JP2014220342A - Printed wiring board material and printed wiring board using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed wiring board material excellent in crack resistance and to provide a printed wiring board using the same.SOLUTION: The printed wiring board material includes: a binder component; and a cellulose nanofiber, containing a carboxylate, having a number-average fiber diameter of 3 nm to 1000 nm, which may be suitably used for a solder resist 12, a core material 2, and interlayer insulation materials 6, 9 of a multi-layer printed wiring board. The printed wiring board material is used for the printed wiring board.

Description

  The present invention relates to a printed wiring board material and a printed wiring board using the same.

  As a wiring board such as a printed wiring board, a metal material such as copper is applied to a fiber such as glass impregnated with an epoxy resin, which is called a core material, and a circuit is formed by an etching method, There is one in which a circuit is formed after an insulating layer is formed by coating an insulating resin composition or laminating a sheet-like insulating resin composition. In addition, a solder resist is formed on the outermost layer of the wiring board for the purpose of protecting the formed circuit and mounting the electronic component at the correct position. In general, an insulating material such as an epoxy resin or an acrylate resin is used for the solder resist (see, for example, Patent Documents 1, 2, and 3).

  In such a wiring board, the component bonding material such as a semiconductor chip, underfill, and solder constituting the wiring board, and the insulating layer made of each of the above insulating materials have different thermal expansion coefficients, Since it is hard, there has been a problem that cracks occur in the insulating layer and in the component joint due to expansion and contraction during the component mounting process (for example, see Patent Documents 4 and 5). For example, in a temperature cycle test at -65 ° C to 150 ° C, cracks are likely to occur due to deformation or breakage due to stress between different materials, and thus crack resistance against this is required.

JP 2006-182991 A (Claims etc.) JP 2013-36042 A (Claims etc.) Japanese Patent Laid-Open No. 08-269172 (Claims etc.) JP 2009-271290 A (Claims etc.) International Publication No. 2011/088685 (Claims etc.)

  The objective of this invention is providing the printed wiring board material which is excellent in crack resistance, and a printed wiring board using the same.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by using a material containing specific cellulose nanofibers as a printed wiring board material, and have completed the present invention.

  That is, the printed wiring board material of the present invention includes a binder component and cellulose nanofibers having a number average fiber diameter of 3 nm to 1000 nm having a carboxylate salt in the structure.

  In the present invention, the cellulose nanofiber was obtained by using natural cellulose fiber as a raw material, and oxidizing the natural cellulose fiber in water using an N-oxyl compound as an oxidation catalyst and a co-oxidant acting. It is preferable. In the printed wiring board material of the present invention, a thermoplastic resin and a curable resin can be suitably used as the binder component. The printed wiring board material of the present invention can be suitably used for a solder resist, a core material, and an interlayer insulating material of a multilayer printed wiring board.

  The printed wiring board of the present invention is characterized by using the printed wiring board material of the present invention.

  According to the present invention, it is possible to realize a printed wiring board material excellent in crack resistance and a printed wiring board using the printed wiring board material because of the above configuration.

It is a fragmentary sectional view which shows one structural example of the multilayer printed wiring board which concerns on this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The printed wiring board material of the present invention is characterized in that it contains a binder component and cellulose nanofibers having a number average fiber diameter of 3 nm to 1000 nm having a carboxylate salt in the structure. Such cellulose nanofibers can be obtained by oxidizing natural cellulose fibers and then refining them according to the following.

  First, an aqueous dispersion is prepared by dispersing natural cellulose fibers in about 10 to 1000 times (mass basis) of water on an absolute dry basis using a mixer or the like. Examples of the natural cellulose fiber used as a raw material for the cellulose nanofiber include wood pulp such as softwood pulp and hardwood pulp, non-wood pulp such as straw pulp and bagasse pulp, cotton pulp such as cotton lint and cotton linter, Examples include bacterial cellulose. These may be used individually by 1 type, or may be used in combination of 2 or more types as appropriate. Further, these natural cellulose fibers may be subjected to a treatment such as beating in order to increase the surface area in advance.

  Next, the natural cellulose fiber is oxidized in the aqueous dispersion using an N-oxyl compound as an oxidation catalyst. Examples of such N-oxyl compounds include TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl), 4-carboxy-TEMPO, 4-acetamido-TEMPO, 4-amino-TEMPO, 4 -Dimethylamino-TEMPO, 4-phosphonooxy-TEMPO, 4-hydroxy TEMPO, 4-oxy TEMPO, 4-methoxy TEMPO, 4- (2-bromoacetamido) -TEMPO, 2-azaadamantane N-oxyl, etc. TEMPO derivatives having various functional groups at the C4 position can be used. As the addition amount of these N-oxyl compounds, a catalytic amount is sufficient, and it can usually be in a range of 0.1 to 10% by mass with respect to natural cellulose fiber on an absolute dry basis.

  In the oxidation treatment of the natural cellulose fiber, an oxidizing agent and a co-oxidizing agent are used in combination. Examples of the oxidizing agent include halous acid, hypohalous acid and perhalogenic acid and salts thereof, hydrogen peroxide, perorganic acid, among which sodium hypochlorite and sodium hypobromite. Alkali metal hypohalites such as are preferred. Further, as the co-oxidant, for example, an alkali metal bromide such as sodium bromide can be used. The amount of the oxidizing agent used is usually in a range of about 1 to 100% by mass based on the absolute dry standard with respect to the natural cellulose fiber, and the amount of the co-oxidant used is usually based on the absolute dry standard with respect to the natural cellulose fiber. Is about 1 to 30% by mass.

  In the oxidation treatment of the natural cellulose fiber, it is preferable to maintain the pH of the aqueous dispersion in the range of 9 to 12 from the viewpoint of efficiently proceeding the oxidation reaction. Further, the temperature of the aqueous dispersion during the oxidation treatment can be arbitrarily set within the range of 1 to 50 ° C., and the reaction can be performed at room temperature without temperature control. The reaction time can be in the range of 1 to 240 minutes. In addition, a penetrant can be added to the aqueous dispersion in order to allow the drug to penetrate into the inside of the natural cellulose fiber and introduce more carboxyl groups into the fiber surface. Examples of the penetrating agent include anionic surfactants such as carboxylate, sulfate ester salt, sulfonate salt, and phosphate ester salt, and nonionic surfactants such as polyethylene glycol type and polyhydric alcohol type. .

  After the oxidation treatment of the natural cellulose fiber, it is preferable to perform a purification treatment to remove impurities such as unreacted oxidant and various by-products contained in the aqueous dispersion prior to the refinement. Specifically, for example, a technique of repeatedly washing and filtering the oxidized natural cellulose fiber can be used. The natural cellulose fiber obtained after the refining treatment is usually subjected to a refining treatment in a state impregnated with an appropriate amount of water. However, if necessary, the natural cellulose fiber may be dried to obtain a fibrous or powdery form.

  Next, refinement | purification of the natural cellulose process is performed in the state which disperse | distributed the natural cellulose fiber refine | purified if desired in solvents, such as water. The solvent as a dispersion medium used in the micronization treatment is usually preferably water, but if desired, alcohols (methanol, ethanol, isopropanol, isobutanol, sec-butanol, tert-butanol, methyl cellosolve, ethyl cellosolve, Ethylene glycol, glycerol, etc.), ethers (ethylene glycol dimethyl ether, 1,4-dioxane, tetrahydrofuran, etc.), ketones (acetone, methyl ethyl ketone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, etc.) A water-soluble organic solvent may be used, or a mixture thereof may be used. The solid content concentration of the natural cellulose fiber in the dispersion of these solvents is preferably 50% by mass or less. When the solid content concentration of the natural cellulose fiber exceeds 50% by mass, extremely high energy is required for dispersion, which is not preferable. Refinement of natural cellulose treatment includes low-pressure homogenizers, high-pressure homogenizers, grinders, cutter mills, ball mills, jet mills, beating machines, disintegrators, short-screw extruders, twin-screw extruders, ultrasonic agitators, household juicer mixers, etc. This can be done using a dispersing device.

  Cellulose nanofibers obtained by the refining treatment can be made into a suspension in which the solid content concentration is adjusted or a dried powder as desired. Here, in the case of a suspension, only water may be used as a dispersion medium, and water and other organic solvents, for example, alcohols such as ethanol, surfactants, acids, bases, etc. A mixed solvent may be used.

  By the oxidation treatment and refinement treatment of the natural cellulose fiber, the hydroxyl group at the C6 position of the structural unit of the cellulose molecule is selectively oxidized to a carboxyl group via an aldehyde group, and the content of the carboxyl group is 0.1. A highly crystalline cellulose nanofiber having a predetermined number average fiber diameter, which is composed of cellulose molecules of ˜3 mmol / g, can be obtained. This highly crystalline cellulose nanofiber has a cellulose I-type crystal structure. This means that the cellulose nanofibers are those obtained by surface-oxidizing naturally-derived cellulose molecules having an I-type crystal structure. That is, natural cellulose fibers have a high-order solid structure formed by a bundle of fine fibers called microfibrils produced in the process of biosynthesis, and a strong cohesive force between the microfibrils (between surfaces). The cellulose nanofibers can be obtained by weakening the hydrogen bond) by introducing an aldehyde group or a carboxyl group by an oxidation treatment, and further through a refinement treatment. By adjusting the conditions of the oxidation treatment, the content of the carboxyl group is increased or decreased, the polarity is changed, or by the electrostatic repulsion or refinement treatment of the carboxyl group, the average fiber diameter or average fiber length of the cellulose nanofiber, The average aspect ratio can be controlled.

That the natural cellulose fiber has the I-type crystal structure is typical at two positions near 2θ = 14-17 ° and 2θ = 22-23 ° in the diffraction profile obtained by measuring the wide-angle X-ray diffraction image. It can be identified from having a typical peak. In addition, the introduction of a carboxyl group into the cellulose molecule of the cellulose nanofibers indicates that in a sample from which moisture has been completely removed, absorption due to a carbonyl group (1608 cm ⁻¹ ) in the total reflection infrared spectroscopic spectrum (ATR). This can be confirmed by the presence of the vicinity. In the case of a carboxyl group (COOH), there is an absorption at 1730 cm ⁻¹ in the above measurement.

  In addition, since halogen atoms are attached or bonded to the natural cellulose fiber after the oxidation treatment, dehalogenation treatment can be performed for the purpose of removing such residual halogen atoms. The dehalogenation treatment can be performed by immersing the oxidized natural cellulose fiber in a hydrogen peroxide solution or an ozone solution.

  Specifically, for example, the oxidized natural cellulose fiber is added to a hydrogen peroxide solution having a concentration of 0.1 to 100 g / L in a bath ratio of about 1: 5 to 1: 100, preferably 1:10 to 1. : Immerse under conditions of about 60 (mass ratio). The concentration of the hydrogen peroxide solution in this case is preferably 1 to 50 g / L, and more preferably 5 to 20 g / L. The pH of the hydrogen peroxide solution is preferably 8 to 11, and more preferably 9.5 to 10.7.

The amount [mmol / g] of carboxyl groups in cellulose relative to the weight of cellulose nanofibers contained in the aqueous dispersion can be evaluated by the following method. That is, 60 ml of a 0.5 to 1% by mass aqueous dispersion of a cellulose nanofiber sample whose dry weight was precisely weighed in advance was prepared, and the pH was adjusted to about 2.5 with a 0.1 M aqueous hydrochloric acid solution. An aqueous sodium hydroxide solution is dropped until the pH is about 11, and the electrical conductivity is measured. From the amount (V) of sodium hydroxide consumed in the weak acid neutralization stage where the change in electrical conductivity is slow, the functional group amount can be determined using the following formula. This amount of functional groups indicates the amount of carboxyl groups.
Functional group amount [mmol / g] = V [ml] × 0.05 / cellulose nanofiber sample [g]

  The number average fiber diameter of the cellulose nanofiber used in the present invention is required to be 3 nm to 1000 nm, preferably 3 nm to 200 nm, and more preferably 3 nm to 100 nm. Since the minimum diameter of cellulose nanofiber single fiber is 3 nm, less than 3 nm cannot be produced substantially, and when the number average fiber diameter exceeds 1000 nm, it is excessive to obtain the desired effect of the present invention. It is necessary to add, and film forming property deteriorates. In addition, the number average fiber diameter of the cellulose nanofiber is observed with SEM (Scanning Electron Microscope; Scanning Electron Microscope), TEM (Transmission Electron Microscope; Transmission Electron Microscope), etc., and the diagonal line of the photograph is drawn. This is an average value obtained by extracting 12 points of fibers in the vicinity at random, removing the thickest fiber and the thinnest fiber, and measuring the remaining 10 points.

  The blending amount of the cellulose nanofibers in the printed wiring board material of the present invention is preferably 0.1 to 80% by mass, more preferably 0.2 to 70% by mass with respect to the total amount of the composition excluding the solvent. It is. When the blending amount of the cellulose nanofiber is 0.1% by mass or more, the desired effect of the present invention can be obtained satisfactorily. On the other hand, in the case of 80 mass% or less, film forming property improves.

  As the binder component used in the present invention, a thermoplastic resin and a curable resin such as a thermosetting resin or a photocurable resin can be suitably used.

(Thermoplastic resin)
Thermoplastic resins include acrylic, modified acrylic, low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polypropylene, modified polypropylene, polystyrene, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene copolymer. General-purpose plastics such as polymers, cellulose acetate, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polylactic acid, polyamide, thermoplastic polyurethane, polyacetal, polycarbonate, ultrahigh molecular weight polyethylene, polybutylene terephthalate, modified polyphenylene ether, polysulfone, Polyphenylene sulfide, polyethersulfone, polyetheretherketone, polyarylate, polyetherimide, polyar Doimide, liquid crystal polymer, polyamide 6T, polyamide 9T, polytetrafluoroethylene, polyvinylidene fluoride, polyesterimide, engineering plastics such as thermoplastic polyimide, olefin, styrene, polyester, urethane, amide, vinyl chloride And thermoplastic elastomers such as hydrogenated systems.

(Thermosetting resin)
The thermosetting resin may be any resin that is cured by heating and exhibits electrical insulation. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, bisphenol M type epoxy resin, bisphenol P type epoxy resin, bisphenol type epoxy resin such as bisphenol Z type epoxy resin, bisphenol A novolac type epoxy resin, phenol novolac type epoxy resin, novolac type epoxy resin such as cresol novolac epoxy resin, biphenyl type epoxy Resin, biphenyl aralkyl type epoxy resin, aryl alkylene type epoxy resin, tetraphenylol ethane type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin Fatty, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, adamantane type epoxy resin, fluorene type epoxy resin, glycidyl methacrylate copolymer epoxy resin, copolymer epoxy resin of cyclohexylmaleimide and glycidyl methacrylate , Epoxy-modified polybutadiene rubber derivatives, CTBN-modified epoxy resins, trimethylolpropane polyglycidyl ether, phenyl-1,3-diglycidyl ether, biphenyl-4,4′-diglycidyl ether, 1,6-hexanediol diglycidyl ether , Ethylene glycol or propylene glycol diglycidyl ether, sorbitol polyglycidyl ether, tris (2,3-epoxypropyl) isocyanurate Modified with novolak type phenolic resin such as triglycidyl tris (2-hydroxyethyl) isocyanurate, phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, unmodified resole phenolic resin, tung oil, linseed oil, walnut oil, etc. Phenol resins such as resol type phenol resins such as oil-modified resole phenol resin, triazine ring-containing resins such as phenoxy resin, urea (urea) resin, melamine resin, unsaturated polyester resin, bismaleimide resin, diallyl phthalate resin, silicone resin, Resin having benzoxazine ring, norbornene resin, cyanate resin, isocyanate resin, urethane resin, benzocyclobutene resin, maleimide resin, bismaleimide triazine resin, polyester Azomethine resins, thermosetting polyimides.

(Photo-curing resin (radical polymerization))
Such a photocurable resin may be any resin that is cured by irradiation with active energy rays and exhibits electrical insulation, and particularly a compound having one or more ethylenically unsaturated bonds in the molecule is preferably used. As the compound having an ethylenically unsaturated bond, known and commonly used photopolymerizable oligomers and photopolymerizable vinyl monomers are used.

  Examples of the photopolymerizable oligomer include unsaturated polyester oligomers and (meth) acrylate oligomers. Examples of (meth) acrylate oligomers include phenol novolac epoxy (meth) acrylate, cresol novolac epoxy (meth) acrylate, epoxy (meth) acrylates such as bisphenol type epoxy (meth) acrylate, urethane (meth) acrylate, epoxy urethane (meta ) Acrylate, polyester (meth) acrylate, polyether (meth) acrylate, polybutadiene-modified (meth) acrylate, and the like. In addition, in this specification, (meth) acrylate is a term which generically refers to acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

  As the photopolymerizable vinyl monomer, known and commonly used monomers, for example, styrene derivatives such as styrene, chlorostyrene and α-methylstyrene; vinyl esters such as vinyl acetate, vinyl butyrate or vinyl benzoate; vinyl isobutyl ether, vinyl- vinyl ethers such as n-butyl ether, vinyl-t-butyl ether, vinyl-n-amyl ether, vinyl isoamyl ether, vinyl-n-octadecyl ether, vinyl cyclohexyl ether, ethylene glycol monobutyl vinyl ether, triethylene glycol monomethyl vinyl ether; acrylamide, Methacrylamide, N-hydroxymethylacrylamide, N-hydroxymethylmethacrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylate (Meth) acrylamides such as luamide and N-butoxymethylacrylamide; allyl compounds such as triallyl isocyanurate, diallyl phthalate and diallyl isophthalate; 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tetrahydrofurfuryl Esters of (meth) acrylic acid such as (meth) acrylate, isobornyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate; hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, pentaerythritol Hydroxyalkyl (meth) acrylates such as tri (meth) acrylate; alcohols such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate Xylalkylene glycol mono (meth) acrylates; ethylene glycol di (meth) acrylate, butanediol di (meth) acrylates, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylol Alkylene polyol poly (meth) acrylates such as propane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, Polyoxyalkylene glycol poly (such as ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane tri (meth) acrylate) A) acrylates; poly (meth) acrylates such as neopentyl glycol ester di (meth) acrylate of hydroxybivalic acid; isocyanurate type poly (meth) acrylates such as tris [(meth) acryloxyethyl] isocyanurate Is mentioned.

(Photocurable resin (cationic polymerization))
As such a photocurable resin, an alicyclic epoxy compound, an oxetane compound, a vinyl ether compound and the like can be suitably used. Among these, alicyclic epoxy compounds include 3,4,3 ′, 4′-diepoxybicyclohexyl, 2,2-bis (3,4-epoxycyclohexyl) propane, and 2,2-bis (3,4-epoxy). Cyclohexyl) -1,3-hexafluoropropane, bis (3,4-epoxycyclohexyl) methane, 1- [1,1-bis (3,4-epoxycyclohexyl)] ethylbenzene, bis (3,4-epoxycyclohexyl) Adipate, 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate, (3,4-epoxy-6-methylcyclohexyl) methyl-3 ′, 4′-epoxy-6-methylcyclohexanecarboxylate, ethylene -1,2-bis (3,4-epoxycyclohexanecarboxylic acid) ester, chic Examples thereof include alicyclic epoxy compounds having an epoxy group such as rohexene oxide, 3,4-epoxycyclohexylmethyl alcohol, and 3,4-epoxycyclohexylethyltrimethoxysilane. Examples of commercially available products include Celoxide 2000, Celoxide 2021, Celoxide 3000, and EHPE3150 manufactured by Daicel Chemical Industries, Ltd .; Epomic VG-3101 manufactured by Mitsui Chemicals, Inc .; E-1031S manufactured by Yuka Shell Epoxy Co., Ltd. ; TETRAD-X, TETRAD-C manufactured by Mitsubishi Gas Chemical Co., Ltd .; EPB-13, EPB-27 manufactured by Nippon Soda Co., Ltd., and the like.

  Examples of the oxetane compound include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, 1,4-bis [(3-methyl-3- Oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-oxetanyl) methyl acrylate In addition to polyfunctional oxetanes such as (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and oligomers or copolymers thereof, oxetane alcohol and novolak resin, poly (p -Hydroxystyrene), cardo-type bisphenols Examples include oxetane compounds such as calixarenes, calixresorcinarenes, etherification products with hydroxyl group-containing resins such as silsesquioxane, and copolymers of unsaturated monomers having an oxetane ring and alkyl (meth) acrylates. . Commercially available products include, for example, Etanacol OXBP, OXMA, OXBP, EHO, xylylene bisoxetane manufactured by Ube Industries, Ltd., Aron Oxetane OXT-101, OXT-201, XT-211, OXT manufactured by Toagosei Co., Ltd. -221, OXT-212, OXT-610, PNOX-1009, and the like.

  Examples of vinyl ether compounds include cyclic ether type vinyl ethers such as isosorbite divinyl ether and oxanorbornene divinyl ether (vinyl ethers having cyclic ether groups such as oxirane ring, oxetane ring and oxolane ring); aryl vinyl ethers such as phenyl vinyl ether; n-butyl vinyl ether Alkyl vinyl ethers such as octyl vinyl ether; cycloalkyl vinyl ethers such as cyclohexyl vinyl ether; polyfunctional vinyl ethers such as hydroquinone divinyl ether, 1,4-butanediol divinyl ether, cyclohexane divinyl ether, cyclohexane dimethanol divinyl ether, α and / or β position And vinyl ether compounds having substituents such as alkyl groups and allyl groups. The Examples of commercially available products include 2-hydroxyethyl vinyl ether (HEVE), diethylene glycol monovinyl ether (DEGV), 2-hydroxybutyl vinyl ether (HBVE), and triethylene glycol divinyl ether manufactured by Maruzen Petrochemical Co., Ltd.

  When the printed wiring board material of the present invention is used as an alkali development type photo solder resist that can be developed with an aqueous alkali solution, it is also preferable to use a carboxyl group-containing resin as a binder component.

(Carboxyl group-containing resin)
As the carboxyl group-containing resin, any of a photosensitive carboxyl group-containing resin having at least one photosensitive unsaturated double bond and a carboxyl group-containing resin having no photosensitive unsaturated double bond can be used. However, it is not limited to a specific one. As the carboxyl group-containing resin, in particular, the resins listed below can be suitably used.
(1) A carboxyl group-containing resin obtained by copolymerization of an unsaturated carboxylic acid and a compound having an unsaturated double bond, and a carboxyl group-containing resin having a molecular weight and an acid value adjusted by modifying it.
(2) A photosensitive carboxyl group-containing resin obtained by reacting a carboxyl group-containing (meth) acrylic copolymer resin with a compound having an oxirane ring and an ethylenically unsaturated group in one molecule.
(3) An unsaturated monocarboxylic acid is reacted with a copolymer of a compound having one epoxy group and an unsaturated double bond in each molecule and a compound having an unsaturated double bond, and formed by this reaction. A photosensitive carboxyl group-containing resin obtained by reacting a secondary hydroxyl group with a saturated or unsaturated polybasic acid anhydride.
(4) After reacting a hydroxyl group-containing polymer with a saturated or unsaturated polybasic acid anhydride, a compound having one epoxy group and an unsaturated double bond in each molecule of the carboxylic acid produced by this reaction. Photosensitive hydroxyl group and carboxyl group-containing resin obtained by reaction.
(5) A photosensitive carboxyl group obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid and reacting a polybasic acid anhydride with some or all of the secondary hydroxyl groups produced by this reaction. Containing resin.
(6) A polyfunctional epoxy compound is reacted with a compound having one reactive group other than a hydroxyl group that reacts with two or more hydroxyl groups and an epoxy group in one molecule, and an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting the obtained reaction product with a polybasic acid anhydride.
(7) Obtained by reacting a reaction product of a resin having a phenolic hydroxyl group with an alkylene oxide or a cyclic carbonate with an unsaturated group-containing monocarboxylic acid, and reacting the resulting reaction product with a polybasic acid anhydride. Carboxyl group-containing photosensitive resin.
(8) A reaction product obtained by reacting a polyfunctional epoxy compound, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, and an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting an anhydride group of a polybasic acid anhydride with an alcoholic hydroxyl group.

  In addition to cellulose nanofibers and binder components, other conventional compounding components can be appropriately blended with the printed wiring board material of the present invention.

  As another conventional compounding component, for example, an elastomer having a functional group can be added to the printed wiring board material of the present invention. Trade names of elastomers having functional groups include R-45HT, Poly bd HTP-9 (manufactured by Idemitsu Kosan Co., Ltd.), Epolide PB3600 (manufactured by Daicel Corporation), Denarex R-45EPT (Nagase ChemteX Corporation) Ricon 130, Ricon 131, Ricon 134, Ricon 142, Ricon 150, Ricon 152, Ricon 152, Ricon 153, Ricon 154, Ricon 156, Ricon 157, Ricon 100, Ricon 181, Ricon 184, Ricon 130MA 13013 MA8 13 , Ricon 131MA5, Ricon 131MA10, Ricon 131MA17, Ricon 131MA20, Ricon 184 A6, Ricon 156MA17 (manufactured by Sartomer Corp.) include, can be used polyester elastomer, polyurethane elastomer, polyester urethane-based elastomers, polyamide elastomers, polyester amide elastomer, acrylic elastomer, a olefinic elastomer or the like. In addition, resins in which some or all of the epoxy groups of epoxy resins having various skeletons are modified with carboxylic acid-modified butadiene-acrylonitrile rubber at both ends can be used. Furthermore, epoxy-containing polybutadiene elastomers, acrylic-containing polybutadiene elastomers, hydroxyl group-containing polybutadiene elastomers, hydroxyl group-containing isoprene elastomers, and the like can also be used. These elastomers may be used alone or in combination of two or more.

As other components, a thermosetting catalyst, a photopolymerization initiator, a colorant, and an organic solvent may be added.
The curing catalyst is mainly for curing a thermosetting resin among curable resins. For example, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2- Imidazole derivatives such as phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) Amine compounds such as -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipic acid dihydrazide, sebacic acid dihydrazide; Phosphorylation of phenylphosphine, etc. Things and the like. Examples of commercially available products include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (manufactured by Shikoku Kasei Kogyo Co., Ltd.), U-CAT3503N, U-CAT3502T, DBU, DBN, U-CATSA102, U- CAT5002 (manufactured by San Apro Co., Ltd.) and the like may be mentioned, and these may be used alone or in admixture of two or more. Similarly, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6 S-triazine derivatives such as -diamino-S-triazine / isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adduct can also be used.

  In addition, the photopolymerization initiator is for curing the photocurable resin among the curable resins, for example, benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether. Acetophenones such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone; 2-methyl -1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) ) -2-[(4-Methylphenyl) methyl Aminoalkylphenones such as -1- [4- (4-morpholinyl) phenyl] -1-butanone; anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 1-chloroanthraquinone; Thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; Ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; Benzophenones such as benzophenone; or xanthone (2,6-dimethoxybenzoyl) -2,4,4-pentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-tri Chill diphenylphosphine oxide, phosphine oxide such as ethyl 2,4,6-trimethylbenzoylphenyl phosphinate Nate; various peroxides, and the like titanocene initiators. These are photosensitized like tertiary amines such as N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine and the like. You may use together with an agent etc. These photopolymerization initiators can be used alone or in combination of two or more.

  As the colorant, a known and conventional one represented by a color index as a color pigment or dye can be used. For example, Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4 15: 6, 16, 60, Solvent Blue 35, 63, 68, 70, 83, 87, 94, 97, 122, 136 , 67, 70, Pigment Green 7, 36, 3, 5, 20, 28, Solvent Yellow 163, Pigment Yellow 24, 108, 193, 147, 199, 202, 110, 109, 139 179 185 93, 94, 95, 128, 155, 166, 180, 120, 151, 154, 156, 175, 181, 1, 2, 3, 4, 5, 6, 9, 10, 12, 61, 62, 62: 1, 65, 73, 74, 75, 97, 100, 104, 105, 111, 116, 167, 168, 169, 182 , 183, 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, 198, Pigment Orange 1, 5, 13, 14 16, 17, 24, 34, 36, 38, 40, 43, 46, 49, 51, 61, 63, 64, 71, 73, Pigment Red 1, 2, 3, 4, 5, 6, 8, 9 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 112, 114, 146, 147, 151, 170, 184, 187, 188, 193, 210, 245, 253, 258, 266 267, 268, 269, 37, 38, 41, 48: 1, 48: 2, 48: 3, 48: 4, 49: 1, 49: 2, 50: 1, 52: 1, 52: 2, 53 1,5 : 2, 57: 1, 58: 4, 63: 1, 63: 2, 64: 1, 68, 171, 175, 176, 185, 208, 123, 149, 166, 178, 179, 190, 194, 224 254, 255, 264, 270, 272, 220, 144, 166, 214, 220, 221, 242, 168, 177, 216, 122, 202, 206, 207, 209, Solvent Red 135, 179, 149, 150 , 52, 207, Pigment Violet 19, 23, 29, 32, 36, 38, 42, Solvent Violet 13, 36, Pigment Brown 23, 25, Pigment Black 1, 7, and the like.

  Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, diethylene glycol Glycol ethers such as monoethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, cellosolve acetate, diethylene glycol monoethyl ether acetate and esterified products of the above glycol ethers; Alcohols such as ethanol, propanol, ethylene glycol, propylene glycol; octa Aliphatic hydrocarbons such as decane may be mentioned petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, a petroleum solvent or the like, such as solvent naphtha.

Moreover, additives, such as a defoaming and leveling agent, a thixotropy imparting agent / thickening agent, a coupling agent, a dispersant, and a flame retardant, may be included as necessary.
Antifoaming and leveling agents include compounds such as silicone, modified silicone, mineral oil, vegetable oil, aliphatic alcohol, fatty acid, metal soap, fatty acid amide, polyoxyalkylene glycol, polyoxyalkylene alkyl ether, polyoxyalkylene fatty acid ester, etc. Etc. can be used.

  As thixotropy imparting agent / thickening agent, clay minerals such as kaolinite, smectite, montmorillonite, bentonite, talc, mica, zeolite, etc., fine silica, silica gel, amorphous inorganic particles, polyamide additives, modified urea additives, Wax-based additives can be used.

  As the coupling agent, alkoxy group is methoxy group, ethoxy group, acetyl, etc., and reactive functional group is vinyl, methacryl, acrylic, epoxy, cyclic epoxy, mercapto, amino, diamino, acid anhydride, ureido, sulfide, Isocyanates and the like, for example, vinyl silane compounds such as vinyl ethoxylane, vinyl trimethoxysilane, vinyl tris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxylane, γ-aminopropyltrimethoxylane,系 -β- (aminoethyl) γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropylmethyldimethoxysilane, amino-based silane compounds such as γ-ureidopropyltriethoxysilane, and γ-glycid Xipropyltrimethoxy Epoxy silane compounds such as silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxylane, γ-glycidoxypropylmethyldiethoxysilane, mercapto silane compounds such as γ-mercaptopropyltrimethoxysilane, Silane coupling agents such as phenylamino silane compounds such as phenyl-γ-aminopropyltrimethoxysilane, isopropyl triisostearoylated titanate, tetraoctyl bis (ditridecyl phosphite) titanate, bis (dioctyl pyrophosphate) oxyacetate titanate , Isopropyltridodecylbenzenesulfonyl titanate, isopropyltris (dioctylpyrophosphate) titanate, tetraisopropylbis (dioctylphosphite) titanate, La (1,1-diallyloxymethyl-1-butyl) bis- (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl titanate, isopropyltristearoyl diacryl Titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, dicumylphenyloxyacetate titanate, diisostearoyl ethylene titanate, etc., ethylenically unsaturated zirconate-containing compound, neoalkoxy zirconate-containing compound , Neoalkoxytris neodecanoyl zirconate, neoalkoxytris (dodecyl) benzenes Lulphonyl zirconate, neoalkoxy tris (dioctyl) phosphate zirconate, neoalkoxy tris (dioctyl) pyrophosphate zirconate, neoalkoxy tris (ethylenediamino) ethyl zirconate, neoalkoxy tris (m-amino) phenyl zirconate, tetra (2,2-diallyloxymethyl) butyl, di (ditridecyl) phosphito zirconate, neopentyl (diallyl) oxy, trineodecanoyl zirconate, neopentyl (diallyl) oxy, tri (dodecyl) benzene-sulfonyl zirconate, neopentyl (Diallyl) oxy, tri (dioctyl) phosphatozirconate, neopentyl (diallyl) oxy, tri (dioctyl) pyro-phosphatozirconate, neopentyl (di Ryl) oxy, tri (N-ethylenediamino) ethyl zirconate, neopentyl (diallyl) oxy, tri (m-amino) phenyl zirconate, neopentyl (diallyl) oxy, trimethacryl zirconate, neopentyl (diallyl) oxy, triacryl Zirconate, dineopentyl (diallyl) oxy, diparaaminobenzoyl zirconate, dineopentyl (diallyl) oxy, di (3-mercapto) propionic zirconate, zirconium (IV) 2,2-bis (2-propenolatomethyl) Zirconate coupling agents such as butanolato, cyclodi [2,2- (bis-2-propenolatomethyl) butanolato] pyrophosphato-O, O, diisobutyl (oleyl) acetoacetylaluminate, alkylacetoacetate Diisopropylate aluminate coupling agents such like.

  Dispersants include polycarboxylic acid-based, naphthalene sulfonic acid formalin condensation-based, polyethylene glycol, polycarboxylic acid partial alkyl ester-based, polyether-based, polyalkylene polyamine-based polymeric dispersants, alkyl sulfonic acid-based, four Low molecular weight dispersants such as secondary ammonium series, higher alcohol alkylene oxide series, polyhydric alcohol ester series and alkylpolyamine series can be used.

  Flame retardants include hydrated metal such as aluminum hydroxide and magnesium hydroxide, red phosphorus, ammonium phosphate, ammonium carbonate, zinc borate, zinc stannate, molybdenum compound, bromine compound, chlorine compound, phosphate ester Phosphorus-containing polyol, phosphorus-containing amine, melamine cyanurate, melamine compound, triazine compound, guanidine compound, silicon polymer, and the like can be used.

  Other ingredients include photoacid generators such as diazonium salts, sulfonium salts, iodonium salts, photobase generators such as carbamate compounds, α-aminoketone compounds, O-acyloxime compounds, barium sulfate, spherical silica, hydrotalcite. And inorganic fillers such as silicon powder, nylon powder and fluorine powder, radical scavengers, ultraviolet absorbers, antioxidants, peroxide decomposers, adhesion promoters, rust inhibitors and the like.

  The printed wiring board material according to the present invention having the configuration as described above can be suitably used for the solder resist and the core material, and can be suitably used for the interlayer insulating material of the multilayer printed wiring board, Thereby, in the obtained printed wiring board, the expected effect of the present invention can be obtained. Furthermore, when the present invention is applied to a printed wiring board material, for example, there is a method of forming a prepreg by forming the cellulose nanofibers into a sheet shape, impregnating the sheet-like cellulose nanofibers with a binder component, and drying. Can be used.

  FIG. 1 is a partial cross-sectional view showing a configuration example of a multilayer printed wiring board according to the present invention. The illustrated multilayer printed wiring board can be manufactured, for example, as follows. First, a through hole is formed in the core substrate 2 on which the conductor pattern 1 is formed. The through hole can be formed by an appropriate means such as a drill, a die punch, or laser light. Then, a roughening process is performed using a roughening agent. Generally, the roughening treatment is performed by swelling with an organic solvent such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, methoxypropanol, or an alkaline aqueous solution such as caustic soda or caustic potash, and then dichromate and permanganic acid. It is carried out using an oxidizing agent such as salt, ozone, hydrogen peroxide / sulfuric acid or nitric acid.

  Next, the conductor pattern 3 is formed by a combination of electroless plating or electrolytic plating. The step of forming the conductor layer by electroless plating is a step of immersing in an aqueous solution containing a plating catalyst, adsorbing the catalyst, and then immersing in a plating solution to deposit the plating. A predetermined circuit pattern is formed on the conductor layer on the surface of the core substrate 2 in accordance with a conventional method (subtractive method, semi-additive method, etc.), and a conductor pattern 3 is formed on both sides as shown. At this time, a plated layer is also formed in the through hole, and as a result, the connection portion 4 of the conductor pattern 3 of the multilayer printed wiring board and the connection portion 1a of the conductor pattern 1 are electrically connected. Through hole 5 is formed.

  Next, for example, after applying a thermosetting composition by an appropriate method such as a screen printing method, a spray coating method, or a curtain coating method, the interlayer insulating layer 6 is formed by heating and curing. When a dry film or prepreg is used, the interlayer insulating layer 6 is formed by laminating or hot plate pressing and heat curing. Next, vias 7 for electrically connecting the connection portions of the conductor layers are formed by appropriate means such as laser light, and the conductor pattern 8 is formed by the same method as the conductor pattern 3. Further, the interlayer insulating layer 9, the via 10 and the conductor pattern 11 are formed by the same method. Then, a multilayer printed wiring board is manufactured by forming the solder resist layer 12 in the outermost layer. In the above, the example in which the interlayer insulating layer and the conductor layer are formed on the multilayer substrate has been described. However, a single-sided substrate or a double-sided substrate may be used instead of the multilayer substrate.

Hereinafter, the present invention will be described in more detail with reference to examples. In addition, all the numbers in the following table | surfaces show a mass part.
[Production of Cellulose Nanofiber Dispersion Having Carboxylate]
(Production Example 1)
2, 2, 6, 6 -Tetramethylpiperidine-N-oxyl (TEMPO) 79 mg (0.5 mmol) and sodium bromide 515 mg (5 mmol) were added to 500 ml of an aqueous solution and stirred until the pulp was uniformly dispersed. To this, 18 ml of an aqueous sodium hypochlorite solution containing 5% effective chlorine was added, the pH was adjusted to 10 with an aqueous 0.5N hydrochloric acid solution, and an oxidation reaction was started. During the reaction, the pH in the system was lowered, but a 0.5N aqueous sodium hydroxide solution was successively added to adjust the pH to 10. After the reaction for 2 hours, the mixture was filtered through a glass filter, and the residue was sufficiently washed with water to obtain a reaction product.

  Next, distilled water was added to the reaction product to obtain an aqueous dispersion having a pulp concentration of 2% by mass, and the mixture was stirred and dispersed with a rotary blade mixer for 5 minutes. Since the viscosity of the slurry significantly increased with stirring, distilled water was added little by little, and stirring and dispersion with a mixer was continued until the solid content concentration reached 0.2% by mass to obtain a transparent gelled aqueous solution. This was observed with TEM and confirmed to be an aqueous dispersion of cellulose nanofibers having a carboxylate having a number average fiber diameter of 10 nm. The amount of carboxyl groups in the aqueous dispersion was 1.25 mmol / g.

  This was subjected to dehydration filtration, 10 times the amount of carbitol acetate as the weight of the filtrate was added, and the mixture was stirred for 30 minutes and then filtered. This substitution operation was repeated three times to add 10 times the amount of carbitol acetate as the weight of the filtrate to prepare cellulose nanofiber dispersion 1 having 10% by mass of carboxylate.

(Production Example 2)
Instead of 79 mg (0.5 mmol) of 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), 4-dimethylamino-2,2,6,6-tetramethylpiperidine-N-oxyl (4- A cellulose nanofiber dispersion 2 having 10% by mass of a carboxylate was produced in the same manner as in Production Example 1 except that 100 mg (0.5 mmol) of (dimethylamino-TEMPO) was used. The amount of carboxyl groups in the aqueous dispersion was 1.30 mmol / g, and the number average fiber diameter of the cellulose nanofibers having a carboxylate salt was 12 nm.

(Production Example 3)
Instead of 79 mg (0.5 mmol) of 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), 4-carboxy-2,2,6,6-tetramethylpiperidine-N-oxyl (4-carboxyl) -TEMPO) A cellulose nanofiber dispersion 3 having 10% by mass of a carboxylate was prepared in the same manner as in Production Example 1 except that 101 mg (0.5 mmol) was used. The amount of carboxyl groups in the aqueous dispersion was 1.16 mmol / g, and the number average fiber diameter of the cellulose nanofibers having a carboxylate salt was 10 nm.

[Production of cellulose nanofiber dispersion]
(Production Example 4)
A plate made of eucalyptus was pulverized using a cutter mill to produce a wood powder of about 0.2 mm square. Next, this wood flour was subjected to high-temperature and high-pressure treatment in an aqueous solution such as sodium sulfite and sodium hydroxide to remove lignin. 50 times distilled water was added and stirred, and after mechanical pulverization using a disk mill 15 times, distilled water was added and stirred to 10% by mass, and cellulose nanofibers having a number average fiber diameter of 80 nm Got. This was subjected to dehydration filtration, 10 times the amount of carbitol acetate as the weight of the filtrate was added, and the mixture was stirred for 30 minutes and then filtered. This replacement operation was repeated three times, and 10 times the weight of the filtrate was added with carbitol acetate to prepare a 10% by mass cellulose nanofiber dispersion 1.

* 1) Thermosetting compound 1: Epicote 828, manufactured by Mitsubishi Chemical Corporation * 2) Thermosetting compound 2: Epicote 807, manufactured by Mitsubishi Chemical Corporation * 3) Curing catalyst 1: 2MZ-A Shikoku Chemicals Co., Ltd. * 4) Colorant: Phthalocyanine Blue
* 5) Organic solvent: carbitol acetate

* 6) Thermosetting compound 3: Unidic V-8000 manufactured by DIC Corporation (solid content 40% by mass)
* 7) Thermosetting compound 4: Denacol EX-830 manufactured by Nagase ChemteX Corporation * 8) Curing catalyst 2: Triphenylphosphine

* 9) Thermoplastic resin 1: Socsea SOXR-OB Varnish manufactured by Nippon Kogyo Paper Industries Co., Ltd. (solid content 70% by mass, N-methylpyrrolidone 30% by mass)

* 10) Photocurable compound 1: Bisphenol A type epoxy acrylate Mitsubishi Chemical Co., Ltd. * 11) Photocurable compound 2: Trimethylolpropane triacrylate * 12) Photocurable compound 3: Kayamar PM2 Nippon Kayaku Co., Ltd. * 13) Photocurable compound 4: Light ester HO Kyoeisha Chemical Co., Ltd. * 14) Photopolymerization initiator 1: 2-ethylanthraquinone

[Synthesis example 1 of carboxyl group-containing resin]
(Varnish 1)
In a 2 liter separable flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen introduction tube, 900 g of diethylene glycol dimethyl ether as a solvent and t-butylperoxy 2-ethylhexanoate as a polymerization initiator 21.4 g (manufactured by NOF Corporation, trade name: Perbutyl O) was added and heated to 90 ° C. After heating, 309.9 g of methacrylic acid, 116.4 g of methyl methacrylate, and 109.8 g of lactone-modified 2-hydroxyethyl methacrylate (manufactured by Daicel Corporation, trade name: Plaxel FM1) were used as a polymerization initiator. Bis (4-t-butylcyclohexyl) peroxydicarbonate (manufactured by NOF Corporation, trade name: Parroyl TCP) was added dropwise over 3 hours. Further, this was aged for 6 hours to obtain a carboxyl group-containing copolymer resin. These reactions were performed in a nitrogen atmosphere.

  Next, to the obtained carboxyl group-containing copolymer resin, 363.9 g of 3,4-epoxycyclohexylmethyl acrylate (manufactured by Daicel Corporation, trade name: Cyclomer A200), 3. dimethylbenzylamine as a ring-opening catalyst; 6 g and 1.80 g of hydroquinone monomethyl ether as a polymerization inhibitor were added, heated to 100 ° C., and stirred to carry out an epoxy ring-opening addition reaction. After 16 hours, a solution containing 53.8% by mass (nonvolatile content) of a carboxyl group-containing resin having a solid acid value of 108.9 mgKOH / g and a weight average molecular weight of 25,000 was obtained.

[Synthesis example 2 of carboxyl group-containing resin]
(Varnish 2)
In a flask equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser, diethylene glycol monoethyl ether acetate as a solvent and azobisisobutyronitrile as a catalyst were placed and heated to 80 ° C. in a nitrogen atmosphere. A monomer in which methacrylic acid and methyl methacrylate were mixed at a molar ratio of 0.40: 0.60 was dropped over about 2 hours. Furthermore, after stirring this for 1 hour, the temperature was raised to 115 ° C. and deactivated to obtain a resin solution. After cooling the resin solution, tetrabutylammonium bromide was used as a catalyst, and butyl glycidyl ether was added at a molar ratio of 0.40 at 95 to 105 ° C. for 30 hours. Addition reaction with an equal volume and cooling.

  Furthermore, tetrahydrophthalic anhydride was subjected to addition reaction at a molar ratio of 0.26 under the condition of 95 to 105 ° C. for 8 hours with respect to the OH group of the resin obtained above. This was taken out after cooling to obtain a solution containing 50% by mass (nonvolatile content) of a carboxyl group-containing resin having a solid acid value of 78.1 mgKOH / g and a mass average molecular weight of 35,000.

[Synthesis Example 3 of carboxyl group-containing resin]
(Varnish 3)
In a flask equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser, 210 g of cresol novolac type epoxy resin (DIC Corporation, Epicron N-680, epoxy equivalent = 210) and carbitol acetate 96 as a solvent .4 g was added and dissolved by heating. Subsequently, 0.1 g of hydroquinone as a polymerization inhibitor and 2.0 g of triphenylphosphine as a reaction catalyst were added thereto. This mixture was heated to 95 to 105 ° C., 72 g of acrylic acid was gradually added dropwise, and the mixture was reacted for about 16 hours until the acid value became 3.0 mgKOH / g or less. The reaction product was cooled to 80 to 90 ° C., 76.1 g of tetrahydrophthalic anhydride was added, and about 6 until an absorption peak (1780 cm ⁻¹ ) of the acid anhydride disappeared by infrared absorption analysis. Reacted for hours. To this reaction solution, 96.4 g of aromatic solvent ipsol # 150 manufactured by Idemitsu Kosan Co., Ltd. was added, diluted, and then taken out. The thus obtained carboxyl group-containing photosensitive polymer solution had a nonvolatile content of 65 mass% and a solid content acid value of 78 mgKOH / g.

* 15) Curing catalyst 3: Finely pulverized melamine * 16) Curing catalyst 4: Dicyandiamide * 17) Photopolymerization initiator 2: Irgacure 907 manufactured by BASF * 18) Photocurable compound 5: Dipentaerythritol tetra Acrylate * 19) Thermosetting compound 5: TEPIC-H manufactured by Nissan Chemical Co., Ltd.

[Production of sheet for evaluation of breaking strength and breaking elongation]
In accordance with the description in Table 1 above, each component was blended, stirred, and dispersed with a three roll to prepare each composition. Next, this composition was printed on a copper foil having a thickness of 18 μm on the entire surface by a screen printing method, and cured in a hot air circulation type drying furnace at 140 ° C. for 30 minutes. Thereafter, the copper foil was removed to prepare an evaluation sheet having a thickness of 50 μm.

  In accordance with the description in Table 2 above, each component was blended, stirred, and dispersed by a three roll to prepare each composition. Next, this composition was printed on a copper foil having a thickness of 18 μm on the entire surface by a screen printing method, dried in a hot air circulation drying oven at 100 ° C. for 30 minutes, and then at 170 ° C. for 60 minutes. And cured. Thereafter, the copper foil was removed to prepare an evaluation sheet having a thickness of 50 μm.

  In accordance with the description in Table 3 above, each component was blended, stirred, and dispersed by a three roll to prepare each composition. Next, this composition was printed on a copper foil having a thickness of 18 μm on the entire surface by a screen printing method, dried in a hot air circulating drying oven at 120 ° C. for 10 minutes, and then at 250 ° C. for 30 minutes. And cured. Thereafter, the copper foil was removed to prepare an evaluation sheet having a thickness of 50 μm.

In accordance with the description in Table 4 above, each component was blended, stirred, and dispersed with three rolls to prepare each composition. Next, this composition was printed on a copper foil having a thickness of 18 μm on the entire surface by a screen printing method, and cured by irradiating an integrated light amount of ² J / cm ² at a wavelength of 350 nm with a metal halide lamp. Thereafter, the copper foil was removed to prepare an evaluation sheet having a thickness of 50 μm.

According to the description in Tables 5 to 7, the respective components were blended, stirred, and dispersed by a three roll to prepare each composition. Next, this composition was printed on a copper foil having a thickness of 18 μm on the entire surface by a screen printing method, and dried at 80 ° C. for 30 minutes in a hot air circulation drying furnace. Next, using a negative pattern that can cover the center of the copper foil, the printed wiring board exposure machine HMW-680GW (manufactured by Oak Manufacturing Co., Ltd.) is exposed with an integrated light amount of 700 mJ / cm ² and 1% at 30 ° C. The aqueous sodium carbonate solution was developed for 60 seconds with a developing machine for printed wiring boards, and the copper foil edge was removed. Subsequently, it was cured at 150 ° C. for 60 minutes in a hot air circulating drying oven. Thereafter, the copper foil was removed to prepare an evaluation sheet having a thickness of 50 μm.

[Evaluation of breaking strength and breaking elongation]
Based on JIS K7127, the said evaluation sheet | seat was cut | judged to the predetermined magnitude | size, and the test piece was produced. After measuring the breaking strength [MPa] and the breaking elongation [%] at a tensile speed of 10 mm / min using a tensile testing machine (AGS-G manufactured by Shimadzu Corporation), the test piece was subjected to the following evaluation criteria. Based on the evaluation. The results are shown in Tables 8 to 11 below. In the evaluation criteria of the breaking strength and breaking elongation, when both are good, it can be seen that the cured product of the test piece has high toughness and excellent crack resistance.

(Evaluation criteria for breaking strength)
○: 75 MPa or more Δ: 50 MPa or more and less than 75 MPa x: less than 50 MPa (Evaluation criteria for breaking elongation)
○: 6% or more Δ: 4% or more and less than 6% ×: less than 4%

[Preparation of crack resistance evaluation substrate]
In preparation of the said breaking strength and breaking elongation evaluation sheet | seat, it used the FR-4 copper clad laminated board (copper thickness 18 micrometers) with a thickness of 1.6 mm instead of copper foil, and obtained the hardened | cured material with a film thickness of 20 micrometers. Went through the same steps to produce an evaluation substrate having a cured product formed on a copper-clad laminate.

[Evaluation of crack resistance]
The evaluation substrate was given a temperature history of 1000 cycles with -65 ° C. for 30 minutes and 150 ° C. for 30 minutes as one cycle, and the degree of cracking and peeling of the evaluation substrate thereafter was measured with an optical microscope (Corporation). Observation was performed by VHX-2000) manufactured by Keyence, and evaluation was performed based on the following evaluation criteria. The results are shown in Tables 8 to 11 below.
(Evaluation criteria)
○: No crack is generated Δ: Crack is generated ×: Crack is significantly generated

  As described above in detail, it was confirmed that the crack resistance can be improved by using a printed wiring board material containing cellulose nanofibers having a carboxylate.

1, 3, 8, 11 Conductor pattern 2 Core substrate 1a, 4 Connection portion 5 Through hole 6, 9 Interlayer insulating layer 7, 10 Via 12 Solder resist layer

Claims (8)

  A printed wiring board material comprising a binder component and cellulose nanofibers having a number average fiber diameter of 3 nm to 1000 nm having a carboxylate in the structure.   The cellulose nanofiber is obtained by using natural cellulose fiber as a raw material, and oxidizing the natural cellulose fiber in water using an N-oxyl compound as an oxidation catalyst and a co-oxidant acting. The printed wiring board material according to 1.   The printed wiring board material according to claim 1, wherein the binder component is a thermoplastic resin.   The printed wiring board material according to claim 1, wherein the binder component is a curable resin.   It is for soldering resists, The printed wiring board material as described in any one of Claims 1-4.   It is for core materials, The printed wiring board material as described in any one of Claims 1-4.   The printed wiring board material according to any one of claims 1 to 4, which is used for an interlayer insulating material of a multilayer printed wiring board.   A printed wiring board comprising the printed wiring board material according to claim 1.