Thermosetting resin composition, cured product, and flexible printed circuit board

Abstract

One embodiment relates to a thermosetting resin composition containing a resin having at least one group selected from the group consisting of an acid anhydride group and a carboxyl group, and a trifunctional amine-type epoxy resin.

Description

Technical Field

[0001] The present disclosure relates to a thermosetting resin composition, a kit for a thermosetting resin composition, a cured product, a film, a flexible printed substrate, and an electronic component. Background Art

[0002] Flexible printed circuit boards are widely used in electronic devices such as various displays and smartphones. Flexible printed circuit boards generally have a protective film for ensuring electrical insulation between wirings, preventing corrosion of wirings, etc. The protective film can be formed using a thermosetting resin composition, for example. The protective film is required to have properties suitable for its use.

[0003] For example, Patent Document 1 describes a thermosetting resin composition comprising (A) a resin having at least one acid anhydride group and / or carboxyl group, (B) an inorganic filler including hydrotalcite and silica, and (C) an epoxy resin.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-275114 Summary of the invention

[0007] Problems to be solved by the invention

[0008] Depending on the usage environment, dirt may be attached to the surface of electronic devices such as TV (Television) panels and PC (Personal Computer) monitors. To remove the dirt, end users may use detergents. If the detergent accidentally penetrates into the display and reaches the flexible printed circuit board, the detergent may cause a short circuit between the wirings if the protective film does not provide sufficient protection for the wiring.

[0009] Therefore, the present disclosure provides a thermosetting resin composition capable of obtaining a flexible printed circuit board and an electronic component having excellent resistance to detergents. In addition, the present disclosure provides a set comprising a first agent and a second agent for obtaining the above-mentioned thermosetting resin composition, and a cured product and a film obtained by using the above-mentioned thermosetting resin composition or the above-mentioned set. Furthermore, the present disclosure provides a flexible printed circuit board and an electronic component having excellent resistance to detergents.

[0010] Means for solving problems

[0011] The following are examples of embodiments of the present invention, but the present invention is not limited to the following embodiments.

[0012] One embodiment relates to a thermosetting resin composition comprising a resin having at least one group selected from the group consisting of an acid anhydride group and a carboxyl group, and a trifunctional amine-type epoxy resin.

[0013] Another embodiment relates to a kit for a thermosetting resin composition, which is used to obtain the above-mentioned thermosetting resin composition, and includes a first agent containing the above-mentioned resin and a second agent containing the above-mentioned trifunctional amine-type epoxy resin.

[0014] Another embodiment relates to a cured product obtained using the above-mentioned thermosetting resin composition or the above-mentioned kit for the thermosetting resin composition.

[0015] Another embodiment relates to a film obtained using the above-mentioned thermosetting resin composition or the above-mentioned kit for the thermosetting resin composition.

[0016] Another embodiment relates to a flexible printed circuit board obtained by using the above-mentioned thermosetting resin composition or the above-mentioned kit for the thermosetting resin composition.

[0017] Another embodiment relates to an electronic component obtained by using the above-mentioned thermosetting resin composition or the above-mentioned kit for the thermosetting resin composition.

[0018] Effects of the Invention

[0019] According to the present disclosure, a thermosetting resin composition capable of obtaining a flexible printed circuit board and an electronic component having excellent resistance to detergents can be provided. In addition, according to the present disclosure, a set comprising a first agent and a second agent for obtaining the above-mentioned thermosetting resin composition, and a cured product and a film obtained by using the above-mentioned thermosetting resin composition or the above-mentioned set can be provided. Furthermore, according to the present disclosure, a flexible printed circuit board and an electronic component having excellent resistance to detergents can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic front view showing a test piece for evaluating detergent resistance prepared in Examples.

[0021] Figure 2 Yes Figure 1 Schematic front view showing an enlarged view of the wiring portion of the test piece shown in FIG.

[0022] Figure 3 This is a schematic front view showing a state in which a test piece is brought into contact with a detergent in Examples.

[0023] Figure 4 This is a schematic perspective view showing a state in which a test piece is brought into contact with a detergent in Examples. DETAILED DESCRIPTION

[0024] The embodiments of the present invention are described. The present invention is not limited to the following embodiments. In addition, the following embodiments can be implemented individually or in combination. The combination of multiple embodiments is also included in the present invention.

[0025] In the numerical range recorded in stages in the present disclosure, the upper limit or lower limit recorded in a certain numerical range may also be replaced by the upper limit or lower limit of other numerical ranges. The upper limit or lower limit of the numerical range recorded in the present disclosure may also be replaced by the value shown in the embodiment. It is also possible to select a certain numerical value from the numerical value of the upper limit and the numerical value of the lower limit recorded in stages in the present disclosure, respectively, and set it as the numerical range of stages. The numerical value of the upper limit and the numerical value of the lower limit recorded in the present disclosure may also be replaced by the value shown in the embodiment.

[0026] In the present disclosure, each component may contain a plurality of corresponding substances. When a plurality of corresponding substances exist in a composition, the content or content of each component refers to the total content or content of the plurality of substances present in the composition unless otherwise specified.

[0027] In the present disclosure, each structure in a resin or polymer may also include multiple structures that match. When there are multiple structures that match each structure in a resin or polymer, the content or content of each structure refers to the total content or content of the multiple structures present in the resin or polymer unless otherwise specified.

[0028] In the present disclosure, the term "layer" includes continuous layers and discontinuous layers. The thickness of a "layer" may be uniform or non-uniform. The outer edge of a "layer" in the surface direction and the outer edge in the thickness direction may be clear or unclear, respectively. The same applies to a "film".

[0029] When the embodiments are described with reference to the drawings in the present disclosure, the configuration of the embodiments is not limited to the configuration shown in the drawings. In addition, the sizes of the components in each figure are conceptual sizes, and the relative relationship between the sizes of the components is not limited to the relationship shown in the drawings.

[0030] <Thermosetting resin composition>

[0031] In some embodiments, the thermosetting resin composition contains a resin having at least one group selected from the group consisting of an anhydride group and a carboxyl group and a trifunctional amine-type epoxy resin. In the present disclosure, the resin having at least one group selected from the group consisting of an anhydride group and a carboxyl group is sometimes referred to as "resin A", and at least one group selected from the group consisting of an anhydride group and a carboxyl group is sometimes referred to as "anhydride group or carboxyl group". In the present disclosure, the anhydride group may be a carboxylic anhydride group. The thermosetting resin composition may further contain any components such as a tetrafunctional amine-type epoxy resin, an epoxy resin other than the amine-type epoxy resin, an organic solvent, and an additive.

[0032] [Resin having anhydride group or carboxyl group]

[0033] Examples of the resin having an anhydride group or a carboxyl group include phenolic resins, acrylic resins, polyurethanes, polybutadiene, hydrogenated polybutadiene, polyesters, polycarbonates, polyethers, polysulfones, polytetrafluororesins, polysiloxanes, melamine resins, polyamides, polyamide-imides, polyimides, and the like, and resins having an anhydride group or a carboxyl group in the main chain, the side chain, or both the main chain and the side chain. The thermosetting resin composition may contain one type of resin having an anhydride group or a carboxyl group alone, or two or more types in combination.

[0034] In several embodiments, the thermosetting resin composition contains a polyamide-imide having an anhydride group or a carboxyl group. Polyamide-imide is a resin comprising an amide bond (amide group) and an imide bond (imide group). In the case where the thermosetting resin composition contains a polyamide-imide having an anhydride group or a carboxyl group, a cured product having excellent insulation and heat resistance and excellent resistance to detergents can be obtained. In the present disclosure, resistance to detergents is sometimes referred to as "detergent resistance". Polyamide-imide may have an anhydride group or a carboxyl group at the end of the molecular chain.

[0035] In several embodiments, the polyamide-imide may include a carbamate bond. The polyamide-imide including a carbamate bond can be synthesized by, for example, reacting a polyol with a polyisocyanate to obtain a polyisocyanate with a carbamate bond (sometimes referred to as "polyisocyanate A" in the present disclosure) and reacting it with a tricarboxylic acid compound. From the viewpoint of improved flexibility, the polyamide-imide may include a polyurethane structure in the molecule. Polyols may be used alone or in combination of two or more. Polyisocyanates may be used alone or in combination of two or more.

[0036] (Polyol)

[0037] As the polyol, for example, diols such as alicyclic diols, aliphatic diols, and diol compounds represented by the following formula (P1) can be cited. From the viewpoint of obtaining a cured product that maintains high insulation reliability and has excellent flexibility, the diol may include alicyclic diols. From the viewpoint of obtaining a cured product that can fully suppress warping and has excellent flexibility, the diol may include aliphatic diols. In the present disclosure, the property of suppressing warping is sometimes referred to as "low warping".

[0038] The alicyclic diol is a diol containing a divalent organic group having an alicyclic hydrocarbon group, and the carbon number of the alicyclic hydrocarbon group is, for example, 5 to 10. Examples of the alicyclic diol include 5-membered cyclic diols such as 1,2-cyclopentane dimethanol, 1,3-cyclopentane dimethanol, and bis(hydroxymethyl)tricyclo[5.2.1.0]decane; and 6-membered cyclic diols such as 1,2-cyclohexane diol, 1,3-cyclohexane diol, 1,4-cyclohexane diol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and 2,2-bis(4-hydroxycyclohexyl)-propane.

[0039] The aliphatic diol is a diol containing a divalent organic group having an aliphatic hydrocarbon group (wherein the divalent organic group does not have an alicyclic hydrocarbon group), and the carbon number of the aliphatic hydrocarbon group is, for example, 1 to 18. The aliphatic hydrocarbon group may be linear or branched. Examples of the aliphatic diol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, and 1,6-hexanediol.

[0040] The diol may be, for example, a diol compound represented by the following formula (P1).

[0041] [Chemical formula 1]

[0042]

[0043] In the formula, R p R represents a divalent organic group having an alicyclic hydrocarbon group having 5 to 10 carbon atoms, or a divalent organic group having an aliphatic hydrocarbon group having 1 to 18 carbon atoms (wherein the divalent organic group does not have an alicyclic hydrocarbon group), and n represents a number of 1 to 30. p They may be the same or different from each other. The divalent organic group having an aliphatic hydrocarbon group is, for example, a linear or branched alkylene group. n is the average number of units.

[0044] The diol compound represented by formula (P1) may be, for example, p A copolycarbonate diol comprising a structure derived from a diol containing a divalent organic group having an alicyclic hydrocarbon group and a structure derived from a diol containing a divalent organic group having an aliphatic hydrocarbon group.

[0045] In the copolycarbonate diol, from the viewpoint of obtaining excellent insulation reliability and folding resistance, the molar ratio of the structure derived from the diol containing a divalent organic group having an aliphatic hydrocarbon group to the structure derived from the diol containing a divalent organic group having an alicyclic hydrocarbon group is, for example, 0.1 or more, 0.3 or more, or 0.5 or more. From the same viewpoint, the molar ratio is, for example, 2 or less, 1 or less, or 0.5 or less. The molar ratio is, for example, 0.1 to 2, 0.3 to 1, 0.1 to 0.5, or 0.5 to 1. n is, for example, 10 to 30, 15 to 28, or 20 to 25.

[0046] For example, the diol containing a divalent organic group having an alicyclic hydrocarbon group is 1,4-cyclohexanedimethanol, and the diol containing a divalent organic group having an aliphatic hydrocarbon group may be 1,6-hexanediol. In other words, the diol compound represented by formula (P1) may be a copolymer using 1,4-cyclohexanedimethanol and 1,6-hexanediol, that is, a copolycarbonate diol. A copolycarbonate diol having a molar ratio of 1,4-cyclohexanedimethanol to 1,6-hexanediol of 3 / 1 can be commercially obtained as "UM-90 (3 / 1)" manufactured by UBE Co., Ltd.; a copolycarbonate diol having a molar ratio of 1,4-cyclohexanedimethanol to 1,6-hexanediol of 1 / 1 is commercially available as "UM-90 (1 / 1)" manufactured by UBE Co., Ltd.; and a copolycarbonate diol having a molar ratio of 1 / 3 to 1,6-hexanediol is commercially available as "UM-90 (1 / 3)" manufactured by UBE Co., Ltd.

[0047] The diol compound represented by formula (P1) may be, for example, R p A carbonate diol having a structure derived from a diol containing a divalent organic group having an aliphatic hydrocarbon group. In the carbonate diol, n is, for example, 2 to 10, 3 to 8, or 4 to 6.

[0048] For example, the diol containing a divalent organic group having an aliphatic hydrocarbon group may be 1,6-hexanediol. In other words, the diol compound represented by formula (P1) may be a carbonate diol which is a polymer using 1,6-hexanediol. pThe diol compound is a divalent organic group having an aliphatic hydrocarbon group, for example, α,ω-poly(hexamethylene carbonate)diol and α,ω-poly(3-methyl-pentamethylene carbonate)diol. Commercially available products include PLACCELC-205, 205PL, 205HL, 210, 210PL, 210HL, 220, 220PL, 220HL manufactured by Daicel Corporation; PCDL T-5651, T-5652, T-6001, T-6002, G-3452, PCDX-55 manufactured by Asahi Kasei Corporation; UH-50, 100, 200, 300, UHC-50-100, 200 manufactured by UBE Corporation, etc.

[0049] The number average molecular weight of the diol compound represented by formula (P1) is, for example, 300 or more, 500 or more, or 700 or more. The number average molecular weight is, for example, 4,000 or less, 3,000 or less, or 2,000 or less. The number average molecular weight is, for example, 300 to 4,000, 500 to 3,000, or 700 to 2,000. In the present disclosure, the number average molecular weight is measured by gel permeation chromatography (GPC) and converted using a standard curve of standard polystyrene. Details of the method for measuring the number average molecular weight are shown in the Examples.

[0050] In the polyamide-imide, from the viewpoint of obtaining excellent insulation reliability and folding resistance, the molar ratio of the structure derived from the diol containing a divalent organic group having an aliphatic hydrocarbon group to the structure derived from the diol containing a divalent organic group having an alicyclic hydrocarbon group is, for example, 0.1 or more, 0.3 or more, or 0.4 or more. From the same viewpoint, the molar ratio is, for example, 2 or less, 1 or less, or 0.6 or less. The molar ratio is, for example, 0.1 to 2, 0.3 to 1, or 0.4 to 0.6.

[0051] From the viewpoint of being easily endowed with characteristics such as an increase in glass transition temperature and an increase in elastic modulus, and obtaining excellent insulation reliability, the ratio of the structure derived from alicyclic diol is based on the mass of polyamide-imide, for example, 0.1% by mass or more, 3% by mass or more, or 5% by mass or more. From the viewpoint of suppressing the increase in the crystallinity of polyamide-imide and easily obtaining good solubility in a solvent, the ratio of the structure derived from alicyclic diol is based on the mass of polyamide-imide, for example, 30% by mass or less, 25% by mass or less, or 20% by mass or less. The ratio of the structure derived from alicyclic diol is based on the mass of polyamide-imide, for example, 0.1 to 30% by mass, 3 to 25% by mass, or 5 to 20% by mass. In the calculation of the ratio, "structure derived from alicyclic diol" refers to the part obtained by removing two hydroxyl groups from alicyclic diol. For example, when the alicyclic diol is 1,4-cyclohexanedimethanol, the portion obtained by removing two hydroxyl groups from 1,4-cyclohexanedimethanol is regarded as a "structure derived from the alicyclic diol" and the ratio is calculated.

[0052] The diol may be, for example, polyether diol, polyester diol, polycaprolactone diol, silicone diol, or the like.

[0053] As the polyol, a triol having three hydroxyl groups may be used in combination with a diol. Examples of the triol include 1,2,3-propanetriol (glycerol) and 1,2,4-butanetriol.

[0054] (Polyisocyanate)

[0055] As a polyisocyanate, the diisocyanate compound represented by following formula (P3) is mentioned, for example.

[0056] [Chemical formula 2]

[0057] OCN-X-NCO (P3)

[0058] In the formula, X represents a divalent organic group.

[0059] Examples of the divalent organic group represented by X in formula (P3) include an alkylene group having 1 to 20 carbon atoms; an arylene group such as a phenylene group or a naphthylene group which is unsubstituted or substituted with a lower alkyl group having 1 to 5 carbon atoms such as a methyl group, or a lower alkoxy group having 1 to 5 carbon atoms such as a methoxy group; an organic group in which two of the above arylene groups are bonded via a lower alkylene group having 1 to 5 carbon atoms, an oxy group (-O-), a carbonyl group (-CO-), or a sulfonyl group (-SO2-); an organic group in which two lower alkylene groups having 1 to 5 carbon atoms are bonded via the above arylene group, etc. The number of carbon atoms of the alkylene group may be, for example, 1 to 18. The divalent organic group represented by X is selected from groups having an aromatic ring such as a phenylene group, a benzylene group, a naphthylene group, a diphenylmethane-4,4'-diyl group, and a diphenylsulfone-4,4'-diyl group, and groups obtained by hydrogenating these groups.

[0060] Examples of the diisocyanate compound represented by formula (P3) 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 diisocyanate compounds such as "isocyanate", diphenylmethane-4,4'-diisocyanate, diphenylmethane-3,3'-diisocyanate, and diphenylmethane-3,4'-diisocyanate; diphenyl ether-4,4'-diisocyanate; benzophenone-4,4'-diisocyanate; diphenyl sulfone-4,4'-diisocyanate; toluene-2,4-diisocyanate (2,4-toluene diisocyanate); toluene-2,6-diisocyanate (2,6-toluene diisocyanate); m-xylylene diisocyanate; p-xylylene diisocyanate; 1,5-naphthalene diisocyanate; 4,4'-[2,2-bis(4-phenoxyphenyl)propane] diisocyanate and the like.

[0061] Examples of the diisocyanate compound represented by formula (P3) include hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, trans-cyclohexane-1,4-diisocyanate, lysine diisocyanate, and aliphatic or alicyclic isocyanates such as hydrogenated products of aromatic isocyanates.

[0062] The diisocyanate compound represented by formula (P3) may be stabilized by a blocking agent for isocyanate groups to prevent changes over time. Examples of the blocking agent include hydroxyacrylates, alcohols represented by methanol, phenols, and oximes, but are not particularly limited.

[0063] As the polyisocyanate, a trifunctional or higher functional polyisocyanate may be used together with the diisocyanate compound represented by the formula (P3).

[0064] (Reaction method, etc.)

[0065] The reaction of the polyol and the polyisocyanate can be carried out by heating and condensing them in the presence of an organic solvent, for example, a non-nitrogen-containing polar solvent. The organic solvent can be used alone or in combination of two or more.

[0066] The non-nitrogen-containing polar solvent is selected from, for example, 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 cyclopentane sulfone; ester solvents such as γ-butyrolactone and cellosolve acetate; ketone solvents such as cyclohexanone and methyl ethyl ketone; and aromatic hydrocarbon solvents such as toluene and xylene.

[0067] A solvent capable of dissolving the generated resin may be selected and used. A substance suitable for being directly used as a solvent for a thermosetting resin composition after synthesis may be selected and used. From the viewpoint of having a high boiling point, being able to react efficiently in a homogeneous system, and being suitable for printing operations when forming a protective film on a flexible wiring board or the like, the solvent may be γ-butyrolactone.

[0068] From the viewpoint of suppressing the increase of viscosity during the reaction and performing the synthesis of polyisocyanate A well, the amount of the solvent used is, for example, 0.8 times (mass ratio) or more based on the total mass of the raw materials used in the synthesis of polyisocyanate A. From the viewpoint of suppressing the decrease in the reaction rate, the amount of the solvent used is, for example, 5.0 times (mass ratio) or less.

[0069] From the viewpoint of suppressing the prolonged reaction, the reaction temperature is, for example, 70° C. or higher, 75° C. or higher, or 80° C. or higher. From the viewpoint of preventing gelation during the reaction, the reaction temperature is, for example, 210° C. or lower, 190° C. or lower, or 180° C. or lower. The reaction time can be appropriately selected depending on the capacity of the reaction container, the reaction conditions used, and the like.

[0070] If necessary, the reaction may be carried out in the presence of a catalyst such as a tertiary amine, an alkali metal, an alkaline earth metal, a metal such as tin, zinc, titanium, cobalt, or a semi-metal compound.

[0071] The mixing ratio when the polyol and the polyisocyanate are reacted may be appropriately adjusted in consideration of, for example, the number average molecular weight of the polyisocyanate A to be produced and whether the polyisocyanate A to be produced is a polyisocyanate having an isocyanate group at a terminal.

[0072] To synthesize the polyisocyanate A having terminal isocyanate groups, the mixing ratio of the polyol and the polyisocyanate can be adjusted so that the ratio of the number of isocyanate groups to the number of hydroxyl groups (number of isocyanate groups / number of hydroxyl groups) is, for example, 1.01 to 2.0.

[0073] Polyisocyanate A is a compound containing a urethane bond, and contains, for example, a structure represented by the following formula (P2).

[0074] [Chemical formula 3]

[0075]

[0076] In the formula, R p represents a divalent organic group having an alicyclic hydrocarbon group having 5 to 10 carbon atoms, or a divalent organic group having an aliphatic hydrocarbon group having 1 to 18 carbon atoms (wherein the divalent organic group does not have an alicyclic hydrocarbon group), X represents a divalent organic group, and n represents a number of 1 to 30. p They may be the same or different. * indicates the bonding position with other structures. p The description of and X applies to R of formula (P2) p and X.

[0077] The number average molecular weight of polyisocyanate A is, for example, 500 or more, 1,000 or more, or 1,500 or more. The number average molecular weight of polyisocyanate A is, for example, 30,000 or less, 25,000 or less, or 20,000 or less. The number average molecular weight of polyisocyanate A is, for example, 500 to 30,000, 1,000 to 25,000, or 1,500 to 20,000.

[0078] (Tricarboxylic acid compound)

[0079] The tricarboxylic acid compound may be a trivalent polycarboxylic acid having an acid anhydride group and a derivative thereof. The derivative is, for example, an ester. Examples of the tricarboxylic acid compound include compounds represented by the following formula (P4) or (P5).

[0080] [Chemical formula 4]

[0081]

[0082] In the formula (P4), R represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a phenyl group.

[0083] [Chemical formula 5]

[0084]

[0085] In formula (P5), R represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a phenyl group, and Y represents -CH2-, -CO-, -SO2-, or -O-.

[0086] Specific examples of the tricarboxylic acid compound include trimellitic anhydride, benzenetricarboxylic anhydride, naphthalenetricarboxylic anhydride, 3,4,4'-benzophenonetricarboxylic anhydride, 3,4,4'-biphenyl ethertricarboxylic anhydride, 3,4,4'-biphenyltricarboxylic anhydride, 2,3,2'-biphenyltricarboxylic anhydride, 3,4,4'-biphenylmethanetricarboxylic anhydride, and 3,4,4'-biphenylsulfonetricarboxylic anhydride.

[0087] A dicarboxylic acid compound which is a divalent polycarboxylic acid or a derivative thereof, or a tetracarboxylic acid compound which is a tetravalent polycarboxylic acid or a derivative thereof may be used together with the tricarboxylic acid compound.

[0088] (Reaction method, etc.)

[0089] The above-mentioned organic solvents can be used for the reaction between the polyisocyanate A and the tricarboxylic acid compound. The solvent used in the reaction may be, for example, the same organic solvent as that used in the reaction between the polyol and the polyisocyanate.

[0090] From the viewpoint of suppressing the rise of viscosity during solvent reaction and performing the synthesis of polyamide-imide well, the usage amount of solvent is, for example, more than 0.8 times (mass ratio) based on the total mass of the raw materials used in the synthesis of polyamide-imide. From the viewpoint of suppressing the reduction of reaction speed, the usage amount of solvent is, for example, less than 5.0 times (mass ratio).

[0091] From the viewpoint of suppressing the prolonged reaction, the reaction temperature is, for example, 70° C. or higher, 75° C. or higher, or 80° C. or higher. From the viewpoint of preventing gelation during the reaction, the reaction temperature is, for example, 210° C. or lower, 190° C. or lower, or 180° C. or lower. The reaction time can be appropriately selected depending on the capacity of the reaction container, the reaction conditions used, and the like.

[0092] It is also possible to react polyisocyanate A and other polyisocyanates (sometimes referred to as "polyisocyanate B" in this disclosure) with a tricarboxylic acid compound to obtain a polyamide-imide. As polyisocyanate B, there is no particular limitation as long as it is an isocyanate other than polyisocyanate A, and for example, diisocyanate compounds represented by formula (P3), polyisocyanates with a valence of more than 3, etc. can be listed. Polyisocyanate A and polyisocyanate B can be used alone or in combination of two or more.

[0093] When polyisocyanate B is used in combination, 50 to 100% by mass of the aromatic polyisocyanate may be used based on the total mass of the polyisocyanate B. From the viewpoint of balance among solubility, mechanical properties, and cost, the aromatic polyisocyanate includes, for example, at least one selected from 4,4'-diphenylmethane diisocyanate and tolylene diisocyanate.

[0094] When polyisocyanate B is used in combination, the molar ratio of polyisocyanate A / polyisocyanate B is, for example, 0.1 / 0.9 to 0.9 / 0.1, 0.2 / 0.8 to 0.8 / 0.2, or 0.3 / 0.7 to 0.7 / 0.3. When the molar ratio is within the above range, good adhesion between the cured product and an adherend such as a substrate with wiring is easily obtained.

[0095] An amine compound may be used together with the polyisocyanate A. Examples of the amine compound include compounds obtained by converting the isocyanate group in the diisocyanate compound represented by the formula (P3) into an amino group. The conversion of the isocyanate group into the amino group can be performed by a known method.

[0096] In the reaction of polyisocyanate A and tricarboxylic acid compound, from the viewpoint of increasing the number average molecular weight of polyamide-imide, the ratio of the total number of anhydride groups and carboxyl groups in the acid anhydride or carboxylic acid used to the total number of isocyanate groups in the isocyanate used (the total number of anhydride groups and carboxyl groups / the total number of isocyanate groups) is, for example, 0.6 or more, 0.7 or more, or 0.8 or more. From the same viewpoint, the ratio of the total number of carboxyl groups to the anhydride groups is, for example, 1.4 or less, 1.3 or less, or 1.2 or less. The ratio of the total number of carboxyl groups to the anhydride groups is, for example, 0.6 to 1.4, 0.7 to 1.3, or 0.8 to 1.2.

[0097] From the viewpoint of preventing the decrease of weather resistance or detergent resistance, the number average molecular weight of the polyamideimide is, for example, 5,000 or more, 6,000 or more, or 7,000 or more. From the viewpoint of being well dissolved in a solvent and being difficult to be insoluble during synthesis, the number average molecular weight is, for example, 65,000 or less, 60,000 or less, 50,000 or less, or 25,000 or less. The number average molecular weight of the polyamideimide is, for example, 5,000 to 60,000, 6,000 to 50,000, or 7,000 to 25,000.

[0098] From the viewpoint of preventing the decrease of weather resistance or solvent resistance, the weight average molecular weight of the polyamideimide is, for example, 10,000 or more, 20,000 or more, or 30,000 or more. From the viewpoint of good dissolution in a solvent and difficulty in being insoluble during synthesis, the number average molecular weight is, for example, 65,000 or less, 60,000 or less, or 50,000 or less. The weight average molecular weight of the polyamideimide is, for example, 10,000 to 65,000, 20,000 to 60,000, or 30,000 to 50,000.

[0099] In the present disclosure, the number average molecular weight and the weight average molecular weight are values ​​measured by gel permeation chromatography (GPC) and converted using a calibration curve of standard polystyrene. Details of the method for measuring the number average molecular weight and the weight average molecular weight are described in the Examples.

[0100] From the viewpoint of making the curing sufficient, obtaining good weather resistance, bending resistance, etc., the acid value of the polyamideimide is, for example, 5 mgKOH / g or more, 7 mgKOH / g or more, or 10 mgKOH / g or more. From the viewpoint of obtaining good low warpage, thermosetting and insulation reliability, the acid value of the polyamideimide is, for example, 30 mgKOH / g or less, 20 mgKOH / g or less, or 15 mgKOH / g or less. The acid value of the polyamideimide is, for example, 5 to 30 mgKOH / g, 7 to 20 mgKOH / g, or 10 to 15 mgKOH / g. The acid value can be measured by neutralization titration. The details of the method for measuring the acid value are shown in the examples.

[0101] The polyamideimide obtained by the above production method may have, for example, a carboxyl group or an acid anhydride group at the end of the molecular chain. When the polyamideimide has a urethane bond and has a carboxyl group or an acid anhydride group at the end of the molecular chain, flexibility and insulation reliability can be improved.

[0102] The resin A contained in the thermosetting resin composition is not limited to the polyamide-imide having an anhydride group or a carboxyl group. In several embodiments, the thermosetting resin composition contains a polyurethane having an anhydride group or a carboxyl group. From the viewpoint of improving flexibility, the polyurethane may contain an ester bond in the molecule. The polyurethane may contain a fluorene structure and may contain a Cardo structure. In several embodiments, the thermosetting resin composition contains a polyimide having an anhydride group or a carboxyl group. From the viewpoint of improving flexibility, the polyimide may contain a carbonate structure in the molecule. The polyimide may contain a fluorene structure and may contain a Cardo structure.

[0103] [Epoxy resin]

[0104] The thermosetting resin composition contains a trifunctional amine epoxy resin. The thermosetting resin composition may further contain a tetrafunctional amine epoxy resin. The thermosetting resin composition may further contain an epoxy resin other than the amine epoxy resin (sometimes referred to as a "non-amine epoxy resin" in the present disclosure). In the present disclosure, the trifunctional amine epoxy resin is a compound having three epoxy groups in the molecule, which contains a secondary amine structure, a tertiary amine structure, or both, and the tetrafunctional amine epoxy resin is a compound having four epoxy groups in the molecule, which contains a secondary amine structure, a tertiary amine structure, or both. The non-amine epoxy resin is a compound having one or more epoxy groups without containing either a secondary amine structure or a tertiary amine structure in the molecule. The trifunctional amine epoxy resin, the tetrafunctional amine epoxy resin, and the non-amine epoxy resin may each be contained in the thermosetting resin composition alone or in combination of two or more.

[0105] (Trifunctional amine type epoxy resin)

[0106] The trifunctional amine epoxy resin may have, for example, a monoglycidylamino group, a diglycidylamino group, or both. The trifunctional amine epoxy resin may further have a glycidyloxy group. The trifunctional amine epoxy resin includes, for example, an epoxy resin represented by the following formula (E1).

[0107] [Chemical formula 6]

[0108]

[0109] (Where R 1 It represents a divalent organic group.

[0110] As R 1 Examples of R include the groups exemplified in the description of X in the diisocyanate compound represented by the above formula (P3). 1 For example, it may be an arylene group such as unsubstituted or substituted with a lower alkyl group having 1 to 5 carbon atoms such as a methyl group, or a lower alkoxy group having 1 to 5 carbon atoms such as a methoxy group, a naphthyl group, etc.; it may be an unsubstituted or substituted phenylene group with a lower alkyl group having 1 to 5 carbon atoms such as a methyl group; it may be an unsubstituted phenylene group or a methylphenylene group.

[0111] When the thermosetting resin composition contains a trifunctional amine-type epoxy resin, a flexible printed circuit board and an electronic component having excellent detergent resistance can be obtained. The reason for this is, for example, presumed as follows. However, the present invention is not limited to the following.

[0112] If the thermosetting resin composition contains a trifunctional amine-type epoxy resin, the adhesion of the cured product such as the protective film to the protected object such as the substrate with wiring is improved. It is believed that in particular, when the protected object includes a film containing an imide bond, an amide bond, or an imide bond and an amide bond, the intermolecular interaction between the amine structure and the similar parts with high polarity of the imide bond or amide bond contained in the film becomes larger, and the adhesion is further improved. In addition, by containing a trifunctional amine-type epoxy resin in the thermosetting resin composition, there is a tendency to obtain a film that suppresses the generation of warpage. The more epoxy groups in one molecule of epoxy resin, the denser the epoxy resin becomes as a crosslinking point, and the easier it is to produce warpage in a cured product such as a protective film. It is believed that when the number of epoxy groups in one molecule of epoxy resin is small, it is not easy to become dense, shrinkage can be suppressed, and the warpage of the cured product becomes smaller. On the other hand, if the amine-type epoxy resin is less than 2 functional groups, the mesh structure caused by the epoxy resin cannot be introduced into the cured product. When a trifunctional amine epoxy resin is used, a network structure can be introduced into the cured product, and densification can be easily prevented.

[0113] For these reasons, it is considered that the penetration of the detergent into the interface between the cured product and the object to be protected can be suppressed, and short circuits between wirings caused by the detergent, short circuits caused by migration due to metal precipitation, etc. can be prevented.

[0114] The epoxy equivalent of the trifunctional amine epoxy resin is, for example, 70 to 120 g / eq, 80 to 115 g / eq, or 90 to 110 g / eq. If the epoxy equivalent is 120 g / eq or less, there is a tendency that the number of epoxy groups per unit mass becomes sufficient and the adhesion to the protected object is improved. In particular, when the trifunctional amine epoxy resin has a monoglycidylamino group, a diglycidylamino group, or both, it is also easy to obtain the effect of improving the adhesion brought about by the amine structure. If the epoxy equivalent is 70 g / eq or more, there is a tendency that the crosslinking points are easily prevented from becoming dense. The epoxy equivalent can be measured, for example, in accordance with JIS K7236:2001.

[0115] Commercially available products of trifunctional amine epoxy resins include, for example, "EP-3950E", "EP-3950S", and "EP-3950L" manufactured by ADEKA Co., Ltd.; "Sumi-Epoxy ELM-100" and "Sumi-Epoxy ELM-100H" manufactured by Sumitomo Chemical Co., Ltd.; and "jER630" and "jER630LSD" manufactured by Mitsubishi Chemical Co., Ltd.

[0116] The content of the trifunctional amine epoxy resin is, for example, 1 to 16 mass%, 2 to 14 mass%, 3 to 12 mass%, or 3 to 10 mass%, based on the mass of the resin A. If the content is within the above range, better detergent resistance is easily obtained. In particular, from the viewpoint of obtaining excellent detergent resistance, the content of the trifunctional amine epoxy resin may be 5 to 16 mass%, 7 to 12 mass%, or 8 to 10 mass%.

[0117] (Quadrifunctional amine epoxy resin)

[0118] The tetrafunctional amine epoxy resin may have, for example, a monoglycidylamino group, a diglycidylamino group, or both. The tetrafunctional amine epoxy resin may further have a glycidyloxy group. The tetrafunctional amine epoxy resin includes, for example, an epoxy resin represented by the following formula (E2).

[0119] [Chemical formula 7]

[0120]

[0121] (Where R 2 It represents a divalent organic group.

[0122] As R 2 Examples of R include the groups exemplified in the description of X in the diisocyanate compound represented by the above formula (P3). 2 For example, it may be an alkylene group having 1 to 20 carbon atoms; an arylene group such as a phenylene group or a naphthylene group which is unsubstituted or substituted with a lower alkyl group having 1 to 5 carbon atoms such as a methyl group, or a lower alkoxy group having 1 to 5 carbon atoms such as a methoxy group; or an organic group formed by bonding two of the above arylene groups via a lower alkylene group having 1 to 5 carbon atoms, an oxy group (-O-), a carbonyl group (-CO-), or a sulfonyl group (-SO2-). The alkylene group having 1 to 20 carbon atoms may be a linear, branched, or cyclic alkylene group, a cyclic alkylene group, or a cyclohexylene group. The above arylene group may be an unsubstituted arylene group, or an unsubstituted phenylene group. The above organic group may be an organic group formed by bonding two phenylene groups via a lower alkylene group having 1 to 5 carbon atoms, or may be a diphenylmethanediyl group (*-Ph-CH2-Ph-* (Ph is a phenylene group)).

[0123] The epoxy equivalent of the tetrafunctional amine epoxy resin is, for example, 90 to 140 g / eq, 100 to 135 g / eq, or 110 to 130 g / eq. If the epoxy equivalent is 140 g / eq or less, there is a tendency that the number of epoxy groups per unit mass becomes sufficient and the adhesion to the protected object is improved. In particular, when the tetrafunctional amine epoxy resin has a monoglycidylamino group, a diglycidylamino group, or both, it is also easy to obtain the effect of improving the adhesion due to the amine structure. If the epoxy equivalent is 90 g / eq or more, there is a tendency that the crosslinking points are easily prevented from becoming dense.

[0124] Examples of commercially available tetrafunctional amine epoxy resins include "YH-434" and "YH-434L" manufactured by NIPPON STEEL Chemical & Materia Co., Ltd.; "Sumi-Epoxy ELM-434", "Sumi-Epoxy ELM-434L", and "Sumi-Epoxy ELM-434VL" manufactured by Sumitomo Chemical Co., Ltd.; "jER604" manufactured by Mitsubishi Chemical Co., Ltd.; "TETRAD-X" and "TETRAD-C" manufactured by MITSUBISHI GAS CHEMICAL Co., Ltd.; and "TG3DAS" manufactured by Konishi Chemical Co., Ltd.

[0125] When the thermosetting resin composition further contains a tetrafunctional amine epoxy resin, the content of the tetrafunctional amine epoxy resin is, for example, 1 to 16 mass%, 2 to 10 mass%, 3 to 10 mass%, or 5 to 8 mass% based on the mass of the resin A. If the content is within the above range, better detergent resistance is easily obtained. According to another embodiment, the thermosetting resin composition does not contain a tetrafunctional amine epoxy resin, or the content of the tetrafunctional amine epoxy resin is based on the mass of the resin A, which can be less than 3 mass%, less than 2 mass%, or less than 1 mass%.

[0126] When the thermosetting resin composition contains a tetrafunctional amine epoxy resin, the total content of the trifunctional amine epoxy resin and the tetrafunctional amine epoxy resin is, for example, 3 to 28 mass %, 4 to 20 mass %, 6 to 16 mass %, or 8 to 10 mass % based on the mass of the resin A.

[0127] Sometimes, the higher the content of the trifunctional amine epoxy resin in the total of the trifunctional amine epoxy resin and the tetrafunctional amine epoxy resin, the better detergent resistance can be obtained. The content of the trifunctional amine epoxy resin is, for example, 30% by mass or more, 50% by mass or more, 80% by mass or more, or 90% by mass or more, based on the total mass of the trifunctional amine epoxy resin and the tetrafunctional amine epoxy resin. The upper limit may be 100% by mass.

[0128] (Any epoxy resin)

[0129] The thermosetting resin composition may further contain epoxy resins such as amine epoxy resins with 1, 2, or 5 or more functions, non-amine epoxy resins, etc. Examples of bifunctional amine epoxy resins include "GAN" and "GOT" manufactured by Nippon Kayaku Co., Ltd. and "EP-3980" manufactured by ADEKA Co., Ltd. Examples of the non-amine epoxy resin include bisphenol A epoxy resins (such as "Epikote 828" manufactured by Mitsubishi Chemical Co., Ltd.), bisphenol F epoxy resins (such as "YDF-170" manufactured by Nippon Steel Chemical & Materia Co., Ltd.), phenol novolac epoxy resins (such as "Epikote 152, 154" manufactured by Mitsubishi Chemical Co., Ltd.; "EPPN-201" manufactured by Nippon Kayaku Co., Ltd.; "DEN-438" manufactured by Dow Chemical Co., Ltd.), ortho-cresol novolac epoxy resins (such as "EOCN-125S, 103S, 104S" manufactured by Nippon Kayaku Co., Ltd.), heterocyclic epoxy resins (such as "ARALDITE" manufactured by Ciba Specialty Chemicals Co., Ltd.), and the like. PT810", etc.), alicyclic epoxy resins ("ERL4234, 4299, 4221, 4206", etc. manufactured by UCC), epoxy resins having a dicyclopentadiene skeleton ("HP-7200", "HP-7200H" manufactured by DIC Corporation), multifunctional epoxy resins ("Epon1031S" manufactured by Mitsubishi Chemical Co., Ltd.; "ARALDITE 0163" manufactured by Ciba Specialty Chemicals Co., Ltd.; "DENACOL EX-611, EX-614, EX-614B, EX-622, EX-512, EX-521, EX-421, EX-411, EX-321"; "PB4700" and "EHPE3150" manufactured by Daicel Co., Ltd.; "KR470" manufactured by Shin-Etsu Chemical Co., Ltd.; "BATG" manufactured by Resonac Co., Ltd.; "jER157S70" manufactured by Mitsubishi Chemical Co., Ltd., etc.)

[0130] The thermosetting resin composition may contain, for example, a multifunctional epoxy resin as any epoxy resin, and may contain a trifunctional non-amine epoxy resin or a tetrafunctional or higher-functional non-amine epoxy resin.

[0131] In the case where the thermosetting resin composition further contains a non-amine epoxy resin, the content of the non-amine epoxy resin is, for example, 1 to 20% by mass or 5 to 18% by mass based on the mass of resin A. If the content is within the above range, better detergent resistance is easily obtained. According to another embodiment, the thermosetting resin composition does not contain a non-amine epoxy resin, or the content may be less than 5% by mass, less than 3% by mass, or less than 1% by mass. With respect to the cured film obtained by the thermosetting resin composition containing a non-amine epoxy resin and a trifunctional amine epoxy resin, it is inferred that a concentration gradient is generated between the substrate side and the surface side in the cured film according to the difference in polarity, and the concentration of the trifunctional amine epoxy resin becomes higher on the substrate side.

[0132] The higher the content of the trifunctional amine-type epoxy resin in the epoxy resin, the more excellent detergent resistance tends to be obtained. The content of the trifunctional amine-type epoxy resin in the epoxy resin is, for example, 10% by mass or more, 30% by mass or more, 50% by mass or more, or 80% by mass or more, based on the total mass of the epoxy resin. The upper limit may be 100% by mass.

[0133] The total content of the epoxy resin contained in the thermosetting resin composition is, for example, 4 to 28 mass%, 5 to 20 mass%, 6 to 16 mass%, or 8 to 10 mass%, based on the mass of resin A. If the content is within the above range, it is easy to obtain a flexible printed circuit board and an electronic component with good insulation reliability, low warping and weather resistance. If the content of the trifunctional amine-type epoxy resin in the epoxy resin is high, there is a tendency to obtain good detergent resistance even when the total content of the epoxy resin contained in the thermosetting resin composition is low. The lower the total content of the epoxy resin, the more it can suppress the mixing of impurities derived from the epoxy resin into the thermosetting resin composition, and the insulation reliability of the flexible printed circuit board can be improved. As impurities derived from the epoxy resin, for example, chlorine caused by epichlorohydrin, which is a raw material of the epoxy resin, can be cited.

[0134] For example, the thermosetting resin composition contains 1 to 16% by mass of a trifunctional amine epoxy resin based on the mass of resin A. For example, the thermosetting resin composition contains 1 to 5% by mass of a trifunctional amine epoxy resin based on the mass of resin A and 3 to 10% by mass of a tetrafunctional amine epoxy resin based on the mass of resin A. For example, the thermosetting resin composition contains 1 to 5% by mass of a trifunctional amine epoxy resin based on the mass of resin A, 3 to 10% by mass of a tetrafunctional amine epoxy resin based on the mass of resin A, and 6 to 20% by mass of a non-amine epoxy resin based on the mass of resin A. The non-amine epoxy resin may be a tetrafunctional or higher epoxy resin having four or more epoxy groups.

[0135] [Organic solvents]

[0136] The thermosetting resin composition may further contain an organic solvent. Examples of the organic solvent include polar solvents such as N-methyl-2-pyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), γ-butyrolactone (GBL), 3-methoxy-N,N-dimethylpropaneamide (MPA), N,N'-dimethylformamide, N,N'-dimethylacrylurea [1,3-dimethyl-3,4,5,6-tetrahydropyrimidin-2(1H)-one], dimethyl sulfoxide, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and sulfolane; aromatic hydrocarbon solvents such as xylene and toluene; and ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone. The organic solvent preferably contains at least one selected from the group consisting of N-methyl-2-pyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), γ-butyrolactone (GBL) and 3-methoxy-N,N-dimethylpropaneamide (MPA), and more preferably contains at least one selected from the group consisting of N-ethyl-2-pyrrolidone (NEP), γ-butyrolactone (GBL) and 3-methoxy-N,N-dimethylpropaneamide (MPA).

[0137] The organic solvent may be any of the organic solvents listed as examples of organic solvents that can be used in the reaction of polyols and polyisocyanates. The organic solvent may be, for example, the same organic solvent as that used in the reaction of polyisocyanate A and tricarboxylic acid compound. In particular, from the viewpoint of defoaming, leveling and other printability and suppression of outflow (bleeding) between wirings of the thermosetting resin composition, the organic solvent may be γ-butyrolactone.

[0138] The content of the organic solvent can be appropriately determined according to the application of the thermosetting resin composition. For example, when the thermosetting resin composition is applied by screen printing, the content of the organic solvent is, for example, 20 to 100 mass %, 30 to 90 mass %, or 40 to 80 mass % based on the total mass of the thermosetting resin composition.

[0139] [Optional ingredients]

[0140] The thermosetting resin composition may further contain resins other than resins having an acid anhydride group or a carboxyl group; fillers; surfactants such as defoamers and leveling agents; colorants such as dyes and pigments; heat stabilizers, antioxidants, flame retardants, lubricants, etc. as needed.

[0141] When the thermosetting resin composition contains a filler, there is a tendency that at least any one of the increase in thixotropic coefficient, film forming property, weather resistance of the protective film, printability, etc., is improved. As the filler, inorganic fillers (inorganic fillers) and organic fillers (organic fillers) can be listed. The filler can be used alone or in combination of two or more.

[0142] Examples of inorganic fillers include silicon dioxide (SiO2), aluminum oxide (Al2O3), titanium dioxide (TiO2), tantalum oxide (Ta2O5), zirconium oxide (ZrO2), silicon nitride (Si3N4), barium titanate (BaO·TiO2), barium carbonate (BaCO3), lead titanate (PbO·TiO2), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), gallium oxide (Ga2O3), spinel (MgO·Al2O3), mullite (3Al2O3·2S iO2), dongqing stone (2MgO·2Al2O3 / 5SiO2), talc (3MgO·4SiO2·H2O), aluminum titanate (TiO2-Al2O3), zirconium oxide containing yttria (Y2O3-ZrO2), barium silicate (BaO·8SiO2), boron nitride (BN), calcium carbonate (CaCO3), calcium sulfate (CaSO4), zinc oxide (ZnO), magnesium titanate (MgO·TiO2), barium sulfate (BaSO4), carbon (C), hydrotalcite (Mg4Al2(OH) 12 CO3·3H2O) etc.

[0143] As an example of an organic filler, from the viewpoint of heat resistance and mechanical properties, microparticles of resins having amide bonds, imide bonds, ester bonds, or ether bonds can be listed. As an organic filler, for example, microparticles of polyimide resins or their precursors, polyamideimide resins or their precursors, or polyamide resins can be used.

[0144] The content of the filler is, for example, 1 to 100 mass %, 3 to 50 mass %, or 5 to 30 mass % based on the mass of the resin A. If the content is 1 mass % or more, the viscosity after curing can be suppressed, and adhesion of the film to the substrate etc. can be easily prevented. If the content is 100 mass % or less, the occurrence of warping of the cured film of the thermosetting resin composition can be easily prevented.

[0145] When the thermosetting resin composition contains a surfactant such as a defoamer or a leveling agent, the workability during film formation and the film properties before and after curing tend to be improved. The content of the surfactant is, for example, 0.1 to 5% by mass, or 0.5 to 3% by mass based on the mass of the resin A.

[0146] [Manufacturing method]

[0147] The method for producing the thermosetting resin composition is not particularly limited. For example, a method can be applied in which resin A, a trifunctional amine epoxy resin, and any components such as an organic solvent and a defoamer as required are mixed by a mixing method such as a roller mill or a mixer used in the manufacture of a common coating, ink, or paste. Each component can be added sequentially to a mixing container. Alternatively, a thermosetting resin composition kit described later can be used to add the first agent and the second agent to a mixing container.

[0148] <Kit for thermosetting resin composition>

[0149] In several embodiments, a thermosetting resin composition kit is used to obtain a thermosetting resin composition, and includes a first agent containing a resin having an anhydride group or a carboxyl group and a second agent containing a trifunctional amine-type epoxy resin. By using a thermosetting resin composition kit, each component can be stably stored. In the case of using it to obtain a thermosetting resin composition further containing any epoxy resin such as a tetrafunctional amine-type epoxy resin, the second agent can contain any epoxy resin. The first agent, the second agent, or both of them can contain any ingredients such as an organic solvent, a filler, and a defoamer. The thermosetting resin composition kit can be a kit of two agents including the first agent and the second agent, or it can also be a kit of three or more agents further including one or more agents containing at least one component selected from resin A, other resins, trifunctional amine-type epoxy resins, other epoxy resins, organic solvents, fillers, defoamers, etc.

[0150] <Cured product of thermosetting resin composition>

[0151] In several embodiments, the cured product can be obtained using the thermosetting resin composition of the above embodiment or the set for the thermosetting resin composition of the above embodiment. Examples of the cured product include cured films, films, sheets, etc. The cured products such as cured films, films, sheets, etc. can be protective films. The cured product is obtained, for example, by applying a thermosetting resin composition on a substrate to obtain a coating film and then thermally curing the coating film. The coating film can also be dried before thermal curing. The cured product can be, for example, a protective film for a flexible printed substrate; it can be a protective film for a flexible printed substrate having a copper foil and a polyimide substrate in contact with the copper foil.

[0152] Examples of coating methods include spin coating, casting, dipping, dispensing, relief printing, gravure printing, offset printing, planographic printing, relief reverse offset printing, screen printing, gravure printing, and other printing methods. The heating temperature during thermal curing is, for example, 60 to 200° C., 80 to 180° C., or 100 to 150° C. The heating time is, for example, 10 to 150 minutes, or 30 to 120 minutes.

[0153] <Flexible printed circuit boards and electronic components>

[0154] In some embodiments, the flexible printed substrate may be a flexible printed wiring board, which includes, for example, at least a substrate having a wiring pattern formed thereon, a protective film covering at least a portion of the wiring pattern, and a plating covering at least a portion of the wiring pattern. In some embodiments, the flexible printed substrate may be a flexible circuit board further including electronic components such as a flexible printed wiring board and a semiconductor device. The flexible printed substrate has excellent detergent resistance due to the protective film being a cured product of the above embodiment.

[0155] Examples of the substrate include polyimide films, polyimide films with epoxy adhesive layers, etc. The thickness of the substrate is, for example, 10 to 200 μm, or 20 to 100 μm.

[0156] The wiring pattern may be formed of a material including copper. The wiring width of the wiring pattern is, for example, 5 to 200 μm, or 10 to 100 μm. The plating layer may be formed of a material including Sn, Ni, or Au.

[0157] The manufacturing method of a flexible printed wiring board, for example, includes: preparing a substrate on which a wiring pattern is formed; printing the thermosetting resin composition of the above-mentioned embodiment in a manner covering at least a portion of the above-mentioned wiring pattern; curing the printed thermosetting resin composition to form a protective film; and forming a plating layer in a manner covering at least a portion of the above-mentioned wiring pattern.

[0158] From the viewpoint of preventing oxidation of copper or other wiring and obtaining suitable low warpage and flexibility as a protective film, the conditions for thermal curing are, for example, 80 to 180° C., 90 to 160° C., or 120 to 150° C. From the viewpoint of preventing oxidation of wiring and obtaining suitable low warpage and flexibility as a protective film, the heating time is, for example, 30 to 120 minutes, or 50 to 90 minutes.

[0159] In some embodiments, the thermosetting resin composition of the above-mentioned embodiment is suitable for use as a material for forming an outer coating material, a liquid sealant, an interlayer insulating film, a surface protective film, a solder resist layer, an adhesive layer, etc. for electronic components. As electronic components, in addition to flexible printed substrates such as COF (Chip On Film) and TAB (Tape Automated Bonding), for example, semiconductor elements such as integrated circuits, transistors, and diodes, semiconductor devices including semiconductor elements and semiconductor packages, modules, rigid printed substrates, liquid crystal displays, organic EL displays, etc., can also be listed.

[0160] Examples of embodiments of the present invention are given below, but the present invention is not limited to the following embodiments.

[0161] (1) A thermosetting resin composition comprising a resin having at least one group selected from the group consisting of an acid anhydride group and a carboxyl group, and a trifunctional amine-type epoxy resin.

[0162] (2) The thermosetting resin composition according to (1) above, wherein the trifunctional amine-type epoxy resin comprises an epoxy resin represented by the above formula (E1).

[0163] (3) The thermosetting resin composition according to (1) or (2) above, wherein the content of the trifunctional amine epoxy resin is 1 to 16% by mass based on the mass of the resin.

[0164] (4) The thermosetting resin composition according to any one of (1) to (3) above, further comprising a tetrafunctional amine-type epoxy resin.

[0165] (5) The thermosetting resin composition according to (4) above, wherein the tetrafunctional amine-type epoxy resin comprises an epoxy resin represented by the above formula (E2).

[0166] (6) The thermosetting resin composition according to (4) or (5) above, wherein the content of the tetrafunctional amine epoxy resin is 1 to 16% by mass based on the mass of the resin.

[0167] (7) The thermosetting resin composition according to any one of (1) to (6) above, further comprising an epoxy resin other than the amine-type epoxy resin.

[0168] (8) The thermosetting resin composition according to any one of (1) to (7) above, wherein the total content of the epoxy resin is 4 to 28% by mass based on the mass of the resin.

[0169] (9) The thermosetting resin composition according to any one of (1) to (8) above, wherein the resin comprises a polyamideimide having at least one group selected from the group consisting of an acid anhydride group and a carboxyl group.

[0170] (10) The thermosetting resin composition according to any one of (1) to (9) above, wherein the resin comprises a polyamideimide having at least one group selected from the group consisting of an acid anhydride group and a carboxyl group and a urethane bond.

[0171] (11) The thermosetting resin composition according to (9) or (10) above, wherein the polyamideimide includes a structure derived from the polycarbonate diol represented by the above formula (P1).

[0172] (12) The thermosetting resin composition according to any one of (9) to (11) above, wherein the polyamide-imide includes a structure represented by the formula (P2).

[0173] (13) The thermosetting resin composition according to any one of (1) to (12) above, which is used for a protective film of a flexible printed circuit board having a polyimide substrate and a copper foil in contact with the polyimide substrate.

[0174] (14) A kit for a thermosetting resin composition, which is used to obtain the thermosetting resin composition according to any one of (1) to (13) above.

[0175] The invention comprises a first agent containing the above-mentioned resin and a second agent containing the above-mentioned trifunctional amine-type epoxy resin.

[0176] (15) A cured product obtained using the thermosetting resin composition according to any one of (1) to (13) above or the kit for a thermosetting resin composition according to (14) above.

[0177] (16) A film obtained using the thermosetting resin composition according to any one of (1) to (13) above or the kit for a thermosetting resin composition according to (14) above.

[0178] (17) A flexible printed circuit board obtained by using the thermosetting resin composition according to any one of (1) to (13) above or the kit for a thermosetting resin composition according to (14) above.

[0179] (18) An electronic component obtained by using the thermosetting resin composition according to any one of (1) to (13) above or the kit for a thermosetting resin composition according to (14) above.

[0180] The disclosure of this application is related to the subject matter described in Japanese Patent Application No. 2023-116179 filed on July 14, 2023, and all the disclosed contents are incorporated herein by reference.

[0181] Example

[0182] The embodiments of the present invention will be specifically described by way of examples. However, the embodiments of the present invention are not limited to the following examples.

[0183] <Synthesis of Resin A>

[0184] The polycarbonate diol (1) (R) represented by the above formula (P1) is added to a reaction vessel equipped with a stirrer, a thermometer and a condenser. pThe structure derived from 1,4-cyclohexanedimethanol and the structure derived from 1,6-hexanediol are contained in a molar ratio of 1:1, and the average value n is in the range of 4 to 6. ) 33.63 g (0.04 mol), polycarbonate diol (2) (R) represented by the above formula (P1) p The structure derived from 1,4-cyclohexanedimethanol and the structure derived from 1,6-hexanediol are contained in a molar ratio of 3:1, and the average value n is in the range of 4 to 6. ) 111.83 g (0.12 mol) and the polycarbonate diol (3) (R) represented by the above formula (P1) p The structure is derived from 1,6-hexanediol, and the average value n is in the range of 21.5 to 23.5. )76.74g (0.04mol). Further, 4,4'-diphenylmethane diisocyanate 59.37g (0.24mol), toluene diisocyanate mixture (1) (a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate in a mass ratio of 80:20) 27.56g (0.16mol) and γ-butyrolactone 206.40g were added to the reaction container and stirred to obtain a mixture. The mixture was heated to 150°C to dissolve all the raw materials, and the reaction was performed for 4 hours to generate a polyisocyanate having a urethane bond.

[0185] Next, the temperature of the obtained reaction solution was lowered to 70°C, 55.76 g (0.29 mol) of trimellitic anhydride was added to completely dissolve it, and then 13.86 g (0.06 mol) of 4,4'-diphenylmethane diisocyanate, 6.45 g (0.04 mol) of tolylene diisocyanate mixture (1) and 170.51 g of γ-butyrolactone were added and stirred to obtain a mixture. The mixture was heated to 120°C to dissolve all the raw materials, and reacted for 1 hour.

[0186] The reaction was carried out at 160°C for 5 hours, 135°C for 1 hour, and 120°C for 1 hour while adjusting the temperature of the obtained reaction solution. Then, 5.36 g (0.06 mol) of 2-butanone oxime and 142.27 g of γ-butyrolactone were added to terminate the reaction. A polyamideimide-containing liquid having a urethane bond (solid content 40.5% by mass, hereinafter referred to as "varnish") was obtained.

[0187] The number average molecular weight (Mn) of the polyamideimide was 6,900, the weight average molecular weight (Mw) was 46,500, the degree of dispersion (Mw / Mn) was 6.72, and the acid value was 11 mgKOH / g.

[0188] The GPC measurement conditions for the number average molecular weight and weight average molecular weight of the polyamideimide and the measurement method of the acid value are shown below.

[0189] (Number average molecular weight, weight average molecular weight)

[0190] Liquid delivery pump: "LC-20AD" manufactured by Shimadzu Corporation

[0191] Automatic sampler: "SIL-20A HT" manufactured by Shimadzu Corporation

[0192] Column oven: "CTO-20A" manufactured by Shimadzu Corporation

[0193] UV detector: "SPD-M20A" manufactured by Shimadzu Corporation

[0194] Column: Gelpacks "GL-A160-S" and "GL-A150-S" manufactured by Hitachi High-Tech Co., Ltd. were connected in series.

[0195] Column size: inner diameter 7.8mm, length 300mm (GL-A160-S, GL-A150-S)

[0196] Eluent: Tetrahydrofuran (THF)

[0197] Sample concentration: Resin 10mg / THF 2.5mg

[0198] Injection volume: 20 μL

[0199] Flow rate: 1mL / min

[0200] Column temperature: 40°C

[0201] Molecular weight standard substance: Standard polystyrene (PStQuick B, PStQuick C, PStQuick D manufactured by Tosoh Corporation)

[0202] (Acid value)

[0203] 1 g of polyamide-imide was accurately weighed into a stoppered flask, and 100 g of N-methylpyrrolidone was added to dissolve it. A few drops of thymol blue reagent were added to the obtained solution as an indicator, and the solution was titrated with 0.1 mol / L potassium hydroxide aqueous solution until a brown color was present for 30 seconds, and the inflection point on the titration curve was set as the end point. As a titration apparatus, a "burette 25 mL" manufactured by AS ONE Co., Ltd. was used.

[0204] The acid value was calculated by the following formula from the amount of 0.1 mol / L potassium hydroxide aqueous solution required for titration.

[0205] Acid value = a × F × 5.611 / amount of polyamide-imide (g)

[0206] a: Amount of 0.1 mol / L potassium hydroxide aqueous solution (mL)

[0207] F: Titer of 0.1 mol / L potassium hydroxide aqueous solution

[0208] <Preparation of Thermosetting Resin Composition>

[0209] [Example 1]

[0210] The polyamide-imide varnish, epoxy resin, defoamer and solvent were added to a revolving mixer ("AR-250" manufactured by THINKY Co., Ltd.). The mixture was kneaded at a rotation speed of 2,000 rpm and a rotation time of 3 minutes to obtain a thermosetting resin composition. The content (parts by mass) of each component is shown in Table 1. The content of polyamide-imide in Table 1 is the solid content.

[0211] [Examples 1 to 10 and Comparative Examples 1 to 7]

[0212] A thermosetting resin composition was obtained in the same manner as in Example 1 except that the epoxy resin and the like were changed to the components and contents shown in Tables 1 and 2. The content of the polyamideimide in Tables 1 and 2 is the solid content.

[0213] Table 1

[0214]

[0215] Table 2

[0216]

[0217] The components used in Examples and Comparative Examples are described below.

[0218] Polyamide-imide: Polyamide-imide obtained in Synthesis Example

[0219] Epoxy resin

[0220] A: trifunctional amine-modified epoxy resin (N,N-bis(2,3-epoxypropyl)-4-(2,3-epoxypropyloxy)aniline, epoxy equivalent 95 g / eq, EP-3950S / made by ADEKA Corporation)

[0221] B: tetrafunctional amine-modified epoxy resin (N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, epoxy equivalent 117 g / eq, YH-434L / manufactured by NIPPON STEEL Chemical & Materia Co., Ltd.)

[0222] C: Multifunctional butadiene epoxy resin (epoxy equivalent 165 g / eq, PB4700 / manufactured by Daicel Corporation)

[0223] D: tetrafunctional siloxane-based epoxy resin (epoxy equivalent 200 g / eq, KR470 / manufactured by Shin-Etsu Chemical Co., Ltd.)

[0224] E: tetrafunctional bisphenol A type epoxy resin (epoxy equivalent 124 g / eq, BATG / manufactured by Resonac Co., Ltd.)

[0225] F: Multifunctional cyclohexane type epoxy resin (epoxy equivalent 180 g / eq, EHPE3150 / manufactured by Daicel Corporation)

[0226] G: Multifunctional bisphenol A type epoxy resin (epoxy equivalent 207 g / eq, jER157S70 / Mitsubishi Chemical Co., Ltd.)

[0227] Defoaming agent: acrylic defoaming agent (DISPARLON LF-1983, manufactured by Kusumoto Chemicals Co., Ltd.)

[0228] Solvent: γ-butyrolactone

[0229] <Evaluation>

[0230] A flexible copper-clad laminate was produced using the thermosetting resin composition by the following method, and the detergent resistance and low warpage properties were evaluated. The evaluation results are shown in Tables 1 and 2.

[0231] [Detergent resistance]

[0232] (Production of flexible copper-clad laminates)

[0233] A flexible copper-clad laminate (20 mm long, 27 mm wide) having a polyimide film (38 μm thick) and a comb-shaped copper wiring (wiring pattern, copper wiring width / width between copper wirings = 10.0 μm / 10.0 μm, 17 copper wiring lines) with a copper foil (sputtered copper, 8 μm thick) and a Sn plating layer (0.2-0.3 μm thick) formed on the copper foil was prepared. A thermosetting resin composition (4 mm long, 17 mm wide, 10 μm dry film thickness) was applied to the laminate by screen printing under the following conditions. The applied thermosetting resin composition was cured by heating at 80°C for 3 minutes and then at 140°C for 30 minutes to form a protective film. The laminate with the protective film formed was used as a test piece. Figure 1 and Figure 2 A schematic diagram of the test piece is shown in FIG. Figure 2 yes Figure 1 Enlarged view within the dashed line. Figure 1 and Figure 2 In the figure, 1 is a polyimide film, 2 is a wiring pattern, 3 is a protective film, and 100 is a test piece.

[0234] (Printing conditions)

[0235] Printing machine: LS-34GX manufactured by Newlong Precision Industry Co., Ltd.

[0236] Screen version: "3D250 screen version" manufactured by MURAKAMI Co., Ltd.

[0237] Printing speed: 80mm / sec

[0238] (Evaluation of detergent resistance)

[0239] A hollow cylindrical plastic (7 mm inner diameter) was attached to the test piece using a silicone adhesive ("CEMEDINE SUPER X2" manufactured by CEMEDINE Co., Ltd.) in such a way that one end of the side of the cylinder was in contact with the surface on the protective film side. A glass cleaner ("Windex SC" manufactured by Johnson (containing water, alcohol, alkanolamine, surfactant, etc.)) was added to the inside of the hollow cylindrical plastic, and a cover film (PET film) was attached to the other end of the side of the cylinder using a silicone adhesive. Figure 3 and Figure 4 A schematic diagram of a test piece in contact with a glass cleaner is shown in FIG. Figure 3 For the plan view, Figure 4 It is a three-dimensional picture. Figure 3 and Figure 4 In the figure, 1 is a polyimide film, 2 is a wiring pattern, 3 is a protective film, 11 is a hollow cylindrical plastic, 12 is a glass cleaner, 13 is a cover film, and 100 is a test piece.

[0240] A voltage of 20 V was applied to the test piece in an atmosphere of 23°C and 60% relative humidity, and the time (hours) from the start of the application until a short circuit occurred between the wirings was measured. 6 The timing of Ω is set to when a short circuit occurs between wirings.

[0241] [Low warpage]

[0242] (Production of flexible copper-clad laminates)

[0243] A flexible copper-clad laminate (48 mm in length and 35 mm in width) having a polyimide film (38 μm in thickness) and copper wiring (wiring pattern) with a copper foil (sputtered copper, 8 μm in thickness) and a Sn plating layer (0.2 to 0.3 μm in thickness) formed on the copper foil was prepared. A thermosetting resin composition (48 mm in length, 35 mm in width, and 10 μm in dry film thickness) was applied to the laminate by screen printing under the following conditions. The applied thermosetting resin composition was cured by heating at 80°C for 3 minutes and then at 140°C for 30 minutes to form a protective film. The laminate with the protective film formed was used as a test piece.

[0244] (Printing conditions)

[0245] Printing machine: LS-34GX manufactured by Newlong Precision Industry Co., Ltd.

[0246] Screen version: "SUS200 screen version" manufactured by MURAKAMI Co., Ltd.

[0247] Printing speed: 80mm / sec

[0248] (Evaluation of low warpage properties)

[0249] After curing, the test piece was left at room temperature (25° C.) for 24 hours. The test piece was placed on a flat plate with the protective film facing downward, and the distance (mm) from the flat plate to the top of the warpage of the flexible copper-clad wiring board was measured.

[0250] Explanation of symbols

[0251] 1 Polyimide film

[0252] 2 Wiring pattern

[0253] 3. Protective film

[0254] 11 Hollow cylindrical plastic

[0255] 12. Glass Cleaner

[0256] 13 Covering film

[0257] 100 test pieces

Claims

1. A thermosetting resin composition, wherein: Contains a resin having at least one group selected from the group consisting of an acid anhydride group and a carboxyl group, and a trifunctional amine-type epoxy resin.

2. The thermosetting resin composition according to claim 1, wherein The trifunctional amine-type epoxy resin includes an epoxy resin represented by the following formula (E1), In the formula, R 1 It represents a divalent organic group.

3. The thermosetting resin composition according to claim 1 or 2, wherein: The content of the trifunctional amine epoxy resin is 1 to 16% by mass based on the mass of the resin.

4. The thermosetting resin composition according to any one of claims 1 to 3, wherein It further contains a tetrafunctional amine type epoxy resin.

5. The thermosetting resin composition according to claim 4, wherein The tetrafunctional amine-type epoxy resin includes an epoxy resin represented by the following formula (E2), In the formula, R 2 It represents a divalent organic group.

6. The thermosetting resin composition according to claim 4 or 5, wherein: The content of the tetrafunctional amine epoxy resin is 1 to 16% by mass based on the mass of the resin.

7. The thermosetting resin composition according to any one of claims 1 to 6, wherein Furthermore, an epoxy resin other than the amine type epoxy resin is contained.

8. The thermosetting resin composition according to any one of claims 1 to 7, wherein The total content of the epoxy resin is 4 to 28% by mass based on the mass of the resin.

9. The thermosetting resin composition according to any one of claims 1 to 8, wherein The resin includes a polyamideimide having at least one group selected from the group consisting of an acid anhydride group and a carboxyl group.

10. The thermosetting resin composition according to any one of claims 1 to 9, wherein The resin includes a polyamideimide having at least one group selected from the group consisting of an acid anhydride group and a carboxyl group and a urethane bond.

11. The thermosetting resin composition according to claim 9 or 10, wherein: The polyamideimide includes a structure derived from a polycarbonate diol represented by the following formula (P1), In the formula, R p represents a divalent organic group having an alicyclic hydrocarbon group having 5 to 10 carbon atoms, or a divalent organic group having an aliphatic hydrocarbon group having 1 to 18 carbon atoms, wherein the divalent organic group having an aliphatic hydrocarbon group having 1 to 18 carbon atoms does not have an alicyclic hydrocarbon group, n represents a number of 1 to 30, and R p They may be the same as or different from each other.

12. The thermosetting resin composition according to any one of claims 9 to 11, wherein The polyamide-imide comprises a structure represented by the following formula (P2), In the formula, R p represents a divalent organic group having an alicyclic hydrocarbon group having 5 to 10 carbon atoms, or a divalent organic group having an aliphatic hydrocarbon group having 1 to 18 carbon atoms, wherein the divalent organic group having an aliphatic hydrocarbon group having 1 to 18 carbon atoms does not have an alicyclic hydrocarbon group, X represents a divalent organic group, n represents a number from 1 to 30, and R p They may be the same as or different from each other, and * indicates the bonding position with other structures.

13. The thermosetting resin composition according to any one of claims 1 to 12, wherein The thermosetting resin composition is used for a protective film of a flexible printed substrate having a polyimide substrate and a copper foil in contact with the polyimide substrate.

14. A kit for a thermosetting resin composition, which is used to obtain the thermosetting resin composition according to any one of claims 1 to 13, The invention comprises a first agent containing the above resin and a second agent containing the above trifunctional amine type epoxy resin. 15 . A cured product obtained by using the thermosetting resin composition according to claim 1 or the kit for a thermosetting resin composition according to claim 14 . 16 . A film obtained by using the thermosetting resin composition according to claim 1 or the kit for a thermosetting resin composition according to claim 14 . 17 . A flexible printed circuit board obtained by using the thermosetting resin composition according to claim 1 or the kit for a thermosetting resin composition according to claim 14 . 18 . An electronic component obtained by using the thermosetting resin composition according to claim 1 or the kit for a thermosetting resin composition according to claim 14 .

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