JP2010275503A - Thermosetting resin composition, method of 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 resistance even when not containing a halogen flame retardant, excellent in filler dispersibility, hardly generating bleeding between wiring even when printing on a wiring board to form a hardened film, and capable of sufficiently decrease the warp of a substrate after hardening, a method of forming a protective film of a flexible wiring board using the same, and a flexible wiring board. <P>SOLUTION: The thermosetting resin composition which solves the above problem comprises a resin (A) having an acid anhydride group and/or a carboxyl group, an epoxy resin (B), and a filler (C) wherein the filler (C) includes zinc borate, and melamine cyanurate. <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, and a flexible wiring board. The present invention also relates to a thermosetting resin composition having thixotropic properties suitable for a coating method such as a screen printer, a dispenser, and a spin coater, and a film forming material comprising the same.

  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). Moreover, in order to improve the flame retardancy of a flexible substrate, a resin composition using a dehydration endothermic reaction or carbonized film formation by adding a metal oxide or a metal hydroxide is known (for example, Patent Documents). 6).

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

  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. Metal hydroxides such as aluminum hydroxide and magnesium hydroxide need to increase the blending amount in the resin composition in order to obtain sufficient flame retardancy. Therefore, when such a resin composition is used as a material for forming a film such as a protective film on a substrate, there may be a problem that the substrate is greatly warped after curing.

  On the other hand, with the recent minimization of wiring, there has been a problem of bleeding (bleeding) of resin or solvent contained in a material for forming a coating such as a protective film between the wirings. This problem tends to be improved by, for example, blending fillers such as inorganic fine particles and organic fine particles and highly solidifying the resin composition. However, in this case, defects are likely to occur in printability such as defoaming and leveling. Furthermore, when the dispersibility of the filler is poor, problems such as difficulty in application by printing occur. As another method, the use of a coupling agent is conceivable. However, the coupling agent easily generates outgas and may cause problems in the wettability and ACF adhesion of the underfill material. It is not desirable to eliminate bleed only by this.

  The present invention has been made in view of the above circumstances and has sufficient flame retardancy even when it does not contain a halogen-based flame retardant, has excellent dispersibility of the filler, and is printed on a wiring board. Even when a cured film is formed, a thermosetting resin composition that is unlikely to flow out between the wirings and that can sufficiently reduce the warping of the base material after curing, and a protective film for a flexible wiring board using the thermosetting resin composition An object is to provide a forming method and a flexible wiring board.

  The thermosetting resin composition of the present invention that solves the above problems comprises (A) a resin having an acid anhydride group and / or a carboxyl group in the molecule, (B) an epoxy resin, and (C) a filler. Contains (C) zinc borate and melamine cyanurate as fillers.

  According to the thermosetting resin composition of the present invention, by including the specific resin and zinc borate and melamine cyanurate as fillers, sufficient flame retardancy is achieved even when no halogen-based flame retardant is contained. In addition, it has excellent dispersibility of the filler, and even when it is printed on a wiring board to form a cured film, it does not easily flow out between the wirings, and warping of the substrate after curing is sufficiently small. can do.

  The content of melamine cyanurate in the thermosetting resin composition of the present invention is 5 to 50 parts by mass with respect to 100 parts by mass of the resin (A) from the viewpoints of dispersibility, defoaming time and flame retardancy. Preferably there is.

  Moreover, it is preferable that the said (A) resin has a polycarbonate frame | skeleton from a viewpoint of flexibility, a low elastic modulus, and high heat resistance.

［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、複数個のＸは同一であっても異なっていてもよい。］ Furthermore, from the viewpoint of low warpage, the (A) resin preferably has a structure represented by the following general formula (1).

[In 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, a plurality of X may be the same or different. ]

  It is preferable that content of the said (C) component in the thermosetting resin composition of this invention is 100-200 mass parts with respect to 100 mass parts of said (A) resin. When the content is less than 100 parts by mass, the viscosity and thixotropy coefficient of the resin composition become too low, the stringing of the resin composition increases, and the flow of the resin composition after printing increases, resulting in a film thickness Tends to be thin. As a result, the electrical characteristics may deteriorate. On the other hand, when the content exceeds 200 parts by mass, the viscosity and thixotropy coefficient of the resin composition become too high, and the transferability of the resin composition to the substrate is lowered and voids and pinholes in the printed film are formed. There is a tendency to increase.

  The thermosetting resin composition of the present invention further contains γ-butyrolactone from the viewpoints of printability such as defoaming and leveling properties, and suppression of bleeding (bleeding) of resin components and solvents between wirings. It is preferable.

  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 the wiring pattern of a flexible wiring board, a coating film having a good shape can be formed by printing, and the substrate is sufficiently warped. It is possible to form a protective film excellent in flame retardancy without using a halogen-based flame retardant.

  The method for forming a protective film for a flexible wiring board of the present invention includes a step of printing the thermosetting resin composition of the present invention on a wiring pattern of a flexible wiring board provided with a wiring pattern, and a printed thermosetting And a step of thermally curing the resin composition to form a protective film.

  According to the method for forming a protective film of a flexible wiring board of the present invention, the halogen-based flame retardant is added while sufficiently preventing warping of the base material through the above-described steps using the thermosetting resin composition of the present invention. Even if it is not used, a protective film excellent in flame retardancy can be formed satisfactorily.

  The present invention also provides a flexible wiring board comprising 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. Can be provided.

  According to the present invention, even when it does not contain a halogen-based flame retardant, it has sufficient flame retardancy, is excellent in dispersibility of the filler, and is printed on a wiring board to form a cured film. However, it is possible to provide a thermosetting resin composition that is less likely to flow out between wirings and that can sufficiently reduce the warpage of a base material after curing, a method for forming a protective film on a flexible wiring board using the same, and a flexible wiring board be able to.

  The thermosetting resin composition of the present invention contains (A) a resin having an acid anhydride group and / or carboxyl group in the molecule, (B) an epoxy resin, and (C) a filler. ) As filler, it contains zinc borate and melamine cyanurate.

  (A) Examples of resins having acid anhydride groups and / or carboxyl groups in the molecule include epoxy resins having a butadiene structure or a silicone structure, phenol resins, acrylic resins, polyurethanes, polybutadienes, water-added polybutadienes, polyesters, and polycarbonates. , Polyether, polysulfone, polytetrafluororesin, polysilicone, melamine resin, polyamide, polyamideimide, polyimide, etc., in which an acid anhydride group and / or carboxyl group is introduced into the main chain and / or side chain of the resin Is mentioned. These can be used individually by 1 type or in combination of 2 or more types. By introducing an acid anhydride group and / or a carboxyl group into the terminal and / or side chain of the resin, the reactivity with the epoxy resin, which is the component (B) described later, increases, so that the adhesiveness (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.

  The resin introduced with a carboxyl group 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.

  Examples of the resin into which the acid anhydride group has been introduced include an epoxy residue, an isocyanate residue, a hydroxyl group, and a carboxyl group that the resin has, and the following general formula (2) and / or the following general formula (3). It can obtain by making it react with the compound represented by these.

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

[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. ]

［一般式（３）中、Ｚ^２は、４価の有機基を表す。］

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

  The resin of component (A) used in the present invention is preferably flexible and has a low elastic modulus so as to be compatible with flexible substrates. In order to make the resin of component (A) flexible and have a low elastic modulus, introduction of a component capable of improving flexibility into the main chain of the resin can be mentioned, and as such a component, for example, polybutadiene Examples include a skeleton, a silicone resin skeleton, and a polycarbonate skeleton. Two or more of these skeletons may be introduced.

  In order to improve the heat resistance, electrical characteristics, moisture resistance, solvent resistance and chemical resistance of the cured film, it is possible to introduce a component capable of improving heat resistance into the main chain of the resin. As such a component, for example, polyimide, polyamideimide or 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 component (A) used in the present invention is, for example, a reaction between a 1,6-hexanediol-based polycarbonate diol and the like, a compound having a carboxyl group, a compound having an acid anhydride and / or a compound having an isocyanate group. It is obtained with.

  The component (A) is, for example, one or more selected from (a) component: a trivalent polycarboxylic acid having an acid anhydride group and a derivative thereof, and a tetravalent polycarboxylic acid having an acid anhydride group. And a component (b): an isocyanate compound or an 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。］
で示される化合物が挙げられる。 Examples of the trivalent polycarboxylic acid having an acid anhydride group and derivatives thereof include 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. ]
The compound shown by these is mentioned.

  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。］
で示されるテトラカルボン酸二無水物が挙げられる。これらは、単独で又は２種類以上を組み合わせて使用することができる。 Examples of the tetravalent polycarboxylic acid having an acid anhydride group include the following general formula (6):

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

A group selected from a plurality of groups represented by: ]
The tetracarboxylic dianhydride shown by these is mentioned. These can be used alone or in combination of two or more.

  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。］
で示されるジイソシアネート類が挙げられる（以下、化合物（ｂ−１）と記す場合もある）。 As an isocyanate compound used as said (b) component, the following general formula (8):

[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. ]
(Hereinafter, it may be described as a compound (b-1).).

［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。］
で示されるカーボネートジオール類と、下記一般式（１０）：

［一般式（１０）中、Ｘは、二価の有機基である。］
で示されるジイソシアネート類とを反応させることにより得られる。 The compound (b-1) represented by the general formula (8) is represented by the following general formula (9):

[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. ]
Carbonate diols represented by the following general formula (10):

[In General Formula (10), X is a divalent organic group. ]
It can be obtained by reacting with a diisocyanate represented by the following formula.

  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. The product names “PLACCEL CD-205, 205PL, 205HL, 210, 210PL, 210HL, 220, 220PL, 220HL” manufactured by Daicel Chemical Industries, Ltd., and the product names “UM-CARB90 (made by Ube Industries, Ltd.) 1/1) "and the like. 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; Dimethane ether-4,4′-diisocyanate; benzophenone-4,4′-diisocyanate; diphenylsulfone-4,4′-diisocyanate; tolylene-2,4-diisocyanate; tolylene-2,6 M-xylylene diisocyanate; p-xylylene diisocyanate; naphthalene-2,6-diisocyanate; 4,4 ′-[2,2bis (4-phenoxyphenyl) propane] diisocyanate, hydrogenated diphenylmethane-2,4 '-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 mixing ratio of the carbonate diol represented by the general formula (9) and the diisocyanate represented by the general formula (10) is such that the ratio of the number of hydroxyl groups to the number of isocyanate groups is isocyanate group / hydroxyl group = 1.01 or more. It is preferable to do so.

  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 (b-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 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 specification, 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 ) / ΣN _i = ΣX _i M _i
[Mole fraction of the molecules of _{X i} = 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 (b), a compound other than the compound (b-1) (hereinafter referred to as compound (b-2)) can also be used. The compound (b-2) is not particularly limited as long as it is an isocyanate compound other than the compound (b-1). For example, diisocyanates represented by the general formula (9), trivalent or higher polyisocyanates, etc. Is mentioned. These can be used alone or in combination of two or more. The preferred range of the number average molecular weight of the isocyanate compound of the compound (b-2) is the same as that of the compound (b-1).

  In particular, from the viewpoint of heat resistance, it is preferable to use the compound (b-1) and the compound (b-2) in combination. In addition, when using a compound (b-1) and a compound (b-2) each independently, it is a compound (b-1) from points, such as a softness | flexibility as a protective film for flexible wiring boards, and a curvature improvement. Is preferably used.

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

  When the compound (b-1) and the compound (b-2) are used in combination, the equivalent ratio of compound (b-1) / compound (b-2) is 0.1 / 0.9 to 0.9 / 0.1. Is preferable, 0.2 / 0.8 to 0.8 / 0.2 is more preferable, 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 (b), examples of the amine compound include compounds obtained by converting the isocyanate group in the isocyanate compound of the component (b) 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).

  Further, the blending ratio of “a trivalent polycarboxylic acid having an acid anhydride group and its derivative, and one or more compounds selected from a tetravalent polycarboxylic acid having an acid anhydride group” as the component (a) Is preferably such that the ratio of the total number of carboxyl groups and acid anhydride groups in component (a) to the total number of isocyanate groups in component (b) is 0.6 to 1.4. It is more preferable to be 7 to 1.3, and it is particularly preferable to be 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、複数個のＸは同一であっても異なっていてもよい。］
で示される繰り返し単位を有するポリアミドイミド樹脂を得ることができる。 When the compound represented by the above general formula (4) is used as the component (a) and the compound (b-1) is used as the component (b), the following general formula (11):

[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, the plurality of X may be the same or different. ]
The polyamideimide resin which has a repeating unit shown by can be obtained.

［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、複数個の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。］
で示される繰り返し単位を有するポリアミドイミド樹脂を得ることができる。 When the compound represented by the general formula (5) is used as the component (a) and the compound (b-1) is used as the component (b), the following general formula (12):

[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, a plurality of X may be the same or different, and Y ¹ is —CH ₂ —, —CO—, —SO ₂ —, or —O—. ]
The polyamideimide resin which has a repeating unit shown by can be obtained.

［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。］
で示される繰り返し単位を有するポリイミド樹脂を得ることができる。 When the compound represented by the general formula (6) is used as the component (a) and the compound (b-1) is used as the component (b), the following general formula (13):

[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). ]
The polyimide resin which has a repeating unit shown by can be obtained.

  (A) Component: 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 (b) components: isocyanate The reaction with the compound or the amine compound can be carried out by heat condensation in the presence of an organic solvent, preferably a non-nitrogen-containing polar solvent, while removing the liberated carbon dioxide gas from the reaction system.

  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 formed. It is preferable to use a solvent that is suitable as a solvent for the thermosetting resin composition after the synthesis of the component (A). 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) component 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) and the component (b) may be a catalyst such as a tertiary amine, an alkali metal, an alkaline earth metal, a metal such as tin, zinc, titanium, or cobalt, or a metalloid compound, if necessary. Can be done below.

  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、Ｒ^１は、水素原子、炭素数１〜３のアルキル基を示し、ｐは１〜２０の実数を示し、ｎ又はｐ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。］ As the component (A) other than the above-described resin, for example, the same as when synthesizing the above (b-1) by mixing the general formula (9), the general formula (10), and the following general formula (15) The resin obtained by making it react on these conditions is mentioned. 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. Moreover, you may use another polyol component.

[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. , R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, p represents a real number of 1 to 20, and when n or p is 2 or more, a plurality of Xs are the same or different. May be. ]

  The number average molecular weight of the resin thus obtained is preferably 10,000 to 50,000, more preferably 15,000 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. When the number average molecular weight is less than 10,000, sticking between the cured film and the polyimide film tends to occur, and when the number average molecular weight exceeds 50,000, the viscosity of the resin increases, and the inorganic filler. This is not preferable because the mixing property of (inorganic filler) and / or organic filler (organic filler) and the workability such as screen printing tend to deteriorate.

  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 .; product name “DEN-” manufactured by Dow Chemical 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 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 of the present invention, the above epoxy resin can function as a curing agent.

  In the thermosetting resin composition of the present invention, 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 of the present invention is preferably 1 with respect to 100 parts by mass of the “resin having an acid anhydride group and / or carboxyl group” used as the component (A). -50 mass parts, More preferably, it is 2-45 mass parts, More preferably, it is 3-40 mass parts. 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. It tends 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.

  The thermosetting resin composition of the present invention contains at least zinc borate and melamine cyanurate as a filler (C).

  Melamine cyanurate is an organic salt composed of melamine and isocyanuric acid, and generally has a mica-like crystal structure. The melamine cyanurate used in the present invention is preferably particles having an average particle diameter of 0.01 to 5 μm, more preferably particles having an average particle diameter of 0.1 to 3 μm, from the viewpoint of the appearance of the cured film and dispersibility. preferable.

  The content of melamine cyanurate in the thermosetting resin composition of the present invention is a resin having an acid anhydride group and / or a carboxyl group as component (A) from the viewpoints of dispersibility, defoaming time and flame retardancy. The amount is preferably 5 to 50 parts by mass, more preferably 8 to 40 parts by mass, and particularly preferably 10 to 30 parts by mass with respect to 100 parts by mass.

  The zinc borate used in the present invention is preferably particles having an average particle diameter of 0.1 to 10 μm, more preferably particles having an average particle diameter of 0.2 to 6 μm, from the viewpoint of the appearance of the cured film and dispersibility. .

  The content of zinc borate in the thermosetting resin composition of the present invention is 100 masses of resin having an acid anhydride group and / or a carboxyl group as component (A) from the viewpoints of dispersibility, warpage and flame retardancy. It is preferably 50 to 200 parts by mass, more preferably 60 to 150 parts by mass, and particularly preferably 70 to 120 parts by mass with respect to parts.

  The thermosetting resin composition of the present invention can contain an inorganic filler (inorganic filler) other than zinc borate and / or an organic filler (organic filler) other than melamine cyanurate.

Examples of inorganic fillers other than zinc borate include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), titania (TiO ₂ ), 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 ), lead zirconate titanate (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), zinc oxide (ZnO), magnesium titanate ( MgO · TiO ₂ ), barium sulfate (BaSO ₄ ) and the like. These can be used alone or in combination of two or more. Among these, silica (SiO ₂ ) and hydrotalcite are preferably blended from the viewpoints of particularly good screen printability and electrical characteristics and maintaining flame retardancy.

［一般式（１７）中、Ｍ^１は、Ｍｇ^２＋、Ｆｅ^２＋、Ｚｎ^２＋、Ｃａ^２＋、Ｌｉ^２＋、Ｎｉ^２＋、Ｃｏ^２＋、Ｃｕ^２＋を示し、Ｍ^２は、Ａｌ^３＋、Ｆｅ^３＋、Ｍｎ^３＋を示し、ｘは２〜５の整数を示し、ｎは正の整数を示す。］ Hydrotalcite is a double hydroxide represented by the following general formula (17).

[In General Formula (17), M ¹ represents Mg ²⁺ , Fe ²⁺ , Zn ²⁺ , Ca ²⁺ , Li ²⁺ , Ni ²⁺ , Co ²⁺ , Cu ²⁺ , and M ² represents Al ³⁺ , Fe ³⁺ , Mn ^3+. , X represents an integer of 2 to 5, and n represents a positive integer. ]

Among these, magnesium and aluminum compounds represented by the following chemical composition formula are particularly preferable.
Mg ₆ Al ₂ (OH) ₁₆ CO ₃ .4H ₂ O
Such hydrotalcite is commercially available as HT-P (trade name, manufactured by Sakai Chemical Co., Ltd.).

  As the organic filler other than melamine cyanurate, 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. Moreover, organic bentonite, carbon (C), etc. can also be used as an organic filler.

  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. You may use these 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) Examples of the aromatic diamine compound include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, and 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. You may use these in mixture of 2 or more types.

  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 above (i) aromatic tetracarboxylic dianhydride and the above (ii) aromatic diamine compound are preferably reacted in an approximately equimolar amount in terms of film characteristics.

  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 the inorganic fine particles and / or organic fine particles to be blended in the thermosetting resin composition of the present invention, 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 lower limit of the particle diameter is preferably 0.01 μm from the viewpoint of producing inorganic fine particles and / or organic fine particles.

  The thermosetting resin composition of the present invention comprises (C) a filler (inorganic fine particles containing zinc borate and melamine cyanurate) in a resin solution obtained by dissolving a resin as component (A) in an organic solvent. It can be produced by dispersing organic fine particles) and mixing the component (B).

  Examples of the organic solvent that dissolves the component (A) include non-nitrogen-based polar solvents. 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. Since the resin of component (A) has different solubility depending on its composition, a solvent capable of dissolving the resin is selected and used.

  Among the organic solvents described above, γ-butyrolactone is particularly preferable from the viewpoints of printing properties such as defoaming property and leveling property, and suppression of outflow (bleed) between the resist and solvent wiring.

  As a method for dispersing inorganic and / or organic fine particles in the resin solution, any method may be used as long as roll kneading, mixer mixing, and the like, which are usually performed in the paint field, are applied and sufficient dispersion is performed.

  In the thermosetting resin composition of the present invention, a surfactant such as an antifoaming agent and a leveling agent, and a colorant such as a dye or a pigment, in order to improve the workability during coating and the film properties before and after the film formation. , Heat stabilizers, antioxidants, flame retardants, and lubricants can also be added.

  The thermosetting resin composition of the present invention preferably has a viscosity at 25 ° C. of 20 Pa · s to 80 Pa · s, more preferably 30 Pa · s to 50 Pa · s, on a rotary viscometer. 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 thermosetting resin composition of the present invention preferably has a thixotropic coefficient of 1.1 or more. When the thixotropy coefficient is less than 1.1, stringing of the resin composition increases, the flow of the resin composition after printing increases, and the film thickness tends to be reduced. From the viewpoint of film formability, the thixotropic coefficient is preferably 2 or less.

  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. Further, the thixotropy coefficient (TI value) of the resin composition was set to a sample amount of 0.2 ml or 0.5 ml using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., type RE80U), and the rotational speeds were 1 rpm and 10 rpm. It is expressed as a ratio η1 / η10 of the apparent viscosities η1 and η10 measured at 25 ° C.

  The thermosetting resin composition of the present invention can be suitably used for the purpose of forming a cured film by screen-curing on a wiring pattern of a flexible wiring board and then thermosetting to form 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. Examples of the plating layer include tin, nickel, and gold.

  The conditions for thermosetting are preferably 80 ° C. to 130 ° C., particularly preferably 90 ° C. to 120 ° C., from the viewpoint of preventing the diffusion of the plating layer and obtaining warpage and flexibility suitable as a protective film. It is not limited to this range, For example, it can also be made to harden | cure in the range of 50-200 degreeC, especially 50-140 degreeC. In addition, the heating time is 60 to 150 minutes, preferably 80 to 120 minutes from the viewpoint of preventing the plating layer from being diffused and obtaining warpage and flexibility suitable as a protective film, but is limited to this range. However, it can be cured in the range of 1 to 1000 minutes, for example, 5 to 300 minutes, especially 10 to 150 minutes.

  The thermosetting resin composition of the present invention is suitably used as a film forming material for various electric products and electronic parts by coating methods such as screen printing, dispenser, and spin coating. In particular, application by screen printing is preferable.

  In addition, the thermosetting resin composition of the present invention includes, for example, overcoat materials for electronic components such as semiconductor elements and printed circuit boards, liquid sealing materials, interlayer insulating films, surface protective films, solder resist layers, adhesive layers, and the like. It is used suitably as a material for forming. It can also be used for varnish for enameled wire, impregnated varnish for electrical insulation, cast varnish, mica, glass cloth, varnish for sheet, varnish for MCL laminate, friction material. Moreover, according to the thermosetting resin composition of the present invention, since the adhesion to the base material and the printing workability are excellent, it is possible to prevent the resin film from being peeled off from the circuit board or the like, and it is highly reliable. An electronic component can be obtained.

  The flexible wiring board of the present invention comprises a base material, a wiring pattern provided on the base material, a protective film provided on the wiring pattern and made of a cured product of the thermosetting resin composition of the invention. Is provided. As described above, according to the thermosetting resin composition of the present invention, it has sufficient flame retardancy even when it does not contain a halogen-based flame retardant, has excellent dispersibility of the filler, and is on the wiring board. Even when a cured film is formed by printing on the substrate, it is difficult for flow out between the wirings, and warping of the substrate after curing can be sufficiently reduced. Therefore, the flexible wiring board of the present invention is excellent in flame retardancy, sufficiently small in warpage, and excellent in reliability.

  Examples of the substrate include a polyimide film and a polyimide film with an epoxy adhesive layer. The thickness of a base material can be 10-200 micrometers. Moreover, the thermosetting resin composition of this invention is applicable also to the rigid board | substrate with the thickness of a base material exceeding 200 micrometers.

  The wiring pattern is preferably plated. Examples of the plating treatment include tin, nickel, and gold.

  The wiring width of the wiring pattern can be 10 to 100 μm. Moreover, the wiring space | interval of a wiring pattern can be 10-100 micrometers.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not restrict | limited to these.

<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. Next, 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 the mixture was 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.

<Preparation of thermosetting resin composition>
Example 1
200 parts by mass (100 parts by mass of resin content) of the polycarbonate-modified polyamideimide resin solution obtained in Synthesis Example 1 and 0.2 parts by mass of an antifoaming agent (trade name: Disparon 230 manufactured by Enomoto Kasei Kogyo Co., Ltd.) were mixed. And stirred at 20 ° C. for 30 minutes. In this resin solution, hydrotalcite (trade name: HT-1-NC, manufactured by Sakai Chemical Co., Ltd.) 40 parts by mass, silica (product name: R-974, manufactured by Nippon Aerosil Co., Ltd.) 10 parts by mass, zinc borate (rice Borax Co., Ltd. product name: XB-ZF, average particle size: 2 μm) 100 parts by mass, and melamine cyanurate (Made by Kagaku Co., Ltd. product name: MC-5S, average particle size: 0.5 μm) 10 parts by mass, A dispersion obtained by dispersing with a bead mill in advance in a part of a γ-butyrolactone resin solution was added and stirred at 20 ° C. for 1 hour using a stirrer. Furthermore, 10 parts by mass of an amine type epoxy resin (trade name: YH-434L, manufactured by Tohto Kasei Co., Ltd.) was added and stirred at 20 ° C. for 1 hour to obtain a thermosetting resin composition.

  The resulting thermosetting resin composition had a viscosity at 25 ° C. of 40 to 45 Pa · s, and a thixotropic coefficient (TI value) of 1.3 to 1.4. The viscosity of the resin composition was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., RE80U type) under the conditions of a sample amount of 0.2 ml, a rotation speed of 10 rpm, and 25 ° C. Further, the thixotropy coefficient (TI value) of the resin composition was determined by using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., RE80U type) under the conditions of a sample amount of 0.2 ml, a rotation speed of 1 rpm and 10 rpm, and 25 ° C. The apparent viscosity η1 and η10 of the composition was measured and determined from the ratio η1 / η10 of these η1 and η10.

(Example 2)
A thermosetting resin composition was obtained in the same manner as in Example 1 except that the blending amount of melamine cyanurate in Example 1 was 20 parts by mass. The resulting thermosetting resin composition had a viscosity at 25 ° C. of 50 to 55 Pa · s, and a thixotropy coefficient (TI value) of 1.3 to 1.4.

(Example 3)
A thermosetting resin composition was obtained in the same manner as in Example 1 except that the amount of melamine cyanurate in Example 1 was changed to 30 parts by mass. The obtained thermosetting resin composition had a viscosity at 25 ° C. of 65 to 70 Pa · s, and a thixotropic coefficient (TI value) of 1.5 to 1.6.

Example 4
A thermosetting resin composition was obtained in the same manner as in Example 1 except that butyl carbitol acetate was used instead of γ-butyrolactone. The obtained thermosetting resin composition had a viscosity at 25 ° C. of 40 to 45 Pa · s, and a thixotropic coefficient (TI value) of 1.3 to 1.4.

(Comparative Example 1)
A thermosetting resin composition was obtained in the same manner as in Example 1 except that melamine cyanurate was not blended. The obtained thermosetting resin composition had a viscosity at 25 ° C. of 30 to 35 Pa · s, and a thixotropic coefficient (TI value) of 1.3 to 1.4.

(Comparative Example 2)
A thermosetting resin composition was obtained in the same manner as in Example 1 except that 100 parts by mass of barium sulfate (trade name: B-31, manufactured by Sakai Chemical Co., Ltd.) was used instead of zinc borate. The resulting thermosetting resin composition had a viscosity at 25 ° C. of 50 to 55 Pa · s, and a thixotropy coefficient (TI value) of 1.3 to 1.4.

(Comparative Example 3)
A thermosetting resin composition was obtained in the same manner as in Example 1 except that 100 parts by mass of magnesium hydroxide (trade name: MGZ-1 manufactured by Sakai Chemical Co., Ltd.) was used instead of zinc borate. The obtained thermosetting resin composition had a viscosity at 25 ° C. of 65 to 70 Pa · s, and a thixotropic coefficient (TI value) of 1.5 to 1.6.

(Comparative Example 4)
A thermosetting resin composition was obtained in the same manner as in Comparative Example 3 except that the amount of magnesium hydroxide in Comparative Example 3 was 200 parts by mass. The obtained thermosetting resin composition had a viscosity at 25 ° C. of 75 to 80 Pa · s, and a thixotropic coefficient (TI value) of 1.6 to 1.7.

(Comparative Example 5)
A thermosetting resin composition was obtained in the same manner as in Example 1 except that the blending amount of hydrotalcite in Example 1 was 140 parts by mass and zinc borate was not blended. The resulting thermosetting resin composition had a viscosity at 25 ° C. of 50 to 55 Pa · s, and a thixotropy coefficient (TI value) of 1.3 to 1.4.

(Comparative Example 6)
A thermosetting resin composition was obtained in the same manner as in Example 1 except that the blending amount of melamine cyanurate in Example 1 was 110 parts by mass and zinc borate was not blended. The obtained thermosetting resin composition had a viscosity at 25 ° C. of 120 to 125 Pa · s, and a thixotropy coefficient (TI value) of 1.8 to 1.9.

<Evaluation of thermosetting resin composition>
About the thermosetting resin composition obtained by the Example and the comparative example, the dispersibility, curvature, bleeding, and flame retardance were evaluated in accordance with the following method. The obtained results are shown in Table 1.

(Dispersibility)
About the resin composition after adding an amine type epoxy resin and stirring at 20 degreeC for 1 hour, the state of the filler in a composition when 2 hours passed in static state was confirmed visually. The evaluation results are indicated by “◯” when the state is uniform, and by “X” when precipitation is observed or deposition is observed on the composition.

(Warpage)
The thermosetting resin composition was applied on a polyimide film having a thickness of 50 μm, a length of 35 mm, and a width of 20 mm with a coating thickness of 10 μm after curing, and heated at 120 ° C. for 60 minutes to be thermoset. . This film was placed on a surface plate with the application surface of the thermosetting resin composition facing down, and the distance (mm) from the surface plate to the apex of the warp of the film was measured, which was defined as the warp height.

(Bleed)
On a copper circuit (circuit width is 30 μm) using a copper foil of 18 μm, using a printing machine (manufactured by Neurong Co., Ltd., product name: LS-34GX) and a mesh plate (manufactured by Murakami Co., Ltd., 150 mesh), The thermosetting resin composition was printed on a 30 mm square at a printing speed of 100 mm / sec. This was allowed to stand for 3 minutes and then thermally cured at 120 ° C. for 1 hour. The amount of resin (μm) that flowed out from the printed edge portion on the copper circuit was measured with a 100 × microscope.

(Flame retardance)
The thermosetting resin composition was printed on a polyimide film having a thickness of 40 μm with a coating thickness of 25 μm after curing, and heated at 150 ° C. for 90 minutes to be thermoset. 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. In addition, 5/5 shown in the table means that all 5 sheets are V-0, and 0/5 means that all 5 sheets are burned.

  As shown in Table 1, the thermosetting resin compositions of Examples 1 to 4 which contain melamine cyanurate and zinc borate as fillers and γ-butyrolactone as a solvent have good dispersibility of the fillers. It was confirmed that the resin and solvent that flowed out between the wirings can be sufficiently reduced. Such a thermosetting resin composition can be suitably used as a material for film formation of various electrical products and electronic parts, such as protective film formation of flexible wiring boards, and it is said that highly reliable electronic parts are obtained. There is an effect.

  According to the present invention, even when it does not contain a halogen-based flame retardant, it has sufficient flame retardancy, is excellent in dispersibility of the filler, and is printed on a wiring board to form a cured film. However, it is possible to provide a thermosetting resin composition that is less likely to flow out between wirings and that can sufficiently reduce the warpage of a base material after curing, a method for forming a protective film on a flexible wiring board using the same, and a flexible wiring board be able to.

Claims (9)

(A) a resin having an acid anhydride group and / or a carboxyl group in the molecule, (B) an epoxy resin, and (C) a filler,
A thermosetting resin composition containing zinc borate and melamine cyanurate as the filler (C).   The thermosetting resin composition according to claim 1, wherein a content of the melamine cyanurate is 5 to 50 parts by mass with respect to 100 parts by mass of the (A) resin.   The thermosetting resin composition according to claim 1, wherein the (A) resin has a polycarbonate skeleton. The thermosetting resin composition according to any one of claims 1 to 3, wherein the (A) resin has a structure represented by the following general formula (1).

[In 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, a plurality of X may be the same or different. ]   The thermosetting resin composition according to any one of claims 1 to 4, wherein the content of the component (C) is 100 to 200 parts by mass with respect to 100 parts by mass of the resin (A).   The thermosetting resin composition according to any one of claims 1 to 5, further comprising γ-butyrolactone.   The thermosetting resin composition as described in any one of Claims 1-6 used in order to form the protective film of a flexible wiring board. Printing the thermosetting resin composition according to any one of claims 1 to 6 on the wiring pattern of the flexible wiring board provided with the wiring pattern;
A 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.   A protective film comprising a base material, a wiring pattern provided on the base material, and a cured product of the thermosetting resin composition according to any one of claims 1 to 6, provided on the wiring pattern. And a flexible wiring board.