JPS5989316A - Solder resist ink composition curable by ultraviolet rays - Google Patents

Abstract

PURPOSE:The titled composition having improved curing properties of thick film, soldering resistance, heat resistance, water-vapor resistance, solvent resistance, and electrical insulating properites, containing an aromatic compound having plural (meth)acryloyl, a (meth)acryloyl aromatic derivative and a photosensitizer. CONSTITUTION:(A) 20-80wt% unsaturated compound having two or more (meth)acryloyl groups obtained by reacting an epoxy compound of a polyhydric phenol or polyether compound with (meth)acrylic acid is blended with (B) 5- 70wt% monomer (e.g., p-butyl-phenoxyethyl acrylate, etc.) shown by the formula I [X is H, 1-12C alkyl, or group shown by the formula II (R is H, or CH3); Y is group shown by the formula III, or formula IV (n is integer of 0-10); Z is H, or CH3] and (C) 0.5-15wt% photosensitizer (e.g., benzyl dimethylketal, etc.) as main components, to give the desired composition. If, necessary, the composition is blended with another monomer and an additive.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a permanent protective film for printed circuit boards that is cured by ultraviolet rays and has excellent thick film curing properties, plating resistance, heat resistance, moisture resistance, solvent resistance, chemical resistance, and electrical resistance. The present invention relates to a solder resist ink composition with excellent insulation properties.

In recent years, ultraviolet curable compositions have been widely used for reasons such as resource saving, energy saving, improved workability, and improved productivity. For similar reasons, in the field of printed circuit board processing, various inks such as pattern forming inks, solder resist inks, and marking inks are shifting from conventional thermosetting compositions to ultraviolet curable compositions. Among these, conventional thermosetting compositions for solder resist inks require long heating times, which poses many problems such as workability and deformation of the base material, so we quickly transitioned to UV-curable compositions. did. However, the current applications of this ultraviolet curable composition are limited to so-called consumer substrates used in radios, televisions, etc., and industrial substrates such as computers and control equipment. It has not yet been applied to the field. This is because solder resist inks used for industrial boards have thick film hardening properties, plating resistance, high electrical insulation properties, and under humid conditions, which are not required of solder resist inks for consumer boards. This is because high performance such as soldering heat resistance is required, and current solder resist inks for consumer boards do not reach the required performance level.

In other words, the thickness of the conductor pattern is different between industrial and consumer boards, and while the thickness of the conductor pattern for consumer boards is 35μ, the thickness of the conductor pattern for industrial boards is 35 μm, whereas the thickness of the conductor pattern for industrial boards is 35μ. The thickness including the plating is over 100μ. Therefore, the film thickness of the printed ink is 10 to 20 μm on the conductor in the case of a consumer board, and 40 μm to 40 μm at the edge of the conductor.
50μ, and in the case of industrial boards, the conductor is 10 to 20μ,
At the edge portion of the conductor, it becomes approximately ioo~120μ.

As described above, the solder resist ink for aviation substrates is required to have stable curability for thick films.

However, in the current situation, in order to fully cure the thick film part, the thin film part on the tin body hardens slowly, making it easy to cause poor adhesion and cracking due to thermal shock such as heat shock, and also to cure the thin film part. On the other hand, if proper curing conditions are used, poor curing of the thick film portions will cause problems with electrical insulation, plating resistance, heat resistance under humidification, etc., which does not fully satisfy the required performance of solder resist ink for industrial boards. Things have not been developed yet. As a result of intensive studies to solve the above problems, the inventors of the present invention have discovered an ultraviolet curing solder resist ink that has excellent thick film curing properties, plating resistance, heat resistance, moisture resistance, solvent resistance, and electrical insulation properties. They discovered a composition and completed the present invention.

That is, the ultraviolet curable solder resist ink composition of the present invention has (meth)acryloyl groups obtained by reacting an epoxy compound of polyhydric phenol or a polyetherified product of polyhydric phenol with (meth)acrylic acid. (B) a monomer represented by the general formula (I) or +0H260→71. (n represents an integer of O to 10), Z represents a hydrogen atom or a methyl group, and ( 0) An ultraviolet curing solder resist ink composition characterized by containing a photosensitizer as a main component.

Here, (meth)acrylic acid and (meth)acryloyl group include acrylic acid, methacrylic acid, acryloyl group, and methacryloyl group.

As the unsaturated compound (A) used in the present invention ('!,
, for example, an unsaturated compound obtained by adding (meth)acrylic acid to an epoxy compound obtained by reacting a polyhydric phenol such as bispheno-AzA, bisphenol F, or novolac with epichlorohydrin, or an unsaturated compound obtained by adding (meth)acrylic acid to the above polyhydric phenol. Ethylene oxide,
Examples include unsaturated compounds obtained by subjecting (meth)acrylic acid to an esterification reaction with a polyetherified polyhydric phenol obtained by adding propylene oxide, butylene oxide, ε-caprolactone, or the like. These unsaturated compounds (A) can be used alone or in combination of two or more in any proportion. (B) As the monomer,
Phenoxypolyethoxyethyl (meth)acrylates represented by phenoxyethyl (meth)acrylate, phenoxyjethoxyethyl (meth)acrylate, phenoxyisoprobyl (meth)acrylate, phenoxydiisopropoxyisopropyl (meth)acrylate p-ethylphenoxyethyl (meth)acrylate, p-butylphenoxyjethoxyethyl (meth)acrylate, p-nonylphenoquine jetoxyethyl (meth)acrylate, Representative alkylphenoxypolyethoxyethyl (meth)acrylates, p-ethylphenoxyisoprobyl (meth)acrylate, p-butylphenoxydiisopropoxyisopropyl (meth)acrylate, p-nonylphenoxydiisopropoxyisopropyl Alkylphenoxypolyisopropoxyisopropyl (meth)acrylates represented by (meth)acrylate, p-cumylphenoxyethyl (meth)acrylate, and p-cumylphenoxyethoxyethyl (meth)acrylate represented by p-cumylphenoxyethoxyethyl (meth)acrylate. Cumylphenoxypolyethoxyethyl (meth)
Acrylates, p-cumylphenoxyisopropyl (
meth)acrylate, p-cumylphenoxypolyisopropoxyisopropyl (meth)acrylates represented by p-cumylphenoxydiisopropoxyisopropyl (meth)acrylate, p-benzylphenoxyethyl (meth)acrylate, p- p typified by benzylphenoxyjethoxyethyl (meth)acrylate, etc.
- p-Benzylphenoxypolyisoproboxyisopropyl (as represented by benzylphenoxypolyethoxyethyl (meth)acrylates, p-benzylphenoxyisopropyl (meth)acrylate, p-benzylphenoxydiynepropoxyisopropyl (meth)acrylate) Examples include meth)acrylates, but preferably alkylphenoxypolyethoxyethyl (meth)acrylic V-), alkylphenoxypolyisopropoxyisopropyl (meth)acrylates, p-cumylphenoxypolyethoxyethyl (meth) acrylates, p
-cumylphenoxypolyisopropoxyisopropyl (meth)acrylates, p-benzylphenoxypolyethoxyethyl (meth)acrylates, and p-benzylphenoxyisopropoxyisopropyl (meth)acrylates are preferred. The number of repeats of the ethoxy group and isopropoxy group in the polyethoxy group and polyisopropoxy group in the above monomers is preferably θ to 1
0, more preferably 1-5. If the number of repetitions exceeds 10, the water resistance and chemical resistance of the composition will drop significantly, which is not preferable. These (B) moimers can be used alone or in combination of two or more in any proportion. (0) As the photosensitizer, any known photosensitizer can be used, but it is desirable that it has good storage stability after being blended. Examples of such photosensitizers include benzoin ethyl ether,
Benzoin alkyl ether photosensitizers such as benzoin isobutyl ether nato, acetophenone photosensitizers such as 2,2-jetoxyacetophenone, 4'-phenoxy-2,2-dichloroacetophenone, 2-hydroxy-2-methyl Propiophenone, 4'-isopropyl-
Propiophenone photosensitizers such as 2-hydroxy-2-methylpropiophenone, anthraquinone photosensitizers such as 2-ethylanthraquinone, 2-t-butylanthraquinone, and 2-chloroanthraquinone, 2-chlorothioquina 2,4-diisopropylthiokey r't-
Examples include thioxanthone photosensitizers such as 2,4-dimethylthioquinone, and benzyl ketal photosensitizers such as benzyl dimethyl ketal. These photosensitizers can be used singly or in combination in any proportion.

The amount of (→ component) used in the composition of the invention is preferably 20 to 80% by weight of the composition, particularly preferably 35 to 75% by weight of the composition.
5-75% by weight. If the amount of the (4) component is less than 20% by weight, curability, hardness, and chemical resistance will be reduced, and if it is more than 80% by weight, printability and heat-resistant adhesion during solder immersion will be reduced.

The amount of component (B) is preferably 5 to 70% by weight, particularly preferably 10 to 500 to 50% by weight of the composition.
If the amount of the component is less than 5% by weight, curing stability with respect to film thickness cannot be obtained, and the effects of the present invention such as a decrease in heat resistance during solder immersion under humidified conditions cannot be obtained. If it exceeds 70% by weight, curability, water resistance, and chemical resistance decrease. (0) The amount of component is preferably 0.5 to 15% by weight of the composition,
Particularly preferably 1 to 8% by weight. (0) component is 05
If it is less than 1% by weight, the curing property by ultraviolet rays will be significantly reduced
If the amount exceeds 5% by weight, no significant improvement in performance is observed, making it impractical from a cost standpoint.

The composition of the present invention may further contain unsaturated compounds other than the unsaturated compound as component (1,) and the monomer as component (B). Examples of such unsaturated compounds include 2-hydroxyethyl (meth)acrylate, 2-
Hydroxypropyl (meth)acrylate, benzyl (
meth) acrylate, tetrahydrofurfuryl (meth)
Acrylate, synclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, (meth)acryloxyethyl phosphate, cellosolve (meth)acrylate, butyl selonulp (meth)acrylate, calpitol (meth)acrylate, butyl carpitol ( Monofunctional unsaturated compounds such as meth)acrylate, Hensyl (meth)acrylate, (meth)acrylic acid adduct of phenyl glycidyl ether,
Ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate ) acrylate, 1,6-hexanethiol di(
difunctional unsaturated compounds such as meth)acrylate, 1,3-butanediol di(meth)acrylate, bis[(meth)acryloxyethyl cyphosphate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ) acrylate, tris(2-hydroxyethyl)incyanuric acid (meth)acrylate,
Examples include polyfunctional unsaturated compounds such as glycerin tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and trimethylolpropane trioxyethyl(meth)acrylate. Among the compositions, when used on a 50-weight plate, curability, chemical resistance,
This is not preferable because the balance of heat resistance etc. will be lost.

The composition of the present invention is printed by a screen printing method or an offset printing method, and in order to improve printability in that case, extender pigments such as talc, calcium carbonate, alumina, barium sulfate, and mica, and leveling agents, Colored pigments, thixotropic agents, thickeners, chelating agents, etc. may be added to the composition of the present invention.

When the ink composition of the present invention is put into practical use, a desired portion is printed on the surface of a laminate with a conductive pattern formed by etching or plating by a method such as screen printing or offset printing, and then ultraviolet rays are irradiated to form a permanent protective film. Form.

For irradiation with ultraviolet rays, a high-pressure mercury lamp or a metal halide lamp of 50 to 2.00 W 7 cm is usually used, and curing can be completed within a short time of 20 seconds.

Example 1 Epicote 828 (as a bisphenol A epoxy)
(manufactured by Shell) 184. ! iI, 72 g of acrylic acid, 1 g of dimethylamine hydrochloride as a reaction catalyst, and 02 g of hydroquinone as a polymerization inhibitor were placed in a flask with a stirrer, and 1
The reaction was carried out at 00°0 until the acid value became 0.1 or less to obtain unsaturated compound A-1.

40 parts of the above unsaturated compound A-1, 4-0 parts of p-butylphenoxyethyl acrylate as the (B) monomer,
(0) 8 parts of benzyl dimethyl ketal as a photosensitizer;
Mix 16 parts of trimethylolpropane triacrylate as a saturated compound, further add 35 parts of talc as an extender, 2 parts of Ecosil as a thixotropic agent, and 0.3 parts of phthalocyanine green as a coloring pigment. Knead with a main roll. An ultraviolet curing solder resist ink was prepared. The above resist ink was screen printed into a desired pattern on a 100 μm thick conductor patterned laminate, and the resist ink was cured by irradiation with ultraviolet rays using an 80 W 7 cm high pressure mercury lamp.

The time required for curing was 10 seconds. The cured film thickness of the above ink was 15 μm on the conductor and 11.0 μm at the edge of the conductor.

The pencil hardness of the cured coating is 4H1 normal, 40°090%RH
After 4 hours of humidification treatment and 1 hour of immersion in 80°0 warm water, 260°020 seconds of solder immersion caused swelling,
No peeling occurred. Gold plating was performed on the exposed conductor portions, but no blistering or peeling occurred in the cured film of the resist ink. Further, the insulation resistance according to JIS Z3197 was 2×10 Ω.

Example 2 Epicote 807 (as bisphenol F type epoxy)
(manufactured by Shell) 170,9. 72 g of acrylic acid, 0.5 g of 2.4.6-)lis(dimethylaminemethyl)phenol as a reaction catalyst, 0.0 g of hydroquinone as a polymerization inhibitor.
．． 2 g was placed in a flask with a stirrer and reacted at 100°0 until the acid value became 0.1 or less to form an unsaturated compound A-
I got 2.

70 parts of the above unsaturated compound A-2, 20 parts of p-cumylphenoxyethyl acrylate as the (B) monomer, (
0) Mix 5 parts of 2-1-butylanthraquinone as a photosensitizer and 5 parts of hydroxyethyl methacrylate as other unsaturated compounds, furthermore, 20 parts of Merck as extender pigment, 10 parts of alumina, 1 part of thixotropic agent and Citerosil, 06 parts of phthalocyanine green was added as a coloring pigment, and cross-dispersion was performed using a sand mill to prepare an ultraviolet curing solder resist ink.

A desired pattern was printed using the above resist ink on a laminate plate having a 100 μm thick conductor pattern formed thereon by screen printing, and the above resist ink was cured by irradiation with a 100 W/am high pressure mercury lamp. The time required for curing was 9 seconds. The cured film thickness of the above ink is 14μ on the conductor, 100μ on the conductor edge, and the pencil hardness of the cured film is 4H1.
Normal condition, 40°0904RH 4 hours humidification treatment and 80°
2 (S000) immediately after being immersed in warm water at °C for 1 hour.No blistering or peeling occurred when immersed in solder for 20 seconds.

Gold plating was performed on the exposed conductor parts, but no blistering or peeling of the cured resist ink film occurred. Also, J I
Insulation resistance by S Z3197 is I x 1013
It was Ω.

Example 6 Epicote 154. as a novolac epoxy. (manufactured by Shell) and 72 g of acrylic acid were reacted in the same manner as in Example 1 to obtain unsaturated compound A-3.

65 parts of the above unsaturated compound A-3, (B) 60 parts of p-benzylphenoxyisopropyl acrylate as a monomer, (0) 5 parts of 2-hydroxy-2-methylpropiophenone as a photosensitizer, and other unsaturated compounds 30 parts of 1,6-hexanediol diacrylate were mixed as an extender, and 40 parts of talc and 5 parts of barium sulfate were added as extender pigments.
1 part of Erosil as a thixotropic agent and 0.5 part of phthalocyanine green as a coloring pigment were added and kneaded using three rolls to prepare an ultraviolet curing solder resist ink. A desired pattern was printed by screen printing on a laminate plate on which a conductor pattern with a thickness of 100 μm was formed using the above resist ink. The above resist ink was irradiated with ultraviolet rays using a tal halide lamp at a diameter of W/cm, and the cured film thickness of the ink was 16 μm on the conductor and 115 μm at the edge of the conductor. The pencil hardness of the cured coating is 5H1 normal, 40°09
No blistering or peeling occurred during humidification treatment for 04RH for 4 hours and solder immersion for 2600020 seconds immediately after immersion in 80°C warm water for 1 hour. Gold plating was performed on the exposed portion of the conductor, but no blistering or peeling occurred in the cured film of the resist ink. Also, J I 8 Z
The insulation resistance of 3197 was 1×1013Ω.

Example 4 Epicote 1001 as bisphenol A epoxy
(manufactured by Shell), 4.5.0 g, acrylic acid 72 g, toluene 2.00 as a solvent,! 9. 2 as a reaction catalyst
．． 4.6-tris(dimethylaminemethyl)phenol 0.59. After reacting 0.4 g of hydroquinone as a polymerization inhibitor in the same manner as in Example 1, the toluene removal operation was performed to obtain unsaturated compound A-4.

20 parts of the above unsaturated compound A-4, 20 parts of the unsaturated compound A-2 obtained in Example 2, p-
(0) 30 parts of diisopropylthioxanthone as a photosensitizer, 1 part of benzyl dimethyl ketal, 10 parts of 2-hydroxypropyl methacrylate as other unsaturated compounds
18 parts of neopentyl glycol diacrylate, and further added 60 parts of talc as an extender pigment and 10 parts of mica powder.
1.0 parts, 0.5 parts of Erosil as a thixotropic agent, and 0.4 parts of Phthalocyanine Green as a coloring pigment were added and kneaded using six rolls to prepare an ultraviolet curing solder resist ink.

A desired pattern was printed using the above resist ink on a laminate plate on which a conductor pattern with a thickness of 10 μm was formed by screen printing, and the above resist ink was cured by irradiation with ultraviolet rays using a 10 o w/cm metalnolide lamp. The time required for curing was 8 seconds.

The cured film thickness of the ink was 14 μm on the conductor and 110 μm at the edge of the conductor. The pencil hardness of the cured coating is 5H1
Normal condition, 40°090%RH 4 hour humidification treatment and 80°
C: No blistering or peeling occurred during solder immersion at 260° for 2.0 seconds immediately after immersion in warm water for 1 hour. Gold plating was performed on the exposed conductor portions, but no blistering or peeling occurred in the cured film of the resist ink. Also, J
l, insulation resistance by 5Z3197 is 2 x 10'''Ω
Met.

Example 5 Polyetherified bisphenol A 41 with 4 moles of ethylene oxide added to 1 mole of bisphenol A
144 g of acrylic acid and 200 g of toluene, 05 g of p-)luenesulfonic acid as a reaction catalyst, and 0.4 g of hydroquinone as a polymerization inhibitor were placed in a flask equipped with a stirrer, and an esterification reaction was carried out at 1000 C. After the reaction was completed, toluene was removed. was carried out to obtain unsaturated compound A-5.

30 parts of the above unsaturated compound A-, 5, 20 parts of the unsaturated compound A-3 obtained in Example 3, (B) 20 parts of p-benzylphenoxyjethoxymethyl methacrylate as a monomer, (0) light Mixed with 3 parts of 1-butylanthraquinone and 2 parts of 4'-phenoxy-2,2-dichloroacetophenone as a sensitizer, and 15 parts of dipentaerythritol hexaacrylate and 10 parts of 2-hydroxyethyl methacrylate as other monomers. Then, in the same manner as in Example 1, an ultraviolet curing solder resist ink was prepared.

5.1. Print a desired pattern using the above resist ink on a laminate plate with a 100μ thick conductor pattern formed thereon by screen printing. The resist ink was cured by irradiating ultraviolet rays with a high-pressure mercury lamp of 'o o w/cm. The time required for curing was 11 seconds. The cured film thickness of the ink was 16μ on the conductor and 108μ on the conductor edge.

The pencil hardness of the cured coating is 5H1 normal, 40°090%H
No blisters or flakes occurred during humidification treatment for 4 hours and immersion at 260° for 20 seconds immediately after immersion in 80°C hot water for 1 hour. Gold plating was performed on the exposed conductor portions, but no blisters, cracks, or flakes occurred on the cured film of the resist ink. Further, the insulation resistance according to JIS Z3197 was 2×1.0''Ω.

Example 6 2 propylene oxide for 1 mole of bisphenol F
Polyetherified product of bisphenol F with moles added 2
86 g, methacrylic acid 172 g, toluene 150 g, p-)luenesulfonic acid 03 g as a reaction catalyst, hydroquinone 0.4 g as a polymerization inhibitor in a flask equipped with a stirrer, and an esterification reaction was carried out at 1000 C. After the reaction was completed, toluene was removed. Unsaturated compound A-6 was obtained.

655 parts of the above unsaturated compound A, (B) 15 parts of p-ethylphenoxydiproboxybrobyl methacrylate as a monomer, (0) 2-hydroxy-2 as a photosensitizer
- 2 parts of methylglopiophenone, 2 parts of diisopropylthioxanthone, and 15 parts of dipentaerythritol hexaacrylate and 61 parts of neopentyl glycol diacrylate as other monomers were mixed, and a UV value and chemical resist ink was prepared in the same manner as in Example 1. Prepared.

A desired pattern was printed using the above resist ink on a laminate plate having a conductor pattern having a thickness of 100 μm by screen printing, and the above resist ink was cured by irradiating ultraviolet rays with a 160 W/cm high pressure mercury lamp.

The time required for curing was 7 seconds.

The cured film thickness of the above ink was 26 μm on the conductor and 120 μm at the conductor edge portion. The pencil hardness of the cured coating is 5.
kl, normal state, 40'09.0% FLH 260°02 immediately after 4-hour humidification treatment and 1-hour immersion in 80°C warm water
．． No blistering or peeling occurred during solder immersion for 0 seconds. Gold plating was performed on the exposed portions of the conductor, but no blistering or peeling occurred in the cured film of the resist ink. Also, the insulation resistance according to JIS Z51-97 is I
It was 1013.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Scope of Claims] (→An unsaturated compound having two or more (meth)acryloyl groups obtained by reacting an epoxy compound of polyhydric phenol or a polyether compound of polyhydric phenol with (meth)acrylic acid; B) General formula (1) [wherein, An ultraviolet curable solder resist ink composition containing as main components a monomer represented by (respectively) and (0) a photosensitizer.