JPS6210175A - Method of marking printed wiring board - Google Patents

Abstract

PURPOSE:To conduct printing having excellent adhesion and solvent resistance on a substrate with high accuracy, by printing a particular UV-curable marking ink compsn. on the surface of an epoxy-amino resin film formed on a printed wiring board, followed by curing. CONSTITUTION:30-90wt.% mixture of 90-10wt.% photopolymerizable prepolymer (e.g.: acrylate of diglycidyl ether of bisphenol A) with 10-90wt.% photopolymerizable monomer [e.g.: methyl (meth) acrylate] having at least one photopolymerizable double bond in its molecule is mixed with 0.05-20wt.% photoinitiator (e.g.: benzoin), 0.1-0.3 pigment for coloring (e.g.: TiO2), and 0.5-20wt.% photopolymerizable org. phosphorus compd. [e.g.: (meth) acryloyloxyethyl phosphate] to obtain a UV-curable marking ink compsn. The compsn. thus obtd. is printed on an epoxy-amino resin film having a thickness of 2-50mum formed on a printed wiring board so as to have a thickness of 1-30mum, followed by irradiation with an active light ray for curing.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for marking printed wiring boards using an ultraviolet curable marking ink.

(Prior art) Conventionally, the marking ink on the epoxy/amino resin coating film of printed wiring boards is a heat-curing type mainly composed of epoxy resin, melamine resin, urea resin, alkyd resin, or modified resins of these. It was hot. However, this marking ink has serious problems such as an increase in viscosity due to vaporization of the heat-curing solvent, which leads to blockage, and, in the case of amino resin inks, formaldehyde generation and air pollution due to the curing reaction in the case of amino resin inks.

To solve these problems, an ultraviolet curing marking ink has been developed and put into practical use, which is rapidly cured by ultraviolet irradiation and is solvent-free and highly safe.

(Problems to be Solved by the Invention) However, the ultraviolet curable marking ink of Ren is not suitable for use on commonly used ultraviolet curable solder resist ink films and on copper-clad laminate substrates (e.g. glass fiber reinforced epoxy). Although it exhibits sufficient adhesion on resin substrates, paper-reinforced phenolic resin substrates, polyimide substrates, etc., it has a serious defect in that it hardly adheres to epoxy/amino resin coating films.

(Means for Solving the Problems) As a result of intensive research in order to eliminate the above-mentioned drawbacks of the marking ink, the present inventors have developed a marking ink to be used on the epoxy/amino resin coating film. As photopolymerizable prepolymer (II), photopolymerizable monomer (I
It was discovered that the above-mentioned defects could be eliminated by adding a photopolymerizable organosin compound (V) to a marking ink composition containing a photoinitiator (I), a color pigment (IVI), and a coloring pigment (IVI) as essential components. invention has been achieved.

That is, the present invention provides a photopolymerizable prepolymer (II), a photopolymerizable monomer (II), and a photoinitiator (II) on the surface of an epoxy/amino resin film coated on a printed wiring board.
An ultraviolet curable marking composition containing ν, a coloring pigment (IV), and a photopolymerizable organosin compound (V)? This is a method for marking printed wiring boards, which is characterized by printing and curing.

The ultraviolet curable marking ink composition used in the invention has good adhesion to the epoxy/amine resin coating film.

Excellent working environment as no organic solvents are used.

Since it is an ultraviolet curing type, there is no change in viscosity during screen printing, and printing with good ffff is possible with a high mesh screen plate.

Excellent solvent resistance.

It has the following features.

Printed wiring boards used in the present invention include glass-reinforced epoxy resin boards, aluminum boards, and the like. An epoxy/amino resin film is provided on the printed wiring board.

In the present invention, the epoxy/amine resin refers to all the essential components of the epoxy resin and the amino resin. The epoxy resin used is a compound having two or more epoxy groups in the molecule, and is a polyglycidyl ether compound such as bisphenol A, bisphenol F, phenol novolac, cresol novolac, or alicyclic type. On the other hand, amine resins include polyurethane resins, melamine resins, guanamine resins, and the like. The ratio (weight ratio) of epoxy resin and amine resin is 9515 to 20/80, preferably 90/10 to
It is 50150. This epoxy amino-based [11 is
Curing resins such as phenol resins and alkyd resins may also be used in combination.

Epoxy/amino resins are usually added with organic solvents and curing accelerators and used to coat metals such as plastics, copper, iron, aluminum, and stainless steel.

Methods for coating the printed wiring substrate with heboxy-amino resin include floating knife coater, knife-over blanket coater, knife-over roll coater, triple reverse roll coater,
Common methods include a four-roll reverse tatami roll coater, a gravure coater, and a transfer method.

The ultraviolet curable marking ink composition used in the present invention includes a photopolymerizable prepolymer (I), a photopolymerizable monomer (II), a photoinitiator 1), and a coloring pigment (IV) s-
and photopolymerizable organic phosphorus compound (V)'.

The photopolymerizable prepoly 9(I) used in the present invention includes:
Examples include photopolymerizable epoxy acrylate compounds, epoxy methacrylate compounds, urethane acrylate compounds, and urethane methacrylate compounds.

Typical photopolymerizable epoxy (meth)acrylate compounds [(meth)acrylate represents acrylate v and methacrylate. The same abbreviations are given below. 〕as,(
II) (meth)acrylate compounds of polyglycidyl ethers of dihydric or higher polyhydric phenols, such as bisphenol-type epoxy compounds that are diglycidyl ethers such as bisphenol A, bisphenol F, and halogenated bisphenol A, phenol novolacs, and cresol novolaks. (II) (meth)acrylate compounds of polyglycidyl ethers of dihydric or higher polyhydric alcohols, such as ethylene glycol, propylene glycol, Neopentyl glycol, 1,4-butanediol, 196
-(meth)acrylate compounds of polyglycidyl ethers of dihydric or higher aliphatic alcohols such as hexanediol and trimethylolpronochloride; (li+) bisphenol A compounds such as ethylene oxide P and propylene oxide adducts of bisphenol A; di(meth)acrylates of alkylene oxide adducts; (meth)acrylate compounds, (V) (meth)acrylate compounds of polyglycidyl ether in which the active hydrogen bonded to the nitrogen atom of aniline, isocyanate acid, etc. is replaced with a glycidyl group, (by epoxidizing the olefin bond in the VD molecule) Obtained nt vinylcyclohexene dieboxide, 8.4-
(Meta) of alicyclic polyepoxy compounds such as epoxycyclohexylmethyl-314-epoxycyclohexanecarboxylate, 2-CB, 4-epoxy)cyclohexyl-5,5-spiro(8,4-epoxy)cyclohexane-m-dioxane Acrylate compounds, (v
ll) of aminopolyepoxy compounds such as N,N,N',N'-tetraglycidyl metaxylene diamine, N,N,N',N'-tetraglycidyl-1,3-bis(aminomethyl)cyclohexane (meth) ) acrylate compounds, etc. These epoxy acrylate compounds can be used alone or in combination of two or more.

Preferred epoxy acrylated comb compounds (II) among these include diglydyl ether of bisphenol A, phenol novolak type polyepoxy compounds, cresol novolac type polyepoxy compounds, and (meth) polyepoxy compounds of polyhydric alcohols. ) Acrylate compounds, etc.

Further, (meth)acrylate compounds of epoxy compounds having one epoxy group i in the molecule, such as allyl glycidyl ether and phenyl glycidyl ether, can also be used in combination.

Further, the photopolymerizable urethane (meth)acrylate compound having two or more terminal (meth)acrylate groups via a urethane bond used in the present invention can be prepared by, for example, reacting an organic diisocyanate compound with a hydroxyl group-containing (meth)acrylate compound. can be obtained by The reaction ratio between the organic diisocyanate compound and the hydroxyl group-containing (meth)acrylate compound is NGOloH<1 (equivalent ratio), preferably NGOloH<1/2.

Examples of organic diisocyanate compounds that are constituent molecules in the urethane (meth)acrylate compound used in the present invention include hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, xylylene diisocyanate, and bis(4-incyanate cyclohexyl)-methane. , bis(3-methyl-4-isocyanatecyclohexyl)-methane, 2,2-bis(
4-Isocyanate cyclohexyl)-propane, 2゜2.4-trimethylhexamethylene-1,6-diisocyanate, 4.4'-diphenylmethane diisocyanate, 4.4'-dimethyl diphenylmethane diisocyanate, 2,4.4-)dimethyl hexamethylene-1
, 6-diisocyanate, aliphatic, alicyclic or aromatic diisocyanates, terminal isocyanates of polyhydric alcohols such as ethylene glycol, propylene glycol, l,4-butanediol, l,6-hexanediol, neopentyl glycol, glycerin, etc. Compounds, polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyalkylene glycols having an incyanate group at the end, polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol, and phthalic acid; Examples include polyester urethanes having an incyanate group at the end of a reaction product of a polyhydric carboxylic acid such as isophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, and adipic acid.

As the hydroxyl group-containing (meth)acrylate compound which is a constituent molecule in the urethane (meth)acrylate compound used in the present invention, ethylene glycol mono(
meth)acrylate, l,2-propanediol mono(
(meth)acrylate compounds of polyhydric alcohols such as meth)acrylate, 1,4-butanediol mono(meth)acrylate, 1,6-hexanediol mono(meth)acrylate, neopentyl glycol mono(meth)acrylate, acetic acid , aliphatic carboxylic acids such as globionic acid, butyric acid, and adipic acid; ) Reaction products of acrylic acid, reaction products of glycidyl ethers of phenols such as phenol, cresol, bisphenol A, bisphenol F, halogenated bisphenol A, and (meth)acrylic acid.

Among the photopolymerizable prepolymers (II), preferred are urethane (meth)acrylate compounds, and particularly preferred are IL-terminated diisocyanate reaction products obtained from Monoke polyalkylene glycol and organic diisocyanate compounds, and hydroxyl It is a reaction product with a group-containing (meth)acrylate compound.

The photopolymerizable monomer (II) used in the present invention is a photopolymerizable compound having one or more photopolymerizable double bonds in the molecule. Examples of these photopolymerizable monomers (ID) include the following compounds.

Examples of photopolymerizable monomers having one photopolymerizable double bond in the molecule include (II) methyl (meth)acrylate, ethyl (meth)acrylate, n-P and i-propyl (methacrylate). , n-5ec-ν and t-
Butyl (meth)acrylate, 2-ethylhexyl (methacrylate), alkyl (methacrylates) such as lauryl (meth)acrylate, hydroxyalkyl (such as 2-hydroxyethyl (meth)acrylate)
meth)acrylates, or polyethylene glycol mono(meth)acrylate, polypropylene glycol;-
Addition of polyoxyalkylene glycol mono(meth)acrylates, tetrahydrofurfuryl (heterocycle-containing (meth)acrylates such as methocacrylate, dimethylaminoethyl(meth)acrylate, dibylene oxide) to 7 Mono (meth) of alkylene oxide adducts of bisphenol A such as
acrylates, (III) A diisocyanate compound and one or more alcoholic hydroxyl group-containing compounds are reacted in advance, and a terminal inocyanate group-containing compound is further reacted with an alcoholic hydroxyl group-containing V (meth)acrylate. Acrylic acid or methacrylic acid is reacted with the resulting urethane-modified mono (methacrylates, (IV) compound having one or more epoxy groups in the molecule) having one (meth)acryloyloxy group in the molecule. Epoxy mono(meth)acrylates, P and (
V) Oligoester mono(meth)acrylates obtained by reacting acrylic acid or methacrylic acid 2 or polyhydric carboxylic acid as a carboxylic acid component with a polyhydric alcohol having a valence of 2 or more as an alcohol component.

Two photopolymerizable double bonds in the molecule? Examples of photopolymerizable compounds include (II) ethylene glycol di(meth)acrylate, globileg glycol di(meth)acrylate, and 1-4-butanediol di(meth)acrylate.
acrylate, alkylene glycol di(meth)acrylates such as neobentyl glycol di(meth)acrylate, l,6-hexanethiol di(meth)acrylate, diethylene glycol di(meth)acrylate, and hydroxypiparic acid neopentyl glycol ester. Di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(
A terminal isocyanate group-containing compound obtained by reacting an alkylene glycol di(meth)acrylate such as meth)acrylate, an (I+) diisocyanate compound, and two or more alcoholic hydroxyl group-containing compounds in advance is further added with an alcoholic hydroxyl group-containing (meth) ) urethane-modified di[meth]acrylates having two (meth)acryloyloxy groups in the molecule obtained by reacting acrylates; (II) compounds having two or more epoxy groups in the molecule; Eboxy di(meth)acrylates obtained by reacting acrylic acid or I/'i, /ν and methacrylic acid, OV) acrylic acid or methacrylic acid 2 as a carboxylic acid component, and 2 as a polyhydric carboxylic acid and an alcohol component There are oligoester di(meth)acrylates obtained by reacting polyhydric alcohols with higher valences.

Examples of photopolymerizable compounds having 8 or more photopolymerizable double bonds in the molecule include (+) U methylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, and pentaerythritol tetra. Poly(meth)acrylates of trihydric or higher aliphatic polyhydric alcohols such as (meth)acrylate, pentaerythritol hexa(meth)acrylate, (II
) Urethane-modified poly(meth)acrylates having 8 or more (meth)acryloyloxy groups in the molecule obtained by reacting a diisocyanate compound with a (meth)acrylate containing 8 or more alcoholic hydroxyl groups, (I
I) There are epoxy poly(meth)acrylates obtained by reacting a compound having eight or more epoxy groups in the molecule with acrylic acid or /2 and methacrylic acid.

The blending ratio of photopolymerizable monomer (I) in the photopolymerizable prepolymer used in the present invention is (I):(II) = 90:10
~10:90 (wt%), preferably (
I): (II) 80:20~20:801tqb
) is within the range.

If the photopolymerizable prepolymer (I) exceeds 90 (t% by weight), the viscosity becomes too high, making screen printing difficult. If the amount is less than 10 (i% by weight), the adhesion to the epoxy or melamine resin coating film will be insufficient.

Relative to the total weight of the marking ink composition of the present invention ((
The blending amount of I) + (II)) is 80 to 90 (wt%
), preferably 40 to 85 (II%).

The photoinitiator (II) used in the ink of the present invention is a compound that promotes the photopolymerization reaction of a photopolymerizable compound, and includes, for example, ketals such as benzyl dimethyl ketal, benzyl dimethyl nityl, pensoyl, and Ethyl ether, benzoin-1 propyl ether,
Benzoins such as benzoin and α-methylbenzoin, anthraquinols such as 10-anthraquinone, l-chloroanthraquinone, 2-chloroanthraquinone, and 2-ethylanthraquinone, hensifhenone, P-
Benzophenones such as chlorbenzophenone and P-dimethylaminobenzophenone, 2-hydroxy-2-methylpropiophenone,! Propiophenones such as -(4-isopropylphenone)-2-hydroxy-2-methylpropiophenone, suberones such as dipenzosuberone, ionic compounds such as diphenyl disulfide, tetramethylthiuram disulfide, thioxanthone, methylene blue, eosin, Photoinitiators such as dyes such as fluorescein may be used alone or in combination of two or more.

In the marking ink composition of the present invention, the amount of this photoinitiator is 0.05% based on the total weight of the composition of the present invention.
~20 (t% by weight), preferably 1-10 (t% by weight).

Examples of the coloring pigment (g) used in the present invention include known inorganic and organic pigments such as titanium dioxide, azo pigments, and phthalocyanine pigments.
The o, i of the marking ink composition of the present invention is ~0.3 (wt%).

As the photopolymerizable organic phosphorus compound (v) which is the core of the present invention, (meth)acryloyloxyethyl phosphate, (meth)acryloyloxy-n-1- and -i-
Mepropyl phosphate (meth)acryloyloxyethyl phosphate, di(meth)acryloyloxy-
n-v and -1-propyl phosphate, tri(meth)
Acryloyloxyethyl phosphate, tri(meth)
Typical examples include (meth)acryloyloxyalkyl phosphates such as acryloyloxy-n-2 and -i-propyl phosphate. This photopolymerizable organic phosphorus compound (V) Iri alone can be used in combination with two or more types.

The organic phosphorus compound (Vl) of the present invention is 0.5 to 20 (in%) of the marking ink composition of the present invention,
Preferably it is 1-10 (wt%).

In addition to the above-mentioned essential components, the ultraviolet curable marking ink composition of the present invention can contain various other components as necessary to provide properties particularly required as a screen printing ink. . Examples include various inorganic fillers, thixotropic agents, leveling agents, coupling agents, antifoaming agents, plasticizers, flame retardants, polymerization inhibitors, and the like.

The ultraviolet curable marking ink composition of the present invention can be manufactured according to a conventional method using, for example, a three-roll mill, to give a marking ink with good storage stability.

Methods for printing the ultraviolet curable marking ink composition on the surface of the epoxy/amine resin film include screen printing, offset printing, tap/po printing, and gravure printing. The thickness of the ink layer is generally 1 to 80 μm.
, preferably 8 to 15 μm.

The ultraviolet curable marking ink composition of the present invention is cured by irradiation with actinic light such as ultraviolet rays or electron beams, for example, after printing or coating. Ultraviolet heat lamps are used.

(Effects of the Invention) The method of the present invention provides good adhesion of the marking ink composition to the (II)-epoxy-amine resin coating film.

(2) Since no specific solvent is used in the marking ink composition, the working environment for manufacturing printed wiring boards is excellent.

(8) Since the marking ink composition is UV-curable, there is little change in viscosity during screen printing, allowing for high mesh and
High-precision printing is possible with a screen plate.

(4) The cured film of the marking ink composition has features such as excellent solvent resistance.

(Examples) In order to explain the present invention more specifically, Examples are given below, but of course the present invention is not limited in any way by these Examples.

In the examples, parts 2 and 2 indicate parts by weight and % by weight, respectively.

Performance measurements in Example υ and Comparative Example were performed in accordance with the following method.

Adhesion〉 Marking ink composition cured film Purple cross-cut cellophane tape peeling test (JISL)-0202)
Adhesion was measured according to the following.

<Hardness> The cured film of the marking ink composition was subjected to a pencil hardness test (JIS
Hardness was measured according to L)-0202).

<Solvent Resistance> The cured film of the marking ink composition was rubbed back and forth 50 times with gauze impregnated with acetate/', and after being left at room temperature for 80 minutes, the hardness of the cured film was measured.

Coating film preparation example 1, coating film (I) Epoxy resin 70 parts Melamine resin 30 xylene
100 diacetate/alcohol 10
0 Hexahydrophthalic anhydride 2 at 1℃
After drying for 0 minutes, it was heat-treated at 150° C. for 1 hour.

2. Coating film (II) Epoxy resin 70 parts Melamine resin 30 Alkyd resin
80 Methyl ethyl ketone 100 Microhexanone 50 Butyl cellosolve 50 Hexahydrophthalic anhydride
2. A coating material having the above composition was coated on a paper-reinforced phenolic resin substrate to a thickness of 10 μm using a 3-tater,
After drying at 60°C for 20 minutes, it was heat-treated at 150°C for 1 hour.

3. Coating film (soda) Epoxy resin 70 parts Melamine resin 80 parts Phenol resin
20 xylene 10
0 diacetone alcohol 100 hexahydrophthalic anhydride 1 A coating material with the above composition was applied to a thickness of IQpm on a stainless steel substrate using a bar coater, dried at 60°C for 20 minutes, and then heat-treated at 150°C for 2 hours. did.

Example l PPG400/2IPDI/2HEA”)
85 parts 2-hydroxyethyl acrylate
18 trimethylolpropane triacrylate 4 dipentaeryth 11 toll hexaacrylate 4 diyt7F'y + coil oxye + L7F-sufz-1-de titanium dioxide
8 Irgajin Yellow 2G
LTE (color pigment manufactured by Ciba Geigy 4) 2-ethylanthraquinone
Iirgacure 651 (manufactured by Ciba Geigy)
4 photoinitiator) Talc
17 Antifoaming agent
over 0.5) polypropylene glycol (average molecular t4
oo) / isophorone diisocyanate / 2-hydroxyethyl acrylate = 1/2/2 (mole ratio) reaction product The above marking ink composition was prepared according to a conventional method using an 8-roll mill.

After printing the marking ink composition obtained on the epoxy/amine resin coating film (II0) with a polyester 300 mesh screen plate to a thickness of 10 pm,
Ultraviolet light (II-1-
5O0/, J) irradiated. Table 1 shows the measurement results of the performance of the obtained cured film.

Comparative Example 1 A marking ink composition was obtained in the same manner as in Example 1 except that dimethacroyl oxy7-ethyl phosphate was removed. Furthermore, printing in the same manner as in Example 1,
Table 1 shows the measurement results of the performance of the obtained cured film.

Example 2 A coating film (N) was replaced with an epoxy/amine resin coating film (N).
II) A cured film was obtained in the same manner as in Example 1 except that k was used. The results of measuring the performance of the obtained cured film are shown in the table below.
Shown in 1.

Comparative Example 2 In Example 2, dimethacroyloxyethylphos 7
A cured film was obtained in the same manner as in Example 2, except that Eto was removed. Table 1 shows the measurement results of the performance of the obtained cured film.

Example 3 A cured film was obtained in the same manner as in Example 1, except that a coating film (seal) was used in place of the epoxy-amine resin corneal membrane (II). Table 1 shows the measurement results of the performance of the obtained cured film.

Comparative Example 8 A cured film was obtained in the same manner as in Example 3 except that dimethacroyloxy7-ethyl phosphate was removed in Example 8. Table 1 shows the measurement results of the performance of the obtained cured film.

Example 4 SP50Ql (r Showa Kobunshi) group epoxy 4
0 parts acrylate) 2-hydroxyethyl acrylate
20 trimethylolpropane triacrylate
3 dipentaerythritol hexaacrylate
4 dimethacroyloxyethyl phosphate
5 Titanium dioxide
15 Irugaki Your 651 (mentioned above)
5 talc
10 Antifoaming agent 0.
5 The above marking ink composition was prepared according to a conventional method.
This was done using this roll. This marking ink composition was printed on the epoxy/amino resin coating film (I) to a thickness of 10 μm using a polyester 800 mesh screen plate, and then exposed to ultraviolet light using a 5.6KW high-pressure mercury lamp (air-cooled). II, 500 mJ/cj). Table 1 shows the measurement results of the performance of the obtained cured film.

Comparative Example 4 A cured film was obtained in the same manner as in Example 4 except that dimethacroyloxyethyl phosphate was removed.

Table 1 shows the measurement results of the performance of the obtained cured film.

Example 5 A cured film was obtained in the same manner as in Example 1, except that methacroyloxyethyl phosphate was used in place of bis-methacroyloxyethyl phosphate in Example IVcsy. Table 1 shows the measurement results of the performance of the obtained cured film.

Example 6 A cured film was obtained in the same manner as in Example 1 except that acryloyloxyethyl phosphate was used in place of dimethacroyloxyethyl phosphate in Example IGCy.

Table 1 shows the measurement results of the performance of the obtained cured film.

Claims (1)

[Claims] A photopolymerizable prepolymer (I), a photopolymerizable monomer (II), a photoinitiator (III), a coloring pigment (IV) and A method for marking printed wiring boards, which comprises printing and curing an ultraviolet curable marking ink composition containing a photopolymerizable organic phosphorus compound (V).