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

Abstract

The purpose of the present invention is to achieve a composition for forming a low dielectric constant resin which is suitable for use in a substrate for radar, next-generation communication devices and the like using higher frequencies, while having high transmissivity.　The present invention enables the achievement of a polymerizable composition, which is able to be molded by a solution process by curing a polymerizable cyclobutane ring compound that has less conjugates or polar groups, and exhibits high linearity or symmetry of each molecule, and which exhibits transmissivity and low dielectric properties lower than those of conventional liquid crystal polymers.

Description

Composition for forming low dielectric constant resin, low dielectric constant resin part, and electronic device using same

[0001] The present invention relates to a composition for forming a low dielectric constant resin using a compound having a polymerizable group, and a low dielectric constant resin part using the composition. In particular, the present invention relates to a material for a high frequency substrate and its peripheral materials, and a low dielectric constant resin part and an electronic device using the same.

[0002] In recent years, with the shift to 5G and beyond 5G and 6G in communication devices, there has been an ever-increasing demand for lower dielectric constants and lower loss in resin materials used in semiconductor components and electronic circuit parts. In particular, with 6G communication, frequencies are expected to increase to 0.1 THz and higher, requiring materials that can transmit electrical signals quickly and with low loss even in higher frequency ranges. Furthermore, even with materials such as light-receiving window materials that previously allowed electromagnetic waves to pass through without any problems, materials that become less transparent as wavelengths become shorter are emerging, making electromagnetic wave transmittance an important parameter.

[0003] Many attempts have been made to introduce alicyclic rings into the molecular chain as a method for lowering the dielectric constant of resins, and resins containing cyclohexane rings (Patent Document 1), dicyclohexane rings (Patent Document 2), adamantane rings (Patent Document 3), and norbornene rings (Patent Document 4) in the molecular chain have been developed. However, when an alicyclic ring is incorporated into the main skeleton, the resin layer often becomes brittle, resulting in a loss of flexibility. Furthermore, alicyclic rings can prevent coloration due to light absorption caused by electron conjugation in aromatic rings, and are widely used, for example, to make polyimides transparent (Patent Document 5).

[0004] Although the cyclobutane ring, a type of alicyclic ring, has been applied to a smaller extent than the cyclohexane ring, it has been used to reduce the refractive index of polycarbonate (Patent Document 6) and to make polyimide transparent (Patent Document 7), and since the square of the refractive index is proportional to the dielectric constant, it is also expected to be used as a low-dielectric-constant material. Furthermore, a method for synthesizing polycarbonates with high durability and transparency by controlling the ratio of cis- and trans-isomers of the cyclobutane ring is also being investigated (Patent Document 8).

[0005] Japanese Patent Application Laid-Open No. 2004-359941 International Publication No. 2022 / 092063 Japanese Patent Application Laid-Open No. 2005-206834 Japanese Patent Application Laid-Open No. 6-206985 Japanese Patent Application Laid-Open No. 7-26017 International Publication No. 2020 / 122122 Japanese Patent Application Laid-Open No. 3-153786 Japanese Patent Application Laid-Open No. 2019-172796

[0006] As described above, an object of the present invention is to provide a highly permeable, low dielectric constant resin-forming composition that can be suitably used for insulating resin parts of components constituting next-generation communication devices that are becoming increasingly high-frequency, surface protection layers of radar transmitting and receiving elements, and the like.

[0007] The present inventors have discovered that by curing a polymerizable compound having a cyclobutane ring (hereinafter sometimes referred to as a cyclobutane polymerizable compound), which has few conjugated or polar groups and high molecular linearity and symmetry, it is possible to realize a polymerizable composition that can be molded by solution processing and exhibits lower dielectric properties and higher transmittance than conventional liquid crystal polymers, thereby completing the present invention. Furthermore, they have discovered that by adjusting the cis-trans isomer ratio of the cyclobutane ring, excellent dielectric properties can also be exhibited in the high frequency range, particularly in the millimeter wave range.

[0008] The present invention has the following features: [1] A composition for forming a low dielectric constant resin, which contains a cyclobutane ring compound represented by formula (1) having at least one 2,2,4,4-tetramethylcyclobutane ring and polymerizable groups at both ends, and which, when cured without adding an inorganic filler to the composition, produces a cured product with a relative dielectric constant of less than 2.7 at 10 GHz to 3 THz. In formula (1), A １ and A ２ are independently 2,2,4,4-tetramethylcyclobutane-1,3-diyl, 1,4-phenylene or 1,4-cyclohexylene, and in the 1,4-phenylene and 1,4-cyclohexylene rings, 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; A １ and A ２ At least one of the ring structures of Z is 2,2,4,4-tetramethylcyclobutane-1,3-diyl;１ , Z ２ , and Z ３ are independently a single bond or an alkylene having 1 to 20 carbon atoms, and in this alkylene, at least one —CH ２ - may be replaced by -O-, s is an integer of 0 to 6, P １ and P ２ are independently a group selected from the polymerizable groups represented by formulas (PG-1) to (PG-9), In formulas (PG-1) to (PG-5), R ｂ represents hydrogen, halogen, -CF ３ or alkyl having 1 to 5 carbon atoms, q is 0 or 1, ｂ When there are a plurality of, they may be the same or different.

[0009] [2] In formula (1), s is 0, 1 or 2, and P １ and P ２ are independently a polymerizable group represented by formula (PG-1), (PG-5), (PG-6), (PG-7), or (PG-8).

[0010] [3] In formula (1), s is 0 and P １ and P ２ are independently a polymerizable group represented by formula (PG-1), (PG-5), (PG-6), (PG-7), or (PG-8).

[0011] [4] The composition for forming a low dielectric constant resin according to [3], wherein the cyclobutane ring compound represented by formula (1) according to [1] contains 45% by weight or more of a cis-isomer.

[0012] [5] The composition for forming a low dielectric constant resin according to [3], wherein the cyclobutane ring compound represented by formula (1) according to [1] contains 60% by weight or more of a cis isomer.

[0013] [6] The composition for forming a low dielectric constant 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 cyclobutane ring compound represented by formula (1) according to [1], and (B) a polymerizable compound other than the cyclobutane ring compound represented by formula (1) according to [1].

[0014] [7] The composition for forming a low dielectric constant resin according to any one of [1] to [6], wherein the composition is cured to form a cured product having a thickness of 500 μm, and the cured product has a transmittance of 50% or more for electromagnetic waves of 0.5 to 1 THz.

[0015] [8] The low dielectric constant resin-forming composition according to any one of [1] to [6], which contains an inorganic filler, 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.

[0016] [9] The composition for forming a low dielectric constant resin according to any one of [1] to [6] and [8], which contains a fibrous reinforcing agent, wherein the fibrous reinforcing agent is at least one selected from the group consisting of carbon fiber, carbon nanotube, silicate whisker, alumina whisker, magnesium oxide whisker, zinc oxide whisker, aluminum nitride whisker, and cellulose nanofiber.

[0017]

[10] A low dielectric constant resin insulating film which is a polymer molded product obtained by curing the low dielectric constant resin-forming composition according to any one of [1] to [9] with heat or ultraviolet light.

[0018]

[11] A low dielectric constant resin film or a low dielectric constant resin sheet, which is a polymer molded product obtained by curing the low dielectric constant resin-forming composition according to any one of [1] to [9] with heat or ultraviolet light.

[0019]

[12] A low dielectric constant resin sheet, which is a polymer molded product obtained by curing the composition for forming a low dielectric constant resin according to any one of [1] to [7] with heat or ultraviolet light, has an electromagnetic wave transmittance of 25% or more at 1 THz in the case of a sheet having a thickness of 1 mm.

[0020]

[13] A low dielectric constant resin part which is a polymer molded product obtained by curing the low dielectric constant resin-forming composition according to any one of [1] to [9] with heat or ultraviolet light.

[0021]

[14] An electronic device using the polymer molded article according to any one of

[10] to

[13] .

[0022]

[15] The cyclobutane ring compound represented by formula (1) according to [1], wherein A １ is 2,2,4,4-tetramethylcyclobutane-1,3-diyl, and Z １ and Z ３ are independently alkylene having 1 to 20 carbon atoms; and in this alkylene, at least one —CH ２ - may be replaced by -O-, s is 0, and P １ and P ２ are independently a group selected from polymerizable groups represented by formulae (PG-1), (PG-5), (PG-6), (PG-7) and (PG-8).

[0023]

[16] The cyclobutane ring compound according to

[15] , which is a cyclobutane ring compound selected from the compounds represented by formulas (1-1-1) to (1-1-7): In the formulas (1-1-1) to (1-1-7), n is an integer of 1 to 16.

[0024] The low dielectric constant resin-forming composition of the present invention, which contains a highly linear cyclobutane polymerizable compound for use in low dielectric constant resin parts, has excellent low dielectric properties as well as excellent properties in at least one of permeability, coatability, transparency, chemical stability, heat resistance, hardness, and mechanical strength, and is therefore suitable for, for example, low dielectric circuit boards, low dielectric antenna substrates, low dielectric coatings, low dielectric adhesives, and the like.

[0025] The following provides a detailed description of the present invention's low-dielectric-constant resin-forming composition, compound, low-dielectric-constant resin insulating film, low-dielectric-constant resin sheet, and low-dielectric-constant resin component, which are polymer molded articles of low-dielectric-constant resins obtained by curing the composition with heat or ultraviolet light, as well as electronic devices using the polymer molded articles, and methods for manufacturing these. The terms used in this specification are used as follows. "Liquid crystal compound" is a general term for compounds having 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 specific to liquid crystals, such as dielectric anisotropy, refractive index anisotropy, and magnetic susceptibility anisotropy, and are useful as components of liquid crystal compositions. Furthermore, "(meth)acryloyloxy" refers to acryloyloxy or methacryloyloxy, "(meth)acrylate" refers to acrylate or methacrylate, and "(meth)acrylic acid" refers to acrylic acid or methacrylic acid.

[0026] "At least one -CH in alkyl ２ The meaning of phrases such as "- may be replaced by -O-, -CO-, etc." is shown as an example. For example, C ４ H ９ At least one —CH ２ Examples of the group in which - is replaced by -O- or -CH=CH- include CH ７ O-, CH ３ -O-(CH ２ ) ２ -, CH ３ -O-CH ２ -O-, H ２ C=CH-(CH ２ ) ３ -, CH ３ -CH=CH-(CH ２ ) ２ -, CH ３ -CH=CH-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-CH２ --O-- is preferred.

[0027] The tetramethylcyclobutane ring is a cis-form when the substituent Z １ , Z ２ , and Z ３ The tetramethylcyclobutane ring is a trans isomer when two of the substituents Z １ , Z ２ , and Z ３ The two of them are on the opposite side of the ring plane (the formula on the right). １ , Z ２ The following diagram shows an example of the case.

[0028] "Compound (1)" means a compound represented by formula (1), and may also mean at least one compound represented by formula (1). The same applies to "compound (1-1)", and compounds (1-1) and (1-2) are collectively referred to as "compound (1)". "Composition (1)" means a composition containing at least one compound selected from the compounds (1). "Polymer (1)" is a polymer of a cyclobutane ring compound represented by formula (1), and means a polymer obtained by polymerizing the composition (1). One compound (1) contains a plurality of A ２ When any two A ２ may be the same or different. ２ When any two A ２ may be the same or different. This rule applies to Z ２ Ya, R ｂ This also applies to other symbols, groups, etc., such as , and q.

[0029] [Compound (1)] Compound (1) used in the present invention has a cyclobutane ring and a polymerizable group, and has high polymerization reactivity, high linearity and symmetry, good miscibility, etc. Compound (1) is a cyclobutane ring compound having at least one cyclobutane ring and two polymerizable groups. This compound (1) tends to become homogeneous when mixed with other polymerizable compounds.

[0030] Terminal group P of compound (1) １ or P ２ , ring structure A １ or A ２ and the bonding group Z １ , Z ２ , or Z ３ 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 described below.

[0031] <Terminal group P: P １ and P ２ ) Terminal group P of compound (1) １ and P ２ are independently a group selected from the polymerizable groups represented by formulae (PG-1) to (PG-9). In formulas (PG-1) to (PG-5), R ｂ represents hydrogen, halogen, -CF ３ or alkyl having 1 to 5 carbon atoms, q is 0 or 1, ｂ When there are a plurality of, they may be the same or different.

[0032] Preferred examples include polymerizable groups represented by formulae (PG-1a) to (PG-1d), (PG-2a), (PG-3a), (PG-4a), (PG-5a) to (PG-5d), and (PG-6) to (PG-9).

[0033] Among these preferred polymerizable groups, (PG-1a) to (PG-1d), (PG-2a), and (PG-4a) have an α,β-unsaturated ketone structure and can be polymerized by various means to produce a polymer having a larger molecular weight. (PG-3a) has a vinyl group adjacent to an electron-donating group and can be polymerized by various means to produce a polymer having a larger molecular weight. (PG-5a) to (PG-5d) have a strained cyclic ether and can be polymerized by various means to produce a polymer having a larger molecular weight. (PG-6) and (PG-9) do not have a polar group and therefore have small relative dielectric constants and dielectric dissipation factors.

[0034] The polymerizable groups represented by formulae (PG-1) to (PG-9) can be appropriately selected depending on the film production conditions. For example, when a film is produced by the commonly used photocuring method, acryloyloxy and methacryloyloxy groups represented by formula (PG-1) are preferred from the viewpoints of high curability, solubility in solvents, ease of handling, etc.

[0035] <Ring structure A: A １ and A ２ > A of compound (1) １ and A ２ are independently 2,2,4,4-tetramethylcyclobutane-1,3-diyl, 1,4-phenylene or 1,4-cyclohexylene, and in the 1,4-phenylene and 1,4-cyclohexylene rings, 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. １ and A ２ Preferred examples include 2,2,4,4-tetramethylcyclobutane-1,3-diyl, 1,4-cyclohexylene, 1,4-phenylene, 2-methyl-1,4-phenylene, 2,6-dimethyl-1,4-phenylene, and 2,3,6-trimethyl-1,4-phenylene. A particularly preferred example is 2,2,4,4-tetramethylcyclobutane-1,3-diyl. These stereoisomers may be a mixture of cis and trans stereoisomers.

[0036] The stereochemistry of 2,2,4,4-tetramethylcyclobutane-1,3-diyl is preferably cis rather than trans, and a mixture of cis-trans isomers containing a higher proportion of cis isomers is more preferred. Specifically, the cyclobutane ring compound (1-1) as compound (1) is preferably a cis-trans isomer mixture containing 45% by weight or more of cis isomers, and more preferably a cis-trans isomer mixture containing 60% by weight or more of cis isomers. In terms of dielectric properties (dielectric constant and dielectric dissipation factor), the upper limit of the cis-trans isomer mixture is preferably 99% by weight or less of cis isomers for applications requiring a low dielectric constant, more preferably 90% by weight or less of cis isomers, and even more preferably 80% by weight or less of cis isomers. Furthermore, for applications requiring a low dielectric dissipation factor (low tan δ), a cis-trans isomer mixture containing 100% by weight or less of the cis isomer is preferable, and a cis-trans isomer mixture containing 99% by weight or less of the cis isomer is more preferable. The trans configuration of 1,4-cyclohexylene is more preferable than the cis configuration. Since 2-fluoro-1,4-phenylene and 3-fluoro-1,4-phenylene are structurally identical, the latter is not exemplified. This rule also applies to the relationship between 2,5-difluoro-1,4-phenylene and 3,6-difluoro-1,4-phenylene.

[0037] 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. Preferred examples in which at least one hydrogen atom on the 1,4-phenylene ring may be replaced include fluorine, an alkyl having 1 to 6 carbon atoms, or -CF3, which lower the melting point and increase the solubility. Furthermore, the relative dielectric constant is low due to the small molecular polarizability. Furthermore, the dielectric loss is low due to the suppression of molecular motion.

[0038] When at least one ring is 1,4-cyclohexylene, the clearing point is high, the dielectric constant is very low, the dielectric loss is low, and the viscosity is small, and when at least two rings are 1,4-cyclohexylene, the clearing point is high, the dielectric constant is very low, the dielectric loss is low, and the viscosity is small.

[0039] When at least one ring in the ring structure A is 2,2,4,4-tetramethylcyclobutane-1,3-diyl, the dielectric constant is small and the dielectric loss tangent is small. When 2,2,4,4-tetramethylcyclobutane-1,3-diyl is a cis isomer, the dielectric loss tangent is even smaller. When 2,2,4,4-tetramethylcyclobutane-1,3-diyl is a mixture of cis-trans isomers and the molar (weight) ratio of the cis isomer is higher than that of the trans isomer, the dielectric loss tangent may be smaller than when only the cis isomer is used.

[0040] <Binding group Z: Z １ , Z ２ , and Z ３ > Bonding group Z of compound (1) １ , 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 The - may be replaced by -O-. １ , Z ２ , and Z ３ Preferred examples of are a single bond, —(CH ２ ) ａ -, -O(CH ２ ) ｂ -, -(CH ２ ) ｂ O-, -O(CH ２ ) ｃ O-, where a is an integer from 1 to 20, b is an integer from 1 to 19, and c is an integer from 1 to 18.

[0041] The bonding group Z is a single bond, -(CH ２ ) ａ -, -(CH ２ ) ｂ O-, -O(CH ２ ) ｂ -, -O(CH２ ) ｃ When the bonding group Z is -(CH ２ ) ａ -, -(CH ２ ) ｂ O-, -O(CH ２ ) ｂ -, or -O(CH ２ ) ｃ When the formula is O-, a is an integer of about 2 to 12, b is an integer of about 1 to 11, and c is an integer of about 1 to 10, the melting point is lowered, the solubility in solvents is high, and the volatility is low.

[0042] When compound (1) has two rings, the viscosity is low, and when compound (1) has three or more rings, the clearing point is high.

[0043] As described above, a compound having desired physical properties can be obtained by appropriately selecting the types of terminal group P, ring structure A, and bonding group Z, the number of rings, etc. Preferred examples of compound (1) include formulas (1-1) to (1-6).

[0044] In formulas (1-1) to (1-6), Z １ , Z ２ , and Z ３ are independently a single bond, -(CH ２ ) ａ -, -O(CH ２ ) ｂ -, -(CH ２ ) ｂ O-, -O(CH ２ ) ｃ O—, wherein a is an integer from 1 to 20, b is an integer from 1 to 19, and c is an integer from 1 to 18; ２ may be the same or different, X is fluorine or methyl, n is an integer of 0 to 4, and when there are a plurality of X's in the formula, they may be the same or different, including when n is 2 or more, P １ and P ２ are independently a polymerizable group represented by formula (PG-1), (PG-5), (PG-6), (PG-7), (PG-8), or (PG-9), In formulas (PG-1) and (PG-5), R ｂ represents hydrogen, halogen, -CF ３ or alkyl having 1 to 5 carbon atoms, q is 0 or 1, and in the formula R ｂ When there are a plurality of, they may be the same or different.

[0045] [Method for Synthesizing Compound (1)] Compound (1) can be synthesized by combining known methods in organic synthetic chemistry. Methods for introducing desired terminal groups, ring structures, and bonding groups into starting materials are described in, for example, 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).

[0046] The method for introducing the linking group Z is explained in the following schemes 1 to 5. 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), (1C), (1E), and (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).

[0047] (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 ２ Compound (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.

[0048]

[0049] (Scheme 2) Compounds where Z is -CH=CH- As shown below, a phosphorus ylide generated by reacting a phosphonium salt (S5) synthesized by a known method with a base such as potassium t-butoxide is reacted with an aldehyde (S4) to give MSG. １ and MSG ２ Compound (1B) can be synthesized in which —CH═CH— is introduced between the two. Depending on the reaction conditions and the substrate, a cis isomer may be produced, and the cis isomer can be isomerized to a trans isomer by a known method, if necessary.

[0050]

[0051] (Scheme 3) 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 Compound (1C) having - can be synthesized.

[0052]

[0053] (Scheme 4) Z is -(CH ２ ) ４As shown below, a compound of —(CH) was prepared by the method of Scheme 2 using phosphonium salt (S7) instead of phosphonium salt (S5). ２ ) ２ A compound having —CH═CH— is synthesized and catalytically hydrogenated in the same manner as in Scheme 3 to give MSG. １ and MSG ２ Between - (CH ２ ) ４ Compound (1E) into which - is introduced can be synthesized.

[0054]

[0055] (Scheme 5) 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 -OCH ２ - (or -CH ２ Compound (1F) having a substituted aryl group (O-) can be synthesized.

[0056]

[0057] [Polymer (1)] The compound (1) used in the present invention has a polymerizable group (terminal group P), and therefore can be easily polymerized. The polymer (1) in the present invention is at least one type of polymer obtained by polymerizing the compound (1). Specifically, the polymer (1) in the present invention is a homopolymer obtained by polymerizing one type of compound (1), a copolymer obtained by polymerizing two or more types of compound (1), or a copolymer obtained by polymerizing one or more types of compound (1) with one or more types of polymerizable compounds other than 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 compound (1). This oligomer refers to a low polymer having a low number (degree of polymerization) of constitutional units of compound (1) that constitute the polymer (1). Oligomers may also be called dimers, trimers, tetramers, etc., depending on the number of constitutional units.

[0058] [Composition (1)] The composition (1) of the present invention contains at least one compound (1) and is composed of two or more compounds. 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 compound other than the compound (1). The components other than the compound (1) are not particularly limited, but include, for example, polymer (1), polymerizable compounds other than the compound (1) (hereinafter also referred to as "other polymerizable compounds"), non-polymerizable liquid crystal compounds, optically active compounds, polymerization initiators, curing agents, solvents, inorganic fillers, and fibrous reinforcing agents. Preferred compositions (1) include compositions composed of at least one compound (1) and the polymer (1), compositions composed of at least one compound (1) and other polymerizable compounds, and compositions composed of at least one compound (1), the polymer (1), and other polymerizable compounds.

[0059] <Other Polymerizable Compounds> Composition (1) may contain a polymerizable compound (other polymerizable compound) other than compound (1). The polymerizable compound other than compound (1) is composed of at least one of the following polymerizable non-liquid crystal compounds other than compound (1) (hereinafter also referred to as "other polymerizable non-liquid crystal compounds") and at least one polymerizable liquid crystal compound. This polymerizable non-liquid crystal compound is classified as a polymerizable compound that is not a liquid crystal compound.

[0060] <Other Polymerizable Non-Liquid Crystalline Compounds> Composition (1) may contain other polymerizable non-liquid crystal compounds as constituent elements. Such 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, i.e., polymerizable compounds that are not liquid crystal compounds. Examples of polymerizable non-liquid crystal compounds include vinyl derivatives, styrene derivatives, (meth)acrylic acid derivatives, sorbic acid derivatives, fumaric acid derivatives, and itaconic acid derivatives. Preferred examples of these derivatives are shown below.

[0061] 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.

[0062] Preferred styrene derivatives include, for example, styrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, o-chloromethylstyrene, m-chloromethylstyrene, p-chloromethylstyrene, and α-methylstyrene.

[0063] 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, trisacryloyloxyethyl phosphate, bisphenol A EO adduct diacrylate, bisphenol A glycidyl diacrylate (trade name: "Biscoat 700" manufactured by Osaka Organic Chemical Industry Co., Ltd.), polyethylene glycol diacrylate dimethyl itaconate, and the like.

[0064] 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.

[0065] Preferred fumaric acid derivatives include, for example, dimethyl fumarate, diethyl fumarate, diisopropyl fumarate, dibutyl fumarate, dicyclopentyl fumarate, and dicyclohexyl fumarate.

[0066] Preferred itaconic acid derivatives include, for example, diethyl itaconate, dibutyl itaconate, diisopropyl itaconate, etc. In addition to these, many other polymerizable compounds such as butadiene, isoprene, maleimide, etc. can also be used.

[0067]

[0043] <Polymerizable Liquid Crystal Compound> Composition (1) may contain a polymerizable liquid crystal compound. From the viewpoints of the development of a liquid crystal phase in the polymerizable liquid crystal composition and the compatibility with compound (1) and a solvent, a compound represented by formula (M1), (M2), or (M3) is preferred as the polymerizable liquid crystal compound. In formulae (M1), (M2), and (M3), A Ｍ are independently any divalent group selected from 1,4-phenylene, 1,4-cyclohexylene, 1,4-cyclohexenylene, pyridine-2,5-diyl, 1,3-dioxane-2,5-diyl, naphthalene-2,6-diyl, and fluorene-2,7-diyl, in which at least one hydrogen may be replaced by fluorine, chlorine, cyano, hydroxy, formyl, trifluoroacetyl, difluoromethyl, trifluoromethyl, alkyl having 1 to 5 carbon atoms, alkoxy having 1 to 5 carbon atoms, alkoxycarbonyl having 1 to 5 carbon atoms, or alkanoyl having 1 to 5 carbon atoms; Z Ｍ are independently a single bond, —OCH ２ -, -CH ２ O-, -COO-, -OCO-, -COS-, -SCO-, -OCOO-, -CONH-, -NHCO-, -CF ２ O-, -OCF ２ -, -CH ２ CH ２ -, -CF ２ CF ２ -, -CH=CHCOO-, -OCOCH=CH-, -CH ２ CH ２ COO-,-OCOCH ２ CH ２ --COOCH ２ CH ２ -, -CH ２ CH ２ OCO-, -CH=CH-, -N=CH-, -CH=N-, -N=C(CH３ ) -, -C(CH ３ )=N-, -N=N-, -C≡C-, -CH=N-N=CH-, or -C(CH ３ )=NN=C(CH ３ )- and X Ｍ is hydrogen, fluorine, chlorine, trifluoromethyl, trifluoromethoxy, cyano, alkyl having 1 to 20 carbon atoms, alkenyl having 1 to 20 carbon atoms, alkoxy having 1 to 20 carbon atoms, or alkoxycarbonyl having 1 to 20 carbon atoms; Y Ｍ is independently a single bond, —O—, —COO—, —OCO—, or —OCOO—, and Q Ｍ represents a single bond, —O—, —COO—, or —OCO—; q represents an integer of 1 to 6; c and d are independently integers of 0 to 3 and satisfy the relationship 1≦c+d≦6; a represents an integer of 0 to 20; R Ｍ is hydrogen or methyl.

[0068] <Non-Polymerizable Liquid Crystalline Compound> Composition (1) may contain a liquid crystal compound without a polymerizable group as a constituent element. Examples of such non-polymerizable liquid crystal compounds are described in LiqCryst (LCI Publisher GmbH, Hamburg, Germany), a database of liquid crystal compounds. Polymerization of composition (1) containing a non-polymerizable liquid crystal compound can produce composite materials containing a polymer of compound (1) and a liquid crystal compound. In such composite materials, the non-polymerizable liquid crystal compound is present in a polymer network, such as a polymer-dispersed liquid crystal.

[0069] <Polymerization initiator> In the composition (1), when the polymerizable groups of the compound (1) and other polymerizable compounds are radically reactive, a polymerization initiator may be used as a constituent element. The polymerization initiator may be, for example, a photoradical polymerization initiator, a photocationic polymerization initiator, or a thermal radical polymerization initiator, depending on the polymerization method of the composition (1).

[0070] The photoradical polymerization initiator is not particularly limited, and known initiators can be used, such as 4-methoxyphenyl-2,4-bis(trichloromethyl)triazine, 2-(4-butoxystyryl)-5-trichloromethyl-1,3,4-oxadiazole, 9-phenylacridine, 9,10-benzphenazine, benzophenone / Michler's ketone mixture, hexaarylbiimidazole / mercaptobenzimidazole mixture, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, benzyl dimethyl ketal, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,4-diethylxanthone / methyl p-dimethylaminobenzoate mixture, and benzophenone / methyltriethanolamine mixture. Examples of commercially available products include "Darocur Series 1173, 4265" and "Irgacure Series 184, 369, 500, 651, 784, 819, 907, 1300, 1700, 1800, 1850, 2959" manufactured by Ciba Specialty Co., Ltd.

[0071] The photocationic polymerization initiator is not particularly limited, and known ones can be used, and examples thereof include commercially available products such as "Sylacure UVI-6990, 6974" manufactured by UCC Corporation, "ADEKA Optomer SP-150, 152, 170, 172" manufactured by ADEKA Corporation, "Photoinitiator 2074" manufactured by Rhodia Corporation, "Irgacure 250" manufactured by Chiba Specialty Co., Ltd., and "DTS-102" manufactured by Midori Chemical Co., Ltd.

[0072] Preferred examples of the thermal radical polymerization initiator include benzoyl peroxide, diisopropyl peroxydicarbonate, t-butylperoxy-2-ethylhexanoate, t-butyl peroxypivalate, di-t-butyl peroxide (DTBPO), t-butyl peroxydiisobutyrate, lauroyl peroxide, dimethyl 2,2′-azobisisobutyrate (MAIB), azobisisobutyronitrile (AIBN), and azobiscyclohexanecarbonitrile (ACN).

[0073] Preferred initiators for anionic polymerization, coordination polymerization and living polymerization include, for example, alkali metal alkyl compounds such as n-C4H9Li and t-C4H9Li-R3Al, aluminum compounds, transition metal compounds and the like.

[0074] <Curing Agent> When the composition (1) contains a compound having a cyclic ether group as a constituent element, it may contain a curing agent as a constituent element. Preferred examples of the curing agent are shown below.

[0075] 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, 1,2 -diaminocyclohexane, 3,9-dipropanamine-2,4,8,10-tetraoxaspiro[5,5]undecane, 4,4'-diaminodiphenylmethane, 4,4'-diamino-1,2-diphenylethane, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylsulfone, polyoxypropylenediamine, polyoxypropylenetriamine, polycyclohexylpolyamine, and N-aminoethylpiperazine.

[0076] 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 bisanhydrotrimellitate, glycerin bis(anhydrotrimellitate) monoacetate, dodecenyl succinic anhydride, and chlorendic anhydride.

[0077] 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.

[0078] The active ester curing agent is not particularly limited, and known active ester curing agents can be used. Examples thereof include commercially available products such as "HPC-8000H-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.

[0079] 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.

[0080] <Inorganic Filler and Fibrous Reinforcing Agent> An inorganic filler or fibrous reinforcing agent can be added to the composition (1) to improve thermal conductivity, mechanical strength, adjust viscosity, etc. In this specification, the inorganic filler may be referred to as "inorganic filler." 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, and hollow silica is more preferred. Fibrous reinforcing agents can be used as fibrous or whisker-like inorganic fillers to increase the strength of substrates and resin parts. Inorganic fibers such as glass cloth, low-dielectric glass cloth, carbon fiber, and carbon nanotubes, and inorganic whiskers such as silicate whiskers, alumina whiskers, magnesium oxide whiskers, zinc oxide whiskers, and aluminum nitride whiskers are preferred, with low-dielectric glass cloth, aluminum oxide whiskers, and aluminum nitride whiskers being more preferred. To increase mechanical strength, a larger amount of inorganic filler is preferable, but if there is too much, the resin may not be able to fill the gaps between the inorganic fillers. Also, if there is too much resin, the effect of increasing mechanical strength may not be achieved. Furthermore, increasing the amount of inorganic 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 reinforcing agents. Examples of organic fibers with high mechanical strength include polyamide fibers, aramid fibers, polyparaphenylene benzobisoxazole fibers, and liquid crystalline polyester fibers. Organic fibers are lighter than inorganic fibers and are therefore preferred for substrates of portable devices.Examples of inorganic 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. The composition (1) of the present invention has high transparency and low dielectric constant. When used as a low refractive optical material, the refractive index can be adjusted by adding powders such as hollow silica, spherical silica, titanium oxide, and zirconium oxide.

[0081] The shape of the inorganic filler may be spherical, amorphous, fibrous, whisker-like, cylindrical, plate-like, etc. The type, shape, size, and amount of the inorganic filler may be appropriately selected depending on the purpose. When the resulting polymer molded article requires insulation, the inorganic filler may be conductive as long as the desired insulation properties, mechanical strength, dielectric constant, and dielectric loss are maintained.

[0082] The average particle size of the spherical or irregularly shaped inorganic filler is preferably 0.1 to 200 μm, more preferably 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 inorganic fillers or fibrous reinforcing agents, longer fiber lengths improve tensile strength, but may make kneading or dispersion difficult. Therefore, selection is preferred depending on the application. When dispersed, the average particle size of the fibrous inorganic filler or fibrous reinforcing agent is preferably 0.01 to 200 μm, more preferably 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 allows for increased mechanical strength. The amount of inorganic filler or fibrous reinforcing agent is preferably 20 to 95 wt % of the inorganic filler or fibrous reinforcing agent in the cured polymer molded body, more preferably 50 to 95 wt %. A content of 20 wt % or more is preferable because the thermal conductivity becomes high, and a content of 95 wt % or less is preferable because the polymer molding does not become brittle.

[0083] As the inorganic filler or fibrous reinforcing agent, 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 agent has been removed may be used. Alternatively, untreated inorganic fillers may be used after being treated with a silane coupling agent, affinity agent, surface tension adjuster, anti-settling agent, anti-aggregation agent, etc.

[0084] <Solvent> Composition (1) may contain a solvent. Curing of composition (1) may be carried out in a solvent or without a solvent. Composition (1) containing a solvent may be applied to a substrate by, for example, spin coating, and then the solvent may be removed before photocuring. After photocuring, the composition may be heated to an appropriate temperature and post-treated by thermal curing.

[0085] Preferred 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 solvents may be used alone or in combination of two or more. It is not particularly meaningful to limit the proportion of solvent used during curing; the proportion may be determined for each individual case, taking into consideration factors such as curing efficiency, solvent cost, and energy cost.

[0086] Composition (1) of the present invention preferably contains 70 wt% or less of a solvent based on the 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 a solvent, or that exhibits high fluidity when melted. Using a composition containing 70 wt% or less of a solvent based on the total weight, or a solvent-free composition, increases the concentration of the cured product, thereby enabling 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 a solvent based on the 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. Examples of solvents that can be used here include acetone, methyl ethyl ketone, toluene, xylene, methyl isobutyl ketone, ethyl acetate, ethylene glycol monomethyl ether, N,N-dimethylformamide, methanol, and ethanol, which are relatively low in toxicity from the perspective of environmental impact. The composition (1) of the present invention can form a resin having high heat resistance and a high degree of low dielectric constant in a non-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.

[0087] <Other Additives> Because compound (1) and composition (1) have high polymerizability, a stabilizer may be added 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 tangent (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 groups of compound (1) having polymerizable groups at both ends used in the present invention to form a three-dimensional crosslink.

[0088] 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 (PPE 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 (PPE 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.

[0089] [Low-Dielectric-Constant Resin] Another embodiment of the present invention is a low-dielectric-constant resin, which is a cured product of the above-mentioned composition (1), and is used for sheet-shaped, film-shaped, plate-shaped, fibrous, and three-dimensionally shaped parts (insulating parts of connectors), etc., and can also be used as a coating agent, adhesive, or filler as is. Since the low-dielectric-constant resin is a cured product of the above-mentioned composition (1), it has a low dielectric constant, and since it uses a polymer (1) obtained by polymerizing a composition (1) containing a polymerizable non-liquid crystal compound as the polymer, it is also excellent in transparency, heat resistance, rigidity, elasticity, molding flowability, chemical resistance, dimensional stability, etc.

[0090] [Low-Dielectric-Constant Resin Insulating Film, Low-Dielectric-Constant Resin Film, and Low-Dielectric-Constant Resin Sheet] The polymer molded article of the present invention is a molded article of a low-dielectric-constant resin, which is a cured product of the low-dielectric-constant resin-forming composition comprising the composition (1). It can be used as a thin-film low-dielectric-constant resin insulating film, as well as in sheet-, film-, thin-film, plate-, fibrous, or three-dimensionally shaped parts (insulating portions of connectors), or as a coating agent, adhesive, or filler. When used in thin-film, film-, sheet-, plate-, fibrous, or three-dimensionally shaped molded articles, 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 a substrate or a mold. Alternatively, composition (1) containing a solvent can be applied to an orientation-treated substrate and then the solvent removed. 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.

[0091] [Low-Dielectric Resin Parts and Electronic Devices] The low-dielectric resin-forming composition of the present invention can be used to form low-dielectric resin parts such as low-dielectric resin insulating films, low-dielectric resin films, and low-dielectric resin sheets. It is also useful for various electronic applications such as low-dielectric resin substrates, low-dielectric resin coatings, low-dielectric resin adhesives, and low-dielectric resin molded products. Furthermore, the low-dielectric resin-forming composition of the present invention is highly transparent to visible light and THz waves and exhibits a low optical refractive index, making it useful for applications such as window materials, covers, protective layers, sealants, and fillers that transmit radio waves for 5G / 6G communications and millimeter-wave radar, for which conventional glass, polyimide, and other resins have low transmittance. While most resins in this field are thermoplastic resins such as liquid crystal polymers, polyphenylene ethers, fluororesins, polypropylene, and polyethylene, the low-dielectric resin-forming composition of the present invention can be converted into a photocurable or thermosetting resin by selecting a polymerization initiator and curing agent, thereby exhibiting excellent microprocessability and low-temperature processability, making it useful for, for example, optical modulators and optical connection paths formed on a micron scale.

[0092] <Production Method> Hereinafter, a method for producing a low dielectric constant resin-forming composition, and a method for producing a low dielectric constant, highly heat-resistant substrate and a low dielectric constant, highly heat-resistant insulating film from the composition will be specifically described.

[0093] The low dielectric constant resin-forming composition of the present invention can be used as a liquid resin raw material as is, or can be dissolved in a solvent and used as a solution. The low dielectric constant resin-forming composition is prepared by adding compound (1), a polymerizable non-liquid crystal compound, a 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 a rotation speed of 2000 rpm for 10 minutes, and then degassed at a rotation speed of 2200 rpm for 10 minutes. In addition to the rotation / revolution mixer, a stirring motor, a mortar and pestle, a three-roll mill, a ball mill, a rotation / revolution mill, a planetary mill, a bead mill, a jet mill, or the like can be used to disperse the mixture.

[0094] As the application method, a wet coating method is preferably used to uniformly coat the low dielectric constant resin-forming composition. Among wet coating methods, when producing a small amount of low dielectric constant resin parts, spin coating is preferred because it allows for simple and uniform film formation. 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, etc. are preferred. The wet coating method can be appropriately selected from these methods depending on the required film thickness, viscosity, curing conditions, etc.

[0095] When producing a sheet, a casting method is used in which the low dielectric constant resin-forming composition is coated on a release-treated substrate using the above-mentioned method or the like and then peeled off, and when producing a structure, a mold is used as needed, and resin molding methods such as press molding, injection 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.

[0096] [Examples] The present invention will be explained in more detail with reference to examples (including preparation examples of compounds, compositions, polymers, low dielectric constant resins, etc.), but the present invention is not limited to these examples.

[0097] [Synthesis of Compound (1)] Compound (1) was synthesized according to the procedures shown in Examples 1 to 6. Unless otherwise specified, the reactions were carried out under a nitrogen atmosphere. The synthesized compounds were identified by methods such as NMR analysis. The device characteristics of compound (1), composition (1), polymer (1), low dielectric constant resin, etc. were measured by the following methods.

[0098] <NMR Analysis> Measurement was performed using JNM-ECZR manufactured by JEOL Ltd. １ For H-NMR measurements, the sample was ３The 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 number of accumulations was 32. In the explanation of nuclear magnetic resonance spectra, s means singlet, d means doublet, t means triplet, q means quartet, quin means quintet, sex means sextet, m means multiplet, and br means broad.

[0099] <Gas Chromatography Analysis> A GC-2014 gas chromatograph manufactured by Shimadzu Corporation was used for the measurements. The column used was a DB-1 capillary column (30 m or 15 m long, 0.25 mm inner diameter, 0.25 μm film thickness) 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.

[0100] <HPLC Analysis> A Prominence (LC-20AD; SPD-20A) manufactured by Shimadzu Corporation was used for the measurement. 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 acetonitrile and pure water was used as the eluent. A UV detector, RI detector, CORONA detector, or the like was used as the detector. When a UV detector was used, the detection wavelength was 254 nm. The sample was dissolved in 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.

[0101] <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.

[0102] <Measurement Sample> When measuring the phase structure and transition temperatures (clearing point, melting point, polymerization initiation temperature, etc.), the compound itself was used as the sample. (1) Phase Structure A sample was placed on the hot plate of a melting point measurement device equipped with a polarizing microscope (FP-52 hot stage manufactured by Mettler Toledo K.K.). The sample was heated at a rate of 3°C / min, and the phase state and its changes were observed with the polarizing microscope to identify the type of phase.

[0103] (2) Transition Temperature (°C) Measurements were performed using a high-sensitivity differential scanning calorimeter, X-DSC7000, manufactured by Hitachi High-Tech Science Corporation (formerly SSI 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. The temperature at which a compound transitions from a solid 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 liquid crystal phase to a liquid is sometimes abbreviated as the "clearing point."

[0104] Crystals are represented as C. When the types of crystals can be distinguished, each is represented as C. １ , C ２ The smectic phase is represented as S, and the nematic phase as N. When the smectic phase can be distinguished as smectic A, smectic B, smectic C, or smectic F, they are represented as S, N, and N, respectively. Ａ , S Ｂ , S Ｃ , or S Ｆ The liquid (isotropic) phase is represented as I. The transition temperatures are represented as, for example, "C 50.0 N 100.0 I", which 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.

[0105] Example 1 2,2,4,4-tetramethylcyclobutane-1,3-diol (S01-a) with a cis:trans ratio of 98:2 was used. This raw material can be obtained, for example, by the method described in JP-A-2021-155412.

[0106] (Step 1) Under a nitrogen atmosphere, methacryloyl chloride (16.7 g, 159.5 mmol) was added to a solution of 2,2,4,4-tetramethylcyclobutane-1,3-diol (S01-a) (10.0 g, 69.3 mmol) and triethylamine (21.1 g, 208.0 mmol) in tetrahydrofuran (200 mL). The mixture was stirred overnight while returning to room temperature. The reaction mixture was poured into pure water and extracted with toluene. The mixture was washed twice with saturated aqueous sodium bicarbonate and once with saturated brine, and the organic layer was concentrated under reduced pressure at 40°C. The resulting residue was purified by silica gel column chromatography (solvent: toluene / ethyl acetate = 20 / 1 (volume ratio)) to isolate compound (S01) (6.5 g, 69.3 mmol). The transition temperature of this compound (S01) was C 32.5 I (°C). The polymerization initiation temperature was 158°C. The compound (S01) maintained the cis to trans ratio of the raw material, cis:trans = 98:2. １ The H-NMR signals were as follows: δ (ppm; CDCl ３ ): 6.15-6.14 (dq, 2H), 5.59-5.58 (dq, 2H), 4.38 (s, 2H), 1.97-1.96 (dd, 6H), 1.31 (s, 6H), 1.04 (s, 6H).

[0107] Example 2 2,2,4,4-tetramethylcyclobutane-1,3-diol (S02-a) manufactured by JNC Corporation with a cis:trans ratio of 50:50 was used.

[0108] (First step) Under a nitrogen atmosphere, methacryloyl chloride (16.7 g, 159.5 mmol) was added to a solution of 2,2,4,4-tetramethylcyclobutane-1,3-diol (S02-a) (10.0 g, 69.3 mmol) and triethylamine (21.1 g, 208.0 mmol) in tetrahydrofuran (200 mL), and the mixture was stirred overnight while returning to room temperature. The reaction solution was poured into pure water and extracted with toluene. After washing twice with saturated aqueous sodium bicarbonate and once with saturated saline, the organic layer was concentrated under reduced pressure at 40°C. The resulting residue was subjected to silica gel column chromatography (solvent: toluene) to isolate the trans isomer, yielding compound (S02) (2.9 g, 10.2 mmol). The transition point of this compound (S02) was C 59.9 I (°C). The polymerization initiation temperature was 155°C. １ The H-NMR signals were as follows: δ (ppm; CDCl ３ ): 6.16-6.15 (dq, 2H), 5.59-5.58 (dq, 2H), 4.52 (s, 2H), 1.97-1.97 (dd, 6H), 1.16 (s, 12H).

[0109] [Example 3]

[0110] (Step 1) Under a nitrogen atmosphere, 40 wt% aqueous sodium hydroxide solution (8.7 g, 86.7 mmol) was added in small portions to a solution of 2,2,4,4-tetramethylcyclobutane-1,3-diol (S01-a) (25.0 g, 173.4 mmol) and tert-butyl acrylate (66.7 g, 520.1 mmol) in dimethyl sulfoxide (125 mL), and the mixture was stirred overnight at room temperature. The reaction solution was poured into purified water and extracted with toluene (600 mL). After washing twice with purified water and once with saturated brine, the organic layer was concentrated under reduced pressure at 40°C. The resulting residue was purified by silica gel column chromatography (solvent: heptane / ethyl acetate = 12 / 1 (volume ratio)) to isolate compound (S03-a) (65.0 g, 162.2 mmol).

[0111] (Step 2) Under a nitrogen atmosphere, lithium aluminum hydride (4.5 g, 118.0 mmol) was added portionwise to tetrahydrofuran (115 mL) at temperatures below 0°C and stirred. A solution of compound (S03-a) (31.5 g, 78.6 mmol) in tetrahydrofuran (200 mL) was added dropwise, and the mixture was stirred overnight while returning to room temperature. The reaction mixture was ice-cooled, and purified water and 15 wt% aqueous sodium hydroxide solution were added dropwise and stirred for 30 minutes. Insoluble matter was removed by filtration, and the organic layer of the filtrate was concentrated under reduced pressure at 40°C. Ethyl acetate (800 mL) was added, and the organic layer was washed once each with 1N hydrochloric acid, purified water, and saturated brine. The organic layer was then concentrated under reduced pressure at 40°C. The resulting residue was purified by silica gel column chromatography (solvent: toluene / ethyl acetate = 1 / 2 (volume ratio)) to isolate compound (S03-b) (16.1 g, 55.3 mmol).

[0112] (Step 3) Under a nitrogen atmosphere, methacrylic acid (10.4 g, 120.9 mmol) was added to a dichloromethane (160 mL) solution of compound (S03-b) (16.0 g, 54.9 mmol), and the mixture was stirred under ice cooling. At 5°C or below, 4-dimethylaminopyridine (1.3 g, 11.0 mmol) and N,N'-dicyclohexylcarbodiimide (26.1 g, 126.4 mmol) were added in small portions, and the mixture was stirred overnight while returning to room temperature. Insoluble matter was filtered off, and the organic layer of the filtrate was washed three times with saturated brine and then concentrated under reduced pressure at 40°C. The resulting residue was purified by silica gel column chromatography (solvent: heptane / ethyl acetate = 10 / 1 (volume ratio)) to isolate compound (S03) (14.2 g, 35.8 mmol). The transition temperature of this compound (S03) was C 20.5 I (°C). The polymerization initiation temperature was 119°C. The compound (S03) maintained the cis to trans ratio of the raw material, cis:trans = 98:2. １ The H-NMR signals were as follows: δ (ppm; CDCl ３ ): 6.10 (dq, 2H), 5.56-5.55 (dq, 2H), 4.27-4.24 (t, 4H), 3.45-3.42 (t, 4H), 2.92 (s, 2H), 1.96-1.90 (m, 10H), 1.15 (s, 6H), 0.99 (s, 6H).

[0113] [Example 4]

[0114] (Step 1) Under a nitrogen atmosphere, sodium hydride (55 wt%, 18.2 g, 416.1 mmol) was added portionwise to a solution of 2,2,4,4-tetramethylcyclobutane-1,3-diol (S01-a) (20.0 g, 138.7 mmol) in N,N-dimethylformamide (160 mL) and stirred at room temperature. 6-Bromo-1-hexene (67.8 g, 416.1 mmol) was added dropwise at temperatures below 40°C, and the mixture was stirred overnight while returning to room temperature. The reaction solution was poured into ice water and extracted with toluene (800 mL). After washing twice with purified water and once with saturated brine, the organic layer was concentrated under reduced pressure at 40°C. The resulting residue was purified by silica gel column chromatography (solvent: heptane / ethyl acetate = 12 / 1 (volume ratio)) to isolate compound (S04) (22.9 g, 74.2 mmol). The compound (S04) maintained the cis to trans ratio of the raw material, cis:trans = 98:2. １ The H-NMR signals were as follows: δ (ppm; CDCl ３ ): 5.85-5.77 (ddt, 2H), 5.03-4.98 (ddt, 2H), 4.96-4.93 (ddt, 2H), 3.35-3.32 (t, 4H), 2.91 (s, 2H), 2.09-2.05 (m, 4H), 1.60-1.42 (m, 8H), 1.15 (s, 6H), 1.00 (s, 6H).

[0115] [Example 5]

[0116] (Step 1) Under a nitrogen atmosphere and ice cooling, metachloroperbenzoic acid (mCPBA) (75 wt%) (31.3 g, 136.1 mmol) was suspended in dichloromethane (200 mL), and compound (S04) (20.0 g, 64.8 mmol) obtained in Example 4 was added portionwise. The mixture was stirred overnight while returning to room temperature. After the reaction was complete, insoluble matter was filtered off, and 10 wt% aqueous sodium thiosulfate solution was added to the filtrate and stirred at room temperature. The organic layer was washed once with 10 wt% aqueous sodium thiosulfate solution, twice with 1 wt% aqueous sodium hydroxide solution, once 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: heptane / ethyl acetate = 4 / 1 (volume ratio)) to isolate compound (S05) (18.6 g, 54.7 mmol). This compound (S05) was a liquid at room temperature, and no phase transition or polymerization was observed using the DSC (high-sensitivity differential scanning calorimeter, X-DSC7000). The compound (S05) maintained the cis:trans ratio of 98:2 of the raw material. １ The H-NMR signals were as follows: δ (ppm; CDCl ３ ): 3.36-3.33 (t, 4H), 2.94-2.90 (m, 4H), 2.76-2.75 (dd, 2H), 2.48-2.47 (dd, 2H), 1.64-1.50 (m, 12H), 1.15 (s, 6H), 1.00 (s, 6H).

[0117] [Example 6]

[0118] Under a nitrogen atmosphere, sodium hydride (55 wt%, 3.6 g, 83.2 mmol) was added portionwise to a solution of 2,2,4,4-tetramethylcyclobutane-1,3-diol (S01-a) (5.0 g, 34.7 mmol) in N,N-dimethylformamide (100 mL) and stirred at room temperature. 4-Chloromethylstyrene (14.1 g, 83.2 mmol) was added in an ice bath, and the mixture was stirred overnight while returning to room temperature. The reaction solution was poured into ice water and extracted with toluene (600 mL). After washing twice with pure water and once with saturated brine, the organic layer was concentrated under reduced pressure at 40 °C. The resulting residue was isolated using silica gel column chromatography (solvent: heptane / ethyl acetate = 10 / 1 (volume ratio)) and recrystallized from ethanol to obtain compound (S06) (8.2 g, 21.8 mmol). The transition point of this compound (S06) was C 61.8 I (°C). The polymerization initiation temperature was 90°C. The compound (S06) maintained the cis to trans ratio of the raw material, cis:trans = 98:2. １ The H-NMR signals were as follows: δ (ppm; CDCl ３ ): 7.39-7.29 (m, 8H), 6.74-6.68 (dd, 2H), 5.76-5.72 (dd, 2H), 5.24-5.22 (dd, 2H), 4.46 (s, 4H), 3.08 (s, 2H), 1.16 (s, 6H), 1.14 (s, 6H).

[0119] [Physical Property Evaluation of Dielectric Properties (Dielectric Constant and Dielectric Loss Tangent) and Transmittance] [Example 7] <Preparation of Sample for Measuring Dielectric Properties (Dielectric Constant and Dielectric Loss Tangent) and Transmittance> 2.0 g of compound (S01), a cyclobutane polymerizable compound, as compound (1) and 0.02 g of dilauroyl peroxide (FUJIFILM Wako Pure Chemical Industries, Ltd.) as a polymerization initiator were placed in an aluminum cup with a handle and a bottom diameter of 45 mm, and stirred with a polypropylene stirring rod until the polymerization initiator dissolved. This solution was placed in an aluminum container into which nitrogen gas could be flowed and placed in a hot air oven. While flowing nitrogen gas at a rate of 50 mL per minute, the oven temperature was increased to 200 ° C. and maintained at 200 ° C. for 1 hour to cure the polymerizable compound (S01). After the oven cooled to room temperature, the aluminum cup containing the cured product was removed, and a disc-shaped sample with a diameter of 45 mm and a thickness of 1.0 mm was obtained from the bottom of the aluminum cup. This sample was used as a sample for terahertz spectroscopy, as described below. A mixed solution of a polymerization initiator and a polymerizable compound (S01) was prepared in the same manner as when preparing the disk-shaped sample. The mixed solution was applied to the glossy surface of thick aluminum foil using an applicator so that a flat area of ​​approximately 50 μm thick and 70 mm square or larger was obtained after curing, and the sample was cured under the same conditions. The aluminum foil was carefully peeled off to prevent the sample from cracking, and the sample was used for measuring dielectric properties (relative permittivity and dielectric loss tangent) using the cavity resonance method.

[0120] <Method for Evaluating Dielectric Properties (Relative Permittivity and Dielectric Loss Tangent) and Transmittance> Spectroscopic measurements were performed using a TAS7500SP terahertz spectroscopy system manufactured by Advantest Corporation from 0.1 THz to 4 THz, and the relative permittivity, dielectric loss tangent (tan δ), and transmittance were calculated using the calculation function included in the company's measurement software. The dielectric properties at 10 GHz were measured using a cavity resonator (TE mode 10 GHz) manufactured by AET, INC. connected to a vector network analyzer (MS46522B-043 manufactured by Anritsu Corporation) to measure the resonant frequency shift and attenuation of the dielectric property measurement sample, 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 in these measurements, the thickness of the prepared sample was measured at five points centered on the actual measurement area using a Mitutoyo Digimatic Micrometer, and the average value was used for calculations. To reduce the influence of the moisture content of the sample during measurement, the sample was left in a desiccator overnight, and on the day of measurement, the sample was left to stand for at least 60 minutes in a laboratory at a temperature of 20°C and a relative humidity of 48% RH before measurement began.

[0121] [Example 8] As the compound (1), 1.4 g and 0.6 g of compound (S01), a cyclobutane polymerizable compound, and compound (S02), a cyclobutane polymerizable compound, were weighed out, respectively, and samples with a diameter of 45 mm were prepared in the same manner as in Example 7, except that the dielectric properties and transmittance were measured using a terahertz spectrometer. The results are shown in Example 8.

[0122] [Example 9] 0.6 g and 1.4 g of compound (S01), a cyclobutane polymerizable compound, and compound (S02), another cyclobutane polymerizable compound, were weighed out as compound (1), respectively, and samples with a diameter of 45 mm were prepared in the same manner as in Example 7, and their dielectric properties and transmittance were measured using a terahertz spectrometer. The results are shown in Example 9.

[0123] Example 10 A sample was prepared and evaluated in the same manner as in Example 7, except that compound (S03), a cyclobutane polymerizable compound, was used as compound (1). The results are shown in Example 10.

[0124] Example 11 A sample was prepared and evaluated in the same manner as in Example 7, except that the compound (S06), which is a cyclobutane polymerizable compound, was used as the compound (1). The results are shown in Example 11.

[0125] Example 12 1.02 g of compound (S05), a cyclobutane-polymerizable compound, as compound (1) and 0.623 g of a commercially available amine-based curing agent, diamine 1 (Tokyo Chemical Industry Co., Ltd.: 4,4'-ethylenedianiline (Wako Special Grade)), were placed in a 30 mL glass screw bottle, and the diamine 1 was dissolved by heating to 50°C using a dry bath. The mixture was transferred to an aluminum cup with a handle and a 45 mm bottom diameter, the same as in Example 7, whose inner surface had been previously treated for release, using Daikin Industries, Ltd.'s Daifree GA-9700 (trade name) mold release agent. The mixture was then cured and evaluated in the same manner as in Example 7. Portions of the aluminum where the aluminum did not peel off were scraped off with a utility knife. However, because the rough surface of these portions scattered the laser light, measurements were made on smooth, transparent portions. The thickness of the measured portion was 800 μm. The results are shown as Example 12.

[0126] [Comparative Example 1] A compound (ref. 01) synthesized by the method described in WO 2022 / 092063 was used as the polymerizable compound, and a sample was prepared in the same manner as in Example 7, and the dielectric properties and transmittance were measured. The results are shown as Comparative Example 1. The compound used in WO 2022 / 092063 is also a compound in which both OH groups of 4,4'-bicyclohexanediol are trans in order to form a mesogenic structure, which was separated and purified from the isomer mixture that was the starting material.

[0127] Comparative Example 2 A sample was prepared in the same manner as in Example 12, except that 1.07 g of a commercially available biphenyl-type epoxy resin, YX4000H (manufactured by Mitsubishi Chemical Corporation, product name: JER (registered trademark) YX-4000H), was used as the polymerizable compound instead of compound (S05), which is a cyclobutane-polymerizable compound, and the resulting mixture was placed in a 30 mL glass screw bottle together with 0.626 g of a commercially available amine-based curing agent, Diamine 2 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.: 4,4'-methylenedianiline (Wako Special Grade)), and the diamine 2 was dissolved by heating to 115°C on a hot plate. The result is referred to as Comparative Example 2. The samples of Example 12 and Comparative Example 2 had lower transmittance than the other compounds, and under the same conditions as Example 7 (samples with a thickness of 1.0 mm), the variation in the measured values ​​was very large in the range of 2 THz to 7 THz, so measurements were limited to up to 2 THz (see Tables 4 and 5).

[0128] Table 1: Dielectric properties (0.5-3 THz) of compositions containing polymerizable compounds having methacryloyloxy as the polymerizable group

[0129] [Table 2] Dielectric properties (0.5 to 3 THz) of compositions containing polymerizable compounds having methacryloyloxy as the polymerizable group

[0130] [Table 3] Dielectric properties at 10 GHz of compositions containing polymerizable compounds having methacryloyloxy as the polymerizable group

[0131] Comparing Example 7 with Comparative Example 1, it is clear that the polymerizable compound having a cyclobutane ring in its skeleton used in the present invention (hereinafter sometimes referred to as a cyclobutane polymerizable compound) has a lower dielectric constant and a lower dielectric loss tangent at 10 GHz and 0.5 to 3 THz than a methacrylate having a rigid dicyclohexyl structure in its skeleton. Furthermore, comparing Examples 7 to 9, it is clear that the dielectric properties are further improved by incorporating a moderate amount of the less linear trans isomer than by using the more linear cis isomer alone. Within the range of this study, the best dielectric properties were obtained when the cis isomer was 68.6 wt % and the trans isomer was 31.4 wt %. Meanwhile, in the range below 1 THz, the more linear the cis isomer, the lower the dielectric loss tangent. However, at 3 THz, the less linear the trans isomer, the lower the dielectric loss tangent. Therefore, the optimal cis:trans ratio for low dielectric loss tangent varies depending on the frequency band used. Thus, when communication speed is important in the device being used, that is, when a small dielectric constant is important, a composition containing a moderate amount of cis isomers and trans isomers is suitable. When long communication distances and low loss, i.e., a small dielectric tangent, are important, a composition that is biased between cis and trans isomers depending on the frequency band being used is suitable, so it is preferable to optimize the cis:trans ratio depending on the form of use. International Publication No. 2022 / 092063 and JP 2023-47892 A use a highly linear dicyclohexyl structure as the backbone, and by arranging it into a stable structure through liquid crystallization or crystallization, molecular motion is suppressed when an electric field is applied. However, because the cyclobutane ring has a flexible molecular chain, there is little stabilization due to the arrangement, and it is thought that the dielectric properties are improved by increasing the number of voids where electrons are not resonating. Comparing Example 7 and Example 10, there is little difference in the dielectric properties of the cured product, but flexibility is improved, so the introduction of an alkyl chain is preferable for adjusting physical properties other than the dielectric properties. Furthermore, Table 3 shows that the dielectric properties of the cyclobutane polymerizable compound used in the present invention are superior to those of the comparative example using dicyclohexane even in the 10 GHz region, and that the compound is an excellent material with a low dielectric constant and a low dielectric loss tangent even in the GHz band used in 5 G.

[0132] Table 4: Dielectric properties (0.5-2 THz) of compositions containing cyclobutane polymerizable compounds with different polymerizable groups

[0133] Table 5: Dielectric properties (0.5-2 THz) of compositions containing cyclobutane polymerizable compounds with different polymerizable groups

[0134] Table 6: Dielectric properties at 10 GHz of compositions containing cyclobutane polymerizable compounds with different polymerizable groups

[0135] A comparison of Example 7 and Example 11 reveals that the compound (S01) in which the polymerizable group is methacryloyloxy has a lower dielectric constant. Furthermore, the compound (S06) in which the vinyl group of the polymerizable group is bonded to a benzene ring has a superior dielectric dissipation factor to the compound (S01). Meanwhile, with regard to the compound (S05) having an epoxy group, which is in high demand for adhesive applications, the dielectric constant and dielectric dissipation factor are both relatively large in comparisons with Examples 7, 11, and 12, likely due to the influence of the curing agent. However, compared with YX4000H of Comparative Example 2, which has a biphenyl skeleton similar to that of Comparative Example 1 as a mesogenic skeleton, Example 12 has significantly lower dielectric constants and dielectric dissipation factors. Therefore, the cyclobutane polymerizable compounds used in the present invention can be suitably used in applications requiring both low dielectric constant and adhesive properties.

[0136] When electromagnetic waves are used in communications in the terahertz range, they are less likely to penetrate materials than conventional electromagnetic waves, resulting in the problem of being blocked by window glass, for example. Therefore, the transmittances of the sample of Example 8, which has a low relative dielectric constant, the sample of Example 11, which has a low dielectric loss tangent, a commercially available Kapton film (manufactured by DuPont-Toray Co., Ltd., product name: Kapton 200H, thickness 50 μm), which is a polyimide, and a commercially available alkali-free glass (Gorilla® Glass, manufactured by Corning Japan Inc., thickness 0.55 mm) were measured and designated Comparative Examples 3 and 4, respectively. Because the thicknesses of the samples differed, the transmittances were calculated using thicknesses close to 500 μm according to the Beer-Lambert law and compared.

[0137] Table 7: Transmittance in the THz region after curing of the composition containing the polymerizable compound used in the present invention

[0138] As shown in Table 7, the cyclobutane polymerizable compound used in the present invention has a higher transmittance than polyimide, which is widely used in electronic applications, and alkali-free glass, even in the 0.5 THz to 1 THz range. The cured product of Example 8 has a high transmittance in the frequency range of 1.5 THz or less, and the cured product of Example 11 has a high transmittance at frequencies above 1.5 THz, 3 THz. At frequencies above that, the sample is too thick, resulting in low transmittance and increased noise, slightly reducing reliability, but this tendency can be confirmed up to 7 THz.

[0139] As described above, it was found that the composition containing the cyclobutane polymerizable compound used in the present invention has excellent low dielectric properties in the range of 10 GHz to 3 THz and also has high transmittance for electromagnetic waves in the terahertz range, compared to compositions containing polymerizable compounds using a dicyclohexyl structure as the skeleton or a biphenyl skeleton.

[0140] Not only the composition of the present invention, but also resin materials for electronic devices are often copolymerized with other polymerizable compounds in order to adjust their physical properties or impart special characteristics, or are composited with compounds that do not directly polymerize with the composition of the present invention but have a semi-IPN structure. The dielectric constant at 10 GHz was measured in combination with polyphenylene ether (mPPE) and an active ester curing agent, which are increasingly being used in resin materials for 5G.

[0141] <Compositing of Radical-Reactive Composition> [Example 13] <Preparation of Sample for Measuring Dielectric Properties (Dielectric Constant and Dielectric Loss Tangent)> 0.6 g of compound (S06), a cyclobutane-polymerizable compound, as compound (1), and 0.6 g of a powder of a polyphenylene ether oligomer having methacrylates introduced at both ends as a polymerizable compound (mPPE: manufactured by SABIC, product name: Noryl SA9000 resin) were placed in a 20 mL glass tube, and 2.8 g of toluene was added and dissolved at 80° C. After dissolution, the solution was slowly cooled in an oven, and 0.012 g of a polymerization initiator, manufactured by NOF Corporation, product name: Perbutyl P, was added using a resin spoon so that the concentration was 1 wt % of the resin-forming components, and the mixture was mixed to obtain a solution of a low-dielectric-constant resin-forming composition. This solution was applied to an A4-sized, 50 μm-thick polyimide film (Kapton (registered trademark) manufactured by DuPont-Toray Co., Ltd.) using an applicator to a dry thickness of 40 μm, which was placed on a hot plate set at 80°C to prevent the resin from solidifying, and the film was then pre-dried. If the thickness after pre-drying did not reach the target value, another layer was applied. The sample, from which most of the solvent had evaporated, was cured in a nitrogen atmosphere at 200°C for 60 minutes to obtain a two-layer sheet for evaluating dielectric properties.

[0142] <Evaluation of Dielectric Properties (Relative Permittivity and Dielectric Loss Tangent)> Using a cavity resonator (TE mode 10 GHz, 28 GHz, 40 GHz) manufactured by AET, INC. connected to a vector network analyzer (MS46522B-043 manufactured by Anritsu Corporation), the shift amount and attenuation amount of the resonant frequency of the dielectric property measurement sample were measured, and the relative permittivity (D ｋ ) and dielectric loss tangent (D ｆThe dielectric properties of the polyimide film were determined. Because film thickness significantly affects measurement accuracy, the total thickness of the prepared sample was measured at five points using a Mitutoyo Corporation digimatic micrometer, and the average value was used for calculations. To minimize the effect of moisture content in the sample, the sample was left in a laboratory with the air conditioner set to 23°C (relative humidity remained at approximately 65% ​​RH on the day) the night before, and measurements began the following afternoon. Because the film thickness was large, the sample may have curled due to cure shrinkage; however, measurements were performed by pressing the sample flat to allow insertion into the resonator. While cracks may have developed during this process, if there were no gaps, this had little effect on the resonance method, so measurements were continued as is. Since these measurements represent the results for two layers, the polyimide film and the cured film, a polyimide film with the same heat and humidity history was prepared at the same time as the sample was prepared. The measurements of this polyimide film were used as the dielectric properties of the first layer, and the dielectric properties of the cured film alone, such as the dielectric constant and dielectric loss tangent, were calculated using the company's two-layer film calculation spreadsheet.

[0143] Example 14 A sample was prepared in the same manner as in Example 13, except that the compound (S03) was used instead of the compound (S06), and the dielectric properties were evaluated. The results are shown in Example 14.

[0144] A sample was prepared in the same manner as in Example 13, except that triallyl isocyanurate (TAIC) (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of compound (S06), and the dielectric properties were evaluated. The result is shown as Comparative Example 5.

[0145] <Dielectric properties at 10 GHz of cured products of radical reactive compositions> [Table 8]

[0146] Comparing Examples 13 and 14 with Comparative Example 5 reveals that the cyclobutane polymerizable compound used in the present invention, even when copolymerized with other polymerizable compounds, exhibits superior low dielectric properties compared to the isocyanuric acid compounds commonly used in conventional mPPE. Furthermore, when the relative dielectric constant is important, compound (S03) is used, and when the dielectric loss tangent is important, compound (S06) is used, which provides the desired characteristics. While it is not clear whether this selection applies to all polymerizable compounds, by appropriately selecting the appropriate compound depending on the desired polymerization method, temperature, and properties, electronic materials with superior dielectric properties to those of conventional materials can be formed.

[0147] <Compositing of Epoxy Compound-Containing Thermosetting Compositions> [Example 15] <Preparation and Evaluation of Sample for Measuring Dielectric Properties (Dielectric Constant and Dielectric Loss Tangent)> 0.34 g of compound (S05), a cyclobutane-polymerizable compound, as compound (1) and 1.29 g of an active ester-based curing agent (manufactured by DIC Corporation under the trade name of EPICLON (registered trademark) HPC-8000-65T) as a curing agent were weighed into aluminum cups and mixed with a spatula until no unevenness was visible, obtaining a mixture. HPC-8000-65T contains 65% by weight of toluene, and since raising the temperature to allow curing as is would result in foaming, the mixture was dried for 24 hours in a vacuum oven set to 60°C to evaporate the toluene. The mixture contained in the aluminum cup was placed on a hot plate, along with the aluminum cup, and heated to 120°C. Once the solids had softened to a paste, 0.5 wt% (4.0 mg) of 4-dimethylaminopyridine (DMAP) (Tokyo Chemical Industry Co., Ltd.) was added as a curing accelerator and mixed quickly. This paste solidified upon returning to room temperature, so it was applied to the inside of the frame of the polyimide film used in Example 1 using a medicine spoon before solidification. The polyimide film carrying the solidified mixture was sandwiched between a 0.3 mm thick PTFE sheet and a 2 mm thick aluminum plate on the outside, placed in a small heating press manufactured by Imoto Machinery Co., Ltd., and evacuated until the vacuum gauge reached its limit. After achieving a vacuum, the temperature of the hot plate was raised to 80°C and the mixture was dried for 1 hour. After confirming that foaming had ceased, the temperature was raised to 130°C to soften the resin, which was then crushed at 10 MPa and degassed. After degassing, the pressure was increased to 20 MPa, the temperature was raised to 200°C, and the sample was fully cured for 2 hours while maintaining the pressure and temperature. After natural cooling to 80°C, the sample was removed and an 80 mm square two-layer film (two layers: polyimide film and cured film) was cut out from the inside of the polyimide tape using a utility knife to prepare a sample for measuring dielectric properties. The dielectric properties were evaluated in the same manner as in Example 13. The results are shown in Example 15.

[0148] A sample was prepared in the same manner as in Example 13, except that the compound (S05) was replaced with a bisphenol F epoxy compound (manufactured by Mitsubishi Chemical Corporation, product name jER (registered trademark) 807) shown below as the polymerizable compound, and the dielectric properties were evaluated. The result is shown as Comparative Example 6.

[0149] <Dielectric properties of cured epoxy compound at 10 GHz> [Table 9]

[0150] A comparison of Example 15 and Comparative Example 6 shows that the cyclobutane polymerizable compound used in the present invention has significantly improved dielectric properties compared to the widely used bisphenol F epoxy compounds. Epoxy resins are widely used in insulating materials such as insulating layers, adhesive layers, and sealants for semiconductors, as well as printed wiring boards, and it is clear that epoxy resins can greatly contribute to lowering the dielectric properties of these materials.

[0151] The highly permeable, low dielectric constant resin-forming composition of the present invention is suitable for use as a curable material for electronic devices having a low dielectric constant and a low dielectric loss tangent in the 10 GHz or higher frequency range. Furthermore, since the composition exhibits high transmittance in addition to the above properties, it can be suitably used for protective layers of devices that transmit and receive electromagnetic waves.

Claims

1. A composition for forming a low dielectric constant resin, which contains a cyclobutane ring compound represented by formula (1) having at least one 2,2,4,4-tetramethylcyclobutane ring and polymerizable groups at both ends, and which, when cured without adding an inorganic filler to the composition, produces a cured product with a relative dielectric constant of less than 2.7 at 10 GHz to 3 THz. In formula (1), A １ and A ２ are independently 2,2,4,4-tetramethylcyclobutane-1,3-diyl, 1,4-phenylene or 1,4-cyclohexylene, and in the 1,4-phenylene and 1,4-cyclohexylene rings, 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; A １ and A ２ At least one of the ring structures of Z is 2,2,4,4-tetramethylcyclobutane-1,3-diyl; １ , Z ２ , and Z ３ are independently a single bond or an alkylene having 1 to 20 carbon atoms, and in this alkylene, at least one —CH ２ - may be replaced by -O-, s is an integer of 0 to 6, P １ and P ２ are independently a group selected from the polymerizable groups represented by formulas (PG-1) to (PG-9), In formulas (PG-1) to (PG-5), R ｂ represents hydrogen, halogen, -CF ３ or alkyl having 1 to 5 carbon atoms, q is 0 or 1, ｂ When there are a plurality of, they may be the same or different.

2. In formula (1), s is 0, 1 or 2, and P １ and P ２ are independently a polymerizable group represented by formula (PG-1), (PG-5), (PG-6), (PG-7), or (PG-8).

3. In formula (1), s is 0 and P １ and P ２ are independently a polymerizable group represented by formula (PG-1), (PG-5), (PG-6), (PG-7), or (PG-8).

4. A composition for forming a low dielectric constant resin according to claim 3, wherein the cyclobutane ring compound represented by formula (1) according to claim 1 contains 45% by weight or more of cis-isomers.

5. A composition for forming a low dielectric constant resin according to claim 3, wherein the cyclobutane ring compound represented by formula (1) according to claim 1 contains 60% by weight or more of cis-isomers.

6. The composition for forming a low dielectric constant resin according to any one of claims 1 to 5, comprising at least one selected from the following (A) and (B): (A) a polymer of a cyclobutane ring compound represented by formula (1) according to claim 1; and (B) a polymerizable compound other than the cyclobutane ring compound represented by formula (1) according to claim 1.

7. A composition for forming a low dielectric constant resin according to any one of claims 1 to 6, wherein the composition has a high transmittance for a cured product having a thickness of 500 μm, and the transmittance of the cured product is 50% or more for electromagnetic waves of 0.5 to 1 THz.

8. A low dielectric constant resin-forming composition according to any one of claims 1 to 6, containing an inorganic filler, 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.

9. A low dielectric constant resin-forming composition according to any one of claims 1 to 6 and claim 8, which contains a fibrous reinforcing agent, wherein the fibrous reinforcing agent is at least one selected from the group consisting of carbon fiber, carbon nanotube, silicate whisker, alumina whisker, magnesium oxide whisker, zinc oxide whisker, aluminum nitride whisker, and cellulose nanofiber.

10. A low dielectric constant resin insulating film which is a polymer molded product obtained by curing the low dielectric constant resin forming composition according to any one of claims 1 to 9 with heat or ultraviolet light.

11. A low dielectric constant resin film or a low dielectric constant resin sheet, which is a polymer molded product obtained by curing the low dielectric constant resin composition according to any one of claims 1 to 9 with heat or ultraviolet light.

12. The low dielectric constant resin sheet according to claim 11, wherein the low dielectric constant resin sheet is a polymer molded article having an electromagnetic wave transmittance of 25% or more at 1 THz when the sheet is 1 mm thick.

13. A low dielectric constant resin part which is a polymer molded product obtained by curing the low dielectric constant resin-forming composition according to any one of claims 1 to 9 with heat or ultraviolet light.

14. An electronic device using the polymer molded article according to any one of claims 10 to 13.

15. The cyclobutane ring compound represented by formula (1) according to claim 1, wherein A １ is 2,2,4,4-tetramethylcyclobutane-1,3-diyl, and Z １ and Z ３ are independently alkylene having 1 to 20 carbon atoms; and in this alkylene, at least one —CH ２ - may be replaced by -O-, s is 0, and P １ and P ２ are independently a group selected from polymerizable groups represented by formulae (PG-1), (PG-5), (PG-6), (PG-7) and (PG-8).

16. The cyclobutane ring compound according to claim 15, which is a cyclobutane ring compound selected from the compounds represented by formulas (1-1-1) to (1-1-7). In the formulas (1-1-1) to (1-1-7), n is an integer of 1 to 16.

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