JP2540910B2 - Photopolymerizable composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel photopolymerizable composition, and
The present invention relates to a photopolymerizable composition having improved cured film strength.

(Prior Art) In the production of printed wiring boards, dry film type photoresists are liquid type resists because they can easily form a photoresist layer with a uniform film thickness and can be used as a through-hole etching resist in the so-called tenting method. Is better than A hole called a through hole is pre-drilled, a metal layer such as copper is formed inside the hole, and a dry film is laminated on both sides of a double-sided board having conductor layers on both sides. Pattern exposure is performed so that a slightly larger resist film is formed. After development, etching is performed to remove unnecessary metal layers. At this time, the metal in the through hole is protected by the resist film provided on the upper portion of the through hole, so that both surfaces of the formed printed circuit board can be electrically conducted. The dry film resist used for such a purpose is required to stably adhere to the substrate under the conditions where development and etching are performed, and that the etching liquid does not penetrate into the through hole. Have not always been satisfactory. Generally, increasing the exposure dose during pattern formation improves the tent film strength. However, as the exposure dose increases, the resolution decreases, making it difficult to form high-density patterns. Also, the time required for exposure increases and productivity decreases. I will end up.

A method has been proposed in which the adhesion to the substrate at the land around the through hole is increased to improve the reliability of the tenting (Japanese Patent Laid-Open Nos. 59-113432, 60-12543 and 59-16).
6944, Japanese Patent Laid-Open No. 60-19135), these processes often include various substances that promote adhesion in the photosensitive layer, which often cause poor development, defects in the post-process such as resist removal, etc. May be given.

A method of using a halogen-based additive in order to increase the strength of the cured film after exposure of the photosensitive layer has also been proposed (Japanese Patent Laid-Open No. Sho 60-62).
-15972, JP-A-57-60372, JP-A-59-78339
No.), this method is also useful for enhancing sensitivity and color development. However, in the case of a photoresist having a relatively high sensitivity, the deterioration of storage stability becomes a problem. In particular, when the photosensitive layer is in contact with the copper surface, the dark reaction in the unexposed area tends to be remarkable.

(Problems to be Solved by the Invention) The present invention provides a photopolymerizable composition that solves the above-mentioned problems of the prior art and provides high cured film strength.

(Means for Solving the Problems) The present invention provides (1) an addition-polymerizable compound having a boiling point of 100 ° C. or higher at normal pressure (2) a photoinitiator (3) a diphenylmethane compound represented by the following formula [I] (In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀ are each independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 12 carbon atoms. , An alkoxy group having 1 to 12 carbon atoms, an alkoxycarbonyl group having 1 to 12 carbon atoms, an aryl group, an aryloxy group, an acyl group having 1 to 12 carbon atoms, a formyl group, a hydroxyl group or a carboxyl group, and X is hydrogen. Atom, halogen atom, alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, acyl group having 1 to 12 carbon atoms, carboxyl group, hydroxyl group, amino group, alkylamino group having 1 to 12 carbon atoms , Formyl group, alkoxycarbonyl group having 1 to 12 carbon atoms, alkylcarbonyloxy group having 1 to 12 carbon atoms, aryloxycarbonyl group, arylcarbonyl group, or arylcarbonyloxy group) To the composition Related.

The addition-polymerizable compound contained in the photopolymerizable composition according to the present invention has a boiling point of 100 ° C. or higher at normal pressure. When the boiling point is lower than 100 ° C under normal pressure, the addition-polymerizable compound is volatilized and volatilized when the solvent contained in the system is removed by drying or irradiated with an actinic ray. This is because it is not preferable. The addition-polymerizable compound is preferably soluble in the organic solvent used in order to form a uniform composition with the photoinitiator and the like.

Organic solvents include, for example, acetone, methyl ethyl ketone,
Toluene, chloroform, methanol, ethanol, 1,
1,1-trichloroethane or the like is used.

The addition-polymerizable compound having a boiling point of 100 ° C. or higher at normal pressure is obtained by condensing a polyhydric alcohol and an α, β-unsaturated carboxylic acid, for example, diethylene glycol di (meth) acrylate (diacrylate or dimethacrylate). Meaning of acrylate, same below), triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,3-propanediol Di (meth) acrylate, 1,3-butanediol (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, 2,2-bis (4 -Acry Roxydiethoxyphenyl) propane, 2,2-bis (4-methacryloxypentaethoxyphenyl) propane, etc. obtained by adding α, β-unsaturated carboxylic acid to a glycidyl group-containing compound,
For example, Shin-Nakamura Chemical Co., Ltd. trade name BPE-500 (mixture of 2,2-bis (4-methacryloxypolyethoxyphenyl) propane), trimethylolpropane triglycidyl ether tri (meth) acrylate, bisphenol A dicryl. Sidyl ether di (meth) acrylate, trade name MECHPP (γ-chloro-β-vidroxypropyl-β-methacryloyloxyethyl-α-phthalate) manufactured by Osaka Organic Chemical Co., Ltd., unsaturated amides such as methylenebisacrylamide, ethylene Bisacrylamide, 1,6-hexamethylenebisacrylamide, etc., vinyl ester such as divinyl succinate, divinyl adipate, divinyl phthalate, divinyl terephthalate, divinyl benzene-1,3-disulfonate, urethane acrylate such as
2,2,4-trimethylhexamethylene diisocyanate,
Examples include cyclohexanedimethanol and β-hydroxyacrylate adducts.

This addition-polymerizable compound is used alone or in combination of two or more.

As the photoinitiator used in the present invention, conventionally known photoinitiators can be used. For example, SP Purpose (SPPap
pas) Chapter 1 of "UV Curing: Science and Technology" (UV Curing: Science and Technology) and SP Purppas (SPPappas) Chapter "UV Curing: Science and Technology Vcl.II" (UV
Various compounds described in Chapter 1 of Curing: Science and Technology Vol.II) can be used. For example, benzylphenone, thioxanthone, chlorothioxanthone, alkyl-substituted thioxanthones, benzyl,
They are 4,4'-dimethoxybenzyl, 9,10-phenanthrenequinone, 9,10-anthraquinone, azo compounds and acylphosphines. A binary photoinitiator in which a reducing agent such as an amine is combined with benzophenones, thioxanthones and 3-ketocoumarins can also be preferably used.
For example, benzophenone and triethanolamine, benzophenone and Michler's ketone, benzophenone and 4,
4'-bis (diethylamino) benzophenone, 2,4-diethylthioxanthone and isopentyl 4-dimethylaminobenzoate, 2,4-diethylthioxanthone and ethyl 4-dimethylaminobenzoate, 3,3'-carbonylbis (7-
Diethylamino) coumarin and N, N-diethylaniline, 3
There are combinations such as -benzoyl-7-methoxycoumarin and N-phenylglycine, and 4'-cyanobenzoyl-5,7-dimethoxycoumarin and N'-phenylglycine.
As the photo-reducing dye, rose bengal, erythrosine, eosin, riboflavin, thionine and the like can be used alone or in combination with various reducing agents. Two or more photoinitiators may be used.

In the present invention, the diphenylmethane compound represented by the above formula [I] is used, and examples thereof include bromodiphenylmethane, chlorodiphenylmethane, 1,1-diphenylethane, 1,1-diphenylpropane and 1,1-diphenyl. -N-
Butane, benzhydrol, methoxydiphenylmethane, diphenylacetic acid, 3,3-diphenylpropionic acid, 4,4
-Diphenyl butyric acid, benzhydrylamine, di (p-chloro) phenylacetic acid, 2-p-chlorophenyl-2-phenylacetic acid, diphenylacetic acid methyl ester, diphenylacetic acid ethyl ester, di (p-methyl) phenylacetic acid, 2
Examples thereof include -o-methoxyphenyl-2-phenylacetic acid, 2,2-diphenylacetaldehyde, 3,3-diphenylbutyraldehyde and the like.

These diphenylmethane compounds may be used alone or in combination of two or more.

In the present invention, 0.01 to 20 parts by weight of a photoinitiator and 100 parts by weight of an addition-polymerizable compound having a boiling point of 100 ° C. or more at the above normal pressure and a diphenylmethane compound represented by the above formula [I] are added. It is preferably used in the range of 0.01 to 20 parts by weight.

The photopolymerizable composition of the present invention may optionally contain one or more high molecular weight organic polymers. The high molecular weight organic polymer is thermoplastic and has a molecular weight of 10,000 to 700,0
Those having 00 are preferred. For example, the following is used.

(A) Epolyester Produced from polyhydric alcohols such as diethylene glycol, triethylene glycol, tetraethylene glycol, trimethylolpropane, neopentyl glycol and the like and polyvalent carboxylic acids such as terephthalic acid, isophthalic acid, sebacic acid, adipic acid and the like. Made copolyester.

(B) Vinyl polymer Methacrylic acid, acrylic acid, methacrylic acid or alkyl ester of acrylic acid, such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth)
Acrylate, β-vidroxyethyl (meth) acrylate, styrene, vinyltoluene, vinyl chloride,
Homopolymers or copolymers of vinyl monomers such as vinyl butyral.

(C) polyformaldehyde (D) polyurethane (E) polycarbonate (F) nylon or polyamide (G) cellulose ester such as methyl cellulose,
By adding a high molecular weight organic polymer to the ethylcellulose photopolymerizable composition, properties such as adhesion to a substrate, chemical resistance and film property can be improved. This high molecular weight organic polymer is in the range of 80% by weight or less based on the total weight of the high molecular weight organic polymer and the addition polymerizable compound. 80% by weight
If the amount exceeds the above range, photocuring does not proceed sufficiently, which is not preferable.

The photopolymerizable composition of the present invention may also contain coloring materials such as dyes and pigments, if necessary. Known coloring substances are used, for example, fuscine, crystal violet, methyl orange, Nile blue 2B, Victoria visual blue, malachite green, night green.
B, Spiron blue, etc.

The photopolymerizable composition according to the present invention may contain a radical polymerization inhibitor or a radical polymerization inhibitor in order to enhance stability during storage. Examples of such substances include p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, phenothiazine, pyridine, nitrobenzene, and arylphosphite.

The photopolymerizable composition according to the present invention may contain other additives known to be used in the photopolymerizable composition, for example, additives such as a plasticizer and an adhesion promoter.

The photopolymerizable composition of the present invention can be applied to a support and exposed to actinic rays to produce a printing plate, or can be used as a photoresist for forming a circuit by etching or plating. The actinic radiation source used is 250 nm to 550
Those that generate actinic radiation with a wavelength of nm are used.

Such light sources include carbon arc lamps, mercury lamps,
There are xenon arc lamps, argon glow lamps, argon ion lasers, etc. As the support, an organic polymer film such as polyethylene film, polypropylene film, or polyethylene terephthalate film, a steel plate, an aluminum plate, a metal plate such as an iron plate, an insulating plate (a glass epoxy base material, a paper epoxy base material) having a steel foil attached to the surface thereof. Materials, paper phenol base materials, etc.) are used.

(Function) In the present invention, when the above component (2) polymerizes the component (1) by the action of light, the component (3) adjusts the degree of polymerization to relieve the stress due to shrinkage accompanying polymerization. , It is presumed that the strength of the obtained cured film is increased.

(Example) An example of the present invention will be described. Here, parts and% indicate parts by weight and% by weight, respectively.

Example 1 Preparation of Photopolymerizable Composition of acrylic polymer (methacrylic acid / methyl methacrylate / butyl methacrylate / 2-ethylhexyl acrylate = 23/51/6/20 parts by weight copolymer, weight average molecular weight about 90,000) 40% ethyl cerolylbu solution 120 parts BPE-500 (Shin-Nakamura Chemical Co., Ltd. trade name, 2,2-bis (4-
Mixture of methacryloxypolyethoxyphenyl) propane) 30 parts MECHPP (trade name, γ-chloro-β, manufactured by Osaka Organic Chemical Co., Ltd.)
-Bidroxypropyl-β'-methacryloyloxyethyl-o-phthalate) 10 parts Tetraethylene glycol dimethacrylate 3 parts Antage W-500 (Kawaguchi Chemical Co., 2,2'-methylenebis (4-ethyl-6-t-) Butylphenol)) 0.3
Parts N- (p-chlorophenyl) -N-ethylglycine 4.0
Part 3,3'-Carbonylbis (7-diethylamino) coumarin 0.2 part Methyl ethyl ketone 20 parts To the above photopolymerizable compositions, the compounds shown in Table 1 were added as examples, and these compounds were not added as comparative examples. The thing was prepared as a coating liquid.

Each coating solution was applied onto a 2.5 μm thick polyethylene terephthalate film (manufactured by Toray Industries, Inc., trade name “Lumilar”) using a bar coater and dried in a hot air convection dryer at 100 ° C. for about 3 minutes. A photopolymerizable element was obtained. The thickness of the dried photopolymerizable composition layer was 40 μm.

Next, using a laminator that pressurizes and heats with a rubber roll to laminate, make sure that the photopolymerizable composition layer and the copper surface are in contact with both surfaces of the glass epoxy double-sided copper clad laminate having a clean surface through hole with a diameter of 3.2 mm. The temperature of the rubber roll is 160 ℃
The photopolymerizable element was laminated as.

Both surfaces of the stacked samples were irradiated with a 3 kW ultra-high pressure mercury lamp (HMW201B, manufactured by Oak Co.). The light irradiation amount is Stepbuta Plate (manufactured by Dainippon Screen Co., Ltd., trademark gray scale, optical density step 0.13, minimum optical density 0.0
5, a negative film having a maximum optical density of 3.05 and 21 steps was closely contacted, exposed, and irradiated with the energy that remained when the number of steps was 8 when developed.

Then remove the polyethylene terephthalate film
Spray development was carried out for 60 seconds with a 1% Na ₂ CO ₃ aqueous solution at 30 ° C., and air-dried at room temperature for 1 hour in the dark. Rheometer (FUDOH,
Using a NRM-2010J-CW), a steel rod with a diameter of 2.0 mm was introduced to read the force (gf) when the film was vulcanized, and the strength was measured. The results are shown in Table 1.

It is shown that high cured film strength is obtained in the examples.

(Effects of the Invention) The photopolymerizable composition according to the present invention is a photopolymerizable composition that gives a high cured film strength, and is useful for forming a dry film resist having excellent tenting property in the production of a printed circuit board, for example. is there.

Claims (2)

(57) [Claims] 1. An addition-polymerizable compound having a boiling point of 100 ° C. or higher at normal pressure, (2) a photoinitiator, and (3) a diphenylmethane compound represented by the following formula [I]. (Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀
Are each independently a hydrogen atom, a halogen atom, or a carbon number of 1 to
A 12 alkyl group, a C1-12 alkoxy group, a C1-12 alkoxycarbonyl group, an aryl group, an aryloxy group, a C1-12 acyl group, a formyl group, a hydroxyl group or a carboxyl group. , X is a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an acyl group having 1 to 12 carbon atoms, a carboxyl group, a hydroxyl group, an amino group, and 1 to 12 carbon atoms.
Is an alkylamino group, a formyl group, an alkoxycarbonyl group having 1 to 12 carbon atoms, an alkylcarbonyloxy group having 1 to 12 carbon atoms, an aryloxycarbonyl group, an arylcarbonyl group or an arylcarbonyloxy group). Photopolymerizable composition. 2. The photopolymerization according to claim 1, which contains a high molecular weight organic polymer, and the high molecular weight organic polymer is 80% by weight or less based on the total weight of the high molecular weight organic polymer and the addition polymerizable compound. Sex composition.