JP7336881B2 - Coated substrate having thermosetting composition and its cured coating - Google Patents

Description

The present invention relates to thermosetting compositions and coated substrates having cured coatings thereof, and more particularly to thermosetting compositions for application to high melting point substrates and coated substrates having cured coatings thereof.

In the past, conductor patterns were formed on planar substrates such as copper clad laminates, glass substrates, ceramic substrates, and wafer plates using paper phenol, paper epoxy, etc., but liquid crystal polymer (LCP), polyether ether ketone ( PEEK), polyphenylene sulfide (PPS), and other high-temperature thermoplastic super engineering plastics have heat resistance that can withstand the heat of the reflow process when mounting parts on printed wiring boards. The use of the three-dimensional molded product as a base material for circuit formation has been studied. A three-dimensional circuit-molded component in which a circuit is formed on a base material of a three-dimensional molded product and components are mounted is called an MID (Molded Interconnect Device).

Patent Document 1 discloses an invention relating to a substrate for MID, in which a three-dimensional molding of a heat-resistant thermoplastic resin such as liquid crystal polymer (LCP) or polyetheretherketone (PEEK) is coated with a thermosetting resin such as epoxy resin. is disclosed.

According to the MID using the substrate of Patent Document 1, since a circuit can be formed on the surface of a small and complicated three-dimensional molded product, it is possible to manufacture electronic components that meet the trend of lightness, thinness, shortness and smallness.

JP 2018-115355 A

However, super engineering plastics such as liquid crystal polymer (LCP) and polyether ether ketone (PEEK) have a high glass transition point (Tg) and a low coefficient of thermal expansion (CTE). The inventors' studies have revealed that the solder resist film formed due to the difference in CTE may peel off when applied to the surface of engineering plastics. It is considered that this is also caused by the hardness of the coating film, which cannot absorb shrinkage due to the difference in CTE.

In general, when the CTE difference between the substrate and the resin composition coated on the substrate becomes a problem, the CTE difference is suppressed by increasing the amount of the inorganic filler in the resin composition. However, no study has been made on the case of using a material with a high melting point such as a super engineering plastic as the base material.

The present invention has been made in view of the above problems, and an object of the present invention is to solve the problem of peeling of the coating film when applied to a high melting point substrate. and a coated substrate obtained by applying a surface coating layer of a thermosetting composition on a high melting point substrate.

The inventors of the present invention conducted intensive studies to achieve the above object. As a result, by blending aluminum oxide and a block copolymer having a polymer block mainly composed of methacrylic acid ester units in a predetermined proportion into a thermosetting composition, it was found that the peeling of the coating film from the high-melting-point substrate was reduced. We have found that the problem has been solved, and have completed the present invention.

That is, the above object of the present invention is
A thermosetting composition for application to a high-melting substrate having a melting point of 270° C. or higher,
(A) a thermosetting component;
(B) aluminum oxide particles;
(C) the following formula (I) or the following formula (II)
XYX (I) or XYX' (II)
(In the formula, X and X′ are polymer blocks mainly composed of methacrylate units having a glass transition point Tg of 0° C. or higher, and Y is mainly composed of acrylic ester units having a glass transition point Tg of less than 0° C. is a polymer block that
wherein the mass percentage of the sum of X and X' relative to the total mass of the acrylic block copolymer is in the range of 12% by mass or more and 35% by mass or less. a block copolymer;
It has been found that this is achieved by a thermosetting composition characterized by comprising:

In the thermosetting composition of the present invention, (C) the acrylic block copolymer preferably has a weight average molecular weight of 65,000 or more and 80,000 or less.

In addition, (C) the acrylic block copolymer is preferably an acrylic block copolymer represented by the formula (I), in which X is mainly composed of methyl methacrylate units. It is more preferable that Y is a polymer block mainly composed of n-butyl acrylate units.

Moreover, the amount of (B) aluminum oxide particles is preferably 40% by mass or more and 90% by mass or less with respect to the total mass of the thermosetting composition.

Furthermore, the amount of (C) the acrylic block copolymer is preferably 0.5% by mass or more and 20% by mass or less with respect to the total mass of the thermosetting composition.

Also preferably, the high melting point substrate is selected from the group consisting of liquid crystal polymers, polyphenylene sulfides and polyetheretherketones.

The above objects of the present invention can also be achieved by a coated substrate characterized by having a cured coating of the thermosetting composition of the present invention.

According to the present invention, when a thermosetting composition is applied to a high-melting-point substrate, cracking of the resulting cured coating can be suppressed, and the problem of peeling of the cured coating from the high-melting-point substrate can be solved. can be resolved.

<Thermosetting composition>
The thermosetting composition of the present invention is a thermosetting composition for application to a high melting point substrate having a melting point of 270° C. or higher,
(A) a thermosetting component;
(B) aluminum oxide particles;
(C) the following formula (I) or the following formula (II)
XYX (I) or XYX' (II)
(In the formula, X and X′ are polymer blocks mainly composed of methacrylate units having a glass transition point Tg of 0° C. or higher, and Y is mainly composed of acrylic ester units having a glass transition point Tg of less than 0° C. is a polymer block that
wherein the mass percentage of the sum of X and X' relative to the total mass of the acrylic block copolymer is in the range of 12% by mass or more and 35% by mass or less. a block copolymer;
including.

The thermosetting composition of the present invention is used for coating high melting point substrates having a melting point of 270° C. or higher.

Regarding the base material, since it is necessary to withstand the heat when a conductive pattern is formed and then components are mounted by reflow soldering or flow soldering, the base material should be 270° C. or higher, preferably 300° C. or higher, and particularly preferably 330° C. A high-melting-point base material having a melting point equal to or above is used.

In the present invention, the melting point (melting temperature) of the high melting point base material means the temperature measured according to JIS K 7121 using a differential scanning calorimeter.

Materials for the high-melting base material having a melting point of 270° C. or higher include polyetheretherketone, liquid crystal polymer, and polyphenylene sulfide. An inorganic filler may be added to these materials, or they may be used in combination with glass cloth. Examples of inorganic fillers include fibrous inorganic fillers such as glass fiber and carbon fiber, short fibrous fillers (whiskers such as silicon carbide, silicon nitride and zinc oxide), and plate-like inorganic fillers such as talc and mica.

When a fibrous inorganic filler is added, it is preferable that the fiber diameter is in the range of 6-15 μm and the aspect ratio is in the range of 5-60. When plate-like inorganic fillers are used, the plate-like inorganic fillers have an average length of 1 to 80 μm, preferably 1 to 50 μm, and an average aspect ratio (length/thickness) of 2 to 60, preferably 10 to 40. It is preferred to have

The fibrous inorganic fillers, short fibrous fillers (whiskers), and plate-like inorganic fillers may be used alone, or two or more of them may be used in combination. Also, a powdery or needle-like inorganic filler may be added. Further, as a coloring agent, carbon black or the like may be added to the high-melting-point base material having a melting point of 270° C. or higher.

Among them, it is preferable to use a liquid crystal polymer as a material for the high melting point base material having a melting point of 270° C. or higher from the viewpoint of moldability, electrical properties, and chemical resistance.

The liquid crystalline polymer used in the high-melting base material of the present invention is a polyester or polyester amide that forms an anisotropic melt phase, and is particularly limited as long as it is called a thermotropic liquid crystalline polyester or a thermotropic liquid crystalline polyester amide in the technical field. no.

The nature of the anisotropic melt phase can be confirmed by conventional polarimetry using crossed polarizers. Specifically, the anisotropic molten phase can be confirmed by using a Leitz polarizing microscope and observing a sample placed on a Leitz hot stage under a nitrogen atmosphere at a magnification of 40 times. The liquid crystal polymer used in the high melting point substrate of the present invention is optically anisotropic, that is, it transmits light when tested with crossed polarizers. If the sample is optically anisotropic, polarized light is transmitted even at rest.

Examples of polymerizable monomers constituting the liquid crystal polymer include aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic aminocarboxylic acids, aromatic hydroxylamines, aromatic diamines, aliphatic diols and aliphatic diols. Dicarbones may be mentioned. The liquid crystal polymer may be a homopolymer of one of these polymerizable monomers, or may be a copolymer of two or more polymerizable monomers. and a polymerizable monomer having a carboxyl group as a constituent.

The polymerizable monomer that constitutes the liquid crystal polymer may be an oligomer in which one or more of the compounds exemplified above are combined.

As the liquid crystal polymer, a liquid crystal polyester resin containing repeating units represented by formula (a) and/or formula (b), or a wholly aromatic liquid crystal composed of the same repeating units is used in terms of excellent fluidity and mechanical properties. A polyester resin can be preferably used.

The thermosetting composition of the present invention is particularly preferably used when the high-melting-point substrate is an injection-molded substrate on which a conductor pattern is formed. When a three-dimensional injection-molded high-melting-point base material is used as a base material for forming a conductor pattern, the high-melting-point base material is required to maintain rigidity even when heated to a high temperature.

Specifically, the high melting point base material conforms to ASTM D648 (1.82 MPa) (standard number of ASTM standard, which is a standard formulated and published by ASTM International (formerly American Society for Testing and Materials)). Deflection temperature (DTUL) under load is 140° C. or higher and 350° C. or lower, preferably 180° C. or higher and 310° C. or lower, and particularly preferably 200° C. or higher and 290° C. or lower.

When the deflection temperature under load of the high-melting-point base material is 140° C. or higher and 350° C. or lower, the base material is not deformed during heating for soldering, and can be easily molded.

An example of specific measurement of deflection temperature under load (DTUL) is shown below, taking the case of a liquid crystal polymer as an example.

Using an injection molding machine (manufactured by Nissei Plastic Industry Co., Ltd., UH1000-110), injection molding is performed at a cylinder temperature of crystal melting temperature +20 to 40 ° C. and a mold temperature of 70 ° C., and a strip-shaped test piece (length 127 mm x width 12 .7 mm x 3.2 mm thick). Using this, in accordance with ASTM D648, a load of 1.82 MPa and a temperature increase rate of 2° C./min are used to measure the temperature at which a predetermined amount of deflection (0.254 mm) is achieved.

Commercially available high-melting base materials having a melting point of 270° C. or higher and a deflection temperature under load of 140° C. or higher and 350° C. or lower include Vectra (registered trademark) E841iLDS and Vectra (registered trademark) E840iLDS (above, ceramic Needs Japan), TECACOMP (registered trademark) LCP LDS black 4107 (manufactured by Ensinger), RTP 3499-3 X 113393A (manufactured by RTP), and the like. Moreover, the high-melting-point substrate having a melting point of 270° C. or higher and a deflection temperature under load of 140° C. or higher and 350° C. or lower is also commercially available from Ueno Pharmaceutical Co., Ltd.

[(A) thermosetting component]
A thermosetting component is a compound added to thermally cure the thermosetting composition of the present invention.

Thermosetting components used in the present invention include melamine resins, amine resins such as benzoguanamine resins, polyisocyanate compounds, blocked isocyanate compounds, cyclocarbonate compounds, polyfunctional epoxy compounds, polyfunctional oxetane compounds, episulfide resins, melamine derivatives, Known and commonly used thermosetting resins such as benzoguanamine derivatives, bismaleimide, oxazine compounds, oxazoline compounds and carbodiimide compounds can be used. Thermosetting components having a plurality of cyclic ether groups or cyclic thioether groups (hereinafter abbreviated as "cyclic (thio)ether groups") in the molecule are particularly preferred.

Such a thermosetting component having a plurality of cyclic (thio)ether groups in the molecule includes either one or two types of 3-, 4- or 5-membered cyclic ether groups or cyclic thioether groups in the molecule. is a compound having a plurality of, for example, compounds having multiple epoxy groups in the molecule, i.e. polyfunctional epoxy compounds, compounds having multiple oxetanyl groups in the molecule, i.e. polyfunctional oxetane compounds, multiple thioether groups in the molecule and episulfide resins.

As the polyfunctional epoxy compound, jER828, jER834, jER1001, jER1004 manufactured by Mitsubishi Chemical Corporation, EHPE3150 manufactured by Daicel Chemical Industries, Ltd., EPICLON 840 manufactured by DIC Corporation, EPICLON 850, EPICLON 1050, EPICLON 2055 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Epotote YD-011, YD-013, YD-127, YD-128, Dow Chemical Company D.I. E. R. 317, D. E. R. 331, D. E. R. 661, D. E. R. 664, Huntsman Japan's Araldite 6071, Araldite 6084, Araldite GY250, Araldite GY260, Sumiepoxy ESA-011, ESA-014, ELA-115, ELA-128, etc. (all trade names) manufactured by Sumitomo Chemical Co., Ltd. Bisphenol A type epoxy resin; jERYL903 manufactured by Mitsubishi Chemical Corporation, EPICLON 152 and EPICLON 165 manufactured by DIC Corporation, Epotote YDB-400 and YDB-500 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., D.I. E. R. 542, Araldite 8011 manufactured by Huntsman Japan, brominated epoxy resins such as Sumiepoxy ESB-400 and ESB-700 manufactured by Sumitomo Chemical Co., Ltd. (both trade names); jER152 and jER154 manufactured by Mitsubishi Chemical, and manufactured by Dow Chemical. of D. E. N. 431, D. E. N. 438, EPICLON N-730, EPICLON N-770, EPICLON N-865 manufactured by DIC, Epotote YDCN-701, YDCN-704 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Araldite ECN1235, Araldite ECN1273, Araldite ECN1299 manufactured by Huntsman Japan, Araldite XPY307, Nippon Kayaku EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306, NC-3000, Sumitomo Chemical Co., Ltd. Sumiepoxy ESCN-195X, ESCN-220, ECN- 235, ECN-299, etc. (all trade names); EPICLON 830 manufactured by DIC Corporation, jER807 manufactured by Mitsubishi Chemical Corporation, Epotote YDF-170, YDF-175, YDF-2004 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; Bisphenol F-type epoxy resins such as Araldite XPY306 (all trade names) manufactured by Huntsman Japan; Epoxy resin; jER604 manufactured by Mitsubishi Chemical Corporation, Epotote YH-434 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Araldite MY720 manufactured by Huntsman Japan, Sumiepoxy ELM-120 manufactured by Sumitomo Chemical Co., Ltd., glycidylamine type (all are trade names) Epoxy resin; hydantoin-type epoxy resin such as Araldite CY-350 (trade name) manufactured by Huntsman Japan; Celoxide 2021 manufactured by Daicel Chemical Industries, Ltd.; Cyclic epoxy resin; YL-933 manufactured by Mitsubishi Chemical Co., Ltd., EPPN-501, EPPN-502 manufactured by Nippon Kayaku Co., Ltd. (both trade names) trihydroxyphenylmethane type epoxy resin; YL- manufactured by Mitsubishi Chemical Co., Ltd. 6056, YX-4000, YL-6121 (all trade names) bixylenol type or biphenol type epoxy resins or mixtures thereof; Nippon Kayaku EBPS-200, ADEKA EPX-30, DIC Bisphenol S type epoxy resin such as EXA-1514 (trade name); Bisphenol A novolac type epoxy resin such as jER157S (trade name) manufactured by Mitsubishi Chemical Corporation; YL-931 manufactured by Mitsubishi Chemical Corporation, Araldite 163 manufactured by Huntsman Japan Co., Ltd. etc. (both are trade names); Araldite PT810 (trade name) manufactured by Huntsman Japan; Heterocyclic epoxy resins such as TEPIC (registered trademark) manufactured by Nissan Chemical; Blemmer (registered trademark) DGT and other diglycidyl phthalate resins; Nippon Steel & Sumikin Chemical Co., Ltd. ZX-1063 and other tetraglycidyl xylenoyl ethane resins; Nippon Steel & Sumikin Chemical Co., Ltd. ESN-190, ESN-360, DIC HP-4032 , EXA-4750, naphthalene group-containing epoxy resins such as EXA-4700; HP-7200 manufactured by DIC, epoxy resins having a dicyclopentadiene skeleton such as HP-7200H; CP-50S manufactured by NOF Corporation, such as CP-50M Glycidyl methacrylate copolymer epoxy resin; further copolymer epoxy resin of cyclohexyl maleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivative (eg PB-3600 manufactured by Daicel Chemical Industries, etc.), CTBN-modified epoxy resin (eg Nippon Steel & Sumikin Chemical Co., Ltd.) (YR-102, YR-450, etc.), but not limited to these. These epoxy resins can be used alone or in combination of two or more.

Examples of the polyfunctional oxetane compound include bis[(3-methyl-3-oxetanylmethoxy)methyl]ether, bis[(3-ethyl-3-oxetanylmethoxy)methyl]ether, 1,4-bis[(3-methyl -3-oxetanylmethoxy)methyl]benzene, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, (3-methyl-3-oxetanyl)methyl acrylate, (3-ethyl-3-oxetanyl ) In addition to polyfunctional oxetanes such as methyl acrylate, (3-methyl-3-oxetanyl)methyl methacrylate, (3-ethyl-3-oxetanyl)methyl methacrylate and their oligomers or copolymers, oxetane alcohols and novolak resins, Examples thereof include poly(p-hydroxystyrene), cardo-type bisphenols, calixarenes, calixresorcinarenes, and etherified products with resins having a hydroxyl group such as silsesquioxane. Other examples include copolymers of unsaturated monomers having an oxetane ring and alkyl (meth)acrylates.

Examples of the compound having a plurality of cyclic thioether groups in the molecule include bisphenol A episulfide resin YL7000 manufactured by Mitsubishi Chemical Corporation. Also, an episulfide resin obtained by replacing the oxygen atom of the epoxy group of the novolac type epoxy resin with a sulfur atom by using a similar synthesis method can be used.

(A) The thermosetting component is blended in the range of 1% by mass to 10% by mass, preferably 1% by mass to 5% by mass, based on the total mass (solid content) of the thermosetting composition. be. (A) By setting the thermosetting component in the range of 1% by mass or more and 10% by mass or less with respect to the total mass (solid content) of the thermosetting composition, the coefficient of linear expansion (CTE) is lowered and the adhesion is improved. become good.

When using a thermosetting component having a plurality of cyclic (thio)ether groups in the molecule as (A) the thermosetting component, it is preferable to contain a thermosetting catalyst (curing catalyst). Such thermosetting catalysts include, for example, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole. , 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4-(dimethylamino)-N,N-dimethylbenzylamine, 4-methoxy-N,N amine compounds such as -dimethylbenzylamine and 4-methyl-N,N-dimethylbenzylamine; hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. In addition, commercially available products include, for example, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, and 2P4MHZ manufactured by Shikoku Kasei Co., Ltd. (all are trade names of imidazole compounds), and U-CAT3503N and UCAT3502T manufactured by San-Apro. (all are trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof). In particular, it is not limited to these, and it may be a thermosetting catalyst for epoxy resins or oxetane compounds, or any one that promotes the reaction between an epoxy group or an oxetanyl group and a carboxyl group, either alone or in combination of two or more. may be used.

A normal quantitative ratio of these curing catalysts is sufficient. For example, 0.1 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the epoxy compound and/or oxetane compound is suitable. If the amount of the curing catalyst is within this range, the curability is good and the pot life is long.

[(B) Aluminum oxide particles]
The (B) aluminum oxide particles used in the present invention are desirably spherical. By using spherical aluminum oxide, it is possible to moderate the increase in viscosity when highly filled. The average particle size of such aluminum oxide particles is 0.01 μm to 50 μm, more preferably 0.01 μm to 20 μm. If the average particle size is less than 0.01 μm, the viscosity of the composition becomes too high, making it difficult to disperse and apply to the object to be coated. On the other hand, if the average particle size is larger than 50 μm, the particles will protrude into the coating film and the sedimentation rate will increase, resulting in poor storage stability. Further, by blending two or more average particle sizes having a particle size distribution for close packing, it is possible to achieve a higher packing, which is preferable from both aspects of storage stability and thermal conductivity.

Here, in the present specification, the average particle size of (B) aluminum oxide particles is an average particle size (d50) including not only the particle size of primary particles but also the particle size of secondary particles (aggregates), It is the value of d50 measured by the laser diffraction method. Microtrac MT3300EX11 manufactured by Nikkiso Co., Ltd. can be used as a measuring device using the laser diffraction method.

(B) Commercially available aluminum oxide particles include DAW-05 (manufactured by Denka, average particle size 5 μm), DAW-10 (manufactured by Denka, average particle size 10 μm), AS-40 (manufactured by Showa Denko, average particle size 12 μm), AS-50 (manufactured by Showa Denko, average particle size 9 μm), and the like.

(B) Aluminum oxide particles should be blended in the range of 40% by mass to 95% by mass, preferably in the range of 60% by mass to 95% by mass, based on the total mass (solid content) of the thermosetting composition. can be done.

(B) Aluminum oxide particles should be blended in the range of 40% by mass to 95% by mass, preferably in the range of 60% by mass to 95% by mass, based on the total mass (solid content) of the thermosetting composition. can be done.

(B) Aluminum oxide particles can effectively reduce the thermal conductivity of the cured coating obtained by making the total mass (solid content) of the thermosetting composition 40% by mass or more. It is possible to increase the strength of the cured film by setting it to mass% or less

[(C) acrylic block copolymer]
(C) The acrylic block copolymer is blended for the purpose of improving adhesion of the cured film of the thermosetting composition of the present invention to a high melting point substrate and improving heat resistance.

A block copolymer is a copolymer having a molecular structure in which two or more types of polymers having different properties are connected by covalent bonds to form a long chain. Those that are solid in the range of 20°C to 30°C are preferred. It may be solid within this range and may be solid at temperatures outside this range. Since it is a solid within the above temperature range, it exhibits excellent tackiness when applied to a substrate and temporarily dried.

The (C) acrylic block copolymer used in the present invention is an XYX or XYX' type terpolymer. Of the XYX or XYX' type block copolymer, the Y in the center is a soft block and has a low glass transition point Tg, preferably less than 0°C, and both outer sides X and X' is a hard block, has a high Tg, and is preferably composed of polymer units having a temperature of 0° C. or higher. The glass transition point Tg is measured by differential scanning calorimetry (DSC).

In the XYX or XYX' type (C) acrylic block copolymer, X and X' consist of polymer units having a Tg of 50°C or higher, and Y has a Tg of -20. C. or less is more preferred.

In addition, among the XYX or XYX' type (C) acrylic block copolymers, X and X' preferably have high compatibility with the above (A) thermosetting component, Y preferably has low compatibility with the thermosetting component (A). Thus, it is considered that a block copolymer in which both end blocks are compatible with the matrix and the center block is incompatible with the matrix makes it easier to exhibit a specific structure in the matrix.

X and X' are polymer blocks mainly composed of methacrylic acid ester units, and are polymer blocks mainly composed of methacrylic acid ester units. In addition, "mainly composed of methacrylic acid ester units" means that 50% by mass or more of structural units derived from methacrylic acid ester are contained based on the total mass of polymer blocks X and X'. The proportion of the structural unit derived from the methacrylic acid ester contained in X and X' is preferably 60% by mass or more, more preferably 80% by mass or more, and 100% by mass in the polymer blocks X and X'. may

Examples of methacrylate esters for forming polymer blocks X and X' include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, and methacrylic acid. Methacrylic acid alkyl esters such as isobornyl can be mentioned, among which methyl methacrylate is preferred. The polymer blocks X and X' may be composed of one type of these methacrylic acid esters, or may be composed of two or more types.

Y is a polymer block mainly composed of acrylate units, and is a polymer block mainly composed of acrylate units. The expression “mainly composed of acrylic acid ester units” means that based on the total mass of the polymer block Y, 50% by mass or more of structural units derived from acrylic acid esters are included. The ratio of the structural unit derived from the acrylic acid ester contained in Y is preferably 60% by mass or more, more preferably 80% by mass or more, and may be 100% by mass in the polymer block Y.

In addition, a hydrophilic structural unit having excellent compatibility with the thermosetting component (A), such as the aforementioned epoxy resin, may be introduced into the structural units of X and/or X'. Thereby, compatibility can be improved further. The hydrophilic structural unit as used herein includes, for example, a styrene unit, a hydroxyl group-containing structural unit, a carboxyl group-containing structural unit, an epoxy-containing structural unit, an N-substituted acrylamide structural unit, and the like.

Examples of acrylic acid esters for forming polymer block Y include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, phenoxyethyl acrylate, Examples include alkyl acrylates such as 2-methoxyethyl acrylate, more preferably n-butyl acrylate and 2-ethylhexyl acrylate, and particularly preferably n-butyl acrylate. The polymer block Y may be composed of one of these acrylic acid esters, or may be composed of two or more.

(C) when the acrylic block copolymer is of the XYX type, the mass percentage of X relative to the total mass of the (C) acrylic block copolymer is 12% by mass or more and 35% by mass or less; It is preferably 15% by mass or more and 30% by mass or less. Further, when the (C) acrylic block copolymer is of the XYX' type, the mass percentage of the sum of X and X' with respect to the total mass of the (C) acrylic block copolymer is 12% by mass. 35% by mass or more, preferably 15% by mass or more and 30% by mass or less.

When the thermosetting composition of the present invention is applied to a high-melting-point substrate and cured, the adhesiveness to the high-melting-point substrate is ensured when the mass percentage is 12% by mass or more and 35% by mass or less. In addition, it is possible to obtain a cured film having excellent heat resistance.

(C) Commercially available acrylic block copolymers include Clarity (registered trademark) LA2250, Clarity (registered trademark) LA2140, Clarity (registered trademark) LA2330, Clarity (registered trademark) LA3320, Clarity (registered trademark) KL- LK9333, Clarity (registered trademark) LK-9243 (manufactured by Kuraray Co., Ltd.) and the like.

(C) The method for producing the acrylic block copolymer is not particularly limited, and a method according to a known method can be employed. For example, a method of living polymerization of monomers constituting each block is generally used.

(C) The acrylic block copolymer has a weight average molecular weight in the range of 20,000 to 400,000, preferably in the range of 67,000 to 79,000. Within this range, it is possible to obtain a thermosetting composition which is excellent in tackiness after being applied to a substrate and temporarily dried, and which is excellent in printability and workability.

(C) The amount of the acrylic block copolymer to be blended is 0.5% by mass or more and 20% by mass or less, preferably 0.5% by mass or more and 10% by mass, based on the total mass (solid content) of the thermosetting composition. % or less, particularly preferably 0.5 mass % or more and 5 mass % or less.

(C) The amount of the acrylic block copolymer is 0.5% by mass or more and 20% by mass or less with respect to the total mass (solid content) of the thermosetting composition, so that the crosslink density of the thermosetting resin can be maintained at a high level.

[Other ingredients]
Furthermore, antioxidants, organic solvents, defoaming agents/leveling agents, dispersants, and colorants can be added to the thermosetting composition of the present invention.

The antioxidant suppresses oxidation of the conductor (copper) on the substrate, thereby improving the adhesion between the substrate and the cured film of the thermosetting composition. Antioxidants include hindered phenol compounds such as 3-(N-salicyloyl)amino-1,2,4-triazole, sulfur-based antioxidants such as zinc salt of 2-mercaptobenzimidazole, and triphenyl phosphite. , aromatic amine antioxidants such as di-tert-butyldiphenylamine, and complex dry compounds containing nitrogen as a heteroatom such as melamine, benzotriazole, and tolyltriazole. Among them, melamine and benzotriazole are preferred, and melamine is particularly preferred.

When an antioxidant is blended, the blending amount is 0.03% by mass or more and 5% by mass or less with respect to the total mass (solid content) of the thermosetting composition of the present invention, and 0.1% by mass It is preferable that it is more than 2 mass % or less.

Organic solvents can be used to adjust the thermosetting composition of the present invention or to adjust the viscosity for application to substrates. Any known organic solvent can be used as the organic solvent.

Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum solvents. More specifically, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl Ether, glycol ethers such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether Esters such as acetate, propylene glycol ethyl ether acetate, propylene glycol butyl ether acetate; alcohols such as ethanol, propanol, ethylene glycol, propylene glycol; aliphatic hydrocarbons such as octane and decane; petroleum ether, petroleum naphtha, hydrogenated petroleum These include petroleum solvents such as naphtha and solvent naphtha. Such organic solvents may be used singly or as a mixture of two or more.

Antifoaming agents and leveling agents can be added to prevent deterioration of surface smoothness and deterioration of interlayer insulation due to voids and pinholes. Antifoaming agents (leveling agents) include silicone antifoaming agents and non-silicone antifoaming agents that are foam breaking polymer solutions. Commercially available silicone antifoaming agents include BYK (registered trademark)- 063, BYK (registered trademark)-065, BYK (registered trademark)-066N, BYK (registered trademark)-067A, BYK (registered trademark)-077 (manufactured by BYK-Chemie Japan), KS-66 (Shin-Etsu Chemical Co., Ltd. made), etc.

In addition, commercial products of non-silicone antifoaming agents include BYK (registered trademark)-054, BYK (registered trademark)-055, BYK (registered trademark)-057, BYK (registered trademark)-1790, BYK (registered trademark) )-1791 (manufactured by BYK-Chemie Japan).

When an antifoaming agent (leveling agent) is blended, the amount thereof is 10% by mass or less, preferably 0.01% by mass, based on the total mass (solid content) of the thermosetting composition of the present invention. It is more than 3 mass % or less.

A dispersant can be blended in order to improve the dispersibility and sedimentation of the (B) aluminum oxide particles.

Commercially available dispersing agents include, for example, ANTI-TERRA-U, ANTI-TERRA-U100, ANTI-TERRA-204, ANTI-TERRA-205, DISPERBYK-101, DISPERBYK-102, DISPERBYK-103, DISPERBYK-106, DISPERBYK-108, DISPERBYK-109, DISPERBYK-110, DISPERBYK-111, DISPERBYK-112, DISPERBYK-116, DISPERBYK-130, DISPERBYK-140, DISPERBYK-142, DISPERBYK-145, DISPERBYK-161, DISPERBYK-162, DISPERBYK- DISPERBYK-163, DISPERBYK-164, DISPERBYK-166, DISPERBYK-167, DISPERBYK-168, DISPERBYK-170, DISPERBYK-171, DISPERBYK-174, DISPERBYK-180, DISPERBYK-182, DISPERBYK-183, DISPERBYK- 185, DISPERBYK-184, DISPERBYK-2000, DISPERBYK-2001, DISPERBYK-2009, DISPERBYK-2020, DISPERBYK-2025, DISPERBYK-2050, DISPERBYK-2070, DISPERBYK-2096, DISPERBYK-2150, BYK-P104, BYK- P104S, BYK-P105, BYK- 9076, BYK-9077, BYK-220S (manufactured by BYK-Chemie Japan), Disparlon 2150, Disparlon 1210, Disparlon KS-860, Disparlon KS-873N, Disparlon 7004, Disparlon 1830, Disparlon 1860, Disparlon 1850, Disparlon DA- 400N, Disparon PW-36, Disparon DA-703-50 (manufactured by Kusumoto Kasei Co., Ltd.), Floren G-450, Floren G-600, Floren G-820, Floren G-700, Floren DOPA-44, Floren DOPA- 17 (manufactured by Kyoeisha Chemical Co., Ltd.).

When a dispersant is blended, the blending amount is 0.1 parts by mass or more and 10 parts by mass or less, preferably 0.1 parts by mass or more and 5 parts by mass with respect to 100 parts by mass (solid content) of aluminum oxide particles (B). Part by mass or less.

As the coloring agent, conventionally known coloring agents such as red, blue, green and yellow can be used, and any of pigments, dyes and dyes can be used. Specifically, those with a Color Index (C.I.; published by The Society of Dyers and Colorists) number can be mentioned. However, from the viewpoint of reducing the environmental load and the effect on the human body, it is preferable to use a colorant that does not contain halogen.

Examples of red colorants include monoazo, disazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone colorants.

Blue colorants include phthalocyanine-based and anthraquinone-based coloring agents, and pigment-based compounds include compounds classified as pigments. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

As green colorants, there are similarly phthalocyanine-based, anthraquinone-based, and perylene-based coloring agents, and in addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used.

Examples of yellow colorants include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, and anthraquinone colorants.

In addition, coloring agents such as purple, orange, brown and black may be added for the purpose of adjusting the color tone.

Further, if necessary, known and commonly used additives such as known and commonly used polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol and phenothiazine, flame retardants and flame retardant aids are added. be able to.

<Coated substrate>
The coated substrate of the present invention has a cured coating of the thermosetting composition of the present invention.

The material of the high-melting-point substrate having a melting point of 270° C. or higher, to which the curable composition of the present invention is applied, is as described in the section on the thermosetting composition, and detailed description is omitted here. .

In the present invention, the high-melting-point base material may be an injection-molded article having a complicated shape, and a wiring pattern (electric circuit) may be formed on the surface thereof.

Examples of a method for forming a wiring pattern on such an injection-molded article include an LDS (Laser Direct Structuring) method. In the LDS method, first, a copper complex is kneaded into a thermoplastic resin and injection-molded, and laser drawing is performed on the surface of a molded body containing the copper complex. The copper complex is metallized by laser light irradiation, and the catalytic activity of electroless copper plating is expressed, so that the laser-drawn portion can be plated.

On this high melting point substrate, the thermosetting composition of the present invention is adjusted, for example, with the above-mentioned organic solvent to a viscosity suitable for the coating method, and is applied by dip coating method, flow coating method, roll coating method, bar coater method, screen. A tack-free coating film is formed by coating by a printing method, curtain coating method, or the like, and volatilizing and drying the organic solvent contained in the composition at a temperature of about 60 to 130°C (temporary drying).

The volatilization drying performed after applying the thermosetting composition of the present invention can be performed using a hot air circulation drying oven, IR oven, hot plate, convection oven, etc. are brought into contact with each other in a countercurrent flow and a method of spraying from a nozzle onto the support).

By heating this coating film to a temperature of, for example, about 140 to 180° C. for thermal curing, a coated substrate according to the present invention, in which a cured film is formed on a high-melting-point substrate, is obtained.

After that, the covered base material having the electric circuit exposes the land which becomes the soldering surface by laser opening, and after the land is subjected to surface treatment by gold plating, the component is mounted by soldering.

Soldering may be performed by hand soldering, flow soldering, reflow soldering, etc. For example, in the case of reflow soldering, preheating at 100° C. to 140° C. for 1 to 4 hours After that, the solder is heated and melted by repeating heating at a temperature of 240° C. or more and less than 270° C. for about 5 to 20 seconds a plurality of times (for example, 2 to 4 times) to perform a reflow process.

After the reflow process, it is cooled and the parts are mounted to complete the three-dimensional circuit molded part (MID).

The coated substrate of the present invention, that is, the coated substrate having a cured film of the thermosetting composition of the present invention on a high melting point substrate having a melting point of 270 ° C. or higher has heat resistance, rigidity, and adhesion to the substrate. It can be applied to various uses due to its excellent properties and insulating properties, and there are no particular restrictions on the application. For example, it is possible to manufacture coated substrates having etching resists, solder resists, and marking resists as cured films on injection-molded high-melting-point substrates. It is possible to suitably produce a coated substrate having a solder resist, which requires heat resistance, as a cured film.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited only to these Examples. In addition, "part" shall mean a mass part unless there is particular notice below.

<1. Preparation of thermosetting compositions of Examples 1 to 4 and Comparative Examples 1 to 4>
1. Preparation of Thermosetting Composition Each material was blended in proportions (unit: parts by mass) shown in Table 1, premixed with a stirrer, and then kneaded with a three-roll mill to prepare a thermosetting composition.

The following property tests were conducted on each of the above thermosetting compositions. Table 1 shows the results.

<2. Evaluation of Adhesion (Grid Adhesion) of Coating Film of Thermosetting Composition>
The thermosetting compositions of Examples 1 to 4 and Comparative Examples 1 to 4 were printed on an LCP substrate (TECACOMP LCP LDS 4107 manufactured by Ensinger) by screen printing so that the dry coating film became 30 μm, and printed at 150 ° C. for 60 minutes. was cured by heating. The deflection temperature under load (DTUL) based on ASTM D648 (1.82 MPa) of the above LCP substrate is 274°C.

In accordance with JIS K 5600-5-6, the cured coating film of the obtained cured product was cut to prepare 100 grids (10 × 10) each having a width of 1 mm in length and width, and a transparent adhesive tape ( Nichiban Co., Ltd., width: 18 mm) was completely adhered, and immediately one end of the tape was pulled off instantaneously while keeping it perpendicular to the glass substrate, and the state of the grid pattern was examined. Evaluation criteria are as follows.

Adhesion (cross-cut adhesion)
Class 0: The edges of the cut are completely smooth and no peeling occurs on any grid mesh.

Class 1: A small peeling of the paint film occurs at the intersection of the cuts. The crosscut part is affected by clearly no more than 5%.

Category 2: The coating is peeling along the edges of the cuts and/or at the intersections. The crosscut portion is clearly affected by more than 5%, but not more than 15%.

Class 3: The coating has severe partial or total delamination along the edges of the cuts and/or partial or total delamination in various parts of the eye. The cross-cut part is affected clearly more than 15%, but not more than 35%.

Class 4: The paint film is partially or totally peeled off along the edge of the cut, and/or some eyes are partially or totally peeled off. The cross-cut portion is clearly affected by more than 35% but never more than 65%.

Class 5: Large peeling of Class 4 or more is generated.

<3. Evaluation of solder heat resistance of coating film of thermosetting composition>
The thermosetting compositions of Examples 1 to 4 and Comparative Examples 1 to 4 were printed on an LCP substrate (TECACOMP LCP LDS 4107 manufactured by Ensinger) by screen printing so that the dry coating film became 30 μm, and printed at 150 ° C. for 60 minutes. was cured by heating.

A rosin-based flux was applied to the resulting cured coating film, allowed to flow in a solder bath at 260 ° C. for 30 seconds, washed with propylene glycol monomethyl ether acetate and dried, and then a transparent adhesive tape (manufactured by Nichiban Co., Ltd., width: 18 mm) to evaluate the presence or absence of peeling.

Solder heat resistance ◯: No peeling.
x: There is peeling.

*1: Cresol novolac type epoxy resin, epoxy equivalent 209-219 (g/eq) (N-695: manufactured by DIC)
*2: Spherical aluminum oxide with an average particle size of about 8 μm (DAW-07: manufactured by Denka)
*3: Spherical aluminum oxide with an average particle size of about 3 μm (DAW-03: manufactured by Denka)
*4: Spherical aluminum oxide with an average particle size of about 0.3 μm (ASFP-20: manufactured by Denka)
*5: Barium sulfate (B-30: manufactured by Sakai Chemical Industry Co., Ltd.)
*6: Talc (LMS-200: manufactured by Fuji Talc Industry Co., Ltd.)
*7: Polymer type acrylic block copolymer with a PMMA (polymethyl methacrylate) ratio of 15 wt% (Clarity (registered trademark) LA3320: manufactured by Kuraray Co., Ltd.)
*8: Middle molecular type, acrylic block copolymer with a PMMA ratio of 20 wt% (Clarity (registered trademark) LA2330: manufactured by Kuraray Co., Ltd.)
*9: Low-molecular type acrylic block copolymer with a PMMA ratio of 20 wt% (Clarity (registered trademark) LA2140: manufactured by Kuraray Co., Ltd.)
*10: Middle molecular type, acrylic block copolymer with a PMMA ratio of 30 wt% (Clarity (registered trademark) LA2250: manufactured by Kuraray Co., Ltd.)
*11: Low-molecular-weight acrylic block copolymer with a PMMA ratio of 10 wt% (Clarity (registered trademark) LA2114: manufactured by Kuraray Co., Ltd.)
*12: Low-molecular-weight acrylic block copolymer with a PMMA ratio of 40 wt% (Clarity (registered trademark) LA2270: manufactured by Kuraray Co., Ltd.)
*13: Dicyandiamide (DICY7: manufactured by Mitsubishi Chemical Corporation)
*14: 2-ethyl-4-methylimidazole (2E4MZ: manufactured by Shikoku Kasei Co., Ltd.)
*15: Micronized melamine (Melamine: manufactured by Nissan Chemical Industries, Ltd.)
*16: Dipropylene glycol monoethyl ether
*17: Silicone antifoaming agent (KS-66: manufactured by Shin-Etsu Chemical Co., Ltd.)
*18: Non-silicon antifoaming agent (BYK-1791: manufactured by BYK-Chemie Japan)
*19: Dispersant (BYK-111: manufactured by BYK-Chemie Japan)

As shown in Examples in Table 1, (B) aluminum oxide particles and (C) an acrylic block copolymer in which the mass percentage of the sum of X and X' is 12% by mass or more and 35% by mass or less are blended. The adhesion of the cured film of the thermosetting composition of the present invention to the high-melting-point substrate was good, and peeling did not occur. Similarly, when (B) aluminum oxide particles and (C) an acrylic block copolymer in which the mass percentage of the sum of X and X' is 12% by mass or more and 35% by mass or less are blended, the soldering heat resistance of the cured film was good, and cracks did not occur in the cured film.

On the other hand, as shown in Comparative Examples 1 and 2, when a block copolymer in which the mass percentage of the sum of X and X' is outside the range of 12% by mass or more and 35% by mass or less is blended, the thermosetting composition The adhesion of the cured film of No. 1 to the high-melting-point substrate was lowered, and peeling occurred.

Furthermore, as shown in Comparative Example 3, even if the (C) acrylic block copolymer having a mass percentage of the sum of X and X' of 12% by mass or more and 35% by mass or less is blended, it can be used as an inorganic filler. (B) When the aluminum oxide particles were not blended, it was not possible to obtain a cured film having satisfactory soldering heat resistance and adhesion.

Claims (6)

A thermosetting composition for application to a high-melting substrate having a melting point of 270° C. or higher,
(A) a thermosetting component;
(B) aluminum oxide particles;
(C) the following formula (I) or the following formula (II)
XYX (I) or XYX' (II)
(In the formula, X and X′ are polymer blocks mainly composed of methacrylate units having a glass transition point Tg of 0° C. or higher, and Y is mainly composed of acrylic ester units having a glass transition point Tg of less than 0° C. is a polymer block that
wherein the mass percentage of the sum of X and X' relative to the total mass of the acrylic block copolymer is in the range of 12% by mass or more and 35% by mass or less. a block copolymer;
including
(A) the amount of the thermosetting component is in the range of 1% by mass or more and 10% by mass or less with respect to the total mass (solid content) of the thermosetting composition;
(B) the amount of aluminum oxide particles is 40% by mass or more and 95% by mass or less with respect to the total mass (solid content) of the thermosetting composition;
(C) Thermosetting characterized in that the amount of the acrylic block copolymer is in the range of 0.5% by mass or more and 20% by mass or less with respect to the total mass (solid content) of the thermosetting composition Composition. 2. The thermosetting composition according to claim 1, wherein (C) the acrylic block copolymer has a weight average molecular weight of 65,000 or more and 80,000 or less. 3. The thermosetting composition according to claim 1, wherein (C) the acrylic block copolymer is an acrylic block copolymer represented by the formula (I). 4. The polymer block according to claim 3, wherein in the formula (I), X is a polymer block mainly composed of methyl methacrylate units, and Y is a polymer block mainly composed of n-butyl acrylate units. thermosetting composition. The thermosetting composition according to any one of claims 1 to 4, characterized in that said high melting point substrate is selected from the group consisting of liquid crystal polymer, polyphenylene sulfide and polyetheretherketone. A coated substrate comprising a cured coating of the thermosetting composition according to any one of claims 1-5 .