Primer composition for electroless plating, laminate, and method for manufacturing the same.

Abstract

To provide a primer composition for electroless plating that enables the formation of a plating pattern with proper thickness without the need for etching.SOLUTION: A primer composition for electroless plating according to the present invention includes a phenoxy resin (A), a liquid epoxy resin (B), and a curing agent. The mass content of the liquid epoxy resin (B) is higher than that of the phenoxy resin (A).SELECTED DRAWING: Figure 1

Description

Technical Field

[0006] , , , , , , , ,

[0005] , <000,002><,000,003><,000,004>The present invention relates to a primer composition for electroless plating, a laminate, and a method for producing the same. <,000,005>

Background Art

Prior Art Documents

Patent Documents

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, methods for directly forming a predetermined wiring pattern on a transparent substrate without etching are also being investigated. For example, a method is being considered in which an ink containing Ag or Cu nanofillers is drawn in a pattern using various printing methods, and the nanofillers are sintered to form the wiring. However, it is difficult to form wiring with an appropriate thickness using this method, and it is necessary to perform the printing-sintering process multiple times, so a reduction in process cycle time is required. Accordingly, there is a need for a primer composition that can form a plating pattern of an appropriate thickness without etching, and that makes this possible.

[0008] This invention has been made in view of these circumstances, and aims to provide an electroless plating primer composition, a laminate, and a method for manufacturing an electroless plating that can form a plating pattern of appropriate thickness without etching. [Means for solving the problem]

[0009] The electroless plating primer composition of the present invention comprises a phenoxy resin (A), a liquid epoxy resin (B), and a curing agent, wherein the mass-based content of the liquid epoxy resin (B) is greater than the content of the phenoxy resin (A).

[0010] The laminate of the present invention comprises an insulating substrate, a base pattern disposed on the insulating substrate and containing a cured product of the electroless plating primer composition of the present invention, and a metal plating pattern disposed on the base pattern.

[0011] The present invention provides a method for manufacturing a laminate, comprising the steps of: applying a pattern of the electroless plating primer composition of the present invention onto an insulating substrate; curing the pattern of the primer composition to form a base pattern; and applying electroless plating to the surface of the base pattern to form a metal plating pattern. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a primer composition for electroless plating, a laminate, and a method for manufacturing the laminate, which enable the formation of a plating pattern of appropriate thickness without etching. [Brief explanation of the drawing]

[0013] [Figure 1] Figures 1A to 1C are schematic diagrams illustrating the process of applying patterns to primer compositions using the adhesion contrast printing method. [Figure 2] Figures 2A and 2B are schematic diagrams illustrating the preparation process for the adhesion contrast plate. [Modes for carrying out the invention]

[0014] One method for directly forming a predetermined plating pattern without etching is to first form a base pattern on an insulating substrate, and then bring the surface of the base pattern into contact with an electroless plating solution to form a metallic plating pattern.

[0015] There are various methods for forming a base pattern on an insulating substrate, one of which is the adhesion contrast printing method (see Figure 1 below). In the adhesion contrast printing method, a coating film 30 of a primer composition applied to a support 10 is brought into contact with an adhesion contrast plate 20 to obtain a pattern 30' of the primer composition (Figures 1A and 1B), and then the pattern 30' of the primer composition is transferred onto an insulating substrate 40 (Figure 1C). The pattern 30' of the primer composition on the insulating substrate 40 is then cured to form the base pattern.

[0016] In this method, it is desirable that the coating film of the primer composition be patterned according to the pattern of the adhesion contrast plate 20 (i.e., that it has good transferability to the adhesion contrast plate). Furthermore, it is desirable that the cured product of the primer composition formed on the insulating substrate 40 has a hardness suitable for reaction with the electroless plating solution.

[0017] The inventors have found that a primer composition comprising a phenoxy resin (A), a liquid epoxy resin (B), and a curing agent, wherein the content of the liquid epoxy resin (B) is greater than the content of the phenoxy resin (A), exhibits excellent coatability and transferability to the adhesion contrast plate 20. Furthermore, they have found that the cured product of the resulting primer composition possesses a hardness suitable for reaction with electroless plating solutions.

[0018] Specifically, the liquid epoxy resin (B) has a moderately low viscosity, which not only improves the applicability of the primer composition but also imparts appropriate softness to the coating film and cured product. On the other hand, the phenoxy resin (A) has excellent toughness, which can increase the film strength of the primer composition's coating film and cured product. A primer composition containing these in a balanced manner has a coating film with appropriate film strength, resulting in excellent transferability to the adhesion contrast plate. Furthermore, the cured product of the primer composition is not too hard, so it exhibits excellent reactivity with electroless plating solutions in the presence of a palladium catalyst. As a result, a plating pattern of appropriate thickness can be directly formed without etching.

[0019] The composition of the primer composition of the present invention will be described in detail below.

[0020] 1. Primer composition The primer composition of the present invention comprises a phenoxy resin (A), a liquid epoxy resin (B), and a curing agent.

[0021] And the content of the liquid epoxy resin (B) based on the mass is more than the content of the phenoxy resin (A). Specifically, the content ratio A / B of the phenoxy resin (A) and the liquid epoxy resin (B) is preferably 10 / 90 to 50 / 50 (mass ratio), more preferably 20 / 80 to 40 / 60 (mass ratio).

[0022] For example, in the adhesion intaglio printing method described above, if the content ratio of the liquid epoxy resin (B) is too high, the coating strength of the primer composition coating film becomes too low, and there is a risk of delamination during transfer to the adhesion contrast plate. On the other hand, if the content ratio of the phenoxy resin (A) is too high, the coating strength of the primer composition coating film becomes too high, and there is a risk that it will not be transferred at all or will be completely transferred to the adhesion contrast plate. That is, if the phenoxy resin (A) is too much or the liquid epoxy resin (B) is too much, the transferability to the adhesion contrast plate may not be sufficient. In contrast, when A / B is within the above range, the coating strength of the primer composition is appropriate, so the transferability to the adhesion contrast plate is excellent, and it can be accurately transferred along the adhesion contrast pattern. <000009​​​​​​​​​​​​Phenoxy resin (A) is a polymer having a polyhydroxypolyether structure obtained by polyaddition reaction of polyfunctional phenols and polyfunctional glycidyl ethers (preferably bisphenols and epichlorohydrin).

[0026] As described above, phenoxy resin (A), having such a structure, possesses excellent toughness and can therefore enhance the coating strength of the cured primer composition. Furthermore, because phenoxy resin (A) contains many hydroxyl groups in its molecule, it reacts well with melamine resin (C), described later, in the presence of melamine resin (C), forming a cross-linked structure, which can further enhance the coating strength of the cured primer composition.

[0027] The weight-average molecular weight (Mw) of phenoxy resin (A) is typically 10,000 to 200,000, preferably 20,000 to 100,000, and more preferably 30,000 to 80,000. When the Mw of phenoxy resin (A) is above a certain level, it is easier to obtain a cured primer composition with high coating strength, and when it is below a certain level, the viscosity of the primer composition does not increase excessively, and handling is not easily impaired. The Mw of phenoxy resin (A) can be determined by performing gel permeation chromatography (GPC) using tetrahydrofuran (THF) as the solvent and expressing it as a value equivalent to standard polystyrene.

[0028] The secondary hydroxyl group equivalent of phenoxy resin (A) is not particularly limited, but is preferably 240 g / eq or more, and more preferably 250 to 290 g / eq. When the secondary hydroxyl group equivalent of phenoxy resin (A) is within the above range, it contains a large amount of hydroxyl groups, which not only makes it more reactive with melamine resin (C) but also makes it easier to improve adhesion to insulating substrates.

[0029] The phenoxy resin (A) may have epoxy groups in its molecule. The epoxy equivalent of the phenoxy resin (A) is preferably 5000 g / eq or more, more preferably 6500 g / eq or more. The epoxy equivalent can be measured in accordance with JIS K7236.

[0030] Examples of phenoxy resin (A) include bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, bisphenol S type phenoxy resin, copolymer type phenoxy resin of bisphenol A and bisphenol F type (bisphenol AF type phenoxy resin), bisphenol E type phenoxy resin, naphthalene type phenoxy resin, novolac type phenoxy resin, biphenyl type phenoxy resin, cyclopentadiene type phenoxy resin, etc. Phenoxy resin (A) can be used alone or in combination of two or more types.

[0031] Examples of commercially available phenoxy resins (A) include jER4250 (manufactured by Mitsubishi Chemical Corporation, a mixed type of bisphenol A phenoxy resin / bisphenol F phenoxy resin, epoxy equivalent 7500-8900 g / eq), YX7200B35 (manufactured by Mitsubishi Chemical Corporation, phenoxy resin containing biphenyl and cyclohexane skeletons, epoxy equivalent: 9000 g / eq), 1256 (manufactured by Mitsubishi Chemical Corporation, phenoxy resin containing bisphenol A skeleton, epoxy equivalent: 7800 g / eq), and YX6954BH35 (manufactured by Mitsubishi Chemical Corporation, phenoxy resin containing bisphenolacetophenone skeleton, epoxy equivalent: 13000 g / eq).

[0032] 1-2. Liquid epoxy resin (B) Liquid epoxy resin (B) is an epoxy resin that is liquid at 20°C. Liquid epoxy resin (B) preferably contains a bifunctional epoxy resin having two or more epoxy groups in its molecule, and more preferably contains a polyfunctional epoxy resin having three or more epoxy groups in its molecule. A polyfunctional epoxy resin having three or more epoxy groups in its molecule has many reaction sites with, for example, resolphenol resin (D), and therefore generates many hydroxyl groups through ring-opening of the epoxy groups, making it particularly easy to enhance adhesion. Liquid epoxy resin (B) may be used alone or in combination of two or more types.

[0033] Furthermore, from the viewpoint of improving adhesive reliability, it is preferable that the liquid epoxy resin (B) has an aromatic ring.

[0034] Examples of liquid epoxy resins (B) having aromatic rings include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, cyclohexanedimethanol type epoxy resin having an aromatic structure, and epoxy resins having a butadiene structure having an aromatic structure, aminophenol type epoxy resin, etc. Among these, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, and phenol novolac type epoxy resin are more preferred, and phenol novolac type epoxy resin, which is a polyfunctional epoxy resin having three or more epoxy groups in its molecule, is even more preferred.

[0035] Examples of commercially available products include Mitsubishi Chemical's "828US," "jER828EL" (bisphenol A type epoxy resin), "jER806," "jER807" (bisphenol F type epoxy resin), "jER152" (phenol novolac type epoxy resin), "630," and "630LSD" (aminophenol type epoxy resin). These may be used individually or in combination of two or more types.

[0036] The epoxy equivalent of the liquid epoxy resin (B) is preferably less than 5000 g / eq, more preferably 50 to 3000 g / eq, and even more preferably 100 to 1000 g / eq. When the epoxy equivalent is within the above range, sufficient curing is possible without impairing the applicability of the primer composition. The epoxy equivalent can be measured by the same method as described above.

[0037] The weight-average molecular weight Mw of the liquid epoxy resin (B) is preferably 100 to 5000, more preferably 250 to 3000, and even more preferably 400 to 1500. The Mw of the liquid epoxy resin (B) is the weight-average molecular weight on a standard polystyrene basis, measured by GPC, as described above.

[0038] 1-3. Hardener The curing agent is a component that hardens the phenoxy resin (A) and / or the liquid epoxy resin (B).

[0039] Examples of curing agents for phenoxy resin (A) include compounds (isocyanates, melamine resins) that have a group that reacts with the hydroxyl group of phenoxy resin (A). Among these, melamine resin (C) is preferred from the viewpoint of high reactivity with phenoxy resin (A) and easy to increase the strength of the cured coating. Examples of curing agents for liquid epoxy resin (B) include polyaddition type epoxy resin curing agents. Among these, resolphenol resin (D) is preferred from the viewpoint of high reactivity with liquid epoxy resin (B) and easy to increase the adhesive strength of the cured product. Either one of these may be included, or both may be included.

[0040] 1-3-1. Melamine resin (C) Melamine resin (C) can react with the hydroxyl groups contained in phenoxy resin (A) and function as a curing agent to harden phenoxy resin (A). That is, melamine resin (C) reacts well with phenoxy resin (A) to form a crosslinked structure, which can further increase the coating strength of the cured product of the primer composition.

[0041] Such melamine resin (C) may be melamine, a methylolated melamine derivative obtained by condensing melamine with formaldehyde, a compound partially or completely etherified by reacting methylolated melamine with a lower alcohol, or a mixture thereof. Melamine resin (C) may be a monomer or a condensate consisting of two or more polymers.

[0042] Examples of lower alcohols used for etherification include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, and isobutanol. Specifically, the melamine resin (C) has functional groups such as an imino group, a methylol group, and alkoxymethyl groups such as a methoxymethyl group or a butoxymethyl group. Specifically, this includes imino-type methylated melamine resin, methylol-type melamine resin, methylol-type methylated melamine resin, and fully alkyl-type methylated melamine resin, with methylolated melamine resin being preferred.

[0043] Examples of commercially available melamine resin (C) include Nikalac MW-100LM, Nikalac MW-30, Nikalac MW-30M, Nikalac MW-22, Nikalac MW-22A, Nikalac MS-11, and Nikalac MX-750 from Sanwa Chemical Co., Ltd.; Cymel 300, Cymel 301, and Cymel 350 from Mitsui Cyanamid Co., Ltd.; and U-VAN 703 from Mitsui Chemicals, Inc. Melamine resin (C) may be used alone or in combination of two or more types.

[0044] In addition to the self-condensation of melamine resin (C), the reaction (curing reaction) between hydroxyl groups contained in phenoxy resin (A) and melamine resin (C) proceeds easily, further improving the coating strength of the cured product of the primer composition.

[0045] 1-3-2. Resolephenol resin (D) The resolphenol resin (D) can function as a polyaddition-type epoxy resin curing agent for liquid epoxy resin (B). That is, at least one of the phenolic OH group and methylol group of the resolphenol resin (D) can undergo an addition reaction with the epoxy group of the liquid epoxy resin (B). As a result, the liquid epoxy resin (B) can be sufficiently cured, thereby further increasing the coating strength of the cured primer composition. In addition, since hydroxyl groups can be generated by the ring-opening reaction of the epoxy group, the adhesive strength and reliability with insulating substrates can also be further increased.

[0046] Examples of resolphenol resins (D) include phenol type, cresol type, alkyl type, bisphenol A type, or copolymers thereof. Examples of commercially available resolphenol resins (D) include Phenolite TD-447 (manufactured by DIC Corporation, cresol type).

[0047] The total amount of melamine resin (C) and resolphenol resin (D) is preferably 50 to 80 parts by mass, and more preferably 60 to 70 parts by mass, relative to 100 parts by mass of the total amount of phenoxy resin (A) and liquid epoxy resin (B). If the above total amount is above the lower limit, the phenoxy resin (A) and liquid epoxy resin (B) are easily cured sufficiently, which further enhances the coating strength, adhesive strength, and adhesive reliability of the cured primer composition. If the above total amount is below the upper limit, the mixture does not harden excessively due to curing, which further suppresses the decrease in electroless plating reactivity.

[0048] The content ratio C / D of melamine resin (C) to resolphenol resin (D) is melamine resin (C) / resolphenol resin (D) = 0 / 100 to 100 / 0 (mass ratio), preferably 55 / 45 to 70 / 30 (mass ratio), and more preferably 60 / 40 to 65 / 35 (mass ratio). If the content ratio of melamine resin (C) is above a certain level, the phenoxy resin (A) is cured more easily, making it easier to increase the coating strength of the cured primer composition. If the content ratio of melamine resin (C) is below a certain level, the content ratio of resolphenol resin (D) is appropriate, making it less likely for the liquid epoxy resin (B) to cure poorly, and making it easier to maintain the adhesion and adhesive reliability of the cured primer composition.

[0049] 1-4. Other ingredients The primer composition of the present invention may further contain other components as needed.

[0050] 1-4-1. Palladium catalyst The primer composition of the present invention may further contain a palladium catalyst. The palladium catalyst is preferably in the form of palladium particles and can function as a nucleating agent for electroless plating. The palladium catalyst may be dispersed in a dispersant.

[0051] The average particle diameter of palladium particles is not particularly limited, but can be, for example, 2 to 10 nm. The average particle diameter of palladium particles can be calculated by measuring the diameters of any 10 particles using a transmission electron microscope and taking the number average of these measurements (as a number-based average diameter).

[0052] The palladium catalyst content is preferably 1 to 30% by mass, and more preferably 1 to 5% by mass, relative to the non-volatile components of the primer composition. When the palladium catalyst content is above a certain amount, the adhesion between the resulting primer layer and the electroless plating film is easily enhanced, while when it is below a certain amount, the coatability and dispersion stability are less likely to be impaired.

[0053] 1-4-2. Solvent The primer composition of the present invention may further contain a solvent (dispersion medium) for dispersing a palladium catalyst or the like. The solvent is preferably one that can disperse the palladium catalyst or its dispersion, and may be, for example, water or an aprotic polar solvent.

[0054] Examples of aprotic polar solvents include N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and γ-butyrolactone.

[0055] In addition, it may contain alcohols such as methanol and ethanol; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monobutyl ether; aromatic carboxylic acid esters such as methyl benzoate, ethyl benzoate, and methyl salicylate; aromatic hydrocarbons such as toluene and xylene; glycol ether esters such as methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, methyl carbitol acetate, and butyl carbitol acetate; and alkanol esters such as ethyl acetate and butyl acetate.

[0056] 1-4-3. Silica particles If the primer composition of the present invention contains a palladium catalyst, the primer composition may further contain silica particles. The silica particles may primarily function to enhance the stability of the palladium catalyst.

[0057] As silica particles, in addition to untreated silica particles, hydrophilic silica particles and hydrophobic silica particles can be used. The shape of the silica particles is not limited and may be spherical silica or crushed silica.

[0058] Among silica particles, hydrophobic silica particles are preferred because they easily suppress aggregation between silica particles and further enhance the dispersion stability of the palladium catalyst. Hydrophobic silica particles are obtained by surface treatment of silica particles. As surface treatment agents for silica particles, for example, silane coupling agents such as β-ethyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane, or treatment agents such as silicone oil can be used. Examples of hydrophobic silica particles include organosilica sols such as methanol silica, IPA-ST, NPC-ST-30, MEK-ST, PMA-ST, and MIBK-ST manufactured by Nissan Chemical Industries, Ltd.

[0059] The average particle diameter of silica particles is preferably 10 to 100 nm, more preferably 10 to 50 nm. The average particle diameter can be measured by the cumulant method using a dynamic light scattering measuring instrument. Alternatively, it can be measured using a transmission electron microscope and calculated as the number-based average diameter.

[0060] The silica particle content is not particularly limited, but can be, for example, 1 to 30% by mass relative to the non-volatile components of the primer composition. This can further enhance the stability of the palladium catalyst.

[0061] 1-5. Manufacturing method The primer composition of the present invention can be prepared by any method, for example, by mixing the above components.

[0062] The palladium catalyst may be added in particulate form or in a dispersed state (as a dispersion) using a dispersant.

[0063] 2. Laminate The laminate of the present invention includes an insulating substrate, a base pattern, and a metal plating pattern.

[0064] 2-1. Insulating substrate The insulating substrate may be a resin substrate or an inorganic substrate such as glass. Among these, a resin substrate is preferred from the viewpoint of applications where flexibility is required.

[0065] The types of materials constituting the resin substrate are not particularly limited and include polyester, (meth)acrylic resin, polycarbonate, polystyrene, polyvinyl chloride, polyamide, polyimide (e.g., MPI), polyetherimide, polyacetal, polyetheretherketone (PEEK), cyclic polyolefin (COC), polyolefin, polyphenylene sulfide (PPS), polysulfone, phenolic resin, liquid crystalline polymer (LCP), etc. Among these, transparent substrates are preferred, and transparent film substrates are more preferred, from the viewpoint of use in display devices and touch panels.

[0066] The thickness of the insulating substrate is not particularly limited, but can be, for example, 12.5 to 50 μm.

[0067] 2-2. Base Pattern The base pattern is a layer containing cured products of the primer composition of the present invention, arranged in a pattern on an insulating substrate. The base pattern has the function of holding a palladium catalyst that acts as a reaction nucleus with the electroless plating solution, and also enhances the adhesion between the electroless plating pattern (metal plating pattern) and the insulating substrate.

[0068] The thickness of the base pattern is not particularly limited as long as sufficient adhesive strength is ensured between the metal plating pattern and the insulating substrate, but it is preferable that it be thinner than the thickness of the metal plating pattern. In particular, since the cured product of the primer composition of the present invention exhibits good adhesive strength, the thickness of the base pattern can be made sufficiently thin. Specifically, the thickness of the base pattern can be, for example, 0.05 to 0.5 μm.

[0069] 2-3. Metal Plating Patterns A metal plating pattern is a plating layer obtained by placing it on a base pattern and bringing the surface of the base pattern into contact with an electroless plating solution. The metal plating pattern includes metals such as copper, platinum, gold, silver, nickel, chromium, cobalt, and tin. Preferably, the metal plating pattern includes a metal selected from the group consisting of copper, platinum, gold, silver, and nickel, and more preferably, it includes copper or an alloy thereof.

[0070] The thickness of the metal plating pattern can be set appropriately depending on the application, but for example, when used in printed circuit boards, it may be 0.01 to 50 μm, preferably 0.1 to 10 μm, and more preferably 0.1 to 2 μm.

[0071] The laminate of the present invention can be used in circuit formation substrates used in electronic circuits, integrated circuits, etc., organic EL elements, organic transistors, flexible printed circuit boards, RFID, touch panels, etc., as well as transparent electrode substrates (including transparent electrode film substrates). In particular, the metal plating pattern obtained using the primer composition of the present invention has good flexibility and high conductivity, and can therefore be suitably used, for example, in flexible printed circuit boards (FPCs) and transparent electrode film substrates.

[0072] 3. Method for manufacturing the laminate The laminate of the present invention can be manufactured by the following steps: 1) applying a pattern of the primer composition of the present invention to an insulating substrate; 2) curing the pattern of the primer composition to form a base pattern; and 3) applying electroless plating to the surface of the base pattern to form a metal plating pattern.

[0073] 1) Step (Patterning step of the primer composition) In this process, a pattern of the primer composition is directly formed on an insulating substrate without etching. This method is also known as the pure additive method.

[0074] The method for applying the pattern is not particularly limited and may be any of flexographic printing, gravure offset printing, adhesion contrast printing, or inkjet printing. Among these, adhesion contrast printing is preferred from the viewpoint of easily forming a fine-pitch pattern.

[0075] Figures 1A to 1C are schematic diagrams showing the process of applying patterns to primer compositions using the adhesion contrast printing method. Figures 2A and 2B are schematic diagrams showing the preparation process for the adhesion contrast plate 20 used in Figures 1A to 1C.

[0076] As shown in Figure 1, the pattern 30' of the primer composition can be directly formed on the insulating substrate 40 by a) step of bringing a coating film 30 of the primer composition applied to the support 10 into contact with an adhesion contrast plate 20 (plate) to obtain a pattern 30' of the primer composition (Figures 1A and 1B), and b) transferring the pattern 30' of the primer composition onto the insulating substrate 40 (Figure 1C).

[0077] In step a), the primer composition is applied to the blanket 11 of the support 10, for example, by a slit die 50. The applied primer composition is dried to at least a semi-dry state (see Figure 1A).

[0078] Next, the obtained primer composition coating 30 is brought into contact with the adhesion contrast plate 20 (see Figure 1B). Specifically, the primer composition coating 30 is sandwiched between the support 10 and the adhesion contrast plate 20, and pressure is applied.

[0079] The adhesion contrast plate 20 has a portion 21 on its surface that has relatively high adhesion to the primer composition and a portion 22 that has relatively low adhesion (see Figure 2B). The coating film of the primer composition on the support 10 is brought into contact with the adhesion contrast plate 20, and a portion of the coating film 30 of the primer composition is selectively (patternly) removed to form a pattern 30' (see Figure 1B).

[0080] The adhesion contrast plate 20 can be obtained, for example, by placing a mask pattern (quartz chromium mask) 80 on the surface of a silicone rubber sheet 70 and irradiating it with light from an excimer lamp L through the mask pattern 80. In this embodiment, the irradiated area 21 is the area where the adhesion of the primer composition is relatively high; the unirradiated area 22 is the area where the adhesion of the primer composition is relatively low.

[0081] As described above, the primer composition of the present invention contains a phenoxy resin (A) and a liquid epoxy resin (B) in a predetermined ratio. As a result, upon contact with the adhesion contrast plate 20, the portion of the primer composition coating film 30 corresponding to the irradiation area 21 of the adhesion contrast plate 20 (the portion with high adhesion) is removed, and the pattern 30' of the primer composition is formed (see Figure 1B).

[0082] In step b), the pattern 30' of the obtained primer composition is transferred to the insulating substrate 40 (see Figure 1C).

[0083] 2) Step (Curing step of the primer composition) Next, the pattern of the primer composition applied to the insulating substrate is cured. This results in a substrate pattern containing the cured primer composition.

[0084] Curing is preferably by thermal curing. The heating temperature should be sufficient to allow the curing reaction of the phenoxy resin (A) and liquid epoxy resin (B) in the primer composition to proceed sufficiently, for example, 60 to 400°C, preferably 80 to 150°C. The heating time depends on the heating temperature, but for example, it can be about 0.1 to 60 minutes, preferably 10 to 30 minutes.

[0085] 3) Step (Metal plating pattern formation step) Then, the surface of the underlay pattern on the insulating substrate is brought into contact with the electroless plating solution to form an electroless plating film (metal plating pattern).

[0086] From the viewpoint of efficiently performing electroless plating, it is preferable that a palladium catalyst be present on the surface of the base pattern. As described above, the palladium catalyst may be pre-included in the primer composition constituting the base pattern, or it may be applied by contacting the surface of the base pattern with a solution containing the palladium catalyst. From the viewpoint of effectively increasing the reactivity with the electroless plating solution, it is preferable that the palladium catalyst be pre-included in the primer composition.

[0087] The electroless plating solution may contain the above-mentioned metal, a reducing agent, and water and / or a water-soluble organic solvent. The conditions for electroless plating can be set according to the composition of the electroless plating solution. For example, the temperature of the electroless copper plating bath can usually be around 25 to 45°C. The processing time depends on the application, but for example, when forming a metal plating layer with a thickness of about 0.3 to 0.4 μm, it can be about 10 to 20 minutes.

[0088] Thus, because the primer composition of the present invention has appropriate coating strength, it can be transferred to the adhesion contrast plate according to the pattern on the adhesion contrast plate. This allows a fine-pitch base pattern to be directly formed on the insulating substrate (step 1 above). Furthermore, because the cured product of the primer composition is not too hard, it exhibits excellent reactivity with electroless plating solutions in the presence of a palladium catalyst. This allows a plating pattern of appropriate thickness to be directly formed without etching (step 3 above). This enables the formation of a fine-pitch metal plating pattern by the pure additive method. Also,

[0089] Furthermore, by using the primer composition of the present invention, it is possible to form wiring patterns with good flexibility and high conductivity. As a result, the laminate of the present invention can be suitably used in applications where flexibility and high conductivity are required, as described above.

[0090] In the above embodiment, the step in 1) above was shown as being performed by the adhesion contrast printing method, but it is not limited to this and may be performed by other methods such as the graft offset printing method. In that case, the primer composition of the present invention has a moderately low viscosity, making it easy to apply in a predetermined pattern. Furthermore, the coating film of the applied primer composition has a moderate film strength, making it easy to maintain the film shape. Therefore, a primer composition in a predetermined pattern can be directly formed on an insulating substrate. [Examples]

[0091] The present invention will be described in more detail below with reference to examples. However, the scope of the present invention is not limited in any way thereto.

[0092] 1. Materials of the primer composition <Material> (1) Base resin • jER4250 (manufactured by Mitsubishi Chemical Corporation, mixed type of bisphenol A phenoxy resin / bisphenol F phenoxy resin, secondary hydroxyl group equivalent: 270 g / eq, epoxy equivalent: 7500-8900 g / eq, Mw: 60,000) • Teisaresin SG-80H (manufactured by Nagase ChemteX Corporation, acrylic acid ester / glycidyl methacrylate / acrylonitrile copolymer, epoxy equivalent 9100 g / eq, Mw: 350,000, Tg: 11℃) • Urethane-modified polyester copolymer (manufactured by Toyobo Co., Ltd., Byron UR-3200)

[0093] (2) Liquid epoxy resin (B) • jER152 (manufactured by Mitsubishi Chemical Corporation, phenol novolac type epoxy resin, epoxy equivalent 176-177 g / eq)

[0094] (3) Melamine resin (C) • U-VAN 703 (manufactured by Mitsui Chemicals, melamine resin)

[0095] (4) Resolephenol resin (D) • Phenolite TD-447 (manufactured by DIC Corporation, resol-type phenolic curing agent, cresol-modified type)

[0096] (5) Palladium catalyst • Pd nanopowder (ML-001N manufactured by Iox Corporation, average particle size 5nm)

[0097] (6) Silica particles (catalyst stabilizer) • PMA-ST (manufactured by Nissan Chemical Corporation, silica particles, average particle size 12 nm)

[0098] 2. Preparation and evaluation of primer compositions [Examples 1-3, Comparative Examples 1-6] (Preparation of primer composition) A primer composition was prepared by mixing each component to achieve the composition shown in Table 1.

[0099] (Patterning of primer composition) The prepared primer composition was applied to the blanket 11 of the support 10 and then dried at room temperature (25°C) for 1 minute (see Figure 1A). Next, the semi-dry coating 30 of the primer composition applied to the blanket 11 was brought into contact with the adhesion contrast plate 20 to obtain a pattern 30' of the primer composition (see Figure 1B). Then, the pattern 30' of the primer composition formed on the blanket 11 was transferred onto a transparent film, a polyimide film (insulating substrate 40) (see Figure 1C).

[0100] (Curing of the primer composition) The pattern 30' of the primer composition transferred onto the transparent film was heated at 150°C for 3 minutes to cure it. This resulted in a base pattern (a layer of cured primer composition) with a thickness of 0.5 μm.

[0101] (Electroless plating) Then, the transparent film with the base pattern formed on it was immersed in an electroless plating bath and electroless plating was performed. The electroless copper plating bath used was Sulcup PSY (Cu concentration 2-3 g / L) manufactured by Uemura Kogyo Co., Ltd. Electroless plating was performed at 35°C for 10 minutes, and the plating thickness was 0.2 μm.

[0102] [evaluation] The printability of the primer composition, electroless plating reactivity, metal mesh wiring formation ability, and adhesion of the plating pattern in the laminate fabrication process were evaluated using the following methods.

[0103] (1) Printability by adhesion contrast printing method The coating state of the primer composition transferred onto a transparent film was observed using an optical microscope over a 100 mm x 40 mm measurement area. The printability was then evaluated based on the following criteria. ○: Printing correctly according to the pattern. △: There are 5 or fewer areas where printing failed (disconnected wires) within the measurement area, but the pattern is generally printed correctly. ×: There are more than 5 areas where printing failed (disconnections) within the measurement area, meaning the pattern was not printed correctly. The above evaluation comprehensively assesses the applicability of the primer composition to the blanket, its transferability to the adhesion contrast plate, and its printability on the transparent film. A score of △ or higher was considered good.

[0104] (2) Reactivity of electroless Cu plating The sheet resistance of the surface of the plated layer (plating pattern) obtained by electroless plating was measured using a surface resistance meter. Then, the electroless Cu plating reactivity was evaluated based on the following criteria. ○: Sheet resistance value is 0.25Ω / □ or less △: Sheet resistance value greater than 0.25Ω / □ and less than or equal to 0.9Ω / □ ×: Sheet resistance value exceeds 0.9Ω / □ If the result is △ or higher, it is determined that a uniform plating pattern can be formed and that the electroless plating reactivity is good.

[0105] (3) Cu metal mesh wiring formability The appearance of the plating pattern obtained by electroless plating was observed using an optical microscope over a measurement area of ​​100 mm × 40 mm and evaluated based on the following criteria. ○: No broken wires △: 5 or fewer broken points ×: There are more than 5 broken points. If the result is △ or higher, it is judged that there are few broken wires and the wiring can be formed well.

[0106] (4) Adhesiveness (Initial adhesion) The adhesion of the plating pattern on the resulting laminate was measured using a 90° peel test. The measurement was performed at room temperature with a peel speed of 25 mm / min. An adhesive strength of 5 N / cm or higher was considered good.

[0107] (Adhesion reliability) The resulting laminate was stored in an atmospheric oven at 150°C for 168 hours. Subsequently, the adhesive strength of the plating pattern was evaluated using the same method and criteria as described above.

[0108] The evaluation results of the primer compositions of Examples 1-3 and Comparative Examples 1-6 are shown in Table 1.

[0109] [Table 1]

[0110] As shown in Table 1, the primer compositions of Examples 1 to 3, which contain at least phenoxy resin (A) and liquid epoxy resin (B) in a predetermined ratio, exhibit high printability on adhesion contrast plates. Furthermore, the cured products show good reactivity with electroless plating solutions, enabling the formation of high-resolution metal mesh wiring. The adhesion of the plating patterns is also good.

[0111] In contrast, the primer compositions of Comparative Example 1, which had too much liquid epoxy resin (B), and Comparative Example 2, which had too little, both exhibited poor printability on the adhesion contrast plate and poor metal mesh wiring formation by electroless plating. Specifically, in Comparative Example 1, the high proportion of liquid epoxy resin (B) resulted in excessively low coating strength in the semi-dry state, causing delamination during transfer to the adhesion contrast plate. As a result, the pattern could not be transferred according to the adhesion contrast plate. On the other hand, in Comparative Example 2, the low proportion of liquid epoxy resin (B) resulted in excessively high coating strength in the semi-dry state, causing almost no transfer to the adhesion contrast plate, and thus the pattern could not be transferred according to the adhesion contrast.

[0112] Furthermore, it was found that the primer compositions of Comparative Examples 3 to 6, which used acrylic resin instead of phenoxy resin (A), had poor printability on the adhesion contrast plate. Specifically, the primer composition of Comparative Example 3 had too high a coating strength in the semi-dry state, making transfer to the adhesion contrast plate impossible. The primer composition of Comparative Example 5 had poor applicability on the blanket in the first place, and therefore could not be transferred to the adhesion contrast plate. [Industrial applicability]

[0113] According to the present invention, a primer composition for electroless plating is provided that enables the formation of a plating pattern of appropriate thickness without etching. The plating pattern obtained using this composition has good flexibility and conductivity, and is therefore particularly suitable for flexible printed circuit boards (FPCs) and transparent electrode film substrates. [Explanation of Symbols]

[0114] 10 Support 11 Blankets 20 Adhesion contrast plate (plate) 21 Irradiation area 22 Non-irradiated area 30. Coating film of primer composition Pattern of 30' primer composition 40 Insulating substrate 50 Slit Dies 60 Removal section 70 Silicone rubber sheets 80 Mask Patterns L Excimer Lamp

Claims

1. It contains phenoxy resin (A), liquid epoxy resin (B), a curing agent, and palladium particles. The content ratio A / B of the phenoxy resin (A) and the liquid epoxy resin (B) is 20 / 80 to 40 / 60 (by mass). Primer composition for electroless plating.

2. The liquid epoxy resin (B) is a polyfunctional epoxy resin having two or more epoxy groups in its molecule. The electroless plating primer composition according to claim 1.

3. The curing agent comprises melamine resin (C), The electroless plating primer composition according to claim 1 or 2.

4. The curing agent comprises a resolphenol resin (D), A primer composition for electroless plating according to any one of claims 1 to 3.

5. Further containing silica particles, A primer composition for electroless plating according to any one of claims 1 to 4.

6. Insulating substrate and A base pattern disposed on the insulating substrate, comprising a cured product of the electroless plating primer composition according to any one of claims 1 to 5, A metal plating pattern placed on the aforementioned base pattern and including, Laminated structure.

7. The insulating substrate is a transparent substrate. The laminate according to claim 6.

8. A step of applying a pattern of an electroless plating primer composition to an insulating substrate, the composition comprising a phenoxy resin (A), a liquid epoxy resin (B), and a curing agent, wherein the content ratio A / B of the phenoxy resin (A) to the liquid epoxy resin (B) is 20 / 80 to 40 / 60 (by mass ratio), A step of curing the pattern of the primer composition to form a base pattern. A step of forming a metal plating pattern by applying electroless plating to the surface of the aforementioned base pattern, including, A method for manufacturing laminates.

9. The step of imparting a pattern to the primer composition is: A step of obtaining a pattern of the primer composition by bringing the coating film of the primer composition formed on the support into contact with a plate, A step of transferring the pattern of the primer composition onto the insulating substrate. including, A method for manufacturing a laminate according to claim 8.

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