WO2020080345A1

WO2020080345A1 - Curable resin composition, cured film, substrate having cured film, and production method therefor

Info

Publication number: WO2020080345A1
Application number: PCT/JP2019/040418
Authority: WO
Inventors: 雅善木戸; 哲哉小木曽; 友洋好田; 勇志朝比奈
Original assignee: 株式会社カネカ
Priority date: 2018-10-17
Filing date: 2019-10-15
Publication date: 2020-04-23
Also published as: TW202024256A; JP2022017603A

Abstract

This curable resin composition is a photocurable, thermosetting resin composition having photocurability and thermosettability. This curable resin composition contains: (A) a thermosetting resin; (B) a polymer that has an acidic functional group and an ethylenically unsaturated group; (C) a polymer that has an acidic functional group and does not have an ethylenically unsaturated group; (D) a compound that has an ethylenically unsaturated group; and (E) a photoinitiator. With respect to 100 parts by mass of the (A) component, (B) component, (C) component, and (D) component in total, the (A) component content is preferably 10-50 parts by mass, the total (B) component and (C) component content is preferably 40-85 parts by mass, and the (C) component content is preferably 25 parts by mass or more.

Description

Curable resin composition, cured film, substrate with cured film, and method for producing the same

The present invention relates to a curable resin composition having thermosetting property and photocurable property, and a cured film composed of a cured product of the curable resin composition. Furthermore, the present invention relates to a substrate with a cured film provided with a cured film on a substrate such as a printed circuit board and a method for manufacturing the same.

An insulating cured film (cover coat) is provided on the surface of the flexible printed circuit board (FPC). As the cover coat material, a photosensitive solder resist or a photosensitive dry film resist which can be finely processed by photolithography is generally used. Since the crosslink density of the photosensitive cover coat material is increased by photo-curing, the cured film has excellent heat resistance and chemical resistance, but has poor flexibility such as flexibility. Therefore, for devices such as foldable devices that require partial flexibility and flexibility, use a photosensitive material that can be patterned by photolithography in the mounting area where fine processing of the cover coat material is required. A thermosetting cover coat material or a cover lay film is used in a portion where flexibility is required.

The method of using different types of cover coat materials requires a lot of man-hours and increases the manufacturing cost. Patent Document 1 proposes to use a resin composition containing two kinds of curable resin components having different curing characteristics and to adopt different curing methods for a mounting portion and a bending portion.

JP, 2013-21067, A

In the conventional curable resin composition, the heat resistance of the mounting part may be insufficient and the flexibility of the bending part may be insufficient only by changing the curing method of the mounting part and the bending part. . In view of such a problem, the present invention has an object to provide a curable resin composition capable of achieving both heat resistance and flexibility only by changing the curing method.

The curable resin composition of the present invention is a photocurable / thermosetting resin composition having photocurability and thermosetting property. (A) Thermosetting resin; (B) Acidic functional group and ethylenic Containing a polymer having a saturated group; (C) a polymer having an acidic functional group and not having an ethylenically unsaturated group; (D) a compound having an ethylenically unsaturated group; and (E) a photopolymerization initiator. To do. The curable resin composition may further contain an organic filler.

The content of the component (A) is preferably 10 to 50 parts by weight based on 100 parts by weight of the total of the components (A), (B), (C) and (D), and the components (B) and ( The total content of component C) is preferably 40 to 85 parts by weight, and the content of component (C) is preferably 25 parts by weight or more. The content of the component (D) is preferably 5 to 30 parts by weight.

The content of the component (A) in the total solid content of the curable resin composition is preferably 10 to 50% by weight, and the total content of the components (B) and (C) is preferably 40 to 85% by weight, The content of the component (C) is preferably 20 parts by weight or more. The content of the component (D) is preferably 5 to 30% by weight.

Epoxy resin is preferable as the component (A), and polyfunctional epoxy resin is particularly preferable. The acidic functional groups of the components (B) and (C) are preferably carboxy groups. The acid value of the components (B) and (C) is, for example, about 5 to 200 mgKOH / g. The weight average molecular weights of the component (B) and the component (C) are preferably 1,000 to 1,000,000.

The component (D) preferably does not contain an acidic functional group (for example, a carboxy group) capable of reacting with the component (A). The component (D) may have 4 or more ethylenically unsaturated groups in one molecule, and the functional group equivalent of the ethylenically unsaturated groups may be 300 or less.

By applying the above-mentioned curable resin composition onto a substrate and performing light curing and / or heat curing, a substrate with a cured film having a cured film on the substrate can be obtained. The substrate on which the cured film is formed may be a flexible printed circuit board.

The curable resin composition described above can be used to produce a substrate with a cured film, which comprises a thermosetting film and a photocurable film on one substrate. For example, on the first region of the substrate, a curable resin composition is applied to form a first coating film, and the first coating film is exposed to light to be photocured, and the second region of the substrate is curable. A resin composition is applied to form a second coating film, and the second coating film is heated and thermoset to provide a photocurable film on the first region and a thermosetting film on the second region. A cured film-coated substrate is obtained.

It is also possible to form a patterned photo-cured film by performing pattern exposure using a mask when exposing the first coating film, developing after the exposure, and removing the coating film in the unexposed portion. . You may form a photothermosetting film by heating a photocuring film and thermosetting.

Either the formation of the photo-cured film or the formation of the thermo-cured film on the substrate may be performed first, or both may be performed in parallel. When forming a thermosetting film first, after forming a coating film on the second region and heat curing, form a coating film on the first region, perform exposure and, if necessary, develop, and further The photo-curable film may be thermally cured according to the above. When the photo-cured film is formed first, a coating film is formed in the first region, and after exposure and development as necessary, a coating film is formed in the second region and heat-cured by heating. Good. At this time, the photo-cured film on one region may be heat-cured at the same time as the heat-curing of the coating film on the second region.

The photosensitive resin composition of the present invention can be applied to both formation of a thermosetting film having excellent flexibility and formation of a photocuring film having excellent patterning properties. Therefore, it is possible to form a substrate with a cured film including a thermosetting film and a photocurable film on a substrate using one resin composition.

FIG. 6 is a plan view of a flexible printed wiring board having a mounting portion and a bent portion. It is a schematic cross section which shows the flow of the formation process of the substrate with a cured film. It is a schematic cross section which shows the flow of the formation process of the substrate with a cured film.

[Components of curable resin composition]
The curable resin composition of the present invention comprises (A) a thermosetting resin, (B) a polymer having an acidic functional group and an ethylenically unsaturated group, (C) an acidic functional group and an ethylenically unsaturated group. Which does not contain a polymer, (D) a photocurable compound having an ethylenically unsaturated group, and (E) a photopolymerization initiator. It has (photosensitivity).

<(A) Thermosetting resin>
The thermosetting resin is a compound having at least one thermosetting functional group in the molecule. Examples of the thermosetting resin include epoxy resin, oxetane resin, isocyanate resin, blocked isocyanate resin, bismaleimide resin, bisallylnadiimide resin, polyester resin (for example, unsaturated polyester resin), diallyl phthalate resin, silicon resin, vinyl ester. Resin, melamine resin, polybismaleimide triazine resin (BT resin), cyanate resin (for example, cyanate ester resin), urea resin, guanamine resin, sulfamide resin, aniline resin, polyurea resin, thiourethane resin, polyazomethine resin, episulfide resin , Ene-thiol resin, benzoxazine resin and the like. Of these, epoxy resins are preferable because they can react with the acidic functional groups of the components (B) and (C) described below to form a thermally crosslinked network. A polyfunctional epoxy resin having two or more epoxy groups in one molecule is preferable because it can impart heat resistance to the cured film and can impart adhesiveness to a conductor such as a metal foil or a circuit board.

As the polyfunctional epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, hydrogenated bisphenol A type epoxy resin, biphenyl type epoxy resin, phenoxy type epoxy resin, naphthalene type epoxy resin, phenol novolac Type epoxy resin, cresol novolac type epoxy resin, trisphenolmethane type epoxy resin, dicyclopentadiene type epoxy resin, amine type epoxy resin and the like. The epoxy resin may be a modified epoxy resin with urethane, rubber, chelate, dimer acid or the like. As the component (A), a commercially available epoxy resin may be used as it is.

From the viewpoint of heat resistance and chemical resistance of the cured film, the epoxy equivalent of the epoxy resin (mass (g) of the compound containing 1 equivalent of epoxy group) is preferably 2000 or less, and more preferably 1500 or less. The weight average molecular weight of the epoxy resin is preferably about 150 to 2000, more preferably about 200 to 1500.

<Polymer containing acidic functional group>
The component (B) and the component (C) are polymers having at least one acidic functional group in the molecule, and these polymers are the main components for forming a coating film with the resin composition. The acidic functional group-containing polymer is soluble in an organic solvent. Examples of the organic solvent capable of dissolving the component (B) and the component (C) include sulfoxides, formamides, acetamides, pyrrolidones, phosphoramides, lactones, ethers, acetates and the like. The components (B) and (C) are preferably those which can be dissolved in any of these organic solvents at a concentration of 5% by weight or more.

The weight average molecular weight of the acidic functional group-containing polymer in terms of polyethylene glycol is preferably 1,000 to 1,000,000, more preferably 2,000 to 200,000, further preferably 3,000 to 100,000, 000 to 50,000 is particularly preferable. When the weight average molecular weight of the acidic functional group-containing compound is within the above range, a cured film having excellent heat resistance and flexibility can be easily obtained.

Examples of the acidic functional group include a carboxy group, a phenolic hydroxyl group, a sulfonic acid group and the like. Particularly, a carboxy group is preferable from the viewpoint of reactivity with (A) thermosetting resin and storage stability. The carboxy groups of the components (B) and (C) may be carboxylic acid anhydrides in which two carboxy groups are dehydrated. Since the resin composition contains the acidic functional group-containing polymer as the component (B) and the component (C), the photosensitive resin composition before curing, which is neither heat-cured nor photocured, is alkali-soluble. On the other hand, since the component (B) and the component (C) react with the component (A) by thermosetting, the thermosetting film becomes insoluble in alkali.

The component (B) and component (C) preferably have an acid value of 5 to 200 mgKOH / g, more preferably 10 to 150 mgKOH / g, and even more preferably 15 to 100 mgKOH / g. When the acid value of the polymer is within the above range, the resin composition before curing exhibits appropriate alkali solubility. Further, when the acid value is in the above range, the heat resistance, insulation reliability and chemical resistance of the cured film can be improved, and the flexibility tends to be improved.

<(B) Polymer Having Acidic Functional Group and Ethylenically Unsaturated Group>
The component (B) is one having an ethylenically unsaturated group in the above-mentioned acidic group-containing polymer. Examples of the ethylenically unsaturated group include (meth) acryloyl group and vinyl group. The component (B) participates in heat curing by the reaction with the component (A), and the ethylenically unsaturated group participates in photocuring together with the component (D) described below. That is, since the component (B) participates in both photo-curing and heat-curing, a cured film that has undergone both photo-curing and heat-curing has an increased cross-linking density of the cured film and also has high heat resistance and chemical resistance. Tends to improve.

As the component (B), an acid-modified epoxy (meth) acrylate obtained by adding a saturated or unsaturated polycarboxylic acid anhydride to an ester obtained by reacting an epoxy resin with an unsaturated monocarboxylic acid; Urethane (meth) acrylate, which is a polymer of a diol compound having an ethylenically unsaturated group and / or a carboxy group, and a diisocyanate compound; (meth) acrylic acid having a carboxy group and a polymerizable double bond, and (meth) (Meth) acrylate obtained by reacting a part of the carboxy group of the side chain of a copolymer with an acrylic ester or the like with a (meth) acrylic group such as glycidyl (meth) acrylate and an epoxy group of a compound having an epoxy group (Meth) acrylate etc. are mentioned.

Examples of commercially available epoxy (meth) acrylates having a carboxy group include KAYARAD ZFR series, ZAR series, ZCR series, CCR series, PCR series, and UXE series manufactured by Nippon Kayaku. Examples of commercially available urethane (meth) acrylates having a carboxy group include UX series manufactured by Nippon Kayaku. Examples of commercially available (meth) acrylated (meth) acrylates include Cyclomer ACA series manufactured by Daicel Cytec.

<(C) Polymer Having Acidic Functional Group and No Ethylenically Unsaturated Group>
The component (C) is a polymer having no ethylenically unsaturated group in the above-mentioned acidic group-containing polymer. The component (C) participates in heat curing by the reaction with the component (A), but does not participate in photocuring because it does not have an ethylenically unsaturated group. By including the component (C), the flexibility of the cured film can be secured.

Specific examples of the component (C) include carboxyl group-containing (meth) acrylic polymers, carboxyl group-containing vinyl polymers, acid-modified polyurethanes, acid-modified polyesters, acid-modified polycarbonates, acid-modified polyamides, acid-modified polyimides, acid-modified polyurethanes. Examples thereof include amide and acid-modified polyurethane imide. From the viewpoint of flexibility and chemical resistance of the cured film, a carboxyl group-containing (meth) acrylic copolymer, an acid-modified polyurethane, an acid-modified polyamide, and an acid-modified polyimide are preferable.

A carboxy group-containing (meth) acrylic polymer is a copolymer containing a (meth) acrylic acid ester and a compound having a carboxy group and a polymerizable double bond in one molecule as a monomer component. Carboxy group-containing monomers include (meth) acrylic acid, crotonic acid, isocrotonic acid, myristoleic acid, palmitoleic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, eicosenoic acid, erucic acid, nervonic acid, ω-carboxyl. -Polycaprolactone mono (meth) acrylate, monohydroxyethyl (meth) acrylate phthalate, (meth) acrylic acid dimer, 2- (meth) acryloyloxypropyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl amber Acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, atropic acid, cinnamic acid, linoleic acid, eicosadienoic acid, docosadienoic acid, linolenic acid, pinolenic acid, eleostearic acid, mead acid, dihomo-Y-linolenic acid , Eicosatrienoic acid, steer Donoic acid, arachidonic acid, eicosatetraenoic acid, adrenic acid, boseopentaenoic acid, eicosapentaenoic acid, ozbondic acid, sardonic acid, tetracosapentaenoic acid, docosahexaenoic acid, nisinic acid, 2,2,2-tris (meth) Examples thereof include acryloyloxymethylsuccinic acid and 2-tris (meth) acryloyloxymethylethylphthalic acid. As the (meth) acrylic acid ester, a (meth) acrylic acid alkyl ester is preferable.

The carboxy group-containing (meth) acrylic polymer is, in addition to the carboxy group-containing monomer and the (meth) acrylic acid ester, as a copolymerization component, (meth) acrylamide such as diacetone (meth) acrylamide, acrylonitrile and vinyl-n-butyl ether. And the like, esters of vinyl alcohol, styrene, vinyltoluene and the like may be contained. The carboxy group-containing (meth) acrylic polymer is obtained, for example, by radical polymerization of the above monomer component. The radical polymerization may be thermal polymerization or photopolymerization. A polymerization initiator may be used for radical polymerization. The carboxy group-containing (meth) acrylic polymer is preferably obtained by solution polymerization using an azo compound, an organic peroxide, a persulfate, hydrogen peroxide or the like as a thermal polymerization initiator.

The acid-modified polyurethane can be obtained, for example, by reacting a diisocyanate compound with a diol compound having two hydroxyl groups and one carboxy group.

The acid-modified polyester can be obtained, for example, by reacting a dicarboxylic acid with a diol compound containing two hydroxyl groups and one carboxy group.

The acid-modified polyamide is a compound having an amic acid structure, and is obtained, for example, by reacting a diamino compound with a tetracarboxylic acid dianhydride.

The acid-modified polyimide is obtained, for example, by reacting a diisocyanate compound with a tetracarboxylic acid dianhydride. An imide compound having a carboxylic acid anhydride group at the terminal is obtained by adding tetracarboxylic dianhydride in excess of the equivalent amount of the diisocyanate compound. By reacting an imide compound having a carboxylic acid anhydride group at a terminal with water and / or a primary alcohol such as methanol, ethanol, propanol, butanol, an imide compound having a carboxy group at a terminal can be obtained.

Examples of the diol compound having two hydroxyl groups and one carboxy group include 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (2-hydroxyethyl) propionic acid and 2,2-bis (3- Hydroxypropyl) propionic acid, 2,3-dihydroxy-2-methylpropionic acid, 2,2-bis (hydroxymethyl) butanoic acid, 2,2-bis (2-hydroxyethyl) butanoic acid, 2,2-bis Aliphatic diols such as (3-hydroxypropyl) butanoic acid, 2,3-dihydroxybutanoic acid, 2,4-dihydroxy-3,3-dimethylbutanoic acid, and 2,3-dihydroxyhexadecanoic acid; 2,3- Dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3 4-dihydroxybenzoic acid, aromatic diols such as 3,5-dihydroxybenzoic acid. In particular, when an aliphatic diol is used, the resin composition tends to have excellent photosensitivity.

The diisocyanate compound may be either an alicyclic diisocyanate compound or an aliphatic diisocyanate compound. The diisocyanate compound may be a reaction product of a compound having two or more functional groups capable of reacting with the isocyanate group of the diisocyanate compound, and may be, for example, a urethane compound having an isocyanate group at the terminal.

The tetracarboxylic acid dianhydride may be either an aromatic tetracarboxylic acid dianhydride or an aliphatic tetracarboxylic acid dianhydride, and an aromatic tetracarboxylic acid dianhydride in which a carboxylic acid anhydride group is directly bonded to an aromatic ring. Anhydrous is preferred. Of these, aromatic tetracarboxylic acid dianhydrides are preferable, and those in which an anhydrous carboxy group is directly bonded to an aromatic ring are preferable. The diamino compound may be either an aromatic diamine or an aliphatic diamine, and the aromatic diamine is preferable.

<(D) Photocurable compound>
The component (D) is a photocurable compound having at least one ethylenically unsaturated group, and participates in photocuring together with the component (C). It is preferable that the component (D) participates only in photo-curing and not in heat-curing. That is, it is preferable that the component (D) does not contain an acidic functional group such as a carboxy group. When the component (D) does not participate in the thermosetting, the component (D) remains unreacted in the thermosetting film which is not subjected to photocuring but only thermosetting, and acts as a plasticizer. The tendency to improve the sex.

(Examples of the ethylenically unsaturated group include a (meth) acryloyl group and a vinyl group. From the viewpoint of increasing the curing density of the photocured film, the component (D) is preferably a compound having two or more ethylenically unsaturated groups in one molecule.

As the polyfunctional (meth) acrylate having two or more (meth) acryloyl groups in one molecule, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene Glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 2-hydroxy-1- (meth) Acryloxy-3- (meth) acryloxypropane, 1,4-butanediol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acr Rate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, 2,4-diethyl-1,5-pentanediol di (meth) acrylate, 2- Hydroxy-1,3-di (meth) acryloxypropane, 3-methyl-1,5-pentanediol di (meth) acrylate, 2,4-diethyl-1,5-pentanediol di (meth) acrylate, 1, 4-cyclohexanedimethanol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 4,4'-isopropylidene diphenol di (meth) acrylate, 2,2-bis [4-((meth) acrylate] Acryloxyethoxy) phenyl] propane, 2,2-bis [4-((meth) a) Riloxy / diethoxy) phenyl] propane, 2,2-bis [4-((meth) acryloxy / polyethoxy) phenyl] propane, 2,2-hydrogenated bis [4-((meth) acryloxy / polyethoxy) phenyl] propane, 2,2-bis [4-((meth) acryloxy / polypropoxy) phenyl] propane, bisphenol F EO modified (n = 2 to 50) di (meth) acrylate, bisphenol A EO modified (n = 2 to 50) di Bifunctional (meth) acrylates such as (meth) acrylate, bisphenol S EO-modified (n = 2 to 50) di (meth) acrylate; trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ethoxylated Totimethylolpropane tri (meth) acrylate, propoxy Trifunctional (meth) acrylates such as oxytotimethylolpropane tri (meth) acrylate, isocyanuric acid tri (ethane (meth) acrylate), and 1,3,5-tri (meth) acryloylhexahydro-s-triazine; tetramethylol Methane tetra (meth) acrylate, pentathritol tetra (meth) acrylate, ethoxylated pentathritol tetra (meth) acrylate, propoxylated pentathritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol Hexa (meth) acrylate, dipentaerythritol poly (meth) acrylate, and other tetrafunctional or higher functional (meth) acrylates may be mentioned.

Specific examples of the compound having two or more vinyl groups in one molecule include diallylamine, diallyldimethylsilane, diallyl disulfide, diallyl ether, diallyl cyanurate, diallyl isophthalate, diallyl terephthalate and 1,3-dialyloxy-2-. Propanol, diallyl sulfide diallyl maleate, triallyl isocyanurate, triallyl 1,3,5-benzenecarboxylate, triallylamine, triallyl citrate, triallyl phosphate and the like can be mentioned.

The component (D) may be a polymer (oligomer) such as urethane (meth) acrylate resin, epoxy (meth) acrylate resin, polyester (meth) acrylate resin, and acrylic (meth) acrylate resin.

From the viewpoint of increasing the crosslink density of the photo-cured film and improving heat resistance and chemical resistance, the component (D) is preferably a low molecular weight compound having a molecular weight of less than 1000, and the functional group equivalent of the component (D) ( The mass (g) of the compound containing 1 equivalent of an ethylenically unsaturated group is preferably 300 or less, more preferably 250 or less, and further preferably 200 or less. The functional group equivalent of the component (D) may be 180 or less or 150 or less. The functional group equivalent of the component (D) may be 50 or more, or 80 or more. The component (D) preferably has 4 or more ethylenically unsaturated groups in one molecule, and tetrafunctional or higher (meth) acrylate is particularly preferable. As the component (D), a compound having four or more functional groups and a compound having less than four functional groups may be used in combination.

<(E) Photopolymerization initiator>
The photopolymerization initiator as the component (E) absorbs and activates light energy such as UV (ultraviolet light) and is activated by a photoradical polymerization reaction of the ethylenically unsaturated group of the components (B) and (D). It is a compound (photoradical polymerization initiator) that initiates / promotes the formation of a photocrosslinking network.

Examples of the photoradical polymerization initiator include self-cleaving photoradical polymerization initiators such as benzoin compounds, acetophenones, aminoketones, oxime esters, acylphosphine oxide compounds, and azo compounds; and benzophenones and benzoins. Hydrogen abstraction type photoradicals of ethers, benzyl ketals, dibenzosuberones, anthraquinones, xanthones, thioxanthones, halogenoacetophenones, dialkoxyacetophenones, hydroxyacetophenones, halogenobisimidazoles, halogenotriazines, etc. A polymerization initiator may be used. The photopolymerization initiator may be used as a mixture of two or more kinds.

<(F) Filler>
The curable resin composition may contain a filler, if necessary, in addition to the components (A) to (E). Examples of the fillers include inorganic fillers such as silica, mica, talc, barium sulfate, wollastonite and calcium carbonate, and organic polymer fillers. Among these, spherical beads of organic polymer are preferable as the filler. The organic beads are spherical polymers containing carbon and may have an elliptical shape. The surface of the organic beads may be covered with silica or the like.

Examples of the polymer constituting the organic beads include acrylic polymers such as polymethylmethacrylate, crosslinked polymethylmethacrylate, crosslinked polybutylmethacrylate, and crosslinked polyacrylic acid ester, crosslinked styrene, nylon, silicone, crosslinked silicone, crosslinked urethane, etc. Is mentioned. Among them, crosslinked beads containing a urethane bond in the molecule are preferable from the viewpoint of achieving both hardness and flexibility of the cured film.

<Other ingredients>
The curable resin composition may contain various additives such as an adhesion aid, a defoaming agent, a leveling agent, a polymerization inhibitor, and a flame retardant, if necessary. Examples of the defoaming agent and the leveling agent include silicone compounds and acrylic compounds. Examples of the adhesion aid (also referred to as an adhesion promoter) include silane coupling agents, triazole compounds, tetrazole compounds, triazine compounds and the like. Examples of the polymerization inhibitor include hydroquinone and hydroquinone monomethyl ether. As the flame retardant, a phosphoric acid ester compound, a halogen-containing compound, a metal hydroxide, an organic phosphorus compound, a silicone compound or the like can be used.

[Content of each component]
As described above, the component (A), the component (B) and the component (C) are involved in heat curing, and the component (B) and the component (D) are involved in photocuring. In the thermosetting film which is only thermoset but not photocured, the component (D) remains unreacted and acts as a plasticizer. In the photothermosetting film that is thermally cured after photocuring, all of the components (A), (B), (C) and (D) are involved in curing.

The content of the component (A) is preferably 10 to 50 parts by weight based on 100 parts by weight of the total of the components (A), (B), (C) and (D). The total content is preferably 40 to 85 parts by weight, and the content of the component (C) is preferably 25 parts by weight or more. The content of the component (A) is preferably 10 to 50% by weight, and the total content of the components (B) and (C) is preferably 45 to 85% by weight, based on the total solid content of the curable resin composition. The content of component C) is preferably 20 parts by weight or more. The total solid content means the total amount of solid content of the components (E), the filler, other resin components, additives, etc. in addition to the components (A) to (D). By setting the content of each component within the above range, the heat resistance and chemical resistance of the cured film can be improved.

When the content of component (A) is small, the heat resistance of the cured film tends to decrease. On the other hand, when the content of the component (A) is excessively large, the photothermosetting film may be brittle and the flexibility may be lowered because the crosslinking density due to photocuring is low. The content of the component (A) based on 100 parts by weight of the total of the components (A) to (D) is more preferably 12 to 40 parts by weight, further preferably 13 to 35 parts by weight. The content of the component (A) based on the total solid content is more preferably 11 to 35% by weight, further preferably 12 to 30% by weight.

The conventional photocurable / thermosetting resin composition used as a photosensitive resist material is inferior in heat resistance when a cured film is formed only by thermosetting without photocuring. In the curable resin composition of the present invention, the content of the thermosetting resin is larger than that of the photocurable / thermosetting resin composition used for a general photosensitive resist. Therefore, it has heat resistance that can be practically used only by thermosetting, and also has excellent durability against repeated bending because the thermosetting film has high flexibility.

Since the component (B) and the component (C) participate in the thermosetting together with the component (A), the larger the total amount of the component (B) and the component (C), the higher the heat resistance of the thermosetting film and the photothermosetting film. Tends to improve. In order to control the balance of heat resistance and flexibility of both the thermosetting film and the photothermosetting film, the content of the component (B) and the component (C) with respect to 100 parts by weight of the total of the components (A) to (D). The total amount is more preferably 55 to 80 parts by weight, still more preferably 60 to 75 parts by weight. The total content of the component (B) and the component (C) with respect to the total solid content is more preferably 50 to 80% by weight, further preferably 60 to 75% by weight. From the viewpoint of enhancing the property balance of the cured film, the ratio (B) / (C) of the content of the component (B) and the content of the component (C) is more preferably 0.5 to 2, and 0.7 to 1 0.5 is more preferable.

Since the component (B) is involved in both photo-curing and heat-curing, the higher the content of the component (B), the more the heat resistance of the photo-thermosetting film tends to improve. On the other hand, when the content of the component (B) is excessively large, the flexibility of the photothermosetting film tends to decrease. The total content of the component (B) per 100 parts by weight of the total of the components (A) to (D) is preferably 25 to 60 parts by weight, more preferably 30 to 50 parts by weight, and further preferably 33 to 45 parts by weight. . The content of the component (B) with respect to the total solid content is preferably 20 to 60% by weight, more preferably 25 to 50% by weight, and further preferably 30 to 40% by weight.

Since the component (C) is involved only in thermosetting and not in photocuring, the flexibility of the photothermosetting film tends to be improved as the content of the component (C) is increased. On the other hand, when the content of the component (C) is excessively large, the heat resistance of the photothermosetting film tends to decrease. The total content of the component (C) per 100 parts by weight of the total of the components (A) to (D) is preferably 25 to 60 parts by weight, more preferably 30 to 50 parts by weight, and further preferably 33 to 45 parts by weight. . The content of the component (C) with respect to the total solid content is preferably 20 to 60% by weight, more preferably 25 to 50% by weight, and further preferably 30 to 40% by weight.

Since the component (D) is involved only in photo-curing and not in heat curing, the larger the content of the component (D), the more the flexibility of the thermosetting film tends to improve. On the other hand, when the content of the component (D) is excessively large, there is concern that the heat resistance of the thermosetting film may decrease and the flexibility of the photocuring film may decrease. The total content of the component (D) is preferably 5 to 30 parts by weight, more preferably 10 to 20 parts by weight, based on 100 parts by weight of the total of the components (A) to (D). The content of the component (D) with respect to the total solid content is preferably 5 to 30% by weight, more preferably 10 to 20% by weight.

The content of component (E) may be set appropriately. From the viewpoint of increasing the photosensitivity and preventing overexposure, it is preferable to add about 0.1 to 20 parts by weight of the component (E) to 100 parts by weight of the total of the components (B) and (D).

When a filler is blended, it is preferably 1 to 80% by weight, more preferably 5 to 50% by weight, even more preferably 10 to 30% by weight, based on the total solid content. When the content of the filler is within the above range, the tack-free property is excellent, and the warp of the cured film tends to be reduced. Further, when the content of the filler is in the above range, the durability against repeated bending of the thermosetting film tends to be improved.

[Preparation of curable resin composition]
A curable resin composition is obtained by mixing the above components and, if necessary, an appropriate solvent. Each of the above components may be subjected to operations such as pulverization / dispersion and defoaming before and / or after mixing, if necessary. The pulverization / dispersion may be carried out, for example, by using a kneading device such as a bead mill, a ball mill, or a triple roll.

[Cured film formation]
A cured film is formed by applying the curable resin composition to a substrate, removing the solvent by heating if necessary, and then performing photocuring and / or heat curing.

The resin composition (solution) may be applied onto the substrate by screen printing, curtain roll, reverse roll, spray coating, spin coating using a spinner, or the like. The thickness of the coating film may be adjusted so that the thickness after drying is about 5 to 100 μm, preferably about 10 to 50 μm. When drying by heating, the drying temperature is preferably 120 ° C. or lower, more preferably 40 to 100 ° C., from the viewpoint of suppressing the thermosetting reaction.

When forming a thermosetting film, the component (A), the component (B) and the component (C) may be thermoset by heat treatment of the coating film. The curing temperature (maximum temperature at the time of thermal curing) is preferably 100 to 250 ° C. or less, more preferably 120 to 200 ° C., and 130 from the viewpoint of sufficiently promoting thermal curing and suppressing oxidation of metal wiring due to heat. It is more preferably up to 180 ° C.

When forming a photo-cured film, the coating film may be exposed. At the time of exposure, a negative-type photomask is arranged on the coating film, and active rays such as ultraviolet rays, visible rays, and electron rays are irradiated to selectively cure the exposed portions. Next, by developing with a shower, paddle, dipping or the like, the non-exposed portion is dissolved, so that a pattern cured film is formed.

Generally, an alkaline aqueous solution is used as the developing solution. In the resin composition, since the component (B) and the component (C) have acidic functional groups, the unexposed coating film has alkali solubility. As the alkaline aqueous solution, an organic alkaline aqueous solution and an inorganic alkaline aqueous solution can be used without particular limitation. The developing solution may contain an organic solvent miscible with water, such as methanol, ethanol, n-propanol, isopropanol, N-methyl-2-pyrrolidone. The alkali concentration of the developer is generally 0.01 to 20% by weight, preferably 0.02 to 10% by weight, and the temperature of the developer is generally 0 to 80 ° C, preferably 10 to 60 ° C. The pattern-cured film after development is preferably rinsed with a rinse liquid such as water or an acidic aqueous solution.

By heating the photocured film, the thermosetting proceeds by the reaction of the (A) component with the (B) component and the (C) component, so that a photothermoset film is obtained. The heating conditions in the thermal curing after the photo-curing are the same as the heating conditions in forming the thermosetting film.

The photo-cured film obtained from the resin composition has a resolution of, for example, about 10 to 1000 μm, and thus is suitable for use as a surface protective material for printed circuit boards. Further, since the cured film is excellent in flexibility, it is also suitably used as a cured film of a flexible printed board having metal wiring on a flexible film such as a polyimide film.

[Preparation of substrate with cured film]
The curable resin composition of the present invention has excellent flexibility and heat resistance when used as a thermosetting film without photocuring, and excellent when used as a photocuring film or a photothermosetting film. It has patterning property and heat resistance. By using this resin composition, one type of resin composition may be used to form a substrate with a cured film on which a thermosetting film and a photocurable film are provided on one substrate.

FIG. 1 is a plan view of a flexible printed circuit board 10 used in a bendable device. The flexible printed circuit board has metal wiring made of copper or the like on one or both sides of a flexible film such as a polyimide film. The wiring is not shown in FIG.

The flexible printed circuit board 10 is bent along the line FF when incorporated in a device such as a foldable display. Therefore, the region 12 (bending region) extending along the line FF is required to have high flexibility. On the other hand, in the bent region 12, since no element is mounted on the substrate, it is preferable to form a cured film on the entire bent region, and it is not necessary to pattern the cured film. Therefore, the bending region 12 is provided with a thermosetting film having excellent flexibility.

In

areas

11A and 11B (mounting areas), elements are mounted on the wiring on the board. Since it is necessary to make holes in the cured film in the portion where the element is mounted, the resin composition forming the cured film is required to have photosensitivity in the mounting region. On the other hand, the mounting area is not required to be flexible after being incorporated in the device. Therefore, a photo-curing film or a photo-thermosetting film is provided in the mounting

areas

11A and 11B.

Thus, in the mounting area, the resin composition is used as a photocurable (photosensitive) composition to form a photocurable film or a photothermosetting film, and in the bending area, the resin composition is used as a thermosetting composition. When the thermosetting film is formed by using one type of resin composition, a cured film-coated substrate including a photocurable film having patterning properties and a thermosetting film having excellent flexibility can be obtained on the substrate.

A photo-cured film is formed by applying a curable resin composition to the mounting

areas

11A and 11B of the substrate 10 to form a coating film and performing exposure. By performing pattern exposure using a mask during exposure and developing with an alkaline aqueous solution or the like, it is possible to form a pattern-cured film having openings for mounting elements and the like. The photothermosetting film can be formed by heating the photocuring film.

A thermosetting film can be formed by applying a resin composition to the bending region 12 of the substrate 10 to form a coating film, and heating the coating film to thermally cure it. Either the formation of the thermosetting film or the formation of the photocuring film may be performed first, or both may be performed in parallel.

FIG. 2 is a schematic cross-sectional view showing the process flow of the embodiment in which the thermosetting film is first formed. In this embodiment, first, a coating film 22 of the curable resin composition is formed on the bending region 12 of the substrate 10 (FIG. 2A), and the coating film is heat-cured by heating, so that the bending region 12 is thermally cured. The film 22T is formed (FIG. 2B).

After forming the thermosetting film 22T, a coating film 21 of the resin composition is formed on the mounting

areas

11A and 11B (FIG. 2C), and pattern exposure is performed through a photomask. When pattern exposure is performed, the coating film is photo-cured in the exposed region to form the photo-cured film 21P. In the unexposed area, the coating film 21X is uncured. When development is performed using an alkaline aqueous solution or the like, the uncured coating film 21X is dissolved and removed, so that a patterned cured film is obtained (FIG. 2E). At this time, the coating film 22T on the bent region 12 has not been dissolved in the developing solution because it has been thermally cured first.

By heating the patterned photo-cured film, heat curing proceeds, and the patterned photo-cured film 21Q is formed in the mounting

regions

11A and 11B.

FIG. 3 is a schematic cross-sectional view showing the process flow of the embodiment in which the photo-cured film is formed first. In this embodiment, first, the coating film 21 of the resin composition is formed on the mounting

areas

11A and 11B of the substrate 10 (FIG. 3A). By performing pattern exposure through a photomask (FIG. 3B) and developing, the coating film 21X in the unexposed region is dissolved and removed, and a pattern cured film 21P is formed (FIG. 3C).

Next, a coating film 22 of the curable resin composition is formed on the bent region 12 of the substrate 10 (FIG. 3D). Then, when the substrate 10 is heated, the photo-cured film 21P on the mounting

regions

11A and 11B and the coating film 22 on the bending region 12 are thermo-cured at the same time, and the patterned photo-thermo-cured film is formed on the mounting

regions

11A and 11B. 21Q is provided, and the cured film-coated substrate in which the thermosetting film 22T is provided in the bent region 12 is obtained. In this method, the resin composition in both the mounting region and the bending region can be thermoset by heating once, so the process becomes simpler. Before forming the coating film on the bent region 12, the photo-curing film 21P may be thermally cured, if necessary.

As described above, the curable resin composition of the present invention can be applied to both formation of a thermosetting film having excellent flexibility, and formation of a photocuring film having excellent paneling property and heat resistance. Therefore, one resin composition can be used to form a substrate with a cured film including a thermosetting film and a photocurable film on one substrate, and the process management can be simplified. In addition, it is possible to omit processes such as equipment cleaning accompanying the switching of materials, which can contribute to improvement in productivity.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Synthesis example]
In the following synthesis examples, a polymer having a carboxy group as an acidic functional group and having no ethylenically unsaturated group was polymerized. The properties of the solutions and polymers (C-1), (C-2) and (C-3) obtained in Synthesis Examples 1 to 3 were evaluated by the following methods.

<Solid content concentration>
The measurement was performed according to JIS K 5601-1-2. The drying condition was 170 ° C. × 1 hour.

<Weight average molecular weight>
The measurement was carried out by gel permeation chromatography (GPC) under the following conditions.
Equipment used: Tosoh HLC-8220GPC equivalent Column: Tosoh TSK gel Super AWM-H (6.0mm ID x 15cm) x 2 Guard column: Tosoh TSK guard column Super AW-H
_{Eluent: 30mM LiBr + 20mM H 3 PO} 4 in DMF
Flow rate: 0.6 mL / min
Column temperature: 40 ° C
Detection conditions: RI: Polarity (+), Response (0.5 sec)
Sample concentration: Approximately 5 mg / mL
Molecular weight standard: PEG (polyethylene glycol)

<Acid value>
The measurement was performed according to JIS K 5601-2-1.

(Synthesis example 1)
In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a nitrogen inlet tube, 100.0 g of methyltriglyme (1,2-bis (2-methoxyethoxy) ethane) was charged as a polymerization solvent, and the mixture was put under a nitrogen stream. The temperature was raised to 80 ° C. with stirring. 12.0 g (0.14 mol) of methacrylic acid, 28.0 g (0.16 mol) of benzyl methacrylate, 60.0 g (0.42 mol) of butyl methacrylate, which had been mixed in advance with this at room temperature. And 0.5 g of azobisisobutyronitrile as a radical polymerization initiator was added dropwise from the dropping funnel over a period of 3 hours while keeping the temperature at 80 ° C. After the completion of the dropping, the reaction solution was heated to 90 ° C. with stirring, and further stirred for 2 hours while maintaining the temperature of the reaction solution at 90 ° C. to obtain an acrylic polymer (C-1) containing a carboxy group in the molecule. A solution of The solid content concentration of the solution was 50%, the weight average molecular weight of the polymer was 48,000, and the acid value was 78 mgKOH / g.

(Synthesis example 2)
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a nitrogen introducing tube was charged with 30.00 g of methyltriglyme and 10.31 g (0.050 mol) of norbornene diisocyanate as a solvent for polymerization, and stirred under a nitrogen stream. While heating to 80 ° C., it was dissolved. To this solution, 50.00 g (0.025 mol) of polycarbonate diol (“PCDL T5652” manufactured by Asahi Kasei, weight average molecular weight 2000) and 3.70 g (0.025 mol) of 2,2-bis (hydroxymethyl) butanoic acid were added. A solution dissolved in 30.00 g of methyl triglyme was added dropwise over 1 hour. This solution was heated and stirred at 80 ° C. for 5 hours to obtain a solution of urethane polymer (C-2) containing a carboxy group in the molecule. The solid content concentration of the solution was 52%, the weight average molecular weight of the polymer was 5,600, and the acid value was 22 mgKOH / g.

(Synthesis example 3)
A reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a nitrogen introduction tube was charged with 35.00 g of methyl triglyme and 10.31 g (0.050 mol) of norbornene diisocyanate as a polymerization solvent, and stirred under a nitrogen stream. While heating to 80 ° C., it was dissolved. To this solution, a solution prepared by dissolving 50.00 g (0.025 mol) of polycarbonate diol in 35.00 g of methyl triglyme was added dropwise from a dropping funnel over 1 hour, and the mixture was heated and stirred at 80 ° C. for 2 hours, and then 3,3. 15.51 g (0.050 mol) of ', 4,4'-oxydiphthalic acid dianhydride was added, the temperature was raised to 190 ° C., and the mixture was heated and stirred for 1 hour. Then, the mixture was cooled to 80 ° C., 3.60 g (0.200 mol) of pure water was added, the temperature was raised to 110 ° C., and the mixture was heated under reflux for 5 hours to give a urethane imide polymer (C containing a carboxy group in the molecule). A solution of -3) was obtained. The solid content concentration of the solution was 53%, the weight average molecular weight of the polymer was 9,200, and the acid value was 86 mgKOH / g.

[Preparation of Resin Compositions of Examples and Comparative Examples]
The composition having the composition shown in Table 1 was dissolved in methyl triglyme, stirred with a stirrer, and then passed twice with a three-roll mill. Then, defoaming was performed with a defoaming device to prepare a uniform solution. The amount of each component in Table 1 is a solid content, and the amount of methyl triglyme as a solvent was 30 parts by weight. In addition to the components shown in Table 1, 1 part by weight of a butadiene-based defoaming agent (“Floren AC-2000” manufactured by Kyoeisha Chemical Co., Ltd.) was added to each resin composition.

[Cured film formation and evaluation]
<Heat resistance of thermosetting film>
A copper foil of a flexible copper-clad laminate obtained by laminating a polyimide film of 25 μm thickness (“Apical 25 NPI” manufactured by Kaneka) and an electrolytic copper foil of 12 μm thickness with a polyimide-based adhesive is a stripe of line width / space width = 100 μm / 100 μm. The pattern was etched, immersed in a 10% by volume sulfuric acid aqueous solution for 1 minute to surface-treat the copper foil, and then washed with pure water to prepare a flexible printed circuit board. Using a Baker type applicator, the resin composition was cast / coated on an area of 100 mm × 100 mm so that the final dry thickness was 20 μm, and dried at 80 ° C. for 20 minutes on the wiring forming surface of this flexible printed board. After that, heating was performed in an oven at 150 ° C. for 30 minutes to form a thermosetting film.

This sample was immersed in a solder bath at 320 ° C., and after 10 seconds, pulled up, an external appearance was observed and a tape peeling test was performed, and the following criteria were evaluated.
◯: No change in appearance before and after the test, the cured film did not peel in the tape peeling test Δ: No change in appearance, but the cured film peeled in the tape peeling test ×: Swelling or peeling of the cured film after the test The appearance changes such as

<Flexibility of thermosetting film>
Using a baker type applicator, the resin composition was cast / applied to a 25 μm thick polyimide film (“Apical 25 NPI” manufactured by Kaneka) in an area of 100 mm × 100 mm so that the final dry thickness was 20 μm, and at 80 ° C. After drying for 20 minutes, heating was performed in an oven at 150 ° C. for 30 minutes to form a thermosetting film.

This sample was cut into a size of 15 mm × 100 mm, bent 180 ° so that the cured film was on the outside, and a load of 200 g was placed on the bent portion for 3 seconds. After removing the load, the bent portions were visually observed to evaluate the presence or absence of cracks. This operation was repeated until a crack was formed in the cured film, and the number of times that no crack was generated was defined as the folding endurance number. For example, if a crack occurs in the second test, the folding endurance is 1. If no crack was generated even in the 10th test, the folding endurance was set to 10 or more (≧ 10).

<Photosensitivity>
On a polyimide film (“Apical 25 NPI” manufactured by Kaneka) having a thickness of 25 μm, the resin composition is cast / applied to an area of 100 mm × 100 mm using a Baker type applicator so that the final dry thickness is 20 μm, and the temperature is 80 ° C. And dried for 20 minutes. A negative type photomask having a line width / space width = 100 μm / 100 μm was placed, and after exposure by irradiating ultraviolet rays with an integrated exposure amount of 300 mJ / cm ² using a high pressure mercury lamp, 1.0% by weight A sodium carbonate aqueous solution (30 ° C.) was sprayed at a discharge pressure of 1.0 kgf / mm ² for 90 seconds for development. After washing with pure water, it was heated and cured in an oven at 150 ° C. for 30 minutes to form a patterned cured film.

Relief patterns formed using the compositions of Examples and Comparative Examples were observed with an optical microscope, and no significant line thickening or development residue of the pattern was observed with any composition. , A line width / space width = 100/100 μm photosensitive pattern could be drawn.

<Heat resistance of photothermosetting film>
Similar to the evaluation of heat resistance of the thermosetting film, the resin composition was cast / coated so that the final dry thickness was 20 μm, and dried at 80 ° C. for 20 minutes. After that, exposure, development and heat curing were carried out in the same manner as in the evaluation of photosensitivity to form a photothermosetting film on the wiring formation surface of the flexible printed board. At the time of exposure, a photomask was not used and the entire surface was irradiated with ultraviolet rays. Using this sample, the heat resistance was evaluated by immersing it in a solder bath at 320 ° C. in the same manner as the heat resistance of the thermosetting film.

<Flexibility of photothermosetting film>
Similar to the evaluation of the flexibility of the thermosetting film, the resin composition was cast / coated so that the final dry thickness was 20 μm, and dried at 80 ° C. for 20 minutes. Then, exposure, development and heat curing were performed in the same manner as in the above-mentioned evaluation of photosensitivity to form a photothermosetting film on the polyimide film. At the time of exposure, a photomask was not used and the entire surface was irradiated with ultraviolet rays. Using this sample, a folding endurance test was carried out to evaluate the flexibility in the same manner as the evaluation of the flexibility of the thermosetting film.

Table 1 shows a list of compounding and evaluation results of the resin compositions of Examples and Comparative Examples. Details of each component are as shown below.

(1) "jER828" manufactured by Mitsubishi Chemical; bisphenol A type epoxy resin (average molecular weight 370, epoxy equivalent 190)
(2) Nippon Kayaku "KAYARAD UXE-3000"; carbitol acetate diluted solution of acid-modified epoxy acrylate having urethane skeleton (weight average molecular weight 10,000, acid value 98 mgKOH / g)
(3) Nippon Kayaku "KAYARAD DPHA"; a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (4) BASF "Irgacure OXE02"; ethanone, 1- [9-ethyl-6- (2-methyl Benzoyl) -9H-carbazol-3-yl]-, 1- (o-acetyloxime)
(5) Negami Kogyo's "Art Pearl TK-800T"; Polycarbonate cross-linked urethane beads with an average particle size of 6 μm

In Comparative Example 1 in which the amount of the component (A) was small, the cured film had excellent flexibility, but both the thermosetting film and the photothermosetting film were inferior in heat resistance. On the other hand, in Comparative Example 3 in which the amount of the component (A) was large and the amounts of the components (B) and (C) were small, the photothermosetting film exhibited excellent heat resistance, but the flexibility of the thermosetting film was high. Was inferior. In Comparative Example 2 in which the blending amount of the component (C) was small, both the thermosetting film and the photothermosetting film had excellent heat resistance, but the flexibility was insufficient.

In Examples 1 to 4, in the folding endurance test of the thermosetting film, the cured film did not crack even after 10 times of tests, and showed excellent flexibility. Further, both the thermosetting film and the photothermosetting film have excellent heat resistance, and one type of resin composition is used as a thermosetting cover material that requires flexibility and heat resistance, and It was shown to be applicable to both use as a photosensitive cover material that requires heat resistance and fine workability.

Claims

A curable resin composition having photocurability and thermosetting property,
(A) Thermosetting resin; (B) Polymer having acidic functional group and ethylenically unsaturated group; (C) Polymer having acidic functional group and not having ethylenically unsaturated group; (D) Ethylenic A compound having an unsaturated group; and (E) a photopolymerization initiator,
The component (A), the component (B), the component (C) and the component (D) are contained in an amount of 10 to 50 parts by weight based on 100 parts by weight in total, and the component (B) is added. A curable resin composition in which the total content of the component (C) is 40 to 85 parts by weight and the content of the component (C) is 25 parts by weight or more.
The content of the component (D) is 5 to 30 parts by weight based on 100 parts by weight of the total of the components (A), (B), (C) and (D). The curable resin composition described.
A curable resin composition having thermosetting and photocuring properties,
(A) Thermosetting resin; (B) Polymer having acidic functional group and ethylenically unsaturated group; (C) Polymer having acidic functional group and not having ethylenically unsaturated group; (D) Ethylenic A compound having an unsaturated group and having no reactivity with the thermosetting resin (A); and (E) a photopolymerization initiator,
The content of the component (A) in the total solid content is 10 to 50% by weight, the total content of the components (B) and (C) is 45 to 85% by weight, and the content of the component (C) is 20. Curable resin composition which is more than weight part.
The curable resin composition according to claim 3, wherein the content of the component (D) in the total solid content is 5 to 30% by weight.
The curable resin composition according to any one of claims 1 to 4, wherein the component (A) is an epoxy resin, and the acidic functional groups of the components (B) and (C) are carboxy groups.
6. The (B) and the (C) each have an acid value of 5 to 200 mgKOH / g and a weight average molecular weight of 1,000 to 1,000,000. The curable resin composition according to.
The curable resin composition according to any one of claims 1 to 6, which comprises, as the component (D), a compound having 4 or more ethylenically unsaturated groups in one molecule.
The curable resin composition according to any one of claims 1 to 7, wherein the component (D) contains a compound having an ethylenically unsaturated group functional group equivalent of 300 or less.
The curable resin composition according to any one of claims 1 to 8, which further contains an organic filler.
A cured film comprising a cured product of the curable resin composition according to any one of claims 1 to 9.
A substrate with a cured film, which comprises a cured film made of a cured product of the curable resin composition according to any one of claims 1 to 10 on the substrate.
The substrate with a cured film according to claim 11, wherein the substrate is a flexible printed circuit board.
A method of manufacturing a substrate with a cured film comprising a cured film on a substrate having a first region and a second region,
A step of applying the curable resin composition according to any one of claims 1 to 9 on the first region of the substrate to form a first coating film;
A step of applying the curable resin composition according to any one of claims 1 to 9 on the second region of the substrate to form a second coating film;
Exposing the first coating film on the first region to photo-curing; and heating the second coating film on the second region to thermally cure.
A method for producing a substrate with a cured film, comprising:
When the first coating film is exposed, pattern exposure is performed using a mask, development is performed after the exposure, and the coating film in the unexposed portion on the first region is removed to form the first region on the first region. The method for producing a substrate with a cured film according to claim 13, wherein the patterned photo-cured film is formed.
The method for producing a substrate with a cured film according to claim 13 or 14, wherein after the first coating film is exposed, heat curing is further performed by heating.
The heat treatment of the second coating film is followed by the formation of the first coating film on the first region and the photo-curing of the first coating film, according to any one of claims 13 to 15. Manufacturing method of substrate with cured film.
After photo-curing the first coating film, forming a second coating film on the second region,
The method for manufacturing a substrate with a cured film according to any one of claims 13 to 15, wherein the photo-cured film on the first region and the second coating film on the first region are heated at the same time to perform thermal curing. .
The method for manufacturing a substrate with a cured film according to claim 13, wherein the substrate is a flexible printed board.