Composition for forming low dielectric loss tangent resin, low dielectric loss tangent resin component, and electronic device using same

Abstract

A purpose of the present invention is to provide a composition for forming a low dielectric loss tangent resin, which, after cured, has high heat resistance as well as a low dielectric constant and low dielectric loss tangent in a high-frequency region in terms of dielectric properties, wherein the composition for forming a low dielectric loss tangent resin can be prepared in a varnish form in the absence of any solvent or in the presence of a small amount of an organic solvent. Another purpose of the present invention is to provide a composition for forming a low dielectric loss tangent resin, which has high transparency or high heat dissipation properties in addition to the above characteristics.　The present invention provides a composition for forming a low dielectric loss tangent resin, the composition being a curable resin composition that contains a compound (1) having a laterally substituted core ring structure, is capable of retaining flowability in a temperature range centered at room temperature, can be prepared in a varnish form in the absence of any solvent or in the presence of a small amount of an organic solvent, is formable in solution processing, has high heat resistance as well as a low dielectric constant and low dielectric loss tangent in a high-frequency region after cured, and also has high heat dissipation properties.

Description

Composition for forming low dielectric loss tangent resin, low dielectric loss tangent resin part, and electronic device using the same

[0001] The present invention relates to a composition for forming a low dielectric loss tangent resin using a polymerizable liquid crystal compound that can be treated in the same way as conventional epoxy resins, enabling the production of low dielectric loss tangent resins used in electronic components and electronic substrates that handle high frequencies for 5G and 6G using conventional production equipment and processes, and that can also improve the thermal conductivity of the cured product, as well as to a low dielectric loss tangent resin part and electronic device that use this composition.

[0002] In recent years, with the shift to 5G and even beyond 5G and 6G in communication devices, the frequency of electrical signals on electronic boards and the frequency of radio waves transmitted and received by antennas have become higher, resulting in problems with signal loss in signal processing circuit boards and antenna boards. Therefore, there is a demand for resin materials used in boards with lower dielectric constants and lower dielectric dissipation factors, and resins such as liquid crystal polymers (LCPs), polyphenylene ethers (PPEs), cycloolefin polymers (COPs), and fluororesins (PTFEs) are beginning to be used in place of conventional polyimides and epoxy resins. Low-dielectric substrates 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 demand for the development of materials with even lower dielectric constants. (Non-Patent Document 1)

[0003] As resin materials for electronics applications, epoxy resins and oxetane resins are widely used for sealants, insulating coating agents, insulating sheets, etc., as they are thermosetting and have strong adhesion to other resins, inorganic fillers, semiconductors, etc. However, epoxy resins tend to have higher relative permittivity and dielectric loss tangent than other resins, and efforts are being made to improve epoxy compounds to address this issue (Patent Documents 1 to 3).

[0004] On the other hand, as the signal processing volume increases, the amount of heat generated by semiconductor chips used for data processing also increases, making it necessary to improve the thermal conductivity of the resin portion to dissipate that heat. One method for increasing the thermal conductivity of resin is to liquid crystallize monomers before curing (Patent Document 4). By reducing the dielectric constant and dielectric loss tangent of polymerizable liquid crystal compounds (PLCs) created using this technology, it is possible to form resins that have low dielectric properties and also high thermal conductivity (Patent Document 5). When using a method to improve thermal conductivity using inorganic fillers, the thermal conductivity increases as the inorganic filler content increases. However, if the inorganic filler has low affinity with the inorganic filler, not only is the inorganic filler unable to increase its filling rate, but separation between the inorganic filler and the cured resin occurs, resulting in moisture condensing in the gap and deteriorating the dielectric properties. In particular, boron nitride has low affinity with general resins, making it prone to problems.

[0005] The dielectric properties required for low-dielectric resins include the relative permittivity, which is important, but the dielectric loss tangent is also important when signal transmission distances are long. One cause of the dielectric loss tangent is the rotational motion of the benzene ring and electron density. Methods for suppressing rotational motion include the application of compounds with long side chains (Patent Document 6) and the use of structures with alicyclic rings (Patent Document 7). However, when attempting to impart liquid crystallinity to improve thermal conductivity, a bent structure does not result in liquid crystal formation, and adding long side chains results in the phonon vibrations that transmit heat being scattered by the side chains, resulting in a problem of low thermal conductivity.

[0006] International Publication No. 2017 / 077845 JP 2018-502938 A JP 2012-246367 A JP 2006-265527 A JP 2022-020217 A JP 2023-147245 A JP 2020-186392 A

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

[0008] The problem to be solved by the present invention is to further improve the low dielectric loss tangent performance of conventional low-dielectric, high-thermal-conductivity polymeric liquid crystals having epoxy or oxetane groups while maintaining their low dielectric constant and high heat dissipation (thermal conductivity). This makes it possible to realize electronic components suitable for the 5G and 6G eras using the same production equipment and methods as in conventional semiconductor manufacturing processes. Furthermore, the use of the low dielectric loss tangent resin-forming composition of the present invention can provide materials suitable for applications in next-generation communication devices and radars in the high-frequency range.

[0009] The present inventors have conducted extensive research to solve the above problems and have found that a composition containing a polymerizable liquid crystal compound (1) having a lateral substituent in the core structure of the molecule can be used to form a coating for electronic components or electronic substrates by solution processing using a varnish, and that after curing, it is possible to realize a composition for forming a low dielectric loss tangent resin, which is a curable resin composition that exhibits high heat resistance, a low dielectric constant and a low dielectric loss tangent in the high frequency range, and high heat dissipation, thereby completing the present invention.The polymerizable liquid crystal compound (1) used in the present invention also has the characteristics of having a lower melt viscosity than conventional epoxy compounds and being less likely to generate voids even when heavily filled with inorganic filler.

[0010] The present invention has the following features: [1] A composition for forming a low dielectric loss tangent resin, which contains a liquid crystalline compound having a polymerizable group at a terminal represented by formula (1), and when the composition is cured without adding an inorganic filler, the cured product has a dielectric loss tangent at 10 GHz of less than 0.02. In formula (1), A １ is a group selected from ring structures represented by the following formulas (R1-1) to (R1-8), In formulae (R1-1) to (R1-8), X １ is halogen or alkyl having 1 to 6 carbon atoms, and in the formula, X １ When there are a plurality of A's, they may be the same or different. ２ and A ３are independently 1,4-phenylene, in which at least one hydrogen may be replaced by halogen or alkyl having 1 to 6 carbon atoms in which at least one hydrogen may be replaced by halogen; Z １ and Z ４ are independently alkylene having 2 to 20 carbon atoms; and in the alkylene having 3 to 20 carbon atoms, at least one —CH ２ - may be replaced by -O-, Z ２ and Z ３ are independently a single bond or an alkylene having 1 to 20 carbon atoms; in this alkylene, at least one —CH ２ - may be replaced by -O-, p is 0 or 1, R １ａ and R １ｂ are independently a group selected from the polymerizable groups represented by formula (PG-1), In formula (PG-1), R ｂ represents hydrogen, halogen, -CF ３ or alkyl having 1 to 5 carbon atoms, and q is 0 or 1.

[0011] [2] In formula (1), R １ａ and R １ｂ are the same polymerizable group represented by formula (PG-1).

[0012] [3] The low dielectric loss tangent resin-forming composition according to [1] or [2], wherein the melting point of the liquid crystal compound having a polymerizable group at the end represented by formula (1) is 104°C or less, or the transition temperature from a crystalline phase to a nematic phase is 104°C or less.

[0013] [4] The composition for forming a low dielectric loss tangent resin according to [1], containing at least one liquid crystal compound having a polymerizable group at its terminal, represented by formulas (1-1) to (1-3): In formulas (1-1) to (1-3), Z １ and Z ４ are independently -(CH ２ ) ａ -, -O(CH ２ ) ｂ -, -(CH２ ) ｂ O-, or -O(CH ２ ) ｃ O—, where a is an integer from 2 to 12, b is an integer from 2 to 11, and c is an integer from 1 to 10; Z ２ is a single bond, -(CH ２ ) ａ -, -O(CH ２ ) ｂ -, -(CH ２ ) ｂ O-, or -O(CH ２ ) ｃ O-, wherein a is an integer of 1 to 12, b is an integer of 1 to 11, and c is an integer of 1 to 10, X is fluorine or methyl, Me is methyl, n is an integer of 0 to 4, including when n is 2 or more, and when there are multiple Xs in the formula, they may be the same or different, and R １ａ and R １ｂ are independently a polymerizable group represented by formula (PG-1), In formula (PG-1), R ｂ represents hydrogen, halogen, -CF ３ or alkyl having 1 to 5 carbon atoms, and q is 0 or 1.

[0014] [5] In formula (1), R １ａ and R １ｂ are the same polymerizable group represented by formula (PG-1), and in formula (PG-1), R ｂ The low dielectric loss tangent resin-forming composition according to [1], wherein is hydrogen and q is 0.

[0015] [6] The composition for forming a low dielectric loss tangent resin according to any one of [1] to [5], which contains at least one selected from the following (A) and (B): (A) a polymer of a liquid crystal compound having a polymerizable group at its terminal, represented by formula (1); and (B) a polymerizable compound other than the liquid crystal compound having a polymerizable group at its terminal, represented by formula (1).

[0016] [7] The composition for forming a low dielectric loss tangent resin according to any one of [1] to [6], containing a difunctional to tetrafunctional curing agent having a linear molecular structure.

[0017] [8] The low dielectric loss tangent resin-forming composition according to any one of [1] to [7], which contains an inorganic filler, wherein the thermal conductivity of a cured product obtained by curing the composition is 1 W / m K or more.

[0018] [9] The low dielectric loss tangent resin-forming composition according to any one of [1] to [7], containing an inorganic filler that is a nitride filler, wherein the composition has a thermal conductivity of 10 W / m K or more.

[0019]

[10] The low dielectric loss tangent resin-forming composition according to [8] or [9], wherein the inorganic filler is at least one selected from the group consisting of silicon oxide compounds such as spherical silica, pulverized silica, hollow silica, and fumed silica, metal nitrides such as aluminum nitride, boron nitride, and silicon nitride, diamond, graphite, silicon carbide, and metal oxides such as magnesium oxide, aluminum oxide, zinc oxide, titanium oxide, tin oxide, and calcium oxide.

[0020]

[11] The low dielectric loss tangent resin-forming composition according to [1], which contains a fibrous heat-dissipating filler, wherein the fibrous heat-dissipating filler is at least one selected from the group consisting of carbon fiber, carbon nanotube, polyamide fiber, aramid fiber, polyparaphenylene benzobisoxazole fiber, liquid crystalline polyester fiber, silicate whisker, alumina whisker, magnesium oxide whisker, zinc oxide whisker, aluminum nitride whisker, and cellulose nanofiber.

[0021]

[12] A low dielectric loss tangent resin insulating film, which is a polymer molded product obtained by curing the low dielectric loss tangent resin-forming composition according to any one of [1] to

[11] with heat or ultraviolet light.

[0022]

[13] A low dielectric loss tangent resin film or a low dielectric loss tangent resin sheet, which is a polymer molded product obtained by curing the low dielectric loss tangent resin-forming composition according to any one of [1] to

[11] with heat or ultraviolet light.

[0023]

[14] A low dielectric loss tangent resin part, which is a polymer molded product obtained by curing the low dielectric loss tangent resin-forming composition according to any one of [1] to

[11] with heat or ultraviolet light.

[0024]

[15] An electronic device using the polymer molded body according to any one of

[12] to

[14] .

[0025] The composition of the present invention containing a polymerizable liquid crystal compound having a lateral substituent in the molecular core structure is characterized by a lower dielectric dissipation factor of the cured product compared to a composition without side chains. Furthermore, because it melts at temperatures around 100°C or lower, it can be liquefied below the curing temperature of the epoxy group and processed directly into a film or sheet. Furthermore, its low melt viscosity allows for high loading of highly thermally conductive fillers, and resin components can be filled into the pores of porous fillers using a vacuum mixer. The cured product obtained by curing the composition of the present invention has low dielectric properties, high heat dissipation, and excellent properties in at least one of chemical stability, heat resistance, hardness, and mechanical strength. Therefore, it can be used to form, for example, internal substrates for IC chips with high heat generation, low-dielectric interlayer insulating films, low-dielectric adhesives, low-dielectric underfill materials, etc., and is suitable for insulating resin applications such as next-generation communication devices and radars in the high-frequency range. It can also be used favorably for power semiconductor device substrates, etc., by combining it with highly thermally conductive fillers such as boron nitride to utilize its high thermal conductivity and high heat resistance.

[0026] FIG. 1 shows a simple mold made of a PTFE sheet, which was fabricated for use in the Examples and Comparative Examples by sandwiching it between release PTFE sheets in order to control the thickness of the molten composition and prevent the melt from leaking out during dielectric property measurement.

[0027] The following describes in detail the polymerizable liquid crystal compounds used in the present invention, which have lateral substituents in the molecular core structure; compositions for forming low dielectric loss tangent resins containing at least one selected from the polymerizable liquid crystal compounds; polymer molded articles of low dielectric loss tangent resins obtained by curing the compositions with heat or ultraviolet light, such as low dielectric loss tangent resin insulating films, low dielectric loss tangent resin films, low dielectric loss tangent resin sheets, and low dielectric loss tangent resin components; and electronic devices using the polymer molded articles, as well as methods for manufacturing these. The terms used in this specification are as follows: "Liquid crystal compound" is a general term for compounds that have a liquid crystal phase, such as a nematic phase or a smectic phase, and compounds that do not have a liquid crystal 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. Alignment processing is facilitated within the liquid crystal temperature range, allowing molecular orientation to be controlled similarly to the stretching process for thermoplastic resins. "Epoxy compound" is a general term for oxirane compounds and oxetane compounds, and "epoxy group" is a general term for oxiranyl and oxetanyl groups. "Compound (1)" means a polymerizable liquid crystal compound represented by the formula (1), and may also mean at least one compound represented by the formula (1). The same applies to "compound (1-1)" and the like, and compounds (1-1), (1-2) and (1-3) may also be collectively referred to as "compound (1)". One compound (1) may contain multiple X １ When any two X １ may be the same or different. ｂ When any two R ｂ may be the same or different. This rule also applies to other symbols, groups, etc., such as q and X. "Polymer (1)" means at least one polymer obtained by polymerizing the compound (1). As with "compound (1)," the polymers of compounds (1-1), (1-2), and (1-3) may also be collectively referred to as "polymer (1)." "Composition (1)" means a composition containing at least one compound selected from the compound (1), i.e., the composition for forming a low dielectric loss tangent resin of the present invention.

[0028] 1) Compound (1) The polymerizable liquid crystal compound (1) (hereinafter sometimes referred to as compound (1)) used in the present invention, which has a substituent at a lateral position in the molecular core structure, has a liquid crystal skeleton (rod-shaped mesogenic skeleton) and a polymerizable group, preferably with few conjugated or polar groups, high molecular linearity and symmetry, high polymerization reactivity, a low melting point, or a phase transition temperature from a crystalline to a nematic or isotropic phase. Similar to compound (1), epoxy compounds in which oxiranyl groups are directly attached to a biphenyl skeleton having four methyl groups have long been commercially available and have been used in semiconductor encapsulation and other applications. However, due to their high melting points and short molecular chains, their thermal conductivity was only slightly higher than that of bisphenol-type epoxy compounds. Therefore, compound (1) can be said to be a compound in which alkyl groups are linearly extended on both sides of the biphenyl skeleton and epoxy groups are introduced at the ends of the alkyl groups, thereby lowering the melting point, increasing thermal conductivity, and imparting flexibility. The melting point or the phase transition temperature from crystal to nematic or isotropic phase of compound (1) is preferably 120°C or less, more preferably 110°C or less, even more preferably 104°C or less, and particularly preferably 80°C or less, from the viewpoint of molding and curing temperature. The melting point and phase transition temperature can be lowered by extending the alkylene at both ends. Compound (1) used in the present invention and represented by the formula (1) is composed of groups such as a ring structure, a bonding group, and a terminal group. The terminal group R of compound (1) １ａ or R １ｂ , ring structure A １ , A ２ or A ３ and the bonding group Z １ , Z ２ , Z ３ or Z ４ By appropriately selecting these groups, the physical properties such as the liquid crystal phase region can be adjusted as desired. The effects of the types of terminal group, ring structure and bonding group on the physical properties of compound (1), as well as preferred examples thereof, are explained 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 ". In addition, "at least one -CH ２The meaning of phrases such as "- may be replaced by -O-" is shown below as an example. For example, C ４ H ９ At least one —CH ２ Examples of a group in which - is replaced by -O- include CH ７ O-, CH ３ -O-(CH ２ ) ３ -, CH ３ -O-CH ２ In this way, the term "at least one" means "at least one selected without distinction." In consideration of the stability of the compound, it is preferable that oxygen atoms are not adjacent to each other. ３ -O-O-CH ２ -, rather than oxygen and oxygen are not adjacent ３ -O-CH ２ --O-- is preferred.

[0029] <Ring structure A: A １ , A ２ and A ３ > Ring structure A of compound (1) １ is a group selected from ring structures represented by the following formulas (R1-1) to (R1-8). In formulas (R1-1) to (R1-8), X １ is halogen or alkyl having 1 to 6 carbon atoms. １ When there are a plurality of ring structures, they may be the same or different. １ Preferred examples of the formula are (R1-1), (R1-2) and (R1-3), where X １ When R is fluorine or methyl, the compound has a low melting point, exhibits fluidity at around room temperature, and exhibits high solubility in organic solvents. ２ and A ３is 1,4-phenylene, and in this ring, at least one hydrogen may be replaced by a halogen or an alkyl having 1 to 6 carbon atoms in which at least one hydrogen may be replaced by a halogen. When this ring structure is used, it has the characteristics of a high clearing point, a very low dielectric tangent, a low dielectric loss, and a low viscosity. Furthermore, since it often has a low melting point and exhibits fluidity around room temperature, it becomes possible to easily prepare a composition that can be formed into a film by a coating method using no solvent or a small amount of organic solvent. From the viewpoint of manufacturing advantages, it is preferred that the ring structure A ２ and A ３ is preferably 1,4-phenylene in which at least one hydrogen may be replaced by halogen or alkyl.

[0030] Ring structure A of compound (1) ２ and A ３ Particularly preferred examples include 1,4-phenylene, 2-methyl-1,4-phenylene, 3-methyl-1,4-phenylene, 2,3-dimethyl-1,4-phenylene, 2,5-dimethyl-1,4-phenylene, 2,6-dimethyl-1,4-phenylene, 3,5-dimethyl-1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, and 3,5-difluoro-1,4-phenylene.

[0031] When at least one ring in the ring structure A is 1,4-phenylene or the above-mentioned substituted 1,4-phenylene, the orientational order parameter and magnetic anisotropy are large. Furthermore, when at least two rings are 1,4-phenylene or the above-mentioned substituted 1,4-phenylene, the clearing point is high. Preferred examples of 1,4-phenylene rings in which at least one hydrogen atom on the 1,4-phenylene ring may be replaced include fluorine, alkyl having 1 to 6 carbon atoms, or -CF ３ The melting point is lowered and the solubility is high. Also, the molecular polarizability is small, so the dielectric loss tangent is low. Furthermore, the molecular motion is suppressed, so the dielectric loss is low. From the viewpoint of thermal conductivity, X １It is preferable that X is symmetrically positioned with respect to the main chain as in formula (R1-2) and formula (R1-3), because the phonon vibration transmitted through the main chain is not inhibited by asymmetric motion, resulting in high thermal conductivity. １ In the case of alkyl, when the number of carbon atoms increases, X １ Since the phonons are dispersed along X １ has 1 or 2 carbon atoms, and it is preferable that the number of carbon atoms is the same on the same phenylene ring.

[0032] <Binding group Z: Z １ , Z ２ , Z ３ and Z ４ > Bonding group Z １ and Z ４ are independently alkylene having 2 to 20 carbon atoms; and in the alkylene having 3 to 20 carbon atoms, at least one —CH ２ - may be replaced by -O-. ２ and Z ３ are independently a single bond or an alkylene having 1 to 20 carbon atoms; in this alkylene, at least one —CH ２ - may be replaced by -O-. Preferred examples of the bonding group Z in compound (1) include Z １ and Z ４ are independently -(CH ２ ) ａ -, -O(CH ２ ) ｂ -, -(CH ２ ) ｂ O-, or -O(CH ２ ) ｃ O—, where a is an integer from 2 to 12, b is an integer from 2 to 11, and c is an integer from 1 to 10; Z ２ and Z ３ is a single bond, -(CH ２ ) ａ -, -(CH ２ ) ｂ O- or -O(CH ２ ) ｂ - and -O(CH ２ ) ｂ -, -(CH ２ ) ｂO-, or -O(CH ２ ) ｃ O-, where a is an integer of 1 to 12, b is an integer of 1 to 11, and c is an integer of 1 to 10, the molecular length is long, the melting point or the phase transition temperature from a crystalline phase to a nematic phase is low, the thermal conductivity is high, and the dielectric loss tangent is small.

[0033] <Terminal group R １ :R １ａ and R １ｂ > Terminal group R of compound (1) １ is a polymerizable group represented by formula (PG-1).

[0034]

[0035] In formula (PG-1), R ｂ represents hydrogen, halogen, -CF ３ or alkyl having 1 to 5 carbon atoms, and q is 0 or 1.

[0036] Terminal group R of compound (1) １ Preferred examples of the polymerizable groups include those represented by formulae (PG-1a) to (PG-1d).

[0037]

[0038] Among these preferred polymerizable groups, (PG-1a) to (PG-1d) have a strained cyclic ether, and therefore can be polymerized by various means to be converted into a polymer having a larger molecular weight.

[0039] The curing agent and curing accelerator to be combined with the polymerizable group represented by formula (PG-1) can be appropriately selected depending on the production conditions and application of the low dielectric loss tangent resin. Compound (1) used in the present invention has a low melt viscosity, so if a thick coating is required, it may be partially polymerized in advance, or if an extremely thin film is desired, an appropriate organic solvent may be used.

[0040] As described above, the ring structure A, the bonding group Z, and the terminal group R １ A compound having the desired physical properties can be obtained by appropriately selecting the type of ring, the number of rings, etc. Preferred examples of compound (1) include compounds represented by formulas (1-1) to (1-3).

[0041]

[0042] In formulas (1-1) to (1-3), Z １ and Z ４ are independently -(CH ２ ) ａ -, -O(CH ２ ) ｂ -, -(CH ２ ) ｂ O-, or -O(CH ２ ) ｃ O—, where a is an integer from 2 to 12, b is an integer from 2 to 11, and c is an integer from 1 to 10; Z ２ is a single bond, -(CH ２ ) ａ -, -O(CH ２ ) ｂ - or - (CH ２ ) ｂ O-, and -O(CH ２ ) ｂ -, -(CH ２ ) ｂ O-, or -O(CH ２ ) ｃ O-, wherein a is an integer of 1 to 12, b is an integer of 1 to 11, and c is an integer of 1 to 10; X is fluorine or methyl, Me is methyl, n is an integer of 0 to 4, including the case where n is 2 or more, and when there are multiple Xs in the formula, they may be the same or different; R １ａ and R １ｂ are independently polymerizable groups represented by formula (PG-1).

[0043] In formula (PG-1), R ｂ is hydrogen, halogen, —CF 3 , or alkyl having 1 to 5 carbon atoms; and q is 0 or 1.

[0044] [Method for Synthesizing Compound (1)] Compound (1) can be synthesized by combining known techniques in organic synthetic chemistry. Methods for introducing desired terminal groups, ring structures, and bonding groups into starting materials are described in, for example, 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 Lectures (Maruzen).

[0045] The method for introducing the bonding group Z is explained in the following schemes 1 to 4. In these schemes, MSG １ and MSG ２ represents a monovalent organic group having at least one ring, and Hal represents a halogen. １ (or MSG ２ ) may be the same or different. Compounds (1A) to (1F) in the following scheme correspond to the above-mentioned compound (1). These methods can be applied to the synthesis of optically active compound (1) and optically inactive compound (1).

[0046] (Scheme 1) Compounds in which Z is a single bond As shown below, arylboronic acid (S1) is reacted with compound (S2) synthesized by a known method in the presence of an aqueous carbonate solution and a catalyst such as tetrakis(triphenylphosphine)palladium to give MSG. １ and MSG ２Compound (1A) can be synthesized by introducing a single bond between compound (S3) and compound (S4). Compound (1A) can also be synthesized by reacting compound (S3), which is synthesized by a known method, with n-butyllithium and then zinc chloride, and then further reacting compound (S2) in the presence of a catalyst such as dichlorobis(triphenylphosphine)palladium.

[0047]

[0048] (Scheme 2) Z is -(CH ２ ) ２ As shown below, compound (1B) obtained as above is hydrogenated in the presence of a catalyst such as palladium carbon to give MSG. １ and MSG ２ Between - (CH ２ )2-, a compound (1C) having the formula (1C) can be synthesized.

[0049]

[0050] (Scheme 3) Z is -(CH ２ As shown below, a compound of —(CH 4)4- can be prepared by using a phosphonium salt (S7) according to the method of Scheme 3. ２ ) A compound having 2-CH=CH- is synthesized, and this is catalytically hydrogenated in the same manner as in Scheme 2 to give MSG. １ and MSG ２ Between - (CH ２ Compound (1E) having 4- can be synthesized.

[0051]

[0052] (Scheme 4) Z is —CH ２ O- or -OCH ２ As shown below, compound (S4) is reduced with a reducing agent such as sodium borohydride to obtain compound (S8). Compound (S9) is obtained by halogenating compound (S9) with hydrobromic acid or the like. Compound (S9) is reacted with compound (S10) in the presence of potassium carbonate or the like to obtain MSG. １ and MSG ２ Between -OCH２ - (or -CH ２ Compound (1F) having a substituted aryl group (O-) can be synthesized.

[0053]

[0054] 2) Polymer (1) The compound (1) used in the present invention has a polymerizable group (terminal group R １ ), it can be easily polymerized. The polymer (1) in the present invention is at least one type of polymer obtained by polymerizing the compound (1). In the composition (1) described in the next section, the polymer (1) formed by combining at least one other component may be an oligomer of the compound (1). This oligomer refers to a low polymer having a small number (degree of polymerization) of constitutional units of the compound (1) that constitutes the polymer (1). Depending on the number of constitutional units, the oligomer may be called a dimer, trimer, tetramer, etc.

[0055] 3) Composition (1) The composition (1) of the present invention is a composition containing at least one compound (1). That is, the composition (1) may be composed of two or more compounds (1), or may be composed of a combination of at least one compound (1) and at least one other component other than the compound (1), including the polymer (1). The at least one other component is not particularly limited, but examples thereof include polymer (1), a polymerizable compound other than the compound (1) (hereinafter also referred to as "other polymerizable compound"), a curing agent, an organic solvent, a non-polymerizable liquid crystal compound, an inorganic filler, and a fibrous heat-dissipating filler. Preferred compositions (1) include compositions composed of at least one compound (1) and a polymer (1), compositions composed of at least one compound (1) and other polymerizable compounds, and compositions composed of at least one compound (1), polymer (1), and other polymerizable compounds.

[0056] 4) Other Polymerizable Compounds The composition (1) may contain a polymerizable compound (other polymerizable compound) other than the compound (1). The polymerizable compound other than the compound (1) is composed of at least one polymerizable liquid crystal compound other than the compound (1) (hereinafter also referred to as "other polymerizable liquid crystal compound") and at least one polymerizable non-liquid crystal compound (hereinafter also referred to as "other polymerizable non-liquid crystal compound"). 4-1) Other Polymerizable Liquid Crystal Compounds The composition (1) may contain at least one polymerizable liquid crystal compound other than the compound (1). From the viewpoint of the development of a liquid crystal phase and the nematic transition temperature of the polymerizable liquid crystal composition (1), compounds represented by formulas (M1) to (M3) and compounds having similar structures are preferred as the polymerizable liquid crystal compound. When an ester bond is present between the 1,4-phenylene units, as in the compound (M1), the dielectric properties and heat resistance are inferior to those of the compound of the present invention, but improved adhesion to metals can be expected. The content of compound (M1) is preferably such that it does not deteriorate the dielectric properties or heat resistance. When the compound has a polymerizable group such as compound (M2) or compound (M3), a polymerizable liquid crystal compound having a (meth)acrylic group or the like that does not react with an epoxy group can be added to form a polymer alloy utilizing layer separation or a fine structure such as an artificial opal structure, but in this case, a polymerization initiator that generates radicals is separately required.

[0057]

[0058] 4-2) Other Polymerizable Non-Liquid Crystalline Compounds Composition (1) may contain at least one other polymerizable non-liquid crystal compound as a constituent element. Such other polymerizable non-liquid crystal compounds are preferably compounds that do not reduce film-forming properties and mechanical strength. These polymerizable non-liquid crystal compounds are classified as compounds that do not have liquid crystallinity. Examples of other polymerizable non-liquid crystallinity compounds that are polymerizable compounds that do not have liquid crystallinity include derivatives such as vinyl derivatives, styrene derivatives, (meth)acrylic acid derivatives, sorbic acid derivatives, fumaric acid derivatives, and itaconic acid derivatives; modified polyimide oligomers, modified maleimide oligomers, modified polyphenylene ether oligomers, modified polyphenylene sulfide oligomers, and modified polybutadiene elastomers; and modified engineering plastic oligomers, i.e., macromers, which refer to high-molecular-weight compounds having polymerizable functional groups. Preferred examples of these derivatives are shown below. In the present specification, "(meth)acryloyloxy" means acryloyloxy or methacryloyloxy, "(meth)acrylate" means acrylate or methacrylate, and "(meth)acrylic" means acrylic or methacrylic.

[0059] Preferred examples of the vinyl derivative 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, vinyl 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.

[0060] Preferred styrene derivatives include, for example, styrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, o-chloromethylstyrene, m-chloromethylstyrene, p-chloromethylstyrene, and α-methylstyrene.

[0061] Preferred examples of the (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 adduct triacrylate, pentaerythritol triacrylate, tris(meth)acryloyloxyethyl phosphate, bisphenol A EO adduct diacrylate, bisphenol A glycidyl diacrylate (trade name: "Biscoat 700" manufactured by Osaka Organic Chemical Industry Ltd.), polyethylene glycol diacrylate dimethyl itaconate, and the like.

[0062] Preferred examples of the 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 propargyl sorbate.

[0063] Preferred fumaric acid derivatives include, for example, dimethyl fumarate, diethyl fumarate, diisopropyl fumarate, dibutyl fumarate, dicyclopentyl fumarate, and dicyclohexyl fumarate.

[0064] Preferable itaconic acid derivatives include, for example, diethyl itaconate, dibutyl itaconate, diisopropyl itaconate, etc. In addition to these, many polymerizable non-liquid crystal compounds such as butadiene, isoprene, maleimide, etc. can also be used.

[0065] 5) Curing Agent The composition (1) may contain a curing agent as a component. Preferred examples of the curing agent are shown below.

[0066] Examples of amine curing agents include 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, norbornene diamine, and 1,2-diaminocyclohexane. hexane, 3,9-dipropanamine-2,4,8,10-tetraoxaspiro[5.5]undecane, 4,4'-diaminodiphenylmethane, 4,4'-ethylenedianiline (also known as 4,4'-diamino-1,2-diphenylethane), o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenyl sulfone, polyoxypropylene diamine, polyoxypropylene triamine, polycyclohexylpolyamine, and N-aminoethylpiperazine.

[0067] Examples of acid anhydride 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 bisanhydrotrimethylate, glycerin bis(anhydrotrimellitate) monoacetate, dodecenyl succinic anhydride, and chlorendic anhydride.

[0068] Examples of phenol-based 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, bisphenol A novolac, etc. In addition to the above, curing agents described in JP-A Nos. 2004-256687 and 2002-226550 can also be used.

[0069] The active ester curing agent is not particularly limited, and known active ester curing agents can be used. Examples of commercially available active ester curing agents include "EPICLON (registered trademark) 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 product of phenol novolac, "YLH1026" manufactured by Mitsubishi Chemical Corporation as an active ester compound containing a benzoylated product of phenol novolac, "DC808" manufactured by Mitsubishi Chemical Corporation as an active ester curing agent which is an acetylated product of phenol novolac, and "YLH1026" manufactured by Mitsubishi Chemical Corporation as an active ester curing agent which is a benzoylated product of phenol novolac.

[0070] Further, examples of the curing accelerator include 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 the cycloamidine compounds containing maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, and 2,3-dimethoxy-5-methylbenzoquinone. compounds having intramolecular polarization obtained by adding a compound having a π bond, such as quinone compounds such as 1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone, diazophenylmethane, and phenol resins; tertiary amine compounds such as benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; derivatives of the tertiary amine compounds; 2-methylimidazole, 2-phenylimidazole, 2-phenylimidazole, and 2-phenyl-1,4-benzoquinone; 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 a compound having a π bond such as maleic anhydride, the above-mentioned quinone compounds, diazophenylmethane, or a phenol resin 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 the tetraphenylboron salts with phosphine compounds such as triphenylphosphonium-triphenylborane and N-methylmorpholine tetraphenylphosphonium-tetraphenylborate.

[0071] 6) Organic Solvent The composition (1) may contain an organic solvent. The composition (1) may be cured in an organic solvent or without a solvent. For example, the composition (1) containing an organic solvent may be applied to a substrate by spin coating or the like, and then the organic solvent may be removed before photocuring. After photocuring, the composition may be heated to an appropriate temperature for post-treatment by thermal curing.

[0072] Preferred organic solvents include, for example, benzene, toluene, xylene, mesitylene, hexane, heptane, octane, nonane, decane, tetrahydrofuran, 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). The above organic solvents may be used alone or in combination of two or more. It is not particularly meaningful to limit the proportion of organic solvent used during curing; the proportion may be determined for each individual case, taking into consideration curing efficiency, solvent cost, energy cost, and the like.

[0073] Composition (1) of the present invention preferably contains 70 wt% or less of an organic solvent by total weight, and a solvent-free composition is particularly preferred. A solvent-free composition is a composition that can be prepared into a varnish that maintains fluidity at room temperature without the use of an organic solvent or that exhibits high fluidity when melted. Using a composition containing 70 wt% or less of an organic solvent by total weight or a solvent-free composition increases the concentration of the cured product, allowing the functionality of the cured product to be effectively expressed. Composition (1) before curing remains liquid at around room temperature and maintains fluidity, and can be used as is as a solvent-free varnish or as a varnish containing 70 wt% or less of an organic solvent by total weight. In other words, it can be used directly for applications such as coating or adhesion, eliminating the need for a process such as volatilizing the solvent at high temperatures. 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, ethanol, and the like, which are relatively low in toxicity from the perspective of environmental impact. The composition (1) of the present invention can form a low dielectric loss tangent resin having high heat resistance and high linearity in a non-organic solvent system, and therefore can provide insulating materials for various electronic parts such as laminates for printed wiring boards, interlayer insulating materials for substrates, adhesive films, semiconductor encapsulants, and conductive adhesives.

[0074] 7) Non-Polymerizable Liquid Crystalline Compounds Composition (1) may contain a liquid crystal compound without a polymerizable group as a component. Examples of such non-polymerizable liquid crystal compounds are described in LiqCryst (LCI Publisher GmbH, Hamburg, Germany), a database of liquid crystal compounds. By curing composition (1) containing a non-polymerizable liquid crystal compound, composite materials containing a polymer of compound (1) and a liquid crystal compound can be obtained. In such composite materials, the non-polymerizable liquid crystal compound exists in a polymer network, such as a polymer-dispersed liquid crystal.

[0075] 8) Inorganic Fillers and Fibrous Thermally Dissipative Fillers Inorganic fillers can be added to composition (1) to improve thermal conductivity, mechanical strength, adjust viscosity, and the like. In this specification, inorganic fillers are sometimes referred to as inorganic fillers. For example, to reduce dielectric loss, silicon compounds such as spherical silica, pulverized 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, with hollow silica being more preferred. Fibrous thermally dissipative fillers can be used as fibrous or whisker-like fillers to increase the strength of substrates and resin parts. Inorganic fibers such as carbon fibers and carbon nanotubes, and inorganic whiskers such as silicate whiskers, alumina whiskers, magnesium oxide whiskers, zinc oxide whiskers, and aluminum nitride whiskers are preferred, with aluminum nitride whiskers and carbon nanotubes being more preferred. To increase mechanical strength, a larger amount of filler is preferable, but if there is too much, the resin may not be able to fill the gaps in the filler. Furthermore, if the amount of resin is too large, the effect of increasing mechanical strength may not be achieved. Furthermore, increasing the amount of filler tends to increase the dielectric constant and decrease the dielectric dissipation factor, so it is preferable to determine the composition while balancing these two factors. In addition to inorganic fibers, organic fibers can also be used as fibrous heat-dissipating fillers. Examples of organic fibers with high mechanical strength include polyamide fibers, aramid fibers, polyparaphenylene benzobisoxazole fibers, liquid crystalline polyester fibers, and cellulose nanofibers. Compared to inorganic fibers, organic fibers are lighter, making them suitable for substrates of portable devices.Fillers with high thermal conductivity include powdered metal nitrides such as 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 and 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 due to its low dielectric constant and high thermal conductivity. The more inorganic filler is used, the higher the thermal conductivity, but inorganic fillers generally have a higher relative dielectric constant and a smaller dielectric dissipation factor than resin components, so increasing the filling amount increases the dielectric constant. Therefore, it is preferable to fill the required amount within a range that does not exceed the desired dielectric constant. When heat resistance is not required, the use of cellulose nanofibers results in a slightly higher dielectric constant, but is preferable because of its high thermal conductivity and light weight. Composition (1) of the present invention has high transparency and not only low dielectric constant, but also low refractive index. When used in optical materials, the refractive index can be adjusted by adding powders such as hollow silica, spherical silica, titanium oxide, and zirconium oxide.

[0076] The shape of the filler may be spherical, amorphous, fibrous, whisker-like, cylindrical, plate-like, etc. The type, shape, size, and amount of filler added can be appropriately selected depending on the purpose. When the resulting polymer molded article requires insulation, a conductive filler may be used as long as the desired insulation properties, mechanical strength, dielectric constant, dielectric dissipation factor, and dielectric loss are maintained.

[0077] 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 diameter of 0.1 μm or greater provides good thermal conductivity, while a diameter of 200 μm or less allows for a high filling rate. Regarding fibrous fillers, longer fiber lengths improve tensile strength, but may make kneading or dispersion difficult. Therefore, it is best to select the size based on the application. When dispersed, the average particle size of the fibrous filler is preferably 0.01 to 200 μm. More preferably, it is 0.1 to 100 μm. A diameter of 0.01 μm or greater provides good thermal conductivity, while a diameter of 200 μm or less increases mechanical strength. The amount of filler is preferably 20 to 95 wt% in the cured polymer molded body. More preferably, it is 50 to 95 wt%. A diameter of 20 wt% or greater provides high thermal conductivity, which is preferable. A diameter of 95 wt% or less is preferable because it prevents the polymer molded body from becoming brittle.

[0078] As the filler, commercially available products that have been surface-treated, such as affinity-treated, adhesion-facilitating-treated, dispersion-treated, or waterproof-treated, may be used as they are, or the commercially available products from which the surface treatment agents have been removed may be used. Alternatively, untreated fillers may be used after being treated with a silane coupling agent, affinity agent, surface tension adjuster, anti-settling agent, anti-aggregation agent, etc.

[0079] 9) Other Additives Because compound (1) and composition (1) are highly polymerizable, a stabilizer may be added to composition (1) to facilitate handling. Known stabilizers can be used without limitation, and examples of such stabilizers include hydroquinone, 4-ethoxyphenol, and 3,5-di-t-butyl-4-hydroxytoluene (BHT). For applications requiring a low dielectric dissipation factor (low tan δ) and a high glass transition temperature, it is preferable to add a crosslinking agent. The crosslinking agent preferably chemically bonds with the polymerizable group of compound (1) having a terminal polymerizable group used in the present invention to form a three-dimensional crosslink.

[0080] To adjust the properties of the cured product, the composition (1) of the present invention may contain other resins that do not react with the compound (1) used in the present invention. Examples of such resins include polyphenylene ether resins, polystyrene resins, polycarbonate resins, polyimide resins, polyamide resins, polyester resins, polybutadiene copolymers, polyvinyl acetal resins, natural rubber, synthetic rubber, synthetic elastomers, epoxy resins with a skeleton different from that of the compound (1) used in the present invention, oxetane resins, acrylic resins, methacrylic resins, maleimide resins, oxazine resins, and oxazoline resins. When dielectric properties are particularly important, polyphenylene ether resins, polystyrene resins, and polycarbonate resins are preferred. These resins may contain unreacted sites that may react with the compound (1) used in the present invention. In such cases, a crosslinked structure is formed, which is expected to result in improved properties compared to when the reaction is not complete.

[0081] 10) Low Dielectric Loss Tangent Resin The low dielectric loss tangent resin, which is another embodiment of the present invention, is a cured product of the composition (1) and therefore has a low dielectric constant, and is also excellent in thermal conductivity, heat resistance, rigidity, elasticity, molding flowability, chemical resistance, dimensional stability, and the like.

[0082] When a low dielectric loss tangent resin exhibits liquid crystallinity, molecular orientation can be controlled by pre-curing orientation treatment. The dielectric loss tangent and thermal conductivity exhibit anisotropy depending on the molecular orientation direction. For example, when designing the dielectric constant and thermal design of an electronic substrate, more advanced material design is possible, such as designing the area directly below the heat-generating IC to have high thermal conductivity in the thickness direction, and aligning the area other than directly below the IC in the horizontal direction to spread the heat over a wide area. The orientation method can be controlled by the following methods. Methods for controlling the orientation of the mesogenic portion of the liquid crystal molecules in a low dielectric loss tangent resin-forming composition include treating the surface of an inorganic filler with a silane coupling agent or alignment agent that has orientation ability, and orienting the liquid crystal molecules using the self-orientation restraining force of the composition itself. These methods may be performed alone or in combination. Examples of orientation states controlled by such orientation control methods include homogeneous, twisted, homeotropic, hybrid, bend, and spray orientation, and can be appropriately selected depending on the application and orientation control method. Furthermore, during film formation or molding, the liquid crystal material can be physically aligned by applying shear stress to it before it is cured.

[0083] The orientation temperature is in the range of room temperature to 250°C, preferably room temperature to 200°C, and more preferably room temperature to 180°C. The heat treatment time is in the range of 5 seconds to 2 hours, preferably 10 seconds to 60 minutes, and more preferably 20 seconds to 30 minutes. If the heat treatment time is shorter than the above range, the temperature of the layer made of composition (1) may not be raised to the desired temperature. If the heat treatment time is longer than the above range, productivity may decrease. Note that the above heat treatment conditions vary depending on the types and compositional ratios of the components used in composition (1), the presence and content of a polymerization initiator, etc., and therefore are merely approximate ranges. In particular, if the temperature is higher than the polymerization initiation temperature of the polymerizable components used in composition (1), the composition will harden before orientation occurs, making it impossible to obtain a low dielectric loss tangent resin with molecular chains oriented in a specific direction.

[0084] Conditions for fixing the orientation of composition (1) by thermal polymerization include a heat curing temperature in the range of room temperature to 350°C, preferably room temperature to 250°C, and more preferably 50°C to 200°C, and a curing time in the range of 5 seconds to 10 hours, preferably 1 minute to 5 hours, and more preferably 5 minutes to 1 hour. After curing, it is preferable to slowly cool the composition to suppress stress distortion. Furthermore, a reheating treatment may be performed to relieve distortion.

[0085] The orientation of the cured product or the composition in the curing process, which has been orientation-controlled as described above, may be further controlled in any direction by mechanical manipulation such as stretching. The isolated polymer (1) may be dissolved in an organic solvent and mixed with other components to prepare a composition, 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, for example, N-methyl-2-pyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, N,N-dimethylacetamide dimethyl acetal, tetrahydrofuran, chloroform, 1,4-dioxane, bis(methoxyethyl)ether, γ-butyrolactone, tetramethylurea, trifluoroacetic acid, ethyl trifluoroacetate, hexafluoro-2-propanol, 2-methoxyethyl acetate, methyl ethyl ketone, cyclopentanone, and cyclohexanone. These may be used by mixing with a small amount of a common organic solvent such as acetone, benzene, toluene, heptane, or methylene chloride.

[0086] When a highly linear, low-dielectric-tangent resin-forming composition exhibits a liquid crystal phase over a very narrow range, it forms domains with axes aligned in a certain direction if the crystallinity is high, resulting in higher thermal conductivity than polymerizable compounds such as bisphenol A. Orientation and crystallinity can also be controlled by slowly curing the resin from an isotropic liquid state with the surface of a polymer sheet with aligned orientation or a crystalline resin filler present as a core for crystal growth. However, excessive crystallinity tends to reduce flexibility, so it is necessary to use a composition with appropriate crystallinity.

[0087] 11) Low Dielectric Loss Tangent Resin Insulating Film, Low Dielectric Loss Tangent Resin Film, and Low Dielectric Loss Tangent Resin Sheet The polymer molded article of the present invention is a molded article of a low dielectric loss tangent resin, which is a cured product of the low dielectric loss tangent resin-forming composition comprising the above-mentioned composition (1). It can be used as a thin-film low dielectric loss tangent resin insulating film, as well as in film-, sheet-, plate-, fibrous-, or three-dimensionally shaped parts (insulating portions of connectors), or as a coating agent, adhesive, or filler. When used in a thin-film, film-, sheet-, plate-, fibrous-, or three-dimensionally shaped molded article, films and thin films are preferred. Films and thin films can be obtained by applying composition (1) to a substrate or release film, or by curing the composition between flat plates such as substrates and molds. Alternatively, composition (1) containing an organic solvent can be applied to an orientation-treated substrate and then removing the organic solvent. Furthermore, films can also be obtained by press-molding the cured product. In this specification, the thickness of a sheet is 1 mm or more, the thickness of a film is 5 μm or more but less than 1 mm, preferably 10 to 500 μm, more preferably 20 to 300 μm, and the thickness of a thin film is less than 5 μm.

[0088] A method for producing a film as a polymer molded article using composition (1) containing an organic solvent will be specifically described below. First, composition (1) is applied to a release-treated substrate, and the organic solvent is dried and removed to form a coating layer with a uniform thickness. Examples of coating methods include spin coating, roll coating, curtain coating, flow coating, printing, microgravure coating, gravure coating, wire bar coating, dip coating, spray coating, and meniscus coating.

[0089] The organic solvent can be removed by drying, for example, air drying at room temperature, drying on a hot plate, drying in a drying oven, or blowing warm or hot air. The conditions for removing the organic solvent are not particularly limited; drying may be performed until the organic solvent is largely 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 undergone the drying process can be subjected to the polymerization process (curing process) without undergoing the heat treatment process described above. However, to achieve a more uniform orientation of the liquid crystal molecules in the coating layer, it is preferable to heat the coating layer that has undergone the drying process to a liquid crystal phase expression temperature to align them in the liquid crystal state, and then fix the orientation by photopolymerization or thermal polymerization.

[0090] Furthermore, when composition (1) is used as a low dielectric loss tangent resin insulating film, it is also preferable to subject the substrate surface to an alignment treatment before application. Examples of alignment treatment methods include simply forming an alignment film on a substrate, forming an alignment film on the substrate and then rubbing it with a rayon cloth, directly rubbing the substrate with a rayon cloth, oblique deposition of silicon oxide, and rubbing-free alignment using a stretched film, a photoalignment film, or an ion beam. In some cases, the desired alignment state can be achieved without treating the substrate surface. For example, when forming homeotropic alignment, surface treatments such as rubbing are often not performed, but rubbing may be performed to achieve higher alignment.

[0091] The alignment film is not particularly limited as long as it can control the alignment of the composition (1), and known alignment films can be used, such as polyimide, polyamide, polyvinyl alcohol, alkylsilane, alkylamine, or lecithin-based alignment films. For vertical alignment, a silane coupling agent is also suitable.

[0092] Any method can be used for the rubbing treatment. Usually, a method is used in which a rubbing cloth made of a material such as rayon, cotton, or polyamide is wrapped around a metal roll or the like, and the roll is moved while rotating in contact with the substrate or the alignment film, or a method is used in which the substrate side is moved while the roll is fixed.

[0093] In order to obtain a more uniform alignment, an alignment control additive may be contained in the composition (1). Examples of such alignment 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 amine sulfates, 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 a perfluoroalkyl and a hydrophilic group, oligomers having a perfluoroalkyl and a lipophilic group, urethanes having a perfluoroalkyl, and organosilicon compounds having a primary amino group (for example, alkoxysilane-type, linear siloxane-type, and three-dimensionally condensed silsesquioxane-type organosilicon compounds).

[0094] Examples of the substrate 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 product, epoxy resin, phenolic resin, and norbornene resin; 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.

[0095] The film substrate may be a uniaxially stretched film or a biaxially stretched film. The film substrate may be previously subjected to a surface treatment such as saponification, corona treatment, or plasma treatment. A protective layer may be formed on the film substrate to prevent the film from being corroded by the organic solvent contained in the composition (1). Examples of materials used for the protective layer include polyvinyl alcohol. Furthermore, an anchor coat layer may be formed to enhance adhesion between the protective layer and the substrate. Such an anchor coat layer may be made of either an inorganic or organic material, as long as it enhances adhesion between the protective layer and the substrate.

[0096] 12) Low dielectric loss tangent resin parts and electronic devices The low dielectric loss tangent resin-forming composition of the present invention can be used as low dielectric loss tangent resin parts such as low dielectric loss tangent resin insulating films, low dielectric loss tangent resin films, low dielectric loss tangent resin sheets, etc. Furthermore, it is useful for applications in various electronic devices such as low dielectric loss tangent resin substrates, low dielectric loss tangent resin coatings, low dielectric loss tangent resin adhesives, and low dielectric loss tangent resin molded products.

[0097] 13) High Thermal Conductivity Resin Insulating Film, High Thermal Conductivity Resin Film, and High Thermal Conductivity Resin Sheet The polymer molded article of the present invention is a cured product of the low dielectric loss tangent resin-forming composition comprising the composition (1) described above, but also possesses the properties of a high thermal conductivity resin. It is a molded article of a low dielectric loss tangent and high thermal conductivity resin, and can be used as a thin-film low dielectric loss tangent, high thermal conductivity resin insulating film. It can also be used as a film, sheet, plate, fiber, or three-dimensionally shaped part (insulating portion of a connector), or as a coating agent, adhesive, sealant, or filler. The polymer molded article of the present invention can also be used as a high thermal conductivity resin that does not require a low dielectric loss tangent, and is useful as a high thermal conductivity insulating resin, such as a heat dissipation sheet sandwiched between a substrate, adhesive sheet, adhesive, sealant, filler, or heat sink for a semiconductor element with a high heat generation. Furthermore, since it also has transparency to visible light, it can be used, for example, as an encapsulant for high-power LEDs that require transparency and heat dissipation, as a binder for dispersing phosphors, as a protective layer for light-emitting elements, and as a transparent resin part for directing heat generated in internal elements of micro LEDs and organic EL displays to the outside. Because the polymer molded article of the present invention is a photocurable or thermosetting resin, it has the above-mentioned characteristics while also being excellent in micro-processability and low-temperature processability, and is useful, for example, for optical modulators formed on a micron scale and optical connection paths.

[0098] [Production Method] Hereinafter, a method for producing a low dielectric loss tangent resin-forming composition and a method for producing a low dielectric loss tangent resin part from the composition will be specifically described.

[0099] The low dielectric loss tangent resin-forming composition of the present invention can be used as a liquid resin raw material in a temperature range where a liquid crystal phase or an isotropic phase is exhibited, or it can be dissolved in an organic solvent and used as a solution. The low dielectric loss tangent resin-forming composition is prepared by adding the polymerizable liquid crystal compound (1), an organic solvent, an inorganic filler, and the various additives described above, as needed, and stirring and degassing the mixture using a stirrer until the composition is uniform. For example, using a rotation / revolution mixer, the mixture is stirred at 2000 rpm for 10 minutes, and then degassed at 2200 rpm for 10 minutes. In addition to the rotation / revolution mixer, dispersion can be performed using a stirring motor, a crusher, a three-roll mill, a ball mill, a rotation / revolution mill, a planetary mill, a bead mill, a jet mill, or the like.

[0100] As a coating method, a wet coating method is preferably used to uniformly coat the low dielectric loss tangent resin-forming composition. Among wet coating methods, spin coating, which allows for simple and uniform film formation, is preferred when producing a small number of low dielectric loss tangent resin parts. When productivity is important, 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 printing, flexographic printing, screen printing, rod coating, and the like are preferred. The wet coating method can be appropriately selected from these methods depending on the required film thickness, viscosity, curing conditions, and the like.

[0101] When producing a sheet, a cast molding method can be used in which the composition is coated onto a release-treated substrate using the above-mentioned method or the like and then peeled off, and when producing a three-dimensional structure, a mold can be used as needed, and resin molding methods such as press molding, compression molding, transfer molding, and various 3D printer molding methods (ejection lamination methods) can be used. After molding, the mold can be removed and the mold can be fully cured, or the molded product can be fully cured while still in the mold, or in the case of a molding method that does not use a mold, the molded product can be fully cured as is.

[0102] The present invention will be explained in more detail with reference to examples (including preparation examples of compounds, compositions, polymers, low dielectric loss tangent resins, etc.), but the present invention is not limited to these examples.

[0103] [Synthesis Example of Compound (1)] Compound (1) was synthesized according to the procedures shown in 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 device characteristics of compound (1), the composition, the polymer, the low dielectric loss tangent resin, etc. were measured by the following methods.

[0104] <NMR Analysis> Measurement was performed using JNM-ECZR manufactured by JEOL Ltd. １ For H-NMR measurements, the sample was ３ The sample was dissolved in a deuterated solvent such as tetramethylsilane, and the measurement was carried out at room temperature, 500 MHz, and 16 accumulations. Tetramethylsilane was used as an internal standard. １９ In the F-NMR measurement, CFCl ３ was used as an internal standard, and the accumulation was performed under the condition of 32 times. In the explanation of the nuclear magnetic resonance spectrum, 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.

[0105] <Gas Chromatography Analysis> A GC-2014 gas chromatograph manufactured by Shimadzu Corporation was used for the measurements. The column used was a capillary column DB-1 (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 vaporizer was set to 300°C, and the temperature of the detector (FID) was set to 300°C. The sample was dissolved in an appropriate solvent such as acetone to prepare a 1 wt% solution, and 1 μl of the resulting solution was injected into the sample vaporizer. A GCSolution system manufactured by Shimadzu Corporation was used as the recorder.

[0106] <HPLC Analysis> A Prominence (LC-20AD; SPD-20A) manufactured by Shimadzu Corporation was used for the measurements. A YMC-Pack ODS-A (length 150 mm, inner diameter 4.6 mm, particle size 5 μm) manufactured by YMC Corporation was used as the column. An appropriate mixture of methanol / pure water or acetonitrile / pure water was used as the eluent. A UV detector, RI detector, CORONA detector, or other detector was used as appropriate. When using a UV detector, 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.

[0107] <Ultraviolet-visible spectroscopic analysis> Measurements were performed using a PharmaSpec UV-1700 manufactured by Shimadzu Corporation. The detection wavelength was 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 (light path length 1 cm) and measured.

[0108] <Measurement Sample> When measuring the transition temperature (clearing point, melting point, polymerization initiation temperature, etc.) and, when the compound exhibits a liquid crystal phase, the phase structure, the compound itself was used as a sample.

[0109] (1) Transition temperature (°C) Measurements were performed using a high-sensitivity differential scanning calorimeter, X-DSC7000, manufactured by Hitachi High-Tech Science Corporation (formerly SII Nanotechnology Corporation). The sample was heated and cooled at a rate of 3-5°C / min, and the onset of the endothermic or exothermic peak associated with the phase change of the sample was extrapolated to determine the transition temperature. The melting point and polymerization initiation temperature of the compound were also measured using this device. When a compound exhibits a liquid crystal phase, the temperature at which the solid transitions to a liquid crystal phase such as a 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 a crystal to a liquid is sometimes abbreviated as the "clearing point."

[0110] Crystals were represented as C. When the type of crystal could be distinguished, they were represented as C1, C2, etc. When a liquid crystal phase was present, the smectic phase was represented as S and the nematic phase as N. When the smectic phase could be distinguished into smectic A, smectic B, smectic C, or smectic F, they were represented as SA, SB, SC, or SF, respectively. Liquid (isotropic phase) was represented as I. The transition temperature was represented as, for example, "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.

[0111] (2) Phase Structure When a compound exhibits a liquid crystal phase, a sample was placed on a hot plate of a melting point measuring device equipped with a polarizing microscope (Mettler Toledo FP-52 hot stage). The sample was heated at a rate of 3°C / min, and the phase state and its change were observed under the polarizing microscope to identify the type of phase.

[0112] [Synthesis Example 1] Compound (S01: Compound (1-3) in which R １ａ and R １ｂ are both represented by formula (PG-1), R ｂ is hydrogen, q=0, Z １ Ga-(CH ２ ) ｂ O-, Z ２ is a single bond, Z ４ -O(CH ２ ) ｂ -, b=4, n=2, Compound in which X at positions 3 and 5 are all methyl)

[0113] (First step) Under a nitrogen atmosphere, 6-bromo-1-hexene (65.1 g, 399.3 mmol) was added to a solution of 3,3',5,5'-tetramethyl-1,1'-biphenyl-4,4'-diol (S01-a) (31.0 g, 127.9 mmol), potassium carbonate (55.9 g, 404.4 mmol), and tetrabutylammonium bromide (TBAB) (16.4 g, 50.9 mmol) in N,N-dimethylformamide (310 mL), and the mixture was stirred for 14 hours at 60°C. The reaction solution was poured into pure water and extracted with toluene (800 mL). The mixture was washed twice with pure water and once with saturated brine, and the organic layer was then concentrated under reduced pressure at 40°C. The resulting residue was subjected to silica gel column chromatography (solvent: heptane / ethyl acetate = 9 / 1 (volume ratio)) to isolate the product, which was then recrystallized from ethanol to obtain compound (S01-b) (39.7 g, 97.6 mmol).

[0114] (Step 2) Under a nitrogen atmosphere, metachloroperbenzoic acid (mCPBA) (65 wt%) (56.0 g, 211.1 mmol) was added in small portions to a solution of compound (S01-b) (29.0 g, 71.3 mmol) in dichloromethane (400 mL) under ice-cooling, and the mixture was stirred overnight while returning to room temperature. The reaction mixture was poured into saturated aqueous sodium thiosulfate, and the insoluble matter was filtered off. The aqueous layer was extracted with dichloromethane (600 mL). The combined organic layer was washed twice with saturated aqueous sodium thiosulfate, three times with saturated aqueous sodium bicarbonate, and once with saturated brine, and then concentrated under reduced pressure at 40 °C. The resulting residue was purified by silica gel column chromatography (solvent: toluene / ethyl acetate = 9 / 1 (volume ratio)) to isolate the product. Recrystallization from toluene / ethanol = 1 / 5 (volume ratio) yielded compound (S01) (19.6 g, 44.8 mmol). The transition point of this compound (S01) was C 101.0 I (°C). The polymerization initiation temperature was 159°C. １ The H-NMR signals were as follows: δ (ppm; CDCl ３): 7.18 (s, 4H), 3.81-3.79 (t, 4H), 2.99-2.96 (m, 2H), 2.80-2.78 (dd, 2H) , 2.52-2.51 (dd, 2H), 2.32 (s, 12H), 1.92-1.86 (m, 4H), 1.76-1.60 (m, 8H).

[0115] Example 1 Preparation of Sample for Measuring Dielectric Properties (Dielectric Constant and Dielectric Loss Tangent) 0.877 g of polymerizable compound (S01) as compound (1) and 0.395 g of 4,4'-methylenedianiline (DDM, manufactured by Tokyo Chemical Industry Co., Ltd.) as a curing agent were placed in an aluminum cup and placed on a hot plate set to 120°C. The mixture was mixed with a spatula for 5 minutes to dissolve the curing agent into the molten compound (S01) and partially react with it, to obtain a mixture for measuring dielectric properties. This mixture was returned to room temperature, and a 15 cm square, 0.3 mm thick PTFE sheet was used as a release sheet, as shown in Figure 1, and a 10 cm square, 0.2 mm thick PTFE sheet with a 7 cm diameter through-hole drilled in the center was used as a mold. 0.5 g of the mixture was placed in the center of the 7 cm mold, sandwiched between the opposing PTFE release sheets, and then sandwiched between 15 mm square, 3 mm thick aluminum plates. This laminate was sandwiched between the hot plates of an Imoto Manufacturing IMC-482E manual hydraulic vacuum heating press, and the pressure was reduced to 0.1 MPa or less using a dry pump. The hot plates were then heated to 120°C. After the resin components softened, the pressure was increased to 1 MPa and the laminate was molded at 200°C for 1 hour while still under pressure. The pressure was then removed and the laminate was cured for an additional 3 hours. After curing, the laminate was allowed to return to room temperature, yielding a 7 cm square sample. The sample for measuring dielectric properties was cut into 3 mm wide strips measuring 3 mm x 70 mm using a cutter knife. The remaining cut portion was used as the sample for measuring thermal diffusivity.

[0116] <Method for Evaluating Dielectric Properties (Relative Permittivity and Dielectric Loss Tangent)> The resonant frequency shift and attenuation of the dielectric property measurement sample were measured using a cavity resonator (TM mode 10 GHz) manufactured by AET, INC. connected to a vector network analyzer (MS46522B-043 manufactured by Anritsu Corporation), and the dielectric properties of the relative permittivity and dielectric loss tangent (tan δ) were calculated using the company's software. Because film thickness significantly affects measurement accuracy, the thickness and width of the prepared sample were measured at five points using a Mitutoyo Digimatic Micrometer, and the average values ​​were used for calculation. To minimize the influence of moisture content in the sample, the sample was left in a desiccator overnight. On the day of measurement, the sample was left to stand for at least 60 minutes in a laboratory at 20°C and 48% RH before starting the measurement.

[0117] <Method for evaluating heat dissipation (thermal diffusivity)> The heat dissipation (thermal diffusivity) in the thickness direction of the remaining sample after cutting out the strips for measuring dielectric properties was measured using a thermal diffusivity measuring device, Model I, manufactured by AiPhase Corporation.

[0118] [Example 2] A sample was prepared and evaluated in the same manner as in Example 1, except that the polymerizable compound (S01) was used as is and 4,4'-ethylenedianiline (DDE, manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the curing agent. The results are shown as Example 2.

[0119] [Example 3] A sample was prepared and evaluated in the same manner as in Example 1, except that the polymerizable compound (S01) was used as it was, 4,4'-dihydroxylbiphenyl (BPDO: manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the curing agent, and 2-ethyl-4-methylimidazole was added as a curing catalyst in an amount of 3% by weight of the resin component. The result is set forth as Example 3.

[0120] A sample was prepared and evaluated in the same manner as in Example 3, except that the polymerizable compound (S01) was used as is and 3,3′,5,5′-tetramethyl-1,1′-biphenyl-4,4′-diol (TMBPDO) was used as the curing agent. The results are shown in Example 4.

[0121] Example 5 A sample was prepared and evaluated in the same manner as in Example 1, except that the polymerizable compound (S01) was used as is, the active ester-based curing agent EPICLON (registered trademark) HPC-8000-65T (manufactured by DIC Corporation) was used as the curing agent, and 3% by weight of a phosphorus-based curing accelerator (manufactured by Hokko Chemical Industry Co., Ltd., product name TBP-3S) was added to the resin component. Note that since the active ester-based curing agent contains 65% by weight of toluene as a solvent, the solvent was removed using a vacuum dryer before use. The results are referred to as Example 5.

[0122] Reference Example 1 A sample was prepared and evaluated in the same manner as in Example 2, except that compound (S02) was used as the polymerizable compound. The results are shown as Reference Example 1. Compound (S02) was synthesized by the following method, similar to compound (S01). Reference Example 1 is an example of a composition for forming a low dielectric loss tangent resin that uses "another polymerizable liquid crystal compound" other than compound (1) used in the present invention.

[0123] A sample was prepared and evaluated in the same manner as in Example 2, except that the following biphenyl-based epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name jER (registered trademark) YX4000) was used as the polymerizable compound. The result is designated as Comparative Example 1.

[0124] A sample was prepared and evaluated in the same manner as in Example 2, except that the following bisphenol F epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name jER (registered trademark) 807) was used as the polymerizable compound. The result is shown as Comparative Example 2.

[0125] [Comparison of Dielectric Properties] The dielectric properties at 10 GHz of Example 2, Reference Example 1, and Comparative Examples 1 and 2 are shown in Table 1. The dielectric properties at 10 GHz of Examples 1 to 5 are shown in Table 2. Table 1 Dielectric properties when the curing agent is DDE

[0126] Table 2 Dielectric properties when polymerizable compounds are aligned with compound (S01)

[0127] Table 1 shows that Example 2, Reference Example 1, Comparative Example 1, and Comparative Example 2, which use the highly linear diamine DDE as the curing agent, have the lowest dielectric properties (dielectric constant and dielectric dissipation factor), with the dielectric dissipation factor being particularly low. Therefore, by using compound (S01) as the compound (1) used in the present invention, it is possible to form a resin composition with low dielectric loss. Furthermore, Table 2 shows that Examples 1 to 5 show the lowest dielectric properties when an active ester curing agent is used. Furthermore, when comparing Examples 1 and 2, which use amine curing agents consisting of two phenylene rings, it is clear that Example 2, which uses a highly linear biphenyl and an even number of phenylene rings, i.e., a highly linear DDE, has poorer dielectric properties. This is thought to be because, even with the same polymerizable group, a curing agent with a more linear structure results in higher crystallinity in the cured product, suppressing molecular vibrations that cause dielectric dissipation factors due to crystallization energy. Active ester curing agents, which have attracted attention as low-dielectric epoxy resins, have even better dielectric properties than conventional diamine or phenolic curing agents. However, there are trade-offs, such as the need for a longer curing time, so it is important to select the curing agent according to the purpose.

[0128] The thermal diffusivities of Example 2, Reference Example 1, and Comparative Examples 1 and 2 are shown in Table 3. The thermal diffusivities of Examples 1 to 5 are shown in Table 4. Table 3: Thermal diffusivities when the curing agent is DDE

[0129] Table 4 Dielectric properties when polymerizable compounds are aligned with compound (S01)

[0130] Table 3 shows that comparing Example 2, Reference Example 1, Comparative Example 1, and Comparative Example 2, which use DDE, a highly linear diamine, as a curing agent, biphenyl-based compounds have higher crystallinity and thermal diffusivity than those using conventional bisphenol-type epoxy compounds. When comparing biphenyl-based compounds, the difference is smaller than that of Comparative Example 2. However, when comparing Example 2 and Comparative Example 1, Example 2 has a higher thermal diffusivity. This is thought to be because the polymerizable compound (S01) used as compound (1) in the present invention has a longer molecular length, resulting in fewer polymerized portions that cause phonon scattering. Furthermore, when comparing compounds (S01) and (S02) of the same length, they have nearly identical thermal diffusivities. Despite concerns that the introduction of methyl groups might disperse the propagation of phonon vibrations, it can be said that this effect is almost nonexistent. This is thought to be because phonon vibrations propagate along the long axis of the molecular chain, and the introduction of symmetric side chains of the same mass at positions symmetrical to that axis minimizes phonon conduction loss. Furthermore, Table 4 shows that the thermal diffusivity was highest when a biphenyl diol with a rigid mesogen moiety (Example 3) was used, followed by the biphenyl with a methyl group (Example 4). DDE (Example 2), which has a linear structure with ethylene between the phenylene rings, had a lower thermal diffusivity than Example 4, and DDM (Example 1), which has a bent structure with methylene between the phenylene rings, had an even lower thermal diffusivity than Example 2. Furthermore, the active ester curing agent (Example 5), which has many active ester moieties and low linearity, does not have a structure designed with phonon conduction in mind, and therefore the thermal diffusivity of Example 5 was the lowest. These results indicate that by using the polymerizable compound (S01) as the compound (1) used in the present invention, an epoxy-based polymerizable composition with excellent low dielectric properties can be formed. When the curing agent has high linearity, a composition having both high thermal conductivity and low dielectric properties can be formed. Furthermore, when a curing agent having a polymerizable group with low dielectric properties is used, a composition with even lower dielectric properties can be formed.

[0131] Example 6 Method for Evaluating the Thermal Diffusivity of a Composite Material with an Inorganic (Heat-Dissipating) Filler To confirm its performance as a high thermal conductive material, a sample composited with an inorganic (heat-dissipating) filler was prepared. 4.50 g of boron nitride powder (manufactured by Momentive, product name: PolarTherm PTX-25), 1.05 g of polymerizable compound (S01), and 1.09 g of DDE as a curing agent were placed in a mortar and mixed well. The mixture was then placed on a hot plate set to 120°C. After the polymerizable compound (S01) had melted into a liquid, the mixture was stirred with the inorganic (heat-dissipating) filler for 5 minutes while dissolving the curing agent. The mixture was cured at 200°C for 1 hour using the same jig and press as in Example 1, and a sheet for measuring thermal diffusivity was prepared.

[0132] A sample was prepared in the same manner as in Example 6, except that a biphenyl-based epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name jER (registered trademark) YX4000) was used as the polymerizable compound, and the heat dissipation property (thermal diffusivity) was measured. The result is shown as Comparative Example 3.

[0133] Comparative Example 4 A sample was prepared in the same manner as in Example 6, except that a bisphenol F epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name jER (registered trademark) 807) was used as the polymerizable compound, and the heat dissipation property (thermal diffusivity) was measured. The result is shown as Comparative Example 4. The measurement results of the heat dissipation property (thermal diffusivity) of Example 6 and Comparative Examples 3 and 4 are shown in Table 5.

[0134] Table 5. Heat dissipation properties (thermal diffusivity) of composite materials of polymerizable compounds and boron nitride

[0135] Table 5 shows that even when composited with boron nitride, Example 6 exhibits improved thermal diffusivity compared to Comparative Examples 3 and 4. Both compound (S01) as compound (1) used in the present invention and boron nitride tend to orient in the plane direction of the sheet when pressed under pressure. Compared to Comparative Example 3, compound (S01) of Example 6 has six more carbon atoms and therefore a higher thermal diffusivity in the major axis direction. Therefore, based on the measurement results in Table 5, which measured thermal diffusivity in the thickness direction, it can be expected that the difference in thermal diffusivity between Example 6 and Comparative Example 3 will be even greater. These results demonstrate that compound (1) used in the present invention has better dielectric properties and heat dissipation (thermal diffusivity) than simple biphenyl compounds.

[0136] <Composite Material of Polymerizable Compound (S01) and Other Epoxy Compounds> When actually using the polymerizable compound (S01), it is expected that it will be mixed with an epoxy compound other than compound (S01) to adjust the viscosity before curing and the electrical and mechanical properties after curing. To investigate the effects of this, an epoxy compound other than compound (S01) was mixed with compound (S01), and the dielectric properties after curing were evaluated. [Example 7] Polymerizable compound (S01) was used as compound (1), and the same active ester-based curing agent (EPICLON (registered trademark) HPC-8000-65T (manufactured by DIC Corporation)) as in Example 5 was used as the curing agent. Since the active ester-based curing agent contains 65 wt% toluene as a solvent, the solvent was removed using a vacuum dryer before use. The purity of compound (S01) was determined to be 99% by weight or more by high-performance liquid chromatography. Therefore, the epoxy equivalent was set to 220, and 0.388 g of compound (S01) and 0.346 g of HPC-8000-65T were weighed out to a 1:1 equivalent with the active ester curing agent, and placed in a 20 mL screw bottle. This screw bottle was heated to 120°C using a dry bath, and the resin components were melted and stirred using a stainless steel spatula. Finally, 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 mixed. Before the paste solidified upon cooling, it was spread on the center of a PTFE release sheet using the spatula used for stirring. The curing time was 2 hours; otherwise, a sample was prepared and evaluated in the same manner as in Example 1. The resin composition of this sample was the same as in Example 5, but the curing accelerator and curing conditions were different, so it was designated Example 7.

[0137] Reference Example 2 Using compound (S02) as a polymerizable compound, a commercially available epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name jER (registered trademark) YL6121HA), and HPC-8000-65T as a curing agent, each compound was weighed out so that the equivalent ratio was 1:1:2, and a sample was prepared and evaluated in the same manner as in Example 7. The results are shown as Reference Example 2. YL6121HA is a mixture of the aforementioned YX4000 and a compound of YX4000 in which a methyl group is not attached to the biphenyl ring, in an approximately 1:1 equivalent ratio.

[0138] Example 8 A sample was prepared and evaluated in the same manner as in Reference Example 2, except that the compound (S02) in Reference Example 2 was changed to the compound (S01).

[0139] Synthesis Example 3 To investigate the effect of the methyl group substituted on the benzene ring, compound (S03) was synthesized by the following method similar to compound (S01). Compound (S03-c) can be derived from compound (S03-a) by Suzuki coupling, a general organic chemical synthesis method, and a deprotection reaction. Then, compound (S03) (29.7 g, 75.0 mmol) was synthesized from compound (S03-c) (20 g, 100 mmol) by the same method as in Synthesis Example 1. Compound １ The H-NMR signals were as follows: δ (ppm; CDCl ３ ): 7.22-7.19 (d, 2H), 7.13-7.11 (d, 1H), 6.93-6.90 (d, 2H), 6.80 (s, 1H), 6.77-6.75 (d, 1H), 3.81-3.79 (t, 4H), 2.99-2.96 (m, 2H), 2.80-2.78 (dd, 2H), 2.52-2.51 (dd, 2H), 2.25 (s, 3H), 1.92-1.86 (m, 4H), 1.76-1.60 (m, 8H).

[0140] Example 9 A sample was prepared and evaluated in the same manner as in Example 7, except that the polymerizable compound (S01) was replaced with the compound (S03).

[0141] A sample was prepared and evaluated in the same manner as in Example 7, except that the compound (S01) in Example 7 was changed to jER (registered trademark) YL6121HA manufactured by Mitsubishi Chemical Corporation. The result is shown as Comparative Example 5.

[0142] A sample was prepared and evaluated in the same manner as in Example 7, except that the compound (S01) in Example 7 was changed to jER (registered trademark) 807 manufactured by Mitsubishi Chemical Corporation. The result is shown as Comparative Example 6.

[0143] The evaluation results of the dielectric properties of Example 7, Reference Example 2, Examples 8 and 9, and Comparative Examples 5 and 6 are shown in Table 6.

[0144] Table 6: Comparison of compound (S01) and compound (S03), and relative permittivity (Dk) and dielectric loss tangent (Df) when mixed with epoxy compounds other than those of the present invention

[0145] As shown in Table 6, when comparing compound (S03) and compound (S01) used in the present invention, compound (S01) exhibits slightly better dielectric properties. This is thought to be due to the fact that the more methyl groups there are, the more electrons in the biphenyl skeleton tend to localize to a degree that does not affect the dielectric constant in this frequency range, and the flatter molecular structure suppresses molecular rotational motion. Furthermore, compound (S01) used in the present invention can be used in combination with commercially available polymerizable compounds such as epoxy resins. In particular, it has been found that mixing compound (S01) with a biphenyl-skeleton epoxy compound with a short chain length similar in structure to compound (S01) or compound (S02) can potentially lower the dielectric constant and dielectric loss tangent compared to using each compound alone. While a longer molecular chain is necessary when thermal conductivity is important, this is an effective method when low dielectric constant, dielectric loss tangent, melting temperature, and viscosity are required.

[0146] The low dielectric loss tangent resin-forming composition of the present invention can be used as various electronic components, such as electronic substrates for high-frequency devices that require low dielectric loss, semiconductor package components, and high-frequency antenna components. It is particularly suitable for use in the periphery of semiconductor components that generate a large amount of heat and require heat dissipation. It can also be used as a heat dissipation component in low-frequency devices that do not require low dielectric loss, and is suitable for use in the periphery of light-emitting elements and display elements that require transparency. Furthermore, various electronic components obtained using the low dielectric loss tangent resin-forming composition of the present invention are useful for use as various electronic devices of the present invention.

[0147] 11 15 cm x 15 cm, 0.3 mm thick PTFE sheet 12 10 cm x 10 cm, 0.2 mm thick PTFE sheet 13 7 cm diameter through-hole 14 Mixture for measuring dielectric properties (0.5 g)

Claims

1. A composition for forming a low dielectric loss tangent resin, which contains a liquid crystalline compound having a polymerizable group at its terminal, represented by formula (1), and when the composition is cured without adding an inorganic filler, the cured product has a dielectric loss tangent at 10 GHz of less than 0.

02. In formula (1), A １ is a group selected from ring structures represented by the following formulae (R1-1) to (R1-8), In formulae (R1-1) to (R1-8), X １ is halogen or alkyl having 1 to 6 carbon atoms, and in the formula, X １ When there are a plurality of A's, they may be the same or different, ２ and A ３ are independently 1,4-phenylene, in which at least one hydrogen may be replaced by halogen or alkyl having 1 to 6 carbon atoms in which at least one hydrogen may be replaced by halogen; Z １ and Z ４ are independently alkylene having 2 to 20 carbon atoms; and in the alkylene having 3 to 20 carbon atoms, at least one —CH ２ - may be replaced by -O-, Z ２ and Z ３ are independently a single bond or an alkylene having 1 to 20 carbon atoms; in this alkylene, at least one —CH ２ - may be replaced by -O-, p is 0 or 1, R １ａ and R １ｂ are independently a group selected from the polymerizable groups represented by formula (PG-1), In formula (PG-1), R ｂ represents hydrogen, halogen, -CF ３ or alkyl having 1 to 5 carbon atoms, and q is 0 or 1.

2. In formula (1), R １ａ and R １ｂ are the same polymerizable group represented by formula (PG-1).

3. A composition for forming a low dielectric tangent resin according to claim 1, wherein the liquid crystal compound having a polymerizable group at its end and represented by formula (1) has a melting point of 104°C or less or a transition temperature from a crystalline phase to a nematic phase of 104°C or less.

4. The composition for forming a low dielectric loss tangent resin according to claim 1, which contains at least one liquid crystalline compound having a polymerizable group at its terminal, represented by formulas (1-1) to (1-3). In formulas (1-1) to (1-3), Z １ and Z ４ are independently -(CH ２ ) ａ -, -O(CH ２ ) ｂ -, -(CH ２ ) ｂ O-, or -O(CH ２ ) ｃ O—, where a is an integer from 2 to 12, b is an integer from 2 to 11, and c is an integer from 1 to 10; Z ２ is a single bond, -(CH ２ ) ａ -, -O(CH ２ ) ｂ -, -(CH ２ ) ｂ O-, or -O(CH ２ ) ｃ O-, wherein a is an integer of 1 to 12, b is an integer of 1 to 11, and c is an integer of 1 to 10, X is fluorine or methyl, Me is methyl, n is an integer of 0 to 4, including when n is 2 or more, and when there are multiple Xs in the formula, they may be the same or different, and R １ａ and R １ｂ are independently a polymerizable group represented by formula (PG-1), In formula (PG-1), R ｂ represents hydrogen, halogen, -CF ３ or alkyl having 1 to 5 carbon atoms, and q is 0 or 1.

5. In formula (1), R １ａ and R １ｂ are the same polymerizable group represented by formula (PG-1), and in formula (PG-1), R ｂ The low dielectric loss tangent resin-forming composition according to claim 1 , wherein: is hydrogen, and q is 0.

6. The composition for forming a low dielectric loss tangent resin according to claim 1, comprising at least one selected from the following (A) and (B): (A) a polymer of a liquid crystal compound having a polymerizable group at its terminal, represented by formula (1); and (B) a polymerizable compound other than the liquid crystal compound having a polymerizable group at its terminal, represented by formula (1).

7. The composition for forming a low dielectric loss tangent resin according to claim 1, which contains a di- to tetra-functional curing agent having a linear molecular structure.

8. A composition for forming a low dielectric tangent resin according to claim 1, which contains an inorganic filler, and wherein the thermal conductivity of the cured product obtained by curing the composition is 1 W / m·K or more.

9. A composition for forming a low dielectric tangent resin according to claim 1, which contains an inorganic filler that is a nitride filler, and the thermal conductivity of the cured product obtained by curing the composition is 10 W / m·K or more.

10. A low dielectric loss tangent resin-forming composition according to claim 8, wherein the inorganic filler is at least one selected from the group consisting of silicon oxide compounds such as spherical silica, pulverized silica, hollow silica and fumed silica, metal nitrides such as aluminum nitride, boron nitride and silicon nitride, diamond, graphite, silicon carbide, and metal oxides such as magnesium oxide, aluminum oxide, zinc oxide, titanium oxide, tin oxide and calcium oxide.

11. A composition for forming a low dielectric loss tangent resin according to claim 1, which contains a fibrous heat-dissipating filler, wherein the fibrous heat-dissipating filler is at least one selected from the group consisting of carbon fiber, carbon nanotube, polyamide fiber, aramid fiber, polyparaphenylene benzobisoxazole fiber, liquid crystalline polyester fiber, silicate whisker, alumina whisker, magnesium oxide whisker, zinc oxide whisker, aluminum nitride whisker, and cellulose nanofiber.

12. A low dielectric loss tangent resin insulating film, which is a polymer molded product obtained by curing the low dielectric loss tangent resin-forming composition according to claim 1 with heat or ultraviolet light.

13. A low dielectric loss tangent resin film or a low dielectric loss tangent resin sheet, which is a polymer molded product obtained by curing the low dielectric loss tangent resin composition according to claim 1 with heat or ultraviolet light.

14. A low dielectric loss tangent resin part which is a polymer molded product obtained by curing the low dielectric loss tangent resin-forming composition according to claim 1 with heat or ultraviolet light.

15. An electronic device using the polymer molded body according to any one of claims 12 to 14.

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