JP5996987B2 - UV curable transparent resin composition - Google Patents

Description

  The present invention relates to an ultraviolet curable transparent resin composition suitable for forming an insulating film on a substrate, for example, a polycarbonate film having a patterned ITO (indium tin oxide) layer as a base material, or a circuit on a polycarbonate film. The present invention relates to an ultraviolet curable transparent resin composition capable of forming an insulating film having excellent smoothness while having excellent smoothness on the polycarbonate surface when a flexible wiring board on which a pattern is formed is used.

  For example, in order to form a transparent insulating film on a substrate such as a polyethylene terephthalate film (PET film), a polyimide film, a polyester film, or a film (ITO film) obtained by forming an ITO layer on a PET film, an ultraviolet curable transparent A resin composition may be applied on the substrate.

  Therefore, as an ultraviolet curable resin composition excellent in adhesion and insulation to an ITO film, monofunctional active light having an aromatic group in the molecule with respect to 100 parts by weight of the active light polymerizable polymer containing polyester as a copolymerization component. There are those containing 20 to 360 parts by mass of a polymerizable compound, 20 to 200 parts by mass of a bifunctional active light polymerizable compound having a bisphenol structure in the molecule, and 20 to 400 parts by mass of an inorganic filler (Patent Document 1).

  On the other hand, in recent years, it is strongly desired not to lower the visibility of an electrode substrate for a touch panel incorporated in the front surface of a display body such as a liquid crystal display. Then, use of the ITO film which used the polycarbonate film instead of each said resin film is examined from the point which is excellent in transparency rather than each said resin film.

  However, since the polycarbonate film is inferior in wettability with the ultraviolet curable transparent resin composition, that is, the wettability of the interface with the polycarbonate film, compared with the PET film or the like, the UV cure applied on the polycarbonate film. The transparent transparent resin composition tends to be repelled. As a result, there was a problem that a coating film having excellent smoothness and transparency could not be formed on the polycarbonate film.

  Further, the solder resist film formed on the printed wiring board is also required to have better smoothness and transparency.

JP 2009-84350 A

  In view of the above circumstances, the present invention provides an ultraviolet curable transparent resin composition capable of forming a coating film having excellent smoothness and good transparency on the surface of a polycarbonate substrate without impairing insulation. Objective.

An aspect of the present invention is an ultraviolet curable transparent resin composition containing ( A) a ( meth) acrylic resin and (B) a photopolymerization initiator, the (A) (meth) acrylic resin Is a polycarbonate base material that is not surface-treated, containing (meth) acrylic resin that is a polymer of cyclohexyl (meth) acrylate, and containing 50% by mass or more of (A) (meth) acrylic resin It is an ultraviolet curable transparent resin composition for film-forming with respect to a printed wiring board or a flexible wiring board .

  The contact angle with polycarbonate is an angle between the tangent to the surface of the liquid droplet and the polycarbonate surface for the liquid (meth) acrylic resin component droplet formed on the flat polycarbonate film surface. Here, the contact angle is obtained by dropping a (meth) acrylic resin component (which is liquid at room temperature (for example, 25 ° C.)) before curing onto a flat polycarbonate film surface at room temperature. When droplets of (meth) acrylic resin component are formed on the polycarbonate film surface, the maximum height of the droplets is h, and the average radius of the droplets at the interface (contact portion) with the polycarbonate surface is d Furthermore, it means a double value of θ calculated by h / d− = tan θ, that is, a value of 2 × θ. In addition, said h and d are measured using the contact angle meter based on JISR3257. When the (A) (meth) acrylic resin is a mixture of two or more types of the (A) (meth) acrylic resin, the contact angle of the mixture is 12 ° or less. means. In this embodiment, the (A) (meth) acrylic resin is blended in an amount of 50% by mass or more in the ultraviolet curable transparent resin composition.

  An aspect of the present invention is an ultraviolet curable transparent resin composition having a contact angle of 10 ° or less. In this embodiment, (A) 50% by mass or more of (meth) acrylic resin having a contact angle with polycarbonate of 10 ° or less is contained.

An embodiment of the present invention is an ultraviolet curable transparent resin composition in which the (A) (meth) acrylic resin is a polymer of cyclohexyl (meth) acrylate .

  An aspect of the present invention is an ultraviolet curable transparent resin composition for forming a coating film on a polycarbonate substrate that has not been surface-treated. In this embodiment, the ultraviolet curable transparent resin composition is applied to the surface of a polycarbonate substrate that has not been surface-treated.

  An aspect of the present invention is an ultraviolet curable transparent resin composition in which the (B) photopolymerization initiator includes an α-hydroxyketone photopolymerization initiator.

  An embodiment of the present invention is an ultraviolet curable transparent resin composition in which the (B) photopolymerization initiator includes an α-hydroxyketone photopolymerization initiator and an acylphosphine photopolymerization initiator.

  The aspect of this invention is a printed wiring board which has the cured coating film obtained by apply | coating the said ultraviolet curable transparent resin composition.

  According to the aspect of the present invention, (A) by containing 50% by mass or more of a (meth) acrylic resin having a contact angle with a polycarbonate of 12 ° or less, the polycarbonate substrate such as a polycarbonate film has smoothness. A cured coating film having excellent and good transparency can be formed.

  According to the aspect of the present invention, (A) a cured coating excellent in smoothness can be applied to a polycarbonate substrate by containing 50% by mass or more of (meth) acrylic resin having a contact angle with polycarbonate of 10 ° or less. A film can be formed.

  According to the aspect of the present invention, since the (A) (meth) acrylic resin has an alicyclic skeleton, the contact angle with the polycarbonate can be further reduced, and a cured coating film excellent in smoothness can be formed.

  According to the aspect of the present invention, (B) the photopolymerization initiator includes the α-hydroxyketone photopolymerization initiator, thereby reliably preventing the cured coating from being discolored and the transmittance and haze from being deteriorated. it can.

  According to the aspect of the present invention, the (B) photopolymerization initiator contains an α-hydroxyketone photopolymerization initiator and an acylphosphine photopolymerization initiator, thereby preventing discoloration of the cured coating film and preventing ultraviolet rays. The photocurability can be improved.

  Next, the ultraviolet curable transparent resin composition of the present invention will be described. The ultraviolet curable transparent resin composition of the present invention comprises (A) a (meth) acrylic resin having a contact angle of 12 ° or less with polycarbonate, and (B) a photopolymerization initiator. It is a resin composition, Comprising: The said (A) (meth) acrylic-type resin contains 50 mass% or more.

(A) (meth) acrylic resin having a contact angle with polycarbonate of 12 ° or less (A) Component (meth) acrylic resin is an ultraviolet curable transparent resin composition with respect to polycarbonate resin having an untreated surface. Blended to improve the wettability of the product and form a smooth cured coating.

  The (A) component (meth) acrylic resin is not particularly limited as long as the contact angle with the (A) polycarbonate is 12 ° or less. For example, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Ethoxyethoxyethyl (meth) acrylate, lauryl (meth) acrylate, phenol (meth) acrylate, 1,4-butanediol di (meth) acrylate, 2-hydroxypropyl (meth) acrylate, neopentyl glycol diacrylate, etc. ) A resin obtained by polymerizing an acrylic monomer, or a resin obtained by polymerizing a monomer having the (meth) acrylic monomer as a main component. In addition, each said resin is a range whose contact angle with a polycarbonate is 7 degrees-12 degrees.

  The (meth) acrylic resin as the component (A) may be used alone, or the contact angle with the polycarbonate as a whole of the (meth) acrylic resin as the component (A) may be 12 ° or less. You may mix and use 2 types or more of (A) component (meth) acrylic-type resin.

  Among these, (A) the contact angle with the polycarbonate is 10 ° or less, and from the point that a cured coating film excellent in smoothness can be formed, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethoxyethoxyethyl ( Resins obtained by polymerizing (meth) acrylic monomers such as (meth) acrylate, lauryl (meth) acrylate, phenol (meth) acrylate, 1,4-butanediol di (meth) acrylate, and 2-hydroxypropyl (meth) acrylate are preferable. .

  (A) Component (meth) acrylic resin is commercially available, for example, “Light Ester 1,4BG” manufactured by Kyoeisha Chemical Co., Ltd. (contact angle with polycarbonate of 10 °, monomer type: 1,4- Butanediol dimethacrylate), “light ester HOP” (contact angle with polycarbonate 10 °, monomer type: 2-hydroxypropyl methacrylate), “Viscoat # 155” manufactured by Osaka Organic Chemical Co., Ltd. (contact angle 7 ° with polycarbonate, Monomer species: cyclohexyl acrylate), “Miramer M140” from Miwon (contact angle with polycarbonate 9 °, monomer species: phenol acrylate), “Miramer M170” from Miwon (contact angle 8 ° with polycarbonate), Monomer species: ethoxyethoxyethyl acrylate), "Light acrylate NP-A" (manufactured by Kyoeisha Chemical Co., Ltd.) Contact angle 11 °, monomer type: neopentyl glycol diacrylate) and the like.

  The blending ratio of the (meth) acrylic resin as the component (A) is 50% by mass or more in the ultraviolet curable transparent resin composition from the viewpoint of imparting smoothness to the cured coating film, and further improves the smoothness. 70 mass% or more is preferable from a point, and 75 mass% or more is especially preferable.

(B) Photopolymerization initiator The photopolymerization initiator is not particularly limited as long as it is generally used. For example, an oxime ester photopolymerization initiator, an α-hydroxyketone photopolymerization initiator, and an acylphosphine. Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2 , 2-Diethoxy-2-phenylacetophenone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiary Butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4 diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, P-dimethylaminobenzoic acid An ethyl ester etc. are mentioned. These may be used alone or in combination of two or more.

  Among these, by using an α-hydroxyketone photopolymerization initiator, a cured product having excellent discoloration resistance and high transmittance can be formed. Examples of the α-hydroxyketone photopolymerization initiator include 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and 1- [4- (2- Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl]- And phenyl} -2-methyl-propan-1-one.

  Further, by using an acylphosphine photopolymerization initiator, the sensitivity to ultraviolet rays can be increased and the photocurability can be improved. The acylphosphine photopolymerization initiator is not particularly limited as long as it is a photopolymerization initiator having an acylphosphine structure. For example, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6) -Acylphosphine oxide such as -trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethylbenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine oxide A compound can be mentioned.

  When ultraviolet light having a wavelength of 300 to 400 nm is irradiated to the ultraviolet curable transparent resin composition of the present invention, the photopolymerization initiator promotes photocuring of the ultraviolet curable transparent resin composition. The blending ratio of the photopolymerization initiator can be appropriately selected as long as the (meth) acrylic resin (A) is contained in an amount of 50% by mass or more. For example, 1 to 50 mass in the ultraviolet curable transparent resin composition. % Is preferable, 2 to 30% by mass is more preferable, and 5 to 25% by mass is particularly preferable.

  The ultraviolet curable transparent resin composition of the present invention is a (meth) acrylated epoxy resin having a contact angle with a polycarbonate of more than 12 °, if necessary, in addition to the components (A) and (B). (D) A (meth) acrylated urethane resin having a contact angle with polycarbonate of more than 12 ° and (E) a flame retardant may be blended.

(C) (meth) acrylated epoxy resin having a contact angle with polycarbonate exceeding 12 ° (C) Component (meth) acrylated epoxy resin is an epoxy resin having two or more epoxy groups in one molecule. On the other hand, it is an epoxy (meth) acrylate obtained by esterifying (meth) acrylic acid. The (meth) acrylated epoxy resin has a (meth) acryl group that can be radically polymerized by ultraviolet irradiation. Therefore, when the (meth) acrylated epoxy resin is blended with the ultraviolet curable transparent resin composition of the present invention, (meth) acrylated epoxy resins undergo a crosslinking reaction by ultraviolet irradiation, and the crosslinking density of the cured product increases. Curability is further improved, and mechanical strength can be imparted to the cured product.

  The structure of the (meth) acrylated epoxy resin is not particularly limited, but is 50 to 100% equivalent to the epoxy group of the epoxy resin with respect to the epoxy resin having at least two epoxy groups in one molecule. A (meth) acrylated epoxy resin obtained by esterifying (meth) acrylic acid is preferred, and it is obtained by esterifying 80 to 100% equivalent of (meth) acrylic acid from the viewpoint of photocurability ( A (meth) acrylated epoxy resin is particularly preferred.

  The kind of epoxy resin that is a raw material for synthesizing (meth) acrylated epoxy resin is not particularly limited. For example, bisphenol A type epoxy resin (bisphenol A type liquid epoxy resin, bisphenol A type modified flexible epoxy resin, nuclear hydrogenated bisphenol) A type liquid epoxy resin), novolak type epoxy resin (phenol novolak type epoxy resin, o-cresol novolak type epoxy resin, p-tert-butylphenol novolak type, etc.), bisphenol F and bisphenol S are obtained by reacting with epichlorohydrin. Bisphenol F type and bisphenol S type epoxy resins, cycloaliphatic epoxy resins having cyclohexene oxide groups, tricyclodecane oxide groups, cyclopentene oxide groups, tris (2,3-epoxys) Propyl) isocyanurate, triglycidyl tris (2-hydroxyethyl) triglycidyl isocyanurate having a triazine ring such as isocyanurate, dicyclopentadiene type epoxy resins, adamantane type epoxy resins and the like. These compounds may be used alone or in combination of two or more.

  The (meth) acrylated epoxy resin usually has a contact angle with the polycarbonate of more than 12 °, and the wettability with respect to the polycarbonate is lower than the (meth) acrylic resin of the component (A). All of the above exemplified (meth) acrylated epoxy resins have a contact angle with polycarbonate of more than 12 °.

  The blending ratio of the (meth) acrylated epoxy resin can be appropriately selected as long as the (meth) acrylic resin (A) is contained in an amount of 50% by mass or more. For example, the lower limit value thereof is photocuring and curing. 1 mass% is preferable in an ultraviolet curable transparent resin composition from the point which provides mechanical strength to a thing, and 5 mass% is especially preferable from the point of stress relaxation. On the other hand, the upper limit is preferably 20% by mass in the ultraviolet curable transparent resin composition from the viewpoint of surely maintaining good smoothness of the cured coating film, and the balance between mechanical strength and excellent smoothness. From the point, 10% by mass is particularly preferable.

(D) (Meth) acrylated urethane resin whose contact angle with polycarbonate is more than 12 ° (D) Component (meth) acrylated urethane resin is obtained by esterifying (meth) acrylic acid to urethane resin. It is urethane (meth) acrylate obtained. When the (meth) acrylated urethane resin is contained in the ultraviolet curable transparent resin composition, a cured coating film excellent in flexibility can be formed.

  The urethane resin is obtained by reacting a compound having two or more isocyanate groups in one molecule with a polyol compound having two or more hydroxyl groups in one molecule.

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

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

  The (meth) acrylated urethane resin usually has a contact angle with the polycarbonate of more than 12 °, and the wettability with respect to the polycarbonate is lower than the (meth) acrylic resin of the component (A). All of the above exemplified (meth) acrylated urethane resins have a contact angle with polycarbonate of more than 12 °.

  The blending ratio of the (meth) acrylated urethane resin can be appropriately selected as long as the (meth) acrylic resin of the component (A) is contained in an amount of 50% by mass or more. For example, the lower limit value is flexible to the cured coating film. 1 mass% is preferable in the ultraviolet curable transparent resin composition from the point which provides property, and 5 mass% is especially preferable from an insulating point. On the other hand, the upper limit value is preferably 20% by mass in the ultraviolet curable transparent resin composition from the viewpoint of reliably maintaining good smoothness of the cured coating film, and has a good balance between smoothness and flexibility. To 10% by mass is particularly preferable.

(E) Flame retardant A flame retardant can be provided to a cured coating film by mix | blending a flame retardant with the ultraviolet curable transparent resin composition of this invention. A flame retardant is not specifically limited, A well-known thing can be used, For example, a phosphorus element containing compound can be mentioned. Specific examples of the phosphorus element-containing compound include tris (chloroethyl) phosphate, tris (2,3-dichloropropyl) phosphate, tris (2-chloropropyl) phosphate, tris (2,3-bromopropyl) phosphate, tris (bromo). Halogenated phosphoric acid such as chloropropyl) phosphate, 2,3-dibromopropyl-2,3-chloropropyl phosphate, tris (tribromophenyl) phosphate, tris (dibromophenyl) phosphate, tris (tribromoneopentyl) phosphate Non-halogen aliphatic phosphates such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triallyl phosphine; Riphenyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, tricresyl phosphate, trixylenyl phosphate, xylenyl diphenyl phosphate, tris (isopropylphenyl) phosphate, isopropylphenyl diphenyl phosphate, diisopropylphenylphenyl phosphate, tris (trimethyl Phenyl) phosphate, tris (t-butylphenyl) phosphate, hydroxyphenyl diphenyl phosphate, octyl diphenyl phosphate, 3-glycidyloxypropylene diphenylphosphine oxide, 3-glycidyloxydiphenylphosphine oxide, diphenylvinylphosphine oxide, 2- (9,10 -Dihydro-9-oxa-10-oxai -10-phosphaphenanthrene-10-yl) methylsuccinic acid bis- (2-hydroxyethyl) -ester non-halogen aromatic phosphate such as polymer; aluminum trisdiethylphosphinate, aluminum diethylphosphinate, trismethylethylphosphine Aluminum phosphate, aluminum trisdiphenylphosphinate, zinc bisdiethylphosphinate, zinc bismethylethylphosphinate, zinc bisdiphenylphosphinate, titanyl bisdiethylphosphinate, titanium tetrakisdiethylphosphinate, titanyl bismethylethylphosphinate, tetrakismethylethyl Metal salts of phosphinic acid such as titanium phosphinate, titanyl bisdiphenylphosphinate, titanium tetrakisdiphenylphosphinate, etc. The These may be used alone or in combination of two or more.

  The blending ratio of the flame retardant can be appropriately selected as long as the (A) component (meth) acrylic resin is contained in an amount of 50% by mass or more. For example, the upper limit value ensures a decrease in flexibility of the cured coating film. 20 mass% is preferable in the ultraviolet curable transparent resin composition, and 15 mass% is especially preferable from the point which suppresses the reduction | decrease in the mechanical strength of a cured coating film.

  The ultraviolet curable transparent resin composition of the present invention may further contain various additive components, for example, various additives, solvents, and the like as necessary in addition to the above-described components.

  Various additives include antifoaming agents such as vinyl polymers and acrylic polymers.

  The solvent is used to adjust the viscosity and drying property of the ultraviolet curable transparent resin composition. Examples of the solvent include ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, isopropanol and cyclohexanol, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, Petroleum solvents such as petroleum ether and petroleum naphtha, cellosolves such as cellosolve and butylcellosolve, carbitols such as carbitol and butylcarbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, diethylene glycol mono Examples thereof include acetates such as ethyl ether acetate and butyl carbitol acetate.

  The mixing ratio of the solvent can be appropriately selected as long as the (A) component (meth) acrylic resin is contained in an amount of 50% by mass or more, and for example, 1 to 10% by mass is preferable in the ultraviolet curable transparent resin composition. .

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

  Next, a method for using the above-described ultraviolet curable transparent resin composition of the present invention will be described. Here, a method of forming a transparent insulating film by applying the ultraviolet curable transparent resin composition of the present invention on an ITO film in which an ITO layer is formed on a polycarbonate film will be described as an example.

  On the ITO film, the ultraviolet curable transparent resin composition produced as described above is applied to a desired thickness using methods such as screen printing, spray coating, bar coater, spin coater, and ink jet printing.

  Thereafter, the target transparent insulating film can be formed on the ITO film by irradiating the applied ultraviolet curable transparent resin composition with ultraviolet rays.

  In place of the ITO film, the ultraviolet curable transparent resin composition of the present invention is applied to a printed wiring board manufactured with a flexible wiring board or a glass epoxy substrate, and the solder is applied to the flexible wiring board or the printed wiring board. A resist film may be formed.

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

Examples 1 to 23, Comparative Examples 1 to 4
Each component shown in the following Table 1 is blended at a blending ratio shown in the following Table 1, mixed and dispersed at room temperature using a bead mill, and used in Examples 1-23 and Comparative Examples 1-4. A transparent resin composition was prepared. And the prepared ultraviolet curable transparent resin composition was applied as follows, and the test piece was created. In addition, the numerical value of the mixture ratio in Table 1 shows mass.

The details of each component in Table 1 are as follows.
(A) (meth) acrylic resin / biscoat # 155 having a contact angle with polycarbonate of 12 ° or less: cyclohexyl acrylate, manufactured by Osaka Organic Chemical Co., Ltd.
Miramer M140: Made from Miwon, phenol acrylate.
Light ester 1,4BG: 1,4-butanediol dimethacrylate manufactured by Kyoeisha Chemical Co., Ltd.
Light acrylate NP-A: manufactured by Kyoeisha Chemical Co., Ltd., neopentyl glycol diacrylate.
(B) Photopolymerization initiator, Irgacure 184: 1-hydroxy-cyclohexyl-phenyl-ketone manufactured by BASF.
Irgacure 1173: 2-hydroxy-2-methyl-1-phenyl-propan-1-one from BASF.
・ Irgacure 754: BASF, 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester, a mixture of oxyphenylacetic acid and 2- (2-hydroxyethoxy) ethyl ester ・ LUCIRIN TPO: BASF, 2 , 4,6-Trimethylbenzoyl-diphenyl-phosphine oxide.
SPEEDCURE 819: manufactured by BASF, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide.

(C) (meth) acrylated epoxy resin having a contact angle with polycarbonate of more than 12 ° -EBECRYL 3708: manufactured by Daicel-Cytec Co., Ltd., mixture of epoxy acrylate and 2-hydroxyethyl acrylate, contact with polycarbonate Angle 55 °.
Miramer PE110: MIWON, contact angle with phenyl epoxy acrylate, polycarbonate of 32 °.
-Miramer PE250: manufactured by MIWON, bisphenol A type epoxy dimethacrylate, contact angle 48 ° with polycarbonate.
(D) Contact angle with polycarbonate is more than 12 ° (meth) acrylated urethane resin EBECRYL 8405: manufactured by Daicel-Cytec Co., Ltd., contact angle with urethane acrylate, polycarbonate is 78 °.
Aronix M-1200: manufactured by Toagosei Co., Ltd., contact angle of 60 ° with urethane acrylate and polycarbonate.
AH-600: Kyoeisha Chemical Co., Ltd., phenyl glycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer, contact angle of 65 ° with polycarbonate.
(E) Flame retardant, diphenyl vinyl phosphine oxide: manufactured by Katayama Chemical Co., Ltd.
ME-P8: Sanko Co., Ltd., 2- (9,10-Dihydro-9-oxa-10-oxide-10-phosphaphenanthrene-10-yl) methylsuccinic acid bis- (2-hydroxyethyl) -ester Polymer.
・ Triallylphosphine: manufactured by Toyo Science Co., Ltd.

Additive, Disparon UVX-189: Enomoto Chemical Co., Ltd., vinyl polymer.
・ Polyflow No. 90: Acrylic polymer manufactured by Kyoeisha Chemical Co., Ltd.
Solvent / diethylene glycol monoethyl ether acetate: manufactured by Shinko Organic Chemical Industry Co., Ltd.

(Meth) acrylic resin / light ester 1,9ND having a contact angle with polycarbonate of more than 12 °: 1,9-nonanediol dimethacrylate manufactured by Kyoeisha Chemical Co., Ltd.
・ Aronix M-350: Trimethylolpropane EO-modified triacrylate, manufactured by Toagosei Co., Ltd.

Test piece preparation process UV curable transparent resin composition prepared as described above by screen printing on the surface of polycarbonate film “Panlite 2151” (manufactured by Teijin Chemicals Ltd., film thickness 125 μm) which has not been surface-treated. The object was applied. Then, ultraviolet rays (300 to 400 nm) were exposed to 1000 mJ / cm ² with an exposure apparatus (UB093-5AM, manufactured by Eye Graphic Co., Ltd.) to form a cured coating film on the polycarbonate film. The thickness of the cured coating film was 8 to 10 μm.

Evaluation (1) Contact angle of (meth) acrylic resin with polycarbonate The contact angle with the polycarbonate film was measured according to JIS R 3257 using a solid surface energy analyzer CA-150W (manufactured by Kyowa Interface Science Co., Ltd.).
(2) Transmittance The substrate was changed from a polycarbonate film to quartz glass (50 mm × 50 mm × thickness 1 mm), coating was performed according to the above test piece preparation process, and JIS-K-7105 was applied to the resulting cured coating film. According to JIS-K-7136, the total light transmittance was measured using a U-3310 spectrophotometer manufactured by Hitachi High-Tech.
(3) Haze (cloudiness value) (%)
The substrate was changed from a polycarbonate film to quartz glass (50 mm × 50 mm × thickness 1 mm) and coated according to the above-mentioned test piece preparation process, and JIS-K-7105 and JIS-K— were applied to the obtained cured coating film. In accordance with 7136, haze was measured using a U-3310 spectrophotometer manufactured by Hitachi High-Tech.

(4) Surface smoothness on polycarbonate film About the test piece produced in the said test piece preparation process, the external appearance of the cured coating film surface was observed visually, and it evaluated in four steps as follows.
A: A uniform and extremely smooth surface over the entire surface of the coating film. ○: A uniform and smooth surface over the entire surface of the coating film. Δ: Smooth overall, but with some distorted skin. X: There is an overall yuzu skin.
(5) Insulation (Ω)
Instead of the polycarbonate film, a test film was formed by applying a comb-shaped test pattern (line width: 100 μm, line spacing: 100 μm) in the same manner as in the test piece preparation step to form a cured coating film. The test piece was applied with a direct current of 50 V in an atmosphere having a temperature of 85 ° C. and a humidity of 85% and left for 1000 hours.

  The evaluation results are shown in Table 2.

  As shown in the results of Examples in Table 2, when a (meth) acrylic resin having a contact angle with a polycarbonate of 12 ° or less is used in an ultraviolet curable transparent resin composition in an amount of 50% by mass or more, insulating properties are obtained. The surface smoothness on the polycarbonate film (hereinafter sometimes referred to as “smoothness”) is good, and the transmittance is 97% or more and haze is 0.5 or less. A cured coating film was obtained. Moreover, from Examples 1-22, when (meth) acrylic-type resin whose contact angle with a polycarbonate is 10 degrees or less was used, smoothness improved more. In particular, from Examples 1, 4 to 8, only (meth) acrylic resin having a contact angle with polycarbonate of 7 ° was used, and (C) component (meth) acrylated epoxy resin, (D) component When neither the (meth) acrylated urethane resin nor the flame retardant of the component (E) was blended, extremely excellent smoothness was obtained. From Examples 12 to 22, when (meth) acrylic resin having a contact angle with polycarbonate of 7 ° is used in an ultraviolet curable transparent resin composition in an amount of 50% by mass or more, (C) contact angle with polycarbonate Even if (meth) acrylated epoxy resin having a contact angle of more than 12 °, (D) (meth) acrylated urethane resin having a contact angle with polycarbonate exceeding 12 °, or (E) a flame retardant, Excellent smoothness was obtained without impairing the insulating properties.

  On the other hand, from Comparative Examples 1 to 4, when a (meth) acrylic resin having a contact angle with a polycarbonate of 13 ° or more is used, (C) component (meth) acrylated epoxy resin, (D) component Even if the (meth) acrylated urethane resin or the flame retardant of the component (E) was not blended, the surface of the cured coating film was distorted and smoothness was not obtained. From Comparative Examples 3 and 4, when using a (meth) acrylic resin having a contact angle with a polycarbonate of 12 ° or less, another (meth) acrylic resin having a contact angle with the polycarbonate of more than 12 ° As a result of mixing, when the contact angle as the (meth) acrylic resin mixture was 13 ° or more, smoothness was not obtained.

  Since the ultraviolet curable transparent resin composition of the present invention can form a coating film having excellent smoothness and good transparency to a polycarbonate film without impairing insulation properties, for example, on a wiring substrate or an electrode substrate for a touch panel. High utility value in the field of forming transparent insulating films.

Claims (5)

( A) ( meth) acrylic resin and (B) a photopolymerization initiator, an ultraviolet curable transparent resin composition comprising:
The (A) (meth) acrylic resin includes a (meth) acrylic resin that is a polymer of cyclohexyl (meth) acrylate, and contains the (A) (meth) acrylic resin in an amount of 50% by mass or more. An ultraviolet curable transparent resin composition for forming a coating film on a printed wiring board or a flexible wiring board of a polycarbonate substrate that is not surface-treated . The ultraviolet curable transparent resin composition according to claim 1, wherein the (A) (meth) acrylic resin is a polymer of cyclohexyl (meth) acrylate . The ultraviolet curable transparent resin composition according to claim 1 or 2 , wherein the (B) photopolymerization initiator includes an α-hydroxyketone photopolymerization initiator. The ultraviolet curable transparent resin composition according to any one of claims 1 to 3 , wherein the (B) photopolymerization initiator includes an α-hydroxyketone photopolymerization initiator and an acylphosphine photopolymerization initiator. The printed wiring board which has a cured coating film obtained by apply | coating the ultraviolet curable transparent resin composition of any one of Claims 1 thru | or 4 .