Photocurable components

Abstract

The present disclosure generally provides compositions having improved heat aging resistance, crack resistance, and flux compatibility, where the resin composition includes: (a) an epoxy resin including a compound having two or more epoxy groups per molecule; (b) a binder including a compound having at least one carboxyl group per molecule; (c) a photoinitiator; and (d) a filler composition including silica, talc, and wollastonite.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of international patent application having serial number PCT / CN2020 / 097364, filed June 22, 2020, the entire disclosure of which is incorporated herein by reference.

[0002] Field FIELD OF THE DISCLOSURE This disclosure relates generally to photocurable compositions, and more particularly to photocurable compositions used in solder masks. [Background technology]

[0003] The use of compositions comprising epoxy resins and fillers for solder mask applications is known in the art, however, such compositions available in the art have lower than desirable heat aging resistance, crack resistance, and flux convertibility.

[0004] For example, US Pat. No. 5,629,999 discloses epoxy resins that use either fused silica or wollastonite as a filler, but the examples that use fused silica exhibit poor crack resistance performance.

[0005] US Patent No. 5,949,999 discloses an epoxy resin that uses both fused silica and wollastonite as fillers, but the amount of filler used in the composition is much higher than the amount the inventors intended to use, which may result in poor solvent resistance.

[0006] Therefore, there is a need for photocurable compositions that have improved heat aging resistance, crack resistance, and flux compatibility over currently available photocurable compositions. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Patent No. 6,342,547 [Patent Document 2] U.S. Patent No. 8,999,433 Summary of the Invention

[0008] Surprisingly, it has been found that the compositions and processes of the present disclosure address the above-mentioned problems. Advantages of the photocurable compositions disclosed herein over current compositions include: (1) improved heat aging resistance; (2) improved crack resistance; and / or (3) improved flux compatibility.

[0009] The present disclosure relates to photocurable compositions having improved crack resistance over the prior art, and processes for preparing these compositions. In one aspect, the present disclosure provides a photocurable composition comprising: (a) an epoxy resin comprising a compound having two or more epoxy groups per molecule; (b) a binder comprising a compound having at least one carboxyl group per molecule; (c) a photoinitiator; and (d) a filler composition comprising silica, talc, and wollastonite.

[0010] In another aspect, the present disclosure provides a method for making an insulating layer by coating a substrate with a photocurable composition and then curing the photocurable composition.

[0011] In yet another aspect, the present disclosure provides an insulating layer comprising a substrate coated with a photocurable composition of the present disclosure. to provide. DETAILED DESCRIPTION OF THE INVENTION

[0012] When appearing herein, the term "comprising" and its derivatives are not intended to exclude the presence of any additional component, step, or procedure, whether or not they are disclosed herein. For the avoidance of any doubt, all compositions claimed herein may include any additional additives or compounds by use of the term "comprising," unless stated to the contrary. In contrast, the term "consisting essentially of," when appearing herein, excludes from the scope of any succeeding recitation any other component, step, or procedure, except those that are not essential to operability, and the term "consisting of," when used, excludes any component, step, or procedure not specifically described or listed. The term "or," unless otherwise stated, refers to the listed members individually and in any combination.

[0013] The articles "a" and "an" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, "a resin" means one resin or more than one resin.

[0014] The phrases "in one embodiment," "according to one embodiment," and the like generally mean that the particular feature, structure, or characteristic that follows the phrase is included in at least one embodiment of the invention, and may be included in more than one embodiment of the invention. Importantly, such phrases do not necessarily refer to the same embodiment.

[0015] If the specification states that a component or feature "may," "can," "could," or "might" be included or have a property, that particular component or feature need not be included or have the property.

[0016] The present disclosure generally provides photocurable compositions that include: (a) an epoxy resin including a compound having two or more epoxy groups per molecule; (b) a binder including a compound having at least one carboxyl group per molecule; (c) a photoinitiator; and (d) a filler composition including silica, talc, and wollastonite.

[0017] Suitable epoxy resins as component (a) are those conventional in the epoxy resin art. Non-limiting examples of epoxy resins are: I) Polyglycidyl or poly(β-methylglycidyl) ethers obtainable by reacting a compound having at least two free alcoholic hydroxy groups and / or phenolic hydroxy groups with epichlorohydrin or β-methylepichlorohydrin under alkaline conditions or in the presence of an acid catalyst, followed by alkali treatment.

[0018] Glycidyl ethers of this type are derived, for example, from acyclic alcohols, such as ethylene glycol, diethylene glycol or higher poly(oxyethylene) glycols, propane-1,2-dials or poly(oxypropylene) glycols, propane-1,3-diol, butane-1,4-diol, poly(oxytetramethylene) glycols, pentane-1,5-diol, hexane-1,6-diol, hexane-2,4,6-triol, glycerol, 1,1,1-trimethylol-propane, pentaerythritol, sorbitol, and also from polyepichlorohydrins.

[0019] Further glycidyl ethers of this type can be obtained from cycloaliphatic alcohols, such as 1,4-cyclohexanedimethanol, bis(4-hydroxycyclohexyl)methane or 2,2-bis(4-hydroxycyclohexyl)propane, or from alcohols containing aromatic groups and / or further functional groups, such as N,N-bis(2-hydroxyethyl)aniline or is derived from p,p'-bis(2-hydroxyethylamino)diphenylmethane. The glycidyl ethers may also be based on mononuclear phenols such as resorcinol or hydroquinone, or polynuclear phenols such as bis(4-hydroxyphenyl)methane, 4,4'-dihydroxybiphenyl, bis(4-hydroxyphenyl)sulfone, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane, or 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane.

[0020] Further hydroxy compounds suitable for the preparation of glycidyl ethers are novolaks which can be obtained by condensation of aldehydes, such as formaldehyde, acetaldehyde, chloral or furfuraldehyde, with unsubstituted or substituted chlorine atoms or C1-C9 alkyl groups, or with bisphenols, such as phenol, 4-chlorophenol, 2-methylphenol or 4-tert-butylphenol.

[0021] II) Biphenyl epoxy resins (e.g., YX4000 manufactured by Mitsubishi Chemical Corporation), biphenyl novolac epoxy resins (e.g., NC-3000 manufactured by Nippon Kayaku Co., Ltd.), biphenyl ether epoxy resins (e.g., YSLV-80XY manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), special difunctional epoxy resins (e.g., YSLV-120TE manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), dicyclopentadiene epoxy resins (e.g., EPICLON HP-7200H manufactured by DIC Corporation), naphthalene epoxy resins (e.g., EPICLON HP-4032, EPICLON HP-4700, EPICLON HP-4770 manufactured by DIC Corporation).

[0022] III) Polyglycidyl or poly(β-methylglycidyl) ethers obtainable by reacting a compound having at least two free alcoholic hydroxy groups and / or phenolic hydroxy groups with epichlorohydrin or β-methylepichlorohydrin under alkaline conditions or in the presence of an acid catalyst, followed by alkali treatment.

[0023] Glycidyl ethers of this type are derived, for example, from acyclic alcohols, such as ethylene glycol, diethylene glycol or higher poly(oxyethylene) glycols, propane-1,2-dials or poly(oxypropylene) glycols, propane-1,3-diol, butane-1,4-diol, poly(oxytetramethylene) glycols, pentane-1,5-diol, hexane-1,6-diol, hexane-2,4,6-triol, glycerol, 1,1,1-trimethylol-propane, pentaerythritol, sorbitol, and also from polyepichlorohydrins.

[0024] Further glycidyl ethers of this type are derived from alicyclic alcohols such as 1,4-cyclohexanedimethanol, bis(4-hydroxycyclohexyl)methane or 2,2-bis(4-hydroxycyclohexyl)propane, or from alcohols containing aromatic groups and / or further functional groups, such as N,N-bis(2-hydroxyethyl)aniline or p,p'-bis(2-hydroxyethylamino)diphenylmethane. Glycidyl ethers can also be based on mononuclear phenols such as resorcinol or hydroquinone, or polynuclear phenols such as bis(4-hydroxyphenyl)methane, 4,4'-dihydroxybiphenyl, bis(4-hydroxyphenyl)sulfone, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane or 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane.

[0025] Further hydroxy compounds suitable for the preparation of glycidyl ethers are novolaks which can be obtained by condensation of aldehydes, such as formaldehyde, acetaldehyde, chloral or furfuraldehyde, with unsubstituted or substituted phenols or bisphenols, such as phenol, 4-chlorophenol, 2-methylphenol or 4-tert-butylphenol, which are substituted with chlorine atoms or C1-C9 alkyl groups.

[0026] IV) Poly(N-glycidyl) compounds obtainable by dehydrochlorination of reaction products of epichlorohydrin with amines containing at least two amine hydrogen atoms, such as aniline, n-butylamine, bis(4-aminophenyl)methane, m-xylylenediamine or bis(4-methylaminophenyl)methane.

[0027] However, poly(N-glycidyl) compounds also include triglycidyl isocyanurate, N,N'-diglycidyl derivatives of cycloalkylene ureas, such as ethene urea or 1,3-propylene urea, and diglycidyl derivatives of hydantoins, such as 5,5-dimethylhydantoin.

[0028] V) Cycloaliphatic epoxy resins, such as bis(2,3-epoxycyclopentyl) ether, 2,3-epoxycyclopentyl glycidyl ether, 1,2-bis(2,3-epoxycyclopentyloxy)ethane or 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate.

[0029] However, it is also possible to use epoxy resins in which the 1,2-epoxy groups are bonded to different heteroatoms or functional groups; such compounds include, for example, the N,N,O-triglycidyl derivative of 4-aminophenol, the glycidyl ether glycidyl ester of salicylic acid, N-glycidyl-N'-(2-glycidyloxypropyl)-5,5-dimethylhydantoin and 2-glycidyloxy-1,3-bis(5,5-dimethyl-1-glycidylhydantoin-3-yl)propane.

[0030] The term "cycloaliphatic epoxy resin" in the context of the present disclosure refers to any epoxy resin having cycloaliphatic structural units, i.e., includes both cycloaliphatic glycidyl compounds and β-methylglycidyl compounds, as well as epoxy resins based on cycloalkylene oxides.

[0031] Suitable cycloaliphatic glycidyl and β-methylglycidyl compounds are the glycidyl and β-methylglycidyl esters of cycloaliphatic polycarboxylic acids, such as tetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid and 4-methylhexahydrophthalic acid.

[0032] Further suitable cycloaliphatic epoxy resins are the diglycidyl ethers and β-methylglycidyl ethers of cycloaliphatic alcohols, such as 1,2-dihydroxycyclohexane, 1,3-dihydroxycyclohexane and 1,4-dihydroxycyclohexane, 1,4-cyclohexanedimethanol, 1,1-bis(hydroxymethyl)cyclohex-3-ene, bis(4-hydroxycyclohexyl)methane, 2,2-bis(4-hydroxycyclohexyl)propane and bis(4-hydroxycyclohexyl)sulfone.

[0033] Examples of epoxy resins having a cycloalkylene oxide structure include bis(2,3-epoxycyclopentyl) ether, 2,3-epoxycyclopentyl glycidyl ether, 1,2-bis(2,3-epoxycyclopentyl)ethane, vinylcyclohexene dioxide, 3,4-epoxycyclohexylmethyl 3',4'-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3',4'-epoxy- 6'-methylcyclohexanecarboxylate, bis(3,4-epoxycyclohexylmethyl)adipate and bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate.

[0034] Preferred cycloaliphatic epoxy resins are bis(4-hydroxycyclohexyl)methane diglycidyl ether, 2,2-bis(4-hydroxycyclohexyl)propane diglycidyl ether, tetrahydrophthalic acid diglycidyl ester, 4-methyltetrahydrophthalic acid diglycidyl ester, 4-methylhexahydrophthalic acid diglycidyl ester, 3,4-epoxycyclohexylmethyl 3′,4′-epoxycyclohexanecarboxylate, and especially hexahydrophthalic acid diglycidyl ester.

[0035] Aliphatic epoxy resins can also be used as the epoxy resin of component (a). Aliphatic epoxy resins include, but are not limited to, epoxidation products of unsaturated fatty acid esters. When epoxidation products of unsaturated fatty acid esters are used as the epoxy resin of component (a), it is preferred to use epoxy-containing compounds derived from mono- and poly-fatty acids having 12 to 22 carbon atoms and 30 to 400 iodine numbers, such as lauroleic acid, myristoleic acid, palmitoleic acid, oleic acid, gadoleic acid, erucic acid, ricinoleic acid, linoleic acid, linolenic acid, elaidic acid, licanic acid, arachidonic acid, and clupanodonic acid.

[0036] Non-limiting examples of suitable epoxidation products of unsaturated fatty acid esters for component (a) are the epoxidation products of soybean oil, linseed oil, perilla oil, tung oil, oiticica oil, safflower oil, poppy oil, hemp oil, cottonseed oil, sunflower oil, rapeseed oil, polyunsaturated triglycerides, triglycerides derived from Euphorbia plants, peanut oil, olive oil, olive kernel oil, almond oil, kapok oil, hazelnut oil, apricot kernel oil, beech oil, lupine oil, corn oil, sesame oil, grape seed oil, Lallemantia oil, castor oil, herring oil, sardine oil, menhaden oil, whale oil, tall oil and derivatives thereof.

[0037] The more highly unsaturated derivatives obtainable by subsequent dehydrogenation of these oils are also suitable as epoxy resins.

[0038] The olefinic double bonds of the unsaturated fatty acid groups of the above-mentioned compounds can be epoxidized according to known methods, for example by reaction with hydrogen peroxide, alkyl hydroperoxides or peracids such as performic acid or peracetic acid, optionally in the presence of a catalyst. Within the scope of the present disclosure, both fully epoxidized oils and partially epoxidized derivatives that still contain free double bonds can be used for component (a).

[0039] Preference is given to the use of epoxidized soybean oil and epoxidized linseed oil.

[0040] Mixtures of the above-mentioned epoxy resins I) to V) can also be used. The photocurable composition according to the present disclosure preferably comprises, as component (a), an aromatic or alicyclic glycidyl ether or glycidyl ester that is liquid or solid at 25°C, preferably a diglycidyl ether or diglycidyl ester of bisphenol A or bisphenol F. Preferred epoxy resins can also be obtained by reacting polyglycidyl ethers and polyglycidyl esters with alcohols such as diols. The reaction with diols increases the molecular weight.

[0041] Particularly preferred are epoxy resins that are glycidyl ethers of bisphenol A reacted with less than an equimolar amount of bisphenol A.

[0042] According to a preferred embodiment, the photocurable composition comprises a polyglycidyl ester, poly(β-methyl The epoxy resin may be selected from the group consisting of poly(β-methylglycidyl) esters, polyglycidyl ethers, poly(β-methylglycidyl) ethers, and mixtures thereof.

[0043] According to one embodiment, 40 to 80% by weight of the epoxy resin comprises a biphenyl-type epoxy resin having an epoxy equivalent of 150 to 450 g / mol.

[0044] According to another embodiment, 20 to 40% by weight of the epoxy resin comprises a bisphenol A type epoxy resin having an epoxy equivalent weight of 175 to 210 g / mol.

[0045] According to one embodiment, the epoxy resin is present in the photocurable composition in an amount ranging from about 5% to about 30% by weight, or preferably from about 5% to about 15% by weight, based on the total weight of the photocurable composition.

[0046] In one embodiment, the binder comprising a compound having at least one carboxyl group per molecule (i.e., component (b)) comprises a mixture of (i) one or more of a cresol novolac resin or an aromatic epoxy resin, and (ii) one or more of a carboxyl-functional polyester resin, a carboxyl-functional acrylic resin, or a glycidyl-functional acrylic resin.

[0047] Carboxyl-functional acrylic resins and glycidyl-functional acrylic resins include alkyl (meth)acrylates, non-limiting examples of which include methyl acrylate, methyl methacrylate, ethyl acrylate, acrylic acid, methacrylic acid, butyl acrylate, and butyl methacrylate.

[0048] The weight average molecular weight (Mw) of the binder is in the range of 1,000 to 80,000 daltons, preferably 2,000 to 40,000 daltons.

[0049] Molecular weight (MW) is the weight average molecular weight determined by the gel permeation chromatography (GPC) method using polystyrene as the standard.

[0050] In another embodiment, component (b) (i.e., a binder containing a compound having at least one carboxyl group per molecule) is obtained by reacting a cresol novolac epoxy compound and an unsaturated monocarboxylic acid with a saturated or unsaturated polybasic acid anhydride, and then reacting any unreacted saturated or unsaturated polybasic acid anhydride with a hydroxyl group-containing monomer to remove the saturated or unsaturated polybasic acid anhydride.

[0051] In yet another embodiment, component (b) is obtained by reacting bisphenol A epoxy acrylate with a diisocyanate. The diisocyanate can be any of the commonly available diisocyanates, such as hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), methylene diisocyanate (MDI), methylene biscyclohexyl isocyanate, trimethylhexamethyl diisocyanate, hexane diisocyanate, hexamethylamine diisocyanate, methylene biscyclohexyl isocyanate, toluene diisocyanate, 1,2-diphenylethane diisocyanate, 1,3-diphenylpropane diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethyl diisocyanate, and the like. Preferably, for maximum flexibility of the oligomer, the diisocyanate is an aliphatic diisocyanate, such as HDI. At this point, the molecule has diisocyanate functionality.

[0052] According to one embodiment, the binder containing a compound having at least one carboxyl group per molecule is preferably about 10% by weight to about 60% by weight, based on the total weight of the photocurable composition. Alternatively, it is present in the photocurable composition in an amount ranging from about 30% to about 50% by weight.

[0053] In one embodiment, the binder containing a compound having at least one carboxyl group per molecule has an acid value of 40 mg KOH / g or greater. Preferably, the acid value of the binder containing a compound having at least one carboxyl group per molecule is 60 mg KOH / g or greater. Additionally, the acid value of the binder containing a compound having at least one carboxyl group per molecule is preferably 120 mg KOH / g or less, or more preferably 100 mg KOH / g or less.

[0054] In another embodiment, the photopolymerization initiator of the present disclosure is a free radical photoinitiator. Typical representatives of free radical photoinitiators are benzoins such as benzoin, benzoin ethers such as benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether, benzoin phenyl ether and benzoin acetate, acetophenone, acetophenone such as 2,2-dimethoxy-acetophenone and 1,1-dichloroacetophenone, benzil ketals such as benzil dimethyl ketal and benzil diethyl ketal, anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone and 2-amylanthraquinone, and also triphenylphosphine, benzyl ketal, ... dibenzoylphosphine oxides, for example 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (Luzirin® TPO), bisacylphosphine oxides, benzophenones such as benzophenone and 4,4′-bis(N,N′-dimethylamino)benzophenone, thioxanthones and xanthones, acridine derivatives, phenazine derivatives, quinoxaline derivatives or 1-phenyl-1,2-propanedione 2-O-benzoyloxime, 1-aminophenyl ketones or 1-hydroxyphenyl ketones, for example 1-hydroxycyclohexyl phenyl ketone, phenyl 1-hydroxyisopropyl ketone and 4-isopropylphenyl 1-hydroxyisopropyl ketone.

[0055] Preferably, the free radical photoinitiator is 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-isopropylthioxanthone, or a mixture thereof.

[0056] According to one embodiment, the photoinitiator is present in the photocurable composition in an amount ranging from about 1 wt % to about 10 wt %, preferably from about 2 wt % to about 6 wt %, based on the total weight of the photocurable composition.

[0057] An essential component of the photocurable composition according to the present disclosure is a filler composition comprising silica, talc, and wollastonite. The filler composition may optionally further comprise at least one of barium sulfate and kaolin.

[0058] Silica is an oxide of silicon with the chemical formula SiO2.

[0059] According to a preferred embodiment, the silica is amorphous silica. Preferably, the amorphous silica is natural amorphous silica or fused silica.

[0060] According to a preferred embodiment, the amorphous silica has an average particle size (d ) determined according to ISO 13320-1:1999 of 1 to 100 μm, more preferably 2 to 50 μm, and most preferably 2 to 10 μm. 50 )

[0061] D 50 is known as the median particle size. This means that the powder 50 Particle size larger than the value 50% of the particles have a size of d 50 50% of the particles have a particle size smaller than the value D. 95 is the particle size at which 95% of the particles are d 95 The particle size is smaller than the value, and 5% of the particles are d 95 It means that the size is larger than the value.

[0062] Preferably, the amorphous silica is surface-treated, more preferably with a silane selected from the group consisting of aminosilanes, epoxysilanes, (meth)acrylic silanes, methylsilanes, and vinylsilanes.

[0063] Preferably, the silane is a (meth)acrylic silane.

[0064] Talc has the chemical formula Mg3Si4O 10Talc is a clay mineral composed of hydrated magnesium silicate with the formula (OH). Powdered talc is widely used as a filler. For example, talc is sold by Fuji TALC INDUSTRIAL Co., Ltd. under the name FH105.

[0065] Preferably, the talc is surface treated. Preferably, the talc is surface treated with a silane, more preferably a silane selected from the group consisting of aminosilanes, epoxysilanes, (meth)acrylic silanes, methylsilanes and vinylsilanes.

[0066] Preferably, the silane is a (meth)acrylic silane.

[0067] The third essential filler component is wollastonite. Wollastonite is a naturally occurring, acicular calcium silicate of the formula Ca3[SiO9] with a particle size in the micron range. Artificially produced wollastonite is also acicular. Wollastonite is sold, for example, by Nyco Company under the name Nyad® or by Quarzwerke (Germany) under the name TREMIN®, e.g., TREMIN® 283-100EST or TREMIN® 283-600EST.

[0068] According to a preferred embodiment, the wollastonite has an average particle size d determined according to ISO 13320-1:1999, preferably between 1 and 100 μm, more preferably between 3 and 50 μm, and most preferably between 2 and 15 μm. 50 It is a powder having the formula:

[0069] Further preferred is that the wollastonite has a particle size d determined according to ISO 13320-1:1999 of 1 to 200 μm, more preferably 2 to 100 μm, and most preferably 3 to 20 μm. 95 The photocurable composition has the following structure:

[0070] The wollastonite is preferably 0.40 to 0.90 g / cm 3 , more preferably 0.49 to 0.80 g / cm 3, and most preferably 0.55 to 0.76 g / cm 3 The bulk density, determined in accordance with DIN 52466, is

[0071] Particularly preferred are 2 to 5 m determined according to DIN 66132 2 / g specific surface BET.

[0072] Photocurable compositions according to the present disclosure preferably include surface-treated wollastonite. Preferably, the wollastonite is surface-treated with a silane, preferably a silane selected from the group consisting of aminosilanes, epoxysilanes, (meth)acrylic silanes, methylsilanes, and vinylsilanes.

[0073] Preferably, the silane is a (meth)acrylic silane.

[0074] According to one embodiment, the filler composition is present in the photocurable composition in an amount ranging from about 20% to about 50% by weight, preferably from about 30% to about 39% by weight, based on the total weight of the photocurable composition.

[0075] In another embodiment, the photocurable composition may further optionally include acrylate monomers, curing agents, coupling agents, defoamers, flame retardants, antioxidants, solvents, surfactants, pigments, polymerization inhibitors, stabilizers, or any of the other typical additives used in epoxy resin materials.

[0076] Advantages of the photocurable compositions disclosed herein over the prior art include (1) improved heat aging resistance; (2) improved crack resistance; and / or (3) improved flux compatibility.

[0077] The present disclosure also provides a method for forming an insulating layer, comprising coating a substrate with a photocurable composition disclosed herein; pre-drying the coated substrate at about 70°C to 80°C for about 30 to 90 minutes; irradiating the coated substrate with activation energy; first heat-curing the coated substrate at about 20°C to 40°C for about 30 to 120 seconds; dissolving and removing the unexposed areas of the coated substrate; and then heat-curing the coated substrate at about 100°C to 200°C for about 30 to 120 minutes.

[0078] Additionally, the present disclosure also provides an insulating layer produced by the methods described herein.

[0079] The following examples should be considered illustrative of the present disclosure and not limiting in any way.

[0080] raw material Solvent 1: ethyl diglycol acetate (supplier: Polynt, UK); Solvent 2: DOWANOL® PMA propylene glycol monomethyl ether acetate (Supplier: The Dow Chemical Company, USA); Binder 1: PR-3000 carboxyl group-containing modified cresol novolac epoxy acrylate (supplier: Showa Denka highpolymer Cop. Shanghai); Binder 2: KAYARAD® UXE-3000 acid-modified epoxy acrylate (Supplier: Nippon Kayaku, Japan); Binder 3: CYCLOMER® PACAZ-250 acid-modified acrylate copolymer (Supplier: Daicel Corporation, Japan); Photoinitiator 1: IRGACURE® 369 2-benzyl-2-(dimethylamino)-1-[4-(morpholinyl)phenyl)]-1-butanone (supplier: IGM); Photoinitiator 2: IHT-PI TPO diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide (supplier: Insight High Technology); Photoinitiator 3: IHT-PI ITX 2-isopropylthioxanthone (Supplier: Insight High Technology); Photoinitiator 4: IRGACURE® OXE02 ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) (supplier: BASF, Germany); Photoinitiator 5: JMT-784 bis(eta5-2,4-cyclopentadien-1-yl)bis[2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl]titanium (Supplier: Yueyang Kimoutain Sci-tech); Acrylate Monomer 1: SR444NS Pentaerythritol Triacrylate (Supplier: Sartomer); Acrylate Monomer 2: KAYARAD® DPCA-60 Ethoxylated Dipentaerythritol Hexaacrylate (Supplier: Nippon Kayaku, Japan); Acrylate Monomer 3: ETERMER® 2308 tris(2-hydroxyethyl)isocyanurate triacrylate (Supplier: Eternal); hardener 1:1-cyanoguanidine (supplier: Alzchem Trostberg, Germany); Hardener 2: DYHARD® UR300 Fenuron (Supplier: Alzchem Trostberg, Germany); Curing agent 3: 2,4,6-triamino-1,3,5-triazine (supplier: Sichuan Yunong Chemical); Epoxy 1: NC-3000 biphenyl novolac epoxy resin (supplier: Nippon Kayaku, Japan); Epoxy 2: jER YX-4000k 2,2'-((3,3',5,5'-tetramethyl-(1,1'-biphenyl)-4,4'-diyl)-bis(oxymethylene))-bis-oxirane (Supplier: Mitsubishi Chemical Corporation, Japan) Epoxy 3: ARALDITE® GY 2600 bisphenol A epoxy resin (supplier: Huntsman Advanced Materials, Switzerland); Pigment 1: Pigment Yellow 147 (Supplier: BASF, Germany); Pigment 2: Pigment Blue 15:4 (Supplier: ChemFine International); Coupling agent: SLIQUEST® A-174 γ-methacryloxypropyltrimethoxysilane (supplier: Momentive); Antioxidant: IRGANOX® 1010 pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (Supplier: BASF, Germany); Polymerization inhibitor: dihydroxy-1,4 benzene (supplier: Rhodia); Antifoaming agent: KSZ-66 silicone oil (supplier: Shinetsu Silicone); Filler 1: MEGASIL™ 525 fused silica (supplier: Sibelco); Filler 2: TIKRON® 1363-800EST talc surface-treated with epoxy silane (supplier: Quarzwerke Group); Filler 3: TIKRON® 1363-800MST talc surface treated with acrylate silane (supplier: Quarzwerke Group); Filler 4: TREMIN® 283-600EST wollastonite surface treated with epoxy silane (Supplier: Quarzwerke Group); Filler 5: TREMIN® 283-600MST wollastonite surface treated with acrylate silane (Supplier: Quarzwerke Group); Filler 6: Barium sulfate B34 (supplier: Sakai Chemical); Filler 7: POLARITE® 102A Kaolin (Supplier: Imerys)

[0081] Examples 1 to 15: The ingredients for Examples 1-15 are shown in Table 1. All values ​​listed in Table 1 refer to parts by weight of the photocurable composition. As shown in Table 1, Examples 8-15 were comparative examples that included filler compositions not according to the present disclosure.

[0082] [Table 1-1]

[0083] [Table 1-2]

[0084] procedure Examples 1 to 15 were prepared by combining the components, mixing at room temperature until the mixture was homogeneous, and milling on a triple roll mill. A glass fiber epoxy copper-clad laminate plate containing a 50 μm-thick copper foil was prepared. A designed pattern was formed by etching on the epoxy copper-clad laminate plate to obtain a core material. The surface of the obtained core material was completely covered with a photocurable composition by a screen printing method, which was then dried by heating at 75°C for 40 minutes to obtain a coating with a thickness of 25 μm. A negative mask was placed directly on the coating, and ultraviolet light was irradiated onto the negative mask using an exposure device equipped with a metal halide lamp, thereby forming the coating at 400 mJ / cm. 2The coating was selectively exposed to light at an exposure of 100 Hz. The negative mask was then removed from the coating, and the coating was developed using a 1.0% aqueous sodium carbonate solution at a temperature of approximately 28-32°C for 90 seconds, leaving a portion of the coating that had hardened upon exposure as a solder mask layer on the printed circuit board. The solder mask layer was then further heated at 150°C for 60 minutes to thermally cure it. As a result, a test specimen containing a solder mask layer was obtained.

[0085] result physical properties

[0086] [Table 2-1]

[0087] [Table 2-2]

[0088] 1) Tested according to IPC-TM-650 2.4.27.2, pencil hardness; target ≥ 5H 2) Tested according to IPC-TM-650 2.3.42; target: no blistering or discoloration 3) Tested according to IPC-TM-650 2.4.6; target: no delamination 4) Tested according to ISO 2409; target GT0 or GT1 5) The evaluation boards were placed in a cold-hot chamber with a working temperature cycle of -40°C to 160°C for crack resistance testing. Each cycle lasted 30 minutes with a 10-second break between cycles. The appearance of the boards was observed with a 100x magnifier after 1000 and 2000 cycles. The crack rate was calculated for the crack angle out of the total angle of the board. The crack resistance test was also called thermal cycle test (TCT), which was performed according to methods known in the art (see, for example, patent application US2012125672). P = Passed the exam

[0089] Table 2 shows the physical properties of Examples 1-15. For Examples 1-7, the compositions have improved heat aging resistance, crack resistance, and flux compatibility. However, when the amount of filler composition is too high (Example 7), it affects solvent resistance. The composition using the acrylate silane-treated filler has better crack resistance than the composition using the epoxy silane-treated filler (Example 5). The compositions using only one filler (Examples 8-12) or two fillers (Examples 13-15) have insufficient solvent resistance or crack resistance, which cannot meet the requirements for solder mask applications.

Claims

1. (a) an epoxy resin containing a compound having two or more epoxy groups per molecule; (b) a binder comprising a compound having at least one carboxyl group per molecule; (c) a photopolymerization initiator; and (d) a filler composition comprising silica, talc, and wollastonite Including, the filler composition is present in the photocurable composition in an amount ranging from 20% to 50% by weight, based on the total weight of the photocurable composition; Photocurable composition.

2. 2. The photocurable composition according to claim 1, wherein the epoxy resin comprises a biphenyl-type epoxy resin having an epoxy equivalent of 150 to 450 g / mol.

3. 3. The photocurable composition according to claim 2, wherein 40 to 80% by weight of the epoxy resin comprises a biphenyl-type epoxy resin having an epoxy equivalent of 150 to 450 g / mol.

4. The photocurable composition according to any one of claims 1 to 3, wherein the epoxy resin comprises a bisphenol A type epoxy resin having an epoxy equivalent weight of 175 to 210 g / mol.

5. 5. The photocurable composition according to claim 1, wherein 20 to 40% by weight of the epoxy resin comprises a bisphenol A type epoxy resin having an epoxy equivalent weight of 175 to 210 g / mol.

6. 6. The photocurable composition of claim 1, wherein the epoxy resin is present in the photocurable composition in an amount ranging from 5% to 30% by weight, based on the total weight of the photocurable composition.

7. A photocurable composition as described in claim 6, wherein the epoxy resin is present in the photocurable composition in an amount ranging from 5% by weight to 15% by weight, based on the total weight of the photocurable composition.

8. 8. The photocurable composition according to any one of claims 1 to 7, wherein the binder comprising a compound having at least one carboxyl group per molecule is present in the photocurable composition in an amount ranging from 10% to 60% by weight, based on the total weight of the photocurable composition.

9. A photocurable composition as described in claim 8, wherein the binder containing a compound having at least one carboxyl group per molecule is present in the photocurable composition in an amount ranging from 30% by weight to 50% by weight, based on the total weight of the photocurable composition.

10. 10. The photocurable composition of claim 1, wherein the photoinitiator is present in the photocurable composition in an amount ranging from 1 wt % to 10 wt %, based on the total weight of the photocurable composition.

11. The photocurable composition described in claim 10, wherein the photopolymerization initiator is present in the photocurable composition in an amount ranging from 3% by weight to 5% by weight, based on the total weight of the photocurable composition.

12. The photocurable composition according to any one of claims 1 to 11, wherein the silica is amorphous silica.

13. 13. The photocurable composition of any one of claims 1 to 12, wherein the filler composition is present in the photocurable composition in an amount ranging from 30% to 38% by weight, based on the total weight of the photocurable composition.

14. 14. A method for forming an insulating layer, comprising: coating a substrate with the photocurable composition of any one of claims 1 to 13; pre-drying the coated substrate at 70°C to 80°C for 30 to 90 minutes; irradiating the coated substrate with active energy; first heat-curing the coated substrate at 20°C to 40°C for 30 to 120 seconds; dissolving and removing the unexposed areas of the coated substrate; and then heat-curing the coated substrate at 100°C to 200°C for 30 to 120 minutes.

Images