Low dielectric constant resin-forming composition, low dielectric resin component, and electronic device using same

Abstract

Provided is a low dielectric constant resin-forming composition that has improved low dielectric characteristics while maintaining high heat dissipation characteristics (thermal conductivity) or, if possible, improving such characteristics, and while maintaining solubility in solvents or in other low dielectric resins.　This low dielectric constant resin-forming composition contains a liquid crystal compound that is represented by formula (1) and that has polymerizable groups at both terminals. When a cured product is obtained by curing the composition without adding thereto an inorganic filler, the relative permittivity of the cured product at 10 GHz is lower than 3.0. Z1 and Z2 each represent a single bond or an alkylene having 1 or 2 carbon atoms, A1, A2, and A3 each represent 1,4-cyclohexylene or 1,4-phenylene, R1a and R1b each represent a group selected from polymerizable groups represented by formulae (PG-1a), (PG-1b), and (PG-1c), and p represents an integer of 0-2. m represents an integer of 1-12, n represents an integer of 0-12, and Y represents hydrogen or methyl.

Description

Composition for forming low dielectric constant resins, low dielectric resin components, and electronic devices using the same.

[0001] The present invention relates to a low dielectric resin forming composition using a polymerizable liquid crystalline compound that is easily soluble in a solvent and readily copolymerized with other low dielectric resins, in order to enable the production of low dielectric resins used in electronic components and electronic substrates that handle high frequencies for 5G and 6G using conventional production equipment and processes, as well as low dielectric resin components and electronic devices using this composition.

[0002] In recent years, with the advent of 5G and beyond-5G and 6G communication devices, the frequency of electrical signals on electronic circuit boards and the frequency of radio waves transmitted and received by antennas have increased, leading to problems with signal loss due to signal processing circuit boards and antenna boards. Furthermore, insulating materials that do not hinder the acceleration of signal transmission speed are desired for the silicon chips and wiring materials inside semiconductor chips. Therefore, there is a demand for resin materials with low dielectric constant and low dielectric loss tangent used in substrates and insulating materials. Instead of conventional polyimide and epoxy resins, resins such as liquid crystal polymer (LCP), polyphenylene ether (PPE), cycloolefin polymer (COP), and fluororesin (PTFE) are beginning to be used. Low-dielectric substrates currently have a dielectric constant of 3.0 or less, and those containing high thermal conductivity fillers have a dielectric constant of 3.5 or less. There is a need for the development of materials with even lower dielectric constants. (Non-Patent Literature 1)

[0003] However, current high-frequency substrate materials are mainly thermoplastic resins, which have many drawbacks, such as requiring molding and bonding at high temperatures and having poor adhesion to other resins and to copper foil electrodes. Patent document 1 describes an investigation into lowering the dielectric constant of liquid crystal polymers by examining their molecular structure. However, liquid crystal polymers have a high melting point and require processing temperatures of 350°C or higher, making thermal lamination and bonding to copper foil difficult.

[0004] Patent Document 2 describes studies on varnish formation by increasing solubility in organic solvents. By studying the molecular structure of PPE resin, it became possible to form PPE resin films by coating, making it usable as an insulating varnish. However, there are many problems, such as the need to use organic solvents with high dissolving power and the limited freedom in polymer design when trying to adjust properties other than dielectric properties. Therefore, there is a need for the development of a low dielectric constant resin that can be coated and easily cured, like an insulating coating varnish.

[0005] Regarding insulating materials for semiconductors, Patent Document 3 describes a low-dielectric epoxy resin with increased crosslinking. Thus, currently mainstream low-dielectric epoxy compounds are often polyfunctional with many crosslinking points, and these crosslinkings are designed to suppress molecular vibrations that cause dielectric loss. However, even with these measures, the dielectric constant is not sufficiently low, and there are many cases where epoxy resins are replaced by other resins. Furthermore, with the increase in communication volume, the amount of heat generated by semiconductor chips for data processing has also increased, and because power semiconductor chips that generate a lot of heat are mounted on antenna substrates, the heat dissipation properties of electronic substrates are also required, thus creating a demand for the development of resins with high thermal conductivity. Patent Document 4 describes that when a highly linear polymerizable liquid crystalline compound is oriented and cured, it achieves higher thermal conductivity in the orientation direction than ordinary thermosetting resins, and Patent Document 5 describes that by compounding a polymerizable liquid crystalline compound with a heat dissipation filler, it is possible to form a thermosetting resin material with even higher thermal conductivity. Furthermore, Patent Document 6 describes a composition for forming a resin using polymerizable liquid crystal that has both low dielectric constant and high thermal conductivity. Prioritizing high thermal conductivity, and therefore emphasizing affinity and adhesion with inorganic materials such as thermal conductive fillers, the molecule has a structure containing multiple ether bonds. Since the oxygen atoms in these ether bonds increase the polarity within the molecule, reducing the number of oxygen atoms is necessary when designing molecules that prioritize low dielectric constant. Furthermore, these oxygen atoms also contribute to the absorption of moisture from the air, further degrading the dielectric properties.

[0006] Japanese Patent Publication No. 2019-189734, Japanese Patent Publication No. 2009-67894, Japanese Patent No. 7499994, Japanese Patent Publication No. 2006-265527, International Publication No. 2015 / 170744, International Publication No. 2022 / 092063

[0007] Hiroyuki Fukunaga and Yoshiyuki Hamato, "Fundamentals and Selection of High-Speed / High-Frequency Circuit Boards," RF World, CQ Publishing, 2017, No. 40, pp. 97-111.

[0008] The problem that this invention aims to solve is to realize a polymerizable liquid crystal with enhanced low dielectric properties while maintaining high heat dissipation (thermal conductivity), and if possible improving these properties, and while maintaining solubility in solvents and other low dielectric resins, in order to solve the problems of conventional polymerizable liquid crystals that aim for low dielectric and high thermal conductivity. By using the low dielectric resin forming composition of this invention, it is possible to provide a material suitable for applications such as next-generation communication equipment and radar in the high-frequency range.

[0009] As a result of diligent research to solve the above problems, the inventors have found that a composition containing a polymerizable liquid crystalline compound (1) in which alkylene linkers are introduced into linkers connected to both sides of the molecular core structure can realize a low dielectric constant resin-forming composition that exhibits high heat resistance, low dielectric constant and low dielectric loss tangent in the high-frequency region, and high heat dissipation after curing, thus completing the present invention. The inventors have confirmed that by introducing an alkylene linker from which the oxygen of the polar atom in the polar group (oxygen atom in the alkylene oxy portion) has been removed from a linker containing an oxygen atom, such as a conventional alkylene ether linker, the polarity of the linker is reduced, the dielectric properties of the compound as a whole are further improved, the polymerizable liquid crystalline compound (1) is highly transparent, and phonon conduction in the molecular chain direction is fast. Thus, the polymerizable liquid crystalline compound (1) used in the present invention has a lower dielectric constant and lower dielectric loss compared to conventional compounds. Therefore, the cured product obtained by curing the polymerizable liquid crystalline compound (1) has very low dielectric properties, and it is possible to produce composite materials with high transparency and high thermal conductivity. By using the low dielectric constant resin-forming composition according to the present invention, it is possible to provide materials suitable for applications such as next-generation communication equipment and radar in the high-frequency range.

[0010] The present invention has the following configuration: [1] A composition for forming a low dielectric constant resin, comprising a liquid crystalline compound represented by formula (1) having polymerizable groups at both ends, wherein the relative dielectric constant of the cured product at 10 GHz is less than 3.0 when the composition is cured without the addition of an inorganic filler. In formula (1), Z １ and Z ２ These are independently single-bonded or C1-C2 alkylenes; A １ A ２ , and A ３ R is independently 1,4-cyclohexylene or 1,4-phenylene, and in the rings of 1,4-cyclohexylene and 1,4-phenylene, at least one hydrogen may be replaced by an alkyl group having 1 to 6 carbon atoms; R １ａ and R １ｂis independently a group selected from polymerizable groups represented by the following formulas (PG-1a), (PG-1b), and (PG-1c); p is an integer of 0 to 2; in the formula, Z ２ or A ３ When there are a plurality of them, they may be the same or different. In the formulas (PG-1a), (PG-1b), and (PG-1c), m is an integer of 1 to 12, n is an integer of 0 to 12, and Y is hydrogen or methyl.

[0011] [2] In the compound represented by the formula (1), A １ , A ２ , and A ３ are 1,4-cyclohexylene, and in the ring of 1,4-cyclohexylene, at least one hydrogen may be replaced by an alkyl having 1 to 6 carbon atoms. The composition for forming a low dielectric constant resin according to [1].

[0012] [3] The melting point of the liquid crystalline compound represented by the formula (1) is 200°C or lower or the transition temperature from the nematic phase to the liquid is 200°C or lower. The composition for forming a low dielectric constant resin according to [1] or [2].

[0013] [4] The composition for forming a low dielectric constant resin according to [1] or [3], containing at least one selected from liquid crystalline compounds having polymerizable groups at both ends and represented by the formulas (1-1) to (1-4). In the formulas (1-1) to (1-4), Z ２ is a single bond or an alkylene having 1 to 2 carbon atoms; A ３ is 1,4-cyclohexylene or 1,4-phenylene, and in the rings of 1,4-cyclohexylene and 1,4-phenylene, at least one hydrogen may be replaced by an alkyl having 1 to 6 carbon atoms; p is 1 or 2; X is an alkyl having 1 to 6 carbon atoms; s is an integer of 0 to 4; m is an integer of 1 to 12; Me is methyl; in the formula, when there are a plurality of Z ２ , A ３ , p, or X, they may be the same or different, and when there are a plurality of s or m, they may be the same or different.

[0014] [5] A low dielectric constant resin-forming composition according to [1] or [3], comprising at least one selected from liquid crystalline compounds represented by formulas (1-5) to (1-8) having polymerizable groups at both ends. In formulas (1-5) to (1-8), Z ２ A is an alkylene with a single bond or 1-2 carbon atoms; ３ is 1,4-cyclohexylene or 1,4-phenylene, where at least one hydrogen in the rings of 1,4-cyclohexylene and 1,4-phenylene may be replaced by an alkyl group having 1 to 6 carbon atoms; p is 1 or 2; X is an alkyl group having 1 to 6 carbon atoms; s is an integer from 0 to 4; n is an integer from 0 to 12; and in the formula, Z ２ A ３ If there are multiple s, p, or X, they may be the same or different, and if there are multiple s or n, they may be the same or different.

[0015] [6] A low dielectric constant resin-forming composition according to [1] or [3], comprising at least one selected from liquid crystalline compounds having polymerizable groups at both ends, represented by formulas (1-9) to (1-12). In formulas (1-9) to (1-12), Z ２ A is an alkylene with a single bond or 1-2 carbon atoms; ３ is 1,4-cyclohexylene or 1,4-phenylene, where at least one hydrogen in the rings of 1,4-cyclohexylene and 1,4-phenylene may be replaced by an alkyl group having 1 to 6 carbon atoms; p is 1 or 2; X is an alkyl group having 1 to 6 carbon atoms; s is an integer from 0 to 4; n is an integer from 0 to 12; and in the formula, Z ２ A ３ If there are multiple s, p, or X, they may be the same or different, and if there are multiple s or n, they may be the same or different.

[0016] [7] A low dielectric constant resin-forming composition according to any one of [1], [3], and [4], comprising at least one selected from liquid crystalline compounds having polymerizable groups at both ends, represented by formulas (1-1-1), (1-1-2), (1-3-1), and (1-3-2). In formulas (1-1-1), (1-1-2), (1-3-1), and (1-3-2), Me is methyl, m is an integer from 1 to 12, and the multiple m in a formula may be the same or different.

[0017] [8] A low dielectric constant resin-forming composition according to any one of [1], [3], and [5], comprising at least one selected from liquid crystalline compounds having polymerizable groups at both ends, represented by formulas (1-5-1), (1-5-2), (1-7-1), and (1-7-2). In formulas (1-5-1), (1-5-2), (1-7-1), and (1-7-2), Me is methyl, n is an integer from 0 to 12, and the multiple n in a formula may be the same or different.

[0018] [9] A low dielectric constant resin-forming composition according to any one of [1], [3], and [6], comprising at least one selected from liquid crystalline compounds having polymerizable groups at both ends, represented by formulas (1-9-1), (1-9-2), (1-11-1), and (1-11-2). In formulas (1-9-1), (1-9-2), (1-11-1), and (1-11-2), Me is methyl, n is an integer from 0 to 12, and the multiple n in the formulas may be the same or different.

[0019] The low dielectric constant resin-forming composition according to [1], comprising at least one selected from liquid crystalline compounds having polymerizable groups at both ends, represented by formula (1-1-1) in [7] and formula (1-5-1) in [8].

[0020]

[11] A low dielectric constant resin-forming composition according to any one of [1] to

[10] , comprising at least one selected from (A) and (B) below: (A) A polymer of a liquid crystalline compound having polymerizable groups at both ends represented by formula (1) (B) A polymerizable compound other than a liquid crystalline compound having polymerizable groups at both ends represented by formula (1)

[0021]

[12] A composition for forming a low dielectric constant resin according to any one of [1] to

[11] , comprising a nonpolymerizable liquid crystalline compound.

[0022]

[13] A low dielectric constant resin forming composition according to any one of [1] to

[12] , comprising an inorganic filler, wherein the thermal conductivity of the cured product obtained by curing the composition is 1 W / m·K or more.

[0023]

[14] A low dielectric constant resin forming composition according to any one of [1] to

[13] , comprising an inorganic filler which is a nitride filler, wherein the thermal conductivity of the cured product obtained by curing the composition is 10 W / m·K or more.

[0024]

[15] The low dielectric constant resin forming composition according to

[13] , wherein the inorganic filler is at least one selected from the group consisting of silicon oxide compounds of spherical silica, pulverized silica, hollow silica and fumed silica, metal nitrides of aluminum nitride, boron nitride and silicon nitride, diamond, graphite, silicon carbide, and metal oxides of magnesium oxide, aluminum oxide, zinc oxide, titanium oxide, tin oxide and calcium oxide.

[0025]

[16] A composition for forming a low dielectric constant resin according to any one of [1] to

[15] , comprising a fibrous reinforcing agent.

[0026]

[17] The low dielectric constant resin forming composition according to

[16] , wherein the fibrous reinforcing agent is at least one selected from the group consisting of glass cloth, low dielectric glass cloth, carbon fiber, carbon nanotube, polyamide fiber, aramid fiber, poly(p-phenylenebenzobisoxazole) fiber, liquid crystalline polyester fiber, cellulose nanofiber, silicate whisker, alumina whisker, magnesium oxide whisker, zinc oxide whisker, and aluminum nitride whisker.

[0027]

[18] A low dielectric constant resin insulating film which is a polymer molded article obtained by curing a low dielectric constant resin forming composition according to any one of items [1] to

[17] with heat or ultraviolet light.

[0028]

[19] A low dielectric constant resin film or low dielectric constant resin sheet, which is a polymer molded article obtained by curing a low dielectric constant resin-forming composition according to any one of items [1] to

[17] with heat or ultraviolet light.

[0029]

[20] A low dielectric constant resin part which is a polymer molded article obtained by curing a low dielectric constant resin forming composition according to any one of items [1] to

[17] with heat or ultraviolet light.

[0030]

[21] Electronic equipment using a polymer molded article obtained by curing a low dielectric constant resin forming composition according to any one of items [1] to

[17] with heat or ultraviolet light.

[0031] The composition containing a polymerizable liquid crystalline compound in which two single bonds or alkylene linkers are linked to the core structure of the molecule used in the present invention is a low dielectric constant resin-forming composition that exhibits high heat resistance and dielectric properties of low dielectric constant and low dielectric loss tangent in the high-frequency range after curing, and is a composition that can be prepared in a varnish-like state using no solvent or a small amount of organic solvent. Furthermore, in addition to the above properties, it is a low dielectric constant resin-forming composition that exhibits high transparency or high heat dissipation. The cured product obtained by curing the composition of the present invention has low dielectric properties, high heat dissipation and transparency, and excellent properties in at least one of the following: chemical stability, heat resistance, hardness and mechanical strength. For example, it is suitable for various applications such as low dielectric circuit boards, low dielectric antenna substrates, low dielectric coatings, low dielectric adhesives, next-generation communication equipment and radar in the high-frequency range.

[0032] Figure 1 shows a simple mold made of polyimide film, which was prepared for use in the [Examples] and [Comparative Examples] to control the thickness of the molten composition and prevent the molten material from flowing out during dielectric property measurements.

[0033] The following describes in detail polymerizable liquid crystalline compounds in which two single bonds or alkylene linkers are linked to the core structure of the molecule used in the present invention, a low dielectric constant resin forming composition containing at least one selected from the polymerizable liquid crystalline compounds, a low dielectric constant resin insulating film, a low dielectric constant resin film, a low dielectric constant resin sheet, a low dielectric constant resin component, and electronic equipment using the polymer molded product, as well as methods for manufacturing these. The terms used herein are defined as follows: "Liquid crystalline compound" is a general term for compounds having a liquid crystalline phase such as a nematic phase or a smectic phase, and compounds that do not have a liquid crystalline phase but have physical properties unique to liquid crystals such as dielectric anisotropy, refractive index anisotropy, and magnetic susceptibility anisotropy, and are useful as components of liquid crystal compositions. Orientation processing becomes easy in the liquid crystal temperature range, and molecular orientation can be controlled as in stretching processing in thermoplastic resins. "Compound (1)" means the polymerizable liquid crystalline compound represented by formula (1), and may also mean at least one of the compounds represented by formula (1). The same applies to "compound (1-1)," etc., and compound (1-1), compound (1-2), and compound (1-3), etc., are sometimes collectively referred to as "compound (1)." In one compound (1), two X １ They may be the same or different. Multiple compounds (1) are R ｂ When there are any two R ｂ These may be the same or different. This rule also applies to other symbols, groups, etc., such as m. In this specification, Me also means methyl in compounds other than compound (1). "Polymer (1)" means at least one polymer obtained by polymerizing compound (1), that is, a polymer of a liquid crystalline compound having polymerizable groups at both ends represented by formula (1). In addition, similar to "compound (1)", the polymers of compound (1-1), compound (1-2), and compound (1-3), etc., may also be collectively referred to as "polymer (1)". "Composition (1)" means a composition containing at least one selected from compound (1), that is, the low dielectric constant resin forming composition of the present invention.

[0034] 1) Compound (1) The polymerizable liquid crystalline compound (1) used in the present invention, in which two single bonds or alkylene linkers are linked to the core structure of the molecule (hereinafter sometimes referred to as Compound (1)), has a liquid crystal skeleton (rod-shaped mesogenic skeleton) and polymerizable groups, preferably with few conjugated or polar groups, high molecular linearity and symmetry, high polymerization reactivity, a wide liquid crystal phase temperature range, and good miscibility. Compound (1) is easily homogenized when mixed with other liquid crystalline compounds or polymerizable compounds. In addition, because Compound (1) has a very small number of oxygen atoms compared to alkylene ether linker compounds having a similar structure, the overall polarity of the molecule is low, and it exhibits low dielectric constant and low dielectric loss. Therefore, polymer molded articles obtained by curing a low dielectric constant resin-forming composition using Compound (1) with heat or ultraviolet light can be used as suitable materials for applications requiring low dielectric loss, such as low dielectric constant resin insulating films, low dielectric constant resin films, and low dielectric constant resin sheets. The melting point of compound (1) is preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 160°C or lower, from the viewpoint of molding and curing temperature, or the transition temperature from the nematic phase to the liquid of compound (1) is preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 160°C or lower, from the viewpoint of molding and curing temperature. Compound (1) is composed of groups such as ring structures, bonding groups, linking groups and terminal groups. Terminal group R of compound (1) １ａ or R １ｂ , ring structure A １ A ２ Or A ３ , side group X, bonding group Z １ or Z ２ , linking group in terminal group - (CH ２ ) ｍ - or - (CH ２ ) ｎBy appropriately selecting the elements, physical properties such as the liquid crystal phase region can be arbitrarily adjusted. In the linking group, m is an integer from 1 to 12, and n is an integer from 0 to 12. In this specification, the terminal group, which is selected from polymerizable groups, is a group composed of a group that functions only for polymerization ((meth)acryloyloxy, oxyranil, or maleimide residue, i.e., 1H-pyrrole-2,5-dione-1-yl) and a linking group that functions as a linker (single bond or alkylene). The effects of the terminal group, ring structure, linking group, and type of bonding group on the physical properties of compound (1), as well as preferred examples thereof, are described below. The ring structure, bonding group, and terminal group are referred to as "ring structure A," "bonding group Z," and "terminal group R," respectively. １ They are sometimes referred to collectively as "[...]."

[0035] <Terminal group R １ : R １ａ and R １ｂ > Terminal group R of compound (1) １ａ and R １ｂ This group is independently selected from the polymerizable groups represented by the following formulas (PG-1a), (PG-1b), and (PG-1c). In formulas (PG-1a), (PG-1b), and (PG-1c), m is an integer from 1 to 12; n is an integer from 0 to 12; and Y is hydrogen or methyl. Formulas (PG-1a), (PG-1b), or (PG-1c) can be selected appropriately depending on the manufacturing conditions of the low dielectric constant resin. For example, when producing a low dielectric constant resin film by commonly used photocuring, formula (PG-1a) with methyl Y is preferred in terms of high curability, solubility in organic solvents, and ease of handling. Furthermore, when forming internal substrates for IC chips with high heat generation, low dielectric interlayer insulating films, low dielectric adhesives, low dielectric underfill materials, etc., formula (PG-1b) is preferred. In addition, when forming diamines for forming polyimide films and low dielectric resins containing such diamines, which can be suitably used in radar and the like, formula (PG-1c) is preferred. End group R １ Linking group in the middle - (CH ２ ) ｎ - or - (CH２ ) ｍ Regarding the case of a single bond where n is 0, or an alkylene where n or m is an integer from 1 to 6, the molecular length is short, the melting point is high, the crystallinity is high, the melting point or the phase transition temperature from crystal to nematic phase is high, the thermal conductivity is high, the relative permittivity is low, and the dielectric loss tangent is small.

[0036] <Ring structure A: A １ A ２ , and A ３ > Ring structure A of compound (1) １ A ２ , and A ３ These are independently 1,4-cyclohexylene or 1,4-phenylene, and in the rings of 1,4-cyclohexylene and 1,4-phenylene, at least one hydrogen may be replaced by an alkyl group having 1 to 6 carbon atoms. Ring structure A of compound (1) １ A ２ , and A ３ Preferred examples include 1,4-cyclohexylene, 2-methyl-1,4-cyclohexylene, 3,5-dimethyl-1,4-cyclohexylene, 1,4-phenylene, 2-methyl-1,4-phenylene, 2,3-dimethyl-1,4-phenylene, 2,5-dimethyl-1,4-phenylene, and 2,6-dimethyl-1,4-phenylene. Even more preferred examples are 1,4-cyclohexylene, 3,5-dimethyl-1,4-cyclohexylene, 1,4-phenylene, 2-methyl-1,4-phenylene, and 2,5-dimethyl-1,4-phenylene.

[0037] The stereochemistry of 1,4-cyclohexylene or 3,5-dimethyl-1,4-cyclohexylene is preferred in the trans isomer over the cis isomer because it exhibits higher linearity and lower dielectric properties. 2-methyl-1,4-phenylene and 3-methyl-1,4-phenylene are structurally identical, so the latter is not used as an example. This rule also applies to the relationship between 2,5-dimethyl-1,4-phenylene and 3,6-dimethyl-1,4-phenylene, among others. When at least one ring in ring structure A is 1,4-phenylene or substituted 1,4-phenylene, the orientational order parameter and magnetic anisotropy are high. Also, when at least two rings are 1,4-phenylene or substituted 1,4-phenylene, the temperature range of the liquid crystal phase is wide and the transparency point is high. A preferred example of a atom in which at least one hydrogen atom on the 1,4-phenylene ring may be replaced by an alkyl group having 1 to 6 carbon atoms is methyl, which lowers the melting point and increases solubility. Furthermore, the relative permittivity is low because the molecular polarizability is small. In addition, dielectric loss is low because molecular motion is suppressed. When at least one ring is 1,4-cyclohexylene, the transparency point is high, the relative permittivity is very low, dielectric loss is low, and viscosity is low. When at least two rings are 1,4-cyclohexylene, the transparency point is high, the relative permittivity is very low, dielectric loss is low, and viscosity is low. Furthermore, when the ring structure of compound (1) is 1,4-cyclohexylene, 3,5-dimethyl-1,4-cyclohexylene, and 1,4-phenylene, it is preferable from a cost standpoint in the production of compound (1).

[0038] <Binding group Z: Z １ and Z ２ > Bonding group Z of compound (1) １ and Z ２ The atoms are independently single-bonded or alkylenes with 1 to 2 carbon atoms. Bonding group Z of compound (1) １ and Z ２ Preferred examples include single bonds or methylene. In the case of single bonds, the rigidity of the molecule increases, resulting in high liquid crystalline properties, low viscosity, and a small dielectric loss tangent. In the case of methylene, the molecular length increases, leading to a lower melting point and higher solubility in organic solvents.

[0039] p is an integer between 0 and 2. When p is 0, i.e., when compound (1) has two rings, the viscosity is low, and when p is 1 or greater, i.e., when it has three or more rings, the transparency point is high.

[0040] As described above, the ring structure A, the bonding group Z, and the terminal group R １ By appropriately selecting the type of compound, etc., a compound with the desired physical properties can be obtained. Specific examples of preferred compounds (1) include those represented by formulas (1-1) to (1-12).

[0041] In formulas (1-1) to (1-12), Z ２ A is an alkylene with a single bond or 1-2 carbon atoms; ３ is 1,4-cyclohexylene or 1,4-phenylene, where at least one hydrogen in the ring of 1,4-cyclohexylene and 1,4-phenylene may be replaced by an alkyl group having 1 to 6 carbon atoms; p is 1 or 2; X is an alkyl group having 1 to 6 carbon atoms; s is an integer from 0 to 4; m is an integer from 1 to 12; n is an integer from 0 to 12; Me is methyl; and in the formula, Z ２ A ３ If there are multiple s, p, or X, they may be the same or different, and if there are multiple s, m, or n, they may be the same or different.

[0042] A more preferred specific example of compound (1) is shown below. In formulas (1-1-1), (1-1-2), (1-3-1), (1-3-2), (1-5-1), (1-5-2), (1-7-1), (1-7-2), (1-9-1), (1-9-2), (1-11-1), and (1-11-2), Me is methyl; m is an integer from 1 to 12; n is an integer from 0 to 12; and any multiple m or n in a formula may be the same or different.

[0043] [Synthesis Method of Compound (1)] Compound (1) can be synthesized by combining known techniques in organic synthesis. Methods for introducing the desired terminal group, ring structure, linking group, and bonding group into the starting material are described, for example, in textbooks such as Houben-Wyle (Methods of Organic Chemistry, Georg Thieme Verlag, Stuttgart), Organic Syntheses (John Wily & Sons, Inc.), Organic Reactions (John Wily & Sons, Inc.), Comprehensive Organic Synthesis (Pergamon Press), and New Experimental Chemistry Series (Maruzen).

[0044] The method for introducing the binding group Z is explained in schemes 1 and 2 below. In these schemes, MSG １ and MSG ２ represents a monovalent organic group having at least one ring, and Hal represents a halogen. Multiple MSGs used in the scheme below １ (or MSG) ２ These compounds may be the same or different. Compounds (1A) to (1C) in the following scheme correspond to compound (1) above. These methods can be applied to the synthesis of optically active compound (1) and optically inert compound (1).

[0045] (Scheme 1) Compounds in which Z is a single bond As shown below, arylboric acid (S1) and a compound synthesized by known methods (S2) are reacted in the presence of an aqueous carbonate solution and a catalyst such as tetrakis(triphenylphosphine)palladium to produce MSG １ and MSG ２Compound (1A) can be synthesized in which a single bond is introduced between the two. This compound (1A) can also be synthesized by reacting compound (S3), which is synthesized by known methods, with n-butyllithium, then zinc chloride, and then further reacting it with compound (S2) in the presence of a catalyst such as dichlorobis(triphenylphosphine)palladium.

[0046]

[0047] (Scheme 2) Z is - (CH ２ ) ２ - The compound (1B) obtained as described above is hydrogenated in the presence of a catalyst such as palladium carbon to produce MSG. １ and MSG ２ Between - (CH ２ A compound (1C) having )2- can be synthesized.

[0048]

[0049] 2) Polymer (1) Compound (1) used in the present invention is a polymerizable group ((meth)acryloyloxy, oxyranyl, or maleimide residue, i.e., a terminal group R having 1H-pyrrole-2,5-dione-1-yl) １) is easily polymerized. The polymer (1) in the present invention is at least one polymer obtained by polymerizing compound (1). Specifically, the polymer (1) in the present invention is a homopolymer obtained by polymerizing one type of compound (1), a copolymer obtained by polymerizing two or more types of compound (1), and a copolymer obtained by polymerizing one or more types of compound (1) and one or more polymerizable compounds other than compound (1). In the composition (1) of the next section, the polymer (1) composed in combination with at least one other component may be an oligomer of compound (1). This oligomer means a low polymer in which the number of constituent units (degree of polymerization) of compound (1) that constitute the polymer (1) is small. Among oligomers, they may be called dimers, trimers, tetramers, etc., depending on the number of constituent units.

[0050] 3) Composition (1) The composition (1) in the present invention is a composition comprising at least one compound (1). That is, composition (1) may consist of two or more compounds (1), or it may consist of a combination of at least one compound (1) and at least one other component other than compound (1) which includes polymer (1). Such other at least one component is not particularly limited, but examples include polymer (1), polymerizable compounds other than compound (1) (hereinafter also referred to as "other polymerizable compounds"), polymerization initiators, organic solvents, nonpolymerizable liquid crystalline compounds, inorganic fillers and fibrous reinforcing agents. Preferred compositions (1) include compositions comprising at least one compound (1) and polymer (1), compositions comprising at least one compound (1) and other polymerizable compounds, and compositions comprising at least one compound (1), polymer (1) and other polymerizable compounds.

[0051] 4) The other polymerizable compound composition (1) may contain a polymerizable compound other than compound (1) (the other polymerizable compound). The polymerizable compound other than compound (1) is composed of at least one of the following polymerizable liquid crystalline compounds other than compound (1) (hereinafter also referred to as "the other polymerizable liquid crystalline compound") and at least one polymerizable non-liquid crystalline compound.

[0052] 4-1) The other polymerizable liquid crystalline compound composition (1) may contain at least one polymerizable liquid crystalline compound other than compound (1). From the viewpoints of the expression of the liquid crystal phase of the composition (1) which is a polymerizable liquid crystal composition and the compatibility with compound (1), organic solvents, etc., the compound represented by formula (M1), (M2) or (M3) (however, excluding compound (1)) is preferable as the polymerizable liquid crystalline compound.

[0053]

[0054] In formula (M1), (M2) and (M3), A Ｍ is independently any divalent group selected from 1,4-phenylene, 1,4-cyclohexylene, 1,4-cyclohexenylene, pyridine-2,5-diyl, 1,3-dioxane-2,5-diyl, naphthalene-2,6-diyl, or fluorene-2,7-diyl, and in the divalent group, at least one hydrogen may be replaced by fluorine, chlorine, cyano, hydroxy, formyl, trifluoroacetyl, difluoromethyl, trifluoromethyl, alkyl having 1 to 5 carbon atoms, alkoxy having 1 to 5 carbon atoms, alkoxycarbonyl having 2 to 5 carbon atoms, or alkanoyl having 2 to 5 carbon atoms; Z Ｍ is independently a single bond, -OCH ２ -, -CH ２ O -, -COO -, -OCO -, -COS -, -SCO -, -OCOO -, -CONH -, -NHCO -, -CF ２ O -, -OCF ２ -, -CH ２ CH ２ -, -CF ２ CF ２ -, -CH=CHCOO -, -OCOCH=CH -, -CH ２ CH ２COO−, −OCOCH ２ CH ２ −, −COOCH ２ CH ２ −, −CH ２ CH ２ OCO−, −CH=CH−, −N=CH−, −CH=N−, −N=C(CH ３ ), −C(CH ３ )=N−, −N=N−, −C≡C−, −CH=N−N=CH−, or −C(CH ３ )=N−N=C(CH ３ )−; X Ｍ is hydrogen, fluorine, chlorine, trifluoromethyl, trifluoromethoxy, cyano, alkyl having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, alkoxy having 1 to 20 carbon atoms, or alkoxycarbonyl having 2 to 20 carbon atoms; Y Ｍ is independently a single bond, −O−, −COO−, −OCO−, or −OCOO−; Q Ｍ is a single bond, −O−, −COO−, or −OCO−; q is an integer of 1 to 6; c and d are independently integers of 0 to 3, and satisfy the relationship of 1≦c + d≦6; a is an integer of 0 to 20; P ３ to P ５ are independently groups selected from the polymerizable groups represented by formulas (PG-1) to (PG-13).

[0055] 4-2) The polymerizable non-crystalline compound composition (1) may consist of at least one polymerizable non-crystalline compound. As such a polymerizable non-crystalline compound, compounds that do not reduce film-forming properties and mechanical strength are preferred. These polymerizable non-crystalline compounds are classified as compounds that do not have liquid crystalline properties. Examples of polymerizable non-crystalline compounds that do not have liquid crystalline properties include derivatives such as vinyl derivatives, styrene derivatives, (meth)acrylic acid derivatives, sorbic acid derivatives, fumaric acid derivatives, and itaconic acid derivatives, as well as oligomers of modified engineering plastics such as modified polyimide oligomers, modified maleimide oligomers, modified polyphenylene ether oligomers, modified polyphenylene sulfide oligomers, and modified polybutadiene elastomers, i.e., macromers meaning high molecular weight compounds having polymerizable functional groups. Preferred examples of these derivatives are shown below.

[0056] In the text, "(meth)acryloyloxy" means acryloyloxy or methacryloyloxy, "(meth)acrylate" means acrylate or methacrylate, and "(meth)acrylic acid" means acrylic acid or methacrylic acid.

[0057] Preferred vinyl derivatives include vinyl chloride, vinyl fluoride, vinyl acetate, vinyl pivalate, vinyl 2,2-dimethylbutanoate, vinyl 2,2-dimethylpentanoate, vinyl 2-methyl-2-butanoate, vinyl propionate, vinyl stearate, vinyl 2-ethyl-2-methylbutanoate, N-vinylacetamide, p-t-butylbenzoate, vinyl N,N-dimethylaminobenzoate, vinyl benzoate, ethyl vinyl ether, hydroxybutyl monovinyl ether, t-amyl vinyl ether, cyclohexanedimethanol methyl vinyl ether, α,β-vinylnaphthalene, methyl vinyl ketone, and isobutyl vinyl ketone.

[0058] Preferred styrene derivatives include styrene, o-chlorostyrene, chlorostyrene, p-chlorostyrene, o-chloromethylstyrene, chloromethylstyrene, p-chloromethylstyrene, and α-methylstyrene.

[0059] Preferred (meth)acrylic acid derivatives include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, phenyl (meth)acrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylol EO-added triacrylate, pentaerythritol triacrylate, tris(meth)acryloyloxyethyl phosphate, bisphenol A EO-added diacrylate, bisphenol A glycidyl diacrylate (trade name: "Viscoat 700" manufactured by Osaka Organic Chemical Industry Co., Ltd.), polyethylene glycol diacrylate dimethyl itaconate, and the like.

[0060] Preferred sorbic acid derivatives include sodium sorbate, potassium sorbate, lithium sorbate, 1-naphthylmethylammonium sorbate, benzylammonium sorbate, dodecylammonium sorbate, octadecylammonium sorbate, methyl sorbate, ethyl sorbate, propyl sorbate, isopropyl sorbate, butyl sorbate, t-butyl sorbate, hexyl sorbate, octyl sorbate, octadecyl sorbate, cyclopentyl sorbate, cyclohexyl sorbate, vinyl sorbate, allyl sorbate, and propagyl sorbate.

[0061] Preferred fumaric acid derivatives include dimethyl fumarate, diethyl fumarate, diisopropyl fumarate, dibutyl fumarate, dicyclopentyl fumarate, and dicyclohexyl fumarate.

[0062] Preferred itaconic acid derivatives include diethyl itaconate, dibutyl itaconate, and diisopropyl itaconate. In addition to these, many polymerizable non-liquid crystallinity compounds such as butadiene, isoprene, and maleimide can be used.

[0063] 5) The polymerization initiator composition (1) may also contain a polymerization initiator as a component. Depending on the curing method (polymerization method) of composition (1), the polymerization initiator may be a thermal radical polymerization initiator, a photo-radical polymerization initiator, a photo-cationic polymerization initiator, etc. When the polymerizable compound used in the present invention is composited with an inorganic filler to increase thermal conductivity, it is preferable to use a thermal radical polymerization initiator because the inorganic filler absorbs light. When the composite material with the inorganic filler is used as a thin film with a thickness of several μm, it is also possible to cure it by photopolymerization by increasing the amount of polymerization initiator or using a strong polymerization initiator.

[0064] Preferred thermal radical polymerization initiators include benzoyl peroxide, diisopropyl peroxydicarbonate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxypivalate, di-t-butyl peroxide (DTBPO), t-butyl peroxydiisobutyrate, lauroyl peroxide, dimethyl 2,2'-azobisisobutyrate (MAIB), azobisisobutyronitrile (AIBN), azobiscyclohexanecarbonilate (ACN), and dimethyl 2,2'-azobis(isobutyrate). Commercially available peroxide-based initiators include benzoyl peroxide from various manufacturers, as well as "Dicumyl Peroxide" from Tokyo Chemical Industries, Ltd., and "Permil D, Niper BMT, Perhexa 25Z" from NOF Corporation. Examples of azo polymerization initiators include AIBN, which is commercially available from various companies, as well as products from Fujifilm Wako Pure Chemical Industries, Ltd., such as "V-40, V-50, V-59, V-65, V-70, V-501, and V-601." Generally, azo polymerization initiators can be suitably used for both thermal radical polymerization and photoradical polymerization.

[0065] The photoradical polymerization initiator is not particularly limited and known ones can be used, including 4-methoxyphenyl-2,4-bis(trichloromethyl)triazine, 2-(4-butoxystyryl)-5-trichloromethyl-1,3,4-oxadiazole, 9-phenylacridine, 9,10-benzphenazine, benzophenone / Michlar's ketone mixture, hexaarylbiimidazole / mercaptobenzimidazole mixture, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, benzyldimethyl ketal, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,4-diethylxanthone / p-dimethylaminobenzoate methyl mixture, benzophenone / methyltriethanolamine mixture, and the like. Commercially available products include the "Darocure Series 1173, 4265" and the "Irgacure Series 184, 369, 500, 651, 784, 819, 907, 1300, 1700, 1800, 1850, 2959" manufactured by Ciba Specialty Chemicals (now BASF Japan Ltd).

[0066] The photocationic polymerization initiator is not particularly limited and known ones can be used, including commercially available products such as UCC's "Sylacure UVI-6990, 6974", ADEKA Corporation's "ADEKA Optomer SP-150, 152, 170, 172", Rhodia's "Photoinitiator 2074", Ciba Specialty Chemicals (now BASF Japan Ltd.)'s "Irgacure 250", and Midori Chemical Co., Ltd.'s "DTS-102".

[0067] Preferred initiators for anionic polymerization, coordination polymerization, and living polymerization include alkali metal alkyl compounds such as n-C4H9Li and t-C4H9Li-R3Al, aluminum compounds, and transition metal compounds.

[0068] 6) When the curing agent composition (1) contains a cyclic ether which is a cyclic compound having an ether linkage, such as compounds (1-5) to (1-8), it may also contain a curing agent as a component. Examples of preferred curing agents are shown below.

[0069] As amine-based curing agents, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, o-xylenediamine, m-xylenediamine, p-xylenediamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, diethylaminopropylamine, isophoronediamine, 1,3-bisaminomethylcyclohexane, bis(4-amino-3-methylcyclohexyl)methane, bis(4-aminocyclohexyl)methane, norbornenediamine, 1,2 Examples include -diaminocyclohexane, 3,9-dipropanamine-2,4,8,10-tetraoxaspiro[5.5]undecane, 4,4'-diaminodiphenylmethane, 4,4'-diamino-1,2-diphenylethane, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylsulfone, polyoxypropylenediamine, polyoxypropylenetriamine, polycyclohexylpolyamine, and N-aminoethylpiperazine.

[0070] Examples of acid anhydride-based curing agents include tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, methylcyclohexenetetracarboxylic dianhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, ethylene glycol bis-anhydrotrimelliterate, glycerin bis(anhydrotrimellitate) monoacetate, dodecenyl succinic anhydride, and chloride anhydride.

[0071] Examples of phenolic curing agents include phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, m-ethylphenol, p-ethylphenol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, o-isopropylphenol, p-tert-butylphenol, o-sec-butylphenol, p-octylphenol, 2,6-di-tert-butylphenol, resorcinol, 1-naphthol, 2-naphthol, bisphenol A, phenol novolac, xylylene novolac, and bisphenol A novolac. In addition to the above, curing agents described in Japanese Patent Publication No. 2004-256687 and Japanese Patent Publication No. 2002-226550 can also be used.

[0072] The active ester curing agent is not particularly limited and known products can be used. Examples of commercially available products include "EPICLON® HPC-8000-65T" manufactured by DIC Corporation as an active ester compound containing a dicyclopentadiene-type diphenol structure, "EXB-8150-65T" manufactured by DIC Corporation as an active ester compound containing a naphthalene structure, "DC808" manufactured by Mitsubishi Chemical Corporation as an active ester compound containing an acetylated phenol novolac, "YLH1026" manufactured by Mitsubishi Chemical Corporation as an active ester compound containing a benzoylated phenol novolac, "DC808" manufactured by Mitsubishi Chemical Corporation as an active ester curing agent that is an acetylated phenol novolac, and "YLH1026" manufactured by Mitsubishi Chemical Corporation as an active ester curing agent that is a benzoylated phenol novolac.

[0073] Furthermore, as curing accelerators, cycloamidine compounds such as 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), 1,5-diazabicyclo[4.3.0]-5-nonene, and 5,6-dibutylamino-1,8-diazabicyclo[5.4.0]-7-undecene; and to the cycloamidine compounds, maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, and 2,3-dimethoxy-5-methyl-1,4 Compounds having intramolecular polarization obtained by adding quinone compounds such as benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone, diazophenylmethane, and phenolic resins that have π bonds; tertiary amine compounds such as benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol, and 4-dimethylaminopyridine; derivatives of the tertiary amine compounds; 2-methylimidazole, 2-phenylimidazole Examples include imidazole compounds such as 2-phenyl-4-methylimidazole; derivatives of the imidazole compounds; organic phosphine compounds such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, tris(4-methylphenyl)phosphine, diphenylphosphine, and phenylphosphine; phosphorus compounds having intramolecular polarization obtained by adding compounds having π bonds such as maleic anhydride, the above quinone compounds, diazophenylmethane, and phenolic resins to the organic phosphine compounds; tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, and N-methylmorpholine tetraphenylborate; derivatives of the tetraphenylboron salts; and adducts of phosphine compounds such as triphenylphosphonium-triphenylborane and N-methylmorpholine tetraphenylphosphonium-tetraphenylborate with the tetraphenylboron salts.

[0074] 7) The organic solvent composition (1) may contain an organic solvent. The curing of composition (1) may be carried out in an organic solvent or without a solvent. For example, composition (1) containing an organic solvent may be applied to a substrate by a spin coating method or the like, and then the organic solvent may be removed before photocuring. Alternatively, after photocuring, post-treatment may be performed by heating to an appropriate temperature and thermal curing.

[0075] Preferred organic solvents include benzene, toluene, xylene, mesitylene, hexane, heptane, octane, nonane, decane, tetrahydrofuran (THF), methyl ethyl ketone (MEK), γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide, cyclohexane, methylcyclohexane, cyclopentanone, cyclohexanone, and 2-methoxy-1-methylethyl acetate (propylene glycol methyl ether acetate: PGMEA). These organic solvents may be used individually or in mixtures of two or more. There is little point in limiting the proportion of organic solvents used during curing; it should be determined on a case-by-case basis, taking into consideration curing efficiency, solvent cost, energy cost, etc.

[0076] The composition (1) of the present invention preferably contains 70% by weight or less of an organic solvent by total weight, and is particularly preferably a solvent-free composition. A solvent-free composition is a composition that can be prepared as a varnish that maintains fluidity at room temperature or exhibits high fluidity when melted without using an organic solvent. By using a composition containing 70% by weight or less of an organic solvent by total weight, or a solvent-free composition, the concentration of the cured product is increased, allowing the function of the cured product to be effectively expressed. The composition (1) before curing is in a liquid state and maintains fluidity at or near room temperature, and can be used as is as a solvent-free varnish or a varnish containing 70% by weight or less of an organic solvent by total weight by total weight. That is, it can be used as is for applications such as coating or bonding, and there is no need for a process to volatilize the solvent at high temperature. Examples of organic solvents that can be used here include acetone, methyl ethyl ketone, toluene, xylene, methyl isobutyl ketone, ethyl acetate, ethylene glycol monomethyl ether, N,N-dimethylformamide, methanol, and ethanol, which have relatively low toxicity from the viewpoint of environmental impact. Composition (1) of the present invention enables the formation of resins with high heat resistance and low dielectric constant in non-organic solvent systems, and can therefore provide insulating materials for various electronic components such as laminates for printed circuit boards, interlayer insulating materials for substrates, adhesive films, semiconductor encapsulants, and conductive adhesives.

[0077] 8) The non-polymerizable liquid crystalline compound composition (1) may also contain a liquid crystalline compound that does not have polymerizable groups. Examples of such non-polymerizable liquid crystalline compounds are listed in LiqCryst (LCI Publisher GmbH, Hamburg, Germany), a database of liquid crystalline compounds. By curing the composition (1) containing the non-polymerizable liquid crystalline compound, composite materials of the polymer of compound (1) and the liquid crystalline compound can be obtained. In such composite materials, for example, the non-polymerizable liquid crystalline compound is present in a polymer network such as a polymer-dispersed liquid crystal.

[0078] 9) Inorganic fillers and fibrous reinforcing agents Inorganic fillers can be added to composition (1) to improve thermal conductivity, mechanical strength, viscosity, etc. In this specification, inorganic fillers may be referred to as inorganic fillers. To suppress dielectric loss, silicon compounds such as spherical silica, crushed silica, hollow silica, and fumed silica, metal oxides such as magnesium oxide, zinc oxide, and titanium oxide, and metal salts such as potassium titanate may be used. Spherical silica, hollow silica, magnesium oxide, and potassium titanate are preferred, and hollow silica is more preferred. Fibrous reinforcing agents can be used as fibrous or whisker-shaped fillers to increase the strength of substrates and resin parts. Inorganic fibers such as glass cloth, low-dielectric glass cloth, carbon fiber, and carbon nanotubes, and inorganic whiskers such as silicate whiskers, alumina whiskers, magnesium oxide whiskers, zinc oxide whiskers, and aluminum nitride whiskers are preferred, and low-dielectric glass cloth, aluminum oxide whiskers, aluminum nitride whiskers, and carbon nanotubes are more preferred.

[0079] To increase mechanical strength, a larger amount of filler is preferable, but too much filler may prevent the resin from filling the gaps. Conversely, too much resin may not increase mechanical strength. Furthermore, increasing the filler tends to increase the dielectric constant and decrease the dielectric loss tangent, so it is preferable to determine the composition while maintaining a balance between these two factors. In addition to inorganic fibers, organic fibers can also be used as fibrous reinforcing agents. Examples of organic fibers with high mechanical strength include polyamide fibers, aramid fibers, poly(p-phenylenebenzobisoxazole) fibers, liquid crystalline polyester fibers, and cellulose nanofibers. Compared to inorganic fibers, they are lighter and therefore preferable for substrates in portable devices.

[0080] As fillers with high thermal conductivity, suitable fillers may include metal nitrides such as powdered aluminum nitride, boron nitride, and silicon nitride; carbides such as diamond, graphite, and silicon carbide; metal oxides such as magnesium oxide, aluminum oxide, zinc oxide, silicon oxide, titanium oxide, tin oxide, holmium oxide, and calcium oxide; metal hydroxides such as magnesium hydroxide and aluminum hydroxide; silicate compounds such as cordierite or mullite; and metal fillers such as gold, silver, copper, platinum, iron, tin, lead, nickel, aluminum, magnesium, tungsten, molybdenum, and stainless steel. Boron nitride and silicon oxide, which have low dielectric constants, are preferred, and hexagonal boron nitride (h-BN) is particularly preferred because it has a low dielectric constant and high thermal conductivity. Thermal conductivity and other properties increase with increasing amounts of inorganic filler, but generally, inorganic fillers have a larger relative permittivity and smaller dielectric loss tangent compared to resin components, so increasing the amount of filler increases the dielectric constant. Therefore, it is preferable to fill the required amount within a range that does not exceed the target dielectric constant. If heat resistance is not required, using cellulose nanofibers is preferable, although the dielectric constant will be slightly higher, due to their high thermal conductivity and lightweight properties.

[0081] Composition (1) of the present invention is highly transparent and low dielectric, and when used as a low refractive index optical material, the refractive index can be adjusted by adding powders such as hollow silica, spherical silica, titanium oxide, and zirconium oxide.

[0082] The filler can take various shapes, including spherical, amorphous, fibrous, whisker-like, tubular, and plate-like forms. The type, shape, size, and amount of filler can be appropriately selected according to the purpose. If the resulting polymer molded product requires insulation, the filler may be conductive, provided that the desired insulation, mechanical strength, relative permittivity, dielectric loss tangent, and dielectric loss are maintained.

[0083] The average particle size of spherical or irregularly shaped fillers is preferably 0.1 to 200 μm. More preferably, it is 1 to 100 μm. A particle size of 0.1 μm or more provides good thermal conductivity, while a particle size of 200 μm or less allows for increased filling density. Regarding fibrous fillers, while longer fiber lengths improve tensile strength, they may become difficult to knead or disperse, so selection is preferable depending on the application. When dispersed, the average particle size of fibrous fillers is preferably 0.01 to 200 μm. More preferably, it is 0.1 to 100 μm. A particle size of 0.01 μm or more provides good thermal conductivity, while a particle size of 200 μm or less allows for increased mechanical strength. The amount of filler is preferably such that the polymer molded article contains 20 to 95% by weight of filler after curing. More preferably, it is 50 to 95% by weight. A particle size of 20% by weight or more is preferable because it increases thermal conductivity. A particle size of 95% by weight or less is preferable because it prevents the polymer molded article from becoming brittle.

[0084] As fillers, commercially available products that have undergone surface treatments such as affinity treatment, easy adhesion treatment, dispersion treatment, and waterproofing treatment may be used as is, or the surface treatment agents may be removed from such commercially available products. Alternatively, untreated fillers may be treated with silane coupling agents, affinity agents, surface tension modifiers, settling inhibitors, coagulation inhibitors, etc., before use.

[0085] 10) Since the other additive compounds (1) and composition (1) have high polymerizability, stabilizers may be added to composition (1) to facilitate handling. Such stabilizers can be any known substances without limitation, including hydroquinone, 4-ethoxyphenol, and 3,5-di-t-butyl-4-hydroxytoluene (BHT). In applications where a low dielectric loss tangent (low tanδ) and a high glass transition temperature are required, it is preferable to add a crosslinking agent. The crosslinking agent is preferably one that chemically bonds with the polymerizable groups of compound (1) having polymerizable groups at both ends used in the present invention, forming a three-dimensional crosslink.

[0086] The composition (1) of the present invention may contain other resins that do not react with compound (1) used in the present invention in order to adjust the properties of the cured product. Examples include polyphenylene ether resin (PPE resin), polystyrene resin, polycarbonate resin, polyimide resin, polyamide resin, polyester resin, polybutadiene copolymer, polyvinyl acetal resin, natural rubber, synthetic rubber, synthetic elastomer, epoxy resins different from the liquid crystal skeleton of compound (1) used in the present invention, oxetane resin, acrylic resin, methacrylic resin, maleimide resin, oxazine resin, oxazoline resin, etc. Polyphenylene ether resin (PPE resin), polystyrene resin, and polycarbonate resin are preferred when dielectric properties are particularly important. There may be unreacted parts in these resins that react with compound (1) used in the present invention, but in that case a crosslinked structure will be formed, so an improvement in properties can be expected compared to when there is no reaction at all.

[0087] 11) Low dielectric constant resin Another embodiment of the present invention, the low dielectric constant resin, is a cured product of composition (1) and therefore has a low dielectric constant, as well as excellent thermal conductivity, heat resistance, rigidity, elasticity, moldability, chemical resistance, and dimensional stability.

[0088] 11-1) Selection of Polymerizable Groups The correlation between the relative permittivity and dielectric loss tangent of the cured product and the polymerizable group when the low dielectric constant resin-forming composition of the present invention is cured without the addition of an inorganic filler is as follows. When a polymerizable group represented by formula (PG-1a) is selected as the polymerizable group, there is no electron transfer or conjugation from the ring structure, and therefore the relative permittivity and dielectric loss tangent are excellent in the region of 10 GHz or higher, and especially in the region of 0.1 THz or higher, which is said to be used at 6 G. For example, although it depends on the substituents added to the liquid crystal skeleton, the length of the linker portion and the number of oxygen atoms, in the range of 1 GHz to 50 GHz, which can be measured with a cavity resonator that is currently widely used, the relative permittivity is in the range of 2.6 to 2.0 and the dielectric loss tangent is in the range of 0.01 to 0.001. Preferably, the relative permittivity is in the range of 2.4 to 2.0 and the dielectric loss tangent is in the range of 0.01 to 0.001, more preferably the relative permittivity is in the range of 2.2 to 2.0 and the dielectric loss tangent is in the range of 0.008 to 0.001, and even more preferably the relative permittivity is in the range of 2.2 to 2.0 and the dielectric loss tangent is in the range of 0.006 to 0.001, by designing the liquid crystal skeleton and linker portion molecularly. Furthermore, when selecting a polymerizable group represented by formula (PG-1b), the curing time can be shortened because it is more reactive than that represented by formula (PG-1a). For example, in the embodiments of the present invention, when polymerizing a compound having a polymerizable group represented by formula (PG-1a), if curing is attempted at 180°C or 200°C as is, if the molecular weight of the compound having a polymerizable group represented by formula (PG-1a) is small, it will evaporate before the reaction can occur. Therefore, it was necessary to react it at 130°C for 5 hours, 150°C for 5 hours, and 170°C for 5 hours, followed by further firing at 200°C for 2 hours and 220°C for 2 hours. In the case of formula (PG-1b), curing can be achieved, for example, by pre-curing at 150°C for 30 minutes and then fully curing at 220°C for 1 hour. However, conjugation and electron imbalance are likely to occur between the ring structure of formula (PG-1b) and the surrounding atoms, and the dielectric properties, especially in the high-frequency range, are slightly inferior to those of compounds with polymerizable groups represented by formula (PG-1a). In the range of 1 GHz to 50 GHz, the relative permittivity is in the range of 2.8 to 2.0 and the dielectric loss tangent is in the range of 0.02 to 0.001.Preferably, the relative permittivity is in the range of 2.8 to 2.0 and the dielectric loss tangent is in the range of 0.01 to 0.001, more preferably the relative permittivity is in the range of 2.6 to 2.0 and the dielectric loss tangent is in the range of 0.008 to 0.001, and even more preferably the relative permittivity is in the range of 2.5 to 2.0 and the dielectric loss tangent is in the range of 0.006 to 0.001, by designing the liquid crystal skeleton and linker portion of the molecule. It is also possible to form a resin with superior dielectric properties than polymerizing a single component, such as maleimide styryl resin, by using a compound having a maleimide residue. Furthermore, when short-time curing using photocuring or patterning is required, it is preferable to use a photopolymerization initiator in combination with a compound having a polymerizable group represented by formula (PG-1a), but by devising the photopolymerization initiator and curing catalyst, it is also possible to use a compound having a polymerizable group represented by formula (PG-1b) or formula (PG-1c).

[0089] 11-2) In the selection formula for the main skeleton (1), ring structure A １ A ２ and A ３ and the bonding group Z １ and Z ２ In the central part consisting of A １ A ２ and A ３ In the case of 1,4-cyclohexylene, there is no electron transfer or conjugation in the high-frequency band like in aromatic rings, so it exhibits excellent relative permittivity and dielectric loss tangent in the region of 10 GHz and above, and especially in the region of 0.1 THz and above, which is said to be used at 6 GHz. For example, although it depends on the substituents added to the skeleton, the length of the linker portion, and the number of oxygen atoms, in the range of 1 GHz to 50 GHz, which can be measured with currently widely used cavity resonators, the relative permittivity is in the range of 2.6 to 2.0 and the dielectric loss tangent is in the range of 0.01 to 0.001. Preferably, the relative permittivity is in the range of 2.4 to 2.0 and the dielectric loss tangent is in the range of 0.01 to 0.001, more preferably the relative permittivity is in the range of 2.2 to 2.0 and the dielectric loss tangent is in the range of 0.008 to 0.001, and even more preferably the skeleton and linker portion are molecularly designed so that the relative permittivity is in the range of 2.2 to 2.0 and the dielectric loss tangent is in the range of 0.006 to 0.001. １ A ２ and A ３In the case of 1,4-phenylene, the rigidity and crystallinity of the molecular chain are high, resulting in excellent thermal conductivity, heat resistance, and flame retardancy. Furthermore, by introducing side chains such as methyl to the phenylene ring, the affinity with solvents and other resins can be controlled. However, when heat dissipation is important, it is preferable to have no side chains, or if they are present, to arrange C1-C2 alkyl side chains symmetrically with respect to the axis of molecular vibration, such as in compounds having polymerizable groups represented by formula (1-5-2) or formula (1-7-2).

[0090] 11-3) When a molecularly oriented low-dielectric resin exhibits liquid crystalline properties, molecular orientation can be controlled by orientation treatment before curing. Relative permittivity and thermal conductivity exhibit anisotropy depending on the molecular orientation direction. When designing the dielectric constant and thermal properties of an electronic substrate, it becomes possible to design the substrate so that the area directly beneath the heat-generating IC has high thermal conductivity in the thickness direction, while other areas are oriented laterally to spread heat over a wide area, enabling more advanced material design. The orientation method can be controlled by the following methods. Methods for controlling the orientation of the mesogenic portion of liquid crystal molecules in a low-dielectric resin forming composition include treating the inorganic filler surface with a silane coupling agent or orientation agent that has orientation ability, and aligning the molecules using the self-orientation restricting force of the composition itself. These methods may be performed individually or in combination of two or more. The orientation states controlled by such orientation control methods include homogeneous, twisted, homeotropic, hybrid, bent, and spray orientation, which can be appropriately determined depending on the application and orientation control method. Furthermore, during film formation or molding, shear stress can be applied to the liquid crystal state before hardening to physically orient the material.

[0091] The orientation temperature is preferably in the range of room temperature to 250°C, more preferably room temperature to 200°C, and even more preferably room temperature to 180°C. The heat treatment time is preferably in the range of 5 seconds to 2 hours, more preferably 10 seconds to 60 minutes, and even more preferably 20 seconds to 30 minutes. If the heat treatment time is longer than the lower limit of the above range, the temperature of the layer made of composition (1) can be raised to a predetermined temperature, and if it is shorter than the upper limit of the above range, productivity is improved. Note that the above heat treatment conditions vary depending on the type and composition ratio of components used in composition (1), the presence and content of polymerization initiators, etc., so these are merely approximate ranges. In particular, if the temperature is higher than the polymerization start temperature of the polymerizable components used in composition (1), the resin will harden before orientation can occur, and a low dielectric constant resin with molecular chains oriented in a specific direction cannot be obtained.

[0092] Examples of curing methods (polymerization methods) for composition (1) include radical polymerization, anionic polymerization, cationic polymerization, and coordination polymerization of polymerizable groups (polymerizable components). However, to immobilize molecular arrangements or helical structures, thermal polymerization or photopolymerization using light or heat, such as electron beams, ultraviolet light, visible light, or infrared light (heat rays), is suitable. Thermal polymerization is preferably carried out in the presence of a radical polymerization initiator, and photopolymerization is preferably carried out in the presence of a photoradical polymerization initiator. For example, a polymer in which the arrangement of liquid crystal molecules is immobilized can be obtained by polymerization using irradiation with ultraviolet light or electron beams in the presence of a photoradical polymerization initiator. The resulting polymer may be a homopolymer, random copolymer, alternating copolymer, block copolymer, or graft copolymer, and can be appropriately selected depending on the application.

[0093] When fixing the orientation of composition (1) by photopolymerization, ultraviolet light or visible light is usually used. The wavelength of the light used for irradiation is preferably in the range of 150 to 500 nm, more preferably 250 to 450 nm, and even more preferably 300 to 400 nm. Examples of light sources for irradiation include low-pressure mercury lamps (germicidal lamps, fluorescent chemical lamps, black lights), high-pressure discharge lamps (high-pressure mercury lamps, metal halide lamps), and short-arc discharge lamps (ultra-high-pressure mercury lamps, xenon lamps, mercury xenon lamps), and ultraviolet light-emitting diodes. Among these, metal halide lamps, xenon lamps, ultraviolet light-emitting diodes, and high-pressure mercury lamps are preferred.

[0094] The wavelength range of the light source can be selected by installing a filter or the like between the light source and composition (1) to allow only a specific wavelength range to pass through. The amount of light emitted from the light source is preferably 2 to 5000 mJ / cm². 2 More preferably 10 to 3000 mJ / cm² 2 More preferably 100 to 2000 mJ / cm² 2 This is within the specified range. The temperature conditions during light irradiation are preferably set in the same way as the heat treatment temperature described above.

[0095] The conditions for fixing the orientation of composition (1) by thermal polymerization are as follows: the curing temperature is preferably in the range of room temperature to 350°C, more preferably room temperature to 250°C, and even more preferably 50°C to 200°C; and the curing time is preferably in the range of 5 seconds to 10 hours, more preferably 1 minute to 5 hours, and even more preferably 5 minutes to 1 hour. After curing, it is preferable to cool slowly in order to suppress stress strain, etc. Alternatively, reheating may be performed to alleviate strain, etc.

[0096] The cured product or composition in the curing process, whose orientation has been controlled as described above, may be further oriented in any direction by mechanical operations such as stretching. The isolated polymer (1) may be dissolved in an organic solvent to prepare a composition with other components, which may then be oriented and cured on an orientation-treated substrate and processed into a film or the like. In this case, two polymers may be mixed and processed, or multiple polymers may be laminated. Preferred organic solvents include N-methyl-2-pyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, N,N-dimethylacetamide dimethylacetal, tetrahydrofuran, chloroform, 1,4-dioxane, bis(methoxyethyl) ether, γ-butyrolactone, tetramethylurea, trifluoroacetic acid, trifluoroethyl acetate, hexafluoro-2-propanol, 2-methoxyethyl acetate, methyl ethyl ketone, cyclopentanone, and cyclohexanone. These may also be used in combination with small amounts of common organic solvents such as acetone, benzene, toluene, heptane, and methylene chloride.

[0097] When a highly linear, low-dielectric-constant resin-forming composition exhibits a liquid crystal phase in a very narrow range and has high crystallinity, it forms domains with axes aligned in a specific direction, resulting in higher thermal conductivity compared to polymerizable compounds such as bisphenol A structures. Furthermore, orientation and crystallinity can be controlled by slowly curing the material from an isotropic liquid state while a polymer sheet surface with aligned orientation directions or a crystalline resin filler serves as a core for crystal growth. However, excessively high crystallinity tends to reduce flexibility, so it is necessary to use a composition with appropriate crystalline properties.

[0098] 12) Low-dielectric-constant resin insulating film, low-dielectric-constant resin film, and low-dielectric-constant resin sheet The polymer molded articles of the present invention are molded articles of low-dielectric-constant resin, which are cured products of the low-dielectric-constant resin forming composition consisting of the above composition (1). In addition to being used as thin-film low-dielectric-constant resin insulating films, they can also be used as film-like, sheet-like, plate-like, fibrous, or three-dimensional shaped parts (insulating parts of connectors), or as coating agents, adhesives, or fillers. When used as thin-film-like, film-like, sheet-like, plate-like, fibrous, or three-dimensional shaped molded articles, the preferred shapes are films and thin films. Films and thin films are obtained by curing composition (1) applied to a substrate or release film, or sandwiched between flat plates such as a substrate or mold. They can also be obtained by applying composition (1) containing an organic solvent to an oriented substrate and removing the organic solvent. Furthermore, films can also be obtained by press molding the cured product. In this specification, the thickness of the sheet is 1 mm or more, the thickness of the film is 5 μm or more and less than 1 mm, preferably 10 to 500 μm, more preferably 20 to 300 μm, and the thickness of the thin film is less than 5 μm.

[0099] The following describes in detail a method for producing a film as a polymer molded article using composition (1) containing an organic solvent. First, composition (1) is applied to a release-treated substrate, and the organic solvent is dried off to form a coating layer with a uniform thickness. Examples of application methods include spin coating, roll coating, curtain coating, flow coating, print coating, microgravure coating, gravure coating, wire bar coating, dip coating, spray coating, and meniscus coating.

[0100] Organic solvents can be removed by drying in the air at room temperature, drying on a hot plate, drying in a drying oven, or by blowing warm or hot air. The conditions for removing organic solvents are not particularly limited; it is sufficient to dry the coating layer until the organic solvent is mostly removed and the coating layer loses its fluidity. Depending on the type and composition ratio of the compounds used in composition (1), the molecular orientation of the liquid crystal molecules in the coating layer may be completed during the drying process. In such cases, the coating layer that has gone through the drying process can be subjected to the polymerization process (curing process) without going through the heat treatment process described above. However, in order to make the orientation of the liquid crystal molecules in the coating layer more uniform, it is preferable to heat the coating layer that has gone through the drying process to the liquid crystal phase emergence temperature to orient it in the liquid crystal state, and then fix the orientation by photopolymerization or thermal polymerization treatment.

[0101] Furthermore, when composition (1) is used as a low dielectric constant resin insulating film, it is also preferable to perform orientation treatment on the substrate surface before coating. Orientation treatment methods include simply forming an orientation film on the substrate, rubbing the substrate with a rayon cloth after forming an orientation film on the substrate, rubbing the substrate directly with a rayon cloth, or obliquely depositing silicon oxide, or using a stretched film, photo-alignment film, or rubbing-free orientation with an ion beam. In some cases, a desired orientation state can be formed without treating the substrate surface. When forming homeotropic orientation, surface treatments such as rubbing are often not performed, but rubbing may be performed to achieve higher orientation.

[0102] The orientation film is not particularly limited as long as it can control the orientation of composition (1), and known orientation films can be used. For example, polyimide, polyamide, polyvinyl alcohol, alkylsilane, alkylamine, or lecithin-based orientation films are preferred. Silane coupling agents are also preferred when vertical orientation is required.

[0103] Any method can be used for the rubbing process described above. Typically, a rubbing cloth made of materials such as rayon, cotton, and polyamide is wrapped around a metal roll or the like, and the roll is rotated and moved while in contact with the substrate or alignment film, or the substrate is moved while the roll is fixed.

[0104] Furthermore, to obtain a more uniform orientation, an orientation control additive may be included in composition (1). Examples of such orientation control additives include imidazoline, quaternary ammonium salts, alkylamine oxides, polyamine derivatives, polyoxyethylene-polyoxypropylene condensates, polyethylene glycol and its esters, sodium lauryl sulfate, ammonium lauryl sulfate, lauryl sulfate amines, alkyl-substituted aromatic sulfonates, alkyl phosphates, aliphatic or aromatic sulfonic acid formalin condensates, laurylamidopropyl betaine, laurylaminoacetic acid betaine, polyethylene glycol fatty acid esters, polyoxyethylene alkylamines, perfluoroalkyl sulfonates, perfluoroalkyl carboxylates, perfluoroalkylethylene oxide adducts, perfluoroalkyltrimethylammonium salts, oligomers having perfluoroalkyl and hydrophilic groups, oligomers having perfluoroalkyl and lipophilic groups, urethanes having perfluoroalkyl, and organosilicon compounds having primary amino groups (alkoxysilane type, linear siloxane type, and three-dimensional condensation type silsesquioxane type organosilicon compounds).

[0105] Examples of the above-mentioned substrates include plastic film substrates and glass-reinforced resin substrates such as polyimide, polyamideimide, polyamide, polyetherimide, polyetheretherketone, polyetherketone, polyketone sulfide, polyethersulfone, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyacetal, polycarbonate, polyarylate, acrylic resin, polyvinyl alcohol, polypropylene, cellulose, triacetylcellulose or its partially saponified products, epoxy resin, phenolic resin, norbornene resin, as well as glass substrates such as alkali glass, borosilicate glass, and flint glass; metal substrates such as aluminum, iron, and copper; and inorganic substrates such as silicon.

[0106] The above-mentioned film substrate may be a uniaxially oriented film or a biaxially oriented film. The above-mentioned film substrate may be subjected to a surface treatment such as saponification, corona treatment, or plasma treatment in advance. A protective layer that is not affected by the organic solvent contained in the above-mentioned composition (1) may be formed on these film substrates. Examples of materials that can be used as a protective layer include polyvinyl alcohol. Furthermore, an anchor coat layer may be formed to improve the adhesion between the protective layer and the substrate. Such an anchor coat layer may be made of either inorganic or organic material, as long as it improves the adhesion between the protective layer and the substrate.

[0107] 13) Low-dielectric-constant resin components and electronic equipment The low-dielectric-constant resin forming composition of the present invention can be used as low-dielectric-constant resin components such as low-dielectric-constant resin insulating films, low-dielectric-constant resin films, and low-dielectric-constant resin sheets. Furthermore, it is useful for various electronic equipment applications such as low-dielectric-constant resin substrates, low-dielectric-constant resin coatings, low-dielectric-constant resin adhesives, and low-dielectric-constant resin molded products.

[0108] [Manufacturing Method] The following describes in detail a method for manufacturing a composition for forming low dielectric constant resins, and a method for manufacturing low dielectric constant resin parts from said composition.

[0109] The low dielectric constant resin-forming composition of the present invention can be used as a liquid resin raw material in the temperature range in which the liquid crystal phase or isotropic phase is exhibited, or it can be dissolved in an organic solvent and used as a solution. The low dielectric constant resin-forming composition is prepared by adding compound (1), which is a polymerizable liquid crystalline compound (1), an organic solvent, an inorganic filler, and the various additives mentioned above as needed, and stirring and degassing with a stirrer until the composition is uniform. For example, using a rotation-orbit mixer, stirring at a rotation speed of 2000 rpm for 10 minutes, followed by degassing at a rotation speed of 2200 rpm for 10 minutes. In addition to a rotation-orbit mixer, dispersion can be performed using a stirring motor, a swivel, a three-roll mill, a ball mill, a rotation-orbit mill, a planetary mill, a bead mill, a jet mill, etc.

[0110] For the coating method, a wet coating method is preferable to uniformly coat the low dielectric constant resin-forming composition described above. Among wet coating methods, the spin coating method is preferable when producing small quantities of low dielectric constant resin parts, as it is simple and allows for homogeneous film formation. When productivity is a priority, gravure coating, die coating, bar coating, reverse coating, roll coating, slit coating, dipping, spray coating, kiss coating, reverse kiss coating, air knife coating, curtain coating, inkjet, flexographic printing, screen printing, and rod coating methods are preferred. The wet coating method can be appropriately selected from these methods depending on the required film thickness, viscosity, curing conditions, etc.

[0111] When manufacturing sheets, a cast molding method is used in which the composition is coated onto a release-treated substrate using the method described above and then peeled off. When manufacturing structures, resin molding methods such as press molding, injection molding, and various 3D printer molding methods (extrusion deposition) can be used, using molds as needed. After molding, the mold can be removed and the material cured, or it can be cured while still in the mold, or in the case of molding methods that do not use molds, the molded body can be cured as is.

[0112] The composition (1) containing a polymerizable liquid crystalline compound (1) in which two single bonds or alkylene linkers are linked to the core structure of the molecule used in the present invention is a low dielectric constant resin-forming composition that exhibits high heat resistance and dielectric properties of low dielectric constant and low dielectric loss tangent in the high frequency range after curing, and is a composition that can be prepared in a varnish-like state using no solvent or a small amount of organic solvent. Furthermore, in addition to the above properties, it is a low dielectric constant resin-forming composition that exhibits high transparency or high heat dissipation. The cured product obtained by curing the composition of the present invention has high heat dissipation and transparency in addition to low dielectric properties, and has excellent properties in at least one of the following: chemical stability, heat resistance, hardness and mechanical strength, making it suitable for various applications such as low dielectric circuit boards, low dielectric antenna substrates, low dielectric coatings, low dielectric adhesives, next-generation communication equipment and radar in the high frequency range.

[0113] The present invention will be further described in detail by examples (including examples of the preparation of compounds, compositions, polymers, low dielectric constant resins, etc.). The present invention is not limited by these examples.

[0114] [Synthesis Example of Compound (1)] Compound (1) was synthesized according to the procedure shown in the synthesis examples, such as Synthesis Example 1. Unless otherwise specified, the reaction was carried out under a nitrogen atmosphere. The synthesized compound was identified by methods such as NMR analysis. The properties of Compound (1), the composition, the polymer, and the low dielectric constant resin were measured by the following methods.

[0115] <NMR Analysis> For the measurement, a JNM-ECZR manufactured by JEOL Ltd. was used. １ In 1H-NMR measurements, the sample is placed in CDCl ３ The samples were dissolved in deuterated solvents, and measurements were performed at room temperature under conditions of 500 MHz and 16 integration cycles. Tetramethylsilane was used as an internal standard. １９ In F-NMR measurements, CFCl ３ The experiment was conducted using the internal standard and under the condition of 32 integration cycles. In the description of nuclear magnetic resonance spectra, s means singlet, d means doublet, t means triplet, q means quartet, quin means quintet, sex means sextet, m means multiplet, and br means broad.

[0116] <Gas Chromatography Analysis> A GC-2014 gas chromatograph manufactured by Shimadzu Corporation was used for the measurement. The column used was a DB-1 capillary column (length 30 m or 15 m, inner diameter 0.25 mm, film thickness 0.25 μm) manufactured by Agilent Technologies Inc. (now Keysight Technologies, Inc.). Nitrogen (1 ml / min) was used as the carrier gas. The temperature of the sample vaporization chamber was set to 300°C, and the temperature of the detector (FID) section was set to 300°C. The sample was dissolved in a suitable solvent such as acetone to prepare a 1% by weight solution, and 1 μl of the obtained solution was injected into the sample vaporization chamber. A GC Solution system manufactured by Shimadzu Corporation was used as the recorder.

[0117] <HPLC Analysis> For the measurement, a Prominence (LC-20AD; SPD-20A) manufactured by Shimadzu Corporation was used. The column used was a YMC-Pack ODS-A (length 150 mm, inner diameter 4.6 mm, particle size 5 μm) manufactured by YMC Corporation. The eluent was a mixture of methanol / pure water or acetonitrile / pure water as appropriate. As a detector, a UV detector, RI detector, CORONA detector, etc. were used as appropriate. When a UV detector was used, the detection wavelength was set to 210-254 nm. The sample was dissolved in methanol or acetonitrile to prepare a 0.1 wt% solution, and 1 μL of this solution was introduced into the sample chamber. A C-R7Aplus manufactured by Shimadzu Corporation was used as the recorder.

[0118] <Ultraviolet-Vis Spectroscopic Analysis> A PharmaSpec UV-1700 manufactured by Shimadzu Corporation was used for the measurements. The detection wavelength was set from 190 nm to 700 nm. The sample was dissolved in acetonitrile to prepare a 0.01 mmol / L solution, which was then placed in a quartz cell (optical path length 1 cm) for measurement.

[0119] <Measurement Samples> When measuring the transition temperature (transparency point, melting point, polymerization initiation temperature, etc.), and, if the compound has a liquid crystal phase, the phase structure and transition temperature, the compound itself was used as the sample.

[0120] (1) Transition Temperature (°C) A high-sensitivity differential scanning calorimeter, X-DSC7000, manufactured by Hitachi High-Tech Science Corporation (formerly SII Nanotechnology Co., Ltd.), was used for measurement. The sample was heated and cooled at a rate of 3 to 5°C / min, and the transition temperature was determined by extrapolating the starting point of the endothermic or exothermic peak associated with the phase change of the sample. The melting point and polymerization start temperature of the compound were also measured using this instrument. When a compound has a liquid crystal phase, the temperature at which it transitions from solid to a liquid crystal phase such as the smectic phase or nematic phase is sometimes abbreviated as the "lower limit temperature of the liquid crystal phase." The temperature at which a compound transitions from crystal to liquid is sometimes abbreviated as the "transparency point."

[0121] Crystals were represented by C. When different types of crystals could be distinguished, they were represented as C1, C2, etc. When a liquid crystal phase appeared, the smectic phase was represented by S and the nematic phase by N. Within the smectic phase, when smectic A, smectic B, smectic C, or smectic F phases could be distinguished, they were represented as SA, SB, SC, or SF, respectively. Liquids (isotropic phases) were represented by I. Transition temperatures were expressed, for example, as "C 50.0 N 100.0 I". This indicates that the transition temperature from the crystal to the nematic phase is 50.0°C, and the transition temperature from the nematic phase to the liquid is 100.0°C.

[0122] (2) If the phase structure compound has a liquid crystal phase, the sample was placed on the hot plate of a melting point measuring device equipped with a polarizing microscope (Mettler Toledo FP-52 hot stage). The phase state and its changes were observed with a polarizing microscope while the sample was heated at a rate of 3°C / min to identify the type of phase.

[0123] [Synthesis Example 1] Synthesis of compound (S01: compound (1-5-1) when n is 3)

[0124] The starting material compound (S01-a) can be synthesized by known methods.

[0125] (Stage 1) Under a nitrogen atmosphere, 4,4'-bis(dimethoxymethyl)-1,1'-bi(cyclohexane) (S01-a) (100.0 g, 318.0 mmol) and tetrabutylammonium bromide (TBAB) (22.6 g, 70.0 mmol) were dissolved in toluene (500 mL), to which formic acid (200 mL, 5.30 mol) was added and the mixture was stirred at room temperature for 4 hours. The reaction mixture was poured into distilled water and extracted with toluene (1000 mL). The organic layer was washed once with saturated sodium bicarbonate solution and three times with distilled water, and then concentrated under reduced pressure at 40°C to obtain a concentrate. In a separate reaction vessel, under a nitrogen atmosphere, a solution of 2-(1,3-dioxan-2-yl)ethyltriphenylphosphonium bromide (321.3 g, 702.6 mmol) in tetrahydrofuran (THF) (900 ml) was cooled to below -40°C, and tert-butoxypotassium (78.7 g, 702.6 mmol) was added and the mixture was stirred for 2 hours. Then, a solution of the concentrate obtained in the previous reaction in THF (200 ml) was slowly added dropwise and the mixture was stirred for 12 hours. The reaction mixture was poured into ice water and extracted with toluene (2000 mL), washed three times with saturated brine, and the organic layer was concentrated under reduced pressure at 40°C. The resulting residue was dissolved in n-heptane at 70°C, insoluble matter was filtered off, and the residue was concentrated under reduced pressure. The resulting residue was isolated by silica gel column chromatography (solvent: toluene / ethyl acetate = 6 / 1 (volume ratio)) to obtain compound (S01-b) (110.0 g, 262.8 mmol).

[0126] (Stage 2) Compound (S01-b) (100.0 g, 238 mmol), palladium-carbon catalyst (5% by weight, 50% by weight water content): manufactured by N.E. Chemcat Co., Ltd.; 20.0 g), and THF (1200 ml) were placed in a reactor and stirred for 3 days under a hydrogen atmosphere. The catalyst was filtered off from the reaction mixture, toluene was added and washed with pure water, and concentrated under reduced pressure at 40°C. The obtained residue was isolated by silica gel column chromatography (solvent: toluene / ethyl acetate = 9 / 1 (volume ratio)), and compound (S01-c) (22.0 g, 52.1 mmol) was obtained by recrystallization filtration using Solmix A-11 (product name of Nippon Alcohol Sales Co., Ltd., 300 ml).

[0127] (Stage 3) Under a nitrogen atmosphere, formic acid (56 ml, 1.22 mol) was added to a toluene (140 mL) solution of compound (S01-c) (14.0 g, 33.1 mmol) and tetrabutylammonium bromide (TBAB) (2.14 g, 6.63 mmol), and the mixture was stirred at room temperature for 24 hours. The reaction mixture was poured into distilled water and extracted with toluene (200 mL). The combined organic layers were washed twice with saturated sodium bicarbonate solution, twice with distilled water, and once with saturated brine. The organic layers were then concentrated under reduced pressure at 40°C to obtain a concentrate. In a separate reaction vessel, under a nitrogen atmosphere, a THF (100 ml) solution of methyltriphenylphosphonium bromide (26.0 g, 72.9 mmol) was cooled to below -40°C, and tert-butoxypotassium (8.18 g, 72.9 mmol) was added and the mixture was stirred for 2 hours. A solution of the concentrate obtained in the previous reaction in THF (20 ml) was slowly added dropwise, and the mixture was stirred for 12 hours. The reaction mixture was poured into pure water and extracted with toluene (200 mL). After washing twice with pure water and once with saturated brine, the organic layer was concentrated under reduced pressure at 40°C. The resulting residue was isolated by silica gel column chromatography (solvent: n-heptane), and the compound (S01-d) (5.58 g, 18.4 mmol) was obtained by recrystallization filtration using ethanol.

[0128] (Stage 4) Under a nitrogen atmosphere, a solution of compound (S01-d) (3.30 g, 10.9 mmol) in dichloromethane (40 mL) was gradually added with 65% metachloroperbenzoic acid (mCPBA) (8.69 g, 32.7 mmol) under ice cooling, and the mixture was stirred for 12 hours while returning to room temperature. The reaction mixture was poured into a saturated sodium thiosulfate aqueous solution and extracted four times with dichloromethane (50 ml). The combined organic layer was washed three times with a saturated sodium thiosulfate aqueous solution, once with pure water, and once with saturated brine, and then the organic layer was concentrated under reduced pressure at 40°C. The resulting residue was purified by silica gel column chromatography (solvent: heptane / ethyl acetate = 4 / 1 (volume ratio)) and recrystallized by filtration using ethanol to obtain compound (S01) (2.90 g, 8.67 mmol).

[0129] The transition temperature of this compound (S01) was C 46.0 Sm 135.0 I (°C). １The H-NMR signal was as follows: δ (ppm; CDCl) ３ ): 2.92-2.89 (m, 2H), 2.75-2.74 (dd, 2H), 2.47-2.46 (dd, 2H), 1.76-1.68 (m, 8H), 1.53-1.40 (m, 8H), 1.25-1.10 (m, 6H), 1.00-0.81 (m, 10H).

[0130] [Synthesis Example 2] Synthesis of compound (S02: compound (1-5-1) when n is 0)

[0131]

[0132] (First stage) Starting with compound (S01-a), the same procedure as in the first stage of Synthesis Example 1 was carried out, except that methyltriphenylphosphonium chloride was used instead of 2-(1,3-dioxan-2-yl)ethyltriphenylphosphonium bromide, to obtain compound (S02-a) (20.0 g, 91.7 mmol).

[0133] (Second stage) Compound (S02) (13.7 g, 55.0 mmol) was obtained by using compound (S02-a) as a starting material and performing the same procedure as in the fourth stage of Synthesis Example 1.

[0134] The transition temperature of this compound (S02) was C 61.2 I (°C). １ The H-NMR signal was as follows: δ (ppm; CDCl) ３ ): 2.72-2.67 (m, 4H), 2.53-2.51 (dd, 2H), 1.97-1.93 (m, 2H), 1.77-1.70 (m, 6H), 1.15-0.96 (m, 12H).

[0135] [Synthesis Example 3] Synthesis of compound (S03: compound (1-5-1) when n is 2)

[0136] Compound (S03) (12.5 g, 40.8 mmol) was obtained by following the same procedure as in Synthesis Example 1, except that compound (S01-a) was used as the starting material and 2-(1,3-dioxan-2-yl)methyltriphenylphosphonium bromide was used instead of 2-(1,3-dioxan-2-yl)ethyltriphenylphosphonium bromide.

[0137] The transition temperature of this compound (S03) was C 42.7 Sm 118.1 I (°C). １ The H-NMR signal was as follows: δ (ppm; CDCl) ３ ): 2.91-2.87 (m, 2H), 2.75-2.74 (dd, 2H), 2.47-2.45 (dd, 2H), 1.78-1.69 (m, 8H ), 1.56-1.51 (m, 4H), 1.39-1.25 (m, 4H), 1.22-1.13 (m, 2H), 1.03-0.83 (m, 10H).

[0138] [Synthesis Example 4] Synthesis of compound (S04: compound (1-1-1) where m is 4)

[0139]

[0140] (Stage 1) Under a nitrogen atmosphere, formic acid (26 ml, 678 mmol) was added to a toluene (40 mL) solution of compound (S01-c) (8.0 g, 18.9 mmol) and tetrabutylammonium bromide (TBAB) (2.44 g, 7.57 mmol), and the mixture was stirred at room temperature for 24 hours. The reaction mixture was poured into distilled water and extracted with toluene (200 mL). The combined organic layers were washed twice with saturated sodium bicarbonate solution, twice with distilled water, and once with saturated brine. The organic layers were then concentrated under reduced pressure at 40°C to obtain a concentrate. In a separate reaction vessel, THF (80 ml) was cooled to below 0°C, and lithium aluminum hydride (0.50 g, 13.3 mmol) was added in small amounts. Then, a THF (20 ml) solution of the concentrate obtained in the previous reaction was added dropwise, and the mixture was stirred for 12 hours. The reaction mixture was cooled to ice, and distilled water and 15% by weight sodium hydroxide aqueous solution were added dropwise, and the mixture was stirred for 30 minutes. After filtering out insoluble matter from the reaction mixture, the organic layer was concentrated under reduced pressure at 40°C. Ethyl acetate (200 mL) was added to the resulting residue, and the organic layer was washed once with pure water and saturated brine. The organic layer was then concentrated under reduced pressure at 40°C. The resulting residue was recrystallized and filtered using n-heptane to obtain compound (S04-a) (3.0 g, 9.66 mmol).

[0141] (Second stage) Under a nitrogen atmosphere, methacrylic acid (1.83 g, 21.3 mmol) was added to a solution of compound (S04-a) (3.0 g, 9.66 mmol) in dichloromethane (30 mL) and stirred under ice cooling. Dimethylaminopyridine (0.43 g, 1.93 mmol) and dicyclohexylcarbodiimide (4.58 g, 22.2 mmol) were added in small amounts at 5°C or below, and the mixture was stirred for 14 hours while returning to room temperature. The mixture was filtered, and the organic layer was washed three times with saturated brine. The organic layer was then concentrated under reduced pressure at 40°C. The obtained residue was isolated by silica gel column chromatography (solvent: n-heptane / ethyl acetate = 9 / 1 (volume ratio)), and compound (S04) (1.76 g, 3.94 mmol) was obtained by recrystallization filtration using n-heptane.

[0142] The transition temperature of this compound (S04) was C 73.1 I (°C), and the polymerization initiation temperature was 129°C. １ The H-NMR signal was as follows: δ (ppm; CDCl) ３): 6.10-6.09 (dq, 2H), 5.55-5.54 (dq, 2H), 4.15-4.12 (t, 6H), 1.95-1.94 (s, 6H) , 1.75-1.62 (m, 12H), 1.40-1.34 (m, 4H), 1.22-1.10 (m, 6H), 1.02-0.81 (m, 10H).

[0143] [Synthesis Example 5] Synthesis of compound (S05: compound (1-1-1) where m is 3)

[0144]

[0145] Compound (S05-a) can be obtained by performing the same procedure as in the first and second steps of Synthesis Example 1, except that 2-(1,3-dioxan-2-yl)methyltriphenylphosphonium bromide is used instead of 2-(1,3-dioxan-2-yl)ethyltriphenylphosphonium bromide. Compound (S05) (10.1 g, 23.9 mmol) was obtained by performing the same procedure as in Synthesis Example 4, except that compound (S05-a) is used instead of compound (S01-c) as the starting material.

[0146] The transition temperature of this compound (S05) was C 20.8 I (°C), and the polymerization initiation temperature was 190.2°C. １ The H-NMR signal was as follows: δ (ppm; CDCl) ３ ): 6.05-6.02 (dq, 2H), 5.53-5.50 (dq, 2H), 4.15-4.12 (t, 6H), 1.93-1.91 (s, 6H ), 1.75-1.62 (m, 12H), 1.40-1.34 (m, 4H), 1.22-1.10 (m, 4H), 1.02-0.81 (m, 8H).

[0147] [Synthesis Example 6] Synthesis of compound (S06: compound (1-9-1) when n is 4)

[0148]

[0149] (Stage 1) Under a nitrogen atmosphere, a 48% aqueous solution of hydrogen bromide of compound (S01-d) obtained in Synthesis Example 1 is stirred at 25°C for 3 hours. The reaction mixture is poured into pure water, dichloromethane is added for extraction, and the mixture is washed twice with aqueous sodium thiosulfate and twice with pure water. The organic layer is then concentrated under reduced pressure at 40°C. The residue obtained from reduced pressure concentration is isolated by silica gel column chromatography to obtain compound (S06-a).

[0150] (Second stage) Under a nitrogen atmosphere, the compound (S06-a) obtained in the previous stage and a solution of sodium cyanide dimethyl sulfoxide (DMSO) are heated and stirred at 60°C for 3 hours. The reaction mixture is filtered to separate the precipitate, which is then extracted with toluene and washed three times with pure water. The organic layer is then concentrated under reduced pressure at 40°C. The residue obtained from the reduced-pressure concentration is isolated by silica gel column chromatography to obtain compound (S06-b).

[0151] (Third stage) Under a nitrogen atmosphere, the THF solution of compound (S06-b) obtained in the previous stage is slowly added dropwise to the tetrahydrofuran (THF) solution of lithium aluminum hydride (LAH) at 20°C, and the mixture is stirred for 5 hours. Ethyl acetate and (2N) aqueous sodium hydroxide solution are added dropwise to the reaction mixture, and the reaction mixture is filtered to remove insoluble matter. After washing three times with pure water, the organic layer is concentrated under reduced pressure at 40°C. The residue obtained from reduced pressure concentration is isolated by silica gel column chromatography (solvent: methanol / dichloromethane) to obtain compound (S06-c).

[0152] (Stage 4) Under a nitrogen atmosphere, the dichloromethane solution of compound (S06-c) obtained in the previous stage is slowly added at room temperature to the dichloromethane solution of maleic anhydride, and the mixture is stirred for 3 hours. The reaction mixture is then filtered to obtain precipitated crystals. In a separate reaction vessel, the mixture of the obtained crystals, sodium acetate, and acetic anhydride is heated and stirred at 100°C for 3 hours under a nitrogen atmosphere. The reaction mixture is poured into pure water and extracted with ethyl acetate, washed twice with sodium bicarbonate solution and twice with pure water, and then the organic layer is concentrated under reduced pressure at 40°C. The residue obtained from the reduced-pressure concentration is isolated by silica gel column chromatography to obtain compound (S06).

[0153] [Evaluation of Dielectric Properties (Relative Permittivity and Dielectric Loss Tangent)] [Example 1] <Preparation of Sample for Dielectric Properties (Relative Permittivity and Dielectric Loss Tangent) Measurement> 0.335 g of polymerizable compound (S01) as compound (1) and 0.212 g of diaminodiphenylethane (DDE) (manufactured by JNC Corporation) as a curing agent were weighed out and crushed in an alumina mortar until smooth, then mixed to obtain a mixed powder. A simple 80 mm square mold was formed in the center of a 150 mm square, 50 μm thick polyimide film (manufactured by Toray DuPont, Ltd., Kapton®) using a 12 mm wide, 50 μm thick heat-resistant polyimide adhesive tape as shown in Figure 1, and the obtained mixed powder was scattered near the center using a spatula. The film with this mixed powder was further sandwiched between 0.3 mm thick PTFE sheets and set in a small heated press manufactured by Imoto Seisakusho Co., Ltd., and the vacuum was evacuated until the vacuum gauge was maxed out. After reaching a vacuum, the temperature of the hot plate was raised to 120°C, then the pressure was increased to 10 MPa, and the temperature was raised to 200°C. During the process, the pressure was repeatedly increased and decreased every 20°C increase to perform a degassing operation. After reaching 200°C, a final degassing operation was performed, and the material was cured for 1 hour while maintaining the pressure and temperature. After natural cooling to below 80°C, the sample was removed, and an 80 mm square two-layer film (the polyimide film and the cured film) from the inside of the heat-resistant polyimide adhesive tape was cut out using a utility knife to prepare the sample for dielectric property measurement.

[0154] <Evaluation of Dielectric Properties (Relative Permittivity and Dielectric Loss Tangent)> Using cavity resonators (TE mode for 10 GHz, 28 GHz, and 40 GHz) manufactured by AET, INC., connected to a vector network analyzer (MS46522B-043, manufactured by Anritsu Corporation), the shift and attenuation of the resonant frequency of the sample for dielectric property measurement were measured, and the relative permittivity (D) was calculated using software from the same company. ｋ ) and dielectric loss tangent (D ｆThe dielectric properties of the material were determined. Since the film thickness greatly affects the measurement accuracy, the total thickness of the prepared sample was measured at five points using a Mitutoyo Digital Micrometer, and the average value was used in the calculation. To minimize the influence of moisture content in the sample during measurement, the sample was left undisturbed in a laboratory with the air conditioner set to 23°C (relative humidity remained at approximately 65% ​​RH on the day of measurement) from the previous night, and measurements began the following afternoon. Due to the large film thickness, the sample may curl due to hardening shrinkage, but it was pressed flat so that it could be inserted into the resonator during measurement. Cracks may also occur during this process, but if there are no gaps, this has almost no effect on the resonance method, so the measurement was continued as is.

[0155] Since these measurements represent the results for two layers—the polyimide film and the cured film—a polyimide film with the same history under heat and humidity was prepared simultaneously with sample preparation. The measurements of this polyimide film were used as the dielectric properties of the first layer, and the dielectric properties of only the cured film, including the relative permittivity and dielectric loss tangent, were determined using the company's spreadsheet for two-layer film calculations.

[0156] [Example 2] The dielectric properties were evaluated in the same manner as in Example 1, except that polymerizable compound (S02) was used as compound (1). The results are presented in Example 2.

[0157] [Example 3] The dielectric properties were evaluated in the same manner as in Example 1, except that polymerizable compound (S03) was used as compound (1). The results are presented in Example 3.

[0158] [Reference Example 1] Using a polymerizable compound synthesized in the same manner as described in International Publication No. 2022 / 092063 (ref. 01), a sample was prepared in the same manner as in Example 1, and its dielectric properties were evaluated. The results are presented as Reference Example 1.

[0159] [Comparative Example 1] Samples were prepared in the same manner as in Example 2, except that the following bisphenol F type epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name jER® 807) was used as the polymerizable compound, and the dielectric properties were evaluated. The results are presented as Comparative Example 1.

[0160] The relative permittivity of Examples 1-3, Reference Example 1, and Comparative Example 1 is summarized in Table 1-1, and the dielectric loss tangent is summarized in Table 1-2.

[0161]

[0162] A comparison of Examples 1-3, which use amine-based curing agents, and Reference Example 1 shows that when the atom adjacent to the cyclohexane ring is oxygen, and when the atom is carbon (including the case of a single bond), Examples 1-3 have lower relative permittivity and dielectric loss tangent. This is thought to be because the high electronegativity of the oxygen atom attracts electrons from surrounding atoms, slightly increasing the polarity of the molecular chain, and consequently slightly increasing the relative permittivity. These results, along with Comparative Example 1, also show that the polymerizable liquid crystalline compound (1) used in the present invention has significantly better dielectric properties compared to commercially available epoxy compounds.

[0163] On the other hand, a comparison of Examples 1 to 3 shows that among the compounds (1-5-1), the dielectric loss tangent is lowest when n is 0. This is thought to be because there are fewer oxygen atoms and, due to the absence of alkylene chains, the molecular chains become more rigid, suppressing molecular vibrations when high frequency is applied, resulting in less loss. Conversely, when alkylene chains are present, it can be seen that the relative permittivity is lowest and the dielectric properties are better when the alkylene chains are longer. This is thought to be because, in the case of polymers cured from epoxy compounds and diamines, the polarity of the polymerized portion is highest, and the longer the alkylene chains, the less oxygen there is per unit length of the entire polymer chain.

[0164] Regarding thermal conductivity, results described in International Publication No. 2022 / 092063 show that longer alkylene portions result in higher thermal conductivity. Therefore, when a certain degree of low elasticity is required, thermal conductivity is also necessary, and low dielectric properties are important, a polymerizable liquid crystalline compound having an alkylene chain like in Example 1 is preferred. When low elasticity is not required for small, thin parts and dielectric properties are important, a structure like in Example 2 is preferred. Furthermore, there is a concern that the adhesion to oxide fillers will decrease due to the reduction of oxygen atoms, but this can be resolved by using commercially available silane coupling materials and curing accelerators that improve adhesion to inorganic materials.

[0165] [Example 4] When epoxy resin is used in semiconductor chips themselves, amine-based curing agents have been avoided, and phenol novolac-based curing agents have been used. However, due to their low dielectric properties, active ester-based curing agents are being investigated. Similar to Example 1, 0.335 g of polymerizable compound (S01) as compound (1) and 0.991 g of active ester-based curing agent (DIC Corporation product name, EPICLON® HPC-8000-65T) as the curing agent were weighed into aluminum cups and mixed with a spatula until no unevenness was visible to obtain a mixture. HPC-8000-65T contains 65% by weight of toluene, and if the temperature is raised to cure it as is, it will foam, so to evaporate the toluene, it was dried in a vacuum oven set to 60°C for 24 hours. The mixture in the aluminum cup was placed on a hot plate and heated to 120°C. Once the solid components had softened into a paste, 0.5% by weight (4.0 mg) of 4-dimethylaminopyridine (DMAP) (manufactured by Tokyo Chemical Industry Co., Ltd.) was added as a curing accelerator and quickly mixed. Since this paste would solidify at room temperature, it was applied to the inside of the frame of the polyimide film used in Example 1 using a spatula before it solidified. The polyimide film with this solidified mixture was sandwiched between a 0.3 mm thick PTFE sheet and a 2 mm thick aluminum plate on the outside, and set in a small heating press manufactured by Imoto Seisakusho Co., Ltd., and evacuated until the vacuum gauge was maxed out. After reaching a vacuum, the temperature of the hot plate was raised to 80°C and dried for 1 hour. After confirming that the foaming had subsided, the temperature was raised to 130°C to soften the resin, then it was crushed at 10 MPa, and a degassing operation was performed. After degassing, the sample was pressurized to 20 MPa, the temperature was raised to 200°C, and the sample was cured for 2 hours while maintaining the pressure and temperature. After natural cooling to 80°C, the sample was removed, and an 80 mm square two-layer film from the inside of the polyimide tape was cut out using a utility knife to prepare the sample for dielectric property measurement.

[0166] <Evaluation Method for Dielectric Properties (Relative Permittivity and Dielectric Loss Tangent)> Using cavity resonators (TE mode 10GHz, 28GHz, and 40GHz) manufactured by AET, INC., connected to a vector network analyzer (MS46522B-043, manufactured by Anritsu Corporation), the shift and attenuation of the resonance frequency of the dielectric constant measurement sample were measured, and the dielectric properties of relative permittivity and dielectric loss tangent (tanδ) were determined using software manufactured by AET, INC. In this case, since the film thickness greatly affects the measurement accuracy, the total thickness of the prepared sample was measured at five points using a Mitutoyo Digital Micrometer, and the average value was used in the calculation. To minimize the effect of moisture content in the sample during measurement, the sample was left in a desiccator set to a relative humidity of 10% RH the night before, and on the measurement day, the sample was left to stand for more than 60 minutes before measurement in a laboratory at a temperature of 23°C and a relative humidity of 48% RH before measurement began. Due to the large film thickness, the sample may curl due to curing shrinkage, but it was flattened and measured so that it could be inserted into the resonator. Cracks may also occur during this process, but if there are no gaps, this has little effect on the resonance method, so the measurement was continued. Since these measurements represent the results of two layers, the polyimide film and the cured film, a polyimide film that had been heat-treated at 200°C for 1 hour was prepared at the same time as sample preparation, and the dielectric properties of only the cured film, such as the relative permittivity and dielectric loss tangent, were determined using the company's spreadsheet for two-layer film calculations.

[0167] [Example 5] The dielectric properties were evaluated in the same manner as in Example 4, except that a polymerizable compound (S02) was used as compound (1). The results are presented in Example 5.

[0168] [Reference Example 2] Samples were prepared in the same manner as in Example 4, except that (ref. 01) was used as the polymerizable compound, and the dielectric properties were evaluated. The results are presented as Reference Example 2.

[0169] [Comparative Example 2] Samples were prepared in the same manner as in Example 4, except that the following bisphenol F type epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name jER® 807) was used as the polymerizable compound, and the dielectric properties were evaluated. The results are presented as Comparative Example 2.

[0170] The relative permittivity of Examples 4-5, Reference Example 2, and Comparative Example 2 is shown in Table 2-1, and the dielectric loss tangent is shown in Table 2-2.

[0171]

[0172] <Method for Evaluating Moisture Content> After measuring the dielectric properties of the samples prepared in Examples 4 and 5, Reference Example 2, and Comparative Example 2, the samples were bent, and the resin portion consisting of the cured film was peeled off from the polyimide film substrate from the cracked area. 0.5 g of the obtained pieces of cured film were collected, placed in an aluminum cup, and left to stand for more than 72 hours in a room at 23°C and 65% RH relative humidity to absorb moisture from the atmosphere. The moisture content of only the resin portion consisting of the cured film was obtained from the pieces using a moisture meter (Shimadzu Corporation product name, MOC63u) in AUTO mode. No changes were observed in the color or shape of the samples before and after the evaluation of moisture content. The results are shown in Table 3.

[0173]

[0174] A comparison of Examples 4-5, which use an active ester-based curing agent, and Reference Example 2 shows that when the atom adjacent to the cyclohexane ring is carbon (not an oxygen atom), Examples 4-5, where the adjacent atom is carbon, have lower dielectric constant and dielectric loss tangent than when the adjacent atom is oxygen (including the case of a single bond). This is thought to be because the high electronegativity of the oxygen atom attracts electrons from surrounding atoms, slightly increasing the polarity of the molecular chain, and consequently slightly increasing the dielectric constant. From these results and Comparative Example 2, it can be seen that the polymerizable liquid crystalline compound (1) used in the present invention has significantly better dielectric properties compared to commercially available epoxy compounds.

[0175] On the other hand, a comparison of Examples 4-5 shows that, among the compounds (1-5-1), the dielectric constant is low when n is 0, except at 28 GHz. This is thought to be because the low number of oxygen atoms and the absence of alkylene chains make the molecular chains rigid, suppressing molecular vibrations when high frequencies are applied, resulting in less loss. Conversely, when alkylene chains are present, the dielectric loss tangent is low, indicating good dielectric properties. This is thought to be because, in the case of polymers cured from epoxy compounds and active ester-based curing agents, the polarity of the polymerized portion is highest, and the longer the alkylene chain, the less oxygen there is per unit length of the entire polymer chain.

[0176] Regarding thermal conductivity, results described in International Publication No. 2022 / 092063 show that longer alkylene portions result in higher thermal conductivity. Therefore, when low elasticity, high thermal conductivity, and low dielectric properties are important, a polymerizable liquid crystalline compound having an alkylene chain like in Example 4 is preferred. When low elasticity is not required for small, thin parts and dielectric properties are the only consideration, a structure like in Example 5 is preferred. Furthermore, the moisture content behaves almost the same as the relative permittivity. Therefore, polymerizable liquid crystalline compounds used in the present invention are effective in obtaining cured resins with low moisture content.

[0177] While epoxy compounds are widely used as thermosetting resins for semiconductor components and the like, the use of radical-reactive resins such as methacrylic resins and maleimide resins is expanding for low-dielectric substrates and low-dielectric insulating films. Therefore, in order to confirm the effect of reducing oxygen atoms in polymerizable liquid crystalline compounds, the above-mentioned compounds (S04) to (S06) were synthesized for methacrylic resins and maleimide resins, and their properties were evaluated as follows.

[0178] [Example 6] <Preparation of sample for measuring dielectric properties (relative permittivity and dielectric loss tangent)> 0.6 g of polymerizable compound (S04) as compound (1) and 0.6 g of powder of polyphenylene ether oligomer (mPPE: manufactured by SABIC, trade name: Noryl SA9000 resin) with methacrylate introduced at both ends as polymerizable compound were placed in a 20 mL glass vial, and 2.8 g of toluene was added and dissolved at 80°C. After dissolution, this solution was slowly cooled in an oven, and 0.012 g of NOF Corporation's trade name: Perloyl L was added as a polymerization initiator using a plastic spatula so that it amounted to 2% by weight of the resin-forming component, and mixed to obtain a solution of a low dielectric constant resin-forming composition. This solution was placed in a vacuum dryer and the solvent was evaporated for 15 hours to obtain a solid resin raw material. This solid resin raw material was crushed in a mortar and pestle, and 0.6 g of the obtained powder was dispersed on the polyimide film used in Example 1 and set in a heated press.

[0179] After exhausting, a two-layer film measuring 8 cm square was fabricated in the same manner as in Example 1, except that the curing time was set to 1 hour, and its dielectric properties were evaluated. The obtained cured film is transparent and can be used in applications requiring light transmission, and patterning by photolithography is possible if the polymerization initiator is changed to a photoradical generating type.

[0180] [Example 7] Samples were prepared in the same manner as in Example 6, except that a polymerizable compound (S05) was used as compound (1), and the dielectric properties were evaluated. The results are presented in Example 7.

[0181] [Reference Example 3] As a polymerizable compound, (ref. 02) was synthesized using the method described in International Publication No. 2022 / 092063, in which the carbon atom adjacent to the cyclohexane ring of compound (S04) was replaced with an oxygen atom. Samples were prepared in the same manner as in Example 6, except that (ref. 02) was used instead of the polymerizable compound (S04), and the dielectric properties were evaluated. The results are presented as Reference Example 3.

[0182] The relative permittivity of Examples 6-7 and Reference Example 3 is shown in Table 4-1, and the dielectric loss tangent is shown in Table 4-2.

[0183]

[0184] For the samples whose dielectric properties were evaluated in Examples 6 and 7 and Reference Example 3, in which SA9000 was used as the polymerizable compound for the second component, the moisture content was evaluated in the same manner as in Example 4, and the color of the samples was observed visually. The results are shown in Table 4-3.

[0185] Tables 4-1, 4-2, and 4-3 show that compound (1) used in the present invention has lower dielectric constant and dielectric loss tangent compared to conventional polymerizable liquid crystalline compounds, demonstrating a significant effect in reducing oxygen atoms. Furthermore, longer alkylene moieties result in lower dielectric constant, while shorter alkylene moieties result in lower dielectric loss tangent. The trend in dielectric constant is the same as that seen in compounds with epoxy groups, suggesting the same cause. Therefore, it is desirable to adjust the length of the alkylene moiety depending on the desired physical properties.

[0186] Furthermore, the cured products of compound (S04) alone and compound (S05) alone showed less coloration compared to the cured product of (ref. 02) alone, exhibiting only a slight pale yellow tint, and were almost transparent. On the other hand, the cured product of (ref. 02) was transparent with a pale orange tint. Therefore, it was found that compound (1) used in the present invention is more suitable for optical applications. When compounded with mPPE, there is coloration due to mPPE, but the dielectric loss tangent and film-forming properties are superior when compounded with mPPE, so it is desirable to determine the type and amount of polymerizable compound of the second component depending on the application.

[0187] [Evaluation of Thermal Conductivity of High Heat Dissipation Inorganic Filler Composite Material] <Preparation of Samples for Thermal Conductivity Measurement and Evaluation of Thermal Conductivity> [Example 8] In applications where heat dissipation is required, it is conceivable to use a composite material of the polymerizable liquid crystalline compound used in the present invention and a high heat dissipation inorganic filler. Therefore, the heat dissipation was evaluated by using the thermal conductivity measured after compounding a polymerizable liquid crystalline compound (1) used in a low dielectric constant resin forming composition and boron nitride, an inorganic filler, in a volume ratio of 50:50 so as to maximize the influence of the resin component.

[0188] As compound (1), 0.44 g of polymerizable compound (S04) and 0.80 g of boron nitride powder (manufactured by Momentive Technologies Japan, trade name: PolarTherm PTX-25) as an inorganic filler were mixed in a glass screw-top bottle, taking care not to break the secondary particles of the boron nitride powder as much as possible. A sheet with a thickness of approximately 200 μm was prepared using the same method as for the sample used for measuring dielectric properties (relative permittivity and dielectric loss tangent). The sample size did not spread to completely fill the inside of a simple mold measuring 8 cm × 8 cm × 200 μm, but the outer shape of the sample was disregarded as the focus was on thickness. A homogeneous and flat area was selected from this sheet, and a 25 mm diameter disc (for measuring thermal diffusivity in the planar direction) and a 10 mm × 10 mm square (for measuring thermal diffusivity in the thickness direction) were cut out using a design knife. The thickness of 200 μm was achieved by layering four 50 μm thick heat-resistant polyimide adhesive tapes. The pressure during pressing was set to 3 MPa to prevent the boron nitride powder aggregates from breaking. Compound (S04), compound (S05) used in Example 9, and (ref. 02) used in Reference Example 4 are methacrylate compounds and self-polymerize and solidify at around 180°C without the addition of a polymerization initiator.

[0189] Using the remaining portion of the sample after cutting out the sample for thermal diffusivity measurement, the specific heat capacity (using a Hitachi High-Tech DSC200 thermal analyzer and specific heat capacity analysis option software) and specific gravity (using a Shimadzu ATX124R analytical balance and SMK-501 specific gravity measurement kit) were determined. These values ​​were then multiplied by the thermal diffusivity obtained using a Netch Japan LFA467 thermal diffusivity measuring instrument and its accompanying software to calculate the thermal conductivity in the planar and thickness directions (thermal conductivity = thermal diffusivity × specific gravity (density) × specific heat capacity).

[0190] [Example 9] Samples were prepared and evaluated in the same manner as in Example 8, except that a polymerizable compound (S05) was used as compound (1). The results are presented as Example 9.

[0191] [Reference Example 4] Samples were prepared and evaluated in the same manner as in Example 8, except that (ref. 02) was used as the polymerizable compound. The results are presented as Reference Example 4.

[0192] [Comparative Example 3] A sample was prepared and evaluated in the same manner as in Example 8, except that a mixed powder of the bisphenol F type epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name jER® 807) and diaminodiphenylmethane (DDM) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) used in Comparative Example 2 was used as the polymerizable compound. The results are presented as Comparative Example 3. As a comparative material with the examples, it cannot be said that the comparison is under the same conditions because the polymerizable groups are different, but since epoxy resin is more common as a thermal conductive material, this composition was designated as Comparative Example 3.

[0193] The results for Examples 8-9, Reference Example 4, and Comparative Example 3 are shown in Table 5.

[0194] Table 5 shows that, in comparison with compound (1) used in the present invention and compound (ref. 02) in which the atom adjacent to the cyclohexane ring is oxygen, the thermal conductivity characteristics are almost the same. Furthermore, when compared with commercially available epoxy resins, it can be seen that compound (1) used in the present invention has a higher thermal conductivity, similar to the results shown in International Publication No. 2022 / 092063, and similar to the case when conventional polymerizable liquid crystalline compounds are used. Therefore, it can be seen that compound (1) used in the present invention has superior dielectric properties and equivalent heat dissipation performance compared to conventional polymerizable liquid crystalline compounds in which the atom adjacent to the benzene ring or cyclohexane ring is oxygen.

[0195] The low dielectric constant resin-forming composition of the present invention can be used as various electronic components, such as electronic substrates for high-frequency devices, semiconductor package components, and high-frequency antenna components, where low dielectric loss is required. In particular, it can be suitably used around semiconductor components that generate a lot of heat and require heat dissipation. It can also be used as a heat dissipation component in low-frequency devices where low dielectric loss is not required. Furthermore, the various electronic components obtained using the low dielectric constant resin-forming composition of the present invention are useful for various electronic device applications of the present invention.

[0196] 11. Polyimide film with release agent (150mm x 150mm x 0.05mm) 12. Heat-resistant polyimide adhesive tape (80mm x 12mm x 0.05mm)

Claims

1. A composition containing a liquid crystalline compound having polymerizable groups at both ends represented by formula (1), wherein the relative permittivity of the cured product at 10 GHz when the composition is cured without adding an inorganic filler is lower than 3.0, and the composition is for forming a low dielectric constant resin. In formula (1), Z １ and Z ２ are each independently a single bond or an alkylene having 1 to 2 carbon atoms; A １ , A ２ , and A ３ are each independently 1,4-cyclohexylene or 1,4-phenylene, and in the rings of 1,4-cyclohexylene and 1,4-phenylene, at least one hydrogen may be replaced by an alkyl having 1 to 6 carbon atoms; R １ａ and R １ｂ are each independently a group selected from the polymerizable groups represented by the following formulas (PG-1a), (PG-1b) and (PG-1c); p is an integer of 0 to 2; in the formula, when there are a plurality of Z ２ or A ３ , they may be the same or different. In formulas (PG-1a), (PG-1b) and (PG-1c), m is an integer of 1 to 12, n is an integer of 0 to 12, and Y is hydrogen or methyl.

2. In the compound represented by formula (1), A １ A ２ , and A ３ The low dielectric constant resin-forming composition according to claim 1, wherein the component is 1,4-cyclohexylene, and at least one hydrogen atom in the 1,4-cyclohexylene ring may be replaced by an alkyl group having 1 to 6 carbon atoms.

3. The low dielectric constant resin-forming composition according to claim 1 or 2, wherein the melting point of the liquid crystalline compound represented by formula (1) is 200°C or less, or the transition temperature from the nematic phase to the liquid is 200°C or less.

4. A low dielectric constant resin-forming composition according to claim 1 or 3, comprising at least one selected from liquid crystalline compounds having polymerizable groups at both ends, represented by formulas (1-1) to (1-4). In formulas (1-1) to (1-4), Z ２ A is an alkylene with a single bond or 1-2 carbon atoms; ３ is 1,4-cyclohexylene or 1,4-phenylene, where at least one hydrogen in the rings of 1,4-cyclohexylene and 1,4-phenylene may be replaced by an alkyl group having 1 to 6 carbon atoms; p is 1 or 2; X is an alkyl group having 1 to 6 carbon atoms; s is an integer from 0 to 4; m is an integer from 1 to 12; Me is methyl; and in the formula, Z ２ A ３ If there are multiple s or m, they may be the same or different, and if there are multiple s or m, they may be the same or different.

5. A low dielectric constant resin-forming composition according to claim 1 or 3, comprising at least one selected from liquid crystalline compounds having polymerizable groups at both ends, represented by formulas (1-5) to (1-8). In formulas (1-5) to (1-8), Z ２ A is an alkylene with a single bond or 1-2 carbon atoms; ３ is 1,4-cyclohexylene or 1,4-phenylene, where at least one hydrogen in the rings of 1,4-cyclohexylene and 1,4-phenylene may be replaced by an alkyl group having 1 to 6 carbon atoms; p is 1 or 2; X is an alkyl group having 1 to 6 carbon atoms; s is an integer from 0 to 4; n is an integer from 0 to 12; and in the formula, Z ２ A ３ If there are multiple s, p, or X, they may be the same or different, and if there are multiple s or n, they may be the same or different.

6. A low dielectric constant resin-forming composition according to claim 1 or 3, comprising at least one selected from liquid crystalline compounds having polymerizable groups at both ends, represented by formulas (1-9) to (1-12). In formulas (1-9) to (1-12), Z ２ A is an alkylene with a single bond or 1-2 carbon atoms; ３ is 1,4-cyclohexylene or 1,4-phenylene, where at least one hydrogen in the rings of 1,4-cyclohexylene and 1,4-phenylene may be replaced by an alkyl group having 1 to 6 carbon atoms; p is 1 or 2; X is an alkyl group having 1 to 6 carbon atoms; s is an integer from 0 to 4; n is an integer from 0 to 12; and in the formula, Z ２ A ３ If there are multiple s, p, or X, they may be the same or different, and if there are multiple s or n, they may be the same or different.

7. A low dielectric constant resin-forming composition according to any one of claims 1, 3, and 4, comprising at least one selected from liquid crystalline compounds having polymerizable groups at both ends, represented by formulas (1-1-1), (1-1-2), (1-3-1), and (1-3-2). In formulas (1-1-1), (1-1-2), (1-3-1), and (1-3-2), Me is methyl, m is an integer from 1 to 12, and the multiple m in a formula may be the same or different.

8. A low dielectric constant resin-forming composition according to any one of claims 1, 3, and 5, comprising at least one selected from liquid crystalline compounds having polymerizable groups at both ends, represented by formulas (1-5-1), (1-5-2), (1-7-1), and (1-7-2). In formulas (1-5-1), (1-5-2), (1-7-1), and (1-7-2), Me is methyl, and n is an integer from 0 to 12, and the multiple n in a formula may be the same or different.

9. A low dielectric constant resin-forming composition according to any one of claims 1, 3, and 6, comprising at least one selected from liquid crystalline compounds having polymerizable groups at both ends, represented by formulas (1-9-1), (1-9-2), (1-11-1), and (1-11-2). In formulas (1-9-1), (1-9-2), (1-11-1), and (1-11-2), Me is methyl, n is an integer from 0 to 12, and the multiple n in a formula may be the same or different.

10. The low dielectric constant resin-forming composition according to claim 1, comprising at least one selected from liquid crystalline compounds having polymerizable groups at both ends, represented by formula (1-1-1) in claim 7 and formula (1-5-1) in claim 8.

11. A low dielectric constant resin-forming composition according to claim 1, comprising at least one selected from (A) and (B) below: (A) A polymer of a liquid crystalline compound having polymerizable groups at both ends represented by formula (1); (B) A polymerizable compound other than a liquid crystalline compound having polymerizable groups at both ends represented by formula (1).

12. A composition for forming a low dielectric constant resin according to any one of claims 1 to 11, comprising a non-polymerizable liquid crystalline compound.

13. A low dielectric constant resin forming composition according to any one of claims 1 to 12, comprising an inorganic filler, wherein the thermal conductivity of the cured product obtained by curing the composition is 1 W / m·K or more.

14. A low dielectric constant resin forming composition according to any one of claims 1 to 13, comprising an inorganic filler which is a nitride filler, wherein the thermal conductivity of the cured product obtained by curing the composition is 10 W / m·K or more.

15. The low dielectric constant resin-forming composition according to claim 13, wherein the inorganic filler is at least one selected from the group consisting of silicon oxide compounds of spherical silica, pulverized silica, hollow silica and fumed silica, metal nitrides of aluminum nitride, boron nitride and silicon nitride, diamond, graphite, silicon carbide, and metal oxides of magnesium oxide, aluminum oxide, zinc oxide, titanium oxide, tin oxide and calcium oxide.

16. A composition for forming a low dielectric constant resin according to any one of claims 1 to 15, comprising a fibrous reinforcing agent.

17. The low dielectric constant resin-forming composition according to claim 16, wherein the fibrous reinforcing agent is at least one selected from the group consisting of glass cloth, low dielectric glass cloth, carbon fiber, carbon nanotube, polyamide fiber, aramid fiber, poly(p-phenylenebenzobisoxazole) fiber, liquid crystalline polyester fiber, cellulose nanofiber, silicate whisker, alumina whisker, magnesium oxide whisker, zinc oxide whisker, and aluminum nitride whisker.

18. A low dielectric constant resin insulating film which is a polymer molded article obtained by curing a low dielectric constant resin forming composition according to any one of claims 1 to 17 with heat or ultraviolet light.

19. A low dielectric constant resin film or low dielectric constant resin sheet, which is a polymer molded article obtained by curing a low dielectric constant resin-forming composition according to any one of claims 1 to 17 with heat or ultraviolet light.

20. A low dielectric constant resin part which is a polymer molded article obtained by curing a low dielectric constant resin forming composition according to any one of claims 1 to 17 with heat or ultraviolet light.

21. An electronic device using a polymer molded article obtained by curing a low dielectric constant resin-forming composition according to any one of claims 1 to 17 with heat or ultraviolet light.

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