CN112126275A

CN112126275A - Photocurable composition for PCB containing alkenyl ether and/or oxetane and radical polymerizable compound

Info

Publication number: CN112126275A
Application number: CN202010976994.6A
Authority: CN
Inventors: 邹应全; 庞玉莲; 丁艳花; 辛阳阳; B·斯特雷梅尔
Original assignee: Sichuan Lekai New Material Co ltd
Current assignee: BAODING LUCKY INNOVATIVE MATERIALS Co.,Ltd.; Sichuan Lekai New Material Co.,Ltd.
Priority date: 2020-09-16
Filing date: 2020-09-16
Publication date: 2020-12-25

Abstract

A photocurable composition for printed circuit boards comprising the following components: (a) a photopolymerizable compound, (b) at least one infrared absorbing photosensitizer, (c) at least one photopolymerization initiator, wherein the photopolymerizable compound as the component (a) contains (a1) at least one radical polymerizable compound and (a2) at least one cationic polymerizable compound selected from alkenyl ether compounds and/or oxetane compounds, and the infrared absorbing photosensitizer as the component (b) contains at least one polymethine cyanine compound.

Description

Photocurable composition for PCB containing alkenyl ether and/or oxetane and radical polymerizable compound

Technical Field

The present invention relates to a photocurable composition for a Printed Circuit Board (PCB), which contains (a) a photopolymerizable compound, (b) at least one infrared absorbing photosensitizer, and (c) at least one photopolymerization initiator. The photocurable composition for PCB of the invention is suitable for preparing photosensitive ink. The photosensitive ink is also suitable for preparing Printed Circuit Boards (PCB).

Background

In recent years, the emerging digital ink-jet printing technology replaces the traditional screen printing technology, is popularized and applied in the production of PCBs, and is particularly ideal for the production of various and low-batch PCB products. The ink-jet printing is used as a brand new printing tool, belongs to full digital printing, can perform accurate area-selection printing when forming a resist, a solder resist and a symbol mark on a printed circuit board, does not need the procedures of screen printing, exposure, development and the like, completely breaks away from the complicated procedures of the traditional printing process, and has better fineness and high density and lower cost. And simultaneously, the processing process and the production period can be shortened to the maximum extent. Meanwhile, the ink-jet printing is an environment-friendly technology, and compared with the traditional screen printing technology, the energy utilization rate is greatly improved, and the generation of industrial wastewater is reduced. But the defects are that the curing light source used in the prior light curing ink technology for the PCB is an ultraviolet lamp (UV) or a UV-LED, and the safety and the manufacturing cost are still not satisfactory. Meanwhile, the penetrating power of ultraviolet light is weak, and some components or pigment substances with conjugated structures in the light curing formula have strong absorption to the ultraviolet light, so that the light intensity is seriously attenuated, the curing is incomplete and the performance of a light curing film is poor; easily produce ozone to pollute the environment, and the like. In addition, ultraviolet light has harm to human body, and the light source has short service life and higher price.

The photocuring technology mainly has two mechanisms of free radical curing and cationic curing, wherein the former has wide raw material sources, high formula adjustability and wide application, but the use of the photocuring technology is limited to a certain extent due to the problems of oxygen inhibition effect, large curing volume shrinkage (which causes poor imaging precision), poor adhesion and the like.

For example, patent CN201780018493.3 discloses a curable composition for inkjet, a cured product and a printed circuit board, which can obtain an ink having good surface curability and coating film characteristics, but the volume is easy to shrink during curing due to the design of a single radical curing system, and the adhesion of the film layer to the substrate is seriously affected. In addition, UV mercury lamps, which are used as a curing light source, have poor penetration and may result in incomplete curing of the underlying layer.

And the cationic photocuring has no oxygen inhibition, the shrinkage of the cured volume is small, the adhesive force of the base material is strong, the post-curing is strong, and the defect of free radical curing can be overcome. However, the existing ink jet printing ink compositions for printed wiring boards are mainly radical photopolymerization systems.

In view of the above problems, it is desirable to provide a radical-cation hybrid photocurable composition for printed circuit boards, which simultaneously performs radical polymerization and cation polymerization in the same system, makes the advantages and disadvantages of the two polymerization systems complement each other, and can effectively improve curing efficiency. Thereby obtaining the photosensitive ink with excellent performance from the photo-curing composition, and being particularly suitable for preparing PCB.

Disclosure of Invention

In view of the problems of the prior art, the present inventors have made intensive studies on a cationic photocurable composition and a radical-cationic photocurable composition suitable for a near-infrared light source. The present inventors have surprisingly found that a specific infrared absorbing photosensitizer-sensitized photopolymerization initiator is particularly suitable for initiating cationic polymerization of alkenyl ether compounds and oxetane compounds, which have a high reaction rate and a high curing rate. Further research has found that the initiator system of the present invention can also initiate cationic-radical hybrid polymerization reactions with good photosensitivity, in particular good sensitivity.

The photocurable composition for a printed circuit board of the present invention comprising a specific photopolymerizable compound, an infrared absorbing photosensitizer, and a photopolymerization initiator makes it possible to achieve cation-radical hybrid polymerization using infrared light instead of ultraviolet light as a light source. The infrared light has long wavelength and good penetrability, and can overcome the defect of poor polymerization of the bottom layer of the ink, thereby improving the adhesion of the ink. Cationic photopolymerization can overcome oxygen inhibition and improve surface polymerization. The infrared light polymerization has obvious thermal effect, and the photopolymerization speed is effectively improved. In addition, the infrared light has little harm to human bodies, the service life of the light source is longer, and the price is cheaper.

The photosensitive composition and the printing ink containing the photosensitive composition are also suitable for ink-jet printing, have excellent curing performance and resist oxygen polymerization, and the obtained cured coating has the characteristics of good adhesion, insulativity, hardness, heat resistance, acid and alkali resistance, solvent resistance, small shrinkage, higher sensitivity, steeper imaging side wall and the like, so the photosensitive composition and the printing ink containing the photosensitive composition are particularly suitable for preparing PCBs.

An object of the present disclosure is to provide a photocurable composition for printed circuit boards, which is radical-cation hybrid polymerized.

Another object of the present disclosure is to provide a photosensitive ink comprising the photocurable composition for a printed circuit board of the present invention.

It is a further object of the present disclosure to provide use of the photocurable composition or the photosensitive ink of the present invention in the preparation of a printed circuit board.

A final object of the present disclosure is a printed wiring board obtainable from the photocurable composition or the photosensitive ink of the present invention.

The technical scheme for achieving the purpose of the invention can be summarized as follows:

1. a photocurable composition for printed circuit boards comprising the following components:

(a) a photopolymerizable compound which is capable of forming a film,

(b) at least one infrared-absorbing photosensitizer,

(c) at least one kind of photopolymerization initiator,

wherein the photopolymerizable compound as the component (a) contains (a1) at least one radical polymerizable compound and (a2) at least one cation polymerizable compound selected from alkenyl ether compounds and/or oxetane compounds, and the infrared absorbing photosensitizer as the component (b) contains at least one polymethine cyanine compound.

2. The photocurable composition for printed circuit boards according to embodiment 1, wherein the radical polymerizable compound as component (a1) is an ethylenically unsaturated group-containing radical polymerizable compound, preferably a monofunctional compound, a difunctional compound, a trifunctional or higher-functional compound, and mixtures thereof, such as a mixture of a difunctional compound and a trifunctional compound.

3. The photocurable composition for a printed circuit board according to embodiment 1 or 2, wherein the radical polymerizable compound as the component (a1) is selected from at least one of radical polymerizable resins, 2-functional or more radical polymerizable monomers, and monofunctional radical polymerizable monomers.

4. The photocurable composition for a printed circuit board according to any one of embodiments 1-3, wherein the radical polymerizable compound as the component (a1) is selected from the group consisting of (meth) acrylate compounds, (meth) acryl compounds, vinyl derivatives, styrene compounds, anhydride compounds containing an ethylenically unsaturated double bond, N-vinylpyrrolidone, N-vinylformamide, and mixtures thereof.

5. The photocurable composition for printed circuit boards according to any one of embodiments 1 to 4, wherein the amount of the photopolymerizable compound as the component (a) is 50 to 99 wt%, preferably 60 to 95 wt%, based on the total weight of the curable composition.

6. The photocurable composition for a printed circuit board according to any one of embodiments 1-5, wherein the weight ratio of component (a1) to component (a2) is 1:10 to 20:1, preferably 1:5 to 10: 1.

7. The photocurable composition for printed circuit boards according to any one of embodiments 1 to 6, wherein the photocurable composition comprises at least one other cationically polymerizable compound different from component (a2), preferably selected from the group consisting of epoxy compounds and aziridine compounds.

8. The photocurable composition for a printed circuit board according to any one of embodiments 1-7, wherein the polymethine cyanine compound as the component (b) has an absorption maximum at 780nm to 2000 nm.

9. The photocurable composition for a printed circuit board according to any one of embodiments 1 to 8, wherein the polymethine cyanine compound as the component (b) has a structure represented by formula (I):

wherein

Y⁺Represented are bicyclic, tricyclic or higher heterocyclic rings having 8 to 18 ring members and containing 1 or 2 nitrogen atoms as ring members and carrying a positive charge,

y represents a bicyclic, tricyclic or higher heterocyclic ring having 8 to 18 ring members and containing 1 or 2 nitrogen atoms as ring members,

Y⁺and said heterocycle in the definition of Y may carry 1 or more substituents selected from halogen, CN, nitro, C₁-C₁₂Branched or unbranched alkyl, C₁-C₁₂Branched or unbranched alkoxy radical, C₁-C₁₂A substituent of a branched or unbranched alkylthio group or a phenylthio group, wherein said C₁-C₁₂Branched or unbranched alkyl, said C₁-C₁₂Branched or unbranched alkoxy radical, said C₁-C₁₂The alkyl groups in a branched or unbranched alkylthio group may be interrupted by 1 or more non-adjacent oxygen atoms;

preferably Y⁺and/Y is a structural unit shown as follows respectively:

indole salts/indoles

Phenyl [ e ]]Indole salts/phenyl [ e ]]Indoles

And/or phenyl [ c, d ]]Indole salts/phenyl [ c, d ]]An indole compound having a structure represented by formula (I),

wherein said indole salt/indole, phenyl [ e ]]Indole salts/phenyl [ e ]]Indole, and phenyl [ c, d ]]Indole salts/phenyl [ c, d ]]The indole may have 1 or more, preferably 1 or 2, substituents selected from halogen, CN, nitro and C on the benzene ring or naphthalene ring₁-C₁₂Branched or unbranched alkyl, C₁-C₁₂Branched or unbranched alkoxy radical, C₁-C₁₂A substituent of a branched or unbranched alkylthio group or a phenylthio group, wherein said C₁-C₁₂Branched or unbranched alkyl, said C₁-C₁₂Branched or unbranched alkoxy radical, said C₁-C₁₂The alkyl groups in a branched or unbranched alkylthio group may be interrupted by 1 or more non-adjacent oxygen atoms;

wherein R is₁Is selected from C₁-C₁₂Branched or unbranched alkyl and C₁-C₁₂A branched or unbranched alkoxy group, wherein said C₁-C₁₂Branched or unbranched alkyl and C₁-C₁₂The branched or unbranched alkoxy groups may be interrupted by 1 or more non-adjacent oxygen atoms, e.g. - [ -CH₂CHR-O-]_nThe polyether is shown, wherein n is 1-6, R is H or CH₃；

Wherein the ring carbon position shown by the arrow is a connecting site with the polymethine chain;

more preferably Y⁺and/Y is a structural unit shown as follows respectively:

and/or

Wherein R is₁Is selected from C₁-C₁₂Branched or unbranched alkyl and C₁-C₁₂A branched or unbranched alkoxy group, wherein said C₁-C₁₂Branched or unbranched alkyl and C₁-C₁₂The branched or unbranched alkoxy groups may be interrupted by 1 or more non-adjacent oxygen atoms, e.g. - [ -CH₂CHR-O-]_nThe polyether is shown, wherein n is 1-6, R is H or CH₃(ii) a And

R₂，R₃independently of one another, selected from H, halogen, CN, nitro, C₁-C₁₂Branched or unbranched alkyl, C₁-C₁₂Branched or unbranched alkoxy radical, C₁-C₁₂A branched or unbranched alkylthio group or a phenylthio group, wherein said C₁-C₁₂Branched or unbranched alkyl, said C₁-C₁₂Branched or unbranched alkoxy radical, said C₁-C₁₂The alkyl groups in a branched or unbranched alkylthio group may be interrupted by 1 or more non-adjacent oxygen atoms;

n₁，n₂independently 0, 1 or 2; preferably 0 or 1, more preferably 1;

b and C are independently selected from H, C₁-C₁₂Alkyl groups or together with the carbon atoms linking them form a five-or six-membered ring;

a is selected from the structures shown as A-1 to A-13:

or C₁-C₁₂A branched or unbranched alkoxy group (A-13);

wherein

Denotes the attachment site to the structure of formula (I),

wherein "R₂And R₂The "radicals, which are identical or different, are each independently selected from hydrogen, halogen, C₁-C₆Branched or unbranched alkyl, C₁-C₆Branched or unbranched alkoxy radical, C₁-C₆A branched or unbranched alkylthio group or a phenylthio group,

preferably the group A is selected from the structures shown as A-4, A-5 or A-7 to A-13;

when the A group is a group A-1 or A-2, n₃Is 0, when the A group is a group A3-A13, n₃Is1, and X^-Represents a counter ion.

10. The photocurable composition for printed circuit boards according to embodiment 9, wherein the compound of formula (I) satisfies one or more of the following conditions:

R₁is selected from C₁-C₆Branched or unbranched alkyl and C₁-C₆A branched or unbranched alkoxy group, wherein said C₁-C₆Branched or unbranched alkyl and C₁-C₆The branched or unbranched alkoxy groups may be separated by 1 or 2 non-adjacent oxygen atoms;

R₂selected from H, halogen, nitro, C₁-C₆Branched or unbranched alkyl and C₁-C₆A branched or unbranched alkoxy group, wherein said C₁-C₆Branched or unbranched alkyl, said C₁-C₆The branched or unbranched alkoxy groups may be separated by 1 or 2 non-adjacent oxygen atoms;

R₃selected from H, C₁-C₆Branched or unbranched alkyl and C₁-C₆A branched or unbranched alkoxy group, wherein said C₁-C₆Branched or unbranched alkyl and said C₁-C₆The branched or unbranched alkoxy groups may be separated by 1 or 2 non-adjacent oxygen atoms.

11. The photocurable composition for printed circuit boards according to embodiment 9 or 10, wherein X^-Represents the following counterions: BF (BF) generator₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、[PF₃(C₂F₅)₃]^-、[Al(OC(CF₃)₃)₄]^-、[B(PhF₅)₄]^-、[B(Ph(CF₃)₂)₄]^-、[((CF₃)₂SO₂)₂N]^-、[((CF₃)₂SO₂)₃C]^-、Cl^-、Br^-、F^-、[Al(O-t-C₄F₉)₄]^-、[Al(O-(i-C₃F₇)CH₃)₄]^-、[C(O-SO₂CF₃)₃]^-、[n-C₁₂H₂₅-TsO]^-Or [ NTf₂]^-Among them, BF is preferred₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、[PF₃(C₂F₅)₃]^-、[Al(OC(CF₃)₃)₄]^-、[B(PhF₅)₄]^-、[B(Ph(CF₃)₂)₄]^-、[((CF₃)₂SO₂)₂N]^-、[((CF₃)₂SO₂)₃C]^-、[Al(O-t-C₄F₉)₄]^-、[Al(O-(i-C₃F₇)CH₃)₄]^-Or [ NTf₂]^-More preferably, [ PF ]₃(C₂F₅)₃]^-、[Al(OC(CF₃)₃)₄]^-、[B(PhF₅)₄]^-、[B(Ph(CF₃)₂)₄]^-、[((CF₃)₂SO₂)₂N]^-、[((CF₃)₂SO₂)₃C]^-、[Al(O-t-C₄F₉)₄]^-Or [ Al (O- (i-C) ]₃F₇)CH₃)₄]^-Most preferably, [ Al (O-t-C)₄F₉)₄]^-Or [ PF ]₃(C₂F₅)₃]^-。

12. The photocurable composition for a printed circuit board according to any one of embodiments 1 to 11, wherein the infrared absorbing photosensitizer as component (b) is selected from one or more of the following compounds S1 to S70:

。

13. the photocurable compound for a printed circuit board according to any one of embodiments 1 to 12, wherein the photopolymerization initiator as the component (c) may be a photopolymerization initiator capable of generating radicals and cations in the presence of the component (b).

14. The photocurable compound for a printed circuit board according to any one of embodiments 1 to 13, wherein the photopolymerization initiator as the component (c) is selected from the group consisting of iodonium salt, sulfonium salt, triazine, and oxime ester type photopolymerization initiators.

15. The photocurable composition for a printed circuit board according to any one of embodiments 1-14, wherein the photopolymerization initiator as component (c) is an iodonium salt, preferably selected from the group consisting of iodonium salts represented by formula II:

wherein R is₁’-R₆' may be the same or different and are independently selected from H, halogen, nitro, C₁-C₂₀Branched or unbranched alkyl, C₁-C₂₀Branched or unbranched alkoxy and C₁-C₂₀A branched or unbranched alkylthio group, and X'^-X in the compound of formula (I) as in embodiment 9 or 11^-The definition of the content of the compound is as follows,

x in the compounds of the formula (I) is preferred^-And X 'in the compound of formula (II)'^-Are the same.

16. The photocurable composition for printed circuit boards according to any one of embodiments 1 to 15, wherein the photopolymerization initiator as the component (c) IS selected from one or more of the following compounds IS1-IS 40:

。

17. the photocurable composition for a printed circuit board according to any one of embodiments 1 to 16, wherein the weight ratio of the infrared absorbing photosensitizer as the component (b) to the photopolymerization initiator as the component (c) is 50:1 to 1:50, preferably 10:1 to 10, more preferably 5:1 to 1: 5.

18. The photocurable composition for printed circuit boards according to any one of embodiments 1 to 17, wherein the amount of the infrared absorbing photosensitizer as component (b) is from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight, based on the total weight of the photocurable composition.

19. The photocurable composition for printed circuit boards according to any one of embodiments 1 to 18, wherein the amount of the photopolymerization initiator as the component (c) is 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the total weight of the photocurable composition.

20. A photosensitive ink comprising the photocurable composition for a printed circuit board according to any one of embodiments 1 to 19.

21. Use of the photosensitive composition for a printed circuit board according to any one of embodiments 1 to 19 or the photosensitive ink according to embodiment 20 for producing a printed circuit board.

22. Use according to embodiment 21 for forming resists, solder resists and/or symbol markings on printed circuit boards, preferably by ink-jet means.

23. A printed wiring board obtainable from the photocurable composition for a printed wiring board according to any one of embodiments 1 to 19 or the photosensitive ink according to embodiment 20.

Description of the drawings:

FIG. 1: the heat flow of the sample versus exposure time in example 78.

FIG. 2: graph of cure rate versus exposure time for different monomers in example 79.

Detailed Description

Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps) are not essential unless otherwise explicitly stated. The same applies to values and ranges, without limiting the invention.

Herein, "(meth) acrylic acid" means acrylic acid or methacrylic acid, "(meth) acrylate" means acrylate or methacrylate, and "(meth) acryl" means acryl or methacryl.

In addition, the numerical ranges used herein represent ranges in which the numerical values recited before and after are respectively the minimum value and the maximum value.

Specific values (including range endpoints) disclosed herein for related features can be combined with each other to form new ranges.

In the present invention, the prefix "C_n-C_m"in each case denotes that the number of carbon atoms contained in the radical is n to m.

"halogen" refers to fluorine, chlorine, bromine and iodine. In the present invention, it is preferred that the halogen comprises F, Cl or a combination thereof. "halo" means substituted by one or more of the same or different halogen atoms.

The term "C" as used herein, alone or in combination_n-C_mAlkyl "and" C_n-C_mUnbranched or branched alkyl "and means branched or unbranched saturated hydrocarbon radicals having n-m, for example 1-20, preferably 1-12, more preferably 1-8, particularly preferably 1-6, for example 1-5 or 1-4, carbon atoms, for example methyl, ethyl, propyl, isopropyl,1-methylethyl group, butyl group, 1-methylpropyl group, 2-methylpropyl group, 1-dimethylethyl group, pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 2-dimethylpropyl group, 1-ethylpropyl group, hexyl group, 1-dimethylpropyl group, 1, 2-dimethylpropyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 1-dimethylbutyl group, 1, 2-dimethylbutyl group, 1, 3-dimethylbutyl group, 2-dimethylbutyl group, 2, 3-dimethylbutyl group, 3-dimethylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1, 2-trimethylpropyl group, 2-dimethylpropyl group, 1-dimethylethyl group, 2-methylpentyl, 1,2, 2-trimethylpropyl, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl and isomers thereof. C₁-C₈The alkyl group may be methyl, ethyl, propyl, isopropyl, n-butyl, 2-butyl, t-butyl, pentyl, isopentyl, hexyl, heptyl, octyl, and isomers thereof. C₁-C₆The alkyl group may be methyl, ethyl, propyl, isopropyl, n-butyl, 2-butyl, t-butyl, pentyl, isopentyl, hexyl and isomers thereof. C₁-C₄The alkyl group may be methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, 1-dimethylethyl, and isomers thereof.

The term "C" as used herein₂-C_mAlkenyl "means a branched or unbranched unsaturated hydrocarbon group having 2 to m, for example 2 to 20, preferably 2 to 6, more preferably 2 to 4 carbon atoms and having one double bond at any position, such as ethenyl, 1-propenyl, 2-propenyl, 1-methylethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-methyl-1-propenyl, 2-methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-methyl-1-butenyl, 2-methyl-4-butenyl, 2-methyl-1-propenyl, 2-methyl-propenyl, 3-methyl-1-butenyl, 1-methyl-2-butenyl, 2-methyl-2-butenyl, 3-methyl-2-butenyl, 1-methyl-3-butenyl, 2-methyl-3-butenyl, 3-methyl-3-butenyl, 1-dimethyl-2-propenyl, 1, 2-dimethyl-1-propenyl, 1, 2-dimethyl-2-propenyl, 1-ethyl-1-propenyl, 1-ethyl-2-propenyl, 1-hexenyl, 2-hexenyl, 3-hexylAlkenyl, 4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 2-methyl-1-pentenyl, 3-methyl-1-pentenyl, 4-methyl-1-pentenyl, 1-methyl-2-pentenyl, 2-methyl-2-pentenyl, 3-methyl-2-pentenyl, 4-methyl-2-pentenyl, 1-methyl-3-pentenyl, 2-methyl-3-pentenyl, 3-methyl-3-pentenyl, 4-methyl-3-pentenyl, 1-methyl-4-pentenyl, 2-methyl-4-pentenyl, 3-methyl-4-pentenyl, 4-methyl-4-pentenyl, 1-dimethyl-2-butenyl, 1-dimethyl-3-butenyl, 1, 2-dimethyl-1-butenyl, 1, 2-dimethyl-2-butenyl, 1, 2-dimethyl-3-butenyl, 1, 3-dimethyl-1-butenyl, 1, 3-dimethyl-2-butenyl, 1, 3-dimethyl-3-butenyl, 2-dimethyl-3-butenyl, 2, 3-dimethyl-1-butenyl, 2, 3-dimethyl-2-butenyl, 2, 3-dimethyl-3-butenyl, 1, 3-dimethyl-2-butenyl, 1, 3-dimethyl-3-butenyl, 2, 3-dimethyl-2-butenyl, 2,3, 3-dimethyl-1-butenyl, 3-dimethyl-2-butenyl, 1-ethyl-1-butenyl, 1-ethyl-2-butenyl, 1-ethyl-3-butenyl, 2-ethyl-1-butenyl, 2-ethyl-2-butenyl, 2-ethyl-3-butenyl, 1, 2-trimethyl-2-propenyl, 1-ethyl-1-methyl-2-propenyl, 1-ethyl-2-methyl-1-propenyl, 1-ethyl-2-methyl-2-propenyl, and isomers thereof. C₂-C₆The alkenyl group may be vinyl, propenyl, 1-butenyl, 2-butenyl, isobutenyl, 1-pentenyl, 2-pentenyl, neopentynyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, isohexenyl, neohexenyl and isomers thereof. C₂-C₄The alkenyl group may be vinyl, 1-propenyl, 2-propenyl, 1-methylvinyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-methyl-1-propenyl, 2-methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-2-propenyl, and isomers thereof.

The term "C" as used herein₃-C_mCycloalkyl "means a saturated alicyclic monocyclic group having 3 to m, such as 3 to 20, preferably 3 to 8, more preferably 5 to 6, ring carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and cyclodecyl.

The term "C_n-C_mAlkoxy "and" C_n-C_mAlkylthio "means at C_n-C_mOpen chain corresponding to alkylC_n-C_mC having an oxygen or sulfur atom as a linking group bonded to any carbon atom of the alkane_n-C_mAlkyl radicals, e.g. C₁-C₂₀Alkoxy (or thio) radicals, preferably C₁-C₁₂Alkoxy (or thio) radicals, more preferably C₁-C₈Alkoxy (or thio) radicals, particularly preferably C₁-C₆Alkoxy (or thio) radicals, particularly preferably C₁-C₄Alkoxy (or thio) group. C₁-C₈The alkoxy group may be methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, 2-butoxy, tert-butoxy, pentoxy, isopentoxy, hexoxy, heptoxy, octoxy, isooctoxy and isomers thereof. C₁-C₄The alkoxy group may be methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy and isomers thereof. C₁-C₈The alkylthio group may be methylthio, ethylthio, propylthio, isopropylthio, n-butylthio, 2-butylthio, t-butylthio, pentylthio, isopentylthio, hexylthio, heptylthio, octylthio, isooctylthio and isomers thereof. C₁-C₄The alkylthio group can be methylthio, ethylthio, propylthio, isopropylthio, n-butylthio and isomers thereof.

For Y⁺Y is a bicyclic, tricyclic or higher heterocyclic ring having 8 to 18 ring members and containing 1 or 2 nitrogen atoms as ring members, preferably a bicyclic or tricyclic heterocyclic ring having 8 to 14 ring members and containing 1 nitrogen atom as ring member.

A first aspect of the present disclosure relates to a photocurable composition for a printed circuit board, which contains the following components:

(a) a photopolymerizable compound which is capable of forming a film,

(b) at least one infrared-absorbing photosensitizer,

(c) at least one kind of photopolymerization initiator,

wherein the photopolymerizable compound as the component (a) contains (a1) at least one radical polymerizable compound and (a2) at least one cation polymerizable compound selected from alkenyl ether compounds and/or oxetane compounds, and the infrared absorbing photosensitizer as the component (b) contains at least one polymethine cyanine compound. A radically polymerizable compound (a 1).

According to a preferred embodiment of the present invention, the radical polymerizable compound is a radical polymerizable compound containing an ethylenically unsaturated group. The radical polymerizable compound may be in the form of a monomer or a resin (including oligomers and prepolymers).

The radical polymerizable compound includes a radical polymerizable monofunctional compound, difunctional compound, trifunctional or higher functional compound and a mixture thereof, preferably a monofunctional compound, a mixture of difunctional and trifunctional compounds or a mixture of two or more difunctional compounds.

Free radical polymerizable monofunctional Compound

The radical polymerizable monofunctional compound has a low viscosity, and examples of the photoreactive diluent include (meth) acrylate compounds, (meth) acryl compounds, vinyl derivatives, styrene compounds, acid anhydride compounds (maleic anhydride) containing an ethylenically unsaturated double bond, N-vinylpyrrolidone, and N-vinylformamide.

The following examples may be mentioned as preferred (meth) acrylate compounds:

(meth) acrylic acid C₁-C₁₈Alkyl esters, e.g. C (meth) acrylate₁-C₆Examples of the alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and 2-methacryloyloxyethoxy phthalate;

hydroxy-functional (meth) acrylates, e.g. hydroxy C (meth) acrylate₁-C₆Alkyl esters, examples being (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, glycidyl methacrylate, etc.;

(meth) acrylates having a cyclic skeleton such as isobornyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, glycidyl (meth) acrylate, γ -butyrolactone (meth) acrylate, tricyclodecanol (meth) acrylate; and

alkoxy-modified (e.g. having 1 to 10, such as 2,4,6 or 8, preferably 1 to 5 EO and/or PO units) esters of (meth) acrylic acid with EO, PO and the like, for example, methoxy diethylene glycol (meth) acrylate, methoxy triethylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate.

As the (meth) acryloyl group, there may be mentioned acryloylmorpholine and the like, 2-methacryloyloxyethoxysuccinate, N-dimethylacrylamide, N-diethylacrylamide, N-dipropylacrylamide and the like.

As the styrenic compound, chloromethyl styrene and α -methyl styrene can be mentioned.

As the acid anhydride having an ethylenically unsaturated double bond, maleic anhydride and the like can be mentioned.

Mention may be made, as ethylene derivatives, of vinyl esters, preferably C₂-C₆Vinyl esters of monocarboxylic acids, such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, vinyl hexanoate or mixtures thereof.

The radical polymerizable monofunctional compound may be present in an amount of 10 to 80% by weight, based on the total weight of the photocurable composition of the present invention.

Free radical polymerizable bifunctional compound

The radical polymerizable bifunctional compound has higher reactivity than the monofunctional compound, and can improve the surface curability of the ink. The viscosity of the light-cured composition is lower than that of a free radical polymerization trifunctional compound, and the light-cured composition can be well used as a diluent of a trifunctional and higher-functional compound by being combined with a monofunctional compound, so that the viscosity of the light-cured composition and the light-sensitive ink is reduced, and the reactivity is improved.

As radically polymerizable difunctional compounds, for example di (meth) acrylates of diols or triols having 2 to 12, such as 2,4,6, 8 or 10, carbon atoms, di (meth) acrylates of polyethylene or polypropylene glycols having a number average molecular weight of not more than 1500, for example not more than 1200, wherein these compounds are optionally modified with EO or PO, such as with 5 to 15 EO and/or PO; as concrete examples, there may be mentioned 2-hydroxy-3-acryloxypropyl (meth) acrylate, neopentyl glycol di (meth) acrylate, 1, 3-butanediol di (meth) acrylate, 2-methyl-1, 3-butanediol di (meth) acrylate, 1, 4-butanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, 1, 9-nonanediol di (meth) acrylate, 1, 10-decanediol di (meth) acrylate, 3-methyl-1, 5-pentanediol di (meth) acrylate, ethoxylated 1, 6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, propoxylated neopentyl glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth), Polyethylene glycol #400 di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol #400 di (meth) acrylate, polypropylene glycol (#700) di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol #200 di (meth) acrylate, polyethylene glycol #600 di (meth) acrylate, polyethylene glycol #1000 di (meth) acrylate, ethoxylated polypropylene glycol #700 di (meth) acrylate, polypropylene glycol #400 di (meth) acrylate, bisphenol A di (meth) acrylate (which may contain different alkoxy segments such as EO and PO), etc.), Hydrogenated bisphenol A type di (meth) acrylate (which may contain different alkoxy segments such as EO, PO, etc.), dicyclopentadiene, 2-bis (4- (methacryloxypolyethoxy) phenyl) propane (the average number of EO units is 5 to 15 per molecule), etc. 1 or 2 or more of them may be used.

Di (meth) acrylates of polyethylene glycols having a number average molecular weight of not more than 1200 (for example not more than 800) and 2, 2-bis (4- (methacryloxypolyethoxy) phenyl) propane (with an average number of EO units of from 5 to 15 per molecule) and mixtures thereof are preferred.

The radically polymerizable difunctional compound may be 10 to 80% by weight, for example 20%, 30%, 40%, 50%, 60% or 70% by weight, based on the total weight of the photocurable composition of the present invention.

Radically polymerizable trifunctional or higher functional compounds

As the 3-or more functional radical polymerizable compound, there may be mentioned a compound having three or more (meth) acrylate groups. Specific examples include: and polyfunctional acrylates represented by trimethylolpropane triacrylate, ethylene oxide-modified trimethylolpropane triacrylate, propylene oxide-modified trimethylolpropane triacrylate, epichlorohydrin-modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetra (meth) acrylate, tetramethylolmethane tetraacrylate, ethylene oxide-modified phosphoric triacrylate, propylene oxide-modified phosphoric triacrylate, epichlorohydrin-modified glycerol triacrylate, dipentaerythritol hexaacrylate, ditrimethylolpropane tetraacrylate, or silsesquioxane-modified products thereof, and methacrylate monomers corresponding thereto, and caprolactone-modified triacryloxyethyl isocyanurate.

The amount of free-radically polymerizable trifunctional or higher-functional compound may be from 5 to 80 wt.%, for example 10, 20, 30, 40, 50, 60 or 70 wt.%, based on the total weight of the photocurable composition of the present invention.

In one embodiment of the present invention, the radical polymerizable compound is in the form of a resin (including an oligomer or a prepolymer). As the radical polymerizable resin, there can be mentioned epoxy (meth) acrylate resin, polyester-based (meth) acrylate, urethane (meth) acrylate, ethylenically unsaturated polyester, amino (meth) acrylate resin, photo-imageable alkali-soluble resin, and the like. According to the invention, it is advantageous to use epoxy (meth) acrylate resins, polyester (meth) acrylates, polyurethane (meth) acrylates or combinations thereof.

The epoxy (meth) acrylate resin is preferably bisphenol A epoxy (meth) acrylate, tripropylene glycol di (meth) acrylate diluted bisphenol A epoxy acrylate or a combination thereof, such as bisphenol A epoxy acrylate WSR-U125 from a tin-free resin plant, bisphenol A epoxy acrylate 621A-80 from Taiwan Changxing chemical company diluted with 20% tripropylene glycol diacrylate, modified bisphenol A epoxy acrylate 623-100 from Taiwan Changxing chemical company, and modified bisphenol A epoxy acrylate 6231A-80 from Taiwan Changxing chemical company diluted with 20% tripropylene glycol diacrylate.

The polyester (meth) acrylate is preferably a hyperbranched polyester acrylic resin having a high functionality, in particular a hyperbranched polyester acrylic resin having a functionality of 5 to 30, for example a hyperbranched polyester acrylate prepolymer having a functionality of 6 to 20. As such, for example, there may be mentioned hyperbranched polyester acrylate prepolymer 932-. Polyester-based (meth) acrylates mention may also be made of 20% ethoxylated trimethylolpropane triacrylate diluted polyester polyol acrylic resins.

The urethane (meth) acrylate is preferably an aliphatic urethane acrylate. As such, aliphatic urethane hexaacrylate 6145-100, 6161-100, 15% 1, 6-hexanediol diacrylate (HDDA) diluted aliphatic urethane diacrylate 611B-85, aliphatic urethane diacrylate 6141H-80; aliphatic urethane acrylate CN9013(9 functionality) from sartomer usa, aliphatic urethane acrylate CN966B85(2 functionality) diluted with 15% 1, 6-hexanediol diacrylate (HDDA) from sartomer usa, aliphatic urethane acrylate CN962(2 functionality).

According to the present invention, the amount of the radical polymerizable resin may be 12 to 80% by weight, for example, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 40% by weight, 50% by weight, 60% by weight, 70% by weight, preferably 15 to 75% by weight, based on the total weight of the photocurable composition.

According to the present invention, it is most preferred that the radically polymerizable compound as component (a1) is a mixture of difunctional and trifunctional compounds, for example a mixture of trimethylolpropane tri (meth) acrylate and di (meth) acrylate of a diol or triol having 2 to 12, such as 2,4,6, 8 or 10, carbon atoms. In the mixture of difunctional and trifunctional compounds, the ratio of difunctional and trifunctional compounds may be from 10:1 to 1:10, preferably from 5:1 to 1:5, for example 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1: 4.

According to the present invention, the amount of the radical polymerizable compound as the component (a1) may be 30 to 90% by weight, for example, 40% by weight, 50% by weight, 60% by weight, 70% by weight, 80% by weight, preferably 40 to 80% by weight, based on the total weight of the photocurable composition of the present invention.

Component (a2)

According to the present invention, the component (a2) is at least one cationically polymerizable compound selected from the group consisting of alkenyl ether-based compounds and/or oxetane-based compounds, which may be in the form of a monomer or a resin (including an oligomer or a prepolymer).

In the present invention, the alkenyl ether compound may be C₁-C₆Alkenyl ether compounds such as vinyl ether, 1-propenyl ether, 1-butenyl ether, 1-pentenyl ether and the like, and vinyl ether compounds are preferred. The alkenyl ether compounds are, for example, alkenyl ethers starting from monohydric alcohols having 1 to 12, preferably 1 to 6, carbon atoms, dihydric alcohols having 2 to 12, preferably 2 to 8, carbon atoms, trihydric or higher alcohols having 3 to 12, preferably 3 to 6, carbon atoms, in particular C₁-C₆An alkenyl ether. As said alkenyl ether compounds, mention may also be made of polymers containing alkenyl ether, such as vinyl ether, functional groups. Mention may be made, as specific examples, of triethylene glycol divinyl ether, isobutyl vinyl ether, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, isopropyl vinyl ether, Butyl Vinyl Ether (BVE), hydroxyethyl vinyl ether, diethylene glycol divinyl ether (DEGDVE), triethylene glycol divinyl ether (TEGDVE), vinyl n-octyl ether, divinyl-1, 4-butane divinyl etherOne or a combination of two or more of glycol ether, 2-ethylhexyl vinyl ether, 1, 4-cyclohexanedimethanol divinyl ether, 4-hydroxybutyl vinyl ether (HBVE), triethylene glycol divinyl ether (DVE-3), glycerol carbonate vinyl ether, dodecyl vinyl ether, and the like. Further, there can be mentioned compounds having both vinyl ether and alkyl (meth) acrylate structures, and one or more of these compounds may be used simultaneously.

The alkenyl compounds also include carbamates containing 1 or more, e.g., 1 to 3, alkenyl ether structures. The urethane containing an alkenyl ether structure can be obtained by reacting an alkenyl ether having a hydroxyl group with an isocyanate compound (e.g., a polyisocyanate compound). Mention may be made, as examples, of bisvinyloxyalkylcarbamates and trifunctional vinyl ethers prepared from 1, 6-hexamethylene diisocyanate trimer and 4-hydroxyvinyl ether.

As examples of the oxetane compound according to the present invention, 3' - (oxybismethylene) bis (3-ethyl) oxetane (GR-OXT-03), 3-ethyl-3-oxetanemethanol, bis [ (3-methyl-3-oxetanylmethoxy) methyl ] ether, bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] ether, 1, 4-bis [ (3-methyl-3-oxetanylmethoxy) methyl ] benzene, 1, 4-bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] benzene, 3-methyl-3-oxetanyl) methyl acrylate, 3-ethyl-3-oxetanyl) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate, 3-methyl-3-vinylhydroxymethyloxetane, 3-methyl-3-ethylenehydroxypolyethoxylated methyloxetane, 1, 4-bis (3-ethyl-3-oxetanylmethoxy) butane, 1, 6-bis (3-ethyl-3-oxetanylmethoxy) hexane, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane, 1, 3-bis [ (3-ethyl-3-oxetanylmethoxy) methyl ] propane Alkyl, polyethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, tricyclodecanediyldimethylene (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, 3-oxiranyl 7-oxabicyclo [4.1.0] heptane, and 3-ethyl-3-oxetanemethanol (GR-OXT-01), 3-ethyl-3-chloromethyloxetane (GR-OXT-02) produced by solid wetting technology, One or a combination of two or more of 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane (GR-OXT-04), 3' - ((((propane-2, 2-diylbis (4, 1-phenylene)) bis (oxy)) bis (methylene)) bis (3-ethyloxetane) (GR-OXT-05), 3-ethyl-3- (phenylmethoxymethyl) oxetane (GR-OXT-06), oxetane methacrylate (GR-OXT-09), bis [ (3-ethyloxetan-3-yl) methyl ] benzene-1, 4-dicarboxylate (GR-OXT-11) and the like, and polyfunctional oxetane compounds such as oligomers or copolymers thereof, and etherates of oxetanol and hydroxyl group-containing resins such as novolak resins, poly (p-hydroxystyrene), Cardo-type bisphenols, calixarenes, and silsesquioxanes. In addition, compounds having both oxetane and alkyl (meth) acrylate structures can be exemplified.

According to the present invention, the amount of the cationically polymerizable compound as component (a2) may be from 5 to 80% by weight, for example from 10% by weight, from 20% by weight, from 30% by weight, from 40% by weight, from 50% by weight, from 60% by weight, from 70% by weight, preferably from 10 to 60% by weight, based on the total weight of the photocurable composition.

According to the present invention, the amount of the photopolymerizable compound as the component (a) therein may be 50 to 99 wt%, such as 60 wt%, 70 wt%, 80 wt%, 90 wt%, 95 wt%, preferably 60 to 95 wt%, based on the total weight of the curable composition.

According to a preferred embodiment of the present invention, wherein the weight ratio of component (a1) to component (a2) may be from 1:10 to 20:1, preferably from 1:5 to 10: 1.

Other cationically polymerizable compound

According to an embodiment of the present invention, the photocurable composition comprises at least one other cationically polymerizable compound than component (a 2).

The other cationic polymer compound may be in the form of a monomer or a resin (such as an oligomer or prepolymer). According to an embodiment of the present invention, the other cationically polymerizable compound may be selected from ethylene oxide compounds and aziridine compounds.

The oxirane compound may be selected from, for example, glycidyl ether epoxy compounds, glycidyl ester epoxy compounds, glycidyl amine epoxy compounds, aliphatic epoxy compounds, alicyclic epoxy compounds, and the like. The oxirane compound may be in the form of a monomer or a resin (e.g., an oligomer or a prepolymer). There may also be mentioned compounds having both an ethylene oxide group and a radical polymerizable group (such as an acrylate group), such as epoxy (meth) acrylate resins. Glycidyl ether type epoxy compounds (particularly aliphatic glycidyl ether type epoxy compounds, bisphenol a type glycidyl ether type epoxy compounds) and aliphatic epoxy resins are preferable. Further, a compound having both an ethylene oxide group (e.g., a cycloaliphatic ethylene oxide group or a glycidyl ether group) and an alkyl (meth) acrylate structure is preferable.

As examples of these oxirane compounds, mention may be made of 3, 4-epoxycyclohexylmethyl-3, 4-epoxycyclohexanecarboxylate (ERL-4211), bis (3, 4-epoxycyclohexylmethyl) adipate (UVR-6128), trimethylolpropane glycidyl ether (TPEG), 1, 2-epoxy-4-vinylcyclohexane, methyl 3, 4-epoxycyclohexanecarboxylate, diglycidyl 4, 5-epoxycyclohexane-1, 2-dicarboxylate, diglycidyl tetrahydrophthalate, diglycidyl hexahydrophthalate, bisphenol A diglycidyl ether (E-03 type), 3-oxiranyl 7-oxabicyclo [4,1,0]Heptane, ethylene glycol diglycidyl ether, C₁₂-C₁₄Polyfunctional epoxy compounds such as alkyl glycidyl ether, polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polyether polyol glycidyl ether, glycidyl methacrylate, trimethylol triglycidyl ether, 1, 4-butanediol diglycidyl ether, and oligomers or copolymers thereof, and EPIKOTE Resin 862, EPIKOTE Resin827, EPIKOTE Resin 869, EPIKOTE Resin 320, EPIKOTE Resin 816, EPIKOTE Resin 232, EPIKOTE Resin 144, and the like. These compounds may be used in one or more kinds.

In the present invention, as the aziridine monomer, trimethylolpropane-tri- β -aziridinylpropionate, tetramethylolmethane-tri- β -aziridinylpropionate, or N, N-hexamethylene-1, 6-bis-1-aziridinecarboxamide, etc. may be mentioned.

The amount of the other cationically polymerizable monomer may be 5 to 50% by weight, for example, 10% by weight, 25% by weight, 30% by weight, 40% by weight, 50% by weight, preferably 10 to 40% by weight, based on the total weight of the photocurable composition.

In a preferred embodiment, the polymethine cyanine compound as component (b) is selected from polymethine cyanine compounds having the structure of formula (I):

Y⁺and the heterocyclic ring in the definition of Y may carry 1 or more groups selected from halogen, CN, nitro, C₁-C₁₂Branched or unbranched alkyl, C₁-C₁₂Branched or unbranched alkoxy radical, C₁-C₁₂A substituent of a branched or unbranched alkylthio group or a phenylthio group, wherein said C₁-C₁₂Branched or unbranched alkyl, said C₁-C₁₂Branched or unbranched alkoxy radical, said C₁-C₁₂The alkyl groups in a branched or unbranched alkylthio group may be interrupted by 1 or more non-adjacent oxygen atoms;

preferably Y⁺Each of Y is a junction shown belowA structural unit:

indole salts/indoles

Phenyl [ e ]]Indole salts/phenyl [ e ]]Indoles

more preferably Y⁺and/Y is a structural unit shown as follows respectively:

and/or

n₁，n₂independently 0, 1 or 2; preferably 0 or 1, more preferably 1;

a is selected from the structures shown as A-1 to A-13:

or C₁-C₁₂A branched or unbranched alkoxy group (A-13);

wherein

Denotes the attachment site to the structure of formula (I),

wherein, R₂And R₂The "radicals, which are identical or different, are each independently selected from hydrogen, halogen, C₁-C₆Branched or unbranched alkyl, C₁-C₆Branched or unbranched alkoxy radical, C₁-C₆A branched or unbranched alkylthio group or a phenylthio group,

when the A group is a group A-1 or A-2, n₃Is 0, when the A group is a group A3-A13, n₃The number of the carbon atoms is1,

and X^-Represents a counter ion.

In one embodiment, R₁Is selected from C₁-C₆Branched or unbranched alkyl and C₁-C₆A branched or unbranched alkoxy group, wherein said C₁-C₆Branched or unbranched alkyl and C₁-C₆The branched or unbranched alkoxy groups may be separated by 1 or 2 non-adjacent oxygen atoms.

In one embodiment, R₂Selected from H, halogen, nitro, C₁-C₆Branched or unbranched alkyl and C₁-C₆A branched or unbranched alkoxy group, wherein said C₁-C₆Branched or unbranched alkyl, said C₁-C₆The branched or unbranched alkoxy groups may be interrupted by 1 or 2 non-adjacent oxygen atoms, more preferably R2 is selected from H, halogen, nitro and C₁-C₆A branched or unbranched alkoxy group, wherein said C₁-C₆The branched or unbranched alkoxy groups may be separated by 1 non-adjacent oxygen atom.

In one embodiment, R₃Selected from H, C₁-C₆Branched or unbranched alkyl and C₁-C₆A branched or unbranched alkoxy group, wherein said C₁-C₆Branched or unbranched alkyl and said C₁-C₆The branched or unbranched alkoxy groups may be separated by 1 or 2 non-adjacent oxygen atomsMore preferably R₃Selected from H and C₁-C₆Branched or unbranched alkoxy groups.

In one embodiment, B and C are independently H or together with the carbon atom connecting them form a five or six membered ring. In a preferred embodiment, the five-or six-membered ring carries only one carbon-carbon unsaturated double bond.

In one embodiment, "R" is₂And R₂The "radicals are identical or different and are each independently selected from hydrogen or C₁-C₆Branched or unbranched alkyl, preferably hydrogen or C₁-C₆Branched or unbranched alkyl, more preferably hydrogen.

In one embodiment, X^-Represents a counterion selected from one of the following groups: BF (BF) generator₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、[PF₃(C₂F₅)₃]^-、[Al(OC(CF₃)₃)₄]^-、[B(PhF₅)₄]^-、[B(Ph(CF₃)₂)₄]^-、[((CF₃)₂SO₂)₂N]^-、[((CF₃)₂SO₂)₃C]^-、Cl^-、Br^-、F^-、[Al(O-t-C₄F₉)₄]^-、[Al(O-(i-C₃F₇)CH₃)₄]^-、[C(O-SO₂CF₃)₃]^-、[n-C₁₂H₂₅-TsO]^-Or [ NTf₂]^-，

Among them, BF is preferred₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、[PF₃(C₂F₅)₃]^-、[Al(OC(CF₃)₃)₄]^-、[B(PhF₅)₄]^-、[B(Ph(CF₃)₂)₄]^-、[((CF₃)₂SO₂)₂N]^-、[((CF₃)₂SO₂)₃C]^-、[Al(O-t-C₄F₉)₄]^-、[Al(O-(i-C₃F₇)CH₃)₄]^-Or [ NTf₂]^-，

More preferably [ PF₃(C₂F₅)₃]^-、[Al(OC(CF₃)₃)₄]^-、[B(PhF₅)₄]^-、[B(Ph(CF₃)₂)₄]^-、[((CF₃)₂SO₂)₂N]^-、[((CF₃)₂SO₂)₃C]^-、[Al(O-t-C₄F₉)₄]^-Or [ Al (O- (i-C) ]₃F₇)CH₃)₄]^-，

Most preferably [ Al (O-t-C)₄F₉)₄]^-Or [ PF ]₃(C₂F₅)₃]^-。

In the compounds of formula (I), when the A group is A-1 or A-2 and Y is⁺And R in Y₁Is C₁-C₁₂Branched or unbranched alkyl or C₁-C₁₂When the alkoxy group is branched or unbranched, the moiety of formula (I) is entirely uncharged, X is absent, and when R is²When the group is a group A-3 to A-13, the moiety of formula (I-1) is overall positively charged:

wherein Y is⁺、Y、A、B、C、n₁、n₂As defined above.

In the compounds of formula (I), when A is selected from A1 or A2, X is absent, i.e. n₃Is 0.

When A is selected from A-3 to A-13, the moiety of formula (I-1) bears a positive charge on the whole, X^-As defined above, n₃Is 1.

In bookIn the present invention, the polymethine cyanine compound of formula (I) comprises a structural moiety of formula (I-1) and, if present, a counter ion X^-。

In the polymethine cyanine compound of the formula (I) of the present invention and the structural moiety of the formula (I-1) contained therein, n₁、n₂Independently is 0, 1 or 2, n₃Independently 0 or 1. B and C independently represent H and C₁-C₁₂Alkyl groups either together with the carbon atoms connecting them form a five-or six-membered ring. When n is₁、n₂Are all 0, the compound of formula (I) is a trimethyl compound, when n is₁Is 0, n₂Is1, the compound of formula (I) is a pentamethine compound, when n is₁，n₂When 1, the compound of formula (I) is a heptamethine compound, when n₁，n₂Is1, and B, C form a five-membered ring together with the carbon atom connecting them, or a six-membered ring, the compound of formula (I) is a heptamethine compound containing a five-membered ring or a six-membered ring in the middle position. In a preferred embodiment of the invention, the compound of formula (I) is a trimethyl compound, wherein n is₁、n₂Are all 0. In another preferred embodiment of the invention, the compound of formula (I) is a pentamethine compound, wherein n is₁Is 0, n₂Is 1. In a further preferred embodiment of the invention, the compound of formula (I) is B, C heptamethine compounds forming a five-membered ring together with the carbon atom to which they are attached, wherein n₁，n₂Is 1.

In the polymethine cyanine compound of the formula (I) of the present invention, (X)^-)_n3If present, it represents a counterion to the structural moiety of formula (I-1), which, depending on the type of A group, is either not present at all or is anionic.

When the structural moiety of the formula (I-1) is entirely uncharged, n₃Is 0, i.e. the compound of formula (I) is free of any counter ion.

In one embodiment of the invention, in the formula (I) of the invention(I) Polymethine cyanine compounds and structural parts thereof comprising of formula (I-1), Y⁺And Y each comprise a nitrogen-containing heterocycle, Y⁺The difference from the structure of Y is that Y⁺The nitrogen containing ring atoms have a positive charge and Y does not exhibit any charge.

Advantageously, the A group is A-4, A-5 or A-7 to A-13, more preferably A-4, A-5, A-7, A-8, A-11, A-12 or A-13.

Preferred cyanine dyes can be classified into four groups: the following S-1, S-2, S-3 and S-4:

a, R therein₁、R₂，R₃M and X^-As defined above.

In an advantageous embodiment of the present invention, the polymethine cyanine compound as component (b) is one or more selected from the group consisting of compounds S1-S70 below. These compounds are sometimes also referred to as infrared sensitive dyes S1-S70.

The compounds of formula (I) of the present invention are known per se, for example, from jp 2010-209191 a, or can be prepared by conventional methods in the art.

According to the invention, the amount of infrared absorbing photosensitizer as component (b) may be from 0.1 to 10 wt. -%, for example 0.2 wt. -%, 0.5 wt. -%, 0.8 wt. -%, 1 wt. -%, 2 wt. -%, 3 wt. -%, 4 wt. -%, 5 wt. -%, 6 wt. -%, 7 wt. -%, 8 wt. -%, 9 wt. -%, preferably 0.5 to 5 wt. -%, based on the total weight of the photocurable composition.

A component (c): photopolymerization initiator

According to an embodiment of the present invention, the photopolymerization initiator as the component (c) may be a photopolymerization initiator capable of generating radicals and cations in the presence of the component (b). Preferably, the photopolymerization initiator as the component (c) is selected from the group consisting of a photopolymerization initiator of an iodonium salt compound, a sulfonium salt compound, a triazine compound and an oxime ester compound, and is preferably an iodonium salt compound.

As the iodonium salt compound suitable for the present invention, an iodonium salt compound of the formula (II) is preferably included

Wherein R is₁’-R₆' may be the same or different and are independently selected from H, halogen, nitro, C₁-C₂₀Branched or unbranched alkyl, C₁-C₂₀Branched or unbranched alkoxy and C₁-C₂₀A branched or unbranched alkylthio group, and X'^-As above for X in the compound of formula (I)^-As defined. In one embodiment, R₁’-R₆' may be the same or different and are independently selected from H, C₁-C₁₂Branched or unbranched alkyl, C₁-C₁₂Branched or unbranched alkoxy and C₁-C₁₂Branched or unbranched alkylthio. In a preferred embodiment, X in the compound of formula (I)^-And X 'in the compound of formula (II)'^-Are the same.

The iodonium salts of formula (II) of the present invention are known per se and can be prepared by conventional methods in the art.

In an advantageous embodiment of the invention, the iodonium salt initiator of formula (II) IS one or more selected from the following compounds IS1-IS 40:

wherein the amount of the photopolymerization initiator as component (c) may be 0.1 to 10% by weight, for example 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, preferably 0.5 to 5% by weight, based on the total weight of the photocurable composition. Wherein the endpoints of the ranges and specific values recited are arbitrarily combined in a range.

In the initiator system used according to the invention, the weight ratio of infrared-absorbing photosensitizer as component (b) to photopolymerization initiator as component (c) may be from 50:1 to 1:50, such as 45:1,40:1,30:1,20:1,15:1,10:1, 8:1,6:1, 5:1,4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:8, 1:10, 1:15, 1:20, 1:30, 1:40, 1:45, preferably 10:1 to 1:10, more preferably 5:1 to 1: 5. The endpoints and specific values of the ranges disclosed herein for the relevant characteristic may be combined with each other in a new range.

According to one aspect of the present invention, there is provided a photosensitive ink comprising the photocurable composition of the present invention.

Coloring agent

The photosensitive ink of the present invention may contain at least one colorant such as white, blue, green, violet, yellow, red and black colorants and the like. This is that the colorant may be a pigment or a dye.

Such colorants may be used alone or in a mixture of two or more. The amount of colorant can be from 0.1 to 50 parts by weight, such as 0.5, 1,10, 15, 20, 25, 30, or 40 parts by weight, based on 100 parts by weight of the non-volatile components of the photosensitive ink.

As the white pigment, there may be mentioned titanium oxide, zinc oxide, magnesium oxide, zirconium oxide, aluminum oxide, barium sulfate, silica, talc, mica, aluminum hydroxide, calcium silicate, aluminum silicate, hollow resin particles, zinc sulfide and the like. Among them, titanium oxide is preferable from the viewpoint of high coloring property and reflectance. These white pigments may be used alone in 1 kind, or may be used in combination in 2 or more kinds. The titanium oxide may be rutile type titanium oxide or anatase type titanium oxide, and rutile type titanium oxide is preferably used in view of coloring property, concealing property and stability. Anatase-type titanium oxide, which is the same titanium oxide, has a higher whiteness than rutile-type titanium oxide, and is often used as a white pigment. The whiteness of rutile titanium oxide is slightly inferior to that of anatase titanium oxide.

The amount of the white colorant to be compounded has a large influence on the absorbance, and is usually 5 to 50 parts by weight, more preferably 20 to 30 parts by weight, based on 100 parts by weight of the nonvolatile components of the photocurable ink.

As black colorants, carbon, nigrosine, iron oxide, and the like can be mentioned. The amount of black colorant has a large influence on the absorbance. The amount thereof is usually 5 to 50 parts by weight, preferably 20 to 30 parts by weight, based on 100 parts by weight of the nonvolatile components of the photosensitive ink.

As the blue colorant, phthalocyanine blue and the like can be mentioned.

As the green colorant, phthalocyanine green, iodine green, and the like can be mentioned.

As violet colorant may be mentioned crystal violet.

As yellow dye disazo yellow may be mentioned.

Dispersing agent

The photosensitive ink of the present invention may contain a wetting dispersant. As the wetting dispersant, a substance generally having an effect of assisting dispersion of a pigment can be used. As such a wetting dispersant, there can be used: examples of the polymer compound include compounds having a polar group such as a carboxyl group, a hydroxyl group, and an acid ester, acid-containing compounds such as phosphate esters, acid group-containing copolymers, hydroxyl group-containing polycarboxylates, polysiloxanes, and salts of long-chain polyaminoamides and acid esters. Among these wet dispersants, those having an acid value are preferable because they are effective for dispersing inorganic pigments such as titanium oxide.

Other Components

The photosensitive ink may contain an amine compound and a plasticizer as required; fillers, antifoaming agents, flame retardants, stabilizers, adhesion imparting agents, leveling agents, peeling promoters, antioxidants, perfumes, image forming agents, thermal crosslinking agents, and the like. These other components may be used alone or in combination of two or more.

In the case where the above-mentioned photosensitive ink contains these other components, the amount thereof is usually 0.01 to 30 parts by weight relative to 100 parts by weight of the nonvolatile components of the photosensitive ink.

The photosensitive ink of the present invention is generally applied by an ink jet method.

The viscosity of the photosensitive ink at 50 ℃ is usually less than 20 mPas. However, the viscosity of the photosensitive ink at 50 ℃ is usually more than 5 mPas.

The invention also relates to the use of the photosensitive composition and the photosensitive ink of the invention in the preparation of printed circuit boards. According to the present invention, the photosensitive ink of the present invention is used for forming a resist, a solder resist and/or a symbol mark on a printed wiring board, preferably by an ink-jet method.

The present invention also relates to a printed wiring board obtainable from the photocurable composition or photosensitive ink of the present invention.

Examples

The present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples. In the following, unless otherwise specified, "part" means part by weight.

This example is an infrared curable ink-jet printing ink consisting essentially of the following components: a photopolymerizable compound A, an infrared absorbing photosensitizer B, a photopolymerization initiator C, an auxiliary D and a colorant E.

The preparation method of the infrared light curing ink-jet printing ink comprises the following steps:

in a dust-free laboratory, raw materials are uniformly mixed according to a formula ratio, a stirrer is used for stirring for 3 hours at a proper rotating speed, the uniformly stirred raw material slurry is ground by a ball mill or a sand mill at a rotating speed of 900rpm for 2 hours, the average particle size is detected to be between 100 and 200nm by a laser particle sizer, and then the ink is obtained by filtering by a filter.

The present invention will be described in further detail with reference to specific examples and comparative examples.

Examples 1 to 77 and comparative examples 1 to 3

Infrared ray-curable ink jet printing inks according to the above-mentioned preparation methods, ink jet printing inks of examples 1 to 77 and comparative examples 1 to 3 were prepared respectively in accordance with the components and compounding ratios shown in tables 1 to 8 below.

Table 1 formula table of infrared light curing ink-jet printing ink

Table 2 formula table of infrared light curing ink-jet printing ink

Table 3 formula table of infrared light curing ink-jet printing ink

Table 4 formula table of infrared light curing ink-jet printing ink

Table 5 formula table of infrared light curing ink-jet printing ink

Table 6 formula of infrared light curing ink-jet printing ink

Table 7 formula table of infrared light curing ink-jet printing ink

Table 8 formulation table of infrared light-curable ink-jet printing ink and light-curable ink of comparative example

Details of each component shown in the above table are as follows.

(A) The components are as follows: photopolymerizable compound

A1: a radical polymerizable compound, 1, 9-nonanediol diacrylate (A-NOD-N, a product of Mizhongcun chemical industries, Ltd.)

A2: a radical polymerizable compound, trimethylolpropane triacrylate (TMPTA, manufactured by Kyoho Kazu Ruiyang chemical Co., Ltd.)

A3: a cationically polymerizable compound, 3,3' - (oxybismethylene) bis (3-ethyl) oxetane (OXT-3, manufactured by Hubei Gurun science and technology Co., Ltd.)

A4: bisphenol A type epoxy resin containing (meth) acryloyl group (made by Xinzhongcun chemical industry Co., Ltd., EA-1010N) (monofunctional)

(B) The components are as follows: infrared absorbing photosensitizers

In the examples, the infrared absorbing photosensitizer as component (B) is one or more of the compounds S1-S70, numbered as described above in the specification. These compounds are known from japanese patent application laid-open No. 2010-209191, or can be prepared by a conventional method in the art.

(C) The components are as follows: photopolymerization initiator

In the examples, component (C) comprises an iodonium salt compound of formula (II) which IS one or more of compounds IS1-IS40, numbered as described in the specification above. These compounds can be prepared by conventional methods in the art.

In the comparative examples, the component (C) further included ITX (2-isopropylthioxanthone, available from Hubei Gurung science and technology Co., Ltd.), 907 (2-methyl-1- (4-methylthiophenyl) -2-morpholin-1-one, available from Changzhou Strong New materials Co., Ltd.), 819 (phenylbis (2,4, 6-trimethylbenzoyl) phosphine oxide, available from Changzhou Strong New materials Co., Ltd.).

Other components:

(D) the components are as follows: auxiliary agent

D1: silicone modified defoaming agent (BYK, product name BYK-067)

D2: dispersion auxiliary agent (BYK product, trade name BYK-9076)

(E) The components are as follows: coloring agent

E1: phthalocyanine Blue (fastgen Blue-5380);

e2: cromophtal yellow (Y-AGR).

Basic performance tests of viscosity, particle size and surface tension:

the basic properties such as viscosity, particle diameter, surface tension, etc. were measured for the ink-jet printing inks of examples 1 to 77 and comparative examples 1 to 3 prepared as described above, and the measurement methods are shown below, and the results are shown in Table 9.

(1) Viscosity of the oil

The viscosities of the photosensitive inks obtained in examples 1 to 77 and comparative examples 1 to 3 were measured at a temperature of 50 ℃ and at 100rpm by an SNB-1 viscometer.

The test evaluation criteria are as follows:

●: the viscosity of the ink is less than 20mPa & s;

x: the viscosity of the ink is more than 20 mPas.

(2) Particle size

The ink particle diameters of examples 1 to 77 and comparative examples 1 to 3 were measured with a laser particle sizer LT3600 under normal temperature conditions.

The test evaluation criteria are as follows:

●: the average grain diameter of the ink is less than 300 nm;

x: the average grain diameter of the ink is more than 300 nm.

(3) Surface tension

The inks of examples 1 to 77 and comparative examples 1 to 3 were tested for surface tension under ambient conditions using a surface tension meter BYZ-2.

The test evaluation criteria are as follows:

●: the surface tension of the ink is between 20 and 30 mN/m;

x: the ink surface tension is more than 30mN/m or less than 20 mN/m.

TABLE 9 ink jet printing ink base Performance test of examples 1-77, comparative examples 1-3

As can be seen from the test results in Table 9, the ink compositions prepared in examples 1-77 all meet the basic performance requirements for ink jet printing.

Printing performance test

Ink for ink jet printing of circuit boards is required to have excellent properties such as good adhesion, insulation reliability, heat resistance, acid and alkali resistance, and solvent resistance. The ink-jet printing inks of examples 1 to 77 and comparative examples 1 to 3 prepared as described above were injected into ink bags of an ink-jet printer, the head temperature was set to 40 to 60 ℃, the copper-clad laminate was used as a substrate, and the ink-jet printing was carried out by starting the spray mode program, except that the inks of examples 1 to 77 each had a wavelength of 808nm and an exposure energy of 2J/cm²The infrared LED curing device. Comparative examples 1 to 3 used a wavelength of 395nm and an exposure energy of 300mJ/cm²The ultraviolet LED curing device. The comparative example was cured by heating at 150 ℃ for 10 minutes after the light irradiation. By the heating, curing can be sufficiently performed.

The samples were prepared and the ink coatings were evaluated for their performance, as described below, and the results are given in table 10:

(1) finger touch dryness test

The ink coating obtained immediately after the ink jet printing was touched with a finger, and then the degree of drying and the surface condition thereof were visually observed.

The finger-touch dryness test criteria are as follows:

●: the ink coating is completely free of indentation, and the formed film is smooth and has no fingerprint trace;

x: the ink coating has obvious indentation and obvious fingerprint trace.

(2) Adhesion test

Placing the sample plate in a drying oven at 150 ℃ for baking for 1h, testing the adhesive force of the sample plate by adopting a check method, cutting the ink-jet ink coating to the surface of the base material by using a cutting tool to form grid-shaped scratches, sticking and tearing by using a 3M adhesive tape, observing the shedding condition of the coating, and then evaluating the adhesion condition of the coating.

The adhesion evaluation criteria were as follows:

●: the adhesive force is high, and no coating is peeled off;

a tangle-solidup: the adhesive force is general, and the corner falls slightly but does not fall off in flakes;

x: the adhesion was poor and the coating peeled off significantly.

(3) Pencil hardness test

The pencil hardness tester ACE-B3084 is placed on the board to be tested and advanced at a speed of about 1cm per second with a force (either to break the lead edges or to plow the coating film). Starting from the hardest pencil, each grade of pencil plows five traces with the length of 5cm until a pencil which does not plow the coating film is found, and the hardness of the pencil represents the hardness of the pencil of the measured coating film.

The pencil hardness test evaluation criteria are as follows:

●: the pencil hardness test reaches or exceeds the 3H standard;

x: the pencil hardness test is less than 2H standard.

(4) Solder thermal shock resistance test

And spraying the soldering flux on the test sample, then soaking in molten solder at 260 ℃ for 10s, taking out and carrying out visual detection.

The evaluation criteria for the solder thermal shock resistance were as follows:

●: the solder heat shock resistance process has no change, no color change, no falling off and no bump;

a tangle-solidup: slight change occurs in the process of resisting soldering tin thermal shock, and slight color change, falling off and bulging occur;

x: the solder heat shock resistance process is changed, such as discoloration, falling, bulging and the like.

(5) Insulation reliability test

The sample was placed in a constant temperature and humidity chamber of 90% r.h. for one week under a bias voltage of DC 100V applied to the sample and temperature cycling of 25-65 ℃. Then treated at room temperature at DC 500V for one minute, resistance measurement was performed with a multimeter, and observation was performed under an optical microscope.

The insulation reliability test evaluation criteria are as follows:

●: the insulation resistance value is almost not reduced, and surface change is not observed completely;

x: the insulation resistance value is obviously reduced, and a large amount of copper ions are migrated.

(6) Acid resistance test

The test panels were soaked in 10% volume fraction H at room temperature₂SO₄And (4) keeping the mixture in the aqueous solution for half an hour, taking out the mixture, washing the mixture with deionized water, air-drying the mixture, and visually detecting the mixture.

The acid resistance evaluation criteria are as follows:

●: no change, no color change, no falling off and no protrusion;

x: changes occur, such as discoloration, peeling, bulging, etc.

(7) Alkali resistance test

And soaking the test sample in 10% NaOH aqueous solution for half an hour at room temperature, taking out, washing with deionized water, air-drying, and visually detecting.

The alkali resistance evaluation criteria are as follows:

●: no change, no color change, no falling off and no protrusion;

x: changes occur, such as discoloration, peeling, bulging, etc.

(8) Solvent resistance test

The test panels were immersed in PMA (propylene glycol methyl ether acetate) solution for half an hour at room temperature, taken out, washed with deionized water, air dried, and visually inspected.

The evaluation criteria for solvent resistance were as follows:

●: no change, no color change, no falling off and no protrusion;

x: changes occur, such as discoloration, peeling, bulging, etc.

(9) Adhesion test

The curable composition was applied to a copper foil with a thickness of 40 μm by an ink jet coating apparatus and cured by an infrared apparatus. Then, the resultant was subjected to heat treatment in a hot air circulation type drying furnace at 150 ℃ for 60 min. The thus obtained sample was subjected to a cross-cut tape peeling test and evaluated according to the following criteria.

●: no peeling.

And (delta): there was little peeling.

X: there was peeling.

(10) Pattern bleed test

The pattern formed by inkjet printing was observed and measured by an optical microscope for the width of bleeding occurring on the base substrate side from the boundary line between the cured coating film and the copper foil of the base substrate, and evaluated according to the following criteria. As the base substrate, a copper-clad laminate for a printed wiring board (FR-4, 150 mm. times.95 mm. times.1.6 mm) was used.

●: the width of the ink penetration is 0-10 μm

O: the width of the ink penetration is 11-20 μm

And (delta): the width of the ink penetration is 21-30 μm

X: the width of the ink bleed exceeds 30 μm

TABLE 10 evaluation results of Properties of Infrared-curable ink-jet printing inks of examples 1 to 77 and photocurable inks of comparative examples 1 to 3

And (4) conclusion: as can be seen from the test results in Table 10, the properties of examples 1 to 77 according to the present invention are all the best. On the other hand, comparative example 1, which employs a radical polymerization system of ultraviolet curing, is inferior in surface curability, adhesion, solder thermal shock resistance, pattern bleeding, and adhesion; for comparative example 2 of the cationic polymerization system using ultraviolet curing, the adhesion, solder thermal shock resistance, pattern bleeding, and adhesion were poor; in comparative example 3 using a radical-cation hybrid system of ultraviolet curing, the surface curing property, pattern bleeding, and adhesion were poor. The photosensitive ink-jet printing ink obtained by using the photocurable composition of the infrared light-sensitive free radical-cation hybrid system for the PCB has the characteristics of excellent curing performance, oxygen resistance, high adhesion, small shrinkage, higher light sensitivity, steeper imaging side wall and the like compared with a single ultraviolet light-sensitive free radical polymerization system or an ultraviolet light-sensitive cation polymerization system and an ultraviolet light-sensitive free radical-cation hybrid system.

Example 78: reaction of vinyl ether monomer and methacrylate monomer in the presence of free radical photoinitiator

The high-efficiency free radical photoinitiator bis (2,4, 6-trimethylbenzoyl) phenylphosphine oxide (trade name 819) is adopted as the free radical photoinitiator, and a 395nm UV-LED light source (light intensity of 100 mW/cm) is adopted²) The initiation effect of 819 on acrylate free radical polymerizable monomer TPGDA and 4-hydroxybutyl vinyl ether monomer (HBVE) is tested by adopting a Photo-DSC test method. The experimental results are shown in figure 1 (of sample heat flow versus exposure time)A relational graph). The experimental result shows that the light intensity is 100mW/cm²When 819 is adopted to initiate TPGDA polymerization under a 395nm UV-LED light source, the heat flow curve of the sample is obviously changed, which is caused by the fact that the double bond of TPGDA is subjected to crosslinking reaction to release heat, and when 819 has undergone HBVE polymerization, the heat flow of the sample is hardly changed, which indicates that no free radical polymerization reaction occurs in HBVE. It can thus be demonstrated that HBVE is a cationically polymerizable monomer, what happens in this disclosure is cationic polymerization rather than free radical polymerization.

Example 79: the initiator system was tested for its initiating effect in different monomers:

in the embodiment, the real-time infrared test method IS adopted to compare the polymerization effects of the vinyl ether monomer HBVE, the oxetane monomer GR-OXT-04 and the epoxy monomer ERL-4211 in a photoinitiation system S2/IS 2. The samples were prepared as follows: 1 part by weight of polymethine cyanine S2 and 5 parts by weight of iodonium salt IS2 were dissolved in 94 parts by weight of HBVE, 1 part by weight of polymethine cyanine S2 and 5 parts by weight of iodonium salt IS2 were dissolved in 94 parts by weight of GR-OXT-04, and 1 part by weight of polymethine cyanine S2 and 5 parts by weight of iodonium salt IS2 were dissolved in 94 parts by weight of ERL-4211. The samples were coated on the sample data acquisition area of the infrared spectrometer ATR mode, with a 20 μm film thickness (in this example, a lower film thickness was used for better observation of the differences in polymerization of the different monomers), and covered with a glass slide to reduce oxygen interference. Then the light intensity is 1.2W/cm²The sample is irradiated by the 805nm NIR-LED light source, so that the sample is subjected to photopolymerization. Collecting infrared absorption peak of monomer in real time by using infrared spectrometer, and then measuring the infrared absorption peak at 975cm according to ERL-4211^-1The change in peak area was calculated as the cure rate at different exposure times according to GR-OXT-04 at 830cm^-1The peak area of the (D) resin was calculated to determine the curing rate at different exposure times according to HBVE at 1650cm^-1The change in peak area at (a) was calculated for its cure rate at different times. The results are shown in FIG. 2 (graph of different monomer curing rates versus exposure time). As can be seen from FIG. 2, the infrared composite initiation system S2/IS2 has excellent initiation effects on vinyl ether monomers and oxetane monomers. Compared with an epoxy monomer ER-4211The vinyl ether monomer HBVE and the oxetane monomer GR-OXT-04 not only have high curing rate, but also reach the maximum curing rate in a short exposure time, which indicates that the reaction rate is very high.

The initiator system used in the present invention has a very good initiating effect on vinyl ether-based monomers and oxetanes.

Claims

(a) a photopolymerizable compound which is capable of forming a film,

(b) at least one infrared-absorbing photosensitizer,

(c) at least one kind of photopolymerization initiator,

2. The photocurable composition for printed circuit boards according to claim 1, wherein the radically polymerizable compound as component (a1) is an ethylenically unsaturated group-containing radically polymerizable compound, preferably a monofunctional compound, a difunctional compound, a trifunctional or higher functional compound, and mixtures thereof, such as a mixture of a difunctional compound and a trifunctional compound.

3. The photocurable composition for printed circuit boards according to claim 1 or 2, wherein the radically polymerizable compound as component (a1) is selected from at least one of radically polymerizable resins, 2-functional or more radically polymerizable monomers, and monofunctional radically polymerizable monomers.

4. The photocurable composition for printed circuit boards according to any one of claims 1 to 3, wherein the radical polymerizable compound as component (a1) is selected from the group consisting of (meth) acrylate compounds, (meth) acryl compounds, vinyl derivatives, styrene compounds, anhydride compounds containing an ethylenically unsaturated double bond, N-vinylpyrrolidone, N-vinylformamide, and mixtures thereof.

5. The photocurable composition for printed circuit boards according to any of claims 1 to 4, wherein the amount of the photopolymerizable compound as component (a) is from 50 to 99 wt. -%, preferably from 60 to 95 wt. -%, based on the total weight of the curable composition.

6. The photocurable composition for printed circuit boards according to any one of claims 1 to 5, wherein the weight ratio of component (a1) to component (a2) is from 1:10 to 20:1, preferably from 1:5 to 10: 1.

7. The photocurable composition for printed circuit boards according to any of claims 1 to 6, wherein the photocurable composition comprises at least one further cationically polymerizable compound different from component (a2), preferably selected from the group consisting of epoxy compounds and aziridine compounds.

8. The photocurable composition for printed circuit boards according to any one of claims 1 to 7, wherein the polymethine cyanine compound as component (b) has an absorption maximum in the range of 780nm to 2000 nm.

9. The photocurable composition for printed circuit boards according to any one of claims 1 to 8, wherein the polymethine cyanine compound as component (b) has a structure represented by formula (I):

wherein

Y⁺Represented by a bis having 8 to 18 ring members and containing 1 or 2 nitrogen atoms as ring membersCyclic, tricyclic or higher heterocyclic ring and bearing a positive charge,

preferably Y⁺and/Y is a structural unit shown as follows respectively:

indole salts/indoles

Phenyl [ e ]]Indole salts/phenyl [ e ]]Indoles

more preferably Y⁺and/Y is a structural unit shown as follows respectively:

and/or

n₁，n₂independently 0, 1 or 2; preferably 0 or 1, more preferably 1;

a is selected from the structures shown as A-1 to A-13:

or C₁-C₁₂A branched or unbranched alkoxy group (A-13);

wherein

Denotes the attachment site to the structure of formula (I),

10. The photocurable composition for printed circuit boards according to claim 9, wherein the compound of formula (I) satisfies one or more of the following conditions:

R₁is selected from C₁-C₆Branched or unbranched alkyl and C₁-C₆A branched or unbranched alkoxy group, wherein said C₁-C₆Branched or unbranchedAlkylated alkyl and C₁-C₆The branched or unbranched alkoxy groups may be separated by 1 or 2 non-adjacent oxygen atoms;

11. The photocurable composition for printed circuit boards according to claim 9 or 10, wherein X is^-Represents the following counterions: BF (BF) generator₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、[PF₃(C₂F₅)₃]^-、[Al(OC(CF₃)₃)₄]^-、[B(PhF₅)₄]^-、[B(Ph(CF₃)₂)₄]^-、[((CF₃)₂SO₂)₂N]^-、[((CF₃)₂SO₂)₃C]^-、Cl^-、Br^-、F^-、[Al(O-t-C₄F₉)₄]^-、[Al(O-(i-C₃F₇)CH₃)₄]^-、[C(O-SO₂CF₃)₃]^-、[n-C₁₂H_25-TsO]^-Or [ NTf₂]^-Among them, BF is preferred₄ ^-、PF₆ ^-、SbF₆ ^-、AsF₆ ^-、[PF₃(C₂F₅)₃]^-、[Al(OC(CF₃)₃)₄]^-、[B(PhF₅)₄]^-、[B(Ph(CF₃)₂)₄]^-、[((CF₃)₂SO₂)₂N]^-、[((CF₃)₂SO₂)₃C]^-、[Al(O-t-C₄F₉)₄]^-、[Al(O-(i-C₃F₇)CH₃)₄]^-Or [ NTf₂]^-More preferably, [ PF ]₃(C₂F₅)₃]^-、[Al(OC(CF₃)₃)₄]^-、[B(PhF₅)₄]^-、[B(Ph(CF₃)₂)₄]^-、[((CF₃)₂SO₂)₂N]^-、[((CF₃)₂SO₂)₃C]^-、[Al(O-t-C₄F₉)₄]^-Or [ Al (O- (i-C) ]₃F₇)CH₃)₄]^-Most preferably, [ Al (O-t-C)₄F₉)₄]^-Or [ PF ]₃(C₂F₅)₃]^-。

12. The photocurable composition for printed circuit boards according to any one of claims 1 to 11, wherein the infrared absorbing photosensitizer as component (b) is selected from one or more of the following compounds S1-S70:

。

13. the photocurable compound for printed circuit boards according to any one of claims 1 to 12, wherein the photopolymerization initiator as the component (c) may be a photopolymerization initiator capable of generating radicals and cations in the presence of the component (b).

14. The photocurable compound for printed circuit boards according to any one of claims 1 to 13, wherein the photopolymerization initiator as component (c) is selected from the group consisting of iodonium salt, sulfonium salt, triazine and oxime ester type photopolymerization initiators.

15. The photocurable composition for printed circuit boards according to any one of claims 1 to 14, wherein the photopolymerization initiator as component (c) is an iodonium salt, preferably selected from the group consisting of iodonium salts represented by formula II:

wherein R is₁’-R₆' may be the same or different and are independently selected from H, halogen, nitro, C₁-C₂₀Branched or unbranched alkyl, C₁-C₂₀Branched or unbranched alkoxy and C₁-C₂₀A branched or unbranched alkylthio group, and X'^-As claimed in claim 9 or 11 for X in the compound of formula (I)^-The definition of the content of the compound is as follows,

16. The photocurable composition for printed circuit boards according to any one of claims 1 to 15, wherein the photopolymerization initiator as component (c) IS selected from one or more of the following compounds IS1-IS 40:

。

17. the photocurable composition for printed circuit boards according to any one of claims 1 to 16, wherein the weight ratio of the infrared absorbing photosensitizer as component (b) to the photopolymerization initiator as component (c) is from 50:1 to 1:50, preferably from 10:1 to 10, more preferably from 5:1 to 1: 5.

18. The photocurable composition for printed circuit boards according to any of claims 1-17, wherein the amount of the infrared absorbing photosensitizer as component (b) is from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight, based on the total weight of the photocurable composition.

19. The photocurable composition for printed circuit boards according to any of claims 1-18, wherein the amount of the photopolymerization initiator as component (c) is from 0.01 to 10% by weight, preferably from 0.1 to 5% by weight, based on the total weight of the photocurable composition.

20. A photosensitive ink comprising the photocurable composition for printed circuit boards according to any one of claims 1 to 19.

21. Use of the photosensitive composition for a printed circuit board according to any one of claims 1 to 19 or the photosensitive ink according to claim 20 for producing a printed circuit board.

22. Use according to claim 21 for forming resists, solder resists and/or symbol markings on printed circuit boards, preferably by means of ink-jet.

23. A printed wiring board obtainable from the photocurable composition for printed wiring board according to any one of claims 1 to 19 or the photosensitive ink according to claim 20.