JP2013049781A - Thermosetting resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosetting resin composition that has elongation, folding resistance, flex resistance, and low warpage, and further includes hardness, wherein a cured product excellent in elasticity can be obtained.SOLUTION: The thermosetting resin composition comprises an epoxy resin (A), an inorganic compound (B) having an aspect ratio of 5.0 or larger, polyether amine (C), a liquid polyalkylene carbonate diol (D), and a blocked isocyanate (E).

Description

  The present invention relates to a thermosetting resin composition from which a cured product having excellent elasticity can be obtained. For example, the present invention relates to a thermosetting resin composition that can be applied as a solder resist or a coverlay of a flexible substrate.

  Conventionally, a curable resin composition may be used, for example, as a solder resist film for a flexible substrate. In this case, the solder resist film is required to have not only flexibility, stretchability, and low warpage, but also mechanical properties such as bending resistance and hardness.

  In addition, when using the curable resin composition as a coverlay, a high elastic modulus is required in addition to the above-described flexibility, extensibility, low warpage, bending resistance and hardness from the viewpoint of a reinforcing material. Is done.

  Therefore, in order to impart excellent mechanical properties to the solder resist film, Patent Document 1 discloses that the inorganic filler is 10 to 1200 parts by mass, the elastic modulus (MPa) is 1 to 2000, and the average with respect to 100 parts by mass of the curable resin. A curable resin composition containing 1 to 100 parts by mass of an organic filler having a particle size of 0.01 to 10 μm containing 1 to 41 of a mass ratio of inorganic filler to organic filler is disclosed.

  In order to provide a cured coating film having excellent flexibility, Patent Document 2 discloses (A) a photosensitive prepolymer having two or more unsaturated double bonds and one or more carboxyl groups in one molecule. , (B) a photopolymerization initiator, (C) a diluent, (D) an epoxy compound, (E) a polybutadiene having one or more internal epoxide groups in one molecule, and (F) a composition containing polyurethane fine particles. Has been proposed.

  However, Patent Document 1 has a problem that although it has mechanical properties such as crack resistance and hardness, a coating film excellent in flexibility and elastic modulus cannot be obtained. Further, Patent Document 2 has a problem that predetermined flexibility is obtained, but elasticity is insufficient.

JP 2009-102623 A JP 2002-293882 A

  In view of the above circumstances, an object of the present invention is to provide a thermosetting resin composition capable of obtaining a cured product having hardness and excellent elasticity while having extensibility, bending resistance, bending resistance, and low warpage. To provide things.

  An embodiment of the present invention contains (A) an epoxy resin, (B) an inorganic compound having an aspect ratio of 5.0 or more, (C) a polyether amine, (D) a liquid polyalkylene carbonate diol, and (E) a blocked isocyanate. This is a thermosetting resin composition. The “liquid polyalkylene carbonate diol” as the component (D) means a polyalkylene carbonate diol that is liquid under normal temperature and normal pressure (25 ° C., 1 atm).

  An embodiment of the present invention is a thermosetting resin composition comprising (F) a liquid urethane resin in place of the (D) liquid polyalkylene carbonate diol and the (E) blocked isocyanate. In this embodiment, (A) an epoxy resin, (B) an inorganic compound having an aspect ratio of 5.0 or more, (C) a polyetheramine, and (F) a liquid urethane resin are contained. The “liquid urethane resin” as the component (F) means a urethane resin that is liquid under normal temperature and normal pressure (25 ° C., 1 atm).

  An embodiment of the present invention is a thermosetting resin composition further comprising (F) a liquid urethane resin. In this embodiment, (A) epoxy resin, (B) inorganic compound having an aspect ratio of 5.0 or more, (C) polyether amine, (D) liquid polyalkylene carbonate diol, (E) blocked isocyanate, (F) liquid Contains urethane resin.

  An aspect of the present invention is the thermosetting resin composition, wherein the (A) epoxy resin is in a liquid state. In this embodiment, the component (A) is a liquid epoxy resin. “Liquid epoxy resin” means an epoxy resin that is liquid under normal temperature and normal pressure (25 ° C., 1 atm).

  An embodiment of the present invention is the thermosetting resin composition, wherein the (A) epoxy resin contains a 4-t-butylcatechol type epoxy resin.

  An aspect of the present invention is the thermosetting resin characterized by containing (B) an inorganic compound having an aspect ratio of 5.0 or more in an amount of 5 to 75 parts by mass with respect to 100 parts by mass of the (A) epoxy resin. It is a composition.

  The aspect of this invention is the hardened | cured material which hardened the said thermosetting resin composition.

  The aspect of this invention is a flexible substrate which has the hardened | cured material of the said thermosetting resin composition.

  According to the embodiment of the thermosetting resin composition of the present invention, by blending the above components (A) to (E) or the above components (A) to (F), elongation, bending resistance, low A cured product having elasticity, hardness, and bending resistance can be obtained without impairing warpage. Further, according to the embodiment of the thermosetting resin composition of the present invention, the liquid urethane resin is blended in place of the liquid polyalkylene carbonate diol and the blocked isocyanate, thereby impairing the stretchability, bending resistance, and low warpage. The cured product having elasticity, hardness and bending resistance can be obtained without any problems.

  According to the embodiment of the thermosetting resin composition of the present invention, an inorganic compound having an aspect ratio of 5.0 or more can be easily dispersed and blended in the thermosetting resin composition by using a liquid epoxy resin. it can. Therefore, the thermosetting resin composition of the present invention can be easily prepared. Moreover, since the compounding quantity of a solvent can be reduced by using a liquid epoxy resin, it can prevent that the thickness of the applied coating film becomes thin at the time of thermosetting, and can form a thick cured coating film.

  According to the embodiment of the thermosetting resin composition of the present invention, low warpage is improved because the epoxy resin as the component (A) contains a 4-t-butylcatechol type epoxy resin. According to the embodiment of the thermosetting resin composition of the present invention, by blending 5 to 75 parts by mass of an inorganic compound having an aspect ratio of 5.0 or more with respect to 100 parts by mass of the epoxy resin, the coating property is impaired. The elastic modulus and hardness are improved in a balanced manner.

  According to the aspect of the present invention, a cured product having elasticity, hardness and bending resistance can be obtained without impairing stretchability, bending resistance and low warpage. Moreover, according to the aspect of this invention, the flexible substrate which has a cured coating film which has elasticity, hardness, and bending resistance without impairing extensibility, bending resistance, and low curvature property is obtained.

  Next, the thermosetting resin composition of the present invention will be described. The thermosetting resin composition of the present invention comprises (A) an epoxy resin, (B) an inorganic compound having an aspect ratio of 5.0 or more, (C) a polyether amine, (D) a liquid polyalkylene carbonate diol, and (E). It contains blocked isocyanate, and each of the above components is as follows.

(A) Epoxy resin The epoxy resin is not particularly limited. For example, rubber-modified epoxy resins such as biphenyl-type epoxy resins, naphthalene-type epoxy resins, silicone-modified epoxy resins, ε-caprolactone-modified epoxy resins, glycidylamine-type polyfunctional epoxies Resin, heterocyclic polyfunctional epoxy resin, bisphenol A type epoxy resin, novolak type epoxy resin (phenol novolak type epoxy resin, o-cresol novolak type epoxy resin, p-tert-butylphenol novolak type, etc.), 4-t-butyl Catechol type epoxy resin, bisphenol F type and bisphenol S type epoxy resin obtained by reacting bisphenol F and bisphenol S with epichlorohydrin, cyclohexene oxide group, tricyclodecane oxide Group, cycloaliphatic epoxy resin having cyclopentene oxide group, triglycidyl isocyanurate having triazine ring such as tris (2,3-epoxypropyl) isocyanurate, triglycidyltris (2-hydroxyethyl) isocyanurate, dicyclo Mention may be made of pentadiene type epoxy resins and adamantane type epoxy resins.

  Among these, rubber-modified epoxy resins such as silicone-modified epoxy resins are preferable from the viewpoint of the flexibility of the cured product, and t-butylcatechol type epoxy resins are preferable from the viewpoint of preventing warpage of the cured product and obtaining low warpage. preferable.

  Examples of t-butylcatechol type epoxy resins include compounds represented by the following general formula 1

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ each independently represents hydrogen or a t-butyl group, provided that R ¹ , R ² , At least one of R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ is a t-butyl group. Of these, 4-t-butylcatechol type epoxy resin is particularly preferable. These epoxy resins may be used alone or in combination of two or more.

  The epoxy resin is preferably liquid at normal temperature and normal pressure (25 ° C., 1 atm) from the viewpoint of ease of production of the thermosetting resin composition, and a liquid having a viscosity at 25 ° C. of 90000 mPa · S or less is particularly preferable. Although the epoxy equivalent of an epoxy resin is not specifically limited, 50-1000 are preferable and 100-500 are especially preferable.

(B) Inorganic compound having an aspect ratio of 5.0 or more An inorganic compound having an aspect ratio of 5.0 or more is acicular or fibrous. By containing an inorganic compound having an aspect ratio of 5.0 or more, the cured product is given rigidity and strength, and the elastic modulus is improved. The inorganic compound having an aspect ratio of 5.0 or more is not particularly limited, and examples thereof include fibrous wollastonite, fibrous calcium silicate, glass fiber, hydrous magnesium silicate, mica, and the like, and potassium titanate whisker, Examples include whiskers such as magnesium sulfate whisker, silicon carbide whisker, calcium carbonate whisker, and zinc oxide whisker. If the lower limit of the aspect ratio is 5.0, the elastic modulus is improved. However, the lower limit of the aspect ratio is preferably 7.0 from the viewpoint of improving the hardness of the cured product in addition to the elastic modulus. In view of further improving the thickness, the lower limit of the aspect ratio is particularly preferably 8.0. Moreover, although the upper limit of an aspect ratio is not specifically limited, 30.0 is preferable from the point of the surface external appearance of hardened | cured material, and 20.0 is especially preferable from the point of manufacture ease of a thermosetting resin composition. These compounds may be used alone or in combination of two or more. The major axis of an inorganic compound having an aspect ratio of 5.0 or more is preferably from 0.1 to 100 μm, particularly preferably from 0.5 to 50 μm, from the viewpoint of dispersibility during production.

  The compounding quantity of the inorganic compound whose aspect ratio is 5.0 or more is not specifically limited. For example, the lower limit of the compounding amount of the inorganic compound having an aspect ratio of 5.0 or more is preferably 5 parts by mass with respect to 100 parts by mass of the epoxy resin from the viewpoint of surely obtaining the elasticity of the cured product. Is more preferably 10 parts by mass, and particularly preferably 15 parts by mass from the viewpoint of improving the elasticity and hardness in a balanced manner. Moreover, the upper limit of the compounding quantity of the inorganic compound whose aspect ratio is 5.0 or more is 75 mass parts from the point which prevents the coating property of a thermosetting resin composition with respect to 100 mass parts of epoxy resins. 70 parts by mass is particularly preferable from the viewpoint of reliably preventing a decrease in coatability.

(C) Polyetheramine By containing polyetheramine, heat curing is promoted, and the cured product is imparted with bending resistance and low warpage. The polyether amine is not particularly limited as long as a primary amine is bonded to the polyether skeleton. For example, a polyoxyalkylene diamine having a primary amine bonded to both ends of a linear polyether skeleton, Examples thereof include polyoxyalkylene triamines in which a primary amine is bonded to three ends of the ether skeleton. Examples of the polyether skeleton include polyethylene oxide and polypropylene oxide. Among these, a polyoxyalkylene triamine is preferable from the viewpoint of further improving the bending resistance of the cured product, and a polyoxyalkylene triamine whose polyether skeleton is polypropylene oxide is particularly preferable.

  The compounding quantity of polyether amine is not specifically limited. For example, the compounding amount of the polyetheramine is such that the active amine hydrogen equivalent of the polyetheramine is 0.05 to 1 in terms of imparting elasticity, flex resistance and low warpage to the cured product with respect to the equivalent of the epoxy resin. The ratio of 0 is preferable, and the ratio of the active amine hydrogen equivalent of the polyetheramine to 0.2 to 0.8 is particularly preferable with respect to the equivalent of the epoxy resin from the viewpoint of improving thermosetting.

(D) Liquid polyalkylene carbonate diol By containing the liquid polyalkylene carbonate diol, the bending resistance, low warpage, and hardness of the cured product are improved. Further, the liquid polyalkylene carbonate diol is excellent in compatibility with the epoxy resin as the component (A). The liquid polyalkylene carbonate diol is not particularly limited as long as it is a polyalkylene carbonate diol that is liquid at normal temperature and normal pressure (25 ° C., 1 atm), and any of them can be used. The polyalkylene carbonate diol can be produced, for example, by a transesterification reaction between an alkylene glycol and a carbonate ester. Examples of alkylene glycols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol and 1,10-decane. Examples include linear alkylene glycols such as diols, and branched alkylene glycols such as neopentyl glycol, 3-methyl-1,5-pentanediol and 2-methyl-1,8-octanediol. Examples of the carbonic acid ester used for the transesterification include dialkyl carbonates such as dimethyl carbonate and diethyl carbonate, and diphenyl carbonate.

  Among the above-mentioned liquid polyalkylene carbonate diols, those having a number average molecular weight of 500 to 2500 and a melting point of −5 ° C. or less are preferable from the viewpoint of compatibility with the epoxy resin. From the viewpoint of ease of production of the thermosetting resin composition, a liquid polyalkylene carbonate diol having a viscosity at 25 ° C. of 90000 mPa · S or less is preferable. In addition, when using a solid polyalkylene carbonate diol, the compatibility with the epoxy resin is reduced as compared with the liquid polyalkylene carbonate diol, and cannot be uniformly dispersed in the thermosetting resin composition. Coating properties and printability will be inferior.

  A polyalkylene carbonate diol obtained from a single alkylene glycol and a single or two or more carbonates may be used, or a polyalkylene carbonate diol obtained from a single carbonate and two or more alkylene glycols may be used. Good. Moreover, you may use the polyalkylene carbonate diol obtained from two or more types of alkylene glycol and two or more types of carbonate ester. Furthermore, the above polyalkylene carbonate diols may be used alone or in combination of two or more.

  The blending amount of the liquid polyalkylene carbonate diol is not particularly limited. For example, the lower limit value of the amount of the liquid polyalkylene carbonate diol is 1.0 part by mass in terms of improving the bending resistance, low warpage and hardness of the cured product with respect to 100 parts by mass of the epoxy resin. 5.0 parts by mass is preferable, and 7.0 parts by mass is particularly preferable from the viewpoint of improving the bending resistance, low warpage, and hardness of the cured product in a more balanced manner. Moreover, the upper limit of the compounding quantity of liquid polyalkylene carbonate diol is 60 mass parts from the point which prevents the fall of the elasticity of hardened | cured material with respect to 100 mass parts of epoxy resins, 50 mass parts is preferable, and hardened | cured material 45 parts by mass is particularly preferable from the viewpoint of improving the bending resistance, low warpage and hardness in a more balanced manner.

(E) Blocked isocyanate By blending blocked isocyanate, it is possible to prevent the isocyanate group from reacting with other components of the thermosetting resin composition at room temperature, so that it can be stored for a long period of time and cured. The bending resistance, low warpage and hardness can be improved. Blocked isocyanate is a reaction product obtained by addition reaction of a blocking agent to the isocyanate group of an isocyanate compound. Accordingly, the blocked isocyanate is one in which the isocyanate group is protected by the blocking agent and inactivated. By heating the blocked isocyanate at a predetermined temperature, the blocking agent is dissociated from the isocyanate group, that is, deblocked, and an active isocyanate group is regenerated.

  Examples of the isocyanate compound include isocyanates having two or more isocyanate groups in one molecule. Specifically, aliphatic isocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, 1,3,6-hexamethylene triisocyanate, isophorone diisocyanate and 4,4'-dicyclohexylmethane diisocyanate, 4, 4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, 1,5-naphthalene diisocyanate and Examples thereof include aromatic isocyanates such as 4,4-diphenyl diisocyanate, and alicyclic isocyanates such as dicycloheptane triisocyanate.

  Among the above isocyanates, hexamethylene diisocyanate trimer is preferable from the viewpoint of low warpage.

  Examples of the blocking agent include active methylene blocking agents such as ethyl acetoacetate, phenol blocking agents such as phenol, cresol and xylenol, pyrazole blocking agents such as dimethylpyrazole, methanol, ethanol, diethyl malonate, methyl lactate and Alcohol block agents such as ethyl lactate, oxime block agents such as methyl ethyl ketone oxime, diacetyl monooxime and cyclohexane oxime, mercaptan block agents such as butyl mercaptan, t-butyl mercaptan and thiophenol, and imide blocks such as succinimide Agents, amine blocking agents such as aniline and butylamine, imidazole blocking agents such as imidazole and 2-ethylimidazole, and methyleneimine and propyleneimine And the like of the imine blocking agent.

  Of the above blocking agents, dimethylpyrazole and diethyl malonate are preferred from the viewpoint of low-temperature curability.

  Blocked isocyanates can be used even if they are commercially available. For example, MF-K60B, SBN-70D, TPA-B80E, 17B-60PX, E402-B80B, E402-B80T (above, manufactured by Asahi Kasei Chemicals, trade name) ), Sumidur BL-3175, BL-4165, BL-1100, BL-1265, Death Module TPLS-2957, TPLS-2062, TPLS-2078, TPLS-2117, Desmotherm 2170, Desmotherm 2265 (above, Sumitomo Bayer Urethane Co., Ltd.) Manufactured, trade name), coronate 2512, coronate 2513, coronate 2520 (manufactured by Nippon Polyurethane Industry, trade name), B-830, B-815, B-846, B-870, B-874, B-882 (Mitsui Takeda Chemical Co., Ltd., trade name) BI7986, BI7951, BI7982, BI7960 (Bakusenden Co., Ltd., trade name), Karenz MOI-BM, Karenz MOI-BP (manufactured by Showa Denko KK, trade name) and the like. These blocked isocyanates may be used alone or in combination of two or more.

  The compounding quantity of block isocyanate is not specifically limited. For example, the lower limit of the blended amount of the blocked isocyanate is 1.0 part by mass from the viewpoint of improving the bending resistance, low warpage and hardness of the cured product with respect to 100 parts by mass of the epoxy resin, and 3.0 parts by mass. Part is preferable, and 5.0 parts by mass is particularly preferable from the viewpoint of improving the bending resistance, low warpage, and hardness of the cured product in a more balanced manner. In addition, for example, the upper limit of the blended amount of the blocked isocyanate is 60 parts by mass from the point of preventing a decrease in elasticity with respect to 100 parts by mass of the epoxy resin, and 50 parts by mass is preferable. 45 parts by mass is particularly preferable from the viewpoint of improving the low warpage and hardness in a more balanced manner.

(F) Liquid urethane resin In the present invention, in place of the above-mentioned (D) liquid polyalkylene carbonate diol and (E) blocked isocyanate, or (D) liquid polyalkylene carbonate diol and (E) liquid isocyanate resin together with blocked isocyanate May be blended. By containing a liquid urethane resin, the bending resistance, low warpage and hardness of the cured product can be improved. A liquid urethane resin will not be specifically limited if it is a urethane resin which is a liquid under normal temperature normal pressure (25 degreeC, 1 atmosphere), All can be used. The urethane resin is obtained by reacting a compound having two or more isocyanate groups in one molecule with a polyol compound having two or more hydroxyl groups in one molecule.

 Examples of the compound having two or more isocyanate groups in one molecule include hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), methylene diisocyanate (MDI), methylenebiscyclohexyl isocyanate, trimethylhexamethyl diisocyanate, hexane diisocyanate, Examples include diisocyanates such as hexamethylamine diisocyanate, methylenebiscyclohexyl isocyanate, toluene diisocyanate, 1,2-diphenylethane diisocyanate, 1,3-diphenylpropane diisocyanate, diphenylmethane diisocyanate, and dicyclohexylmethyl diisocyanate. These compounds may be used alone or in combination of two or more.

Polyol compounds having two or more hydroxyl groups in one molecule include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 1, 5-pentanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, neopentyl glycol, 1,6-hexanediol, 2,2-diethyl-1,3- C ₂ -C ₂₂ alkanediols such as propanediol, 3,3-dimethylolheptane, 2-ethyl-2-butyl-1,3-propanediol, 1,12-dodecanediol, 1,18-octadecanediol, 2-butene-1,4-diol, 2,6-dimethyl-1-octene-3,8-dioe Aliphatic diols such as alkene diols; alicyclic diols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol; glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2 , 4-dihydroxy-3-hydroxymethylpentane, 1,2,6-hexanetriol, trimethylolethane, trimethylolpropane, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy- Aliphatic triols such as 3- (hydroxymethyl) pentane and 2,2-bis (hydroxymethyl) -3-butanol; polyols having four or more hydroxyl groups such as tetramethylolmethane, pentaerythritol, dipentaerythritol and xylitol Can be mentioned. These compounds may be used alone or in combination of two or more.

  From the viewpoint of ease of production of the thermosetting resin composition, a liquid urethane resin having a viscosity at 25 ° C. of 90000 mPa · S or less is preferable.

  The compounding quantity of a liquid urethane resin is not specifically limited. For example, the lower limit of the blending amount of the liquid urethane resin is 2.0 parts by mass with respect to 100 parts by mass of the epoxy resin in terms of improving the bending resistance, low warpage and hardness of the cured product, and 6.0 parts by mass. Mass parts are preferred, and 10 parts by mass is particularly preferred from the viewpoint of improving the bending resistance, low warpage and hardness of the cured product in a more balanced manner. Further, for example, the upper limit value of the blending amount of the liquid polyurethane resin is 120 parts by mass with respect to 100 parts by mass of the epoxy resin from the viewpoint of preventing the decrease in elasticity, and 100 parts by mass is preferable. From the viewpoint of improving the low warpage and hardness in a more balanced manner, 90 parts by mass is particularly preferable.

  In addition to the above-described components, the thermosetting resin composition of the present invention may contain various additive components such as an antifoaming agent, a colorant, an organic solvent, and various additives as necessary. Can do.

  A well-known thing can be used for an antifoamer, for example, a silicone type, a hydrocarbon type, an acrylic type etc. can be mentioned. Known colorants can be used, such as carbon black, titanium oxide, phthalocyanine, anthraquinone and dioxazine blue colorants, anthraquinone, monoazo, disazo, condensed azo, benzimidazolone. And yellow colorants such as those based on isoindolinone and the like.

  The organic solvent is used for adjusting the viscosity and drying property of the thermosetting resin composition. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, isopropanol and cyclohexanol, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane. Petroleum solvents such as petroleum ether and petroleum naphtha, cellosolves such as cellosolve and butylcellosolve, carbitols such as carbitol and butylcarbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl Examples include acetates such as carbitol acetate. The amount of the organic solvent used is preferably 40 to 500 parts by mass with respect to 100 parts by mass of the epoxy resin.

  Examples of various additives include dispersants such as coupling agents such as silane, titanate, and alumina, boron trifluoride-amine complex, dicyandiamide (DICY) and its derivatives, organic acid hydrazide, and diaminomaleonitrile (DAMN). ) And derivatives thereof, guanamine and derivatives thereof, amine imide (AI) and latent curing agents such as polyamines, metal salts of acetylacetone such as acetylacetonate Zn and acetylacetonate Cr, enamines, tin octylates, quaternary sulfonium salts And thermosetting accelerators such as triphenylphosphine, imidazole, imidazolium salt and triethanolamine borate.

  The method for producing the thermosetting resin composition of the present invention described above is not limited to a specific method. For example, after blending each of the above components at a predetermined ratio, kneading such as a three-roll roll, a ball mill, and a sand mill at room temperature. It can be produced by kneading or mixing by means, or stirring means such as a super mixer or planetary mixer. Further, prior to the kneading or mixing, if necessary, preliminary kneading or premixing may be performed.

  Next, a method for using the above-described thermosetting resin composition of the present invention will be described. Here, a method for forming a solder resist film by applying the thermosetting resin composition of the present invention on a flexible substrate having a circuit pattern formed by etching a copper foil will be described as an example. On a flexible substrate having a circuit pattern formed by etching copper foil, the thermosetting resin composition produced as described above is applied to a desired thickness using a method such as screen printing or spray coating. In order to volatilize the organic solvent in the thermosetting resin composition, preliminary drying is performed at a temperature of about 60 to 80 ° C. for about 15 to 60 minutes, and the organic solvent is volatilized from the thermosetting resin composition and applied. Make the surface of the membrane tack free. Subsequently, the target solder resist film can be formed on the flexible substrate by performing post-cure for 20 to 80 minutes with a hot air circulation dryer or the like at 130 to 170 ° C.

  An electronic circuit unit is formed by soldering an electronic component to the flexible substrate covered with the solder resist film thus obtained by a jet soldering method, a reflow soldering method, or the like.

  Next, examples of the present invention will be described. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.

Examples 1-12, Comparative Examples 1-3
The components shown in Table 1 below are blended in the proportions shown in Table 1 below, mixed and dispersed at room temperature using three rolls, and used in Examples 1-12 and Comparative Examples 1-3. A curable resin composition was prepared. The numbers in the formulation in Table 1 below indicate parts by mass.

Details of each component in Table 1 are as follows.
(A) Epoxy resin / TSR-960: manufactured by DIC, solvent-free rubber-modified epoxy resin (liquid at normal temperature and pressure), epoxy equivalent = 240
Epicron HP-820: DIC, 4-t-butylcatechol type epoxy resin (liquid at room temperature and normal pressure), epoxy equivalent = 230
(B) Inorganic compound having an aspect ratio of 5.0 or more: SH-1800: manufactured by Kinsei Matech Co., Ltd., fibrous wollastonite, aspect ratio of 8, average particle diameter (minor axis) of 3.5 μm
・ Milcon SP-2: manufactured by Showa KDE Co., Ltd., hydrous magnesium silicate, aspect ratio of 5.0 or more ・ Panatetra WZ-05F1: manufactured by Amtec Co., Ltd., zinc oxide, aspect ratio of 10, average particle diameter (minor axis) 0 .2 to 3.0 μm
(C) Polyetheramine T403: manufactured by Mitsui Chemicals Fine Chemicals Co., Ltd., polyoxyalkylenetriamine whose polyether skeleton is polypropylene oxide, viscosity 70 to 382 mPa · s at 25 ° C., active amine hydrogen equivalent = 160
(D) Liquid polyalkylene carbonate diol • DURANOL T5652: Asahi Kasei Chemicals Corporation, HO [(CH ₂ ) _m1 OC (═O) O] _n (CH ₂ ) _m2 OH (where m1 = 5 or 6, m2 = 5 or 6, n = integer of 10-20)) and a number average molecular weight of about 2000
(E) Block isocyanate / BI7982: manufactured by Baxenden Co., Ltd., isocyanate type is hexamethylene diisocyanate trimer, blocking agent is dimethylpyrazole. : Vaxenden Co., Ltd., viscosity at 25 ° C. 80000 ± 20000 mPa · s

About other components C.I. I. Pigment Orange 5: Ciba Specialty Chemicals, Chromophthal DPP Orange TR
Pigment Blue 15: Toyo Ink Co., Ltd., Lionol Blue FG7351
BYK310: BYK Chemie Co., Ltd., solvent-type antifoaming agent R-974: Nippon Aerosil Co., Ltd. thixotropic agent C11Z: Shikoku Kasei Co., Ltd., epoxy curing agent

  Bisaniline M is an aromatic amine, and is 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, active amine hydrogen equivalent = 86, manufactured by Mitsui Chemicals Fine Chemicals.

Test piece preparation process 1
This is a test piece preparation process for evaluating the elastic modulus and elongation rate. The thermosetting resin composition prepared as described above is uniformly applied to a PET film using a bar coater so that the thickness is 50 μm ± 10 μm. After the coating, preliminary drying was performed in a BOX furnace at 80 ° C. for 20 minutes (BOX furnace 25 minutes). A test to evaluate the elastic modulus and elongation rate after pre-drying to obtain a cured coating film by heat curing in a BOX furnace at 150 ° C. for 60 minutes (70 minutes in the BOX furnace). Created a piece.

Test piece preparation process 2
This is a test piece preparation process for evaluating bending resistance, bending resistance, warpage, and coating film hardness. A copper film is applied to a polyimide film having a thickness of 25 μm (“Kapton 100H” manufactured by Toray DuPont Co., Ltd.). About the flexible substrate provided with the circuit pattern, after surface treatment with 3% sulfuric acid aqueous solution, the thermosetting resin composition prepared as described above was applied by screen printing so that the DRY film thickness was 20 to 23 μm, In a BOX furnace, cure at 150 ° C. for 60 minutes (70 minutes in the BOX furnace) and thermally cure to obtain a cured coating film, and evaluate bending resistance, bending resistance, warpage, and coating film hardness A test piece was prepared for this purpose.

Evaluation (1) Elastic modulus (GPa)
About the test piece prepared in the test piece preparation step 1, the cured film is peeled off from the PET film and cut to a predetermined size, and an autograph (manufactured by SHIMAZU) is used and the pulling speed is 5 mm / min. The elastic modulus was measured at
(2) Growth rate (%)
Using the same sample as that prepared for the above elastic modulus measurement, the elongation was measured using an autograph (manufactured by SHIMAZU) under the condition of a pulling speed of 5 mm / min.
(3) Bending resistance The test piece prepared in the test piece preparation step 2 was subjected to 180 ° bending by goblet folding several times, and the occurrence of cracks in the cured coating film during 180 ° bending was observed visually and × 200. Were observed with an optical microscope, and the number of times cracks did not occur was measured.
(4) Bending resistance About the cured coating film after curing of the test piece prepared in the test piece preparation step 2, the bending resistance of the cured coating film was visually observed and observed with an optical microscope of × 200 by a cylindrical mandrel method. ◎: No abnormality at a diameter of 1 to 2 mm, ○: No abnormality at a diameter of 3 mm, but abnormalities such as cracks and peeling at a diameter of 2 mm, △: No abnormality at a diameter of 5 mm, but cracks at a diameter of 3 mm, The evaluation was made in four stages, ie, there was an abnormality such as peeling, and x: there was an abnormality such as cracking and peeling at a diameter of 5 mm.
(5) Warpage property After cutting out the test piece prepared in the test piece preparation step 2 to 3 cm × 3 cm, place the test piece gently on a horizontal table so that the top is concave, and do not apply any external force. Then, the vertical distance between the four corners of the test piece and the table was measured to a unit of 1 mm with a straight scale, and the maximum value was taken as the amount of warpage. As for the measurement results, the amount of warpage of 1 mm or less is “◎”, the amount of warpage of 1 mm or more and 3 mm or less is “◯”, the amount of warpage of 3 mm or more and 5 mm or less is “Δ”, and the amount of warpage of 5 mm or more is “X”. Evaluation was made in 4 stages.
(6) Film hardness According to the test method of JIS K-5600-5-4, a pencil of B to 9H, which has been sharpened so that the tip of the core is flattened, is about 45 ° on the cured film on the copper foil. The hardness of the pencil at which the cured coating film did not peel off was recorded.

The evaluation results are shown in Table 2.

  As shown in Table 2 above, in Examples 1 to 12 containing an inorganic compound having an aspect ratio of 5.0 or more and a polyetheramine, the elastic modulus is 1.5 GPa or more, the warpage is ◯ or more, and the bending resistance is high. And also had bending resistance. Therefore, in Examples 1-12, the cured coating film which was excellent in elasticity, the low curvature property, and has a softness | flexibility was able to be obtained. Moreover, in Examples 1-12, coating-film hardness was H or more and elongation rate was 2.0% or more, and coating-film hardness and extensibility were not impaired. In addition, from Examples 1, 2 and 11, the addition of 4-t-butylcatechol type epoxy resin as the epoxy resin further improved the elastic modulus, bending resistance, and low warpage. From Examples 1 to 11 and Example 12, when an inorganic compound having an aspect ratio of 5.0 or more was blended in excess of 5 parts by mass with respect to 100 parts by mass of the epoxy resin, the elastic modulus was further improved. Further, from Example 9, a cured coating film having equivalent characteristics was obtained even when a liquid urethane resin was blended in place of the liquid polyalkylene carbonate diol and the blocked isocyanate.

  On the other hand, Comparative Examples 1 and 2 not containing an inorganic compound or polyether amine having an aspect ratio of 5.0 or more are inferior in elasticity, and in Example 3 in which an aromatic amine is blended instead of polyether amine, flexibility is obtained. Inferior to low warpage.

  Since the thermosetting resin composition of the present invention has a stretch property, a bending resistance, a bending resistance, a low warping property, has a hardness, and can further obtain a cured product having excellent elasticity. Useful as a solder resist film and coverlay for wiring boards and flexible wiring boards.

Claims (8)

  A heat characterized by containing (A) an epoxy resin, (B) an inorganic compound having an aspect ratio of 5.0 or more, (C) a polyetheramine, (D) a liquid polyalkylene carbonate diol, and (E) a blocked isocyanate. Curable resin composition.   The thermosetting resin composition according to claim 1, further comprising (F) a liquid urethane resin instead of the (D) liquid polyalkylene carbonate diol and the (E) blocked isocyanate.   Furthermore, (F) liquid urethane resin is contained, The thermosetting resin composition of Claim 1 characterized by the above-mentioned.   The thermosetting resin composition according to claim 1, wherein the (A) epoxy resin is liquid.   The thermosetting resin composition according to claim 1 or 4, wherein the (A) epoxy resin contains a 4-t-butylcatechol type epoxy resin.   2. The thermosetting resin according to claim 1, wherein (B) the inorganic compound having an aspect ratio of 5.0 or more is contained in an amount of 5 to 75 parts by mass with respect to 100 parts by mass of the (A) epoxy resin. Composition.   Hardened | cured material which hardened the thermosetting resin composition of any one of Claims 1 thru | or 6.   The flexible substrate which has a hardened | cured material of the thermosetting resin composition of any one of Claims 1 thru | or 6.