a structure represented by the following general formula (1). Is preferred.

[In General Formula (1), a plurality of R's each independently represents an alkylene group having 1 to 20 carbon atoms, X represents a divalent organic group, and m and n each independently represents 1 to 30 carbon atoms. When an integer is shown and n is 2 or more, the n Xs may be the same or different. ]

  The thermosetting resin composition of this invention can be used in order to form the protective film of a flexible wiring board. When the thermosetting resin composition of the present invention is used to form a protective film on a wiring pattern of a flexible wiring board, a coating film having a good shape can be formed by printing, and a halogen flame retardant can be used. Form a protective film that has excellent flame retardancy without use, no elution of cured film components into the Sn plating solution, little warping after curing, and excellent insulation reliability under high temperature and high humidity. Can do.

  The method for forming a protective film for a flexible wiring board of the present invention includes a first step of printing the thermosetting resin composition of the present invention on the wiring pattern of the flexible wiring board provided with the wiring pattern; A second step of thermally curing the thermosetting resin composition thus formed to form a protective film.

  According to the method for forming a protective film of a flexible wiring board of the present invention, it is difficult to use a halogen-based flame retardant by going through the first and second steps using the thermosetting resin composition of the present invention. Forming a protective film with excellent flammability, no elution of the cured film component into the Sn plating solution, small warpage after curing, and excellent insulation reliability under high temperature and high humidity. Can do. Moreover, since the thermosetting resin composition of the present invention is excellent in storage stability, a protective film can be formed with good workability.

  In the method for forming a protective film of a flexible wiring board according to the present invention, the wiring pattern is preferably subjected to Sn plating, and in the second step, the printed thermosetting resin composition is used. It is preferable to form a protective film by heating at 80 to 160 ° C.

  Further, the flexible wiring board of the present invention includes a base material, a wiring pattern provided on the base material, and a protective film provided on the wiring pattern and made of a cured product of the thermosetting resin composition of the present invention. With.

  According to the present invention, even if it does not contain a halogen-based flame retardant, it has sufficient flame retardancy, elution of the cured film component into the Sn plating solution is not observed, warpage after curing is small, high temperature It is possible to provide a thermosetting resin composition capable of forming a film having sufficient insulation reliability under high humidity by a printing method, a method for forming a protective film of a flexible wiring board using the composition, and a flexible wiring board.

[First Embodiment; Thermosetting Resin Composition]
The thermosetting resin composition according to the first embodiment of the present invention includes (A) a resin having an acid anhydride group and / or a carboxyl group in the molecule, (B) an epoxy resin, and (C) an inorganic filler. And (D) a phosphazene compound and (E) a rust inhibitor.

  (A) As a resin having an acid anhydride group and / or a carboxyl group in the molecule (hereinafter sometimes referred to as “(A) resin”), for example, an epoxy resin having a butadiene structure or a silicone structure, a phenol resin, Acids in the main chain and / or side chain of resins such as acrylic resin, polyurethane, polybutadiene, water-added polybutadiene, polyester, polycarbonate, polyether, polysulfone, polytetrafluororesin, polysilicone, melamine resin, polyamide, polyamideimide, and polyimide What introduce | transduced the anhydride group and / or the carboxyl group is mentioned as a preferable thing. Among these, an acid anhydride group and / or a main chain and / or a side chain of a resin such as an epoxy resin having a butadiene structure or a silicone structure, polyurethane, polybutadiene, water-added polybutadiene, polycarbonate, polyamide, polyamideimide, or polyimide. What introduced the carboxyl group is more preferable. These resins can be used alone or in combination of two or more.

  Moreover, what introduce | transduced the acid anhydride group and / or the carboxyl group into the terminal and / or side chain of said resin can be used as (A) resin. By using such a resin, the reactivity with the epoxy resin which is the component (B) described later is increased, so that the sticking property (adhesiveness) can be improved. The resin having an acid anhydride group and / or a carboxyl group may be used in combination with a resin having no acid anhydride group and a carboxyl group.

  A resin having a carboxyl group introduced therein can be obtained, for example, by blending a compound having a carboxyl group capable of radical polymerization, condensation polymerization or ion polymerization in the process of synthesizing the resin.

［一般式（２）中、Ｚ^１は３価の有機基を示し、Ｗは水酸基、イソシアネート基、カルボキシル基、エポキシ基又はグリシジル基を示す。］

［一般式（３）中、Ｚ^２は４価の有機基を示す。］ The resin having an acid anhydride group introduced is, for example, an epoxy residue, an isocyanate residue, a hydroxyl group, a carboxyl group, or the like of the resin, and the following general formula (2) and / or the following general formula (3). It can be obtained by reacting the compound represented.

[In General Formula (2), Z ¹ represents a trivalent organic group, and W represents a hydroxyl group, an isocyanate group, a carboxyl group, an epoxy group, or a glycidyl group. ]

[In General Formula (3), Z ² represents a tetravalent organic group. ]

  The resin (A) used in the present embodiment preferably has flexibility and a low elastic modulus so as to be compatible with a flexible substrate. (A) As a method for making the resin flexible and low elastic modulus, for example, introduction of a component capable of improving flexibility into the main chain of the resin can be mentioned. Examples of the component include a polybutadiene skeleton, a silicone resin skeleton, and a polycarbonate skeleton. Two or more of these skeletons may be introduced.

  Moreover, the heat resistance of a cured film, an electrical property, moisture resistance, solvent resistance, and chemical resistance can be improved by introduce | transducing the component which can improve heat resistance in the principal chain of resin. As the component, for example, polyimide, polyamideimide, polyamide, or a skeleton thereof is preferable. Among these, a polycarbonate skeleton and an imide skeleton are preferable from the viewpoint of flexibility, low elastic modulus, and high heat resistance.

  The resin (A) used in this embodiment reacts, for example, a 1,6-hexanediol-based polycarbonate diol and the like with a compound having a carboxyl group, a compound having an acid anhydride, and / or a compound having an isocyanate group. Can be obtained.

  The (A) resin is selected from, for example, component (a-1): a trivalent polycarboxylic acid having an acid anhydride group and a derivative thereof, and a tetravalent polycarboxylic acid having an acid anhydride group. It can be obtained by reacting at least one kind of compound with (a-2) component: isocyanate compound or amine compound.

［一般式（４）及び（５）中、Ｒ'は水素、炭素数１〜１０のアルキル基又
はフェニル基を示し、Ｙ^１は−ＣＨ_２−、−ＣＯ−、−ＳＯ_２−、又は−Ｏ−を示す。］ Among the components (a-1), examples of the trivalent polycarboxylic acid having an acid anhydride group and derivatives thereof include compounds represented by the following general formulas (4) and (5).

[In General Formulas (4) and (5), R ′ represents hydrogen, an alkyl group having 1 to 10 carbon atoms, or a phenyl group, and Y ¹ represents —CH ₂ —, —CO—, —SO ₂ —, or — O- is shown. ]

As the trivalent polycarboxylic acid having an acid anhydride group, trimellitic anhydride is more preferable from the viewpoints of heat resistance and cost.

［一般式（６）中、Ｙ^２は、下記式（７）：

で示される複数の基から選ばれる基である。］
Moreover, as a tetravalent polycarboxylic acid which has an acid anhydride group among (a-1) components, the tetracarboxylic dianhydride shown by following General formula (6) is mentioned, for example. These can be used alone or in combination of two or more.

[In General Formula (6), Y ² represents the following Formula (7):

A group selected from a plurality of groups represented by: ]

  In addition, as an acid component other than the above compounds, aliphatic dicarboxylic acids (succinic acid, glutaric acid, adipic acid, azelaic acid, suberic acid, sebacic acid, decanedioic acid, dodecanedioic acid, dimer acid, etc., if necessary ), Aromatic dicarboxylic acids (isophthalic acid, terephthalic acid, phthalic acid, naphthalenedicarboxylic acid, oxydibenzoic acid, etc.) can be used in combination. In this case, an amide bond is also formed in the molecular chain.

［一般式（８）中、複数個のＲは、それぞれ独立に炭素数１〜２０のアルキ
レン基、好ましくは炭素数１〜１８のアルキレン基を示し、Ｘは、２価の有機基、好ましくは炭素数１〜２０のアルキレン基又はアリーレン基、より好ましくは炭素数１〜１８のアルキレン基又はアリーレン基を示し、ｍ及びｎは、それぞれ独立に１〜３０、好ましくは１〜２０の整数を示し、ｎが２以上の場合、複数個のＸは同一であっても異なっていてもよい。］ Examples of the isocyanate compound used as the component (a-2) include diisocyanates represented by the following general formula (8) (hereinafter sometimes referred to as compound (a-2-1)).

[In the general formula (8), a plurality of R's each independently represents an alkylene group having 1 to 20 carbon atoms, preferably an alkylene group having 1 to 18 carbon atoms, and X represents a divalent organic group, preferably An alkylene group or an arylene group having 1 to 20 carbon atoms, more preferably an alkylene group or an arylene group having 1 to 18 carbon atoms, and m and n each independently represent an integer of 1 to 30, preferably 1 to 20. , N is 2 or more, the plurality of X may be the same or different. ]

［一般式（９）中、複数個のＲは、それぞれ独立に炭素数１〜２０のアルキレン基、好ましくは炭素数１〜１８のアルキレン基であり、ｍは１〜３０、好ましくは１〜２０の整数である。］

［一般式（１０）中、Ｘは、二価の有機基である。］ The compound (a-2-1) represented by the general formula (8) is obtained by reacting the carbonate diol represented by the following general formula (9) with the diisocyanate represented by the following general formula (10). Obtainable.

[In General Formula (9), a plurality of R's are each independently an alkylene group having 1 to 20 carbon atoms, preferably an alkylene group having 1 to 18 carbon atoms, and m is 1 to 30, preferably 1 to 20. Is an integer. ]

[In General Formula (10), X is a divalent organic group. ]

  As a bivalent organic group shown by X in the said General formula (10), C1-C20, Preferably a C1-C18 alkylene group or arylene group is mentioned, for example. Specific examples of the arylene group include an arylene group such as a phenylene group which is unsubstituted or substituted with a lower alkyl group having 1 to 5 carbon atoms such as a methyl group. Groups having two aromatic rings such as diphenylmethane-4,4′-diyl group and diphenylsulfone-4,4′-diyl group are also preferred.

  Examples of the carbonate diols represented by the general formula (9) include α, ω-poly (hexamethylene carbonate) diol, α, ω-poly (3-methyl-pentamethylene carbonate) diol, and the like. Examples of such products include trade names “PLACCEL CD-205, 205PL, 205HL, 210, 210PL, 210HL, 220, 220PL, 220HL” manufactured by Daicel Chemical Industries, Ltd. These can be used alone or in combination of two or more.

  Examples of the diisocyanates represented by the general formula (10) include diphenylmethane-2,4′-diisocyanate; 3,2′-, 3,3′-, 4,2′-, 4,3′-. 5,2'-, 5,3'-, 6,2'- or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate; 3,2'-, 3,3'-, 4,2 ' -, 4,3'-, 5,2'-, 5,3'-, 6,2'- or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate; 3,2'-, 3,3 '-, 4,2'-, 4,3'-, 5,2'-, 5,3'-, 6,2'- or 6,3'-dimethoxydiphenylmethane-2,4'-diisocyanate; diphenylmethane- 4,4′-diisocyanate; diphenylmethane-3,3′-diisocyanate; diphenylmethane-3,4′-diisocyanate; Benzophenone-4,4'-diisocyanate; diphenylsulfone-4,4'-diisocyanate; tolylene-2,4-diisocyanate; tolylene-2,6-diisocyanate; m-xylylene diisocyanate P-xylylene diisocyanate; naphthalene-2,6-diisocyanate; 4,4 ′-[2,2bis (4-phenoxyphenyl) propane] diisocyanate and the like. In these diisocyanates, it is preferable to use an aromatic polyisocyanate in which X in the general formula (10) has an aromatic ring. These can be used alone or in combination of two or more.

  Further, as the diisocyanates represented by the general formula (10), within the scope of the object of the present invention, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, Aliphatic or alicyclic isocyanates such as transcyclohexane-1,4-diisocyanate, hydrogenated m-xylylene diisocyanate, and lysine diisocyanate, or trifunctional or higher polyisocyanates can be used.

  The diisocyanates represented by the general formula (10) may be those stabilized with a blocking agent in order to avoid changes over time. Examples of the blocking agent include alcohol, phenol and oxime, but there is no particular limitation.

  The compounding ratio of the carbonate diols represented by the general formula (9) and the diisocyanates represented by the general formula (10) is converted into the ratio of the number of hydroxyl groups to the number of isocyanate groups, and isocyanate groups / hydroxyl groups = 1. It is preferable to make it 01 or more.

  The reaction of the carbonate diol represented by the general formula (9) and the diisocyanate represented by the general formula (10) can be carried out in the absence of a solvent or in the presence of an organic solvent. The reaction temperature is preferably 60 to 200 ° C, more preferably 80 to 180 ° C. The reaction time can be appropriately selected depending on the scale of the batch, the reaction conditions employed, and the like. For example, it can be 2 to 5 hours on a flask scale of 1 to 5 L (liter).

  The number average molecular weight of the compound (a-2-1) (isocyanate compound) obtained as described above is preferably 500 to 10,000, more preferably 1,000 to 9,500, It is especially preferable that it is 1,500-9,000. When the number average molecular weight is less than 500, the warping property tends to be deteriorated. When the number average molecular weight exceeds 10,000, the reactivity of the isocyanate compound is lowered, and it tends to be difficult to obtain a polyimide resin.

In the present invention, the number average molecular weight is a value measured by gel permeation chromatography (GPC) and converted using a standard polystyrene calibration curve. Moreover, the number average molecular weight and dispersion degree of this invention are defined as follows.
(A) Number average molecular weight (M _n ):
M _n = Σ (N _i M _i ) / N _i = ΣX _i M _i
[X _i = Mole fraction of molecules with molecular weight M _i = N _i / ΣN _i ]
(B) Weight average molecular weight:
M _w = Σ (N _i M _i ² ) / ΣN _i M _i = ΣW _i M _i
[W _i = Molecular weight M _i molecular weight fraction = N _i M _i / ΣN _i M _i ]
(C) Molecular weight distribution (dispersity):
Dispersity = M _w / M _n

  As the isocyanate compound of the component (a-2), a compound other than the compound (a-2-1) (hereinafter referred to as compound (a-2-2)) can also be used. The compound (a-2-2) is not particularly limited as long as it is an isocyanate compound other than the compound (a-2-1). For example, the diisocyanate represented by the general formula (9) is a trivalent or higher valent compound. And polyisocyanates. These can be used alone or in combination of two or more. The preferable range of the number average molecular weight of the isocyanate compound of the compound (a-2-2) is the same as that of the compound (a-2-1).

  In particular, from the viewpoint of heat resistance, it is preferable to use the compound (a-2-1) and the compound (a-2-2) in combination. In addition, when each of compound (a-2-1) or compound (a-2-2) is used alone, from the viewpoint of improvement in flexibility and warpage as a protective film for a flexible wiring board, the compound ( It is preferable to use a-2-1).

  As compound (a-2-2), it is preferable that 50-100 mass% of the total amount is aromatic polyisocyanate, and if balance, such as heat resistance, solubility, a mechanical characteristic, and a cost surface, is considered, it is 4 4,4'-diphenylmethane diisocyanate is particularly preferred.

  When the compound (a-2-1) and the compound (a-2-2) are used in combination, the equivalent ratio of compound (a-2-1) / compound (a-2-2) is 0.1 / 0.9. To 0.9 / 0.1, more preferably 0.2 / 0.8 to 0.8 / 0.2, and 0.3 / 0.7 to 0.7 / 0. 3 is particularly preferable. When the equivalence ratio is within this range, film properties such as good low warpage, adhesion and good heat resistance can be obtained.

  Among the components (a-2), examples of the amine compound include compounds obtained by converting the isocyanate group in the isocyanate compound of the component (a-2) to an amino group. Conversion of the isocyanato group to an amino group can be performed by a known method. The preferred range of the number average molecular weight of the amine compound is the same as that of the compound (b-1).

  In addition, the component (a-1) “one or more compounds selected from trivalent polycarboxylic acids having acid anhydride groups and derivatives thereof, and tetravalent polycarboxylic acids having acid anhydride groups” The blending ratio is such that the ratio of the total number of carboxyl groups and acid anhydride groups in component (a-1) to the total number of isocyanate groups in component (a-2) is 0.6 to 1.4. It is preferable that the ratio is 0.7 to 1.3, more preferably 0.8 to 1.2. When this ratio is less than 0.6 or exceeds 1.4, it tends to be difficult to increase the molecular weight of the resin containing polyimide bonds.

［一般式（１１）中、複数個のＲは、それぞれ独立に炭素数１〜２０のア
ルキレン基、好ましくは炭素数１〜１８のアルキレン基を示し、Ｘは、２価の有機基、好ましくは炭素数１〜２０のアルキレン基又はアリーレン基、より好ましくは炭素数１〜１８のアルキレン基又はアリーレン基を示し、ｍ及びｎは、それぞれ独立に１〜３０、好ましくは１〜２０の整数を示し、ｎが２以上の場合、ｎ個のＸは同一であっても異なっていてもよい。］ When the compound represented by the general formula (4) is used as the component (a-1) and the compound (b-1) represented by the general formula (8) is used as the component (a-2), the following general formula A polyamideimide resin having the structural unit represented by (11) can be obtained.

[In the general formula (11), a plurality of R's each independently represents an alkylene group having 1 to 20 carbon atoms, preferably an alkylene group having 1 to 18 carbon atoms, and X is a divalent organic group, preferably An alkylene group or an arylene group having 1 to 20 carbon atoms, more preferably an alkylene group or an arylene group having 1 to 18 carbon atoms, and m and n each independently represent an integer of 1 to 30, preferably 1 to 20. , N is 2 or more, n X may be the same or different. ]

［一般式（１２）中、複数個のＲは、それぞれ独立に炭素数１〜２０のア
ルキレン基、好ましくは炭素数１〜１８のアルキレン基を示し、Ｘは、２価の有機基、好ましくは炭素数１〜２０のアルキレン基又はアリーレン基、より好ましくは炭素数１〜１８のアルキレン基又はアリーレン基を示し、ｍ及びｎは、それぞれ独立に１〜３０、好ましくは１〜２０の整数を示し、ｎが２以上の場合、ｎ個のＸは同一であっても異なっていてもよく、Ｙ^１は、−ＣＨ_２−、−ＣＯ−、−ＳＯ_２−、又は−Ｏ−である。］ When the compound represented by the general formula (5) is used as the component (a-1) and the compound (b-1) represented by the general formula (8) is used as the component (a-2), the following general formula A polyamideimide resin having the structural unit represented by (12) can be obtained.

[In the general formula (12), a plurality of R each independently represents an alkylene group having 1 to 20 carbon atoms, preferably an alkylene group having 1 to 18 carbon atoms, and X represents a divalent organic group, preferably An alkylene group or an arylene group having 1 to 20 carbon atoms, more preferably an alkylene group or an arylene group having 1 to 18 carbon atoms, and m and n each independently represent an integer of 1 to 30, preferably 1 to 20. , N is 2 or more, n X may be the same or different, and Y ¹ is —CH ₂ —, —CO—, —SO ₂ —, or —O—. ]

［一般式（１３）中、複数個のＲは、それぞれ独立に炭素数１〜２０のア
ルキレン基、好ましくは炭素数１〜１８のアルキレン基を示し、Ｘは、２価の有機基、好ましくは炭素数１〜２０のアルキレン基又はアリーレン基、より好ましくは炭素数１〜１８のアルキレン基又はアリーレン基を示し、ｍ及びｎは、それぞれ独立に１〜３０、好ましくは１〜２０の整数を示し、ｎが２以上の場合、複数個のＸは同一であっても異なっていてもよく、Ｙ^２は、上記式（７）で示される複数の基から選ばれる基である。］ When the compound represented by the general formula (6) is used as the component (a-1) and the compound (b-1) represented by the general formula (8) is used as the component (a-2), the following general formula A polyimide resin having the structural unit represented by (13) can be obtained.

[In the general formula (13), a plurality of R each independently represents an alkylene group having 1 to 20 carbon atoms, preferably an alkylene group having 1 to 18 carbon atoms, and X represents a divalent organic group, preferably An alkylene group or an arylene group having 1 to 20 carbon atoms, more preferably an alkylene group or an arylene group having 1 to 18 carbon atoms, and m and n each independently represent an integer of 1 to 30, preferably 1 to 20. , N is 2 or more, a plurality of X may be the same or different, and Y ² is a group selected from a plurality of groups represented by the above formula (7). ]

  Component (a-1): one or more compounds selected from trivalent polycarboxylic acids having acid anhydride groups and derivatives thereof, and tetravalent polycarboxylic acids having acid anhydride groups; and (a-2) ) Component: The reaction with an isocyanate compound or an amine compound is carried out by heat condensation in the presence of an organic solvent, preferably a non-nitrogen-containing polar solvent, while removing the generated carbon dioxide gas from the reaction system. Can do.

  Examples of the non-nitrogen-containing polar solvent include ether solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, and triethylene glycol diethyl ether; sulfur-containing solvents such as dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, and sulfolane; Examples thereof include ester solvents such as γ-butyrolactone and cellosolve acetate; ketone solvents such as cyclohexanone and methyl ethyl ketone; aromatic hydrocarbon solvents such as toluene and xylene. These can be used alone or in combination of two or more.

  As the solvent, it is preferable to select and use a solvent that dissolves the resin to be produced. (A) After the synthesis of the resin, it is preferable to use a solvent that is suitable as a solvent for the thermosetting resin composition as it is. From the viewpoint of high volatility, imparting low temperature curability, and efficient reaction in a homogeneous system, it is preferable to use γ-butyrolactone.

It is preferable that the usage-amount of a solvent shall be 0.8 to 5.0 times (mass ratio) of (A) resin to produce | generate. If this mass ratio is less than 0.8 times, the viscosity at the time of synthesis tends to be too high and synthesis tends to be difficult due to the inability to stir, and if it exceeds 5.0 times, the reaction rate tends to decrease. is there.
The reaction temperature is preferably 80 to 210 ° C, more preferably 100 to 190 ° C, and particularly preferably 120 to 180 ° C. If it is less than 80 ° C., the reaction time becomes too long, and if it exceeds 210 ° C., a three-dimensional reaction occurs during the reaction and gelation tends to occur. The reaction time can be appropriately selected depending on the scale of the batch and the reaction conditions employed.

  The reaction between the component (a-1) and the component (a-2) is carried out by using a metal or a semimetal compound such as a tertiary amine, an alkali metal, an alkaline earth metal, tin, zinc, titanium, or cobalt as necessary. Or the like in the presence of a catalyst.

  The polyamide resin, polyamideimide resin and polyimide resin obtained as described above have an isocyanate residue, and the compound represented by the general formula (2) and / or the general formula (3) in the isocyanate residue. By reacting, a resin having an acid anhydride group can be obtained. In this case, the reactivity with the epoxy resin which is a component (B) described later is improved, and the adhesiveness to a flexible substrate such as a polyimide substrate can be reduced.

  In addition to the compound represented by the general formula (2) or the general formula (3), blocking agents such as alcohols, lactams, and oximes can be used in combination so as not to impair the effects of the present invention. .

As the compound represented by the general formula (3), a tetracarboxylic acid dihydrate (pyromellitic anhydride) represented by the following formula (14) is preferable.

  The amount of pyromellitic anhydride added is preferably in the range of 10 to 20% by mass based on the total amount of isocyanate. When the added amount of pyromellitic anhydride exceeds 20% by mass, viscosity control becomes difficult and workability tends to decrease. On the other hand, if the amount of pyromellitic anhydride added is less than 10% by mass, sticking to the polyimide film tends to occur after curing.

［一般式（１５）中、Ｒ^１は、水素原子、炭素数１〜３のアルキル基を示
す。］

［一般式（１６）中、複数個のＲは、それぞれ独立に炭素数１〜２０のア
ルキレン基、好ましくは炭素数１〜１８のアルキレン基を示し、Ｘは、２価の有機基、好ましくは炭素数１〜２０のアルキレン基又はアリーレン基、より好ましくは炭素数１〜１８のアルキレン基又はアリーレン基を示し、ｍ及びｎは、それぞれ独立に１〜３０、好ましくは１〜２０の整数を示し、ｎが２以上の場合、ｎ個のＸは同一であっても異なっていてもよい。］ Specific examples of the resin (A) other than the above-described resins include, for example, the above general formula (9), the above general formula (10), and the following general formula (15), and synthesize the above (b-1). Examples thereof include resins obtained by reacting under the same conditions as at the time. The resin thus obtained is a urethane resin having a repeating structure represented by the following general formula (16) and a carboxyl group, and the reactivity with the epoxy resin as the component (B) described later is improved. And the sticking property to a polyimide base material can be reduced.

[In General Formula (15), R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ]

[In General Formula (16), a plurality of R's each independently represents an alkylene group having 1 to 20 carbon atoms, preferably an alkylene group having 1 to 18 carbon atoms, and X represents a divalent organic group, preferably An alkylene group or an arylene group having 1 to 20 carbon atoms, more preferably an alkylene group or an arylene group having 1 to 18 carbon atoms, and m and n each independently represent an integer of 1 to 30, preferably 1 to 20. , N is 2 or more, n X may be the same or different. ]

  The number average molecular weight of the resin thus obtained is preferably 15,000 to 50,000, more preferably 20,000 to 45,000, and 25,000 to 40,000. It is particularly preferred. Further, the dispersity at that time is preferably 1.5 to 3.5, and more preferably 2.0 to 3.0. If the number average molecular weight is less than 15,000, sticking between the cured film and the polyimide film tends to occur, and if the number average molecular weight exceeds 50,000, it is difficult to dissolve in a non-nitrogen-containing polar solvent. This is not preferable because it tends to be insolubilized during the synthesis, and the workability such as mixing with an inorganic filler (inorganic filler) and / or organic filler (organic filler) and screen printing may be deteriorated.

  In addition, in the resin having the structural unit represented by the general formula (11), (12), (13) or (14), the side chain of the molecular chain usually does not have an acid anhydride group or a carboxyl group. Therefore, a structure in which an acid anhydride group and / or a carboxyl group is provided at one or both ends of the molecular chain is preferable.

  Various epoxy resins can be used for the epoxy resin which is (B) component, in order to improve thermosetting. Examples of the epoxy resin include bisphenol A type epoxy resin (trade name “Epicoat 828” manufactured by Yuka Shell Epoxy Co., Ltd.), bisphenol F type epoxy resin (trade name “YDF-170” manufactured by Toto Kasei Co., Ltd.), and the like. ), Phenol novolac type epoxy resin (trade name “Epicoat 152, 154” manufactured by Yuka Shell Epoxy Co., Ltd.); product name “EPPN-201” manufactured by Nippon Kayaku Co., Ltd .; 438 ”, etc.), o-cresol novolac type epoxy resin (trade name“ EOCN-125S, 103S, 104S ”, etc., manufactured by Nippon Kayaku Co., Ltd.), etc. “Epon1031S”; trade name “Araldite 01” manufactured by Ciba Specialty Chemicals Co., Ltd. 3 "; trade names" Denacol EX-611, EX-614, EX-614B, EX-622, EX-512, EX-521, EX-421, EX-411, EX-321 "manufactured by Nagase Kasei Co., Ltd. ), Amine type epoxy resin (trade name “Epicoat 604” manufactured by Yuka Shell Epoxy Co., Ltd .; product name “YH434” manufactured by Tohto Kasei Co., Ltd .; trade name “TETRAD-X” manufactured by Mitsubishi Gas Chemical Co., Ltd. ” "TERRAD-C"; Nippon Kayaku Co., Ltd. trade name "GAN"; Sumitomo Chemical Co., Ltd. trade name "ELM-120", etc.), heterocycle-containing epoxy resin (Ciba Specialty Chemicals Co., Ltd.) Name “Araldite PT810”, etc.), alicyclic epoxy resins (“ERL4234, 4299, 4221, 4206”, etc. manufactured by UCC), etc. That. These can be used alone or in combination of two or more. Among these epoxy resins, amine-type epoxy resins, particularly amine-type epoxy resins having 3 or more epoxy groups in one molecule are particularly preferable in terms of improving solvent resistance, chemical resistance and moisture resistance.

  In the thermosetting resin composition according to the present embodiment, an epoxy compound having only one epoxy group in one molecule can be blended as an epoxy resin. Such an epoxy compound is preferably used in the range of 0 to 20% by mass with respect to the total amount of the “resin having an acid anhydride group and / or carboxyl group” as the component (A). Examples of such an epoxy compound include n-butyl glycidyl ether, phenyl glycidyl ether, dibromophenyl glycidyl ether, and dibromocresyl glycidyl ether. In addition, alicyclic epoxy compounds such as 3,4-epoxycyclohexyl and methyl (3,4-epoxycyclohexane) carboxylate can be used.

  The content of the (B) epoxy resin in the thermosetting resin composition according to this embodiment is preferably based on 100 parts by mass of the “resin having an acid anhydride group and / or carboxyl group” used as the component (A). Is 1 to 50 parts by mass, more preferably 2 to 45 parts by mass, and even more preferably 3 to 40 parts by mass. If the compounding amount of the epoxy resin is less than 1 part by mass, the curability, solvent resistance, chemical resistance, and moisture resistance of the resin composition tend to decrease, and if it exceeds 50 parts by mass, the heat resistance and viscosity stability are increased. Tend to decrease.

  About the compounding method of an epoxy resin, even if it adds after melt | dissolving an epoxy resin in the same organic solvent as the organic solvent which melt | dissolves "resin which has an acid anhydride group and / or a carboxyl group" used as (A) component Alternatively, an epoxy resin may be added directly.

（一般式（１７）中、複数のＸは各々独立に一価の基を示す。） As the (C) phosphazene compound blended in the thermosetting resin composition of the present invention, a phosphazene compound having a cyclophosphazene structure represented by the following general formula (17) is preferable.

(In the general formula (17), a plurality of X's each independently represents a monovalent group.)

  Examples of X include an alkoxy group, a halogen, an amino group, a fluoroalkoxy group, a phenoxy group that may have a substituent on the benzene ring, and the like, and in particular, it may have a substituent on the benzene ring. A phenoxy group is preferred. Examples of the substituent include a nitrile group and a phenolic hydroxyl group.

  As such a phosphazene compound, for example, commercially available products such as “FP-100”, “FP-300” (trade name, manufactured by Fushimi Pharmaceutical Co., Ltd.) and “SPB-100” (trade name, manufactured by Otsuka Chemical Co., Ltd.) are used. Can do.

  The content of the (C) phosphazene compound in the thermosetting resin composition according to this embodiment is preferably 20 parts by mass to 80 parts by mass with respect to 100 parts by mass of the resin (A), and 20 parts by mass to 40 parts by mass. Mass parts are more preferred, and 20 to 30 parts by mass are even more preferred. When the content of the phosphazene compound is less than 20 parts by mass, the flame retardancy tends to decrease, and when it exceeds 40 parts by mass, the adhesiveness of the cured product increases and the insulation reliability under high temperature and high humidity decreases. Tend to.

Examples of the (D) inorganic filler blended in the thermosetting resin composition according to the present embodiment include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), titania (TiO ₂ ), and tantalum oxide (Ta). ₂ O ₅ ), zirconia (ZrO ₂ ), silicon nitride (Si ₃ N ₄ ), barium titanate (BaO · TiO ₂ ), barium carbonate (BaCO ₃ ), lead titanate (PbO · TiO ₂ ), zircon titanate lead (PZT), lead lanthanum zirconate titanate (PLZT), gallium oxide _{(Ga 2 O} 3), spinel _{(MgO · Al 2 O 3)} , mullite _{(3Al 2 O 3 · 2SiO 2} ), cordierite ( _{2MgO · 2Al 2 O 3 / 5SiO} 2), talc _{(3MgO · 4SiO 2 · H 2} O), aluminum titanate _(TiO 2 _-Al 2 _{O 3} ), Yttria-containing zirconia _{(Y 2 O 3 -ZrO 2)} , barium silicate (BaO · 8SiO _2), boron nitride (BN), calcium carbonate (CaCO _3), hydrotalcite, calcium sulfate (CaSO _4), oxide Examples thereof include zinc (ZnO), magnesium titanate (MgO.TiO ₂ ), barium sulfate (BaSO ₄ ), organic bentonite, and carbon (C). These can be used alone or in combination of two or more.

  (D) The inorganic filler preferably contains silica that is insoluble in the Sn plating solution and has high dispersibility in γ-butyrolactone, and SO-25R (trade name, manufactured by Admatechs) is commercially available. is there.

  The content of (D) inorganic filler in the thermosetting resin composition according to the present embodiment is preferably 10 to 300 parts by mass, and 30 to 250 parts by mass with respect to 100 parts by mass of (A) resin. It is more preferable to set it to 50 to 200 parts by mass. When the content of component (D) is less than 10 parts by mass, the viscosity and thixotropy coefficient of the resin composition are lowered, the stringing of the resin composition is increased, and the flow of the resin composition after printing is increased. The film thickness also tends to be reduced, and the electrical characteristics tend to be inferior. On the other hand, when the content of the component (D) exceeds 300 parts by mass, the viscosity and thixotropy coefficient of the resin composition increase, the transferability of the resin composition to the substrate decreases, and voids in the printed film and There is a tendency for pinholes to increase.

  As the inorganic filler (D), those having an average particle size of 50 μm or less and a maximum particle size of 100 μm or less are preferably used. When the average particle diameter exceeds 50 μm, it becomes difficult to obtain a paste having a thixotropic coefficient of 1.1 or more, which will be described later, and when the maximum particle diameter exceeds 100 μm, the appearance and adhesion of the coating film tend to be insufficient. . The average particle size is more preferably 30 μm or less, further preferably 10 μm or less, particularly preferably 3 μm or less, and the maximum particle size is more preferably 80 μm or less, still more preferably 60 μm or less, and particularly preferably 40 μm or less.

  The thermosetting resin composition according to the present embodiment can further contain an organic filler (organic filler). As the organic filler, fine particles of a heat resistant resin having an amide bond, an imide bond, an ester bond or an ether bond are preferable. As such a heat-resistant resin, from the viewpoint of heat resistance and mechanical properties, polyimide resin or a precursor thereof, polyamideimide resin or a precursor thereof, or polyamide resin fine particles are preferably used.

  The heat resistant resin as the organic filler can be produced as follows. First, a polyimide resin can be obtained by reacting (i) an aromatic tetracarboxylic dianhydride and (ii) an aromatic diamine compound.

  (I) As aromatic tetracarboxylic dianhydride, for example, pyromellitic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-bis Phenyltetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 2,2-bis ( 3,4-dicarboxyphenyl) propane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3 , 4-Dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis (3,4-di Carboxyphenyl Ether dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, 3,4,3 ′, 4′-benzophenone tetracarboxylic dianhydride, 2,3,2 ′, 3′- Benzophenone tetracarboxylic dianhydride, 2,3,3 ′, 4′-benzophenone tetracarboxylic dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, 2,3,6,7- Naphthalenetetracarboxylic dianhydride, 1,2,4,5-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,6-dichloronaphthalene-1, 4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-terolachlornaphthalene-1, 4,5,8-tetracar Acid dianhydride, phenanthrene-1,8,9,10-tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) dimethylsilane dianhydride, bis (3,4-dicarboxyphenyl) methyl Phenylsilane dianhydride, bis (3,4-dicarboxyphenyl) diphenylsilane dianhydride, 1,4-bis (3,4-dicarboxyphenyldimethylsilyl) benzene dianhydride, 1,3-bis (3 , 4-Dicarboxyphenyl) -1,1,3,3-tetramethyldicyclohexane dianhydride, p-phenylenebis (trimellitic acid monoester anhydride), 2,2-bis (3,4-di Carboxyphenyl) hexafluoropropane dianhydride, 2,2-bis {4- (3,4-dicarboxyphenoxy) phenyl} hexafluoropropane dianhydride, 2,2-bis {4- (3,4-dicarboxyphenoxy) phenyl} propane dianhydride, 4,4-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 1,4-bis ( 2-hydroxyhexafluoroisopropyl) benzene bis (trimellitate anhydride), 1,3-bis (2-hydroxyhexafluoroisopropyl) benzene bis (trimellitate anhydride), 1,2- (ethylene) bis (trimellitate anhydride), 1,3- (trimethylene) bis (trimellitic anhydride), 1,4- (tetramethylene) bis (trimellitic anhydride), 1,5- (pentamethylene) bis (trimellitic anhydride), 1,6- (hexa Methylene) bis (trimellitic anhydride), 1,7- (heptamethylene) bis (trimellitate anhydrous) ), 1,8- (octamethylene) bis (trimellitic anhydride), 1,9- (nonamethylene) bis (trimellitic anhydride), 1,10- (decamethylene) bis (trimellitic anhydride), 1,12- ( Dodecamemethylene) bis (trimellitate anhydride), 1,16- (hexadecamethylene) bis (trimellitate anhydride), 1,18- (octadecamethylene) bis (trimellitate anhydride) and the like. These can be used individually by 1 type or in mixture of 2 or more types.

  In addition to the above (i) aromatic tetracarboxylic dianhydride, depending on the purpose, a tetracarboxylic dianhydride other than the aromatic tetracarboxylic dianhydride may be added in an amount of 50 mol% of the aromatic tetracarboxylic dianhydride. Can be used within a range not exceeding. Examples of such tetracarboxylic dianhydrides include ethylene tetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic Acid dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, decahydronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 4,8-dimethyl-1,2 , 3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrrolidine-2, 3,4,5-tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, bis {exobicyclo [2,2,1] heptane-2,3-dicarboxylic anhydride Thing} sulfone, bishi Rho- (2,2,2) -oct (7) -ene-2,3,5,6-tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3 -Cyclohexane-1,2-dicarboxylic anhydride, tetrahydrofuran-2,3,4,5-tetracarboxylic dianhydride and the like.

  (Ii) As an aromatic diamine compound, for example, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenyldifluoromethane, 4,4′-diaminodiphenyldifluoromethane, 3,3′- Diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl ketone, 3,4'-diaminodiphenyl ketone, 4 , 4 ' Diaminodiphenyl ketone, 2,2-bis (3-aminophenyl) propane, 2,2-bis (3,4'-diaminophenyl) propane, 2,2-bis (4-aminophenyl) propane, 2,2- Bis (3-aminophenyl) hexafluoropropane, 2,2-bis (3,4'-diaminophenyl) hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 1,3-bis ( 3-aminophenyl) benzene, 1,4-bis (4-aminophenyl) benzene, 3,3 ′-[1,4-phenylenebis (1-methylethylidene)] bisaniline, 3,4 ′-[1,4 -Phenylenebis (1-methylethylidene)] bisaniline, 4,4 '-[1,4-phenylenebis (1-methylethylidene)] bisaniline, 2,2 Bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] hexafluoro Propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, Examples include bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, and the like. These can be used alone or in combination of two or more.

  In addition to the above (ii) aromatic diamine compound, a diamine compound other than the aromatic diamine compound can be used depending on the purpose within a range not exceeding 50 mol% of the aromatic diamine compound. Examples of such diamine compounds include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diamino. Heptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,3-bis (3-aminopropyl) tetramethyldisiloxane, 1,3-bis (3-aminopropyl) tetramethylpolysiloxane and the like.

  The (i) aromatic tetracarboxylic dianhydride and the (ii) aromatic diamine compound are preferably reacted in an approximately equimolar amount.

  Reaction of (i) aromatic tetracarboxylic dianhydride and (ii) aromatic diamine compound can be performed in an organic solvent. Examples of the organic solvent include N-methyl-2-pyrrolidone, dimethylacetamide, dimethylformamide, 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1H) -pyrimidinone, 1,3-dimethyl-2. -Nitrogen-containing compounds such as imidazolidinone; sulfur compounds such as sulfolane and dimethyl sulfoxide; γ-butyrolactone, γ-valerolactone, γ-caprolactone, γ-heptalactone, α-acetyl-γ-butyrolactone, ε-caprolactone, etc. Lactones; dioxane, 1,2-dimethoxyethane, diethylene glycol dimethyl (or diethyl, dipropyl, dibutyl) ether, triethylene glycol (or diethyl, dipropyl, dibutyl) ether, tetraethylene glycol dimethyl (or diethyl, dipropyl, dibutyl) E) ethers such as ether; ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, acetophenone; butanol, octyl alcohol, ethylene glycol, glycerin, diethylene glycol monomethyl (or monoethyl) ether, triethylene glycol monomethyl (or monoethyl) ether, Alcohols such as tetraethylene glycol monomethyl (or monoethyl) ether; phenols such as phenol, cresol, xylenol; esters such as ethyl acetate, butyl acetate, ethyl cellosolve acetate, butyl cellosolve acetate; toluene, xylene, diethylbenzene, cyclohexane, etc. Hydrocarbons: Halogenated charcoal such as trichloroethane, tetotachloroethane, monochlorobenzene Hydrogen fluorides and the like are used. These organic solvents are used alone or in combination. In consideration of solubility, low hygroscopicity, low temperature curability, environmental safety, etc., it is preferable to use lactones, ethers, ketones and the like.

  The reaction temperature is 80 ° C. or lower, preferably 0 to 50 ° C. As the reaction proceeds, the reaction solution gradually thickens. In this case, polyamic acid which is a precursor of the polyimide resin is generated. This polyamic acid may be partially imidized, and this is also included in the polyimide resin precursor.

  The polyimide resin is obtained by dehydrating and ring-closing the reactant (polyamide acid). Dehydration ring closure can be performed by a method of heat treatment at 120 ° C. to 250 ° C. (thermal imidization) or a method of using a dehydrating agent (chemical imidization). In the case of the heat treatment at 120 ° C. to 250 ° C., it is preferable to carry out while removing water generated by the dehydration reaction from the system. At this time, water may be removed azeotropically using benzene, toluene, xylene or the like.

  In the method of performing dehydration and ring closure using a dehydrating agent, it is preferable to use an acid anhydride such as acetic anhydride, propionic anhydride or benzoic acid, a carbodiimide compound such as dicyclohexylcarbodiimide, or the like as the dehydrating agent. At this time, if necessary, a dehydration catalyst such as pyridine, isoquinoline, trimethylamine, or aminopyridineimidazole may be used. The dehydrating agent or the dehydrating catalyst is preferably used in an amount of 1 to 8 moles per mole of aromatic tetracarboxylic dianhydride.

  Polyamideimide resin or a precursor thereof may be trimellitic anhydride or trimellitic anhydride derivative (trimellitic anhydride anhydride) instead of aromatic tetracarboxylic dianhydride in the production of the polyimide resin or precursor thereof. Trivalent tricarboxylic acid anhydrides or derivatives thereof such as chlorides of the products. Moreover, it can also manufacture using the diisocyanate compound corresponding to the diamine compound in which residues other than an amino group replace with an aromatic diamine compound and another diamine compound. Diisocyanate compounds that can be used include those obtained by reacting the above aromatic diamine compounds or other diamine compounds with phosgene or thionyl chloride.

Polyamide resin is obtained by reacting aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and phthalic acid, derivatives of these dichlorides and acid anhydrides, and the above aromatic diamine compounds or other diamine compounds. Can be manufactured.
Examples of the heat resistant resin having an ester bond include a polyester resin. Examples of the polyester resin include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and phthalic acid, derivatives of these dichlorides and acid anhydrides, 1,4-dihydroxybenzene, bisphenol F, bisphenol A, 4,4. Examples thereof include those obtained by reacting with an aromatic diol compound such as' -dihydroxybiphenyl.

  As the polyamideimide resin, a polyamideimide resin obtained by reacting an aromatic tetracarboxylic dianhydride and an aromatic diamine compound containing isophthalic acid dihydrazide as an essential component is preferably used. What was mentioned above is used as an aromatic tetracarboxylic dianhydride and an aromatic diamine compound. The molar ratio of isophthalic acid dihydrazide in the aromatic diamine compound is preferably 1 to 100 mol%. If it is less than 1 mol%, the solubility resistance to the modified polyamideimide resin tends to decrease, and if the content of isophthalic acid dihydrazide is large, the moisture resistance of the layer formed by the thermosetting resin composition of the present invention decreases. Therefore, 10 to 80 mol% is more preferable, and 20 to 70 mol% is particularly preferably used. This polyamide-imide resin can be obtained in the same manner as the synthesis of the polyimide resin described above, with respect to the blending ratio of the aromatic tetracarboxylic dianhydride and the aromatic diamine compound, the organic solvent used, the synthesis method, and the like.

  The polyamide-imide resin obtained by reacting trimellitic anhydride and, if necessary, dicarboxylic acid and polyisocyanate is likely to become insoluble in organic solvents by heating. It can also be used. About the manufacturing method of this polyamideimide resin, it can manufacture similarly to the manufacturing method of an above described polyamideimide resin.

  Examples of the fine particle forming method include a non-aqueous dispersion polymerization method (Japanese Patent Publication No. 60-48531, Japanese Patent Laid-Open No. 59-230018), and a precipitation polymerization method (Japanese Patent Laid-Open No. 59-108030, Japanese Patent Laid-Open No. 60). No. -22425), a method of mechanically pulverizing powder modified from a resin solution, a method of finely pulverizing a resin solution while adding the resin solution to a poor catalyst, a method of obtaining fine particles by drying a spray solution of a resin solution, a detergent Or the method etc. which precipitate resin which has the temperature dependence of solubility with respect to a solvent in a resin solution are mentioned.

  As a method of dispersing the above-mentioned inorganic filler and organic filler in the thermosetting resin composition according to the present embodiment, roll kneading, mixer mixing, etc., which are usually performed in the paint field, are applied, and sufficient dispersion Any method can be used.

  (E) Rust preventive means a material having an effect of suppressing metal corrosion, for example, has an action of inactivating or removing heavy metal ions having an action of catalytically promoting oxidative deterioration of a resin. (Heavy metal deactivator or heavy metal remover) and the like. In terms of structure, those containing nitrogen atoms are preferred. Specific examples of preferred ones include triazole compounds such as hydrazide compounds, aminotriazole compounds, and benzotriazole compounds, triazine compounds, salicylideneamine compounds, and the like. Antirust agent. Among these, hydrazide compounds and triazole compounds, which are highly effective in the present invention, are preferable because of their high effects. As a rust preventive agent, for example, trade name “Irganox MD-1024” (N, N′-bis [3- (3,5-di-t-butyl-4-hydroxy) manufactured by Ciba Specialty Chemicals Co., Ltd. Phenyl) propionyl] hydrazine), trade name “CDA-1” (triazole compound), “CDA-6” (hydrazide compound) manufactured by ADEKA Corporation, trade name “Disnet DB” manufactured by Sankyo Kasei Co., Ltd. Commercial products such as (triazine compounds) can be suitably used. These rust inhibitors may be used alone or in combination of two or more.

  In the thermosetting resin composition according to this embodiment, the content of the (E) rust inhibitor is 5 to 25 with respect to 100 parts by mass of the resin (A) from the viewpoint of insulation reliability under high temperature and high humidity. It is preferable to set it as a mass part, It is more preferable to set it as 5-20 mass parts, It is still more preferable to set it as 5-15 mass parts.

  The thermosetting resin composition according to the present embodiment can contain an organic solvent such as a non-nitrogen-based polar solvent. Examples of non-nitrogen-containing polar solvents include ether solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, and triethylene glycol diethyl ether; for example, sulfur-containing compounds such as dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, and sulfolane. Solvents such as ester solvents such as γ-butyrolactone, cellosolve acetate, butyl carbitol acetate and 2-butoxyethyl acetate; ketone solvents such as cyclohexanone and methyl ethyl ketone; aromatic hydrocarbons such as toluene and xylene System solvents, and the like. These can be used alone or in combination of two or more.

  Among the above organic solvents, γ-butyrolactone solvents are preferable from the viewpoints of printability and operability.

  An antifoaming agent and a leveling agent can be added to the thermosetting resin composition according to the present embodiment.

  As an antifoaming agent or a leveling agent, for example, “DISPARON 230” (trade name of Enomoto Kasei Kogyo Co., Ltd.) “KS-602A”, “KS-603”, “KS-608”, “FA600” (above, Trade name manufactured by Shin-Etsu Chemical Co., Ltd.), “BYK-A506”, “BYK-A525”, “BYK-A530”, “BYK-A500”, “BYK-A500”, “BYK-A501”, “BYK” -A515 "," BYK-A555 "," Byketol-OK "(trade name, manufactured by Big Chemie Japan)," ARUFON UP-1000 "(trade name, manufactured by Toa Gosei Co., Ltd.), etc. A commercial item can be used conveniently. These antifoaming agents or leveling agents may be used alone or in combination of two or more.

  The addition amount of the antifoaming agent and the leveling agent is 0.2% by mass to 5% by mass based on the total solid content of the resin composition from the viewpoint of achieving both defoaming property, film forming property, and shape retention. Preferably, 0.5% by mass to 2% by mass is more preferable.

  In the thermosetting resin composition according to this embodiment, in order to improve workability during coating and film properties before and after film formation, colorants such as phenol resins, dyes or pigments, heat stabilizers, and antioxidants Agents, flame retardants, and lubricants can also be added.

  In the thermosetting resin composition according to the present embodiment, the viscosity at 25 ° C. with a rotary viscometer is preferably 20 Pa · s to 80 Pa · s, and more preferably 30 Pa · s to 50 Pa · s. preferable. When the viscosity is less than 20 Pa · s, the flow of the resin composition after printing increases and the film thickness tends to be reduced. When the viscosity exceeds 80 Pa · s, the resin composition is transferred to the substrate. There is a tendency for voids and pinholes in the printed film to increase with decreasing properties.

  The viscosity of the resin composition was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., RE80U type) with a sample amount of 0.2 ml or 0.5 ml under the conditions of a rotation speed of 10 rpm and 25 ° C. Refers to the value.

  The thermosetting resin composition according to the present embodiment includes, for example, base materials such as an overcoat material for electronic parts, a liquid encapsulant, a varnish for enamel wire, an impregnating varnish for electrical insulation, a casting varnish, mica, and a glass cloth. It can also be used for electronic parts such as sheet varnishes, MCL laminate varnishes, friction material varnishes, interlayer insulating films, surface protective films, solder resist layers, etc. in the printed circuit board field. It is done. For example, after printing on the wiring pattern of a flexible wiring board, it can be used suitably for the use which makes it harden | cure and form a cured film and uses it as a protective film. In particular, it is suitable for forming a protective film on the surface of a flexible wiring board in which all of the wiring pattern portions are plated. An example of the plating layer is Sn.

[Second Embodiment; Method for Forming Protective Film of Flexible Wiring Board]
In the method for forming a protective film of a flexible wiring board according to the second embodiment of the present invention, the thermosetting resin composition according to the first embodiment is printed on the wiring pattern of the flexible wiring board provided with the wiring pattern. And a second step of forming a protective film by thermosetting the printed thermosetting resin composition.

  The method for forming a protective film on a flexible wiring board according to this embodiment is suitable for forming a protective film on the surface of a flexible wiring board in which all of the wiring patterns are plated, and the wiring pattern is subjected to Sn plating. In some cases, a particularly excellent effect is exhibited.

  Screen printing is suitable as the printing method in the first step. Moreover, the application | coating method of a dispenser and a spin coat head can also be utilized.

  In addition, the thermosetting conditions in the second step are preferably 80 to 160 ° C., more preferably 120 to 150 ° C. from the viewpoint of obtaining warpage and flexibility suitable as a protective film. However, the thermosetting conditions are not limited to these ranges, and for example, the curing can be performed in the range of 50 to 200 ° C., and further in the range of 50 to 170 ° C.

  In addition, the heating time in the second step is preferably 60 to 150 minutes and more preferably 80 to 120 minutes from the viewpoint of obtaining warpage and flexibility suitable as a protective film, but is not limited to this range. It can also be cured in the range of 1 to 1000 minutes, for example, 5 to 300 minutes, and further 10 to 150 minutes.

[Third Embodiment: Flexible Wiring Board]
The flexible wiring board according to the third embodiment of the present invention includes a base material, a wiring pattern provided on the base material, and a thermosetting resin composition according to the first embodiment provided on the wiring pattern. And a protective film made of a cured product.

  Examples of the substrate include a polyimide film and a polyimide film with an epoxy adhesive layer. The thickness of the substrate can be set to 65 μm to 400 μm.

  The wiring pattern is preferably plated. An example of the plating process is Sn.

  The formation of the protective film on the wiring pattern can be suitably performed by the method for forming the protective film of the flexible wiring board according to the second embodiment.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

<Synthesis of polymer resin>
(Synthesis Example 1)
In a 3 liter four-necked flask equipped with a stirrer, a condenser with an oil separator, a nitrogen inlet tube and a thermometer, 61.72 g of γ-butyrolactone, Plaxel CD-220 (manufactured by Daicel Chemical Industries, Ltd., 1,6- A product name of 74.64 g (0.37 mol) of hexanediol-based polycarbonate diol, 125.14 g (0.46 mol) of 4,4′-diphenylmethane diisocyanate, and 58.4 g (0.34 mol) of toluene diisocyanate are charged. The temperature was raised to 150 ° C. and the reaction was carried out at 150 ° C. for 4 hours.
Next, 88.4 g (0.46 mol) of trimellitic anhydride was added to the reaction product, and the mixture was reacted at 70 ° C. for 3 hours. Subsequently, 6.76 g (0.027 mol) of 4,4′-diphenylmethane diisocyanate and 0.0034 g (0.00002 mol) of toluene diisocyanate were added again and reacted at 120 ° C. for 1 hour and at 180 ° C. for 3 hours. After the reaction, 341.6 g of γ-butyrolactone was added and cooled, and 9.5 g (0.11 mol) of 2-butanone oxime (manufactured by Wako Pure Chemical Industries, Ltd.) was further added and reacted at 120 ° C. for 3 hours. Thus, a polycarbonate-modified polyamideimide resin having a number average molecular weight of 38,000 was obtained. The number average molecular weight of the resin was adjusted by collecting a small amount of the reaction solution for each reaction time and observing the rate of change in viscosity with a Gardner bubble viscometer. The obtained resin was diluted with γ-butyrolactone to obtain a polycarbonate-modified polyamideimide resin solution having a nonvolatile content of 50% by mass.

(Synthesis Example 2)
In a reaction vessel equipped with a stirrer, a thermometer, and a condenser, 628 g of PLACEL CD220 and 400 g of PCDL T-6001, 41 g of 2,2-dimethylolpropionic acid (manufactured by Nippon Kasei Co., Ltd.), and Desmodur-W 565 g (2.16 mol) and 1090 g of γ-butyrolactone were charged, all raw materials were dissolved at 150 ° C., and reacted for 4 hours to produce a polyisocyanate having a urethane group.
Next, the temperature of the reaction solution was lowered to 80 ° C., and 183 g (0.11 mol) of polybutadiene having 1,2-repeating units as polymer polyol (G-1000, manufactured by Nippon Soda) and 656 g of γ-butyrolactone were added by a dropping funnel. Were added dropwise over 30 minutes. After completion of dropping, the reaction was carried out at 140 ° C. for 2 hours.
The temperature of the reaction solution was lowered to 90 ° C., and 122 g of 2,2-dimethylolpropionic acid and 194 g of γ-butyrolactone were added dropwise using a dropping funnel over 30 minutes. After reacting at 110 ° C. for 6.5 hours, 20 g of 2-butanone oxime was added to terminate the reaction, thereby obtaining a polycarbonate-modified polyurethane resin solution having a carboxyl group having a number average molecular weight of 10800 and a dispersity of 5.10. .

<Preparation of thermosetting resin composition>
Example 1
In a γ-butyrolactone solution, 200 parts by mass of the polycarbonate-modified polyamideimide resin solution obtained in Synthesis Example 1 (100 parts by mass of resin) and 100 parts by mass of silica (trade name: SO-25R manufactured by Admatechs Inc.) were previously added. The dispersion obtained by dispersing with a bead mill was added, and the mixture was stirred at 20 ° C. for 1 hour using a stirrer.
In this resin solution, 2 parts by mass of an antifoaming agent (manufactured by Enomoto Kasei Kogyo Co., Ltd., trade name: Disparon 230), 10 parts by mass of a rust preventive (trade name: CDA-1 by Adeka), a phosphazene compound (Fushimi Pharmaceutical Co., Ltd.) Product name: FP-100) 40 parts by mass, amine type epoxy resin (manufactured by Tohto Kasei Co., Ltd., product name: YH-434L) is mixed, and if necessary, a solvent such as γ-butyrolactone is added, The mixture was stirred at 20 ° C. for 30 minutes to obtain a thermosetting resin composition.

(Example 2)
A thermosetting resin was obtained in the same manner as in Example 1 except that the blending amount of CDA-1 in Example 1 was changed to 5 parts by mass.

(Example 3)
A thermosetting resin was obtained in the same manner as in Example 1 except that the blending amount of the phosphazene compound in Example 1 was 30 parts by mass.

Example 4
A thermosetting resin was obtained in the same manner as in Example 1 except that the blending amount of the phosphazene compound in Example 1 was 30 parts by mass and the blending amount of CDA-1 was 5 parts by mass.

(Example 5)
The same as Example 1 except that CDA-1 in Example 1 was not blended, 5 parts by mass of Irganox MD-1024 (Ciba Specialty Chemicals Co., Ltd.) was blended, and the blending amount of the phosphazene compound was changed to 30. Thus, a thermosetting resin was obtained.

(Example 6)
A thermosetting resin was obtained in the same manner as in Example 1, except that CDA-1 in Example 1 was not blended, 10 parts by mass of dysnet DB was blended, and the blending amount of the phosphazene compound was changed to 30.

(Example 7)
Heat was applied in the same manner as in Example 1 except that the polycarbonate-modified polyamideimide resin solution in Example 1 was not blended and 200 parts by mass of the polycarbonate-modified urethane resin solution obtained in Synthesis Example 2 (100 parts by mass of resin) was blended. A curable resin was obtained.

(Comparative Example 1)
A thermosetting resin was obtained in the same manner as in Example 1 except that CDA-1 in Example 1 was not blended and the blending amount of the phosphazene compound was changed to 30 parts by mass.

(Comparative Example 2)
A thermosetting resin was obtained in the same manner as in Example 1 except that the phosphazene compound in Example 1 was not blended and the blending amount of phosphaphenanthrene (sanko-BCA, Sanko Co., Ltd.) was 30 parts by mass.

(Comparative Example 3)
A thermosetting resin was obtained in the same manner as in Example 1 except that the phosphazene compound in Example 1 was not blended and the blending amount of aluminum phosphate (OP930, Clariant) was changed to 30 parts by mass.

(Comparative Example 4)
A thermosetting resin was obtained in the same manner as in Example 1 except that the blending amount of the phosphazene compound in Example 1 was 20 parts by mass.

(Comparative Example 5)
A thermosetting resin was obtained in the same manner as in Example 1, except that silica in Example 1 was not blended and 85 parts by mass of zinc borate (trade name: XB-ZF, manufactured by Borax, USA) was blended.

<Evaluation of thermosetting resin composition>
The thermosetting resin compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 5 were evaluated for insulation reliability, warpage, plating resistance, and flame retardancy according to the following methods. The obtained results are shown in Table 1.

(Insulation reliability)
Using the thermosetting resin compositions (resin compositions for film formation) obtained in Examples 1 to 7 and Comparative Examples 1 to 5, a comb-like shape (line width 20 μm, space width 20 μm) was formed on the polyimide substrate. The printed wiring board was printed so as to cover the same electrode of the wiring board provided with a copper electrode (tin-plated). Printing was performed at a printing speed of 100 mm / sec using a printing machine (trade name: LS-34GX manufactured by Neurong Co., Ltd.) and a mesh plate (150 mesh manufactured by Murakami Co., Ltd.). The above wiring board was heated at 150 ° C. for 90 minutes in an air atmosphere to cure the film forming resin composition to obtain a coated wiring board.
Three sets of the above-mentioned wiring boards with a coating were prepared, and a continuous resistance measuring machine (trade name: Ion Migration Tester MIG-8600, manufactured by IMV Corporation) and an unsaturated pressure cooker (trade name: HAST PC-422R8D, manufactured by Hirayama Manufacturing Co., Ltd.). ) Was used to measure resistance when energized for 100 hours under the conditions of a temperature of 120 ° C., a humidity of 85%, and an applied voltage of 60 V (DC). The ratio of the resistance value of 10 ⁷ Ω or more among the three sets of wiring boards was determined. In the table, 100%: when all three pieces hold a resistance value of 10 ⁷ Ω or more, 66%: when two pieces hold a resistance value of 10 ⁷ Ω or more, 33%: 1 When one piece has a resistance value of 10 ⁷ Ω or more, 0%: All three pieces have a resistance value of less than 10 ⁷ Ω.

(Flame retardance)
The thermosetting resin compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 5 were etched on a copper foil of a three-layer TAB substrate including a polyimide film having a thickness of 65 μm including an adhesive layer. On the obtained 2 layer TAB base material, it printed by the coating-film thickness which is 50 micrometers in thickness after hardening, and it heated at 150 degreeC for 90 minutes, and was hardened. From this film, five test pieces for a combustion test cut into a length of 127 mm and a width of 12.7 mm were produced.
Using these test pieces, a combustion test according to the UL94 vertical test standard was performed. “V-0 equivalent” shown in the table means that the flame of the test piece does not reach the clamp and the time from flame contact to flame extinction is 10 seconds or less. It means that the flame of the test piece reached the clamp in a few seconds later, and the test piece was completely burned.

(warp)
The resin composition for film formation obtained by coating thickness which becomes 10 micrometers in thickness after hardening to the COF base material provided with the polyimide film whose length is 43 mm, width 48 mm, and thickness 40 micrometers is length 24mm, width 41mm The range was printed and heated at 150 ° C. for 90 minutes to thermally cure. The coated surface was placed on a surface plate and the warp height was evaluated. Samples with a warp height of 10 mm or more were marked with ×, and those with less than that were marked with ○.

(Plating resistance)
The resin composition for film formation obtained by coating thickness which becomes 10 micrometers in thickness after hardening to the COF base material provided with the polyimide film whose length is 43 mm, width 48 mm, and thickness 40 micrometers is length 24mm, width 41mm The range was printed and heated at 150 ° C. for 90 minutes to thermally cure.
These test pieces are immersed in a 70 ° C. Sn plating solution (trade name: LT-34, manufactured by Co., Ltd.) for 5 minutes, washed with ion exchange water at 80 ° C. for 10 minutes, and then dried at 100 ° C. for 10 minutes. Went. The thickness of the resin composition for film formation before and after the Sn plating was measured, and the sample whose thickness decreased after the Sn plating solution treatment was evaluated as “x”, and the sample whose thickness did not change before and after the treatment was evaluated as “◯”.

  As shown in Table 1, the protective film formed from the thermosetting resin compositions of Examples 1 to 7 continuously applied a voltage of DC 60 V for 100 hours under an environment of a temperature of 120 ° C. and a humidity of 85%. However, it was found that sufficient insulation resistance was maintained. In addition, the protective films formed from the thermosetting resin compositions of Examples 1 to 7 have small warpage after curing, and the elution of the cured film components into the Sn plating solution is not confirmed, and the film has sufficient flame retardancy. I found out.

Claims (6)

  (A) a resin having an acid anhydride group and / or carboxyl group in the molecule, (B) an epoxy resin, (C) a phosphazene compound, (D) an inorganic filler, (E) a rust inhibitor, Containing thermosetting resin composition. The thermosetting resin composition according to claim 1, wherein the (A) resin has a structure represented by the following general formula (1).

[In general formula (1), a plurality of R's each independently represents an alkylene group having 1 to 20 carbon atoms, X represents a divalent organic group, and m and n each independently represents an integer of 1 to 30. When n is 2 or more, n Xs may be the same or different. ]   The thermosetting resin composition of Claim 1 or 2 used in order to form the protective film of a flexible wiring board. A first step of printing the thermosetting resin composition according to any one of claims 1 to 3 on the wiring pattern of the flexible wiring board provided with the wiring pattern;
A second step of thermosetting the printed thermosetting resin composition to form a protective film;
A method for forming a protective film on a flexible wiring board. The wiring pattern is Sn plated,
The method for forming a protective film on a flexible wiring board according to claim 4, wherein in the second step, the printed thermosetting resin composition is heated at 80 to 160 ° C. to form a protective film. The protective film which consists of a hardened | cured material of the thermosetting resin composition provided on the base material, the wiring pattern provided on this base material, and this wiring pattern as described in any one of Claims 1-3 And a flexible wiring board.