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JP-2026075604-A - Maleimide resin, curable resin composition and its cured product

JP2026075604AJP 2026075604 AJP2026075604 AJP 2026075604AJP-2026075604-A

Abstract

[Problem] To provide a maleimide resin having excellent low dielectric loss tangent and excellent storage stability in varnish state, a curable resin composition containing the maleimide resin, and a cured product thereof. [Solution] A maleimide resin having repeating units of the following formulas (a) and (b), with an acid value of 25 or less. [Selection Diagram] None

Inventors

  • 本多 理沙
  • 長谷川 篤彦
  • 関 允諭
  • 遠島 隆行

Assignees

  • 日本化薬株式会社

Dates

Publication Date
20260508
Application Date
20251007
Priority Date
20241022

Claims (17)

  1. A maleimide resin having repeating units of the following formulas (a) and (b), with an acid value of 25 or less. (In the above formula, X is represented by the following formula (Y). Ra represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms. m is the average number of repetitions, where 1 ≤ m < 1000. n is the average number of repetitions, where 1.1 ≤ n < 1000. (a) and (b) are linked by *, and the repetition positions may be random.) (In the above formula (Y), each R1 exists independently and represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms. Each R exists independently and represents a hydrocarbon group having 1 to 10 carbon atoms. Ar represents a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocycle. a represents an integer from 0 to 4. * indicates a bond position.)
  2. The maleimide resin according to claim 1, wherein Ar is substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, or substituted or unsubstituted naphthylene.
  3. The maleimide resin according to claim 1, wherein formula (Y) is one or more of the following formulas (A) to (D). (In the above formula, R represents a hydrocarbon group having 1 to 10 carbon atoms, and a represents an integer from 0 to 4. * indicates the bond position.)
  4. This maleimide resin is obtained by reacting a styrene-based monomer maleic anhydride copolymer with a compound containing two or more amino groups in its molecule and maleic anhydride. The compound containing two or more amino groups in the molecule is one or more of the amine compounds represented by the following formula (Y'), Maleimide resin with an acid value of 25 or less. (In the above formula (Y'), each R exists independently and represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms. Each R exists independently and represents a hydrocarbon group having 1 to 10 carbon atoms. Ar represents a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocycle. a represents an integer from 0 to 4. b is the average value of the number of repeats, where 1 ≤ b < 5.)
  5. The maleimide resin according to claim 4, wherein Ar is substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, or substituted or unsubstituted naphthylene.
  6. The maleimide resin according to claim 4, wherein the amine compound represented by formula (Y') is one or more amine compounds represented by the following formulas (A') to (D'). (In the above formula, R represents a hydrocarbon group having 1 to 10 carbon atoms, a represents an integer from 0 to 4, and b is the average value of the number of repetitions, where 1 ≤ b < 5.)
  7. A curable resin composition containing the maleimide resin according to any one of claims 1 to 6.
  8. Furthermore, the curable resin composition according to claim 7, further comprising at least one selected from the group consisting of maleimide resins other than the maleimide resin, polyphenylene ether compounds, compounds having ethylenically unsaturated bonds, cyanate ester resins, polybutadiene and modified thereof, polystyrene and modified thereof, polyethylene and modified thereof, epoxy resins, active ester compounds, phenolic resins, amine resins, isocyanate resins, polyamide resins, polyimide resins, and benzoxazine compounds.
  9. Furthermore, the curable resin composition according to claim 7, further containing a curing accelerator.
  10. Furthermore, the curable resin composition according to claim 7 contains a photoradical polymerization initiator.
  11. A curable resin composition according to claim 10, for use as a resist.
  12. A curable resin composition according to claim 7, for use in printed circuit boards.
  13. A varnish comprising a maleimide resin and an organic solvent according to any one of claims 1 to 6.
  14. A varnish comprising the curable resin composition and organic solvent described in claim 7.
  15. A cured product obtained by curing the maleimide resin according to any one of claims 1 to 6.
  16. A cured product obtained by curing the curable resin composition described in claim 7.
  17. The cured product according to claim 16, wherein the dielectric loss tangent at a frequency of 10 GHz, measured at 25°C, is less than 0.0016.

Description

This invention relates to maleimide resin, a curable resin composition, and its cured product, and is suitably used in electrical and electronic components such as semiconductor encapsulants, printed circuit boards, build-up laminates, resist films, and optoelectronic substrates, as well as lightweight, high-strength materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and in 3D printing applications. In recent years, the application fields of laminates used to mount electrical and electronic components have expanded, leading to broader and more sophisticated performance requirements. While conventional semiconductor chips were primarily mounted on metal lead frames, high-performance semiconductor chips such as central processing units (CPUs) are increasingly being mounted on laminates made from polymer materials. The fifth-generation communication system, "5G," currently under accelerating development, is expected to achieve even greater capacity and higher communication speeds. 5G will utilize higher frequencies, and reducing transmission loss is crucial for achieving high-speed communication using these frequencies. This necessitates even lower dielectric properties in substrate materials. Transmission loss on printed circuit boards stems from both conductor loss and dielectric loss. As described in Non-Patent Literature 1, conductor loss is proportional to the square root of the dielectric constant and the dielectric loss tangent. Therefore, improving the dielectric loss tangent, which contributes more significantly than the dielectric constant, is effective in reducing transmission loss. Examples of low-dielectric materials include thermoplastic materials such as PTFE (polytetrafluoroethylene) and LCP (liquid crystal polymer), but they have poor moldability compared to thermosetting resins. Therefore, the development of thermosetting resins with superior low-dielectric properties is desired. In light of this situation, maleimide resins, which exhibit excellent heat resistance and low dielectric properties, have recently been considered as printed circuit board materials for high-frequency applications. However, as pointed out in Patent Document 1 below, bismaleimide compounds, which have an imide structure in their molecules, are highly crystalline and have a high melting point of around 150°C, close to the 170-180°C threshold for the onset of self-reaction. Therefore, they are difficult materials to prepare by preparing impregnation varnishes, impregnating and drying them, or by melt-mixing them with epoxy resins, curing agents, fillers, etc., to produce molding materials. Japanese Patent Publication No. 2018-12671Patent No. 7208705 The GPC chart for Example 1 is shown.The GPC chart for Example 2 is shown.The GPC chart for Example 3 is shown.The GPC chart for Example 4 is shown.The GPC chart for Example 5 is shown.The GPC chart for comparative synthesis example 1 is shown. The embodiments of the present invention (hereinafter also referred to as "this embodiment") will be described in further detail below. The maleimide resin of this embodiment has repeating units of the following formulas (a) and (b). In the above formula, X is represented by the following formula (Y). Ra represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom. (a) and (b) are bonded by *, and the repeating positions may be random. m is the average value of the number of repeats, preferably 1 ≤ m < 1000, more preferably 1 < m < 1000, more preferably 2 ≤ m ≤ 750, and particularly preferably 3 ≤ m ≤ 500. n is the average value of the number of repeats, preferably 1.1 ≤ n < 1000, more preferably 1.1 < n < 1000, more preferably 1.1 < n ≤ 500, even more preferably 1.1 < n ≤ 100, and particularly preferably 1.1 < n ≤ 20. The values of m and n are derived from the styrene monomer-maleic anhydride copolymer used as raw material, and the values of m and n can be determined from the ratio of styrene monomer and acid anhydride and the molecular weight, which are determined from the acid value in the styrene monomer-maleic anhydride copolymer. In the above formula (Y), R1 is present independently and is either a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or a hydrocarbon group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group. R is present independently and represents a hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrocarbon group having 1 to 5 carbon atoms, and more preferably a hydrocarbon group having 1 to 3 carbon atoms. Hydrocarbons with 10 or fewer carbon atoms in R are less prone to molecular vibration when exposed to high frequencies and therefore have excellent electrical properties. Ar represents a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocycle, a