JP3252081B2 - Photopolymerizable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photopolymerizable composition and a photopolymerizable laminate, and more particularly to an alkali-developable photopolymerizable composition and a photopolymerizable laminate suitable for producing a printed circuit board.

[0002]

2. Description of the Related Art Conventionally, a so-called dry film resist (hereinafter referred to as DFR) comprising a support layer and a photopolymerizable layer has been used as a resist for producing a printed circuit. DF
R is generally prepared by laminating a photopolymerizable composition on a support film and, in many cases, further laminating a protective film on the composition. Such a photopolymerizable layer is generally of an alkali developing type using a weak alkaline aqueous solution as a developing solution.

In order to form a printed circuit board using a DFR, a protective film is first peeled off, and then a DFR is laminated using a laminator or the like on a permanent circuit forming substrate such as a copper-clad laminate, and a wiring pattern mask film is formed. And the like. Next, if necessary, the support film is peeled off, and the unpolymerized portion of the photopolymerizable composition is dissolved or dispersed and removed with a developer to form a cured resist image on the substrate. The metal surface of the substrate is etched or plated by using the formed resist image as a mask, and then the resist image is peeled off using an alkaline aqueous solution stronger than a developing solution to form a printed wiring board or the like. Particularly recently, the through-holes (through-holes) are covered with a cured film because of the simplicity of the process,
After that, a so-called tenting method of etching is often used. Cupric chloride, ferric chloride, copper-ammonia complex solution, etc. are used for etching, but if the cured film is broken by the pressure of spray or the like in the development or etching process, the internal conductor is removed and the wire breaks. It leads to failure. Therefore, the cured film is required to have strong film strength and flexibility. On the other hand, since the DFR is stored in a three-layer roll state, the photopolymerizable layer protrudes from the end face during storage,
A so-called cold flow phenomenon may occur, but this phenomenon is not preferable in handling.

If the unexposed photopolymerizable layer in the DFR is hard, the adhesiveness is poor when the photopolymerizable layer is laminated on a substrate, and the photopolymerizable layer can fill the unevenness on the uneven surface of the substrate. In some cases, a space may be created between the photopolymerizable layer and the substrate. When such a space is generated, the etching liquid permeates the substrate, and thus defects such as disconnection and chipping occur.

The photopolymerizable layer of DFR widely used at present includes (1) an unsaturated compound having at least one ethylenic group and capable of forming a polymer by a photopolymerization initiator;
It comprises a composition comprising (2) a thermoplastic organic polymer binder, (3) a photopolymerization initiator, and (4) other additives. (Japanese Patent Publication No. 50-9177, Japanese Patent Publication No. 5
No. 7-21697). As the unsaturated compound, acrylic acid and methacrylic acid esters of aliphatic polyhydric alcohols are most common, and at least two unsaturated compounds such as trimethylolpropane triacrylate pentaerythritol triacrylate and polyethylene glycol diacrylate are used. Those with groups are known.

[0006]

In order to improve the cold flow, the proportion of the binder in the photopolymerizable layer should be relatively increased. However, the followability of the photopolymerizable layer to the substrate can be improved. And the flexibility and strength of the tenting film decrease. Further, in order to improve the tenting film strength and the followability of the photopolymerizable layer to the substrate, the mixing ratio of the binder in the photopolymerizable layer may be relatively reduced. There is a problem that the peeling time increases. Therefore, a photopolymerizable composition that satisfies these characteristics simultaneously has been desired.

[0007]

As a result of intensive studies to solve the above problems, when a photopolymerizable composition using the following linear polymer (a) is used for DFR, a cured resist is obtained. Tent film strength is tough, cold flow property and followability of the photopolymerizable layer to the substrate are good, and it can be stored at room temperature for more than 6 months. The present invention has been completed.

That is, the present invention relates to (a) a resin for a binder comprising a linear copolymer A having a carboxyl group content of 100 to 600 in acid equivalent and a weight average molecular weight of 100,000 to 500,000; 20-90% by weight, (b) following general
A photopolymerizable unsaturated compound represented by the formula (I):
A photopolymerizable unsaturated compound represented by the general formula (II) ,
5 to 60% by weight, (c) photopolymerization initiator, 0.01 to 30
The present invention provides a photopolymerizable composition, characterized in that the composition contains 0.1% by weight.

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The present invention also relates to (a) a linear copolymer A having a carboxyl group content of 100 to 600 in acid equivalent and a weight average molecular weight of 100,000 to 500,000; Is a linear copolymer B having a phenyl group-containing vinyl compound having an acid equivalent of 100 to 600 and a weight average molecular weight of 30,000 to 90,000 as one of the copolymerization components.
, A resin for a binder mixed so that A / B is 90/10 to 10/90, 20 to 90% by weight,
(B) Photopolymerizable unsaturated compounds represented by the following general formula (I)
Photopolymerizable compound represented by the sum compound and the general formula (II)
An unsaturated compound , 5 to 60% by weight, (c) a photopolymerization initiator,
Provided is a photopolymerizable composition containing 0.01 to 30% by weight.

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The amount of carboxyl groups contained in the linear copolymer A constituting the binder resin (a) used in the present invention must be from 100 to 600 in terms of acid equivalent, and from 300 to 4
00 is preferred. The molecular weight of the linear copolymer A is 10 to 10.
It must be 500,000, more preferably 200,000 to 400,000. If the molecular weight of the linear copolymer A exceeds 500,000, the developability decreases, and if it is less than 100,000, the strength of the tenting film and the followability of the photopolymerizable layer to the substrate deteriorate.

Here, the acid equivalent refers to the weight of a polymer having one equivalent of a carboxyl group therein. The measurement of the acid equivalent is performed by a potentiometric titration method. The molecular weight is determined as a weight average molecular weight (in terms of polystyrene) by gel permeation chromatography (GPC). Further, the carboxyl group in the linear copolymer is necessary for giving the DFR developability and releasability to an aqueous alkali solution. When the acid equivalent is less than 100, the compatibility with the coating solvent or other composition such as a monomer is reduced, and
If it exceeds 0, the developability and the releasability deteriorate.

The linear copolymer A can be obtained by copolymerizing one or more of the following two types of monomers. The first monomer is a carboxylic acid or acid anhydride having one polymerizable unsaturated group in the molecule.
For example, (meth) acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, maleic acid half ester and the like. The second monomer is non-acidic, has one polymerizable unsaturated group in the molecule, and has various properties such as developability of the photopolymerizable layer, resistance in etching and plating steps, and flexibility of the cured film. Selected to retain properties. For example, methyl (meth) acrylate, ethyl (meth) acrylate,
There are alkyl (meth) acrylates such as butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate. Further, a vinyl compound having a phenyl group (eg, styrene) can also be used.

The linear copolymer A is capable of following even when used alone.
Although the adhesiveness is good, more rapid development processing becomes possible by using it together with the linear copolymer B. When used together, the A / B (weight ratio) is 90/10 to 10/90.
It is. The amount of the carboxyl group contained in the linear copolymer B used in the present invention needs to be 100 to 600 as an acid equivalent, and preferably 300 to 400. In addition, linear copolymer B
Must have a molecular weight of 30,000 to 90,000. Linear copolymer B
If the molecular weight exceeds 90,000, the developability decreases, and if it is less than 30,000, the tenting film strength and the cold flow property deteriorate.

Here, the acid equivalent means the weight of a polymer having one equivalent of a carboxyl group therein. The measurement of the acid equivalent is performed by a potentiometric titration method. The molecular weight is determined as a weight average molecular weight (in terms of polystyrene) by gel permeation chromatography (GPC). Further, the carboxyl group in the linear copolymer is necessary for giving the DFR developability and releasability to an aqueous alkali solution. When the acid equivalent is less than 100, the compatibility with the coating solvent or other composition such as a monomer is reduced, and
If it exceeds 0, the developability and the releasability deteriorate.

The linear copolymer B can be obtained by copolymerizing a monomer selected from the above monomers in the same manner as A,
A vinyl compound having a phenyl group is an essential component. Styrene is preferred as the vinyl compound. The amount of the resin for binder (a) contained in the photopolymerizable composition of the present invention is in the range of 20 to 90% by weight, preferably 30 to 70% by weight.
% By weight. When the amount of the binder resin (a) is less than 20% by weight or more than 90% by weight, the cured image formed by the exposure has sufficient properties as a resist, for example, sufficient resistance in tenting, etching and various plating steps. Do not have.

Examples of the photopolymerization initiator (c) that can be used in the present invention include known photopolymerization initiators that are activated by various actinic rays, for example, ultraviolet rays, and start polymerization. As such a photopolymerization initiator, for example, 2
-Ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3 diphenylanthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 2-methylanthraquinone, Quinones such as 4,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, 3-chloro-2-methylanthraquinone, benzophenone, Michler's ketone [4,4'-bis (dimethylamino) ) Benzophenone], aromatic ketones such as 4,4′-bis (diethylamino) benzophenone, benzoin, benzoin ethyl ether, benzoin phenyl ether, methyl benzoin, ethyl benzoin Benzoin ethers such as down, benzyl dimethyl ketal, benzyl diethyl ketal, 2-(o over-chlorophenyl) over 4,5 over diphenyl imidazolylmethyl dimers such biimidazole compounds of the combination of thioxanthones and alkylamino benzoic acid,
For example, a combination of ethylthioxanthone and ethyl dimethylaminobenzoate, a combination of 2-chlorothioxanthone and ethyl dimethylaminobenzoate, a combination of isopropylthioxanthone and ethyl dimethylaminobenzoate, or 2- (ο
-Chlorophenyl) -4,5 diphenylimidazolyl dimer and Michler's ketone, acridines such as 9-phenylacridine, 1-phenyl-1,2
Oxime esters such as -propanedione-2-o-benzoyl oxime, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, and the like. Preferred examples of these photopolymerization initiators include thioxanthones such as diethylthioxanthone and chlorothioxanthone, dialkylaminobenzoates such as ethyl dimethylaminobenzoate, benzophenone, 4,
4'-bis (dimethylamino) benzophenone, 4,
4'-bis (diethylamino) benzophenone, 2- (o-chlorophenyl) -4,5 diphenylimidazolyl dimer, and combinations thereof.

As the photopolymerizable unsaturated compound (b) constituting the photopolymerizable composition of the present invention, a photopolymerizable monomer having at least two terminal ethylene groups is preferably used. Examples thereof include 1,6-hexanediol di (meth) acrylate, 1,4-cyclohexanediol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and polyoxyethylene poly. Polyoxyalkylene glycol di (meth) acrylates such as oxypropylene glycol di (meth) acrylate, 2-di (p-hydroxyphenyl) propane di (meth) acrylate, glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate , Polyoxypropyltrimethylolpropane tri (meth) acrylate, polyoxyethyltrimethylolpropane triacrylate, dipentaerythritol penta (meth) acrylate, Limethylolpropane triglycidyl ether tri (meth) acrylate,
Examples include bisphenol A diglycidyl ether di (meth) acrylate, 2,2-bis (4-methacryloxypentaethoxyphenyl) propane, and a polyfunctional (meth) acrylate containing a urethane group.

Preferred examples include those represented by the following general formulas (I) and (II). These may be used alone or in combination with other polyfunctional monomers or monofunctional monomers. It is also desirable to use a system in which monomers of the general formulas (I) and (II) are used in combination. By using these monomers, a flexible and tough tenting film having good followability of the photopolymerizable layer to the substrate can be obtained. Is obtained.

[0019]

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[0020]

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The compound represented by the general formula (I) includes
For example, a diisocyanate compound such as hexamethylene diisocyanate, tolylene diisocyanate or 2,2,4-trimethylhexamethylene diisocyanate, and a compound having a hydroxyl group and a (meth) acryl group in one molecule (for example, 2-hydroxypropyl acrylate) , Oligopropylene glycol monomethacrylate and the like). These can be synthesized by a known method.

When n3, n4 and n5 of the compound represented by the general formula (II) are smaller than 3, the boiling point of the compound is lowered, the odor of the resist becomes strong, and the use becomes extremely difficult. On the other hand, if n3, n4 and n5 exceed 20, the concentration of the photoactive site per unit weight decreases, so that practical sensitivity cannot be obtained. The compound represented by the general formula (II) can be synthesized by a method of esterifying a product obtained by reacting propylene oxide and ethylene oxide with acrylic acid or methacrylic acid in the presence of a suitable acid catalyst. .

These monomers may be used alone or in combination of two or more. The amount used is selected from the range of 5 to 60% by weight. If it is less than 5% by weight, the sensitivity and film strength are not sufficient. If it exceeds 60% by weight, the photopolymerizable layer during storage when used for DFR is used. This is not preferable because the protrusion becomes significant. The amount of the photopolymerization initiator contained in the photopolymerizable composition of the present invention is 0.01 to 30% by weight, preferably 0.05 to 10% by weight. When the amount of the photopolymerization initiator exceeds 30% by weight, the active absorptivity of the photopolymerizable composition is increased, and when used as a photopolymerized laminate, the bottom of the photopolymerizable layer is insufficiently cured by polymerization. . If the amount of the photopolymerization initiator is less than 0.01% by weight, sufficient sensitivity cannot be obtained.

In order to improve the thermal stability and storage stability of the photopolymerizable composition of the present invention, it is preferable that the photopolymerizable composition contains a radical polymerization inhibitor. Examples of such a radical polymerization inhibitor include p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-cresol,
2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), nitrosophenylhydroxyamine aluminum salt, diphenylnitrosamine and the like.

The photopolymerizable composition of the present invention may contain coloring substances such as dyes and pigments. Examples of such coloring substances include fuchsin, phthalocyanine green, auramine base, chalcoxide green S, paramagenta, crystal violet, methyl orange, nile blue 2B, Victoria blue, malachite green, basic blue 20, diamond green, and the like. Can be

Further, a coloring dye which develops color upon irradiation with light may be contained in the photopolymerizable composition of the present invention. Examples of the color-forming dye include a combination of a leuco dye or a fluoran dye and a halogen compound. Examples of the leuco dye include tris (4-dimethylamino-2-methylphenyl) methane [leuco crystal violet], tris (4-dimethylamino-2-methylphenyl) methane [leucomalachite green], and the like. On the other hand, examples of the halogen compound include amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, diphenylmethyl bromide, benzal bromide, methylene bromide, tribromomethylphenylsulfone, carbon tetrabromide, and tris (2,3 Dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide,
1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane, hexachloroethane, triazine compounds, and the like.

Examples of the triazine compound include 2,4,6 tris (trichloromethyl) -s-triazine and 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine. Among such color-forming dyes, a combination of tribromomethylphenylsulfone and a leuco dye or a combination of a triazine compound and a leuco dye is useful.

Further, a small amount of a glycidyl ether compound may be added to the photopolymerizable resin composition of the present invention as a thermal coloring inhibitor. Specific examples of such a thermal coloring inhibitor include polypropylene glycol diglycidyl ether,
Glycerin diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, bisphenol A-PO2 mol addition diglycidyl ether and the like can be mentioned.

Further, the photopolymerizable composition of the present invention may contain additives such as a plasticizer, if necessary. Examples of such additives include phthalic esters such as diethyl phthalate. When a photopolymerizable resin laminate for DFR is used, a support layer for supporting the photopolymerizable layer is laminated on the photopolymerizable layer containing the photopolymerizable resin composition. The support layer is desirably a transparent layer that transmits active light. Examples of the support layer that transmits active light include a polyethylene terephthalate film, a polyvinyl alcohol film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyvinylidene chloride film, a vinylidene chloride copolymer film, and a polymethyl methacrylate copolymer film. , A polystyrene film, a polyacrylonitrile film, a styrene copolymer film, a polyamide film, a cellulose derivative film, and the like. Further, if necessary, these films can be stretched and used. The thinner the film, the more advantageous in terms of image forming properties and economy. However, a film having a thickness of 10 to 30 μm is generally required to maintain strength.

A protective layer is laminated on the surface opposite to the photopolymerizable layer laminated with the support layer, if necessary. It is an important characteristic of the protective layer that the protective layer has a sufficiently small adhesive force with the photopolymerizable layer and can be easily peeled off than the support layer. Examples of such a protective layer include a polyethylene film and a polypropylene film. Further, as the protective layer, a film having excellent releasability shown in JP-A-59-202457 can be used.

Although the thickness of the photopolymerizable layer varies depending on the application, it is 5 to 100 μm, preferably 5 to 90 μm for preparing a printed circuit board. The thinner the photopolymerizable layer, the higher the resolution. Further, as the photopolymerizable layer is thicker, the film strength is improved. The process of producing a printed circuit board using the photopolymerizable resin laminate can be performed by a known technique, but will be briefly described below.

If there is a protective layer, the protective layer is first peeled off, and the photopolymerizable layer is laminated on the metal surface of the substrate for a printed circuit board by heating and pressing using a laminator. The heating temperature at this time is generally 40 to 160 ° C. Next, if necessary, the support layer is peeled off, and image exposure is performed with actinic light through a mask film. Next, if there is a support film on the photopolymerizable layer, the support film is removed, if necessary, and then the unexposed portion of the photopolymerizable layer is developed and removed using an alkaline aqueous solution. As the alkaline aqueous solution, an aqueous solution of sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide or the like is used. These alkaline aqueous solutions are selected according to the characteristics of the photopolymerizable layer, and generally, a 0.5% to 3% aqueous sodium carbonate solution is used. Next, a metal image pattern is formed on the metal surface exposed by the development by performing either a known etching method or a plating method.
Thereafter, the cured resist image is peeled off with an aqueous alkaline solution which is generally stronger than the aqueous alkaline solution used for development. The alkaline aqueous solution for peeling is not particularly limited, but an aqueous solution of 1% to 5% of sodium hydroxide or potassium hydroxide is generally used. It is also possible to add a small amount of a water-soluble organic solvent to a developer or a stripper.

[0033]

【Example】

Reference Example 1 A compound having the composition shown in Table 1 (column of Reference Example 1 ) was uniformly dissolved. Next, this mixed solution was uniformly applied to a 25 μm-thick polyethylene terephthalate film using a bar coater, and dried in a drier at 95 ° C. for 4 minutes. At this time, the thickness of the photopolymerizable layer was 40 μm. A 35 μm polyethylene film was laminated on the surface of the photopolymerizable layer on which the polyethylene terephthalate film was not laminated to obtain a laminated film. On the other hand, the surface of the copper-clad laminate obtained by laminating the 35 μm rolled copper foil was subjected to wet baffle polishing (trade name: Scotch Bright # 600, manufactured by 3M Co., 2 stations),
While peeling off the polyethylene film of this laminated film, the photopolymerizable layer was formed on a hot roll laminator for 105 minutes.
Laminated at ℃.

The laminate was irradiated with an ultra-high pressure mercury lamp (HMW-201KB, manufactured by Oak Manufacturing Co., Ltd.) through a mask film to expose the photopolymerizable layer at 80 mJ / cm ² . Subsequently, after peeling off the polyethylene terephthalate support film, a 1% aqueous solution of sodium carbonate at 30 ° C. was sprayed for about 90 seconds, and the unexposed portions were dissolved and removed, whereby a good cured image was obtained.

The following evaluation was performed on the laminate using the photopolymerizable composition of the present invention. (1) Cold flow property test The laminate obtained in Reference Example 1 was cut into 2.5 cm squares, sandwiched between iron plates having a diameter of 10 cm, and heated at 40 ° C for 5 minutes.
A load of 00 kg was applied. The sample was taken out, and the width of protrusion of the photopolymerizable layer was measured. The following ranking was used for evaluation.

○: less than 300 μm, 23
Can be stored for 6 months without cold flow at ℃. Δ: 300 μm or more and less than 600 μm, can be stored under the same conditions without cold flow for 1 to 6 months. X: 600 μm or more and less than one month can be stored without cold flow. (2) Measurement of minimum development time While peeling off the polyethylene film of the dry film resist on the copper-clad laminate on which the 35 μm rolled copper foil was laminated, the photopolymerizable layer was heated at 105 ° C.
Was laminated. Subsequently, after the polyethylene terephthalate support film of the laminate was peeled off, it was heated at 30 ° C.
% Aqueous sodium carbonate solution was sprayed, the minimum time for dissolving the unexposed photopolymerizable layer was measured, and the time was defined as the minimum development time. Actual development was performed for 1.5 times the minimum development time. (3) Followability evaluation test Lamination-exposure-development-etching-resist removal was performed on a copper-clad laminate obtained by laminating a 70-μm rolled copper foil using a commercially available dry film resist, and the line width was 100, 110, 120. , 130, 140, 15
A linear groove of 0 μm was formed. The depth of the groove was about 10 μm.

Using the grooved substrate thus produced, the above laminate was laminated in the same manner as described above. An image pattern was obtained by exposure and development using a line pattern (line width: 125 μm) perpendicular to the groove of the substrate through a mask film through the laminate. In addition, 5
A cupric chloride solution at 0 ° C. was sprayed for 120 seconds to etch the copper in the area without the resist. Finally, at 50 ℃
The cured resist was removed by spraying a 90% aqueous solution of sodium hydroxide for about 90 seconds. On the copper line thus formed, the portions where the grooves were previously broken and not broken were counted, and the number was x. On the other hand, the number of portions that were disconnected due to etching was counted, the number was set as y, and the disconnection rate (%) was calculated by the following formula, and ranked according to the following method.

Disconnection rate (%) = 100 y / (x + y) ○; disconnection rate less than 30% Δ; disconnection rate 30% or more and less than 50% ×; disconnection rate 50% or more (4) Flexibility and film strength a copper-clad laminate having a through-hole of the test diameter 5 mm, ginseng
It was laminated on both sides by the method described in Example 1 and exposed and developed without using a pattern mask. Next, the cured film on one side was removed, a piercing rod was set on a jig of a tensile tester, and the center of the through-hole film was pressed at a rate of 10 mm / min with a load of 5 kg. As a result, the elongation of the cured film until the film was broken and the strength at that time were measured.

(Reference Example 2, Examples 1 to 3, Comparative Examples 1 and 2) A photopolymerizable resin laminate having the composition shown in Tables 1 and 2 was obtained in the same manner as in Reference Example 1, and a cold flow test was performed. , Compliance test, flexibility and film strength test. The results are shown in Tables 1 and 2. <Symbol explanation> P-1: Methyl ethyl ketone solution of a terpolymer of 70% by weight of methyl methacrylate, 23% by weight of methacrylic acid and 7% by weight of butyl acrylate (solid content: 32%, weight average molecular weight: 85,000) P-2: 70% by weight of methyl methacrylate, 23% by weight of methacrylic acid, 7% by weight of butyl acrylate in a ternary copolymer in methyl ethyl ketone (solid content: 24%, weight average molecular weight: 300,000) Methyl methacrylate solution of terpolymer of methyl methacrylate 47% by weight, methacrylic acid 23% by weight, and styrene 30% by weight (solid content 32%, weight average molecular weight 45,000) P-4: methyl methacrylate 47% by weight, 23% by weight of methacrylic acid, 30% by weight of styrene in a tertiary copolymer solution in methyl tyl ketone (solid content: 32%, weight average molecular weight: 85,000) M-1: Trimethylolpropane triacrylate M-2: Hexamethylene diisocyanate and oligopropylene glycol monomethacrylate (Nippon Oil & Fats Co., Ltd.)
M-3: Dimethacrylate of glycol in which ethylene oxide is further added to both ends of polypropylene glycol having an average of 8 mol of propylene oxide and Mol of ethylene glycol is further added to both ends of the product. M-4: Tetrapropylene glycol dimethacrylate M -5: Tetraethylene glycol diacrylate A-1: Benzophenone A-2: 4,4'-bis (dimethylamino) benzophenone A-3: 2- (o-chlorophenyl) -4,5 diphenylimidazolyl dimer B- 1: Malachite green B-2: Leuco crystal violet B-3: Tribromomethylphenyl sulfone

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

EFFECT OF THE INVENTION D using the photopolymerizable resin composition of the present invention
FR is particularly low in cold flow during storage, has good follow-up properties during lamination on a substrate, and exhibits excellent flexibility and cured film strength after exposure.
It is useful as a DFR for preparing an alkali development type circuit board.

Continuation of front page (56) References JP-A-62-208042 (JP, A) JP-A-63-184744 (JP, A) JP-A-62-208044 (JP, A) JP-A-5-11446 (JP) JP-A-3-250006 (JP, A) JP-A-56-19752 (JP, A) JP-A-5-36581 (JP, A) JP-A-4-39653 (JP, A) 64-55550 (JP, A) JP-A-7-325398 (JP, A) JP-A-8-95245 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 7/033 G03F 7/027 502

Claims (2)

(57) [Claims] (1) a binder resin comprising a linear copolymer A having (a) a carboxyl group content of 100 to 600 as an acid equivalent and a weight average molecular weight of 100,000 to 500,000;
20-90% by weight, (b) represented by the following general formula (I)
And a photopolymerizable unsaturated compound represented by general formula (II):
5-60% by weight of a photopolymerizable unsaturated compound
(C) A photopolymerizable composition comprising a photopolymerization initiator and 0.01 to 30% by weight. Embedded image Embedded image 2. (a) a linear copolymer A having a carboxyl group content of 100 to 600 in acid equivalent and a weight average molecular weight of 100,000 to 500,000, and a carboxyl group content of acid equivalent A linear copolymer B having a vinyl compound having a phenyl group having a weight average molecular weight of 30,000 to 90,000 and having a weight average molecular weight of 30,000 to 90,000 is one of the copolymerization components.
Binder resin mixed so that B becomes 90/10 to 10/90, 20 to 90% by weight, (b) the following general formula
Photopolymerizable unsaturated compound represented by (I) and general
A photopolymerizable unsaturated compound represented by the formula (II),
A photopolymerizable composition comprising: (c) a photopolymerization initiator, and 0.01 to 30% by weight. Embedded image Embedded image