JPH01242609A - Ultraviolet curing resin composition - Google Patents

Abstract

PURPOSE:To attempt to improve ultraviolet curability, hardness, resistance to etching soln. and removability by peeling with an aq. alkali soln., by blending a specified carboxyepoxy acrylate, a half ester, a polymerizble monomer and a polymn. initiator. CONSTITUTION:A carboxyepoxy acrylate (a) is obtd. by reacting an epoxy acrylate, obtd. by reacting an epoxy resin (oligomer) obtd. by reciting bisphenol A with epichlorohydrin with (meth)acrylic acid and there by opening the epoxy ring, with a polyacid anhydride (e.g., maleic anhydride). 0.1-10wt.% polymn. initiator (d) (e.g., benzoin) is added to a compsn. consisting of 30-60wt.% component (a), 20-60wt.% half ester (b) of a polyacid anhydride with hydroxy (meth) acrylate and 10-40wt.% polymerizable monomer (c) [e.g., methyl (meth)acrylate].

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an ultraviolet curable resin composition. In particular, ultraviolet curable resin compositions that have excellent curability, film hardness, and etching liquid resistance, as well as excellent peeling and removability with aqueous alkaline solutions, are suitable for use as etching resist inks for manufacturing printed wiring boards. It is.

[Conventional Technology 1] Recent advances in the electronics industry require miniaturization of materials and high reliability including long life. For this reason, copper-clad laminates are no exception as components in fields where single-circuit wiring is increasingly required to have thinner pattern lines and higher density. After printing the etching resist ink in the desired pattern, drying or curing with ultraviolet rays, then immersing it in an etching solution,
A pattern is formed by dissolving and removing unnecessary portions of the copper foil, and then the resist skin nQ is peeled off using an alkaline aqueous solution or a solvent to form a copper circuit corresponding to the resist pattern.

In the above, methods for printing the etching resist ink generally include screen printing or offset printing, and etching solutions include ferric chloride aqueous solution and cupric chloride aqueous solution.

A mixed aqueous solution of hydrogen peroxide and i-acid, an aqueous solution of per&i-acid, etc. are often used.

Conventionally, when a solvent-based etching resist ink is used to manufacture printed circuit boards, it is printed in a pattern on the copper foil of a copper-clad laminate, then heated to form a resist pattern film, and then the unnecessary etching resist ink is printed on the copper foil of the copper-clad laminate. A copper circuit is formed by removing the copper foil in the area with an etching solution and peeling off the resist film with an alkaline aqueous solution, and then print wiring 4Ji! Manufactures handling.

However, such solvent-based etching resist inks tend to cause problems due to clogging of screen printing plates, require considerable time and large amounts of thermal energy for heating and drying, and are also susceptible to problems such as surface contamination and the risk of ignition. contains problems.

Various resist inks have been proposed in order to improve the drawbacks seen in solvent-based etching resist inks such as L. In other words, if you use UV-curable etching resist ink, use it! A predetermined pattern is printed on a $+i paper sheet treated as a single layer, and then UV rays are irradiated without heating and drying to form a resist pattern film.Then, the copper foil is removed with an etching solution to create a resist pattern. A bullet wiring board is obtained by forming a copper circuit corresponding to the above, and peeling and removing the resist film using alkaline water.

As described in JP-A No. 51-2503, the ultraviolet curable etching resist ink includes a polyester binder, hydroxyalkyl acrylate-1, a photopolymerizable monomer, a carboxylic acid, and a photopolymerization initiator. There is inking with a composition containing the agent. However, in the case of this composition, the time required for alkaline removal is 5 to 10 times longer than in the case of conventional solvent-based etching resist inks. As m increases, the hardness of the coating decreases.
However, there were some practical difficulties.

Further, JP-A-56-8417 discloses a binder polymer having a carboxyl group or a carboxylic acid anhydride, a photoinsectable compound, and a photosensitizer. A composition in which the UV-cured film is soluble in an aqueous alkaline solution is shown as r+r+. However, when etching is performed using this composition, it is extremely difficult to dispose of the waste liquid, and the dissolved hardened
There was a problem that it could not be disposed of unless the first quarter was collected.

Furthermore, in JP-A No. 57-13444, polyester, a hydroxyalkyl acrylate (or methacrylate-1-) half-ester of polybasic rvI (or its anhydride), a vinyl monomer having a bimanual unsaturated bond, and an optical A photosensitive resin composition containing a polymerization initiator is disclosed. but.

In the case of this composition, the hardness of the coating film is insufficient (the coating film softens in the etching solution, and damage to the resist surface due to contact with the transfer roll during the process is expected, which is also impractical). The problem remained.

[Problems to be Solved by the Invention] As mentioned above, conventionally known ultraviolet curable resin compositions have one important physical property, such as the ultraviolet curability of the resist film, hardness, resistance to etching liquid, or its peeling and removability. However, the object of the present invention is to provide an excellent ultraviolet curable resin composition that eliminates all of these conventional problems.

[Means for Solving the Problems] In order to solve the above-mentioned technical problems, the inventors of the present invention discovered that the following composition was effective and completed the present invention.

That is, the present invention provides (i) carboxyepoxy acrylate obtained by reacting a polybasic anhydride with an epoxy acrylate, (11) a half-esterified product of a polybasic anhydride with a hydroxyalkyl (meth)acrylate, (
A resin composition comprising a photopolymerizable monomer (iii) and a photopolymerization initiator (iv), characterized in that the resin composition is cured by ultraviolet irradiation and the cured film has excellent peelability and removability with an aqueous alkaline solution. It is an ultraviolet curable resin composition.

[Detailed Description of the Invention] The first component (1) of the present invention will now be described. Epoxy acrylate is made by reacting (meth)acrylic acid with an epoxy resin (oligomer) obtained by reacting epichlorohydrin with bisphenol 8, and producing epoxy I.
Component (i) is obtained by opening Q to form an acrylic ester.If this is further treated with a polysalt 15 acid anhydride to half-esterify the hydroxyl group of fL separation of the epoxy acrylate, component (i) can be obtained.

In addition to the above-mentioned epoxy resins, the epoxy resins include Ebibis type liquid epoxy, such as Epicoat 828, BisF type,
For example Evicron 830, liquid epoxy, timer acid modified epoxy, for example Epicort 872.871. Screw A
Quib side chain epoxy, e.g. electrified EP-4000,
Polyglycol type diglycidyl ether (DER-73
6), and the polybasic acid anhydrides referred to in (1) include phthalic anhydride, hegisahydrophthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, succinic anhydride, and anhydride. Examples include maleic acid.

Next, the second component (ii) of the present invention will be explained. Here, the polybasic acid anhydride is the same as the polybasic acid anhydride in (i).

Hydroxyalkyl (meth)acrylates include 2-hydroxyethyl acrylate and methacrylate [both acrylate and methacrylate are referred to as (meth)acrylate. ], ]2-hydroxypropyl meta)
These are acrylates, etc., and those in which a dibasic acid is converted into a monostyrene by means of these alcohol groups are called old esters, and are the compound of (11) of the second component.

Furthermore, the third component of the present invention (iii photopolymerizable photopolymerizable-
Tuma, (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, 1so-propyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate Acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, glycidyl (meth)acrylate , 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acryloyl phosphate, tetrahydroxyfurfururine glycol mono(meth)acrylate, ethylcarpitol (meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate,! ．． 4-butanediol di(meth)
Acrylate, 1,6-hexanethiol di(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, 0-hydroxypivalic acid ester neobentyl glycol di(meth)acrylate, N- Examples include vinylpyrrolidone.

Such photopolymerizable monomers iii1 can be used alone or in combination of two or more in any proportion.

Furthermore, as the photopolymerization initiator fivl used in the present invention, known photopolymerization initiators can be used, but
It is desirable to use ultraviolet light that has good storage stability. Examples of these are benzoin, benzyl, penzoin medyl ether, benzoin ethyl ether, benzoin-
n-propyl chloride, benzoin-iso-propyl ether, benzoin-n-butyl ether, benzoin-iso-butyl ether, benzophenone, diacetyl, acetophenone, anthraquinone, 2-ethylanthraquinone, 2-chloroanthraquinone, benzyl dimethyl ketal 2thioxanthone, 2-chlorodioxanthone, 2-methylthioxanthone, 1.4-iso-
Examples include propylphenyl-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and these are used alone or in combination.

In addition, n-butylamine is added as necessary.

-Butylamine, triethylamine, dietylaminoethyl methacrylate, Michler's ketone, sodium diethylthiophosphate, etc. can be used in combination as effective sensitizers.

The proportions of these components to be used can be varied over a wide range; for example, (i) component 30 to 60 wL%, preferably 35 to 45 wL%, (ii) component 20 to 60 wL%.
t%, preferably 25 to 35 wt% (iii) 10 to 40 wt% of one component, preferably 25 to 35 wt%.

Furthermore, if a photopolymerization initiator is mixed with this resin composition, the ultraviolet curable resin composition of the present application will be obtained.
．． It is preferably used in a range of 1 to lowt%.

When the ultraviolet curable resin composition of the present invention is used as an etching resist ink, in order to further improve printing suitability (1) image resolution, etc., (1) add anti-foaming to an extent that does not impair the characteristics of the resin composition of the present invention. Further substances such as additives, viscosity modifiers, thermal polymerization inhibitors 1 and colorants can be added.

As the anti-iB agent, anti-foaming agents commonly used in screen printing inks, such as various silicone compounds, can be used as appropriate. The amount of these used is usually in the range of 0.005 to 1% by weight. Specific examples include oil-type defoaming agents (KF96, K867) manufactured by Shin-Etsu Silicone, and silicone-based defoaming agents specially prepared for screen printing (for example, manufactured by Mura Nikleen).

In addition, as a viscosity modifier, for example, a silica-based compound can be used to impart thixotropy to the ink.
Usually, an amount of 0.3 to 1% by weight of IO is used. For example, Aerosil #200 manufactured by Nippon Aerosil is available.

Examples of thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, 2.6-tert-butyl-p-cresol, 2.2-methylene bi2. (4-ethyl-6-t
tert-butylphenol), tert-butylcatechol, pyrogallol, β-naphthylamine, p-torquinone, triphenylphosphite, etc. can be used.

Further, as the coloring agent, dyes and various organic and inorganic pigments can be used as appropriate.

The ultraviolet rays used for curing the ultraviolet curable resin composition according to the present invention are effective at wavelengths of 150 to 500 nm, particularly those in the wavelength range of 300 to 450 nm, and the light sources used include low pressure mercury lamps, High-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, metal halide lamps, etc. are desirable.

Further, the ultraviolet curable resin composition as an etching resist ink according to the present invention may be prepared by uniformly filling the above-mentioned components constituting the composition using a triple roll or the like.

In addition, when mixing each substance, use a low boiling point organic solvent such as acetone, methyl ethyl ketone, methylene chloride, ethylene dichloride, etc. and a solvent that dissolves the resin composition to form a uniform solution, and then It is also possible to prepare the resin composition of the present invention by removing the used solvent by an appropriate method such as heating or reduced pressure.

[Example] The present invention will be explained in more detail with reference to Examples below.

1497 parts of carboxyevo diacrylate Al i bisphenol type epoxy resin (Epicote 828),
576 parts of acrylic acid, tris(dimethylaminomethyl)
10.4 parts of phenol, 1.28 parts of methylhydroquinone
2 parts at 120-130℃ while blowing air.
After reacting for ~3 hours, an epoxy acrylate with an acid value of 7 was obtained. Then, 784 parts of maleic anhydride was added to give 120 parts.
When the reaction is continued at ℃ for 2 hours, the infrared absorption spectrum shows 17
The acid anhydride peaks at 75 cm-' and 1840 cm-' disappeared. As a result, carboxyepoxy acrylate having an acid value of 136 was obtained.

348 parts of 2-hydroxy engineered acrylate, 456 parts of tetrahydrophthalic anhydride, 0.80 parts of hydroquinone 7-methyl ether, and 1.60 parts of tris(dimethylaminomethyl)phenol were charged and heated at 110 to 130°C while blowing air. By reacting for 3 hours, tetrahydroxyphthalic acid monoacryloyl hydroxyethyl ester having an acid value of 210 was obtained.

40 parts of the above synthetic carboxyepoxy acrylate, 30 parts of tetrahydroxyfucuric acid monoacryloyl hydroxyethyl ester, 20 parts of tripropylene glycol diacrylate, 10 parts of trimethylolpropane triacrylate, and 2-hydroxy-2 as a photocuring agent.
-Methyl-1-phenyl-propan-1-one (4 parts) was blended to obtain a resin composition for etching resist ink.

The above resin composition for etching resist ink was applied to the surface of a copper plate to a thickness of 15 μm using a bar coater, and then coated at 2K.
W (80 W/cm) high pressure mercury lamp was irradiated for 3 seconds. The resulting resist film has a pencil hardness of 3H1 and an adhesion of 1.
It was 00/loo.

The above copper plate was etched with 40% ferric chloride at 40° C. for 3 minutes, but no peeling of the resist film occurred. Thereafter, the copper plate was treated with a 3% aqueous sodium hydroxide solution at 40°C, and the ultraviolet cured film was completely peeled off in 10 seconds.

"Effects of the Invention" The resin composition of the present invention is rapidly cured by ultraviolet rays, has a highly hard film obtained thereby, has high durability against etching solutions such as ferric chloride or cupric chloride, and The object of the present invention is to provide an ultraviolet curable resin composition that can be quickly peeled off and removed using an alkaline aqueous solution and can be used as an excellent photoresist.

Patent applicant: Showa Kobunshi Co., Ltd. Agent: Patent Attorney Sei Kikuchi

Claims (1)

[Claims] (1) (i) Carboxyepoxy acrylate obtained by reacting polybasic acid anhydride and epoxy acrylate, (ii) Half-esterified product of polybasic acid anhydride with hydroxyalkyl (meth)acrylate, (iii) Light An ultraviolet curable resin composition comprising a polymerizable monomer (iv) and a photopolymerization initiator.