Low dielectric loss thermosetting resin composition

Abstract

The present disclosure relates to a low dielectric loss thermosetting resin composition comprising a copolymer containing monomer units of Formula I and aliphatic unsaturated imide monomer units of Formula II, and at least one curing agent containing maleimide, (meth)acrylic acid, or vinyl groups. Formula I, where R1 represents hydrogen or an aliphatic group, R2 represents hydrogen, an aliphatic group, or an aromatic group, and Formula II, where R3 represents H or an alkyl group, R4 represents an alkylidene group, and R5 represents an alkanediyl group. The curing agent containing maleimide, (meth)acrylic acid, or vinyl groups is preferably multifunctional. The resin composition may optionally contain a radical initiator. The resin composition may further contain an additive selected from a flame retardant, a filler, and a coupling agent. The present disclosure also relates to a prepreg or copper-clad laminate containing the thermosetting resin composition. JPEG2025531108000053.jpg62170

Description

[Technical Field]

[0001] Related Applications This application claims the benefit of European Application No. 22194425.9, filed September 7, 2022, the entire disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to polymers of thermosetting resin compositions that are useful in the chemical industry, such as in the manufacture of products such as printed circuit boards. In particular, this disclosure relates to novel compositions and processes for preparing certain low dielectric loss thermosetting resin polymers. [Background technology]

[0003] The present disclosure relates to a low dielectric loss thermosetting resin composition comprising a copolymer containing vinyl or vinyl derivative, aliphatic unsaturated imide monomer units, and a curing agent. The present disclosure further relates to a prepreg and a metal-clad laminate comprising the thermosetting resin composition. The present disclosure also relates to a printed circuit board comprising the prepreg and / or the metal-clad laminate.

[0004] Thermosetting resin compositions are known in the art. Thermosetting resins undergo a curing or crosslinking process that crosslinks polymer chains, thus bonding the entire matrix together in a three-dimensional network. Once crosslinked, thermosetting resins cannot be melted or modified (reformed). Due to their three-dimensional crosslinked structure, thermosetting resins tend to have high dimensional stability, high temperature resistance, and good resistance to solvents (U.S. Congressional Office of Technology Assessment, June 1988).

[0005] Crosslinked thermosetting resin compositions, such as epoxy resins, phenolic resins, bismaleimide resins, polyamine formaldehyde resins, and silicone resins, are useful in electrical applications and electronic devices, such as printed circuit boards (PCBs). Thermosetting resins are required to provide long life and highly reliable electrical insulation properties. Such compositions are used, for example, as fiber-reinforced prepregs and in metal-clad laminates, such as copper-clad laminates (CCLs), suitable for printed circuit boards (PCBs).

[0006] CCL serves as the main, essentially raw material contributing material for PCB fabrication, and performs four functions, including conductivity, insulation, support, and signal transmission, which determine the performance, quality, fabrication level, fabrication cost, and long-term reliability of PCB. The continuous development of PCB and the increasing application demands of electronic products gradually drive new technical requirements for CCL, simultaneously providing the driving force for the technological development of CCL and the advancement of fabrication technology.

[0007] Epoxy resins are commonly used for CCL. Curing agents for epoxy resins include, for example, phenolic, poly(styrene-co-maleic anhydride) (SMA), benzoxazine, active ester, and cyanate ester. However, epoxy resin formulations cannot meet the increasing demand for lower dielectric loss. This is mainly due to the polar groups formed during the curing of epoxy resins, which adversely affect the dielectric loss.

[0008] U.S. Patent No. 9,245,667 discloses unsaturated thermosetting compositions that achieve better dielectric properties. In many cases, unsaturated, difunctional, low-molecular-weight poly(phenylene ether)s (PPEs) are used with additional curing agents, such as triallyl isocyanurate (TAIC), bismaleimide (BMI), polybutadiene, and polybutadiene-co-styrene. The disadvantages of these low-molecular-weight PPE resins are that the PPEs may have flow problems during the curing stage and may not have good wettability to glass cloth.

[0009] Fluorine-containing resins such as PTFE can also be used for PCBs and exhibit low dielectric loss, however, they are expensive and not easy to process, thus limiting their use.

[0010] Japanese Patent Publication No. 58-019316 discloses a thermosetting resin composition that provides improved heat resistance and, therefore, improved insulating properties. The thermosetting resin composition is produced by mixing a styrene copolymer having a specific imide bond with a radical polymerization catalyst. The styrene copolymer preferably comprises styrene together with maleic anhydride, which undergoes an imidization reaction with, for example, allylamine. The resulting copolymer is heated in the presence of a known radical polymerization catalyst, such as an organic peroxide, to obtain a heat-resistant thermosetting resin. A disadvantage of this cured thermosetting resin is that it still has a relatively high dielectric loss, reportedly up to 1 MHz. As the frequency increases, the dielectric loss increases, while higher frequencies, e.g., 1 GHz or higher, are typically used for high-speed PCB applications. Furthermore, the cured resin exhibits a relatively low decomposition temperature, i.e., low thermal stability. Thermal stability can affect processability and operating temperature (service temperature). For example, poor thermal stability can cause short delamination times during the soldering process for PCB applications, leading to thermal reliability and signal integrity issues during use.

[0011] Therefore, thermosets used in high-speed applications must meet several critical thermal, environmental, and electrical requirements to meet the performance criteria required for microelectronic applications. These desired attributes include thermal stability, low moisture absorption, copper adhesion, high breakdown voltage (low leakage current), low dielectric constant (Dk), and low dielectric loss (Df) (also known as loss tangent).

[0012] Therefore, there is a need to develop thermosetting resin compositions that have excellent dielectric properties, such as low dielectric constant (Dk) and low dielectric loss (Df), in combination with other properties required in high-speed PCBs, such as high Tg, low coefficient of thermal expansion, low water absorption, and high peel strength. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] U.S. Patent No. 9,245,667 [Patent Document 2] Japanese Patent Publication No. 58-019316 [Patent Document 3] U.S. Patent No. 4,795,692 Summary of the Invention [Problem to be solved by the invention]

[0014] It is an object of the present disclosure to provide thermosetting resin compositions that have improved dielectric and thermal properties and can be used in electronic applications such as high speed PCBs. Improved dielectric properties mean lower dielectric loss and a lower dielectric constant (Dk) or dielectric constant combined with better thermal stability. [Means for solving the problem]

[0015] In one aspect, the present disclosure provides a compound of formula I: [ka] [wherein R1 represents hydrogen or an aliphatic group, and R2 represents hydrogen, an aliphatic group, or an aromatic group] and monomer units of formula II: [ka] wherein R3 is H or an alkyl group, R4 is an alkylidene group, and R5 is an alkanediyl group. a copolymer containing an aliphatic unsaturated imide of the formula: At least one curing agent containing a maleimide, (meth)acrylate, or vinyl group and a thermosetting resin composition comprising:

[0016] In another aspect, the present disclosure provides a thermoset resin composition prepared by a process comprising the steps of: (i) contacting a styrene-maleic anhydride copolymer (SMA) with an unsaturated aliphatic amine to prepare a styrene-maleimide copolymer; and / or (ii) crosslinking the styrene-maleimide copolymer with at least one curing agent.

[0017] In another aspect, the present disclosure provides a thermoset resin composition comprising a styrene-maleimide copolymer crosslinked by at least one curing agent.

[0018] In another aspect, the present disclosure provides a prepreg comprising the thermosetting or thermoset resin composition described herein, or a semi-cured product of the thermosetting or thermoset resin composition described herein; and a substrate.

[0019] In another aspect, the present disclosure provides a metal-clad laminate comprising an insulating layer formed from a cured product of a prepreg composition described herein or a thermoset resin composition described herein, and at least one metal layer formed on one or both surfaces of the insulating layer.

[0020] In another aspect, the present disclosure provides a printed circuit board comprising a prepreg composition described herein, or a thermoset resin composition described herein, or a metal-clad laminate described herein.

[0021] Additional embodiments, features, and advantages of the present disclosure will become apparent from the following detailed description and through practice of the disclosure. The compounds of the present disclosure can be described as embodiments in any of the following listed clauses. It will be understood that any of the embodiments described herein can be used in conjunction with any other embodiment described herein to the extent that the embodiments are not mutually exclusive.

[0022] 1. Formula I below: [ka] [wherein R1 represents hydrogen or an aliphatic group, and R2 represents hydrogen, an aliphatic group, or an aromatic group] and monomer units of formula II: [ka] wherein R3 is H or an alkyl group, R4 is an alkylidene group, and R5 is an alkanediyl group. and at least one curing agent containing a maleimide, (meth)acrylate, or vinyl group.

[0023] 2. The thermosetting resin composition according to clause 1, wherein the maleimide curing agent is a polyfunctional maleimide.

[0024] 3. The thermosetting resin composition according to clause 2, wherein the polyfunctional maleimide is selected from the group consisting of bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, biphenyl-containing maleimide, meta-arylene-containing maleimide, or 1,6-bismaleimide-(2,2,4-trimethyl)hexane.

[0025] 4. The thermosetting resin composition according to any one of clauses 1 to 2, wherein the curing agent containing a (meth)acrylate group is a polyfunctional (meth)acrylate.

[0026] 5. The polyfunctional (meth)acrylic acid is represented by the following formula XI: [ka] [n is an integer between 1 and 20] 5. The thermosetting resin composition according to claim 4, represented by:

[0027] 6. The thermosetting resin composition of any one of clauses 1 to 2, wherein the curing agent containing a vinyl group is a multifunctional vinyl-containing curing agent.

[0028] 7. The thermosetting resin composition of clause 6, wherein the multifunctional vinyl curing agent is selected from the group consisting of polybutadiene, polybutadiene-co-styrene, divinylbenzene, bis-vinylphenylethane, a multifunctional vinyl aromatic copolymer, a vinyl cyclic olefin resin, or a poly(arylene ether).

[0029] 8. The poly(arylene ether) has Formula XII: [ka] [n is an integer between 1 and 20] 8. The thermosetting resin composition according to claim 7, represented by:

[0030] 9. The thermosetting resin composition of any one of clauses 1 to 8, further comprising a radical initiator.

[0031] 10. The thermosetting resin composition of clause 1, wherein the molar ratio of monomer units of formula I to unsaturated imide monomer units of formula II is in the range of 1:1 to 9:1.

[0032] 11. The copolymer has the following formula III: [ka] wherein R6 is selected from a saturated aliphatic group or an aromatic group. Item 10. The thermosetting resin composition of item 1, further comprising a saturated imide monomer unit of

[0033] 12. The thermosetting resin composition of clause 11, wherein the molar ratio of unsaturated imide monomer units of formula II to saturated imide monomer units of formula III is in the range of 1:0 to 1:2.

[0034] 13. The thermosetting resin composition of any one of clauses 1 to 12, further comprising at least one additive selected from a flame retardant, a filler, a coupling agent, and any combination thereof.

[0035] 14. A prepreg comprising the thermosetting resin composition or a semi-cured product of the resin composition according to any one of clauses 1 to 13 and a substrate.

[0036] 15. A metal-clad laminate comprising an insulating layer formed from a cured product of the prepreg according to clause 14, and at least one metal layer formed on one or both surfaces of the insulating layer.

[0037] 16. A printed circuit board comprising the metal clad laminate of clause 15.

[0038] 17. (ii) A thermoset resin composition prepared by a process comprising crosslinking a styrene-maleimide copolymer with at least one curing agent.

[0039] 18. (i) contacting a styrene-maleic anhydride copolymer (SMA) with an unsaturated aliphatic amine to prepare a styrene-maleimide copolymer. 18. The thermosetting resin composition of claim 17, further comprising:

[0040] 19. The styrene-maleimide copolymer has the following formula I: [ka] wherein R1 is hydrogen or an aliphatic group, and R2 is hydrogen, an aliphatic group, or an aromatic group; and Formula II below: [ka] wherein R3 is H or an aliphatic group, R4 is an alkylidene group, and R5 is an alkylene group. Aliphatic unsaturated imides 19. The thermosetting resin composition of claim 17 or 18, comprising:

[0041] 20. The styrene-maleimide copolymer has the following formula III: [ka] wherein R6 is a saturated aliphatic or aromatic group. 20. The thermoset resin composition of any one of clauses 17 to 19, further comprising a saturated imide monomer of

[0042] 21. The thermosetting resin composition of any one of clauses 17 to 20, wherein at least one curing agent comprises one or more maleimide groups, (meth)acrylate groups, and / or vinyl groups.

[0043] 22. The thermosetting resin composition of any one of clauses 17 to 20, wherein at least one curing agent comprises a multifunctional maleimide.

[0044] 23. The thermosetting resin composition of clause 22, wherein the polyfunctional maleimide is selected from bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, biphenyl-containing maleimides, meta-arylene-containing maleimides, and 1,6-bismaleimido-(2,2,4-trimethyl)hexane.

[0045] 24. The thermosetting resin composition of any one of clauses 17 to 20, wherein at least one curing agent is a multifunctional (meth)acrylate.

[0046] 25. A polyfunctional (meth)acrylic acid having the formula XI: [ka] [wherein n is an integer of 1 to 20] 25. The thermosetting resin composition of claim 24,

[0047] 26. The thermosetting resin composition of any one of clauses 17 to 20, wherein at least one curing agent is a multifunctional vinyl-containing curing agent.

[0048] 27. The thermosetting resin composition of clause 26, wherein the multifunctional vinyl-containing curing agent is selected from polybutadiene, polybutadiene-co-styrene, divinylbenzene, bis-vinylphenylethane, multifunctional vinyl aromatic copolymers, vinyl cyclic olefin resins, and poly(arylene ethers).

[0049] 28. The poly(arylene ether) has Formula XII: [ka] [wherein n is an integer of 1 to 20] 28. The thermosetting resin composition of claim 27,

[0050] 29. The thermosetting resin composition of any one of clauses 17 to 28, wherein step (ii) is carried out in the presence of one or more radical polymerization initiators.

[0051] 30. The thermosetting resin composition of clause 29, wherein the one or more radical polymerization initiators comprise an azo compound or an organic peroxide.

[0052] 31. The thermosetting resin composition according to clause 30, wherein the azo compound is azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4,4-trimethylpentane), or 2,2'-azobis(N-butyl-2-methylpropionamide).

[0053] 32. The thermosetting resin composition of clause 30, wherein the organic peroxide is selected from the group consisting of benzoyl peroxide, t-butyl hydroperoxide, dicumyl peroxide, t-butyl perbenzoate, methyl ethyl ketone peroxide, cyclohexanone peroxide, acetyl peroxide, di-t-butyl peroxide, t-butyl perbenzoate, di(2-tert-butylperoxy-isopropyl)benzene, 2,5-dimethyl-2,5-di(tertbutylperoxy)hexyne-3), and cumene hydroperoxide.

[0054] 33. The thermosetting resin composition of any one of clauses 18 to 32, wherein the molar ratio of monomer units of formula I to unsaturated imide monomer units of formula II in the styrene-maleimide copolymer is from about 1:1 to 9:1.

[0055] 34. The thermosetting resin composition of any one of clauses 19 to 33, wherein the molar ratio of unsaturated imide monomer units of formula II to saturated imide monomer units of formula III is from about 1:0 to 1:2.

[0056] 35. The thermosetting resin composition of any one of clauses 17 to 34, wherein step (ii) is carried out in the presence of at least one additive selected from the group consisting of flame retardants, fillers, coupling agents, and combinations thereof.

[0057] 36. The thermosetting resin composition of any one of clauses 17 to 35, wherein step (ii) is carried out using heat.

[0058] 37. The thermosetting resin composition of any one of clauses 17 to 36, wherein step (ii) is carried out in the presence of a substrate.

[0059] 38. The thermoset resin composition of clause 37, wherein step (ii) is carried out using heating that does not result in complete curing of the thermoset resin composition, the incomplete curing resulting in a prepreg composition of the thermoset resin composition.

[0060] 39. A metal clad laminate comprising the thermoset resin composition of clause 38 prepared by a process comprising, prior to completing step (ii), contacting the thermoset resin composition with one or more metal layers.

[0061] 40.i.) an insulating layer comprising a thermosetting resin as described in clause 37; ii.) one or more metal layers on one or both surfaces of the insulating layer; 40. The metal clad laminate of claim 39, comprising:

[0062] 41. A printed circuit board comprising a prepreg according to clause 38 or a metal clad laminate according to clause 40.

[0063] 42. A thermoset resin composition comprising a styrene-maleimide copolymer crosslinked by at least one curing agent.

[0064] 43. A styrene-maleimide copolymer having the following formula I: [ka] wherein R1 is hydrogen or an aliphatic group, and R2 is hydrogen, an aliphatic group, or an aromatic group; and Formula II below: [ka] wherein R3 is H or an aliphatic group, R4 is an alkylidene group, and R5 is an alkylene group. 43. The thermosetting resin composition of claim 42, comprising an aliphatic unsaturated imide of

[0065] 44. A styrene-maleimide copolymer having the following formula III: [ka] wherein R6 is a saturated aliphatic or aromatic group. 44. The thermosetting resin composition of claim 42 or 43, further comprising a saturated imide monomer of the formula:

[0066] 45. The thermosetting resin composition of any one of clauses 42 to 44, wherein at least one curing agent comprises one or more maleimide groups, (meth)acrylate groups, and / or vinyl groups.

[0067] 46. ​​The thermosetting resin composition of any one of clauses 42 to 44, wherein at least one curing agent comprises a multifunctional maleimide.

[0068] 47. The thermosetting resin composition of clause 46, wherein the polyfunctional maleimide is selected from bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, biphenyl-containing maleimides, meta-arylene-containing maleimides, and 1,6-bismaleimido-(2,2,4-trimethyl)hexane.

[0069] 48. The thermosetting resin composition of any one of clauses 42 to 44, wherein at least one curing agent is a multifunctional (meth)acrylate.

[0070] 49. A polyfunctional (meth)acrylic acid having the following formula XI: [ka] [wherein n is an integer of 1 to 20] 49. The thermosetting resin composition of claim 48,

[0071] 50. The thermoset resin composition of any one of clauses 42 to 44, wherein at least one curing agent is a multifunctional vinyl-containing curing agent.

[0072] 51. The thermosetting resin composition of clause 50, wherein the multifunctional vinyl-containing curing agent is selected from polybutadiene, polybutadiene-co-styrene, divinylbenzene, bis-vinylphenylethane, multifunctional vinyl aromatic copolymers, vinyl cyclic olefin resins, and poly(arylene ethers).

[0073] 52. The poly(arylene ether) has Formula XII: [ka] [wherein n is an integer of 1 to 20] 52. The thermosetting resin composition of claim 51,

[0074] 53. The thermosetting resin composition of any one of clauses 42 to 52, wherein the styrene-maleimide copolymer is crosslinked by at least one curing agent in the presence of one or more radical polymerization initiators.

[0075] 54. The thermosetting resin composition according to clause 53, wherein the radical polymerization initiator comprises an azo compound or an organic peroxide.

[0076] 55. The thermosetting resin composition according to clause 54, wherein the azo compound is azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4,4-trimethylpentane), or 2,2'-azobis(N-butyl-2-methylpropionamide).

[0077] 56. The thermosetting resin composition of clause 55, wherein the organic peroxide is selected from the group consisting of benzoyl peroxide, t-butyl hydroperoxide, dicumyl peroxide, t-butyl perbenzoate, methyl ethyl ketone peroxide, cyclohexanone peroxide, acetyl peroxide, di-t-butyl peroxide, t-butyl perbenzoate, di(2-tertbutylperoxy-isopropyl)benzene, 2,5-dimethyl-2,5-di(tertbutylperoxy)hexyne-3), and cumene hydroperoxide.

[0078] 57. The thermosetting resin composition of any one of clauses 42 to 56, wherein the styrene-maleimide copolymer is crosslinked with at least one curing agent using heat.

[0079] 58. The thermosetting resin composition of any one of clauses 42 to 57, wherein the molar ratio of monomer units of formula I to unsaturated imide monomer units of formula II in the styrene-maleimide copolymer is from about 1:1 to 9:1.

[0080] 59. The thermosetting resin composition of clause 58, wherein the molar ratio of unsaturated imide monomer units of formula II to saturated imide monomer units of formula III is about 1:0 to 1:2.

[0081] 60. The thermosetting resin composition of any one of clauses 42 to 59, further comprising at least one additive selected from the group consisting of flame retardants, fillers, coupling agents, and combinations thereof.

[0082] 61. The thermosetting resin composition of any one of clauses 42 to 60, further comprising a substrate.

[0083] 62. The thermoset resin composition of clause 61, wherein the styrene-maleimide copolymer is not fully crosslinked by the at least one curing agent to provide a prepreg composition of the thermoset resin composition.

[0084] 63. A metal clad laminate comprising the thermoset resin composition of clause 61 or 62, the metal clad laminate comprising one or more metal layers on the thermoset resin composition.

[0085] 64.i.) an insulating layer comprising a thermosetting resin as described in clause 61; ii.) one or more metal layers on one or both surfaces of the insulating layer; 64. The metal clad laminate of claim 63, comprising:

[0086] 65. A printed circuit board comprising the thermosetting resin composition of clause 62 or the metal clad laminate of clause 63 or 64. [Brief explanation of the drawings]

[0087] [Figure 1] FIG. 1 is a graph of the TGA curves for Example 3 and Comparative Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0088] Before the present disclosure is further described, it is to be understood that this disclosure is not limited to particular embodiments described, which may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present disclosure, in that the scope of the present disclosure will be limited only by the appended claims.

[0089] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. All patents, applications, published applications, and other publications mentioned herein are incorporated by reference in their entirety. In the event that a definition set forth in this section is opposite or inconsistent with a definition set forth in a patent, application, or other publication incorporated by reference herein, the definition set forth in this section shall control over the definition incorporated by reference herein.

[0090] As used in this specification and the appended claims, singular words (including words followed by "a," "an," and "the" in the foreign language specification of this application) include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. Accordingly, this statement is intended to serve as a guideline precedent regarding the use of exclusive terminology, such as "solely," "only," and the like, or the use of a "negative" limitation in connection with reciting claim elements.

[0091] As used herein, the terms "including," "containing," and "comprising" are used in their open, non-limiting sense.

[0092] In order to provide a more concise explanation, some of the quantitative expressions given herein are not modified with the term "about". Regardless of whether the term "about" is explicitly used, any quantity given herein is meant to refer to the actual given value, and it is also meant to refer to an approximate value for the given value that is reasonably inferred based on ordinary skill in the art, and it is understood that the approximate value includes equivalent amounts and approximate values ​​resulting from the conditions of experiment and / or measurement for such given value. Whenever a yield is given as a percentage, such a yield refers to the mass of an entity, and the yield is given relative to the maximum amount of the same entity that can be obtained under specific stoichiometric conditions. Unless otherwise indicated, concentrations given as percentages refer to mass ratios.

[0093] As used herein, the term "aliphatic" includes hydrocarbon compositions that may be saturated or unsaturated. Aliphatic compositions are not aromatic and do not have alternating double bonds, e.g., π-electron conjugation. Aliphatic compositions can include linear, branched, or cyclic hydrocarbons. Cycloaliphatic compositions are not aromatic.

[0094] As used herein, the term "alkyl" refers to a monovalent saturated aliphatic chain of carbon atoms, which is optionally branched and contains from 1 to 20 carbon atoms. In certain embodiments, alkyl is advantageously C1-C 12 , C1~C 10It should be further understood that alkyl groups may be of limited length, including, for example, C1-C8, C1-C7, C1-C6, and C1-C4, and that such particularly limited length alkyl groups are sometimes referred to as "lower alkyls." Exemplary alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, 2-pentyl, 3-pentyl, neopentyl, hexyl, heptyl, octyl, and the like. Alkyl may be substituted or unsubstituted. Exemplary substituents include cycloalkyl, aryl, heteroaryl, heteroalicyclic, hydroxy, alkoxy, aryloxy, mercapto, alkylthio, arylthio, cyano, halo, carbonyl, oxo, (═O), thiocarbonyl, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, nitro, and amino, or as described in the various embodiments provided herein.

[0095] As used herein, the terms "alkylene" and "alkanediyl" refer to a divalent saturated aliphatic chain of carbon atoms, which may be optionally branched, containing from 1 to 20 carbon atoms. In certain embodiments, alkylene or alkanediyl advantageously has a C1-C 12 , C1~C 10It should be further understood that the alkyl group may be of limited length, including, by way of example, C1-C8, C1-C7, C1-C6, and C1-C4, and that such particularly limited length alkyl groups, including, by way of example, C1-C8, C1-C7, C1-C6, and C1-C4, etc., are sometimes referred to as "lower alkylene" or "lower alkanediyl." Exemplary alkylene or alkanediyl groups include, but are not limited to, methylene (methane-diyl), ethylene (ethane-1,2-diyl), n-propylene (propane-1,3-diyl), isopropylene (propane-1,2-diyl), n-butylene (butane-1,4-diyl), sec-butylene (butane-1,3-diyl), n-pentylene (pentane-1,5-diyl), 2-pentylene (pentane-1,4-diyl), 3-pentylene (pentane-1,3-diyl), n-hexylene (hexane-1,6-diyl), n-heptylene (heptane-1,7-diyl), and octylene (octane-1,8-diyl), etc. The alkylene or alkanediyl can be substituted or unsubstituted. Exemplary substituents include cycloalkyl, aryl, heteroaryl, heteroalicyclic, hydroxy, alkoxy, aryloxy, mercapto, alkylthio, arylthio, cyano, halo, carbonyl, oxo, (═O), thiocarbonyl, O-carbamyl, N-carbamyl, O-thiocarbamyl, N-thiocarbamyl, C-amido, N-amido, C-carboxy, O-carboxy, nitro, and amino, or as described in the various embodiments provided herein.

[0096] As used herein, the term "cycloalkyl" includes an aliphatic ring of carbon atoms, which may be optionally branched, containing from 3 to 20 carbon atoms. In certain embodiments, cycloalkyl advantageously includes C3-C6 10 It should be further understood that the cycloalkyl group may be of a limited length, including, but not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and the like.

[0097] As used herein, the terms "alkenyl" and "alkynyl" refer to an unsaturated aliphatic chain of carbon atoms. As used herein, the term "alkenyl" includes a chain of carbon atoms, which may be optionally branched, containing from 2 to 20 carbon atoms and containing at least one carbon-carbon double bond (i.e., C=C). In certain embodiments, alkenyl advantageously includes C2 to C6. 12 It will be understood that the alkyl groups may be of limited length, including C2-C9, C2-C8, C2-C7, C2-C6, and C2-C4. Exemplary alkenyl groups include, but are not limited to, vinyl, allyl, ethenyl, 1-propenyl, 2-propenyl, and 1-, 2-, or 3-butenyl, and the like. As used herein, the term "alkynyl" includes a chain of carbon atoms, which may be optionally branched, containing from 2 to 20 carbon atoms, and containing at least one carbon-carbon triple bond (i.e., C≡C). In certain embodiments, alkynyl groups each advantageously include C2-C 12 It will be understood that the alkynyl group may be of limited length, including C2-C9, C2-C8, C2-C7, C2-C6, and C2-C4, and exemplary alkynyl groups include, but are not limited to, ethynyl, 1-propynyl, 2-propynyl, and 1-, 2-, or 3-butynyl, etc.

[0098] As used herein, the term "alkylidene" refers to a divalent functional group derived from an alkane by removing two hydrogen atoms from the same carbon atom, where the free valence is part of a double bond -RC= and the carbon atom is sp 2 It is a hybrid. sp 2 The carbon atom can be at any carbon position in the chain. Exemplary alkylidene groups include, but are not limited to, methylidene, ethylidene, 1-propylidene, 2-propylidene, and the like.

[0099] As used herein, the term "aryl" refers to an all-carbon monocyclic or fused-ring polycyclic group of 6 to 12 carbon atoms having a completely conjugated π-electron system, e.g., "aromatic." In certain embodiments, aryl advantageously refers to a C6-C 10 It will be understood that the aryl group may be of limited size, such as aryl. Exemplary aryl groups include, but are not limited to, phenyl, naphthyl, and anthracenyl. As described herein, aryl groups may be unsubstituted or substituted.

[0100] The term "substituted" means that the specified group or moiety has one or more substituents. The term "unsubstituted" means that the specified group has no substituents. When the term "substituted" is used to describe a structural system, substitution occurs at any valence-accepting position on that system. In some embodiments, "substituted" means that the specified group or moiety has one, two, or three substituents. In other embodiments, "substituted" means that the specified group or moiety has one or two substituents. In still other embodiments, "substituted" means that the specified group or moiety has one substituent. Exemplary substituents include alkyl, cycloalkyl, aryl, hydroxy, alkoxy, aryloxy, mercapto, alkylthio, arylthio, cyano, halo, carbonyl, oxo, (═O), thiocarbonyl, nitro, and amino, or those described in the various embodiments provided herein.

[0101] One object of the present disclosure is achieved in that there is provided a thermosetting resin composition comprising a copolymer comprising monomer units of Formula I and an aliphatic unsaturated imide of Formula II, and at least one curing agent comprising a maleimide, a (meth)acrylic acid, or a vinyl group.

[0102] [ka] wherein R1 represents hydrogen or an aliphatic group, and R2 represents hydrogen, an aliphatic group, or an aromatic group; preferably, R1 is methyl or H, and R2 is H.

[0103] [ka] In the formula, R3 is H or an alkyl group, R4 is an alkyl group, and R5 is an alkyl group. Preferably, R3 is H or a C1-C8 alkyl group, R4 is a C1-C4 alkylidene group, and R5 is a C1-C4 alkanediyl group. More preferably, R3 is H, R4 is CH2, and R5 is CH2.

[0104] Surprisingly, it has been discovered that the thermosetting resin composition of the present disclosure has low dielectric loss (Df) at high frequencies such as 5 GHz. Furthermore, the thermosetting resin composition of the present disclosure exhibits improved thermal stability. Low dielectric loss according to the present disclosure means a dielectric constant (Dk) of less than 2.7, preferably less than 2.6, and a dielectric loss (Df) of less than 0.0040, preferably less than 0.0030, and more preferably less than 0.0020, at high frequencies, for example, above 5 GHz.

[0105] Improved thermal stability according to the present disclosure means that the cured resin system has a high thermal decomposition temperature, such as a thermal decomposition temperature, of greater than 350°C, at which the mass of a cured sample is 5.0% less than its mass as measured by thermogravimetric analysis (TGA) at 50°C, i.e., Td5%.

[0106] The glass transition temperature (T g ) is at least greater than 110° C., preferably greater than 150° C., and more preferably greater than 170° C. The Tg of the cured resin composition can be measured by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), or thermomechanical analysis (TMA).

[0107] The molar ratio of the monomer units of formula I to the aliphatic unsaturated imide monomer units of formula II is between 1:1 and 9:1. Preferably, the molar ratio is between 3:1 and 8:1.

[0108] The weight average molecular weight (g / mol) of the copolymer may range from 4,000 to 80,000, preferably from 4,500 to 30,000, more preferably from 7,000 to 20,000.

[0109] As used herein, "polymer" means a substance or material made up of many repeating subunits, or "monomers." As used herein, "copolymer" means a polymer made up of more than one type of monomer.

[0110] In the thermosetting resin composition of the present disclosure, the copolymer of the monomer unit of Formula I and the aliphatically unsaturated imide monomer unit of Formula II may optionally be combined with a saturated imide monomer unit of Formula III. The incorporation of the saturated imide monomer unit of Formula III can alter the thermal and dielectric properties of the copolymer depending on the selection of R6.

[0111] [ka] wherein R6 is selected from saturated aliphatic or aromatic groups, and preferably R6 is selected from methyl, ethyl, propyl, cyclohexyl, benzyl, phenyl, substituted phenyl, or naphthyl.

[0112] The molar ratio of the monomer units of Formula I to the combination of the aliphatic unsaturated imide monomer units of Formula II and the saturated imide monomer units of Formula III is in the range of 1:1 to 9:1. Preferably, the molar ratio is in the range of 3:1 to 8:1. The molar ratio of the aliphatic unsaturated imide monomer units of Formula II to the saturated imide monomer units of Formula III is in the range of 1:0 to 1:2.

[0113] Preferably, the thermosetting resin composition according to the present disclosure comprises a copolymer according to Formula IV or V below:

[0114] [ka] In the formula, the molar ratio of n:m is in the range of 1:1 to 9:1.

[0115] [ka] In the formula, the molar ratio of n:(m+p) is in the range of 1:1 to 9:1, and m:p is in the range of 1:0 to 1:2.

[0116] The synthesis of the copolymers described is not particularly limited. For example, aliphatic unsaturated maleimides such as N-allylmaleimide can be copolymerized with, for example, styrene, as disclosed in U.S. Pat. No. 4,795,692. Alternatively, a copolymer containing a monomer unit of Formula I and an anhydride monomer unit of Formula VI can be imidized with an unsaturated aliphatic amine of the formula: [ka]

[0117] Examples of unsaturated aliphatic amines include, but are not limited to, allylamine, methallylamine, and butenylamine. Optionally, saturated aliphatic or aromatic amines may be used in combination with the unsaturated amines. The imidization process is well known to those skilled in the art and is not particularly limited. It can be carried out at atmospheric or elevated pressure, in a solvent, in water, or in the melt. Optionally, a catalyst, such as a tertiary amine such as triethylamine, may be added to accelerate the imidization reaction. Preferably, styrene-maleic anhydride copolymer (SMA) is imidized with allylamine. The weight-average molecular weight (g / mol) of the SMA copolymer may range from 4,000 to 80,000, preferably from 4,500 to 30,000, and more preferably from 7,000 to 20,000, and the molar ratio of styrene to MA ranges from 1:1 to 9:1, preferably from 3:1 to 8:1.

[0118] The method for purifying the imidized polymer is not particularly limited and may consist of one or more of the following methods: distillation of the reaction solvent, precipitation, filtration, washing, and drying.

[0119] The thermosetting resin composition of the present disclosure includes at least one curing agent that includes a maleimide, (meth)acrylate, or vinyl group.

[0120] As used herein, "crosslinked" refers to a covalent bond between polymer chains, either directly or through one or more "curing agents" as described herein. As used herein, a "curing agent" refers to a compound having one or more functional groups that, when added to a polymer, can result in a "cured" or "crosslinked" polymer.

[0121] A maleimide-containing curing agent can contain one or more maleimide groups per molecule. Monofunctional maleimides have one maleimide group per molecule, such as N-phenylmaleimide or N-cyclohexylmaleimide. Polyfunctional maleimides have two or more maleimide groups per molecule. Maleimide curing agents are preferably soluble in commonly used solvents such as methyl ethyl ketone (MEK) and / or toluene. Preferably, the curing agent is a polyfunctional maleimide resin. Examples of polyfunctional maleimides include, but are not limited to, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide of Formula VII, bisphenol A diphenyl ether bismaleimide of Formula VIII, biphenyl-containing maleimide of Formula IX (e.g., MIR-3000 from Nippon Kayaku Co., Ltd.), and meta-arylene-containing maleimide of Formula X (e.g., MIR-5000 from Nippon Kayaku Co., Ltd.).

[0122] [ka] In the formula, 1 <n≦5である。

[0123] [ka] In the formula, 1 <n<5である。

[0124] Further examples of curing agents containing maleimide groups are oligomers of phenylmethanemaleimide, aliphatic bismaleimides (e.g., 1,6-bismaleimide-(2,2,4-trimethyl)hexane available from Daiwa Chemical Industry Co., Ltd.), or unhydrogenated dimers containing BMI (available as BMI-689 from Designer Molecules). Chain-extended bismaleimides are also possible, using dianhydrides in the BMI manufacturing process. BMI-3000 from Designer Molecules is an example of a commercially available chain-extended bismaleimide.

[0125] The curing agent containing a (meth)acrylic group can have one or more (meth)acrylic groups per molecule. Preferably, a multifunctional (meth)acrylate is used as the curing agent. Examples of multifunctional (meth)acrylates include, but are not limited to, tricyclodecane dimethanol dimethacrylate and (meth)acrylate-functional poly(arylene ether). The poly(arylene ether) is not particularly limited, but preferably has two or more (meth)acrylates per molecule. SA9000 is commercially available from SABIC and is a poly(arylene ether) with methacrylic end groups of formula XI.

[0126] [ka] n is an integer from 1 to 20.

[0127] The vinyl-containing curing agent may contain one or more vinyl groups per molecule. Preferably, a multifunctional vinyl-containing curing agent is used. Examples of multifunctional vinyl-containing curing agents include polybutadiene, polybutadiene-co-styrene, divinylbenzene, bis-vinyl-phenylethane, multifunctional vinyl aromatic copolymers, vinyl cyclic olefin resins, and poly(arylene ether). The poly(arylene ether) is not particularly limited, but preferably has two or more vinyl groups per molecule, such as OPE-2St, represented by the following formula XII, available from MGC.

[0128] [ka] n is an integer from 1 to 20.

[0129] In addition to the maleimide, (meth)acrylate, or vinyl-containing curing agent, an additional curing agent having an allyl group may be used. Preferably, a multifunctional allyl-containing curing agent is used. Examples of multifunctional allyl-containing curing agents are triallyl isocyanurate (TAIC), trimethallyl isocyanurate (TMAIC), diallyl alkyl isocyanurate, and diallyl phthalate.

[0130] Optionally, a radical polymerization initiator may be present in the thermosetting resin composition of the present disclosure. Examples of commonly used initiators include azo compounds and organic peroxides such as azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(N-butyl-2-methylpropionamide), benzoyl peroxide, t-butyl hydroperoxide, dicumyl peroxide, t-butyl perbenzoate, methyl ethyl ketone peroxide, cyclohexanone peroxide, acetyl peroxide, di-t-butyl peroxide, t-butyl perbenzoate, di(2-tert-butylperoxy-isopropyl)benzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3), and cumene hydroperoxide. These initiators may be used alone or in mixtures of two or more thereof. The type and amount of initiator used may vary depending on the intended use of the thermosetting resin composition and the required curing conditions. Preferably, the initiator may be used in an amount of 0.001 to 5 mass percent, preferably 0.001 to 1.0 mass percent, based on the resin composition.

[0131] The thermosetting resin composition may further include additives, including, but not limited to, (reactive) flame retardants, fillers, coupling agents, and any combination thereof, to further improve various properties of the thermosetting resin composition.

[0132] An example of a flame retardant is ethylene-1,2-bis(penta-bromo-phenyl), known as SAYTEX 8010, available from Albemarle, and ethylene-bis-tetra-bromo-phthalimide, known as SAYTEX BT93(W), available from Albemarle, Inc. An example of a halogen-free flame retardant is the bis(DOPO) derivative XP7866, also from Albemarle.

[0133] Examples of fillers include, but are not limited to, inorganic fillers such as silica, alumina, barium sulfate, talc, mica, kaolin, boehmite, beryllia, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, aluminum borate, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, zinc borate, zinc stannate, aluminum oxide, zirconia, mullite, magnesia, zinc oxide, titanium oxide, silicon carbide, silicon nitride, and boron nitride.

[0134] The inorganic filler can be used without surface treatment or can be surface treated with a silane coupling agent, for example, a methacrylsilane type, a vinylsilane type, a phenylaminosilane type, or an epoxysilane type, or the silane coupling agent can be added separately to the resin formulation containing the inorganic filler.

[0135] The thermosetting resin compositions of the present disclosure are particularly useful in preparing prepregs and / or metal clad laminates and printed circuit boards requiring low dielectric constants and low dielectric losses ("low loss").

[0136] As used herein, the term "prepreg" refers to a composite material made from a "pre-impregnated" substrate and a resin composition or semi-cured resin composition.

[0137] The present disclosure further relates to a prepreg comprising the thermosetting resin composition of the present disclosure. The prepreg comprises a reinforcing substrate and an uncured or semi-cured thermosetting resin composition. For the reinforcing substrate of the prepreg, known materials, such as natural fibers such as paper, can be used, but inorganic fibers, such as glass fiber, can also be used. Illustrative examples of glass fiber substrates include woven fabrics using E-glass, C-glass, D-glass, S-glass, NE-glass, L-glass, and Q-glass. E-glass woven fabrics are commonly used. In some embodiments, NE-glass, L-glass, or Q-glass are preferred to achieve lower dielectric loss.

[0138] As used herein, the "semi-cured" state refers to an intermediate stage (stage B). The intermediate stage is a stage between the stage in which the resin composition is uncured (stage A) and the stage in which the resin composition is fully cured (stage C). By heating the prepreg, the resin composition is fully cured to form a cured product.

[0139] The reinforcing substrate may be in the form of a woven fabric, a nonwoven fabric, a roving, a chopped strand mat, a surface mat, etc. On the other hand, the material and its form are selected depending on the intended use or performance of the molding material, and they may be used alone or in combination of two or more of the materials and their forms as necessary.

[0140] In this specification, a resin composition containing an organic solvent is referred to as a resin varnish. The organic solvent is not particularly limited as long as it dissolves the copolymer, curing agent, and the like. Examples include ketone-based solvents such as acetone, 2-butanone (MEK), and cyclohexanone, as well as hydrocarbon-based solvents such as toluene, xylene, and anisole. These organic solvents may be used alone or as a mixture of two or more of them. Non-soluble additives such as silica particles and potentially additive-based flame retardants can be dispersed in the resin varnish.

[0141] Prepregs can be produced, for example, by first impregnating a reinforcing substrate with a resin varnish and then removing the solvent. The solvent is removed by heating the impregnated, reinforced substrate. The temperature is preferably in the range of 80-200°C, because this temperature range allows for efficient removal of the organic solvent. On the one hand, the prepreg obtained by such a process can contain an uncured or semi-cured intermediate, depending on the drying conditions selected, while on the other hand, the prepreg after conversion to the C stage is considered a fully cured laminate.

[0142] The present disclosure also relates to a metal-clad laminate comprising a thermosetting resin composition according to the present disclosure. Metal-clad laminates, particularly copper-clad laminates for use in the fabrication of printed circuit boards, are well known in the art. Laminates generally comprise a (polymeric) substrate bonded to at least one thin sheet (foil) of a conductive material, such as copper. Depending on the desired use, the substrate may be affixed with metal foil on one or both sides and may be rigid or flexible depending on the composition of the substrate, the selection of reinforcing materials (if any), and the intended use of the laminate. Preferably, the polymeric substrate comprises a thermosetting resin composition according to the present disclosure.

[0143] The present disclosure further relates to printed circuit boards comprising prepregs and / or metal-clad laminates comprising thermosetting resin compositions according to the present disclosure.

[0144] The thermoset resin compositions of the present disclosure can be used in high-speed PCB applications such as backplanes for servers, switches, routers, and base stations, or in other applications such as radomes, automotive radar antenna covers, antenna substrates, and microchip packaging, especially for 5G applications.

[0145] Additional embodiments of the present disclosure may be described as embodiments in any of the listed embodiments below. It will be understood that any of the embodiments described herein may be used in conjunction with any other embodiment described herein to the extent the embodiments are not mutually exclusive.

[0146] 1. Formula I below: [ka] wherein R1 represents hydrogen or an aliphatic group, and R2 represents hydrogen, an aliphatic group, or an aromatic group; and a monomer unit of formula II: [ka] A thermosetting resin composition comprising a copolymer containing an aliphatic unsaturated imide of the formula: [wherein R3 is H or an alkyl group, R4 is an alkylidene group, and R5 is an alkanediyl group], and at least one curing agent containing a maleimide, (meth)acrylic acid, or vinyl group.

[0147] 2. The thermosetting resin composition of embodiment 1, wherein the maleimide curing agent is a multifunctional maleimide.

[0148] 3. The thermosetting resin composition of embodiment 2, wherein the multifunctional maleimide is selected from the group consisting of bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, biphenyl-containing maleimide, meta-arylene-containing maleimide, or 1,6-bismaleimido-(2,2,4-trimethyl)hexane.

[0149] 4. The thermosetting resin composition according to any one of embodiments 1 to 2, wherein the curing agent containing (meth)acrylic acid groups is a polyfunctional (meth)acrylic acid.

[0150] 5. The polyfunctional (meth)acrylic acid is represented by the following formula XI: [ka] [wherein n is an integer of 1 to 20] 5. The thermosetting resin composition of embodiment 4, represented by:

[0151] 6. The thermosetting resin composition of any one of embodiments 1 to 2, wherein the curing agent comprising a vinyl group is a multifunctional vinyl-containing curing agent. 7. The thermosetting resin composition of embodiment 6, wherein the multifunctional vinyl curing agent is selected from the group consisting of polybutadiene, polybutadiene-co-styrene, divinylbenzene, bis-vinylphenylethane, a multifunctional vinyl aromatic copolymer, a vinyl cyclic olefin resin, or a poly(arylene ether).

[0152] 8. The poly(arylene ether) has Formula XII: [ka] [In the formula, mn is an integer of 1 to 20] 8. The thermosetting resin composition of embodiment 7, represented by:

[0153] 9. The thermosetting resin composition of any one of embodiments 1 to 8, further comprising a radical initiator.

[0154] 10. The thermosetting resin composition of embodiment 1, wherein the molar ratio of monomer units of Formula I to unsaturated imide monomer units of Formula II ranges from 1:1 to 9:1.

[0155] 11. The copolymer has the following formula III: [ka] wherein R6 is selected from a saturated aliphatic group or an aromatic group. 2. The thermosetting resin composition of embodiment 1, further comprising a saturated imide monomer unit of

[0156] 12. The thermosetting resin composition of embodiment 11, wherein the molar ratio of unsaturated imide monomer units of Formula II to saturated imide monomer units of Formula III ranges from 1:0 to 1:2.

[0157] 13. The thermosetting resin composition of any one of embodiments 1 to 12, further comprising at least one additive selected from a flame retardant, a filler, a coupling agent, and any combination thereof.

[0158] 14. A prepreg comprising the thermosetting resin composition or a semi-cured product of the resin composition according to any one of embodiments 1 to 13 and a substrate.

[0159] 15. A metal-clad laminate comprising an insulating layer formed from a cured product of the prepreg according to embodiment 14 and at least one metal layer formed on one or both surfaces of the insulating layer.

[0160] 16. A printed circuit board comprising the metal-clad laminate of embodiment 15.

[0161] The present disclosure will now be described in detail, by way of illustration, with reference to the following non-limiting examples.

[0162] List of Abbreviations and Chemical Substances [Table 1]

[0163] Xylene was supplied by Carl Roth. Allylamine, acetone, and MEK were supplied by Sigma Aldrich. Noryl SA9000 is available from SABIC. XIRAN EF grade is available from Polyscope. BMI-5100 is available from Daiwa Kasei Kogyo Co., Ltd. RICON® 181 is available from Cray Valley.

[0164] Test items and test methods Neat resin (resin without additives) Fourier transform infrared spectroscopy (FTIR) was performed using an ALPHA II FT-IR spectrometer from Bruker equipped with a PLATINUM-ATR module.

[0165] Size exclusion chromatography (SEC) was performed using a PSS WinGPC system manufactured by PSS. A 5 μm, 8.0 mm × 50 mm pre-column guard was used, followed by three 1000 Å columns: 8.0 mm × 300 mm and 8.0 mm × 300 mm. A differential refractometer (RID) was used as the detector. The eluent was 5% acetic acid in THF. The injection volume was 100 μL, and the flow rate was 1.0 ml / min. The sample concentration was 5 g / L. The temperature was 23 °C. Molecular weights were calculated using calibration polystyrene molar mass standards.

[0166] Neat resin casting: Dk and Df were measured at room temperature at 5.1 GHz using a split post dielectric resonator (SPDR) equipped with a Microwave Frequency Q-Meter (5 GHz) from QWED Corp. The neat resin castings were measured immediately after post-baking at 200°C for 1 hour.

[0167] Differential scanning calorimetry (DSC) was performed using a DSC2 STARe (METTLER TOLEDO). DSC measurements were performed on the prepared neat resin castings from 30°C to 220°C using a heating rate of 20°C / min and a cooling rate of 10°C / min under a nitrogen flow of 50 mL / min. A second heating rate of 20°C / min was performed from 30 to 250°C. The sample mass was approximately 10 mg. Data analysis was performed using STARe software. The midpoint function was used to determine the crosslinking Tg values ​​of the prepared neat resin castings.

[0168] Thermogravimetric analysis (TGA) was performed using a TGA2 STARe from METTLER TOLEDO. First, the TGA samples were dried using a TGA with a heating rate of 10°C / min from 30°C to 200°C under a nitrogen flow of 50 mL / min. The dried samples were then measured by TGA using a heating rate of 10°C / min from 30°C to 700°C under a nitrogen flow of 50 mL / min. Data analysis was performed using STARe software. A step horizon function (start temperature of 50°C) was used to determine the thermal decomposition temperature at 5 mass percent mass loss and residue at 600°C. [Example]

[0169] Examples and Comparative Examples Example 1 (Synthesis of XIRAN EL819) A 1000 mL four-neck round-bottom flask equipped with a Dimroth condenser, mechanical stirrer, nitrogen inlet, and pressure-equalizing dropping funnel was charged with XIRAN EF80 (0.201 mol anhydride). 360 g of xylene was added to the round-bottom flask. 0.221 mol of allylamine was slowly added. The reaction temperature was raised to 40°C over 1.5 hours to form the amide acid. 0.050 mol of triethylamine (TEA) was then added, and the reaction mixture was heated to reflux. The solution was refluxed for 12 hours and cooled to room temperature. An additional 0.060 mol of allylamine was added. The reaction mixture was heated to 40°C over 1.5 hours. 0.004 mol of TEA was added, and the solution was refluxed for an additional 12 hours. The solution was cooled to room temperature, the solvent was removed on a rotary evaporator, and the resulting resin powder was further dried overnight at 80°C in a vacuum oven. FT-IR analysis showed the presence of imide and allyl groups. The modified polymer was soluble in commonly used solvents, including acetone, MEK, toluene, xylene, and anisole. No chain extension or crosslinking of the modified polymer occurred, as shown by SEC measurements.

[0170] Example 2 (Synthesis of XIRAN EL419) A 1000 mL four-neck round-bottom flask equipped with a Dimroth condenser, mechanical stirrer, nitrogen inlet, and pressure-equalizing dropping funnel was charged with XIRAN EF40 (0.321 mol anhydride). 394 g of xylene was added to the round-bottom flask. 0.353 mol of allylamine was slowly added. The reaction temperature was raised to 40°C over 1.5 hours to form the amide acid. 0.064 mol of triethylamine (TEA) was then added, and the reaction mixture was heated to reflux. The solution was refluxed for 12 hours and cooled to room temperature. An additional 0.060 mol of allylamine was added. The reaction mixture was raised to 40°C over 1.5 hours. 0.005 mol of TEA was added, and the solution was refluxed for an additional 12 hours. The solution was cooled to room temperature, the solvent was removed on a rotary evaporator, and the resulting resin powder was further dried overnight in a vacuum oven at 80°C. FT-IR analysis showed the presence of imide and allyl groups. The modified polymer was soluble in commonly used solvents, including acetone, MEK, toluene, xylene, and anisole. No chain extension or crosslinking of the modified polymer occurred, as shown by SEC measurements.

[0171] Methods for preparing varnishes and neat resin castings First, a varnish is prepared by dissolving the components in MEK according to the formulations shown in Tables 1 and 3. Once all components are dissolved, the solvent is removed in an oven under vacuum at 65°C overnight to obtain a resin powder. The resulting resin powder is used to make neat resin castings using a vacuum hot press with a hot press cure schedule of 220°C for 1.5 hours. Example 4 was thermally crosslinked without an initiator using a hot press cure schedule of 240°C for 1.5 hours. The neat resin castings were removed from the mold and post-cured (post-baked) in a vacuum oven for an additional hour at 200°C. The neat resin castings are approximately 1 mm thick.

[0172] Results of Examples and Comparative Examples The resin compositions (parts per hundred parts of resin) of the neat resin castings prepared and the dielectric results tested are shown in Tables 1 and 3 below and in FIG.

[0173] 1 shows the TGA curves of Example 3 and Comparative Example 3. As can be seen from the figure, Ex3 exhibits improved thermal stability at temperatures above 300°C.

[0174] Table 1 Table 1 below refers to Examples (Ex) 1-5 and Comparative Examples (CE) 1-3 with the formulations shown. * indicates that the dielectric properties could not be determined (deformed during post-cure). [Table 2]

[0175] As can be seen from Table 1, Examples Ex1-5 exhibit excellent dielectric properties with Df values ​​ranging from 0.0012 to 0.0038. The allyl-modified copolymer could be thermally crosslinked with maleimide without the use of a radical initiator (Ex4), resulting in reduced dielectric loss values ​​compared to Examples Ex1. Surprisingly, the dielectric loss of CE2 is high, with a Df value of 0.0121. The dielectric properties of Examples CE1 with RICON181 addition are better than those of CE2, but the Dk and Df values ​​are still higher compared to those of Examples Ex1-5. The dielectric properties of Examples CE3 could not be measured due to deformation of the neat resin casting during post-cure in a vacuum oven.

[0176] Table 2. Thermal properties of selected neat resin castings Examples Ex1-5 all show a large improvement in Td5 and have substantially higher residues at 600°C compared to Comparative Example 3.

[0177] [Table 3]

[0178] Examples E1-E5 all show large improvements in Td5 and have substantially higher residues at 600° C. compared to Comparative Example C3.

[0179] Table 3 Dielectric properties and Tg of neat resin castings Table 3 refers to Examples 6-8, which are of the formulations shown therein.

[0180] The formulation containing Xiran EL419 has a Df below 0.003. With increasing proportion of BMI5100 in the formulation, the Df value of the cured resin system changes little, but the T g The values ​​increase with increasing BMI (5100).

[0181] [Table 4]

Claims

1. Formula I below: 【Chemistry 1】 [In the formula, R １ R represents hydrogen or an aliphatic group. ２ [This represents hydrogen, an aliphatic group, or an aromatic group.] The monomer units, and the following formula II: 【Chemistry 2】 [In the formula, R ３ is H or alkyl group, R ４ R is an alkylidene group, ５ [This is an alkanediyl group] A thermosetting resin composition comprising a copolymer containing an aliphatic unsaturated imide and at least one curing agent containing a maleimide group, a (meth)acrylate group, or a vinyl group.

2. The thermosetting resin composition according to claim 1, wherein the curing agent containing a maleimide group is a polyfunctional maleimide, and the polyfunctional maleimide is selected from the group consisting of bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, biphenyl-containing maleimide, meta-arylene-containing maleimide, or 1,6-bismaleimide-(2,2,4-trimethyl)hexane.

3. The curing agent containing a (meth)acrylate group is defined by the following formula XI: 【Transformation 3】 [n is an integer between 1 and 20] The thermosetting resin composition according to claim 1, which is a polyfunctional (meth)acrylate represented by .

4. The thermosetting resin composition according to claim 1, wherein the curing agent containing a vinyl group is a polyfunctional vinyl-containing curing agent selected from the group consisting of polybutadiene, polybutadiene-co-styrene, divinylbenzene, bis-vinylphenylethane, polyfunctional vinyl aromatic copolymer, vinyl cyclic olefin resin, or poly(arylene ether).

5. The aforementioned poly(arylene ether) is given by the following formula XII: 【Chemistry 4】 [n is an integer between 1 and 20] The thermosetting resin composition according to claim 4, as represented by [the specified formula].

6. The thermosetting resin composition according to claim 1, further comprising a radical initiator.

7. The molar ratio of monomer units in formula I to unsaturated imide monomer units in formula II is between 1:1 and 9:

1. A thermosetting resin composition according to claim 1, which is within the range of [specified range].

8. The copolymer is given by the following formula III: 【Transformation 5】 [In the formula, R ６ [The group is selected from saturated aliphatic groups or aromatic groups.] The thermosetting resin composition according to claim 1, further comprising saturated imide monomer units.

9. The thermosetting resin composition according to claim 8, wherein the molar ratio of unsaturated imide monomer units of formula II to saturated imide monomer units of formula III is in the range of 1:0 to 1:

2.

10. A prepreg comprising the thermosetting resin composition described in claim 1 or a semi-cured product of the thermosetting resin composition, and a substrate.

11. (i) Styrene-maleic anhydride copolymer (SMA) is contacted with an unsaturated aliphatic amine. Furthermore, the process of preparing the styrene-maleimide copolymer, (ii) A step of crosslinking a styrene-maleimide copolymer with at least one curing agent in the presence of one or more radical polymerization initiators, of which optional. A thermosetting resin composition prepared by a process including, The styrene-maleimide copolymer is defined by the following formula I: 【Transformation 6】 [wherein R1 is hydrogen or an aliphatic group, and R2 is hydrogen, an aliphatic group, or an aromatic group] monomer units and Formula II below: 【Transformation 7】 [In the formula, R3 is H or an aliphatic group, R4 is an alkylidene group, and R5 is an alkylene group.] A thermosetting resin composition containing an aliphatic unsaturated imide.

12. The styrene-maleimide copolymer is defined by the following formula III: 【Transformation 8】 [In the formula, R ６ [These are saturated aliphatic groups or aromatic groups.] The thermosetting resin composition according to claim 11, further comprising the saturated imide monomer.

13. The thermosetting resin composition according to claim 11, wherein the at least one curing agent comprises one or more maleimide groups, (meth)acrylate groups, and / or vinyl groups.

14. The thermosetting resin composition according to claim 11, wherein the at least one curing agent comprises a polyfunctional maleimide selected from bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, biphenyl-containing maleimide, meta-arylene-containing maleimide, and 1,6-bismaleimide-(2,2,4-trimethyl)hexane.

15. The above-mentioned at least one curing agent is defined by the following formula XI: 【Chemistry 9】 [In the formula, n is an integer between 1 and 20.] The thermosetting resin composition according to claim 11, wherein the polyfunctional (meth)acrylate is a polyfunctional (meth)acrylate.

16. The thermosetting resin composition according to claim 11, wherein the at least one curing agent is a polyfunctional vinyl-containing curing agent selected from polybutadiene, polybutadiene-co-styrene, divinylbenzene, bis-vinylphenylethane, polyfunctional vinyl aromatic copolymer, vinyl cyclic olefin resin, and poly(arylene ether).

17. The aforementioned poly(arylene ether) is given by the following formula XII: 【Chemistry 10】 [In the formula, n is an integer between 1 and 20.] The thermosetting resin composition according to claim 16.

18. The thermosetting resin composition according to claim 11, wherein the styrene-maleimide copolymer has a molar ratio of monomer units of formula I to unsaturated imide monomer units of formula II in the range of about 1:1 to 9:

1.

19. The thermosetting resin composition according to claim 12, wherein the molar ratio of unsaturated imide monomer units of formula II to saturated imide monomer units of formula III is in the range of about 1:0 to 1:

2.

20. The thermosetting resin composition according to claim 11, wherein step (ii) is performed in the presence of a substrate.

21. The thermosetting resin composition according to claim 20, wherein step (ii) is performed using heating that does not provide complete curing of the thermosetting resin composition, and the incomplete curing results in a prepreg composition of the thermosetting resin composition.

22. A metal-clad laminate comprising the thermosetting resin composition according to claim 21, prepared by a process comprising the step of contacting the thermosetting resin composition with one or more metal layers prior to the completion of step (ii).

23. i) An insulating layer comprising the thermosetting resin composition described in claim 20, ii) One or more metal layers on one or both surfaces of the insulating layer A metal-clad laminate according to claim 22, including the above.

24. It comprises a styrene-maleimide copolymer crosslinked with at least one curing agent, The styrene-maleimide copolymer is defined by the following formula I: 【Chemistry 11】 [In the formula, R1 is hydrogen or an aliphatic group, and R2 is hydrogen, an aliphatic group, or an aromatic group.] monomer units and Formula II below: 【Chemistry 12】 [In the formula, R3 is H or an aliphatic group, R4 is an alkylidene group, and R5 is an alkylene group.] Contains aliphatic unsaturated imides, Thermosetting resin composition.

25. The styrene-maleimide copolymer is defined by the following formula III: 【Chemistry 13】 [In the formula, R ６ [These are saturated aliphatic groups or aromatic groups.] The thermosetting resin composition according to claim 24, further comprising the saturated imide monomer.

26. The thermosetting resin composition according to claim 24, wherein the at least one curing agent comprises one or more maleimide groups, (meth)acrylate groups, and / or vinyl groups.

27. The thermosetting resin composition according to claim 24, wherein the at least one curing agent comprises a polyfunctional maleimide selected from bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, biphenyl-containing maleimide, meta-arylene-containing maleimide, and 1,6-bismaleimide-(2,2,4-trimethyl)hexane.

28. The above-mentioned at least one curing agent is defined by the following formula XI: 【Chemistry 14】 The thermosetting resin composition according to claim 24, wherein n is a polyfunctional (meth)acrylate of the formula [wherein n is an integer from 1 to 20].

29. The thermosetting resin composition according to claim 24, wherein the at least one curing agent is a polyfunctional vinyl-containing curing agent selected from polybutadiene, polybutadiene-co-styrene, divinylbenzene, bis-vinylphenylethane, polyfunctional vinyl aromatic copolymer, vinyl cyclic olefin resin, and poly(arylene ether).

30. The aforementioned poly(arylene ether) is given by the following formula XII: 【Chemistry 15】 [In the formula, n is an integer between 1 and 20.] The thermosetting resin composition according to claim 29.

31. The thermosetting resin composition according to claim 24, wherein the molar ratio of monomer units of formula I to unsaturated imide monomer units of formula II in the styrene-maleimide copolymer is in the range of about 1:1 to 9:

1.

32. The thermosetting resin composition according to claim 25, wherein the molar ratio of unsaturated imide monomer units of formula II to saturated imide monomer units of formula III is about 1:0 to 1:

2.

33. The thermosetting resin composition according to claim 24, further comprising a base material.

34. The thermosetting resin composition according to claim 33, wherein the styrene-maleimide copolymer is not completely crosslinked by the at least one curing agent, thereby providing a prepreg composition of the thermosetting resin composition.

35. A metal-clad laminate comprising the thermosetting resin composition according to claim 33 or 34, wherein the thermosetting resin composition comprises one or more metal layers.

36. i) An insulating layer comprising the thermosetting resin composition described in claim 33, ii) One or more metal layers on one or both surfaces of the insulating layer The metal-clad laminate according to claim 35, including the above.

37. A printed circuit board comprising the thermosetting resin composition according to claim 34 or the metal-clad laminate according to claim 35 or 36.

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