JP2013082829A - Production method of alkali-soluble photosensitive resin, alkali-soluble photosensitive resin, and surface-mount type led - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a white reflecting film having high reflectance and having stable reflectance with the lapse of time, and to provide an LED light source having the white reflecting film.SOLUTION: There is disclosed the production method of an alkali-soluble photosensitive resin which is used for the LED light source which has a white reflecting film and an LED chip or an LED package on a board having a wiring pattern formed thereon, wherein the white reflecting film is formed of a white reflecting film-forming material containing an alkali-soluble photosensitive resin and a white pigment. In the method, an alkali-soluble photosensitive resin comprising a (meth)acrylic polymer (D) having a (meth)acryloyl group in a side chain is produced by esterification of a (meth)acrylic polymer (A) having a carboxy group (a1) and a hydroxy group (a2) with a compound (B) having a glycidyl group (b1) and a (meth)acrylic group (b2) in the presence of a quaternary phosphonium salt (C).

Description

  The present invention relates to a method for producing an alkali-soluble photosensitive resin useful for a white reflective film of a surface-mounted LED having a white reflective film and an LED (light emitting diode) chip or an LED package. The present invention also relates to a method for producing an alkali-soluble photosensitive resin having excellent reflectance stability over time.

  A surface mount type LED lamp (see Patent Document 1) mounted with an LED chip mounted on a circuit board and provided with a white reflective film, or an LED package mounted on a circuit board and provided with a white reflective film Further, a surface-mounted LED (see Patent Document 2) is known.

  This white reflective film is generally formed on the surface of the substrate on which the wiring pattern is formed, except for the LED chip or LED package mounting position and its connection pads. As a method for providing such a white reflective film, generally, a resin-coated white film-forming material is applied on a substrate, followed by heating and drying to form a coating film. A photolithographic method is known in which a film for forming a pattern is attached to a coating film, exposed, and developed. As this developing solution, an alkali developing type using a weak alkaline aqueous solution that does not volatilize organic substances is mainly used.

  Photoreactivity is required for the white film forming material used in the photolithographic method, and an alkali-soluble photosensitive resin made of a polymer having a (meth) acryloyl group in the side chain is generally used. Various methods have been proposed for preparing a polymer having a (meth) acryloyl group in the side chain. For example, a reaction product obtained by reacting a novolak epoxy resin with an unsaturated monocarboxylic acid and further adding a polybasic acid anhydride is widely used (see Patent Document 3). Also known is a method for producing a polymer having a carboxyl group by reacting a compound having a glycidyl group and a (meth) acryl group in the presence of an esterification catalyst. Examples of the esterification catalyst used in the reaction include tertiary amines such as dimethylbenzylamine, triethylamine, tetramethylethylenediamine and tri-n-octylamine, 4 such as tetramethylammonium chloride, tetramethylammonium bromide and tetrabutylammonium bromide. Secondary ammonium salts, alkylureas such as tetramethylurea, alkylguanidines such as tetramethylguanidine, metal compounds such as cobalt naphthenate, organometallic complexes, and phosphines such as triphenylphosphine are used. (See Patent Documents 4 and 5)

JP2003-23183 JP 2009-194222 A JP-A 61-243869 JP 11-249300 A JP 2003-119228 A

  However, the polymer having a (meth) acryloyl group in the side chain obtained by the method described in Patent Document 3 has a problem in light resistance because it has a benzene ring skeleton. Further, when a polymer having a (meth) acryloyl group in the side chain obtained by the methods described in Patent Documents 4 and 5 is used as an alkali-soluble photosensitive resin for a white reflective film forming material of a surface-mounted LED In addition, there is a problem that the reflectance of the white reflective film is low and the reflectance decreases with time.

  The problem to be solved by the present invention is to provide a white reflective film having a high reflectance and a stable reflectance over time, and to provide a surface-mounted LED having such a white reflective film. is there.

  In order to solve the above-mentioned problems, the present inventors diligently studied and as a result, (meth) acrylic polymer (A) having a carboxyl group (a1) and a hydroxyl group (a2), and a glycidyl group (b1). And a white reflective film-forming material containing an alkali-soluble photosensitive resin obtained by reacting a compound (B) having a (meth) acrylic group (b2) in the presence of a specific esterification catalyst. The LED light source having a film has a high reflectance of the white reflective film, and as a result, contributes to improving the brightness of the LED, and the white reflective film is less discolored over time, so that these performances do not deteriorate. As a result, the present invention has been completed.

  That is, in order to solve the above-mentioned problems, the present invention provides (1) a white reflective film and a LED made of a white reflective film forming material containing an alkali-soluble photosensitive resin and a white pigment on a substrate on which a wiring pattern is formed. A method for producing an alkali-soluble photosensitive resin used in a surface-mounted LED having a chip or an LED package, the (meth) acrylic polymer (A) having a carboxyl group (a1) and a hydroxyl group (a2); A side chain characterized by esterifying the compound (B) having a glycidyl group (b1) and a (meth) acrylic group (b2) in the presence of a quaternary phosphonium salt (C). Provided is a method for producing an alkali-soluble photosensitive resin comprising a (meth) acrylic polymer (D) having an acryloyl group.

  In order to solve the above problems, the present invention provides (2) a white reflective film made of a white reflective film-forming material containing an alkali-soluble photosensitive resin and a white pigment on a substrate on which a wiring pattern is formed, or An alkali-soluble photosensitive resin used for a surface-mount type LED having an LED package, which is obtained by the production method described in (1) above.

  Furthermore, in order to solve the above-mentioned problems, the present invention provides (3) a white reflective film and an LED made of a white reflective film-forming material containing an alkali-soluble photosensitive resin and a white pigment on a substrate on which a wiring pattern is formed. A surface-mounted LED having a chip or an LED package, wherein the alkali-soluble photosensitive resin is an alkali-soluble photosensitive resin obtained by the production method described in (1) above. provide.

  According to the method for producing an alkali-soluble photosensitive resin of the present invention and the alkali-soluble photosensitive resin of the present invention, a white reflective film having high reflectance, small discoloration, and stable reflectance over time is provided. Therefore, it is possible to provide a surface-mounted LED that has excellent luminance characteristics and does not deteriorate in performance over time.

  The (meth) acrylic polymer (A) having a carboxyl group (a1) and a hydroxyl group (a2) used in the present invention is a (meth) acrylic acid ester, a monomer having a carboxyl group (a1), It can manufacture by polymerizing the monomer composition containing the monomer component containing the monomer which has a hydroxyl group (a2).

  Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and t-butyl (meth) ) Acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic acid alkyl esters such as lauryl (meth) acrylate; (meth) acrylic acid cycloalkyl esters such as cyclohexyl (meth) acrylate, and the like. It is not limited. Only one kind of these (meth) acrylic acid esters may be used, or two or more kinds may be used in combination.

  Among these (meth) acrylic acid esters, methyl methacrylate and (meth) acrylic acid esters mainly composed of methyl methacrylate are particularly preferable. A cured product obtained by polymerizing a monomer composition containing methyl methacrylate as a main component can further improve various physical properties such as weather resistance, transparency, surface gloss, appearance, safety, and the like. .

  The monomer having a carboxyl group (a1) is not particularly limited as long as it is a compound having a polymerizable double bond and a carboxyl group in the molecule. Examples of the monomer having a carboxyl group (a1) include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, and vinyl benzoic acid; non-monovalent acids such as maleic acid, fumaric acid, itaconic acid, and citraconic acid. Saturated dicarboxylic acids; monoesters of these unsaturated dicarboxylic acids, and the like. These monomers having a carboxyl group may be used alone or in combination of two or more.

  Although the usage-amount of the monomer which has a carboxyl group is not specifically limited, 10-80 mass% is preferable and a monomer composition is 100 mass%, 15-70 mass% is especially preferable, 20 -65 mass% is further more preferable. When the amount of the monomer having a carboxyl group is less than 0.5% by mass, the solubility in an alkaline aqueous solution is remarkably inferior, and the developability tends to be lowered. Also, the carboxyl group (a1) and hydroxyl group The number of polymerizable double bonds that can be introduced by reacting the (meth) acrylic polymer having the group (a2) with the compound (B) having the glycidyl group (b1) and the (meth) acrylic group (b2) is limited. However, it is not preferable because crosslinking due to light becomes insufficient and various physical properties such as sensitivity, resolution, and strength of the obtained cured product tend to decrease. When the amount of the monomer having a carboxyl group is more than 80% by mass, it is not preferable because electric properties, weather resistance and water resistance of the resulting cured product tend to be lowered.

  The monomer having a hydroxyl group (a2) is not particularly limited as long as it is a compound having a polymerizable double bond and a hydroxyl group in the molecule. Examples of the monomer having a hydroxyl group (a2) include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate and 4-hydroxybutyl acrylate; In addition to allyl compounds such as ethylene glycol monoallyl ether and propylene glycol monoallyl ether, polyethylene glycol mono (meth) acrylate, glycerol mono (meth) acrylate, and the like. Only one type of these monomers having a hydroxyl group (a2) may be used, or two or more types may be used in combination.

  Although the usage-amount of the monomer which has a hydroxyl group (a2) is not specifically limited, **-## mass% is preferable, ***-## mass%, considering a monomer composition as 100 mass%. ## mass% is particularly preferable, and *** to #### mass% is more preferable. When the amount of the monomer having a hydroxyl group (a2) is less than **% by mass, the property is remarkably inferior, the property tends to be lowered, and the carboxyl group ( a polymerizable double bond which can be introduced by reacting a compound (B) having a glycidyl group (b1) and a (meth) acrylic group (b2) with a (meth) acrylic polymer having a1) and a hydroxyl group (a2) This is not preferable because the number of the above compounds is limited, and crosslinking due to light becomes insufficient, and various physical properties such as sensitivity, resolution, and hot strength of the resulting cured product tend to decrease. When the amount of the monomer having a hydroxyl group (a2) exceeds ## mass%, the cured product obtained tends to deteriorate in properties,. Absent.

  In addition to the (meth) acrylic acid ester, the monomer having a carboxyl group (a1) and the monomer having a hydroxyl group (a2), the monomer composition includes a carboxyl group (a1) and a hydroxyl group ( A vinyl compound (monomer) not containing a2) can be included as necessary. Such a vinyl compound is not particularly limited as long as it is a compound having a polymerizable double bond. Examples of such vinyl compounds include styrene monomers such as styrene, α-methylstyrene, vinyltoluene, and chlorostyrene; vinyl esters such as vinyl acetate; (meth) acrylamide; (meth) acrylonitrile; N-methoxy. N-alkoxy substituted (meth) acrylamides such as methyl acrylamide and N-ethoxymethyl acrylamide; unsaturated basic monomers; maleimide monomers such as N-phenylmaleimide, N-cyclohexylmaleimide, N-isopropylmaleimide, etc. Is mentioned. Only one kind of these vinyl compounds may be used as required, or two or more kinds may be used in combination. When the vinyl compound is mixed with the monomer composition, the content of the vinyl compound is preferably 50% by mass or less, although it depends on the type of vinyl compound and the combination with the (meth) acrylic acid ester.

  When polymerizing the monomer composition, it is desirable to use a polymerization initiator. Examples of the polymerization initiator include benzoyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxide, t-butyl peroxy-2-ethyl hexanoate, t-butyl peroxy octoate, t-butyl peroxy benzoate, cumene hydro Organic peroxides such as peroxide, cyclohexanone peroxide, dicumyl peroxide, bis (4-t-butylcyclohexyl) peroxydicarbonate; 2,2′-azobisisobutyronitrile, 2-phenylazo-2, Examples include, but are not limited to, azo compounds such as 4-dimethyl-4-methoxyvaleronitrile. These polymerization initiators may be used alone or in combination of two or more. The addition amount of the polymerization initiator with respect to the monomer composition is not particularly limited, but is preferably in the range of 1 to 10% by mass, particularly in the range of 2 to 8% by mass with respect to the monomer composition. preferable.

  Moreover, when polymerizing the monomer composition, a chain transfer agent may be added in order to adjust the average molecular weight and the like of the obtained polymer. Although it does not specifically limit as a chain transfer agent, The thiol compound is especially preferable from the point which can control a polymerization reaction very easily. Examples of the thiol compound used as a chain transfer agent include alkyl mercaptans such as t-butyl mercaptan, n-octyl mercaptan and n-dodecyl mercaptan; aromatic mercaptans such as thiophenol and thionaphthol; thioglycolic acid; octyl thioglycolate Thioglycolic acid alkyl esters such as ethylene glycol dithioglycolate, trimethylolpropane tris- (thioglycolate), pentaerythritol tetrakis- (thioglycolate); β-mercaptopropionic acid; octyl β-mercaptopropionic acid, 1, 4-butanediol di (β-thiopropionate), trimethylolpropane tris- (β-thiopropionate), pentaerythritol tetrakis- (β-thiopropionate) Examples of such β-mercaptopropionic acid alkyl esters include, but are not limited to. Only one kind of these chain transfer agents may be used, or two or more kinds may be used in combination.

  The amount of the chain transfer agent used may be appropriately set according to the type of the chain transfer agent and the combination with the monomer in the polymerizable composition, and is not particularly limited. The range of 0.1-15 mass% with respect to a composition is preferable.

  Examples of the polymerization method of the polymerizable composition include known polymerization methods such as bulk polymerization (bulk polymerization), solution polymerization, suspension polymerization, and emulsion polymerization, and solution polymerization is particularly preferable. In addition, when employ | adopting suspension polymerization, the method of suspending a monomer component in dispersion media, such as water, can be employ | adopted using dispersion stabilizers, such as polyvinyl alcohol. Polymerization reaction conditions such as polymerization reaction temperature and polymerization reaction time are not particularly limited, and for example, known polymerization reaction conditions can be employed. The above polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen gas.

  The mass average molecular weight (Mw) of the (meth) acrylic polymer (A) having a carboxyl group (a1) and a hydroxyl group (a2) obtained by the above method is preferably in the range of 5,000 to 180,000. A range of 5,000 to 150,000 is particularly preferred. When the weight average molecular weight (Mw) of the (meth) acrylic polymer (A) having a carboxyl group (a1) and a hydroxyl group (a2) is smaller than 5,000, the resin blend composition is applied and dried. When the weight average molecular weight (Mw) of the (meth) acrylic polymer (A) having a carboxyl group (a1) and a hydroxyl group (a2) is larger than 180,000 , Because it tends to be inferior in developability and storage stability.

  The compound (B) having a glycidyl group (b1) and a (meth) acrylic group (b2) used in the present invention is a (meth) acrylic polymer (A) having a carboxyl group (a1) and a hydroxyl group (a2). There is no particular limitation as long as it is a compound having a glycidyl group (b1) capable of reacting with the carboxyl group (a1) and hydroxyl group (a2) and (meth) acrylic group (b2). The compound (B) having such a glycidyl group (b1) and (meth) acrylic group (b2) is roughly classified into a compound (B) having a structure in which a glycidyl group (b1) is bonded to an aliphatic hydrocarbon group. -1) and a compound (B-2) having a structure in which an epoxy group is formed on the alicyclic structure.

  Examples of the compound (B-1) having a structure in which a glycidyl group (b1) is bonded to the former aliphatic hydrocarbon group include glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate glycidyl ether, 2-hydroxy Propyl (meth) acrylate glycidyl ether, 3-hydroxypropyl (meth) acrylate glycidyl ether, 2-hydroxybutyl (meth) acrylate glycidyl ether, 4-hydroxybutyl (meth) acrylate glycidyl ether, 2-hydroxypentyl (meth) acrylate glycidyl And ether, 6-hydroxyhexyl (meth) acrylate glycidyl ether, and the like.

  Examples of the compound (B-2) having a structure in which an epoxy group is formed on the latter alicyclic structure include alicyclic compounds such as compounds represented by the following general formulas (3-1) to (3-15). Examples include compounds having an epoxy group and a (meth) acryl group (b2).

Formula (3-1)

Formula (3-2)

General formula (3-3)

Formula (3-4)

Formula (3-5)

Formula (3-6)

Formula (3-7)

General formula (3-8)

Formula (3-9)

Formula (3-10)

Formula (3-11)

Formula (3-12)

Formula (3-13)

Formula (3-14)

Formula (3-15)

(In the above general formulas (3-1) to (3-15), R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms, R ₃ represents a divalent carbon hydrogen group having 1 to 10 carbon atoms, and I represents an integer of 0 to 10).

  Of these compounds (B) having the glycidyl group (b1) and the (meth) acryl group (b2), glycidyl (meth) acrylate is particularly preferable. As the compound (B) having the glycidyl group (b1) and the (meth) acrylic group (b2), only one type may be used, or two or more types may be used in combination.

  The amount of the compound (B) having the glycidyl group (b1) and (meth) acryl group (b2) is the kind of the compound, the carboxyl group (a1) to be reacted, and the hydroxyl group (a2) (meth). What is necessary is just to set suitably according to the kind of acrylic polymer (A), Although it does not specifically limit, (meth) acrylic polymer (A) which has a carboxyl group (a1) and a hydroxyl group (a2) The ratio of the carboxyl group (a1) and the hydroxyl group (a2) of the glycidyl group (b1) of the compound (B) having the glycidyl group (b1) and the (meth) acrylic group (b2) is equivalent ratio ((( a1) + (a2)) / (b)), a range of 1.1 to 4.6 is preferred, and a range of 1.2 to 3.0 is particularly preferred.

  Esterification reaction of (meth) acrylic polymer (A) having carboxyl group (a1) and hydroxyl group (a2) with compound (B) having glycidyl group (b1) and (meth) acrylic group (b2) In this case, a quaternary phosphonium salt (C) is used as a catalyst. As the quaternary phosphonium salt (C) used as a catalyst, the general formula (1)

(Wherein R ¹ , R ² , R ³ and R ⁴ each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxymethyl group, a phenyl group or a benzyl group, and X ⁻ represents OH ^−. , Br ⁻ , Cl ⁻ , OCOCH ₃ ⁻ ,

Represents. )
The compound represented by these is mentioned. Among these compounds, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, methyltributylphosphonium phosphate, butyltriphenylphosphonium chloride, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, benzyl Triphenylphosphonium bromide, tetrabutylphosphonium hydroxide, tetraphenylphosphonium tetra p-tolylborate, tetrabutylphosphonium diethylphosphodithionate are preferred, tetrabutylphosphonium hydroxide, methyltributylphosphonium phosphate, tetraphenylphosphonium tetra p-tolylborate It is particularly preferred. Only one kind of these compounds may be used, or two or more kinds may be used in combination.

  The amount of the catalyst used is the type, the (meth) acrylic polymer (A) having the carboxyl group (a1) and the hydroxyl group (a2), the glycidyl group (b1) and the (meth) acrylic group (b2). What is necessary is just to set suitably according to the combination with the compound (B) which has, etc., Although it does not specifically limit, The (meth) acrylic-type polymer (A) which has a carboxyl group (a1) and a hydroxyl group (a2) The range of 0.005-5 mass parts is preferable with respect to 100 mass parts, the range of 0.05-4 mass parts is especially preferable, and the range of 0.1-3 mass parts is still more preferable.

  When performing the esterification reaction, it is desirable to allow a polymerization inhibitor to coexist if necessary. Examples of such polymerization inhibitors include, but are not limited to, phenols such as hydroquinone, methylhydroquinone, t-butylhydroquinone, and p-methoxyphenol.

  Furthermore, an antioxidant can be used in the white reflective film forming material of the present invention as necessary. Examples of such antioxidants include, but are not limited to, hindered phenols and hindered amines. These antioxidants may be present together during the esterification reaction or may be added after the reaction.

  Moreover, when performing said esterification reaction, a solvent can be used as needed. The solvent used for the esterification reaction is preferably a high-boiling alcohol solvent (E) having a boiling point in the range of 120 to 300 ° C. As such a high boiling alcohol solvent (E), for example, the general formula (2)

(In the formula, R ⁵ represents a hydrogen atom, a methyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, or a hexyl group, and R ⁶ represents an ethane-1,2-diyl group, propane-1,2- A diyl group or a butane-1,2-diyl group, a 3-methylbutane-1,3-diyl group, and n represents 1-3.)
The solvent represented by these is preferable. Among such solvents, dipropylene glycol methyl ether, diethylene glycol methyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, and 3-methoxy-3-methyl-1-butanol are particularly preferable. Only one kind of these solvents may be used, or two or more kinds may be used in combination. Moreover, a solvent other than an alcohol solvent can be used in combination with the high boiling alcohol solvent (E).

  The double bond equivalent of the (meth) acrylic polymer having a (meth) acrylic group in the side chain which is the reaction product obtained as described above is preferably in the range of 250 to 1,000, 330 to 430. A range is particularly preferred. In addition, in the present invention, the above-mentioned double bond equivalent represents the mass of the polymer per mole of (meth) acryl group, and the unit thereof is g / mol. Specifically, [double bond equivalent of compound (B) having glycidyl group (b1) and (meth) acrylic group (b2)] / [glycidyl group (b1) and (meth) acrylic group in 1 g of polymer Charged mass of compound (B) having (b2)] (however, [double bond equivalent of compound (B) having glycidyl group (b1) and (meth) acrylic group (b2)]) = [glycidyl group (b1) And (formula weight of compound (B) having (meth) acrylic group (b2)] / [compound having glycidyl group (b1) and (meth) acrylic group (b2) (B) (meth) acrylic group in one molecule The number of (b2)]). The smaller the double bond equivalent value, the higher the (meth) acryl group concentration in the polymer. In the present invention, the double bond equivalent is a theoretical value calculated from the amount of raw material charged. If the double bond equivalent is less than 250, gelation tends to occur during the esterification reaction, which is not preferable. On the other hand, when the double bond equivalent exceeds 1,000, crosslinking by light becomes insufficient and sensitivity and resolution are lowered, which is not preferable.

  The acid value of the (meth) acrylic polymer having a (meth) acryloyl group in the side chain, which is the reaction product obtained as described above, is preferably in the range of 50 to 200 mgKOH / g, and 70 to 150 mgKOH / g. A range is particularly preferred. When the acid value is less than 50 mgKOH / g, it tends to be difficult to remove with an alkaline developer, which is not preferable. Moreover, when the said acid value exceeds 200 mgKOH / g, since it exists in the tendency for the water resistance of a solder resist and an electrical property to be inferior, it is unpreferable.

  Examples of the white pigment used in the present invention include titanium oxide, zinc oxide, basic carbonate, basic lead sulfate, lead sulfate, zinc sulfide, antimony oxide, titanium nitride, cerium fluoride, and cerium oxide. Titanium oxide is preferable in terms of hiding power and nontoxicity.

  The mixing ratio of the (meth) acrylic polymer having a (meth) acryloyl group in the side chain in the white reflective film forming material and the white pigment is the same as the (meth) acrylic weight having the (meth) acryloyl group in the side chain. The range of 50 to 300 parts by mass is preferable with respect to 100 parts by mass of the coalescence, and the range of 60 to 260 parts by mass is particularly preferable. If the amount of the white pigment exceeds 300 parts by mass, the photocurability is lowered and the curing depth tends to be lowered, which is not preferable. On the other hand, if the amount of the white pigment is less than 50 parts by mass, the hiding power is small, and it tends to be difficult to obtain a white reflective film having a high reflectance.

  In the white reflective film forming material, a photopolymerization initiator, a photosensitizer, an epoxy compound, and a diluent can be used in combination.

  Examples of the photopolymerization initiator used for the white reflective film forming material include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone , 2,2-diethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, acetophenones such as 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] -1- [4- (4-morpholine L) Aminoalkylphenones such as phenyl] -1-butanone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, anthraquinones such as 1-chloroanthraquinone; 2,4-dimethylthioxanthone, 2, Thioxanthones such as 4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; benzophenones such as benzophenone; xanthones; (2,6-dimethoxybenzoyl) -2,4,4-pentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldipheny Phosphine oxide, such as phosphine oxides ethyl-2,4,6-trimethyl benzoyl phenyl phosphinothricin Nate; various peroxides, and the like titanocene initiators. These photopolymerization initiators can be used alone or in combination of two or more.

  These photopolymerization initiators can be used in combination with a photosensitizer. Examples of such a photosensitizer include N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, and triethanolamine. Secondary amines and the like.

  The amount of the photopolymerization initiator used is preferably in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer having a (meth) acryloyl group in the side chain. Moreover, the usage-amount in the case of using a photosensitizer together has the preferable range of 0.1-20 mass parts with respect to 100 mass parts of (meth) acrylic-type polymers which have a (meth) acryloyl group in a side chain.

  Examples of the epoxy compound used for the white reflective film forming material include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, and bisphenol S novolak type. Epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, resorcin / cresol co-condensation novolac type epoxy resin, alicyclic epoxy resin, trisphenol methane type epoxy resin, rubber modified epoxy resin, tris (2,3-epoxy Propyl) isocyanurate, diphenyl diglycidyl ether, tetramethyl diphenyl diglycidyl ether, epoxy resin containing oxazolidone ring, dicyclopen Polyglycidyl ethers of the polyaddition reaction product of an unsaturated alicyclic compound and a phenol diene, and the like. When the epoxy compound is used in combination, the amount used is preferably in the range of 5 to 70 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer having a (meth) acryloyl group in the side chain.

  Examples of the diluent used for the white reflective film forming material include a photopolymerizable monomer and / or an organic solvent. Examples of the photopolymerizable monomer include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxybutyl acrylate; mono- or diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; Acrylamides such as N, N-dimethylacrylamide and N-methylolacrylamide; aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate; hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, tris-hydroxyethylisocyanate Polyhydric alcohols such as nurate or polyacrylic acids of these ethylene oxide or propylene oxide adducts Acrylates such as phenoxy acrylate, bisphenol A diacrylate, and ethylene oxide or propylene oxide adducts of these phenols; glycidyl ether acrylates such as glycerin diglycidyl ether and trimethylolpropane triglycidyl ether; Melamine acrylate; and / or methacrylates corresponding to the above acrylates. The amount of the photopolymerizable monomer used as a diluent is preferably in the range of 20 to 300 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer having a (meth) acryloyl group in the side chain.

  Examples of the organic solvent used for the white reflective film forming material include aromatic hydrocarbons such as toluene and xylene; alcohols such as methanol and isopropyl alcohol; esters such as ethyl acetate and butyl acetate; 1,4-dioxane and tetrahydrofuran. Ethers such as: methyl ketones such as methyl ethyl ketone and methyl isobutyl ketone; cellosolve, butyl cellosolve, cellosolve acetate, carbitol, ethyl carbitol, butyl carbitol, and other alkylene polyols such as alkylene glycol and propylene glycol, of these alkylene polyols Glycol esters such as alkyl esters and ethers of alkyl ethers, esters; alicyclic hydrocarbons such as cyclohexanone and cyclohexanol, and petroleum ethers; Such as such as petroleum solvent oil naphtha. These organic solvents can be used alone or in combination of two or more. The amount of organic solvent used as a diluent is preferably in the range of 4 to 500 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer having a (meth) acryloyl group in the side chain.

  The white reflective film is prepared by applying the white reflective film forming material prepared as described above onto the substrate surface on which the wiring pattern is formed, drying the organic solvent as necessary, and then heating and curing. Alternatively, it is formed by photocuring. It is applied by methods such as screen coating, curtain coating, spray coating, roll coating, and the like, and is tack-free and uniform by evaporating and drying the organic solvent contained in the composition at a temperature of 70 to 90 ° C., for example. Can be formed. Then, the white reflective film of this invention can be obtained by exposing with an active energy ray selectively through a photomask, and developing an unexposed part with dilute alkaline aqueous solution, and forming a resist pattern. The dilute alkaline aqueous solution used here is generally 0.5 to 5% by mass of sodium carbonate aqueous solution, but other alkaline use liquids can also be used. Examples of other dilute alkaline aqueous solutions include alkaline aqueous solutions of potassium hydroxide, sodium hydroxide, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, and the like.

  As an irradiation light source for exposure, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, a metal halide lamp, or the like can be used. In addition, a laser beam can also be used as an actinic beam. In order to improve the heat resistance of the white reflective film thus obtained, it is desirable to secondarily cure the white reflective film with heat of 100 to 200 ° C., ultraviolet rays or far infrared rays.

  The surface-mount type LED of the present invention can be manufactured, for example, by the following method. That is, the white reflective film is provided on the surface side of the substrate according to the above method except for the portion where the LED chip or LED package is mounted and the portion where the wire for wiring the LED chip or LED package is attached. Thereafter, a terminal is provided on the back side of the substrate so that the circuit board can be surface-mounted, and the circuit pattern and the terminal are electrically connected through a through-hole of the substrate, and then the LED chip or In this method, an LED package is mounted and, if necessary, a cover case made of a transparent resin is provided on the surface side of the substrate. The white reflective film of the present invention is not limited to the surface-mounted LED manufactured by such a method. If the surface-mounted LED can be expected to have the effect of the white reflective film of the present invention, It can be applied without particular limitation.

Next, the present invention will be specifically described using examples and comparative examples. In the examples, “parts” means parts by mass unless otherwise specified. Further, the molecular weight and molecular weight distribution of the (meth) acrylic polymer obtained were determined by the following GPC analysis.

Measuring device: HLC-8120GPC manufactured by Tosoh Corporation
Column: TSK-GUARDCOLUMN HXL-H manufactured by Tosoh Corporation
+ Tosoh Corporation TSK-GEL G5000HXL
+ Tosoh Corporation TSK-GEL G4000HXL
+ Tosoh Corporation TSK-GEL G3000HXL
+ Tosoh Corporation TSK-GEL G2000HXL
Detector: RI (differential refractometer)
Data processing: Multi-station GPC-8020 model II manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate 1.0 ml / min Standard: Monodispersed polystyrene Sample: 0.5 mass% tetrahydrofuran solution filtered in terms of resin solids, filtered through a microfilter (100 μl)

[Synthesis Example 1]
After introducing 900 parts of diethylene glycol dimethyl ether (“Dawanol DPM” manufactured by Dow Chemical) into a flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel, and a nitrogen introducing tube, and raising the temperature to 110 ° C., methacrylic acid 278 parts, 161 parts of methyl methacrylate, 47 parts of 2-hydroxyethyl acrylate and 17 parts of t-butyl peroxy-2-ethylhexanoate (“Perbutyl O” manufactured by NOF Corporation) were added dropwise over 3 hours. After completion of the dropwise addition, the mixture was aged for 4 hours to obtain a polymer having a carboxy group and an alcoholic hydroxyl group. The weight average molecular weight (Mw) measured using GPC (gel permeation chromatography) of the polymer thus obtained was 7,600.

  Next, 0.4 parts of p-methoxyphenol as a polymerization inhibitor and 2.2 parts of dibutylhydroxytoluene as an antioxidant are added to the above polymer, 288 parts of glycidyl methacrylate, and tetrabutylphosphonium hydroxide as a catalyst. After adding 0 part, esterification reaction was performed at 110 degreeC over 4 hours, and the methacrylic polymer (D-1) which has a (meth) acryloyl group in a side chain was obtained.

  The methacrylic polymer (D-1) thus obtained had a weight average molecular weight (Mw) of 80,500 measured using GPC (gel permeation chromatography) and a molecular weight distribution (Mw / Mn). Was 46, the double bond equivalent was 359 g / mol, the solid content was 46 mass%, and the acid value was 52 mgKOH / g.

[Synthesis Example 2]
In Example 1, a methacrylic polymer having a (meth) acryloyl group in the side chain in the same manner as in Example 1 except that 2.0 parts of methyltributylphosphonium chloride was used instead of tetrabutylphosphonium hydroxide. (D-2) was obtained.

  The methacrylic polymer (D-2) thus obtained had a weight average molecular weight (Mw) of 71,400 measured using GPC (gel permeation chromatography) and a molecular weight distribution (Mw / Mn). Was 44, the double bond equivalent was 359 g / mol, the solid content was 46% by mass, and the acid value was 54 mgKOH / g.

[Synthesis Example 3]
In Example 1, a methacrylic polymer (D-3) having a (meth) acryloyl group in the side chain was obtained in the same manner as in Example 1 except that 900 parts of methoxypropyl acetate was used instead of diethylene glycol dimethyl ether. Obtained.

  The methacrylic polymer (D-3) thus obtained had a weight average molecular weight (Mw) of 79,000 measured using GPC (gel permeation chromatography) and a molecular weight distribution (Mw / Mn). Was 49, the double bond equivalent was 359 g / mol, the solid content was 46% by mass, and the acid value was 51 mgKOH / g.

[Synthesis Example 4]
In Example 1, instead of 2-hydroxyethyl acrylate, side chains were used in the same manner as in Example 1 except that 99 parts of lactone-modified 2-hydroxyethyl methacrylate (Plexel FM1 manufactured by Daicel Chemical Industries, Ltd.) was used. A methacrylic polymer (D-4) having a (meth) acryloyl group was obtained.

  The methacrylic polymer (D-4) thus obtained had a weight average molecular weight (Mw) of 68,000 measured using GPC (gel permeation chromatography) and a molecular weight distribution (Mw / Mn). Was 45, the double bond equivalent was 408 g / mol, the solid content was 48 mass%, and the acid value was 48 mgKOH / g.

[Comparative Synthesis Example 1]
In Example 1, instead of tetrabutylphosphonium hydroxide, 4.0 parts of triphenylphosphine was used, and the esterification reaction was performed at 110 ° C. for 8 hours. A methacrylic polymer (D′-1) having a (meth) acryloyl group was obtained.

  The methacrylic polymer (D′-1) thus obtained had a weight average molecular weight (Mw) of 25,900 measured using GPC (gel permeation chromatography) and a molecular weight distribution (Mw / Mn). ) Was 16, the double bond equivalent was 359 g / mol, the solid content was 46% by mass, and the acid value was 56 mgKOH / g.

[Comparative Synthesis Example 2]
Into a 2 liter flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen inlet tube, 900 parts of diethylene glycol dimethyl ether was introduced, and after raising the temperature to 110 ° C., 204 parts of methacrylic acid, 281 parts of methyl methacrylate and t- 17 parts of butyl peroxy 2-ethylhexanoate (“Perbutyl O” manufactured by NOF Corporation) was added dropwise. After the dropwise addition, aging was performed to obtain a polymer having a carboxy group. The weight average molecular weight measured using GPC (gel permeation chromatography) of the polymer thus obtained was 8,500.

  Next, 0.4 parts of p-methoxyphenol as a polymerization inhibitor and 2.2 parts of dibutylhydroxytoluene as an acid value inhibitor were added to the above polymer, followed by 292 parts of glycidyl methacrylate and tetrabutylphosphonium hydroxide as a catalyst. 2.0 parts was added and esterification was performed at 110 ° C. for 4 hours to obtain a methacrylic polymer (D′-2) having a (meth) acryloyl group in the side chain.

  The methacrylic polymer (D′-2) thus obtained had a weight average molecular weight (Mw) of 56,000 measured using GPC (gel permeation chromatography) and a molecular weight distribution (Mw / Mn). ) Was 37, the double bond equivalent was 378 g / mol, the solid content was 46% by mass, and the acid value was 47 mgKOH / g.

[Examples 1-4, Comparative Examples 1-2]
Each component shown in Table 1 was mixed with a rotating / revolving mixer to obtain a solder resist composition. The numbers in the table indicate parts by mass.

R-820: Titanium oxide epiclone 850S manufactured by Ishihara Sangyo Co., Ltd .: Bisphenol A type epoxy resin Irgacure 907 manufactured by DIC Co., Ltd. Photopolymerization initiator “Irgacure 907” manufactured by Ciba Specialty Chemicals
Lucillin TPO: Photopolymerization initiator “Lucirin TPO” manufactured by BASF
DPHA: dipentaerythritol hexaacrylate 2E4MZ: imidazole curing accelerator manufactured by Shikoku Kasei Co., Ltd.

[Evaluation]
-Touch drying property After applying the composition obtained in each example and each comparative example on a glass plate to a film thickness of 50 μm using an applicator, it was heated at 80 ° C. in a hot air circulating drying oven. The coating immediately after drying for 30 minutes was evaluated for dryness (tack) at the time of touching according to the following criteria, and the results are shown in Table 2.

○: No tack △: There is some tack ×: There is tack

-Drying control width The composition obtained in each example and each comparative example was applied to the entire surface of the glass plate with an applicator so as to have a film thickness of 50 μm, and at 80 ° C. for 30 minutes, 40 minutes, 50 minutes, After drying in a hot air circulation drying oven for 60 minutes, 1% sodium carbonate aqueous solution was used as a developer and developed with a shaker for 180 seconds at 30 ° C., and the degree of remaining on the substrate was evaluated according to the following criteria. The results are shown in Table 2.

○: No coating film is left on the substrate. (Coating film residual rate: 0%)
Δ: A part of the coating film on the substrate remains. (Coating film residual ratio: 1 to 10%)
X: The coating film on the substrate is not dissolved and almost remains. (Coating film residual ratio: 11 to 100%)

-Sensitivity The composition obtained in each Example and each Comparative Example was applied to the entire surface of the glass plate with an applicator so as to have a film thickness of 50 μm. Thereafter, Step Tablet No. 2 (manufactured by Kodak Co., Ltd.) was placed on the coating film dried at 80 ° C. for 30 minutes in a hot air circulation drying oven, and an exposure machine (US02-03001 manufactured by Eye Graphics Co., Ltd.) was placed. Using a 1% sodium carbonate aqueous solution as a developer, developing it with a shaker for 180 seconds at a temperature of 180 mJ / cm ² , and evaluating with the step tablet method. It is shown in Table 2. The numbers in the table indicate the number of steps of the step tablet. The larger the number, the better the curability (sensitivity).

The composition obtained in each example and each comparative example was applied on the entire surface of the glass plate to a film thickness of 50 μm using an applicator, and then dried at 80 ° C. for 30 minutes in a hot air circulation drying oven. A specimen was obtained. This test piece was exposed to UV light with an integrated light amount of 800 mJ / cm ² using an exposure machine (US02-03001 manufactured by iGraphics Co., Ltd.), and then 1% sodium carbonate aqueous solution as a developer at 30 ° C. Development was carried out on a shaker for 180 seconds, followed by heat curing at 150 ° C. for 60 minutes in a hot-air circulating drying oven to prepare a cured test piece. The color difference of the obtained cured test piece was measured using ZE2000 made by Nippon Denshoku Industries Co., Ltd. The results are shown in Table 3.

-Heat resistance The obtained cured test piece is heated to 200 ° C in a hot-air circulating drying oven to accelerate deterioration, and the cured test piece is taken out after 30 minutes, 60 minutes and 90 minutes, and the color difference is similarly obtained. Was measured. The results are shown in Tables 4-6.

· Light resistance obtained cured specimen was accelerated deterioration by irradiation with UV light of ^{60J / cm 2, 90J / cm} 2 and 120 J / cm ² in UV exposure apparatus (output 100 mW / cm ² metal halide lamps), similar The color difference was measured. The results are shown in Tables 7-9.

  In Tables 3 to 9, Y represents the reflectance of the XYZ color system, and L * represents the lightness of the L * a * b * color system. a * indicates the red direction, -a * indicates the green direction, b * indicates the yellow direction, and -b * indicates the blue direction. The closer to zero, the lower the saturation. ΔE indicates a change in color. A smaller value indicates a smaller color change.

  From the results shown in Tables 4 to 9, in Examples 1 to 4 using the composition of the present invention, the reflectance does not decrease even after accelerated deterioration, and the value of ΔE which is a color change is small. I understand.

Claims (9)

Alkaline acceptable for use in a surface-mounted LED having a white reflective film made of a white reflective film-forming material containing an alkali-soluble photosensitive resin and a white pigment and an LED chip or LED package on a substrate on which a wiring pattern is formed. A method for producing a soluble photosensitive resin, comprising:
A (meth) acrylic polymer (A) having a carboxyl group (a1) and a hydroxyl group (a2) and a compound (B) having a glycidyl group (b1) and a (meth) acrylic group (b2) are quaternized. A method for producing an alkali-soluble photosensitive resin comprising a (meth) acrylic polymer (D) having a (meth) acryloyl group in a side chain, wherein the esterification reaction is carried out in the presence of a phosphonium salt (C). The quaternary phosphonium salt (C) has the general formula (1)

(Wherein R ¹ , R ² , R ³ and R ⁴ each independently represents an alkyl group having 1 to 5 carbon atoms, an alkoxymethyl group having 1 to 5 carbon atoms, a phenyl group or a benzyl group. , X ⁻ represents OH ⁻ , Br ⁻ , Cl ⁻ , OCOCH ₃ ⁻ ,

Represents. )
The method for producing an alkali-soluble photosensitive resin according to claim 1, wherein the compound is represented by the formula:   The method for producing an alkali-soluble photosensitive resin according to claim 1, wherein the quaternary phosphonium salt (C) is selected from the group consisting of tetrabutylphosphonium hydroxide, methyltributylphosphonium phosphate and tetraphenylphosphonium tetra p-tolylborate.   2. The alkali-soluble photosensitivity according to claim 1, wherein the (meth) acrylic polymer (A) having the carboxyl group (a1) and the hydroxyl group (a2) is a polymer having a weight average molecular weight in the range of 5000 to 180000. For producing a functional resin.   The method for producing an alkali-soluble photosensitive resin according to claim 1, wherein the double bond equivalent is in the range of 250 to 1,000.   The method for producing an alkali-soluble photosensitive resin according to claim 1, wherein the solid acid value is in the range of 50 to 200 mgKOH / g.   The method for producing an alkali-soluble photosensitive resin according to claim 1, wherein the compound (B) having the glycidyl group (b1) and the (meth) acrylic group (b2) is glycidyl (meth) acrylate. Alkaline acceptable for use in a surface-mounted LED having a white reflective film made of a white reflective film-forming material containing an alkali-soluble photosensitive resin and a white pigment and an LED chip or LED package on a substrate on which a wiring pattern is formed. A melt-sensitive resin,
An alkali-soluble photosensitive resin obtained by the production method according to claim 1. In a surface-mount type LED having a white reflective film made of a white reflective film forming material containing an alkali-soluble photosensitive resin and a white pigment and an LED chip or an LED package on a substrate on which a wiring pattern is formed,
The surface-mount type LED, wherein the alkali-soluble photosensitive resin is an alkali-soluble photosensitive resin obtained by the production method according to any one of claims 1 to 7.