Curable resin, curable resin composition, varnish, and cured product thereof

Abstract

The present invention provides a cured product which is excellent in solvent solubility and storage stability in a varnish state, and is excellent in dimensional stability and low dielectric properties. A curable resin which is obtained by reacting a vinylbenzyl compound (A) represented by the following formula (1) with a compound (B) having a pKa of less than 31 in a dimethyl sulfoxide solvent, and has an HSP distance from toluene of 2.5 or less. In formula (1), X represents a halogen atom. R1 represents an alkyl group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms which optionally has a substituent, and s is an integer of 0 to 4.

Description

Technical Field

[0001] This invention relates to curable resins, curable resin compositions, varnishes and cured products thereof, suitable for use in semiconductor sealing materials, printed wiring substrates, laminated boards and other electrical / electronic components, lightweight and high-strength materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and 3D printing applications. Background Technology

[0002] In recent years, laminates housing electrical / electronic components have required a wide range of sophisticated characteristics due to the expanding applications. While semiconductor chips were traditionally mounted on metal lead frames, high-performance semiconductor chips such as central processing units (CPUs) are increasingly being mounted on laminates made of polymer materials.

[0003] In semiconductor packages (hereinafter referred to as PKGs) used in smartphones and other devices, the goal is to reduce the thickness of the PKG substrate to meet the requirements of miniaturization, thinning, and high density. However, as the PKG substrate becomes thinner, its rigidity decreases, leading to defects such as significant warping due to heating during the soldering and mounting of the PKG onto the motherboard (PCB). To reduce this, there is a need for PKG substrate materials that can reduce dimensional changes from room temperature to the soldering and mounting temperature (260°C). Specifically, materials with high glass transition temperature (Tg), low thermal expansion (linear expansion coefficient α1 / linear expansion coefficient α2), and high elasticity at high temperatures can be cited (Patent Document 1, Non-Patent Documents 1, 2).

[0004] Furthermore, in the currently rapidly developing fifth-generation communication system "5G," it is expected to further increase capacity and high-speed communication. 5G will utilize higher frequencies, and to achieve high-speed communication using these frequencies, reducing transmission loss is crucial, requiring further low dielectric properties in the substrate material. Transmission loss on a printed circuit board originates from conductor loss and dielectric loss. As described in Non-Patent Document 3, dielectric loss α... D The relative permittivity ε of the dielectric r The square root of the dielectric loss is proportional to the tangent of the dielectric loss angle tanδ. Therefore, to reduce transmission loss, it can be said that improving the dielectric constant ε is related to the relative permittivity ε. r Compared to dielectric loss tangent tanδ, which contributes more to dielectric properties, thermoplastic materials such as PTFE (polytetrafluoroethylene) and LCP (liquid crystal polymer) are effective as low-dielectric materials, but they lack moldability compared to thermosetting resins. Therefore, it is desirable to develop thermosetting resins with excellent low-dielectric properties.

[0005] In view of this situation, in recent years, maleimide resins have been studied as materials for printed wiring boards in high-frequency regions. Maleimide resins are characterized by high heat resistance and small dimensional change due to their high crosslink density. In addition, due to their structural rigidity and symmetry, they are less susceptible to molecular vibration caused by high-frequency electromagnetic waves, and are also highly expected as materials exhibiting low dielectric properties. However, as also pointed out in Patent Document 2, bismaleimide compounds having an imide structure in the molecule have high crystallinity, and their melting point is as high as about 150°C, which is close to 170 to 180°C, the reference temperature for the onset of self-reaction. Therefore, they are materials that are difficult to use for preparing impregnating varnishes to perform impregnation and drying, or difficult to melt-mix with epoxy resins, curing agents, fillers and the like to produce molding materials.

[0006] Description of Related Art

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2023-179928

[0009] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2006-213823

[0010] Non-Patent Documents

[0011] Non-Patent Document 1: "Material Design of Bismaleimide-Based High Heat Resistance Resins", Network Polymer, Vol.38 No.3, 2017, pp. 144-152

[0012] Non-Patent Document 2: "Warpage Prediction Technology for Circuit Boards Reflecting Physical Property Changes Caused by Curing Shrinkage of Resins", Journal of the Japan Society for Intelligent Manufacturing, Vol. 8, No. 5, September 2019, pp. 184-189

[0013] Non-Patent Document 3: "Causes of Signal Loss in High-Speed Signal Transmission on Printed Boards", The 29th Spring Lecture Conference of The Institute of Electronics Packaging, Conference ID: 16P1-17, 2015 Contents of the Invention

[0014] Problems to be Solved by the Invention

[0015] The present invention has been made in view of such circumstances, and an object thereof is to provide a cured product that is also excellent in solvent solubility and storage stability in a varnish state, and further excellent in dimensional stability and low dielectric properties.

[0016] Means for Solving the Problems

[0017] That is, the present invention relates to the following [1]~

[12] . It should be noted that in the present invention, "(numerical value 1)~(numerical value 2)" means including upper and lower limits. [1]

[0019] A curable resin is prepared by reacting a vinyl benzyl compound (A) of formula (1) with a compound (B) in a dimethyl sulfoxide solvent having a pKa less than 31, wherein the curable resin has an HSP distance of less than 2.5 from toluene.

[0020]

[0021] In formula (1), X represents a halogen atom. R1 represents an alkyl group with 1 to 20 carbon atoms, or an aromatic group with 6 to 20 carbon atoms that may have a substituent, and s is an integer from 0 to 4. [2]

[0023] According to the curable resin described in the preceding paragraph [1], wherein the aforementioned compound (B) is a hydrocarbon compound and / or a carbonyl compound. [3]

[0025] According to the curable resin described in the preceding item [1], wherein the aforementioned compound (B) is a compound having at least one of the partial structures shown in the following formulas (2) to (5).

[0026]

[0027] In formula (2), Y2 represents an alkylene group, -O- group, or -C(=O)- group with 1 to 20 carbon atoms, optionally with a substituent. Multiple R2 groups exist independently, representing an alkyl group with 1 to 20 carbon atoms, or an aromatic group with 6 to 20 carbon atoms, optionally with a substituent. R2' represents a hydrogen atom, an alkyl group with 1 to 20 carbon atoms, or an aromatic group with 6 to 20 carbon atoms, optionally with a substituent. Multiple s2 groups exist independently, and are integers from 0 to 4. Dashed lines indicate that bonds may or may not be present.

[0028]

[0029] In formula (3), the multiple R3s exist independently, representing alkyl groups with 1 to 20 carbon atoms or optional aromatic groups with 6 to 20 carbon atoms having substituents, and s3 is an integer from 0 to 4. Dashed lines indicate that bonds may or may not be present.

[0030]

[0031] In formula (4), Y4 represents a directly bonded or optionally substituent alkylene group with 1 to 10 carbon atoms. Multiple R4 groups exist independently, representing alkyl groups with 1 to 20 carbon atoms, or optionally substituent alkyl groups with 6 to 20 carbon atoms, and s4 is an integer from 0 to 10. Dashed lines indicate that bonds may or may not be present.

[0032]

[0033] In formula (5), ring A represents a 5- to 8-membered aromatic ring. Multiple R5s exist independently, representing an alkyl group with 1 to 20 carbon atoms, or an aromatic group with 6 to 20 carbon atoms that may have substituents. s51 is an integer from 0 to 3, and s52 is 0 to the maximum number of substitutions. [4]

[0035] A curable resin composition comprising any one of the preceding items [1] to [3]. [5]

[0037] The curable resin composition according to the preceding item [4] further comprises at least one of the following: maleimide resin, polyphenylene ether compound, compound having olefinic unsaturated bond, cyanate ester resin, polybutadiene and its modified form, polystyrene and its modified form, polyethylene and its modified form, benzoxazine resin, epoxy resin, active ester compound, phenolic resin, amine resin, isocyanate ester resin, polyamide resin, polyimide resin, and active ester. [6]

[0039] The curable resin composition according to the preceding item [4] or [5] further contains a curing accelerator. [7]

[0041] The curable resin composition described in the preceding paragraphs [4] to [6] is used for printed wiring substrates. [8]

[0043] A varnish comprising any one of the preceding items [1] to [3] a curable resin and an organic solvent. [9]

[0045] A varnish comprising any one of the preceding items [4] to [7] a curable resin composition and an organic solvent.

[10]

[0047] A cured material obtained by curing the curable resin described in any one of the preceding items [1] to [3].

[12]

[0049] A cured product obtained by curing the curable resin composition described in any one of the preceding items [4] to [7].

[0050] The effects of the invention

[0051] According to the present invention, a cured product can be provided that has excellent solvent solubility and storage stability in the varnish state, as well as excellent dimensional stability and low dielectric properties. Detailed Implementation

[0052] Hereinafter, embodiments of the present invention (hereinafter also referred to as "this embodiment") will be described in more detail.

[0053] The curable resin of this embodiment is obtained by reacting a vinyl benzyl compound (A) (hereinafter also referred to as "vinyl compound (A)") as shown in formula (1) with a compound (B) (hereinafter also referred to as "compound (B)") in a dimethyl sulfoxide solvent with a pKa less than 31.

[0054]

[0055] In formula (1), X represents a halogen atom. The preferred halogen atom is a bromine atom or a chlorine atom. R1 represents an alkyl group with 1 to 20 carbon atoms, or optionally an aromatic group with 6 to 20 carbon atoms having substituents, and s is an integer from 0 to 4.

[0056] The pKa of compound (B) in dimethyl sulfoxide solvent in this embodiment is based on data published by Data Organic Chemistry, operated by the American Chemical Society. Additionally, compounds not described in this literature were calculated using computational chemistry methods published in known publications such as "Accurate pKa Determination for a Heterogeneous Group of Organic Molecules," ChemPhysChem 2004, Vol. 5, Issue 10, pp. 1513-1522. When the pKa of compound (B) is less than 31, under basic conditions, protons readily dissociate from compound (B), and the resulting anion of compound (B) attacks the halomethyl group in the vinylbenzyl compound (A). This, along with a dehydrohalogenation reaction, leads to the formation of a styrene compound. It should be noted that this reaction can be represented by the following formula.

[0057]

[0058] In the above formula, AH represents compound (B), and A -It is the anion of compound (B).

[0059] As the aforementioned compound (B), it is preferably a hydrocarbon compound or a carbonyl compound, and more preferably a compound having at least one of the partial structures shown in formulas (2) to (5).

[0060]

[0061] In formula (2), Y represents an alkylene group, -O- group, or -C(=O)- group with 1 to 20 carbon atoms, optionally with a substituent. The multiple R2 groups exist independently and represent an alkyl group with 1 to 20 carbon atoms, or an aromatic group with 6 to 20 carbon atoms, optionally with a substituent. R2' represents a hydrogen atom, an alkyl group with 1 to 20 carbon atoms, or an aromatic group with 1 to 20 carbon atoms, optionally with a substituent. The multiple s2 groups exist independently and are integers from 0 to 4. Dashed lines indicate that bonds may or may not be present.

[0062]

[0063] In formula (3), the multiple R3s exist independently, representing alkyl groups with 1 to 20 carbon atoms or optional aromatic groups with 6 to 20 carbon atoms having substituents, and s3 is an integer from 0 to 4. Dashed lines indicate that bonds may or may not be present.

[0064]

[0065] In formula (4), Y4 represents a directly bonded or optionally substituent alkylene group with 1 to 10 carbon atoms. Multiple R4 groups exist independently, representing alkyl groups with 1 to 20 carbon atoms, or optionally substituent alkyl groups with 6 to 20 carbon atoms, and s4 is an integer from 0 to 10. Dashed lines indicate that bonds may or may not be present.

[0066]

[0067] In formula (5), ring A represents a 5- to 8-membered aromatic ring. Multiple R5 groups exist independently, representing an alkyl group with 1 to 20 carbon atoms, or optionally an aromatic group with 6 to 20 carbon atoms and substituents. s51 is an integer from 0 to 3. s52 is 0 to the maximum number of substitutions. Regarding the maximum number of substitutions, it is 3 if ring A is a 5-membered ring, 4 if ring A is a 6-membered ring, 5 if ring A is a 7-membered ring, and 6 if ring A is an 8-membered ring.

[0068] Among the aforementioned compounds (B), examples of hydrocarbon compounds with pKa less than 31 include: 9,10-dihydroanthracene, 2-methyl-9,10-dihydroanthracene, 9-methyl-9,10-dihydroanthracene, 2-ethyl-9,10-dihydroanthracene, 9-ethyl-9,10-dihydroanthracene, 2,3-dimethyl-9,10-dihydroanthracene, 9,9-dimethyl-9,10-dihydroanthracene, 9,10-dimethyl-9,10-dihydroanthracene, dibenzo-1,4-pyran, 2-methyl-9H-xanthan, 4-methyl-9H-xanthan, 9-methyl-9H-xanthan, 2,4-dimethyl-9H-xanthan, 2,7-di... Methyl-9H-xanthones, 2,9-dimethyl-9H-xanthones, 3,6-dimethyl-9H-xanthones, 1,3,6,8-tetramethyl-9H-xanthones, 2,4,5,7-tetramethyl-9H-xanthones, 2-methyl-9-ethyl-9H-xanthones, 9-isopropyl-9H-xanthones, 4-tert-butyl-9H-xanthones, anthrone, 3-methylanthrone, 10-methylanthrene-9(10H)-one, indene, 1-methyl-1H-indene, 2-methyl-1H-indene, 3-methyl-1H-indene, 4-methyl-1H-indene, 5-methyl-1H-indene, 6-methyl-1H-indene, 7-methyl-1H-indene, 1, 2-Dimethyl-1H-indene, 1,3-Dimethyl-1H-indene, 2,3-Dimethyl-1H-indene, 2,4-Dimethyl-1H-indene, 4,5-Dimethyl-1H-indene, 4,6-Dimethyl-1H-indene, 4,7-Dimethyl-1H-indene, 5,6-Dimethyl-1H-indene, 5,7-Dimethyl-1H-indene, 6,7-Dimethyl-1H-indene, 1-Ethyl-1H-indene, 2-Ethyl-1H-indene, 2-Vinyl-1H-indene, 3-Vinyl-1H-indene, Fluorene, 1-Methyl-9H-fluorene, 2-Methyl-9H-fluorene, 3-Methyl-9H-fluorene, 4-Methyl-9H-fluorene, 9 The species include, but are not limited to, 1,3-dimethyl-9H-fluorene, 1,8-dimethyl-9H-fluorene, 2,3-dimethyl-9H-fluorene, 2,4-dimethyl-9H-fluorene, 2,5-dimethyl-9H-fluorene, 2,7-dimethyl-9H-fluorene, 2,9-dimethyl-9H-fluorene, 3,5-dimethyl-9H-fluorene, 3,6-dimethyl-9H-fluorene, 4,5-dimethyl-9H-fluorene, 2-ethyl-9H-fluorene, 3-ethyl-9H-fluorene, 4-ethyl-9H-fluorene, 9-ethyl-9H-fluorene, 2-ethynyl-9H-fluorene, 2-vinylfluorene, azulene, guaiazolinium, etc.

[0069] Among the aforementioned compounds (B), examples of carbonyl compounds with a pKa less than 31 include acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 3-methyl-2-butanone, 3-methyl-3-buten-2-one, 3-penten-2-one, 4-penten-2-one, methyl vinyl ketone, 3-butyn-2-one, cyclobutanone, 2-methylcyclobutanone, 3-methylcyclobutanone, 2-cyclobuten-1-one, cyclopentanone, 2-methylcyclopentanone, and 3-methylcyclopentanone. 2-Cyclopenten-1-one, 3-Cyclopenten-1-one, Cyclohexanone, 2-Methylcyclohexanone, 3-Methylcyclohexanone, 4-Methylcyclohexanone, Isophorone, Acetophenone, 2'-Methylacetophenone, 3'-Methylacetophenone, 4'-Methylacetophenone, Acetophenone, 2'-Methylacetophenone, 3'-Methylacetophenone, 4'-Methylacetophenone, Indane-1-one, Indane-2-one, Tetrahydronaphthyl-1-one, Tetrahydronaphthyl-2-one, etc., but not limited to these.

[0070] In addition, the aforementioned compound (B) can be a compound obtained by oligomerizing the above-exemplary compounds under any conditions, in acidic or alkaline conditions.

[0071] The method for preparing the curable resin in this embodiment is not particularly limited, and it is obtained by reacting vinylbenzyl compound (A) with compound (B). Specifically, it is obtained by reacting vinylbenzyl compound (A) with compound (B) in an aprotic polar solvent in the presence of an alkaline catalyst. Examples of aprotic polar solvents include dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolinone, and N-methylpyrrolidone, and two or more of them may be used in combination. In addition, a non-water-soluble solvent may be used in combination as needed. Examples of non-water-soluble solvents include aromatic solvents such as toluene and xylene; aliphatic solvents such as cyclohexane and n-hexane; ethers such as diethyl ether and diisopropyl ether; ester solvents such as ethyl acetate and butyl acetate; and ketone solvents such as methyl isobutyl ketone and cyclopentanone, but it is not limited to these, and two or more of them may be used in combination. The catalyst is not particularly limited, but basic catalysts such as sodium hydroxide, potassium hydroxide, potassium carbonate, sodium methoxide, sodium ethoxide, and potassium tert-butoxide can be listed. The order of adding vinylbenzyl compound (A), compound (B), and base can be changed as needed. Adding compound (B), an aprotic polar solvent, and base to fully ionize compound (B) makes the addition of vinylbenzyl compound (A) less likely to produce hydrolysates of vinylbenzyl compound (A), and is therefore preferred. The reaction rate is significantly reduced when the reaction does not use an aprotic polar solvent. In the absence of an aprotic polar solvent, a phase transfer catalyst is usually used for the reaction. In this case, the starting material is dissolved in a non-aqueous solvent such as toluene, and compound (B) reacts with vinylbenzyl compound (A) in the presence of an basic catalyst such as an aqueous solution of sodium hydroxide and a phase transfer catalyst such as tetrabutylammonium bromide. In this case, it is difficult to completely remove phase transfer catalysts such as tetrabutylammonium bromide, making it difficult to achieve low dielectric properties (low dielectric constant, low dielectric loss tangent). Furthermore, the residual phase transfer catalyst can cause problems such as ion migration when conducting long-term damp heat reliability tests on substrate materials obtained using the compounds of this invention. The reaction temperature is preferably 0-100°C, more preferably 0-80°C, and even more preferably 0-60°C. Above the upper limit, the compounds of this invention may undergo self-polymerization and gel. Below the lower limit, the reaction may not proceed sufficiently. An inhibitor may be included in the reaction stage as needed. As a post-reaction treatment, neutralization can be performed using any acid compound. Alternatively, alcohol compounds, water, etc., may be added to the reaction solution as needed to recover the target substance in the form of crystals. Alternatively, the obtained reaction solution or crystals may be redissolved in any solvent for an extraction process. Regarding the extraction process, aromatic hydrocarbon solvents such as toluene and xylene can be used alone, or non-aromatic hydrocarbons such as cyclohexane and toluene can be used in combination.After extraction, the organic layer is washed with water until the drainage is neutral, and the solvent is removed by distillation using an evaporator or similar method, thereby obtaining the target compound. Alternatively, to suppress viscosity, it can be prepolymerized by heating or similar means before use.

[0072] The curable resin of this embodiment exhibits excellent solubility in solvents. The type of solvent used is not limited; it can be dissolved in hydrocarbon solvents (toluene, xylene, mesitylene, etc.), ketone solvents (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, etc.), alcohol solvents (methanol, ethanol, isopropanol, butanol, etc.), and aprotic polar solvents (dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc.). For use in combination with materials possessing low polarity and low dielectric properties, solubility in hydrocarbon solvents is particularly preferred.

[0073] In this embodiment, the HSP distance Ra between the curable resin and toluene is 2.5 or less, preferably 2.3 or less. If the HSP distance is within the specified range, the solvent solubility in toluene is excellent. Here, the HSP distance is the distance between two points in Hansen space. The Hansen solubility parameters (HSP) are δd, δp, and δh, where δd represents the energy generated by intermolecular dispersion forces, δp represents the energy generated by intermolecular dipole interactions, and δh represents the energy generated by intermolecular hydrogen bonds. δd, δp, and δh can be considered as coordinates in three-dimensional space (Hansen space); the closer the distance (HSP distance) between two points, the easier it is for them to dissolve in each other.

[0074] The HSP distance Ra from toluene is calculated using the Hansen solubility parameter Ra, defined by the following formula, and can be obtained through the Hansen solubility parameter software (HSPiP: Hansen Solubility Parameter in Practice).

[0075] [Mathematical Expression 1]

[0076]

[0077] In the above formula, Ra is the HSP distance between the curable resin of this embodiment and toluene, δd1 represents the energy generated by the dispersion force between toluene molecules, δd2 represents the energy generated by the dispersion force between the molecules of the curable resin of this embodiment, δp1 represents the energy generated by the dipole interaction between toluene molecules, δp2 represents the energy generated by the dipole interaction between the molecules of the curable resin of this embodiment, δh1 represents the energy generated by the hydrogen bond between toluene molecules, and δh2 represents the energy generated by the hydrogen bond between the molecules of the curable resin of this embodiment. That is, (δd1, δp1, δh1) represent the coordinates of toluene in Hansen space, and (δd2, δp2, δh2) represent the coordinates of the curable resin of this embodiment in Hansen space.

[0078] The curable resin composition of this embodiment only needs to contain the curable resin of this embodiment, and any known material can be used. Specifically, examples include maleimide resin, phenolic resin, epoxy resin, amine resin, compound containing olefin unsaturated bonds, isocyanate resin, polyamide resin, polyimide resin, cyanate ester resin, acrylic resin, methanallyl resin, reactive ester resin, benzoxazine resin, etc., and one or more can be used. In addition, from the perspective of balancing heat resistance, adhesion, and dielectric properties, it is preferable to include epoxy resin, compound containing olefin unsaturated bonds, and cyanate ester resin. By containing these curable resins, the brittleness of the cured product can be improved and the adhesion to the metal can be enhanced, and cracking of the package can be suppressed during reliability tests such as reflow soldering and thermal cycling. The amount of these curable resins relative to the curable resin of this embodiment is preferably 10 times or less by weight, more preferably 5 times or less by weight, and particularly preferably 3 times or less by weight. In addition, the preferred lower limit is 0.5 times or more by weight, more preferably 1 time or more by weight. If the amount is less than 10 times the weight, the heat resistance and dielectric properties of the curable resin of this embodiment can be achieved.

[0079] As the above-mentioned maleimide resin, phenolic resin, epoxy resin, amine resin, compound containing olefinic unsaturated bonds, isocyanate resin, polyamide resin, polyimide resin, cyanate resin, reactive ester resin, benzoxazine resin, the following exemplified resins may be used.

[0080] Maleimide resins: 4,4'-diphenylmethane bismaleimide, polyphenylmethane maleimide, m-phenylene bismaleimide, 2,2'-bis[4-(4-maleimidephenoxy)phenyl]propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 4,4'-diphenyl ether bismaleimide, 4,4'-diphenyl sulfone bismaleimide, 1,3-bis(3-maleimidephenoxy)benzene, 1,3-bis(4-maleimidephenoxy)benzene), XYLOK type maleimide compounds (Anilix maleimide, Mitsui Chemicals) (Made by Fine Corporation), biphenyl aralkyl type maleimide compounds (compounds obtained by solidification by distilling off the solvent from a resin solution containing maleimide compound (M2) described in Example 4 of Japanese Patent Application Publication No. 2009-001783 under reduced pressure), diaminocumylbenzene type maleimide (maleimide compound described in International Publication No. 2020 / 054601), maleimide compounds having an indane structure described in Japanese Patent No. 6629692 or International Publication No. 2020 / 217679, MATERIAL STAGE Vol. 18, No. 12 The maleimide compound described in 2019 "~Continued·Epoxy Resin CAS Number Story~ Curing Agent CAS Number Memorandum Chapter 31 Bismaleimide (1) " ", MATERIALSTAGE Vol.19, No.2 2019 "~Continued·Epoxy Resin CAS Number Story~ Curing Agent CAS Number Memorandum Chapter 32 Bismaleimide (2) " "

[0081] Phenolic resins are polymers of phenols (phenol, alkyl-substituted phenols, aromatic-substituted phenols, hydroquinone, resorcinol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.) and various aldehydes (formaldehyde, acetaldehyde, alkyl aldehydes, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzene, naphthaldehyde, glutaraldehyde, phenylenedialdehyde, crotonaldehyde, cinnamaldehyde, furfural, etc.); and phenols and various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, norbornene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropylene). Polymers of bisphenols, butadiene, isoprene, etc.; condensation polymers of phenols and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc.); phenolic resins obtained by condensation polymerization of phenols with substituted biphenyls (4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'-bis(methoxymethyl)-1,1'-biphenyl, etc.) or substituted phenyls (1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene and 1,4-bis(hydroxymethyl)benzene, etc.); condensation polymers of bisphenols and various aldehydes; and polyphenylene ether compounds.

[0082] As the polyphenylene ether compound, any known polyphenylene ether compound can be used. From the viewpoint of heat resistance and electrical properties, polyphenylene ether compounds having olefinic unsaturated double bonds are preferred, and polyphenylene ether compounds having acryloyl, methacryl, or styrene structures are even more preferred. Examples of commercially available products include SA-9000-111 (manufactured by SABIC Corporation, a polyphenylene ether compound having a methacryl group), OPE (registered trademark)-2St 1200, and OPE-2St 2200 (manufactured by Mitsubishi Gas Chemical Corporation, a polyphenylene ether compound having a styrene structure).

[0083] The number-average molecular weight (Mn) of the polyphenylene ether compound is preferably 500 to 5000, more preferably 2000 to 5000, and even more preferably 2000 to 4000. When the molecular weight is less than 500, the heat resistance of the cured product tends to be insufficient. Furthermore, if the molecular weight is greater than 5000, the melt viscosity becomes high, making it difficult to achieve sufficient flowability, thus leading to a tendency for poor molding. Additionally, the reactivity decreases, the curing reaction requires a longer time, the amount of unreacted substances that do not enter the curing system increases, the glass transition temperature of the cured product decreases, and the heat resistance of the cured product decreases.

[0084] If the number-average molecular weight of the polyphenylene ether compound is 500-5000, it can exhibit excellent heat resistance and moldability while maintaining excellent dielectric properties. It should be noted that the number-average molecular weight can be determined using methods such as gel permeation chromatography.

[0085] Polyphenylene ether compounds can be obtained through polymerization reactions or by redistributing high molecular weight polyphenylene ether compounds with a number average molecular weight of approximately 10,000 to 30,000. Alternatively, they can be used as raw materials to react with compounds containing olefinic unsaturated double bonds, such as methacryloyl chloride, acryloyl chloride, and chloromethylstyrene, thereby imparting free radical polymerization properties. Polyphenylene ether compounds obtained through redistribution reactions can be obtained, for example, by heating high molecular weight polyphenylene ether compounds in a solvent such as toluene in the presence of a phenolic compound and a free radical initiator. Polyphenylene ether compounds obtained through redistribution reactions in this way have hydroxyl groups from phenolic compounds at both ends of the molecular chain that facilitate curing. Therefore, in addition to maintaining higher heat resistance, functional groups can be introduced to both ends of the molecular chain after modification with compounds containing olefinic unsaturated double bonds, which is preferable. Furthermore, from the perspective of exhibiting excellent flowability, polyphenylene ether compounds obtained through polymerization reactions are preferred.

[0086] In the case of polyphenylene ether compounds obtained through polymerization, the molecular weight of the polyphenylene ether compound can be adjusted by adjusting the polymerization conditions, etc. Furthermore, in the case of polyphenylene ether compounds obtained through redistribution reactions, the molecular weight of the obtained polyphenylene ether compound can be adjusted by adjusting the conditions of the redistribution reaction, etc. More specifically, the amount of phenolic compounds used in the redistribution reaction can be adjusted. That is, the more phenolic compounds are used, the lower the molecular weight of the obtained polyphenylene ether compound. In this case, poly(2,6-dimethyl-1,4-phenylene ether) and the like can be used as high molecular weight polyphenylene ether compounds to undergo the redistribution reaction. Furthermore, there are no particular limitations on the phenolic compounds used in the above-mentioned redistribution reactions, but polyfunctional phenolic compounds having two or more phenolic hydroxyl groups in their molecules, such as bisphenol A, phenolic varnish, and cresol varnish, are preferred. They can be used alone or in combination of two or more.

[0087] Furthermore, the content of the polyphenylene ether compound is not particularly limited, but is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, relative to the total weight of the curable resin components. When the content of the polyphenylene ether compound is 10 to 90% by weight, a cured product can be obtained that not only has excellent heat resistance, but also fully utilizes the excellent dielectric properties of the polyphenylene ether compound, which is preferred from this point of view.

[0088] Epoxy resins include: glycidyl ether epoxy resins obtained by glycidylating the above-mentioned phenolic resins, alcohols, etc.; alicyclic epoxy resins represented by 4-vinyl-1-cyclohexene diepoxide and 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexane carboxylate; glycidylamine epoxy resins represented by tetraglycidyldiaminodiphenylmethane (TGDDM) and triglycidyl-p-aminophenol; and glycidyl ester epoxy resins.

[0089] Amine resins: diaminodiphenylmethane, diaminodiphenyl sulfone, isophorone diamine, naphthyldiamine, aniline phenolic varnish, o-ethylaniline phenolic varnish, aniline resin obtained by reacting aniline with dichloroxylene; amine resin obtained by reacting aniline with substituted biphenyls (4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'-bis(methoxymethyl)-1,1'-biphenyl, etc.) or substituted phenyls (1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene and 1,4-bis(hydroxymethyl)benzene, etc.) as described in Japanese Patent No. 6429862.

[0090] Compounds containing olefinic unsaturated bonds: condensation polymers of the aforementioned phenolic resins and halogenated compounds containing olefinic unsaturated bonds (chloromethylstyrene, allyl chloride, methyl allyl chloride, acryloyl chloride, allyl chloride, etc.); phenols containing olefinic unsaturated bonds (2-allylphenol, 2-propenylphenol, 4-allylphenol, 4-propenylphenol, eugenol, isoeugenol, etc.) and halogenated compounds (4,4'-bis(methoxy)... Condensations of methyl 1,1'-biphenyl, 1,4-bis(chloromethyl)benzene, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, cyanuric chloride, etc.; condensations of epoxy resins or alcohols with substituted or unsubstituted acrylates (acrylates, methacrylates, etc.); styrene resins; allyl-containing compounds; acenaphthene-containing compounds (acenaphthene, etc.); isocyanuric acid derivatives. (TAIC manufactured by Mitsubishi Chemical Corporation, MA-DGIC, DA-MGIC, MeDAIC, L-DAIC, DD-1, etc. manufactured by Shikoku Chemical Corporation), maleimide compounds (phenylmaleimide, 4,4'-diphenylmethane bismaleimide, polyphenylmethane maleimide, m-phenylene bismaleimide, 2,2'-bis[4-(4-maleimide phenoxy)phenyl]propane, 3) 3'-Dimethyl-5,5'-Diethyl-4,4'-Diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 4,4'-diphenyl ether bismaleimide, 4,4'-diphenyl sulfone bismaleimide, 1,3-bis(3-maleimide phenoxy)benzene, 1,3-bis(4-maleimide phenoxy)benzene), XYLOC type maleimide resin (Anilix maleimide, manufactured by Mitsui Chemicals Fine), biphenyl aralkyl type maleimide resin (a resin obtained by solidification by distilling off the solvent from a resin solution containing maleimide resin (M2) described in Example 4 of Japanese Patent Application Publication No. 2009-001783 under reduced pressure), and diaminocumylbenzene type maleimide (maleimide resin described in International Publication No. 2020 / 054601).

[0091] Isocyanate resins include: aromatic diisocyanates such as terephthalic diisocyanate, isophthalic diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and naphthalene diisocyanate; aliphatic or alicyclic diisocyanates such as isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hydrogenated xylene diisocyanate, norbornene diisocyanate, and lysine diisocyanate; polyisocyanates such as one or more biuret forms of isocyanate monomers or isocyanates formed by trimerization of the above diisocyanate compounds; and polyisocyanates obtained by urethane reaction of the above isocyanate compounds with polyol compounds.

[0092] Polyamide resin: a polymer that uses one or more of the following as main raw materials: amino acids (6-aminohexanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, p-aminomethylbenzoic acid, etc.) and lactams (ε-caprolactam, ω-undecanolactam, ω-laurolactam); or a polymer that uses one or more diamines and one or more dicarboxylic acids as main raw materials.

[0093] Diamines include: ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecanediamine, heptadecanediamine, octadecanediamine, nonadecanediamine, eicosanediamine, 2-methyl-1,5-diaminopentane, 2-methyl-1,8-diaminooctane, and other aliphatic diamines; cyclohexanediamine, bis-(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, and other alicyclic diamines; and phenylenediamine and other aromatic diamines.

[0094] Dicarboxylic acids: aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, and dodecanoic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, sodium isophthalate-5-sulfonate, hexahydroterephthalic acid, and hexahydroisophthalic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; and dialkyl esters and diacyl chlorides of these dicarboxylic acids.

[0095] Polyimide resin: the condensation polymer of the aforementioned diamine and tetracarboxylic dianhydride.

[0096] Tetracarboxylic acid dianhydrides: 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-cyclohexene-1,2-dicarboxylic anhydride, pyromellitic dianhydride, 1,2,3,4-phenyltetracarboxylic anhydride, 3,3',4,4'-benzophenone tetracarboxylic anhydride, 2,2',3,3'-benzophenone tetracarboxylic anhydride, 3,3',4,4'-biphenyltetracarboxylic anhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic anhydride, 2,2',3,3'-biphenyltetracarboxylic anhydride, methylene-4,4'-diphthalic anhydride, 1,1-ethoxy-4,4'-diphthalic anhydride, 2,2'-propylidene-4,4'-diphthalic anhydride, 1,2 -Ethylene-4,4'-diphthalic anhydride, 1,3-trimethylene-4,4'-diphthalic anhydride, 1,4-tetramethylene-4,4'-diphthalic anhydride, 1,5-pentamethylene-4,4'-diphthalic anhydride, 4,4'-oxodiphthalic anhydride, thio-4,4'-diphthalic anhydride, sulfonyl-4,4'-diphthalic anhydride, 1,3-bis(3,4-dicarboxyphenyl)phthalic anhydride, 1,3-bis(3,4-dicarboxyphenoxy)phthalic anhydride, 1,4-bis(3,4-dicarboxyphenoxy)phthalic anhydride, 1,3-bis[2-(3,4-dicarboxyphenyl)-2-propyl]phthalic anhydride, 1,4-bis[2-(3,4-dicarboxyphenyl)-2-propyl]phthalic anhydride [-propyl] phenyl dianhydride, bis[3-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, bis[4-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, 2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, bis(3,4-dicarboxyphenoxy)dimethylsilane dianhydride, 1,3-bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, 3,4,9,10-perylenetetracarboxylic acid dianhydride, 2,3,6,7-anthracitetetracarboxylic acid dianhydride, 1,2,7 8-Phenylacetyl dianhydride, ethylenetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, 3,3',4,4'-dicyclohexanetetracarboxylic dianhydride, carbonyl-4,4' -Di(cyclohexane-1,2-dicarboxylic acid) dianhydride, methylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,2-ethylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,1-ethide-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 2,2-propionide-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride2-Dicarboxylic acid) dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, thio-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, rel-[1S,5R,6R]-3-oxabicyclo[3, [2,1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, ethylene glycol-bis-(3,4-dicarboxylic anhydride phenyl) ether, 4,4'-biphenylbis(triphenyltriester anhydride), 9,9'-bis(3,4-dicarboxyphenyl)fluorene dihydride.

[0097] Cyanate ester resins are cyanate ester compounds obtained by reacting phenolic resins with cyanide halides. Specific examples include: dicyanophenyl, tricyanophenyl, dicyanonaphthalene, dicyanobiphenyl, 2,2'-bis(4-cyanophenyl)propane (BisA-OCN, manufactured by Mitsubishi Gas Chemical Company), bis(4-cyanophenyl)methane, bis(3,5-dimethyl-4-cyanophenyl)methane, 2,2'-bis(3,5-dimethyl-4-cyanophenyl)propane, 2,2'-bis(4-cyanophenyl)ethane, 2,2'-bis(4-cyanophenyl)hexafluoropropane, bis(4-cyanophenyl)sulfone, bis(4-cyanophenyl) sulfide, phenolic varnish cyanate ester, and substances obtained by converting the hydroxyl groups of a phenol-dicyclopentadiene cocondensate to cyanate ester groups, etc., but are not limited to these.

[0098] Furthermore, the cyanate ester compound for which the synthesis method is described in Japanese Patent Application Publication No. 2005-264154 is particularly preferred as a cyanate ester compound due to its low hygroscopicity, flame retardancy, and excellent dielectric properties.

[0099] In cyanate ester resins, catalysts such as zinc naphthenate, cobalt naphthenate, copper naphthenate, lead naphthenate, zinc octanoate, tin octanoate, lead acetylacetone, dibutyltin maleate, and 18% Octope Zn (manufactured by Hope Chemical Co., Ltd.), which are commercially available, may be included to induce the trimerization of the cyanate ester groups and form a mesityrazine ring. The catalyst is typically used in amounts of 0.0001 to 0.10 parts by weight relative to 100 parts by weight of the total weight of the curable resin composition, and preferably 0.00015 to 0.0015 parts by weight.

[0100] Reactive ester resin: As a curing agent for curable resins other than the maleimide resin mixture of this embodiment, such as epoxy resin, a compound having one or more active ester groups per molecule can be used as needed. Preferably, the reactive ester resin is a compound having two or more highly reactive ester groups per molecule, such as phenolic esters, thiophenolic esters, N-hydroxyamine esters, or esters of heterocyclic hydroxyl compounds. This reactive ester resin is preferably obtained by a condensation reaction of at least one of a carboxylic acid compound and a thiocarboxylic acid compound with at least one of a hydroxyl compound and a thiol compound. Particularly from the viewpoint of improved heat resistance, reactive ester resins obtained from carboxylic acid compounds and hydroxyl compounds are preferred, and reactive ester resins obtained from carboxylic acid compounds and at least one of a phenolic compound and a naphthol compound are even more preferred.

[0101] Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

[0102] Examples of phenolic or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthol, 1,6-dihydroxynaphthol, 2,6-dihydroxynaphthol, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, pyroglucinol, dicyclopentadiene-type diphenol compounds, and phenolic varnishes. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing two molecules of phenol onto one molecule of dicyclopentadiene.

[0103] Preferred examples of reactive ester resins include reactive ester resins containing a dicyclopentadiene-type diphenol structure, reactive ester resins containing a naphthalene structure, reactive ester resins containing an acetylated form of phenolic varnish, and reactive ester resins containing a benzoylated form of phenolic varnish. More preferably, reactive ester resins containing a naphthalene structure and reactive ester resins containing a dicyclopentadiene-type diphenol structure are preferred. "Dicyclopentadiene-type diphenol structure" refers to a divalent structural unit formed from a phenylene-dicyclopentylene-phenylene group.

[0104] Commercially available reactive ester resins include, for example, reactive ester resins containing a dicyclopentadiene-type diphenol structure such as "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", "HPC-8000H-65TM", "EXB-8000L-65TM", and "EXB-8150-65T" (manufactured by DIC Corporation); and reactive ester resins containing a bisphenol A type structure such as "Unifiner". Series (manufactured by UNITIKA); as an active ester resin containing a naphthalene structure, "EXB9416-70BK" (manufactured by DIC Corporation) can be listed; as an active ester resin containing an acetylated compound of phenolic varnish, "DC808" (manufactured by Mitsubishi Chemical Corporation) can be listed; as an active ester resin containing a benzoyl compound of phenolic varnish, "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) can be listed; as an active ester resin belonging to the acetylated compound of phenolic varnish, "DC808" (manufactured by Mitsubishi Chemical Corporation) can be listed; as an active ester resin containing phosphorus atoms, "EXB-9050L-62M" manufactured by DIC Corporation can be listed, etc.

[0105] Benzoxazine resins: There are no particular restrictions on benzoxazine resins as long as they have two or more benzoxazine rings within a single molecule. For example, they can be obtained by reacting phenolic compounds, amine compounds, and aldehyde compounds with heat. The phenolic and amine compounds that can be used here are as described above. Examples of aldehyde compounds include formaldehyde, acetaldehyde, alkyl aldehydes, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, benzoxaldehyde, crotonaldehyde, cinnamaldehyde, furfural, etc.

[0106] The curable composition of this embodiment may contain a polymerization inhibitor. By containing a polymerization inhibitor, storage stability is improved, and the reaction initiation temperature can be controlled. Controlling the reaction initiation temperature makes it easier to ensure flowability, does not impair impregnation with glass cloth, and facilitates B-stage processes such as prepreg preparation. If the polymerization reaction is excessive during prepreg preparation, adverse conditions such as difficulty in lamination during the lamination process can easily occur.

[0107] Examples of usable polymerization inhibitors include phenolic, sulfur-based, phosphorus-based, hindered amine-based, nitroso-based, and nitroyl radical-based inhibitors. The inhibitor can be added during the synthesis of the maleimide resin mixture of this embodiment, or it can be added after synthesis. Furthermore, two or more inhibitors can be used alone or in combination. The amount of inhibitor used is typically 0.008 to 1 part by weight, preferably 0.01 to 0.5 parts by weight, relative to 100 parts by weight of the resin component. These inhibitors can be used alone or in combination. In this embodiment, phenolic, hindered amine, nitroso, and nitroyl radical-based inhibitors are preferred.

[0108] Specific examples of phenolic polymerization inhibitors include monophenols such as 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-p-ethylphenol, stearyl-β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylaniline)-1,3,5-triazine, and 2,4-bis[(octylthio)methyl]-o-cresol; 2,2'-methylenebis... (4-Methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrogenated cinnamon) amides), 2,2-thio-diethylidene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 3,9-bis[1,1-dimethyl-2-{β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane, bis(3,5-di-tert-butyl-4-hydroxybenzylsulfonate ethyl ester) calcium and other bisphenols; 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butyl-4-hydroxybenzylsulfonate) High molecular weight phenols include butylphenyl butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tetra-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-tert-butylphenyl)butyrate]diol ester, tris(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate, 1,3,5-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-triazine-2,4,6-(1H,3H,5H)trione, and tocopherol.

[0109] Specific examples of sulfur-based polymerization inhibitors include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearate-3,3'-thiodipropionate.

[0110] Specific examples of phosphorus-based polymerization inhibitors include triphenyl phosphite, diphenyl isodecanyl phosphite, phenyl diisodecyl phosphite, tri(nonylphenyl) phosphite, diisodecyl pentaerythritol phosphite, tris(2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetrayl bis(octadecyl) phosphite, cyclic neopentanetetrayl bis(2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetrayl bis(2,4-di-tert-butyl-4-methylphenyl) phosphite, and phosphorus... Phosphite esters such as bis[2-tert-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl] ester; oxaphosphazene oxides such as 9,10-dihydro-9-oxa-10-phosphazene-10-oxide, 10-(3,5-di-tert-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphazene-10-oxide, and 10-decoxy-9,10-dihydro-9-oxa-10-phosphazene-10-oxide.

[0111] Specific examples of hindered amine polymerization inhibitors include ADK STAB (registered trademark) LA-40MP, ADK STAB LA-40Si, ADK STAB LA-402AF, ADK STAB LA-87, ADK STAB LA-82, ADK STAB LA-81, ADK STAB LA-77Y, ADK STAB LA-77G, ADK STAB LA-72, ADK STAB LA-68, ADK STAB LA-63P, ADK STAB LA-57, and ADK STAB... LA-52 (and above, manufactured by ADEKA), Chimassorb (registered trademark) 2020FDL, Chimassorb944FDL, Chimassorb944LD, Tinuvin (registered trademark) 622SF, Tinuvin PA144, Tinuvin 765, Tinuvin 770DF, Tinuvin XT55FB, Tinuvin 111FDL, Tinuvin 783FDL, Tinuvin 791FB (manufactured by BASF), etc., but not limited to these.

[0112] Specific examples of nitrosyl-based polymerization inhibitors include p-nitrosophenol, N-nitrosodiphenylamine, ammonium salts of N-nitrosophenylhydroxylamine, and (copper ferroin), with ammonium salts of N-nitrosophenylhydroxylamine (copper ferroin) being preferred.

[0113] Specific examples of nitryl radical-based polymerization inhibitors include di-tert-butylnitrooxy, 2,2,6,6-tetramethylpiperidine-1-oxy radical, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy radical, 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxy radical, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxy radical, 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxy radical, 4-acetoxy-2,2,6,6-tetramethylpiperidine-1-oxy radical, and 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxy radical, but are not limited to these.

[0114] The curable resin composition of this embodiment can also be used with a curing accelerator (curing catalyst) to improve curability. As a specific example of a curing accelerator that can be used, a free radical polymerization initiator is preferably used for the purpose of promoting the self-polymerization of curable resins that are free radical polymerizable, such as olefin compounds and maleimide resins, as well as the free radical polymerization with other components. Examples of usable free radical polymerization initiators include peroxide ketones such as methyl ethyl ketone peroxide and acetylacetone peroxide; diacyl peroxides such as benzoyl peroxide; dialkyl peroxides such as dicumyl peroxide and 1,3-bis-(tert-butylperoxyisopropyl)benzene; peroxide ketals such as tert-butyl peroxide and 1,1-di-tert-butylperoxycyclohexane; and peroxide ketals such as α-cumyl peroxide, tert-butyl peroxide, tert-butyl peroxide, 1,1,3,3-tetramethyl butyl peroxide-2-ethylhexanoate, tert-pentyl peroxide-2-ethylhexanoate, and tert-butyl peroxide-3,5,5-trimethyl peroxide. Alkyl peresters such as tert-amyl hexanoate, tert-butyl peroxide-3,5,5-trimethylhexanoate, and tert-amyl peroxybenzoate; peroxycarbonates such as di-2-ethylhexyl peroxydicarbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, tert-butyl peroxyisopropyl carbonate, and 1,6-bis(tert-butylperoxycarbonyloxy)hexane; organic peroxides such as tert-butyl hydroperoxide, cumyl hydroperoxide, tert-butyl peroxyoctanoate, and lauroyl peroxide; and azo compounds such as azobisisobutyronitrile, 4,4'-azobis(4-cyanopentanoic acid), and 2,2'-azobis(2,4-dimethylpentanonitrile), are known curing accelerators, but are not particularly limited to these. Ketone peroxides, diacyl peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, alkyl peresters, and percarbonates are preferred, with dialkyl peroxides being more preferred. The amount of free radical polymerization initiator added is preferably 0.01 to 5 parts by weight, and particularly preferably 0.01 to 3 parts by weight, relative to 100 parts by weight of the curable resin composition. If a large amount of free radical polymerization initiator is used, the molecular weight will not increase sufficiently during the polymerization reaction.

[0115] Additionally, curing accelerators other than free radical polymerization initiators can be added or used in combination as needed. Specific examples of usable curing accelerators include imidazoles such as 2-methylimidazole, 2-ethylimidazole, and 2-ethyl-4-methylimidazole; tertiary amines such as 2-(dimethylaminomethyl)phenol and 1,8-diaza-bicyclo(5,4,0)undecene-7; phosphines such as triphenylphosphine; and quaternary ammonium salts such as tetrabutylammonium salt, triisopropylmethylammonium salt, trimethyldecylammonium salt, hexadecyltrimethylammonium salt, and hexadecyltrimethylammonium hydroxide. Transition metal compounds (transition metal salts) such as quaternary phosphonium salts (such as phenylbenzylphosphonium salt, triphenylethylphosphonium salt, and tetrabutylphosphonium salt; the counter ions of the quaternary salts are halogens, organic acid ions, hydroxide ions, etc., without special specification, but organic acid ions and hydroxide ions are particularly preferred), zinc compounds such as tin octoate, zinc carboxylate (zinc 2-ethylhexanoate, zinc stearate, zinc behenate, zinc myristate), and zinc phosphate esters (zinc octyl phosphate, zinc stearyl phosphate, etc.). Regarding the mixing amount of the curing accelerator, relative to 100 parts by weight of epoxy resin, 0.01 to 5.0 parts by weight may be used as needed.

[0116] The curable resin composition of this embodiment may also contain a phosphorus-containing compound as a flame-retardant imparting component. The phosphorus-containing compound may be a reactive compound or an additive compound. Specific examples of phosphorus-containing compounds include trimethyl phosphate, triethyl phosphate, tricresyl phosphate, tri(xylyl) phosphate, toluene diphenyl phosphate, toluene-2,6-di(xylyl) phosphate, 1,3-phenylenebis(di(xylyl) phosphate), 1,4-phenylenebis(di(xylyl) phosphate), 4,4'-biphenyl(di(xylyl) phosphate), and other phosphate esters; 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxa Phosphine compounds such as 10(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide; phosphorus-containing epoxy compounds obtained by reacting epoxy resin with the active hydrogen of the above-mentioned phosphine compounds; red phosphorus; preferably phosphate esters, phosphine compounds, or phosphorus-containing epoxy compounds, particularly preferably 1,3-phenylenebis(di(xylyl)phosphate), 1,4-phenylenebis(di(xylyl)phosphate), 4,4'-biphenyl(di(xylyl)phosphate), or phosphorus-containing epoxy compounds. Regarding the content of phosphorus-containing compounds, the ratio of (phosphine-containing compounds) to (total epoxy resin) is preferably in the range of 0.1 to 0.6 (by weight). Below 0.1, flame retardancy is insufficient; above 0.6, it may adversely affect the hygroscopicity and dielectric properties of the cured product.

[0117] Furthermore, a light stabilizer may be added to the curable resin composition of this embodiment as needed. Suitable light stabilizers are hindered amine light stabilizers (HALS), etc. As HALS, there are no particular limitations. Representative examples include the condensation polymers of dibutylamine·1,3,5-triazine·N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidinyl)butylamine, dimethyl succinate-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidinyl condensate, and poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidinyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4- HALS can be formulated using one or more of the following: [piperidinyl]imino, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate, bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidinyl)sebacate, 2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonate bis(1,2,2,6,6-pentamethyl-4-piperidinyl), etc.

[0118] Furthermore, in the curable resin composition of this embodiment, an adhesive resin may also be incorporated as needed. Examples of adhesive resins include butyral resins, acetal resins, acrylic resins, epoxy-nylon resins, NBR-phenol resins, epoxy-NBR resins, polyamide resins, polyimide resins, and silicone resins, but are not limited to these. The amount of adhesive resin incorporated is preferably within a range that does not impair the flame retardancy and heat resistance of the cured product, preferably 0.05 to 50 parts by weight relative to 100 parts by weight of the resin component, and more preferably 0.05 to 20 parts by weight as needed.

[0119] Furthermore, in the curable resin composition of this embodiment, powders such as fused silica, crystalline silica, porous silica, alumina, zircon, calcium silicate, calcium carbonate, quartz powder, silicon carbide, silicon nitride, boron nitride, zirconium oxide, aluminum nitride, graphite, forsterite, block talc, spinel, mullite, titanium dioxide, talc, clay, iron oxide asbestos, and glass powder can be added as needed; or inorganic filler materials obtained by forming them into spherical or broken shapes. In particular, when obtaining a curable resin composition for semiconductor sealing, the amount of the aforementioned inorganic filler material in the curable resin composition is typically in the range of 80-92% by weight, preferably 83-90% by weight.

[0120] In the curable resin composition of this embodiment, known additives can be incorporated as needed. Specific examples of usable additives include surface treatment agents for fillers such as polybutadiene and its modified forms, modified acrylonitrile copolymers, polyphenylene ether, polystyrene, polyethylene, polyimide, fluoropolymers, silicone, silicone oil, and silane coupling agents, mold release agents, carbon black, phthalocyanine blue, and phthalocyanine green colorants. The amount of these additives incorporated relative to 100 parts by weight of the curable resin composition is preferably 1,000 parts by weight or less, more preferably 700 parts by weight or less. From the viewpoints of low water absorption and electrical properties, polybutadiene and its modified forms, polyphenylene ether, polystyrene, polyethylene, and fluoropolymers are preferred. From the viewpoints of electrical properties, adhesion, and low water absorption, polybutadiene and its modified forms are preferred. Specifically, examples include butadiene-based thermoplastic elastomers such as styrene-butadiene copolymers (SBR: RICON-100, RICON-181, RICON-184, all manufactured by Cray Valley Corporation), and acrylonitrile-butadiene copolymers; and styrene-based thermoplastic elastomers such as styrene-butadiene-styrene copolymers (SBS), hydrogenated styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers (SIS), hydrogenated styrene-isoprene-styrene copolymers, and hydrogenated styrene (butadiene / isoprene)-styrene copolymers. These styrene-based thermoplastic elastomers can be used alone or in combination of two or more. Among these high molecular weight copolymers, styrene-based thermoplastic elastomers such as styrene-butadiene-styrene copolymer, hydrogenated styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer, hydrogenated styrene-isoprene-styrene copolymer, and hydrogenated styrene (butadiene / isoprene)-styrene copolymer are preferred. In particular, styrene-isoprene-styrene copolymer, hydrogenated styrene-butadiene-styrene copolymer, hydrogenated styrene-isoprene-styrene copolymer, and hydrogenated styrene (butadiene / isoprene)-styrene copolymer have higher heat resistance and are not easily oxidized and deteriorated, and are therefore further preferred.Specifically, as long as Septon 1020, Septon 2002, Septon 2004F, Septon 2005, Septon 2006, Septon 2063, Septon 2104, Septon 4003, Septon 4044, Septon 4055, Septon 4077, Septon 4099, Septon 8004, Septon 8006, Septon 8007L, Septon HG252, Septon V9827, Hybrar 7125 (hydrogenated), Hybrar There are no particular restrictions on the weight average molecular weight of 7215F, Hybrar7311F (both manufactured by Kuraray), or styrene-based thermoplastic elastomers of 10,000 or higher. However, if the weight average molecular weight is too high, the compatibility with low molecular weight components with a weight average molecular weight of around 50-1000 and oligomer components with a weight average molecular weight of around 1000-5000, in addition to polyphenylene ether compounds, becomes worse, making it difficult to ensure mixing and solvent stability. Therefore, a weight average molecular weight of around 10,000-300,000 is preferred. Generally, in the case of compounds containing heteroatoms such as bismaleimide and polymaleimide, due to their polarity, it is difficult to ensure compatibility with low-polarity compounds such as those mainly composed of hydrocarbons or compounds composed only of hydrocarbons among the above-mentioned additives and curable resin components. On the other hand, the curable resin of this embodiment has excellent compatibility with materials with low polarity and low dielectric properties, and compounds composed only of hydrocarbons, because it does not actively introduce heteroatoms such as oxygen and nitrogen into its skeletal design (few polar groups).

[0121] The curable resin composition of this embodiment is obtained by uniformly mixing the above-mentioned components in a predetermined ratio, typically pre-curing at 130-180°C for 30-500 seconds, and then post-curing at 150-250°C for 2-15 hours to achieve a sufficient curing reaction, thereby obtaining the cured product of this embodiment. Alternatively, the components of the curable resin composition may be uniformly dispersed or dissolved in a solvent, and then cured after removing the solvent.

[0122] The curable resin composition obtained in this embodiment exhibits moisture resistance, heat resistance, and high adhesion. Therefore, the curable resin composition of this embodiment can be used in a wide range of fields requiring moisture resistance, heat resistance, and high adhesion. Specifically, it is useful as an insulating material, a material for laminates (printed wiring boards, BGA substrates, multilayer substrates, etc.), a sealing material, a photoresist, and for all electrical / electronic components. Furthermore, in addition to molding materials and composite materials, it can also be used in coating materials, adhesives, 3D printing, and other fields. Especially in semiconductor packaging, reflow soldering resistance is beneficial.

[0123] The semiconductor device is an object sealed with the curable resin composition of this embodiment. Examples of semiconductor devices include DIP (Dual In-line Package), QFP (Quad Flat Package), BGA (Ball Grid Array), CSP (Chip Scale Package), SOP (Small Outline Package), TSOP (Thin Small Outline Package), and TQFP (Thin Quad Flat Package).

[0124] The preparation method of the curable resin composition of this embodiment is not particularly limited; it may simply involve uniformly mixing the components, or it may involve prepolymerization. For example, the curable resin of this embodiment may be prepolymerized by heating in the presence or absence of a catalyst, or in the presence or absence of a solvent. Similarly, in addition to the curable resin of this embodiment, curing agents such as epoxy resin, amine compounds, maleimide compounds, cyanate ester compounds, phenolic resins, and acid anhydride compounds, as well as other additives, may be added for prepolymerization. Regarding the mixing or prepolymerization of the components, extruders, kneaders, rollers, etc., may be used in the absence of solvents, while reaction vessels equipped with stirring devices may be used in the presence of solvents.

[0125] As a method for uniform mixing, the resin composition is prepared by kneading using devices such as kneaders, rollers, and planetary mixers at temperatures ranging from 50 to 100°C. The resulting resin composition can also be pulverized and molded into cylindrical sheets, granules, or powdered forms using molding machines such as tablet presses. Alternatively, these compositions can be melted onto a surface support and molded into sheets with a thickness of 0.05 mm to 10 mm to produce a cured resin composition molded body. The resulting molded body becomes non-sticky at 0–20°C and maintains almost no decrease in flowability or curability even after storage at -25°C to 0°C for more than one week.

[0126] The resulting molded body can be solidified using a transfer molding machine or a compression molding machine.

[0127] Organic solvents can also be added to the curable resin composition of this embodiment to prepare a varnish-like composition (hereinafter also simply referred to as varnish). The curable resin composition of this embodiment can be dissolved in solvents such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone to prepare a varnish. This varnish is then impregnated into substrates such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, and paper, and dried by heating. The resulting prepreg is then hot-pressed to produce a cured product of the curable resin composition of this embodiment. The solvent used in this process typically accounts for 10-70% by weight, preferably 15-70% by weight, in the mixture of the curable resin composition of this embodiment and the solvent. Alternatively, if it is a liquid composition, a cured product containing carbon fibers can be obtained directly by, for example, RTM (Resin Transfer Molding).

[0128] Alternatively, the curable composition of this embodiment can also be used as a modifier for film-type compositions. Specifically, it can be used to improve flexibility in B-stage components, etc. Such a film-type resin composition can be obtained as follows: by applying the curable resin composition of this embodiment onto a release film in the form of a varnish of the aforementioned curable resin composition, removing the solvent under heat, and then performing B-stage modification, it can be obtained in the form of a sheet adhesive. This sheet adhesive can be used as an interlayer insulating layer in multilayer substrates, etc.

[0129] The curable resin composition of this embodiment can be reduced in viscosity by heating and melting, and then impregnated with reinforcing fibers such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, and alumina fiber to obtain a prepreg. Specific examples include glass fibers such as E-glass cloth, D-glass cloth, S-glass cloth, Q-glass cloth, spherical glass cloth, NE-glass cloth, and T-glass cloth; as well as inorganic fibers other than glass, poly(p-phenylene terephthalamide) (Kevlar, a registered trademark, manufactured by DuPont), fully aromatic polyamide, polyester; and organic fibers such as poly(p-phenylenebenzoxazole), polyimide, and carbon fiber, but are not particularly limited to these. The shape of the substrate is not particularly limited; examples include woven fabric, nonwoven fabric, roving, and chopped strand mat. Furthermore, as for the weaving method, plain weave, twill weave, etc., are known, and appropriate selection and use can be made from these known weaving methods according to the target application and performance. Additionally, fabrics obtained by opening the fibers or glass fabrics treated with silane coupling agents are suitable. The thickness of the substrate is not particularly limited, but is preferably around 0.01 to 0.4 mm. Alternatively, a prepreg can be obtained by impregnating the reinforcing fibers with the aforementioned varnish and then heating and drying it.

[0130] The laminate of this embodiment includes one or more of the aforementioned prepreg. There is no particular limitation as long as the laminate includes one or more prepregs; it can have any other layers. Commonly known methods can be appropriately applied as the manufacturing method of the laminate, without particular limitation. For example, in the molding of a metal foil-coated laminate, a multi-stage press, a multi-stage vacuum press, a continuous molding machine, or an autoclave molding machine can be used. By stacking the aforementioned prepregs together and subjecting them to heating and pressure molding, a laminate can be obtained. In this case, the heating temperature is not particularly limited, but is preferably 65-300°C, more preferably 120-270°C. Furthermore, the pressure is not particularly limited. Excessive pressure makes it difficult to adjust the solid composition of the resin in the laminate, resulting in unstable quality. Conversely, insufficient pressure leads to air bubbles and poor adhesion between layers. Therefore, 2.0-5.0 MPa is preferred, more preferably 2.5-4.0 MPa. The laminate of this embodiment, by including layers formed of metal foil, can be suitably used as a metal foil-coated laminate as described later.

[0131] The prepreg is cut into the desired shape and laminated with copper foil as needed. Pressure is applied to the laminate using methods such as pressure molding, autoclave molding, and sheet winding molding, while the curable resin composition is heated and cured. This process yields laminated boards (printed wiring boards) for electrical and electronic applications and carbon fiber reinforced materials.

[0132] The cured product of this embodiment can be used for various applications such as molding materials, adhesives, composite materials, and coatings. The cured product of the curable resin composition described in this embodiment exhibits excellent heat resistance and dielectric properties, and is therefore suitable for use in composite materials for semiconductor element sealing materials, liquid crystal display element sealing materials, organic EL element sealing materials, printed wiring substrates, multilayer laminates and other electrical / electronic components, as well as lightweight high-strength structural materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics.

[0133] Example

[0134] Next, the present invention will be described in more detail through examples. Hereinafter, unless otherwise specified, parts refer to parts by weight. Furthermore, the present invention is not limited to these examples.

[0135] The following describes the various analytical methods used in the examples.

[0136] <Gel Permeation Chromatography (GPC)>

[0137] Manufacturer: Shimadzu Corporation

[0138] Columns: Protective columns SHODEX GPC KF-601 (2 columns), KF-602, KF-602.5, KF-603 (manufactured by Resonac)

[0139] Flow rate: 1.5 ml / min.

[0140] Column temperature: 40℃

[0141] Solvent used: THF (tetrahydrofuran)

[0142] Detector: RI (Differential Refraction Detector)

[0143] Gas Chromatography-Mass Spectrometry (GC-MS)

[0144] Gas Chromatography-Mass Spectrometry Analyzer: Shimadzu Corporation GCMS-QP2010

[0145] Column: HP-5 (30m)

[0146] Carrier: Helium

[0147] Flow rate: 1 mL / min

[0148] Column temperature: 80℃ (2 minutes) - 5℃ / minute - 300℃ (60 minutes)

[0149] Injection: 1 μL with an autoinjector, split ratio: 30:1, 300℃

[0150] Ionization: EI

[0151] [Example 1]

[0152] A tubular flask was filled with 1.00 part dimethyl sulfoxide, 0.20 part sodium hydroxide, 0.13 part anthrone, and 0.30 part 4-chloromethylstyrene (AGC Seimi Chemical, CMS-14). After reacting at room temperature for 2 hours, the product was analyzed by GC-MS. The presence of a peak at m / z=310 confirmed that one molecule of p-methylstyrene was added to anthrone via a dehydrochlorination reaction.

[0153] [Examples 2-12, Comparative Examples 1-3]

[0154] Except for changing the anthrone to the various raw materials and input amounts shown in Table 1, the same operation as in Example 1 was performed. The number of p-methylstyrene additions to the product is summarized in Table 1. In Table 1, "0" in "Addition 1 styrene" indicates that 1 molecule of p-methylstyrene has been added, "0" in "Addition 2 styrene" indicates that 2 molecules of p-methylstyrene have been added, and "0" in "Addition 3 styrene" indicates that 3 molecules of p-methylstyrene have been added.

[0155] [Table 1]

[0156]

[0157] Based on the results in Table 1, it was confirmed that compounds with pKa less than 31 would generate styrene compounds.

[0158] [Example 13]

[0159] While purging the flask equipped with a thermometer, cooling tube, stirrer, and Dean-Stark azeotropic distillation trap with nitrogen, 83 parts of dimethyl sulfoxide, 83 parts of toluene, and 27 parts of a 30% sodium hydroxide aqueous solution were added, and the mixture was heated to 120°C to distill off the water. After naturally cooling to 40°C, a mixture of 12 parts of acetophenone and 29 parts of 4-chloromethylstyrene (manufactured by AGCSeimi Chemical, CMS-14) was added dropwise over 30 minutes, and the reaction was continued at 40°C for 5 hours. After the reaction was completed, the mixture was diluted with 100 parts of toluene and washed with water until the pH of the effluent was neutral to remove inorganic components. The solvent was removed by distillation under heating and reduced pressure to obtain the crude product of the target compound. Then, the mixture was diluted with 5 parts of toluene and washed with 100 parts of methanol (a poor solvent) to remove the hydroxyl-containing components from the hydrolysate of 4-chloromethylstyrene. The solvent was removed again by distillation under heating and reduced pressure to obtain the target compound (ST-1) in yellow liquid form.

[0160] [Example 14]

[0161] While purging the flask equipped with a thermometer, cooling tube, stirrer, and Dean-Stark azeotropic distillation trap with nitrogen, 81 parts of dimethyl sulfoxide, 81 parts of toluene, and 27 parts of a 30% sodium hydroxide aqueous solution were added, and the mixture was heated to 120°C to distill off water. After naturally cooling to 40°C, a mixture of 10 parts of cyclohexanone and 29 parts of 4-chloromethylstyrene (manufactured by AGCSeimi Chemical, CMS-14) was added dropwise over 30 minutes, and the reaction was continued at 40°C for 5 hours. After the reaction was completed, the mixture was diluted with 100 parts of toluene and washed with water until the pH of the effluent was neutral to remove inorganic components. The solvent was removed by distillation under heating and reduced pressure to obtain the crude product of the target compound. Then, the mixture was diluted with 5 parts of toluene and washed with 100 parts of methanol (a poor solvent) to remove the hydroxyl-containing components from the hydrolysate of 4-chloromethylstyrene. The solvent was removed again by distillation under heating and reduced pressure to obtain the target compound (ST-2) in yellow liquid form.

[0162] [Example 15]

[0163] While purging the flask equipped with a thermometer, cooling pipe, and stirrer with nitrogen, 100 parts of dimethyl sulfoxide, 12 parts of indene, and 49 parts of 4-chloromethylstyrene (manufactured by AGC Seimi Chemical Co., CMS-14) were added, and the mixture was heated to 40°C with stirring. Then, 12 parts of flake sodium hydroxide were added in portions over 12 hours, and the reaction was carried out at 40°C for 4 hours, 60°C for 3 hours, and 80°C for 4 hours. After the reaction was completed, the mixture was diluted with 100 parts of toluene and washed with water until the pH of the effluent was neutral to remove inorganic components. The solvent was removed by distillation under heating and reduced pressure to obtain the crude product of the target compound. Then, the crude product was diluted with 16 parts of toluene and washed with 1000 parts of methanol (a poor solvent) to remove the hydroxyl-containing components from the hydrolysate of 4-chloromethylstyrene. The solvent was removed again by distillation under heating and reduced pressure to obtain the target compound (ST-3).

[0164] [Comparative Example 4]

[0165] While purging the flask equipped with a thermometer, cooling pipe, and stirrer with nitrogen, 200 parts of dimethyl sulfoxide, 33 parts of fluorene, and 24 parts of flake sodium hydroxide were added, and the mixture was stirred at 35°C for 30 minutes. Then, while maintaining the internal temperature below 40°C, 58 parts of 4-chloromethylstyrene (manufactured by AGC Seimi Chemical Co., CMS-14) were added dropwise over 1 hour, and the reaction was carried out at 40°C for 12 hours. 200 parts of methanol and 100 parts of water were added to induce crystallization, and the crystals were collected by filtration. The collected crystals were dissolved in 200 parts of toluene, and the organic layer was washed four times with 100 parts of water. The resulting organic layer was concentrated to obtain the target compound (ST-4).

[0166] [Examples 16-18, Comparative Examples 5-7]

[0167] The solvent solubility and storage stability of the curable resins (ST-1 to ST-4) obtained in Examples 13 to 15 and Comparative Example 4, as well as ST-5 and MI-1 described later, were verified.

[0168] (Solvent solubility)

[0169] Dilute each resin shown in Table 2 with toluene to a solids concentration of 30% and 50%, respectively, and confirm whether it dissolves. In the "Toluene Solubility" section of Table 2, mark the resin as dissolved (0) and the resin as undissolved (×).

[0170] (Maintain stability)

[0171] Dilute each resin shown in Table 2 with toluene to a solids concentration of 50% and leave at room temperature for 5 days. Confirm whether crystals precipitate 1 day and 5 days after dilution. In the "Stability of Toluene Solution" section of Table 2, mark no crystals as 0 and crystals as ×.

[0172] [Table 2]

[0173]

[0174] ST-5: OPE-2St 2200 (a polyphenylene ether compound with a styrene structure, manufactured by Mitsubishi Gas Chemical Company)

[0175] MI-1: Bis(3-ethyl-5-methyl-4-maleimidephenyl)methane (Ki Chemical Co., Ltd., BMI-70)

[0176] The results in Table 2 confirm that Comparative Examples 5 and 7, with an HSP distance greater than 2.5, exhibit poor solubility in toluene and are difficult to use with low-polarity materials. Comparative Example 4 is a polymer, therefore its HSP distance cannot be calculated.

[0177] [Examples 19-21, Comparative Examples 8-10]

[0178] A frame containing a 250μm buffer paper with a 100mm × 50mm central cutout was placed on a copper foil. 5.0g of the sample, prepared according to the proportions in Table 3, was placed in the center of the frame. Another copper foil was then placed on top of the frame and sample. The frame and sample were sandwiched between the two copper foils and shaped using a vacuum heating and pressing machine, then cured at 220°C for 2 hours. The copper foil was then etched using ferric chloride to obtain the cured film. The heat resistance and dimensional stability of the cured film were determined using methods described later.

[0179] <Heat Resistance and Dimensional Stability Testing (TMA)> Thermomechanical Analysis Apparatus: TMA Q400 (TA Instruments)

[0180] Measurement temperature range: 30~350℃

[0181] Heating rate: 2℃ / minute

[0182] Sample dimensions: Width 4mm × Length 35mm × Thickness 0.25mm

[0183] The coefficient of linear expansion was measured while the sample was heated using a thermomechanical analysis apparatus. The temperature at which the coefficient of linear expansion changed drastically was taken as the glass transition temperature (TMA Tg). The measured glass transition temperatures (TMA Tg) are shown in Table 3.

[0184] The average linear expansion rates at 60℃~90℃ (low-temperature linear expansion rate α1) and 260℃~290℃ (high-temperature linear expansion rate α2) are shown in Table 3. In addition, the dimensional changes of the sample size at 250℃ (dimensional changes from 50℃ to 250℃) are shown in Table 3, with the sample size at 50℃ as the reference.

[0185] [Table 3]

[0186]

[0187] Cat-1: 2-Ethyl-4-methylimidazolium

[0188] [Examples 22, 23, Comparative Examples 11-13]

[0189] A frame containing a 250μm buffer paper with a 100mm × 50mm central cutout was placed on a copper foil. 5.0g of the sample, prepared according to the proportions in Table 3, was placed in the center of the frame. Another copper foil was then placed on top of the frame and the sample. The frame and sample were sandwiched between the two copper foils and shaped using a vacuum heating and pressing machine, then cured at 220°C for 2 hours. The copper foil was then etched using ferric chloride to obtain the cured film. The dielectric properties of the cured film were determined using methods described later.

[0190] <Dielectric Properties Test>

[0191] Using a 10GHz cavity resonator manufactured by AET Corporation, the dielectric constant and dielectric loss tangent were determined by the cavity resonator perturbation method at 25°C. The sample dimensions were set to 1.7mm width × 100mm length × 0.25mm thickness.

[0192] [Table 4]

[0193]

[0194] The results in Tables 2-4 confirm that the curable resins of this application exhibit excellent solvent solubility and dimensional stability, and thus low dielectric properties. On the other hand, ST-4 shows problems with solvent solubility, ST-5 shows problems with dimensional stability, and MI-1 shows problems with both solvent solubility and low-temperature linear expansion (α1).

[0195] Industrial availability

[0196] The curable resin composition and cured products of the present invention are useful for various applications such as insulating materials for electrical and electronic components (such as high-reliability semiconductor sealing materials), laminates (such as printed wiring boards, BGA substrates, multilayer substrates), adhesives (such as conductive adhesives), CFRP, coatings, and 3D printing.

Claims

1. A curable resin, which is prepared by reacting a vinyl benzyl compound (A) of formula (1) with a compound (B) in a dimethyl sulfoxide solvent having a pKa less than 31, wherein the curable resin has an HSP distance of 2.5 or less from toluene. In formula (1), X represents a halogen atom, R1 represents an alkyl group with 1 to 20 carbon atoms or an aromatic group with 6 to 20 carbon atoms that may be substituted, and s is an integer from 0 to 4.

2. The curable resin according to claim 1, wherein, The compound (B) is a hydrocarbon compound and / or a carbonyl compound.

3. The curable resin according to claim 1, wherein, The compound (B) is a compound having at least one partial structure of the partial structures shown in formulas (2) to (5) below. In formula (2), Y2 represents an alkylene group, -O- group, or -C(=O)- group with 1 to 20 carbon atoms that may be substituted, and multiple R2 groups exist independently, representing an alkyl group with 1 to 20 carbon atoms or an aromatic group with 6 to 20 carbon atoms that may be substituted. R2' represents a hydrogen atom, an alkyl group with 1 to 20 carbon atoms or an aromatic group with 6 to 20 carbon atoms that may be substituted. Multiple s2 groups exist independently and are integers from 0 to 4. Dashed lines indicate that bonds may or may not exist. In formula (3), the multiple R3s exist independently, representing alkyl groups with 1 to 20 carbon atoms or aromatic groups with 6 to 20 carbon atoms that are optionally substituents. s3 is an integer from 0 to 4. The dashed line indicates that a bond may or may not exist. In formula (4), Y4 represents a directly bonded or optionally substituent alkylene group with 1 to 10 carbon atoms, and multiple R4s exist independently, representing an alkyl group with 1 to 20 carbon atoms or an aromatic group with 6 to 20 carbon atoms that may have substituents. s4 is an integer from 0 to 10. The dashed line indicates that a bond may or may not exist. In formula (5), ring A represents a 5-8 member aromatic ring, and multiple R5s exist independently, representing an alkyl group with 1-20 carbon atoms or an aromatic group with 6-20 carbon atoms that may have substituents. s51 is an integer from 0 to 3, and s52 is 0 to the maximum number of substitutions.

4. A curable resin composition comprising the curable resin of claim 1 or 2.

5. The curable resin composition according to claim 4, further comprising at least one of the following groups: maleimide resin, polyphenylene ether compound, compound having olefinic unsaturated bonds, cyanate ester resin, polybutadiene and its modified forms, polystyrene and its modified forms, polyethylene and its modified forms, benzoxazine resin, epoxy resin, reactive ester compound, phenolic resin, amine resin, isocyanate ester resin, polyamide resin, polyimide resin, and reactive ester.

6. The curable resin composition according to claim 4, further comprising a curing accelerator.

7. The curable resin composition according to claim 4, used for printed wiring substrates.

8. A varnish comprising the curable resin and organic solvent as described in claim 1 or 2.

9. A varnish comprising the curable resin composition of claim 5 and an organic solvent.

10. A cured product obtained by curing the curable resin according to claim 1 or 2.

11. A cured product obtained by curing the curable resin composition of claim 4.

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