JP2010254773A - Electron beam-curable or ultraviolet ray-curable ink binder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photo-curable ink binder exhibiting improved resolution through a curing reaction by irradiation with electron beams or UV rays, and having excellent low curing shrinkage. <P>SOLUTION: The photo-curable ink binder contains a urethane resin as a film-forming component, which is obtained by reacting a compound (a) having both of a hydroxy group and an alkali-soluble group in the molecule with a compound (b) having both of a hydroxy group and a vinyl group in the molecule, a polycarbonate polyol (c) and a polyisocyanate (d). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink binder that is cured by an electron beam or ultraviolet rays. More specifically, the present invention relates to a binder for an alkali development type solder resist ink and an ink binder used for a photosensitive film.

  The ink binder of the present invention has a high resolution, alkali detergency, heat resistance, water resistance, adhesion to a substrate, chemical resistance, electrical insulation, etc. by a curing reaction by electron beam irradiation or ultraviolet irradiation. It is an ink binder that is improved and further excellent in non-chlorine materials, low curing shrinkage, flexibility, high elongation and processability. Of course, it is also one of the features that the binder for ink is tack-free before electron beam irradiation or ultraviolet irradiation (before curing reaction).

  Conventionally, a solder resist ink is used as an insulating protective film that covers the surface of a printed wiring board and protects the circuit pattern. As the insulating protective film, the circuit pattern is protected from dust, heat, moisture, and the like, and a short circuit is prevented. It is used for that purpose.

  The specifications required for solder resist ink include printability, film formability, high resolution, chemical resistance, (solder) heat resistance, adhesion to the substrate, hardness, electrical insulation, water resistance (moisture resistance), Examples include low migration and impact resistance.

  In addition, the process of the alkali development type solder resist is such that after the solder resist is printed and applied to the substrate on which the circuit pattern is formed, it is exposed through a negative film (the exposed solder resist portion is cured), and an uncured portion with an alkali developer. In general, a solder resist pattern is formed by cleaning the substrate.

  In recent years, with the advancement of digitalization, the demand for miniaturization, thinning, and weight reduction has become stronger as electronic devices have higher functionality and downsizing. For this reason, circuit patterns on printed wiring boards by downsizing electronic devices have been made thinner and finer, and the weight and thickness of substrates have been reduced. The insulating protective film protects the circuit pattern from the external environment such as dust, heat and moisture, and operates the electronic apparatus stably. Furthermore, the insulating protective film is required to have a material that has little shrinkage in curing and does not warp when it is thinned, and has flexibility for a flexible wiring board.

  The thickness of the circuit pattern of the general-purpose substrate is about 50 to 200 μm, whereas the package substrate tends to be thinned, and there are many cases where molding of 20 to 50 μm or less is desired.

  A material for forming such a solder resist film is obtained by reacting a (meth) acrylate compound having two carboxyl groups in one molecule with an epoxy compound having two epoxy groups in one molecule. A photosensitive resin composition containing an unsaturated group-containing polycarboxylic acid resin compound and a diluent has been proposed.

  The photosensitive resin composition mainly composed of the unsaturated group-containing polycarboxylic acid resin compound and the diluent has a problem that the shrinkage of the curing is large and the substrate is warped in the case of a thin substrate when cured. (Patent Document 1).

Moreover, a thermosetting resin composition containing a polyurethane resin obtained by reacting two or more carboxyl groups, polycarbonate diol and polyisocyanate and an epoxy component has been proposed as a solder resist film. In such a thermosetting system, since the reaction is performed at a high temperature for a long time, a large amount of CO ₂ is generated in the production process, which is not preferable in terms of environmental load. In addition, a product in which the amount of outgas increases due to the presence of unreacted substances and low molecular weight impurities is not preferable (Patent Document 2).

  Although the hardened | cured material which consists of said composition is excellent in the heat resistance and moisture resistance as a soldering resist film, it is inferior to flexibility and a softness | flexibility. When a solder resist film is formed on a thin printed wiring board or an FPC board, there arises a problem that the board is warped or twisted. In addition, in the case of a hard solder resist film, cracks occur in the hardened film due to external impacts, and solder adheres to unnecessary parts when mounting parts, and insulation between conductors deteriorates and corrodes. In some cases, the reliability decreases.

JP 2001-048945 A JP 2006-117922 A

  Therefore, the object of the present invention is to solve the above-mentioned problems, and to cure by electron beam irradiation or ultraviolet irradiation to achieve high resolution, alkali cleaning properties, heat resistance, water resistance, adhesion to substrates, chemical resistance and electrical insulation. It is to provide a binder for an electron beam curable ink or an ultraviolet curable ink which has improved properties and is excellent in non-chlorine materials, low curing shrinkage, flexibility, high elongation and workability.

  The above object is achieved by the present invention described below. That is, the present invention provides a compound (a) having both at least one active hydrogen-containing group and at least one alkali-soluble group (anionic group) in the molecule (hereinafter sometimes simply referred to as “compound a”). A compound (b) having both at least one active hydrogen-containing group and a vinyl group (unsaturated bond group) in the molecule (hereinafter sometimes simply referred to as “compound b”), and a polycarbonate-based polyol (c) (Hereinafter sometimes simply referred to as “compound c”) and polyisocyanate (d) (hereinafter sometimes simply referred to as “compound d”) are combined with the total active hydrogen and the total of compounds (a) to (c). A urethane resin having at least an alkali-soluble group and a vinyl group in the same molecule, obtained by reacting the isocyanate group of (d) with NCO / OH = 0.8 to 1.1 mol. Electron beam-curable or ultraviolet-curable, characterized in that it contains as component (including LED curing) (hereinafter sometimes referred to as "photocurable") provides ink binder.

In the said invention, it is preferable that the said compound (a) is dimethylol butanoic acid and / or dimethylol propanoic acid; and the said compound (c) is a compound represented by a following formula.

  In the said invention, the usage-amount of the said compound (a) is 0.01-30 mass%, the usage-amount of the said compound (b) is 0.01-30 mass%, and the usage-amount of the said compound (c) is 10. -80% by mass, the amount of the compound (d) used is such that the equivalent ratio of the total active hydrogen of the compounds (a) to (c) to the isocyanate group of the compound (d) is 0.8 to 1.1. And the number average molecular weight is 2,000 to 500,000; it is preferable that it further contains an electron beam curable, ultraviolet curable or thermosetting monofunctional monomer, polyfunctional monomer or oligomer.

  The film comprising the ink binder of the present invention has high resolution, alkali detergency, heat resistance, water resistance, adhesion to the substrate, chemical resistance and electrical insulation, non-chlorine material, low curing shrinkage, flexibility, High elongation, workability, etc. are greatly improved, and the problems of the prior art are solved.

  In addition, the ink binder of the present invention is used for the hard substrate and flexible substrate in the photoresist-related field, and includes negative resist (including pigment dispersion ink for color filters), photosensitive film (dry film resist, photosensitive cover). Ray film), solder resist, base film, etc. In addition, it is also effective for optical fiber coating materials, stereolithography materials, mems materials, UV curable nanoprints, and organic-inorganic hybrid materials.

  In other coating applications, wood paint and building material paint such as flooring, automotive lamps (head lamps, reflectors, lenses, etc.), DVD disks, LCD panels, mobile phones, light electrical components, game machines, metal parts It is also possible to develop office equipment and cosmetic containers. In the printing field, in addition to offset printing, gravure printing, screen printing, and digital printing, it is also effective as a binder for UV curable inkjet ink and an image receiving layer that is cured simultaneously with UV inkjet ink curing. In addition, various high-performance paints (for example, automotive paints, automotive repair paints, can paints, leather paints, etc.), various high-performance coating agents (for example, various film coating agents, isocyanate-based crosslinking agents and dual curable additives) Decorative film coating agents, vacuum-formed sheets, paper coating agents, etc.), filler dispersion paints (electromagnetic wave shielding materials, etc.), flexible circuit overcoat resins, thermosetting solder resists and interlayer insulation with excellent insulation properties It can be used in fields such as electrical insulating materials such as films, IC and VLSI sealing materials, and laminates.

  Next, the present invention will be described in more detail with reference to the best mode for carrying out the invention. The photocurable urethane resin used in the present invention (hereinafter sometimes simply referred to as “resin of the present invention”) includes compound a (at least one alkali-soluble group is, for example, a carboxyl group or a sulfonic acid group) and Compound b, Compound c, and optionally, a chain extender and Compound d are obtained.

  In the above, compound a to d are used in an amount of 0.01 to 30% by mass, preferably 1 to 15% by mass of compound a, 0.01 to 30% by mass of compound b, preferably 1 to 15% by mass, and compound. c is 10 to 80% by mass, preferably 20 to 70% by mass, and the compound d has an equivalent ratio of the total active hydrogen of the compounds a to c and the isocyanate group of the compound d of 0.8 to 1.1. The amount is preferably 0.85 to 1.0. In addition, the said compounds ac are used in the ratio which the total amount of compound ac is 100 mass% within the said range.

  In the resin of the present invention, the content of the segment a composed of the compound a is preferably 0.01 to 30% by mass when the entire resin is 100% by mass. More preferably, it is 1-15 mass%. If the content is less than 0.01% by mass, it is insufficient in terms of alkali cleaning properties and adhesion to the substrate. On the other hand, if the content exceeds 30% by mass, the water resistance of the resin is reduced. Causing the formation film to be hard and causing a decrease in impact resistance. Moreover, it is preferable that content of the segment b which consists of the said compound b when the whole resin is 100 mass% is 0.01-30 mass%. More preferably, it is 1-15 mass%. When the content is less than 0.01% by mass, the film does not have the desired film performance when it is irradiated with an electron beam or ultraviolet light to undergo intramolecular / intermolecular crosslinking or a curing reaction with a crosslinking agent. If it exceeds 30% by mass, the crosslink density increases, the substrate warps due to curing shrinkage, cracks occur in the coating, and rust may occur due to moisture from the shorted or cracked location.

  In addition, content of the said segments ac is made into the ratio from which the total amount of compound ac is 100 mass% within the said range. The number average molecular weight (GPC measurement, standard polystyrene conversion) of the resin is preferably 2,000 to 500,000. More preferably, it is 5,000-200,000. If the molecular weight is less than 2,000, the resin has tack (must be tack-free) and insufficient in terms of water resistance and heat resistance. On the other hand, if the molecular weight exceeds 500,000, When the resin of the present invention is converted into an ink binder, the coating suitability as an ink binder is inferior, and the coating is poorly cured.

  As said compound a, compounds, such as a sulfonic acid type, a carboxylic acid type, and a phosphoric acid type, can be used. The main purpose of the compound a is to improve the alkali detergency in the resin of the present invention, but it improves the effect of imparting adhesion to the substrate, the effect of imparting dispersibility of the pigment, the effect of imparting film formability and the film toughness Give function.

Examples of the sulfonic acid compound a include the following compounds and derivatives thereof.

  Further, as the carboxylic acid-based compound a, dimethylolpropanoic acid, dimethylolbutanoic acid and their alkylene oxide low-mole adducts (number average molecular weight less than 500), and γ-caprolactone low-mole adducts of these compounds (several numbers) (Average molecular weight less than 500), half esters derived from acid anhydride and glycerin, compounds derived from free radical reaction of monomers containing hydroxyl and unsaturated groups and monomers containing carboxyl and unsaturated groups, etc. Is mentioned. Particularly preferred compounds a are dimethylolpropanoic acid, dimethylolbutanoic acid, N, N-bis (2-hydroxyethyl) -2-aminosulfonic acid. The amount of these compounds used is preferably such that the acid value range of the resulting polyurethane resin is 5 to 60 mgKOH / g.

  The above are examples of the preferred compound a used in the present invention, and the present invention is not limited to these exemplified compounds. Accordingly, not only the exemplified compounds described above but also any other compound a that is currently commercially available and can be easily obtained from the market can be used in the present invention.

  In use, the resin of the present invention containing the segment a of the compound a may be partially neutralized in order to facilitate alkali washing after exposure. When segment a of compound a is anionic (sulfonic acid, carboxylic acid, etc.), for example, organic amines (ammonia, ethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N -Methyldiethanolamine, N-phenyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, N-methylmorpholine, 2-amino-2-ethyl-1-propanol, etc., alkali metals (lithium, potassium, sodium) Etc.) and inorganic alkalis (lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.).

  The compound b is not particularly limited, and one or more of known compounds can be used. For example, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycerol monoallyl ether, trimethylolpropane diallyl ether, pentaerythritol triallyl ether, glycerol Examples include monomethacrylate. A preferred compound is a compound having one unsaturated group and two hydroxyl groups. Particularly preferred compounds are glycerin monoallyl ether and glycerin monomethacrylate, and it is preferred to use a compound from which the chlorine component derived from the raw material of the compound is removed.

  Examples of the compound having an amino group and an unsaturated group in the same molecule include allylamine, diallylamine, N, N′-methylenebisacrylamide, N-methylacrylamide, diacetone acrylamide, N-methylolacrylamide, 2- Examples include acrylamido-2-methylpropanesulfonic acid.

The compound c is a polycarbonate-based polyol. Although the preferable compound c is illustrated below, this invention is not limited to these exemplary compounds.
(1) Polyalkylene carbonate (a-1)

(2) Polyalkylene carbonate (a-2)

(3) Polyalkylene carbonate (a-3)

(4) Polyalkylene carbonate (a-4)

The compound c can be used in combination with other polyols. The polymer polyols that can be used in combination are shown below.
(5) Polyether polyols such as those obtained by polymerizing or copolymerizing alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) and / or heterocyclic ethers (tetrahydrofuran, etc.) are specifically exemplified. Are polyethylene glycol, polypropylene glycol, polyethylene glycol-polytetramethylene glycol (block or random), polytetramethylene ether glycol and polyhexamethylene glycol,

(6) Polyester polyols such as aliphatic dicarboxylic acids (eg succinic acid, adipic acid, sebacic acid, glutaric acid and azelaic acid) and / or aromatic dicarboxylic acids (eg isophthalic acid and terephthalic acid) And low molecular weight glycols (for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,6-hexamethylene glycol, neopentyl glycol) And 1,4-bishydroxymethylcyclohexane) and the like, specifically, polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyneopentyl adipate di Lumpur, polyethylene / butylene adipate diol, polyneopentyl / hexyl adipate diol, poly-3-methylpentane adipate diol, and polybutylene isophthalate diol, etc.,

(7) Polylactone polyol, such as polycaprolactone diol and poly-3-methylvalerolactone diol,
(8) Polyolefin polyol, such as polybutadiene glycol and polyisoprene glycol, or a hydride thereof,
(9) Polymethacrylate diols such as α, ω-polymethylmethacrylate diol and α, ω-polybutylmethacrylate diol are exemplified.

  The structure and molecular weight of these polyols are not particularly limited, but usually the number average molecular weight is preferably about 500 to 4,000, and these polyols can be used alone or in combination of two or more. However, polyurethane resins using ether polyols have poor heat resistance, and compounds containing ethylene oxide have high hydrophilicity and lower water resistance. Polyurethane resins using polyester polyols have the disadvantage of poor hydrolysis resistance. On the other hand, a polyurethane resin using a polycarbonate-based polyol has the highest heat resistance, water resistance and hydrolysis resistance, has durability against the external environment, and is most preferable as a polymer polyol to be used.

  In the present invention, a chain extender can be used as necessary in addition to the compounds a to c. Examples of the short-chain diol as the chain extender include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, and 1,6-hexamethylene. Aliphatic glycols such as glycol and neopentyl glycol and their alkylene oxide low molar adducts (number average molecular weight less than 500), fats such as 1,4-bishydroxymethylcyclohexane and 2-methyl-1,1-cyclohexanedimethanol Examples include cyclic glycols and alkylene oxide low-mole adducts thereof (number average molecular weight less than 500), aromatic glycols such as xylylene glycol, and alkylene oxide low-mole adducts thereof (number average molecular weight less than 500). It is done.

  Examples of the polyhydric alcohol compound include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, tris- (2-hydroxyethyl) isocyanurate, 1,1,1-trimethylolethane, and 1,1, Examples thereof include 1-trimethylolpropane. These can be used alone or in combination of two or more.

  Examples of polyamines include short chain diamines, aliphatic, aromatic diamines, long chain diamines, and hydrazines. Examples of the short-chain diamine include aliphatic diamine compounds such as ethylene diamine, trimethylene diamine, hexamethylene diamine and octamethylene diamine, phenylene diamine, 3,3′-dichloro-4,4′-diaminodiphenylmethane, and 4,4 ′. -Aromatic diamine compounds such as methylene bis (phenylamine), 4,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl sulfone, cyclopentanediamine, cyclohexyldiamine, 4,4-diaminodicyclohexylmethane, 1,4-diamino And alicyclic diamine compounds such as cyclohexane and isophorone diamine.

  Examples of the long-chain diamine include those obtained by polymerizing or copolymerizing alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.), and specific examples include polyoxyethylene diamine and polyoxypropylene diamine. Further, hydrazines such as hydrazine, carbohydrazide, adipic acid dihydrazide, sebacic acid dihydrazide and phthalic acid dihydrazide can be mentioned. These can be used alone or in combination of two or more.

  As the compound d, any of those conventionally used for producing polyurethane can be used and is not particularly limited. Preferred examples of the polyisocyanate compound include toluene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-isopropyl-1,3-phenylene diisocyanate, and 4-chloro-1,3-phenylene diisocyanate. 4-butoxy-1,3-phenylene diisocyanate, 2,4-diisocyanate diphenyl ether, 4,4′-methylenebis (phenylene isocyanate) (MDI), jurylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate (XDI), 1, Aromatic diisocyanates such as 5-naphthalene diisocyanate, benzidine diisocyanate, o-nitrobenzidine diisocyanate and 4,4′-diisocyanate dibenzyl, methyl Diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,10-decamethylene diisocyanate and other aliphatic diisocyanates, 1,4-cyclohexylene diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate) 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, alicyclic diisocyanates such as hydrogenated MDI and hydrogenated XDI, or these diisocyanate compounds and low molecular weight polyols or polyamines are reacted so that the terminal is isocyanate. Naturally, the obtained polyurethane prepolymer can also be used. Particularly preferred is an isocyanate compound produced by a non-phosgene method, and a raw material containing no chlorine compound is preferred.

  The production method of the resin of the present invention using the compounds a to d is not particularly limited, and a conventionally known polyurethane production method can be used. For example, in the presence or absence of an organic solvent containing no active hydrogen in the molecule, the compound a, the compound b, the compound c, and the compound d are combined with a chain extender, if necessary, A one-shot method in which the equivalent ratio of the isocyanate group of d and the active hydrogen of the compounds a to c (and the chain extender) is usually 1.0 or around (0.8 to 1.1) Or by a multistage process, usually at 20 to 150 ° C., preferably 60 to 110 ° C., until the product has no NCO.

  In the present invention, a catalyst can be used as necessary in the urethane synthesis. For example, salts of metals and organic and inorganic acids such as dibutyltin laurate, dioctyltin laurate, stannous octoate, lead octylate, tetra-n-butyl titanate, zirconium compounds, and organic compounds such as organometallic derivatives and triethylamine Examples thereof include amines and diazabicycloundecene catalysts.

  The resin of the present invention may be synthesized without a solvent, or may be synthesized using an organic solvent if necessary. Preferred solvents as organic solvents include those that are inert to isocyanate groups or less active than the reaction components. For example, ketone solvents (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), aromatic hydrocarbon solvents (toluene, xylene, swazol (aromatic hydrocarbon solvents manufactured by Cosmo Oil Co., Ltd.)), Solvesso (Exxon Chemical Co., Ltd.) Company-made aromatic hydrocarbon solvents), aliphatic hydrocarbon solvents (n-hexane, etc.), alcohol solvents (methyl alcohol, ethyl alcohol, isopropyl alcohol, etc.), ether solvents (dioxane, tetrahydrofuran, etc.) , Ester solvents (ethyl acetate, butyl acetate, isobutyl acetate, etc.), glycol ether ester solvents (ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate) Over DOO, such as ethyl 3-ethoxypropionate), amide solvents (dimethylformamide, dimethyl acetamide), lactam solvent (N- methyl-2-pyrrolidone, etc.). Of these, methyl ethyl ketone, ethyl acetate, acetone, tetrahydrofuran and the like are preferable in view of solvent recovery, solubility during urethane synthesis, reactivity, boiling point, and emulsifying dispersibility in water.

  The resin of the present invention may be synthesized without a solvent, or may be synthesized using a reactive diluent as a medium if necessary. Preferred reactive diluents include those that are inert to isocyanate groups or less active than the reaction components.

  The diluent used in the present invention can be crosslinked upon exposure. As a method of crosslinking, after blending and applying a reactive diluent and / or a photocurable crosslinking agent and a photopolymerization initiator (only in the case of an ultraviolet curing system) to the above polyurethane resin of the present invention, What is necessary is just to harden a film by irradiating an electron beam or an ultraviolet-ray.

  Examples of the reactive diluent and / or photocurable crosslinking agent used here include radical polymerization monofunctional acrylate compounds, polyfunctional acrylate compounds, and cationic polymerization compounds, but radical polymerization monofunctional acrylate compounds. As, for example, methoxytriethylene glycol acrylate, methoxy polyethylene glycol acrylate, vinyl caprolactam, ethyl carbitol acrylate, N-vinylformamide, N, N-dimethylaminoethyl acrylate, methoxytetraethylene glycol (meth) acrylate, methoxy polyethylene glycol (Meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methoxyethyl (meth) acrylate, N- Nyl-2-pyrrolidone, styrene, methyl methacrylate, phenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, methacrylic acid ester, N, N-dimethylacrylamide, N-isopropylacrylamide, acryloylmorpholine, glycerin monoallyl ether , 2-phenoxydiethyl acrylate, dicyclopentenyl acrylate, dicyclopentanyl acrylate, isobornyl acrylate, benzyl (meth) acrylate, epoxy acrylate (half ester obtained by reacting diol component and acid dianhydride) and derivatives thereof Etc. A commercially available hydrophobic radical polymerization type monofunctional acrylate compound can also be used.

  Examples of the polyfunctional acrylate compound include triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, diethylene glycol di (meth) acrylate, and polyethylene glycol di (meth) acrylate. Examples of the hydrophobic polyfunctional acrylate compound include trimethylolpropane tri (meth) acrylate, pentaerythritol hexa (meth) acrylate, trimethylolpropane di (meth) acrylate, and pentatrithritol tetra (meth) acrylate. Is mentioned. Examples of the cationic polymerization diluent include an epoxy compound, an oktacene compound, a vinyl ether compound, and the like. In addition, acrylic oligomers, polyester acrylate oligomers, epoxy acrylate oligomers, modified phenol epoxy acrylate oligomers, modified fluorene epoxy acrylate oligomers, urethane acrylate oligomers, and derivatives thereof can also be used.

  In the present invention, in the resin synthesis step, when an isocyanate group remains at the polymer terminal, an isocyanate terminal reaction terminator may be added. For example, not only monofunctional compounds such as monoalcohols and monoamines, but also compounds having two types of functional groups having different reactivities with respect to isocyanate groups can be used. Monoalcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol; monoethylamine, n-propylamine, diethylamine, di-n-propylamine, di- Examples include monoamines such as n-butylamine; alkanolamines such as monoethanolamine and diethanolamine. Among these, alkanolamines are preferable in that the reaction can be easily controlled.

  In the production of the resin of the present invention, additives may be added as necessary. For example, antioxidants (hindered phenols, phosphites, thioethers, etc.), light stabilizers (hindered amines, etc.), UV absorbers (benzophenones, benzotriazoles, etc.), gas discoloration stabilizers (hydrazines, etc.) ), Metal deactivators and the like, and two or more of these.

  In addition, a photocurable crosslinking agent obtained by reacting a polyfunctional polyisocyanate with an active hydrogen group-containing acrylate and / or an active hydrogen group-containing methacrylate compound, or one or more alkali-soluble groups (anionic groups) in one molecular chain A photocurable urethane-based cross-linking agent containing an unsaturated group can also be used. It is 120 mass parts or less with respect to 100 mass parts of resin of this invention, Preferably it can use within the range of 1-50 mass parts.

  Furthermore, a thermosetting cross-linking agent can be used in combination with a photo-curing cross-linking agent. For example, polyisocyanate crosslinking agents (including block type), melamine crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, epoxy crosslinking agents, inorganic crosslinking agents, cationic polymerization crosslinking agents (epoxy, oxetane, vinyl ether) System crosslinking agent). In particular, in the present invention, a crosslinking method utilizing the reactivity of an alkali-soluble group such as a urethane group and / or a carboxyl group is preferable, but is not particularly limited. The combined use of radical polymerization and cationic polymerization, radical polymerization and thermosetting crosslinking agent, etc. is effective for a system using a difference in crosslinking reaction (dual cure system) for various processes such as vacuum molding.

  Examples of the crosslinking method using a urethane group include crosslinking with a polyisocyanate crosslinking agent, but the polyisocyanate crosslinking agent is not particularly limited, and any conventionally known one can be used. Examples include polyfunctional aromatic isocyanates, polyfunctional aliphatic isocyanates, fatty acid-modified polyfunctional aliphatic isocyanates, blocked polyisocyanates such as blocked polyfunctional aliphatic isocyanates, and polyisocyanate prepolymers. These polyisocyanate crosslinking agents are effective in improving the adhesion between the coating and the plastic substrate if they are in an appropriate amount, but if the amount used is too large, unreacted isocyanate remains, which causes a problem. It is 120 mass parts or less with respect to 100 mass parts, Preferably it exists in the range of 1-50 mass parts.

  As a crosslinking method using an alkali-soluble group, for example, a carboxyl group, a carbodiimide crosslinking agent, an oxazoline crosslinking agent, an epoxy crosslinking agent, an oxetane crosslinking agent, a vinyl ether crosslinking agent, a metal complex crosslinking agent, or the like The publicly known thing used from can be used, and it does not specifically limit. For example, as an epoxy-type crosslinking agent, conventionally well-known commercially available epoxy resins, such as "Epicoat" (made by Yuka Shell Epoxy), are mentioned. As the carbodiimide-based crosslinking agent, a commercially available product having a trade name of “Carbodilite” (manufactured by Nisshinbo Co., Ltd.) can be obtained and used.

  The crosslinking agent reacts with a carbodiimide group and a carboxyl group to form an N-acyl urea to improve the coating performance. As the oxazoline-based crosslinking agent, commercially available products such as “Epocross” trade name (manufactured by Nippon Shokubai Co., Ltd.), WS-300, WS-500, W-700, and WS-R10 can be obtained and used. These crosslinking agents take a crosslinked structure by reacting the oxazoline group of the crosslinking agent and the carboxyl group of the resin to form an amide ester. Moreover, as an oxetane type crosslinking agent, the commercial item of the brand name (made by Ube Industries) of "Ethanacol" can be obtained and used. Commercially available products such as BASF, IPS Japan, Maruzen Petrochemical, Nippon Shokubai Co., Ltd. can be used as the vinyl ether crosslinking agent.

  The crosslinking agent reacts by cationic polymerization or forms an alkoxyester by Michael addition reaction. These crosslinking agents are 0.1-50 mass parts or less with respect to 100 mass parts of resin of this invention, Preferably it exists in the range of 1-40 mass parts. If the use amount of the crosslinking agent is lower than the above range, the effect of the crosslinking agent cannot be obtained. On the other hand, if the use amount of the crosslinking agent is higher than the above range, blocking occurs, moldability is reduced, and cost is increased. .

  As the metal complex-based crosslinking agent, titanium organic compound-based, zirconium organic compound-based commercially available under the trade name of “Orgatyx” (manufactured by Matsumoto Pharmaceutical Co., Ltd.) are available, and aluminum, chromium, cobalt, copper, Iron, nickel, vanadium, zinc, indium, calcium, magnesium, manganese, yttrium, cerium, strontium, palladium, barium, molybdenium, lanthanum, tin sold under the trade name "Narsem" (manufactured by Nippon Kagaku Sangyo Co., Ltd.) An acetylacetone complex can be obtained and used.

  Further, in the case of silanol-based crosslinking agent (silyl type crosslinking agent), the film performance is improved by self-condensation. As this silane coupling crosslinking agent, it is marketed by the brand name (made by Shin-Etsu Chemical Co., Ltd.) of "KBM-, KBE-series". These crosslinking agents are particularly effective for improving the durability if they are in an appropriate amount. However, if the amount used is too large, it will significantly shorten the working life and cause the coating to become brittle. 40 parts by mass or less, preferably 0.5 to 20 parts by mass.

  In the present invention, a photopolymerization initiator is used only in the case of an ultraviolet curing system. As the photopolymerization initiator, one that generates a radical by light and reacts with the polymerizable unsaturated compound is desirable. Although not particularly limited, for example, benzophenone, acetophenone, benzoin, benzoin isobutyl ether, benzoin isopropyl ether, benzoin ethyl ether, 2,4-dimethylthioxanthone, 2-chlorothioxanthone, ethyl anthraquinone, 4,4′-bisdimethyl Examples include aminobenzophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and benzylmethylketanol. Examples of the cationic polymerization initiator include diazonium salt type compounds, sulfonium salt type compounds, iodonium salt type compounds, and the like. These compounds may be used in combination.

  Various additives can be added to the ink binder of the present invention as required. For example, organic fine particles, inorganic fine particles, flame retardants, pigments, and other additives can be appropriately used as a relaxation agent during curing shrinkage. Examples of the organic fine particles and inorganic fine particles may include silica, silicone resin fine particles, fluororesin fine particles, acrylic resin fine particles, urethane resin fine particles, silicone-modified urethane resin fine particles, polyethylene fine particles, and the like.

  In addition, the solder resist ink using the binder for ink of the present invention is directly coated on the entire surface of the substrate (copper-formed printed circuit board) with a screen printing machine and precure (80 to 100 ° C., 20 to 30 minutes). The film is exposed through a negative film, the uncured portion is washed with an alkaline developer, and post-cured (around 150 ° C. for 60 minutes) to form a substrate.

  The solid content thickness when the solder resist ink using the binder for ink of the present invention is applied by a screen printer is 5 to 100 μm, preferably about 5 to 40 μm.

  The above-described ink containing the binder for ink of the present invention undergoes a curing reaction by electron beam irradiation or ultraviolet irradiation to achieve high resolution, alkali cleaning properties, heat resistance, water resistance, adhesion to substrates, chemical resistance, and electrical insulation. In addition, a printed circuit board having a coating with improved non-chlorine material, low curing shrinkage, flexibility, high elongation, and workability is provided.

  Hereinafter, the present invention will be described more specifically with reference to production examples, examples and comparative examples, but the present invention is not limited thereto. Moreover, in the following sentence, “part” indicates mass part, and “%” indicates mass%.

The synthesis examples 1-5 of the urethane type resin used for this invention are shown.
After replacing the reaction vessel equipped with a stirrer, reflux condenser, thermometer, nitrogen blowing tube and manhole with nitrogen gas, an alkali-soluble group (anionic group) -containing compound (compound a), an unsaturated group-containing compound (compound A predetermined amount of b), carbonate diol (compound c), and cyclohexanone was added and dissolved uniformly to adjust the solution concentration. Subsequently, a polyisocyanate compound (compound d) was added at an equivalent ratio of a predetermined amount (NCO / OH = 1.0) and reacted at 80 ° C. until the NCO group disappeared. Table 1 shows the raw material composition of the polyurethane resin.

note)
Compound a:
A-1: dimethylolbutanoic acid a-2: dimethylolpropanoic acid

・ＰＣＤ（２）：ＰＣＤＬ Ｔ４６７２、ポリカーボネートジオール（旭化成ケミカルズ社製、平均分子量２，０００）
・ＰＣＤ（３）：ＰＣＤＬ Ｔ５６５２、ポリカーボネートジオール（旭化成ケミカルズ社製、平均分子量２，０００） Compound b:
・ GMAE: Glycerol monoallyl ether (Daiso)
・ GMA: Glycerin monomethacrylate (manufactured by NOF Corporation)
Compound c:
PCD (1): Plaxel CD220, polycarbonate diol (manufactured by Daicel Chemical Industries, average molecular weight 2,000)

PCD (2): PCDL T4672, polycarbonate diol (Asahi Kasei Chemicals, average molecular weight 2,000)
PCD (3): PCDL T5652, polycarbonate diol (Asahi Kasei Chemicals, average molecular weight 2,000)

Compound d:
· HDI: hexamethylene diisocyanate · H ₁₂ MDI: hydrogenated MDI (non-phosgene process)
IPDI: Isophorone diisocyanate (non-phosgene production method)

  Using the polyurethane-based resin obtained in the above synthesis example, the solder resist ink of the present invention was prepared as follows (Table 2).

(note)
・ Polymerization initiator; Irgacure 184 (Ciba Specialty Chemicals)

Oligomer 1: Epoxy acrylate, bifunctional, Tg = 75
Oligomer 2: Modified bisphenol A / epoxy acrylate, bifunctional, Tg = 60

On the ink substrate (copper-formed printed circuit board), the solder resist prepared in Examples 1 to 4 and Comparative Example 1 was used.
1. After coating directly on the whole surface with a screen printer (solid thickness 40μm),
2. Precure (80 ° C., 20 minutes), exposed through a negative film (200 mJ / cm ² ),
3. The uncured portion is washed with an alkali developer (Na ₂ CO ₃ , 1% by mass aqueous solution, 30 ° C., 60 seconds)
4). Post cure (around 150 ° C., 60 minutes) to form a solder resist.

The solder resist substrates produced in Examples 1 to 4 and Comparative Example 1 were evaluated on the following items.
<Developability>
The detergency of the uncured part was confirmed with the alkali developer (Na ₂ CO ₃ , 1% by mass aqueous solution, spray pressure 0.2 MPa, 30 ° C., 60 seconds) in the above-described No. 3 step.
○: Passed under the above conditions.
X: 60 seconds or more are required.

<Solder heat resistance>
After immersion in flow solder (10 seconds in a 260 ° C. solder bath) on the test substrate, an adhesion test using a cellophane adhesive tape was performed to confirm the state of the cured coating.
○: No change in the cured coating.
X: The cured film peeled off.

<Curing shrinkage>
The polyimide film (thickness 25 μm) was coated with the solder resist ink prepared in Examples 1 to 4 and Comparative Example 1 (solid content thickness: 25 μm) and exposed (200 mJ / cm ² ). A 7 cm test piece was prepared, and the warpage after standing at room temperature for 24 hours was confirmed.
○: No warpage is observed in the specimen.
X: Warpage is observed in the test piece.

<Bendability>
The test piece prepared in the above test was folded 180 ° so that the cured coating was on the outside, and the bent portion was observed with a microscope.
○: The cured film has no cracks.
X: A crack occurs in the cured coating.

<Heat shock resistance>
The appearance change was observed when the test piece prepared in the above test was subjected to 100 cycles at −65 ° C./30 minutes to 125 ° C./30 minutes as one cycle.
○: No change in appearance.
X: The appearance is abnormal.

<Hydrochloric acid resistance>
The appearance change after immersing the test piece produced in the above test in a hydrochloric acid solution at 25 ° C. for 5 minutes was observed.
○: No change in appearance.
X: The appearance is abnormal.

  The ink binder of the present invention has a high resolution, alkali washability, heat resistance, water resistance, adhesion to a substrate, chemical resistance, and a curing reaction of an ink containing the same by electron beam irradiation or ultraviolet irradiation. It is an ink binder that has improved electrical insulation and is excellent in non-chlorine materials, low curing shrinkage, flexibility, high elongation, and processability. Of course, it is also one of the features that the binder for ink is tack-free before electron beam irradiation or ultraviolet irradiation (before curing reaction).

Claims (6)

  A compound (a) having both at least one active hydrogen-containing group and at least one alkali-soluble group (anionic group) in the molecule; and at least one active hydrogen-containing group and a vinyl group (invalid in the molecule). A compound (b) having both a saturated bond group), a polycarbonate-based polyol (c), and a polyisocyanate (d), the total active hydrogen of the total of the compounds (a) to (c) and the compound (d) A urethane-based resin having at least an alkali-soluble group and a vinyl group in the same molecule, which is obtained by reacting an isocyanate group with NCO / OH = 0.8 to 1.1 mol, is contained as a film-forming component. Electron beam curable or ultraviolet curable ink binder.   2. The electron beam curable or ultraviolet curable ink binder according to claim 1, wherein the compound (a) is dimethylolbutanoic acid and / or dimethylolpropanoic acid. The electron beam curable or ultraviolet curable ink binder according to claim 1, wherein the compound (c) is a compound represented by the following formula.

  The compound (a) is used in an amount of 0.01 to 30% by mass, the compound (b) is used in an amount of 0.01 to 30% by mass, the compound (c) is used in an amount of 10 to 80% by mass, The amount of the compound (d) used is such that the equivalent ratio of the total active hydrogen of the total of the compounds (a) to (c) and the isocyanate group of the compound (d) is 0.8 to 1.1, 2. The electron beam curable ink or ultraviolet curable ink binder according to claim 1, which has an average molecular weight of 2,000 to 500,000.   The binder for electron beam curable or ultraviolet curable ink according to claim 1, further comprising an electron beam curable, ultraviolet curable or thermosetting monofunctional monomer, polyfunctional monomer or oligomer.   Hardened | cured material of the binder for electron beam curable type or ultraviolet curable inks of Claim 1.