Curable composition for inkjet, electronic component, and method for producing electronic component

Abstract

The present invention provides a curable composition for ink jet, which can improve the adhesion between a substrate and a cured product and improve the resistance of the cured product to high-temperature alkali lye when the curable composition for ink jet is coated and cured. This curable composition for inkjet contains: a first (meth) acrylate compound having a plurality of (meth) acryloyl groups and an alicyclic skeleton; a second (meth) acrylate compound represented by formula (1); a photopolymerization initiator; and a colorant.

Description

Technical Field

[0001] The present invention relates to an inkjet curable composition used for coating by an inkjet method, and also to an electronic component using the inkjet curable composition and a method for producing the electronic component. Background Art

[0002] In recent years, from the viewpoint of traceability, marking portions with characters or symbols drawn on the surface of electronic components such as printed wiring boards and electrolytic capacitors are sometimes formed to record the type and manufacturing information of electronic components. Some of these marking portions are formed using a curable composition.

[0003] On the other hand, curable compositions that can be applied by inkjet are known. For example, the following Patent Document 1 discloses a curable composition for inkjet, which comprises: (A) a photopolymerizable monomer having a cyclic skeleton and a shrinkage of less than 10%, (B) a photopolymerizable bifunctional monomer having a viscosity of 100 mPa·s or less at 25° C. and a shrinkage of 10% or more and 20% or less, and (C) a photopolymerization initiator.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent document 1: WO2019 / 189157A1 Summary of the invention

[0007] Technical problem solved by the invention

[0008] When a marking portion is formed using a conventional curable composition, when the marking portion is treated with a high-temperature (e.g., 60° C.) alkali solution during the manufacturing process of the electronic component (e.g., the flux removal process, etc.), the alkali solution sometimes penetrates into the interior of the marking portion and the interface between the electronic component and the marking portion, causing the marking portion to peel off from the marking target portion.

[0009] In conventional curable compositions for forming a marking portion, when the curable composition is applied to a substrate and cured, it is difficult to improve the adhesion between the substrate and the cured product and to improve the resistance of the cured product to a high-temperature alkali solution.

[0010] Furthermore, it is not known to form a marking portion using a curable composition that can be applied by an inkjet method as a curable composition that can improve the adhesion between a substrate and a cured product and improve the resistance of the cured product to a high-temperature alkali solution.

[0011] The object of the present invention is to provide a curable composition for inkjet, which can improve the adhesion between a substrate and a cured product when the curable composition for inkjet is applied and cured, and improve the tolerance of the cured product to high-temperature alkali liquid. In addition, the object of the present invention is to provide an electronic component using the curable composition for inkjet and a method for manufacturing the electronic component.

[0012] Technical means of solving problems

[0013] The present inventors have conducted intensive studies to solve the above problems and have found a structure of a curable composition that can improve the adhesion between a substrate and a cured product and improve the resistance of the cured product to high-temperature alkali liquid and can be applied by an inkjet method.

[0014] This specification discloses the following curable composition for inkjet, electronic component, and method for producing the electronic component.

[0015] Item 1. A curable composition for inkjet, comprising:

[0016] a first (meth)acrylate compound having a plurality of (meth)acryloyl groups and an alicyclic skeleton;

[0017] A second (meth)acrylate compound represented by the following formula (1);

[0018] a photopolymerization initiator; and

[0019] Colorants,

[0020] [Chemical formula 1]

[0021]

[0022] In the above formula (1), R1 and R2 each represent a hydrogen atom or a methyl group, and R3 represents an alkylene group.

[0023] Item 2. The curable composition for inkjet according to Item 1, wherein

[0024] The colorant includes carbon black.

[0025] Item 3. The curable composition for inkjet according to Item 1 or 2, wherein

[0026] The colorant includes a copper phthalocyanine compound.

[0027] Item 4. The curable composition for inkjet according to any one of Items 1 to 3, wherein

[0028] In the above formula (1), R3 is an alkylene group having 6 to 12 carbon atoms.

[0029] Item 5. The curable composition for inkjet according to any one of Items 1 to 4, wherein

[0030] The first (meth)acrylate compound is a (meth)acrylate compound having two (meth)acryloyl groups and a dicyclopentadiene skeleton.

[0031] Item 6. The curable composition for inkjet according to any one of Items 1 to 5, comprising a urethane (meth)acrylate compound having a (meth)acryloyl group.

[0032] Item 7. The curable composition for inkjet according to Item 6, wherein

[0033] The urethane (meth)acrylate compound is a urethane (meth)acrylate compound having a plurality of (meth)acryloyl groups.

[0034] Item 8. The curable composition for inkjet according to any one of Items 1 to 7, comprising a (meth)acrylamide compound.

[0035] Item 9. The curable composition for inkjet according to any one of Items 1 to 8, which contains no solvent, or contains 1 wt % or less of a solvent in 100 wt % of the curable composition for inkjet.

[0036] Item 10. The curable composition for inkjet according to any one of Items 1 to 9, further comprising a dispersant, wherein the content of the dispersant is 25 parts by weight or more and 150 parts by weight or less relative to 100 parts by weight of the colorant.

[0037] Item 11. The curable composition for inkjet according to any one of Items 1 to 10, wherein

[0038] The content of the first (meth)acrylate compound in 100% by weight of the curable composition for inkjet is 5% by weight or more and 70% by weight or less.

[0039] Item 12. The curable composition for inkjet according to any one of Items 1 to 11, which contains no thermosetting compound, or contains 5% by weight or less of the thermosetting compound in 100% by weight of the curable composition for inkjet.

[0040] Item 13. The curable composition for inkjet according to any one of Items 1 to 12, wherein

[0041] When a cured product of the curable composition for inkjet is immersed in water at 60° C. for 1 hour and then heated at 170° C. for 1 hour, the following weight change rate is less than 5.0%.

[0042] Weight change rate (%) = |W3-W2| × 100 / W1

[0043] W1: weight of the cured product of the curable composition for inkjet before immersion;

[0044] W2: the weight of the cured product of the curable composition for inkjet after immersion and before heating;

[0045] W3: The weight of the cured product of the curable composition for inkjet after heating.

[0046] Item 14. The curable composition for inkjet according to Item 13, wherein

[0047] The weight change rate is 2.0% or less.

[0048] Item 15. The curable composition for inkjet according to any one of Items 1 to 14, wherein

[0049] The glass transition temperature of the cured product of the curable composition for inkjet is 80° C. or higher.

[0050] Item 16. The curable composition for inkjet according to any one of Items 1 to 15, which is used for forming a marking portion in an electronic component.

[0051] Item 17. An electronic component comprising an electronic component body and a marking portion disposed on a surface of the electronic component body,

[0052] The marking portion is formed using the curable composition for inkjet according to any one of items 1 to 16.

[0053] Item 18. A method for manufacturing an electronic component, comprising:

[0054] A step of applying the curable composition for inkjet described in any one of items 1 to 16 on the surface of the electronic component body using an inkjet device to form a marking layer; and

[0055] A step of curing the marking layer by irradiating light to form a marking portion.

[0056] Effects of the Invention

[0057] The curable composition for inkjet of the present invention comprises: a first (meth)acrylate compound having a plurality of (meth)acryloyl groups and an alicyclic skeleton; a second (meth)acrylate compound represented by the formula (1); a photopolymerization initiator; and a colorant. The curable composition for inkjet of the present invention has the above-mentioned structure, so when the curable composition for inkjet is applied and cured, the adhesion between the substrate and the cured product can be improved, and the tolerance of the cured product to high-temperature alkali solution can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] [ Figure 1 ] Figure 1 (a) and (b) are schematic cross-sectional views for explaining the method for manufacturing the electronic component according to the first embodiment of the present invention. DETAILED DESCRIPTION

[0059] Hereinafter, the present invention is described in detail.

[0060] (Curable composition for inkjet)

[0061] The curable composition for inkjet of the present invention (hereinafter, sometimes referred to as "curable composition") is used for inkjet coating.

[0062] The curable composition of the present invention comprises: a first (meth)acrylate compound having a plurality of (meth)acryloyl groups and an alicyclic skeleton; a second (meth)acrylate compound represented by the following formula (1); a photopolymerization initiator; and a colorant.

[0063] [Chemical formula 2]

[0064]

[0065] In the above formula (1), R1 and R2 each represent a hydrogen atom or a methyl group, and R3 represents an alkylene group.

[0066] When a marking portion is formed using a conventional curable composition, in the manufacturing process of the electronic component (e.g., flux removal process, etc.), when the marking portion is treated with a high temperature (e.g., 60° C.) alkali solution, the alkali solution penetrates through the inside of the marking portion and penetrates into the interface between the electronic component and the marking portion, and the marking portion is sometimes peeled off from the marking object portion. In the conventional curable composition for forming the marking portion, when the curable composition is applied to a substrate and cured, it is difficult to improve the adhesion between the substrate and the cured product and to improve the tolerance of the cured product to the high temperature alkali solution.

[0067] Furthermore, it is not known to form a marking portion using a curable composition that can be applied by an inkjet method as a curable composition that can improve the adhesion between a substrate and a cured product and improve the resistance of the cured product to a high-temperature alkali solution.

[0068] The inventors of the present invention have conducted in-depth research and found that by using a (meth)acrylate compound having multiple (meth)acryloyl groups and an alicyclic skeleton, it is possible to inhibit the high-temperature alkali solution from penetrating into the interior of the cured product of the curable composition and improve the tolerance of the cured product to the high-temperature alkali solution. As a reason for this, it is believed that the (meth)acrylate compound having multiple (meth)acryloyl groups and an alicyclic skeleton has a rigid molecular skeleton structure, so the glass transition temperature (Tg) is higher than the processing temperature of the alkali solution in the manufacturing process of the electronic component (for example, 60°C).

[0069] On the other hand, it is known that when the (meth)acrylate compound having multiple (meth)acryloyl groups and an alicyclic skeleton is used alone, the cured product of the curable composition becomes too hard, and the adhesion between the substrate and the cured product is sometimes insufficient. Therefore, the present inventors have found that by using the (meth)acrylate compound having multiple (meth)acryloyl groups and an alicyclic skeleton in combination with a (meth)acrylate compound represented by a specific structural formula, the adhesion between the substrate and the cured product can be improved, and the tolerance of the cured product to high-temperature alkali solution can be improved.

[0070] Furthermore, the (meth)acrylate compound represented by the specific structural formula has a low water absorption rate, and thus can suppress the absorption of high-temperature alkali liquid into the curable composition during the production process of electronic components and suppress the penetration of high-temperature alkali liquid into the cured product of the curable composition.

[0071] That is, since the curable composition of the present invention has the above-mentioned structure, when the curable composition is applied and cured, the adhesion between the substrate and the cured product can be improved, and the resistance of the cured product to high-temperature alkali liquid can be improved.

[0072] The curable composition can be applied by inkjet. When the curable composition is applied by inkjet, an inkjet device is used. The inkjet device has an inkjet head. The inkjet head has an inkjet nozzle. As for the curable composition, the curable composition applied by screen printing is different from the curable composition applied by a dispenser.

[0073] The curable composition is suitable for forming a marking portion. The curable composition is suitable for forming a marking portion, especially in electronic components. In the marking portion, display information or recorded information composed of characters or symbols is usually recorded. The marking portion preferably contains characters or symbols. The marking portion preferably contains display information or recorded information. The curable composition is suitable for use as a marking material. The curable composition is particularly suitable for use as a marking material for electronic components. In the electronic component, the marking portion is preferably formed to a thickness of 1 μm or more and 10 μm or less. The curable composition can be configured (applied) on the upper surface of the electronic component body, can be configured (applied) on the lower surface of the electronic component body, or can be configured (applied) inside the electronic component body. The marking portion can be formed on the upper surface of the electronic component body, can be formed on the lower surface of the electronic component body, or can be formed inside the electronic component body. When the marking portion is formed on the upper surface, lower surface or inside of the electronic component body, the traceability function can be imparted to the obtained electronic component.

[0074] The color of the curable composition and the marking portion may be the same as or different from the color of the marking object portion. When the color of the curable composition and the marking portion is the same as the color of the marking object portion, the traceability function can be imparted to the obtained electronic component without protruding the marking portion. When the color of the curable composition and the marking portion is different from the color of the marking object portion, the visual recognition of the marking portion can be improved.

[0075] From the viewpoint of more satisfactorily applying the curable composition by the inkjet method, the curable composition is preferably in a liquid state at 25° C. The liquid state also includes a paste state.

[0076] The viscosity (η1) of the curable composition at 25° C. is preferably 40 mPa·s or more, more preferably 60 mPa·s or more, and further preferably 80 mPa·s or more, and is preferably 500 mPa·s or less, more preferably 300 mPa·s or less, and further preferably 200 mPa·s or less. When the viscosity (η1) is above the lower limit and below the upper limit, the curable composition can be applied with a uniform thickness by inkjet, so when the curable composition is cured, the adhesion between the substrate and the cured product can be further improved.

[0077] The viscosity (η1) is measured, for example, using an E-type viscometer ("TVE22L" manufactured by Toki Sangyo Co., Ltd.) on the curable composition immediately after preparation, preferably at 25° C. and 10 rpm.

[0078] The glass transition temperature (Tg) of the cured product of the curable composition is preferably 80° C. or higher, more preferably 90° C. or higher, and further preferably 100° C. or higher, and is preferably 200° C. or lower, more preferably 190° C. or lower, and further preferably 180° C. or lower. When the glass transition temperature of the cured product of the curable composition is above the lower limit and below the upper limit, the tolerance of the cured product to high-temperature alkali liquid can be further improved (the penetration of high-temperature alkali liquid into the interior of the cured product of the curable composition can be further suppressed), and the adhesion between the substrate and the cured product can be further improved.

[0079] The glass transition temperature of the cured product of the curable composition can be measured using a dynamic viscoelasticity measuring device at a temperature increase rate of 10° C. / min and a frequency of 10 Hz. Examples of the dynamic viscoelasticity measuring device include “DVA-200” manufactured by IT Measurement & Controls Co., Ltd.

[0080] The cured product of the curable composition is obtained by, for example, the following method. The cured product of the curable composition (thickness 300 μm) is formed by repeating the following steps: applying 10 μm of the curable composition by spin coating (for example, "MS-A100" manufactured by MIKASA), and applying the curable composition at a wavelength of 365 nm with an illumination of 1000 mW / cm 2 The cumulative amount of light irradiated is 1000mJ / cm 2 The process of ultraviolet light (UV-LED).

[0081] From the viewpoint of further improving the resistance of the cured product of the curable composition to high-temperature alkali solution and further improving the adhesion between the substrate and the cured product, the following weight change rate when the cured product of the curable composition is immersed in water at 60°C for 1 hour and then heated at 170°C for 1 hour is preferably less than 5.0%.

[0082] Weight change rate (%) = |W3-W2| × 100 / W1

[0083] W1: Weight of the cured product of the curable composition before immersion

[0084] W2: Weight of the cured product of the curable composition after immersion and before heating

[0085] W3: Weight of the cured product of the curable composition after heating

[0086] The cured product of the curable composition may be a cured product of the curable composition (thickness 300 μm) used for the measurement of the glass transition temperature. The weight of the cured product of the curable composition is set to W1. The cured product of the curable composition is immersed in water at 60° C. for 1 hour, and the weight after wiping off the water droplets on the surface is set to W2. The weight of the cured product of the curable composition after immersion is heated in an oven at 170° C. for 1 hour is set to W3. The absolute value of the difference between W2 and W3 is set to |W3-W2|.

[0087] From the viewpoint of further improving the resistance of the cured product of the curable composition to high-temperature alkali solution and further improving the adhesion between the substrate and the cured product, the weight change rate is preferably less than 5.0%, more preferably less than 4.5%, further preferably less than 4.0%, and particularly preferably less than 3.0%.

[0088] From the viewpoint of further improving the tolerance of the cured product of the curable composition to high temperature alkali solution, the weight change rate is preferably 2.0% or less, more preferably 1.5% or less, further preferably 1.0% or less, and particularly preferably 0.9% or less. The lower limit of the weight change rate is not particularly limited. The weight change rate may be 0%, may be greater than 0%, or may be greater than 0.5%. It should be noted that from the viewpoint of further improving the adhesion between the substrate and the cured product, the weight change rate is preferably 2.0% or more, and preferably 2.5% or more.

[0089] When the high-temperature alkali solution penetrates into the interior of the solidified object and immerses into the interface between the substrate and the solidified object, the solidified object is sometimes peeled off from the substrate. That is, the liquid component penetrates into the interior of the solidified object, and there is a liquid component at the interface between the substrate and the solidified object, so the contact area at the interface between the substrate and the solidified object is reduced, and the solidified object becomes easy to peel off from the substrate. On the other hand, when the weight change rate is within the preferred range, the liquid component becomes difficult to penetrate into the interior of the solidified object, so the peeling caused by reducing the contact area at the interface between the substrate and the solidified object can be suppressed. In addition, when the weight change rate is within the preferred range, the tolerance of the solidified object to the high-temperature alkali solution can be further improved.

[0090] As methods for adjusting the weight change rate to be within the preferred range, the following methods can be cited. A method for adjusting the content of the first (meth)acrylate. A method for adjusting the content of the second (meth)acrylate. A method for adjusting the photocuring conditions of the curable composition (e.g., the wavelength of the irradiated light, the illuminance, and the accumulated light amount). A method for adjusting the thermal curing conditions of the curable composition (e.g., the heating temperature and the heating time).

[0091] From the viewpoint of further improving the adhesion between the substrate and the cured product by further suppressing the penetration of the liquid component into the interior of the cured product, and further improving the resistance of the cured product to high-temperature alkali liquid, in the curable composition, the glass transition temperature (Tg) of the cured product of the curable composition is 80° C. or higher, and the weight change rate is particularly preferably less than 5.0%.

[0092] Hereinafter, each component that can be used in the curable composition of the present invention is described in detail. It should be noted that in this specification, "(meth)acryloyl" means one or both of "acryloyl" and "methacryloyl", and "(meth)acrylate" means one or both of "acrylate" and "methacrylate".

[0093] <First (meth)acrylate compound having multiple (meth)acryloyl groups and an alicyclic skeleton>

[0094] The curable composition includes a first (meth)acrylate compound having a plurality of (meth)acryloyl groups and an alicyclic skeleton.

[0095] Since the curable composition includes the first (meth)acrylate compound, when the curable composition is applied and cured, the resistance of the cured product to a high-temperature alkali solution can be improved.

[0096] The first (meth)acrylate compound may be a difunctional (meth)acrylate compound, a difunctional or higher functional (meth)acrylate compound, a trifunctional (meth)acrylate compound, a trifunctional or higher functional (meth)acrylate compound, or a tetrafunctional or higher functional (meth)acrylate compound. The first (meth)acrylate compound may be a (meth)acrylate compound having 20 or less functionalities, a (meth)acrylate compound having 10 or less functionalities, or a (meth)acrylate compound having 5 or less functionalities. The number of functionalities corresponds to the number of (meth)acryloyl groups. The first (meth)acrylate compound may be used alone or in combination of two or more.

[0097] The first (meth)acrylate compound may have 2 (meth)acryloyl groups, 2 or more, 3 or more, 3 or more, 4 or more, 20 or less, 10 or less, or 5 or less.

[0098] Examples of the bifunctional (meth)acrylate compound having an alicyclic skeleton include ethoxylated cyclohexanemethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, 1,3-adamantanediol di(meth)acrylate, and propoxylated cyclohexanemethanol di(meth)acrylate.

[0099] Examples of the trifunctional (meth)acrylate compound having an alicyclic skeleton include pentaerythritol triacrylate-isophorone diisocyanate-urethane prepolymer and the like.

[0100] From the viewpoint of further improving the tolerance of the cured product to high temperature alkali solution when the curable composition is applied and cured, the first (meth) acrylate compound preferably has two (meth) acryloyl groups, preferably has a dicyclopentadiene skeleton. From the viewpoint of further improving the tolerance of the cured product to high temperature alkali solution when the curable composition is applied and cured, the first (meth) acrylate compound is more preferably a (meth) acrylate compound having two (meth) acryloyl groups and a dicyclopentadiene skeleton. It should be noted that in the dicyclopentadiene skeleton in the first (meth) acrylate compound, the double bond portion of dicyclopentadiene can react. For example, the dicyclopentadiene skeleton in the first (meth) acrylate compound can be a skeleton represented by the following formula (2). In the following formula (2), the right end and the left end are bonding sites with other groups.

[0101] [Chemical formula 3]

[0102]

[0103] The first (meth)acrylate compound preferably comprises ethoxylated cyclohexane methanol di(meth)acrylate or tricyclodecane dimethanol di(meth)acrylate, and more preferably comprises tricyclodecane dimethanol di(meth)acrylate. Tricyclodecane dimethanol di(meth)acrylate has a skeleton represented by the formula (2). In addition, from the viewpoint of further improving the resistance of the cured product to high temperature alkali solution when the curable composition is applied and cured, the first (meth)acrylate compound preferably has a tricyclodecane skeleton.

[0104] The glass transition temperature (Tg) of the homopolymer of the first (meth)acrylate compound is preferably 100° C. or higher, more preferably 150° C. or higher, and further preferably 190° C. or higher, and is preferably 250° C. or lower, and more preferably 220° C. or lower. When the glass transition temperature of the homopolymer of the first (meth)acrylate compound is above the lower limit and below the upper limit, when the curable composition is applied and cured, the adhesion between the substrate and the cured product can be further improved.

[0105] The glass transition temperature of the homopolymer of the first (meth)acrylate compound and the glass transition temperature of the homopolymer of the second (meth)acrylate compound described below refer to glass transition temperatures of homopolymers having a degree of polymerization of 3,000 to 4,000 (preferably 3,500).

[0106] The glass transition temperature can be measured using a differential scanning calorimeter at a temperature increase rate of 10° C. / min in accordance with JIS K7121. Examples of the differential scanning calorimeter include “DSC7020” manufactured by Hitachi High-Tech Science Co., Ltd., and the like.

[0107] In 100 wt % of the curable composition, the content of the first (meth)acrylate compound is preferably 5 wt % or more, more preferably 10 wt % or more, further preferably 20 wt % or more, particularly preferably 30 wt % or more, and preferably 80 wt % or less, more preferably 70 wt % or less, further preferably 60 wt % or less. When the content of the first (meth)acrylate compound is above the lower limit and below the upper limit, the effect of the present invention can be more effectively exerted.

[0108] <Second (meth)acrylate compound represented by formula (1)>

[0109] The curable composition contains a second (meth)acrylate compound represented by the following formula (1).

[0110] [Chemical formula 4]

[0111]

[0112] In the above formula (1), R1 and R2 each represent a hydrogen atom or a methyl group, and R3 represents an alkylene group.

[0113] Since the curable composition contains the second (meth)acrylate compound, when the curable composition is applied and cured, the adhesion between the substrate and the cured product can be improved.

[0114] In the formula (1), R1 and R2 may be the same or different.

[0115] From the viewpoint of suppressing the curing shrinkage generated when the curable composition is applied and cured, and further improving the adhesion between the substrate and the cured product, the carbon number of the alkylene group of R3 in the formula (1) is preferably 2 or more, more preferably 4 or more, and more preferably 6 or more, and preferably 16 or less, more preferably 14 or less, and more preferably 12 or less. From the viewpoint of suppressing the curing shrinkage generated when the curable composition is applied and cured, and further improving the adhesion between the substrate and the cured product, in the formula (1), R3 is particularly preferably an alkylene group with a carbon number of 6 or more and 12 or less.

[0116] Examples of the second (meth)acrylate compound include decanediol di(meth)acrylate, nonanediol di(meth)acrylate, and hexanediol di(meth)acrylate.

[0117] From the viewpoint of further improving the adhesion between the substrate and the cured product when the curable composition is applied and cured, the second (meth)acrylate compound is preferably nonanediol di(meth)acrylate or hexanediol di(meth)acrylate, and more preferably nonanediol di(meth)acrylate.

[0118] The glass transition temperature (Tg) of the homopolymer of the second (meth)acrylate compound is preferably -50°C or higher, more preferably -40°C or higher, further preferably -30°C or higher, preferably 50°C or lower, more preferably 40°C or lower. When the glass transition temperature of the homopolymer of the second (meth)acrylate compound is above the lower limit and below the upper limit, when the curable composition is applied and cured, the adhesion between the substrate and the cured product can be further improved.

[0119] In 100 wt % of the curable composition, the content of the second (meth)acrylate compound is preferably 10 wt % or more, more preferably 15 wt % or more, further preferably 20 wt % or more, preferably 70 wt % or less, more preferably 60 wt % or less, further preferably 55 wt % or less. When the content of the second (meth)acrylate compound is above the lower limit and below the upper limit, when the curable composition is applied and cured, the adhesion between the substrate and the cured product can be further improved.

[0120] The content of the second (meth)acrylate compound is preferably 20 parts by weight or more, more preferably 30 parts by weight or more, and even more preferably 40 parts by weight or more, relative to 100 parts by weight of the first (meth)acrylate compound, and is preferably 250 parts by weight or less, more preferably 200 parts by weight or less, and even more preferably 150 parts by weight or less. When the content of the second (meth)acrylate compound is above the lower limit and below the upper limit, the effect of the present invention can be more effectively exerted.

[0121] <Photopolymerization Initiator>

[0122] The curable composition includes the photopolymerization initiator.

[0123] The curable composition includes the photopolymerization initiator, and thus the curable composition can be cured by irradiation with light.

[0124] Examples of the photopolymerization initiator include a photoradical polymerization initiator and a photocationic polymerization initiator. The photopolymerization initiator is preferably a photoradical polymerization initiator. The photopolymerization initiator may be used alone or in combination of two or more.

[0125] The photoradical polymerization initiator is a compound that generates free radicals by irradiation with light and is used to initiate a free radical polymerization reaction. Examples of the photoradical polymerization initiator include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; alkyl phenone compounds such as 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methylpropiophenone; acetophenone compounds such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, and 1,1-dichloroacetophenone; 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one, 2-benzyl- 2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholino)phenyl]-1-butanone, 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, N,N-dimethylaminoacetophenone and other amino acids acetophenone compounds; anthraquinone compounds such as 2-methylanthraquinone, 2-ethylanthraquinone, and 2-tert-butylanthraquinone; thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; acetophenone dimethyl ketal, benzil dimethyl ketal, and other ketal compounds; acyl phosphine oxide compounds such as 2,4,6-trimethylbenzoyl diphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; 1,2-octanedione, 1-[ 4-(phenylthio)-2-(o-benzoyl oxime)], ethyl ketone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(o-acetyl oxime) and other oxime ester compounds; bis(cyclopentadienyl)-di-phenyl-titanium, bis(cyclopentadienyl)-di-chloro-titanium, bis(cyclopentadienyl)-bis(2,3,4,5,6-pentafluorophenyl)titanium, bis(cyclopentadienyl)-bis(2,6-difluoro-3-(pyrrol-1-yl)phenyl)titanium and other titanocene compounds. The photoradical polymerization initiator can be used alone or in combination of two or more.

[0126] The photopolymerization initiator preferably includes 2-dimethylamino-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]1-butanone or 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone. The curability of the curable composition can be improved by using these preferred photopolymerization initiators, so when the curable composition is applied and cured, the adhesion between the substrate and the cured product can be further improved.

[0127] A photopolymerization initiation aid may be used together with the photo radical polymerization initiator. Examples of the photopolymerization initiation aid include ethyl N,N-dimethylaminobenzoate, isopentyl N,N-dimethylaminobenzoate, amyl-4-dimethylaminobenzoate, triethylamine, and triethanolamine. The photopolymerization initiation aid may be used alone or in combination of two or more.

[0128] Furthermore, a titanocene compound such as CGI-784 (manufactured by CHIBA SPECIALTY CHEMICALS) which absorbs in the visible light region may be used to promote the photoreaction.

[0129] Examples of the photocationic polymerization initiator include sulfonium salts, iodonium salts, metallocene compounds, and benzoin p-toluenesulfonate. The photocationic polymerization initiator may be used alone or in combination of two or more.

[0130] In 100 wt % of the curable composition, the content of the photopolymerization initiator is preferably 4 wt % or more, more preferably 5 wt % or more, preferably 15 wt % or less, more preferably 12 wt % or less. When the content of the photopolymerization initiator is above the lower limit and below the upper limit, the curability of the curable composition can be improved, so when the curable composition is applied and cured, the adhesion between the substrate and the cured product can be further improved.

[0131] The content of the photopolymerization initiator is preferably 4 parts by weight or more, more preferably 5 parts by weight or more, and preferably 20 parts by weight or less, more preferably 15 parts by weight or less, relative to 100 parts by weight of the total of the first (meth)acrylate compound and the second (meth)acrylate compound. When the content of the photopolymerization initiator is above the lower limit and below the upper limit, the curability of the curable composition can be improved, so when the curable composition is applied and cured, the adhesion between the substrate and the cured product can be further improved.

[0132] <Colorant>

[0133] The curable composition includes the colorant.

[0134] Since the curable composition includes the colorant, it is suitable for forming a marking portion. Since the curable composition includes the colorant, it is suitable for use as a marking material.

[0135] As the colorant, dyes and pigments can be cited. The colorant can be used alone or in combination of two or more. When only one colorant is used, the manufacturing process of the curable composition becomes simpler. When two or more colorants are used in combination, the coloring of the curable composition becomes easy.

[0136] As the dye, pyrazole azo dye, anilino azo dye, triphenylmethane dye, anthraquinone dye, anthrapyridone dye, benzylidene dye, oxolyl dye, pyrazolotriazole azo dye, pyridone azo dye, cyanine dye, phenothiazine dye, pyrrolopyrazole azomethine dye, xanthene dye, phthalocyanine dye, benzopyran dye, indigo dye, pyrromethene dye, triarylmethane dye, azomethine dye, perylene dye, pyrenone dye, quaterrylene dye and quinophthalone dye etc. can be mentioned. The dye can be acid dye, direct dye, basic dye, mordant dye, acid mordant dye, azo dye, disperse dye, oil-soluble dye, food dye and by mixing two or more of these derivatives to make black dye etc. The dye can be used only one kind, and can also be used in combination of two or more kinds.

[0137] The pigment may be an organic pigment or an inorganic pigment. The organic pigment may be an organic pigment having a metal atom or an organic pigment not having a metal atom. The pigment may be used alone or in combination of two or more.

[0138] Examples of the organic pigment include phthalocyanine compounds, quinacridone compounds, azo compounds, dibenzophenanthrene compounds, perylene compounds, indole compounds, and dioxazine compounds.

[0139] Examples of the phthalocyanine compound include copper phthalocyanine compounds.

[0140] Examples of the inorganic pigment include carbon black, carbon nanotubes, graphene, iron oxide, zinc oxide, titanium oxide, calcium carbonate, aluminum oxide, kaolin clay, calcium silicate, magnesium oxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, talc, feldspar powder, mica, barite, barium carbonate, silica, and glass beads.

[0141] From the viewpoint of improving heat resistance, the colorant preferably contains a pigment. From the viewpoint of improving visibility, the colorant is preferably a black pigment or a blue pigment.

[0142] From the viewpoint of improving heat resistance, the colorant more preferably contains carbon black or a phthalocyanine compound, and particularly preferably contains carbon black or a copper phthalocyanine compound.

[0143] From the viewpoint of improving visibility, the content of the colorant in 100 wt % of the curable composition is preferably 0.1 wt % or more, more preferably 0.5 wt % or more, and is preferably 5 wt % or less, more preferably 3 wt % or less.

[0144] <Dispersant>

[0145] The curable composition may contain a dispersant. From the viewpoint of improving dispersibility, the curable composition preferably further contains a dispersant. In particular, when the colorant contains carbon black, the curable composition preferably further contains a dispersant.

[0146] Examples of the dispersant include polyurethane-based dispersants, phosphate-based dispersants, carboxylic acid-based dispersants, amine-based dispersants, and ricinoleate-based dispersants. The dispersants may be used alone or in combination of two or more.

[0147] Examples of the polyurethane dispersant include basic polyurethane, polyurethane-acrylic, polyurethane-polyurea, polyester-polyurethane, polyether-polyurethane, and polysiloxane polyurethane.

[0148] Examples of the phosphate dispersant include polyoxyethylene nonylphenyl ether phosphate, polyoxyethylene tridecyl ether phosphate, polyoxyethylene octylphenyl ether phosphate and other polyoxyalkylene alkylphenyl ether phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl ether phosphates·monoethanolamine salts, polyoxyethylene lauryl ether phosphates, polyoxyethylene lauryl ether phosphates·monoethanolamine salts, polyethylene styrenated phenyl ether phosphates, sodium alkyl phosphates and monoethanolamine salts of alkyl phosphates.

[0149] The carboxylic acid-based dispersant is preferably a polycarboxylic acid. Examples of the polycarboxylic acid include polycarboxylic acid polymers in which a polymer having a carboxyl group in the main chain skeleton is grafted with a polyoxyalkylene group.

[0150] The weight average molecular weight of the polycarboxylic acid is preferably 500 or more, more preferably 1000 or more, and further preferably 2000 or more, and preferably 1500000 or less, more preferably 1250000 or less, and further preferably 1000000 or less. The weight average molecular weight refers to the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

[0151] Examples of the amine dispersant include tetradecylamine acetate, laurylamine, oleylamine, distearylamine, and dimethyllaurylamine.

[0152] Examples of the ricinoleic acid ester dispersant include glycerol ricinoleic acid monoester, polyglycerol ricinoleic acid monoester, and acetyl ricinoleic acid ester.

[0153] From the viewpoint of improving dispersibility, the dispersant preferably contains a phosphate ester dispersant.

[0154] From the viewpoint of improving dispersibility, the content of the dispersant in 100 wt % of the curable composition is preferably 0.1 wt % or more, more preferably 0.5 wt % or more, preferably 5 wt % or less, more preferably 3 wt % or less, and further preferably 2 wt % or less.

[0155] From the viewpoint of improving dispersibility, the content of the dispersant is preferably 25 parts by weight or more, more preferably 50 parts by weight or more, and further preferably 75 parts by weight or more, and is preferably 150 parts by weight or less, more preferably 125 parts by weight or less, and further preferably 110 parts by weight or less, relative to 100 parts by weight of the colorant.

[0156] <Solvent>

[0157] The curable composition may or may not contain a solvent. The curable composition may or may not contain a solvent. From the viewpoint of suppressing the curing shrinkage generated when the solvent evaporates and further improving the adhesion between the substrate and the cured product, the less the content of the solvent in the curable composition, the better.

[0158] Examples of the solvent include water and organic solvents.

[0159] From the viewpoint of further improving the removability of the residue, the solvent is preferably an organic solvent. As the organic solvent, alcohols such as ethanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, and tripropylene glycol monomethyl ether; esters such as ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; and petroleum solvents such as petroleum ether and naphtha.

[0160] From the viewpoint of suppressing the curing shrinkage generated when the solvent evaporates and further improving the adhesion between the substrate and the cured product, the curable composition preferably does not contain the solvent or contains 5% by weight or less of the solvent in 100% by weight of the curable composition. From the viewpoint of suppressing the curing shrinkage generated when the solvent evaporates and further improving the adhesion between the substrate and the cured product, when the curable composition contains the solvent, the content of the solvent in 100% by weight of the curable composition is preferably 5% by weight or less, more preferably 1% by weight or less, and more preferably 0.5% by weight or less. The lower limit of the content of the solvent is not particularly limited. The content of the solvent can be 0% by weight (not contained), can be more than 0% by weight, and can be more than 0.5% by weight.

[0161] <Thermosetting Compound>

[0162] The curable composition may or may not contain a thermosetting compound. The curable composition may or may not contain a thermosetting compound. From the viewpoint of suppressing the generation of outgassing when the curable composition is heated, the content of the thermosetting compound in the curable composition is as small as possible.

[0163] Examples of the thermosetting compound include oxetane compounds, epoxy compounds, episulfide compounds, (meth)acrylic compounds, phenol compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, polysiloxane compounds, and polyimide compounds. The thermosetting compound may be used alone or in combination of two or more.

[0164] The heat-curable compound may be used in combination with a heat-curing agent. The curable composition may include a heat-curable compound and a heat-curing agent. The heat-curing agent heat-cures the heat-curable compound.

[0165] Examples of the thermal curing agent include imidazole curing agents, amine curing agents, phenol curing agents, thiol curing agents such as polythiol curing agents, acid anhydride curing agents, thermal cationic initiators (thermal cationic curing agents), and thermal free radical initiators. The thermal curing agent may be used alone or in combination of two or more.

[0166] From the viewpoint of further improving the adhesion between the substrate and the cured product, the curable composition preferably does not contain the thermosetting compound, or the curable composition contains less than 5% by weight of the thermosetting compound in 100% by weight. From the viewpoint of further improving the adhesion between the substrate and the cured product, when the curable composition contains the thermosetting compound, the content of the thermosetting compound in 100% by weight of the curable composition is preferably less than 4% by weight, more preferably less than 3% by weight, and further preferably less than 2% by weight. The lower limit of the content of the thermosetting compound is not particularly limited. The content of the thermosetting compound can be 0% by weight (not contained), can be more than 0% by weight, and can be more than 0.5% by weight.

[0167] The content of the thermosetting agent is preferably 10 parts by weight or more, more preferably 20 parts by weight or more, further preferably 25 parts by weight or more, particularly preferably 30 parts by weight or more, preferably 60 parts by weight or less, more preferably 55 parts by weight or less, further preferably 50 parts by weight or less, relative to 100 parts by weight of the thermosetting compound. When the content of the thermosetting agent is above the lower limit and below the upper limit, the thermosetting compound can be cured well.

[0168] <Other ingredients>

[0169] The curable composition may include other components other than the first (meth)acrylate compound, the second (meth)acrylate compound, the photopolymerization initiator, the colorant, the solvent, the dispersant, and the thermosetting compound. Examples of the other components include fillers, defoamers, coupling agents, curing agents, curing accelerators, mold release agents, surface treatment agents, flame retardants, viscosity modifiers, dispersants, dispersing aids, surface modifiers, plasticizers, antibacterial agents, antifungal agents, leveling agents, stabilizers, anti-sagging agents, and phosphors.

[0170] The curable composition may contain a (meth)acrylate compound other than the first (meth)acrylate compound and the second (meth)acrylate compound (hereinafter, sometimes referred to as “other (meth)acrylate compound”).

[0171] The other (meth)acrylate compound may be a monofunctional (meth)acrylate compound or a multifunctional (meth)acrylate compound.

[0172] Examples of the other (meth)acrylate compound include polypropylene glycol #700 diacrylate, polypropylene glycol #400 diacrylate, and tripropylene glycol diacrylate. From the viewpoint of further improving the adhesion between the substrate and the cured product, the other (meth)acrylate compound is preferably polypropylene glycol #700 diacrylate.

[0173] From the viewpoint of further improving the adhesion between the substrate and the cured product, the other (meth)acrylate compound (the marking material) preferably includes a carbamate (meth)acrylate compound having a (meth)acryloyl group. The carbamate (meth)acrylate compound may have 1 (meth)acryloyl group, may have 2 or more (meth)acryloyl groups, may have 3 or more (meth)acryloyl groups, and may have 4 or more (meth)acryloyl groups. The carbamate (meth)acrylate compound may have less than 100 (meth)acryloyl groups, and may have less than 50 (meth)acryloyl groups. The carbamate (meth)acrylate compound may be a monofunctional carbamate (meth)acrylate compound or a multifunctional carbamate (meth)acrylate compound.

[0174] From the viewpoint of improving photocurability, the carbamate (meth) acrylate compound is preferably a carbamate (meth) acrylate compound having a plurality of (meth) acryloyl groups. From the viewpoint of further improving photocurability, the number of (meth) acryloyl groups in the carbamate (meth) acrylate compound is preferably 2 or more, more preferably 3 or more, more preferably 4 or more, preferably 8 or less, more preferably 7 or less, and more preferably 6 or less. From the viewpoint of further improving photocurability, the carbamate (meth) acrylate compound particularly preferably has 4 or more and 6 or less (meth) acryloyl groups.

[0175] From the viewpoint of further improving the adhesion between the substrate and the cured product, the urethane (meth)acrylate compound is preferably a urethane (meth)acrylate compound having an aromatic skeleton.

[0176] Examples of the aromatic skeleton include a naphthalene skeleton, a fluorene skeleton, a phenyl skeleton, a biphenyl skeleton, an anthracene skeleton, a pyrene skeleton, a xanthene skeleton, an adamantane skeleton, and a bisphenol A type skeleton.

[0177] From the viewpoint of further improving the adhesion between the substrate and the cured product, the aromatic skeleton in the urethane (meth) acrylate compound is preferably a phenyl skeleton or a biphenyl skeleton. From the viewpoint of further improving the adhesion between the substrate and the cured product, the urethane (meth) acrylate compound preferably includes a urethane (meth) acrylate compound having a phenyl skeleton or a biphenyl skeleton, and more preferably includes a urethane (meth) acrylate compound having a biphenyl skeleton.

[0178] As the urethane (meth)acrylate compound having a biphenyl skeleton, a commercially available product can be used. Examples of the commercially available product of the urethane (meth)acrylate compound having a biphenyl skeleton include EBECRYL220 (manufactured by DAICEL ALLNEX) and EBECRYL210 (manufactured by DAICEL ALLNEX).

[0179] From the viewpoint of further improving the adhesion between the substrate and the cured product, the curable composition preferably further comprises a (meth)acrylamide compound. From the viewpoint of further improving the adhesion between the substrate and the cured product, the other (meth)acrylate compound preferably comprises a (meth)acrylamide compound.

[0180] Examples of the (meth)acrylamide compound include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, N,N-diethylaminopropyl(meth)acrylamide, N,N-dimethylaminoethyl(meth)acrylamide, N,N-diethylaminoethyl(meth)acrylamide, and (meth)acryloylmorpholine.

[0181] From the viewpoint of further improving the adhesion between the substrate and the cured product, the (meth)acrylamide compound preferably contains (meth)acryloylmorpholine.

[0182] As the (meth)acryloylmorpholine, a commercially available item may be used. Examples of the commercially available item of the (meth)acryloylmorpholine include ACMO (manufactured by KJ CHEMICALS Co., Ltd.).

[0183] (Electronic component and method for manufacturing electronic component)

[0184] The electronic component of the present invention comprises an electronic component body and a marking portion disposed on the surface of the electronic component body. The marking portion is formed using the curable composition for inkjet. The marking portion comprises a cured product of the curable composition for inkjet.

[0185] The method for manufacturing an electronic component of the present invention comprises the following steps: (1) a step of applying the inkjet curable composition on the surface of the electronic component body using an inkjet device to form a marking layer (coating step); and (2) a step of curing the marking layer by irradiating light to form a marking portion (photocuring step).

[0186] Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0187] Figure 1 (a) and (b) are schematic cross-sectional views for explaining the method for manufacturing the electronic component according to the first embodiment of the present invention.

[0188] First, if Figure 1 As shown in (a), a curable composition (marking material) is applied on the surface of the electronic component body 1 using an inkjet device to form a marking layer 3A (coating step). The curable composition (marking material) is discharged from a discharge unit 51 of the inkjet device.

[0189] Next, if Figure 1 As shown in (b), the light irradiation unit 52 of the inkjet device irradiates light to the marking layer 3A, and the marking layer 3A is cured to form the marking portion 3B (photocuring step). The light irradiation unit 52 of the inkjet device irradiates light to cure the marking layer 3A to form the marking portion 3B.

[0190] It should be noted that after the photocuring step, the coating step and the photocuring step may be repeated. When the coating step and the photocuring step are repeated, the curable composition is coated on the surface side of the formed marking portion 3B opposite to the electronic component body 1 side.

[0191] The thickness of the marking portion can be increased by performing the coating step and the photocuring step multiple times in the thickness direction of the marking layer. The coating step and the photocuring step can be performed more than 2 times, more than 3 times, less than 1000 times, or less than 100 times.

[0192] In this way, the electronic component 10 can be obtained.

[0193] In the photocuring step, ultraviolet rays are preferably irradiated. The irradiance and irradiation time of ultraviolet rays in the photocuring step can be appropriately changed according to the composition of the curable composition and the coating thickness of the curable composition. The irradiance of ultraviolet rays in the photocuring step can be, for example, 1000 mW / cm 2 Above, can be 5000mW / cm 2 Above, and can be 10000mW / cm 2 Below, it can be 8000mW / cm 2 The irradiation time of ultraviolet rays in the photocuring step may be, for example, 0.01 seconds or longer, 0.1 seconds or longer, and 400 seconds or shorter, or 100 seconds or shorter.

[0194] The width and thickness of the marking portion may be changed as appropriate.

[0195] The width of the marking portion may be greater than or equal to 30 μm, greater than or equal to 50 μm, or greater than or equal to 70 μm, and may be less than or equal to 1000 μm, less than or equal to 800 μm, or less than or equal to 700 μm.

[0196] The thickness of the marking portion may be greater than or equal to 1 μm, greater than or equal to 5 μm, and less than or equal to 100 μm, less than or equal to 50 μm, less than or equal to 30 μm, or less than or equal to 10 μm.

[0197] Examples of the electronic components include electrolytic capacitors, coils, capacitors, antennas, printed wiring boards, and touch panel components.

[0198] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited to the following Examples.

[0199] Prepare the following materials.

[0200] The first (meth)acrylate compound:

[0201] Tricyclodecane dimethanol diacrylate ("IRR-214K" manufactured by DAICEL ALLNEX, glass transition temperature of homopolymer: 190°C)

[0202] Ethoxylated cyclohexane methanol diacrylate ("HBPE-4" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., glass transition temperature of homopolymer: 50°C)

[0203] Second (meth)acrylate compound:

[0204] 1,9-nonanediol diacrylate ("VISCOAT #260" manufactured by Osaka Organic Chemical Industry Co., Ltd., glass transition temperature of homopolymer: 68°C)

[0205] 1,6-Hexanediol diacrylate ("VISCOAT#230" manufactured by Osaka Organic Chemical Industry Co., Ltd., glass transition temperature of homopolymer: 63°C)

[0206] Other (meth)acrylate compounds:

[0207] Propylene oxide-modified bisphenol A diacrylate ("LIGHT ACRYLAT E BP-4PA" manufactured by Kyoeisha Chemical Co., Ltd., glass transition temperature of homopolymer: 80°C)

[0208] Ethoxylated bisphenol A diacrylate ("ABE-300" manufactured by Shin-Nakamura Chemical Co., Ltd., glass transition temperature of homopolymer: 75°C)

[0209] Polypropylene glycol #700 diacrylate ("APG-700" manufactured by Shin-Nakamura Chemical Co., Ltd., glass transition temperature of homopolymer: 32°C)

[0210] Ethylene oxide-modified trimethylolpropane triacrylate ("Laromer LR8863" manufactured by BASF, glass transition temperature of homopolymer: 110°C)

[0211] Dipropylene glycol diacrylate ("DPGDA" manufactured by DAICEL ALLNEX, glass transition temperature of homopolymer: 110°C)

[0212] Urethane acrylate having 6 (meth)acryloyl groups ("EBECRYL 220" manufactured by Daicel Allnex, glass transition temperature of a homopolymer having an aromatic skeleton: 49°C)

[0213] Acryloylmorpholine (acrylamide compound, "ACMO" manufactured by KJ CHEMICALS)

[0214] Photopolymerization initiator:

[0215] 2,4,6-Trimethylbenzoyldiphenylphosphine oxide ("Omnirad TPO" manufactured by IGM Resins)

[0216] 2-Dimethylamino-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]1-butanone ("Omnirad 379" manufactured by IGM Resins)

[0217] Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide ("Omnirad 819" manufactured by IGM Resins)

[0218] Colorants:

[0219] Carbon black (Mitsubishi Chemical Corporation "Carbon Black #10")

[0220] Carbon black (Carbon black MA14 manufactured by Mitsubishi Chemical Corporation)

[0221] Copper phthalocyanine compound (pigment, "Oil Blue 5511-N" manufactured by ORIENT CHEMICAL INDUSTRIES)

[0222] Copper phthalocyanine compound (pigment, "OPLA S BLUE 635" manufactured by ORIENT CHEMICAL INDUSTRIES)

[0223] Titanium oxide ("PF-726" manufactured by Ishihara Sangyo Co., Ltd.)

[0224] Pigment Violet 37 (violet pigment, "CROMOPHTAL VIOLET B" manufactured by BASF)

[0225] Pigment Red 122 (red pigment, "Fastogen Super Magenta RGT" manufactured by DIC Corporation)

[0226] Solvent Green 5 (yellow pigment, "PLAST YELLOW 8025" manufactured by Arimoto Chemical Co., Ltd.)

[0227] Dispersants:

[0228] Phosphate ester dispersant ("DISPERBYK-106" manufactured by BYK)

[0229] Phosphate ester dispersant ("DISPERBYK-145" manufactured by BYK)

[0230] Polyacrylic acid dispersant (manufactured by BASF, "PX4701")

[0231] Phosphate ester dispersant ("DISPERBYK-9076" manufactured by BYK)

[0232] Polycaprolactone dispersant (manufactured by AJINOMOTO FINE-TECHNO CO., LTD., “AJISPERPB821”)

[0233] Solvent:

[0234] Tripropylene glycol monomethyl ether (TPM)

[0235] (Examples 1 to 29 and Comparative Examples 1 to 4)

[0236] The components shown in Tables 1, 3, 5, 7, 9, 11, and 13 below were blended in the blending amounts (unit: parts by weight) shown in Tables 1, 3, 5, 7, 9, 11, and 13 below to obtain curable compositions for inkjet (curable compositions).

[0237] (evaluate)

[0238] (1) Adhesion between substrate and cured product

[0239] The obtained curable composition was ejected from the inkjet head of a piezoelectric inkjet printer equipped with an ultraviolet irradiation device onto the surface of an aluminum substrate (size 5 cm×5 cm) to form a marking layer. Then, for Examples 1 to 14, 28 to 29 and Comparative Examples 1 to 4, the illuminance at a wavelength of 365 nm was 1000 mW / cm 2 The cumulative amount of light irradiated is 1000mJ / cm 2 The marking layer was cured by ultraviolet light (UV-LED) to form a marking portion (thickness 10 μm). In addition, for Examples 15 to 27, the illuminance at a wavelength of 365 nm was 6000 mW / cm 2 The total amount of light irradiated is 3000mJ / cm 2 The marking layer was cured by ultraviolet light (UV-LED) to form a marking portion (thickness 10 μm). After a tape ("CELLO TAPE (registered trademark) manufactured by NICHIBAN) was attached to the entire marking portion, the tape was peeled off from the edge. The adhesion (tape peeling resistance) between the substrate and the marking portion (cured product) was determined based on the following criteria.

[0240] [Criteria for determining adhesion between substrate and cured product]

[0241] ○○: No peeling of the marked part

[0242] ○: The area of ​​the peeled portion is 10% or less out of the total area of ​​the marked portion (100%)

[0243] ×: The area of ​​the peeled portion exceeds 10% of the total area of ​​the marked portion (100%)

[0244] (2) Tolerance to high temperature alkali solution

[0245] The obtained curable composition was ejected from the inkjet head of a piezoelectric inkjet printer equipped with an ultraviolet irradiation device onto the surface of an aluminum substrate (size 5 cm×5 cm) to form a marking layer. Then, for Examples 1 to 14, 28 to 29 and Comparative Examples 1 to 4, the illuminance at a wavelength of 365 nm was 1000 mW / cm 2 The cumulative amount of light irradiated is 1000mJ / cm 2 The marking layer was cured by ultraviolet light (UV-LED) to form a marking portion (thickness 10 μm). In addition, for Examples 15 to 27, the illuminance at a wavelength of 365 nm was 6000 mW / cm 2 The total amount of light irradiated is 3000mJ / cm 2 The marking layer was cured by ultraviolet light (UV-LED) to form a marking portion (thickness 10 μm). The substrate with the marking portion was placed in an alkaline solution (pH 9.5, "CLEANTHROUGH 750HS" manufactured by Kao Corporation) heated to 60°C, and ultrasonic waves of 40 kHz were applied to clean it for 10 minutes. The resistance of the marking portion (cured product) to the high-temperature alkaline solution was determined based on the following criteria.

[0246] [Criteria for determination of resistance to high temperature alkali solution]

[0247] ○○: No peeling of the marked part

[0248] ○: The area of ​​the peeled portion is 20% or less out of the total area of ​​the marked portion (100%)

[0249] ×: The area of ​​the peeled portion exceeds 20% of the total area of ​​the marked portion (100%)

[0250] (3) Viscosity at 25°C

[0251] The viscosity of the obtained curable composition was measured under the conditions of 25° C. and 10 rpm using an E-type viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.).

[0252] (4) Glass transition temperature of the cured product

[0253] For Examples 1 to 14, 28 to 29 and Comparative Examples 1 to 4, the steps of applying the obtained curable composition to a thickness of 10 μm by spin coating (“MS-A100” manufactured by MIKASA) and the steps of setting the illuminance at a wavelength of 365 nm to 1000 mW / cm 2The cumulative amount of light irradiated is 1000mJ / cm 2 In addition, for Examples 15 to 27, the steps of applying the obtained curable composition with a thickness of 10 μm by using a spin coating method ("MS-A100" manufactured by MIKASA) and the illumination at a wavelength of 365 nm was repeated to obtain a cured product of the curable composition (thickness 300 μm). 2 The total amount of light irradiated is 3000mJ / cm 2 The cured product of the curable composition (thickness 300 μm) was obtained by the step of ultraviolet irradiation. The glass transition temperature of the cured product of the curable composition was measured using a dynamic viscoelasticity measuring apparatus at a temperature increase rate of 10° C. / min and a frequency of 10 Hz.

[0254] (5) Weight change rate of cured product

[0255] The cured product (thickness 300 μm) of the curable composition obtained in (1) was immersed in water at 60° C. for 1 hour and then heated at 170° C. for 1 hour to calculate the following weight change rate.

[0256] Weight change rate (%) = |W3-W2| × 100 / W1

[0257] W1: Weight of the cured product of the curable composition before immersion

[0258] W2: Weight of the cured product of the curable composition after immersion and before heating

[0259] W3: Weight of the cured product of the curable composition after heating

[0260] (6) Dispensability of curable composition

[0261] The obtained curable composition was ejected from the inkjet head of a piezoelectric inkjet printer equipped with an ultraviolet irradiation device onto the surface of an aluminum substrate (size 5 cm×5 cm). The ejection properties of the curable composition were determined based on the following criteria. It should be noted that the temperature of the inkjet head was controlled to 25°C to 75°C so that the viscosity of the curable composition during ejection was 10 mPa·s, and the curable composition was ejected.

[0262] [Criteria for Determining the Dischargeability of Curable Composition]

[0263] ○○: The curable composition can be ejected without unevenness

[0264] ○: The curable composition can be ejected, but unevenly

[0265] ×: Curable composition cannot be ejected

[0266] (7) Printability of curable composition

[0267] The obtained curable composition was ejected from the inkjet head of a piezoelectric inkjet printer equipped with an ultraviolet irradiation device onto the surface of an aluminum substrate (size 5 cm×5 cm), and display information (marking layer) consisting of characters and symbols was printed. Then, for Examples 1 to 14, 28 to 29 and Comparative Examples 1 to 4, after 2 seconds, the illuminance at a wavelength of 365 nm was 1000 mW / cm 2 The cumulative amount of light irradiated is 1000mJ / cm 2 The marking layer was cured by ultraviolet light (UV-LED) to form a marking portion (thickness 10 μm). In addition, for Examples 15 to 27, after 2 seconds, the illuminance at a wavelength of 365 nm was 6000 mW / cm 2 The total amount of light irradiated is 3000mJ / cm 2 The marking layer was cured by ultraviolet light (UV-LED) to form a marking portion (thickness 10 μm). The printability of the curable composition was evaluated based on the following criteria.

[0268] [Criteria for Determining Printability of Curable Composition]

[0269] ○○: The displayed information of the marked part can be recognized

[0270] ○: The information displayed on the mark is partially blurred but can be recognized

[0271] ×: The displayed information of the marked part cannot be recognized

[0272] The compositions of the curable compositions and the results are shown in Tables 1 to 14 below.

[0273] [Table 1]

[0274]

[0275] [Table 2]

[0276]

[0277] [Table 3]

[0278]

[0279] [Table 4]

[0280]

[0281] [Table 5]

[0282]

[0283] [Table 6]

[0284]

[0285] [Table 7]

[0286]

[0287] [Table 8]

[0288]

[0289] [Table 9]

[0290]

[0291] [Table 10]

[0292]

[0293] [Table 11]

[0294]

[0295] [Table 12]

[0296]

[0297] [Table 13]

[0298]

[0299] [Table 14]

[0300]

[0301] Explanation of symbols

[0302] 1…Electronic component body

[0303] 3A…Marking layer

[0304] 3B…Marking Department

[0305] 10…Electronic components

[0306] 51…Ejection part

[0307] 52...Light irradiation part

Claims

1. A curable composition for inkjet, comprising: a first (meth)acrylate compound having a plurality of (meth)acryloyl groups and an alicyclic skeleton; A second (meth)acrylate compound represented by the following formula (1); a photopolymerization initiator; and Colorants, [Chemical formula 1] In the above formula (1), R1 and R2 each represent a hydrogen atom or a methyl group, and R3 represents an alkylene group.

2. The curable composition for inkjet according to claim 1, wherein The colorant includes carbon black.

3. The curable composition for inkjet according to claim 1 or 2, wherein The colorant includes a copper phthalocyanine compound.

4. The curable composition for inkjet according to any one of claims 1 to 3, wherein In the above formula (1), R3 is an alkylene group having 6 to 12 carbon atoms.

5. The curable composition for inkjet according to any one of claims 1 to 4, wherein The first (meth)acrylate compound is a (meth)acrylate compound having two (meth)acryloyl groups and a dicyclopentadiene skeleton. 6 . The curable composition for inkjet according to claim 1 , comprising a urethane (meth)acrylate compound having a (meth)acryloyl group.

7. The curable composition for inkjet according to claim 6, wherein The urethane (meth)acrylate compound is a urethane (meth)acrylate compound having a plurality of (meth)acryloyl groups. 8 . The curable composition for inkjet according to claim 1 , comprising a (meth)acrylamide compound. 9 . The curable composition for inkjet according to claim 1 , which contains no solvent, or contains 1% by weight or less of a solvent in 100% by weight of the curable composition for inkjet.

10. The curable composition for inkjet according to any one of claims 1 to 9, further comprising a dispersant, The content of the dispersant is 25 parts by weight or more and 150 parts by weight or less relative to 100 parts by weight of the colorant.

11. The curable composition for inkjet according to any one of claims 1 to 10, wherein The content of the first (meth)acrylate compound in 100% by weight of the curable composition for inkjet is 5% by weight or more and 70% by weight or less. 12 . The curable composition for inkjet according to claim 1 , which contains no thermosetting compound, or contains 5% by weight or less of the thermosetting compound in 100% by weight of the curable composition for inkjet.

13. The curable composition for inkjet according to any one of claims 1 to 12, wherein When a cured product of the curable composition for inkjet is immersed in water at 60° C. for 1 hour and then heated at 170° C. for 1 hour, the following weight change rate is less than 5.0%. Weight change rate (%) = |W3-W2| × 100 / W1 W1: weight of the cured product of the curable composition for inkjet before immersion; W2: the weight of the cured product of the curable composition for inkjet after immersion and before heating; W3: The weight of the cured product of the curable composition for inkjet after heating.

14. The curable composition for inkjet according to claim 13, wherein The weight change rate is 2.0% or less.

15. The curable composition for inkjet according to any one of claims 1 to 14, wherein The glass transition temperature of the cured product of the curable composition for inkjet is 80° C. or higher. 16 . The curable composition for inkjet according to claim 1 , which is used for forming a marking portion in an electronic component.

17. An electronic component comprising an electronic component body and a marking portion arranged on a surface of the electronic component body, The marking portion is formed using the curable composition for inkjet according to any one of claims 1 to 16.

18. A method for manufacturing an electronic component, comprising: A step of applying the curable inkjet composition according to any one of claims 1 to 16 on the surface of the electronic component body using an inkjet device to form a marking layer; and A step of curing the marking layer by irradiating light to form a marking portion.

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