A curable potting composition that does not contain high-suspension substances

Abstract

The present invention relates to a curable potting composition based on acetoacetate and its use in electronic devices. In particular, the present invention relates to a curable potting composition based on a multifunctional acetoacetate and a multifunctional (meth)acrylate.

Description

Technical Field

[0001] The present invention relates to a curable potting composition based on acetoacetate and its use in electronic devices. In particular, the present invention relates to a curable potting composition based on polyfunctional acetoacetate and polyfunctional (meth)acrylate.

Background Art

[0002] Potting materials are a permanent protection solution for electronic devices. Materials used for high-temperature applications are required to have thermal stability, a high glass transition temperature, and a low coefficient of thermal expansion. The current method is to cure an epoxy resin with an anhydride or an amine curing agent. However, such curing agents generally contain substances of very high concern (SVHC) and carcinogenic, mutagenic, and reprotoxic (CMR) compounds.

[0003] For example, US6,462,108B1 discloses an epoxy-based potting composition that exhibits a high glass transition temperature (Tg), a low coefficient of thermal expansion (CTE), and a low curing shrinkage rate. However, the anhydride curing agent used is subject to SVHC. More specifically, the methylhexahydrophthalic anhydride (MHHPA) used in the examples is classified as a substance causing systemic health hazards in REACH.

[0004] Therefore, efforts have been made to find a safer method that does not contain harmful compounds to replace the current methodology.

[0005] WO2016 / 054367A1 discloses a multi-pack solventless curable composition used for hollow fiber filtration potting applications. It aims to give the cured potting material resistance to chemicals such as cleaning and sterilization reagents. However, since the potting material exhibits a lower glass transition temperature, this composition may not be suitable for potting electronic devices.

[0006] WO2016 / 054380 discloses a multipack, solvent-free, room-temperature curing, isocyanate-free preparation for use as an adhesive in helical filtration applications. Hardness (Shore A), gelation time, chemical resistance, and bubble formation were evaluated. However, the glass transition temperature of the material is not reported.

[0007] WO2014 / 052644 discloses a carbon-Michael compound for use in high-temperature applications to reduce heat transfer between materials. For this purpose, the carbon-Michael compound is positioned between a heat-supplying side and a heat-receiving side. The heat source can have temperatures ranging from 100°C to 290°C. The material may be in foam form, and for this reason, surfactant additives are introduced in the preparations. Furthermore, a harmful DBU is used as a catalyst. The degradation onset temperature by thermogravimetric analysis (TGA) and the storage modulus by dynamic mechanical analysis (DMA) are provided. However, the glass transition temperature of the material is not reported.

[0008] WO2015 / 047584A1 discloses a thermosetting elastomer bonding composition for cable bonding, comprising a polyfunctional Michael donor and acceptor. The described Michael acceptor groups are based on a polyether polyol capped with a polyisocyanate compound that further reacts with a hydroxyethyl acrylate. The resulting PU-based acrylate reacts in AATMP in the presence of DBU as a catalyst. This patent uses toxic substances such as toxic isocyanates and DBU. Curing occurs at room temperature for a relatively long time (about 2 days) without the addition of additional heat. Gelation time, water absorption, glass transition temperature (-53 to 90°C), and weight loss (3.5 to 7.1%) are reported.

[0009] Furthermore, it has been reported that strongly basic inorganic salts, which can impair the final stability of the material due to hydrolysis of ester bonds, are used as catalysts. For example, US4,408,018B discloses the use of strongly basic salts (NaOH, KOH, EtOH, and TBAOH) in the presence of a solvent to catalyze Michael addition. EP1283235B1 reports the use of solvent-based Michael addition compositions for laminate adhesives. Sodium ethoxide in ethanol is used as a catalyst, and peel strength is measured. EP1435383A1 discloses the use of Michael addition compositions in laminates, foams, and elastomers. Peel strength and Tg (maximum Tg at 33°C) are measured. US7,514,528B2 discloses the use of an aqueous solution of KOAc as a catalyst in Michael addition, and peel strength and pot life are measured. US8,013,368B2 teaches the use of sodium ethoxide in ethanol-catalyzed Michael addition for laminates. A peel test was performed.

[0010] EP1323760B1 describes phosphine as a suitable catalyst for crosslinking reactions between compounds containing α,β-unsaturated carbonyl groups and CH-acidic methylene groups. Trialkylphosphines were used, and trioctylphosphine (TOP) in particular showed significantly better stability compared to the commonly used, toxic DBU. Acetoacetate and malonate were cured with acrylate. Pot life, solvent resistance, pencil hardness, and yellowing were evaluated. The Tg values ​​of the materials were not reported.

[0011] US2009 / 0283213 discloses a two-component bonding system that can be crosslinked by a Michael reaction. A mixed resin is synthesized from ethyl malonate and a polyol (neopentyl glycol) to produce a polyester polyol (OH-terminated malonate-polyester). The resulting polyester is reacted with MDI, and then with hydroxyacrylate to obtain acrylate terminal chains. DBN dissolved in ethyl acetate is used as a catalyst. In this case, the same molecule contains both the Michael donor and the Michael acceptor. The catalyst-containing component is added to other components to obtain an elastic film. This patent uses harmful isocyanates and volatile organic compounds as solvents. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] U.S. Patent No. 6462108 [Patent Document 2] International Publication No. 2016 / 054367 [Patent Document 3] International Publication No. 2016 / 054380 [Patent Document 4] International Publication No. 2014 / 052644 [Patent Document 5] International Publication No. 2015 / 047584 [Patent Document 6] U.S. Patent No. 4408018 [Patent Document 7] European Patent No. 1283235 [Patent Document 8] European Patent Application Publication No. 1435383 [Patent Document 9] U.S. Patent No. 7514528 [Patent Document 10] U.S. Patent No. 8013368 [Patent Document 11] European Patent No. 1323760 [Patent Document 12] U.S. Patent Application Publication No. 2009 / 0283213

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0013] Therefore, an object of the present invention is to provide a safer alternative based on Michael addition to systems currently used in electronic potting.

MEANS FOR SOLVING THE PROBLEMS

[0014] This object is solved by a curable potting composition containing a polyfunctional (meth)acrylate compound in the presence of a polyfunctional acetoacetate compound, a catalyst and a filler, and the potting product has good thermal properties, a high glass transition temperature, low warpage and a low coefficient of thermal expansion.

MODE FOR CARRYING OUT THE INVENTION

[0015] In one aspect, the present invention relates to a polyfunctional acetoacetate compound, (meth)acrylate compound having at least 3 (meth)acrylate groups, a catalyst, and a filler, wherein the equivalent ratio of the (meth)acrylate compound having at least 3 (meth)acrylate groups to the polyfunctional acetoacetate compound is more than 1.5. (meth)acrylate compound having at least 3 (meth)acrylate groups is more than 1.5 with respect to the polyfunctional acetoacetate compound.

[0016] In another aspect, the present invention relates to a first member comprising a polyfunctional acetoacetate compound, and a second member comprising a (meth)acrylate compound having at least 3 (meth)acrylate groups, wherein at least one of the first member and the second member further contains a catalyst, and At least one of the first member and the second member further includes a filler, The equivalent ratio of the (meth)acrylate compound having at least three (meth)acrylate groups to the polyfunctional acetoacetate compound is greater than 1.5.

[0017] In yet another aspect, the present invention relates to the use of a curable potting composition or a two-component curable potting composition in an electronic device.

[0018] Further preferred embodiments of the present invention are described in the claims.

[0019] In this specification, the terms “a (one),” “an (one),” and “at least one” are equivalent to the term “one or more” and are interchangeable.

[0020] As used herein, “one or more” refers to at least one of the species mentioned and includes 1, 2, 3, 4, 5, 6, 7, 8, 9 or more. Similarly, “at least one” means one or more, i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9 or more. As used herein with respect to any component, “at least one” refers to numerical values ​​of chemically distinct molecules, i.e., numerical values ​​of different types of the reference species, but not to the numerical values ​​of all molecules.

[0021] As used herein, "substantially free" means that the substance is not intentionally added in the formulation of the curable potting composition, is present in only small amounts in the curable potting composition, and does not impair the performance of the potting composition. In preferred embodiments, the curable potting composition does not contain such components. However, since such substances may inevitably be present in intentionally added components, for example as impurities, in other embodiments, the curable potting composition contains such substances in an amount of 1% by weight or less, preferably 0.1% by weight or less of the composition.

[0022] Where the molecular weight of a polymer or its components is referred to herein, this refers to the number-average molecular weight (Mn) unless otherwise explicitly stated. The number-average molecular weight (Mn) can be calculated based on end-group analysis (OH value according to DIN 53240) or determined by gel permeation chromatography according to DIN 55672-1:2007-08 using THF as the eluent. Unless otherwise specified, all given molecular weights are determined by end-group analysis. The weight-average molecular weight (Mw) can be determined by GPC, as described for Mn.

[0023] All percentages given herein with respect to compositions or preparations are weight percent of the total weight of each composition or formulation, unless otherwise explicitly stated.

[0024] According to the present invention, a curable potting composition that does not contain SVHCs comprises a polyfunctional acetacetate compound, a (meth)acrylate compound having at least three (meth)acrylate groups, a catalyst, and a filler.

[0025] The composition comprises two or more components as described herein. The components of each component are stored in a separate container (component) from the other components until the contents of all containers are mixed together to form a mixture of adhesive compositions before application. When applied and cured, a solid material is formed in the potting area.

[0026] Electronic devices are exposed to relatively high operating temperatures and undergo repeated temperature cycles from seasonal ambient temperatures to high operating temperatures (above 100°C). Key material parameters that ensure the performance and reliability of these devices include a low coefficient of thermal expansion (CTE) at operating temperature, or lower than that of the potted component, low curing shrinkage, and low warpage. Therefore, materials with high thermal stability and a high Tg (above working temperature) are required.

[0027] The curable potting composition is prepared to provide a cured product having a Tg of 130°C or higher, preferably 130°C to 200°C, and more preferably 130°C to 160°C, as measured by DMA.

[0028] The curable potting composition is prepared to yield a cured product exhibiting a CTE of 0 to 100, preferably 15 to 70 μm / m·°C, at 150°C, as measured by thermomechanical analysis.

[0029] The curable potting composition is prepared to provide a cured product exhibiting a weight loss of 0–1.5% at 180°C in an air atmosphere, as measured by TGA.

[0030] The curable potting composition is prepared to provide a cured product exhibiting a warp of 0 to 150 μm, preferably 0 to 50 μm.

[0031] Furthermore, curable potting compositions offer other advantages. For example, the adhesive compositions are solvent-free, have usable viscosity and pot life, and cure quickly. Finally, curable potting compositions provide a strong adhesive bond that is resistant to moisture and chemicals.

[0032] In the curable potting composition of the present invention, the relative ratio of the polyfunctional (meth)acrylate compound as a Michael acceptor to the polyfunctional acetate compound as a Michael donor can be characterized by the reaction equivalent ratio, which is the ratio of the total number of functional groups in the curable composition to the number of Michael active hydrogen atoms in the polyfunctional acetate compound. The polyfunctional (meth)acrylate and the polyfunctional acetate compound are blended together immediately before application such that the equivalent ratio of functional (meth)acrylate groups to the active hydrogen in the polyfunctional acetate compound is greater than 1.5, preferably 1.6 to 2.0, and more preferably 1.7 to 1.9. Here, the equivalent ratio is defined as the ratio of the number of (meth)acrylate groups in the polyfunctional (meth)acrylate compound to the number of acetacetoxy groups in the polyfunctional acetate compound.

[0033] According to the present invention, a polyfunctional acetate compound may have at least two acetacetoxy groups, preferably 2 to 10 acetacetoxy groups, and more preferably 2 to 4 acetacetate groups. Therefore, the component may consist of a single compound having at least two acetacetoxy groups, or a mixture of two or more compounds, each having at least two acetacetoxy groups. Each of the compounds should preferably be characterized by a number-average molecular weight (Mn) of less than 12,000 g / mol, for example, less than 10,000 g / mol.

[0034] In a preferred embodiment, the curable potting composition comprises at least one acetoacetylated polyol, which can be obtained according to the following formula (reaction 1): JPEG2023519690000001.jpg19129(1) In the formula: R is C1-C 12 It is an alkyl group; L shows the main chain structure of the polyol; and q ≥ 2.

[0035] The above reaction 1 can be described as a transesterification reaction of a polyol by an acetacetate compound defined by the following formula (I), or more specifically, an acetyl exchange reaction. JPEG2023519690000002.jpg2655 formula (I) In the formula, R is the same as C1-C 12 It is an alkyl group. More typically, the constituent alkyl group R has 1 to 8 carbon atoms, preferably 1 to 6. Exemplary alkyl acetates include: t-butyl acetate; isobutyl acetate; n-butyl acetate; isopropyl acetate; n-propyl acetate; ethyl acetoacetate; and methyl acetoacetate. t-butyl acetate is preferred here.

[0036] The polyol from reaction 1 above is represented by the following formula (II): L-(OH) q Formula (II) In the formula, q ≥ 2, and L represents the main chain structure. Such polyol(II) may optionally contain heteroatoms in their main chain or pendant side chains. Furthermore, polyol(II) may be monomeric polyhydric alcohols or have an oligomeric or polymeric main chain. Regardless, polyol(II) preferably has a number-average molecular weight (Mn) of less than 12,000 g / mol and 2 to 10, preferably 2 to 4, hydroxyl functional groups q.

[0037] In one embodiment, the curable potting composition comprises an acetoacetylated polyol obtained from a monomeric polyhydric alcohol. Examples of suitable monomeric polyhydric alcohols include, but are not limited to, the following: 1,2-butanediol; 1,3-butanediol; 1,4-butanediol; 2,3-butanediol; 2,4-pentanediol; butylethylpropanediol; 1,4-hexanediol; 1,4-cyclohexanedimethanol; pentaerythritol; dipentaerythritol; trimethyloleethane; trimethylolpropane; ditrimethylolpropane; tricyclodecanedimethanol; hydroquinone bis(2-hydroxyethyl) ether; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, pentamethylene glycol, hexamethylene glycol, hexylene glycol, neopentyl Alkylene glycols such as glycols; glycerol; castor oil; castor wax; sugars such as glucose, sucrose, fructose, raffinose, maltodextrose, galactose, xylose, maltose, lactose, mannose, and erythrose; sugar alcohols such as erythritol, xylitol, malitol, mannitol, and sorbitol; and hydroxyalkylated aliphatic diamines such as o,o'-bis(diethanolaminemethyl)-p-nonylphenol, N,N,N,N'-tetra(2-hydroxypropyl)ethylenediamine (Quadrol L available from BASF), and N,N,N,N-tetra(2-hydroxyethyl)ethylenediamine. In preferred embodiments, the polyfunctional acetoacetate compound is an acetoacetylated polyol obtained from glycerol, trimethylolpropane, ethanol isosorbide, neopentyl glycol, pentaerythritol, dimethylolpropane, dipentaerythritol, propoxylated monosaccharides, trimethylolethane, and combinations thereof.

[0038] Furthermore, the present invention does not prevent such polyfunctional acetoacetate compounds from including acetoacetylated polyols obtained from polyhydric alcohols of oligomers or polymers. In particular, the polyol(II) may be selected from the group consisting of polyoxyalkylene polyols, also called polyether polyols; polyester polyols including polycaprolactone polyols; polyesteramide polyols; polycarbonate polyols; polybutadiene polyols; polyurethane polyols; polyacrylate polyols; and combinations thereof. Preferably, such oligomer or polymer polyols should have the following characteristics: a number-average molecular weight (Mn) of up to 10,000 g / mol, preferably 250 to 6,000 g / mol. It is also noteworthy that one or more polyether polyols or polyester polyols may be used as starting materials. A commercially available example of a polyether polyol is Voranol CP260 (available from DowDuPont).

[0039] As is known in the art, polyester polyols can be prepared from the condensation reaction of a polybasic carboxylic acid or anhydride with a stoichiometrically excess polyhydric alcohol, or from a mixture of a polybasic carboxylic acid, a monobasic carboxylic acid, and a polyhydric alcohol. Suitable polybasic carboxylic acids and anhydrides for use in preparing polyester polyols include those having 2 to 18 carbon atoms, particularly those having 2 to 10 carbon atoms. Non-limiting examples of such polybasic carboxylic acids and anhydrides include adipic acid; glutaric acid; succinic acid; malonic acid; pimelic acid; sebacic acid; suberic acid; azelaic acid; 1,4-cyclohexanedicarboxylic acid; phthalic acid; phthalic anhydride; isophthalic acid; terephthalic acid; tetrahydrophthalic acid; hexahydrophthalic acid; and combinations thereof. The monobasic carboxylic acids that can be used include those having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, and examples include: formic acid; acetic acid; propionic acid; butyric acid; valeric acid; caproic acid; caprylic acid; capric acid; lauric acid; myristic acid; palmitic acid; stearic acid; and combinations thereof. Preferred polyhydric alcohols have 2 to 18 carbon atoms, preferably 2 to 10 carbon atoms. Exemplary polyhydric alcohols include, but are not limited to, ethylene glycol; propylene glycol; hexene-1,6-diol; trimethylolpropane; glycerol; neopentyl glycol; pentaerythritol; butylene glycol; 2-methyl-1,3-propanediol; hexylene glycol; and combinations thereof.

[0040] Polyether polyols can be produced by processes known in the art, for example, by the reaction of an alkene oxide with a polyvalent starter molecule in the presence of a suitable catalyst such as an alkali metal hydroxide, alkali metal alkoxide, or antimony pentachloride. Examples of alkene oxides include tetrahydrofuran; ethylene oxide; 1,2-propylene oxide; 1,2- and 2,3-butylene oxide; and styrene oxide. Examples of preferred starter molecules include, but are not limited to, water; ethylene glycol; 1,2- and 1,3-propanediol; 1,4-butanediol; diethylene glycol; and trimethylol-propane. Preferred polyether polyols for use herein are: poly(propylene oxide) polyol; poly(ethylene oxide) polyol; PTMEG; and mixtures thereof.

[0041] The polycarbonate polyols used herein may be selected from, but are not limited to, polycarbonate diols. Such polycarbonate diols can be produced by the reaction of a diol with a dialkyl or diaryl carbonate or phosgene. The reactant diol may be selected from, but is not limited to, 1,2-propanediol; 1,3-propanediol; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol; diethylene glycol; trioxyethylene glycol; and mixtures thereof. An example diaryl carbonate is diphenyl carbonate.

[0042] The transesterification (transacetylation) reaction 1 can be carried out by conventional methods known in the field of polymer chemistry. In this regard, see, in particular: Witzman et al., "Comparative Methods for the Preparation of Acetoacetylated Coating Resins," Journal of Coatings Technology, Vol. 62, No. 789, October 1990; and Witzman et al., "Transacetoacetylation with tert-butyl acetoacetate: Synthetic Applications," J. Org. Chemistry 1991, 56, 1713-1718. Typically, the reaction between an oligomer or polymer polyol and acetoacetate is carried out by mixing the polyol and acetoacetate in a suitable container, with or without a solvent, for example, at a temperature increase of 50°C to 200°C or 80°C to 150°C; preferably in the absence of a solvent. The reaction is completed by distilling off the resulting alcohol (R-OH) under reduced pressure. Furthermore, the reaction can be carried out in the presence of a catalytic amount of transesterification catalyst, and preferred examples include, but are not limited to, calcium acetate, zinc acetate, bismuth acetate, lead oxide, and trichloroacetic acid.

[0043] The reaction should proceed to the point where at least 99% of the hydroxyl groups are converted to acetoacetoxy functional groups: the degree of this conversion can be monitored and confirmed by 1H-NMR and TLC. The reactant can be used in an amount such that there is one OH group for each acetoacetoxy group, but it is also preferable to use a molar excess of acetoacetate to ensure a complete reaction.

[0044] The product of the transacetylation reaction described above can be used directly in the potting composition of the present invention, but the reaction product can also be first isolated and purified using methods known in the art. In this regard, extraction, evaporation, distillation, and chromatography would be suitable techniques.

[0045] According to the present invention, the polyfunctional (meth)acrylate compound has at least three (meth)acrylate groups, preferably at least four (meth)acrylate groups, and preferably four to six (meth)acrylate groups. Surprisingly, such a highly functional (meth)acrylate compound can achieve a high crosslinking density in the cured product, and as a result, it has been found to exhibit excellent glass transition temperature, CTE, warping, etc., making it suitable for use as a potting material.

[0046] Examples of polyfunctional (meth)acrylate compounds include, but are not limited to, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, or combinations thereof. One or more embodiments of the present invention provide that the polyfunctional acrylate compound is selected from the group consisting of trimethylolpropane triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, ethoxylated trimethylolpropane triacrylate, and combinations thereof.

[0047] The potting composition of the present invention uses a catalyst to perform a Michael addition reaction between a polyfunctional acetacetate compound and a (meth)acrylate compound having at least three (meth)acrylate groups at a temperature of room temperature to 200°C, preferably 100-180°C, to form a potting material with high crosslink density.

[0048] Examples of preferred catalysts in the present invention include, in particular, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), triazabicyclodecene (TBD), tetramethylguanidine (TMG), trioctylphophine (TOP), triphenylphophine (TPP), (tetrabutylammonium hydroxide) TBAOH, NaOH, KOH, NaOEt, KOEt, phosphazanes, and combinations thereof.

[0049] The molar ratio of the catalyst to the polyfunctional acetacetate compound is 0.01 to 5, preferably 0.05 to 1.

[0050] To achieve various determinative properties of the potting material, such as thermal expansion coefficient, shrinkage rate, warping, and electrical insulation, it is necessary to include a filler in the curable potting composition of the present invention. The filler should typically be included in an amount of 50 to 90% by weight, preferably 65 to 80% by weight, of the curable potting composition. Suitable fillers as specified herein include, for example, abrasive mineral substances such as chalk, lime powder, precipitated and / or exothermic silicic acid, zeolite, bentonite, magnesium carbonate, diatomaceous earth, alumina, clay, talc, titanium dioxide, iron oxide, zinc oxide, sand, quartz, flint, mica, and glass powder. Organic fillers can also be used, particularly shredded fibers such as carbon black, graphite, wood fibers, wood flour, sawdust, cellulose, cotton, pulp, cotton, wood chips, shredded straw, rice husks, and walnut shells. It is also possible to add short fibers such as glass fibers, glass filaments, polyacrylonitrile, carbon fibers, Kevlar fibers, and polyethylene fibers. Aluminum powder is also suitable as a filler. In one preferred embodiment, the filler is selected from silica, fused silica, fumed silica, alumina, aluminum nitride, calcium carbonate, and combinations thereof.

[0051] Preferably, the curable potting composition of the present invention is essentially free of substances of very high concern under the EU REACH regulation and carcinogenic, mutagenic, or reproductively toxic compounds under the EU CLP regulation, preferably in amounts of less than 0.1% by weight of the composition, and more preferably not present at all. Examples include substances commonly used in potting materials, such as DBU and isocyanates.

[0052] In another aspect, the present invention relates to a two-component curable potting composition, which is, A first member comprising a polyfunctional acetacetate compound, and A second member comprising a (meth)acrylate compound having at least three (meth)acrylate groups, Including, here, At least one of the first and second members further includes a catalyst. At least one of the first member and the second member further includes a filler, and The equivalent ratio of the (meth)acrylate compound having at least three (meth)acrylate groups to the polyfunctional acetoacetate compound is greater than 1.5.

[0053] The compositions of the present invention may, of course, also contain standard additives for potting compositions, such as pigments, plasticizers, leveling agents, foam inhibitors, rheology control agents, antioxidants, tackifiers, adhesion promoters, epoxy resins, and UV stabilizers. The selection and amount of appropriate additives are limited only in that they must be compatible with the other components of the composition and must not be detrimental to the use of the composition in potting applications. In the case of two-component compositions, the additives may be placed in either component or in both components. On the other hand, the curable potting compositions of the present invention are essentially, and preferably, free from, additives not commonly used in potting materials, such as surfactants and foaming agents.

[0054] The curable potting composition according to the present invention is preferably used in the manufacture of bare dies and electronic devices such as metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors (IGBTs), diodes, and light-emitting diodes (LEDs).

[0055] This disclosure may be further understood by reference to the following embodiments. These embodiments are intended to represent specific embodiments of this disclosure and are not intended to limit the scope of this disclosure. [Examples]

[0056] Examples material 1,6-Hexanediol diacrylate was obtained from Aldrich. 1,5-Diazabicyclo[4.3.0]nona-5-ene (DBN) was obtained from Aldrich. I obtained trioctylphosphine (TOP) from Alfa Aesar. The fused silica was obtained from Denka under the trade name Denka FB-35. The silane coupling agent was obtained from Alfa Aesar under the trade name Silane A147. The epoxy resin was obtained from Nantong Synasia under the product name Synasia S-720.

[0057] Test method conversion The conversion is 810cm -1 The acrylate band located at [location] was tracked by FTIR via disappearance. Infrared spectra were recorded with a PerkinElmer UATR Two-FT IR spectrometer. Spectra were recorded on neat or thin film.

[0058] Differential scanning calorimetry (DSC) was performed using TA Instruments' DSC Q1000. For analysis, the sample was subjected to two heating cycles from 30°C to 250°C under a nitrogen atmosphere at a heating / cooling rate of 10°C / min, with one cooling cycle in between. The reported glass transition data was obtained from the second heating cycle of the DSC.

[0059] Determination of Tg by DMA analysis The Tg of the material was measured using a DMA Q800 instrument from TA Instruments. 30x10x3mm test specimens were prepared using a suitable mold and heated from 0°C to 250°C at a ramp temperature of 2°C / min at a frequency of 1Hz and a strain level of 0.1%. Tg was calculated from the damping coefficient (tanθ) with respect to temperature.

[0060] Determination of CTE by TMA analysis Thermomechanical analysis (TMA) using a TA instrument was used to measure the coefficient of thermal expansion (CTE). TMA measured the dimensional change (μm) of the pressurized sample as a function of temperature. A probe of a specific shape was brought into contact with a sample film measuring 20x10x3mm, and the analysis was performed at specific heating rates from 0°C to 250°C. The reported CTE values ​​are expressed as μm / (m·oC).

[0061] Weight loss decisions using TGA analysis Weight loss was determined by thermogravimetric analysis using a TGA Q500 instrument from TA Instruments. Samples were heated from 30°C to 400°C using a heating rate of 10°C / min in an air atmosphere. Weight loss is reported at 180°C.

[0062] Curvature detection A glass fiber reinforced Teflon PSA tape, approximately 2 mm thick, was bonded to a 50 x 50 x 0.5 mm alumina substrate and cured in the mold. After curing, the Teflon frame was removed. Warping was determined by placing a zero mark in the center of the alumina substrate and two marks on each side. Using an Olympus BX51 optical microscope equipped with transmitted and reflected light and a micrometer screw, the amount of warping was calculated by the difference between the focal length aligned to the center (zero mark) and the distance aligned to the marks on each side.

[0063] Synthesis of acetacetate monomers The synthesis of trimethylolpropane triacetate (AATMP) and pentaerythritol tetraacetate (Penta-aa) was carried out according to the literature procedure WO2019 / 120923A1, with some modifications. Trimethylolpropane or pentaerythritol (1 eq.) and TBAA (1.1 eq.) were placed in a 500 mL three-necked round-bottom flask. Next, Y-adapters, mechanical stirring bars, and reflux condensers were fitted to each neck of the flask. Thermocouples and nitrogen connectors were adjusted to the Y-adapters. The temperature was set to 140°C under a nitrogen atmosphere (reflux reached approximately 92°C in 4 hours). Then, distillation was carried out at atmospheric pressure for 8 hours while slowly raising the temperature to 140°C. Finally, after the distillation stopped, vacuum distillation was carried out at 140°C from 900 mbar to 400 mbar for 2 hours. The reaction scheme is shown below. JPEG2023519690000003.jpg90170

[0064] Comparative Example AATMP (1 g) was pre-mixed with a suitable catalyst and stirred using a speed mixer at 3500 rpm for 1-3 minutes. Then, 1,6-hexanediol diacrylate was added to the mixture until the equivalent ratios were reached. The preparation was poured into a suitable mold and cured at room temperature for 4 hours. Table 1 shows the test results for Tg value and conversion rate.

[0065] [Table 1]

[0066] Comparative Example 3 3.0 g of pentaerythritol tetraacetate and 0.039 g of DBN were mixed in a speed mixer at 3500 rpm for 3 minutes as component A. 3.356 g of pentaerythritol tetraacrylate was used as component B. The two components were mixed in a speed mixer at 3500 rpm for 1 minute. The preparations were then poured into molds suitable for subsequent testing and cured at 150°C for 1 hour. The equivalence ratio of acrylate to acetate was 1.5.

[0067] Example 1 14.0 g of pentaerythritol tetraacetate and 0.18 g of DBN were mixed in a speed mixer at 3500 rpm for 3 minutes as component A. 17.75 g of pentaerythritol tetraacrylate was used as component B. The two components were mixed in a speed mixer at 3500 rpm for 1 minute. Next, the preparations were poured into a mold suitable for subsequent testing and cured at 150°C for 1 hour. The equivalent ratio of acrylate to acetate was 1.7.

[0068] Example 2 3.0 g of trimethylolpropanetriacetate, 0.029 g of DBN, and 10.27 g of fused silica were mixed in a speed mixer at 3500 rpm for 3 minutes as component A. 3.818 g of dipentaerythritol hexaacrylate and 10.27 g of fused silica, to be used as component B, were mixed in a speed mixer at 3500 rpm for 3 minutes. The two components were then mixed in a speed mixer at 3500 rpm for 1 minute. The preparations were then poured into molds suitable for subsequent testing and cured at 150°C for 1 hour. The equivalence ratio of acrylate to acetate was 1.7.

[0069] Example 3 Component A consisted of 2.7 g of pentaerythritol tetraacetate, 0.035 g of DBN, and 9.225 g of fused silica, which were mixed in a speed mixer at 3500 rpm for 3 minutes. Component B consisted of 3.423 g of pentaerythritol tetraacrylate and 9.225 g of fused silica, which were mixed in a speed mixer at 3500 rpm for 3 minutes. The two components were then mixed in a speed mixer at 3500 rpm for 1 minute. The preparations were then poured into molds suitable for subsequent testing and cured at 150°C for 1 hour.

[0070] Example 4 3.0 g of trimethylolpropanetriacetate, 0.029 g of DBN, and 10.27 g of fused silica were mixed in a speed mixer at 3500 rpm for 3 minutes as component A. 3.818 g of dipentaerythritol hexaacrylate and 10.27 g of fused silica, to be used as component B, were mixed in a speed mixer at 3500 rpm for 3 minutes. The two components were then mixed in a speed mixer at 3500 rpm for 1 minute. The preparations were then poured into molds suitable for subsequent testing and cured at 150°C for 1 hour.

[0071] Example 5 Component A consisted of 2.0 g of trimethylolpropanetriacetate, 0.019 g of DBN, and 7.112 g of fused silica, which were mixed in a speed mixer at 3500 rpm for 3 minutes. Component B consisted of 2.558 g of pentaerythritol tetraacrylate, 0.164 g of epoxy resin, 0.038 g of silane coupling agent, and 7.112 g of fused silica, which were mixed in a speed mixer at 3500 rpm for 3 minutes. The two components were then mixed in a speed mixer at 3500 rpm for 1 minute. The preparations were then poured into molds suitable for subsequent testing and cured at 150°C for 1 hour.

[0072] Example 6 Component A consisted of 2.0 g of trimethylolpropanetriacetate, 0.019 g of DBN, and 7.475 g of fused silica, which were mixed in a speed mixer at 3500 rpm for 3 minutes. Component B consisted of 2.8 g of dipentaerythritol hexaacrylate, 0.164 g of epoxy resin, 0.04 g of silane coupling agent, and 7.475 g of fused silica, which were mixed in a speed mixer at 3500 rpm for 3 minutes. The two components were then mixed in a speed mixer at 3500 rpm for 1 minute. The preparations were then poured into molds suitable for subsequent testing and cured at 150°C for 1 hour.

[0073] Tables 2 and 3 show the test results of the examples of the present invention. It is clear that the examples of the present invention showed excellent Tg, CTE, weight loss, and warpage, while the comparative examples having a bifunctional methacrylate as a curing agent failed to achieve higher Tg and other properties.

[0074] [Table 2]

[0075] [Table 3]

Claims

1. polyfunctional acetoacetate compounds, a (meth)acrylate compound having at least three (meth)acrylate groups; catalysts, and and a filler, wherein A curable potting composition, wherein the equivalent ratio of a (meth)acrylate compound having at least three (meth)acrylate groups to a polyfunctional acetoacetate compound is greater than 1.

5.

2. 10. The curable potting composition of claim 1, wherein the polyfunctional acetoacetate compound has at least two acetoacetate groups, preferably 2 to 10 acetoacetoxy groups, and more preferably 3 to 4 acetoacetoxy groups.

3. 3. The curable potting composition according to claim 1, wherein the equivalent ratio of the (meth)acrylate compound having at least three (meth)acrylate groups to the polyfunctional acetoacetate compound is 1.6 to 2.0, preferably 1.7 to 1.

9.

4. The curable potting composition according to any one of claims 1 to 3, wherein the polyfunctional acetoacetate compound is an acetoacetylated polyol obtained from glycerol, trimethylolpropane, ethanol isosorbide, neopentyl glycol, pentaerythritol, dimethylolpropane, dipentaerythritol, propoxylated monosaccharides, trimethylolethane, or a combination thereof.

5. The curable potting composition according to any one of claims 1 to 4, wherein the (meth)acrylate compound has at least four (meth)acrylate groups, preferably 4 to 6 (meth)acrylate groups.

6. 6. The curable potting composition according to claim 1, wherein the (meth)acrylate compound is selected from trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, and combinations thereof.

7. 7. The curable potting composition of claim 1, wherein the curing agent is selected from 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), triazabicyclodecene (TBD), tetramethylguanidine (TMG), trioctylphosphine (TOP), triphenylphosphine (TPP), (tetrabutylammonium hydroxide) TBAOH, NaOH, KOH, NaOEt, KOEt, phosphazanes, and combinations thereof.

8. The curable potting composition according to any one of claims 1 to 7, wherein the glass transition temperature of the cured product of the potting composition is 130°C or higher, 130°C to 200°C, preferably 130°C to 160°C.

9. The curable potting composition according to any one of claims 1 to 8, wherein the molar ratio of the catalyst to the polyfunctional acetoacetate compound is 0.01 to 5, preferably 0.05 to 1.

10. A curable potting composition according to any preceding claim, wherein the filler is present in an amount of 50 to 90% by weight of the curable potting composition, preferably 65 to 80% by weight.

11. A curable potting composition according to any preceding claim which is essentially free of surfactants, preferably less than 0.1% by weight of the composition, more preferably free of surfactants.

12. 12. The curable potting composition according to any one of claims 1 to 11, which is essentially free, preferably containing less than 0.1% by weight of the composition, and more preferably free, of substances of very high concern according to the EU REACH regulation and carcinogenic, mutagenic or reproductively toxic compounds according to the EU CLP regulation.

13. a first component comprising a polyfunctional acetoacetate compound; and a second member comprising a (meth)acrylate compound having at least three (meth)acrylate groups; where: At least one of the first member and the second member further includes a catalyst; At least one of the first member and the second member further comprises a filler; and the equivalent ratio of the (meth)acrylate compound having at least three (meth)acrylate groups to the polyfunctional acetoacetate compound is greater than 1.5; A two-component curing potting composition.

14. A cured product of the curable potting composition according to any one of claims 1 to 12 or the two-component curing potting composition according to claim 13.

15. Use of the curable potting composition according to any one of claims 1 to 12 or the two-component curing potting composition according to claim 13 in the manufacture of an electronic device.